Commit | Line | Data |
---|---|---|
059ec3d9 PH |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
f9ba5e22 | 5 | /* Copyright (c) University of Cambridge 1995 - 2018 */ |
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 | 47 | { |
8768d548 | 48 | if (f.expand_string_forcedfail) return TRUE; |
059ec3d9 PH |
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 | ||
f3ebb786 JH |
55 | if (is_tainted(expint)) |
56 | { | |
57 | log_write(0, LOG_MAIN|LOG_PANIC, | |
58 | "attempt to use tainted value '%s' from '%s' for interface", | |
59 | expint, istring); | |
60 | addr->transport_return = PANIC; | |
61 | addr->message = string_sprintf("failed to expand \"interface\" " | |
62 | "option for %s: configuration error", msg); | |
63 | return FALSE; | |
64 | } | |
65 | ||
137ae145 JH |
66 | Uskip_whitespace(&expint); |
67 | if (!*expint) return TRUE; | |
059ec3d9 PH |
68 | |
69 | while ((iface = string_nextinlist(&expint, &sep, big_buffer, | |
fb05276a | 70 | big_buffer_size))) |
059ec3d9 PH |
71 | { |
72 | if (string_is_ip_address(iface, NULL) == 0) | |
73 | { | |
74 | addr->transport_return = PANIC; | |
75 | addr->message = string_sprintf("\"%s\" is not a valid IP " | |
76 | "address for the \"interface\" option for %s", | |
77 | iface, msg); | |
78 | return FALSE; | |
79 | } | |
80 | ||
81 | if (((Ustrchr(iface, ':') == NULL)? AF_INET:AF_INET6) == host_af) | |
82 | break; | |
83 | } | |
84 | ||
fb05276a | 85 | if (iface) *interface = string_copy(iface); |
059ec3d9 PH |
86 | return TRUE; |
87 | } | |
88 | ||
89 | ||
90 | ||
91 | /************************************************* | |
92 | * Find an outgoing port * | |
93 | *************************************************/ | |
94 | ||
95 | /* This function is called from the smtp transport and also from the callout | |
96 | code in verify.c. Its job is to find a port number. Note that getservbyname() | |
97 | produces the number in network byte order. | |
98 | ||
99 | Arguments: | |
100 | rstring raw (unexpanded) string representation of the port | |
101 | addr the mail address being handled (for setting errors) | |
102 | port stick the port in here | |
103 | msg for adding to error message | |
104 | ||
105 | Returns: TRUE on success, FALSE on failure, with error message set | |
106 | in addr, and transport_return set to PANIC | |
107 | */ | |
108 | ||
109 | BOOL | |
110 | smtp_get_port(uschar *rstring, address_item *addr, int *port, uschar *msg) | |
111 | { | |
112 | uschar *pstring = expand_string(rstring); | |
113 | ||
00580051 | 114 | if (!pstring) |
059ec3d9 PH |
115 | { |
116 | addr->transport_return = PANIC; | |
117 | addr->message = string_sprintf("failed to expand \"%s\" (\"port\" option) " | |
118 | "for %s: %s", rstring, msg, expand_string_message); | |
119 | return FALSE; | |
120 | } | |
121 | ||
122 | if (isdigit(*pstring)) | |
123 | { | |
124 | uschar *end; | |
125 | *port = Ustrtol(pstring, &end, 0); | |
126 | if (end != pstring + Ustrlen(pstring)) | |
127 | { | |
128 | addr->transport_return = PANIC; | |
129 | addr->message = string_sprintf("invalid port number for %s: %s", msg, | |
130 | pstring); | |
131 | return FALSE; | |
132 | } | |
133 | } | |
134 | ||
135 | else | |
136 | { | |
137 | struct servent *smtp_service = getservbyname(CS pstring, "tcp"); | |
00580051 | 138 | if (!smtp_service) |
059ec3d9 PH |
139 | { |
140 | addr->transport_return = PANIC; | |
141 | addr->message = string_sprintf("TCP port \"%s\" is not defined for %s", | |
142 | pstring, msg); | |
143 | return FALSE; | |
144 | } | |
145 | *port = ntohs(smtp_service->s_port); | |
146 | } | |
147 | ||
148 | return TRUE; | |
149 | } | |
150 | ||
151 | ||
152 | ||
153 | ||
1ccd5f67 JH |
154 | #ifdef TCP_FASTOPEN |
155 | static void | |
156 | tfo_out_check(int sock) | |
157 | { | |
53c7b3a7 | 158 | # ifdef __FreeBSD__ |
1ccd5f67 | 159 | struct tcp_info tinfo; |
73a10da9 JH |
160 | int val; |
161 | socklen_t len = sizeof(val); | |
