1/*	$NetBSD: support.c,v 1.27 2023/09/08 20:46:45 shm Exp $	*/
2
3/*
4 * Copyright (c) 1980, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33#ifndef lint
34#if 0
35static char sccsid[] = "@(#)aux.c	8.1 (Berkeley) 6/6/93";
36#else
37__RCSID("$NetBSD: support.c,v 1.27 2023/09/08 20:46:45 shm Exp $");
38#endif
39#endif /* not lint */
40
41#include <stdarg.h>
42#include <util.h>
43
44#include "rcv.h"
45#include "extern.h"
46#include "mime.h"
47#include "thread.h"
48
49/*
50 * Mail -- a mail program
51 *
52 * Auxiliary functions.
53 */
54
55
56/*
57 * Return a pointer to a dynamic copy of the argument.
58 */
59PUBLIC char *
60savestr(const char *str)
61{
62	char *new;
63	size_t size = strlen(str) + 1;
64
65	if ((new = salloc(size)) != NULL)
66		(void)memmove(new, str, size);
67	return new;
68}
69
70/*
71 * Make a copy of new argument incorporating old one.
72 */
73static char *
74save2str(char *str, char *old)
75{
76	char *new;
77	size_t newsize = strlen(str) + 1;
78	size_t oldsize = old ? strlen(old) + 1 : 0;
79
80	if ((new = salloc(newsize + oldsize)) != NULL) {
81		if (oldsize) {
82			(void)memmove(new, old, oldsize);
83			new[oldsize - 1] = ' ';
84		}
85		(void)memmove(new + oldsize, str, newsize);
86	}
87	return new;
88}
89
90/*
91 * Like asprintf(), but with result salloc-ed rather than malloc-ed.
92 */
93PUBLIC int
94sasprintf(char **ret, const char *format, ...)
95{
96	int rval;
97	char *p;
98	va_list args;
99
100	va_start(args, format);
101	rval = evasprintf(&p, format, args);
102	*ret = savestr(p);
103	free(p);
104	va_end(args);
105	return rval;
106}
107
108struct set_m_flag_args_s {
109	int and_bits;
110	int xor_bits;
111};
112static int
113set_m_flag_core(struct message *mp, void *v)
114{
115	struct set_m_flag_args_s *args;
116	args = v;
117	mp->m_flag &= args->and_bits;
118	mp->m_flag ^= args->xor_bits;
119	return 0;
120}
121
122PUBLIC struct message *
123set_m_flag(int msgnum, int and_bits, int xor_bits)
124{
125	struct message *mp;
126	struct set_m_flag_args_s args;
127	mp = get_message(msgnum);
128	args.and_bits = and_bits;
129	args.xor_bits = xor_bits;
130	(void)thread_recursion(mp, set_m_flag_core, &args);
131	return mp;
132}
133
134/*
135 * Touch the named message by setting its MTOUCH flag.
136 * Touched messages have the effect of not being sent
137 * back to the system mailbox on exit.
138 */
139PUBLIC void
140touch(struct message *mp)
141{
142
143	mp->m_flag |= MTOUCH;
144	if ((mp->m_flag & MREAD) == 0)
145		mp->m_flag |= MREAD|MSTATUS;
146}
147
148/*
149 * Test to see if the passed file name is a directory.
150 * Return true if it is.
151 */
152PUBLIC int
153isdir(const char name[])
154{
155	struct stat sbuf;
156
157	if (stat(name, &sbuf) < 0)
158		return 0;
159	return S_ISDIR(sbuf.st_mode);
160}
161
162/*
163 * Count the number of arguments in the given string raw list.
164 */
165PUBLIC int
166argcount(char **argv)
167{
168	char **ap;
169
170	for (ap = argv; *ap++ != NULL; /*EMPTY*/)
171		continue;
172	return (int)(ap - argv - 1);
173}
174
175/*
176 * Check whether the passed line is a header line of
177 * the desired breed.  Return the field body, or NULL.
