DMARC: add variables to list of those now-unused at the tail of the SMTP per-message...
[exim.git] / src / src / smtp_in.c
CommitLineData
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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
d27f98fe
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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);
f4630439
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362return FALSE;
363}
364
925ac8e4
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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
f4630439
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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
0d81dabc
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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
JH
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
JH
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
7e3ce68e
JH
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)
7e3ce68e
JH
529Returns: the next character or ERR, EOD or EOF
530*/
531
532int
bd8fbe36 533bdat_getc(unsigned lim)
7e3ce68e
JH
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
JH
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
JH
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
JH
560 unsigned n = smtp_inend - smtp_inptr;
561 if (n > 32) n = 32;
562
f4630439
JH
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),
9e0ed81f
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
e04bfa34
JH
1998dkim_cur_signer = dkim_signers = NULL;
1999dkim_disable_verify = dkim_collect_input = FALSE;
f7572e5a 2000#endif
aa368db3
JH
2001dsn_ret = 0;
2002dsn_envid = NULL;
90341c71 2003deliver_host = deliver_host_address = NULL; /* Can be set by ACL */
aa368db3
JH
2004#ifndef DISABLE_PRDR
2005prdr_requested = FALSE;
2006#endif
7952eef9 2007#ifdef SUPPORT_SPF
e04bfa34 2008spf_header_comment = spf_received = spf_result = spf_smtp_comment = NULL;
8523533c 2009#endif
c780096c
JH
2010#ifdef EXPERIMENTAL_DMARC
2011dmarc_has_been_checked = dmarc_disable_verify = dmarc_enable_forensic = FALSE;
2012dmarc_ar_header = dmarc_domain_policy = dmarc_forensic_sender =
2013dmarc_history_file = dmarc_status = dmarc_status_text =
2014dmarc_tld_file = dmarc_used_domain = NULL;
2015#endif
93c931f8
JH
2016#ifdef EXPERIMENTAL_ARC
2017arc_state = arc_state_reason = NULL;
2018#endif
8c5d388a 2019#ifdef SUPPORT_I18N
d1a13eea
JH
2020message_smtputf8 = FALSE;
2021#endif
059ec3d9
PH
2022body_linecount = body_zerocount = 0;
2023
870f6ba8
TF
2024sender_rate = sender_rate_limit = sender_rate_period = NULL;
2025ratelimiters_mail = NULL; /* Updated by ratelimit ACL condition */
2026 /* Note that ratelimiters_conn persists across resets. */
2027
38a0a95f 2028/* Reset message ACL variables */
47ca6d6c 2029
38a0a95f 2030acl_var_m = NULL;
059ec3d9
PH
2031
2032/* The message body variables use malloc store. They may be set if this is
2033not the first message in an SMTP session and the previous message caused them
2034to be referenced in an ACL. */
2035
90341c71 2036if (message_body)
059ec3d9
PH
2037 {
2038 store_free(message_body);
2039 message_body = NULL;
2040 }
2041
90341c71 2042if (message_body_end)
059ec3d9
PH
2043 {
2044 store_free(message_body_end);
2045 message_body_end = NULL;
2046 }
2047
2048/* Warning log messages are also saved in malloc store. They are saved to avoid
2049repetition in the same message, but it seems right to repeat them for different
4e88a19f 2050messages. */
059ec3d9 2051
90341c71 2052while (acl_warn_logged)
059ec3d9
PH
2053 {
2054 string_item *this = acl_warn_logged;
2055 acl_warn_logged = acl_warn_logged->next;
2056 store_free(this);
2057 }
90341c71 2058store_reset(reset_point);
059ec3d9
PH
2059}
2060
2061
2062
2063
2064
2065/*************************************************
2066* Initialize for incoming batched SMTP message *
2067*************************************************/
2068
2069/* This function is called from smtp_setup_msg() in the case when
2070smtp_batched_input is true. This happens when -bS is used to pass a whole batch
2071of messages in one file with SMTP commands between them. All errors must be
2072reported by sending a message, and only MAIL FROM, RCPT TO, and DATA are
2073relevant. After an error on a sender, or an invalid recipient, the remainder
2074of the message is skipped. The value of received_protocol is already set.
2075
2076Argument: none
2077Returns: > 0 message successfully started (reached DATA)
2078 = 0 QUIT read or end of file reached
2079 < 0 should not occur
2080*/
2081
2082static int
2083smtp_setup_batch_msg(void)
2084{
2085int done = 0;
2086void *reset_point = store_get(0);
2087
2088/* Save the line count at the start of each transaction - single commands
2089like HELO and RSET count as whole transactions. */
2090
2091bsmtp_transaction_linecount = receive_linecount;
2092
2093if ((receive_feof)()) return 0; /* Treat EOF as QUIT */
2094
57cc2785 2095cancel_cutthrough_connection(TRUE, US"smtp_setup_batch_msg");
059ec3d9
PH
2096smtp_reset(reset_point); /* Reset for start of message */
2097
2098/* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
2099value. The values are 2 larger than the required yield of the function. */
2100
2101while (done <= 0)
2102 {
2103 uschar *errmess;
2104 uschar *recipient = NULL;
2105 int start, end, sender_domain, recipient_domain;
2106
bd8fbe36 2107 switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED))
059ec3d9
PH
2108 {
2109 /* The HELO/EHLO commands set sender_address_helo if they have
2110 valid data; otherwise they are ignored, except that they do
2111 a reset of the state. */
2112
2113 case HELO_CMD:
2114 case EHLO_CMD:
2115
db57e575
JH
2116 check_helo(smtp_cmd_data);
2117 /* Fall through */
059ec3d9
PH
2118
2119 case RSET_CMD:
db57e575
JH
2120 cancel_cutthrough_connection(TRUE, US"RSET received");
2121 smtp_reset(reset_point);
2122 bsmtp_transaction_linecount = receive_linecount;
2123 break;
059ec3d9
PH
2124
2125
2126 /* The MAIL FROM command requires an address as an operand. All we
2127 do here is to parse it for syntactic correctness. The form "<>" is
2128 a special case which converts into an empty string. The start/end
2129 pointers in the original are not used further for this address, as
2130 it is the canonical extracted address which is all that is kept. */
2131
2132 case MAIL_CMD:
db57e575
JH
2133 smtp_mailcmd_count++; /* Count for no-mail log */
2134 if (sender_address != NULL)
2135 /* The function moan_smtp_batch() does not return. */
2136 moan_smtp_batch(smtp_cmd_buffer, "503 Sender already given");
059ec3d9 2137
db57e575
JH
2138 if (smtp_cmd_data[0] == 0)
2139 /* The function moan_smtp_batch() does not return. */
2140 moan_smtp_batch(smtp_cmd_buffer, "501 MAIL FROM must have an address operand");
059ec3d9 2141
db57e575 2142 /* Reset to start of message */
059ec3d9 2143
db57e575
JH
2144 cancel_cutthrough_connection(TRUE, US"MAIL received");
2145 smtp_reset(reset_point);
059ec3d9 2146
db57e575 2147 /* Apply SMTP rewrite */
059ec3d9 2148
db57e575
JH
2149 raw_sender = ((rewrite_existflags & rewrite_smtp) != 0)?