162 | ||
73a10da9 JH |
163 | /* The observability as of 12.1 is not useful as a client, only telling us that |
164 | a TFO option was used on SYN. It could have been a TFO-R, or ignored by the | |
165 | server. */ | |
166 | ||
167 | /* | |
168 | if (tcp_out_fastopen == TFO_ATTEMPTED_NODATA || tcp_out_fastopen == TFO_ATTEMPTED_DATA) | |
169 | if (getsockopt(sock, IPPROTO_TCP, TCP_FASTOPEN, &val, &len) == 0 && val != 0) {} | |
170 | */ | |
171 | switch (tcp_out_fastopen) | |
172 | { | |
173 | case TFO_ATTEMPTED_NODATA: tcp_out_fastopen = TFO_USED_NODATA; break; | |
174 | case TFO_ATTEMPTED_DATA: tcp_out_fastopen = TFO_USED_DATA; break; | |
175 | default: break; /* compiler quietening */ | |
176 | } | |
177 | ||
178 | # else /* Linux & Apple */ | |
179 | # if defined(TCP_INFO) && defined(EXIM_HAVE_TCPI_UNACKED) | |
53c7b3a7 JH |
180 | struct tcp_info tinfo; |
181 | socklen_t len = sizeof(tinfo); | |
1ccd5f67 | 182 | |
ee8b8090 JH |
183 | switch (tcp_out_fastopen) |
184 | { | |
185 | /* This is a somewhat dubious detection method; totally undocumented so likely | |
186 | to fail in future kernels. There seems to be no documented way. What we really | |
187 | want to know is if the server sent smtp-banner data before our ACK of his SYN,ACK | |
188 | hit him. What this (possibly?) detects is whether we sent a TFO cookie with our | |
189 | SYN, as distinct from a TFO request. This gets a false-positive when the server | |
190 | key is rotated; we send the old one (which this test sees) but the server returns | |
191 | the new one and does not send its SMTP banner before we ACK his SYN,ACK. | |
192 | To force that rotation case: | |
193 | '# echo -n "00000000-00000000-00000000-0000000" >/proc/sys/net/ipv4/tcp_fastopen_key' | |
194 | The kernel seems to be counting unack'd packets. */ | |
195 | ||
196 | case TFO_ATTEMPTED_NODATA: | |
197 | if ( getsockopt(sock, IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0 | |
198 | && tinfo.tcpi_state == TCP_SYN_SENT | |
199 | && tinfo.tcpi_unacked > 1 | |
200 | ) | |
201 | { | |
202 | DEBUG(D_transport|D_v) | |
203 | debug_printf("TCP_FASTOPEN tcpi_unacked %d\n", tinfo.tcpi_unacked); | |
204 | tcp_out_fastopen = TFO_USED_NODATA; | |
205 | } | |
206 | break; | |
1ccd5f67 | 207 | |
ee8b8090 JH |
208 | /* When called after waiting for received data we should be able |
209 | to tell if data we sent was accepted. */ | |
1ccd5f67 | 210 | |
ee8b8090 JH |
211 | case TFO_ATTEMPTED_DATA: |
212 | if ( getsockopt(sock, IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0 | |
213 | && tinfo.tcpi_state == TCP_ESTABLISHED | |
214 | ) | |
215 | if (tinfo.tcpi_options & TCPI_OPT_SYN_DATA) | |
216 | { | |
217 | DEBUG(D_transport|D_v) debug_printf("TFO: data was acked\n"); | |
218 | tcp_out_fastopen = TFO_USED_DATA; | |
219 | } | |
220 | else | |
1ccd5f67 JH |
221 | { |
222 | DEBUG(D_transport|D_v) debug_printf("TFO: had to retransmit\n"); | |
06e272a3 | 223 | tcp_out_fastopen = TFO_NOT_USED; |
1ccd5f67 | 224 | } |
ee8b8090 | 225 | break; |
56dbf856 JH |
226 | |
227 | default: break; /* compiler quietening */ | |
ee8b8090 | 228 | } |
73a10da9 JH |
229 | # endif |
230 | # endif /* Linux & Apple */ | |
1ccd5f67 JH |
231 | } |
232 | #endif | |
233 | ||
234 | ||
0ab63f3d | 235 | /* Arguments as for smtp_connect(), plus |
b536a578 JH |
236 | early_data if non-NULL, idenmpotent data to be sent - |
237 | preferably in the TCP SYN segment | |
0ab63f3d JH |
238 | |
239 | Returns: connected socket number, or -1 with errno set | |
240 | */ | |
241 | ||
059ec3d9 | 242 | int |
7eb6c37c | 243 | smtp_sock_connect(host_item * host, int host_af, int port, uschar * interface, |
0ab63f3d | 244 | transport_instance * tb, int timeout, const blob * early_data) |
059ec3d9 | 245 | { |
7eb6c37c JH |
246 | smtp_transport_options_block * ob = |
247 | (smtp_transport_options_block *)tb->options_block; | |
248 | const uschar * dscp = ob->dscp; | |
