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 <malloc_np.h>
39 #include <signal.h>
40 #include <strings.h>
41 #include <string.h>
42 #include <syslog.h>
43 #include <unistd.h>
44
45 #include "dma.h"
46
47 #define MAX_LINE_RFC822 999 /* 998 characters plus \n */
48
49 void
bounce(struct qitem * it,const char * reason)50 bounce(struct qitem *it, const char *reason)
51 {
52 struct queue bounceq;
53 char line[1000];
54 size_t pos;
55 int error;
56
57 /* Don't bounce bounced mails */
58 if (it->sender[0] == 0) {
59 syslog(LOG_INFO, "can not bounce a bounce message, discarding");
60 exit(EX_SOFTWARE);
61 }
62
63 bzero(&bounceq, sizeof(bounceq));
64 LIST_INIT(&bounceq.queue);
65 bounceq.sender = "";
66 if (add_recp(&bounceq, it->sender, EXPAND_WILDCARD) != 0)
67 goto fail;
68
69 if (newspoolf(&bounceq) != 0)
70 goto fail;
71
72 syslog(LOG_ERR, "delivery failed, bouncing as %s", bounceq.id);
73 setlogident("%s", bounceq.id);
74
75 error = fprintf(bounceq.mailf,
76 "Received: from MAILER-DAEMON\n"
77 "\tid %s\n"
78 "\tby %s (%s on %s);\n"
79 "\t%s\n"
80 "X-Original-To: <%s>\n"
81 "From: MAILER-DAEMON <>\n"
82 "To: %s\n"
83 "Subject: Mail delivery failed\n"
84 "Message-Id: <%s@%s>\n"
85 "Date: %s\n"
86 "\n"
87 "This is the %s at %s.\n"
88 "\n"
89 "There was an error delivering your mail to <%s>.\n"
90 "\n"
91 "%s\n"
92 "\n"
93 "%s\n"
94 "\n",
95 bounceq.id,
96 hostname(), VERSION, systemhostname(),
97 rfc822date(),
98 it->addr,
99 it->sender,
100 bounceq.id, hostname(),
101 rfc822date(),
102 VERSION, hostname(),
103 it->addr,
104 reason,
105 config.features & FULLBOUNCE ?
106 "Original message follows." :
107 "Message headers follow.");
108 if (error < 0)
109 goto fail;
110
111 if (fseek(it->mailf, 0, SEEK_SET) != 0)
112 goto fail;
113 if (config.features & FULLBOUNCE) {
114 while ((pos = fread(line, 1, sizeof(line), it->mailf)) > 0) {
115 if (fwrite(line, 1, pos, bounceq.mailf) != pos)
116 goto fail;
117 }
118 } else {
119 while (!feof(it->mailf)) {
120 if (fgets(line, sizeof(line), it->mailf) == NULL)
121 break;
122 if (line[0] == '\n')
123 break;
124 if (fwrite(line, strlen(line), 1, bounceq.mailf) != 1)
125 goto fail;
126 }
127 }
128
129 if (linkspool(&bounceq) != 0)
130 goto fail;
131 /* bounce is safe */
132
133 delqueue(it);
134
135 run_queue(&bounceq);
136 /* NOTREACHED */
137
138 fail:
139 syslog(LOG_CRIT, "error creating bounce: %m");
140 delqueue(it);
141 exit(EX_IOERR);
142 }
143
144 struct parse_state {
145 char addr[1000];
146 int pos;
147
148 enum {
149 NONE = 0,
150 START,
151 MAIN,
152 EOL,
153 QUIT
154 } state;
155 int comment;
156 int quote;
157 int brackets;
158 int esc;
159 };
160
161 /*
162 * Simplified RFC2822 header/address parsing.
163 * We copy escapes and quoted strings directly, since
164 * we have to pass them like this to the mail server anyways.
