1 # include "sendmail.h"
2 
3 static char	SccsId[] = "@(#)parseaddr.c	3.25	09/14/81";
4 
5 /*
6 **  PARSE -- Parse an address
7 **
8 **	Parses an address and breaks it up into three parts: a
9 **	net to transmit the message on, the host to transmit it
10 **	to, and a user on that host.  These are loaded into an
11 **	ADDRESS header with the values squirreled away if necessary.
12 **	The "user" part may not be a real user; the process may
13 **	just reoccur on that machine.  For example, on a machine
14 **	with an arpanet connection, the address
15 **		csvax.bill@berkeley
16 **	will break up to a "user" of 'csvax.bill' and a host
17 **	of 'berkeley' -- to be transmitted over the arpanet.
18 **
19 **	Parameters:
20 **		addr -- the address to parse.
21 **		a -- a pointer to the address descriptor buffer.
22 **			If NULL, a header will be created.
23 **		copyf -- determines what shall be copied:
24 **			-1 -- don't copy anything.  The printname
25 **				(q_paddr) is just addr, and the
26 **				user & host are allocated internally
27 **				to parse.
28 **			0 -- copy out the parsed user & host, but
29 **				don't copy the printname.
30 **			+1 -- copy everything.
31 **
32 **	Returns:
33 **		A pointer to the address descriptor header (`a' if
34 **			`a' is non-NULL).
35 **		NULL on error.
36 **
37 **	Side Effects:
38 **		none
39 */
40 
41 # define DELIMCHARS	"$()<>,;\\\"\r\n"	/* word delimiters */
42 
43 ADDRESS *
44 parse(addr, a, copyf)
45 	char *addr;
46 	register ADDRESS *a;
47 	int copyf;
48 {
49 	register char **pvp;
50 	register struct mailer *m;
51 	extern char **prescan();
52 	extern ADDRESS *buildaddr();
53 
54 	/*
55 	**  Initialize and prescan address.
56 	*/
57 
58 	To = addr;
59 # ifdef DEBUG
60 	if (Debug)
61 		printf("\n--parse(%s)\n", addr);
62 # endif DEBUG
63 
64 	pvp = prescan(addr, '\0');
65 	if (pvp == NULL)
66 		return (NULL);
67 
68 	/*
69 	**  Apply rewriting rules.
70 	*/
71 
72 	rewrite(pvp, 0);
73 
74 	/*
75 	**  See if we resolved to a real mailer.
76 	*/
77 
78 	if (pvp[0][0] != CANONNET)
79 	{
80 		setstat(EX_USAGE);
81 		usrerr("cannot resolve name");
82 		return (NULL);
83 	}
84 
85 	/*
86 	**  Build canonical address from pvp.
87 	*/
88 
89 	a = buildaddr(pvp, a);
90 	if (a == NULL)
91 		return (NULL);
92 	m = Mailer[a->q_mailer];
93 
94 	/*
95 	**  Make local copies of the host & user and then
96 	**  transport them out.
97 	*/
98 
99 	if (copyf > 0)
100 		a->q_paddr = newstr(addr);
101 	else
102 		a->q_paddr = addr;
103 
104 	if (copyf >= 0)
105 	{
106 		if (a->q_host != NULL)
107 			a->q_host = newstr(a->q_host);
108 		else
109 			a->q_host = "";
110 		if (a->q_user != a->q_paddr)
111 			a->q_user = newstr(a->q_user);
112 	}
113 
114 	/*
115 	**  Do UPPER->lower case mapping unless inhibited.
116 	*/
117 
118 	if (!bitset(M_HST_UPPER, m->m_flags))
119 		makelower(a->q_host);
120 	if (!bitset(M_USR_UPPER, m->m_flags))
121 		makelower(a->q_user);
122 
123 	/*
124 	**  Compute return value.
