1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
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 "rcv.h"
33#include "extern.h"
34
35/*
36 * Mail -- a mail program
37 *
38 * Still more user commands.
39 */
40
41/*
42 * Process a shell escape by saving signals, ignoring signals,
43 * and forking a sh -c
44 */
45int
46shell(void *str)
47{
48	sig_t sigint = signal(SIGINT, SIG_IGN);
49	char *sh;
50	char cmd[BUFSIZ];
51
52	if (strlcpy(cmd, str, sizeof(cmd)) >= sizeof(cmd))
53		return (1);
54	if (bangexp(cmd, sizeof(cmd)) < 0)
55		return (1);
56	if ((sh = value("SHELL")) == NULL)
57		sh = _PATH_CSHELL;
58	(void)run_command(sh, 0, -1, -1, "-c", cmd, NULL);
59	(void)signal(SIGINT, sigint);
60	printf("!\n");
61	return (0);
62}
63
64/*
65 * Fork an interactive shell.
66 */
67/*ARGSUSED*/
68int
69dosh(void *str __unused)
70{
71	sig_t sigint = signal(SIGINT, SIG_IGN);
72	char *sh;
73
74	if ((sh = value("SHELL")) == NULL)
75		sh = _PATH_CSHELL;
76	(void)run_command(sh, 0, -1, -1, NULL);
77	(void)signal(SIGINT, sigint);
78	printf("\n");
79	return (0);
80}
81
82/*
83 * Expand the shell escape by expanding unescaped !'s into the
84 * last issued command where possible.
85 */
86int
87bangexp(char *str, size_t strsize)
88{
89	char bangbuf[BUFSIZ];
90	static char lastbang[BUFSIZ];
91	char *cp, *cp2;
92	int n, changed = 0;
93
94	cp = str;
95	cp2 = bangbuf;
96	n = sizeof(bangbuf);
97	while (*cp != '\0') {
98		if (*cp == '!') {
99			if (n < (int)strlen(lastbang)) {
100overf:
101				printf("Command buffer overflow\n");
102				return (-1);
103			}
104			changed++;
105			if (strlcpy(cp2, lastbang, sizeof(bangbuf) - (cp2 - bangbuf))
106			    >= sizeof(bangbuf) - (cp2 - bangbuf))
107				goto overf;
108			cp2 += strlen(lastbang);
109			n -= strlen(lastbang);
110			cp++;
111			continue;
112		}
113		if (*cp == '\\' && cp[1] == '!') {
114			if (--n <= 1)
115				goto overf;
116			*cp2++ = '!';
117			cp += 2;
118			changed++;
119		}
120		if (--n <= 1)
121			goto overf;
122		*cp2++ = *cp++;
123	}
124	*cp2 = 0;
125	if (changed) {
126		printf("!%s\n", bangbuf);
127		(void)fflush(stdout);
128	}
129	if (strlcpy(str, bangbuf, strsize) >= strsize)
130		goto overf;
131	if (strlcpy(lastbang, bangbuf, sizeof(lastbang)) >= sizeof(lastbang))
132		goto overf;
133	return (0);
134}
135
136/*
137 * Print out a nice help message from some file or another.
138 */
139
140int
141help(void *arg __unused)
142{
143	int c;
144	FILE *f;
145
146	if ((f = Fopen(_PATH_HELP, "r")) == NULL) {
147		warn("%s", _PATH_HELP);
148		return (1);
149	}
150	while ((c = getc(f)) != EOF)
151		putchar(c);
152	(void)Fclose(f);
153	return (0);
154}
155
156/*
157 * Change user's working directory.
158 */
159int
160schdir(void *v)
161{
162	char **arglist = v;
163	char *cp;
164
165	if (*arglist == NULL) {
166		if (homedir == NULL)
167			return (1);
168		cp = homedir;
169	} else
170		if ((cp = expand(*arglist)) == NULL)
171			return (1);
172	if (chdir(cp) < 0) {
173		warn("%s", cp);
174		return (1);
175	}
176	return (0);
177}
178
179int
180respond(void *v)
181{
182	int *msgvec = v;
183
184	if (value("Replyall") == NULL && value("flipr") == NULL)
185		return (dorespond(msgvec));
186	else
187		return (doRespond(msgvec));
188}
189
190/*
191 * Reply to a list of messages.  Extract each name from the
192 * message header and send them off to mail1()
193 */
194int
195dorespond(int *msgvec)
196{
197	struct message *mp;
198	char *cp, *rcv, *replyto;
199	char **ap;
200	struct name *np;
201	struct header head;
202
203	if (msgvec[1] != 0) {
204		printf("Sorry, can't reply to multiple messages at once\n");
205		return (1);
206	}
207	mp = &message[msgvec[0] - 1];
208	touch(mp);
209	dot = mp;
210	if ((rcv = skin(hfield("from", mp))) == NULL)
211		rcv = skin(nameof(mp, 1));
212	if ((replyto = skin(hfield("reply-to", mp))) != NULL)
213		np = extract(replyto, GTO);
214	else if ((cp = skin(hfield("to", mp))) != NULL)
215		np = extract(cp, GTO);
216	else
217		np = NULL;
218	np = elide(np);
219	/*
220	 * Delete my name from the reply list,
221	 * and with it, all my alternate names.
