FreeBSD: better support for TFO
[exim.git] / src / src / smtp_in.c
CommitLineData
059ec3d9
PH
1/*************************************************
2* Exim - an Internet mail transport agent *
3*************************************************/
4
f9ba5e22 5/* Copyright (c) University of Cambridge 1995 - 2018 */
059ec3d9
PH
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>
059ec3d9
PH
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;
059ec3d9
PH
34#endif
35
36
8d67ada3
PH
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
94431adb
HSHR
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
e2ca7082
PP
44we need room to handle large base64-encoded AUTHs for GSSAPI.
45*/
46
bd8fbe36 47#define SMTP_CMD_BUFFER_SIZE 16384
059ec3d9
PH
48
49/* Size of buffer for reading SMTP incoming packets */
50
bd8fbe36 51#define IN_BUFFER_SIZE 8192
059ec3d9
PH
52
53/* Structure for SMTP command list */
54
55typedef struct {
1ba28e2b 56 const char *name;
059ec3d9
PH
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 */
059ec3d9
PH
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
f4630439
JH
85 /* This is a dummy to identify the non-sync commands when not pipelining */
86
87 NON_SYNC_CMD_NON_PIPELINING,
88
6d5c916c
JH
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
f4630439
JH
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. */
6d5c916c
JH
99
100 BDAT_CMD,
101
059ec3d9
PH
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
a3c86431
TL
113 PROXY_FAIL_IGNORE_CMD,
114#endif
115
059ec3d9
PH
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
b4ed4da0
PH
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
059ec3d9
PH
129
130/*************************************************
131* Local static variables *
132*************************************************/
133
88752192
JH
134static struct {
135 BOOL auth_advertised :1;
01603eec 136#ifndef DISABLE_TLS
88752192 137 BOOL tls_advertised :1;
059ec3d9 138#endif
88752192
JH
139 BOOL dsn_advertised :1;
140 BOOL esmtp :1;
141 BOOL helo_required :1;
142 BOOL helo_verify :1;
143 BOOL helo_seen :1;
144 BOOL helo_accept_junk :1;
81344b40 145#ifndef DISABLE_PIPE_CONNECT
ee8b8090
JH
146 BOOL pipe_connect_acceptable :1;
147#endif
88752192
JH
148 BOOL rcpt_smtp_response_same :1;
149 BOOL rcpt_in_progress :1;
150 BOOL smtp_exit_function_called :1;
8c5d388a 151#ifdef SUPPORT_I18N
88752192 152 BOOL smtputf8_advertised :1;
d1a13eea 153#endif
88752192
JH
154} fl = {
155 .helo_required = FALSE,
156 .helo_verify = FALSE,
157 .smtp_exit_function_called = FALSE,
158};
159
160static auth_instance *authenticated_by;
161static int count_nonmail;
162static int nonmail_command_count;
059ec3d9
PH
163static int synprot_error_count;
164static int unknown_command_count;
165static int sync_cmd_limit;
166static int smtp_write_error = 0;
167
2679d413 168static uschar *rcpt_smtp_response;
ca86f471
PH
169static uschar *smtp_data_buffer;
170static uschar *smtp_cmd_data;
171
059ec3d9
PH
172/* We need to know the position of RSET, HELO, EHLO, AUTH, and STARTTLS. Their
173final fields of all except AUTH are forced TRUE at the start of a new message
174setup, to allow one of each between messages that is not counted as a nonmail
175command. (In fact, only one of HELO/EHLO is not counted.) Also, we have to
176allow a new EHLO after starting up TLS.
177
178AUTH is "falsely" labelled as a mail command initially, so that it doesn't get
179counted. However, the flag is changed when AUTH is received, so that multiple
180failing AUTHs will eventually hit the limit. After a successful AUTH, another
181AUTH is already forbidden. After a TLS session is started, AUTH's flag is again
182forced TRUE, to allow for the re-authentication that can happen at that point.
183
184QUIT is also "falsely" labelled as a mail command so that it doesn't up the
2f460950
JH
185count of non-mail commands and possibly provoke an error.
186
187tls_auth is a pseudo-command, never expected in input. It is activated
188on TLS startup and looks for a tls authenticator. */
059ec3d9
PH
189
190static smtp_cmd_list cmd_list[] = {
d1a13eea
JH
191 /* name len cmd has_arg is_mail_cmd */
192
059ec3d9
PH
193 { "rset", sizeof("rset")-1, RSET_CMD, FALSE, FALSE }, /* First */
194 { "helo", sizeof("helo")-1, HELO_CMD, TRUE, FALSE },
195 { "ehlo", sizeof("ehlo")-1, EHLO_CMD, TRUE, FALSE },
196 { "auth", sizeof("auth")-1, AUTH_CMD, TRUE, TRUE },
01603eec 197#ifndef DISABLE_TLS
059ec3d9 198 { "starttls", sizeof("starttls")-1, STARTTLS_CMD, FALSE, FALSE },
69d8eed7 199 { "tls_auth", 0, TLS_AUTH_CMD, FALSE, FALSE },
e0574cb5 200#endif
059ec3d9
PH
201
202/* If you change anything above here, also fix the definitions below. */
203
204 { "mail from:", sizeof("mail from:")-1, MAIL_CMD, TRUE, TRUE },
205 { "rcpt to:", sizeof("rcpt to:")-1, RCPT_CMD, TRUE, TRUE },
206 { "data", sizeof("data")-1, DATA_CMD, FALSE, TRUE },
18481de3 207 { "bdat", sizeof("bdat")-1, BDAT_CMD, TRUE, TRUE },
059ec3d9
PH
208 { "quit", sizeof("quit")-1, QUIT_CMD, FALSE, TRUE },
209 { "noop", sizeof("noop")-1, NOOP_CMD, TRUE, FALSE },
210 { "etrn", sizeof("etrn")-1, ETRN_CMD, TRUE, FALSE },
211 { "vrfy", sizeof("vrfy")-1, VRFY_CMD, TRUE, FALSE },
212 { "expn", sizeof("expn")-1, EXPN_CMD, TRUE, FALSE },
213 { "help", sizeof("help")-1, HELP_CMD, TRUE, FALSE }
214};
215
216static smtp_cmd_list *cmd_list_end =
217 cmd_list + sizeof(cmd_list)/sizeof(smtp_cmd_list);
218
219#define CMD_LIST_RSET 0
220#define CMD_LIST_HELO 1
221#define CMD_LIST_EHLO 2
222#define CMD_LIST_AUTH 3
223#define CMD_LIST_STARTTLS 4
b3ef41c9 224#define CMD_LIST_TLS_AUTH 5
059ec3d9 225
b4ed4da0
PH
226/* This list of names is used for performing the smtp_no_mail logging action.
227It must be kept in step with the SCH_xxx enumerations. */
228
229static uschar *smtp_names[] =
230 {
18481de3
JH
231 US"NONE", US"AUTH", US"DATA", US"BDAT", US"EHLO", US"ETRN", US"EXPN",
232 US"HELO", US"HELP", US"MAIL", US"NOOP", US"QUIT", US"RCPT", US"RSET",
233 US"STARTTLS", US"VRFY" };
b4ed4da0 234
e524074d 235static uschar *protocols_local[] = {
981756db
PH
236 US"local-smtp", /* HELO */
237 US"local-smtps", /* The rare case EHLO->STARTTLS->HELO */
238 US"local-esmtp", /* EHLO */
239 US"local-esmtps", /* EHLO->STARTTLS->EHLO */
240 US"local-esmtpa", /* EHLO->AUTH */
241 US"local-esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */
059ec3d9 242 };
e524074d
JH
243static uschar *protocols[] = {
244 US"smtp", /* HELO */
245 US"smtps", /* The rare case EHLO->STARTTLS->HELO */
246 US"esmtp", /* EHLO */
247 US"esmtps", /* EHLO->STARTTLS->EHLO */
248 US"esmtpa", /* EHLO->AUTH */
249 US"esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */
250 };
059ec3d9
PH
251
252#define pnormal 0
981756db
PH
253#define pextend 2
254#define pcrpted 1 /* added to pextend or pnormal */
255#define pauthed 2 /* added to pextend */
059ec3d9 256
d27f98fe
TL
257/* Sanity check and validate optional args to MAIL FROM: envelope */
258enum {
2ef7ed08 259 ENV_MAIL_OPT_NULL,
d27f98fe 260 ENV_MAIL_OPT_SIZE, ENV_MAIL_OPT_BODY, ENV_MAIL_OPT_AUTH,
8ccd00b1 261#ifndef DISABLE_PRDR
fd98a5c6
JH
262 ENV_MAIL_OPT_PRDR,
263#endif
6c1c3d1d 264 ENV_MAIL_OPT_RET, ENV_MAIL_OPT_ENVID,
8c5d388a 265#ifdef SUPPORT_I18N
d1a13eea
JH
266 ENV_MAIL_OPT_UTF8,
267#endif
d27f98fe
TL
268 };
269typedef struct {
270 uschar * name; /* option requested during MAIL cmd */
271 int value; /* enum type */
272 BOOL need_value; /* TRUE requires value (name=value pair format)
273 FALSE is a singleton */
274 } env_mail_type_t;
275static env_mail_type_t env_mail_type_list[] = {
276 { US"SIZE", ENV_MAIL_OPT_SIZE, TRUE },
277 { US"BODY", ENV_MAIL_OPT_BODY, TRUE },
278 { US"AUTH", ENV_MAIL_OPT_AUTH, TRUE },
8ccd00b1 279#ifndef DISABLE_PRDR
fd98a5c6
JH
280 { US"PRDR", ENV_MAIL_OPT_PRDR, FALSE },
281#endif
6c1c3d1d
WB
282 { US"RET", ENV_MAIL_OPT_RET, TRUE },
283 { US"ENVID", ENV_MAIL_OPT_ENVID, TRUE },
8c5d388a 284#ifdef SUPPORT_I18N
d1a13eea
JH
285 { US"SMTPUTF8",ENV_MAIL_OPT_UTF8, FALSE }, /* rfc6531 */
286#endif
2ef7ed08
HSHR
287 /* keep this the last entry */
288 { US"NULL", ENV_MAIL_OPT_NULL, FALSE },
d27f98fe
TL
289 };
290
059ec3d9
PH
291/* When reading SMTP from a remote host, we have to use our own versions of the
292C input-reading functions, in order to be able to flush the SMTP output only
293when about to read more data from the socket. This is the only way to get
294optimal performance when the client is using pipelining. Flushing for every
295command causes a separate packet and reply packet each time; saving all the
296responses up (when pipelining) combines them into one packet and one response.
297
298For simplicity, these functions are used for *all* SMTP input, not only when
299receiving over a socket. However, after setting up a secure socket (SSL), input
300is read via the OpenSSL library, and another set of functions is used instead
301(see tls.c).
302
303These functions are set in the receive_getc etc. variables and called with the
304same interface as the C functions. However, since there can only ever be
305one incoming SMTP call, we just use a single buffer and flags. There is no need
306to implement a complicated private FILE-like structure.*/
307
308static uschar *smtp_inbuffer;
309static uschar *smtp_inptr;
310static uschar *smtp_inend;
311static int smtp_had_eof;
312static int smtp_had_error;
313
314
7e3ce68e 315/* forward declarations */
bd8fbe36 316static int smtp_read_command(BOOL check_sync, unsigned buffer_lim);
7e3ce68e
JH
317static int synprot_error(int type, int code, uschar *data, uschar *errmess);
318static void smtp_quit_handler(uschar **, uschar **);
319static void smtp_rset_handler(void);
320
059ec3d9 321/*************************************************
f4630439
JH
322* Recheck synchronization *
323*************************************************/
324
325/* Synchronization checks can never be perfect because a packet may be on its
925ac8e4
JH
326way but not arrived when the check is done. Normally, the checks happen when
327commands are read: Exim ensures that there is no more input in the input buffer.
328In normal cases, the response to the command will be fast, and there is no
329further check.
f4630439
JH
330
331However, for some commands an ACL is run, and that can include delays. In those
332cases, it is useful to do another check on the input just before sending the
333response. This also applies at the start of a connection. This function does
334that check by means of the select() function, as long as the facility is not
335disabled or inappropriate. A failure of select() is ignored.
336
337When there is unwanted input, we read it so that it appears in the log of the
338error.
339
340Arguments: none
341Returns: TRUE if all is well; FALSE if there is input pending
342*/
343
344static BOOL
925ac8e4 345wouldblock_reading(void)
f4630439
JH
346{
347int fd, rc;
348fd_set fds;
349struct timeval tzero;
350
01603eec 351#ifndef DISABLE_TLS
74f1a423 352if (tls_in.active.sock >= 0)
e5de01f0 353 return !tls_could_read();
9067f574 354#endif
f4630439 355
40525d07
JH
356if (smtp_inptr < smtp_inend)
357 return FALSE;
358
f4630439
JH
359fd = fileno(smtp_in);
360FD_ZERO(&fds);
361FD_SET(fd, &fds);
362tzero.tv_sec = 0;
363tzero.tv_usec = 0;
364rc = select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &tzero);
365
366if (rc <= 0) return TRUE; /* Not ready to read */
bd8fbe36 367rc = smtp_getc(GETC_BUFFER_UNLIMITED);
f4630439
JH
368if (rc < 0) return TRUE; /* End of file or error */
369
370smtp_ungetc(rc);
f4630439
JH
371return FALSE;
372}
373
925ac8e4
JH
374static BOOL
375check_sync(void)
376{
8768d548 377if (!smtp_enforce_sync || !sender_host_address || f.sender_host_notsocket)
925ac8e4
JH
378 return TRUE;
379
380return wouldblock_reading();
381}
382
383
384/* If there's input waiting (and we're doing pipelineing) then we can pipeline
385a reponse with the one following. */
386
387static BOOL
388pipeline_response(void)
389{
390if ( !smtp_enforce_sync || !sender_host_address
8768d548 391 || f.sender_host_notsocket || !f.smtp_in_pipelining_advertised)
925ac8e4
JH
392 return FALSE;
393
3fc73bdc 394if (wouldblock_reading()) return FALSE;
8768d548 395f.smtp_in_pipelining_used = TRUE;
3fc73bdc 396return TRUE;
925ac8e4
JH
397}
398
f4630439 399
81344b40 400#ifndef DISABLE_PIPE_CONNECT
ee8b8090
JH
401static BOOL
402pipeline_connect_sends(void)
403{
404if (!sender_host_address || f.sender_host_notsocket || !fl.pipe_connect_acceptable)
405 return FALSE;
406
407if (wouldblock_reading()) return FALSE;
408f.smtp_in_early_pipe_used = TRUE;
409return TRUE;
410}
411#endif
f4630439
JH
412
413/*************************************************
414* Log incomplete transactions *
415*************************************************/
416
417/* This function is called after a transaction has been aborted by RSET, QUIT,
418connection drops or other errors. It logs the envelope information received
419so far in order to preserve address verification attempts.
420
421Argument: string to indicate what aborted the transaction
422Returns: nothing
423*/
424
425static void
426incomplete_transaction_log(uschar *what)
427{
d7978c0f
JH
428if (!sender_address /* No transaction in progress */
429 || !LOGGING(smtp_incomplete_transaction))
f4630439
JH
430 return;
431
432/* Build list of recipients for logging */
433
434if (recipients_count > 0)
435 {
f3ebb786 436 raw_recipients = store_get(recipients_count * sizeof(uschar *), FALSE);
d7978c0f 437 for (int i = 0; i < recipients_count; i++)
f4630439
JH
438 raw_recipients[i] = recipients_list[i].address;
439 raw_recipients_count = recipients_count;
440 }
441
442log_write(L_smtp_incomplete_transaction, LOG_MAIN|LOG_SENDER|LOG_RECIPIENTS,
443 "%s incomplete transaction (%s)", host_and_ident(TRUE), what);
444}
445
446
447
448
9723f966
JH
449void
450smtp_command_timeout_exit(void)
451{
452log_write(L_lost_incoming_connection,
453 LOG_MAIN, "SMTP command timeout on%s connection from %s",
74f1a423 454 tls_in.active.sock >= 0 ? " TLS" : "", host_and_ident(FALSE));
9723f966
JH
455if (smtp_batched_input)
456 moan_smtp_batch(NULL, "421 SMTP command timeout"); /* Does not return */
457smtp_notquit_exit(US"command-timeout", US"421",
458 US"%s: SMTP command timeout - closing connection",
459 smtp_active_hostname);
460exim_exit(EXIT_FAILURE, US"receiving");
461}
462
463void
464smtp_command_sigterm_exit(void)
465{
466log_write(0, LOG_MAIN, "%s closed after SIGTERM", smtp_get_connection_info());
467if (smtp_batched_input)
468 moan_smtp_batch(NULL, "421 SIGTERM received"); /* Does not return */
469smtp_notquit_exit(US"signal-exit", US"421",
470 US"%s: Service not available - closing connection", smtp_active_hostname);
471exim_exit(EXIT_FAILURE, US"receiving");
472}
473
474void
475smtp_data_timeout_exit(void)
476{
477log_write(L_lost_incoming_connection,
478 LOG_MAIN, "SMTP data timeout (message abandoned) on connection from %s F=<%s>",
479 sender_fullhost ? sender_fullhost : US"local process", sender_address);
480receive_bomb_out(US"data-timeout", US"SMTP incoming data timeout");
481/* Does not return */
482}
483
484void
485smtp_data_sigint_exit(void)
486{
487log_write(0, LOG_MAIN, "%s closed after %s",
488 smtp_get_connection_info(), had_data_sigint == SIGTERM ? "SIGTERM":"SIGINT");
489receive_bomb_out(US"signal-exit",
490 US"Service not available - SIGTERM or SIGINT received");
491/* Does not return */
492}
493
494
495
0d81dabc
JH
496/* Refill the buffer, and notify DKIM verification code.
497Return false for error or EOF.
498*/
499
500static BOOL
501smtp_refill(unsigned lim)
502{
503int rc, save_errno;
504if (!smtp_out) return FALSE;
505fflush(smtp_out);
c2a1bba0 506if (smtp_receive_timeout > 0) ALARM(smtp_receive_timeout);
0d81dabc 507
ecce6d9a
JH
508/* Limit amount read, so non-message data is not fed to DKIM.