2150 rewrite_one(smtp_cmd_data, rewrite_smtp|rewrite_smtp_sender, NULL, FALSE,
2151 US"", global_rewrite_rules) : smtp_cmd_data;
059ec3d9 2152
db57e575 2153 /* Extract the address; the TRUE flag allows <> as valid */
059ec3d9 2154
db57e575
JH
2155 raw_sender =
2156 parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain,
2157 TRUE);
059ec3d9 2158
db57e575
JH
2159 if (!raw_sender)
2160 /* The function moan_smtp_batch() does not return. */
2161 moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
059ec3d9 2162
db57e575 2163 sender_address = string_copy(raw_sender);
059ec3d9 2164
db57e575 2165 /* Qualify unqualified sender addresses if permitted to do so. */
059ec3d9 2166
db57e575
JH
2167 if ( !sender_domain
2168 && sender_address[0] != 0 && sender_address[0] != '@')
2169 if (allow_unqualified_sender)
2170 {
2171 sender_address = rewrite_address_qualify(sender_address, FALSE);
2172 DEBUG(D_receive) debug_printf("unqualified address %s accepted "
2173 "and rewritten\n", raw_sender);
2174 }
2175 /* The function moan_smtp_batch() does not return. */
2176 else
2177 moan_smtp_batch(smtp_cmd_buffer, "501 sender address must contain "
2178 "a domain");
2179 break;
059ec3d9
PH
2180
2181
2182 /* The RCPT TO command requires an address as an operand. All we do
2183 here is to parse it for syntactic correctness. There may be any number
2184 of RCPT TO commands, specifying multiple senders. We build them all into
2185 a data structure that is in argc/argv format. The start/end values
2186 given by parse_extract_address are not used, as we keep only the
2187 extracted address. */
2188
2189 case RCPT_CMD:
db57e575
JH
2190 if (!sender_address)
2191 /* The function moan_smtp_batch() does not return. */
2192 moan_smtp_batch(smtp_cmd_buffer, "503 No sender yet given");
059ec3d9 2193
db57e575
JH
2194 if (smtp_cmd_data[0] == 0)
2195 /* The function moan_smtp_batch() does not return. */
2196 moan_smtp_batch(smtp_cmd_buffer,
2197 "501 RCPT TO must have an address operand");
059ec3d9 2198
db57e575 2199 /* Check maximum number allowed */
059ec3d9 2200
db57e575
JH
2201 if (recipients_max > 0 && recipients_count + 1 > recipients_max)
2202 /* The function moan_smtp_batch() does not return. */
2203 moan_smtp_batch(smtp_cmd_buffer, "%s too many recipients",
2204 recipients_max_reject? "552": "452");
059ec3d9 2205
db57e575
JH
2206 /* Apply SMTP rewrite, then extract address. Don't allow "<>" as a
2207 recipient address */
059ec3d9 2208
db57e575
JH
2209 recipient = rewrite_existflags & rewrite_smtp
2210 ? rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
2211 global_rewrite_rules)
2212 : smtp_cmd_data;
059ec3d9 2213
db57e575
JH
2214 recipient = parse_extract_address(recipient, &errmess, &start, &end,
2215 &recipient_domain, FALSE);
059ec3d9 2216
db57e575
JH
2217 if (!recipient)
2218 /* The function moan_smtp_batch() does not return. */
2219 moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
059ec3d9 2220
db57e575
JH
2221 /* If the recipient address is unqualified, qualify it if permitted. Then
2222 add it to the list of recipients. */
059ec3d9 2223
db57e575
JH
2224 if (!recipient_domain)
2225 if (allow_unqualified_recipient)
2226 {
2227 DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
2228 recipient);
2229 recipient = rewrite_address_qualify(recipient, TRUE);
2230 }
2231 /* The function moan_smtp_batch() does not return. */
2232 else
2233 moan_smtp_batch(smtp_cmd_buffer,
2234 "501 recipient address must contain a domain");
2235
2236 receive_add_recipient(recipient, -1);
2237 break;
059ec3d9
PH
2238
2239
2240 /* The DATA command is legal only if it follows successful MAIL FROM
2241 and RCPT TO commands. This function is complete when a valid DATA
2242 command is encountered. */
2243
2244 case DATA_CMD:
db57e575
JH
2245 if (!sender_address || recipients_count <= 0)
2246 /* The function moan_smtp_batch() does not return. */
2247 if (!sender_address)
2248 moan_smtp_batch(smtp_cmd_buffer,
2249 "503 MAIL FROM:<sender> command must precede DATA");
2250 else
2251 moan_smtp_batch(smtp_cmd_buffer,
2252 "503 RCPT TO:<recipient> must precede DATA");
059ec3d9 2253 else
db57e575
JH
2254 {
2255 done = 3; /* DATA successfully achieved */
2256 message_ended = END_NOTENDED; /* Indicate in middle of message */
2257 }
2258 break;
059ec3d9
PH
2259
2260
2261 /* The VRFY, EXPN, HELP, ETRN, and NOOP commands are ignored. */
2262
2263 case VRFY_CMD:
2264 case EXPN_CMD:
2265 case HELP_CMD:
2266 case NOOP_CMD:
2267 case ETRN_CMD:
db57e575
JH
2268 bsmtp_transaction_linecount = receive_linecount;
2269 break;
059ec3d9
PH
2270
2271
2272 case EOF_CMD:
2273 case QUIT_CMD:
db57e575
JH
2274 done = 2;
2275 break;
059ec3d9
PH
2276
2277
2278 case BADARG_CMD:
db57e575
JH
2279 /* The function moan_smtp_batch() does not return. */
2280 moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected argument data");
2281 break;
059ec3d9
PH
2282
2283
2284 case BADCHAR_CMD:
db57e575
JH
2285 /* The function moan_smtp_batch() does not return. */
2286 moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected NULL in SMTP command");
2287 break;
059ec3d9
PH
2288
2289
2290 default:
db57e575
JH
2291 /* The function moan_smtp_batch() does not return. */
2292 moan_smtp_batch(smtp_cmd_buffer, "500 Command unrecognized");
2293 break;
059ec3d9
PH
2294 }
2295 }
2296
2297return done - 2; /* Convert yield values */
2298}
2299
2300
2301
2302
cf0c6164
JH
2303static BOOL
2304smtp_log_tls_fail(uschar * errstr)
2305{
2306uschar * conn_info = smtp_get_connection_info();
2307
2308if (Ustrncmp(conn_info, US"SMTP ", 5) == 0) conn_info += 5;
2309/* I'd like to get separated H= here, but too hard for now */
2310
2311log_write(0, LOG_MAIN, "TLS error on %s %s", conn_info, errstr);
2312return FALSE;
2313}
2314
2315
a2673768
JH
2316
2317
2318#ifdef TCP_FASTOPEN
2319static void
2320tfo_in_check(void)
2321{
2322# ifdef TCP_INFO
2323struct tcp_info tinfo;
2324socklen_t len = sizeof(tinfo);
2325
2326if ( getsockopt(fileno(smtp_out), IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0
2327 && tinfo.tcpi_state == TCP_SYN_RECV
2328 )
2329 {
1ccd5f67 2330 DEBUG(D_receive) debug_printf("TCP_FASTOPEN mode connection (state TCP_SYN_RECV)\n");
a2673768
JH
2331 tcp_in_fastopen = TRUE;
2332 }
2333# endif
2334}
2335#endif
2336
2337
059ec3d9
PH
2338/*************************************************
2339* Start an SMTP session *
2340*************************************************/
2341
2342/* This function is called at the start of an SMTP session. Thereafter,
2343smtp_setup_msg() is called to initiate each separate message. This
2344function does host-specific testing, and outputs the banner line.
