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 | ||
059ec3d9 PH |
66 | while (isspace(*expint)) expint++; |
67 | if (*expint == 0) return TRUE; | |
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 | { | |
158 | # if defined(TCP_INFO) && defined(EXIM_HAVE_TCPI_UNACKED) | |
159 | struct tcp_info tinfo; | |
160 | socklen_t len = sizeof(tinfo); | |
161 | ||
ee8b8090 JH |
162 | switch (tcp_out_fastopen) |
163 | { | |
164 | /* This is a somewhat dubious detection method; totally undocumented so likely | |
165 | to fail in future kernels. There seems to be no documented way. What we really | |
166 | want to know is if the server sent smtp-banner data before our ACK of his SYN,ACK | |
167 | hit him. What this (possibly?) detects is whether we sent a TFO cookie with our | |
168 | SYN, as distinct from a TFO request. This gets a false-positive when the server | |
169 | key is rotated; we send the old one (which this test sees) but the server returns | |
170 | the new one and does not send its SMTP banner before we ACK his SYN,ACK. | |
171 | To force that rotation case: | |
172 | '# echo -n "00000000-00000000-00000000-0000000" >/proc/sys/net/ipv4/tcp_fastopen_key' | |
173 | The kernel seems to be counting unack'd packets. */ | |
174 | ||
175 | case TFO_ATTEMPTED_NODATA: | |
176 | if ( getsockopt(sock, IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0 | |
177 | && tinfo.tcpi_state == TCP_SYN_SENT | |
178 | && tinfo.tcpi_unacked > 1 | |
179 | ) | |
180 | { | |
181 | DEBUG(D_transport|D_v) | |
182 | debug_printf("TCP_FASTOPEN tcpi_unacked %d\n", tinfo.tcpi_unacked); | |
183 | tcp_out_fastopen = TFO_USED_NODATA; | |
184 | } | |
185 | break; | |
1ccd5f67 | 186 | |
ee8b8090 JH |
187 | /* When called after waiting for received data we should be able |
188 | to tell if data we sent was accepted. */ | |
1ccd5f67 | 189 | |
ee8b8090 JH |
190 | case TFO_ATTEMPTED_DATA: |
191 | if ( getsockopt(sock, IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0 | |
192 | && tinfo.tcpi_state == TCP_ESTABLISHED | |
193 | ) | |
194 | if (tinfo.tcpi_options & TCPI_OPT_SYN_DATA) | |
195 | { | |
196 | DEBUG(D_transport|D_v) debug_printf("TFO: data was acked\n"); | |
197 | tcp_out_fastopen = TFO_USED_DATA; | |
198 | } | |
199 | else | |
1ccd5f67 JH |
200 | { |
201 | DEBUG(D_transport|D_v) debug_printf("TFO: had to retransmit\n"); | |
06e272a3 | 202 | tcp_out_fastopen = TFO_NOT_USED; |
1ccd5f67 | 203 | } |
ee8b8090 | 204 | break; |
56dbf856 JH |
205 | |
206 | default: break; /* compiler quietening */ | |
ee8b8090 | 207 | } |
1ccd5f67 JH |
208 | # endif |
209 | } | |
210 | #endif | |
211 | ||
212 | ||
0ab63f3d | 213 | /* Arguments as for smtp_connect(), plus |
b536a578 JH |
214 | early_data if non-NULL, idenmpotent data to be sent - |
215 | preferably in the TCP SYN segment | |
0ab63f3d JH |
216 | |
217 | Returns: connected socket number, or -1 with errno set | |
218 | */ | |
219 | ||
059ec3d9 | 220 | int |
7eb6c37c | 221 | smtp_sock_connect(host_item * host, int host_af, int port, uschar * interface, |
0ab63f3d | 222 | transport_instance * tb, int timeout, const blob * early_data) |
059ec3d9 | 223 | { |
7eb6c37c JH |
224 | smtp_transport_options_block * ob = |
225 | (smtp_transport_options_block *)tb->options_block; | |
226 | const uschar * dscp = ob->dscp; | |
9e4f5962 PP |
227 | int dscp_value; |
