Add check on tls_auth pseudo-command. Bug 1659
[exim.git] / src / src / smtp_in.c
CommitLineData
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1/*************************************************
2* Exim - an Internet mail transport agent *
3*************************************************/
4
3386088d 5/* Copyright (c) University of Cambridge 1995 - 2015 */
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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"
12
13
14/* Initialize for TCP wrappers if so configured. It appears that the macro
15HAVE_IPV6 is used in some versions of the tcpd.h header, so we unset it before
16including that header, and restore its value afterwards. */
17
18#ifdef USE_TCP_WRAPPERS
19
20 #if HAVE_IPV6
21 #define EXIM_HAVE_IPV6
22 #endif
23 #undef HAVE_IPV6
24 #include <tcpd.h>
25 #undef HAVE_IPV6
26 #ifdef EXIM_HAVE_IPV6
27 #define HAVE_IPV6 TRUE
28 #endif
29
30int allow_severity = LOG_INFO;
31int deny_severity = LOG_NOTICE;
5dc43717 32uschar *tcp_wrappers_name;
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33#endif
34
35
8d67ada3
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36/* Size of buffer for reading SMTP commands. We used to use 512, as defined
37by RFC 821. However, RFC 1869 specifies that this must be increased for SMTP
38commands that accept arguments, and this in particular applies to AUTH, where
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39the data can be quite long. More recently this value was 2048 in Exim;
40however, RFC 4954 (circa 2007) recommends 12288 bytes to handle AUTH. Clients
41such as Thunderbird will send an AUTH with an initial-response for GSSAPI.
42The maximum size of a Kerberos ticket under Windows 2003 is 12000 bytes, and
43we need room to handle large base64-encoded AUTHs for GSSAPI.
44*/
45
46#define smtp_cmd_buffer_size 16384
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47
48/* Size of buffer for reading SMTP incoming packets */
49
50#define in_buffer_size 8192
51
52/* Structure for SMTP command list */
53
54typedef struct {
1ba28e2b 55 const char *name;
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56 int len;
57 short int cmd;
58 short int has_arg;
59 short int is_mail_cmd;
60} smtp_cmd_list;
61
62/* Codes for identifying commands. We order them so that those that come first
63are those for which synchronization is always required. Checking this can help
64block some spam. */
65
66enum {
67 /* These commands are required to be synchronized, i.e. to be the last in a
68 block of commands when pipelining. */
69
70 HELO_CMD, EHLO_CMD, DATA_CMD, /* These are listed in the pipelining */
71 VRFY_CMD, EXPN_CMD, NOOP_CMD, /* RFC as requiring synchronization */
72 ETRN_CMD, /* This by analogy with TURN from the RFC */
73 STARTTLS_CMD, /* Required by the STARTTLS RFC */
b3ef41c9 74 TLS_AUTH_CMD, /* auto-command at start of SSL */
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75
76 /* This is a dummy to identify the non-sync commands when pipelining */
77
78 NON_SYNC_CMD_PIPELINING,
79
80 /* These commands need not be synchronized when pipelining */
81
82 MAIL_CMD, RCPT_CMD, RSET_CMD,
83
84 /* This is a dummy to identify the non-sync commands when not pipelining */
85
86 NON_SYNC_CMD_NON_PIPELINING,
87
88 /* I have been unable to find a statement about the use of pipelining
89 with AUTH, so to be on the safe side it is here, though I kind of feel
90 it should be up there with the synchronized commands. */
91
92 AUTH_CMD,
93
94 /* I'm not sure about these, but I don't think they matter. */
95
96 QUIT_CMD, HELP_CMD,
97
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98#ifdef EXPERIMENTAL_PROXY
99 PROXY_FAIL_IGNORE_CMD,
100#endif
101
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102 /* These are specials that don't correspond to actual commands */
103
104 EOF_CMD, OTHER_CMD, BADARG_CMD, BADCHAR_CMD, BADSYN_CMD,
105 TOO_MANY_NONMAIL_CMD };
106
107
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108/* This is a convenience macro for adding the identity of an SMTP command
109to the circular buffer that holds a list of the last n received. */
110
111#define HAD(n) \
112 smtp_connection_had[smtp_ch_index++] = n; \
113 if (smtp_ch_index >= SMTP_HBUFF_SIZE) smtp_ch_index = 0
114
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115
116/*************************************************
117* Local static variables *
118*************************************************/
119
120static auth_instance *authenticated_by;
121static BOOL auth_advertised;
122#ifdef SUPPORT_TLS
123static BOOL tls_advertised;
124#endif
6c1c3d1d 125static BOOL dsn_advertised;
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126static BOOL esmtp;
127static BOOL helo_required = FALSE;
128static BOOL helo_verify = FALSE;
129static BOOL helo_seen;
130static BOOL helo_accept_junk;
131static BOOL count_nonmail;
132static BOOL pipelining_advertised;
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133static BOOL rcpt_smtp_response_same;
134static BOOL rcpt_in_progress;
059ec3d9 135static int nonmail_command_count;
8f128379 136static BOOL smtp_exit_function_called = 0;
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137#ifdef EXPERIMENTAL_INTERNATIONAL
138static BOOL smtputf8_advertised;
139#endif
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140static int synprot_error_count;
141static int unknown_command_count;
142static int sync_cmd_limit;
143static int smtp_write_error = 0;
144
2679d413 145static uschar *rcpt_smtp_response;
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146static uschar *smtp_data_buffer;
147static uschar *smtp_cmd_data;
148
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149/* We need to know the position of RSET, HELO, EHLO, AUTH, and STARTTLS. Their
150final fields of all except AUTH are forced TRUE at the start of a new message
151setup, to allow one of each between messages that is not counted as a nonmail
152command. (In fact, only one of HELO/EHLO is not counted.) Also, we have to
153allow a new EHLO after starting up TLS.
154
155AUTH is "falsely" labelled as a mail command initially, so that it doesn't get
156counted. However, the flag is changed when AUTH is received, so that multiple
157failing AUTHs will eventually hit the limit. After a successful AUTH, another
158AUTH is already forbidden. After a TLS session is started, AUTH's flag is again
159forced TRUE, to allow for the re-authentication that can happen at that point.
160
161QUIT is also "falsely" labelled as a mail command so that it doesn't up the
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162count of non-mail commands and possibly provoke an error.
163
164tls_auth is a pseudo-command, never expected in input. It is activated
165on TLS startup and looks for a tls authenticator. */
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166
167static smtp_cmd_list cmd_list[] = {
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168 /* name len cmd has_arg is_mail_cmd */
169
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170 { "rset", sizeof("rset")-1, RSET_CMD, FALSE, FALSE }, /* First */
171 { "helo", sizeof("helo")-1, HELO_CMD, TRUE, FALSE },
172 { "ehlo", sizeof("ehlo")-1, EHLO_CMD, TRUE, FALSE },
173 { "auth", sizeof("auth")-1, AUTH_CMD, TRUE, TRUE },
174 #ifdef SUPPORT_TLS
175 { "starttls", sizeof("starttls")-1, STARTTLS_CMD, FALSE, FALSE },
b3ef41c9 176 { "tls_auth", 0, TLS_AUTH_CMD, FALSE, TRUE },
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177 #endif
178
179/* If you change anything above here, also fix the definitions below. */
180
181 { "mail from:", sizeof("mail from:")-1, MAIL_CMD, TRUE, TRUE },
182 { "rcpt to:", sizeof("rcpt to:")-1, RCPT_CMD, TRUE, TRUE },
183 { "data", sizeof("data")-1, DATA_CMD, FALSE, TRUE },
184 { "quit", sizeof("quit")-1, QUIT_CMD, FALSE, TRUE },
185 { "noop", sizeof("noop")-1, NOOP_CMD, TRUE, FALSE },
186 { "etrn", sizeof("etrn")-1, ETRN_CMD, TRUE, FALSE },
187 { "vrfy", sizeof("vrfy")-1, VRFY_CMD, TRUE, FALSE },
188 { "expn", sizeof("expn")-1, EXPN_CMD, TRUE, FALSE },
189 { "help", sizeof("help")-1, HELP_CMD, TRUE, FALSE }
190};
191
192static smtp_cmd_list *cmd_list_end =
193 cmd_list + sizeof(cmd_list)/sizeof(smtp_cmd_list);
194
195#define CMD_LIST_RSET 0
196#define CMD_LIST_HELO 1
197#define CMD_LIST_EHLO 2
198#define CMD_LIST_AUTH 3
199#define CMD_LIST_STARTTLS 4
b3ef41c9 200#define CMD_LIST_TLS_AUTH 5
059ec3d9 201
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202/* This list of names is used for performing the smtp_no_mail logging action.
203It must be kept in step with the SCH_xxx enumerations. */
204
205static uschar *smtp_names[] =
206 {
207 US"NONE", US"AUTH", US"DATA", US"EHLO", US"ETRN", US"EXPN", US"HELO",
208 US"HELP", US"MAIL", US"NOOP", US"QUIT", US"RCPT", US"RSET", US"STARTTLS",
209 US"VRFY" };
210
e524074d 211static uschar *protocols_local[] = {
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212 US"local-smtp", /* HELO */
213 US"local-smtps", /* The rare case EHLO->STARTTLS->HELO */
214 US"local-esmtp", /* EHLO */
215 US"local-esmtps", /* EHLO->STARTTLS->EHLO */
216 US"local-esmtpa", /* EHLO->AUTH */
217 US"local-esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */
059ec3d9 218 };
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219static uschar *protocols[] = {
220 US"smtp", /* HELO */
221 US"smtps", /* The rare case EHLO->STARTTLS->HELO */
222 US"esmtp", /* EHLO */
223 US"esmtps", /* EHLO->STARTTLS->EHLO */
224 US"esmtpa", /* EHLO->AUTH */
225 US"esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */
226 };
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227
228#define pnormal 0
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229#define pextend 2
230#define pcrpted 1 /* added to pextend or pnormal */
231#define pauthed 2 /* added to pextend */
059ec3d9 232
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233/* Sanity check and validate optional args to MAIL FROM: envelope */
234enum {
235 ENV_MAIL_OPT_SIZE, ENV_MAIL_OPT_BODY, ENV_MAIL_OPT_AUTH,
8ccd00b1 236#ifndef DISABLE_PRDR
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237 ENV_MAIL_OPT_PRDR,
238#endif
6c1c3d1d 239 ENV_MAIL_OPT_RET, ENV_MAIL_OPT_ENVID,
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240#ifdef EXPERIMENTAL_INTERNATIONAL
241 ENV_MAIL_OPT_UTF8,
242#endif
fd98a5c6 243 ENV_MAIL_OPT_NULL
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244 };
245typedef struct {
246 uschar * name; /* option requested during MAIL cmd */
247 int value; /* enum type */
248 BOOL need_value; /* TRUE requires value (name=value pair format)
249 FALSE is a singleton */
250 } env_mail_type_t;
251static env_mail_type_t env_mail_type_list[] = {
252 { US"SIZE", ENV_MAIL_OPT_SIZE, TRUE },
253 { US"BODY", ENV_MAIL_OPT_BODY, TRUE },
254 { US"AUTH", ENV_MAIL_OPT_AUTH, TRUE },
8ccd00b1 255#ifndef DISABLE_PRDR
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256 { US"PRDR", ENV_MAIL_OPT_PRDR, FALSE },
257#endif
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258 { US"RET", ENV_MAIL_OPT_RET, TRUE },
259 { US"ENVID", ENV_MAIL_OPT_ENVID, TRUE },
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260#ifdef EXPERIMENTAL_INTERNATIONAL
261 { US"SMTPUTF8",ENV_MAIL_OPT_UTF8, FALSE }, /* rfc6531 */
262#endif
fd98a5c6 263 { US"NULL", ENV_MAIL_OPT_NULL, FALSE }
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264 };
265
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266/* When reading SMTP from a remote host, we have to use our own versions of the
267C input-reading functions, in order to be able to flush the SMTP output only
268when about to read more data from the socket. This is the only way to get
269optimal performance when the client is using pipelining. Flushing for every
270command causes a separate packet and reply packet each time; saving all the
271responses up (when pipelining) combines them into one packet and one response.
272
273For simplicity, these functions are used for *all* SMTP input, not only when
274receiving over a socket. However, after setting up a secure socket (SSL), input
275is read via the OpenSSL library, and another set of functions is used instead
276(see tls.c).
277
278These functions are set in the receive_getc etc. variables and called with the
279same interface as the C functions. However, since there can only ever be
280one incoming SMTP call, we just use a single buffer and flags. There is no need
281to implement a complicated private FILE-like structure.*/
282
283static uschar *smtp_inbuffer;
284static uschar *smtp_inptr;
285static uschar *smtp_inend;
286static int smtp_had_eof;
287static int smtp_had_error;
288
289
290/*************************************************
291* SMTP version of getc() *
292*************************************************/
293
294/* This gets the next byte from the SMTP input buffer. If the buffer is empty,
295it flushes the output, and refills the buffer, with a timeout. The signal
296handler is set appropriately by the calling function. This function is not used
297after a connection has negotated itself into an TLS/SSL state.
298
299Arguments: none
300Returns: the next character or EOF
301*/
302
303int
304smtp_getc(void)
305{
306if (smtp_inptr >= smtp_inend)
307 {
308 int rc, save_errno;
309 fflush(smtp_out);
310 if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
311 rc = read(fileno(smtp_in), smtp_inbuffer, in_buffer_size);
312 save_errno = errno;
313 alarm(0);
314 if (rc <= 0)
315 {
316 /* Must put the error text in fixed store, because this might be during
317 header reading, where it releases unused store above the header. */
318 if (rc < 0)
319 {
320 smtp_had_error = save_errno;
321 smtp_read_error = string_copy_malloc(
322 string_sprintf(" (error: %s)", strerror(save_errno)));
323 }
324 else smtp_had_eof = 1;
325 return EOF;
326 }
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327#ifndef DISABLE_DKIM
328 dkim_exim_verify_feed(smtp_inbuffer, rc);
329#endif
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330 smtp_inend = smtp_inbuffer + rc;
331 smtp_inptr = smtp_inbuffer;
332 }
333return *smtp_inptr++;
334}
335
336
337
338/*************************************************
339* SMTP version of ungetc() *
340*************************************************/
341
342/* Puts a character back in the input buffer. Only ever
343called once.
344
345Arguments:
346 ch the character
347
348Returns: the character
349*/
350
351int
352smtp_ungetc(int ch)
353{
354*(--smtp_inptr) = ch;
355return ch;
356}
357
358
359
360
361/*************************************************
362* SMTP version of feof() *
363*************************************************/
364
365/* Tests for a previous EOF
366
367Arguments: none
368Returns: non-zero if the eof flag is set
369*/
370
371int
372smtp_feof(void)
373{
374return smtp_had_eof;
375}
376
377
378
379
380/*************************************************
381* SMTP version of ferror() *
382*************************************************/
383
384/* Tests for a previous read error, and returns with errno
385restored to what it was when the error was detected.
386
387Arguments: none
388Returns: non-zero if the error flag is set
389*/
390
391int
392smtp_ferror(void)
393{
394errno = smtp_had_error;
395return smtp_had_error;
396}
397
398
399
58eb016e
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400/*************************************************
401* Test for characters in the SMTP buffer *
402*************************************************/
403
404/* Used at the end of a message
405
406Arguments: none
407Returns: TRUE/FALSE
408*/
409
410BOOL
411smtp_buffered(void)
412{
413return smtp_inptr < smtp_inend;
414}
415
416
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417
418/*************************************************
419* Write formatted string to SMTP channel *
420*************************************************/
421
422/* This is a separate function so that we don't have to repeat everything for
423TLS support or debugging. It is global so that the daemon and the
424authentication functions can use it. It does not return any error indication,
425because major problems such as dropped connections won't show up till an output
426flush for non-TLS connections. The smtp_fflush() function is available for
427checking that: for convenience, TLS output errors are remembered here so that
428they are also picked up later by smtp_fflush().
429
430Arguments:
431 format format string
432 ... optional arguments
433
434Returns: nothing
435*/
436
437void
1ba28e2b 438smtp_printf(const char *format, ...)
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439{
440va_list ap;
441
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442va_start(ap, format);
443smtp_vprintf(format, ap);
444va_end(ap);
445}
446
447/* This is split off so that verify.c:respond_printf() can, in effect, call
448smtp_printf(), bearing in mind that in C a vararg function can't directly
fb08281f 449call another vararg function, only a function which accepts a va_list. */
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450
451void
1ba28e2b 452smtp_vprintf(const char *format, va_list ap)
ce552449 453{
fb08281f
DW
454BOOL yield;
455
456yield = string_vformat(big_buffer, big_buffer_size, format, ap);
ce552449 457
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458DEBUG(D_receive)
459 {
fb08281f
DW
460 void *reset_point = store_get(0);
461 uschar *msg_copy, *cr, *end;
462 msg_copy = string_copy(big_buffer);
463 end = msg_copy + Ustrlen(msg_copy);
464 while ((cr = Ustrchr(msg_copy, '\r')) != NULL) /* lose CRs */
465 memmove(cr, cr + 1, (end--) - cr);
466 debug_printf("SMTP>> %s", msg_copy);
467 store_reset(reset_point);
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468 }
469
fb08281f 470if (!yield)
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471 {
472 log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_printf()");
473 smtp_closedown(US"Unexpected error");
474 exim_exit(EXIT_FAILURE);
475 }
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476
477/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
478have had the same. Note: this code is also present in smtp_respond(). It would
479be tidier to have it only in one place, but when it was added, it was easier to
480do it that way, so as not to have to mess with the code for the RCPT command,
481which sometimes uses smtp_printf() and sometimes smtp_respond(). */
482
483if (rcpt_in_progress)
484 {
485 if (rcpt_smtp_response == NULL)
486 rcpt_smtp_response = string_copy(big_buffer);
487 else if (rcpt_smtp_response_same &&
488 Ustrcmp(rcpt_smtp_response, big_buffer) != 0)
489 rcpt_smtp_response_same = FALSE;
490 rcpt_in_progress = FALSE;
491 }
059ec3d9 492
2679d413 493/* Now write the string */
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494
495#ifdef SUPPORT_TLS
817d9f57 496if (tls_in.active >= 0)
059ec3d9 497 {
817d9f57
JH
498 if (tls_write(TRUE, big_buffer, Ustrlen(big_buffer)) < 0)
499 smtp_write_error = -1;
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500 }
501else
502#endif
503
2679d413 504if (fprintf(smtp_out, "%s", big_buffer) < 0) smtp_write_error = -1;
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505}
506
507
508
509/*************************************************
510* Flush SMTP out and check for error *
511*************************************************/
512
513/* This function isn't currently used within Exim (it detects errors when it
514tries to read the next SMTP input), but is available for use in local_scan().
515For non-TLS connections, it flushes the output and checks for errors. For
516TLS-connections, it checks for a previously-detected TLS write error.