9e4f5962 PP |
249 | int dscp_value; |
250 | int dscp_level; | |
251 | int dscp_option; | |
059ec3d9 | 252 | int sock; |
7eb6c37c | 253 | int save_errno = 0; |
10ac8d7f | 254 | const blob * fastopen_blob = NULL; |
1ccd5f67 | 255 | |
059ec3d9 | 256 | |
0cbf2b82 | 257 | #ifndef DISABLE_EVENT |
7eb6c37c JH |
258 | deliver_host_address = host->address; |
259 | deliver_host_port = port; | |
260 | if (event_raise(tb->event_action, US"tcp:connect", NULL)) return -1; | |
a7538db1 JH |
261 | #endif |
262 | ||
059ec3d9 PH |
263 | if ((sock = ip_socket(SOCK_STREAM, host_af)) < 0) return -1; |
264 | ||
265 | /* Set TCP_NODELAY; Exim does its own buffering. */ | |
266 | ||
d4ff61d1 JH |
267 | if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, US &on, sizeof(on))) |
268 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 269 | debug_printf_indent("failed to set NODELAY: %s ", strerror(errno)); |
059ec3d9 | 270 | |
9e4f5962 PP |
271 | /* Set DSCP value, if we can. For now, if we fail to set the value, we don't |
272 | bomb out, just log it and continue in default traffic class. */ | |
273 | ||
274 | if (dscp && dscp_lookup(dscp, host_af, &dscp_level, &dscp_option, &dscp_value)) | |
275 | { | |
276 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 277 | debug_printf_indent("DSCP \"%s\"=%x ", dscp, dscp_value); |
9e4f5962 PP |
278 | if (setsockopt(sock, dscp_level, dscp_option, &dscp_value, sizeof(dscp_value)) < 0) |
279 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 280 | debug_printf_indent("failed to set DSCP: %s ", strerror(errno)); |
9e4f5962 PP |
281 | /* If the kernel supports IPv4 and IPv6 on an IPv6 socket, we need to set the |
282 | option for both; ignore failures here */ | |
283 | if (host_af == AF_INET6 && | |
284 | dscp_lookup(dscp, AF_INET, &dscp_level, &dscp_option, &dscp_value)) | |
9e4f5962 | 285 | (void) setsockopt(sock, dscp_level, dscp_option, &dscp_value, sizeof(dscp_value)); |
9e4f5962 PP |
286 | } |
287 | ||
059ec3d9 PH |
288 | /* Bind to a specific interface if requested. Caller must ensure the interface |
289 | is the same type (IPv4 or IPv6) as the outgoing address. */ | |
290 | ||
7eb6c37c | 291 | if (interface && ip_bind(sock, host_af, interface, 0) < 0) |
059ec3d9 PH |
292 | { |
293 | save_errno = errno; | |
294 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 295 | debug_printf_indent("unable to bind outgoing SMTP call to %s: %s", interface, |
059ec3d9 PH |
296 | strerror(errno)); |
297 | } | |
298 | ||
299 | /* Connect to the remote host, and add keepalive to the socket before returning | |
0ab63f3d | 300 | it, if requested. If the build supports TFO, request it - and if the caller |
ee8b8090 JH |
301 | requested some early-data then include that in the TFO request. If there is |
302 | early-data but no TFO support, send it after connecting. */ | |
059ec3d9 | 303 | |
0ab63f3d JH |
304 | else |
305 | { | |
0ab63f3d | 306 | #ifdef TCP_FASTOPEN |
3fb3231c | 307 | if (verify_check_given_host(CUSS &ob->hosts_try_fastopen, host) == OK) |
10ac8d7f | 308 | fastopen_blob = early_data ? early_data : &tcp_fastopen_nodata; |
0ab63f3d JH |
309 | #endif |
310 | ||
10ac8d7f | 311 | if (ip_connect(sock, host_af, host->address, port, timeout, fastopen_blob) < 0) |
0ab63f3d | 312 | save_errno = errno; |
10ac8d7f | 313 | else if (early_data && !fastopen_blob && early_data->data && early_data->len) |
ee8b8090 JH |
314 | { |
315 | HDEBUG(D_transport|D_acl|D_v) | |
316 | debug_printf("sending %ld nonTFO early-data\n", (long)early_data->len); | |
317 | ||
318 | #ifdef TCP_QUICKACK | |
319 | (void) setsockopt(sock, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off)); | |
320 | #endif | |
0ab63f3d JH |
321 | if (send(sock, early_data->data, early_data->len, 0) < 0) |
322 | save_errno = errno; | |
ee8b8090 | 323 | } |
0ab63f3d | 324 | } |
059ec3d9 PH |
325 | |
326 | /* Either bind() or connect() failed */ | |
