Commit | Line | Data |
---|---|---|
059ec3d9 PH |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
f9ba5e22 | 5 | /* Copyright (c) University of Cambridge 1995 - 2018 */ |
1e1ddfac | 6 | /* Copyright (c) The Exim Maintainers 2020 */ |
059ec3d9 PH |
7 | /* See the file NOTICE for conditions of use and distribution. */ |
8 | ||
9 | /* A number of functions for driving outgoing SMTP calls. */ | |
10 | ||
11 | ||
12 | #include "exim.h" | |
7eb6c37c | 13 | #include "transports/smtp.h" |
059ec3d9 PH |
14 | |
15 | ||
16 | ||
17 | /************************************************* | |
18 | * Find an outgoing interface * | |
19 | *************************************************/ | |
20 | ||
21 | /* This function is called from the smtp transport and also from the callout | |
22 | code in verify.c. Its job is to expand a string to get a list of interfaces, | |
23 | and choose a suitable one (IPv4 or IPv6) for the outgoing address. | |
24 | ||
25 | Arguments: | |
26 | istring string interface setting, may be NULL, meaning "any", in | |
27 | which case the function does nothing | |
28 | host_af AF_INET or AF_INET6 for the outgoing IP address | |
29 | addr the mail address being handled (for setting errors) | |
059ec3d9 PH |
30 | interface point this to the interface |
31 | msg to add to any error message | |
32 | ||
33 | Returns: TRUE on success, FALSE on failure, with error message | |
34 | set in addr and transport_return set to PANIC | |
35 | */ | |
36 | ||
37 | BOOL | |
38 | smtp_get_interface(uschar *istring, int host_af, address_item *addr, | |
6f6dedcc | 39 | uschar **interface, uschar *msg) |
059ec3d9 | 40 | { |
55414b25 | 41 | const uschar * expint; |
059ec3d9 PH |
42 | uschar *iface; |
43 | int sep = 0; | |
44 | ||
fb05276a | 45 | if (!istring) return TRUE; |
059ec3d9 | 46 | |
fb05276a | 47 | if (!(expint = expand_string(istring))) |
059ec3d9 | 48 | { |
8768d548 | 49 | if (f.expand_string_forcedfail) return TRUE; |
059ec3d9 PH |
50 | addr->transport_return = PANIC; |
51 | addr->message = string_sprintf("failed to expand \"interface\" " | |
52 | "option for %s: %s", msg, expand_string_message); | |
53 | return FALSE; | |
54 | } | |
55 | ||
f3ebb786 JH |
56 | if (is_tainted(expint)) |
57 | { | |
58 | log_write(0, LOG_MAIN|LOG_PANIC, | |
59 | "attempt to use tainted value '%s' from '%s' for interface", | |
60 | expint, istring); | |
61 | addr->transport_return = PANIC; | |
62 | addr->message = string_sprintf("failed to expand \"interface\" " | |
63 | "option for %s: configuration error", msg); | |
64 | return FALSE; | |
65 | } | |
66 | ||
137ae145 JH |
67 | Uskip_whitespace(&expint); |
68 | if (!*expint) return TRUE; | |
059ec3d9 PH |
69 | |
70 | while ((iface = string_nextinlist(&expint, &sep, big_buffer, | |
fb05276a | 71 | big_buffer_size))) |
059ec3d9 PH |
72 | { |
73 | if (string_is_ip_address(iface, NULL) == 0) | |
74 | { | |
75 | addr->transport_return = PANIC; | |
76 | addr->message = string_sprintf("\"%s\" is not a valid IP " | |
77 | "address for the \"interface\" option for %s", | |
78 | iface, msg); | |
79 | return FALSE; | |
80 | } | |
81 | ||
82 | if (((Ustrchr(iface, ':') == NULL)? AF_INET:AF_INET6) == host_af) | |
83 | break; | |
84 | } | |
85 | ||
fb05276a | 86 | if (iface) *interface = string_copy(iface); |
059ec3d9 PH |
87 | return TRUE; |
88 | } | |
89 | ||
90 | ||
91 | ||
92 | /************************************************* | |
93 | * Find an outgoing port * | |
94 | *************************************************/ | |
95 | ||
96 | /* This function is called from the smtp transport and also from the callout | |
97 | code in verify.c. Its job is to find a port number. Note that getservbyname() | |
98 | produces the number in network byte order. | |
99 | ||
100 | Arguments: | |
101 | rstring raw (unexpanded) string representation of the port | |
102 | addr the mail address being handled (for setting errors) | |
103 | port stick the port in here | |
104 | msg for adding to error message | |
105 | ||
106 | Returns: TRUE on success, FALSE on failure, with error message set | |
107 | in addr, and transport_return set to PANIC | |
108 | */ | |