228 | int dscp_level; | |
229 | int dscp_option; | |
059ec3d9 | 230 | int sock; |
7eb6c37c | 231 | int save_errno = 0; |
10ac8d7f | 232 | const blob * fastopen_blob = NULL; |
1ccd5f67 | 233 | |
059ec3d9 | 234 | |
0cbf2b82 | 235 | #ifndef DISABLE_EVENT |
7eb6c37c JH |
236 | deliver_host_address = host->address; |
237 | deliver_host_port = port; | |
238 | if (event_raise(tb->event_action, US"tcp:connect", NULL)) return -1; | |
a7538db1 JH |
239 | #endif |
240 | ||
059ec3d9 PH |
241 | if ((sock = ip_socket(SOCK_STREAM, host_af)) < 0) return -1; |
242 | ||
243 | /* Set TCP_NODELAY; Exim does its own buffering. */ | |
244 | ||
d4ff61d1 JH |
245 | if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, US &on, sizeof(on))) |
246 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 247 | debug_printf_indent("failed to set NODELAY: %s ", strerror(errno)); |
059ec3d9 | 248 | |
9e4f5962 PP |
249 | /* Set DSCP value, if we can. For now, if we fail to set the value, we don't |
250 | bomb out, just log it and continue in default traffic class. */ | |
251 | ||
252 | if (dscp && dscp_lookup(dscp, host_af, &dscp_level, &dscp_option, &dscp_value)) | |
253 | { | |
254 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 255 | debug_printf_indent("DSCP \"%s\"=%x ", dscp, dscp_value); |
9e4f5962 PP |
256 | if (setsockopt(sock, dscp_level, dscp_option, &dscp_value, sizeof(dscp_value)) < 0) |
257 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 258 | debug_printf_indent("failed to set DSCP: %s ", strerror(errno)); |
9e4f5962 PP |
259 | /* If the kernel supports IPv4 and IPv6 on an IPv6 socket, we need to set the |
260 | option for both; ignore failures here */ | |
261 | if (host_af == AF_INET6 && | |
262 | dscp_lookup(dscp, AF_INET, &dscp_level, &dscp_option, &dscp_value)) | |
9e4f5962 | 263 | (void) setsockopt(sock, dscp_level, dscp_option, &dscp_value, sizeof(dscp_value)); |
9e4f5962 PP |
264 | } |
265 | ||
059ec3d9 PH |
266 | /* Bind to a specific interface if requested. Caller must ensure the interface |
267 | is the same type (IPv4 or IPv6) as the outgoing address. */ | |
268 | ||
7eb6c37c | 269 | if (interface && ip_bind(sock, host_af, interface, 0) < 0) |
059ec3d9 PH |
270 | { |
271 | save_errno = errno; | |
272 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 273 | debug_printf_indent("unable to bind outgoing SMTP call to %s: %s", interface, |
059ec3d9 PH |
274 | strerror(errno)); |
275 | } | |
276 | ||
277 | /* Connect to the remote host, and add keepalive to the socket before returning | |
0ab63f3d | 278 | it, if requested. If the build supports TFO, request it - and if the caller |
ee8b8090 JH |
279 | requested some early-data then include that in the TFO request. If there is |
280 | early-data but no TFO support, send it after connecting. */ | |
059ec3d9 | 281 | |
0ab63f3d JH |
282 | else |
283 | { | |
0ab63f3d | 284 | #ifdef TCP_FASTOPEN |
3fb3231c | 285 | if (verify_check_given_host(CUSS &ob->hosts_try_fastopen, host) == OK) |
10ac8d7f | 286 | fastopen_blob = early_data ? early_data : &tcp_fastopen_nodata; |
0ab63f3d JH |
287 | #endif |
288 | ||
10ac8d7f | 289 | if (ip_connect(sock, host_af, host->address, port, timeout, fastopen_blob) < 0) |
0ab63f3d | 290 | save_errno = errno; |
10ac8d7f | 291 | else if (early_data && !fastopen_blob && early_data->data && early_data->len) |
