1 /*
2 * Copyright (c) 2008-2014, Simon Schubert <2@0x2c.org>.
3 * Copyright (c) 2008 The DragonFly Project. All rights reserved.
4 *
5 * This code is derived from software contributed to The DragonFly Project
6 * by Simon Schubert <2@0x2c.org>.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in
16 * the documentation and/or other materials provided with the
17 * distribution.
18 * 3. Neither the name of The DragonFly Project nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific, prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
28 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
29 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
30 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include <errno.h>
37 #include <inttypes.h>
38 #include <signal.h>
39 #include <strings.h>
40 #include <string.h>
41 #include <syslog.h>
42 #include <unistd.h>
43
44 #include "dma.h"
45
46 #define MAX_LINE_RFC822 1000
47
48 void
bounce(struct qitem * it,const char * reason)49 bounce(struct qitem *it, const char *reason)
50 {
51 struct queue bounceq;
52 char line[1000];
53 size_t pos;
54 int error;
55
56 /* Don't bounce bounced mails */
57 if (it->sender[0] == 0) {
58 syslog(LOG_INFO, "can not bounce a bounce message, discarding");
59 exit(EX_SOFTWARE);
60 }
61
62 bzero(&bounceq, sizeof(bounceq));
63 LIST_INIT(&bounceq.queue);
64 bounceq.sender = "";
65 if (add_recp(&bounceq, it->sender, EXPAND_WILDCARD) != 0)
66 goto fail;
67
68 if (newspoolf(&bounceq) != 0)
69 goto fail;
70
71 syslog(LOG_ERR, "delivery failed, bouncing as %s", bounceq.id);
72 setlogident("%s", bounceq.id);
73
74 error = fprintf(bounceq.mailf,
75 "Received: from MAILER-DAEMON\n"
76 "\tid %s\n"
77 "\tby %s (%s on %s);\n"
78 "\t%s\n"
79 "X-Original-To: <%s>\n"
80 "From: MAILER-DAEMON <>\n"
81 "To: %s\n"
82 "Subject: Mail delivery failed\n"
83 "Message-Id: <%s@%s>\n"
84 "Date: %s\n"
85 "\n"
86 "This is the %s at %s.\n"
87 "\n"
88 "There was an error delivering your mail to <%s>.\n"
89 "\n"
90 "%s\n"
91 "\n"
92 "%s\n"
93 "\n",
94 bounceq.id,
95 hostname(), VERSION, systemhostname(),
96 rfc822date(),
97 it->addr,
98 it->sender,
99 bounceq.id, hostname(),
100 rfc822date(),
101 VERSION, hostname(),
102 it->addr,
103 reason,
104 config.features & FULLBOUNCE ?
105 "Original message follows." :
106 "Message headers follow.");
107 if (error < 0)
108 goto fail;
109
110 if (fseek(it->mailf, 0, SEEK_SET) != 0)
111 goto fail;
112 if (config.features & FULLBOUNCE) {
113 while ((pos = fread(line, 1, sizeof(line), it->mailf)) > 0) {
114 if (fwrite(line, 1, pos, bounceq.mailf) != pos)
115 goto fail;
116 }
117 } else {
118 while (!feof(it->mailf)) {
119 if (fgets(line, sizeof(line), it->mailf) == NULL)
120 break;
121 if (line[0] == '\n')
122 break;
123 if (fwrite(line, strlen(line), 1, bounceq.mailf) != 1)
124 goto fail;
125 }
126 }
127
128 if (linkspool(&bounceq) != 0)
129 goto fail;
130 /* bounce is safe */
131
132 delqueue(it);
133
134 run_queue(&bounceq);
135 /* NOTREACHED */
136
137 fail:
138 syslog(LOG_CRIT, "error creating bounce: %m");
139 delqueue(it);
140 exit(EX_IOERR);
141 }
142
143 struct parse_state {
144 char addr[1000];
145 int pos;
146
147 enum {
148 NONE = 0,
149 START,
150 MAIN,
151 EOL,
152 QUIT
153 } state;
154 int comment;
155 int quote;
156 int brackets;
157 int esc;
158 };
159
160 /*
161 * Simplified RFC2822 header/address parsing.
162 * We copy escapes and quoted strings directly, since
163 * we have to pass them like this to the mail server anyways.
