1 # include <stdio.h>
2 # include <ctype.h>
3 # include "sendmail.h"
4 
5 static char	SccsId[] = "@(#)parseaddr.c	3.13	08/08/81";
6 
7 /*
8 **  PARSE -- Parse an address
9 **
10 **	Parses an address and breaks it up into three parts: a
11 **	net to transmit the message on, the host to transmit it
12 **	to, and a user on that host.  These are loaded into an
13 **	ADDRESS header with the values squirreled away if necessary.
14 **	The "user" part may not be a real user; the process may
15 **	just reoccur on that machine.  For example, on a machine
16 **	with an arpanet connection, the address
17 **		csvax.bill@berkeley
18 **	will break up to a "user" of 'csvax.bill' and a host
19 **	of 'berkeley' -- to be transmitted over the arpanet.
20 **
21 **	Parameters:
22 **		addr -- the address to parse.
23 **		a -- a pointer to the address descriptor buffer.
24 **			If NULL, a header will be created.
25 **		copyf -- determines what shall be copied:
26 **			-1 -- don't copy anything.  The printname
27 **				(q_paddr) is just addr, and the
28 **				user & host are allocated internally
29 **				to parse.
30 **			0 -- copy out the parsed user & host, but
31 **				don't copy the printname.
32 **			+1 -- copy everything.
33 **
34 **	Returns:
35 **		A pointer to the address descriptor header (`a' if
36 **			`a' is non-NULL).
37 **		NULL on error.
38 **
39 **	Side Effects:
40 **		none
41 **
42 **	Called By:
43 **		main
44 **		sendto
45 **		alias
46 **		savemail
47 */
48 
49 # define DELIMCHARS	"$()<>,;\\\"\r\n"	/* word delimiters */
50 # define SPACESUB	('.'|0200)		/* substitution for <lwsp> */
51 
52 ADDRESS *
53 parse(addr, a, copyf)
54 	char *addr;
55 	register ADDRESS *a;
56 	int copyf;
57 {
58 	register char **pvp;
59 	register struct mailer *m;
60 	extern char **prescan();
61 	extern char *newstr();
62 	extern char *strcpy();
63 	extern ADDRESS *buildaddr();
64 
65 	/*
66 	**  Initialize and prescan address.
67 	*/
68 
69 	To = addr;
70 # ifdef DEBUG
71 	if (Debug)
72 		printf("\n--parse(%s)\n", addr);
73 # endif DEBUG
74 
75 	pvp = prescan(addr, '\0');
76 	if (pvp == NULL)
77 		return (NULL);
78 
79 	/*
80 	**  Apply rewriting rules.
81 	*/
82 
83 	rewrite(pvp);
84 
85 	/*
86 	**  See if we resolved to a real mailer.
87 	*/
88 
89 	if (pvp[0][0] != CANONNET)
90 	{
91 		setstat(EX_USAGE);
92 		usrerr("cannot resolve name");
93 		return (NULL);
94 	}
95 
96 	/*
97 	**  Build canonical address from pvp.
98 	*/
99 
100 	a = buildaddr(pvp, a);
101 	m = Mailer[a->q_mailer];
102 
103 	/*
104 	**  Make local copies of the host & user and then
105 	**  transport them out.
106 	*/
107 
108 	if (copyf > 0)
109 		a->q_paddr = newstr(addr);
110 	else
111 		a->q_paddr = addr;
112 
113 	if (copyf >= 0)
114 	{
115 		if (a->q_host != NULL)
116 			a->q_host = newstr(a->q_host);
117 		else
118 			a->q_host = "";
119 		if (a->q_user != a->q_paddr)
120 			a->q_user = newstr(a->q_user);
121 	}
122 
123 	/*
124 	**  Do UPPER->lower case mapping unless inhibited.
125 	*/
126 
127 	if (!bitset(M_HST_UPPER, m->m_flags))
128 		makelower(a->q_host);
129 	if (!bitset(M_USR_UPPER, m->m_flags))
130 		makelower(a->q_user);
131 
132 	/*
133 	**  Compute return value.