178 */
179static char*
180ishfield(const char linebuf[], char *colon, const char field[])
181{
182	char *cp = colon;
183
184	*cp = 0;
185	if (strcasecmp(linebuf, field) != 0) {
186		*cp = ':';
187		return NULL;
188	}
189	*cp = ':';
190	for (cp++; is_WSP(*cp); cp++)
191		continue;
192	return cp;
193}
194
195/*
196 * Return the next header field found in the given message.
197 * Return >= 0 if something found, < 0 elsewise.
198 * "colon" is set to point to the colon in the header.
199 * Must deal with \ continuations & other such fraud.
200 *
201 * WARNING - do not call this outside hfield() or decoding will not
202 *           get done.
203 */
204static int
205gethfield(FILE *f, char linebuf[], int rem, char **colon)
206{
207	char line2[LINESIZE];
208	char *cp, *cp2;
209	int c;
210
211	for (;;) {
212		if (--rem < 0)
213			return -1;
214		if ((c = readline(f, linebuf, LINESIZE, 0)) <= 0)
215			return -1;
216		for (cp = linebuf;
217		     isprint((unsigned char)*cp) && *cp != ' ' && *cp != ':';
218		     cp++)
219			continue;
220		if (*cp != ':' || cp == linebuf)
221			continue;
222		/*
223		 * I guess we got a headline.
224		 * Handle wraparounding
225		 */
226		*colon = cp;
227		cp = linebuf + c;
228		for (;;) {
229			while (--cp >= linebuf && is_WSP(*cp))
230				continue;
231			cp++;
232			if (rem <= 0)
233				break;
234			(void)ungetc(c = getc(f), f);
235			if (!is_WSP(c))
236				break;
237			if ((c = readline(f, line2, LINESIZE, 0)) < 0)
238				break;
239			rem--;
240			cp2 = skip_WSP(line2);
241			c -= (int)(cp2 - line2);
242			if (cp + c >= linebuf + LINESIZE - 2)
243				break;
244			*cp++ = ' ';
245			(void)memmove(cp, cp2, (size_t)c);
246			cp += c;
247		}
248		*cp = 0;
249		return rem;
250	}
251	/* NOTREACHED */
252}
253
254/*
255 * Return the desired header line from the passed message
256 * pointer (or NULL if the desired header field is not available).
257 */
258PUBLIC char *
259hfield(const char field[], const struct message *mp)
260{
261	FILE *ibuf;
262	char linebuf[LINESIZE];
263	int lc;
264	char *headerfield;
265	char *colon, *oldhfield = NULL;
266#ifdef MIME_SUPPORT
267	int decode;
268
269	decode = value(ENAME_MIME_DECODE_MSG) &&
270	    value(ENAME_MIME_DECODE_HDR);
271#endif
272
273	ibuf = setinput(mp);
274	if ((lc = (int)(mp->m_lines - 1)) < 0)
275		return NULL;
276	if (readline(ibuf, linebuf, LINESIZE, 0) < 0)
277		return NULL;
278	while (lc > 0) {
279		if ((lc = gethfield(ibuf, linebuf, lc, &colon)) < 0)
280			return oldhfield;
281#ifdef MIME_SUPPORT
282		if ((headerfield = ishfield(linebuf, colon, field)) != NULL) {
283			char linebuf2[LINESIZE];
284			if (decode)
285				headerfield = mime_decode_hfield(linebuf2,
286				    sizeof(linebuf2), linebuf, headerfield);
287			oldhfield = save2str(headerfield, oldhfield);
288		}
289#else
290		if ((headerfield = ishfield(linebuf, colon, field)) != NULL)
291			oldhfield = save2str(headerfield, oldhfield);
292#endif
293	}
294	return oldhfield;
295}
296
297/*
298 * Copy a string, lowercasing it as we go.
299 */
300PUBLIC void
301istrcpy(char *dest, const char *src)
302{
303
304	do {
305		*dest++ = tolower((unsigned char)*src);
306	} while (*src++ != 0);
307}
308
309/*
310 * The following code deals with input stacking to do source
311 * commands.  All but the current file pointer are saved on
312 * the stack.
