Use single-bit fields for file-global flags in smtp_in
[exim.git] / src / src / smtp_in.c
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1/*************************************************
2* Exim - an Internet mail transport agent *
3*************************************************/
4
f9ba5e22 5/* Copyright (c) University of Cambridge 1995 - 2018 */
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6/* See the file NOTICE for conditions of use and distribution. */
7
8/* Functions for handling an incoming SMTP call. */
9
10
11#include "exim.h"
2ef7ed08 12#include <assert.h>
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13
14
15/* Initialize for TCP wrappers if so configured. It appears that the macro
16HAVE_IPV6 is used in some versions of the tcpd.h header, so we unset it before
17including that header, and restore its value afterwards. */
18
19#ifdef USE_TCP_WRAPPERS
20
21 #if HAVE_IPV6
22 #define EXIM_HAVE_IPV6
23 #endif
24 #undef HAVE_IPV6
25 #include <tcpd.h>
26 #undef HAVE_IPV6
27 #ifdef EXIM_HAVE_IPV6
28 #define HAVE_IPV6 TRUE
29 #endif
30
31int allow_severity = LOG_INFO;
32int deny_severity = LOG_NOTICE;
5dc43717 33uschar *tcp_wrappers_name;
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34#endif
35
36
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37/* Size of buffer for reading SMTP commands. We used to use 512, as defined
38by RFC 821. However, RFC 1869 specifies that this must be increased for SMTP
39commands that accept arguments, and this in particular applies to AUTH, where
94431adb 40the data can be quite long. More recently this value was 2048 in Exim;
e2ca7082 41however, RFC 4954 (circa 2007) recommends 12288 bytes to handle AUTH. Clients
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42such as Thunderbird will send an AUTH with an initial-response for GSSAPI.
43The maximum size of a Kerberos ticket under Windows 2003 is 12000 bytes, and
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44we need room to handle large base64-encoded AUTHs for GSSAPI.
45*/
46
bd8fbe36 47#define SMTP_CMD_BUFFER_SIZE 16384
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48
49/* Size of buffer for reading SMTP incoming packets */
50
bd8fbe36 51#define IN_BUFFER_SIZE 8192
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52
53/* Structure for SMTP command list */
54
55typedef struct {
1ba28e2b 56 const char *name;
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57 int len;
58 short int cmd;
59 short int has_arg;
60 short int is_mail_cmd;
61} smtp_cmd_list;
62
63/* Codes for identifying commands. We order them so that those that come first
64are those for which synchronization is always required. Checking this can help
65block some spam. */
66
67enum {
68 /* These commands are required to be synchronized, i.e. to be the last in a
69 block of commands when pipelining. */
70
71 HELO_CMD, EHLO_CMD, DATA_CMD, /* These are listed in the pipelining */
72 VRFY_CMD, EXPN_CMD, NOOP_CMD, /* RFC as requiring synchronization */
73 ETRN_CMD, /* This by analogy with TURN from the RFC */
74 STARTTLS_CMD, /* Required by the STARTTLS RFC */
b3ef41c9 75 TLS_AUTH_CMD, /* auto-command at start of SSL */
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76
77 /* This is a dummy to identify the non-sync commands when pipelining */
78
79 NON_SYNC_CMD_PIPELINING,
80
81 /* These commands need not be synchronized when pipelining */
82
83 MAIL_CMD, RCPT_CMD, RSET_CMD,
84
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85 /* This is a dummy to identify the non-sync commands when not pipelining */
86
87 NON_SYNC_CMD_NON_PIPELINING,
88
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89 /* RFC3030 section 2: "After all MAIL and RCPT responses are collected and
90 processed the message is sent using a series of BDAT commands"
91 implies that BDAT should be synchronized. However, we see Google, at least,
92 sending MAIL,RCPT,BDAT-LAST in a single packet, clearly not waiting for
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93 processing of the RCPT response(s). We shall do the same, and not require
94 synch for BDAT. Worse, as the chunk may (very likely will) follow the
95 command-header in the same packet we cannot do the usual "is there any
4c04137d 96 follow-on data after the command line" even for non-pipeline mode.
f4630439 97 So we'll need an explicit check after reading the expected chunk amount
4c04137d 98 when non-pipe, before sending the ACK. */
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99
100 BDAT_CMD,
101
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102 /* I have been unable to find a statement about the use of pipelining
103 with AUTH, so to be on the safe side it is here, though I kind of feel
104 it should be up there with the synchronized commands. */
105
106 AUTH_CMD,
107
108 /* I'm not sure about these, but I don't think they matter. */
109
110 QUIT_CMD, HELP_CMD,
111
cee5f132 112#ifdef SUPPORT_PROXY
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113 PROXY_FAIL_IGNORE_CMD,
114#endif
115
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116 /* These are specials that don't correspond to actual commands */
117
118 EOF_CMD, OTHER_CMD, BADARG_CMD, BADCHAR_CMD, BADSYN_CMD,
119 TOO_MANY_NONMAIL_CMD };
120
121
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122/* This is a convenience macro for adding the identity of an SMTP command
123to the circular buffer that holds a list of the last n received. */
124
125#define HAD(n) \
126 smtp_connection_had[smtp_ch_index++] = n; \
127 if (smtp_ch_index >= SMTP_HBUFF_SIZE) smtp_ch_index = 0
128
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129
130/*************************************************
131* Local static variables *
132*************************************************/
133
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134static struct {
135 BOOL auth_advertised :1;
059ec3d9 136#ifdef SUPPORT_TLS
88752192 137 BOOL tls_advertised :1;
8ac90765 138# ifdef EXPERIMENTAL_REQUIRETLS
88752192 139 BOOL requiretls_advertised :1;
8ac90765 140# endif
059ec3d9 141#endif
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142 BOOL dsn_advertised :1;
143 BOOL esmtp :1;
144 BOOL helo_required :1;
145 BOOL helo_verify :1;
146 BOOL helo_seen :1;
147 BOOL helo_accept_junk :1;
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
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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;
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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;
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169static uschar *smtp_data_buffer;
170static uschar *smtp_cmd_data;
171
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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
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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. */
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189
190static smtp_cmd_list cmd_list[] = {
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191 /* name len cmd has_arg is_mail_cmd */
192
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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 },
e0574cb5 197#ifdef SUPPORT_TLS
059ec3d9 198 { "starttls", sizeof("starttls")-1, STARTTLS_CMD, FALSE, FALSE },
69d8eed7 199 { "tls_auth", 0, TLS_AUTH_CMD, FALSE, FALSE },
e0574cb5 200#endif
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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 },
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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
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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 {
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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[] = {
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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 };
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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 };
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251
252#define pnormal 0
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253#define pextend 2
254#define pcrpted 1 /* added to pextend or pnormal */
255#define pauthed 2 /* added to pextend */
059ec3d9 256
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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
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262 ENV_MAIL_OPT_PRDR,
263#endif
6c1c3d1d 264 ENV_MAIL_OPT_RET, ENV_MAIL_OPT_ENVID,
8c5d388a 265#ifdef SUPPORT_I18N
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266 ENV_MAIL_OPT_UTF8,
267#endif
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268#ifdef EXPERIMENTAL_REQUIRETLS
269 ENV_MAIL_OPT_REQTLS,
270#endif
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271 };
272typedef struct {
273 uschar * name; /* option requested during MAIL cmd */
274 int value; /* enum type */
275 BOOL need_value; /* TRUE requires value (name=value pair format)
276 FALSE is a singleton */
277 } env_mail_type_t;
278static env_mail_type_t env_mail_type_list[] = {
279 { US"SIZE", ENV_MAIL_OPT_SIZE, TRUE },
280 { US"BODY", ENV_MAIL_OPT_BODY, TRUE },
281 { US"AUTH", ENV_MAIL_OPT_AUTH, TRUE },
8ccd00b1 282#ifndef DISABLE_PRDR
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283 { US"PRDR", ENV_MAIL_OPT_PRDR, FALSE },
284#endif
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285 { US"RET", ENV_MAIL_OPT_RET, TRUE },
286 { US"ENVID", ENV_MAIL_OPT_ENVID, TRUE },
8c5d388a 287#ifdef SUPPORT_I18N
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288 { US"SMTPUTF8",ENV_MAIL_OPT_UTF8, FALSE }, /* rfc6531 */
289#endif
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290#ifdef EXPERIMENTAL_REQUIRETLS
291 /* https://tools.ietf.org/html/draft-ietf-uta-smtp-require-tls-03 */
292 { US"REQUIRETLS",ENV_MAIL_OPT_REQTLS, FALSE },
293#endif
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294 /* keep this the last entry */
295 { US"NULL", ENV_MAIL_OPT_NULL, FALSE },
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296 };
297
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298/* When reading SMTP from a remote host, we have to use our own versions of the
299C input-reading functions, in order to be able to flush the SMTP output only
300when about to read more data from the socket. This is the only way to get
301optimal performance when the client is using pipelining. Flushing for every
302command causes a separate packet and reply packet each time; saving all the
303responses up (when pipelining) combines them into one packet and one response.
304
305For simplicity, these functions are used for *all* SMTP input, not only when
306receiving over a socket. However, after setting up a secure socket (SSL), input
307is read via the OpenSSL library, and another set of functions is used instead
308(see tls.c).
309
310These functions are set in the receive_getc etc. variables and called with the
311same interface as the C functions. However, since there can only ever be
312one incoming SMTP call, we just use a single buffer and flags. There is no need
313to implement a complicated private FILE-like structure.*/
314
315static uschar *smtp_inbuffer;
316static uschar *smtp_inptr;
317static uschar *smtp_inend;
318static int smtp_had_eof;
319static int smtp_had_error;
320
321
7e3ce68e 322/* forward declarations */
bd8fbe36 323static int smtp_read_command(BOOL check_sync, unsigned buffer_lim);
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324static int synprot_error(int type, int code, uschar *data, uschar *errmess);
325static void smtp_quit_handler(uschar **, uschar **);
326static void smtp_rset_handler(void);
327
059ec3d9 328/*************************************************
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329* Recheck synchronization *
330*************************************************/
331
332/* Synchronization checks can never be perfect because a packet may be on its
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333way but not arrived when the check is done. Normally, the checks happen when
334commands are read: Exim ensures that there is no more input in the input buffer.
335In normal cases, the response to the command will be fast, and there is no
336further check.
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337
338However, for some commands an ACL is run, and that can include delays. In those
339cases, it is useful to do another check on the input just before sending the
340response. This also applies at the start of a connection. This function does
341that check by means of the select() function, as long as the facility is not
342disabled or inappropriate. A failure of select() is ignored.
343
344When there is unwanted input, we read it so that it appears in the log of the
345error.
346
347Arguments: none
348Returns: TRUE if all is well; FALSE if there is input pending
349*/
350
351static BOOL
925ac8e4 352wouldblock_reading(void)
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353{
354int fd, rc;
355fd_set fds;
356struct timeval tzero;
357
9067f574 358#ifdef SUPPORT_TLS
74f1a423 359if (tls_in.active.sock >= 0)
e5de01f0 360 return !tls_could_read();
9067f574 361#endif
f4630439 362
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363if (smtp_inptr < smtp_inend)
364 return FALSE;
365
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366fd = fileno(smtp_in);
367FD_ZERO(&fds);
368FD_SET(fd, &fds);
369tzero.tv_sec = 0;
370tzero.tv_usec = 0;
371rc = select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &tzero);
372
373if (rc <= 0) return TRUE; /* Not ready to read */
bd8fbe36 374rc = smtp_getc(GETC_BUFFER_UNLIMITED);
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375if (rc < 0) return TRUE; /* End of file or error */
376
377smtp_ungetc(rc);
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378return FALSE;
379}
380
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381static BOOL
382check_sync(void)
383{
8768d548 384if (!smtp_enforce_sync || !sender_host_address || f.sender_host_notsocket)
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385 return TRUE;
386
387return wouldblock_reading();
388}
389
390
391/* If there's input waiting (and we're doing pipelineing) then we can pipeline
392a reponse with the one following. */
393
394static BOOL
395pipeline_response(void)
396{
397if ( !smtp_enforce_sync || !sender_host_address
8768d548 398 || f.sender_host_notsocket || !f.smtp_in_pipelining_advertised)
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399 return FALSE;
400
3fc73bdc 401if (wouldblock_reading()) return FALSE;
8768d548 402f.smtp_in_pipelining_used = TRUE;
3fc73bdc 403return TRUE;
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404}
405
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406
407
408/*************************************************
409* Log incomplete transactions *
410*************************************************/
411
412/* This function is called after a transaction has been aborted by RSET, QUIT,
413connection drops or other errors. It logs the envelope information received
414so far in order to preserve address verification attempts.
415
416Argument: string to indicate what aborted the transaction
417Returns: nothing
418*/
419
420static void
421incomplete_transaction_log(uschar *what)
422{
423if (sender_address == NULL || /* No transaction in progress */
424 !LOGGING(smtp_incomplete_transaction))
425 return;
426
427/* Build list of recipients for logging */
428
429if (recipients_count > 0)
430 {
431 int i;
432 raw_recipients = store_get(recipients_count * sizeof(uschar *));
433 for (i = 0; i < recipients_count; i++)
434 raw_recipients[i] = recipients_list[i].address;
435 raw_recipients_count = recipients_count;
436 }
437
438log_write(L_smtp_incomplete_transaction, LOG_MAIN|LOG_SENDER|LOG_RECIPIENTS,
439 "%s incomplete transaction (%s)", host_and_ident(TRUE), what);
440}
441
442
443
444
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445void
446smtp_command_timeout_exit(void)
447{
448log_write(L_lost_incoming_connection,
449 LOG_MAIN, "SMTP command timeout on%s connection from %s",
74f1a423 450 tls_in.active.sock >= 0 ? " TLS" : "", host_and_ident(FALSE));
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451if (smtp_batched_input)
452 moan_smtp_batch(NULL, "421 SMTP command timeout"); /* Does not return */
453smtp_notquit_exit(US"command-timeout", US"421",
454 US"%s: SMTP command timeout - closing connection",
455 smtp_active_hostname);
456exim_exit(EXIT_FAILURE, US"receiving");
457}
458
459void
460smtp_command_sigterm_exit(void)
461{
462log_write(0, LOG_MAIN, "%s closed after SIGTERM", smtp_get_connection_info());
463if (smtp_batched_input)
464 moan_smtp_batch(NULL, "421 SIGTERM received"); /* Does not return */
465smtp_notquit_exit(US"signal-exit", US"421",
466 US"%s: Service not available - closing connection", smtp_active_hostname);
467exim_exit(EXIT_FAILURE, US"receiving");
468}
469
470void
471smtp_data_timeout_exit(void)
472{
473log_write(L_lost_incoming_connection,
474 LOG_MAIN, "SMTP data timeout (message abandoned) on connection from %s F=<%s>",
475 sender_fullhost ? sender_fullhost : US"local process", sender_address);
476receive_bomb_out(US"data-timeout", US"SMTP incoming data timeout");
477/* Does not return */
478}
479
480void
481smtp_data_sigint_exit(void)
482{
483log_write(0, LOG_MAIN, "%s closed after %s",
484 smtp_get_connection_info(), had_data_sigint == SIGTERM ? "SIGTERM":"SIGINT");
485receive_bomb_out(US"signal-exit",
486 US"Service not available - SIGTERM or SIGINT received");
487/* Does not return */
488}
489
490
491
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492/* Refill the buffer, and notify DKIM verification code.
493Return false for error or EOF.
494*/
495
496static BOOL
497smtp_refill(unsigned lim)
498{
499int rc, save_errno;
500if (!smtp_out) return FALSE;
501fflush(smtp_out);
502if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
503
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504/* Limit amount read, so non-message data is not fed to DKIM.
505Take care to not touch the safety NUL at the end of the buffer. */
0d81dabc 506
ecce6d9a 507rc = read(fileno(smtp_in), smtp_inbuffer, MIN(IN_BUFFER_SIZE-1, lim));
0d81dabc 508save_errno = errno;
9723f966 509if (smtp_receive_timeout > 0) alarm(0);
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510if (rc <= 0)
511 {
512 /* Must put the error text in fixed store, because this might be during
513 header reading, where it releases unused store above the header. */
514 if (rc < 0)
515 {
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516 if (had_command_timeout) /* set by signal handler */
517 smtp_command_timeout_exit(); /* does not return */
518 if (had_command_sigterm)
519 smtp_command_sigterm_exit();
520 if (had_data_timeout)
521 smtp_data_timeout_exit();
522 if (had_data_sigint)
523 smtp_data_sigint_exit();
524
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525 smtp_had_error = save_errno;
526 smtp_read_error = string_copy_malloc(
527 string_sprintf(" (error: %s)", strerror(save_errno)));
528 }
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529 else
530 smtp_had_eof = 1;
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531 return FALSE;
532 }
533#ifndef DISABLE_DKIM
534dkim_exim_verify_feed(smtp_inbuffer, rc);
535#endif
536smtp_inend = smtp_inbuffer + rc;
537smtp_inptr = smtp_inbuffer;
538return TRUE;
539}
540
f4630439 541/*************************************************
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542* SMTP version of getc() *
543*************************************************/
544
545/* This gets the next byte from the SMTP input buffer. If the buffer is empty,
546it flushes the output, and refills the buffer, with a timeout. The signal
547handler is set appropriately by the calling function. This function is not used
4c04137d 548after a connection has negotiated itself into an TLS/SSL state.
