1 /*
2  * Copyright (c) 1983 Eric P. Allman
3  * Copyright (c) 1988 Regents of the University of California.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms are permitted
7  * provided that the above copyright notice and this paragraph are
8  * duplicated in all such forms and that any documentation,
9  * advertising materials, and other materials related to such
10  * distribution and use acknowledge that the software was developed
11  * by the University of California, Berkeley.  The name of the
12  * University may not be used to endorse or promote products derived
13  * from this software without specific prior written permission.
14  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
16  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
17  */
18 
19 #ifndef lint
20 static char sccsid[] = "@(#)savemail.c	5.9 (Berkeley) 06/30/88";
21 #endif /* not lint */
22 
23 # include <pwd.h>
24 # include "sendmail.h"
25 
26 /*
27 **  SAVEMAIL -- Save mail on error
28 **
29 **	If mailing back errors, mail it back to the originator
30 **	together with an error message; otherwise, just put it in
31 **	dead.letter in the user's home directory (if he exists on
32 **	this machine).
33 **
34 **	Parameters:
35 **		e -- the envelope containing the message in error.
36 **
37 **	Returns:
38 **		none
39 **
40 **	Side Effects:
41 **		Saves the letter, by writing or mailing it back to the
42 **		sender, or by putting it in dead.letter in her home
43 **		directory.
44 */
45 
46 /* defines for state machine */
47 # define ESM_REPORT	0	/* report to sender's terminal */
48 # define ESM_MAIL	1	/* mail back to sender */
49 # define ESM_QUIET	2	/* messages have already been returned */
50 # define ESM_DEADLETTER	3	/* save in ~/dead.letter */
51 # define ESM_POSTMASTER	4	/* return to postmaster */
52 # define ESM_USRTMP	5	/* save in /usr/tmp/dead.letter */
53 # define ESM_PANIC	6	/* leave the locked queue/transcript files */
54 # define ESM_DONE	7	/* the message is successfully delivered */
55 
56 
57 savemail(e)
58 	register ENVELOPE *e;
59 {
60 	register struct passwd *pw;
61 	register FILE *fp;
62 	int state;
63 	auto ADDRESS *q;
64 	char buf[MAXLINE+1];
65 	extern struct passwd *getpwnam();
66 	register char *p;
67 	extern char *ttypath();
68 	typedef int (*fnptr)();
69 
70 # ifdef DEBUG
71 	if (tTd(6, 1))
72 		printf("\nsavemail, ErrorMode = %c\n", ErrorMode);
73 # endif DEBUG
74 
75 	if (bitset(EF_RESPONSE, e->e_flags))
76 		return;
77 	if (e->e_class < 0)
78 	{
79 		message(Arpa_Info, "Dumping junk mail");
80 		return;
81 	}
82 	ForceMail = TRUE;
83 	e->e_flags &= ~EF_FATALERRS;
84 
85 	/*
86 	**  In the unhappy event we don't know who to return the mail
87 	**  to, make someone up.
88 	*/
89 
90 	if (e->e_from.q_paddr == NULL)
91 	{
92 		if (parseaddr("root", &e->e_from, 0, '\0') == NULL)
93 		{
94 			syserr("Cannot parse root!");
95 			ExitStat = EX_SOFTWARE;
96 			finis();
97 		}
98 	}
99 	e->e_to = NULL;
100 
101 	/*
102 	**  Basic state machine.
103 	**
104 	**	This machine runs through the following states:
105 	**
106 	**	ESM_QUIET	Errors have already been printed iff the
107 	**			sender is local.
108 	**	ESM_REPORT	Report directly to the sender's terminal.
109 	**	ESM_MAIL	Mail response to the sender.
110 	**	ESM_DEADLETTER	Save response in ~/dead.letter.
111 	**	ESM_POSTMASTER	Mail response to the postmaster.
112 	**	ESM_PANIC	Save response anywhere possible.
