Commit | Line | Data |
---|---|---|
059ec3d9 PH |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
9242a7e8 | 5 | /* Copyright (c) University of Cambridge 1995 - 2017 */ |
059ec3d9 PH |
6 | /* See the file NOTICE for conditions of use and distribution. */ |
7 | ||
8 | /* A number of functions for driving outgoing SMTP calls. */ | |
9 | ||
10 | ||
11 | #include "exim.h" | |
7eb6c37c | 12 | #include "transports/smtp.h" |
059ec3d9 PH |
13 | |
14 | ||
15 | ||
16 | /************************************************* | |
17 | * Find an outgoing interface * | |
18 | *************************************************/ | |
19 | ||
20 | /* This function is called from the smtp transport and also from the callout | |
21 | code in verify.c. Its job is to expand a string to get a list of interfaces, | |
22 | and choose a suitable one (IPv4 or IPv6) for the outgoing address. | |
23 | ||
24 | Arguments: | |
25 | istring string interface setting, may be NULL, meaning "any", in | |
26 | which case the function does nothing | |
27 | host_af AF_INET or AF_INET6 for the outgoing IP address | |
28 | addr the mail address being handled (for setting errors) | |
059ec3d9 PH |
29 | interface point this to the interface |
30 | msg to add to any error message | |
31 | ||
32 | Returns: TRUE on success, FALSE on failure, with error message | |
33 | set in addr and transport_return set to PANIC | |
34 | */ | |
35 | ||
36 | BOOL | |
37 | smtp_get_interface(uschar *istring, int host_af, address_item *addr, | |
6f6dedcc | 38 | uschar **interface, uschar *msg) |
059ec3d9 | 39 | { |
55414b25 | 40 | const uschar * expint; |
059ec3d9 PH |
41 | uschar *iface; |
42 | int sep = 0; | |
43 | ||
fb05276a | 44 | if (!istring) return TRUE; |
059ec3d9 | 45 | |
fb05276a | 46 | if (!(expint = expand_string(istring))) |
059ec3d9 PH |
47 | { |
48 | if (expand_string_forcedfail) return TRUE; | |
49 | addr->transport_return = PANIC; | |
50 | addr->message = string_sprintf("failed to expand \"interface\" " | |
51 | "option for %s: %s", msg, expand_string_message); | |
52 | return FALSE; | |
53 | } | |
54 | ||
059ec3d9 PH |
55 | while (isspace(*expint)) expint++; |
56 | if (*expint == 0) return TRUE; | |
57 | ||
58 | while ((iface = string_nextinlist(&expint, &sep, big_buffer, | |
fb05276a | 59 | big_buffer_size))) |
059ec3d9 PH |
60 | { |
61 | if (string_is_ip_address(iface, NULL) == 0) | |
62 | { | |
63 | addr->transport_return = PANIC; | |
64 | addr->message = string_sprintf("\"%s\" is not a valid IP " | |
65 | "address for the \"interface\" option for %s", | |
66 | iface, msg); | |
67 | return FALSE; | |
68 | } | |
69 | ||
70 | if (((Ustrchr(iface, ':') == NULL)? AF_INET:AF_INET6) == host_af) | |
71 | break; | |
72 | } | |
73 | ||
fb05276a | 74 | if (iface) *interface = string_copy(iface); |
059ec3d9 PH |
75 | return TRUE; |
76 | } | |
77 | ||
78 | ||
79 | ||
80 | /************************************************* | |
81 | * Find an outgoing port * | |
82 | *************************************************/ | |
83 | ||
84 | /* This function is called from the smtp transport and also from the callout | |
85 | code in verify.c. Its job is to find a port number. Note that getservbyname() | |
86 | produces the number in network byte order. | |
87 | ||
88 | Arguments: | |
89 | rstring raw (unexpanded) string representation of the port | |
90 | addr the mail address being handled (for setting errors) | |
91 | port stick the port in here | |
