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	5.11 (Berkeley) 01/01/89";
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 	if (tTd(6, 1))
71 		printf("\nsavemail, ErrorMode = %c\n", ErrorMode);
72 
73 	if (bitset(EF_RESPONSE, e->e_flags))
74 		return;
75 	if (e->e_class < 0)
76 	{
77 		message(Arpa_Info, "Dumping junk mail");
78 		return;
79 	}
80 	ForceMail = TRUE;
81 	e->e_flags &= ~EF_FATALERRS;
82 
83 	/*
84 	**  In the unhappy event we don't know who to return the mail
85 	**  to, make someone up.
86 	*/
87 
88 	if (e->e_from.q_paddr == NULL)
89 	{
90 		if (parseaddr("root", &e->e_from, 0, '\0') == NULL)
91 		{
92 			syserr("Cannot parse root!");
93 			ExitStat = EX_SOFTWARE;
94 			finis();
95 		}
96 	}
97 	e->e_to = NULL;
98 
99 	/*
100 	**  Basic state machine.
101 	**
102 	**	This machine runs through the following states:
103 	**
104 	**	ESM_QUIET	Errors have already been printed iff the
105 	**			sender is local.
106 	**	ESM_REPORT	Report directly to the sender's terminal.
107 	**	ESM_MAIL	Mail response to the sender.
108 	**	ESM_DEADLETTER	Save response in ~/dead.letter.
109 	**	ESM_POSTMASTER	Mail response to the postmaster.
110 	**	ESM_PANIC	Save response anywhere possible.
111 	*/
112 
113 	/* determine starting state */
114 	switch (ErrorMode)
115 	{
116 	  case EM_WRITE:
117 		state = ESM_REPORT;
118 		break;
119 
120 	  case EM_BERKNET:
121 		/* mail back, but return o.k. exit status */
122 		ExitStat = EX_OK;
123 
124 		/* fall through.... */
125 
126 	  case EM_MAIL:
127 		state = ESM_MAIL;
128 		break;
129 
130 	  case EM_PRINT:
131 	  case '\0':
132 		state = ESM_QUIET;
133 		break;
134 
135 	  case EM_QUIET:
136 		/* no need to return anything at all */
137 		return;
138 
139 	  default:
140 		syserr("savemail: ErrorMode x%x\n");
141 		state = ESM_MAIL;
142 		break;
143 	}
144 
145 	while (state != ESM_DONE)
146 	{
147 		if (tTd(6, 5))
148 			printf("  state %d\n", state);
149 
150 		switch (state)
151 		{
152 		  case ESM_QUIET:
153 			if (e->e_from.q_mailer == LocalMailer)
154 				state = ESM_DEADLETTER;
155 			else
156 				state = ESM_MAIL;
157 			break;
158 
159 		  case ESM_REPORT:
160 
161 			/*
162 			**  If the user is still logged in on the same terminal,
163 			**  then write the error messages back to hir (sic).
164 			*/
165 
166 			p = ttypath();
167 			if (p == NULL || freopen(p, "w", stdout) == NULL)
168 			{
169 				state = ESM_MAIL;
170 				break;
171 			}
172 
173 			expand("\001n", buf, &buf[sizeof buf - 1], e);
174 			printf("\r\nMessage from %s...\r\n", buf);
175 			printf("Errors occurred while sending mail.\r\n");
176 			if (e->e_xfp != NULL)
177 			{
178 				(void) fflush(e->e_xfp);
179 				fp = fopen(queuename(e, 'x'), "r");
180 			}
181 			else
182 				fp = NULL;
183 			if (fp == NULL)
184 			{
185 				syserr("Cannot open %s", queuename(e, 'x'));
186 				printf("Transcript of session is unavailable.\r\n");
187 			}
188 			else
189 			{
190 				printf("Transcript follows:\r\n");
191 				while (fgets(buf, sizeof buf, fp) != NULL &&
192 				       !ferror(stdout))
193 					fputs(buf, stdout);
194 				(void) fclose(fp);
195 			}
196 			printf("Original message will be saved in dead.letter.\r\n");
197 			state = ESM_DEADLETTER;
198 			break;
199 
200 		  case ESM_MAIL:
201 		  case ESM_POSTMASTER:
202 			/*
203 			**  If mailing back, do it.
204 			**	Throw away all further output.  Don't alias,
205 			**	since this could cause loops, e.g., if joe
206 			**	mails to joe@x, and for some reason the network
207 			**	for @x is down, then the response gets sent to
208 			**	joe@x, which gives a response, etc.  Also force
209 			**	the mail to be delivered even if a version of
210 			**	it has already been sent to the sender.