134 	*/
135 
136 # ifdef DEBUG
137 	if (Debug)
138 		printf("parse(\"%s\"): host \"%s\" user \"%s\" mailer %d\n",
139 		    addr, a->q_host, a->q_user, a->q_mailer);
140 # endif DEBUG
141 
142 	return (a);
143 }
144 /*
145 **  PRESCAN -- Prescan name and make it canonical
146 **
147 **	Scans a name and turns it into canonical form.  This involves
148 **	deleting blanks, comments (in parentheses), and turning the
149 **	word "at" into an at-sign ("@").  The name is copied as this
150 **	is done; it is legal to copy a name onto itself, since this
151 **	process can only make things smaller.
152 **
153 **	This routine knows about quoted strings and angle brackets.
154 **
155 **	There are certain subtleties to this routine.  The one that
156 **	comes to mind now is that backslashes on the ends of names
157 **	are silently stripped off; this is intentional.  The problem
158 **	is that some versions of sndmsg (like at LBL) set the kill
159 **	character to something other than @ when reading addresses;
160 **	so people type "csvax.eric\@berkeley" -- which screws up the
161 **	berknet mailer.
162 **
163 **	Parameters:
164 **		addr -- the name to chomp.
165 **		delim -- the delimiter for the address, normally
166 **			'\0' or ','; \0 is accepted in any case.
167 **			are moving in place; set buflim to high core.
168 **
169 **	Returns:
170 **		A pointer to a vector of tokens.
171 **		NULL on error.
172 **
173 **	Side Effects:
174 **		none.
175 */
176 
177 # define OPER		1
178 # define ATOM		2
179 # define EOTOK		3
180 # define QSTRING	4
181 # define SPACE		5
182 # define DOLLAR		6
183 # define GETONE		7
184 
185 char **
186 prescan(addr, delim)
187 	char *addr;
188 	char delim;
189 {
190 	register char *p;
191 	static char buf[MAXNAME+MAXATOM];
192 	static char *av[MAXATOM+1];
193 	char **avp;
194 	bool space;
195 	bool bslashmode;
196 	int cmntcnt;
197 	int brccnt;
198 	register char c;
199 	char *tok;
200 	register char *q;
201 	extern char *index();
202 	register int state;
203 	int nstate;
204 
205 	space = FALSE;
206 	q = buf;
207 	bslashmode = FALSE;
208 	cmntcnt = brccnt = 0;
209 	avp = av;
210 	state = OPER;
211 	for (p = addr; *p != '\0' && *p != delim; )
212 	{
213 		/* read a token */
214 		tok = q;
215 		while ((c = *p++) != '\0' && c != delim)
216 		{
217 			/* chew up special characters */
218 			*q = '\0';
219 			if (bslashmode)
220 			{
221 				c |= 0200;
222 				bslashmode = FALSE;
223 			}
224 			else if (c == '\\')
225 			{
226 				bslashmode = TRUE;
227 				continue;
228 			}
229 
230 			nstate = toktype(c);
231 			switch (state)
232 			{
233 			  case QSTRING:		/* in quoted string */
234 				if (c == '"')
235 					state = OPER;
236 				break;
237 
238 			  case ATOM:		/* regular atom */
239 				state = nstate;
240 				if (state != ATOM)
241 				{
242 					state = EOTOK;
243 					p--;
244 				}
245 				break;
246 
247 			  case GETONE:		/* grab one character */
248 				state = OPER;
249 				break;
250 
251 			  case EOTOK:		/* after atom or q-string */
252 				state = nstate;
253 				if (state == SPACE)
254 					continue;
255 				break;
256 
257 			  case SPACE:		/* linear white space */
258 				state = nstate;
259 				space = TRUE;
260 				continue;
261 
262 			  case OPER:		/* operator */
263 				if (nstate == SPACE)
264 					continue;
265 				state = nstate;
266 				break;
267 
268 			  case DOLLAR:		/* $- etc. */
269 				state = OPER;
270 				switch (c)
271 				{
272 				  case '$':		/* literal $ */
273 					break;
274 
275 				  case '+':		/* match anything */
276 					c = MATCHANY;
