xref: /freebsd/usr.bin/mail/lex.c (revision 0440b3d2cbf83afb55209a9938b31a48912f222c)
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 <errno.h>
34 #include <fcntl.h>
35 #include "extern.h"
36 
37 /*
38  * Mail -- a mail program
39  *
40  * Lexical processing of commands.
41  */
42 
43 static const char	*prompt = "& ";
44 
45 extern const struct cmd cmdtab[];
46 extern const char *version;
47 
48 /*
49  * Set up editing on the given file name.
50  * If the first character of name is %, we are considered to be
51  * editing the file, otherwise we are reading our mail which has
52  * signficance for mbox and so forth.
53  *
54  * If the -e option is being passed to mail, this function has a
55  * tri-state return code: -1 on error, 0 on no mail, 1 if there is
56  * mail.
57  */
58 int
59 setfile(char *name)
60 {
61 	FILE *ibuf;
62 	int checkmode, i, fd;
63 	struct stat stb;
64 	char isedit = *name != '%' || getuserid(myname) != getuid();
65 	char *who = name[1] ? name + 1 : myname;
66 	char tempname[PATHSIZE];
67 	static int shudclob;
68 
69 	checkmode = value("checkmode") != NULL;
70 	if ((name = expand(name)) == NULL)
71 		return (-1);
72 
73 	if ((ibuf = Fopen(name, "r")) == NULL) {
74 		if (!isedit && errno == ENOENT)
75 			goto nomail;
76 		warn("%s", name);
77 		return (-1);
78 	}
79 
80 	if (fstat(fileno(ibuf), &stb) < 0) {
81 		warn("fstat");
82 		(void)Fclose(ibuf);
83 		return (-1);
84 	}
85 
86 	if (S_ISDIR(stb.st_mode) || !S_ISREG(stb.st_mode)) {
87 		(void)Fclose(ibuf);
88 		errno = S_ISDIR(stb.st_mode) ? EISDIR : EINVAL;
89 		warn("%s", name);
90 		return (-1);
91 	}
92 
93 	/*
94 	 * Looks like all will be well.  We must now relinquish our
95 	 * hold on the current set of stuff.  Must hold signals
96 	 * while we are reading the new file, else we will ruin
97 	 * the message[] data structure.
98 	 */
99 
100 	holdsigs();
101 	if (shudclob)
102 		quit();
103 
104 	/*
105 	 * Copy the messages into /tmp
106 	 * and set pointers.
107 	 */
108 
109 	readonly = 0;
110 	if ((i = open(name, 1)) < 0)
111 		readonly++;
112 	else
113 		(void)close(i);
114 	if (shudclob) {
115 		(void)fclose(itf);
116 		(void)fclose(otf);
117 	}
118 	shudclob = 1;
119 	edit = isedit;
120 	strlcpy(prevfile, mailname, sizeof(prevfile));
121 	if (name != mailname)
122 		strlcpy(mailname, name, sizeof(mailname));
123 	mailsize = fsize(ibuf);
124 	(void)snprintf(tempname, sizeof(tempname),
125 	    "%s/mail.RxXXXXXXXXXX", tmpdir);
126 	if ((fd = mkstemp(tempname)) == -1 || (otf = fdopen(fd, "w")) == NULL)
127 		err(1, "%s", tempname);
128 	(void)fcntl(fileno(otf), F_SETFD, 1);
129 	if ((itf = fopen(tempname, "r")) == NULL)
130 		err(1, "%s", tempname);
131 	(void)fcntl(fileno(itf), F_SETFD, 1);
132 	(void)rm(tempname);
133 	setptr(ibuf, 0);
134 	setmsize(msgCount);
135 	/*
136 	 * New mail may have arrived while we were reading
137 	 * the mail file, so reset mailsize to be where
138 	 * we really are in the file...
