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	5.4 (Berkeley) 09/19/85";
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\n");
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 		state = ESM_QUIET;
126 		break;
127 
128 	  case EM_QUIET:
129 		/* no need to return anything at all */
130 		return;
131 	}
132 
133 	while (state != ESM_DONE)
134 	{
135 		switch (state)
136 		{
137 		  case ESM_REPORT:
138 
139 			/*
140 			**  If the user is still logged in on the same terminal,
141 			**  then write the error messages back to hir (sic).
142 			*/
143 
144 			p = ttypath();
145 			if (p == NULL || freopen(p, "w", stdout) == NULL)
146 			{
147 				state = ESM_MAIL;
148 				break;
149 			}
150 
151 			expand("\001n", buf, &buf[sizeof buf - 1], e);
152 			printf("\r\nMessage from %s...\r\n", buf);
153 			printf("Errors occurred while sending mail.\r\n");
154 			if (e->e_xfp != NULL)
155 			{
156 				(void) fflush(e->e_xfp);
157 				fp = fopen(queuename(e, 'x'), "r");
158 			}
159 			else
160 				fp = NULL;
161 			if (fp == NULL)
162 			{
163 				syserr("Cannot open %s", queuename(e, 'x'));
164 				printf("Transcript of session is unavailable.\r\n");
165 			}
166 			else
167 			{
168 				printf("Transcript follows:\r\n");
169 				while (fgets(buf, sizeof buf, fp) != NULL &&
170 				       !ferror(stdout))
171 					fputs(buf, stdout);
172 				(void) fclose(fp);
173 			}
174 			printf("Original message will be saved in dead.letter.\r\n");
175 			if (ferror(stdout))
176 				(void) syserr("savemail: stdout: write err");
177 			state = ESM_DEADLETTER;
178 			break;
179 
180 		  case ESM_MAIL:
181 		  case ESM_POSTMASTER:
182 			/*
183 			**  If mailing back, do it.
184 			**	Throw away all further output.  Don't alias,
185 			**	since this could cause loops, e.g., if joe
186 			**	mails to joe@x, and for some reason the network
187 			**	for @x is down, then the response gets sent to
188 			**	joe@x, which gives a response, etc.  Also force
189 			**	the mail to be delivered even if a version of
190 			**	it has already been sent to the sender.
191 			*/
192 
193 			if (state == ESM_MAIL)
194 			{
195 				if (e->e_errorqueue == NULL)
196 					sendtolist(e->e_from.q_paddr,
197 						(ADDRESS *) NULL,
198 						&e->e_errorqueue);
199 				q = e->e_errorqueue;
200 			}
201 			else
202 			{
203 				if (parseaddr("postmaster", q, 0, '\0') == NULL)
204 				{
205 					syserr("cannot parse postmaster!");
206 					ExitStat = EX_SOFTWARE;
207 					state = ESM_USRTMP;
208 					break;
209 				}
210 			}
211 			if (returntosender(e->e_message != NULL ? e->e_message :
212 					   "Unable to deliver mail",
213 					   q, TRUE) == 0)
214 			{
215 				state = ESM_DONE;
216 				break;
217 			}
218 
219 			state = state == ESM_MAIL ? ESM_POSTMASTER : ESM_USRTMP;
220 			break;
221 
222 		  case ESM_DEADLETTER:
223 			/*
224 			**  Save the message in dead.letter.
225 			**	If we weren't mailing back, and the user is
226 			**	local, we should save the message in
227 			**	~/dead.letter so that the poor person doesn't
228 			**	have to type it over again -- and we all know
229 			**	what poor typists UNIX users are.
