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 | ||
059ec3d9 PH |
55 | while (isspace(*expint)) expint++; |
56 | if (*expint == 0) return TRUE; | |
57 | ||
58 | while ((iface = string_nextinlist(&expint, &sep, big_buffer, | |
fb05276a | 59 | big_buffer_size))) |
059ec3d9 PH |
60 | { |
61 | if (string_is_ip_address(iface, NULL) == 0) | |
62 | { | |
63 | addr->transport_return = PANIC; | |
64 | addr->message = string_sprintf("\"%s\" is not a valid IP " | |
65 | "address for the \"interface\" option for %s", | |
66 | iface, msg); | |
67 | return FALSE; | |
68 | } | |
69 | ||
70 | if (((Ustrchr(iface, ':') == NULL)? AF_INET:AF_INET6) == host_af) | |
71 | break; | |
72 | } | |
73 | ||
fb05276a | 74 | if (iface) *interface = string_copy(iface); |
059ec3d9 PH |
75 | return TRUE; |
76 | } | |
77 | ||
78 | ||
79 | ||
80 | /************************************************* | |
81 | * Find an outgoing port * | |
82 | *************************************************/ | |
83 | ||
84 | /* This function is called from the smtp transport and also from the callout | |
85 | code in verify.c. Its job is to find a port number. Note that getservbyname() | |
86 | produces the number in network byte order. | |
87 | ||
88 | Arguments: | |
89 | rstring raw (unexpanded) string representation of the port | |
90 | addr the mail address being handled (for setting errors) | |
91 | port stick the port in here | |
92 | msg for adding to error message | |
93 | ||
94 | Returns: TRUE on success, FALSE on failure, with error message set | |
95 | in addr, and transport_return set to PANIC | |
96 | */ | |
97 | ||
98 | BOOL | |
99 | smtp_get_port(uschar *rstring, address_item *addr, int *port, uschar *msg) | |
100 | { | |
101 | uschar *pstring = expand_string(rstring); | |
102 | ||
00580051 | 103 | if (!pstring) |
059ec3d9 PH |
104 | { |
105 | addr->transport_return = PANIC; | |
106 | addr->message = string_sprintf("failed to expand \"%s\" (\"port\" option) " | |
107 | "for %s: %s", rstring, msg, expand_string_message); | |
108 | return FALSE; | |
109 | } | |
110 | ||
111 | if (isdigit(*pstring)) | |
112 | { | |
113 | uschar *end; | |
114 | *port = Ustrtol(pstring, &end, 0); | |
115 | if (end != pstring + Ustrlen(pstring)) | |
116 | { | |
117 | addr->transport_return = PANIC; | |
118 | addr->message = string_sprintf("invalid port number for %s: %s", msg, | |
119 | pstring); | |
120 | return FALSE; | |
121 | } | |
122 | } | |
123 | ||
124 | else | |
125 | { | |
126 | struct servent *smtp_service = getservbyname(CS pstring, "tcp"); | |
00580051 | 127 | if (!smtp_service) |
059ec3d9 PH |
128 | { |
129 | addr->transport_return = PANIC; | |
130 | addr->message = string_sprintf("TCP port \"%s\" is not defined for %s", | |
131 | pstring, msg); | |
132 | return FALSE; | |
133 | } | |
134 | *port = ntohs(smtp_service->s_port); | |
135 | } | |
136 | ||
137 | return TRUE; | |
138 | } | |
139 | ||
140 | ||
141 | ||
142 | ||
1ccd5f67 JH |
143 | #ifdef TCP_FASTOPEN |
144 | static void | |
145 | tfo_out_check(int sock) | |
146 | { | |
147 | # if defined(TCP_INFO) && defined(EXIM_HAVE_TCPI_UNACKED) | |
148 | struct tcp_info tinfo; | |
149 | socklen_t len = sizeof(tinfo); | |
150 | ||
ee8b8090 JH |
151 | switch (tcp_out_fastopen) |
152 | { | |
153 | /* This is a somewhat dubious detection method; totally undocumented so likely | |
154 | to fail in future kernels. There seems to be no documented way. What we really | |
155 | want to know is if the server sent smtp-banner data before our ACK of his SYN,ACK | |
156 | hit him. What this (possibly?) detects is whether we sent a TFO cookie with our | |
