1 /*
2 **  Sendmail
3 **  Copyright (c) 1983  Eric P. Allman
4 **  Berkeley, California
5 **
6 **  Copyright (c) 1983 Regents of the University of California.
7 **  All rights reserved.  The Berkeley software License Agreement
8 **  specifies the terms and conditions for redistribution.
9 */
10 
11 #ifndef lint
12 static char	SccsId[] = "@(#)savemail.c	5.7 (Berkeley) 12/07/85";
13 #endif not lint
14 
15 # include <pwd.h>
16 # include "sendmail.h"
17 
18 /*
19 **  SAVEMAIL -- Save mail on error
20 **
21 **	If mailing back errors, mail it back to the originator
22 **	together with an error message; otherwise, just put it in
23 **	dead.letter in the user's home directory (if he exists on
24 **	this machine).
25 **
26 **	Parameters:
27 **		e -- the envelope containing the message in error.
28 **
29 **	Returns:
30 **		none
31 **
32 **	Side Effects:
33 **		Saves the letter, by writing or mailing it back to the
34 **		sender, or by putting it in dead.letter in her home
35 **		directory.
36 */
37 
38 /* defines for state machine */
39 # define ESM_REPORT	0	/* report to sender's terminal */
40 # define ESM_MAIL	1	/* mail back to sender */
41 # define ESM_QUIET	2	/* messages have already been returned */
42 # define ESM_DEADLETTER	3	/* save in ~/dead.letter */
43 # define ESM_POSTMASTER	4	/* return to postmaster */
44 # define ESM_USRTMP	5	/* save in /usr/tmp/dead.letter */
45 # define ESM_PANIC	6	/* leave the locked queue/transcript files */
46 # define ESM_DONE	7	/* the message is successfully delivered */
47 
48 
49 savemail(e)
50 	register ENVELOPE *e;
51 {
52 	register struct passwd *pw;
53 	register FILE *fp;
54 	int state;
55 	auto ADDRESS *q;
56 	char buf[MAXLINE+1];
57 	extern struct passwd *getpwnam();
58 	register char *p;
59 	extern char *ttypath();
60 	typedef int (*fnptr)();
61 
62 # ifdef DEBUG
63 	if (tTd(6, 1))
64 		printf("\nsavemail, ErrorMode = %c\n", ErrorMode);
65 # endif DEBUG
66 
67 	if (bitset(EF_RESPONSE, e->e_flags))
68 		return;
69 	if (e->e_class < 0)
70 	{
71 		message(Arpa_Info, "Dumping junk mail");
72 		return;
73 	}
74 	ForceMail = TRUE;
75 	e->e_flags &= ~EF_FATALERRS;
76 
77 	/*
78 	**  In the unhappy event we don't know who to return the mail
79 	**  to, make someone up.
80 	*/
81 
82 	if (e->e_from.q_paddr == NULL)
83 	{
84 		if (parseaddr("root", &e->e_from, 0, '\0') == NULL)
85 		{
86 			syserr("Cannot parse root!");
87 			ExitStat = EX_SOFTWARE;
88 			finis();
89 		}
90 	}
91 	e->e_to = NULL;
92 
93 	/*
94 	**  Basic state machine.
95 	**
96 	**	This machine runs through the following states:
97 	**
98 	**	ESM_QUIET	Errors have already been printed iff the
99 	**			sender is local.
100 	**	ESM_REPORT	Report directly to the sender's terminal.
101 	**	ESM_MAIL	Mail response to the sender.
102 	**	ESM_DEADLETTER	Save response in ~/dead.letter.
103 	**	ESM_POSTMASTER	Mail response to the postmaster.
104 	**	ESM_PANIC	Save response anywhere possible.
