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	6.2 (Berkeley) 01/09/93";
11 #endif /* not lint */
12 
13 # include <sys/types.h>
14 # include <pwd.h>
15 # include "sendmail.h"
16 
17 /*
18 **  SAVEMAIL -- Save mail on error
19 **
20 **	If mailing back errors, mail it back to the originator
21 **	together with an error message; otherwise, just put it in
22 **	dead.letter in the user's home directory (if he exists on
23 **	this machine).
24 **
25 **	Parameters:
26 **		e -- the envelope containing the message in error.
27 **
28 **	Returns:
29 **		none
30 **
31 **	Side Effects:
32 **		Saves the letter, by writing or mailing it back to the
33 **		sender, or by putting it in dead.letter in her home
34 **		directory.
35 */
36 
37 /* defines for state machine */
38 # define ESM_REPORT	0	/* report to sender's terminal */
39 # define ESM_MAIL	1	/* mail back to sender */
40 # define ESM_QUIET	2	/* messages have already been returned */
41 # define ESM_DEADLETTER	3	/* save in ~/dead.letter */
42 # define ESM_POSTMASTER	4	/* return to postmaster */
43 # define ESM_USRTMP	5	/* save in /usr/tmp/dead.letter */
44 # define ESM_PANIC	6	/* leave the locked queue/transcript files */
45 # define ESM_DONE	7	/* the message is successfully delivered */
46 
47 
48 savemail(e)
49 	register ENVELOPE *e;
50 {
51 	register struct passwd *pw;
52 	register FILE *fp;
53 	int state;
54 	auto ADDRESS *q;
55 	char buf[MAXLINE+1];
56 	extern struct passwd *getpwnam();
57 	register char *p;
58 	extern char *ttypath();
59 	typedef int (*fnptr)();
60 
61 	if (tTd(6, 1))
62 		printf("\nsavemail, ErrorMode = %c\n", ErrorMode);
63 
64 	if (bitset(EF_RESPONSE, e->e_flags))
65 		return;
66 	ForceMail = TRUE;
67 	e->e_flags &= ~EF_FATALERRS;
68 
69 	/*
70 	**  In the unhappy event we don't know who to return the mail
71 	**  to, make someone up.
72 	*/
73 
74 	if (e->e_from.q_paddr == NULL)
75 	{
76 		if (parseaddr("root", &e->e_from, 0, '\0', e) == NULL)
77 		{
78 			syserr("Cannot parse root!");
79 			ExitStat = EX_SOFTWARE;
80 			finis();
81 		}
82 	}
83 	e->e_to = NULL;
84 
85 	/*
86 	**  Basic state machine.
87 	**
88 	**	This machine runs through the following states:
89 	**
90 	**	ESM_QUIET	Errors have already been printed iff the
91 	**			sender is local.
92 	**	ESM_REPORT	Report directly to the sender's terminal.
93 	**	ESM_MAIL	Mail response to the sender.
94 	**	ESM_DEADLETTER	Save response in ~/dead.letter.
95 	**	ESM_POSTMASTER	Mail response to the postmaster.
96 	**	ESM_PANIC	Save response anywhere possible.
97 	*/
98 
99 	/* determine starting state */
100 	switch (ErrorMode)
101 	{
102 	  case EM_WRITE:
103 		state = ESM_REPORT;
104 		break;
105 
106 	  case EM_BERKNET:
107 		/* mail back, but return o.k. exit status */
108 		ExitStat = EX_OK;
109 
110 		/* fall through.... */
111 
112 	  case EM_MAIL:
113 		state = ESM_MAIL;
114 		break;
115 
116 	  case EM_PRINT:
117 	  case '\0':
118 		state = ESM_QUIET;
119 		break;
120 
121 	  case EM_QUIET:
122 		/* no need to return anything at all */
123 		return;
124 
125 	  default:
126 		syserr("savemail: ErrorMode x%x\n");
127 		state = ESM_MAIL;
128 		break;
129 	}
130 
131 	while (state != ESM_DONE)
132 	{
133 		if (tTd(6, 5))
134 			printf("  state %d\n", state);
135 
136 		switch (state)
137 		{
138 		  case ESM_QUIET:
139 			if (e->e_from.q_mailer == LocalMailer)
140 				state = ESM_DEADLETTER;
141 			else
142 				state = ESM_MAIL;
143 			break;
144 
145 		  case ESM_REPORT:
146 
147 			/*
148 			**  If the user is still logged in on the same terminal,
149 			**  then write the error messages back to hir (sic).