517
518Arguments: none
519Returns: 0 for no error; -1 after an error
520*/
521
522int
523smtp_fflush(void)
524{
817d9f57 525if (tls_in.active < 0 && fflush(smtp_out) != 0) smtp_write_error = -1;
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526return smtp_write_error;
527}
528
529
530
531/*************************************************
532* SMTP command read timeout *
533*************************************************/
534
535/* Signal handler for timing out incoming SMTP commands. This attempts to
536finish off tidily.
537
538Argument: signal number (SIGALRM)
539Returns: nothing
540*/
541
542static void
543command_timeout_handler(int sig)
544{
545sig = sig; /* Keep picky compilers happy */
546log_write(L_lost_incoming_connection,
547 LOG_MAIN, "SMTP command timeout on%s connection from %s",
817d9f57 548 (tls_in.active >= 0)? " TLS" : "",
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549 host_and_ident(FALSE));
550if (smtp_batched_input)
551 moan_smtp_batch(NULL, "421 SMTP command timeout"); /* Does not return */
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552smtp_notquit_exit(US"command-timeout", US"421",
553 US"%s: SMTP command timeout - closing connection", smtp_active_hostname);
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554exim_exit(EXIT_FAILURE);
555}
556
557
558
559/*************************************************
560* SIGTERM received *
561*************************************************/
562
563/* Signal handler for handling SIGTERM. Again, try to finish tidily.
564
565Argument: signal number (SIGTERM)
566Returns: nothing
567*/
568
569static void
570command_sigterm_handler(int sig)
571{
572sig = sig; /* Keep picky compilers happy */
573log_write(0, LOG_MAIN, "%s closed after SIGTERM", smtp_get_connection_info());
574if (smtp_batched_input)
575 moan_smtp_batch(NULL, "421 SIGTERM received"); /* Does not return */
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576smtp_notquit_exit(US"signal-exit", US"421",
577 US"%s: Service not available - closing connection", smtp_active_hostname);
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578exim_exit(EXIT_FAILURE);
579}
580
581
582
a14e5636 583
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584#ifdef EXPERIMENTAL_PROXY
585/*************************************************
a3bddaa8
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586* Restore socket timeout to previous value *
587*************************************************/
588/* If the previous value was successfully retrieved, restore
589it before returning control to the non-proxy routines
590
591Arguments: fd - File descriptor for input
592 get_ok - Successfully retrieved previous values
593 tvtmp - Time struct with previous values
594 vslen - Length of time struct
595Returns: none
596*/
597static void
598restore_socket_timeout(int fd, int get_ok, struct timeval tvtmp, socklen_t vslen)
599{
600if (get_ok == 0)
601 setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, (char *)&tvtmp, vslen);
602}
603
604/*************************************************
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605* Check if host is required proxy host *
606*************************************************/
607/* The function determines if inbound host will be a regular smtp host
608or if it is configured that it must use Proxy Protocol.
609
610Arguments: none
611Returns: bool
612*/
613
614static BOOL
615check_proxy_protocol_host()
616{
617int rc;
618/* Cannot configure local connection as a proxy inbound */
619if (sender_host_address == NULL) return proxy_session;
620
621rc = verify_check_this_host(&proxy_required_hosts, NULL, NULL,
622 sender_host_address, NULL);
623if (rc == OK)
624 {
625 DEBUG(D_receive)
626 debug_printf("Detected proxy protocol configured host\n");
627 proxy_session = TRUE;
628 }
629return proxy_session;
630}
631
632
633/*************************************************
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634* Setup host for proxy protocol *
635*************************************************/
636/* The function configures the connection based on a header from the
637inbound host to use Proxy Protocol. The specification is very exact
638so exit with an error if do not find the exact required pieces. This
639includes an incorrect number of spaces separating args.
640
641Arguments: none
642Returns: int
643*/
644
645static BOOL
646setup_proxy_protocol_host()
647{
648union {
649 struct {
650 uschar line[108];
651 } v1;
652 struct {
653 uschar sig[12];
36719342
TL
654 uint8_t ver_cmd;
655 uint8_t fam;
656 uint16_t len;
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TL
657 union {
658 struct { /* TCP/UDP over IPv4, len = 12 */
659 uint32_t src_addr;
660 uint32_t dst_addr;
661 uint16_t src_port;
662 uint16_t dst_port;
663 } ip4;
664 struct { /* TCP/UDP over IPv6, len = 36 */
665 uint8_t src_addr[16];
666 uint8_t dst_addr[16];
667 uint16_t src_port;
668 uint16_t dst_port;
669 } ip6;
670 struct { /* AF_UNIX sockets, len = 216 */
671 uschar src_addr[108];
672 uschar dst_addr[108];
673 } unx;
674 } addr;
675 } v2;
676} hdr;
677
eb57651e
TL
678/* Temp variables used in PPv2 address:port parsing */
679uint16_t tmpport;
680char tmpip[INET_ADDRSTRLEN];
681struct sockaddr_in tmpaddr;
682char tmpip6[INET6_ADDRSTRLEN];
683struct sockaddr_in6 tmpaddr6;
684
685int get_ok = 0;
a3c86431 686int size, ret, fd;
36719342 687const char v2sig[12] = "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A";
a3c86431
TL
688uschar *iptype; /* To display debug info */
689struct timeval tv;
a3bddaa8
TL
690socklen_t vslen = 0;
691struct timeval tvtmp;
692
693vslen = sizeof(struct timeval);
a3c86431
TL
694
695fd = fileno(smtp_in);
696
a3bddaa8
TL
697/* Save current socket timeout values */
698get_ok = getsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, (char *)&tvtmp,
699 &vslen);
700
a3c86431
TL
701/* Proxy Protocol host must send header within a short time
702(default 3 seconds) or it's considered invalid */
703tv.tv_sec = PROXY_NEGOTIATION_TIMEOUT_SEC;
704tv.tv_usec = PROXY_NEGOTIATION_TIMEOUT_USEC;
705setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, (char *)&tv,
706 sizeof(struct timeval));
a3bddaa8 707
a3c86431
TL
708do
709 {
eb57651e
TL
710 /* The inbound host was declared to be a Proxy Protocol host, so
711 don't do a PEEK into the data, actually slurp it up. */
712 ret = recv(fd, &hdr, sizeof(hdr), 0);
a3c86431
TL
713 }
714 while (ret == -1 && errno == EINTR);
715
716if (ret == -1)
a3bddaa8
TL
717 {
718 restore_socket_timeout(fd, get_ok, tvtmp, vslen);
a3c86431 719 return (errno == EAGAIN) ? 0 : ERRNO_PROXYFAIL;
a3bddaa8 720 }
a3c86431
TL
721
722if (ret >= 16 &&
36719342 723 memcmp(&hdr.v2, v2sig, 12) == 0)
a3c86431 724 {
36719342
TL
725 uint8_t ver, cmd;
726
727 /* May 2014: haproxy combined the version and command into one byte to
728 allow two full bytes for the length field in order to proxy SSL
729 connections. SSL Proxy is not supported in this version of Exim, but
730 must still seperate values here. */
731 ver = (hdr.v2.ver_cmd & 0xf0) >> 4;
732 cmd = (hdr.v2.ver_cmd & 0x0f);
733
734 if (ver != 0x02)
735 {
736 DEBUG(D_receive) debug_printf("Invalid Proxy Protocol version: %d\n", ver);
737 goto proxyfail;
738 }
a3c86431 739 DEBUG(D_receive) debug_printf("Detected PROXYv2 header\n");
36719342 740 /* The v2 header will always be 16 bytes per the spec. */
a3c86431
TL
741 size = 16 + hdr.v2.len;
742 if (ret < size)
743 {
36719342
TL
744 DEBUG(D_receive) debug_printf("Truncated or too large PROXYv2 header (%d/%d)\n",
745 ret, size);
a3c86431
TL
746 goto proxyfail;
747 }
36719342 748 switch (cmd)
a3c86431
TL
749 {
750 case 0x01: /* PROXY command */
751 switch (hdr.v2.fam)
752 {
eb57651e
TL
753 case 0x11: /* TCPv4 address type */
754 iptype = US"IPv4";
755 tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.src_addr;
756 inet_ntop(AF_INET, &(tmpaddr.sin_addr), (char *)&tmpip, sizeof(tmpip));
757 if (!string_is_ip_address(US tmpip,NULL))
758 {
759 DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
a3c86431 760 return ERRNO_PROXYFAIL;
eb57651e
TL
761 }
762 proxy_host_address = sender_host_address;
763 sender_host_address = string_copy(US tmpip);
764 tmpport = ntohs(hdr.v2.addr.ip4.src_port);
765 proxy_host_port = sender_host_port;
766 sender_host_port = tmpport;
767 /* Save dest ip/port */
768 tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.dst_addr;
769 inet_ntop(AF_INET, &(tmpaddr.sin_addr), (char *)&tmpip, sizeof(tmpip));
770 if (!string_is_ip_address(US tmpip,NULL))
771 {
772 DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype);
773 return ERRNO_PROXYFAIL;
774 }
775 proxy_target_address = string_copy(US tmpip);
776 tmpport = ntohs(hdr.v2.addr.ip4.dst_port);
777 proxy_target_port = tmpport;
a3c86431 778 goto done;
eb57651e
TL
779 case 0x21: /* TCPv6 address type */
780 iptype = US"IPv6";
781 memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.src_addr, 16);
782 inet_ntop(AF_INET6, &(tmpaddr6.sin6_addr), (char *)&tmpip6, sizeof(tmpip6));
783 if (!string_is_ip_address(US tmpip6,NULL))
784 {
785 DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
786 return ERRNO_PROXYFAIL;
787 }
788 proxy_host_address = sender_host_address;
789 sender_host_address = string_copy(US tmpip6);
790 tmpport = ntohs(hdr.v2.addr.ip6.src_port);
791 proxy_host_port = sender_host_port;
792 sender_host_port = tmpport;
793 /* Save dest ip/port */
794 memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.dst_addr, 16);
795 inet_ntop(AF_INET6, &(tmpaddr6.sin6_addr), (char *)&tmpip6, sizeof(tmpip6));
796 if (!string_is_ip_address(US tmpip6,NULL))
797 {
798 DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype);
a3c86431 799 return ERRNO_PROXYFAIL;
eb57651e
TL
800 }
801 proxy_target_address = string_copy(US tmpip6);
802 tmpport = ntohs(hdr.v2.addr.ip6.dst_port);
803 proxy_target_port = tmpport;
a3c86431 804 goto done;
eb57651e
TL
805 default:
806 DEBUG(D_receive)
807 debug_printf("Unsupported PROXYv2 connection type: 0x%02x\n",
808 hdr.v2.fam);
809 goto proxyfail;
a3c86431
TL
810 }
811 /* Unsupported protocol, keep local connection address */
812 break;
813 case 0x00: /* LOCAL command */
814 /* Keep local connection address for LOCAL */
815 break;
816 default:
eb57651e 817 DEBUG(D_receive)
36719342 818 debug_printf("Unsupported PROXYv2 command: 0x%x\n", cmd);
a3c86431
TL
819 goto proxyfail;
820 }
821 }
822else if (ret >= 8 &&
823 memcmp(hdr.v1.line, "PROXY", 5) == 0)
824 {
825 uschar *p = string_copy(hdr.v1.line);
826 uschar *end = memchr(p, '\r', ret - 1);
827 uschar *sp; /* Utility variables follow */
828 int tmp_port;
829 char *endc;
830
831 if (!end || end[1] != '\n')
832 {
833 DEBUG(D_receive) debug_printf("Partial or invalid PROXY header\n");
834 goto proxyfail;
835 }
836 *end = '\0'; /* Terminate the string */
837 size = end + 2 - hdr.v1.line; /* Skip header + CRLF */
838 DEBUG(D_receive) debug_printf("Detected PROXYv1 header\n");
839 /* Step through the string looking for the required fields. Ensure
840 strict adherance to required formatting, exit for any error. */
841 p += 5;
842 if (!isspace(*(p++)))
843 {
844 DEBUG(D_receive) debug_printf("Missing space after PROXY command\n");
845 goto proxyfail;
846 }
847 if (!Ustrncmp(p, CCS"TCP4", 4))
848 iptype = US"IPv4";
849 else if (!Ustrncmp(p,CCS"TCP6", 4))
850 iptype = US"IPv6";
851 else if (!Ustrncmp(p,CCS"UNKNOWN", 7))
852 {
853 iptype = US"Unknown";
854 goto done;
855 }
856 else
857 {
858 DEBUG(D_receive) debug_printf("Invalid TCP type\n");
859 goto proxyfail;
860 }
861
862 p += Ustrlen(iptype);
863 if (!isspace(*(p++)))
864 {
865 DEBUG(D_receive) debug_printf("Missing space after TCP4/6 command\n");
866 goto proxyfail;
867 }
868 /* Find the end of the arg */
869 if ((sp = Ustrchr(p, ' ')) == NULL)
870 {
871 DEBUG(D_receive)
872 debug_printf("Did not find proxied src %s\n", iptype);
873 goto proxyfail;
874 }
875 *sp = '\0';
876 if(!string_is_ip_address(p,NULL))
877 {
878 DEBUG(D_receive)
879 debug_printf("Proxied src arg is not an %s address\n", iptype);
880 goto proxyfail;
881 }
a3bddaa8 882 proxy_host_address = sender_host_address;
a3c86431
TL
883 sender_host_address = p;
884 p = sp + 1;
885 if ((sp = Ustrchr(p, ' ')) == NULL)
886 {
887 DEBUG(D_receive)
888 debug_printf("Did not find proxy dest %s\n", iptype);
889 goto proxyfail;
890 }
891 *sp = '\0';
892 if(!string_is_ip_address(p,NULL))
893 {
894 DEBUG(D_receive)
895 debug_printf("Proxy dest arg is not an %s address\n", iptype);
896 goto proxyfail;
897 }
eb57651e 898 proxy_target_address = p;
a3c86431
TL
899 p = sp + 1;
900 if ((sp = Ustrchr(p, ' ')) == NULL)
901 {
902 DEBUG(D_receive) debug_printf("Did not find proxied src port\n");
903 goto proxyfail;
904 }
905 *sp = '\0';
906 tmp_port = strtol(CCS p,&endc,10);
907 if (*endc || tmp_port == 0)
908 {
909 DEBUG(D_receive)
910 debug_printf("Proxied src port '%s' not an integer\n", p);
911 goto proxyfail;
912 }
a3bddaa8 913 proxy_host_port = sender_host_port;
a3c86431
TL
914 sender_host_port = tmp_port;
915 p = sp + 1;
916 if ((sp = Ustrchr(p, '\0')) == NULL)
917 {
918 DEBUG(D_receive) debug_printf("Did not find proxy dest port\n");
919 goto proxyfail;
920 }
921 tmp_port = strtol(CCS p,&endc,10);
922 if (*endc || tmp_port == 0)
923 {
924 DEBUG(D_receive)
925 debug_printf("Proxy dest port '%s' not an integer\n", p);
926 goto proxyfail;
927 }
eb57651e 928 proxy_target_port = tmp_port;
a3c86431
TL
929 /* Already checked for /r /n above. Good V1 header received. */
930 goto done;
931 }
932else
933 {
934 /* Wrong protocol */
eb57651e 935 DEBUG(D_receive) debug_printf("Invalid proxy protocol version negotiation\n");
a3c86431
TL
936 goto proxyfail;
937 }
938
939proxyfail:
a3bddaa8 940restore_socket_timeout(fd, get_ok, tvtmp, vslen);
a3c86431 941/* Don't flush any potential buffer contents. Any input should cause a
eb57651e 942 synchronization failure */
a3c86431
TL
943return FALSE;
944
945done:
a3bddaa8 946restore_socket_timeout(fd, get_ok, tvtmp, vslen);
a3c86431 947DEBUG(D_receive)
eb57651e 948 debug_printf("Valid %s sender from Proxy Protocol header\n", iptype);
a3c86431
TL
949return proxy_session;
950}
951#endif
952
059ec3d9
PH
953/*************************************************
954* Read one command line *
955*************************************************/
956
957/* Strictly, SMTP commands coming over the net are supposed to end with CRLF.
958There are sites that don't do this, and in any case internal SMTP probably
959should check only for LF. Consequently, we check here for LF only. The line
960ends up with [CR]LF removed from its end. If we get an overlong line, treat as
3ee512ff
PH
961an unknown command. The command is read into the global smtp_cmd_buffer so that
962it is available via $smtp_command.
059ec3d9
PH
963
964The character reading routine sets up a timeout for each block actually read
965from the input (which may contain more than one command). We set up a special
966signal handler that closes down the session on a timeout. Control does not
967return when it runs.
968
969Arguments:
970 check_sync if TRUE, check synchronization rules if global option is TRUE
971
972Returns: a code identifying the command (enumerated above)
973*/
974
975static int
976smtp_read_command(BOOL check_sync)
977{
978int c;
979int ptr = 0;
980smtp_cmd_list *p;
981BOOL hadnull = FALSE;
982
983os_non_restarting_signal(SIGALRM, command_timeout_handler);
984
985while ((c = (receive_getc)()) != '\n' && c != EOF)
986 {
3ee512ff 987 if (ptr >= smtp_cmd_buffer_size)
059ec3d9
PH
988 {
989 os_non_restarting_signal(SIGALRM, sigalrm_handler);
990 return OTHER_CMD;
991 }
992 if (c == 0)
993 {
994 hadnull = TRUE;
995 c = '?';
996 }
3ee512ff 997 smtp_cmd_buffer[ptr++] = c;
059ec3d9
PH
998 }
999
1000receive_linecount++; /* For BSMTP errors */
1001os_non_restarting_signal(SIGALRM, sigalrm_handler);
1002
1003/* If hit end of file, return pseudo EOF command. Whether we have a
1004part-line already read doesn't matter, since this is an error state. */
1005
1006if (c == EOF) return EOF_CMD;
1007
1008/* Remove any CR and white space at the end of the line, and terminate the
1009string. */
1010
3ee512ff
PH
1011while (ptr > 0 && isspace(smtp_cmd_buffer[ptr-1])) ptr--;
1012smtp_cmd_buffer[ptr] = 0;
059ec3d9 1013
3ee512ff 1014DEBUG(D_receive) debug_printf("SMTP<< %s\n", smtp_cmd_buffer);
059ec3d9
PH
1015
1016/* NULLs are not allowed in SMTP commands */
1017
1018if (hadnull) return BADCHAR_CMD;
1019
1020/* Scan command list and return identity, having set the data pointer
1021to the start of the actual data characters. Check for SMTP synchronization
1022if required. */
1023
1024for (p = cmd_list; p < cmd_list_end; p++)
1025 {
a3c86431
TL
1026 #ifdef EXPERIMENTAL_PROXY
1027 /* Only allow QUIT command if Proxy Protocol parsing failed */
1028 if (proxy_session && proxy_session_failed)
1029 {
1030 if (p->cmd != QUIT_CMD)
1031 continue;
1032 }
1033 #endif
2f460950
JH
1034 if ( p->len
1035 && strncmpic(smtp_cmd_buffer, US p->name, p->len) == 0
1036 && ( smtp_cmd_buffer[p->len-1] == ':' /* "mail from:" or "rcpt to:" */
1037 || smtp_cmd_buffer[p->len] == 0
1038 || smtp_cmd_buffer[p->len] == ' '
1039 ) )
059ec3d9
PH
1040 {
1041 if (smtp_inptr < smtp_inend && /* Outstanding input */
1042 p->cmd < sync_cmd_limit && /* Command should sync */
1043 check_sync && /* Local flag set */
1044 smtp_enforce_sync && /* Global flag set */
1045 sender_host_address != NULL && /* Not local input */
1046 !sender_host_notsocket) /* Really is a socket */
1047 return BADSYN_CMD;
1048
ca86f471
PH
1049 /* The variables $smtp_command and $smtp_command_argument point into the
1050 unmodified input buffer. A copy of the latter is taken for actual
1051 processing, so that it can be chopped up into separate parts if necessary,
1052 for example, when processing a MAIL command options such as SIZE that can
1053 follow the sender address. */
059ec3d9 1054
3ee512ff 1055 smtp_cmd_argument = smtp_cmd_buffer + p->len;
ca86f471
PH
1056 while (isspace(*smtp_cmd_argument)) smtp_cmd_argument++;
1057 Ustrcpy(smtp_data_buffer, smtp_cmd_argument);
1058 smtp_cmd_data = smtp_data_buffer;
059ec3d9
PH
1059
1060 /* Count non-mail commands from those hosts that are controlled in this
1061 way. The default is all hosts. We don't waste effort checking the list
1062 until we get a non-mail command, but then cache the result to save checking
1063 again. If there's a DEFER while checking the host, assume it's in the list.
