Commit | Line | Data |
---|---|---|
059ec3d9 PH |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
5a66c31b | 5 | /* Copyright (c) University of Cambridge 1995 - 2014 */ |
059ec3d9 PH |
6 | /* See the file NOTICE for conditions of use and distribution. */ |
7 | ||
8 | /* Functions for handling an incoming SMTP call. */ | |
9 | ||
10 | ||
11 | #include "exim.h" | |
12 | ||
13 | ||
14 | /* Initialize for TCP wrappers if so configured. It appears that the macro | |
15 | HAVE_IPV6 is used in some versions of the tcpd.h header, so we unset it before | |
16 | including that header, and restore its value afterwards. */ | |
17 | ||
18 | #ifdef USE_TCP_WRAPPERS | |
19 | ||
20 | #if HAVE_IPV6 | |
21 | #define EXIM_HAVE_IPV6 | |
22 | #endif | |
23 | #undef HAVE_IPV6 | |
24 | #include <tcpd.h> | |
25 | #undef HAVE_IPV6 | |
26 | #ifdef EXIM_HAVE_IPV6 | |
27 | #define HAVE_IPV6 TRUE | |
28 | #endif | |
29 | ||
30 | int allow_severity = LOG_INFO; | |
31 | int deny_severity = LOG_NOTICE; | |
5dc43717 | 32 | uschar *tcp_wrappers_name; |
059ec3d9 PH |
33 | #endif |
34 | ||
35 | ||
8d67ada3 PH |
36 | /* Size of buffer for reading SMTP commands. We used to use 512, as defined |
37 | by RFC 821. However, RFC 1869 specifies that this must be increased for SMTP | |
38 | commands that accept arguments, and this in particular applies to AUTH, where | |
e2ca7082 PP |
39 | the data can be quite long. More recently this value was 2048 in Exim; |
40 | however, RFC 4954 (circa 2007) recommends 12288 bytes to handle AUTH. Clients | |
41 | such as Thunderbird will send an AUTH with an initial-response for GSSAPI. | |
42 | The maximum size of a Kerberos ticket under Windows 2003 is 12000 bytes, and | |
43 | we need room to handle large base64-encoded AUTHs for GSSAPI. | |
44 | */ | |
45 | ||
46 | #define smtp_cmd_buffer_size 16384 | |
059ec3d9 PH |
47 | |
48 | /* Size of buffer for reading SMTP incoming packets */ | |
49 | ||
50 | #define in_buffer_size 8192 | |
51 | ||
52 | /* Structure for SMTP command list */ | |
53 | ||
54 | typedef struct { | |
1ba28e2b | 55 | const char *name; |
059ec3d9 PH |
56 | int len; |
57 | short int cmd; | |
58 | short int has_arg; | |
59 | short int is_mail_cmd; | |
60 | } smtp_cmd_list; | |
61 | ||
62 | /* Codes for identifying commands. We order them so that those that come first | |
63 | are those for which synchronization is always required. Checking this can help | |
64 | block some spam. */ | |
65 | ||
66 | enum { | |
67 | /* These commands are required to be synchronized, i.e. to be the last in a | |
68 | block of commands when pipelining. */ | |
69 | ||
70 | HELO_CMD, EHLO_CMD, DATA_CMD, /* These are listed in the pipelining */ | |
71 | VRFY_CMD, EXPN_CMD, NOOP_CMD, /* RFC as requiring synchronization */ | |
72 | ETRN_CMD, /* This by analogy with TURN from the RFC */ | |
73 | STARTTLS_CMD, /* Required by the STARTTLS RFC */ | |
74 | ||
75 | /* This is a dummy to identify the non-sync commands when pipelining */ | |
76 | ||
77 | NON_SYNC_CMD_PIPELINING, | |
78 | ||
79 | /* These commands need not be synchronized when pipelining */ | |
80 | ||
81 | MAIL_CMD, RCPT_CMD, RSET_CMD, | |
82 | ||
83 | /* This is a dummy to identify the non-sync commands when not pipelining */ | |
84 | ||
85 | NON_SYNC_CMD_NON_PIPELINING, | |
86 | ||
87 | /* I have been unable to find a statement about the use of pipelining | |
88 | with AUTH, so to be on the safe side it is here, though I kind of feel | |
89 | it should be up there with the synchronized commands. */ | |
90 | ||
91 | AUTH_CMD, | |
92 | ||
93 | /* I'm not sure about these, but I don't think they matter. */ | |
94 | ||
95 | QUIT_CMD, HELP_CMD, | |
96 | ||
a3c86431 TL |
97 | #ifdef EXPERIMENTAL_PROXY |
98 | PROXY_FAIL_IGNORE_CMD, | |
99 | #endif | |
100 | ||
059ec3d9 PH |
101 | /* These are specials that don't correspond to actual commands */ |
102 | ||
103 | EOF_CMD, OTHER_CMD, BADARG_CMD, BADCHAR_CMD, BADSYN_CMD, | |
104 | TOO_MANY_NONMAIL_CMD }; | |
105 | ||
106 | ||
b4ed4da0 PH |
107 | /* This is a convenience macro for adding the identity of an SMTP command |
108 | to the circular buffer that holds a list of the last n received. */ | |
109 | ||
110 | #define HAD(n) \ | |
111 | smtp_connection_had[smtp_ch_index++] = n; \ | |
112 | if (smtp_ch_index >= SMTP_HBUFF_SIZE) smtp_ch_index = 0 | |
113 | ||
059ec3d9 PH |
114 | |
115 | /************************************************* | |
116 | * Local static variables * | |
117 | *************************************************/ | |
118 | ||
119 | static auth_instance *authenticated_by; | |
120 | static BOOL auth_advertised; | |
121 | #ifdef SUPPORT_TLS | |
122 | static BOOL tls_advertised; | |
123 | #endif | |
124 | static BOOL esmtp; | |
125 | static BOOL helo_required = FALSE; | |
126 | static BOOL helo_verify = FALSE; | |
127 | static BOOL helo_seen; | |
128 | static BOOL helo_accept_junk; | |
129 | static BOOL count_nonmail; | |
130 | static BOOL pipelining_advertised; | |
2679d413 PH |
131 | static BOOL rcpt_smtp_response_same; |
132 | static BOOL rcpt_in_progress; | |
059ec3d9 | 133 | static int nonmail_command_count; |
8f128379 | 134 | static BOOL smtp_exit_function_called = 0; |
059ec3d9 PH |
135 | static int synprot_error_count; |
136 | static int unknown_command_count; | |
137 | static int sync_cmd_limit; | |
138 | static int smtp_write_error = 0; | |
139 | ||
2679d413 | 140 | static uschar *rcpt_smtp_response; |
ca86f471 PH |
141 | static uschar *smtp_data_buffer; |
142 | static uschar *smtp_cmd_data; | |
143 | ||
059ec3d9 PH |
144 | /* We need to know the position of RSET, HELO, EHLO, AUTH, and STARTTLS. Their |
145 | final fields of all except AUTH are forced TRUE at the start of a new message | |
146 | setup, to allow one of each between messages that is not counted as a nonmail | |
147 | command. (In fact, only one of HELO/EHLO is not counted.) Also, we have to | |
148 | allow a new EHLO after starting up TLS. | |
149 | ||
150 | AUTH is "falsely" labelled as a mail command initially, so that it doesn't get | |
151 | counted. However, the flag is changed when AUTH is received, so that multiple | |
152 | failing AUTHs will eventually hit the limit. After a successful AUTH, another | |
153 | AUTH is already forbidden. After a TLS session is started, AUTH's flag is again | |
154 | forced TRUE, to allow for the re-authentication that can happen at that point. | |
155 | ||
156 | QUIT is also "falsely" labelled as a mail command so that it doesn't up the | |
157 | count of non-mail commands and possibly provoke an error. */ | |
158 | ||
159 | static smtp_cmd_list cmd_list[] = { | |
160 | { "rset", sizeof("rset")-1, RSET_CMD, FALSE, FALSE }, /* First */ | |
161 | { "helo", sizeof("helo")-1, HELO_CMD, TRUE, FALSE }, | |
162 | { "ehlo", sizeof("ehlo")-1, EHLO_CMD, TRUE, FALSE }, | |
163 | { "auth", sizeof("auth")-1, AUTH_CMD, TRUE, TRUE }, | |
164 | #ifdef SUPPORT_TLS | |
165 | { "starttls", sizeof("starttls")-1, STARTTLS_CMD, FALSE, FALSE }, | |
166 | #endif | |
167 | ||
168 | /* If you change anything above here, also fix the definitions below. */ | |
169 | ||
170 | { "mail from:", sizeof("mail from:")-1, MAIL_CMD, TRUE, TRUE }, | |
171 | { "rcpt to:", sizeof("rcpt to:")-1, RCPT_CMD, TRUE, TRUE }, | |
172 | { "data", sizeof("data")-1, DATA_CMD, FALSE, TRUE }, | |
173 | { "quit", sizeof("quit")-1, QUIT_CMD, FALSE, TRUE }, | |
174 | { "noop", sizeof("noop")-1, NOOP_CMD, TRUE, FALSE }, | |
175 | { "etrn", sizeof("etrn")-1, ETRN_CMD, TRUE, FALSE }, | |
176 | { "vrfy", sizeof("vrfy")-1, VRFY_CMD, TRUE, FALSE }, | |
177 | { "expn", sizeof("expn")-1, EXPN_CMD, TRUE, FALSE }, | |
178 | { "help", sizeof("help")-1, HELP_CMD, TRUE, FALSE } | |
179 | }; | |
180 | ||
181 | static smtp_cmd_list *cmd_list_end = | |
182 | cmd_list + sizeof(cmd_list)/sizeof(smtp_cmd_list); | |
183 | ||
184 | #define CMD_LIST_RSET 0 | |
185 | #define CMD_LIST_HELO 1 | |
186 | #define CMD_LIST_EHLO 2 | |
187 | #define CMD_LIST_AUTH 3 | |
188 | #define CMD_LIST_STARTTLS 4 | |
189 | ||
b4ed4da0 PH |
190 | /* This list of names is used for performing the smtp_no_mail logging action. |
191 | It must be kept in step with the SCH_xxx enumerations. */ | |
192 | ||
193 | static uschar *smtp_names[] = | |
194 | { | |
195 | US"NONE", US"AUTH", US"DATA", US"EHLO", US"ETRN", US"EXPN", US"HELO", | |
196 | US"HELP", US"MAIL", US"NOOP", US"QUIT", US"RCPT", US"RSET", US"STARTTLS", | |
197 | US"VRFY" }; | |
198 | ||
059ec3d9 | 199 | static uschar *protocols[] = { |
981756db PH |
200 | US"local-smtp", /* HELO */ |
201 | US"local-smtps", /* The rare case EHLO->STARTTLS->HELO */ | |
202 | US"local-esmtp", /* EHLO */ | |
203 | US"local-esmtps", /* EHLO->STARTTLS->EHLO */ | |
204 | US"local-esmtpa", /* EHLO->AUTH */ | |
205 | US"local-esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */ | |
059ec3d9 PH |
206 | }; |
207 | ||
208 | #define pnormal 0 | |
981756db PH |
209 | #define pextend 2 |
210 | #define pcrpted 1 /* added to pextend or pnormal */ | |
211 | #define pauthed 2 /* added to pextend */ | |
059ec3d9 PH |
212 | #define pnlocal 6 /* offset to remove "local" */ |
213 | ||
d27f98fe TL |
214 | /* Sanity check and validate optional args to MAIL FROM: envelope */ |
215 | enum { | |
216 | ENV_MAIL_OPT_SIZE, ENV_MAIL_OPT_BODY, ENV_MAIL_OPT_AUTH, | |
fd98a5c6 JH |
217 | #ifdef EXPERIMENTAL_PRDR |
218 | ENV_MAIL_OPT_PRDR, | |
219 | #endif | |
220 | ENV_MAIL_OPT_NULL | |
d27f98fe TL |
221 | }; |
222 | typedef struct { | |
223 | uschar * name; /* option requested during MAIL cmd */ | |
224 | int value; /* enum type */ | |
225 | BOOL need_value; /* TRUE requires value (name=value pair format) | |
226 | FALSE is a singleton */ | |
227 | } env_mail_type_t; | |
228 | static env_mail_type_t env_mail_type_list[] = { | |
229 | { US"SIZE", ENV_MAIL_OPT_SIZE, TRUE }, | |
230 | { US"BODY", ENV_MAIL_OPT_BODY, TRUE }, | |
231 | { US"AUTH", ENV_MAIL_OPT_AUTH, TRUE }, | |
fd98a5c6 JH |
232 | #ifdef EXPERIMENTAL_PRDR |
233 | { US"PRDR", ENV_MAIL_OPT_PRDR, FALSE }, | |
234 | #endif | |
235 | { US"NULL", ENV_MAIL_OPT_NULL, FALSE } | |
d27f98fe TL |
236 | }; |
237 | ||
059ec3d9 PH |
238 | /* When reading SMTP from a remote host, we have to use our own versions of the |
239 | C input-reading functions, in order to be able to flush the SMTP output only | |
240 | when about to read more data from the socket. This is the only way to get | |
241 | optimal performance when the client is using pipelining. Flushing for every | |
242 | command causes a separate packet and reply packet each time; saving all the | |
243 | responses up (when pipelining) combines them into one packet and one response. | |
244 | ||
245 | For simplicity, these functions are used for *all* SMTP input, not only when | |
246 | receiving over a socket. However, after setting up a secure socket (SSL), input | |
247 | is read via the OpenSSL library, and another set of functions is used instead | |
248 | (see tls.c). | |
249 | ||
250 | These functions are set in the receive_getc etc. variables and called with the | |
251 | same interface as the C functions. However, since there can only ever be | |
252 | one incoming SMTP call, we just use a single buffer and flags. There is no need | |
253 | to implement a complicated private FILE-like structure.*/ | |
254 | ||
255 | static uschar *smtp_inbuffer; | |
256 | static uschar *smtp_inptr; | |
257 | static uschar *smtp_inend; | |
258 | static int smtp_had_eof; | |
259 | static int smtp_had_error; | |
260 | ||
261 | ||
262 | /************************************************* | |
263 | * SMTP version of getc() * | |
264 | *************************************************/ | |
265 | ||
266 | /* This gets the next byte from the SMTP input buffer. If the buffer is empty, | |
267 | it flushes the output, and refills the buffer, with a timeout. The signal | |
268 | handler is set appropriately by the calling function. This function is not used | |
269 | after a connection has negotated itself into an TLS/SSL state. | |
270 | ||
271 | Arguments: none | |
272 | Returns: the next character or EOF | |
273 | */ | |
274 | ||
275 | int | |
276 | smtp_getc(void) | |
277 | { | |
278 | if (smtp_inptr >= smtp_inend) | |
279 | { | |
280 | int rc, save_errno; | |
281 | fflush(smtp_out); | |
282 | if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); | |
283 | rc = read(fileno(smtp_in), smtp_inbuffer, in_buffer_size); | |
284 | save_errno = errno; | |
285 | alarm(0); | |
286 | if (rc <= 0) | |
287 | { | |
288 | /* Must put the error text in fixed store, because this might be during | |
289 | header reading, where it releases unused store above the header. */ | |
290 | if (rc < 0) | |
291 | { | |
292 | smtp_had_error = save_errno; | |
293 | smtp_read_error = string_copy_malloc( | |
294 | string_sprintf(" (error: %s)", strerror(save_errno))); | |
295 | } | |
296 | else smtp_had_eof = 1; | |
297 | return EOF; | |
298 | } | |
80a47a2c TK |
299 | #ifndef DISABLE_DKIM |
300 | dkim_exim_verify_feed(smtp_inbuffer, rc); | |
301 | #endif | |
059ec3d9 PH |
302 | smtp_inend = smtp_inbuffer + rc; |
303 | smtp_inptr = smtp_inbuffer; | |
304 | } | |
305 | return *smtp_inptr++; | |
306 | } | |
307 | ||
308 | ||
309 | ||
310 | /************************************************* | |
311 | * SMTP version of ungetc() * | |
312 | *************************************************/ | |
313 | ||
314 | /* Puts a character back in the input buffer. Only ever | |
315 | called once. | |
316 | ||
317 | Arguments: | |
318 | ch the character | |
319 | ||
320 | Returns: the character | |
321 | */ | |
322 | ||
323 | int | |
324 | smtp_ungetc(int ch) | |
325 | { | |
326 | *(--smtp_inptr) = ch; | |
327 | return ch; | |
328 | } | |
329 | ||
330 | ||
331 | ||
332 | ||
333 | /************************************************* | |
334 | * SMTP version of feof() * | |
335 | *************************************************/ | |
336 | ||
337 | /* Tests for a previous EOF | |
338 | ||
339 | Arguments: none | |
340 | Returns: non-zero if the eof flag is set | |
341 | */ | |
342 | ||
343 | int | |
344 | smtp_feof(void) | |
345 | { | |
346 | return smtp_had_eof; | |
347 | } | |
348 | ||
349 | ||
350 | ||
351 | ||
352 | /************************************************* | |
353 | * SMTP version of ferror() * | |
354 | *************************************************/ | |
355 | ||
356 | /* Tests for a previous read error, and returns with errno | |
357 | restored to what it was when the error was detected. | |
358 | ||
359 | Arguments: none | |
360 | Returns: non-zero if the error flag is set | |
361 | */ | |
362 | ||
363 | int | |
364 | smtp_ferror(void) | |
365 | { | |
366 | errno = smtp_had_error; | |
367 | return smtp_had_error; | |
368 | } | |
369 | ||
370 | ||
371 | ||
58eb016e PH |
372 | /************************************************* |
373 | * Test for characters in the SMTP buffer * | |
374 | *************************************************/ | |
375 | ||
376 | /* Used at the end of a message | |
377 | ||
378 | Arguments: none | |
379 | Returns: TRUE/FALSE | |
380 | */ | |
381 | ||
382 | BOOL | |
383 | smtp_buffered(void) | |
384 | { | |
385 | return smtp_inptr < smtp_inend; | |
386 | } | |
387 | ||
388 | ||
059ec3d9 PH |
389 | |
390 | /************************************************* | |
391 | * Write formatted string to SMTP channel * | |
392 | *************************************************/ | |
393 | ||
394 | /* This is a separate function so that we don't have to repeat everything for | |
395 | TLS support or debugging. It is global so that the daemon and the | |
396 | authentication functions can use it. It does not return any error indication, | |
397 | because major problems such as dropped connections won't show up till an output | |
398 | flush for non-TLS connections. The smtp_fflush() function is available for | |
399 | checking that: for convenience, TLS output errors are remembered here so that | |
400 | they are also picked up later by smtp_fflush(). | |
401 | ||
402 | Arguments: | |
403 | format format string | |
404 | ... optional arguments | |
405 | ||
406 | Returns: nothing | |
407 | */ | |
408 | ||
409 | void | |
1ba28e2b | 410 | smtp_printf(const char *format, ...) |
059ec3d9 PH |
411 | { |
412 | va_list ap; | |
413 | ||
ce552449 NM |
414 | va_start(ap, format); |
415 | smtp_vprintf(format, ap); | |
416 | va_end(ap); | |
417 | } | |
418 | ||
419 | /* This is split off so that verify.c:respond_printf() can, in effect, call | |
420 | smtp_printf(), bearing in mind that in C a vararg function can't directly | |
fb08281f | 421 | call another vararg function, only a function which accepts a va_list. */ |
ce552449 NM |
422 | |
423 | void | |
1ba28e2b | 424 | smtp_vprintf(const char *format, va_list ap) |
ce552449 | 425 | { |
fb08281f DW |
426 | BOOL yield; |
427 | ||
428 | yield = string_vformat(big_buffer, big_buffer_size, format, ap); | |
ce552449 | 429 | |
059ec3d9 PH |
430 | DEBUG(D_receive) |
431 | { | |
fb08281f DW |
432 | void *reset_point = store_get(0); |
433 | uschar *msg_copy, *cr, *end; | |
434 | msg_copy = string_copy(big_buffer); | |
435 | end = msg_copy + Ustrlen(msg_copy); | |
436 | while ((cr = Ustrchr(msg_copy, '\r')) != NULL) /* lose CRs */ | |
437 | memmove(cr, cr + 1, (end--) - cr); | |
438 | debug_printf("SMTP>> %s", msg_copy); | |
439 | store_reset(reset_point); | |
059ec3d9 PH |
440 | } |
441 | ||
fb08281f | 442 | if (!yield) |
2679d413 PH |
443 | { |
444 | log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_printf()"); | |
445 | smtp_closedown(US"Unexpected error"); | |
446 | exim_exit(EXIT_FAILURE); | |
447 | } | |
2679d413 PH |
448 | |
449 | /* If this is the first output for a (non-batch) RCPT command, see if all RCPTs | |
450 | have had the same. Note: this code is also present in smtp_respond(). It would | |
451 | be tidier to have it only in one place, but when it was added, it was easier to | |
452 | do it that way, so as not to have to mess with the code for the RCPT command, | |
453 | which sometimes uses smtp_printf() and sometimes smtp_respond(). */ | |
454 | ||
455 | if (rcpt_in_progress) | |
456 | { | |
457 | if (rcpt_smtp_response == NULL) | |
458 | rcpt_smtp_response = string_copy(big_buffer); | |
459 | else if (rcpt_smtp_response_same && | |
460 | Ustrcmp(rcpt_smtp_response, big_buffer) != 0) | |
461 | rcpt_smtp_response_same = FALSE; | |
462 | rcpt_in_progress = FALSE; | |
463 | } | |
059ec3d9 | 464 | |
2679d413 | 465 | /* Now write the string */ |
059ec3d9 PH |
466 | |
467 | #ifdef SUPPORT_TLS | |
817d9f57 | 468 | if (tls_in.active >= 0) |
059ec3d9 | 469 | { |
817d9f57 JH |
470 | if (tls_write(TRUE, big_buffer, Ustrlen(big_buffer)) < 0) |
471 | smtp_write_error = -1; | |
059ec3d9 PH |
472 | } |
473 | else | |
474 | #endif | |
475 | ||
2679d413 | 476 | if (fprintf(smtp_out, "%s", big_buffer) < 0) smtp_write_error = -1; |
059ec3d9 PH |
477 | } |
478 | ||
479 | ||
480 | ||
481 | /************************************************* | |
482 | * Flush SMTP out and check for error * | |
483 | *************************************************/ | |
484 | ||
485 | /* This function isn't currently used within Exim (it detects errors when it | |
486 | tries to read the next SMTP input), but is available for use in local_scan(). | |
487 | For non-TLS connections, it flushes the output and checks for errors. For | |
488 | TLS-connections, it checks for a previously-detected TLS write error. | |
489 | ||
490 | Arguments: none | |
491 | Returns: 0 for no error; -1 after an error | |
492 | */ | |
493 | ||
494 | int | |
495 | smtp_fflush(void) | |
496 | { | |
817d9f57 | 497 | if (tls_in.active < 0 && fflush(smtp_out) != 0) smtp_write_error = -1; |
059ec3d9 PH |
498 | return smtp_write_error; |
499 | } | |
500 | ||
501 | ||
502 | ||
503 | /************************************************* | |
504 | * SMTP command read timeout * | |
505 | *************************************************/ | |
506 | ||
507 | /* Signal handler for timing out incoming SMTP commands. This attempts to | |
508 | finish off tidily. | |
509 | ||
510 | Argument: signal number (SIGALRM) | |
511 | Returns: nothing | |
512 | */ | |
513 | ||
514 | static void | |
515 | command_timeout_handler(int sig) | |
516 | { | |
517 | sig = sig; /* Keep picky compilers happy */ | |
518 | log_write(L_lost_incoming_connection, | |
519 | LOG_MAIN, "SMTP command timeout on%s connection from %s", | |
817d9f57 | 520 | (tls_in.active >= 0)? " TLS" : "", |
059ec3d9 PH |
521 | host_and_ident(FALSE)); |
522 | if (smtp_batched_input) | |
523 | moan_smtp_batch(NULL, "421 SMTP command timeout"); /* Does not return */ | |
8f128379 PH |
524 | smtp_notquit_exit(US"command-timeout", US"421", |
525 | US"%s: SMTP command timeout - closing connection", smtp_active_hostname); | |
059ec3d9 PH |
526 | exim_exit(EXIT_FAILURE); |
527 | } | |
528 | ||
529 | ||
530 | ||
531 | /************************************************* | |
532 | * SIGTERM received * | |
533 | *************************************************/ | |
534 | ||
535 | /* Signal handler for handling SIGTERM. Again, try to finish tidily. | |
536 | ||
537 | Argument: signal number (SIGTERM) | |
538 | Returns: nothing | |
539 | */ | |
540 | ||
541 | static void | |
542 | command_sigterm_handler(int sig) | |
543 | { | |
544 | sig = sig; /* Keep picky compilers happy */ | |
545 | log_write(0, LOG_MAIN, "%s closed after SIGTERM", smtp_get_connection_info()); | |
546 | if (smtp_batched_input) | |
547 | moan_smtp_batch(NULL, "421 SIGTERM received"); /* Does not return */ | |
8f128379 PH |
548 | smtp_notquit_exit(US"signal-exit", US"421", |
549 | US"%s: Service not available - closing connection", smtp_active_hostname); | |
059ec3d9 PH |
550 | exim_exit(EXIT_FAILURE); |
551 | } | |
552 | ||
553 | ||
554 | ||
a14e5636 | 555 | |
a3c86431 | 556 | #ifdef EXPERIMENTAL_PROXY |
a3bddaa8 TL |
557 | /************************************************* |
558 | * Restore socket timeout to previous value * | |
559 | *************************************************/ | |
560 | /* If the previous value was successfully retrieved, restore | |
561 | it before returning control to the non-proxy routines | |
562 | ||
563 | Arguments: fd - File descriptor for input | |
564 | get_ok - Successfully retrieved previous values | |
565 | tvtmp - Time struct with previous values | |
566 | vslen - Length of time struct | |
567 | Returns: none | |
568 | */ | |
569 | static void | |
570 | restore_socket_timeout(int fd, int get_ok, struct timeval tvtmp, socklen_t vslen) | |
571 | { | |
572 | if (get_ok == 0) | |
573 | setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, (char *)&tvtmp, vslen); | |
574 | } | |
575 | ||
a3c86431 TL |
576 | /************************************************* |
577 | * Check if host is required proxy host * | |
578 | *************************************************/ | |
579 | /* The function determines if inbound host will be a regular smtp host | |
580 | or if it is configured that it must use Proxy Protocol. | |
581 | ||
582 | Arguments: none | |
583 | Returns: bool | |
584 | */ | |
585 | ||
586 | static BOOL | |
587 | check_proxy_protocol_host() | |
588 | { | |
589 | int rc; | |
590 | /* Cannot configure local connection as a proxy inbound */ | |
591 | if (sender_host_address == NULL) return proxy_session; | |
592 | ||
593 | rc = verify_check_this_host(&proxy_required_hosts, NULL, NULL, | |
594 | sender_host_address, NULL); | |
595 | if (rc == OK) | |
596 | { | |
597 | DEBUG(D_receive) | |
598 | debug_printf("Detected proxy protocol configured host\n"); | |
599 | proxy_session = TRUE; | |
600 | } | |
601 | return proxy_session; | |
602 | } | |
603 | ||
604 | ||
a3c86431 TL |
605 | /************************************************* |
606 | * Setup host for proxy protocol * | |
607 | *************************************************/ | |
608 | /* The function configures the connection based on a header from the | |
609 | inbound host to use Proxy Protocol. The specification is very exact | |
610 | so exit with an error if do not find the exact required pieces. This | |
611 | includes an incorrect number of spaces separating args. | |
612 | ||
613 | Arguments: none | |
614 | Returns: int | |
615 | */ | |
616 | ||
617 | static BOOL | |
618 | setup_proxy_protocol_host() | |
619 | { | |
620 | union { | |
621 | struct { | |
622 | uschar line[108]; | |
623 | } v1; | |
624 | struct { | |
625 | uschar sig[12]; | |
626 | uschar ver; | |
627 | uschar cmd; | |
628 | uschar fam; | |
629 | uschar len; | |
630 | union { | |
631 | struct { /* TCP/UDP over IPv4, len = 12 */ | |
632 | uint32_t src_addr; | |
633 | uint32_t dst_addr; | |
634 | uint16_t src_port; | |
635 | uint16_t dst_port; | |
636 | } ip4; | |
637 | struct { /* TCP/UDP over IPv6, len = 36 */ | |
638 | uint8_t src_addr[16]; | |
639 | uint8_t dst_addr[16]; | |
640 | uint16_t src_port; | |
