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	5.5 (Berkeley) 09/21/85";
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 				q = e->e_errorqueue;
218 			}
219 			else
220 			{
221 				if (parseaddr("postmaster", q, 0, '\0') == NULL)
222 				{
223 					syserr("cannot parse postmaster!");
224 					ExitStat = EX_SOFTWARE;
225 					state = ESM_USRTMP;
226 					break;
227 				}
228 			}
229 			if (returntosender(e->e_message != NULL ? e->e_message :
230 					   "Unable to deliver mail",
231 					   q, TRUE) == 0)
232 			{
233 				state = ESM_DONE;
234 				break;
235 			}
236 
237 			state = state == ESM_MAIL ? ESM_POSTMASTER : ESM_USRTMP;
238 			break;
239 
240 		  case ESM_DEADLETTER:
241 			/*
242 			**  Save the message in dead.letter.
243 			**	If we weren't mailing back, and the user is
244 			**	local, we should save the message in
245 			**	~/dead.letter so that the poor person doesn't
246 			**	have to type it over again -- and we all know
247 			**	what poor typists UNIX users are.
248 			*/
249 
250 			p = NULL;
251 			if (e->e_from.q_mailer == LocalMailer)
252 			{
253 				if (e->e_from.q_home != NULL)
254 					p = e->e_from.q_home;
255 				else if ((pw = getpwnam(e->e_from.q_user)) != NULL)
256 					p = pw->pw_dir;
257 			}
258 			if (p == NULL)
259 			{
260 				syserr("Can't return mail to %s", e->e_from.q_paddr);
261 				state = ESM_MAIL;
262 				break;
263 			}
264 			if (e->e_dfp != NULL)
265 			{
266 				auto ADDRESS *q;
267 				bool oldverb = Verbose;
268 
269 				/* we have a home directory; open dead.letter */
270 				define('z', p, e);
271 				expand("\001z/dead.letter", buf, &buf[sizeof buf - 1], e);
272 				Verbose = TRUE;
273 				message(Arpa_Info, "Saving message in %s", buf);
274 				Verbose = oldverb;
275 				e->e_to = buf;
276 				q = NULL;
277 				sendtolist(buf, (ADDRESS *) NULL, &q);
278 				if (deliver(e, q) == 0)
279 					state = ESM_DONE;
280 				else
281 					state = ESM_MAIL;
282 			}
283 			break;
284 
285 		  case ESM_USRTMP:
286 			/*
287 			**  Log the mail in /usr/tmp/dead.letter.
288 			*/
289 
290 			fp = dfopen("/usr/tmp/dead.letter", "a");
291 			if (fp == NULL)
292 			{
293 				state = ESM_PANIC;
294 				break;
295 			}
296 
297 			putfromline(fp, ProgMailer);
298 			(*e->e_puthdr)(fp, ProgMailer, e);
299 			putline("\n", fp, ProgMailer);
300 			(*e->e_putbody)(fp, ProgMailer, e);
301 			putline("\n", fp, ProgMailer);
302 			(void) fflush(fp);
303 			state = ferror(fp) ? ESM_PANIC : ESM_DONE;
304 			(void) fclose(fp);
305 			break;
306 
307 		  default:
308 			syserr("savemail: unknown state %d", state);
309 
310 			/* fall through ... */
311 
312 		  case ESM_PANIC:
313 			syserr("savemail: HELP!!!!");
314 # ifdef LOG
315 			if (LogLevel >= 1)
316 				syslog(LOG_ALERT, "savemail: HELP!!!!");
317 # endif LOG
318 
319 			/* leave the locked queue & transcript files around */
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 **
333 **	Returns:
334 **		zero -- if everything went ok.
335 **		else -- some error.
336 **
337 **	Side Effects:
338 **		Returns the current message to the sender via
339 **		mail.