92 | msg for adding to error message | |
93 | ||
94 | Returns: TRUE on success, FALSE on failure, with error message set | |
95 | in addr, and transport_return set to PANIC | |
96 | */ | |
97 | ||
98 | BOOL | |
99 | smtp_get_port(uschar *rstring, address_item *addr, int *port, uschar *msg) | |
100 | { | |
101 | uschar *pstring = expand_string(rstring); | |
102 | ||
00580051 | 103 | if (!pstring) |
059ec3d9 PH |
104 | { |
105 | addr->transport_return = PANIC; | |
106 | addr->message = string_sprintf("failed to expand \"%s\" (\"port\" option) " | |
107 | "for %s: %s", rstring, msg, expand_string_message); | |
108 | return FALSE; | |
109 | } | |
110 | ||
111 | if (isdigit(*pstring)) | |
112 | { | |
113 | uschar *end; | |
114 | *port = Ustrtol(pstring, &end, 0); | |
115 | if (end != pstring + Ustrlen(pstring)) | |
116 | { | |
117 | addr->transport_return = PANIC; | |
118 | addr->message = string_sprintf("invalid port number for %s: %s", msg, | |
119 | pstring); | |
120 | return FALSE; | |
121 | } | |
122 | } | |
123 | ||
124 | else | |
125 | { | |
126 | struct servent *smtp_service = getservbyname(CS pstring, "tcp"); | |
00580051 | 127 | if (!smtp_service) |
059ec3d9 PH |
128 | { |
129 | addr->transport_return = PANIC; | |
130 | addr->message = string_sprintf("TCP port \"%s\" is not defined for %s", | |
131 | pstring, msg); | |
132 | return FALSE; | |
133 | } | |
134 | *port = ntohs(smtp_service->s_port); | |
135 | } | |
136 | ||
137 | return TRUE; | |
138 | } | |
139 | ||
140 | ||
141 | ||
142 | ||
1ccd5f67 JH |
143 | #ifdef TCP_FASTOPEN |
144 | static void | |
145 | tfo_out_check(int sock) | |
146 | { | |
147 | # if defined(TCP_INFO) && defined(EXIM_HAVE_TCPI_UNACKED) | |
148 | struct tcp_info tinfo; | |
149 | socklen_t len = sizeof(tinfo); | |
150 | ||
151 | if (getsockopt(sock, IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0) | |
152 | { | |
153 | switch (tcp_out_fastopen) | |
154 | { | |
155 | /* This is a somewhat dubious detection method; totally undocumented so likely | |
156 | to fail in future kernels. There seems to be no documented way. What we really | |
157 | want to know is if the server sent smtp-banner data before our ACK of his SYN,ACK | |
158 | hit him. What this (possibly?) detects is whether we sent a TFO cookie with our | |
159 | SYN, as distinct from a TFO request. This gets a false-positive when the server | |
160 | key is rotated; we send the old one (which this test sees) but the server returns | |
161 | the new one and does not send its SMTP banner before we ACK his SYN,ACK. | |
162 | To force that rotation case: | |
163 | '# echo -n "00000000-00000000-00000000-0000000" >/proc/sys/net/ipv4/tcp_fastopen_key' | |
164 | The kernel seems to be counting unack'd packets. */ | |
165 | ||
166 | case 1: | |
167 | if (tinfo.tcpi_unacked > 1) | |
168 | { | |
169 | DEBUG(D_transport|D_v) | |
170 | debug_printf("TCP_FASTOPEN tcpi_unacked %d\n", tinfo.tcpi_unacked); | |
171 | tcp_out_fastopen = 2; | |
172 | } | |
173 | break; | |
174 | ||
175 | #ifdef notdef /* This seems to always fire, meaning that we cannot tell | |
176 | whether the server accepted data we sent. For now assume | |
177 | that it did. */ | |
178 | ||
179 | /* If there was data-on-SYN but we had to retrasnmit it, declare no TFO */ | |
180 | ||
181 | case 2: | |
182 | if (!(tinfo.tcpi_options & TCPI_OPT_SYN_DATA)) | |
183 | { | |
184 | DEBUG(D_transport|D_v) debug_printf("TFO: had to retransmit\n"); | |