ee8b8090 JH |
292 | { |
293 | HDEBUG(D_transport|D_acl|D_v) | |
294 | debug_printf("sending %ld nonTFO early-data\n", (long)early_data->len); | |
295 | ||
296 | #ifdef TCP_QUICKACK | |
297 | (void) setsockopt(sock, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off)); | |
298 | #endif | |
0ab63f3d JH |
299 | if (send(sock, early_data->data, early_data->len, 0) < 0) |
300 | save_errno = errno; | |
ee8b8090 | 301 | } |
0ab63f3d | 302 | } |
059ec3d9 PH |
303 | |
304 | /* Either bind() or connect() failed */ | |
305 | ||
306 | if (save_errno != 0) | |
307 | { | |
8e669ac1 | 308 | HDEBUG(D_transport|D_acl|D_v) |
4deaf07d | 309 | { |
adb21834 | 310 | debug_printf_indent(" failed: %s", CUstrerror(save_errno)); |
8e669ac1 | 311 | if (save_errno == ETIMEDOUT) |
4deaf07d | 312 | debug_printf(" (timeout=%s)", readconf_printtime(timeout)); |
8e669ac1 PH |
313 | debug_printf("\n"); |
314 | } | |
f1e894f3 | 315 | (void)close(sock); |
059ec3d9 PH |
316 | errno = save_errno; |
317 | return -1; | |
318 | } | |
319 | ||
ee8b8090 | 320 | /* Both bind() and connect() succeeded, and any early-data */ |
059ec3d9 PH |
321 | |
322 | else | |
323 | { | |
41c7c167 PH |
324 | union sockaddr_46 interface_sock; |
325 | EXIM_SOCKLEN_T size = sizeof(interface_sock); | |
ee8b8090 | 326 | |
adb21834 | 327 | HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" connected\n"); |
41c7c167 PH |
328 | if (getsockname(sock, (struct sockaddr *)(&interface_sock), &size) == 0) |
329 | sending_ip_address = host_ntoa(-1, &interface_sock, NULL, &sending_port); | |
330 | else | |
331 | { | |
332 | log_write(0, LOG_MAIN | ((errno == ECONNRESET)? 0 : LOG_PANIC), | |
333 | "getsockname() failed: %s", strerror(errno)); | |
334 | close(sock); | |
335 | return -1; | |
336 | } | |
ee8b8090 | 337 | |
7eb6c37c | 338 | if (ob->keepalive) ip_keepalive(sock, host->address, TRUE); |
1ccd5f67 | 339 | #ifdef TCP_FASTOPEN |
ee8b8090 | 340 | tfo_out_check(sock); |
1ccd5f67 | 341 | #endif |
059ec3d9 PH |
342 | return sock; |
343 | } | |
344 | } | |
345 | ||
58c30e47 JH |
346 | |
347 | ||
348 | ||
349 | ||
350 | void | |
351 | smtp_port_for_connect(host_item * host, int port) | |
352 | { | |
353 | if (host->port != PORT_NONE) | |
354 | { | |
355 | HDEBUG(D_transport|D_acl|D_v) | |
356 | debug_printf_indent("Transport port=%d replaced by host-specific port=%d\n", port, | |
357 | host->port); | |
358 | port = host->port; | |
359 | } | |
360 | else host->port = port; /* Set the port actually used */ | |
361 | } | |
362 | ||
363 | ||
7eb6c37c JH |
364 | /************************************************* |
365 | * Connect to remote host * | |
366 | *************************************************/ | |
367 | ||
368 | /* Create a socket, and connect it to a remote host. IPv6 addresses are | |
369 | detected by checking for a colon in the address. AF_INET6 is defined even on | |
370 | non-IPv6 systems, to enable the code to be less messy. However, on such systems | |
371 | host->address will always be an IPv4 address. | |
372 | ||
7eb6c37c | 373 | Arguments: |
ee8b8090 JH |
374 | sc details for making connection: host, af, interface, transport |
375 | early_data if non-NULL, data to be sent - preferably in the TCP SYN segment | |
7eb6c37c JH |
376 | |
377 | Returns: connected socket number, or -1 with errno set | |
378 | */ | |
379 | ||