059ec3d9 549
bd8fbe36 550Arguments: lim Maximum amount to read/buffer
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551Returns: the next character or EOF
552*/
553
554int
bd8fbe36 555smtp_getc(unsigned lim)
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556{
557if (smtp_inptr >= smtp_inend)
0d81dabc 558 if (!smtp_refill(lim))
059ec3d9 559 return EOF;
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560return *smtp_inptr++;
561}
562
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563uschar *
564smtp_getbuf(unsigned * len)
565{
566unsigned size;
567uschar * buf;
568
569if (smtp_inptr >= smtp_inend)
570 if (!smtp_refill(*len))
571 { *len = 0; return NULL; }
572
573if ((size = smtp_inend - smtp_inptr) > *len) size = *len;
574buf = smtp_inptr;
575smtp_inptr += size;
576*len = size;
577return buf;
578}
579
584e96c6
JH
580void
581smtp_get_cache(void)
582{
9960d1e5 583#ifndef DISABLE_DKIM
584e96c6
JH
584int n = smtp_inend - smtp_inptr;
585if (n > 0)
586 dkim_exim_verify_feed(smtp_inptr, n);
584e96c6 587#endif
9960d1e5 588}
059ec3d9
PH
589
590
7e3ce68e
JH
591/* Get a byte from the smtp input, in CHUNKING mode. Handle ack of the
592previous BDAT chunk and getting new ones when we run out. Uses the
593underlying smtp_getc or tls_getc both for that and for getting the
594(buffered) data byte. EOD signals (an expected) no further data.
595ERR signals a protocol error, and EOF a closed input stream.
596
597Called from read_bdat_smtp() in receive.c for the message body, but also
598by the headers read loop in receive_msg(); manipulates chunking_state
599to handle the BDAT command/response.
600Placed here due to the correlation with the above smtp_getc(), which it wraps,
601and also by the need to do smtp command/response handling.
602
bd8fbe36 603Arguments: lim (ignored)
7e3ce68e
JH
604Returns: the next character or ERR, EOD or EOF
605*/
606
607int
bd8fbe36 608bdat_getc(unsigned lim)
7e3ce68e
JH
609{
610uschar * user_msg = NULL;
611uschar * log_msg;
612
613for(;;)
614 {
79de4f37 615#ifndef DISABLE_DKIM
64b67b65 616 unsigned dkim_save;
79de4f37
JH
617#endif
618
bd8fbe36
JH
619 if (chunking_data_left > 0)
620 return lwr_receive_getc(chunking_data_left--);
7e3ce68e
JH
621
622 receive_getc = lwr_receive_getc;
0d81dabc 623 receive_getbuf = lwr_receive_getbuf;
7e3ce68e 624 receive_ungetc = lwr_receive_ungetc;
bd8fbe36 625#ifndef DISABLE_DKIM
79de4f37 626 dkim_save = dkim_collect_input;
64b67b65 627 dkim_collect_input = 0;
bd8fbe36 628#endif
7e3ce68e 629
f4630439
JH
630 /* Unless PIPELINING was offered, there should be no next command
631 until after we ack that chunk */
632
8768d548 633 if (!f.smtp_in_pipelining_advertised && !check_sync())
f4630439 634 {
40525d07
JH
635 unsigned n = smtp_inend - smtp_inptr;
636 if (n > 32) n = 32;
637
f4630439
JH
638 incomplete_transaction_log(US"sync failure");
639 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol synchronization error "
640 "(next input sent too soon: pipelining was not advertised): "
9e0ed81f 641 "rejected \"%s\" %s next input=\"%s\"%s",
f4630439 642 smtp_cmd_buffer, host_and_ident(TRUE),
9e0ed81f
JH
643 string_printing(string_copyn(smtp_inptr, n)),
644 smtp_inend - smtp_inptr > n ? "..." : "");
645 (void) synprot_error(L_smtp_protocol_error, 554, NULL,
646 US"SMTP synchronization error");
f4630439
JH
647 goto repeat_until_rset;
648 }
649
7e3ce68e
JH
650 /* If not the last, ack the received chunk. The last response is delayed
651 until after the data ACL decides on it */
7e3ce68e
JH
652
653 if (chunking_state == CHUNKING_LAST)
584e96c6
JH
654 {
655#ifndef DISABLE_DKIM
e983e85a 656 dkim_exim_verify_feed(NULL, 0); /* notify EOD */
584e96c6 657#endif
7e3ce68e 658 return EOD;
584e96c6 659 }
7e3ce68e 660
925ac8e4 661 smtp_printf("250 %u byte chunk received\r\n", FALSE, chunking_datasize);
bd8fbe36
JH
662 chunking_state = CHUNKING_OFFERED;
663 DEBUG(D_receive) debug_printf("chunking state %d\n", (int)chunking_state);
7e3ce68e
JH
664
665 /* Expect another BDAT cmd from input. RFC 3030 says nothing about
666 QUIT, RSET or NOOP but handling them seems obvious */
667
668next_cmd:
bd8fbe36 669 switch(smtp_read_command(TRUE, 1))
7e3ce68e
JH
670 {
671 default:
672 (void) synprot_error(L_smtp_protocol_error, 503, NULL,
673 US"only BDAT permissible after non-LAST BDAT");
674
675 repeat_until_rset:
bd8fbe36 676 switch(smtp_read_command(TRUE, 1))
7e3ce68e
JH
677 {
678 case QUIT_CMD: smtp_quit_handler(&user_msg, &log_msg); /*FALLTHROUGH */
679 case EOF_CMD: return EOF;
680 case RSET_CMD: smtp_rset_handler(); return ERR;
681 default: if (synprot_error(L_smtp_protocol_error, 503, NULL,
682 US"only RSET accepted now") > 0)
683 return EOF;
684 goto repeat_until_rset;
685 }
686
687 case QUIT_CMD:
688 smtp_quit_handler(&user_msg, &log_msg);
689 /*FALLTHROUGH*/
690 case EOF_CMD:
691 return EOF;
692
693 case RSET_CMD:
694 smtp_rset_handler();
695 return ERR;
696
697 case NOOP_CMD:
698 HAD(SCH_NOOP);
925ac8e4 699 smtp_printf("250 OK\r\n", FALSE);
7e3ce68e
JH
700 goto next_cmd;
701
702 case BDAT_CMD:
703 {
704 int n;
705
706 if (sscanf(CS smtp_cmd_data, "%u %n", &chunking_datasize, &n) < 1)
707 {
708 (void) synprot_error(L_smtp_protocol_error, 501, NULL,
709 US"missing size for BDAT command");
710 return ERR;
711 }
712 chunking_state = strcmpic(smtp_cmd_data+n, US"LAST") == 0
713 ? CHUNKING_LAST : CHUNKING_ACTIVE;
714 chunking_data_left = chunking_datasize;
bd8fbe36
JH
715 DEBUG(D_receive) debug_printf("chunking state %d, %d bytes\n",
716 (int)chunking_state, chunking_data_left);
7e3ce68e
JH
717
718 if (chunking_datasize == 0)
719 if (chunking_state == CHUNKING_LAST)
720 return EOD;
721 else
722 {
723 (void) synprot_error(L_smtp_protocol_error, 504, NULL,
724 US"zero size for BDAT command");
725 goto repeat_until_rset;
726 }
727
728 receive_getc = bdat_getc;
8b77d27a 729 receive_getbuf = bdat_getbuf; /* r~getbuf is never actually used */
7e3ce68e 730 receive_ungetc = bdat_ungetc;
bd8fbe36 731#ifndef DISABLE_DKIM
79de4f37 732 dkim_collect_input = dkim_save;
bd8fbe36 733#endif
7e3ce68e
JH
734 break; /* to top of main loop */
735 }
736 }
737 }
738}
739
0d81dabc
JH
740uschar *
741bdat_getbuf(unsigned * len)
742{
743uschar * buf;
744
745if (chunking_data_left <= 0)
746 { *len = 0; return NULL; }
747
748if (*len > chunking_data_left) *len = chunking_data_left;
749buf = lwr_receive_getbuf(len); /* Either smtp_getbuf or tls_getbuf */
750chunking_data_left -= *len;
751return buf;
752}
753
1ebe15c3 754void
45bd315d
JH
755bdat_flush_data(void)
756{
e99a3a6c 757while (chunking_data_left)
db57e575 758 {
e99a3a6c 759 unsigned n = chunking_data_left;
8b77d27a 760 if (!bdat_getbuf(&n)) break;
db57e575 761 }
45bd315d
JH
762
763receive_getc = lwr_receive_getc;
0d81dabc 764receive_getbuf = lwr_receive_getbuf;
45bd315d
JH
765receive_ungetc = lwr_receive_ungetc;
766
767if (chunking_state != CHUNKING_LAST)
bd8fbe36 768 {
45bd315d 769 chunking_state = CHUNKING_OFFERED;
bd8fbe36
JH
770 DEBUG(D_receive) debug_printf("chunking state %d\n", (int)chunking_state);
771 }
45bd315d
JH
772}
773
7e3ce68e
JH
774
775
776
059ec3d9
PH
777/*************************************************
778* SMTP version of ungetc() *
779*************************************************/
780
781/* Puts a character back in the input buffer. Only ever
782called once.
783
784Arguments:
785 ch the character
786
787Returns: the character
788*/
789
790int
791smtp_ungetc(int ch)
792{
7e3ce68e 793*--smtp_inptr = ch;
059ec3d9
PH
794return ch;
795}
796
797
7e3ce68e
JH
798int
799bdat_ungetc(int ch)
800{
801chunking_data_left++;
802return lwr_receive_ungetc(ch);
803}
804
059ec3d9
PH
805
806
807/*************************************************
808* SMTP version of feof() *
809*************************************************/
810
811/* Tests for a previous EOF
812
813Arguments: none
814Returns: non-zero if the eof flag is set
815*/
816
817int
818smtp_feof(void)
819{
820return smtp_had_eof;
821}
822
823
824
825
826/*************************************************
827* SMTP version of ferror() *
828*************************************************/
829
830/* Tests for a previous read error, and returns with errno
831restored to what it was when the error was detected.
832
833Arguments: none
834Returns: non-zero if the error flag is set
835*/
836
837int
838smtp_ferror(void)
839{
840errno = smtp_had_error;
841return smtp_had_error;
842}
843
844
845
58eb016e
PH
846/*************************************************
847* Test for characters in the SMTP buffer *
848*************************************************/
849
850/* Used at the end of a message
851
852Arguments: none
853Returns: TRUE/FALSE
854*/
855
856BOOL
857smtp_buffered(void)
858{
859return smtp_inptr < smtp_inend;
860}
861
862
059ec3d9
PH
863
864/*************************************************
865* Write formatted string to SMTP channel *
866*************************************************/
867
868/* This is a separate function so that we don't have to repeat everything for
869TLS support or debugging. It is global so that the daemon and the
870authentication functions can use it. It does not return any error indication,
871because major problems such as dropped connections won't show up till an output
872flush for non-TLS connections. The smtp_fflush() function is available for
873checking that: for convenience, TLS output errors are remembered here so that
874they are also picked up later by smtp_fflush().
875
876Arguments:
877 format format string
925ac8e4 878 more further data expected
059ec3d9
PH
879 ... optional arguments
880
881Returns: nothing
882*/
883
884void
925ac8e4 885smtp_printf(const char *format, BOOL more, ...)
059ec3d9
PH
886{
887va_list ap;
888
925ac8e4
JH
889va_start(ap, more);
890smtp_vprintf(format, more, ap);
ce552449
NM
891va_end(ap);
892}
893
894/* This is split off so that verify.c:respond_printf() can, in effect, call
895smtp_printf(), bearing in mind that in C a vararg function can't directly
fb08281f 896call another vararg function, only a function which accepts a va_list. */
ce552449
NM
897
898void
925ac8e4 899smtp_vprintf(const char *format, BOOL more, va_list ap)
ce552449 900{
fb08281f
DW
901BOOL yield;
902
903yield = string_vformat(big_buffer, big_buffer_size, format, ap);
ce552449 904
059ec3d9
PH
905DEBUG(D_receive)
906 {
fb08281f
DW
907 void *reset_point = store_get(0);
908 uschar *msg_copy, *cr, *end;
909 msg_copy = string_copy(big_buffer);
910 end = msg_copy + Ustrlen(msg_copy);
911 while ((cr = Ustrchr(msg_copy, '\r')) != NULL) /* lose CRs */
912 memmove(cr, cr + 1, (end--) - cr);
913 debug_printf("SMTP>> %s", msg_copy);
914 store_reset(reset_point);
059ec3d9
PH
915 }
916
fb08281f 917if (!yield)
2679d413
PH
918 {
919 log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_printf()");
920 smtp_closedown(US"Unexpected error");
9bfb7e1b 921 exim_exit(EXIT_FAILURE, NULL);
2679d413 922 }
2679d413
PH
923
924/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
925have had the same. Note: this code is also present in smtp_respond(). It would
926be tidier to have it only in one place, but when it was added, it was easier to
927do it that way, so as not to have to mess with the code for the RCPT command,
928which sometimes uses smtp_printf() and sometimes smtp_respond(). */
929
88752192 930if (fl.rcpt_in_progress)
2679d413
PH
931 {
932 if (rcpt_smtp_response == NULL)
933 rcpt_smtp_response = string_copy(big_buffer);
88752192 934 else if (fl.rcpt_smtp_response_same &&
2679d413 935 Ustrcmp(rcpt_smtp_response, big_buffer) != 0)
88752192
JH
936 fl.rcpt_smtp_response_same = FALSE;
937 fl.rcpt_in_progress = FALSE;
2679d413 938 }
059ec3d9 939
2679d413 940/* Now write the string */
059ec3d9
PH
941
942#ifdef SUPPORT_TLS
74f1a423 943if (tls_in.active.sock >= 0)
059ec3d9 944 {
74f1a423 945 if (tls_write(NULL, big_buffer, Ustrlen(big_buffer), more) < 0)
817d9f57 946 smtp_write_error = -1;
059ec3d9
PH
947 }
948else
949#endif
950
2679d413 951if (fprintf(smtp_out, "%s", big_buffer) < 0) smtp_write_error = -1;
059ec3d9
PH
952}
953
954
955
956/*************************************************
957* Flush SMTP out and check for error *
958*************************************************/
959
960/* This function isn't currently used within Exim (it detects errors when it
961tries to read the next SMTP input), but is available for use in local_scan().
962For non-TLS connections, it flushes the output and checks for errors. For
963TLS-connections, it checks for a previously-detected TLS write error.
964
965Arguments: none
966Returns: 0 for no error; -1 after an error
967*/
968
969int
970smtp_fflush(void)
971{
74f1a423 972if (tls_in.active.sock < 0 && fflush(smtp_out) != 0) smtp_write_error = -1;
059ec3d9
PH
973return smtp_write_error;
974}
975
976
977
978/*************************************************
979* SMTP command read timeout *
980*************************************************/
981
982/* Signal handler for timing out incoming SMTP commands. This attempts to
983finish off tidily.
984
985Argument: signal number (SIGALRM)
986Returns: nothing
987*/
988
989static void
990command_timeout_handler(int sig)
991{
9723f966 992had_command_timeout = sig;
059ec3d9
PH
993}
994
995
996
997/*************************************************
998* SIGTERM received *
999*************************************************/
1000
1001/* Signal handler for handling SIGTERM. Again, try to finish tidily.
1002
1003Argument: signal number (SIGTERM)
1004Returns: nothing
1005*/
1006
1007static void
1008command_sigterm_handler(int sig)
1009{
9723f966 1010had_command_sigterm = sig;
059ec3d9
PH
1011}
1012
1013
1014
a14e5636 1015
cee5f132 1016#ifdef SUPPORT_PROXY
a3c86431 1017/*************************************************
a3bddaa8
TL
1018* Restore socket timeout to previous value *
1019*************************************************/
1020/* If the previous value was successfully retrieved, restore
1021it before returning control to the non-proxy routines
1022
1023Arguments: fd - File descriptor for input
1024 get_ok - Successfully retrieved previous values
1025 tvtmp - Time struct with previous values
1026 vslen - Length of time struct
1027Returns: none
1028*/
1029static void
f267271d 1030restore_socket_timeout(int fd, int get_ok, struct timeval * tvtmp, socklen_t vslen)
a3bddaa8
TL
1031{
1032if (get_ok == 0)
f267271d 1033 (void) setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS tvtmp, vslen);
a3bddaa8
TL
1034}
1035
1036/*************************************************
a3c86431
TL
1037* Check if host is required proxy host *
1038*************************************************/
1039/* The function determines if inbound host will be a regular smtp host
1811cb4c
JH
1040or if it is configured that it must use Proxy Protocol. A local
1041connection cannot.
a3c86431
TL
1042
1043Arguments: none
1044Returns: bool
1045*/
1046
1047static BOOL
1048check_proxy_protocol_host()
1049{
1050int rc;
a3c86431 1051
1811cb4c
JH
1052if ( sender_host_address
1053 && (rc = verify_check_this_host(CUSS &hosts_proxy, NULL, NULL,
1054 sender_host_address, NULL)) == OK)
a3c86431
TL
1055 {
1056 DEBUG(D_receive)
1057 debug_printf("Detected proxy protocol configured host\n");
1058 proxy_session = TRUE;
1059 }
1060return proxy_session;
1061}
1062
1063
1064/*************************************************
3f251b3c
PP
1065* Read data until newline or end of buffer *
1066*************************************************/
1067/* While SMTP is server-speaks-first, TLS is client-speaks-first, so we can't
1068read an entire buffer and assume there will be nothing past a proxy protocol
1069header. Our approach normally is to use stdio, but again that relies upon
1070"STARTTLS\r\n" and a server response before the client starts TLS handshake, or
1071reading _nothing_ before client TLS handshake. So we don't want to use the
1072usual buffering reads which may read enough to block TLS starting.
