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8f128379 | 1 | /* $Cambridge: exim/src/src/smtp_in.c,v 1.60 2007/08/22 10:10:23 ph10 Exp $ */ |
059ec3d9 PH |
2 | |
3 | /************************************************* | |
4 | * Exim - an Internet mail transport agent * | |
5 | *************************************************/ | |
6 | ||
184e8823 | 7 | /* Copyright (c) University of Cambridge 1995 - 2007 */ |
059ec3d9 PH |
8 | /* See the file NOTICE for conditions of use and distribution. */ |
9 | ||
10 | /* Functions for handling an incoming SMTP call. */ | |
11 | ||
12 | ||
13 | #include "exim.h" | |
14 | ||
15 | ||
16 | /* Initialize for TCP wrappers if so configured. It appears that the macro | |
17 | HAVE_IPV6 is used in some versions of the tcpd.h header, so we unset it before | |
18 | including that header, and restore its value afterwards. */ | |
19 | ||
20 | #ifdef USE_TCP_WRAPPERS | |
21 | ||
22 | #if HAVE_IPV6 | |
23 | #define EXIM_HAVE_IPV6 | |
24 | #endif | |
25 | #undef HAVE_IPV6 | |
26 | #include <tcpd.h> | |
27 | #undef HAVE_IPV6 | |
28 | #ifdef EXIM_HAVE_IPV6 | |
29 | #define HAVE_IPV6 TRUE | |
30 | #endif | |
31 | ||
32 | int allow_severity = LOG_INFO; | |
33 | int deny_severity = LOG_NOTICE; | |
34 | #endif | |
35 | ||
36 | ||
8d67ada3 PH |
37 | /* Size of buffer for reading SMTP commands. We used to use 512, as defined |
38 | by RFC 821. However, RFC 1869 specifies that this must be increased for SMTP | |
39 | commands that accept arguments, and this in particular applies to AUTH, where | |
40 | the data can be quite long. */ | |
059ec3d9 | 41 | |
3ee512ff | 42 | #define smtp_cmd_buffer_size 2048 |
059ec3d9 PH |
43 | |
44 | /* Size of buffer for reading SMTP incoming packets */ | |
45 | ||
46 | #define in_buffer_size 8192 | |
47 | ||
48 | /* Structure for SMTP command list */ | |
49 | ||
50 | typedef struct { | |
51 | char *name; | |
52 | int len; | |
53 | short int cmd; | |
54 | short int has_arg; | |
55 | short int is_mail_cmd; | |
56 | } smtp_cmd_list; | |
57 | ||
58 | /* Codes for identifying commands. We order them so that those that come first | |
59 | are those for which synchronization is always required. Checking this can help | |
60 | block some spam. */ | |
61 | ||
62 | enum { | |
63 | /* These commands are required to be synchronized, i.e. to be the last in a | |
64 | block of commands when pipelining. */ | |
65 | ||
66 | HELO_CMD, EHLO_CMD, DATA_CMD, /* These are listed in the pipelining */ | |
67 | VRFY_CMD, EXPN_CMD, NOOP_CMD, /* RFC as requiring synchronization */ | |
68 | ETRN_CMD, /* This by analogy with TURN from the RFC */ | |
69 | STARTTLS_CMD, /* Required by the STARTTLS RFC */ | |
70 | ||
71 | /* This is a dummy to identify the non-sync commands when pipelining */ | |
72 | ||
73 | NON_SYNC_CMD_PIPELINING, | |
74 | ||
75 | /* These commands need not be synchronized when pipelining */ | |
76 | ||
77 | MAIL_CMD, RCPT_CMD, RSET_CMD, | |
78 | ||
79 | /* This is a dummy to identify the non-sync commands when not pipelining */ | |
80 | ||
81 | NON_SYNC_CMD_NON_PIPELINING, | |
82 | ||
83 | /* I have been unable to find a statement about the use of pipelining | |
84 | with AUTH, so to be on the safe side it is here, though I kind of feel | |
85 | it should be up there with the synchronized commands. */ | |
86 | ||
87 | AUTH_CMD, | |
88 | ||
89 | /* I'm not sure about these, but I don't think they matter. */ | |
90 | ||
91 | QUIT_CMD, HELP_CMD, | |
92 | ||
93 | /* These are specials that don't correspond to actual commands */ | |
94 | ||
95 | EOF_CMD, OTHER_CMD, BADARG_CMD, BADCHAR_CMD, BADSYN_CMD, | |
96 | TOO_MANY_NONMAIL_CMD }; | |
97 | ||
98 | ||
b4ed4da0 PH |
99 | /* This is a convenience macro for adding the identity of an SMTP command |
100 | to the circular buffer that holds a list of the last n received. */ | |
101 | ||
102 | #define HAD(n) \ | |
103 | smtp_connection_had[smtp_ch_index++] = n; \ | |
104 | if (smtp_ch_index >= SMTP_HBUFF_SIZE) smtp_ch_index = 0 | |
105 | ||
059ec3d9 PH |
106 | |
107 | /************************************************* | |
108 | * Local static variables * | |
109 | *************************************************/ | |
110 | ||
111 | static auth_instance *authenticated_by; | |
112 | static BOOL auth_advertised; | |
113 | #ifdef SUPPORT_TLS | |
114 | static BOOL tls_advertised; | |
115 | #endif | |
116 | static BOOL esmtp; | |
117 | static BOOL helo_required = FALSE; | |
118 | static BOOL helo_verify = FALSE; | |
119 | static BOOL helo_seen; | |
120 | static BOOL helo_accept_junk; | |
121 | static BOOL count_nonmail; | |
122 | static BOOL pipelining_advertised; | |
2679d413 PH |
123 | static BOOL rcpt_smtp_response_same; |
124 | static BOOL rcpt_in_progress; | |
059ec3d9 | 125 | static int nonmail_command_count; |
8f128379 | 126 | static BOOL smtp_exit_function_called = 0; |
059ec3d9 PH |
127 | static int synprot_error_count; |
128 | static int unknown_command_count; | |
129 | static int sync_cmd_limit; | |
130 | static int smtp_write_error = 0; | |
131 | ||
2679d413 | 132 | static uschar *rcpt_smtp_response; |
ca86f471 PH |
133 | static uschar *smtp_data_buffer; |
134 | static uschar *smtp_cmd_data; | |
135 | ||
059ec3d9 PH |
136 | /* We need to know the position of RSET, HELO, EHLO, AUTH, and STARTTLS. Their |
137 | final fields of all except AUTH are forced TRUE at the start of a new message | |
138 | setup, to allow one of each between messages that is not counted as a nonmail | |
139 | command. (In fact, only one of HELO/EHLO is not counted.) Also, we have to | |
140 | allow a new EHLO after starting up TLS. | |
141 | ||
142 | AUTH is "falsely" labelled as a mail command initially, so that it doesn't get | |
143 | counted. However, the flag is changed when AUTH is received, so that multiple | |
144 | failing AUTHs will eventually hit the limit. After a successful AUTH, another | |
145 | AUTH is already forbidden. After a TLS session is started, AUTH's flag is again | |
146 | forced TRUE, to allow for the re-authentication that can happen at that point. | |
147 | ||
148 | QUIT is also "falsely" labelled as a mail command so that it doesn't up the | |
149 | count of non-mail commands and possibly provoke an error. */ | |
150 | ||
151 | static smtp_cmd_list cmd_list[] = { | |
152 | { "rset", sizeof("rset")-1, RSET_CMD, FALSE, FALSE }, /* First */ | |
153 | { "helo", sizeof("helo")-1, HELO_CMD, TRUE, FALSE }, | |
154 | { "ehlo", sizeof("ehlo")-1, EHLO_CMD, TRUE, FALSE }, | |
155 | { "auth", sizeof("auth")-1, AUTH_CMD, TRUE, TRUE }, | |
156 | #ifdef SUPPORT_TLS | |
157 | { "starttls", sizeof("starttls")-1, STARTTLS_CMD, FALSE, FALSE }, | |
158 | #endif | |
159 | ||
160 | /* If you change anything above here, also fix the definitions below. */ | |
161 | ||
162 | { "mail from:", sizeof("mail from:")-1, MAIL_CMD, TRUE, TRUE }, | |
163 | { "rcpt to:", sizeof("rcpt to:")-1, RCPT_CMD, TRUE, TRUE }, | |
164 | { "data", sizeof("data")-1, DATA_CMD, FALSE, TRUE }, | |
165 | { "quit", sizeof("quit")-1, QUIT_CMD, FALSE, TRUE }, | |
166 | { "noop", sizeof("noop")-1, NOOP_CMD, TRUE, FALSE }, | |
167 | { "etrn", sizeof("etrn")-1, ETRN_CMD, TRUE, FALSE }, | |
168 | { "vrfy", sizeof("vrfy")-1, VRFY_CMD, TRUE, FALSE }, | |
169 | { "expn", sizeof("expn")-1, EXPN_CMD, TRUE, FALSE }, | |
170 | { "help", sizeof("help")-1, HELP_CMD, TRUE, FALSE } | |
171 | }; | |
172 | ||
173 | static smtp_cmd_list *cmd_list_end = | |
174 | cmd_list + sizeof(cmd_list)/sizeof(smtp_cmd_list); | |
175 | ||
176 | #define CMD_LIST_RSET 0 | |
177 | #define CMD_LIST_HELO 1 | |
178 | #define CMD_LIST_EHLO 2 | |
179 | #define CMD_LIST_AUTH 3 | |
180 | #define CMD_LIST_STARTTLS 4 | |
181 | ||
b4ed4da0 PH |
182 | /* This list of names is used for performing the smtp_no_mail logging action. |
183 | It must be kept in step with the SCH_xxx enumerations. */ | |
184 | ||
185 | static uschar *smtp_names[] = | |
186 | { | |
187 | US"NONE", US"AUTH", US"DATA", US"EHLO", US"ETRN", US"EXPN", US"HELO", | |
188 | US"HELP", US"MAIL", US"NOOP", US"QUIT", US"RCPT", US"RSET", US"STARTTLS", | |
189 | US"VRFY" }; | |
190 | ||
059ec3d9 | 191 | static uschar *protocols[] = { |
981756db PH |
192 | US"local-smtp", /* HELO */ |
193 | US"local-smtps", /* The rare case EHLO->STARTTLS->HELO */ | |
194 | US"local-esmtp", /* EHLO */ | |
195 | US"local-esmtps", /* EHLO->STARTTLS->EHLO */ | |
196 | US"local-esmtpa", /* EHLO->AUTH */ | |
197 | US"local-esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */ | |
059ec3d9 PH |
198 | }; |
199 | ||
200 | #define pnormal 0 | |
981756db PH |
201 | #define pextend 2 |
202 | #define pcrpted 1 /* added to pextend or pnormal */ | |
203 | #define pauthed 2 /* added to pextend */ | |
059ec3d9 PH |
204 | #define pnlocal 6 /* offset to remove "local" */ |
205 | ||
206 | /* When reading SMTP from a remote host, we have to use our own versions of the | |
207 | C input-reading functions, in order to be able to flush the SMTP output only | |
208 | when about to read more data from the socket. This is the only way to get | |
209 | optimal performance when the client is using pipelining. Flushing for every | |
210 | command causes a separate packet and reply packet each time; saving all the | |
211 | responses up (when pipelining) combines them into one packet and one response. | |
212 | ||
213 | For simplicity, these functions are used for *all* SMTP input, not only when | |
214 | receiving over a socket. However, after setting up a secure socket (SSL), input | |
215 | is read via the OpenSSL library, and another set of functions is used instead | |
216 | (see tls.c). | |
217 | ||
218 | These functions are set in the receive_getc etc. variables and called with the | |
219 | same interface as the C functions. However, since there can only ever be | |
220 | one incoming SMTP call, we just use a single buffer and flags. There is no need | |
221 | to implement a complicated private FILE-like structure.*/ | |
222 | ||
223 | static uschar *smtp_inbuffer; | |
224 | static uschar *smtp_inptr; | |
225 | static uschar *smtp_inend; | |
226 | static int smtp_had_eof; | |
227 | static int smtp_had_error; | |
228 | ||
229 | ||
230 | /************************************************* | |
231 | * SMTP version of getc() * | |
232 | *************************************************/ | |
233 | ||
234 | /* This gets the next byte from the SMTP input buffer. If the buffer is empty, | |
235 | it flushes the output, and refills the buffer, with a timeout. The signal | |
236 | handler is set appropriately by the calling function. This function is not used | |
237 | after a connection has negotated itself into an TLS/SSL state. | |
238 | ||
239 | Arguments: none | |
240 | Returns: the next character or EOF | |
241 | */ | |
242 | ||
243 | int | |
244 | smtp_getc(void) | |
245 | { | |
246 | if (smtp_inptr >= smtp_inend) | |
247 | { | |
248 | int rc, save_errno; | |
249 | fflush(smtp_out); | |
250 | if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); | |
251 | rc = read(fileno(smtp_in), smtp_inbuffer, in_buffer_size); | |
252 | save_errno = errno; | |
253 | alarm(0); | |
254 | if (rc <= 0) | |
255 | { | |
256 | /* Must put the error text in fixed store, because this might be during | |
257 | header reading, where it releases unused store above the header. */ | |
258 | if (rc < 0) | |
259 | { | |
260 | smtp_had_error = save_errno; | |
261 | smtp_read_error = string_copy_malloc( | |
262 | string_sprintf(" (error: %s)", strerror(save_errno))); | |
263 | } | |
264 | else smtp_had_eof = 1; | |
265 | return EOF; | |
266 | } | |
267 | smtp_inend = smtp_inbuffer + rc; | |
268 | smtp_inptr = smtp_inbuffer; | |
269 | } | |
270 | return *smtp_inptr++; | |
271 | } | |
272 | ||
273 | ||
274 | ||
275 | /************************************************* | |
276 | * SMTP version of ungetc() * | |
277 | *************************************************/ | |
278 | ||
279 | /* Puts a character back in the input buffer. Only ever | |
280 | called once. | |
281 | ||
282 | Arguments: | |
283 | ch the character | |
284 | ||
285 | Returns: the character | |
286 | */ | |
287 | ||
288 | int | |
289 | smtp_ungetc(int ch) | |
290 | { | |
291 | *(--smtp_inptr) = ch; | |
292 | return ch; | |
293 | } | |
294 | ||
295 | ||
296 | ||
297 | ||
298 | /************************************************* | |
299 | * SMTP version of feof() * | |
300 | *************************************************/ | |
301 | ||
302 | /* Tests for a previous EOF | |
303 | ||
304 | Arguments: none | |
305 | Returns: non-zero if the eof flag is set | |
306 | */ | |
307 | ||
308 | int | |
309 | smtp_feof(void) | |
310 | { | |
311 | return smtp_had_eof; | |
312 | } | |
313 | ||
314 | ||
315 | ||
316 | ||
317 | /************************************************* | |
318 | * SMTP version of ferror() * | |
319 | *************************************************/ | |
320 | ||
321 | /* Tests for a previous read error, and returns with errno | |
322 | restored to what it was when the error was detected. | |
323 | ||
324 | Arguments: none | |
325 | Returns: non-zero if the error flag is set | |
326 | */ | |
327 | ||
328 | int | |
329 | smtp_ferror(void) | |
330 | { | |
331 | errno = smtp_had_error; | |
332 | return smtp_had_error; | |
333 | } | |
334 | ||
335 | ||
336 | ||
58eb016e PH |
337 | /************************************************* |
338 | * Test for characters in the SMTP buffer * | |
339 | *************************************************/ | |
340 | ||
341 | /* Used at the end of a message | |
342 | ||
343 | Arguments: none | |
344 | Returns: TRUE/FALSE | |
345 | */ | |
346 | ||
347 | BOOL | |
348 | smtp_buffered(void) | |
349 | { | |
350 | return smtp_inptr < smtp_inend; | |
351 | } | |
352 | ||
353 | ||
059ec3d9 PH |
354 | |
355 | /************************************************* | |
356 | * Write formatted string to SMTP channel * | |
357 | *************************************************/ | |
358 | ||
359 | /* This is a separate function so that we don't have to repeat everything for | |
360 | TLS support or debugging. It is global so that the daemon and the | |
361 | authentication functions can use it. It does not return any error indication, | |
362 | because major problems such as dropped connections won't show up till an output | |
363 | flush for non-TLS connections. The smtp_fflush() function is available for | |
364 | checking that: for convenience, TLS output errors are remembered here so that | |
365 | they are also picked up later by smtp_fflush(). | |
366 | ||
367 | Arguments: | |
368 | format format string | |
369 | ... optional arguments | |
370 | ||
371 | Returns: nothing | |
372 | */ | |
373 | ||
374 | void | |
375 | smtp_printf(char *format, ...) | |
376 | { | |
377 | va_list ap; | |
378 | ||
379 | DEBUG(D_receive) | |
380 | { | |
898d150f | 381 | uschar *cr, *end; |
059ec3d9 PH |
382 | va_start(ap, format); |
383 | (void) string_vformat(big_buffer, big_buffer_size, format, ap); | |
898d150f PH |
384 | va_end(ap); |
385 | end = big_buffer + Ustrlen(big_buffer); | |
386 | while ((cr = Ustrchr(big_buffer, '\r')) != NULL) /* lose CRs */ | |
387 | memmove(cr, cr + 1, (end--) - cr); | |
059ec3d9 PH |
388 | debug_printf("SMTP>> %s", big_buffer); |
389 | } | |
390 | ||
391 | va_start(ap, format); | |
2679d413 PH |
392 | if (!string_vformat(big_buffer, big_buffer_size, format, ap)) |
393 | { | |
394 | log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_printf()"); | |
395 | smtp_closedown(US"Unexpected error"); | |
396 | exim_exit(EXIT_FAILURE); | |
397 | } | |
398 | va_end(ap); | |
399 | ||
400 | /* If this is the first output for a (non-batch) RCPT command, see if all RCPTs | |
401 | have had the same. Note: this code is also present in smtp_respond(). It would | |
402 | be tidier to have it only in one place, but when it was added, it was easier to | |
403 | do it that way, so as not to have to mess with the code for the RCPT command, | |
404 | which sometimes uses smtp_printf() and sometimes smtp_respond(). */ | |
405 | ||
406 | if (rcpt_in_progress) | |
407 | { | |
408 | if (rcpt_smtp_response == NULL) | |
409 | rcpt_smtp_response = string_copy(big_buffer); | |
410 | else if (rcpt_smtp_response_same && | |
411 | Ustrcmp(rcpt_smtp_response, big_buffer) != 0) | |
412 | rcpt_smtp_response_same = FALSE; | |
413 | rcpt_in_progress = FALSE; | |
414 | } | |
059ec3d9 | 415 | |
2679d413 | 416 | /* Now write the string */ |
059ec3d9 PH |
417 | |
418 | #ifdef SUPPORT_TLS | |
419 | if (tls_active >= 0) | |
420 | { | |
059ec3d9 PH |
421 | if (tls_write(big_buffer, Ustrlen(big_buffer)) < 0) smtp_write_error = -1; |
422 | } | |
423 | else | |
424 | #endif | |
425 | ||
2679d413 | 426 | if (fprintf(smtp_out, "%s", big_buffer) < 0) smtp_write_error = -1; |
059ec3d9 PH |
427 | } |
428 | ||
429 | ||
430 | ||
431 | /************************************************* | |
432 | * Flush SMTP out and check for error * | |
433 | *************************************************/ | |
434 | ||
435 | /* This function isn't currently used within Exim (it detects errors when it | |
436 | tries to read the next SMTP input), but is available for use in local_scan(). | |
437 | For non-TLS connections, it flushes the output and checks for errors. For | |
438 | TLS-connections, it checks for a previously-detected TLS write error. | |
439 | ||
440 | Arguments: none | |
441 | Returns: 0 for no error; -1 after an error | |
442 | */ | |
443 | ||
444 | int | |
445 | smtp_fflush(void) | |
446 | { | |
447 | if (tls_active < 0 && fflush(smtp_out) != 0) smtp_write_error = -1; | |
448 | return smtp_write_error; | |
449 | } | |
450 | ||
451 | ||
452 | ||
453 | /************************************************* | |
454 | * SMTP command read timeout * | |
455 | *************************************************/ | |
456 | ||
457 | /* Signal handler for timing out incoming SMTP commands. This attempts to | |
458 | finish off tidily. | |
459 | ||
460 | Argument: signal number (SIGALRM) | |
461 | Returns: nothing | |
462 | */ | |
463 | ||
464 | static void | |
465 | command_timeout_handler(int sig) | |
466 | { | |
467 | sig = sig; /* Keep picky compilers happy */ | |
468 | log_write(L_lost_incoming_connection, | |
469 | LOG_MAIN, "SMTP command timeout on%s connection from %s", | |
470 | (tls_active >= 0)? " TLS" : "", | |
471 | host_and_ident(FALSE)); | |
472 | if (smtp_batched_input) | |
473 | moan_smtp_batch(NULL, "421 SMTP command timeout"); /* Does not return */ | |
8f128379 PH |
474 | smtp_notquit_exit(US"command-timeout", US"421", |
475 | US"%s: SMTP command timeout - closing connection", smtp_active_hostname); | |
059ec3d9 PH |
476 | exim_exit(EXIT_FAILURE); |
477 | } | |
478 | ||
479 | ||
480 | ||
481 | /************************************************* | |
482 | * SIGTERM received * | |
483 | *************************************************/ | |
484 | ||
485 | /* Signal handler for handling SIGTERM. Again, try to finish tidily. | |
486 | ||
487 | Argument: signal number (SIGTERM) | |
488 | Returns: nothing | |
489 | */ | |
490 | ||
491 | static void | |
492 | command_sigterm_handler(int sig) | |
493 | { | |
494 | sig = sig; /* Keep picky compilers happy */ | |
495 | log_write(0, LOG_MAIN, "%s closed after SIGTERM", smtp_get_connection_info()); | |
496 | if (smtp_batched_input) | |
497 | moan_smtp_batch(NULL, "421 SIGTERM received"); /* Does not return */ | |
8f128379 PH |
498 | smtp_notquit_exit(US"signal-exit", US"421", |
499 | US"%s: Service not available - closing connection", smtp_active_hostname); | |
059ec3d9 PH |
500 | exim_exit(EXIT_FAILURE); |
501 | } | |
502 | ||
503 | ||
504 | ||
a14e5636 | 505 | |
059ec3d9 PH |
506 | /************************************************* |
507 | * Read one command line * | |
508 | *************************************************/ | |
509 | ||
510 | /* Strictly, SMTP commands coming over the net are supposed to end with CRLF. | |
511 | There are sites that don't do this, and in any case internal SMTP probably | |
512 | should check only for LF. Consequently, we check here for LF only. The line | |
513 | ends up with [CR]LF removed from its end. If we get an overlong line, treat as | |
3ee512ff PH |
514 | an unknown command. The command is read into the global smtp_cmd_buffer so that |
515 | it is available via $smtp_command. | |
059ec3d9 PH |
516 | |
517 | The character reading routine sets up a timeout for each block actually read | |
518 | from the input (which may contain more than one command). We set up a special | |
519 | signal handler that closes down the session on a timeout. Control does not | |
520 | return when it runs. | |
521 | ||
522 | Arguments: | |
523 | check_sync if TRUE, check synchronization rules if global option is TRUE | |
524 | ||
525 | Returns: a code identifying the command (enumerated above) | |
526 | */ | |
527 | ||
528 | static int | |
529 | smtp_read_command(BOOL check_sync) | |
530 | { | |
531 | int c; | |
532 | int ptr = 0; | |
533 | smtp_cmd_list *p; | |
534 | BOOL hadnull = FALSE; | |
535 | ||
536 | os_non_restarting_signal(SIGALRM, command_timeout_handler); | |
537 | ||
538 | while ((c = (receive_getc)()) != '\n' && c != EOF) | |
539 | { | |
3ee512ff | 540 | if (ptr >= smtp_cmd_buffer_size) |
059ec3d9 PH |
541 | { |
542 | os_non_restarting_signal(SIGALRM, sigalrm_handler); | |
543 | return OTHER_CMD; | |
544 | } | |
545 | if (c == 0) | |
546 | { | |
547 | hadnull = TRUE; | |
548 | c = '?'; | |
549 | } | |
3ee512ff | 550 | smtp_cmd_buffer[ptr++] = c; |
059ec3d9 PH |
551 | } |
552 | ||
553 | receive_linecount++; /* For BSMTP errors */ | |
554 | os_non_restarting_signal(SIGALRM, sigalrm_handler); | |
555 | ||
556 | /* If hit end of file, return pseudo EOF command. Whether we have a | |