125 	*/
126 
127 # ifdef DEBUG
128 	if (Debug)
129 		printf("parse(\"%s\"): host \"%s\" user \"%s\" mailer %d\n",
130 		    addr, a->q_host, a->q_user, a->q_mailer);
131 # endif DEBUG
132 
133 	return (a);
134 }
135 /*
136 **  PRESCAN -- Prescan name and make it canonical
137 **
138 **	Scans a name and turns it into canonical form.  This involves
139 **	deleting blanks, comments (in parentheses), and turning the
140 **	word "at" into an at-sign ("@").  The name is copied as this
141 **	is done; it is legal to copy a name onto itself, since this
142 **	process can only make things smaller.
143 **
144 **	This routine knows about quoted strings and angle brackets.
145 **
146 **	There are certain subtleties to this routine.  The one that
147 **	comes to mind now is that backslashes on the ends of names
148 **	are silently stripped off; this is intentional.  The problem
149 **	is that some versions of sndmsg (like at LBL) set the kill
150 **	character to something other than @ when reading addresses;
151 **	so people type "csvax.eric\@berkeley" -- which screws up the
152 **	berknet mailer.
153 **
154 **	Parameters:
155 **		addr -- the name to chomp.
156 **		delim -- the delimiter for the address, normally
157 **			'\0' or ','; \0 is accepted in any case.
158 **			are moving in place; set buflim to high core.
159 **
160 **	Returns:
161 **		A pointer to a vector of tokens.
162 **		NULL on error.
163 **
164 **	Side Effects:
165 **		none.
166 */
167 
168 # define OPER		1
169 # define ATOM		2
170 # define EOTOK		3
171 # define QSTRING	4
172 # define SPACE		5
173 # define DOLLAR		6
174 # define GETONE		7
175 
176 char **
177 prescan(addr, delim)
178 	char *addr;
179 	char delim;
180 {
181 	register char *p;
182 	static char buf[MAXNAME+MAXATOM];
183 	static char *av[MAXATOM+1];
184 	char **avp;
185 	bool bslashmode;
186 	int cmntcnt;
187 	int brccnt;
188 	register char c;
189 	char *tok;
190 	register char *q;
191 	register int state;
192 	int nstate;
193 	extern char lower();
194 
195 	q = buf;
196 	bslashmode = FALSE;
197 	cmntcnt = brccnt = 0;
198 	avp = av;
199 	state = OPER;
200 	for (p = addr; *p != '\0' && *p != delim; )
201 	{
202 		/* read a token */
203 		tok = q;
204 		while ((c = *p++) != '\0' && c != delim)
205 		{
206 			/* chew up special characters */
207 			c &= ~0200;
208 			*q = '\0';
209 			if (bslashmode)
210 			{
211 				c |= 0200;
212 				bslashmode = FALSE;
213 			}
214 			else if (c == '\\')
215 			{
216 				bslashmode = TRUE;
217 				continue;
218 			}
219 			else if (c == '"')
220 			{
221 				if (state == QSTRING)
222 					state = OPER;
223 				else
224 					state = QSTRING;
225 				break;
226 			}
227 
228 			nstate = toktype(c);
229 			switch (state)
230 			{
231 			  case QSTRING:		/* in quoted string */
232 				break;
233 
234 			  case ATOM:		/* regular atom */
235 				/* state = nstate; */
236 				if (nstate != ATOM)
237 				{
238 					state = EOTOK;
239 					p--;
240 				}
241 				break;
242 
243 			  case GETONE:		/* grab one character */
244 				state = OPER;
245 				break;
246 
247 			  case EOTOK:		/* after atom or q-string */
248 				state = nstate;
249 				if (state == SPACE)
250 					continue;
251 				break;
252 
253 			  case SPACE:		/* linear white space */
