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	5.14 (Berkeley) 08/29/90";
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 	if (e->e_class < 0)
67 	{
68 		message(Arpa_Info, "Dumping junk mail");
69 		return;
70 	}
71 	ForceMail = TRUE;
72 	e->e_flags &= ~EF_FATALERRS;
73 
74 	/*
75 	**  In the unhappy event we don't know who to return the mail
76 	**  to, make someone up.
77 	*/
78 
79 	if (e->e_from.q_paddr == NULL)
80 	{
81 		if (parseaddr("root", &e->e_from, 0, '\0') == NULL)
82 		{
83 			syserr("Cannot parse root!");
84 			ExitStat = EX_SOFTWARE;
85 			finis();
86 		}
87 	}
88 	e->e_to = NULL;
89 
90 	/*
91 	**  Basic state machine.
92 	**
93 	**	This machine runs through the following states:
94 	**
95 	**	ESM_QUIET	Errors have already been printed iff the
96 	**			sender is local.
97 	**	ESM_REPORT	Report directly to the sender's terminal.
98 	**	ESM_MAIL	Mail response to the sender.
99 	**	ESM_DEADLETTER	Save response in ~/dead.letter.
100 	**	ESM_POSTMASTER	Mail response to the postmaster.
101 	**	ESM_PANIC	Save response anywhere possible.
102 	*/
103 
104 	/* determine starting state */
105 	switch (ErrorMode)
106 	{
107 	  case EM_WRITE:
108 		state = ESM_REPORT;
109 		break;
110 
111 	  case EM_BERKNET:
112 		/* mail back, but return o.k. exit status */
113 		ExitStat = EX_OK;
114 
115 		/* fall through.... */
116 
117 	  case EM_MAIL:
118 		state = ESM_MAIL;
119 		break;
120 
121 	  case EM_PRINT:
122 	  case '\0':
123 		state = ESM_QUIET;
124 		break;
125 
126 	  case EM_QUIET:
127 		/* no need to return anything at all */
128 		return;
129 
130 	  default:
131 		syserr("savemail: ErrorMode x%x\n");
132 		state = ESM_MAIL;
133 		break;
134 	}
135 
136 	while (state != ESM_DONE)
137 	{
138 		if (tTd(6, 5))
139 			printf("  state %d\n", state);
140 
141 		switch (state)
142 		{
143 		  case ESM_QUIET:
144 			if (e->e_from.q_mailer == LocalMailer)
145 				state = ESM_DEADLETTER;
146 			else
147 				state = ESM_MAIL;
148 			break;
149 
150 		  case ESM_REPORT:
151 
152 			/*
153 			**  If the user is still logged in on the same terminal,
154 			**  then write the error messages back to hir (sic).
155 			*/
156 
157 			p = ttypath();
158 			if (p == NULL || freopen(p, "w", stdout) == NULL)
159 			{
160 				state = ESM_MAIL;
161 				break;
162 			}
163 
164 			expand("\001n", buf, &buf[sizeof buf - 1], e);
165 			printf("\r\nMessage from %s...\r\n", buf);
166 			printf("Errors occurred while sending mail.\r\n");
167 			if (e->e_xfp != NULL)
168 			{
169 				(void) fflush(e->e_xfp);
170 				fp = fopen(queuename(e, 'x'), "r");
171 			}
172 			else
173 				fp = NULL;
174 			if (fp == NULL)
175 			{
176 				syserr("Cannot open %s", queuename(e, 'x'));
177 				printf("Transcript of session is unavailable.\r\n");
178 			}
179 			else
180 			{
181 				printf("Transcript follows:\r\n");
182 				while (fgets(buf, sizeof buf, fp) != NULL &&
183 				       !ferror(stdout))
184 					fputs(buf, stdout);
185 				(void) fclose(fp);
186 			}
187 			printf("Original message will be saved in dead.letter.\r\n");
188 			state = ESM_DEADLETTER;
189 			break;
190 
191 		  case ESM_MAIL:
192 		  case ESM_POSTMASTER:
193 			/*
194 			**  If mailing back, do it.
195 			**	Throw away all further output.  Don't alias,
196 			**	since this could cause loops, e.g., if joe
197 			**	mails to joe@x, and for some reason the network
198 			**	for @x is down, then the response gets sent to
199 			**	joe@x, which gives a response, etc.  Also force
200 			**	the mail to be delivered even if a version of
201 			**	it has already been sent to the sender.