557 | part-line already read doesn't matter, since this is an error state. */ | |
558 | ||
559 | if (c == EOF) return EOF_CMD; | |
560 | ||
561 | /* Remove any CR and white space at the end of the line, and terminate the | |
562 | string. */ | |
563 | ||
3ee512ff PH |
564 | while (ptr > 0 && isspace(smtp_cmd_buffer[ptr-1])) ptr--; |
565 | smtp_cmd_buffer[ptr] = 0; | |
059ec3d9 | 566 | |
3ee512ff | 567 | DEBUG(D_receive) debug_printf("SMTP<< %s\n", smtp_cmd_buffer); |
059ec3d9 PH |
568 | |
569 | /* NULLs are not allowed in SMTP commands */ | |
570 | ||
571 | if (hadnull) return BADCHAR_CMD; | |
572 | ||
573 | /* Scan command list and return identity, having set the data pointer | |
574 | to the start of the actual data characters. Check for SMTP synchronization | |
575 | if required. */ | |
576 | ||
577 | for (p = cmd_list; p < cmd_list_end; p++) | |
578 | { | |
084efe8d PH |
579 | if (strncmpic(smtp_cmd_buffer, US p->name, p->len) == 0 && |
580 | (smtp_cmd_buffer[p->len-1] == ':' || /* "mail from:" or "rcpt to:" */ | |
581 | smtp_cmd_buffer[p->len] == 0 || | |
582 | smtp_cmd_buffer[p->len] == ' ')) | |
059ec3d9 PH |
583 | { |
584 | if (smtp_inptr < smtp_inend && /* Outstanding input */ | |
585 | p->cmd < sync_cmd_limit && /* Command should sync */ | |
586 | check_sync && /* Local flag set */ | |
587 | smtp_enforce_sync && /* Global flag set */ | |
588 | sender_host_address != NULL && /* Not local input */ | |
589 | !sender_host_notsocket) /* Really is a socket */ | |
590 | return BADSYN_CMD; | |
591 | ||
ca86f471 PH |
592 | /* The variables $smtp_command and $smtp_command_argument point into the |
593 | unmodified input buffer. A copy of the latter is taken for actual | |
594 | processing, so that it can be chopped up into separate parts if necessary, | |
595 | for example, when processing a MAIL command options such as SIZE that can | |
596 | follow the sender address. */ | |
059ec3d9 | 597 | |
3ee512ff | 598 | smtp_cmd_argument = smtp_cmd_buffer + p->len; |
ca86f471 PH |
599 | while (isspace(*smtp_cmd_argument)) smtp_cmd_argument++; |
600 | Ustrcpy(smtp_data_buffer, smtp_cmd_argument); | |
601 | smtp_cmd_data = smtp_data_buffer; | |
059ec3d9 PH |
602 | |
603 | /* Count non-mail commands from those hosts that are controlled in this | |
604 | way. The default is all hosts. We don't waste effort checking the list | |
605 | until we get a non-mail command, but then cache the result to save checking | |
606 | again. If there's a DEFER while checking the host, assume it's in the list. | |
607 | ||
608 | Note that one instance of RSET, EHLO/HELO, and STARTTLS is allowed at the | |
609 | start of each incoming message by fiddling with the value in the table. */ | |
610 | ||
611 | if (!p->is_mail_cmd) | |
612 | { | |
613 | if (count_nonmail == TRUE_UNSET) count_nonmail = | |
614 | verify_check_host(&smtp_accept_max_nonmail_hosts) != FAIL; | |
615 | if (count_nonmail && ++nonmail_command_count > smtp_accept_max_nonmail) | |
616 | return TOO_MANY_NONMAIL_CMD; | |
617 | } | |
618 | ||
ca86f471 PH |
619 | /* If there is data for a command that does not expect it, generate the |
620 | error here. */ | |
059ec3d9 | 621 | |
ca86f471 | 622 | return (p->has_arg || *smtp_cmd_data == 0)? p->cmd : BADARG_CMD; |
059ec3d9 PH |
623 | } |
624 | } | |
625 | ||
626 | /* Enforce synchronization for unknown commands */ | |
627 | ||
628 | if (smtp_inptr < smtp_inend && /* Outstanding input */ | |
629 | check_sync && /* Local flag set */ | |
630 | smtp_enforce_sync && /* Global flag set */ | |
631 | sender_host_address != NULL && /* Not local input */ | |
632 | !sender_host_notsocket) /* Really is a socket */ | |
633 | return BADSYN_CMD; | |
634 | ||
635 | return OTHER_CMD; | |
636 | } | |
637 | ||
638 | ||
639 | ||
a14e5636 PH |
640 | /************************************************* |
641 | * Recheck synchronization * | |
642 | *************************************************/ | |
643 | ||
644 | /* Synchronization checks can never be perfect because a packet may be on its | |
645 | way but not arrived when the check is done. Such checks can in any case only be | |
646 | done when TLS is not in use. Normally, the checks happen when commands are | |
647 | read: Exim ensures that there is no more input in the input buffer. In normal | |
648 | cases, the response to the command will be fast, and there is no further check. | |
649 | ||
650 | However, for some commands an ACL is run, and that can include delays. In those | |
651 | cases, it is useful to do another check on the input just before sending the | |
652 | response. This also applies at the start of a connection. This function does | |
653 | that check by means of the select() function, as long as the facility is not | |
654 | disabled or inappropriate. A failure of select() is ignored. | |
655 | ||
656 | When there is unwanted input, we read it so that it appears in the log of the | |
657 | error. | |
658 | ||
659 | Arguments: none | |
660 | Returns: TRUE if all is well; FALSE if there is input pending | |
661 | */ | |
662 | ||
663 | static BOOL | |
664 | check_sync(void) | |
665 | { | |
666 | int fd, rc; | |
667 | fd_set fds; | |
668 | struct timeval tzero; | |
669 | ||
670 | if (!smtp_enforce_sync || sender_host_address == NULL || | |
671 | sender_host_notsocket || tls_active >= 0) | |
672 | return TRUE; | |
673 | ||
674 | fd = fileno(smtp_in); | |
675 | FD_ZERO(&fds); | |
676 | FD_SET(fd, &fds); | |
677 | tzero.tv_sec = 0; | |
678 | tzero.tv_usec = 0; | |
679 | rc = select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &tzero); | |
680 | ||
681 | if (rc <= 0) return TRUE; /* Not ready to read */ | |
682 | rc = smtp_getc(); | |
683 | if (rc < 0) return TRUE; /* End of file or error */ | |
684 | ||
685 | smtp_ungetc(rc); | |
686 | rc = smtp_inend - smtp_inptr; | |
687 | if (rc > 150) rc = 150; | |
688 | smtp_inptr[rc] = 0; | |
689 | return FALSE; | |
690 | } | |
691 | ||
692 | ||
693 | ||
059ec3d9 PH |
694 | /************************************************* |
695 | * Forced closedown of call * | |
696 | *************************************************/ | |
697 | ||
698 | /* This function is called from log.c when Exim is dying because of a serious | |
699 | disaster, and also from some other places. If an incoming non-batched SMTP | |
700 | channel is open, it swallows the rest of the incoming message if in the DATA | |
701 | phase, sends the reply string, and gives an error to all subsequent commands | |
702 | except QUIT. The existence of an SMTP call is detected by the non-NULLness of | |
703 | smtp_in. | |
704 | ||
8f128379 PH |
705 | Arguments: |
706 | message SMTP reply string to send, excluding the code | |
707 | ||
059ec3d9 PH |
708 | Returns: nothing |
709 | */ | |
710 | ||
711 | void | |
712 | smtp_closedown(uschar *message) | |
713 | { | |
714 | if (smtp_in == NULL || smtp_batched_input) return; | |
715 | receive_swallow_smtp(); | |
716 | smtp_printf("421 %s\r\n", message); | |
717 | ||
718 | for (;;) | |
719 | { | |
720 | switch(smtp_read_command(FALSE)) | |
721 | { | |
722 | case EOF_CMD: | |
723 | return; | |
724 | ||
725 | case QUIT_CMD: | |
726 | smtp_printf("221 %s closing connection\r\n", smtp_active_hostname); | |
727 | mac_smtp_fflush(); | |
728 | return; | |
729 | ||
730 | case RSET_CMD: | |
731 | smtp_printf("250 Reset OK\r\n"); | |
732 | break; | |
733 | ||
734 | default: | |
735 | smtp_printf("421 %s\r\n", message); | |
736 | break; | |
737 | } | |
738 | } | |
739 | } | |
740 | ||
741 | ||
742 | ||
743 | ||
744 | /************************************************* | |
745 | * Set up connection info for logging * | |
746 | *************************************************/ | |
747 | ||
748 | /* This function is called when logging information about an SMTP connection. | |
749 | It sets up appropriate source information, depending on the type of connection. | |
dac79d3e PH |
750 | If sender_fullhost is NULL, we are at a very early stage of the connection; |
751 | just use the IP address. | |
059ec3d9 PH |
752 | |
753 | Argument: none | |
754 | Returns: a string describing the connection | |
755 | */ | |
756 | ||
757 | uschar * | |
758 | smtp_get_connection_info(void) | |
759 | { | |
dac79d3e PH |
760 | uschar *hostname = (sender_fullhost == NULL)? |
761 | sender_host_address : sender_fullhost; | |
762 | ||
059ec3d9 | 763 | if (host_checking) |
dac79d3e | 764 | return string_sprintf("SMTP connection from %s", hostname); |
059ec3d9 PH |
765 | |
766 | if (sender_host_unknown || sender_host_notsocket) | |
767 | return string_sprintf("SMTP connection from %s", sender_ident); | |
768 | ||
769 | if (is_inetd) | |
dac79d3e | 770 | return string_sprintf("SMTP connection from %s (via inetd)", hostname); |
059ec3d9 PH |
771 | |
772 | if ((log_extra_selector & LX_incoming_interface) != 0 && | |
773 | interface_address != NULL) | |
dac79d3e | 774 | return string_sprintf("SMTP connection from %s I=[%s]:%d", hostname, |
059ec3d9 PH |
775 | interface_address, interface_port); |
776 | ||
dac79d3e | 777 | return string_sprintf("SMTP connection from %s", hostname); |
059ec3d9 PH |
778 | } |
779 | ||
780 | ||
781 | ||
b4ed4da0 PH |
782 | /************************************************* |
783 | * Log lack of MAIL if so configured * | |
784 | *************************************************/ | |
785 | ||
786 | /* This function is called when an SMTP session ends. If the log selector | |
787 | smtp_no_mail is set, write a log line giving some details of what has happened | |
788 | in the SMTP session. | |
789 | ||
790 | Arguments: none | |
791 | Returns: nothing | |
792 | */ | |
793 | ||
794 | void | |
795 | smtp_log_no_mail(void) | |
796 | { | |
797 | int size, ptr, i; | |
798 | uschar *s, *sep; | |
799 | ||
800 | if (smtp_mailcmd_count > 0 || (log_extra_selector & LX_smtp_no_mail) == 0) | |
801 | return; | |
802 | ||
803 | s = NULL; | |
804 | size = ptr = 0; | |
805 | ||
806 | if (sender_host_authenticated != NULL) | |
807 | { | |
808 | s = string_append(s, &size, &ptr, 2, US" A=", sender_host_authenticated); | |
809 | if (authenticated_id != NULL) | |
810 | s = string_append(s, &size, &ptr, 2, US":", authenticated_id); | |
811 | } | |
812 | ||
813 | #ifdef SUPPORT_TLS | |
814 | if ((log_extra_selector & LX_tls_cipher) != 0 && tls_cipher != NULL) | |
815 | s = string_append(s, &size, &ptr, 2, US" X=", tls_cipher); | |
816 | if ((log_extra_selector & LX_tls_certificate_verified) != 0 && | |
817 | tls_cipher != NULL) | |
818 | s = string_append(s, &size, &ptr, 2, US" CV=", | |
819 | tls_certificate_verified? "yes":"no"); | |
820 | if ((log_extra_selector & LX_tls_peerdn) != 0 && tls_peerdn != NULL) | |
821 | s = string_append(s, &size, &ptr, 3, US" DN=\"", tls_peerdn, US"\""); | |
822 | #endif | |
823 | ||
824 | sep = (smtp_connection_had[SMTP_HBUFF_SIZE-1] != SCH_NONE)? | |
825 | US" C=..." : US" C="; | |
826 | for (i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++) | |
827 | { | |
828 | if (smtp_connection_had[i] != SCH_NONE) | |
829 | { | |
830 | s = string_append(s, &size, &ptr, 2, sep, | |
831 | smtp_names[smtp_connection_had[i]]); | |
832 | sep = US","; | |
833 | } | |
834 | } | |
835 | ||
836 | for (i = 0; i < smtp_ch_index; i++) | |
837 | { | |
838 | s = string_append(s, &size, &ptr, 2, sep, smtp_names[smtp_connection_had[i]]); | |
839 | sep = US","; | |
840 | } | |
841 | ||
842 | if (s != NULL) s[ptr] = 0; else s = US""; | |
843 | log_write(0, LOG_MAIN, "no MAIL in SMTP connection from %s D=%s%s", | |
844 | host_and_ident(FALSE), | |
845 | readconf_printtime(time(NULL) - smtp_connection_start), s); | |
846 | } | |
847 | ||
848 | ||
849 | ||
059ec3d9 PH |
850 | /************************************************* |
851 | * Check HELO line and set sender_helo_name * | |
852 | *************************************************/ | |
853 | ||
854 | /* Check the format of a HELO line. The data for HELO/EHLO is supposed to be | |
855 | the domain name of the sending host, or an ip literal in square brackets. The | |
856 | arrgument is placed in sender_helo_name, which is in malloc store, because it | |
857 | must persist over multiple incoming messages. If helo_accept_junk is set, this | |
858 | host is permitted to send any old junk (needed for some broken hosts). | |
859 | Otherwise, helo_allow_chars can be used for rogue characters in general | |
860 | (typically people want to let in underscores). | |
861 | ||
862 | Argument: | |
863 | s the data portion of the line (already past any white space) | |
864 | ||
865 | Returns: TRUE or FALSE | |
866 | */ | |
867 | ||
868 | static BOOL | |
869 | check_helo(uschar *s) | |
870 | { | |
871 | uschar *start = s; | |
872 | uschar *end = s + Ustrlen(s); | |
873 | BOOL yield = helo_accept_junk; | |
874 | ||
875 | /* Discard any previous helo name */ | |
876 | ||
877 | if (sender_helo_name != NULL) | |
878 | { | |
879 | store_free(sender_helo_name); | |
880 | sender_helo_name = NULL; | |
881 | } | |
882 | ||
883 | /* Skip tests if junk is permitted. */ | |
884 | ||
885 | if (!yield) | |
886 | { | |
887 | /* Allow the new standard form for IPv6 address literals, namely, | |
888 | [IPv6:....], and because someone is bound to use it, allow an equivalent | |
889 | IPv4 form. Allow plain addresses as well. */ | |
890 | ||
891 | if (*s == '[') | |
892 | { | |
893 | if (end[-1] == ']') | |
894 | { | |
895 | end[-1] = 0; | |
896 | if (strncmpic(s, US"[IPv6:", 6) == 0) | |
897 | yield = (string_is_ip_address(s+6, NULL) == 6); | |
898 | else if (strncmpic(s, US"[IPv4:", 6) == 0) | |
899 | yield = (string_is_ip_address(s+6, NULL) == 4); | |
900 | else | |
901 | yield = (string_is_ip_address(s+1, NULL) != 0); | |
902 | end[-1] = ']'; | |
903 | } | |
904 | } | |
905 | ||
906 | /* Non-literals must be alpha, dot, hyphen, plus any non-valid chars | |
907 | that have been configured (usually underscore - sigh). */ | |
908 | ||
909 | else if (*s != 0) | |
910 | { | |
911 | yield = TRUE; | |
912 | while (*s != 0) | |
913 | { | |
914 | if (!isalnum(*s) && *s != '.' && *s != '-' && | |
915 | Ustrchr(helo_allow_chars, *s) == NULL) | |
916 | { | |
917 | yield = FALSE; | |
918 | break; | |
919 | } | |
920 | s++; | |
921 | } | |
922 | } | |
923 | } | |
924 | ||
925 | /* Save argument if OK */ | |
926 | ||
927 | if (yield) sender_helo_name = string_copy_malloc(start); | |
928 | return yield; | |
929 | } | |
930 | ||
931 | ||
932 | ||
933 | ||
934 | ||
935 | /************************************************* | |
936 | * Extract SMTP command option * | |
937 | *************************************************/ | |
938 | ||
ca86f471 | 939 | /* This function picks the next option setting off the end of smtp_cmd_data. It |
059ec3d9 PH |
940 | is called for MAIL FROM and RCPT TO commands, to pick off the optional ESMTP |
941 | things that can appear there. | |
942 | ||
943 | Arguments: | |
944 | name point this at the name | |
945 | value point this at the data string | |
946 | ||
947 | Returns: TRUE if found an option | |
948 | */ | |
949 | ||
950 | static BOOL | |
951 | extract_option(uschar **name, uschar **value) | |
952 | { | |
953 | uschar *n; | |
ca86f471 | 954 | uschar *v = smtp_cmd_data + Ustrlen(smtp_cmd_data) - 1; |
059ec3d9 PH |
955 | while (isspace(*v)) v--; |
956 | v[1] = 0; | |
957 | ||
ca86f471 | 958 | while (v > smtp_cmd_data && *v != '=' && !isspace(*v)) v--; |
059ec3d9 PH |
959 | if (*v != '=') return FALSE; |
960 | ||
961 | n = v; | |
962 | while(isalpha(n[-1])) n--; | |
963 | ||
964 | if (n[-1] != ' ') return FALSE; | |
965 | ||
966 | n[-1] = 0; | |
967 | *name = n; | |
968 | *v++ = 0; | |
969 | *value = v; | |
970 | return TRUE; | |
971 | } | |
972 | ||
973 | ||
974 | ||
975 | ||
976 | ||
059ec3d9 PH |
977 | /************************************************* |
978 | * Reset for new message * | |
979 | *************************************************/ | |
980 | ||
981 | /* This function is called whenever the SMTP session is reset from | |
982 | within either of the setup functions. | |
983 | ||
984 | Argument: the stacking pool storage reset point | |
985 | Returns: nothing | |
986 | */ | |
987 | ||
988 | static void | |
989 | smtp_reset(void *reset_point) | |
990 | { | |
059ec3d9 PH |
991 | store_reset(reset_point); |
992 | recipients_list = NULL; | |
993 | rcpt_count = rcpt_defer_count = rcpt_fail_count = | |
994 | raw_recipients_count = recipients_count = recipients_list_max = 0; | |
2e0c1448 | 995 | message_linecount = 0; |
059ec3d9 | 996 | message_size = -1; |
71fafd95 | 997 | acl_added_headers = NULL; |
059ec3d9 | 998 | queue_only_policy = FALSE; |
2679d413 PH |
999 | rcpt_smtp_response = NULL; |
1000 | rcpt_smtp_response_same = TRUE; | |
1001 | rcpt_in_progress = FALSE; | |
69358f02 | 1002 | deliver_freeze = FALSE; /* Can be set by ACL */ |
6a3f1455 | 1003 | freeze_tell = freeze_tell_config; /* Can be set by ACL */ |
29aba418 | 1004 | fake_response = OK; /* Can be set by ACL */ |
6951ac6c | 1005 | #ifdef WITH_CONTENT_SCAN |
8523533c TK |
1006 | no_mbox_unspool = FALSE; /* Can be set by ACL */ |
1007 | #endif | |
69358f02 | 1008 | submission_mode = FALSE; /* Can be set by ACL */ |
8800895a | 1009 | suppress_local_fixups = FALSE; /* Can be set by ACL */ |
69358f02 PH |
1010 | active_local_from_check = local_from_check; /* Can be set by ACL */ |
1011 | active_local_sender_retain = local_sender_retain; /* Can be set by ACL */ | |
059ec3d9 | 1012 | sender_address = NULL; |
2fe1a124 | 1013 | submission_name = NULL; /* Can be set by ACL */ |
059ec3d9 PH |
1014 | raw_sender = NULL; /* After SMTP rewrite, before qualifying */ |
1015 | sender_address_unrewritten = NULL; /* Set only after verify rewrite */ | |
1016 | sender_verified_list = NULL; /* No senders verified */ | |
1017 | memset(sender_address_cache, 0, sizeof(sender_address_cache)); | |
1018 | memset(sender_domain_cache, 0, sizeof(sender_domain_cache)); | |
1019 | authenticated_sender = NULL; | |
8523533c TK |
1020 | #ifdef EXPERIMENTAL_BRIGHTMAIL |
1021 | bmi_run = 0; | |
1022 | bmi_verdicts = NULL; | |
1023 | #endif | |
fb2274d4 TK |
1024 | #ifdef EXPERIMENTAL_DOMAINKEYS |
1025 | dk_do_verify = 0; | |
1026 | #endif | |
8523533c TK |
1027 | #ifdef EXPERIMENTAL_SPF |
1028 | spf_header_comment = NULL; | |
1029 | spf_received = NULL; | |
8e669ac1 | 1030 | spf_result = NULL; |
8523533c TK |
1031 | spf_smtp_comment = NULL; |
1032 | #endif | |
059ec3d9 PH |
1033 | body_linecount = body_zerocount = 0; |
1034 | ||
870f6ba8 TF |
1035 | sender_rate = sender_rate_limit = sender_rate_period = NULL; |
1036 | ratelimiters_mail = NULL; /* Updated by ratelimit ACL condition */ | |
1037 | /* Note that ratelimiters_conn persists across resets. */ | |
1038 | ||
38a0a95f | 1039 | /* Reset message ACL variables */ |
47ca6d6c | 1040 | |
38a0a95f | 1041 | acl_var_m = NULL; |
059ec3d9 PH |
1042 | |
1043 | /* The message body variables use malloc store. They may be set if this is | |
1044 | not the first message in an SMTP session and the previous message caused them | |
1045 | to be referenced in an ACL. */ | |
1046 | ||
1047 | if (message_body != NULL) | |
1048 | { | |
1049 | store_free(message_body); | |
1050 | message_body = NULL; | |
1051 | } | |
1052 | ||
1053 | if (message_body_end != NULL) | |
1054 | { | |
1055 | store_free(message_body_end); | |
1056 | message_body_end = NULL; | |
1057 | } | |
1058 | ||
1059 | /* Warning log messages are also saved in malloc store. They are saved to avoid | |
1060 | repetition in the same message, but it seems right to repeat them for different | |
4e88a19f | 1061 | messages. */ |
059ec3d9 PH |
1062 | |
1063 | while (acl_warn_logged != NULL) | |
1064 | { | |
1065 | string_item *this = acl_warn_logged; | |
1066 | acl_warn_logged = acl_warn_logged->next; | |
1067 | store_free(this); | |
1068 | } | |
1069 | } | |
1070 | ||
1071 | ||
1072 | ||
1073 | ||
1074 | ||
1075 | /************************************************* | |
1076 | * Initialize for incoming batched SMTP message * | |
1077 | *************************************************/ | |
1078 | ||
1079 | /* This function is called from smtp_setup_msg() in the case when | |
1080 | smtp_batched_input is true. This happens when -bS is used to pass a whole batch | |
1081 | of messages in one file with SMTP commands between them. All errors must be | |
1082 | reported by sending a message, and only MAIL FROM, RCPT TO, and DATA are | |
1083 | relevant. After an error on a sender, or an invalid recipient, the remainder | |
1084 | of the message is skipped. The value of received_protocol is already set. | |
1085 | ||
1086 | Argument: none | |
1087 | Returns: > 0 message successfully started (reached DATA) | |
1088 | = 0 QUIT read or end of file reached | |
1089 | < 0 should not occur | |
1090 | */ | |
1091 | ||
1092 | static int | |
1093 | smtp_setup_batch_msg(void) | |
1094 | { | |
1095 | int done = 0; | |
1096 | void *reset_point = store_get(0); | |
1097 | ||
1098 | /* Save the line count at the start of each transaction - single commands | |
1099 | like HELO and RSET count as whole transactions. */ | |
1100 | ||
1101 | bsmtp_transaction_linecount = receive_linecount; | |
1102 | ||
1103 | if ((receive_feof)()) return 0; /* Treat EOF as QUIT */ | |
1104 | ||
1105 | smtp_reset(reset_point); /* Reset for start of message */ | |
1106 | ||
1107 | /* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE | |
1108 | value. The values are 2 larger than the required yield of the function. */ | |
1109 | ||
1110 | while (done <= 0) | |
1111 | { | |
1112 | uschar *errmess; | |
1113 | uschar *recipient = NULL; | |
1114 | int start, end, sender_domain, recipient_domain; | |
1115 | ||
1116 | switch(smtp_read_command(FALSE)) | |
1117 | { | |
1118 | /* The HELO/EHLO commands set sender_address_helo if they have | |