222	 */
223	np = delname(np, myname);
224	if (altnames)
225		for (ap = altnames; *ap != NULL; ap++)
226			np = delname(np, *ap);
227	if (np != NULL && replyto == NULL)
228		np = cat(np, extract(rcv, GTO));
229	else if (np == NULL) {
230		if (replyto != NULL)
231			printf("Empty reply-to field -- replying to author\n");
232		np = extract(rcv, GTO);
233	}
234	head.h_to = np;
235	if ((head.h_subject = hfield("subject", mp)) == NULL)
236		head.h_subject = hfield("subj", mp);
237	head.h_subject = reedit(head.h_subject);
238	if (replyto == NULL && (cp = skin(hfield("cc", mp))) != NULL) {
239		np = elide(extract(cp, GCC));
240		np = delname(np, myname);
241		if (altnames != 0)
242			for (ap = altnames; *ap != NULL; ap++)
243				np = delname(np, *ap);
244		head.h_cc = np;
245	} else
246		head.h_cc = NULL;
247	head.h_bcc = NULL;
248	head.h_smopts = NULL;
249	head.h_replyto = value("REPLYTO");
250	head.h_inreplyto = skin(hfield("message-id", mp));
251	mail1(&head, 1);
252	return (0);
253}
254
255/*
256 * Modify the message subject to begin with "Re:" if
257 * it does not already.
258 */
259char *
260reedit(char *subj)
261{
262	char *newsubj;
263
264	if (subj == NULL)
265		return (NULL);
266	if ((subj[0] == 'r' || subj[0] == 'R') &&
267	    (subj[1] == 'e' || subj[1] == 'E') &&
268	    subj[2] == ':')
269		return (subj);
270	newsubj = salloc(strlen(subj) + 5);
271	sprintf(newsubj, "Re: %s", subj);
272	return (newsubj);
273}
274
275/*
276 * Preserve the named messages, so that they will be sent
277 * back to the system mailbox.
278 */
279int
280preserve(void *v)
281{
282	int *msgvec = v;
283	int *ip, mesg;
284	struct message *mp;
285
286	if (edit) {
287		printf("Cannot \"preserve\" in edit mode\n");
288		return (1);
289	}
290	for (ip = msgvec; *ip != 0; ip++) {
291		mesg = *ip;
292		mp = &message[mesg-1];
293		mp->m_flag |= MPRESERVE;
294		mp->m_flag &= ~MBOX;
295		dot = mp;
296	}
297	return (0);
298}
299
300/*
301 * Mark all given messages as unread.
302 */
303int
304unread(void *v)
305{
306	int *msgvec = v;
307	int *ip;
308
309	for (ip = msgvec; *ip != 0; ip++) {
310		dot = &message[*ip-1];
311		dot->m_flag &= ~(MREAD|MTOUCH);
312		dot->m_flag |= MSTATUS;
313	}
314	return (0);
315}
316
317/*
318 * Print the size of each message.
319 */
320int
321messize(void *v)
322{
323	int *msgvec = v;
324	struct message *mp;
325	int *ip, mesg;
326
327	for (ip = msgvec; *ip != 0; ip++) {
328		mesg = *ip;
329		mp = &message[mesg-1];
330		printf("%d: %ld/%ld\n", mesg, mp->m_lines, mp->m_size);
331	}
332	return (0);
333}
334
335/*
336 * Quit quickly.  If we are sourcing, just pop the input level
337 * by returning an error.
338 */
339int
340rexit(void *v)
341{
342	if (sourcing)
343		return (1);
344	exit(0);
345	/*NOTREACHED*/
346}
347
348/*
349 * Set or display a variable value.  Syntax is similar to that
350 * of csh.
