Logging: fix DKIM precis received log line element.
[exim.git] / src / src / smtp_in.c
<
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1/*************************************************
2* Exim - an Internet mail transport agent *
3*************************************************/
4
f9ba5e22 5/* Copyright (c) University of Cambridge 1995 - 2018 */
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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 },
69d8eed7 190 { "tls_auth", 0, TLS_AUTH_CMD, FALSE, FALSE },
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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
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253 ENV_MAIL_OPT_PRDR,
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
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271 { US"PRDR", ENV_MAIL_OPT_PRDR, FALSE },
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
059ec3d9 312/*************************************************
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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
f4630439
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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);
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362return FALSE;
363}
364
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365static BOOL
366check_sync(void)
367{
ecce6d9a 368if (!smtp_enforce_sync || !sender_host_address || sender_host_notsocket)
925ac8e4
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369 return TRUE;
370
371return wouldblock_reading();
372}
373
374
375/* If there's input waiting (and we're doing pipelineing) then we can pipeline
376a reponse with the one following. */
377
378static BOOL
379pipeline_response(void)
380{
381if ( !smtp_enforce_sync || !sender_host_address
382 || sender_host_notsocket || !pipelining_advertised)
383 return FALSE;
384
385return !wouldblock_reading();
386}
387
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388
389
390/*************************************************
391* Log incomplete transactions *
392*************************************************/
393
394/* This function is called after a transaction has been aborted by RSET, QUIT,
395connection drops or other errors. It logs the envelope information received
396so far in order to preserve address verification attempts.
397
398Argument: string to indicate what aborted the transaction
399Returns: nothing
400*/
401
402static void
403incomplete_transaction_log(uschar *what)
404{
405if (sender_address == NULL || /* No transaction in progress */
406 !LOGGING(smtp_incomplete_transaction))
407 return;
408
409/* Build list of recipients for logging */
410
411if (recipients_count > 0)
412 {
413 int i;
414 raw_recipients = store_get(recipients_count * sizeof(uschar *));
415 for (i = 0; i < recipients_count; i++)
416 raw_recipients[i] = recipients_list[i].address;
417 raw_recipients_count = recipients_count;
418 }
419
420log_write(L_smtp_incomplete_transaction, LOG_MAIN|LOG_SENDER|LOG_RECIPIENTS,
421 "%s incomplete transaction (%s)", host_and_ident(TRUE), what);
422}
423
424
425
426
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427/* Refill the buffer, and notify DKIM verification code.
428Return false for error or EOF.
429*/
430
431static BOOL
432smtp_refill(unsigned lim)
433{
434int rc, save_errno;
435if (!smtp_out) return FALSE;
436fflush(smtp_out);
437if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
438
ecce6d9a
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439/* Limit amount read, so non-message data is not fed to DKIM.
440Take care to not touch the safety NUL at the end of the buffer. */
0d81dabc 441
ecce6d9a 442rc = read(fileno(smtp_in), smtp_inbuffer, MIN(IN_BUFFER_SIZE-1, lim));
0d81dabc
JH
443save_errno = errno;
444alarm(0);
445if (rc <= 0)
446 {
447 /* Must put the error text in fixed store, because this might be during
448 header reading, where it releases unused store above the header. */
449 if (rc < 0)
450 {
451 smtp_had_error = save_errno;
452 smtp_read_error = string_copy_malloc(
453 string_sprintf(" (error: %s)", strerror(save_errno)));
454 }
455 else smtp_had_eof = 1;
456 return FALSE;
457 }
458#ifndef DISABLE_DKIM
459dkim_exim_verify_feed(smtp_inbuffer, rc);
460#endif
461smtp_inend = smtp_inbuffer + rc;
462smtp_inptr = smtp_inbuffer;
463return TRUE;
464}
465
f4630439 466/*************************************************
059ec3d9
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467* SMTP version of getc() *
468*************************************************/
469
470/* This gets the next byte from the SMTP input buffer. If the buffer is empty,
471it flushes the output, and refills the buffer, with a timeout. The signal
472handler is set appropriately by the calling function. This function is not used
4c04137d 473after a connection has negotiated itself into an TLS/SSL state.
059ec3d9 474
bd8fbe36 475Arguments: lim Maximum amount to read/buffer
059ec3d9
PH
476Returns: the next character or EOF
477*/
478
479int
bd8fbe36 480smtp_getc(unsigned lim)
059ec3d9
PH
481{
482if (smtp_inptr >= smtp_inend)
0d81dabc 483 if (!smtp_refill(lim))
059ec3d9 484 return EOF;
059ec3d9
PH
485return *smtp_inptr++;
486}
487
0d81dabc
JH
488uschar *
489smtp_getbuf(unsigned * len)
490{
491unsigned size;
492uschar * buf;
493
494if (smtp_inptr >= smtp_inend)
495 if (!smtp_refill(*len))
496 { *len = 0; return NULL; }
497
498if ((size = smtp_inend - smtp_inptr) > *len) size = *len;
499buf = smtp_inptr;
500smtp_inptr += size;
501*len = size;
502return buf;
503}
504
584e96c6
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505void
506smtp_get_cache(void)
507{
9960d1e5 508#ifndef DISABLE_DKIM
584e96c6
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509int n = smtp_inend - smtp_inptr;
510if (n > 0)
511 dkim_exim_verify_feed(smtp_inptr, n);
584e96c6 512#endif
9960d1e5 513}
059ec3d9
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514
515
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516/* Get a byte from the smtp input, in CHUNKING mode. Handle ack of the
517previous BDAT chunk and getting new ones when we run out. Uses the
518underlying smtp_getc or tls_getc both for that and for getting the
519(buffered) data byte. EOD signals (an expected) no further data.
520ERR signals a protocol error, and EOF a closed input stream.
521
522Called from read_bdat_smtp() in receive.c for the message body, but also
523by the headers read loop in receive_msg(); manipulates chunking_state
524to handle the BDAT command/response.
525Placed here due to the correlation with the above smtp_getc(), which it wraps,
526and also by the need to do smtp command/response handling.
527
bd8fbe36 528Arguments: lim (ignored)
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529Returns: the next character or ERR, EOD or EOF
530*/
531
532int
bd8fbe36 533bdat_getc(unsigned lim)
7e3ce68e
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534{
535uschar * user_msg = NULL;
536uschar * log_msg;
537
538for(;;)
539 {
79de4f37
JH
540#ifndef DISABLE_DKIM
541 BOOL dkim_save;
542#endif
543
bd8fbe36
JH
544 if (chunking_data_left > 0)
545 return lwr_receive_getc(chunking_data_left--);
7e3ce68e
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546
547 receive_getc = lwr_receive_getc;
0d81dabc 548 receive_getbuf = lwr_receive_getbuf;
7e3ce68e 549 receive_ungetc = lwr_receive_ungetc;
bd8fbe36 550#ifndef DISABLE_DKIM
79de4f37 551 dkim_save = dkim_collect_input;
bd8fbe36
JH
552 dkim_collect_input = FALSE;
553#endif
7e3ce68e 554
f4630439
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555 /* Unless PIPELINING was offered, there should be no next command
556 until after we ack that chunk */
557
558 if (!pipelining_advertised && !check_sync())
559 {
40525d07
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560 unsigned n = smtp_inend - smtp_inptr;
561 if (n > 32) n = 32;
562
f4630439
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563 incomplete_transaction_log(US"sync failure");
564 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol synchronization error "
565 "(next input sent too soon: pipelining was not advertised): "
9e0ed81f 566 "rejected \"%s\" %s next input=\"%s\"%s",
f4630439 567 smtp_cmd_buffer, host_and_ident(TRUE),
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JH
568 string_printing(string_copyn(smtp_inptr, n)),
569 smtp_inend - smtp_inptr > n ? "..." : "");
570 (void) synprot_error(L_smtp_protocol_error, 554, NULL,
571 US"SMTP synchronization error");
f4630439
JH
572 goto repeat_until_rset;
573 }
574
7e3ce68e
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575 /* If not the last, ack the received chunk. The last response is delayed
576 until after the data ACL decides on it */
7e3ce68e
JH
577
578 if (chunking_state == CHUNKING_LAST)
584e96c6
JH
579 {
580#ifndef DISABLE_DKIM
e983e85a 581 dkim_exim_verify_feed(NULL, 0); /* notify EOD */
584e96c6 582#endif
7e3ce68e 583 return EOD;
584e96c6 584 }
7e3ce68e 585
925ac8e4 586 smtp_printf("250 %u byte chunk received\r\n", FALSE, chunking_datasize);
bd8fbe36
JH
587 chunking_state = CHUNKING_OFFERED;
588 DEBUG(D_receive) debug_printf("chunking state %d\n", (int)chunking_state);
7e3ce68e
JH
589
590 /* Expect another BDAT cmd from input. RFC 3030 says nothing about
591 QUIT, RSET or NOOP but handling them seems obvious */
592
593next_cmd:
bd8fbe36 594 switch(smtp_read_command(TRUE, 1))
7e3ce68e
JH
595 {
596 default:
597 (void) synprot_error(L_smtp_protocol_error, 503, NULL,
598 US"only BDAT permissible after non-LAST BDAT");
599
600 repeat_until_rset:
bd8fbe36 601 switch(smtp_read_command(TRUE, 1))
7e3ce68e
JH
602 {
603 case QUIT_CMD: smtp_quit_handler(&user_msg, &log_msg); /*FALLTHROUGH */
604 case EOF_CMD: return EOF;
605 case RSET_CMD: smtp_rset_handler(); return ERR;
606 default: if (synprot_error(L_smtp_protocol_error, 503, NULL,
607 US"only RSET accepted now") > 0)
608 return EOF;
609 goto repeat_until_rset;
610 }
611
612 case QUIT_CMD:
613 smtp_quit_handler(&user_msg, &log_msg);
614 /*FALLTHROUGH*/
615 case EOF_CMD:
616 return EOF;
617
618 case RSET_CMD:
619 smtp_rset_handler();
620 return ERR;
621
622 case NOOP_CMD:
623 HAD(SCH_NOOP);
925ac8e4 624 smtp_printf("250 OK\r\n", FALSE);
7e3ce68e
JH
625 goto next_cmd;
626
627 case BDAT_CMD:
628 {
629 int n;
630
631 if (sscanf(CS smtp_cmd_data, "%u %n", &chunking_datasize, &n) < 1)
632 {
633 (void) synprot_error(L_smtp_protocol_error, 501, NULL,
634 US"missing size for BDAT command");
635 return ERR;
636 }
637 chunking_state = strcmpic(smtp_cmd_data+n, US"LAST") == 0
638 ? CHUNKING_LAST : CHUNKING_ACTIVE;
639 chunking_data_left = chunking_datasize;
bd8fbe36
JH
640 DEBUG(D_receive) debug_printf("chunking state %d, %d bytes\n",
641 (int)chunking_state, chunking_data_left);
7e3ce68e
JH
642
643 if (chunking_datasize == 0)
644 if (chunking_state == CHUNKING_LAST)
645 return EOD;
646 else
647 {
648 (void) synprot_error(L_smtp_protocol_error, 504, NULL,
649 US"zero size for BDAT command");
650 goto repeat_until_rset;
651 }
652
653 receive_getc = bdat_getc;
8b77d27a 654 receive_getbuf = bdat_getbuf; /* r~getbuf is never actually used */
7e3ce68e 655 receive_ungetc = bdat_ungetc;
bd8fbe36 656#ifndef DISABLE_DKIM
79de4f37 657 dkim_collect_input = dkim_save;
bd8fbe36 658#endif
7e3ce68e
JH
659 break; /* to top of main loop */
660 }
661 }
662 }
663}
664
0d81dabc
JH
665uschar *
666bdat_getbuf(unsigned * len)
667{
668uschar * buf;
669
670if (chunking_data_left <= 0)
671 { *len = 0; return NULL; }
672
673if (*len > chunking_data_left) *len = chunking_data_left;
674buf = lwr_receive_getbuf(len); /* Either smtp_getbuf or tls_getbuf */
675chunking_data_left -= *len;
676return buf;
677}
678
1ebe15c3 679void
45bd315d
JH
680bdat_flush_data(void)
681{
e99a3a6c 682while (chunking_data_left)
db57e575 683 {
e99a3a6c 684 unsigned n = chunking_data_left;
8b77d27a 685 if (!bdat_getbuf(&n)) break;
db57e575 686 }
45bd315d
JH
687
688receive_getc = lwr_receive_getc;
0d81dabc 689receive_getbuf = lwr_receive_getbuf;
45bd315d
JH
690receive_ungetc = lwr_receive_ungetc;
691
692if (chunking_state != CHUNKING_LAST)
bd8fbe36 693 {
45bd315d 694 chunking_state = CHUNKING_OFFERED;
bd8fbe36
JH
695 DEBUG(D_receive) debug_printf("chunking state %d\n", (int)chunking_state);
696 }
45bd315d
JH
697}
698
7e3ce68e
JH
699
700
701
059ec3d9
PH
702/*************************************************
703* SMTP version of ungetc() *
704*************************************************/
705
706/* Puts a character back in the input buffer. Only ever
707called once.
708
709Arguments:
710 ch the character
711
712Returns: the character
713*/
714
715int
716smtp_ungetc(int ch)
717{
7e3ce68e 718*--smtp_inptr = ch;
059ec3d9
PH
719return ch;
720}
721
722
7e3ce68e
JH
723int
724bdat_ungetc(int ch)
725{
726chunking_data_left++;
727return lwr_receive_ungetc(ch);
728}
729
059ec3d9
PH
730
731
732/*************************************************
733* SMTP version of feof() *
734*************************************************/
735
736/* Tests for a previous EOF
737
738Arguments: none
739Returns: non-zero if the eof flag is set
740*/
741
742int
743smtp_feof(void)
744{
745return smtp_had_eof;
746}
747
748
749
750
751/*************************************************
752* SMTP version of ferror() *
753*************************************************/
754
755/* Tests for a previous read error, and returns with errno
756restored to what it was when the error was detected.
757
758Arguments: none
759Returns: non-zero if the error flag is set
760*/
761
762int
763smtp_ferror(void)
764{
765errno = smtp_had_error;
766return smtp_had_error;
767}
768
769
770
58eb016e
PH
771/*************************************************
772* Test for characters in the SMTP buffer *
773*************************************************/
774
775/* Used at the end of a message
776
777Arguments: none
778Returns: TRUE/FALSE
779*/
780
781BOOL
782smtp_buffered(void)
783{
784return smtp_inptr < smtp_inend;
785}
786
787
059ec3d9
PH
788
789/*************************************************
790* Write formatted string to SMTP channel *
791*************************************************/
792
793/* This is a separate function so that we don't have to repeat everything for
794TLS support or debugging. It is global so that the daemon and the
795authentication functions can use it. It does not return any error indication,
796because major problems such as dropped connections won't show up till an output
797flush for non-TLS connections. The smtp_fflush() function is available for
798checking that: for convenience, TLS output errors are remembered here so that
799they are also picked up later by smtp_fflush().
800
801Arguments:
802 format format string
925ac8e4 803 more further data expected
059ec3d9
PH
804 ... optional arguments
805
806Returns: nothing
807*/
808
809void
925ac8e4 810smtp_printf(const char *format, BOOL more, ...)
