Fix mariadb/mysql macro confusion
[exim.git] / src / src / smtp_in.c
CommitLineData
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1/*************************************************
2* Exim - an Internet mail transport agent *
3*************************************************/
4
d4e5e70b 5/* Copyright (c) University of Cambridge 1995 - 2017 */
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6/* See the file NOTICE for conditions of use and distribution. */
7
8/* Functions for handling an incoming SMTP call. */
9
10
11#include "exim.h"
2ef7ed08 12#include <assert.h>
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13
14
15/* Initialize for TCP wrappers if so configured. It appears that the macro
16HAVE_IPV6 is used in some versions of the tcpd.h header, so we unset it before
17including that header, and restore its value afterwards. */
18
19#ifdef USE_TCP_WRAPPERS
20
21 #if HAVE_IPV6
22 #define EXIM_HAVE_IPV6
23 #endif
24 #undef HAVE_IPV6
25 #include <tcpd.h>
26 #undef HAVE_IPV6
27 #ifdef EXIM_HAVE_IPV6
28 #define HAVE_IPV6 TRUE
29 #endif
30
31int allow_severity = LOG_INFO;
32int deny_severity = LOG_NOTICE;
5dc43717 33uschar *tcp_wrappers_name;
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34#endif
35
36
8d67ada3
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37/* Size of buffer for reading SMTP commands. We used to use 512, as defined
38by RFC 821. However, RFC 1869 specifies that this must be increased for SMTP
39commands that accept arguments, and this in particular applies to AUTH, where
94431adb 40the data can be quite long. More recently this value was 2048 in Exim;
e2ca7082 41however, RFC 4954 (circa 2007) recommends 12288 bytes to handle AUTH. Clients
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42such as Thunderbird will send an AUTH with an initial-response for GSSAPI.
43The maximum size of a Kerberos ticket under Windows 2003 is 12000 bytes, and
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44we need room to handle large base64-encoded AUTHs for GSSAPI.
45*/
46
bd8fbe36 47#define SMTP_CMD_BUFFER_SIZE 16384
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48
49/* Size of buffer for reading SMTP incoming packets */
50
bd8fbe36 51#define IN_BUFFER_SIZE 8192
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52
53/* Structure for SMTP command list */
54
55typedef struct {
1ba28e2b 56 const char *name;
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57 int len;
58 short int cmd;
59 short int has_arg;
60 short int is_mail_cmd;
61} smtp_cmd_list;
62
63/* Codes for identifying commands. We order them so that those that come first
64are those for which synchronization is always required. Checking this can help
65block some spam. */
66
67enum {
68 /* These commands are required to be synchronized, i.e. to be the last in a
69 block of commands when pipelining. */
70
71 HELO_CMD, EHLO_CMD, DATA_CMD, /* These are listed in the pipelining */
72 VRFY_CMD, EXPN_CMD, NOOP_CMD, /* RFC as requiring synchronization */
73 ETRN_CMD, /* This by analogy with TURN from the RFC */
74 STARTTLS_CMD, /* Required by the STARTTLS RFC */
b3ef41c9 75 TLS_AUTH_CMD, /* auto-command at start of SSL */
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76
77 /* This is a dummy to identify the non-sync commands when pipelining */
78
79 NON_SYNC_CMD_PIPELINING,
80
81 /* These commands need not be synchronized when pipelining */
82
83 MAIL_CMD, RCPT_CMD, RSET_CMD,
84
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85 /* This is a dummy to identify the non-sync commands when not pipelining */
86
87 NON_SYNC_CMD_NON_PIPELINING,
88
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89 /* RFC3030 section 2: "After all MAIL and RCPT responses are collected and
90 processed the message is sent using a series of BDAT commands"
91 implies that BDAT should be synchronized. However, we see Google, at least,
92 sending MAIL,RCPT,BDAT-LAST in a single packet, clearly not waiting for
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93 processing of the RCPT response(s). We shall do the same, and not require
94 synch for BDAT. Worse, as the chunk may (very likely will) follow the
95 command-header in the same packet we cannot do the usual "is there any
4c04137d 96 follow-on data after the command line" even for non-pipeline mode.
f4630439 97 So we'll need an explicit check after reading the expected chunk amount
4c04137d 98 when non-pipe, before sending the ACK. */
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99
100 BDAT_CMD,
101
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102 /* I have been unable to find a statement about the use of pipelining
103 with AUTH, so to be on the safe side it is here, though I kind of feel
104 it should be up there with the synchronized commands. */
105
106 AUTH_CMD,
107
108 /* I'm not sure about these, but I don't think they matter. */
109
110 QUIT_CMD, HELP_CMD,
111
cee5f132 112#ifdef SUPPORT_PROXY
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113 PROXY_FAIL_IGNORE_CMD,
114#endif
115
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116 /* These are specials that don't correspond to actual commands */
117
118 EOF_CMD, OTHER_CMD, BADARG_CMD, BADCHAR_CMD, BADSYN_CMD,
119 TOO_MANY_NONMAIL_CMD };
120
121
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122/* This is a convenience macro for adding the identity of an SMTP command
123to the circular buffer that holds a list of the last n received. */
124
125#define HAD(n) \
126 smtp_connection_had[smtp_ch_index++] = n; \
127 if (smtp_ch_index >= SMTP_HBUFF_SIZE) smtp_ch_index = 0
128
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129
130/*************************************************
131* Local static variables *
132*************************************************/
133
134static auth_instance *authenticated_by;
135static BOOL auth_advertised;
136#ifdef SUPPORT_TLS
137static BOOL tls_advertised;
138#endif
6c1c3d1d 139static BOOL dsn_advertised;
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140static BOOL esmtp;
141static BOOL helo_required = FALSE;
142static BOOL helo_verify = FALSE;
143static BOOL helo_seen;
144static BOOL helo_accept_junk;
145static BOOL count_nonmail;
146static BOOL pipelining_advertised;
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147static BOOL rcpt_smtp_response_same;
148static BOOL rcpt_in_progress;
059ec3d9 149static int nonmail_command_count;
8f128379 150static BOOL smtp_exit_function_called = 0;
8c5d388a 151#ifdef SUPPORT_I18N
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152static BOOL smtputf8_advertised;
153#endif
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154static int synprot_error_count;
155static int unknown_command_count;
156static int sync_cmd_limit;
157static int smtp_write_error = 0;
158
2679d413 159static uschar *rcpt_smtp_response;
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160static uschar *smtp_data_buffer;
161static uschar *smtp_cmd_data;
162
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163/* We need to know the position of RSET, HELO, EHLO, AUTH, and STARTTLS. Their
164final fields of all except AUTH are forced TRUE at the start of a new message
165setup, to allow one of each between messages that is not counted as a nonmail
166command. (In fact, only one of HELO/EHLO is not counted.) Also, we have to
167allow a new EHLO after starting up TLS.
168
169AUTH is "falsely" labelled as a mail command initially, so that it doesn't get
170counted. However, the flag is changed when AUTH is received, so that multiple
171failing AUTHs will eventually hit the limit. After a successful AUTH, another
172AUTH is already forbidden. After a TLS session is started, AUTH's flag is again
173forced TRUE, to allow for the re-authentication that can happen at that point.
174
175QUIT is also "falsely" labelled as a mail command so that it doesn't up the
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176count of non-mail commands and possibly provoke an error.
177
178tls_auth is a pseudo-command, never expected in input. It is activated
179on TLS startup and looks for a tls authenticator. */
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180
181static smtp_cmd_list cmd_list[] = {
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182 /* name len cmd has_arg is_mail_cmd */
183
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184 { "rset", sizeof("rset")-1, RSET_CMD, FALSE, FALSE }, /* First */
185 { "helo", sizeof("helo")-1, HELO_CMD, TRUE, FALSE },
186 { "ehlo", sizeof("ehlo")-1, EHLO_CMD, TRUE, FALSE },
187 { "auth", sizeof("auth")-1, AUTH_CMD, TRUE, TRUE },
188 #ifdef SUPPORT_TLS
189 { "starttls", sizeof("starttls")-1, STARTTLS_CMD, FALSE, FALSE },
b3ef41c9 190 { "tls_auth", 0, TLS_AUTH_CMD, FALSE, TRUE },
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191 #endif
192
193/* If you change anything above here, also fix the definitions below. */
194
195 { "mail from:", sizeof("mail from:")-1, MAIL_CMD, TRUE, TRUE },
196 { "rcpt to:", sizeof("rcpt to:")-1, RCPT_CMD, TRUE, TRUE },
197 { "data", sizeof("data")-1, DATA_CMD, FALSE, TRUE },
18481de3 198 { "bdat", sizeof("bdat")-1, BDAT_CMD, TRUE, TRUE },
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199 { "quit", sizeof("quit")-1, QUIT_CMD, FALSE, TRUE },
200 { "noop", sizeof("noop")-1, NOOP_CMD, TRUE, FALSE },
201 { "etrn", sizeof("etrn")-1, ETRN_CMD, TRUE, FALSE },
202 { "vrfy", sizeof("vrfy")-1, VRFY_CMD, TRUE, FALSE },
203 { "expn", sizeof("expn")-1, EXPN_CMD, TRUE, FALSE },
204 { "help", sizeof("help")-1, HELP_CMD, TRUE, FALSE }
205};
206
207static smtp_cmd_list *cmd_list_end =
208 cmd_list + sizeof(cmd_list)/sizeof(smtp_cmd_list);
209
210#define CMD_LIST_RSET 0
211#define CMD_LIST_HELO 1
212#define CMD_LIST_EHLO 2
213#define CMD_LIST_AUTH 3
214#define CMD_LIST_STARTTLS 4
b3ef41c9 215#define CMD_LIST_TLS_AUTH 5
059ec3d9 216
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217/* This list of names is used for performing the smtp_no_mail logging action.
218It must be kept in step with the SCH_xxx enumerations. */
219
220static uschar *smtp_names[] =
221 {
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222 US"NONE", US"AUTH", US"DATA", US"BDAT", US"EHLO", US"ETRN", US"EXPN",
223 US"HELO", US"HELP", US"MAIL", US"NOOP", US"QUIT", US"RCPT", US"RSET",
224 US"STARTTLS", US"VRFY" };
b4ed4da0 225
e524074d 226static uschar *protocols_local[] = {
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227 US"local-smtp", /* HELO */
228 US"local-smtps", /* The rare case EHLO->STARTTLS->HELO */
229 US"local-esmtp", /* EHLO */
230 US"local-esmtps", /* EHLO->STARTTLS->EHLO */
231 US"local-esmtpa", /* EHLO->AUTH */
232 US"local-esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */
059ec3d9 233 };
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234static uschar *protocols[] = {
235 US"smtp", /* HELO */
236 US"smtps", /* The rare case EHLO->STARTTLS->HELO */
237 US"esmtp", /* EHLO */
238 US"esmtps", /* EHLO->STARTTLS->EHLO */
239 US"esmtpa", /* EHLO->AUTH */
240 US"esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */
241 };
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242
243#define pnormal 0
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244#define pextend 2
245#define pcrpted 1 /* added to pextend or pnormal */
246#define pauthed 2 /* added to pextend */
059ec3d9 247
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248/* Sanity check and validate optional args to MAIL FROM: envelope */
249enum {
2ef7ed08 250 ENV_MAIL_OPT_NULL,
d27f98fe 251 ENV_MAIL_OPT_SIZE, ENV_MAIL_OPT_BODY, ENV_MAIL_OPT_AUTH,
8ccd00b1 252#ifndef DISABLE_PRDR
fd98a5c6 253 ENV_MAIL_OPT_PRDR,
6c1c3d1d 254#endif
6c1c3d1d 255 ENV_MAIL_OPT_RET, ENV_MAIL_OPT_ENVID,
8c5d388a 256#ifdef SUPPORT_I18N
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257 ENV_MAIL_OPT_UTF8,
258#endif
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259 };
260typedef struct {
261 uschar * name; /* option requested during MAIL cmd */
262 int value; /* enum type */
263 BOOL need_value; /* TRUE requires value (name=value pair format)
264 FALSE is a singleton */
265 } env_mail_type_t;
266static env_mail_type_t env_mail_type_list[] = {
267 { US"SIZE", ENV_MAIL_OPT_SIZE, TRUE },
268 { US"BODY", ENV_MAIL_OPT_BODY, TRUE },
269 { US"AUTH", ENV_MAIL_OPT_AUTH, TRUE },
8ccd00b1 270#ifndef DISABLE_PRDR
fd98a5c6 271 { US"PRDR", ENV_MAIL_OPT_PRDR, FALSE },
6c1c3d1d 272#endif
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273 { US"RET", ENV_MAIL_OPT_RET, TRUE },
274 { US"ENVID", ENV_MAIL_OPT_ENVID, TRUE },
8c5d388a 275#ifdef SUPPORT_I18N
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276 { US"SMTPUTF8",ENV_MAIL_OPT_UTF8, FALSE }, /* rfc6531 */
277#endif
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278 /* keep this the last entry */
279 { US"NULL", ENV_MAIL_OPT_NULL, FALSE },
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280 };
281
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282/* When reading SMTP from a remote host, we have to use our own versions of the
283C input-reading functions, in order to be able to flush the SMTP output only
284when about to read more data from the socket. This is the only way to get
285optimal performance when the client is using pipelining. Flushing for every
286command causes a separate packet and reply packet each time; saving all the
287responses up (when pipelining) combines them into one packet and one response.
288
289For simplicity, these functions are used for *all* SMTP input, not only when
290receiving over a socket. However, after setting up a secure socket (SSL), input
291is read via the OpenSSL library, and another set of functions is used instead
292(see tls.c).
293
294These functions are set in the receive_getc etc. variables and called with the
295same interface as the C functions. However, since there can only ever be
296one incoming SMTP call, we just use a single buffer and flags. There is no need
297to implement a complicated private FILE-like structure.*/
298
299static uschar *smtp_inbuffer;
300static uschar *smtp_inptr;
301static uschar *smtp_inend;
302static int smtp_had_eof;
303static int smtp_had_error;
304
305
7e3ce68e 306/* forward declarations */
bd8fbe36 307static int smtp_read_command(BOOL check_sync, unsigned buffer_lim);
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308static int synprot_error(int type, int code, uschar *data, uschar *errmess);
309static void smtp_quit_handler(uschar **, uschar **);
310static void smtp_rset_handler(void);
311
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312/*************************************************
313* Recheck synchronization *
314*************************************************/
315
316/* Synchronization checks can never be perfect because a packet may be on its
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317way but not arrived when the check is done. Normally, the checks happen when
318commands are read: Exim ensures that there is no more input in the input buffer.
319In normal cases, the response to the command will be fast, and there is no
320further check.
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321
322However, for some commands an ACL is run, and that can include delays. In those
323cases, it is useful to do another check on the input just before sending the
324response. This also applies at the start of a connection. This function does
325that check by means of the select() function, as long as the facility is not
326disabled or inappropriate. A failure of select() is ignored.
327
328When there is unwanted input, we read it so that it appears in the log of the
329error.
330
331Arguments: none
332Returns: TRUE if all is well; FALSE if there is input pending
333*/
334
335static BOOL
925ac8e4 336wouldblock_reading(void)
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337{
338int fd, rc;
339fd_set fds;
340struct timeval tzero;
341
9067f574 342#ifdef SUPPORT_TLS
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343if (tls_in.active >= 0)
344 return !tls_could_read();
9067f574 345#endif
f4630439 346
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347if (smtp_inptr < smtp_inend)
348 return FALSE;
349
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350fd = fileno(smtp_in);
351FD_ZERO(&fds);
352FD_SET(fd, &fds);
353tzero.tv_sec = 0;
354tzero.tv_usec = 0;
355rc = select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &tzero);
356
357if (rc <= 0) return TRUE; /* Not ready to read */
bd8fbe36 358rc = smtp_getc(GETC_BUFFER_UNLIMITED);
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359if (rc < 0) return TRUE; /* End of file or error */
360
361smtp_ungetc(rc);
362rc = smtp_inend - smtp_inptr;
363if (rc > 150) rc = 150;
364smtp_inptr[rc] = 0;
365return FALSE;
366}
367
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368static BOOL
369check_sync(void)
370{
371if (!smtp_enforce_sync || sender_host_address == NULL || sender_host_notsocket)
372 return TRUE;
373
374return wouldblock_reading();
375}
376
377
378/* If there's input waiting (and we're doing pipelineing) then we can pipeline
379a reponse with the one following. */
380
381static BOOL
382pipeline_response(void)
383{
384if ( !smtp_enforce_sync || !sender_host_address
385 || sender_host_notsocket || !pipelining_advertised)
386 return FALSE;
387
388return !wouldblock_reading();
389}
390
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391
392
393/*************************************************
394* Log incomplete transactions *
395*************************************************/
396
397/* This function is called after a transaction has been aborted by RSET, QUIT,
398connection drops or other errors. It logs the envelope information received
399so far in order to preserve address verification attempts.
400
401Argument: string to indicate what aborted the transaction
402Returns: nothing
403*/
404
405static void
406incomplete_transaction_log(uschar *what)
407{
408if (sender_address == NULL || /* No transaction in progress */
409 !LOGGING(smtp_incomplete_transaction))
410 return;
411
412/* Build list of recipients for logging */
413
414if (recipients_count > 0)
415 {
416 int i;
417 raw_recipients = store_get(recipients_count * sizeof(uschar *));
418 for (i = 0; i < recipients_count; i++)
419 raw_recipients[i] = recipients_list[i].address;
420 raw_recipients_count = recipients_count;
421 }
422
423log_write(L_smtp_incomplete_transaction, LOG_MAIN|LOG_SENDER|LOG_RECIPIENTS,
424 "%s incomplete transaction (%s)", host_and_ident(TRUE), what);
425}
426
427
428
429
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430/* Refill the buffer, and notify DKIM verification code.
431Return false for error or EOF.
432*/
433
434static BOOL
435smtp_refill(unsigned lim)
436{
437int rc, save_errno;
438if (!smtp_out) return FALSE;
439fflush(smtp_out);
440if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
441
442/* Limit amount read, so non-message data is not fed to DKIM */
443
444rc = read(fileno(smtp_in), smtp_inbuffer, MIN(IN_BUFFER_SIZE, lim));
445save_errno = errno;
446alarm(0);
447if (rc <= 0)
448 {
449 /* Must put the error text in fixed store, because this might be during
450 header reading, where it releases unused store above the header. */
451 if (rc < 0)
452 {
453 smtp_had_error = save_errno;
454 smtp_read_error = string_copy_malloc(
455 string_sprintf(" (error: %s)", strerror(save_errno)));
456 }
457 else smtp_had_eof = 1;
458 return FALSE;
459 }
460#ifndef DISABLE_DKIM
461dkim_exim_verify_feed(smtp_inbuffer, rc);
462#endif
463smtp_inend = smtp_inbuffer + rc;
464smtp_inptr = smtp_inbuffer;
465return TRUE;
466}
467
059ec3d9
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468/*************************************************
469* SMTP version of getc() *
470*************************************************/
471
472/* This gets the next byte from the SMTP input buffer. If the buffer is empty,
473it flushes the output, and refills the buffer, with a timeout. The signal
474handler is set appropriately by the calling function. This function is not used
4c04137d 475after a connection has negotiated itself into an TLS/SSL state.
059ec3d9 476
bd8fbe36 477Arguments: lim Maximum amount to read/buffer
059ec3d9
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478Returns: the next character or EOF
479*/
480
481int
bd8fbe36 482smtp_getc(unsigned lim)
059ec3d9
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483{
484if (smtp_inptr >= smtp_inend)
0d81dabc 485 if (!smtp_refill(lim))
059ec3d9 486 return EOF;
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487return *smtp_inptr++;
488}
489
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490uschar *
491smtp_getbuf(unsigned * len)
492{
493unsigned size;
494uschar * buf;
495
496if (smtp_inptr >= smtp_inend)
497 if (!smtp_refill(*len))
498 { *len = 0; return NULL; }
499
500if ((size = smtp_inend - smtp_inptr) > *len) size = *len;
501buf = smtp_inptr;
502smtp_inptr += size;
503*len = size;
504return buf;
505}
506
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507void
508smtp_get_cache(void)
509{
9960d1e5 510#ifndef DISABLE_DKIM
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511int n = smtp_inend - smtp_inptr;
512if (n > 0)
513 dkim_exim_verify_feed(smtp_inptr, n);
584e96c6 514#endif
9960d1e5 515}
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516
517
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518/* Get a byte from the smtp input, in CHUNKING mode. Handle ack of the
519previous BDAT chunk and getting new ones when we run out. Uses the
520underlying smtp_getc or tls_getc both for that and for getting the
521(buffered) data byte. EOD signals (an expected) no further data.
522ERR signals a protocol error, and EOF a closed input stream.
523
524Called from read_bdat_smtp() in receive.c for the message body, but also
525by the headers read loop in receive_msg(); manipulates chunking_state
526to handle the BDAT command/response.
527Placed here due to the correlation with the above smtp_getc(), which it wraps,
528and also by the need to do smtp command/response handling.
529
bd8fbe36 530Arguments: lim (ignored)
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531Returns: the next character or ERR, EOD or EOF
532*/
533
534int
bd8fbe36 535bdat_getc(unsigned lim)
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536{
537uschar * user_msg = NULL;
538uschar * log_msg;
539
540for(;;)
541 {
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542#ifndef DISABLE_DKIM
543 BOOL dkim_save;
544#endif
545
bd8fbe36
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546 if (chunking_data_left > 0)
547 return lwr_receive_getc(chunking_data_left--);
7e3ce68e
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548
549 receive_getc = lwr_receive_getc;
0d81dabc 550 receive_getbuf = lwr_receive_getbuf;
7e3ce68e 551 receive_ungetc = lwr_receive_ungetc;
bd8fbe36 552#ifndef DISABLE_DKIM
79de4f37 553 dkim_save = dkim_collect_input;
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JH
554 dkim_collect_input = FALSE;
555#endif
7e3ce68e 556
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557 /* Unless PIPELINING was offered, there should be no next command
558 until after we ack that chunk */
559
560 if (!pipelining_advertised && !check_sync())
561 {
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562 unsigned n = smtp_inend - smtp_inptr;
563 if (n > 32) n = 32;
564
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565 incomplete_transaction_log(US"sync failure");
566 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol synchronization error "
567 "(next input sent too soon: pipelining was not advertised): "
9e0ed81f 568 "rejected \"%s\" %s next input=\"%s\"%s",
f4630439 569 smtp_cmd_buffer, host_and_ident(TRUE),
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570 string_printing(string_copyn(smtp_inptr, n)),
571 smtp_inend - smtp_inptr > n ? "..." : "");
572 (void) synprot_error(L_smtp_protocol_error, 554, NULL,
573 US"SMTP synchronization error");
f4630439
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574 goto repeat_until_rset;
575 }
576
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577 /* If not the last, ack the received chunk. The last response is delayed
578 until after the data ACL decides on it */
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579
580 if (chunking_state == CHUNKING_LAST)
584e96c6
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581 {
582#ifndef DISABLE_DKIM
e983e85a 583 dkim_exim_verify_feed(NULL, 0); /* notify EOD */
584e96c6 584#endif
7e3ce68e 585 return EOD;
584e96c6 586 }
7e3ce68e 587
925ac8e4 588 smtp_printf("250 %u byte chunk received\r\n", FALSE, chunking_datasize);
bd8fbe36
JH
589 chunking_state = CHUNKING_OFFERED;
590 DEBUG(D_receive) debug_printf("chunking state %d\n", (int)chunking_state);
7e3ce68e
JH
591
592 /* Expect another BDAT cmd from input. RFC 3030 says nothing about
593 QUIT, RSET or NOOP but handling them seems obvious */
594
595next_cmd:
bd8fbe36 596 switch(smtp_read_command(TRUE, 1))
7e3ce68e
JH
597 {
598 default:
599 (void) synprot_error(L_smtp_protocol_error, 503, NULL,
600 US"only BDAT permissible after non-LAST BDAT");
601
602 repeat_until_rset:
bd8fbe36 603 switch(smtp_read_command(TRUE, 1))
7e3ce68e
JH
604 {
605 case QUIT_CMD: smtp_quit_handler(&user_msg, &log_msg); /*FALLTHROUGH */
606 case EOF_CMD: return EOF;
607 case RSET_CMD: smtp_rset_handler(); return ERR;
608 default: if (synprot_error(L_smtp_protocol_error, 503, NULL,
609 US"only RSET accepted now") > 0)
610 return EOF;
611 goto repeat_until_rset;
612 }
613
614 case QUIT_CMD:
615 smtp_quit_handler(&user_msg, &log_msg);
616 /*FALLTHROUGH*/
617 case EOF_CMD:
618 return EOF;
619
620 case RSET_CMD:
621 smtp_rset_handler();
622 return ERR;
623
624 case NOOP_CMD:
625 HAD(SCH_NOOP);
925ac8e4 626 smtp_printf("250 OK\r\n", FALSE);
7e3ce68e
JH
627 goto next_cmd;
628
629 case BDAT_CMD:
630 {
631 int n;
632
633 if (sscanf(CS smtp_cmd_data, "%u %n", &chunking_datasize, &n) < 1)
634 {
635 (void) synprot_error(L_smtp_protocol_error, 501, NULL,
636 US"missing size for BDAT command");
637 return ERR;
638 }
639 chunking_state = strcmpic(smtp_cmd_data+n, US"LAST") == 0
640 ? CHUNKING_LAST : CHUNKING_ACTIVE;
641 chunking_data_left = chunking_datasize;
bd8fbe36
JH
642 DEBUG(D_receive) debug_printf("chunking state %d, %d bytes\n",
643 (int)chunking_state, chunking_data_left);
7e3ce68e
JH
644
645 if (chunking_datasize == 0)
646 if (chunking_state == CHUNKING_LAST)
647 return EOD;
648 else
649 {
650 (void) synprot_error(L_smtp_protocol_error, 504, NULL,
651 US"zero size for BDAT command");
652 goto repeat_until_rset;
653 }
654
655 receive_getc = bdat_getc;
0d81dabc 656 receive_getbuf = bdat_getbuf;
7e3ce68e 657 receive_ungetc = bdat_ungetc;
bd8fbe36 658#ifndef DISABLE_DKIM
79de4f37 659 dkim_collect_input = dkim_save;
bd8fbe36 660#endif
7e3ce68e
JH
661 break; /* to top of main loop */
662 }
663 }
664 }
665}
666
0d81dabc
JH
667uschar *
668bdat_getbuf(unsigned * len)
669{
670uschar * buf;
671
672if (chunking_data_left <= 0)
673 { *len = 0; return NULL; }
674
675if (*len > chunking_data_left) *len = chunking_data_left;
676buf = lwr_receive_getbuf(len); /* Either smtp_getbuf or tls_getbuf */
677chunking_data_left -= *len;
678return buf;
679}
680
1ebe15c3 681void
45bd315d
JH
682bdat_flush_data(void)
683{
0d81dabc
JH
684unsigned n = chunking_data_left;
685(void) bdat_getbuf(&n);
45bd315d
JH
686
687receive_getc = lwr_receive_getc;
0d81dabc 688receive_getbuf = lwr_receive_getbuf;
45bd315d
JH
689receive_ungetc = lwr_receive_ungetc;
690
691if (chunking_state != CHUNKING_LAST)
bd8fbe36 692 {
45bd315d 693 chunking_state = CHUNKING_OFFERED;
bd8fbe36
JH
694 DEBUG(D_receive) debug_printf("chunking state %d\n", (int)chunking_state);
695 }
45bd315d
JH
696}
697
7e3ce68e
JH
698
699
700
059ec3d9
PH
701/*************************************************
702* SMTP version of ungetc() *
703*************************************************/
704
705/* Puts a character back in the input buffer. Only ever
706called once.
707
708Arguments:
709 ch the character
710
711Returns: the character
712*/
713
714int
715smtp_ungetc(int ch)
716{
7e3ce68e 717*--smtp_inptr = ch;
059ec3d9
PH
718return ch;
719}
720
721
7e3ce68e
JH
722int
723bdat_ungetc(int ch)
724{
725chunking_data_left++;
726return lwr_receive_ungetc(ch);
727}
728
059ec3d9
PH
729
730
731/*************************************************
732* SMTP version of feof() *
733*************************************************/
734
735/* Tests for a previous EOF
736
737Arguments: none
738Returns: non-zero if the eof flag is set
739*/
740
741int
742smtp_feof(void)
743{
744return smtp_had_eof;
745}
746
747
748
749
750/*************************************************
751* SMTP version of ferror() *
752*************************************************/
753
754/* Tests for a previous read error, and returns with errno
755restored to what it was when the error was detected.
756
757Arguments: none
758Returns: non-zero if the error flag is set
759*/
760
761int
762smtp_ferror(void)
763{
764errno = smtp_had_error;
765return smtp_had_error;
766}
767
768
769
58eb016e
PH
770/*************************************************
771* Test for characters in the SMTP buffer *
772*************************************************/
773
774/* Used at the end of a message
775
776Arguments: none
777Returns: TRUE/FALSE
778*/
779
780BOOL
781smtp_buffered(void)
782{
783return smtp_inptr < smtp_inend;
784}
785
786
059ec3d9
PH
787
788/*************************************************
789* Write formatted string to SMTP channel *
790*************************************************/
791
792/* This is a separate function so that we don't have to repeat everything for
793TLS support or debugging. It is global so that the daemon and the
794authentication functions can use it. It does not return any error indication,
795because major problems such as dropped connections won't show up till an output
796flush for non-TLS connections. The smtp_fflush() function is available for
797checking that: for convenience, TLS output errors are remembered here so that
798they are also picked up later by smtp_fflush().
799
800Arguments:
801 format format string
925ac8e4 802 more further data expected
059ec3d9
PH
803 ... optional arguments
804
805Returns: nothing
806*/
807
808void
925ac8e4 809smtp_printf(const char *format, BOOL more, ...)