109 | ||
110 | BOOL | |
111 | smtp_get_port(uschar *rstring, address_item *addr, int *port, uschar *msg) | |
112 | { | |
113 | uschar *pstring = expand_string(rstring); | |
114 | ||
00580051 | 115 | if (!pstring) |
059ec3d9 PH |
116 | { |
117 | addr->transport_return = PANIC; | |
118 | addr->message = string_sprintf("failed to expand \"%s\" (\"port\" option) " | |
119 | "for %s: %s", rstring, msg, expand_string_message); | |
120 | return FALSE; | |
121 | } | |
122 | ||
123 | if (isdigit(*pstring)) | |
124 | { | |
125 | uschar *end; | |
126 | *port = Ustrtol(pstring, &end, 0); | |
127 | if (end != pstring + Ustrlen(pstring)) | |
128 | { | |
129 | addr->transport_return = PANIC; | |
130 | addr->message = string_sprintf("invalid port number for %s: %s", msg, | |
131 | pstring); | |
132 | return FALSE; | |
133 | } | |
134 | } | |
135 | ||
136 | else | |
137 | { | |
138 | struct servent *smtp_service = getservbyname(CS pstring, "tcp"); | |
00580051 | 139 | if (!smtp_service) |
059ec3d9 PH |
140 | { |
141 | addr->transport_return = PANIC; | |
142 | addr->message = string_sprintf("TCP port \"%s\" is not defined for %s", | |
143 | pstring, msg); | |
144 | return FALSE; | |
145 | } | |
146 | *port = ntohs(smtp_service->s_port); | |
147 | } | |
148 | ||
149 | return TRUE; | |
150 | } | |
151 | ||
152 | ||
153 | ||
154 | ||
1ccd5f67 JH |
155 | #ifdef TCP_FASTOPEN |
156 | static void | |
157 | tfo_out_check(int sock) | |
158 | { | |
53c7b3a7 | 159 | # ifdef __FreeBSD__ |
1ccd5f67 | 160 | struct tcp_info tinfo; |
73a10da9 JH |
161 | int val; |
162 | socklen_t len = sizeof(val); | |
163 | ||
73a10da9 JH |
164 | /* The observability as of 12.1 is not useful as a client, only telling us that |
165 | a TFO option was used on SYN. It could have been a TFO-R, or ignored by the | |
166 | server. */ | |
167 | ||
168 | /* | |
169 | if (tcp_out_fastopen == TFO_ATTEMPTED_NODATA || tcp_out_fastopen == TFO_ATTEMPTED_DATA) | |
170 | if (getsockopt(sock, IPPROTO_TCP, TCP_FASTOPEN, &val, &len) == 0 && val != 0) {} | |
171 | */ | |
172 | switch (tcp_out_fastopen) | |
173 | { | |
174 | case TFO_ATTEMPTED_NODATA: tcp_out_fastopen = TFO_USED_NODATA; break; | |
175 | case TFO_ATTEMPTED_DATA: tcp_out_fastopen = TFO_USED_DATA; break; | |
176 | default: break; /* compiler quietening */ | |
177 | } | |
178 | ||
179 | # else /* Linux & Apple */ | |
180 | # if defined(TCP_INFO) && defined(EXIM_HAVE_TCPI_UNACKED) | |
53c7b3a7 JH |
181 | struct tcp_info tinfo; |
182 | socklen_t len = sizeof(tinfo); | |
1ccd5f67 | 183 | |
ee8b8090 JH |
184 | switch (tcp_out_fastopen) |
185 | { | |
186 | /* This is a somewhat dubious detection method; totally undocumented so likely | |
187 | to fail in future kernels. There seems to be no documented way. What we really | |
188 | want to know is if the server sent smtp-banner data before our ACK of his SYN,ACK | |
189 | hit him. What this (possibly?) detects is whether we sent a TFO cookie with our | |
190 | SYN, as distinct from a TFO request. This gets a false-positive when the server | |
191 | key is rotated; we send the old one (which this test sees) but the server returns | |
192 | the new one and does not send its SMTP banner before we ACK his SYN,ACK. | |
193 | To force that rotation case: | |
194 | '# echo -n "00000000-00000000-00000000-0000000" >/proc/sys/net/ipv4/tcp_fastopen_key' | |
195 | The kernel seems to be counting unack'd packets. */ | |
196 | ||
197 | case TFO_ATTEMPTED_NODATA: | |
198 | if ( getsockopt(sock, IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0 | |
199 | && tinfo.tcpi_state == TCP_SYN_SENT | |
200 | && tinfo.tcpi_unacked > 1 | |
201 | ) | |
202 | { | |
203 | DEBUG(D_transport|D_v) | |
204 | debug_printf("TCP_FASTOPEN tcpi_unacked %d\n", tinfo.tcpi_unacked); | |
205 | tcp_out_fastopen = TFO_USED_NODATA; | |
206 | } | |
207 | break; | |
1ccd5f67 | 208 | |
ee8b8090 JH |
209 | /* When called after waiting for received data we should be able |
210 | to tell if data we sent was accepted. */ | |
1ccd5f67 | 211 | |
ee8b8090 JH |
212 | case TFO_ATTEMPTED_DATA: |
213 | if ( getsockopt(sock, IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0 | |