380 | int | |
ee8b8090 | 381 | smtp_connect(smtp_connect_args * sc, const blob * early_data) |
7eb6c37c | 382 | { |
ee8b8090 JH |
383 | int port = sc->host->port; |
384 | smtp_transport_options_block * ob = sc->ob; | |
7eb6c37c | 385 | |
ee8b8090 | 386 | callout_address = string_sprintf("[%s]:%d", sc->host->address, port); |
055e2cb4 | 387 | |
7eb6c37c JH |
388 | HDEBUG(D_transport|D_acl|D_v) |
389 | { | |
390 | uschar * s = US" "; | |
ee8b8090 | 391 | if (sc->interface) s = string_sprintf(" from %s ", sc->interface); |
f0989ec0 | 392 | #ifdef SUPPORT_SOCKS |
7eb6c37c JH |
393 | if (ob->socks_proxy) s = string_sprintf("%svia proxy ", s); |
394 | #endif | |
ee8b8090 | 395 | debug_printf_indent("Connecting to %s %s%s... ", sc->host->name, callout_address, s); |
7eb6c37c JH |
396 | } |
397 | ||
398 | /* Create and connect the socket */ | |
399 | ||
f0989ec0 | 400 | #ifdef SUPPORT_SOCKS |
7eb6c37c | 401 | if (ob->socks_proxy) |
ee8b8090 JH |
402 | { |
403 | int sock = socks_sock_connect(sc->host, sc->host_af, port, sc->interface, | |
404 | sc->tblock, ob->connect_timeout); | |
405 | ||
406 | if (sock >= 0) | |
407 | { | |
408 | if (early_data && early_data->data && early_data->len) | |
409 | if (send(sock, early_data->data, early_data->len, 0) < 0) | |
410 | { | |
411 | int save_errno = errno; | |
412 | HDEBUG(D_transport|D_acl|D_v) | |
413 | { | |
414 | debug_printf_indent("failed: %s", CUstrerror(save_errno)); | |
415 | if (save_errno == ETIMEDOUT) | |
416 | debug_printf(" (timeout=%s)", readconf_printtime(ob->connect_timeout)); | |
417 | debug_printf("\n"); | |
418 | } | |
419 | (void)close(sock); | |
420 | sock = -1; | |
421 | errno = save_errno; | |
422 | } | |
423 | } | |
424 | return sock; | |
425 | } | |
7eb6c37c JH |
426 | #endif |
427 | ||
ee8b8090 JH |
428 | return smtp_sock_connect(sc->host, sc->host_af, port, sc->interface, |
429 | sc->tblock, ob->connect_timeout, early_data); | |
7eb6c37c JH |
430 | } |
431 | ||
059ec3d9 PH |
432 | |
433 | /************************************************* | |
434 | * Flush outgoing command buffer * | |
435 | *************************************************/ | |
436 | ||
437 | /* This function is called only from smtp_write_command() below. It flushes | |
438 | the buffer of outgoing commands. There is more than one in the buffer only when | |
439 | pipelining. | |
440 | ||
441 | Argument: | |
442 | outblock the SMTP output block | |
925ac8e4 | 443 | mode further data expected, or plain |
059ec3d9 PH |
444 | |
445 | Returns: TRUE if OK, FALSE on error, with errno set | |
446 | */ | |
447 | ||
448 | static BOOL | |
4e910c01 | 449 | flush_buffer(smtp_outblock * outblock, int mode) |
059ec3d9 PH |
450 | { |
451 | int rc; | |
58fc5fb2 | 452 | int n = outblock->ptr - outblock->buffer; |
925ac8e4 | 453 | BOOL more = mode == SCMD_MORE; |
059ec3d9 | 454 | |
4e910c01 | 455 | HDEBUG(D_transport|D_acl) debug_printf_indent("cmd buf flush %d bytes%s\n", n, |
925ac8e4 | 456 | more ? " (more expected)" : ""); |
4e910c01 | 457 | |
01603eec | 458 | #ifndef DISABLE_TLS |
74f1a423 JH |
459 | if (outblock->cctx->tls_ctx) |
460 | rc = tls_write(outblock->cctx->tls_ctx, outblock->buffer, n, more); | |
059ec3d9 PH |
461 | else |
462 | #endif | |
ee8b8090 JH |
463 | |
464 | { | |
465 | if (outblock->conn_args) | |
466 | { | |