059ec3d9
PH
810{
811va_list ap;
812
925ac8e4
JH
813va_start(ap, more);
814smtp_vprintf(format, more, ap);
ce552449
NM
815va_end(ap);
816}
817
818/* This is split off so that verify.c:respond_printf() can, in effect, call
819smtp_printf(), bearing in mind that in C a vararg function can't directly
fb08281f 820call another vararg function, only a function which accepts a va_list. */
ce552449
NM
821
822void
925ac8e4 823smtp_vprintf(const char *format, BOOL more, va_list ap)
ce552449 824{
fb08281f
DW
825BOOL yield;
826
827yield = string_vformat(big_buffer, big_buffer_size, format, ap);
ce552449 828
059ec3d9
PH
829DEBUG(D_receive)
830 {
fb08281f
DW
831 void *reset_point = store_get(0);
832 uschar *msg_copy, *cr, *end;
833 msg_copy = string_copy(big_buffer);
834 end = msg_copy + Ustrlen(msg_copy);
835 while ((cr = Ustrchr(msg_copy, '\r')) != NULL) /* lose CRs */
836 memmove(cr, cr + 1, (end--) - cr);
837 debug_printf("SMTP>> %s", msg_copy);
838 store_reset(reset_point);
059ec3d9
PH
839 }
840
fb08281f 841if (!yield)
2679d413
PH
842 {
843 log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_printf()");
844 smtp_closedown(US"Unexpected error");
845 exim_exit(EXIT_FAILURE);
846 }
2679d413
PH
847
848/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
849have had the same. Note: this code is also present in smtp_respond(). It would
850be tidier to have it only in one place, but when it was added, it was easier to
851do it that way, so as not to have to mess with the code for the RCPT command,
852which sometimes uses smtp_printf() and sometimes smtp_respond(). */
853
854if (rcpt_in_progress)
855 {
856 if (rcpt_smtp_response == NULL)
857 rcpt_smtp_response = string_copy(big_buffer);
858 else if (rcpt_smtp_response_same &&
859 Ustrcmp(rcpt_smtp_response, big_buffer) != 0)
860 rcpt_smtp_response_same = FALSE;
861 rcpt_in_progress = FALSE;
862 }
059ec3d9 863
2679d413 864/* Now write the string */
059ec3d9
PH
865
866#ifdef SUPPORT_TLS
817d9f57 867if (tls_in.active >= 0)
059ec3d9 868 {
925ac8e4 869 if (tls_write(TRUE, big_buffer, Ustrlen(big_buffer), more) < 0)
817d9f57 870 smtp_write_error = -1;
059ec3d9
PH
871 }
872else
873#endif
874
2679d413 875if (fprintf(smtp_out, "%s", big_buffer) < 0) smtp_write_error = -1;
059ec3d9
PH
876}
877
878
879
880/*************************************************
881* Flush SMTP out and check for error *
882*************************************************/
883
884/* This function isn't currently used within Exim (it detects errors when it
885tries to read the next SMTP input), but is available for use in local_scan().
886For non-TLS connections, it flushes the output and checks for errors. For
887TLS-connections, it checks for a previously-detected TLS write error.
888
889Arguments: none
890Returns: 0 for no error; -1 after an error
891*/
892
893int
894smtp_fflush(void)
895{
817d9f57 896if (tls_in.active < 0 && fflush(smtp_out) != 0) smtp_write_error = -1;
059ec3d9
PH
897return smtp_write_error;
898}
899
900
901
902/*************************************************
903* SMTP command read timeout *
904*************************************************/
905
906/* Signal handler for timing out incoming SMTP commands. This attempts to
907finish off tidily.
908
909Argument: signal number (SIGALRM)
910Returns: nothing
911*/
912
913static void
914command_timeout_handler(int sig)
915{
916sig = sig; /* Keep picky compilers happy */
917log_write(L_lost_incoming_connection,
918 LOG_MAIN, "SMTP command timeout on%s connection from %s",
817d9f57 919 (tls_in.active >= 0)? " TLS" : "",
059ec3d9
PH
920 host_and_ident(FALSE));
921if (smtp_batched_input)
922 moan_smtp_batch(NULL, "421 SMTP command timeout"); /* Does not return */
8f128379
PH
923smtp_notquit_exit(US"command-timeout", US"421",
924 US"%s: SMTP command timeout - closing connection", smtp_active_hostname);
059ec3d9
PH
925exim_exit(EXIT_FAILURE);
926}
927
928
929
930/*************************************************
931* SIGTERM received *
932*************************************************/
933
934/* Signal handler for handling SIGTERM. Again, try to finish tidily.
935
936Argument: signal number (SIGTERM)
937Returns: nothing
938*/
939
940static void
941command_sigterm_handler(int sig)
942{
943sig = sig; /* Keep picky compilers happy */
944log_write(0, LOG_MAIN, "%s closed after SIGTERM", smtp_get_connection_info());
945if (smtp_batched_input)
946 moan_smtp_batch(NULL, "421 SIGTERM received"); /* Does not return */
8f128379
PH
947smtp_notquit_exit(US"signal-exit", US"421",
948 US"%s: Service not available - closing connection", smtp_active_hostname);
059ec3d9
PH
949exim_exit(EXIT_FAILURE);
950}
951
952
953
a14e5636 954
cee5f132 955#ifdef SUPPORT_PROXY
a3bddaa8
TL
956/*************************************************
957* Restore socket timeout to previous value *
958*************************************************/
959/* If the previous value was successfully retrieved, restore
960it before returning control to the non-proxy routines
961
962Arguments: fd - File descriptor for input
963 get_ok - Successfully retrieved previous values
964 tvtmp - Time struct with previous values
965 vslen - Length of time struct
966Returns: none
967*/
968static void
f267271d 969restore_socket_timeout(int fd, int get_ok, struct timeval * tvtmp, socklen_t vslen)
a3bddaa8
TL
970{
971if (get_ok == 0)
f267271d 972 (void) setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS tvtmp, vslen);
a3bddaa8
TL
973}
974
a3c86431
TL
975/*************************************************
976* Check if host is required proxy host *
977*************************************************/
978/* The function determines if inbound host will be a regular smtp host
1811cb4c
JH
979or if it is configured that it must use Proxy Protocol. A local
980connection cannot.
a3c86431
TL
981
982Arguments: none
983Returns: bool
984*/
985
986static BOOL
987check_proxy_protocol_host()
988{
989int rc;
a3c86431 990
1811cb4c
JH
991if ( sender_host_address
992 && (rc = verify_check_this_host(CUSS &hosts_proxy, NULL, NULL,
993 sender_host_address, NULL)) == OK)
a3c86431
TL
994 {
995 DEBUG(D_receive)
996 debug_printf("Detected proxy protocol configured host\n");
997 proxy_session = TRUE;
998 }
999return proxy_session;
1000}
1001
1002
3f251b3c
PP
1003/*************************************************
1004* Read data until newline or end of buffer *
1005*************************************************/
1006/* While SMTP is server-speaks-first, TLS is client-speaks-first, so we can't
1007read an entire buffer and assume there will be nothing past a proxy protocol
1008header. Our approach normally is to use stdio, but again that relies upon
1009"STARTTLS\r\n" and a server response before the client starts TLS handshake, or
1010reading _nothing_ before client TLS handshake. So we don't want to use the
1011usual buffering reads which may read enough to block TLS starting.
1012
1013So unfortunately we're down to "read one byte at a time, with a syscall each,
1014and expect a little overhead", for all proxy-opened connections which are v1,
1015just to handle the TLS-on-connect case. Since SSL functions wrap the
1016underlying fd, we can't assume that we can feed them any already-read content.
1017
1018We need to know where to read to, the max capacity, and we'll read until we
1019get a CR and one more character. Let the caller scream if it's CR+!LF.
1020
1021Return the amount read.
1022*/
1023
1024static int
da88acae 1025swallow_until_crlf(int fd, uschar *base, int already, int capacity)
3f251b3c 1026{
2c0f3ea1
JH
1027uschar *to = base + already;
1028uschar *cr;
1029int have = 0;
1030int ret;
1031int last = 0;
1032
1033/* For "PROXY UNKNOWN\r\n" we, at time of writing, expect to have read
1034up through the \r; for the _normal_ case, we haven't yet seen the \r. */
da88acae 1035
2c0f3ea1
JH
1036cr = memchr(base, '\r', already);
1037if (cr != NULL)
1038 {
1039 if ((cr - base) < already - 1)
da88acae 1040 {
2c0f3ea1
JH
1041 /* \r and presumed \n already within what we have; probably not
1042 actually proxy protocol, but abort cleanly. */
1043 return 0;
da88acae 1044 }
2c0f3ea1
JH
1045 /* \r is last character read, just need one more. */
1046 last = 1;
1047 }
1048
1049while (capacity > 0)
1050 {
1051 do { ret = recv(fd, to, 1, 0); } while (ret == -1 && errno == EINTR);
1052 if (ret == -1)
1053 return -1;
1054 have++;
1055 if (last)
1056 return have;
1057 if (*to == '\r')
1058 last = 1;
1059 capacity--;
1060 to++;
1061 }
1062
1063/* reached end without having room for a final newline, abort */
1064errno = EOVERFLOW;
1065return -1;
3f251b3c
PP
1066}
1067
a3c86431
TL
1068/*************************************************
1069* Setup host for proxy protocol *
1070*************************************************/
1071/* The function configures the connection based on a header from the
1072inbound host to use Proxy Protocol. The specification is very exact
1073so exit with an error if do not find the exact required pieces. This
1074includes an incorrect number of spaces separating args.
1075
1076Arguments: none
f267271d 1077Returns: Boolean success
a3c86431
TL
1078*/
1079
1811cb4c 1080static void
a3c86431
TL
1081setup_proxy_protocol_host()
1082{
1083union {
1084 struct {
1085 uschar line[108];
1086 } v1;
1087 struct {
1088 uschar sig[12];
36719342
TL
1089 uint8_t ver_cmd;
1090 uint8_t fam;
1091 uint16_t len;
a3c86431
TL
1092 union {
1093 struct { /* TCP/UDP over IPv4, len = 12 */
1094 uint32_t src_addr;
1095 uint32_t dst_addr;
1096 uint16_t src_port;
1097 uint16_t dst_port;
1098 } ip4;
1099 struct { /* TCP/UDP over IPv6, len = 36 */
1100 uint8_t src_addr[16];
1101 uint8_t dst_addr[16];
1102 uint16_t src_port;
1103 uint16_t dst_port;
1104 } ip6;
1105 struct { /* AF_UNIX sockets, len = 216 */
1106 uschar src_addr[108];
1107 uschar dst_addr[108];
1108 } unx;
1109 } addr;
1110 } v2;
1111} hdr;
1112
eb57651e
TL
1113/* Temp variables used in PPv2 address:port parsing */
1114uint16_t tmpport;
1115char tmpip[INET_ADDRSTRLEN];
1116struct sockaddr_in tmpaddr;
1117char tmpip6[INET6_ADDRSTRLEN];
1118struct sockaddr_in6 tmpaddr6;
1119
da88acae
PP
1120/* We can't read "all data until end" because while SMTP is
1121server-speaks-first, the TLS handshake is client-speaks-first, so for
1122TLS-on-connect ports the proxy protocol header will usually be immediately
1123followed by a TLS handshake, and with N TLS libraries, we can't reliably
1124reinject data for reading by those. So instead we first read "enough to be
1125safely read within the header, and figure out how much more to read".
1126For v1 we will later read to the end-of-line, for v2 we will read based upon
1127the stated length.
1128
1129The v2 sig is 12 octets, and another 4 gets us the length, so we know how much
1130data is needed total. For v1, where the line looks like:
1131PROXY TCPn L3src L3dest SrcPort DestPort \r\n
1132
1133However, for v1 there's also `PROXY UNKNOWN\r\n` which is only 15 octets.
1134We seem to support that. So, if we read 14 octets then we can tell if we're
1135v2 or v1. If we're v1, we can continue reading as normal.
1136
1137If we're v2, we can't slurp up the entire header. We need the length in the
113815th & 16th octets, then to read everything after that.
1139
1140So to safely handle v1 and v2, with client-sent-first supported correctly,
1141we have to do a minimum of 3 read calls, not 1. Eww.
1142*/
1143
1144#define PROXY_INITIAL_READ 14
1145#define PROXY_V2_HEADER_SIZE 16
1146#if PROXY_INITIAL_READ > PROXY_V2_HEADER_SIZE
1147# error Code bug in sizes of data to read for proxy usage
1148#endif
1149
eb57651e 1150int get_ok = 0;
f267271d
JH
1151int size, ret;
1152int fd = fileno(smtp_in);
36719342 1153const char v2sig[12] = "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A";
9e7e0f6a 1154uschar * iptype; /* To display debug info */
a3c86431 1155struct timeval tv;
a3bddaa8 1156struct timeval tvtmp;
f267271d 1157socklen_t vslen = sizeof(struct timeval);
1811cb4c 1158BOOL yield = FALSE;
a3c86431 1159
a3bddaa8 1160/* Save current socket timeout values */
f267271d 1161get_ok = getsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS &tvtmp, &vslen);
a3bddaa8 1162
a3c86431
TL
1163/* Proxy Protocol host must send header within a short time
1164(default 3 seconds) or it's considered invalid */
1165tv.tv_sec = PROXY_NEGOTIATION_TIMEOUT_SEC;
1166tv.tv_usec = PROXY_NEGOTIATION_TIMEOUT_USEC;
f267271d 1167if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS &tv, sizeof(tv)) < 0)
1811cb4c 1168 goto bad;
a3bddaa8 1169
a3c86431
TL
1170do
1171 {
eb57651e 1172 /* The inbound host was declared to be a Proxy Protocol host, so
2c0f3ea1
JH
1173 don't do a PEEK into the data, actually slurp up enough to be
1174 "safe". Can't take it all because TLS-on-connect clients follow
1175 immediately with TLS handshake. */
3f251b3c 1176 ret = recv(fd, &hdr, PROXY_INITIAL_READ, 0);
a3c86431
TL
1177 }
1178 while (ret == -1 && errno == EINTR);
1179
1180if (ret == -1)
f267271d 1181 goto proxyfail;
a3c86431 1182
da88acae
PP
1183/* For v2, handle reading the length, and then the rest. */
1184if ((ret == PROXY_INITIAL_READ) && (memcmp(&hdr.v2, v2sig, sizeof(v2sig)) == 0))
a3c86431 1185 {
da88acae
PP
1186 int retmore;
1187 uint8_t ver;
1188
1189 /* First get the length fields. */
1190 do
1191 {
1192 retmore = recv(fd, (uschar*)&hdr + ret, PROXY_V2_HEADER_SIZE - PROXY_INITIAL_READ, 0);
1193 } while (retmore == -1 && errno == EINTR);
1194 if (retmore == -1)
3f251b3c 1195 goto proxyfail;
da88acae 1196 ret += retmore;
3f251b3c
PP
1197
1198 ver = (hdr.v2.ver_cmd & 0xf0) >> 4;
36719342
TL
1199
1200 /* May 2014: haproxy combined the version and command into one byte to
2c0f3ea1
JH
1201 allow two full bytes for the length field in order to proxy SSL
1202 connections. SSL Proxy is not supported in this version of Exim, but
1203 must still separate values here. */
36719342
TL
1204
1205 if (ver != 0x02)
1206 {
1207 DEBUG(D_receive) debug_printf("Invalid Proxy Protocol version: %d\n", ver);
1208 goto proxyfail;
1209 }
da88acae 1210
36719342 1211 /* The v2 header will always be 16 bytes per the spec. */
5d036699 1212 size = 16 + ntohs(hdr.v2.len);
da88acae
PP
1213 DEBUG(D_receive) debug_printf("Detected PROXYv2 header, size %d (limit %d)\n",
1214 size, (int)sizeof(hdr));
1215
1216 /* We should now have 16 octets (PROXY_V2_HEADER_SIZE), and we know the total
1217 amount that we need. Double-check that the size is not unreasonable, then
1218 get the rest. */
1219 if (size > sizeof(hdr))
a3c86431 1220 {
da88acae 1221 DEBUG(D_receive) debug_printf("PROXYv2 header size unreasonably large; security attack?\n");
a3c86431
TL
1222 goto proxyfail;
1223 }
da88acae
PP
1224
1225 do
1226 {
1227 do
1228 {
1229 retmore = recv(fd, (uschar*)&hdr + ret, size-ret, 0);
1230 } while (retmore == -1 && errno == EINTR);
1231 if (retmore == -1)
1232 goto proxyfail;
1233 ret += retmore;
1234 DEBUG(D_receive) debug_printf("PROXYv2: have %d/%d required octets\n", ret, size);
1235 } while (ret < size);
1236
1237 } /* end scope for getting rest of data for v2 */
1238
1239/* At this point: if PROXYv2, we've read the exact size required for all data;
1240if PROXYv1 then we've read "less than required for any valid line" and should
1241read the rest". */
1242
1243if (ret >= 16 && memcmp(&hdr.v2, v2sig, 12) == 0)
1244 {
1245 uint8_t cmd = (hdr.v2.ver_cmd & 0x0f);
1246
36719342 1247 switch (cmd)
a3c86431
TL
1248 {
1249 case 0x01: /* PROXY command */
1250 switch (hdr.v2.fam)
1251 {
eb57651e
TL
1252 case 0x11: /* TCPv4 address type */
1253 iptype = US"IPv4";
1254 tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.src_addr;
5d036699
JH
1255 inet_ntop(AF_INET, &tmpaddr.sin_addr, CS &tmpip, sizeof(tmpip));
1256 if (!string_is_ip_address(US tmpip, NULL))
eb57651e
TL
1257 {
1258 DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
f267271d 1259 goto proxyfail;
eb57651e 1260 }
e6d2a989 1261 proxy_local_address = sender_host_address;
eb57651e
TL
1262 sender_host_address = string_copy(US tmpip);
1263 tmpport = ntohs(hdr.v2.addr.ip4.src_port);
e6d2a989 1264 proxy_local_port = sender_host_port;
eb57651e
TL
1265 sender_host_port = tmpport;
1266 /* Save dest ip/port */
1267 tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.dst_addr;
5d036699
JH
1268 inet_ntop(AF_INET, &tmpaddr.sin_addr, CS &tmpip, sizeof(tmpip));
1269 if (!string_is_ip_address(US tmpip, NULL))
eb57651e
TL
1270 {
1271 DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype);
f267271d 1272 goto proxyfail;
eb57651e 1273 }
7a2fa0bc 1274 proxy_external_address = string_copy(US tmpip);
eb57651e 1275 tmpport = ntohs(hdr.v2.addr.ip4.dst_port);
7a2fa0bc 1276 proxy_external_port = tmpport;
a3c86431 1277 goto done;
eb57651e
TL
1278 case 0x21: /* TCPv6 address type */
1279 iptype = US"IPv6";
1280 memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.src_addr, 16);
5d036699
JH
1281 inet_ntop(AF_INET6, &tmpaddr6.sin6_addr, CS &tmpip6, sizeof(tmpip6));
1282 if (!string_is_ip_address(US tmpip6, NULL))
eb57651e
TL
1283 {
1284 DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
f267271d 1285 goto proxyfail;
eb57651e 1286 }
e6d2a989 1287 proxy_local_address = sender_host_address;
eb57651e
TL
1288 sender_host_address = string_copy(US tmpip6);
1289 tmpport = ntohs(hdr.v2.addr.ip6.src_port);
e6d2a989 1290 proxy_local_port = sender_host_port;
eb57651e
TL
1291 sender_host_port = tmpport;
1292 /* Save dest ip/port */
1293 memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.dst_addr, 16);
5d036699
JH
1294 inet_ntop(AF_INET6, &tmpaddr6.sin6_addr, CS &tmpip6, sizeof(tmpip6));
1295 if (!string_is_ip_address(US tmpip6, NULL))
eb57651e
TL
1296 {
1297 DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype);
f267271d 1298 goto proxyfail;
eb57651e 1299 }
7a2fa0bc 1300 proxy_external_address = string_copy(US tmpip6);
eb57651e 1301 tmpport = ntohs(hdr.v2.addr.ip6.dst_port);
7a2fa0bc 1302 proxy_external_port = tmpport;
a3c86431 1303 goto done;
eb57651e
TL
1304 default:
1305 DEBUG(D_receive)
1306 debug_printf("Unsupported PROXYv2 connection type: 0x%02x\n",
1307 hdr.v2.fam);
1308 goto proxyfail;
a3c86431
TL
1309 }
1310 /* Unsupported protocol, keep local connection address */
1311 break;
1312 case 0x00: /* LOCAL command */
1313 /* Keep local connection address for LOCAL */
9e7e0f6a 1314 iptype = US"local";
a3c86431
TL
1315 break;
1316 default:
eb57651e 1317 DEBUG(D_receive)
36719342 1318 debug_printf("Unsupported PROXYv2 command: 0x%x\n", cmd);
a3c86431
TL
1319 goto proxyfail;
1320 }
1321 }
5d036699 1322else if (ret >= 8 && memcmp(hdr.v1.line, "PROXY", 5) == 0)
a3c86431 1323 {
3f251b3c
PP
1324 uschar *p;
1325 uschar *end;
a3c86431
TL
1326 uschar *sp; /* Utility variables follow */
1327 int tmp_port;
3f251b3c 1328 int r2;
a3c86431
TL
1329 char *endc;
1330
3f251b3c 1331 /* get the rest of the line */
da88acae 1332 r2 = swallow_until_crlf(fd, (uschar*)&hdr, ret, sizeof(hdr)-ret);
3f251b3c
PP
1333 if (r2 == -1)
1334 goto proxyfail;
1335 ret += r2;
1336
1337 p = string_copy(hdr.v1.line);
1338 end = memchr(p, '\r', ret - 1);
1339
da88acae 1340 if (!end || (end == (uschar*)&hdr + ret) || end[1] != '\n')
a3c86431
TL
1341 {
1342 DEBUG(D_receive) debug_printf("Partial or invalid PROXY header\n");
1343 goto proxyfail;
1344 }
1345 *end = '\0'; /* Terminate the string */
a5d4db40 1346 size = end + 2 - p; /* Skip header + CRLF */
a3c86431 1347 DEBUG(D_receive) debug_printf("Detected PROXYv1 header\n");
3f251b3c 1348 DEBUG(D_receive) debug_printf("Bytes read not within PROXY header: %d\n", ret - size);
a3c86431 1349 /* Step through the string looking for the required fields. Ensure
2c0f3ea1 1350 strict adherence to required formatting, exit for any error. */
a3c86431
TL
1351 p += 5;
1352 if (!isspace(*(p++)))
1353 {
1354 DEBUG(D_receive) debug_printf("Missing space after PROXY command\n");
1355 goto proxyfail;
1356 }
1357 if (!Ustrncmp(p, CCS"TCP4", 4))
1358 iptype = US"IPv4";
1359 else if (!Ustrncmp(p,CCS"TCP6", 4))
1360 iptype = US"IPv6";
1361 else if (!Ustrncmp(p,CCS"UNKNOWN", 7))
1362 {
1363 iptype = US"Unknown";
1364 goto done;
1365 }
1366 else
1367 {
1368 DEBUG(D_receive) debug_printf("Invalid TCP type\n");
1369 goto proxyfail;
1370 }
1371
1372 p += Ustrlen(iptype);
1373 if (!isspace(*(p++)))
1374 {
1375 DEBUG(D_receive) debug_printf("Missing space after TCP4/6 command\n");
1376 goto proxyfail;
1377 }
1378 /* Find the end of the arg */
1379 if ((sp = Ustrchr(p, ' ')) == NULL)
1380 {
1381 DEBUG(D_receive)
1382 debug_printf("Did not find proxied src %s\n", iptype);
1383 goto proxyfail;
1384 }
1385 *sp = '\0';
5d036699 1386 if(!string_is_ip_address(p, NULL))
a3c86431
TL
1387 {
1388 DEBUG(D_receive)
1389 debug_printf("Proxied src arg is not an %s address\n", iptype);
1390 goto proxyfail;
1391 }
e6d2a989 1392 proxy_local_address = sender_host_address;
a3c86431
TL
1393 sender_host_address = p;
1394 p = sp + 1;
1395 if ((sp = Ustrchr(p, ' ')) == NULL)
1396 {
1397 DEBUG(D_receive)
1398 debug_printf("Did not find proxy dest %s\n", iptype);
1399 goto proxyfail;
1400 }
1401 *sp = '\0';
5d036699 1402 if(!string_is_ip_address(p, NULL))
a3c86431
TL
1403 {
1404 DEBUG(D_receive)
1405 debug_printf("Proxy dest arg is not an %s address\n", iptype);
1406 goto proxyfail;
1407 }
7a2fa0bc 1408 proxy_external_address = p;
a3c86431
TL
1409 p = sp + 1;
1410 if ((sp = Ustrchr(p, ' ')) == NULL)
1411 {
1412 DEBUG(D_receive) debug_printf("Did not find proxied src port\n");
1413 goto proxyfail;
1414 }
1415 *sp = '\0';
5d036699 1416 tmp_port = strtol(CCS p, &endc, 10);
a3c86431
TL
1417 if (*endc || tmp_port == 0)
1418 {
1419 DEBUG(D_receive)
1420 debug_printf("Proxied src port '%s' not an integer\n", p);
1421 goto proxyfail;
1422 }
e6d2a989 1423 proxy_local_port = sender_host_port;
a3c86431
TL
1424 sender_host_port = tmp_port;
1425 p = sp + 1;
1426 if ((sp = Ustrchr(p, '\0')) == NULL)
1427 {
1428 DEBUG(D_receive) debug_printf("Did not find proxy dest port\n");
1429 goto proxyfail;
1430 }
5d036699 1431 tmp_port = strtol(CCS p, &endc, 10);
a3c86431
TL
1432 if (*endc || tmp_port == 0)
1433 {
1434 DEBUG(D_receive)
1435 debug_printf("Proxy dest port '%s' not an integer\n", p);
1436 goto proxyfail;
1437 }
7a2fa0bc 1438 proxy_external_port = tmp_port;
a3c86431 1439 /* Already checked for /r /n above. Good V1 header received. */
a3c86431
TL
1440 }
1441else
1442 {
1443 /* Wrong protocol */
eb57651e 1444 DEBUG(D_receive) debug_printf("Invalid proxy protocol version negotiation\n");
da88acae 1445 (void) swallow_until_crlf(fd, (uschar*)&hdr, ret, sizeof(hdr)-ret);
a3c86431
TL
1446 goto proxyfail;
1447 }
1448
1811cb4c
JH
1449done:
1450 DEBUG(D_receive)
1451 debug_printf("Valid %s sender from Proxy Protocol header\n", iptype);
1452 yield = proxy_session;
1453
1454/* Don't flush any potential buffer contents. Any input on proxyfail
1455should cause a synchronization failure */
1456
a3c86431 1457proxyfail:
1811cb4c 1458 restore_socket_timeout(fd, get_ok, &tvtmp, vslen);
a3c86431 1459
1811cb4c
JH
1460bad:
1461 if (yield)
1462 {
1463 sender_host_name = NULL;
1464 (void) host_name_lookup();
1465 host_build_sender_fullhost();
1466 }
1467 else
1468 {
1469 proxy_session_failed = TRUE;
1470 DEBUG(D_receive)
1471 debug_printf("Failure to extract proxied host, only QUIT allowed\n");
1472 }
1473
1474return;
a3c86431
TL
1475}
1476#endif
1477
059ec3d9
PH
1478/*************************************************
1479* Read one command line *
1480*************************************************/
1481
1482/* Strictly, SMTP commands coming over the net are supposed to end with CRLF.
1483There are sites that don't do this, and in any case internal SMTP probably
1484should check only for LF. Consequently, we check here for LF only. The line
1485ends up with [CR]LF removed from its end. If we get an overlong line, treat as
3ee512ff
PH
1486an unknown command. The command is read into the global smtp_cmd_buffer so that
1487it is available via $smtp_command.
059ec3d9
PH
1488
1489The character reading routine sets up a timeout for each block actually read
1490from the input (which may contain more than one command). We set up a special
1491signal handler that closes down the session on a timeout. Control does not
1492return when it runs.
1493
1494Arguments:
bd8fbe36
JH
1495 check_sync if TRUE, check synchronization rules if global option is TRUE
1496 buffer_lim maximum to buffer in lower layer
059ec3d9
PH
1497
1498Returns: a code identifying the command (enumerated above)
1499*/
1500
1501static int
bd8fbe36 1502smtp_read_command(BOOL check_sync, unsigned buffer_lim)
059ec3d9
PH
1503{
1504int c;
1505int ptr = 0;
1506smtp_cmd_list *p;
1507BOOL hadnull = FALSE;
1508
1509os_non_restarting_signal(SIGALRM, command_timeout_handler);
1510
bd8fbe36 1511while ((c = (receive_getc)(buffer_lim)) != '\n' && c != EOF)
059ec3d9 1512 {
bd8fbe36 1513 if (ptr >= SMTP_CMD_BUFFER_SIZE)
059ec3d9
PH
1514 {
1515 os_non_restarting_signal(SIGALRM, sigalrm_handler);
1516 return OTHER_CMD;
1517 }
1518 if (c == 0)
1519 {
1520 hadnull = TRUE;
1521 c = '?';
1522 }
3ee512ff 1523 smtp_cmd_buffer[ptr++] = c;
059ec3d9
PH
1524 }
1525
1526receive_linecount++; /* For BSMTP errors */
1527os_non_restarting_signal(SIGALRM, sigalrm_handler);
1528
1529/* If hit end of file, return pseudo EOF command. Whether we have a
1530part-line already read doesn't matter, since this is an error state. */
1531
1532if (c == EOF) return EOF_CMD;
1533
1534/* Remove any CR and white space at the end of the line, and terminate the
1535string. */
1536
3ee512ff
PH
1537while (ptr > 0 && isspace(smtp_cmd_buffer[ptr-1])) ptr--;
1538smtp_cmd_buffer[ptr] = 0;
059ec3d9 1539
3ee512ff 1540DEBUG(D_receive) debug_printf("SMTP<< %s\n", smtp_cmd_buffer);
059ec3d9
PH
1541
1542/* NULLs are not allowed in SMTP commands */
1543
1544if (hadnull) return BADCHAR_CMD;
1545
1546/* Scan command list and return identity, having set the data pointer
1547to the start of the actual data characters. Check for SMTP synchronization
1548if required. */
1549
1550for (p = cmd_list; p < cmd_list_end; p++)
1551 {
1811cb4c 1552#ifdef SUPPORT_PROXY
a3c86431 1553 /* Only allow QUIT command if Proxy Protocol parsing failed */
1811cb4c
JH
1554 if (proxy_session && proxy_session_failed && p->cmd != QUIT_CMD)
1555 continue;
1556#endif
2f460950
JH
1557 if ( p->len
1558 && strncmpic(smtp_cmd_buffer, US p->name, p->len) == 0
1559 && ( smtp_cmd_buffer[p->len-1] == ':' /* "mail from:" or "rcpt to:" */
1560 || smtp_cmd_buffer[p->len] == 0
1561 || smtp_cmd_buffer[p->len] == ' '
1562 ) )
059ec3d9
PH
1563 {
1564 if (smtp_inptr < smtp_inend && /* Outstanding input */
1565 p->cmd < sync_cmd_limit && /* Command should sync */
1566 check_sync && /* Local flag set */
1567 smtp_enforce_sync && /* Global flag set */
1568 sender_host_address != NULL && /* Not local input */
1569 !sender_host_notsocket) /* Really is a socket */
1570 return BADSYN_CMD;
1571
ca86f471
PH
1572 /* The variables $smtp_command and $smtp_command_argument point into the
1573 unmodified input buffer. A copy of the latter is taken for actual
1574 processing, so that it can be chopped up into separate parts if necessary,
1575 for example, when processing a MAIL command options such as SIZE that can
1576 follow the sender address. */
059ec3d9 1577
3ee512ff 1578 smtp_cmd_argument = smtp_cmd_buffer + p->len;
ca86f471
PH
1579 while (isspace(*smtp_cmd_argument)) smtp_cmd_argument++;
1580 Ustrcpy(smtp_data_buffer, smtp_cmd_argument);
1581 smtp_cmd_data = smtp_data_buffer;
059ec3d9
PH
1582
1583 /* Count non-mail commands from those hosts that are controlled in this
1584 way. The default is all hosts. We don't waste effort checking the list
1585 until we get a non-mail command, but then cache the result to save checking
1586 again. If there's a DEFER while checking the host, assume it's in the list.