105 	*/
106 
107 	/* determine starting state */
108 	switch (ErrorMode)
109 	{
110 	  case EM_WRITE:
111 		state = ESM_REPORT;
112 		break;
113 
114 	  case EM_BERKNET:
115 		/* mail back, but return o.k. exit status */
116 		ExitStat = EX_OK;
117 
118 		/* fall through.... */
119 
120 	  case EM_MAIL:
121 		state = ESM_MAIL;
122 		break;
123 
124 	  case EM_PRINT:
125 	  case '\0':
126 		state = ESM_QUIET;
127 		break;
128 
129 	  case EM_QUIET:
130 		/* no need to return anything at all */
131 		return;
132 
133 	  default:
134 		syserr("savemail: ErrorMode x%x\n");
135 		state = ESM_MAIL;
136 		break;
137 	}
138 
139 	while (state != ESM_DONE)
140 	{
141 # ifdef DEBUG
142 		if (tTd(6, 5))
143 			printf("  state %d\n", state);
144 # endif DEBUG
145 
146 		switch (state)
147 		{
148 		  case ESM_QUIET:
149 			if (e->e_from.q_mailer == LocalMailer)
150 				state = ESM_DEADLETTER;
151 			else
152 				state = ESM_MAIL;
153 			break;
154 
155 		  case ESM_REPORT:
156 
157 			/*
158 			**  If the user is still logged in on the same terminal,
159 			**  then write the error messages back to hir (sic).
160 			*/
161 
162 			p = ttypath();
163 			if (p == NULL || freopen(p, "w", stdout) == NULL)
164 			{
165 				state = ESM_MAIL;
166 				break;
167 			}
168 
169 			expand("\001n", buf, &buf[sizeof buf - 1], e);
170 			printf("\r\nMessage from %s...\r\n", buf);
171 			printf("Errors occurred while sending mail.\r\n");
172 			if (e->e_xfp != NULL)
173 			{
174 				(void) fflush(e->e_xfp);
175 				fp = fopen(queuename(e, 'x'), "r");
176 			}
177 			else
178 				fp = NULL;
179 			if (fp == NULL)
180 			{
181 				syserr("Cannot open %s", queuename(e, 'x'));
182 				printf("Transcript of session is unavailable.\r\n");
183 			}
184 			else
185 			{
186 				printf("Transcript follows:\r\n");
187 				while (fgets(buf, sizeof buf, fp) != NULL &&
188 				       !ferror(stdout))
189 					fputs(buf, stdout);
190 				(void) fclose(fp);
191 			}
192 			printf("Original message will be saved in dead.letter.\r\n");
193 			if (ferror(stdout))
194 				(void) syserr("savemail: stdout: write err");
195 			state = ESM_DEADLETTER;
196 			break;
197 
198 		  case ESM_MAIL:
199 		  case ESM_POSTMASTER:
200 			/*
201 			**  If mailing back, do it.
202 			**	Throw away all further output.  Don't alias,
203 			**	since this could cause loops, e.g., if joe
204 			**	mails to joe@x, and for some reason the network
205 			**	for @x is down, then the response gets sent to
206 			**	joe@x, which gives a response, etc.  Also force
207 			**	the mail to be delivered even if a version of
208 			**	it has already been sent to the sender.
209 			*/
210 
211 			if (state == ESM_MAIL)
212 			{
213 				if (e->e_errorqueue == NULL)
214 					sendtolist(e->e_from.q_paddr,
215 						(ADDRESS *) NULL,
216 						&e->e_errorqueue);
217 
218 				/* deliver a cc: to the postmaster if desired */
219 				if (PostMasterCopy != NULL)
220 					sendtolist(PostMasterCopy,
221 						(ADDRESS *) NULL,
222 						&e->e_errorqueue);
223 				q = e->e_errorqueue;
224 			}
225 			else
226 			{
227 				if (parseaddr("postmaster", q, 0, '\0') == NULL)
228 				{
229 					syserr("cannot parse postmaster!");
230 					ExitStat = EX_SOFTWARE;
231 					state = ESM_USRTMP;
232 					break;
233 				}
234 			}
235 			if (returntosender(e->e_message != NULL ? e->e_message :
236 					   "Unable to deliver mail",
237 					   q, TRUE) == 0)
238 			{
239 				state = ESM_DONE;
240 				break;
241 			}
242 
243 			state = state == ESM_MAIL ? ESM_POSTMASTER : ESM_USRTMP;
244 			break;
245 
246 		  case ESM_DEADLETTER:
247 			/*
248 			**  Save the message in dead.letter.
249 			**	If we weren't mailing back, and the user is
250 			**	local, we should save the message in
251 			**	~/dead.letter so that the poor person doesn't
252 			**	have to type it over again -- and we all know
253 			**	what poor typists UNIX users are.