211 			*/
212 
213 			if (state == ESM_MAIL)
214 			{
215 				if (e->e_errorqueue == NULL)
216 					sendtolist(e->e_from.q_paddr,
217 						(ADDRESS *) NULL,
218 						&e->e_errorqueue);
219 
220 				/* deliver a cc: to the postmaster if desired */
221 				if (PostMasterCopy != NULL)
222 					sendtolist(PostMasterCopy,
223 						(ADDRESS *) NULL,
224 						&e->e_errorqueue);
225 				q = e->e_errorqueue;
226 			}
227 			else
228 			{
229 				if (parseaddr("postmaster", q, 0, '\0') == NULL)
230 				{
231 					syserr("cannot parse postmaster!");
232 					ExitStat = EX_SOFTWARE;
233 					state = ESM_USRTMP;
234 					break;
235 				}
236 			}
237 			if (returntosender(e->e_message != NULL ? e->e_message :
238 					   "Unable to deliver mail",
239 					   q, TRUE) == 0)
240 			{
241 				state = ESM_DONE;
242 				break;
243 			}
244 
245 			state = state == ESM_MAIL ? ESM_POSTMASTER : ESM_USRTMP;
246 			break;
247 
248 		  case ESM_DEADLETTER:
249 			/*
250 			**  Save the message in dead.letter.
251 			**	If we weren't mailing back, and the user is
252 			**	local, we should save the message in
253 			**	~/dead.letter so that the poor person doesn't
254 			**	have to type it over again -- and we all know
255 			**	what poor typists UNIX users are.
256 			*/
257 
258 			p = NULL;
259 			if (e->e_from.q_mailer == LocalMailer)
260 			{
261 				if (e->e_from.q_home != NULL)
262 					p = e->e_from.q_home;
263 				else if ((pw = getpwnam(e->e_from.q_user)) != NULL)
264 					p = pw->pw_dir;
265 			}
266 			if (p == NULL)
267 			{
268 				syserr("Can't return mail to %s", e->e_from.q_paddr);
269 				state = ESM_MAIL;
270 				break;
271 			}
272 			if (e->e_dfp != NULL)
273 			{
274 				auto ADDRESS *q;
275 				bool oldverb = Verbose;
276 
277 				/* we have a home directory; open dead.letter */
278 				define('z', p, e);
279 				expand("\001z/dead.letter", buf, &buf[sizeof buf - 1], e);
280 				Verbose = TRUE;
281 				message(Arpa_Info, "Saving message in %s", buf);
282 				Verbose = oldverb;
283 				e->e_to = buf;
284 				q = NULL;
285 				sendtolist(buf, (ADDRESS *) NULL, &q);
286 				if (deliver(e, q) == 0)
287 					state = ESM_DONE;
288 				else
289 					state = ESM_MAIL;
290 			}
291 			else
292 			{
293 				/* no data file -- try mailing back */
294 				state = ESM_MAIL;
295 			}
296 			break;
297 
298 		  case ESM_USRTMP:
299 			/*
300 			**  Log the mail in /usr/tmp/dead.letter.
301 			*/
302 
303 			fp = dfopen("/usr/tmp/dead.letter", "a");
304 			if (fp == NULL)
305 			{
306 				state = ESM_PANIC;
307 				break;
308 			}
309 
310 			putfromline(fp, ProgMailer);
311 			(*e->e_puthdr)(fp, ProgMailer, e);
312 			putline("\n", fp, ProgMailer);
313 			(*e->e_putbody)(fp, ProgMailer, e);
314 			putline("\n", fp, ProgMailer);
315 			(void) fflush(fp);
316 			state = ferror(fp) ? ESM_PANIC : ESM_DONE;
317 			(void) fclose(fp);
318 			break;
319 
320 		  default:
321 			syserr("savemail: unknown state %d", state);
322 
323 			/* fall through ... */
324 
325 		  case ESM_PANIC:
326 			syserr("savemail: HELP!!!!");
327 # ifdef LOG
328 			if (LogLevel >= 1)
329 				syslog(LOG_ALERT, "savemail: HELP!!!!");
330 # endif LOG
331 
332 			/* leave the locked queue & transcript files around */
333 			exit(EX_SOFTWARE);
334 		}
335 	}
336 }
337 /*
338 **  RETURNTOSENDER -- return a message to the sender with an error.
339 **
340 **	Parameters:
341 **		msg -- the explanatory message.
342 **		returnq -- the queue of people to send the message to.
343 **		sendbody -- if TRUE, also send back the body of the
344 **			message; otherwise just send the header.
345 **
346 **	Returns:
347 **		zero -- if everything went ok.
348 **		else -- some error.
349 **
350 **	Side Effects:
351 **		Returns the current message to the sender via
352 **		mail.