230 			*/
231 
232 			p = NULL;
233 			if (e->e_from.q_mailer == LocalMailer)
234 			{
235 				if (e->e_from.q_home != NULL)
236 					p = e->e_from.q_home;
237 				else if ((pw = getpwnam(e->e_from.q_user)) != NULL)
238 					p = pw->pw_dir;
239 			}
240 			if (p == NULL)
241 			{
242 				syserr("Can't return mail to %s", e->e_from.q_paddr);
243 				state = ESM_MAIL;
244 				break;
245 			}
246 			if (e->e_dfp != NULL)
247 			{
248 				auto ADDRESS *q;
249 				bool oldverb = Verbose;
250 
251 				/* we have a home directory; open dead.letter */
252 				define('z', p, e);
253 				expand("\001z/dead.letter", buf, &buf[sizeof buf - 1], e);
254 				Verbose = TRUE;
255 				message(Arpa_Info, "Saving message in %s", buf);
256 				Verbose = oldverb;
257 				e->e_to = buf;
258 				q = NULL;
259 				sendtolist(buf, (ADDRESS *) NULL, &q);
260 				if (deliver(e, q) == 0)
261 					state = ESM_DONE;
262 				else
263 					state = ESM_MAIL;
264 			}
265 			break;
266 
267 		  case ESM_USRTMP:
268 			/*
269 			**  Log the mail in /usr/tmp/dead.letter.
270 			*/
271 
272 			fp = dfopen("/usr/tmp/dead.letter", "a");
273 			if (fp == NULL)
274 			{
275 				state = ESM_PANIC;
276 				break;
277 			}
278 
279 			putfromline(fp, ProgMailer);
280 			(*e->e_puthdr)(fp, ProgMailer, e);
281 			putline("\n", fp, ProgMailer);
282 			(*e->e_putbody)(fp, ProgMailer, e);
283 			putline("\n", fp, ProgMailer);
284 			(void) fflush(fp);
285 			state = ferror(fp) ? ESM_PANIC : ESM_DONE;
286 			(void) fclose(fp);
287 			break;
288 
289 		  default:
290 			syserr("savemail: unknown state %d", state);
291 
292 			/* fall through ... */
293 
294 		  case ESM_PANIC:
295 			syserr("savemail: HELP!!!!");
296 # ifdef LOG
297 			if (LogLevel >= 1)
298 				syslog(LOG_ALERT, "savemail: HELP!!!!");
299 # endif LOG
300 
301 			/* leave the locked queue & transcript files around */
302 			exit(EX_SOFTWARE);
303 		}
304 	}
305 }
306 /*
307 **  RETURNTOSENDER -- return a message to the sender with an error.
308 **
309 **	Parameters:
310 **		msg -- the explanatory message.
311 **		returnq -- the queue of people to send the message to.
312 **		sendbody -- if TRUE, also send back the body of the
313 **			message; otherwise just send the header.
314 **
315 **	Returns:
316 **		zero -- if everything went ok.
317 **		else -- some error.
318 **
319 **	Side Effects:
320 **		Returns the current message to the sender via
321 **		mail.
322 */
323 
324 static bool	SendBody;
325 
326 #define MAXRETURNS	6	/* max depth of returning messages */
327 
328 returntosender(msg, returnq, sendbody)
329 	char *msg;
330 	ADDRESS *returnq;
331 	bool sendbody;
332 {
333 	char buf[MAXNAME];
334 	extern putheader(), errbody();
335 	register ENVELOPE *ee;
336 	extern ENVELOPE *newenvelope();
337 	ENVELOPE errenvelope;
338 	static int returndepth;
339 	register ADDRESS *q;
340 
341 # ifdef DEBUG
342 	if (tTd(6, 1))
343 	{
344 		printf("Return To Sender: msg=\"%s\", depth=%d, CurEnv=%x,\n",
345 		       msg, returndepth, CurEnv);
346 		printf("\treturnq=");
347 		printaddr(returnq, TRUE);
348 	}
349 # endif DEBUG
350 
351 	if (++returndepth >= MAXRETURNS)
352 	{
353 		if (returndepth != MAXRETURNS)
354 			syserr("returntosender: infinite recursion on %s", returnq->q_paddr);
355 		/* don't "unrecurse" and fake a clean exit */
356 		/* returndepth--; */
357 		return (0);
358 	}
359 