254 				state = nstate;
255 				break;
256 
257 			  case OPER:		/* operator */
258 				if (nstate == SPACE)
259 					continue;
260 				state = nstate;
261 				break;
262 
263 			  case DOLLAR:		/* $- etc. */
264 				state = OPER;
265 				switch (c)
266 				{
267 				  case '$':		/* literal $ */
268 					break;
269 
270 				  case '+':		/* match anything */
271 					c = MATCHANY;
272 					state = GETONE;
273 					break;
274 
275 				  case '-':		/* match one token */
276 					c = MATCHONE;
277 					state = GETONE;
278 					break;
279 
280 				  case '=':		/* match one token of class */
281 					c = MATCHCLASS;
282 					state = GETONE;
283 					break;
284 
285 				  case '#':		/* canonical net name */
286 					c = CANONNET;
287 					break;
288 
289 				  case '@':		/* canonical host name */
290 					c = CANONHOST;
291 					break;
292 
293 				  case ':':		/* canonical user name */
294 					c = CANONUSER;
295 					break;
296 
297 				  default:
298 					c = '$';
299 					state = OPER;
300 					p--;
301 					break;
302 				}
303 				break;
304 
305 			  default:
306 				syserr("prescan: unknown state %d", state);
307 			}
308 
309 			if (state == EOTOK || state == SPACE)
310 				break;
311 			if (c == '$' && delim == '\t')
312 			{
313 				state = DOLLAR;
314 				continue;
315 			}
316 
317 			/* squirrel it away */
318 			if (q >= &buf[sizeof buf - 5])
319 			{
320 				usrerr("Address too long");
321 				return (NULL);
322 			}
323 			*q++ = c;
324 
325 			/* decide whether this represents end of token */
326 			if (state == OPER)
327 				break;
328 		}
329 		if (c == '\0' || c == delim)
330 			p--;
331 
332 		/* new token */
333 		if (tok == q)
334 			continue;
335 		*q++ = '\0';
336 
337 		c = tok[0];
338 		if (c == '(')
339 		{
340 			cmntcnt++;
341 			continue;
342 		}
343 		else if (c == ')')
344 		{
345 			if (cmntcnt <= 0)
346 			{
347 				usrerr("Unbalanced ')'");
348 				return (NULL);
349 			}
350 			else
351 			{
352 				cmntcnt--;
353 				continue;
354 			}
355 		}
356 		else if (cmntcnt > 0)
357 			continue;
358 
359 		if (avp >= &av[MAXATOM])
360 		{
361 			syserr("prescan: too many tokens");
362 			return (NULL);
363 		}
364 		*avp++ = tok;
365 
366 		/* we prefer <> specs */
367 		if (c == '<')
368 		{
369 			if (brccnt < 0)
370 			{
371 				usrerr("multiple < spec");
372 				return (NULL);
373 			}
374 			brccnt++;
375 			if (brccnt == 1)
376 			{
377 				/* we prefer using machine readable name */
378 				q = buf;
379 				*q = '\0';
380 				avp = av;
381 				continue;
382 			}
383 		}
384 		else if (c == '>')
385 		{
386 			if (brccnt <= 0)
387 			{
388 				usrerr("Unbalanced `>'");
389 				return (NULL);
390 			}
391 			else
392 				brccnt--;
393 			if (brccnt <= 0)
394 			{
395 				brccnt = -1;
396 				continue;
397 			}
398 		}
399 	}
400 	*avp = NULL;
401 	if (cmntcnt > 0)
402 		usrerr("Unbalanced '('");
403 	else if (brccnt > 0)
404 		usrerr("Unbalanced '<'");
405 	else if (state == QSTRING)
406 		usrerr("Unbalanced '\"'");
407 	else if (av[0] != NULL)
408 		return (av);
409 	return (NULL);
410 }
411 /*
412 **  TOKTYPE -- return token type
413 **
414 **	Parameters:
415 **		c -- the character in question.
416 **
417 **	Returns:
418 **		Its type.
419 **
420 **	Side Effects:
421 **		none.