509Take care to not touch the safety NUL at the end of the buffer. */
0d81dabc 510
ecce6d9a 511rc = read(fileno(smtp_in), smtp_inbuffer, MIN(IN_BUFFER_SIZE-1, lim));
0d81dabc 512save_errno = errno;
c2a1bba0 513if (smtp_receive_timeout > 0) ALARM_CLR(0);
0d81dabc
JH
514if (rc <= 0)
515 {
516 /* Must put the error text in fixed store, because this might be during
517 header reading, where it releases unused store above the header. */
518 if (rc < 0)
519 {
9723f966
JH
520 if (had_command_timeout) /* set by signal handler */
521 smtp_command_timeout_exit(); /* does not return */
522 if (had_command_sigterm)
523 smtp_command_sigterm_exit();
524 if (had_data_timeout)
525 smtp_data_timeout_exit();
526 if (had_data_sigint)
527 smtp_data_sigint_exit();
528
0d81dabc 529 smtp_had_error = save_errno;
f3ebb786
JH
530 smtp_read_error = string_copy_perm(
531 string_sprintf(" (error: %s)", strerror(save_errno)), FALSE);
0d81dabc 532 }
9723f966
JH
533 else
534 smtp_had_eof = 1;
0d81dabc
JH
535 return FALSE;
536 }
537#ifndef DISABLE_DKIM
538dkim_exim_verify_feed(smtp_inbuffer, rc);
539#endif
540smtp_inend = smtp_inbuffer + rc;
541smtp_inptr = smtp_inbuffer;
542return TRUE;
543}
544
f4630439 545/*************************************************
059ec3d9
PH
546* SMTP version of getc() *
547*************************************************/
548
549/* This gets the next byte from the SMTP input buffer. If the buffer is empty,
550it flushes the output, and refills the buffer, with a timeout. The signal
551handler is set appropriately by the calling function. This function is not used
4c04137d 552after a connection has negotiated itself into an TLS/SSL state.
059ec3d9 553
bd8fbe36 554Arguments: lim Maximum amount to read/buffer
059ec3d9
PH
555Returns: the next character or EOF
556*/
557
558int
bd8fbe36 559smtp_getc(unsigned lim)
059ec3d9
PH
560{
561if (smtp_inptr >= smtp_inend)
0d81dabc 562 if (!smtp_refill(lim))
059ec3d9 563 return EOF;
059ec3d9
PH
564return *smtp_inptr++;
565}
566
0d81dabc
JH
567uschar *
568smtp_getbuf(unsigned * len)
569{
570unsigned size;
571uschar * buf;
572
573if (smtp_inptr >= smtp_inend)
574 if (!smtp_refill(*len))
575 { *len = 0; return NULL; }
576
577if ((size = smtp_inend - smtp_inptr) > *len) size = *len;
578buf = smtp_inptr;
579smtp_inptr += size;
580*len = size;
581return buf;
582}
583
584e96c6
JH
584void
585smtp_get_cache(void)
586{
9960d1e5 587#ifndef DISABLE_DKIM
584e96c6
JH
588int n = smtp_inend - smtp_inptr;
589if (n > 0)
590 dkim_exim_verify_feed(smtp_inptr, n);
584e96c6 591#endif
9960d1e5 592}
059ec3d9
PH
593
594
7e3ce68e
JH
595/* Get a byte from the smtp input, in CHUNKING mode. Handle ack of the
596previous BDAT chunk and getting new ones when we run out. Uses the
597underlying smtp_getc or tls_getc both for that and for getting the
598(buffered) data byte. EOD signals (an expected) no further data.
599ERR signals a protocol error, and EOF a closed input stream.
600
601Called from read_bdat_smtp() in receive.c for the message body, but also
602by the headers read loop in receive_msg(); manipulates chunking_state
603to handle the BDAT command/response.
604Placed here due to the correlation with the above smtp_getc(), which it wraps,
605and also by the need to do smtp command/response handling.
606
bd8fbe36 607Arguments: lim (ignored)
7e3ce68e
JH
608Returns: the next character or ERR, EOD or EOF
609*/
610
611int
bd8fbe36 612bdat_getc(unsigned lim)
7e3ce68e
JH
613{
614uschar * user_msg = NULL;
615uschar * log_msg;
616
617for(;;)
618 {
79de4f37 619#ifndef DISABLE_DKIM
64b67b65 620 unsigned dkim_save;
79de4f37
JH
621#endif
622
bd8fbe36
JH
623 if (chunking_data_left > 0)
624 return lwr_receive_getc(chunking_data_left--);
7e3ce68e
JH
625
626 receive_getc = lwr_receive_getc;
0d81dabc 627 receive_getbuf = lwr_receive_getbuf;
7e3ce68e 628 receive_ungetc = lwr_receive_ungetc;
bd8fbe36 629#ifndef DISABLE_DKIM
79de4f37 630 dkim_save = dkim_collect_input;
64b67b65 631 dkim_collect_input = 0;
bd8fbe36 632#endif
7e3ce68e 633
f4630439
JH
634 /* Unless PIPELINING was offered, there should be no next command
635 until after we ack that chunk */
636
8768d548 637 if (!f.smtp_in_pipelining_advertised && !check_sync())
f4630439 638 {
40525d07
JH
639 unsigned n = smtp_inend - smtp_inptr;
640 if (n > 32) n = 32;
641
f4630439
JH
642 incomplete_transaction_log(US"sync failure");
643 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol synchronization error "
644 "(next input sent too soon: pipelining was not advertised): "
9e0ed81f 645 "rejected \"%s\" %s next input=\"%s\"%s",
f4630439 646 smtp_cmd_buffer, host_and_ident(TRUE),
9e0ed81f
JH
647 string_printing(string_copyn(smtp_inptr, n)),
648 smtp_inend - smtp_inptr > n ? "..." : "");
649 (void) synprot_error(L_smtp_protocol_error, 554, NULL,
650 US"SMTP synchronization error");
f4630439
JH
651 goto repeat_until_rset;
652 }
653
7e3ce68e
JH
654 /* If not the last, ack the received chunk. The last response is delayed
655 until after the data ACL decides on it */
7e3ce68e
JH
656
657 if (chunking_state == CHUNKING_LAST)
584e96c6
JH
658 {
659#ifndef DISABLE_DKIM
e983e85a 660 dkim_exim_verify_feed(NULL, 0); /* notify EOD */
584e96c6 661#endif
7e3ce68e 662 return EOD;
584e96c6 663 }
7e3ce68e 664
925ac8e4 665 smtp_printf("250 %u byte chunk received\r\n", FALSE, chunking_datasize);
bd8fbe36
JH
666 chunking_state = CHUNKING_OFFERED;
667 DEBUG(D_receive) debug_printf("chunking state %d\n", (int)chunking_state);
7e3ce68e
JH
668
669 /* Expect another BDAT cmd from input. RFC 3030 says nothing about
670 QUIT, RSET or NOOP but handling them seems obvious */
671
672next_cmd:
bd8fbe36 673 switch(smtp_read_command(TRUE, 1))
7e3ce68e
JH
674 {
675 default:
676 (void) synprot_error(L_smtp_protocol_error, 503, NULL,
677 US"only BDAT permissible after non-LAST BDAT");
678
679 repeat_until_rset:
bd8fbe36 680 switch(smtp_read_command(TRUE, 1))
7e3ce68e
JH
681 {
682 case QUIT_CMD: smtp_quit_handler(&user_msg, &log_msg); /*FALLTHROUGH */
683 case EOF_CMD: return EOF;
684 case RSET_CMD: smtp_rset_handler(); return ERR;
685 default: if (synprot_error(L_smtp_protocol_error, 503, NULL,
686 US"only RSET accepted now") > 0)
687 return EOF;
688 goto repeat_until_rset;
689 }
690
691 case QUIT_CMD:
692 smtp_quit_handler(&user_msg, &log_msg);
693 /*FALLTHROUGH*/
694 case EOF_CMD:
695 return EOF;
696
697 case RSET_CMD:
698 smtp_rset_handler();
699 return ERR;
700
701 case NOOP_CMD:
702 HAD(SCH_NOOP);
925ac8e4 703 smtp_printf("250 OK\r\n", FALSE);
7e3ce68e
JH
704 goto next_cmd;
705
706 case BDAT_CMD:
707 {
708 int n;
709
710 if (sscanf(CS smtp_cmd_data, "%u %n", &chunking_datasize, &n) < 1)
711 {
712 (void) synprot_error(L_smtp_protocol_error, 501, NULL,
713 US"missing size for BDAT command");
714 return ERR;
715 }
716 chunking_state = strcmpic(smtp_cmd_data+n, US"LAST") == 0
717 ? CHUNKING_LAST : CHUNKING_ACTIVE;
718 chunking_data_left = chunking_datasize;
bd8fbe36
JH
719 DEBUG(D_receive) debug_printf("chunking state %d, %d bytes\n",
720 (int)chunking_state, chunking_data_left);
7e3ce68e
JH
721
722 if (chunking_datasize == 0)
723 if (chunking_state == CHUNKING_LAST)
724 return EOD;
725 else
726 {
727 (void) synprot_error(L_smtp_protocol_error, 504, NULL,
728 US"zero size for BDAT command");
729 goto repeat_until_rset;
730 }
731
732 receive_getc = bdat_getc;
8b77d27a 733 receive_getbuf = bdat_getbuf; /* r~getbuf is never actually used */
7e3ce68e 734 receive_ungetc = bdat_ungetc;
bd8fbe36 735#ifndef DISABLE_DKIM
79de4f37 736 dkim_collect_input = dkim_save;
bd8fbe36 737#endif
7e3ce68e
JH
738 break; /* to top of main loop */
739 }
740 }
741 }
742}
743
0d81dabc
JH
744uschar *
745bdat_getbuf(unsigned * len)
746{
747uschar * buf;
748
749if (chunking_data_left <= 0)
750 { *len = 0; return NULL; }
751
752if (*len > chunking_data_left) *len = chunking_data_left;
753buf = lwr_receive_getbuf(len); /* Either smtp_getbuf or tls_getbuf */
754chunking_data_left -= *len;
755return buf;
756}
757
1ebe15c3 758void
45bd315d
JH
759bdat_flush_data(void)
760{
e99a3a6c 761while (chunking_data_left)
db57e575 762 {
e99a3a6c 763 unsigned n = chunking_data_left;
8b77d27a 764 if (!bdat_getbuf(&n)) break;
db57e575 765 }
45bd315d
JH
766
767receive_getc = lwr_receive_getc;
0d81dabc 768receive_getbuf = lwr_receive_getbuf;
45bd315d
JH
769receive_ungetc = lwr_receive_ungetc;
770
771if (chunking_state != CHUNKING_LAST)
bd8fbe36 772 {
45bd315d 773 chunking_state = CHUNKING_OFFERED;
bd8fbe36
JH
774 DEBUG(D_receive) debug_printf("chunking state %d\n", (int)chunking_state);
775 }
45bd315d
JH
776}
777
7e3ce68e
JH
778
779
780
059ec3d9
PH
781/*************************************************
782* SMTP version of ungetc() *
783*************************************************/
784
785/* Puts a character back in the input buffer. Only ever
786called once.
787
788Arguments:
789 ch the character
790
791Returns: the character
792*/
793
794int
795smtp_ungetc(int ch)
796{
7e3ce68e 797*--smtp_inptr = ch;
059ec3d9
PH
798return ch;
799}
800
801
7e3ce68e
JH
802int
803bdat_ungetc(int ch)
804{
805chunking_data_left++;
806return lwr_receive_ungetc(ch);
807}
808
059ec3d9
PH
809
810
811/*************************************************
812* SMTP version of feof() *
813*************************************************/
814
815/* Tests for a previous EOF
816
817Arguments: none
818Returns: non-zero if the eof flag is set
819*/
820
821int
822smtp_feof(void)
823{
824return smtp_had_eof;
825}
826
827
828
829
830/*************************************************
831* SMTP version of ferror() *
832*************************************************/
833
834/* Tests for a previous read error, and returns with errno
835restored to what it was when the error was detected.
836
837Arguments: none
838Returns: non-zero if the error flag is set
839*/
840
841int
842smtp_ferror(void)
843{
844errno = smtp_had_error;
845return smtp_had_error;
846}
847
848
849
58eb016e
PH
850/*************************************************
851* Test for characters in the SMTP buffer *
852*************************************************/
853
854/* Used at the end of a message
855
856Arguments: none
857Returns: TRUE/FALSE
858*/
859
860BOOL
861smtp_buffered(void)
862{
863return smtp_inptr < smtp_inend;
864}
865
866
059ec3d9
PH
867
868/*************************************************
869* Write formatted string to SMTP channel *
870*************************************************/
871
872/* This is a separate function so that we don't have to repeat everything for
873TLS support or debugging. It is global so that the daemon and the
874authentication functions can use it. It does not return any error indication,
875because major problems such as dropped connections won't show up till an output
876flush for non-TLS connections. The smtp_fflush() function is available for
877checking that: for convenience, TLS output errors are remembered here so that
878they are also picked up later by smtp_fflush().
879
880Arguments:
881 format format string
925ac8e4 882 more further data expected
059ec3d9
PH
883 ... optional arguments
884
885Returns: nothing
886*/
887
888void
925ac8e4 889smtp_printf(const char *format, BOOL more, ...)
059ec3d9
PH
890{
891va_list ap;
892
925ac8e4
JH
893va_start(ap, more);
894smtp_vprintf(format, more, ap);
ce552449
NM
895va_end(ap);
896}
897
898/* This is split off so that verify.c:respond_printf() can, in effect, call
899smtp_printf(), bearing in mind that in C a vararg function can't directly
fb08281f 900call another vararg function, only a function which accepts a va_list. */
f3ebb786 901/*XXX consider passing caller-info in, for string_vformat-onward */
ce552449
NM
902
903void
925ac8e4 904smtp_vprintf(const char *format, BOOL more, va_list ap)
ce552449 905{
d12746bc 906gstring gs = { .size = big_buffer_size, .ptr = 0, .s = big_buffer };
fb08281f
DW
907BOOL yield;
908
f3ebb786
JH
909/* Use taint-unchecked routines for writing into big_buffer, trusting
910that we'll never expand it. */
911
912yield = !! string_vformat(&gs, SVFMT_TAINT_NOCHK, format, ap);
d12746bc 913string_from_gstring(&gs);
ce552449 914
059ec3d9
PH
915DEBUG(D_receive)
916 {
fb08281f 917 uschar *msg_copy, *cr, *end;
d12746bc
JH
918 msg_copy = string_copy(gs.s);
919 end = msg_copy + gs.ptr;
fb08281f 920 while ((cr = Ustrchr(msg_copy, '\r')) != NULL) /* lose CRs */
d12746bc 921 memmove(cr, cr + 1, (end--) - cr);
fb08281f 922 debug_printf("SMTP>> %s", msg_copy);
059ec3d9
PH
923 }
924
fb08281f 925if (!yield)
2679d413
PH
926 {
927 log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_printf()");
928 smtp_closedown(US"Unexpected error");
9bfb7e1b 929 exim_exit(EXIT_FAILURE, NULL);
2679d413 930 }
2679d413
PH
931
932/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
933have had the same. Note: this code is also present in smtp_respond(). It would
934be tidier to have it only in one place, but when it was added, it was easier to
935do it that way, so as not to have to mess with the code for the RCPT command,
936which sometimes uses smtp_printf() and sometimes smtp_respond(). */
937
88752192 938if (fl.rcpt_in_progress)
2679d413
PH
939 {
940 if (rcpt_smtp_response == NULL)
941 rcpt_smtp_response = string_copy(big_buffer);
88752192 942 else if (fl.rcpt_smtp_response_same &&
2679d413 943 Ustrcmp(rcpt_smtp_response, big_buffer) != 0)
88752192
JH
944 fl.rcpt_smtp_response_same = FALSE;
945 fl.rcpt_in_progress = FALSE;
2679d413 946 }
059ec3d9 947
2679d413 948/* Now write the string */
059ec3d9 949
30398c06 950if (
01603eec 951#ifndef DISABLE_TLS
30398c06 952 tls_in.active.sock >= 0 ? (tls_write(NULL, gs.s, gs.ptr, more) < 0) :
059ec3d9 953#endif
30398c06
JH
954 (fwrite(gs.s, gs.ptr, 1, smtp_out) == 0)
955 )
956 smtp_write_error = -1;
059ec3d9
PH
957}
958
959
960
961/*************************************************
962* Flush SMTP out and check for error *
963*************************************************/
964
965/* This function isn't currently used within Exim (it detects errors when it
966tries to read the next SMTP input), but is available for use in local_scan().
30398c06 967It flushes the output and checks for errors.
059ec3d9
PH
968
969Arguments: none
970Returns: 0 for no error; -1 after an error
971*/
972
973int
974smtp_fflush(void)
975{
74f1a423 976if (tls_in.active.sock < 0 && fflush(smtp_out) != 0) smtp_write_error = -1;
30398c06
JH
977
978if (
979#ifndef DISABLE_TLS
980 tls_in.active.sock >= 0 ? (tls_write(NULL, NULL, 0, FALSE) < 0) :
981#endif
982 (fflush(smtp_out) != 0)
983 )
984 smtp_write_error = -1;
985
059ec3d9
PH
986return smtp_write_error;
987}
988
989
990
991/*************************************************
992* SMTP command read timeout *
993*************************************************/
994
995/* Signal handler for timing out incoming SMTP commands. This attempts to
996finish off tidily.
997
998Argument: signal number (SIGALRM)
999Returns: nothing
1000*/
1001
1002static void
1003command_timeout_handler(int sig)
1004{
9723f966 1005had_command_timeout = sig;
059ec3d9
PH
1006}
1007
1008
1009
1010/*************************************************
1011* SIGTERM received *
1012*************************************************/
1013
1014/* Signal handler for handling SIGTERM. Again, try to finish tidily.