214 | && tinfo.tcpi_state == TCP_ESTABLISHED | |
215 | ) | |
216 | if (tinfo.tcpi_options & TCPI_OPT_SYN_DATA) | |
217 | { | |
218 | DEBUG(D_transport|D_v) debug_printf("TFO: data was acked\n"); | |
219 | tcp_out_fastopen = TFO_USED_DATA; | |
220 | } | |
221 | else | |
1ccd5f67 JH |
222 | { |
223 | DEBUG(D_transport|D_v) debug_printf("TFO: had to retransmit\n"); | |
06e272a3 | 224 | tcp_out_fastopen = TFO_NOT_USED; |
1ccd5f67 | 225 | } |
ee8b8090 | 226 | break; |
56dbf856 JH |
227 | |
228 | default: break; /* compiler quietening */ | |
ee8b8090 | 229 | } |
73a10da9 JH |
230 | # endif |
231 | # endif /* Linux & Apple */ | |
1ccd5f67 JH |
232 | } |
233 | #endif | |
234 | ||
235 | ||
0ab63f3d | 236 | /* Arguments as for smtp_connect(), plus |
b536a578 JH |
237 | early_data if non-NULL, idenmpotent data to be sent - |
238 | preferably in the TCP SYN segment | |
0ab63f3d JH |
239 | |
240 | Returns: connected socket number, or -1 with errno set | |
241 | */ | |
242 | ||
059ec3d9 | 243 | int |
7eb6c37c | 244 | smtp_sock_connect(host_item * host, int host_af, int port, uschar * interface, |
0ab63f3d | 245 | transport_instance * tb, int timeout, const blob * early_data) |
059ec3d9 | 246 | { |
7eb6c37c JH |
247 | smtp_transport_options_block * ob = |
248 | (smtp_transport_options_block *)tb->options_block; | |
249 | const uschar * dscp = ob->dscp; | |
9e4f5962 PP |
250 | int dscp_value; |
251 | int dscp_level; | |
252 | int dscp_option; | |
059ec3d9 | 253 | int sock; |
7eb6c37c | 254 | int save_errno = 0; |
10ac8d7f | 255 | const blob * fastopen_blob = NULL; |
1ccd5f67 | 256 | |
059ec3d9 | 257 | |
0cbf2b82 | 258 | #ifndef DISABLE_EVENT |
7eb6c37c JH |
259 | deliver_host_address = host->address; |
260 | deliver_host_port = port; | |
261 | if (event_raise(tb->event_action, US"tcp:connect", NULL)) return -1; | |
a7538db1 JH |
262 | #endif |
263 | ||
059ec3d9 PH |
264 | if ((sock = ip_socket(SOCK_STREAM, host_af)) < 0) return -1; |
265 | ||
266 | /* Set TCP_NODELAY; Exim does its own buffering. */ | |
267 | ||
d4ff61d1 JH |
268 | if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, US &on, sizeof(on))) |
269 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 270 | debug_printf_indent("failed to set NODELAY: %s ", strerror(errno)); |
059ec3d9 | 271 | |
9e4f5962 PP |
272 | /* Set DSCP value, if we can. For now, if we fail to set the value, we don't |
273 | bomb out, just log it and continue in default traffic class. */ | |
274 | ||
275 | if (dscp && dscp_lookup(dscp, host_af, &dscp_level, &dscp_option, &dscp_value)) | |
276 | { | |
277 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 278 | debug_printf_indent("DSCP \"%s\"=%x ", dscp, dscp_value); |
9e4f5962 PP |
279 | if (setsockopt(sock, dscp_level, dscp_option, &dscp_value, sizeof(dscp_value)) < 0) |
280 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 281 | debug_printf_indent("failed to set DSCP: %s ", strerror(errno)); |
9e4f5962 PP |
282 | /* If the kernel supports IPv4 and IPv6 on an IPv6 socket, we need to set the |
283 | option for both; ignore failures here */ | |
284 | if (host_af == AF_INET6 && | |
285 | dscp_lookup(dscp, AF_INET, &dscp_level, &dscp_option, &dscp_value)) | |
9e4f5962 | 286 | (void) setsockopt(sock, dscp_level, dscp_option, &dscp_value, sizeof(dscp_value)); |
9e4f5962 PP |
287 | } |
288 | ||
059ec3d9 PH |
289 | /* Bind to a specific interface if requested. Caller must ensure the interface |
290 | is the same type (IPv4 or IPv6) as the outgoing address. */ | |
291 | ||
7eb6c37c | 292 | if (interface && ip_bind(sock, host_af, interface, 0) < 0) |
059ec3d9 PH |
293 | { |
294 | save_errno = errno; | |
295 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 296 | debug_printf_indent("unable to bind outgoing SMTP call to %s: %s", interface, |
059ec3d9 PH |
297 | strerror(errno)); |
298 | } | |
299 | ||
300 | /* Connect to the remote host, and add keepalive to the socket before returning | |
0ab63f3d | 301 | it, if requested. If the build supports TFO, request it - and if the caller |
ee8b8090 JH |
302 | requested some early-data then include that in the TFO request. If there is |