2345
2346Arguments: none
2347Returns: FALSE if the session can not continue; something has
2348 gone wrong, or the connection to the host is blocked
2349*/
2350
2351BOOL
2352smtp_start_session(void)
2353{
acec9514 2354int esclen;
4e88a19f
PH
2355uschar *user_msg, *log_msg;
2356uschar *code, *esc;
acec9514
JH
2357uschar *p, *s;
2358gstring * ss;
059ec3d9 2359
0f1a8658 2360gettimeofday(&smtp_connection_start, NULL);
b4ed4da0
PH
2361for (smtp_ch_index = 0; smtp_ch_index < SMTP_HBUFF_SIZE; smtp_ch_index++)
2362 smtp_connection_had[smtp_ch_index] = SCH_NONE;
2363smtp_ch_index = 0;
2364
00f00ca5
PH
2365/* Default values for certain variables */
2366
059ec3d9 2367helo_seen = esmtp = helo_accept_junk = FALSE;
b4ed4da0 2368smtp_mailcmd_count = 0;
059ec3d9
PH
2369count_nonmail = TRUE_UNSET;
2370synprot_error_count = unknown_command_count = nonmail_command_count = 0;
2371smtp_delay_mail = smtp_rlm_base;
2372auth_advertised = FALSE;
2373pipelining_advertised = FALSE;
cf8b11a5 2374pipelining_enable = TRUE;
059ec3d9 2375sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING;
8f128379 2376smtp_exit_function_called = FALSE; /* For avoiding loop in not-quit exit */
059ec3d9 2377
33d73e3b
PH
2378/* If receiving by -bs from a trusted user, or testing with -bh, we allow
2379authentication settings from -oMaa to remain in force. */
2380
c44ff8be
JH
2381if (!host_checking && !sender_host_notsocket)
2382 sender_host_auth_pubname = sender_host_authenticated = NULL;
059ec3d9
PH
2383authenticated_by = NULL;
2384
2385#ifdef SUPPORT_TLS
817d9f57 2386tls_in.cipher = tls_in.peerdn = NULL;
9d1c15ef
JH
2387tls_in.ourcert = tls_in.peercert = NULL;
2388tls_in.sni = NULL;
44662487 2389tls_in.ocsp = OCSP_NOT_REQ;
059ec3d9
PH
2390tls_advertised = FALSE;
2391#endif
6c1c3d1d 2392dsn_advertised = FALSE;
8c5d388a 2393#ifdef SUPPORT_I18N
d1a13eea
JH
2394smtputf8_advertised = FALSE;
2395#endif
059ec3d9
PH
2396
2397/* Reset ACL connection variables */
2398
38a0a95f 2399acl_var_c = NULL;
059ec3d9 2400
ca86f471 2401/* Allow for trailing 0 in the command and data buffers. */
3ee512ff 2402
bd8fbe36 2403if (!(smtp_cmd_buffer = US malloc(2*SMTP_CMD_BUFFER_SIZE + 2)))
059ec3d9
PH
2404 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2405 "malloc() failed for SMTP command buffer");
40c90bca 2406
2416c261 2407smtp_cmd_buffer[0] = 0;
bd8fbe36 2408smtp_data_buffer = smtp_cmd_buffer + SMTP_CMD_BUFFER_SIZE + 1;
059ec3d9
PH
2409
2410/* For batched input, the protocol setting can be overridden from the
2411command line by a trusted caller. */
2412
2413if (smtp_batched_input)
2414 {
40c90bca 2415 if (!received_protocol) received_protocol = US"local-bsmtp";
059ec3d9
PH
2416 }
2417
2418/* For non-batched SMTP input, the protocol setting is forced here. It will be
2419reset later if any of EHLO/AUTH/STARTTLS are received. */
2420
2421else
2422 received_protocol =
e524074d 2423 (sender_host_address ? protocols : protocols_local) [pnormal];
059ec3d9
PH
2424
2425/* Set up the buffer for inputting using direct read() calls, and arrange to
ecce6d9a
JH
2426call the local functions instead of the standard C ones. Place a NUL at the
2427end of the buffer to safety-stop C-string reads from it. */
059ec3d9 2428
5903c6ff 2429if (!(smtp_inbuffer = US malloc(IN_BUFFER_SIZE)))
059ec3d9 2430 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "malloc() failed for SMTP input buffer");
ecce6d9a 2431smtp_inbuffer[IN_BUFFER_SIZE-1] = '\0';
40c90bca 2432
059ec3d9 2433receive_getc = smtp_getc;
0d81dabc 2434receive_getbuf = smtp_getbuf;
584e96c6 2435receive_get_cache = smtp_get_cache;
059ec3d9
PH
2436receive_ungetc = smtp_ungetc;
2437receive_feof = smtp_feof;
2438receive_ferror = smtp_ferror;
58eb016e 2439receive_smtp_buffered = smtp_buffered;
059ec3d9
PH
2440smtp_inptr = smtp_inend = smtp_inbuffer;
2441smtp_had_eof = smtp_had_error = 0;
2442
2443/* Set up the message size limit; this may be host-specific */
2444
d45b1de8 2445thismessage_size_limit = expand_string_integer(message_size_limit, TRUE);
db57e575 2446if (expand_string_message)
059ec3d9
PH
2447 {
2448 if (thismessage_size_limit == -1)
2449 log_write(0, LOG_MAIN|LOG_PANIC, "unable to expand message_size_limit: "
2450 "%s", expand_string_message);
2451 else
2452 log_write(0, LOG_MAIN|LOG_PANIC, "invalid message_size_limit: "
2453 "%s", expand_string_message);
2454 smtp_closedown(US"Temporary local problem - please try later");
2455 return FALSE;
2456 }
2457
2458/* When a message is input locally via the -bs or -bS options, sender_host_
2459unknown is set unless -oMa was used to force an IP address, in which case it
2460is checked like a real remote connection. When -bs is used from inetd, this
2461flag is not set, causing the sending host to be checked. The code that deals
2462with IP source routing (if configured) is never required for -bs or -bS and
2463the flag sender_host_notsocket is used to suppress it.
2464
2465If smtp_accept_max and smtp_accept_reserve are set, keep some connections in
2466reserve for certain hosts and/or networks. */
2467
2468if (!sender_host_unknown)
2469 {
2470 int rc;
2471 BOOL reserved_host = FALSE;
2472
2473 /* Look up IP options (source routing info) on the socket if this is not an
2474 -oMa "host", and if any are found, log them and drop the connection.
2475
2476 Linux (and others now, see below) is different to everyone else, so there
2477 has to be some conditional compilation here. Versions of Linux before 2.1.15
2478 used a structure whose name was "options". Somebody finally realized that
2479 this name was silly, and it got changed to "ip_options". I use the
2480 newer name here, but there is a fudge in the script that sets up os.h
2481 to define a macro in older Linux systems.
2482
2483 Sigh. Linux is a fast-moving target. Another generation of Linux uses
2484 glibc 2, which has chosen ip_opts for the structure name. This is now
2485 really a glibc thing rather than a Linux thing, so the condition name
2486 has been changed to reflect this. It is relevant also to GNU/Hurd.
2487
2488 Mac OS 10.x (Darwin) is like the later glibc versions, but without the
2489 setting of the __GLIBC__ macro, so we can't detect it automatically. There's
2490 a special macro defined in the os.h file.
2491
2492 Some DGUX versions on older hardware appear not to support IP options at
2493 all, so there is now a general macro which can be set to cut out this
2494 support altogether.
2495
2496 How to do this properly in IPv6 is not yet known. */
2497
2498 #if !HAVE_IPV6 && !defined(NO_IP_OPTIONS)
2499
2500 #ifdef GLIBC_IP_OPTIONS
2501 #if (!defined __GLIBC__) || (__GLIBC__ < 2)
2502 #define OPTSTYLE 1
2503 #else
2504 #define OPTSTYLE 2
2505 #endif
2506 #elif defined DARWIN_IP_OPTIONS
2507 #define OPTSTYLE 2
2508 #else
2509 #define OPTSTYLE 3
2510 #endif
2511
2512 if (!host_checking && !sender_host_notsocket)
2513 {
2514 #if OPTSTYLE == 1
36a3b041 2515 EXIM_SOCKLEN_T optlen = sizeof(struct ip_options) + MAX_IPOPTLEN;
059ec3d9
PH
2516 struct ip_options *ipopt = store_get(optlen);
2517 #elif OPTSTYLE == 2
2518 struct ip_opts ipoptblock;
2519 struct ip_opts *ipopt = &ipoptblock;
36a3b041 2520 EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
059ec3d9
PH
2521 #else
2522 struct ipoption ipoptblock;
2523 struct ipoption *ipopt = &ipoptblock;
36a3b041 2524 EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
059ec3d9
PH
2525 #endif
2526
2527 /* Occasional genuine failures of getsockopt() have been seen - for
2528 example, "reset by peer". Therefore, just log and give up on this
2529 call, unless the error is ENOPROTOOPT. This error is given by systems
2530 that have the interfaces but not the mechanism - e.g. GNU/Hurd at the time
2531 of writing. So for that error, carry on - we just can't do an IP options
2532 check. */
2533
2534 DEBUG(D_receive) debug_printf("checking for IP options\n");
2535
5903c6ff 2536 if (getsockopt(fileno(smtp_out), IPPROTO_IP, IP_OPTIONS, US (ipopt),
059ec3d9
PH
2537 &optlen) < 0)
2538 {
2539 if (errno != ENOPROTOOPT)
2540 {
2541 log_write(0, LOG_MAIN, "getsockopt() failed from %s: %s",
2542 host_and_ident(FALSE), strerror(errno));
925ac8e4 2543 smtp_printf("451 SMTP service not available\r\n", FALSE);
059ec3d9
PH
2544 return FALSE;
2545 }
2546 }
2547
2548 /* Deal with any IP options that are set. On the systems I have looked at,
2549 the value of MAX_IPOPTLEN has been 40, meaning that there should never be
2550 more logging data than will fit in big_buffer. Nevertheless, after somebody
2551 questioned this code, I've added in some paranoid checking. */
2552
2553 else if (optlen > 0)
2554 {
2555 uschar *p = big_buffer;
2556 uschar *pend = big_buffer + big_buffer_size;
2557 uschar *opt, *adptr;
2558 int optcount;
2559 struct in_addr addr;
2560
2561 #if OPTSTYLE == 1
5903c6ff 2562 uschar *optstart = US (ipopt->__data);
059ec3d9 2563 #elif OPTSTYLE == 2
5903c6ff 2564 uschar *optstart = US (ipopt->ip_opts);