360 	SendBody = sendbody;
361 	define('g', "\001f", CurEnv);
362 	ee = newenvelope(&errenvelope);
363 	define('a', "\001b", ee);
364 	ee->e_puthdr = putheader;
365 	ee->e_putbody = errbody;
366 	ee->e_flags |= EF_RESPONSE;
367 	ee->e_sendqueue = returnq;
368 	openxscript(ee);
369 	for (q = returnq; q != NULL; q = q->q_next)
370 	{
371 		if (q->q_alias == NULL)
372 			addheader("to", q->q_paddr, ee);
373 	}
374 
375 	(void) sprintf(buf, "Returned mail: %s", msg);
376 	addheader("subject", buf, ee);
377 
378 	/* fake up an address header for the from person */
379 	expand("\001n", buf, &buf[sizeof buf - 1], CurEnv);
380 	if (parseaddr(buf, &ee->e_from, -1, '\0') == NULL)
381 	{
382 		syserr("Can't parse myself!");
383 		ExitStat = EX_SOFTWARE;
384 		returndepth--;
385 		return (-1);
386 	}
387 	loweraddr(&ee->e_from);
388 
389 	/* push state into submessage */
390 	CurEnv = ee;
391 	define('f', "\001n", ee);
392 	define('x', "Mail Delivery Subsystem", ee);
393 	eatheader(ee);
394 
395 	/* actually deliver the error message */
396 	sendall(ee, SM_DEFAULT);
397 
398 	/* restore state */
399 	dropenvelope(ee);
400 	CurEnv = CurEnv->e_parent;
401 	returndepth--;
402 
403 	/* should check for delivery errors here */
404 	return (0);
405 }
406 /*
407 **  ERRBODY -- output the body of an error message.
408 **
409 **	Typically this is a copy of the transcript plus a copy of the
410 **	original offending message.
411 **
412 **	Parameters:
413 **		fp -- the output file.
414 **		m -- the mailer to output to.
415 **		e -- the envelope we are working in.
416 **
417 **	Returns:
418 **		none
419 **
420 **	Side Effects:
421 **		Outputs the body of an error message.
422 */
423 
424 errbody(fp, m, e)
425 	register FILE *fp;
426 	register struct mailer *m;
427 	register ENVELOPE *e;
428 {
429 	register FILE *xfile;
430 	char buf[MAXLINE];
431 	char *p;
432 
433 	/*
434 	**  Output transcript of errors
435 	*/
436 
437 	(void) fflush(stdout);
438 	p = queuename(e->e_parent, 'x');
439 	if ((xfile = fopen(p, "r")) == NULL)
440 	{
441 		syserr("Cannot open %s", p);
442 		fprintf(fp, "  ----- Transcript of session is unavailable -----\n");
443 	}
444 	else
445 	{
446 		fprintf(fp, "   ----- Transcript of session follows -----\n");
447 		if (e->e_xfp != NULL)
448 			(void) fflush(e->e_xfp);
449 		while (fgets(buf, sizeof buf, xfile) != NULL)
450 			putline(buf, fp, m);
451 		(void) fclose(xfile);
452 	}
453 	errno = 0;
454 
455 	/*
456 	**  Output text of original message
457 	*/
458 
459 	if (NoReturn)
460 		fprintf(fp, "\n   ----- Return message suppressed -----\n\n");
461 	else if (e->e_parent->e_dfp != NULL)
462 	{
463 		if (SendBody)
464 		{
465 			putline("\n", fp, m);
466 			putline("   ----- Unsent message follows -----\n", fp, m);
467 			(void) fflush(fp);
468 			putheader(fp, m, e->e_parent);
469 			putline("\n", fp, m);
470 			putbody(fp, m, e->e_parent);
471 		}
472 		else
473 		{
474 			putline("\n", fp, m);
475 			putline("  ----- Message header follows -----\n", fp, m);
476 			(void) fflush(fp);
477 			putheader(fp, m, e->e_parent);
478 		}
479 	}
480 	else
481 	{
482 		putline("\n", fp, m);
483 		putline("  ----- No message was collected -----\n", fp, m);
484 		putline("\n", fp, m);
485 	}
486 
487 	/*
488 	**  Cleanup and exit
489 	*/
490 
491 	if (errno != 0)
492 		syserr("errbody: I/O error");
493 }
494