157 | SYN, as distinct from a TFO request. This gets a false-positive when the server | |
158 | key is rotated; we send the old one (which this test sees) but the server returns | |
159 | the new one and does not send its SMTP banner before we ACK his SYN,ACK. | |
160 | To force that rotation case: | |
161 | '# echo -n "00000000-00000000-00000000-0000000" >/proc/sys/net/ipv4/tcp_fastopen_key' | |
162 | The kernel seems to be counting unack'd packets. */ | |
163 | ||
164 | case TFO_ATTEMPTED_NODATA: | |
165 | if ( getsockopt(sock, IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0 | |
166 | && tinfo.tcpi_state == TCP_SYN_SENT | |
167 | && tinfo.tcpi_unacked > 1 | |
168 | ) | |
169 | { | |
170 | DEBUG(D_transport|D_v) | |
171 | debug_printf("TCP_FASTOPEN tcpi_unacked %d\n", tinfo.tcpi_unacked); | |
172 | tcp_out_fastopen = TFO_USED_NODATA; | |
173 | } | |
174 | break; | |
1ccd5f67 | 175 | |
ee8b8090 JH |
176 | /* When called after waiting for received data we should be able |
177 | to tell if data we sent was accepted. */ | |
1ccd5f67 | 178 | |
ee8b8090 JH |
179 | case TFO_ATTEMPTED_DATA: |
180 | if ( getsockopt(sock, IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0 | |
181 | && tinfo.tcpi_state == TCP_ESTABLISHED | |
182 | ) | |
183 | if (tinfo.tcpi_options & TCPI_OPT_SYN_DATA) | |
184 | { | |
185 | DEBUG(D_transport|D_v) debug_printf("TFO: data was acked\n"); | |
186 | tcp_out_fastopen = TFO_USED_DATA; | |
187 | } | |
188 | else | |
1ccd5f67 JH |
189 | { |
190 | DEBUG(D_transport|D_v) debug_printf("TFO: had to retransmit\n"); | |
06e272a3 | 191 | tcp_out_fastopen = TFO_NOT_USED; |
1ccd5f67 | 192 | } |
ee8b8090 | 193 | break; |
56dbf856 JH |
194 | |
195 | default: break; /* compiler quietening */ | |
ee8b8090 | 196 | } |
1ccd5f67 JH |
197 | # endif |
198 | } | |
199 | #endif | |
200 | ||
201 | ||
0ab63f3d | 202 | /* Arguments as for smtp_connect(), plus |
b536a578 JH |
203 | early_data if non-NULL, idenmpotent data to be sent - |
204 | preferably in the TCP SYN segment | |
0ab63f3d JH |
205 | |
206 | Returns: connected socket number, or -1 with errno set | |
207 | */ | |
208 | ||
059ec3d9 | 209 | int |
7eb6c37c | 210 | smtp_sock_connect(host_item * host, int host_af, int port, uschar * interface, |
0ab63f3d | 211 | transport_instance * tb, int timeout, const blob * early_data) |
059ec3d9 | 212 | { |
7eb6c37c JH |
213 | smtp_transport_options_block * ob = |
214 | (smtp_transport_options_block *)tb->options_block; | |
215 | const uschar * dscp = ob->dscp; | |
9e4f5962 PP |
216 | int dscp_value; |
217 | int dscp_level; | |
218 | int dscp_option; | |
059ec3d9 | 219 | int sock; |
7eb6c37c | 220 | int save_errno = 0; |
10ac8d7f | 221 | const blob * fastopen_blob = NULL; |
1ccd5f67 | 222 | |
059ec3d9 | 223 | |
0cbf2b82 | 224 | #ifndef DISABLE_EVENT |
7eb6c37c JH |
225 | deliver_host_address = host->address; |
226 | deliver_host_port = port; | |
227 | if (event_raise(tb->event_action, US"tcp:connect", NULL)) return -1; | |
a7538db1 JH |
228 | #endif |
229 | ||
059ec3d9 PH |
230 | if ((sock = ip_socket(SOCK_STREAM, host_af)) < 0) return -1; |
231 | ||
232 | /* Set TCP_NODELAY; Exim does its own buffering. */ | |
233 | ||
d4ff61d1 JH |
234 | if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, US &on, sizeof(on))) |
235 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 236 | debug_printf_indent("failed to set NODELAY: %s ", strerror(errno)); |
059ec3d9 | 237 | |
9e4f5962 PP |
238 | /* Set DSCP value, if we can. For now, if we fail to set the value, we don't |
239 | bomb out, just log it and continue in default traffic class. */ | |
240 | ||