353 */
354 
355 static bool	SendBody;
356 
357 #define MAXRETURNS	6	/* max depth of returning messages */
358 
359 returntosender(msg, returnq, sendbody)
360 	char *msg;
361 	ADDRESS *returnq;
362 	bool sendbody;
363 {
364 	char buf[MAXNAME];
365 	extern putheader(), errbody();
366 	register ENVELOPE *ee;
367 	extern ENVELOPE *newenvelope();
368 	ENVELOPE errenvelope;
369 	static int returndepth;
370 	register ADDRESS *q;
371 
372 	if (tTd(6, 1))
373 	{
374 		printf("Return To Sender: msg=\"%s\", depth=%d, CurEnv=%x,\n",
375 		       msg, returndepth, CurEnv);
376 		printf("\treturnq=");
377 		printaddr(returnq, TRUE);
378 	}
379 
380 	if (++returndepth >= MAXRETURNS)
381 	{
382 		if (returndepth != MAXRETURNS)
383 			syserr("returntosender: infinite recursion on %s", returnq->q_paddr);
384 		/* don't "unrecurse" and fake a clean exit */
385 		/* returndepth--; */
386 		return (0);
387 	}
388 
389 	SendBody = sendbody;
390 	define('g', "\001f", CurEnv);
391 	ee = newenvelope(&errenvelope);
392 	define('a', "\001b", ee);
393 	ee->e_puthdr = putheader;
394 	ee->e_putbody = errbody;
395 	ee->e_flags |= EF_RESPONSE;
396 	ee->e_sendqueue = returnq;
397 	openxscript(ee);
398 	for (q = returnq; q != NULL; q = q->q_next)
399 	{
400 		if (q->q_alias == NULL)
401 			addheader("to", q->q_paddr, ee);
402 	}
403 
404 	(void) sprintf(buf, "Returned mail: %s", msg);
405 	addheader("subject", buf, ee);
406 
407 	/* fake up an address header for the from person */
408 	expand("\001n", buf, &buf[sizeof buf - 1], CurEnv);
409 	if (parseaddr(buf, &ee->e_from, -1, '\0') == NULL)
410 	{
411 		syserr("Can't parse myself!");
412 		ExitStat = EX_SOFTWARE;
413 		returndepth--;
414 		return (-1);
415 	}
416 	loweraddr(&ee->e_from);
417 
418 	/* push state into submessage */
419 	CurEnv = ee;
420 	define('f', "\001n", ee);
421 	define('x', "Mail Delivery Subsystem", ee);
422 	eatheader(ee);
423 
424 	/* actually deliver the error message */
425 	sendall(ee, SM_DEFAULT);
426 
427 	/* restore state */
428 	dropenvelope(ee);
429 	CurEnv = CurEnv->e_parent;
430 	returndepth--;
431 
432 	/* should check for delivery errors here */
433 	return (0);
434 }
435 /*
436 **  ERRBODY -- output the body of an error message.
437 **
438 **	Typically this is a copy of the transcript plus a copy of the
439 **	original offending message.
440 **
441 **	Parameters:
442 **		fp -- the output file.
443 **		m -- the mailer to output to.
444 **		e -- the envelope we are working in.
445 **
446 **	Returns:
447 **		none
448 **
449 **	Side Effects:
450 **		Outputs the body of an error message.
451 */
452 
453 errbody(fp, m, e)
454 	register FILE *fp;
455 	register struct mailer *m;
456 	register ENVELOPE *e;
457 {
458 	register FILE *xfile;
459 	char buf[MAXLINE];
460 	char *p;
461 
462 	/*
463 	**  Output transcript of errors
464 	*/
465 
466 	(void) fflush(stdout);
467 	p = queuename(e->e_parent, 'x');
468 	if ((xfile = fopen(p, "r")) == NULL)
469 	{
470 		syserr("Cannot open %s", p);
471 		fprintf(fp, "  ----- Transcript of session is unavailable -----\n");
472 	}
473 	else
474 	{
475 		fprintf(fp, "   ----- Transcript of session follows -----\n");
476 		if (e->e_xfp != NULL)
477 			(void) fflush(e->e_xfp);
478 		while (fgets(buf, sizeof buf, xfile) != NULL)
479 			putline(buf, fp, m);
480 		(void) fclose(xfile);
481 	}
482 	errno = 0;
483 
484 	/*
485 	**  Output text of original message
486 	*/
487 
488 	if (NoReturn)
489 		fprintf(fp, "\n   ----- Return message suppressed -----\n\n");
490 	else if (e->e_parent->e_dfp != NULL)
491 	{
492 		if (SendBody)
493 		{
494 			putline("\n", fp, m);
495 			putline("   ----- Unsent message follows -----\n", fp, m);
496 			(void) fflush(fp);
497 			putheader(fp, m, e->e_parent);
498 			putline("\n", fp, m);
499 			putbody(fp, m, e->e_parent);
500 		}
501 		else
502 		{
503 			putline("\n", fp, m);
504 			putline("  ----- Message header follows -----\n", fp, m);
505 			(void) fflush(fp);
506 			putheader(fp, m, e->e_parent);
507 		}
508 	}
509 	else
510 	{
511 		putline("\n", fp, m);
512 		putline("  ----- No message was collected -----\n", fp, m);
513 		putline("\n", fp, m);
514 	}
515 
516 	/*
517 	**  Cleanup and exit
518 	*/
519 
520 	if (errno != 0)
521 		syserr("errbody: I/O error");
522 }
523