1119 | valid data; otherwise they are ignored, except that they do | |
1120 | a reset of the state. */ | |
1121 | ||
1122 | case HELO_CMD: | |
1123 | case EHLO_CMD: | |
1124 | ||
ca86f471 | 1125 | check_helo(smtp_cmd_data); |
059ec3d9 PH |
1126 | /* Fall through */ |
1127 | ||
1128 | case RSET_CMD: | |
1129 | smtp_reset(reset_point); | |
1130 | bsmtp_transaction_linecount = receive_linecount; | |
1131 | break; | |
1132 | ||
1133 | ||
1134 | /* The MAIL FROM command requires an address as an operand. All we | |
1135 | do here is to parse it for syntactic correctness. The form "<>" is | |
1136 | a special case which converts into an empty string. The start/end | |
1137 | pointers in the original are not used further for this address, as | |
1138 | it is the canonical extracted address which is all that is kept. */ | |
1139 | ||
1140 | case MAIL_CMD: | |
1141 | if (sender_address != NULL) | |
1142 | /* The function moan_smtp_batch() does not return. */ | |
3ee512ff | 1143 | moan_smtp_batch(smtp_cmd_buffer, "503 Sender already given"); |
059ec3d9 | 1144 | |
ca86f471 | 1145 | if (smtp_cmd_data[0] == 0) |
059ec3d9 | 1146 | /* The function moan_smtp_batch() does not return. */ |
3ee512ff | 1147 | moan_smtp_batch(smtp_cmd_buffer, "501 MAIL FROM must have an address operand"); |
059ec3d9 PH |
1148 | |
1149 | /* Reset to start of message */ | |
1150 | ||
1151 | smtp_reset(reset_point); | |
1152 | ||
1153 | /* Apply SMTP rewrite */ | |
1154 | ||
1155 | raw_sender = ((rewrite_existflags & rewrite_smtp) != 0)? | |
ca86f471 PH |
1156 | rewrite_one(smtp_cmd_data, rewrite_smtp|rewrite_smtp_sender, NULL, FALSE, |
1157 | US"", global_rewrite_rules) : smtp_cmd_data; | |
059ec3d9 PH |
1158 | |
1159 | /* Extract the address; the TRUE flag allows <> as valid */ | |
1160 | ||
1161 | raw_sender = | |
1162 | parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain, | |
1163 | TRUE); | |
1164 | ||
1165 | if (raw_sender == NULL) | |
1166 | /* The function moan_smtp_batch() does not return. */ | |
3ee512ff | 1167 | moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess); |
059ec3d9 PH |
1168 | |
1169 | sender_address = string_copy(raw_sender); | |
1170 | ||
1171 | /* Qualify unqualified sender addresses if permitted to do so. */ | |
1172 | ||
1173 | if (sender_domain == 0 && sender_address[0] != 0 && sender_address[0] != '@') | |
1174 | { | |
1175 | if (allow_unqualified_sender) | |
1176 | { | |
1177 | sender_address = rewrite_address_qualify(sender_address, FALSE); | |
1178 | DEBUG(D_receive) debug_printf("unqualified address %s accepted " | |
1179 | "and rewritten\n", raw_sender); | |
1180 | } | |
1181 | /* The function moan_smtp_batch() does not return. */ | |
3ee512ff | 1182 | else moan_smtp_batch(smtp_cmd_buffer, "501 sender address must contain " |
059ec3d9 PH |
1183 | "a domain"); |
1184 | } | |
1185 | break; | |
1186 | ||
1187 | ||
1188 | /* The RCPT TO command requires an address as an operand. All we do | |
1189 | here is to parse it for syntactic correctness. There may be any number | |
1190 | of RCPT TO commands, specifying multiple senders. We build them all into | |
1191 | a data structure that is in argc/argv format. The start/end values | |
1192 | given by parse_extract_address are not used, as we keep only the | |
1193 | extracted address. */ | |
1194 | ||
1195 | case RCPT_CMD: | |
1196 | if (sender_address == NULL) | |
1197 | /* The function moan_smtp_batch() does not return. */ | |
3ee512ff | 1198 | moan_smtp_batch(smtp_cmd_buffer, "503 No sender yet given"); |
059ec3d9 | 1199 | |
ca86f471 | 1200 | if (smtp_cmd_data[0] == 0) |
059ec3d9 | 1201 | /* The function moan_smtp_batch() does not return. */ |
3ee512ff | 1202 | moan_smtp_batch(smtp_cmd_buffer, "501 RCPT TO must have an address operand"); |
059ec3d9 PH |
1203 | |
1204 | /* Check maximum number allowed */ | |
1205 | ||
1206 | if (recipients_max > 0 && recipients_count + 1 > recipients_max) | |
1207 | /* The function moan_smtp_batch() does not return. */ | |
3ee512ff | 1208 | moan_smtp_batch(smtp_cmd_buffer, "%s too many recipients", |
059ec3d9 PH |
1209 | recipients_max_reject? "552": "452"); |
1210 | ||
1211 | /* Apply SMTP rewrite, then extract address. Don't allow "<>" as a | |
1212 | recipient address */ | |
1213 | ||
1214 | recipient = ((rewrite_existflags & rewrite_smtp) != 0)? | |
ca86f471 PH |
1215 | rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"", |
1216 | global_rewrite_rules) : smtp_cmd_data; | |
059ec3d9 PH |
1217 | |
1218 | /* rfc821_domains = TRUE; << no longer needed */ | |
1219 | recipient = parse_extract_address(recipient, &errmess, &start, &end, | |
1220 | &recipient_domain, FALSE); | |
1221 | /* rfc821_domains = FALSE; << no longer needed */ | |
1222 | ||
1223 | if (recipient == NULL) | |
1224 | /* The function moan_smtp_batch() does not return. */ | |
3ee512ff | 1225 | moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess); |
059ec3d9 PH |
1226 | |
1227 | /* If the recipient address is unqualified, qualify it if permitted. Then | |
1228 | add it to the list of recipients. */ | |
1229 | ||
1230 | if (recipient_domain == 0) | |
1231 | { | |
1232 | if (allow_unqualified_recipient) | |
1233 | { | |
1234 | DEBUG(D_receive) debug_printf("unqualified address %s accepted\n", | |
1235 | recipient); | |
1236 | recipient = rewrite_address_qualify(recipient, TRUE); | |
1237 | } | |
1238 | /* The function moan_smtp_batch() does not return. */ | |
3ee512ff | 1239 | else moan_smtp_batch(smtp_cmd_buffer, "501 recipient address must contain " |
059ec3d9 PH |
1240 | "a domain"); |
1241 | } | |
1242 | receive_add_recipient(recipient, -1); | |
1243 | break; | |
1244 | ||
1245 | ||
1246 | /* The DATA command is legal only if it follows successful MAIL FROM | |
1247 | and RCPT TO commands. This function is complete when a valid DATA | |
1248 | command is encountered. */ | |
1249 | ||
1250 | case DATA_CMD: | |
1251 | if (sender_address == NULL || recipients_count <= 0) | |
1252 | { | |
1253 | /* The function moan_smtp_batch() does not return. */ | |
1254 | if (sender_address == NULL) | |
3ee512ff | 1255 | moan_smtp_batch(smtp_cmd_buffer, |
059ec3d9 PH |
1256 | "503 MAIL FROM:<sender> command must precede DATA"); |
1257 | else | |
3ee512ff | 1258 | moan_smtp_batch(smtp_cmd_buffer, |
059ec3d9 PH |
1259 | "503 RCPT TO:<recipient> must precede DATA"); |
1260 | } | |
1261 | else | |
1262 | { | |
1263 | done = 3; /* DATA successfully achieved */ | |
1264 | message_ended = END_NOTENDED; /* Indicate in middle of message */ | |
1265 | } | |
1266 | break; | |
1267 | ||
1268 | ||
1269 | /* The VRFY, EXPN, HELP, ETRN, and NOOP commands are ignored. */ | |
1270 | ||
1271 | case VRFY_CMD: | |
1272 | case EXPN_CMD: | |
1273 | case HELP_CMD: | |
1274 | case NOOP_CMD: | |
1275 | case ETRN_CMD: | |
1276 | bsmtp_transaction_linecount = receive_linecount; | |
1277 | break; | |
1278 | ||
1279 | ||
1280 | case EOF_CMD: | |
1281 | case QUIT_CMD: | |
1282 | done = 2; | |
1283 | break; | |
1284 | ||
1285 | ||
1286 | case BADARG_CMD: | |
1287 | /* The function moan_smtp_batch() does not return. */ | |
3ee512ff | 1288 | moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected argument data"); |
059ec3d9 PH |
1289 | break; |
1290 | ||
1291 | ||
1292 | case BADCHAR_CMD: | |
1293 | /* The function moan_smtp_batch() does not return. */ | |
3ee512ff | 1294 | moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected NULL in SMTP command"); |
059ec3d9 PH |
1295 | break; |
1296 | ||
1297 | ||
1298 | default: | |
1299 | /* The function moan_smtp_batch() does not return. */ | |
3ee512ff | 1300 | moan_smtp_batch(smtp_cmd_buffer, "500 Command unrecognized"); |
059ec3d9 PH |
1301 | break; |
1302 | } | |
1303 | } | |
1304 | ||
1305 | return done - 2; /* Convert yield values */ | |
1306 | } | |
1307 | ||
1308 | ||
1309 | ||
1310 | ||
1311 | /************************************************* | |
1312 | * Start an SMTP session * | |
1313 | *************************************************/ | |
1314 | ||
1315 | /* This function is called at the start of an SMTP session. Thereafter, | |
1316 | smtp_setup_msg() is called to initiate each separate message. This | |
1317 | function does host-specific testing, and outputs the banner line. | |
1318 | ||
1319 | Arguments: none | |
1320 | Returns: FALSE if the session can not continue; something has | |
1321 | gone wrong, or the connection to the host is blocked | |
1322 | */ | |
1323 | ||
1324 | BOOL | |
1325 | smtp_start_session(void) | |
1326 | { | |
1327 | int size = 256; | |
4e88a19f PH |
1328 | int ptr, esclen; |
1329 | uschar *user_msg, *log_msg; | |
1330 | uschar *code, *esc; | |
059ec3d9 PH |
1331 | uschar *p, *s, *ss; |
1332 | ||
b4ed4da0 PH |
1333 | smtp_connection_start = time(NULL); |
1334 | for (smtp_ch_index = 0; smtp_ch_index < SMTP_HBUFF_SIZE; smtp_ch_index++) | |
1335 | smtp_connection_had[smtp_ch_index] = SCH_NONE; | |
1336 | smtp_ch_index = 0; | |
1337 | ||
00f00ca5 PH |
1338 | /* Default values for certain variables */ |
1339 | ||
059ec3d9 | 1340 | helo_seen = esmtp = helo_accept_junk = FALSE; |
b4ed4da0 | 1341 | smtp_mailcmd_count = 0; |
059ec3d9 PH |
1342 | count_nonmail = TRUE_UNSET; |
1343 | synprot_error_count = unknown_command_count = nonmail_command_count = 0; | |
1344 | smtp_delay_mail = smtp_rlm_base; | |
1345 | auth_advertised = FALSE; | |
1346 | pipelining_advertised = FALSE; | |
cf8b11a5 | 1347 | pipelining_enable = TRUE; |
059ec3d9 | 1348 | sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING; |
8f128379 | 1349 | smtp_exit_function_called = FALSE; /* For avoiding loop in not-quit exit */ |
059ec3d9 PH |
1350 | |
1351 | memset(sender_host_cache, 0, sizeof(sender_host_cache)); | |
1352 | ||
33d73e3b PH |
1353 | /* If receiving by -bs from a trusted user, or testing with -bh, we allow |
1354 | authentication settings from -oMaa to remain in force. */ | |
1355 | ||
1356 | if (!host_checking && !sender_host_notsocket) sender_host_authenticated = NULL; | |
059ec3d9 PH |
1357 | authenticated_by = NULL; |
1358 | ||
1359 | #ifdef SUPPORT_TLS | |
1360 | tls_cipher = tls_peerdn = NULL; | |
1361 | tls_advertised = FALSE; | |
1362 | #endif | |
1363 | ||
1364 | /* Reset ACL connection variables */ | |
1365 | ||
38a0a95f | 1366 | acl_var_c = NULL; |
059ec3d9 | 1367 | |
ca86f471 | 1368 | /* Allow for trailing 0 in the command and data buffers. */ |
3ee512ff | 1369 | |
ca86f471 | 1370 | smtp_cmd_buffer = (uschar *)malloc(2*smtp_cmd_buffer_size + 2); |
3ee512ff | 1371 | if (smtp_cmd_buffer == NULL) |
059ec3d9 PH |
1372 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, |
1373 | "malloc() failed for SMTP command buffer"); | |
ca86f471 | 1374 | smtp_data_buffer = smtp_cmd_buffer + smtp_cmd_buffer_size + 1; |
059ec3d9 PH |
1375 | |
1376 | /* For batched input, the protocol setting can be overridden from the | |
1377 | command line by a trusted caller. */ | |
1378 | ||
1379 | if (smtp_batched_input) | |
1380 | { | |
1381 | if (received_protocol == NULL) received_protocol = US"local-bsmtp"; | |
1382 | } | |
1383 | ||
1384 | /* For non-batched SMTP input, the protocol setting is forced here. It will be | |
1385 | reset later if any of EHLO/AUTH/STARTTLS are received. */ | |
1386 | ||
1387 | else | |
1388 | received_protocol = | |
1389 | protocols[pnormal] + ((sender_host_address != NULL)? pnlocal : 0); | |
1390 | ||
1391 | /* Set up the buffer for inputting using direct read() calls, and arrange to | |
1392 | call the local functions instead of the standard C ones. */ | |
1393 | ||
1394 | smtp_inbuffer = (uschar *)malloc(in_buffer_size); | |
1395 | if (smtp_inbuffer == NULL) | |
1396 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "malloc() failed for SMTP input buffer"); | |
1397 | receive_getc = smtp_getc; | |
1398 | receive_ungetc = smtp_ungetc; | |
1399 | receive_feof = smtp_feof; | |
1400 | receive_ferror = smtp_ferror; | |
58eb016e | 1401 | receive_smtp_buffered = smtp_buffered; |
059ec3d9 PH |
1402 | smtp_inptr = smtp_inend = smtp_inbuffer; |
1403 | smtp_had_eof = smtp_had_error = 0; | |
1404 | ||
1405 | /* Set up the message size limit; this may be host-specific */ | |
1406 | ||
d45b1de8 PH |
1407 | thismessage_size_limit = expand_string_integer(message_size_limit, TRUE); |
1408 | if (expand_string_message != NULL) | |
059ec3d9 PH |
1409 | { |
1410 | if (thismessage_size_limit == -1) | |
1411 | log_write(0, LOG_MAIN|LOG_PANIC, "unable to expand message_size_limit: " | |
1412 | "%s", expand_string_message); | |
1413 | else | |
1414 | log_write(0, LOG_MAIN|LOG_PANIC, "invalid message_size_limit: " | |
1415 | "%s", expand_string_message); | |
1416 | smtp_closedown(US"Temporary local problem - please try later"); | |
1417 | return FALSE; | |
1418 | } | |
1419 | ||
1420 | /* When a message is input locally via the -bs or -bS options, sender_host_ | |
1421 | unknown is set unless -oMa was used to force an IP address, in which case it | |
1422 | is checked like a real remote connection. When -bs is used from inetd, this | |
1423 | flag is not set, causing the sending host to be checked. The code that deals | |
1424 | with IP source routing (if configured) is never required for -bs or -bS and | |
1425 | the flag sender_host_notsocket is used to suppress it. | |
1426 | ||
1427 | If smtp_accept_max and smtp_accept_reserve are set, keep some connections in | |
1428 | reserve for certain hosts and/or networks. */ | |
1429 | ||
1430 | if (!sender_host_unknown) | |
1431 | { | |
1432 | int rc; | |
1433 | BOOL reserved_host = FALSE; | |
1434 | ||
1435 | /* Look up IP options (source routing info) on the socket if this is not an | |
1436 | -oMa "host", and if any are found, log them and drop the connection. | |
1437 | ||
1438 | Linux (and others now, see below) is different to everyone else, so there | |
1439 | has to be some conditional compilation here. Versions of Linux before 2.1.15 | |
1440 | used a structure whose name was "options". Somebody finally realized that | |
1441 | this name was silly, and it got changed to "ip_options". I use the | |
1442 | newer name here, but there is a fudge in the script that sets up os.h | |
1443 | to define a macro in older Linux systems. | |
1444 | ||
1445 | Sigh. Linux is a fast-moving target. Another generation of Linux uses | |
1446 | glibc 2, which has chosen ip_opts for the structure name. This is now | |
1447 | really a glibc thing rather than a Linux thing, so the condition name | |
1448 | has been changed to reflect this. It is relevant also to GNU/Hurd. | |
1449 | ||
1450 | Mac OS 10.x (Darwin) is like the later glibc versions, but without the | |
1451 | setting of the __GLIBC__ macro, so we can't detect it automatically. There's | |
1452 | a special macro defined in the os.h file. | |
1453 | ||
1454 | Some DGUX versions on older hardware appear not to support IP options at | |
1455 | all, so there is now a general macro which can be set to cut out this | |
1456 | support altogether. | |
1457 | ||
1458 | How to do this properly in IPv6 is not yet known. */ | |
1459 | ||
1460 | #if !HAVE_IPV6 && !defined(NO_IP_OPTIONS) | |
1461 | ||
1462 | #ifdef GLIBC_IP_OPTIONS | |
1463 | #if (!defined __GLIBC__) || (__GLIBC__ < 2) | |
1464 | #define OPTSTYLE 1 | |
1465 | #else | |
1466 | #define OPTSTYLE 2 | |
1467 | #endif | |
1468 | #elif defined DARWIN_IP_OPTIONS | |
1469 | #define OPTSTYLE 2 | |
1470 | #else | |
1471 | #define OPTSTYLE 3 | |
1472 | #endif | |
1473 | ||
1474 | if (!host_checking && !sender_host_notsocket) | |
1475 | { | |
1476 | #if OPTSTYLE == 1 | |
36a3b041 | 1477 | EXIM_SOCKLEN_T optlen = sizeof(struct ip_options) + MAX_IPOPTLEN; |
059ec3d9 PH |
1478 | struct ip_options *ipopt = store_get(optlen); |
1479 | #elif OPTSTYLE == 2 | |
1480 | struct ip_opts ipoptblock; | |
1481 | struct ip_opts *ipopt = &ipoptblock; | |
36a3b041 | 1482 | EXIM_SOCKLEN_T optlen = sizeof(ipoptblock); |
059ec3d9 PH |
1483 | #else |
1484 | struct ipoption ipoptblock; | |
1485 | struct ipoption *ipopt = &ipoptblock; | |
36a3b041 | 1486 | EXIM_SOCKLEN_T optlen = sizeof(ipoptblock); |
059ec3d9 PH |
1487 | #endif |
1488 | ||
1489 | /* Occasional genuine failures of getsockopt() have been seen - for | |
1490 | example, "reset by peer". Therefore, just log and give up on this | |
1491 | call, unless the error is ENOPROTOOPT. This error is given by systems | |
1492 | that have the interfaces but not the mechanism - e.g. GNU/Hurd at the time | |
1493 | of writing. So for that error, carry on - we just can't do an IP options | |
1494 | check. */ | |
1495 | ||
1496 | DEBUG(D_receive) debug_printf("checking for IP options\n"); | |
1497 | ||
1498 | if (getsockopt(fileno(smtp_out), IPPROTO_IP, IP_OPTIONS, (uschar *)(ipopt), | |
1499 | &optlen) < 0) | |
1500 | { | |
1501 | if (errno != ENOPROTOOPT) | |
1502 | { | |
1503 | log_write(0, LOG_MAIN, "getsockopt() failed from %s: %s", | |
1504 | host_and_ident(FALSE), strerror(errno)); | |
1505 | smtp_printf("451 SMTP service not available\r\n"); | |
1506 | return FALSE; | |
1507 | } | |
1508 | } | |
1509 | ||
1510 | /* Deal with any IP options that are set. On the systems I have looked at, | |
1511 | the value of MAX_IPOPTLEN has been 40, meaning that there should never be | |
1512 | more logging data than will fit in big_buffer. Nevertheless, after somebody | |
1513 | questioned this code, I've added in some paranoid checking. */ | |
1514 | ||
1515 | else if (optlen > 0) | |
1516 | { | |
1517 | uschar *p = big_buffer; | |
1518 | uschar *pend = big_buffer + big_buffer_size; | |
1519 | uschar *opt, *adptr; | |
1520 | int optcount; | |
1521 | struct in_addr addr; | |
1522 | ||
1523 | #if OPTSTYLE == 1 | |
1524 | uschar *optstart = (uschar *)(ipopt->__data); | |
1525 | #elif OPTSTYLE == 2 | |
1526 | uschar *optstart = (uschar *)(ipopt->ip_opts); | |
1527 | #else | |
1528 | uschar *optstart = (uschar *)(ipopt->ipopt_list); | |
1529 | #endif | |
1530 | ||
1531 | DEBUG(D_receive) debug_printf("IP options exist\n"); | |
1532 | ||
1533 | Ustrcpy(p, "IP options on incoming call:"); | |
1534 | p += Ustrlen(p); | |
1535 | ||
1536 | for (opt = optstart; opt != NULL && | |
1537 | opt < (uschar *)(ipopt) + optlen;) | |
1538 | { | |
1539 | switch (*opt) | |
1540 | { | |
1541 | case IPOPT_EOL: | |
1542 | opt = NULL; | |
1543 | break; | |
1544 | ||
1545 | case IPOPT_NOP: | |
1546 | opt++; | |
1547 | break; | |
1548 | ||
1549 | case IPOPT_SSRR: | |
1550 | case IPOPT_LSRR: | |
1551 | if (!string_format(p, pend-p, " %s [@%s", | |
1552 | (*opt == IPOPT_SSRR)? "SSRR" : "LSRR", | |
1553 | #if OPTSTYLE == 1 | |
1554 | inet_ntoa(*((struct in_addr *)(&(ipopt->faddr)))))) | |
1555 | #elif OPTSTYLE == 2 | |
1556 | inet_ntoa(ipopt->ip_dst))) | |
1557 | #else | |
1558 | inet_ntoa(ipopt->ipopt_dst))) | |
1559 | #endif | |
1560 | { | |
1561 | opt = NULL; | |
1562 | break; | |
1563 | } | |
1564 | ||
1565 | p += Ustrlen(p); | |
1566 | optcount = (opt[1] - 3) / sizeof(struct in_addr); | |
1567 | adptr = opt + 3; | |
1568 | while (optcount-- > 0) | |
1569 | { | |
1570 | memcpy(&addr, adptr, sizeof(addr)); | |
1571 | if (!string_format(p, pend - p - 1, "%s%s", | |
1572 | (optcount == 0)? ":" : "@", inet_ntoa(addr))) | |
1573 | { | |
1574 | opt = NULL; | |
1575 | break; | |
1576 | } | |
1577 | p += Ustrlen(p); | |
1578 | adptr += sizeof(struct in_addr); | |
1579 | } | |
1580 | *p++ = ']'; | |
1581 | opt += opt[1]; | |
1582 | break; | |
1583 | ||
1584 | default: | |
1585 | { | |
1586 | int i; | |
1587 | if (pend - p < 4 + 3*opt[1]) { opt = NULL; break; } | |
1588 | Ustrcat(p, "[ "); | |
1589 | p += 2; | |
1590 | for (i = 0; i < opt[1]; i++) | |
1591 | { | |
1592 | sprintf(CS p, "%2.2x ", opt[i]); | |
1593 | p += 3; | |
1594 | } | |
1595 | *p++ = ']'; | |
1596 | } | |
1597 | opt += opt[1]; | |
1598 | break; | |
1599 | } | |
1600 | } | |
1601 | ||
1602 | *p = 0; | |
1603 | log_write(0, LOG_MAIN, "%s", big_buffer); | |
1604 | ||
1605 | /* Refuse any call with IP options. This is what tcpwrappers 7.5 does. */ | |
1606 | ||
1607 | log_write(0, LOG_MAIN|LOG_REJECT, | |
1608 | "connection from %s refused (IP options)", host_and_ident(FALSE)); | |
1609 | ||
1610 | smtp_printf("554 SMTP service not available\r\n"); | |
1611 | return FALSE; | |
1612 | } | |
1613 | ||
1614 | /* Length of options = 0 => there are no options */ | |
1615 | ||
1616 | else DEBUG(D_receive) debug_printf("no IP options found\n"); | |
1617 | } | |
1618 | #endif /* HAVE_IPV6 && !defined(NO_IP_OPTIONS) */ | |
1619 | ||
1620 | /* Set keep-alive in socket options. The option is on by default. This | |
1621 | setting is an attempt to get rid of some hanging connections that stick in | |
1622 | read() when the remote end (usually a dialup) goes away. */ | |
1623 | ||
1624 | if (smtp_accept_keepalive && !sender_host_notsocket) | |
1625 | ip_keepalive(fileno(smtp_out), sender_host_address, FALSE); | |
1626 | ||
1627 | /* If the current host matches host_lookup, set the name by doing a | |
1628 | reverse lookup. On failure, sender_host_name will be NULL and | |
1629 | host_lookup_failed will be TRUE. This may or may not be serious - optional | |
1630 | checks later. */ | |
1631 | ||
1632 | if (verify_check_host(&host_lookup) == OK) | |
1633 | { | |
1634 | (void)host_name_lookup(); | |
1635 | host_build_sender_fullhost(); | |
1636 | } | |
1637 | ||
1638 | /* Delay this until we have the full name, if it is looked up. */ | |
1639 | ||
1640 | set_process_info("handling incoming connection from %s", | |
1641 | host_and_ident(FALSE)); | |
1642 | ||
1643 | /* Start up TLS if tls_on_connect is set. This is for supporting the legacy | |
1644 | smtps port for use with older style SSL MTAs. */ | |
1645 | ||
1646 | #ifdef SUPPORT_TLS | |
83da1223 PH |
1647 | if (tls_on_connect && |
1648 | tls_server_start(tls_require_ciphers, | |