185 | tcp_out_fastopen = 0; | |
186 | } | |
187 | break; | |
188 | #endif | |
189 | } | |
190 | ||
191 | } | |
192 | # endif | |
193 | } | |
194 | #endif | |
195 | ||
196 | ||
0ab63f3d JH |
197 | /* Arguments as for smtp_connect(), plus |
198 | early_data if non-NULL, data to be sent - preferably in the TCP SYN segment | |
199 | ||
200 | Returns: connected socket number, or -1 with errno set | |
201 | */ | |
202 | ||
059ec3d9 | 203 | int |
7eb6c37c | 204 | smtp_sock_connect(host_item * host, int host_af, int port, uschar * interface, |
0ab63f3d | 205 | transport_instance * tb, int timeout, const blob * early_data) |
059ec3d9 | 206 | { |
7eb6c37c JH |
207 | smtp_transport_options_block * ob = |
208 | (smtp_transport_options_block *)tb->options_block; | |
209 | const uschar * dscp = ob->dscp; | |
9e4f5962 PP |
210 | int dscp_value; |
211 | int dscp_level; | |
212 | int dscp_option; | |
059ec3d9 | 213 | int sock; |
7eb6c37c | 214 | int save_errno = 0; |
10ac8d7f | 215 | const blob * fastopen_blob = NULL; |
1ccd5f67 | 216 | |
059ec3d9 | 217 | |
0cbf2b82 | 218 | #ifndef DISABLE_EVENT |
7eb6c37c JH |
219 | deliver_host_address = host->address; |
220 | deliver_host_port = port; | |
221 | if (event_raise(tb->event_action, US"tcp:connect", NULL)) return -1; | |
a7538db1 JH |
222 | #endif |
223 | ||
059ec3d9 PH |
224 | if ((sock = ip_socket(SOCK_STREAM, host_af)) < 0) return -1; |
225 | ||
226 | /* Set TCP_NODELAY; Exim does its own buffering. */ | |
227 | ||
d4ff61d1 JH |
228 | if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, US &on, sizeof(on))) |
229 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 230 | debug_printf_indent("failed to set NODELAY: %s ", strerror(errno)); |
059ec3d9 | 231 | |
9e4f5962 PP |
232 | /* Set DSCP value, if we can. For now, if we fail to set the value, we don't |
233 | bomb out, just log it and continue in default traffic class. */ | |
234 | ||
235 | if (dscp && dscp_lookup(dscp, host_af, &dscp_level, &dscp_option, &dscp_value)) | |
236 | { | |
237 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 238 | debug_printf_indent("DSCP \"%s\"=%x ", dscp, dscp_value); |
9e4f5962 PP |
239 | if (setsockopt(sock, dscp_level, dscp_option, &dscp_value, sizeof(dscp_value)) < 0) |
240 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 241 | debug_printf_indent("failed to set DSCP: %s ", strerror(errno)); |
9e4f5962 PP |
242 | /* If the kernel supports IPv4 and IPv6 on an IPv6 socket, we need to set the |
243 | option for both; ignore failures here */ | |
244 | if (host_af == AF_INET6 && | |
245 | dscp_lookup(dscp, AF_INET, &dscp_level, &dscp_option, &dscp_value)) | |
9e4f5962 | 246 | (void) setsockopt(sock, dscp_level, dscp_option, &dscp_value, sizeof(dscp_value)); |
9e4f5962 PP |
247 | } |
248 | ||
059ec3d9 PH |
249 | /* Bind to a specific interface if requested. Caller must ensure the interface |
250 | is the same type (IPv4 or IPv6) as the outgoing address. */ | |
251 | ||
7eb6c37c | 252 | if (interface && ip_bind(sock, host_af, interface, 0) < 0) |
059ec3d9 PH |
253 | { |
254 | save_errno = errno; | |
255 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 256 | debug_printf_indent("unable to bind outgoing SMTP call to %s: %s", interface, |
059ec3d9 PH |
257 | strerror(errno)); |
258 | } | |
259 | ||
260 | /* Connect to the remote host, and add keepalive to the socket before returning | |
0ab63f3d JH |