1064
1065 Note that one instance of RSET, EHLO/HELO, and STARTTLS is allowed at the
1066 start of each incoming message by fiddling with the value in the table. */
1067
1068 if (!p->is_mail_cmd)
1069 {
1070 if (count_nonmail == TRUE_UNSET) count_nonmail =
1071 verify_check_host(&smtp_accept_max_nonmail_hosts) != FAIL;
1072 if (count_nonmail && ++nonmail_command_count > smtp_accept_max_nonmail)
1073 return TOO_MANY_NONMAIL_CMD;
1074 }
1075
ca86f471
PH
1076 /* If there is data for a command that does not expect it, generate the
1077 error here. */
059ec3d9 1078
ca86f471 1079 return (p->has_arg || *smtp_cmd_data == 0)? p->cmd : BADARG_CMD;
059ec3d9
PH
1080 }
1081 }
1082
a3c86431
TL
1083#ifdef EXPERIMENTAL_PROXY
1084/* Only allow QUIT command if Proxy Protocol parsing failed */
1085if (proxy_session && proxy_session_failed)
1086 return PROXY_FAIL_IGNORE_CMD;
1087#endif
1088
059ec3d9
PH
1089/* Enforce synchronization for unknown commands */
1090
1091if (smtp_inptr < smtp_inend && /* Outstanding input */
1092 check_sync && /* Local flag set */
1093 smtp_enforce_sync && /* Global flag set */
1094 sender_host_address != NULL && /* Not local input */
1095 !sender_host_notsocket) /* Really is a socket */
1096 return BADSYN_CMD;
1097
1098return OTHER_CMD;
1099}
1100
1101
1102
1103/*************************************************
a14e5636
PH
1104* Recheck synchronization *
1105*************************************************/
1106
1107/* Synchronization checks can never be perfect because a packet may be on its
1108way but not arrived when the check is done. Such checks can in any case only be
1109done when TLS is not in use. Normally, the checks happen when commands are
1110read: Exim ensures that there is no more input in the input buffer. In normal
1111cases, the response to the command will be fast, and there is no further check.
1112
1113However, for some commands an ACL is run, and that can include delays. In those
1114cases, it is useful to do another check on the input just before sending the
1115response. This also applies at the start of a connection. This function does
1116that check by means of the select() function, as long as the facility is not
1117disabled or inappropriate. A failure of select() is ignored.
1118
1119When there is unwanted input, we read it so that it appears in the log of the
1120error.
1121
1122Arguments: none
1123Returns: TRUE if all is well; FALSE if there is input pending
1124*/
1125
1126static BOOL
1127check_sync(void)
1128{
1129int fd, rc;
1130fd_set fds;
1131struct timeval tzero;
1132
1133if (!smtp_enforce_sync || sender_host_address == NULL ||
817d9f57 1134 sender_host_notsocket || tls_in.active >= 0)
a14e5636
PH
1135 return TRUE;
1136
1137fd = fileno(smtp_in);
1138FD_ZERO(&fds);
1139FD_SET(fd, &fds);
1140tzero.tv_sec = 0;
1141tzero.tv_usec = 0;
1142rc = select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &tzero);
1143
1144if (rc <= 0) return TRUE; /* Not ready to read */
1145rc = smtp_getc();
1146if (rc < 0) return TRUE; /* End of file or error */
1147
1148smtp_ungetc(rc);
1149rc = smtp_inend - smtp_inptr;
1150if (rc > 150) rc = 150;
1151smtp_inptr[rc] = 0;
1152return FALSE;
1153}
1154
1155
1156
1157/*************************************************
059ec3d9
PH
1158* Forced closedown of call *
1159*************************************************/
1160
1161/* This function is called from log.c when Exim is dying because of a serious
1162disaster, and also from some other places. If an incoming non-batched SMTP
1163channel is open, it swallows the rest of the incoming message if in the DATA
1164phase, sends the reply string, and gives an error to all subsequent commands
1165except QUIT. The existence of an SMTP call is detected by the non-NULLness of
1166smtp_in.
1167
8f128379
PH
1168Arguments:
1169 message SMTP reply string to send, excluding the code
1170
059ec3d9
PH
1171Returns: nothing
1172*/
1173
1174void
1175smtp_closedown(uschar *message)
1176{
1177if (smtp_in == NULL || smtp_batched_input) return;
1178receive_swallow_smtp();
1179smtp_printf("421 %s\r\n", message);
1180
1181for (;;)
1182 {
1183 switch(smtp_read_command(FALSE))
1184 {
1185 case EOF_CMD:
1186 return;
1187
1188 case QUIT_CMD:
1189 smtp_printf("221 %s closing connection\r\n", smtp_active_hostname);
1190 mac_smtp_fflush();
1191 return;
1192
1193 case RSET_CMD:
1194 smtp_printf("250 Reset OK\r\n");
1195 break;
1196
1197 default:
1198 smtp_printf("421 %s\r\n", message);
1199 break;
1200 }
1201 }
1202}
1203
1204
1205
1206
1207/*************************************************
1208* Set up connection info for logging *
1209*************************************************/
1210
1211/* This function is called when logging information about an SMTP connection.
1212It sets up appropriate source information, depending on the type of connection.
dac79d3e
PH
1213If sender_fullhost is NULL, we are at a very early stage of the connection;
1214just use the IP address.
059ec3d9
PH
1215
1216Argument: none
1217Returns: a string describing the connection
1218*/
1219
1220uschar *
1221smtp_get_connection_info(void)
1222{
dac79d3e
PH
1223uschar *hostname = (sender_fullhost == NULL)?
1224 sender_host_address : sender_fullhost;
1225
059ec3d9 1226if (host_checking)
dac79d3e 1227 return string_sprintf("SMTP connection from %s", hostname);
059ec3d9
PH
1228
1229if (sender_host_unknown || sender_host_notsocket)
1230 return string_sprintf("SMTP connection from %s", sender_ident);
1231
1232if (is_inetd)
dac79d3e 1233 return string_sprintf("SMTP connection from %s (via inetd)", hostname);
059ec3d9
PH
1234
1235if ((log_extra_selector & LX_incoming_interface) != 0 &&
1236 interface_address != NULL)
dac79d3e 1237 return string_sprintf("SMTP connection from %s I=[%s]:%d", hostname,
059ec3d9
PH
1238 interface_address, interface_port);
1239
dac79d3e 1240return string_sprintf("SMTP connection from %s", hostname);
059ec3d9
PH
1241}
1242
1243
1244
e45a1c37 1245#ifdef SUPPORT_TLS
887291d2
JH
1246/* Append TLS-related information to a log line
1247
1248Arguments:
1249 s String under construction: allocated string to extend, or NULL
1250 sizep Pointer to current allocation size (update on return), or NULL
1251 ptrp Pointer to index for new entries in string (update on return), or NULL
1252
1253Returns: Allocated string or NULL
1254*/
e45a1c37
JH
1255static uschar *
1256s_tlslog(uschar * s, int * sizep, int * ptrp)
1257{
1258 int size = sizep ? *sizep : 0;
1259 int ptr = ptrp ? *ptrp : 0;
1260
1261 if ((log_extra_selector & LX_tls_cipher) != 0 && tls_in.cipher != NULL)
1262 s = string_append(s, &size, &ptr, 2, US" X=", tls_in.cipher);
1263 if ((log_extra_selector & LX_tls_certificate_verified) != 0 &&
1264 tls_in.cipher != NULL)
1265 s = string_append(s, &size, &ptr, 2, US" CV=",
1266 tls_in.certificate_verified? "yes":"no");
1267 if ((log_extra_selector & LX_tls_peerdn) != 0 && tls_in.peerdn != NULL)
1268 s = string_append(s, &size, &ptr, 3, US" DN=\"",
1269 string_printing(tls_in.peerdn), US"\"");
1270 if ((log_extra_selector & LX_tls_sni) != 0 && tls_in.sni != NULL)
1271 s = string_append(s, &size, &ptr, 3, US" SNI=\"",
1272 string_printing(tls_in.sni), US"\"");
1273
67d81c10
JH
1274 if (s)
1275 {
1276 s[ptr] = '\0';
1277 if (sizep) *sizep = size;
1278 if (ptrp) *ptrp = ptr;
1279 }
e45a1c37
JH
1280 return s;
1281}
1282#endif
1283
059ec3d9 1284/*************************************************
b4ed4da0
PH
1285* Log lack of MAIL if so configured *
1286*************************************************/
1287
1288/* This function is called when an SMTP session ends. If the log selector
1289smtp_no_mail is set, write a log line giving some details of what has happened
1290in the SMTP session.
1291
1292Arguments: none
1293Returns: nothing
1294*/
1295
1296void
1297smtp_log_no_mail(void)
1298{
1299int size, ptr, i;
1300uschar *s, *sep;
1301
1302if (smtp_mailcmd_count > 0 || (log_extra_selector & LX_smtp_no_mail) == 0)
1303 return;
1304
1305s = NULL;
1306size = ptr = 0;
1307
1308if (sender_host_authenticated != NULL)
1309 {
1310 s = string_append(s, &size, &ptr, 2, US" A=", sender_host_authenticated);
1311 if (authenticated_id != NULL)
1312 s = string_append(s, &size, &ptr, 2, US":", authenticated_id);
1313 }
1314
1315#ifdef SUPPORT_TLS
e45a1c37 1316s = s_tlslog(s, &size, &ptr);
3f0945ff 1317#endif
b4ed4da0
PH
1318
1319sep = (smtp_connection_had[SMTP_HBUFF_SIZE-1] != SCH_NONE)?
1320 US" C=..." : US" C=";
1321for (i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++)
1322 {
1323 if (smtp_connection_had[i] != SCH_NONE)
1324 {
1325 s = string_append(s, &size, &ptr, 2, sep,
1326 smtp_names[smtp_connection_had[i]]);
1327 sep = US",";
1328 }
1329 }
1330
1331for (i = 0; i < smtp_ch_index; i++)
1332 {
1333 s = string_append(s, &size, &ptr, 2, sep, smtp_names[smtp_connection_had[i]]);
1334 sep = US",";
1335 }
1336
1337if (s != NULL) s[ptr] = 0; else s = US"";
1338log_write(0, LOG_MAIN, "no MAIL in SMTP connection from %s D=%s%s",
1339 host_and_ident(FALSE),
19050083
JH
1340 readconf_printtime( (int) ((long)time(NULL) - (long)smtp_connection_start)),
1341 s);
b4ed4da0
PH
1342}
1343
1344
1345
1346/*************************************************
059ec3d9
PH
1347* Check HELO line and set sender_helo_name *
1348*************************************************/
1349
1350/* Check the format of a HELO line. The data for HELO/EHLO is supposed to be
1351the domain name of the sending host, or an ip literal in square brackets. The
1352arrgument is placed in sender_helo_name, which is in malloc store, because it
1353must persist over multiple incoming messages. If helo_accept_junk is set, this
1354host is permitted to send any old junk (needed for some broken hosts).
1355Otherwise, helo_allow_chars can be used for rogue characters in general
1356(typically people want to let in underscores).
1357
1358Argument:
1359 s the data portion of the line (already past any white space)
1360
1361Returns: TRUE or FALSE
1362*/
1363
1364static BOOL
1365check_helo(uschar *s)
1366{
1367uschar *start = s;
1368uschar *end = s + Ustrlen(s);
1369BOOL yield = helo_accept_junk;
1370
1371/* Discard any previous helo name */
1372
1373if (sender_helo_name != NULL)
1374 {
1375 store_free(sender_helo_name);
1376 sender_helo_name = NULL;
1377 }
1378
1379/* Skip tests if junk is permitted. */
1380
1381if (!yield)
1382 {
1383 /* Allow the new standard form for IPv6 address literals, namely,
1384 [IPv6:....], and because someone is bound to use it, allow an equivalent
1385 IPv4 form. Allow plain addresses as well. */
1386
1387 if (*s == '[')
1388 {
1389 if (end[-1] == ']')
1390 {
1391 end[-1] = 0;
1392 if (strncmpic(s, US"[IPv6:", 6) == 0)
1393 yield = (string_is_ip_address(s+6, NULL) == 6);
1394 else if (strncmpic(s, US"[IPv4:", 6) == 0)
1395 yield = (string_is_ip_address(s+6, NULL) == 4);
1396 else
1397 yield = (string_is_ip_address(s+1, NULL) != 0);
1398 end[-1] = ']';
1399 }
1400 }
1401
1402 /* Non-literals must be alpha, dot, hyphen, plus any non-valid chars
1403 that have been configured (usually underscore - sigh). */
1404
1405 else if (*s != 0)
1406 {
1407 yield = TRUE;
1408 while (*s != 0)
1409 {
1410 if (!isalnum(*s) && *s != '.' && *s != '-' &&
1411 Ustrchr(helo_allow_chars, *s) == NULL)
1412 {
1413 yield = FALSE;
1414 break;
1415 }
1416 s++;
1417 }
1418 }
1419 }
1420
1421/* Save argument if OK */
1422
1423if (yield) sender_helo_name = string_copy_malloc(start);
1424return yield;
1425}
1426
1427
1428
1429
1430
1431/*************************************************
1432* Extract SMTP command option *
1433*************************************************/
1434
ca86f471 1435/* This function picks the next option setting off the end of smtp_cmd_data. It
059ec3d9
PH
1436is called for MAIL FROM and RCPT TO commands, to pick off the optional ESMTP
1437things that can appear there.
1438
1439Arguments:
1440 name point this at the name
1441 value point this at the data string
1442
1443Returns: TRUE if found an option
1444*/
1445
1446static BOOL
1447extract_option(uschar **name, uschar **value)
1448{
1449uschar *n;
ca86f471 1450uschar *v = smtp_cmd_data + Ustrlen(smtp_cmd_data) - 1;
059ec3d9
PH
1451while (isspace(*v)) v--;
1452v[1] = 0;
ca86f471 1453while (v > smtp_cmd_data && *v != '=' && !isspace(*v)) v--;
059ec3d9
PH
1454
1455n = v;
fd98a5c6
JH
1456if (*v == '=')
1457{
1458 while(isalpha(n[-1])) n--;
1459 /* RFC says SP, but TAB seen in wild and other major MTAs accept it */
1460 if (!isspace(n[-1])) return FALSE;
1461 n[-1] = 0;
1462}
1463else
1464{
1465 n++;
1466 if (v == smtp_cmd_data) return FALSE;
1467}
059ec3d9 1468*v++ = 0;
fd98a5c6 1469*name = n;
059ec3d9
PH
1470*value = v;
1471return TRUE;
1472}
1473
1474
1475
1476
1477
059ec3d9
PH
1478/*************************************************
1479* Reset for new message *
1480*************************************************/
1481
1482/* This function is called whenever the SMTP session is reset from
1483within either of the setup functions.