1587
1588 Note that one instance of RSET, EHLO/HELO, and STARTTLS is allowed at the
1589 start of each incoming message by fiddling with the value in the table. */
1590
1591 if (!p->is_mail_cmd)
1592 {
1593 if (count_nonmail == TRUE_UNSET) count_nonmail =
1594 verify_check_host(&smtp_accept_max_nonmail_hosts) != FAIL;
1595 if (count_nonmail && ++nonmail_command_count > smtp_accept_max_nonmail)
1596 return TOO_MANY_NONMAIL_CMD;
1597 }
1598
ca86f471
PH
1599 /* If there is data for a command that does not expect it, generate the
1600 error here. */
059ec3d9 1601
ca86f471 1602 return (p->has_arg || *smtp_cmd_data == 0)? p->cmd : BADARG_CMD;
059ec3d9
PH
1603 }
1604 }
1605
cee5f132 1606#ifdef SUPPORT_PROXY
a3c86431
TL
1607/* Only allow QUIT command if Proxy Protocol parsing failed */
1608if (proxy_session && proxy_session_failed)
1609 return PROXY_FAIL_IGNORE_CMD;
1610#endif
1611
059ec3d9
PH
1612/* Enforce synchronization for unknown commands */
1613
1614if (smtp_inptr < smtp_inend && /* Outstanding input */
1615 check_sync && /* Local flag set */
1616 smtp_enforce_sync && /* Global flag set */
1617 sender_host_address != NULL && /* Not local input */
1618 !sender_host_notsocket) /* Really is a socket */
1619 return BADSYN_CMD;
1620
1621return OTHER_CMD;
1622}
1623
1624
1625
1626/*************************************************
1627* Forced closedown of call *
1628*************************************************/
1629
1630/* This function is called from log.c when Exim is dying because of a serious
1631disaster, and also from some other places. If an incoming non-batched SMTP
1632channel is open, it swallows the rest of the incoming message if in the DATA
1633phase, sends the reply string, and gives an error to all subsequent commands
1634except QUIT. The existence of an SMTP call is detected by the non-NULLness of
1635smtp_in.
1636
8f128379
PH
1637Arguments:
1638 message SMTP reply string to send, excluding the code
1639
059ec3d9
PH
1640Returns: nothing
1641*/
1642
1643void
1644smtp_closedown(uschar *message)
1645{
1646if (smtp_in == NULL || smtp_batched_input) return;
1647receive_swallow_smtp();
925ac8e4 1648smtp_printf("421 %s\r\n", FALSE, message);
059ec3d9 1649
bd8fbe36 1650for (;;) switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED))
059ec3d9 1651 {
60d10ce7
JH
1652 case EOF_CMD:
1653 return;
059ec3d9 1654
60d10ce7 1655 case QUIT_CMD:
925ac8e4 1656 smtp_printf("221 %s closing connection\r\n", FALSE, smtp_active_hostname);
60d10ce7
JH
1657 mac_smtp_fflush();
1658 return;
059ec3d9 1659
60d10ce7 1660 case RSET_CMD:
925ac8e4 1661 smtp_printf("250 Reset OK\r\n", FALSE);
60d10ce7 1662 break;
059ec3d9 1663
60d10ce7 1664 default:
925ac8e4 1665 smtp_printf("421 %s\r\n", FALSE, message);
60d10ce7 1666 break;
059ec3d9
PH
1667 }
1668}
1669
1670
1671
1672
1673/*************************************************
1674* Set up connection info for logging *
1675*************************************************/
1676
1677/* This function is called when logging information about an SMTP connection.
1678It sets up appropriate source information, depending on the type of connection.
dac79d3e
PH
1679If sender_fullhost is NULL, we are at a very early stage of the connection;
1680just use the IP address.
059ec3d9
PH
1681
1682Argument: none
1683Returns: a string describing the connection
1684*/
1685
1686uschar *
1687smtp_get_connection_info(void)
1688{
f5d25c2b
JH
1689const uschar * hostname = sender_fullhost
1690 ? sender_fullhost : sender_host_address;
dac79d3e 1691
059ec3d9 1692if (host_checking)
dac79d3e 1693 return string_sprintf("SMTP connection from %s", hostname);
059ec3d9
PH
1694
1695if (sender_host_unknown || sender_host_notsocket)
1696 return string_sprintf("SMTP connection from %s", sender_ident);
1697
1698if (is_inetd)
dac79d3e 1699 return string_sprintf("SMTP connection from %s (via inetd)", hostname);
059ec3d9 1700
6c6d6e48 1701if (LOGGING(incoming_interface) && interface_address != NULL)
dac79d3e 1702 return string_sprintf("SMTP connection from %s I=[%s]:%d", hostname,
059ec3d9
PH
1703 interface_address, interface_port);
1704
dac79d3e 1705return string_sprintf("SMTP connection from %s", hostname);
059ec3d9
PH
1706}
1707
1708
1709
e45a1c37 1710#ifdef SUPPORT_TLS
887291d2
JH
1711/* Append TLS-related information to a log line
1712
1713Arguments:
1714 s String under construction: allocated string to extend, or NULL
1715 sizep Pointer to current allocation size (update on return), or NULL
1716 ptrp Pointer to index for new entries in string (update on return), or NULL
1717
1718Returns: Allocated string or NULL
1719*/
e45a1c37
JH
1720static uschar *
1721s_tlslog(uschar * s, int * sizep, int * ptrp)
1722{
1723 int size = sizep ? *sizep : 0;
1724 int ptr = ptrp ? *ptrp : 0;
1725
6c6d6e48 1726 if (LOGGING(tls_cipher) && tls_in.cipher != NULL)
e45a1c37 1727 s = string_append(s, &size, &ptr, 2, US" X=", tls_in.cipher);
6c6d6e48 1728 if (LOGGING(tls_certificate_verified) && tls_in.cipher != NULL)
e45a1c37
JH
1729 s = string_append(s, &size, &ptr, 2, US" CV=",
1730 tls_in.certificate_verified? "yes":"no");
6c6d6e48 1731 if (LOGGING(tls_peerdn) && tls_in.peerdn != NULL)
e45a1c37
JH
1732 s = string_append(s, &size, &ptr, 3, US" DN=\"",
1733 string_printing(tls_in.peerdn), US"\"");
6c6d6e48 1734 if (LOGGING(tls_sni) && tls_in.sni != NULL)
e45a1c37
JH
1735 s = string_append(s, &size, &ptr, 3, US" SNI=\"",
1736 string_printing(tls_in.sni), US"\"");
1737
67d81c10
JH
1738 if (s)
1739 {
1740 s[ptr] = '\0';
1741 if (sizep) *sizep = size;
1742 if (ptrp) *ptrp = ptr;
1743 }
e45a1c37
JH
1744 return s;
1745}
1746#endif
1747
b4ed4da0
PH
1748/*************************************************
1749* Log lack of MAIL if so configured *
1750*************************************************/
1751
1752/* This function is called when an SMTP session ends. If the log selector
1753smtp_no_mail is set, write a log line giving some details of what has happened
1754in the SMTP session.
1755
1756Arguments: none
1757Returns: nothing
1758*/
1759
1760void
1761smtp_log_no_mail(void)
1762{
1763int size, ptr, i;
1764uschar *s, *sep;
1765
6c6d6e48 1766if (smtp_mailcmd_count > 0 || !LOGGING(smtp_no_mail))
b4ed4da0
PH
1767 return;
1768
1769s = NULL;
1770size = ptr = 0;
1771
1772if (sender_host_authenticated != NULL)
1773 {
1774 s = string_append(s, &size, &ptr, 2, US" A=", sender_host_authenticated);
1775 if (authenticated_id != NULL)
1776 s = string_append(s, &size, &ptr, 2, US":", authenticated_id);
1777 }
1778
1779#ifdef SUPPORT_TLS
e45a1c37 1780s = s_tlslog(s, &size, &ptr);
3f0945ff 1781#endif
b4ed4da0
PH
1782
1783sep = (smtp_connection_had[SMTP_HBUFF_SIZE-1] != SCH_NONE)?
1784 US" C=..." : US" C=";
1785for (i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++)
1786 {
1787 if (smtp_connection_had[i] != SCH_NONE)
1788 {
1789 s = string_append(s, &size, &ptr, 2, sep,
1790 smtp_names[smtp_connection_had[i]]);
1791 sep = US",";
1792 }
1793 }
1794
1795for (i = 0; i < smtp_ch_index; i++)
1796 {
1797 s = string_append(s, &size, &ptr, 2, sep, smtp_names[smtp_connection_had[i]]);
1798 sep = US",";
1799 }
1800
a09f2942 1801if (s) s[ptr] = 0; else s = US"";
a2673768
JH
1802log_write(0, LOG_MAIN, "no MAIL in %sSMTP connection from %s D=%s%s",
1803 tcp_in_fastopen ? US"TFO " : US"",
0f1a8658 1804 host_and_ident(FALSE), string_timesince(&smtp_connection_start), s);
b4ed4da0
PH
1805}
1806
1807
a09f2942
JH
1808/* Return list of recent smtp commands */
1809
1810uschar *
1811smtp_cmd_hist(void)
1812{
1813uschar * list = NULL;
1814int size = 0, len = 0, i;
1815
1816for (i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++)
1817 if (smtp_connection_had[i] != SCH_NONE)
1818 list = string_append_listele(list, &size, &len, ',',
1819 smtp_names[smtp_connection_had[i]]);
1820for (i = 0; i < smtp_ch_index; i++)
1821 list = string_append_listele(list, &size, &len, ',',
1822 smtp_names[smtp_connection_had[i]]);
1823return list ? list : US"";
1824}
1825
1826
1827
b4ed4da0 1828
059ec3d9
PH
1829/*************************************************
1830* Check HELO line and set sender_helo_name *
1831*************************************************/
1832
1833/* Check the format of a HELO line. The data for HELO/EHLO is supposed to be
1834the domain name of the sending host, or an ip literal in square brackets. The
4c04137d 1835argument is placed in sender_helo_name, which is in malloc store, because it
059ec3d9
PH
1836must persist over multiple incoming messages. If helo_accept_junk is set, this
1837host is permitted to send any old junk (needed for some broken hosts).
1838Otherwise, helo_allow_chars can be used for rogue characters in general
1839(typically people want to let in underscores).
1840
1841Argument:
1842 s the data portion of the line (already past any white space)
1843
1844Returns: TRUE or FALSE
1845*/
1846
1847static BOOL
1848check_helo(uschar *s)
1849{
1850uschar *start = s;
1851uschar *end = s + Ustrlen(s);
1852BOOL yield = helo_accept_junk;
1853
1854/* Discard any previous helo name */
1855
1856if (sender_helo_name != NULL)
1857 {
1858 store_free(sender_helo_name);
1859 sender_helo_name = NULL;
1860 }
1861
1862/* Skip tests if junk is permitted. */
1863
1864if (!yield)
1865 {
1866 /* Allow the new standard form for IPv6 address literals, namely,
1867 [IPv6:....], and because someone is bound to use it, allow an equivalent
1868 IPv4 form. Allow plain addresses as well. */
1869
1870 if (*s == '[')
1871 {
1872 if (end[-1] == ']')
1873 {
1874 end[-1] = 0;
1875 if (strncmpic(s, US"[IPv6:", 6) == 0)
1876 yield = (string_is_ip_address(s+6, NULL) == 6);
1877 else if (strncmpic(s, US"[IPv4:", 6) == 0)
1878 yield = (string_is_ip_address(s+6, NULL) == 4);
1879 else
1880 yield = (string_is_ip_address(s+1, NULL) != 0);
1881 end[-1] = ']';
1882 }
1883 }
1884
1885 /* Non-literals must be alpha, dot, hyphen, plus any non-valid chars
1886 that have been configured (usually underscore - sigh). */
1887
1888 else if (*s != 0)
1889 {
1890 yield = TRUE;
1891 while (*s != 0)
1892 {
1893 if (!isalnum(*s) && *s != '.' && *s != '-' &&
1894 Ustrchr(helo_allow_chars, *s) == NULL)
1895 {
1896 yield = FALSE;
1897 break;
1898 }
1899 s++;
1900 }
1901 }
1902 }
1903
1904/* Save argument if OK */
1905
1906if (yield) sender_helo_name = string_copy_malloc(start);
1907return yield;
1908}
1909
1910
1911
1912
1913
1914/*************************************************
1915* Extract SMTP command option *
1916*************************************************/
1917
ca86f471 1918/* This function picks the next option setting off the end of smtp_cmd_data. It
059ec3d9
PH
1919is called for MAIL FROM and RCPT TO commands, to pick off the optional ESMTP
1920things that can appear there.
1921
1922Arguments:
1923 name point this at the name
1924 value point this at the data string
1925
1926Returns: TRUE if found an option
1927*/
1928
1929static BOOL
1930extract_option(uschar **name, uschar **value)
1931{
1932uschar *n;
ca86f471 1933uschar *v = smtp_cmd_data + Ustrlen(smtp_cmd_data) - 1;
059ec3d9
PH
1934while (isspace(*v)) v--;
1935v[1] = 0;
d7a2c833
JH
1936while (v > smtp_cmd_data && *v != '=' && !isspace(*v))
1937 {
1938 /* Take care to not stop at a space embedded in a quoted local-part */
1939
1940 if (*v == '"') do v--; while (*v != '"' && v > smtp_cmd_data+1);
1941 v--;
1942 }
059ec3d9
PH
1943
1944n = v;
fd98a5c6 1945if (*v == '=')
a2673768 1946 {
fd98a5c6
JH
1947 while(isalpha(n[-1])) n--;
1948 /* RFC says SP, but TAB seen in wild and other major MTAs accept it */
1949 if (!isspace(n[-1])) return FALSE;
1950 n[-1] = 0;
a2673768 1951 }
fd98a5c6 1952else
a2673768 1953 {
fd98a5c6
JH
1954 n++;
1955 if (v == smtp_cmd_data) return FALSE;
a2673768 1956 }
059ec3d9 1957*v++ = 0;
fd98a5c6 1958*name = n;
059ec3d9
PH
1959*value = v;
1960return TRUE;
1961}
1962
1963
1964
1965
1966
059ec3d9
PH
1967/*************************************************
1968* Reset for new message *
1969*************************************************/
1970
1971/* This function is called whenever the SMTP session is reset from
1972within either of the setup functions.
1973
1974Argument: the stacking pool storage reset point
1975Returns: nothing
1976*/
1977
1978static void
1979smtp_reset(void *reset_point)
1980{
059ec3d9
PH
1981recipients_list = NULL;
1982rcpt_count = rcpt_defer_count = rcpt_fail_count =
1983 raw_recipients_count = recipients_count = recipients_list_max = 0;
2e0c1448 1984message_linecount = 0;
059ec3d9 1985message_size = -1;
71fafd95 1986acl_added_headers = NULL;
e7568d51 1987acl_removed_headers = NULL;
059ec3d9 1988queue_only_policy = FALSE;
2679d413
PH
1989rcpt_smtp_response = NULL;
1990rcpt_smtp_response_same = TRUE;
1991rcpt_in_progress = FALSE;
69358f02 1992deliver_freeze = FALSE; /* Can be set by ACL */
6a3f1455 1993freeze_tell = freeze_tell_config; /* Can be set by ACL */
29aba418 1994fake_response = OK; /* Can be set by ACL */
6951ac6c 1995#ifdef WITH_CONTENT_SCAN
8523533c
TK
1996no_mbox_unspool = FALSE; /* Can be set by ACL */
1997#endif
69358f02 1998submission_mode = FALSE; /* Can be set by ACL */
f4ee74ac 1999suppress_local_fixups = suppress_local_fixups_default; /* Can be set by ACL */
69358f02
PH
2000active_local_from_check = local_from_check; /* Can be set by ACL */
2001active_local_sender_retain = local_sender_retain; /* Can be set by ACL */
90341c71
JH
2002sending_ip_address = NULL;
2003return_path = sender_address = NULL;
2004sender_data = NULL; /* Can be set by ACL */
2005deliver_localpart_orig = NULL;
2006deliver_domain_orig = NULL;
2007callout_address = NULL;
2fe1a124 2008submission_name = NULL; /* Can be set by ACL */
059ec3d9
PH
2009raw_sender = NULL; /* After SMTP rewrite, before qualifying */
2010sender_address_unrewritten = NULL; /* Set only after verify rewrite */
2011sender_verified_list = NULL; /* No senders verified */
2012memset(sender_address_cache, 0, sizeof(sender_address_cache));
2013memset(sender_domain_cache, 0, sizeof(sender_domain_cache));
6c1c3d1d 2014
059ec3d9 2015authenticated_sender = NULL;
8523533c
TK
2016#ifdef EXPERIMENTAL_BRIGHTMAIL
2017bmi_run = 0;
2018bmi_verdicts = NULL;
2019#endif
90341c71 2020dnslist_domain = dnslist_matched = NULL;
80a47a2c 2021#ifndef DISABLE_DKIM
9e5d6b55 2022dkim_signers = NULL;
80a47a2c
TK
2023dkim_disable_verify = FALSE;
2024dkim_collect_input = FALSE;
f7572e5a 2025#endif
aa368db3
JH
2026dsn_ret = 0;
2027dsn_envid = NULL;
90341c71 2028deliver_host = deliver_host_address = NULL; /* Can be set by ACL */
aa368db3
JH
2029#ifndef DISABLE_PRDR
2030prdr_requested = FALSE;
2031#endif
8523533c
TK
2032#ifdef EXPERIMENTAL_SPF
2033spf_header_comment = NULL;
2034spf_received = NULL;
8e669ac1 2035spf_result = NULL;
8523533c
TK
2036spf_smtp_comment = NULL;
2037#endif
8c5d388a 2038#ifdef SUPPORT_I18N
d1a13eea
JH
2039message_smtputf8 = FALSE;
2040#endif
059ec3d9
PH
2041body_linecount = body_zerocount = 0;
2042
870f6ba8
TF
2043sender_rate = sender_rate_limit = sender_rate_period = NULL;
2044ratelimiters_mail = NULL; /* Updated by ratelimit ACL condition */
2045 /* Note that ratelimiters_conn persists across resets. */
2046
38a0a95f 2047/* Reset message ACL variables */
47ca6d6c 2048
38a0a95f 2049acl_var_m = NULL;
059ec3d9
PH
2050
2051/* The message body variables use malloc store. They may be set if this is
2052not the first message in an SMTP session and the previous message caused them
2053to be referenced in an ACL. */
2054
90341c71 2055if (message_body)
059ec3d9
PH
2056 {
2057 store_free(message_body);
2058 message_body = NULL;
2059 }
2060
90341c71 2061if (message_body_end)
059ec3d9
PH
2062 {
2063 store_free(message_body_end);
2064 message_body_end = NULL;
2065 }
2066
2067/* Warning log messages are also saved in malloc store. They are saved to avoid
2068repetition in the same message, but it seems right to repeat them for different
4e88a19f 2069messages. */
059ec3d9 2070
90341c71 2071while (acl_warn_logged)
059ec3d9
PH
2072 {
2073 string_item *this = acl_warn_logged;
2074 acl_warn_logged = acl_warn_logged->next;
2075 store_free(this);
2076 }
90341c71 2077store_reset(reset_point);
059ec3d9
PH
2078}
2079
2080
2081
2082
2083
2084/*************************************************
2085* Initialize for incoming batched SMTP message *
2086*************************************************/
2087
2088/* This function is called from smtp_setup_msg() in the case when
2089smtp_batched_input is true. This happens when -bS is used to pass a whole batch
2090of messages in one file with SMTP commands between them. All errors must be
2091reported by sending a message, and only MAIL FROM, RCPT TO, and DATA are
2092relevant. After an error on a sender, or an invalid recipient, the remainder
2093of the message is skipped. The value of received_protocol is already set.
2094
2095Argument: none
2096Returns: > 0 message successfully started (reached DATA)
2097 = 0 QUIT read or end of file reached
2098 < 0 should not occur
2099*/
2100
2101static int
2102smtp_setup_batch_msg(void)
2103{
2104int done = 0;
2105void *reset_point = store_get(0);
2106
2107/* Save the line count at the start of each transaction - single commands
2108like HELO and RSET count as whole transactions. */
2109
2110bsmtp_transaction_linecount = receive_linecount;
2111
2112if ((receive_feof)()) return 0; /* Treat EOF as QUIT */
2113
57cc2785 2114cancel_cutthrough_connection(TRUE, US"smtp_setup_batch_msg");
059ec3d9
PH
2115smtp_reset(reset_point); /* Reset for start of message */
2116
2117/* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
2118value. The values are 2 larger than the required yield of the function. */
2119
2120while (done <= 0)
2121 {
2122 uschar *errmess;
2123 uschar *recipient = NULL;
2124 int start, end, sender_domain, recipient_domain;
2125
bd8fbe36 2126 switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED))
059ec3d9
PH
2127 {
2128 /* The HELO/EHLO commands set sender_address_helo if they have
2129 valid data; otherwise they are ignored, except that they do
2130 a reset of the state. */
2131
2132 case HELO_CMD:
2133 case EHLO_CMD:
2134
ca86f471 2135 check_helo(smtp_cmd_data);
059ec3d9
PH
2136 /* Fall through */
2137
2138 case RSET_CMD:
57cc2785 2139 cancel_cutthrough_connection(TRUE, US"RSET received");
059ec3d9
PH
2140 smtp_reset(reset_point);
2141 bsmtp_transaction_linecount = receive_linecount;
2142 break;
2143
2144
2145 /* The MAIL FROM command requires an address as an operand. All we
2146 do here is to parse it for syntactic correctness. The form "<>" is
2147 a special case which converts into an empty string. The start/end
2148 pointers in the original are not used further for this address, as
2149 it is the canonical extracted address which is all that is kept. */
2150
2151 case MAIL_CMD:
474f71bf 2152 smtp_mailcmd_count++; /* Count for no-mail log */
059ec3d9
PH
2153 if (sender_address != NULL)
2154 /* The function moan_smtp_batch() does not return. */
3ee512ff 2155 moan_smtp_batch(smtp_cmd_buffer, "503 Sender already given");
059ec3d9 2156
ca86f471 2157 if (smtp_cmd_data[0] == 0)
059ec3d9 2158 /* The function moan_smtp_batch() does not return. */
3ee512ff 2159 moan_smtp_batch(smtp_cmd_buffer, "501 MAIL FROM must have an address operand");
059ec3d9
PH
2160
2161 /* Reset to start of message */
2162
57cc2785 2163 cancel_cutthrough_connection(TRUE, US"MAIL received");
059ec3d9
PH
2164 smtp_reset(reset_point);
2165
2166 /* Apply SMTP rewrite */
2167
2168 raw_sender = ((rewrite_existflags & rewrite_smtp) != 0)?
ca86f471
PH
2169 rewrite_one(smtp_cmd_data, rewrite_smtp|rewrite_smtp_sender, NULL, FALSE,
2170 US"", global_rewrite_rules) : smtp_cmd_data;
059ec3d9
PH
2171
2172 /* Extract the address; the TRUE flag allows <> as valid */
2173
2174 raw_sender =
2175 parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain,
2176 TRUE);
2177
2178 if (raw_sender == NULL)
2179 /* The function moan_smtp_batch() does not return. */
3ee512ff 2180 moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
059ec3d9
PH
2181
2182 sender_address = string_copy(raw_sender);
2183
2184 /* Qualify unqualified sender addresses if permitted to do so. */
2185
2186 if (sender_domain == 0 && sender_address[0] != 0 && sender_address[0] != '@')
2187 {
2188 if (allow_unqualified_sender)
2189 {
2190 sender_address = rewrite_address_qualify(sender_address, FALSE);
2191 DEBUG(D_receive) debug_printf("unqualified address %s accepted "
2192 "and rewritten\n", raw_sender);
2193 }
2194 /* The function moan_smtp_batch() does not return. */
3ee512ff 2195 else moan_smtp_batch(smtp_cmd_buffer, "501 sender address must contain "
059ec3d9
PH
2196 "a domain");
2197 }
2198 break;
2199
2200
2201 /* The RCPT TO command requires an address as an operand. All we do
2202 here is to parse it for syntactic correctness. There may be any number
2203 of RCPT TO commands, specifying multiple senders. We build them all into
2204 a data structure that is in argc/argv format. The start/end values
2205 given by parse_extract_address are not used, as we keep only the
2206 extracted address. */
2207
2208 case RCPT_CMD:
2209 if (sender_address == NULL)
2210 /* The function moan_smtp_batch() does not return. */
3ee512ff 2211 moan_smtp_batch(smtp_cmd_buffer, "503 No sender yet given");
059ec3d9 2212
ca86f471 2213 if (smtp_cmd_data[0] == 0)
059ec3d9 2214 /* The function moan_smtp_batch() does not return. */
3ee512ff 2215 moan_smtp_batch(smtp_cmd_buffer, "501 RCPT TO must have an address operand");
059ec3d9
PH
2216
2217 /* Check maximum number allowed */
2218
2219 if (recipients_max > 0 && recipients_count + 1 > recipients_max)
2220 /* The function moan_smtp_batch() does not return. */
3ee512ff 2221 moan_smtp_batch(smtp_cmd_buffer, "%s too many recipients",
059ec3d9
PH
2222 recipients_max_reject? "552": "452");
2223
2224 /* Apply SMTP rewrite, then extract address. Don't allow "<>" as a
2225 recipient address */
2226
2685d6e0
JH
2227 recipient = rewrite_existflags & rewrite_smtp
2228 ? rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
2229 global_rewrite_rules)
2230 : smtp_cmd_data;
059ec3d9 2231
059ec3d9
PH
2232 recipient = parse_extract_address(recipient, &errmess, &start, &end,
2233 &recipient_domain, FALSE);
059ec3d9 2234
2685d6e0 2235 if (!recipient)
059ec3d9 2236 /* The function moan_smtp_batch() does not return. */
3ee512ff 2237 moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
059ec3d9
PH
2238
2239 /* If the recipient address is unqualified, qualify it if permitted. Then
2240 add it to the list of recipients. */
2241
2242 if (recipient_domain == 0)
2243 {
2244 if (allow_unqualified_recipient)
2245 {
2246 DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
2247 recipient);
2248 recipient = rewrite_address_qualify(recipient, TRUE);
2249 }
2250 /* The function moan_smtp_batch() does not return. */
3ee512ff 2251 else moan_smtp_batch(smtp_cmd_buffer, "501 recipient address must contain "
059ec3d9
PH
2252 "a domain");
2253 }
2254 receive_add_recipient(recipient, -1);
2255 break;
2256
2257
2258 /* The DATA command is legal only if it follows successful MAIL FROM
2259 and RCPT TO commands. This function is complete when a valid DATA
2260 command is encountered. */
2261
2262 case DATA_CMD:
2263 if (sender_address == NULL || recipients_count <= 0)
2264 {
2265 /* The function moan_smtp_batch() does not return. */
2266 if (sender_address == NULL)
3ee512ff 2267 moan_smtp_batch(smtp_cmd_buffer,
059ec3d9
PH
2268 "503 MAIL FROM:<sender> command must precede DATA");
2269 else
3ee512ff 2270 moan_smtp_batch(smtp_cmd_buffer,
059ec3d9
PH
2271 "503 RCPT TO:<recipient> must precede DATA");
2272 }
2273 else
2274 {
2275 done = 3; /* DATA successfully achieved */
2276 message_ended = END_NOTENDED; /* Indicate in middle of message */
2277 }
2278 break;
2279
2280
2281 /* The VRFY, EXPN, HELP, ETRN, and NOOP commands are ignored. */
2282
2283 case VRFY_CMD:
2284 case EXPN_CMD:
2285 case HELP_CMD:
2286 case NOOP_CMD:
2287 case ETRN_CMD:
2288 bsmtp_transaction_linecount = receive_linecount;
2289 break;
2290
2291
2292 case EOF_CMD:
2293 case QUIT_CMD:
2294 done = 2;
2295 break;
2296
2297
2298 case BADARG_CMD:
2299 /* The function moan_smtp_batch() does not return. */
3ee512ff 2300 moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected argument data");
059ec3d9
PH
2301 break;
2302
2303
2304 case BADCHAR_CMD:
2305 /* The function moan_smtp_batch() does not return. */
3ee512ff 2306 moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected NULL in SMTP command");
059ec3d9
PH
2307 break;
2308
2309
2310 default:
2311 /* The function moan_smtp_batch() does not return. */
3ee512ff 2312 moan_smtp_batch(smtp_cmd_buffer, "500 Command unrecognized");
059ec3d9
PH
2313 break;
2314 }
2315 }
2316
2317return done - 2; /* Convert yield values */
2318}
2319
2320
2321
2322
cf0c6164
JH
2323static BOOL
2324smtp_log_tls_fail(uschar * errstr)
2325{
2326uschar * conn_info = smtp_get_connection_info();
2327
2328if (Ustrncmp(conn_info, US"SMTP ", 5) == 0) conn_info += 5;
2329/* I'd like to get separated H= here, but too hard for now */
2330
2331log_write(0, LOG_MAIN, "TLS error on %s %s", conn_info, errstr);
2332return FALSE;
2333}
2334
2335
a2673768
JH
2336
2337
2338#ifdef TCP_FASTOPEN
2339static void
2340tfo_in_check(void)
2341{
2342# ifdef TCP_INFO
2343struct tcp_info tinfo;
2344socklen_t len = sizeof(tinfo);
2345
2346if ( getsockopt(fileno(smtp_out), IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0
2347 && tinfo.tcpi_state == TCP_SYN_RECV
2348 )
2349 {
1ccd5f67 2350 DEBUG(D_receive) debug_printf("TCP_FASTOPEN mode connection (state TCP_SYN_RECV)\n");
a2673768
JH
2351 tcp_in_fastopen = TRUE;
2352 }
2353# endif
2354}
2355#endif
2356
2357
059ec3d9
PH
2358/*************************************************
2359* Start an SMTP session *
2360*************************************************/
2361
2362/* This function is called at the start of an SMTP session. Thereafter,
2363smtp_setup_msg() is called to initiate each separate message. This
2364function does host-specific testing, and outputs the banner line.