059ec3d9
PH
811{
812va_list ap;
813
925ac8e4
JH
814va_start(ap, more);
815smtp_vprintf(format, more, ap);
ce552449
NM
816va_end(ap);
817}
818
819/* This is split off so that verify.c:respond_printf() can, in effect, call
820smtp_printf(), bearing in mind that in C a vararg function can't directly
fb08281f 821call another vararg function, only a function which accepts a va_list. */
ce552449
NM
822
823void
925ac8e4 824smtp_vprintf(const char *format, BOOL more, va_list ap)
ce552449 825{
fb08281f
DW
826BOOL yield;
827
828yield = string_vformat(big_buffer, big_buffer_size, format, ap);
ce552449 829
059ec3d9
PH
830DEBUG(D_receive)
831 {
fb08281f
DW
832 void *reset_point = store_get(0);
833 uschar *msg_copy, *cr, *end;
834 msg_copy = string_copy(big_buffer);
835 end = msg_copy + Ustrlen(msg_copy);
836 while ((cr = Ustrchr(msg_copy, '\r')) != NULL) /* lose CRs */
837 memmove(cr, cr + 1, (end--) - cr);
838 debug_printf("SMTP>> %s", msg_copy);
839 store_reset(reset_point);
059ec3d9
PH
840 }
841
fb08281f 842if (!yield)
2679d413
PH
843 {
844 log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_printf()");
845 smtp_closedown(US"Unexpected error");
9bfb7e1b 846 exim_exit(EXIT_FAILURE, NULL);
2679d413 847 }
2679d413
PH
848
849/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
850have had the same. Note: this code is also present in smtp_respond(). It would
851be tidier to have it only in one place, but when it was added, it was easier to
852do it that way, so as not to have to mess with the code for the RCPT command,
853which sometimes uses smtp_printf() and sometimes smtp_respond(). */
854
855if (rcpt_in_progress)
856 {
857 if (rcpt_smtp_response == NULL)
858 rcpt_smtp_response = string_copy(big_buffer);
859 else if (rcpt_smtp_response_same &&
860 Ustrcmp(rcpt_smtp_response, big_buffer) != 0)
861 rcpt_smtp_response_same = FALSE;
862 rcpt_in_progress = FALSE;
863 }
059ec3d9 864
2679d413 865/* Now write the string */
059ec3d9
PH
866
867#ifdef SUPPORT_TLS
817d9f57 868if (tls_in.active >= 0)
059ec3d9 869 {
925ac8e4 870 if (tls_write(TRUE, big_buffer, Ustrlen(big_buffer), more) < 0)
817d9f57 871 smtp_write_error = -1;
059ec3d9
PH
872 }
873else
874#endif
875
2679d413 876if (fprintf(smtp_out, "%s", big_buffer) < 0) smtp_write_error = -1;
059ec3d9
PH
877}
878
879
880
881/*************************************************
882* Flush SMTP out and check for error *
883*************************************************/
884
885/* This function isn't currently used within Exim (it detects errors when it
886tries to read the next SMTP input), but is available for use in local_scan().
887For non-TLS connections, it flushes the output and checks for errors. For
888TLS-connections, it checks for a previously-detected TLS write error.
889
890Arguments: none
891Returns: 0 for no error; -1 after an error
892*/
893
894int
895smtp_fflush(void)
896{
817d9f57 897if (tls_in.active < 0 && fflush(smtp_out) != 0) smtp_write_error = -1;
059ec3d9
PH
898return smtp_write_error;
899}
900
901
902
903/*************************************************
904* SMTP command read timeout *
905*************************************************/
906
907/* Signal handler for timing out incoming SMTP commands. This attempts to
908finish off tidily.
909
910Argument: signal number (SIGALRM)
911Returns: nothing
912*/
913
914static void
915command_timeout_handler(int sig)
916{
917sig = sig; /* Keep picky compilers happy */
918log_write(L_lost_incoming_connection,
919 LOG_MAIN, "SMTP command timeout on%s connection from %s",
817d9f57 920 (tls_in.active >= 0)? " TLS" : "",
059ec3d9
PH
921 host_and_ident(FALSE));
922if (smtp_batched_input)
923 moan_smtp_batch(NULL, "421 SMTP command timeout"); /* Does not return */
8f128379
PH
924smtp_notquit_exit(US"command-timeout", US"421",
925 US"%s: SMTP command timeout - closing connection", smtp_active_hostname);
9bfb7e1b 926exim_exit(EXIT_FAILURE, US"receiving");
059ec3d9
PH
927}
928
929
930
931/*************************************************
932* SIGTERM received *
933*************************************************/
934
935/* Signal handler for handling SIGTERM. Again, try to finish tidily.
936
937Argument: signal number (SIGTERM)
938Returns: nothing
939*/
940
941static void
942command_sigterm_handler(int sig)
943{
944sig = sig; /* Keep picky compilers happy */
945log_write(0, LOG_MAIN, "%s closed after SIGTERM", smtp_get_connection_info());
946if (smtp_batched_input)
947 moan_smtp_batch(NULL, "421 SIGTERM received"); /* Does not return */
8f128379
PH
948smtp_notquit_exit(US"signal-exit", US"421",
949 US"%s: Service not available - closing connection", smtp_active_hostname);
9bfb7e1b 950exim_exit(EXIT_FAILURE, US"receiving");
059ec3d9
PH
951}
952
953
954
a14e5636 955
cee5f132 956#ifdef SUPPORT_PROXY
a3c86431 957/*************************************************
a3bddaa8
TL
958* Restore socket timeout to previous value *
959*************************************************/
960/* If the previous value was successfully retrieved, restore
961it before returning control to the non-proxy routines
962
963Arguments: fd - File descriptor for input
964 get_ok - Successfully retrieved previous values
965 tvtmp - Time struct with previous values
966 vslen - Length of time struct
967Returns: none
968*/
969static void
f267271d 970restore_socket_timeout(int fd, int get_ok, struct timeval * tvtmp, socklen_t vslen)
a3bddaa8
TL
971{
972if (get_ok == 0)
f267271d 973 (void) setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS tvtmp, vslen);
a3bddaa8
TL
974}
975
976/*************************************************
a3c86431
TL
977* Check if host is required proxy host *
978*************************************************/
979/* The function determines if inbound host will be a regular smtp host
1811cb4c
JH
980or if it is configured that it must use Proxy Protocol. A local
981connection cannot.
a3c86431
TL
982
983Arguments: none
984Returns: bool
985*/
986
987static BOOL
988check_proxy_protocol_host()
989{
990int rc;
a3c86431 991
1811cb4c
JH
992if ( sender_host_address
993 && (rc = verify_check_this_host(CUSS &hosts_proxy, NULL, NULL,
994 sender_host_address, NULL)) == OK)
a3c86431
TL
995 {
996 DEBUG(D_receive)
997 debug_printf("Detected proxy protocol configured host\n");
998 proxy_session = TRUE;
999 }
1000return proxy_session;
1001}
1002
1003
1004/*************************************************
3f251b3c
PP
1005* Read data until newline or end of buffer *
1006*************************************************/
1007/* While SMTP is server-speaks-first, TLS is client-speaks-first, so we can't
1008read an entire buffer and assume there will be nothing past a proxy protocol
1009header. Our approach normally is to use stdio, but again that relies upon
1010"STARTTLS\r\n" and a server response before the client starts TLS handshake, or
1011reading _nothing_ before client TLS handshake. So we don't want to use the
1012usual buffering reads which may read enough to block TLS starting.
1013
1014So unfortunately we're down to "read one byte at a time, with a syscall each,
1015and expect a little overhead", for all proxy-opened connections which are v1,
1016just to handle the TLS-on-connect case. Since SSL functions wrap the
1017underlying fd, we can't assume that we can feed them any already-read content.
1018
1019We need to know where to read to, the max capacity, and we'll read until we
1020get a CR and one more character. Let the caller scream if it's CR+!LF.
1021
1022Return the amount read.
1023*/
1024
1025static int
da88acae 1026swallow_until_crlf(int fd, uschar *base, int already, int capacity)
3f251b3c 1027{
2c0f3ea1
JH
1028uschar *to = base + already;
1029uschar *cr;
1030int have = 0;
1031int ret;
1032int last = 0;
1033
1034/* For "PROXY UNKNOWN\r\n" we, at time of writing, expect to have read
1035up through the \r; for the _normal_ case, we haven't yet seen the \r. */
da88acae 1036
2c0f3ea1
JH
1037cr = memchr(base, '\r', already);
1038if (cr != NULL)
1039 {
1040 if ((cr - base) < already - 1)
da88acae 1041 {
2c0f3ea1
JH
1042 /* \r and presumed \n already within what we have; probably not
1043 actually proxy protocol, but abort cleanly. */
1044 return 0;
da88acae 1045 }
2c0f3ea1
JH
1046 /* \r is last character read, just need one more. */
1047 last = 1;
1048 }
1049
1050while (capacity > 0)
1051 {
1052 do { ret = recv(fd, to, 1, 0); } while (ret == -1 && errno == EINTR);
1053 if (ret == -1)
1054 return -1;
1055 have++;
1056 if (last)
1057 return have;
1058 if (*to == '\r')
1059 last = 1;
1060 capacity--;
1061 to++;
1062 }
1063
1064/* reached end without having room for a final newline, abort */
1065errno = EOVERFLOW;
1066return -1;
3f251b3c
PP
1067}
1068
1069/*************************************************
a3c86431
TL
1070* Setup host for proxy protocol *
1071*************************************************/
1072/* The function configures the connection based on a header from the
1073inbound host to use Proxy Protocol. The specification is very exact
1074so exit with an error if do not find the exact required pieces. This
1075includes an incorrect number of spaces separating args.
1076
1077Arguments: none
f267271d 1078Returns: Boolean success
a3c86431
TL
1079*/
1080
1811cb4c 1081static void
a3c86431
TL
1082setup_proxy_protocol_host()
1083{
1084union {
1085 struct {
1086 uschar line[108];
1087 } v1;
1088 struct {
1089 uschar sig[12];
36719342
TL
1090 uint8_t ver_cmd;
1091 uint8_t fam;
1092 uint16_t len;
a3c86431
TL
1093 union {
1094 struct { /* TCP/UDP over IPv4, len = 12 */
1095 uint32_t src_addr;
1096 uint32_t dst_addr;
1097 uint16_t src_port;
1098 uint16_t dst_port;
1099 } ip4;
1100 struct { /* TCP/UDP over IPv6, len = 36 */
1101 uint8_t src_addr[16];
1102 uint8_t dst_addr[16];
1103 uint16_t src_port;
1104 uint16_t dst_port;
1105 } ip6;
1106 struct { /* AF_UNIX sockets, len = 216 */
1107 uschar src_addr[108];
1108 uschar dst_addr[108];
1109 } unx;
1110 } addr;
1111 } v2;
1112} hdr;
1113
eb57651e
TL
1114/* Temp variables used in PPv2 address:port parsing */
1115uint16_t tmpport;
1116char tmpip[INET_ADDRSTRLEN];
1117struct sockaddr_in tmpaddr;
1118char tmpip6[INET6_ADDRSTRLEN];
1119struct sockaddr_in6 tmpaddr6;
1120
da88acae
PP
1121/* We can't read "all data until end" because while SMTP is
1122server-speaks-first, the TLS handshake is client-speaks-first, so for
1123TLS-on-connect ports the proxy protocol header will usually be immediately
1124followed by a TLS handshake, and with N TLS libraries, we can't reliably
1125reinject data for reading by those. So instead we first read "enough to be
1126safely read within the header, and figure out how much more to read".
1127For v1 we will later read to the end-of-line, for v2 we will read based upon
1128the stated length.
1129
1130The v2 sig is 12 octets, and another 4 gets us the length, so we know how much
1131data is needed total. For v1, where the line looks like:
1132PROXY TCPn L3src L3dest SrcPort DestPort \r\n
1133
1134However, for v1 there's also `PROXY UNKNOWN\r\n` which is only 15 octets.
1135We seem to support that. So, if we read 14 octets then we can tell if we're
1136v2 or v1. If we're v1, we can continue reading as normal.
1137
1138If we're v2, we can't slurp up the entire header. We need the length in the
113915th & 16th octets, then to read everything after that.
1140
1141So to safely handle v1 and v2, with client-sent-first supported correctly,
1142we have to do a minimum of 3 read calls, not 1. Eww.
1143*/
1144
1145#define PROXY_INITIAL_READ 14
1146#define PROXY_V2_HEADER_SIZE 16
1147#if PROXY_INITIAL_READ > PROXY_V2_HEADER_SIZE
1148# error Code bug in sizes of data to read for proxy usage
1149#endif
1150
eb57651e 1151int get_ok = 0;
f267271d
JH
1152int size, ret;
1153int fd = fileno(smtp_in);
36719342 1154const char v2sig[12] = "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A";
9e7e0f6a 1155uschar * iptype; /* To display debug info */
a3c86431 1156struct timeval tv;
a3bddaa8 1157struct timeval tvtmp;
f267271d 1158socklen_t vslen = sizeof(struct timeval);
1811cb4c 1159BOOL yield = FALSE;
a3c86431 1160
a3bddaa8 1161/* Save current socket timeout values */
f267271d 1162get_ok = getsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS &tvtmp, &vslen);
a3bddaa8 1163
a3c86431
TL
1164/* Proxy Protocol host must send header within a short time
1165(default 3 seconds) or it's considered invalid */
1166tv.tv_sec = PROXY_NEGOTIATION_TIMEOUT_SEC;
1167tv.tv_usec = PROXY_NEGOTIATION_TIMEOUT_USEC;
f267271d 1168if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS &tv, sizeof(tv)) < 0)
1811cb4c 1169 goto bad;
a3bddaa8 1170
a3c86431
TL
1171do
1172 {
eb57651e 1173 /* The inbound host was declared to be a Proxy Protocol host, so
2c0f3ea1
JH
1174 don't do a PEEK into the data, actually slurp up enough to be
1175 "safe". Can't take it all because TLS-on-connect clients follow
1176 immediately with TLS handshake. */
3f251b3c 1177 ret = recv(fd, &hdr, PROXY_INITIAL_READ, 0);
a3c86431
TL
1178 }
1179 while (ret == -1 && errno == EINTR);
1180
1181if (ret == -1)
f267271d 1182 goto proxyfail;
a3c86431 1183
da88acae
PP
1184/* For v2, handle reading the length, and then the rest. */
1185if ((ret == PROXY_INITIAL_READ) && (memcmp(&hdr.v2, v2sig, sizeof(v2sig)) == 0))
a3c86431 1186 {
da88acae
PP
1187 int retmore;
1188 uint8_t ver;
1189
1190 /* First get the length fields. */
1191 do
1192 {
1193 retmore = recv(fd, (uschar*)&hdr + ret, PROXY_V2_HEADER_SIZE - PROXY_INITIAL_READ, 0);
1194 } while (retmore == -1 && errno == EINTR);
1195 if (retmore == -1)
3f251b3c 1196 goto proxyfail;
da88acae 1197 ret += retmore;
3f251b3c
PP
1198
1199 ver = (hdr.v2.ver_cmd & 0xf0) >> 4;
36719342
TL
1200
1201 /* May 2014: haproxy combined the version and command into one byte to
2c0f3ea1
JH
1202 allow two full bytes for the length field in order to proxy SSL
1203 connections. SSL Proxy is not supported in this version of Exim, but
1204 must still separate values here. */
36719342
TL
1205
1206 if (ver != 0x02)
1207 {
1208 DEBUG(D_receive) debug_printf("Invalid Proxy Protocol version: %d\n", ver);
1209 goto proxyfail;
1210 }
da88acae 1211
36719342 1212 /* The v2 header will always be 16 bytes per the spec. */
5d036699 1213 size = 16 + ntohs(hdr.v2.len);
da88acae
PP
1214 DEBUG(D_receive) debug_printf("Detected PROXYv2 header, size %d (limit %d)\n",
1215 size, (int)sizeof(hdr));
1216
1217 /* We should now have 16 octets (PROXY_V2_HEADER_SIZE), and we know the total
1218 amount that we need. Double-check that the size is not unreasonable, then
1219 get the rest. */
1220 if (size > sizeof(hdr))
a3c86431 1221 {
da88acae 1222 DEBUG(D_receive) debug_printf("PROXYv2 header size unreasonably large; security attack?\n");
a3c86431
TL
1223 goto proxyfail;
1224 }
da88acae
PP
1225
1226 do
1227 {
1228 do
1229 {
1230 retmore = recv(fd, (uschar*)&hdr + ret, size-ret, 0);