641 | uint16_t dst_port; | |
642 | } ip6; | |
643 | struct { /* AF_UNIX sockets, len = 216 */ | |
644 | uschar src_addr[108]; | |
645 | uschar dst_addr[108]; | |
646 | } unx; | |
647 | } addr; | |
648 | } v2; | |
649 | } hdr; | |
650 | ||
eb57651e TL |
651 | /* Temp variables used in PPv2 address:port parsing */ |
652 | uint16_t tmpport; | |
653 | char tmpip[INET_ADDRSTRLEN]; | |
654 | struct sockaddr_in tmpaddr; | |
655 | char tmpip6[INET6_ADDRSTRLEN]; | |
656 | struct sockaddr_in6 tmpaddr6; | |
657 | ||
658 | int get_ok = 0; | |
a3c86431 | 659 | int size, ret, fd; |
a3c86431 TL |
660 | const char v2sig[13] = "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A\x02"; |
661 | uschar *iptype; /* To display debug info */ | |
662 | struct timeval tv; | |
a3bddaa8 TL |
663 | socklen_t vslen = 0; |
664 | struct timeval tvtmp; | |
665 | ||
666 | vslen = sizeof(struct timeval); | |
a3c86431 TL |
667 | |
668 | fd = fileno(smtp_in); | |
669 | ||
a3bddaa8 TL |
670 | /* Save current socket timeout values */ |
671 | get_ok = getsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, (char *)&tvtmp, | |
672 | &vslen); | |
673 | ||
a3c86431 TL |
674 | /* Proxy Protocol host must send header within a short time |
675 | (default 3 seconds) or it's considered invalid */ | |
676 | tv.tv_sec = PROXY_NEGOTIATION_TIMEOUT_SEC; | |
677 | tv.tv_usec = PROXY_NEGOTIATION_TIMEOUT_USEC; | |
678 | setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, (char *)&tv, | |
679 | sizeof(struct timeval)); | |
a3bddaa8 | 680 | |
a3c86431 TL |
681 | do |
682 | { | |
eb57651e TL |
683 | /* The inbound host was declared to be a Proxy Protocol host, so |
684 | don't do a PEEK into the data, actually slurp it up. */ | |
685 | ret = recv(fd, &hdr, sizeof(hdr), 0); | |
a3c86431 TL |
686 | } |
687 | while (ret == -1 && errno == EINTR); | |
688 | ||
689 | if (ret == -1) | |
a3bddaa8 TL |
690 | { |
691 | restore_socket_timeout(fd, get_ok, tvtmp, vslen); | |
a3c86431 | 692 | return (errno == EAGAIN) ? 0 : ERRNO_PROXYFAIL; |
a3bddaa8 | 693 | } |
a3c86431 TL |
694 | |
695 | if (ret >= 16 && | |
696 | memcmp(&hdr.v2, v2sig, 13) == 0) | |
697 | { | |
698 | DEBUG(D_receive) debug_printf("Detected PROXYv2 header\n"); | |
699 | size = 16 + hdr.v2.len; | |
700 | if (ret < size) | |
701 | { | |
702 | DEBUG(D_receive) debug_printf("Truncated or too large PROXYv2 header\n"); | |
703 | goto proxyfail; | |
704 | } | |
705 | switch (hdr.v2.cmd) | |
706 | { | |
707 | case 0x01: /* PROXY command */ | |
708 | switch (hdr.v2.fam) | |
709 | { | |
eb57651e TL |
710 | case 0x11: /* TCPv4 address type */ |
711 | iptype = US"IPv4"; | |
712 | tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.src_addr; | |
713 | inet_ntop(AF_INET, &(tmpaddr.sin_addr), (char *)&tmpip, sizeof(tmpip)); | |
714 | if (!string_is_ip_address(US tmpip,NULL)) | |
715 | { | |
716 | DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype); | |
a3c86431 | 717 | return ERRNO_PROXYFAIL; |
eb57651e TL |
718 | } |
719 | proxy_host_address = sender_host_address; | |
720 | sender_host_address = string_copy(US tmpip); | |
721 | tmpport = ntohs(hdr.v2.addr.ip4.src_port); | |
722 | proxy_host_port = sender_host_port; | |
723 | sender_host_port = tmpport; | |
724 | /* Save dest ip/port */ | |
725 | tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.dst_addr; | |
726 | inet_ntop(AF_INET, &(tmpaddr.sin_addr), (char *)&tmpip, sizeof(tmpip)); | |
727 | if (!string_is_ip_address(US tmpip,NULL)) | |
728 | { | |
729 | DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype); | |
730 | return ERRNO_PROXYFAIL; | |
731 | } | |
732 | proxy_target_address = string_copy(US tmpip); | |
733 | tmpport = ntohs(hdr.v2.addr.ip4.dst_port); | |
734 | proxy_target_port = tmpport; | |
a3c86431 | 735 | goto done; |
eb57651e TL |
736 | case 0x21: /* TCPv6 address type */ |
737 | iptype = US"IPv6"; | |
738 | memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.src_addr, 16); | |
739 | inet_ntop(AF_INET6, &(tmpaddr6.sin6_addr), (char *)&tmpip6, sizeof(tmpip6)); | |
740 | if (!string_is_ip_address(US tmpip6,NULL)) | |
741 | { | |
742 | DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype); | |
743 | return ERRNO_PROXYFAIL; | |
744 | } | |
745 | proxy_host_address = sender_host_address; | |
746 | sender_host_address = string_copy(US tmpip6); | |
747 | tmpport = ntohs(hdr.v2.addr.ip6.src_port); | |
748 | proxy_host_port = sender_host_port; | |
749 | sender_host_port = tmpport; | |
750 | /* Save dest ip/port */ | |
751 | memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.dst_addr, 16); | |
752 | inet_ntop(AF_INET6, &(tmpaddr6.sin6_addr), (char *)&tmpip6, sizeof(tmpip6)); | |
753 | if (!string_is_ip_address(US tmpip6,NULL)) | |
754 | { | |
755 | DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype); | |
a3c86431 | 756 | return ERRNO_PROXYFAIL; |
eb57651e TL |
757 | } |
758 | proxy_target_address = string_copy(US tmpip6); | |
759 | tmpport = ntohs(hdr.v2.addr.ip6.dst_port); | |
760 | proxy_target_port = tmpport; | |
a3c86431 | 761 | goto done; |
eb57651e TL |
762 | default: |
763 | DEBUG(D_receive) | |
764 | debug_printf("Unsupported PROXYv2 connection type: 0x%02x\n", | |
765 | hdr.v2.fam); | |
766 | goto proxyfail; | |
a3c86431 TL |
767 | } |
768 | /* Unsupported protocol, keep local connection address */ | |
769 | break; | |
770 | case 0x00: /* LOCAL command */ | |
771 | /* Keep local connection address for LOCAL */ | |
772 | break; | |
773 | default: | |
eb57651e TL |
774 | DEBUG(D_receive) |
775 | debug_printf("Unsupported PROXYv2 command: 0x%02x\n", | |
776 | hdr.v2.cmd); | |
a3c86431 TL |
777 | goto proxyfail; |
778 | } | |
779 | } | |
780 | else if (ret >= 8 && | |
781 | memcmp(hdr.v1.line, "PROXY", 5) == 0) | |
782 | { | |
783 | uschar *p = string_copy(hdr.v1.line); | |
784 | uschar *end = memchr(p, '\r', ret - 1); | |
785 | uschar *sp; /* Utility variables follow */ | |
786 | int tmp_port; | |
787 | char *endc; | |
788 | ||
789 | if (!end || end[1] != '\n') | |
790 | { | |
791 | DEBUG(D_receive) debug_printf("Partial or invalid PROXY header\n"); | |
792 | goto proxyfail; | |
793 | } | |
794 | *end = '\0'; /* Terminate the string */ | |
795 | size = end + 2 - hdr.v1.line; /* Skip header + CRLF */ | |
796 | DEBUG(D_receive) debug_printf("Detected PROXYv1 header\n"); | |
797 | /* Step through the string looking for the required fields. Ensure | |
798 | strict adherance to required formatting, exit for any error. */ | |
799 | p += 5; | |
800 | if (!isspace(*(p++))) | |
801 | { | |
802 | DEBUG(D_receive) debug_printf("Missing space after PROXY command\n"); | |
803 | goto proxyfail; | |
804 | } | |
805 | if (!Ustrncmp(p, CCS"TCP4", 4)) | |
806 | iptype = US"IPv4"; | |
807 | else if (!Ustrncmp(p,CCS"TCP6", 4)) | |
808 | iptype = US"IPv6"; | |
809 | else if (!Ustrncmp(p,CCS"UNKNOWN", 7)) | |
810 | { | |
811 | iptype = US"Unknown"; | |
812 | goto done; | |
813 | } | |
814 | else | |
815 | { | |
816 | DEBUG(D_receive) debug_printf("Invalid TCP type\n"); | |
817 | goto proxyfail; | |
818 | } | |
819 | ||
820 | p += Ustrlen(iptype); | |
821 | if (!isspace(*(p++))) | |
822 | { | |
823 | DEBUG(D_receive) debug_printf("Missing space after TCP4/6 command\n"); | |
824 | goto proxyfail; | |
825 | } | |
826 | /* Find the end of the arg */ | |
827 | if ((sp = Ustrchr(p, ' ')) == NULL) | |
828 | { | |
829 | DEBUG(D_receive) | |
830 | debug_printf("Did not find proxied src %s\n", iptype); | |
831 | goto proxyfail; | |
832 | } | |
833 | *sp = '\0'; | |
834 | if(!string_is_ip_address(p,NULL)) | |
835 | { | |
836 | DEBUG(D_receive) | |
837 | debug_printf("Proxied src arg is not an %s address\n", iptype); | |
838 | goto proxyfail; | |
839 | } | |
a3bddaa8 | 840 | proxy_host_address = sender_host_address; |
a3c86431 TL |
841 | sender_host_address = p; |
842 | p = sp + 1; | |
843 | if ((sp = Ustrchr(p, ' ')) == NULL) | |
844 | { | |
845 | DEBUG(D_receive) | |
846 | debug_printf("Did not find proxy dest %s\n", iptype); | |
847 | goto proxyfail; | |
848 | } | |
849 | *sp = '\0'; | |
850 | if(!string_is_ip_address(p,NULL)) | |
851 | { | |
852 | DEBUG(D_receive) | |
853 | debug_printf("Proxy dest arg is not an %s address\n", iptype); | |
854 | goto proxyfail; | |
855 | } | |
eb57651e | 856 | proxy_target_address = p; |
a3c86431 TL |
857 | p = sp + 1; |
858 | if ((sp = Ustrchr(p, ' ')) == NULL) | |
859 | { | |
860 | DEBUG(D_receive) debug_printf("Did not find proxied src port\n"); | |
861 | goto proxyfail; | |
862 | } | |
863 | *sp = '\0'; | |
864 | tmp_port = strtol(CCS p,&endc,10); | |
865 | if (*endc || tmp_port == 0) | |
866 | { | |
867 | DEBUG(D_receive) | |
868 | debug_printf("Proxied src port '%s' not an integer\n", p); | |
869 | goto proxyfail; | |
870 | } | |
a3bddaa8 | 871 | proxy_host_port = sender_host_port; |
a3c86431 TL |
872 | sender_host_port = tmp_port; |
873 | p = sp + 1; | |
874 | if ((sp = Ustrchr(p, '\0')) == NULL) | |
875 | { | |
876 | DEBUG(D_receive) debug_printf("Did not find proxy dest port\n"); | |
877 | goto proxyfail; | |
878 | } | |
879 | tmp_port = strtol(CCS p,&endc,10); | |
880 | if (*endc || tmp_port == 0) | |
881 | { | |
882 | DEBUG(D_receive) | |
883 | debug_printf("Proxy dest port '%s' not an integer\n", p); | |
884 | goto proxyfail; | |
885 | } | |
eb57651e | 886 | proxy_target_port = tmp_port; |
a3c86431 TL |
887 | /* Already checked for /r /n above. Good V1 header received. */ |
888 | goto done; | |
889 | } | |
890 | else | |
891 | { | |
892 | /* Wrong protocol */ | |
eb57651e | 893 | DEBUG(D_receive) debug_printf("Invalid proxy protocol version negotiation\n"); |
a3c86431 TL |
894 | goto proxyfail; |
895 | } | |
896 | ||
897 | proxyfail: | |
a3bddaa8 | 898 | restore_socket_timeout(fd, get_ok, tvtmp, vslen); |
a3c86431 | 899 | /* Don't flush any potential buffer contents. Any input should cause a |
eb57651e | 900 | synchronization failure */ |
a3c86431 TL |
901 | return FALSE; |
902 | ||
903 | done: | |
a3bddaa8 | 904 | restore_socket_timeout(fd, get_ok, tvtmp, vslen); |
a3c86431 | 905 | DEBUG(D_receive) |
eb57651e | 906 | debug_printf("Valid %s sender from Proxy Protocol header\n", iptype); |
a3c86431 TL |
907 | return proxy_session; |
908 | } | |
909 | #endif | |
910 | ||
059ec3d9 PH |
911 | /************************************************* |
912 | * Read one command line * | |
913 | *************************************************/ | |
914 | ||
915 | /* Strictly, SMTP commands coming over the net are supposed to end with CRLF. | |
916 | There are sites that don't do this, and in any case internal SMTP probably | |
917 | should check only for LF. Consequently, we check here for LF only. The line | |
918 | ends up with [CR]LF removed from its end. If we get an overlong line, treat as | |
3ee512ff PH |
919 | an unknown command. The command is read into the global smtp_cmd_buffer so that |
920 | it is available via $smtp_command. | |
059ec3d9 PH |
921 | |
922 | The character reading routine sets up a timeout for each block actually read | |
923 | from the input (which may contain more than one command). We set up a special | |
924 | signal handler that closes down the session on a timeout. Control does not | |
925 | return when it runs. | |
926 | ||
927 | Arguments: | |
928 | check_sync if TRUE, check synchronization rules if global option is TRUE | |
929 | ||
930 | Returns: a code identifying the command (enumerated above) | |
931 | */ | |
932 | ||
933 | static int | |
934 | smtp_read_command(BOOL check_sync) | |
935 | { | |
936 | int c; | |
937 | int ptr = 0; | |
938 | smtp_cmd_list *p; | |
939 | BOOL hadnull = FALSE; | |
940 | ||
941 | os_non_restarting_signal(SIGALRM, command_timeout_handler); | |
942 | ||
943 | while ((c = (receive_getc)()) != '\n' && c != EOF) | |
944 | { | |
3ee512ff | 945 | if (ptr >= smtp_cmd_buffer_size) |
059ec3d9 PH |
946 | { |
947 | os_non_restarting_signal(SIGALRM, sigalrm_handler); | |
948 | return OTHER_CMD; | |
949 | } | |
950 | if (c == 0) | |
951 | { | |
952 | hadnull = TRUE; | |
953 | c = '?'; | |
954 | } | |
3ee512ff | 955 | smtp_cmd_buffer[ptr++] = c; |
059ec3d9 PH |
956 | } |
957 | ||
958 | receive_linecount++; /* For BSMTP errors */ | |
959 | os_non_restarting_signal(SIGALRM, sigalrm_handler); | |
960 | ||
961 | /* If hit end of file, return pseudo EOF command. Whether we have a | |
962 | part-line already read doesn't matter, since this is an error state. */ | |
963 | ||
964 | if (c == EOF) return EOF_CMD; | |
965 | ||
966 | /* Remove any CR and white space at the end of the line, and terminate the | |
967 | string. */ | |
968 | ||
3ee512ff PH |
969 | while (ptr > 0 && isspace(smtp_cmd_buffer[ptr-1])) ptr--; |
970 | smtp_cmd_buffer[ptr] = 0; | |
059ec3d9 | 971 | |
3ee512ff | 972 | DEBUG(D_receive) debug_printf("SMTP<< %s\n", smtp_cmd_buffer); |
059ec3d9 PH |
973 | |
974 | /* NULLs are not allowed in SMTP commands */ | |
975 | ||
976 | if (hadnull) return BADCHAR_CMD; | |
977 | ||
978 | /* Scan command list and return identity, having set the data pointer | |
979 | to the start of the actual data characters. Check for SMTP synchronization | |
980 | if required. */ | |
981 | ||
982 | for (p = cmd_list; p < cmd_list_end; p++) | |
983 | { | |
a3c86431 TL |
984 | #ifdef EXPERIMENTAL_PROXY |
985 | /* Only allow QUIT command if Proxy Protocol parsing failed */ | |
986 | if (proxy_session && proxy_session_failed) | |
987 | { | |
988 | if (p->cmd != QUIT_CMD) | |
989 | continue; | |
990 | } | |
991 | #endif | |
084efe8d PH |
992 | if (strncmpic(smtp_cmd_buffer, US p->name, p->len) == 0 && |
993 | (smtp_cmd_buffer[p->len-1] == ':' || /* "mail from:" or "rcpt to:" */ | |
994 | smtp_cmd_buffer[p->len] == 0 || | |
995 | smtp_cmd_buffer[p->len] == ' ')) | |
059ec3d9 PH |
996 | { |
997 | if (smtp_inptr < smtp_inend && /* Outstanding input */ | |
998 | p->cmd < sync_cmd_limit && /* Command should sync */ | |
999 | check_sync && /* Local flag set */ | |
1000 | smtp_enforce_sync && /* Global flag set */ | |
1001 | sender_host_address != NULL && /* Not local input */ | |
1002 | !sender_host_notsocket) /* Really is a socket */ | |
1003 | return BADSYN_CMD; | |
1004 | ||
ca86f471 PH |
1005 | /* The variables $smtp_command and $smtp_command_argument point into the |
1006 | unmodified input buffer. A copy of the latter is taken for actual | |
1007 | processing, so that it can be chopped up into separate parts if necessary, | |
1008 | for example, when processing a MAIL command options such as SIZE that can | |
1009 | follow the sender address. */ | |
059ec3d9 | 1010 | |
3ee512ff | 1011 | smtp_cmd_argument = smtp_cmd_buffer + p->len; |
ca86f471 PH |
1012 | while (isspace(*smtp_cmd_argument)) smtp_cmd_argument++; |
1013 | Ustrcpy(smtp_data_buffer, smtp_cmd_argument); | |
1014 | smtp_cmd_data = smtp_data_buffer; | |
059ec3d9 PH |
1015 | |
1016 | /* Count non-mail commands from those hosts that are controlled in this | |
1017 | way. The default is all hosts. We don't waste effort checking the list | |
1018 | until we get a non-mail command, but then cache the result to save checking | |
1019 | again. If there's a DEFER while checking the host, assume it's in the list. | |
1020 | ||
1021 | Note that one instance of RSET, EHLO/HELO, and STARTTLS is allowed at the | |
1022 | start of each incoming message by fiddling with the value in the table. */ | |
1023 | ||
1024 | if (!p->is_mail_cmd) | |
1025 | { | |
1026 | if (count_nonmail == TRUE_UNSET) count_nonmail = | |
1027 | verify_check_host(&smtp_accept_max_nonmail_hosts) != FAIL; | |
1028 | if (count_nonmail && ++nonmail_command_count > smtp_accept_max_nonmail) | |
1029 | return TOO_MANY_NONMAIL_CMD; | |
1030 | } | |
1031 | ||
ca86f471 PH |
1032 | /* If there is data for a command that does not expect it, generate the |
1033 | error here. */ | |
059ec3d9 | 1034 | |
ca86f471 | 1035 | return (p->has_arg || *smtp_cmd_data == 0)? p->cmd : BADARG_CMD; |
059ec3d9 PH |
1036 | } |
1037 | } | |
1038 | ||
a3c86431 TL |
1039 | #ifdef EXPERIMENTAL_PROXY |
1040 | /* Only allow QUIT command if Proxy Protocol parsing failed */ | |
1041 | if (proxy_session && proxy_session_failed) | |
1042 | return PROXY_FAIL_IGNORE_CMD; | |
1043 | #endif | |
1044 | ||
059ec3d9 PH |
1045 | /* Enforce synchronization for unknown commands */ |
1046 | ||
1047 | if (smtp_inptr < smtp_inend && /* Outstanding input */ | |
1048 | check_sync && /* Local flag set */ | |
1049 | smtp_enforce_sync && /* Global flag set */ | |
1050 | sender_host_address != NULL && /* Not local input */ | |
1051 | !sender_host_notsocket) /* Really is a socket */ | |
1052 | return BADSYN_CMD; | |
1053 | ||
1054 | return OTHER_CMD; | |
1055 | } | |
1056 | ||
1057 | ||
1058 | ||
a14e5636 PH |
1059 | /************************************************* |
1060 | * Recheck synchronization * | |
1061 | *************************************************/ | |
1062 | ||
1063 | /* Synchronization checks can never be perfect because a packet may be on its | |
1064 | way but not arrived when the check is done. Such checks can in any case only be | |
1065 | done when TLS is not in use. Normally, the checks happen when commands are | |
1066 | read: Exim ensures that there is no more input in the input buffer. In normal | |
1067 | cases, the response to the command will be fast, and there is no further check. | |
1068 | ||
1069 | However, for some commands an ACL is run, and that can include delays. In those | |
1070 | cases, it is useful to do another check on the input just before sending the | |
1071 | response. This also applies at the start of a connection. This function does | |
1072 | that check by means of the select() function, as long as the facility is not | |
1073 | disabled or inappropriate. A failure of select() is ignored. | |
1074 | ||
1075 | When there is unwanted input, we read it so that it appears in the log of the | |
1076 | error. | |
1077 | ||
1078 | Arguments: none | |
1079 | Returns: TRUE if all is well; FALSE if there is input pending | |
1080 | */ | |
1081 | ||
1082 | static BOOL | |
1083 | check_sync(void) | |
1084 | { | |
1085 | int fd, rc; | |
1086 | fd_set fds; | |
1087 | struct timeval tzero; | |
1088 | ||
1089 | if (!smtp_enforce_sync || sender_host_address == NULL || | |
817d9f57 | 1090 | sender_host_notsocket || tls_in.active >= 0) |
a14e5636 PH |
1091 | return TRUE; |
1092 | ||
1093 | fd = fileno(smtp_in); | |
1094 | FD_ZERO(&fds); | |
1095 | FD_SET(fd, &fds); | |
1096 | tzero.tv_sec = 0; | |
1097 | tzero.tv_usec = 0; | |
1098 | rc = select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &tzero); | |
1099 | ||
1100 | if (rc <= 0) return TRUE; /* Not ready to read */ | |
1101 | rc = smtp_getc(); | |
1102 | if (rc < 0) return TRUE; /* End of file or error */ | |
1103 | ||
1104 | smtp_ungetc(rc); | |
1105 | rc = smtp_inend - smtp_inptr; | |
1106 | if (rc > 150) rc = 150; | |
1107 | smtp_inptr[rc] = 0; | |
1108 | return FALSE; | |
1109 | } | |
1110 | ||
1111 | ||
1112 | ||
059ec3d9 PH |
1113 | /************************************************* |
1114 | * Forced closedown of call * | |
1115 | *************************************************/ | |
1116 | ||
1117 | /* This function is called from log.c when Exim is dying because of a serious | |
1118 | disaster, and also from some other places. If an incoming non-batched SMTP | |
1119 | channel is open, it swallows the rest of the incoming message if in the DATA | |
1120 | phase, sends the reply string, and gives an error to all subsequent commands | |
1121 | except QUIT. The existence of an SMTP call is detected by the non-NULLness of | |
1122 | smtp_in. | |
1123 | ||
8f128379 PH |
1124 | Arguments: |
1125 | message SMTP reply string to send, excluding the code | |
1126 | ||
059ec3d9 PH |
1127 | Returns: nothing |
1128 | */ | |
1129 | ||
1130 | void | |
1131 | smtp_closedown(uschar *message) | |
1132 | { | |
1133 | if (smtp_in == NULL || smtp_batched_input) return; | |
1134 | receive_swallow_smtp(); | |
1135 | smtp_printf("421 %s\r\n", message); | |
1136 | ||
1137 | for (;;) | |
1138 | { | |
1139 | switch(smtp_read_command(FALSE)) | |
1140 | { | |
1141 | case EOF_CMD: | |
1142 | return; | |
1143 | ||
1144 | case QUIT_CMD: | |
1145 | smtp_printf("221 %s closing connection\r\n", smtp_active_hostname); | |
1146 | mac_smtp_fflush(); | |
1147 | return; | |
1148 | ||
1149 | case RSET_CMD: | |
1150 | smtp_printf("250 Reset OK\r\n"); | |
1151 | break; | |
1152 | ||
1153 | default: | |
1154 | smtp_printf("421 %s\r\n", message); | |
1155 | break; | |
1156 | } | |
1157 | } | |
1158 | } | |
1159 | ||
1160 | ||
1161 | ||
1162 | ||
1163 | /************************************************* | |
1164 | * Set up connection info for logging * | |
1165 | *************************************************/ | |
1166 | ||
1167 | /* This function is called when logging information about an SMTP connection. | |
1168 | It sets up appropriate source information, depending on the type of connection. | |
dac79d3e PH |
1169 | If sender_fullhost is NULL, we are at a very early stage of the connection; |
1170 | just use the IP address. | |
059ec3d9 PH |
1171 | |
1172 | Argument: none | |
1173 | Returns: a string describing the connection | |
1174 | */ | |
1175 | ||
1176 | uschar * | |
1177 | smtp_get_connection_info(void) | |
1178 | { | |
dac79d3e PH |
1179 | uschar *hostname = (sender_fullhost == NULL)? |
1180 | sender_host_address : sender_fullhost; | |
1181 | ||
059ec3d9 | 1182 | if (host_checking) |
dac79d3e | 1183 | return string_sprintf("SMTP connection from %s", hostname); |
059ec3d9 PH |
1184 | |
1185 | if (sender_host_unknown || sender_host_notsocket) | |
1186 | return string_sprintf("SMTP connection from %s", sender_ident); | |
1187 | ||
1188 | if (is_inetd) | |
dac79d3e | 1189 | return string_sprintf("SMTP connection from %s (via inetd)", hostname); |
059ec3d9 PH |
1190 | |
1191 | if ((log_extra_selector & LX_incoming_interface) != 0 && | |
1192 | interface_address != NULL) | |
dac79d3e | 1193 | return string_sprintf("SMTP connection from %s I=[%s]:%d", hostname, |
059ec3d9 PH |
1194 | interface_address, interface_port); |
1195 | ||
dac79d3e | 1196 | return string_sprintf("SMTP connection from %s", hostname); |
059ec3d9 PH |
1197 | } |
1198 | ||
1199 | ||
1200 | ||
e45a1c37 | 1201 | #ifdef SUPPORT_TLS |
887291d2 JH |
1202 | /* Append TLS-related information to a log line |
1203 | ||
1204 | Arguments: | |
1205 | s String under construction: allocated string to extend, or NULL | |
1206 | sizep Pointer to current allocation size (update on return), or NULL | |
1207 | ptrp Pointer to index for new entries in string (update on return), or NULL | |
1208 | ||
1209 | Returns: Allocated string or NULL | |
1210 | */ | |
e45a1c37 JH |
1211 | static uschar * |
1212 | s_tlslog(uschar * s, int * sizep, int * ptrp) | |
1213 | { | |
1214 | int size = sizep ? *sizep : 0; | |
1215 | int ptr = ptrp ? *ptrp : 0; | |
1216 | ||
1217 | if ((log_extra_selector & LX_tls_cipher) != 0 && tls_in.cipher != NULL) | |
1218 | s = string_append(s, &size, &ptr, 2, US" X=", tls_in.cipher); | |
1219 | if ((log_extra_selector & LX_tls_certificate_verified) != 0 && | |
1220 | tls_in.cipher != NULL) | |
1221 | s = string_append(s, &size, &ptr, 2, US" CV=", | |
1222 | tls_in.certificate_verified? "yes":"no"); | |
1223 | if ((log_extra_selector & LX_tls_peerdn) != 0 && tls_in.peerdn != NULL) | |
1224 | s = string_append(s, &size, &ptr, 3, US" DN=\"", | |
1225 | string_printing(tls_in.peerdn), US"\""); | |
1226 | if ((log_extra_selector & LX_tls_sni) != 0 && tls_in.sni != NULL) | |
1227 | s = string_append(s, &size, &ptr, 3, US" SNI=\"", | |
1228 | string_printing(tls_in.sni), US"\""); | |
1229 | ||
67d81c10 JH |
1230 | if (s) |
1231 | { | |
1232 | s[ptr] = '\0'; | |
1233 | if (sizep) *sizep = size; | |
1234 | if (ptrp) *ptrp = ptr; | |
1235 | } | |
e45a1c37 JH |
1236 | return s; |
1237 | } | |
1238 | #endif | |
1239 | ||
b4ed4da0 PH |
1240 | /************************************************* |
1241 | * Log lack of MAIL if so configured * | |
1242 | *************************************************/ | |
1243 | ||
1244 | /* This function is called when an SMTP session ends. If the log selector | |
1245 | smtp_no_mail is set, write a log line giving some details of what has happened | |
1246 | in the SMTP session. | |
1247 | ||
1248 | Arguments: none | |
1249 | Returns: nothing | |
1250 | */ | |
1251 | ||
1252 | void | |
1253 | smtp_log_no_mail(void) | |
1254 | { | |
1255 | int size, ptr, i; | |
1256 | uschar *s, *sep; | |
1257 | ||
1258 | if (smtp_mailcmd_count > 0 || (log_extra_selector & LX_smtp_no_mail) == 0) | |
1259 | return; | |
1260 | ||
1261 | s = NULL; | |
1262 | size = ptr = 0; | |
1263 | ||
1264 | if (sender_host_authenticated != NULL) | |
1265 | { | |
1266 | s = string_append(s, &size, &ptr, 2, US" A=", sender_host_authenticated); | |
1267 | if (authenticated_id != NULL) | |
1268 | s = string_append(s, &size, &ptr, 2, US":", authenticated_id); | |