1015
1016Argument: signal number (SIGTERM)
1017Returns: nothing
1018*/
1019
1020static void
1021command_sigterm_handler(int sig)
1022{
9723f966 1023had_command_sigterm = sig;
059ec3d9
PH
1024}
1025
1026
1027
a14e5636 1028
cee5f132 1029#ifdef SUPPORT_PROXY
a3c86431 1030/*************************************************
a3bddaa8
TL
1031* Restore socket timeout to previous value *
1032*************************************************/
1033/* If the previous value was successfully retrieved, restore
1034it before returning control to the non-proxy routines
1035
1036Arguments: fd - File descriptor for input
1037 get_ok - Successfully retrieved previous values
1038 tvtmp - Time struct with previous values
1039 vslen - Length of time struct
1040Returns: none
1041*/
1042static void
f267271d 1043restore_socket_timeout(int fd, int get_ok, struct timeval * tvtmp, socklen_t vslen)
a3bddaa8
TL
1044{
1045if (get_ok == 0)
f267271d 1046 (void) setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS tvtmp, vslen);
a3bddaa8
TL
1047}
1048
1049/*************************************************
a3c86431
TL
1050* Check if host is required proxy host *
1051*************************************************/
1052/* The function determines if inbound host will be a regular smtp host
1811cb4c
JH
1053or if it is configured that it must use Proxy Protocol. A local
1054connection cannot.
a3c86431
TL
1055
1056Arguments: none
1057Returns: bool
1058*/
1059
1060static BOOL
1061check_proxy_protocol_host()
1062{
1063int rc;
a3c86431 1064
1811cb4c
JH
1065if ( sender_host_address
1066 && (rc = verify_check_this_host(CUSS &hosts_proxy, NULL, NULL,
1067 sender_host_address, NULL)) == OK)
a3c86431
TL
1068 {
1069 DEBUG(D_receive)
1070 debug_printf("Detected proxy protocol configured host\n");
1071 proxy_session = TRUE;
1072 }
1073return proxy_session;
1074}
1075
1076
1077/*************************************************
3f251b3c
PP
1078* Read data until newline or end of buffer *
1079*************************************************/
1080/* While SMTP is server-speaks-first, TLS is client-speaks-first, so we can't
1081read an entire buffer and assume there will be nothing past a proxy protocol
1082header. Our approach normally is to use stdio, but again that relies upon
1083"STARTTLS\r\n" and a server response before the client starts TLS handshake, or
1084reading _nothing_ before client TLS handshake. So we don't want to use the
1085usual buffering reads which may read enough to block TLS starting.
1086
1087So unfortunately we're down to "read one byte at a time, with a syscall each,
1088and expect a little overhead", for all proxy-opened connections which are v1,
1089just to handle the TLS-on-connect case. Since SSL functions wrap the
1090underlying fd, we can't assume that we can feed them any already-read content.
1091
1092We need to know where to read to, the max capacity, and we'll read until we
1093get a CR and one more character. Let the caller scream if it's CR+!LF.
1094
1095Return the amount read.
1096*/
1097
1098static int
da88acae 1099swallow_until_crlf(int fd, uschar *base, int already, int capacity)
3f251b3c 1100{
2c0f3ea1
JH
1101uschar *to = base + already;
1102uschar *cr;
1103int have = 0;
1104int ret;
1105int last = 0;
1106
1107/* For "PROXY UNKNOWN\r\n" we, at time of writing, expect to have read
1108up through the \r; for the _normal_ case, we haven't yet seen the \r. */
da88acae 1109
2c0f3ea1
JH
1110cr = memchr(base, '\r', already);
1111if (cr != NULL)
1112 {
1113 if ((cr - base) < already - 1)
da88acae 1114 {
2c0f3ea1
JH
1115 /* \r and presumed \n already within what we have; probably not
1116 actually proxy protocol, but abort cleanly. */
1117 return 0;
da88acae 1118 }
2c0f3ea1
JH
1119 /* \r is last character read, just need one more. */
1120 last = 1;
1121 }
1122
1123while (capacity > 0)
1124 {
1125 do { ret = recv(fd, to, 1, 0); } while (ret == -1 && errno == EINTR);
1126 if (ret == -1)
1127 return -1;
1128 have++;
1129 if (last)
1130 return have;
1131 if (*to == '\r')
1132 last = 1;
1133 capacity--;
1134 to++;
1135 }
1136
1137/* reached end without having room for a final newline, abort */
1138errno = EOVERFLOW;
1139return -1;
3f251b3c
PP
1140}
1141
1142/*************************************************
a3c86431
TL
1143* Setup host for proxy protocol *
1144*************************************************/
1145/* The function configures the connection based on a header from the
1146inbound host to use Proxy Protocol. The specification is very exact
1147so exit with an error if do not find the exact required pieces. This
1148includes an incorrect number of spaces separating args.
1149
1150Arguments: none
f267271d 1151Returns: Boolean success
a3c86431
TL
1152*/
1153
1811cb4c 1154static void
a3c86431
TL
1155setup_proxy_protocol_host()
1156{
1157union {
1158 struct {
1159 uschar line[108];
1160 } v1;
1161 struct {
1162 uschar sig[12];
36719342
TL
1163 uint8_t ver_cmd;
1164 uint8_t fam;
1165 uint16_t len;
a3c86431
TL
1166 union {
1167 struct { /* TCP/UDP over IPv4, len = 12 */
1168 uint32_t src_addr;
1169 uint32_t dst_addr;
1170 uint16_t src_port;
1171 uint16_t dst_port;
1172 } ip4;
1173 struct { /* TCP/UDP over IPv6, len = 36 */
1174 uint8_t src_addr[16];
1175 uint8_t dst_addr[16];
1176 uint16_t src_port;
1177 uint16_t dst_port;
1178 } ip6;
1179 struct { /* AF_UNIX sockets, len = 216 */
1180 uschar src_addr[108];
1181 uschar dst_addr[108];
1182 } unx;
1183 } addr;
1184 } v2;
1185} hdr;
1186
eb57651e
TL
1187/* Temp variables used in PPv2 address:port parsing */
1188uint16_t tmpport;
1189char tmpip[INET_ADDRSTRLEN];
1190struct sockaddr_in tmpaddr;
1191char tmpip6[INET6_ADDRSTRLEN];
1192struct sockaddr_in6 tmpaddr6;
1193
da88acae
PP
1194/* We can't read "all data until end" because while SMTP is
1195server-speaks-first, the TLS handshake is client-speaks-first, so for
1196TLS-on-connect ports the proxy protocol header will usually be immediately
1197followed by a TLS handshake, and with N TLS libraries, we can't reliably
1198reinject data for reading by those. So instead we first read "enough to be
1199safely read within the header, and figure out how much more to read".
1200For v1 we will later read to the end-of-line, for v2 we will read based upon
1201the stated length.
1202
1203The v2 sig is 12 octets, and another 4 gets us the length, so we know how much
1204data is needed total. For v1, where the line looks like:
1205PROXY TCPn L3src L3dest SrcPort DestPort \r\n
1206
1207However, for v1 there's also `PROXY UNKNOWN\r\n` which is only 15 octets.
1208We seem to support that. So, if we read 14 octets then we can tell if we're
1209v2 or v1. If we're v1, we can continue reading as normal.
1210
1211If we're v2, we can't slurp up the entire header. We need the length in the
121215th & 16th octets, then to read everything after that.
1213
1214So to safely handle v1 and v2, with client-sent-first supported correctly,
1215we have to do a minimum of 3 read calls, not 1. Eww.
1216*/
1217
1218#define PROXY_INITIAL_READ 14
1219#define PROXY_V2_HEADER_SIZE 16
1220#if PROXY_INITIAL_READ > PROXY_V2_HEADER_SIZE
1221# error Code bug in sizes of data to read for proxy usage
1222#endif
1223
eb57651e 1224int get_ok = 0;
f267271d
JH
1225int size, ret;
1226int fd = fileno(smtp_in);
36719342 1227const char v2sig[12] = "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A";
9e7e0f6a 1228uschar * iptype; /* To display debug info */
a3c86431 1229struct timeval tv;
a3bddaa8 1230struct timeval tvtmp;
f267271d 1231socklen_t vslen = sizeof(struct timeval);
1811cb4c 1232BOOL yield = FALSE;
a3c86431 1233
a3bddaa8 1234/* Save current socket timeout values */
f267271d 1235get_ok = getsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS &tvtmp, &vslen);
a3bddaa8 1236
a3c86431
TL
1237/* Proxy Protocol host must send header within a short time
1238(default 3 seconds) or it's considered invalid */
1239tv.tv_sec = PROXY_NEGOTIATION_TIMEOUT_SEC;
1240tv.tv_usec = PROXY_NEGOTIATION_TIMEOUT_USEC;
f267271d 1241if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS &tv, sizeof(tv)) < 0)
1811cb4c 1242 goto bad;
a3bddaa8 1243
a3c86431
TL
1244do
1245 {
eb57651e 1246 /* The inbound host was declared to be a Proxy Protocol host, so
2c0f3ea1
JH
1247 don't do a PEEK into the data, actually slurp up enough to be
1248 "safe". Can't take it all because TLS-on-connect clients follow
1249 immediately with TLS handshake. */
3f251b3c 1250 ret = recv(fd, &hdr, PROXY_INITIAL_READ, 0);
a3c86431
TL
1251 }
1252 while (ret == -1 && errno == EINTR);
1253
1254if (ret == -1)
f267271d 1255 goto proxyfail;
a3c86431 1256
da88acae
PP
1257/* For v2, handle reading the length, and then the rest. */
1258if ((ret == PROXY_INITIAL_READ) && (memcmp(&hdr.v2, v2sig, sizeof(v2sig)) == 0))
a3c86431 1259 {
da88acae
PP
1260 int retmore;
1261 uint8_t ver;
1262
1263 /* First get the length fields. */
1264 do
1265 {
1266 retmore = recv(fd, (uschar*)&hdr + ret, PROXY_V2_HEADER_SIZE - PROXY_INITIAL_READ, 0);
1267 } while (retmore == -1 && errno == EINTR);
1268 if (retmore == -1)
3f251b3c 1269 goto proxyfail;
da88acae 1270 ret += retmore;
3f251b3c
PP
1271
1272 ver = (hdr.v2.ver_cmd & 0xf0) >> 4;
36719342
TL
1273
1274 /* May 2014: haproxy combined the version and command into one byte to
2c0f3ea1
JH
1275 allow two full bytes for the length field in order to proxy SSL
1276 connections. SSL Proxy is not supported in this version of Exim, but
1277 must still separate values here. */
36719342
TL
1278
1279 if (ver != 0x02)
1280 {
1281 DEBUG(D_receive) debug_printf("Invalid Proxy Protocol version: %d\n", ver);
1282 goto proxyfail;
1283 }
da88acae 1284
36719342 1285 /* The v2 header will always be 16 bytes per the spec. */
5d036699 1286 size = 16 + ntohs(hdr.v2.len);
da88acae
PP
1287 DEBUG(D_receive) debug_printf("Detected PROXYv2 header, size %d (limit %d)\n",
1288 size, (int)sizeof(hdr));
1289
1290 /* We should now have 16 octets (PROXY_V2_HEADER_SIZE), and we know the total
1291 amount that we need. Double-check that the size is not unreasonable, then
1292 get the rest. */
1293 if (size > sizeof(hdr))
a3c86431 1294 {
da88acae 1295 DEBUG(D_receive) debug_printf("PROXYv2 header size unreasonably large; security attack?\n");
a3c86431
TL
1296 goto proxyfail;
1297 }
da88acae
PP
1298
1299 do
1300 {
1301 do
1302 {
1303 retmore = recv(fd, (uschar*)&hdr + ret, size-ret, 0);
1304 } while (retmore == -1 && errno == EINTR);
1305 if (retmore == -1)
1306 goto proxyfail;
1307 ret += retmore;
1308 DEBUG(D_receive) debug_printf("PROXYv2: have %d/%d required octets\n", ret, size);
1309 } while (ret < size);
1310
1311 } /* end scope for getting rest of data for v2 */
1312
1313/* At this point: if PROXYv2, we've read the exact size required for all data;
1314if PROXYv1 then we've read "less than required for any valid line" and should
1315read the rest". */
1316
1317if (ret >= 16 && memcmp(&hdr.v2, v2sig, 12) == 0)
1318 {
1319 uint8_t cmd = (hdr.v2.ver_cmd & 0x0f);
1320
36719342 1321 switch (cmd)
a3c86431
TL
1322 {
1323 case 0x01: /* PROXY command */
1324 switch (hdr.v2.fam)
1325 {
eb57651e
TL
1326 case 0x11: /* TCPv4 address type */
1327 iptype = US"IPv4";
1328 tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.src_addr;
5d036699
JH
1329 inet_ntop(AF_INET, &tmpaddr.sin_addr, CS &tmpip, sizeof(tmpip));
1330 if (!string_is_ip_address(US tmpip, NULL))
eb57651e
TL
1331 {
1332 DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
f267271d 1333 goto proxyfail;
eb57651e 1334 }
e6d2a989 1335 proxy_local_address = sender_host_address;
eb57651e
TL
1336 sender_host_address = string_copy(US tmpip);
1337 tmpport = ntohs(hdr.v2.addr.ip4.src_port);
e6d2a989 1338 proxy_local_port = sender_host_port;
eb57651e
TL
1339 sender_host_port = tmpport;
1340 /* Save dest ip/port */
1341 tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.dst_addr;
5d036699
JH
1342 inet_ntop(AF_INET, &tmpaddr.sin_addr, CS &tmpip, sizeof(tmpip));
1343 if (!string_is_ip_address(US tmpip, NULL))
eb57651e
TL
1344 {
1345 DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype);
f267271d 1346 goto proxyfail;
eb57651e 1347 }
7a2fa0bc 1348 proxy_external_address = string_copy(US tmpip);
eb57651e 1349 tmpport = ntohs(hdr.v2.addr.ip4.dst_port);
7a2fa0bc 1350 proxy_external_port = tmpport;
a3c86431 1351 goto done;
eb57651e
TL
1352 case 0x21: /* TCPv6 address type */
1353 iptype = US"IPv6";
1354 memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.src_addr, 16);
5d036699
JH
1355 inet_ntop(AF_INET6, &tmpaddr6.sin6_addr, CS &tmpip6, sizeof(tmpip6));
1356 if (!string_is_ip_address(US tmpip6, NULL))
eb57651e
TL
1357 {
1358 DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
f267271d 1359 goto proxyfail;
eb57651e 1360 }
e6d2a989 1361 proxy_local_address = sender_host_address;
eb57651e
TL
1362 sender_host_address = string_copy(US tmpip6);
1363 tmpport = ntohs(hdr.v2.addr.ip6.src_port);
e6d2a989 1364 proxy_local_port = sender_host_port;
eb57651e
TL
1365 sender_host_port = tmpport;
1366 /* Save dest ip/port */
1367 memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.dst_addr, 16);
5d036699
JH
1368 inet_ntop(AF_INET6, &tmpaddr6.sin6_addr, CS &tmpip6, sizeof(tmpip6));
1369 if (!string_is_ip_address(US tmpip6, NULL))
eb57651e
TL
1370 {
1371 DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype);
f267271d 1372 goto proxyfail;
eb57651e 1373 }
7a2fa0bc 1374 proxy_external_address = string_copy(US tmpip6);
eb57651e 1375 tmpport = ntohs(hdr.v2.addr.ip6.dst_port);
7a2fa0bc 1376 proxy_external_port = tmpport;
a3c86431 1377 goto done;
eb57651e
TL
1378 default:
1379 DEBUG(D_receive)
1380 debug_printf("Unsupported PROXYv2 connection type: 0x%02x\n",
1381 hdr.v2.fam);
1382 goto proxyfail;
a3c86431
TL
1383 }
1384 /* Unsupported protocol, keep local connection address */
1385 break;
1386 case 0x00: /* LOCAL command */
1387 /* Keep local connection address for LOCAL */
9e7e0f6a 1388 iptype = US"local";
a3c86431
TL
1389 break;
1390 default:
eb57651e 1391 DEBUG(D_receive)
36719342 1392 debug_printf("Unsupported PROXYv2 command: 0x%x\n", cmd);
a3c86431
TL
1393 goto proxyfail;
1394 }
1395 }
5d036699 1396else if (ret >= 8 && memcmp(hdr.v1.line, "PROXY", 5) == 0)
a3c86431 1397 {
3f251b3c
PP
1398 uschar *p;
1399 uschar *end;
a3c86431
TL
1400 uschar *sp; /* Utility variables follow */
1401 int tmp_port;
3f251b3c 1402 int r2;
a3c86431
TL
1403 char *endc;
1404
3f251b3c 1405 /* get the rest of the line */
da88acae 1406 r2 = swallow_until_crlf(fd, (uschar*)&hdr, ret, sizeof(hdr)-ret);
3f251b3c
PP
1407 if (r2 == -1)
1408 goto proxyfail;
1409 ret += r2;
1410
1411 p = string_copy(hdr.v1.line);
1412 end = memchr(p, '\r', ret - 1);
1413
da88acae 1414 if (!end || (end == (uschar*)&hdr + ret) || end[1] != '\n')
a3c86431
TL
1415 {
1416 DEBUG(D_receive) debug_printf("Partial or invalid PROXY header\n");
1417 goto proxyfail;
1418 }
1419 *end = '\0'; /* Terminate the string */
a5d4db40 1420 size = end + 2 - p; /* Skip header + CRLF */
a3c86431 1421 DEBUG(D_receive) debug_printf("Detected PROXYv1 header\n");
3f251b3c 1422 DEBUG(D_receive) debug_printf("Bytes read not within PROXY header: %d\n", ret - size);
a3c86431 1423 /* Step through the string looking for the required fields. Ensure
2c0f3ea1 1424 strict adherence to required formatting, exit for any error. */
a3c86431
TL
1425 p += 5;
1426 if (!isspace(*(p++)))
1427 {
1428 DEBUG(D_receive) debug_printf("Missing space after PROXY command\n");
1429 goto proxyfail;
1430 }
1431 if (!Ustrncmp(p, CCS"TCP4", 4))
1432 iptype = US"IPv4";
1433 else if (!Ustrncmp(p,CCS"TCP6", 4))
1434 iptype = US"IPv6";
1435 else if (!Ustrncmp(p,CCS"UNKNOWN", 7))
1436 {
1437 iptype = US"Unknown";
1438 goto done;
1439 }
1440 else
1441 {
1442 DEBUG(D_receive) debug_printf("Invalid TCP type\n");
1443 goto proxyfail;
1444 }
1445
1446 p += Ustrlen(iptype);
1447 if (!isspace(*(p++)))
1448 {
1449 DEBUG(D_receive) debug_printf("Missing space after TCP4/6 command\n");
1450 goto proxyfail;
1451 }
1452 /* Find the end of the arg */
1453 if ((sp = Ustrchr(p, ' ')) == NULL)
1454 {
1455 DEBUG(D_receive)
1456 debug_printf("Did not find proxied src %s\n", iptype);
1457 goto proxyfail;
1458 }
1459 *sp = '\0';
5d036699 1460 if(!string_is_ip_address(p, NULL))
a3c86431
TL
1461 {
1462 DEBUG(D_receive)
1463 debug_printf("Proxied src arg is not an %s address\n", iptype);
1464 goto proxyfail;
1465 }
e6d2a989 1466 proxy_local_address = sender_host_address;
a3c86431
TL
1467 sender_host_address = p;
1468 p = sp + 1;
1469 if ((sp = Ustrchr(p, ' ')) == NULL)
1470 {
1471 DEBUG(D_receive)
1472 debug_printf("Did not find proxy dest %s\n", iptype);
1473 goto proxyfail;
1474 }
1475 *sp = '\0';
5d036699 1476 if(!string_is_ip_address(p, NULL))
a3c86431
TL
1477 {
1478 DEBUG(D_receive)
1479 debug_printf("Proxy dest arg is not an %s address\n", iptype);
1480 goto proxyfail;
1481 }
7a2fa0bc 1482 proxy_external_address = p;
a3c86431
TL
1483 p = sp + 1;
1484 if ((sp = Ustrchr(p, ' ')) == NULL)
1485 {
1486 DEBUG(D_receive) debug_printf("Did not find proxied src port\n");
1487 goto proxyfail;
1488 }
1489 *sp = '\0';
5d036699 1490 tmp_port = strtol(CCS p, &endc, 10);
a3c86431
TL
1491 if (*endc || tmp_port == 0)
1492 {
1493 DEBUG(D_receive)
1494 debug_printf("Proxied src port '%s' not an integer\n", p);
1495 goto proxyfail;
1496 }
e6d2a989 1497 proxy_local_port = sender_host_port;
a3c86431
TL
1498 sender_host_port = tmp_port;
1499 p = sp + 1;
1500 if ((sp = Ustrchr(p, '\0')) == NULL)
1501 {
1502 DEBUG(D_receive) debug_printf("Did not find proxy dest port\n");
1503 goto proxyfail;
1504 }
5d036699 1505 tmp_port = strtol(CCS p, &endc, 10);
a3c86431
TL
1506 if (*endc || tmp_port == 0)
1507 {
1508 DEBUG(D_receive)
1509 debug_printf("Proxy dest port '%s' not an integer\n", p);
1510 goto proxyfail;
1511 }
7a2fa0bc 1512 proxy_external_port = tmp_port;
a3c86431 1513 /* Already checked for /r /n above. Good V1 header received. */
a3c86431
TL
1514 }
1515else
1516 {
1517 /* Wrong protocol */
eb57651e 1518 DEBUG(D_receive) debug_printf("Invalid proxy protocol version negotiation\n");
da88acae 1519 (void) swallow_until_crlf(fd, (uschar*)&hdr, ret, sizeof(hdr)-ret);
a3c86431
TL
1520 goto proxyfail;
1521 }
1522
1811cb4c
JH
1523done:
1524 DEBUG(D_receive)
1525 debug_printf("Valid %s sender from Proxy Protocol header\n", iptype);
1526 yield = proxy_session;
1527
1528/* Don't flush any potential buffer contents. Any input on proxyfail
1529should cause a synchronization failure */
1530
a3c86431 1531proxyfail:
1811cb4c 1532 restore_socket_timeout(fd, get_ok, &tvtmp, vslen);
a3c86431 1533
1811cb4c
JH
1534bad:
1535 if (yield)
1536 {
1537 sender_host_name = NULL;
1538 (void) host_name_lookup();
1539 host_build_sender_fullhost();
1540 }
1541 else
1542 {
8768d548 1543 f.proxy_session_failed = TRUE;
1811cb4c
JH
1544 DEBUG(D_receive)
1545 debug_printf("Failure to extract proxied host, only QUIT allowed\n");
1546 }
1547
1548return;
a3c86431
TL
1549}
1550#endif
1551
059ec3d9
PH
1552/*************************************************
1553* Read one command line *
1554*************************************************/
1555
1556/* Strictly, SMTP commands coming over the net are supposed to end with CRLF.