1231 } while (retmore == -1 && errno == EINTR);
1232 if (retmore == -1)
1233 goto proxyfail;
1234 ret += retmore;
1235 DEBUG(D_receive) debug_printf("PROXYv2: have %d/%d required octets\n", ret, size);
1236 } while (ret < size);
1237
1238 } /* end scope for getting rest of data for v2 */
1239
1240/* At this point: if PROXYv2, we've read the exact size required for all data;
1241if PROXYv1 then we've read "less than required for any valid line" and should
1242read the rest". */
1243
1244if (ret >= 16 && memcmp(&hdr.v2, v2sig, 12) == 0)
1245 {
1246 uint8_t cmd = (hdr.v2.ver_cmd & 0x0f);
1247
36719342 1248 switch (cmd)
a3c86431
TL
1249 {
1250 case 0x01: /* PROXY command */
1251 switch (hdr.v2.fam)
1252 {
eb57651e
TL
1253 case 0x11: /* TCPv4 address type */
1254 iptype = US"IPv4";
1255 tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.src_addr;
5d036699
JH
1256 inet_ntop(AF_INET, &tmpaddr.sin_addr, CS &tmpip, sizeof(tmpip));
1257 if (!string_is_ip_address(US tmpip, NULL))
eb57651e
TL
1258 {
1259 DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
f267271d 1260 goto proxyfail;
eb57651e 1261 }
e6d2a989 1262 proxy_local_address = sender_host_address;
eb57651e
TL
1263 sender_host_address = string_copy(US tmpip);
1264 tmpport = ntohs(hdr.v2.addr.ip4.src_port);
e6d2a989 1265 proxy_local_port = sender_host_port;
eb57651e
TL
1266 sender_host_port = tmpport;
1267 /* Save dest ip/port */
1268 tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.dst_addr;
5d036699
JH
1269 inet_ntop(AF_INET, &tmpaddr.sin_addr, CS &tmpip, sizeof(tmpip));
1270 if (!string_is_ip_address(US tmpip, NULL))
eb57651e
TL
1271 {
1272 DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype);
f267271d 1273 goto proxyfail;
eb57651e 1274 }
7a2fa0bc 1275 proxy_external_address = string_copy(US tmpip);
eb57651e 1276 tmpport = ntohs(hdr.v2.addr.ip4.dst_port);
7a2fa0bc 1277 proxy_external_port = tmpport;
a3c86431 1278 goto done;
eb57651e
TL
1279 case 0x21: /* TCPv6 address type */
1280 iptype = US"IPv6";
1281 memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.src_addr, 16);
5d036699
JH
1282 inet_ntop(AF_INET6, &tmpaddr6.sin6_addr, CS &tmpip6, sizeof(tmpip6));
1283 if (!string_is_ip_address(US tmpip6, NULL))
eb57651e
TL
1284 {
1285 DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
f267271d 1286 goto proxyfail;
eb57651e 1287 }
e6d2a989 1288 proxy_local_address = sender_host_address;
eb57651e
TL
1289 sender_host_address = string_copy(US tmpip6);
1290 tmpport = ntohs(hdr.v2.addr.ip6.src_port);
e6d2a989 1291 proxy_local_port = sender_host_port;
eb57651e
TL
1292 sender_host_port = tmpport;
1293 /* Save dest ip/port */
1294 memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.dst_addr, 16);
5d036699
JH
1295 inet_ntop(AF_INET6, &tmpaddr6.sin6_addr, CS &tmpip6, sizeof(tmpip6));
1296 if (!string_is_ip_address(US tmpip6, NULL))
eb57651e
TL
1297 {
1298 DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype);
f267271d 1299 goto proxyfail;
eb57651e 1300 }
7a2fa0bc 1301 proxy_external_address = string_copy(US tmpip6);
eb57651e 1302 tmpport = ntohs(hdr.v2.addr.ip6.dst_port);
7a2fa0bc 1303 proxy_external_port = tmpport;
a3c86431 1304 goto done;
eb57651e
TL
1305 default:
1306 DEBUG(D_receive)
1307 debug_printf("Unsupported PROXYv2 connection type: 0x%02x\n",
1308 hdr.v2.fam);
1309 goto proxyfail;
a3c86431
TL
1310 }
1311 /* Unsupported protocol, keep local connection address */
1312 break;
1313 case 0x00: /* LOCAL command */
1314 /* Keep local connection address for LOCAL */
9e7e0f6a 1315 iptype = US"local";
a3c86431
TL
1316 break;
1317 default:
eb57651e 1318 DEBUG(D_receive)
36719342 1319 debug_printf("Unsupported PROXYv2 command: 0x%x\n", cmd);
a3c86431
TL
1320 goto proxyfail;
1321 }
1322 }
5d036699 1323else if (ret >= 8 && memcmp(hdr.v1.line, "PROXY", 5) == 0)
a3c86431 1324 {
3f251b3c
PP
1325 uschar *p;
1326 uschar *end;
a3c86431
TL
1327 uschar *sp; /* Utility variables follow */
1328 int tmp_port;
3f251b3c 1329 int r2;
a3c86431
TL
1330 char *endc;
1331
3f251b3c 1332 /* get the rest of the line */
da88acae 1333 r2 = swallow_until_crlf(fd, (uschar*)&hdr, ret, sizeof(hdr)-ret);
3f251b3c
PP
1334 if (r2 == -1)
1335 goto proxyfail;
1336 ret += r2;
1337
1338 p = string_copy(hdr.v1.line);
1339 end = memchr(p, '\r', ret - 1);
1340
da88acae 1341 if (!end || (end == (uschar*)&hdr + ret) || end[1] != '\n')
a3c86431
TL
1342 {
1343 DEBUG(D_receive) debug_printf("Partial or invalid PROXY header\n");
1344 goto proxyfail;
1345 }
1346 *end = '\0'; /* Terminate the string */
a5d4db40 1347 size = end + 2 - p; /* Skip header + CRLF */
a3c86431 1348 DEBUG(D_receive) debug_printf("Detected PROXYv1 header\n");
3f251b3c 1349 DEBUG(D_receive) debug_printf("Bytes read not within PROXY header: %d\n", ret - size);
a3c86431 1350 /* Step through the string looking for the required fields. Ensure
2c0f3ea1 1351 strict adherence to required formatting, exit for any error. */
a3c86431
TL
1352 p += 5;
1353 if (!isspace(*(p++)))
1354 {
1355 DEBUG(D_receive) debug_printf("Missing space after PROXY command\n");
1356 goto proxyfail;
1357 }
1358 if (!Ustrncmp(p, CCS"TCP4", 4))
1359 iptype = US"IPv4";
1360 else if (!Ustrncmp(p,CCS"TCP6", 4))
1361 iptype = US"IPv6";
1362 else if (!Ustrncmp(p,CCS"UNKNOWN", 7))
1363 {
1364 iptype = US"Unknown";
1365 goto done;
1366 }
1367 else
1368 {
1369 DEBUG(D_receive) debug_printf("Invalid TCP type\n");
1370 goto proxyfail;
1371 }
1372
1373 p += Ustrlen(iptype);
1374 if (!isspace(*(p++)))
1375 {
1376 DEBUG(D_receive) debug_printf("Missing space after TCP4/6 command\n");
1377 goto proxyfail;
1378 }
1379 /* Find the end of the arg */
1380 if ((sp = Ustrchr(p, ' ')) == NULL)
1381 {
1382 DEBUG(D_receive)
1383 debug_printf("Did not find proxied src %s\n", iptype);
1384 goto proxyfail;
1385 }
1386 *sp = '\0';
5d036699 1387 if(!string_is_ip_address(p, NULL))
a3c86431
TL
1388 {
1389 DEBUG(D_receive)
1390 debug_printf("Proxied src arg is not an %s address\n", iptype);
1391 goto proxyfail;
1392 }
e6d2a989 1393 proxy_local_address = sender_host_address;
a3c86431
TL
1394 sender_host_address = p;
1395 p = sp + 1;
1396 if ((sp = Ustrchr(p, ' ')) == NULL)
1397 {
1398 DEBUG(D_receive)
1399 debug_printf("Did not find proxy dest %s\n", iptype);
1400 goto proxyfail;
1401 }
1402 *sp = '\0';
5d036699 1403 if(!string_is_ip_address(p, NULL))
a3c86431
TL
1404 {
1405 DEBUG(D_receive)
1406 debug_printf("Proxy dest arg is not an %s address\n", iptype);
1407 goto proxyfail;
1408 }
7a2fa0bc 1409 proxy_external_address = p;
a3c86431
TL
1410 p = sp + 1;
1411 if ((sp = Ustrchr(p, ' ')) == NULL)
1412 {
1413 DEBUG(D_receive) debug_printf("Did not find proxied src port\n");
1414 goto proxyfail;
1415 }
1416 *sp = '\0';
5d036699 1417 tmp_port = strtol(CCS p, &endc, 10);
a3c86431
TL
1418 if (*endc || tmp_port == 0)
1419 {
1420 DEBUG(D_receive)
1421 debug_printf("Proxied src port '%s' not an integer\n", p);
1422 goto proxyfail;
1423 }
e6d2a989 1424 proxy_local_port = sender_host_port;
a3c86431
TL
1425 sender_host_port = tmp_port;
1426 p = sp + 1;
1427 if ((sp = Ustrchr(p, '\0')) == NULL)
1428 {
1429 DEBUG(D_receive) debug_printf("Did not find proxy dest port\n");
1430 goto proxyfail;
1431 }
5d036699 1432 tmp_port = strtol(CCS p, &endc, 10);
a3c86431
TL
1433 if (*endc || tmp_port == 0)
1434 {
1435 DEBUG(D_receive)
1436 debug_printf("Proxy dest port '%s' not an integer\n", p);
1437 goto proxyfail;
1438 }
7a2fa0bc 1439 proxy_external_port = tmp_port;
a3c86431 1440 /* Already checked for /r /n above. Good V1 header received. */
a3c86431
TL
1441 }
1442else
1443 {
1444 /* Wrong protocol */
eb57651e 1445 DEBUG(D_receive) debug_printf("Invalid proxy protocol version negotiation\n");
da88acae 1446 (void) swallow_until_crlf(fd, (uschar*)&hdr, ret, sizeof(hdr)-ret);
a3c86431
TL
1447 goto proxyfail;
1448 }
1449
1811cb4c
JH
1450done:
1451 DEBUG(D_receive)
1452 debug_printf("Valid %s sender from Proxy Protocol header\n", iptype);
1453 yield = proxy_session;
1454
1455/* Don't flush any potential buffer contents. Any input on proxyfail
1456should cause a synchronization failure */
1457
a3c86431 1458proxyfail:
1811cb4c 1459 restore_socket_timeout(fd, get_ok, &tvtmp, vslen);
a3c86431 1460
1811cb4c
JH
1461bad:
1462 if (yield)
1463 {
1464 sender_host_name = NULL;
1465 (void) host_name_lookup();
1466 host_build_sender_fullhost();
1467 }
1468 else
1469 {
1470 proxy_session_failed = TRUE;
1471 DEBUG(D_receive)
1472 debug_printf("Failure to extract proxied host, only QUIT allowed\n");
1473 }
1474
1475return;
a3c86431
TL
1476}
1477#endif
1478
059ec3d9
PH
1479/*************************************************
1480* Read one command line *
1481*************************************************/
1482
1483/* Strictly, SMTP commands coming over the net are supposed to end with CRLF.
1484There are sites that don't do this, and in any case internal SMTP probably
1485should check only for LF. Consequently, we check here for LF only. The line
1486ends up with [CR]LF removed from its end. If we get an overlong line, treat as
3ee512ff
PH
1487an unknown command. The command is read into the global smtp_cmd_buffer so that
1488it is available via $smtp_command.
059ec3d9
PH
1489
1490The character reading routine sets up a timeout for each block actually read
1491from the input (which may contain more than one command). We set up a special
1492signal handler that closes down the session on a timeout. Control does not
1493return when it runs.
1494
1495Arguments:
bd8fbe36
JH
1496 check_sync if TRUE, check synchronization rules if global option is TRUE
1497 buffer_lim maximum to buffer in lower layer
059ec3d9
PH
1498
1499Returns: a code identifying the command (enumerated above)
1500*/
1501
1502static int
bd8fbe36 1503smtp_read_command(BOOL check_sync, unsigned buffer_lim)
059ec3d9
PH
1504{
1505int c;
1506int ptr = 0;
1507smtp_cmd_list *p;
1508BOOL hadnull = FALSE;
1509
1510os_non_restarting_signal(SIGALRM, command_timeout_handler);
1511
bd8fbe36 1512while ((c = (receive_getc)(buffer_lim)) != '\n' && c != EOF)
059ec3d9 1513 {
bd8fbe36 1514 if (ptr >= SMTP_CMD_BUFFER_SIZE)
059ec3d9
PH
1515 {
1516 os_non_restarting_signal(SIGALRM, sigalrm_handler);
1517 return OTHER_CMD;
1518 }
1519 if (c == 0)
1520 {
1521 hadnull = TRUE;
1522 c = '?';
1523 }
3ee512ff 1524 smtp_cmd_buffer[ptr++] = c;
059ec3d9
PH
1525 }
1526
1527receive_linecount++; /* For BSMTP errors */
1528os_non_restarting_signal(SIGALRM, sigalrm_handler);
1529
1530/* If hit end of file, return pseudo EOF command. Whether we have a
1531part-line already read doesn't matter, since this is an error state. */
1532
1533if (c == EOF) return EOF_CMD;
1534
1535/* Remove any CR and white space at the end of the line, and terminate the
1536string. */
1537
3ee512ff
PH
1538while (ptr > 0 && isspace(smtp_cmd_buffer[ptr-1])) ptr--;
1539smtp_cmd_buffer[ptr] = 0;
059ec3d9 1540
3ee512ff 1541DEBUG(D_receive) debug_printf("SMTP<< %s\n", smtp_cmd_buffer);
059ec3d9
PH
1542
1543/* NULLs are not allowed in SMTP commands */
1544
1545if (hadnull) return BADCHAR_CMD;
1546
1547/* Scan command list and return identity, having set the data pointer
1548to the start of the actual data characters. Check for SMTP synchronization
1549if required. */
1550
1551for (p = cmd_list; p < cmd_list_end; p++)
1552 {
1811cb4c 1553#ifdef SUPPORT_PROXY
a3c86431 1554 /* Only allow QUIT command if Proxy Protocol parsing failed */
1811cb4c
JH
1555 if (proxy_session && proxy_session_failed && p->cmd != QUIT_CMD)
1556 continue;
1557#endif
2f460950
JH
1558 if ( p->len
1559 && strncmpic(smtp_cmd_buffer, US p->name, p->len) == 0
1560 && ( smtp_cmd_buffer[p->len-1] == ':' /* "mail from:" or "rcpt to:" */
1561 || smtp_cmd_buffer[p->len] == 0
1562 || smtp_cmd_buffer[p->len] == ' '
1563 ) )
059ec3d9
PH
1564 {
1565 if (smtp_inptr < smtp_inend && /* Outstanding input */
1566 p->cmd < sync_cmd_limit && /* Command should sync */
1567 check_sync && /* Local flag set */
1568 smtp_enforce_sync && /* Global flag set */
1569 sender_host_address != NULL && /* Not local input */
1570 !sender_host_notsocket) /* Really is a socket */
1571 return BADSYN_CMD;
1572
ca86f471
PH
1573 /* The variables $smtp_command and $smtp_command_argument point into the
1574 unmodified input buffer. A copy of the latter is taken for actual
1575 processing, so that it can be chopped up into separate parts if necessary,
1576 for example, when processing a MAIL command options such as SIZE that can
1577 follow the sender address. */
059ec3d9 1578
3ee512ff 1579 smtp_cmd_argument = smtp_cmd_buffer + p->len;
ca86f471
PH
1580 while (isspace(*smtp_cmd_argument)) smtp_cmd_argument++;
1581 Ustrcpy(smtp_data_buffer, smtp_cmd_argument);
1582 smtp_cmd_data = smtp_data_buffer;
059ec3d9
PH
1583
1584 /* Count non-mail commands from those hosts that are controlled in this
1585 way. The default is all hosts. We don't waste effort checking the list
1586 until we get a non-mail command, but then cache the result to save checking
1587 again. If there's a DEFER while checking the host, assume it's in the list.
1588
1589 Note that one instance of RSET, EHLO/HELO, and STARTTLS is allowed at the
1590 start of each incoming message by fiddling with the value in the table. */
1591
1592 if (!p->is_mail_cmd)
1593 {
1594 if (count_nonmail == TRUE_UNSET) count_nonmail =
1595 verify_check_host(&smtp_accept_max_nonmail_hosts) != FAIL;
1596 if (count_nonmail && ++nonmail_command_count > smtp_accept_max_nonmail)
1597 return TOO_MANY_NONMAIL_CMD;
1598 }
1599
ca86f471
PH
1600 /* If there is data for a command that does not expect it, generate the
1601 error here. */
059ec3d9 1602
ca86f471 1603 return (p->has_arg || *smtp_cmd_data == 0)? p->cmd : BADARG_CMD;
059ec3d9
PH
1604 }
1605 }
1606
cee5f132 1607#ifdef SUPPORT_PROXY
a3c86431
TL
1608/* Only allow QUIT command if Proxy Protocol parsing failed */
1609if (proxy_session && proxy_session_failed)
1610 return PROXY_FAIL_IGNORE_CMD;
1611#endif
1612
059ec3d9
PH
1613/* Enforce synchronization for unknown commands */
1614
ecce6d9a
JH
1615if ( smtp_inptr < smtp_inend /* Outstanding input */
1616 && check_sync /* Local flag set */
1617 && smtp_enforce_sync /* Global flag set */
1618 && sender_host_address /* Not local input */
1619 && !sender_host_notsocket) /* Really is a socket */
059ec3d9
PH
1620 return BADSYN_CMD;
1621
1622return OTHER_CMD;
1623}
1624
1625
1626
1627/*************************************************
1628* Forced closedown of call *
1629*************************************************/
1630
1631/* This function is called from log.c when Exim is dying because of a serious
1632disaster, and also from some other places. If an incoming non-batched SMTP
1633channel is open, it swallows the rest of the incoming message if in the DATA
1634phase, sends the reply string, and gives an error to all subsequent commands
1635except QUIT. The existence of an SMTP call is detected by the non-NULLness of
1636smtp_in.