1269 | } | |
1270 | ||
1271 | #ifdef SUPPORT_TLS | |
e45a1c37 | 1272 | s = s_tlslog(s, &size, &ptr); |
3f0945ff | 1273 | #endif |
b4ed4da0 PH |
1274 | |
1275 | sep = (smtp_connection_had[SMTP_HBUFF_SIZE-1] != SCH_NONE)? | |
1276 | US" C=..." : US" C="; | |
1277 | for (i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++) | |
1278 | { | |
1279 | if (smtp_connection_had[i] != SCH_NONE) | |
1280 | { | |
1281 | s = string_append(s, &size, &ptr, 2, sep, | |
1282 | smtp_names[smtp_connection_had[i]]); | |
1283 | sep = US","; | |
1284 | } | |
1285 | } | |
1286 | ||
1287 | for (i = 0; i < smtp_ch_index; i++) | |
1288 | { | |
1289 | s = string_append(s, &size, &ptr, 2, sep, smtp_names[smtp_connection_had[i]]); | |
1290 | sep = US","; | |
1291 | } | |
1292 | ||
1293 | if (s != NULL) s[ptr] = 0; else s = US""; | |
1294 | log_write(0, LOG_MAIN, "no MAIL in SMTP connection from %s D=%s%s", | |
1295 | host_and_ident(FALSE), | |
1296 | readconf_printtime(time(NULL) - smtp_connection_start), s); | |
1297 | } | |
1298 | ||
1299 | ||
1300 | ||
059ec3d9 PH |
1301 | /************************************************* |
1302 | * Check HELO line and set sender_helo_name * | |
1303 | *************************************************/ | |
1304 | ||
1305 | /* Check the format of a HELO line. The data for HELO/EHLO is supposed to be | |
1306 | the domain name of the sending host, or an ip literal in square brackets. The | |
1307 | arrgument is placed in sender_helo_name, which is in malloc store, because it | |
1308 | must persist over multiple incoming messages. If helo_accept_junk is set, this | |
1309 | host is permitted to send any old junk (needed for some broken hosts). | |
1310 | Otherwise, helo_allow_chars can be used for rogue characters in general | |
1311 | (typically people want to let in underscores). | |
1312 | ||
1313 | Argument: | |
1314 | s the data portion of the line (already past any white space) | |
1315 | ||
1316 | Returns: TRUE or FALSE | |
1317 | */ | |
1318 | ||
1319 | static BOOL | |
1320 | check_helo(uschar *s) | |
1321 | { | |
1322 | uschar *start = s; | |
1323 | uschar *end = s + Ustrlen(s); | |
1324 | BOOL yield = helo_accept_junk; | |
1325 | ||
1326 | /* Discard any previous helo name */ | |
1327 | ||
1328 | if (sender_helo_name != NULL) | |
1329 | { | |
1330 | store_free(sender_helo_name); | |
1331 | sender_helo_name = NULL; | |
1332 | } | |
1333 | ||
1334 | /* Skip tests if junk is permitted. */ | |
1335 | ||
1336 | if (!yield) | |
1337 | { | |
1338 | /* Allow the new standard form for IPv6 address literals, namely, | |
1339 | [IPv6:....], and because someone is bound to use it, allow an equivalent | |
1340 | IPv4 form. Allow plain addresses as well. */ | |
1341 | ||
1342 | if (*s == '[') | |
1343 | { | |
1344 | if (end[-1] == ']') | |
1345 | { | |
1346 | end[-1] = 0; | |
1347 | if (strncmpic(s, US"[IPv6:", 6) == 0) | |
1348 | yield = (string_is_ip_address(s+6, NULL) == 6); | |
1349 | else if (strncmpic(s, US"[IPv4:", 6) == 0) | |
1350 | yield = (string_is_ip_address(s+6, NULL) == 4); | |
1351 | else | |
1352 | yield = (string_is_ip_address(s+1, NULL) != 0); | |
1353 | end[-1] = ']'; | |
1354 | } | |
1355 | } | |
1356 | ||
1357 | /* Non-literals must be alpha, dot, hyphen, plus any non-valid chars | |
1358 | that have been configured (usually underscore - sigh). */ | |
1359 | ||
1360 | else if (*s != 0) | |
1361 | { | |
1362 | yield = TRUE; | |
1363 | while (*s != 0) | |
1364 | { | |
1365 | if (!isalnum(*s) && *s != '.' && *s != '-' && | |
1366 | Ustrchr(helo_allow_chars, *s) == NULL) | |
1367 | { | |
1368 | yield = FALSE; | |
1369 | break; | |
1370 | } | |
1371 | s++; | |
1372 | } | |
1373 | } | |
1374 | } | |
1375 | ||
1376 | /* Save argument if OK */ | |
1377 | ||
1378 | if (yield) sender_helo_name = string_copy_malloc(start); | |
1379 | return yield; | |
1380 | } | |
1381 | ||
1382 | ||
1383 | ||
1384 | ||
1385 | ||
1386 | /************************************************* | |
1387 | * Extract SMTP command option * | |
1388 | *************************************************/ | |
1389 | ||
ca86f471 | 1390 | /* This function picks the next option setting off the end of smtp_cmd_data. It |
059ec3d9 PH |
1391 | is called for MAIL FROM and RCPT TO commands, to pick off the optional ESMTP |
1392 | things that can appear there. | |
1393 | ||
1394 | Arguments: | |
1395 | name point this at the name | |
1396 | value point this at the data string | |
1397 | ||
1398 | Returns: TRUE if found an option | |
1399 | */ | |
1400 | ||
1401 | static BOOL | |
1402 | extract_option(uschar **name, uschar **value) | |
1403 | { | |
1404 | uschar *n; | |
ca86f471 | 1405 | uschar *v = smtp_cmd_data + Ustrlen(smtp_cmd_data) - 1; |
059ec3d9 PH |
1406 | while (isspace(*v)) v--; |
1407 | v[1] = 0; | |
ca86f471 | 1408 | while (v > smtp_cmd_data && *v != '=' && !isspace(*v)) v--; |
059ec3d9 PH |
1409 | |
1410 | n = v; | |
fd98a5c6 JH |
1411 | if (*v == '=') |
1412 | { | |
1413 | while(isalpha(n[-1])) n--; | |
1414 | /* RFC says SP, but TAB seen in wild and other major MTAs accept it */ | |
1415 | if (!isspace(n[-1])) return FALSE; | |
1416 | n[-1] = 0; | |
1417 | } | |
1418 | else | |
1419 | { | |
1420 | n++; | |
1421 | if (v == smtp_cmd_data) return FALSE; | |
1422 | } | |
059ec3d9 | 1423 | *v++ = 0; |
fd98a5c6 | 1424 | *name = n; |
059ec3d9 PH |
1425 | *value = v; |
1426 | return TRUE; | |
1427 | } | |
1428 | ||
1429 | ||
1430 | ||
1431 | ||
1432 | ||
059ec3d9 PH |
1433 | /************************************************* |
1434 | * Reset for new message * | |
1435 | *************************************************/ | |
1436 | ||
1437 | /* This function is called whenever the SMTP session is reset from | |
1438 | within either of the setup functions. | |
1439 | ||
1440 | Argument: the stacking pool storage reset point | |
1441 | Returns: nothing | |
1442 | */ | |
1443 | ||
1444 | static void | |
1445 | smtp_reset(void *reset_point) | |
1446 | { | |
059ec3d9 PH |
1447 | store_reset(reset_point); |
1448 | recipients_list = NULL; | |
1449 | rcpt_count = rcpt_defer_count = rcpt_fail_count = | |
1450 | raw_recipients_count = recipients_count = recipients_list_max = 0; | |
2e5b33cd | 1451 | cancel_cutthrough_connection("smtp reset"); |
2e0c1448 | 1452 | message_linecount = 0; |
059ec3d9 | 1453 | message_size = -1; |
71fafd95 | 1454 | acl_added_headers = NULL; |
e7568d51 | 1455 | acl_removed_headers = NULL; |
059ec3d9 | 1456 | queue_only_policy = FALSE; |
2679d413 PH |
1457 | rcpt_smtp_response = NULL; |
1458 | rcpt_smtp_response_same = TRUE; | |
1459 | rcpt_in_progress = FALSE; | |
69358f02 | 1460 | deliver_freeze = FALSE; /* Can be set by ACL */ |
6a3f1455 | 1461 | freeze_tell = freeze_tell_config; /* Can be set by ACL */ |
29aba418 | 1462 | fake_response = OK; /* Can be set by ACL */ |
6951ac6c | 1463 | #ifdef WITH_CONTENT_SCAN |
8523533c TK |
1464 | no_mbox_unspool = FALSE; /* Can be set by ACL */ |
1465 | #endif | |
69358f02 | 1466 | submission_mode = FALSE; /* Can be set by ACL */ |
f4ee74ac | 1467 | suppress_local_fixups = suppress_local_fixups_default; /* Can be set by ACL */ |
69358f02 PH |
1468 | active_local_from_check = local_from_check; /* Can be set by ACL */ |
1469 | active_local_sender_retain = local_sender_retain; /* Can be set by ACL */ | |
059ec3d9 | 1470 | sender_address = NULL; |
2fe1a124 | 1471 | submission_name = NULL; /* Can be set by ACL */ |
059ec3d9 PH |
1472 | raw_sender = NULL; /* After SMTP rewrite, before qualifying */ |
1473 | sender_address_unrewritten = NULL; /* Set only after verify rewrite */ | |
1474 | sender_verified_list = NULL; /* No senders verified */ | |
1475 | memset(sender_address_cache, 0, sizeof(sender_address_cache)); | |
1476 | memset(sender_domain_cache, 0, sizeof(sender_domain_cache)); | |
1477 | authenticated_sender = NULL; | |
8523533c TK |
1478 | #ifdef EXPERIMENTAL_BRIGHTMAIL |
1479 | bmi_run = 0; | |
1480 | bmi_verdicts = NULL; | |
1481 | #endif | |
80a47a2c | 1482 | #ifndef DISABLE_DKIM |
9e5d6b55 | 1483 | dkim_signers = NULL; |
80a47a2c TK |
1484 | dkim_disable_verify = FALSE; |
1485 | dkim_collect_input = FALSE; | |
f7572e5a | 1486 | #endif |
8523533c TK |
1487 | #ifdef EXPERIMENTAL_SPF |
1488 | spf_header_comment = NULL; | |
1489 | spf_received = NULL; | |
8e669ac1 | 1490 | spf_result = NULL; |
8523533c TK |
1491 | spf_smtp_comment = NULL; |
1492 | #endif | |
059ec3d9 PH |
1493 | body_linecount = body_zerocount = 0; |
1494 | ||
870f6ba8 TF |
1495 | sender_rate = sender_rate_limit = sender_rate_period = NULL; |
1496 | ratelimiters_mail = NULL; /* Updated by ratelimit ACL condition */ | |
1497 | /* Note that ratelimiters_conn persists across resets. */ | |
1498 | ||
38a0a95f | 1499 | /* Reset message ACL variables */ |
47ca6d6c | 1500 | |
38a0a95f | 1501 | acl_var_m = NULL; |
059ec3d9 PH |
1502 | |
1503 | /* The message body variables use malloc store. They may be set if this is | |
1504 | not the first message in an SMTP session and the previous message caused them | |
1505 | to be referenced in an ACL. */ | |
1506 | ||
1507 | if (message_body != NULL) | |
1508 | { | |
1509 | store_free(message_body); | |
1510 | message_body = NULL; | |
1511 | } | |
1512 | ||
1513 | if (message_body_end != NULL) | |
1514 | { | |
1515 | store_free(message_body_end); | |
1516 | message_body_end = NULL; | |
1517 | } | |
1518 | ||
1519 | /* Warning log messages are also saved in malloc store. They are saved to avoid | |
1520 | repetition in the same message, but it seems right to repeat them for different | |
4e88a19f | 1521 | messages. */ |
059ec3d9 PH |
1522 | |
1523 | while (acl_warn_logged != NULL) | |
1524 | { | |
1525 | string_item *this = acl_warn_logged; | |
1526 | acl_warn_logged = acl_warn_logged->next; | |
1527 | store_free(this); | |
1528 | } | |
1529 | } | |
1530 | ||
1531 | ||
1532 | ||
1533 | ||
1534 | ||
1535 | /************************************************* | |
1536 | * Initialize for incoming batched SMTP message * | |
1537 | *************************************************/ | |
1538 | ||
1539 | /* This function is called from smtp_setup_msg() in the case when | |
1540 | smtp_batched_input is true. This happens when -bS is used to pass a whole batch | |
1541 | of messages in one file with SMTP commands between them. All errors must be | |
1542 | reported by sending a message, and only MAIL FROM, RCPT TO, and DATA are | |
1543 | relevant. After an error on a sender, or an invalid recipient, the remainder | |
1544 | of the message is skipped. The value of received_protocol is already set. | |
1545 | ||
1546 | Argument: none | |
1547 | Returns: > 0 message successfully started (reached DATA) | |
1548 | = 0 QUIT read or end of file reached | |
1549 | < 0 should not occur | |
1550 | */ | |
1551 | ||
1552 | static int | |
1553 | smtp_setup_batch_msg(void) | |
1554 | { | |
1555 | int done = 0; | |
1556 | void *reset_point = store_get(0); | |
1557 | ||
1558 | /* Save the line count at the start of each transaction - single commands | |
1559 | like HELO and RSET count as whole transactions. */ | |
1560 | ||
1561 | bsmtp_transaction_linecount = receive_linecount; | |
1562 | ||
1563 | if ((receive_feof)()) return 0; /* Treat EOF as QUIT */ | |
1564 | ||
1565 | smtp_reset(reset_point); /* Reset for start of message */ | |
1566 | ||
1567 | /* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE | |
1568 | value. The values are 2 larger than the required yield of the function. */ | |
1569 | ||
1570 | while (done <= 0) | |
1571 | { | |
1572 | uschar *errmess; | |
1573 | uschar *recipient = NULL; | |
1574 | int start, end, sender_domain, recipient_domain; | |
1575 | ||
1576 | switch(smtp_read_command(FALSE)) | |
1577 | { | |
1578 | /* The HELO/EHLO commands set sender_address_helo if they have | |
1579 | valid data; otherwise they are ignored, except that they do | |
1580 | a reset of the state. */ | |
1581 | ||
1582 | case HELO_CMD: | |
1583 | case EHLO_CMD: | |
1584 | ||
ca86f471 | 1585 | check_helo(smtp_cmd_data); |
059ec3d9 PH |
1586 | /* Fall through */ |
1587 | ||
1588 | case RSET_CMD: | |
1589 | smtp_reset(reset_point); | |
1590 | bsmtp_transaction_linecount = receive_linecount; | |
1591 | break; | |
1592 | ||
1593 | ||
1594 | /* The MAIL FROM command requires an address as an operand. All we | |
1595 | do here is to parse it for syntactic correctness. The form "<>" is | |
1596 | a special case which converts into an empty string. The start/end | |
1597 | pointers in the original are not used further for this address, as | |
1598 | it is the canonical extracted address which is all that is kept. */ | |
1599 | ||
1600 | case MAIL_CMD: | |
1601 | if (sender_address != NULL) | |
1602 | /* The function moan_smtp_batch() does not return. */ | |
3ee512ff | 1603 | moan_smtp_batch(smtp_cmd_buffer, "503 Sender already given"); |
059ec3d9 | 1604 | |
ca86f471 | 1605 | if (smtp_cmd_data[0] == 0) |
059ec3d9 | 1606 | /* The function moan_smtp_batch() does not return. */ |
3ee512ff | 1607 | moan_smtp_batch(smtp_cmd_buffer, "501 MAIL FROM must have an address operand"); |
059ec3d9 PH |
1608 | |
1609 | /* Reset to start of message */ | |
1610 | ||
1611 | smtp_reset(reset_point); | |
1612 | ||
1613 | /* Apply SMTP rewrite */ | |
1614 | ||
1615 | raw_sender = ((rewrite_existflags & rewrite_smtp) != 0)? | |
ca86f471 PH |
1616 | rewrite_one(smtp_cmd_data, rewrite_smtp|rewrite_smtp_sender, NULL, FALSE, |
1617 | US"", global_rewrite_rules) : smtp_cmd_data; | |
059ec3d9 PH |
1618 | |
1619 | /* Extract the address; the TRUE flag allows <> as valid */ | |
1620 | ||
1621 | raw_sender = | |
1622 | parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain, | |
1623 | TRUE); | |
1624 | ||
1625 | if (raw_sender == NULL) | |
1626 | /* The function moan_smtp_batch() does not return. */ | |
3ee512ff | 1627 | moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess); |
059ec3d9 PH |
1628 | |
1629 | sender_address = string_copy(raw_sender); | |
1630 | ||
1631 | /* Qualify unqualified sender addresses if permitted to do so. */ | |
1632 | ||
1633 | if (sender_domain == 0 && sender_address[0] != 0 && sender_address[0] != '@') | |
1634 | { | |
1635 | if (allow_unqualified_sender) | |
1636 | { | |
1637 | sender_address = rewrite_address_qualify(sender_address, FALSE); | |
1638 | DEBUG(D_receive) debug_printf("unqualified address %s accepted " | |
1639 | "and rewritten\n", raw_sender); | |
1640 | } | |
1641 | /* The function moan_smtp_batch() does not return. */ | |
3ee512ff | 1642 | else moan_smtp_batch(smtp_cmd_buffer, "501 sender address must contain " |
059ec3d9 PH |
1643 | "a domain"); |
1644 | } | |
1645 | break; | |
1646 | ||
1647 | ||
1648 | /* The RCPT TO command requires an address as an operand. All we do | |
1649 | here is to parse it for syntactic correctness. There may be any number | |
1650 | of RCPT TO commands, specifying multiple senders. We build them all into | |
1651 | a data structure that is in argc/argv format. The start/end values | |
1652 | given by parse_extract_address are not used, as we keep only the | |
1653 | extracted address. */ | |
1654 | ||
1655 | case RCPT_CMD: | |
1656 | if (sender_address == NULL) | |
1657 | /* The function moan_smtp_batch() does not return. */ | |
3ee512ff | 1658 | moan_smtp_batch(smtp_cmd_buffer, "503 No sender yet given"); |
059ec3d9 | 1659 | |
ca86f471 | 1660 | if (smtp_cmd_data[0] == 0) |
059ec3d9 | 1661 | /* The function moan_smtp_batch() does not return. */ |
3ee512ff | 1662 | moan_smtp_batch(smtp_cmd_buffer, "501 RCPT TO must have an address operand"); |
059ec3d9 PH |
1663 | |
1664 | /* Check maximum number allowed */ | |
1665 | ||
1666 | if (recipients_max > 0 && recipients_count + 1 > recipients_max) | |
1667 | /* The function moan_smtp_batch() does not return. */ | |
3ee512ff | 1668 | moan_smtp_batch(smtp_cmd_buffer, "%s too many recipients", |
059ec3d9 PH |
1669 | recipients_max_reject? "552": "452"); |
1670 | ||
1671 | /* Apply SMTP rewrite, then extract address. Don't allow "<>" as a | |
1672 | recipient address */ | |
1673 | ||
1674 | recipient = ((rewrite_existflags & rewrite_smtp) != 0)? | |
ca86f471 PH |
1675 | rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"", |
1676 | global_rewrite_rules) : smtp_cmd_data; | |
059ec3d9 PH |
1677 | |
1678 | /* rfc821_domains = TRUE; << no longer needed */ | |
1679 | recipient = parse_extract_address(recipient, &errmess, &start, &end, | |
1680 | &recipient_domain, FALSE); | |
1681 | /* rfc821_domains = FALSE; << no longer needed */ | |
1682 | ||
1683 | if (recipient == NULL) | |
1684 | /* The function moan_smtp_batch() does not return. */ | |
3ee512ff | 1685 | moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess); |
059ec3d9 PH |
1686 | |
1687 | /* If the recipient address is unqualified, qualify it if permitted. Then | |
1688 | add it to the list of recipients. */ | |
1689 | ||
1690 | if (recipient_domain == 0) | |
1691 | { | |
1692 | if (allow_unqualified_recipient) | |
1693 | { | |
1694 | DEBUG(D_receive) debug_printf("unqualified address %s accepted\n", | |
1695 | recipient); | |
1696 | recipient = rewrite_address_qualify(recipient, TRUE); | |
1697 | } | |
1698 | /* The function moan_smtp_batch() does not return. */ | |
3ee512ff | 1699 | else moan_smtp_batch(smtp_cmd_buffer, "501 recipient address must contain " |
059ec3d9 PH |
1700 | "a domain"); |
1701 | } | |
1702 | receive_add_recipient(recipient, -1); | |
1703 | break; | |
1704 | ||
1705 | ||
1706 | /* The DATA command is legal only if it follows successful MAIL FROM | |
1707 | and RCPT TO commands. This function is complete when a valid DATA | |
1708 | command is encountered. */ | |
1709 | ||
1710 | case DATA_CMD: | |
1711 | if (sender_address == NULL || recipients_count <= 0) | |
1712 | { | |
1713 | /* The function moan_smtp_batch() does not return. */ | |
1714 | if (sender_address == NULL) | |
3ee512ff | 1715 | moan_smtp_batch(smtp_cmd_buffer, |
059ec3d9 PH |
1716 | "503 MAIL FROM:<sender> command must precede DATA"); |
1717 | else | |
3ee512ff | 1718 | moan_smtp_batch(smtp_cmd_buffer, |
059ec3d9 PH |
1719 | "503 RCPT TO:<recipient> must precede DATA"); |
1720 | } | |
1721 | else | |
1722 | { | |
1723 | done = 3; /* DATA successfully achieved */ | |
1724 | message_ended = END_NOTENDED; /* Indicate in middle of message */ | |
1725 | } | |
1726 | break; | |
1727 | ||
1728 | ||
1729 | /* The VRFY, EXPN, HELP, ETRN, and NOOP commands are ignored. */ | |
1730 | ||
1731 | case VRFY_CMD: | |
1732 | case EXPN_CMD: | |
1733 | case HELP_CMD: | |
1734 | case NOOP_CMD: | |
1735 | case ETRN_CMD: | |
1736 | bsmtp_transaction_linecount = receive_linecount; | |
1737 | break; | |
1738 | ||
1739 | ||
1740 | case EOF_CMD: | |
1741 | case QUIT_CMD: | |
1742 | done = 2; | |
1743 | break; | |
1744 | ||
1745 | ||
1746 | case BADARG_CMD: | |
1747 | /* The function moan_smtp_batch() does not return. */ | |
3ee512ff | 1748 | moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected argument data"); |
059ec3d9 PH |
1749 | break; |
1750 | ||
1751 | ||
1752 | case BADCHAR_CMD: | |
1753 | /* The function moan_smtp_batch() does not return. */ | |
3ee512ff | 1754 | moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected NULL in SMTP command"); |
059ec3d9 PH |
1755 | break; |
1756 | ||
1757 | ||
1758 | default: | |
1759 | /* The function moan_smtp_batch() does not return. */ | |
3ee512ff | 1760 | moan_smtp_batch(smtp_cmd_buffer, "500 Command unrecognized"); |
059ec3d9 PH |
1761 | break; |
1762 | } | |
1763 | } | |
1764 | ||
1765 | return done - 2; /* Convert yield values */ | |
1766 | } | |
1767 | ||
1768 | ||
1769 | ||
1770 | ||
1771 | /************************************************* | |
1772 | * Start an SMTP session * | |
1773 | *************************************************/ | |
1774 | ||
1775 | /* This function is called at the start of an SMTP session. Thereafter, | |
1776 | smtp_setup_msg() is called to initiate each separate message. This | |
1777 | function does host-specific testing, and outputs the banner line. | |
1778 | ||
1779 | Arguments: none | |
1780 | Returns: FALSE if the session can not continue; something has | |
1781 | gone wrong, or the connection to the host is blocked | |
1782 | */ | |
1783 | ||
1784 | BOOL | |
1785 | smtp_start_session(void) | |
1786 | { | |
1787 | int size = 256; | |
4e88a19f PH |
1788 | int ptr, esclen; |
1789 | uschar *user_msg, *log_msg; | |
1790 | uschar *code, *esc; | |
059ec3d9 PH |
1791 | uschar *p, *s, *ss; |
1792 | ||
b4ed4da0 PH |
1793 | smtp_connection_start = time(NULL); |
1794 | for (smtp_ch_index = 0; smtp_ch_index < SMTP_HBUFF_SIZE; smtp_ch_index++) | |
1795 | smtp_connection_had[smtp_ch_index] = SCH_NONE; | |
1796 | smtp_ch_index = 0; | |
1797 | ||
00f00ca5 PH |
1798 | /* Default values for certain variables */ |
1799 | ||
059ec3d9 | 1800 | helo_seen = esmtp = helo_accept_junk = FALSE; |
b4ed4da0 | 1801 | smtp_mailcmd_count = 0; |
059ec3d9 PH |
1802 | count_nonmail = TRUE_UNSET; |
1803 | synprot_error_count = unknown_command_count = nonmail_command_count = 0; | |
1804 | smtp_delay_mail = smtp_rlm_base; | |
1805 | auth_advertised = FALSE; | |
1806 | pipelining_advertised = FALSE; | |
cf8b11a5 | 1807 | pipelining_enable = TRUE; |
059ec3d9 | 1808 | sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING; |
8f128379 | 1809 | smtp_exit_function_called = FALSE; /* For avoiding loop in not-quit exit */ |
059ec3d9 PH |
1810 | |
1811 | memset(sender_host_cache, 0, sizeof(sender_host_cache)); | |
1812 | ||
33d73e3b PH |
1813 | /* If receiving by -bs from a trusted user, or testing with -bh, we allow |
1814 | authentication settings from -oMaa to remain in force. */ | |
1815 | ||
1816 | if (!host_checking && !sender_host_notsocket) sender_host_authenticated = NULL; | |
059ec3d9 PH |
1817 | authenticated_by = NULL; |
1818 | ||
1819 | #ifdef SUPPORT_TLS | |
817d9f57 | 1820 | tls_in.cipher = tls_in.peerdn = NULL; |
059ec3d9 PH |
1821 | tls_advertised = FALSE; |
1822 | #endif | |
1823 | ||
1824 | /* Reset ACL connection variables */ | |
1825 | ||
38a0a95f | 1826 | acl_var_c = NULL; |
059ec3d9 | 1827 | |
ca86f471 | 1828 | /* Allow for trailing 0 in the command and data buffers. */ |
3ee512ff | 1829 | |
ca86f471 | 1830 | smtp_cmd_buffer = (uschar *)malloc(2*smtp_cmd_buffer_size + 2); |
3ee512ff | 1831 | if (smtp_cmd_buffer == NULL) |
059ec3d9 PH |
1832 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, |
1833 | "malloc() failed for SMTP command buffer"); | |
2416c261 | 1834 | smtp_cmd_buffer[0] = 0; |
ca86f471 | 1835 | smtp_data_buffer = smtp_cmd_buffer + smtp_cmd_buffer_size + 1; |
059ec3d9 PH |
1836 | |
1837 | /* For batched input, the protocol setting can be overridden from the | |
1838 | command line by a trusted caller. */ | |
1839 | ||
1840 | if (smtp_batched_input) | |
1841 | { | |
1842 | if (received_protocol == NULL) received_protocol = US"local-bsmtp"; | |
1843 | } | |
1844 | ||
1845 | /* For non-batched SMTP input, the protocol setting is forced here. It will be | |
1846 | reset later if any of EHLO/AUTH/STARTTLS are received. */ | |
1847 | ||
1848 | else | |
1849 | received_protocol = | |
1850 | protocols[pnormal] + ((sender_host_address != NULL)? pnlocal : 0); | |
1851 | ||
1852 | /* Set up the buffer for inputting using direct read() calls, and arrange to | |
1853 | call the local functions instead of the standard C ones. */ | |
1854 | ||
1855 | smtp_inbuffer = (uschar *)malloc(in_buffer_size); | |
1856 | if (smtp_inbuffer == NULL) | |
1857 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "malloc() failed for SMTP input buffer"); | |
1858 | receive_getc = smtp_getc; | |
1859 | receive_ungetc = smtp_ungetc; | |
1860 | receive_feof = smtp_feof; | |
1861 | receive_ferror = smtp_ferror; | |
58eb016e | 1862 | receive_smtp_buffered = smtp_buffered; |
059ec3d9 PH |
1863 | smtp_inptr = smtp_inend = smtp_inbuffer; |
1864 | smtp_had_eof = smtp_had_error = 0; | |
1865 | ||
1866 | /* Set up the message size limit; this may be host-specific */ | |
1867 | ||
d45b1de8 PH |
1868 | thismessage_size_limit = expand_string_integer(message_size_limit, TRUE); |
1869 | if (expand_string_message != NULL) | |
059ec3d9 PH |
1870 | { |
1871 | if (thismessage_size_limit == -1) | |
1872 | log_write(0, LOG_MAIN|LOG_PANIC, "unable to expand message_size_limit: " | |
1873 | "%s", expand_string_message); | |
1874 | else | |
1875 | log_write(0, LOG_MAIN|LOG_PANIC, "invalid message_size_limit: " | |
1876 | "%s", expand_string_message); | |
1877 | smtp_closedown(US"Temporary local problem - please try later"); | |
1878 | return FALSE; | |
1879 | } | |
1880 | ||
1881 | /* When a message is input locally via the -bs or -bS options, sender_host_ | |
1882 | unknown is set unless -oMa was used to force an IP address, in which case it | |
1883 | is checked like a real remote connection. When -bs is used from inetd, this | |
1884 | flag is not set, causing the sending host to be checked. The code that deals | |