467 | blob early_data = { .data = outblock->buffer, .len = n }; | |
468 | ||
469 | /* We ignore the more-flag if we're doing a connect with early-data, which | |
470 | means we won't get BDAT+data. A pity, but wise due to the idempotency | |
471 | requirement: TFO with data can, in rare cases, replay the data to the | |
472 | receiver. */ | |
473 | ||
474 | if ( (outblock->cctx->sock = smtp_connect(outblock->conn_args, &early_data)) | |
475 | < 0) | |
476 | return FALSE; | |
477 | outblock->conn_args = NULL; | |
478 | rc = n; | |
479 | } | |
480 | else | |
481 | ||
482 | rc = send(outblock->cctx->sock, outblock->buffer, n, | |
4e910c01 | 483 | #ifdef MSG_MORE |
ee8b8090 | 484 | more ? MSG_MORE : 0 |
4e910c01 | 485 | #else |
ee8b8090 | 486 | 0 |
4e910c01 | 487 | #endif |
ee8b8090 JH |
488 | ); |
489 | } | |
059ec3d9 | 490 | |
059ec3d9 PH |
491 | if (rc <= 0) |
492 | { | |
e1d04f48 | 493 | HDEBUG(D_transport|D_acl) debug_printf_indent("send failed: %s\n", strerror(errno)); |
059ec3d9 PH |
494 | return FALSE; |
495 | } | |
496 | ||
497 | outblock->ptr = outblock->buffer; | |
498 | outblock->cmd_count = 0; | |
499 | return TRUE; | |
500 | } | |
501 | ||
502 | ||
503 | ||
504 | /************************************************* | |
505 | * Write SMTP command * | |
506 | *************************************************/ | |
507 | ||
508 | /* The formatted command is left in big_buffer so that it can be reflected in | |
509 | any error message. | |
510 | ||
511 | Arguments: | |
251b9eb4 | 512 | sx SMTP connection, contains buffer for pipelining, and socket |
4e910c01 | 513 | mode buffer, write-with-more-likely, write |
059ec3d9 PH |
514 | format a format, starting with one of |
515 | of HELO, MAIL FROM, RCPT TO, DATA, ".", or QUIT. | |
6d5c916c | 516 | If NULL, flush pipeline buffer only. |
059ec3d9 PH |
517 | ... data for the format |
518 | ||
519 | Returns: 0 if command added to pipelining buffer, with nothing transmitted | |
520 | +n if n commands transmitted (may still have buffered the new one) | |
521 | -1 on error, with errno set | |
522 | */ | |
523 | ||
524 | int | |
251b9eb4 | 525 | smtp_write_command(void * sx, int mode, const char *format, ...) |
059ec3d9 | 526 | { |
251b9eb4 | 527 | smtp_outblock * outblock = &((smtp_context *)sx)->outblock; |
059ec3d9 | 528 | int rc = 0; |
059ec3d9 | 529 | |
6d5c916c | 530 | if (format) |
059ec3d9 | 531 | { |
d12746bc JH |
532 | gstring gs = { .size = big_buffer_size, .ptr = 0, .s = big_buffer }; |
533 | va_list ap; | |
534 | ||
f3ebb786 JH |
535 | /* Use taint-unchecked routines for writing into big_buffer, trusting that |
536 | we'll never expand the results. Actually, the error-message use - leaving | |
537 | the results in big_buffer for potential later use - is uncomfortably distant. | |
538 | XXX Would be better to assume all smtp commands are short, use normal pool | |
539 | alloc rather than big_buffer, and another global for the data-for-error. */ | |
540 | ||
6d5c916c | 541 | va_start(ap, format); |
f3ebb786 | 542 | if (!string_vformat(&gs, SVFMT_TAINT_NOCHK, CS format, ap)) |
6d5c916c JH |
543 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong write_command in outgoing " |
544 | "SMTP"); | |
545 | va_end(ap); | |
d12746bc | 546 | string_from_gstring(&gs); |
6d5c916c | 547 | |
d12746bc | 548 | if (gs.ptr > outblock->buffersize) |
6d5c916c JH |