1649 | gnutls_require_mac, gnutls_require_kx, gnutls_require_proto) != OK) | |
059ec3d9 PH |
1650 | return FALSE; |
1651 | #endif | |
1652 | ||
1653 | /* Test for explicit connection rejection */ | |
1654 | ||
1655 | if (verify_check_host(&host_reject_connection) == OK) | |
1656 | { | |
1657 | log_write(L_connection_reject, LOG_MAIN|LOG_REJECT, "refused connection " | |
1658 | "from %s (host_reject_connection)", host_and_ident(FALSE)); | |
1659 | smtp_printf("554 SMTP service not available\r\n"); | |
1660 | return FALSE; | |
1661 | } | |
1662 | ||
afb3eaaf PH |
1663 | /* Test with TCP Wrappers if so configured. There is a problem in that |
1664 | hosts_ctl() returns 0 (deny) under a number of system failure circumstances, | |
1665 | such as disks dying. In these cases, it is desirable to reject with a 4xx | |
1666 | error instead of a 5xx error. There isn't a "right" way to detect such | |
1667 | problems. The following kludge is used: errno is zeroed before calling | |
1668 | hosts_ctl(). If the result is "reject", a 5xx error is given only if the | |
1669 | value of errno is 0 or ENOENT (which happens if /etc/hosts.{allow,deny} does | |
1670 | not exist). */ | |
059ec3d9 PH |
1671 | |
1672 | #ifdef USE_TCP_WRAPPERS | |
afb3eaaf | 1673 | errno = 0; |
059ec3d9 PH |
1674 | if (!hosts_ctl("exim", |
1675 | (sender_host_name == NULL)? STRING_UNKNOWN : CS sender_host_name, | |
1676 | (sender_host_address == NULL)? STRING_UNKNOWN : CS sender_host_address, | |
1677 | (sender_ident == NULL)? STRING_UNKNOWN : CS sender_ident)) | |
1678 | { | |
afb3eaaf PH |
1679 | if (errno == 0 || errno == ENOENT) |
1680 | { | |
1681 | HDEBUG(D_receive) debug_printf("tcp wrappers rejection\n"); | |
1682 | log_write(L_connection_reject, | |
1683 | LOG_MAIN|LOG_REJECT, "refused connection from %s " | |
1684 | "(tcp wrappers)", host_and_ident(FALSE)); | |
1685 | smtp_printf("554 SMTP service not available\r\n"); | |
1686 | } | |
1687 | else | |
1688 | { | |
1689 | int save_errno = errno; | |
1690 | HDEBUG(D_receive) debug_printf("tcp wrappers rejected with unexpected " | |
1691 | "errno value %d\n", save_errno); | |
1692 | log_write(L_connection_reject, | |
1693 | LOG_MAIN|LOG_REJECT, "temporarily refused connection from %s " | |
1694 | "(tcp wrappers errno=%d)", host_and_ident(FALSE), save_errno); | |
1695 | smtp_printf("451 Temporary local problem - please try later\r\n"); | |
1696 | } | |
059ec3d9 PH |
1697 | return FALSE; |
1698 | } | |
1699 | #endif | |
1700 | ||
b01dd148 PH |
1701 | /* Check for reserved slots. The value of smtp_accept_count has already been |
1702 | incremented to include this process. */ | |
059ec3d9 PH |
1703 | |
1704 | if (smtp_accept_max > 0 && | |
b01dd148 | 1705 | smtp_accept_count > smtp_accept_max - smtp_accept_reserve) |
059ec3d9 PH |
1706 | { |
1707 | if ((rc = verify_check_host(&smtp_reserve_hosts)) != OK) | |
1708 | { | |
1709 | log_write(L_connection_reject, | |
1710 | LOG_MAIN, "temporarily refused connection from %s: not in " | |
1711 | "reserve list: connected=%d max=%d reserve=%d%s", | |
b01dd148 | 1712 | host_and_ident(FALSE), smtp_accept_count - 1, smtp_accept_max, |
059ec3d9 PH |
1713 | smtp_accept_reserve, (rc == DEFER)? " (lookup deferred)" : ""); |
1714 | smtp_printf("421 %s: Too many concurrent SMTP connections; " | |
1715 | "please try again later\r\n", smtp_active_hostname); | |
1716 | return FALSE; | |
1717 | } | |
1718 | reserved_host = TRUE; | |
1719 | } | |
1720 | ||
1721 | /* If a load level above which only messages from reserved hosts are | |
1722 | accepted is set, check the load. For incoming calls via the daemon, the | |
1723 | check is done in the superior process if there are no reserved hosts, to | |
1724 | save a fork. In all cases, the load average will already be available | |
1725 | in a global variable at this point. */ | |
1726 | ||
1727 | if (smtp_load_reserve >= 0 && | |
1728 | load_average > smtp_load_reserve && | |
1729 | !reserved_host && | |
1730 | verify_check_host(&smtp_reserve_hosts) != OK) | |
1731 | { | |
1732 | log_write(L_connection_reject, | |
1733 | LOG_MAIN, "temporarily refused connection from %s: not in " | |
1734 | "reserve list and load average = %.2f", host_and_ident(FALSE), | |
1735 | (double)load_average/1000.0); | |
1736 | smtp_printf("421 %s: Too much load; please try again later\r\n", | |
1737 | smtp_active_hostname); | |
1738 | return FALSE; | |
1739 | } | |
1740 | ||
1741 | /* Determine whether unqualified senders or recipients are permitted | |
1742 | for this host. Unfortunately, we have to do this every time, in order to | |
1743 | set the flags so that they can be inspected when considering qualifying | |
1744 | addresses in the headers. For a site that permits no qualification, this | |
1745 | won't take long, however. */ | |
1746 | ||
1747 | allow_unqualified_sender = | |
1748 | verify_check_host(&sender_unqualified_hosts) == OK; | |
1749 | ||
1750 | allow_unqualified_recipient = | |
1751 | verify_check_host(&recipient_unqualified_hosts) == OK; | |
1752 | ||
1753 | /* Determine whether HELO/EHLO is required for this host. The requirement | |
1754 | can be hard or soft. */ | |
1755 | ||
1756 | helo_required = verify_check_host(&helo_verify_hosts) == OK; | |
1757 | if (!helo_required) | |
1758 | helo_verify = verify_check_host(&helo_try_verify_hosts) == OK; | |
1759 | ||
1760 | /* Determine whether this hosts is permitted to send syntactic junk | |
1761 | after a HELO or EHLO command. */ | |
1762 | ||
1763 | helo_accept_junk = verify_check_host(&helo_accept_junk_hosts) == OK; | |
1764 | } | |
1765 | ||
1766 | /* For batch SMTP input we are now done. */ | |
1767 | ||
1768 | if (smtp_batched_input) return TRUE; | |
1769 | ||
1770 | /* Run the ACL if it exists */ | |
1771 | ||
4e88a19f | 1772 | user_msg = NULL; |
059ec3d9 PH |
1773 | if (acl_smtp_connect != NULL) |
1774 | { | |
1775 | int rc; | |
64ffc24f | 1776 | rc = acl_check(ACL_WHERE_CONNECT, NULL, acl_smtp_connect, &user_msg, |
059ec3d9 PH |
1777 | &log_msg); |
1778 | if (rc != OK) | |
1779 | { | |
1780 | (void)smtp_handle_acl_fail(ACL_WHERE_CONNECT, rc, user_msg, log_msg); | |
1781 | return FALSE; | |
1782 | } | |
1783 | } | |
1784 | ||
1785 | /* Output the initial message for a two-way SMTP connection. It may contain | |
1786 | newlines, which then cause a multi-line response to be given. */ | |
1787 | ||
4e88a19f PH |
1788 | code = US"220"; /* Default status code */ |
1789 | esc = US""; /* Default extended status code */ | |
1790 | esclen = 0; /* Length of esc */ | |
1791 | ||
1792 | if (user_msg == NULL) | |
1793 | { | |
1794 | s = expand_string(smtp_banner); | |
1795 | if (s == NULL) | |
1796 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" (smtp_banner) " | |
1797 | "failed: %s", smtp_banner, expand_string_message); | |
1798 | } | |
1799 | else | |
1800 | { | |
1801 | int codelen = 3; | |
1802 | s = user_msg; | |
1803 | smtp_message_code(&code, &codelen, &s, NULL); | |
d6a96edc | 1804 | if (codelen > 4) |
4e88a19f PH |
1805 | { |
1806 | esc = code + 4; | |
1807 | esclen = codelen - 4; | |
1808 | } | |
1809 | } | |
059ec3d9 PH |
1810 | |
1811 | /* Remove any terminating newlines; might as well remove trailing space too */ | |
1812 | ||
1813 | p = s + Ustrlen(s); | |
1814 | while (p > s && isspace(p[-1])) p--; | |
1815 | *p = 0; | |
1816 | ||
1817 | /* It seems that CC:Mail is braindead, and assumes that the greeting message | |
1818 | is all contained in a single IP packet. The original code wrote out the | |
1819 | greeting using several calls to fprint/fputc, and on busy servers this could | |
1820 | cause it to be split over more than one packet - which caused CC:Mail to fall | |
1821 | over when it got the second part of the greeting after sending its first | |
1822 | command. Sigh. To try to avoid this, build the complete greeting message | |
1823 | first, and output it in one fell swoop. This gives a better chance of it | |
1824 | ending up as a single packet. */ | |
1825 | ||
1826 | ss = store_get(size); | |
1827 | ptr = 0; | |
1828 | ||
1829 | p = s; | |
1830 | do /* At least once, in case we have an empty string */ | |
1831 | { | |
1832 | int len; | |
1833 | uschar *linebreak = Ustrchr(p, '\n'); | |
4e88a19f | 1834 | ss = string_cat(ss, &size, &ptr, code, 3); |
059ec3d9 PH |
1835 | if (linebreak == NULL) |
1836 | { | |
1837 | len = Ustrlen(p); | |
4e88a19f | 1838 | ss = string_cat(ss, &size, &ptr, US" ", 1); |
059ec3d9 PH |
1839 | } |
1840 | else | |
1841 | { | |
1842 | len = linebreak - p; | |
4e88a19f | 1843 | ss = string_cat(ss, &size, &ptr, US"-", 1); |
059ec3d9 | 1844 | } |
4e88a19f | 1845 | ss = string_cat(ss, &size, &ptr, esc, esclen); |
059ec3d9 PH |
1846 | ss = string_cat(ss, &size, &ptr, p, len); |
1847 | ss = string_cat(ss, &size, &ptr, US"\r\n", 2); | |
1848 | p += len; | |
1849 | if (linebreak != NULL) p++; | |
1850 | } | |
1851 | while (*p != 0); | |
1852 | ||
1853 | ss[ptr] = 0; /* string_cat leaves room for this */ | |
1854 | ||
1855 | /* Before we write the banner, check that there is no input pending, unless | |
1856 | this synchronisation check is disabled. */ | |
1857 | ||
a14e5636 | 1858 | if (!check_sync()) |
059ec3d9 | 1859 | { |
a14e5636 PH |
1860 | log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol " |
1861 | "synchronization error (input sent without waiting for greeting): " | |
1862 | "rejected connection from %s input=\"%s\"", host_and_ident(TRUE), | |
1863 | string_printing(smtp_inptr)); | |
1864 | smtp_printf("554 SMTP synchronization error\r\n"); | |
1865 | return FALSE; | |
059ec3d9 PH |
1866 | } |
1867 | ||
1868 | /* Now output the banner */ | |
1869 | ||
1870 | smtp_printf("%s", ss); | |
1871 | return TRUE; | |
1872 | } | |
1873 | ||
1874 | ||
1875 | ||
1876 | ||
1877 | ||
1878 | /************************************************* | |
1879 | * Handle SMTP syntax and protocol errors * | |
1880 | *************************************************/ | |
1881 | ||
1882 | /* Write to the log for SMTP syntax errors in incoming commands, if configured | |
1883 | to do so. Then transmit the error response. The return value depends on the | |
1884 | number of syntax and protocol errors in this SMTP session. | |
1885 | ||
1886 | Arguments: | |
1887 | type error type, given as a log flag bit | |
1888 | code response code; <= 0 means don't send a response | |
1889 | data data to reflect in the response (can be NULL) | |
1890 | errmess the error message | |
1891 | ||
1892 | Returns: -1 limit of syntax/protocol errors NOT exceeded | |
1893 | +1 limit of syntax/protocol errors IS exceeded | |
1894 | ||
1895 | These values fit in with the values of the "done" variable in the main | |
1896 | processing loop in smtp_setup_msg(). */ | |
1897 | ||
1898 | static int | |
1899 | synprot_error(int type, int code, uschar *data, uschar *errmess) | |
1900 | { | |
1901 | int yield = -1; | |
1902 | ||
1903 | log_write(type, LOG_MAIN, "SMTP %s error in \"%s\" %s %s", | |
1904 | (type == L_smtp_syntax_error)? "syntax" : "protocol", | |
3ee512ff | 1905 | string_printing(smtp_cmd_buffer), host_and_ident(TRUE), errmess); |
059ec3d9 PH |
1906 | |
1907 | if (++synprot_error_count > smtp_max_synprot_errors) | |
1908 | { | |
1909 | yield = 1; | |
1910 | log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many " | |
1911 | "syntax or protocol errors (last command was \"%s\")", | |
3ee512ff | 1912 | host_and_ident(FALSE), smtp_cmd_buffer); |
059ec3d9 PH |
1913 | } |
1914 | ||
1915 | if (code > 0) | |
1916 | { | |
1917 | smtp_printf("%d%c%s%s%s\r\n", code, (yield == 1)? '-' : ' ', | |
1918 | (data == NULL)? US"" : data, (data == NULL)? US"" : US": ", errmess); | |
1919 | if (yield == 1) | |
1920 | smtp_printf("%d Too many syntax or protocol errors\r\n", code); | |
1921 | } | |
1922 | ||
1923 | return yield; | |
1924 | } | |
1925 | ||
1926 | ||
1927 | ||
1928 | ||
1929 | /************************************************* | |
1930 | * Log incomplete transactions * | |
1931 | *************************************************/ | |
1932 | ||
1933 | /* This function is called after a transaction has been aborted by RSET, QUIT, | |
1934 | connection drops or other errors. It logs the envelope information received | |
1935 | so far in order to preserve address verification attempts. | |
1936 | ||
1937 | Argument: string to indicate what aborted the transaction | |
1938 | Returns: nothing | |
1939 | */ | |
1940 | ||
1941 | static void | |
1942 | incomplete_transaction_log(uschar *what) | |
1943 | { | |
1944 | if (sender_address == NULL || /* No transaction in progress */ | |
1945 | (log_write_selector & L_smtp_incomplete_transaction) == 0 /* Not logging */ | |
1946 | ) return; | |
1947 | ||
1948 | /* Build list of recipients for logging */ | |
1949 | ||
1950 | if (recipients_count > 0) | |
1951 | { | |
1952 | int i; | |
1953 | raw_recipients = store_get(recipients_count * sizeof(uschar *)); | |
1954 | for (i = 0; i < recipients_count; i++) | |
1955 | raw_recipients[i] = recipients_list[i].address; | |
1956 | raw_recipients_count = recipients_count; | |
1957 | } | |
1958 | ||
1959 | log_write(L_smtp_incomplete_transaction, LOG_MAIN|LOG_SENDER|LOG_RECIPIENTS, | |
1960 | "%s incomplete transaction (%s)", host_and_ident(TRUE), what); | |
1961 | } | |
1962 | ||
1963 | ||
1964 | ||
1965 | ||
1966 | /************************************************* | |
1967 | * Send SMTP response, possibly multiline * | |
1968 | *************************************************/ | |
1969 | ||
1970 | /* There are, it seems, broken clients out there that cannot handle multiline | |
1971 | responses. If no_multiline_responses is TRUE (it can be set from an ACL), we | |
1972 | output nothing for non-final calls, and only the first line for anything else. | |
1973 | ||
1974 | Arguments: | |
a5bd321b | 1975 | code SMTP code, may involve extended status codes |
d6a96edc | 1976 | codelen length of smtp code; if > 4 there's an ESC |
059ec3d9 PH |
1977 | final FALSE if the last line isn't the final line |
1978 | msg message text, possibly containing newlines | |
1979 | ||
1980 | Returns: nothing | |
1981 | */ | |
1982 | ||
1983 | void | |
a5bd321b | 1984 | smtp_respond(uschar* code, int codelen, BOOL final, uschar *msg) |
059ec3d9 | 1985 | { |
a5bd321b PH |
1986 | int esclen = 0; |
1987 | uschar *esc = US""; | |
1988 | ||
059ec3d9 PH |
1989 | if (!final && no_multiline_responses) return; |
1990 | ||
d6a96edc | 1991 | if (codelen > 4) |
a5bd321b PH |
1992 | { |
1993 | esc = code + 4; | |
1994 | esclen = codelen - 4; | |
1995 | } | |
1996 | ||
2679d413 PH |
1997 | /* If this is the first output for a (non-batch) RCPT command, see if all RCPTs |
1998 | have had the same. Note: this code is also present in smtp_printf(). It would | |
1999 | be tidier to have it only in one place, but when it was added, it was easier to | |
2000 | do it that way, so as not to have to mess with the code for the RCPT command, | |
2001 | which sometimes uses smtp_printf() and sometimes smtp_respond(). */ | |
2002 | ||
2003 | if (rcpt_in_progress) | |
2004 | { | |
2005 | if (rcpt_smtp_response == NULL) | |
2006 | rcpt_smtp_response = string_copy(msg); | |
2007 | else if (rcpt_smtp_response_same && | |
2008 | Ustrcmp(rcpt_smtp_response, msg) != 0) | |
2009 | rcpt_smtp_response_same = FALSE; | |
2010 | rcpt_in_progress = FALSE; | |
2011 | } | |
2012 | ||
2013 | /* Not output the message, splitting it up into multiple lines if necessary. */ | |
2014 | ||
059ec3d9 PH |
2015 | for (;;) |
2016 | { | |
2017 | uschar *nl = Ustrchr(msg, '\n'); | |
2018 | if (nl == NULL) | |
2019 | { | |
a5bd321b | 2020 | smtp_printf("%.3s%c%.*s%s\r\n", code, final? ' ':'-', esclen, esc, msg); |
059ec3d9 PH |
2021 | return; |
2022 | } | |
2023 | else if (nl[1] == 0 || no_multiline_responses) | |
2024 | { | |
a5bd321b PH |
2025 | smtp_printf("%.3s%c%.*s%.*s\r\n", code, final? ' ':'-', esclen, esc, |
2026 | (int)(nl - msg), msg); | |
059ec3d9 PH |
2027 | return; |
2028 | } | |
2029 | else | |
2030 | { | |
a5bd321b | 2031 | smtp_printf("%.3s-%.*s%.*s\r\n", code, esclen, esc, (int)(nl - msg), msg); |
059ec3d9 PH |
2032 | msg = nl + 1; |
2033 | while (isspace(*msg)) msg++; | |
2034 | } | |
2035 | } | |
2036 | } | |
2037 | ||
2038 | ||
2039 | ||
2040 | ||
4e88a19f PH |
2041 | /************************************************* |
2042 | * Parse user SMTP message * | |
2043 | *************************************************/ | |
2044 | ||
2045 | /* This function allows for user messages overriding the response code details | |
2046 | by providing a suitable response code string at the start of the message | |
2047 | user_msg. Check the message for starting with a response code and optionally an | |
2048 | extended status code. If found, check that the first digit is valid, and if so, | |
2049 | change the code pointer and length to use the replacement. An invalid code | |
2050 | causes a panic log; in this case, if the log messages is the same as the user | |
2051 | message, we must also adjust the value of the log message to show the code that | |
2052 | is actually going to be used (the original one). | |
2053 | ||
2054 | This function is global because it is called from receive.c as well as within | |
2055 | this module. | |
2056 | ||
d6a96edc PH |
2057 | Note that the code length returned includes the terminating whitespace |
2058 | character, which is always included in the regex match. | |
2059 | ||
4e88a19f PH |
2060 | Arguments: |
2061 | code SMTP code, may involve extended status codes | |
d6a96edc | 2062 | codelen length of smtp code; if > 4 there's an ESC |
4e88a19f PH |
2063 | msg message text |
2064 | log_msg optional log message, to be adjusted with the new SMTP code | |
2065 | ||
2066 | Returns: nothing | |
2067 | */ | |
2068 | ||
2069 | void | |
2070 | smtp_message_code(uschar **code, int *codelen, uschar **msg, uschar **log_msg) | |
2071 | { | |
2072 | int n; | |
2073 | int ovector[3]; | |
2074 | ||
2075 | if (msg == NULL || *msg == NULL) return; | |
2076 | ||
2077 | n = pcre_exec(regex_smtp_code, NULL, CS *msg, Ustrlen(*msg), 0, | |
2078 | PCRE_EOPT, ovector, sizeof(ovector)/sizeof(int)); | |
2079 | if (n < 0) return; | |
2080 | ||
2081 | if ((*msg)[0] != (*code)[0]) | |
2082 | { | |
2083 | log_write(0, LOG_MAIN|LOG_PANIC, "configured error code starts with " | |
2084 | "incorrect digit (expected %c) in \"%s\"", (*code)[0], *msg); | |
2085 | if (log_msg != NULL && *log_msg == *msg) | |
2086 | *log_msg = string_sprintf("%s %s", *code, *log_msg + ovector[1]); | |
2087 | } | |
2088 | else | |
2089 | { | |
2090 | *code = *msg; | |
2091 | *codelen = ovector[1]; /* Includes final space */ | |
2092 | } | |
2093 | *msg += ovector[1]; /* Chop the code off the message */ | |
2094 | return; | |
2095 | } | |
2096 | ||
2097 | ||
2098 | ||
2099 | ||
059ec3d9 PH |
2100 | /************************************************* |
2101 | * Handle an ACL failure * | |
2102 | *************************************************/ | |
2103 | ||
2104 | /* This function is called when acl_check() fails. As well as calls from within | |
2105 | this module, it is called from receive.c for an ACL after DATA. It sorts out | |
2106 | logging the incident, and sets up the error response. A message containing | |
2107 | newlines is turned into a multiline SMTP response, but for logging, only the | |
2108 | first line is used. | |
2109 | ||
a5bd321b PH |
2110 | There's a table of default permanent failure response codes to use in |
2111 | globals.c, along with the table of names. VFRY is special. Despite RFC1123 it | |
2112 | defaults disabled in Exim. However, discussion in connection with RFC 821bis | |
2113 | (aka RFC 2821) has concluded that the response should be 252 in the disabled | |
2114 | state, because there are broken clients that try VRFY before RCPT. A 5xx | |
2115 | response should be given only when the address is positively known to be | |
2116 | undeliverable. Sigh. Also, for ETRN, 458 is given on refusal, and for AUTH, | |
2117 | 503. | |
2118 | ||
2119 | From Exim 4.63, it is possible to override the response code details by | |
2120 | providing a suitable response code string at the start of the message provided | |
2121 | in user_msg. The code's first digit is checked for validity. | |
059ec3d9 PH |
2122 | |
2123 | Arguments: | |
2124 | where where the ACL was called from | |
2125 | rc the failure code | |
2126 | user_msg a message that can be included in an SMTP response | |
2127 | log_msg a message for logging | |
2128 | ||
2129 | Returns: 0 in most cases | |
2130 | 2 if the failure code was FAIL_DROP, in which case the | |
2131 | SMTP connection should be dropped (this value fits with the | |
2132 | "done" variable in smtp_setup_msg() below) | |
2133 | */ | |
2134 | ||
2135 | int | |
2136 | smtp_handle_acl_fail(int where, int rc, uschar *user_msg, uschar *log_msg) | |
2137 | { | |
059ec3d9 | 2138 | BOOL drop = rc == FAIL_DROP; |
a5bd321b | 2139 | int codelen = 3; |
a5bd321b | 2140 | uschar *smtp_code; |
059ec3d9 PH |
2141 | uschar *lognl; |
2142 | uschar *sender_info = US""; | |
64ffc24f | 2143 | uschar *what = |
8523533c | 2144 | #ifdef WITH_CONTENT_SCAN |
64ffc24f | 2145 | (where == ACL_WHERE_MIME)? US"during MIME ACL checks" : |
8e669ac1 | 2146 | #endif |
64ffc24f PH |
2147 | (where == ACL_WHERE_PREDATA)? US"DATA" : |
2148 | (where == ACL_WHERE_DATA)? US"after DATA" : | |
ca86f471 | 2149 | (smtp_cmd_data == NULL)? |
64ffc24f | 2150 | string_sprintf("%s in \"connect\" ACL", acl_wherenames[where]) : |
ca86f471 | 2151 | string_sprintf("%s %s", acl_wherenames[where], smtp_cmd_data); |
059ec3d9 PH |
2152 | |
2153 | if (drop) rc = FAIL; | |
2154 | ||
4e88a19f | 2155 | /* Set the default SMTP code, and allow a user message to change it. */ |
a5bd321b PH |
2156 | |