059ec3d9 2565 #else
5903c6ff 2566 uschar *optstart = US (ipopt->ipopt_list);
059ec3d9
PH
2567 #endif
2568
2569 DEBUG(D_receive) debug_printf("IP options exist\n");
2570
2571 Ustrcpy(p, "IP options on incoming call:");
2572 p += Ustrlen(p);
2573
2574 for (opt = optstart; opt != NULL &&
5903c6ff 2575 opt < US (ipopt) + optlen;)
059ec3d9
PH
2576 {
2577 switch (*opt)
2578 {
2579 case IPOPT_EOL:
2580 opt = NULL;
2581 break;
2582
2583 case IPOPT_NOP:
2584 opt++;
2585 break;
2586
2587 case IPOPT_SSRR:
2588 case IPOPT_LSRR:
2589 if (!string_format(p, pend-p, " %s [@%s",
2590 (*opt == IPOPT_SSRR)? "SSRR" : "LSRR",
2591 #if OPTSTYLE == 1
2592 inet_ntoa(*((struct in_addr *)(&(ipopt->faddr))))))
2593 #elif OPTSTYLE == 2
2594 inet_ntoa(ipopt->ip_dst)))
2595 #else
2596 inet_ntoa(ipopt->ipopt_dst)))
2597 #endif
2598 {
2599 opt = NULL;
2600 break;
2601 }
2602
2603 p += Ustrlen(p);
2604 optcount = (opt[1] - 3) / sizeof(struct in_addr);
2605 adptr = opt + 3;
2606 while (optcount-- > 0)
2607 {
2608 memcpy(&addr, adptr, sizeof(addr));
2609 if (!string_format(p, pend - p - 1, "%s%s",
2610 (optcount == 0)? ":" : "@", inet_ntoa(addr)))
2611 {
2612 opt = NULL;
2613 break;
2614 }
2615 p += Ustrlen(p);
2616 adptr += sizeof(struct in_addr);
2617 }
2618 *p++ = ']';
2619 opt += opt[1];
2620 break;
2621
2622 default:
2623 {
2624 int i;
2625 if (pend - p < 4 + 3*opt[1]) { opt = NULL; break; }
2626 Ustrcat(p, "[ ");
2627 p += 2;
2628 for (i = 0; i < opt[1]; i++)
5976eb99 2629 p += sprintf(CS p, "%2.2x ", opt[i]);
059ec3d9
PH
2630 *p++ = ']';
2631 }
2632 opt += opt[1];
2633 break;
2634 }
2635 }
2636
2637 *p = 0;
2638 log_write(0, LOG_MAIN, "%s", big_buffer);
2639
2640 /* Refuse any call with IP options. This is what tcpwrappers 7.5 does. */
2641
2642 log_write(0, LOG_MAIN|LOG_REJECT,
2643 "connection from %s refused (IP options)", host_and_ident(FALSE));
2644
925ac8e4 2645 smtp_printf("554 SMTP service not available\r\n", FALSE);
059ec3d9
PH
2646 return FALSE;
2647 }
2648
2649 /* Length of options = 0 => there are no options */
2650
2651 else DEBUG(D_receive) debug_printf("no IP options found\n");
2652 }
2653 #endif /* HAVE_IPV6 && !defined(NO_IP_OPTIONS) */
2654
2655 /* Set keep-alive in socket options. The option is on by default. This
2656 setting is an attempt to get rid of some hanging connections that stick in
2657 read() when the remote end (usually a dialup) goes away. */
2658
2659 if (smtp_accept_keepalive && !sender_host_notsocket)
2660 ip_keepalive(fileno(smtp_out), sender_host_address, FALSE);
2661
2662 /* If the current host matches host_lookup, set the name by doing a
2663 reverse lookup. On failure, sender_host_name will be NULL and
2664 host_lookup_failed will be TRUE. This may or may not be serious - optional
2665 checks later. */
2666
2667 if (verify_check_host(&host_lookup) == OK)
2668 {
2669 (void)host_name_lookup();
2670 host_build_sender_fullhost();
2671 }
2672
2673 /* Delay this until we have the full name, if it is looked up. */
2674
2675 set_process_info("handling incoming connection from %s",
2676 host_and_ident(FALSE));
2677
1ad6489e
JH
2678 /* Expand smtp_receive_timeout, if needed */
2679
2680 if (smtp_receive_timeout_s)
2681 {
2682 uschar * exp;
2683 if ( !(exp = expand_string(smtp_receive_timeout_s))
2684 || !(*exp)
2685 || (smtp_receive_timeout = readconf_readtime(exp, 0, FALSE)) < 0
2686 )
2687 log_write(0, LOG_MAIN|LOG_PANIC,
2688 "bad value for smtp_receive_timeout: '%s'", exp ? exp : US"");
2689 }
2690
059ec3d9
PH
2691 /* Test for explicit connection rejection */
2692
2693 if (verify_check_host(&host_reject_connection) == OK)
2694 {
2695 log_write(L_connection_reject, LOG_MAIN|LOG_REJECT, "refused connection "
2696 "from %s (host_reject_connection)", host_and_ident(FALSE));
925ac8e4 2697 smtp_printf("554 SMTP service not available\r\n", FALSE);
059ec3d9
PH
2698 return FALSE;
2699 }
2700
afb3eaaf
PH
2701 /* Test with TCP Wrappers if so configured. There is a problem in that
2702 hosts_ctl() returns 0 (deny) under a number of system failure circumstances,
2703 such as disks dying. In these cases, it is desirable to reject with a 4xx
2704 error instead of a 5xx error. There isn't a "right" way to detect such
2705 problems. The following kludge is used: errno is zeroed before calling
2706 hosts_ctl(). If the result is "reject", a 5xx error is given only if the
2707 value of errno is 0 or ENOENT (which happens if /etc/hosts.{allow,deny} does
2708 not exist). */
059ec3d9 2709
1811cb4c 2710#ifdef USE_TCP_WRAPPERS
afb3eaaf 2711 errno = 0;
1811cb4c 2712 if (!(tcp_wrappers_name = expand_string(tcp_wrappers_daemon_name)))
5dc43717
JJ
2713 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" "
2714 "(tcp_wrappers_name) failed: %s", string_printing(tcp_wrappers_name),
2715 expand_string_message);
1811cb4c 2716
5dc43717 2717 if (!hosts_ctl(tcp_wrappers_name,
1811cb4c
JH
2718 sender_host_name ? CS sender_host_name : STRING_UNKNOWN,
2719 sender_host_address ? CS sender_host_address : STRING_UNKNOWN,
2720 sender_ident ? CS sender_ident : STRING_UNKNOWN))
059ec3d9 2721 {
afb3eaaf
PH
2722 if (errno == 0 || errno == ENOENT)
2723 {
2724 HDEBUG(D_receive) debug_printf("tcp wrappers rejection\n");
2725 log_write(L_connection_reject,
2726 LOG_MAIN|LOG_REJECT, "refused connection from %s "
2727 "(tcp wrappers)", host_and_ident(FALSE));
925ac8e4 2728 smtp_printf("554 SMTP service not available\r\n", FALSE);
afb3eaaf
PH
2729 }
2730 else
2731 {
2732 int save_errno = errno;
2733 HDEBUG(D_receive) debug_printf("tcp wrappers rejected with unexpected "
2734 "errno value %d\n", save_errno);
2735 log_write(L_connection_reject,
2736 LOG_MAIN|LOG_REJECT, "temporarily refused connection from %s "
2737 "(tcp wrappers errno=%d)", host_and_ident(FALSE), save_errno);
925ac8e4 2738 smtp_printf("451 Temporary local problem - please try later\r\n", FALSE);
afb3eaaf 2739 }
059ec3d9
PH
2740 return FALSE;
2741 }
1811cb4c 2742#endif
059ec3d9 2743
b01dd148
PH
2744 /* Check for reserved slots. The value of smtp_accept_count has already been
2745 incremented to include this process. */
059ec3d9
PH
2746
2747 if (smtp_accept_max > 0 &&
b01dd148 2748 smtp_accept_count > smtp_accept_max - smtp_accept_reserve)
059ec3d9
PH
2749 {
2750 if ((rc = verify_check_host(&smtp_reserve_hosts)) != OK)
2751 {
2752 log_write(L_connection_reject,
2753 LOG_MAIN, "temporarily refused connection from %s: not in "
2754 "reserve list: connected=%d max=%d reserve=%d%s",
b01dd148 2755 host_and_ident(FALSE), smtp_accept_count - 1, smtp_accept_max,
059ec3d9
PH
2756 smtp_accept_reserve, (rc == DEFER)? " (lookup deferred)" : "");
2757 smtp_printf("421 %s: Too many concurrent SMTP connections; "
925ac8e4 2758 "please try again later\r\n", FALSE, smtp_active_hostname);
059ec3d9
PH
2759 return FALSE;
2760 }
2761 reserved_host = TRUE;
2762 }
2763
2764 /* If a load level above which only messages from reserved hosts are
2765 accepted is set, check the load. For incoming calls via the daemon, the
2766 check is done in the superior process if there are no reserved hosts, to
2767 save a fork. In all cases, the load average will already be available
2768 in a global variable at this point. */
2769
2770 if (smtp_load_reserve >= 0 &&
2771 load_average > smtp_load_reserve &&
2772 !reserved_host &&
2773 verify_check_host(&smtp_reserve_hosts) != OK)
2774 {
2775 log_write(L_connection_reject,
2776 LOG_MAIN, "temporarily refused connection from %s: not in "
2777 "reserve list and load average = %.2f", host_and_ident(FALSE),
2778 (double)load_average/1000.0);
925ac8e4 2779 smtp_printf("421 %s: Too much load; please try again later\r\n", FALSE,
059ec3d9
PH
2780 smtp_active_hostname);
2781 return FALSE;
2782 }
2783
2784 /* Determine whether unqualified senders or recipients are permitted
2785 for this host. Unfortunately, we have to do this every time, in order to
2786 set the flags so that they can be inspected when considering qualifying
2787 addresses in the headers. For a site that permits no qualification, this
2788 won't take long, however. */
2789
2790 allow_unqualified_sender =
2791 verify_check_host(&sender_unqualified_hosts) == OK;
2792
2793 allow_unqualified_recipient =
2794 verify_check_host(&recipient_unqualified_hosts) == OK;
2795
2796 /* Determine whether HELO/EHLO is required for this host. The requirement
2797 can be hard or soft. */
2798
2799 helo_required = verify_check_host(&helo_verify_hosts) == OK;
2800 if (!helo_required)
2801 helo_verify = verify_check_host(&helo_try_verify_hosts) == OK;
2802
2803 /* Determine whether this hosts is permitted to send syntactic junk
2804 after a HELO or EHLO command. */
2805
2806 helo_accept_junk = verify_check_host(&helo_accept_junk_hosts) == OK;
2807 }
2808
2809/* For batch SMTP input we are now done. */
2810
2811if (smtp_batched_input) return TRUE;
2812
a3c86431
TL
2813/* If valid Proxy Protocol source is connecting, set up session.