422 */
423 
424 toktype(c)
425 	register char c;
426 {
427 	static char buf[50];
428 	static bool firstime = TRUE;
429 
430 	if (firstime)
431 	{
432 		firstime = FALSE;
433 		(void) expand("$o", buf, &buf[sizeof buf - 1]);
434 		strcat(buf, DELIMCHARS);
435 	}
436 	if (!isascii(c))
437 		return (ATOM);
438 	if (isspace(c))
439 		return (SPACE);
440 	if (iscntrl(c) || index(buf, c) != NULL)
441 		return (OPER);
442 	return (ATOM);
443 }
444 /*
445 **  REWRITE -- apply rewrite rules to token vector.
446 **
447 **	Parameters:
448 **		pvp -- pointer to token vector.
449 **
450 **	Returns:
451 **		none.
452 **
453 **	Side Effects:
454 **		pvp is modified.
455 */
456 
457 struct match
458 {
459 	char	**firsttok;	/* first token matched */
460 	char	**lasttok;	/* last token matched */
461 	char	name;		/* name of parameter */
462 };
463 
464 # define MAXMATCH	8	/* max params per rewrite */
465 
466 
467 rewrite(pvp, ruleset)
468 	char **pvp;
469 	int ruleset;
470 {
471 	register char *ap;		/* address pointer */
472 	register char *rp;		/* rewrite pointer */
473 	register char **avp;		/* address vector pointer */
474 	register char **rvp;		/* rewrite vector pointer */
475 	struct rewrite *rwr;
476 	struct match mlist[MAXMATCH];
477 	char *npvp[MAXATOM+1];		/* temporary space for rebuild */
478 	extern bool sameword();
479 
480 # ifdef DEBUG
481 	if (Debug > 9)
482 	{
483 		printf("rewrite: original pvp:\n");
484 		printav(pvp);
485 	}
486 # endif DEBUG
487 
488 	/*
489 	**  Run through the list of rewrite rules, applying
490 	**	any that match.
491 	*/
492 
493 	for (rwr = RewriteRules[ruleset]; rwr != NULL; )
494 	{
495 # ifdef DEBUG
496 		if (Debug > 10)
497 		{
498 			printf("-----trying rule:\n");
499 			printav(rwr->r_lhs);
500 		}
501 # endif DEBUG
502 
503 		/* try to match on this rule */
504 		clrmatch(mlist);
505 		for (rvp = rwr->r_lhs, avp = pvp; *avp != NULL; )
506 		{
507 			ap = *avp;
508 			rp = *rvp;
509 
510 			if (rp == NULL)
511 			{
512 				/* end-of-pattern before end-of-address */
513 				goto fail;
514 			}
515 
516 			switch (*rp)
517 			{
518 				register STAB *s;
519 				register int class;
520 
521 			  case MATCHONE:
522 				/* match exactly one token */
523 				setmatch(mlist, rp[1], avp, avp);
524 				break;
525 
526 			  case MATCHANY:
527 				/* match any number of tokens */
528 				setmatch(mlist, rp[1], (char **) NULL, avp);
529 				break;
530 
531 			  case MATCHCLASS:
532 				/* match any token in a class */
533 				class = rp[1];
534 				if (!isalpha(class))
535 					goto fail;
536 				if (isupper(class))
537 					class -= 'A';
538 				else
539 					class -= 'a';
540 				s = stab(ap, ST_CLASS, ST_FIND);
541 				if (s == NULL || (s->s_class & (1 << class)) == 0)
542 					goto fail;
543 				break;
544 
545 			  default:
546 				/* must have exact match */
547 				if (!sameword(rp, ap))
548 					goto fail;
549 				break;
550 			}
551 
552 			/* successful match on this token */
553 			avp++;
554 			rvp++;
555 			continue;
556 
557 		  fail:
558 			/* match failed -- back up */
559 			while (--rvp >= rwr->r_lhs)
560 			{
561 				rp = *rvp;
562 				if (*rp == MATCHANY)
563 					break;
564 
565 				/* can't extend match: back up everything */
566 				avp--;
567 