1073
1074So unfortunately we're down to "read one byte at a time, with a syscall each,
1075and expect a little overhead", for all proxy-opened connections which are v1,
1076just to handle the TLS-on-connect case. Since SSL functions wrap the
1077underlying fd, we can't assume that we can feed them any already-read content.
1078
1079We need to know where to read to, the max capacity, and we'll read until we
1080get a CR and one more character. Let the caller scream if it's CR+!LF.
1081
1082Return the amount read.
1083*/
1084
1085static int
da88acae 1086swallow_until_crlf(int fd, uschar *base, int already, int capacity)
3f251b3c 1087{
2c0f3ea1
JH
1088uschar *to = base + already;
1089uschar *cr;
1090int have = 0;
1091int ret;
1092int last = 0;
1093
1094/* For "PROXY UNKNOWN\r\n" we, at time of writing, expect to have read
1095up through the \r; for the _normal_ case, we haven't yet seen the \r. */
da88acae 1096
2c0f3ea1
JH
1097cr = memchr(base, '\r', already);
1098if (cr != NULL)
1099 {
1100 if ((cr - base) < already - 1)
da88acae 1101 {
2c0f3ea1
JH
1102 /* \r and presumed \n already within what we have; probably not
1103 actually proxy protocol, but abort cleanly. */
1104 return 0;
da88acae 1105 }
2c0f3ea1
JH
1106 /* \r is last character read, just need one more. */
1107 last = 1;
1108 }
1109
1110while (capacity > 0)
1111 {
1112 do { ret = recv(fd, to, 1, 0); } while (ret == -1 && errno == EINTR);
1113 if (ret == -1)
1114 return -1;
1115 have++;
1116 if (last)
1117 return have;
1118 if (*to == '\r')
1119 last = 1;
1120 capacity--;
1121 to++;
1122 }
1123
1124/* reached end without having room for a final newline, abort */
1125errno = EOVERFLOW;
1126return -1;
3f251b3c
PP
1127}
1128
1129/*************************************************
a3c86431
TL
1130* Setup host for proxy protocol *
1131*************************************************/
1132/* The function configures the connection based on a header from the
1133inbound host to use Proxy Protocol. The specification is very exact
1134so exit with an error if do not find the exact required pieces. This
1135includes an incorrect number of spaces separating args.
1136
1137Arguments: none
f267271d 1138Returns: Boolean success
a3c86431
TL
1139*/
1140
1811cb4c 1141static void
a3c86431
TL
1142setup_proxy_protocol_host()
1143{
1144union {
1145 struct {
1146 uschar line[108];
1147 } v1;
1148 struct {
1149 uschar sig[12];
36719342
TL
1150 uint8_t ver_cmd;
1151 uint8_t fam;
1152 uint16_t len;
a3c86431
TL
1153 union {
1154 struct { /* TCP/UDP over IPv4, len = 12 */
1155 uint32_t src_addr;
1156 uint32_t dst_addr;
1157 uint16_t src_port;
1158 uint16_t dst_port;
1159 } ip4;
1160 struct { /* TCP/UDP over IPv6, len = 36 */
1161 uint8_t src_addr[16];
1162 uint8_t dst_addr[16];
1163 uint16_t src_port;
1164 uint16_t dst_port;
1165 } ip6;
1166 struct { /* AF_UNIX sockets, len = 216 */
1167 uschar src_addr[108];
1168 uschar dst_addr[108];
1169 } unx;
1170 } addr;
1171 } v2;
1172} hdr;
1173
eb57651e
TL
1174/* Temp variables used in PPv2 address:port parsing */
1175uint16_t tmpport;
1176char tmpip[INET_ADDRSTRLEN];
1177struct sockaddr_in tmpaddr;
1178char tmpip6[INET6_ADDRSTRLEN];
1179struct sockaddr_in6 tmpaddr6;
1180
da88acae
PP
1181/* We can't read "all data until end" because while SMTP is
1182server-speaks-first, the TLS handshake is client-speaks-first, so for
1183TLS-on-connect ports the proxy protocol header will usually be immediately
1184followed by a TLS handshake, and with N TLS libraries, we can't reliably
1185reinject data for reading by those. So instead we first read "enough to be
1186safely read within the header, and figure out how much more to read".
1187For v1 we will later read to the end-of-line, for v2 we will read based upon
1188the stated length.
1189
1190The v2 sig is 12 octets, and another 4 gets us the length, so we know how much
1191data is needed total. For v1, where the line looks like:
1192PROXY TCPn L3src L3dest SrcPort DestPort \r\n
1193
1194However, for v1 there's also `PROXY UNKNOWN\r\n` which is only 15 octets.
1195We seem to support that. So, if we read 14 octets then we can tell if we're
1196v2 or v1. If we're v1, we can continue reading as normal.
1197
1198If we're v2, we can't slurp up the entire header. We need the length in the
119915th & 16th octets, then to read everything after that.
1200
1201So to safely handle v1 and v2, with client-sent-first supported correctly,
1202we have to do a minimum of 3 read calls, not 1. Eww.
1203*/
1204
1205#define PROXY_INITIAL_READ 14
1206#define PROXY_V2_HEADER_SIZE 16
1207#if PROXY_INITIAL_READ > PROXY_V2_HEADER_SIZE
1208# error Code bug in sizes of data to read for proxy usage
1209#endif
1210
eb57651e 1211int get_ok = 0;
f267271d
JH
1212int size, ret;
1213int fd = fileno(smtp_in);
36719342 1214const char v2sig[12] = "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A";
9e7e0f6a 1215uschar * iptype; /* To display debug info */
a3c86431 1216struct timeval tv;
a3bddaa8 1217struct timeval tvtmp;
f267271d 1218socklen_t vslen = sizeof(struct timeval);
1811cb4c 1219BOOL yield = FALSE;
a3c86431 1220
a3bddaa8 1221/* Save current socket timeout values */
f267271d 1222get_ok = getsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS &tvtmp, &vslen);
a3bddaa8 1223
a3c86431
TL
1224/* Proxy Protocol host must send header within a short time
1225(default 3 seconds) or it's considered invalid */
1226tv.tv_sec = PROXY_NEGOTIATION_TIMEOUT_SEC;
1227tv.tv_usec = PROXY_NEGOTIATION_TIMEOUT_USEC;
f267271d 1228if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS &tv, sizeof(tv)) < 0)
1811cb4c 1229 goto bad;
a3bddaa8 1230
a3c86431
TL
1231do
1232 {
eb57651e 1233 /* The inbound host was declared to be a Proxy Protocol host, so
2c0f3ea1
JH
1234 don't do a PEEK into the data, actually slurp up enough to be
1235 "safe". Can't take it all because TLS-on-connect clients follow
1236 immediately with TLS handshake. */
3f251b3c 1237 ret = recv(fd, &hdr, PROXY_INITIAL_READ, 0);
a3c86431
TL
1238 }
1239 while (ret == -1 && errno == EINTR);
1240
1241if (ret == -1)
f267271d 1242 goto proxyfail;
a3c86431 1243
da88acae
PP
1244/* For v2, handle reading the length, and then the rest. */
1245if ((ret == PROXY_INITIAL_READ) && (memcmp(&hdr.v2, v2sig, sizeof(v2sig)) == 0))
a3c86431 1246 {
da88acae
PP
1247 int retmore;
1248 uint8_t ver;
1249
1250 /* First get the length fields. */
1251 do
1252 {
1253 retmore = recv(fd, (uschar*)&hdr + ret, PROXY_V2_HEADER_SIZE - PROXY_INITIAL_READ, 0);
1254 } while (retmore == -1 && errno == EINTR);
1255 if (retmore == -1)
3f251b3c 1256 goto proxyfail;
da88acae 1257 ret += retmore;
3f251b3c
PP
1258
1259 ver = (hdr.v2.ver_cmd & 0xf0) >> 4;
36719342
TL
1260
1261 /* May 2014: haproxy combined the version and command into one byte to
2c0f3ea1
JH
1262 allow two full bytes for the length field in order to proxy SSL
1263 connections. SSL Proxy is not supported in this version of Exim, but
1264 must still separate values here. */
36719342
TL
1265
1266 if (ver != 0x02)
1267 {
1268 DEBUG(D_receive) debug_printf("Invalid Proxy Protocol version: %d\n", ver);
1269 goto proxyfail;
1270 }
da88acae 1271
36719342 1272 /* The v2 header will always be 16 bytes per the spec. */
5d036699 1273 size = 16 + ntohs(hdr.v2.len);
da88acae
PP
1274 DEBUG(D_receive) debug_printf("Detected PROXYv2 header, size %d (limit %d)\n",
1275 size, (int)sizeof(hdr));
1276
1277 /* We should now have 16 octets (PROXY_V2_HEADER_SIZE), and we know the total
1278 amount that we need. Double-check that the size is not unreasonable, then
1279 get the rest. */
1280 if (size > sizeof(hdr))
a3c86431 1281 {
da88acae 1282 DEBUG(D_receive) debug_printf("PROXYv2 header size unreasonably large; security attack?\n");
a3c86431
TL
1283 goto proxyfail;
1284 }
da88acae
PP
1285
1286 do
1287 {
1288 do
1289 {
1290 retmore = recv(fd, (uschar*)&hdr + ret, size-ret, 0);
1291 } while (retmore == -1 && errno == EINTR);
1292 if (retmore == -1)
1293 goto proxyfail;
1294 ret += retmore;
1295 DEBUG(D_receive) debug_printf("PROXYv2: have %d/%d required octets\n", ret, size);
1296 } while (ret < size);
1297
1298 } /* end scope for getting rest of data for v2 */
1299
1300/* At this point: if PROXYv2, we've read the exact size required for all data;
1301if PROXYv1 then we've read "less than required for any valid line" and should
1302read the rest". */
1303
1304if (ret >= 16 && memcmp(&hdr.v2, v2sig, 12) == 0)
1305 {
1306 uint8_t cmd = (hdr.v2.ver_cmd & 0x0f);
1307
36719342 1308 switch (cmd)
a3c86431
TL
1309 {
1310 case 0x01: /* PROXY command */
1311 switch (hdr.v2.fam)
1312 {
eb57651e
TL
1313 case 0x11: /* TCPv4 address type */
1314 iptype = US"IPv4";
1315 tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.src_addr;
5d036699
JH
1316 inet_ntop(AF_INET, &tmpaddr.sin_addr, CS &tmpip, sizeof(tmpip));
1317 if (!string_is_ip_address(US tmpip, NULL))
eb57651e
TL
1318 {
1319 DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
f267271d 1320 goto proxyfail;
eb57651e 1321 }
e6d2a989 1322 proxy_local_address = sender_host_address;
eb57651e
TL
1323 sender_host_address = string_copy(US tmpip);
1324 tmpport = ntohs(hdr.v2.addr.ip4.src_port);
e6d2a989 1325 proxy_local_port = sender_host_port;
eb57651e
TL
1326 sender_host_port = tmpport;
1327 /* Save dest ip/port */
1328 tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.dst_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 dest port\n", iptype);
f267271d 1333 goto proxyfail;
eb57651e 1334 }
7a2fa0bc 1335 proxy_external_address = string_copy(US tmpip);
eb57651e 1336 tmpport = ntohs(hdr.v2.addr.ip4.dst_port);
7a2fa0bc 1337 proxy_external_port = tmpport;
a3c86431 1338 goto done;
eb57651e
TL
1339 case 0x21: /* TCPv6 address type */
1340 iptype = US"IPv6";
1341 memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.src_addr, 16);
5d036699
JH
1342 inet_ntop(AF_INET6, &tmpaddr6.sin6_addr, CS &tmpip6, sizeof(tmpip6));
1343 if (!string_is_ip_address(US tmpip6, NULL))
eb57651e
TL
1344 {
1345 DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
f267271d 1346 goto proxyfail;
eb57651e 1347 }
e6d2a989 1348 proxy_local_address = sender_host_address;
eb57651e
TL
1349 sender_host_address = string_copy(US tmpip6);
1350 tmpport = ntohs(hdr.v2.addr.ip6.src_port);
e6d2a989 1351 proxy_local_port = sender_host_port;
eb57651e
TL
1352 sender_host_port = tmpport;
1353 /* Save dest ip/port */
1354 memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.dst_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 dest port\n", iptype);
f267271d 1359 goto proxyfail;
eb57651e 1360 }
7a2fa0bc 1361 proxy_external_address = string_copy(US tmpip6);
eb57651e 1362 tmpport = ntohs(hdr.v2.addr.ip6.dst_port);
7a2fa0bc 1363 proxy_external_port = tmpport;
a3c86431 1364 goto done;
eb57651e
TL
1365 default:
1366 DEBUG(D_receive)
1367 debug_printf("Unsupported PROXYv2 connection type: 0x%02x\n",
1368 hdr.v2.fam);
1369 goto proxyfail;
a3c86431
TL
1370 }
1371 /* Unsupported protocol, keep local connection address */
1372 break;
1373 case 0x00: /* LOCAL command */
1374 /* Keep local connection address for LOCAL */
9e7e0f6a 1375 iptype = US"local";
a3c86431
TL
1376 break;
1377 default:
eb57651e 1378 DEBUG(D_receive)
36719342 1379 debug_printf("Unsupported PROXYv2 command: 0x%x\n", cmd);
a3c86431
TL
1380 goto proxyfail;
1381 }
1382 }
5d036699 1383else if (ret >= 8 && memcmp(hdr.v1.line, "PROXY", 5) == 0)
a3c86431 1384 {
3f251b3c
PP
1385 uschar *p;
1386 uschar *end;
a3c86431
TL
1387 uschar *sp; /* Utility variables follow */
1388 int tmp_port;
3f251b3c 1389 int r2;
a3c86431
TL
1390 char *endc;
1391
3f251b3c 1392 /* get the rest of the line */
da88acae 1393 r2 = swallow_until_crlf(fd, (uschar*)&hdr, ret, sizeof(hdr)-ret);
3f251b3c
PP
1394 if (r2 == -1)
1395 goto proxyfail;
1396 ret += r2;
1397
1398 p = string_copy(hdr.v1.line);
1399 end = memchr(p, '\r', ret - 1);
1400
da88acae 1401 if (!end || (end == (uschar*)&hdr + ret) || end[1] != '\n')
a3c86431
TL
1402 {
1403 DEBUG(D_receive) debug_printf("Partial or invalid PROXY header\n");
1404 goto proxyfail;
1405 }
1406 *end = '\0'; /* Terminate the string */
a5d4db40 1407 size = end + 2 - p; /* Skip header + CRLF */
a3c86431 1408 DEBUG(D_receive) debug_printf("Detected PROXYv1 header\n");
3f251b3c 1409 DEBUG(D_receive) debug_printf("Bytes read not within PROXY header: %d\n", ret - size);
a3c86431 1410 /* Step through the string looking for the required fields. Ensure
2c0f3ea1 1411 strict adherence to required formatting, exit for any error. */
a3c86431
TL
1412 p += 5;
1413 if (!isspace(*(p++)))
1414 {
1415 DEBUG(D_receive) debug_printf("Missing space after PROXY command\n");
1416 goto proxyfail;
1417 }
1418 if (!Ustrncmp(p, CCS"TCP4", 4))
1419 iptype = US"IPv4";
1420 else if (!Ustrncmp(p,CCS"TCP6", 4))
1421 iptype = US"IPv6";
1422 else if (!Ustrncmp(p,CCS"UNKNOWN", 7))
1423 {
1424 iptype = US"Unknown";
1425 goto done;
1426 }
1427 else
1428 {
1429 DEBUG(D_receive) debug_printf("Invalid TCP type\n");
1430 goto proxyfail;
1431 }
1432
1433 p += Ustrlen(iptype);
1434 if (!isspace(*(p++)))
1435 {
1436 DEBUG(D_receive) debug_printf("Missing space after TCP4/6 command\n");
1437 goto proxyfail;
1438 }
1439 /* Find the end of the arg */
1440 if ((sp = Ustrchr(p, ' ')) == NULL)
1441 {
1442 DEBUG(D_receive)
1443 debug_printf("Did not find proxied src %s\n", iptype);
1444 goto proxyfail;
1445 }
1446 *sp = '\0';
5d036699 1447 if(!string_is_ip_address(p, NULL))
a3c86431
TL
1448 {
1449 DEBUG(D_receive)
1450 debug_printf("Proxied src arg is not an %s address\n", iptype);
1451 goto proxyfail;
1452 }
e6d2a989 1453 proxy_local_address = sender_host_address;
a3c86431
TL
1454 sender_host_address = p;
1455 p = sp + 1;
1456 if ((sp = Ustrchr(p, ' ')) == NULL)
1457 {
1458 DEBUG(D_receive)
1459 debug_printf("Did not find proxy dest %s\n", iptype);
1460 goto proxyfail;
1461 }
1462 *sp = '\0';
5d036699 1463 if(!string_is_ip_address(p, NULL))
a3c86431
TL
1464 {
1465 DEBUG(D_receive)
1466 debug_printf("Proxy dest arg is not an %s address\n", iptype);
1467 goto proxyfail;
1468 }
7a2fa0bc 1469 proxy_external_address = p;
a3c86431
TL
1470 p = sp + 1;
1471 if ((sp = Ustrchr(p, ' ')) == NULL)
1472 {
1473 DEBUG(D_receive) debug_printf("Did not find proxied src port\n");
1474 goto proxyfail;
1475 }
1476 *sp = '\0';
5d036699 1477 tmp_port = strtol(CCS p, &endc, 10);
a3c86431
TL
1478 if (*endc || tmp_port == 0)
1479 {
1480 DEBUG(D_receive)
1481 debug_printf("Proxied src port '%s' not an integer\n", p);
1482 goto proxyfail;
1483 }
e6d2a989 1484 proxy_local_port = sender_host_port;
a3c86431
TL
1485 sender_host_port = tmp_port;
1486 p = sp + 1;
1487 if ((sp = Ustrchr(p, '\0')) == NULL)
1488 {
1489 DEBUG(D_receive) debug_printf("Did not find proxy dest port\n");
1490 goto proxyfail;
1491 }
5d036699 1492 tmp_port = strtol(CCS p, &endc, 10);
a3c86431
TL
1493 if (*endc || tmp_port == 0)
1494 {
1495 DEBUG(D_receive)
1496 debug_printf("Proxy dest port '%s' not an integer\n", p);
1497 goto proxyfail;
1498 }
7a2fa0bc 1499 proxy_external_port = tmp_port;
a3c86431 1500 /* Already checked for /r /n above. Good V1 header received. */
a3c86431
TL
1501 }
1502else
1503 {
1504 /* Wrong protocol */
eb57651e 1505 DEBUG(D_receive) debug_printf("Invalid proxy protocol version negotiation\n");
da88acae 1506 (void) swallow_until_crlf(fd, (uschar*)&hdr, ret, sizeof(hdr)-ret);
a3c86431
TL
1507 goto proxyfail;
1508 }
1509
1811cb4c
JH
1510done:
1511 DEBUG(D_receive)
1512 debug_printf("Valid %s sender from Proxy Protocol header\n", iptype);
1513 yield = proxy_session;
1514
1515/* Don't flush any potential buffer contents. Any input on proxyfail
1516should cause a synchronization failure */
1517
a3c86431 1518proxyfail:
1811cb4c 1519 restore_socket_timeout(fd, get_ok, &tvtmp, vslen);
a3c86431 1520
1811cb4c
JH
1521bad:
1522 if (yield)
1523 {
1524 sender_host_name = NULL;
1525 (void) host_name_lookup();
1526 host_build_sender_fullhost();
1527 }
1528 else
1529 {
8768d548 1530 f.proxy_session_failed = TRUE;
1811cb4c
JH
1531 DEBUG(D_receive)
1532 debug_printf("Failure to extract proxied host, only QUIT allowed\n");
1533 }
1534
1535return;
a3c86431
TL
1536}
1537#endif
1538
059ec3d9
PH
1539/*************************************************
1540* Read one command line *
1541*************************************************/
1542
1543/* Strictly, SMTP commands coming over the net are supposed to end with CRLF.