139 	 */
140 	mailsize = ftello(ibuf);
141 	(void)Fclose(ibuf);
142 	relsesigs();
143 	sawcom = 0;
144 
145 	if ((checkmode || !edit) && msgCount == 0) {
146 nomail:
147 		if (!checkmode) {
148 			fprintf(stderr, "No mail for %s\n", who);
149 			return (-1);
150 		} else
151 			return (0);
152 	}
153 	return (checkmode ? 1 : 0);
154 }
155 
156 /*
157  * Incorporate any new mail that has arrived since we first
158  * started reading mail.
159  */
160 int
161 incfile(void)
162 {
163 	off_t newsize;
164 	int omsgCount = msgCount;
165 	FILE *ibuf;
166 
167 	ibuf = Fopen(mailname, "r");
168 	if (ibuf == NULL)
169 		return (-1);
170 	holdsigs();
171 	newsize = fsize(ibuf);
172 	if (newsize == 0)
173 		return (-1);		/* mail box is now empty??? */
174 	if (newsize < mailsize)
175 		return (-1);		/* mail box has shrunk??? */
176 	if (newsize == mailsize)
177 		return (0);		/* no new mail */
178 	setptr(ibuf, mailsize);
179 	setmsize(msgCount);
180 	mailsize = ftello(ibuf);
181 	(void)Fclose(ibuf);
182 	relsesigs();
183 	return (msgCount - omsgCount);
184 }
185 
186 static int	*msgvec;
187 static int	reset_on_stop;		/* do a reset() if stopped */
188 
189 /*
190  * Interpret user commands one by one.  If standard input is not a tty,
191  * print no prompt.
192  */
193 void
194 commands(void)
195 {
196 	int n, eofloop = 0;
197 	char linebuf[LINESIZE];
198 
199 	if (!sourcing) {
200 		if (signal(SIGINT, SIG_IGN) != SIG_IGN)
201 			(void)signal(SIGINT, intr);
202 		(void)signal(SIGTSTP, stop);
203 		(void)signal(SIGTTOU, stop);
204 		(void)signal(SIGTTIN, stop);
205 	}
206 	setexit();
207 	for (;;) {
208 		/*
209 		 * Print the prompt, if needed.  Clear out
210 		 * string space, and flush the output.
211 		 */
212 		if (!sourcing && value("interactive") != NULL) {
213 			if ((value("autoinc") != NULL) && (incfile() > 0))
214 				printf("New mail has arrived.\n");
215 			reset_on_stop = 1;
216 			printf("%s", prompt);
217 		}
218 		(void)fflush(stdout);
219 		sreset();
220 		/*
221 		 * Read a line of commands from the current input
222 		 * and handle end of file specially.
223 		 */
224 		n = 0;
225 		for (;;) {
226 			if (readline(input, &linebuf[n], LINESIZE - n) < 0) {
227 				if (n == 0)
228 					n = -1;
229 				break;
230 			}
231 			if ((n = strlen(linebuf)) == 0)
232 				break;
233 			n--;
234 			if (linebuf[n] != '\\')
235 				break;
236 			linebuf[n++] = ' ';
237 		}
238 		reset_on_stop = 0;
239 		if (n < 0) {
240 				/* eof */
241 			if (loading)
242 				break;
243 			if (sourcing) {
244 				unstack();
245 				continue;
246 			}
247 			if (value("interactive") != NULL &&
248 			    value("ignoreeof") != NULL &&
249 			    ++eofloop < 25) {
250 				printf("Use \"quit\" to quit.\n");
251 				continue;
252 			}
253 			break;
254 		}
255 		eofloop = 0;
256 		if (execute(linebuf, 0))
257 			break;
258 	}
259 }
260 
261 /*
262  * Execute a single command.
263  * Command functions return 0 for success, 1 for error, and -1
264  * for abort.  A 1 or -1 aborts a load or source.  A -1 aborts
265  * the interactive command loop.
266  * Contxt is non-zero if called while composing mail.
267  */
268 int
269 execute(char linebuf[], int contxt)
270 {
271 	char word[LINESIZE];
272 	char *arglist[MAXARGC];
273 	const struct cmd *com;
274 	char *cp, *cp2;
275 	int c, muvec[2];
276 	int e = 1;
277 
278 	/*
279 	 * Strip the white space away from the beginning
280 	 * of the command, then scan out a word, which
281 	 * consists of anything except digits and white space.