1885 | with IP source routing (if configured) is never required for -bs or -bS and | |
1886 | the flag sender_host_notsocket is used to suppress it. | |
1887 | ||
1888 | If smtp_accept_max and smtp_accept_reserve are set, keep some connections in | |
1889 | reserve for certain hosts and/or networks. */ | |
1890 | ||
1891 | if (!sender_host_unknown) | |
1892 | { | |
1893 | int rc; | |
1894 | BOOL reserved_host = FALSE; | |
1895 | ||
1896 | /* Look up IP options (source routing info) on the socket if this is not an | |
1897 | -oMa "host", and if any are found, log them and drop the connection. | |
1898 | ||
1899 | Linux (and others now, see below) is different to everyone else, so there | |
1900 | has to be some conditional compilation here. Versions of Linux before 2.1.15 | |
1901 | used a structure whose name was "options". Somebody finally realized that | |
1902 | this name was silly, and it got changed to "ip_options". I use the | |
1903 | newer name here, but there is a fudge in the script that sets up os.h | |
1904 | to define a macro in older Linux systems. | |
1905 | ||
1906 | Sigh. Linux is a fast-moving target. Another generation of Linux uses | |
1907 | glibc 2, which has chosen ip_opts for the structure name. This is now | |
1908 | really a glibc thing rather than a Linux thing, so the condition name | |
1909 | has been changed to reflect this. It is relevant also to GNU/Hurd. | |
1910 | ||
1911 | Mac OS 10.x (Darwin) is like the later glibc versions, but without the | |
1912 | setting of the __GLIBC__ macro, so we can't detect it automatically. There's | |
1913 | a special macro defined in the os.h file. | |
1914 | ||
1915 | Some DGUX versions on older hardware appear not to support IP options at | |
1916 | all, so there is now a general macro which can be set to cut out this | |
1917 | support altogether. | |
1918 | ||
1919 | How to do this properly in IPv6 is not yet known. */ | |
1920 | ||
1921 | #if !HAVE_IPV6 && !defined(NO_IP_OPTIONS) | |
1922 | ||
1923 | #ifdef GLIBC_IP_OPTIONS | |
1924 | #if (!defined __GLIBC__) || (__GLIBC__ < 2) | |
1925 | #define OPTSTYLE 1 | |
1926 | #else | |
1927 | #define OPTSTYLE 2 | |
1928 | #endif | |
1929 | #elif defined DARWIN_IP_OPTIONS | |
1930 | #define OPTSTYLE 2 | |
1931 | #else | |
1932 | #define OPTSTYLE 3 | |
1933 | #endif | |
1934 | ||
1935 | if (!host_checking && !sender_host_notsocket) | |
1936 | { | |
1937 | #if OPTSTYLE == 1 | |
36a3b041 | 1938 | EXIM_SOCKLEN_T optlen = sizeof(struct ip_options) + MAX_IPOPTLEN; |
059ec3d9 PH |
1939 | struct ip_options *ipopt = store_get(optlen); |
1940 | #elif OPTSTYLE == 2 | |
1941 | struct ip_opts ipoptblock; | |
1942 | struct ip_opts *ipopt = &ipoptblock; | |
36a3b041 | 1943 | EXIM_SOCKLEN_T optlen = sizeof(ipoptblock); |
059ec3d9 PH |
1944 | #else |
1945 | struct ipoption ipoptblock; | |
1946 | struct ipoption *ipopt = &ipoptblock; | |
36a3b041 | 1947 | EXIM_SOCKLEN_T optlen = sizeof(ipoptblock); |
059ec3d9 PH |
1948 | #endif |
1949 | ||
1950 | /* Occasional genuine failures of getsockopt() have been seen - for | |
1951 | example, "reset by peer". Therefore, just log and give up on this | |
1952 | call, unless the error is ENOPROTOOPT. This error is given by systems | |
1953 | that have the interfaces but not the mechanism - e.g. GNU/Hurd at the time | |
1954 | of writing. So for that error, carry on - we just can't do an IP options | |
1955 | check. */ | |
1956 | ||
1957 | DEBUG(D_receive) debug_printf("checking for IP options\n"); | |
1958 | ||
1959 | if (getsockopt(fileno(smtp_out), IPPROTO_IP, IP_OPTIONS, (uschar *)(ipopt), | |
1960 | &optlen) < 0) | |
1961 | { | |
1962 | if (errno != ENOPROTOOPT) | |
1963 | { | |
1964 | log_write(0, LOG_MAIN, "getsockopt() failed from %s: %s", | |
1965 | host_and_ident(FALSE), strerror(errno)); | |
1966 | smtp_printf("451 SMTP service not available\r\n"); | |
1967 | return FALSE; | |
1968 | } | |
1969 | } | |
1970 | ||
1971 | /* Deal with any IP options that are set. On the systems I have looked at, | |
1972 | the value of MAX_IPOPTLEN has been 40, meaning that there should never be | |
1973 | more logging data than will fit in big_buffer. Nevertheless, after somebody | |
1974 | questioned this code, I've added in some paranoid checking. */ | |
1975 | ||
1976 | else if (optlen > 0) | |
1977 | { | |
1978 | uschar *p = big_buffer; | |
1979 | uschar *pend = big_buffer + big_buffer_size; | |
1980 | uschar *opt, *adptr; | |
1981 | int optcount; | |
1982 | struct in_addr addr; | |
1983 | ||
1984 | #if OPTSTYLE == 1 | |
1985 | uschar *optstart = (uschar *)(ipopt->__data); | |
1986 | #elif OPTSTYLE == 2 | |
1987 | uschar *optstart = (uschar *)(ipopt->ip_opts); | |
1988 | #else | |
1989 | uschar *optstart = (uschar *)(ipopt->ipopt_list); | |
1990 | #endif | |
1991 | ||
1992 | DEBUG(D_receive) debug_printf("IP options exist\n"); | |
1993 | ||
1994 | Ustrcpy(p, "IP options on incoming call:"); | |
1995 | p += Ustrlen(p); | |
1996 | ||
1997 | for (opt = optstart; opt != NULL && | |
1998 | opt < (uschar *)(ipopt) + optlen;) | |
1999 | { | |
2000 | switch (*opt) | |
2001 | { | |
2002 | case IPOPT_EOL: | |
2003 | opt = NULL; | |
2004 | break; | |
2005 | ||
2006 | case IPOPT_NOP: | |
2007 | opt++; | |
2008 | break; | |
2009 | ||
2010 | case IPOPT_SSRR: | |
2011 | case IPOPT_LSRR: | |
2012 | if (!string_format(p, pend-p, " %s [@%s", | |
2013 | (*opt == IPOPT_SSRR)? "SSRR" : "LSRR", | |
2014 | #if OPTSTYLE == 1 | |
2015 | inet_ntoa(*((struct in_addr *)(&(ipopt->faddr)))))) | |
2016 | #elif OPTSTYLE == 2 | |
2017 | inet_ntoa(ipopt->ip_dst))) | |
2018 | #else | |
2019 | inet_ntoa(ipopt->ipopt_dst))) | |
2020 | #endif | |
2021 | { | |
2022 | opt = NULL; | |
2023 | break; | |
2024 | } | |
2025 | ||
2026 | p += Ustrlen(p); | |
2027 | optcount = (opt[1] - 3) / sizeof(struct in_addr); | |
2028 | adptr = opt + 3; | |
2029 | while (optcount-- > 0) | |
2030 | { | |
2031 | memcpy(&addr, adptr, sizeof(addr)); | |
2032 | if (!string_format(p, pend - p - 1, "%s%s", | |
2033 | (optcount == 0)? ":" : "@", inet_ntoa(addr))) | |
2034 | { | |
2035 | opt = NULL; | |
2036 | break; | |
2037 | } | |
2038 | p += Ustrlen(p); | |
2039 | adptr += sizeof(struct in_addr); | |
2040 | } | |
2041 | *p++ = ']'; | |
2042 | opt += opt[1]; | |
2043 | break; | |
2044 | ||
2045 | default: | |
2046 | { | |
2047 | int i; | |
2048 | if (pend - p < 4 + 3*opt[1]) { opt = NULL; break; } | |
2049 | Ustrcat(p, "[ "); | |
2050 | p += 2; | |
2051 | for (i = 0; i < opt[1]; i++) | |
2052 | { | |
2053 | sprintf(CS p, "%2.2x ", opt[i]); | |
2054 | p += 3; | |
2055 | } | |
2056 | *p++ = ']'; | |
2057 | } | |
2058 | opt += opt[1]; | |
2059 | break; | |
2060 | } | |
2061 | } | |
2062 | ||
2063 | *p = 0; | |
2064 | log_write(0, LOG_MAIN, "%s", big_buffer); | |
2065 | ||
2066 | /* Refuse any call with IP options. This is what tcpwrappers 7.5 does. */ | |
2067 | ||
2068 | log_write(0, LOG_MAIN|LOG_REJECT, | |
2069 | "connection from %s refused (IP options)", host_and_ident(FALSE)); | |
2070 | ||
2071 | smtp_printf("554 SMTP service not available\r\n"); | |
2072 | return FALSE; | |
2073 | } | |
2074 | ||
2075 | /* Length of options = 0 => there are no options */ | |
2076 | ||
2077 | else DEBUG(D_receive) debug_printf("no IP options found\n"); | |
2078 | } | |
2079 | #endif /* HAVE_IPV6 && !defined(NO_IP_OPTIONS) */ | |
2080 | ||
2081 | /* Set keep-alive in socket options. The option is on by default. This | |
2082 | setting is an attempt to get rid of some hanging connections that stick in | |
2083 | read() when the remote end (usually a dialup) goes away. */ | |
2084 | ||
2085 | if (smtp_accept_keepalive && !sender_host_notsocket) | |
2086 | ip_keepalive(fileno(smtp_out), sender_host_address, FALSE); | |
2087 | ||
2088 | /* If the current host matches host_lookup, set the name by doing a | |
2089 | reverse lookup. On failure, sender_host_name will be NULL and | |
2090 | host_lookup_failed will be TRUE. This may or may not be serious - optional | |
2091 | checks later. */ | |
2092 | ||
2093 | if (verify_check_host(&host_lookup) == OK) | |
2094 | { | |
2095 | (void)host_name_lookup(); | |
2096 | host_build_sender_fullhost(); | |
2097 | } | |
2098 | ||
2099 | /* Delay this until we have the full name, if it is looked up. */ | |
2100 | ||
2101 | set_process_info("handling incoming connection from %s", | |
2102 | host_and_ident(FALSE)); | |
2103 | ||
2104 | /* Start up TLS if tls_on_connect is set. This is for supporting the legacy | |
2105 | smtps port for use with older style SSL MTAs. */ | |
2106 | ||
2107 | #ifdef SUPPORT_TLS | |
817d9f57 | 2108 | if (tls_in.on_connect && tls_server_start(tls_require_ciphers) != OK) |
059ec3d9 PH |
2109 | return FALSE; |
2110 | #endif | |
2111 | ||
2112 | /* Test for explicit connection rejection */ | |
2113 | ||
2114 | if (verify_check_host(&host_reject_connection) == OK) | |
2115 | { | |
2116 | log_write(L_connection_reject, LOG_MAIN|LOG_REJECT, "refused connection " | |
2117 | "from %s (host_reject_connection)", host_and_ident(FALSE)); | |
2118 | smtp_printf("554 SMTP service not available\r\n"); | |
2119 | return FALSE; | |
2120 | } | |
2121 | ||
afb3eaaf PH |
2122 | /* Test with TCP Wrappers if so configured. There is a problem in that |
2123 | hosts_ctl() returns 0 (deny) under a number of system failure circumstances, | |
2124 | such as disks dying. In these cases, it is desirable to reject with a 4xx | |
2125 | error instead of a 5xx error. There isn't a "right" way to detect such | |
2126 | problems. The following kludge is used: errno is zeroed before calling | |
2127 | hosts_ctl(). If the result is "reject", a 5xx error is given only if the | |
2128 | value of errno is 0 or ENOENT (which happens if /etc/hosts.{allow,deny} does | |
2129 | not exist). */ | |
059ec3d9 PH |
2130 | |
2131 | #ifdef USE_TCP_WRAPPERS | |
afb3eaaf | 2132 | errno = 0; |
5dc43717 JJ |
2133 | tcp_wrappers_name = expand_string(tcp_wrappers_daemon_name); |
2134 | if (tcp_wrappers_name == NULL) | |
2135 | { | |
2136 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" " | |
2137 | "(tcp_wrappers_name) failed: %s", string_printing(tcp_wrappers_name), | |
2138 | expand_string_message); | |
2139 | } | |
2140 | if (!hosts_ctl(tcp_wrappers_name, | |
059ec3d9 PH |
2141 | (sender_host_name == NULL)? STRING_UNKNOWN : CS sender_host_name, |
2142 | (sender_host_address == NULL)? STRING_UNKNOWN : CS sender_host_address, | |
2143 | (sender_ident == NULL)? STRING_UNKNOWN : CS sender_ident)) | |
2144 | { | |
afb3eaaf PH |
2145 | if (errno == 0 || errno == ENOENT) |
2146 | { | |
2147 | HDEBUG(D_receive) debug_printf("tcp wrappers rejection\n"); | |
2148 | log_write(L_connection_reject, | |
2149 | LOG_MAIN|LOG_REJECT, "refused connection from %s " | |
2150 | "(tcp wrappers)", host_and_ident(FALSE)); | |
2151 | smtp_printf("554 SMTP service not available\r\n"); | |
2152 | } | |
2153 | else | |
2154 | { | |
2155 | int save_errno = errno; | |
2156 | HDEBUG(D_receive) debug_printf("tcp wrappers rejected with unexpected " | |
2157 | "errno value %d\n", save_errno); | |
2158 | log_write(L_connection_reject, | |
2159 | LOG_MAIN|LOG_REJECT, "temporarily refused connection from %s " | |
2160 | "(tcp wrappers errno=%d)", host_and_ident(FALSE), save_errno); | |
2161 | smtp_printf("451 Temporary local problem - please try later\r\n"); | |
2162 | } | |
059ec3d9 PH |
2163 | return FALSE; |
2164 | } | |
2165 | #endif | |
2166 | ||
b01dd148 PH |
2167 | /* Check for reserved slots. The value of smtp_accept_count has already been |
2168 | incremented to include this process. */ | |
059ec3d9 PH |
2169 | |
2170 | if (smtp_accept_max > 0 && | |
b01dd148 | 2171 | smtp_accept_count > smtp_accept_max - smtp_accept_reserve) |
059ec3d9 PH |
2172 | { |
2173 | if ((rc = verify_check_host(&smtp_reserve_hosts)) != OK) | |
2174 | { | |
2175 | log_write(L_connection_reject, | |
2176 | LOG_MAIN, "temporarily refused connection from %s: not in " | |
2177 | "reserve list: connected=%d max=%d reserve=%d%s", | |
b01dd148 | 2178 | host_and_ident(FALSE), smtp_accept_count - 1, smtp_accept_max, |
059ec3d9 PH |
2179 | smtp_accept_reserve, (rc == DEFER)? " (lookup deferred)" : ""); |
2180 | smtp_printf("421 %s: Too many concurrent SMTP connections; " | |
2181 | "please try again later\r\n", smtp_active_hostname); | |
2182 | return FALSE; | |
2183 | } | |
2184 | reserved_host = TRUE; | |
2185 | } | |
2186 | ||
2187 | /* If a load level above which only messages from reserved hosts are | |
2188 | accepted is set, check the load. For incoming calls via the daemon, the | |
2189 | check is done in the superior process if there are no reserved hosts, to | |
2190 | save a fork. In all cases, the load average will already be available | |
2191 | in a global variable at this point. */ | |
2192 | ||
2193 | if (smtp_load_reserve >= 0 && | |
2194 | load_average > smtp_load_reserve && | |
2195 | !reserved_host && | |
2196 | verify_check_host(&smtp_reserve_hosts) != OK) | |
2197 | { | |
2198 | log_write(L_connection_reject, | |
2199 | LOG_MAIN, "temporarily refused connection from %s: not in " | |
2200 | "reserve list and load average = %.2f", host_and_ident(FALSE), | |
2201 | (double)load_average/1000.0); | |
2202 | smtp_printf("421 %s: Too much load; please try again later\r\n", | |
2203 | smtp_active_hostname); | |
2204 | return FALSE; | |
2205 | } | |
2206 | ||
2207 | /* Determine whether unqualified senders or recipients are permitted | |
2208 | for this host. Unfortunately, we have to do this every time, in order to | |
2209 | set the flags so that they can be inspected when considering qualifying | |
2210 | addresses in the headers. For a site that permits no qualification, this | |
2211 | won't take long, however. */ | |
2212 | ||
2213 | allow_unqualified_sender = | |
2214 | verify_check_host(&sender_unqualified_hosts) == OK; | |
2215 | ||
2216 | allow_unqualified_recipient = | |
2217 | verify_check_host(&recipient_unqualified_hosts) == OK; | |
2218 | ||
2219 | /* Determine whether HELO/EHLO is required for this host. The requirement | |
2220 | can be hard or soft. */ | |
2221 | ||
2222 | helo_required = verify_check_host(&helo_verify_hosts) == OK; | |
2223 | if (!helo_required) | |
2224 | helo_verify = verify_check_host(&helo_try_verify_hosts) == OK; | |
2225 | ||
2226 | /* Determine whether this hosts is permitted to send syntactic junk | |
2227 | after a HELO or EHLO command. */ | |
2228 | ||
2229 | helo_accept_junk = verify_check_host(&helo_accept_junk_hosts) == OK; | |
2230 | } | |
2231 | ||
2232 | /* For batch SMTP input we are now done. */ | |
2233 | ||
2234 | if (smtp_batched_input) return TRUE; | |
2235 | ||
a3c86431 TL |
2236 | #ifdef EXPERIMENTAL_PROXY |
2237 | /* If valid Proxy Protocol source is connecting, set up session. | |
2238 | * Failure will not allow any SMTP function other than QUIT. */ | |
2239 | proxy_session = FALSE; | |
2240 | proxy_session_failed = FALSE; | |
2241 | if (check_proxy_protocol_host()) | |
2242 | { | |
2243 | if (setup_proxy_protocol_host() == FALSE) | |
2244 | { | |
2245 | proxy_session_failed = TRUE; | |
2246 | DEBUG(D_receive) | |
2247 | debug_printf("Failure to extract proxied host, only QUIT allowed\n"); | |
2248 | } | |
2249 | else | |
2250 | { | |
2251 | sender_host_name = NULL; | |
2252 | (void)host_name_lookup(); | |
2253 | host_build_sender_fullhost(); | |
2254 | } | |
2255 | } | |
2256 | #endif | |
2257 | ||
059ec3d9 PH |
2258 | /* Run the ACL if it exists */ |
2259 | ||
4e88a19f | 2260 | user_msg = NULL; |
059ec3d9 PH |
2261 | if (acl_smtp_connect != NULL) |
2262 | { | |
2263 | int rc; | |
64ffc24f | 2264 | rc = acl_check(ACL_WHERE_CONNECT, NULL, acl_smtp_connect, &user_msg, |
059ec3d9 PH |
2265 | &log_msg); |
2266 | if (rc != OK) | |
2267 | { | |
2268 | (void)smtp_handle_acl_fail(ACL_WHERE_CONNECT, rc, user_msg, log_msg); | |
2269 | return FALSE; | |
2270 | } | |
2271 | } | |
2272 | ||
2273 | /* Output the initial message for a two-way SMTP connection. It may contain | |
2274 | newlines, which then cause a multi-line response to be given. */ | |
2275 | ||
4e88a19f PH |
2276 | code = US"220"; /* Default status code */ |
2277 | esc = US""; /* Default extended status code */ | |
2278 | esclen = 0; /* Length of esc */ | |
2279 | ||
2280 | if (user_msg == NULL) | |
2281 | { | |
2282 | s = expand_string(smtp_banner); | |
2283 | if (s == NULL) | |
2284 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" (smtp_banner) " | |
2285 | "failed: %s", smtp_banner, expand_string_message); | |
2286 | } | |
2287 | else | |
2288 | { | |
2289 | int codelen = 3; | |
2290 | s = user_msg; | |
2291 | smtp_message_code(&code, &codelen, &s, NULL); | |
d6a96edc | 2292 | if (codelen > 4) |
4e88a19f PH |
2293 | { |
2294 | esc = code + 4; | |
2295 | esclen = codelen - 4; | |
2296 | } | |
2297 | } | |
059ec3d9 PH |
2298 | |
2299 | /* Remove any terminating newlines; might as well remove trailing space too */ | |
2300 | ||
2301 | p = s + Ustrlen(s); | |
2302 | while (p > s && isspace(p[-1])) p--; | |
2303 | *p = 0; | |
2304 | ||
2305 | /* It seems that CC:Mail is braindead, and assumes that the greeting message | |
2306 | is all contained in a single IP packet. The original code wrote out the | |
2307 | greeting using several calls to fprint/fputc, and on busy servers this could | |
2308 | cause it to be split over more than one packet - which caused CC:Mail to fall | |
2309 | over when it got the second part of the greeting after sending its first | |
2310 | command. Sigh. To try to avoid this, build the complete greeting message | |
2311 | first, and output it in one fell swoop. This gives a better chance of it | |
2312 | ending up as a single packet. */ | |
2313 | ||
2314 | ss = store_get(size); | |
2315 | ptr = 0; | |
2316 | ||
2317 | p = s; | |
2318 | do /* At least once, in case we have an empty string */ | |
2319 | { | |
2320 | int len; | |
2321 | uschar *linebreak = Ustrchr(p, '\n'); | |
4e88a19f | 2322 | ss = string_cat(ss, &size, &ptr, code, 3); |
059ec3d9 PH |
2323 | if (linebreak == NULL) |
2324 | { | |
2325 | len = Ustrlen(p); | |
4e88a19f | 2326 | ss = string_cat(ss, &size, &ptr, US" ", 1); |
059ec3d9 PH |
2327 | } |
2328 | else | |
2329 | { | |
2330 | len = linebreak - p; | |
4e88a19f | 2331 | ss = string_cat(ss, &size, &ptr, US"-", 1); |
059ec3d9 | 2332 | } |
4e88a19f | 2333 | ss = string_cat(ss, &size, &ptr, esc, esclen); |
059ec3d9 PH |
2334 | ss = string_cat(ss, &size, &ptr, p, len); |
2335 | ss = string_cat(ss, &size, &ptr, US"\r\n", 2); | |
2336 | p += len; | |
2337 | if (linebreak != NULL) p++; | |
2338 | } | |
2339 | while (*p != 0); | |
2340 | ||
2341 | ss[ptr] = 0; /* string_cat leaves room for this */ | |
2342 | ||
2343 | /* Before we write the banner, check that there is no input pending, unless | |
2344 | this synchronisation check is disabled. */ | |
2345 | ||
a14e5636 | 2346 | if (!check_sync()) |
059ec3d9 | 2347 | { |
a14e5636 PH |
2348 | log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol " |
2349 | "synchronization error (input sent without waiting for greeting): " | |
2350 | "rejected connection from %s input=\"%s\"", host_and_ident(TRUE), | |
2351 | string_printing(smtp_inptr)); | |
2352 | smtp_printf("554 SMTP synchronization error\r\n"); | |
2353 | return FALSE; | |
059ec3d9 PH |
2354 | } |
2355 | ||
2356 | /* Now output the banner */ | |
2357 | ||
2358 | smtp_printf("%s", ss); | |
2359 | return TRUE; | |
2360 | } | |
2361 | ||
2362 | ||
2363 | ||
2364 | ||
2365 | ||
2366 | /************************************************* | |
2367 | * Handle SMTP syntax and protocol errors * | |
2368 | *************************************************/ | |
2369 | ||
2370 | /* Write to the log for SMTP syntax errors in incoming commands, if configured | |
2371 | to do so. Then transmit the error response. The return value depends on the | |
2372 | number of syntax and protocol errors in this SMTP session. | |
2373 | ||
2374 | Arguments: | |
2375 | type error type, given as a log flag bit | |
2376 | code response code; <= 0 means don't send a response | |
2377 | data data to reflect in the response (can be NULL) | |
2378 | errmess the error message | |
2379 | ||
2380 | Returns: -1 limit of syntax/protocol errors NOT exceeded | |
2381 | +1 limit of syntax/protocol errors IS exceeded | |
2382 | ||
2383 | These values fit in with the values of the "done" variable in the main | |
2384 | processing loop in smtp_setup_msg(). */ | |
2385 | ||
2386 | static int | |
2387 | synprot_error(int type, int code, uschar *data, uschar *errmess) | |
2388 | { | |
2389 | int yield = -1; | |
2390 | ||
2391 | log_write(type, LOG_MAIN, "SMTP %s error in \"%s\" %s %s", | |
2392 | (type == L_smtp_syntax_error)? "syntax" : "protocol", | |
3ee512ff | 2393 | string_printing(smtp_cmd_buffer), host_and_ident(TRUE), errmess); |
059ec3d9 PH |
2394 | |
2395 | if (++synprot_error_count > smtp_max_synprot_errors) | |
2396 | { | |
2397 | yield = 1; | |
2398 | log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many " | |
2399 | "syntax or protocol errors (last command was \"%s\")", | |
3ee512ff | 2400 | host_and_ident(FALSE), smtp_cmd_buffer); |
059ec3d9 PH |
2401 | } |
2402 | ||
2403 | if (code > 0) | |
2404 | { | |
2405 | smtp_printf("%d%c%s%s%s\r\n", code, (yield == 1)? '-' : ' ', | |
2406 | (data == NULL)? US"" : data, (data == NULL)? US"" : US": ", errmess); | |
2407 | if (yield == 1) | |
2408 | smtp_printf("%d Too many syntax or protocol errors\r\n", code); | |
2409 | } | |
2410 | ||
2411 | return yield; | |
2412 | } | |
2413 | ||
2414 | ||
2415 | ||
2416 | ||
2417 | /************************************************* | |
2418 | * Log incomplete transactions * | |
2419 | *************************************************/ | |
2420 | ||
2421 | /* This function is called after a transaction has been aborted by RSET, QUIT, | |
2422 | connection drops or other errors. It logs the envelope information received | |
2423 | so far in order to preserve address verification attempts. | |
2424 | ||
2425 | Argument: string to indicate what aborted the transaction | |
2426 | Returns: nothing | |
2427 | */ | |
2428 | ||
2429 | static void | |
2430 | incomplete_transaction_log(uschar *what) | |
2431 | { | |
2432 | if (sender_address == NULL || /* No transaction in progress */ | |
2433 | (log_write_selector & L_smtp_incomplete_transaction) == 0 /* Not logging */ | |
2434 | ) return; | |
2435 | ||
2436 | /* Build list of recipients for logging */ | |
2437 | ||
2438 | if (recipients_count > 0) | |
2439 | { | |
2440 | int i; | |
2441 | raw_recipients = store_get(recipients_count * sizeof(uschar *)); | |
2442 | for (i = 0; i < recipients_count; i++) | |
2443 | raw_recipients[i] = recipients_list[i].address; | |
2444 | raw_recipients_count = recipients_count; | |
2445 | } | |
2446 | ||
2447 | log_write(L_smtp_incomplete_transaction, LOG_MAIN|LOG_SENDER|LOG_RECIPIENTS, | |
2448 | "%s incomplete transaction (%s)", host_and_ident(TRUE), what); | |
2449 | } | |
2450 | ||
2451 | ||
2452 | ||
2453 | ||
2454 | /************************************************* | |
2455 | * Send SMTP response, possibly multiline * | |
2456 | *************************************************/ | |
2457 | ||
2458 | /* There are, it seems, broken clients out there that cannot handle multiline | |
2459 | responses. If no_multiline_responses is TRUE (it can be set from an ACL), we | |
2460 | output nothing for non-final calls, and only the first line for anything else. | |
2461 | ||
2462 | Arguments: | |
a5bd321b | 2463 | code SMTP code, may involve extended status codes |
d6a96edc | 2464 | codelen length of smtp code; if > 4 there's an ESC |
059ec3d9 PH |
2465 | final FALSE if the last line isn't the final line |
2466 | msg message text, possibly containing newlines | |
2467 | ||
2468 | Returns: nothing | |
2469 | */ | |
2470 | ||
2471 | void | |
a5bd321b | 2472 | smtp_respond(uschar* code, int codelen, BOOL final, uschar *msg) |
059ec3d9 | 2473 | { |
a5bd321b PH |
2474 | int esclen = 0; |
2475 | uschar *esc = US""; | |
2476 | ||
059ec3d9 PH |
2477 | if (!final && no_multiline_responses) return; |
2478 | ||
d6a96edc | 2479 | if (codelen > 4) |
a5bd321b PH |
2480 | { |
2481 | esc = code + 4; | |
2482 | esclen = codelen - 4; | |
2483 | } | |
2484 | ||
2679d413 PH |
2485 | /* If this is the first output for a (non-batch) RCPT command, see if all RCPTs |
2486 | have had the same. Note: this code is also present in smtp_printf(). It would | |
2487 | be tidier to have it only in one place, but when it was added, it was easier to | |
2488 | do it that way, so as not to have to mess with the code for the RCPT command, | |
2489 | which sometimes uses smtp_printf() and sometimes smtp_respond(). */ | |
2490 | ||
2491 | if (rcpt_in_progress) | |
2492 | { | |
2493 | if (rcpt_smtp_response == NULL) | |
2494 | rcpt_smtp_response = string_copy(msg); | |
2495 | else if (rcpt_smtp_response_same && | |