277 					state = GETONE;
278 					break;
279 
280 				  case '-':		/* match one token */
281 					c = MATCHONE;
282 					state = GETONE;
283 					break;
284 
285 				  case '=':		/* match one token of class */
286 					c = MATCHCLASS;
287 					state = GETONE;
288 					break;
289 
290 				  case '#':		/* canonical net name */
291 					c = CANONNET;
292 					break;
293 
294 				  case '@':		/* canonical host name */
295 					c = CANONHOST;
296 					break;
297 
298 				  case ':':		/* canonical user name */
299 					c = CANONUSER;
300 					break;
301 
302 				  default:
303 					c = '$';
304 					state = OPER;
305 					p--;
306 					break;
307 				}
308 				break;
309 
310 			  default:
311 				syserr("prescan: unknown state %d", state);
312 			}
313 
314 			if (state == OPER)
315 				space = FALSE;
316 			else if (state == EOTOK)
317 				break;
318 			if (c == '$' && delim == '\t')
319 			{
320 				state = DOLLAR;
321 				continue;
322 			}
323 
324 			/* squirrel it away */
325 			if (q >= &buf[sizeof buf - 5])
326 			{
327 				usrerr("Address too long");
328 				return (NULL);
329 			}
330 			if (space)
331 				*q++ = SPACESUB;
332 			*q++ = c;
333 
334 			/* decide whether this represents end of token */
335 			if (state == OPER)
336 				break;
337 		}
338 		if (c == '\0' || c == delim)
339 			p--;
340 
341 		/* new token */
342 		if (tok == q)
343 			continue;
344 		*q++ = '\0';
345 
346 		c = tok[0];
347 		if (c == '(')
348 		{
349 			cmntcnt++;
350 			continue;
351 		}
352 		else if (c == ')')
353 		{
354 			if (cmntcnt <= 0)
355 			{
356 				usrerr("Unbalanced ')'");
357 				return (NULL);
358 			}
359 			else
360 			{
361 				cmntcnt--;
362 				continue;
363 			}
364 		}
365 		else if (cmntcnt > 0)
366 			continue;
367 
368 		*avp++ = tok;
369 
370 		/* we prefer <> specs */
371 		if (c == '<')
372 		{
373 			if (brccnt < 0)
374 			{
375 				usrerr("multiple < spec");
376 				return (NULL);
377 			}
378 			brccnt++;
379 			space = FALSE;
380 			if (brccnt == 1)
381 			{
382 				/* we prefer using machine readable name */
383 				q = buf;
384 				*q = '\0';
385 				avp = av;
386 				continue;
387 			}
388 		}
389 		else if (c == '>')
390 		{
391 			if (brccnt <= 0)
392 			{
393 				usrerr("Unbalanced `>'");
394 				return (NULL);
395 			}
396 			else
397 				brccnt--;
398 			if (brccnt <= 0)
399 			{
400 				brccnt = -1;
401 				continue;
402 			}
403 		}
404 
405 		/*
406 		**  Turn "at" into "@",
407 		**	but only if "at" is a word.
408 		*/
409 
410 		if (lower(tok[0]) == 'a' && lower(tok[1]) == 't' && tok[2] == '\0')
411 		{
412 			tok[0] = '@';
413 			tok[1] = '\0';
414 		}
415 	}
416 	*avp = NULL;
417 	if (cmntcnt > 0)
418 		usrerr("Unbalanced '('");
419 	else if (brccnt > 0)
420 		usrerr("Unbalanced '<'");
421 	else if (state == QSTRING)
422 		usrerr("Unbalanced '\"'");
423 	else if (av[0] != NULL)
424 		return (av);
425 	return (NULL);
426 }
427 /*
428 **  TOKTYPE -- return token type
429 **
430 **	Parameters:
431 **		c -- the character in question.
432 **
433 **	Returns:
434 **		Its type.
435 **
436 **	Side Effects:
437 **		none.
438 */
439 
440 toktype(c)
441 	register char c;
442 {
443 	static char buf[50];
444 	static bool firstime = TRUE;
445 
446 	if (firstime)
447 	{
448 		firstime = FALSE;
449 		expand("$o", buf, &buf[sizeof buf - 1]);
450 		strcat(buf, DELIMCHARS);
451 	}
452 	if (isspace(c))
453 		return (SPACE);
454 	if (iscntrl(c) || index(buf, c) != NULL)
455 		return (OPER);
456 	return (ATOM);
457 }
458 /*
459 **  REWRITE -- apply rewrite rules to token vector.