165 * XXX local addresses will need treatment
166 */
167 static int
parse_addrs(struct parse_state * ps,char * s,struct queue * queue)168 parse_addrs(struct parse_state *ps, char *s, struct queue *queue)
169 {
170 char *addr;
171
172 again:
173 switch (ps->state) {
174 case NONE:
175 return (-1);
176
177 case START:
178 /* init our data */
179 bzero(ps, sizeof(*ps));
180
181 /* skip over header name */
182 while (*s != ':')
183 s++;
184 s++;
185 ps->state = MAIN;
186 break;
187
188 case MAIN:
189 /* all fine */
190 break;
191
192 case EOL:
193 switch (*s) {
194 case ' ':
195 case '\t':
196 ps->state = MAIN;
197 break;
198
199 default:
200 ps->state = QUIT;
201 if (ps->pos != 0)
202 goto newaddr;
203 return (0);
204 }
205 break;
206
207 case QUIT:
208 return (0);
209 }
210
211 for (; *s != 0; s++) {
212 if (ps->esc) {
213 ps->esc = 0;
214
215 switch (*s) {
216 case '\r':
217 case '\n':
218 goto err;
219
220 default:
221 goto copy;
222 }
223 }
224
225 if (ps->quote) {
226 switch (*s) {
227 case '"':
228 ps->quote = 0;
229 goto copy;
230
231 case '\\':
232 ps->esc = 1;
233 goto copy;
234
235 case '\r':
236 case '\n':
237 goto eol;
238
239 default:
240 goto copy;
241 }
242 }
243
244 switch (*s) {
245 case '(':
246 ps->comment++;
247 break;
248
249 case ')':
250 if (ps->comment)
251 ps->comment--;
252 else
253 goto err;
254 goto skip;
255
256 case '"':
257 ps->quote = 1;
258 goto copy;
259
260 case '\\':
261 ps->esc = 1;
262 goto copy;
263
264 case '\r':
265 case '\n':
266 goto eol;
267 }
268
269 if (ps->comment)
270 goto skip;
271
272 switch (*s) {
273 case ' ':
274 case '\t':
275 /* ignore whitespace */
276 goto skip;
277
278 case '<':
279 /* this is the real address now */
280 ps->brackets = 1;
281 ps->pos = 0;
282 goto skip;
283
284 case '>':
285 if (!ps->brackets)
286 goto err;
287 ps->brackets = 0;
288
289 s++;
290 goto newaddr;
291
292 case ':':
293 /* group - ignore */
294 ps->pos = 0;
295 goto skip;
296
297 case ',':
298 case ';':
299 /*
300 * Next address, copy previous one.
301 * However, we might be directly after
302 * a <address>, or have two consecutive
303 * commas.
304 * Skip the comma unless there is
305 * really something to copy.
306 */
307 if (ps->pos == 0)
308 goto skip;
309 s++;
310 goto newaddr;
311
312 default:
313 goto copy;
314 }
315
316 copy:
317 if (ps->comment)
318 goto skip;
319
320 if (ps->pos + 1 == sizeof(ps->addr))
321 goto err;
322 ps->addr[ps->pos++] = *s;
323
324 skip:
325 ;
326 }
327
328 eol:
329 ps->state = EOL;
330 return (0);
331
332 err:
333 ps->state = QUIT;
334 return (-1);
335
336 newaddr:
337 ps->addr[ps->pos] = 0;
338 ps->pos = 0;
339 addr = strdup(ps->addr);
340 if (addr == NULL)
341 errlog(EX_SOFTWARE, "strdup");
342
343 if (add_recp(queue, addr, EXPAND_WILDCARD) != 0)
344 errlogx(EX_DATAERR, "invalid recipient `%s'", addr);
345
346 goto again;
347 }
348
349 static int
writeline(struct queue * queue,const char * line,ssize_t linelen)350 writeline(struct queue *queue, const char *line, ssize_t linelen)
351 {
352 ssize_t len;
353
354 while (linelen > 0) {
355 len = linelen;
356 if (linelen > MAX_LINE_RFC822) {
357 len = MAX_LINE_RFC822 - 10;
358 }
359
360 if (fwrite(line, len, 1, queue->mailf) != 1)
361 return (-1);
362
363 if (linelen <= MAX_LINE_RFC822)
364 break;
365
366 if (fwrite("\n", 1, 1, queue->mailf) != 1)
367 return (-1);
368
369 line += MAX_LINE_RFC822 - 10;
370 linelen = strlen(line);
371 }
372 return (0);
373 }
374
375 int
readmail(struct queue * queue,int nodot,int recp_from_header)376 readmail(struct queue *queue, int nodot, int recp_from_header)
377 {
378 struct parse_state parse_state;
379 char *line = NULL;
380 ssize_t linelen;
381 size_t linecap = 0;
382 char newline[MAX_LINE_RFC822 + 1];
383 size_t error;
384 int had_headers = 0;
385 int had_from = 0;
386 int had_messagid = 0;
387 int had_date = 0;
388 int had_first_line = 0;
389 int had_last_line = 0;
390 int nocopy = 0;
391 int ret = -1;
392
393 parse_state.state = NONE;
394
395 error = fprintf(queue->mailf,
396 "Received: from %s (uid %d)\n"
397 "\t(envelope-from %s)\n"
398 "\tid %s\n"
399 "\tby %s (%s on %s);\n"
400 "\t%s\n",
401 username, useruid,
402 queue->sender,
403 queue->id,
404 hostname(), VERSION, systemhostname(),
405 rfc822date());
406 if ((ssize_t)error < 0)
407 return (-1);
408
409 while ((linelen = getline(&line, &linecap, stdin)) > 0) {
410 newline[0] = '\0';
411 if (had_last_line)
412 errlogx(EX_DATAERR, "bad mail input format:"
413 " from %s (uid %d) (envelope-from %s)",
414 username, useruid, queue->sender);
415 linelen = strlen(line);
416 if (linelen == 0 || line[linelen - 1] != '\n') {
417 /*
418 * This line did not end with a newline character.