1637
8f128379
PH
1638Arguments:
1639 message SMTP reply string to send, excluding the code
1640
059ec3d9
PH
1641Returns: nothing
1642*/
1643
1644void
1645smtp_closedown(uschar *message)
1646{
db57e575 1647if (!smtp_in || smtp_batched_input) return;
059ec3d9 1648receive_swallow_smtp();
925ac8e4 1649smtp_printf("421 %s\r\n", FALSE, message);
059ec3d9 1650
bd8fbe36 1651for (;;) switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED))
059ec3d9 1652 {
60d10ce7 1653 case EOF_CMD:
db57e575 1654 return;
059ec3d9 1655
60d10ce7 1656 case QUIT_CMD:
db57e575
JH
1657 smtp_printf("221 %s closing connection\r\n", FALSE, smtp_active_hostname);
1658 mac_smtp_fflush();
1659 return;
059ec3d9 1660
60d10ce7 1661 case RSET_CMD:
db57e575
JH
1662 smtp_printf("250 Reset OK\r\n", FALSE);
1663 break;
059ec3d9 1664
60d10ce7 1665 default:
db57e575
JH
1666 smtp_printf("421 %s\r\n", FALSE, message);
1667 break;
059ec3d9
PH
1668 }
1669}
1670
1671
1672
1673
1674/*************************************************
1675* Set up connection info for logging *
1676*************************************************/
1677
1678/* This function is called when logging information about an SMTP connection.
1679It sets up appropriate source information, depending on the type of connection.
dac79d3e
PH
1680If sender_fullhost is NULL, we are at a very early stage of the connection;
1681just use the IP address.
059ec3d9
PH
1682
1683Argument: none
1684Returns: a string describing the connection
1685*/
1686
1687uschar *
1688smtp_get_connection_info(void)
1689{
f5d25c2b
JH
1690const uschar * hostname = sender_fullhost
1691 ? sender_fullhost : sender_host_address;
dac79d3e 1692
059ec3d9 1693if (host_checking)
dac79d3e 1694 return string_sprintf("SMTP connection from %s", hostname);
059ec3d9
PH
1695
1696if (sender_host_unknown || sender_host_notsocket)
1697 return string_sprintf("SMTP connection from %s", sender_ident);
1698
1699if (is_inetd)
dac79d3e 1700 return string_sprintf("SMTP connection from %s (via inetd)", hostname);
059ec3d9 1701
6c6d6e48 1702if (LOGGING(incoming_interface) && interface_address != NULL)
dac79d3e 1703 return string_sprintf("SMTP connection from %s I=[%s]:%d", hostname,
059ec3d9
PH
1704 interface_address, interface_port);
1705
dac79d3e 1706return string_sprintf("SMTP connection from %s", hostname);
059ec3d9
PH
1707}
1708
1709
1710
e45a1c37 1711#ifdef SUPPORT_TLS
887291d2
JH
1712/* Append TLS-related information to a log line
1713
1714Arguments:
acec9514 1715 g String under construction: allocated string to extend, or NULL
887291d2
JH
1716
1717Returns: Allocated string or NULL
1718*/
acec9514
JH
1719static gstring *
1720s_tlslog(gstring * g)
e45a1c37 1721{
acec9514
JH
1722if (LOGGING(tls_cipher) && tls_in.cipher)
1723 g = string_append(g, 2, US" X=", tls_in.cipher);
1724if (LOGGING(tls_certificate_verified) && tls_in.cipher)
1725 g = string_append(g, 2, US" CV=", tls_in.certificate_verified? "yes":"no");
1726if (LOGGING(tls_peerdn) && tls_in.peerdn)
1727 g = string_append(g, 3, US" DN=\"", string_printing(tls_in.peerdn), US"\"");
1728if (LOGGING(tls_sni) && tls_in.sni)
1729 g = string_append(g, 3, US" SNI=\"", string_printing(tls_in.sni), US"\"");
1730return g;
e45a1c37
JH
1731}
1732#endif
1733
059ec3d9 1734/*************************************************
b4ed4da0
PH
1735* Log lack of MAIL if so configured *
1736*************************************************/
1737
1738/* This function is called when an SMTP session ends. If the log selector
1739smtp_no_mail is set, write a log line giving some details of what has happened
1740in the SMTP session.
1741
1742Arguments: none
1743Returns: nothing
1744*/
1745
1746void
1747smtp_log_no_mail(void)
1748{
acec9514
JH
1749int i;
1750uschar * sep, * s;
1751gstring * g = NULL;
b4ed4da0 1752
6c6d6e48 1753if (smtp_mailcmd_count > 0 || !LOGGING(smtp_no_mail))
b4ed4da0
PH
1754 return;
1755
db57e575 1756if (sender_host_authenticated)
b4ed4da0 1757 {
acec9514
JH
1758 g = string_append(g, 2, US" A=", sender_host_authenticated);
1759 if (authenticated_id) g = string_append(g, 2, US":", authenticated_id);
b4ed4da0
PH
1760 }
1761
1762#ifdef SUPPORT_TLS
acec9514 1763g = s_tlslog(g);
3f0945ff 1764#endif
b4ed4da0 1765
acec9514
JH
1766sep = smtp_connection_had[SMTP_HBUFF_SIZE-1] != SCH_NONE ? US" C=..." : US" C=";
1767
b4ed4da0 1768for (i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++)
b4ed4da0
PH
1769 if (smtp_connection_had[i] != SCH_NONE)
1770 {
acec9514 1771 g = string_append(g, 2, sep, smtp_names[smtp_connection_had[i]]);
b4ed4da0
PH
1772 sep = US",";
1773 }
b4ed4da0
PH
1774
1775for (i = 0; i < smtp_ch_index; i++)
1776 {
acec9514 1777 g = string_append(g, 2, sep, smtp_names[smtp_connection_had[i]]);
b4ed4da0
PH
1778 sep = US",";
1779 }
1780
acec9514
JH
1781if (!(s = string_from_gstring(g))) s = US"";
1782
a2673768
JH
1783log_write(0, LOG_MAIN, "no MAIL in %sSMTP connection from %s D=%s%s",
1784 tcp_in_fastopen ? US"TFO " : US"",
0f1a8658 1785 host_and_ident(FALSE), string_timesince(&smtp_connection_start), s);
b4ed4da0
PH
1786}
1787
1788
a09f2942
JH
1789/* Return list of recent smtp commands */
1790
1791uschar *
1792smtp_cmd_hist(void)
1793{
acec9514
JH
1794int i;
1795gstring * list = NULL;
1796uschar * s;
a09f2942
JH
1797
1798for (i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++)
1799 if (smtp_connection_had[i] != SCH_NONE)
acec9514
JH
1800 list = string_append_listele(list, ',', smtp_names[smtp_connection_had[i]]);
1801
a09f2942 1802for (i = 0; i < smtp_ch_index; i++)
acec9514
JH
1803 list = string_append_listele(list, ',', smtp_names[smtp_connection_had[i]]);
1804
1805s = string_from_gstring(list);
1806return s ? s : US"";
a09f2942
JH
1807}
1808
1809
1810
b4ed4da0
PH
1811
1812/*************************************************
059ec3d9
PH
1813* Check HELO line and set sender_helo_name *
1814*************************************************/
1815
1816/* Check the format of a HELO line. The data for HELO/EHLO is supposed to be
1817the domain name of the sending host, or an ip literal in square brackets. The
4c04137d 1818argument is placed in sender_helo_name, which is in malloc store, because it
059ec3d9
PH
1819must persist over multiple incoming messages. If helo_accept_junk is set, this
1820host is permitted to send any old junk (needed for some broken hosts).
1821Otherwise, helo_allow_chars can be used for rogue characters in general
1822(typically people want to let in underscores).
1823
1824Argument:
1825 s the data portion of the line (already past any white space)
1826
1827Returns: TRUE or FALSE
1828*/
1829
1830static BOOL
1831check_helo(uschar *s)
1832{
1833uschar *start = s;
1834uschar *end = s + Ustrlen(s);
1835BOOL yield = helo_accept_junk;
1836
1837/* Discard any previous helo name */
1838
2d0dc929 1839if (sender_helo_name)
059ec3d9
PH
1840 {
1841 store_free(sender_helo_name);
1842 sender_helo_name = NULL;
1843 }
1844
1845/* Skip tests if junk is permitted. */
1846
1847if (!yield)
db57e575 1848
059ec3d9
PH
1849 /* Allow the new standard form for IPv6 address literals, namely,
1850 [IPv6:....], and because someone is bound to use it, allow an equivalent
1851 IPv4 form. Allow plain addresses as well. */
1852
1853 if (*s == '[')
1854 {
1855 if (end[-1] == ']')
1856 {
1857 end[-1] = 0;
1858 if (strncmpic(s, US"[IPv6:", 6) == 0)
1859 yield = (string_is_ip_address(s+6, NULL) == 6);
1860 else if (strncmpic(s, US"[IPv4:", 6) == 0)
1861 yield = (string_is_ip_address(s+6, NULL) == 4);
1862 else
1863 yield = (string_is_ip_address(s+1, NULL) != 0);
1864 end[-1] = ']';
1865 }
1866 }
1867
1868 /* Non-literals must be alpha, dot, hyphen, plus any non-valid chars
1869 that have been configured (usually underscore - sigh). */
1870
db57e575
JH
1871 else if (*s)
1872 for (yield = TRUE; *s; s++)
059ec3d9
PH
1873 if (!isalnum(*s) && *s != '.' && *s != '-' &&
1874 Ustrchr(helo_allow_chars, *s) == NULL)
1875 {
1876 yield = FALSE;
1877 break;
1878 }
059ec3d9
PH
1879
1880/* Save argument if OK */
1881
1882if (yield) sender_helo_name = string_copy_malloc(start);
1883return yield;
1884}
1885
1886
1887
1888
1889
1890/*************************************************
1891* Extract SMTP command option *
1892*************************************************/
1893
ca86f471 1894/* This function picks the next option setting off the end of smtp_cmd_data. It
059ec3d9
PH
1895is called for MAIL FROM and RCPT TO commands, to pick off the optional ESMTP
1896things that can appear there.
1897
1898Arguments:
1899 name point this at the name
1900 value point this at the data string
1901
1902Returns: TRUE if found an option
1903*/
1904
1905static BOOL
1906extract_option(uschar **name, uschar **value)
1907{
1908uschar *n;
ca86f471 1909uschar *v = smtp_cmd_data + Ustrlen(smtp_cmd_data) - 1;
059ec3d9
PH
1910while (isspace(*v)) v--;
1911v[1] = 0;
d7a2c833
JH
1912while (v > smtp_cmd_data && *v != '=' && !isspace(*v))
1913 {
1914 /* Take care to not stop at a space embedded in a quoted local-part */
1915
1916 if (*v == '"') do v--; while (*v != '"' && v > smtp_cmd_data+1);
1917 v--;
1918 }
059ec3d9
PH
1919
1920n = v;
fd98a5c6 1921if (*v == '=')
a2673768 1922 {
fd98a5c6
JH
1923 while(isalpha(n[-1])) n--;
1924 /* RFC says SP, but TAB seen in wild and other major MTAs accept it */
1925 if (!isspace(n[-1])) return FALSE;
1926 n[-1] = 0;
a2673768 1927 }
fd98a5c6 1928else
a2673768 1929 {
fd98a5c6
JH
1930 n++;
1931 if (v == smtp_cmd_data) return FALSE;
a2673768 1932 }
059ec3d9 1933*v++ = 0;
fd98a5c6 1934*name = n;
059ec3d9
PH
1935*value = v;
1936return TRUE;
1937}
1938
1939
1940
1941
1942
059ec3d9
PH
1943/*************************************************
1944* Reset for new message *
1945*************************************************/
1946
1947/* This function is called whenever the SMTP session is reset from
e04bfa34 1948within either of the setup functions; also from the daemon loop.
059ec3d9
PH
1949
1950Argument: the stacking pool storage reset point
1951Returns: nothing
1952*/
1953
e04bfa34 1954void
059ec3d9
PH
1955smtp_reset(void *reset_point)
1956{
059ec3d9
PH
1957recipients_list = NULL;
1958rcpt_count = rcpt_defer_count = rcpt_fail_count =
1959 raw_recipients_count = recipients_count = recipients_list_max = 0;
2e0c1448 1960message_linecount = 0;
059ec3d9 1961message_size = -1;
71fafd95 1962acl_added_headers = NULL;
e7568d51 1963acl_removed_headers = NULL;
059ec3d9 1964queue_only_policy = FALSE;
2679d413
PH
1965rcpt_smtp_response = NULL;
1966rcpt_smtp_response_same = TRUE;
1967rcpt_in_progress = FALSE;
69358f02 1968deliver_freeze = FALSE; /* Can be set by ACL */
6a3f1455 1969freeze_tell = freeze_tell_config; /* Can be set by ACL */
29aba418 1970fake_response = OK; /* Can be set by ACL */
6951ac6c 1971#ifdef WITH_CONTENT_SCAN
8523533c
TK
1972no_mbox_unspool = FALSE; /* Can be set by ACL */
1973#endif
69358f02 1974submission_mode = FALSE; /* Can be set by ACL */
f4ee74ac 1975suppress_local_fixups = suppress_local_fixups_default; /* Can be set by ACL */
69358f02
PH
1976active_local_from_check = local_from_check; /* Can be set by ACL */
1977active_local_sender_retain = local_sender_retain; /* Can be set by ACL */
90341c71
JH
1978sending_ip_address = NULL;
1979return_path = sender_address = NULL;
1980sender_data = NULL; /* Can be set by ACL */
c679ee08
JH
1981deliver_localpart_parent = deliver_localpart_orig = NULL;
1982deliver_domain_parent = deliver_domain_orig = NULL;
90341c71 1983callout_address = NULL;
2fe1a124 1984submission_name = NULL; /* Can be set by ACL */
059ec3d9
PH
1985raw_sender = NULL; /* After SMTP rewrite, before qualifying */
1986sender_address_unrewritten = NULL; /* Set only after verify rewrite */
1987sender_verified_list = NULL; /* No senders verified */
1988memset(sender_address_cache, 0, sizeof(sender_address_cache));
1989memset(sender_domain_cache, 0, sizeof(sender_domain_cache));
6c1c3d1d 1990
059ec3d9 1991authenticated_sender = NULL;
8523533c
TK
1992#ifdef EXPERIMENTAL_BRIGHTMAIL
1993bmi_run = 0;
1994bmi_verdicts = NULL;
1995#endif
90341c71 1996dnslist_domain = dnslist_matched = NULL;
80a47a2c 1997#ifndef DISABLE_DKIM
d342446f
JH
1998dkim_cur_signer = dkim_signers =
1999dkim_signing_domain = dkim_signing_selector = NULL;
2000dkim_cur_signer = dkim_signers = dkim_signing_domain = dkim_signing_selector = NULL;
e04bfa34 2001dkim_disable_verify = dkim_collect_input = FALSE;
d342446f
JH
2002dkim_verify_overall = dkim_verify_status = dkim_verify_reason = NULL;
2003dkim_key_length = 0;
2004dkim_verify_signers = US"$dkim_signers";
f7572e5a 2005#endif
aa368db3
JH
2006dsn_ret = 0;
2007dsn_envid = NULL;
90341c71 2008deliver_host = deliver_host_address = NULL; /* Can be set by ACL */
aa368db3
JH
2009#ifndef DISABLE_PRDR
2010prdr_requested = FALSE;
2011#endif
7952eef9 2012#ifdef SUPPORT_SPF
e04bfa34 2013spf_header_comment = spf_received = spf_result = spf_smtp_comment = NULL;
87e9d061 2014spf_result_guessed = FALSE;
8523533c 2015#endif
c780096c
JH
2016#ifdef EXPERIMENTAL_DMARC
2017dmarc_has_been_checked = dmarc_disable_verify = dmarc_enable_forensic = FALSE;
c9cf9ac4 2018dmarc_domain_policy = dmarc_forensic_sender =
c780096c 2019dmarc_history_file = dmarc_status = dmarc_status_text =
9a1edd98 2020dmarc_used_domain = NULL;
c780096c 2021#endif
93c931f8
JH
2022#ifdef EXPERIMENTAL_ARC
2023arc_state = arc_state_reason = NULL;
2024#endif
8c5d388a 2025#ifdef SUPPORT_I18N
d1a13eea
JH
2026message_smtputf8 = FALSE;
2027#endif
059ec3d9
PH
2028body_linecount = body_zerocount = 0;
2029
870f6ba8
TF
2030sender_rate = sender_rate_limit = sender_rate_period = NULL;
2031ratelimiters_mail = NULL; /* Updated by ratelimit ACL condition */
2032 /* Note that ratelimiters_conn persists across resets. */
2033
38a0a95f 2034/* Reset message ACL variables */
47ca6d6c 2035
38a0a95f 2036acl_var_m = NULL;
059ec3d9
PH
2037
2038/* The message body variables use malloc store. They may be set if this is
2039not the first message in an SMTP session and the previous message caused them
2040to be referenced in an ACL. */
2041
90341c71 2042if (message_body)
059ec3d9
PH
2043 {
2044 store_free(message_body);
2045 message_body = NULL;
2046 }
2047
90341c71 2048if (message_body_end)
059ec3d9
PH
2049 {
2050 store_free(message_body_end);
2051 message_body_end = NULL;
2052 }
2053
2054/* Warning log messages are also saved in malloc store. They are saved to avoid
2055repetition in the same message, but it seems right to repeat them for different
4e88a19f 2056messages. */
059ec3d9 2057
90341c71 2058while (acl_warn_logged)
059ec3d9
PH
2059 {
2060 string_item *this = acl_warn_logged;
2061 acl_warn_logged = acl_warn_logged->next;
2062 store_free(this);
2063 }
90341c71 2064store_reset(reset_point);
059ec3d9
PH
2065}
2066
2067
2068
2069
2070
2071/*************************************************
2072* Initialize for incoming batched SMTP message *
2073*************************************************/
2074
2075/* This function is called from smtp_setup_msg() in the case when
2076smtp_batched_input is true. This happens when -bS is used to pass a whole batch
2077of messages in one file with SMTP commands between them. All errors must be
2078reported by sending a message, and only MAIL FROM, RCPT TO, and DATA are
2079relevant. After an error on a sender, or an invalid recipient, the remainder
2080of the message is skipped. The value of received_protocol is already set.