568 				if (*rp == MATCHONE)
569 				{
570 					/* undo binding */
571 					setmatch(mlist, rp[1], (char **) NULL, (char **) NULL);
572 				}
573 			}
574 
575 			if (rvp < rwr->r_lhs)
576 			{
577 				/* total failure to match */
578 				break;
579 			}
580 		}
581 
582 		/*
583 		**  See if we successfully matched
584 		*/
585 
586 		if (rvp >= rwr->r_lhs && *rvp == NULL)
587 		{
588 # ifdef DEBUG
589 			if (Debug > 10)
590 			{
591 				printf("-----rule matches:\n");
592 				printav(rwr->r_rhs);
593 			}
594 # endif DEBUG
595 
596 			/* substitute */
597 			for (rvp = rwr->r_rhs, avp = npvp; *rvp != NULL; rvp++)
598 			{
599 				rp = *rvp;
600 				if (*rp == MATCHANY)
601 				{
602 					register struct match *m;
603 					register char **pp;
604 					extern struct match *findmatch();
605 
606 					m = findmatch(mlist, rp[1]);
607 					if (m != NULL)
608 					{
609 						pp = m->firsttok;
610 						do
611 						{
612 							if (avp >= &npvp[MAXATOM])
613 							{
614 								syserr("rewrite: expansion too long");
615 								return;
616 							}
617 							*avp++ = *pp;
618 						} while (pp++ != m->lasttok);
619 					}
620 				}
621 				else
622 				{
623 					if (avp >= &npvp[MAXATOM])
624 					{
625 						syserr("rewrite: expansion too long");
626 						return;
627 					}
628 					*avp++ = rp;
629 				}
630 			}
631 			*avp++ = NULL;
632 			bmove((char *) npvp, (char *) pvp, (avp - npvp) * sizeof *avp);
633 # ifdef DEBUG
634 			if (Debug > 3)
635 			{
636 				char **vp;
637 
638 				printf("rewritten as `");
639 				for (vp = pvp; *vp != NULL; vp++)
640 				{
641 					if (vp != pvp)
642 						printf("_");
643 					xputs(*vp);
644 				}
645 				printf("'\n");
646 			}
647 # endif DEBUG
648 			if (pvp[0][0] == CANONNET)
649 				break;
650 		}
651 		else
652 		{
653 # ifdef DEBUG
654 			if (Debug > 10)
655 				printf("----- rule fails\n");
656 # endif DEBUG
657 			rwr = rwr->r_next;
658 		}
659 	}
660 }
661 /*
662 **  SETMATCH -- set parameter value in match vector
663 **
664 **	Parameters:
665 **		mlist -- list of match values.
666 **		name -- the character name of this parameter.
667 **		first -- the first location of the replacement.
668 **		last -- the last location of the replacement.
669 **
670 **		If last == NULL, delete this entry.
671 **		If first == NULL, extend this entry (or add it if
672 **			it does not exist).
673 **
674 **	Returns:
675 **		nothing.
676 **
677 **	Side Effects:
678 **		munges with mlist.
679 */
680 
681 setmatch(mlist, name, first, last)
682 	struct match *mlist;
683 	char name;
684 	char **first;
685 	char **last;
686 {
687 	register struct match *m;
688 	struct match *nullm = NULL;
689 
690 	for (m = mlist; m < &mlist[MAXMATCH]; m++)
691 	{
692 		if (m->name == name)
693 			break;
694 		if (m->name == '\0')
695 			nullm = m;
696 	}
697 
698 	if (m >= &mlist[MAXMATCH])
699 		m = nullm;
700 
701 	if (last == NULL)
702 	{
703 		m->name = '\0';
704 		return;
705 	}
706 
707 	if (m->name == '\0')
708 	{
709 		if (first == NULL)
710 			m->firsttok = last;
711 		else
712 			m->firsttok = first;
713 	}
714 	m->name = name;
715 	m->lasttok = last;
716 }
717 /*
718 **  FINDMATCH -- find match in mlist
719 **
720 **	Parameters:
721 **		mlist -- list to search.