1557There are sites that don't do this, and in any case internal SMTP probably
1558should check only for LF. Consequently, we check here for LF only. The line
1559ends up with [CR]LF removed from its end. If we get an overlong line, treat as
3ee512ff
PH
1560an unknown command. The command is read into the global smtp_cmd_buffer so that
1561it is available via $smtp_command.
059ec3d9
PH
1562
1563The character reading routine sets up a timeout for each block actually read
1564from the input (which may contain more than one command). We set up a special
1565signal handler that closes down the session on a timeout. Control does not
1566return when it runs.
1567
1568Arguments:
bd8fbe36
JH
1569 check_sync if TRUE, check synchronization rules if global option is TRUE
1570 buffer_lim maximum to buffer in lower layer
059ec3d9
PH
1571
1572Returns: a code identifying the command (enumerated above)
1573*/
1574
1575static int
bd8fbe36 1576smtp_read_command(BOOL check_sync, unsigned buffer_lim)
059ec3d9
PH
1577{
1578int c;
1579int ptr = 0;
059ec3d9
PH
1580BOOL hadnull = FALSE;
1581
9723f966 1582had_command_timeout = 0;
059ec3d9
PH
1583os_non_restarting_signal(SIGALRM, command_timeout_handler);
1584
bd8fbe36 1585while ((c = (receive_getc)(buffer_lim)) != '\n' && c != EOF)
059ec3d9 1586 {
bd8fbe36 1587 if (ptr >= SMTP_CMD_BUFFER_SIZE)
059ec3d9
PH
1588 {
1589 os_non_restarting_signal(SIGALRM, sigalrm_handler);
1590 return OTHER_CMD;
1591 }
1592 if (c == 0)
1593 {
1594 hadnull = TRUE;
1595 c = '?';
1596 }
3ee512ff 1597 smtp_cmd_buffer[ptr++] = c;
059ec3d9
PH
1598 }
1599
1600receive_linecount++; /* For BSMTP errors */
1601os_non_restarting_signal(SIGALRM, sigalrm_handler);
1602
1603/* If hit end of file, return pseudo EOF command. Whether we have a
1604part-line already read doesn't matter, since this is an error state. */
1605
1606if (c == EOF) return EOF_CMD;
1607
1608/* Remove any CR and white space at the end of the line, and terminate the
1609string. */
1610
3ee512ff
PH
1611while (ptr > 0 && isspace(smtp_cmd_buffer[ptr-1])) ptr--;
1612smtp_cmd_buffer[ptr] = 0;
059ec3d9 1613
3ee512ff 1614DEBUG(D_receive) debug_printf("SMTP<< %s\n", smtp_cmd_buffer);
059ec3d9
PH
1615
1616/* NULLs are not allowed in SMTP commands */
1617
1618if (hadnull) return BADCHAR_CMD;
1619
1620/* Scan command list and return identity, having set the data pointer
1621to the start of the actual data characters. Check for SMTP synchronization
1622if required. */
1623
d7978c0f 1624for (smtp_cmd_list * p = cmd_list; p < cmd_list_end; p++)
059ec3d9 1625 {
1811cb4c 1626#ifdef SUPPORT_PROXY
a3c86431 1627 /* Only allow QUIT command if Proxy Protocol parsing failed */
8768d548 1628 if (proxy_session && f.proxy_session_failed && p->cmd != QUIT_CMD)
1811cb4c
JH
1629 continue;
1630#endif
2f460950
JH
1631 if ( p->len
1632 && strncmpic(smtp_cmd_buffer, US p->name, p->len) == 0
1633 && ( smtp_cmd_buffer[p->len-1] == ':' /* "mail from:" or "rcpt to:" */
1634 || smtp_cmd_buffer[p->len] == 0
1635 || smtp_cmd_buffer[p->len] == ' '
1636 ) )
059ec3d9
PH
1637 {
1638 if (smtp_inptr < smtp_inend && /* Outstanding input */
1639 p->cmd < sync_cmd_limit && /* Command should sync */
1640 check_sync && /* Local flag set */
1641 smtp_enforce_sync && /* Global flag set */
1642 sender_host_address != NULL && /* Not local input */
8768d548 1643 !f.sender_host_notsocket) /* Really is a socket */
059ec3d9
PH
1644 return BADSYN_CMD;
1645
ca86f471
PH
1646 /* The variables $smtp_command and $smtp_command_argument point into the
1647 unmodified input buffer. A copy of the latter is taken for actual
1648 processing, so that it can be chopped up into separate parts if necessary,
1649 for example, when processing a MAIL command options such as SIZE that can
1650 follow the sender address. */
059ec3d9 1651
3ee512ff 1652 smtp_cmd_argument = smtp_cmd_buffer + p->len;
ca86f471
PH
1653 while (isspace(*smtp_cmd_argument)) smtp_cmd_argument++;
1654 Ustrcpy(smtp_data_buffer, smtp_cmd_argument);
1655 smtp_cmd_data = smtp_data_buffer;
059ec3d9
PH
1656
1657 /* Count non-mail commands from those hosts that are controlled in this
1658 way. The default is all hosts. We don't waste effort checking the list
1659 until we get a non-mail command, but then cache the result to save checking
1660 again. If there's a DEFER while checking the host, assume it's in the list.
1661
1662 Note that one instance of RSET, EHLO/HELO, and STARTTLS is allowed at the
1663 start of each incoming message by fiddling with the value in the table. */
1664
1665 if (!p->is_mail_cmd)
1666 {
1667 if (count_nonmail == TRUE_UNSET) count_nonmail =
1668 verify_check_host(&smtp_accept_max_nonmail_hosts) != FAIL;
1669 if (count_nonmail && ++nonmail_command_count > smtp_accept_max_nonmail)
1670 return TOO_MANY_NONMAIL_CMD;
1671 }
1672
ca86f471
PH
1673 /* If there is data for a command that does not expect it, generate the
1674 error here. */
059ec3d9 1675
ca86f471 1676 return (p->has_arg || *smtp_cmd_data == 0)? p->cmd : BADARG_CMD;
059ec3d9
PH
1677 }
1678 }
1679
cee5f132 1680#ifdef SUPPORT_PROXY
a3c86431 1681/* Only allow QUIT command if Proxy Protocol parsing failed */
8768d548 1682if (proxy_session && f.proxy_session_failed)
a3c86431
TL
1683 return PROXY_FAIL_IGNORE_CMD;
1684#endif
1685
059ec3d9
PH
1686/* Enforce synchronization for unknown commands */
1687
ecce6d9a
JH
1688if ( smtp_inptr < smtp_inend /* Outstanding input */
1689 && check_sync /* Local flag set */
1690 && smtp_enforce_sync /* Global flag set */
1691 && sender_host_address /* Not local input */
8768d548 1692 && !f.sender_host_notsocket) /* Really is a socket */
059ec3d9
PH
1693 return BADSYN_CMD;
1694
1695return OTHER_CMD;
1696}
1697
1698
1699
1700/*************************************************
1701* Forced closedown of call *
1702*************************************************/
1703
1704/* This function is called from log.c when Exim is dying because of a serious
1705disaster, and also from some other places. If an incoming non-batched SMTP
1706channel is open, it swallows the rest of the incoming message if in the DATA
1707phase, sends the reply string, and gives an error to all subsequent commands
1708except QUIT. The existence of an SMTP call is detected by the non-NULLness of
1709smtp_in.
1710
8f128379
PH
1711Arguments:
1712 message SMTP reply string to send, excluding the code
1713
059ec3d9
PH
1714Returns: nothing
1715*/
1716
1717void
1718smtp_closedown(uschar *message)
1719{
db57e575 1720if (!smtp_in || smtp_batched_input) return;
059ec3d9 1721receive_swallow_smtp();
925ac8e4 1722smtp_printf("421 %s\r\n", FALSE, message);
059ec3d9 1723
bd8fbe36 1724for (;;) switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED))
059ec3d9 1725 {
60d10ce7 1726 case EOF_CMD:
db57e575 1727 return;
059ec3d9 1728
60d10ce7 1729 case QUIT_CMD:
db57e575
JH
1730 smtp_printf("221 %s closing connection\r\n", FALSE, smtp_active_hostname);
1731 mac_smtp_fflush();
1732 return;
059ec3d9 1733
60d10ce7 1734 case RSET_CMD:
db57e575
JH
1735 smtp_printf("250 Reset OK\r\n", FALSE);
1736 break;
059ec3d9 1737
60d10ce7 1738 default:
db57e575
JH
1739 smtp_printf("421 %s\r\n", FALSE, message);
1740 break;
059ec3d9
PH
1741 }
1742}
1743
1744
1745
1746
1747/*************************************************
1748* Set up connection info for logging *
1749*************************************************/
1750
1751/* This function is called when logging information about an SMTP connection.
1752It sets up appropriate source information, depending on the type of connection.
dac79d3e
PH
1753If sender_fullhost is NULL, we are at a very early stage of the connection;
1754just use the IP address.
059ec3d9
PH
1755
1756Argument: none
1757Returns: a string describing the connection
1758*/
1759
1760uschar *
1761smtp_get_connection_info(void)
1762{
f5d25c2b
JH
1763const uschar * hostname = sender_fullhost
1764 ? sender_fullhost : sender_host_address;
dac79d3e 1765
059ec3d9 1766if (host_checking)
dac79d3e 1767 return string_sprintf("SMTP connection from %s", hostname);
059ec3d9 1768
8768d548 1769if (f.sender_host_unknown || f.sender_host_notsocket)
059ec3d9
PH
1770 return string_sprintf("SMTP connection from %s", sender_ident);
1771
8768d548 1772if (f.is_inetd)
dac79d3e 1773 return string_sprintf("SMTP connection from %s (via inetd)", hostname);
059ec3d9 1774
52f12a7c 1775if (LOGGING(incoming_interface) && interface_address)
dac79d3e 1776 return string_sprintf("SMTP connection from %s I=[%s]:%d", hostname,
059ec3d9
PH
1777 interface_address, interface_port);
1778
dac79d3e 1779return string_sprintf("SMTP connection from %s", hostname);
059ec3d9
PH
1780}
1781
1782
1783
01603eec 1784#ifndef DISABLE_TLS
887291d2
JH
1785/* Append TLS-related information to a log line
1786
1787Arguments:
acec9514 1788 g String under construction: allocated string to extend, or NULL
887291d2
JH
1789
1790Returns: Allocated string or NULL
1791*/
acec9514
JH
1792static gstring *
1793s_tlslog(gstring * g)
e45a1c37 1794{
acec9514 1795if (LOGGING(tls_cipher) && tls_in.cipher)
b10c87b3 1796 {
acec9514 1797 g = string_append(g, 2, US" X=", tls_in.cipher);
b10c87b3
JH
1798#ifdef EXPERIMENTAL_TLS_RESUME
1799 if (LOGGING(tls_resumption) && tls_in.resumption & RESUME_USED)
1800 g = string_catn(g, US"*", 1);
1801#endif
1802 }
acec9514
JH
1803if (LOGGING(tls_certificate_verified) && tls_in.cipher)
1804 g = string_append(g, 2, US" CV=", tls_in.certificate_verified? "yes":"no");
1805if (LOGGING(tls_peerdn) && tls_in.peerdn)
1806 g = string_append(g, 3, US" DN=\"", string_printing(tls_in.peerdn), US"\"");
1807if (LOGGING(tls_sni) && tls_in.sni)
1808 g = string_append(g, 3, US" SNI=\"", string_printing(tls_in.sni), US"\"");
1809return g;
e45a1c37
JH
1810}
1811#endif
1812
059ec3d9 1813/*************************************************
b4ed4da0
PH
1814* Log lack of MAIL if so configured *
1815*************************************************/
1816
1817/* This function is called when an SMTP session ends. If the log selector
1818smtp_no_mail is set, write a log line giving some details of what has happened
1819in the SMTP session.