1484
1485Argument: the stacking pool storage reset point
1486Returns: nothing
1487*/
1488
1489static void
1490smtp_reset(void *reset_point)
1491{
059ec3d9
PH
1492store_reset(reset_point);
1493recipients_list = NULL;
1494rcpt_count = rcpt_defer_count = rcpt_fail_count =
1495 raw_recipients_count = recipients_count = recipients_list_max = 0;
2e5b33cd 1496cancel_cutthrough_connection("smtp reset");
2e0c1448 1497message_linecount = 0;
059ec3d9 1498message_size = -1;
71fafd95 1499acl_added_headers = NULL;
e7568d51 1500acl_removed_headers = NULL;
059ec3d9 1501queue_only_policy = FALSE;
2679d413
PH
1502rcpt_smtp_response = NULL;
1503rcpt_smtp_response_same = TRUE;
1504rcpt_in_progress = FALSE;
69358f02 1505deliver_freeze = FALSE; /* Can be set by ACL */
6a3f1455 1506freeze_tell = freeze_tell_config; /* Can be set by ACL */
29aba418 1507fake_response = OK; /* Can be set by ACL */
6951ac6c 1508#ifdef WITH_CONTENT_SCAN
8523533c
TK
1509no_mbox_unspool = FALSE; /* Can be set by ACL */
1510#endif
69358f02 1511submission_mode = FALSE; /* Can be set by ACL */
f4ee74ac 1512suppress_local_fixups = suppress_local_fixups_default; /* Can be set by ACL */
69358f02
PH
1513active_local_from_check = local_from_check; /* Can be set by ACL */
1514active_local_sender_retain = local_sender_retain; /* Can be set by ACL */
059ec3d9 1515sender_address = NULL;
2fe1a124 1516submission_name = NULL; /* Can be set by ACL */
059ec3d9
PH
1517raw_sender = NULL; /* After SMTP rewrite, before qualifying */
1518sender_address_unrewritten = NULL; /* Set only after verify rewrite */
1519sender_verified_list = NULL; /* No senders verified */
1520memset(sender_address_cache, 0, sizeof(sender_address_cache));
1521memset(sender_domain_cache, 0, sizeof(sender_domain_cache));
6c1c3d1d 1522
a2b89db1 1523#ifndef DISABLE_PRDR
d1a13eea 1524prdr_requested = FALSE;
a2b89db1 1525#endif
d1a13eea 1526
6c1c3d1d
WB
1527/* Reset the DSN flags */
1528dsn_ret = 0;
1529dsn_envid = NULL;
6c1c3d1d 1530
059ec3d9 1531authenticated_sender = NULL;
8523533c
TK
1532#ifdef EXPERIMENTAL_BRIGHTMAIL
1533bmi_run = 0;
1534bmi_verdicts = NULL;
1535#endif
80a47a2c 1536#ifndef DISABLE_DKIM
9e5d6b55 1537dkim_signers = NULL;
80a47a2c
TK
1538dkim_disable_verify = FALSE;
1539dkim_collect_input = FALSE;
f7572e5a 1540#endif
8523533c
TK
1541#ifdef EXPERIMENTAL_SPF
1542spf_header_comment = NULL;
1543spf_received = NULL;
8e669ac1 1544spf_result = NULL;
8523533c
TK
1545spf_smtp_comment = NULL;
1546#endif
d1a13eea
JH
1547#ifdef EXPERIMENTAL_INTERNATIONAL
1548message_smtputf8 = FALSE;
1549#endif
059ec3d9
PH
1550body_linecount = body_zerocount = 0;
1551
870f6ba8
TF
1552sender_rate = sender_rate_limit = sender_rate_period = NULL;
1553ratelimiters_mail = NULL; /* Updated by ratelimit ACL condition */
1554 /* Note that ratelimiters_conn persists across resets. */
1555
38a0a95f 1556/* Reset message ACL variables */
47ca6d6c 1557
38a0a95f 1558acl_var_m = NULL;
059ec3d9
PH
1559
1560/* The message body variables use malloc store. They may be set if this is
1561not the first message in an SMTP session and the previous message caused them
1562to be referenced in an ACL. */
1563
1564if (message_body != NULL)
1565 {
1566 store_free(message_body);
1567 message_body = NULL;
1568 }
1569
1570if (message_body_end != NULL)
1571 {
1572 store_free(message_body_end);
1573 message_body_end = NULL;
1574 }
1575
1576/* Warning log messages are also saved in malloc store. They are saved to avoid
1577repetition in the same message, but it seems right to repeat them for different
4e88a19f 1578messages. */
059ec3d9
PH
1579
1580while (acl_warn_logged != NULL)
1581 {
1582 string_item *this = acl_warn_logged;
1583 acl_warn_logged = acl_warn_logged->next;
1584 store_free(this);
1585 }
1586}
1587
1588
1589
1590
1591
1592/*************************************************
1593* Initialize for incoming batched SMTP message *
1594*************************************************/
1595
1596/* This function is called from smtp_setup_msg() in the case when
1597smtp_batched_input is true. This happens when -bS is used to pass a whole batch
1598of messages in one file with SMTP commands between them. All errors must be
1599reported by sending a message, and only MAIL FROM, RCPT TO, and DATA are
1600relevant. After an error on a sender, or an invalid recipient, the remainder
1601of the message is skipped. The value of received_protocol is already set.
1602
1603Argument: none
1604Returns: > 0 message successfully started (reached DATA)
1605 = 0 QUIT read or end of file reached
1606 < 0 should not occur
1607*/
1608
1609static int
1610smtp_setup_batch_msg(void)
1611{
1612int done = 0;
1613void *reset_point = store_get(0);
1614
1615/* Save the line count at the start of each transaction - single commands
1616like HELO and RSET count as whole transactions. */
1617
1618bsmtp_transaction_linecount = receive_linecount;
1619
1620if ((receive_feof)()) return 0; /* Treat EOF as QUIT */
1621
1622smtp_reset(reset_point); /* Reset for start of message */
1623
1624/* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
1625value. The values are 2 larger than the required yield of the function. */
1626
1627while (done <= 0)
1628 {
1629 uschar *errmess;
1630 uschar *recipient = NULL;
1631 int start, end, sender_domain, recipient_domain;
1632
1633 switch(smtp_read_command(FALSE))
1634 {
1635 /* The HELO/EHLO commands set sender_address_helo if they have
1636 valid data; otherwise they are ignored, except that they do
1637 a reset of the state. */
1638
1639 case HELO_CMD:
1640 case EHLO_CMD:
1641
ca86f471 1642 check_helo(smtp_cmd_data);
059ec3d9
PH
1643 /* Fall through */
1644
1645 case RSET_CMD:
1646 smtp_reset(reset_point);
1647 bsmtp_transaction_linecount = receive_linecount;
1648 break;
1649
1650
1651 /* The MAIL FROM command requires an address as an operand. All we
1652 do here is to parse it for syntactic correctness. The form "<>" is
1653 a special case which converts into an empty string. The start/end
1654 pointers in the original are not used further for this address, as
1655 it is the canonical extracted address which is all that is kept. */
1656
1657 case MAIL_CMD:
474f71bf 1658 smtp_mailcmd_count++; /* Count for no-mail log */
059ec3d9
PH
1659 if (sender_address != NULL)
1660 /* The function moan_smtp_batch() does not return. */
3ee512ff 1661 moan_smtp_batch(smtp_cmd_buffer, "503 Sender already given");
059ec3d9 1662
ca86f471 1663 if (smtp_cmd_data[0] == 0)
059ec3d9 1664 /* The function moan_smtp_batch() does not return. */
3ee512ff 1665 moan_smtp_batch(smtp_cmd_buffer, "501 MAIL FROM must have an address operand");
059ec3d9
PH
1666
1667 /* Reset to start of message */
1668
1669 smtp_reset(reset_point);
1670
1671 /* Apply SMTP rewrite */
1672
1673 raw_sender = ((rewrite_existflags & rewrite_smtp) != 0)?
ca86f471
PH
1674 rewrite_one(smtp_cmd_data, rewrite_smtp|rewrite_smtp_sender, NULL, FALSE,
1675 US"", global_rewrite_rules) : smtp_cmd_data;
059ec3d9
PH
1676
1677 /* Extract the address; the TRUE flag allows <> as valid */
1678
1679 raw_sender =
1680 parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain,
1681 TRUE);
1682
1683 if (raw_sender == NULL)
1684 /* The function moan_smtp_batch() does not return. */
3ee512ff 1685 moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
059ec3d9
PH
1686
1687 sender_address = string_copy(raw_sender);
1688
1689 /* Qualify unqualified sender addresses if permitted to do so. */
1690
1691 if (sender_domain == 0 && sender_address[0] != 0 && sender_address[0] != '@')
1692 {
1693 if (allow_unqualified_sender)
1694 {
1695 sender_address = rewrite_address_qualify(sender_address, FALSE);
1696 DEBUG(D_receive) debug_printf("unqualified address %s accepted "
1697 "and rewritten\n", raw_sender);
1698 }
1699 /* The function moan_smtp_batch() does not return. */
3ee512ff 1700 else moan_smtp_batch(smtp_cmd_buffer, "501 sender address must contain "
059ec3d9
PH
1701 "a domain");
1702 }
1703 break;
1704
1705
1706 /* The RCPT TO command requires an address as an operand. All we do
1707 here is to parse it for syntactic correctness. There may be any number
1708 of RCPT TO commands, specifying multiple senders. We build them all into
1709 a data structure that is in argc/argv format. The start/end values
1710 given by parse_extract_address are not used, as we keep only the
1711 extracted address. */
1712
1713 case RCPT_CMD:
1714 if (sender_address == NULL)
1715 /* The function moan_smtp_batch() does not return. */
3ee512ff 1716 moan_smtp_batch(smtp_cmd_buffer, "503 No sender yet given");
059ec3d9 1717
ca86f471 1718 if (smtp_cmd_data[0] == 0)
059ec3d9 1719 /* The function moan_smtp_batch() does not return. */
3ee512ff 1720 moan_smtp_batch(smtp_cmd_buffer, "501 RCPT TO must have an address operand");
059ec3d9
PH
1721
1722 /* Check maximum number allowed */
1723
1724 if (recipients_max > 0 && recipients_count + 1 > recipients_max)
1725 /* The function moan_smtp_batch() does not return. */
3ee512ff 1726 moan_smtp_batch(smtp_cmd_buffer, "%s too many recipients",
059ec3d9
PH
1727 recipients_max_reject? "552": "452");
1728
1729 /* Apply SMTP rewrite, then extract address. Don't allow "<>" as a
1730 recipient address */
1731
1732 recipient = ((rewrite_existflags & rewrite_smtp) != 0)?
ca86f471
PH
1733 rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
1734 global_rewrite_rules) : smtp_cmd_data;
059ec3d9
PH
1735
1736 /* rfc821_domains = TRUE; << no longer needed */
1737 recipient = parse_extract_address(recipient, &errmess, &start, &end,
1738 &recipient_domain, FALSE);
1739 /* rfc821_domains = FALSE; << no longer needed */
1740
1741 if (recipient == NULL)
1742 /* The function moan_smtp_batch() does not return. */
3ee512ff 1743 moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
059ec3d9
PH
1744
1745 /* If the recipient address is unqualified, qualify it if permitted. Then
1746 add it to the list of recipients. */
1747
1748 if (recipient_domain == 0)
1749 {
1750 if (allow_unqualified_recipient)
1751 {
1752 DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
1753 recipient);
1754 recipient = rewrite_address_qualify(recipient, TRUE);
1755 }
1756 /* The function moan_smtp_batch() does not return. */
3ee512ff 1757 else moan_smtp_batch(smtp_cmd_buffer, "501 recipient address must contain "
059ec3d9
PH
1758 "a domain");
1759 }
1760 receive_add_recipient(recipient, -1);
1761 break;
1762
1763
1764 /* The DATA command is legal only if it follows successful MAIL FROM
1765 and RCPT TO commands. This function is complete when a valid DATA
1766 command is encountered. */
1767
1768 case DATA_CMD:
1769 if (sender_address == NULL || recipients_count <= 0)
1770 {
1771 /* The function moan_smtp_batch() does not return. */
1772 if (sender_address == NULL)
3ee512ff 1773 moan_smtp_batch(smtp_cmd_buffer,
059ec3d9
PH
1774 "503 MAIL FROM:<sender> command must precede DATA");
1775 else
3ee512ff 1776 moan_smtp_batch(smtp_cmd_buffer,
059ec3d9
PH
1777 "503 RCPT TO:<recipient> must precede DATA");
1778 }
1779 else
1780 {
1781 done = 3; /* DATA successfully achieved */
1782 message_ended = END_NOTENDED; /* Indicate in middle of message */
1783 }
1784 break;
1785
1786
1787 /* The VRFY, EXPN, HELP, ETRN, and NOOP commands are ignored. */
1788
1789 case VRFY_CMD:
1790 case EXPN_CMD:
1791 case HELP_CMD:
1792 case NOOP_CMD:
1793 case ETRN_CMD:
1794 bsmtp_transaction_linecount = receive_linecount;
1795 break;
1796
1797
1798 case EOF_CMD:
1799 case QUIT_CMD:
1800 done = 2;
1801 break;
1802
1803
1804 case BADARG_CMD:
1805 /* The function moan_smtp_batch() does not return. */
3ee512ff 1806 moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected argument data");
059ec3d9
PH
1807 break;
1808
1809
1810 case BADCHAR_CMD:
1811 /* The function moan_smtp_batch() does not return. */
3ee512ff 1812 moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected NULL in SMTP command");
059ec3d9
PH
1813 break;
1814
1815
1816 default:
1817 /* The function moan_smtp_batch() does not return. */
3ee512ff 1818 moan_smtp_batch(smtp_cmd_buffer, "500 Command unrecognized");
059ec3d9
PH
1819 break;
1820 }
1821 }
1822
1823return done - 2; /* Convert yield values */
1824}
1825
1826
1827
1828
1829/*************************************************
1830* Start an SMTP session *
1831*************************************************/
1832
1833/* This function is called at the start of an SMTP session. Thereafter,
1834smtp_setup_msg() is called to initiate each separate message. This
1835function does host-specific testing, and outputs the banner line.
1836
1837Arguments: none
1838Returns: FALSE if the session can not continue; something has
1839 gone wrong, or the connection to the host is blocked
1840*/
1841
1842BOOL
1843smtp_start_session(void)
1844{
1845int size = 256;
4e88a19f
PH
1846int ptr, esclen;
1847uschar *user_msg, *log_msg;
1848uschar *code, *esc;
059ec3d9
PH
1849uschar *p, *s, *ss;
1850
b4ed4da0
PH
1851smtp_connection_start = time(NULL);
1852for (smtp_ch_index = 0; smtp_ch_index < SMTP_HBUFF_SIZE; smtp_ch_index++)
1853 smtp_connection_had[smtp_ch_index] = SCH_NONE;
1854smtp_ch_index = 0;
1855
00f00ca5
PH
1856/* Default values for certain variables */
1857
059ec3d9 1858helo_seen = esmtp = helo_accept_junk = FALSE;
b4ed4da0 1859smtp_mailcmd_count = 0;
059ec3d9
PH
1860count_nonmail = TRUE_UNSET;
1861synprot_error_count = unknown_command_count = nonmail_command_count = 0;
1862smtp_delay_mail = smtp_rlm_base;
1863auth_advertised = FALSE;
1864pipelining_advertised = FALSE;
cf8b11a5 1865pipelining_enable = TRUE;
059ec3d9 1866sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING;
8f128379 1867smtp_exit_function_called = FALSE; /* For avoiding loop in not-quit exit */
059ec3d9
PH
1868
1869memset(sender_host_cache, 0, sizeof(sender_host_cache));
1870
33d73e3b
PH
1871/* If receiving by -bs from a trusted user, or testing with -bh, we allow
1872authentication settings from -oMaa to remain in force. */
1873
1874if (!host_checking && !sender_host_notsocket) sender_host_authenticated = NULL;
059ec3d9
PH
1875authenticated_by = NULL;
1876
1877#ifdef SUPPORT_TLS
817d9f57 1878tls_in.cipher = tls_in.peerdn = NULL;
9d1c15ef
JH
1879tls_in.ourcert = tls_in.peercert = NULL;
1880tls_in.sni = NULL;
44662487 1881tls_in.ocsp = OCSP_NOT_REQ;
059ec3d9
PH
1882tls_advertised = FALSE;
1883#endif
6c1c3d1d 1884dsn_advertised = FALSE;
d1a13eea
JH
1885#ifdef EXPERIMENTAL_INTERNATIONAL
1886smtputf8_advertised = FALSE;
1887#endif
059ec3d9
PH
1888
1889/* Reset ACL connection variables */
1890
38a0a95f 1891acl_var_c = NULL;
059ec3d9 1892
ca86f471 1893/* Allow for trailing 0 in the command and data buffers. */
3ee512ff 1894
ca86f471 1895smtp_cmd_buffer = (uschar *)malloc(2*smtp_cmd_buffer_size + 2);
3ee512ff 1896if (smtp_cmd_buffer == NULL)
059ec3d9
PH
1897 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
1898 "malloc() failed for SMTP command buffer");
2416c261 1899smtp_cmd_buffer[0] = 0;
ca86f471 1900smtp_data_buffer = smtp_cmd_buffer + smtp_cmd_buffer_size + 1;
059ec3d9
PH
1901
1902/* For batched input, the protocol setting can be overridden from the
1903command line by a trusted caller. */
1904
1905if (smtp_batched_input)
1906 {
1907 if (received_protocol == NULL) received_protocol = US"local-bsmtp";
1908 }
1909
1910/* For non-batched SMTP input, the protocol setting is forced here. It will be
1911reset later if any of EHLO/AUTH/STARTTLS are received. */
1912
1913else
1914 received_protocol =
e524074d 1915 (sender_host_address ? protocols : protocols_local) [pnormal];
059ec3d9
PH
1916
1917/* Set up the buffer for inputting using direct read() calls, and arrange to
1918call the local functions instead of the standard C ones. */
1919
1920smtp_inbuffer = (uschar *)malloc(in_buffer_size);
1921if (smtp_inbuffer == NULL)
1922 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "malloc() failed for SMTP input buffer");
1923receive_getc = smtp_getc;
1924receive_ungetc = smtp_ungetc;
1925receive_feof = smtp_feof;
1926receive_ferror = smtp_ferror;
58eb016e 1927receive_smtp_buffered = smtp_buffered;
059ec3d9
PH
1928smtp_inptr = smtp_inend = smtp_inbuffer;
1929smtp_had_eof = smtp_had_error = 0;
1930
1931/* Set up the message size limit; this may be host-specific */
1932
d45b1de8
PH
1933thismessage_size_limit = expand_string_integer(message_size_limit, TRUE);
1934if (expand_string_message != NULL)
059ec3d9
PH
1935 {
1936 if (thismessage_size_limit == -1)
1937 log_write(0, LOG_MAIN|LOG_PANIC, "unable to expand message_size_limit: "
1938 "%s", expand_string_message);
1939 else
1940 log_write(0, LOG_MAIN|LOG_PANIC, "invalid message_size_limit: "
1941 "%s", expand_string_message);
1942 smtp_closedown(US"Temporary local problem - please try later");
1943 return FALSE;
1944 }
1945
1946/* When a message is input locally via the -bs or -bS options, sender_host_
1947unknown is set unless -oMa was used to force an IP address, in which case it
1948is checked like a real remote connection. When -bs is used from inetd, this
1949flag is not set, causing the sending host to be checked. The code that deals
1950with IP source routing (if configured) is never required for -bs or -bS and
1951the flag sender_host_notsocket is used to suppress it.
1952
1953If smtp_accept_max and smtp_accept_reserve are set, keep some connections in
1954reserve for certain hosts and/or networks. */
1955
1956if (!sender_host_unknown)
1957 {
1958 int rc;
1959 BOOL reserved_host = FALSE;
1960
1961 /* Look up IP options (source routing info) on the socket if this is not an
1962 -oMa "host", and if any are found, log them and drop the connection.
1963
1964 Linux (and others now, see below) is different to everyone else, so there
1965 has to be some conditional compilation here. Versions of Linux before 2.1.15
1966 used a structure whose name was "options". Somebody finally realized that
1967 this name was silly, and it got changed to "ip_options". I use the
1968 newer name here, but there is a fudge in the script that sets up os.h
1969 to define a macro in older Linux systems.
1970
1971 Sigh. Linux is a fast-moving target. Another generation of Linux uses
1972 glibc 2, which has chosen ip_opts for the structure name. This is now
1973 really a glibc thing rather than a Linux thing, so the condition name
1974 has been changed to reflect this. It is relevant also to GNU/Hurd.
1975
1976 Mac OS 10.x (Darwin) is like the later glibc versions, but without the
1977 setting of the __GLIBC__ macro, so we can't detect it automatically. There's
1978 a special macro defined in the os.h file.
1979
1980 Some DGUX versions on older hardware appear not to support IP options at
1981 all, so there is now a general macro which can be set to cut out this
1982 support altogether.