2157 | smtp_code = (rc != FAIL)? US"451" : acl_wherecodes[where]; | |
4e88a19f | 2158 | smtp_message_code(&smtp_code, &codelen, &user_msg, &log_msg); |
a5bd321b | 2159 | |
059ec3d9 PH |
2160 | /* We used to have sender_address here; however, there was a bug that was not |
2161 | updating sender_address after a rewrite during a verify. When this bug was | |
2162 | fixed, sender_address at this point became the rewritten address. I'm not sure | |
2163 | this is what should be logged, so I've changed to logging the unrewritten | |
2164 | address to retain backward compatibility. */ | |
2165 | ||
8523533c | 2166 | #ifndef WITH_CONTENT_SCAN |
059ec3d9 | 2167 | if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA) |
8523533c TK |
2168 | #else |
2169 | if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA || where == ACL_WHERE_MIME) | |
2170 | #endif | |
059ec3d9 PH |
2171 | { |
2172 | sender_info = string_sprintf("F=<%s> ", (sender_address_unrewritten != NULL)? | |
2173 | sender_address_unrewritten : sender_address); | |
2174 | } | |
2175 | ||
2176 | /* If there's been a sender verification failure with a specific message, and | |
2177 | we have not sent a response about it yet, do so now, as a preliminary line for | |
278c6e6c PH |
2178 | failures, but not defers. However, always log it for defer, and log it for fail |
2179 | unless the sender_verify_fail log selector has been turned off. */ | |
059ec3d9 PH |
2180 | |
2181 | if (sender_verified_failed != NULL && | |
2182 | !testflag(sender_verified_failed, af_sverify_told)) | |
2183 | { | |
2679d413 PH |
2184 | BOOL save_rcpt_in_progress = rcpt_in_progress; |
2185 | rcpt_in_progress = FALSE; /* So as not to treat these as the error */ | |
2186 | ||
059ec3d9 PH |
2187 | setflag(sender_verified_failed, af_sverify_told); |
2188 | ||
278c6e6c PH |
2189 | if (rc != FAIL || (log_extra_selector & LX_sender_verify_fail) != 0) |
2190 | log_write(0, LOG_MAIN|LOG_REJECT, "%s sender verify %s for <%s>%s", | |
2191 | host_and_ident(TRUE), | |
2192 | ((sender_verified_failed->special_action & 255) == DEFER)? "defer":"fail", | |
2193 | sender_verified_failed->address, | |
2194 | (sender_verified_failed->message == NULL)? US"" : | |
2195 | string_sprintf(": %s", sender_verified_failed->message)); | |
059ec3d9 PH |
2196 | |
2197 | if (rc == FAIL && sender_verified_failed->user_message != NULL) | |
a5bd321b | 2198 | smtp_respond(smtp_code, codelen, FALSE, string_sprintf( |
059ec3d9 PH |
2199 | testflag(sender_verified_failed, af_verify_pmfail)? |
2200 | "Postmaster verification failed while checking <%s>\n%s\n" | |
2201 | "Several RFCs state that you are required to have a postmaster\n" | |
2202 | "mailbox for each mail domain. This host does not accept mail\n" | |
2203 | "from domains whose servers reject the postmaster address." | |
2204 | : | |
2205 | testflag(sender_verified_failed, af_verify_nsfail)? | |
2206 | "Callback setup failed while verifying <%s>\n%s\n" | |
2207 | "The initial connection, or a HELO or MAIL FROM:<> command was\n" | |
2208 | "rejected. Refusing MAIL FROM:<> does not help fight spam, disregards\n" | |
2209 | "RFC requirements, and stops you from receiving standard bounce\n" | |
2210 | "messages. This host does not accept mail from domains whose servers\n" | |
2211 | "refuse bounces." | |
2212 | : | |
2213 | "Verification failed for <%s>\n%s", | |
2214 | sender_verified_failed->address, | |
2215 | sender_verified_failed->user_message)); | |
2679d413 PH |
2216 | |
2217 | rcpt_in_progress = save_rcpt_in_progress; | |
059ec3d9 PH |
2218 | } |
2219 | ||
2220 | /* Sort out text for logging */ | |
2221 | ||
2222 | log_msg = (log_msg == NULL)? US"" : string_sprintf(": %s", log_msg); | |
2223 | lognl = Ustrchr(log_msg, '\n'); | |
2224 | if (lognl != NULL) *lognl = 0; | |
2225 | ||
2226 | /* Send permanent failure response to the command, but the code used isn't | |
2227 | always a 5xx one - see comments at the start of this function. If the original | |
2228 | rc was FAIL_DROP we drop the connection and yield 2. */ | |
2229 | ||
a5bd321b | 2230 | if (rc == FAIL) smtp_respond(smtp_code, codelen, TRUE, (user_msg == NULL)? |
059ec3d9 PH |
2231 | US"Administrative prohibition" : user_msg); |
2232 | ||
2233 | /* Send temporary failure response to the command. Don't give any details, | |
2234 | unless acl_temp_details is set. This is TRUE for a callout defer, a "defer" | |
2235 | verb, and for a header verify when smtp_return_error_details is set. | |
2236 | ||
2237 | This conditional logic is all somewhat of a mess because of the odd | |
2238 | interactions between temp_details and return_error_details. One day it should | |
2239 | be re-implemented in a tidier fashion. */ | |
2240 | ||
2241 | else | |
2242 | { | |
2243 | if (acl_temp_details && user_msg != NULL) | |
2244 | { | |
2245 | if (smtp_return_error_details && | |
2246 | sender_verified_failed != NULL && | |
2247 | sender_verified_failed->message != NULL) | |
2248 | { | |
a5bd321b | 2249 | smtp_respond(smtp_code, codelen, FALSE, sender_verified_failed->message); |
059ec3d9 | 2250 | } |
a5bd321b | 2251 | smtp_respond(smtp_code, codelen, TRUE, user_msg); |
059ec3d9 PH |
2252 | } |
2253 | else | |
a5bd321b PH |
2254 | smtp_respond(smtp_code, codelen, TRUE, |
2255 | US"Temporary local problem - please try later"); | |
059ec3d9 PH |
2256 | } |
2257 | ||
6ea85e9a PH |
2258 | /* Log the incident to the logs that are specified by log_reject_target |
2259 | (default main, reject). This can be empty to suppress logging of rejections. If | |
2260 | the connection is not forcibly to be dropped, return 0. Otherwise, log why it | |
2261 | is closing if required and return 2. */ | |
059ec3d9 | 2262 | |
6ea85e9a PH |
2263 | if (log_reject_target != 0) |
2264 | log_write(0, log_reject_target, "%s %s%srejected %s%s", | |
2265 | host_and_ident(TRUE), | |
2266 | sender_info, (rc == FAIL)? US"" : US"temporarily ", what, log_msg); | |
059ec3d9 PH |
2267 | |
2268 | if (!drop) return 0; | |
2269 | ||
2270 | log_write(L_smtp_connection, LOG_MAIN, "%s closed by DROP in ACL", | |
2271 | smtp_get_connection_info()); | |
8f128379 PH |
2272 | |
2273 | /* Run the not-quit ACL, but without any custom messages. This should not be a | |
2274 | problem, because we get here only if some other ACL has issued "drop", and | |
2275 | in that case, *its* custom messages will have been used above. */ | |
2276 | ||
2277 | smtp_notquit_exit(US"acl-drop", NULL, NULL); | |
059ec3d9 PH |
2278 | return 2; |
2279 | } | |
2280 | ||
2281 | ||
2282 | ||
2283 | ||
8f128379 PH |
2284 | /************************************************* |
2285 | * Handle SMTP exit when QUIT is not given * | |
2286 | *************************************************/ | |
2287 | ||
2288 | /* This function provides a logging/statistics hook for when an SMTP connection | |
2289 | is dropped on the floor or the other end goes away. It's a global function | |
2290 | because it's called from receive.c as well as this module. As well as running | |
2291 | the NOTQUIT ACL, if there is one, this function also outputs a final SMTP | |
2292 | response, either with a custom message from the ACL, or using a default. There | |
2293 | is one case, however, when no message is output - after "drop". In that case, | |
2294 | the ACL that obeyed "drop" has already supplied the custom message, and NULL is | |
2295 | passed to this function. | |
2296 | ||
2297 | In case things go wrong while processing this function, causing an error that | |
2298 | may re-enter this funtion, there is a recursion check. | |
2299 | ||
2300 | Arguments: | |
2301 | reason What $smtp_notquit_reason will be set to in the ACL; | |
2302 | if NULL, the ACL is not run | |
2303 | code The error code to return as part of the response | |
2304 | defaultrespond The default message if there's no user_msg | |
2305 | ||
2306 | Returns: Nothing | |
2307 | */ | |
2308 | ||
2309 | void | |
2310 | smtp_notquit_exit(uschar *reason, uschar *code, uschar *defaultrespond, ...) | |
2311 | { | |
2312 | int rc; | |
2313 | uschar *user_msg = NULL; | |
2314 | uschar *log_msg = NULL; | |
2315 | ||
2316 | /* Check for recursive acll */ | |
2317 | ||
2318 | if (smtp_exit_function_called) | |
2319 | { | |
2320 | log_write(0, LOG_PANIC, "smtp_notquit_exit() called more than once (%s)", | |
2321 | reason); | |
2322 | return; | |
2323 | } | |
2324 | smtp_exit_function_called = TRUE; | |
2325 | ||
2326 | /* Call the not-QUIT ACL, if there is one, unless no reason is given. */ | |
2327 | ||
2328 | if (acl_smtp_notquit != NULL && reason != NULL) | |
2329 | { | |
2330 | smtp_notquit_reason = reason; | |
2331 | rc = acl_check(ACL_WHERE_NOTQUIT, NULL, acl_smtp_notquit, &user_msg, | |
2332 | &log_msg); | |
2333 | if (rc == ERROR) | |
2334 | log_write(0, LOG_MAIN|LOG_PANIC, "ACL for not-QUIT returned ERROR: %s", | |
2335 | log_msg); | |
2336 | } | |
2337 | ||
2338 | /* Write an SMTP response if we are expected to give one. As the default | |
2339 | responses are all internal, they should always fit in the buffer, but code a | |
2340 | warning, just in case. Note that string_vformat() still leaves a complete | |
2341 | string, even if it is incomplete. */ | |
2342 | ||
2343 | if (code != NULL && defaultrespond != NULL) | |
2344 | { | |
2345 | if (user_msg == NULL) | |
2346 | { | |
2347 | uschar buffer[128]; | |
2348 | va_list ap; | |
2349 | va_start(ap, defaultrespond); | |
2350 | if (!string_vformat(buffer, sizeof(buffer), CS defaultrespond, ap)) | |
2351 | log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_notquit_exit()"); | |
2352 | smtp_printf("%s %s\r\n", code, buffer); | |
2353 | va_end(ap); | |
2354 | } | |
2355 | else | |
2356 | smtp_respond(code, 3, TRUE, user_msg); | |
2357 | mac_smtp_fflush(); | |
2358 | } | |
2359 | } | |
2360 | ||
2361 | ||
2362 | ||
2363 | ||
d7b47fd0 PH |
2364 | /************************************************* |
2365 | * Verify HELO argument * | |
2366 | *************************************************/ | |
2367 | ||
2368 | /* This function is called if helo_verify_hosts or helo_try_verify_hosts is | |
2369 | matched. It is also called from ACL processing if verify = helo is used and | |
2370 | verification was not previously tried (i.e. helo_try_verify_hosts was not | |
2371 | matched). The result of its processing is to set helo_verified and | |
2372 | helo_verify_failed. These variables should both be FALSE for this function to | |
2373 | be called. | |
2374 | ||
2375 | Note that EHLO/HELO is legitimately allowed to quote an address literal. Allow | |
2376 | for IPv6 ::ffff: literals. | |
2377 | ||
2378 | Argument: none | |
2379 | Returns: TRUE if testing was completed; | |
2380 | FALSE on a temporary failure | |
2381 | */ | |
2382 | ||
2383 | BOOL | |
2384 | smtp_verify_helo(void) | |
2385 | { | |
2386 | BOOL yield = TRUE; | |
2387 | ||
2388 | HDEBUG(D_receive) debug_printf("verifying EHLO/HELO argument \"%s\"\n", | |
2389 | sender_helo_name); | |
2390 | ||
2391 | if (sender_helo_name == NULL) | |
2392 | { | |
2393 | HDEBUG(D_receive) debug_printf("no EHLO/HELO command was issued\n"); | |
2394 | } | |
2395 | ||
d1d5595c PH |
2396 | /* Deal with the case of -bs without an IP address */ |
2397 | ||
2398 | else if (sender_host_address == NULL) | |
2399 | { | |
2400 | HDEBUG(D_receive) debug_printf("no client IP address: assume success\n"); | |
2401 | helo_verified = TRUE; | |
2402 | } | |
2403 | ||
2404 | /* Deal with the more common case when there is a sending IP address */ | |
2405 | ||
d7b47fd0 PH |
2406 | else if (sender_helo_name[0] == '[') |
2407 | { | |
2408 | helo_verified = Ustrncmp(sender_helo_name+1, sender_host_address, | |
2409 | Ustrlen(sender_host_address)) == 0; | |
2410 | ||
2411 | #if HAVE_IPV6 | |
2412 | if (!helo_verified) | |
2413 | { | |
2414 | if (strncmpic(sender_host_address, US"::ffff:", 7) == 0) | |
2415 | helo_verified = Ustrncmp(sender_helo_name + 1, | |
2416 | sender_host_address + 7, Ustrlen(sender_host_address) - 7) == 0; | |
2417 | } | |
2418 | #endif | |
2419 | ||
2420 | HDEBUG(D_receive) | |
2421 | { if (helo_verified) debug_printf("matched host address\n"); } | |
2422 | } | |
2423 | ||
2424 | /* Do a reverse lookup if one hasn't already given a positive or negative | |
2425 | response. If that fails, or the name doesn't match, try checking with a forward | |
2426 | lookup. */ | |
2427 | ||
2428 | else | |
2429 | { | |
2430 | if (sender_host_name == NULL && !host_lookup_failed) | |
2431 | yield = host_name_lookup() != DEFER; | |
2432 | ||
2433 | /* If a host name is known, check it and all its aliases. */ | |
2434 | ||
2435 | if (sender_host_name != NULL) | |
2436 | { | |
2437 | helo_verified = strcmpic(sender_host_name, sender_helo_name) == 0; | |
2438 | ||
2439 | if (helo_verified) | |
2440 | { | |
2441 | HDEBUG(D_receive) debug_printf("matched host name\n"); | |
2442 | } | |
2443 | else | |
2444 | { | |
2445 | uschar **aliases = sender_host_aliases; | |
2446 | while (*aliases != NULL) | |
2447 | { | |
2448 | helo_verified = strcmpic(*aliases++, sender_helo_name) == 0; | |
2449 | if (helo_verified) break; | |
2450 | } | |
2451 | HDEBUG(D_receive) | |
2452 | { | |
2453 | if (helo_verified) | |
2454 | debug_printf("matched alias %s\n", *(--aliases)); | |
2455 | } | |
2456 | } | |
2457 | } | |
2458 | ||
2459 | /* Final attempt: try a forward lookup of the helo name */ | |
2460 | ||
2461 | if (!helo_verified) | |
2462 | { | |
2463 | int rc; | |
2464 | host_item h; | |
2465 | h.name = sender_helo_name; | |
2466 | h.address = NULL; | |
2467 | h.mx = MX_NONE; | |
2468 | h.next = NULL; | |
2469 | HDEBUG(D_receive) debug_printf("getting IP address for %s\n", | |
2470 | sender_helo_name); | |
322050c2 | 2471 | rc = host_find_byname(&h, NULL, 0, NULL, TRUE); |
d7b47fd0 PH |
2472 | if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL) |
2473 | { | |
2474 | host_item *hh = &h; | |
2475 | while (hh != NULL) | |
2476 | { | |
2477 | if (Ustrcmp(hh->address, sender_host_address) == 0) | |
2478 | { | |
2479 | helo_verified = TRUE; | |
2480 | HDEBUG(D_receive) | |
2481 | debug_printf("IP address for %s matches calling address\n", | |
2482 | sender_helo_name); | |
2483 | break; | |
2484 | } | |
2485 | hh = hh->next; | |
2486 | } | |
2487 | } | |
2488 | } | |
2489 | } | |
2490 | ||
d1d5595c | 2491 | if (!helo_verified) helo_verify_failed = TRUE; /* We've tried ... */ |
d7b47fd0 PH |
2492 | return yield; |
2493 | } | |
2494 | ||
2495 | ||
2496 | ||
2497 | ||
4e88a19f PH |
2498 | /************************************************* |
2499 | * Send user response message * | |
2500 | *************************************************/ | |
2501 | ||
2502 | /* This function is passed a default response code and a user message. It calls | |
2503 | smtp_message_code() to check and possibly modify the response code, and then | |
2504 | calls smtp_respond() to transmit the response. I put this into a function | |
2505 | just to avoid a lot of repetition. | |
2506 | ||
2507 | Arguments: | |
2508 | code the response code | |
2509 | user_msg the user message | |
2510 | ||
2511 | Returns: nothing | |
2512 | */ | |
2513 | ||
2514 | static void | |
2515 | smtp_user_msg(uschar *code, uschar *user_msg) | |
2516 | { | |
2517 | int len = 3; | |
2518 | smtp_message_code(&code, &len, &user_msg, NULL); | |
2519 | smtp_respond(code, len, TRUE, user_msg); | |
2520 | } | |
2521 | ||
2522 | ||
2523 | ||
2524 | ||
059ec3d9 PH |
2525 | /************************************************* |
2526 | * Initialize for SMTP incoming message * | |
2527 | *************************************************/ | |
2528 | ||
2529 | /* This function conducts the initial dialogue at the start of an incoming SMTP | |
2530 | message, and builds a list of recipients. However, if the incoming message | |
2531 | is part of a batch (-bS option) a separate function is called since it would | |
2532 | be messy having tests splattered about all over this function. This function | |
2533 | therefore handles the case where interaction is occurring. The input and output | |
2534 | files are set up in smtp_in and smtp_out. | |
2535 | ||
2536 | The global recipients_list is set to point to a vector of recipient_item | |
2537 | blocks, whose number is given by recipients_count. This is extended by the | |
2538 | receive_add_recipient() function. The global variable sender_address is set to | |
2539 | the sender's address. The yield is +1 if a message has been successfully | |
2540 | started, 0 if a QUIT command was encountered or the connection was refused from | |
2541 | the particular host, or -1 if the connection was lost. | |
2542 | ||
2543 | Argument: none | |
2544 | ||
2545 | Returns: > 0 message successfully started (reached DATA) | |
2546 | = 0 QUIT read or end of file reached or call refused | |
2547 | < 0 lost connection | |
2548 | */ | |
2549 | ||
2550 | int | |
2551 | smtp_setup_msg(void) | |
2552 | { | |
2553 | int done = 0; | |
2554 | BOOL toomany = FALSE; | |
2555 | BOOL discarded = FALSE; | |
2556 | BOOL last_was_rej_mail = FALSE; | |
2557 | BOOL last_was_rcpt = FALSE; | |
2558 | void *reset_point = store_get(0); | |
2559 | ||
2560 | DEBUG(D_receive) debug_printf("smtp_setup_msg entered\n"); | |
2561 | ||
2562 | /* Reset for start of new message. We allow one RSET not to be counted as a | |
2563 | nonmail command, for those MTAs that insist on sending it between every | |
2564 | message. Ditto for EHLO/HELO and for STARTTLS, to allow for going in and out of | |
2565 | TLS between messages (an Exim client may do this if it has messages queued up | |
2566 | for the host). Note: we do NOT reset AUTH at this point. */ | |
2567 | ||
2568 | smtp_reset(reset_point); | |
2569 | message_ended = END_NOTSTARTED; | |
2570 | ||
2571 | cmd_list[CMD_LIST_RSET].is_mail_cmd = TRUE; | |
2572 | cmd_list[CMD_LIST_HELO].is_mail_cmd = TRUE; | |
2573 | cmd_list[CMD_LIST_EHLO].is_mail_cmd = TRUE; | |
2574 | #ifdef SUPPORT_TLS | |
2575 | cmd_list[CMD_LIST_STARTTLS].is_mail_cmd = TRUE; | |
2576 | #endif | |
2577 | ||
2578 | /* Set the local signal handler for SIGTERM - it tries to end off tidily */ | |
2579 | ||
2580 | os_non_restarting_signal(SIGTERM, command_sigterm_handler); | |
2581 | ||
2582 | /* Batched SMTP is handled in a different function. */ | |
2583 | ||
2584 | if (smtp_batched_input) return smtp_setup_batch_msg(); | |
2585 | ||
2586 | /* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE | |
2587 | value. The values are 2 larger than the required yield of the function. */ | |
2588 | ||
2589 | while (done <= 0) | |
2590 | { | |
2591 | uschar **argv; | |
2592 | uschar *etrn_command; | |
2593 | uschar *etrn_serialize_key; | |
2594 | uschar *errmess; | |
4e88a19f PH |
2595 | uschar *log_msg, *smtp_code; |
2596 | uschar *user_msg = NULL; | |
059ec3d9 PH |
2597 | uschar *recipient = NULL; |
2598 | uschar *hello = NULL; | |
2599 | uschar *set_id = NULL; | |
2600 | uschar *s, *ss; | |
2601 | BOOL was_rej_mail = FALSE; | |
2602 | BOOL was_rcpt = FALSE; | |
2603 | void (*oldsignal)(int); | |
2604 | pid_t pid; | |
2605 | int start, end, sender_domain, recipient_domain; | |
2606 | int ptr, size, rc; | |
f78eb7c6 | 2607 | int c, i; |
059ec3d9 PH |
2608 | auth_instance *au; |
2609 | ||
2610 | switch(smtp_read_command(TRUE)) | |
2611 | { | |
2612 | /* The AUTH command is not permitted to occur inside a transaction, and may | |
c46782ef PH |
2613 | occur successfully only once per connection. Actually, that isn't quite |
2614 | true. When TLS is started, all previous information about a connection must | |
2615 | be discarded, so a new AUTH is permitted at that time. | |
2616 | ||
2617 | AUTH may only be used when it has been advertised. However, it seems that | |
2618 | there are clients that send AUTH when it hasn't been advertised, some of | |
2619 | them even doing this after HELO. And there are MTAs that accept this. Sigh. | |
2620 | So there's a get-out that allows this to happen. | |
059ec3d9 PH |
2621 | |
2622 | AUTH is initially labelled as a "nonmail command" so that one occurrence | |
2623 | doesn't get counted. We change the label here so that multiple failing | |
2624 | AUTHS will eventually hit the nonmail threshold. */ | |
2625 | ||
2626 | case AUTH_CMD: | |
b4ed4da0 | 2627 | HAD(SCH_AUTH); |
059ec3d9 PH |
2628 | authentication_failed = TRUE; |
2629 | cmd_list[CMD_LIST_AUTH].is_mail_cmd = FALSE; | |
2630 | ||
c46782ef | 2631 | if (!auth_advertised && !allow_auth_unadvertised) |
059ec3d9 PH |
2632 | { |
2633 | done = synprot_error(L_smtp_protocol_error, 503, NULL, | |
2634 | US"AUTH command used when not advertised"); | |
2635 | break; | |
2636 | } | |
2637 | if (sender_host_authenticated != NULL) | |
2638 | { | |
2639 | done = synprot_error(L_smtp_protocol_error, 503, NULL, | |
2640 | US"already authenticated"); | |
2641 | break; | |
2642 | } | |
2643 | if (sender_address != NULL) | |
2644 | { | |
2645 | done = synprot_error(L_smtp_protocol_error, 503, NULL, | |
2646 | US"not permitted in mail transaction"); | |
2647 | break; | |
2648 | } | |
2649 | ||
2650 | /* Check the ACL */ | |
2651 | ||
2652 | if (acl_smtp_auth != NULL) | |
2653 | { | |
64ffc24f | 2654 | rc = acl_check(ACL_WHERE_AUTH, NULL, acl_smtp_auth, &user_msg, &log_msg); |
059ec3d9 PH |
2655 | if (rc != OK) |
2656 | { | |
2657 | done = smtp_handle_acl_fail(ACL_WHERE_AUTH, rc, user_msg, log_msg); | |
2658 | break; | |
2659 | } | |
2660 | } | |
2661 | ||
2662 | /* Find the name of the requested authentication mechanism. */ | |
2663 | ||
ca86f471 PH |
2664 | s = smtp_cmd_data; |
2665 | while ((c = *smtp_cmd_data) != 0 && !isspace(c)) | |
059ec3d9 PH |
2666 | { |
2667 | if (!isalnum(c) && c != '-' && c != '_') | |
2668 | { | |
2669 | done = synprot_error(L_smtp_syntax_error, 501, NULL, | |