1820
1821Arguments: none
1822Returns: nothing
1823*/
1824
1825void
1826smtp_log_no_mail(void)
1827{
acec9514
JH
1828uschar * sep, * s;
1829gstring * g = NULL;
b4ed4da0 1830
6c6d6e48 1831if (smtp_mailcmd_count > 0 || !LOGGING(smtp_no_mail))
b4ed4da0
PH
1832 return;
1833
db57e575 1834if (sender_host_authenticated)
b4ed4da0 1835 {
acec9514
JH
1836 g = string_append(g, 2, US" A=", sender_host_authenticated);
1837 if (authenticated_id) g = string_append(g, 2, US":", authenticated_id);
b4ed4da0
PH
1838 }
1839
01603eec 1840#ifndef DISABLE_TLS
acec9514 1841g = s_tlslog(g);
3f0945ff 1842#endif
b4ed4da0 1843
acec9514
JH
1844sep = smtp_connection_had[SMTP_HBUFF_SIZE-1] != SCH_NONE ? US" C=..." : US" C=";
1845
d7978c0f 1846for (int i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++)
b4ed4da0
PH
1847 if (smtp_connection_had[i] != SCH_NONE)
1848 {
acec9514 1849 g = string_append(g, 2, sep, smtp_names[smtp_connection_had[i]]);
b4ed4da0
PH
1850 sep = US",";
1851 }
b4ed4da0 1852
d7978c0f 1853for (int i = 0; i < smtp_ch_index; i++)
b4ed4da0 1854 {
acec9514 1855 g = string_append(g, 2, sep, smtp_names[smtp_connection_had[i]]);
b4ed4da0
PH
1856 sep = US",";
1857 }
1858
acec9514
JH
1859if (!(s = string_from_gstring(g))) s = US"";
1860
a2673768 1861log_write(0, LOG_MAIN, "no MAIL in %sSMTP connection from %s D=%s%s",
ee8b8090 1862 f.tcp_in_fastopen ? f.tcp_in_fastopen_data ? US"TFO* " : US"TFO " : US"",
0f1a8658 1863 host_and_ident(FALSE), string_timesince(&smtp_connection_start), s);
b4ed4da0
PH
1864}
1865
1866
a09f2942
JH
1867/* Return list of recent smtp commands */
1868
1869uschar *
1870smtp_cmd_hist(void)
1871{
acec9514
JH
1872gstring * list = NULL;
1873uschar * s;
a09f2942 1874
d7978c0f 1875for (int i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++)
a09f2942 1876 if (smtp_connection_had[i] != SCH_NONE)
acec9514
JH
1877 list = string_append_listele(list, ',', smtp_names[smtp_connection_had[i]]);
1878
d7978c0f 1879for (int i = 0; i < smtp_ch_index; i++)
acec9514
JH
1880 list = string_append_listele(list, ',', smtp_names[smtp_connection_had[i]]);
1881
1882s = string_from_gstring(list);
1883return s ? s : US"";
a09f2942
JH
1884}
1885
1886
1887
b4ed4da0
PH
1888
1889/*************************************************
059ec3d9
PH
1890* Check HELO line and set sender_helo_name *
1891*************************************************/
1892
1893/* Check the format of a HELO line. The data for HELO/EHLO is supposed to be
1894the domain name of the sending host, or an ip literal in square brackets. The
4c04137d 1895argument is placed in sender_helo_name, which is in malloc store, because it
059ec3d9
PH
1896must persist over multiple incoming messages. If helo_accept_junk is set, this
1897host is permitted to send any old junk (needed for some broken hosts).
1898Otherwise, helo_allow_chars can be used for rogue characters in general
1899(typically people want to let in underscores).
1900
1901Argument:
1902 s the data portion of the line (already past any white space)
1903
1904Returns: TRUE or FALSE
1905*/
1906
1907static BOOL
1908check_helo(uschar *s)
1909{
1910uschar *start = s;
1911uschar *end = s + Ustrlen(s);
88752192 1912BOOL yield = fl.helo_accept_junk;
059ec3d9
PH
1913
1914/* Discard any previous helo name */
1915
f3ebb786 1916sender_helo_name = NULL;
059ec3d9
PH
1917
1918/* Skip tests if junk is permitted. */
1919
1920if (!yield)
db57e575 1921
059ec3d9
PH
1922 /* Allow the new standard form for IPv6 address literals, namely,
1923 [IPv6:....], and because someone is bound to use it, allow an equivalent
1924 IPv4 form. Allow plain addresses as well. */
1925
1926 if (*s == '[')
1927 {
1928 if (end[-1] == ']')
1929 {
1930 end[-1] = 0;
1931 if (strncmpic(s, US"[IPv6:", 6) == 0)
1932 yield = (string_is_ip_address(s+6, NULL) == 6);
1933 else if (strncmpic(s, US"[IPv4:", 6) == 0)
1934 yield = (string_is_ip_address(s+6, NULL) == 4);
1935 else
1936 yield = (string_is_ip_address(s+1, NULL) != 0);
1937 end[-1] = ']';
1938 }
1939 }
1940
1941 /* Non-literals must be alpha, dot, hyphen, plus any non-valid chars
1942 that have been configured (usually underscore - sigh). */
1943
db57e575
JH
1944 else if (*s)
1945 for (yield = TRUE; *s; s++)
059ec3d9
PH
1946 if (!isalnum(*s) && *s != '.' && *s != '-' &&
1947 Ustrchr(helo_allow_chars, *s) == NULL)
1948 {
1949 yield = FALSE;
1950 break;
1951 }
059ec3d9
PH
1952
1953/* Save argument if OK */
1954
f3ebb786 1955if (yield) sender_helo_name = string_copy_perm(start, TRUE);
059ec3d9
PH
1956return yield;
1957}
1958
1959
1960
1961
1962
1963/*************************************************
1964* Extract SMTP command option *
1965*************************************************/
1966
ca86f471 1967/* This function picks the next option setting off the end of smtp_cmd_data. It
059ec3d9
PH
1968is called for MAIL FROM and RCPT TO commands, to pick off the optional ESMTP
1969things that can appear there.
1970
1971Arguments:
1972 name point this at the name
1973 value point this at the data string
1974
1975Returns: TRUE if found an option
1976*/
1977
1978static BOOL
1979extract_option(uschar **name, uschar **value)
1980{
1981uschar *n;
ca86f471 1982uschar *v = smtp_cmd_data + Ustrlen(smtp_cmd_data) - 1;
059ec3d9
PH
1983while (isspace(*v)) v--;
1984v[1] = 0;
d7a2c833
JH
1985while (v > smtp_cmd_data && *v != '=' && !isspace(*v))
1986 {
1987 /* Take care to not stop at a space embedded in a quoted local-part */
1988
1989 if (*v == '"') do v--; while (*v != '"' && v > smtp_cmd_data+1);
1990 v--;
1991 }
059ec3d9
PH
1992
1993n = v;
fd98a5c6 1994if (*v == '=')
a2673768 1995 {
fd98a5c6
JH
1996 while(isalpha(n[-1])) n--;
1997 /* RFC says SP, but TAB seen in wild and other major MTAs accept it */
1998 if (!isspace(n[-1])) return FALSE;
1999 n[-1] = 0;
a2673768 2000 }
fd98a5c6 2001else
a2673768 2002 {
fd98a5c6
JH
2003 n++;
2004 if (v == smtp_cmd_data) return FALSE;
a2673768 2005 }
059ec3d9 2006*v++ = 0;
fd98a5c6 2007*name = n;
059ec3d9
PH
2008*value = v;
2009return TRUE;
2010}
2011
2012
2013
2014
2015
059ec3d9
PH
2016/*************************************************
2017* Reset for new message *
2018*************************************************/
2019
2020/* This function is called whenever the SMTP session is reset from
e04bfa34 2021within either of the setup functions; also from the daemon loop.
059ec3d9
PH
2022
2023Argument: the stacking pool storage reset point
2024Returns: nothing
2025*/
2026
f3ebb786 2027void *
059ec3d9
PH
2028smtp_reset(void *reset_point)
2029{
059ec3d9
PH
2030recipients_list = NULL;
2031rcpt_count = rcpt_defer_count = rcpt_fail_count =
2032 raw_recipients_count = recipients_count = recipients_list_max = 0;
2e0c1448 2033message_linecount = 0;
059ec3d9 2034message_size = -1;
71fafd95 2035acl_added_headers = NULL;
e7568d51 2036acl_removed_headers = NULL;
8768d548 2037f.queue_only_policy = FALSE;
2679d413 2038rcpt_smtp_response = NULL;
88752192
JH
2039fl.rcpt_smtp_response_same = TRUE;
2040fl.rcpt_in_progress = FALSE;
8768d548 2041f.deliver_freeze = FALSE; /* Can be set by ACL */
6a3f1455 2042freeze_tell = freeze_tell_config; /* Can be set by ACL */
29aba418 2043fake_response = OK; /* Can be set by ACL */
6951ac6c 2044#ifdef WITH_CONTENT_SCAN
8768d548 2045f.no_mbox_unspool = FALSE; /* Can be set by ACL */
8523533c 2046#endif
8768d548
JH
2047f.submission_mode = FALSE; /* Can be set by ACL */
2048f.suppress_local_fixups = f.suppress_local_fixups_default; /* Can be set by ACL */
2049f.active_local_from_check = local_from_check; /* Can be set by ACL */
2050f.active_local_sender_retain = local_sender_retain; /* Can be set by ACL */
90341c71
JH
2051sending_ip_address = NULL;
2052return_path = sender_address = NULL;
2053sender_data = NULL; /* Can be set by ACL */
c679ee08
JH
2054deliver_localpart_parent = deliver_localpart_orig = NULL;
2055deliver_domain_parent = deliver_domain_orig = NULL;
90341c71 2056callout_address = NULL;
2fe1a124 2057submission_name = NULL; /* Can be set by ACL */
059ec3d9
PH
2058raw_sender = NULL; /* After SMTP rewrite, before qualifying */
2059sender_address_unrewritten = NULL; /* Set only after verify rewrite */
2060sender_verified_list = NULL; /* No senders verified */
2061memset(sender_address_cache, 0, sizeof(sender_address_cache));
2062memset(sender_domain_cache, 0, sizeof(sender_domain_cache));
6c1c3d1d 2063
059ec3d9 2064authenticated_sender = NULL;
8523533c
TK
2065#ifdef EXPERIMENTAL_BRIGHTMAIL
2066bmi_run = 0;
2067bmi_verdicts = NULL;
2068#endif
90341c71 2069dnslist_domain = dnslist_matched = NULL;
01067968
JH
2070#ifdef SUPPORT_SPF
2071spf_header_comment = spf_received = spf_result = spf_smtp_comment = NULL;
2072spf_result_guessed = FALSE;
2073#endif
80a47a2c 2074#ifndef DISABLE_DKIM
d342446f 2075dkim_cur_signer = dkim_signers =
b4757e36 2076dkim_signing_domain = dkim_signing_selector = dkim_signatures = NULL;
d342446f 2077dkim_cur_signer = dkim_signers = dkim_signing_domain = dkim_signing_selector = NULL;
8768d548 2078f.dkim_disable_verify = FALSE;
64b67b65 2079dkim_collect_input = 0;
d342446f
JH
2080dkim_verify_overall = dkim_verify_status = dkim_verify_reason = NULL;
2081dkim_key_length = 0;
f7572e5a 2082#endif
1a2e76e1 2083#ifdef SUPPORT_DMARC
8768d548 2084f.dmarc_has_been_checked = f.dmarc_disable_verify = f.dmarc_enable_forensic = FALSE;
8aeef98a 2085dmarc_domain_policy = dmarc_status = dmarc_status_text =
6372d4c9 2086dmarc_used_domain = NULL;
f7572e5a 2087#endif
01067968
JH
2088#ifdef EXPERIMENTAL_ARC
2089arc_state = arc_state_reason = NULL;
b4757e36 2090#endif
aa368db3
JH
2091dsn_ret = 0;
2092dsn_envid = NULL;
90341c71 2093deliver_host = deliver_host_address = NULL; /* Can be set by ACL */
aa368db3
JH
2094#ifndef DISABLE_PRDR
2095prdr_requested = FALSE;
2096#endif
8c5d388a 2097#ifdef SUPPORT_I18N
d1a13eea
JH
2098message_smtputf8 = FALSE;
2099#endif
059ec3d9
PH
2100body_linecount = body_zerocount = 0;
2101
870f6ba8
TF
2102sender_rate = sender_rate_limit = sender_rate_period = NULL;
2103ratelimiters_mail = NULL; /* Updated by ratelimit ACL condition */
2104 /* Note that ratelimiters_conn persists across resets. */
2105
38a0a95f 2106/* Reset message ACL variables */
47ca6d6c 2107
38a0a95f 2108acl_var_m = NULL;
059ec3d9
PH
2109
2110/* The message body variables use malloc store. They may be set if this is
2111not the first message in an SMTP session and the previous message caused them
2112to be referenced in an ACL. */
2113
90341c71 2114if (message_body)
059ec3d9
PH
2115 {
2116 store_free(message_body);
2117 message_body = NULL;
2118 }
2119
90341c71 2120if (message_body_end)
059ec3d9
PH
2121 {
2122 store_free(message_body_end);
2123 message_body_end = NULL;
2124 }
2125
2126/* Warning log messages are also saved in malloc store. They are saved to avoid
2127repetition in the same message, but it seems right to repeat them for different
4e88a19f 2128messages. */
059ec3d9 2129
90341c71 2130while (acl_warn_logged)
059ec3d9
PH
2131 {
2132 string_item *this = acl_warn_logged;
2133 acl_warn_logged = acl_warn_logged->next;
2134 store_free(this);
2135 }
90341c71 2136store_reset(reset_point);
f3ebb786 2137return store_mark();
059ec3d9
PH
2138}
2139
2140
2141
2142
2143
2144/*************************************************
2145* Initialize for incoming batched SMTP message *
2146*************************************************/
2147
2148/* This function is called from smtp_setup_msg() in the case when
2149smtp_batched_input is true. This happens when -bS is used to pass a whole batch
2150of messages in one file with SMTP commands between them. All errors must be
2151reported by sending a message, and only MAIL FROM, RCPT TO, and DATA are
2152relevant. After an error on a sender, or an invalid recipient, the remainder
2153of the message is skipped. The value of received_protocol is already set.
2154
2155Argument: none
2156Returns: > 0 message successfully started (reached DATA)
2157 = 0 QUIT read or end of file reached
2158 < 0 should not occur
2159*/
2160
2161static int
2162smtp_setup_batch_msg(void)
2163{
2164int done = 0;
f3ebb786 2165rmark reset_point = store_mark();
059ec3d9
PH
2166
2167/* Save the line count at the start of each transaction - single commands
2168like HELO and RSET count as whole transactions. */
2169
2170bsmtp_transaction_linecount = receive_linecount;
2171
2172if ((receive_feof)()) return 0; /* Treat EOF as QUIT */
2173
57cc2785 2174cancel_cutthrough_connection(TRUE, US"smtp_setup_batch_msg");
f3ebb786 2175reset_point = smtp_reset(reset_point); /* Reset for start of message */
059ec3d9
PH
2176
2177/* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
2178value. The values are 2 larger than the required yield of the function. */
2179
2180while (done <= 0)
2181 {
2182 uschar *errmess;
2183 uschar *recipient = NULL;
2184 int start, end, sender_domain, recipient_domain;
2185
bd8fbe36 2186 switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED))
059ec3d9
PH
2187 {
2188 /* The HELO/EHLO commands set sender_address_helo if they have
2189 valid data; otherwise they are ignored, except that they do
2190 a reset of the state. */
2191
2192 case HELO_CMD:
2193 case EHLO_CMD:
2194
db57e575
JH
2195 check_helo(smtp_cmd_data);
2196 /* Fall through */
059ec3d9
PH
2197
2198 case RSET_CMD:
db57e575 2199 cancel_cutthrough_connection(TRUE, US"RSET received");
f3ebb786 2200 reset_point = smtp_reset(reset_point);
db57e575
JH
2201 bsmtp_transaction_linecount = receive_linecount;
2202 break;
059ec3d9
PH
2203
2204
2205 /* The MAIL FROM command requires an address as an operand. All we
2206 do here is to parse it for syntactic correctness. The form "<>" is
2207 a special case which converts into an empty string. The start/end
2208 pointers in the original are not used further for this address, as
2209 it is the canonical extracted address which is all that is kept. */
2210
2211 case MAIL_CMD:
db57e575
JH
2212 smtp_mailcmd_count++; /* Count for no-mail log */
2213 if (sender_address != NULL)
2214 /* The function moan_smtp_batch() does not return. */
2215 moan_smtp_batch(smtp_cmd_buffer, "503 Sender already given");
059ec3d9 2216
db57e575
JH
2217 if (smtp_cmd_data[0] == 0)
2218 /* The function moan_smtp_batch() does not return. */
2219 moan_smtp_batch(smtp_cmd_buffer, "501 MAIL FROM must have an address operand");
059ec3d9 2220
db57e575 2221 /* Reset to start of message */
059ec3d9 2222
db57e575 2223 cancel_cutthrough_connection(TRUE, US"MAIL received");
f3ebb786 2224 reset_point = smtp_reset(reset_point);
059ec3d9 2225
db57e575 2226 /* Apply SMTP rewrite */
059ec3d9 2227
db57e575
JH
2228 raw_sender = ((rewrite_existflags & rewrite_smtp) != 0)?