2081
2082Argument: none
2083Returns: > 0 message successfully started (reached DATA)
2084 = 0 QUIT read or end of file reached
2085 < 0 should not occur
2086*/
2087
2088static int
2089smtp_setup_batch_msg(void)
2090{
2091int done = 0;
2092void *reset_point = store_get(0);
2093
2094/* Save the line count at the start of each transaction - single commands
2095like HELO and RSET count as whole transactions. */
2096
2097bsmtp_transaction_linecount = receive_linecount;
2098
2099if ((receive_feof)()) return 0; /* Treat EOF as QUIT */
2100
57cc2785 2101cancel_cutthrough_connection(TRUE, US"smtp_setup_batch_msg");
059ec3d9
PH
2102smtp_reset(reset_point); /* Reset for start of message */
2103
2104/* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
2105value. The values are 2 larger than the required yield of the function. */
2106
2107while (done <= 0)
2108 {
2109 uschar *errmess;
2110 uschar *recipient = NULL;
2111 int start, end, sender_domain, recipient_domain;
2112
bd8fbe36 2113 switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED))
059ec3d9
PH
2114 {
2115 /* The HELO/EHLO commands set sender_address_helo if they have
2116 valid data; otherwise they are ignored, except that they do
2117 a reset of the state. */
2118
2119 case HELO_CMD:
2120 case EHLO_CMD:
2121
db57e575
JH
2122 check_helo(smtp_cmd_data);
2123 /* Fall through */
059ec3d9
PH
2124
2125 case RSET_CMD:
db57e575
JH
2126 cancel_cutthrough_connection(TRUE, US"RSET received");
2127 smtp_reset(reset_point);
2128 bsmtp_transaction_linecount = receive_linecount;
2129 break;
059ec3d9
PH
2130
2131
2132 /* The MAIL FROM command requires an address as an operand. All we
2133 do here is to parse it for syntactic correctness. The form "<>" is
2134 a special case which converts into an empty string. The start/end
2135 pointers in the original are not used further for this address, as
2136 it is the canonical extracted address which is all that is kept. */
2137
2138 case MAIL_CMD:
db57e575
JH
2139 smtp_mailcmd_count++; /* Count for no-mail log */
2140 if (sender_address != NULL)
2141 /* The function moan_smtp_batch() does not return. */
2142 moan_smtp_batch(smtp_cmd_buffer, "503 Sender already given");
059ec3d9 2143
db57e575
JH
2144 if (smtp_cmd_data[0] == 0)
2145 /* The function moan_smtp_batch() does not return. */
2146 moan_smtp_batch(smtp_cmd_buffer, "501 MAIL FROM must have an address operand");
059ec3d9 2147
db57e575 2148 /* Reset to start of message */
059ec3d9 2149
db57e575
JH
2150 cancel_cutthrough_connection(TRUE, US"MAIL received");
2151 smtp_reset(reset_point);
059ec3d9 2152
db57e575 2153 /* Apply SMTP rewrite */
059ec3d9 2154
db57e575
JH
2155 raw_sender = ((rewrite_existflags & rewrite_smtp) != 0)?
2156 rewrite_one(smtp_cmd_data, rewrite_smtp|rewrite_smtp_sender, NULL, FALSE,
2157 US"", global_rewrite_rules) : smtp_cmd_data;
059ec3d9 2158
db57e575 2159 /* Extract the address; the TRUE flag allows <> as valid */
059ec3d9 2160
db57e575
JH
2161 raw_sender =
2162 parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain,
2163 TRUE);
059ec3d9 2164
db57e575
JH
2165 if (!raw_sender)
2166 /* The function moan_smtp_batch() does not return. */
2167 moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
059ec3d9 2168
db57e575 2169 sender_address = string_copy(raw_sender);
059ec3d9 2170
db57e575 2171 /* Qualify unqualified sender addresses if permitted to do so. */
059ec3d9 2172
db57e575
JH
2173 if ( !sender_domain
2174 && sender_address[0] != 0 && sender_address[0] != '@')
2175 if (allow_unqualified_sender)
2176 {
2177 sender_address = rewrite_address_qualify(sender_address, FALSE);
2178 DEBUG(D_receive) debug_printf("unqualified address %s accepted "
2179 "and rewritten\n", raw_sender);
2180 }
2181 /* The function moan_smtp_batch() does not return. */
2182 else
2183 moan_smtp_batch(smtp_cmd_buffer, "501 sender address must contain "
2184 "a domain");
2185 break;
059ec3d9
PH
2186
2187
2188 /* The RCPT TO command requires an address as an operand. All we do
2189 here is to parse it for syntactic correctness. There may be any number
2190 of RCPT TO commands, specifying multiple senders. We build them all into
2191 a data structure that is in argc/argv format. The start/end values
2192 given by parse_extract_address are not used, as we keep only the
2193 extracted address. */
2194
2195 case RCPT_CMD:
db57e575
JH
2196 if (!sender_address)
2197 /* The function moan_smtp_batch() does not return. */
2198 moan_smtp_batch(smtp_cmd_buffer, "503 No sender yet given");
059ec3d9 2199
db57e575
JH
2200 if (smtp_cmd_data[0] == 0)
2201 /* The function moan_smtp_batch() does not return. */
2202 moan_smtp_batch(smtp_cmd_buffer,
2203 "501 RCPT TO must have an address operand");
059ec3d9 2204
db57e575 2205 /* Check maximum number allowed */
059ec3d9 2206
db57e575
JH
2207 if (recipients_max > 0 && recipients_count + 1 > recipients_max)
2208 /* The function moan_smtp_batch() does not return. */
2209 moan_smtp_batch(smtp_cmd_buffer, "%s too many recipients",
2210 recipients_max_reject? "552": "452");
059ec3d9 2211
db57e575
JH
2212 /* Apply SMTP rewrite, then extract address. Don't allow "<>" as a
2213 recipient address */
059ec3d9 2214
db57e575
JH
2215 recipient = rewrite_existflags & rewrite_smtp
2216 ? rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
2217 global_rewrite_rules)
2218 : smtp_cmd_data;
059ec3d9 2219
db57e575
JH
2220 recipient = parse_extract_address(recipient, &errmess, &start, &end,
2221 &recipient_domain, FALSE);
059ec3d9 2222
db57e575
JH
2223 if (!recipient)
2224 /* The function moan_smtp_batch() does not return. */
2225 moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
059ec3d9 2226
db57e575
JH
2227 /* If the recipient address is unqualified, qualify it if permitted. Then
2228 add it to the list of recipients. */
059ec3d9 2229
db57e575
JH
2230 if (!recipient_domain)
2231 if (allow_unqualified_recipient)
2232 {
2233 DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
2234 recipient);
2235 recipient = rewrite_address_qualify(recipient, TRUE);
2236 }
2237 /* The function moan_smtp_batch() does not return. */
2238 else
2239 moan_smtp_batch(smtp_cmd_buffer,
2240 "501 recipient address must contain a domain");
2241
2242 receive_add_recipient(recipient, -1);
2243 break;
059ec3d9
PH
2244
2245
2246 /* The DATA command is legal only if it follows successful MAIL FROM
2247 and RCPT TO commands. This function is complete when a valid DATA
2248 command is encountered. */
2249
2250 case DATA_CMD:
db57e575
JH
2251 if (!sender_address || recipients_count <= 0)
2252 /* The function moan_smtp_batch() does not return. */
2253 if (!sender_address)
2254 moan_smtp_batch(smtp_cmd_buffer,
2255 "503 MAIL FROM:<sender> command must precede DATA");
2256 else
2257 moan_smtp_batch(smtp_cmd_buffer,
2258 "503 RCPT TO:<recipient> must precede DATA");
059ec3d9 2259 else
db57e575
JH
2260 {
2261 done = 3; /* DATA successfully achieved */
2262 message_ended = END_NOTENDED; /* Indicate in middle of message */
2263 }
2264 break;
059ec3d9
PH
2265
2266
2267 /* The VRFY, EXPN, HELP, ETRN, and NOOP commands are ignored. */
2268
2269 case VRFY_CMD:
2270 case EXPN_CMD:
2271 case HELP_CMD:
2272 case NOOP_CMD:
2273 case ETRN_CMD:
db57e575
JH
2274 bsmtp_transaction_linecount = receive_linecount;
2275 break;
059ec3d9
PH
2276
2277
2278 case EOF_CMD:
2279 case QUIT_CMD:
db57e575
JH
2280 done = 2;
2281 break;
059ec3d9
PH
2282
2283
2284 case BADARG_CMD:
db57e575
JH
2285 /* The function moan_smtp_batch() does not return. */
2286 moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected argument data");
2287 break;
059ec3d9
PH
2288
2289
2290 case BADCHAR_CMD:
db57e575
JH
2291 /* The function moan_smtp_batch() does not return. */
2292 moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected NULL in SMTP command");
2293 break;
059ec3d9
PH
2294
2295
2296 default:
db57e575
JH
2297 /* The function moan_smtp_batch() does not return. */
2298 moan_smtp_batch(smtp_cmd_buffer, "500 Command unrecognized");
2299 break;
059ec3d9
PH
2300 }
2301 }
2302
2303return done - 2; /* Convert yield values */
2304}
2305
2306
2307
2308
cf0c6164
JH
2309static BOOL
2310smtp_log_tls_fail(uschar * errstr)
2311{
2312uschar * conn_info = smtp_get_connection_info();
2313
2314if (Ustrncmp(conn_info, US"SMTP ", 5) == 0) conn_info += 5;
2315/* I'd like to get separated H= here, but too hard for now */
2316
2317log_write(0, LOG_MAIN, "TLS error on %s %s", conn_info, errstr);
2318return FALSE;
2319}
2320
2321
a2673768
JH
2322
2323
2324#ifdef TCP_FASTOPEN
2325static void
2326tfo_in_check(void)
2327{
2328# ifdef TCP_INFO
2329struct tcp_info tinfo;
2330socklen_t len = sizeof(tinfo);
2331
2332if ( getsockopt(fileno(smtp_out), IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0
2333 && tinfo.tcpi_state == TCP_SYN_RECV
2334 )
2335 {
1ccd5f67 2336 DEBUG(D_receive) debug_printf("TCP_FASTOPEN mode connection (state TCP_SYN_RECV)\n");
a2673768
JH
2337 tcp_in_fastopen = TRUE;
2338 }
2339# endif
2340}
2341#endif
2342
2343
059ec3d9
PH
2344/*************************************************
2345* Start an SMTP session *
2346*************************************************/
2347
2348/* This function is called at the start of an SMTP session. Thereafter,
2349smtp_setup_msg() is called to initiate each separate message. This
2350function does host-specific testing, and outputs the banner line.
2351
2352Arguments: none
2353Returns: FALSE if the session can not continue; something has
2354 gone wrong, or the connection to the host is blocked
2355*/
2356
2357BOOL
2358smtp_start_session(void)
2359{
acec9514 2360int esclen;
4e88a19f
PH
2361uschar *user_msg, *log_msg;
2362uschar *code, *esc;
acec9514
JH
2363uschar *p, *s;
2364gstring * ss;
059ec3d9 2365
0f1a8658 2366gettimeofday(&smtp_connection_start, NULL);
b4ed4da0
PH
2367for (smtp_ch_index = 0; smtp_ch_index < SMTP_HBUFF_SIZE; smtp_ch_index++)
2368 smtp_connection_had[smtp_ch_index] = SCH_NONE;
2369smtp_ch_index = 0;
2370
00f00ca5
PH
2371/* Default values for certain variables */
2372
059ec3d9 2373helo_seen = esmtp = helo_accept_junk = FALSE;
b4ed4da0 2374smtp_mailcmd_count = 0;
059ec3d9
PH
2375count_nonmail = TRUE_UNSET;
2376synprot_error_count = unknown_command_count = nonmail_command_count = 0;
2377smtp_delay_mail = smtp_rlm_base;
2378auth_advertised = FALSE;
2379pipelining_advertised = FALSE;
cf8b11a5 2380pipelining_enable = TRUE;
059ec3d9 2381sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING;
8f128379 2382smtp_exit_function_called = FALSE; /* For avoiding loop in not-quit exit */
059ec3d9 2383
33d73e3b
PH
2384/* If receiving by -bs from a trusted user, or testing with -bh, we allow
2385authentication settings from -oMaa to remain in force. */
2386
c44ff8be
JH
2387if (!host_checking && !sender_host_notsocket)
2388 sender_host_auth_pubname = sender_host_authenticated = NULL;
059ec3d9
PH
2389authenticated_by = NULL;
2390
2391#ifdef SUPPORT_TLS
817d9f57 2392tls_in.cipher = tls_in.peerdn = NULL;
9d1c15ef
JH
2393tls_in.ourcert = tls_in.peercert = NULL;
2394tls_in.sni = NULL;
44662487 2395tls_in.ocsp = OCSP_NOT_REQ;
059ec3d9
PH
2396tls_advertised = FALSE;
2397#endif
6c1c3d1d 2398dsn_advertised = FALSE;
8c5d388a 2399#ifdef SUPPORT_I18N
d1a13eea
JH
2400smtputf8_advertised = FALSE;
2401#endif
059ec3d9
PH
2402
2403/* Reset ACL connection variables */
2404
38a0a95f 2405acl_var_c = NULL;
059ec3d9 2406
ca86f471 2407/* Allow for trailing 0 in the command and data buffers. */
3ee512ff 2408
bd8fbe36 2409if (!(smtp_cmd_buffer = US malloc(2*SMTP_CMD_BUFFER_SIZE + 2)))
059ec3d9
PH
2410 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2411 "malloc() failed for SMTP command buffer");
40c90bca 2412
2416c261 2413smtp_cmd_buffer[0] = 0;
bd8fbe36 2414smtp_data_buffer = smtp_cmd_buffer + SMTP_CMD_BUFFER_SIZE + 1;
059ec3d9
PH
2415
2416/* For batched input, the protocol setting can be overridden from the
2417command line by a trusted caller. */
2418
2419if (smtp_batched_input)
2420 {
40c90bca 2421 if (!received_protocol) received_protocol = US"local-bsmtp";
059ec3d9
PH
2422 }
2423
2424/* For non-batched SMTP input, the protocol setting is forced here. It will be
2425reset later if any of EHLO/AUTH/STARTTLS are received. */
2426
2427else
2428 received_protocol =
e524074d 2429 (sender_host_address ? protocols : protocols_local) [pnormal];
059ec3d9
PH
2430
2431/* Set up the buffer for inputting using direct read() calls, and arrange to
ecce6d9a
JH
2432call the local functions instead of the standard C ones. Place a NUL at the
2433end of the buffer to safety-stop C-string reads from it. */
059ec3d9 2434
5903c6ff 2435if (!(smtp_inbuffer = US malloc(IN_BUFFER_SIZE)))
059ec3d9 2436 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "malloc() failed for SMTP input buffer");
ecce6d9a 2437smtp_inbuffer[IN_BUFFER_SIZE-1] = '\0';
40c90bca 2438
059ec3d9 2439receive_getc = smtp_getc;
0d81dabc 2440receive_getbuf = smtp_getbuf;
584e96c6 2441receive_get_cache = smtp_get_cache;
059ec3d9
PH
2442receive_ungetc = smtp_ungetc;
2443receive_feof = smtp_feof;
2444receive_ferror = smtp_ferror;
58eb016e 2445receive_smtp_buffered = smtp_buffered;
059ec3d9
PH
2446smtp_inptr = smtp_inend = smtp_inbuffer;
2447smtp_had_eof = smtp_had_error = 0;
2448
2449/* Set up the message size limit; this may be host-specific */
2450
d45b1de8 2451thismessage_size_limit = expand_string_integer(message_size_limit, TRUE);
db57e575 2452if (expand_string_message)
059ec3d9
PH
2453 {
2454 if (thismessage_size_limit == -1)
2455 log_write(0, LOG_MAIN|LOG_PANIC, "unable to expand message_size_limit: "
2456 "%s", expand_string_message);
2457 else
2458 log_write(0, LOG_MAIN|LOG_PANIC, "invalid message_size_limit: "
2459 "%s", expand_string_message);
2460 smtp_closedown(US"Temporary local problem - please try later");
2461 return FALSE;
2462 }
2463
2464/* When a message is input locally via the -bs or -bS options, sender_host_
2465unknown is set unless -oMa was used to force an IP address, in which case it
2466is checked like a real remote connection. When -bs is used from inetd, this
2467flag is not set, causing the sending host to be checked. The code that deals
2468with IP source routing (if configured) is never required for -bs or -bS and
2469the flag sender_host_notsocket is used to suppress it.
