TLS: downgrade fail of cert-based authentication from log message to debug messsage
[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"
2ef7ed08 12#include <assert.h>
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13
14
15/* Initialize for TCP wrappers if so configured. It appears that the macro
16HAVE_IPV6 is used in some versions of the tcpd.h header, so we unset it before
17including that header, and restore its value afterwards. */
18
19#ifdef USE_TCP_WRAPPERS
20
21 #if HAVE_IPV6
22 #define EXIM_HAVE_IPV6
23 #endif
24 #undef HAVE_IPV6
25 #include <tcpd.h>
26 #undef HAVE_IPV6
27 #ifdef EXIM_HAVE_IPV6
28 #define HAVE_IPV6 TRUE
29 #endif
30
31int allow_severity = LOG_INFO;
32int deny_severity = LOG_NOTICE;
5dc43717 33uschar *tcp_wrappers_name;
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34#endif
35
36
8d67ada3
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37/* Size of buffer for reading SMTP commands. We used to use 512, as defined
38by RFC 821. However, RFC 1869 specifies that this must be increased for SMTP
39commands that accept arguments, and this in particular applies to AUTH, where
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40the data can be quite long. More recently this value was 2048 in Exim;
41however, RFC 4954 (circa 2007) recommends 12288 bytes to handle AUTH. Clients
42such as Thunderbird will send an AUTH with an initial-response for GSSAPI.
43The maximum size of a Kerberos ticket under Windows 2003 is 12000 bytes, and
44we need room to handle large base64-encoded AUTHs for GSSAPI.
45*/
46
47#define smtp_cmd_buffer_size 16384
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48
49/* Size of buffer for reading SMTP incoming packets */
50
51#define in_buffer_size 8192
52
53/* Structure for SMTP command list */
54
55typedef struct {
1ba28e2b 56 const char *name;
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57 int len;
58 short int cmd;
59 short int has_arg;
60 short int is_mail_cmd;
61} smtp_cmd_list;
62
63/* Codes for identifying commands. We order them so that those that come first
64are those for which synchronization is always required. Checking this can help
65block some spam. */
66
67enum {
68 /* These commands are required to be synchronized, i.e. to be the last in a
69 block of commands when pipelining. */
70
71 HELO_CMD, EHLO_CMD, DATA_CMD, /* These are listed in the pipelining */
72 VRFY_CMD, EXPN_CMD, NOOP_CMD, /* RFC as requiring synchronization */
73 ETRN_CMD, /* This by analogy with TURN from the RFC */
74 STARTTLS_CMD, /* Required by the STARTTLS RFC */
b3ef41c9 75 TLS_AUTH_CMD, /* auto-command at start of SSL */
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76
77 /* This is a dummy to identify the non-sync commands when pipelining */
78
79 NON_SYNC_CMD_PIPELINING,
80
81 /* These commands need not be synchronized when pipelining */
82
83 MAIL_CMD, RCPT_CMD, RSET_CMD,
84
85 /* This is a dummy to identify the non-sync commands when not pipelining */
86
87 NON_SYNC_CMD_NON_PIPELINING,
88
89 /* I have been unable to find a statement about the use of pipelining
90 with AUTH, so to be on the safe side it is here, though I kind of feel
91 it should be up there with the synchronized commands. */
92
93 AUTH_CMD,
94
95 /* I'm not sure about these, but I don't think they matter. */
96
97 QUIT_CMD, HELP_CMD,
98
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99#ifdef EXPERIMENTAL_PROXY
100 PROXY_FAIL_IGNORE_CMD,
101#endif
102
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103 /* These are specials that don't correspond to actual commands */
104
105 EOF_CMD, OTHER_CMD, BADARG_CMD, BADCHAR_CMD, BADSYN_CMD,
106 TOO_MANY_NONMAIL_CMD };
107
108
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109/* This is a convenience macro for adding the identity of an SMTP command
110to the circular buffer that holds a list of the last n received. */
111
112#define HAD(n) \
113 smtp_connection_had[smtp_ch_index++] = n; \
114 if (smtp_ch_index >= SMTP_HBUFF_SIZE) smtp_ch_index = 0
115
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116
117/*************************************************
118* Local static variables *
119*************************************************/
120
121static auth_instance *authenticated_by;
122static BOOL auth_advertised;
123#ifdef SUPPORT_TLS
124static BOOL tls_advertised;
125#endif
6c1c3d1d 126static BOOL dsn_advertised;
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127static BOOL esmtp;
128static BOOL helo_required = FALSE;
129static BOOL helo_verify = FALSE;
130static BOOL helo_seen;
131static BOOL helo_accept_junk;
132static BOOL count_nonmail;
133static BOOL pipelining_advertised;
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134static BOOL rcpt_smtp_response_same;
135static BOOL rcpt_in_progress;
059ec3d9 136static int nonmail_command_count;
8f128379 137static BOOL smtp_exit_function_called = 0;
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138#ifdef EXPERIMENTAL_INTERNATIONAL
139static BOOL smtputf8_advertised;
140#endif
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141static int synprot_error_count;
142static int unknown_command_count;
143static int sync_cmd_limit;
144static int smtp_write_error = 0;
145
2679d413 146static uschar *rcpt_smtp_response;
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147static uschar *smtp_data_buffer;
148static uschar *smtp_cmd_data;
149
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150/* We need to know the position of RSET, HELO, EHLO, AUTH, and STARTTLS. Their
151final fields of all except AUTH are forced TRUE at the start of a new message
152setup, to allow one of each between messages that is not counted as a nonmail
153command. (In fact, only one of HELO/EHLO is not counted.) Also, we have to
154allow a new EHLO after starting up TLS.
155
156AUTH is "falsely" labelled as a mail command initially, so that it doesn't get
157counted. However, the flag is changed when AUTH is received, so that multiple
158failing AUTHs will eventually hit the limit. After a successful AUTH, another
159AUTH is already forbidden. After a TLS session is started, AUTH's flag is again
160forced TRUE, to allow for the re-authentication that can happen at that point.
161
162QUIT is also "falsely" labelled as a mail command so that it doesn't up the
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163count of non-mail commands and possibly provoke an error.
164
165tls_auth is a pseudo-command, never expected in input. It is activated
166on TLS startup and looks for a tls authenticator. */
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167
168static smtp_cmd_list cmd_list[] = {
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169 /* name len cmd has_arg is_mail_cmd */
170
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171 { "rset", sizeof("rset")-1, RSET_CMD, FALSE, FALSE }, /* First */
172 { "helo", sizeof("helo")-1, HELO_CMD, TRUE, FALSE },
173 { "ehlo", sizeof("ehlo")-1, EHLO_CMD, TRUE, FALSE },
174 { "auth", sizeof("auth")-1, AUTH_CMD, TRUE, TRUE },
175 #ifdef SUPPORT_TLS
176 { "starttls", sizeof("starttls")-1, STARTTLS_CMD, FALSE, FALSE },
b3ef41c9 177 { "tls_auth", 0, TLS_AUTH_CMD, FALSE, TRUE },
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178 #endif
179
180/* If you change anything above here, also fix the definitions below. */
181
182 { "mail from:", sizeof("mail from:")-1, MAIL_CMD, TRUE, TRUE },
183 { "rcpt to:", sizeof("rcpt to:")-1, RCPT_CMD, TRUE, TRUE },
184 { "data", sizeof("data")-1, DATA_CMD, FALSE, TRUE },
185 { "quit", sizeof("quit")-1, QUIT_CMD, FALSE, TRUE },
186 { "noop", sizeof("noop")-1, NOOP_CMD, TRUE, FALSE },
187 { "etrn", sizeof("etrn")-1, ETRN_CMD, TRUE, FALSE },
188 { "vrfy", sizeof("vrfy")-1, VRFY_CMD, TRUE, FALSE },
189 { "expn", sizeof("expn")-1, EXPN_CMD, TRUE, FALSE },
190 { "help", sizeof("help")-1, HELP_CMD, TRUE, FALSE }
191};
192
193static smtp_cmd_list *cmd_list_end =
194 cmd_list + sizeof(cmd_list)/sizeof(smtp_cmd_list);
195
196#define CMD_LIST_RSET 0
197#define CMD_LIST_HELO 1
198#define CMD_LIST_EHLO 2
199#define CMD_LIST_AUTH 3
200#define CMD_LIST_STARTTLS 4
b3ef41c9 201#define CMD_LIST_TLS_AUTH 5
059ec3d9 202
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203/* This list of names is used for performing the smtp_no_mail logging action.