254 			*/
255 
256 			p = NULL;
257 			if (e->e_from.q_mailer == LocalMailer)
258 			{
259 				if (e->e_from.q_home != NULL)
260 					p = e->e_from.q_home;
261 				else if ((pw = getpwnam(e->e_from.q_user)) != NULL)
262 					p = pw->pw_dir;
263 			}
264 			if (p == NULL)
265 			{
266 				syserr("Can't return mail to %s", e->e_from.q_paddr);
267 				state = ESM_MAIL;
268 				break;
269 			}
270 			if (e->e_dfp != NULL)
271 			{
272 				auto ADDRESS *q;
273 				bool oldverb = Verbose;
274 
275 				/* we have a home directory; open dead.letter */
276 				define('z', p, e);
277 				expand("\001z/dead.letter", buf, &buf[sizeof buf - 1], e);
278 				Verbose = TRUE;
279 				message(Arpa_Info, "Saving message in %s", buf);
280 				Verbose = oldverb;
281 				e->e_to = buf;
282 				q = NULL;
283 				sendtolist(buf, (ADDRESS *) NULL, &q);
284 				if (deliver(e, q) == 0)
285 					state = ESM_DONE;
286 				else
287 					state = ESM_MAIL;
288 			}
289 			else
290 			{
291 				/* no data file -- try mailing back */
292 				state = ESM_MAIL;
293 			}
294 			break;
295 
296 		  case ESM_USRTMP:
297 			/*
298 			**  Log the mail in /usr/tmp/dead.letter.
299 			*/
300 
301 			fp = dfopen("/usr/tmp/dead.letter", "a");
302 			if (fp == NULL)
303 			{
304 				state = ESM_PANIC;
305 				break;
306 			}
307 
308 			putfromline(fp, ProgMailer);
309 			(*e->e_puthdr)(fp, ProgMailer, e);
310 			putline("\n", fp, ProgMailer);
311 			(*e->e_putbody)(fp, ProgMailer, e);
312 			putline("\n", fp, ProgMailer);
313 			(void) fflush(fp);
314 			state = ferror(fp) ? ESM_PANIC : ESM_DONE;
315 			(void) fclose(fp);
316 			break;
317 
318 		  default:
319 			syserr("savemail: unknown state %d", state);
320 
321 			/* fall through ... */
322 
323 		  case ESM_PANIC:
324 			syserr("savemail: HELP!!!!");
325 # ifdef LOG
326 			if (LogLevel >= 1)
327 				syslog(LOG_ALERT, "savemail: HELP!!!!");
328 # endif LOG
329 
330 			/* leave the locked queue & transcript files around */
331 			exit(EX_SOFTWARE);
332 		}
333 	}
334 }
335 /*
336 **  RETURNTOSENDER -- return a message to the sender with an error.
337 **
338 **	Parameters:
339 **		msg -- the explanatory message.
340 **		returnq -- the queue of people to send the message to.
341 **		sendbody -- if TRUE, also send back the body of the
342 **			message; otherwise just send the header.
343 **
344 **	Returns:
345 **		zero -- if everything went ok.
346 **		else -- some error.
347 **
348 **	Side Effects:
349 **		Returns the current message to the sender via
350 **		mail.
351 */
352 
353 static bool	SendBody;
354 
355 #define MAXRETURNS	6	/* max depth of returning messages */
356 
357 returntosender(msg, returnq, sendbody)
358 	char *msg;
359 	ADDRESS *returnq;
360 	bool sendbody;
361 {
362 	char buf[MAXNAME];
363 	extern putheader(), errbody();
364 	register ENVELOPE *ee;
365 	extern ENVELOPE *newenvelope();
366 	ENVELOPE errenvelope;
367 	static int returndepth;
368 	register ADDRESS *q;
369 
370 # ifdef DEBUG
371 	if (tTd(6, 1))
372 	{
373 		printf("Return To Sender: msg=\"%s\", depth=%d, CurEnv=%x,\n",
374 		       msg, returndepth, CurEnv);
375 		printf("\treturnq=");
376 		printaddr(returnq, TRUE);
377 	}
378 # endif DEBUG
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