xref: /freebsd/usr.bin/mail/lex.c (revision 2e47009079fc01ca05c9779d85616e1df037693c)
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
setfile(char * name)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
incfile(void)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
commands(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],
227 			    sizeof(linebuf) - n) < 0) {
228 				if (n == 0)
229 					n = -1;
230 				break;
231 			}
232 			if ((n = strlen(linebuf)) == 0)
233 				break;
234 			n--;
235 			if (linebuf[n] != '\\')
236 				break;
237 			linebuf[n++] = ' ';
238 		}
239 		reset_on_stop = 0;
240 		if (n < 0) {
241 				/* eof */
242 			if (loading)
243 				break;
244 			if (sourcing) {
245 				unstack();
246 				continue;
247 			}
248 			if (value("interactive") != NULL &&
249 			    value("ignoreeof") != NULL &&
250 			    ++eofloop < 25) {
251 				printf("Use \"quit\" to quit.\n");
252 				continue;
253 			}
254 			break;
255 		}
256 		eofloop = 0;
257 		if (execute(linebuf, 0))
258 			break;
259 	}
260 }
261 
262 /*
263  * Execute a single command.
264  * Command functions return 0 for success, 1 for error, and -1
265  * for abort.  A 1 or -1 aborts a load or source.  A -1 aborts
266  * the interactive command loop.
267  * Contxt is non-zero if called while composing mail.
268  */
269 int
execute(char linebuf[],int contxt)270 execute(char linebuf[], int contxt)
271 {
272 	char word[LINESIZE];
273 	char *arglist[MAXARGC];
274 	const struct cmd *com;
275 	char *cp, *cp2;
276 	int c, muvec[2];
277 	int e = 1;
278 
279 	/*
280 	 * Strip the white space away from the beginning
281 	 * of the command, then scan out a word, which
282 	 * consists of anything except digits and white space.
283 	 *
284 	 * Handle ! escapes differently to get the correct
285 	 * lexical conventions.
286 	 */
287 
288 	for (cp = linebuf; isspace((unsigned char)*cp); cp++)
289 		;
290 	if (*cp == '!') {
291 		if (sourcing) {
292 			printf("Can't \"!\" while sourcing\n");
293 			goto out;
294 		}
295 		shell(cp+1);
296 		return (0);
297 	}
298 	cp2 = word;
299 	while (*cp != '\0' && strchr(" \t0123456789$^.:/-+*'\"", *cp) == NULL)
300 		*cp2++ = *cp++;
301 	*cp2 = '\0';
302 
303 	/*
304 	 * Look up the command; if not found, bitch.
305 	 * Normally, a blank command would map to the
306 	 * first command in the table; while sourcing,
307 	 * however, we ignore blank lines to eliminate
308 	 * confusion.
309 	 */
310 
311 	if (sourcing && *word == '\0')
312 		return (0);
313 	com = lex(word);
314 	if (com == NULL) {
315 		printf("Unknown command: \"%s\"\n", word);
316 		goto out;
317 	}
318 
319 	/*
320 	 * See if we should execute the command -- if a conditional
321 	 * we always execute it, otherwise, check the state of cond.
322 	 */
323 
324 	if ((com->c_argtype & F) == 0)
325 		if ((cond == CRCV && !rcvmode) || (cond == CSEND && rcvmode))
326 			return (0);
327 
328 	/*
329 	 * Process the arguments to the command, depending
330 	 * on the type he expects.  Default to an error.
331 	 * If we are sourcing an interactive command, it's
332 	 * an error.
333 	 */
334 
335 	if (!rcvmode && (com->c_argtype & M) == 0) {
336 		printf("May not execute \"%s\" while sending\n",
337 		    com->c_name);
338 		goto out;
339 	}
340 	if (sourcing && com->c_argtype & I) {
341 		printf("May not execute \"%s\" while sourcing\n",
342 		    com->c_name);
343 		goto out;
344 	}
345 	if (readonly && com->c_argtype & W) {
346 		printf("May not execute \"%s\" -- message file is read only\n",
347 		   com->c_name);
348 		goto out;
349 	}
350 	if (contxt && com->c_argtype & R) {
351 		printf("Cannot recursively invoke \"%s\"\n", com->c_name);
352 		goto out;
353 	}
354 	switch (com->c_argtype & ~(F|P|I|M|T|W|R)) {
355 	case MSGLIST:
356 		/*
357 		 * A message list defaulting to nearest forward
358 		 * legal message.
359 		 */
360 		if (msgvec == 0) {
361 			printf("Illegal use of \"message list\"\n");
362 			break;
363 		}
364 		if ((c = getmsglist(cp, msgvec, com->c_msgflag)) < 0)
365 			break;
366 		if (c  == 0) {
367 			*msgvec = first(com->c_msgflag, com->c_msgmask);
368 			msgvec[1] = 0;
369 		}
370 		if (*msgvec == 0) {
371 			printf("No applicable messages\n");
372 			break;
373 		}
374 		e = (*com->c_func)(msgvec);
375 		break;
376 
377 	case NDMLIST:
378 		/*
379 		 * A message list with no defaults, but no error
380 		 * if none exist.