549 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong write_command in outgoing " |
550 | "SMTP"); | |
551 | ||
d12746bc | 552 | if (gs.ptr > outblock->buffersize - (outblock->ptr - outblock->buffer)) |
6d5c916c JH |
553 | { |
554 | rc = outblock->cmd_count; /* flush resets */ | |
4e910c01 | 555 | if (!flush_buffer(outblock, SCMD_FLUSH)) return -1; |
6d5c916c | 556 | } |
059ec3d9 | 557 | |
f3ebb786 | 558 | Ustrncpy(outblock->ptr, gs.s, gs.ptr); |
d12746bc | 559 | outblock->ptr += gs.ptr; |
6d5c916c | 560 | outblock->cmd_count++; |
d12746bc | 561 | gs.ptr -= 2; string_from_gstring(&gs); /* remove \r\n for error message */ |
059ec3d9 | 562 | |
6d5c916c JH |
563 | /* We want to hide the actual data sent in AUTH transactions from reflections |
564 | and logs. While authenticating, a flag is set in the outblock to enable this. | |
565 | The AUTH command itself gets any data flattened. Other lines are flattened | |
566 | completely. */ | |
059ec3d9 | 567 | |
6d5c916c | 568 | if (outblock->authenticating) |
059ec3d9 | 569 | { |
6d5c916c JH |
570 | uschar *p = big_buffer; |
571 | if (Ustrncmp(big_buffer, "AUTH ", 5) == 0) | |
572 | { | |
573 | p += 5; | |
574 | while (isspace(*p)) p++; | |
575 | while (!isspace(*p)) p++; | |
576 | while (isspace(*p)) p++; | |
577 | } | |
578 | while (*p != 0) *p++ = '*'; | |
059ec3d9 | 579 | } |
059ec3d9 | 580 | |
e1d04f48 | 581 | HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> %s\n", big_buffer); |
6d5c916c | 582 | } |
059ec3d9 | 583 | |
4e910c01 | 584 | if (mode != SCMD_BUFFER) |
059ec3d9 PH |
585 | { |
586 | rc += outblock->cmd_count; /* flush resets */ | |
4e910c01 | 587 | if (!flush_buffer(outblock, mode)) return -1; |
059ec3d9 PH |
588 | } |
589 | ||
590 | return rc; | |
591 | } | |
592 | ||
593 | ||
594 | ||
595 | /************************************************* | |
596 | * Read one line of SMTP response * | |
597 | *************************************************/ | |
598 | ||
599 | /* This function reads one line of SMTP response from the server host. This may | |
600 | not be a complete response - it could be just part of a multiline response. We | |
601 | have to use a buffer for incoming packets, because when pipelining or using | |
602 | LMTP, there may well be more than one response in a single packet. This | |
603 | function is called only from the one that follows. | |
604 | ||
605 | Arguments: | |
606 | inblock the SMTP input block (contains holding buffer, socket, etc.) | |
607 | buffer where to put the line | |
608 | size space available for the line | |
0a5441fc | 609 | timelimit deadline for reading the lime, seconds past epoch |
059ec3d9 PH |
610 | |
611 | Returns: length of a line that has been put in the buffer | |
612 | -1 otherwise, with errno set | |
613 | */ | |
614 | ||
615 | static int | |
0a5441fc | 616 | read_response_line(smtp_inblock *inblock, uschar *buffer, int size, time_t timelimit) |
059ec3d9 PH |
617 | { |
618 | uschar *p = buffer; | |
619 | uschar *ptr = inblock->ptr; | |
620 | uschar *ptrend = inblock->ptrend; | |
74f1a423 | 621 | client_conn_ctx * cctx = inblock->cctx; |
059ec3d9 PH |
622 | |
623 | /* Loop for reading multiple packets or reading another packet after emptying | |
624 | a previously-read one. */ | |
625 | ||
626 | for (;;) | |
627 | { | |
628 | int rc; | |
629 | ||