460 **
461 **	Parameters:
462 **		pvp -- pointer to token vector.
463 **
464 **	Returns:
465 **		none.
466 **
467 **	Side Effects:
468 **		pvp is modified.
469 */
470 
471 struct match
472 {
473 	char	**firsttok;	/* first token matched */
474 	char	**lasttok;	/* last token matched */
475 	char	name;		/* name of parameter */
476 };
477 
478 # define MAXMATCH	8	/* max params per rewrite */
479 
480 
481 rewrite(pvp)
482 	char **pvp;
483 {
484 	register char *ap;		/* address pointer */
485 	register char *rp;		/* rewrite pointer */
486 	register char **avp;		/* address vector pointer */
487 	register char **rvp;		/* rewrite vector pointer */
488 	struct rewrite *rwr;
489 	struct match mlist[MAXMATCH];
490 	char *npvp[MAXATOM+1];		/* temporary space for rebuild */
491 	extern bool sameword();
492 
493 # ifdef DEBUGX
494 	if (Debug)
495 	{
496 		printf("rewrite: original pvp:\n");
497 		printav(pvp);
498 	}
499 # endif DEBUGX
500 
501 	/*
502 	**  Run through the list of rewrite rules, applying
503 	**	any that match.
504 	*/
505 
506 	for (rwr = RewriteRules; rwr != NULL; )
507 	{
508 # ifdef DEBUGX
509 		if (Debug)
510 		{
511 			printf("-----trying rule:\n");
512 			printav(rwr->r_lhs);
513 		}
514 # endif DEBUGX
515 
516 		/* try to match on this rule */
517 		clrmatch(mlist);
518 		for (rvp = rwr->r_lhs, avp = pvp; *avp != NULL; )
519 		{
520 			ap = *avp;
521 			rp = *rvp;
522 
523 			if (rp == NULL)
524 			{
525 				/* end-of-pattern before end-of-address */
526 				goto fail;
527 			}
528 
529 			switch (*rp)
530 			{
531 				register STAB *s;
532 				register int class;
533 
534 			  case MATCHONE:
535 				/* match exactly one token */
536 				setmatch(mlist, rp[1], avp, avp);
537 				break;
538 
539 			  case MATCHANY:
540 				/* match any number of tokens */
541 				setmatch(mlist, rp[1], NULL, avp);
542 				break;
543 
544 			  case MATCHCLASS:
545 				/* match any token in a class */
546 				class = rp[1];
547 				if (!isalpha(class))
548 					goto fail;
549 				if (isupper(class))
550 					class -= 'A';
551 				else
552 					class -= 'a';
553 				s = stab(ap, ST_FIND);
554 				if (s == NULL || (s->s_class & (1 << class)) == 0)
555 					goto fail;
556 				break;
557 
558 			  default:
559 				/* must have exact match */
560 				if (!sameword(rp, ap))
561 					goto fail;
562 				break;
563 			}
564 
565 			/* successful match on this token */
566 			avp++;
567 			rvp++;
568 			continue;
569 
570 		  fail:
571 			/* match failed -- back up */
572 			while (--rvp >= rwr->r_lhs)
573 			{
574 				rp = *rvp;
575 				if (*rp == MATCHANY)
576 					break;
577 
578 				/* can't extend match: back up everything */
579 				avp--;
580 
581 				if (*rp == MATCHONE)
582 				{
583 					/* undo binding */
584 					setmatch(mlist, rp[1], NULL, NULL);
585 				}
586 			}
587 
588 			if (rvp < rwr->r_lhs)
589 			{
590 				/* total failure to match */
591 				break;
592 			}
593 		}
594 
595 		/*
596 		**  See if we successfully matched
597 		*/
598 
599 		if (rvp >= rwr->r_lhs && *rvp == NULL)
600 		{
601 # ifdef DEBUGX
602 			if (Debug)
603 			{
604 				printf("-----rule matches:\n");
605 				printav(rwr->r_rhs);
606 			}
607 # endif DEBUGX
608 
609 			/* substitute */
610 			for (rvp = rwr->r_rhs, avp = npvp; *rvp != NULL; rvp++)