204It must be kept in step with the SCH_xxx enumerations. */
205
206static uschar *smtp_names[] =
207 {
208 US"NONE", US"AUTH", US"DATA", US"EHLO", US"ETRN", US"EXPN", US"HELO",
209 US"HELP", US"MAIL", US"NOOP", US"QUIT", US"RCPT", US"RSET", US"STARTTLS",
210 US"VRFY" };
211
e524074d 212static uschar *protocols_local[] = {
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213 US"local-smtp", /* HELO */
214 US"local-smtps", /* The rare case EHLO->STARTTLS->HELO */
215 US"local-esmtp", /* EHLO */
216 US"local-esmtps", /* EHLO->STARTTLS->EHLO */
217 US"local-esmtpa", /* EHLO->AUTH */
218 US"local-esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */
059ec3d9 219 };
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220static uschar *protocols[] = {
221 US"smtp", /* HELO */
222 US"smtps", /* The rare case EHLO->STARTTLS->HELO */
223 US"esmtp", /* EHLO */
224 US"esmtps", /* EHLO->STARTTLS->EHLO */
225 US"esmtpa", /* EHLO->AUTH */
226 US"esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */
227 };
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228
229#define pnormal 0
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230#define pextend 2
231#define pcrpted 1 /* added to pextend or pnormal */
232#define pauthed 2 /* added to pextend */
059ec3d9 233
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234/* Sanity check and validate optional args to MAIL FROM: envelope */
235enum {
2ef7ed08 236 ENV_MAIL_OPT_NULL,
d27f98fe 237 ENV_MAIL_OPT_SIZE, ENV_MAIL_OPT_BODY, ENV_MAIL_OPT_AUTH,
8ccd00b1 238#ifndef DISABLE_PRDR
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239 ENV_MAIL_OPT_PRDR,
240#endif
6c1c3d1d 241 ENV_MAIL_OPT_RET, ENV_MAIL_OPT_ENVID,
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242#ifdef EXPERIMENTAL_INTERNATIONAL
243 ENV_MAIL_OPT_UTF8,
244#endif
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245 };
246typedef struct {
247 uschar * name; /* option requested during MAIL cmd */
248 int value; /* enum type */
249 BOOL need_value; /* TRUE requires value (name=value pair format)
250 FALSE is a singleton */
251 } env_mail_type_t;
252static env_mail_type_t env_mail_type_list[] = {
253 { US"SIZE", ENV_MAIL_OPT_SIZE, TRUE },
254 { US"BODY", ENV_MAIL_OPT_BODY, TRUE },
255 { US"AUTH", ENV_MAIL_OPT_AUTH, TRUE },
8ccd00b1 256#ifndef DISABLE_PRDR
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257 { US"PRDR", ENV_MAIL_OPT_PRDR, FALSE },
258#endif
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259 { US"RET", ENV_MAIL_OPT_RET, TRUE },
260 { US"ENVID", ENV_MAIL_OPT_ENVID, TRUE },
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261#ifdef EXPERIMENTAL_INTERNATIONAL
262 { US"SMTPUTF8",ENV_MAIL_OPT_UTF8, FALSE }, /* rfc6531 */
263#endif
2ef7ed08
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264 /* keep this the last entry */
265 { US"NULL", ENV_MAIL_OPT_NULL, FALSE },
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266 };
267
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268/* When reading SMTP from a remote host, we have to use our own versions of the
269C input-reading functions, in order to be able to flush the SMTP output only
270when about to read more data from the socket. This is the only way to get
271optimal performance when the client is using pipelining. Flushing for every
272command causes a separate packet and reply packet each time; saving all the
273responses up (when pipelining) combines them into one packet and one response.
274
275For simplicity, these functions are used for *all* SMTP input, not only when
276receiving over a socket. However, after setting up a secure socket (SSL), input
277is read via the OpenSSL library, and another set of functions is used instead
278(see tls.c).
279
280These functions are set in the receive_getc etc. variables and called with the
281same interface as the C functions. However, since there can only ever be
282one incoming SMTP call, we just use a single buffer and flags. There is no need
283to implement a complicated private FILE-like structure.*/
284
285static uschar *smtp_inbuffer;
286static uschar *smtp_inptr;
287static uschar *smtp_inend;
288static int smtp_had_eof;
289static int smtp_had_error;
290
291
292/*************************************************
293* SMTP version of getc() *
294*************************************************/
295
296/* This gets the next byte from the SMTP input buffer. If the buffer is empty,
297it flushes the output, and refills the buffer, with a timeout. The signal
298handler is set appropriately by the calling function. This function is not used
299after a connection has negotated itself into an TLS/SSL state.
300
301Arguments: none
302Returns: the next character or EOF
303*/
304
305int
306smtp_getc(void)
307{
308if (smtp_inptr >= smtp_inend)
309 {
310 int rc, save_errno;
311 fflush(smtp_out);
312 if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
313 rc = read(fileno(smtp_in), smtp_inbuffer, in_buffer_size);
314 save_errno = errno;
315 alarm(0);
316 if (rc <= 0)
317 {
318 /* Must put the error text in fixed store, because this might be during
319 header reading, where it releases unused store above the header. */
320 if (rc < 0)
321 {
322 smtp_had_error = save_errno;
323 smtp_read_error = string_copy_malloc(
324 string_sprintf(" (error: %s)", strerror(save_errno)));
325 }
326 else smtp_had_eof = 1;
327 return EOF;
328 }
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329#ifndef DISABLE_DKIM
330 dkim_exim_verify_feed(smtp_inbuffer, rc);
331#endif
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332 smtp_inend = smtp_inbuffer + rc;
333 smtp_inptr = smtp_inbuffer;
334 }
335return *smtp_inptr++;
336}
337
338
339
340/*************************************************
341* SMTP version of ungetc() *
342*************************************************/
343
344/* Puts a character back in the input buffer. Only ever
345called once.
346
347Arguments:
348 ch the character
349
350Returns: the character
351*/
352
353int
354smtp_ungetc(int ch)
355{
356*(--smtp_inptr) = ch;
357return ch;
358}
359
360
361
362
363/*************************************************
364* SMTP version of feof() *
365*************************************************/
366
367/* Tests for a previous EOF
368
369Arguments: none
370Returns: non-zero if the eof flag is set
371*/
372
373int
374smtp_feof(void)
375{
376return smtp_had_eof;
377}
378
379
380
381
382/*************************************************
383* SMTP version of ferror() *
384*************************************************/
385
386/* Tests for a previous read error, and returns with errno
387restored to what it was when the error was detected.
388
389Arguments: none
390Returns: non-zero if the error flag is set
391*/
392
393int
394smtp_ferror(void)
395{
396errno = smtp_had_error;
397return smtp_had_error;
398}
399
400
401
58eb016e
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402/*************************************************
403* Test for characters in the SMTP buffer *
404*************************************************/
405
406/* Used at the end of a message
407
408Arguments: none
409Returns: TRUE/FALSE
410*/
411
412BOOL
413smtp_buffered(void)
414{
415return smtp_inptr < smtp_inend;
416}
417
418
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419
420/*************************************************
421* Write formatted string to SMTP channel *
422*************************************************/
423
424/* This is a separate function so that we don't have to repeat everything for
425TLS support or debugging. It is global so that the daemon and the
426authentication functions can use it. It does not return any error indication,
427because major problems such as dropped connections won't show up till an output
428flush for non-TLS connections. The smtp_fflush() function is available for
429checking that: for convenience, TLS output errors are remembered here so that
430they are also picked up later by smtp_fflush().
431
432Arguments:
433 format format string
434 ... optional arguments
435
436Returns: nothing
437*/
438
439void
1ba28e2b 440smtp_printf(const char *format, ...)