164 * XXX local addresses will need treatment
165 */
166 static int
parse_addrs(struct parse_state * ps,char * s,struct queue * queue)167 parse_addrs(struct parse_state *ps, char *s, struct queue *queue)
168 {
169 char *addr;
170
171 again:
172 switch (ps->state) {
173 case NONE:
174 return (-1);
175
176 case START:
177 /* init our data */
178 bzero(ps, sizeof(*ps));
179
180 /* skip over header name */
181 while (*s != ':')
182 s++;
183 s++;
184 ps->state = MAIN;
185 break;
186
187 case MAIN:
188 /* all fine */
189 break;
190
191 case EOL:
192 switch (*s) {
193 case ' ':
194 case '\t':
195 s++;
196 /* continue */
197 break;
198
199 default:
200 ps->state = QUIT;
201 if (ps->pos != 0)
202 goto newaddr;
203 return (0);
204 }
205 /* FALLTHROUGH */
206 case QUIT:
207 return (0);
208 }
209
210 for (; *s != 0; s++) {
211 if (ps->esc) {
212 ps->esc = 0;
213
214 switch (*s) {
215 case '\r':
216 case '\n':
217 goto err;
218
219 default:
220 goto copy;
221 }
222 }
223
224 if (ps->quote) {
225 switch (*s) {
226 case '"':
227 ps->quote = 0;
228 goto copy;
229
230 case '\\':
231 ps->esc = 1;
232 goto copy;
233
234 case '\r':
235 case '\n':
236 goto eol;
237
238 default:
239 goto copy;
240 }
241 }
242
243 switch (*s) {
244 case '(':
245 ps->comment++;
246 break;
247
248 case ')':
249 if (ps->comment)
250 ps->comment--;
251 else
252 goto err;
253 goto skip;
254
255 case '"':
256 ps->quote = 1;
257 goto copy;
258
259 case '\\':
260 ps->esc = 1;
261 goto copy;
262
263 case '\r':
264 case '\n':
265 goto eol;
266 }
267
268 if (ps->comment)
269 goto skip;
270
271 switch (*s) {
272 case ' ':
273 case '\t':
274 /* ignore whitespace */
275 goto skip;
276
277 case '<':
278 /* this is the real address now */
279 ps->brackets = 1;
280 ps->pos = 0;
281 goto skip;
282
283 case '>':
284 if (!ps->brackets)
285 goto err;
286 ps->brackets = 0;
287
288 s++;
289 goto newaddr;
290
291 case ':':
292 /* group - ignore */
293 ps->pos = 0;
294 goto skip;
295
296 case ',':
297 case ';':
298 /*
299 * Next address, copy previous one.
300 * However, we might be directly after
301 * a <address>, or have two consecutive
302 * commas.
303 * Skip the comma unless there is
304 * really something to copy.
305 */
306 if (ps->pos == 0)
307 goto skip;
308 s++;
309 goto newaddr;
310
311 default:
312 goto copy;
313 }
314
315 copy:
316 if (ps->comment)
317 goto skip;
318
319 if (ps->pos + 1 == sizeof(ps->addr))
320 goto err;
321 ps->addr[ps->pos++] = *s;
322
323 skip:
324 ;
325 }
326
327 eol:
328 ps->state = EOL;
329 return (0);
330
331 err:
332 ps->state = QUIT;
333 return (-1);
334
335 newaddr:
336 ps->addr[ps->pos] = 0;
337 ps->pos = 0;
338 addr = strdup(ps->addr);
339 if (addr == NULL)
340 errlog(EX_SOFTWARE, NULL);
341
342 if (add_recp(queue, addr, EXPAND_WILDCARD) != 0)
343 errlogx(EX_DATAERR, "invalid recipient `%s'", addr);
344
345 goto again;
346 }
347
348 static int
writeline(struct queue * queue,const char * line,ssize_t linelen)349 writeline(struct queue *queue, const char *line, ssize_t linelen)
350 {
351 ssize_t len;
352
353 while (linelen > 0) {
354 len = linelen;
355 if (linelen > MAX_LINE_RFC822) {
356 len = MAX_LINE_RFC822 - 10;
357 }
358
359 if (fwrite(line, len, 1, queue->mailf) != 1)
360 return (-1);
361
362 if (linelen <= MAX_LINE_RFC822)
363 break;
364
365 if (fwrite("\n", 1, 1, queue->mailf) != 1)
366 return (-1);
367
368 line += MAX_LINE_RFC822 - 10;
369 linelen = strlen(line);
370 }
371 return (0);
372 }
373
374 int
readmail(struct queue * queue,int nodot,int recp_from_header)375 readmail(struct queue *queue, int nodot, int recp_from_header)
376 {
377 struct parse_state parse_state;
378 char *line = NULL;
379 ssize_t linelen;
380 size_t linecap = 0;
381 char newline[MAX_LINE_RFC822];
382 size_t error;
383 int had_headers = 0;
384 int had_from = 0;
385 int had_messagid = 0;
386 int had_date = 0;
387 int had_first_line = 0;
388 int nocopy = 0;
389 int ret = -1;
390
391 parse_state.state = NONE;
392
393 error = fprintf(queue->mailf,
394 "Received: from %s (uid %d)\n"
395 "\t(envelope-from %s)\n"
396 "\tid %s\n"
397 "\tby %s (%s on %s);\n"
398 "\t%s\n",
399 username, useruid,
400 queue->sender,
401 queue->id,
402 hostname(), VERSION, systemhostname(),
403 rfc822date());
404 if ((ssize_t)error < 0)
405 return (-1);
406
407 while (!feof(stdin)) {
408 newline[0] = '\0';
409 if ((linelen = getline(&line, &linecap, stdin)) <= 0)
410 break;
411 if (!had_first_line) {
412 /*
413 * Ignore a leading RFC-976 From_ or >From_ line mistakenly
414 * inserted by some programs.