313 */
314
315static	int	ssp;			/* Top of file stack */
316static struct sstack {
317	FILE	*s_file;		/* File we were in. */
318	int	s_cond;			/* Saved state of conditionals */
319#ifdef NEW_CONDITIONAL
320	struct cond_stack_s *s_cond_stack; /* Saved conditional stack */
321#endif
322	int	s_loading;		/* Loading .mailrc, etc. */
323} sstack[NOFILE];
324
325/*
326 * Pushdown current input file and switch to a new one.
327 * Set the global flag "sourcing" so that others will realize
328 * that they are no longer reading from a tty (in all probability).
329 */
330PUBLIC int
331source(void *v)
332{
333	char **arglist = v;
334	FILE *fi;
335	const char *cp;
336
337	if ((cp = expand(*arglist)) == NULL)
338		return 1;
339	if ((fi = Fopen(cp, "ref")) == NULL) {
340		warn("%s", cp);
341		return 1;
342	}
343	if (ssp >= NOFILE - 1) {
344		(void)printf("Too much \"sourcing\" going on.\n");
345		(void)Fclose(fi);
346		return 1;
347	}
348	sstack[ssp].s_file = input;
349	sstack[ssp].s_cond = cond;
350#ifdef NEW_CONDITIONAL
351	sstack[ssp].s_cond_stack = cond_stack;
352#endif
353	sstack[ssp].s_loading = loading;
354	ssp++;
355	loading = 0;
356	cond = CNONE;
357	input = fi;
358	sourcing++;
359	return 0;
360}
361
362/*
363 * Pop the current input back to the previous level.
364 * Update the "sourcing" flag as appropriate.
365 */
366PUBLIC int
367unstack(void)
368{
369	if (ssp <= 0) {
370		(void)printf("\"Source\" stack over-pop.\n");
371		sourcing = 0;
372		return 1;
373	}
374	(void)Fclose(input);
375	if (cond != CNONE || cond_stack != NULL)
376		(void)printf("Unmatched \"if\"\n");
377	ssp--;
378	input = sstack[ssp].s_file;
379	cond = sstack[ssp].s_cond;
380#ifdef NEW_CONDITIONAL
381	cond_stack = sstack[ssp].s_cond_stack;
382#endif
383	loading = sstack[ssp].s_loading;
384	if (ssp == 0)
385		sourcing = loading;
386	return 0;
387}
388
389/*
390 * Touch the indicated file.
391 * This is nifty for the shell.
392 */
393PUBLIC void
394alter(char *name)
395{
396	struct stat sb;
397	struct timeval tv[2];
398
399	if (stat(name, &sb))
400		return;
401	(void)gettimeofday(&tv[0], NULL);
402	tv[0].tv_sec++;
403	TIMESPEC_TO_TIMEVAL(&tv[1], &sb.st_mtimespec);
404	(void)utimes(name, tv);
405}
406
407/*
408 * Examine the passed line buffer and
409 * return true if it is all blanks and tabs.
410 */
411PUBLIC int
412blankline(char linebuf[])
413{
414	char *cp;
415
416	for (cp = linebuf; *cp; cp++)
417		if (!is_WSP(*cp))
418			return 0;
419	return 1;
420}
421
422/*
423 * Start of a "comment".
424 * Ignore it.
425 */
426static char *
427skip_comment(char *cp)
428{
429	int nesting = 1;
430
431	for (/*EMPTY*/; nesting > 0 && *cp; cp++) {
432		switch (*cp) {
433		case '\\':
434			if (cp[1])
435				cp++;
436			break;
437		case '(':
438			nesting++;
439			break;
440		case ')':
441			nesting--;
442			break;
443		}
444	}
445	return cp;
446}
447
448/*
449 * Skin an arpa net address according to the RFC 822 interpretation
450 * of "host-phrase."
451 */
452PUBLIC char *
453skin(char *name)
454{
455	int c;
456	char *cp, *cp2;
457	char *bufend;
458	int gotlt, lastsp;
459	char *nbuf, *ret;
460
461	if (name == NULL)
462		return NULL;
463	if (strchr(name, '(') == NULL && strchr(name, '<') == NULL
464	    && strchr(name, ' ') == NULL)
465		return name;
466
467	nbuf = emalloc(strlen(name) + 1);
468	gotlt = 0;
469	lastsp = 0;
470	bufend = nbuf;
471	for (cp = name, cp2 = bufend; (c = *cp++) != '\0'; /*EMPTY*/) {
472		switch (c) {
473		case '(':
474			cp = skip_comment(cp);
475			lastsp = 0;
476			break;
477
478		case '"':
479			/*
480			 * Start of a "quoted-string".