2496 | Ustrcmp(rcpt_smtp_response, msg) != 0) | |
2497 | rcpt_smtp_response_same = FALSE; | |
2498 | rcpt_in_progress = FALSE; | |
2499 | } | |
2500 | ||
2501 | /* Not output the message, splitting it up into multiple lines if necessary. */ | |
2502 | ||
059ec3d9 PH |
2503 | for (;;) |
2504 | { | |
2505 | uschar *nl = Ustrchr(msg, '\n'); | |
2506 | if (nl == NULL) | |
2507 | { | |
a5bd321b | 2508 | smtp_printf("%.3s%c%.*s%s\r\n", code, final? ' ':'-', esclen, esc, msg); |
059ec3d9 PH |
2509 | return; |
2510 | } | |
2511 | else if (nl[1] == 0 || no_multiline_responses) | |
2512 | { | |
a5bd321b PH |
2513 | smtp_printf("%.3s%c%.*s%.*s\r\n", code, final? ' ':'-', esclen, esc, |
2514 | (int)(nl - msg), msg); | |
059ec3d9 PH |
2515 | return; |
2516 | } | |
2517 | else | |
2518 | { | |
a5bd321b | 2519 | smtp_printf("%.3s-%.*s%.*s\r\n", code, esclen, esc, (int)(nl - msg), msg); |
059ec3d9 PH |
2520 | msg = nl + 1; |
2521 | while (isspace(*msg)) msg++; | |
2522 | } | |
2523 | } | |
2524 | } | |
2525 | ||
2526 | ||
2527 | ||
2528 | ||
4e88a19f PH |
2529 | /************************************************* |
2530 | * Parse user SMTP message * | |
2531 | *************************************************/ | |
2532 | ||
2533 | /* This function allows for user messages overriding the response code details | |
2534 | by providing a suitable response code string at the start of the message | |
2535 | user_msg. Check the message for starting with a response code and optionally an | |
2536 | extended status code. If found, check that the first digit is valid, and if so, | |
2537 | change the code pointer and length to use the replacement. An invalid code | |
2538 | causes a panic log; in this case, if the log messages is the same as the user | |
2539 | message, we must also adjust the value of the log message to show the code that | |
2540 | is actually going to be used (the original one). | |
2541 | ||
2542 | This function is global because it is called from receive.c as well as within | |
2543 | this module. | |
2544 | ||
d6a96edc PH |
2545 | Note that the code length returned includes the terminating whitespace |
2546 | character, which is always included in the regex match. | |
2547 | ||
4e88a19f PH |
2548 | Arguments: |
2549 | code SMTP code, may involve extended status codes | |
d6a96edc | 2550 | codelen length of smtp code; if > 4 there's an ESC |
4e88a19f PH |
2551 | msg message text |
2552 | log_msg optional log message, to be adjusted with the new SMTP code | |
2553 | ||
2554 | Returns: nothing | |
2555 | */ | |
2556 | ||
2557 | void | |
2558 | smtp_message_code(uschar **code, int *codelen, uschar **msg, uschar **log_msg) | |
2559 | { | |
2560 | int n; | |
2561 | int ovector[3]; | |
2562 | ||
2563 | if (msg == NULL || *msg == NULL) return; | |
2564 | ||
2565 | n = pcre_exec(regex_smtp_code, NULL, CS *msg, Ustrlen(*msg), 0, | |
2566 | PCRE_EOPT, ovector, sizeof(ovector)/sizeof(int)); | |
2567 | if (n < 0) return; | |
2568 | ||
2569 | if ((*msg)[0] != (*code)[0]) | |
2570 | { | |
2571 | log_write(0, LOG_MAIN|LOG_PANIC, "configured error code starts with " | |
2572 | "incorrect digit (expected %c) in \"%s\"", (*code)[0], *msg); | |
2573 | if (log_msg != NULL && *log_msg == *msg) | |
2574 | *log_msg = string_sprintf("%s %s", *code, *log_msg + ovector[1]); | |
2575 | } | |
2576 | else | |
2577 | { | |
2578 | *code = *msg; | |
2579 | *codelen = ovector[1]; /* Includes final space */ | |
2580 | } | |
2581 | *msg += ovector[1]; /* Chop the code off the message */ | |
2582 | return; | |
2583 | } | |
2584 | ||
2585 | ||
2586 | ||
2587 | ||
059ec3d9 PH |
2588 | /************************************************* |
2589 | * Handle an ACL failure * | |
2590 | *************************************************/ | |
2591 | ||
2592 | /* This function is called when acl_check() fails. As well as calls from within | |
2593 | this module, it is called from receive.c for an ACL after DATA. It sorts out | |
2594 | logging the incident, and sets up the error response. A message containing | |
2595 | newlines is turned into a multiline SMTP response, but for logging, only the | |
2596 | first line is used. | |
2597 | ||
a5bd321b PH |
2598 | There's a table of default permanent failure response codes to use in |
2599 | globals.c, along with the table of names. VFRY is special. Despite RFC1123 it | |
2600 | defaults disabled in Exim. However, discussion in connection with RFC 821bis | |
2601 | (aka RFC 2821) has concluded that the response should be 252 in the disabled | |
2602 | state, because there are broken clients that try VRFY before RCPT. A 5xx | |
2603 | response should be given only when the address is positively known to be | |
2604 | undeliverable. Sigh. Also, for ETRN, 458 is given on refusal, and for AUTH, | |
2605 | 503. | |
2606 | ||
2607 | From Exim 4.63, it is possible to override the response code details by | |
2608 | providing a suitable response code string at the start of the message provided | |
2609 | in user_msg. The code's first digit is checked for validity. | |
059ec3d9 PH |
2610 | |
2611 | Arguments: | |
2612 | where where the ACL was called from | |
2613 | rc the failure code | |
2614 | user_msg a message that can be included in an SMTP response | |
2615 | log_msg a message for logging | |
2616 | ||
2617 | Returns: 0 in most cases | |
2618 | 2 if the failure code was FAIL_DROP, in which case the | |
2619 | SMTP connection should be dropped (this value fits with the | |
2620 | "done" variable in smtp_setup_msg() below) | |
2621 | */ | |
2622 | ||
2623 | int | |
2624 | smtp_handle_acl_fail(int where, int rc, uschar *user_msg, uschar *log_msg) | |
2625 | { | |
059ec3d9 | 2626 | BOOL drop = rc == FAIL_DROP; |
a5bd321b | 2627 | int codelen = 3; |
a5bd321b | 2628 | uschar *smtp_code; |
059ec3d9 PH |
2629 | uschar *lognl; |
2630 | uschar *sender_info = US""; | |
64ffc24f | 2631 | uschar *what = |
8523533c | 2632 | #ifdef WITH_CONTENT_SCAN |
64ffc24f | 2633 | (where == ACL_WHERE_MIME)? US"during MIME ACL checks" : |
8e669ac1 | 2634 | #endif |
64ffc24f PH |
2635 | (where == ACL_WHERE_PREDATA)? US"DATA" : |
2636 | (where == ACL_WHERE_DATA)? US"after DATA" : | |
fd98a5c6 JH |
2637 | #ifdef EXPERIMENTAL_PRDR |
2638 | (where == ACL_WHERE_PRDR)? US"after DATA PRDR" : | |
2639 | #endif | |
ca86f471 | 2640 | (smtp_cmd_data == NULL)? |
64ffc24f | 2641 | string_sprintf("%s in \"connect\" ACL", acl_wherenames[where]) : |
ca86f471 | 2642 | string_sprintf("%s %s", acl_wherenames[where], smtp_cmd_data); |
059ec3d9 PH |
2643 | |
2644 | if (drop) rc = FAIL; | |
2645 | ||
4e88a19f | 2646 | /* Set the default SMTP code, and allow a user message to change it. */ |
a5bd321b PH |
2647 | |
2648 | smtp_code = (rc != FAIL)? US"451" : acl_wherecodes[where]; | |
4e88a19f | 2649 | smtp_message_code(&smtp_code, &codelen, &user_msg, &log_msg); |
a5bd321b | 2650 | |
059ec3d9 PH |
2651 | /* We used to have sender_address here; however, there was a bug that was not |
2652 | updating sender_address after a rewrite during a verify. When this bug was | |
2653 | fixed, sender_address at this point became the rewritten address. I'm not sure | |
2654 | this is what should be logged, so I've changed to logging the unrewritten | |
2655 | address to retain backward compatibility. */ | |
2656 | ||
8523533c | 2657 | #ifndef WITH_CONTENT_SCAN |
059ec3d9 | 2658 | if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA) |
8523533c TK |
2659 | #else |
2660 | if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA || where == ACL_WHERE_MIME) | |
2661 | #endif | |
059ec3d9 | 2662 | { |
b98bb9ac PP |
2663 | sender_info = string_sprintf("F=<%s>%s%s%s%s ", |
2664 | sender_address_unrewritten ? sender_address_unrewritten : sender_address, | |
2665 | sender_host_authenticated ? US" A=" : US"", | |
2666 | sender_host_authenticated ? sender_host_authenticated : US"", | |
2667 | sender_host_authenticated && authenticated_id ? US":" : US"", | |
2668 | sender_host_authenticated && authenticated_id ? authenticated_id : US"" | |
2669 | ); | |
059ec3d9 PH |
2670 | } |
2671 | ||
2672 | /* If there's been a sender verification failure with a specific message, and | |
2673 | we have not sent a response about it yet, do so now, as a preliminary line for | |
278c6e6c PH |
2674 | failures, but not defers. However, always log it for defer, and log it for fail |
2675 | unless the sender_verify_fail log selector has been turned off. */ | |
059ec3d9 PH |
2676 | |
2677 | if (sender_verified_failed != NULL && | |
2678 | !testflag(sender_verified_failed, af_sverify_told)) | |
2679 | { | |
2679d413 PH |
2680 | BOOL save_rcpt_in_progress = rcpt_in_progress; |
2681 | rcpt_in_progress = FALSE; /* So as not to treat these as the error */ | |
2682 | ||
059ec3d9 PH |
2683 | setflag(sender_verified_failed, af_sverify_told); |
2684 | ||
278c6e6c PH |
2685 | if (rc != FAIL || (log_extra_selector & LX_sender_verify_fail) != 0) |
2686 | log_write(0, LOG_MAIN|LOG_REJECT, "%s sender verify %s for <%s>%s", | |
2687 | host_and_ident(TRUE), | |
2688 | ((sender_verified_failed->special_action & 255) == DEFER)? "defer":"fail", | |
2689 | sender_verified_failed->address, | |
2690 | (sender_verified_failed->message == NULL)? US"" : | |
2691 | string_sprintf(": %s", sender_verified_failed->message)); | |
059ec3d9 PH |
2692 | |
2693 | if (rc == FAIL && sender_verified_failed->user_message != NULL) | |
a5bd321b | 2694 | smtp_respond(smtp_code, codelen, FALSE, string_sprintf( |
059ec3d9 PH |
2695 | testflag(sender_verified_failed, af_verify_pmfail)? |
2696 | "Postmaster verification failed while checking <%s>\n%s\n" | |
2697 | "Several RFCs state that you are required to have a postmaster\n" | |
2698 | "mailbox for each mail domain. This host does not accept mail\n" | |
2699 | "from domains whose servers reject the postmaster address." | |
2700 | : | |
2701 | testflag(sender_verified_failed, af_verify_nsfail)? | |
2702 | "Callback setup failed while verifying <%s>\n%s\n" | |
2703 | "The initial connection, or a HELO or MAIL FROM:<> command was\n" | |
2704 | "rejected. Refusing MAIL FROM:<> does not help fight spam, disregards\n" | |
2705 | "RFC requirements, and stops you from receiving standard bounce\n" | |
2706 | "messages. This host does not accept mail from domains whose servers\n" | |
2707 | "refuse bounces." | |
2708 | : | |
2709 | "Verification failed for <%s>\n%s", | |
2710 | sender_verified_failed->address, | |
2711 | sender_verified_failed->user_message)); | |
2679d413 PH |
2712 | |
2713 | rcpt_in_progress = save_rcpt_in_progress; | |
059ec3d9 PH |
2714 | } |
2715 | ||
2716 | /* Sort out text for logging */ | |
2717 | ||
2718 | log_msg = (log_msg == NULL)? US"" : string_sprintf(": %s", log_msg); | |
2719 | lognl = Ustrchr(log_msg, '\n'); | |
2720 | if (lognl != NULL) *lognl = 0; | |
2721 | ||
2722 | /* Send permanent failure response to the command, but the code used isn't | |
2723 | always a 5xx one - see comments at the start of this function. If the original | |
2724 | rc was FAIL_DROP we drop the connection and yield 2. */ | |
2725 | ||
a5bd321b | 2726 | if (rc == FAIL) smtp_respond(smtp_code, codelen, TRUE, (user_msg == NULL)? |
059ec3d9 PH |
2727 | US"Administrative prohibition" : user_msg); |
2728 | ||
2729 | /* Send temporary failure response to the command. Don't give any details, | |
2730 | unless acl_temp_details is set. This is TRUE for a callout defer, a "defer" | |
2731 | verb, and for a header verify when smtp_return_error_details is set. | |
2732 | ||
2733 | This conditional logic is all somewhat of a mess because of the odd | |
2734 | interactions between temp_details and return_error_details. One day it should | |
2735 | be re-implemented in a tidier fashion. */ | |
2736 | ||
2737 | else | |
2738 | { | |
2739 | if (acl_temp_details && user_msg != NULL) | |
2740 | { | |
2741 | if (smtp_return_error_details && | |
2742 | sender_verified_failed != NULL && | |
2743 | sender_verified_failed->message != NULL) | |
2744 | { | |
a5bd321b | 2745 | smtp_respond(smtp_code, codelen, FALSE, sender_verified_failed->message); |
059ec3d9 | 2746 | } |
a5bd321b | 2747 | smtp_respond(smtp_code, codelen, TRUE, user_msg); |
059ec3d9 PH |
2748 | } |
2749 | else | |
a5bd321b PH |
2750 | smtp_respond(smtp_code, codelen, TRUE, |
2751 | US"Temporary local problem - please try later"); | |
059ec3d9 PH |
2752 | } |
2753 | ||
6ea85e9a PH |
2754 | /* Log the incident to the logs that are specified by log_reject_target |
2755 | (default main, reject). This can be empty to suppress logging of rejections. If | |
2756 | the connection is not forcibly to be dropped, return 0. Otherwise, log why it | |
2757 | is closing if required and return 2. */ | |
059ec3d9 | 2758 | |
6ea85e9a | 2759 | if (log_reject_target != 0) |
887291d2 | 2760 | { |
e45a1c37 | 2761 | #ifdef SUPPORT_TLS |
887291d2 JH |
2762 | uschar * s = s_tlslog(NULL, NULL, NULL); |
2763 | if (!s) s = US""; | |
e45a1c37 | 2764 | #else |
887291d2 | 2765 | uschar * s = US""; |
e45a1c37 | 2766 | #endif |
887291d2 JH |
2767 | log_write(0, log_reject_target, "%s%s %s%srejected %s%s", |
2768 | host_and_ident(TRUE), s, | |
6ea85e9a | 2769 | sender_info, (rc == FAIL)? US"" : US"temporarily ", what, log_msg); |
887291d2 | 2770 | } |
059ec3d9 PH |
2771 | |
2772 | if (!drop) return 0; | |
2773 | ||
2774 | log_write(L_smtp_connection, LOG_MAIN, "%s closed by DROP in ACL", | |
2775 | smtp_get_connection_info()); | |
8f128379 PH |
2776 | |
2777 | /* Run the not-quit ACL, but without any custom messages. This should not be a | |
2778 | problem, because we get here only if some other ACL has issued "drop", and | |
2779 | in that case, *its* custom messages will have been used above. */ | |
2780 | ||
2781 | smtp_notquit_exit(US"acl-drop", NULL, NULL); | |
059ec3d9 PH |
2782 | return 2; |
2783 | } | |
2784 | ||
2785 | ||
2786 | ||
2787 | ||
8f128379 PH |
2788 | /************************************************* |
2789 | * Handle SMTP exit when QUIT is not given * | |
2790 | *************************************************/ | |
2791 | ||
2792 | /* This function provides a logging/statistics hook for when an SMTP connection | |
2793 | is dropped on the floor or the other end goes away. It's a global function | |
2794 | because it's called from receive.c as well as this module. As well as running | |
2795 | the NOTQUIT ACL, if there is one, this function also outputs a final SMTP | |
2796 | response, either with a custom message from the ACL, or using a default. There | |
2797 | is one case, however, when no message is output - after "drop". In that case, | |
2798 | the ACL that obeyed "drop" has already supplied the custom message, and NULL is | |
2799 | passed to this function. | |
2800 | ||
2801 | In case things go wrong while processing this function, causing an error that | |
2802 | may re-enter this funtion, there is a recursion check. | |
2803 | ||
2804 | Arguments: | |
2805 | reason What $smtp_notquit_reason will be set to in the ACL; | |
2806 | if NULL, the ACL is not run | |
2807 | code The error code to return as part of the response | |
2808 | defaultrespond The default message if there's no user_msg | |
2809 | ||
2810 | Returns: Nothing | |
2811 | */ | |
2812 | ||
2813 | void | |
2814 | smtp_notquit_exit(uschar *reason, uschar *code, uschar *defaultrespond, ...) | |
2815 | { | |
2816 | int rc; | |
2817 | uschar *user_msg = NULL; | |
2818 | uschar *log_msg = NULL; | |
2819 | ||
2820 | /* Check for recursive acll */ | |
2821 | ||
2822 | if (smtp_exit_function_called) | |
2823 | { | |
2824 | log_write(0, LOG_PANIC, "smtp_notquit_exit() called more than once (%s)", | |
2825 | reason); | |
2826 | return; | |
2827 | } | |
2828 | smtp_exit_function_called = TRUE; | |
2829 | ||
2830 | /* Call the not-QUIT ACL, if there is one, unless no reason is given. */ | |
2831 | ||
2832 | if (acl_smtp_notquit != NULL && reason != NULL) | |
2833 | { | |
2834 | smtp_notquit_reason = reason; | |
2835 | rc = acl_check(ACL_WHERE_NOTQUIT, NULL, acl_smtp_notquit, &user_msg, | |
2836 | &log_msg); | |
2837 | if (rc == ERROR) | |
2838 | log_write(0, LOG_MAIN|LOG_PANIC, "ACL for not-QUIT returned ERROR: %s", | |
2839 | log_msg); | |
2840 | } | |
2841 | ||
2842 | /* Write an SMTP response if we are expected to give one. As the default | |
2843 | responses are all internal, they should always fit in the buffer, but code a | |
2844 | warning, just in case. Note that string_vformat() still leaves a complete | |
2845 | string, even if it is incomplete. */ | |
2846 | ||
2847 | if (code != NULL && defaultrespond != NULL) | |
2848 | { | |
2849 | if (user_msg == NULL) | |
2850 | { | |
2851 | uschar buffer[128]; | |
2852 | va_list ap; | |
2853 | va_start(ap, defaultrespond); | |
2854 | if (!string_vformat(buffer, sizeof(buffer), CS defaultrespond, ap)) | |
2855 | log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_notquit_exit()"); | |
2856 | smtp_printf("%s %s\r\n", code, buffer); | |
2857 | va_end(ap); | |
2858 | } | |
2859 | else | |
2860 | smtp_respond(code, 3, TRUE, user_msg); | |
2861 | mac_smtp_fflush(); | |
2862 | } | |
2863 | } | |
2864 | ||
2865 | ||
2866 | ||
2867 | ||
d7b47fd0 PH |
2868 | /************************************************* |
2869 | * Verify HELO argument * | |
2870 | *************************************************/ | |
2871 | ||
2872 | /* This function is called if helo_verify_hosts or helo_try_verify_hosts is | |
2873 | matched. It is also called from ACL processing if verify = helo is used and | |
2874 | verification was not previously tried (i.e. helo_try_verify_hosts was not | |
2875 | matched). The result of its processing is to set helo_verified and | |
2876 | helo_verify_failed. These variables should both be FALSE for this function to | |
2877 | be called. | |
2878 | ||
2879 | Note that EHLO/HELO is legitimately allowed to quote an address literal. Allow | |
2880 | for IPv6 ::ffff: literals. | |
2881 | ||
2882 | Argument: none | |
2883 | Returns: TRUE if testing was completed; | |
2884 | FALSE on a temporary failure | |
2885 | */ | |
2886 | ||
2887 | BOOL | |
2888 | smtp_verify_helo(void) | |
2889 | { | |
2890 | BOOL yield = TRUE; | |
2891 | ||
2892 | HDEBUG(D_receive) debug_printf("verifying EHLO/HELO argument \"%s\"\n", | |
2893 | sender_helo_name); | |
2894 | ||
2895 | if (sender_helo_name == NULL) | |
2896 | { | |
2897 | HDEBUG(D_receive) debug_printf("no EHLO/HELO command was issued\n"); | |
2898 | } | |
2899 | ||
d1d5595c PH |
2900 | /* Deal with the case of -bs without an IP address */ |
2901 | ||
2902 | else if (sender_host_address == NULL) | |
2903 | { | |
2904 | HDEBUG(D_receive) debug_printf("no client IP address: assume success\n"); | |
2905 | helo_verified = TRUE; | |
2906 | } | |
2907 | ||
2908 | /* Deal with the more common case when there is a sending IP address */ | |
2909 | ||
d7b47fd0 PH |
2910 | else if (sender_helo_name[0] == '[') |
2911 | { | |
2912 | helo_verified = Ustrncmp(sender_helo_name+1, sender_host_address, | |
2913 | Ustrlen(sender_host_address)) == 0; | |
2914 | ||
2915 | #if HAVE_IPV6 | |
2916 | if (!helo_verified) | |
2917 | { | |
2918 | if (strncmpic(sender_host_address, US"::ffff:", 7) == 0) | |
2919 | helo_verified = Ustrncmp(sender_helo_name + 1, | |
2920 | sender_host_address + 7, Ustrlen(sender_host_address) - 7) == 0; | |
2921 | } | |
2922 | #endif | |
2923 | ||
2924 | HDEBUG(D_receive) | |
2925 | { if (helo_verified) debug_printf("matched host address\n"); } | |
2926 | } | |
2927 | ||
2928 | /* Do a reverse lookup if one hasn't already given a positive or negative | |
2929 | response. If that fails, or the name doesn't match, try checking with a forward | |
2930 | lookup. */ | |
2931 | ||
2932 | else | |
2933 | { | |
2934 | if (sender_host_name == NULL && !host_lookup_failed) | |
2935 | yield = host_name_lookup() != DEFER; | |
2936 | ||
2937 | /* If a host name is known, check it and all its aliases. */ | |
2938 | ||
2939 | if (sender_host_name != NULL) | |
2940 | { | |
2941 | helo_verified = strcmpic(sender_host_name, sender_helo_name) == 0; | |
2942 | ||
2943 | if (helo_verified) | |
2944 | { | |
2945 | HDEBUG(D_receive) debug_printf("matched host name\n"); | |
2946 | } | |
2947 | else | |
2948 | { | |
2949 | uschar **aliases = sender_host_aliases; | |
2950 | while (*aliases != NULL) | |
2951 | { | |
2952 | helo_verified = strcmpic(*aliases++, sender_helo_name) == 0; | |
2953 | if (helo_verified) break; | |
2954 | } | |
2955 | HDEBUG(D_receive) | |
2956 | { | |
2957 | if (helo_verified) | |
2958 | debug_printf("matched alias %s\n", *(--aliases)); | |
2959 | } | |
2960 | } | |
2961 | } | |
2962 | ||
2963 | /* Final attempt: try a forward lookup of the helo name */ | |
2964 | ||
2965 | if (!helo_verified) | |
2966 | { | |
2967 | int rc; | |
2968 | host_item h; | |
2969 | h.name = sender_helo_name; | |
2970 | h.address = NULL; | |
2971 | h.mx = MX_NONE; | |
2972 | h.next = NULL; | |
2973 | HDEBUG(D_receive) debug_printf("getting IP address for %s\n", | |
2974 | sender_helo_name); | |
322050c2 | 2975 | rc = host_find_byname(&h, NULL, 0, NULL, TRUE); |
d7b47fd0 PH |
2976 | if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL) |
2977 | { | |
2978 | host_item *hh = &h; | |
2979 | while (hh != NULL) | |
2980 | { | |
2981 | if (Ustrcmp(hh->address, sender_host_address) == 0) | |
2982 | { | |
2983 | helo_verified = TRUE; | |
2984 | HDEBUG(D_receive) | |
2985 | debug_printf("IP address for %s matches calling address\n", | |
2986 | sender_helo_name); | |
2987 | break; | |
2988 | } | |
2989 | hh = hh->next; | |
2990 | } | |
2991 | } | |
2992 | } | |
2993 | } | |
2994 | ||
d1d5595c | 2995 | if (!helo_verified) helo_verify_failed = TRUE; /* We've tried ... */ |
d7b47fd0 PH |
2996 | return yield; |
2997 | } | |
2998 | ||
2999 | ||
3000 | ||
3001 | ||
4e88a19f PH |
3002 | /************************************************* |
3003 | * Send user response message * | |
3004 | *************************************************/ | |
3005 | ||
3006 | /* This function is passed a default response code and a user message. It calls | |
3007 | smtp_message_code() to check and possibly modify the response code, and then | |
3008 | calls smtp_respond() to transmit the response. I put this into a function | |
3009 | just to avoid a lot of repetition. | |
3010 | ||
3011 | Arguments: | |
3012 | code the response code | |
3013 | user_msg the user message | |
3014 | ||
3015 | Returns: nothing | |
3016 | */ | |
3017 | ||
3018 | static void | |
3019 | smtp_user_msg(uschar *code, uschar *user_msg) | |
3020 | { | |
3021 | int len = 3; | |
3022 | smtp_message_code(&code, &len, &user_msg, NULL); | |
3023 | smtp_respond(code, len, TRUE, user_msg); | |
3024 | } | |
3025 | ||
3026 | ||
3027 | ||
059ec3d9 PH |
3028 | /************************************************* |
3029 | * Initialize for SMTP incoming message * | |
3030 | *************************************************/ | |
3031 | ||
3032 | /* This function conducts the initial dialogue at the start of an incoming SMTP | |
3033 | message, and builds a list of recipients. However, if the incoming message | |
3034 | is part of a batch (-bS option) a separate function is called since it would | |
3035 | be messy having tests splattered about all over this function. This function | |
3036 | therefore handles the case where interaction is occurring. The input and output | |
3037 | files are set up in smtp_in and smtp_out. | |
3038 | ||
3039 | The global recipients_list is set to point to a vector of recipient_item | |
3040 | blocks, whose number is given by recipients_count. This is extended by the | |
3041 | receive_add_recipient() function. The global variable sender_address is set to | |
3042 | the sender's address. The yield is +1 if a message has been successfully | |
3043 | started, 0 if a QUIT command was encountered or the connection was refused from | |
3044 | the particular host, or -1 if the connection was lost. | |
3045 | ||
3046 | Argument: none | |
3047 | ||
3048 | Returns: > 0 message successfully started (reached DATA) | |
3049 | = 0 QUIT read or end of file reached or call refused | |
3050 | < 0 lost connection | |
3051 | */ | |
3052 | ||
3053 | int | |
3054 | smtp_setup_msg(void) | |
3055 | { | |
3056 | int done = 0; | |
3057 | BOOL toomany = FALSE; | |
3058 | BOOL discarded = FALSE; | |
3059 | BOOL last_was_rej_mail = FALSE; | |
3060 | BOOL last_was_rcpt = FALSE; | |
3061 | void *reset_point = store_get(0); | |
3062 | ||
3063 | DEBUG(D_receive) debug_printf("smtp_setup_msg entered\n"); | |
3064 | ||
3065 | /* Reset for start of new message. We allow one RSET not to be counted as a | |
3066 | nonmail command, for those MTAs that insist on sending it between every | |
3067 | message. Ditto for EHLO/HELO and for STARTTLS, to allow for going in and out of | |
3068 | TLS between messages (an Exim client may do this if it has messages queued up | |