113 	*/
114 
115 	/* determine starting state */
116 	switch (ErrorMode)
117 	{
118 	  case EM_WRITE:
119 		state = ESM_REPORT;
120 		break;
121 
122 	  case EM_BERKNET:
123 		/* mail back, but return o.k. exit status */
124 		ExitStat = EX_OK;
125 
126 		/* fall through.... */
127 
128 	  case EM_MAIL:
129 		state = ESM_MAIL;
130 		break;
131 
132 	  case EM_PRINT:
133 	  case '\0':
134 		state = ESM_QUIET;
135 		break;
136 
137 	  case EM_QUIET:
138 		/* no need to return anything at all */
139 		return;
140 
141 	  default:
142 		syserr("savemail: ErrorMode x%x\n");
143 		state = ESM_MAIL;
144 		break;
145 	}
146 
147 	while (state != ESM_DONE)
148 	{
149 # ifdef DEBUG
150 		if (tTd(6, 5))
151 			printf("  state %d\n", state);
152 # endif DEBUG
153 
154 		switch (state)
155 		{
156 		  case ESM_QUIET:
157 			if (e->e_from.q_mailer == LocalMailer)
158 				state = ESM_DEADLETTER;
159 			else
160 				state = ESM_MAIL;
161 			break;
162 
163 		  case ESM_REPORT:
164 
165 			/*
166 			**  If the user is still logged in on the same terminal,
167 			**  then write the error messages back to hir (sic).
168 			*/
169 
170 			p = ttypath();
171 			if (p == NULL || freopen(p, "w", stdout) == NULL)
172 			{
173 				state = ESM_MAIL;
174 				break;
175 			}
176 
177 			expand("\001n", buf, &buf[sizeof buf - 1], e);
178 			printf("\r\nMessage from %s...\r\n", buf);
179 			printf("Errors occurred while sending mail.\r\n");
180 			if (e->e_xfp != NULL)
181 			{
182 				(void) fflush(e->e_xfp);
183 				fp = fopen(queuename(e, 'x'), "r");
184 			}
185 			else
186 				fp = NULL;
187 			if (fp == NULL)
188 			{
189 				syserr("Cannot open %s", queuename(e, 'x'));
190 				printf("Transcript of session is unavailable.\r\n");
191 			}
192 			else
193 			{
194 				printf("Transcript follows:\r\n");
195 				while (fgets(buf, sizeof buf, fp) != NULL &&
196 				       !ferror(stdout))
197 					fputs(buf, stdout);
198 				(void) fclose(fp);
199 			}
200 			printf("Original message will be saved in dead.letter.\r\n");
201 			if (ferror(stdout))
202 				(void) syserr("savemail: stdout: write err");
203 			state = ESM_DEADLETTER;
204 			break;
205 
206 		  case ESM_MAIL:
207 		  case ESM_POSTMASTER:
208 			/*
209 			**  If mailing back, do it.
210 			**	Throw away all further output.  Don't alias,
211 			**	since this could cause loops, e.g., if joe
212 			**	mails to joe@x, and for some reason the network
213 			**	for @x is down, then the response gets sent to
214 			**	joe@x, which gives a response, etc.  Also force
215 			**	the mail to be delivered even if a version of
216 			**	it has already been sent to the sender.
217 			*/
218 
219 			if (state == ESM_MAIL)
220 			{
221 				if (e->e_errorqueue == NULL)
222 					sendtolist(e->e_from.q_paddr,
223 						(ADDRESS *) NULL,
224 						&e->e_errorqueue);
225 
226 				/* deliver a cc: to the postmaster if desired */
227 				if (PostMasterCopy != NULL)
228 					sendtolist(PostMasterCopy,
229 						(ADDRESS *) NULL,
230 						&e->e_errorqueue);
231 				q = e->e_errorqueue;
232 			}
233 			else
234 			{
235 				if (parseaddr("postmaster", q, 0, '\0') == NULL)
236 				{
237 					syserr("cannot parse postmaster!");
238 					ExitStat = EX_SOFTWARE;
239 					state = ESM_USRTMP;
240 					break;
241 				}
242 			}
243 			if (returntosender(e->e_message != NULL ? e->e_message :
244 					   "Unable to deliver mail",
245 					   q, TRUE) == 0)
246 			{
247 				state = ESM_DONE;
248 				break;
249 			}
250 
251 			state = state == ESM_MAIL ? ESM_POSTMASTER : ESM_USRTMP;
252 			break;
253 
254 		  case ESM_DEADLETTER:
255 			/*
256 			**  Save the message in dead.letter.
257 			**	If we weren't mailing back, and the user is
258 			**	local, we should save the message in
259 			**	~/dead.letter so that the poor person doesn't
260 			**	have to type it over again -- and we all know
261 			**	what poor typists UNIX users are.