419 * If we fix it, it better be the last line of
420 * the file.
421 */
422 if ((size_t)linelen + 1 > linecap) {
423 line = realloc(line, linelen + 2);
424 if (line == NULL)
425 errlogx(EX_SOFTWARE, "realloc");
426 linecap = malloc_usable_size(line);
427 }
428 line[linelen++] = '\n';
429 line[linelen] = 0;
430 had_last_line = 1;
431 }
432 if (!had_first_line) {
433 /*
434 * Ignore a leading RFC-976 From_ or >From_ line mistakenly
435 * inserted by some programs.
436 */
437 if (strprefixcmp(line, "From ") == 0 || strprefixcmp(line, ">From ") == 0)
438 continue;
439 had_first_line = 1;
440 }
441 if (!had_headers) {
442 if (linelen > MAX_LINE_RFC822) {
443 /* XXX also split headers */
444 errlogx(EX_DATAERR, "bad mail input format:"
445 " from %s (uid %d) (envelope-from %s)",
446 username, useruid, queue->sender);
447 }
448 /*
449 * Unless this is a continuation, switch of
450 * the Bcc: nocopy flag.
451 */
452 if (!(line[0] == ' ' || line[0] == '\t'))
453 nocopy = 0;
454
455 if (strprefixcmp(line, "Date:") == 0)
456 had_date = 1;
457 else if (strprefixcmp(line, "Message-Id:") == 0)
458 had_messagid = 1;
459 else if (strprefixcmp(line, "From:") == 0)
460 had_from = 1;
461 else if (strprefixcmp(line, "Bcc:") == 0)
462 nocopy = 1;
463
464 if (parse_state.state != NONE) {
465 if (parse_addrs(&parse_state, line, queue) < 0) {
466 errlogx(EX_DATAERR, "invalid address in header\n");
467 /* NOTREACHED */
468 }
469 }
470
471 if (recp_from_header && (
472 strprefixcmp(line, "To:") == 0 ||
473 strprefixcmp(line, "Cc:") == 0 ||
474 strprefixcmp(line, "Bcc:") == 0)) {
475 parse_state.state = START;
476 if (parse_addrs(&parse_state, line, queue) < 0) {
477 errlogx(EX_DATAERR, "invalid address in header\n");
478 /* NOTREACHED */
479 }
480 }
481 }
482
483 if (strcmp(line, "\n") == 0 && !had_headers) {
484 had_headers = 1;
485 while (!had_date || !had_messagid || !had_from) {
486 if (!had_date) {
487 had_date = 1;
488 snprintf(newline, sizeof(newline), "Date: %s\n", rfc822date());
489 } else if (!had_messagid) {
490 /* XXX msgid, assign earlier and log? */
491 had_messagid = 1;
492 snprintf(newline, sizeof(newline), "Message-Id: <%"PRIxMAX".%s.%"PRIxMAX"@%s>\n",
493 (uintmax_t)time(NULL),
494 queue->id,
495 (uintmax_t)random(),
496 hostname());
497 } else if (!had_from) {
498 had_from = 1;
499 snprintf(newline, sizeof(newline), "From: <%s>\n", queue->sender);
500 }
501 if (fwrite(newline, strlen(newline), 1, queue->mailf) != 1)
502 goto fail;
503 }
504 strlcpy(newline, "\n", sizeof(newline));
505 }
506 if (!nodot && linelen == 2 && line[0] == '.')
507 break;
508 if (!nocopy) {
509 if (newline[0]) {
510 if (fwrite(newline, strlen(newline), 1, queue->mailf) != 1)
511 goto fail;
512 } else {
513 if (writeline(queue, line, linelen) != 0)
514 goto fail;
515 }
516 }
517 }
518 if (ferror(stdin) == 0)
519 ret = 0;
520 fail:
521 free(line);
522 return (ret);
523 }
524