150 			*/
151 
152 			p = ttypath();
153 			if (p == NULL || freopen(p, "w", stdout) == NULL)
154 			{
155 				state = ESM_MAIL;
156 				break;
157 			}
158 
159 			expand("\001n", buf, &buf[sizeof buf - 1], e);
160 			printf("\r\nMessage from %s...\r\n", buf);
161 			printf("Errors occurred while sending mail.\r\n");
162 			if (e->e_xfp != NULL)
163 			{
164 				(void) fflush(e->e_xfp);
165 				fp = fopen(queuename(e, 'x'), "r");
166 			}
167 			else
168 				fp = NULL;
169 			if (fp == NULL)
170 			{
171 				syserr("Cannot open %s", queuename(e, 'x'));
172 				printf("Transcript of session is unavailable.\r\n");
173 			}
174 			else
175 			{
176 				printf("Transcript follows:\r\n");
177 				while (fgets(buf, sizeof buf, fp) != NULL &&
178 				       !ferror(stdout))
179 					fputs(buf, stdout);
180 				(void) fclose(fp);
181 			}
182 			printf("Original message will be saved in dead.letter.\r\n");
183 			state = ESM_DEADLETTER;
184 			break;
185 
186 		  case ESM_MAIL:
187 		  case ESM_POSTMASTER:
188 			/*
189 			**  If mailing back, do it.
190 			**	Throw away all further output.  Don't alias,
191 			**	since this could cause loops, e.g., if joe
192 			**	mails to joe@x, and for some reason the network
193 			**	for @x is down, then the response gets sent to
194 			**	joe@x, which gives a response, etc.  Also force
195 			**	the mail to be delivered even if a version of
196 			**	it has already been sent to the sender.
197 			*/
198 
199 			if (state == ESM_MAIL)
200 			{
201 				if (e->e_errorqueue == NULL)
202 					sendtolist(e->e_from.q_paddr,
203 						(ADDRESS *) NULL,
204 						&e->e_errorqueue, e);
205 
206 				/* deliver a cc: to the postmaster if desired */
207 				if (PostMasterCopy != NULL)
208 					sendtolist(PostMasterCopy,
209 						(ADDRESS *) NULL,
210 						&e->e_errorqueue, e);
211 				q = e->e_errorqueue;
212 			}
213 			else
214 			{
215 				if (parseaddr("postmaster", q, 0, '\0', e) == NULL)
216 				{
217 					syserr("cannot parse postmaster!");
218 					ExitStat = EX_SOFTWARE;
219 					state = ESM_USRTMP;
220 					break;
221 				}
222 			}
223 			if (returntosender(e->e_message != NULL ? e->e_message :
224 					   "Unable to deliver mail",
225 					   q, (e->e_class >= 0), e) == 0)
226 			{
227 				state = ESM_DONE;
228 				break;
229 			}
230 
231 			state = state == ESM_MAIL ? ESM_POSTMASTER : ESM_USRTMP;
232 			break;
233 
234 		  case ESM_DEADLETTER:
235 			/*
236 			**  Save the message in dead.letter.
237 			**	If we weren't mailing back, and the user is
238 			**	local, we should save the message in
239 			**	~/dead.letter so that the poor person doesn't
240 			**	have to type it over again -- and we all know
241 			**	what poor typists UNIX users are.
242 			*/
243 
244 			p = NULL;
245 			if (e->e_from.q_mailer == LocalMailer)
246 			{
247 				if (e->e_from.q_home != NULL)
248 					p = e->e_from.q_home;
249 				else if ((pw = getpwnam(e->e_from.q_user)) != NULL)
250 					p = pw->pw_dir;
251 			}
252 			if (p == NULL)
253 			{
254 				syserr("Can't return mail to %s", e->e_from.q_paddr);
255 				state = ESM_MAIL;
256 				break;
257 			}
258 			if (e->e_dfp != NULL)
259 			{
260 				auto ADDRESS *q;
261 				bool oldverb = Verbose;
262 
263 				/* we have a home directory; open dead.letter */
264 				define('z', p, e);
265 				expand("\001z/dead.letter", buf, &buf[sizeof buf - 1], e);
266 				Verbose = TRUE;
267 				message(Arpa_Info, "Saving message in %s", buf);
268 				Verbose = oldverb;
269 				e->e_to = buf;
270 				q = NULL;
271 				sendtolist(buf, (ADDRESS *) NULL, &q, e);
272 				if (deliver(e, q) == 0)
273 					state = ESM_DONE;
274 				else
275 					state = ESM_MAIL;
276 			}
277 			else
278 			{
279 				/* no data file -- try mailing back */
280 				state = ESM_MAIL;
281 			}
282 			break;
283 
284 		  case ESM_USRTMP:
285 			/*
286 			**  Log the mail in /usr/tmp/dead.letter.
