1 /*
2  * Copyright (c) 1983 Eric P. Allman
3  * Copyright (c) 1988 Regents of the University of California.
4  * All rights reserved.
5  *
6  * %sccs.include.redist.c%
7  */
8 
9 #ifndef lint
10 static char sccsid[] = "@(#)savemail.c	6.29 (Berkeley) 04/05/93";
11 #endif /* not lint */
12 
13 # include <pwd.h>
14 # include "sendmail.h"
15 
16 /*
17 **  SAVEMAIL -- Save mail on error
18 **
19 **	If mailing back errors, mail it back to the originator
20 **	together with an error message; otherwise, just put it in
21 **	dead.letter in the user's home directory (if he exists on
22 **	this machine).
23 **
24 **	Parameters:
25 **		e -- the envelope containing the message in error.
26 **
27 **	Returns:
28 **		none
29 **
30 **	Side Effects:
31 **		Saves the letter, by writing or mailing it back to the
32 **		sender, or by putting it in dead.letter in her home
33 **		directory.
34 */
35 
36 /* defines for state machine */
37 # define ESM_REPORT	0	/* report to sender's terminal */
38 # define ESM_MAIL	1	/* mail back to sender */
39 # define ESM_QUIET	2	/* messages have already been returned */
40 # define ESM_DEADLETTER	3	/* save in ~/dead.letter */
41 # define ESM_POSTMASTER	4	/* return to postmaster */
42 # define ESM_USRTMP	5	/* save in /usr/tmp/dead.letter */
43 # define ESM_PANIC	6	/* leave the locked queue/transcript files */
44 # define ESM_DONE	7	/* the message is successfully delivered */
45 
46 
47 savemail(e)
48 	register ENVELOPE *e;
49 {
50 	register struct passwd *pw;
51 	register FILE *fp;
52 	int state;
53 	auto ADDRESS *q;
54 	char buf[MAXLINE+1];
55 	extern struct passwd *getpwnam();
56 	register char *p;
57 	extern char *ttypath();
58 	typedef int (*fnptr)();
59 
60 	if (tTd(6, 1))
61 	{
62 		printf("\nsavemail, errormode = %c\n  e_from=", e->e_errormode);
63 		printaddr(&e->e_from, FALSE);
64 	}
65 
66 	if (bitset(EF_RESPONSE, e->e_flags))
67 		return;
68 	e->e_flags &= ~EF_FATALERRS;
69 
70 	/*
71 	**  In the unhappy event we don't know who to return the mail
72 	**  to, make someone up.
73 	*/
74 
75 	if (e->e_from.q_paddr == NULL)
76 	{
77 		e->e_sender = "Postmaster";
78 		if (parseaddr(e->e_sender, &e->e_from, 0, '\0', NULL, e) == NULL)
79 		{
80 			syserr("553 Cannot parse Postmaster!");
81 			ExitStat = EX_SOFTWARE;
82 			finis();
83 		}
84 	}
85 	e->e_to = NULL;
86 
87 	/*
88 	**  Basic state machine.
89 	**
90 	**	This machine runs through the following states:
91 	**
92 	**	ESM_QUIET	Errors have already been printed iff the
93 	**			sender is local.
94 	**	ESM_REPORT	Report directly to the sender's terminal.
95 	**	ESM_MAIL	Mail response to the sender.
96 	**	ESM_DEADLETTER	Save response in ~/dead.letter.
97 	**	ESM_POSTMASTER	Mail response to the postmaster.
98 	**	ESM_PANIC	Save response anywhere possible.
99 	*/
100 
101 	/* determine starting state */
102 	switch (e->e_errormode)
103 	{
104 	  case EM_WRITE:
105 		state = ESM_REPORT;
106 		break;
107 
108 	  case EM_BERKNET:
109 		/* mail back, but return o.k. exit status */
110 		ExitStat = EX_OK;
111 
112 		/* fall through.... */
113 
114 	  case EM_MAIL:
115 		state = ESM_MAIL;
116 		break;
117 
118 	  case EM_PRINT:
119 	  case '\0':
120 		state = ESM_QUIET;
121 		break;
122 
123 	  case EM_QUIET:
124 		/* no need to return anything at all */
125 		return;
126 
127 	  default:
128 		syserr("554 savemail: bogus errormode x%x\n", e->e_errormode);
129 		state = ESM_MAIL;
130 		break;
131 	}
132 
133 	while (state != ESM_DONE)
134 	{
135 		if (tTd(6, 5))
136 			printf("  state %d\n", state);
137 
138 		switch (state)
139 		{
140 		  case ESM_QUIET:
141 			if (e->e_from.q_mailer == LocalMailer)
142 				state = ESM_DEADLETTER;
143 			else
144 				state = ESM_MAIL;
145 			break;
146 
147 		  case ESM_REPORT:
148 
149 			/*
150 			**  If the user is still logged in on the same terminal,
151 			**  then write the error messages back to hir (sic).