2365
2366Arguments: none
2367Returns: FALSE if the session can not continue; something has
2368 gone wrong, or the connection to the host is blocked
2369*/
2370
2371BOOL
2372smtp_start_session(void)
2373{
2374int size = 256;
4e88a19f
PH
2375int ptr, esclen;
2376uschar *user_msg, *log_msg;
2377uschar *code, *esc;
059ec3d9
PH
2378uschar *p, *s, *ss;
2379
0f1a8658 2380gettimeofday(&smtp_connection_start, NULL);
b4ed4da0
PH
2381for (smtp_ch_index = 0; smtp_ch_index < SMTP_HBUFF_SIZE; smtp_ch_index++)
2382 smtp_connection_had[smtp_ch_index] = SCH_NONE;
2383smtp_ch_index = 0;
2384
00f00ca5
PH
2385/* Default values for certain variables */
2386
059ec3d9 2387helo_seen = esmtp = helo_accept_junk = FALSE;
b4ed4da0 2388smtp_mailcmd_count = 0;
059ec3d9
PH
2389count_nonmail = TRUE_UNSET;
2390synprot_error_count = unknown_command_count = nonmail_command_count = 0;
2391smtp_delay_mail = smtp_rlm_base;
2392auth_advertised = FALSE;
2393pipelining_advertised = FALSE;
cf8b11a5 2394pipelining_enable = TRUE;
059ec3d9 2395sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING;
8f128379 2396smtp_exit_function_called = FALSE; /* For avoiding loop in not-quit exit */
059ec3d9 2397
33d73e3b
PH
2398/* If receiving by -bs from a trusted user, or testing with -bh, we allow
2399authentication settings from -oMaa to remain in force. */
2400
2401if (!host_checking && !sender_host_notsocket) sender_host_authenticated = NULL;
059ec3d9
PH
2402authenticated_by = NULL;
2403
2404#ifdef SUPPORT_TLS
817d9f57 2405tls_in.cipher = tls_in.peerdn = NULL;
9d1c15ef
JH
2406tls_in.ourcert = tls_in.peercert = NULL;
2407tls_in.sni = NULL;
44662487 2408tls_in.ocsp = OCSP_NOT_REQ;
059ec3d9
PH
2409tls_advertised = FALSE;
2410#endif
6c1c3d1d 2411dsn_advertised = FALSE;
8c5d388a 2412#ifdef SUPPORT_I18N
d1a13eea
JH
2413smtputf8_advertised = FALSE;
2414#endif
059ec3d9
PH
2415
2416/* Reset ACL connection variables */
2417
38a0a95f 2418acl_var_c = NULL;
059ec3d9 2419
ca86f471 2420/* Allow for trailing 0 in the command and data buffers. */
3ee512ff 2421
bd8fbe36 2422if (!(smtp_cmd_buffer = US malloc(2*SMTP_CMD_BUFFER_SIZE + 2)))
059ec3d9
PH
2423 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2424 "malloc() failed for SMTP command buffer");
40c90bca 2425
2416c261 2426smtp_cmd_buffer[0] = 0;
bd8fbe36 2427smtp_data_buffer = smtp_cmd_buffer + SMTP_CMD_BUFFER_SIZE + 1;
059ec3d9
PH
2428
2429/* For batched input, the protocol setting can be overridden from the
2430command line by a trusted caller. */
2431
2432if (smtp_batched_input)
2433 {
40c90bca 2434 if (!received_protocol) received_protocol = US"local-bsmtp";
059ec3d9
PH
2435 }
2436
2437/* For non-batched SMTP input, the protocol setting is forced here. It will be
2438reset later if any of EHLO/AUTH/STARTTLS are received. */
2439
2440else
2441 received_protocol =
e524074d 2442 (sender_host_address ? protocols : protocols_local) [pnormal];
059ec3d9
PH
2443
2444/* Set up the buffer for inputting using direct read() calls, and arrange to
2445call the local functions instead of the standard C ones. */
2446
5903c6ff 2447if (!(smtp_inbuffer = US malloc(IN_BUFFER_SIZE)))
059ec3d9 2448 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "malloc() failed for SMTP input buffer");
40c90bca 2449
059ec3d9 2450receive_getc = smtp_getc;
0d81dabc 2451receive_getbuf = smtp_getbuf;
584e96c6 2452receive_get_cache = smtp_get_cache;
059ec3d9
PH
2453receive_ungetc = smtp_ungetc;
2454receive_feof = smtp_feof;
2455receive_ferror = smtp_ferror;
58eb016e 2456receive_smtp_buffered = smtp_buffered;
059ec3d9
PH
2457smtp_inptr = smtp_inend = smtp_inbuffer;
2458smtp_had_eof = smtp_had_error = 0;
2459
2460/* Set up the message size limit; this may be host-specific */
2461
d45b1de8
PH
2462thismessage_size_limit = expand_string_integer(message_size_limit, TRUE);
2463if (expand_string_message != NULL)
059ec3d9
PH
2464 {
2465 if (thismessage_size_limit == -1)
2466 log_write(0, LOG_MAIN|LOG_PANIC, "unable to expand message_size_limit: "
2467 "%s", expand_string_message);
2468 else
2469 log_write(0, LOG_MAIN|LOG_PANIC, "invalid message_size_limit: "
2470 "%s", expand_string_message);
2471 smtp_closedown(US"Temporary local problem - please try later");
2472 return FALSE;
2473 }
2474
2475/* When a message is input locally via the -bs or -bS options, sender_host_
2476unknown is set unless -oMa was used to force an IP address, in which case it
2477is checked like a real remote connection. When -bs is used from inetd, this
2478flag is not set, causing the sending host to be checked. The code that deals
2479with IP source routing (if configured) is never required for -bs or -bS and
2480the flag sender_host_notsocket is used to suppress it.
2481
2482If smtp_accept_max and smtp_accept_reserve are set, keep some connections in
2483reserve for certain hosts and/or networks. */
2484
2485if (!sender_host_unknown)
2486 {
2487 int rc;
2488 BOOL reserved_host = FALSE;
2489
2490 /* Look up IP options (source routing info) on the socket if this is not an
2491 -oMa "host", and if any are found, log them and drop the connection.
2492
2493 Linux (and others now, see below) is different to everyone else, so there
2494 has to be some conditional compilation here. Versions of Linux before 2.1.15
2495 used a structure whose name was "options". Somebody finally realized that
2496 this name was silly, and it got changed to "ip_options". I use the
2497 newer name here, but there is a fudge in the script that sets up os.h
2498 to define a macro in older Linux systems.
2499
2500 Sigh. Linux is a fast-moving target. Another generation of Linux uses
2501 glibc 2, which has chosen ip_opts for the structure name. This is now
2502 really a glibc thing rather than a Linux thing, so the condition name
2503 has been changed to reflect this. It is relevant also to GNU/Hurd.
2504
2505 Mac OS 10.x (Darwin) is like the later glibc versions, but without the
2506 setting of the __GLIBC__ macro, so we can't detect it automatically. There's
2507 a special macro defined in the os.h file.
2508
2509 Some DGUX versions on older hardware appear not to support IP options at
2510 all, so there is now a general macro which can be set to cut out this
2511 support altogether.
2512
2513 How to do this properly in IPv6 is not yet known. */
2514
2515 #if !HAVE_IPV6 && !defined(NO_IP_OPTIONS)
2516
2517 #ifdef GLIBC_IP_OPTIONS
2518 #if (!defined __GLIBC__) || (__GLIBC__ < 2)
2519 #define OPTSTYLE 1
2520 #else
2521 #define OPTSTYLE 2
2522 #endif
2523 #elif defined DARWIN_IP_OPTIONS
2524 #define OPTSTYLE 2
2525 #else
2526 #define OPTSTYLE 3
2527 #endif
2528
2529 if (!host_checking && !sender_host_notsocket)
2530 {
2531 #if OPTSTYLE == 1
36a3b041 2532 EXIM_SOCKLEN_T optlen = sizeof(struct ip_options) + MAX_IPOPTLEN;
059ec3d9
PH
2533 struct ip_options *ipopt = store_get(optlen);
2534 #elif OPTSTYLE == 2
2535 struct ip_opts ipoptblock;
2536 struct ip_opts *ipopt = &ipoptblock;
36a3b041 2537 EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
059ec3d9
PH
2538 #else
2539 struct ipoption ipoptblock;
2540 struct ipoption *ipopt = &ipoptblock;
36a3b041 2541 EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
059ec3d9
PH
2542 #endif
2543
2544 /* Occasional genuine failures of getsockopt() have been seen - for
2545 example, "reset by peer". Therefore, just log and give up on this
2546 call, unless the error is ENOPROTOOPT. This error is given by systems
2547 that have the interfaces but not the mechanism - e.g. GNU/Hurd at the time
2548 of writing. So for that error, carry on - we just can't do an IP options
2549 check. */
2550
2551 DEBUG(D_receive) debug_printf("checking for IP options\n");
2552
5903c6ff 2553 if (getsockopt(fileno(smtp_out), IPPROTO_IP, IP_OPTIONS, US (ipopt),
059ec3d9
PH
2554 &optlen) < 0)
2555 {
2556 if (errno != ENOPROTOOPT)
2557 {
2558 log_write(0, LOG_MAIN, "getsockopt() failed from %s: %s",
2559 host_and_ident(FALSE), strerror(errno));
925ac8e4 2560 smtp_printf("451 SMTP service not available\r\n", FALSE);
059ec3d9
PH
2561 return FALSE;
2562 }
2563 }
2564
2565 /* Deal with any IP options that are set. On the systems I have looked at,
2566 the value of MAX_IPOPTLEN has been 40, meaning that there should never be
2567 more logging data than will fit in big_buffer. Nevertheless, after somebody
2568 questioned this code, I've added in some paranoid checking. */
2569
2570 else if (optlen > 0)
2571 {
2572 uschar *p = big_buffer;
2573 uschar *pend = big_buffer + big_buffer_size;
2574 uschar *opt, *adptr;
2575 int optcount;
2576 struct in_addr addr;
2577
2578 #if OPTSTYLE == 1
5903c6ff 2579 uschar *optstart = US (ipopt->__data);
059ec3d9 2580 #elif OPTSTYLE == 2
5903c6ff 2581 uschar *optstart = US (ipopt->ip_opts);
059ec3d9 2582 #else
5903c6ff 2583 uschar *optstart = US (ipopt->ipopt_list);
059ec3d9
PH
2584 #endif
2585
2586 DEBUG(D_receive) debug_printf("IP options exist\n");
2587
2588 Ustrcpy(p, "IP options on incoming call:");
2589 p += Ustrlen(p);
2590
2591 for (opt = optstart; opt != NULL &&
5903c6ff 2592 opt < US (ipopt) + optlen;)
059ec3d9
PH
2593 {
2594 switch (*opt)
2595 {
2596 case IPOPT_EOL:
2597 opt = NULL;
2598 break;
2599
2600 case IPOPT_NOP:
2601 opt++;
2602 break;
2603
2604 case IPOPT_SSRR:
2605 case IPOPT_LSRR:
2606 if (!string_format(p, pend-p, " %s [@%s",
2607 (*opt == IPOPT_SSRR)? "SSRR" : "LSRR",
2608 #if OPTSTYLE == 1
2609 inet_ntoa(*((struct in_addr *)(&(ipopt->faddr))))))
2610 #elif OPTSTYLE == 2
2611 inet_ntoa(ipopt->ip_dst)))
2612 #else
2613 inet_ntoa(ipopt->ipopt_dst)))
2614 #endif
2615 {
2616 opt = NULL;
2617 break;
2618 }
2619
2620 p += Ustrlen(p);
2621 optcount = (opt[1] - 3) / sizeof(struct in_addr);
2622 adptr = opt + 3;
2623 while (optcount-- > 0)
2624 {
2625 memcpy(&addr, adptr, sizeof(addr));
2626 if (!string_format(p, pend - p - 1, "%s%s",
2627 (optcount == 0)? ":" : "@", inet_ntoa(addr)))
2628 {
2629 opt = NULL;
2630 break;
2631 }
2632 p += Ustrlen(p);
2633 adptr += sizeof(struct in_addr);
2634 }
2635 *p++ = ']';
2636 opt += opt[1];
2637 break;
2638
2639 default:
2640 {
2641 int i;
2642 if (pend - p < 4 + 3*opt[1]) { opt = NULL; break; }
2643 Ustrcat(p, "[ ");
2644 p += 2;
2645 for (i = 0; i < opt[1]; i++)
5976eb99 2646 p += sprintf(CS p, "%2.2x ", opt[i]);
059ec3d9
PH
2647 *p++ = ']';
2648 }
2649 opt += opt[1];
2650 break;
2651 }
2652 }
2653
2654 *p = 0;
2655 log_write(0, LOG_MAIN, "%s", big_buffer);
2656
2657 /* Refuse any call with IP options. This is what tcpwrappers 7.5 does. */
2658
2659 log_write(0, LOG_MAIN|LOG_REJECT,
2660 "connection from %s refused (IP options)", host_and_ident(FALSE));
2661
925ac8e4 2662 smtp_printf("554 SMTP service not available\r\n", FALSE);
059ec3d9
PH
2663 return FALSE;
2664 }
2665
2666 /* Length of options = 0 => there are no options */
2667
2668 else DEBUG(D_receive) debug_printf("no IP options found\n");
2669 }
2670 #endif /* HAVE_IPV6 && !defined(NO_IP_OPTIONS) */
2671
2672 /* Set keep-alive in socket options. The option is on by default. This
2673 setting is an attempt to get rid of some hanging connections that stick in
2674 read() when the remote end (usually a dialup) goes away. */
2675
2676 if (smtp_accept_keepalive && !sender_host_notsocket)
2677 ip_keepalive(fileno(smtp_out), sender_host_address, FALSE);
2678
2679 /* If the current host matches host_lookup, set the name by doing a
2680 reverse lookup. On failure, sender_host_name will be NULL and
2681 host_lookup_failed will be TRUE. This may or may not be serious - optional
2682 checks later. */
2683
2684 if (verify_check_host(&host_lookup) == OK)
2685 {
2686 (void)host_name_lookup();
2687 host_build_sender_fullhost();
2688 }
2689
2690 /* Delay this until we have the full name, if it is looked up. */
2691
2692 set_process_info("handling incoming connection from %s",
2693 host_and_ident(FALSE));
2694
1ad6489e
JH
2695 /* Expand smtp_receive_timeout, if needed */
2696
2697 if (smtp_receive_timeout_s)
2698 {
2699 uschar * exp;
2700 if ( !(exp = expand_string(smtp_receive_timeout_s))
2701 || !(*exp)
2702 || (smtp_receive_timeout = readconf_readtime(exp, 0, FALSE)) < 0
2703 )
2704 log_write(0, LOG_MAIN|LOG_PANIC,
2705 "bad value for smtp_receive_timeout: '%s'", exp ? exp : US"");
2706 }
2707
059ec3d9
PH
2708 /* Test for explicit connection rejection */
2709
2710 if (verify_check_host(&host_reject_connection) == OK)
2711 {
2712 log_write(L_connection_reject, LOG_MAIN|LOG_REJECT, "refused connection "
2713 "from %s (host_reject_connection)", host_and_ident(FALSE));
925ac8e4 2714 smtp_printf("554 SMTP service not available\r\n", FALSE);
059ec3d9
PH
2715 return FALSE;
2716 }
2717
afb3eaaf
PH
2718 /* Test with TCP Wrappers if so configured. There is a problem in that
2719 hosts_ctl() returns 0 (deny) under a number of system failure circumstances,
2720 such as disks dying. In these cases, it is desirable to reject with a 4xx
2721 error instead of a 5xx error. There isn't a "right" way to detect such
2722 problems. The following kludge is used: errno is zeroed before calling
2723 hosts_ctl(). If the result is "reject", a 5xx error is given only if the
2724 value of errno is 0 or ENOENT (which happens if /etc/hosts.{allow,deny} does
2725 not exist). */
059ec3d9 2726
1811cb4c 2727#ifdef USE_TCP_WRAPPERS
afb3eaaf 2728 errno = 0;
1811cb4c 2729 if (!(tcp_wrappers_name = expand_string(tcp_wrappers_daemon_name)))
5dc43717
JJ
2730 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" "
2731 "(tcp_wrappers_name) failed: %s", string_printing(tcp_wrappers_name),
2732 expand_string_message);
1811cb4c 2733
5dc43717 2734 if (!hosts_ctl(tcp_wrappers_name,
1811cb4c
JH
2735 sender_host_name ? CS sender_host_name : STRING_UNKNOWN,
2736 sender_host_address ? CS sender_host_address : STRING_UNKNOWN,
2737 sender_ident ? CS sender_ident : STRING_UNKNOWN))
059ec3d9 2738 {
afb3eaaf
PH
2739 if (errno == 0 || errno == ENOENT)
2740 {
2741 HDEBUG(D_receive) debug_printf("tcp wrappers rejection\n");
2742 log_write(L_connection_reject,
2743 LOG_MAIN|LOG_REJECT, "refused connection from %s "
2744 "(tcp wrappers)", host_and_ident(FALSE));
925ac8e4 2745 smtp_printf("554 SMTP service not available\r\n", FALSE);
afb3eaaf
PH
2746 }
2747 else
2748 {
2749 int save_errno = errno;
2750 HDEBUG(D_receive) debug_printf("tcp wrappers rejected with unexpected "
2751 "errno value %d\n", save_errno);
2752 log_write(L_connection_reject,
2753 LOG_MAIN|LOG_REJECT, "temporarily refused connection from %s "
2754 "(tcp wrappers errno=%d)", host_and_ident(FALSE), save_errno);
925ac8e4 2755 smtp_printf("451 Temporary local problem - please try later\r\n", FALSE);
afb3eaaf 2756 }
059ec3d9
PH
2757 return FALSE;
2758 }
1811cb4c 2759#endif
059ec3d9 2760
b01dd148
PH
2761 /* Check for reserved slots. The value of smtp_accept_count has already been
2762 incremented to include this process. */
059ec3d9
PH
2763
2764 if (smtp_accept_max > 0 &&
b01dd148 2765 smtp_accept_count > smtp_accept_max - smtp_accept_reserve)
059ec3d9
PH
2766 {
2767 if ((rc = verify_check_host(&smtp_reserve_hosts)) != OK)
2768 {
2769 log_write(L_connection_reject,
2770 LOG_MAIN, "temporarily refused connection from %s: not in "
2771 "reserve list: connected=%d max=%d reserve=%d%s",
b01dd148 2772 host_and_ident(FALSE), smtp_accept_count - 1, smtp_accept_max,
059ec3d9
PH
2773 smtp_accept_reserve, (rc == DEFER)? " (lookup deferred)" : "");
2774 smtp_printf("421 %s: Too many concurrent SMTP connections; "
925ac8e4 2775 "please try again later\r\n", FALSE, smtp_active_hostname);
059ec3d9
PH
2776 return FALSE;
2777 }
2778 reserved_host = TRUE;
2779 }
2780
2781 /* If a load level above which only messages from reserved hosts are
2782 accepted is set, check the load. For incoming calls via the daemon, the
2783 check is done in the superior process if there are no reserved hosts, to
2784 save a fork. In all cases, the load average will already be available
2785 in a global variable at this point. */
2786
2787 if (smtp_load_reserve >= 0 &&
2788 load_average > smtp_load_reserve &&
2789 !reserved_host &&
2790 verify_check_host(&smtp_reserve_hosts) != OK)
2791 {
2792 log_write(L_connection_reject,
2793 LOG_MAIN, "temporarily refused connection from %s: not in "
2794 "reserve list and load average = %.2f", host_and_ident(FALSE),
2795 (double)load_average/1000.0);
925ac8e4 2796 smtp_printf("421 %s: Too much load; please try again later\r\n", FALSE,
059ec3d9
PH
2797 smtp_active_hostname);
2798 return FALSE;
2799 }
2800
2801 /* Determine whether unqualified senders or recipients are permitted
2802 for this host. Unfortunately, we have to do this every time, in order to
2803 set the flags so that they can be inspected when considering qualifying
2804 addresses in the headers. For a site that permits no qualification, this
2805 won't take long, however. */
2806
2807 allow_unqualified_sender =
2808 verify_check_host(&sender_unqualified_hosts) == OK;
2809
2810 allow_unqualified_recipient =
2811 verify_check_host(&recipient_unqualified_hosts) == OK;
2812
2813 /* Determine whether HELO/EHLO is required for this host. The requirement
2814 can be hard or soft. */
2815
2816 helo_required = verify_check_host(&helo_verify_hosts) == OK;
2817 if (!helo_required)
2818 helo_verify = verify_check_host(&helo_try_verify_hosts) == OK;
2819
2820 /* Determine whether this hosts is permitted to send syntactic junk
2821 after a HELO or EHLO command. */
2822
2823 helo_accept_junk = verify_check_host(&helo_accept_junk_hosts) == OK;
2824 }
2825
2826/* For batch SMTP input we are now done. */
2827
2828if (smtp_batched_input) return TRUE;
2829
a3c86431
TL
2830/* If valid Proxy Protocol source is connecting, set up session.
2831 * Failure will not allow any SMTP function other than QUIT. */
1811cb4c
JH
2832
2833#ifdef SUPPORT_PROXY
a3c86431
TL
2834proxy_session = FALSE;
2835proxy_session_failed = FALSE;
2836if (check_proxy_protocol_host())
1811cb4c
JH
2837 setup_proxy_protocol_host();
2838#endif
2839
2840 /* Start up TLS if tls_on_connect is set. This is for supporting the legacy
2841 smtps port for use with older style SSL MTAs. */
2842
2843#ifdef SUPPORT_TLS
cf0c6164
JH
2844 if (tls_in.on_connect && tls_server_start(tls_require_ciphers, &user_msg) != OK)
2845 return smtp_log_tls_fail(user_msg);
a3c86431
TL
2846#endif
2847
1811cb4c 2848/* Run the connect ACL if it exists */
059ec3d9 2849
4e88a19f 2850user_msg = NULL;
3cc3f762 2851if (acl_smtp_connect)
059ec3d9
PH
2852 {
2853 int rc;
3cc3f762
JH
2854 if ((rc = acl_check(ACL_WHERE_CONNECT, NULL, acl_smtp_connect, &user_msg,
2855 &log_msg)) != OK)
059ec3d9 2856 {
3cc3f762 2857 (void) smtp_handle_acl_fail(ACL_WHERE_CONNECT, rc, user_msg, log_msg);
059ec3d9
PH
2858 return FALSE;
2859 }
2860 }
2861
2862/* Output the initial message for a two-way SMTP connection. It may contain
2863newlines, which then cause a multi-line response to be given. */
2864
4e88a19f
PH
2865code = US"220"; /* Default status code */
2866esc = US""; /* Default extended status code */
2867esclen = 0; /* Length of esc */
2868
d4ff61d1 2869if (!user_msg)
4e88a19f 2870 {
d4ff61d1 2871 if (!(s = expand_string(smtp_banner)))
4e88a19f
PH
2872 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" (smtp_banner) "
2873 "failed: %s", smtp_banner, expand_string_message);
2874 }
2875else
2876 {
2877 int codelen = 3;
2878 s = user_msg;
4f6ae5c3 2879 smtp_message_code(&code, &codelen, &s, NULL, TRUE);
d6a96edc 2880 if (codelen > 4)
4e88a19f
PH
2881 {
2882 esc = code + 4;
2883 esclen = codelen - 4;
2884 }
2885 }
059ec3d9
PH
2886
2887/* Remove any terminating newlines; might as well remove trailing space too */
2888
2889p = s + Ustrlen(s);
2890while (p > s && isspace(p[-1])) p--;
2891*p = 0;
2892
2893/* It seems that CC:Mail is braindead, and assumes that the greeting message
2894is all contained in a single IP packet. The original code wrote out the
2895greeting using several calls to fprint/fputc, and on busy servers this could
2896cause it to be split over more than one packet - which caused CC:Mail to fall
2897over when it got the second part of the greeting after sending its first
2898command. Sigh. To try to avoid this, build the complete greeting message
2899first, and output it in one fell swoop. This gives a better chance of it
2900ending up as a single packet. */
2901
2902ss = store_get(size);
2903ptr = 0;
2904
2905p = s;
2906do /* At least once, in case we have an empty string */
2907 {
2908 int len;
2909 uschar *linebreak = Ustrchr(p, '\n');
c2f669a4 2910 ss = string_catn(ss, &size, &ptr, code, 3);
059ec3d9
PH
2911 if (linebreak == NULL)
2912 {
2913 len = Ustrlen(p);
c2f669a4 2914 ss = string_catn(ss, &size, &ptr, US" ", 1);
059ec3d9
PH
2915 }
2916 else
2917 {
2918 len = linebreak - p;
c2f669a4 2919 ss = string_catn(ss, &size, &ptr, US"-", 1);
059ec3d9 2920 }
c2f669a4
JH
2921 ss = string_catn(ss, &size, &ptr, esc, esclen);
2922 ss = string_catn(ss, &size, &ptr, p, len);
2923 ss = string_catn(ss, &size, &ptr, US"\r\n", 2);
059ec3d9
PH
2924 p += len;
2925 if (linebreak != NULL) p++;
2926 }
2927while (*p != 0);
2928
2929ss[ptr] = 0; /* string_cat leaves room for this */
2930
2931/* Before we write the banner, check that there is no input pending, unless
2932this synchronisation check is disabled. */
2933
a14e5636 2934if (!check_sync())
059ec3d9 2935 {
40525d07
JH
2936 unsigned n = smtp_inend - smtp_inptr;
2937 if (n > 32) n = 32;
2938
a14e5636
PH
2939 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol "
2940 "synchronization error (input sent without waiting for greeting): "
2941 "rejected connection from %s input=\"%s\"", host_and_ident(TRUE),
40525d07 2942 string_printing(string_copyn(smtp_inptr, n)));
925ac8e4 2943 smtp_printf("554 SMTP synchronization error\r\n", FALSE);
a14e5636 2944 return FALSE;
059ec3d9
PH
2945 }
2946
2947/* Now output the banner */
2948
925ac8e4 2949smtp_printf("%s", FALSE, ss);
a2673768
JH
2950
2951/* Attempt to see if we sent the banner before the last ACK of the 3-way
2952handshake arrived. If so we must have managed a TFO. */
2953
2954#ifdef TCP_FASTOPEN
2955tfo_in_check();
2956#endif
2957
059ec3d9
PH
2958return TRUE;
2959}
2960
2961
2962
2963
2964
2965/*************************************************
2966* Handle SMTP syntax and protocol errors *
2967*************************************************/
2968
2969/* Write to the log for SMTP syntax errors in incoming commands, if configured
2970to do so. Then transmit the error response. The return value depends on the
2971number of syntax and protocol errors in this SMTP session.
2972
2973Arguments:
2974 type error type, given as a log flag bit
2975 code response code; <= 0 means don't send a response
2976 data data to reflect in the response (can be NULL)
2977 errmess the error message
2978
2979Returns: -1 limit of syntax/protocol errors NOT exceeded
2980 +1 limit of syntax/protocol errors IS exceeded
2981
2982These values fit in with the values of the "done" variable in the main
2983processing loop in smtp_setup_msg(). */
2984
2985static int
2986synprot_error(int type, int code, uschar *data, uschar *errmess)
2987{
2988int yield = -1;
2989
2990log_write(type, LOG_MAIN, "SMTP %s error in \"%s\" %s %s",
2991 (type == L_smtp_syntax_error)? "syntax" : "protocol",
3ee512ff 2992 string_printing(smtp_cmd_buffer), host_and_ident(TRUE), errmess);
059ec3d9
PH
2993
2994if (++synprot_error_count > smtp_max_synprot_errors)
2995 {
2996 yield = 1;
2997 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
2998 "syntax or protocol errors (last command was \"%s\")",
0ebc4d69 2999 host_and_ident(FALSE), string_printing(smtp_cmd_buffer));
059ec3d9
PH
3000 }
3001
3002if (code > 0)
3003 {
925ac8e4
JH
3004 smtp_printf("%d%c%s%s%s\r\n", FALSE, code, yield == 1 ? '-' : ' ',
3005 data ? data : US"", data ? US": " : US"", errmess);
059ec3d9 3006 if (yield == 1)
925ac8e4 3007 smtp_printf("%d Too many syntax or protocol errors\r\n", FALSE, code);
059ec3d9
PH
3008 }
3009
3010return yield;
3011}
3012
3013
3014
3015
059ec3d9
PH
3016/*************************************************
3017* Send SMTP response, possibly multiline *
3018*************************************************/
3019
3020/* There are, it seems, broken clients out there that cannot handle multiline
3021responses. If no_multiline_responses is TRUE (it can be set from an ACL), we
3022output nothing for non-final calls, and only the first line for anything else.
3023
3024Arguments:
a5bd321b 3025 code SMTP code, may involve extended status codes
d6a96edc 3026 codelen length of smtp code; if > 4 there's an ESC
059ec3d9
PH
3027 final FALSE if the last line isn't the final line
3028 msg message text, possibly containing newlines
3029
3030Returns: nothing
3031*/
3032
3033void
a5bd321b 3034smtp_respond(uschar* code, int codelen, BOOL final, uschar *msg)
059ec3d9 3035{
a5bd321b
PH
3036int esclen = 0;
3037uschar *esc = US"";
3038
059ec3d9
PH
3039if (!final && no_multiline_responses) return;
3040
d6a96edc 3041if (codelen > 4)
a5bd321b
PH
3042 {
3043 esc = code + 4;
3044 esclen = codelen - 4;
3045 }
3046
2679d413
PH
3047/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
3048have had the same. Note: this code is also present in smtp_printf(). It would
3049be tidier to have it only in one place, but when it was added, it was easier to
3050do it that way, so as not to have to mess with the code for the RCPT command,
3051which sometimes uses smtp_printf() and sometimes smtp_respond(). */
3052
3053if (rcpt_in_progress)
3054 {
3055 if (rcpt_smtp_response == NULL)
3056 rcpt_smtp_response = string_copy(msg);
3057 else if (rcpt_smtp_response_same &&
3058 Ustrcmp(rcpt_smtp_response, msg) != 0)
3059 rcpt_smtp_response_same = FALSE;
3060 rcpt_in_progress = FALSE;
3061 }
3062
e5de01f0 3063/* Now output the message, splitting it up into multiple lines if necessary.