202 			*/
203 
204 			if (state == ESM_MAIL)
205 			{
206 				if (e->e_errorqueue == NULL)
207 					sendtolist(e->e_from.q_paddr,
208 						(ADDRESS *) NULL,
209 						&e->e_errorqueue);
210 
211 				/* deliver a cc: to the postmaster if desired */
212 				if (PostMasterCopy != NULL)
213 					sendtolist(PostMasterCopy,
214 						(ADDRESS *) NULL,
215 						&e->e_errorqueue);
216 				q = e->e_errorqueue;
217 			}
218 			else
219 			{
220 				if (parseaddr("postmaster", q, 0, '\0') == NULL)
221 				{
222 					syserr("cannot parse postmaster!");
223 					ExitStat = EX_SOFTWARE;
224 					state = ESM_USRTMP;
225 					break;
226 				}
227 			}
228 			if (returntosender(e->e_message != NULL ? e->e_message :
229 					   "Unable to deliver mail",
230 					   q, TRUE) == 0)
231 			{
232 				state = ESM_DONE;
233 				break;
234 			}
235 
236 			state = state == ESM_MAIL ? ESM_POSTMASTER : ESM_USRTMP;
237 			break;
238 
239 		  case ESM_DEADLETTER:
240 			/*
241 			**  Save the message in dead.letter.
242 			**	If we weren't mailing back, and the user is
243 			**	local, we should save the message in
244 			**	~/dead.letter so that the poor person doesn't
245 			**	have to type it over again -- and we all know
246 			**	what poor typists UNIX users are.
247 			*/
248 
249 			p = NULL;
250 			if (e->e_from.q_mailer == LocalMailer)
251 			{
252 				if (e->e_from.q_home != NULL)
253 					p = e->e_from.q_home;
254 				else if ((pw = getpwnam(e->e_from.q_user)) != NULL)
255 					p = pw->pw_dir;
256 			}
257 			if (p == NULL)
258 			{
259 				syserr("Can't return mail to %s", e->e_from.q_paddr);
260 				state = ESM_MAIL;
261 				break;
262 			}
263 			if (e->e_dfp != NULL)
264 			{
265 				auto ADDRESS *q;
266 				bool oldverb = Verbose;
267 
268 				/* we have a home directory; open dead.letter */
269 				define('z', p, e);
270 				expand("\001z/dead.letter", buf, &buf[sizeof buf - 1], e);
271 				Verbose = TRUE;
272 				message(Arpa_Info, "Saving message in %s", buf);
273 				Verbose = oldverb;
274 				e->e_to = buf;
275 				q = NULL;
276 				sendtolist(buf, (ADDRESS *) NULL, &q);
277 				if (deliver(e, q) == 0)
278 					state = ESM_DONE;
279 				else
280 					state = ESM_MAIL;
281 			}
282 			else
283 			{
284 				/* no data file -- try mailing back */
285 				state = ESM_MAIL;
286 			}
287 			break;
288 
289 		  case ESM_USRTMP:
290 			/*
291 			**  Log the mail in /usr/tmp/dead.letter.
292 			*/
293 
294 			fp = dfopen("/usr/tmp/dead.letter", "a");
295 			if (fp == NULL)
296 			{
297 				state = ESM_PANIC;
298 				break;
299 			}
300 
301 			putfromline(fp, ProgMailer);
302 			(*e->e_puthdr)(fp, ProgMailer, e);
303 			putline("\n", fp, ProgMailer);
304 			(*e->e_putbody)(fp, ProgMailer, e);
305 			putline("\n", fp, ProgMailer);
306 			(void) fflush(fp);
307 			state = ferror(fp) ? ESM_PANIC : ESM_DONE;
308 			(void) fclose(fp);
309 			break;
310 
311 		  default:
312 			syserr("savemail: unknown state %d", state);
313 
314 			/* fall through ... */
315 
316 		  case ESM_PANIC:
317 			syserr("savemail: HELP!!!!");
318 # ifdef LOG
319 			if (LogLevel >= 1)
320 				syslog(LOG_ALERT, "savemail: HELP!!!!");
321 # endif LOG
322 
323 			/* leave the locked queue & transcript files around */
324 			exit(EX_SOFTWARE);
325 		}
326 	}
327 }
328 /*
329 **  RETURNTOSENDER -- return a message to the sender with an error.
330 **
331 **	Parameters:
332 **		msg -- the explanatory message.
333 **		returnq -- the queue of people to send the message to.