630 | /* If there is data in the input buffer left over from last time, copy | |
631 | characters from it until the end of a line, at which point we can return, | |
632 | having removed any whitespace (which will include CR) at the end of the line. | |
633 | The rules for SMTP say that lines end in CRLF, but there are have been cases | |
634 | of hosts using just LF, and other MTAs are reported to handle this, so we | |
635 | just look for LF. If we run out of characters before the end of a line, | |
636 | carry on to read the next incoming packet. */ | |
637 | ||
638 | while (ptr < ptrend) | |
639 | { | |
640 | int c = *ptr++; | |
641 | if (c == '\n') | |
642 | { | |
643 | while (p > buffer && isspace(p[-1])) p--; | |
644 | *p = 0; | |
645 | inblock->ptr = ptr; | |
646 | return p - buffer; | |
647 | } | |
648 | *p++ = c; | |
649 | if (--size < 4) | |
650 | { | |
651 | *p = 0; /* Leave malformed line for error message */ | |
652 | errno = ERRNO_SMTPFORMAT; | |
653 | return -1; | |
654 | } | |
655 | } | |
656 | ||
657 | /* Need to read a new input packet. */ | |
658 | ||
0a5441fc | 659 | if((rc = ip_recv(cctx, inblock->buffer, inblock->buffersize, timelimit)) <= 0) |
de6273b4 | 660 | { |
eebcfa1c | 661 | DEBUG(D_deliver|D_transport|D_acl|D_v) |
170f4904 JH |
662 | debug_printf_indent(errno ? " SMTP(%s)<<\n" : " SMTP(closed)<<\n", |
663 | strerror(errno)); | |
de6273b4 JH |
664 | break; |
665 | } | |
059ec3d9 PH |
666 | |
667 | /* Another block of data has been successfully read. Set up the pointers | |
668 | and let the loop continue. */ | |
669 | ||
670 | ptrend = inblock->ptrend = inblock->buffer + rc; | |
671 | ptr = inblock->buffer; | |
e1d04f48 | 672 | DEBUG(D_transport|D_acl) debug_printf_indent("read response data: size=%d\n", rc); |
059ec3d9 PH |
673 | } |
674 | ||
675 | /* Get here if there has been some kind of recv() error; errno is set, but we | |
676 | ensure that the result buffer is empty before returning. */ | |
677 | ||
678 | *buffer = 0; | |
679 | return -1; | |
680 | } | |
681 | ||
682 | ||
683 | ||
684 | ||
685 | ||
686 | /************************************************* | |
687 | * Read SMTP response * | |
688 | *************************************************/ | |
689 | ||
690 | /* This function reads an SMTP response with a timeout, and returns the | |
691 | response in the given buffer, as a string. A multiline response will contain | |
692 | newline characters between the lines. The function also analyzes the first | |
693 | digit of the reply code and returns FALSE if it is not acceptable. FALSE is | |
694 | also returned after a reading error. In this case buffer[0] will be zero, and | |
695 | the error code will be in errno. | |
696 | ||
697 | Arguments: | |
251b9eb4 JH |
698 | sx the SMTP connection (contains input block with holding buffer, |
699 | socket, etc.) | |
059ec3d9 PH |
700 | buffer where to put the response |
701 | size the size of the buffer | |
702 | okdigit the expected first digit of the response | |
2760b518 | 703 | timeout the timeout to use, in seconds |
059ec3d9 PH |
704 | |
705 | Returns: TRUE if a valid, non-error response was received; else FALSE | |
706 | */ | |
ee8b8090 | 707 | /*XXX could move to smtp transport; no other users */ |
059ec3d9 PH |
708 | |
709 | BOOL | |
fc243e94 | 710 | smtp_read_response(void * sx0, uschar * buffer, int size, int okdigit, |