722 **		name -- name to find.
723 **
724 **	Returns:
725 **		pointer to match structure.
726 **		NULL if no match.
727 **
728 **	Side Effects:
729 **		none.
730 */
731 
732 struct match *
733 findmatch(mlist, name)
734 	struct match *mlist;
735 	char name;
736 {
737 	register struct match *m;
738 
739 	for (m = mlist; m < &mlist[MAXMATCH]; m++)
740 	{
741 		if (m->name == name)
742 			return (m);
743 	}
744 
745 	return (NULL);
746 }
747 /*
748 **  CLRMATCH -- clear match list
749 **
750 **	Parameters:
751 **		mlist -- list to clear.
752 **
753 **	Returns:
754 **		none.
755 **
756 **	Side Effects:
757 **		mlist is cleared.
758 */
759 
760 clrmatch(mlist)
761 	struct match *mlist;
762 {
763 	register struct match *m;
764 
765 	for (m = mlist; m < &mlist[MAXMATCH]; m++)
766 		m->name = '\0';
767 }
768 /*
769 **  BUILDADDR -- build address from token vector.
770 **
771 **	Parameters:
772 **		tv -- token vector.
773 **		a -- pointer to address descriptor to fill.
774 **			If NULL, one will be allocated.
775 **
776 **	Returns:
777 **		NULL if there was an error.
778 **		'a' otherwise.
779 **
780 **	Side Effects:
781 **		fills in 'a'
782 */
783 
784 ADDRESS *
785 buildaddr(tv, a)
786 	register char **tv;
787 	register ADDRESS *a;
788 {
789 	register int i;
790 	static char buf[MAXNAME];
791 	struct mailer **mp;
792 	register struct mailer *m;
793 
794 	if (a == NULL)
795 		a = (ADDRESS *) xalloc(sizeof *a);
796 	a->q_flags = 0;
797 	a->q_home = NULL;
798 
799 	/* figure out what net/mailer to use */
800 	if (**tv != CANONNET)
801 	{
802 		syserr("buildaddr: no net");
803 		return (NULL);
804 	}
805 	tv++;
806 	if (strcmp(*tv, "error") == 0)
807 	{
808 		if (**++tv != CANONUSER)
809 			syserr("buildaddr: error: no user");
810 		buf[0] = '\0';
811 		while (*++tv != NULL)
812 		{
813 			if (buf[0] != '\0')
814 				strcat(buf, " ");
815 			strcat(buf, *tv);
816 		}
817 		usrerr(buf);
818 		return (NULL);
819 	}
820 	for (mp = Mailer, i = 0; (m = *mp++) != NULL; i++)
821 	{
822 		if (strcmp(m->m_name, *tv) == 0)
823 			break;
824 	}
825 	if (m == NULL)
826 	{
827 		syserr("buildaddr: unknown net %s", *tv);
828 		return (NULL);
829 	}
830 	a->q_mailer = i;
831 
832 	/* figure out what host (if any) */
833 	tv++;
834 	if (!bitset(M_LOCAL, m->m_flags))
835 	{
836 		if (**tv != CANONHOST)
837 		{
838 			syserr("buildaddr: no host");
839 			return (NULL);
840 		}
841 		tv++;
842 		a->q_host = *tv;
843 		tv++;
844 	}
845 	else
846 		a->q_host = NULL;
847 
848 	/* figure out the user */
849 	if (**tv != CANONUSER)
850 	{
851 		syserr("buildaddr: no user");
852 		return (NULL);
853 	}
854 	cataddr(++tv, buf, sizeof buf);
855 	a->q_user = buf;
856 
857 	return (a);
858 }
859 /*
860 **  CATADDR -- concatenate pieces of addresses (putting in <LWSP> subs)
861 **
862 **	Parameters:
863 **		pvp -- parameter vector to rebuild.