2670 | US"invalid character in authentication mechanism name"); | |
2671 | goto COMMAND_LOOP; | |
2672 | } | |
ca86f471 | 2673 | smtp_cmd_data++; |
059ec3d9 PH |
2674 | } |
2675 | ||
2676 | /* If not at the end of the line, we must be at white space. Terminate the | |
2677 | name and move the pointer on to any data that may be present. */ | |
2678 | ||
ca86f471 | 2679 | if (*smtp_cmd_data != 0) |
059ec3d9 | 2680 | { |
ca86f471 PH |
2681 | *smtp_cmd_data++ = 0; |
2682 | while (isspace(*smtp_cmd_data)) smtp_cmd_data++; | |
059ec3d9 PH |
2683 | } |
2684 | ||
2685 | /* Search for an authentication mechanism which is configured for use | |
c46782ef PH |
2686 | as a server and which has been advertised (unless, sigh, allow_auth_ |
2687 | unadvertised is set). */ | |
059ec3d9 PH |
2688 | |
2689 | for (au = auths; au != NULL; au = au->next) | |
2690 | { | |
2691 | if (strcmpic(s, au->public_name) == 0 && au->server && | |
c46782ef | 2692 | (au->advertised || allow_auth_unadvertised)) break; |
059ec3d9 PH |
2693 | } |
2694 | ||
2695 | if (au == NULL) | |
2696 | { | |
2697 | done = synprot_error(L_smtp_protocol_error, 504, NULL, | |
2698 | string_sprintf("%s authentication mechanism not supported", s)); | |
2699 | break; | |
2700 | } | |
2701 | ||
f78eb7c6 PH |
2702 | /* Run the checking code, passing the remainder of the command line as |
2703 | data. Initials the $auth<n> variables as empty. Initialize $0 empty and set | |
2704 | it as the only set numerical variable. The authenticator may set $auth<n> | |
2705 | and also set other numeric variables. The $auth<n> variables are preferred | |
2706 | nowadays; the numerical variables remain for backwards compatibility. | |
059ec3d9 | 2707 | |
f78eb7c6 PH |
2708 | Afterwards, have a go at expanding the set_id string, even if |
2709 | authentication failed - for bad passwords it can be useful to log the | |
2710 | userid. On success, require set_id to expand and exist, and put it in | |
2711 | authenticated_id. Save this in permanent store, as the working store gets | |
2712 | reset at HELO, RSET, etc. */ | |
2713 | ||
2714 | for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL; | |
059ec3d9 PH |
2715 | expand_nmax = 0; |
2716 | expand_nlength[0] = 0; /* $0 contains nothing */ | |
2717 | ||
ca86f471 | 2718 | c = (au->info->servercode)(au, smtp_cmd_data); |
059ec3d9 PH |
2719 | if (au->set_id != NULL) set_id = expand_string(au->set_id); |
2720 | expand_nmax = -1; /* Reset numeric variables */ | |
f78eb7c6 | 2721 | for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL; /* Reset $auth<n> */ |
059ec3d9 | 2722 | |
0612b098 PH |
2723 | /* The value of authenticated_id is stored in the spool file and printed in |
2724 | log lines. It must not contain binary zeros or newline characters. In | |
2725 | normal use, it never will, but when playing around or testing, this error | |
2726 | can (did) happen. To guard against this, ensure that the id contains only | |
2727 | printing characters. */ | |
2728 | ||
2729 | if (set_id != NULL) set_id = string_printing(set_id); | |
2730 | ||
059ec3d9 PH |
2731 | /* For the non-OK cases, set up additional logging data if set_id |
2732 | is not empty. */ | |
2733 | ||
2734 | if (c != OK) | |
2735 | { | |
2736 | if (set_id != NULL && *set_id != 0) | |
2737 | set_id = string_sprintf(" (set_id=%s)", set_id); | |
2738 | else set_id = US""; | |
2739 | } | |
2740 | ||
2741 | /* Switch on the result */ | |
2742 | ||
2743 | switch(c) | |
2744 | { | |
2745 | case OK: | |
2746 | if (au->set_id == NULL || set_id != NULL) /* Complete success */ | |
2747 | { | |
2748 | if (set_id != NULL) authenticated_id = string_copy_malloc(set_id); | |
2749 | sender_host_authenticated = au->name; | |
2750 | authentication_failed = FALSE; | |
2751 | received_protocol = | |
2752 | protocols[pextend + pauthed + ((tls_active >= 0)? pcrpted:0)] + | |
2753 | ((sender_host_address != NULL)? pnlocal : 0); | |
2754 | s = ss = US"235 Authentication succeeded"; | |
2755 | authenticated_by = au; | |
2756 | break; | |
2757 | } | |
2758 | ||
2759 | /* Authentication succeeded, but we failed to expand the set_id string. | |
2760 | Treat this as a temporary error. */ | |
2761 | ||
2762 | auth_defer_msg = expand_string_message; | |
2763 | /* Fall through */ | |
2764 | ||
2765 | case DEFER: | |
2766 | s = string_sprintf("435 Unable to authenticate at present%s", | |
2767 | auth_defer_user_msg); | |
2768 | ss = string_sprintf("435 Unable to authenticate at present%s: %s", | |
2769 | set_id, auth_defer_msg); | |
2770 | break; | |
2771 | ||
2772 | case BAD64: | |
2773 | s = ss = US"501 Invalid base64 data"; | |
2774 | break; | |
2775 | ||
2776 | case CANCELLED: | |
2777 | s = ss = US"501 Authentication cancelled"; | |
2778 | break; | |
2779 | ||
2780 | case UNEXPECTED: | |
2781 | s = ss = US"553 Initial data not expected"; | |
2782 | break; | |
2783 | ||
2784 | case FAIL: | |
2785 | s = US"535 Incorrect authentication data"; | |
2786 | ss = string_sprintf("535 Incorrect authentication data%s", set_id); | |
2787 | break; | |
2788 | ||
2789 | default: | |
2790 | s = US"435 Internal error"; | |
2791 | ss = string_sprintf("435 Internal error%s: return %d from authentication " | |
2792 | "check", set_id, c); | |
2793 | break; | |
2794 | } | |
2795 | ||
2796 | smtp_printf("%s\r\n", s); | |
2797 | if (c != OK) | |
2798 | log_write(0, LOG_MAIN|LOG_REJECT, "%s authenticator failed for %s: %s", | |
2799 | au->name, host_and_ident(FALSE), ss); | |
2800 | ||
2801 | break; /* AUTH_CMD */ | |
2802 | ||
2803 | /* The HELO/EHLO commands are permitted to appear in the middle of a | |
2804 | session as well as at the beginning. They have the effect of a reset in | |
2805 | addition to their other functions. Their absence at the start cannot be | |
2806 | taken to be an error. | |
2807 | ||
2808 | RFC 2821 says: | |
2809 | ||
2810 | If the EHLO command is not acceptable to the SMTP server, 501, 500, | |
2811 | or 502 failure replies MUST be returned as appropriate. The SMTP | |
2812 | server MUST stay in the same state after transmitting these replies | |
2813 | that it was in before the EHLO was received. | |
2814 | ||
2815 | Therefore, we do not do the reset until after checking the command for | |
2816 | acceptability. This change was made for Exim release 4.11. Previously | |
2817 | it did the reset first. */ | |
2818 | ||
2819 | case HELO_CMD: | |
b4ed4da0 | 2820 | HAD(SCH_HELO); |
059ec3d9 PH |
2821 | hello = US"HELO"; |
2822 | esmtp = FALSE; | |
2823 | goto HELO_EHLO; | |
2824 | ||
2825 | case EHLO_CMD: | |
b4ed4da0 | 2826 | HAD(SCH_EHLO); |
059ec3d9 PH |
2827 | hello = US"EHLO"; |
2828 | esmtp = TRUE; | |
2829 | ||
2830 | HELO_EHLO: /* Common code for HELO and EHLO */ | |
2831 | cmd_list[CMD_LIST_HELO].is_mail_cmd = FALSE; | |
2832 | cmd_list[CMD_LIST_EHLO].is_mail_cmd = FALSE; | |
2833 | ||
2834 | /* Reject the HELO if its argument was invalid or non-existent. A | |
2835 | successful check causes the argument to be saved in malloc store. */ | |
2836 | ||
ca86f471 | 2837 | if (!check_helo(smtp_cmd_data)) |
059ec3d9 PH |
2838 | { |
2839 | smtp_printf("501 Syntactically invalid %s argument(s)\r\n", hello); | |
2840 | ||
2841 | log_write(0, LOG_MAIN|LOG_REJECT, "rejected %s from %s: syntactically " | |
2842 | "invalid argument(s): %s", hello, host_and_ident(FALSE), | |
3ee512ff PH |
2843 | (*smtp_cmd_argument == 0)? US"(no argument given)" : |
2844 | string_printing(smtp_cmd_argument)); | |
059ec3d9 PH |
2845 | |
2846 | if (++synprot_error_count > smtp_max_synprot_errors) | |
2847 | { | |
2848 | log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many " | |
2849 | "syntax or protocol errors (last command was \"%s\")", | |
3ee512ff | 2850 | host_and_ident(FALSE), smtp_cmd_buffer); |
059ec3d9 PH |
2851 | done = 1; |
2852 | } | |
2853 | ||
2854 | break; | |
2855 | } | |
2856 | ||
2857 | /* If sender_host_unknown is true, we have got here via the -bs interface, | |
2858 | not called from inetd. Otherwise, we are running an IP connection and the | |
2859 | host address will be set. If the helo name is the primary name of this | |
2860 | host and we haven't done a reverse lookup, force one now. If helo_required | |
2861 | is set, ensure that the HELO name matches the actual host. If helo_verify | |
2862 | is set, do the same check, but softly. */ | |
2863 | ||
2864 | if (!sender_host_unknown) | |
2865 | { | |
2866 | BOOL old_helo_verified = helo_verified; | |
ca86f471 | 2867 | uschar *p = smtp_cmd_data; |
059ec3d9 PH |
2868 | |
2869 | while (*p != 0 && !isspace(*p)) { *p = tolower(*p); p++; } | |
2870 | *p = 0; | |
2871 | ||
2872 | /* Force a reverse lookup if HELO quoted something in helo_lookup_domains | |
2873 | because otherwise the log can be confusing. */ | |
2874 | ||
2875 | if (sender_host_name == NULL && | |
2876 | (deliver_domain = sender_helo_name, /* set $domain */ | |
2877 | match_isinlist(sender_helo_name, &helo_lookup_domains, 0, | |
2878 | &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL)) == OK) | |
2879 | (void)host_name_lookup(); | |
2880 | ||
2881 | /* Rebuild the fullhost info to include the HELO name (and the real name | |
2882 | if it was looked up.) */ | |
2883 | ||
2884 | host_build_sender_fullhost(); /* Rebuild */ | |
2885 | set_process_info("handling%s incoming connection from %s", | |
2886 | (tls_active >= 0)? " TLS" : "", host_and_ident(FALSE)); | |
2887 | ||
2888 | /* Verify if configured. This doesn't give much security, but it does | |
d7b47fd0 PH |
2889 | make some people happy to be able to do it. If helo_required is set, |
2890 | (host matches helo_verify_hosts) failure forces rejection. If helo_verify | |
2891 | is set (host matches helo_try_verify_hosts), it does not. This is perhaps | |
2892 | now obsolescent, since the verification can now be requested selectively | |
2893 | at ACL time. */ | |
059ec3d9 | 2894 | |
d7b47fd0 | 2895 | helo_verified = helo_verify_failed = FALSE; |
059ec3d9 PH |
2896 | if (helo_required || helo_verify) |
2897 | { | |
d7b47fd0 | 2898 | BOOL tempfail = !smtp_verify_helo(); |
059ec3d9 PH |
2899 | if (!helo_verified) |
2900 | { | |
2901 | if (helo_required) | |
2902 | { | |
2903 | smtp_printf("%d %s argument does not match calling host\r\n", | |
2904 | tempfail? 451 : 550, hello); | |
2905 | log_write(0, LOG_MAIN|LOG_REJECT, "%srejected \"%s %s\" from %s", | |
2906 | tempfail? "temporarily " : "", | |
2907 | hello, sender_helo_name, host_and_ident(FALSE)); | |
2908 | helo_verified = old_helo_verified; | |
2909 | break; /* End of HELO/EHLO processing */ | |
2910 | } | |
2911 | HDEBUG(D_all) debug_printf("%s verification failed but host is in " | |
2912 | "helo_try_verify_hosts\n", hello); | |
2913 | } | |
2914 | } | |
2915 | } | |
2916 | ||
8523533c TK |
2917 | #ifdef EXPERIMENTAL_SPF |
2918 | /* set up SPF context */ | |
2919 | spf_init(sender_helo_name, sender_host_address); | |
2920 | #endif | |
2921 | ||
a14e5636 PH |
2922 | /* Apply an ACL check if one is defined; afterwards, recheck |
2923 | synchronization in case the client started sending in a delay. */ | |
059ec3d9 PH |
2924 | |
2925 | if (acl_smtp_helo != NULL) | |
2926 | { | |
64ffc24f | 2927 | rc = acl_check(ACL_WHERE_HELO, NULL, acl_smtp_helo, &user_msg, &log_msg); |
059ec3d9 PH |
2928 | if (rc != OK) |
2929 | { | |
2930 | done = smtp_handle_acl_fail(ACL_WHERE_HELO, rc, user_msg, log_msg); | |
2931 | sender_helo_name = NULL; | |
2932 | host_build_sender_fullhost(); /* Rebuild */ | |
2933 | break; | |
2934 | } | |
a14e5636 | 2935 | else if (!check_sync()) goto SYNC_FAILURE; |
059ec3d9 PH |
2936 | } |
2937 | ||
4e88a19f PH |
2938 | /* Generate an OK reply. The default string includes the ident if present, |
2939 | and also the IP address if present. Reflecting back the ident is intended | |
2940 | as a deterrent to mail forgers. For maximum efficiency, and also because | |
2941 | some broken systems expect each response to be in a single packet, arrange | |
2942 | that the entire reply is sent in one write(). */ | |
059ec3d9 PH |
2943 | |
2944 | auth_advertised = FALSE; | |
2945 | pipelining_advertised = FALSE; | |
2946 | #ifdef SUPPORT_TLS | |
2947 | tls_advertised = FALSE; | |
2948 | #endif | |
2949 | ||
d6a96edc | 2950 | smtp_code = US"250 "; /* Default response code plus space*/ |
4e88a19f PH |
2951 | if (user_msg == NULL) |
2952 | { | |
2953 | s = string_sprintf("%.3s %s Hello %s%s%s", | |
2954 | smtp_code, | |
2955 | smtp_active_hostname, | |
2956 | (sender_ident == NULL)? US"" : sender_ident, | |
2957 | (sender_ident == NULL)? US"" : US" at ", | |
2958 | (sender_host_name == NULL)? sender_helo_name : sender_host_name); | |
2959 | ||
2960 | ptr = Ustrlen(s); | |
2961 | size = ptr + 1; | |
059ec3d9 | 2962 | |
4e88a19f PH |
2963 | if (sender_host_address != NULL) |
2964 | { | |
2965 | s = string_cat(s, &size, &ptr, US" [", 2); | |
2966 | s = string_cat(s, &size, &ptr, sender_host_address, | |
2967 | Ustrlen(sender_host_address)); | |
2968 | s = string_cat(s, &size, &ptr, US"]", 1); | |
2969 | } | |
2970 | } | |
2971 | ||
d6a96edc PH |
2972 | /* A user-supplied EHLO greeting may not contain more than one line. Note |
2973 | that the code returned by smtp_message_code() includes the terminating | |
2974 | whitespace character. */ | |
059ec3d9 | 2975 | |
4e88a19f | 2976 | else |
059ec3d9 | 2977 | { |
4e88a19f | 2978 | char *ss; |
d6a96edc | 2979 | int codelen = 4; |
4e88a19f | 2980 | smtp_message_code(&smtp_code, &codelen, &user_msg, NULL); |
d6a96edc | 2981 | s = string_sprintf("%.*s%s", codelen, smtp_code, user_msg); |
4e88a19f PH |
2982 | if ((ss = strpbrk(CS s, "\r\n")) != NULL) |
2983 | { | |
2984 | log_write(0, LOG_MAIN|LOG_PANIC, "EHLO/HELO response must not contain " | |
2985 | "newlines: message truncated: %s", string_printing(s)); | |
2986 | *ss = 0; | |
2987 | } | |
2988 | ptr = Ustrlen(s); | |
2989 | size = ptr + 1; | |
059ec3d9 PH |
2990 | } |
2991 | ||
2992 | s = string_cat(s, &size, &ptr, US"\r\n", 2); | |
2993 | ||
2994 | /* If we received EHLO, we must create a multiline response which includes | |
2995 | the functions supported. */ | |
2996 | ||
2997 | if (esmtp) | |
2998 | { | |
2999 | s[3] = '-'; | |
3000 | ||
3001 | /* I'm not entirely happy with this, as an MTA is supposed to check | |
3002 | that it has enough room to accept a message of maximum size before | |
3003 | it sends this. However, there seems little point in not sending it. | |
3004 | The actual size check happens later at MAIL FROM time. By postponing it | |
3005 | till then, VRFY and EXPN can be used after EHLO when space is short. */ | |
3006 | ||
3007 | if (thismessage_size_limit > 0) | |
3008 | { | |
4e88a19f PH |
3009 | sprintf(CS big_buffer, "%.3s-SIZE %d\r\n", smtp_code, |
3010 | thismessage_size_limit); | |
059ec3d9 PH |
3011 | s = string_cat(s, &size, &ptr, big_buffer, Ustrlen(big_buffer)); |
3012 | } | |
3013 | else | |
3014 | { | |
4e88a19f PH |
3015 | s = string_cat(s, &size, &ptr, smtp_code, 3); |
3016 | s = string_cat(s, &size, &ptr, US"-SIZE\r\n", 7); | |
059ec3d9 PH |
3017 | } |
3018 | ||
3019 | /* Exim does not do protocol conversion or data conversion. It is 8-bit | |
3020 | clean; if it has an 8-bit character in its hand, it just sends it. It | |
3021 | cannot therefore specify 8BITMIME and remain consistent with the RFCs. | |
3022 | However, some users want this option simply in order to stop MUAs | |
3023 | mangling messages that contain top-bit-set characters. It is therefore | |
3024 | provided as an option. */ | |
3025 | ||
3026 | if (accept_8bitmime) | |
4e88a19f PH |
3027 | { |
3028 | s = string_cat(s, &size, &ptr, smtp_code, 3); | |
3029 | s = string_cat(s, &size, &ptr, US"-8BITMIME\r\n", 11); | |
3030 | } | |
059ec3d9 PH |
3031 | |
3032 | /* Advertise ETRN if there's an ACL checking whether a host is | |
3033 | permitted to issue it; a check is made when any host actually tries. */ | |
3034 | ||
3035 | if (acl_smtp_etrn != NULL) | |
3036 | { | |
4e88a19f PH |
3037 | s = string_cat(s, &size, &ptr, smtp_code, 3); |
3038 | s = string_cat(s, &size, &ptr, US"-ETRN\r\n", 7); | |
059ec3d9 PH |
3039 | } |
3040 | ||
3041 | /* Advertise EXPN if there's an ACL checking whether a host is | |
3042 | permitted to issue it; a check is made when any host actually tries. */ | |
3043 | ||
3044 | if (acl_smtp_expn != NULL) | |
3045 | { | |
4e88a19f PH |
3046 | s = string_cat(s, &size, &ptr, smtp_code, 3); |
3047 | s = string_cat(s, &size, &ptr, US"-EXPN\r\n", 7); | |
059ec3d9 PH |
3048 | } |
3049 | ||
3050 | /* Exim is quite happy with pipelining, so let the other end know that | |
3051 | it is safe to use it, unless advertising is disabled. */ | |
3052 | ||
cf8b11a5 PH |
3053 | if (pipelining_enable && |
3054 | verify_check_host(&pipelining_advertise_hosts) == OK) | |
059ec3d9 | 3055 | { |
4e88a19f PH |
3056 | s = string_cat(s, &size, &ptr, smtp_code, 3); |
3057 | s = string_cat(s, &size, &ptr, US"-PIPELINING\r\n", 13); | |
059ec3d9 PH |
3058 | sync_cmd_limit = NON_SYNC_CMD_PIPELINING; |
3059 | pipelining_advertised = TRUE; | |
3060 | } | |
3061 | ||
3062 | /* If any server authentication mechanisms are configured, advertise | |
3063 | them if the current host is in auth_advertise_hosts. The problem with | |
3064 | advertising always is that some clients then require users to | |
3065 | authenticate (and aren't configurable otherwise) even though it may not | |
3066 | be necessary (e.g. if the host is in host_accept_relay). | |
3067 | ||
3068 | RFC 2222 states that SASL mechanism names contain only upper case | |
3069 | letters, so output the names in upper case, though we actually recognize | |
3070 | them in either case in the AUTH command. */ | |
3071 | ||
3072 | if (auths != NULL) | |
3073 | { | |
3074 | if (verify_check_host(&auth_advertise_hosts) == OK) | |
3075 | { | |
3076 | auth_instance *au; | |
3077 | BOOL first = TRUE; | |
3078 | for (au = auths; au != NULL; au = au->next) | |
3079 | { | |
3080 | if (au->server && (au->advertise_condition == NULL || | |
3081 | expand_check_condition(au->advertise_condition, au->name, | |
3082 | US"authenticator"))) | |
3083 | { | |
3084 | int saveptr; | |
3085 | if (first) | |
3086 | { | |
4e88a19f PH |
3087 | s = string_cat(s, &size, &ptr, smtp_code, 3); |
3088 | s = string_cat(s, &size, &ptr, US"-AUTH", 5); | |
059ec3d9 PH |
3089 | first = FALSE; |
3090 | auth_advertised = TRUE; | |
3091 | } | |
3092 | saveptr = ptr; | |
3093 | s = string_cat(s, &size, &ptr, US" ", 1); | |
3094 | s = string_cat(s, &size, &ptr, au->public_name, | |
3095 | Ustrlen(au->public_name)); | |
3096 | while (++saveptr < ptr) s[saveptr] = toupper(s[saveptr]); | |
3097 | au->advertised = TRUE; | |
3098 | } | |
3099 | else au->advertised = FALSE; | |
3100 | } | |
3101 | if (!first) s = string_cat(s, &size, &ptr, US"\r\n", 2); | |
3102 | } | |
3103 | } | |
3104 | ||
3105 | /* Advertise TLS (Transport Level Security) aka SSL (Secure Socket Layer) | |
3106 | if it has been included in the binary, and the host matches | |
3107 | tls_advertise_hosts. We must *not* advertise if we are already in a | |
3108 | secure connection. */ | |
3109 | ||
3110 | #ifdef SUPPORT_TLS | |
3111 | if (tls_active < 0 && | |
3112 | verify_check_host(&tls_advertise_hosts) != FAIL) | |
3113 | { | |
4e88a19f PH |
3114 | s = string_cat(s, &size, &ptr, smtp_code, 3); |
3115 | s = string_cat(s, &size, &ptr, US"-STARTTLS\r\n", 11); | |
059ec3d9 PH |
3116 | tls_advertised = TRUE; |
3117 | } | |
3118 | #endif | |
3119 | ||
3120 | /* Finish off the multiline reply with one that is always available. */ | |
3121 | ||
4e88a19f PH |
3122 | s = string_cat(s, &size, &ptr, smtp_code, 3); |
3123 | s = string_cat(s, &size, &ptr, US" HELP\r\n", 7); | |
059ec3d9 PH |
3124 | } |
3125 | ||
3126 | /* Terminate the string (for debug), write it, and note that HELO/EHLO | |
3127 | has been seen. */ | |
3128 | ||
3129 | s[ptr] = 0; | |
3130 | ||
3131 | #ifdef SUPPORT_TLS | |
3132 | if (tls_active >= 0) (void)tls_write(s, ptr); else | |
3133 | #endif | |
3134 | ||
f1e894f3 | 3135 | (void)fwrite(s, 1, ptr, smtp_out); |
898d150f PH |
3136 | DEBUG(D_receive) |
3137 | { | |
3138 | uschar *cr; | |
3139 | while ((cr = Ustrchr(s, '\r')) != NULL) /* lose CRs */ | |
3140 | memmove(cr, cr + 1, (ptr--) - (cr - s)); | |
3141 | debug_printf("SMTP>> %s", s); | |
3142 | } | |
059ec3d9 | 3143 | helo_seen = TRUE; |
4e88a19f PH |
3144 | |
3145 | /* Reset the protocol and the state, abandoning any previous message. */ | |
3146 | ||
3147 | received_protocol = (esmtp? | |
3148 | protocols[pextend + | |
3149 | ((sender_host_authenticated != NULL)? pauthed : 0) + | |
3150 | ((tls_active >= 0)? pcrpted : 0)] | |
3151 | : | |
3152 | protocols[pnormal + ((tls_active >= 0)? pcrpted : 0)]) | |
3153 | + | |
3154 | ((sender_host_address != NULL)? pnlocal : 0); | |
3155 | ||
3156 | smtp_reset(reset_point); | |
3157 | toomany = FALSE; | |
059ec3d9 PH |
3158 | break; /* HELO/EHLO */ |
3159 | ||
3160 | ||
3161 | /* The MAIL command requires an address as an operand. All we do | |
3162 | here is to parse it for syntactic correctness. The form "<>" is | |
3163 | a special case which converts into an empty string. The start/end | |
3164 | pointers in the original are not used further for this address, as | |
3165 | it is the canonical extracted address which is all that is kept. */ | |
3166 | ||
3167 | case MAIL_CMD: | |
b4ed4da0 | 3168 | HAD(SCH_MAIL); |
059ec3d9 PH |
3169 | smtp_mailcmd_count++; /* Count for limit and ratelimit */ |
3170 | was_rej_mail = TRUE; /* Reset if accepted */ | |
3171 | ||
3172 | if (helo_required && !helo_seen) | |
3173 | { | |
3174 | smtp_printf("503 HELO or EHLO required\r\n"); | |
3175 | log_write(0, LOG_MAIN|LOG_REJECT, "rejected MAIL from %s: no " | |
3176 | "HELO/EHLO given", host_and_ident(FALSE)); | |