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441{
442va_list ap;
443
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444va_start(ap, format);
445smtp_vprintf(format, ap);
446va_end(ap);
447}
448
449/* This is split off so that verify.c:respond_printf() can, in effect, call
450smtp_printf(), bearing in mind that in C a vararg function can't directly
fb08281f 451call another vararg function, only a function which accepts a va_list. */
ce552449
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452
453void
1ba28e2b 454smtp_vprintf(const char *format, va_list ap)
ce552449 455{
fb08281f
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456BOOL yield;
457
458yield = string_vformat(big_buffer, big_buffer_size, format, ap);
ce552449 459
059ec3d9
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460DEBUG(D_receive)
461 {
fb08281f
DW
462 void *reset_point = store_get(0);
463 uschar *msg_copy, *cr, *end;
464 msg_copy = string_copy(big_buffer);
465 end = msg_copy + Ustrlen(msg_copy);
466 while ((cr = Ustrchr(msg_copy, '\r')) != NULL) /* lose CRs */
467 memmove(cr, cr + 1, (end--) - cr);
468 debug_printf("SMTP>> %s", msg_copy);
469 store_reset(reset_point);
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470 }
471
fb08281f 472if (!yield)
2679d413
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473 {
474 log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_printf()");
475 smtp_closedown(US"Unexpected error");
476 exim_exit(EXIT_FAILURE);
477 }
2679d413
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478
479/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
480have had the same. Note: this code is also present in smtp_respond(). It would
481be tidier to have it only in one place, but when it was added, it was easier to
482do it that way, so as not to have to mess with the code for the RCPT command,
483which sometimes uses smtp_printf() and sometimes smtp_respond(). */
484
485if (rcpt_in_progress)
486 {
487 if (rcpt_smtp_response == NULL)
488 rcpt_smtp_response = string_copy(big_buffer);
489 else if (rcpt_smtp_response_same &&
490 Ustrcmp(rcpt_smtp_response, big_buffer) != 0)
491 rcpt_smtp_response_same = FALSE;
492 rcpt_in_progress = FALSE;
493 }
059ec3d9 494
2679d413 495/* Now write the string */
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496
497#ifdef SUPPORT_TLS
817d9f57 498if (tls_in.active >= 0)
059ec3d9 499 {
817d9f57
JH
500 if (tls_write(TRUE, big_buffer, Ustrlen(big_buffer)) < 0)
501 smtp_write_error = -1;
059ec3d9
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502 }
503else
504#endif
505
2679d413 506if (fprintf(smtp_out, "%s", big_buffer) < 0) smtp_write_error = -1;
059ec3d9
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507}
508
509
510
511/*************************************************
512* Flush SMTP out and check for error *
513*************************************************/
514
515/* This function isn't currently used within Exim (it detects errors when it
516tries to read the next SMTP input), but is available for use in local_scan().
517For non-TLS connections, it flushes the output and checks for errors. For
518TLS-connections, it checks for a previously-detected TLS write error.
519
520Arguments: none
521Returns: 0 for no error; -1 after an error
522*/
523
524int
525smtp_fflush(void)
526{
817d9f57 527if (tls_in.active < 0 && fflush(smtp_out) != 0) smtp_write_error = -1;
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528return smtp_write_error;
529}
530
531
532
533/*************************************************
534* SMTP command read timeout *
535*************************************************/
536
537/* Signal handler for timing out incoming SMTP commands. This attempts to
538finish off tidily.
539
540Argument: signal number (SIGALRM)
541Returns: nothing
542*/
543
544static void
545command_timeout_handler(int sig)
546{
547sig = sig; /* Keep picky compilers happy */
548log_write(L_lost_incoming_connection,
549 LOG_MAIN, "SMTP command timeout on%s connection from %s",
817d9f57 550 (tls_in.active >= 0)? " TLS" : "",
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551 host_and_ident(FALSE));
552if (smtp_batched_input)
553 moan_smtp_batch(NULL, "421 SMTP command timeout"); /* Does not return */
8f128379
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554smtp_notquit_exit(US"command-timeout", US"421",
555 US"%s: SMTP command timeout - closing connection", smtp_active_hostname);
059ec3d9
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556exim_exit(EXIT_FAILURE);
557}
558
559
560
561/*************************************************
562* SIGTERM received *
563*************************************************/
564
565/* Signal handler for handling SIGTERM. Again, try to finish tidily.
566
567Argument: signal number (SIGTERM)
568Returns: nothing
569*/
570
571static void
572command_sigterm_handler(int sig)
573{
574sig = sig; /* Keep picky compilers happy */
575log_write(0, LOG_MAIN, "%s closed after SIGTERM", smtp_get_connection_info());
576if (smtp_batched_input)
577 moan_smtp_batch(NULL, "421 SIGTERM received"); /* Does not return */
8f128379
PH
578smtp_notquit_exit(US"signal-exit", US"421",
579 US"%s: Service not available - closing connection", smtp_active_hostname);
059ec3d9
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580exim_exit(EXIT_FAILURE);
581}
582
583
584
a14e5636 585
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586#ifdef EXPERIMENTAL_PROXY
587/*************************************************
a3bddaa8
TL
588* Restore socket timeout to previous value *
589*************************************************/
590/* If the previous value was successfully retrieved, restore
591it before returning control to the non-proxy routines
592
593Arguments: fd - File descriptor for input
594 get_ok - Successfully retrieved previous values
595 tvtmp - Time struct with previous values
596 vslen - Length of time struct
597Returns: none
598*/
599static void
600restore_socket_timeout(int fd, int get_ok, struct timeval tvtmp, socklen_t vslen)
601{
602if (get_ok == 0)
603 setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, (char *)&tvtmp, vslen);
604}
605
606/*************************************************
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607* Check if host is required proxy host *
608*************************************************/
609/* The function determines if inbound host will be a regular smtp host
610or if it is configured that it must use Proxy Protocol.
611
612Arguments: none
613Returns: bool
614*/
615
616static BOOL
617check_proxy_protocol_host()
618{
619int rc;
620/* Cannot configure local connection as a proxy inbound */
621if (sender_host_address == NULL) return proxy_session;
622
623rc = verify_check_this_host(&proxy_required_hosts, NULL, NULL,
624 sender_host_address, NULL);
625if (rc == OK)
626 {
627 DEBUG(D_receive)
628 debug_printf("Detected proxy protocol configured host\n");
629 proxy_session = TRUE;
630 }
631return proxy_session;
632}
633
634
635/*************************************************
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636* Setup host for proxy protocol *
637*************************************************/
638/* The function configures the connection based on a header from the
639inbound host to use Proxy Protocol. The specification is very exact
640so exit with an error if do not find the exact required pieces. This
641includes an incorrect number of spaces separating args.
642
643Arguments: none
644Returns: int
645*/
646
647static BOOL
648setup_proxy_protocol_host()
649{
650union {
651 struct {
652 uschar line[108];
653 } v1;
654 struct {
655 uschar sig[12];
36719342
TL
656 uint8_t ver_cmd;
657 uint8_t fam;
658 uint16_t len;
a3c86431
TL
659 union {
660 struct { /* TCP/UDP over IPv4, len = 12 */
661 uint32_t src_addr;
662 uint32_t dst_addr;
663 uint16_t src_port;
664 uint16_t dst_port;
665 } ip4;
666 struct { /* TCP/UDP over IPv6, len = 36 */
667 uint8_t src_addr[16];
668 uint8_t dst_addr[16];
669 uint16_t src_port;
670 uint16_t dst_port;
671 } ip6;
672 struct { /* AF_UNIX sockets, len = 216 */
673 uschar src_addr[108];
674 uschar dst_addr[108];
675 } unx;
676 } addr;
677 } v2;
678} hdr;
679
eb57651e
TL
680/* Temp variables used in PPv2 address:port parsing */
681uint16_t tmpport;
682char tmpip[INET_ADDRSTRLEN];
683struct sockaddr_in tmpaddr;
684char tmpip6[INET6_ADDRSTRLEN];
685struct sockaddr_in6 tmpaddr6;
686
687int get_ok = 0;
a3c86431 688int size, ret, fd;
36719342 689const char v2sig[12] = "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A";
a3c86431
TL
690uschar *iptype; /* To display debug info */
691struct timeval tv;
a3bddaa8
TL
692socklen_t vslen = 0;
693struct timeval tvtmp;
694