152 			*/
153 
154 			p = ttypath();
155 			if (p == NULL || freopen(p, "w", stdout) == NULL)
156 			{
157 				state = ESM_MAIL;
158 				break;
159 			}
160 
161 			expand("\201n", buf, &buf[sizeof buf - 1], e);
162 			printf("\r\nMessage from %s...\r\n", buf);
163 			printf("Errors occurred while sending mail.\r\n");
164 			if (e->e_xfp != NULL)
165 			{
166 				(void) fflush(e->e_xfp);
167 				fp = fopen(queuename(e, 'x'), "r");
168 			}
169 			else
170 				fp = NULL;
171 			if (fp == NULL)
172 			{
173 				syserr("Cannot open %s", queuename(e, 'x'));
174 				printf("Transcript of session is unavailable.\r\n");
175 			}
176 			else
177 			{
178 				printf("Transcript follows:\r\n");
179 				while (fgets(buf, sizeof buf, fp) != NULL &&
180 				       !ferror(stdout))
181 					fputs(buf, stdout);
182 				(void) xfclose(fp, "savemail transcript", e->e_id);
183 			}
184 			printf("Original message will be saved in dead.letter.\r\n");
185 			state = ESM_DEADLETTER;
186 			break;
187 
188 		  case ESM_MAIL:
189 			/*
190 			**  If mailing back, do it.
191 			**	Throw away all further output.  Don't alias,
192 			**	since this could cause loops, e.g., if joe
193 			**	mails to joe@x, and for some reason the network
194 			**	for @x is down, then the response gets sent to
195 			**	joe@x, which gives a response, etc.  Also force
196 			**	the mail to be delivered even if a version of
197 			**	it has already been sent to the sender.
198 			*/
199 
200 			if (strcmp(e->e_from.q_paddr, "<>") != 0)
201 				(void) sendtolist(e->e_from.q_paddr,
202 					  (ADDRESS *) NULL,
203 					  &e->e_errorqueue, e);
204 
205 			/* deliver a cc: to the postmaster if desired */
206 			if (PostMasterCopy != NULL)
207 			{
208 				auto ADDRESS *rlist = NULL;
209 
210 				(void) sendtolist(PostMasterCopy,
211 						  (ADDRESS *) NULL,
212 						  &rlist, e);
213 				(void) returntosender(e->e_message,
214 						      rlist, FALSE, e);
215 			}
216 			q = e->e_errorqueue;
217 			if (q == NULL)
218 			{
219 				/* this is an error-error */
220 				state = ESM_POSTMASTER;
221 				break;
222 			}
223 			if (returntosender(e->e_message,
224 					   q, (e->e_class >= 0), e) == 0)
225 			{
226 				state = ESM_DONE;
227 				break;
228 			}
229 
230 			/* didn't work -- return to postmaster */
231 			state = ESM_POSTMASTER;
232 			break;
233 
234 		  case ESM_POSTMASTER:
235 			/*
236 			**  Similar to previous case, but to system postmaster.
237 			*/
238 
239 			if (parseaddr("postmaster", q, 0, '\0', NULL, e) == NULL)
240 			{
241 				syserr("553 cannot parse postmaster!");
242 				ExitStat = EX_SOFTWARE;
243 				state = ESM_USRTMP;
244 				break;
245 			}
246 			if (returntosender(e->e_message,
247 					   q, (e->e_class >= 0), e) == 0)
248 			{
249 				state = ESM_DONE;
250 				break;
251 			}
252 
253 			/* didn't work -- last resort */
254 			state = ESM_USRTMP;
255 			break;
256 
257 		  case ESM_DEADLETTER:
258 			/*
259 			**  Save the message in dead.letter.