925ac8e4
JH
3064We only handle pipelining these responses as far as nonfinal/final groups,
3065not the whole MAIL/RCPT/DATA response set. */
2679d413 3066
059ec3d9
PH
3067for (;;)
3068 {
3069 uschar *nl = Ustrchr(msg, '\n');
3070 if (nl == NULL)
3071 {
925ac8e4 3072 smtp_printf("%.3s%c%.*s%s\r\n", !final, code, final ? ' ':'-', esclen, esc, msg);
059ec3d9
PH
3073 return;
3074 }
3075 else if (nl[1] == 0 || no_multiline_responses)
3076 {
925ac8e4 3077 smtp_printf("%.3s%c%.*s%.*s\r\n", !final, code, final ? ' ':'-', esclen, esc,
a5bd321b 3078 (int)(nl - msg), msg);
059ec3d9
PH
3079 return;
3080 }
3081 else
3082 {
925ac8e4 3083 smtp_printf("%.3s-%.*s%.*s\r\n", TRUE, code, esclen, esc, (int)(nl - msg), msg);
059ec3d9
PH
3084 msg = nl + 1;
3085 while (isspace(*msg)) msg++;
3086 }
3087 }
3088}
3089
3090
3091
3092
4e88a19f
PH
3093/*************************************************
3094* Parse user SMTP message *
3095*************************************************/
3096
3097/* This function allows for user messages overriding the response code details
3098by providing a suitable response code string at the start of the message
3099user_msg. Check the message for starting with a response code and optionally an
3100extended status code. If found, check that the first digit is valid, and if so,
3101change the code pointer and length to use the replacement. An invalid code
3102causes a panic log; in this case, if the log messages is the same as the user
3103message, we must also adjust the value of the log message to show the code that
3104is actually going to be used (the original one).
3105
3106This function is global because it is called from receive.c as well as within
3107this module.
3108
d6a96edc
PH
3109Note that the code length returned includes the terminating whitespace
3110character, which is always included in the regex match.
3111
4e88a19f
PH
3112Arguments:
3113 code SMTP code, may involve extended status codes
d6a96edc 3114 codelen length of smtp code; if > 4 there's an ESC
4e88a19f
PH
3115 msg message text
3116 log_msg optional log message, to be adjusted with the new SMTP code
4f6ae5c3 3117 check_valid if true, verify the response code
4e88a19f
PH
3118
3119Returns: nothing
3120*/
3121
3122void
4f6ae5c3
JH
3123smtp_message_code(uschar **code, int *codelen, uschar **msg, uschar **log_msg,
3124 BOOL check_valid)
4e88a19f
PH
3125{
3126int n;
3127int ovector[3];
3128
4f6ae5c3 3129if (!msg || !*msg) return;
4e88a19f 3130
4f6ae5c3
JH
3131if ((n = pcre_exec(regex_smtp_code, NULL, CS *msg, Ustrlen(*msg), 0,
3132 PCRE_EOPT, ovector, sizeof(ovector)/sizeof(int))) < 0) return;
4e88a19f 3133
4f6ae5c3 3134if (check_valid && (*msg)[0] != (*code)[0])
4e88a19f
PH
3135 {
3136 log_write(0, LOG_MAIN|LOG_PANIC, "configured error code starts with "
3137 "incorrect digit (expected %c) in \"%s\"", (*code)[0], *msg);
3138 if (log_msg != NULL && *log_msg == *msg)
3139 *log_msg = string_sprintf("%s %s", *code, *log_msg + ovector[1]);
3140 }
3141else
3142 {
3143 *code = *msg;
3144 *codelen = ovector[1]; /* Includes final space */
3145 }
3146*msg += ovector[1]; /* Chop the code off the message */
3147return;
3148}
3149
3150
3151
3152
059ec3d9
PH
3153/*************************************************
3154* Handle an ACL failure *
3155*************************************************/
3156
3157/* This function is called when acl_check() fails. As well as calls from within
3158this module, it is called from receive.c for an ACL after DATA. It sorts out
3159logging the incident, and sets up the error response. A message containing
3160newlines is turned into a multiline SMTP response, but for logging, only the
3161first line is used.
3162
a5bd321b
PH
3163There's a table of default permanent failure response codes to use in
3164globals.c, along with the table of names. VFRY is special. Despite RFC1123 it
3165defaults disabled in Exim. However, discussion in connection with RFC 821bis
3166(aka RFC 2821) has concluded that the response should be 252 in the disabled
3167state, because there are broken clients that try VRFY before RCPT. A 5xx
3168response should be given only when the address is positively known to be
4f6ae5c3
JH
3169undeliverable. Sigh. We return 252 if there is no VRFY ACL or it provides
3170no explicit code, but if there is one we let it know best.
3171Also, for ETRN, 458 is given on refusal, and for AUTH, 503.
a5bd321b
PH
3172
3173From Exim 4.63, it is possible to override the response code details by
3174providing a suitable response code string at the start of the message provided
3175in user_msg. The code's first digit is checked for validity.
059ec3d9
PH
3176
3177Arguments:
4f6ae5c3
JH
3178 where where the ACL was called from
3179 rc the failure code
3180 user_msg a message that can be included in an SMTP response
3181 log_msg a message for logging
059ec3d9
PH
3182
3183Returns: 0 in most cases
3184 2 if the failure code was FAIL_DROP, in which case the
3185 SMTP connection should be dropped (this value fits with the
3186 "done" variable in smtp_setup_msg() below)
3187*/
3188
3189int
3190smtp_handle_acl_fail(int where, int rc, uschar *user_msg, uschar *log_msg)
3191{
059ec3d9 3192BOOL drop = rc == FAIL_DROP;
a5bd321b 3193int codelen = 3;
a5bd321b 3194uschar *smtp_code;
059ec3d9
PH
3195uschar *lognl;
3196uschar *sender_info = US"";
64ffc24f 3197uschar *what =
8523533c 3198#ifdef WITH_CONTENT_SCAN
3cc3f762 3199 where == ACL_WHERE_MIME ? US"during MIME ACL checks" :
8e669ac1 3200#endif
3cc3f762
JH
3201 where == ACL_WHERE_PREDATA ? US"DATA" :
3202 where == ACL_WHERE_DATA ? US"after DATA" :
8ccd00b1 3203#ifndef DISABLE_PRDR
3cc3f762 3204 where == ACL_WHERE_PRDR ? US"after DATA PRDR" :
fd98a5c6 3205#endif
3cc3f762
JH
3206 smtp_cmd_data ?
3207 string_sprintf("%s %s", acl_wherenames[where], smtp_cmd_data) :
3208 string_sprintf("%s in \"connect\" ACL", acl_wherenames[where]);
059ec3d9
PH
3209
3210if (drop) rc = FAIL;
3211
4e88a19f 3212/* Set the default SMTP code, and allow a user message to change it. */
a5bd321b 3213
4f6ae5c3
JH
3214smtp_code = rc == FAIL ? acl_wherecodes[where] : US"451";
3215smtp_message_code(&smtp_code, &codelen, &user_msg, &log_msg,
3216 where != ACL_WHERE_VRFY);
a5bd321b 3217
059ec3d9
PH
3218/* We used to have sender_address here; however, there was a bug that was not
3219updating sender_address after a rewrite during a verify. When this bug was
3220fixed, sender_address at this point became the rewritten address. I'm not sure
3221this is what should be logged, so I've changed to logging the unrewritten
3222address to retain backward compatibility. */
3223
8523533c 3224#ifndef WITH_CONTENT_SCAN
059ec3d9 3225if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA)
8523533c
TK
3226#else
3227if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA || where == ACL_WHERE_MIME)
3228#endif
059ec3d9 3229 {
b98bb9ac
PP
3230 sender_info = string_sprintf("F=<%s>%s%s%s%s ",
3231 sender_address_unrewritten ? sender_address_unrewritten : sender_address,
3232 sender_host_authenticated ? US" A=" : US"",
3233 sender_host_authenticated ? sender_host_authenticated : US"",
3234 sender_host_authenticated && authenticated_id ? US":" : US"",
3235 sender_host_authenticated && authenticated_id ? authenticated_id : US""
3236 );
059ec3d9
PH
3237 }
3238
3239/* If there's been a sender verification failure with a specific message, and
3240we have not sent a response about it yet, do so now, as a preliminary line for
278c6e6c
PH
3241failures, but not defers. However, always log it for defer, and log it for fail
3242unless the sender_verify_fail log selector has been turned off. */
059ec3d9 3243
02b41d71 3244if (sender_verified_failed &&
059ec3d9
PH
3245 !testflag(sender_verified_failed, af_sverify_told))
3246 {
2679d413
PH
3247 BOOL save_rcpt_in_progress = rcpt_in_progress;
3248 rcpt_in_progress = FALSE; /* So as not to treat these as the error */
3249
059ec3d9
PH
3250 setflag(sender_verified_failed, af_sverify_told);
3251
6c6d6e48 3252 if (rc != FAIL || LOGGING(sender_verify_fail))
278c6e6c
PH
3253 log_write(0, LOG_MAIN|LOG_REJECT, "%s sender verify %s for <%s>%s",
3254 host_and_ident(TRUE),
3255 ((sender_verified_failed->special_action & 255) == DEFER)? "defer":"fail",
3256 sender_verified_failed->address,
3257 (sender_verified_failed->message == NULL)? US"" :
3258 string_sprintf(": %s", sender_verified_failed->message));
059ec3d9 3259
02b41d71 3260 if (rc == FAIL && sender_verified_failed->user_message)
a5bd321b 3261 smtp_respond(smtp_code, codelen, FALSE, string_sprintf(
059ec3d9
PH
3262 testflag(sender_verified_failed, af_verify_pmfail)?
3263 "Postmaster verification failed while checking <%s>\n%s\n"
3264 "Several RFCs state that you are required to have a postmaster\n"
3265 "mailbox for each mail domain. This host does not accept mail\n"
3266 "from domains whose servers reject the postmaster address."
3267 :
3268 testflag(sender_verified_failed, af_verify_nsfail)?
3269 "Callback setup failed while verifying <%s>\n%s\n"
3270 "The initial connection, or a HELO or MAIL FROM:<> command was\n"
3271 "rejected. Refusing MAIL FROM:<> does not help fight spam, disregards\n"
3272 "RFC requirements, and stops you from receiving standard bounce\n"
3273 "messages. This host does not accept mail from domains whose servers\n"
3274 "refuse bounces."
3275 :
3276 "Verification failed for <%s>\n%s",
3277 sender_verified_failed->address,
3278 sender_verified_failed->user_message));
2679d413
PH
3279
3280 rcpt_in_progress = save_rcpt_in_progress;
059ec3d9
PH
3281 }
3282
3283/* Sort out text for logging */
3284
3cc3f762
JH
3285log_msg = log_msg ? string_sprintf(": %s", log_msg) : US"";
3286if ((lognl = Ustrchr(log_msg, '\n'))) *lognl = 0;
059ec3d9
PH
3287
3288/* Send permanent failure response to the command, but the code used isn't
3289always a 5xx one - see comments at the start of this function. If the original
3290rc was FAIL_DROP we drop the connection and yield 2. */
3291
ff5929e3
JH
3292if (rc == FAIL)
3293 smtp_respond(smtp_code, codelen, TRUE,
3294 user_msg ? user_msg : US"Administrative prohibition");
059ec3d9
PH
3295
3296/* Send temporary failure response to the command. Don't give any details,
3297unless acl_temp_details is set. This is TRUE for a callout defer, a "defer"
3298verb, and for a header verify when smtp_return_error_details is set.
3299
3300This conditional logic is all somewhat of a mess because of the odd
3301interactions between temp_details and return_error_details. One day it should
3302be re-implemented in a tidier fashion. */
3303
3304else
ff5929e3 3305 if (acl_temp_details && user_msg)
059ec3d9 3306 {
ff5929e3
JH
3307 if ( smtp_return_error_details
3308 && sender_verified_failed
3309 && sender_verified_failed->message
3310 )
a5bd321b 3311 smtp_respond(smtp_code, codelen, FALSE, sender_verified_failed->message);
ff5929e3 3312
a5bd321b 3313 smtp_respond(smtp_code, codelen, TRUE, user_msg);
059ec3d9
PH
3314 }
3315 else
a5bd321b
PH
3316 smtp_respond(smtp_code, codelen, TRUE,
3317 US"Temporary local problem - please try later");
059ec3d9 3318
6ea85e9a
PH
3319/* Log the incident to the logs that are specified by log_reject_target
3320(default main, reject). This can be empty to suppress logging of rejections. If
3321the connection is not forcibly to be dropped, return 0. Otherwise, log why it
3322is closing if required and return 2. */
059ec3d9 3323
6ea85e9a 3324if (log_reject_target != 0)
887291d2 3325 {
e45a1c37 3326#ifdef SUPPORT_TLS
fc16abb4
JH
3327 uschar * tls = s_tlslog(NULL, NULL, NULL);
3328 if (!tls) tls = US"";
e45a1c37 3329#else
fc16abb4 3330 uschar * tls = US"";
e45a1c37 3331#endif
3cc3f762
JH
3332 log_write(where == ACL_WHERE_CONNECT ? L_connection_reject : 0,
3333 log_reject_target, "%s%s%s %s%srejected %s%s",
fc16abb4
JH
3334 LOGGING(dnssec) && sender_host_dnssec ? US" DS" : US"",
3335 host_and_ident(TRUE),
3336 tls,
3337 sender_info,
3338 rc == FAIL ? US"" : US"temporarily ",
3339 what, log_msg);
887291d2 3340 }
059ec3d9
PH
3341
3342if (!drop) return 0;
3343
3344log_write(L_smtp_connection, LOG_MAIN, "%s closed by DROP in ACL",
3345 smtp_get_connection_info());
8f128379
PH
3346
3347/* Run the not-quit ACL, but without any custom messages. This should not be a
3348problem, because we get here only if some other ACL has issued "drop", and
3349in that case, *its* custom messages will have been used above. */
3350
3351smtp_notquit_exit(US"acl-drop", NULL, NULL);
059ec3d9
PH
3352return 2;
3353}
3354
3355
3356
3357
8f128379
PH
3358/*************************************************
3359* Handle SMTP exit when QUIT is not given *
3360*************************************************/
3361
3362/* This function provides a logging/statistics hook for when an SMTP connection
3363is dropped on the floor or the other end goes away. It's a global function
3364because it's called from receive.c as well as this module. As well as running
3365the NOTQUIT ACL, if there is one, this function also outputs a final SMTP
3366response, either with a custom message from the ACL, or using a default. There
3367is one case, however, when no message is output - after "drop". In that case,
3368the ACL that obeyed "drop" has already supplied the custom message, and NULL is
3369passed to this function.
3370
3371In case things go wrong while processing this function, causing an error that
4c04137d 3372may re-enter this function, there is a recursion check.
8f128379
PH
3373
3374Arguments:
3375 reason What $smtp_notquit_reason will be set to in the ACL;
3376 if NULL, the ACL is not run
3377 code The error code to return as part of the response
3378 defaultrespond The default message if there's no user_msg
3379
3380Returns: Nothing
3381*/
3382
3383void
3384smtp_notquit_exit(uschar *reason, uschar *code, uschar *defaultrespond, ...)
3385{
3386int rc;
3387uschar *user_msg = NULL;
3388uschar *log_msg = NULL;
3389
3390/* Check for recursive acll */
3391
3392if (smtp_exit_function_called)
3393 {
3394 log_write(0, LOG_PANIC, "smtp_notquit_exit() called more than once (%s)",
3395 reason);
3396 return;
3397 }
3398smtp_exit_function_called = TRUE;
3399
3400/* Call the not-QUIT ACL, if there is one, unless no reason is given. */
3401
eea0defe 3402if (acl_smtp_notquit && reason)
8f128379
PH
3403 {
3404 smtp_notquit_reason = reason;
eea0defe
JB
3405 if ((rc = acl_check(ACL_WHERE_NOTQUIT, NULL, acl_smtp_notquit, &user_msg,
3406 &log_msg)) == ERROR)
8f128379
PH
3407 log_write(0, LOG_MAIN|LOG_PANIC, "ACL for not-QUIT returned ERROR: %s",
3408 log_msg);
3409 }
3410
3411/* Write an SMTP response if we are expected to give one. As the default
3412responses are all internal, they should always fit in the buffer, but code a
3413warning, just in case. Note that string_vformat() still leaves a complete
3414string, even if it is incomplete. */
3415
eea0defe 3416if (code && defaultrespond)
8f128379 3417 {
eea0defe
JB
3418 if (user_msg)
3419 smtp_respond(code, 3, TRUE, user_msg);
3420 else
8f128379
PH
3421 {
3422 uschar buffer[128];
3423 va_list ap;
3424 va_start(ap, defaultrespond);
3425 if (!string_vformat(buffer, sizeof(buffer), CS defaultrespond, ap))
3426 log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_notquit_exit()");
925ac8e4 3427 smtp_printf("%s %s\r\n", FALSE, code, buffer);
8f128379
PH
3428 va_end(ap);
3429 }
8f128379
PH
3430 mac_smtp_fflush();
3431 }
3432}
3433
3434
3435
3436
d7b47fd0
PH
3437/*************************************************
3438* Verify HELO argument *
3439*************************************************/
3440
3441/* This function is called if helo_verify_hosts or helo_try_verify_hosts is
3442matched. It is also called from ACL processing if verify = helo is used and
3443verification was not previously tried (i.e. helo_try_verify_hosts was not
3444matched). The result of its processing is to set helo_verified and
3445helo_verify_failed. These variables should both be FALSE for this function to
3446be called.
3447
3448Note that EHLO/HELO is legitimately allowed to quote an address literal. Allow
3449for IPv6 ::ffff: literals.
3450
3451Argument: none
3452Returns: TRUE if testing was completed;
3453 FALSE on a temporary failure
3454*/
3455
3456BOOL
3457smtp_verify_helo(void)
3458{
3459BOOL yield = TRUE;
3460
3461HDEBUG(D_receive) debug_printf("verifying EHLO/HELO argument \"%s\"\n",
3462 sender_helo_name);
3463
3464if (sender_helo_name == NULL)
3465 {
3466 HDEBUG(D_receive) debug_printf("no EHLO/HELO command was issued\n");
3467 }
3468
d1d5595c
PH
3469/* Deal with the case of -bs without an IP address */
3470
3471else if (sender_host_address == NULL)
3472 {
3473 HDEBUG(D_receive) debug_printf("no client IP address: assume success\n");
3474 helo_verified = TRUE;
3475 }
3476
3477/* Deal with the more common case when there is a sending IP address */
3478
d7b47fd0
PH
3479else if (sender_helo_name[0] == '[')
3480 {
3481 helo_verified = Ustrncmp(sender_helo_name+1, sender_host_address,
3482 Ustrlen(sender_host_address)) == 0;
3483
3484 #if HAVE_IPV6
3485 if (!helo_verified)
3486 {
3487 if (strncmpic(sender_host_address, US"::ffff:", 7) == 0)
3488 helo_verified = Ustrncmp(sender_helo_name + 1,
3489 sender_host_address + 7, Ustrlen(sender_host_address) - 7) == 0;
3490 }
3491 #endif
3492
3493 HDEBUG(D_receive)
3494 { if (helo_verified) debug_printf("matched host address\n"); }
3495 }
3496
3497/* Do a reverse lookup if one hasn't already given a positive or negative
3498response. If that fails, or the name doesn't match, try checking with a forward
3499lookup. */
3500
3501else
3502 {
3503 if (sender_host_name == NULL && !host_lookup_failed)
3504 yield = host_name_lookup() != DEFER;
3505
3506 /* If a host name is known, check it and all its aliases. */
3507
1705dd20
JH
3508 if (sender_host_name)
3509 if ((helo_verified = strcmpic(sender_host_name, sender_helo_name) == 0))
d7b47fd0 3510 {
1705dd20 3511 sender_helo_dnssec = sender_host_dnssec;
d7b47fd0
PH
3512 HDEBUG(D_receive) debug_printf("matched host name\n");
3513 }
3514 else
3515 {
3516 uschar **aliases = sender_host_aliases;
1705dd20
JH
3517 while (*aliases)
3518 if ((helo_verified = strcmpic(*aliases++, sender_helo_name) == 0))
3519 {
3520 sender_helo_dnssec = sender_host_dnssec;
3521 break;
3522 }
3523
3524 HDEBUG(D_receive) if (helo_verified)
d7b47fd0 3525 debug_printf("matched alias %s\n", *(--aliases));
d7b47fd0 3526 }
d7b47fd0
PH
3527
3528 /* Final attempt: try a forward lookup of the helo name */
3529
3530 if (!helo_verified)
3531 {
3532 int rc;
3533 host_item h;
1705dd20
JH
3534 dnssec_domains d;
3535 host_item *hh;
3536
d7b47fd0
PH
3537 h.name = sender_helo_name;
3538 h.address = NULL;
3539 h.mx = MX_NONE;
3540 h.next = NULL;
1705dd20
JH
3541 d.request = US"*";
3542 d.require = US"";
3543
d7b47fd0
PH
3544 HDEBUG(D_receive) debug_printf("getting IP address for %s\n",
3545 sender_helo_name);
1705dd20
JH
3546 rc = host_find_bydns(&h, NULL, HOST_FIND_BY_A,
3547 NULL, NULL, NULL, &d, NULL, NULL);
d7b47fd0 3548 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
1705dd20 3549 for (hh = &h; hh; hh = hh->next)
d7b47fd0
PH
3550 if (Ustrcmp(hh->address, sender_host_address) == 0)
3551 {
3552 helo_verified = TRUE;
1705dd20 3553 if (h.dnssec == DS_YES) sender_helo_dnssec = TRUE;
d7b47fd0 3554 HDEBUG(D_receive)
1705dd20
JH
3555 {
3556 debug_printf("IP address for %s matches calling address\n"
3557 "Forward DNS security status: %sverified\n",
3558 sender_helo_name, sender_helo_dnssec ? "" : "un");
3559 }
d7b47fd0
PH
3560 break;
3561 }
d7b47fd0
PH
3562 }
3563 }
3564
d1d5595c 3565if (!helo_verified) helo_verify_failed = TRUE; /* We've tried ... */
d7b47fd0
PH
3566return yield;
3567}
3568
3569
3570
3571
4e88a19f
PH
3572/*************************************************
3573* Send user response message *
3574*************************************************/
3575
3576/* This function is passed a default response code and a user message. It calls
3577smtp_message_code() to check and possibly modify the response code, and then
3578calls smtp_respond() to transmit the response. I put this into a function
3579just to avoid a lot of repetition.
3580
3581Arguments:
3582 code the response code
3583 user_msg the user message
3584
3585Returns: nothing
3586*/
3587
3588static void
3589smtp_user_msg(uschar *code, uschar *user_msg)
3590{
3591int len = 3;
4f6ae5c3 3592smtp_message_code(&code, &len, &user_msg, NULL, TRUE);
4e88a19f
PH
3593smtp_respond(code, len, TRUE, user_msg);
3594}
3595
3596
3597
b3ef41c9
JH
3598static int
3599smtp_in_auth(auth_instance *au, uschar ** s, uschar ** ss)
3600{
3601const uschar *set_id = NULL;
3602int rc, i;
3603
3604/* Run the checking code, passing the remainder of the command line as
3605data. Initials the $auth<n> variables as empty. Initialize $0 empty and set
3606it as the only set numerical variable. The authenticator may set $auth<n>
3607and also set other numeric variables. The $auth<n> variables are preferred
3608nowadays; the numerical variables remain for backwards compatibility.
3609
3610Afterwards, have a go at expanding the set_id string, even if
3611authentication failed - for bad passwords it can be useful to log the
3612userid. On success, require set_id to expand and exist, and put it in
3613authenticated_id. Save this in permanent store, as the working store gets
3614reset at HELO, RSET, etc. */
3615
3616for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL;
3617expand_nmax = 0;
3618expand_nlength[0] = 0; /* $0 contains nothing */
3619
3620rc = (au->info->servercode)(au, smtp_cmd_data);
3621if (au->set_id) set_id = expand_string(au->set_id);
3622expand_nmax = -1; /* Reset numeric variables */
3623for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL; /* Reset $auth<n> */
3624
3625/* The value of authenticated_id is stored in the spool file and printed in
3626log lines. It must not contain binary zeros or newline characters. In
3627normal use, it never will, but when playing around or testing, this error
3628can (did) happen. To guard against this, ensure that the id contains only
3629printing characters. */
3630
3631if (set_id) set_id = string_printing(set_id);
3632
3633/* For the non-OK cases, set up additional logging data if set_id
3634is not empty. */
3635
3636if (rc != OK)
3637 set_id = set_id && *set_id
3638 ? string_sprintf(" (set_id=%s)", set_id) : US"";
3639
3640/* Switch on the result */
3641
3642switch(rc)
3643 {
3644 case OK:
3645 if (!au->set_id || set_id) /* Complete success */
3646 {
3647 if (set_id) authenticated_id = string_copy_malloc(set_id);
3648 sender_host_authenticated = au->name;
3649 authentication_failed = FALSE;
3650 authenticated_fail_id = NULL; /* Impossible to already be set? */
3651
3652 received_protocol =
3653 (sender_host_address ? protocols : protocols_local)
3654 [pextend + pauthed + (tls_in.active >= 0 ? pcrpted:0)];
3655 *s = *ss = US"235 Authentication succeeded";
3656 authenticated_by = au;
3657 break;
3658 }
3659
3660 /* Authentication succeeded, but we failed to expand the set_id string.
3661 Treat this as a temporary error. */
3662
3663 auth_defer_msg = expand_string_message;
3664 /* Fall through */
3665
3666 case DEFER:
3667 if (set_id) authenticated_fail_id = string_copy_malloc(set_id);
3668 *s = string_sprintf("435 Unable to authenticate at present%s",
3669 auth_defer_user_msg);
3670 *ss = string_sprintf("435 Unable to authenticate at present%s: %s",
3671 set_id, auth_defer_msg);
3672 break;
3673
3674 case BAD64:
3675 *s = *ss = US"501 Invalid base64 data";
3676 break;
3677
3678 case CANCELLED:
3679 *s = *ss = US"501 Authentication cancelled";
3680 break;
3681
3682 case UNEXPECTED:
3683 *s = *ss = US"553 Initial data not expected";
3684 break;
3685
3686 case FAIL:
3687 if (set_id) authenticated_fail_id = string_copy_malloc(set_id);
3688 *s = US"535 Incorrect authentication data";
3689 *ss = string_sprintf("535 Incorrect authentication data%s", set_id);
3690 break;
3691
3692 default:
3693 if (set_id) authenticated_fail_id = string_copy_malloc(set_id);
3694 *s = US"435 Internal error";
3695 *ss = string_sprintf("435 Internal error%s: return %d from authentication "
3696 "check", set_id, rc);
3697 break;
3698 }
3699
3700return rc;
3701}
3702
3703
3704
2685d6e0
JH
3705
3706
3707static int
3708qualify_recipient(uschar ** recipient, uschar * smtp_cmd_data, uschar * tag)
3709{
3710int rd;
3711if (allow_unqualified_recipient || strcmpic(*recipient, US"postmaster") == 0)
3712 {
3713 DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
3714 *recipient);
3715 rd = Ustrlen(recipient) + 1;
3716 *recipient = rewrite_address_qualify(*recipient, TRUE);
3717 return rd;
3718 }
925ac8e4 3719smtp_printf("501 %s: recipient address must contain a domain\r\n", FALSE,
2685d6e0
JH
3720 smtp_cmd_data);
3721log_write(L_smtp_syntax_error,
3722 LOG_MAIN|LOG_REJECT, "unqualified %s rejected: <%s> %s%s",
3723 tag, *recipient, host_and_ident(TRUE), host_lookup_msg);
3724return 0;
3725}
3726
3727
3728
3729
7e3ce68e
JH
3730static void
3731smtp_quit_handler(uschar ** user_msgp, uschar ** log_msgp)
3732{
3733HAD(SCH_QUIT);
3734incomplete_transaction_log(US"QUIT");
60d10ce7 3735if (acl_smtp_quit)
7e3ce68e
JH
3736 {
3737 int rc = acl_check(ACL_WHERE_QUIT, NULL, acl_smtp_quit, user_msgp, log_msgp);
3738 if (rc == ERROR)
3739 log_write(0, LOG_MAIN|LOG_PANIC, "ACL for QUIT returned ERROR: %s",
3740 *log_msgp);
3741 }
3742if (*user_msgp)
3743 smtp_respond(US"221", 3, TRUE, *user_msgp);
3744else
925ac8e4 3745 smtp_printf("221 %s closing connection\r\n", FALSE, smtp_active_hostname);
7e3ce68e
JH
3746
3747#ifdef SUPPORT_TLS
3748tls_close(TRUE, TRUE);
3749#endif
3750
3751log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT",
3752 smtp_get_connection_info());
3753}
3754
3755
3756static void
3757smtp_rset_handler(void)
3758{
3759HAD(SCH_RSET);
3760incomplete_transaction_log(US"RSET");
925ac8e4 3761smtp_printf("250 Reset OK\r\n", FALSE);
7e3ce68e
JH
3762cmd_list[CMD_LIST_RSET].is_mail_cmd = FALSE;
3763}
3764
3765
3766
059ec3d9
PH
3767/*************************************************
3768* Initialize for SMTP incoming message *
3769*************************************************/
3770
3771/* This function conducts the initial dialogue at the start of an incoming SMTP
3772message, and builds a list of recipients. However, if the incoming message
3773is part of a batch (-bS option) a separate function is called since it would
3774be messy having tests splattered about all over this function. This function
3775therefore handles the case where interaction is occurring. The input and output
3776files are set up in smtp_in and smtp_out.