262 			*/
263 
264 			p = NULL;
265 			if (e->e_from.q_mailer == LocalMailer)
266 			{
267 				if (e->e_from.q_home != NULL)
268 					p = e->e_from.q_home;
269 				else if ((pw = getpwnam(e->e_from.q_user)) != NULL)
270 					p = pw->pw_dir;
271 			}
272 			if (p == NULL)
273 			{
274 				syserr("Can't return mail to %s", e->e_from.q_paddr);
275 				state = ESM_MAIL;
276 				break;
277 			}
278 			if (e->e_dfp != NULL)
279 			{
280 				auto ADDRESS *q;
281 				bool oldverb = Verbose;
282 
283 				/* we have a home directory; open dead.letter */
284 				define('z', p, e);
285 				expand("\001z/dead.letter", buf, &buf[sizeof buf - 1], e);
286 				Verbose = TRUE;
287 				message(Arpa_Info, "Saving message in %s", buf);
288 				Verbose = oldverb;
289 				e->e_to = buf;
290 				q = NULL;
291 				sendtolist(buf, (ADDRESS *) NULL, &q);
292 				if (deliver(e, q) == 0)
293 					state = ESM_DONE;
294 				else
295 					state = ESM_MAIL;
296 			}
297 			else
298 			{
299 				/* no data file -- try mailing back */
300 				state = ESM_MAIL;
301 			}
302 			break;
303 
304 		  case ESM_USRTMP:
305 			/*
306 			**  Log the mail in /usr/tmp/dead.letter.
307 			*/
308 
309 			fp = dfopen("/usr/tmp/dead.letter", "a");
310 			if (fp == NULL)
311 			{
312 				state = ESM_PANIC;
313 				break;
314 			}
315 
316 			putfromline(fp, ProgMailer);
317 			(*e->e_puthdr)(fp, ProgMailer, e);
318 			putline("\n", fp, ProgMailer);
319 			(*e->e_putbody)(fp, ProgMailer, e);
320 			putline("\n", fp, ProgMailer);
321 			(void) fflush(fp);
322 			state = ferror(fp) ? ESM_PANIC : ESM_DONE;
323 			(void) fclose(fp);
324 			break;
325 
326 		  default:
327 			syserr("savemail: unknown state %d", state);
328 
329 			/* fall through ... */
330 
331 		  case ESM_PANIC:
332 			syserr("savemail: HELP!!!!");
333 # ifdef LOG
334 			if (LogLevel >= 1)
335 				syslog(LOG_ALERT, "savemail: HELP!!!!");
336 # endif LOG
337 
338 			/* leave the locked queue & transcript files around */
339 			exit(EX_SOFTWARE);
340 		}
341 	}
342 }
343 /*
344 **  RETURNTOSENDER -- return a message to the sender with an error.
345 **
346 **	Parameters:
347 **		msg -- the explanatory message.
348 **		returnq -- the queue of people to send the message to.
349 **		sendbody -- if TRUE, also send back the body of the
350 **			message; otherwise just send the header.
351 **
352 **	Returns:
353 **		zero -- if everything went ok.
354 **		else -- some error.
355 **
356 **	Side Effects:
357 **		Returns the current message to the sender via
358 **		mail.