303 | early-data but no TFO support, send it after connecting. */ | |
059ec3d9 | 304 | |
0ab63f3d JH |
305 | else |
306 | { | |
0ab63f3d | 307 | #ifdef TCP_FASTOPEN |
3fb3231c | 308 | if (verify_check_given_host(CUSS &ob->hosts_try_fastopen, host) == OK) |
10ac8d7f | 309 | fastopen_blob = early_data ? early_data : &tcp_fastopen_nodata; |
0ab63f3d JH |
310 | #endif |
311 | ||
10ac8d7f | 312 | if (ip_connect(sock, host_af, host->address, port, timeout, fastopen_blob) < 0) |
0ab63f3d | 313 | save_errno = errno; |
10ac8d7f | 314 | else if (early_data && !fastopen_blob && early_data->data && early_data->len) |
ee8b8090 JH |
315 | { |
316 | HDEBUG(D_transport|D_acl|D_v) | |
317 | debug_printf("sending %ld nonTFO early-data\n", (long)early_data->len); | |
318 | ||
319 | #ifdef TCP_QUICKACK | |
320 | (void) setsockopt(sock, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off)); | |
321 | #endif | |
0ab63f3d JH |
322 | if (send(sock, early_data->data, early_data->len, 0) < 0) |
323 | save_errno = errno; | |
ee8b8090 | 324 | } |
0ab63f3d | 325 | } |
059ec3d9 PH |
326 | |
327 | /* Either bind() or connect() failed */ | |
328 | ||
329 | if (save_errno != 0) | |
330 | { | |
8e669ac1 | 331 | HDEBUG(D_transport|D_acl|D_v) |
4deaf07d | 332 | { |
adb21834 | 333 | debug_printf_indent(" failed: %s", CUstrerror(save_errno)); |
8e669ac1 | 334 | if (save_errno == ETIMEDOUT) |
4deaf07d | 335 | debug_printf(" (timeout=%s)", readconf_printtime(timeout)); |
8e669ac1 PH |
336 | debug_printf("\n"); |
337 | } | |
f1e894f3 | 338 | (void)close(sock); |
059ec3d9 PH |
339 | errno = save_errno; |
340 | return -1; | |
341 | } | |
342 | ||
ee8b8090 | 343 | /* Both bind() and connect() succeeded, and any early-data */ |
059ec3d9 PH |
344 | |
345 | else | |
346 | { | |
41c7c167 PH |
347 | union sockaddr_46 interface_sock; |
348 | EXIM_SOCKLEN_T size = sizeof(interface_sock); | |
ee8b8090 | 349 | |
adb21834 | 350 | HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" connected\n"); |
41c7c167 PH |
351 | if (getsockname(sock, (struct sockaddr *)(&interface_sock), &size) == 0) |
352 | sending_ip_address = host_ntoa(-1, &interface_sock, NULL, &sending_port); | |
353 | else | |
354 | { | |
355 | log_write(0, LOG_MAIN | ((errno == ECONNRESET)? 0 : LOG_PANIC), | |
356 | "getsockname() failed: %s", strerror(errno)); | |
357 | close(sock); | |
358 | return -1; | |
359 | } | |
ee8b8090 | 360 | |
7eb6c37c | 361 | if (ob->keepalive) ip_keepalive(sock, host->address, TRUE); |
1ccd5f67 | 362 | #ifdef TCP_FASTOPEN |
ee8b8090 | 363 | tfo_out_check(sock); |
1ccd5f67 | 364 | #endif |
059ec3d9 PH |
365 | return sock; |
366 | } | |
367 | } | |
368 | ||
58c30e47 JH |
369 | |
370 | ||
371 | ||
372 | ||
373 | void | |
374 | smtp_port_for_connect(host_item * host, int port) | |
375 | { | |
376 | if (host->port != PORT_NONE) | |
377 | { | |
378 | HDEBUG(D_transport|D_acl|D_v) | |
379 | debug_printf_indent("Transport port=%d replaced by host-specific port=%d\n", port, | |
380 | host->port); | |
381 | port = host->port; | |
382 | } | |
383 | else host->port = port; /* Set the port actually used */ | |
384 | } | |
385 | ||
386 | ||
7eb6c37c JH |
387 | /************************************************* |
388 | * Connect to remote host * | |
389 | *************************************************/ | |
390 | ||
391 | /* Create a socket, and connect it to a remote host. IPv6 addresses are | |
392 | detected by checking for a colon in the address. AF_INET6 is defined even on | |
393 | non-IPv6 systems, to enable the code to be less messy. However, on such systems | |
394 | host->address will always be an IPv4 address. | |
395 | ||
7eb6c37c | 396 | Arguments: |
ee8b8090 JH |
397 | sc details for making connection: host, af, interface, transport |
398 | early_data if non-NULL, data to be sent - preferably in the TCP SYN segment | |
7eb6c37c JH |
399 | |
400 | Returns: connected socket number, or -1 with errno set | |
401 | */ | |
402 | ||
403 | int | |
ee8b8090 | 404 | smtp_connect(smtp_connect_args * sc, const blob * early_data) |
7eb6c37c | 405 | { |
ee8b8090 JH |
406 | int port = sc->host->port; |