351 */
352int
353set(void *v)
354{
355	char **arglist = v;
356	struct var *vp;
357	char *cp, *cp2;
358	char varbuf[BUFSIZ], **ap, **p;
359	int errs, h, s;
360
361	if (*arglist == NULL) {
362		for (h = 0, s = 1; h < HSHSIZE; h++)
363			for (vp = variables[h]; vp != NULL; vp = vp->v_link)
364				s++;
365		ap = (char **)salloc(s * sizeof(*ap));
366		for (h = 0, p = ap; h < HSHSIZE; h++)
367			for (vp = variables[h]; vp != NULL; vp = vp->v_link)
368				*p++ = vp->v_name;
369		*p = NULL;
370		sort(ap);
371		for (p = ap; *p != NULL; p++)
372			printf("%s\t%s\n", *p, value(*p));
373		return (0);
374	}
375	errs = 0;
376	for (ap = arglist; *ap != NULL; ap++) {
377		cp = *ap;
378		cp2 = varbuf;
379		while (cp2 < varbuf + sizeof(varbuf) - 1 && *cp != '=' && *cp != '\0')
380			*cp2++ = *cp++;
381		*cp2 = '\0';
382		if (*cp == '\0')
383			cp = "";
384		else
385			cp++;
386		if (equal(varbuf, "")) {
387			printf("Non-null variable name required\n");
388			errs++;
389			continue;
390		}
391		assign(varbuf, cp);
392	}
393	return (errs);
394}
395
396/*
397 * Unset a bunch of variable values.
398 */
399int
400unset(void *v)
401{
402	char **arglist = v;
403	struct var *vp, *vp2;
404	int errs, h;
405	char **ap;
406
407	errs = 0;
408	for (ap = arglist; *ap != NULL; ap++) {
409		if ((vp2 = lookup(*ap)) == NULL) {
410			if (getenv(*ap))
411				unsetenv(*ap);
412			else if (!sourcing) {
413				printf("\"%s\": undefined variable\n", *ap);
414				errs++;
415			}
416			continue;
417		}
418		h = hash(*ap);
419		if (vp2 == variables[h]) {
420			variables[h] = variables[h]->v_link;
421			vfree(vp2->v_name);
422			vfree(vp2->v_value);
423			(void)free(vp2);
424			continue;
425		}
426		for (vp = variables[h]; vp->v_link != vp2; vp = vp->v_link)
427			;
428		vp->v_link = vp2->v_link;
429		vfree(vp2->v_name);
430		vfree(vp2->v_value);
431		(void)free(vp2);
432	}
433	return (errs);
434}
435
436/*
437 * Put add users to a group.
438 */
439int
440group(void *v)
441{
442	char **argv = v;
443	struct grouphead *gh;
444	struct group *gp;
445	char **ap, *gname, **p;
446	int h, s;
447
448	if (*argv == NULL) {
449		for (h = 0, s = 1; h < HSHSIZE; h++)
450			for (gh = groups[h]; gh != NULL; gh = gh->g_link)
451				s++;
452		ap = (char **)salloc(s * sizeof(*ap));
453		for (h = 0, p = ap; h < HSHSIZE; h++)
454			for (gh = groups[h]; gh != NULL; gh = gh->g_link)
455				*p++ = gh->g_name;
456		*p = NULL;
457		sort(ap);
458		for (p = ap; *p != NULL; p++)
459			printgroup(*p);
460		return (0);
461	}
462	if (argv[1] == NULL) {
463		printgroup(*argv);
464		return (0);
465	}
466	gname = *argv;
467	h = hash(gname);
468	if ((gh = findgroup(gname)) == NULL) {
469		if ((gh = calloc(1, sizeof(*gh))) == NULL)
470			err(1, "Out of memory");
471		gh->g_name = vcopy(gname);
472		gh->g_list = NULL;
473		gh->g_link = groups[h];
474		groups[h] = gh;
475	}
476
477	/*
478	 * Insert names from the command list into the group.
479	 * Who cares if there are duplicates?  They get tossed
480	 * later anyway.
481	 */
482
483	for (ap = argv+1; *ap != NULL; ap++) {
484		if ((gp = calloc(1, sizeof(*gp))) == NULL)
485			err(1, "Out of memory");
486		gp->ge_name = vcopy(*ap);
487		gp->ge_link = gh->g_list;
488		gh->g_list = gp;
489	}
490	return (0);
491}
492
493/*
494 * Sort the passed string vecotor into ascending dictionary
495 * order.
496 */
497void
498sort(char **list)
499{
500	char **ap;
501
502	for (ap = list; *ap != NULL; ap++)
503		;
504	if (ap-list < 2)
505		return;
506	qsort(list, ap-list, sizeof(*list), diction);
507}
508
509/*
510 * Do a dictionary order comparison of the arguments from
511 * qsort.
512 */
513int
514diction(const void *a, const void *b)
515{
516	return (strcmp(*(const char **)a, *(const char **)b));
517}
518
519/*
520 * The do nothing command for comments.
521 */
522
523/*ARGSUSED*/
524int
525null(void *arg __unused)
526{
527	return (0);
528}
529
530/*
531 * Change to another file.  With no argument, print information about
532 * the current file.