2814 * Failure will not allow any SMTP function other than QUIT. */
1811cb4c
JH
2815
2816#ifdef SUPPORT_PROXY
a3c86431
TL
2817proxy_session = FALSE;
2818proxy_session_failed = FALSE;
2819if (check_proxy_protocol_host())
1811cb4c
JH
2820 setup_proxy_protocol_host();
2821#endif
2822
2823 /* Start up TLS if tls_on_connect is set. This is for supporting the legacy
2824 smtps port for use with older style SSL MTAs. */
2825
2826#ifdef SUPPORT_TLS
69d8eed7
JH
2827 if (tls_in.on_connect)
2828 {
2829 if (tls_server_start(tls_require_ciphers, &user_msg) != OK)
2830 return smtp_log_tls_fail(user_msg);
2831 cmd_list[CMD_LIST_TLS_AUTH].is_mail_cmd = TRUE;
2832 }
a3c86431
TL
2833#endif
2834
1811cb4c 2835/* Run the connect ACL if it exists */
059ec3d9 2836
4e88a19f 2837user_msg = NULL;
3cc3f762 2838if (acl_smtp_connect)
059ec3d9
PH
2839 {
2840 int rc;
3cc3f762
JH
2841 if ((rc = acl_check(ACL_WHERE_CONNECT, NULL, acl_smtp_connect, &user_msg,
2842 &log_msg)) != OK)
059ec3d9 2843 {
3cc3f762 2844 (void) smtp_handle_acl_fail(ACL_WHERE_CONNECT, rc, user_msg, log_msg);
059ec3d9
PH
2845 return FALSE;
2846 }
2847 }
2848
2849/* Output the initial message for a two-way SMTP connection. It may contain
2850newlines, which then cause a multi-line response to be given. */
2851
4e88a19f
PH
2852code = US"220"; /* Default status code */
2853esc = US""; /* Default extended status code */
2854esclen = 0; /* Length of esc */
2855
d4ff61d1 2856if (!user_msg)
4e88a19f 2857 {
d4ff61d1 2858 if (!(s = expand_string(smtp_banner)))
4e88a19f
PH
2859 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" (smtp_banner) "
2860 "failed: %s", smtp_banner, expand_string_message);
2861 }
2862else
2863 {
2864 int codelen = 3;
2865 s = user_msg;
4f6ae5c3 2866 smtp_message_code(&code, &codelen, &s, NULL, TRUE);
d6a96edc 2867 if (codelen > 4)
4e88a19f
PH
2868 {
2869 esc = code + 4;
2870 esclen = codelen - 4;
2871 }
2872 }
059ec3d9
PH
2873
2874/* Remove any terminating newlines; might as well remove trailing space too */
2875
2876p = s + Ustrlen(s);
2877while (p > s && isspace(p[-1])) p--;
2878*p = 0;
2879
2880/* It seems that CC:Mail is braindead, and assumes that the greeting message
2881is all contained in a single IP packet. The original code wrote out the
2882greeting using several calls to fprint/fputc, and on busy servers this could
2883cause it to be split over more than one packet - which caused CC:Mail to fall
2884over when it got the second part of the greeting after sending its first
2885command. Sigh. To try to avoid this, build the complete greeting message
2886first, and output it in one fell swoop. This gives a better chance of it
2887ending up as a single packet. */
2888
acec9514 2889ss = string_get(256);
059ec3d9
PH
2890
2891p = s;
2892do /* At least once, in case we have an empty string */
2893 {
2894 int len;
2895 uschar *linebreak = Ustrchr(p, '\n');
acec9514 2896 ss = string_catn(ss, code, 3);
db57e575 2897 if (!linebreak)
059ec3d9
PH
2898 {
2899 len = Ustrlen(p);
acec9514 2900 ss = string_catn(ss, US" ", 1);
059ec3d9
PH
2901 }
2902 else
2903 {
2904 len = linebreak - p;
acec9514 2905 ss = string_catn(ss, US"-", 1);
059ec3d9 2906 }
acec9514
JH
2907 ss = string_catn(ss, esc, esclen);
2908 ss = string_catn(ss, p, len);
2909 ss = string_catn(ss, US"\r\n", 2);
059ec3d9 2910 p += len;
db57e575 2911 if (linebreak) p++;
059ec3d9 2912 }
db57e575 2913while (*p);
059ec3d9 2914
059ec3d9
PH
2915/* Before we write the banner, check that there is no input pending, unless
2916this synchronisation check is disabled. */
2917
a14e5636 2918if (!check_sync())
059ec3d9 2919 {
40525d07
JH
2920 unsigned n = smtp_inend - smtp_inptr;
2921 if (n > 32) n = 32;
2922
a14e5636
PH
2923 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol "
2924 "synchronization error (input sent without waiting for greeting): "
2925 "rejected connection from %s input=\"%s\"", host_and_ident(TRUE),
40525d07 2926 string_printing(string_copyn(smtp_inptr, n)));
925ac8e4 2927 smtp_printf("554 SMTP synchronization error\r\n", FALSE);
a14e5636 2928 return FALSE;
059ec3d9
PH
2929 }
2930
2931/* Now output the banner */
2932
acec9514 2933smtp_printf("%s", FALSE, string_from_gstring(ss));
a2673768
JH
2934
2935/* Attempt to see if we sent the banner before the last ACK of the 3-way
2936handshake arrived. If so we must have managed a TFO. */
2937
2938#ifdef TCP_FASTOPEN
2939tfo_in_check();
2940#endif
2941
059ec3d9
PH
2942return TRUE;
2943}
2944
2945
2946
2947
2948
2949/*************************************************
2950* Handle SMTP syntax and protocol errors *
2951*************************************************/
2952
2953/* Write to the log for SMTP syntax errors in incoming commands, if configured
2954to do so. Then transmit the error response. The return value depends on the
2955number of syntax and protocol errors in this SMTP session.