3777
3778The global recipients_list is set to point to a vector of recipient_item
3779blocks, whose number is given by recipients_count. This is extended by the
3780receive_add_recipient() function. The global variable sender_address is set to
3781the sender's address. The yield is +1 if a message has been successfully
3782started, 0 if a QUIT command was encountered or the connection was refused from
3783the particular host, or -1 if the connection was lost.
3784
3785Argument: none
3786
3787Returns: > 0 message successfully started (reached DATA)
3788 = 0 QUIT read or end of file reached or call refused
3789 < 0 lost connection
3790*/
3791
3792int
3793smtp_setup_msg(void)
3794{
3795int done = 0;
3796BOOL toomany = FALSE;
3797BOOL discarded = FALSE;
3798BOOL last_was_rej_mail = FALSE;
3799BOOL last_was_rcpt = FALSE;
3800void *reset_point = store_get(0);
3801
3802DEBUG(D_receive) debug_printf("smtp_setup_msg entered\n");
3803
3804/* Reset for start of new message. We allow one RSET not to be counted as a
3805nonmail command, for those MTAs that insist on sending it between every
3806message. Ditto for EHLO/HELO and for STARTTLS, to allow for going in and out of
3807TLS between messages (an Exim client may do this if it has messages queued up
3808for the host). Note: we do NOT reset AUTH at this point. */
3809
3810smtp_reset(reset_point);
3811message_ended = END_NOTSTARTED;
3812
7e3ce68e
JH
3813chunking_state = chunking_offered ? CHUNKING_OFFERED : CHUNKING_NOT_OFFERED;
3814
059ec3d9
PH
3815cmd_list[CMD_LIST_RSET].is_mail_cmd = TRUE;
3816cmd_list[CMD_LIST_HELO].is_mail_cmd = TRUE;
3817cmd_list[CMD_LIST_EHLO].is_mail_cmd = TRUE;
3818#ifdef SUPPORT_TLS
3819cmd_list[CMD_LIST_STARTTLS].is_mail_cmd = TRUE;
b3ef41c9 3820cmd_list[CMD_LIST_TLS_AUTH].is_mail_cmd = TRUE;
059ec3d9
PH
3821#endif
3822
3823/* Set the local signal handler for SIGTERM - it tries to end off tidily */
3824
3825os_non_restarting_signal(SIGTERM, command_sigterm_handler);
3826
3827/* Batched SMTP is handled in a different function. */
3828
3829if (smtp_batched_input) return smtp_setup_batch_msg();
3830
3831/* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
3832value. The values are 2 larger than the required yield of the function. */
3833
3834while (done <= 0)
3835 {
55414b25 3836 const uschar **argv;
059ec3d9
PH
3837 uschar *etrn_command;
3838 uschar *etrn_serialize_key;
3839 uschar *errmess;
4e88a19f
PH
3840 uschar *log_msg, *smtp_code;
3841 uschar *user_msg = NULL;
059ec3d9
PH
3842 uschar *recipient = NULL;
3843 uschar *hello = NULL;
059ec3d9
PH
3844 uschar *s, *ss;
3845 BOOL was_rej_mail = FALSE;
3846 BOOL was_rcpt = FALSE;
3847 void (*oldsignal)(int);
3848 pid_t pid;
3849 int start, end, sender_domain, recipient_domain;
3850 int ptr, size, rc;
aa7751be 3851 int c;
059ec3d9 3852 auth_instance *au;
6c1c3d1d
WB
3853 uschar *orcpt = NULL;
3854 int flags;
059ec3d9 3855
16be7f11 3856#ifdef AUTH_TLS
b3ef41c9
JH
3857 /* Check once per STARTTLS or SSL-on-connect for a TLS AUTH */
3858 if ( tls_in.active >= 0
3859 && tls_in.peercert
3860 && tls_in.certificate_verified
3861 && cmd_list[CMD_LIST_TLS_AUTH].is_mail_cmd
3862 )
3863 {
3864 cmd_list[CMD_LIST_TLS_AUTH].is_mail_cmd = FALSE;
4f6ae5c3
JH
3865 if ( acl_smtp_auth
3866 && (rc = acl_check(ACL_WHERE_AUTH, NULL, acl_smtp_auth,
3867 &user_msg, &log_msg)) != OK
3868 )
b3ef41c9 3869 {
4f6ae5c3
JH
3870 done = smtp_handle_acl_fail(ACL_WHERE_AUTH, rc, user_msg, log_msg);
3871 continue;
b3ef41c9
JH
3872 }
3873
3874 for (au = auths; au; au = au->next)
3875 if (strcmpic(US"tls", au->driver_name) == 0)
3876 {
3877 smtp_cmd_data = NULL;
3878
805bb5c3 3879 if (smtp_in_auth(au, &s, &ss) == OK)
cb570b5e 3880 { DEBUG(D_auth) debug_printf("tls auth succeeded\n"); }
805bb5c3 3881 else
cb570b5e 3882 { DEBUG(D_auth) debug_printf("tls auth not succeeded\n"); }
b3ef41c9
JH
3883 break;
3884 }
3885 }
3886#endif
3887
8d330698
JH
3888#ifdef TCP_QUICKACK
3889 if (smtp_in) /* Avoid pure-ACKs while in cmd pingpong phase */
3890 (void) setsockopt(fileno(smtp_in), IPPROTO_TCP, TCP_QUICKACK,
3891 US &off, sizeof(off));
3892#endif
3893
bd8fbe36 3894 switch(smtp_read_command(TRUE, GETC_BUFFER_UNLIMITED))
059ec3d9
PH
3895 {
3896 /* The AUTH command is not permitted to occur inside a transaction, and may
c46782ef
PH
3897 occur successfully only once per connection. Actually, that isn't quite
3898 true. When TLS is started, all previous information about a connection must
3899 be discarded, so a new AUTH is permitted at that time.
3900
3901 AUTH may only be used when it has been advertised. However, it seems that
3902 there are clients that send AUTH when it hasn't been advertised, some of
3903 them even doing this after HELO. And there are MTAs that accept this. Sigh.
3904 So there's a get-out that allows this to happen.
059ec3d9
PH
3905
3906 AUTH is initially labelled as a "nonmail command" so that one occurrence
3907 doesn't get counted. We change the label here so that multiple failing
3908 AUTHS will eventually hit the nonmail threshold. */
3909
3910 case AUTH_CMD:
b4ed4da0 3911 HAD(SCH_AUTH);
059ec3d9
PH
3912 authentication_failed = TRUE;
3913 cmd_list[CMD_LIST_AUTH].is_mail_cmd = FALSE;
3914
c46782ef 3915 if (!auth_advertised && !allow_auth_unadvertised)
059ec3d9
PH
3916 {
3917 done = synprot_error(L_smtp_protocol_error, 503, NULL,
3918 US"AUTH command used when not advertised");
3919 break;
3920 }
b3ef41c9 3921 if (sender_host_authenticated)
059ec3d9
PH
3922 {
3923 done = synprot_error(L_smtp_protocol_error, 503, NULL,
3924 US"already authenticated");
3925 break;
3926 }
b3ef41c9 3927 if (sender_address)
059ec3d9
PH
3928 {
3929 done = synprot_error(L_smtp_protocol_error, 503, NULL,
3930 US"not permitted in mail transaction");
3931 break;
3932 }
3933
3934 /* Check the ACL */
3935
4f6ae5c3
JH
3936 if ( acl_smtp_auth
3937 && (rc = acl_check(ACL_WHERE_AUTH, NULL, acl_smtp_auth,
3938 &user_msg, &log_msg)) != OK
3939 )
059ec3d9 3940 {
4f6ae5c3
JH
3941 done = smtp_handle_acl_fail(ACL_WHERE_AUTH, rc, user_msg, log_msg);
3942 break;
059ec3d9
PH
3943 }
3944
3945 /* Find the name of the requested authentication mechanism. */
3946
ca86f471
PH
3947 s = smtp_cmd_data;
3948 while ((c = *smtp_cmd_data) != 0 && !isspace(c))
059ec3d9
PH
3949 {
3950 if (!isalnum(c) && c != '-' && c != '_')
3951 {
3952 done = synprot_error(L_smtp_syntax_error, 501, NULL,
3953 US"invalid character in authentication mechanism name");
3954 goto COMMAND_LOOP;
3955 }
ca86f471 3956 smtp_cmd_data++;
059ec3d9
PH
3957 }
3958
3959 /* If not at the end of the line, we must be at white space. Terminate the
3960 name and move the pointer on to any data that may be present. */
3961
ca86f471 3962 if (*smtp_cmd_data != 0)
059ec3d9 3963 {
ca86f471
PH
3964 *smtp_cmd_data++ = 0;
3965 while (isspace(*smtp_cmd_data)) smtp_cmd_data++;
059ec3d9
PH
3966 }
3967
3968 /* Search for an authentication mechanism which is configured for use
c46782ef
PH
3969 as a server and which has been advertised (unless, sigh, allow_auth_
3970 unadvertised is set). */
059ec3d9 3971
b3ef41c9 3972 for (au = auths; au; au = au->next)
059ec3d9 3973 if (strcmpic(s, au->public_name) == 0 && au->server &&
b3ef41c9
JH
3974 (au->advertised || allow_auth_unadvertised))
3975 break;
059ec3d9 3976
b3ef41c9 3977 if (au)
059ec3d9 3978 {
b3ef41c9 3979 c = smtp_in_auth(au, &s, &ss);
059ec3d9 3980
925ac8e4 3981 smtp_printf("%s\r\n", FALSE, s);
b3ef41c9
JH
3982 if (c != OK)
3983 log_write(0, LOG_MAIN|LOG_REJECT, "%s authenticator failed for %s: %s",
3984 au->name, host_and_ident(FALSE), ss);
059ec3d9 3985 }
b3ef41c9
JH
3986 else
3987 done = synprot_error(L_smtp_protocol_error, 504, NULL,
3988 string_sprintf("%s authentication mechanism not supported", s));
059ec3d9
PH
3989
3990 break; /* AUTH_CMD */
3991
3992 /* The HELO/EHLO commands are permitted to appear in the middle of a
3993 session as well as at the beginning. They have the effect of a reset in
3994 addition to their other functions. Their absence at the start cannot be
3995 taken to be an error.
3996
3997 RFC 2821 says:
3998
3999 If the EHLO command is not acceptable to the SMTP server, 501, 500,
4000 or 502 failure replies MUST be returned as appropriate. The SMTP
4001 server MUST stay in the same state after transmitting these replies
4002 that it was in before the EHLO was received.
4003
4004 Therefore, we do not do the reset until after checking the command for
4005 acceptability. This change was made for Exim release 4.11. Previously
4006 it did the reset first. */
4007
4008 case HELO_CMD:
b4ed4da0 4009 HAD(SCH_HELO);
059ec3d9
PH
4010 hello = US"HELO";
4011 esmtp = FALSE;
4012 goto HELO_EHLO;
4013
4014 case EHLO_CMD:
b4ed4da0 4015 HAD(SCH_EHLO);
059ec3d9
PH
4016 hello = US"EHLO";
4017 esmtp = TRUE;
4018
4019 HELO_EHLO: /* Common code for HELO and EHLO */
4020 cmd_list[CMD_LIST_HELO].is_mail_cmd = FALSE;
4021 cmd_list[CMD_LIST_EHLO].is_mail_cmd = FALSE;
4022
4023 /* Reject the HELO if its argument was invalid or non-existent. A
4024 successful check causes the argument to be saved in malloc store. */
4025
ca86f471 4026 if (!check_helo(smtp_cmd_data))
059ec3d9 4027 {
925ac8e4 4028 smtp_printf("501 Syntactically invalid %s argument(s)\r\n", FALSE, hello);
059ec3d9
PH
4029
4030 log_write(0, LOG_MAIN|LOG_REJECT, "rejected %s from %s: syntactically "
4031 "invalid argument(s): %s", hello, host_and_ident(FALSE),
3ee512ff
PH
4032 (*smtp_cmd_argument == 0)? US"(no argument given)" :
4033 string_printing(smtp_cmd_argument));
059ec3d9
PH
4034
4035 if (++synprot_error_count > smtp_max_synprot_errors)
4036 {
4037 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
4038 "syntax or protocol errors (last command was \"%s\")",
0ebc4d69 4039 host_and_ident(FALSE), string_printing(smtp_cmd_buffer));
059ec3d9
PH
4040 done = 1;
4041 }
4042
4043 break;
4044 }
4045
4046 /* If sender_host_unknown is true, we have got here via the -bs interface,
4047 not called from inetd. Otherwise, we are running an IP connection and the
4048 host address will be set. If the helo name is the primary name of this
4049 host and we haven't done a reverse lookup, force one now. If helo_required
4050 is set, ensure that the HELO name matches the actual host. If helo_verify
4051 is set, do the same check, but softly. */
4052
4053 if (!sender_host_unknown)
4054 {
4055 BOOL old_helo_verified = helo_verified;
ca86f471 4056 uschar *p = smtp_cmd_data;
059ec3d9
PH
4057
4058 while (*p != 0 && !isspace(*p)) { *p = tolower(*p); p++; }
4059 *p = 0;
4060
4061 /* Force a reverse lookup if HELO quoted something in helo_lookup_domains
4062 because otherwise the log can be confusing. */
4063
4064 if (sender_host_name == NULL &&
4065 (deliver_domain = sender_helo_name, /* set $domain */
55414b25 4066 match_isinlist(sender_helo_name, CUSS &helo_lookup_domains, 0,
059ec3d9
PH
4067 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL)) == OK)
4068 (void)host_name_lookup();
4069
4070 /* Rebuild the fullhost info to include the HELO name (and the real name
4071 if it was looked up.) */
4072
4073 host_build_sender_fullhost(); /* Rebuild */
4074 set_process_info("handling%s incoming connection from %s",
817d9f57 4075 (tls_in.active >= 0)? " TLS" : "", host_and_ident(FALSE));
059ec3d9
PH
4076
4077 /* Verify if configured. This doesn't give much security, but it does
d7b47fd0
PH
4078 make some people happy to be able to do it. If helo_required is set,
4079 (host matches helo_verify_hosts) failure forces rejection. If helo_verify
4080 is set (host matches helo_try_verify_hosts), it does not. This is perhaps
4081 now obsolescent, since the verification can now be requested selectively
4082 at ACL time. */
059ec3d9 4083
1705dd20 4084 helo_verified = helo_verify_failed = sender_helo_dnssec = FALSE;
059ec3d9
PH
4085 if (helo_required || helo_verify)
4086 {
d7b47fd0 4087 BOOL tempfail = !smtp_verify_helo();
059ec3d9
PH
4088 if (!helo_verified)
4089 {
4090 if (helo_required)
4091 {
925ac8e4 4092 smtp_printf("%d %s argument does not match calling host\r\n", FALSE,
059ec3d9
PH
4093 tempfail? 451 : 550, hello);
4094 log_write(0, LOG_MAIN|LOG_REJECT, "%srejected \"%s %s\" from %s",
4095 tempfail? "temporarily " : "",
4096 hello, sender_helo_name, host_and_ident(FALSE));
4097 helo_verified = old_helo_verified;
4098 break; /* End of HELO/EHLO processing */
4099 }
4100 HDEBUG(D_all) debug_printf("%s verification failed but host is in "
4101 "helo_try_verify_hosts\n", hello);
4102 }
4103 }
4104 }
4105
8523533c
TK
4106#ifdef EXPERIMENTAL_SPF
4107 /* set up SPF context */
4108 spf_init(sender_helo_name, sender_host_address);
4109#endif
4110
a14e5636
PH
4111 /* Apply an ACL check if one is defined; afterwards, recheck
4112 synchronization in case the client started sending in a delay. */
059ec3d9 4113
4f6ae5c3
JH
4114 if (acl_smtp_helo)
4115 if ((rc = acl_check(ACL_WHERE_HELO, NULL, acl_smtp_helo,
4116 &user_msg, &log_msg)) != OK)
059ec3d9
PH
4117 {
4118 done = smtp_handle_acl_fail(ACL_WHERE_HELO, rc, user_msg, log_msg);
4119 sender_helo_name = NULL;
4120 host_build_sender_fullhost(); /* Rebuild */
4121 break;
4122 }
a14e5636 4123 else if (!check_sync()) goto SYNC_FAILURE;
059ec3d9 4124
4e88a19f
PH
4125 /* Generate an OK reply. The default string includes the ident if present,
4126 and also the IP address if present. Reflecting back the ident is intended
4127 as a deterrent to mail forgers. For maximum efficiency, and also because
4128 some broken systems expect each response to be in a single packet, arrange
4129 that the entire reply is sent in one write(). */
059ec3d9
PH
4130
4131 auth_advertised = FALSE;
4132 pipelining_advertised = FALSE;
d1a13eea 4133#ifdef SUPPORT_TLS
059ec3d9 4134 tls_advertised = FALSE;
d1a13eea 4135#endif
6c1c3d1d 4136 dsn_advertised = FALSE;
8c5d388a 4137#ifdef SUPPORT_I18N
d1a13eea
JH
4138 smtputf8_advertised = FALSE;
4139#endif
059ec3d9 4140
d6a96edc 4141 smtp_code = US"250 "; /* Default response code plus space*/
00580051 4142 if (!user_msg)
4e88a19f
PH
4143 {
4144 s = string_sprintf("%.3s %s Hello %s%s%s",
4145 smtp_code,
4146 smtp_active_hostname,
00580051
JH
4147 sender_ident ? sender_ident : US"",
4148 sender_ident ? US" at " : US"",
4149 sender_host_name ? sender_host_name : sender_helo_name);
4e88a19f
PH
4150
4151 ptr = Ustrlen(s);
4152 size = ptr + 1;
059ec3d9 4153
00580051 4154 if (sender_host_address)
4e88a19f 4155 {
c2f669a4
JH
4156 s = string_catn(s, &size, &ptr, US" [", 2);
4157 s = string_cat (s, &size, &ptr, sender_host_address);
4158 s = string_catn(s, &size, &ptr, US"]", 1);
4e88a19f
PH
4159 }
4160 }
4161
d6a96edc
PH
4162 /* A user-supplied EHLO greeting may not contain more than one line. Note
4163 that the code returned by smtp_message_code() includes the terminating
4164 whitespace character. */
059ec3d9 4165
4e88a19f 4166 else
059ec3d9 4167 {
4e88a19f 4168 char *ss;
d6a96edc 4169 int codelen = 4;
4f6ae5c3 4170 smtp_message_code(&smtp_code, &codelen, &user_msg, NULL, TRUE);
d6a96edc 4171 s = string_sprintf("%.*s%s", codelen, smtp_code, user_msg);
4e88a19f
PH
4172 if ((ss = strpbrk(CS s, "\r\n")) != NULL)
4173 {
4174 log_write(0, LOG_MAIN|LOG_PANIC, "EHLO/HELO response must not contain "
4175 "newlines: message truncated: %s", string_printing(s));
4176 *ss = 0;
4177 }
4178 ptr = Ustrlen(s);
4179 size = ptr + 1;
059ec3d9
PH
4180 }
4181
c2f669a4 4182 s = string_catn(s, &size, &ptr, US"\r\n", 2);
059ec3d9
PH
4183
4184 /* If we received EHLO, we must create a multiline response which includes
4185 the functions supported. */
4186
4187 if (esmtp)
4188 {
4189 s[3] = '-';
4190
4191 /* I'm not entirely happy with this, as an MTA is supposed to check
4192 that it has enough room to accept a message of maximum size before
4193 it sends this. However, there seems little point in not sending it.
4194 The actual size check happens later at MAIL FROM time. By postponing it
4195 till then, VRFY and EXPN can be used after EHLO when space is short. */
4196
4197 if (thismessage_size_limit > 0)
4198 {
4e88a19f
PH
4199 sprintf(CS big_buffer, "%.3s-SIZE %d\r\n", smtp_code,
4200 thismessage_size_limit);
c2f669a4 4201 s = string_cat(s, &size, &ptr, big_buffer);
059ec3d9
PH
4202 }
4203 else
4204 {
c2f669a4
JH
4205 s = string_catn(s, &size, &ptr, smtp_code, 3);
4206 s = string_catn(s, &size, &ptr, US"-SIZE\r\n", 7);
059ec3d9
PH
4207 }
4208
4209 /* Exim does not do protocol conversion or data conversion. It is 8-bit
4210 clean; if it has an 8-bit character in its hand, it just sends it. It
4211 cannot therefore specify 8BITMIME and remain consistent with the RFCs.
4212 However, some users want this option simply in order to stop MUAs
4213 mangling messages that contain top-bit-set characters. It is therefore
4214 provided as an option. */
4215
4216 if (accept_8bitmime)
4e88a19f 4217 {
c2f669a4
JH
4218 s = string_catn(s, &size, &ptr, smtp_code, 3);
4219 s = string_catn(s, &size, &ptr, US"-8BITMIME\r\n", 11);
4e88a19f 4220 }
059ec3d9 4221
6c1c3d1d 4222 /* Advertise DSN support if configured to do so. */
94431adb 4223 if (verify_check_host(&dsn_advertise_hosts) != FAIL)
6c1c3d1d 4224 {
c2f669a4
JH
4225 s = string_catn(s, &size, &ptr, smtp_code, 3);
4226 s = string_catn(s, &size, &ptr, US"-DSN\r\n", 6);
6c1c3d1d
WB
4227 dsn_advertised = TRUE;
4228 }
6c1c3d1d 4229
bbc8ed07
JH
4230 /* Advertise ETRN/VRFY/EXPN if there's are ACL checking whether a host is
4231 permitted to issue them; a check is made when any host actually tries. */
059ec3d9 4232
bbc8ed07 4233 if (acl_smtp_etrn)
059ec3d9 4234 {
c2f669a4
JH
4235 s = string_catn(s, &size, &ptr, smtp_code, 3);
4236 s = string_catn(s, &size, &ptr, US"-ETRN\r\n", 7);
059ec3d9 4237 }
bbc8ed07
JH
4238 if (acl_smtp_vrfy)
4239 {
4240 s = string_catn(s, &size, &ptr, smtp_code, 3);
4241 s = string_catn(s, &size, &ptr, US"-VRFY\r\n", 7);
4242 }
4243 if (acl_smtp_expn)
059ec3d9 4244 {
c2f669a4
JH
4245 s = string_catn(s, &size, &ptr, smtp_code, 3);
4246 s = string_catn(s, &size, &ptr, US"-EXPN\r\n", 7);
059ec3d9
PH
4247 }
4248
4249 /* Exim is quite happy with pipelining, so let the other end know that
4250 it is safe to use it, unless advertising is disabled. */
4251
cf8b11a5
PH
4252 if (pipelining_enable &&
4253 verify_check_host(&pipelining_advertise_hosts) == OK)
059ec3d9 4254 {
c2f669a4
JH
4255 s = string_catn(s, &size, &ptr, smtp_code, 3);
4256 s = string_catn(s, &size, &ptr, US"-PIPELINING\r\n", 13);
059ec3d9
PH
4257 sync_cmd_limit = NON_SYNC_CMD_PIPELINING;
4258 pipelining_advertised = TRUE;
4259 }
4260
fd98a5c6 4261
059ec3d9
PH
4262 /* If any server authentication mechanisms are configured, advertise
4263 them if the current host is in auth_advertise_hosts. The problem with
4264 advertising always is that some clients then require users to
4265 authenticate (and aren't configurable otherwise) even though it may not
4266 be necessary (e.g. if the host is in host_accept_relay).