1983
1984 How to do this properly in IPv6 is not yet known. */
1985
1986 #if !HAVE_IPV6 && !defined(NO_IP_OPTIONS)
1987
1988 #ifdef GLIBC_IP_OPTIONS
1989 #if (!defined __GLIBC__) || (__GLIBC__ < 2)
1990 #define OPTSTYLE 1
1991 #else
1992 #define OPTSTYLE 2
1993 #endif
1994 #elif defined DARWIN_IP_OPTIONS
1995 #define OPTSTYLE 2
1996 #else
1997 #define OPTSTYLE 3
1998 #endif
1999
2000 if (!host_checking && !sender_host_notsocket)
2001 {
2002 #if OPTSTYLE == 1
36a3b041 2003 EXIM_SOCKLEN_T optlen = sizeof(struct ip_options) + MAX_IPOPTLEN;
059ec3d9
PH
2004 struct ip_options *ipopt = store_get(optlen);
2005 #elif OPTSTYLE == 2
2006 struct ip_opts ipoptblock;
2007 struct ip_opts *ipopt = &ipoptblock;
36a3b041 2008 EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
059ec3d9
PH
2009 #else
2010 struct ipoption ipoptblock;
2011 struct ipoption *ipopt = &ipoptblock;
36a3b041 2012 EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
059ec3d9
PH
2013 #endif
2014
2015 /* Occasional genuine failures of getsockopt() have been seen - for
2016 example, "reset by peer". Therefore, just log and give up on this
2017 call, unless the error is ENOPROTOOPT. This error is given by systems
2018 that have the interfaces but not the mechanism - e.g. GNU/Hurd at the time
2019 of writing. So for that error, carry on - we just can't do an IP options
2020 check. */
2021
2022 DEBUG(D_receive) debug_printf("checking for IP options\n");
2023
2024 if (getsockopt(fileno(smtp_out), IPPROTO_IP, IP_OPTIONS, (uschar *)(ipopt),
2025 &optlen) < 0)
2026 {
2027 if (errno != ENOPROTOOPT)
2028 {
2029 log_write(0, LOG_MAIN, "getsockopt() failed from %s: %s",
2030 host_and_ident(FALSE), strerror(errno));
2031 smtp_printf("451 SMTP service not available\r\n");
2032 return FALSE;
2033 }
2034 }
2035
2036 /* Deal with any IP options that are set. On the systems I have looked at,
2037 the value of MAX_IPOPTLEN has been 40, meaning that there should never be
2038 more logging data than will fit in big_buffer. Nevertheless, after somebody
2039 questioned this code, I've added in some paranoid checking. */
2040
2041 else if (optlen > 0)
2042 {
2043 uschar *p = big_buffer;
2044 uschar *pend = big_buffer + big_buffer_size;
2045 uschar *opt, *adptr;
2046 int optcount;
2047 struct in_addr addr;
2048
2049 #if OPTSTYLE == 1
2050 uschar *optstart = (uschar *)(ipopt->__data);
2051 #elif OPTSTYLE == 2
2052 uschar *optstart = (uschar *)(ipopt->ip_opts);
2053 #else
2054 uschar *optstart = (uschar *)(ipopt->ipopt_list);
2055 #endif
2056
2057 DEBUG(D_receive) debug_printf("IP options exist\n");
2058
2059 Ustrcpy(p, "IP options on incoming call:");
2060 p += Ustrlen(p);
2061
2062 for (opt = optstart; opt != NULL &&
2063 opt < (uschar *)(ipopt) + optlen;)
2064 {
2065 switch (*opt)
2066 {
2067 case IPOPT_EOL:
2068 opt = NULL;
2069 break;
2070
2071 case IPOPT_NOP:
2072 opt++;
2073 break;
2074
2075 case IPOPT_SSRR:
2076 case IPOPT_LSRR:
2077 if (!string_format(p, pend-p, " %s [@%s",
2078 (*opt == IPOPT_SSRR)? "SSRR" : "LSRR",
2079 #if OPTSTYLE == 1
2080 inet_ntoa(*((struct in_addr *)(&(ipopt->faddr))))))
2081 #elif OPTSTYLE == 2
2082 inet_ntoa(ipopt->ip_dst)))
2083 #else
2084 inet_ntoa(ipopt->ipopt_dst)))
2085 #endif
2086 {
2087 opt = NULL;
2088 break;
2089 }
2090
2091 p += Ustrlen(p);
2092 optcount = (opt[1] - 3) / sizeof(struct in_addr);
2093 adptr = opt + 3;
2094 while (optcount-- > 0)
2095 {
2096 memcpy(&addr, adptr, sizeof(addr));
2097 if (!string_format(p, pend - p - 1, "%s%s",
2098 (optcount == 0)? ":" : "@", inet_ntoa(addr)))
2099 {
2100 opt = NULL;
2101 break;
2102 }
2103 p += Ustrlen(p);
2104 adptr += sizeof(struct in_addr);
2105 }
2106 *p++ = ']';
2107 opt += opt[1];
2108 break;
2109
2110 default:
2111 {
2112 int i;
2113 if (pend - p < 4 + 3*opt[1]) { opt = NULL; break; }
2114 Ustrcat(p, "[ ");
2115 p += 2;
2116 for (i = 0; i < opt[1]; i++)
2117 {
2118 sprintf(CS p, "%2.2x ", opt[i]);
2119 p += 3;
2120 }
2121 *p++ = ']';
2122 }
2123 opt += opt[1];
2124 break;
2125 }
2126 }
2127
2128 *p = 0;
2129 log_write(0, LOG_MAIN, "%s", big_buffer);
2130
2131 /* Refuse any call with IP options. This is what tcpwrappers 7.5 does. */
2132
2133 log_write(0, LOG_MAIN|LOG_REJECT,
2134 "connection from %s refused (IP options)", host_and_ident(FALSE));
2135
2136 smtp_printf("554 SMTP service not available\r\n");
2137 return FALSE;
2138 }
2139
2140 /* Length of options = 0 => there are no options */
2141
2142 else DEBUG(D_receive) debug_printf("no IP options found\n");
2143 }
2144 #endif /* HAVE_IPV6 && !defined(NO_IP_OPTIONS) */
2145
2146 /* Set keep-alive in socket options. The option is on by default. This
2147 setting is an attempt to get rid of some hanging connections that stick in
2148 read() when the remote end (usually a dialup) goes away. */
2149
2150 if (smtp_accept_keepalive && !sender_host_notsocket)
2151 ip_keepalive(fileno(smtp_out), sender_host_address, FALSE);
2152
2153 /* If the current host matches host_lookup, set the name by doing a
2154 reverse lookup. On failure, sender_host_name will be NULL and
2155 host_lookup_failed will be TRUE. This may or may not be serious - optional
2156 checks later. */
2157
2158 if (verify_check_host(&host_lookup) == OK)
2159 {
2160 (void)host_name_lookup();
2161 host_build_sender_fullhost();
2162 }
2163
2164 /* Delay this until we have the full name, if it is looked up. */
2165
2166 set_process_info("handling incoming connection from %s",
2167 host_and_ident(FALSE));
2168
1ad6489e
JH
2169 /* Expand smtp_receive_timeout, if needed */
2170
2171 if (smtp_receive_timeout_s)
2172 {
2173 uschar * exp;
2174 if ( !(exp = expand_string(smtp_receive_timeout_s))
2175 || !(*exp)
2176 || (smtp_receive_timeout = readconf_readtime(exp, 0, FALSE)) < 0
2177 )
2178 log_write(0, LOG_MAIN|LOG_PANIC,
2179 "bad value for smtp_receive_timeout: '%s'", exp ? exp : US"");
2180 }
2181
059ec3d9
PH
2182 /* Start up TLS if tls_on_connect is set. This is for supporting the legacy
2183 smtps port for use with older style SSL MTAs. */
2184
2185 #ifdef SUPPORT_TLS
817d9f57 2186 if (tls_in.on_connect && tls_server_start(tls_require_ciphers) != OK)
059ec3d9
PH
2187 return FALSE;
2188 #endif
2189
2190 /* Test for explicit connection rejection */
2191
2192 if (verify_check_host(&host_reject_connection) == OK)
2193 {
2194 log_write(L_connection_reject, LOG_MAIN|LOG_REJECT, "refused connection "
2195 "from %s (host_reject_connection)", host_and_ident(FALSE));
2196 smtp_printf("554 SMTP service not available\r\n");
2197 return FALSE;
2198 }
2199
afb3eaaf
PH
2200 /* Test with TCP Wrappers if so configured. There is a problem in that
2201 hosts_ctl() returns 0 (deny) under a number of system failure circumstances,
2202 such as disks dying. In these cases, it is desirable to reject with a 4xx
2203 error instead of a 5xx error. There isn't a "right" way to detect such
2204 problems. The following kludge is used: errno is zeroed before calling
2205 hosts_ctl(). If the result is "reject", a 5xx error is given only if the
2206 value of errno is 0 or ENOENT (which happens if /etc/hosts.{allow,deny} does
2207 not exist). */
059ec3d9
PH
2208
2209 #ifdef USE_TCP_WRAPPERS
afb3eaaf 2210 errno = 0;
5dc43717
JJ
2211 tcp_wrappers_name = expand_string(tcp_wrappers_daemon_name);
2212 if (tcp_wrappers_name == NULL)
2213 {
2214 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" "
2215 "(tcp_wrappers_name) failed: %s", string_printing(tcp_wrappers_name),
2216 expand_string_message);
2217 }
2218 if (!hosts_ctl(tcp_wrappers_name,
059ec3d9
PH
2219 (sender_host_name == NULL)? STRING_UNKNOWN : CS sender_host_name,
2220 (sender_host_address == NULL)? STRING_UNKNOWN : CS sender_host_address,
2221 (sender_ident == NULL)? STRING_UNKNOWN : CS sender_ident))
2222 {
afb3eaaf
PH
2223 if (errno == 0 || errno == ENOENT)
2224 {
2225 HDEBUG(D_receive) debug_printf("tcp wrappers rejection\n");
2226 log_write(L_connection_reject,
2227 LOG_MAIN|LOG_REJECT, "refused connection from %s "
2228 "(tcp wrappers)", host_and_ident(FALSE));
2229 smtp_printf("554 SMTP service not available\r\n");
2230 }
2231 else
2232 {
2233 int save_errno = errno;
2234 HDEBUG(D_receive) debug_printf("tcp wrappers rejected with unexpected "
2235 "errno value %d\n", save_errno);
2236 log_write(L_connection_reject,
2237 LOG_MAIN|LOG_REJECT, "temporarily refused connection from %s "
2238 "(tcp wrappers errno=%d)", host_and_ident(FALSE), save_errno);
2239 smtp_printf("451 Temporary local problem - please try later\r\n");
2240 }
059ec3d9
PH
2241 return FALSE;
2242 }
2243 #endif
2244
b01dd148
PH
2245 /* Check for reserved slots. The value of smtp_accept_count has already been
2246 incremented to include this process. */
059ec3d9
PH
2247
2248 if (smtp_accept_max > 0 &&
b01dd148 2249 smtp_accept_count > smtp_accept_max - smtp_accept_reserve)
059ec3d9
PH
2250 {
2251 if ((rc = verify_check_host(&smtp_reserve_hosts)) != OK)
2252 {
2253 log_write(L_connection_reject,
2254 LOG_MAIN, "temporarily refused connection from %s: not in "
2255 "reserve list: connected=%d max=%d reserve=%d%s",
b01dd148 2256 host_and_ident(FALSE), smtp_accept_count - 1, smtp_accept_max,
059ec3d9
PH
2257 smtp_accept_reserve, (rc == DEFER)? " (lookup deferred)" : "");
2258 smtp_printf("421 %s: Too many concurrent SMTP connections; "
2259 "please try again later\r\n", smtp_active_hostname);
2260 return FALSE;
2261 }
2262 reserved_host = TRUE;
2263 }
2264
2265 /* If a load level above which only messages from reserved hosts are
2266 accepted is set, check the load. For incoming calls via the daemon, the
2267 check is done in the superior process if there are no reserved hosts, to
2268 save a fork. In all cases, the load average will already be available
2269 in a global variable at this point. */
2270
2271 if (smtp_load_reserve >= 0 &&
2272 load_average > smtp_load_reserve &&
2273 !reserved_host &&
2274 verify_check_host(&smtp_reserve_hosts) != OK)
2275 {
2276 log_write(L_connection_reject,
2277 LOG_MAIN, "temporarily refused connection from %s: not in "
2278 "reserve list and load average = %.2f", host_and_ident(FALSE),
2279 (double)load_average/1000.0);
2280 smtp_printf("421 %s: Too much load; please try again later\r\n",
2281 smtp_active_hostname);
2282 return FALSE;
2283 }
2284
2285 /* Determine whether unqualified senders or recipients are permitted
2286 for this host. Unfortunately, we have to do this every time, in order to
2287 set the flags so that they can be inspected when considering qualifying
2288 addresses in the headers. For a site that permits no qualification, this
2289 won't take long, however. */
2290
2291 allow_unqualified_sender =
2292 verify_check_host(&sender_unqualified_hosts) == OK;
2293
2294 allow_unqualified_recipient =
2295 verify_check_host(&recipient_unqualified_hosts) == OK;
2296
2297 /* Determine whether HELO/EHLO is required for this host. The requirement
2298 can be hard or soft. */
2299
2300 helo_required = verify_check_host(&helo_verify_hosts) == OK;
2301 if (!helo_required)
2302 helo_verify = verify_check_host(&helo_try_verify_hosts) == OK;
2303
2304 /* Determine whether this hosts is permitted to send syntactic junk
2305 after a HELO or EHLO command. */
2306
2307 helo_accept_junk = verify_check_host(&helo_accept_junk_hosts) == OK;
2308 }
2309
2310/* For batch SMTP input we are now done. */
2311
2312if (smtp_batched_input) return TRUE;
2313
a3c86431
TL
2314#ifdef EXPERIMENTAL_PROXY
2315/* If valid Proxy Protocol source is connecting, set up session.
2316 * Failure will not allow any SMTP function other than QUIT. */
2317proxy_session = FALSE;
2318proxy_session_failed = FALSE;
2319if (check_proxy_protocol_host())
2320 {
2321 if (setup_proxy_protocol_host() == FALSE)
2322 {
2323 proxy_session_failed = TRUE;
2324 DEBUG(D_receive)
2325 debug_printf("Failure to extract proxied host, only QUIT allowed\n");
2326 }
2327 else
2328 {
2329 sender_host_name = NULL;
2330 (void)host_name_lookup();
2331 host_build_sender_fullhost();
2332 }
2333 }
2334#endif
2335
059ec3d9
PH
2336/* Run the ACL if it exists */
2337
4e88a19f 2338user_msg = NULL;
059ec3d9
PH
2339if (acl_smtp_connect != NULL)
2340 {
2341 int rc;
64ffc24f 2342 rc = acl_check(ACL_WHERE_CONNECT, NULL, acl_smtp_connect, &user_msg,
059ec3d9
PH
2343 &log_msg);
2344 if (rc != OK)
2345 {
2346 (void)smtp_handle_acl_fail(ACL_WHERE_CONNECT, rc, user_msg, log_msg);
2347 return FALSE;
2348 }
2349 }
2350
2351/* Output the initial message for a two-way SMTP connection. It may contain
2352newlines, which then cause a multi-line response to be given. */
2353
4e88a19f
PH
2354code = US"220"; /* Default status code */
2355esc = US""; /* Default extended status code */
2356esclen = 0; /* Length of esc */
2357
2358if (user_msg == NULL)
2359 {
2360 s = expand_string(smtp_banner);
2361 if (s == NULL)
2362 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" (smtp_banner) "
2363 "failed: %s", smtp_banner, expand_string_message);
2364 }
2365else
2366 {
2367 int codelen = 3;
2368 s = user_msg;
2369 smtp_message_code(&code, &codelen, &s, NULL);
d6a96edc 2370 if (codelen > 4)
4e88a19f
PH
2371 {
2372 esc = code + 4;
2373 esclen = codelen - 4;
2374 }
2375 }
059ec3d9
PH
2376
2377/* Remove any terminating newlines; might as well remove trailing space too */
2378
2379p = s + Ustrlen(s);
2380while (p > s && isspace(p[-1])) p--;
2381*p = 0;
2382
2383/* It seems that CC:Mail is braindead, and assumes that the greeting message
2384is all contained in a single IP packet. The original code wrote out the
2385greeting using several calls to fprint/fputc, and on busy servers this could
2386cause it to be split over more than one packet - which caused CC:Mail to fall
2387over when it got the second part of the greeting after sending its first
2388command. Sigh. To try to avoid this, build the complete greeting message
2389first, and output it in one fell swoop. This gives a better chance of it
2390ending up as a single packet. */
2391
2392ss = store_get(size);
2393ptr = 0;
2394
2395p = s;
2396do /* At least once, in case we have an empty string */
2397 {
2398 int len;
2399 uschar *linebreak = Ustrchr(p, '\n');
4e88a19f 2400 ss = string_cat(ss, &size, &ptr, code, 3);
059ec3d9
PH
2401 if (linebreak == NULL)
2402 {
2403 len = Ustrlen(p);
4e88a19f 2404 ss = string_cat(ss, &size, &ptr, US" ", 1);
059ec3d9
PH
2405 }
2406 else
2407 {
2408 len = linebreak - p;
4e88a19f 2409 ss = string_cat(ss, &size, &ptr, US"-", 1);
059ec3d9 2410 }
4e88a19f 2411 ss = string_cat(ss, &size, &ptr, esc, esclen);
059ec3d9
PH
2412 ss = string_cat(ss, &size, &ptr, p, len);
2413 ss = string_cat(ss, &size, &ptr, US"\r\n", 2);
2414 p += len;
2415 if (linebreak != NULL) p++;
2416 }
2417while (*p != 0);
2418
2419ss[ptr] = 0; /* string_cat leaves room for this */
2420
2421/* Before we write the banner, check that there is no input pending, unless
2422this synchronisation check is disabled. */
2423
a14e5636 2424if (!check_sync())
059ec3d9 2425 {
a14e5636
PH
2426 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol "
2427 "synchronization error (input sent without waiting for greeting): "
2428 "rejected connection from %s input=\"%s\"", host_and_ident(TRUE),
2429 string_printing(smtp_inptr));
2430 smtp_printf("554 SMTP synchronization error\r\n");
2431 return FALSE;
059ec3d9
PH
2432 }
2433
2434/* Now output the banner */
2435
2436smtp_printf("%s", ss);
2437return TRUE;
2438}
2439
2440
2441
2442
2443
2444/*************************************************
2445* Handle SMTP syntax and protocol errors *
2446*************************************************/
2447
2448/* Write to the log for SMTP syntax errors in incoming commands, if configured
2449to do so. Then transmit the error response. The return value depends on the
2450number of syntax and protocol errors in this SMTP session.