241 | if (dscp && dscp_lookup(dscp, host_af, &dscp_level, &dscp_option, &dscp_value)) | |
242 | { | |
243 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 244 | debug_printf_indent("DSCP \"%s\"=%x ", dscp, dscp_value); |
9e4f5962 PP |
245 | if (setsockopt(sock, dscp_level, dscp_option, &dscp_value, sizeof(dscp_value)) < 0) |
246 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 247 | debug_printf_indent("failed to set DSCP: %s ", strerror(errno)); |
9e4f5962 PP |
248 | /* If the kernel supports IPv4 and IPv6 on an IPv6 socket, we need to set the |
249 | option for both; ignore failures here */ | |
250 | if (host_af == AF_INET6 && | |
251 | dscp_lookup(dscp, AF_INET, &dscp_level, &dscp_option, &dscp_value)) | |
9e4f5962 | 252 | (void) setsockopt(sock, dscp_level, dscp_option, &dscp_value, sizeof(dscp_value)); |
9e4f5962 PP |
253 | } |
254 | ||
059ec3d9 PH |
255 | /* Bind to a specific interface if requested. Caller must ensure the interface |
256 | is the same type (IPv4 or IPv6) as the outgoing address. */ | |
257 | ||
7eb6c37c | 258 | if (interface && ip_bind(sock, host_af, interface, 0) < 0) |
059ec3d9 PH |
259 | { |
260 | save_errno = errno; | |
261 | HDEBUG(D_transport|D_acl|D_v) | |
e1d04f48 | 262 | debug_printf_indent("unable to bind outgoing SMTP call to %s: %s", interface, |
059ec3d9 PH |
263 | strerror(errno)); |
264 | } | |
265 | ||
266 | /* Connect to the remote host, and add keepalive to the socket before returning | |
0ab63f3d | 267 | it, if requested. If the build supports TFO, request it - and if the caller |
ee8b8090 JH |
268 | requested some early-data then include that in the TFO request. If there is |
269 | early-data but no TFO support, send it after connecting. */ | |
059ec3d9 | 270 | |
0ab63f3d JH |
271 | else |
272 | { | |
0ab63f3d | 273 | #ifdef TCP_FASTOPEN |
3fb3231c | 274 | if (verify_check_given_host(CUSS &ob->hosts_try_fastopen, host) == OK) |
10ac8d7f | 275 | fastopen_blob = early_data ? early_data : &tcp_fastopen_nodata; |
0ab63f3d JH |
276 | #endif |
277 | ||
10ac8d7f | 278 | if (ip_connect(sock, host_af, host->address, port, timeout, fastopen_blob) < 0) |
0ab63f3d | 279 | save_errno = errno; |
10ac8d7f | 280 | else if (early_data && !fastopen_blob && early_data->data && early_data->len) |
ee8b8090 JH |
281 | { |
282 | HDEBUG(D_transport|D_acl|D_v) | |
283 | debug_printf("sending %ld nonTFO early-data\n", (long)early_data->len); | |
284 | ||
285 | #ifdef TCP_QUICKACK | |
286 | (void) setsockopt(sock, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off)); | |
287 | #endif | |
0ab63f3d JH |
288 | if (send(sock, early_data->data, early_data->len, 0) < 0) |
289 | save_errno = errno; | |
ee8b8090 | 290 | } |
0ab63f3d | 291 | } |
059ec3d9 PH |
292 | |
293 | /* Either bind() or connect() failed */ | |
294 | ||
295 | if (save_errno != 0) | |
296 | { | |
8e669ac1 | 297 | HDEBUG(D_transport|D_acl|D_v) |
4deaf07d | 298 | { |
e1d04f48 | 299 | debug_printf_indent("failed: %s", CUstrerror(save_errno)); |
8e669ac1 | 300 | if (save_errno == ETIMEDOUT) |
4deaf07d | 301 | debug_printf(" (timeout=%s)", readconf_printtime(timeout)); |
8e669ac1 PH |
302 | debug_printf("\n"); |
303 | } | |
f1e894f3 | 304 | (void)close(sock); |
059ec3d9 PH |
305 | errno = save_errno; |
306 | return -1; | |
307 | } | |
308 | ||
ee8b8090 | 309 | /* Both bind() and connect() succeeded, and any early-data */ |
059ec3d9 PH |
310 | |
311 | else | |
312 | { | |
41c7c167 PH |
313 | union sockaddr_46 interface_sock; |
314 | EXIM_SOCKLEN_T size = sizeof(interface_sock); | |
ee8b8090 | 315 | |
e1d04f48 | 316 | HDEBUG(D_transport|D_acl|D_v) debug_printf_indent("connected\n"); |