1544There are sites that don't do this, and in any case internal SMTP probably
1545should check only for LF. Consequently, we check here for LF only. The line
1546ends up with [CR]LF removed from its end. If we get an overlong line, treat as
3ee512ff
PH
1547an unknown command. The command is read into the global smtp_cmd_buffer so that
1548it is available via $smtp_command.
059ec3d9
PH
1549
1550The character reading routine sets up a timeout for each block actually read
1551from the input (which may contain more than one command). We set up a special
1552signal handler that closes down the session on a timeout. Control does not
1553return when it runs.
1554
1555Arguments:
bd8fbe36
JH
1556 check_sync if TRUE, check synchronization rules if global option is TRUE
1557 buffer_lim maximum to buffer in lower layer
059ec3d9
PH
1558
1559Returns: a code identifying the command (enumerated above)
1560*/
1561
1562static int
bd8fbe36 1563smtp_read_command(BOOL check_sync, unsigned buffer_lim)
059ec3d9
PH
1564{
1565int c;
1566int ptr = 0;
1567smtp_cmd_list *p;
1568BOOL hadnull = FALSE;
1569
9723f966 1570had_command_timeout = 0;
059ec3d9
PH
1571os_non_restarting_signal(SIGALRM, command_timeout_handler);
1572
bd8fbe36 1573while ((c = (receive_getc)(buffer_lim)) != '\n' && c != EOF)
059ec3d9 1574 {
bd8fbe36 1575 if (ptr >= SMTP_CMD_BUFFER_SIZE)
059ec3d9
PH
1576 {
1577 os_non_restarting_signal(SIGALRM, sigalrm_handler);
1578 return OTHER_CMD;
1579 }
1580 if (c == 0)
1581 {
1582 hadnull = TRUE;
1583 c = '?';
1584 }
3ee512ff 1585 smtp_cmd_buffer[ptr++] = c;
059ec3d9
PH
1586 }
1587
1588receive_linecount++; /* For BSMTP errors */
1589os_non_restarting_signal(SIGALRM, sigalrm_handler);
1590
1591/* If hit end of file, return pseudo EOF command. Whether we have a
1592part-line already read doesn't matter, since this is an error state. */
1593
1594if (c == EOF) return EOF_CMD;
1595
1596/* Remove any CR and white space at the end of the line, and terminate the
1597string. */
1598
3ee512ff
PH
1599while (ptr > 0 && isspace(smtp_cmd_buffer[ptr-1])) ptr--;
1600smtp_cmd_buffer[ptr] = 0;
059ec3d9 1601
3ee512ff 1602DEBUG(D_receive) debug_printf("SMTP<< %s\n", smtp_cmd_buffer);
059ec3d9
PH
1603
1604/* NULLs are not allowed in SMTP commands */
1605
1606if (hadnull) return BADCHAR_CMD;
1607
1608/* Scan command list and return identity, having set the data pointer
1609to the start of the actual data characters. Check for SMTP synchronization
1610if required. */
1611
1612for (p = cmd_list; p < cmd_list_end; p++)
1613 {
1811cb4c 1614#ifdef SUPPORT_PROXY
a3c86431 1615 /* Only allow QUIT command if Proxy Protocol parsing failed */
8768d548 1616 if (proxy_session && f.proxy_session_failed && p->cmd != QUIT_CMD)
1811cb4c
JH
1617 continue;
1618#endif
2f460950
JH
1619 if ( p->len
1620 && strncmpic(smtp_cmd_buffer, US p->name, p->len) == 0
1621 && ( smtp_cmd_buffer[p->len-1] == ':' /* "mail from:" or "rcpt to:" */
1622 || smtp_cmd_buffer[p->len] == 0
1623 || smtp_cmd_buffer[p->len] == ' '
1624 ) )
059ec3d9
PH
1625 {
1626 if (smtp_inptr < smtp_inend && /* Outstanding input */
1627 p->cmd < sync_cmd_limit && /* Command should sync */
1628 check_sync && /* Local flag set */
1629 smtp_enforce_sync && /* Global flag set */
1630 sender_host_address != NULL && /* Not local input */
8768d548 1631 !f.sender_host_notsocket) /* Really is a socket */
059ec3d9
PH
1632 return BADSYN_CMD;
1633
ca86f471
PH
1634 /* The variables $smtp_command and $smtp_command_argument point into the
1635 unmodified input buffer. A copy of the latter is taken for actual
1636 processing, so that it can be chopped up into separate parts if necessary,
1637 for example, when processing a MAIL command options such as SIZE that can
1638 follow the sender address. */
059ec3d9 1639
3ee512ff 1640 smtp_cmd_argument = smtp_cmd_buffer + p->len;
ca86f471
PH
1641 while (isspace(*smtp_cmd_argument)) smtp_cmd_argument++;
1642 Ustrcpy(smtp_data_buffer, smtp_cmd_argument);
1643 smtp_cmd_data = smtp_data_buffer;
059ec3d9
PH
1644
1645 /* Count non-mail commands from those hosts that are controlled in this
1646 way. The default is all hosts. We don't waste effort checking the list
1647 until we get a non-mail command, but then cache the result to save checking
1648 again. If there's a DEFER while checking the host, assume it's in the list.
1649
1650 Note that one instance of RSET, EHLO/HELO, and STARTTLS is allowed at the
1651 start of each incoming message by fiddling with the value in the table. */
1652
1653 if (!p->is_mail_cmd)
1654 {
1655 if (count_nonmail == TRUE_UNSET) count_nonmail =
1656 verify_check_host(&smtp_accept_max_nonmail_hosts) != FAIL;
1657 if (count_nonmail && ++nonmail_command_count > smtp_accept_max_nonmail)
1658 return TOO_MANY_NONMAIL_CMD;
1659 }
1660
ca86f471
PH
1661 /* If there is data for a command that does not expect it, generate the
1662 error here. */
059ec3d9 1663
ca86f471 1664 return (p->has_arg || *smtp_cmd_data == 0)? p->cmd : BADARG_CMD;
059ec3d9
PH
1665 }
1666 }
1667
cee5f132 1668#ifdef SUPPORT_PROXY
a3c86431 1669/* Only allow QUIT command if Proxy Protocol parsing failed */
8768d548 1670if (proxy_session && f.proxy_session_failed)
a3c86431
TL
1671 return PROXY_FAIL_IGNORE_CMD;
1672#endif
1673
059ec3d9
PH
1674/* Enforce synchronization for unknown commands */
1675
ecce6d9a
JH
1676if ( smtp_inptr < smtp_inend /* Outstanding input */
1677 && check_sync /* Local flag set */
1678 && smtp_enforce_sync /* Global flag set */
1679 && sender_host_address /* Not local input */
8768d548 1680 && !f.sender_host_notsocket) /* Really is a socket */
059ec3d9
PH
1681 return BADSYN_CMD;
1682
1683return OTHER_CMD;
1684}
1685
1686
1687
1688/*************************************************
1689* Forced closedown of call *
1690*************************************************/
1691
1692/* This function is called from log.c when Exim is dying because of a serious
1693disaster, and also from some other places. If an incoming non-batched SMTP
1694channel is open, it swallows the rest of the incoming message if in the DATA
1695phase, sends the reply string, and gives an error to all subsequent commands
1696except QUIT. The existence of an SMTP call is detected by the non-NULLness of
1697smtp_in.
1698
8f128379
PH
1699Arguments:
1700 message SMTP reply string to send, excluding the code
1701
059ec3d9
PH
1702Returns: nothing
1703*/
1704
1705void
1706smtp_closedown(uschar *message)
1707{
db57e575 1708if (!smtp_in || smtp_batched_input) return;
059ec3d9 1709receive_swallow_smtp();
925ac8e4 1710smtp_printf("421 %s\r\n", FALSE, message);
059ec3d9 1711
bd8fbe36 1712for (;;) switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED))
059ec3d9 1713 {
60d10ce7 1714 case EOF_CMD:
db57e575 1715 return;
059ec3d9 1716
60d10ce7 1717 case QUIT_CMD:
db57e575
JH
1718 smtp_printf("221 %s closing connection\r\n", FALSE, smtp_active_hostname);
1719 mac_smtp_fflush();
1720 return;
059ec3d9 1721
60d10ce7 1722 case RSET_CMD:
db57e575
JH
1723 smtp_printf("250 Reset OK\r\n", FALSE);
1724 break;
059ec3d9 1725
60d10ce7 1726 default:
db57e575
JH
1727 smtp_printf("421 %s\r\n", FALSE, message);
1728 break;
059ec3d9
PH
1729 }
1730}
1731
1732
1733
1734
1735/*************************************************
1736* Set up connection info for logging *
1737*************************************************/
1738
1739/* This function is called when logging information about an SMTP connection.
1740It sets up appropriate source information, depending on the type of connection.
dac79d3e
PH
1741If sender_fullhost is NULL, we are at a very early stage of the connection;
1742just use the IP address.
059ec3d9
PH
1743
1744Argument: none
1745Returns: a string describing the connection
1746*/
1747
1748uschar *
1749smtp_get_connection_info(void)
1750{
f5d25c2b
JH
1751const uschar * hostname = sender_fullhost
1752 ? sender_fullhost : sender_host_address;
dac79d3e 1753
059ec3d9 1754if (host_checking)
dac79d3e 1755 return string_sprintf("SMTP connection from %s", hostname);
059ec3d9 1756
8768d548 1757if (f.sender_host_unknown || f.sender_host_notsocket)
059ec3d9
PH
1758 return string_sprintf("SMTP connection from %s", sender_ident);
1759
8768d548 1760if (f.is_inetd)
dac79d3e 1761 return string_sprintf("SMTP connection from %s (via inetd)", hostname);
059ec3d9 1762
6c6d6e48 1763if (LOGGING(incoming_interface) && interface_address != NULL)
dac79d3e 1764 return string_sprintf("SMTP connection from %s I=[%s]:%d", hostname,
059ec3d9
PH
1765 interface_address, interface_port);
1766
dac79d3e 1767return string_sprintf("SMTP connection from %s", hostname);
059ec3d9
PH
1768}
1769
1770
1771
e45a1c37 1772#ifdef SUPPORT_TLS
887291d2
JH
1773/* Append TLS-related information to a log line
1774
1775Arguments:
acec9514 1776 g String under construction: allocated string to extend, or NULL
887291d2
JH
1777
1778Returns: Allocated string or NULL
1779*/
acec9514
JH
1780static gstring *
1781s_tlslog(gstring * g)
e45a1c37 1782{
acec9514
JH
1783if (LOGGING(tls_cipher) && tls_in.cipher)
1784 g = string_append(g, 2, US" X=", tls_in.cipher);
1785if (LOGGING(tls_certificate_verified) && tls_in.cipher)
1786 g = string_append(g, 2, US" CV=", tls_in.certificate_verified? "yes":"no");
1787if (LOGGING(tls_peerdn) && tls_in.peerdn)
1788 g = string_append(g, 3, US" DN=\"", string_printing(tls_in.peerdn), US"\"");
1789if (LOGGING(tls_sni) && tls_in.sni)
1790 g = string_append(g, 3, US" SNI=\"", string_printing(tls_in.sni), US"\"");
1791return g;
e45a1c37
JH
1792}
1793#endif
1794
059ec3d9 1795/*************************************************
b4ed4da0
PH
1796* Log lack of MAIL if so configured *
1797*************************************************/
1798
1799/* This function is called when an SMTP session ends. If the log selector
1800smtp_no_mail is set, write a log line giving some details of what has happened
1801in the SMTP session.
1802
1803Arguments: none
1804Returns: nothing
1805*/
1806
1807void
1808smtp_log_no_mail(void)
1809{
acec9514
JH
1810int i;
1811uschar * sep, * s;
1812gstring * g = NULL;
b4ed4da0 1813
6c6d6e48 1814if (smtp_mailcmd_count > 0 || !LOGGING(smtp_no_mail))
b4ed4da0
PH
1815 return;
1816
db57e575 1817if (sender_host_authenticated)
b4ed4da0 1818 {
acec9514
JH
1819 g = string_append(g, 2, US" A=", sender_host_authenticated);
1820 if (authenticated_id) g = string_append(g, 2, US":", authenticated_id);
b4ed4da0
PH
1821 }
1822
1823#ifdef SUPPORT_TLS
acec9514 1824g = s_tlslog(g);
3f0945ff 1825#endif
b4ed4da0 1826
acec9514
JH
1827sep = smtp_connection_had[SMTP_HBUFF_SIZE-1] != SCH_NONE ? US" C=..." : US" C=";
1828
b4ed4da0 1829for (i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++)
b4ed4da0
PH
1830 if (smtp_connection_had[i] != SCH_NONE)
1831 {
acec9514 1832 g = string_append(g, 2, sep, smtp_names[smtp_connection_had[i]]);
b4ed4da0
PH
1833 sep = US",";
1834 }
b4ed4da0
PH
1835
1836for (i = 0; i < smtp_ch_index; i++)
1837 {
acec9514 1838 g = string_append(g, 2, sep, smtp_names[smtp_connection_had[i]]);
b4ed4da0
PH
1839 sep = US",";
1840 }
1841
acec9514
JH
1842if (!(s = string_from_gstring(g))) s = US"";
1843
a2673768 1844log_write(0, LOG_MAIN, "no MAIL in %sSMTP connection from %s D=%s%s",
8768d548 1845 f.tcp_in_fastopen ? US"TFO " : US"",
0f1a8658 1846 host_and_ident(FALSE), string_timesince(&smtp_connection_start), s);
b4ed4da0
PH
1847}
1848
1849
a09f2942
JH
1850/* Return list of recent smtp commands */
1851
1852uschar *
1853smtp_cmd_hist(void)
1854{
acec9514
JH
1855int i;
1856gstring * list = NULL;
1857uschar * s;
a09f2942
JH
1858
1859for (i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++)
1860 if (smtp_connection_had[i] != SCH_NONE)
acec9514
JH
1861 list = string_append_listele(list, ',', smtp_names[smtp_connection_had[i]]);
1862
a09f2942 1863for (i = 0; i < smtp_ch_index; i++)
acec9514
JH
1864 list = string_append_listele(list, ',', smtp_names[smtp_connection_had[i]]);
1865
1866s = string_from_gstring(list);
1867return s ? s : US"";
a09f2942
JH
1868}
1869
1870
1871
b4ed4da0
PH
1872
1873/*************************************************
059ec3d9
PH
1874* Check HELO line and set sender_helo_name *
1875*************************************************/
1876
1877/* Check the format of a HELO line. The data for HELO/EHLO is supposed to be
1878the domain name of the sending host, or an ip literal in square brackets. The
4c04137d 1879argument is placed in sender_helo_name, which is in malloc store, because it
059ec3d9
PH
1880must persist over multiple incoming messages. If helo_accept_junk is set, this
1881host is permitted to send any old junk (needed for some broken hosts).
1882Otherwise, helo_allow_chars can be used for rogue characters in general
1883(typically people want to let in underscores).