3069 | for the host). Note: we do NOT reset AUTH at this point. */ | |
3070 | ||
3071 | smtp_reset(reset_point); | |
3072 | message_ended = END_NOTSTARTED; | |
3073 | ||
3074 | cmd_list[CMD_LIST_RSET].is_mail_cmd = TRUE; | |
3075 | cmd_list[CMD_LIST_HELO].is_mail_cmd = TRUE; | |
3076 | cmd_list[CMD_LIST_EHLO].is_mail_cmd = TRUE; | |
3077 | #ifdef SUPPORT_TLS | |
3078 | cmd_list[CMD_LIST_STARTTLS].is_mail_cmd = TRUE; | |
3079 | #endif | |
3080 | ||
3081 | /* Set the local signal handler for SIGTERM - it tries to end off tidily */ | |
3082 | ||
3083 | os_non_restarting_signal(SIGTERM, command_sigterm_handler); | |
3084 | ||
3085 | /* Batched SMTP is handled in a different function. */ | |
3086 | ||
3087 | if (smtp_batched_input) return smtp_setup_batch_msg(); | |
3088 | ||
3089 | /* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE | |
3090 | value. The values are 2 larger than the required yield of the function. */ | |
3091 | ||
3092 | while (done <= 0) | |
3093 | { | |
3094 | uschar **argv; | |
3095 | uschar *etrn_command; | |
3096 | uschar *etrn_serialize_key; | |
3097 | uschar *errmess; | |
4e88a19f PH |
3098 | uschar *log_msg, *smtp_code; |
3099 | uschar *user_msg = NULL; | |
059ec3d9 PH |
3100 | uschar *recipient = NULL; |
3101 | uschar *hello = NULL; | |
3102 | uschar *set_id = NULL; | |
3103 | uschar *s, *ss; | |
3104 | BOOL was_rej_mail = FALSE; | |
3105 | BOOL was_rcpt = FALSE; | |
3106 | void (*oldsignal)(int); | |
3107 | pid_t pid; | |
3108 | int start, end, sender_domain, recipient_domain; | |
3109 | int ptr, size, rc; | |
f78eb7c6 | 3110 | int c, i; |
059ec3d9 PH |
3111 | auth_instance *au; |
3112 | ||
3113 | switch(smtp_read_command(TRUE)) | |
3114 | { | |
3115 | /* The AUTH command is not permitted to occur inside a transaction, and may | |
c46782ef PH |
3116 | occur successfully only once per connection. Actually, that isn't quite |
3117 | true. When TLS is started, all previous information about a connection must | |
3118 | be discarded, so a new AUTH is permitted at that time. | |
3119 | ||
3120 | AUTH may only be used when it has been advertised. However, it seems that | |
3121 | there are clients that send AUTH when it hasn't been advertised, some of | |
3122 | them even doing this after HELO. And there are MTAs that accept this. Sigh. | |
3123 | So there's a get-out that allows this to happen. | |
059ec3d9 PH |
3124 | |
3125 | AUTH is initially labelled as a "nonmail command" so that one occurrence | |
3126 | doesn't get counted. We change the label here so that multiple failing | |
3127 | AUTHS will eventually hit the nonmail threshold. */ | |
3128 | ||
3129 | case AUTH_CMD: | |
b4ed4da0 | 3130 | HAD(SCH_AUTH); |
059ec3d9 PH |
3131 | authentication_failed = TRUE; |
3132 | cmd_list[CMD_LIST_AUTH].is_mail_cmd = FALSE; | |
3133 | ||
c46782ef | 3134 | if (!auth_advertised && !allow_auth_unadvertised) |
059ec3d9 PH |
3135 | { |
3136 | done = synprot_error(L_smtp_protocol_error, 503, NULL, | |
3137 | US"AUTH command used when not advertised"); | |
3138 | break; | |
3139 | } | |
3140 | if (sender_host_authenticated != NULL) | |
3141 | { | |
3142 | done = synprot_error(L_smtp_protocol_error, 503, NULL, | |
3143 | US"already authenticated"); | |
3144 | break; | |
3145 | } | |
3146 | if (sender_address != NULL) | |
3147 | { | |
3148 | done = synprot_error(L_smtp_protocol_error, 503, NULL, | |
3149 | US"not permitted in mail transaction"); | |
3150 | break; | |
3151 | } | |
3152 | ||
3153 | /* Check the ACL */ | |
3154 | ||
3155 | if (acl_smtp_auth != NULL) | |
3156 | { | |
64ffc24f | 3157 | rc = acl_check(ACL_WHERE_AUTH, NULL, acl_smtp_auth, &user_msg, &log_msg); |
059ec3d9 PH |
3158 | if (rc != OK) |
3159 | { | |
3160 | done = smtp_handle_acl_fail(ACL_WHERE_AUTH, rc, user_msg, log_msg); | |
3161 | break; | |
3162 | } | |
3163 | } | |
3164 | ||
3165 | /* Find the name of the requested authentication mechanism. */ | |
3166 | ||
ca86f471 PH |
3167 | s = smtp_cmd_data; |
3168 | while ((c = *smtp_cmd_data) != 0 && !isspace(c)) | |
059ec3d9 PH |
3169 | { |
3170 | if (!isalnum(c) && c != '-' && c != '_') | |
3171 | { | |
3172 | done = synprot_error(L_smtp_syntax_error, 501, NULL, | |
3173 | US"invalid character in authentication mechanism name"); | |
3174 | goto COMMAND_LOOP; | |
3175 | } | |
ca86f471 | 3176 | smtp_cmd_data++; |
059ec3d9 PH |
3177 | } |
3178 | ||
3179 | /* If not at the end of the line, we must be at white space. Terminate the | |
3180 | name and move the pointer on to any data that may be present. */ | |
3181 | ||
ca86f471 | 3182 | if (*smtp_cmd_data != 0) |
059ec3d9 | 3183 | { |
ca86f471 PH |
3184 | *smtp_cmd_data++ = 0; |
3185 | while (isspace(*smtp_cmd_data)) smtp_cmd_data++; | |
059ec3d9 PH |
3186 | } |
3187 | ||
3188 | /* Search for an authentication mechanism which is configured for use | |
c46782ef PH |
3189 | as a server and which has been advertised (unless, sigh, allow_auth_ |
3190 | unadvertised is set). */ | |
059ec3d9 PH |
3191 | |
3192 | for (au = auths; au != NULL; au = au->next) | |
3193 | { | |
3194 | if (strcmpic(s, au->public_name) == 0 && au->server && | |
c46782ef | 3195 | (au->advertised || allow_auth_unadvertised)) break; |
059ec3d9 PH |
3196 | } |
3197 | ||
3198 | if (au == NULL) | |
3199 | { | |
3200 | done = synprot_error(L_smtp_protocol_error, 504, NULL, | |
3201 | string_sprintf("%s authentication mechanism not supported", s)); | |
3202 | break; | |
3203 | } | |
3204 | ||
f78eb7c6 PH |
3205 | /* Run the checking code, passing the remainder of the command line as |
3206 | data. Initials the $auth<n> variables as empty. Initialize $0 empty and set | |
3207 | it as the only set numerical variable. The authenticator may set $auth<n> | |
3208 | and also set other numeric variables. The $auth<n> variables are preferred | |
3209 | nowadays; the numerical variables remain for backwards compatibility. | |
059ec3d9 | 3210 | |
f78eb7c6 PH |
3211 | Afterwards, have a go at expanding the set_id string, even if |
3212 | authentication failed - for bad passwords it can be useful to log the | |
3213 | userid. On success, require set_id to expand and exist, and put it in | |
3214 | authenticated_id. Save this in permanent store, as the working store gets | |
3215 | reset at HELO, RSET, etc. */ | |
3216 | ||
3217 | for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL; | |
059ec3d9 PH |
3218 | expand_nmax = 0; |
3219 | expand_nlength[0] = 0; /* $0 contains nothing */ | |
3220 | ||
ca86f471 | 3221 | c = (au->info->servercode)(au, smtp_cmd_data); |
059ec3d9 PH |
3222 | if (au->set_id != NULL) set_id = expand_string(au->set_id); |
3223 | expand_nmax = -1; /* Reset numeric variables */ | |
f78eb7c6 | 3224 | for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL; /* Reset $auth<n> */ |
059ec3d9 | 3225 | |
0612b098 PH |
3226 | /* The value of authenticated_id is stored in the spool file and printed in |
3227 | log lines. It must not contain binary zeros or newline characters. In | |
3228 | normal use, it never will, but when playing around or testing, this error | |
3229 | can (did) happen. To guard against this, ensure that the id contains only | |
3230 | printing characters. */ | |
3231 | ||
3232 | if (set_id != NULL) set_id = string_printing(set_id); | |
3233 | ||
059ec3d9 PH |
3234 | /* For the non-OK cases, set up additional logging data if set_id |
3235 | is not empty. */ | |
3236 | ||
3237 | if (c != OK) | |
3238 | { | |
3239 | if (set_id != NULL && *set_id != 0) | |
3240 | set_id = string_sprintf(" (set_id=%s)", set_id); | |
3241 | else set_id = US""; | |
3242 | } | |
3243 | ||
3244 | /* Switch on the result */ | |
3245 | ||
3246 | switch(c) | |
3247 | { | |
3248 | case OK: | |
3249 | if (au->set_id == NULL || set_id != NULL) /* Complete success */ | |
3250 | { | |
3251 | if (set_id != NULL) authenticated_id = string_copy_malloc(set_id); | |
3252 | sender_host_authenticated = au->name; | |
3253 | authentication_failed = FALSE; | |
2d07a215 | 3254 | authenticated_fail_id = NULL; /* Impossible to already be set? */ |
059ec3d9 | 3255 | received_protocol = |
817d9f57 | 3256 | protocols[pextend + pauthed + ((tls_in.active >= 0)? pcrpted:0)] + |
059ec3d9 PH |
3257 | ((sender_host_address != NULL)? pnlocal : 0); |
3258 | s = ss = US"235 Authentication succeeded"; | |
3259 | authenticated_by = au; | |
3260 | break; | |
3261 | } | |
3262 | ||
3263 | /* Authentication succeeded, but we failed to expand the set_id string. | |
3264 | Treat this as a temporary error. */ | |
3265 | ||
3266 | auth_defer_msg = expand_string_message; | |
3267 | /* Fall through */ | |
3268 | ||
3269 | case DEFER: | |
2d07a215 | 3270 | if (set_id != NULL) authenticated_fail_id = string_copy_malloc(set_id); |
059ec3d9 PH |
3271 | s = string_sprintf("435 Unable to authenticate at present%s", |
3272 | auth_defer_user_msg); | |
3273 | ss = string_sprintf("435 Unable to authenticate at present%s: %s", | |
3274 | set_id, auth_defer_msg); | |
3275 | break; | |
3276 | ||
3277 | case BAD64: | |
3278 | s = ss = US"501 Invalid base64 data"; | |
3279 | break; | |
3280 | ||
3281 | case CANCELLED: | |
3282 | s = ss = US"501 Authentication cancelled"; | |
3283 | break; | |
3284 | ||
3285 | case UNEXPECTED: | |
3286 | s = ss = US"553 Initial data not expected"; | |
3287 | break; | |
3288 | ||
3289 | case FAIL: | |
2d07a215 | 3290 | if (set_id != NULL) authenticated_fail_id = string_copy_malloc(set_id); |
059ec3d9 PH |
3291 | s = US"535 Incorrect authentication data"; |
3292 | ss = string_sprintf("535 Incorrect authentication data%s", set_id); | |
3293 | break; | |
3294 | ||
3295 | default: | |
2d07a215 | 3296 | if (set_id != NULL) authenticated_fail_id = string_copy_malloc(set_id); |
059ec3d9 PH |
3297 | s = US"435 Internal error"; |
3298 | ss = string_sprintf("435 Internal error%s: return %d from authentication " | |
3299 | "check", set_id, c); | |
3300 | break; | |
3301 | } | |
3302 | ||
3303 | smtp_printf("%s\r\n", s); | |
3304 | if (c != OK) | |
3305 | log_write(0, LOG_MAIN|LOG_REJECT, "%s authenticator failed for %s: %s", | |
3306 | au->name, host_and_ident(FALSE), ss); | |
3307 | ||
3308 | break; /* AUTH_CMD */ | |
3309 | ||
3310 | /* The HELO/EHLO commands are permitted to appear in the middle of a | |
3311 | session as well as at the beginning. They have the effect of a reset in | |
3312 | addition to their other functions. Their absence at the start cannot be | |
3313 | taken to be an error. | |
3314 | ||
3315 | RFC 2821 says: | |
3316 | ||
3317 | If the EHLO command is not acceptable to the SMTP server, 501, 500, | |
3318 | or 502 failure replies MUST be returned as appropriate. The SMTP | |
3319 | server MUST stay in the same state after transmitting these replies | |
3320 | that it was in before the EHLO was received. | |
3321 | ||
3322 | Therefore, we do not do the reset until after checking the command for | |
3323 | acceptability. This change was made for Exim release 4.11. Previously | |
3324 | it did the reset first. */ | |
3325 | ||
3326 | case HELO_CMD: | |
b4ed4da0 | 3327 | HAD(SCH_HELO); |
059ec3d9 PH |
3328 | hello = US"HELO"; |
3329 | esmtp = FALSE; | |
3330 | goto HELO_EHLO; | |
3331 | ||
3332 | case EHLO_CMD: | |
b4ed4da0 | 3333 | HAD(SCH_EHLO); |
059ec3d9 PH |
3334 | hello = US"EHLO"; |
3335 | esmtp = TRUE; | |
3336 | ||
3337 | HELO_EHLO: /* Common code for HELO and EHLO */ | |
3338 | cmd_list[CMD_LIST_HELO].is_mail_cmd = FALSE; | |
3339 | cmd_list[CMD_LIST_EHLO].is_mail_cmd = FALSE; | |
3340 | ||
3341 | /* Reject the HELO if its argument was invalid or non-existent. A | |
3342 | successful check causes the argument to be saved in malloc store. */ | |
3343 | ||
ca86f471 | 3344 | if (!check_helo(smtp_cmd_data)) |
059ec3d9 PH |
3345 | { |
3346 | smtp_printf("501 Syntactically invalid %s argument(s)\r\n", hello); | |
3347 | ||
3348 | log_write(0, LOG_MAIN|LOG_REJECT, "rejected %s from %s: syntactically " | |
3349 | "invalid argument(s): %s", hello, host_and_ident(FALSE), | |
3ee512ff PH |
3350 | (*smtp_cmd_argument == 0)? US"(no argument given)" : |
3351 | string_printing(smtp_cmd_argument)); | |
059ec3d9 PH |
3352 | |
3353 | if (++synprot_error_count > smtp_max_synprot_errors) | |
3354 | { | |
3355 | log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many " | |
3356 | "syntax or protocol errors (last command was \"%s\")", | |
3ee512ff | 3357 | host_and_ident(FALSE), smtp_cmd_buffer); |
059ec3d9 PH |
3358 | done = 1; |
3359 | } | |
3360 | ||
3361 | break; | |
3362 | } | |
3363 | ||
3364 | /* If sender_host_unknown is true, we have got here via the -bs interface, | |
3365 | not called from inetd. Otherwise, we are running an IP connection and the | |
3366 | host address will be set. If the helo name is the primary name of this | |
3367 | host and we haven't done a reverse lookup, force one now. If helo_required | |
3368 | is set, ensure that the HELO name matches the actual host. If helo_verify | |
3369 | is set, do the same check, but softly. */ | |
3370 | ||
3371 | if (!sender_host_unknown) | |
3372 | { | |
3373 | BOOL old_helo_verified = helo_verified; | |
ca86f471 | 3374 | uschar *p = smtp_cmd_data; |
059ec3d9 PH |
3375 | |
3376 | while (*p != 0 && !isspace(*p)) { *p = tolower(*p); p++; } | |
3377 | *p = 0; | |
3378 | ||
3379 | /* Force a reverse lookup if HELO quoted something in helo_lookup_domains | |
3380 | because otherwise the log can be confusing. */ | |
3381 | ||
3382 | if (sender_host_name == NULL && | |
3383 | (deliver_domain = sender_helo_name, /* set $domain */ | |
3384 | match_isinlist(sender_helo_name, &helo_lookup_domains, 0, | |
3385 | &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL)) == OK) | |
3386 | (void)host_name_lookup(); | |
3387 | ||
3388 | /* Rebuild the fullhost info to include the HELO name (and the real name | |
3389 | if it was looked up.) */ | |
3390 | ||
3391 | host_build_sender_fullhost(); /* Rebuild */ | |
3392 | set_process_info("handling%s incoming connection from %s", | |
817d9f57 | 3393 | (tls_in.active >= 0)? " TLS" : "", host_and_ident(FALSE)); |
059ec3d9 PH |
3394 | |
3395 | /* Verify if configured. This doesn't give much security, but it does | |
d7b47fd0 PH |
3396 | make some people happy to be able to do it. If helo_required is set, |
3397 | (host matches helo_verify_hosts) failure forces rejection. If helo_verify | |
3398 | is set (host matches helo_try_verify_hosts), it does not. This is perhaps | |
3399 | now obsolescent, since the verification can now be requested selectively | |
3400 | at ACL time. */ | |
059ec3d9 | 3401 | |
d7b47fd0 | 3402 | helo_verified = helo_verify_failed = FALSE; |
059ec3d9 PH |
3403 | if (helo_required || helo_verify) |
3404 | { | |
d7b47fd0 | 3405 | BOOL tempfail = !smtp_verify_helo(); |
059ec3d9 PH |
3406 | if (!helo_verified) |
3407 | { | |
3408 | if (helo_required) | |
3409 | { | |
3410 | smtp_printf("%d %s argument does not match calling host\r\n", | |
3411 | tempfail? 451 : 550, hello); | |
3412 | log_write(0, LOG_MAIN|LOG_REJECT, "%srejected \"%s %s\" from %s", | |
3413 | tempfail? "temporarily " : "", | |
3414 | hello, sender_helo_name, host_and_ident(FALSE)); | |
3415 | helo_verified = old_helo_verified; | |
3416 | break; /* End of HELO/EHLO processing */ | |
3417 | } | |
3418 | HDEBUG(D_all) debug_printf("%s verification failed but host is in " | |
3419 | "helo_try_verify_hosts\n", hello); | |
3420 | } | |
3421 | } | |
3422 | } | |
3423 | ||
8523533c TK |
3424 | #ifdef EXPERIMENTAL_SPF |
3425 | /* set up SPF context */ | |
3426 | spf_init(sender_helo_name, sender_host_address); | |
3427 | #endif | |
3428 | ||
a14e5636 PH |
3429 | /* Apply an ACL check if one is defined; afterwards, recheck |
3430 | synchronization in case the client started sending in a delay. */ | |
059ec3d9 PH |
3431 | |
3432 | if (acl_smtp_helo != NULL) | |
3433 | { | |
64ffc24f | 3434 | rc = acl_check(ACL_WHERE_HELO, NULL, acl_smtp_helo, &user_msg, &log_msg); |
059ec3d9 PH |
3435 | if (rc != OK) |
3436 | { | |
3437 | done = smtp_handle_acl_fail(ACL_WHERE_HELO, rc, user_msg, log_msg); | |
3438 | sender_helo_name = NULL; | |
3439 | host_build_sender_fullhost(); /* Rebuild */ | |
3440 | break; | |
3441 | } | |
a14e5636 | 3442 | else if (!check_sync()) goto SYNC_FAILURE; |
059ec3d9 PH |
3443 | } |
3444 | ||
4e88a19f PH |
3445 | /* Generate an OK reply. The default string includes the ident if present, |
3446 | and also the IP address if present. Reflecting back the ident is intended | |
3447 | as a deterrent to mail forgers. For maximum efficiency, and also because | |
3448 | some broken systems expect each response to be in a single packet, arrange | |
3449 | that the entire reply is sent in one write(). */ | |
059ec3d9 PH |
3450 | |
3451 | auth_advertised = FALSE; | |
3452 | pipelining_advertised = FALSE; | |
3453 | #ifdef SUPPORT_TLS | |
3454 | tls_advertised = FALSE; | |
3455 | #endif | |
3456 | ||
d6a96edc | 3457 | smtp_code = US"250 "; /* Default response code plus space*/ |
4e88a19f PH |
3458 | if (user_msg == NULL) |
3459 | { | |
3460 | s = string_sprintf("%.3s %s Hello %s%s%s", | |
3461 | smtp_code, | |
3462 | smtp_active_hostname, | |
3463 | (sender_ident == NULL)? US"" : sender_ident, | |
3464 | (sender_ident == NULL)? US"" : US" at ", | |
3465 | (sender_host_name == NULL)? sender_helo_name : sender_host_name); | |
3466 | ||
3467 | ptr = Ustrlen(s); | |
3468 | size = ptr + 1; | |
059ec3d9 | 3469 | |
4e88a19f PH |
3470 | if (sender_host_address != NULL) |
3471 | { | |
3472 | s = string_cat(s, &size, &ptr, US" [", 2); | |
3473 | s = string_cat(s, &size, &ptr, sender_host_address, | |
3474 | Ustrlen(sender_host_address)); | |
3475 | s = string_cat(s, &size, &ptr, US"]", 1); | |
3476 | } | |
3477 | } | |
3478 | ||
d6a96edc PH |
3479 | /* A user-supplied EHLO greeting may not contain more than one line. Note |
3480 | that the code returned by smtp_message_code() includes the terminating | |
3481 | whitespace character. */ | |
059ec3d9 | 3482 | |
4e88a19f | 3483 | else |
059ec3d9 | 3484 | { |
4e88a19f | 3485 | char *ss; |
d6a96edc | 3486 | int codelen = 4; |
4e88a19f | 3487 | smtp_message_code(&smtp_code, &codelen, &user_msg, NULL); |
d6a96edc | 3488 | s = string_sprintf("%.*s%s", codelen, smtp_code, user_msg); |
4e88a19f PH |
3489 | if ((ss = strpbrk(CS s, "\r\n")) != NULL) |
3490 | { | |
3491 | log_write(0, LOG_MAIN|LOG_PANIC, "EHLO/HELO response must not contain " | |
3492 | "newlines: message truncated: %s", string_printing(s)); | |
3493 | *ss = 0; | |
3494 | } | |
3495 | ptr = Ustrlen(s); | |
3496 | size = ptr + 1; | |
059ec3d9 PH |
3497 | } |
3498 | ||
3499 | s = string_cat(s, &size, &ptr, US"\r\n", 2); | |
3500 | ||
3501 | /* If we received EHLO, we must create a multiline response which includes | |
3502 | the functions supported. */ | |
3503 | ||
3504 | if (esmtp) | |
3505 | { | |
3506 | s[3] = '-'; | |
3507 | ||
3508 | /* I'm not entirely happy with this, as an MTA is supposed to check | |
3509 | that it has enough room to accept a message of maximum size before | |
3510 | it sends this. However, there seems little point in not sending it. | |
3511 | The actual size check happens later at MAIL FROM time. By postponing it | |
3512 | till then, VRFY and EXPN can be used after EHLO when space is short. */ | |
3513 | ||
3514 | if (thismessage_size_limit > 0) | |
3515 | { | |
4e88a19f PH |
3516 | sprintf(CS big_buffer, "%.3s-SIZE %d\r\n", smtp_code, |
3517 | thismessage_size_limit); | |
059ec3d9 PH |
3518 | s = string_cat(s, &size, &ptr, big_buffer, Ustrlen(big_buffer)); |
3519 | } | |
3520 | else | |
3521 | { | |
4e88a19f PH |
3522 | s = string_cat(s, &size, &ptr, smtp_code, 3); |
3523 | s = string_cat(s, &size, &ptr, US"-SIZE\r\n", 7); | |
059ec3d9 PH |
3524 | } |
3525 | ||
3526 | /* Exim does not do protocol conversion or data conversion. It is 8-bit | |
3527 | clean; if it has an 8-bit character in its hand, it just sends it. It | |
3528 | cannot therefore specify 8BITMIME and remain consistent with the RFCs. | |
3529 | However, some users want this option simply in order to stop MUAs | |
3530 | mangling messages that contain top-bit-set characters. It is therefore | |
3531 | provided as an option. */ | |
3532 | ||
3533 | if (accept_8bitmime) | |
4e88a19f PH |
3534 | { |
3535 | s = string_cat(s, &size, &ptr, smtp_code, 3); | |
3536 | s = string_cat(s, &size, &ptr, US"-8BITMIME\r\n", 11); | |
3537 | } | |
059ec3d9 PH |
3538 | |
3539 | /* Advertise ETRN if there's an ACL checking whether a host is | |
3540 | permitted to issue it; a check is made when any host actually tries. */ | |
3541 | ||
3542 | if (acl_smtp_etrn != NULL) | |
3543 | { | |
4e88a19f PH |
3544 | s = string_cat(s, &size, &ptr, smtp_code, 3); |
3545 | s = string_cat(s, &size, &ptr, US"-ETRN\r\n", 7); | |
059ec3d9 PH |
3546 | } |
3547 | ||
3548 | /* Advertise EXPN if there's an ACL checking whether a host is | |
3549 | permitted to issue it; a check is made when any host actually tries. */ | |
3550 | ||
3551 | if (acl_smtp_expn != NULL) | |
3552 | { | |
4e88a19f PH |
3553 | s = string_cat(s, &size, &ptr, smtp_code, 3); |
3554 | s = string_cat(s, &size, &ptr, US"-EXPN\r\n", 7); | |
059ec3d9 PH |
3555 | } |
3556 | ||
3557 | /* Exim is quite happy with pipelining, so let the other end know that | |
3558 | it is safe to use it, unless advertising is disabled. */ | |
3559 | ||
cf8b11a5 PH |
3560 | if (pipelining_enable && |
3561 | verify_check_host(&pipelining_advertise_hosts) == OK) | |
059ec3d9 | 3562 | { |
4e88a19f PH |
3563 | s = string_cat(s, &size, &ptr, smtp_code, 3); |
3564 | s = string_cat(s, &size, &ptr, US"-PIPELINING\r\n", 13); | |
059ec3d9 PH |
3565 | sync_cmd_limit = NON_SYNC_CMD_PIPELINING; |
3566 | pipelining_advertised = TRUE; | |
3567 | } | |
3568 | ||
fd98a5c6 | 3569 | |
059ec3d9 PH |
3570 | /* If any server authentication mechanisms are configured, advertise |
3571 | them if the current host is in auth_advertise_hosts. The problem with | |
3572 | advertising always is that some clients then require users to | |
3573 | authenticate (and aren't configurable otherwise) even though it may not | |
3574 | be necessary (e.g. if the host is in host_accept_relay). | |
3575 | ||
3576 | RFC 2222 states that SASL mechanism names contain only upper case | |
3577 | letters, so output the names in upper case, though we actually recognize | |
3578 | them in either case in the AUTH command. */ | |
3579 | ||
3580 | if (auths != NULL) | |
3581 | { | |
3582 | if (verify_check_host(&auth_advertise_hosts) == OK) | |
3583 | { | |
3584 | auth_instance *au; | |
3585 | BOOL first = TRUE; | |
3586 | for (au = auths; au != NULL; au = au->next) | |
3587 | { | |
3588 | if (au->server && (au->advertise_condition == NULL || | |
3589 | expand_check_condition(au->advertise_condition, au->name, | |
3590 | US"authenticator"))) | |
3591 | { | |
3592 | int saveptr; | |
3593 | if (first) | |
3594 | { | |
4e88a19f PH |
3595 | s = string_cat(s, &size, &ptr, smtp_code, 3); |
3596 | s = string_cat(s, &size, &ptr, US"-AUTH", 5); | |
059ec3d9 PH |
3597 | first = FALSE; |
3598 | auth_advertised = TRUE; | |
3599 | } | |
3600 | saveptr = ptr; | |
3601 | s = string_cat(s, &size, &ptr, US" ", 1); | |
3602 | s = string_cat(s, &size, &ptr, au->public_name, | |
3603 | Ustrlen(au->public_name)); | |
3604 | while (++saveptr < ptr) s[saveptr] = toupper(s[saveptr]); | |
3605 | au->advertised = TRUE; | |
3606 | } | |
3607 | else au->advertised = FALSE; | |
3608 | } | |
3609 | if (!first) s = string_cat(s, &size, &ptr, US"\r\n", 2); | |
3610 | } | |
3611 | } | |
3612 | ||
3613 | /* Advertise TLS (Transport Level Security) aka SSL (Secure Socket Layer) | |
3614 | if it has been included in the binary, and the host matches | |
3615 | tls_advertise_hosts. We must *not* advertise if we are already in a | |
3616 | secure connection. */ | |
3617 | ||
3618 | #ifdef SUPPORT_TLS | |
817d9f57 | 3619 | if (tls_in.active < 0 && |
059ec3d9 PH |
3620 | verify_check_host(&tls_advertise_hosts) != FAIL) |
3621 | { | |
4e88a19f PH |
3622 | s = string_cat(s, &size, &ptr, smtp_code, 3); |
3623 | s = string_cat(s, &size, &ptr, US"-STARTTLS\r\n", 11); | |
059ec3d9 PH |
3624 | tls_advertised = TRUE; |
3625 | } | |
3626 | #endif | |
3627 | ||
fd98a5c6 JH |
3628 | #ifdef EXPERIMENTAL_PRDR |
3629 | /* Per Recipient Data Response, draft by Eric A. Hall extending RFC */ | |
3630 | if (prdr_enable) { | |
3631 | s = string_cat(s, &size, &ptr, smtp_code, 3); | |
3632 | s = string_cat(s, &size, &ptr, US"-PRDR\r\n", 7); | |
3633 | } | |
3634 | #endif | |
3635 | ||
059ec3d9 PH |
3636 | /* Finish off the multiline reply with one that is always available. */ |
3637 | ||
4e88a19f PH |
3638 | s = string_cat(s, &size, &ptr, smtp_code, 3); |
3639 | s = string_cat(s, &size, &ptr, US" HELP\r\n", 7); | |
059ec3d9 PH |
3640 | } |
3641 | ||
3642 | /* Terminate the string (for debug), write it, and note that HELO/EHLO | |
3643 | has been seen. */ | |
3644 | ||
3645 | s[ptr] = 0; | |
3646 | ||