2451
2452Arguments:
2453 type error type, given as a log flag bit
2454 code response code; <= 0 means don't send a response
2455 data data to reflect in the response (can be NULL)
2456 errmess the error message
2457
2458Returns: -1 limit of syntax/protocol errors NOT exceeded
2459 +1 limit of syntax/protocol errors IS exceeded
2460
2461These values fit in with the values of the "done" variable in the main
2462processing loop in smtp_setup_msg(). */
2463
2464static int
2465synprot_error(int type, int code, uschar *data, uschar *errmess)
2466{
2467int yield = -1;
2468
2469log_write(type, LOG_MAIN, "SMTP %s error in \"%s\" %s %s",
2470 (type == L_smtp_syntax_error)? "syntax" : "protocol",
3ee512ff 2471 string_printing(smtp_cmd_buffer), host_and_ident(TRUE), errmess);
059ec3d9
PH
2472
2473if (++synprot_error_count > smtp_max_synprot_errors)
2474 {
2475 yield = 1;
2476 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
2477 "syntax or protocol errors (last command was \"%s\")",
0ebc4d69 2478 host_and_ident(FALSE), string_printing(smtp_cmd_buffer));
059ec3d9
PH
2479 }
2480
2481if (code > 0)
2482 {
2483 smtp_printf("%d%c%s%s%s\r\n", code, (yield == 1)? '-' : ' ',
2484 (data == NULL)? US"" : data, (data == NULL)? US"" : US": ", errmess);
2485 if (yield == 1)
2486 smtp_printf("%d Too many syntax or protocol errors\r\n", code);
2487 }
2488
2489return yield;
2490}
2491
2492
2493
2494
2495/*************************************************
2496* Log incomplete transactions *
2497*************************************************/
2498
2499/* This function is called after a transaction has been aborted by RSET, QUIT,
2500connection drops or other errors. It logs the envelope information received
2501so far in order to preserve address verification attempts.
2502
2503Argument: string to indicate what aborted the transaction
2504Returns: nothing
2505*/
2506
2507static void
2508incomplete_transaction_log(uschar *what)
2509{
2510if (sender_address == NULL || /* No transaction in progress */
2511 (log_write_selector & L_smtp_incomplete_transaction) == 0 /* Not logging */
2512 ) return;
2513
2514/* Build list of recipients for logging */
2515
2516if (recipients_count > 0)
2517 {
2518 int i;
2519 raw_recipients = store_get(recipients_count * sizeof(uschar *));
2520 for (i = 0; i < recipients_count; i++)
2521 raw_recipients[i] = recipients_list[i].address;
2522 raw_recipients_count = recipients_count;
2523 }
2524
2525log_write(L_smtp_incomplete_transaction, LOG_MAIN|LOG_SENDER|LOG_RECIPIENTS,
2526 "%s incomplete transaction (%s)", host_and_ident(TRUE), what);
2527}
2528
2529
2530
2531
2532/*************************************************
2533* Send SMTP response, possibly multiline *
2534*************************************************/
2535
2536/* There are, it seems, broken clients out there that cannot handle multiline
2537responses. If no_multiline_responses is TRUE (it can be set from an ACL), we
2538output nothing for non-final calls, and only the first line for anything else.
2539
2540Arguments:
a5bd321b 2541 code SMTP code, may involve extended status codes
d6a96edc 2542 codelen length of smtp code; if > 4 there's an ESC
059ec3d9
PH
2543 final FALSE if the last line isn't the final line
2544 msg message text, possibly containing newlines
2545
2546Returns: nothing
2547*/
2548
2549void
a5bd321b 2550smtp_respond(uschar* code, int codelen, BOOL final, uschar *msg)
059ec3d9 2551{
a5bd321b
PH
2552int esclen = 0;
2553uschar *esc = US"";
2554
059ec3d9
PH
2555if (!final && no_multiline_responses) return;
2556
d6a96edc 2557if (codelen > 4)
a5bd321b
PH
2558 {
2559 esc = code + 4;
2560 esclen = codelen - 4;
2561 }
2562
2679d413
PH
2563/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
2564have had the same. Note: this code is also present in smtp_printf(). It would
2565be tidier to have it only in one place, but when it was added, it was easier to
2566do it that way, so as not to have to mess with the code for the RCPT command,
2567which sometimes uses smtp_printf() and sometimes smtp_respond(). */
2568
2569if (rcpt_in_progress)
2570 {
2571 if (rcpt_smtp_response == NULL)
2572 rcpt_smtp_response = string_copy(msg);
2573 else if (rcpt_smtp_response_same &&
2574 Ustrcmp(rcpt_smtp_response, msg) != 0)
2575 rcpt_smtp_response_same = FALSE;
2576 rcpt_in_progress = FALSE;
2577 }
2578
2579/* Not output the message, splitting it up into multiple lines if necessary. */
2580
059ec3d9
PH
2581for (;;)
2582 {
2583 uschar *nl = Ustrchr(msg, '\n');
2584 if (nl == NULL)
2585 {
a5bd321b 2586 smtp_printf("%.3s%c%.*s%s\r\n", code, final? ' ':'-', esclen, esc, msg);
059ec3d9
PH
2587 return;
2588 }
2589 else if (nl[1] == 0 || no_multiline_responses)
2590 {
a5bd321b
PH
2591 smtp_printf("%.3s%c%.*s%.*s\r\n", code, final? ' ':'-', esclen, esc,
2592 (int)(nl - msg), msg);
059ec3d9
PH
2593 return;
2594 }
2595 else
2596 {
a5bd321b 2597 smtp_printf("%.3s-%.*s%.*s\r\n", code, esclen, esc, (int)(nl - msg), msg);
059ec3d9
PH
2598 msg = nl + 1;
2599 while (isspace(*msg)) msg++;
2600 }
2601 }
2602}
2603
2604
2605
2606
2607/*************************************************
4e88a19f
PH
2608* Parse user SMTP message *
2609*************************************************/
2610
2611/* This function allows for user messages overriding the response code details
2612by providing a suitable response code string at the start of the message
2613user_msg. Check the message for starting with a response code and optionally an
2614extended status code. If found, check that the first digit is valid, and if so,
2615change the code pointer and length to use the replacement. An invalid code
2616causes a panic log; in this case, if the log messages is the same as the user
2617message, we must also adjust the value of the log message to show the code that
2618is actually going to be used (the original one).
2619
2620This function is global because it is called from receive.c as well as within
2621this module.
2622
d6a96edc
PH
2623Note that the code length returned includes the terminating whitespace
2624character, which is always included in the regex match.
2625
4e88a19f
PH
2626Arguments:
2627 code SMTP code, may involve extended status codes
d6a96edc 2628 codelen length of smtp code; if > 4 there's an ESC
4e88a19f
PH
2629 msg message text
2630 log_msg optional log message, to be adjusted with the new SMTP code
2631
2632Returns: nothing
2633*/
2634
2635void
2636smtp_message_code(uschar **code, int *codelen, uschar **msg, uschar **log_msg)
2637{
2638int n;
2639int ovector[3];
2640
2641if (msg == NULL || *msg == NULL) return;
2642
2643n = pcre_exec(regex_smtp_code, NULL, CS *msg, Ustrlen(*msg), 0,
2644 PCRE_EOPT, ovector, sizeof(ovector)/sizeof(int));
2645if (n < 0) return;
2646
2647if ((*msg)[0] != (*code)[0])
2648 {
2649 log_write(0, LOG_MAIN|LOG_PANIC, "configured error code starts with "
2650 "incorrect digit (expected %c) in \"%s\"", (*code)[0], *msg);
2651 if (log_msg != NULL && *log_msg == *msg)
2652 *log_msg = string_sprintf("%s %s", *code, *log_msg + ovector[1]);
2653 }
2654else
2655 {
2656 *code = *msg;
2657 *codelen = ovector[1]; /* Includes final space */
2658 }
2659*msg += ovector[1]; /* Chop the code off the message */
2660return;
2661}
2662
2663
2664
2665
2666/*************************************************
059ec3d9
PH
2667* Handle an ACL failure *
2668*************************************************/
2669
2670/* This function is called when acl_check() fails. As well as calls from within
2671this module, it is called from receive.c for an ACL after DATA. It sorts out
2672logging the incident, and sets up the error response. A message containing
2673newlines is turned into a multiline SMTP response, but for logging, only the
2674first line is used.
2675
a5bd321b
PH
2676There's a table of default permanent failure response codes to use in
2677globals.c, along with the table of names. VFRY is special. Despite RFC1123 it
2678defaults disabled in Exim. However, discussion in connection with RFC 821bis
2679(aka RFC 2821) has concluded that the response should be 252 in the disabled
2680state, because there are broken clients that try VRFY before RCPT. A 5xx
2681response should be given only when the address is positively known to be
2682undeliverable. Sigh. Also, for ETRN, 458 is given on refusal, and for AUTH,
2683503.
2684
2685From Exim 4.63, it is possible to override the response code details by
2686providing a suitable response code string at the start of the message provided
2687in user_msg. The code's first digit is checked for validity.
059ec3d9
PH
2688
2689Arguments:
2690 where where the ACL was called from
2691 rc the failure code
2692 user_msg a message that can be included in an SMTP response
2693 log_msg a message for logging
2694
2695Returns: 0 in most cases
2696 2 if the failure code was FAIL_DROP, in which case the
2697 SMTP connection should be dropped (this value fits with the
2698 "done" variable in smtp_setup_msg() below)
2699*/
2700
2701int
2702smtp_handle_acl_fail(int where, int rc, uschar *user_msg, uschar *log_msg)
2703{
059ec3d9 2704BOOL drop = rc == FAIL_DROP;
a5bd321b 2705int codelen = 3;
a5bd321b 2706uschar *smtp_code;
059ec3d9
PH
2707uschar *lognl;
2708uschar *sender_info = US"";
64ffc24f 2709uschar *what =
8523533c 2710#ifdef WITH_CONTENT_SCAN
64ffc24f 2711 (where == ACL_WHERE_MIME)? US"during MIME ACL checks" :
8e669ac1 2712#endif
64ffc24f
PH
2713 (where == ACL_WHERE_PREDATA)? US"DATA" :
2714 (where == ACL_WHERE_DATA)? US"after DATA" :
8ccd00b1 2715#ifndef DISABLE_PRDR
fd98a5c6
JH
2716 (where == ACL_WHERE_PRDR)? US"after DATA PRDR" :
2717#endif
ca86f471 2718 (smtp_cmd_data == NULL)?
64ffc24f 2719 string_sprintf("%s in \"connect\" ACL", acl_wherenames[where]) :
ca86f471 2720 string_sprintf("%s %s", acl_wherenames[where], smtp_cmd_data);
059ec3d9
PH
2721
2722if (drop) rc = FAIL;
2723
4e88a19f 2724/* Set the default SMTP code, and allow a user message to change it. */
a5bd321b
PH
2725
2726smtp_code = (rc != FAIL)? US"451" : acl_wherecodes[where];
4e88a19f 2727smtp_message_code(&smtp_code, &codelen, &user_msg, &log_msg);
a5bd321b 2728
059ec3d9
PH
2729/* We used to have sender_address here; however, there was a bug that was not
2730updating sender_address after a rewrite during a verify. When this bug was
2731fixed, sender_address at this point became the rewritten address. I'm not sure
2732this is what should be logged, so I've changed to logging the unrewritten
2733address to retain backward compatibility. */
2734
8523533c 2735#ifndef WITH_CONTENT_SCAN
059ec3d9 2736if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA)
8523533c
TK
2737#else
2738if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA || where == ACL_WHERE_MIME)
2739#endif
059ec3d9 2740 {
b98bb9ac
PP
2741 sender_info = string_sprintf("F=<%s>%s%s%s%s ",
2742 sender_address_unrewritten ? sender_address_unrewritten : sender_address,
2743 sender_host_authenticated ? US" A=" : US"",
2744 sender_host_authenticated ? sender_host_authenticated : US"",
2745 sender_host_authenticated && authenticated_id ? US":" : US"",
2746 sender_host_authenticated && authenticated_id ? authenticated_id : US""
2747 );
059ec3d9
PH
2748 }
2749
2750/* If there's been a sender verification failure with a specific message, and
2751we have not sent a response about it yet, do so now, as a preliminary line for
278c6e6c
PH
2752failures, but not defers. However, always log it for defer, and log it for fail
2753unless the sender_verify_fail log selector has been turned off. */
059ec3d9
PH
2754
2755if (sender_verified_failed != NULL &&
2756 !testflag(sender_verified_failed, af_sverify_told))
2757 {
2679d413
PH
2758 BOOL save_rcpt_in_progress = rcpt_in_progress;
2759 rcpt_in_progress = FALSE; /* So as not to treat these as the error */
2760
059ec3d9
PH
2761 setflag(sender_verified_failed, af_sverify_told);
2762
278c6e6c
PH
2763 if (rc != FAIL || (log_extra_selector & LX_sender_verify_fail) != 0)
2764 log_write(0, LOG_MAIN|LOG_REJECT, "%s sender verify %s for <%s>%s",
2765 host_and_ident(TRUE),
2766 ((sender_verified_failed->special_action & 255) == DEFER)? "defer":"fail",
2767 sender_verified_failed->address,
2768 (sender_verified_failed->message == NULL)? US"" :
2769 string_sprintf(": %s", sender_verified_failed->message));
059ec3d9
PH
2770
2771 if (rc == FAIL && sender_verified_failed->user_message != NULL)
a5bd321b 2772 smtp_respond(smtp_code, codelen, FALSE, string_sprintf(
059ec3d9
PH
2773 testflag(sender_verified_failed, af_verify_pmfail)?
2774 "Postmaster verification failed while checking <%s>\n%s\n"
2775 "Several RFCs state that you are required to have a postmaster\n"
2776 "mailbox for each mail domain. This host does not accept mail\n"
2777 "from domains whose servers reject the postmaster address."
2778 :
2779 testflag(sender_verified_failed, af_verify_nsfail)?
2780 "Callback setup failed while verifying <%s>\n%s\n"
2781 "The initial connection, or a HELO or MAIL FROM:<> command was\n"
2782 "rejected. Refusing MAIL FROM:<> does not help fight spam, disregards\n"
2783 "RFC requirements, and stops you from receiving standard bounce\n"
2784 "messages. This host does not accept mail from domains whose servers\n"
2785 "refuse bounces."
2786 :
2787 "Verification failed for <%s>\n%s",
2788 sender_verified_failed->address,
2789 sender_verified_failed->user_message));
2679d413
PH
2790
2791 rcpt_in_progress = save_rcpt_in_progress;
059ec3d9
PH
2792 }
2793
2794/* Sort out text for logging */
2795
2796log_msg = (log_msg == NULL)? US"" : string_sprintf(": %s", log_msg);
2797lognl = Ustrchr(log_msg, '\n');
2798if (lognl != NULL) *lognl = 0;
2799
2800/* Send permanent failure response to the command, but the code used isn't
2801always a 5xx one - see comments at the start of this function. If the original
2802rc was FAIL_DROP we drop the connection and yield 2. */
2803
a5bd321b 2804if (rc == FAIL) smtp_respond(smtp_code, codelen, TRUE, (user_msg == NULL)?
059ec3d9
PH
2805 US"Administrative prohibition" : user_msg);
2806
2807/* Send temporary failure response to the command. Don't give any details,
2808unless acl_temp_details is set. This is TRUE for a callout defer, a "defer"
2809verb, and for a header verify when smtp_return_error_details is set.
2810
2811This conditional logic is all somewhat of a mess because of the odd
2812interactions between temp_details and return_error_details. One day it should
2813be re-implemented in a tidier fashion. */
2814
2815else
2816 {
2817 if (acl_temp_details && user_msg != NULL)
2818 {
2819 if (smtp_return_error_details &&
2820 sender_verified_failed != NULL &&
2821 sender_verified_failed->message != NULL)
2822 {
a5bd321b 2823 smtp_respond(smtp_code, codelen, FALSE, sender_verified_failed->message);
059ec3d9 2824 }
a5bd321b 2825 smtp_respond(smtp_code, codelen, TRUE, user_msg);
059ec3d9
PH
2826 }
2827 else
a5bd321b
PH
2828 smtp_respond(smtp_code, codelen, TRUE,
2829 US"Temporary local problem - please try later");
059ec3d9
PH
2830 }
2831
6ea85e9a
PH
2832/* Log the incident to the logs that are specified by log_reject_target
2833(default main, reject). This can be empty to suppress logging of rejections. If
2834the connection is not forcibly to be dropped, return 0. Otherwise, log why it
2835is closing if required and return 2. */
059ec3d9 2836
6ea85e9a 2837if (log_reject_target != 0)
887291d2 2838 {
e45a1c37 2839#ifdef SUPPORT_TLS
887291d2
JH
2840 uschar * s = s_tlslog(NULL, NULL, NULL);
2841 if (!s) s = US"";
e45a1c37 2842#else
887291d2 2843 uschar * s = US"";
e45a1c37 2844#endif
887291d2
JH
2845 log_write(0, log_reject_target, "%s%s %s%srejected %s%s",
2846 host_and_ident(TRUE), s,
6ea85e9a 2847 sender_info, (rc == FAIL)? US"" : US"temporarily ", what, log_msg);
887291d2 2848 }
059ec3d9
PH
2849
2850if (!drop) return 0;
2851
2852log_write(L_smtp_connection, LOG_MAIN, "%s closed by DROP in ACL",
2853 smtp_get_connection_info());
8f128379
PH
2854
2855/* Run the not-quit ACL, but without any custom messages. This should not be a
2856problem, because we get here only if some other ACL has issued "drop", and
2857in that case, *its* custom messages will have been used above. */
2858
2859smtp_notquit_exit(US"acl-drop", NULL, NULL);
059ec3d9
PH
2860return 2;
2861}
2862
2863
2864
2865
2866/*************************************************
8f128379
PH
2867* Handle SMTP exit when QUIT is not given *
2868*************************************************/
2869
2870/* This function provides a logging/statistics hook for when an SMTP connection
2871is dropped on the floor or the other end goes away. It's a global function
2872because it's called from receive.c as well as this module. As well as running
2873the NOTQUIT ACL, if there is one, this function also outputs a final SMTP
2874response, either with a custom message from the ACL, or using a default. There
2875is one case, however, when no message is output - after "drop". In that case,
2876the ACL that obeyed "drop" has already supplied the custom message, and NULL is
2877passed to this function.
2878
2879In case things go wrong while processing this function, causing an error that
2880may re-enter this funtion, there is a recursion check.
2881
2882Arguments:
2883 reason What $smtp_notquit_reason will be set to in the ACL;
2884 if NULL, the ACL is not run
2885 code The error code to return as part of the response
2886 defaultrespond The default message if there's no user_msg
2887
2888Returns: Nothing
2889*/
2890
2891void
2892smtp_notquit_exit(uschar *reason, uschar *code, uschar *defaultrespond, ...)