1884
1885Argument:
1886 s the data portion of the line (already past any white space)
1887
1888Returns: TRUE or FALSE
1889*/
1890
1891static BOOL
1892check_helo(uschar *s)
1893{
1894uschar *start = s;
1895uschar *end = s + Ustrlen(s);
88752192 1896BOOL yield = fl.helo_accept_junk;
059ec3d9
PH
1897
1898/* Discard any previous helo name */
1899
2d0dc929 1900if (sender_helo_name)
059ec3d9
PH
1901 {
1902 store_free(sender_helo_name);
1903 sender_helo_name = NULL;
1904 }
1905
1906/* Skip tests if junk is permitted. */
1907
1908if (!yield)
db57e575 1909
059ec3d9
PH
1910 /* Allow the new standard form for IPv6 address literals, namely,
1911 [IPv6:....], and because someone is bound to use it, allow an equivalent
1912 IPv4 form. Allow plain addresses as well. */
1913
1914 if (*s == '[')
1915 {
1916 if (end[-1] == ']')
1917 {
1918 end[-1] = 0;
1919 if (strncmpic(s, US"[IPv6:", 6) == 0)
1920 yield = (string_is_ip_address(s+6, NULL) == 6);
1921 else if (strncmpic(s, US"[IPv4:", 6) == 0)
1922 yield = (string_is_ip_address(s+6, NULL) == 4);
1923 else
1924 yield = (string_is_ip_address(s+1, NULL) != 0);
1925 end[-1] = ']';
1926 }
1927 }
1928
1929 /* Non-literals must be alpha, dot, hyphen, plus any non-valid chars
1930 that have been configured (usually underscore - sigh). */
1931
db57e575
JH
1932 else if (*s)
1933 for (yield = TRUE; *s; s++)
059ec3d9
PH
1934 if (!isalnum(*s) && *s != '.' && *s != '-' &&
1935 Ustrchr(helo_allow_chars, *s) == NULL)
1936 {
1937 yield = FALSE;
1938 break;
1939 }
059ec3d9
PH
1940
1941/* Save argument if OK */
1942
1943if (yield) sender_helo_name = string_copy_malloc(start);
1944return yield;
1945}
1946
1947
1948
1949
1950
1951/*************************************************
1952* Extract SMTP command option *
1953*************************************************/
1954
ca86f471 1955/* This function picks the next option setting off the end of smtp_cmd_data. It
059ec3d9
PH
1956is called for MAIL FROM and RCPT TO commands, to pick off the optional ESMTP
1957things that can appear there.
1958
1959Arguments:
1960 name point this at the name
1961 value point this at the data string
1962
1963Returns: TRUE if found an option
1964*/
1965
1966static BOOL
1967extract_option(uschar **name, uschar **value)
1968{
1969uschar *n;
ca86f471 1970uschar *v = smtp_cmd_data + Ustrlen(smtp_cmd_data) - 1;
059ec3d9
PH
1971while (isspace(*v)) v--;
1972v[1] = 0;
d7a2c833
JH
1973while (v > smtp_cmd_data && *v != '=' && !isspace(*v))
1974 {
1975 /* Take care to not stop at a space embedded in a quoted local-part */
1976
1977 if (*v == '"') do v--; while (*v != '"' && v > smtp_cmd_data+1);
1978 v--;
1979 }
059ec3d9
PH
1980
1981n = v;
fd98a5c6 1982if (*v == '=')
a2673768 1983 {
fd98a5c6
JH
1984 while(isalpha(n[-1])) n--;
1985 /* RFC says SP, but TAB seen in wild and other major MTAs accept it */
1986 if (!isspace(n[-1])) return FALSE;
1987 n[-1] = 0;
a2673768 1988 }
fd98a5c6 1989else
a2673768 1990 {
fd98a5c6
JH
1991 n++;
1992 if (v == smtp_cmd_data) return FALSE;
a2673768 1993 }
059ec3d9 1994*v++ = 0;
fd98a5c6 1995*name = n;
059ec3d9
PH
1996*value = v;
1997return TRUE;
1998}
1999
2000
2001
2002
2003
059ec3d9
PH
2004/*************************************************
2005* Reset for new message *
2006*************************************************/
2007
2008/* This function is called whenever the SMTP session is reset from
e04bfa34 2009within either of the setup functions; also from the daemon loop.
059ec3d9
PH
2010
2011Argument: the stacking pool storage reset point
2012Returns: nothing
2013*/
2014
e04bfa34 2015void
059ec3d9
PH
2016smtp_reset(void *reset_point)
2017{
059ec3d9
PH
2018recipients_list = NULL;
2019rcpt_count = rcpt_defer_count = rcpt_fail_count =
2020 raw_recipients_count = recipients_count = recipients_list_max = 0;
2e0c1448 2021message_linecount = 0;
059ec3d9 2022message_size = -1;
71fafd95 2023acl_added_headers = NULL;
e7568d51 2024acl_removed_headers = NULL;
8768d548 2025f.queue_only_policy = FALSE;
2679d413 2026rcpt_smtp_response = NULL;
88752192
JH
2027fl.rcpt_smtp_response_same = TRUE;
2028fl.rcpt_in_progress = FALSE;
8768d548 2029f.deliver_freeze = FALSE; /* Can be set by ACL */
6a3f1455 2030freeze_tell = freeze_tell_config; /* Can be set by ACL */
29aba418 2031fake_response = OK; /* Can be set by ACL */
6951ac6c 2032#ifdef WITH_CONTENT_SCAN
8768d548 2033f.no_mbox_unspool = FALSE; /* Can be set by ACL */
8523533c 2034#endif
8768d548
JH
2035f.submission_mode = FALSE; /* Can be set by ACL */
2036f.suppress_local_fixups = f.suppress_local_fixups_default; /* Can be set by ACL */
2037f.active_local_from_check = local_from_check; /* Can be set by ACL */
2038f.active_local_sender_retain = local_sender_retain; /* Can be set by ACL */
90341c71
JH
2039sending_ip_address = NULL;
2040return_path = sender_address = NULL;
2041sender_data = NULL; /* Can be set by ACL */
c679ee08
JH
2042deliver_localpart_parent = deliver_localpart_orig = NULL;
2043deliver_domain_parent = deliver_domain_orig = NULL;
90341c71 2044callout_address = NULL;
2fe1a124 2045submission_name = NULL; /* Can be set by ACL */
059ec3d9
PH
2046raw_sender = NULL; /* After SMTP rewrite, before qualifying */
2047sender_address_unrewritten = NULL; /* Set only after verify rewrite */
2048sender_verified_list = NULL; /* No senders verified */
2049memset(sender_address_cache, 0, sizeof(sender_address_cache));
2050memset(sender_domain_cache, 0, sizeof(sender_domain_cache));
6c1c3d1d 2051
059ec3d9 2052authenticated_sender = NULL;
8523533c
TK
2053#ifdef EXPERIMENTAL_BRIGHTMAIL
2054bmi_run = 0;
2055bmi_verdicts = NULL;
2056#endif
90341c71 2057dnslist_domain = dnslist_matched = NULL;
01067968
JH
2058#ifdef SUPPORT_SPF
2059spf_header_comment = spf_received = spf_result = spf_smtp_comment = NULL;
2060spf_result_guessed = FALSE;
2061#endif
80a47a2c 2062#ifndef DISABLE_DKIM
d342446f 2063dkim_cur_signer = dkim_signers =
b4757e36 2064dkim_signing_domain = dkim_signing_selector = dkim_signatures = NULL;
d342446f 2065dkim_cur_signer = dkim_signers = dkim_signing_domain = dkim_signing_selector = NULL;
8768d548 2066f.dkim_disable_verify = FALSE;
64b67b65 2067dkim_collect_input = 0;
d342446f
JH
2068dkim_verify_overall = dkim_verify_status = dkim_verify_reason = NULL;
2069dkim_key_length = 0;
2070dkim_verify_signers = US"$dkim_signers";
f7572e5a 2071#endif
b4757e36 2072#ifdef EXPERIMENTAL_DMARC
8768d548 2073f.dmarc_has_been_checked = f.dmarc_disable_verify = f.dmarc_enable_forensic = FALSE;
8aeef98a 2074dmarc_domain_policy = dmarc_status = dmarc_status_text =
6372d4c9 2075dmarc_used_domain = NULL;
f7572e5a 2076#endif
01067968
JH
2077#ifdef EXPERIMENTAL_ARC
2078arc_state = arc_state_reason = NULL;
b4757e36 2079#endif
aa368db3
JH
2080dsn_ret = 0;
2081dsn_envid = NULL;
90341c71 2082deliver_host = deliver_host_address = NULL; /* Can be set by ACL */
aa368db3
JH
2083#ifndef DISABLE_PRDR
2084prdr_requested = FALSE;
2085#endif
8c5d388a 2086#ifdef SUPPORT_I18N
d1a13eea
JH
2087message_smtputf8 = FALSE;
2088#endif
059ec3d9
PH
2089body_linecount = body_zerocount = 0;
2090
870f6ba8
TF
2091sender_rate = sender_rate_limit = sender_rate_period = NULL;
2092ratelimiters_mail = NULL; /* Updated by ratelimit ACL condition */
2093 /* Note that ratelimiters_conn persists across resets. */
2094
38a0a95f 2095/* Reset message ACL variables */
47ca6d6c 2096
38a0a95f 2097acl_var_m = NULL;
059ec3d9
PH
2098
2099/* The message body variables use malloc store. They may be set if this is
2100not the first message in an SMTP session and the previous message caused them
2101to be referenced in an ACL. */
2102
90341c71 2103if (message_body)
059ec3d9
PH
2104 {
2105 store_free(message_body);
2106 message_body = NULL;
2107 }
2108
90341c71 2109if (message_body_end)
059ec3d9
PH
2110 {
2111 store_free(message_body_end);
2112 message_body_end = NULL;
2113 }
2114
2115/* Warning log messages are also saved in malloc store. They are saved to avoid
2116repetition in the same message, but it seems right to repeat them for different
4e88a19f 2117messages. */
059ec3d9 2118
90341c71 2119while (acl_warn_logged)
059ec3d9
PH
2120 {
2121 string_item *this = acl_warn_logged;
2122 acl_warn_logged = acl_warn_logged->next;
2123 store_free(this);
2124 }
90341c71 2125store_reset(reset_point);
059ec3d9
PH
2126}
2127
2128
2129
2130
2131
2132/*************************************************
2133* Initialize for incoming batched SMTP message *
2134*************************************************/
2135
2136/* This function is called from smtp_setup_msg() in the case when
2137smtp_batched_input is true. This happens when -bS is used to pass a whole batch
2138of messages in one file with SMTP commands between them. All errors must be
2139reported by sending a message, and only MAIL FROM, RCPT TO, and DATA are
2140relevant. After an error on a sender, or an invalid recipient, the remainder
2141of the message is skipped. The value of received_protocol is already set.
2142
2143Argument: none
2144Returns: > 0 message successfully started (reached DATA)
2145 = 0 QUIT read or end of file reached
2146 < 0 should not occur
2147*/
2148
2149static int
2150smtp_setup_batch_msg(void)
2151{
2152int done = 0;
2153void *reset_point = store_get(0);
2154
2155/* Save the line count at the start of each transaction - single commands
2156like HELO and RSET count as whole transactions. */
2157
2158bsmtp_transaction_linecount = receive_linecount;
2159
2160if ((receive_feof)()) return 0; /* Treat EOF as QUIT */
2161
57cc2785 2162cancel_cutthrough_connection(TRUE, US"smtp_setup_batch_msg");
059ec3d9
PH
2163smtp_reset(reset_point); /* Reset for start of message */
2164
2165/* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
2166value. The values are 2 larger than the required yield of the function. */
2167
2168while (done <= 0)
2169 {
2170 uschar *errmess;
2171 uschar *recipient = NULL;
2172 int start, end, sender_domain, recipient_domain;
2173
bd8fbe36 2174 switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED))
059ec3d9
PH
2175 {
2176 /* The HELO/EHLO commands set sender_address_helo if they have
2177 valid data; otherwise they are ignored, except that they do
2178 a reset of the state. */
2179
2180 case HELO_CMD:
2181 case EHLO_CMD:
2182
db57e575
JH
2183 check_helo(smtp_cmd_data);
2184 /* Fall through */
059ec3d9
PH
2185
2186 case RSET_CMD:
db57e575
JH
2187 cancel_cutthrough_connection(TRUE, US"RSET received");
2188 smtp_reset(reset_point);
2189 bsmtp_transaction_linecount = receive_linecount;
2190 break;
059ec3d9
PH
2191
2192
2193 /* The MAIL FROM command requires an address as an operand. All we
2194 do here is to parse it for syntactic correctness. The form "<>" is
2195 a special case which converts into an empty string. The start/end
2196 pointers in the original are not used further for this address, as
2197 it is the canonical extracted address which is all that is kept. */
2198
2199 case MAIL_CMD:
db57e575
JH
2200 smtp_mailcmd_count++; /* Count for no-mail log */
2201 if (sender_address != NULL)
2202 /* The function moan_smtp_batch() does not return. */
2203 moan_smtp_batch(smtp_cmd_buffer, "503 Sender already given");
059ec3d9 2204
db57e575
JH
2205 if (smtp_cmd_data[0] == 0)
2206 /* The function moan_smtp_batch() does not return. */
2207 moan_smtp_batch(smtp_cmd_buffer, "501 MAIL FROM must have an address operand");
059ec3d9 2208
db57e575 2209 /* Reset to start of message */
059ec3d9 2210
db57e575
JH
2211 cancel_cutthrough_connection(TRUE, US"MAIL received");
2212 smtp_reset(reset_point);
059ec3d9 2213
db57e575 2214 /* Apply SMTP rewrite */
059ec3d9 2215
db57e575
JH
2216 raw_sender = ((rewrite_existflags & rewrite_smtp) != 0)?
2217 rewrite_one(smtp_cmd_data, rewrite_smtp|rewrite_smtp_sender, NULL, FALSE,
2218 US"", global_rewrite_rules) : smtp_cmd_data;
059ec3d9 2219
db57e575 2220 /* Extract the address; the TRUE flag allows <> as valid */
059ec3d9 2221
db57e575
JH
2222 raw_sender =
2223 parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain,
2224 TRUE);
059ec3d9 2225
db57e575
JH
2226 if (!raw_sender)
2227 /* The function moan_smtp_batch() does not return. */
2228 moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
059ec3d9 2229
db57e575 2230 sender_address = string_copy(raw_sender);
059ec3d9 2231
db57e575 2232 /* Qualify unqualified sender addresses if permitted to do so. */
059ec3d9 2233
db57e575
JH
2234 if ( !sender_domain
2235 && sender_address[0] != 0 && sender_address[0] != '@')
8768d548 2236 if (f.allow_unqualified_sender)
db57e575
JH
2237 {
2238 sender_address = rewrite_address_qualify(sender_address, FALSE);
2239 DEBUG(D_receive) debug_printf("unqualified address %s accepted "
2240 "and rewritten\n", raw_sender);
2241 }
2242 /* The function moan_smtp_batch() does not return. */
2243 else
2244 moan_smtp_batch(smtp_cmd_buffer, "501 sender address must contain "
2245 "a domain");
2246 break;
059ec3d9
PH
2247
2248
2249 /* The RCPT TO command requires an address as an operand. All we do
2250 here is to parse it for syntactic correctness. There may be any number
2251 of RCPT TO commands, specifying multiple senders. We build them all into
2252 a data structure that is in argc/argv format. The start/end values
2253 given by parse_extract_address are not used, as we keep only the
2254 extracted address. */
2255
2256 case RCPT_CMD:
db57e575
JH
2257 if (!sender_address)
2258 /* The function moan_smtp_batch() does not return. */
2259 moan_smtp_batch(smtp_cmd_buffer, "503 No sender yet given");
059ec3d9 2260
db57e575
JH
2261 if (smtp_cmd_data[0] == 0)
2262 /* The function moan_smtp_batch() does not return. */
2263 moan_smtp_batch(smtp_cmd_buffer,
2264 "501 RCPT TO must have an address operand");
059ec3d9 2265
db57e575 2266 /* Check maximum number allowed */
059ec3d9 2267
db57e575
JH
2268 if (recipients_max > 0 && recipients_count + 1 > recipients_max)
2269 /* The function moan_smtp_batch() does not return. */
2270 moan_smtp_batch(smtp_cmd_buffer, "%s too many recipients",
2271 recipients_max_reject? "552": "452");
059ec3d9 2272
db57e575
JH
2273 /* Apply SMTP rewrite, then extract address. Don't allow "<>" as a
2274 recipient address */
059ec3d9 2275
db57e575
JH
2276 recipient = rewrite_existflags & rewrite_smtp
2277 ? rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
2278 global_rewrite_rules)
2279 : smtp_cmd_data;
059ec3d9 2280
db57e575
JH
2281 recipient = parse_extract_address(recipient, &errmess, &start, &end,
2282 &recipient_domain, FALSE);
059ec3d9 2283
db57e575
JH
2284 if (!recipient)
2285 /* The function moan_smtp_batch() does not return. */
2286 moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
059ec3d9 2287
db57e575
JH
2288 /* If the recipient address is unqualified, qualify it if permitted. Then
2289 add it to the list of recipients. */
059ec3d9 2290
db57e575 2291 if (!recipient_domain)
8768d548 2292 if (f.allow_unqualified_recipient)
db57e575
JH
2293 {
2294 DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
2295 recipient);
2296 recipient = rewrite_address_qualify(recipient, TRUE);
2297 }
2298 /* The function moan_smtp_batch() does not return. */
2299 else
2300 moan_smtp_batch(smtp_cmd_buffer,
2301 "501 recipient address must contain a domain");
2302
2303 receive_add_recipient(recipient, -1);
2304 break;
059ec3d9
PH
2305
2306
2307 /* The DATA command is legal only if it follows successful MAIL FROM
2308 and RCPT TO commands. This function is complete when a valid DATA
2309 command is encountered. */
2310
2311 case DATA_CMD:
db57e575
JH
2312 if (!sender_address || recipients_count <= 0)
2313 /* The function moan_smtp_batch() does not return. */
2314 if (!sender_address)
2315 moan_smtp_batch(smtp_cmd_buffer,
2316 "503 MAIL FROM:<sender> command must precede DATA");
2317 else
2318 moan_smtp_batch(smtp_cmd_buffer,
2319 "503 RCPT TO:<recipient> must precede DATA");
059ec3d9 2320 else
db57e575
JH
2321 {
2322 done = 3; /* DATA successfully achieved */
2323 message_ended = END_NOTENDED; /* Indicate in middle of message */
2324 }
2325 break;
059ec3d9
PH
2326
2327
2328 /* The VRFY, EXPN, HELP, ETRN, and NOOP commands are ignored. */
2329
2330 case VRFY_CMD:
2331 case EXPN_CMD:
2332 case HELP_CMD:
2333 case NOOP_CMD:
2334 case ETRN_CMD:
db57e575
JH
2335 bsmtp_transaction_linecount = receive_linecount;
2336 break;
059ec3d9
PH
2337
2338
2339 case EOF_CMD:
2340 case QUIT_CMD:
db57e575
JH
2341 done = 2;
2342 break;
059ec3d9
PH
2343
2344
2345 case BADARG_CMD:
db57e575
JH
2346 /* The function moan_smtp_batch() does not return. */
2347 moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected argument data");
2348 break;
059ec3d9
PH
2349
2350
2351 case BADCHAR_CMD:
db57e575
JH
2352 /* The function moan_smtp_batch() does not return. */
2353 moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected NULL in SMTP command");
2354 break;
059ec3d9
PH
2355
2356
2357 default:
db57e575
JH
2358 /* The function moan_smtp_batch() does not return. */
2359 moan_smtp_batch(smtp_cmd_buffer, "500 Command unrecognized");
2360 break;
059ec3d9
PH
2361 }
2362 }
2363
2364return done - 2; /* Convert yield values */
2365}
2366
2367
2368
2369
cf0c6164
JH
2370static BOOL
2371smtp_log_tls_fail(uschar * errstr)
2372{
2373uschar * conn_info = smtp_get_connection_info();
2374
2375if (Ustrncmp(conn_info, US"SMTP ", 5) == 0) conn_info += 5;
2376/* I'd like to get separated H= here, but too hard for now */
2377
2378log_write(0, LOG_MAIN, "TLS error on %s %s", conn_info, errstr);
2379return FALSE;
2380}
2381
2382
a2673768
JH
2383
2384
2385#ifdef TCP_FASTOPEN
2386static void
2387tfo_in_check(void)
2388{
2389# ifdef TCP_INFO
2390struct tcp_info tinfo;
2391socklen_t len = sizeof(tinfo);
2392
2393if ( getsockopt(fileno(smtp_out), IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0
2394 && tinfo.tcpi_state == TCP_SYN_RECV
2395 )
2396 {
1ccd5f67 2397 DEBUG(D_receive) debug_printf("TCP_FASTOPEN mode connection (state TCP_SYN_RECV)\n");
8768d548 2398 f.tcp_in_fastopen = TRUE;
a2673768
JH
2399 }
2400# endif
2401}
2402#endif
2403
2404
059ec3d9
PH
2405/*************************************************
2406* Start an SMTP session *
2407*************************************************/
2408
2409/* This function is called at the start of an SMTP session. Thereafter,
2410smtp_setup_msg() is called to initiate each separate message. This
2411function does host-specific testing, and outputs the banner line.