611 			{
612 				rp = *rvp;
613 				if (*rp == MATCHANY)
614 				{
615 					register struct match *m;
616 					register char **pp;
617 					extern struct match *findmatch();
618 
619 					m = findmatch(mlist, rp[1]);
620 					if (m != NULL)
621 					{
622 						pp = m->firsttok;
623 						do
624 						{
625 							*avp++ = *pp;
626 						} while (pp++ != m->lasttok);
627 					}
628 				}
629 				else
630 					*avp++ = rp;
631 			}
632 			*avp++ = NULL;
633 			bmove(npvp, pvp, (avp - npvp) * sizeof *avp);
634 # ifdef DEBUG
635 			if (Debug)
636 			{
637 				char **vp;
638 
639 				printf("rewritten as `");
640 				for (vp = pvp; *vp != NULL; vp++)
641 					xputs(*vp);
642 				printf("'\n");
643 			}
644 # endif DEBUG
645 			if (pvp[0][0] == CANONNET)
646 				break;
647 		}
648 		else
649 		{
650 # ifdef DEBUGX
651 			if (Debug)
652 				printf("----- rule fails\n");
653 # endif DEBUGX
654 			rwr = rwr->r_next;
655 		}
656 	}
657 }
658 /*
659 **  SETMATCH -- set parameter value in match vector
660 **
661 **	Parameters:
662 **		mlist -- list of match values.
663 **		name -- the character name of this parameter.
664 **		first -- the first location of the replacement.
665 **		last -- the last location of the replacement.
666 **
667 **		If last == NULL, delete this entry.
668 **		If first == NULL, extend this entry (or add it if
669 **			it does not exist).
670 **
671 **	Returns:
672 **		nothing.
673 **
674 **	Side Effects:
675 **		munges with mlist.
676 */
677 
678 setmatch(mlist, name, first, last)
679 	struct match *mlist;
680 	char name;
681 	char **first;
682 	char **last;
683 {
684 	register struct match *m;
685 	struct match *nullm = NULL;
686 
687 	for (m = mlist; m < &mlist[MAXMATCH]; m++)
688 	{
689 		if (m->name == name)
690 			break;
691 		if (m->name == '\0')
692 			nullm = m;
693 	}
694 
695 	if (m >= &mlist[MAXMATCH])
696 		m = nullm;
697 
698 	if (last == NULL)
699 	{
700 		m->name = '\0';
701 		return;
702 	}
703 
704 	if (m->name == '\0')
705 	{
706 		if (first == NULL)
707 			m->firsttok = last;
708 		else
709 			m->firsttok = first;
710 	}
711 	m->name = name;
712 	m->lasttok = last;
713 }
714 /*
715 **  FINDMATCH -- find match in mlist
716 **
717 **	Parameters:
718 **		mlist -- list to search.
719 **		name -- name to find.
720 **
721 **	Returns:
722 **		pointer to match structure.
723 **		NULL if no match.
724 **
725 **	Side Effects:
726 **		none.
727 */
728 
729 struct match *
730 findmatch(mlist, name)
731 	struct match *mlist;
732 	char name;
733 {
734 	register struct match *m;
735 
736 	for (m = mlist; m < &mlist[MAXMATCH]; m++)
737 	{
738 		if (m->name == name)
739 			return (m);
740 	}
741 
742 	return (NULL);
743 }
744 /*
745 **  CLRMATCH -- clear match list
746 **
747 **	Parameters:
748 **		mlist -- list to clear.
749 **
750 **	Returns:
751 **		none.
752 **
753 **	Side Effects:
754 **		mlist is cleared.
755 */
756 
757 clrmatch(mlist)
758 	struct match *mlist;
759 {
760 	register struct match *m;
761 
762 	for (m = mlist; m < &mlist[MAXMATCH]; m++)
763 		m->name = '\0';
764 }
765 /*
766 **  BUILDADDR -- build address from token vector.
767 **
768 **	Parameters:
769 **		tv -- token vector.
770 **		a -- pointer to address descriptor to fill.
771 **			If NULL, one will be allocated.