3647 | #ifdef SUPPORT_TLS | |
817d9f57 | 3648 | if (tls_in.active >= 0) (void)tls_write(TRUE, s, ptr); else |
059ec3d9 PH |
3649 | #endif |
3650 | ||
1ac6b2e7 JH |
3651 | { |
3652 | int i = fwrite(s, 1, ptr, smtp_out); i = i; /* compiler quietening */ | |
3653 | } | |
898d150f PH |
3654 | DEBUG(D_receive) |
3655 | { | |
3656 | uschar *cr; | |
3657 | while ((cr = Ustrchr(s, '\r')) != NULL) /* lose CRs */ | |
3658 | memmove(cr, cr + 1, (ptr--) - (cr - s)); | |
3659 | debug_printf("SMTP>> %s", s); | |
3660 | } | |
059ec3d9 | 3661 | helo_seen = TRUE; |
4e88a19f PH |
3662 | |
3663 | /* Reset the protocol and the state, abandoning any previous message. */ | |
3664 | ||
3665 | received_protocol = (esmtp? | |
3666 | protocols[pextend + | |
3667 | ((sender_host_authenticated != NULL)? pauthed : 0) + | |
817d9f57 | 3668 | ((tls_in.active >= 0)? pcrpted : 0)] |
4e88a19f | 3669 | : |
817d9f57 | 3670 | protocols[pnormal + ((tls_in.active >= 0)? pcrpted : 0)]) |
4e88a19f PH |
3671 | + |
3672 | ((sender_host_address != NULL)? pnlocal : 0); | |
3673 | ||
3674 | smtp_reset(reset_point); | |
3675 | toomany = FALSE; | |
059ec3d9 PH |
3676 | break; /* HELO/EHLO */ |
3677 | ||
3678 | ||
3679 | /* The MAIL command requires an address as an operand. All we do | |
3680 | here is to parse it for syntactic correctness. The form "<>" is | |
3681 | a special case which converts into an empty string. The start/end | |
3682 | pointers in the original are not used further for this address, as | |
3683 | it is the canonical extracted address which is all that is kept. */ | |
3684 | ||
3685 | case MAIL_CMD: | |
b4ed4da0 | 3686 | HAD(SCH_MAIL); |
059ec3d9 PH |
3687 | smtp_mailcmd_count++; /* Count for limit and ratelimit */ |
3688 | was_rej_mail = TRUE; /* Reset if accepted */ | |
d27f98fe | 3689 | env_mail_type_t * mail_args; /* Sanity check & validate args */ |
059ec3d9 PH |
3690 | |
3691 | if (helo_required && !helo_seen) | |
3692 | { | |
3693 | smtp_printf("503 HELO or EHLO required\r\n"); | |
3694 | log_write(0, LOG_MAIN|LOG_REJECT, "rejected MAIL from %s: no " | |
3695 | "HELO/EHLO given", host_and_ident(FALSE)); | |
3696 | break; | |
3697 | } | |
3698 | ||
3699 | if (sender_address != NULL) | |
3700 | { | |
3701 | done = synprot_error(L_smtp_protocol_error, 503, NULL, | |
3702 | US"sender already given"); | |
3703 | break; | |
3704 | } | |
3705 | ||
ca86f471 | 3706 | if (smtp_cmd_data[0] == 0) |
059ec3d9 PH |
3707 | { |
3708 | done = synprot_error(L_smtp_protocol_error, 501, NULL, | |
3709 | US"MAIL must have an address operand"); | |
3710 | break; | |
3711 | } | |
3712 | ||
3713 | /* Check to see if the limit for messages per connection would be | |
3714 | exceeded by accepting further messages. */ | |
3715 | ||
3716 | if (smtp_accept_max_per_connection > 0 && | |
3717 | smtp_mailcmd_count > smtp_accept_max_per_connection) | |
3718 | { | |
3719 | smtp_printf("421 too many messages in this connection\r\n"); | |
3720 | log_write(0, LOG_MAIN|LOG_REJECT, "rejected MAIL command %s: too many " | |
3721 | "messages in one connection", host_and_ident(TRUE)); | |
3722 | break; | |
3723 | } | |
3724 | ||
3725 | /* Reset for start of message - even if this is going to fail, we | |
3726 | obviously need to throw away any previous data. */ | |
3727 | ||
3728 | smtp_reset(reset_point); | |
3729 | toomany = FALSE; | |
3730 | sender_data = recipient_data = NULL; | |
3731 | ||
3732 | /* Loop, checking for ESMTP additions to the MAIL FROM command. */ | |
3733 | ||
3734 | if (esmtp) for(;;) | |
3735 | { | |
3736 | uschar *name, *value, *end; | |
3737 | unsigned long int size; | |
d27f98fe | 3738 | BOOL arg_error = FALSE; |
059ec3d9 PH |
3739 | |
3740 | if (!extract_option(&name, &value)) break; | |
3741 | ||
d27f98fe TL |
3742 | for (mail_args = env_mail_type_list; |
3743 | (char *)mail_args < (char *)env_mail_type_list + sizeof(env_mail_type_list); | |
3744 | mail_args++ | |
3745 | ) | |
059ec3d9 | 3746 | { |
d27f98fe TL |
3747 | if (strcmpic(name, mail_args->name) == 0) |
3748 | break; | |
059ec3d9 | 3749 | } |
d27f98fe TL |
3750 | if (mail_args->need_value && strcmpic(value, US"") == 0) |
3751 | break; | |
059ec3d9 | 3752 | |
d27f98fe | 3753 | switch(mail_args->value) |
059ec3d9 | 3754 | { |
d27f98fe TL |
3755 | /* Handle SIZE= by reading the value. We don't do the check till later, |
3756 | in order to be able to log the sender address on failure. */ | |
3757 | case ENV_MAIL_OPT_SIZE: | |
d27f98fe | 3758 | if (((size = Ustrtoul(value, &end, 10)), *end == 0)) |
059ec3d9 | 3759 | { |
d27f98fe TL |
3760 | if ((size == ULONG_MAX && errno == ERANGE) || size > INT_MAX) |
3761 | size = INT_MAX; | |
3762 | message_size = (int)size; | |
059ec3d9 PH |
3763 | } |
3764 | else | |
d27f98fe TL |
3765 | arg_error = TRUE; |
3766 | break; | |
059ec3d9 | 3767 | |
d27f98fe TL |
3768 | /* If this session was initiated with EHLO and accept_8bitmime is set, |
3769 | Exim will have indicated that it supports the BODY=8BITMIME option. In | |
3770 | fact, it does not support this according to the RFCs, in that it does not | |
3771 | take any special action for forwarding messages containing 8-bit | |
3772 | characters. That is why accept_8bitmime is not the default setting, but | |
3773 | some sites want the action that is provided. We recognize both "8BITMIME" | |
3774 | and "7BIT" as body types, but take no action. */ | |
3775 | case ENV_MAIL_OPT_BODY: | |
3c0a92dc JH |
3776 | if (accept_8bitmime) { |
3777 | if (strcmpic(value, US"8BITMIME") == 0) { | |
3778 | body_8bitmime = 8; | |
3779 | } else if (strcmpic(value, US"7BIT") == 0) { | |
3780 | body_8bitmime = 7; | |
3781 | } else { | |
3782 | body_8bitmime = 0; | |
3783 | done = synprot_error(L_smtp_syntax_error, 501, NULL, | |
3784 | US"invalid data for BODY"); | |
3785 | goto COMMAND_LOOP; | |
3786 | } | |
3787 | DEBUG(D_receive) debug_printf("8BITMIME: %d\n", body_8bitmime); | |
3788 | break; | |
3789 | } | |
d27f98fe TL |
3790 | arg_error = TRUE; |
3791 | break; | |
059ec3d9 | 3792 | |
d27f98fe TL |
3793 | /* Handle the AUTH extension. If the value given is not "<>" and either |
3794 | the ACL says "yes" or there is no ACL but the sending host is | |
3795 | authenticated, we set it up as the authenticated sender. However, if the | |
3796 | authenticator set a condition to be tested, we ignore AUTH on MAIL unless | |
3797 | the condition is met. The value of AUTH is an xtext, which means that +, | |
3798 | = and cntrl chars are coded in hex; however "<>" is unaffected by this | |
3799 | coding. */ | |
3800 | case ENV_MAIL_OPT_AUTH: | |
3801 | if (Ustrcmp(value, "<>") != 0) | |
3802 | { | |
3803 | int rc; | |
3804 | uschar *ignore_msg; | |
059ec3d9 | 3805 | |
d27f98fe TL |
3806 | if (auth_xtextdecode(value, &authenticated_sender) < 0) |
3807 | { | |
3808 | /* Put back terminator overrides for error message */ | |
d27f98fe | 3809 | value[-1] = '='; |
fd98a5c6 | 3810 | name[-1] = ' '; |
d27f98fe TL |
3811 | done = synprot_error(L_smtp_syntax_error, 501, NULL, |
3812 | US"invalid data for AUTH"); | |
3813 | goto COMMAND_LOOP; | |
3814 | } | |
3815 | if (acl_smtp_mailauth == NULL) | |
3816 | { | |
3817 | ignore_msg = US"client not authenticated"; | |
3818 | rc = (sender_host_authenticated != NULL)? OK : FAIL; | |
3819 | } | |
3820 | else | |
3821 | { | |
3822 | ignore_msg = US"rejected by ACL"; | |
3823 | rc = acl_check(ACL_WHERE_MAILAUTH, NULL, acl_smtp_mailauth, | |
3824 | &user_msg, &log_msg); | |
3825 | } | |
3826 | ||
3827 | switch (rc) | |
3828 | { | |
3829 | case OK: | |
3830 | if (authenticated_by == NULL || | |
3831 | authenticated_by->mail_auth_condition == NULL || | |
3832 | expand_check_condition(authenticated_by->mail_auth_condition, | |
3833 | authenticated_by->name, US"authenticator")) | |
3834 | break; /* Accept the AUTH */ | |
3835 | ||
3836 | ignore_msg = US"server_mail_auth_condition failed"; | |
3837 | if (authenticated_id != NULL) | |
3838 | ignore_msg = string_sprintf("%s: authenticated ID=\"%s\"", | |
3839 | ignore_msg, authenticated_id); | |
3840 | ||
3841 | /* Fall through */ | |
3842 | ||
3843 | case FAIL: | |
3844 | authenticated_sender = NULL; | |
3845 | log_write(0, LOG_MAIN, "ignoring AUTH=%s from %s (%s)", | |
3846 | value, host_and_ident(TRUE), ignore_msg); | |
3847 | break; | |
3848 | ||
3849 | /* Should only get DEFER or ERROR here. Put back terminator | |
3850 | overrides for error message */ | |
3851 | ||
3852 | default: | |
d27f98fe | 3853 | value[-1] = '='; |
fd98a5c6 | 3854 | name[-1] = ' '; |
d27f98fe TL |
3855 | (void)smtp_handle_acl_fail(ACL_WHERE_MAILAUTH, rc, user_msg, |
3856 | log_msg); | |
3857 | goto COMMAND_LOOP; | |
3858 | } | |
059ec3d9 | 3859 | } |
d27f98fe | 3860 | break; |
fd98a5c6 JH |
3861 | |
3862 | #ifdef EXPERIMENTAL_PRDR | |
3863 | case ENV_MAIL_OPT_PRDR: | |
3864 | if ( prdr_enable ) | |
3865 | prdr_requested = TRUE; | |
3866 | break; | |
3867 | #endif | |
3868 | ||
d27f98fe | 3869 | /* Unknown option. Stick back the terminator characters and break |
fd98a5c6 JH |
3870 | the loop. Do the name-terminator second as extract_option sets |
3871 | value==name when it found no equal-sign. | |
3872 | An error for a malformed address will occur. */ | |
d27f98fe | 3873 | default: |
d27f98fe | 3874 | value[-1] = '='; |
fd98a5c6 JH |
3875 | name[-1] = ' '; |
3876 | arg_error = TRUE; | |
d27f98fe | 3877 | break; |
059ec3d9 | 3878 | } |
d27f98fe TL |
3879 | /* Break out of for loop if switch() had bad argument or |
3880 | when start of the email address is reached */ | |
3881 | if (arg_error) break; | |
059ec3d9 PH |
3882 | } |
3883 | ||
3884 | /* If we have passed the threshold for rate limiting, apply the current | |
3885 | delay, and update it for next time, provided this is a limited host. */ | |
3886 | ||
3887 | if (smtp_mailcmd_count > smtp_rlm_threshold && | |
3888 | verify_check_host(&smtp_ratelimit_hosts) == OK) | |
3889 | { | |
3890 | DEBUG(D_receive) debug_printf("rate limit MAIL: delay %.3g sec\n", | |
3891 | smtp_delay_mail/1000.0); | |
3892 | millisleep((int)smtp_delay_mail); | |
3893 | smtp_delay_mail *= smtp_rlm_factor; | |
3894 | if (smtp_delay_mail > (double)smtp_rlm_limit) | |
3895 | smtp_delay_mail = (double)smtp_rlm_limit; | |
3896 | } | |
3897 | ||
3898 | /* Now extract the address, first applying any SMTP-time rewriting. The | |
3899 | TRUE flag allows "<>" as a sender address. */ | |
3900 | ||
3901 | raw_sender = ((rewrite_existflags & rewrite_smtp) != 0)? | |
ca86f471 PH |
3902 | rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"", |
3903 | global_rewrite_rules) : smtp_cmd_data; | |
059ec3d9 PH |
3904 | |
3905 | /* rfc821_domains = TRUE; << no longer needed */ | |
3906 | raw_sender = | |
3907 | parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain, | |
3908 | TRUE); | |
3909 | /* rfc821_domains = FALSE; << no longer needed */ | |
3910 | ||
3911 | if (raw_sender == NULL) | |
3912 | { | |
ca86f471 | 3913 | done = synprot_error(L_smtp_syntax_error, 501, smtp_cmd_data, errmess); |
059ec3d9 PH |
3914 | break; |
3915 | } | |
3916 | ||
3917 | sender_address = raw_sender; | |
3918 | ||
3919 | /* If there is a configured size limit for mail, check that this message | |
3920 | doesn't exceed it. The check is postponed to this point so that the sender | |
3921 | can be logged. */ | |
3922 | ||
3923 | if (thismessage_size_limit > 0 && message_size > thismessage_size_limit) | |
3924 | { | |
3925 | smtp_printf("552 Message size exceeds maximum permitted\r\n"); | |
3926 | log_write(L_size_reject, | |
3927 | LOG_MAIN|LOG_REJECT, "rejected MAIL FROM:<%s> %s: " | |
3928 | "message too big: size%s=%d max=%d", | |
3929 | sender_address, | |
3930 | host_and_ident(TRUE), | |
3931 | (message_size == INT_MAX)? ">" : "", | |
3932 | message_size, | |
3933 | thismessage_size_limit); | |
3934 | sender_address = NULL; | |
3935 | break; | |
3936 | } | |
3937 | ||
3938 | /* Check there is enough space on the disk unless configured not to. | |
3939 | When smtp_check_spool_space is set, the check is for thismessage_size_limit | |
3940 | plus the current message - i.e. we accept the message only if it won't | |
3941 | reduce the space below the threshold. Add 5000 to the size to allow for | |
3942 | overheads such as the Received: line and storing of recipients, etc. | |
3943 | By putting the check here, even when SIZE is not given, it allow VRFY | |
3944 | and EXPN etc. to be used when space is short. */ | |
3945 | ||
3946 | if (!receive_check_fs( | |
3947 | (smtp_check_spool_space && message_size >= 0)? | |
3948 | message_size + 5000 : 0)) | |
3949 | { | |
3950 | smtp_printf("452 Space shortage, please try later\r\n"); | |
3951 | sender_address = NULL; | |
3952 | break; | |
3953 | } | |
3954 | ||
3955 | /* If sender_address is unqualified, reject it, unless this is a locally | |
3956 | generated message, or the sending host or net is permitted to send | |
3957 | unqualified addresses - typically local machines behaving as MUAs - | |
3958 | in which case just qualify the address. The flag is set above at the start | |
3959 | of the SMTP connection. */ | |
3960 | ||
3961 | if (sender_domain == 0 && sender_address[0] != 0) | |
3962 | { | |
3963 | if (allow_unqualified_sender) | |
3964 | { | |
3965 | sender_domain = Ustrlen(sender_address) + 1; | |
3966 | sender_address = rewrite_address_qualify(sender_address, FALSE); | |
3967 | DEBUG(D_receive) debug_printf("unqualified address %s accepted\n", | |
3968 | raw_sender); | |
3969 | } | |
3970 | else | |
3971 | { | |
3972 | smtp_printf("501 %s: sender address must contain a domain\r\n", | |
ca86f471 | 3973 | smtp_cmd_data); |
059ec3d9 PH |
3974 | log_write(L_smtp_syntax_error, |
3975 | LOG_MAIN|LOG_REJECT, | |
3976 | "unqualified sender rejected: <%s> %s%s", | |
3977 | raw_sender, | |
3978 | host_and_ident(TRUE), | |
3979 | host_lookup_msg); | |
3980 | sender_address = NULL; | |
3981 | break; | |
3982 | } | |
3983 | } | |
3984 | ||
a14e5636 PH |
3985 | /* Apply an ACL check if one is defined, before responding. Afterwards, |
3986 | when pipelining is not advertised, do another sync check in case the ACL | |
3987 | delayed and the client started sending in the meantime. */ | |
059ec3d9 | 3988 | |
a14e5636 PH |
3989 | if (acl_smtp_mail == NULL) rc = OK; else |
3990 | { | |
3991 | rc = acl_check(ACL_WHERE_MAIL, NULL, acl_smtp_mail, &user_msg, &log_msg); | |
3992 | if (rc == OK && !pipelining_advertised && !check_sync()) | |
3993 | goto SYNC_FAILURE; | |
3994 | } | |
059ec3d9 PH |
3995 | |
3996 | if (rc == OK || rc == DISCARD) | |
3997 | { | |
fd98a5c6 JH |
3998 | if (user_msg == NULL) |
3999 | smtp_printf("%s%s%s", US"250 OK", | |
4000 | #ifdef EXPERIMENTAL_PRDR | |
4001 | prdr_requested == TRUE ? US", PRDR Requested" : | |
4002 | #endif | |
4003 | US"", | |
4004 | US"\r\n"); | |
4005 | else | |
4006 | { | |
4007 | #ifdef EXPERIMENTAL_PRDR | |
4008 | if ( prdr_requested == TRUE ) | |
4009 | user_msg = string_sprintf("%s%s", user_msg, US", PRDR Requested"); | |
4010 | #endif | |
4011 | smtp_user_msg(US"250",user_msg); | |
4012 | } | |
059ec3d9 PH |
4013 | smtp_delay_rcpt = smtp_rlr_base; |
4014 | recipients_discarded = (rc == DISCARD); | |
4015 | was_rej_mail = FALSE; | |
4016 | } | |
059ec3d9 PH |
4017 | else |
4018 | { | |
4019 | done = smtp_handle_acl_fail(ACL_WHERE_MAIL, rc, user_msg, log_msg); | |
4020 | sender_address = NULL; | |
4021 | } | |
4022 | break; | |
4023 | ||
4024 | ||
2679d413 PH |
4025 | /* The RCPT command requires an address as an operand. There may be any |
4026 | number of RCPT commands, specifying multiple recipients. We build them all | |
4027 | into a data structure. The start/end values given by parse_extract_address | |
4028 | are not used, as we keep only the extracted address. */ | |
059ec3d9 PH |
4029 | |
4030 | case RCPT_CMD: | |
b4ed4da0 | 4031 | HAD(SCH_RCPT); |
059ec3d9 | 4032 | rcpt_count++; |
2679d413 | 4033 | was_rcpt = rcpt_in_progress = TRUE; |
059ec3d9 PH |
4034 | |
4035 | /* There must be a sender address; if the sender was rejected and | |
4036 | pipelining was advertised, we assume the client was pipelining, and do not | |
4037 | count this as a protocol error. Reset was_rej_mail so that further RCPTs | |
4038 | get the same treatment. */ | |
4039 | ||
4040 | if (sender_address == NULL) | |
4041 | { | |
4042 | if (pipelining_advertised && last_was_rej_mail) | |
4043 | { | |
4044 | smtp_printf("503 sender not yet given\r\n"); | |
4045 | was_rej_mail = TRUE; | |
4046 | } | |
4047 | else | |
4048 | { | |
4049 | done = synprot_error(L_smtp_protocol_error, 503, NULL, | |
4050 | US"sender not yet given"); | |
4051 | was_rcpt = FALSE; /* Not a valid RCPT */ | |
4052 | } | |
4053 | rcpt_fail_count++; | |
4054 | break; | |
4055 | } | |
4056 | ||
4057 | /* Check for an operand */ | |
4058 | ||
ca86f471 | 4059 | if (smtp_cmd_data[0] == 0) |
059ec3d9 PH |
4060 | { |
4061 | done = synprot_error(L_smtp_syntax_error, 501, NULL, | |
4062 | US"RCPT must have an address operand"); | |
4063 | rcpt_fail_count++; | |
4064 | break; | |
4065 | } | |
4066 | ||
4067 | /* Apply SMTP rewriting then extract the working address. Don't allow "<>" | |
4068 | as a recipient address */ | |
4069 | ||
4070 | recipient = ((rewrite_existflags & rewrite_smtp) != 0)? | |
ca86f471 PH |
4071 | rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"", |
4072 | global_rewrite_rules) : smtp_cmd_data; | |
059ec3d9 PH |
4073 | |
4074 | /* rfc821_domains = TRUE; << no longer needed */ | |
4075 | recipient = parse_extract_address(recipient, &errmess, &start, &end, | |
4076 | &recipient_domain, FALSE); | |
4077 | /* rfc821_domains = FALSE; << no longer needed */ | |
4078 | ||
4079 | if (recipient == NULL) | |
4080 | { | |
ca86f471 | 4081 | done = synprot_error(L_smtp_syntax_error, 501, smtp_cmd_data, errmess); |
059ec3d9 PH |
4082 | rcpt_fail_count++; |
4083 | break; | |
4084 | } | |
4085 | ||
4086 | /* If the recipient address is unqualified, reject it, unless this is a | |
4087 | locally generated message. However, unqualified addresses are permitted | |
4088 | from a configured list of hosts and nets - typically when behaving as | |
4089 | MUAs rather than MTAs. Sad that SMTP is used for both types of traffic, | |
4090 | really. The flag is set at the start of the SMTP connection. | |
4091 | ||
4092 | RFC 1123 talks about supporting "the reserved mailbox postmaster"; I always | |
4093 | assumed this meant "reserved local part", but the revision of RFC 821 and | |
4094 | friends now makes it absolutely clear that it means *mailbox*. Consequently | |
4095 | we must always qualify this address, regardless. */ | |
4096 | ||
4097 | if (recipient_domain == 0) | |
4098 | { | |
4099 | if (allow_unqualified_recipient || | |
4100 | strcmpic(recipient, US"postmaster") == 0) | |
4101 | { | |
4102 | DEBUG(D_receive) debug_printf("unqualified address %s accepted\n", | |
4103 | recipient); | |
4104 | recipient_domain = Ustrlen(recipient) + 1; | |
4105 | recipient = rewrite_address_qualify(recipient, TRUE); | |
4106 | } | |
4107 | else | |
4108 | { | |
4109 | rcpt_fail_count++; | |
4110 | smtp_printf("501 %s: recipient address must contain a domain\r\n", | |
ca86f471 | 4111 | smtp_cmd_data); |
059ec3d9 PH |
4112 | log_write(L_smtp_syntax_error, |
4113 | LOG_MAIN|LOG_REJECT, "unqualified recipient rejected: " | |
4114 | "<%s> %s%s", recipient, host_and_ident(TRUE), | |
4115 | host_lookup_msg); | |
4116 | break; | |
4117 | } | |
4118 | } | |
4119 | ||
4120 | /* Check maximum allowed */ | |
4121 | ||
4122 | if (rcpt_count > recipients_max && recipients_max > 0) | |
4123 | { | |
4124 | if (recipients_max_reject) | |
4125 | { | |
4126 | rcpt_fail_count++; | |
4127 | smtp_printf("552 too many recipients\r\n"); | |
4128 | if (!toomany) | |
4129 | log_write(0, LOG_MAIN|LOG_REJECT, "too many recipients: message " | |
4130 | "rejected: sender=<%s> %s", sender_address, host_and_ident(TRUE)); | |
4131 | } | |
4132 | else | |
4133 | { | |
4134 | rcpt_defer_count++; | |
4135 | smtp_printf("452 too many recipients\r\n"); | |
4136 | if (!toomany) | |
4137 | log_write(0, LOG_MAIN|LOG_REJECT, "too many recipients: excess " | |
4138 | "temporarily rejected: sender=<%s> %s", sender_address, | |
4139 | host_and_ident(TRUE)); | |
4140 | } | |
4141 | ||
4142 | toomany = TRUE; | |
4143 | break; | |
4144 | } | |
4145 | ||
4146 | /* If we have passed the threshold for rate limiting, apply the current | |
4147 | delay, and update it for next time, provided this is a limited host. */ | |
4148 | ||
4149 | if (rcpt_count > smtp_rlr_threshold && | |
4150 | verify_check_host(&smtp_ratelimit_hosts) == OK) | |
4151 | { | |
4152 | DEBUG(D_receive) debug_printf("rate limit RCPT: delay %.3g sec\n", | |
4153 | smtp_delay_rcpt/1000.0); | |
4154 | millisleep((int)smtp_delay_rcpt); | |
4155 | smtp_delay_rcpt *= smtp_rlr_factor; | |
4156 | if (smtp_delay_rcpt > (double)smtp_rlr_limit) | |
4157 | smtp_delay_rcpt = (double)smtp_rlr_limit; | |
4158 | } | |
4159 | ||
4160 | /* If the MAIL ACL discarded all the recipients, we bypass ACL checking | |
a14e5636 PH |
4161 | for them. Otherwise, check the access control list for this recipient. As |
4162 | there may be a delay in this, re-check for a synchronization error | |
4163 | afterwards, unless pipelining was advertised. */ | |
059ec3d9 | 4164 | |
a14e5636 PH |
4165 | if (recipients_discarded) rc = DISCARD; else |
4166 | { | |
4167 | rc = acl_check(ACL_WHERE_RCPT, recipient, acl_smtp_rcpt, &user_msg, | |
4168 | &log_msg); | |
4169 | if (rc == OK && !pipelining_advertised && !check_sync()) | |
4170 | goto SYNC_FAILURE; | |
4171 | } | |
059ec3d9 PH |
4172 | |
4173 | /* The ACL was happy */ | |
4174 | ||
4175 | if (rc == OK) | |
4176 | { | |
4e88a19f PH |
4177 | if (user_msg == NULL) smtp_printf("250 Accepted\r\n"); |
4178 | else smtp_user_msg(US"250", user_msg); | |
059ec3d9 PH |
4179 | receive_add_recipient(recipient, -1); |
4180 | } | |
4181 | ||
4182 | /* The recipient was discarded */ | |
4183 | ||
4184 | else if (rc == DISCARD) | |
4185 | { | |
4e88a19f PH |
4186 | if (user_msg == NULL) smtp_printf("250 Accepted\r\n"); |
4187 | else smtp_user_msg(US"250", user_msg); | |
059ec3d9 PH |
4188 | rcpt_fail_count++; |
4189 | discarded = TRUE; | |
4190 | log_write(0, LOG_MAIN|LOG_REJECT, "%s F=<%s> rejected RCPT %s: " | |
4191 | "discarded by %s ACL%s%s", host_and_ident(TRUE), | |
4192 | (sender_address_unrewritten != NULL)? | |
4193 | sender_address_unrewritten : sender_address, | |
3ee512ff | 4194 | smtp_cmd_argument, recipients_discarded? "MAIL" : "RCPT", |
059ec3d9 PH |
4195 | (log_msg == NULL)? US"" : US": ", |
4196 | (log_msg == NULL)? US"" : log_msg); | |
4197 | } | |
4198 | ||
4199 | /* Either the ACL failed the address, or it was deferred. */ | |
4200 | ||
4201 | else | |
4202 | { | |
4203 | if (rc == FAIL) rcpt_fail_count++; else rcpt_defer_count++; | |
4204 | done = smtp_handle_acl_fail(ACL_WHERE_RCPT, rc, user_msg, log_msg); | |
4205 | } | |
4206 | break; | |
4207 | ||
4208 | ||
4209 | /* The DATA command is legal only if it follows successful MAIL FROM | |
4210 | and RCPT TO commands. However, if pipelining is advertised, a bad DATA is | |
4211 | not counted as a protocol error if it follows RCPT (which must have been | |
4212 | rejected if there are no recipients.) This function is complete when a | |
4213 | valid DATA command is encountered. | |
4214 | ||
4215 | Note concerning the code used: RFC 2821 says this: | |
4216 | ||
4217 | - If there was no MAIL, or no RCPT, command, or all such commands | |
4218 | were rejected, the server MAY return a "command out of sequence" | |
4219 | (503) or "no valid recipients" (554) reply in response to the | |
4220 | DATA command. | |
4221 | ||
4222 | The example in the pipelining RFC 2920 uses 554, but I use 503 here | |
2679d413 PH |
4223 | because it is the same whether pipelining is in use or not. |
4224 | ||
4225 | If all the RCPT commands that precede DATA provoked the same error message | |
4226 | (often indicating some kind of system error), it is helpful to include it | |
4227 | with the DATA rejection (an idea suggested by Tony Finch). */ | |
059ec3d9 PH |
4228 | |
4229 | case DATA_CMD: | |
b4ed4da0 | 4230 | HAD(SCH_DATA); |
059ec3d9 PH |
4231 | if (!discarded && recipients_count <= 0) |
4232 | { | |
2679d413 PH |
4233 | if (rcpt_smtp_response_same && rcpt_smtp_response != NULL) |
4234 | { | |
4235 | uschar *code = US"503"; | |
4236 | int len = Ustrlen(rcpt_smtp_response); | |
4237 | smtp_respond(code, 3, FALSE, US"All RCPT commands were rejected with " | |
4238 | "this error:"); | |
4239 | /* Responses from smtp_printf() will have \r\n on the end */ | |
4240 | if (len > 2 && rcpt_smtp_response[len-2] == '\r') | |
4241 | rcpt_smtp_response[len-2] = 0; | |
4242 | smtp_respond(code, 3, FALSE, rcpt_smtp_response); | |
4243 | } | |
059ec3d9 | 4244 | if (pipelining_advertised && last_was_rcpt) |
2679d413 | 4245 | smtp_printf("503 Valid RCPT command must precede DATA\r\n"); |
