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#ifndef lint
33#if 0
34static char sccsid[] = "@(#)lex.c	8.2 (Berkeley) 4/20/95";
35#endif
36#endif /* not lint */
37#include <sys/cdefs.h>
38__FBSDID("$FreeBSD$");
39
40#include "rcv.h"
41#include <errno.h>
42#include <fcntl.h>
43#include "extern.h"
44
45/*
46 * Mail -- a mail program
47 *
48 * Lexical processing of commands.
49 */
50
51static const char	*prompt = "& ";
52
53extern const struct cmd cmdtab[];
54extern const char *version;
55
56/*
57 * Set up editing on the given file name.
58 * If the first character of name is %, we are considered to be
59 * editing the file, otherwise we are reading our mail which has
60 * signficance for mbox and so forth.
61 *
62 * If the -e option is being passed to mail, this function has a
63 * tri-state return code: -1 on error, 0 on no mail, 1 if there is
64 * mail.
65 */
66int
67setfile(char *name)
68{
69	FILE *ibuf;
70	int checkmode, i, fd;
71	struct stat stb;
72	char isedit = *name != '%' || getuserid(myname) != getuid();
73	char *who = name[1] ? name + 1 : myname;
74	char tempname[PATHSIZE];
75	static int shudclob;
76
77	checkmode = value("checkmode") != NULL;
78	if ((name = expand(name)) == NULL)
79		return (-1);
80
81	if ((ibuf = Fopen(name, "r")) == NULL) {
82		if (!isedit && errno == ENOENT)
83			goto nomail;
84		warn("%s", name);
85		return (-1);
86	}
87
88	if (fstat(fileno(ibuf), &stb) < 0) {
89		warn("fstat");
90		(void)Fclose(ibuf);
91		return (-1);
92	}
93
94	if (S_ISDIR(stb.st_mode) || !S_ISREG(stb.st_mode)) {
95		(void)Fclose(ibuf);
96		errno = S_ISDIR(stb.st_mode) ? EISDIR : EINVAL;
97		warn("%s", name);
98		return (-1);
99	}
100
101	/*
102	 * Looks like all will be well.  We must now relinquish our
103	 * hold on the current set of stuff.  Must hold signals
104	 * while we are reading the new file, else we will ruin
105	 * the message[] data structure.
106	 */
107
108	holdsigs();
109	if (shudclob)
110		quit();
111
112	/*
113	 * Copy the messages into /tmp
114	 * and set pointers.
115	 */
116
117	readonly = 0;
118	if ((i = open(name, 1)) < 0)
119		readonly++;
120	else
121		(void)close(i);
122	if (shudclob) {
123		(void)fclose(itf);
124		(void)fclose(otf);
125	}
126	shudclob = 1;
127	edit = isedit;
128	strlcpy(prevfile, mailname, sizeof(prevfile));
129	if (name != mailname)
130		strlcpy(mailname, name, sizeof(mailname));
131	mailsize = fsize(ibuf);
132	(void)snprintf(tempname, sizeof(tempname),
133	    "%s/mail.RxXXXXXXXXXX", tmpdir);
134	if ((fd = mkstemp(tempname)) == -1 || (otf = fdopen(fd, "w")) == NULL)
135		err(1, "%s", tempname);
136	(void)fcntl(fileno(otf), F_SETFD, 1);
137	if ((itf = fopen(tempname, "r")) == NULL)
138		err(1, "%s", tempname);
139	(void)fcntl(fileno(itf), F_SETFD, 1);
140	(void)rm(tempname);
141	setptr(ibuf, 0);
142	setmsize(msgCount);
143	/*
144	 * New mail may have arrived while we were reading
145	 * the mail file, so reset mailsize to be where
146	 * we really are in the file...
147	 */
148	mailsize = ftello(ibuf);
149	(void)Fclose(ibuf);
150	relsesigs();
151	sawcom = 0;
152
153	if ((checkmode || !edit) && msgCount == 0) {
154nomail:
155		if (!checkmode) {
156			fprintf(stderr, "No mail for %s\n", who);
157			return (-1);
158		} else
159			return (0);
160	}
161	return (checkmode ? 1 : 0);
162}
163
164/*
165 * Incorporate any new mail that has arrived since we first
166 * started reading mail.
167 */
168int
169incfile(void)
170{
171	off_t newsize;
172	int omsgCount = msgCount;
173	FILE *ibuf;
174
175	ibuf = Fopen(mailname, "r");
176	if (ibuf == NULL)
177		return (-1);
178	holdsigs();
179	newsize = fsize(ibuf);
180	if (newsize == 0)
181		return (-1);		/* mail box is now empty??? */
182	if (newsize < mailsize)
183		return (-1);		/* mail box has shrunk??? */
184	if (newsize == mailsize)
185		return (0);		/* no new mail */
186	setptr(ibuf, mailsize);
187	setmsize(msgCount);
188	mailsize = ftello(ibuf);
189	(void)Fclose(ibuf);
190	relsesigs();
191	return (msgCount - omsgCount);
192}
193
194static int	*msgvec;
195static int	reset_on_stop;		/* do a reset() if stopped */
196
197/*
198 * Interpret user commands one by one.  If standard input is not a tty,
199 * print no prompt.