533 */
534int
535file(void *arg)
536{
537	char **argv = arg;
538
539	if (argv[0] == NULL) {
540		newfileinfo(0);
541		return (0);
542	}
543	if (setfile(*argv) < 0)
544		return (1);
545	announce();
546	return (0);
547}
548
549/*
550 * Expand file names like echo
551 */
552int
553echo(void *arg)
554{
555	char **argv = arg;
556	char **ap, *cp;
557
558	for (ap = argv; *ap != NULL; ap++) {
559		cp = *ap;
560		if ((cp = expand(cp)) != NULL) {
561			if (ap != argv)
562				printf(" ");
563			printf("%s", cp);
564		}
565	}
566	printf("\n");
567	return (0);
568}
569
570int
571Respond(void *msgvec)
572{
573	if (value("Replyall") == NULL && value("flipr") == NULL)
574		return (doRespond(msgvec));
575	else
576		return (dorespond(msgvec));
577}
578
579/*
580 * Reply to a series of messages by simply mailing to the senders
581 * and not messing around with the To: and Cc: lists as in normal
582 * reply.
583 */
584int
585doRespond(int msgvec[])
586{
587	struct header head;
588	struct message *mp;
589	int *ap;
590	char *cp, *mid;
591
592	head.h_to = NULL;
593	for (ap = msgvec; *ap != 0; ap++) {
594		mp = &message[*ap - 1];
595		touch(mp);
596		dot = mp;
597		if ((cp = skin(hfield("from", mp))) == NULL)
598			cp = skin(nameof(mp, 2));
599		head.h_to = cat(head.h_to, extract(cp, GTO));
600		mid = skin(hfield("message-id", mp));
601	}
602	if (head.h_to == NULL)
603		return (0);
604	mp = &message[msgvec[0] - 1];
605	if ((head.h_subject = hfield("subject", mp)) == NULL)
606		head.h_subject = hfield("subj", mp);
607	head.h_subject = reedit(head.h_subject);
608	head.h_cc = NULL;
609	head.h_bcc = NULL;
610	head.h_smopts = NULL;
611	head.h_replyto = value("REPLYTO");
612	head.h_inreplyto = mid;
613	mail1(&head, 1);
614	return (0);
615}
616
617/*
618 * Conditional commands.  These allow one to parameterize one's
619 * .mailrc and do some things if sending, others if receiving.
620 */
621int
622ifcmd(void *arg)
623{
624	char **argv = arg;
625	char *cp;
626
627	if (cond != CANY) {
628		printf("Illegal nested \"if\"\n");
629		return (1);
630	}
631	cond = CANY;
632	cp = argv[0];
633	switch (*cp) {
634	case 'r': case 'R':
635		cond = CRCV;
636		break;
637
638	case 's': case 'S':
639		cond = CSEND;
640		break;
641
642	default:
643		printf("Unrecognized if-keyword: \"%s\"\n", cp);
644		return (1);
645	}
646	return (0);
647}
648
649/*
650 * Implement 'else'.  This is pretty simple -- we just
651 * flip over the conditional flag.
652 */
653int
654elsecmd(void *arg __unused)
655{
656
657	switch (cond) {
658	case CANY:
659		printf("\"Else\" without matching \"if\"\n");
660		return (1);
661
662	case CSEND:
663		cond = CRCV;
664		break;
665
666	case CRCV:
667		cond = CSEND;
668		break;
669
670	default:
671		printf("Mail's idea of conditions is screwed up\n");
672		cond = CANY;
673		break;
674	}
675	return (0);
676}
677
678/*
679 * End of if statement.  Just set cond back to anything.
680 */
681int
682endifcmd(void *arg __unused)
683{
684
685	if (cond == CANY) {
686		printf("\"Endif\" without matching \"if\"\n");
687		return (1);
688	}
689	cond = CANY;
690	return (0);
691}
692
693/*
694 * Set the list of alternate names.
695 */
696int
697alternates(void *arg)
698{
699	char **namelist = arg;
700	int c;
701	char **ap, **ap2, *cp;
702
703	c = argcount(namelist) + 1;
704	if (c == 1) {
705		if (altnames == 0)
706			return (0);
707		for (ap = altnames; *ap != NULL; ap++)
708			printf("%s ", *ap);
709		printf("\n");
710		return (0);
711	}
712	if (altnames != 0)
713		(void)free(altnames);
714	if ((altnames = calloc((unsigned)c, sizeof(char *))) == NULL)
715		err(1, "Out of memory");
716	for (ap = namelist, ap2 = altnames; *ap != NULL; ap++, ap2++) {
717		cp = calloc((unsigned)strlen(*ap) + 1, sizeof(char));
718		strcpy(cp, *ap);
719		*ap2 = cp;
720	}
721	*ap2 = 0;
722	return (0);
723}
724