695vslen = sizeof(struct timeval);
a3c86431
TL
696
697fd = fileno(smtp_in);
698
a3bddaa8
TL
699/* Save current socket timeout values */
700get_ok = getsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, (char *)&tvtmp,
701 &vslen);
702
a3c86431
TL
703/* Proxy Protocol host must send header within a short time
704(default 3 seconds) or it's considered invalid */
705tv.tv_sec = PROXY_NEGOTIATION_TIMEOUT_SEC;
706tv.tv_usec = PROXY_NEGOTIATION_TIMEOUT_USEC;
707setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, (char *)&tv,
708 sizeof(struct timeval));
a3bddaa8 709
a3c86431
TL
710do
711 {
eb57651e
TL
712 /* The inbound host was declared to be a Proxy Protocol host, so
713 don't do a PEEK into the data, actually slurp it up. */
714 ret = recv(fd, &hdr, sizeof(hdr), 0);
a3c86431
TL
715 }
716 while (ret == -1 && errno == EINTR);
717
718if (ret == -1)
a3bddaa8
TL
719 {
720 restore_socket_timeout(fd, get_ok, tvtmp, vslen);
a3c86431 721 return (errno == EAGAIN) ? 0 : ERRNO_PROXYFAIL;
a3bddaa8 722 }
a3c86431
TL
723
724if (ret >= 16 &&
36719342 725 memcmp(&hdr.v2, v2sig, 12) == 0)
a3c86431 726 {
36719342
TL
727 uint8_t ver, cmd;
728
729 /* May 2014: haproxy combined the version and command into one byte to
730 allow two full bytes for the length field in order to proxy SSL
731 connections. SSL Proxy is not supported in this version of Exim, but
732 must still seperate values here. */
733 ver = (hdr.v2.ver_cmd & 0xf0) >> 4;
734 cmd = (hdr.v2.ver_cmd & 0x0f);
735
736 if (ver != 0x02)
737 {
738 DEBUG(D_receive) debug_printf("Invalid Proxy Protocol version: %d\n", ver);
739 goto proxyfail;
740 }
a3c86431 741 DEBUG(D_receive) debug_printf("Detected PROXYv2 header\n");
36719342 742 /* The v2 header will always be 16 bytes per the spec. */
a3c86431
TL
743 size = 16 + hdr.v2.len;
744 if (ret < size)
745 {
36719342
TL
746 DEBUG(D_receive) debug_printf("Truncated or too large PROXYv2 header (%d/%d)\n",
747 ret, size);
a3c86431
TL
748 goto proxyfail;
749 }
36719342 750 switch (cmd)
a3c86431
TL
751 {
752 case 0x01: /* PROXY command */
753 switch (hdr.v2.fam)
754 {
eb57651e
TL
755 case 0x11: /* TCPv4 address type */
756 iptype = US"IPv4";
757 tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.src_addr;
758 inet_ntop(AF_INET, &(tmpaddr.sin_addr), (char *)&tmpip, sizeof(tmpip));
759 if (!string_is_ip_address(US tmpip,NULL))
760 {
761 DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
a3c86431 762 return ERRNO_PROXYFAIL;
eb57651e
TL
763 }
764 proxy_host_address = sender_host_address;
765 sender_host_address = string_copy(US tmpip);
766 tmpport = ntohs(hdr.v2.addr.ip4.src_port);
767 proxy_host_port = sender_host_port;
768 sender_host_port = tmpport;
769 /* Save dest ip/port */
770 tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.dst_addr;
771 inet_ntop(AF_INET, &(tmpaddr.sin_addr), (char *)&tmpip, sizeof(tmpip));
772 if (!string_is_ip_address(US tmpip,NULL))
773 {
774 DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype);
775 return ERRNO_PROXYFAIL;
776 }
777 proxy_target_address = string_copy(US tmpip);
778 tmpport = ntohs(hdr.v2.addr.ip4.dst_port);
779 proxy_target_port = tmpport;
a3c86431 780 goto done;
eb57651e
TL
781 case 0x21: /* TCPv6 address type */
782 iptype = US"IPv6";
783 memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.src_addr, 16);
784 inet_ntop(AF_INET6, &(tmpaddr6.sin6_addr), (char *)&tmpip6, sizeof(tmpip6));
785 if (!string_is_ip_address(US tmpip6,NULL))
786 {
787 DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
788 return ERRNO_PROXYFAIL;
789 }
790 proxy_host_address = sender_host_address;
791 sender_host_address = string_copy(US tmpip6);
792 tmpport = ntohs(hdr.v2.addr.ip6.src_port);
793 proxy_host_port = sender_host_port;
794 sender_host_port = tmpport;
795 /* Save dest ip/port */
796 memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.dst_addr, 16);
797 inet_ntop(AF_INET6, &(tmpaddr6.sin6_addr), (char *)&tmpip6, sizeof(tmpip6));
798 if (!string_is_ip_address(US tmpip6,NULL))
799 {
800 DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype);
a3c86431 801 return ERRNO_PROXYFAIL;
eb57651e
TL
802 }
803 proxy_target_address = string_copy(US tmpip6);
804 tmpport = ntohs(hdr.v2.addr.ip6.dst_port);
805 proxy_target_port = tmpport;
a3c86431 806 goto done;
eb57651e
TL
807 default:
808 DEBUG(D_receive)
809 debug_printf("Unsupported PROXYv2 connection type: 0x%02x\n",
810 hdr.v2.fam);
811 goto proxyfail;
a3c86431
TL
812 }
813 /* Unsupported protocol, keep local connection address */
814 break;
815 case 0x00: /* LOCAL command */
816 /* Keep local connection address for LOCAL */
817 break;
818 default:
eb57651e 819 DEBUG(D_receive)
36719342 820 debug_printf("Unsupported PROXYv2 command: 0x%x\n", cmd);
a3c86431
TL
821 goto proxyfail;
822 }
823 }
824else if (ret >= 8 &&
825 memcmp(hdr.v1.line, "PROXY", 5) == 0)
826 {
827 uschar *p = string_copy(hdr.v1.line);
828 uschar *end = memchr(p, '\r', ret - 1);
829 uschar *sp; /* Utility variables follow */
830 int tmp_port;
831 char *endc;
832
833 if (!end || end[1] != '\n')
834 {
835 DEBUG(D_receive) debug_printf("Partial or invalid PROXY header\n");
836 goto proxyfail;
837 }
838 *end = '\0'; /* Terminate the string */
839 size = end + 2 - hdr.v1.line; /* Skip header + CRLF */
840 DEBUG(D_receive) debug_printf("Detected PROXYv1 header\n");
841 /* Step through the string looking for the required fields. Ensure
842 strict adherance to required formatting, exit for any error. */
843 p += 5;
844 if (!isspace(*(p++)))
845 {
846 DEBUG(D_receive) debug_printf("Missing space after PROXY command\n");
847 goto proxyfail;
848 }
849 if (!Ustrncmp(p, CCS"TCP4", 4))
850 iptype = US"IPv4";
851 else if (!Ustrncmp(p,CCS"TCP6", 4))
852 iptype = US"IPv6";
853 else if (!Ustrncmp(p,CCS"UNKNOWN", 7))
854 {
855 iptype = US"Unknown";
856 goto done;
857 }
858 else
859 {
860 DEBUG(D_receive) debug_printf("Invalid TCP type\n");
861 goto proxyfail;
862 }
863
864 p += Ustrlen(iptype);
865 if (!isspace(*(p++)))
866 {
867 DEBUG(D_receive) debug_printf("Missing space after TCP4/6 command\n");
868 goto proxyfail;
869 }
870 /* Find the end of the arg */
871 if ((sp = Ustrchr(p, ' ')) == NULL)
872 {
873 DEBUG(D_receive)
874 debug_printf("Did not find proxied src %s\n", iptype);
875 goto proxyfail;
876 }
877 *sp = '\0';
878 if(!string_is_ip_address(p,NULL))
879 {
880 DEBUG(D_receive)
881 debug_printf("Proxied src arg is not an %s address\n", iptype);
882 goto proxyfail;
883 }
a3bddaa8 884 proxy_host_address = sender_host_address;
a3c86431
TL
885 sender_host_address = p;
886 p = sp + 1;
887 if ((sp = Ustrchr(p, ' ')) == NULL)
888 {
889 DEBUG(D_receive)
890 debug_printf("Did not find proxy dest %s\n", iptype);
891 goto proxyfail;
892 }
893 *sp = '\0';
894 if(!string_is_ip_address(p,NULL))
895 {
896 DEBUG(D_receive)
897 debug_printf("Proxy dest arg is not an %s address\n", iptype);
898 goto proxyfail;
899 }
eb57651e 900 proxy_target_address = p;
a3c86431
TL
901 p = sp + 1;
902 if ((sp = Ustrchr(p, ' ')) == NULL)
903 {
904 DEBUG(D_receive) debug_printf("Did not find proxied src port\n");
905 goto proxyfail;
906 }
907 *sp = '\0';
908 tmp_port = strtol(CCS p,&endc,10);
909 if (*endc || tmp_port == 0)
910 {
911 DEBUG(D_receive)
912 debug_printf("Proxied src port '%s' not an integer\n", p);
913 goto proxyfail;
914 }
a3bddaa8 915 proxy_host_port = sender_host_port;
a3c86431
TL
916 sender_host_port = tmp_port;
917 p = sp + 1;
918 if ((sp = Ustrchr(p, '\0')) == NULL)
919 {
920 DEBUG(D_receive) debug_printf("Did not find proxy dest port\n");
921 goto proxyfail;
922 }
923 tmp_port = strtol(CCS p,&endc,10);
924 if (*endc || tmp_port == 0)
925 {
926 DEBUG(D_receive)
927 debug_printf("Proxy dest port '%s' not an integer\n", p);
928 goto proxyfail;
929 }
eb57651e 930 proxy_target_port = tmp_port;
a3c86431
TL
931 /* Already checked for /r /n above. Good V1 header received. */
932 goto done;
933 }
934else
935 {
936 /* Wrong protocol */
eb57651e 937 DEBUG(D_receive) debug_printf("Invalid proxy protocol version negotiation\n");
a3c86431
TL
938 goto proxyfail;
939 }
940
941proxyfail:
a3bddaa8 942restore_socket_timeout(fd, get_ok, tvtmp, vslen);
a3c86431 943/* Don't flush any potential buffer contents. Any input should cause a
eb57651e 944 synchronization failure */
a3c86431
TL
945return FALSE;
946
947done:
a3bddaa8 948restore_socket_timeout(fd, get_ok, tvtmp, vslen);
a3c86431 949DEBUG(D_receive)
eb57651e 950 debug_printf("Valid %s sender from Proxy Protocol header\n", iptype);
a3c86431
TL
951return proxy_session;
952}
953#endif
954
059ec3d9
PH
955/*************************************************
956* Read one command line *
957*************************************************/
958
959/* Strictly, SMTP commands coming over the net are supposed to end with CRLF.