261 | it, if requested. If the build supports TFO, request it - and if the caller |
262 | requested some early-data then include that in the TFO request. */ | |
059ec3d9 | 263 | |
0ab63f3d JH |
264 | else |
265 | { | |
0ab63f3d JH |
266 | #ifdef TCP_FASTOPEN |
267 | if (verify_check_given_host(&ob->hosts_try_fastopen, host) == OK) | |
10ac8d7f | 268 | fastopen_blob = early_data ? early_data : &tcp_fastopen_nodata; |
0ab63f3d JH |
269 | #endif |
270 | ||
10ac8d7f | 271 | if (ip_connect(sock, host_af, host->address, port, timeout, fastopen_blob) < 0) |
0ab63f3d | 272 | save_errno = errno; |
10ac8d7f | 273 | else if (early_data && !fastopen_blob && early_data->data && early_data->len) |
0ab63f3d JH |
274 | if (send(sock, early_data->data, early_data->len, 0) < 0) |
275 | save_errno = errno; | |
276 | } | |
059ec3d9 PH |
277 | |
278 | /* Either bind() or connect() failed */ | |
279 | ||
280 | if (save_errno != 0) | |
281 | { | |
8e669ac1 | 282 | HDEBUG(D_transport|D_acl|D_v) |
4deaf07d | 283 | { |
e1d04f48 | 284 | debug_printf_indent("failed: %s", CUstrerror(save_errno)); |
8e669ac1 | 285 | if (save_errno == ETIMEDOUT) |
4deaf07d | 286 | debug_printf(" (timeout=%s)", readconf_printtime(timeout)); |
8e669ac1 PH |
287 | debug_printf("\n"); |
288 | } | |
f1e894f3 | 289 | (void)close(sock); |
059ec3d9 PH |
290 | errno = save_errno; |
291 | return -1; | |
292 | } | |
293 | ||
294 | /* Both bind() and connect() succeeded */ | |
295 | ||
296 | else | |
297 | { | |
41c7c167 PH |
298 | union sockaddr_46 interface_sock; |
299 | EXIM_SOCKLEN_T size = sizeof(interface_sock); | |
e1d04f48 | 300 | HDEBUG(D_transport|D_acl|D_v) debug_printf_indent("connected\n"); |
41c7c167 PH |
301 | if (getsockname(sock, (struct sockaddr *)(&interface_sock), &size) == 0) |
302 | sending_ip_address = host_ntoa(-1, &interface_sock, NULL, &sending_port); | |
303 | else | |
304 | { | |
305 | log_write(0, LOG_MAIN | ((errno == ECONNRESET)? 0 : LOG_PANIC), | |
306 | "getsockname() failed: %s", strerror(errno)); | |
307 | close(sock); | |
308 | return -1; | |
309 | } | |
7eb6c37c | 310 | if (ob->keepalive) ip_keepalive(sock, host->address, TRUE); |
1ccd5f67 | 311 | #ifdef TCP_FASTOPEN |
10ac8d7f | 312 | if (fastopen_blob) tfo_out_check(sock); |
1ccd5f67 | 313 | #endif |
059ec3d9 PH |
314 | return sock; |
315 | } | |
316 | } | |
317 | ||
58c30e47 JH |
318 | |
319 | ||
320 | ||
321 | ||
322 | void | |
323 | smtp_port_for_connect(host_item * host, int port) | |
324 | { | |
325 | if (host->port != PORT_NONE) | |
326 | { | |
327 | HDEBUG(D_transport|D_acl|D_v) | |
328 | debug_printf_indent("Transport port=%d replaced by host-specific port=%d\n", port, | |
329 | host->port); | |
330 | port = host->port; | |
331 | } | |
332 | else host->port = port; /* Set the port actually used */ | |
333 | } | |
334 | ||
335 | ||
7eb6c37c JH |
336 | /************************************************* |
337 | * Connect to remote host * | |
338 | *************************************************/ | |
339 | ||
340 | /* Create a socket, and connect it to a remote host. IPv6 addresses are | |
341 | detected by checking for a colon in the address. AF_INET6 is defined even on | |
342 | non-IPv6 systems, to enable the code to be less messy. However, on such systems | |
343 | host->address will always be an IPv4 address. | |
344 | ||
7eb6c37c | 345 | Arguments: |
58c30e47 | 346 | host host item containing name and address and port |
7eb6c37c | 347 | host_af AF_INET or AF_INET6 |
7eb6c37c JH |