4267
4268 RFC 2222 states that SASL mechanism names contain only upper case
4269 letters, so output the names in upper case, though we actually recognize
4270 them in either case in the AUTH command. */
4271
b3ef41c9 4272 if ( auths
16be7f11 4273#ifdef AUTH_TLS
b3ef41c9
JH
4274 && !sender_host_authenticated
4275#endif
4276 && verify_check_host(&auth_advertise_hosts) == OK
4277 )
4278 {
4279 auth_instance *au;
4280 BOOL first = TRUE;
4281 for (au = auths; au; au = au->next)
8b6b06fe
JH
4282 {
4283 au->advertised = FALSE;
4284 if (au->server)
b3ef41c9 4285 {
8b6b06fe
JH
4286 DEBUG(D_auth+D_expand) debug_printf_indent(
4287 "Evaluating advertise_condition for %s athenticator\n",
4288 au->public_name);
4289 if ( !au->advertise_condition
4290 || expand_check_condition(au->advertise_condition, au->name,
4291 US"authenticator")
4292 )
b3ef41c9 4293 {
8b6b06fe
JH
4294 int saveptr;
4295 if (first)
4296 {
4297 s = string_catn(s, &size, &ptr, smtp_code, 3);
4298 s = string_catn(s, &size, &ptr, US"-AUTH", 5);
4299 first = FALSE;
4300 auth_advertised = TRUE;
4301 }
4302 saveptr = ptr;
4303 s = string_catn(s, &size, &ptr, US" ", 1);
4304 s = string_cat (s, &size, &ptr, au->public_name);
4305 while (++saveptr < ptr) s[saveptr] = toupper(s[saveptr]);
4306 au->advertised = TRUE;
b3ef41c9 4307 }
b3ef41c9 4308 }
8b6b06fe 4309 }
b3ef41c9 4310
c2f669a4 4311 if (!first) s = string_catn(s, &size, &ptr, US"\r\n", 2);
b3ef41c9 4312 }
059ec3d9 4313
18481de3 4314 /* RFC 3030 CHUNKING */
059ec3d9 4315
aa368db3
JH
4316 if (verify_check_host(&chunking_advertise_hosts) != FAIL)
4317 {
4318 s = string_catn(s, &size, &ptr, smtp_code, 3);
4319 s = string_catn(s, &size, &ptr, US"-CHUNKING\r\n", 11);
7e3ce68e 4320 chunking_offered = TRUE;
18481de3 4321 chunking_state = CHUNKING_OFFERED;
aa368db3
JH
4322 }
4323
18481de3
JH
4324 /* Advertise TLS (Transport Level Security) aka SSL (Secure Socket Layer)
4325 if it has been included in the binary, and the host matches
4326 tls_advertise_hosts. We must *not* advertise if we are already in a
4327 secure connection. */
4328
d1a13eea 4329#ifdef SUPPORT_TLS
817d9f57 4330 if (tls_in.active < 0 &&
059ec3d9
PH
4331 verify_check_host(&tls_advertise_hosts) != FAIL)
4332 {
c2f669a4
JH
4333 s = string_catn(s, &size, &ptr, smtp_code, 3);
4334 s = string_catn(s, &size, &ptr, US"-STARTTLS\r\n", 11);
059ec3d9
PH
4335 tls_advertised = TRUE;
4336 }
d1a13eea 4337#endif
059ec3d9 4338
d1a13eea 4339#ifndef DISABLE_PRDR
fd98a5c6 4340 /* Per Recipient Data Response, draft by Eric A. Hall extending RFC */
8ccd00b1
JH
4341 if (prdr_enable)
4342 {
c2f669a4
JH
4343 s = string_catn(s, &size, &ptr, smtp_code, 3);
4344 s = string_catn(s, &size, &ptr, US"-PRDR\r\n", 7);
8ccd00b1 4345 }
d1a13eea
JH
4346#endif
4347
8c5d388a 4348#ifdef SUPPORT_I18N
d1a13eea
JH
4349 if ( accept_8bitmime
4350 && verify_check_host(&smtputf8_advertise_hosts) != FAIL)
4351 {
c2f669a4
JH
4352 s = string_catn(s, &size, &ptr, smtp_code, 3);
4353 s = string_catn(s, &size, &ptr, US"-SMTPUTF8\r\n", 11);
d1a13eea
JH
4354 smtputf8_advertised = TRUE;
4355 }
4356#endif
fd98a5c6 4357
059ec3d9
PH
4358 /* Finish off the multiline reply with one that is always available. */
4359
c2f669a4
JH
4360 s = string_catn(s, &size, &ptr, smtp_code, 3);
4361 s = string_catn(s, &size, &ptr, US" HELP\r\n", 7);
059ec3d9
PH
4362 }
4363
4364 /* Terminate the string (for debug), write it, and note that HELO/EHLO
4365 has been seen. */
4366
4367 s[ptr] = 0;
4368
d1a13eea 4369#ifdef SUPPORT_TLS
925ac8e4 4370 if (tls_in.active >= 0) (void)tls_write(TRUE, s, ptr, FALSE); else
d1a13eea 4371#endif
059ec3d9 4372
1ac6b2e7
JH
4373 {
4374 int i = fwrite(s, 1, ptr, smtp_out); i = i; /* compiler quietening */
4375 }
898d150f
PH
4376 DEBUG(D_receive)
4377 {
4378 uschar *cr;
4379 while ((cr = Ustrchr(s, '\r')) != NULL) /* lose CRs */
4380 memmove(cr, cr + 1, (ptr--) - (cr - s));
4381 debug_printf("SMTP>> %s", s);
4382 }
059ec3d9 4383 helo_seen = TRUE;
4e88a19f
PH
4384
4385 /* Reset the protocol and the state, abandoning any previous message. */
e524074d
JH
4386 received_protocol =
4387 (sender_host_address ? protocols : protocols_local)
4388 [ (esmtp
4389 ? pextend + (sender_host_authenticated ? pauthed : 0)
4390 : pnormal)
4391 + (tls_in.active >= 0 ? pcrpted : 0)
4392 ];
57cc2785 4393 cancel_cutthrough_connection(TRUE, US"sent EHLO response");
4e88a19f
PH
4394 smtp_reset(reset_point);
4395 toomany = FALSE;
059ec3d9
PH
4396 break; /* HELO/EHLO */
4397
4398
4399 /* The MAIL command requires an address as an operand. All we do
4400 here is to parse it for syntactic correctness. The form "<>" is
4401 a special case which converts into an empty string. The start/end
4402 pointers in the original are not used further for this address, as
4403 it is the canonical extracted address which is all that is kept. */
4404
4405 case MAIL_CMD:
b4ed4da0 4406 HAD(SCH_MAIL);
059ec3d9
PH
4407 smtp_mailcmd_count++; /* Count for limit and ratelimit */
4408 was_rej_mail = TRUE; /* Reset if accepted */
d27f98fe 4409 env_mail_type_t * mail_args; /* Sanity check & validate args */
059ec3d9
PH
4410
4411 if (helo_required && !helo_seen)
4412 {
925ac8e4 4413 smtp_printf("503 HELO or EHLO required\r\n", FALSE);
059ec3d9
PH
4414 log_write(0, LOG_MAIN|LOG_REJECT, "rejected MAIL from %s: no "
4415 "HELO/EHLO given", host_and_ident(FALSE));
4416 break;
4417 }
4418
4419 if (sender_address != NULL)
4420 {
4421 done = synprot_error(L_smtp_protocol_error, 503, NULL,
4422 US"sender already given");
4423 break;
4424 }
4425
ca86f471 4426 if (smtp_cmd_data[0] == 0)
059ec3d9
PH
4427 {
4428 done = synprot_error(L_smtp_protocol_error, 501, NULL,
4429 US"MAIL must have an address operand");
4430 break;
4431 }
4432
4433 /* Check to see if the limit for messages per connection would be
4434 exceeded by accepting further messages. */
4435
4436 if (smtp_accept_max_per_connection > 0 &&
4437 smtp_mailcmd_count > smtp_accept_max_per_connection)
4438 {
925ac8e4 4439 smtp_printf("421 too many messages in this connection\r\n", FALSE);
059ec3d9
PH
4440 log_write(0, LOG_MAIN|LOG_REJECT, "rejected MAIL command %s: too many "
4441 "messages in one connection", host_and_ident(TRUE));
4442 break;
4443 }
4444
4445 /* Reset for start of message - even if this is going to fail, we
4446 obviously need to throw away any previous data. */
4447
57cc2785 4448 cancel_cutthrough_connection(TRUE, US"MAIL received");
059ec3d9
PH
4449 smtp_reset(reset_point);
4450 toomany = FALSE;
4451 sender_data = recipient_data = NULL;
4452
4453 /* Loop, checking for ESMTP additions to the MAIL FROM command. */
4454
4455 if (esmtp) for(;;)
4456 {
4457 uschar *name, *value, *end;
4458 unsigned long int size;
d27f98fe 4459 BOOL arg_error = FALSE;
059ec3d9
PH
4460
4461 if (!extract_option(&name, &value)) break;
4462
d27f98fe 4463 for (mail_args = env_mail_type_list;
2ef7ed08 4464 mail_args->value != ENV_MAIL_OPT_NULL;
d27f98fe
TL
4465 mail_args++
4466 )
d27f98fe
TL
4467 if (strcmpic(name, mail_args->name) == 0)
4468 break;
d27f98fe
TL
4469 if (mail_args->need_value && strcmpic(value, US"") == 0)
4470 break;
059ec3d9 4471
d27f98fe 4472 switch(mail_args->value)
059ec3d9 4473 {
d27f98fe
TL
4474 /* Handle SIZE= by reading the value. We don't do the check till later,
4475 in order to be able to log the sender address on failure. */
4476 case ENV_MAIL_OPT_SIZE:
d27f98fe 4477 if (((size = Ustrtoul(value, &end, 10)), *end == 0))
059ec3d9 4478 {
d27f98fe
TL
4479 if ((size == ULONG_MAX && errno == ERANGE) || size > INT_MAX)
4480 size = INT_MAX;
4481 message_size = (int)size;
059ec3d9
PH
4482 }
4483 else
d27f98fe
TL
4484 arg_error = TRUE;
4485 break;
059ec3d9 4486
d27f98fe
TL
4487 /* If this session was initiated with EHLO and accept_8bitmime is set,
4488 Exim will have indicated that it supports the BODY=8BITMIME option. In
4489 fact, it does not support this according to the RFCs, in that it does not
4490 take any special action for forwarding messages containing 8-bit
4491 characters. That is why accept_8bitmime is not the default setting, but
4492 some sites want the action that is provided. We recognize both "8BITMIME"
4493 and "7BIT" as body types, but take no action. */
4494 case ENV_MAIL_OPT_BODY:
3c0a92dc 4495 if (accept_8bitmime) {
9d4319df 4496 if (strcmpic(value, US"8BITMIME") == 0)
3c0a92dc 4497 body_8bitmime = 8;
9d4319df 4498 else if (strcmpic(value, US"7BIT") == 0)
3c0a92dc 4499 body_8bitmime = 7;
9d4319df
JH
4500 else
4501 {
3c0a92dc
JH
4502 body_8bitmime = 0;
4503 done = synprot_error(L_smtp_syntax_error, 501, NULL,
4504 US"invalid data for BODY");
4505 goto COMMAND_LOOP;
9d4319df 4506 }
3c0a92dc
JH
4507 DEBUG(D_receive) debug_printf("8BITMIME: %d\n", body_8bitmime);
4508 break;
4509 }
d27f98fe
TL
4510 arg_error = TRUE;
4511 break;
059ec3d9 4512
6c1c3d1d
WB
4513 /* Handle the two DSN options, but only if configured to do so (which
4514 will have caused "DSN" to be given in the EHLO response). The code itself
4515 is included only if configured in at build time. */
4516
4517 case ENV_MAIL_OPT_RET:
9d4319df
JH
4518 if (dsn_advertised)
4519 {
6c1c3d1d 4520 /* Check if RET has already been set */
9d4319df
JH
4521 if (dsn_ret > 0)
4522 {
6c1c3d1d
WB
4523 synprot_error(L_smtp_syntax_error, 501, NULL,
4524 US"RET can be specified once only");
4525 goto COMMAND_LOOP;
9d4319df
JH
4526 }
4527 dsn_ret = strcmpic(value, US"HDRS") == 0
4528 ? dsn_ret_hdrs
4529 : strcmpic(value, US"FULL") == 0
4530 ? dsn_ret_full
4531 : 0;
6c1c3d1d
WB
4532 DEBUG(D_receive) debug_printf("DSN_RET: %d\n", dsn_ret);
4533 /* Check for invalid invalid value, and exit with error */
9d4319df
JH
4534 if (dsn_ret == 0)
4535 {
6c1c3d1d
WB
4536 synprot_error(L_smtp_syntax_error, 501, NULL,
4537 US"Value for RET is invalid");
4538 goto COMMAND_LOOP;
9d4319df
JH
4539 }
4540 }
6c1c3d1d
WB
4541 break;
4542 case ENV_MAIL_OPT_ENVID:
9d4319df
JH
4543 if (dsn_advertised)
4544 {
6c1c3d1d 4545 /* Check if the dsn envid has been already set */
9d4319df
JH
4546 if (dsn_envid != NULL)
4547 {
6c1c3d1d
WB
4548 synprot_error(L_smtp_syntax_error, 501, NULL,
4549 US"ENVID can be specified once only");
4550 goto COMMAND_LOOP;
9d4319df 4551 }
6c1c3d1d
WB
4552 dsn_envid = string_copy(value);
4553 DEBUG(D_receive) debug_printf("DSN_ENVID: %s\n", dsn_envid);
9d4319df 4554 }
6c1c3d1d 4555 break;
6c1c3d1d 4556
d27f98fe
TL
4557 /* Handle the AUTH extension. If the value given is not "<>" and either
4558 the ACL says "yes" or there is no ACL but the sending host is
4559 authenticated, we set it up as the authenticated sender. However, if the
4560 authenticator set a condition to be tested, we ignore AUTH on MAIL unless
4561 the condition is met. The value of AUTH is an xtext, which means that +,
4562 = and cntrl chars are coded in hex; however "<>" is unaffected by this
4563 coding. */
4564 case ENV_MAIL_OPT_AUTH:
4565 if (Ustrcmp(value, "<>") != 0)
4566 {
4567 int rc;
4568 uschar *ignore_msg;
059ec3d9 4569
d27f98fe
TL
4570 if (auth_xtextdecode(value, &authenticated_sender) < 0)
4571 {
4572 /* Put back terminator overrides for error message */
d27f98fe 4573 value[-1] = '=';
fd98a5c6 4574 name[-1] = ' ';
d27f98fe
TL
4575 done = synprot_error(L_smtp_syntax_error, 501, NULL,
4576 US"invalid data for AUTH");
4577 goto COMMAND_LOOP;
4578 }
4579 if (acl_smtp_mailauth == NULL)
4580 {
4581 ignore_msg = US"client not authenticated";
4582 rc = (sender_host_authenticated != NULL)? OK : FAIL;
4583 }
4584 else
4585 {
4586 ignore_msg = US"rejected by ACL";
4587 rc = acl_check(ACL_WHERE_MAILAUTH, NULL, acl_smtp_mailauth,
4588 &user_msg, &log_msg);
4589 }
94431adb 4590
d27f98fe
TL
4591 switch (rc)
4592 {
4593 case OK:
9d4319df
JH
4594 if (authenticated_by == NULL ||
4595 authenticated_by->mail_auth_condition == NULL ||
4596 expand_check_condition(authenticated_by->mail_auth_condition,
4597 authenticated_by->name, US"authenticator"))
4598 break; /* Accept the AUTH */
94431adb 4599
9d4319df
JH
4600 ignore_msg = US"server_mail_auth_condition failed";
4601 if (authenticated_id != NULL)
4602 ignore_msg = string_sprintf("%s: authenticated ID=\"%s\"",
4603 ignore_msg, authenticated_id);
94431adb 4604
d27f98fe 4605 /* Fall through */
94431adb 4606
d27f98fe 4607 case FAIL:
9d4319df
JH
4608 authenticated_sender = NULL;
4609 log_write(0, LOG_MAIN, "ignoring AUTH=%s from %s (%s)",
4610 value, host_and_ident(TRUE), ignore_msg);
4611 break;
94431adb 4612
d27f98fe
TL
4613 /* Should only get DEFER or ERROR here. Put back terminator
4614 overrides for error message */
94431adb 4615
d27f98fe 4616 default:
9d4319df
JH
4617 value[-1] = '=';
4618 name[-1] = ' ';
4619 (void)smtp_handle_acl_fail(ACL_WHERE_MAILAUTH, rc, user_msg,
4620 log_msg);
4621 goto COMMAND_LOOP;
d27f98fe 4622 }
059ec3d9 4623 }
d27f98fe 4624 break;
fd98a5c6 4625
8ccd00b1 4626#ifndef DISABLE_PRDR
fd98a5c6 4627 case ENV_MAIL_OPT_PRDR:
8ccd00b1 4628 if (prdr_enable)
fd98a5c6
JH
4629 prdr_requested = TRUE;
4630 break;
4631#endif
4632
8c5d388a 4633#ifdef SUPPORT_I18N
d1a13eea
JH
4634 case ENV_MAIL_OPT_UTF8:
4635 if (smtputf8_advertised)
e524074d 4636 {
90341c71
JH
4637 int old_pool = store_pool;
4638
e524074d 4639 DEBUG(D_receive) debug_printf("smtputf8 requested\n");
9d4319df 4640 message_smtputf8 = allow_utf8_domains = TRUE;
90341c71 4641 store_pool = POOL_PERM;
5a886ce7 4642 received_protocol = string_sprintf("utf8%s", received_protocol);
90341c71 4643 store_pool = old_pool;
e524074d 4644 }
d1a13eea
JH
4645 break;
4646#endif
2ef7ed08 4647 /* No valid option. Stick back the terminator characters and break
fd98a5c6 4648 the loop. Do the name-terminator second as extract_option sets
2ef7ed08
HSHR
4649 value==name when it found no equal-sign.
4650 An error for a malformed address will occur. */
4651 case ENV_MAIL_OPT_NULL:
d27f98fe 4652 value[-1] = '=';
fd98a5c6
JH
4653 name[-1] = ' ';
4654 arg_error = TRUE;
d27f98fe 4655 break;
2ef7ed08
HSHR
4656
4657 default: assert(0);
059ec3d9 4658 }
d27f98fe
TL
4659 /* Break out of for loop if switch() had bad argument or
4660 when start of the email address is reached */
4661 if (arg_error) break;
059ec3d9
PH
4662 }
4663
4664 /* If we have passed the threshold for rate limiting, apply the current
4665 delay, and update it for next time, provided this is a limited host. */
4666
4667 if (smtp_mailcmd_count > smtp_rlm_threshold &&
4668 verify_check_host(&smtp_ratelimit_hosts) == OK)
4669 {
4670 DEBUG(D_receive) debug_printf("rate limit MAIL: delay %.3g sec\n",
4671 smtp_delay_mail/1000.0);
4672 millisleep((int)smtp_delay_mail);
4673 smtp_delay_mail *= smtp_rlm_factor;
4674 if (smtp_delay_mail > (double)smtp_rlm_limit)
4675 smtp_delay_mail = (double)smtp_rlm_limit;
4676 }
4677
4678 /* Now extract the address, first applying any SMTP-time rewriting. The
4679 TRUE flag allows "<>" as a sender address. */
4680
9d4319df
JH
4681 raw_sender = rewrite_existflags & rewrite_smtp
4682 ? rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
4683 global_rewrite_rules)
4684 : smtp_cmd_data;
059ec3d9 4685
059ec3d9
PH
4686 raw_sender =
4687 parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain,
4688 TRUE);
059ec3d9 4689
2685d6e0 4690 if (!raw_sender)
059ec3d9 4691 {
ca86f471 4692 done = synprot_error(L_smtp_syntax_error, 501, smtp_cmd_data, errmess);
059ec3d9
PH
4693 break;
4694 }
4695
4696 sender_address = raw_sender;
4697
4698 /* If there is a configured size limit for mail, check that this message
4699 doesn't exceed it. The check is postponed to this point so that the sender
4700 can be logged. */
4701
4702 if (thismessage_size_limit > 0 && message_size > thismessage_size_limit)
4703 {
925ac8e4 4704 smtp_printf("552 Message size exceeds maximum permitted\r\n", FALSE);
059ec3d9
PH
4705 log_write(L_size_reject,
4706 LOG_MAIN|LOG_REJECT, "rejected MAIL FROM:<%s> %s: "
4707 "message too big: size%s=%d max=%d",
4708 sender_address,
4709 host_and_ident(TRUE),
4710 (message_size == INT_MAX)? ">" : "",
4711 message_size,
4712 thismessage_size_limit);
4713 sender_address = NULL;
4714 break;
4715 }
4716
4717 /* Check there is enough space on the disk unless configured not to.
4718 When smtp_check_spool_space is set, the check is for thismessage_size_limit
4719 plus the current message - i.e. we accept the message only if it won't
4720 reduce the space below the threshold. Add 5000 to the size to allow for
4721 overheads such as the Received: line and storing of recipients, etc.
4722 By putting the check here, even when SIZE is not given, it allow VRFY
4723 and EXPN etc. to be used when space is short. */
4724
4725 if (!receive_check_fs(
4726 (smtp_check_spool_space && message_size >= 0)?
4727 message_size + 5000 : 0))
4728 {
925ac8e4 4729 smtp_printf("452 Space shortage, please try later\r\n", FALSE);
059ec3d9
PH
4730 sender_address = NULL;
4731 break;
4732 }
4733
4734 /* If sender_address is unqualified, reject it, unless this is a locally
4735 generated message, or the sending host or net is permitted to send
4736 unqualified addresses - typically local machines behaving as MUAs -
4737 in which case just qualify the address. The flag is set above at the start
4738 of the SMTP connection. */
4739
4740 if (sender_domain == 0 && sender_address[0] != 0)
4741 {
4742 if (allow_unqualified_sender)
4743 {
4744 sender_domain = Ustrlen(sender_address) + 1;
4745 sender_address = rewrite_address_qualify(sender_address, FALSE);
4746 DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
4747 raw_sender);
4748 }
4749 else
4750 {
925ac8e4 4751 smtp_printf("501 %s: sender address must contain a domain\r\n", FALSE,
ca86f471 4752 smtp_cmd_data);
059ec3d9
PH
4753 log_write(L_smtp_syntax_error,
4754 LOG_MAIN|LOG_REJECT,
4755 "unqualified sender rejected: <%s> %s%s",
4756 raw_sender,
4757 host_and_ident(TRUE),
4758 host_lookup_msg);
4759 sender_address = NULL;
4760 break;
4761 }
4762 }
4763
a14e5636
PH
4764 /* Apply an ACL check if one is defined, before responding. Afterwards,
4765 when pipelining is not advertised, do another sync check in case the ACL
4766 delayed and the client started sending in the meantime. */
059ec3d9 4767
8ccd00b1 4768 if (acl_smtp_mail)
a14e5636
PH
4769 {
4770 rc = acl_check(ACL_WHERE_MAIL, NULL, acl_smtp_mail, &user_msg, &log_msg);
4771 if (rc == OK && !pipelining_advertised && !check_sync())
4772 goto SYNC_FAILURE;
4773 }
8ccd00b1
JH
4774 else
4775 rc = OK;
059ec3d9
PH
4776
4777 if (rc == OK || rc == DISCARD)
4778 {
925ac8e4
JH
4779 BOOL more = pipeline_response();
4780
8ccd00b1 4781 if (!user_msg)
925ac8e4 4782 smtp_printf("%s%s%s", more, US"250 OK",
8ccd00b1
JH
4783 #ifndef DISABLE_PRDR
4784 prdr_requested ? US", PRDR Requested" : US"",
4785 #else
fd98a5c6 4786 US"",
8ccd00b1 4787 #endif
fd98a5c6 4788 US"\r\n");
94431adb 4789 else
fd98a5c6 4790 {
8ccd00b1
JH
4791 #ifndef DISABLE_PRDR
4792 if (prdr_requested)
fd98a5c6
JH
4793 user_msg = string_sprintf("%s%s", user_msg, US", PRDR Requested");
4794 #endif
8ccd00b1 4795 smtp_user_msg(US"250", user_msg);
fd98a5c6 4796 }
059ec3d9
PH
4797 smtp_delay_rcpt = smtp_rlr_base;
4798 recipients_discarded = (rc == DISCARD);
4799 was_rej_mail = FALSE;
4800 }
059ec3d9
PH
4801 else
4802 {
4803 done = smtp_handle_acl_fail(ACL_WHERE_MAIL, rc, user_msg, log_msg);
4804 sender_address = NULL;
4805 }
4806 break;
4807
4808
2679d413
PH
4809 /* The RCPT command requires an address as an operand. There may be any
4810 number of RCPT commands, specifying multiple recipients. We build them all
4811 into a data structure. The start/end values given by parse_extract_address
4812 are not used, as we keep only the extracted address. */
059ec3d9
PH
4813
4814 case RCPT_CMD:
b4ed4da0 4815 HAD(SCH_RCPT);
059ec3d9 4816 rcpt_count++;
2679d413 4817 was_rcpt = rcpt_in_progress = TRUE;
059ec3d9
PH
4818
4819 /* There must be a sender address; if the sender was rejected and
4820 pipelining was advertised, we assume the client was pipelining, and do not
4821 count this as a protocol error. Reset was_rej_mail so that further RCPTs
4822 get the same treatment. */
4823
4824 if (sender_address == NULL)
4825 {
4826 if (pipelining_advertised && last_was_rej_mail)
4827 {
925ac8e4 4828 smtp_printf("503 sender not yet given\r\n", FALSE);
059ec3d9
PH
4829 was_rej_mail = TRUE;
4830 }
4831 else
4832 {
4833 done = synprot_error(L_smtp_protocol_error, 503, NULL,
4834 US"sender not yet given");
4835 was_rcpt = FALSE; /* Not a valid RCPT */
4836 }
4837 rcpt_fail_count++;
4838 break;
4839 }
4840
4841 /* Check for an operand */
4842
ca86f471 4843 if (smtp_cmd_data[0] == 0)
059ec3d9
PH
4844 {
4845 done = synprot_error(L_smtp_syntax_error, 501, NULL,
4846 US"RCPT must have an address operand");
4847 rcpt_fail_count++;
4848 break;
4849 }
50dc7409 4850
6c1c3d1d
WB
4851 /* Set the DSN flags orcpt and dsn_flags from the session*/
4852 orcpt = NULL;
4853 flags = 0;
4854
4855 if (esmtp) for(;;)
4856 {
45500060 4857 uschar *name, *value;
6c1c3d1d
WB
4858
4859 if (!extract_option(&name, &value))
6c1c3d1d 4860 break;
6c1c3d1d
WB
4861
4862 if (dsn_advertised && strcmpic(name, US"ORCPT") == 0)
4863 {
4864 /* Check whether orcpt has been already set */
45500060
JH
4865 if (orcpt)
4866 {
6c1c3d1d
WB
4867 synprot_error(L_smtp_syntax_error, 501, NULL,
4868 US"ORCPT can be specified once only");
4869 goto COMMAND_LOOP;
4870 }
4871 orcpt = string_copy(value);
4872 DEBUG(D_receive) debug_printf("DSN orcpt: %s\n", orcpt);
4873 }
4874
4875 else if (dsn_advertised && strcmpic(name, US"NOTIFY") == 0)
4876 {
4877 /* Check if the notify flags have been already set */
45500060
JH
4878 if (flags > 0)
4879 {
6c1c3d1d
WB
4880 synprot_error(L_smtp_syntax_error, 501, NULL,
4881 US"NOTIFY can be specified once only");
4882 goto COMMAND_LOOP;
4883 }
45500060
JH
4884 if (strcmpic(value, US"NEVER") == 0)
4885 flags |= rf_notify_never;
4886 else
6c1c3d1d
WB
4887 {
4888 uschar *p = value;
4889 while (*p != 0)
4890 {
4891 uschar *pp = p;
4892 while (*pp != 0 && *pp != ',') pp++;
45500060
JH
4893 if (*pp == ',') *pp++ = 0;
4894 if (strcmpic(p, US"SUCCESS") == 0)
4895 {
4896 DEBUG(D_receive) debug_printf("DSN: Setting notify success\n");
4897 flags |= rf_notify_success;
6c1c3d1d 4898 }
45500060
JH
4899 else if (strcmpic(p, US"FAILURE") == 0)
4900 {
4901 DEBUG(D_receive) debug_printf("DSN: Setting notify failure\n");
4902 flags |= rf_notify_failure;
6c1c3d1d 4903 }
45500060
JH
4904 else if (strcmpic(p, US"DELAY") == 0)
4905 {
4906 DEBUG(D_receive) debug_printf("DSN: Setting notify delay\n");
4907 flags |= rf_notify_delay;
6c1c3d1d 4908 }
45500060
JH
4909 else
4910 {
6c1c3d1d
WB
4911 /* Catch any strange values */
4912 synprot_error(L_smtp_syntax_error, 501, NULL,
4913 US"Invalid value for NOTIFY parameter");
4914 goto COMMAND_LOOP;
4915 }
4916 p = pp;
4917 }
4918 DEBUG(D_receive) debug_printf("DSN Flags: %x\n", flags);
4919 }
4920 }
4921
4922 /* Unknown option. Stick back the terminator characters and break
4923 the loop. An error for a malformed address will occur. */
4924
4925 else
4926 {
4927 DEBUG(D_receive) debug_printf("Invalid RCPT option: %s : %s\n", name, value);
4928 name[-1] = ' ';
4929 value[-1] = '=';
4930 break;
4931 }
4932 }
059ec3d9
PH
4933
4934 /* Apply SMTP rewriting then extract the working address. Don't allow "<>"
4935 as a recipient address */
4936
05392bbc
JH
4937 recipient = rewrite_existflags & rewrite_smtp
4938 ? rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
4939 global_rewrite_rules)
4940 : smtp_cmd_data;
059ec3d9 4941
2685d6e0
JH
4942 if (!(recipient = parse_extract_address(recipient, &errmess, &start, &end,
4943 &recipient_domain, FALSE)))
059ec3d9 4944 {
ca86f471 4945 done = synprot_error(L_smtp_syntax_error, 501, smtp_cmd_data, errmess);
059ec3d9
PH
4946 rcpt_fail_count++;
4947 break;
4948 }
4949
4950 /* If the recipient address is unqualified, reject it, unless this is a
4951 locally generated message. However, unqualified addresses are permitted
4952 from a configured list of hosts and nets - typically when behaving as
4953 MUAs rather than MTAs. Sad that SMTP is used for both types of traffic,
4954 really. The flag is set at the start of the SMTP connection.
4955
4956 RFC 1123 talks about supporting "the reserved mailbox postmaster"; I always
4957 assumed this meant "reserved local part", but the revision of RFC 821 and
4958 friends now makes it absolutely clear that it means *mailbox*. Consequently
4959 we must always qualify this address, regardless. */
4960
c39b93a6 4961 if (!recipient_domain)
2685d6e0
JH
4962 if (!(recipient_domain = qualify_recipient(&recipient, smtp_cmd_data,
4963 US"recipient")))
059ec3d9
PH
4964 {
4965 rcpt_fail_count++;
059ec3d9
PH
4966 break;
4967 }
059ec3d9
PH
4968
4969 /* Check maximum allowed */
4970
4971 if (rcpt_count > recipients_max && recipients_max > 0)
4972 {
4973 if (recipients_max_reject)
4974 {
4975 rcpt_fail_count++;
925ac8e4 4976 smtp_printf("552 too many recipients\r\n", FALSE);
059ec3d9
PH
4977 if (!toomany)
4978 log_write(0, LOG_MAIN|LOG_REJECT, "too many recipients: message "
4979 "rejected: sender=<%s> %s", sender_address, host_and_ident(TRUE));
4980 }
4981 else
4982 {
4983 rcpt_defer_count++;
925ac8e4 4984 smtp_printf("452 too many recipients\r\n", FALSE);
059ec3d9
PH
4985 if (!toomany)
4986 log_write(0, LOG_MAIN|LOG_REJECT, "too many recipients: excess "
4987 "temporarily rejected: sender=<%s> %s", sender_address,
4988 host_and_ident(TRUE));
4989 }
4990
4991 toomany = TRUE;
4992 break;
4993 }
4994
4995 /* If we have passed the threshold for rate limiting, apply the current
4996 delay, and update it for next time, provided this is a limited host. */
4997
4998 if (rcpt_count > smtp_rlr_threshold &&
4999 verify_check_host(&smtp_ratelimit_hosts) == OK)
5000 {
5001 DEBUG(D_receive) debug_printf("rate limit RCPT: delay %.3g sec\n",
5002 smtp_delay_rcpt/1000.0);
5003 millisleep((int)smtp_delay_rcpt);
5004 smtp_delay_rcpt *= smtp_rlr_factor;
5005 if (smtp_delay_rcpt > (double)smtp_rlr_limit)
5006 smtp_delay_rcpt = (double)smtp_rlr_limit;
5007 }
5008
5009 /* If the MAIL ACL discarded all the recipients, we bypass ACL checking
a14e5636
PH
5010 for them. Otherwise, check the access control list for this recipient. As
5011 there may be a delay in this, re-check for a synchronization error
5012 afterwards, unless pipelining was advertised. */
059ec3d9 5013
a23ff3b4
JH
5014 if (recipients_discarded)
5015 rc = DISCARD;
5016 else
5017 if ( (rc = acl_check(ACL_WHERE_RCPT, recipient, acl_smtp_rcpt, &user_msg,
5018 &log_msg)) == OK
5019 && !pipelining_advertised && !check_sync())
a14e5636 5020 goto SYNC_FAILURE;
059ec3d9
PH
5021
5022 /* The ACL was happy */
5023
5024 if (rc == OK)
5025 {
925ac8e4
JH
5026 BOOL more = pipeline_response();
5027
a23ff3b4
JH
5028 if (user_msg)
5029 smtp_user_msg(US"250", user_msg);
5030 else
925ac8e4 5031 smtp_printf("250 Accepted\r\n", more);
059ec3d9 5032 receive_add_recipient(recipient, -1);
94431adb 5033
6c1c3d1d 5034 /* Set the dsn flags in the recipients_list */
7ade712c
JH
5035 recipients_list[recipients_count-1].orcpt = orcpt;
5036 recipients_list[recipients_count-1].dsn_flags = flags;
6c1c3d1d 5037
7ade712c
JH
5038 DEBUG(D_receive) debug_printf("DSN: orcpt: %s flags: %d\n",
5039 recipients_list[recipients_count-1].orcpt,
5040 recipients_list[recipients_count-1].dsn_flags);
059ec3d9
PH
5041 }
5042
5043 /* The recipient was discarded */
5044
5045 else if (rc == DISCARD)
5046 {
a23ff3b4
JH
5047 if (user_msg)
5048 smtp_user_msg(US"250", user_msg);
5049 else
925ac8e4 5050 smtp_printf("250 Accepted\r\n", FALSE);
059ec3d9
PH
5051 rcpt_fail_count++;
5052 discarded = TRUE;
1f12df4d 5053 log_write(0, LOG_MAIN|LOG_REJECT, "%s F=<%s> RCPT %s: "
059ec3d9 5054 "discarded by %s ACL%s%s", host_and_ident(TRUE),
1f12df4d 5055 sender_address_unrewritten? sender_address_unrewritten : sender_address,
3ee512ff 5056 smtp_cmd_argument, recipients_discarded? "MAIL" : "RCPT",
1f12df4d 5057 log_msg ? US": " : US"", log_msg ? log_msg : US"");
059ec3d9
PH
5058 }
5059
5060 /* Either the ACL failed the address, or it was deferred. */
5061
5062 else
5063 {
5064 if (rc == FAIL) rcpt_fail_count++; else rcpt_defer_count++;
5065 done = smtp_handle_acl_fail(ACL_WHERE_RCPT, rc, user_msg, log_msg);
5066 }
5067 break;
5068
5069
5070 /* The DATA command is legal only if it follows successful MAIL FROM
5071 and RCPT TO commands. However, if pipelining is advertised, a bad DATA is
5072 not counted as a protocol error if it follows RCPT (which must have been
5073 rejected if there are no recipients.) This function is complete when a
5074 valid DATA command is encountered.
5075
5076 Note concerning the code used: RFC 2821 says this:
5077
5078 - If there was no MAIL, or no RCPT, command, or all such commands
5079 were rejected, the server MAY return a "command out of sequence"
5080 (503) or "no valid recipients" (554) reply in response to the
5081 DATA command.
5082
5083 The example in the pipelining RFC 2920 uses 554, but I use 503 here
2679d413
PH
5084 because it is the same whether pipelining is in use or not.