200 */
201void
202commands(void)
203{
204	int n, eofloop = 0;
205	char linebuf[LINESIZE];
206
207	if (!sourcing) {
208		if (signal(SIGINT, SIG_IGN) != SIG_IGN)
209			(void)signal(SIGINT, intr);
210		if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
211			(void)signal(SIGHUP, hangup);
212		(void)signal(SIGTSTP, stop);
213		(void)signal(SIGTTOU, stop);
214		(void)signal(SIGTTIN, stop);
215	}
216	setexit();
217	for (;;) {
218		/*
219		 * Print the prompt, if needed.  Clear out
220		 * string space, and flush the output.
221		 */
222		if (!sourcing && value("interactive") != NULL) {
223			if ((value("autoinc") != NULL) && (incfile() > 0))
224				printf("New mail has arrived.\n");
225			reset_on_stop = 1;
226			printf("%s", prompt);
227		}
228		(void)fflush(stdout);
229		sreset();
230		/*
231		 * Read a line of commands from the current input
232		 * and handle end of file specially.
233		 */
234		n = 0;
235		for (;;) {
236			if (readline(input, &linebuf[n], LINESIZE - n) < 0) {
237				if (n == 0)
238					n = -1;
239				break;
240			}
241			if ((n = strlen(linebuf)) == 0)
242				break;
243			n--;
244			if (linebuf[n] != '\\')
245				break;
246			linebuf[n++] = ' ';
247		}
248		reset_on_stop = 0;
249		if (n < 0) {
250				/* eof */
251			if (loading)
252				break;
253			if (sourcing) {
254				unstack();
255				continue;
256			}
257			if (value("interactive") != NULL &&
258			    value("ignoreeof") != NULL &&
259			    ++eofloop < 25) {
260				printf("Use \"quit\" to quit.\n");
261				continue;
262			}
263			break;
264		}
265		eofloop = 0;
266		if (execute(linebuf, 0))
267			break;
268	}
269}
270
271/*
272 * Execute a single command.
273 * Command functions return 0 for success, 1 for error, and -1
274 * for abort.  A 1 or -1 aborts a load or source.  A -1 aborts
275 * the interactive command loop.
276 * Contxt is non-zero if called while composing mail.
277 */
278int
279execute(char linebuf[], int contxt)
280{
281	char word[LINESIZE];
282	char *arglist[MAXARGC];
283	const struct cmd *com;
284	char *cp, *cp2;
285	int c, muvec[2];
286	int e = 1;
287
288	/*
289	 * Strip the white space away from the beginning
290	 * of the command, then scan out a word, which
291	 * consists of anything except digits and white space.
292	 *
293	 * Handle ! escapes differently to get the correct
294	 * lexical conventions.
295	 */
296
297	for (cp = linebuf; isspace((unsigned char)*cp); cp++)
298		;
299	if (*cp == '!') {
300		if (sourcing) {
301			printf("Can't \"!\" while sourcing\n");
302			goto out;
303		}
304		shell(cp+1);
305		return (0);
306	}
307	cp2 = word;
308	while (*cp != '\0' && strchr(" \t0123456789$^.:/-+*'\"", *cp) == NULL)
309		*cp2++ = *cp++;
310	*cp2 = '\0';
311
312	/*
313	 * Look up the command; if not found, bitch.
314	 * Normally, a blank command would map to the
315	 * first command in the table; while sourcing,
316	 * however, we ignore blank lines to eliminate
317	 * confusion.
318	 */
319
320	if (sourcing && *word == '\0')
321		return (0);
322	com = lex(word);
323	if (com == NULL) {
324		printf("Unknown command: \"%s\"\n", word);
325		goto out;
326	}
327
328	/*
329	 * See if we should execute the command -- if a conditional
330	 * we always execute it, otherwise, check the state of cond.
331	 */
332
333	if ((com->c_argtype & F) == 0)
334		if ((cond == CRCV && !rcvmode) || (cond == CSEND && rcvmode))
335			return (0);
336
337	/*
338	 * Process the arguments to the command, depending
339	 * on the type he expects.  Default to an error.
340	 * If we are sourcing an interactive command, it's
341	 * an error.