348 | interface outgoing interface address or NULL |
349 | timeout timeout value or 0 | |
350 | tb transport | |
351 | ||
352 | Returns: connected socket number, or -1 with errno set | |
353 | */ | |
354 | ||
355 | int | |
58c30e47 | 356 | smtp_connect(host_item *host, int host_af, uschar *interface, |
7eb6c37c JH |
357 | int timeout, transport_instance * tb) |
358 | { | |
58c30e47 | 359 | int port = host->port; |
f0989ec0 | 360 | #ifdef SUPPORT_SOCKS |
7eb6c37c JH |
361 | smtp_transport_options_block * ob = |
362 | (smtp_transport_options_block *)tb->options_block; | |
0539a19d | 363 | #endif |
7eb6c37c | 364 | |
055e2cb4 JH |
365 | callout_address = string_sprintf("[%s]:%d", host->address, port); |
366 | ||
7eb6c37c JH |
367 | HDEBUG(D_transport|D_acl|D_v) |
368 | { | |
369 | uschar * s = US" "; | |
370 | if (interface) s = string_sprintf(" from %s ", interface); | |
f0989ec0 | 371 | #ifdef SUPPORT_SOCKS |
7eb6c37c JH |
372 | if (ob->socks_proxy) s = string_sprintf("%svia proxy ", s); |
373 | #endif | |
e1d04f48 | 374 | debug_printf_indent("Connecting to %s %s%s... ", host->name, callout_address, s); |
7eb6c37c JH |
375 | } |
376 | ||
377 | /* Create and connect the socket */ | |
378 | ||
f0989ec0 | 379 | #ifdef SUPPORT_SOCKS |
7eb6c37c JH |
380 | if (ob->socks_proxy) |
381 | return socks_sock_connect(host, host_af, port, interface, tb, timeout); | |
382 | #endif | |
383 | ||
0ab63f3d | 384 | return smtp_sock_connect(host, host_af, port, interface, tb, timeout, NULL); |
7eb6c37c JH |
385 | } |
386 | ||
059ec3d9 PH |
387 | |
388 | /************************************************* | |
389 | * Flush outgoing command buffer * | |
390 | *************************************************/ | |
391 | ||
392 | /* This function is called only from smtp_write_command() below. It flushes | |
393 | the buffer of outgoing commands. There is more than one in the buffer only when | |
394 | pipelining. | |
395 | ||
396 | Argument: | |
397 | outblock the SMTP output block | |
925ac8e4 | 398 | mode further data expected, or plain |
059ec3d9 PH |
399 | |
400 | Returns: TRUE if OK, FALSE on error, with errno set | |
401 | */ | |
402 | ||
403 | static BOOL | |
4e910c01 | 404 | flush_buffer(smtp_outblock * outblock, int mode) |
059ec3d9 PH |
405 | { |
406 | int rc; | |
58fc5fb2 | 407 | int n = outblock->ptr - outblock->buffer; |
925ac8e4 | 408 | BOOL more = mode == SCMD_MORE; |
059ec3d9 | 409 | |
4e910c01 | 410 | HDEBUG(D_transport|D_acl) debug_printf_indent("cmd buf flush %d bytes%s\n", n, |
925ac8e4 | 411 | more ? " (more expected)" : ""); |
4e910c01 | 412 | |
059ec3d9 | 413 | #ifdef SUPPORT_TLS |
817d9f57 | 414 | if (tls_out.active == outblock->sock) |
925ac8e4 | 415 | rc = tls_write(FALSE, outblock->buffer, n, more); |
059ec3d9 PH |
416 | else |
417 | #endif | |
4e910c01 JH |
418 | rc = send(outblock->sock, outblock->buffer, n, |
419 | #ifdef MSG_MORE | |
925ac8e4 | 420 | more ? MSG_MORE : 0 |
4e910c01 JH |
421 | #else |
422 | 0 | |
423 | #endif | |
424 | ); | |
059ec3d9 | 425 | |
059ec3d9 PH |
426 | if (rc <= 0) |
427 | { | |
e1d04f48 | 428 | HDEBUG(D_transport|D_acl) debug_printf_indent("send failed: %s\n", strerror(errno)); |
059ec3d9 PH |
429 | return FALSE; |
430 | } | |
431 | ||
432 | outblock->ptr = outblock->buffer; | |
433 | outblock->cmd_count = 0; | |
434 | return TRUE; | |
435 | } | |
436 | ||
437 | ||
438 | ||
439 | /************************************************* | |
440 | * Write SMTP command * | |