481			 * Copy it in its entirety.
482			 */
483			while ((c = *cp) != '\0') {
484				cp++;
485				if (c == '"')
486					break;
487				if (c != '\\')
488					*cp2++ = c;
489				else if ((c = *cp) != '\0') {
490					*cp2++ = c;
491					cp++;
492				}
493			}
494			lastsp = 0;
495			break;
496
497		case ' ':
498			if (cp[0] == 'a' && cp[1] == 't' && cp[2] == ' ')
499				cp += 3, *cp2++ = '@';
500			else
501			if (cp[0] == '@' && cp[1] == ' ')
502				cp += 2, *cp2++ = '@';
503			else
504				lastsp = 1;
505			break;
506
507		case '<':
508			cp2 = bufend;
509			gotlt++;
510			lastsp = 0;
511			break;
512
513		case '>':
514			if (gotlt) {
515				gotlt = 0;
516				while ((c = *cp) && c != ',') {
517					cp++;
518					if (c == '(')
519						cp = skip_comment(cp);
520					else if (c == '"')
521						while ((c = *cp) != '\0') {
522							cp++;
523							if (c == '"')
524								break;
525							if (c == '\\' && *cp)
526								cp++;
527						}
528				}
529				lastsp = 0;
530				break;
531			}
532			/* FALLTHROUGH */
533
534		default:
535			if (lastsp) {
536				lastsp = 0;
537				*cp2++ = ' ';
538			}
539			*cp2++ = c;
540			if (c == ',' && *cp == ' ' && !gotlt) {
541				*cp2++ = ' ';
542				for (/*EMPTY*/; *cp == ' '; cp++)
543					continue;
544				lastsp = 0;
545				bufend = cp2;
546			}
547		}
548	}
549	*cp2 = 0;
550
551	ret = savestr(nbuf);
552	free(nbuf);
553
554	return ret;
555}
556
557/*
558 * Fetch the sender's name from the passed message.
559 * Reptype can be
560 *	0 -- get sender's name for display purposes
561 *	1 -- get sender's name for reply
562 *	2 -- get sender's name for Reply
563 */
564static char *
565name1(struct message *mp, int reptype)
566{
567	char namebuf[LINESIZE];
568	char linebuf[LINESIZE];
569	char *cp, *cp2;
570	FILE *ibuf;
571	int firstrun = 1;
572
573	if ((cp = hfield("from", mp)) != NULL)
574		return cp;
575	if (reptype == 0 && (cp = hfield("sender", mp)) != NULL)
576		return cp;
577	ibuf = setinput(mp);
578	namebuf[0] = '\0';
579	if (readline(ibuf, linebuf, LINESIZE, 0) < 0)
580		return savestr(namebuf);
581 newname:
582	for (cp = linebuf; *cp && *cp != ' '; cp++)
583		continue;
584	cp = skip_WSP(cp);
585	for (cp2 = &namebuf[strlen(namebuf)];
586	     *cp && !is_WSP(*cp) && cp2 < namebuf + LINESIZE - 1;
587	     /*EMPTY*/)
588		*cp2++ = *cp++;
589	*cp2 = '\0';
590	if (readline(ibuf, linebuf, LINESIZE, 0) < 0)
591		return savestr(namebuf);
592	if ((cp = strchr(linebuf, 'F')) == NULL)
593		return savestr(namebuf);
594	if (strncmp(cp, "From", 4) != 0)
595		return savestr(namebuf);
596	while ((cp = strchr(cp, 'r')) != NULL) {
597		if (strncmp(cp, "remote", 6) == 0) {
598			if ((cp = strchr(cp, 'f')) == NULL)
599				break;
600			if (strncmp(cp, "from", 4) != 0)
601				break;
602			if ((cp = strchr(cp, ' ')) == NULL)
603				break;
604			cp++;
605			if (firstrun) {
606				cp2 = namebuf;
607				firstrun = 0;
608			} else
609				cp2 = strrchr(namebuf, '!') + 1;
610			while (*cp && cp2 < namebuf + LINESIZE - 1)
611				*cp2++ = *cp++;
612			if (cp2 < namebuf + LINESIZE - 1)
613				*cp2++ = '!';
614			*cp2 = '\0';
615			if (cp2 < namebuf + LINESIZE - 1)
616				goto newname;
617			else
618				break;
619		}
620		cp++;
621	}
622	return savestr(namebuf);
623}
624
625/*
626 * Count the occurrences of c in str
627 */
628static int
629charcount(char *str, int c)
630{
631	char *cp;
632	int i;
633
634	for (i = 0, cp = str; *cp; cp++)
635		if (*cp == c)
636			i++;
637	return i;
638}
639
640/*
641 * Get sender's name from this message.  If the message has
642 * a bunch of arpanet stuff in it, we may have to skin the name
643 * before returning it.