41c7c167 PH |
317 | if (getsockname(sock, (struct sockaddr *)(&interface_sock), &size) == 0) |
318 | sending_ip_address = host_ntoa(-1, &interface_sock, NULL, &sending_port); | |
319 | else | |
320 | { | |
321 | log_write(0, LOG_MAIN | ((errno == ECONNRESET)? 0 : LOG_PANIC), | |
322 | "getsockname() failed: %s", strerror(errno)); | |
323 | close(sock); | |
324 | return -1; | |
325 | } | |
ee8b8090 | 326 | |
7eb6c37c | 327 | if (ob->keepalive) ip_keepalive(sock, host->address, TRUE); |
1ccd5f67 | 328 | #ifdef TCP_FASTOPEN |
ee8b8090 | 329 | tfo_out_check(sock); |
1ccd5f67 | 330 | #endif |
059ec3d9 PH |
331 | return sock; |
332 | } | |
333 | } | |
334 | ||
58c30e47 JH |
335 | |
336 | ||
337 | ||
338 | ||
339 | void | |
340 | smtp_port_for_connect(host_item * host, int port) | |
341 | { | |
342 | if (host->port != PORT_NONE) | |
343 | { | |
344 | HDEBUG(D_transport|D_acl|D_v) | |
345 | debug_printf_indent("Transport port=%d replaced by host-specific port=%d\n", port, | |
346 | host->port); | |
347 | port = host->port; | |
348 | } | |
349 | else host->port = port; /* Set the port actually used */ | |
350 | } | |
351 | ||
352 | ||
7eb6c37c JH |
353 | /************************************************* |
354 | * Connect to remote host * | |
355 | *************************************************/ | |
356 | ||
357 | /* Create a socket, and connect it to a remote host. IPv6 addresses are | |
358 | detected by checking for a colon in the address. AF_INET6 is defined even on | |
359 | non-IPv6 systems, to enable the code to be less messy. However, on such systems | |
360 | host->address will always be an IPv4 address. | |
361 | ||
7eb6c37c | 362 | Arguments: |
ee8b8090 JH |
363 | sc details for making connection: host, af, interface, transport |
364 | early_data if non-NULL, data to be sent - preferably in the TCP SYN segment | |
7eb6c37c JH |
365 | |
366 | Returns: connected socket number, or -1 with errno set | |
367 | */ | |
368 | ||
369 | int | |
ee8b8090 | 370 | smtp_connect(smtp_connect_args * sc, const blob * early_data) |
7eb6c37c | 371 | { |
ee8b8090 JH |
372 | int port = sc->host->port; |
373 | smtp_transport_options_block * ob = sc->ob; | |
7eb6c37c | 374 | |
ee8b8090 | 375 | callout_address = string_sprintf("[%s]:%d", sc->host->address, port); |
055e2cb4 | 376 | |
7eb6c37c JH |
377 | HDEBUG(D_transport|D_acl|D_v) |
378 | { | |
379 | uschar * s = US" "; | |
ee8b8090 | 380 | if (sc->interface) s = string_sprintf(" from %s ", sc->interface); |
f0989ec0 | 381 | #ifdef SUPPORT_SOCKS |
7eb6c37c JH |
382 | if (ob->socks_proxy) s = string_sprintf("%svia proxy ", s); |
383 | #endif | |
ee8b8090 | 384 | debug_printf_indent("Connecting to %s %s%s... ", sc->host->name, callout_address, s); |
7eb6c37c JH |
385 | } |
386 | ||
387 | /* Create and connect the socket */ | |
388 | ||
f0989ec0 | 389 | #ifdef SUPPORT_SOCKS |
7eb6c37c | 390 | if (ob->socks_proxy) |
ee8b8090 JH |
391 | { |
392 | int sock = socks_sock_connect(sc->host, sc->host_af, port, sc->interface, | |
393 | sc->tblock, ob->connect_timeout); | |
394 | ||
395 | if (sock >= 0) | |
396 | { | |
397 | if (early_data && early_data->data && early_data->len) | |
398 | if (send(sock, early_data->data, early_data->len, 0) < 0) | |
399 | { | |
400 | int save_errno = errno; | |
401 | HDEBUG(D_transport|D_acl|D_v) | |
402 | { | |
403 | debug_printf_indent("failed: %s", CUstrerror(save_errno)); | |
404 | if (save_errno == ETIMEDOUT) | |
405 | debug_printf(" (timeout=%s)", readconf_printtime(ob->connect_timeout)); | |
406 | debug_printf("\n"); | |
407 | } | |
408 | (void)close(sock); | |