3177 | break; | |
3178 | } | |
3179 | ||
3180 | if (sender_address != NULL) | |
3181 | { | |
3182 | done = synprot_error(L_smtp_protocol_error, 503, NULL, | |
3183 | US"sender already given"); | |
3184 | break; | |
3185 | } | |
3186 | ||
ca86f471 | 3187 | if (smtp_cmd_data[0] == 0) |
059ec3d9 PH |
3188 | { |
3189 | done = synprot_error(L_smtp_protocol_error, 501, NULL, | |
3190 | US"MAIL must have an address operand"); | |
3191 | break; | |
3192 | } | |
3193 | ||
3194 | /* Check to see if the limit for messages per connection would be | |
3195 | exceeded by accepting further messages. */ | |
3196 | ||
3197 | if (smtp_accept_max_per_connection > 0 && | |
3198 | smtp_mailcmd_count > smtp_accept_max_per_connection) | |
3199 | { | |
3200 | smtp_printf("421 too many messages in this connection\r\n"); | |
3201 | log_write(0, LOG_MAIN|LOG_REJECT, "rejected MAIL command %s: too many " | |
3202 | "messages in one connection", host_and_ident(TRUE)); | |
3203 | break; | |
3204 | } | |
3205 | ||
3206 | /* Reset for start of message - even if this is going to fail, we | |
3207 | obviously need to throw away any previous data. */ | |
3208 | ||
3209 | smtp_reset(reset_point); | |
3210 | toomany = FALSE; | |
3211 | sender_data = recipient_data = NULL; | |
3212 | ||
3213 | /* Loop, checking for ESMTP additions to the MAIL FROM command. */ | |
3214 | ||
3215 | if (esmtp) for(;;) | |
3216 | { | |
3217 | uschar *name, *value, *end; | |
3218 | unsigned long int size; | |
3219 | ||
3220 | if (!extract_option(&name, &value)) break; | |
3221 | ||
3222 | /* Handle SIZE= by reading the value. We don't do the check till later, | |
3223 | in order to be able to log the sender address on failure. */ | |
3224 | ||
3225 | if (strcmpic(name, US"SIZE") == 0 && | |
a4dc33a8 | 3226 | ((size = Ustrtoul(value, &end, 10)), *end == 0)) |
059ec3d9 PH |
3227 | { |
3228 | if ((size == ULONG_MAX && errno == ERANGE) || size > INT_MAX) | |
3229 | size = INT_MAX; | |
3230 | message_size = (int)size; | |
3231 | } | |
3232 | ||
3233 | /* If this session was initiated with EHLO and accept_8bitmime is set, | |
3234 | Exim will have indicated that it supports the BODY=8BITMIME option. In | |
3235 | fact, it does not support this according to the RFCs, in that it does not | |
3236 | take any special action for forwarding messages containing 8-bit | |
3237 | characters. That is why accept_8bitmime is not the default setting, but | |
3238 | some sites want the action that is provided. We recognize both "8BITMIME" | |
3239 | and "7BIT" as body types, but take no action. */ | |
3240 | ||
3241 | else if (accept_8bitmime && strcmpic(name, US"BODY") == 0 && | |
3242 | (strcmpic(value, US"8BITMIME") == 0 || | |
3243 | strcmpic(value, US"7BIT") == 0)) {} | |
3244 | ||
3245 | /* Handle the AUTH extension. If the value given is not "<>" and either | |
3246 | the ACL says "yes" or there is no ACL but the sending host is | |
3247 | authenticated, we set it up as the authenticated sender. However, if the | |
3248 | authenticator set a condition to be tested, we ignore AUTH on MAIL unless | |
3249 | the condition is met. The value of AUTH is an xtext, which means that +, | |
3250 | = and cntrl chars are coded in hex; however "<>" is unaffected by this | |
3251 | coding. */ | |
3252 | ||
3253 | else if (strcmpic(name, US"AUTH") == 0) | |
3254 | { | |
3255 | if (Ustrcmp(value, "<>") != 0) | |
3256 | { | |
3257 | int rc; | |
3258 | uschar *ignore_msg; | |
3259 | ||
3260 | if (auth_xtextdecode(value, &authenticated_sender) < 0) | |
3261 | { | |
3262 | /* Put back terminator overrides for error message */ | |
3263 | name[-1] = ' '; | |
3264 | value[-1] = '='; | |
3265 | done = synprot_error(L_smtp_syntax_error, 501, NULL, | |
3266 | US"invalid data for AUTH"); | |
3267 | goto COMMAND_LOOP; | |
3268 | } | |
3269 | ||
3270 | if (acl_smtp_mailauth == NULL) | |
3271 | { | |
3272 | ignore_msg = US"client not authenticated"; | |
3273 | rc = (sender_host_authenticated != NULL)? OK : FAIL; | |
3274 | } | |
3275 | else | |
3276 | { | |
3277 | ignore_msg = US"rejected by ACL"; | |
3278 | rc = acl_check(ACL_WHERE_MAILAUTH, NULL, acl_smtp_mailauth, | |
3279 | &user_msg, &log_msg); | |
3280 | } | |
3281 | ||
3282 | switch (rc) | |
3283 | { | |
3284 | case OK: | |
3285 | if (authenticated_by == NULL || | |
3286 | authenticated_by->mail_auth_condition == NULL || | |
3287 | expand_check_condition(authenticated_by->mail_auth_condition, | |
3288 | authenticated_by->name, US"authenticator")) | |
3289 | break; /* Accept the AUTH */ | |
3290 | ||
3291 | ignore_msg = US"server_mail_auth_condition failed"; | |
3292 | if (authenticated_id != NULL) | |
3293 | ignore_msg = string_sprintf("%s: authenticated ID=\"%s\"", | |
3294 | ignore_msg, authenticated_id); | |
3295 | ||
3296 | /* Fall through */ | |
3297 | ||
3298 | case FAIL: | |
3299 | authenticated_sender = NULL; | |
3300 | log_write(0, LOG_MAIN, "ignoring AUTH=%s from %s (%s)", | |
3301 | value, host_and_ident(TRUE), ignore_msg); | |
3302 | break; | |
3303 | ||
3304 | /* Should only get DEFER or ERROR here. Put back terminator | |
3305 | overrides for error message */ | |
3306 | ||
3307 | default: | |
3308 | name[-1] = ' '; | |
3309 | value[-1] = '='; | |
3310 | (void)smtp_handle_acl_fail(ACL_WHERE_MAILAUTH, rc, user_msg, | |
3311 | log_msg); | |
3312 | goto COMMAND_LOOP; | |
3313 | } | |
3314 | } | |
3315 | } | |
3316 | ||
3317 | /* Unknown option. Stick back the terminator characters and break | |
3318 | the loop. An error for a malformed address will occur. */ | |
3319 | ||
3320 | else | |
3321 | { | |
3322 | name[-1] = ' '; | |
3323 | value[-1] = '='; | |
3324 | break; | |
3325 | } | |
3326 | } | |
3327 | ||
3328 | /* If we have passed the threshold for rate limiting, apply the current | |
3329 | delay, and update it for next time, provided this is a limited host. */ | |
3330 | ||
3331 | if (smtp_mailcmd_count > smtp_rlm_threshold && | |
3332 | verify_check_host(&smtp_ratelimit_hosts) == OK) | |
3333 | { | |
3334 | DEBUG(D_receive) debug_printf("rate limit MAIL: delay %.3g sec\n", | |
3335 | smtp_delay_mail/1000.0); | |
3336 | millisleep((int)smtp_delay_mail); | |
3337 | smtp_delay_mail *= smtp_rlm_factor; | |
3338 | if (smtp_delay_mail > (double)smtp_rlm_limit) | |
3339 | smtp_delay_mail = (double)smtp_rlm_limit; | |
3340 | } | |
3341 | ||
3342 | /* Now extract the address, first applying any SMTP-time rewriting. The | |
3343 | TRUE flag allows "<>" as a sender address. */ | |
3344 | ||
3345 | raw_sender = ((rewrite_existflags & rewrite_smtp) != 0)? | |
ca86f471 PH |
3346 | rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"", |
3347 | global_rewrite_rules) : smtp_cmd_data; | |
059ec3d9 PH |
3348 | |
3349 | /* rfc821_domains = TRUE; << no longer needed */ | |
3350 | raw_sender = | |
3351 | parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain, | |
3352 | TRUE); | |
3353 | /* rfc821_domains = FALSE; << no longer needed */ | |
3354 | ||
3355 | if (raw_sender == NULL) | |
3356 | { | |
ca86f471 | 3357 | done = synprot_error(L_smtp_syntax_error, 501, smtp_cmd_data, errmess); |
059ec3d9 PH |
3358 | break; |
3359 | } | |
3360 | ||
3361 | sender_address = raw_sender; | |
3362 | ||
3363 | /* If there is a configured size limit for mail, check that this message | |
3364 | doesn't exceed it. The check is postponed to this point so that the sender | |
3365 | can be logged. */ | |
3366 | ||
3367 | if (thismessage_size_limit > 0 && message_size > thismessage_size_limit) | |
3368 | { | |
3369 | smtp_printf("552 Message size exceeds maximum permitted\r\n"); | |
3370 | log_write(L_size_reject, | |
3371 | LOG_MAIN|LOG_REJECT, "rejected MAIL FROM:<%s> %s: " | |
3372 | "message too big: size%s=%d max=%d", | |
3373 | sender_address, | |
3374 | host_and_ident(TRUE), | |
3375 | (message_size == INT_MAX)? ">" : "", | |
3376 | message_size, | |
3377 | thismessage_size_limit); | |
3378 | sender_address = NULL; | |
3379 | break; | |
3380 | } | |
3381 | ||
3382 | /* Check there is enough space on the disk unless configured not to. | |
3383 | When smtp_check_spool_space is set, the check is for thismessage_size_limit | |
3384 | plus the current message - i.e. we accept the message only if it won't | |
3385 | reduce the space below the threshold. Add 5000 to the size to allow for | |
3386 | overheads such as the Received: line and storing of recipients, etc. | |
3387 | By putting the check here, even when SIZE is not given, it allow VRFY | |
3388 | and EXPN etc. to be used when space is short. */ | |
3389 | ||
3390 | if (!receive_check_fs( | |
3391 | (smtp_check_spool_space && message_size >= 0)? | |
3392 | message_size + 5000 : 0)) | |
3393 | { | |
3394 | smtp_printf("452 Space shortage, please try later\r\n"); | |
3395 | sender_address = NULL; | |
3396 | break; | |
3397 | } | |
3398 | ||
3399 | /* If sender_address is unqualified, reject it, unless this is a locally | |
3400 | generated message, or the sending host or net is permitted to send | |
3401 | unqualified addresses - typically local machines behaving as MUAs - | |
3402 | in which case just qualify the address. The flag is set above at the start | |
3403 | of the SMTP connection. */ | |
3404 | ||
3405 | if (sender_domain == 0 && sender_address[0] != 0) | |
3406 | { | |
3407 | if (allow_unqualified_sender) | |
3408 | { | |
3409 | sender_domain = Ustrlen(sender_address) + 1; | |
3410 | sender_address = rewrite_address_qualify(sender_address, FALSE); | |
3411 | DEBUG(D_receive) debug_printf("unqualified address %s accepted\n", | |
3412 | raw_sender); | |
3413 | } | |
3414 | else | |
3415 | { | |
3416 | smtp_printf("501 %s: sender address must contain a domain\r\n", | |
ca86f471 | 3417 | smtp_cmd_data); |
059ec3d9 PH |
3418 | log_write(L_smtp_syntax_error, |
3419 | LOG_MAIN|LOG_REJECT, | |
3420 | "unqualified sender rejected: <%s> %s%s", | |
3421 | raw_sender, | |
3422 | host_and_ident(TRUE), | |
3423 | host_lookup_msg); | |
3424 | sender_address = NULL; | |
3425 | break; | |
3426 | } | |
3427 | } | |
3428 | ||
a14e5636 PH |
3429 | /* Apply an ACL check if one is defined, before responding. Afterwards, |
3430 | when pipelining is not advertised, do another sync check in case the ACL | |
3431 | delayed and the client started sending in the meantime. */ | |
059ec3d9 | 3432 | |
a14e5636 PH |
3433 | if (acl_smtp_mail == NULL) rc = OK; else |
3434 | { | |
3435 | rc = acl_check(ACL_WHERE_MAIL, NULL, acl_smtp_mail, &user_msg, &log_msg); | |
3436 | if (rc == OK && !pipelining_advertised && !check_sync()) | |
3437 | goto SYNC_FAILURE; | |
3438 | } | |
059ec3d9 PH |
3439 | |
3440 | if (rc == OK || rc == DISCARD) | |
3441 | { | |
4e88a19f PH |
3442 | if (user_msg == NULL) smtp_printf("250 OK\r\n"); |
3443 | else smtp_user_msg(US"250", user_msg); | |
059ec3d9 PH |
3444 | smtp_delay_rcpt = smtp_rlr_base; |
3445 | recipients_discarded = (rc == DISCARD); | |
3446 | was_rej_mail = FALSE; | |
3447 | } | |
059ec3d9 PH |
3448 | else |
3449 | { | |
3450 | done = smtp_handle_acl_fail(ACL_WHERE_MAIL, rc, user_msg, log_msg); | |
3451 | sender_address = NULL; | |
3452 | } | |
3453 | break; | |
3454 | ||
3455 | ||
2679d413 PH |
3456 | /* The RCPT command requires an address as an operand. There may be any |
3457 | number of RCPT commands, specifying multiple recipients. We build them all | |
3458 | into a data structure. The start/end values given by parse_extract_address | |
3459 | are not used, as we keep only the extracted address. */ | |
059ec3d9 PH |
3460 | |
3461 | case RCPT_CMD: | |
b4ed4da0 | 3462 | HAD(SCH_RCPT); |
059ec3d9 | 3463 | rcpt_count++; |
2679d413 | 3464 | was_rcpt = rcpt_in_progress = TRUE; |
059ec3d9 PH |
3465 | |
3466 | /* There must be a sender address; if the sender was rejected and | |
3467 | pipelining was advertised, we assume the client was pipelining, and do not | |
3468 | count this as a protocol error. Reset was_rej_mail so that further RCPTs | |
3469 | get the same treatment. */ | |
3470 | ||
3471 | if (sender_address == NULL) | |
3472 | { | |
3473 | if (pipelining_advertised && last_was_rej_mail) | |
3474 | { | |
3475 | smtp_printf("503 sender not yet given\r\n"); | |
3476 | was_rej_mail = TRUE; | |
3477 | } | |
3478 | else | |
3479 | { | |
3480 | done = synprot_error(L_smtp_protocol_error, 503, NULL, | |
3481 | US"sender not yet given"); | |
3482 | was_rcpt = FALSE; /* Not a valid RCPT */ | |
3483 | } | |
3484 | rcpt_fail_count++; | |
3485 | break; | |
3486 | } | |
3487 | ||
3488 | /* Check for an operand */ | |
3489 | ||
ca86f471 | 3490 | if (smtp_cmd_data[0] == 0) |
059ec3d9 PH |
3491 | { |
3492 | done = synprot_error(L_smtp_syntax_error, 501, NULL, | |
3493 | US"RCPT must have an address operand"); | |
3494 | rcpt_fail_count++; | |
3495 | break; | |
3496 | } | |
3497 | ||
3498 | /* Apply SMTP rewriting then extract the working address. Don't allow "<>" | |
3499 | as a recipient address */ | |
3500 | ||
3501 | recipient = ((rewrite_existflags & rewrite_smtp) != 0)? | |
ca86f471 PH |
3502 | rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"", |
3503 | global_rewrite_rules) : smtp_cmd_data; | |
059ec3d9 PH |
3504 | |
3505 | /* rfc821_domains = TRUE; << no longer needed */ | |
3506 | recipient = parse_extract_address(recipient, &errmess, &start, &end, | |
3507 | &recipient_domain, FALSE); | |
3508 | /* rfc821_domains = FALSE; << no longer needed */ | |
3509 | ||
3510 | if (recipient == NULL) | |
3511 | { | |
ca86f471 | 3512 | done = synprot_error(L_smtp_syntax_error, 501, smtp_cmd_data, errmess); |
059ec3d9 PH |
3513 | rcpt_fail_count++; |
3514 | break; | |
3515 | } | |
3516 | ||
3517 | /* If the recipient address is unqualified, reject it, unless this is a | |
3518 | locally generated message. However, unqualified addresses are permitted | |
3519 | from a configured list of hosts and nets - typically when behaving as | |
3520 | MUAs rather than MTAs. Sad that SMTP is used for both types of traffic, | |
3521 | really. The flag is set at the start of the SMTP connection. | |
3522 | ||
3523 | RFC 1123 talks about supporting "the reserved mailbox postmaster"; I always | |
3524 | assumed this meant "reserved local part", but the revision of RFC 821 and | |
3525 | friends now makes it absolutely clear that it means *mailbox*. Consequently | |
3526 | we must always qualify this address, regardless. */ | |
3527 | ||
3528 | if (recipient_domain == 0) | |
3529 | { | |
3530 | if (allow_unqualified_recipient || | |
3531 | strcmpic(recipient, US"postmaster") == 0) | |
3532 | { | |
3533 | DEBUG(D_receive) debug_printf("unqualified address %s accepted\n", | |
3534 | recipient); | |
3535 | recipient_domain = Ustrlen(recipient) + 1; | |
3536 | recipient = rewrite_address_qualify(recipient, TRUE); | |
3537 | } | |
3538 | else | |
3539 | { | |
3540 | rcpt_fail_count++; | |
3541 | smtp_printf("501 %s: recipient address must contain a domain\r\n", | |
ca86f471 | 3542 | smtp_cmd_data); |
059ec3d9 PH |
3543 | log_write(L_smtp_syntax_error, |
3544 | LOG_MAIN|LOG_REJECT, "unqualified recipient rejected: " | |
3545 | "<%s> %s%s", recipient, host_and_ident(TRUE), | |
3546 | host_lookup_msg); | |
3547 | break; | |
3548 | } | |
3549 | } | |
3550 | ||
3551 | /* Check maximum allowed */ | |
3552 | ||
3553 | if (rcpt_count > recipients_max && recipients_max > 0) | |
3554 | { | |
3555 | if (recipients_max_reject) | |
3556 | { | |
3557 | rcpt_fail_count++; | |
3558 | smtp_printf("552 too many recipients\r\n"); | |
3559 | if (!toomany) | |
3560 | log_write(0, LOG_MAIN|LOG_REJECT, "too many recipients: message " | |
3561 | "rejected: sender=<%s> %s", sender_address, host_and_ident(TRUE)); | |
3562 | } | |
3563 | else | |
3564 | { | |
3565 | rcpt_defer_count++; | |
3566 | smtp_printf("452 too many recipients\r\n"); | |
3567 | if (!toomany) | |
3568 | log_write(0, LOG_MAIN|LOG_REJECT, "too many recipients: excess " | |
3569 | "temporarily rejected: sender=<%s> %s", sender_address, | |
3570 | host_and_ident(TRUE)); | |
3571 | } | |
3572 | ||
3573 | toomany = TRUE; | |
3574 | break; | |
3575 | } | |
3576 | ||
3577 | /* If we have passed the threshold for rate limiting, apply the current | |
3578 | delay, and update it for next time, provided this is a limited host. */ | |
3579 | ||
3580 | if (rcpt_count > smtp_rlr_threshold && | |
3581 | verify_check_host(&smtp_ratelimit_hosts) == OK) | |
3582 | { | |
3583 | DEBUG(D_receive) debug_printf("rate limit RCPT: delay %.3g sec\n", | |
3584 | smtp_delay_rcpt/1000.0); | |
3585 | millisleep((int)smtp_delay_rcpt); | |
3586 | smtp_delay_rcpt *= smtp_rlr_factor; | |
3587 | if (smtp_delay_rcpt > (double)smtp_rlr_limit) | |
3588 | smtp_delay_rcpt = (double)smtp_rlr_limit; | |
3589 | } | |
3590 | ||
3591 | /* If the MAIL ACL discarded all the recipients, we bypass ACL checking | |
a14e5636 PH |
3592 | for them. Otherwise, check the access control list for this recipient. As |
3593 | there may be a delay in this, re-check for a synchronization error | |
3594 | afterwards, unless pipelining was advertised. */ | |
059ec3d9 | 3595 | |
a14e5636 PH |
3596 | if (recipients_discarded) rc = DISCARD; else |
3597 | { | |
3598 | rc = acl_check(ACL_WHERE_RCPT, recipient, acl_smtp_rcpt, &user_msg, | |
3599 | &log_msg); | |
3600 | if (rc == OK && !pipelining_advertised && !check_sync()) | |
3601 | goto SYNC_FAILURE; | |
3602 | } | |
059ec3d9 PH |
3603 | |
3604 | /* The ACL was happy */ | |
3605 | ||
3606 | if (rc == OK) | |
3607 | { | |
4e88a19f PH |
3608 | if (user_msg == NULL) smtp_printf("250 Accepted\r\n"); |
3609 | else smtp_user_msg(US"250", user_msg); | |
059ec3d9 PH |
3610 | receive_add_recipient(recipient, -1); |
3611 | } | |
3612 | ||
3613 | /* The recipient was discarded */ | |
3614 | ||
3615 | else if (rc == DISCARD) | |
3616 | { | |
4e88a19f PH |
3617 | if (user_msg == NULL) smtp_printf("250 Accepted\r\n"); |
3618 | else smtp_user_msg(US"250", user_msg); | |
059ec3d9 PH |
3619 | rcpt_fail_count++; |
3620 | discarded = TRUE; | |
3621 | log_write(0, LOG_MAIN|LOG_REJECT, "%s F=<%s> rejected RCPT %s: " | |
3622 | "discarded by %s ACL%s%s", host_and_ident(TRUE), | |
3623 | (sender_address_unrewritten != NULL)? | |
3624 | sender_address_unrewritten : sender_address, | |
3ee512ff | 3625 | smtp_cmd_argument, recipients_discarded? "MAIL" : "RCPT", |
059ec3d9 PH |
3626 | (log_msg == NULL)? US"" : US": ", |
3627 | (log_msg == NULL)? US"" : log_msg); | |
3628 | } | |
3629 | ||
3630 | /* Either the ACL failed the address, or it was deferred. */ | |
3631 | ||
3632 | else | |
3633 | { | |
3634 | if (rc == FAIL) rcpt_fail_count++; else rcpt_defer_count++; | |
3635 | done = smtp_handle_acl_fail(ACL_WHERE_RCPT, rc, user_msg, log_msg); | |
3636 | } | |
3637 | break; | |
3638 | ||
3639 | ||
3640 | /* The DATA command is legal only if it follows successful MAIL FROM | |
3641 | and RCPT TO commands. However, if pipelining is advertised, a bad DATA is | |
3642 | not counted as a protocol error if it follows RCPT (which must have been | |
3643 | rejected if there are no recipients.) This function is complete when a | |
3644 | valid DATA command is encountered. | |
3645 | ||
3646 | Note concerning the code used: RFC 2821 says this: | |
3647 | ||
3648 | - If there was no MAIL, or no RCPT, command, or all such commands | |
3649 | were rejected, the server MAY return a "command out of sequence" | |
3650 | (503) or "no valid recipients" (554) reply in response to the | |
3651 | DATA command. | |
3652 | ||
3653 | The example in the pipelining RFC 2920 uses 554, but I use 503 here | |
2679d413 PH |
3654 | because it is the same whether pipelining is in use or not. |
3655 | ||
3656 | If all the RCPT commands that precede DATA provoked the same error message | |
3657 | (often indicating some kind of system error), it is helpful to include it | |
3658 | with the DATA rejection (an idea suggested by Tony Finch). */ | |
059ec3d9 PH |
3659 | |
3660 | case DATA_CMD: | |
b4ed4da0 | 3661 | HAD(SCH_DATA); |
059ec3d9 PH |
3662 | if (!discarded && recipients_count <= 0) |
3663 | { | |
2679d413 PH |
3664 | if (rcpt_smtp_response_same && rcpt_smtp_response != NULL) |
3665 | { | |
3666 | uschar *code = US"503"; | |
3667 | int len = Ustrlen(rcpt_smtp_response); | |
3668 | smtp_respond(code, 3, FALSE, US"All RCPT commands were rejected with " | |
3669 | "this error:"); | |
3670 | /* Responses from smtp_printf() will have \r\n on the end */ | |
3671 | if (len > 2 && rcpt_smtp_response[len-2] == '\r') | |
3672 | rcpt_smtp_response[len-2] = 0; | |
3673 | smtp_respond(code, 3, FALSE, rcpt_smtp_response); | |
3674 | } | |
059ec3d9 | 3675 | if (pipelining_advertised && last_was_rcpt) |
2679d413 | 3676 | smtp_printf("503 Valid RCPT command must precede DATA\r\n"); |
059ec3d9 PH |
3677 | else |
3678 | done = synprot_error(L_smtp_protocol_error, 503, NULL, | |
3679 | US"valid RCPT command must precede DATA"); | |
3680 | break; | |
3681 | } | |
3682 | ||
3683 | if (toomany && recipients_max_reject) | |
3684 | { | |
3685 | sender_address = NULL; /* This will allow a new MAIL without RSET */ | |
3686 | sender_address_unrewritten = NULL; | |
3687 | smtp_printf("554 Too many recipients\r\n"); | |
3688 | break; | |
3689 | } | |
8e669ac1 | 3690 | |
a14e5636 PH |
3691 | /* If there is an ACL, re-check the synchronization afterwards, since the |
3692 | ACL may have delayed. */ | |
3693 | ||
5be20824 | 3694 | if (acl_smtp_predata == NULL) rc = OK; else |
8e669ac1 | 3695 | { |
5be20824 | 3696 | enable_dollar_recipients = TRUE; |
8e669ac1 | 3697 | rc = acl_check(ACL_WHERE_PREDATA, NULL, acl_smtp_predata, &user_msg, |
5be20824 PH |
3698 | &log_msg); |
3699 | enable_dollar_recipients = FALSE; | |
a14e5636 | 3700 | if (rc == OK && !check_sync()) goto SYNC_FAILURE; |
5be20824 | 3701 | } |
059ec3d9 PH |
3702 | |
3703 | if (rc == OK) | |
3704 | { | |
4e88a19f PH |