2956
2957Arguments:
2958 type error type, given as a log flag bit
2959 code response code; <= 0 means don't send a response
2960 data data to reflect in the response (can be NULL)
2961 errmess the error message
2962
2963Returns: -1 limit of syntax/protocol errors NOT exceeded
2964 +1 limit of syntax/protocol errors IS exceeded
2965
2966These values fit in with the values of the "done" variable in the main
2967processing loop in smtp_setup_msg(). */
2968
2969static int
2970synprot_error(int type, int code, uschar *data, uschar *errmess)
2971{
2972int yield = -1;
2973
2974log_write(type, LOG_MAIN, "SMTP %s error in \"%s\" %s %s",
2975 (type == L_smtp_syntax_error)? "syntax" : "protocol",
3ee512ff 2976 string_printing(smtp_cmd_buffer), host_and_ident(TRUE), errmess);
059ec3d9
PH
2977
2978if (++synprot_error_count > smtp_max_synprot_errors)
2979 {
2980 yield = 1;
2981 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
2982 "syntax or protocol errors (last command was \"%s\")",
0ebc4d69 2983 host_and_ident(FALSE), string_printing(smtp_cmd_buffer));
059ec3d9
PH
2984 }
2985
2986if (code > 0)
2987 {
925ac8e4
JH
2988 smtp_printf("%d%c%s%s%s\r\n", FALSE, code, yield == 1 ? '-' : ' ',
2989 data ? data : US"", data ? US": " : US"", errmess);
059ec3d9 2990 if (yield == 1)
925ac8e4 2991 smtp_printf("%d Too many syntax or protocol errors\r\n", FALSE, code);
059ec3d9
PH
2992 }
2993
2994return yield;
2995}
2996
2997
2998
2999
3000/*************************************************
059ec3d9
PH
3001* Send SMTP response, possibly multiline *
3002*************************************************/
3003
3004/* There are, it seems, broken clients out there that cannot handle multiline
3005responses. If no_multiline_responses is TRUE (it can be set from an ACL), we
3006output nothing for non-final calls, and only the first line for anything else.
3007
3008Arguments:
a5bd321b 3009 code SMTP code, may involve extended status codes
d6a96edc 3010 codelen length of smtp code; if > 4 there's an ESC
059ec3d9
PH
3011 final FALSE if the last line isn't the final line
3012 msg message text, possibly containing newlines
3013
3014Returns: nothing
3015*/
3016
3017void
a5bd321b 3018smtp_respond(uschar* code, int codelen, BOOL final, uschar *msg)
059ec3d9 3019{
a5bd321b
PH
3020int esclen = 0;
3021uschar *esc = US"";
3022
059ec3d9
PH
3023if (!final && no_multiline_responses) return;
3024
d6a96edc 3025if (codelen > 4)
a5bd321b
PH
3026 {
3027 esc = code + 4;
3028 esclen = codelen - 4;
3029 }
3030
2679d413
PH
3031/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
3032have had the same. Note: this code is also present in smtp_printf(). It would
3033be tidier to have it only in one place, but when it was added, it was easier to
3034do it that way, so as not to have to mess with the code for the RCPT command,
3035which sometimes uses smtp_printf() and sometimes smtp_respond(). */
3036
3037if (rcpt_in_progress)
3038 {
3039 if (rcpt_smtp_response == NULL)
3040 rcpt_smtp_response = string_copy(msg);
3041 else if (rcpt_smtp_response_same &&
3042 Ustrcmp(rcpt_smtp_response, msg) != 0)
3043 rcpt_smtp_response_same = FALSE;
3044 rcpt_in_progress = FALSE;
3045 }
3046
e5de01f0 3047/* Now output the message, splitting it up into multiple lines if necessary.
925ac8e4
JH
3048We only handle pipelining these responses as far as nonfinal/final groups,
3049not the whole MAIL/RCPT/DATA response set. */
2679d413 3050
059ec3d9
PH
3051for (;;)
3052 {
3053 uschar *nl = Ustrchr(msg, '\n');
3054 if (nl == NULL)
3055 {
925ac8e4 3056 smtp_printf("%.3s%c%.*s%s\r\n", !final, code, final ? ' ':'-', esclen, esc, msg);
059ec3d9
PH
3057 return;
3058 }
3059 else if (nl[1] == 0 || no_multiline_responses)
3060 {
925ac8e4 3061 smtp_printf("%.3s%c%.*s%.*s\r\n", !final, code, final ? ' ':'-', esclen, esc,
a5bd321b 3062 (int)(nl - msg), msg);
059ec3d9
PH
3063 return;
3064 }
3065 else
3066 {
925ac8e4 3067 smtp_printf("%.3s-%.*s%.*s\r\n", TRUE, code, esclen, esc, (int)(nl - msg), msg);
059ec3d9
PH
3068 msg = nl + 1;
3069 while (isspace(*msg)) msg++;
3070 }
3071 }
3072}
3073
3074
3075
3076
3077/*************************************************
4e88a19f
PH
3078* Parse user SMTP message *
3079*************************************************/
3080
3081/* This function allows for user messages overriding the response code details
3082by providing a suitable response code string at the start of the message
3083user_msg. Check the message for starting with a response code and optionally an
3084extended status code. If found, check that the first digit is valid, and if so,
3085change the code pointer and length to use the replacement. An invalid code
3086causes a panic log; in this case, if the log messages is the same as the user
3087message, we must also adjust the value of the log message to show the code that
3088is actually going to be used (the original one).
3089
3090This function is global because it is called from receive.c as well as within
3091this module.
3092
d6a96edc
PH
3093Note that the code length returned includes the terminating whitespace
3094character, which is always included in the regex match.
3095
4e88a19f
PH
3096Arguments:
3097 code SMTP code, may involve extended status codes
d6a96edc 3098 codelen length of smtp code; if > 4 there's an ESC
4e88a19f
PH
3099 msg message text
3100 log_msg optional log message, to be adjusted with the new SMTP code
4f6ae5c3 3101 check_valid if true, verify the response code
4e88a19f
PH
3102
3103Returns: nothing
3104*/
3105
3106void
4f6ae5c3
JH
3107smtp_message_code(uschar **code, int *codelen, uschar **msg, uschar **log_msg,
3108 BOOL check_valid)
4e88a19f
PH
3109{
3110int n;
3111int ovector[3];
3112
4f6ae5c3 3113if (!msg || !*msg) return;
4e88a19f 3114
4f6ae5c3
JH
3115if ((n = pcre_exec(regex_smtp_code, NULL, CS *msg, Ustrlen(*msg), 0,
3116 PCRE_EOPT, ovector, sizeof(ovector)/sizeof(int))) < 0) return;
4e88a19f 3117
4f6ae5c3 3118if (check_valid && (*msg)[0] != (*code)[0])
4e88a19f
PH
3119 {
3120 log_write(0, LOG_MAIN|LOG_PANIC, "configured error code starts with "
3121 "incorrect digit (expected %c) in \"%s\"", (*code)[0], *msg);
3122 if (log_msg != NULL && *log_msg == *msg)
3123 *log_msg = string_sprintf("%s %s", *code, *log_msg + ovector[1]);
3124 }
3125else
3126 {
3127 *code = *msg;
3128 *codelen = ovector[1]; /* Includes final space */
3129 }
3130*msg += ovector[1]; /* Chop the code off the message */
3131return;
3132}
3133
3134
3135
3136
3137/*************************************************
059ec3d9
PH
3138* Handle an ACL failure *
3139*************************************************/
3140
3141/* This function is called when acl_check() fails. As well as calls from within
3142this module, it is called from receive.c for an ACL after DATA. It sorts out
5b6f7658 3143logging the incident, and sends the error response. A message containing
059ec3d9
PH
3144newlines is turned into a multiline SMTP response, but for logging, only the
3145first line is used.
3146
a5bd321b
PH
3147There's a table of default permanent failure response codes to use in
3148globals.c, along with the table of names. VFRY is special. Despite RFC1123 it
3149defaults disabled in Exim. However, discussion in connection with RFC 821bis
3150(aka RFC 2821) has concluded that the response should be 252 in the disabled
3151state, because there are broken clients that try VRFY before RCPT. A 5xx
3152response should be given only when the address is positively known to be
4f6ae5c3
JH
3153undeliverable. Sigh. We return 252 if there is no VRFY ACL or it provides
3154no explicit code, but if there is one we let it know best.
3155Also, for ETRN, 458 is given on refusal, and for AUTH, 503.
a5bd321b
PH
3156
3157From Exim 4.63, it is possible to override the response code details by
3158providing a suitable response code string at the start of the message provided
3159in user_msg. The code's first digit is checked for validity.
059ec3d9
PH
3160
3161Arguments:
4f6ae5c3
JH
3162 where where the ACL was called from
3163 rc the failure code
3164 user_msg a message that can be included in an SMTP response
3165 log_msg a message for logging
059ec3d9
PH
3166
3167Returns: 0 in most cases
3168 2 if the failure code was FAIL_DROP, in which case the
3169 SMTP connection should be dropped (this value fits with the
3170 "done" variable in smtp_setup_msg() below)
3171*/
3172
3173int
3174smtp_handle_acl_fail(int where, int rc, uschar *user_msg, uschar *log_msg)
3175{
059ec3d9 3176BOOL drop = rc == FAIL_DROP;
a5bd321b 3177int codelen = 3;
a5bd321b 3178uschar *smtp_code;
059ec3d9
PH
3179uschar *lognl;
3180uschar *sender_info = US"";
64ffc24f 3181uschar *what =
8523533c 3182#ifdef WITH_CONTENT_SCAN
3cc3f762 3183 where == ACL_WHERE_MIME ? US"during MIME ACL checks" :
8e669ac1 3184#endif
3cc3f762
JH
3185 where == ACL_WHERE_PREDATA ? US"DATA" :
3186 where == ACL_WHERE_DATA ? US"after DATA" :
8ccd00b1 3187#ifndef DISABLE_PRDR
3cc3f762 3188 where == ACL_WHERE_PRDR ? US"after DATA PRDR" :
fd98a5c6 3189#endif
3cc3f762
JH
3190 smtp_cmd_data ?