409 | sock = -1; | |
410 | errno = save_errno; | |
411 | } | |
412 | } | |
413 | return sock; | |
414 | } | |
7eb6c37c JH |
415 | #endif |
416 | ||
ee8b8090 JH |
417 | return smtp_sock_connect(sc->host, sc->host_af, port, sc->interface, |
418 | sc->tblock, ob->connect_timeout, early_data); | |
7eb6c37c JH |
419 | } |
420 | ||
059ec3d9 PH |
421 | |
422 | /************************************************* | |
423 | * Flush outgoing command buffer * | |
424 | *************************************************/ | |
425 | ||
426 | /* This function is called only from smtp_write_command() below. It flushes | |
427 | the buffer of outgoing commands. There is more than one in the buffer only when | |
428 | pipelining. | |
429 | ||
430 | Argument: | |
431 | outblock the SMTP output block | |
925ac8e4 | 432 | mode further data expected, or plain |
059ec3d9 PH |
433 | |
434 | Returns: TRUE if OK, FALSE on error, with errno set | |
435 | */ | |
436 | ||
437 | static BOOL | |
4e910c01 | 438 | flush_buffer(smtp_outblock * outblock, int mode) |
059ec3d9 PH |
439 | { |
440 | int rc; | |
58fc5fb2 | 441 | int n = outblock->ptr - outblock->buffer; |
925ac8e4 | 442 | BOOL more = mode == SCMD_MORE; |
059ec3d9 | 443 | |
4e910c01 | 444 | HDEBUG(D_transport|D_acl) debug_printf_indent("cmd buf flush %d bytes%s\n", n, |
925ac8e4 | 445 | more ? " (more expected)" : ""); |
4e910c01 | 446 | |
01603eec | 447 | #ifndef DISABLE_TLS |
74f1a423 JH |
448 | if (outblock->cctx->tls_ctx) |
449 | rc = tls_write(outblock->cctx->tls_ctx, outblock->buffer, n, more); | |
059ec3d9 PH |
450 | else |
451 | #endif | |
ee8b8090 JH |
452 | |
453 | { | |
454 | if (outblock->conn_args) | |
455 | { | |
456 | blob early_data = { .data = outblock->buffer, .len = n }; | |
457 | ||
458 | /* We ignore the more-flag if we're doing a connect with early-data, which | |
459 | means we won't get BDAT+data. A pity, but wise due to the idempotency | |
460 | requirement: TFO with data can, in rare cases, replay the data to the | |
461 | receiver. */ | |
462 | ||
463 | if ( (outblock->cctx->sock = smtp_connect(outblock->conn_args, &early_data)) | |
464 | < 0) | |
465 | return FALSE; | |
466 | outblock->conn_args = NULL; | |
467 | rc = n; | |
468 | } | |
469 | else | |
470 | ||
471 | rc = send(outblock->cctx->sock, outblock->buffer, n, | |
4e910c01 | 472 | #ifdef MSG_MORE |
ee8b8090 | 473 | more ? MSG_MORE : 0 |
4e910c01 | 474 | #else |
ee8b8090 | 475 | 0 |
4e910c01 | 476 | #endif |
ee8b8090 JH |
477 | ); |
478 | } | |
059ec3d9 | 479 | |
059ec3d9 PH |
480 | if (rc <= 0) |
481 | { | |
e1d04f48 | 482 | HDEBUG(D_transport|D_acl) debug_printf_indent("send failed: %s\n", strerror(errno)); |
059ec3d9 PH |
483 | return FALSE; |
484 | } | |
485 | ||
486 | outblock->ptr = outblock->buffer; | |
487 | outblock->cmd_count = 0; | |
488 | return TRUE; | |
489 | } | |
490 | ||
491 | ||
492 | ||
493 | /************************************************* | |
494 | * Write SMTP command * | |
495 | *************************************************/ | |
496 | ||
497 | /* The formatted command is left in big_buffer so that it can be reflected in | |
498 | any error message. | |
499 | ||
500 | Arguments: | |
251b9eb4 | 501 | sx SMTP connection, contains buffer for pipelining, and socket |
4e910c01 | 502 | mode buffer, write-with-more-likely, write |
059ec3d9 PH |
503 | format a format, starting with one of |
504 | of HELO, MAIL FROM, RCPT TO, DATA, ".", or QUIT. | |
6d5c916c | 505 | If NULL, flush pipeline buffer only. |
059ec3d9 PH |
506 | ... data for the format |
507 | ||
508 | Returns: 0 if command added to pipelining buffer, with nothing transmitted | |