342	 */
343
344	if (!rcvmode && (com->c_argtype & M) == 0) {
345		printf("May not execute \"%s\" while sending\n",
346		    com->c_name);
347		goto out;
348	}
349	if (sourcing && com->c_argtype & I) {
350		printf("May not execute \"%s\" while sourcing\n",
351		    com->c_name);
352		goto out;
353	}
354	if (readonly && com->c_argtype & W) {
355		printf("May not execute \"%s\" -- message file is read only\n",
356		   com->c_name);
357		goto out;
358	}
359	if (contxt && com->c_argtype & R) {
360		printf("Cannot recursively invoke \"%s\"\n", com->c_name);
361		goto out;
362	}
363	switch (com->c_argtype & ~(F|P|I|M|T|W|R)) {
364	case MSGLIST:
365		/*
366		 * A message list defaulting to nearest forward
367		 * legal message.
368		 */
369		if (msgvec == 0) {
370			printf("Illegal use of \"message list\"\n");
371			break;
372		}
373		if ((c = getmsglist(cp, msgvec, com->c_msgflag)) < 0)
374			break;
375		if (c  == 0) {
376			*msgvec = first(com->c_msgflag, com->c_msgmask);
377			msgvec[1] = 0;
378		}
379		if (*msgvec == 0) {
380			printf("No applicable messages\n");
381			break;
382		}
383		e = (*com->c_func)(msgvec);
384		break;
385
386	case NDMLIST:
387		/*
388		 * A message list with no defaults, but no error
389		 * if none exist.
390		 */
391		if (msgvec == 0) {
392			printf("Illegal use of \"message list\"\n");
393			break;
394		}
395		if (getmsglist(cp, msgvec, com->c_msgflag) < 0)
396			break;
397		e = (*com->c_func)(msgvec);
398		break;
399
400	case STRLIST:
401		/*
402		 * Just the straight string, with
403		 * leading blanks removed.
404		 */
405		while (isspace((unsigned char)*cp))
406			cp++;
407		e = (*com->c_func)(cp);
408		break;
409
410	case RAWLIST:
411		/*
412		 * A vector of strings, in shell style.
413		 */
414		if ((c = getrawlist(cp, arglist,
415		    sizeof(arglist) / sizeof(*arglist))) < 0)
416			break;
417		if (c < com->c_minargs) {
418			printf("%s requires at least %d arg(s)\n",
419			    com->c_name, com->c_minargs);
420			break;
421		}
422		if (c > com->c_maxargs) {
423			printf("%s takes no more than %d arg(s)\n",
424			    com->c_name, com->c_maxargs);
425			break;
426		}
427		e = (*com->c_func)(arglist);
428		break;
429
430	case NOLIST:
431		/*
432		 * Just the constant zero, for exiting,
433		 * eg.
434		 */
435		e = (*com->c_func)(0);
436		break;
437
438	default:
439		errx(1, "Unknown argtype");
440	}
441
442out:
443	/*
444	 * Exit the current source file on
445	 * error.
446	 */
447	if (e) {
448		if (e < 0)
449			return (1);
450		if (loading)
451			return (1);
452		if (sourcing)
453			unstack();
454		return (0);
455	}
456	if (com == NULL)
457		return (0);
458	if (value("autoprint") != NULL && com->c_argtype & P)
459		if ((dot->m_flag & MDELETED) == 0) {
460			muvec[0] = dot - &message[0] + 1;
461			muvec[1] = 0;
462			type(muvec);
463		}
464	if (!sourcing && (com->c_argtype & T) == 0)
465		sawcom = 1;
466	return (0);
467}
468
469/*
470 * Set the size of the message vector used to construct argument
471 * lists to message list functions.
472 */
473void
474setmsize(int sz)
475{
476
477	if (msgvec != NULL)
478		(void)free(msgvec);
479	msgvec = calloc((unsigned)(sz + 1), sizeof(*msgvec));
480}
481
482/*
483 * Find the correct command in the command table corresponding
484 * to the passed command "word"
485 */
486
487const struct cmd *
488lex(char word[])
489{
490	const struct cmd *cp;
491
492	/*
493	 * ignore trailing chars after `#'
494	 *
495	 * lines with beginning `#' are comments
496	 * spaces before `#' are ignored in execute()
497	 */
498
499	if (*word == '#')
500	    *(word+1) = '\0';
501
502
503	for (cp = &cmdtab[0]; cp->c_name != NULL; cp++)
504		if (isprefix(word, cp->c_name))
505			return (cp);
506	return (NULL);
507}
508
509/*
510 * Determine if as1 is a valid prefix of as2.
511 * Return true if yep.
512 */
513int
514isprefix(const char *as1, const char *as2)
515{
516	const char *s1, *s2;
517
518	s1 = as1;
519	s2 = as2;
520	while (*s1++ == *s2)
521		if (*s2++ == '\0')
522			return (1);
523	return (*--s1 == '\0');
524}
525
526/*
527 * The following gets called on receipt of an interrupt.  This is
528 * to abort printout of a command, mainly.