327 | ||
328 | if (save_errno != 0) | |
329 | { | |
8e669ac1 | 330 | HDEBUG(D_transport|D_acl|D_v) |
4deaf07d | 331 | { |
adb21834 | 332 | debug_printf_indent(" failed: %s", CUstrerror(save_errno)); |
8e669ac1 | 333 | if (save_errno == ETIMEDOUT) |
4deaf07d | 334 | debug_printf(" (timeout=%s)", readconf_printtime(timeout)); |
8e669ac1 PH |
335 | debug_printf("\n"); |
336 | } | |
f1e894f3 | 337 | (void)close(sock); |
059ec3d9 PH |
338 | errno = save_errno; |
339 | return -1; | |
340 | } | |
341 | ||
ee8b8090 | 342 | /* Both bind() and connect() succeeded, and any early-data */ |
059ec3d9 PH |
343 | |
344 | else | |
345 | { | |
41c7c167 PH |
346 | union sockaddr_46 interface_sock; |
347 | EXIM_SOCKLEN_T size = sizeof(interface_sock); | |
ee8b8090 | 348 | |
adb21834 | 349 | HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" connected\n"); |
41c7c167 PH |
350 | if (getsockname(sock, (struct sockaddr *)(&interface_sock), &size) == 0) |
351 | sending_ip_address = host_ntoa(-1, &interface_sock, NULL, &sending_port); | |
352 | else | |
353 | { | |
354 | log_write(0, LOG_MAIN | ((errno == ECONNRESET)? 0 : LOG_PANIC), | |
355 | "getsockname() failed: %s", strerror(errno)); | |
356 | close(sock); | |
357 | return -1; | |
358 | } | |
ee8b8090 | 359 | |
7eb6c37c | 360 | if (ob->keepalive) ip_keepalive(sock, host->address, TRUE); |
1ccd5f67 | 361 | #ifdef TCP_FASTOPEN |
ee8b8090 | 362 | tfo_out_check(sock); |
1ccd5f67 | 363 | #endif |
059ec3d9 PH |
364 | return sock; |
365 | } | |
366 | } | |
367 | ||
58c30e47 JH |
368 | |
369 | ||
370 | ||
371 | ||
372 | void | |
373 | smtp_port_for_connect(host_item * host, int port) | |
374 | { | |
375 | if (host->port != PORT_NONE) | |
376 | { | |
377 | HDEBUG(D_transport|D_acl|D_v) | |
378 | debug_printf_indent("Transport port=%d replaced by host-specific port=%d\n", port, | |
379 | host->port); | |
380 | port = host->port; | |
381 | } | |
382 | else host->port = port; /* Set the port actually used */ | |
383 | } | |
384 | ||
385 | ||
7eb6c37c JH |
386 | /************************************************* |
387 | * Connect to remote host * | |
388 | *************************************************/ | |
389 | ||
390 | /* Create a socket, and connect it to a remote host. IPv6 addresses are | |
391 | detected by checking for a colon in the address. AF_INET6 is defined even on | |
392 | non-IPv6 systems, to enable the code to be less messy. However, on such systems | |
393 | host->address will always be an IPv4 address. | |
394 | ||
7eb6c37c | 395 | Arguments: |
ee8b8090 JH |
396 | sc details for making connection: host, af, interface, transport |
397 | early_data if non-NULL, data to be sent - preferably in the TCP SYN segment | |
7eb6c37c JH |
398 | |
399 | Returns: connected socket number, or -1 with errno set | |
400 | */ | |
401 | ||
402 | int | |
ee8b8090 | 403 | smtp_connect(smtp_connect_args * sc, const blob * early_data) |
7eb6c37c | 404 | { |
ee8b8090 JH |
405 | int port = sc->host->port; |
406 | smtp_transport_options_block * ob = sc->ob; | |
7eb6c37c | 407 | |
ee8b8090 | 408 | callout_address = string_sprintf("[%s]:%d", sc->host->address, port); |
055e2cb4 | 409 | |
7eb6c37c JH |
410 | HDEBUG(D_transport|D_acl|D_v) |
411 | { | |
412 | uschar * s = US" "; | |
ee8b8090 | 413 | if (sc->interface) s = string_sprintf(" from %s ", sc->interface); |
f0989ec0 | 414 | #ifdef SUPPORT_SOCKS |
7eb6c37c JH |
415 | if (ob->socks_proxy) s = string_sprintf("%svia proxy ", s); |
416 | #endif | |
ee8b8090 | 417 | debug_printf_indent("Connecting to %s %s%s... ", sc->host->name, callout_address, s); |
7eb6c37c JH |
418 | } |
419 | ||
420 | /* Create and connect the socket */ | |
421 | ||
f0989ec0 | 422 | #ifdef SUPPORT_SOCKS |
7eb6c37c | 423 | if (ob->socks_proxy) |
ee8b8090 JH |
424 | { |
425 | int sock = socks_sock_connect(sc->host, sc->host_af, port, sc->interface, | |
426 | sc->tblock, ob->connect_timeout); | |