960There are sites that don't do this, and in any case internal SMTP probably
961should check only for LF. Consequently, we check here for LF only. The line
962ends up with [CR]LF removed from its end. If we get an overlong line, treat as
3ee512ff
PH
963an unknown command. The command is read into the global smtp_cmd_buffer so that
964it is available via $smtp_command.
059ec3d9
PH
965
966The character reading routine sets up a timeout for each block actually read
967from the input (which may contain more than one command). We set up a special
968signal handler that closes down the session on a timeout. Control does not
969return when it runs.
970
971Arguments:
972 check_sync if TRUE, check synchronization rules if global option is TRUE
973
974Returns: a code identifying the command (enumerated above)
975*/
976
977static int
978smtp_read_command(BOOL check_sync)
979{
980int c;
981int ptr = 0;
982smtp_cmd_list *p;
983BOOL hadnull = FALSE;
984
985os_non_restarting_signal(SIGALRM, command_timeout_handler);
986
987while ((c = (receive_getc)()) != '\n' && c != EOF)
988 {
3ee512ff 989 if (ptr >= smtp_cmd_buffer_size)
059ec3d9
PH
990 {
991 os_non_restarting_signal(SIGALRM, sigalrm_handler);
992 return OTHER_CMD;
993 }
994 if (c == 0)
995 {
996 hadnull = TRUE;
997 c = '?';
998 }
3ee512ff 999 smtp_cmd_buffer[ptr++] = c;
059ec3d9
PH
1000 }
1001
1002receive_linecount++; /* For BSMTP errors */
1003os_non_restarting_signal(SIGALRM, sigalrm_handler);
1004
1005/* If hit end of file, return pseudo EOF command. Whether we have a
1006part-line already read doesn't matter, since this is an error state. */
1007
1008if (c == EOF) return EOF_CMD;
1009
1010/* Remove any CR and white space at the end of the line, and terminate the
1011string. */
1012
3ee512ff
PH
1013while (ptr > 0 && isspace(smtp_cmd_buffer[ptr-1])) ptr--;
1014smtp_cmd_buffer[ptr] = 0;
059ec3d9 1015
3ee512ff 1016DEBUG(D_receive) debug_printf("SMTP<< %s\n", smtp_cmd_buffer);
059ec3d9
PH
1017
1018/* NULLs are not allowed in SMTP commands */
1019
1020if (hadnull) return BADCHAR_CMD;
1021
1022/* Scan command list and return identity, having set the data pointer
1023to the start of the actual data characters. Check for SMTP synchronization
1024if required. */
1025
1026for (p = cmd_list; p < cmd_list_end; p++)
1027 {
a3c86431
TL
1028 #ifdef EXPERIMENTAL_PROXY
1029 /* Only allow QUIT command if Proxy Protocol parsing failed */
1030 if (proxy_session && proxy_session_failed)
1031 {
1032 if (p->cmd != QUIT_CMD)
1033 continue;
1034 }
1035 #endif
2f460950
JH
1036 if ( p->len
1037 && strncmpic(smtp_cmd_buffer, US p->name, p->len) == 0
1038 && ( smtp_cmd_buffer[p->len-1] == ':' /* "mail from:" or "rcpt to:" */
1039 || smtp_cmd_buffer[p->len] == 0
1040 || smtp_cmd_buffer[p->len] == ' '
1041 ) )
059ec3d9
PH
1042 {
1043 if (smtp_inptr < smtp_inend && /* Outstanding input */
1044 p->cmd < sync_cmd_limit && /* Command should sync */
1045 check_sync && /* Local flag set */
1046 smtp_enforce_sync && /* Global flag set */
1047 sender_host_address != NULL && /* Not local input */
1048 !sender_host_notsocket) /* Really is a socket */
1049 return BADSYN_CMD;
1050
ca86f471
PH
1051 /* The variables $smtp_command and $smtp_command_argument point into the
1052 unmodified input buffer. A copy of the latter is taken for actual
1053 processing, so that it can be chopped up into separate parts if necessary,
1054 for example, when processing a MAIL command options such as SIZE that can
1055 follow the sender address. */
059ec3d9 1056
3ee512ff 1057 smtp_cmd_argument = smtp_cmd_buffer + p->len;
ca86f471
PH
1058 while (isspace(*smtp_cmd_argument)) smtp_cmd_argument++;
1059 Ustrcpy(smtp_data_buffer, smtp_cmd_argument);
1060 smtp_cmd_data = smtp_data_buffer;
059ec3d9
PH
1061
1062 /* Count non-mail commands from those hosts that are controlled in this
1063 way. The default is all hosts. We don't waste effort checking the list
1064 until we get a non-mail command, but then cache the result to save checking
1065 again. If there's a DEFER while checking the host, assume it's in the list.
1066
1067 Note that one instance of RSET, EHLO/HELO, and STARTTLS is allowed at the
1068 start of each incoming message by fiddling with the value in the table. */
1069
1070 if (!p->is_mail_cmd)
1071 {
1072 if (count_nonmail == TRUE_UNSET) count_nonmail =
1073 verify_check_host(&smtp_accept_max_nonmail_hosts) != FAIL;
1074 if (count_nonmail && ++nonmail_command_count > smtp_accept_max_nonmail)
1075 return TOO_MANY_NONMAIL_CMD;
1076 }
1077
ca86f471
PH
1078 /* If there is data for a command that does not expect it, generate the
1079 error here. */
059ec3d9 1080
ca86f471 1081 return (p->has_arg || *smtp_cmd_data == 0)? p->cmd : BADARG_CMD;
059ec3d9
PH
1082 }
1083 }
1084
a3c86431
TL
1085#ifdef EXPERIMENTAL_PROXY
1086/* Only allow QUIT command if Proxy Protocol parsing failed */
1087if (proxy_session && proxy_session_failed)
1088 return PROXY_FAIL_IGNORE_CMD;
1089#endif
1090
059ec3d9
PH
1091/* Enforce synchronization for unknown commands */
1092
1093if (smtp_inptr < smtp_inend && /* Outstanding input */
1094 check_sync && /* Local flag set */
1095 smtp_enforce_sync && /* Global flag set */
1096 sender_host_address != NULL && /* Not local input */
1097 !sender_host_notsocket) /* Really is a socket */
1098 return BADSYN_CMD;
1099
1100return OTHER_CMD;
1101}
1102
1103
1104
1105/*************************************************
a14e5636
PH
1106* Recheck synchronization *
1107*************************************************/
1108
1109/* Synchronization checks can never be perfect because a packet may be on its
1110way but not arrived when the check is done. Such checks can in any case only be
1111done when TLS is not in use. Normally, the checks happen when commands are
1112read: Exim ensures that there is no more input in the input buffer. In normal
1113cases, the response to the command will be fast, and there is no further check.
1114
1115However, for some commands an ACL is run, and that can include delays. In those
1116cases, it is useful to do another check on the input just before sending the
1117response. This also applies at the start of a connection. This function does
1118that check by means of the select() function, as long as the facility is not
1119disabled or inappropriate. A failure of select() is ignored.
1120
1121When there is unwanted input, we read it so that it appears in the log of the
1122error.
1123
1124Arguments: none
1125Returns: TRUE if all is well; FALSE if there is input pending
1126*/
1127
1128static BOOL
1129check_sync(void)
1130{
1131int fd, rc;
1132fd_set fds;
1133struct timeval tzero;
1134
1135if (!smtp_enforce_sync || sender_host_address == NULL ||
817d9f57 1136 sender_host_notsocket || tls_in.active >= 0)
a14e5636
PH
1137 return TRUE;
1138
1139fd = fileno(smtp_in);
1140FD_ZERO(&fds);
1141FD_SET(fd, &fds);
1142tzero.tv_sec = 0;
1143tzero.tv_usec = 0;
1144rc = select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &tzero);
1145
1146if (rc <= 0) return TRUE; /* Not ready to read */
1147rc = smtp_getc();
1148if (rc < 0) return TRUE; /* End of file or error */
1149
1150smtp_ungetc(rc);
1151rc = smtp_inend - smtp_inptr;
1152if (rc > 150) rc = 150;
1153smtp_inptr[rc] = 0;
1154return FALSE;
1155}
1156
1157
1158
1159/*************************************************
059ec3d9
PH
1160* Forced closedown of call *
1161*************************************************/
1162
1163/* This function is called from log.c when Exim is dying because of a serious
1164disaster, and also from some other places. If an incoming non-batched SMTP
1165channel is open, it swallows the rest of the incoming message if in the DATA
1166phase, sends the reply string, and gives an error to all subsequent commands
1167except QUIT. The existence of an SMTP call is detected by the non-NULLness of
1168smtp_in.