2470
2471If smtp_accept_max and smtp_accept_reserve are set, keep some connections in
2472reserve for certain hosts and/or networks. */
2473
2474if (!sender_host_unknown)
2475 {
2476 int rc;
2477 BOOL reserved_host = FALSE;
2478
2479 /* Look up IP options (source routing info) on the socket if this is not an
2480 -oMa "host", and if any are found, log them and drop the connection.
2481
2482 Linux (and others now, see below) is different to everyone else, so there
2483 has to be some conditional compilation here. Versions of Linux before 2.1.15
2484 used a structure whose name was "options". Somebody finally realized that
2485 this name was silly, and it got changed to "ip_options". I use the
2486 newer name here, but there is a fudge in the script that sets up os.h
2487 to define a macro in older Linux systems.
2488
2489 Sigh. Linux is a fast-moving target. Another generation of Linux uses
2490 glibc 2, which has chosen ip_opts for the structure name. This is now
2491 really a glibc thing rather than a Linux thing, so the condition name
2492 has been changed to reflect this. It is relevant also to GNU/Hurd.
2493
2494 Mac OS 10.x (Darwin) is like the later glibc versions, but without the
2495 setting of the __GLIBC__ macro, so we can't detect it automatically. There's
2496 a special macro defined in the os.h file.
2497
2498 Some DGUX versions on older hardware appear not to support IP options at
2499 all, so there is now a general macro which can be set to cut out this
2500 support altogether.
2501
2502 How to do this properly in IPv6 is not yet known. */
2503
2504 #if !HAVE_IPV6 && !defined(NO_IP_OPTIONS)
2505
2506 #ifdef GLIBC_IP_OPTIONS
2507 #if (!defined __GLIBC__) || (__GLIBC__ < 2)
2508 #define OPTSTYLE 1
2509 #else
2510 #define OPTSTYLE 2
2511 #endif
2512 #elif defined DARWIN_IP_OPTIONS
2513 #define OPTSTYLE 2
2514 #else
2515 #define OPTSTYLE 3
2516 #endif
2517
2518 if (!host_checking && !sender_host_notsocket)
2519 {
2520 #if OPTSTYLE == 1
36a3b041 2521 EXIM_SOCKLEN_T optlen = sizeof(struct ip_options) + MAX_IPOPTLEN;
059ec3d9
PH
2522 struct ip_options *ipopt = store_get(optlen);
2523 #elif OPTSTYLE == 2
2524 struct ip_opts ipoptblock;
2525 struct ip_opts *ipopt = &ipoptblock;
36a3b041 2526 EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
059ec3d9
PH
2527 #else
2528 struct ipoption ipoptblock;
2529 struct ipoption *ipopt = &ipoptblock;
36a3b041 2530 EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
059ec3d9
PH
2531 #endif
2532
2533 /* Occasional genuine failures of getsockopt() have been seen - for
2534 example, "reset by peer". Therefore, just log and give up on this
2535 call, unless the error is ENOPROTOOPT. This error is given by systems
2536 that have the interfaces but not the mechanism - e.g. GNU/Hurd at the time
2537 of writing. So for that error, carry on - we just can't do an IP options
2538 check. */
2539
2540 DEBUG(D_receive) debug_printf("checking for IP options\n");
2541
5903c6ff 2542 if (getsockopt(fileno(smtp_out), IPPROTO_IP, IP_OPTIONS, US (ipopt),
059ec3d9
PH
2543 &optlen) < 0)
2544 {
2545 if (errno != ENOPROTOOPT)
2546 {
2547 log_write(0, LOG_MAIN, "getsockopt() failed from %s: %s",
2548 host_and_ident(FALSE), strerror(errno));
925ac8e4 2549 smtp_printf("451 SMTP service not available\r\n", FALSE);
059ec3d9
PH
2550 return FALSE;
2551 }
2552 }
2553
2554 /* Deal with any IP options that are set. On the systems I have looked at,
2555 the value of MAX_IPOPTLEN has been 40, meaning that there should never be
2556 more logging data than will fit in big_buffer. Nevertheless, after somebody
2557 questioned this code, I've added in some paranoid checking. */
2558
2559 else if (optlen > 0)
2560 {
2561 uschar *p = big_buffer;
2562 uschar *pend = big_buffer + big_buffer_size;
2563 uschar *opt, *adptr;
2564 int optcount;
2565 struct in_addr addr;
2566
2567 #if OPTSTYLE == 1
5903c6ff 2568 uschar *optstart = US (ipopt->__data);
059ec3d9 2569 #elif OPTSTYLE == 2
5903c6ff 2570 uschar *optstart = US (ipopt->ip_opts);
059ec3d9 2571 #else
5903c6ff 2572 uschar *optstart = US (ipopt->ipopt_list);
059ec3d9
PH
2573 #endif
2574
2575 DEBUG(D_receive) debug_printf("IP options exist\n");
2576
2577 Ustrcpy(p, "IP options on incoming call:");
2578 p += Ustrlen(p);
2579
2580 for (opt = optstart; opt != NULL &&
5903c6ff 2581 opt < US (ipopt) + optlen;)
059ec3d9
PH
2582 {
2583 switch (*opt)
2584 {
2585 case IPOPT_EOL:
2586 opt = NULL;
2587 break;
2588
2589 case IPOPT_NOP:
2590 opt++;
2591 break;
2592
2593 case IPOPT_SSRR:
2594 case IPOPT_LSRR:
2595 if (!string_format(p, pend-p, " %s [@%s",
2596 (*opt == IPOPT_SSRR)? "SSRR" : "LSRR",
2597 #if OPTSTYLE == 1
2598 inet_ntoa(*((struct in_addr *)(&(ipopt->faddr))))))
2599 #elif OPTSTYLE == 2
2600 inet_ntoa(ipopt->ip_dst)))
2601 #else
2602 inet_ntoa(ipopt->ipopt_dst)))
2603 #endif
2604 {
2605 opt = NULL;
2606 break;
2607 }
2608
2609 p += Ustrlen(p);
2610 optcount = (opt[1] - 3) / sizeof(struct in_addr);
2611 adptr = opt + 3;
2612 while (optcount-- > 0)
2613 {
2614 memcpy(&addr, adptr, sizeof(addr));
2615 if (!string_format(p, pend - p - 1, "%s%s",
2616 (optcount == 0)? ":" : "@", inet_ntoa(addr)))
2617 {
2618 opt = NULL;
2619 break;
2620 }
2621 p += Ustrlen(p);
2622 adptr += sizeof(struct in_addr);
2623 }
2624 *p++ = ']';
2625 opt += opt[1];
2626 break;
2627
2628 default:
2629 {
2630 int i;
2631 if (pend - p < 4 + 3*opt[1]) { opt = NULL; break; }
2632 Ustrcat(p, "[ ");
2633 p += 2;
2634 for (i = 0; i < opt[1]; i++)
5976eb99 2635 p += sprintf(CS p, "%2.2x ", opt[i]);
059ec3d9
PH
2636 *p++ = ']';
2637 }
2638 opt += opt[1];
2639 break;
2640 }
2641 }
2642
2643 *p = 0;
2644 log_write(0, LOG_MAIN, "%s", big_buffer);
2645
2646 /* Refuse any call with IP options. This is what tcpwrappers 7.5 does. */
2647
2648 log_write(0, LOG_MAIN|LOG_REJECT,
2649 "connection from %s refused (IP options)", host_and_ident(FALSE));
2650
925ac8e4 2651 smtp_printf("554 SMTP service not available\r\n", FALSE);
059ec3d9
PH
2652 return FALSE;
2653 }
2654
2655 /* Length of options = 0 => there are no options */
2656
2657 else DEBUG(D_receive) debug_printf("no IP options found\n");
2658 }
2659 #endif /* HAVE_IPV6 && !defined(NO_IP_OPTIONS) */
2660
2661 /* Set keep-alive in socket options. The option is on by default. This
2662 setting is an attempt to get rid of some hanging connections that stick in
2663 read() when the remote end (usually a dialup) goes away. */
2664
2665 if (smtp_accept_keepalive && !sender_host_notsocket)
2666 ip_keepalive(fileno(smtp_out), sender_host_address, FALSE);
2667
2668 /* If the current host matches host_lookup, set the name by doing a
2669 reverse lookup. On failure, sender_host_name will be NULL and
2670 host_lookup_failed will be TRUE. This may or may not be serious - optional
2671 checks later. */
2672
2673 if (verify_check_host(&host_lookup) == OK)
2674 {
2675 (void)host_name_lookup();
2676 host_build_sender_fullhost();
2677 }
2678
2679 /* Delay this until we have the full name, if it is looked up. */
2680
2681 set_process_info("handling incoming connection from %s",
2682 host_and_ident(FALSE));
2683
1ad6489e
JH
2684 /* Expand smtp_receive_timeout, if needed */
2685
2686 if (smtp_receive_timeout_s)
2687 {
2688 uschar * exp;
2689 if ( !(exp = expand_string(smtp_receive_timeout_s))
2690 || !(*exp)
2691 || (smtp_receive_timeout = readconf_readtime(exp, 0, FALSE)) < 0
2692 )
2693 log_write(0, LOG_MAIN|LOG_PANIC,
2694 "bad value for smtp_receive_timeout: '%s'", exp ? exp : US"");
2695 }
2696
059ec3d9
PH
2697 /* Test for explicit connection rejection */
2698
2699 if (verify_check_host(&host_reject_connection) == OK)
2700 {
2701 log_write(L_connection_reject, LOG_MAIN|LOG_REJECT, "refused connection "
2702 "from %s (host_reject_connection)", host_and_ident(FALSE));
925ac8e4 2703 smtp_printf("554 SMTP service not available\r\n", FALSE);
059ec3d9
PH
2704 return FALSE;
2705 }
2706
afb3eaaf
PH
2707 /* Test with TCP Wrappers if so configured. There is a problem in that
2708 hosts_ctl() returns 0 (deny) under a number of system failure circumstances,
2709 such as disks dying. In these cases, it is desirable to reject with a 4xx
2710 error instead of a 5xx error. There isn't a "right" way to detect such
2711 problems. The following kludge is used: errno is zeroed before calling
2712 hosts_ctl(). If the result is "reject", a 5xx error is given only if the
2713 value of errno is 0 or ENOENT (which happens if /etc/hosts.{allow,deny} does
2714 not exist). */
059ec3d9 2715
1811cb4c 2716#ifdef USE_TCP_WRAPPERS
afb3eaaf 2717 errno = 0;
1811cb4c 2718 if (!(tcp_wrappers_name = expand_string(tcp_wrappers_daemon_name)))
5dc43717
JJ
2719 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" "
2720 "(tcp_wrappers_name) failed: %s", string_printing(tcp_wrappers_name),
2721 expand_string_message);
1811cb4c 2722
5dc43717 2723 if (!hosts_ctl(tcp_wrappers_name,
1811cb4c
JH
2724 sender_host_name ? CS sender_host_name : STRING_UNKNOWN,
2725 sender_host_address ? CS sender_host_address : STRING_UNKNOWN,
2726 sender_ident ? CS sender_ident : STRING_UNKNOWN))
059ec3d9 2727 {
afb3eaaf
PH
2728 if (errno == 0 || errno == ENOENT)
2729 {
2730 HDEBUG(D_receive) debug_printf("tcp wrappers rejection\n");
2731 log_write(L_connection_reject,
2732 LOG_MAIN|LOG_REJECT, "refused connection from %s "
2733 "(tcp wrappers)", host_and_ident(FALSE));
925ac8e4 2734 smtp_printf("554 SMTP service not available\r\n", FALSE);
afb3eaaf
PH
2735 }
2736 else
2737 {
2738 int save_errno = errno;
2739 HDEBUG(D_receive) debug_printf("tcp wrappers rejected with unexpected "
2740 "errno value %d\n", save_errno);
2741 log_write(L_connection_reject,
2742 LOG_MAIN|LOG_REJECT, "temporarily refused connection from %s "
2743 "(tcp wrappers errno=%d)", host_and_ident(FALSE), save_errno);
925ac8e4 2744 smtp_printf("451 Temporary local problem - please try later\r\n", FALSE);
afb3eaaf 2745 }
059ec3d9
PH
2746 return FALSE;
2747 }
1811cb4c 2748#endif
059ec3d9 2749
b01dd148
PH
2750 /* Check for reserved slots. The value of smtp_accept_count has already been
2751 incremented to include this process. */
059ec3d9
PH
2752
2753 if (smtp_accept_max > 0 &&
b01dd148 2754 smtp_accept_count > smtp_accept_max - smtp_accept_reserve)
059ec3d9
PH
2755 {
2756 if ((rc = verify_check_host(&smtp_reserve_hosts)) != OK)
2757 {
2758 log_write(L_connection_reject,
2759 LOG_MAIN, "temporarily refused connection from %s: not in "
2760 "reserve list: connected=%d max=%d reserve=%d%s",
b01dd148 2761 host_and_ident(FALSE), smtp_accept_count - 1, smtp_accept_max,
059ec3d9
PH
2762 smtp_accept_reserve, (rc == DEFER)? " (lookup deferred)" : "");
2763 smtp_printf("421 %s: Too many concurrent SMTP connections; "
925ac8e4 2764 "please try again later\r\n", FALSE, smtp_active_hostname);
059ec3d9
PH
2765 return FALSE;
2766 }
2767 reserved_host = TRUE;
2768 }
2769
2770 /* If a load level above which only messages from reserved hosts are
2771 accepted is set, check the load. For incoming calls via the daemon, the
2772 check is done in the superior process if there are no reserved hosts, to
2773 save a fork. In all cases, the load average will already be available
2774 in a global variable at this point. */
2775
2776 if (smtp_load_reserve >= 0 &&
2777 load_average > smtp_load_reserve &&
2778 !reserved_host &&
2779 verify_check_host(&smtp_reserve_hosts) != OK)
2780 {
2781 log_write(L_connection_reject,
2782 LOG_MAIN, "temporarily refused connection from %s: not in "
2783 "reserve list and load average = %.2f", host_and_ident(FALSE),
2784 (double)load_average/1000.0);
925ac8e4 2785 smtp_printf("421 %s: Too much load; please try again later\r\n", FALSE,
059ec3d9
PH
2786 smtp_active_hostname);
2787 return FALSE;
2788 }
2789
2790 /* Determine whether unqualified senders or recipients are permitted
2791 for this host. Unfortunately, we have to do this every time, in order to
2792 set the flags so that they can be inspected when considering qualifying
2793 addresses in the headers. For a site that permits no qualification, this
2794 won't take long, however. */
2795
2796 allow_unqualified_sender =
2797 verify_check_host(&sender_unqualified_hosts) == OK;
2798
2799 allow_unqualified_recipient =
2800 verify_check_host(&recipient_unqualified_hosts) == OK;
2801
2802 /* Determine whether HELO/EHLO is required for this host. The requirement
2803 can be hard or soft. */
2804
2805 helo_required = verify_check_host(&helo_verify_hosts) == OK;
2806 if (!helo_required)
2807 helo_verify = verify_check_host(&helo_try_verify_hosts) == OK;
2808
2809 /* Determine whether this hosts is permitted to send syntactic junk
2810 after a HELO or EHLO command. */
2811
2812 helo_accept_junk = verify_check_host(&helo_accept_junk_hosts) == OK;
2813 }
2814
2815/* For batch SMTP input we are now done. */
2816
2817if (smtp_batched_input) return TRUE;
2818
a3c86431
TL
2819/* If valid Proxy Protocol source is connecting, set up session.