282 	 *
283 	 * Handle ! escapes differently to get the correct
284 	 * lexical conventions.
285 	 */
286 
287 	for (cp = linebuf; isspace((unsigned char)*cp); cp++)
288 		;
289 	if (*cp == '!') {
290 		if (sourcing) {
291 			printf("Can't \"!\" while sourcing\n");
292 			goto out;
293 		}
294 		shell(cp+1);
295 		return (0);
296 	}
297 	cp2 = word;
298 	while (*cp != '\0' && strchr(" \t0123456789$^.:/-+*'\"", *cp) == NULL)
299 		*cp2++ = *cp++;
300 	*cp2 = '\0';
301 
302 	/*
303 	 * Look up the command; if not found, bitch.
304 	 * Normally, a blank command would map to the
305 	 * first command in the table; while sourcing,
306 	 * however, we ignore blank lines to eliminate
307 	 * confusion.
308 	 */
309 
310 	if (sourcing && *word == '\0')
311 		return (0);
312 	com = lex(word);
313 	if (com == NULL) {
314 		printf("Unknown command: \"%s\"\n", word);
315 		goto out;
316 	}
317 
318 	/*
319 	 * See if we should execute the command -- if a conditional
320 	 * we always execute it, otherwise, check the state of cond.
321 	 */
322 
323 	if ((com->c_argtype & F) == 0)
324 		if ((cond == CRCV && !rcvmode) || (cond == CSEND && rcvmode))
325 			return (0);
326 
327 	/*
328 	 * Process the arguments to the command, depending
329 	 * on the type he expects.  Default to an error.
330 	 * If we are sourcing an interactive command, it's
331 	 * an error.
332 	 */
333 
334 	if (!rcvmode && (com->c_argtype & M) == 0) {
335 		printf("May not execute \"%s\" while sending\n",
336 		    com->c_name);
337 		goto out;
338 	}
339 	if (sourcing && com->c_argtype & I) {
340 		printf("May not execute \"%s\" while sourcing\n",
341 		    com->c_name);
342 		goto out;
343 	}
344 	if (readonly && com->c_argtype & W) {
345 		printf("May not execute \"%s\" -- message file is read only\n",
346 		   com->c_name);
347 		goto out;
348 	}
349 	if (contxt && com->c_argtype & R) {
350 		printf("Cannot recursively invoke \"%s\"\n", com->c_name);
351 		goto out;
352 	}
353 	switch (com->c_argtype & ~(F|P|I|M|T|W|R)) {
354 	case MSGLIST:
355 		/*
356 		 * A message list defaulting to nearest forward
357 		 * legal message.
358 		 */
359 		if (msgvec == 0) {
360 			printf("Illegal use of \"message list\"\n");
361 			break;
362 		}
363 		if ((c = getmsglist(cp, msgvec, com->c_msgflag)) < 0)
364 			break;
365 		if (c  == 0) {
366 			*msgvec = first(com->c_msgflag, com->c_msgmask);
367 			msgvec[1] = 0;
368 		}
369 		if (*msgvec == 0) {
370 			printf("No applicable messages\n");
371 			break;
372 		}
373 		e = (*com->c_func)(msgvec);
374 		break;
375 
376 	case NDMLIST:
377 		/*
378 		 * A message list with no defaults, but no error
379 		 * if none exist.
380 		 */
381 		if (msgvec == 0) {
382 			printf("Illegal use of \"message list\"\n");
383 			break;
384 		}
385 		if (getmsglist(cp, msgvec, com->c_msgflag) < 0)
386 			break;
387 		e = (*com->c_func)(msgvec);
388 		break;
389 
390 	case STRLIST:
391 		/*
392 		 * Just the straight string, with
393 		 * leading blanks removed.
394 		 */
395 		while (isspace((unsigned char)*cp))
396 			cp++;
397 		e = (*com->c_func)(cp);
398 		break;
399 
400 	case RAWLIST:
401 		/*
402 		 * A vector of strings, in shell style.