2412
2413Arguments: none
2414Returns: FALSE if the session can not continue; something has
2415 gone wrong, or the connection to the host is blocked
2416*/
2417
2418BOOL
2419smtp_start_session(void)
2420{
acec9514 2421int esclen;
4e88a19f
PH
2422uschar *user_msg, *log_msg;
2423uschar *code, *esc;
acec9514
JH
2424uschar *p, *s;
2425gstring * ss;
059ec3d9 2426
0f1a8658 2427gettimeofday(&smtp_connection_start, NULL);
b4ed4da0
PH
2428for (smtp_ch_index = 0; smtp_ch_index < SMTP_HBUFF_SIZE; smtp_ch_index++)
2429 smtp_connection_had[smtp_ch_index] = SCH_NONE;
2430smtp_ch_index = 0;
2431
00f00ca5
PH
2432/* Default values for certain variables */
2433
88752192 2434fl.helo_seen = fl.esmtp = fl.helo_accept_junk = FALSE;
b4ed4da0 2435smtp_mailcmd_count = 0;
059ec3d9
PH
2436count_nonmail = TRUE_UNSET;
2437synprot_error_count = unknown_command_count = nonmail_command_count = 0;
2438smtp_delay_mail = smtp_rlm_base;
88752192 2439fl.auth_advertised = FALSE;
8768d548
JH
2440f.smtp_in_pipelining_advertised = f.smtp_in_pipelining_used = FALSE;
2441f.pipelining_enable = TRUE;
059ec3d9 2442sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING;
88752192 2443fl.smtp_exit_function_called = FALSE; /* For avoiding loop in not-quit exit */
059ec3d9 2444
33d73e3b
PH
2445/* If receiving by -bs from a trusted user, or testing with -bh, we allow
2446authentication settings from -oMaa to remain in force. */
2447
8768d548 2448if (!host_checking && !f.sender_host_notsocket)
c44ff8be 2449 sender_host_auth_pubname = sender_host_authenticated = NULL;
059ec3d9
PH
2450authenticated_by = NULL;
2451
2452#ifdef SUPPORT_TLS
817d9f57 2453tls_in.cipher = tls_in.peerdn = NULL;
9d1c15ef
JH
2454tls_in.ourcert = tls_in.peercert = NULL;
2455tls_in.sni = NULL;
44662487 2456tls_in.ocsp = OCSP_NOT_REQ;
88752192 2457fl.tls_advertised = FALSE;
8ac90765 2458# ifdef EXPERIMENTAL_REQUIRETLS
88752192 2459fl.requiretls_advertised = FALSE;
8ac90765 2460# endif
059ec3d9 2461#endif
88752192 2462fl.dsn_advertised = FALSE;
8c5d388a 2463#ifdef SUPPORT_I18N
88752192 2464fl.smtputf8_advertised = FALSE;
d1a13eea 2465#endif
059ec3d9
PH
2466
2467/* Reset ACL connection variables */
2468
38a0a95f 2469acl_var_c = NULL;
059ec3d9 2470
ca86f471 2471/* Allow for trailing 0 in the command and data buffers. */
3ee512ff 2472
bd8fbe36 2473if (!(smtp_cmd_buffer = US malloc(2*SMTP_CMD_BUFFER_SIZE + 2)))
059ec3d9
PH
2474 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2475 "malloc() failed for SMTP command buffer");
40c90bca 2476
2416c261 2477smtp_cmd_buffer[0] = 0;
bd8fbe36 2478smtp_data_buffer = smtp_cmd_buffer + SMTP_CMD_BUFFER_SIZE + 1;
059ec3d9
PH
2479
2480/* For batched input, the protocol setting can be overridden from the
2481command line by a trusted caller. */
2482
2483if (smtp_batched_input)
2484 {
40c90bca 2485 if (!received_protocol) received_protocol = US"local-bsmtp";
059ec3d9
PH
2486 }
2487
2488/* For non-batched SMTP input, the protocol setting is forced here. It will be
2489reset later if any of EHLO/AUTH/STARTTLS are received. */
2490
2491else
2492 received_protocol =
e524074d 2493 (sender_host_address ? protocols : protocols_local) [pnormal];
059ec3d9
PH
2494
2495/* Set up the buffer for inputting using direct read() calls, and arrange to
ecce6d9a
JH
2496call the local functions instead of the standard C ones. Place a NUL at the
2497end of the buffer to safety-stop C-string reads from it. */
059ec3d9 2498
5903c6ff 2499if (!(smtp_inbuffer = US malloc(IN_BUFFER_SIZE)))
059ec3d9 2500 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "malloc() failed for SMTP input buffer");
ecce6d9a 2501smtp_inbuffer[IN_BUFFER_SIZE-1] = '\0';
40c90bca 2502
059ec3d9 2503receive_getc = smtp_getc;
0d81dabc 2504receive_getbuf = smtp_getbuf;
584e96c6 2505receive_get_cache = smtp_get_cache;
059ec3d9
PH
2506receive_ungetc = smtp_ungetc;
2507receive_feof = smtp_feof;
2508receive_ferror = smtp_ferror;
58eb016e 2509receive_smtp_buffered = smtp_buffered;
059ec3d9
PH
2510smtp_inptr = smtp_inend = smtp_inbuffer;
2511smtp_had_eof = smtp_had_error = 0;
2512
2513/* Set up the message size limit; this may be host-specific */
2514
d45b1de8 2515thismessage_size_limit = expand_string_integer(message_size_limit, TRUE);
db57e575 2516if (expand_string_message)
059ec3d9
PH
2517 {
2518 if (thismessage_size_limit == -1)
2519 log_write(0, LOG_MAIN|LOG_PANIC, "unable to expand message_size_limit: "
2520 "%s", expand_string_message);
2521 else
2522 log_write(0, LOG_MAIN|LOG_PANIC, "invalid message_size_limit: "
2523 "%s", expand_string_message);
2524 smtp_closedown(US"Temporary local problem - please try later");
2525 return FALSE;
2526 }
2527
2528/* When a message is input locally via the -bs or -bS options, sender_host_
2529unknown is set unless -oMa was used to force an IP address, in which case it
2530is checked like a real remote connection. When -bs is used from inetd, this
2531flag is not set, causing the sending host to be checked. The code that deals
2532with IP source routing (if configured) is never required for -bs or -bS and
2533the flag sender_host_notsocket is used to suppress it.
2534
2535If smtp_accept_max and smtp_accept_reserve are set, keep some connections in
2536reserve for certain hosts and/or networks. */
2537
8768d548 2538if (!f.sender_host_unknown)
059ec3d9
PH
2539 {
2540 int rc;
2541 BOOL reserved_host = FALSE;
2542
2543 /* Look up IP options (source routing info) on the socket if this is not an
2544 -oMa "host", and if any are found, log them and drop the connection.
2545
2546 Linux (and others now, see below) is different to everyone else, so there
2547 has to be some conditional compilation here. Versions of Linux before 2.1.15
2548 used a structure whose name was "options". Somebody finally realized that
2549 this name was silly, and it got changed to "ip_options". I use the
2550 newer name here, but there is a fudge in the script that sets up os.h
2551 to define a macro in older Linux systems.
2552
2553 Sigh. Linux is a fast-moving target. Another generation of Linux uses
2554 glibc 2, which has chosen ip_opts for the structure name. This is now
2555 really a glibc thing rather than a Linux thing, so the condition name
2556 has been changed to reflect this. It is relevant also to GNU/Hurd.
2557
2558 Mac OS 10.x (Darwin) is like the later glibc versions, but without the
2559 setting of the __GLIBC__ macro, so we can't detect it automatically. There's
2560 a special macro defined in the os.h file.
2561
2562 Some DGUX versions on older hardware appear not to support IP options at
2563 all, so there is now a general macro which can be set to cut out this
2564 support altogether.
2565
2566 How to do this properly in IPv6 is not yet known. */
2567
e0574cb5 2568#if !HAVE_IPV6 && !defined(NO_IP_OPTIONS)
059ec3d9
PH
2569
2570 #ifdef GLIBC_IP_OPTIONS
2571 #if (!defined __GLIBC__) || (__GLIBC__ < 2)
2572 #define OPTSTYLE 1
2573 #else
2574 #define OPTSTYLE 2
2575 #endif
2576 #elif defined DARWIN_IP_OPTIONS
2577 #define OPTSTYLE 2
2578 #else
2579 #define OPTSTYLE 3
2580 #endif
2581
8768d548 2582 if (!host_checking && !f.sender_host_notsocket)
059ec3d9
PH
2583 {
2584 #if OPTSTYLE == 1
36a3b041 2585 EXIM_SOCKLEN_T optlen = sizeof(struct ip_options) + MAX_IPOPTLEN;
059ec3d9
PH
2586 struct ip_options *ipopt = store_get(optlen);
2587 #elif OPTSTYLE == 2
2588 struct ip_opts ipoptblock;
2589 struct ip_opts *ipopt = &ipoptblock;
36a3b041 2590 EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
059ec3d9
PH
2591 #else
2592 struct ipoption ipoptblock;
2593 struct ipoption *ipopt = &ipoptblock;
36a3b041 2594 EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
059ec3d9
PH
2595 #endif
2596
2597 /* Occasional genuine failures of getsockopt() have been seen - for
2598 example, "reset by peer". Therefore, just log and give up on this
2599 call, unless the error is ENOPROTOOPT. This error is given by systems
2600 that have the interfaces but not the mechanism - e.g. GNU/Hurd at the time
2601 of writing. So for that error, carry on - we just can't do an IP options
2602 check. */
2603
2604 DEBUG(D_receive) debug_printf("checking for IP options\n");
2605
5903c6ff 2606 if (getsockopt(fileno(smtp_out), IPPROTO_IP, IP_OPTIONS, US (ipopt),
059ec3d9
PH
2607 &optlen) < 0)
2608 {
2609 if (errno != ENOPROTOOPT)
2610 {
2611 log_write(0, LOG_MAIN, "getsockopt() failed from %s: %s",
2612 host_and_ident(FALSE), strerror(errno));
925ac8e4 2613 smtp_printf("451 SMTP service not available\r\n", FALSE);
059ec3d9
PH
2614 return FALSE;
2615 }
2616 }
2617
2618 /* Deal with any IP options that are set. On the systems I have looked at,
2619 the value of MAX_IPOPTLEN has been 40, meaning that there should never be
2620 more logging data than will fit in big_buffer. Nevertheless, after somebody
2621 questioned this code, I've added in some paranoid checking. */
2622
2623 else if (optlen > 0)
2624 {
2625 uschar *p = big_buffer;
2626 uschar *pend = big_buffer + big_buffer_size;
2627 uschar *opt, *adptr;
2628 int optcount;
2629 struct in_addr addr;
2630
2631 #if OPTSTYLE == 1
5903c6ff 2632 uschar *optstart = US (ipopt->__data);
059ec3d9 2633 #elif OPTSTYLE == 2
5903c6ff 2634 uschar *optstart = US (ipopt->ip_opts);
059ec3d9 2635 #else
5903c6ff 2636 uschar *optstart = US (ipopt->ipopt_list);
059ec3d9
PH
2637 #endif
2638
2639 DEBUG(D_receive) debug_printf("IP options exist\n");
2640
2641 Ustrcpy(p, "IP options on incoming call:");
2642 p += Ustrlen(p);
2643
2644 for (opt = optstart; opt != NULL &&
5903c6ff 2645 opt < US (ipopt) + optlen;)
059ec3d9
PH
2646 {
2647 switch (*opt)
2648 {
2649 case IPOPT_EOL:
2650 opt = NULL;
2651 break;
2652
2653 case IPOPT_NOP:
2654 opt++;
2655 break;
2656
2657 case IPOPT_SSRR:
2658 case IPOPT_LSRR:
2659 if (!string_format(p, pend-p, " %s [@%s",
2660 (*opt == IPOPT_SSRR)? "SSRR" : "LSRR",
2661 #if OPTSTYLE == 1
2662 inet_ntoa(*((struct in_addr *)(&(ipopt->faddr))))))
2663 #elif OPTSTYLE == 2
2664 inet_ntoa(ipopt->ip_dst)))
2665 #else
2666 inet_ntoa(ipopt->ipopt_dst)))
2667 #endif
2668 {
2669 opt = NULL;
2670 break;
2671 }
2672
2673 p += Ustrlen(p);
2674 optcount = (opt[1] - 3) / sizeof(struct in_addr);
2675 adptr = opt + 3;
2676 while (optcount-- > 0)
2677 {
2678 memcpy(&addr, adptr, sizeof(addr));
2679 if (!string_format(p, pend - p - 1, "%s%s",
2680 (optcount == 0)? ":" : "@", inet_ntoa(addr)))
2681 {
2682 opt = NULL;
2683 break;
2684 }
2685 p += Ustrlen(p);
2686 adptr += sizeof(struct in_addr);
2687 }
2688 *p++ = ']';
2689 opt += opt[1];
2690 break;
2691
2692 default:
2693 {
2694 int i;
2695 if (pend - p < 4 + 3*opt[1]) { opt = NULL; break; }
2696 Ustrcat(p, "[ ");
2697 p += 2;
2698 for (i = 0; i < opt[1]; i++)
5976eb99 2699 p += sprintf(CS p, "%2.2x ", opt[i]);
059ec3d9
PH
2700 *p++ = ']';
2701 }
2702 opt += opt[1];
2703 break;
2704 }
2705 }
2706
2707 *p = 0;
2708 log_write(0, LOG_MAIN, "%s", big_buffer);
2709
2710 /* Refuse any call with IP options. This is what tcpwrappers 7.5 does. */
2711
2712 log_write(0, LOG_MAIN|LOG_REJECT,
2713 "connection from %s refused (IP options)", host_and_ident(FALSE));
2714
925ac8e4 2715 smtp_printf("554 SMTP service not available\r\n", FALSE);
059ec3d9
PH
2716 return FALSE;
2717 }
2718
2719 /* Length of options = 0 => there are no options */
2720
2721 else DEBUG(D_receive) debug_printf("no IP options found\n");
2722 }
e0574cb5 2723#endif /* HAVE_IPV6 && !defined(NO_IP_OPTIONS) */
059ec3d9
PH
2724
2725 /* Set keep-alive in socket options. The option is on by default. This
2726 setting is an attempt to get rid of some hanging connections that stick in
2727 read() when the remote end (usually a dialup) goes away. */
2728
8768d548 2729 if (smtp_accept_keepalive && !f.sender_host_notsocket)
059ec3d9
PH
2730 ip_keepalive(fileno(smtp_out), sender_host_address, FALSE);
2731
2732 /* If the current host matches host_lookup, set the name by doing a
2733 reverse lookup. On failure, sender_host_name will be NULL and
2734 host_lookup_failed will be TRUE. This may or may not be serious - optional
2735 checks later. */
2736
2737 if (verify_check_host(&host_lookup) == OK)
2738 {
2739 (void)host_name_lookup();
2740 host_build_sender_fullhost();
2741 }
2742
2743 /* Delay this until we have the full name, if it is looked up. */
2744
2745 set_process_info("handling incoming connection from %s",
2746 host_and_ident(FALSE));
2747
1ad6489e
JH
2748 /* Expand smtp_receive_timeout, if needed */
2749
2750 if (smtp_receive_timeout_s)
2751 {
2752 uschar * exp;
2753 if ( !(exp = expand_string(smtp_receive_timeout_s))
2754 || !(*exp)
2755 || (smtp_receive_timeout = readconf_readtime(exp, 0, FALSE)) < 0
2756 )
2757 log_write(0, LOG_MAIN|LOG_PANIC,
2758 "bad value for smtp_receive_timeout: '%s'", exp ? exp : US"");
2759 }
2760
059ec3d9
PH
2761 /* Test for explicit connection rejection */
2762
2763 if (verify_check_host(&host_reject_connection) == OK)
2764 {
2765 log_write(L_connection_reject, LOG_MAIN|LOG_REJECT, "refused connection "
2766 "from %s (host_reject_connection)", host_and_ident(FALSE));
925ac8e4 2767 smtp_printf("554 SMTP service not available\r\n", FALSE);
059ec3d9
PH
2768 return FALSE;
2769 }
2770
afb3eaaf
PH
2771 /* Test with TCP Wrappers if so configured. There is a problem in that