3705 | if (user_msg == NULL) |
3706 | smtp_printf("354 Enter message, ending with \".\" on a line by itself\r\n"); | |
3707 | else smtp_user_msg(US"354", user_msg); | |
059ec3d9 PH |
3708 | done = 3; |
3709 | message_ended = END_NOTENDED; /* Indicate in middle of data */ | |
3710 | } | |
3711 | ||
3712 | /* Either the ACL failed the address, or it was deferred. */ | |
3713 | ||
3714 | else | |
3715 | done = smtp_handle_acl_fail(ACL_WHERE_PREDATA, rc, user_msg, log_msg); | |
059ec3d9 PH |
3716 | break; |
3717 | ||
3718 | ||
3719 | case VRFY_CMD: | |
b4ed4da0 | 3720 | HAD(SCH_VRFY); |
64ffc24f | 3721 | rc = acl_check(ACL_WHERE_VRFY, NULL, acl_smtp_vrfy, &user_msg, &log_msg); |
059ec3d9 PH |
3722 | if (rc != OK) |
3723 | done = smtp_handle_acl_fail(ACL_WHERE_VRFY, rc, user_msg, log_msg); | |
3724 | else | |
3725 | { | |
3726 | uschar *address; | |
3727 | uschar *s = NULL; | |
3728 | ||
3729 | /* rfc821_domains = TRUE; << no longer needed */ | |
ca86f471 | 3730 | address = parse_extract_address(smtp_cmd_data, &errmess, &start, &end, |
059ec3d9 PH |
3731 | &recipient_domain, FALSE); |
3732 | /* rfc821_domains = FALSE; << no longer needed */ | |
3733 | ||
3734 | if (address == NULL) | |
3735 | s = string_sprintf("501 %s", errmess); | |
3736 | else | |
3737 | { | |
3738 | address_item *addr = deliver_make_addr(address, FALSE); | |
3739 | switch(verify_address(addr, NULL, vopt_is_recipient | vopt_qualify, -1, | |
4deaf07d | 3740 | -1, -1, NULL, NULL, NULL)) |
059ec3d9 PH |
3741 | { |
3742 | case OK: | |
3743 | s = string_sprintf("250 <%s> is deliverable", address); | |
3744 | break; | |
3745 | ||
3746 | case DEFER: | |
81e509d7 PH |
3747 | s = (addr->user_message != NULL)? |
3748 | string_sprintf("451 <%s> %s", address, addr->user_message) : | |
059ec3d9 PH |
3749 | string_sprintf("451 Cannot resolve <%s> at this time", address); |
3750 | break; | |
3751 | ||
3752 | case FAIL: | |
81e509d7 PH |
3753 | s = (addr->user_message != NULL)? |
3754 | string_sprintf("550 <%s> %s", address, addr->user_message) : | |
059ec3d9 PH |
3755 | string_sprintf("550 <%s> is not deliverable", address); |
3756 | log_write(0, LOG_MAIN, "VRFY failed for %s %s", | |
3ee512ff | 3757 | smtp_cmd_argument, host_and_ident(TRUE)); |
059ec3d9 PH |
3758 | break; |
3759 | } | |
3760 | } | |
3761 | ||
3762 | smtp_printf("%s\r\n", s); | |
3763 | } | |
3764 | break; | |
3765 | ||
3766 | ||
3767 | case EXPN_CMD: | |
b4ed4da0 | 3768 | HAD(SCH_EXPN); |
64ffc24f | 3769 | rc = acl_check(ACL_WHERE_EXPN, NULL, acl_smtp_expn, &user_msg, &log_msg); |
059ec3d9 PH |
3770 | if (rc != OK) |
3771 | done = smtp_handle_acl_fail(ACL_WHERE_EXPN, rc, user_msg, log_msg); | |
3772 | else | |
3773 | { | |
3774 | BOOL save_log_testing_mode = log_testing_mode; | |
3775 | address_test_mode = log_testing_mode = TRUE; | |
ca86f471 | 3776 | (void) verify_address(deliver_make_addr(smtp_cmd_data, FALSE), |
64ffc24f PH |
3777 | smtp_out, vopt_is_recipient | vopt_qualify | vopt_expn, -1, -1, -1, |
3778 | NULL, NULL, NULL); | |
059ec3d9 PH |
3779 | address_test_mode = FALSE; |
3780 | log_testing_mode = save_log_testing_mode; /* true for -bh */ | |
3781 | } | |
3782 | break; | |
3783 | ||
3784 | ||
3785 | #ifdef SUPPORT_TLS | |
3786 | ||
3787 | case STARTTLS_CMD: | |
b4ed4da0 | 3788 | HAD(SCH_STARTTLS); |
059ec3d9 PH |
3789 | if (!tls_advertised) |
3790 | { | |
3791 | done = synprot_error(L_smtp_protocol_error, 503, NULL, | |
3792 | US"STARTTLS command used when not advertised"); | |
3793 | break; | |
3794 | } | |
3795 | ||
3796 | /* Apply an ACL check if one is defined */ | |
3797 | ||
3798 | if (acl_smtp_starttls != NULL) | |
3799 | { | |
3800 | rc = acl_check(ACL_WHERE_STARTTLS, NULL, acl_smtp_starttls, &user_msg, | |
3801 | &log_msg); | |
3802 | if (rc != OK) | |
3803 | { | |
3804 | done = smtp_handle_acl_fail(ACL_WHERE_STARTTLS, rc, user_msg, log_msg); | |
3805 | break; | |
3806 | } | |
3807 | } | |
3808 | ||
3809 | /* RFC 2487 is not clear on when this command may be sent, though it | |
3810 | does state that all information previously obtained from the client | |
3811 | must be discarded if a TLS session is started. It seems reasonble to | |
3812 | do an implied RSET when STARTTLS is received. */ | |
3813 | ||
3814 | incomplete_transaction_log(US"STARTTLS"); | |
3815 | smtp_reset(reset_point); | |
3816 | toomany = FALSE; | |
3817 | cmd_list[CMD_LIST_STARTTLS].is_mail_cmd = FALSE; | |
3818 | ||
3819 | /* Attempt to start up a TLS session, and if successful, discard all | |
3820 | knowledge that was obtained previously. At least, that's what the RFC says, | |
3821 | and that's what happens by default. However, in order to work round YAEB, | |
3822 | there is an option to remember the esmtp state. Sigh. | |
3823 | ||
3824 | We must allow for an extra EHLO command and an extra AUTH command after | |
3825 | STARTTLS that don't add to the nonmail command count. */ | |
3826 | ||
83da1223 PH |
3827 | if ((rc = tls_server_start(tls_require_ciphers, gnutls_require_mac, |
3828 | gnutls_require_kx, gnutls_require_proto)) == OK) | |
059ec3d9 PH |
3829 | { |
3830 | if (!tls_remember_esmtp) | |
3831 | helo_seen = esmtp = auth_advertised = pipelining_advertised = FALSE; | |
3832 | cmd_list[CMD_LIST_EHLO].is_mail_cmd = TRUE; | |
3833 | cmd_list[CMD_LIST_AUTH].is_mail_cmd = TRUE; | |
3834 | if (sender_helo_name != NULL) | |
3835 | { | |
3836 | store_free(sender_helo_name); | |
3837 | sender_helo_name = NULL; | |
3838 | host_build_sender_fullhost(); /* Rebuild */ | |
3839 | set_process_info("handling incoming TLS connection from %s", | |
3840 | host_and_ident(FALSE)); | |
3841 | } | |
3842 | received_protocol = (esmtp? | |
3843 | protocols[pextend + pcrpted + | |
3844 | ((sender_host_authenticated != NULL)? pauthed : 0)] | |
3845 | : | |
981756db | 3846 | protocols[pnormal + pcrpted]) |
059ec3d9 PH |
3847 | + |
3848 | ((sender_host_address != NULL)? pnlocal : 0); | |
3849 | ||
3850 | sender_host_authenticated = NULL; | |
3851 | authenticated_id = NULL; | |
3852 | sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING; | |
3853 | DEBUG(D_tls) debug_printf("TLS active\n"); | |
3854 | break; /* Successful STARTTLS */ | |
3855 | } | |
3856 | ||
3857 | /* Some local configuration problem was discovered before actually trying | |
3858 | to do a TLS handshake; give a temporary error. */ | |
3859 | ||
3860 | else if (rc == DEFER) | |
3861 | { | |
3862 | smtp_printf("454 TLS currently unavailable\r\n"); | |
3863 | break; | |
3864 | } | |
3865 | ||
3866 | /* Hard failure. Reject everything except QUIT or closed connection. One | |
3867 | cause for failure is a nested STARTTLS, in which case tls_active remains | |
3868 | set, but we must still reject all incoming commands. */ | |
3869 | ||
3870 | DEBUG(D_tls) debug_printf("TLS failed to start\n"); | |
3871 | while (done <= 0) | |
3872 | { | |
3873 | switch(smtp_read_command(FALSE)) | |
3874 | { | |
3875 | case EOF_CMD: | |
3876 | log_write(L_smtp_connection, LOG_MAIN, "%s closed by EOF", | |
3877 | smtp_get_connection_info()); | |
8f128379 | 3878 | smtp_notquit_exit(US"tls-failed", NULL, NULL); |
059ec3d9 PH |
3879 | done = 2; |
3880 | break; | |
3881 | ||
8f128379 PH |
3882 | /* It is perhaps arguable as to which exit ACL should be called here, |
3883 | but as it is probably a situtation that almost never arises, it | |
3884 | probably doesn't matter. We choose to call the real QUIT ACL, which in | |
3885 | some sense is perhaps "right". */ | |
3886 | ||
059ec3d9 | 3887 | case QUIT_CMD: |
8f128379 PH |
3888 | user_msg = NULL; |
3889 | if (acl_smtp_quit != NULL) | |
3890 | { | |
3891 | rc = acl_check(ACL_WHERE_QUIT, NULL, acl_smtp_quit, &user_msg, | |
3892 | &log_msg); | |
3893 | if (rc == ERROR) | |
3894 | log_write(0, LOG_MAIN|LOG_PANIC, "ACL for QUIT returned ERROR: %s", | |
3895 | log_msg); | |
3896 | } | |
3897 | if (user_msg == NULL) | |
3898 | smtp_printf("221 %s closing connection\r\n", smtp_active_hostname); | |
3899 | else | |
3900 | smtp_respond(US"221", 3, TRUE, user_msg); | |
059ec3d9 PH |
3901 | log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT", |
3902 | smtp_get_connection_info()); | |
3903 | done = 2; | |
3904 | break; | |
3905 | ||
3906 | default: | |
3907 | smtp_printf("554 Security failure\r\n"); | |
3908 | break; | |
3909 | } | |
3910 | } | |
3911 | tls_close(TRUE); | |
3912 | break; | |
3913 | #endif | |
3914 | ||
3915 | ||
3916 | /* The ACL for QUIT is provided for gathering statistical information or | |
3917 | similar; it does not affect the response code, but it can supply a custom | |
3918 | message. */ | |
3919 | ||
3920 | case QUIT_CMD: | |
b4ed4da0 | 3921 | HAD(SCH_QUIT); |
059ec3d9 | 3922 | incomplete_transaction_log(US"QUIT"); |
059ec3d9 PH |
3923 | if (acl_smtp_quit != NULL) |
3924 | { | |
8f128379 | 3925 | rc = acl_check(ACL_WHERE_QUIT, NULL, acl_smtp_quit, &user_msg, &log_msg); |
059ec3d9 PH |
3926 | if (rc == ERROR) |
3927 | log_write(0, LOG_MAIN|LOG_PANIC, "ACL for QUIT returned ERROR: %s", | |
3928 | log_msg); | |
3929 | } | |
059ec3d9 PH |
3930 | if (user_msg == NULL) |
3931 | smtp_printf("221 %s closing connection\r\n", smtp_active_hostname); | |
3932 | else | |
4e88a19f | 3933 | smtp_respond(US"221", 3, TRUE, user_msg); |
059ec3d9 PH |
3934 | |
3935 | #ifdef SUPPORT_TLS | |
3936 | tls_close(TRUE); | |
3937 | #endif | |
3938 | ||
3939 | done = 2; | |
3940 | log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT", | |
3941 | smtp_get_connection_info()); | |
3942 | break; | |
3943 | ||
3944 | ||
3945 | case RSET_CMD: | |
b4ed4da0 | 3946 | HAD(SCH_RSET); |
059ec3d9 PH |
3947 | incomplete_transaction_log(US"RSET"); |
3948 | smtp_reset(reset_point); | |
3949 | toomany = FALSE; | |
3950 | smtp_printf("250 Reset OK\r\n"); | |
3951 | cmd_list[CMD_LIST_RSET].is_mail_cmd = FALSE; | |
3952 | break; | |
3953 | ||
3954 | ||
3955 | case NOOP_CMD: | |
b4ed4da0 | 3956 | HAD(SCH_NOOP); |
059ec3d9 PH |
3957 | smtp_printf("250 OK\r\n"); |
3958 | break; | |
3959 | ||
3960 | ||
b43a74ea PH |
3961 | /* Show ETRN/EXPN/VRFY if there's an ACL for checking hosts; if actually |
3962 | used, a check will be done for permitted hosts. Show STARTTLS only if not | |
3963 | already in a TLS session and if it would be advertised in the EHLO | |
3964 | response. */ | |
059ec3d9 PH |
3965 | |
3966 | case HELP_CMD: | |
b4ed4da0 | 3967 | HAD(SCH_HELP); |
059ec3d9 PH |
3968 | smtp_printf("214-Commands supported:\r\n"); |
3969 | { | |
3970 | uschar buffer[256]; | |
3971 | buffer[0] = 0; | |
3972 | Ustrcat(buffer, " AUTH"); | |
3973 | #ifdef SUPPORT_TLS | |
b43a74ea PH |
3974 | if (tls_active < 0 && |
3975 | verify_check_host(&tls_advertise_hosts) != FAIL) | |
3976 | Ustrcat(buffer, " STARTTLS"); | |
059ec3d9 PH |
3977 | #endif |
3978 | Ustrcat(buffer, " HELO EHLO MAIL RCPT DATA"); | |
3979 | Ustrcat(buffer, " NOOP QUIT RSET HELP"); | |
3980 | if (acl_smtp_etrn != NULL) Ustrcat(buffer, " ETRN"); | |
3981 | if (acl_smtp_expn != NULL) Ustrcat(buffer, " EXPN"); | |
3982 | if (acl_smtp_vrfy != NULL) Ustrcat(buffer, " VRFY"); | |
3983 | smtp_printf("214%s\r\n", buffer); | |
3984 | } | |
3985 | break; | |
3986 | ||
3987 | ||
3988 | case EOF_CMD: | |
3989 | incomplete_transaction_log(US"connection lost"); | |
8f128379 PH |
3990 | smtp_notquit_exit(US"connection-lost", US"421", |
3991 | US"%s lost input connection", smtp_active_hostname); | |
059ec3d9 PH |
3992 | |
3993 | /* Don't log by default unless in the middle of a message, as some mailers | |
3994 | just drop the call rather than sending QUIT, and it clutters up the logs. | |
3995 | */ | |
3996 | ||
3997 | if (sender_address != NULL || recipients_count > 0) | |
3998 | log_write(L_lost_incoming_connection, | |
3999 | LOG_MAIN, | |
4000 | "unexpected %s while reading SMTP command from %s%s", | |
4001 | sender_host_unknown? "EOF" : "disconnection", | |
4002 | host_and_ident(FALSE), smtp_read_error); | |
4003 | ||
4004 | else log_write(L_smtp_connection, LOG_MAIN, "%s lost%s", | |
4005 | smtp_get_connection_info(), smtp_read_error); | |
4006 | ||
4007 | done = 1; | |
4008 | break; | |
4009 | ||
4010 | ||
4011 | case ETRN_CMD: | |
b4ed4da0 | 4012 | HAD(SCH_ETRN); |
059ec3d9 PH |
4013 | if (sender_address != NULL) |
4014 | { | |
4015 | done = synprot_error(L_smtp_protocol_error, 503, NULL, | |
4016 | US"ETRN is not permitted inside a transaction"); | |
4017 | break; | |
4018 | } | |
4019 | ||
3ee512ff | 4020 | log_write(L_etrn, LOG_MAIN, "ETRN %s received from %s", smtp_cmd_argument, |
059ec3d9 PH |
4021 | host_and_ident(FALSE)); |
4022 | ||
64ffc24f | 4023 | rc = acl_check(ACL_WHERE_ETRN, NULL, acl_smtp_etrn, &user_msg, &log_msg); |
059ec3d9 PH |
4024 | if (rc != OK) |
4025 | { | |
4026 | done = smtp_handle_acl_fail(ACL_WHERE_ETRN, rc, user_msg, log_msg); | |
4027 | break; | |
4028 | } | |
4029 | ||
4030 | /* Compute the serialization key for this command. */ | |
4031 | ||
ca86f471 | 4032 | etrn_serialize_key = string_sprintf("etrn-%s\n", smtp_cmd_data); |
059ec3d9 PH |
4033 | |
4034 | /* If a command has been specified for running as a result of ETRN, we | |
4035 | permit any argument to ETRN. If not, only the # standard form is permitted, | |
4036 | since that is strictly the only kind of ETRN that can be implemented | |
4037 | according to the RFC. */ | |
4038 | ||
4039 | if (smtp_etrn_command != NULL) | |
4040 | { | |
4041 | uschar *error; | |
4042 | BOOL rc; | |
4043 | etrn_command = smtp_etrn_command; | |
ca86f471 | 4044 | deliver_domain = smtp_cmd_data; |
059ec3d9 PH |
4045 | rc = transport_set_up_command(&argv, smtp_etrn_command, TRUE, 0, NULL, |
4046 | US"ETRN processing", &error); | |
4047 | deliver_domain = NULL; | |
4048 | if (!rc) | |
4049 | { | |
4050 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to set up ETRN command: %s", | |
4051 | error); | |
4052 | smtp_printf("458 Internal failure\r\n"); | |
4053 | break; | |
4054 | } | |
4055 | } | |
4056 | ||
4057 | /* Else set up to call Exim with the -R option. */ | |
4058 | ||
4059 | else | |
4060 | { | |
ca86f471 | 4061 | if (*smtp_cmd_data++ != '#') |
059ec3d9 PH |
4062 | { |
4063 | done = synprot_error(L_smtp_syntax_error, 501, NULL, | |
4064 | US"argument must begin with #"); | |
4065 | break; | |
4066 | } | |
4067 | etrn_command = US"exim -R"; | |
4068 | argv = child_exec_exim(CEE_RETURN_ARGV, TRUE, NULL, TRUE, 2, US"-R", | |
ca86f471 | 4069 | smtp_cmd_data); |
059ec3d9 PH |
4070 | } |
4071 | ||
4072 | /* If we are host-testing, don't actually do anything. */ | |
4073 | ||
4074 | if (host_checking) | |
4075 | { | |
4076 | HDEBUG(D_any) | |
4077 | { | |
4078 | debug_printf("ETRN command is: %s\n", etrn_command); | |
4079 | debug_printf("ETRN command execution skipped\n"); | |
4080 | } | |
4e88a19f PH |
4081 | if (user_msg == NULL) smtp_printf("250 OK\r\n"); |
4082 | else smtp_user_msg(US"250", user_msg); | |
059ec3d9 PH |
4083 | break; |
4084 | } | |
4085 | ||
4086 | ||
4087 | /* If ETRN queue runs are to be serialized, check the database to | |
4088 | ensure one isn't already running. */ | |
4089 | ||
4090 | if (smtp_etrn_serialize && !enq_start(etrn_serialize_key)) | |
4091 | { | |
ca86f471 | 4092 | smtp_printf("458 Already processing %s\r\n", smtp_cmd_data); |
059ec3d9 PH |
4093 | break; |
4094 | } | |
4095 | ||
4096 | /* Fork a child process and run the command. We don't want to have to | |
4097 | wait for the process at any point, so set SIGCHLD to SIG_IGN before | |
4098 | forking. It should be set that way anyway for external incoming SMTP, | |
4099 | but we save and restore to be tidy. If serialization is required, we | |
4100 | actually run the command in yet another process, so we can wait for it | |
4101 | to complete and then remove the serialization lock. */ | |
4102 | ||
4103 | oldsignal = signal(SIGCHLD, SIG_IGN); | |
4104 | ||
4105 | if ((pid = fork()) == 0) | |
4106 | { | |
f1e894f3 PH |
4107 | smtp_input = FALSE; /* This process is not associated with the */ |
4108 | (void)fclose(smtp_in); /* SMTP call any more. */ | |
4109 | (void)fclose(smtp_out); | |
059ec3d9 PH |
4110 | |
4111 | signal(SIGCHLD, SIG_DFL); /* Want to catch child */ | |
4112 | ||
4113 | /* If not serializing, do the exec right away. Otherwise, fork down | |
4114 | into another process. */ | |
4115 | ||
4116 | if (!smtp_etrn_serialize || (pid = fork()) == 0) | |
4117 | { | |
4118 | DEBUG(D_exec) debug_print_argv(argv); | |
4119 | exim_nullstd(); /* Ensure std{in,out,err} exist */ | |
4120 | execv(CS argv[0], (char *const *)argv); | |
4121 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "exec of \"%s\" (ETRN) failed: %s", | |
4122 | etrn_command, strerror(errno)); | |
4123 | _exit(EXIT_FAILURE); /* paranoia */ | |
4124 | } | |
4125 | ||
4126 | /* Obey this if smtp_serialize and the 2nd fork yielded non-zero. That | |
4127 | is, we are in the first subprocess, after forking again. All we can do | |
4128 | for a failing fork is to log it. Otherwise, wait for the 2nd process to | |
4129 | complete, before removing the serialization. */ | |
4130 | ||
4131 | if (pid < 0) | |
4132 | log_write(0, LOG_MAIN|LOG_PANIC, "2nd fork for serialized ETRN " | |
4133 | "failed: %s", strerror(errno)); | |
4134 | else | |
4135 | { | |
4136 | int status; | |
4137 | DEBUG(D_any) debug_printf("waiting for serialized ETRN process %d\n", | |
4138 | (int)pid); | |
4139 | (void)wait(&status); | |
4140 | DEBUG(D_any) debug_printf("serialized ETRN process %d ended\n", | |
4141 | (int)pid); | |
4142 | } | |
4143 | ||
4144 | enq_end(etrn_serialize_key); | |
4145 | _exit(EXIT_SUCCESS); | |
4146 | } | |
4147 | ||
4148 | /* Back in the top level SMTP process. Check that we started a subprocess | |
4149 | and restore the signal state. */ | |
4150 | ||
4151 | if (pid < 0) | |
4152 | { | |
4153 | log_write(0, LOG_MAIN|LOG_PANIC, "fork of process for ETRN failed: %s", | |
4154 | strerror(errno)); | |
4155 | smtp_printf("458 Unable to fork process\r\n"); | |
4156 | if (smtp_etrn_serialize) enq_end(etrn_serialize_key); | |
4157 | } | |
4e88a19f PH |
4158 | else |
4159 | { | |
4160 | if (user_msg == NULL) smtp_printf("250 OK\r\n"); | |
4161 | else smtp_user_msg(US"250", user_msg); | |
4162 | } | |
059ec3d9 PH |
4163 | |
4164 | signal(SIGCHLD, oldsignal); | |
4165 | break; | |
4166 | ||
4167 | ||
4168 | case BADARG_CMD: | |
4169 | done = synprot_error(L_smtp_syntax_error, 501, NULL, | |
4170 | US"unexpected argument data"); | |
4171 | break; | |
4172 | ||
4173 | ||
4174 | /* This currently happens only for NULLs, but could be extended. */ | |
4175 | ||
4176 | case BADCHAR_CMD: | |
4177 | done = synprot_error(L_smtp_syntax_error, 0, NULL, /* Just logs */ | |
4178 | US"NULL character(s) present (shown as '?')"); | |
4179 | smtp_printf("501 NULL characters are not allowed in SMTP commands\r\n"); | |
4180 | break; | |
4181 | ||
4182 | ||
4183 | case BADSYN_CMD: | |
a14e5636 | 4184 | SYNC_FAILURE: |
059ec3d9 PH |
4185 | if (smtp_inend >= smtp_inbuffer + in_buffer_size) |
4186 | smtp_inend = smtp_inbuffer + in_buffer_size - 1; | |
4187 | c = smtp_inend - smtp_inptr; | |
4188 | if (c > 150) c = 150; | |
4189 | smtp_inptr[c] = 0; | |
4190 | incomplete_transaction_log(US"sync failure"); | |
3af76a81 | 4191 | log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol synchronization error " |
059ec3d9 PH |
4192 | "(next input sent too soon: pipelining was%s advertised): " |
4193 | "rejected \"%s\" %s next input=\"%s\"", | |
4194 | pipelining_advertised? "" : " not", | |
3ee512ff | 4195 | smtp_cmd_buffer, host_and_ident(TRUE), |
059ec3d9 | 4196 | string_printing(smtp_inptr)); |
8f128379 PH |
4197 | smtp_notquit_exit(US"synchronization-error", US"554", |
4198 | US"SMTP synchronization error"); | |
059ec3d9 PH |
4199 | done = 1; /* Pretend eof - drops connection */ |
4200 | break; | |
4201 | ||
4202 | ||
4203 | case TOO_MANY_NONMAIL_CMD: | |
ca86f471 PH |
4204 | s = smtp_cmd_buffer; |
4205 | while (*s != 0 && !isspace(*s)) s++; | |
059ec3d9 PH |
4206 | incomplete_transaction_log(US"too many non-mail commands"); |
4207 | log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many " | |
4208 | "nonmail commands (last was \"%.*s\")", host_and_ident(FALSE), | |
ca86f471 | 4209 | s - smtp_cmd_buffer, smtp_cmd_buffer); |
8f128379 | 4210 | smtp_notquit_exit(US"bad-commands", US"554", US"Too many nonmail commands"); |
059ec3d9 PH |
4211 | done = 1; /* Pretend eof - drops connection */ |
4212 | break; | |
4213 | ||
4214 | ||
4215 | default: | |
4216 | if (unknown_command_count++ >= smtp_max_unknown_commands) | |
4217 | { | |
4218 | log_write(L_smtp_syntax_error, LOG_MAIN, | |
4219 | "SMTP syntax error in \"%s\" %s %s", | |
3ee512ff | 4220 | string_printing(smtp_cmd_buffer), host_and_ident(TRUE), |
059ec3d9 PH |
4221 | US"unrecognized command"); |
4222 | incomplete_transaction_log(US"unrecognized command"); | |
8f128379 PH |
4223 | smtp_notquit_exit(US"bad-commands", US"500", |
4224 | US"Too many unrecognized commands"); | |
059ec3d9 PH |
4225 | done = 2; |
4226 | log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many " | |
4227 | "unrecognized commands (last was \"%s\")", host_and_ident(FALSE), | |
3ee512ff | 4228 | smtp_cmd_buffer); |
059ec3d9 PH |
4229 | } |
4230 | else | |
4231 | done = synprot_error(L_smtp_syntax_error, 500, NULL, | |
4232 | US"unrecognized command"); | |
4233 | break; | |
4234 | } | |
4235 | ||
4236 | /* This label is used by goto's inside loops that want to break out to | |
4237 | the end of the command-processing loop. */ | |
4238 | ||
4239 | COMMAND_LOOP: | |
4240 | last_was_rej_mail = was_rej_mail; /* Remember some last commands for */ | |
4241 | last_was_rcpt = was_rcpt; /* protocol error handling */ | |
4242 | continue; | |
4243 | } | |
4244 | ||
4245 | return done - 2; /* Convert yield values */ | |
4246 | } | |
4247 | ||
4248 | /* End of smtp_in.c */ |