529 * Dispatching here when command() is inactive crashes rcv.
530 * Close all open files except 0, 1, 2, and the temporary.
531 * Also, unstack all source files.
532 */
533
534static int	inithdr;		/* am printing startup headers */
535
536void
537intr(int s __unused)
538{
539
540	noreset = 0;
541	if (!inithdr)
542		sawcom++;
543	inithdr = 0;
544	while (sourcing)
545		unstack();
546
547	close_all_files();
548
549	if (image >= 0) {
550		(void)close(image);
551		image = -1;
552	}
553	fprintf(stderr, "Interrupt\n");
554	reset(0);
555}
556
557/*
558 * When we wake up after ^Z, reprint the prompt.
559 */
560void
561stop(int s)
562{
563	sig_t old_action = signal(s, SIG_DFL);
564	sigset_t nset;
565
566	(void)sigemptyset(&nset);
567	(void)sigaddset(&nset, s);
568	(void)sigprocmask(SIG_UNBLOCK, &nset, NULL);
569	(void)kill(0, s);
570	(void)sigprocmask(SIG_BLOCK, &nset, NULL);
571	(void)signal(s, old_action);
572	if (reset_on_stop) {
573		reset_on_stop = 0;
574		reset(0);
575	}
576}
577
578/*
579 * Branch here on hangup signal and simulate "exit".
580 */
581void
582hangup(int s __unused)
583{
584
585	/* nothing to do? */
586	exit(1);
587}
588
589/*
590 * Announce the presence of the current Mail version,
591 * give the message count, and print a header listing.
592 */
593void
594announce(void)
595{
596	int vec[2], mdot;
597
598	mdot = newfileinfo(0);
599	vec[0] = mdot;
600	vec[1] = 0;
601	dot = &message[mdot - 1];
602	if (msgCount > 0 && value("noheader") == NULL) {
603		inithdr++;
604		headers(vec);
605		inithdr = 0;
606	}
607}
608
609/*
610 * Announce information about the file we are editing.
611 * Return a likely place to set dot.
612 */
613int
614newfileinfo(int omsgCount)
615{
616	struct message *mp;
617	int u, n, mdot, d, s;
618	char fname[PATHSIZE+1], zname[PATHSIZE+1], *ename;
619
620	for (mp = &message[omsgCount]; mp < &message[msgCount]; mp++)
621		if (mp->m_flag & MNEW)
622			break;
623	if (mp >= &message[msgCount])
624		for (mp = &message[omsgCount]; mp < &message[msgCount]; mp++)
625			if ((mp->m_flag & MREAD) == 0)
626				break;
627	if (mp < &message[msgCount])
628		mdot = mp - &message[0] + 1;
629	else
630		mdot = omsgCount + 1;
631	s = d = 0;
632	for (mp = &message[0], n = 0, u = 0; mp < &message[msgCount]; mp++) {
633		if (mp->m_flag & MNEW)
634			n++;
635		if ((mp->m_flag & MREAD) == 0)
636			u++;
637		if (mp->m_flag & MDELETED)
638			d++;
639		if (mp->m_flag & MSAVED)
640			s++;
641	}
642	ename = mailname;
643	if (getfold(fname, sizeof(fname) - 1) >= 0) {
644		strcat(fname, "/");
645		if (strncmp(fname, mailname, strlen(fname)) == 0) {
646			(void)snprintf(zname, sizeof(zname), "+%s",
647			    mailname + strlen(fname));
648			ename = zname;
649		}
650	}
651	printf("\"%s\": ", ename);
652	if (msgCount == 1)
653		printf("1 message");
654	else
655		printf("%d messages", msgCount);
656	if (n > 0)
657		printf(" %d new", n);
658	if (u-n > 0)
659		printf(" %d unread", u);
660	if (d > 0)
661		printf(" %d deleted", d);
662	if (s > 0)
663		printf(" %d saved", s);
664	if (readonly)
665		printf(" [Read only]");
666	printf("\n");
667	return (mdot);
668}
669
670/*
671 * Print the current version number.
672 */
673
674int
675pversion(int e __unused)
676{
677
678	printf("Version %s\n", version);
679	return (0);
680}
681
682/*
683 * Load a file of user definitions.
684 */
685void
686load(char *name)
687{
688	FILE *in, *oldin;
689
690	if ((in = Fopen(name, "r")) == NULL)
691		return;
692	oldin = input;
693	input = in;
694	loading = 1;
695	sourcing = 1;
696	commands();
697	loading = 0;
698	sourcing = 0;
699	input = oldin;
700	(void)Fclose(in);
701}
702