644 */
645PUBLIC char *
646nameof(struct message *mp, int reptype)
647{
648	char *cp, *cp2;
649
650	cp = skin(name1(mp, reptype));
651	if (reptype != 0 || charcount(cp, '!') < 2)
652		return cp;
653	cp2 = strrchr(cp, '!');
654	cp2--;
655	while (cp2 > cp && *cp2 != '!')
656		cp2--;
657	if (*cp2 == '!')
658		return cp2 + 1;
659	return cp;
660}
661
662/*
663 * Copy s1 to s2, return pointer to null in s2.
664 */
665PUBLIC char *
666copy(char *s1, char *s2)
667{
668
669	while ((*s2++ = *s1++) != '\0')
670		continue;
671	return s2 - 1;
672}
673
674/*
675 * The core routine to check the ignore table for a field.
676 * Note: realfield should be lower-cased!
677 */
678PUBLIC int
679member(char *realfield, struct ignoretab *table)
680{
681	struct ignore *igp;
682
683	for (igp = table->i_head[hash(realfield)]; igp != 0; igp = igp->i_link)
684		if (*igp->i_field == *realfield &&
685		    equal(igp->i_field, realfield))
686			return 1;
687	return 0;
688}
689
690/*
691 * See if the given header field is supposed to be ignored.
692 */
693PUBLIC int
694isign(const char *field, struct ignoretab ignoretabs[2])
695{
696	char realfld[LINESIZE];
697
698	if (ignoretabs == ignoreall)
699		return 1;
700	/*
701	 * Lower-case the string, so that "Status" and "status"
702	 * will hash to the same place.
703	 */
704	istrcpy(realfld, field);
705	if (ignoretabs[1].i_count > 0)
706		return !member(realfld, ignoretabs + 1);
707	else
708		return member(realfld, ignoretabs);
709}
710
711PUBLIC void
712add_ignore(const char *name, struct ignoretab *tab)
713{
714	char field[LINESIZE];
715	int h;
716	struct ignore *igp;
717
718	istrcpy(field, name);
719	if (member(field, tab))
720		return;
721	h = hash(field);
722	igp = ecalloc(1, sizeof(struct ignore));
723	igp->i_field = ecalloc(strlen(field) + 1, sizeof(char));
724	(void)strcpy(igp->i_field, field);
725	igp->i_link = tab->i_head[h];
726	tab->i_head[h] = igp;
727	tab->i_count++;
728}
729
730/*
731 * Write a file to stdout, skipping comment lines.
732 */
733PUBLIC void
734cathelp(const char *fname)
735{
736	char *line;
737	FILE *f;
738	size_t len;
739
740	if ((f = Fopen(fname, "ref")) == NULL) {
741		warn("%s", fname);
742		return;
743	}
744	while ((line = fgetln(f, &len)) != NULL) {
745		if (*line == '#')
746			continue;
747		if (fwrite(line, 1, len, stdout) != len)
748			break;
749	}
750	(void)Fclose(f);
751	return;
752}
753