1169
8f128379
PH
1170Arguments:
1171 message SMTP reply string to send, excluding the code
1172
059ec3d9
PH
1173Returns: nothing
1174*/
1175
1176void
1177smtp_closedown(uschar *message)
1178{
1179if (smtp_in == NULL || smtp_batched_input) return;
1180receive_swallow_smtp();
1181smtp_printf("421 %s\r\n", message);
1182
1183for (;;)
1184 {
1185 switch(smtp_read_command(FALSE))
1186 {
1187 case EOF_CMD:
1188 return;
1189
1190 case QUIT_CMD:
1191 smtp_printf("221 %s closing connection\r\n", smtp_active_hostname);
1192 mac_smtp_fflush();
1193 return;
1194
1195 case RSET_CMD:
1196 smtp_printf("250 Reset OK\r\n");
1197 break;
1198
1199 default:
1200 smtp_printf("421 %s\r\n", message);
1201 break;
1202 }
1203 }
1204}
1205
1206
1207
1208
1209/*************************************************
1210* Set up connection info for logging *
1211*************************************************/
1212
1213/* This function is called when logging information about an SMTP connection.
1214It sets up appropriate source information, depending on the type of connection.
dac79d3e
PH
1215If sender_fullhost is NULL, we are at a very early stage of the connection;
1216just use the IP address.
059ec3d9
PH
1217
1218Argument: none
1219Returns: a string describing the connection
1220*/
1221
1222uschar *
1223smtp_get_connection_info(void)
1224{
dac79d3e
PH
1225uschar *hostname = (sender_fullhost == NULL)?
1226 sender_host_address : sender_fullhost;
1227
059ec3d9 1228if (host_checking)
dac79d3e 1229 return string_sprintf("SMTP connection from %s", hostname);
059ec3d9
PH
1230
1231if (sender_host_unknown || sender_host_notsocket)
1232 return string_sprintf("SMTP connection from %s", sender_ident);
1233
1234if (is_inetd)
dac79d3e 1235 return string_sprintf("SMTP connection from %s (via inetd)", hostname);
059ec3d9 1236
6c6d6e48 1237if (LOGGING(incoming_interface) && interface_address != NULL)
dac79d3e 1238 return string_sprintf("SMTP connection from %s I=[%s]:%d", hostname,
059ec3d9
PH
1239 interface_address, interface_port);
1240
dac79d3e 1241return string_sprintf("SMTP connection from %s", hostname);
059ec3d9
PH
1242}
1243
1244
1245
e45a1c37 1246#ifdef SUPPORT_TLS
887291d2
JH
1247/* Append TLS-related information to a log line
1248
1249Arguments:
1250 s String under construction: allocated string to extend, or NULL
1251 sizep Pointer to current allocation size (update on return), or NULL
1252 ptrp Pointer to index for new entries in string (update on return), or NULL
1253
1254Returns: Allocated string or NULL
1255*/
e45a1c37
JH
1256static uschar *
1257s_tlslog(uschar * s, int * sizep, int * ptrp)
1258{
1259 int size = sizep ? *sizep : 0;
1260 int ptr = ptrp ? *ptrp : 0;
1261
6c6d6e48 1262 if (LOGGING(tls_cipher) && tls_in.cipher != NULL)
e45a1c37 1263 s = string_append(s, &size, &ptr, 2, US" X=", tls_in.cipher);
6c6d6e48 1264 if (LOGGING(tls_certificate_verified) && tls_in.cipher != NULL)
e45a1c37
JH
1265 s = string_append(s, &size, &ptr, 2, US" CV=",
1266 tls_in.certificate_verified? "yes":"no");
6c6d6e48 1267 if (LOGGING(tls_peerdn) && tls_in.peerdn != NULL)
e45a1c37
JH
1268 s = string_append(s, &size, &ptr, 3, US" DN=\"",
1269 string_printing(tls_in.peerdn), US"\"");
6c6d6e48 1270 if (LOGGING(tls_sni) && tls_in.sni != NULL)
e45a1c37
JH
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
6c6d6e48 1302if (smtp_mailcmd_count > 0 || !LOGGING(smtp_no_mail))
b4ed4da0
PH
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 */
6c6d6e48
TF
2511 !LOGGING(smtp_incomplete_transaction))
2512 return;
059ec3d9
PH
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
6c6d6e48 2763 if (rc != FAIL || LOGGING(sender_verify_fail))
278c6e6c
PH
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;
aa7751be 3296 int c;
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
805bb5c3 3325 if (smtp_in_auth(au, &s, &ss) == OK)
b3ef41c9 3326 DEBUG(D_auth) debug_printf("tls auth succeeded\n");
805bb5c3
JH
3327 else
3328 DEBUG(D_auth) debug_printf("tls auth not succeeded\n");
b3ef41c9
JH
3329 break;
3330 }
3331 }
3332#endif
3333
059ec3d9
PH
3334 switch(smtp_read_command(TRUE))
3335 {
3336 /* The AUTH command is not permitted to occur inside a transaction, and may
c46782ef
PH
3337 occur successfully only once per connection. Actually, that isn't quite
3338 true. When TLS is started, all previous information about a connection must
3339 be discarded, so a new AUTH is permitted at that time.
3340
3341 AUTH may only be used when it has been advertised. However, it seems that
3342 there are clients that send AUTH when it hasn't been advertised, some of
3343 them even doing this after HELO. And there are MTAs that accept this. Sigh.
3344 So there's a get-out that allows this to happen.
059ec3d9
PH
3345
3346 AUTH is initially labelled as a "nonmail command" so that one occurrence
3347 doesn't get counted. We change the label here so that multiple failing
3348 AUTHS will eventually hit the nonmail threshold. */
3349
3350 case AUTH_CMD:
b4ed4da0 3351 HAD(SCH_AUTH);
059ec3d9
PH
3352 authentication_failed = TRUE;
3353 cmd_list[CMD_LIST_AUTH].is_mail_cmd = FALSE;
3354
c46782ef 3355 if (!auth_advertised && !allow_auth_unadvertised)
059ec3d9
PH
3356 {
3357 done = synprot_error(L_smtp_protocol_error, 503, NULL,
3358 US"AUTH command used when not advertised");
3359 break;
3360 }
b3ef41c9 3361 if (sender_host_authenticated)
059ec3d9
PH
3362 {
3363 done = synprot_error(L_smtp_protocol_error, 503, NULL,
3364 US"already authenticated");
3365 break;
3366 }
b3ef41c9 3367 if (sender_address)
059ec3d9
PH
3368 {
3369 done = synprot_error(L_smtp_protocol_error, 503, NULL,
3370 US"not permitted in mail transaction");
3371 break;
3372 }
3373
3374 /* Check the ACL */
3375
b3ef41c9 3376 if (acl_smtp_auth)
059ec3d9 3377 {
64ffc24f 3378 rc = acl_check(ACL_WHERE_AUTH, NULL, acl_smtp_auth, &user_msg, &log_msg);
059ec3d9
PH
3379 if (rc != OK)
3380 {
3381 done = smtp_handle_acl_fail(ACL_WHERE_AUTH, rc, user_msg, log_msg);
3382 break;
3383 }
3384 }
3385
3386 /* Find the name of the requested authentication mechanism. */
3387
ca86f471
PH
3388 s = smtp_cmd_data;
3389 while ((c = *smtp_cmd_data) != 0 && !isspace(c))
059ec3d9
PH
3390 {
3391 if (!isalnum(c) && c != '-' && c != '_')
3392 {
3393 done = synprot_error(L_smtp_syntax_error, 501, NULL,
3394 US"invalid character in authentication mechanism name");
3395 goto COMMAND_LOOP;
3396 }
ca86f471 3397 smtp_cmd_data++;
059ec3d9
PH
3398 }
3399
3400 /* If not at the end of the line, we must be at white space. Terminate the
3401 name and move the pointer on to any data that may be present. */
3402
ca86f471 3403 if (*smtp_cmd_data != 0)
059ec3d9 3404 {
ca86f471
PH
3405 *smtp_cmd_data++ = 0;
3406 while (isspace(*smtp_cmd_data)) smtp_cmd_data++;
059ec3d9
PH
3407 }
3408
3409 /* Search for an authentication mechanism which is configured for use
c46782ef
PH
3410 as a server and which has been advertised (unless, sigh, allow_auth_
3411 unadvertised is set). */
059ec3d9 3412
b3ef41c9 3413 for (au = auths; au; au = au->next)
059ec3d9 3414 if (strcmpic(s, au->public_name) == 0 && au->server &&
b3ef41c9
JH
3415 (au->advertised || allow_auth_unadvertised))
3416 break;
059ec3d9 3417
b3ef41c9 3418 if (au)
059ec3d9 3419 {
b3ef41c9 3420 c = smtp_in_auth(au, &s, &ss);
059ec3d9 3421
b3ef41c9
JH
3422 smtp_printf("%s\r\n", s);
3423 if (c != OK)
3424 log_write(0, LOG_MAIN|LOG_REJECT, "%s authenticator failed for %s: %s",
3425 au->name, host_and_ident(FALSE), ss);
059ec3d9 3426 }
b3ef41c9
JH
3427 else
3428 done = synprot_error(L_smtp_protocol_error, 504, NULL,
3429 string_sprintf("%s authentication mechanism not supported", s));
059ec3d9
PH
3430
3431 break; /* AUTH_CMD */
3432
3433 /* The HELO/EHLO commands are permitted to appear in the middle of a
3434 session as well as at the beginning. They have the effect of a reset in
3435 addition to their other functions. Their absence at the start cannot be
3436 taken to be an error.