2772 hosts_ctl() returns 0 (deny) under a number of system failure circumstances,
2773 such as disks dying. In these cases, it is desirable to reject with a 4xx
2774 error instead of a 5xx error. There isn't a "right" way to detect such
2775 problems. The following kludge is used: errno is zeroed before calling
2776 hosts_ctl(). If the result is "reject", a 5xx error is given only if the
2777 value of errno is 0 or ENOENT (which happens if /etc/hosts.{allow,deny} does
2778 not exist). */
059ec3d9 2779
1811cb4c 2780#ifdef USE_TCP_WRAPPERS
afb3eaaf 2781 errno = 0;
1811cb4c 2782 if (!(tcp_wrappers_name = expand_string(tcp_wrappers_daemon_name)))
5dc43717
JJ
2783 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" "
2784 "(tcp_wrappers_name) failed: %s", string_printing(tcp_wrappers_name),
2785 expand_string_message);
1811cb4c 2786
5dc43717 2787 if (!hosts_ctl(tcp_wrappers_name,
1811cb4c
JH
2788 sender_host_name ? CS sender_host_name : STRING_UNKNOWN,
2789 sender_host_address ? CS sender_host_address : STRING_UNKNOWN,
2790 sender_ident ? CS sender_ident : STRING_UNKNOWN))
059ec3d9 2791 {
afb3eaaf
PH
2792 if (errno == 0 || errno == ENOENT)
2793 {
2794 HDEBUG(D_receive) debug_printf("tcp wrappers rejection\n");
2795 log_write(L_connection_reject,
2796 LOG_MAIN|LOG_REJECT, "refused connection from %s "
2797 "(tcp wrappers)", host_and_ident(FALSE));
925ac8e4 2798 smtp_printf("554 SMTP service not available\r\n", FALSE);
afb3eaaf
PH
2799 }
2800 else
2801 {
2802 int save_errno = errno;
2803 HDEBUG(D_receive) debug_printf("tcp wrappers rejected with unexpected "
2804 "errno value %d\n", save_errno);
2805 log_write(L_connection_reject,
2806 LOG_MAIN|LOG_REJECT, "temporarily refused connection from %s "
2807 "(tcp wrappers errno=%d)", host_and_ident(FALSE), save_errno);
925ac8e4 2808 smtp_printf("451 Temporary local problem - please try later\r\n", FALSE);
afb3eaaf 2809 }
059ec3d9
PH
2810 return FALSE;
2811 }
1811cb4c 2812#endif
059ec3d9 2813
b01dd148
PH
2814 /* Check for reserved slots. The value of smtp_accept_count has already been
2815 incremented to include this process. */
059ec3d9
PH
2816
2817 if (smtp_accept_max > 0 &&
b01dd148 2818 smtp_accept_count > smtp_accept_max - smtp_accept_reserve)
059ec3d9
PH
2819 {
2820 if ((rc = verify_check_host(&smtp_reserve_hosts)) != OK)
2821 {
2822 log_write(L_connection_reject,
2823 LOG_MAIN, "temporarily refused connection from %s: not in "
2824 "reserve list: connected=%d max=%d reserve=%d%s",
b01dd148 2825 host_and_ident(FALSE), smtp_accept_count - 1, smtp_accept_max,
059ec3d9
PH
2826 smtp_accept_reserve, (rc == DEFER)? " (lookup deferred)" : "");
2827 smtp_printf("421 %s: Too many concurrent SMTP connections; "
925ac8e4 2828 "please try again later\r\n", FALSE, smtp_active_hostname);
059ec3d9
PH
2829 return FALSE;
2830 }
2831 reserved_host = TRUE;
2832 }
2833
2834 /* If a load level above which only messages from reserved hosts are
2835 accepted is set, check the load. For incoming calls via the daemon, the
2836 check is done in the superior process if there are no reserved hosts, to
2837 save a fork. In all cases, the load average will already be available
2838 in a global variable at this point. */
2839
2840 if (smtp_load_reserve >= 0 &&
2841 load_average > smtp_load_reserve &&
2842 !reserved_host &&
2843 verify_check_host(&smtp_reserve_hosts) != OK)
2844 {
2845 log_write(L_connection_reject,
2846 LOG_MAIN, "temporarily refused connection from %s: not in "
2847 "reserve list and load average = %.2f", host_and_ident(FALSE),
2848 (double)load_average/1000.0);
925ac8e4 2849 smtp_printf("421 %s: Too much load; please try again later\r\n", FALSE,
059ec3d9
PH
2850 smtp_active_hostname);
2851 return FALSE;
2852 }
2853
2854 /* Determine whether unqualified senders or recipients are permitted
2855 for this host. Unfortunately, we have to do this every time, in order to
2856 set the flags so that they can be inspected when considering qualifying
2857 addresses in the headers. For a site that permits no qualification, this
2858 won't take long, however. */
2859
8768d548 2860 f.allow_unqualified_sender =
059ec3d9
PH
2861 verify_check_host(&sender_unqualified_hosts) == OK;
2862
8768d548 2863 f.allow_unqualified_recipient =
059ec3d9
PH
2864 verify_check_host(&recipient_unqualified_hosts) == OK;
2865
2866 /* Determine whether HELO/EHLO is required for this host. The requirement
2867 can be hard or soft. */
2868
88752192
JH
2869 fl.helo_required = verify_check_host(&helo_verify_hosts) == OK;
2870 if (!fl.helo_required)
2871 fl.helo_verify = verify_check_host(&helo_try_verify_hosts) == OK;
059ec3d9
PH
2872
2873 /* Determine whether this hosts is permitted to send syntactic junk
2874 after a HELO or EHLO command. */
2875
88752192 2876 fl.helo_accept_junk = verify_check_host(&helo_accept_junk_hosts) == OK;
059ec3d9
PH
2877 }
2878
2879/* For batch SMTP input we are now done. */
2880
2881if (smtp_batched_input) return TRUE;
2882
a3c86431
TL
2883/* If valid Proxy Protocol source is connecting, set up session.
2884 * Failure will not allow any SMTP function other than QUIT. */
1811cb4c
JH
2885
2886#ifdef SUPPORT_PROXY
a3c86431 2887proxy_session = FALSE;
8768d548 2888f.proxy_session_failed = FALSE;
a3c86431 2889if (check_proxy_protocol_host())
1811cb4c
JH
2890 setup_proxy_protocol_host();
2891#endif
2892
2893 /* Start up TLS if tls_on_connect is set. This is for supporting the legacy
2894 smtps port for use with older style SSL MTAs. */
2895
2896#ifdef SUPPORT_TLS
69d8eed7
JH
2897 if (tls_in.on_connect)
2898 {
2899 if (tls_server_start(tls_require_ciphers, &user_msg) != OK)
2900 return smtp_log_tls_fail(user_msg);
2901 cmd_list[CMD_LIST_TLS_AUTH].is_mail_cmd = TRUE;
2902 }
a3c86431
TL
2903#endif
2904
1811cb4c 2905/* Run the connect ACL if it exists */
059ec3d9 2906
4e88a19f 2907user_msg = NULL;
3cc3f762 2908if (acl_smtp_connect)
059ec3d9
PH
2909 {
2910 int rc;
3cc3f762
JH
2911 if ((rc = acl_check(ACL_WHERE_CONNECT, NULL, acl_smtp_connect, &user_msg,
2912 &log_msg)) != OK)
059ec3d9 2913 {
3cc3f762 2914 (void) smtp_handle_acl_fail(ACL_WHERE_CONNECT, rc, user_msg, log_msg);
059ec3d9
PH
2915 return FALSE;
2916 }
2917 }
2918
2919/* Output the initial message for a two-way SMTP connection. It may contain
2920newlines, which then cause a multi-line response to be given. */
2921
4e88a19f
PH
2922code = US"220"; /* Default status code */
2923esc = US""; /* Default extended status code */
2924esclen = 0; /* Length of esc */
2925
d4ff61d1 2926if (!user_msg)
4e88a19f 2927 {
d4ff61d1 2928 if (!(s = expand_string(smtp_banner)))
4e88a19f
PH
2929 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" (smtp_banner) "
2930 "failed: %s", smtp_banner, expand_string_message);
2931 }
2932else
2933 {
2934 int codelen = 3;
2935 s = user_msg;
4f6ae5c3 2936 smtp_message_code(&code, &codelen, &s, NULL, TRUE);
d6a96edc 2937 if (codelen > 4)
4e88a19f
PH
2938 {
2939 esc = code + 4;
2940 esclen = codelen - 4;
2941 }
2942 }
059ec3d9
PH
2943
2944/* Remove any terminating newlines; might as well remove trailing space too */
2945
2946p = s + Ustrlen(s);
2947while (p > s && isspace(p[-1])) p--;
2948*p = 0;
2949
2950/* It seems that CC:Mail is braindead, and assumes that the greeting message
2951is all contained in a single IP packet. The original code wrote out the
2952greeting using several calls to fprint/fputc, and on busy servers this could
2953cause it to be split over more than one packet - which caused CC:Mail to fall
2954over when it got the second part of the greeting after sending its first
2955command. Sigh. To try to avoid this, build the complete greeting message
2956first, and output it in one fell swoop. This gives a better chance of it
2957ending up as a single packet. */
2958
acec9514 2959ss = string_get(256);
059ec3d9
PH
2960
2961p = s;
2962do /* At least once, in case we have an empty string */
2963 {
2964 int len;
2965 uschar *linebreak = Ustrchr(p, '\n');
acec9514 2966 ss = string_catn(ss, code, 3);
db57e575 2967 if (!linebreak)
059ec3d9
PH
2968 {
2969 len = Ustrlen(p);
acec9514 2970 ss = string_catn(ss, US" ", 1);
059ec3d9
PH
2971 }
2972 else
2973 {
2974 len = linebreak - p;
acec9514 2975 ss = string_catn(ss, US"-", 1);
059ec3d9 2976 }
acec9514
JH
2977 ss = string_catn(ss, esc, esclen);
2978 ss = string_catn(ss, p, len);
2979 ss = string_catn(ss, US"\r\n", 2);
059ec3d9 2980 p += len;
db57e575 2981 if (linebreak) p++;
059ec3d9 2982 }
db57e575 2983while (*p);
059ec3d9 2984
059ec3d9
PH
2985/* Before we write the banner, check that there is no input pending, unless
2986this synchronisation check is disabled. */
2987
a14e5636 2988if (!check_sync())
059ec3d9 2989 {
40525d07
JH
2990 unsigned n = smtp_inend - smtp_inptr;
2991 if (n > 32) n = 32;
2992
a14e5636
PH
2993 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol "
2994 "synchronization error (input sent without waiting for greeting): "
2995 "rejected connection from %s input=\"%s\"", host_and_ident(TRUE),
40525d07 2996 string_printing(string_copyn(smtp_inptr, n)));
925ac8e4 2997 smtp_printf("554 SMTP synchronization error\r\n", FALSE);
a14e5636 2998 return FALSE;
059ec3d9
PH
2999 }
3000
3001/* Now output the banner */
3002
acec9514 3003smtp_printf("%s", FALSE, string_from_gstring(ss));
a2673768
JH
3004
3005/* Attempt to see if we sent the banner before the last ACK of the 3-way
3006handshake arrived. If so we must have managed a TFO. */
3007
3008#ifdef TCP_FASTOPEN
3009tfo_in_check();
3010#endif
3011
059ec3d9
PH
3012return TRUE;
3013}
3014
3015
3016
3017
3018
3019/*************************************************
3020* Handle SMTP syntax and protocol errors *
3021*************************************************/
3022
3023/* Write to the log for SMTP syntax errors in incoming commands, if configured
3024to do so. Then transmit the error response. The return value depends on the
3025number of syntax and protocol errors in this SMTP session.
3026
3027Arguments:
3028 type error type, given as a log flag bit
3029 code response code; <= 0 means don't send a response
3030 data data to reflect in the response (can be NULL)
3031 errmess the error message
3032
3033Returns: -1 limit of syntax/protocol errors NOT exceeded
3034 +1 limit of syntax/protocol errors IS exceeded
3035
3036These values fit in with the values of the "done" variable in the main
3037processing loop in smtp_setup_msg(). */
3038
3039static int
3040synprot_error(int type, int code, uschar *data, uschar *errmess)
3041{
3042int yield = -1;
3043
3044log_write(type, LOG_MAIN, "SMTP %s error in \"%s\" %s %s",
3045 (type == L_smtp_syntax_error)? "syntax" : "protocol",
3ee512ff 3046 string_printing(smtp_cmd_buffer), host_and_ident(TRUE), errmess);
059ec3d9
PH
3047
3048if (++synprot_error_count > smtp_max_synprot_errors)
3049 {
3050 yield = 1;
3051 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
3052 "syntax or protocol errors (last command was \"%s\")",
0ebc4d69 3053 host_and_ident(FALSE), string_printing(smtp_cmd_buffer));
059ec3d9
PH
3054 }
3055
3056if (code > 0)
3057 {
925ac8e4
JH
3058 smtp_printf("%d%c%s%s%s\r\n", FALSE, code, yield == 1 ? '-' : ' ',
3059 data ? data : US"", data ? US": " : US"", errmess);
059ec3d9 3060 if (yield == 1)
925ac8e4 3061 smtp_printf("%d Too many syntax or protocol errors\r\n", FALSE, code);
059ec3d9
PH
3062 }
3063
3064return yield;
3065}
3066
3067
3068
3069
3070/*************************************************
059ec3d9
PH
3071* Send SMTP response, possibly multiline *
3072*************************************************/
3073
3074/* There are, it seems, broken clients out there that cannot handle multiline
3075responses. If no_multiline_responses is TRUE (it can be set from an ACL), we
3076output nothing for non-final calls, and only the first line for anything else.
3077
3078Arguments:
a5bd321b 3079 code SMTP code, may involve extended status codes
d6a96edc 3080 codelen length of smtp code; if > 4 there's an ESC
059ec3d9
PH
3081 final FALSE if the last line isn't the final line
3082 msg message text, possibly containing newlines
3083
3084Returns: nothing
3085*/
3086
3087void
a5bd321b 3088smtp_respond(uschar* code, int codelen, BOOL final, uschar *msg)
059ec3d9 3089{
a5bd321b
PH
3090int esclen = 0;
3091uschar *esc = US"";
3092
8768d548 3093if (!final && f.no_multiline_responses) return;
059ec3d9 3094
d6a96edc 3095if (codelen > 4)
a5bd321b
PH
3096 {
3097 esc = code + 4;
3098 esclen = codelen - 4;
3099 }
3100
2679d413
PH
3101/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
3102have had the same. Note: this code is also present in smtp_printf(). It would
3103be tidier to have it only in one place, but when it was added, it was easier to
3104do it that way, so as not to have to mess with the code for the RCPT command,
3105which sometimes uses smtp_printf() and sometimes smtp_respond(). */
3106
88752192 3107if (fl.rcpt_in_progress)
2679d413
PH
3108 {
3109 if (rcpt_smtp_response == NULL)
3110 rcpt_smtp_response = string_copy(msg);
88752192 3111 else if (fl.rcpt_smtp_response_same &&
2679d413 3112 Ustrcmp(rcpt_smtp_response, msg) != 0)
88752192
JH
3113 fl.rcpt_smtp_response_same = FALSE;
3114 fl.rcpt_in_progress = FALSE;
2679d413
PH
3115 }
3116
e5de01f0 3117/* Now output the message, splitting it up into multiple lines if necessary.