5085
5086 If all the RCPT commands that precede DATA provoked the same error message
5087 (often indicating some kind of system error), it is helpful to include it
5088 with the DATA rejection (an idea suggested by Tony Finch). */
059ec3d9 5089
18481de3
JH
5090 case BDAT_CMD:
5091 HAD(SCH_BDAT);
5092 {
5093 int n;
5094
5095 if (chunking_state != CHUNKING_OFFERED)
5096 {
5097 done = synprot_error(L_smtp_protocol_error, 503, NULL,
5098 US"BDAT command used when CHUNKING not advertised");
5099 break;
5100 }
5101
5102 /* grab size, endmarker */
5103
5104 if (sscanf(CS smtp_cmd_data, "%u %n", &chunking_datasize, &n) < 1)
5105 {
7e3ce68e 5106 done = synprot_error(L_smtp_protocol_error, 501, NULL,
18481de3
JH
5107 US"missing size for BDAT command");
5108 break;
5109 }
5110 chunking_state = strcmpic(smtp_cmd_data+n, US"LAST") == 0
5111 ? CHUNKING_LAST : CHUNKING_ACTIVE;
7e3ce68e 5112 chunking_data_left = chunking_datasize;
bd8fbe36
JH
5113 DEBUG(D_receive) debug_printf("chunking state %d, %d bytes\n",
5114 (int)chunking_state, chunking_data_left);
7e3ce68e
JH
5115
5116 lwr_receive_getc = receive_getc;
0d81dabc 5117 lwr_receive_getbuf = receive_getbuf;
7e3ce68e
JH
5118 lwr_receive_ungetc = receive_ungetc;
5119 receive_getc = bdat_getc;
5120 receive_ungetc = bdat_ungetc;
18481de3 5121
18481de3
JH
5122 goto DATA_BDAT;
5123 }
5124
059ec3d9 5125 case DATA_CMD:
b4ed4da0 5126 HAD(SCH_DATA);
18481de3
JH
5127
5128 DATA_BDAT: /* Common code for DATA and BDAT */
059ec3d9
PH
5129 if (!discarded && recipients_count <= 0)
5130 {
2679d413
PH
5131 if (rcpt_smtp_response_same && rcpt_smtp_response != NULL)
5132 {
5133 uschar *code = US"503";
5134 int len = Ustrlen(rcpt_smtp_response);
5135 smtp_respond(code, 3, FALSE, US"All RCPT commands were rejected with "
5136 "this error:");
5137 /* Responses from smtp_printf() will have \r\n on the end */
5138 if (len > 2 && rcpt_smtp_response[len-2] == '\r')
5139 rcpt_smtp_response[len-2] = 0;
5140 smtp_respond(code, 3, FALSE, rcpt_smtp_response);
5141 }
059ec3d9 5142 if (pipelining_advertised && last_was_rcpt)
925ac8e4 5143 smtp_printf("503 Valid RCPT command must precede %s\r\n", FALSE,
18481de3 5144 smtp_names[smtp_connection_had[smtp_ch_index-1]]);
059ec3d9
PH
5145 else
5146 done = synprot_error(L_smtp_protocol_error, 503, NULL,
18481de3
JH
5147 smtp_connection_had[smtp_ch_index-1] == SCH_DATA
5148 ? US"valid RCPT command must precede DATA"
5149 : US"valid RCPT command must precede BDAT");
45bd315d
JH
5150
5151 if (chunking_state > CHUNKING_OFFERED)
5152 bdat_flush_data();
059ec3d9
PH
5153 break;
5154 }
5155
5156 if (toomany && recipients_max_reject)
5157 {
5158 sender_address = NULL; /* This will allow a new MAIL without RSET */
5159 sender_address_unrewritten = NULL;
925ac8e4 5160 smtp_printf("554 Too many recipients\r\n", FALSE);
059ec3d9
PH
5161 break;
5162 }
8e669ac1 5163
7e3ce68e 5164 if (chunking_state > CHUNKING_OFFERED)
a23ff3b4 5165 rc = OK; /* No predata ACL or go-ahead output for BDAT */
18481de3 5166 else
8e669ac1 5167 {
7e3ce68e
JH
5168 /* If there is an ACL, re-check the synchronization afterwards, since the
5169 ACL may have delayed. To handle cutthrough delivery enforce a dummy call
5170 to get the DATA command sent. */
059ec3d9 5171
7e3ce68e
JH
5172 if (acl_smtp_predata == NULL && cutthrough.fd < 0)
5173 rc = OK;
5174 else
5175 {
5176 uschar * acl = acl_smtp_predata ? acl_smtp_predata : US"accept";
5177 enable_dollar_recipients = TRUE;
5178 rc = acl_check(ACL_WHERE_PREDATA, NULL, acl, &user_msg,
5179 &log_msg);
5180 enable_dollar_recipients = FALSE;
5181 if (rc == OK && !check_sync())
5182 goto SYNC_FAILURE;
5183
5184 if (rc != OK)
5185 { /* Either the ACL failed the address, or it was deferred. */
5186 done = smtp_handle_acl_fail(ACL_WHERE_PREDATA, rc, user_msg, log_msg);
5187 break;
5188 }
5189 }
5190
5191 if (user_msg)
5192 smtp_user_msg(US"354", user_msg);
5193 else
5194 smtp_printf(
925ac8e4 5195 "354 Enter message, ending with \".\" on a line by itself\r\n", FALSE);
059ec3d9
PH
5196 }
5197
8d330698
JH
5198#ifdef TCP_QUICKACK
5199 if (smtp_in) /* all ACKs needed to ramp window up for bulk data */
5200 (void) setsockopt(fileno(smtp_in), IPPROTO_TCP, TCP_QUICKACK,
5201 US &on, sizeof(on));
5202#endif
7e3ce68e
JH
5203 done = 3;
5204 message_ended = END_NOTENDED; /* Indicate in middle of data */
059ec3d9 5205
059ec3d9
PH
5206 break;
5207
5208
5209 case VRFY_CMD:
059ec3d9 5210 {
4f6ae5c3 5211 uschar * address;
059ec3d9 5212
4f6ae5c3 5213 HAD(SCH_VRFY);
059ec3d9 5214
05392bbc
JH
5215 if (!(address = parse_extract_address(smtp_cmd_data, &errmess,
5216 &start, &end, &recipient_domain, FALSE)))
5217 {
925ac8e4 5218 smtp_printf("501 %s\r\n", FALSE, errmess);
05392bbc
JH
5219 break;
5220 }
5221
c39b93a6 5222 if (!recipient_domain)
2685d6e0
JH
5223 if (!(recipient_domain = qualify_recipient(&address, smtp_cmd_data,
5224 US"verify")))
05392bbc 5225 break;
4f6ae5c3 5226
05392bbc 5227 if ((rc = acl_check(ACL_WHERE_VRFY, address, acl_smtp_vrfy,
4f6ae5c3
JH
5228 &user_msg, &log_msg)) != OK)
5229 done = smtp_handle_acl_fail(ACL_WHERE_VRFY, rc, user_msg, log_msg);
059ec3d9 5230 else
4f6ae5c3 5231 {
05392bbc
JH
5232 uschar * s = NULL;
5233 address_item * addr = deliver_make_addr(address, FALSE);
059ec3d9 5234
4f6ae5c3
JH
5235 switch(verify_address(addr, NULL, vopt_is_recipient | vopt_qualify, -1,
5236 -1, -1, NULL, NULL, NULL))
5237 {
5238 case OK:
5239 s = string_sprintf("250 <%s> is deliverable", address);
5240 break;
059ec3d9 5241
4f6ae5c3
JH
5242 case DEFER:
5243 s = (addr->user_message != NULL)?
5244 string_sprintf("451 <%s> %s", address, addr->user_message) :
5245 string_sprintf("451 Cannot resolve <%s> at this time", address);
5246 break;
059ec3d9 5247
4f6ae5c3
JH
5248 case FAIL:
5249 s = (addr->user_message != NULL)?
5250 string_sprintf("550 <%s> %s", address, addr->user_message) :
5251 string_sprintf("550 <%s> is not deliverable", address);
5252 log_write(0, LOG_MAIN, "VRFY failed for %s %s",
5253 smtp_cmd_argument, host_and_ident(TRUE));
5254 break;
5255 }
5256
925ac8e4 5257 smtp_printf("%s\r\n", FALSE, s);
4f6ae5c3
JH
5258 }
5259 break;
059ec3d9 5260 }
059ec3d9
PH
5261
5262
5263 case EXPN_CMD:
b4ed4da0 5264 HAD(SCH_EXPN);
64ffc24f 5265 rc = acl_check(ACL_WHERE_EXPN, NULL, acl_smtp_expn, &user_msg, &log_msg);
059ec3d9
PH
5266 if (rc != OK)
5267 done = smtp_handle_acl_fail(ACL_WHERE_EXPN, rc, user_msg, log_msg);
5268 else
5269 {
5270 BOOL save_log_testing_mode = log_testing_mode;
5271 address_test_mode = log_testing_mode = TRUE;
ca86f471 5272 (void) verify_address(deliver_make_addr(smtp_cmd_data, FALSE),
64ffc24f
PH
5273 smtp_out, vopt_is_recipient | vopt_qualify | vopt_expn, -1, -1, -1,
5274 NULL, NULL, NULL);
059ec3d9
PH
5275 address_test_mode = FALSE;
5276 log_testing_mode = save_log_testing_mode; /* true for -bh */
5277 }
5278 break;
5279
5280
5281 #ifdef SUPPORT_TLS
5282
5283 case STARTTLS_CMD:
b4ed4da0 5284 HAD(SCH_STARTTLS);
059ec3d9
PH
5285 if (!tls_advertised)
5286 {
5287 done = synprot_error(L_smtp_protocol_error, 503, NULL,
5288 US"STARTTLS command used when not advertised");
5289 break;
5290 }
5291
5292 /* Apply an ACL check if one is defined */
5293
4f6ae5c3
JH
5294 if ( acl_smtp_starttls
5295 && (rc = acl_check(ACL_WHERE_STARTTLS, NULL, acl_smtp_starttls,
5296 &user_msg, &log_msg)) != OK
5297 )
059ec3d9 5298 {
4f6ae5c3
JH
5299 done = smtp_handle_acl_fail(ACL_WHERE_STARTTLS, rc, user_msg, log_msg);
5300 break;
059ec3d9
PH
5301 }
5302
5303 /* RFC 2487 is not clear on when this command may be sent, though it
5304 does state that all information previously obtained from the client
4c04137d 5305 must be discarded if a TLS session is started. It seems reasonable to
059ec3d9
PH
5306 do an implied RSET when STARTTLS is received. */
5307
5308 incomplete_transaction_log(US"STARTTLS");
57cc2785 5309 cancel_cutthrough_connection(TRUE, US"STARTTLS received");
059ec3d9
PH
5310 smtp_reset(reset_point);
5311 toomany = FALSE;
5312 cmd_list[CMD_LIST_STARTTLS].is_mail_cmd = FALSE;
5313
da80c2a8
PP
5314 /* There's an attack where more data is read in past the STARTTLS command
5315 before TLS is negotiated, then assumed to be part of the secure session
5316 when used afterwards; we use segregated input buffers, so are not
5317 vulnerable, but we want to note when it happens and, for sheer paranoia,
5318 ensure that the buffer is "wiped".
5319 Pipelining sync checks will normally have protected us too, unless disabled
5320 by configuration. */
5321
5322 if (receive_smtp_buffered())
5323 {
5324 DEBUG(D_any)
18481de3 5325 debug_printf("Non-empty input buffer after STARTTLS; naive attack?\n");
817d9f57 5326 if (tls_in.active < 0)
da80c2a8
PP
5327 smtp_inend = smtp_inptr = smtp_inbuffer;
5328 /* and if TLS is already active, tls_server_start() should fail */
5329 }
5330
4c04137d 5331 /* There is nothing we value in the input buffer and if TLS is successfully
4e7ee012
PP
5332 negotiated, we won't use this buffer again; if TLS fails, we'll just read
5333 fresh content into it. The buffer contains arbitrary content from an
5334 untrusted remote source; eg: NOOP <shellcode>\r\nSTARTTLS\r\n
5335 It seems safest to just wipe away the content rather than leave it as a
5336 target to jump to. */
5337
bd8fbe36 5338 memset(smtp_inbuffer, 0, IN_BUFFER_SIZE);
4e7ee012 5339
059ec3d9
PH
5340 /* Attempt to start up a TLS session, and if successful, discard all
5341 knowledge that was obtained previously. At least, that's what the RFC says,
5342 and that's what happens by default. However, in order to work round YAEB,
5343 there is an option to remember the esmtp state. Sigh.
5344
5345 We must allow for an extra EHLO command and an extra AUTH command after
5346 STARTTLS that don't add to the nonmail command count. */
5347
cf0c6164
JH
5348 s = NULL;
5349 if ((rc = tls_server_start(tls_require_ciphers, &s)) == OK)
059ec3d9
PH
5350 {
5351 if (!tls_remember_esmtp)
5352 helo_seen = esmtp = auth_advertised = pipelining_advertised = FALSE;
5353 cmd_list[CMD_LIST_EHLO].is_mail_cmd = TRUE;
5354 cmd_list[CMD_LIST_AUTH].is_mail_cmd = TRUE;
b3ef41c9 5355 cmd_list[CMD_LIST_TLS_AUTH].is_mail_cmd = TRUE;
059ec3d9
PH
5356 if (sender_helo_name != NULL)
5357 {
5358 store_free(sender_helo_name);
5359 sender_helo_name = NULL;
5360 host_build_sender_fullhost(); /* Rebuild */
5361 set_process_info("handling incoming TLS connection from %s",
5362 host_and_ident(FALSE));
5363 }
e524074d
JH
5364 received_protocol =
5365 (sender_host_address ? protocols : protocols_local)
5366 [ (esmtp
5367 ? pextend + (sender_host_authenticated ? pauthed : 0)
5368 : pnormal)
5369 + (tls_in.active >= 0 ? pcrpted : 0)
5370 ];
059ec3d9
PH
5371
5372 sender_host_authenticated = NULL;
5373 authenticated_id = NULL;
5374 sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING;
5375 DEBUG(D_tls) debug_printf("TLS active\n");
5376 break; /* Successful STARTTLS */
5377 }
cf0c6164
JH
5378 else
5379 (void) smtp_log_tls_fail(s);
059ec3d9
PH
5380
5381 /* Some local configuration problem was discovered before actually trying
5382 to do a TLS handshake; give a temporary error. */
5383
cf0c6164 5384 if (rc == DEFER)
059ec3d9 5385 {
925ac8e4 5386 smtp_printf("454 TLS currently unavailable\r\n", FALSE);
059ec3d9
PH
5387 break;
5388 }
5389
5390 /* Hard failure. Reject everything except QUIT or closed connection. One
817d9f57 5391 cause for failure is a nested STARTTLS, in which case tls_in.active remains
059ec3d9
PH
5392 set, but we must still reject all incoming commands. */
5393
5394 DEBUG(D_tls) debug_printf("TLS failed to start\n");
bd8fbe36 5395 while (done <= 0) switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED))
059ec3d9 5396 {
60d10ce7
JH
5397 case EOF_CMD:
5398 log_write(L_smtp_connection, LOG_MAIN, "%s closed by EOF",
5399 smtp_get_connection_info());
5400 smtp_notquit_exit(US"tls-failed", NULL, NULL);
5401 done = 2;
5402 break;
8f128379 5403
60d10ce7
JH
5404 /* It is perhaps arguable as to which exit ACL should be called here,
5405 but as it is probably a situation that almost never arises, it
5406 probably doesn't matter. We choose to call the real QUIT ACL, which in
5407 some sense is perhaps "right". */
5408
5409 case QUIT_CMD:
5410 user_msg = NULL;
5411 if ( acl_smtp_quit
5412 && ((rc = acl_check(ACL_WHERE_QUIT, NULL, acl_smtp_quit, &user_msg,
5413 &log_msg)) == ERROR))
5414 log_write(0, LOG_MAIN|LOG_PANIC, "ACL for QUIT returned ERROR: %s",
5415 log_msg);
5416 if (user_msg)
5417 smtp_respond(US"221", 3, TRUE, user_msg);
5418 else
925ac8e4 5419 smtp_printf("221 %s closing connection\r\n", FALSE, smtp_active_hostname);
60d10ce7
JH
5420 log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT",
5421 smtp_get_connection_info());
5422 done = 2;
5423 break;
059ec3d9 5424
60d10ce7 5425 default:
925ac8e4 5426 smtp_printf("554 Security failure\r\n", FALSE);
60d10ce7 5427 break;
059ec3d9 5428 }
817d9f57 5429 tls_close(TRUE, TRUE);
059ec3d9
PH
5430 break;
5431 #endif
5432
5433
5434 /* The ACL for QUIT is provided for gathering statistical information or
5435 similar; it does not affect the response code, but it can supply a custom
5436 message. */
5437
5438 case QUIT_CMD:
7e3ce68e 5439 smtp_quit_handler(&user_msg, &log_msg);
059ec3d9 5440 done = 2;
059ec3d9
PH
5441 break;
5442
5443
5444 case RSET_CMD:
7e3ce68e 5445 smtp_rset_handler();
57cc2785 5446 cancel_cutthrough_connection(TRUE, US"RSET received");
059ec3d9
PH
5447 smtp_reset(reset_point);
5448 toomany = FALSE;
059ec3d9
PH
5449 break;
5450
5451
5452 case NOOP_CMD:
b4ed4da0 5453 HAD(SCH_NOOP);
925ac8e4 5454 smtp_printf("250 OK\r\n", FALSE);
059ec3d9
PH
5455 break;
5456
5457
b43a74ea
PH
5458 /* Show ETRN/EXPN/VRFY if there's an ACL for checking hosts; if actually
5459 used, a check will be done for permitted hosts. Show STARTTLS only if not
5460 already in a TLS session and if it would be advertised in the EHLO
5461 response. */
059ec3d9
PH
5462
5463 case HELP_CMD:
b4ed4da0 5464 HAD(SCH_HELP);
925ac8e4 5465 smtp_printf("214-Commands supported:\r\n", TRUE);
059ec3d9
PH
5466 {
5467 uschar buffer[256];
5468 buffer[0] = 0;
5469 Ustrcat(buffer, " AUTH");
5470 #ifdef SUPPORT_TLS
817d9f57 5471 if (tls_in.active < 0 &&
b43a74ea
PH
5472 verify_check_host(&tls_advertise_hosts) != FAIL)
5473 Ustrcat(buffer, " STARTTLS");
059ec3d9 5474 #endif
7e3ce68e 5475 Ustrcat(buffer, " HELO EHLO MAIL RCPT DATA BDAT");
059ec3d9
PH
5476 Ustrcat(buffer, " NOOP QUIT RSET HELP");
5477 if (acl_smtp_etrn != NULL) Ustrcat(buffer, " ETRN");
5478 if (acl_smtp_expn != NULL) Ustrcat(buffer, " EXPN");
5479 if (acl_smtp_vrfy != NULL) Ustrcat(buffer, " VRFY");
925ac8e4 5480 smtp_printf("214%s\r\n", FALSE, buffer);
059ec3d9
PH
5481 }
5482 break;
5483
5484
5485 case EOF_CMD:
5486 incomplete_transaction_log(US"connection lost");
8f128379
PH
5487 smtp_notquit_exit(US"connection-lost", US"421",
5488 US"%s lost input connection", smtp_active_hostname);
059ec3d9
PH
5489
5490 /* Don't log by default unless in the middle of a message, as some mailers
5491 just drop the call rather than sending QUIT, and it clutters up the logs.
5492 */
5493
a2673768 5494 if (sender_address || recipients_count > 0)
2ac25850 5495 log_write(L_lost_incoming_connection, LOG_MAIN,
a2673768
JH
5496 "unexpected %s while reading SMTP command from %s%s%s D=%s",
5497 sender_host_unknown ? "EOF" : "disconnection",
5498 tcp_in_fastopen && !tcp_in_fastopen_logged ? US"TFO " : US"",
5499 host_and_ident(FALSE), smtp_read_error,
5500 string_timesince(&smtp_connection_start)
5501 );
2ac25850
JH
5502
5503 else
a2673768
JH
5504 log_write(L_smtp_connection, LOG_MAIN, "%s %slost%s D=%s",
5505 smtp_get_connection_info(),
5506 tcp_in_fastopen && !tcp_in_fastopen_logged ? US"TFO " : US"",
5507 smtp_read_error,
5508 string_timesince(&smtp_connection_start)
5509 );
059ec3d9
PH
5510
5511 done = 1;
5512 break;
5513
5514
5515 case ETRN_CMD:
b4ed4da0 5516 HAD(SCH_ETRN);
059ec3d9
PH
5517 if (sender_address != NULL)
5518 {
5519 done = synprot_error(L_smtp_protocol_error, 503, NULL,
5520 US"ETRN is not permitted inside a transaction");
5521 break;
5522 }
5523
3ee512ff 5524 log_write(L_etrn, LOG_MAIN, "ETRN %s received from %s", smtp_cmd_argument,
059ec3d9
PH
5525 host_and_ident(FALSE));
5526
4f6ae5c3
JH
5527 if ((rc = acl_check(ACL_WHERE_ETRN, NULL, acl_smtp_etrn,
5528 &user_msg, &log_msg)) != OK)
059ec3d9
PH
5529 {
5530 done = smtp_handle_acl_fail(ACL_WHERE_ETRN, rc, user_msg, log_msg);
5531 break;
5532 }
5533
5534 /* Compute the serialization key for this command. */
5535
ca86f471 5536 etrn_serialize_key = string_sprintf("etrn-%s\n", smtp_cmd_data);
059ec3d9
PH
5537
5538 /* If a command has been specified for running as a result of ETRN, we
5539 permit any argument to ETRN. If not, only the # standard form is permitted,
5540 since that is strictly the only kind of ETRN that can be implemented
5541 according to the RFC. */
5542
5543 if (smtp_etrn_command != NULL)
5544 {
5545 uschar *error;
5546 BOOL rc;
5547 etrn_command = smtp_etrn_command;
ca86f471 5548 deliver_domain = smtp_cmd_data;
059ec3d9
PH
5549 rc = transport_set_up_command(&argv, smtp_etrn_command, TRUE, 0, NULL,
5550 US"ETRN processing", &error);
5551 deliver_domain = NULL;
5552 if (!rc)
5553 {
5554 log_write(0, LOG_MAIN|LOG_PANIC, "failed to set up ETRN command: %s",
5555 error);
925ac8e4 5556 smtp_printf("458 Internal failure\r\n", FALSE);
059ec3d9
PH
5557 break;
5558 }
5559 }
5560
5561 /* Else set up to call Exim with the -R option. */
5562
5563 else
5564 {
ca86f471 5565 if (*smtp_cmd_data++ != '#')
059ec3d9
PH
5566 {
5567 done = synprot_error(L_smtp_syntax_error, 501, NULL,
5568 US"argument must begin with #");
5569 break;
5570 }
5571 etrn_command = US"exim -R";
e37f8a84
JH
5572 argv = CUSS child_exec_exim(CEE_RETURN_ARGV, TRUE, NULL, TRUE,
5573 *queue_name ? 4 : 2,
5574 US"-R", smtp_cmd_data,
5575 US"-MCG", queue_name);
059ec3d9
PH
5576 }
5577
5578 /* If we are host-testing, don't actually do anything. */
5579
5580 if (host_checking)
5581 {
5582 HDEBUG(D_any)
5583 {
5584 debug_printf("ETRN command is: %s\n", etrn_command);
5585 debug_printf("ETRN command execution skipped\n");
5586 }
925ac8e4 5587 if (user_msg == NULL) smtp_printf("250 OK\r\n", FALSE);
4e88a19f 5588 else smtp_user_msg(US"250", user_msg);
059ec3d9
PH
5589 break;
5590 }
5591
5592
5593 /* If ETRN queue runs are to be serialized, check the database to
5594 ensure one isn't already running. */
5595
e8ae7214 5596 if (smtp_etrn_serialize && !enq_start(etrn_serialize_key, 1))
059ec3d9 5597 {
925ac8e4 5598 smtp_printf("458 Already processing %s\r\n", FALSE, smtp_cmd_data);
059ec3d9
PH
5599 break;
5600 }
5601
5602 /* Fork a child process and run the command. We don't want to have to
5603 wait for the process at any point, so set SIGCHLD to SIG_IGN before
5604 forking. It should be set that way anyway for external incoming SMTP,
5605 but we save and restore to be tidy. If serialization is required, we
5606 actually run the command in yet another process, so we can wait for it
5607 to complete and then remove the serialization lock. */
5608
5609 oldsignal = signal(SIGCHLD, SIG_IGN);
5610
5611 if ((pid = fork()) == 0)
5612 {
f1e894f3
PH
5613 smtp_input = FALSE; /* This process is not associated with the */
5614 (void)fclose(smtp_in); /* SMTP call any more. */
5615 (void)fclose(smtp_out);
059ec3d9
PH
5616
5617 signal(SIGCHLD, SIG_DFL); /* Want to catch child */
5618
5619 /* If not serializing, do the exec right away. Otherwise, fork down
5620 into another process. */
5621
5622 if (!smtp_etrn_serialize || (pid = fork()) == 0)
5623 {
5624 DEBUG(D_exec) debug_print_argv(argv);
5625 exim_nullstd(); /* Ensure std{in,out,err} exist */
5626 execv(CS argv[0], (char *const *)argv);
5627 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "exec of \"%s\" (ETRN) failed: %s",
5628 etrn_command, strerror(errno));
5629 _exit(EXIT_FAILURE); /* paranoia */
5630 }
5631
5632 /* Obey this if smtp_serialize and the 2nd fork yielded non-zero. That
5633 is, we are in the first subprocess, after forking again. All we can do
5634 for a failing fork is to log it. Otherwise, wait for the 2nd process to
5635 complete, before removing the serialization. */
5636
5637 if (pid < 0)
5638 log_write(0, LOG_MAIN|LOG_PANIC, "2nd fork for serialized ETRN "
5639 "failed: %s", strerror(errno));
5640 else
5641 {
5642 int status;
5643 DEBUG(D_any) debug_printf("waiting for serialized ETRN process %d\n",
5644 (int)pid);
5645 (void)wait(&status);
5646 DEBUG(D_any) debug_printf("serialized ETRN process %d ended\n",
5647 (int)pid);
5648 }
5649
5650 enq_end(etrn_serialize_key);
5651 _exit(EXIT_SUCCESS);
5652 }
5653
5654 /* Back in the top level SMTP process. Check that we started a subprocess
5655 and restore the signal state. */
5656
5657 if (pid < 0)
5658 {
5659 log_write(0, LOG_MAIN|LOG_PANIC, "fork of process for ETRN failed: %s",
5660 strerror(errno));
925ac8e4 5661 smtp_printf("458 Unable to fork process\r\n", FALSE);
059ec3d9
PH
5662 if (smtp_etrn_serialize) enq_end(etrn_serialize_key);
5663 }
4e88a19f
PH
5664 else
5665 {
925ac8e4 5666 if (user_msg == NULL) smtp_printf("250 OK\r\n", FALSE);
4e88a19f
PH
5667 else smtp_user_msg(US"250", user_msg);
5668 }
059ec3d9
PH
5669
5670 signal(SIGCHLD, oldsignal);
5671 break;
5672
5673
5674 case BADARG_CMD:
5675 done = synprot_error(L_smtp_syntax_error, 501, NULL,
5676 US"unexpected argument data");
5677 break;
5678
5679
5680 /* This currently happens only for NULLs, but could be extended. */
5681
5682 case BADCHAR_CMD:
5683 done = synprot_error(L_smtp_syntax_error, 0, NULL, /* Just logs */
5684 US"NULL character(s) present (shown as '?')");
925ac8e4 5685 smtp_printf("501 NULL characters are not allowed in SMTP commands\r\n", FALSE);
059ec3d9
PH
5686 break;
5687
5688
5689 case BADSYN_CMD:
a14e5636 5690 SYNC_FAILURE:
bd8fbe36
JH
5691 if (smtp_inend >= smtp_inbuffer + IN_BUFFER_SIZE)
5692 smtp_inend = smtp_inbuffer + IN_BUFFER_SIZE - 1;
059ec3d9
PH
5693 c = smtp_inend - smtp_inptr;
5694 if (c > 150) c = 150;
5695 smtp_inptr[c] = 0;
5696 incomplete_transaction_log(US"sync failure");
3af76a81 5697 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol synchronization error "
059ec3d9
PH
5698 "(next input sent too soon: pipelining was%s advertised): "
5699 "rejected \"%s\" %s next input=\"%s\"",
5700 pipelining_advertised? "" : " not",
3ee512ff 5701 smtp_cmd_buffer, host_and_ident(TRUE),
059ec3d9 5702 string_printing(smtp_inptr));
8f128379
PH
5703 smtp_notquit_exit(US"synchronization-error", US"554",
5704 US"SMTP synchronization error");
059ec3d9
PH
5705 done = 1; /* Pretend eof - drops connection */
5706 break;
5707
5708
5709 case TOO_MANY_NONMAIL_CMD:
ca86f471
PH
5710 s = smtp_cmd_buffer;
5711 while (*s != 0 && !isspace(*s)) s++;
059ec3d9
PH
5712 incomplete_transaction_log(US"too many non-mail commands");
5713 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
5714 "nonmail commands (last was \"%.*s\")", host_and_ident(FALSE),
6d9cfc47 5715 (int)(s - smtp_cmd_buffer), smtp_cmd_buffer);
8f128379 5716 smtp_notquit_exit(US"bad-commands", US"554", US"Too many nonmail commands");
059ec3d9
PH
5717 done = 1; /* Pretend eof - drops connection */
5718 break;
5719
cee5f132 5720#ifdef SUPPORT_PROXY
a3c86431 5721 case PROXY_FAIL_IGNORE_CMD:
925ac8e4 5722 smtp_printf("503 Command refused, required Proxy negotiation failed\r\n", FALSE);
a3c86431 5723 break;
cee5f132 5724#endif
059ec3d9
PH
5725
5726 default:
5727 if (unknown_command_count++ >= smtp_max_unknown_commands)
5728 {
5729 log_write(L_smtp_syntax_error, LOG_MAIN,
5730 "SMTP syntax error in \"%s\" %s %s",
3ee512ff 5731 string_printing(smtp_cmd_buffer), host_and_ident(TRUE),
059ec3d9
PH
5732 US"unrecognized command");
5733 incomplete_transaction_log(US"unrecognized command");
8f128379
PH
5734 smtp_notquit_exit(US"bad-commands", US"500",
5735 US"Too many unrecognized commands");
059ec3d9
PH
5736 done = 2;
5737 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
5738 "unrecognized commands (last was \"%s\")", host_and_ident(FALSE),
0ebc4d69 5739 string_printing(smtp_cmd_buffer));
059ec3d9
PH
5740 }
5741 else
5742 done = synprot_error(L_smtp_syntax_error, 500, NULL,
5743 US"unrecognized command");
5744 break;
5745 }
5746
5747 /* This label is used by goto's inside loops that want to break out to
5748 the end of the command-processing loop. */
5749
5750 COMMAND_LOOP:
5751 last_was_rej_mail = was_rej_mail; /* Remember some last commands for */
5752 last_was_rcpt = was_rcpt; /* protocol error handling */
5753 continue;
5754 }
5755
5756return done - 2; /* Convert yield values */
5757}
5758
e45a1c37
JH
5759/* vi: aw ai sw=2
5760*/
059ec3d9 5761/* End of smtp_in.c */