772 **
773 **	Returns:
774 **		'a'
775 **
776 **	Side Effects:
777 **		fills in 'a'
778 */
779 
780 ADDRESS *
781 buildaddr(tv, a)
782 	register char **tv;
783 	register ADDRESS *a;
784 {
785 	register int i;
786 	static char buf[MAXNAME];
787 	struct mailer **mp;
788 	register struct mailer *m;
789 	extern char *xalloc();
790 
791 	if (a == NULL)
792 		a = (ADDRESS *) xalloc(sizeof *a);
793 	a->q_flags = 0;
794 
795 	/* figure out what net/mailer to use */
796 	if (**tv != CANONNET)
797 		syserr("buildaddr: no net");
798 	tv++;
799 	for (mp = Mailer, i = 0; (m = *mp++) != NULL; i++)
800 	{
801 		if (strcmp(m->m_name, *tv) == 0)
802 			break;
803 	}
804 	if (m == NULL)
805 		syserr("buildaddr: unknown net %s", *tv);
806 	a->q_mailer = i;
807 
808 	/* figure out what host (if any) */
809 	tv++;
810 	if (!bitset(M_NOHOST, m->m_flags))
811 	{
812 		if (**tv != CANONHOST)
813 			syserr("buildaddr: no host");
814 		tv++;
815 		a->q_host = *tv;
816 		tv++;
817 	}
818 	else
819 		a->q_host = NULL;
820 
821 	/* figure out the user */
822 	if (**tv != CANONUSER)
823 		syserr("buildaddr: no user");
824 	buf[0] = '\0';
825 	while (**++tv != NULL)
826 		strcat(buf, *tv);
827 	a->q_user = buf;
828 
829 	return (a);
830 }
831 /*
832 **  SAMEADDR -- Determine if two addresses are the same
833 **
834 **	This is not just a straight comparison -- if the mailer doesn't
835 **	care about the host we just ignore it, etc.
836 **
837 **	Parameters:
838 **		a, b -- pointers to the internal forms to compare.
839 **		wildflg -- if TRUE, 'a' may have no user specified,
840 **			in which case it is to match anything.
841 **
842 **	Returns:
843 **		TRUE -- they represent the same mailbox.
844 **		FALSE -- they don't.
845 **
846 **	Side Effects:
847 **		none.
848 */
849 
850 bool
851 sameaddr(a, b, wildflg)
852 	register ADDRESS *a;
853 	register ADDRESS *b;
854 	bool wildflg;
855 {
856 	/* if they don't have the same mailer, forget it */
857 	if (a->q_mailer != b->q_mailer)
858 		return (FALSE);
859 
860 	/* if the user isn't the same, we can drop out */
861 	if ((!wildflg || a->q_user[0] != '\0') && strcmp(a->q_user, b->q_user) != 0)
862 		return (FALSE);
863 
864 	/* if the mailer ignores hosts, we have succeeded! */
865 	if (bitset(M_NOHOST, Mailer[a->q_mailer]->m_flags))
866 		return (TRUE);
867 
868 	/* otherwise compare hosts (but be careful for NULL ptrs) */
869 	if (a->q_host == NULL || b->q_host == NULL)
870 		return (FALSE);
871 	if (strcmp(a->q_host, b->q_host) != 0)
872 		return (FALSE);
873 
874 	return (TRUE);
875 }
876 /*
877 **  PRINTADDR -- print address (for debugging)
878 **
879 **	Parameters:
880 **		a -- the address to print
881 **		follow -- follow the q_next chain.
882 **
883 **	Returns:
884 **		none.
885 **
886 **	Side Effects:
887 **		none.
888 */
889 
890 printaddr(a, follow)
891 	register ADDRESS *a;
892 	bool follow;
893 {
894 	while (a != NULL)
895 	{
896 		printf("addr@%x: ", a);
897 		fflush(stdout);
898 		printf("%s: mailer %d (%s), host `%s', user `%s'\n", a->q_paddr,
899 		       a->q_mailer, Mailer[a->q_mailer]->m_name, a->q_host, a->q_user);
900 		printf("\tnext=%x flags=%o, rmailer %d\n", a->q_next,
901 		       a->q_flags, a->q_rmailer);
902 
903 		if (!follow)
904 			return;
905 		a = a->q_next;
906 	}
907 }
908