2893{
2894int rc;
2895uschar *user_msg = NULL;
2896uschar *log_msg = NULL;
2897
2898/* Check for recursive acll */
2899
2900if (smtp_exit_function_called)
2901 {
2902 log_write(0, LOG_PANIC, "smtp_notquit_exit() called more than once (%s)",
2903 reason);
2904 return;
2905 }
2906smtp_exit_function_called = TRUE;
2907
2908/* Call the not-QUIT ACL, if there is one, unless no reason is given. */
2909
2910if (acl_smtp_notquit != NULL && reason != NULL)
2911 {
2912 smtp_notquit_reason = reason;
2913 rc = acl_check(ACL_WHERE_NOTQUIT, NULL, acl_smtp_notquit, &user_msg,
2914 &log_msg);
2915 if (rc == ERROR)
2916 log_write(0, LOG_MAIN|LOG_PANIC, "ACL for not-QUIT returned ERROR: %s",
2917 log_msg);
2918 }
2919
2920/* Write an SMTP response if we are expected to give one. As the default
2921responses are all internal, they should always fit in the buffer, but code a
2922warning, just in case. Note that string_vformat() still leaves a complete
2923string, even if it is incomplete. */
2924
2925if (code != NULL && defaultrespond != NULL)
2926 {
2927 if (user_msg == NULL)
2928 {
2929 uschar buffer[128];
2930 va_list ap;
2931 va_start(ap, defaultrespond);
2932 if (!string_vformat(buffer, sizeof(buffer), CS defaultrespond, ap))
2933 log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_notquit_exit()");
2934 smtp_printf("%s %s\r\n", code, buffer);
2935 va_end(ap);
2936 }
2937 else
2938 smtp_respond(code, 3, TRUE, user_msg);
2939 mac_smtp_fflush();
2940 }
2941}
2942
2943
2944
2945
2946/*************************************************
d7b47fd0
PH
2947* Verify HELO argument *
2948*************************************************/
2949
2950/* This function is called if helo_verify_hosts or helo_try_verify_hosts is
2951matched. It is also called from ACL processing if verify = helo is used and
2952verification was not previously tried (i.e. helo_try_verify_hosts was not
2953matched). The result of its processing is to set helo_verified and
2954helo_verify_failed. These variables should both be FALSE for this function to
2955be called.
2956
2957Note that EHLO/HELO is legitimately allowed to quote an address literal. Allow
2958for IPv6 ::ffff: literals.
2959
2960Argument: none
2961Returns: TRUE if testing was completed;
2962 FALSE on a temporary failure
2963*/
2964
2965BOOL
2966smtp_verify_helo(void)
2967{
2968BOOL yield = TRUE;
2969
2970HDEBUG(D_receive) debug_printf("verifying EHLO/HELO argument \"%s\"\n",
2971 sender_helo_name);
2972
2973if (sender_helo_name == NULL)
2974 {
2975 HDEBUG(D_receive) debug_printf("no EHLO/HELO command was issued\n");
2976 }
2977
d1d5595c
PH
2978/* Deal with the case of -bs without an IP address */
2979
2980else if (sender_host_address == NULL)
2981 {
2982 HDEBUG(D_receive) debug_printf("no client IP address: assume success\n");
2983 helo_verified = TRUE;
2984 }
2985
2986/* Deal with the more common case when there is a sending IP address */
2987
d7b47fd0
PH
2988else if (sender_helo_name[0] == '[')
2989 {
2990 helo_verified = Ustrncmp(sender_helo_name+1, sender_host_address,
2991 Ustrlen(sender_host_address)) == 0;
2992
2993 #if HAVE_IPV6
2994 if (!helo_verified)
2995 {
2996 if (strncmpic(sender_host_address, US"::ffff:", 7) == 0)
2997 helo_verified = Ustrncmp(sender_helo_name + 1,
2998 sender_host_address + 7, Ustrlen(sender_host_address) - 7) == 0;
2999 }
3000 #endif
3001
3002 HDEBUG(D_receive)
3003 { if (helo_verified) debug_printf("matched host address\n"); }
3004 }
3005
3006/* Do a reverse lookup if one hasn't already given a positive or negative
3007response. If that fails, or the name doesn't match, try checking with a forward
3008lookup. */
3009
3010else
3011 {
3012 if (sender_host_name == NULL && !host_lookup_failed)
3013 yield = host_name_lookup() != DEFER;
3014
3015 /* If a host name is known, check it and all its aliases. */
3016
1705dd20
JH
3017 if (sender_host_name)
3018 if ((helo_verified = strcmpic(sender_host_name, sender_helo_name) == 0))
d7b47fd0 3019 {
1705dd20 3020 sender_helo_dnssec = sender_host_dnssec;
d7b47fd0
PH
3021 HDEBUG(D_receive) debug_printf("matched host name\n");
3022 }
3023 else
3024 {
3025 uschar **aliases = sender_host_aliases;
1705dd20
JH
3026 while (*aliases)
3027 if ((helo_verified = strcmpic(*aliases++, sender_helo_name) == 0))
3028 {
3029 sender_helo_dnssec = sender_host_dnssec;
3030 break;
3031 }
3032
3033 HDEBUG(D_receive) if (helo_verified)
d7b47fd0 3034 debug_printf("matched alias %s\n", *(--aliases));
d7b47fd0 3035 }
d7b47fd0
PH
3036
3037 /* Final attempt: try a forward lookup of the helo name */
3038
3039 if (!helo_verified)
3040 {
3041 int rc;
3042 host_item h;
1705dd20
JH
3043 dnssec_domains d;
3044 host_item *hh;
3045
d7b47fd0
PH
3046 h.name = sender_helo_name;
3047 h.address = NULL;
3048 h.mx = MX_NONE;
3049 h.next = NULL;
1705dd20
JH
3050 d.request = US"*";
3051 d.require = US"";
3052
d7b47fd0
PH
3053 HDEBUG(D_receive) debug_printf("getting IP address for %s\n",
3054 sender_helo_name);
1705dd20
JH
3055 rc = host_find_bydns(&h, NULL, HOST_FIND_BY_A,
3056 NULL, NULL, NULL, &d, NULL, NULL);
d7b47fd0 3057 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
1705dd20 3058 for (hh = &h; hh; hh = hh->next)
d7b47fd0
PH
3059 if (Ustrcmp(hh->address, sender_host_address) == 0)
3060 {
3061 helo_verified = TRUE;
1705dd20 3062 if (h.dnssec == DS_YES) sender_helo_dnssec = TRUE;
d7b47fd0 3063 HDEBUG(D_receive)
1705dd20
JH
3064 {
3065 debug_printf("IP address for %s matches calling address\n"
3066 "Forward DNS security status: %sverified\n",
3067 sender_helo_name, sender_helo_dnssec ? "" : "un");
3068 }
d7b47fd0
PH
3069 break;
3070 }
d7b47fd0
PH
3071 }
3072 }
3073
d1d5595c 3074if (!helo_verified) helo_verify_failed = TRUE; /* We've tried ... */
d7b47fd0
PH
3075return yield;
3076}
3077
3078
3079
3080
3081/*************************************************
4e88a19f
PH
3082* Send user response message *
3083*************************************************/
3084
3085/* This function is passed a default response code and a user message. It calls
3086smtp_message_code() to check and possibly modify the response code, and then
3087calls smtp_respond() to transmit the response. I put this into a function
3088just to avoid a lot of repetition.
3089
3090Arguments:
3091 code the response code
3092 user_msg the user message
3093
3094Returns: nothing
3095*/
3096
3097static void
3098smtp_user_msg(uschar *code, uschar *user_msg)
3099{
3100int len = 3;
3101smtp_message_code(&code, &len, &user_msg, NULL);
3102smtp_respond(code, len, TRUE, user_msg);
3103}
3104
3105
3106
b3ef41c9
JH
3107static int
3108smtp_in_auth(auth_instance *au, uschar ** s, uschar ** ss)
3109{
3110const uschar *set_id = NULL;
3111int rc, i;
3112
3113/* Run the checking code, passing the remainder of the command line as
3114data. Initials the $auth<n> variables as empty. Initialize $0 empty and set
3115it as the only set numerical variable. The authenticator may set $auth<n>
3116and also set other numeric variables. The $auth<n> variables are preferred
3117nowadays; the numerical variables remain for backwards compatibility.
3118
3119Afterwards, have a go at expanding the set_id string, even if
3120authentication failed - for bad passwords it can be useful to log the
3121userid. On success, require set_id to expand and exist, and put it in
3122authenticated_id. Save this in permanent store, as the working store gets
3123reset at HELO, RSET, etc. */
3124
3125for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL;
3126expand_nmax = 0;
3127expand_nlength[0] = 0; /* $0 contains nothing */
3128
3129rc = (au->info->servercode)(au, smtp_cmd_data);
3130if (au->set_id) set_id = expand_string(au->set_id);
3131expand_nmax = -1; /* Reset numeric variables */
3132for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL; /* Reset $auth<n> */
3133
3134/* The value of authenticated_id is stored in the spool file and printed in
3135log lines. It must not contain binary zeros or newline characters. In
3136normal use, it never will, but when playing around or testing, this error
3137can (did) happen. To guard against this, ensure that the id contains only
3138printing characters. */
3139
3140if (set_id) set_id = string_printing(set_id);
3141
3142/* For the non-OK cases, set up additional logging data if set_id
3143is not empty. */
3144
3145if (rc != OK)
3146 set_id = set_id && *set_id
3147 ? string_sprintf(" (set_id=%s)", set_id) : US"";
3148
3149/* Switch on the result */
3150
3151switch(rc)
3152 {
3153 case OK:
3154 if (!au->set_id || set_id) /* Complete success */
3155 {
3156 if (set_id) authenticated_id = string_copy_malloc(set_id);
3157 sender_host_authenticated = au->name;
3158 authentication_failed = FALSE;
3159 authenticated_fail_id = NULL; /* Impossible to already be set? */
3160
3161 received_protocol =
3162 (sender_host_address ? protocols : protocols_local)
3163 [pextend + pauthed + (tls_in.active >= 0 ? pcrpted:0)];
3164 *s = *ss = US"235 Authentication succeeded";
3165 authenticated_by = au;
3166 break;
3167 }
3168
3169 /* Authentication succeeded, but we failed to expand the set_id string.
3170 Treat this as a temporary error. */
3171
3172 auth_defer_msg = expand_string_message;
3173 /* Fall through */
3174
3175 case DEFER:
3176 if (set_id) authenticated_fail_id = string_copy_malloc(set_id);
3177 *s = string_sprintf("435 Unable to authenticate at present%s",
3178 auth_defer_user_msg);
3179 *ss = string_sprintf("435 Unable to authenticate at present%s: %s",
3180 set_id, auth_defer_msg);
3181 break;
3182
3183 case BAD64:
3184 *s = *ss = US"501 Invalid base64 data";
3185 break;
3186
3187 case CANCELLED:
3188 *s = *ss = US"501 Authentication cancelled";
3189 break;
3190
3191 case UNEXPECTED:
3192 *s = *ss = US"553 Initial data not expected";
3193 break;
3194
3195 case FAIL:
3196 if (set_id) authenticated_fail_id = string_copy_malloc(set_id);
3197 *s = US"535 Incorrect authentication data";
3198 *ss = string_sprintf("535 Incorrect authentication data%s", set_id);
3199 break;
3200
3201 default:
3202 if (set_id) authenticated_fail_id = string_copy_malloc(set_id);
3203 *s = US"435 Internal error";
3204 *ss = string_sprintf("435 Internal error%s: return %d from authentication "
3205 "check", set_id, rc);
3206 break;
3207 }
3208
3209return rc;
3210}
3211
3212
3213
4e88a19f 3214/*************************************************
059ec3d9
PH
3215* Initialize for SMTP incoming message *
3216*************************************************/
3217
3218/* This function conducts the initial dialogue at the start of an incoming SMTP
3219message, and builds a list of recipients. However, if the incoming message
3220is part of a batch (-bS option) a separate function is called since it would
3221be messy having tests splattered about all over this function. This function
3222therefore handles the case where interaction is occurring. The input and output
3223files are set up in smtp_in and smtp_out.
3224
3225The global recipients_list is set to point to a vector of recipient_item
3226blocks, whose number is given by recipients_count. This is extended by the
3227receive_add_recipient() function. The global variable sender_address is set to
3228the sender's address. The yield is +1 if a message has been successfully
3229started, 0 if a QUIT command was encountered or the connection was refused from
3230the particular host, or -1 if the connection was lost.
3231
3232Argument: none
3233
3234Returns: > 0 message successfully started (reached DATA)
3235 = 0 QUIT read or end of file reached or call refused
3236 < 0 lost connection
3237*/
3238
3239int
3240smtp_setup_msg(void)
3241{
3242int done = 0;
3243BOOL toomany = FALSE;
3244BOOL discarded = FALSE;
3245BOOL last_was_rej_mail = FALSE;
3246BOOL last_was_rcpt = FALSE;
3247void *reset_point = store_get(0);
3248
3249DEBUG(D_receive) debug_printf("smtp_setup_msg entered\n");
3250
3251/* Reset for start of new message. We allow one RSET not to be counted as a
3252nonmail command, for those MTAs that insist on sending it between every
3253message. Ditto for EHLO/HELO and for STARTTLS, to allow for going in and out of
3254TLS between messages (an Exim client may do this if it has messages queued up
3255for the host). Note: we do NOT reset AUTH at this point. */
3256
3257smtp_reset(reset_point);
3258message_ended = END_NOTSTARTED;
3259
3260cmd_list[CMD_LIST_RSET].is_mail_cmd = TRUE;
3261cmd_list[CMD_LIST_HELO].is_mail_cmd = TRUE;
3262cmd_list[CMD_LIST_EHLO].is_mail_cmd = TRUE;
3263#ifdef SUPPORT_TLS
3264cmd_list[CMD_LIST_STARTTLS].is_mail_cmd = TRUE;
b3ef41c9 3265cmd_list[CMD_LIST_TLS_AUTH].is_mail_cmd = TRUE;
059ec3d9
PH
3266#endif
3267
3268/* Set the local signal handler for SIGTERM - it tries to end off tidily */
3269
3270os_non_restarting_signal(SIGTERM, command_sigterm_handler);
3271
3272/* Batched SMTP is handled in a different function. */
3273
3274if (smtp_batched_input) return smtp_setup_batch_msg();
3275
3276/* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
3277value. The values are 2 larger than the required yield of the function. */
3278
3279while (done <= 0)
3280 {
55414b25 3281 const uschar **argv;
059ec3d9
PH
3282 uschar *etrn_command;
3283 uschar *etrn_serialize_key;
3284 uschar *errmess;
4e88a19f
PH
3285 uschar *log_msg, *smtp_code;
3286 uschar *user_msg = NULL;
059ec3d9
PH
3287 uschar *recipient = NULL;
3288 uschar *hello = NULL;
059ec3d9
PH
3289 uschar *s, *ss;
3290 BOOL was_rej_mail = FALSE;
3291 BOOL was_rcpt = FALSE;
3292 void (*oldsignal)(int);
3293 pid_t pid;
3294 int start, end, sender_domain, recipient_domain;
3295 int ptr, size, rc;
f78eb7c6 3296 int c, i;
059ec3d9 3297 auth_instance *au;
6c1c3d1d
WB
3298 uschar *orcpt = NULL;
3299 int flags;
059ec3d9 3300
b3ef41c9
JH
3301#if defined(SUPPORT_TLS) && defined(AUTH_TLS)
3302 /* Check once per STARTTLS or SSL-on-connect for a TLS AUTH */
3303 if ( tls_in.active >= 0
3304 && tls_in.peercert
3305 && tls_in.certificate_verified
3306 && cmd_list[CMD_LIST_TLS_AUTH].is_mail_cmd
3307 )
3308 {
3309 cmd_list[CMD_LIST_TLS_AUTH].is_mail_cmd = FALSE;
3310 if (acl_smtp_auth)
3311 {
3312 rc = acl_check(ACL_WHERE_AUTH, NULL, acl_smtp_auth, &user_msg, &log_msg);
3313 if (rc != OK)
3314 {
3315 done = smtp_handle_acl_fail(ACL_WHERE_AUTH, rc, user_msg, log_msg);
3316 continue;
3317 }
3318 }
3319
3320 for (au = auths; au; au = au->next)
3321 if (strcmpic(US"tls", au->driver_name) == 0)
3322 {
3323 smtp_cmd_data = NULL;
3324
3325 if ((c = smtp_in_auth(au, &s, &ss)) != OK)
3326 log_write(0, LOG_MAIN|LOG_REJECT, "%s authenticator failed for %s: %s",
3327 au->name, host_and_ident(FALSE), ss);
3328 else
3329 DEBUG(D_auth) debug_printf("tls auth succeeded\n");
3330
3331 break;
3332 }
3333 }
3334#endif
3335
059ec3d9
PH
3336 switch(smtp_read_command(TRUE))
3337 {
3338 /* The AUTH command is not permitted to occur inside a transaction, and may
c46782ef
PH
3339 occur successfully only once per connection. Actually, that isn't quite
3340 true. When TLS is started, all previous information about a connection must
3341 be discarded, so a new AUTH is permitted at that time.
3342
3343 AUTH may only be used when it has been advertised. However, it seems that
3344 there are clients that send AUTH when it hasn't been advertised, some of
3345 them even doing this after HELO. And there are MTAs that accept this. Sigh.