427 | ||
428 | if (sock >= 0) | |
429 | { | |
430 | if (early_data && early_data->data && early_data->len) | |
431 | if (send(sock, early_data->data, early_data->len, 0) < 0) | |
432 | { | |
433 | int save_errno = errno; | |
434 | HDEBUG(D_transport|D_acl|D_v) | |
435 | { | |
436 | debug_printf_indent("failed: %s", CUstrerror(save_errno)); | |
437 | if (save_errno == ETIMEDOUT) | |
438 | debug_printf(" (timeout=%s)", readconf_printtime(ob->connect_timeout)); | |
439 | debug_printf("\n"); | |
440 | } | |
441 | (void)close(sock); | |
442 | sock = -1; | |
443 | errno = save_errno; | |
444 | } | |
445 | } | |
446 | return sock; | |
447 | } | |
7eb6c37c JH |
448 | #endif |
449 | ||
ee8b8090 JH |
450 | return smtp_sock_connect(sc->host, sc->host_af, port, sc->interface, |
451 | sc->tblock, ob->connect_timeout, early_data); | |
7eb6c37c JH |
452 | } |
453 | ||
059ec3d9 PH |
454 | |
455 | /************************************************* | |
456 | * Flush outgoing command buffer * | |
457 | *************************************************/ | |
458 | ||
459 | /* This function is called only from smtp_write_command() below. It flushes | |
460 | the buffer of outgoing commands. There is more than one in the buffer only when | |
461 | pipelining. | |
462 | ||
463 | Argument: | |
464 | outblock the SMTP output block | |
925ac8e4 | 465 | mode further data expected, or plain |
059ec3d9 PH |
466 | |
467 | Returns: TRUE if OK, FALSE on error, with errno set | |
468 | */ | |
469 | ||
470 | static BOOL | |
4e910c01 | 471 | flush_buffer(smtp_outblock * outblock, int mode) |
059ec3d9 PH |
472 | { |
473 | int rc; | |
58fc5fb2 | 474 | int n = outblock->ptr - outblock->buffer; |
925ac8e4 | 475 | BOOL more = mode == SCMD_MORE; |
059ec3d9 | 476 | |
4e910c01 | 477 | HDEBUG(D_transport|D_acl) debug_printf_indent("cmd buf flush %d bytes%s\n", n, |
925ac8e4 | 478 | more ? " (more expected)" : ""); |
4e910c01 | 479 | |
01603eec | 480 | #ifndef DISABLE_TLS |
74f1a423 JH |
481 | if (outblock->cctx->tls_ctx) |
482 | rc = tls_write(outblock->cctx->tls_ctx, outblock->buffer, n, more); | |
059ec3d9 PH |
483 | else |
484 | #endif | |
ee8b8090 JH |
485 | |
486 | { | |
487 | if (outblock->conn_args) | |
488 | { | |
489 | blob early_data = { .data = outblock->buffer, .len = n }; | |
490 | ||
491 | /* We ignore the more-flag if we're doing a connect with early-data, which | |
492 | means we won't get BDAT+data. A pity, but wise due to the idempotency | |
493 | requirement: TFO with data can, in rare cases, replay the data to the | |
494 | receiver. */ | |
495 | ||
496 | if ( (outblock->cctx->sock = smtp_connect(outblock->conn_args, &early_data)) | |
497 | < 0) | |
498 | return FALSE; | |
499 | outblock->conn_args = NULL; | |
500 | rc = n; | |
501 | } | |
502 | else | |
ff966302 | 503 | { |
ee8b8090 | 504 | rc = send(outblock->cctx->sock, outblock->buffer, n, |
4e910c01 | 505 | #ifdef MSG_MORE |
ee8b8090 | 506 | more ? MSG_MORE : 0 |
4e910c01 | 507 | #else |
ee8b8090 | 508 | 0 |
4e910c01 | 509 | #endif |
ee8b8090 | 510 | ); |
ff966302 | 511 | } |
ee8b8090 | 512 | } |
059ec3d9 | 513 | |
059ec3d9 PH |
514 | if (rc <= 0) |
515 | { | |
e1d04f48 | 516 | HDEBUG(D_transport|D_acl) debug_printf_indent("send failed: %s\n", strerror(errno)); |
059ec3d9 PH |
517 | return FALSE; |
518 | } | |
519 | ||
520 | outblock->ptr = outblock->buffer; | |
521 | outblock->cmd_count = 0; | |
522 | return TRUE; | |
523 | } | |
524 | ||
525 | ||
526 | ||
527 | /************************************************* | |
528 | * Write SMTP command * | |
529 | *************************************************/ | |
530 | ||
531 | /* The formatted command is left in big_buffer so that it can be reflected in | |
532 | any error message. | |
533 | ||
534 | Arguments: | |
251b9eb4 | 535 | sx SMTP connection, contains buffer for pipelining, and socket |
4e910c01 | 536 | mode buffer, write-with-more-likely, write |
059ec3d9 PH |