359 */
360 
361 static bool	SendBody;
362 
363 #define MAXRETURNS	6	/* max depth of returning messages */
364 
365 returntosender(msg, returnq, sendbody)
366 	char *msg;
367 	ADDRESS *returnq;
368 	bool sendbody;
369 {
370 	char buf[MAXNAME];
371 	extern putheader(), errbody();
372 	register ENVELOPE *ee;
373 	extern ENVELOPE *newenvelope();
374 	ENVELOPE errenvelope;
375 	static int returndepth;
376 	register ADDRESS *q;
377 
378 # ifdef DEBUG
379 	if (tTd(6, 1))
380 	{
381 		printf("Return To Sender: msg=\"%s\", depth=%d, CurEnv=%x,\n",
382 		       msg, returndepth, CurEnv);
383 		printf("\treturnq=");
384 		printaddr(returnq, TRUE);
385 	}
386 # endif DEBUG
387 
388 	if (++returndepth >= MAXRETURNS)
389 	{
390 		if (returndepth != MAXRETURNS)
391 			syserr("returntosender: infinite recursion on %s", returnq->q_paddr);
392 		/* don't "unrecurse" and fake a clean exit */
393 		/* returndepth--; */
394 		return (0);
395 	}
396 
397 	SendBody = sendbody;
398 	define('g', "\001f", CurEnv);
399 	ee = newenvelope(&errenvelope);
400 	define('a', "\001b", ee);
401 	ee->e_puthdr = putheader;
402 	ee->e_putbody = errbody;
403 	ee->e_flags |= EF_RESPONSE;
404 	ee->e_sendqueue = returnq;
405 	openxscript(ee);
406 	for (q = returnq; q != NULL; q = q->q_next)
407 	{
408 		if (q->q_alias == NULL)
409 			addheader("to", q->q_paddr, ee);
410 	}
411 
412 	(void) sprintf(buf, "Returned mail: %s", msg);
413 	addheader("subject", buf, ee);
414 
415 	/* fake up an address header for the from person */
416 	expand("\001n", buf, &buf[sizeof buf - 1], CurEnv);
417 	if (parseaddr(buf, &ee->e_from, -1, '\0') == NULL)
418 	{
419 		syserr("Can't parse myself!");
420 		ExitStat = EX_SOFTWARE;
421 		returndepth--;
422 		return (-1);
423 	}
424 	loweraddr(&ee->e_from);
425 
426 	/* push state into submessage */
427 	CurEnv = ee;
428 	define('f', "\001n", ee);
429 	define('x', "Mail Delivery Subsystem", ee);
430 	eatheader(ee);
431 
432 	/* actually deliver the error message */
433 	sendall(ee, SM_DEFAULT);
434 
435 	/* restore state */
436 	dropenvelope(ee);
437 	CurEnv = CurEnv->e_parent;
438 	returndepth--;
439 
440 	/* should check for delivery errors here */
441 	return (0);
442 }
443 /*
444 **  ERRBODY -- output the body of an error message.
445 **
446 **	Typically this is a copy of the transcript plus a copy of the
447 **	original offending message.
448 **
449 **	Parameters:
450 **		fp -- the output file.
451 **		m -- the mailer to output to.
452 **		e -- the envelope we are working in.
453 **
454 **	Returns:
455 **		none
456 **
457 **	Side Effects:
458 **		Outputs the body of an error message.
459 */
460 
461 errbody(fp, m, e)
462 	register FILE *fp;
463 	register struct mailer *m;
464 	register ENVELOPE *e;
465 {
466 	register FILE *xfile;
467 	char buf[MAXLINE];
468 	char *p;
469 
470 	/*
471 	**  Output transcript of errors
472 	*/
473 
474 	(void) fflush(stdout);
475 	p = queuename(e->e_parent, 'x');
476 	if ((xfile = fopen(p, "r")) == NULL)
477 	{
478 		syserr("Cannot open %s", p);
479 		fprintf(fp, "  ----- Transcript of session is unavailable -----\n");
480 	}
481 	else
482 	{
483 		fprintf(fp, "   ----- Transcript of session follows -----\n");
484 		if (e->e_xfp != NULL)
485 			(void) fflush(e->e_xfp);
486 		while (fgets(buf, sizeof buf, xfile) != NULL)
487 			putline(buf, fp, m);
488 		(void) fclose(xfile);
489 	}
490 	errno = 0;
491 
492 	/*
493 	**  Output text of original message
494 	*/
495 
496 	if (NoReturn)
497 		fprintf(fp, "\n   ----- Return message suppressed -----\n\n");
498 	else if (e->e_parent->e_dfp != NULL)
499 	{
500 		if (SendBody)
501 		{
502 			putline("\n", fp, m);
503 			putline("   ----- Unsent message follows -----\n", fp, m);
504 			(void) fflush(fp);
505 			putheader(fp, m, e->e_parent);
506 			putline("\n", fp, m);
507 			putbody(fp, m, e->e_parent);
508 		}
509 		else
510 		{
511 			putline("\n", fp, m);
512 			putline("  ----- Message header follows -----\n", fp, m);
513 			(void) fflush(fp);
514 			putheader(fp, m, e->e_parent);
515 		}
516 	}
517 	else
518 	{
519 		putline("\n", fp, m);
520 		putline("  ----- No message was collected -----\n", fp, m);
521 		putline("\n", fp, m);
522 	}
523 
524 	/*
525 	**  Cleanup and exit
526 	*/
527 
528 	if (errno != 0)
529 		syserr("errbody: I/O error");
530 }
531