407 | smtp_transport_options_block * ob = sc->ob; | |
7eb6c37c | 408 | |
ee8b8090 | 409 | callout_address = string_sprintf("[%s]:%d", sc->host->address, port); |
055e2cb4 | 410 | |
7eb6c37c JH |
411 | HDEBUG(D_transport|D_acl|D_v) |
412 | { | |
413 | uschar * s = US" "; | |
ee8b8090 | 414 | if (sc->interface) s = string_sprintf(" from %s ", sc->interface); |
f0989ec0 | 415 | #ifdef SUPPORT_SOCKS |
7eb6c37c JH |
416 | if (ob->socks_proxy) s = string_sprintf("%svia proxy ", s); |
417 | #endif | |
ee8b8090 | 418 | debug_printf_indent("Connecting to %s %s%s... ", sc->host->name, callout_address, s); |
7eb6c37c JH |
419 | } |
420 | ||
421 | /* Create and connect the socket */ | |
422 | ||
f0989ec0 | 423 | #ifdef SUPPORT_SOCKS |
7eb6c37c | 424 | if (ob->socks_proxy) |
ee8b8090 JH |
425 | { |
426 | int sock = socks_sock_connect(sc->host, sc->host_af, port, sc->interface, | |
427 | sc->tblock, ob->connect_timeout); | |
428 | ||
429 | if (sock >= 0) | |
430 | { | |
431 | if (early_data && early_data->data && early_data->len) | |
432 | if (send(sock, early_data->data, early_data->len, 0) < 0) | |
433 | { | |
434 | int save_errno = errno; | |
435 | HDEBUG(D_transport|D_acl|D_v) | |
436 | { | |
437 | debug_printf_indent("failed: %s", CUstrerror(save_errno)); | |
438 | if (save_errno == ETIMEDOUT) | |
439 | debug_printf(" (timeout=%s)", readconf_printtime(ob->connect_timeout)); | |
440 | debug_printf("\n"); | |
441 | } | |
442 | (void)close(sock); | |
443 | sock = -1; | |
444 | errno = save_errno; | |
445 | } | |
446 | } | |
447 | return sock; | |
448 | } | |
7eb6c37c JH |
449 | #endif |
450 | ||
ee8b8090 JH |
451 | return smtp_sock_connect(sc->host, sc->host_af, port, sc->interface, |
452 | sc->tblock, ob->connect_timeout, early_data); | |
7eb6c37c JH |
453 | } |
454 | ||
059ec3d9 PH |
455 | |
456 | /************************************************* | |
457 | * Flush outgoing command buffer * | |
458 | *************************************************/ | |
459 | ||
460 | /* This function is called only from smtp_write_command() below. It flushes | |
461 | the buffer of outgoing commands. There is more than one in the buffer only when | |
462 | pipelining. | |
463 | ||
464 | Argument: | |
465 | outblock the SMTP output block | |
925ac8e4 | 466 | mode further data expected, or plain |
059ec3d9 PH |
467 | |
468 | Returns: TRUE if OK, FALSE on error, with errno set | |
469 | */ | |
470 | ||
471 | static BOOL | |
4e910c01 | 472 | flush_buffer(smtp_outblock * outblock, int mode) |
059ec3d9 PH |
473 | { |
474 | int rc; | |
58fc5fb2 | 475 | int n = outblock->ptr - outblock->buffer; |
925ac8e4 | 476 | BOOL more = mode == SCMD_MORE; |
059ec3d9 | 477 | |
4e910c01 | 478 | HDEBUG(D_transport|D_acl) debug_printf_indent("cmd buf flush %d bytes%s\n", n, |
925ac8e4 | 479 | more ? " (more expected)" : ""); |
4e910c01 | 480 | |
01603eec | 481 | #ifndef DISABLE_TLS |
74f1a423 JH |
482 | if (outblock->cctx->tls_ctx) |
483 | rc = tls_write(outblock->cctx->tls_ctx, outblock->buffer, n, more); | |
059ec3d9 PH |
484 | else |
485 | #endif | |
ee8b8090 JH |
486 | |
487 | { | |
488 | if (outblock->conn_args) | |
489 | { | |
490 | blob early_data = { .data = outblock->buffer, .len = n }; | |
491 | ||
492 | /* We ignore the more-flag if we're doing a connect with early-data, which | |
493 | means we won't get BDAT+data. A pity, but wise due to the idempotency | |
494 | requirement: TFO with data can, in rare cases, replay the data to the | |
495 | receiver. */ | |
496 | ||
497 | if ( (outblock->cctx->sock = smtp_connect(outblock->conn_args, &early_data)) | |
498 | < 0) | |
499 | return FALSE; | |
500 | outblock->conn_args = NULL; | |
501 | rc = n; | |
502 | } | |
503 | else | |
ff966302 | 504 | { |
ee8b8090 | 505 | rc = send(outblock->cctx->sock, outblock->buffer, n, |
4e910c01 | 506 | #ifdef MSG_MORE |
ee8b8090 | 507 | more ? MSG_MORE : 0 |
4e910c01 | 508 | #else |
ee8b8090 | 509 | 0 |
4e910c01 | 510 | #endif |
ee8b8090 | 511 | ); |
ff966302 | 512 | } |
ee8b8090 | 513 | } |
059ec3d9 | 514 | |
059ec3d9 PH |
515 | if (rc <= 0) |
516 | { | |
e1d04f48 | 517 | HDEBUG(D_transport|D_acl) debug_printf_indent("send failed: %s\n", strerror(errno)); |