537 | format a format, starting with one of |
538 | of HELO, MAIL FROM, RCPT TO, DATA, ".", or QUIT. | |
6d5c916c | 539 | If NULL, flush pipeline buffer only. |
059ec3d9 PH |
540 | ... data for the format |
541 | ||
542 | Returns: 0 if command added to pipelining buffer, with nothing transmitted | |
543 | +n if n commands transmitted (may still have buffered the new one) | |
544 | -1 on error, with errno set | |
545 | */ | |
546 | ||
547 | int | |
251b9eb4 | 548 | smtp_write_command(void * sx, int mode, const char *format, ...) |
059ec3d9 | 549 | { |
251b9eb4 | 550 | smtp_outblock * outblock = &((smtp_context *)sx)->outblock; |
059ec3d9 | 551 | int rc = 0; |
059ec3d9 | 552 | |
6d5c916c | 553 | if (format) |
059ec3d9 | 554 | { |
d12746bc JH |
555 | gstring gs = { .size = big_buffer_size, .ptr = 0, .s = big_buffer }; |
556 | va_list ap; | |
557 | ||
f3ebb786 JH |
558 | /* Use taint-unchecked routines for writing into big_buffer, trusting that |
559 | we'll never expand the results. Actually, the error-message use - leaving | |
560 | the results in big_buffer for potential later use - is uncomfortably distant. | |
561 | XXX Would be better to assume all smtp commands are short, use normal pool | |
562 | alloc rather than big_buffer, and another global for the data-for-error. */ | |
563 | ||
6d5c916c | 564 | va_start(ap, format); |
f3ebb786 | 565 | if (!string_vformat(&gs, SVFMT_TAINT_NOCHK, CS format, ap)) |
6d5c916c JH |
566 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong write_command in outgoing " |
567 | "SMTP"); | |
568 | va_end(ap); | |
d12746bc | 569 | string_from_gstring(&gs); |
6d5c916c | 570 | |
d12746bc | 571 | if (gs.ptr > outblock->buffersize) |
6d5c916c JH |
572 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong write_command in outgoing " |
573 | "SMTP"); | |
574 | ||
d12746bc | 575 | if (gs.ptr > outblock->buffersize - (outblock->ptr - outblock->buffer)) |
6d5c916c JH |
576 | { |
577 | rc = outblock->cmd_count; /* flush resets */ | |
4e910c01 | 578 | if (!flush_buffer(outblock, SCMD_FLUSH)) return -1; |
6d5c916c | 579 | } |
059ec3d9 | 580 | |
f3ebb786 | 581 | Ustrncpy(outblock->ptr, gs.s, gs.ptr); |
d12746bc | 582 | outblock->ptr += gs.ptr; |
6d5c916c | 583 | outblock->cmd_count++; |
d12746bc | 584 | gs.ptr -= 2; string_from_gstring(&gs); /* remove \r\n for error message */ |
059ec3d9 | 585 | |
6d5c916c JH |
586 | /* We want to hide the actual data sent in AUTH transactions from reflections |
587 | and logs. While authenticating, a flag is set in the outblock to enable this. | |
588 | The AUTH command itself gets any data flattened. Other lines are flattened | |
589 | completely. */ | |
059ec3d9 | 590 | |
6d5c916c | 591 | if (outblock->authenticating) |
059ec3d9 | 592 | { |
6d5c916c JH |
593 | uschar *p = big_buffer; |
594 | if (Ustrncmp(big_buffer, "AUTH ", 5) == 0) | |
595 | { | |
596 | p += 5; | |
597 | while (isspace(*p)) p++; | |
598 | while (!isspace(*p)) p++; | |
599 | while (isspace(*p)) p++; | |
600 | } | |
601 | while (*p != 0) *p++ = '*'; | |
059ec3d9 | 602 | } |
059ec3d9 | 603 | |
e1d04f48 | 604 | HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> %s\n", big_buffer); |
6d5c916c | 605 | } |
059ec3d9 | 606 | |
4e910c01 | 607 | if (mode != SCMD_BUFFER) |
059ec3d9 PH |
608 | { |
609 | rc += outblock->cmd_count; /* flush resets */ | |
4e910c01 | 610 | if (!flush_buffer(outblock, mode)) return -1; |
059ec3d9 PH |
611 | } |
612 | ||
613 | return rc; | |
614 | } | |
615 | ||
616 | ||
617 | ||
618 | /************************************************* | |
619 | * Read one line of SMTP response * | |
620 | *************************************************/ | |
621 | ||
622 | /* This function reads one line of SMTP response from the server host. This may | |
623 | not be a complete response - it could be just part of a multiline response. We | |
624 | have to use a buffer for incoming packets, because when pipelining or using | |