415 */
416 if (strprefixcmp(line, "From ") == 0 || strprefixcmp(line, ">From ") == 0)
417 continue;
418 had_first_line = 1;
419 }
420 if (!had_headers) {
421 if (linelen > MAX_LINE_RFC822) {
422 errlogx(EX_DATAERR, "bad mail input format:"
423 " from %s (uid %d) (envelope-from %s)",
424 username, useruid, queue->sender);
425 }
426 /*
427 * Unless this is a continuation, switch of
428 * the Bcc: nocopy flag.
429 */
430 if (!(line[0] == ' ' || line[0] == '\t'))
431 nocopy = 0;
432
433 if (strprefixcmp(line, "Date:") == 0)
434 had_date = 1;
435 else if (strprefixcmp(line, "Message-Id:") == 0)
436 had_messagid = 1;
437 else if (strprefixcmp(line, "From:") == 0)
438 had_from = 1;
439 else if (strprefixcmp(line, "Bcc:") == 0)
440 nocopy = 1;
441
442 if (parse_state.state != NONE) {
443 if (parse_addrs(&parse_state, line, queue) < 0) {
444 errlogx(EX_DATAERR, "invalid address in header\n");
445 /* NOTREACHED */
446 }
447 }
448
449 if (recp_from_header && (
450 strprefixcmp(line, "To:") == 0 ||
451 strprefixcmp(line, "Cc:") == 0 ||
452 strprefixcmp(line, "Bcc:") == 0)) {
453 parse_state.state = START;
454 if (parse_addrs(&parse_state, line, queue) < 0) {
455 errlogx(EX_DATAERR, "invalid address in header\n");
456 /* NOTREACHED */
457 }
458 }
459 }
460
461 if (strcmp(line, "\n") == 0 && !had_headers) {
462 had_headers = 1;
463 while (!had_date || !had_messagid || !had_from) {
464 if (!had_date) {
465 had_date = 1;
466 snprintf(newline, sizeof(newline), "Date: %s\n", rfc822date());
467 } else if (!had_messagid) {
468 /* XXX msgid, assign earlier and log? */
469 had_messagid = 1;
470 snprintf(newline, sizeof(newline), "Message-Id: <%"PRIxMAX".%s.%"PRIxMAX"@%s>\n",
471 (uintmax_t)time(NULL),
472 queue->id,
473 (uintmax_t)random(),
474 hostname());
475 } else if (!had_from) {
476 had_from = 1;
477 snprintf(newline, sizeof(newline), "From: <%s>\n", queue->sender);
478 }
479 if (fwrite(newline, strlen(newline), 1, queue->mailf) != 1)
480 goto fail;
481 }
482 strlcpy(newline, "\n", sizeof(newline));
483 }
484 if (!nodot && linelen == 2 && line[0] == '.')
485 break;
486 if (!nocopy) {
487 if (newline[0]) {
488 if (fwrite(newline, strlen(newline), 1, queue->mailf) != 1)
489 goto fail;
490 } else {
491 if (writeline(queue, line, linelen) != 0)
492 goto fail;
493 }
494 }
495 }
496
497 ret = 0;
498 fail:
499 free(line);
500 return (ret);
501 }
502