2820 * Failure will not allow any SMTP function other than QUIT. */
1811cb4c
JH
2821
2822#ifdef SUPPORT_PROXY
a3c86431
TL
2823proxy_session = FALSE;
2824proxy_session_failed = FALSE;
2825if (check_proxy_protocol_host())
1811cb4c
JH
2826 setup_proxy_protocol_host();
2827#endif
2828
2829 /* Start up TLS if tls_on_connect is set. This is for supporting the legacy
2830 smtps port for use with older style SSL MTAs. */
2831
2832#ifdef SUPPORT_TLS
69d8eed7
JH
2833 if (tls_in.on_connect)
2834 {
2835 if (tls_server_start(tls_require_ciphers, &user_msg) != OK)
2836 return smtp_log_tls_fail(user_msg);
2837 cmd_list[CMD_LIST_TLS_AUTH].is_mail_cmd = TRUE;
2838 }
a3c86431
TL
2839#endif
2840
1811cb4c 2841/* Run the connect ACL if it exists */
059ec3d9 2842
4e88a19f 2843user_msg = NULL;
3cc3f762 2844if (acl_smtp_connect)
059ec3d9
PH
2845 {
2846 int rc;
3cc3f762
JH
2847 if ((rc = acl_check(ACL_WHERE_CONNECT, NULL, acl_smtp_connect, &user_msg,
2848 &log_msg)) != OK)
059ec3d9 2849 {
3cc3f762 2850 (void) smtp_handle_acl_fail(ACL_WHERE_CONNECT, rc, user_msg, log_msg);
059ec3d9
PH
2851 return FALSE;
2852 }
2853 }
2854
2855/* Output the initial message for a two-way SMTP connection. It may contain
2856newlines, which then cause a multi-line response to be given. */
2857
4e88a19f
PH
2858code = US"220"; /* Default status code */
2859esc = US""; /* Default extended status code */
2860esclen = 0; /* Length of esc */
2861
d4ff61d1 2862if (!user_msg)
4e88a19f 2863 {
d4ff61d1 2864 if (!(s = expand_string(smtp_banner)))
4e88a19f
PH
2865 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" (smtp_banner) "
2866 "failed: %s", smtp_banner, expand_string_message);
2867 }
2868else
2869 {
2870 int codelen = 3;
2871 s = user_msg;
4f6ae5c3 2872 smtp_message_code(&code, &codelen, &s, NULL, TRUE);
d6a96edc 2873 if (codelen > 4)
4e88a19f
PH
2874 {
2875 esc = code + 4;
2876 esclen = codelen - 4;
2877 }
2878 }
059ec3d9
PH
2879
2880/* Remove any terminating newlines; might as well remove trailing space too */
2881
2882p = s + Ustrlen(s);
2883while (p > s && isspace(p[-1])) p--;
2884*p = 0;
2885
2886/* It seems that CC:Mail is braindead, and assumes that the greeting message
2887is all contained in a single IP packet. The original code wrote out the
2888greeting using several calls to fprint/fputc, and on busy servers this could
2889cause it to be split over more than one packet - which caused CC:Mail to fall
2890over when it got the second part of the greeting after sending its first
2891command. Sigh. To try to avoid this, build the complete greeting message
2892first, and output it in one fell swoop. This gives a better chance of it
2893ending up as a single packet. */
2894
acec9514 2895ss = string_get(256);
059ec3d9
PH
2896
2897p = s;
2898do /* At least once, in case we have an empty string */
2899 {
2900 int len;
2901 uschar *linebreak = Ustrchr(p, '\n');
acec9514 2902 ss = string_catn(ss, code, 3);
db57e575 2903 if (!linebreak)
059ec3d9
PH
2904 {
2905 len = Ustrlen(p);
acec9514 2906 ss = string_catn(ss, US" ", 1);
059ec3d9
PH
2907 }
2908 else
2909 {
2910 len = linebreak - p;
acec9514 2911 ss = string_catn(ss, US"-", 1);
059ec3d9 2912 }
acec9514
JH
2913 ss = string_catn(ss, esc, esclen);
2914 ss = string_catn(ss, p, len);
2915 ss = string_catn(ss, US"\r\n", 2);
059ec3d9 2916 p += len;
db57e575 2917 if (linebreak) p++;
059ec3d9 2918 }
db57e575 2919while (*p);
059ec3d9 2920
059ec3d9
PH
2921/* Before we write the banner, check that there is no input pending, unless
2922this synchronisation check is disabled. */
2923
a14e5636 2924if (!check_sync())
059ec3d9 2925 {
40525d07
JH
2926 unsigned n = smtp_inend - smtp_inptr;
2927 if (n > 32) n = 32;
2928
a14e5636
PH
2929 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol "
2930 "synchronization error (input sent without waiting for greeting): "
2931 "rejected connection from %s input=\"%s\"", host_and_ident(TRUE),
40525d07 2932 string_printing(string_copyn(smtp_inptr, n)));
925ac8e4 2933 smtp_printf("554 SMTP synchronization error\r\n", FALSE);
a14e5636 2934 return FALSE;
059ec3d9
PH
2935 }
2936
2937/* Now output the banner */
2938
acec9514 2939smtp_printf("%s", FALSE, string_from_gstring(ss));
a2673768
JH
2940
2941/* Attempt to see if we sent the banner before the last ACK of the 3-way
2942handshake arrived. If so we must have managed a TFO. */
2943
2944#ifdef TCP_FASTOPEN
2945tfo_in_check();
2946#endif
2947
059ec3d9
PH
2948return TRUE;
2949}
2950
2951
2952
2953
2954
2955/*************************************************
2956* Handle SMTP syntax and protocol errors *
2957*************************************************/
2958
2959/* Write to the log for SMTP syntax errors in incoming commands, if configured
2960to do so. Then transmit the error response. The return value depends on the
2961number of syntax and protocol errors in this SMTP session.
2962
2963Arguments:
2964 type error type, given as a log flag bit
2965 code response code; <= 0 means don't send a response
2966 data data to reflect in the response (can be NULL)
2967 errmess the error message
2968
2969Returns: -1 limit of syntax/protocol errors NOT exceeded
2970 +1 limit of syntax/protocol errors IS exceeded
2971
2972These values fit in with the values of the "done" variable in the main
2973processing loop in smtp_setup_msg(). */
2974
2975static int
2976synprot_error(int type, int code, uschar *data, uschar *errmess)
2977{
2978int yield = -1;
2979
2980log_write(type, LOG_MAIN, "SMTP %s error in \"%s\" %s %s",
2981 (type == L_smtp_syntax_error)? "syntax" : "protocol",
3ee512ff 2982 string_printing(smtp_cmd_buffer), host_and_ident(TRUE), errmess);
059ec3d9
PH
2983
2984if (++synprot_error_count > smtp_max_synprot_errors)
2985 {
2986 yield = 1;
2987 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
2988 "syntax or protocol errors (last command was \"%s\")",
0ebc4d69 2989 host_and_ident(FALSE), string_printing(smtp_cmd_buffer));
059ec3d9
PH
2990 }
2991
2992if (code > 0)
2993 {
925ac8e4
JH
2994 smtp_printf("%d%c%s%s%s\r\n", FALSE, code, yield == 1 ? '-' : ' ',
2995 data ? data : US"", data ? US": " : US"", errmess);
059ec3d9 2996 if (yield == 1)
925ac8e4 2997 smtp_printf("%d Too many syntax or protocol errors\r\n", FALSE, code);
059ec3d9
PH
2998 }
2999
3000return yield;
3001}
3002
3003
3004
3005
3006/*************************************************
059ec3d9
PH
3007* Send SMTP response, possibly multiline *
3008*************************************************/
3009
3010/* There are, it seems, broken clients out there that cannot handle multiline
3011responses. If no_multiline_responses is TRUE (it can be set from an ACL), we
3012output nothing for non-final calls, and only the first line for anything else.
3013
3014Arguments:
a5bd321b 3015 code SMTP code, may involve extended status codes
d6a96edc 3016 codelen length of smtp code; if > 4 there's an ESC
059ec3d9
PH
3017 final FALSE if the last line isn't the final line
3018 msg message text, possibly containing newlines
3019
3020Returns: nothing
3021*/
3022
3023void
a5bd321b 3024smtp_respond(uschar* code, int codelen, BOOL final, uschar *msg)
059ec3d9 3025{
a5bd321b
PH
3026int esclen = 0;
3027uschar *esc = US"";
3028
059ec3d9
PH
3029if (!final && no_multiline_responses) return;
3030
d6a96edc 3031if (codelen > 4)
a5bd321b
PH
3032 {
3033 esc = code + 4;
3034 esclen = codelen - 4;
3035 }
3036
2679d413
PH
3037/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
3038have had the same. Note: this code is also present in smtp_printf(). It would
3039be tidier to have it only in one place, but when it was added, it was easier to
3040do it that way, so as not to have to mess with the code for the RCPT command,
3041which sometimes uses smtp_printf() and sometimes smtp_respond(). */
3042
3043if (rcpt_in_progress)
3044 {
3045 if (rcpt_smtp_response == NULL)
3046 rcpt_smtp_response = string_copy(msg);
3047 else if (rcpt_smtp_response_same &&
3048 Ustrcmp(rcpt_smtp_response, msg) != 0)
3049 rcpt_smtp_response_same = FALSE;
3050 rcpt_in_progress = FALSE;
3051 }
3052
e5de01f0 3053/* Now output the message, splitting it up into multiple lines if necessary.
925ac8e4
JH
3054We only handle pipelining these responses as far as nonfinal/final groups,
3055not the whole MAIL/RCPT/DATA response set. */
2679d413 3056
059ec3d9
PH
3057for (;;)
3058 {
3059 uschar *nl = Ustrchr(msg, '\n');
3060 if (nl == NULL)
3061 {
925ac8e4 3062 smtp_printf("%.3s%c%.*s%s\r\n", !final, code, final ? ' ':'-', esclen, esc, msg);
059ec3d9
PH
3063 return;
3064 }
3065 else if (nl[1] == 0 || no_multiline_responses)
3066 {
925ac8e4 3067 smtp_printf("%.3s%c%.*s%.*s\r\n", !final, code, final ? ' ':'-', esclen, esc,
a5bd321b 3068 (int)(nl - msg), msg);
059ec3d9
PH
3069 return;
3070 }
3071 else
3072 {
925ac8e4 3073 smtp_printf("%.3s-%.*s%.*s\r\n", TRUE, code, esclen, esc, (int)(nl - msg), msg);
059ec3d9
PH
3074 msg = nl + 1;
3075 while (isspace(*msg)) msg++;
3076 }
3077 }
3078}
3079
3080
3081
3082
3083/*************************************************
4e88a19f
PH
3084* Parse user SMTP message *
3085*************************************************/
3086
3087/* This function allows for user messages overriding the response code details
3088by providing a suitable response code string at the start of the message
3089user_msg. Check the message for starting with a response code and optionally an
3090extended status code. If found, check that the first digit is valid, and if so,
3091change the code pointer and length to use the replacement. An invalid code
3092causes a panic log; in this case, if the log messages is the same as the user
3093message, we must also adjust the value of the log message to show the code that
3094is actually going to be used (the original one).
3095
3096This function is global because it is called from receive.c as well as within
3097this module.
3098
d6a96edc
PH
3099Note that the code length returned includes the terminating whitespace
3100character, which is always included in the regex match.
3101
4e88a19f
PH
3102Arguments:
3103 code SMTP code, may involve extended status codes
d6a96edc 3104 codelen length of smtp code; if > 4 there's an ESC
4e88a19f
PH
3105 msg message text
3106 log_msg optional log message, to be adjusted with the new SMTP code
4f6ae5c3 3107 check_valid if true, verify the response code
4e88a19f
PH
3108
3109Returns: nothing
3110*/
3111
3112void
4f6ae5c3
JH
3113smtp_message_code(uschar **code, int *codelen, uschar **msg, uschar **log_msg,
3114 BOOL check_valid)
4e88a19f
PH
3115{
3116int n;
3117int ovector[3];
3118
4f6ae5c3 3119if (!msg || !*msg) return;
4e88a19f 3120
4f6ae5c3
JH
3121if ((n = pcre_exec(regex_smtp_code, NULL, CS *msg, Ustrlen(*msg), 0,
3122 PCRE_EOPT, ovector, sizeof(ovector)/sizeof(int))) < 0) return;
4e88a19f 3123
4f6ae5c3 3124if (check_valid && (*msg)[0] != (*code)[0])
4e88a19f
PH
3125 {
3126 log_write(0, LOG_MAIN|LOG_PANIC, "configured error code starts with "
3127 "incorrect digit (expected %c) in \"%s\"", (*code)[0], *msg);
3128 if (log_msg != NULL && *log_msg == *msg)
3129 *log_msg = string_sprintf("%s %s", *code, *log_msg + ovector[1]);
3130 }
3131else
3132 {
3133 *code = *msg;
3134 *codelen = ovector[1]; /* Includes final space */
3135 }
3136*msg += ovector[1]; /* Chop the code off the message */
3137return;
3138}
3139
3140
3141
3142
3143/*************************************************
059ec3d9
PH
3144* Handle an ACL failure *
3145*************************************************/
3146
3147/* This function is called when acl_check() fails. As well as calls from within
3148this module, it is called from receive.c for an ACL after DATA. It sorts out
5b6f7658 3149logging the incident, and sends the error response. A message containing
059ec3d9
PH
3150newlines is turned into a multiline SMTP response, but for logging, only the
3151first line is used.
3152
a5bd321b
PH
3153There's a table of default permanent failure response codes to use in
3154globals.c, along with the table of names. VFRY is special. Despite RFC1123 it
3155defaults disabled in Exim. However, discussion in connection with RFC 821bis
3156(aka RFC 2821) has concluded that the response should be 252 in the disabled
3157state, because there are broken clients that try VRFY before RCPT. A 5xx
3158response should be given only when the address is positively known to be
4f6ae5c3
JH
3159undeliverable. Sigh. We return 252 if there is no VRFY ACL or it provides
3160no explicit code, but if there is one we let it know best.
3161Also, for ETRN, 458 is given on refusal, and for AUTH, 503.
a5bd321b
PH
3162
3163From Exim 4.63, it is possible to override the response code details by
3164providing a suitable response code string at the start of the message provided
3165in user_msg. The code's first digit is checked for validity.
059ec3d9
PH
3166
3167Arguments:
4f6ae5c3
JH
3168 where where the ACL was called from
3169 rc the failure code
3170 user_msg a message that can be included in an SMTP response
3171 log_msg a message for logging
059ec3d9
PH
3172
3173Returns: 0 in most cases
3174 2 if the failure code was FAIL_DROP, in which case the
3175 SMTP connection should be dropped (this value fits with the
3176 "done" variable in smtp_setup_msg() below)
3177*/
3178
3179int
3180smtp_handle_acl_fail(int where, int rc, uschar *user_msg, uschar *log_msg)
3181{
059ec3d9 3182BOOL drop = rc == FAIL_DROP;
a5bd321b 3183int codelen = 3;
a5bd321b 3184uschar *smtp_code;
059ec3d9
PH
3185uschar *lognl;
3186uschar *sender_info = US"";
64ffc24f 3187uschar *what =
8523533c 3188#ifdef WITH_CONTENT_SCAN
3cc3f762 3189 where == ACL_WHERE_MIME ? US"during MIME ACL checks" :
8e669ac1 3190#endif
3cc3f762
JH
3191 where == ACL_WHERE_PREDATA ? US"DATA" :
3192 where == ACL_WHERE_DATA ? US"after DATA" :
8ccd00b1 3193#ifndef DISABLE_PRDR
3cc3f762 3194 where == ACL_WHERE_PRDR ? US"after DATA PRDR" :
fd98a5c6 3195#endif
3cc3f762
JH
3196 smtp_cmd_data ?