403 		 */
404 		if ((c = getrawlist(cp, arglist,
405 		    sizeof(arglist) / sizeof(*arglist))) < 0)
406 			break;
407 		if (c < com->c_minargs) {
408 			printf("%s requires at least %d arg(s)\n",
409 			    com->c_name, com->c_minargs);
410 			break;
411 		}
412 		if (c > com->c_maxargs) {
413 			printf("%s takes no more than %d arg(s)\n",
414 			    com->c_name, com->c_maxargs);
415 			break;
416 		}
417 		e = (*com->c_func)(arglist);
418 		break;
419 
420 	case NOLIST:
421 		/*
422 		 * Just the constant zero, for exiting,
423 		 * eg.
424 		 */
425 		e = (*com->c_func)(0);
426 		break;
427 
428 	default:
429 		errx(1, "Unknown argtype");
430 	}
431 
432 out:
433 	/*
434 	 * Exit the current source file on
435 	 * error.
436 	 */
437 	if (e) {
438 		if (e < 0)
439 			return (1);
440 		if (loading)
441 			return (1);
442 		if (sourcing)
443 			unstack();
444 		return (0);
445 	}
446 	if (com == NULL)
447 		return (0);
448 	if (value("autoprint") != NULL && com->c_argtype & P)
449 		if ((dot->m_flag & MDELETED) == 0) {
450 			muvec[0] = dot - &message[0] + 1;
451 			muvec[1] = 0;
452 			type(muvec);
453 		}
454 	if (!sourcing && (com->c_argtype & T) == 0)
455 		sawcom = 1;
456 	return (0);
457 }
458 
459 /*
460  * Set the size of the message vector used to construct argument
461  * lists to message list functions.
462  */
463 void
464 setmsize(int sz)
465 {
466 
467 	if (msgvec != NULL)
468 		(void)free(msgvec);
469 	msgvec = calloc((unsigned)(sz + 1), sizeof(*msgvec));
470 }
471 
472 /*
473  * Find the correct command in the command table corresponding
474  * to the passed command "word"
475  */
476 
477 const struct cmd *
478 lex(char word[])
479 {
480 	const struct cmd *cp;
481 
482 	/*
483 	 * ignore trailing chars after `#'
484 	 *
485 	 * lines with beginning `#' are comments
486 	 * spaces before `#' are ignored in execute()
487 	 */
488 
489 	if (*word == '#')
490 	    *(word+1) = '\0';
491 
492 
493 	for (cp = &cmdtab[0]; cp->c_name != NULL; cp++)
494 		if (isprefix(word, cp->c_name))
495 			return (cp);
496 	return (NULL);
497 }
498 
499 /*
500  * Determine if as1 is a valid prefix of as2.
501  * Return true if yep.
502  */
503 int
504 isprefix(const char *as1, const char *as2)
505 {
506 	const char *s1, *s2;
507 
508 	s1 = as1;
509 	s2 = as2;
510 	while (*s1++ == *s2)
511 		if (*s2++ == '\0')
512 			return (1);
513 	return (*--s1 == '\0');
514 }
515 
516 /*
517  * The following gets called on receipt of an interrupt.  This is
518  * to abort printout of a command, mainly.
519  * Dispatching here when command() is inactive crashes rcv.
520  * Close all open files except 0, 1, 2, and the temporary.
521  * Also, unstack all source files.
522  */
523 
524 static int	inithdr;		/* am printing startup headers */
525 
526 void
527 intr(int s __unused)
528 {
529 
530 	noreset = 0;
531 	if (!inithdr)
532 		sawcom++;
533 	inithdr = 0;
534 	while (sourcing)
535 		unstack();
536 
537 	close_all_files();
538 
539 	if (image >= 0) {
540 		(void)close(image);
541 		image = -1;
542 	}
543 	fprintf(stderr, "Interrupt\n");
544 	reset(0);
545 }
546 
547 /*
548  * When we wake up after ^Z, reprint the prompt.