3191 string_sprintf("%s %s", acl_wherenames[where], smtp_cmd_data) :
3192 string_sprintf("%s in \"connect\" ACL", acl_wherenames[where]);
059ec3d9
PH
3193
3194if (drop) rc = FAIL;
3195
4e88a19f 3196/* Set the default SMTP code, and allow a user message to change it. */
a5bd321b 3197
4f6ae5c3
JH
3198smtp_code = rc == FAIL ? acl_wherecodes[where] : US"451";
3199smtp_message_code(&smtp_code, &codelen, &user_msg, &log_msg,
3200 where != ACL_WHERE_VRFY);
a5bd321b 3201
059ec3d9
PH
3202/* We used to have sender_address here; however, there was a bug that was not
3203updating sender_address after a rewrite during a verify. When this bug was
3204fixed, sender_address at this point became the rewritten address. I'm not sure
3205this is what should be logged, so I've changed to logging the unrewritten
3206address to retain backward compatibility. */
3207
8523533c 3208#ifndef WITH_CONTENT_SCAN
059ec3d9 3209if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA)
8523533c
TK
3210#else
3211if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA || where == ACL_WHERE_MIME)
3212#endif
059ec3d9 3213 {
b98bb9ac
PP
3214 sender_info = string_sprintf("F=<%s>%s%s%s%s ",
3215 sender_address_unrewritten ? sender_address_unrewritten : sender_address,
3216 sender_host_authenticated ? US" A=" : US"",
3217 sender_host_authenticated ? sender_host_authenticated : US"",
3218 sender_host_authenticated && authenticated_id ? US":" : US"",
3219 sender_host_authenticated && authenticated_id ? authenticated_id : US""
3220 );
059ec3d9
PH
3221 }
3222
3223/* If there's been a sender verification failure with a specific message, and
3224we have not sent a response about it yet, do so now, as a preliminary line for
278c6e6c
PH
3225failures, but not defers. However, always log it for defer, and log it for fail
3226unless the sender_verify_fail log selector has been turned off. */
059ec3d9 3227
02b41d71 3228if (sender_verified_failed &&
059ec3d9
PH
3229 !testflag(sender_verified_failed, af_sverify_told))
3230 {
2679d413
PH
3231 BOOL save_rcpt_in_progress = rcpt_in_progress;
3232 rcpt_in_progress = FALSE; /* So as not to treat these as the error */
3233
059ec3d9
PH
3234 setflag(sender_verified_failed, af_sverify_told);
3235
6c6d6e48 3236 if (rc != FAIL || LOGGING(sender_verify_fail))
278c6e6c
PH
3237 log_write(0, LOG_MAIN|LOG_REJECT, "%s sender verify %s for <%s>%s",
3238 host_and_ident(TRUE),
3239 ((sender_verified_failed->special_action & 255) == DEFER)? "defer":"fail",
3240 sender_verified_failed->address,
3241 (sender_verified_failed->message == NULL)? US"" :
3242 string_sprintf(": %s", sender_verified_failed->message));
059ec3d9 3243
02b41d71 3244 if (rc == FAIL && sender_verified_failed->user_message)
a5bd321b 3245 smtp_respond(smtp_code, codelen, FALSE, string_sprintf(
059ec3d9
PH
3246 testflag(sender_verified_failed, af_verify_pmfail)?
3247 "Postmaster verification failed while checking <%s>\n%s\n"
3248 "Several RFCs state that you are required to have a postmaster\n"
3249 "mailbox for each mail domain. This host does not accept mail\n"
3250 "from domains whose servers reject the postmaster address."
3251 :
3252 testflag(sender_verified_failed, af_verify_nsfail)?
3253 "Callback setup failed while verifying <%s>\n%s\n"
3254 "The initial connection, or a HELO or MAIL FROM:<> command was\n"
3255 "rejected. Refusing MAIL FROM:<> does not help fight spam, disregards\n"
3256 "RFC requirements, and stops you from receiving standard bounce\n"
3257 "messages. This host does not accept mail from domains whose servers\n"
3258 "refuse bounces."
3259 :
3260 "Verification failed for <%s>\n%s",
3261 sender_verified_failed->address,
3262 sender_verified_failed->user_message));
2679d413
PH
3263
3264 rcpt_in_progress = save_rcpt_in_progress;
059ec3d9
PH
3265 }
3266
3267/* Sort out text for logging */
3268
3cc3f762
JH
3269log_msg = log_msg ? string_sprintf(": %s", log_msg) : US"";
3270if ((lognl = Ustrchr(log_msg, '\n'))) *lognl = 0;
059ec3d9
PH
3271
3272/* Send permanent failure response to the command, but the code used isn't
3273always a 5xx one - see comments at the start of this function. If the original
3274rc was FAIL_DROP we drop the connection and yield 2. */
3275
ff5929e3
JH
3276if (rc == FAIL)
3277 smtp_respond(smtp_code, codelen, TRUE,
3278 user_msg ? user_msg : US"Administrative prohibition");
059ec3d9
PH
3279
3280/* Send temporary failure response to the command. Don't give any details,
3281unless acl_temp_details is set. This is TRUE for a callout defer, a "defer"
3282verb, and for a header verify when smtp_return_error_details is set.
3283
3284This conditional logic is all somewhat of a mess because of the odd
3285interactions between temp_details and return_error_details. One day it should
3286be re-implemented in a tidier fashion. */
3287
3288else
ff5929e3 3289 if (acl_temp_details && user_msg)
059ec3d9 3290 {
ff5929e3
JH
3291 if ( smtp_return_error_details
3292 && sender_verified_failed
3293 && sender_verified_failed->message
3294 )
a5bd321b 3295 smtp_respond(smtp_code, codelen, FALSE, sender_verified_failed->message);
ff5929e3 3296
a5bd321b 3297 smtp_respond(smtp_code, codelen, TRUE, user_msg);
059ec3d9
PH
3298 }
3299 else
a5bd321b
PH
3300 smtp_respond(smtp_code, codelen, TRUE,
3301 US"Temporary local problem - please try later");
059ec3d9 3302
6ea85e9a
PH
3303/* Log the incident to the logs that are specified by log_reject_target
3304(default main, reject). This can be empty to suppress logging of rejections. If
3305the connection is not forcibly to be dropped, return 0. Otherwise, log why it
3306is closing if required and return 2. */
059ec3d9 3307
6ea85e9a 3308if (log_reject_target != 0)
887291d2 3309 {
e45a1c37 3310#ifdef SUPPORT_TLS
acec9514
JH
3311 gstring * g = s_tlslog(NULL);
3312 uschar * tls = string_from_gstring(g);
fc16abb4 3313 if (!tls) tls = US"";
e45a1c37 3314#else
fc16abb4 3315 uschar * tls = US"";
e45a1c37 3316#endif
3cc3f762
JH
3317 log_write(where == ACL_WHERE_CONNECT ? L_connection_reject : 0,
3318 log_reject_target, "%s%s%s %s%srejected %s%s",
fc16abb4
JH
3319 LOGGING(dnssec) && sender_host_dnssec ? US" DS" : US"",
3320 host_and_ident(TRUE),
3321 tls,
3322 sender_info,
3323 rc == FAIL ? US"" : US"temporarily ",
3324 what, log_msg);
887291d2 3325 }
059ec3d9
PH
3326
3327if (!drop) return 0;
3328
3329log_write(L_smtp_connection, LOG_MAIN, "%s closed by DROP in ACL",
3330 smtp_get_connection_info());
8f128379
PH
3331
3332/* Run the not-quit ACL, but without any custom messages. This should not be a
3333problem, because we get here only if some other ACL has issued "drop", and
3334in that case, *its* custom messages will have been used above. */
3335
3336smtp_notquit_exit(US"acl-drop", NULL, NULL);
059ec3d9
PH
3337return 2;
3338}
3339
3340
3341
3342
3343/*************************************************
8f128379
PH
3344* Handle SMTP exit when QUIT is not given *
3345*************************************************/
3346
3347/* This function provides a logging/statistics hook for when an SMTP connection
3348is dropped on the floor or the other end goes away. It's a global function
3349because it's called from receive.c as well as this module. As well as running
3350the NOTQUIT ACL, if there is one, this function also outputs a final SMTP
3351response, either with a custom message from the ACL, or using a default. There
3352is one case, however, when no message is output - after "drop". In that case,
3353the ACL that obeyed "drop" has already supplied the custom message, and NULL is
3354passed to this function.