441 | *************************************************/ | |
442 | ||
443 | /* The formatted command is left in big_buffer so that it can be reflected in | |
444 | any error message. | |
445 | ||
446 | Arguments: | |
447 | outblock contains buffer for pipelining, and socket | |
4e910c01 | 448 | mode buffer, write-with-more-likely, write |
059ec3d9 PH |
449 | format a format, starting with one of |
450 | of HELO, MAIL FROM, RCPT TO, DATA, ".", or QUIT. | |
6d5c916c | 451 | If NULL, flush pipeline buffer only. |
059ec3d9 PH |
452 | ... data for the format |
453 | ||
454 | Returns: 0 if command added to pipelining buffer, with nothing transmitted | |
455 | +n if n commands transmitted (may still have buffered the new one) | |
456 | -1 on error, with errno set | |
457 | */ | |
458 | ||
459 | int | |
4e910c01 | 460 | smtp_write_command(smtp_outblock * outblock, int mode, const char *format, ...) |
059ec3d9 PH |
461 | { |
462 | int count; | |
463 | int rc = 0; | |
464 | va_list ap; | |
465 | ||
6d5c916c | 466 | if (format) |
059ec3d9 | 467 | { |
6d5c916c JH |
468 | va_start(ap, format); |
469 | if (!string_vformat(big_buffer, big_buffer_size, CS format, ap)) | |
470 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong write_command in outgoing " | |
471 | "SMTP"); | |
472 | va_end(ap); | |
473 | count = Ustrlen(big_buffer); | |
474 | ||
475 | if (count > outblock->buffersize) | |
476 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong write_command in outgoing " | |
477 | "SMTP"); | |
478 | ||
479 | if (count > outblock->buffersize - (outblock->ptr - outblock->buffer)) | |
480 | { | |
481 | rc = outblock->cmd_count; /* flush resets */ | |
4e910c01 | 482 | if (!flush_buffer(outblock, SCMD_FLUSH)) return -1; |
6d5c916c | 483 | } |
059ec3d9 | 484 | |
6d5c916c JH |
485 | Ustrncpy(CS outblock->ptr, big_buffer, count); |
486 | outblock->ptr += count; | |
487 | outblock->cmd_count++; | |
488 | count -= 2; | |
489 | big_buffer[count] = 0; /* remove \r\n for error message */ | |
059ec3d9 | 490 | |
6d5c916c JH |
491 | /* We want to hide the actual data sent in AUTH transactions from reflections |
492 | and logs. While authenticating, a flag is set in the outblock to enable this. | |
493 | The AUTH command itself gets any data flattened. Other lines are flattened | |
494 | completely. */ | |
059ec3d9 | 495 | |
6d5c916c | 496 | if (outblock->authenticating) |
059ec3d9 | 497 | { |
6d5c916c JH |
498 | uschar *p = big_buffer; |
499 | if (Ustrncmp(big_buffer, "AUTH ", 5) == 0) | |
500 | { | |
501 | p += 5; | |
502 | while (isspace(*p)) p++; | |
503 | while (!isspace(*p)) p++; | |
504 | while (isspace(*p)) p++; | |
505 | } | |
506 | while (*p != 0) *p++ = '*'; | |
059ec3d9 | 507 | } |
059ec3d9 | 508 | |
e1d04f48 | 509 | HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> %s\n", big_buffer); |
6d5c916c | 510 | } |
059ec3d9 | 511 | |
4e910c01 | 512 | if (mode != SCMD_BUFFER) |
059ec3d9 PH |
513 | { |
514 | rc += outblock->cmd_count; /* flush resets */ | |
4e910c01 | 515 | if (!flush_buffer(outblock, mode)) return -1; |
059ec3d9 PH |
516 | } |
517 | ||
518 | return rc; | |
519 | } | |
520 | ||
521 | ||
522 | ||
523 | /************************************************* | |
524 | * Read one line of SMTP response * | |
525 | *************************************************/ | |
526 | ||
527 | /* This function reads one line of SMTP response from the server host. This may | |