509 | +n if n commands transmitted (may still have buffered the new one) | |
510 | -1 on error, with errno set | |
511 | */ | |
512 | ||
513 | int | |
251b9eb4 | 514 | smtp_write_command(void * sx, int mode, const char *format, ...) |
059ec3d9 | 515 | { |
251b9eb4 | 516 | smtp_outblock * outblock = &((smtp_context *)sx)->outblock; |
059ec3d9 | 517 | int rc = 0; |
059ec3d9 | 518 | |
6d5c916c | 519 | if (format) |
059ec3d9 | 520 | { |
d12746bc JH |
521 | gstring gs = { .size = big_buffer_size, .ptr = 0, .s = big_buffer }; |
522 | va_list ap; | |
523 | ||
6d5c916c | 524 | va_start(ap, format); |
d12746bc | 525 | if (!string_vformat(&gs, FALSE, CS format, ap)) |
6d5c916c JH |
526 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong write_command in outgoing " |
527 | "SMTP"); | |
528 | va_end(ap); | |
d12746bc | 529 | string_from_gstring(&gs); |
6d5c916c | 530 | |
d12746bc | 531 | if (gs.ptr > outblock->buffersize) |
6d5c916c JH |
532 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong write_command in outgoing " |
533 | "SMTP"); | |
534 | ||
d12746bc | 535 | if (gs.ptr > outblock->buffersize - (outblock->ptr - outblock->buffer)) |
6d5c916c JH |
536 | { |
537 | rc = outblock->cmd_count; /* flush resets */ | |
4e910c01 | 538 | if (!flush_buffer(outblock, SCMD_FLUSH)) return -1; |
6d5c916c | 539 | } |
059ec3d9 | 540 | |
d12746bc JH |
541 | Ustrncpy(CS outblock->ptr, gs.s, gs.ptr); |
542 | outblock->ptr += gs.ptr; | |
6d5c916c | 543 | outblock->cmd_count++; |
d12746bc | 544 | gs.ptr -= 2; string_from_gstring(&gs); /* remove \r\n for error message */ |
059ec3d9 | 545 | |
6d5c916c JH |
546 | /* We want to hide the actual data sent in AUTH transactions from reflections |
547 | and logs. While authenticating, a flag is set in the outblock to enable this. | |
548 | The AUTH command itself gets any data flattened. Other lines are flattened | |
549 | completely. */ | |
059ec3d9 | 550 | |
6d5c916c | 551 | if (outblock->authenticating) |
059ec3d9 | 552 | { |
6d5c916c JH |
553 | uschar *p = big_buffer; |
554 | if (Ustrncmp(big_buffer, "AUTH ", 5) == 0) | |
555 | { | |
556 | p += 5; | |
557 | while (isspace(*p)) p++; | |
558 | while (!isspace(*p)) p++; | |
559 | while (isspace(*p)) p++; | |
560 | } | |
561 | while (*p != 0) *p++ = '*'; | |
059ec3d9 | 562 | } |
059ec3d9 | 563 | |
e1d04f48 | 564 | HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> %s\n", big_buffer); |
6d5c916c | 565 | } |
059ec3d9 | 566 | |
4e910c01 | 567 | if (mode != SCMD_BUFFER) |
059ec3d9 PH |
568 | { |
569 | rc += outblock->cmd_count; /* flush resets */ | |
4e910c01 | 570 | if (!flush_buffer(outblock, mode)) return -1; |
059ec3d9 PH |
571 | } |
572 | ||
573 | return rc; | |
574 | } | |
575 | ||
576 | ||
577 | ||
578 | /************************************************* | |
579 | * Read one line of SMTP response * | |
580 | *************************************************/ | |
581 | ||
582 | /* This function reads one line of SMTP response from the server host. This may | |
583 | not be a complete response - it could be just part of a multiline response. We | |
584 | have to use a buffer for incoming packets, because when pipelining or using | |
585 | LMTP, there may well be more than one response in a single packet. This | |
586 | function is called only from the one that follows. | |
587 | ||
588 | Arguments: | |
589 | inblock the SMTP input block (contains holding buffer, socket, etc.) | |
590 | buffer where to put the line | |
591 | size space available for the line | |
592 | timeout the timeout to use when reading a packet | |
593 | ||
594 | Returns: length of a line that has been put in the buffer | |