3346 So there's a get-out that allows this to happen.
059ec3d9
PH
3347
3348 AUTH is initially labelled as a "nonmail command" so that one occurrence
3349 doesn't get counted. We change the label here so that multiple failing
3350 AUTHS will eventually hit the nonmail threshold. */
3351
3352 case AUTH_CMD:
b4ed4da0 3353 HAD(SCH_AUTH);
059ec3d9
PH
3354 authentication_failed = TRUE;
3355 cmd_list[CMD_LIST_AUTH].is_mail_cmd = FALSE;
3356
c46782ef 3357 if (!auth_advertised && !allow_auth_unadvertised)
059ec3d9
PH
3358 {
3359 done = synprot_error(L_smtp_protocol_error, 503, NULL,
3360 US"AUTH command used when not advertised");
3361 break;
3362 }
b3ef41c9 3363 if (sender_host_authenticated)
059ec3d9
PH
3364 {
3365 done = synprot_error(L_smtp_protocol_error, 503, NULL,
3366 US"already authenticated");
3367 break;
3368 }
b3ef41c9 3369 if (sender_address)
059ec3d9
PH
3370 {
3371 done = synprot_error(L_smtp_protocol_error, 503, NULL,
3372 US"not permitted in mail transaction");
3373 break;
3374 }
3375
3376 /* Check the ACL */
3377
b3ef41c9 3378 if (acl_smtp_auth)
059ec3d9 3379 {
64ffc24f 3380 rc = acl_check(ACL_WHERE_AUTH, NULL, acl_smtp_auth, &user_msg, &log_msg);
059ec3d9
PH
3381 if (rc != OK)
3382 {
3383 done = smtp_handle_acl_fail(ACL_WHERE_AUTH, rc, user_msg, log_msg);
3384 break;
3385 }
3386 }
3387
3388 /* Find the name of the requested authentication mechanism. */
3389
ca86f471
PH
3390 s = smtp_cmd_data;
3391 while ((c = *smtp_cmd_data) != 0 && !isspace(c))
059ec3d9
PH
3392 {
3393 if (!isalnum(c) && c != '-' && c != '_')
3394 {
3395 done = synprot_error(L_smtp_syntax_error, 501, NULL,
3396 US"invalid character in authentication mechanism name");
3397 goto COMMAND_LOOP;
3398 }
ca86f471 3399 smtp_cmd_data++;
059ec3d9
PH
3400 }
3401
3402 /* If not at the end of the line, we must be at white space. Terminate the
3403 name and move the pointer on to any data that may be present. */
3404
ca86f471 3405 if (*smtp_cmd_data != 0)
059ec3d9 3406 {
ca86f471
PH
3407 *smtp_cmd_data++ = 0;
3408 while (isspace(*smtp_cmd_data)) smtp_cmd_data++;
059ec3d9
PH
3409 }
3410
3411 /* Search for an authentication mechanism which is configured for use
c46782ef
PH
3412 as a server and which has been advertised (unless, sigh, allow_auth_
3413 unadvertised is set). */
059ec3d9 3414
b3ef41c9 3415 for (au = auths; au; au = au->next)
059ec3d9 3416 if (strcmpic(s, au->public_name) == 0 && au->server &&
b3ef41c9
JH
3417 (au->advertised || allow_auth_unadvertised))
3418 break;
059ec3d9 3419
b3ef41c9 3420 if (au)
059ec3d9 3421 {
b3ef41c9 3422 c = smtp_in_auth(au, &s, &ss);
059ec3d9 3423
b3ef41c9
JH
3424 smtp_printf("%s\r\n", s);
3425 if (c != OK)
3426 log_write(0, LOG_MAIN|LOG_REJECT, "%s authenticator failed for %s: %s",
3427 au->name, host_and_ident(FALSE), ss);
059ec3d9 3428 }
b3ef41c9
JH
3429 else
3430 done = synprot_error(L_smtp_protocol_error, 504, NULL,
3431 string_sprintf("%s authentication mechanism not supported", s));
059ec3d9
PH
3432
3433 break; /* AUTH_CMD */
3434
3435 /* The HELO/EHLO commands are permitted to appear in the middle of a
3436 session as well as at the beginning. They have the effect of a reset in
3437 addition to their other functions. Their absence at the start cannot be
3438 taken to be an error.
3439
3440 RFC 2821 says:
3441
3442 If the EHLO command is not acceptable to the SMTP server, 501, 500,
3443 or 502 failure replies MUST be returned as appropriate. The SMTP
3444 server MUST stay in the same state after transmitting these replies
3445 that it was in before the EHLO was received.
3446
3447 Therefore, we do not do the reset until after checking the command for
3448 acceptability. This change was made for Exim release 4.11. Previously
3449 it did the reset first. */
3450
3451 case HELO_CMD:
b4ed4da0 3452 HAD(SCH_HELO);
059ec3d9
PH
3453 hello = US"HELO";
3454 esmtp = FALSE;
3455 goto HELO_EHLO;
3456
3457 case EHLO_CMD:
b4ed4da0 3458 HAD(SCH_EHLO);
059ec3d9
PH
3459 hello = US"EHLO";
3460 esmtp = TRUE;
3461
3462 HELO_EHLO: /* Common code for HELO and EHLO */
3463 cmd_list[CMD_LIST_HELO].is_mail_cmd = FALSE;
3464 cmd_list[CMD_LIST_EHLO].is_mail_cmd = FALSE;
3465
3466 /* Reject the HELO if its argument was invalid or non-existent. A
3467 successful check causes the argument to be saved in malloc store. */
3468
ca86f471 3469 if (!check_helo(smtp_cmd_data))
059ec3d9
PH
3470 {
3471 smtp_printf("501 Syntactically invalid %s argument(s)\r\n", hello);
3472
3473 log_write(0, LOG_MAIN|LOG_REJECT, "rejected %s from %s: syntactically "
3474 "invalid argument(s): %s", hello, host_and_ident(FALSE),
3ee512ff
PH
3475 (*smtp_cmd_argument == 0)? US"(no argument given)" :
3476 string_printing(smtp_cmd_argument));
059ec3d9
PH
3477
3478 if (++synprot_error_count > smtp_max_synprot_errors)
3479 {
3480 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
3481 "syntax or protocol errors (last command was \"%s\")",
0ebc4d69 3482 host_and_ident(FALSE), string_printing(smtp_cmd_buffer));
059ec3d9
PH
3483 done = 1;
3484 }
3485
3486 break;
3487 }
3488
3489 /* If sender_host_unknown is true, we have got here via the -bs interface,
3490 not called from inetd. Otherwise, we are running an IP connection and the
3491 host address will be set. If the helo name is the primary name of this
3492 host and we haven't done a reverse lookup, force one now. If helo_required
3493 is set, ensure that the HELO name matches the actual host. If helo_verify
3494 is set, do the same check, but softly. */
3495
3496 if (!sender_host_unknown)
3497 {
3498 BOOL old_helo_verified = helo_verified;
ca86f471 3499 uschar *p = smtp_cmd_data;
059ec3d9
PH
3500
3501 while (*p != 0 && !isspace(*p)) { *p = tolower(*p); p++; }
3502 *p = 0;
3503
3504 /* Force a reverse lookup if HELO quoted something in helo_lookup_domains
3505 because otherwise the log can be confusing. */
3506
3507 if (sender_host_name == NULL &&
3508 (deliver_domain = sender_helo_name, /* set $domain */
55414b25 3509 match_isinlist(sender_helo_name, CUSS &helo_lookup_domains, 0,
059ec3d9
PH
3510 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL)) == OK)
3511 (void)host_name_lookup();
3512
3513 /* Rebuild the fullhost info to include the HELO name (and the real name
3514 if it was looked up.) */
3515
3516 host_build_sender_fullhost(); /* Rebuild */
3517 set_process_info("handling%s incoming connection from %s",
817d9f57 3518 (tls_in.active >= 0)? " TLS" : "", host_and_ident(FALSE));
059ec3d9
PH
3519
3520 /* Verify if configured. This doesn't give much security, but it does
d7b47fd0
PH
3521 make some people happy to be able to do it. If helo_required is set,
3522 (host matches helo_verify_hosts) failure forces rejection. If helo_verify
3523 is set (host matches helo_try_verify_hosts), it does not. This is perhaps
3524 now obsolescent, since the verification can now be requested selectively
3525 at ACL time. */
059ec3d9 3526
1705dd20 3527 helo_verified = helo_verify_failed = sender_helo_dnssec = FALSE;
059ec3d9
PH
3528 if (helo_required || helo_verify)
3529 {
d7b47fd0 3530 BOOL tempfail = !smtp_verify_helo();
059ec3d9
PH
3531 if (!helo_verified)
3532 {
3533 if (helo_required)
3534 {
3535 smtp_printf("%d %s argument does not match calling host\r\n",
3536 tempfail? 451 : 550, hello);
3537 log_write(0, LOG_MAIN|LOG_REJECT, "%srejected \"%s %s\" from %s",
3538 tempfail? "temporarily " : "",
3539 hello, sender_helo_name, host_and_ident(FALSE));
3540 helo_verified = old_helo_verified;
3541 break; /* End of HELO/EHLO processing */
3542 }
3543 HDEBUG(D_all) debug_printf("%s verification failed but host is in "
3544 "helo_try_verify_hosts\n", hello);
3545 }
3546 }
3547 }
3548
8523533c
TK
3549#ifdef EXPERIMENTAL_SPF
3550 /* set up SPF context */
3551 spf_init(sender_helo_name, sender_host_address);
3552#endif
3553
a14e5636
PH
3554 /* Apply an ACL check if one is defined; afterwards, recheck
3555 synchronization in case the client started sending in a delay. */
059ec3d9
PH
3556
3557 if (acl_smtp_helo != NULL)
3558 {
64ffc24f 3559 rc = acl_check(ACL_WHERE_HELO, NULL, acl_smtp_helo, &user_msg, &log_msg);
059ec3d9
PH
3560 if (rc != OK)
3561 {
3562 done = smtp_handle_acl_fail(ACL_WHERE_HELO, rc, user_msg, log_msg);
3563 sender_helo_name = NULL;
3564 host_build_sender_fullhost(); /* Rebuild */
3565 break;
3566 }
a14e5636 3567 else if (!check_sync()) goto SYNC_FAILURE;
059ec3d9
PH
3568 }
3569
4e88a19f
PH
3570 /* Generate an OK reply. The default string includes the ident if present,
3571 and also the IP address if present. Reflecting back the ident is intended
3572 as a deterrent to mail forgers. For maximum efficiency, and also because
3573 some broken systems expect each response to be in a single packet, arrange
3574 that the entire reply is sent in one write(). */
059ec3d9
PH
3575
3576 auth_advertised = FALSE;
3577 pipelining_advertised = FALSE;
d1a13eea 3578#ifdef SUPPORT_TLS
059ec3d9 3579 tls_advertised = FALSE;
d1a13eea 3580#endif
6c1c3d1d 3581 dsn_advertised = FALSE;
d1a13eea
JH
3582#ifdef EXPERIMENTAL_INTERNATIONAL
3583 smtputf8_advertised = FALSE;
3584#endif
059ec3d9 3585
d6a96edc 3586 smtp_code = US"250 "; /* Default response code plus space*/
4e88a19f
PH
3587 if (user_msg == NULL)
3588 {
3589 s = string_sprintf("%.3s %s Hello %s%s%s",
3590 smtp_code,
3591 smtp_active_hostname,
3592 (sender_ident == NULL)? US"" : sender_ident,
3593 (sender_ident == NULL)? US"" : US" at ",
3594 (sender_host_name == NULL)? sender_helo_name : sender_host_name);
3595
3596 ptr = Ustrlen(s);
3597 size = ptr + 1;
059ec3d9 3598
4e88a19f
PH
3599 if (sender_host_address != NULL)
3600 {
3601 s = string_cat(s, &size, &ptr, US" [", 2);
3602 s = string_cat(s, &size, &ptr, sender_host_address,
3603 Ustrlen(sender_host_address));
3604 s = string_cat(s, &size, &ptr, US"]", 1);
3605 }
3606 }
3607
d6a96edc
PH
3608 /* A user-supplied EHLO greeting may not contain more than one line. Note
3609 that the code returned by smtp_message_code() includes the terminating
3610 whitespace character. */
059ec3d9 3611
4e88a19f 3612 else
059ec3d9 3613 {
4e88a19f 3614 char *ss;
d6a96edc 3615 int codelen = 4;
4e88a19f 3616 smtp_message_code(&smtp_code, &codelen, &user_msg, NULL);
d6a96edc 3617 s = string_sprintf("%.*s%s", codelen, smtp_code, user_msg);
4e88a19f
PH
3618 if ((ss = strpbrk(CS s, "\r\n")) != NULL)
3619 {
3620 log_write(0, LOG_MAIN|LOG_PANIC, "EHLO/HELO response must not contain "
3621 "newlines: message truncated: %s", string_printing(s));
3622 *ss = 0;
3623 }
3624 ptr = Ustrlen(s);
3625 size = ptr + 1;
059ec3d9
PH
3626 }
3627
3628 s = string_cat(s, &size, &ptr, US"\r\n", 2);
3629
3630 /* If we received EHLO, we must create a multiline response which includes
3631 the functions supported. */
3632
3633 if (esmtp)
3634 {
3635 s[3] = '-';
3636
3637 /* I'm not entirely happy with this, as an MTA is supposed to check
3638 that it has enough room to accept a message of maximum size before
3639 it sends this. However, there seems little point in not sending it.
3640 The actual size check happens later at MAIL FROM time. By postponing it
3641 till then, VRFY and EXPN can be used after EHLO when space is short. */
3642
3643 if (thismessage_size_limit > 0)
3644 {
4e88a19f
PH
3645 sprintf(CS big_buffer, "%.3s-SIZE %d\r\n", smtp_code,
3646 thismessage_size_limit);
059ec3d9
PH
3647 s = string_cat(s, &size, &ptr, big_buffer, Ustrlen(big_buffer));
3648 }
3649 else
3650 {
4e88a19f
PH
3651 s = string_cat(s, &size, &ptr, smtp_code, 3);
3652 s = string_cat(s, &size, &ptr, US"-SIZE\r\n", 7);
059ec3d9
PH
3653 }
3654
3655 /* Exim does not do protocol conversion or data conversion. It is 8-bit
3656 clean; if it has an 8-bit character in its hand, it just sends it. It
3657 cannot therefore specify 8BITMIME and remain consistent with the RFCs.
3658 However, some users want this option simply in order to stop MUAs
3659 mangling messages that contain top-bit-set characters. It is therefore
3660 provided as an option. */
3661
3662 if (accept_8bitmime)
4e88a19f
PH
3663 {
3664 s = string_cat(s, &size, &ptr, smtp_code, 3);
3665 s = string_cat(s, &size, &ptr, US"-8BITMIME\r\n", 11);
3666 }
059ec3d9 3667
6c1c3d1d
WB
3668 /* Advertise DSN support if configured to do so. */
3669 if (verify_check_host(&dsn_advertise_hosts) != FAIL)
3670 {
3671 s = string_cat(s, &size, &ptr, smtp_code, 3);
3672 s = string_cat(s, &size, &ptr, US"-DSN\r\n", 6);
3673 dsn_advertised = TRUE;
3674 }
6c1c3d1d 3675
059ec3d9
PH
3676 /* Advertise ETRN if there's an ACL checking whether a host is
3677 permitted to issue it; a check is made when any host actually tries. */
3678
3679 if (acl_smtp_etrn != NULL)
3680 {
4e88a19f
PH
3681 s = string_cat(s, &size, &ptr, smtp_code, 3);
3682 s = string_cat(s, &size, &ptr, US"-ETRN\r\n", 7);
059ec3d9
PH
3683 }
3684
3685 /* Advertise EXPN if there's an ACL checking whether a host is
3686 permitted to issue it; a check is made when any host actually tries. */
3687
3688 if (acl_smtp_expn != NULL)
3689 {
4e88a19f
PH
3690 s = string_cat(s, &size, &ptr, smtp_code, 3);
3691 s = string_cat(s, &size, &ptr, US"-EXPN\r\n", 7);
059ec3d9
PH
3692 }
3693
3694 /* Exim is quite happy with pipelining, so let the other end know that
3695 it is safe to use it, unless advertising is disabled. */
3696
cf8b11a5
PH
3697 if (pipelining_enable &&
3698 verify_check_host(&pipelining_advertise_hosts) == OK)
059ec3d9 3699 {
4e88a19f
PH
3700 s = string_cat(s, &size, &ptr, smtp_code, 3);
3701 s = string_cat(s, &size, &ptr, US"-PIPELINING\r\n", 13);
059ec3d9
PH
3702 sync_cmd_limit = NON_SYNC_CMD_PIPELINING;
3703 pipelining_advertised = TRUE;
3704 }
3705
fd98a5c6 3706
059ec3d9
PH
3707 /* If any server authentication mechanisms are configured, advertise
3708 them if the current host is in auth_advertise_hosts. The problem with
3709 advertising always is that some clients then require users to
3710 authenticate (and aren't configurable otherwise) even though it may not
3711 be necessary (e.g. if the host is in host_accept_relay).
3712
3713 RFC 2222 states that SASL mechanism names contain only upper case
3714 letters, so output the names in upper case, though we actually recognize
3715 them in either case in the AUTH command. */
3716
b3ef41c9
JH
3717 if ( auths
3718#if defined(SUPPORT_TLS) && defined(AUTH_TLS)
3719 && !sender_host_authenticated
3720#endif
3721 && verify_check_host(&auth_advertise_hosts) == OK
3722 )
3723 {
3724 auth_instance *au;
3725 BOOL first = TRUE;
3726 for (au = auths; au; au = au->next)
3727 if (au->server && (au->advertise_condition == NULL ||
3728 expand_check_condition(au->advertise_condition, au->name,
3729 US"authenticator")))
3730 {
3731 int saveptr;
3732 if (first)
3733 {
3734 s = string_cat(s, &size, &ptr, smtp_code, 3);
3735 s = string_cat(s, &size, &ptr, US"-AUTH", 5);
3736 first = FALSE;
3737 auth_advertised = TRUE;
3738 }
3739 saveptr = ptr;
3740 s = string_cat(s, &size, &ptr, US" ", 1);
3741 s = string_cat(s, &size, &ptr, au->public_name,
3742 Ustrlen(au->public_name));
3743 while (++saveptr < ptr) s[saveptr] = toupper(s[saveptr]);
3744 au->advertised = TRUE;
3745 }
3746 else
3747 au->advertised = FALSE;
3748
3749 if (!first) s = string_cat(s, &size, &ptr, US"\r\n", 2);
3750 }
059ec3d9
PH
3751
3752 /* Advertise TLS (Transport Level Security) aka SSL (Secure Socket Layer)
3753 if it has been included in the binary, and the host matches
3754 tls_advertise_hosts. We must *not* advertise if we are already in a
3755 secure connection. */
3756
d1a13eea 3757#ifdef SUPPORT_TLS
817d9f57 3758 if (tls_in.active < 0 &&
059ec3d9
PH
3759 verify_check_host(&tls_advertise_hosts) != FAIL)
3760 {
4e88a19f
PH
3761 s = string_cat(s, &size, &ptr, smtp_code, 3);
3762 s = string_cat(s, &size, &ptr, US"-STARTTLS\r\n", 11);
059ec3d9
PH
3763 tls_advertised = TRUE;
3764 }
d1a13eea 3765#endif
059ec3d9 3766
d1a13eea 3767#ifndef DISABLE_PRDR
fd98a5c6 3768 /* Per Recipient Data Response, draft by Eric A. Hall extending RFC */
8ccd00b1
JH
3769 if (prdr_enable)
3770 {
fd98a5c6
JH
3771 s = string_cat(s, &size, &ptr, smtp_code, 3);
3772 s = string_cat(s, &size, &ptr, US"-PRDR\r\n", 7);
8ccd00b1 3773 }
d1a13eea
JH
3774#endif
3775
3776#ifdef EXPERIMENTAL_INTERNATIONAL
3777 if ( accept_8bitmime
3778 && verify_check_host(&smtputf8_advertise_hosts) != FAIL)
3779 {
3780 s = string_cat(s, &size, &ptr, smtp_code, 3);
3781 s = string_cat(s, &size, &ptr, US"-SMTPUTF8\r\n", 11);
3782 smtputf8_advertised = TRUE;
3783 }
3784#endif
fd98a5c6 3785
059ec3d9
PH
3786 /* Finish off the multiline reply with one that is always available. */
3787
4e88a19f
PH
3788 s = string_cat(s, &size, &ptr, smtp_code, 3);
3789 s = string_cat(s, &size, &ptr, US" HELP\r\n", 7);
059ec3d9
PH
3790 }