528 | not be a complete response - it could be just part of a multiline response. We | |
529 | have to use a buffer for incoming packets, because when pipelining or using | |
530 | LMTP, there may well be more than one response in a single packet. This | |
531 | function is called only from the one that follows. | |
532 | ||
533 | Arguments: | |
534 | inblock the SMTP input block (contains holding buffer, socket, etc.) | |
535 | buffer where to put the line | |
536 | size space available for the line | |
537 | timeout the timeout to use when reading a packet | |
538 | ||
539 | Returns: length of a line that has been put in the buffer | |
540 | -1 otherwise, with errno set | |
541 | */ | |
542 | ||
543 | static int | |
544 | read_response_line(smtp_inblock *inblock, uschar *buffer, int size, int timeout) | |
545 | { | |
546 | uschar *p = buffer; | |
547 | uschar *ptr = inblock->ptr; | |
548 | uschar *ptrend = inblock->ptrend; | |
549 | int sock = inblock->sock; | |
550 | ||
551 | /* Loop for reading multiple packets or reading another packet after emptying | |
552 | a previously-read one. */ | |
553 | ||
554 | for (;;) | |
555 | { | |
556 | int rc; | |
557 | ||
558 | /* If there is data in the input buffer left over from last time, copy | |
559 | characters from it until the end of a line, at which point we can return, | |
560 | having removed any whitespace (which will include CR) at the end of the line. | |
561 | The rules for SMTP say that lines end in CRLF, but there are have been cases | |
562 | of hosts using just LF, and other MTAs are reported to handle this, so we | |
563 | just look for LF. If we run out of characters before the end of a line, | |
564 | carry on to read the next incoming packet. */ | |
565 | ||
566 | while (ptr < ptrend) | |
567 | { | |
568 | int c = *ptr++; | |
569 | if (c == '\n') | |
570 | { | |
571 | while (p > buffer && isspace(p[-1])) p--; | |
572 | *p = 0; | |
573 | inblock->ptr = ptr; | |
574 | return p - buffer; | |
575 | } | |
576 | *p++ = c; | |
577 | if (--size < 4) | |
578 | { | |
579 | *p = 0; /* Leave malformed line for error message */ | |
580 | errno = ERRNO_SMTPFORMAT; | |
581 | return -1; | |
582 | } | |
583 | } | |
584 | ||
585 | /* Need to read a new input packet. */ | |
586 | ||
de6273b4 JH |
587 | if((rc = ip_recv(sock, inblock->buffer, inblock->buffersize, timeout)) <= 0) |
588 | { | |
170f4904 JH |
589 | DEBUG(D_deliver|D_transport|D_acl) |
590 | debug_printf_indent(errno ? " SMTP(%s)<<\n" : " SMTP(closed)<<\n", | |
591 | strerror(errno)); | |
de6273b4 JH |
592 | break; |
593 | } | |
059ec3d9 PH |
594 | |
595 | /* Another block of data has been successfully read. Set up the pointers | |
596 | and let the loop continue. */ | |
597 | ||
598 | ptrend = inblock->ptrend = inblock->buffer + rc; | |
599 | ptr = inblock->buffer; | |
e1d04f48 | 600 | DEBUG(D_transport|D_acl) debug_printf_indent("read response data: size=%d\n", rc); |
059ec3d9 PH |
601 | } |
602 | ||
603 | /* Get here if there has been some kind of recv() error; errno is set, but we | |
604 | ensure that the result buffer is empty before returning. */ | |
605 | ||
606 | *buffer = 0; | |
607 | return -1; | |
608 | } | |
609 | ||
610 | ||
611 | ||
612 | ||
613 | ||
614 | /************************************************* | |
615 | * Read SMTP response * | |
616 | *************************************************/ | |
617 | ||
618 | /* This function reads an SMTP response with a timeout, and returns the | |