549  */
550 void
551 stop(int s)
552 {
553 	sig_t old_action = signal(s, SIG_DFL);
554 	sigset_t nset;
555 
556 	(void)sigemptyset(&nset);
557 	(void)sigaddset(&nset, s);
558 	(void)sigprocmask(SIG_UNBLOCK, &nset, NULL);
559 	(void)kill(0, s);
560 	(void)sigprocmask(SIG_BLOCK, &nset, NULL);
561 	(void)signal(s, old_action);
562 	if (reset_on_stop) {
563 		reset_on_stop = 0;
564 		reset(0);
565 	}
566 }
567 
568 /*
569  * Announce the presence of the current Mail version,
570  * give the message count, and print a header listing.
571  */
572 void
573 announce(void)
574 {
575 	int vec[2], mdot;
576 
577 	mdot = newfileinfo(0);
578 	vec[0] = mdot;
579 	vec[1] = 0;
580 	dot = &message[mdot - 1];
581 	if (msgCount > 0 && value("noheader") == NULL) {
582 		inithdr++;
583 		headers(vec);
584 		inithdr = 0;
585 	}
586 }
587 
588 /*
589  * Announce information about the file we are editing.
590  * Return a likely place to set dot.
591  */
592 int
593 newfileinfo(int omsgCount)
594 {
595 	struct message *mp;
596 	int u, n, mdot, d, s;
597 	char fname[PATHSIZE+1], zname[PATHSIZE+1], *ename;
598 
599 	for (mp = &message[omsgCount]; mp < &message[msgCount]; mp++)
600 		if (mp->m_flag & MNEW)
601 			break;
602 	if (mp >= &message[msgCount])
603 		for (mp = &message[omsgCount]; mp < &message[msgCount]; mp++)
604 			if ((mp->m_flag & MREAD) == 0)
605 				break;
606 	if (mp < &message[msgCount])
607 		mdot = mp - &message[0] + 1;
608 	else
609 		mdot = omsgCount + 1;
610 	s = d = 0;
611 	for (mp = &message[0], n = 0, u = 0; mp < &message[msgCount]; mp++) {
612 		if (mp->m_flag & MNEW)
613 			n++;
614 		if ((mp->m_flag & MREAD) == 0)
615 			u++;
616 		if (mp->m_flag & MDELETED)
617 			d++;
618 		if (mp->m_flag & MSAVED)
619 			s++;
620 	}
621 	ename = mailname;
622 	if (getfold(fname, sizeof(fname) - 1) >= 0) {
623 		strcat(fname, "/");
624 		if (strncmp(fname, mailname, strlen(fname)) == 0) {
625 			(void)snprintf(zname, sizeof(zname), "+%s",
626 			    mailname + strlen(fname));
627 			ename = zname;
628 		}
629 	}
630 	printf("\"%s\": ", ename);
631 	if (msgCount == 1)
632 		printf("1 message");
633 	else
634 		printf("%d messages", msgCount);
635 	if (n > 0)
636 		printf(" %d new", n);
637 	if (u-n > 0)
638 		printf(" %d unread", u);
639 	if (d > 0)
640 		printf(" %d deleted", d);
641 	if (s > 0)
642 		printf(" %d saved", s);
643 	if (readonly)
644 		printf(" [Read only]");
645 	printf("\n");
646 	return (mdot);
647 }
648 
649 /*
650  * Print the current version number.
651  */
652 
653 int
654 pversion(void *arg __unused)
655 {
656 
657 	printf("Version %s\n", version);
658 	return (0);
659 }
660 
661 /*
662  * Load a file of user definitions.
663  */
664 void
665 load(char *name)
666 {
667 	FILE *in, *oldin;
668 
669 	if ((in = Fopen(name, "r")) == NULL)
670 		return;
671 	oldin = input;
672 	input = in;
673 	loading = 1;
674 	sourcing = 1;
675 	commands();
676 	loading = 0;
677 	sourcing = 0;
678 	input = oldin;
679 	(void)Fclose(in);
680 }
681