059ec3d9 PH |
518 | return FALSE; |
519 | } | |
520 | ||
521 | outblock->ptr = outblock->buffer; | |
522 | outblock->cmd_count = 0; | |
523 | return TRUE; | |
524 | } | |
525 | ||
526 | ||
527 | ||
528 | /************************************************* | |
529 | * Write SMTP command * | |
530 | *************************************************/ | |
531 | ||
532 | /* The formatted command is left in big_buffer so that it can be reflected in | |
533 | any error message. | |
534 | ||
535 | Arguments: | |
251b9eb4 | 536 | sx SMTP connection, contains buffer for pipelining, and socket |
4e910c01 | 537 | mode buffer, write-with-more-likely, write |
059ec3d9 PH |
538 | format a format, starting with one of |
539 | of HELO, MAIL FROM, RCPT TO, DATA, ".", or QUIT. | |
6d5c916c | 540 | If NULL, flush pipeline buffer only. |
059ec3d9 PH |
541 | ... data for the format |
542 | ||
543 | Returns: 0 if command added to pipelining buffer, with nothing transmitted | |
544 | +n if n commands transmitted (may still have buffered the new one) | |
545 | -1 on error, with errno set | |
546 | */ | |
547 | ||
548 | int | |
251b9eb4 | 549 | smtp_write_command(void * sx, int mode, const char *format, ...) |
059ec3d9 | 550 | { |
251b9eb4 | 551 | smtp_outblock * outblock = &((smtp_context *)sx)->outblock; |
059ec3d9 | 552 | int rc = 0; |
059ec3d9 | 553 | |
6d5c916c | 554 | if (format) |
059ec3d9 | 555 | { |
d12746bc JH |
556 | gstring gs = { .size = big_buffer_size, .ptr = 0, .s = big_buffer }; |
557 | va_list ap; | |
558 | ||
f3ebb786 JH |
559 | /* Use taint-unchecked routines for writing into big_buffer, trusting that |
560 | we'll never expand the results. Actually, the error-message use - leaving | |
561 | the results in big_buffer for potential later use - is uncomfortably distant. | |
562 | XXX Would be better to assume all smtp commands are short, use normal pool | |
563 | alloc rather than big_buffer, and another global for the data-for-error. */ | |
564 | ||
6d5c916c | 565 | va_start(ap, format); |
f3ebb786 | 566 | if (!string_vformat(&gs, SVFMT_TAINT_NOCHK, CS format, ap)) |
6d5c916c JH |
567 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong write_command in outgoing " |
568 | "SMTP"); | |
569 | va_end(ap); | |
d12746bc | 570 | string_from_gstring(&gs); |
6d5c916c | 571 | |
d12746bc | 572 | if (gs.ptr > outblock->buffersize) |
6d5c916c JH |
573 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong write_command in outgoing " |
574 | "SMTP"); | |
575 | ||
d12746bc | 576 | if (gs.ptr > outblock->buffersize - (outblock->ptr - outblock->buffer)) |
6d5c916c JH |
577 | { |
578 | rc = outblock->cmd_count; /* flush resets */ | |
4e910c01 | 579 | if (!flush_buffer(outblock, SCMD_FLUSH)) return -1; |
6d5c916c | 580 | } |
059ec3d9 | 581 | |
f3ebb786 | 582 | Ustrncpy(outblock->ptr, gs.s, gs.ptr); |
d12746bc | 583 | outblock->ptr += gs.ptr; |
6d5c916c | 584 | outblock->cmd_count++; |
d12746bc | 585 | gs.ptr -= 2; string_from_gstring(&gs); /* remove \r\n for error message */ |
059ec3d9 | 586 | |
6d5c916c JH |
587 | /* We want to hide the actual data sent in AUTH transactions from reflections |
588 | and logs. While authenticating, a flag is set in the outblock to enable this. | |
589 | The AUTH command itself gets any data flattened. Other lines are flattened | |
590 | completely. */ | |
059ec3d9 | 591 | |
6d5c916c | 592 | if (outblock->authenticating) |
059ec3d9 | 593 | { |
6d5c916c JH |
594 | uschar *p = big_buffer; |
595 | if (Ustrncmp(big_buffer, "AUTH ", 5) == 0) | |
596 | { | |
597 | p += 5; | |
598 | while (isspace(*p)) p++; | |
599 | while (!isspace(*p)) p++; | |
600 | while (isspace(*p)) p++; | |
601 | } | |
602 | while (*p != 0) *p++ = '*'; | |
059ec3d9 | 603 | } |
059ec3d9 | 604 | |
e1d04f48 | 605 | HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> %s\n", big_buffer); |
6d5c916c | 606 | } |
059ec3d9 | 607 | |
4e910c01 | 608 | if (mode != SCMD_BUFFER) |
059ec3d9 PH |
609 | { |
610 | rc += outblock->cmd_count; /* flush resets */ | |
4e910c01 | 611 | if (!flush_buffer(outblock, mode)) return -1; |
059ec3d9 PH |
612 | } |
613 | ||
614 | return rc; | |