619 | response in the given buffer, as a string. A multiline response will contain | |
620 | newline characters between the lines. The function also analyzes the first | |
621 | digit of the reply code and returns FALSE if it is not acceptable. FALSE is | |
622 | also returned after a reading error. In this case buffer[0] will be zero, and | |
623 | the error code will be in errno. | |
624 | ||
625 | Arguments: | |
626 | inblock the SMTP input block (contains holding buffer, socket, etc.) | |
627 | buffer where to put the response | |
628 | size the size of the buffer | |
629 | okdigit the expected first digit of the response | |
2760b518 | 630 | timeout the timeout to use, in seconds |
059ec3d9 PH |
631 | |
632 | Returns: TRUE if a valid, non-error response was received; else FALSE | |
633 | */ | |
634 | ||
635 | BOOL | |
636 | smtp_read_response(smtp_inblock *inblock, uschar *buffer, int size, int okdigit, | |
637 | int timeout) | |
638 | { | |
639 | uschar *ptr = buffer; | |
640 | int count; | |
641 | ||
642 | errno = 0; /* Ensure errno starts out zero */ | |
643 | ||
4c04137d | 644 | /* This is a loop to read and concatenate the lines that make up a multi-line |
059ec3d9 PH |
645 | response. */ |
646 | ||
647 | for (;;) | |
648 | { | |
649 | if ((count = read_response_line(inblock, ptr, size, timeout)) < 0) | |
650 | return FALSE; | |
651 | ||
652 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 653 | debug_printf_indent(" %s %s\n", (ptr == buffer)? "SMTP<<" : " ", ptr); |
059ec3d9 PH |
654 | |
655 | /* Check the format of the response: it must start with three digits; if | |
656 | these are followed by a space or end of line, the response is complete. If | |
657 | they are followed by '-' this is a multi-line response and we must look for | |
658 | another line until the final line is reached. The only use made of multi-line | |
659 | responses is to pass them back as error messages. We therefore just | |
660 | concatenate them all within the buffer, which should be large enough to | |
661 | accept any reasonable number of lines. */ | |
662 | ||
663 | if (count < 3 || | |
664 | !isdigit(ptr[0]) || | |
665 | !isdigit(ptr[1]) || | |
666 | !isdigit(ptr[2]) || | |
667 | (ptr[3] != '-' && ptr[3] != ' ' && ptr[3] != 0)) | |
668 | { | |
669 | errno = ERRNO_SMTPFORMAT; /* format error */ | |
670 | return FALSE; | |
671 | } | |
672 | ||
673 | /* If the line we have just read is a terminal line, line, we are done. | |
674 | Otherwise more data has to be read. */ | |
675 | ||
676 | if (ptr[3] != '-') break; | |
677 | ||
678 | /* Move the reading pointer upwards in the buffer and insert \n between the | |
679 | components of a multiline response. Space is left for this by read_response_ | |
680 | line(). */ | |
681 | ||
682 | ptr += count; | |
683 | *ptr++ = '\n'; | |
684 | size -= count + 1; | |
685 | } | |
686 | ||
687 | /* Return a value that depends on the SMTP return code. On some systems a | |
688 | non-zero value of errno has been seen at this point, so ensure it is zero, | |
689 | because the caller of this function looks at errno when FALSE is returned, to | |
690 | distinguish between an unexpected return code and other errors such as | |
691 | timeouts, lost connections, etc. */ | |
692 | ||
693 | errno = 0; | |
694 | return buffer[0] == okdigit; | |
695 | } | |
696 | ||
697 | /* End of smtp_out.c */ | |
7eb6c37c JH |
698 | /* vi: aw ai sw=2 |
699 | */ |