595 | -1 otherwise, with errno set | |
596 | */ | |
597 | ||
598 | static int | |
599 | read_response_line(smtp_inblock *inblock, uschar *buffer, int size, int timeout) | |
600 | { | |
601 | uschar *p = buffer; | |
602 | uschar *ptr = inblock->ptr; | |
603 | uschar *ptrend = inblock->ptrend; | |
74f1a423 | 604 | client_conn_ctx * cctx = inblock->cctx; |
059ec3d9 PH |
605 | |
606 | /* Loop for reading multiple packets or reading another packet after emptying | |
607 | a previously-read one. */ | |
608 | ||
609 | for (;;) | |
610 | { | |
611 | int rc; | |
612 | ||
613 | /* If there is data in the input buffer left over from last time, copy | |
614 | characters from it until the end of a line, at which point we can return, | |
615 | having removed any whitespace (which will include CR) at the end of the line. | |
616 | The rules for SMTP say that lines end in CRLF, but there are have been cases | |
617 | of hosts using just LF, and other MTAs are reported to handle this, so we | |
618 | just look for LF. If we run out of characters before the end of a line, | |
619 | carry on to read the next incoming packet. */ | |
620 | ||
621 | while (ptr < ptrend) | |
622 | { | |
623 | int c = *ptr++; | |
624 | if (c == '\n') | |
625 | { | |
626 | while (p > buffer && isspace(p[-1])) p--; | |
627 | *p = 0; | |
628 | inblock->ptr = ptr; | |
629 | return p - buffer; | |
630 | } | |
631 | *p++ = c; | |
632 | if (--size < 4) | |
633 | { | |
634 | *p = 0; /* Leave malformed line for error message */ | |
635 | errno = ERRNO_SMTPFORMAT; | |
636 | return -1; | |
637 | } | |
638 | } | |
639 | ||
640 | /* Need to read a new input packet. */ | |
641 | ||
74f1a423 | 642 | if((rc = ip_recv(cctx, inblock->buffer, inblock->buffersize, timeout)) <= 0) |
de6273b4 | 643 | { |
eebcfa1c | 644 | DEBUG(D_deliver|D_transport|D_acl|D_v) |
170f4904 JH |
645 | debug_printf_indent(errno ? " SMTP(%s)<<\n" : " SMTP(closed)<<\n", |
646 | strerror(errno)); | |
de6273b4 JH |
647 | break; |
648 | } | |
059ec3d9 PH |
649 | |
650 | /* Another block of data has been successfully read. Set up the pointers | |
651 | and let the loop continue. */ | |
652 | ||
653 | ptrend = inblock->ptrend = inblock->buffer + rc; | |
654 | ptr = inblock->buffer; | |
e1d04f48 | 655 | DEBUG(D_transport|D_acl) debug_printf_indent("read response data: size=%d\n", rc); |
059ec3d9 PH |
656 | } |
657 | ||
658 | /* Get here if there has been some kind of recv() error; errno is set, but we | |
659 | ensure that the result buffer is empty before returning. */ | |
660 | ||
661 | *buffer = 0; | |
662 | return -1; | |
663 | } | |
664 | ||
665 | ||
666 | ||
667 | ||
668 | ||
669 | /************************************************* | |
670 | * Read SMTP response * | |
671 | *************************************************/ | |
672 | ||
673 | /* This function reads an SMTP response with a timeout, and returns the | |
674 | response in the given buffer, as a string. A multiline response will contain | |
675 | newline characters between the lines. The function also analyzes the first | |
676 | digit of the reply code and returns FALSE if it is not acceptable. FALSE is | |
677 | also returned after a reading error. In this case buffer[0] will be zero, and | |
678 | the error code will be in errno. | |
679 | ||
680 | Arguments: | |
251b9eb4 JH |
681 | sx the SMTP connection (contains input block with holding buffer, |
682 | socket, etc.) | |
059ec3d9 PH |
683 | buffer where to put the response |
684 | size the size of the buffer | |
685 | okdigit the expected first digit of the response | |