625 | LMTP, there may well be more than one response in a single packet. This | |
626 | function is called only from the one that follows. | |
627 | ||
628 | Arguments: | |
629 | inblock the SMTP input block (contains holding buffer, socket, etc.) | |
630 | buffer where to put the line | |
631 | size space available for the line | |
0a5441fc | 632 | timelimit deadline for reading the lime, seconds past epoch |
059ec3d9 PH |
633 | |
634 | Returns: length of a line that has been put in the buffer | |
635 | -1 otherwise, with errno set | |
636 | */ | |
637 | ||
638 | static int | |
0a5441fc | 639 | read_response_line(smtp_inblock *inblock, uschar *buffer, int size, time_t timelimit) |
059ec3d9 PH |
640 | { |
641 | uschar *p = buffer; | |
642 | uschar *ptr = inblock->ptr; | |
643 | uschar *ptrend = inblock->ptrend; | |
74f1a423 | 644 | client_conn_ctx * cctx = inblock->cctx; |
059ec3d9 PH |
645 | |
646 | /* Loop for reading multiple packets or reading another packet after emptying | |
647 | a previously-read one. */ | |
648 | ||
649 | for (;;) | |
650 | { | |
651 | int rc; | |
652 | ||
653 | /* If there is data in the input buffer left over from last time, copy | |
654 | characters from it until the end of a line, at which point we can return, | |
655 | having removed any whitespace (which will include CR) at the end of the line. | |
656 | The rules for SMTP say that lines end in CRLF, but there are have been cases | |
657 | of hosts using just LF, and other MTAs are reported to handle this, so we | |
658 | just look for LF. If we run out of characters before the end of a line, | |
659 | carry on to read the next incoming packet. */ | |
660 | ||
661 | while (ptr < ptrend) | |
662 | { | |
663 | int c = *ptr++; | |
664 | if (c == '\n') | |
665 | { | |
666 | while (p > buffer && isspace(p[-1])) p--; | |
667 | *p = 0; | |
668 | inblock->ptr = ptr; | |
669 | return p - buffer; | |
670 | } | |
671 | *p++ = c; | |
672 | if (--size < 4) | |
673 | { | |
674 | *p = 0; /* Leave malformed line for error message */ | |
675 | errno = ERRNO_SMTPFORMAT; | |
676 | return -1; | |
677 | } | |
678 | } | |
679 | ||
680 | /* Need to read a new input packet. */ | |
681 | ||
0a5441fc | 682 | if((rc = ip_recv(cctx, inblock->buffer, inblock->buffersize, timelimit)) <= 0) |
de6273b4 | 683 | { |
eebcfa1c | 684 | DEBUG(D_deliver|D_transport|D_acl|D_v) |
170f4904 JH |
685 | debug_printf_indent(errno ? " SMTP(%s)<<\n" : " SMTP(closed)<<\n", |
686 | strerror(errno)); | |
de6273b4 JH |
687 | break; |
688 | } | |
059ec3d9 PH |
689 | |
690 | /* Another block of data has been successfully read. Set up the pointers | |
691 | and let the loop continue. */ | |
692 | ||
693 | ptrend = inblock->ptrend = inblock->buffer + rc; | |
694 | ptr = inblock->buffer; | |
e1d04f48 | 695 | DEBUG(D_transport|D_acl) debug_printf_indent("read response data: size=%d\n", rc); |
059ec3d9 PH |
696 | } |
697 | ||
698 | /* Get here if there has been some kind of recv() error; errno is set, but we | |
699 | ensure that the result buffer is empty before returning. */ | |
700 | ||
701 | *buffer = 0; | |
702 | return -1; | |
703 | } | |
704 | ||
705 | ||
706 | ||
707 | ||
708 | ||
709 | /************************************************* | |
710 | * Read SMTP response * | |
711 | *************************************************/ | |
712 | ||
713 | /* This function reads an SMTP response with a timeout, and returns the | |
714 | response in the given buffer, as a string. A multiline response will contain | |
715 | newline characters between the lines. The function also analyzes the first | |
716 | digit of the reply code and returns FALSE if it is not acceptable. FALSE is | |
717 | also returned after a reading error. In this case buffer[0] will be zero, and | |
718 | the error code will be in errno. | |
719 | ||
720 | Arguments: | |
251b9eb4 JH |