334 **		sendbody -- if TRUE, also send back the body of the
335 **			message; otherwise just send the header.
336 **
337 **	Returns:
338 **		zero -- if everything went ok.
339 **		else -- some error.
340 **
341 **	Side Effects:
342 **		Returns the current message to the sender via
343 **		mail.
344 */
345 
346 static bool	SendBody;
347 
348 #define MAXRETURNS	6	/* max depth of returning messages */
349 
350 returntosender(msg, returnq, sendbody)
351 	char *msg;
352 	ADDRESS *returnq;
353 	bool sendbody;
354 {
355 	char buf[MAXNAME];
356 	extern putheader(), errbody();
357 	register ENVELOPE *ee;
358 	extern ENVELOPE *newenvelope();
359 	ENVELOPE errenvelope;
360 	static int returndepth;
361 	register ADDRESS *q;
362 
363 	if (tTd(6, 1))
364 	{
365 		printf("Return To Sender: msg=\"%s\", depth=%d, CurEnv=%x,\n",
366 		       msg, returndepth, CurEnv);
367 		printf("\treturnq=");
368 		printaddr(returnq, TRUE);
369 	}
370 
371 	if (++returndepth >= MAXRETURNS)
372 	{
373 		if (returndepth != MAXRETURNS)
374 			syserr("returntosender: infinite recursion on %s", returnq->q_paddr);
375 		/* don't "unrecurse" and fake a clean exit */
376 		/* returndepth--; */
377 		return (0);
378 	}
379 
380 	SendBody = sendbody;
381 	define('g', "\001f", CurEnv);
382 	ee = newenvelope(&errenvelope);
383 	define('a', "\001b", ee);
384 	ee->e_puthdr = putheader;
385 	ee->e_putbody = errbody;
386 	ee->e_flags |= EF_RESPONSE;
387 	if (!bitset(EF_OLDSTYLE, CurEnv->e_flags))
388 		ee->e_flags &= ~EF_OLDSTYLE;
389 	ee->e_sendqueue = returnq;
390 	openxscript(ee);
391 	for (q = returnq; q != NULL; q = q->q_next)
392 	{
393 		if (q->q_alias == NULL)
394 			addheader("to", q->q_paddr, ee);
395 	}
396 
397 	(void) sprintf(buf, "Returned mail: %s", msg);
398 	addheader("subject", buf, ee);
399 
400 	/* fake up an address header for the from person */
401 	expand("\001n", buf, &buf[sizeof buf - 1], CurEnv);
402 	if (parseaddr(buf, &ee->e_from, -1, '\0') == 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 transcript of errors
457 	*/
458 
459 	(void) fflush(stdout);
460 	p = queuename(e->e_parent, 'x');
461 	if ((xfile = fopen(p, "r")) == NULL)
462 	{
463 		syserr("Cannot open %s", p);
464 		fprintf(fp, "  ----- Transcript of session is unavailable -----\n");
465 	}
466 	else
467 	{
468 		fprintf(fp, "   ----- Transcript of session follows -----\n");
469 		if (e->e_xfp != NULL)
470 			(void) fflush(e->e_xfp);
471 		while (fgets(buf, sizeof buf, xfile) != NULL)
472 			putline(buf, fp, m);
473 		(void) fclose(xfile);
474 	}
475 	errno = 0;
476 
477 	/*
478 	**  Output text of original message
479 	*/
480 
481 	if (NoReturn)
482 		fprintf(fp, "\n   ----- Return message suppressed -----\n\n");
483 	else if (e->e_parent->e_dfp != NULL)
484 	{
485 		if (SendBody)
486 		{
487 			putline("\n", fp, m);
488 			putline("   ----- Unsent message follows -----\n", fp, m);
489 			(void) fflush(fp);
490 			putheader(fp, m, e->e_parent);
491 			putline("\n", fp, m);
492 			putbody(fp, m, e->e_parent);
493 		}
494 		else
495 		{
496 			putline("\n", fp, m);
497 			putline("  ----- Message header follows -----\n", fp, m);
498 			(void) fflush(fp);
499 			putheader(fp, m, e->e_parent);
500 		}
501 	}
502 	else
503 	{
504 		putline("\n", fp, m);
505 		putline("  ----- No message was collected -----\n", fp, m);
506 		putline("\n", fp, m);
507 	}
508 
509 	/*
510 	**  Cleanup and exit
511 	*/
512 
513 	if (errno != 0)
514 		syserr("errbody: I/O error");
515 }
516