3355
3356In case things go wrong while processing this function, causing an error that
4c04137d 3357may re-enter this function, there is a recursion check.
8f128379
PH
3358
3359Arguments:
3360 reason What $smtp_notquit_reason will be set to in the ACL;
3361 if NULL, the ACL is not run
3362 code The error code to return as part of the response
3363 defaultrespond The default message if there's no user_msg
3364
3365Returns: Nothing
3366*/
3367
3368void
3369smtp_notquit_exit(uschar *reason, uschar *code, uschar *defaultrespond, ...)
3370{
3371int rc;
3372uschar *user_msg = NULL;
3373uschar *log_msg = NULL;
3374
3375/* Check for recursive acll */
3376
3377if (smtp_exit_function_called)
3378 {
3379 log_write(0, LOG_PANIC, "smtp_notquit_exit() called more than once (%s)",
3380 reason);
3381 return;
3382 }
3383smtp_exit_function_called = TRUE;
3384
3385/* Call the not-QUIT ACL, if there is one, unless no reason is given. */
3386
eea0defe 3387if (acl_smtp_notquit && reason)
8f128379
PH
3388 {
3389 smtp_notquit_reason = reason;
eea0defe
JB
3390 if ((rc = acl_check(ACL_WHERE_NOTQUIT, NULL, acl_smtp_notquit, &user_msg,
3391 &log_msg)) == ERROR)
8f128379
PH
3392 log_write(0, LOG_MAIN|LOG_PANIC, "ACL for not-QUIT returned ERROR: %s",
3393 log_msg);
3394 }
3395
3396/* Write an SMTP response if we are expected to give one. As the default
3397responses are all internal, they should always fit in the buffer, but code a
3398warning, just in case. Note that string_vformat() still leaves a complete
3399string, even if it is incomplete. */
3400
eea0defe 3401if (code && defaultrespond)
8f128379 3402 {
eea0defe
JB
3403 if (user_msg)
3404 smtp_respond(code, 3, TRUE, user_msg);
3405 else
8f128379
PH
3406 {
3407 uschar buffer[128];
3408 va_list ap;
3409 va_start(ap, defaultrespond);
3410 if (!string_vformat(buffer, sizeof(buffer), CS defaultrespond, ap))
3411 log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_notquit_exit()");
925ac8e4 3412 smtp_printf("%s %s\r\n", FALSE, code, buffer);
8f128379
PH
3413 va_end(ap);
3414 }
8f128379
PH
3415 mac_smtp_fflush();
3416 }
3417}
3418
3419
3420
3421
3422/*************************************************
d7b47fd0
PH
3423* Verify HELO argument *
3424*************************************************/
3425
3426/* This function is called if helo_verify_hosts or helo_try_verify_hosts is
3427matched. It is also called from ACL processing if verify = helo is used and
3428verification was not previously tried (i.e. helo_try_verify_hosts was not
3429matched). The result of its processing is to set helo_verified and
3430helo_verify_failed. These variables should both be FALSE for this function to
3431be called.
3432
3433Note that EHLO/HELO is legitimately allowed to quote an address literal. Allow
3434for IPv6 ::ffff: literals.
3435
3436Argument: none
3437Returns: TRUE if testing was completed;
3438 FALSE on a temporary failure
3439*/
3440
3441BOOL
3442smtp_verify_helo(void)
3443{
3444BOOL yield = TRUE;
3445
3446HDEBUG(D_receive) debug_printf("verifying EHLO/HELO argument \"%s\"\n",
3447 sender_helo_name);
3448
3449if (sender_helo_name == NULL)
3450 {
3451 HDEBUG(D_receive) debug_printf("no EHLO/HELO command was issued\n");
3452 }
3453
d1d5595c
PH
3454/* Deal with the case of -bs without an IP address */
3455
3456else if (sender_host_address == NULL)
3457 {
3458 HDEBUG(D_receive) debug_printf("no client IP address: assume success\n");
3459 helo_verified = TRUE;
3460 }
3461
3462/* Deal with the more common case when there is a sending IP address */
3463
d7b47fd0
PH
3464else if (sender_helo_name[0] == '[')
3465 {
3466 helo_verified = Ustrncmp(sender_helo_name+1, sender_host_address,
3467 Ustrlen(sender_host_address)) == 0;
3468
3469 #if HAVE_IPV6
3470 if (!helo_verified)
3471 {
3472 if (strncmpic(sender_host_address, US"::ffff:", 7) == 0)
3473 helo_verified = Ustrncmp(sender_helo_name + 1,
3474 sender_host_address + 7, Ustrlen(sender_host_address) - 7) == 0;
3475 }
3476 #endif
3477
3478 HDEBUG(D_receive)
3479 { if (helo_verified) debug_printf("matched host address\n"); }
3480 }
3481
3482/* Do a reverse lookup if one hasn't already given a positive or negative
3483response. If that fails, or the name doesn't match, try checking with a forward
3484lookup. */
3485
3486else
3487 {
3488 if (sender_host_name == NULL && !host_lookup_failed)
3489 yield = host_name_lookup() != DEFER;
3490
3491 /* If a host name is known, check it and all its aliases. */
3492
1705dd20
JH
3493 if (sender_host_name)
3494 if ((helo_verified = strcmpic(sender_host_name, sender_helo_name) == 0))
d7b47fd0 3495 {
1705dd20 3496 sender_helo_dnssec = sender_host_dnssec;
d7b47fd0
PH
3497 HDEBUG(D_receive) debug_printf("matched host name\n");
3498 }
3499 else
3500 {
3501 uschar **aliases = sender_host_aliases;
1705dd20
JH
3502 while (*aliases)
3503 if ((helo_verified = strcmpic(*aliases++, sender_helo_name) == 0))
3504 {
3505 sender_helo_dnssec = sender_host_dnssec;
3506 break;
3507 }
3508
3509 HDEBUG(D_receive) if (helo_verified)
d7b47fd0 3510 debug_printf("matched alias %s\n", *(--aliases));
d7b47fd0 3511 }
d7b47fd0
PH
3512
3513 /* Final attempt: try a forward lookup of the helo name */
3514
3515 if (!helo_verified)
3516 {
3517 int rc;
3518 host_item h;
1705dd20
JH
3519 dnssec_domains d;
3520 host_item *hh;
3521
d7b47fd0
PH
3522 h.name = sender_helo_name;
3523 h.address = NULL;
3524 h.mx = MX_NONE;
3525 h.next = NULL;
1705dd20
JH
3526 d.request = US"*";
3527 d.require = US"";
3528
d7b47fd0
PH
3529 HDEBUG(D_receive) debug_printf("getting IP address for %s\n",
3530 sender_helo_name);
66387a73 3531 rc = host_find_bydns(&h, NULL, HOST_FIND_BY_A | HOST_FIND_BY_AAAA,
1705dd20 3532 NULL, NULL, NULL, &d, NULL, NULL);
d7b47fd0 3533 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
1705dd20 3534 for (hh = &h; hh; hh = hh->next)
d7b47fd0
PH
3535 if (Ustrcmp(hh->address, sender_host_address) == 0)
3536 {
3537 helo_verified = TRUE;
1705dd20 3538 if (h.dnssec == DS_YES) sender_helo_dnssec = TRUE;
d7b47fd0 3539 HDEBUG(D_receive)
1705dd20
JH
3540 {
3541 debug_printf("IP address for %s matches calling address\n"
3542 "Forward DNS security status: %sverified\n",
3543 sender_helo_name, sender_helo_dnssec ? "" : "un");
3544 }
d7b47fd0
PH
3545 break;
3546 }
d7b47fd0
PH
3547 }
3548 }
3549
d1d5595c 3550if (!helo_verified) helo_verify_failed = TRUE; /* We've tried ... */
d7b47fd0
PH
3551return yield;
3552}
3553
3554
3555
3556
3557/*************************************************
4e88a19f
PH
3558* Send user response message *
3559*************************************************/
3560
3561/* This function is passed a default response code and a user message. It calls
3562smtp_message_code() to check and possibly modify the response code, and then
3563calls smtp_respond() to transmit the response. I put this into a function
3564just to avoid a lot of repetition.
3565
3566Arguments:
3567 code the response code
3568 user_msg the user message