2229 rewrite_one(smtp_cmd_data, rewrite_smtp|rewrite_smtp_sender, NULL, FALSE,
2230 US"", global_rewrite_rules) : smtp_cmd_data;
059ec3d9 2231
db57e575 2232 /* Extract the address; the TRUE flag allows <> as valid */
059ec3d9 2233
db57e575
JH
2234 raw_sender =
2235 parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain,
2236 TRUE);
059ec3d9 2237
db57e575
JH
2238 if (!raw_sender)
2239 /* The function moan_smtp_batch() does not return. */
2240 moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
059ec3d9 2241
db57e575 2242 sender_address = string_copy(raw_sender);
059ec3d9 2243
db57e575 2244 /* Qualify unqualified sender addresses if permitted to do so. */
059ec3d9 2245
db57e575
JH
2246 if ( !sender_domain
2247 && sender_address[0] != 0 && sender_address[0] != '@')
8768d548 2248 if (f.allow_unqualified_sender)
db57e575
JH
2249 {
2250 sender_address = rewrite_address_qualify(sender_address, FALSE);
2251 DEBUG(D_receive) debug_printf("unqualified address %s accepted "
2252 "and rewritten\n", raw_sender);
2253 }
2254 /* The function moan_smtp_batch() does not return. */
2255 else
2256 moan_smtp_batch(smtp_cmd_buffer, "501 sender address must contain "
2257 "a domain");
2258 break;
059ec3d9
PH
2259
2260
2261 /* The RCPT TO command requires an address as an operand. All we do
2262 here is to parse it for syntactic correctness. There may be any number
2263 of RCPT TO commands, specifying multiple senders. We build them all into
2264 a data structure that is in argc/argv format. The start/end values
2265 given by parse_extract_address are not used, as we keep only the
2266 extracted address. */
2267
2268 case RCPT_CMD:
db57e575
JH
2269 if (!sender_address)
2270 /* The function moan_smtp_batch() does not return. */
2271 moan_smtp_batch(smtp_cmd_buffer, "503 No sender yet given");
059ec3d9 2272
db57e575
JH
2273 if (smtp_cmd_data[0] == 0)
2274 /* The function moan_smtp_batch() does not return. */
2275 moan_smtp_batch(smtp_cmd_buffer,
2276 "501 RCPT TO must have an address operand");
059ec3d9 2277
db57e575 2278 /* Check maximum number allowed */
059ec3d9 2279
db57e575
JH
2280 if (recipients_max > 0 && recipients_count + 1 > recipients_max)
2281 /* The function moan_smtp_batch() does not return. */
2282 moan_smtp_batch(smtp_cmd_buffer, "%s too many recipients",
2283 recipients_max_reject? "552": "452");
059ec3d9 2284
db57e575
JH
2285 /* Apply SMTP rewrite, then extract address. Don't allow "<>" as a
2286 recipient address */
059ec3d9 2287
db57e575
JH
2288 recipient = rewrite_existflags & rewrite_smtp
2289 ? rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
2290 global_rewrite_rules)
2291 : smtp_cmd_data;
059ec3d9 2292
db57e575
JH
2293 recipient = parse_extract_address(recipient, &errmess, &start, &end,
2294 &recipient_domain, FALSE);
059ec3d9 2295
db57e575
JH
2296 if (!recipient)
2297 /* The function moan_smtp_batch() does not return. */
2298 moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
059ec3d9 2299
db57e575
JH
2300 /* If the recipient address is unqualified, qualify it if permitted. Then
2301 add it to the list of recipients. */
059ec3d9 2302
db57e575 2303 if (!recipient_domain)
8768d548 2304 if (f.allow_unqualified_recipient)
db57e575
JH
2305 {
2306 DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
2307 recipient);
2308 recipient = rewrite_address_qualify(recipient, TRUE);
2309 }
2310 /* The function moan_smtp_batch() does not return. */
2311 else
2312 moan_smtp_batch(smtp_cmd_buffer,
2313 "501 recipient address must contain a domain");
2314
2315 receive_add_recipient(recipient, -1);
2316 break;
059ec3d9
PH
2317
2318
2319 /* The DATA command is legal only if it follows successful MAIL FROM
2320 and RCPT TO commands. This function is complete when a valid DATA
2321 command is encountered. */
2322
2323 case DATA_CMD:
db57e575
JH
2324 if (!sender_address || recipients_count <= 0)
2325 /* The function moan_smtp_batch() does not return. */
2326 if (!sender_address)
2327 moan_smtp_batch(smtp_cmd_buffer,
2328 "503 MAIL FROM:<sender> command must precede DATA");
2329 else
2330 moan_smtp_batch(smtp_cmd_buffer,
2331 "503 RCPT TO:<recipient> must precede DATA");
059ec3d9 2332 else
db57e575
JH
2333 {
2334 done = 3; /* DATA successfully achieved */
2335 message_ended = END_NOTENDED; /* Indicate in middle of message */
2336 }
2337 break;
059ec3d9
PH
2338
2339
2340 /* The VRFY, EXPN, HELP, ETRN, and NOOP commands are ignored. */
2341
2342 case VRFY_CMD:
2343 case EXPN_CMD:
2344 case HELP_CMD:
2345 case NOOP_CMD:
2346 case ETRN_CMD:
db57e575
JH
2347 bsmtp_transaction_linecount = receive_linecount;
2348 break;
059ec3d9
PH
2349
2350
2351 case EOF_CMD:
2352 case QUIT_CMD:
db57e575
JH
2353 done = 2;
2354 break;
059ec3d9
PH
2355
2356
2357 case BADARG_CMD:
db57e575
JH
2358 /* The function moan_smtp_batch() does not return. */
2359 moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected argument data");
2360 break;
059ec3d9
PH
2361
2362
2363 case BADCHAR_CMD:
db57e575
JH
2364 /* The function moan_smtp_batch() does not return. */
2365 moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected NULL in SMTP command");
2366 break;
059ec3d9
PH
2367
2368
2369 default:
db57e575
JH
2370 /* The function moan_smtp_batch() does not return. */
2371 moan_smtp_batch(smtp_cmd_buffer, "500 Command unrecognized");
2372 break;
059ec3d9
PH
2373 }
2374 }
2375
2376return done - 2; /* Convert yield values */
2377}
2378
2379
2380
2381
01603eec 2382#ifndef DISABLE_TLS
cf0c6164
JH
2383static BOOL
2384smtp_log_tls_fail(uschar * errstr)
2385{
2386uschar * conn_info = smtp_get_connection_info();
2387
2388if (Ustrncmp(conn_info, US"SMTP ", 5) == 0) conn_info += 5;
2389/* I'd like to get separated H= here, but too hard for now */
2390
2391log_write(0, LOG_MAIN, "TLS error on %s %s", conn_info, errstr);
2392return FALSE;
2393}
13c7874e 2394#endif
cf0c6164
JH
2395
2396
a2673768
JH
2397
2398
2399#ifdef TCP_FASTOPEN
2400static void
2401tfo_in_check(void)
2402{
2403# ifdef TCP_INFO
2404struct tcp_info tinfo;
2405socklen_t len = sizeof(tinfo);
2406
ee8b8090 2407if (getsockopt(fileno(smtp_out), IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0)
73a10da9 2408# ifdef TCPI_OPT_SYN_DATA /* FreeBSD 11,12 do not seem to have this yet */
ee8b8090
JH
2409 if (tinfo.tcpi_options & TCPI_OPT_SYN_DATA)
2410 {
73a10da9
JH
2411 DEBUG(D_receive)
2412 debug_printf("TCP_FASTOPEN mode connection (ACKd data-on-SYN)\n");
ee8b8090
JH
2413 f.tcp_in_fastopen_data = f.tcp_in_fastopen = TRUE;
2414 }
dbcb6d0a 2415 else
73a10da9
JH
2416# endif
2417 if (tinfo.tcpi_state == TCP_SYN_RECV) /* Not seen on FreeBSD 12.1 */
2418 {
2419 DEBUG(D_receive)
2420 debug_printf("TCP_FASTOPEN mode connection (state TCP_SYN_RECV)\n");
2421 f.tcp_in_fastopen = TRUE;
2422 }
2423# ifdef __FreeBSD__
2424 else if (tinfo.tcpi_options & TCPOPT_FAST_OPEN)
ee8b8090 2425 {
73a10da9
JH
2426 /* This only tells us that some combination of the TCP options was used. It
2427 can be a TFO-R received (as of 12.1). However, pretend it shows real usage
2428 (that an acceptable TFO-C was received and acted on). Ignore the possibility
2429 of data-on-SYN for now. */
2430 DEBUG(D_receive) debug_printf("TCP_FASTOPEN mode connection (TFO option used)\n");
ee8b8090
JH
2431 f.tcp_in_fastopen = TRUE;
2432 }
73a10da9 2433# endif
a2673768 2434# endif
73a10da9
JH
2435else DEBUG(D_receive)
2436 debug_printf("TCP_INFO getsockopt: %s\n", strerror(errno));
a2673768
JH
2437}
2438#endif
2439
2440
059ec3d9
PH
2441/*************************************************
2442* Start an SMTP session *
2443*************************************************/
2444
2445/* This function is called at the start of an SMTP session. Thereafter,
2446smtp_setup_msg() is called to initiate each separate message. This
2447function does host-specific testing, and outputs the banner line.
2448
2449Arguments: none
2450Returns: FALSE if the session can not continue; something has
2451 gone wrong, or the connection to the host is blocked
2452*/
2453
2454BOOL
2455smtp_start_session(void)
2456{
acec9514 2457int esclen;
4e88a19f
PH
2458uschar *user_msg, *log_msg;
2459uschar *code, *esc;
acec9514
JH
2460uschar *p, *s;
2461gstring * ss;
059ec3d9 2462
0f1a8658 2463gettimeofday(&smtp_connection_start, NULL);
b4ed4da0
PH
2464for (smtp_ch_index = 0; smtp_ch_index < SMTP_HBUFF_SIZE; smtp_ch_index++)
2465 smtp_connection_had[smtp_ch_index] = SCH_NONE;
2466smtp_ch_index = 0;
2467
00f00ca5
PH
2468/* Default values for certain variables */
2469
88752192 2470fl.helo_seen = fl.esmtp = fl.helo_accept_junk = FALSE;
b4ed4da0 2471smtp_mailcmd_count = 0;
059ec3d9
PH
2472count_nonmail = TRUE_UNSET;
2473synprot_error_count = unknown_command_count = nonmail_command_count = 0;
2474smtp_delay_mail = smtp_rlm_base;
88752192 2475fl.auth_advertised = FALSE;
8768d548
JH
2476f.smtp_in_pipelining_advertised = f.smtp_in_pipelining_used = FALSE;
2477f.pipelining_enable = TRUE;
059ec3d9 2478sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING;
88752192 2479fl.smtp_exit_function_called = FALSE; /* For avoiding loop in not-quit exit */
059ec3d9 2480
33d73e3b
PH
2481/* If receiving by -bs from a trusted user, or testing with -bh, we allow
2482authentication settings from -oMaa to remain in force. */
2483
8768d548 2484if (!host_checking && !f.sender_host_notsocket)
c44ff8be 2485 sender_host_auth_pubname = sender_host_authenticated = NULL;
059ec3d9
PH
2486authenticated_by = NULL;
2487
01603eec 2488#ifndef DISABLE_TLS
5b195d6b 2489tls_in.ver = tls_in.cipher = tls_in.peerdn = NULL;
9d1c15ef
JH
2490tls_in.ourcert = tls_in.peercert = NULL;
2491tls_in.sni = NULL;
44662487 2492tls_in.ocsp = OCSP_NOT_REQ;
88752192 2493fl.tls_advertised = FALSE;
059ec3d9 2494#endif
88752192 2495fl.dsn_advertised = FALSE;
8c5d388a 2496#ifdef SUPPORT_I18N
88752192 2497fl.smtputf8_advertised = FALSE;
d1a13eea 2498#endif
059ec3d9
PH
2499
2500/* Reset ACL connection variables */
2501
38a0a95f 2502acl_var_c = NULL;
059ec3d9 2503
f3ebb786 2504/* Allow for trailing 0 in the command and data buffers. Tainted. */
3ee512ff 2505
f3ebb786 2506smtp_cmd_buffer = store_get_perm(2*SMTP_CMD_BUFFER_SIZE + 2, TRUE);
40c90bca 2507
2416c261 2508smtp_cmd_buffer[0] = 0;
bd8fbe36 2509smtp_data_buffer = smtp_cmd_buffer + SMTP_CMD_BUFFER_SIZE + 1;
059ec3d9
PH
2510
2511/* For batched input, the protocol setting can be overridden from the
2512command line by a trusted caller. */
2513
2514if (smtp_batched_input)
2515 {
40c90bca 2516 if (!received_protocol) received_protocol = US"local-bsmtp";
059ec3d9
PH
2517 }
2518
2519/* For non-batched SMTP input, the protocol setting is forced here. It will be
2520reset later if any of EHLO/AUTH/STARTTLS are received. */
2521
2522else
2523 received_protocol =
e524074d 2524 (sender_host_address ? protocols : protocols_local) [pnormal];
059ec3d9
PH
2525
2526/* Set up the buffer for inputting using direct read() calls, and arrange to
ecce6d9a
JH
2527call the local functions instead of the standard C ones. Place a NUL at the
2528end of the buffer to safety-stop C-string reads from it. */
059ec3d9 2529
5903c6ff 2530if (!(smtp_inbuffer = US malloc(IN_BUFFER_SIZE)))
059ec3d9 2531 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "malloc() failed for SMTP input buffer");
ecce6d9a 2532smtp_inbuffer[IN_BUFFER_SIZE-1] = '\0';
40c90bca 2533
059ec3d9 2534receive_getc = smtp_getc;
0d81dabc 2535receive_getbuf = smtp_getbuf;
584e96c6 2536receive_get_cache = smtp_get_cache;
059ec3d9
PH
2537receive_ungetc = smtp_ungetc;
2538receive_feof = smtp_feof;
2539receive_ferror = smtp_ferror;
58eb016e 2540receive_smtp_buffered = smtp_buffered;
059ec3d9
PH
2541smtp_inptr = smtp_inend = smtp_inbuffer;
2542smtp_had_eof = smtp_had_error = 0;
2543
2544/* Set up the message size limit; this may be host-specific */
2545
d45b1de8 2546thismessage_size_limit = expand_string_integer(message_size_limit, TRUE);
db57e575 2547if (expand_string_message)
059ec3d9
PH
2548 {
2549 if (thismessage_size_limit == -1)
2550 log_write(0, LOG_MAIN|LOG_PANIC, "unable to expand message_size_limit: "
2551 "%s", expand_string_message);
2552 else
2553 log_write(0, LOG_MAIN|LOG_PANIC, "invalid message_size_limit: "
2554 "%s", expand_string_message);
2555 smtp_closedown(US"Temporary local problem - please try later");
2556 return FALSE;
2557 }
2558
2559/* When a message is input locally via the -bs or -bS options, sender_host_
2560unknown is set unless -oMa was used to force an IP address, in which case it
2561is checked like a real remote connection. When -bs is used from inetd, this
2562flag is not set, causing the sending host to be checked. The code that deals
2563with IP source routing (if configured) is never required for -bs or -bS and
2564the flag sender_host_notsocket is used to suppress it.
2565
2566If smtp_accept_max and smtp_accept_reserve are set, keep some connections in
2567reserve for certain hosts and/or networks. */
2568
8768d548 2569if (!f.sender_host_unknown)
059ec3d9
PH
2570 {
2571 int rc;
2572 BOOL reserved_host = FALSE;
2573
2574 /* Look up IP options (source routing info) on the socket if this is not an
2575 -oMa "host", and if any are found, log them and drop the connection.
2576
2577 Linux (and others now, see below) is different to everyone else, so there
2578 has to be some conditional compilation here. Versions of Linux before 2.1.15
2579 used a structure whose name was "options". Somebody finally realized that
2580 this name was silly, and it got changed to "ip_options". I use the
2581 newer name here, but there is a fudge in the script that sets up os.h
2582 to define a macro in older Linux systems.
2583
2584 Sigh. Linux is a fast-moving target. Another generation of Linux uses
2585 glibc 2, which has chosen ip_opts for the structure name. This is now
2586 really a glibc thing rather than a Linux thing, so the condition name
2587 has been changed to reflect this. It is relevant also to GNU/Hurd.
2588
2589 Mac OS 10.x (Darwin) is like the later glibc versions, but without the
2590 setting of the __GLIBC__ macro, so we can't detect it automatically. There's
2591 a special macro defined in the os.h file.
2592
2593 Some DGUX versions on older hardware appear not to support IP options at
2594 all, so there is now a general macro which can be set to cut out this
2595 support altogether.