925ac8e4
JH
3118We only handle pipelining these responses as far as nonfinal/final groups,
3119not the whole MAIL/RCPT/DATA response set. */
2679d413 3120
059ec3d9
PH
3121for (;;)
3122 {
3123 uschar *nl = Ustrchr(msg, '\n');
3124 if (nl == NULL)
3125 {
925ac8e4 3126 smtp_printf("%.3s%c%.*s%s\r\n", !final, code, final ? ' ':'-', esclen, esc, msg);
059ec3d9
PH
3127 return;
3128 }
8768d548 3129 else if (nl[1] == 0 || f.no_multiline_responses)
059ec3d9 3130 {
925ac8e4 3131 smtp_printf("%.3s%c%.*s%.*s\r\n", !final, code, final ? ' ':'-', esclen, esc,
a5bd321b 3132 (int)(nl - msg), msg);
059ec3d9
PH
3133 return;
3134 }
3135 else
3136 {
925ac8e4 3137 smtp_printf("%.3s-%.*s%.*s\r\n", TRUE, code, esclen, esc, (int)(nl - msg), msg);
059ec3d9
PH
3138 msg = nl + 1;
3139 while (isspace(*msg)) msg++;
3140 }
3141 }
3142}
3143
3144
3145
3146
3147/*************************************************
4e88a19f
PH
3148* Parse user SMTP message *
3149*************************************************/
3150
3151/* This function allows for user messages overriding the response code details
3152by providing a suitable response code string at the start of the message
3153user_msg. Check the message for starting with a response code and optionally an
3154extended status code. If found, check that the first digit is valid, and if so,
3155change the code pointer and length to use the replacement. An invalid code
3156causes a panic log; in this case, if the log messages is the same as the user
3157message, we must also adjust the value of the log message to show the code that
3158is actually going to be used (the original one).
3159
3160This function is global because it is called from receive.c as well as within
3161this module.
3162
d6a96edc
PH
3163Note that the code length returned includes the terminating whitespace
3164character, which is always included in the regex match.
3165
4e88a19f
PH
3166Arguments:
3167 code SMTP code, may involve extended status codes
d6a96edc 3168 codelen length of smtp code; if > 4 there's an ESC
4e88a19f
PH
3169 msg message text
3170 log_msg optional log message, to be adjusted with the new SMTP code
4f6ae5c3 3171 check_valid if true, verify the response code
4e88a19f
PH
3172
3173Returns: nothing
3174*/
3175
3176void
4f6ae5c3
JH
3177smtp_message_code(uschar **code, int *codelen, uschar **msg, uschar **log_msg,
3178 BOOL check_valid)
4e88a19f
PH
3179{
3180int n;
3181int ovector[3];
3182
4f6ae5c3 3183if (!msg || !*msg) return;
4e88a19f 3184
4f6ae5c3
JH
3185if ((n = pcre_exec(regex_smtp_code, NULL, CS *msg, Ustrlen(*msg), 0,
3186 PCRE_EOPT, ovector, sizeof(ovector)/sizeof(int))) < 0) return;
4e88a19f 3187
4f6ae5c3 3188if (check_valid && (*msg)[0] != (*code)[0])
4e88a19f
PH
3189 {
3190 log_write(0, LOG_MAIN|LOG_PANIC, "configured error code starts with "
3191 "incorrect digit (expected %c) in \"%s\"", (*code)[0], *msg);
3192 if (log_msg != NULL && *log_msg == *msg)
3193 *log_msg = string_sprintf("%s %s", *code, *log_msg + ovector[1]);
3194 }
3195else
3196 {
3197 *code = *msg;
3198 *codelen = ovector[1]; /* Includes final space */
3199 }
3200*msg += ovector[1]; /* Chop the code off the message */
3201return;
3202}
3203
3204
3205
3206
3207/*************************************************
059ec3d9
PH
3208* Handle an ACL failure *
3209*************************************************/
3210
3211/* This function is called when acl_check() fails. As well as calls from within
3212this module, it is called from receive.c for an ACL after DATA. It sorts out
5b6f7658 3213logging the incident, and sends the error response. A message containing
059ec3d9
PH
3214newlines is turned into a multiline SMTP response, but for logging, only the
3215first line is used.
3216
a5bd321b
PH
3217There's a table of default permanent failure response codes to use in
3218globals.c, along with the table of names. VFRY is special. Despite RFC1123 it
3219defaults disabled in Exim. However, discussion in connection with RFC 821bis
3220(aka RFC 2821) has concluded that the response should be 252 in the disabled
3221state, because there are broken clients that try VRFY before RCPT. A 5xx
3222response should be given only when the address is positively known to be
4f6ae5c3
JH
3223undeliverable. Sigh. We return 252 if there is no VRFY ACL or it provides
3224no explicit code, but if there is one we let it know best.
3225Also, for ETRN, 458 is given on refusal, and for AUTH, 503.
a5bd321b
PH
3226
3227From Exim 4.63, it is possible to override the response code details by
3228providing a suitable response code string at the start of the message provided
3229in user_msg. The code's first digit is checked for validity.
059ec3d9
PH
3230
3231Arguments:
4f6ae5c3
JH
3232 where where the ACL was called from
3233 rc the failure code
3234 user_msg a message that can be included in an SMTP response
3235 log_msg a message for logging
059ec3d9
PH
3236
3237Returns: 0 in most cases
3238 2 if the failure code was FAIL_DROP, in which case the
3239 SMTP connection should be dropped (this value fits with the
3240 "done" variable in smtp_setup_msg() below)
3241*/
3242
3243int
3244smtp_handle_acl_fail(int where, int rc, uschar *user_msg, uschar *log_msg)
3245{
059ec3d9 3246BOOL drop = rc == FAIL_DROP;
a5bd321b 3247int codelen = 3;
a5bd321b 3248uschar *smtp_code;
059ec3d9
PH
3249uschar *lognl;
3250uschar *sender_info = US"";
64ffc24f 3251uschar *what =
8523533c 3252#ifdef WITH_CONTENT_SCAN
3cc3f762 3253 where == ACL_WHERE_MIME ? US"during MIME ACL checks" :
8e669ac1 3254#endif
3cc3f762
JH
3255 where == ACL_WHERE_PREDATA ? US"DATA" :
3256 where == ACL_WHERE_DATA ? US"after DATA" :
8ccd00b1 3257#ifndef DISABLE_PRDR
3cc3f762 3258 where == ACL_WHERE_PRDR ? US"after DATA PRDR" :
fd98a5c6 3259#endif
3cc3f762
JH
3260 smtp_cmd_data ?
3261 string_sprintf("%s %s", acl_wherenames[where], smtp_cmd_data) :
3262 string_sprintf("%s in \"connect\" ACL", acl_wherenames[where]);
059ec3d9
PH
3263
3264if (drop) rc = FAIL;
3265
4e88a19f 3266/* Set the default SMTP code, and allow a user message to change it. */
a5bd321b 3267
4f6ae5c3
JH
3268smtp_code = rc == FAIL ? acl_wherecodes[where] : US"451";
3269smtp_message_code(&smtp_code, &codelen, &user_msg, &log_msg,
3270 where != ACL_WHERE_VRFY);
a5bd321b 3271
059ec3d9
PH
3272/* We used to have sender_address here; however, there was a bug that was not
3273updating sender_address after a rewrite during a verify. When this bug was
3274fixed, sender_address at this point became the rewritten address. I'm not sure
3275this is what should be logged, so I've changed to logging the unrewritten
3276address to retain backward compatibility. */
3277
8523533c 3278#ifndef WITH_CONTENT_SCAN
059ec3d9 3279if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA)
8523533c
TK
3280#else
3281if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA || where == ACL_WHERE_MIME)
3282#endif
059ec3d9 3283 {
b98bb9ac
PP
3284 sender_info = string_sprintf("F=<%s>%s%s%s%s ",
3285 sender_address_unrewritten ? sender_address_unrewritten : sender_address,
3286 sender_host_authenticated ? US" A=" : US"",
3287 sender_host_authenticated ? sender_host_authenticated : US"",
3288 sender_host_authenticated && authenticated_id ? US":" : US"",
3289 sender_host_authenticated && authenticated_id ? authenticated_id : US""
3290 );
059ec3d9
PH
3291 }
3292
3293/* If there's been a sender verification failure with a specific message, and
3294we have not sent a response about it yet, do so now, as a preliminary line for
278c6e6c
PH
3295failures, but not defers. However, always log it for defer, and log it for fail
3296unless the sender_verify_fail log selector has been turned off. */
059ec3d9 3297
02b41d71 3298if (sender_verified_failed &&
059ec3d9
PH
3299 !testflag(sender_verified_failed, af_sverify_told))
3300 {
88752192
JH
3301 BOOL save_rcpt_in_progress = fl.rcpt_in_progress;
3302 fl.rcpt_in_progress = FALSE; /* So as not to treat these as the error */
2679d413 3303
059ec3d9
PH
3304 setflag(sender_verified_failed, af_sverify_told);
3305
6c6d6e48 3306 if (rc != FAIL || LOGGING(sender_verify_fail))
278c6e6c
PH
3307 log_write(0, LOG_MAIN|LOG_REJECT, "%s sender verify %s for <%s>%s",
3308 host_and_ident(TRUE),
3309 ((sender_verified_failed->special_action & 255) == DEFER)? "defer":"fail",
3310 sender_verified_failed->address,
3311 (sender_verified_failed->message == NULL)? US"" :
3312 string_sprintf(": %s", sender_verified_failed->message));
059ec3d9 3313
02b41d71 3314 if (rc == FAIL && sender_verified_failed->user_message)
a5bd321b 3315 smtp_respond(smtp_code, codelen, FALSE, string_sprintf(
059ec3d9
PH
3316 testflag(sender_verified_failed, af_verify_pmfail)?
3317 "Postmaster verification failed while checking <%s>\n%s\n"
3318 "Several RFCs state that you are required to have a postmaster\n"
3319 "mailbox for each mail domain. This host does not accept mail\n"
3320 "from domains whose servers reject the postmaster address."
3321 :
3322 testflag(sender_verified_failed, af_verify_nsfail)?
3323 "Callback setup failed while verifying <%s>\n%s\n"
3324 "The initial connection, or a HELO or MAIL FROM:<> command was\n"
3325 "rejected. Refusing MAIL FROM:<> does not help fight spam, disregards\n"
3326 "RFC requirements, and stops you from receiving standard bounce\n"
3327 "messages. This host does not accept mail from domains whose servers\n"
3328 "refuse bounces."
3329 :
3330 "Verification failed for <%s>\n%s",
3331 sender_verified_failed->address,
3332 sender_verified_failed->user_message));
2679d413 3333
88752192 3334 fl.rcpt_in_progress = save_rcpt_in_progress;
059ec3d9
PH
3335 }
3336
3337/* Sort out text for logging */
3338
3cc3f762
JH
3339log_msg = log_msg ? string_sprintf(": %s", log_msg) : US"";
3340if ((lognl = Ustrchr(log_msg, '\n'))) *lognl = 0;
059ec3d9
PH
3341
3342/* Send permanent failure response to the command, but the code used isn't
3343always a 5xx one - see comments at the start of this function. If the original
3344rc was FAIL_DROP we drop the connection and yield 2. */
3345
ff5929e3
JH
3346if (rc == FAIL)
3347 smtp_respond(smtp_code, codelen, TRUE,
3348 user_msg ? user_msg : US"Administrative prohibition");
059ec3d9
PH
3349
3350/* Send temporary failure response to the command. Don't give any details,
3351unless acl_temp_details is set. This is TRUE for a callout defer, a "defer"
3352verb, and for a header verify when smtp_return_error_details is set.
3353
3354This conditional logic is all somewhat of a mess because of the odd
3355interactions between temp_details and return_error_details. One day it should
3356be re-implemented in a tidier fashion. */
3357
3358else
8768d548 3359 if (f.acl_temp_details && user_msg)
059ec3d9 3360 {
ff5929e3
JH
3361 if ( smtp_return_error_details
3362 && sender_verified_failed
3363 && sender_verified_failed->message
3364 )
a5bd321b 3365 smtp_respond(smtp_code, codelen, FALSE, sender_verified_failed->message);
ff5929e3 3366
a5bd321b 3367 smtp_respond(smtp_code, codelen, TRUE, user_msg);
059ec3d9
PH
3368 }
3369 else
a5bd321b
PH
3370 smtp_respond(smtp_code, codelen, TRUE,
3371 US"Temporary local problem - please try later");
059ec3d9 3372
6ea85e9a
PH
3373/* Log the incident to the logs that are specified by log_reject_target
3374(default main, reject). This can be empty to suppress logging of rejections. If
3375the connection is not forcibly to be dropped, return 0. Otherwise, log why it
3376is closing if required and return 2. */
059ec3d9 3377
6ea85e9a 3378if (log_reject_target != 0)
887291d2 3379 {
e45a1c37 3380#ifdef SUPPORT_TLS
acec9514
JH
3381 gstring * g = s_tlslog(NULL);
3382 uschar * tls = string_from_gstring(g);
fc16abb4 3383 if (!tls) tls = US"";
e45a1c37 3384#else
fc16abb4 3385 uschar * tls = US"";
e45a1c37 3386#endif
3cc3f762
JH
3387 log_write(where == ACL_WHERE_CONNECT ? L_connection_reject : 0,
3388 log_reject_target, "%s%s%s %s%srejected %s%s",
fc16abb4
JH
3389 LOGGING(dnssec) && sender_host_dnssec ? US" DS" : US"",
3390 host_and_ident(TRUE),
3391 tls,
3392 sender_info,
3393 rc == FAIL ? US"" : US"temporarily ",
3394 what, log_msg);
887291d2 3395 }
059ec3d9
PH
3396
3397if (!drop) return 0;
3398
3399log_write(L_smtp_connection, LOG_MAIN, "%s closed by DROP in ACL",
3400 smtp_get_connection_info());
8f128379
PH
3401
3402/* Run the not-quit ACL, but without any custom messages. This should not be a
3403problem, because we get here only if some other ACL has issued "drop", and
3404in that case, *its* custom messages will have been used above. */
3405
3406smtp_notquit_exit(US"acl-drop", NULL, NULL);
059ec3d9
PH
3407return 2;
3408}
3409
3410
3411
3412
3413/*************************************************
8f128379
PH
3414* Handle SMTP exit when QUIT is not given *
3415*************************************************/
3416
3417/* This function provides a logging/statistics hook for when an SMTP connection
3418is dropped on the floor or the other end goes away. It's a global function
3419because it's called from receive.c as well as this module. As well as running
3420the NOTQUIT ACL, if there is one, this function also outputs a final SMTP
3421response, either with a custom message from the ACL, or using a default. There
3422is one case, however, when no message is output - after "drop". In that case,
3423the ACL that obeyed "drop" has already supplied the custom message, and NULL is
3424passed to this function.
3425
3426In case things go wrong while processing this function, causing an error that
4c04137d 3427may re-enter this function, there is a recursion check.
8f128379
PH
3428
3429Arguments:
3430 reason What $smtp_notquit_reason will be set to in the ACL;
3431 if NULL, the ACL is not run
3432 code The error code to return as part of the response
3433 defaultrespond The default message if there's no user_msg
3434
3435Returns: Nothing
3436*/
3437
3438void
3439smtp_notquit_exit(uschar *reason, uschar *code, uschar *defaultrespond, ...)
3440{
3441int rc;
3442uschar *user_msg = NULL;
3443uschar *log_msg = NULL;
3444
3445/* Check for recursive acll */
3446
88752192 3447if (fl.smtp_exit_function_called)
8f128379
PH
3448 {
3449 log_write(0, LOG_PANIC, "smtp_notquit_exit() called more than once (%s)",
3450 reason);
3451 return;
3452 }
88752192 3453fl.smtp_exit_function_called = TRUE;
8f128379
PH
3454
3455/* Call the not-QUIT ACL, if there is one, unless no reason is given. */
3456
eea0defe 3457if (acl_smtp_notquit && reason)
8f128379
PH
3458 {
3459 smtp_notquit_reason = reason;
eea0defe
JB
3460 if ((rc = acl_check(ACL_WHERE_NOTQUIT, NULL, acl_smtp_notquit, &user_msg,
3461 &log_msg)) == ERROR)
8f128379
PH
3462 log_write(0, LOG_MAIN|LOG_PANIC, "ACL for not-QUIT returned ERROR: %s",
3463 log_msg);
3464 }
3465
3466/* Write an SMTP response if we are expected to give one. As the default
3467responses are all internal, they should always fit in the buffer, but code a
3468warning, just in case. Note that string_vformat() still leaves a complete
3469string, even if it is incomplete. */
3470
eea0defe 3471if (code && defaultrespond)
8f128379 3472 {
eea0defe
JB
3473 if (user_msg)
3474 smtp_respond(code, 3, TRUE, user_msg);
3475 else
8f128379
PH
3476 {
3477 uschar buffer[128];
3478 va_list ap;
3479 va_start(ap, defaultrespond);
3480 if (!string_vformat(buffer, sizeof(buffer), CS defaultrespond, ap))
3481 log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_notquit_exit()");
925ac8e4 3482 smtp_printf("%s %s\r\n", FALSE, code, buffer);
8f128379
PH
3483 va_end(ap);
3484 }
8f128379
PH
3485 mac_smtp_fflush();
3486 }
3487}
3488
3489
3490
3491
3492/*************************************************
d7b47fd0
PH
3493* Verify HELO argument *
3494*************************************************/
3495
3496/* This function is called if helo_verify_hosts or helo_try_verify_hosts is
3497matched. It is also called from ACL processing if verify = helo is used and
3498verification was not previously tried (i.e. helo_try_verify_hosts was not
3499matched). The result of its processing is to set helo_verified and
3500helo_verify_failed. These variables should both be FALSE for this function to
3501be called.
3502
3503Note that EHLO/HELO is legitimately allowed to quote an address literal. Allow
3504for IPv6 ::ffff: literals.
3505
3506Argument: none
3507Returns: TRUE if testing was completed;
3508 FALSE on a temporary failure
3509*/
3510
3511BOOL