260 			**	If we weren't mailing back, and the user is
261 			**	local, we should save the message in
262 			**	~/dead.letter so that the poor person doesn't
263 			**	have to type it over again -- and we all know
264 			**	what poor typists UNIX users are.
265 			*/
266 
267 			p = NULL;
268 			if (e->e_from.q_mailer == LocalMailer)
269 			{
270 				if (e->e_from.q_home != NULL)
271 					p = e->e_from.q_home;
272 				else if ((pw = getpwnam(e->e_from.q_user)) != NULL)
273 					p = pw->pw_dir;
274 			}
275 			if (p == NULL)
276 			{
277 				/* no local directory */
278 				state = ESM_MAIL;
279 				break;
280 			}
281 			if (e->e_dfp != NULL)
282 			{
283 				auto ADDRESS *q;
284 				bool oldverb = Verbose;
285 
286 				/* we have a home directory; open dead.letter */
287 				define('z', p, e);
288 				expand("\201z/dead.letter", buf, &buf[sizeof buf - 1], e);
289 				Verbose = TRUE;
290 				message("Saving message in %s", buf);
291 				Verbose = oldverb;
292 				e->e_to = buf;
293 				q = NULL;
294 				(void) sendtolist(buf, &e->e_from, &q, e);
295 				if (deliver(e, q) == 0)
296 					state = ESM_DONE;
297 				else
298 					state = ESM_MAIL;
299 			}
300 			else
301 			{
302 				/* no data file -- try mailing back */
303 				state = ESM_MAIL;
304 			}
305 			break;
306 
307 		  case ESM_USRTMP:
308 			/*
309 			**  Log the mail in /usr/tmp/dead.letter.
310 			*/
311 
312 			if (e->e_class < 0)
313 			{
314 				state = ESM_DONE;
315 				break;
316 			}
317 
318 			fp = dfopen("/usr/tmp/dead.letter", "a");
319 			if (fp == NULL)
320 			{
321 				state = ESM_PANIC;
322 				break;
323 			}
324 
325 			putfromline(fp, FileMailer, e);
326 			(*e->e_puthdr)(fp, FileMailer, e);
327 			putline("\n", fp, FileMailer);
328 			(*e->e_putbody)(fp, FileMailer, e);
329 			putline("\n", fp, FileMailer);
330 			(void) fflush(fp);
331 			state = ferror(fp) ? ESM_PANIC : ESM_DONE;
332 			(void) xfclose(fp, "savemail", "/usr/tmp/dead.letter");
333 			break;
334 
335 		  default:
336 			syserr("554 savemail: unknown state %d", state);
337 
338 			/* fall through ... */
339 
340 		  case ESM_PANIC:
341 			/* leave the locked queue & transcript files around */
342 			syserr("554 savemail: cannot save rejected email anywhere");
343 			exit(EX_SOFTWARE);
344 		}
345 	}
346 }
347 /*
348 **  RETURNTOSENDER -- return a message to the sender with an error.
349 **
350 **	Parameters:
351 **		msg -- the explanatory message.
352 **		returnq -- the queue of people to send the message to.
353 **		sendbody -- if TRUE, also send back the body of the
354 **			message; otherwise just send the header.
355 **		e -- the current envelope.
356 **
357 **	Returns:
358 **		zero -- if everything went ok.
359 **		else -- some error.
360 **
361 **	Side Effects:
362 **		Returns the current message to the sender via
363 **		mail.