2596
2597 How to do this properly in IPv6 is not yet known. */
2598
e0574cb5 2599#if !HAVE_IPV6 && !defined(NO_IP_OPTIONS)
059ec3d9
PH
2600
2601 #ifdef GLIBC_IP_OPTIONS
2602 #if (!defined __GLIBC__) || (__GLIBC__ < 2)
2603 #define OPTSTYLE 1
2604 #else
2605 #define OPTSTYLE 2
2606 #endif
2607 #elif defined DARWIN_IP_OPTIONS
2608 #define OPTSTYLE 2
2609 #else
2610 #define OPTSTYLE 3
2611 #endif
2612
8768d548 2613 if (!host_checking && !f.sender_host_notsocket)
059ec3d9
PH
2614 {
2615 #if OPTSTYLE == 1
36a3b041 2616 EXIM_SOCKLEN_T optlen = sizeof(struct ip_options) + MAX_IPOPTLEN;
f3ebb786 2617 struct ip_options *ipopt = store_get(optlen, FALSE);
059ec3d9
PH
2618 #elif OPTSTYLE == 2
2619 struct ip_opts ipoptblock;
2620 struct ip_opts *ipopt = &ipoptblock;
36a3b041 2621 EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
059ec3d9
PH
2622 #else
2623 struct ipoption ipoptblock;
2624 struct ipoption *ipopt = &ipoptblock;
36a3b041 2625 EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
059ec3d9
PH
2626 #endif
2627
2628 /* Occasional genuine failures of getsockopt() have been seen - for
2629 example, "reset by peer". Therefore, just log and give up on this
2630 call, unless the error is ENOPROTOOPT. This error is given by systems
2631 that have the interfaces but not the mechanism - e.g. GNU/Hurd at the time
2632 of writing. So for that error, carry on - we just can't do an IP options
2633 check. */
2634
2635 DEBUG(D_receive) debug_printf("checking for IP options\n");
2636
5903c6ff 2637 if (getsockopt(fileno(smtp_out), IPPROTO_IP, IP_OPTIONS, US (ipopt),
059ec3d9
PH
2638 &optlen) < 0)
2639 {
2640 if (errno != ENOPROTOOPT)
2641 {
2642 log_write(0, LOG_MAIN, "getsockopt() failed from %s: %s",
2643 host_and_ident(FALSE), strerror(errno));
925ac8e4 2644 smtp_printf("451 SMTP service not available\r\n", FALSE);
059ec3d9
PH
2645 return FALSE;
2646 }
2647 }
2648
2649 /* Deal with any IP options that are set. On the systems I have looked at,
2650 the value of MAX_IPOPTLEN has been 40, meaning that there should never be
2651 more logging data than will fit in big_buffer. Nevertheless, after somebody
2652 questioned this code, I've added in some paranoid checking. */
2653
2654 else if (optlen > 0)
2655 {
2656 uschar *p = big_buffer;
2657 uschar *pend = big_buffer + big_buffer_size;
d7978c0f 2658 uschar *adptr;
059ec3d9
PH
2659 int optcount;
2660 struct in_addr addr;
2661
2662 #if OPTSTYLE == 1
5903c6ff 2663 uschar *optstart = US (ipopt->__data);
059ec3d9 2664 #elif OPTSTYLE == 2
5903c6ff 2665 uschar *optstart = US (ipopt->ip_opts);
059ec3d9 2666 #else
5903c6ff 2667 uschar *optstart = US (ipopt->ipopt_list);
059ec3d9
PH
2668 #endif
2669
2670 DEBUG(D_receive) debug_printf("IP options exist\n");
2671
2672 Ustrcpy(p, "IP options on incoming call:");
2673 p += Ustrlen(p);
2674
d7978c0f 2675 for (uschar * opt = optstart; opt && opt < US (ipopt) + optlen; )
059ec3d9
PH
2676 switch (*opt)
2677 {
2678 case IPOPT_EOL:
2679 opt = NULL;
2680 break;
2681
2682 case IPOPT_NOP:
2683 opt++;
2684 break;
2685
2686 case IPOPT_SSRR:
2687 case IPOPT_LSRR:
2688 if (!string_format(p, pend-p, " %s [@%s",
2689 (*opt == IPOPT_SSRR)? "SSRR" : "LSRR",
2690 #if OPTSTYLE == 1
2691 inet_ntoa(*((struct in_addr *)(&(ipopt->faddr))))))
2692 #elif OPTSTYLE == 2
2693 inet_ntoa(ipopt->ip_dst)))
2694 #else
2695 inet_ntoa(ipopt->ipopt_dst)))
2696 #endif
2697 {
2698 opt = NULL;
2699 break;
2700 }
2701
2702 p += Ustrlen(p);
2703 optcount = (opt[1] - 3) / sizeof(struct in_addr);
2704 adptr = opt + 3;
2705 while (optcount-- > 0)
2706 {
2707 memcpy(&addr, adptr, sizeof(addr));
2708 if (!string_format(p, pend - p - 1, "%s%s",
2709 (optcount == 0)? ":" : "@", inet_ntoa(addr)))
2710 {
2711 opt = NULL;
2712 break;
2713 }
2714 p += Ustrlen(p);
2715 adptr += sizeof(struct in_addr);
2716 }
2717 *p++ = ']';
2718 opt += opt[1];
2719 break;
2720
2721 default:
2722 {
059ec3d9
PH
2723 if (pend - p < 4 + 3*opt[1]) { opt = NULL; break; }
2724 Ustrcat(p, "[ ");
2725 p += 2;
d7978c0f 2726 for (int i = 0; i < opt[1]; i++)
5976eb99 2727 p += sprintf(CS p, "%2.2x ", opt[i]);
059ec3d9
PH
2728 *p++ = ']';
2729 }
2730 opt += opt[1];
2731 break;
2732 }
059ec3d9
PH
2733
2734 *p = 0;
2735 log_write(0, LOG_MAIN, "%s", big_buffer);
2736
2737 /* Refuse any call with IP options. This is what tcpwrappers 7.5 does. */
2738
2739 log_write(0, LOG_MAIN|LOG_REJECT,
2740 "connection from %s refused (IP options)", host_and_ident(FALSE));
2741
925ac8e4 2742 smtp_printf("554 SMTP service not available\r\n", FALSE);
059ec3d9
PH
2743 return FALSE;
2744 }
2745
2746 /* Length of options = 0 => there are no options */
2747
2748 else DEBUG(D_receive) debug_printf("no IP options found\n");
2749 }
e0574cb5 2750#endif /* HAVE_IPV6 && !defined(NO_IP_OPTIONS) */
059ec3d9
PH
2751
2752 /* Set keep-alive in socket options. The option is on by default. This
2753 setting is an attempt to get rid of some hanging connections that stick in
2754 read() when the remote end (usually a dialup) goes away. */
2755
8768d548 2756 if (smtp_accept_keepalive && !f.sender_host_notsocket)
059ec3d9
PH
2757 ip_keepalive(fileno(smtp_out), sender_host_address, FALSE);
2758
2759 /* If the current host matches host_lookup, set the name by doing a
2760 reverse lookup. On failure, sender_host_name will be NULL and
2761 host_lookup_failed will be TRUE. This may or may not be serious - optional
2762 checks later. */
2763
2764 if (verify_check_host(&host_lookup) == OK)
2765 {
2766 (void)host_name_lookup();
2767 host_build_sender_fullhost();
2768 }
2769
2770 /* Delay this until we have the full name, if it is looked up. */
2771
2772 set_process_info("handling incoming connection from %s",
2773 host_and_ident(FALSE));
2774
1ad6489e
JH
2775 /* Expand smtp_receive_timeout, if needed */
2776
2777 if (smtp_receive_timeout_s)
2778 {
2779 uschar * exp;
2780 if ( !(exp = expand_string(smtp_receive_timeout_s))
2781 || !(*exp)
2782 || (smtp_receive_timeout = readconf_readtime(exp, 0, FALSE)) < 0
2783 )
2784 log_write(0, LOG_MAIN|LOG_PANIC,
2785 "bad value for smtp_receive_timeout: '%s'", exp ? exp : US"");
2786 }
2787
059ec3d9
PH
2788 /* Test for explicit connection rejection */
2789
2790 if (verify_check_host(&host_reject_connection) == OK)
2791 {
2792 log_write(L_connection_reject, LOG_MAIN|LOG_REJECT, "refused connection "
2793 "from %s (host_reject_connection)", host_and_ident(FALSE));
925ac8e4 2794 smtp_printf("554 SMTP service not available\r\n", FALSE);
059ec3d9
PH
2795 return FALSE;
2796 }
2797
afb3eaaf
PH
2798 /* Test with TCP Wrappers if so configured. There is a problem in that
2799 hosts_ctl() returns 0 (deny) under a number of system failure circumstances,
2800 such as disks dying. In these cases, it is desirable to reject with a 4xx
2801 error instead of a 5xx error. There isn't a "right" way to detect such
2802 problems. The following kludge is used: errno is zeroed before calling
2803 hosts_ctl(). If the result is "reject", a 5xx error is given only if the
2804 value of errno is 0 or ENOENT (which happens if /etc/hosts.{allow,deny} does
2805 not exist). */
059ec3d9 2806
1811cb4c 2807#ifdef USE_TCP_WRAPPERS
afb3eaaf 2808 errno = 0;
1811cb4c 2809 if (!(tcp_wrappers_name = expand_string(tcp_wrappers_daemon_name)))
5dc43717
JJ
2810 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" "
2811 "(tcp_wrappers_name) failed: %s", string_printing(tcp_wrappers_name),
2812 expand_string_message);
1811cb4c 2813
5dc43717 2814 if (!hosts_ctl(tcp_wrappers_name,
1811cb4c
JH
2815 sender_host_name ? CS sender_host_name : STRING_UNKNOWN,
2816 sender_host_address ? CS sender_host_address : STRING_UNKNOWN,
2817 sender_ident ? CS sender_ident : STRING_UNKNOWN))
059ec3d9 2818 {
afb3eaaf
PH
2819 if (errno == 0 || errno == ENOENT)
2820 {
2821 HDEBUG(D_receive) debug_printf("tcp wrappers rejection\n");
2822 log_write(L_connection_reject,
2823 LOG_MAIN|LOG_REJECT, "refused connection from %s "
2824 "(tcp wrappers)", host_and_ident(FALSE));
925ac8e4 2825 smtp_printf("554 SMTP service not available\r\n", FALSE);
afb3eaaf
PH
2826 }
2827 else
2828 {
2829 int save_errno = errno;
2830 HDEBUG(D_receive) debug_printf("tcp wrappers rejected with unexpected "
2831 "errno value %d\n", save_errno);
2832 log_write(L_connection_reject,
2833 LOG_MAIN|LOG_REJECT, "temporarily refused connection from %s "
2834 "(tcp wrappers errno=%d)", host_and_ident(FALSE), save_errno);
925ac8e4 2835 smtp_printf("451 Temporary local problem - please try later\r\n", FALSE);
afb3eaaf 2836 }
059ec3d9
PH
2837 return FALSE;
2838 }
1811cb4c 2839#endif
059ec3d9 2840
b01dd148
PH
2841 /* Check for reserved slots. The value of smtp_accept_count has already been
2842 incremented to include this process. */
059ec3d9
PH
2843
2844 if (smtp_accept_max > 0 &&
b01dd148 2845 smtp_accept_count > smtp_accept_max - smtp_accept_reserve)
059ec3d9
PH
2846 {
2847 if ((rc = verify_check_host(&smtp_reserve_hosts)) != OK)
2848 {
2849 log_write(L_connection_reject,
2850 LOG_MAIN, "temporarily refused connection from %s: not in "
2851 "reserve list: connected=%d max=%d reserve=%d%s",
b01dd148 2852 host_and_ident(FALSE), smtp_accept_count - 1, smtp_accept_max,
059ec3d9
PH
2853 smtp_accept_reserve, (rc == DEFER)? " (lookup deferred)" : "");
2854 smtp_printf("421 %s: Too many concurrent SMTP connections; "
925ac8e4 2855 "please try again later\r\n", FALSE, smtp_active_hostname);
059ec3d9
PH
2856 return FALSE;
2857 }
2858 reserved_host = TRUE;
2859 }
2860
2861 /* If a load level above which only messages from reserved hosts are
2862 accepted is set, check the load. For incoming calls via the daemon, the
2863 check is done in the superior process if there are no reserved hosts, to
2864 save a fork. In all cases, the load average will already be available
2865 in a global variable at this point. */
2866
2867 if (smtp_load_reserve >= 0 &&
2868 load_average > smtp_load_reserve &&
2869 !reserved_host &&
2870 verify_check_host(&smtp_reserve_hosts) != OK)
2871 {
2872 log_write(L_connection_reject,
2873 LOG_MAIN, "temporarily refused connection from %s: not in "
2874 "reserve list and load average = %.2f", host_and_ident(FALSE),
2875 (double)load_average/1000.0);
925ac8e4 2876 smtp_printf("421 %s: Too much load; please try again later\r\n", FALSE,
059ec3d9
PH
2877 smtp_active_hostname);
2878 return FALSE;
2879 }
2880
2881 /* Determine whether unqualified senders or recipients are permitted
2882 for this host. Unfortunately, we have to do this every time, in order to
2883 set the flags so that they can be inspected when considering qualifying
2884 addresses in the headers. For a site that permits no qualification, this
2885 won't take long, however. */
2886
8768d548 2887 f.allow_unqualified_sender =
059ec3d9
PH
2888 verify_check_host(&sender_unqualified_hosts) == OK;
2889
8768d548 2890 f.allow_unqualified_recipient =
059ec3d9
PH
2891 verify_check_host(&recipient_unqualified_hosts) == OK;
2892
2893 /* Determine whether HELO/EHLO is required for this host. The requirement
2894 can be hard or soft. */
2895
88752192
JH
2896 fl.helo_required = verify_check_host(&helo_verify_hosts) == OK;
2897 if (!fl.helo_required)
2898 fl.helo_verify = verify_check_host(&helo_try_verify_hosts) == OK;
059ec3d9
PH
2899
2900 /* Determine whether this hosts is permitted to send syntactic junk
2901 after a HELO or EHLO command. */
2902
88752192 2903 fl.helo_accept_junk = verify_check_host(&helo_accept_junk_hosts) == OK;
059ec3d9
PH
2904 }
2905
2906/* For batch SMTP input we are now done. */
2907
2908if (smtp_batched_input) return TRUE;
2909
a3c86431
TL
2910/* If valid Proxy Protocol source is connecting, set up session.
2911 * Failure will not allow any SMTP function other than QUIT. */
1811cb4c
JH
2912
2913#ifdef SUPPORT_PROXY
a3c86431 2914proxy_session = FALSE;
8768d548 2915f.proxy_session_failed = FALSE;
a3c86431 2916if (check_proxy_protocol_host())
1811cb4c
JH
2917 setup_proxy_protocol_host();
2918#endif
2919
2920 /* Start up TLS if tls_on_connect is set. This is for supporting the legacy
2921 smtps port for use with older style SSL MTAs. */
2922
01603eec 2923#ifndef DISABLE_TLS
69d8eed7
JH
2924 if (tls_in.on_connect)
2925 {
2926 if (tls_server_start(tls_require_ciphers, &user_msg) != OK)
2927 return smtp_log_tls_fail(user_msg);
2928 cmd_list[CMD_LIST_TLS_AUTH].is_mail_cmd = TRUE;
2929 }
a3c86431
TL
2930#endif
2931
1811cb4c 2932/* Run the connect ACL if it exists */
059ec3d9 2933
4e88a19f 2934user_msg = NULL;
3cc3f762 2935if (acl_smtp_connect)
059ec3d9
PH
2936 {
2937 int rc;
3cc3f762
JH
2938 if ((rc = acl_check(ACL_WHERE_CONNECT, NULL, acl_smtp_connect, &user_msg,
2939 &log_msg)) != OK)
059ec3d9 2940 {
3cc3f762 2941 (void) smtp_handle_acl_fail(ACL_WHERE_CONNECT, rc, user_msg, log_msg);
059ec3d9
PH
2942 return FALSE;
2943 }
2944 }
2945
2946/* Output the initial message for a two-way SMTP connection. It may contain
2947newlines, which then cause a multi-line response to be given. */
2948
4e88a19f
PH
2949code = US"220"; /* Default status code */
2950esc = US""; /* Default extended status code */
2951esclen = 0; /* Length of esc */
2952
d4ff61d1 2953if (!user_msg)
4e88a19f 2954 {
d4ff61d1 2955 if (!(s = expand_string(smtp_banner)))
4e88a19f
PH
2956 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" (smtp_banner) "
2957 "failed: %s", smtp_banner, expand_string_message);
2958 }
2959else
2960 {
2961 int codelen = 3;
2962 s = user_msg;
4f6ae5c3 2963 smtp_message_code(&code, &codelen, &s, NULL, TRUE);
d6a96edc 2964 if (codelen > 4)
4e88a19f
PH
2965 {
2966 esc = code + 4;
2967 esclen = codelen - 4;
2968 }
2969 }
059ec3d9
PH
2970
2971/* Remove any terminating newlines; might as well remove trailing space too */
2972
2973p = s + Ustrlen(s);
2974while (p > s && isspace(p[-1])) p--;
2975*p = 0;
2976
2977/* It seems that CC:Mail is braindead, and assumes that the greeting message
2978is all contained in a single IP packet. The original code wrote out the
2979greeting using several calls to fprint/fputc, and on busy servers this could
2980cause it to be split over more than one packet - which caused CC:Mail to fall
2981over when it got the second part of the greeting after sending its first
2982command. Sigh. To try to avoid this, build the complete greeting message
2983first, and output it in one fell swoop. This gives a better chance of it
2984ending up as a single packet. */
2985
acec9514 2986ss = string_get(256);
059ec3d9
PH
2987
2988p = s;
2989do /* At least once, in case we have an empty string */
2990 {
2991 int len;
2992 uschar *linebreak = Ustrchr(p, '\n');
acec9514 2993 ss = string_catn(ss, code, 3);
db57e575 2994 if (!linebreak)
059ec3d9
PH
2995 {
2996 len = Ustrlen(p);
acec9514 2997 ss = string_catn(ss, US" ", 1);
059ec3d9
PH
2998 }
2999 else
3000 {
3001 len = linebreak - p;
acec9514 3002 ss = string_catn(ss, US"-", 1);
059ec3d9 3003 }
acec9514
JH
3004 ss = string_catn(ss, esc, esclen);
3005 ss = string_catn(ss, p, len);
3006 ss = string_catn(ss, US"\r\n", 2);
059ec3d9 3007 p += len;
db57e575 3008 if (linebreak) p++;
059ec3d9 3009 }
db57e575 3010while (*p);
059ec3d9 3011
059ec3d9
PH
3012/* Before we write the banner, check that there is no input pending, unless
3013this synchronisation check is disabled. */
3014
81344b40 3015#ifndef DISABLE_PIPE_CONNECT
ee8b8090
JH
3016fl.pipe_connect_acceptable =
3017 sender_host_address && verify_check_host(&pipe_connect_advertise_hosts) == OK;
3018
a14e5636 3019if (!check_sync())
ee8b8090
JH
3020 if (fl.pipe_connect_acceptable)
3021 f.smtp_in_early_pipe_used = TRUE;
3022 else
3023#else
3024if (!check_sync())
3025#endif
3026 {
3027 unsigned n = smtp_inend - smtp_inptr;
3028 if (n > 32) n = 32;
3029
3030 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol "
3031 "synchronization error (input sent without waiting for greeting): "
3032 "rejected connection from %s input=\"%s\"", host_and_ident(TRUE),
3033 string_printing(string_copyn(smtp_inptr, n)));
3034 smtp_printf("554 SMTP synchronization error\r\n", FALSE);
3035 return FALSE;
3036 }
059ec3d9
PH
3037
3038/* Now output the banner */
ee8b8090 3039/*XXX the ehlo-resp code does its own tls/nontls bit. Maybe subroutine that? */
059ec3d9 3040
ee8b8090 3041smtp_printf("%s",
81344b40 3042#ifndef DISABLE_PIPE_CONNECT
ee8b8090
JH
3043 fl.pipe_connect_acceptable && pipeline_connect_sends(),
3044#else
3045 FALSE,
3046#endif
3047 string_from_gstring(ss));
a2673768
JH
3048
3049/* Attempt to see if we sent the banner before the last ACK of the 3-way
3050handshake arrived. If so we must have managed a TFO. */
3051
3052#ifdef TCP_FASTOPEN
3053tfo_in_check();
3054#endif
3055
059ec3d9
PH
3056return TRUE;
3057}
3058
3059
3060
3061
3062
3063/*************************************************
3064* Handle SMTP syntax and protocol errors *
3065*************************************************/
3066
3067/* Write to the log for SMTP syntax errors in incoming commands, if configured
3068to do so. Then transmit the error response. The return value depends on the
3069number of syntax and protocol errors in this SMTP session.