2760b518 | 686 | timeout the timeout to use, in seconds |
059ec3d9 PH |
687 | |
688 | Returns: TRUE if a valid, non-error response was received; else FALSE | |
689 | */ | |
ee8b8090 | 690 | /*XXX could move to smtp transport; no other users */ |
059ec3d9 PH |
691 | |
692 | BOOL | |
fc243e94 | 693 | smtp_read_response(void * sx0, uschar * buffer, int size, int okdigit, |
059ec3d9 PH |
694 | int timeout) |
695 | { | |
ee8b8090 | 696 | smtp_context * sx = sx0; |
fc243e94 | 697 | uschar * ptr = buffer; |
dca6d121 | 698 | int count = 0; |
059ec3d9 PH |
699 | |
700 | errno = 0; /* Ensure errno starts out zero */ | |
701 | ||
4e48d56c | 702 | #ifdef SUPPORT_PIPE_CONNECT |
ee8b8090 | 703 | if (sx->pending_BANNER || sx->pending_EHLO) |
dca6d121 JH |
704 | { |
705 | int rc; | |
fc243e94 | 706 | if ((rc = smtp_reap_early_pipe(sx, &count)) != OK) |
ee8b8090 JH |
707 | { |
708 | DEBUG(D_transport) debug_printf("failed reaping pipelined cmd responsess\n"); | |
fc243e94 JH |
709 | buffer[0] = '\0'; |
710 | if (rc == DEFER) errno = ERRNO_TLSFAILURE; | |
ee8b8090 JH |
711 | return FALSE; |
712 | } | |
dca6d121 | 713 | } |
ee8b8090 JH |
714 | #endif |
715 | ||
4c04137d | 716 | /* This is a loop to read and concatenate the lines that make up a multi-line |
059ec3d9 PH |
717 | response. */ |
718 | ||
719 | for (;;) | |
720 | { | |
ee8b8090 | 721 | if ((count = read_response_line(&sx->inblock, ptr, size, timeout)) < 0) |
059ec3d9 PH |
722 | return FALSE; |
723 | ||
724 | HDEBUG(D_transport|D_acl|D_v) | |
ee8b8090 | 725 | debug_printf_indent(" %s %s\n", ptr == buffer ? "SMTP<<" : " ", ptr); |
059ec3d9 PH |
726 | |
727 | /* Check the format of the response: it must start with three digits; if | |
728 | these are followed by a space or end of line, the response is complete. If | |
729 | they are followed by '-' this is a multi-line response and we must look for | |
730 | another line until the final line is reached. The only use made of multi-line | |
731 | responses is to pass them back as error messages. We therefore just | |
732 | concatenate them all within the buffer, which should be large enough to | |
733 | accept any reasonable number of lines. */ | |
734 | ||
735 | if (count < 3 || | |
736 | !isdigit(ptr[0]) || | |
737 | !isdigit(ptr[1]) || | |
738 | !isdigit(ptr[2]) || | |
739 | (ptr[3] != '-' && ptr[3] != ' ' && ptr[3] != 0)) | |
740 | { | |
741 | errno = ERRNO_SMTPFORMAT; /* format error */ | |
742 | return FALSE; | |
743 | } | |
744 | ||
745 | /* If the line we have just read is a terminal line, line, we are done. | |
746 | Otherwise more data has to be read. */ | |
747 | ||
748 | if (ptr[3] != '-') break; | |
749 | ||
750 | /* Move the reading pointer upwards in the buffer and insert \n between the | |
751 | components of a multiline response. Space is left for this by read_response_ | |
752 | line(). */ | |
753 | ||
754 | ptr += count; | |
755 | *ptr++ = '\n'; | |
756 | size -= count + 1; | |
757 | } | |
758 | ||
ee8b8090 JH |
759 | #ifdef TCP_FASTOPEN |
760 | tfo_out_check(sx->cctx.sock); | |
761 | #endif | |
762 | ||
059ec3d9 PH |
763 | /* Return a value that depends on the SMTP return code. On some systems a |
764 | non-zero value of errno has been seen at this point, so ensure it is zero, | |
765 | because the caller of this function looks at errno when FALSE is returned, to | |
766 | distinguish between an unexpected return code and other errors such as | |
767 | timeouts, lost connections, etc. */ | |
768 | ||
769 | errno = 0; | |
770 | return buffer[0] == okdigit; | |
771 | } | |
772 | ||
773 | /* End of smtp_out.c */ | |
7eb6c37c JH |
774 | /* vi: aw ai sw=2 |
775 | */ |