059ec3d9 PH |
4246 | else |
4247 | done = synprot_error(L_smtp_protocol_error, 503, NULL, | |
4248 | US"valid RCPT command must precede DATA"); | |
4249 | break; | |
4250 | } | |
4251 | ||
4252 | if (toomany && recipients_max_reject) | |
4253 | { | |
4254 | sender_address = NULL; /* This will allow a new MAIL without RSET */ | |
4255 | sender_address_unrewritten = NULL; | |
4256 | smtp_printf("554 Too many recipients\r\n"); | |
4257 | break; | |
4258 | } | |
8e669ac1 | 4259 | |
a14e5636 | 4260 | /* If there is an ACL, re-check the synchronization afterwards, since the |
528fde2a JH |
4261 | ACL may have delayed. To handle cutthrough delivery enforce a dummy call |
4262 | to get the DATA command sent. */ | |
a14e5636 | 4263 | |
528fde2a | 4264 | if (acl_smtp_predata == NULL && cutthrough_fd < 0) rc = OK; else |
8e669ac1 | 4265 | { |
528fde2a | 4266 | uschar * acl= acl_smtp_predata ? acl_smtp_predata : US"accept"; |
5be20824 | 4267 | enable_dollar_recipients = TRUE; |
528fde2a | 4268 | rc = acl_check(ACL_WHERE_PREDATA, NULL, acl, &user_msg, |
5be20824 PH |
4269 | &log_msg); |
4270 | enable_dollar_recipients = FALSE; | |
a14e5636 | 4271 | if (rc == OK && !check_sync()) goto SYNC_FAILURE; |
5be20824 | 4272 | } |
059ec3d9 PH |
4273 | |
4274 | if (rc == OK) | |
4275 | { | |
fd98a5c6 JH |
4276 | uschar * code; |
4277 | code = US"354"; | |
4e88a19f | 4278 | if (user_msg == NULL) |
fd98a5c6 JH |
4279 | smtp_printf("%s Enter message, ending with \".\" on a line by itself\r\n", code); |
4280 | else smtp_user_msg(code, user_msg); | |
059ec3d9 PH |
4281 | done = 3; |
4282 | message_ended = END_NOTENDED; /* Indicate in middle of data */ | |
4283 | } | |
4284 | ||
4285 | /* Either the ACL failed the address, or it was deferred. */ | |
4286 | ||
4287 | else | |
4288 | done = smtp_handle_acl_fail(ACL_WHERE_PREDATA, rc, user_msg, log_msg); | |
059ec3d9 PH |
4289 | break; |
4290 | ||
4291 | ||
4292 | case VRFY_CMD: | |
b4ed4da0 | 4293 | HAD(SCH_VRFY); |
64ffc24f | 4294 | rc = acl_check(ACL_WHERE_VRFY, NULL, acl_smtp_vrfy, &user_msg, &log_msg); |
059ec3d9 PH |
4295 | if (rc != OK) |
4296 | done = smtp_handle_acl_fail(ACL_WHERE_VRFY, rc, user_msg, log_msg); | |
4297 | else | |
4298 | { | |
4299 | uschar *address; | |
4300 | uschar *s = NULL; | |
4301 | ||
4302 | /* rfc821_domains = TRUE; << no longer needed */ | |
ca86f471 | 4303 | address = parse_extract_address(smtp_cmd_data, &errmess, &start, &end, |
059ec3d9 PH |
4304 | &recipient_domain, FALSE); |
4305 | /* rfc821_domains = FALSE; << no longer needed */ | |
4306 | ||
4307 | if (address == NULL) | |
4308 | s = string_sprintf("501 %s", errmess); | |
4309 | else | |
4310 | { | |
4311 | address_item *addr = deliver_make_addr(address, FALSE); | |
4312 | switch(verify_address(addr, NULL, vopt_is_recipient | vopt_qualify, -1, | |
4deaf07d | 4313 | -1, -1, NULL, NULL, NULL)) |
059ec3d9 PH |
4314 | { |
4315 | case OK: | |
4316 | s = string_sprintf("250 <%s> is deliverable", address); | |
4317 | break; | |
4318 | ||
4319 | case DEFER: | |
81e509d7 PH |
4320 | s = (addr->user_message != NULL)? |
4321 | string_sprintf("451 <%s> %s", address, addr->user_message) : | |
059ec3d9 PH |
4322 | string_sprintf("451 Cannot resolve <%s> at this time", address); |
4323 | break; | |
4324 | ||
4325 | case FAIL: | |
81e509d7 PH |
4326 | s = (addr->user_message != NULL)? |
4327 | string_sprintf("550 <%s> %s", address, addr->user_message) : | |
059ec3d9 PH |
4328 | string_sprintf("550 <%s> is not deliverable", address); |
4329 | log_write(0, LOG_MAIN, "VRFY failed for %s %s", | |
3ee512ff | 4330 | smtp_cmd_argument, host_and_ident(TRUE)); |
059ec3d9 PH |
4331 | break; |
4332 | } | |
4333 | } | |
4334 | ||
4335 | smtp_printf("%s\r\n", s); | |
4336 | } | |
4337 | break; | |
4338 | ||
4339 | ||
4340 | case EXPN_CMD: | |
b4ed4da0 | 4341 | HAD(SCH_EXPN); |
64ffc24f | 4342 | rc = acl_check(ACL_WHERE_EXPN, NULL, acl_smtp_expn, &user_msg, &log_msg); |
059ec3d9 PH |
4343 | if (rc != OK) |
4344 | done = smtp_handle_acl_fail(ACL_WHERE_EXPN, rc, user_msg, log_msg); | |
4345 | else | |
4346 | { | |
4347 | BOOL save_log_testing_mode = log_testing_mode; | |
4348 | address_test_mode = log_testing_mode = TRUE; | |
ca86f471 | 4349 | (void) verify_address(deliver_make_addr(smtp_cmd_data, FALSE), |
64ffc24f PH |
4350 | smtp_out, vopt_is_recipient | vopt_qualify | vopt_expn, -1, -1, -1, |
4351 | NULL, NULL, NULL); | |
059ec3d9 PH |
4352 | address_test_mode = FALSE; |
4353 | log_testing_mode = save_log_testing_mode; /* true for -bh */ | |
4354 | } | |
4355 | break; | |
4356 | ||
4357 | ||
4358 | #ifdef SUPPORT_TLS | |
4359 | ||
4360 | case STARTTLS_CMD: | |
b4ed4da0 | 4361 | HAD(SCH_STARTTLS); |
059ec3d9 PH |
4362 | if (!tls_advertised) |
4363 | { | |
4364 | done = synprot_error(L_smtp_protocol_error, 503, NULL, | |
4365 | US"STARTTLS command used when not advertised"); | |
4366 | break; | |
4367 | } | |
4368 | ||
4369 | /* Apply an ACL check if one is defined */ | |
4370 | ||
4371 | if (acl_smtp_starttls != NULL) | |
4372 | { | |
4373 | rc = acl_check(ACL_WHERE_STARTTLS, NULL, acl_smtp_starttls, &user_msg, | |
4374 | &log_msg); | |
4375 | if (rc != OK) | |
4376 | { | |
4377 | done = smtp_handle_acl_fail(ACL_WHERE_STARTTLS, rc, user_msg, log_msg); | |
4378 | break; | |
4379 | } | |
4380 | } | |
4381 | ||
4382 | /* RFC 2487 is not clear on when this command may be sent, though it | |
4383 | does state that all information previously obtained from the client | |
4384 | must be discarded if a TLS session is started. It seems reasonble to | |
4385 | do an implied RSET when STARTTLS is received. */ | |
4386 | ||
4387 | incomplete_transaction_log(US"STARTTLS"); | |
4388 | smtp_reset(reset_point); | |
4389 | toomany = FALSE; | |
4390 | cmd_list[CMD_LIST_STARTTLS].is_mail_cmd = FALSE; | |
4391 | ||
da80c2a8 PP |
4392 | /* There's an attack where more data is read in past the STARTTLS command |
4393 | before TLS is negotiated, then assumed to be part of the secure session | |
4394 | when used afterwards; we use segregated input buffers, so are not | |
4395 | vulnerable, but we want to note when it happens and, for sheer paranoia, | |
4396 | ensure that the buffer is "wiped". | |
4397 | Pipelining sync checks will normally have protected us too, unless disabled | |
4398 | by configuration. */ | |
4399 | ||
4400 | if (receive_smtp_buffered()) | |
4401 | { | |
4402 | DEBUG(D_any) | |
4403 | debug_printf("Non-empty input buffer after STARTTLS; naive attack?"); | |
817d9f57 | 4404 | if (tls_in.active < 0) |
da80c2a8 PP |
4405 | smtp_inend = smtp_inptr = smtp_inbuffer; |
4406 | /* and if TLS is already active, tls_server_start() should fail */ | |
4407 | } | |
4408 | ||
4e7ee012 PP |
4409 | /* There is nothing we value in the input buffer and if TLS is succesfully |
4410 | negotiated, we won't use this buffer again; if TLS fails, we'll just read | |
4411 | fresh content into it. The buffer contains arbitrary content from an | |
4412 | untrusted remote source; eg: NOOP <shellcode>\r\nSTARTTLS\r\n | |
4413 | It seems safest to just wipe away the content rather than leave it as a | |
4414 | target to jump to. */ | |
4415 | ||
4416 | memset(smtp_inbuffer, 0, in_buffer_size); | |
4417 | ||
059ec3d9 PH |
4418 | /* Attempt to start up a TLS session, and if successful, discard all |
4419 | knowledge that was obtained previously. At least, that's what the RFC says, | |
4420 | and that's what happens by default. However, in order to work round YAEB, | |
4421 | there is an option to remember the esmtp state. Sigh. | |
4422 | ||
4423 | We must allow for an extra EHLO command and an extra AUTH command after | |
4424 | STARTTLS that don't add to the nonmail command count. */ | |
4425 | ||
17c76198 | 4426 | if ((rc = tls_server_start(tls_require_ciphers)) == OK) |
059ec3d9 PH |
4427 | { |
4428 | if (!tls_remember_esmtp) | |
4429 | helo_seen = esmtp = auth_advertised = pipelining_advertised = FALSE; | |
4430 | cmd_list[CMD_LIST_EHLO].is_mail_cmd = TRUE; | |
4431 | cmd_list[CMD_LIST_AUTH].is_mail_cmd = TRUE; | |
4432 | if (sender_helo_name != NULL) | |
4433 | { | |
4434 | store_free(sender_helo_name); | |
4435 | sender_helo_name = NULL; | |
4436 | host_build_sender_fullhost(); /* Rebuild */ | |
4437 | set_process_info("handling incoming TLS connection from %s", | |
4438 | host_and_ident(FALSE)); | |
4439 | } | |
4440 | received_protocol = (esmtp? | |
4441 | protocols[pextend + pcrpted + | |
4442 | ((sender_host_authenticated != NULL)? pauthed : 0)] | |
4443 | : | |
981756db | 4444 | protocols[pnormal + pcrpted]) |
059ec3d9 PH |
4445 | + |
4446 | ((sender_host_address != NULL)? pnlocal : 0); | |
4447 | ||
4448 | sender_host_authenticated = NULL; | |
4449 | authenticated_id = NULL; | |
4450 | sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING; | |
4451 | DEBUG(D_tls) debug_printf("TLS active\n"); | |
4452 | break; /* Successful STARTTLS */ | |
4453 | } | |
4454 | ||
4455 | /* Some local configuration problem was discovered before actually trying | |
4456 | to do a TLS handshake; give a temporary error. */ | |
4457 | ||
4458 | else if (rc == DEFER) | |
4459 | { | |
4460 | smtp_printf("454 TLS currently unavailable\r\n"); | |
4461 | break; | |
4462 | } | |
4463 | ||
4464 | /* Hard failure. Reject everything except QUIT or closed connection. One | |
817d9f57 | 4465 | cause for failure is a nested STARTTLS, in which case tls_in.active remains |
059ec3d9 PH |
4466 | set, but we must still reject all incoming commands. */ |
4467 | ||
4468 | DEBUG(D_tls) debug_printf("TLS failed to start\n"); | |
4469 | while (done <= 0) | |
4470 | { | |
4471 | switch(smtp_read_command(FALSE)) | |
4472 | { | |
4473 | case EOF_CMD: | |
4474 | log_write(L_smtp_connection, LOG_MAIN, "%s closed by EOF", | |
4475 | smtp_get_connection_info()); | |
8f128379 | 4476 | smtp_notquit_exit(US"tls-failed", NULL, NULL); |
059ec3d9 PH |
4477 | done = 2; |
4478 | break; | |
4479 | ||
8f128379 | 4480 | /* It is perhaps arguable as to which exit ACL should be called here, |
24f66b4d | 4481 | but as it is probably a situation that almost never arises, it |
8f128379 PH |
4482 | probably doesn't matter. We choose to call the real QUIT ACL, which in |
4483 | some sense is perhaps "right". */ | |
4484 | ||
059ec3d9 | 4485 | case QUIT_CMD: |
8f128379 PH |
4486 | user_msg = NULL; |
4487 | if (acl_smtp_quit != NULL) | |
4488 | { | |
4489 | rc = acl_check(ACL_WHERE_QUIT, NULL, acl_smtp_quit, &user_msg, | |
4490 | &log_msg); | |
4491 | if (rc == ERROR) | |
4492 | log_write(0, LOG_MAIN|LOG_PANIC, "ACL for QUIT returned ERROR: %s", | |
4493 | log_msg); | |
4494 | } | |
4495 | if (user_msg == NULL) | |
4496 | smtp_printf("221 %s closing connection\r\n", smtp_active_hostname); | |
4497 | else | |
4498 | smtp_respond(US"221", 3, TRUE, user_msg); | |
059ec3d9 PH |
4499 | log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT", |
4500 | smtp_get_connection_info()); | |
4501 | done = 2; | |
4502 | break; | |
4503 | ||
4504 | default: | |
4505 | smtp_printf("554 Security failure\r\n"); | |
4506 | break; | |
4507 | } | |
4508 | } | |
817d9f57 | 4509 | tls_close(TRUE, TRUE); |
059ec3d9 PH |
4510 | break; |
4511 | #endif | |
4512 | ||
4513 | ||
4514 | /* The ACL for QUIT is provided for gathering statistical information or | |
4515 | similar; it does not affect the response code, but it can supply a custom | |
4516 | message. */ | |
4517 | ||
4518 | case QUIT_CMD: | |
b4ed4da0 | 4519 | HAD(SCH_QUIT); |
059ec3d9 | 4520 | incomplete_transaction_log(US"QUIT"); |
059ec3d9 PH |
4521 | if (acl_smtp_quit != NULL) |
4522 | { | |
8f128379 | 4523 | rc = acl_check(ACL_WHERE_QUIT, NULL, acl_smtp_quit, &user_msg, &log_msg); |
059ec3d9 PH |
4524 | if (rc == ERROR) |
4525 | log_write(0, LOG_MAIN|LOG_PANIC, "ACL for QUIT returned ERROR: %s", | |
4526 | log_msg); | |
4527 | } | |
059ec3d9 PH |
4528 | if (user_msg == NULL) |
4529 | smtp_printf("221 %s closing connection\r\n", smtp_active_hostname); | |
4530 | else | |
4e88a19f | 4531 | smtp_respond(US"221", 3, TRUE, user_msg); |
059ec3d9 PH |
4532 | |
4533 | #ifdef SUPPORT_TLS | |
817d9f57 | 4534 | tls_close(TRUE, TRUE); |
059ec3d9 PH |
4535 | #endif |
4536 | ||
4537 | done = 2; | |
4538 | log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT", | |
4539 | smtp_get_connection_info()); | |
4540 | break; | |
4541 | ||
4542 | ||
4543 | case RSET_CMD: | |
b4ed4da0 | 4544 | HAD(SCH_RSET); |
059ec3d9 PH |
4545 | incomplete_transaction_log(US"RSET"); |
4546 | smtp_reset(reset_point); | |
4547 | toomany = FALSE; | |
4548 | smtp_printf("250 Reset OK\r\n"); | |
4549 | cmd_list[CMD_LIST_RSET].is_mail_cmd = FALSE; | |
4550 | break; | |
4551 | ||
4552 | ||
4553 | case NOOP_CMD: | |
b4ed4da0 | 4554 | HAD(SCH_NOOP); |
059ec3d9 PH |
4555 | smtp_printf("250 OK\r\n"); |
4556 | break; | |
4557 | ||
4558 | ||
b43a74ea PH |
4559 | /* Show ETRN/EXPN/VRFY if there's an ACL for checking hosts; if actually |
4560 | used, a check will be done for permitted hosts. Show STARTTLS only if not | |
4561 | already in a TLS session and if it would be advertised in the EHLO | |
4562 | response. */ | |
059ec3d9 PH |
4563 | |
4564 | case HELP_CMD: | |
b4ed4da0 | 4565 | HAD(SCH_HELP); |
059ec3d9 PH |
4566 | smtp_printf("214-Commands supported:\r\n"); |
4567 | { | |
4568 | uschar buffer[256]; | |
4569 | buffer[0] = 0; | |
4570 | Ustrcat(buffer, " AUTH"); | |
4571 | #ifdef SUPPORT_TLS | |
817d9f57 | 4572 | if (tls_in.active < 0 && |
b43a74ea PH |
4573 | verify_check_host(&tls_advertise_hosts) != FAIL) |
4574 | Ustrcat(buffer, " STARTTLS"); | |
059ec3d9 PH |
4575 | #endif |
4576 | Ustrcat(buffer, " HELO EHLO MAIL RCPT DATA"); | |
4577 | Ustrcat(buffer, " NOOP QUIT RSET HELP"); | |
4578 | if (acl_smtp_etrn != NULL) Ustrcat(buffer, " ETRN"); | |
4579 | if (acl_smtp_expn != NULL) Ustrcat(buffer, " EXPN"); | |
4580 | if (acl_smtp_vrfy != NULL) Ustrcat(buffer, " VRFY"); | |
4581 | smtp_printf("214%s\r\n", buffer); | |
4582 | } | |
4583 | break; | |
4584 | ||
4585 | ||
4586 | case EOF_CMD: | |
4587 | incomplete_transaction_log(US"connection lost"); | |
8f128379 PH |
4588 | smtp_notquit_exit(US"connection-lost", US"421", |
4589 | US"%s lost input connection", smtp_active_hostname); | |
059ec3d9 PH |
4590 | |
4591 | /* Don't log by default unless in the middle of a message, as some mailers | |
4592 | just drop the call rather than sending QUIT, and it clutters up the logs. | |
4593 | */ | |
4594 | ||
4595 | if (sender_address != NULL || recipients_count > 0) | |
4596 | log_write(L_lost_incoming_connection, | |
4597 | LOG_MAIN, | |
4598 | "unexpected %s while reading SMTP command from %s%s", | |
4599 | sender_host_unknown? "EOF" : "disconnection", | |
4600 | host_and_ident(FALSE), smtp_read_error); | |
4601 | ||
4602 | else log_write(L_smtp_connection, LOG_MAIN, "%s lost%s", | |
4603 | smtp_get_connection_info(), smtp_read_error); | |
4604 | ||
4605 | done = 1; | |
4606 | break; | |
4607 | ||
4608 | ||
4609 | case ETRN_CMD: | |
b4ed4da0 | 4610 | HAD(SCH_ETRN); |
059ec3d9 PH |
4611 | if (sender_address != NULL) |
4612 | { | |
4613 | done = synprot_error(L_smtp_protocol_error, 503, NULL, | |
4614 | US"ETRN is not permitted inside a transaction"); | |
4615 | break; | |
4616 | } | |
4617 | ||
3ee512ff | 4618 | log_write(L_etrn, LOG_MAIN, "ETRN %s received from %s", smtp_cmd_argument, |
059ec3d9 PH |
4619 | host_and_ident(FALSE)); |
4620 | ||
64ffc24f | 4621 | rc = acl_check(ACL_WHERE_ETRN, NULL, acl_smtp_etrn, &user_msg, &log_msg); |
059ec3d9 PH |
4622 | if (rc != OK) |
4623 | { | |
4624 | done = smtp_handle_acl_fail(ACL_WHERE_ETRN, rc, user_msg, log_msg); | |
4625 | break; | |
4626 | } | |
4627 | ||
4628 | /* Compute the serialization key for this command. */ | |
4629 | ||
ca86f471 | 4630 | etrn_serialize_key = string_sprintf("etrn-%s\n", smtp_cmd_data); |
059ec3d9 PH |
4631 | |
4632 | /* If a command has been specified for running as a result of ETRN, we | |
4633 | permit any argument to ETRN. If not, only the # standard form is permitted, | |
4634 | since that is strictly the only kind of ETRN that can be implemented | |
4635 | according to the RFC. */ | |
4636 | ||
4637 | if (smtp_etrn_command != NULL) | |
4638 | { | |
4639 | uschar *error; | |
4640 | BOOL rc; | |
4641 | etrn_command = smtp_etrn_command; | |
ca86f471 | 4642 | deliver_domain = smtp_cmd_data; |
059ec3d9 PH |
4643 | rc = transport_set_up_command(&argv, smtp_etrn_command, TRUE, 0, NULL, |
4644 | US"ETRN processing", &error); | |
4645 | deliver_domain = NULL; | |
4646 | if (!rc) | |
4647 | { | |
4648 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to set up ETRN command: %s", | |
4649 | error); | |
4650 | smtp_printf("458 Internal failure\r\n"); | |
4651 | break; | |
4652 | } | |
4653 | } | |
4654 | ||
4655 | /* Else set up to call Exim with the -R option. */ | |
4656 | ||
4657 | else | |
4658 | { | |
ca86f471 | 4659 | if (*smtp_cmd_data++ != '#') |
059ec3d9 PH |
4660 | { |
4661 | done = synprot_error(L_smtp_syntax_error, 501, NULL, | |
4662 | US"argument must begin with #"); | |
4663 | break; | |
4664 | } | |
4665 | etrn_command = US"exim -R"; | |
4666 | argv = child_exec_exim(CEE_RETURN_ARGV, TRUE, NULL, TRUE, 2, US"-R", | |
ca86f471 | 4667 | smtp_cmd_data); |
059ec3d9 PH |
4668 | } |
4669 | ||
4670 | /* If we are host-testing, don't actually do anything. */ | |
4671 | ||
4672 | if (host_checking) | |
4673 | { | |
4674 | HDEBUG(D_any) | |
4675 | { | |
4676 | debug_printf("ETRN command is: %s\n", etrn_command); | |
4677 | debug_printf("ETRN command execution skipped\n"); | |
4678 | } | |
4e88a19f PH |
4679 | if (user_msg == NULL) smtp_printf("250 OK\r\n"); |
4680 | else smtp_user_msg(US"250", user_msg); | |
059ec3d9 PH |
4681 | break; |
4682 | } | |
4683 | ||
4684 | ||
4685 | /* If ETRN queue runs are to be serialized, check the database to | |
4686 | ensure one isn't already running. */ | |
4687 | ||
4688 | if (smtp_etrn_serialize && !enq_start(etrn_serialize_key)) | |
4689 | { | |
ca86f471 | 4690 | smtp_printf("458 Already processing %s\r\n", smtp_cmd_data); |
059ec3d9 PH |
4691 | break; |
4692 | } | |
4693 | ||
4694 | /* Fork a child process and run the command. We don't want to have to | |
4695 | wait for the process at any point, so set SIGCHLD to SIG_IGN before | |
4696 | forking. It should be set that way anyway for external incoming SMTP, | |
4697 | but we save and restore to be tidy. If serialization is required, we | |
4698 | actually run the command in yet another process, so we can wait for it | |
4699 | to complete and then remove the serialization lock. */ | |
4700 | ||
4701 | oldsignal = signal(SIGCHLD, SIG_IGN); | |
4702 | ||
4703 | if ((pid = fork()) == 0) | |
4704 | { | |
f1e894f3 PH |
4705 | smtp_input = FALSE; /* This process is not associated with the */ |
4706 | (void)fclose(smtp_in); /* SMTP call any more. */ | |
4707 | (void)fclose(smtp_out); | |
059ec3d9 PH |
4708 | |
4709 | signal(SIGCHLD, SIG_DFL); /* Want to catch child */ | |
4710 | ||
4711 | /* If not serializing, do the exec right away. Otherwise, fork down | |
4712 | into another process. */ | |
4713 | ||
4714 | if (!smtp_etrn_serialize || (pid = fork()) == 0) | |
4715 | { | |
4716 | DEBUG(D_exec) debug_print_argv(argv); | |
4717 | exim_nullstd(); /* Ensure std{in,out,err} exist */ | |
4718 | execv(CS argv[0], (char *const *)argv); | |
4719 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "exec of \"%s\" (ETRN) failed: %s", | |
4720 | etrn_command, strerror(errno)); | |
4721 | _exit(EXIT_FAILURE); /* paranoia */ | |
4722 | } | |
4723 | ||
4724 | /* Obey this if smtp_serialize and the 2nd fork yielded non-zero. That | |
4725 | is, we are in the first subprocess, after forking again. All we can do | |
4726 | for a failing fork is to log it. Otherwise, wait for the 2nd process to | |
4727 | complete, before removing the serialization. */ | |
4728 | ||
4729 | if (pid < 0) | |
4730 | log_write(0, LOG_MAIN|LOG_PANIC, "2nd fork for serialized ETRN " | |
4731 | "failed: %s", strerror(errno)); | |
4732 | else | |
4733 | { | |
4734 | int status; | |
4735 | DEBUG(D_any) debug_printf("waiting for serialized ETRN process %d\n", | |
4736 | (int)pid); | |
4737 | (void)wait(&status); | |
4738 | DEBUG(D_any) debug_printf("serialized ETRN process %d ended\n", | |
4739 | (int)pid); | |
4740 | } | |
4741 | ||
4742 | enq_end(etrn_serialize_key); | |
4743 | _exit(EXIT_SUCCESS); | |
4744 | } | |
4745 | ||
4746 | /* Back in the top level SMTP process. Check that we started a subprocess | |
4747 | and restore the signal state. */ | |
4748 | ||
4749 | if (pid < 0) | |
4750 | { | |
4751 | log_write(0, LOG_MAIN|LOG_PANIC, "fork of process for ETRN failed: %s", | |
4752 | strerror(errno)); | |
4753 | smtp_printf("458 Unable to fork process\r\n"); | |
4754 | if (smtp_etrn_serialize) enq_end(etrn_serialize_key); | |
4755 | } | |
4e88a19f PH |
4756 | else |
4757 | { | |
4758 | if (user_msg == NULL) smtp_printf("250 OK\r\n"); | |
4759 | else smtp_user_msg(US"250", user_msg); | |
4760 | } | |
059ec3d9 PH |
4761 | |
4762 | signal(SIGCHLD, oldsignal); | |
4763 | break; | |
4764 | ||
4765 | ||
4766 | case BADARG_CMD: | |
4767 | done = synprot_error(L_smtp_syntax_error, 501, NULL, | |
4768 | US"unexpected argument data"); | |
4769 | break; | |
4770 | ||
4771 | ||
4772 | /* This currently happens only for NULLs, but could be extended. */ | |
4773 | ||
4774 | case BADCHAR_CMD: | |
4775 | done = synprot_error(L_smtp_syntax_error, 0, NULL, /* Just logs */ | |
4776 | US"NULL character(s) present (shown as '?')"); | |
4777 | smtp_printf("501 NULL characters are not allowed in SMTP commands\r\n"); | |
4778 | break; | |
4779 | ||
4780 | ||
4781 | case BADSYN_CMD: | |
a14e5636 | 4782 | SYNC_FAILURE: |
059ec3d9 PH |
4783 | if (smtp_inend >= smtp_inbuffer + in_buffer_size) |
4784 | smtp_inend = smtp_inbuffer + in_buffer_size - 1; | |
4785 | c = smtp_inend - smtp_inptr; | |
4786 | if (c > 150) c = 150; | |
4787 | smtp_inptr[c] = 0; | |
4788 | incomplete_transaction_log(US"sync failure"); | |
3af76a81 | 4789 | log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol synchronization error " |
059ec3d9 PH |
4790 | "(next input sent too soon: pipelining was%s advertised): " |
4791 | "rejected \"%s\" %s next input=\"%s\"", | |
4792 | pipelining_advertised? "" : " not", | |
3ee512ff | 4793 | smtp_cmd_buffer, host_and_ident(TRUE), |
059ec3d9 | 4794 | string_printing(smtp_inptr)); |
8f128379 PH |
4795 | smtp_notquit_exit(US"synchronization-error", US"554", |
4796 | US"SMTP synchronization error"); | |
059ec3d9 PH |
4797 | done = 1; /* Pretend eof - drops connection */ |
4798 | break; | |
4799 | ||
4800 | ||
4801 | case TOO_MANY_NONMAIL_CMD: | |
ca86f471 PH |
4802 | s = smtp_cmd_buffer; |
4803 | while (*s != 0 && !isspace(*s)) s++; | |
059ec3d9 PH |
4804 | incomplete_transaction_log(US"too many non-mail commands"); |
4805 | log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many " | |
4806 | "nonmail commands (last was \"%.*s\")", host_and_ident(FALSE), | |
6d9cfc47 | 4807 | (int)(s - smtp_cmd_buffer), smtp_cmd_buffer); |
8f128379 | 4808 | smtp_notquit_exit(US"bad-commands", US"554", US"Too many nonmail commands"); |
059ec3d9 PH |
4809 | done = 1; /* Pretend eof - drops connection */ |
4810 | break; | |
4811 | ||
a3c86431 TL |
4812 | #ifdef EXPERIMENTAL_PROXY |
4813 | case PROXY_FAIL_IGNORE_CMD: | |
4814 | smtp_printf("503 Command refused, required Proxy negotiation failed\r\n"); | |
4815 | break; | |
4816 | #endif | |
059ec3d9 PH |
4817 | |
4818 | default: | |
4819 | if (unknown_command_count++ >= smtp_max_unknown_commands) | |
4820 | { | |
4821 | log_write(L_smtp_syntax_error, LOG_MAIN, | |
4822 | "SMTP syntax error in \"%s\" %s %s", | |
3ee512ff | 4823 | string_printing(smtp_cmd_buffer), host_and_ident(TRUE), |
059ec3d9 PH |
4824 | US"unrecognized command"); |
4825 | incomplete_transaction_log(US"unrecognized command"); | |
8f128379 PH |
4826 | smtp_notquit_exit(US"bad-commands", US"500", |
4827 | US"Too many unrecognized commands"); | |
059ec3d9 PH |
4828 | done = 2; |
4829 | log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many " | |
4830 | "unrecognized commands (last was \"%s\")", host_and_ident(FALSE), | |
3ee512ff | 4831 | smtp_cmd_buffer); |
059ec3d9 PH |
4832 | } |
4833 | else | |
4834 | done = synprot_error(L_smtp_syntax_error, 500, NULL, | |
4835 | US"unrecognized command"); | |
4836 | break; | |
4837 | } | |
4838 | ||
4839 | /* This label is used by goto's inside loops that want to break out to | |
4840 | the end of the command-processing loop. */ | |
4841 | ||
4842 | COMMAND_LOOP: | |
4843 | last_was_rej_mail = was_rej_mail; /* Remember some last commands for */ | |
4844 | last_was_rcpt = was_rcpt; /* protocol error handling */ | |
4845 | continue; | |
4846 | } | |
4847 | ||
4848 | return done - 2; /* Convert yield values */ | |
4849 | } | |
4850 | ||
e45a1c37 JH |
4851 | /* vi: aw ai sw=2 |
4852 | */ | |
059ec3d9 | 4853 | /* End of smtp_in.c */ |