340 */
341 
342 static bool	SendBody;
343 
344 #define MAXRETURNS	6	/* max depth of returning messages */
345 
346 returntosender(msg, returnq, sendbody)
347 	char *msg;
348 	ADDRESS *returnq;
349 	bool sendbody;
350 {
351 	char buf[MAXNAME];
352 	extern putheader(), errbody();
353 	register ENVELOPE *ee;
354 	extern ENVELOPE *newenvelope();
355 	ENVELOPE errenvelope;
356 	static int returndepth;
357 	register ADDRESS *q;
358 
359 # ifdef DEBUG
360 	if (tTd(6, 1))
361 	{
362 		printf("Return To Sender: msg=\"%s\", depth=%d, CurEnv=%x,\n",
363 		       msg, returndepth, CurEnv);
364 		printf("\treturnq=");
365 		printaddr(returnq, TRUE);
366 	}
367 # endif DEBUG
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", CurEnv);
380 	ee = newenvelope(&errenvelope);
381 	define('a', "\001b", ee);
382 	ee->e_puthdr = putheader;
383 	ee->e_putbody = errbody;
384 	ee->e_flags |= EF_RESPONSE;
385 	ee->e_sendqueue = returnq;
386 	openxscript(ee);
387 	for (q = returnq; q != NULL; q = q->q_next)
388 	{
389 		if (q->q_alias == NULL)
390 			addheader("to", q->q_paddr, ee);
391 	}
392 
393 	(void) sprintf(buf, "Returned mail: %s", msg);
394 	addheader("subject", buf, ee);
395 
396 	/* fake up an address header for the from person */
397 	expand("\001n", buf, &buf[sizeof buf - 1], CurEnv);
398 	if (parseaddr(buf, &ee->e_from, -1, '\0') == NULL)
399 	{
400 		syserr("Can't parse myself!");
401 		ExitStat = EX_SOFTWARE;
402 		returndepth--;
403 		return (-1);
404 	}
405 	loweraddr(&ee->e_from);
406 
407 	/* push state into submessage */
408 	CurEnv = ee;
409 	define('f', "\001n", ee);
410 	define('x', "Mail Delivery Subsystem", ee);
411 	eatheader(ee);
412 
413 	/* actually deliver the error message */
414 	sendall(ee, SM_DEFAULT);
415 
416 	/* restore state */
417 	dropenvelope(ee);
418 	CurEnv = CurEnv->e_parent;
419 	returndepth--;
420 
421 	/* should check for delivery errors here */
422 	return (0);
423 }
424 /*
425 **  ERRBODY -- output the body of an error message.
426 **
427 **	Typically this is a copy of the transcript plus a copy of the
428 **	original offending message.
429 **
430 **	Parameters:
431 **		fp -- the output file.
432 **		m -- the mailer to output to.
433 **		e -- the envelope we are working in.
434 **
435 **	Returns:
436 **		none
437 **
438 **	Side Effects:
439 **		Outputs the body of an error message.
440 */
441 
442 errbody(fp, m, e)
443 	register FILE *fp;
444 	register struct mailer *m;
445 	register ENVELOPE *e;
446 {
447 	register FILE *xfile;
448 	char buf[MAXLINE];
449 	char *p;
450 
451 	/*
452 	**  Output transcript of errors
453 	*/
454 
455 	(void) fflush(stdout);
456 	p = queuename(e->e_parent, 'x');
457 	if ((xfile = fopen(p, "r")) == NULL)
458 	{
459 		syserr("Cannot open %s", p);
460 		fprintf(fp, "  ----- Transcript of session is unavailable -----\n");
461 	}
462 	else
463 	{
464 		fprintf(fp, "   ----- Transcript of session follows -----\n");
465 		if (e->e_xfp != NULL)
466 			(void) fflush(e->e_xfp);
467 		while (fgets(buf, sizeof buf, xfile) != NULL)
468 			putline(buf, fp, m);
469 		(void) fclose(xfile);
470 	}
471 	errno = 0;
472 
473 	/*
474 	**  Output text of original message
475 	*/
476 
477 	if (NoReturn)
478 		fprintf(fp, "\n   ----- Return message suppressed -----\n\n");
479 	else if (e->e_parent->e_dfp != NULL)
480 	{
481 		if (SendBody)
482 		{
483 			putline("\n", fp, m);
484 			putline("   ----- Unsent message follows -----\n", fp, m);
485 			(void) fflush(fp);
486 			putheader(fp, m, e->e_parent);
487 			putline("\n", fp, m);
488 			putbody(fp, m, e->e_parent);
489 		}
490 		else
491 		{
492 			putline("\n", fp, m);
493 			putline("  ----- Message header follows -----\n", fp, m);
494 			(void) fflush(fp);
495 			putheader(fp, m, e->e_parent);
496 		}
497 	}
498 	else
499 	{
500 		putline("\n", fp, m);
501 		putline("  ----- No message was collected -----\n", fp, m);
502 		putline("\n", fp, m);
503 	}
504 
505 	/*
506 	**  Cleanup and exit
507 	*/
508 
509 	if (errno != 0)
510 		syserr("errbody: I/O error");
511 }
512