287 			*/
288 
289 			if (e->e_class < 0)
290 			{
291 				state = ESM_DONE;
292 				break;
293 			}
294 
295 			fp = dfopen("/usr/tmp/dead.letter", "a");
296 			if (fp == NULL)
297 			{
298 				state = ESM_PANIC;
299 				break;
300 			}
301 
302 			putfromline(fp, ProgMailer, e);
303 			(*e->e_puthdr)(fp, ProgMailer, e);
304 			putline("\n", fp, ProgMailer);
305 			(*e->e_putbody)(fp, ProgMailer, e);
306 			putline("\n", fp, ProgMailer);
307 			(void) fflush(fp);
308 			state = ferror(fp) ? ESM_PANIC : ESM_DONE;
309 			(void) fclose(fp);
310 			break;
311 
312 		  default:
313 			syserr("savemail: unknown state %d", state);
314 
315 			/* fall through ... */
316 
317 		  case ESM_PANIC:
318 			/* leave the locked queue & transcript files around */
319 			syserr("savemail: cannot save rejected email anywhere");
320 			exit(EX_SOFTWARE);
321 		}
322 	}
323 }
324 /*
325 **  RETURNTOSENDER -- return a message to the sender with an error.
326 **
327 **	Parameters:
328 **		msg -- the explanatory message.
329 **		returnq -- the queue of people to send the message to.
330 **		sendbody -- if TRUE, also send back the body of the
331 **			message; otherwise just send the header.
332 **		e -- the current envelope.
333 **
334 **	Returns:
335 **		zero -- if everything went ok.
336 **		else -- some error.
337 **
338 **	Side Effects:
339 **		Returns the current message to the sender via
340 **		mail.
341 */
342 
343 static bool	SendBody;
344 
345 #define MAXRETURNS	6	/* max depth of returning messages */
346 
347 returntosender(msg, returnq, sendbody, e)
348 	char *msg;
349 	ADDRESS *returnq;
350 	bool sendbody;
351 	register ENVELOPE *e;
352 {
353 	char buf[MAXNAME];
354 	extern putheader(), errbody();
355 	register ENVELOPE *ee;
356 	extern ENVELOPE *newenvelope();
357 	ENVELOPE errenvelope;
358 	static int returndepth;
359 	register ADDRESS *q;
360 
361 	if (tTd(6, 1))
362 	{
363 		printf("Return To Sender: msg=\"%s\", depth=%d, e=%x,\n",
364 		       msg, returndepth, e);
365 		printf("\treturnq=");
366 		printaddr(returnq, TRUE);
367 	}
368 
369 	if (++returndepth >= MAXRETURNS)
370 	{
371 		if (returndepth != MAXRETURNS)
372 			syserr("returntosender: infinite recursion on %s", returnq->q_paddr);
373 		/* don't "unrecurse" and fake a clean exit */
374 		/* returndepth--; */
375 		return (0);
376 	}
377 
378 	SendBody = sendbody;
379 	define('g', "\001f", e);
380 	define('<', "\001f", e);
381 	ee = newenvelope(&errenvelope);
382 	define('a', "\001b", ee);
383 	ee->e_puthdr = putheader;
384 	ee->e_putbody = errbody;
385 	ee->e_flags |= EF_RESPONSE;
386 	if (!bitset(EF_OLDSTYLE, e->e_flags))
387 		ee->e_flags &= ~EF_OLDSTYLE;
388 	ee->e_sendqueue = returnq;
389 	openxscript(ee);
390 	for (q = returnq; q != NULL; q = q->q_next)
391 	{
392 		if (q->q_alias == NULL)
393 			addheader("to", q->q_paddr, ee);
394 	}
395 
396 	(void) sprintf(buf, "Returned mail: %s", msg);
397 	addheader("subject", buf, ee);
398 
399 	/* fake up an address header for the from person */
400 	expand("\001n", buf, &buf[sizeof buf - 1], e);
401 	ee->e_sender = ee->e_returnpath = newstr(buf);
402 	if (parseaddr(buf, &ee->e_from, -1, '\0', e) == NULL)
403 	{
404 		syserr("Can't parse myself!");
405 		ExitStat = EX_SOFTWARE;
406 		returndepth--;
407 		return (-1);
408 	}
409 	loweraddr(&ee->e_from);
410 
411 	/* push state into submessage */
412 	CurEnv = ee;
413 	define('f', "\001n", ee);
414 	define('x', "Mail Delivery Subsystem", ee);
415 	eatheader(ee);
416 
417 	/* actually deliver the error message */
418 	sendall(ee, SM_DEFAULT);
419 
420 	/* restore state */
421 	dropenvelope(ee);
422 	CurEnv = CurEnv->e_parent;
423 	returndepth--;
424 
425 	/* should check for delivery errors here */
426 	return (0);
427 }
428 /*
429 **  ERRBODY -- output the body of an error message.