721 | sx the SMTP connection (contains input block with holding buffer, |
722 | socket, etc.) | |
059ec3d9 PH |
723 | buffer where to put the response |
724 | size the size of the buffer | |
725 | okdigit the expected first digit of the response | |
2760b518 | 726 | timeout the timeout to use, in seconds |
059ec3d9 PH |
727 | |
728 | Returns: TRUE if a valid, non-error response was received; else FALSE | |
729 | */ | |
ee8b8090 | 730 | /*XXX could move to smtp transport; no other users */ |
059ec3d9 PH |
731 | |
732 | BOOL | |
fc243e94 | 733 | smtp_read_response(void * sx0, uschar * buffer, int size, int okdigit, |
059ec3d9 PH |
734 | int timeout) |
735 | { | |
ee8b8090 | 736 | smtp_context * sx = sx0; |
fc243e94 | 737 | uschar * ptr = buffer; |
dca6d121 | 738 | int count = 0; |
0a5441fc | 739 | time_t timelimit = time(NULL) + timeout; |
059ec3d9 PH |
740 | |
741 | errno = 0; /* Ensure errno starts out zero */ | |
742 | ||
81344b40 | 743 | #ifndef DISABLE_PIPE_CONNECT |
ee8b8090 | 744 | if (sx->pending_BANNER || sx->pending_EHLO) |
dca6d121 JH |
745 | { |
746 | int rc; | |
fc243e94 | 747 | if ((rc = smtp_reap_early_pipe(sx, &count)) != OK) |
ee8b8090 JH |
748 | { |
749 | DEBUG(D_transport) debug_printf("failed reaping pipelined cmd responsess\n"); | |
fc243e94 JH |
750 | buffer[0] = '\0'; |
751 | if (rc == DEFER) errno = ERRNO_TLSFAILURE; | |
ee8b8090 JH |
752 | return FALSE; |
753 | } | |
dca6d121 | 754 | } |
ee8b8090 JH |
755 | #endif |
756 | ||
4c04137d | 757 | /* This is a loop to read and concatenate the lines that make up a multi-line |
059ec3d9 PH |
758 | response. */ |
759 | ||
760 | for (;;) | |
761 | { | |
0a5441fc | 762 | if ((count = read_response_line(&sx->inblock, ptr, size, timelimit)) < 0) |
059ec3d9 PH |
763 | return FALSE; |
764 | ||
765 | HDEBUG(D_transport|D_acl|D_v) | |
ee8b8090 | 766 | debug_printf_indent(" %s %s\n", ptr == buffer ? "SMTP<<" : " ", ptr); |
059ec3d9 PH |
767 | |
768 | /* Check the format of the response: it must start with three digits; if | |
769 | these are followed by a space or end of line, the response is complete. If | |
770 | they are followed by '-' this is a multi-line response and we must look for | |
771 | another line until the final line is reached. The only use made of multi-line | |
772 | responses is to pass them back as error messages. We therefore just | |
773 | concatenate them all within the buffer, which should be large enough to | |
774 | accept any reasonable number of lines. */ | |
775 | ||
776 | if (count < 3 || | |
777 | !isdigit(ptr[0]) || | |
778 | !isdigit(ptr[1]) || | |
779 | !isdigit(ptr[2]) || | |
780 | (ptr[3] != '-' && ptr[3] != ' ' && ptr[3] != 0)) | |
781 | { | |
782 | errno = ERRNO_SMTPFORMAT; /* format error */ | |
783 | return FALSE; | |
784 | } | |
785 | ||
786 | /* If the line we have just read is a terminal line, line, we are done. | |
787 | Otherwise more data has to be read. */ | |
788 | ||
789 | if (ptr[3] != '-') break; | |
790 | ||
791 | /* Move the reading pointer upwards in the buffer and insert \n between the | |
792 | components of a multiline response. Space is left for this by read_response_ | |
793 | line(). */ | |
794 | ||
795 | ptr += count; | |
796 | *ptr++ = '\n'; | |
797 | size -= count + 1; | |
798 | } | |
799 | ||
ee8b8090 JH |
800 | #ifdef TCP_FASTOPEN |
801 | tfo_out_check(sx->cctx.sock); | |
802 | #endif | |
803 | ||
059ec3d9 PH |
804 | /* Return a value that depends on the SMTP return code. On some systems a |
805 | non-zero value of errno has been seen at this point, so ensure it is zero, | |
806 | because the caller of this function looks at errno when FALSE is returned, to | |
807 | distinguish between an unexpected return code and other errors such as | |
808 | timeouts, lost connections, etc. */ | |
809 | ||
810 | errno = 0; | |
811 | return buffer[0] == okdigit; | |
812 | } | |
813 | ||
814 | /* End of smtp_out.c */ | |
7eb6c37c JH |
815 | /* vi: aw ai sw=2 |
816 | */ |