615 | } | |
616 | ||
617 | ||
618 | ||
619 | /************************************************* | |
620 | * Read one line of SMTP response * | |
621 | *************************************************/ | |
622 | ||
623 | /* This function reads one line of SMTP response from the server host. This may | |
624 | not be a complete response - it could be just part of a multiline response. We | |
625 | have to use a buffer for incoming packets, because when pipelining or using | |
626 | LMTP, there may well be more than one response in a single packet. This | |
627 | function is called only from the one that follows. | |
628 | ||
629 | Arguments: | |
630 | inblock the SMTP input block (contains holding buffer, socket, etc.) | |
631 | buffer where to put the line | |
632 | size space available for the line | |
0a5441fc | 633 | timelimit deadline for reading the lime, seconds past epoch |
059ec3d9 PH |
634 | |
635 | Returns: length of a line that has been put in the buffer | |
636 | -1 otherwise, with errno set | |
637 | */ | |
638 | ||
639 | static int | |
0a5441fc | 640 | read_response_line(smtp_inblock *inblock, uschar *buffer, int size, time_t timelimit) |
059ec3d9 PH |
641 | { |
642 | uschar *p = buffer; | |
643 | uschar *ptr = inblock->ptr; | |
644 | uschar *ptrend = inblock->ptrend; | |
74f1a423 | 645 | client_conn_ctx * cctx = inblock->cctx; |
059ec3d9 PH |
646 | |
647 | /* Loop for reading multiple packets or reading another packet after emptying | |
648 | a previously-read one. */ | |
649 | ||
650 | for (;;) | |
651 | { | |
652 | int rc; | |
653 | ||
654 | /* If there is data in the input buffer left over from last time, copy | |
655 | characters from it until the end of a line, at which point we can return, | |
656 | having removed any whitespace (which will include CR) at the end of the line. | |
657 | The rules for SMTP say that lines end in CRLF, but there are have been cases | |
658 | of hosts using just LF, and other MTAs are reported to handle this, so we | |
659 | just look for LF. If we run out of characters before the end of a line, | |
660 | carry on to read the next incoming packet. */ | |
661 | ||
662 | while (ptr < ptrend) | |
663 | { | |
664 | int c = *ptr++; | |
665 | if (c == '\n') | |
666 | { | |
667 | while (p > buffer && isspace(p[-1])) p--; | |
668 | *p = 0; | |
669 | inblock->ptr = ptr; | |
670 | return p - buffer; | |
671 | } | |
672 | *p++ = c; | |
673 | if (--size < 4) | |
674 | { | |
675 | *p = 0; /* Leave malformed line for error message */ | |
676 | errno = ERRNO_SMTPFORMAT; | |
677 | return -1; | |
678 | } | |
679 | } | |
680 | ||
681 | /* Need to read a new input packet. */ | |
682 | ||
0a5441fc | 683 | if((rc = ip_recv(cctx, inblock->buffer, inblock->buffersize, timelimit)) <= 0) |
de6273b4 | 684 | { |
eebcfa1c | 685 | DEBUG(D_deliver|D_transport|D_acl|D_v) |
170f4904 JH |
686 | debug_printf_indent(errno ? " SMTP(%s)<<\n" : " SMTP(closed)<<\n", |
687 | strerror(errno)); | |
de6273b4 JH |
688 | break; |
689 | } | |
059ec3d9 PH |
690 | |
691 | /* Another block of data has been successfully read. Set up the pointers | |
692 | and let the loop continue. */ | |
693 | ||
694 | ptrend = inblock->ptrend = inblock->buffer + rc; | |
695 | ptr = inblock->buffer; | |
e1d04f48 | 696 | DEBUG(D_transport|D_acl) debug_printf_indent("read response data: size=%d\n", rc); |
059ec3d9 PH |
697 | } |
698 | ||
699 | /* Get here if there has been some kind of recv() error; errno is set, but we | |
700 | ensure that the result buffer is empty before returning. */ | |
701 | ||
702 | *buffer = 0; | |
703 | return -1; | |
704 | } | |
705 | ||
706 | ||
707 | ||
708 | ||
709 | ||
710 | /************************************************* | |
711 | * Read SMTP response * | |
712 | *************************************************/ | |
713 | ||
714 | /* This function reads an SMTP response with a timeout, and returns the | |
715 | response in the given buffer, as a string. A multiline response will contain | |
716 | newline characters between the lines. The function also analyzes the first | |
717 | digit of the reply code and returns FALSE if it is not acceptable. FALSE is | |