059ec3d9 PH |
711 | int timeout) |
712 | { | |
ee8b8090 | 713 | smtp_context * sx = sx0; |
fc243e94 | 714 | uschar * ptr = buffer; |
dca6d121 | 715 | int count = 0; |
0a5441fc | 716 | time_t timelimit = time(NULL) + timeout; |
059ec3d9 PH |
717 | |
718 | errno = 0; /* Ensure errno starts out zero */ | |
719 | ||
4e48d56c | 720 | #ifdef SUPPORT_PIPE_CONNECT |
ee8b8090 | 721 | if (sx->pending_BANNER || sx->pending_EHLO) |
dca6d121 JH |
722 | { |
723 | int rc; | |
fc243e94 | 724 | if ((rc = smtp_reap_early_pipe(sx, &count)) != OK) |
ee8b8090 JH |
725 | { |
726 | DEBUG(D_transport) debug_printf("failed reaping pipelined cmd responsess\n"); | |
fc243e94 JH |
727 | buffer[0] = '\0'; |
728 | if (rc == DEFER) errno = ERRNO_TLSFAILURE; | |
ee8b8090 JH |
729 | return FALSE; |
730 | } | |
dca6d121 | 731 | } |
ee8b8090 JH |
732 | #endif |
733 | ||
4c04137d | 734 | /* This is a loop to read and concatenate the lines that make up a multi-line |
059ec3d9 PH |
735 | response. */ |
736 | ||
737 | for (;;) | |
738 | { | |
0a5441fc | 739 | if ((count = read_response_line(&sx->inblock, ptr, size, timelimit)) < 0) |
059ec3d9 PH |
740 | return FALSE; |
741 | ||
742 | HDEBUG(D_transport|D_acl|D_v) | |
ee8b8090 | 743 | debug_printf_indent(" %s %s\n", ptr == buffer ? "SMTP<<" : " ", ptr); |
059ec3d9 PH |
744 | |
745 | /* Check the format of the response: it must start with three digits; if | |
746 | these are followed by a space or end of line, the response is complete. If | |
747 | they are followed by '-' this is a multi-line response and we must look for | |
748 | another line until the final line is reached. The only use made of multi-line | |
749 | responses is to pass them back as error messages. We therefore just | |
750 | concatenate them all within the buffer, which should be large enough to | |
751 | accept any reasonable number of lines. */ | |
752 | ||
753 | if (count < 3 || | |
754 | !isdigit(ptr[0]) || | |
755 | !isdigit(ptr[1]) || | |
756 | !isdigit(ptr[2]) || | |
757 | (ptr[3] != '-' && ptr[3] != ' ' && ptr[3] != 0)) | |
758 | { | |
759 | errno = ERRNO_SMTPFORMAT; /* format error */ | |
760 | return FALSE; | |
761 | } | |
762 | ||
763 | /* If the line we have just read is a terminal line, line, we are done. | |
764 | Otherwise more data has to be read. */ | |
765 | ||
766 | if (ptr[3] != '-') break; | |
767 | ||
768 | /* Move the reading pointer upwards in the buffer and insert \n between the | |
769 | components of a multiline response. Space is left for this by read_response_ | |
770 | line(). */ | |
771 | ||
772 | ptr += count; | |
773 | *ptr++ = '\n'; | |
774 | size -= count + 1; | |
775 | } | |
776 | ||
ee8b8090 JH |
777 | #ifdef TCP_FASTOPEN |
778 | tfo_out_check(sx->cctx.sock); | |
779 | #endif | |
780 | ||
059ec3d9 PH |
781 | /* Return a value that depends on the SMTP return code. On some systems a |
782 | non-zero value of errno has been seen at this point, so ensure it is zero, | |
783 | because the caller of this function looks at errno when FALSE is returned, to | |
784 | distinguish between an unexpected return code and other errors such as | |
785 | timeouts, lost connections, etc. */ | |
786 | ||
787 | errno = 0; | |
788 | return buffer[0] == okdigit; | |
789 | } | |
790 | ||
791 | /* End of smtp_out.c */ | |
7eb6c37c JH |
792 | /* vi: aw ai sw=2 |
793 | */ |