3070
3071Arguments:
3072 type error type, given as a log flag bit
3073 code response code; <= 0 means don't send a response
3074 data data to reflect in the response (can be NULL)
3075 errmess the error message
3076
3077Returns: -1 limit of syntax/protocol errors NOT exceeded
3078 +1 limit of syntax/protocol errors IS exceeded
3079
3080These values fit in with the values of the "done" variable in the main
3081processing loop in smtp_setup_msg(). */
3082
3083static int
3084synprot_error(int type, int code, uschar *data, uschar *errmess)
3085{
3086int yield = -1;
3087
3088log_write(type, LOG_MAIN, "SMTP %s error in \"%s\" %s %s",
3089 (type == L_smtp_syntax_error)? "syntax" : "protocol",
3ee512ff 3090 string_printing(smtp_cmd_buffer), host_and_ident(TRUE), errmess);
059ec3d9
PH
3091
3092if (++synprot_error_count > smtp_max_synprot_errors)
3093 {
3094 yield = 1;
3095 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
3096 "syntax or protocol errors (last command was \"%s\")",
0ebc4d69 3097 host_and_ident(FALSE), string_printing(smtp_cmd_buffer));
059ec3d9
PH
3098 }
3099
3100if (code > 0)
3101 {
925ac8e4
JH
3102 smtp_printf("%d%c%s%s%s\r\n", FALSE, code, yield == 1 ? '-' : ' ',
3103 data ? data : US"", data ? US": " : US"", errmess);
059ec3d9 3104 if (yield == 1)
925ac8e4 3105 smtp_printf("%d Too many syntax or protocol errors\r\n", FALSE, code);
059ec3d9
PH
3106 }
3107
3108return yield;
3109}
3110
3111
3112
3113
3114/*************************************************
059ec3d9
PH
3115* Send SMTP response, possibly multiline *
3116*************************************************/
3117
3118/* There are, it seems, broken clients out there that cannot handle multiline
3119responses. If no_multiline_responses is TRUE (it can be set from an ACL), we
3120output nothing for non-final calls, and only the first line for anything else.
3121
3122Arguments:
a5bd321b 3123 code SMTP code, may involve extended status codes
d6a96edc 3124 codelen length of smtp code; if > 4 there's an ESC
059ec3d9
PH
3125 final FALSE if the last line isn't the final line
3126 msg message text, possibly containing newlines
3127
3128Returns: nothing
3129*/
3130
3131void
a5bd321b 3132smtp_respond(uschar* code, int codelen, BOOL final, uschar *msg)
059ec3d9 3133{
a5bd321b
PH
3134int esclen = 0;
3135uschar *esc = US"";
3136
8768d548 3137if (!final && f.no_multiline_responses) return;
059ec3d9 3138
d6a96edc 3139if (codelen > 4)
a5bd321b
PH
3140 {
3141 esc = code + 4;
3142 esclen = codelen - 4;
3143 }
3144
2679d413
PH
3145/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
3146have had the same. Note: this code is also present in smtp_printf(). It would
3147be tidier to have it only in one place, but when it was added, it was easier to
3148do it that way, so as not to have to mess with the code for the RCPT command,
3149which sometimes uses smtp_printf() and sometimes smtp_respond(). */
3150
88752192 3151if (fl.rcpt_in_progress)
2679d413
PH
3152 {
3153 if (rcpt_smtp_response == NULL)
3154 rcpt_smtp_response = string_copy(msg);
88752192 3155 else if (fl.rcpt_smtp_response_same &&
2679d413 3156 Ustrcmp(rcpt_smtp_response, msg) != 0)
88752192
JH
3157 fl.rcpt_smtp_response_same = FALSE;
3158 fl.rcpt_in_progress = FALSE;
2679d413
PH
3159 }
3160
e5de01f0 3161/* Now output the message, splitting it up into multiple lines if necessary.
925ac8e4
JH
3162We only handle pipelining these responses as far as nonfinal/final groups,
3163not the whole MAIL/RCPT/DATA response set. */
2679d413 3164
059ec3d9
PH
3165for (;;)
3166 {
3167 uschar *nl = Ustrchr(msg, '\n');
3168 if (nl == NULL)
3169 {
925ac8e4 3170 smtp_printf("%.3s%c%.*s%s\r\n", !final, code, final ? ' ':'-', esclen, esc, msg);
059ec3d9
PH
3171 return;
3172 }
8768d548 3173 else if (nl[1] == 0 || f.no_multiline_responses)
059ec3d9 3174 {
925ac8e4 3175 smtp_printf("%.3s%c%.*s%.*s\r\n", !final, code, final ? ' ':'-', esclen, esc,
a5bd321b 3176 (int)(nl - msg), msg);
059ec3d9
PH
3177 return;
3178 }
3179 else
3180 {
925ac8e4 3181 smtp_printf("%.3s-%.*s%.*s\r\n", TRUE, code, esclen, esc, (int)(nl - msg), msg);
059ec3d9
PH
3182 msg = nl + 1;
3183 while (isspace(*msg)) msg++;
3184 }
3185 }
3186}
3187
3188
3189
3190
3191/*************************************************
4e88a19f
PH
3192* Parse user SMTP message *
3193*************************************************/
3194
3195/* This function allows for user messages overriding the response code details
3196by providing a suitable response code string at the start of the message
3197user_msg. Check the message for starting with a response code and optionally an
3198extended status code. If found, check that the first digit is valid, and if so,
3199change the code pointer and length to use the replacement. An invalid code
3200causes a panic log; in this case, if the log messages is the same as the user
3201message, we must also adjust the value of the log message to show the code that
3202is actually going to be used (the original one).
3203
3204This function is global because it is called from receive.c as well as within
3205this module.
3206
d6a96edc
PH
3207Note that the code length returned includes the terminating whitespace
3208character, which is always included in the regex match.
3209
4e88a19f
PH
3210Arguments:
3211 code SMTP code, may involve extended status codes
d6a96edc 3212 codelen length of smtp code; if > 4 there's an ESC
4e88a19f
PH
3213 msg message text
3214 log_msg optional log message, to be adjusted with the new SMTP code
4f6ae5c3 3215 check_valid if true, verify the response code
4e88a19f
PH
3216
3217Returns: nothing
3218*/
3219
3220void
4f6ae5c3
JH
3221smtp_message_code(uschar **code, int *codelen, uschar **msg, uschar **log_msg,
3222 BOOL check_valid)
4e88a19f
PH
3223{
3224int n;
3225int ovector[3];
3226
4f6ae5c3 3227if (!msg || !*msg) return;
4e88a19f 3228
4f6ae5c3
JH
3229if ((n = pcre_exec(regex_smtp_code, NULL, CS *msg, Ustrlen(*msg), 0,
3230 PCRE_EOPT, ovector, sizeof(ovector)/sizeof(int))) < 0) return;
4e88a19f 3231
4f6ae5c3 3232if (check_valid && (*msg)[0] != (*code)[0])
4e88a19f
PH
3233 {
3234 log_write(0, LOG_MAIN|LOG_PANIC, "configured error code starts with "
3235 "incorrect digit (expected %c) in \"%s\"", (*code)[0], *msg);
3236 if (log_msg != NULL && *log_msg == *msg)
3237 *log_msg = string_sprintf("%s %s", *code, *log_msg + ovector[1]);
3238 }
3239else
3240 {
3241 *code = *msg;
3242 *codelen = ovector[1]; /* Includes final space */
3243 }
3244*msg += ovector[1]; /* Chop the code off the message */
3245return;
3246}
3247
3248
3249
3250
3251/*************************************************
059ec3d9
PH
3252* Handle an ACL failure *
3253*************************************************/
3254
3255/* This function is called when acl_check() fails. As well as calls from within
3256this module, it is called from receive.c for an ACL after DATA. It sorts out
5b6f7658 3257logging the incident, and sends the error response. A message containing
059ec3d9
PH
3258newlines is turned into a multiline SMTP response, but for logging, only the
3259first line is used.
3260
a5bd321b
PH
3261There's a table of default permanent failure response codes to use in
3262globals.c, along with the table of names. VFRY is special. Despite RFC1123 it
3263defaults disabled in Exim. However, discussion in connection with RFC 821bis
3264(aka RFC 2821) has concluded that the response should be 252 in the disabled
3265state, because there are broken clients that try VRFY before RCPT. A 5xx
3266response should be given only when the address is positively known to be
4f6ae5c3
JH
3267undeliverable. Sigh. We return 252 if there is no VRFY ACL or it provides
3268no explicit code, but if there is one we let it know best.
3269Also, for ETRN, 458 is given on refusal, and for AUTH, 503.
a5bd321b
PH
3270
3271From Exim 4.63, it is possible to override the response code details by
3272providing a suitable response code string at the start of the message provided
3273in user_msg. The code's first digit is checked for validity.
059ec3d9
PH
3274
3275Arguments:
4f6ae5c3
JH
3276 where where the ACL was called from
3277 rc the failure code
3278 user_msg a message that can be included in an SMTP response
3279 log_msg a message for logging
059ec3d9
PH
3280
3281Returns: 0 in most cases
3282 2 if the failure code was FAIL_DROP, in which case the
3283 SMTP connection should be dropped (this value fits with the
3284 "done" variable in smtp_setup_msg() below)
3285*/
3286
3287int
3288smtp_handle_acl_fail(int where, int rc, uschar *user_msg, uschar *log_msg)
3289{
059ec3d9 3290BOOL drop = rc == FAIL_DROP;
a5bd321b 3291int codelen = 3;
a5bd321b 3292uschar *smtp_code;
059ec3d9
PH
3293uschar *lognl;
3294uschar *sender_info = US"";
64ffc24f 3295uschar *what =
8523533c 3296#ifdef WITH_CONTENT_SCAN
3cc3f762 3297 where == ACL_WHERE_MIME ? US"during MIME ACL checks" :
8e669ac1 3298#endif
3cc3f762
JH
3299 where == ACL_WHERE_PREDATA ? US"DATA" :
3300 where == ACL_WHERE_DATA ? US"after DATA" :
8ccd00b1 3301#ifndef DISABLE_PRDR
3cc3f762 3302 where == ACL_WHERE_PRDR ? US"after DATA PRDR" :
fd98a5c6 3303#endif
3cc3f762
JH
3304 smtp_cmd_data ?
3305 string_sprintf("%s %s", acl_wherenames[where], smtp_cmd_data) :
3306 string_sprintf("%s in \"connect\" ACL", acl_wherenames[where]);
059ec3d9
PH
3307
3308if (drop) rc = FAIL;
3309
4e88a19f 3310/* Set the default SMTP code, and allow a user message to change it. */
a5bd321b 3311
4f6ae5c3
JH
3312smtp_code = rc == FAIL ? acl_wherecodes[where] : US"451";
3313smtp_message_code(&smtp_code, &codelen, &user_msg, &log_msg,
3314 where != ACL_WHERE_VRFY);
a5bd321b 3315
059ec3d9
PH
3316/* We used to have sender_address here; however, there was a bug that was not
3317updating sender_address after a rewrite during a verify. When this bug was
3318fixed, sender_address at this point became the rewritten address. I'm not sure
3319this is what should be logged, so I've changed to logging the unrewritten
3320address to retain backward compatibility. */
3321
8523533c 3322#ifndef WITH_CONTENT_SCAN
059ec3d9 3323if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA)
8523533c
TK
3324#else
3325if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA || where == ACL_WHERE_MIME)
3326#endif
059ec3d9 3327 {
b98bb9ac
PP
3328 sender_info = string_sprintf("F=<%s>%s%s%s%s ",
3329 sender_address_unrewritten ? sender_address_unrewritten : sender_address,
3330 sender_host_authenticated ? US" A=" : US"",
3331 sender_host_authenticated ? sender_host_authenticated : US"",
3332 sender_host_authenticated && authenticated_id ? US":" : US"",
3333 sender_host_authenticated && authenticated_id ? authenticated_id : US""
3334 );
059ec3d9
PH
3335 }
3336
3337/* If there's been a sender verification failure with a specific message, and
3338we have not sent a response about it yet, do so now, as a preliminary line for
278c6e6c
PH
3339failures, but not defers. However, always log it for defer, and log it for fail
3340unless the sender_verify_fail log selector has been turned off. */
059ec3d9 3341
02b41d71 3342if (sender_verified_failed &&
059ec3d9
PH
3343 !testflag(sender_verified_failed, af_sverify_told))
3344 {
88752192
JH
3345 BOOL save_rcpt_in_progress = fl.rcpt_in_progress;
3346 fl.rcpt_in_progress = FALSE; /* So as not to treat these as the error */
2679d413 3347
059ec3d9
PH
3348 setflag(sender_verified_failed, af_sverify_told);
3349
6c6d6e48 3350 if (rc != FAIL || LOGGING(sender_verify_fail))
278c6e6c
PH
3351 log_write(0, LOG_MAIN|LOG_REJECT, "%s sender verify %s for <%s>%s",
3352 host_and_ident(TRUE),
3353 ((sender_verified_failed->special_action & 255) == DEFER)? "defer":"fail",
3354 sender_verified_failed->address,
3355 (sender_verified_failed->message == NULL)? US"" :
3356 string_sprintf(": %s", sender_verified_failed->message));
059ec3d9 3357
02b41d71 3358 if (rc == FAIL && sender_verified_failed->user_message)
a5bd321b 3359 smtp_respond(smtp_code, codelen, FALSE, string_sprintf(
059ec3d9
PH
3360 testflag(sender_verified_failed, af_verify_pmfail)?
3361 "Postmaster verification failed while checking <%s>\n%s\n"
3362 "Several RFCs state that you are required to have a postmaster\n"
3363 "mailbox for each mail domain. This host does not accept mail\n"
3364 "from domains whose servers reject the postmaster address."
3365 :
3366 testflag(sender_verified_failed, af_verify_nsfail)?
3367 "Callback setup failed while verifying <%s>\n%s\n"
3368 "The initial connection, or a HELO or MAIL FROM:<> command was\n"
3369 "rejected. Refusing MAIL FROM:<> does not help fight spam, disregards\n"
3370 "RFC requirements, and stops you from receiving standard bounce\n"
3371 "messages. This host does not accept mail from domains whose servers\n"
3372 "refuse bounces."
3373 :
3374 "Verification failed for <%s>\n%s",
3375 sender_verified_failed->address,
3376 sender_verified_failed->user_message));
2679d413 3377
88752192 3378 fl.rcpt_in_progress = save_rcpt_in_progress;
059ec3d9
PH
3379 }
3380
3381/* Sort out text for logging */
3382
3cc3f762
JH
3383log_msg = log_msg ? string_sprintf(": %s", log_msg) : US"";
3384if ((lognl = Ustrchr(log_msg, '\n'))) *lognl = 0;
059ec3d9
PH
3385
3386/* Send permanent failure response to the command, but the code used isn't
3387always a 5xx one - see comments at the start of this function. If the original
3388rc was FAIL_DROP we drop the connection and yield 2. */
3389
ff5929e3
JH
3390if (rc == FAIL)
3391 smtp_respond(smtp_code, codelen, TRUE,
3392 user_msg ? user_msg : US"Administrative prohibition");
059ec3d9
PH
3393
3394/* Send temporary failure response to the command. Don't give any details,
3395unless acl_temp_details is set. This is TRUE for a callout defer, a "defer"
3396verb, and for a header verify when smtp_return_error_details is set.
3397
3398This conditional logic is all somewhat of a mess because of the odd
3399interactions between temp_details and return_error_details. One day it should
3400be re-implemented in a tidier fashion. */
3401
3402else
8768d548 3403 if (f.acl_temp_details && user_msg)
059ec3d9 3404 {
ff5929e3
JH
3405 if ( smtp_return_error_details
3406 && sender_verified_failed
3407 && sender_verified_failed->message
3408 )
a5bd321b 3409 smtp_respond(smtp_code, codelen, FALSE, sender_verified_failed->message);
ff5929e3 3410
a5bd321b 3411 smtp_respond(smtp_code, codelen, TRUE, user_msg);
059ec3d9
PH
3412 }
3413 else
a5bd321b
PH
3414 smtp_respond(smtp_code, codelen, TRUE,
3415 US"Temporary local problem - please try later");
059ec3d9 3416
6ea85e9a
PH
3417/* Log the incident to the logs that are specified by log_reject_target
3418(default main, reject). This can be empty to suppress logging of rejections. If
3419the connection is not forcibly to be dropped, return 0. Otherwise, log why it
3420is closing if required and return 2. */
059ec3d9 3421
6ea85e9a 3422if (log_reject_target != 0)
887291d2 3423 {
01603eec 3424#ifndef DISABLE_TLS
acec9514
JH
3425 gstring * g = s_tlslog(NULL);
3426 uschar * tls = string_from_gstring(g);
fc16abb4 3427 if (!tls) tls = US"";
e45a1c37 3428#else
fc16abb4 3429 uschar * tls = US"";
e45a1c37 3430#endif
3cc3f762
JH
3431 log_write(where == ACL_WHERE_CONNECT ? L_connection_reject : 0,
3432 log_reject_target, "%s%s%s %s%srejected %s%s",
fc16abb4
JH
3433 LOGGING(dnssec) && sender_host_dnssec ? US" DS" : US"",
3434 host_and_ident(TRUE),
3435 tls,
3436 sender_info,
3437 rc == FAIL ? US"" : US"temporarily ",
3438 what, log_msg);
887291d2 3439 }
059ec3d9
PH
3440
3441if (!drop) return 0;
3442
3443log_write(L_smtp_connection, LOG_MAIN, "%s closed by DROP in ACL",
3444 smtp_get_connection_info());
8f128379
PH
3445
3446/* Run the not-quit ACL, but without any custom messages. This should not be a
3447problem, because we get here only if some other ACL has issued "drop", and
3448in that case, *its* custom messages will have been used above. */
3449
3450smtp_notquit_exit(US"acl-drop", NULL, NULL);
059ec3d9
PH
3451return 2;
3452}
3453
3454
3455
3456
3457/*************************************************
8f128379
PH
3458* Handle SMTP exit when QUIT is not given *
3459*************************************************/
3460
3461/* This function provides a logging/statistics hook for when an SMTP connection
3462is dropped on the floor or the other end goes away. It's a global function
3463because it's called from receive.c as well as this module. As well as running
3464the NOTQUIT ACL, if there is one, this function also outputs a final SMTP
3465response, either with a custom message from the ACL, or using a default. There
3466is one case, however, when no message is output - after "drop". In that case,
3467the ACL that obeyed "drop" has already supplied the custom message, and NULL is
3468passed to this function.
3469
3470In case things go wrong while processing this function, causing an error that
4c04137d 3471may re-enter this function, there is a recursion check.
8f128379
PH
3472
3473Arguments:
3474 reason What $smtp_notquit_reason will be set to in the ACL;
3475 if NULL, the ACL is not run
3476 code The error code to return as part of the response
3477 defaultrespond The default message if there's no user_msg