3437
3438 RFC 2821 says:
3439
3440 If the EHLO command is not acceptable to the SMTP server, 501, 500,
3441 or 502 failure replies MUST be returned as appropriate. The SMTP
3442 server MUST stay in the same state after transmitting these replies
3443 that it was in before the EHLO was received.
3444
3445 Therefore, we do not do the reset until after checking the command for
3446 acceptability. This change was made for Exim release 4.11. Previously
3447 it did the reset first. */
3448
3449 case HELO_CMD:
b4ed4da0 3450 HAD(SCH_HELO);
059ec3d9
PH
3451 hello = US"HELO";
3452 esmtp = FALSE;
3453 goto HELO_EHLO;
3454
3455 case EHLO_CMD:
b4ed4da0 3456 HAD(SCH_EHLO);
059ec3d9
PH
3457 hello = US"EHLO";
3458 esmtp = TRUE;
3459
3460 HELO_EHLO: /* Common code for HELO and EHLO */
3461 cmd_list[CMD_LIST_HELO].is_mail_cmd = FALSE;
3462 cmd_list[CMD_LIST_EHLO].is_mail_cmd = FALSE;
3463
3464 /* Reject the HELO if its argument was invalid or non-existent. A
3465 successful check causes the argument to be saved in malloc store. */
3466
ca86f471 3467 if (!check_helo(smtp_cmd_data))
059ec3d9
PH
3468 {
3469 smtp_printf("501 Syntactically invalid %s argument(s)\r\n", hello);
3470
3471 log_write(0, LOG_MAIN|LOG_REJECT, "rejected %s from %s: syntactically "
3472 "invalid argument(s): %s", hello, host_and_ident(FALSE),
3ee512ff
PH
3473 (*smtp_cmd_argument == 0)? US"(no argument given)" :
3474 string_printing(smtp_cmd_argument));
059ec3d9
PH
3475
3476 if (++synprot_error_count > smtp_max_synprot_errors)
3477 {
3478 log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
3479 "syntax or protocol errors (last command was \"%s\")",
0ebc4d69 3480 host_and_ident(FALSE), string_printing(smtp_cmd_buffer));
059ec3d9
PH
3481 done = 1;
3482 }
3483
3484 break;
3485 }
3486
3487 /* If sender_host_unknown is true, we have got here via the -bs interface,
3488 not called from inetd. Otherwise, we are running an IP connection and the
3489 host address will be set. If the helo name is the primary name of this
3490 host and we haven't done a reverse lookup, force one now. If helo_required
3491 is set, ensure that the HELO name matches the actual host. If helo_verify
3492 is set, do the same check, but softly. */
3493
3494 if (!sender_host_unknown)
3495 {
3496 BOOL old_helo_verified = helo_verified;
ca86f471 3497 uschar *p = smtp_cmd_data;
059ec3d9
PH
3498
3499 while (*p != 0 && !isspace(*p)) { *p = tolower(*p); p++; }
3500 *p = 0;
3501
3502 /* Force a reverse lookup if HELO quoted something in helo_lookup_domains
3503 because otherwise the log can be confusing. */
3504
3505 if (sender_host_name == NULL &&
3506 (deliver_domain = sender_helo_name, /* set $domain */
55414b25 3507 match_isinlist(sender_helo_name, CUSS &helo_lookup_domains, 0,
059ec3d9
PH
3508 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL)) == OK)
3509 (void)host_name_lookup();
3510
3511 /* Rebuild the fullhost info to include the HELO name (and the real name
3512 if it was looked up.) */
3513
3514 host_build_sender_fullhost(); /* Rebuild */
3515 set_process_info("handling%s incoming connection from %s",
817d9f57 3516 (tls_in.active >= 0)? " TLS" : "", host_and_ident(FALSE));
059ec3d9
PH
3517
3518 /* Verify if configured. This doesn't give much security, but it does
d7b47fd0
PH
3519 make some people happy to be able to do it. If helo_required is set,
3520 (host matches helo_verify_hosts) failure forces rejection. If helo_verify
3521 is set (host matches helo_try_verify_hosts), it does not. This is perhaps
3522 now obsolescent, since the verification can now be requested selectively
3523 at ACL time. */
059ec3d9 3524
1705dd20 3525 helo_verified = helo_verify_failed = sender_helo_dnssec = FALSE;
059ec3d9
PH
3526 if (helo_required || helo_verify)
3527 {
d7b47fd0 3528 BOOL tempfail = !smtp_verify_helo();
059ec3d9
PH
3529 if (!helo_verified)
3530 {
3531 if (helo_required)
3532 {
3533 smtp_printf("%d %s argument does not match calling host\r\n",
3534 tempfail? 451 : 550, hello);
3535 log_write(0, LOG_MAIN|LOG_REJECT, "%srejected \"%s %s\" from %s",
3536 tempfail? "temporarily " : "",
3537 hello, sender_helo_name, host_and_ident(FALSE));
3538 helo_verified = old_helo_verified;
3539 break; /* End of HELO/EHLO processing */
3540 }
3541 HDEBUG(D_all) debug_printf("%s verification failed but host is in "
3542 "helo_try_verify_hosts\n", hello);
3543 }
3544 }
3545 }
3546
8523533c
TK
3547#ifdef EXPERIMENTAL_SPF
3548 /* set up SPF context */
3549 spf_init(sender_helo_name, sender_host_address);
3550#endif
3551
a14e5636
PH
3552 /* Apply an ACL check if one is defined; afterwards, recheck
3553 synchronization in case the client started sending in a delay. */
059ec3d9
PH
3554
3555 if (acl_smtp_helo != NULL)
3556 {
64ffc24f 3557 rc = acl_check(ACL_WHERE_HELO, NULL, acl_smtp_helo, &user_msg, &log_msg);
059ec3d9
PH
3558 if (rc != OK)
3559 {
3560 done = smtp_handle_acl_fail(ACL_WHERE_HELO, rc, user_msg, log_msg);
3561 sender_helo_name = NULL;
3562 host_build_sender_fullhost(); /* Rebuild */
3563 break;
3564 }
a14e5636 3565 else if (!check_sync()) goto SYNC_FAILURE;
059ec3d9
PH
3566 }
3567
4e88a19f
PH
3568 /* Generate an OK reply. The default string includes the ident if present,
3569 and also the IP address if present. Reflecting back the ident is intended
3570 as a deterrent to mail forgers. For maximum efficiency, and also because
3571 some broken systems expect each response to be in a single packet, arrange
3572 that the entire reply is sent in one write(). */
059ec3d9
PH
3573
3574 auth_advertised = FALSE;
3575 pipelining_advertised = FALSE;
d1a13eea 3576#ifdef SUPPORT_TLS
059ec3d9 3577 tls_advertised = FALSE;
d1a13eea 3578#endif
6c1c3d1d 3579 dsn_advertised = FALSE;
d1a13eea
JH
3580#ifdef EXPERIMENTAL_INTERNATIONAL
3581 smtputf8_advertised = FALSE;
3582#endif
059ec3d9 3583
d6a96edc 3584 smtp_code = US"250 "; /* Default response code plus space*/
4e88a19f
PH
3585 if (user_msg == NULL)
3586 {
3587 s = string_sprintf("%.3s %s Hello %s%s%s",
3588 smtp_code,
3589 smtp_active_hostname,
3590 (sender_ident == NULL)? US"" : sender_ident,
3591 (sender_ident == NULL)? US"" : US" at ",
3592 (sender_host_name == NULL)? sender_helo_name : sender_host_name);
3593
3594 ptr = Ustrlen(s);
3595 size = ptr + 1;
059ec3d9 3596
4e88a19f
PH
3597 if (sender_host_address != NULL)
3598 {
3599 s = string_cat(s, &size, &ptr, US" [", 2);
3600 s = string_cat(s, &size, &ptr, sender_host_address,
3601 Ustrlen(sender_host_address));
3602 s = string_cat(s, &size, &ptr, US"]", 1);
3603 }
3604 }
3605
d6a96edc
PH
3606 /* A user-supplied EHLO greeting may not contain more than one line. Note
3607 that the code returned by smtp_message_code() includes the terminating
3608 whitespace character. */
059ec3d9 3609
4e88a19f 3610 else
059ec3d9 3611 {
4e88a19f 3612 char *ss;
d6a96edc 3613 int codelen = 4;
4e88a19f 3614 smtp_message_code(&smtp_code, &codelen, &user_msg, NULL);
d6a96edc 3615 s = string_sprintf("%.*s%s", codelen, smtp_code, user_msg);
4e88a19f
PH
3616 if ((ss = strpbrk(CS s, "\r\n")) != NULL)
3617 {
3618 log_write(0, LOG_MAIN|LOG_PANIC, "EHLO/HELO response must not contain "
3619 "newlines: message truncated: %s", string_printing(s));
3620 *ss = 0;
3621 }
3622 ptr = Ustrlen(s);
3623 size = ptr + 1;
059ec3d9
PH
3624 }
3625
3626 s = string_cat(s, &size, &ptr, US"\r\n", 2);
3627
3628 /* If we received EHLO, we must create a multiline response which includes
3629 the functions supported. */
3630
3631 if (esmtp)
3632 {
3633 s[3] = '-';
3634
3635 /* I'm not entirely happy with this, as an MTA is supposed to check
3636 that it has enough room to accept a message of maximum size before
3637 it sends this. However, there seems little point in not sending it.