864 **		buf -- buffer to build the string into.
865 **		sz -- size of buf.
866 **
867 **	Returns:
868 **		none.
869 **
870 **	Side Effects:
871 **		Destroys buf.
872 */
873 
874 cataddr(pvp, buf, sz)
875 	char **pvp;
876 	char *buf;
877 	register int sz;
878 {
879 	bool oatomtok = FALSE;
880 	bool natomtok = FALSE;
881 	register int i;
882 	register char *p;
883 
884 	p = buf;
885 	sz--;
886 	while (*pvp != NULL && (i = strlen(*pvp)) < sz)
887 	{
888 		natomtok = (toktype(**pvp) == ATOM);
889 		if (oatomtok && natomtok)
890 			*p++ = SPACESUB;
891 		(void) strcpy(p, *pvp);
892 		oatomtok = natomtok;
893 		p += i;
894 		sz -= i;
895 		pvp++;
896 	}
897 	*p = '\0';
898 }
899 /*
900 **  SAMEADDR -- Determine if two addresses are the same
901 **
902 **	This is not just a straight comparison -- if the mailer doesn't
903 **	care about the host we just ignore it, etc.
904 **
905 **	Parameters:
906 **		a, b -- pointers to the internal forms to compare.
907 **		wildflg -- if TRUE, 'a' may have no user specified,
908 **			in which case it is to match anything.
909 **
910 **	Returns:
911 **		TRUE -- they represent the same mailbox.
912 **		FALSE -- they don't.
913 **
914 **	Side Effects:
915 **		none.
916 */
917 
918 bool
919 sameaddr(a, b, wildflg)
920 	register ADDRESS *a;
921 	register ADDRESS *b;
922 	bool wildflg;
923 {
924 	/* if they don't have the same mailer, forget it */
925 	if (a->q_mailer != b->q_mailer)
926 		return (FALSE);
927 
928 	/* if the user isn't the same, we can drop out */
929 	if ((!wildflg || a->q_user[0] != '\0') && strcmp(a->q_user, b->q_user) != 0)
930 		return (FALSE);
931 
932 	/* if the mailer ignores hosts, we have succeeded! */
933 	if (bitset(M_LOCAL, Mailer[a->q_mailer]->m_flags))
934 		return (TRUE);
935 
936 	/* otherwise compare hosts (but be careful for NULL ptrs) */
937 	if (a->q_host == NULL || b->q_host == NULL)
938 		return (FALSE);
939 	if (strcmp(a->q_host, b->q_host) != 0)
940 		return (FALSE);
941 
942 	return (TRUE);
943 }
944 /*
945 **  PRINTADDR -- print address (for debugging)
946 **
947 **	Parameters:
948 **		a -- the address to print
949 **		follow -- follow the q_next chain.
950 **
951 **	Returns:
952 **		none.
953 **
954 **	Side Effects:
955 **		none.
956 */
957 
958 # ifdef DEBUG
959 
960 printaddr(a, follow)
961 	register ADDRESS *a;
962 	bool follow;
963 {
964 	while (a != NULL)
965 	{
966 		printf("addr@%x: ", a);
967 		(void) fflush(stdout);
968 		printf("%s: mailer %d (%s), host `%s', user `%s'\n", a->q_paddr,
969 		       a->q_mailer, Mailer[a->q_mailer]->m_name, a->q_host, a->q_user);
970 		printf("\tnext=%x flags=%o, rmailer %d\n", a->q_next,
971 		       a->q_flags, a->q_rmailer);
972 
973 		if (!follow)
974 			return;
975 		a = a->q_next;
976 	}
977 }
978 
979 # endif DEBUG
980