364 */
365 
366 static bool	SendBody;
367 
368 #define MAXRETURNS	6	/* max depth of returning messages */
369 #define ERRORFUDGE	100	/* nominal size of error message text */
370 
371 returntosender(msg, returnq, sendbody, e)
372 	char *msg;
373 	ADDRESS *returnq;
374 	bool sendbody;
375 	register ENVELOPE *e;
376 {
377 	char buf[MAXNAME];
378 	extern putheader(), errbody();
379 	register ENVELOPE *ee;
380 	ENVELOPE *oldcur = CurEnv;
381 	extern ENVELOPE *newenvelope();
382 	ENVELOPE errenvelope;
383 	static int returndepth;
384 	register ADDRESS *q;
385 
386 	if (msg == NULL)
387 		msg = "Unable to deliver mail";
388 
389 	if (tTd(6, 1))
390 	{
391 		printf("Return To Sender: msg=\"%s\", depth=%d, e=%x, returnq=",
392 		       msg, returndepth, e);
393 		printaddr(returnq, TRUE);
394 	}
395 
396 	if (++returndepth >= MAXRETURNS)
397 	{
398 		if (returndepth != MAXRETURNS)
399 			syserr("554 returntosender: infinite recursion on %s", returnq->q_paddr);
400 		/* don't "unrecurse" and fake a clean exit */
401 		/* returndepth--; */
402 		return (0);
403 	}
404 
405 	SendBody = sendbody;
406 	define('g', e->e_from.q_paddr, e);
407 	ee = newenvelope(&errenvelope, e);
408 	define('a', "\201b", ee);
409 	ee->e_puthdr = putheader;
410 	ee->e_putbody = errbody;
411 	ee->e_flags |= EF_RESPONSE;
412 	if (!bitset(EF_OLDSTYLE, e->e_flags))
413 		ee->e_flags &= ~EF_OLDSTYLE;
414 	ee->e_sendqueue = returnq;
415 	ee->e_msgsize = e->e_msgsize + ERRORFUDGE;
416 	openxscript(ee);
417 	for (q = returnq; q != NULL; q = q->q_next)
418 	{
419 		if (bitset(QDONTSEND, q->q_flags))
420 			continue;
421 
422 		ee->e_nrcpts++;
423 
424 		if (!DontPruneRoutes && pruneroute(q->q_paddr))
425 			parseaddr(q->q_paddr, q, 0, '\0', NULL, e);
426 
427 		if (q->q_alias == NULL)
428 			addheader("to", q->q_paddr, ee);
429 	}
430 
431 # ifdef LOG
432 	if (LogLevel > 5)
433 		syslog(LOG_INFO, "%s: %s: return to sender: %s",
434 			e->e_id, ee->e_id, msg);
435 # endif
436 
437 	(void) sprintf(buf, "Returned mail: %s", msg);
438 	addheader("subject", buf, ee);
439 
440 	/* fake up an address header for the from person */
441 	expand("\201n", buf, &buf[sizeof buf - 1], e);
442 	if (parseaddr(buf, &ee->e_from, 1, '\0', NULL, e) == NULL)
443 	{
444 		syserr("553 Can't parse myself!");
445 		ExitStat = EX_SOFTWARE;
446 		returndepth--;
447 		return (-1);
448 	}
449 	ee->e_sender = ee->e_from.q_paddr;
450 
451 	/* push state into submessage */
452 	CurEnv = ee;
453 	define('f', "\201n", ee);
454 	define('x', "Mail Delivery Subsystem", ee);
455 	eatheader(ee, TRUE);
456 
457 	/* actually deliver the error message */
458 	sendall(ee, SM_DEFAULT);
459 
460 	/* restore state */
461 	dropenvelope(ee);
462 	CurEnv = oldcur;
463 	returndepth--;
464 
465 	/* should check for delivery errors here */
466 	return (0);
467 }
468 /*
469 **  ERRBODY -- output the body of an error message.
470 **
471 **	Typically this is a copy of the transcript plus a copy of the
472 **	original offending message.
473 **
474 **	Parameters:
475 **		fp -- the output file.
476 **		m -- the mailer to output to.
477 **		e -- the envelope we are working in.
478 **
479 **	Returns:
480 **		none
481 **
482 **	Side Effects:
483 **		Outputs the body of an error message.
484 */
485 
486 errbody(fp, m, e)
487 	register FILE *fp;
488 	register struct mailer *m;
489 	register ENVELOPE *e;
490 {
491 	register FILE *xfile;
492 	char buf[MAXLINE];
493 	char *p;
494 
495 	if (e->e_parent == NULL)
496 	{
497 		syserr("errbody: null parent");
498 		putline("\n", fp, m);
499 		putline("   ----- Original message lost -----\n", fp, m);
500 		return;
501 	}
502 
503 	/*
504 	**  Output error message header (if specified and available).