3638 The actual size check happens later at MAIL FROM time. By postponing it
3639 till then, VRFY and EXPN can be used after EHLO when space is short. */
3640
3641 if (thismessage_size_limit > 0)
3642 {
4e88a19f
PH
3643 sprintf(CS big_buffer, "%.3s-SIZE %d\r\n", smtp_code,
3644 thismessage_size_limit);
059ec3d9
PH
3645 s = string_cat(s, &size, &ptr, big_buffer, Ustrlen(big_buffer));
3646 }
3647 else
3648 {
4e88a19f
PH
3649 s = string_cat(s, &size, &ptr, smtp_code, 3);
3650 s = string_cat(s, &size, &ptr, US"-SIZE\r\n", 7);
059ec3d9
PH
3651 }
3652
3653 /* Exim does not do protocol conversion or data conversion. It is 8-bit
3654 clean; if it has an 8-bit character in its hand, it just sends it. It
3655 cannot therefore specify 8BITMIME and remain consistent with the RFCs.
3656 However, some users want this option simply in order to stop MUAs
3657 mangling messages that contain top-bit-set characters. It is therefore
3658 provided as an option. */
3659
3660 if (accept_8bitmime)
4e88a19f
PH
3661 {
3662 s = string_cat(s, &size, &ptr, smtp_code, 3);
3663 s = string_cat(s, &size, &ptr, US"-8BITMIME\r\n", 11);
3664 }
059ec3d9 3665
6c1c3d1d
WB
3666 /* Advertise DSN support if configured to do so. */
3667 if (verify_check_host(&dsn_advertise_hosts) != FAIL)
3668 {
3669 s = string_cat(s, &size, &ptr, smtp_code, 3);
3670 s = string_cat(s, &size, &ptr, US"-DSN\r\n", 6);
3671 dsn_advertised = TRUE;
3672 }
6c1c3d1d 3673
059ec3d9
PH
3674 /* Advertise ETRN if there's an ACL checking whether a host is
3675 permitted to issue it; a check is made when any host actually tries. */
3676
3677 if (acl_smtp_etrn != NULL)
3678 {
4e88a19f
PH
3679 s = string_cat(s, &size, &ptr, smtp_code, 3);
3680 s = string_cat(s, &size, &ptr, US"-ETRN\r\n", 7);
059ec3d9
PH
3681 }
3682
3683 /* Advertise EXPN if there's an ACL checking whether a host is
3684 permitted to issue it; a check is made when any host actually tries. */
3685
3686 if (acl_smtp_expn != NULL)
3687 {
4e88a19f
PH
3688 s = string_cat(s, &size, &ptr, smtp_code, 3);
3689 s = string_cat(s, &size, &ptr, US"-EXPN\r\n", 7);
059ec3d9
PH
3690 }
3691
3692 /* Exim is quite happy with pipelining, so let the other end know that
3693 it is safe to use it, unless advertising is disabled. */
3694
cf8b11a5
PH
3695 if (pipelining_enable &&
3696 verify_check_host(&pipelining_advertise_hosts) == OK)
059ec3d9 3697 {
4e88a19f
PH
3698 s = string_cat(s, &size, &ptr, smtp_code, 3);
3699 s = string_cat(s, &size, &ptr, US"-PIPELINING\r\n", 13);
059ec3d9
PH
3700 sync_cmd_limit = NON_SYNC_CMD_PIPELINING;
3701 pipelining_advertised = TRUE;
3702 }
3703
fd98a5c6 3704
059ec3d9
PH
3705 /* If any server authentication mechanisms are configured, advertise
3706 them if the current host is in auth_advertise_hosts. The problem with
3707 advertising always is that some clients then require users to
3708 authenticate (and aren't configurable otherwise) even though it may not
3709 be necessary (e.g. if the host is in host_accept_relay).
3710
3711 RFC 2222 states that SASL mechanism names contain only upper case
3712 letters, so output the names in upper case, though we actually recognize
3713 them in either case in the AUTH command. */
3714
b3ef41c9
JH
3715 if ( auths
3716#if defined(SUPPORT_TLS) && defined(AUTH_TLS)
3717 && !sender_host_authenticated
3718#endif
3719 && verify_check_host(&auth_advertise_hosts) == OK
3720 )
3721 {
3722 auth_instance *au;
3723 BOOL first = TRUE;
3724 for (au = auths; au; au = au->next)
3725 if (au->server && (au->advertise_condition == NULL ||
3726 expand_check_condition(au->advertise_condition, au->name,
3727 US"authenticator")))
3728 {
3729 int saveptr;
3730 if (first)
3731 {
3732 s = string_cat(s, &size, &ptr, smtp_code, 3);
3733 s = string_cat(s, &size, &ptr, US"-AUTH", 5);
3734 first = FALSE;
3735 auth_advertised = TRUE;
3736 }
3737 saveptr = ptr;
3738 s = string_cat(s, &size, &ptr, US" ", 1);
3739 s = string_cat(s, &size, &ptr, au->public_name,
3740 Ustrlen(au->public_name));
3741 while (++saveptr < ptr) s[saveptr] = toupper(s[saveptr]);
3742 au->advertised = TRUE;
3743 }
3744 else
3745 au->advertised = FALSE;
3746
3747 if (!first) s = string_cat(s, &size, &ptr, US"\r\n", 2);
3748 }
059ec3d9
PH
3749
3750 /* Advertise TLS (Transport Level Security) aka SSL (Secure Socket Layer)
3751 if it has been included in the binary, and the host matches
3752 tls_advertise_hosts. We must *not* advertise if we are already in a
3753 secure connection. */
3754
d1a13eea 3755#ifdef SUPPORT_TLS
817d9f57 3756 if (tls_in.active < 0 &&
059ec3d9
PH
3757 verify_check_host(&tls_advertise_hosts) != FAIL)
3758 {
4e88a19f
PH
3759 s = string_cat(s, &size, &ptr, smtp_code, 3);
3760 s = string_cat(s, &size, &ptr, US"-STARTTLS\r\n", 11);
059ec3d9
PH
3761 tls_advertised = TRUE;
3762 }
d1a13eea 3763#endif
059ec3d9 3764
d1a13eea 3765#ifndef DISABLE_PRDR
fd98a5c6 3766 /* Per Recipient Data Response, draft by Eric A. Hall extending RFC */
8ccd00b1
JH
3767 if (prdr_enable)
3768 {
fd98a5c6
JH
3769 s = string_cat(s, &size, &ptr, smtp_code, 3);
3770 s = string_cat(s, &size, &ptr, US"-PRDR\r\n", 7);
8ccd00b1 3771 }
d1a13eea
JH
3772#endif
3773
3774#ifdef EXPERIMENTAL_INTERNATIONAL
3775 if ( accept_8bitmime
3776 && verify_check_host(&smtputf8_advertise_hosts) != FAIL)
3777 {
3778 s = string_cat(s, &size, &ptr, smtp_code, 3);