430 **
431 **	Typically this is a copy of the transcript plus a copy of the
432 **	original offending message.
433 **
434 **	Parameters:
435 **		fp -- the output file.
436 **		m -- the mailer to output to.
437 **		e -- the envelope we are working in.
438 **
439 **	Returns:
440 **		none
441 **
442 **	Side Effects:
443 **		Outputs the body of an error message.
444 */
445 
446 errbody(fp, m, e)
447 	register FILE *fp;
448 	register struct mailer *m;
449 	register ENVELOPE *e;
450 {
451 	register FILE *xfile;
452 	char buf[MAXLINE];
453 	char *p;
454 
455 	/*
456 	**  Output error message header (if specified and available).
457 	*/
458 
459 	if (ErrMsgFile != NULL)
460 	{
461 		if (*ErrMsgFile == '/')
462 		{
463 			xfile = fopen(ErrMsgFile, "r");
464 			if (xfile != NULL)
465 			{
466 				while (fgets(buf, sizeof buf, xfile) != NULL)
467 				{
468 					expand(buf, buf, &buf[sizeof buf - 1], e);
469 					putline(buf, fp, m);
470 				}
471 				(void) fclose(xfile);
472 				fprintf(fp, "\n");
473 			}
474 		}
475 		else
476 		{
477 			expand(ErrMsgFile, buf, &buf[sizeof buf - 1], e);
478 			putline(buf, fp, m);
479 			fprintf(fp, "\n");
480 		}
481 	}
482 
483 	/*
484 	**  Output transcript of errors
485 	*/
486 
487 	(void) fflush(stdout);
488 	p = queuename(e->e_parent, 'x');
489 	if ((xfile = fopen(p, "r")) == NULL)
490 	{
491 		syserr("Cannot open %s", p);
492 		fprintf(fp, "  ----- Transcript of session is unavailable -----\n");
493 	}
494 	else
495 	{
496 		fprintf(fp, "   ----- Transcript of session follows -----\n");
497 		if (e->e_xfp != NULL)
498 			(void) fflush(e->e_xfp);
499 		while (fgets(buf, sizeof buf, xfile) != NULL)
500 			putline(buf, fp, m);
501 		(void) fclose(xfile);
502 	}
503 	errno = 0;
504 
505 	/*
506 	**  Output text of original message
507 	*/
508 
509 	if (NoReturn)
510 		fprintf(fp, "\n   ----- Return message suppressed -----\n\n");
511 	else if (e->e_parent->e_dfp != NULL)
512 	{
513 		if (SendBody)
514 		{
515 			putline("\n", fp, m);
516 			putline("   ----- Unsent message follows -----\n", fp, m);
517 			(void) fflush(fp);
518 			putheader(fp, m, e->e_parent);
519 			putline("\n", fp, m);
520 			putbody(fp, m, e->e_parent);
521 		}
522 		else
523 		{
524 			putline("\n", fp, m);
525 			putline("  ----- Message header follows -----\n", fp, m);
526 			(void) fflush(fp);
527 			putheader(fp, m, e->e_parent);
528 		}
529 	}
530 	else
531 	{
532 		putline("\n", fp, m);
533 		putline("  ----- No message was collected -----\n", fp, m);
534 		putline("\n", fp, m);
535 	}
536 
537 	/*
538 	**  Cleanup and exit
539 	*/
540 
541 	if (errno != 0)
542 		syserr("errbody: I/O error");
543 }
544