505 	*/
506 
507 	if (ErrMsgFile != NULL)
508 	{
509 		if (*ErrMsgFile == '/')
510 		{
511 			xfile = fopen(ErrMsgFile, "r");
512 			if (xfile != NULL)
513 			{
514 				while (fgets(buf, sizeof buf, xfile) != NULL)
515 				{
516 					expand(buf, buf, &buf[sizeof buf - 1], e);
517 					putline(buf, fp, m);
518 				}
519 				(void) fclose(xfile);
520 				fprintf(fp, "\n");
521 			}
522 		}
523 		else
524 		{
525 			expand(ErrMsgFile, buf, &buf[sizeof buf - 1], e);
526 			putline(buf, fp, m);
527 			fprintf(fp, "\n");
528 		}
529 	}
530 
531 	/*
532 	**  Output transcript of errors
533 	*/
534 
535 	(void) fflush(stdout);
536 	p = queuename(e->e_parent, 'x');
537 	if ((xfile = fopen(p, "r")) == NULL)
538 	{
539 		syserr("Cannot open %s", p);
540 		putline("  ----- Transcript of session is unavailable -----\n", fp, m);
541 	}
542 	else
543 	{
544 		putline("   ----- Transcript of session follows -----\n", fp, m);
545 		if (e->e_xfp != NULL)
546 			(void) fflush(e->e_xfp);
547 		while (fgets(buf, sizeof buf, xfile) != NULL)
548 			putline(buf, fp, m);
549 		(void) xfclose(xfile, "errbody xscript", p);
550 	}
551 	errno = 0;
552 
553 	/*
554 	**  Output text of original message
555 	*/
556 
557 	if (NoReturn)
558 		SendBody = FALSE;
559 	if (e->e_parent->e_df != NULL)
560 	{
561 		if (SendBody)
562 		{
563 			putline("\n", fp, m);
564 			putline("   ----- Unsent message follows -----\n", fp, m);
565 			(void) fflush(fp);
566 			putheader(fp, m, e->e_parent);
567 			putline("\n", fp, m);
568 			putbody(fp, m, e->e_parent);
569 		}
570 		else
571 		{
572 			putline("\n", fp, m);
573 			putline("  ----- Message header follows -----\n", fp, m);
574 			(void) fflush(fp);
575 			putheader(fp, m, e->e_parent);
576 		}
577 	}
578 	else
579 	{
580 		putline("\n", fp, m);
581 		putline("  ----- No message was collected -----\n", fp, m);
582 		putline("\n", fp, m);
583 	}
584 
585 	/*
586 	**  Cleanup and exit
587 	*/
588 
589 	if (errno != 0)
590 		syserr("errbody: I/O error");
591 }
592 /*
593 **  PRUNEROUTE -- prune an RFC-822 source route
594 **
595 **	Trims down a source route to the last internet-registered hop.
596 **	This is encouraged by RFC 1123 section 5.3.3.
597 **
598 **	Parameters:
599 **		addr -- the address
600 **
601 **	Returns:
602 **		TRUE -- address was modified
603 **		FALSE -- address could not be pruned
604 **
605 **	Side Effects:
606 **		modifies addr in-place
607 */
608 
609 pruneroute(addr)
610 	char *addr;
611 {
612 #ifdef NAMED_BIND
613 	char *start, *at, *comma;
614 	char c;
615 	int rcode;
616 	char hostbuf[BUFSIZ];
617 	char *mxhosts[MAXMXHOSTS + 1];
618 
619 	/* check to see if this is really a route-addr */
620 	if (*addr != '<' || addr[1] != '@' || addr[strlen(addr) - 1] != '>')
621 		return FALSE;
622 	start = strchr(addr, ':');
623 	at = strrchr(addr, '@');
624 	if (start == NULL || at == NULL || at < start)
625 		return FALSE;
626 
627 	/* slice off the angle brackets */
628 	strcpy(hostbuf, at + 1);
629 	hostbuf[strlen(hostbuf) - 1] = '\0';
630 
631 	while (start)
632 	{
633 		if (getmxrr(hostbuf, mxhosts, "", &rcode) > 0)
634 		{
635 			strcpy(addr + 1, start + 1);
636 			return TRUE;
637 		}
638 		c = *start;
639 		*start = '\0';
640 		comma = strrchr(addr, ',');
641 		if (comma && comma[1] == '@')
642 			strcpy(hostbuf, comma + 2);
643 		else
644 			comma = 0;
645 		*start = c;
646 		start = comma;
647 	}
648 #endif
649 	return FALSE;
650 }
651