718 | also returned after a reading error. In this case buffer[0] will be zero, and | |
719 | the error code will be in errno. | |
720 | ||
721 | Arguments: | |
251b9eb4 JH |
722 | sx the SMTP connection (contains input block with holding buffer, |
723 | socket, etc.) | |
059ec3d9 PH |
724 | buffer where to put the response |
725 | size the size of the buffer | |
726 | okdigit the expected first digit of the response | |
2760b518 | 727 | timeout the timeout to use, in seconds |
059ec3d9 PH |
728 | |
729 | Returns: TRUE if a valid, non-error response was received; else FALSE | |
730 | */ | |
ee8b8090 | 731 | /*XXX could move to smtp transport; no other users */ |
059ec3d9 PH |
732 | |
733 | BOOL | |
fc243e94 | 734 | smtp_read_response(void * sx0, uschar * buffer, int size, int okdigit, |
059ec3d9 PH |
735 | int timeout) |
736 | { | |
ee8b8090 | 737 | smtp_context * sx = sx0; |
fc243e94 | 738 | uschar * ptr = buffer; |
dca6d121 | 739 | int count = 0; |
0a5441fc | 740 | time_t timelimit = time(NULL) + timeout; |
059ec3d9 PH |
741 | |
742 | errno = 0; /* Ensure errno starts out zero */ | |
743 | ||
81344b40 | 744 | #ifndef DISABLE_PIPE_CONNECT |
ee8b8090 | 745 | if (sx->pending_BANNER || sx->pending_EHLO) |
dca6d121 JH |
746 | { |
747 | int rc; | |
fc243e94 | 748 | if ((rc = smtp_reap_early_pipe(sx, &count)) != OK) |
ee8b8090 JH |
749 | { |
750 | DEBUG(D_transport) debug_printf("failed reaping pipelined cmd responsess\n"); | |
fc243e94 JH |
751 | buffer[0] = '\0'; |
752 | if (rc == DEFER) errno = ERRNO_TLSFAILURE; | |
ee8b8090 JH |
753 | return FALSE; |
754 | } | |
dca6d121 | 755 | } |
ee8b8090 JH |
756 | #endif |
757 | ||
4c04137d | 758 | /* This is a loop to read and concatenate the lines that make up a multi-line |
059ec3d9 PH |
759 | response. */ |
760 | ||
761 | for (;;) | |
762 | { | |
0a5441fc | 763 | if ((count = read_response_line(&sx->inblock, ptr, size, timelimit)) < 0) |
059ec3d9 PH |
764 | return FALSE; |
765 | ||
766 | HDEBUG(D_transport|D_acl|D_v) | |
ee8b8090 | 767 | debug_printf_indent(" %s %s\n", ptr == buffer ? "SMTP<<" : " ", ptr); |
059ec3d9 PH |
768 | |
769 | /* Check the format of the response: it must start with three digits; if | |
770 | these are followed by a space or end of line, the response is complete. If | |
771 | they are followed by '-' this is a multi-line response and we must look for | |
772 | another line until the final line is reached. The only use made of multi-line | |
773 | responses is to pass them back as error messages. We therefore just | |
774 | concatenate them all within the buffer, which should be large enough to | |
775 | accept any reasonable number of lines. */ | |
776 | ||
777 | if (count < 3 || | |
778 | !isdigit(ptr[0]) || | |
779 | !isdigit(ptr[1]) || | |
780 | !isdigit(ptr[2]) || | |
781 | (ptr[3] != '-' && ptr[3] != ' ' && ptr[3] != 0)) | |
782 | { | |
783 | errno = ERRNO_SMTPFORMAT; /* format error */ | |
784 | return FALSE; | |
785 | } | |
786 | ||
787 | /* If the line we have just read is a terminal line, line, we are done. | |
788 | Otherwise more data has to be read. */ | |
789 | ||
790 | if (ptr[3] != '-') break; | |
791 | ||
792 | /* Move the reading pointer upwards in the buffer and insert \n between the | |
793 | components of a multiline response. Space is left for this by read_response_ | |
794 | line(). */ | |
795 | ||
796 | ptr += count; | |
797 | *ptr++ = '\n'; | |
798 | size -= count + 1; | |
799 | } | |
800 | ||
ee8b8090 JH |
801 | #ifdef TCP_FASTOPEN |
802 | tfo_out_check(sx->cctx.sock); | |
803 | #endif | |
804 | ||
059ec3d9 PH |
805 | /* Return a value that depends on the SMTP return code. On some systems a |
806 | non-zero value of errno has been seen at this point, so ensure it is zero, | |
807 | because the caller of this function looks at errno when FALSE is returned, to | |
808 | distinguish between an unexpected return code and other errors such as | |
809 | timeouts, lost connections, etc. */ | |
810 | ||
811 | errno = 0; | |
812 | return buffer[0] == okdigit; | |
813 | } | |
814 | ||
815 | /* End of smtp_out.c */ | |
7eb6c37c JH |
816 | /* vi: aw ai sw=2 |
817 | */ |