3197 string_sprintf("%s %s", acl_wherenames[where], smtp_cmd_data) :
3198 string_sprintf("%s in \"connect\" ACL", acl_wherenames[where]);
059ec3d9
PH
3199
3200if (drop) rc = FAIL;
3201
4e88a19f 3202/* Set the default SMTP code, and allow a user message to change it. */
a5bd321b 3203
4f6ae5c3
JH
3204smtp_code = rc == FAIL ? acl_wherecodes[where] : US"451";
3205smtp_message_code(&smtp_code, &codelen, &user_msg, &log_msg,
3206 where != ACL_WHERE_VRFY);
a5bd321b 3207
059ec3d9
PH
3208/* We used to have sender_address here; however, there was a bug that was not
3209updating sender_address after a rewrite during a verify. When this bug was
3210fixed, sender_address at this point became the rewritten address. I'm not sure
3211this is what should be logged, so I've changed to logging the unrewritten
3212address to retain backward compatibility. */
3213
8523533c 3214#ifndef WITH_CONTENT_SCAN
059ec3d9 3215if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA)
8523533c
TK
3216#else
3217if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA || where == ACL_WHERE_MIME)
3218#endif
059ec3d9 3219 {
b98bb9ac
PP
3220 sender_info = string_sprintf("F=<%s>%s%s%s%s ",
3221 sender_address_unrewritten ? sender_address_unrewritten : sender_address,
3222 sender_host_authenticated ? US" A=" : US"",
3223 sender_host_authenticated ? sender_host_authenticated : US"",
3224 sender_host_authenticated && authenticated_id ? US":" : US"",
3225 sender_host_authenticated && authenticated_id ? authenticated_id : US""
3226 );
059ec3d9
PH
3227 }
3228
3229/* If there's been a sender verification failure with a specific message, and
3230we have not sent a response about it yet, do so now, as a preliminary line for
278c6e6c
PH
3231failures, but not defers. However, always log it for defer, and log it for fail
3232unless the sender_verify_fail log selector has been turned off. */
059ec3d9 3233
02b41d71 3234if (sender_verified_failed &&
059ec3d9
PH
3235 !testflag(sender_verified_failed, af_sverify_told))
3236 {
2679d413
PH
3237 BOOL save_rcpt_in_progress = rcpt_in_progress;
3238 rcpt_in_progress = FALSE; /* So as not to treat these as the error */
3239
059ec3d9
PH
3240 setflag(sender_verified_failed, af_sverify_told);
3241
6c6d6e48 3242 if (rc != FAIL || LOGGING(sender_verify_fail))
278c6e6c
PH
3243 log_write(0, LOG_MAIN|LOG_REJECT, "%s sender verify %s for <%s>%s",
3244 host_and_ident(TRUE),
3245 ((sender_verified_failed->special_action & 255) == DEFER)? "defer":"fail",
3246 sender_verified_failed->address,
3247 (sender_verified_failed->message == NULL)? US"" :
3248 string_sprintf(": %s", sender_verified_failed->message));
059ec3d9 3249
02b41d71 3250 if (rc == FAIL && sender_verified_failed->user_message)
a5bd321b 3251 smtp_respond(smtp_code, codelen, FALSE, string_sprintf(
059ec3d9
PH
3252 testflag(sender_verified_failed, af_verify_pmfail)?
3253 "Postmaster verification failed while checking <%s>\n%s\n"
3254 "Several RFCs state that you are required to have a postmaster\n"
3255 "mailbox for each mail domain. This host does not accept mail\n"
3256 "from domains whose servers reject the postmaster address."
3257 :
3258 testflag(sender_verified_failed, af_verify_nsfail)?
3259 "Callback setup failed while verifying <%s>\n%s\n"
3260 "The initial connection, or a HELO or MAIL FROM:<> command was\n"
3261 "rejected. Refusing MAIL FROM:<> does not help fight spam, disregards\n"
3262 "RFC requirements, and stops you from receiving standard bounce\n"
3263 "messages. This host does not accept mail from domains whose servers\n"
3264 "refuse bounces."
3265 :
3266 "Verification failed for <%s>\n%s",
3267 sender_verified_failed->address,
3268 sender_verified_failed->user_message));
2679d413
PH
3269
3270 rcpt_in_progress = save_rcpt_in_progress;
059ec3d9
PH
3271 }
3272
3273/* Sort out text for logging */
3274
3cc3f762
JH
3275log_msg = log_msg ? string_sprintf(": %s", log_msg) : US"";
3276if ((lognl = Ustrchr(log_msg, '\n'))) *lognl = 0;
059ec3d9
PH
3277
3278/* Send permanent failure response to the command, but the code used isn't
3279always a 5xx one - see comments at the start of this function. If the original
3280rc was FAIL_DROP we drop the connection and yield 2. */
3281
ff5929e3
JH
3282if (rc == FAIL)
3283 smtp_respond(smtp_code, codelen, TRUE,
3284 user_msg ? user_msg : US"Administrative prohibition");
059ec3d9
PH
3285
3286/* Send temporary failure response to the command. Don't give any details,
3287unless acl_temp_details is set. This is TRUE for a callout defer, a "defer"
3288verb, and for a header verify when smtp_return_error_details is set.
3289
3290This conditional logic is all somewhat of a mess because of the odd
3291interactions between temp_details and return_error_details. One day it should
3292be re-implemented in a tidier fashion. */
3293
3294else
ff5929e3 3295 if (acl_temp_details && user_msg)
059ec3d9 3296 {
ff5929e3
JH
3297 if ( smtp_return_error_details
3298 && sender_verified_failed
3299 && sender_verified_failed->message
3300 )
a5bd321b 3301 smtp_respond(smtp_code, codelen, FALSE, sender_verified_failed->message);
ff5929e3 3302
a5bd321b 3303 smtp_respond(smtp_code, codelen, TRUE, user_msg);
059ec3d9
PH
3304 }
3305 else
a5bd321b
PH
3306 smtp_respond(smtp_code, codelen, TRUE,
3307 US"Temporary local problem - please try later");
059ec3d9 3308
6ea85e9a
PH
3309/* Log the incident to the logs that are specified by log_reject_target
3310(default main, reject). This can be empty to suppress logging of rejections. If
3311the connection is not forcibly to be dropped, return 0. Otherwise, log why it
3312is closing if required and return 2. */
059ec3d9 3313
6ea85e9a 3314if (log_reject_target != 0)
887291d2 3315 {
e45a1c37 3316#ifdef SUPPORT_TLS
acec9514
JH
3317 gstring * g = s_tlslog(NULL);
3318 uschar * tls = string_from_gstring(g);
fc16abb4 3319 if (!tls) tls = US"";
e45a1c37 3320#else
fc16abb4 3321 uschar * tls = US"";
e45a1c37 3322#endif
3cc3f762
JH
3323 log_write(where == ACL_WHERE_CONNECT ? L_connection_reject : 0,
3324 log_reject_target, "%s%s%s %s%srejected %s%s",
fc16abb4
JH
3325 LOGGING(dnssec) && sender_host_dnssec ? US" DS" : US"",
3326 host_and_ident(TRUE),
3327 tls,
3328 sender_info,
3329 rc == FAIL ? US"" : US"temporarily ",
3330 what, log_msg);
887291d2 3331 }
059ec3d9
PH
3332
3333if (!drop) return 0;
3334
3335log_write(L_smtp_connection, LOG_MAIN, "%s closed by DROP in ACL",
3336 smtp_get_connection_info());
8f128379
PH
3337
3338/* Run the not-quit ACL, but without any custom messages. This should not be a
3339problem, because we get here only if some other ACL has issued "drop", and
3340in that case, *its* custom messages will have been used above. */
3341
3342smtp_notquit_exit(US"acl-drop", NULL, NULL);
059ec3d9
PH
3343return 2;
3344}
3345
3346
3347
3348
3349/*************************************************
8f128379
PH
3350* Handle SMTP exit when QUIT is not given *
3351*************************************************/
3352
3353/* This function provides a logging/statistics hook for when an SMTP connection
3354is dropped on the floor or the other end goes away. It's a global function
3355because it's called from receive.c as well as this module. As well as running
3356the NOTQUIT ACL, if there is one, this function also outputs a final SMTP
3357response, either with a custom message from the ACL, or using a default. There
3358is one case, however, when no message is output - after "drop". In that case,
3359the ACL that obeyed "drop" has already supplied the custom message, and NULL is
3360passed to this function.
3361
3362In case things go wrong while processing this function, causing an error that
4c04137d 3363may re-enter this function, there is a recursion check.
8f128379
PH
3364
3365Arguments:
3366 reason What $smtp_notquit_reason will be set to in the ACL;
3367 if NULL, the ACL is not run
3368 code The error code to return as part of the response
3369 defaultrespond The default message if there's no user_msg
3370
3371Returns: Nothing
3372*/
3373
3374void
3375smtp_notquit_exit(uschar *reason, uschar *code, uschar *defaultrespond, ...)
3376{
3377int rc;
3378uschar *user_msg = NULL;
3379uschar *log_msg = NULL;
3380
3381/* Check for recursive acll */
3382
3383if (smtp_exit_function_called)
3384 {
3385 log_write(0, LOG_PANIC, "smtp_notquit_exit() called more than once (%s)",
3386 reason);
3387 return;
3388 }
3389smtp_exit_function_called = TRUE;
3390
3391/* Call the not-QUIT ACL, if there is one, unless no reason is given. */
3392
eea0defe 3393if (acl_smtp_notquit && reason)
8f128379
PH
3394 {
3395 smtp_notquit_reason = reason;
eea0defe
JB
3396 if ((rc = acl_check(ACL_WHERE_NOTQUIT, NULL, acl_smtp_notquit, &user_msg,
3397 &log_msg)) == ERROR)
8f128379
PH
3398 log_write(0, LOG_MAIN|LOG_PANIC, "ACL for not-QUIT returned ERROR: %s",
3399 log_msg);
3400 }
3401
3402/* Write an SMTP response if we are expected to give one. As the default
3403responses are all internal, they should always fit in the buffer, but code a
3404warning, just in case. Note that string_vformat() still leaves a complete
3405string, even if it is incomplete. */
3406
eea0defe 3407if (code && defaultrespond)
8f128379 3408 {
eea0defe
JB
3409 if (user_msg)
3410 smtp_respond(code, 3, TRUE, user_msg);
3411 else
8f128379
PH
3412 {
3413 uschar buffer[128];
3414 va_list ap;
3415 va_start(ap, defaultrespond);
3416 if (!string_vformat(buffer, sizeof(buffer), CS defaultrespond, ap))
3417 log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_notquit_exit()");
925ac8e4 3418 smtp_printf("%s %s\r\n", FALSE, code, buffer);
8f128379
PH
3419 va_end(ap);
3420 }
8f128379
PH
3421 mac_smtp_fflush();
3422 }
3423}
3424
3425
3426
3427
3428/*************************************************
d7b47fd0
PH
3429* Verify HELO argument *
3430*************************************************/
3431
3432/* This function is called if helo_verify_hosts or helo_try_verify_hosts is
3433matched. It is also called from ACL processing if verify = helo is used and
3434verification was not previously tried (i.e. helo_try_verify_hosts was not
3435matched). The result of its processing is to set helo_verified and
3436helo_verify_failed. These variables should both be FALSE for this function to
3437be called.
3438
3439Note that EHLO/HELO is legitimately allowed to quote an address literal. Allow
3440for IPv6 ::ffff: literals.
3441
3442Argument: none
3443Returns: TRUE if testing was completed;
3444 FALSE on a temporary failure
3445*/
3446
3447BOOL
3448smtp_verify_helo(void)
3449{
3450BOOL yield = TRUE;
3451
3452HDEBUG(D_receive) debug_printf("verifying EHLO/HELO argument \"%s\"\n",
3453 sender_helo_name);
3454
3455if (sender_helo_name == NULL)
3456 {
3457 HDEBUG(D_receive) debug_printf("no EHLO/HELO command was issued\n");
3458 }
3459
d1d5595c
PH
3460/* Deal with the case of -bs without an IP address */
3461
3462else if (sender_host_address == NULL)
3463 {
3464 HDEBUG(D_receive) debug_printf("no client IP address: assume success\n");
3465 helo_verified = TRUE;
3466 }
3467
3468/* Deal with the more common case when there is a sending IP address */
3469
d7b47fd0
PH
3470else if (sender_helo_name[0] == '[')
3471 {
3472 helo_verified = Ustrncmp(sender_helo_name+1, sender_host_address,
3473 Ustrlen(sender_host_address)) == 0;
3474
3475 #if HAVE_IPV6
3476 if (!helo_verified)
3477 {
3478 if (strncmpic(sender_host_address, US"::ffff:", 7) == 0)
3479 helo_verified = Ustrncmp(sender_helo_name + 1,
3480 sender_host_address + 7, Ustrlen(sender_host_address) - 7) == 0;
3481 }
3482 #endif
3483
3484 HDEBUG(D_receive)
3485 { if (helo_verified) debug_printf("matched host address\n"); }
3486 }
3487
3488/* Do a reverse lookup if one hasn't already given a positive or negative
3489response. If that fails, or the name doesn't match, try checking with a forward
3490lookup. */
3491
3492else
3493 {
3494 if (sender_host_name == NULL && !host_lookup_failed)
3495 yield = host_name_lookup() != DEFER;
3496
3497 /* If a host name is known, check it and all its aliases. */
3498
1705dd20
JH
3499 if (sender_host_name)
3500 if ((helo_verified = strcmpic(sender_host_name, sender_helo_name) == 0))
d7b47fd0 3501 {
1705dd20 3502 sender_helo_dnssec = sender_host_dnssec;
d7b47fd0
PH
3503 HDEBUG(D_receive) debug_printf("matched host name\n");
3504 }
3505 else
3506 {
3507 uschar **aliases = sender_host_aliases;
1705dd20
JH
3508 while (*aliases)
3509 if ((helo_verified = strcmpic(*aliases++, sender_helo_name) == 0))
3510 {
3511 sender_helo_dnssec = sender_host_dnssec;
3512 break;
3513 }
3514
3515 HDEBUG(D_receive) if (helo_verified)
d7b47fd0 3516 debug_printf("matched alias %s\n", *(--aliases));
d7b47fd0 3517 }
d7b47fd0
PH
3518
3519 /* Final attempt: try a forward lookup of the helo name */
3520
3521 if (!helo_verified)
3522 {
3523 int rc;
3524 host_item h;
1705dd20
JH
3525 dnssec_domains d;
3526 host_item *hh;
3527
d7b47fd0
PH
3528 h.name = sender_helo_name;
3529 h.address = NULL;
3530 h.mx = MX_NONE;
3531 h.next = NULL;
1705dd20
JH
3532 d.request = US"*";
3533 d.require = US"";
3534
d7b47fd0
PH
3535 HDEBUG(D_receive) debug_printf("getting IP address for %s\n",
3536 sender_helo_name);
66387a73 3537 rc = host_find_bydns(&h, NULL, HOST_FIND_BY_A | HOST_FIND_BY_AAAA,
1705dd20 3538 NULL, NULL, NULL, &d, NULL, NULL);
d7b47fd0 3539 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
1705dd20 3540 for (hh = &h; hh; hh = hh->next)
d7b47fd0
PH
3541 if (Ustrcmp(hh->address, sender_host_address) == 0)
3542 {
3543 helo_verified = TRUE;
1705dd20 3544 if (h.dnssec == DS_YES) sender_helo_dnssec = TRUE;
d7b47fd0 3545 HDEBUG(D_receive)
1705dd20
JH
3546 {
3547 debug_printf("IP address for %s matches calling address\n"
3548 "Forward DNS security status: %sverified\n",
3549 sender_helo_name, sender_helo_dnssec ? "" : "un");
3550 }
d7b47fd0
PH
3551 break;
3552 }
d7b47fd0
PH
3553 }
3554 }
3555
d1d5595c 3556if (!helo_verified) helo_verify_failed = TRUE; /* We've tried ... */
d7b47fd0
PH
3557return yield;
3558}
3559
3560
3561
3562
3563/*************************************************
4e88a19f
PH
3564* Send user response message *
3565