381 		 */
382 		if (msgvec == 0) {
383 			printf("Illegal use of \"message list\"\n");
384 			break;
385 		}
386 		if (getmsglist(cp, msgvec, com->c_msgflag) < 0)
387 			break;
388 		e = (*com->c_func)(msgvec);
389 		break;
390 
391 	case STRLIST:
392 		/*
393 		 * Just the straight string, with
394 		 * leading blanks removed.
395 		 */
396 		while (isspace((unsigned char)*cp))
397 			cp++;
398 		e = (*com->c_func)(cp);
399 		break;
400 
401 	case RAWLIST:
402 		/*
403 		 * A vector of strings, in shell style.
404 		 */
405 		if ((c = getrawlist(cp, arglist,
406 		    sizeof(arglist) / sizeof(*arglist))) < 0)
407 			break;
408 		if (c < com->c_minargs) {
409 			printf("%s requires at least %d arg(s)\n",
410 			    com->c_name, com->c_minargs);
411 			break;
412 		}
413 		if (c > com->c_maxargs) {
414 			printf("%s takes no more than %d arg(s)\n",
415 			    com->c_name, com->c_maxargs);
416 			break;
417 		}
418 		e = (*com->c_func)(arglist);
419 		break;
420 
421 	case NOLIST:
422 		/*
423 		 * Just the constant zero, for exiting,
424 		 * eg.
425 		 */
426 		e = (*com->c_func)(0);
427 		break;
428 
429 	default:
430 		errx(1, "Unknown argtype");
431 	}
432 
433 out:
434 	/*
435 	 * Exit the current source file on
436 	 * error.
437 	 */
438 	if (e) {
439 		if (e < 0)
440 			return (1);
441 		if (loading)
442 			return (1);
443 		if (sourcing)
444 			unstack();
445 		return (0);
446 	}
447 	if (com == NULL)
448 		return (0);
449 	if (value("autoprint") != NULL && com->c_argtype & P)
450 		if ((dot->m_flag & MDELETED) == 0) {
451 			muvec[0] = dot - &message[0] + 1;
452 			muvec[1] = 0;
453 			type(muvec);
454 		}
455 	if (!sourcing && (com->c_argtype & T) == 0)
456 		sawcom = 1;
457 	return (0);
458 }
459 
460 /*
461  * Set the size of the message vector used to construct argument
462  * lists to message list functions.
463  */
464 void
setmsize(int sz)465 setmsize(int sz)
466 {
467 
468 	if (msgvec != NULL)
469 		(void)free(msgvec);
470 	msgvec = calloc((unsigned)(sz + 1), sizeof(*msgvec));
471 }
472 
473 /*
474  * Find the correct command in the command table corresponding
475  * to the passed command "word"
476  */
477 
478 const struct cmd *
lex(char word[])479 lex(char word[])
480 {
481 	const struct cmd *cp;
482 
483 	/*
484 	 * ignore trailing chars after `#'
485 	 *
486 	 * lines with beginning `#' are comments
487 	 * spaces before `#' are ignored in execute()
488 	 */
489 
490 	if (*word == '#')
491 	    *(word+1) = '\0';
492 
493 
494 	for (cp = &cmdtab[0]; cp->c_name != NULL; cp++)
495 		if (isprefix(word, cp->c_name))
496 			return (cp);
497 	return (NULL);
498 }
499 
500 /*
501  * Determine if as1 is a valid prefix of as2.
502  * Return true if yep.
503  */
504 int
isprefix(const char * as1,const char * as2)505 isprefix(const char *as1, const char *as2)
506 {
507 	const char *s1, *s2;
508 
509 	s1 = as1;
510 	s2 = as2;
511 	while (*s1++ == *s2)
512 		if (*s2++ == '\0')
513 			return (1);
514 	return (*--s1 == '\0');
515 }
516 
517 /*
518  * The following gets called on receipt of an interrupt.  This is
519  * to abort printout of a command, mainly.
520  * Dispatching here when command() is inactive crashes rcv.
521  * Close all open files except 0, 1, 2, and the temporary.
522  * Also, unstack all source files.
523  */
524 
525 static int	inithdr;		/* am printing startup headers */
526 
527 void
intr(int s __unused)528 intr(int s __unused)
529 {
530 
531 	noreset = 0;
532 	if (!inithdr)
533 		sawcom++;
534 	inithdr = 0;
535 	while (sourcing)
536 		unstack();
537 
538 	close_all_files();
539 
540 	if (image >= 0) {
541 		(void)close(image);
542 		image = -1;
543 	}
544 	fprintf(stderr, "Interrupt\n");
545 	reset(0);
546 }
547 
548 /*
549  * When we wake up after ^Z, reprint the prompt.
550  */
551 void
stop(int s)552 stop(int s)
553 {
554 	sig_t old_action = signal(s, SIG_DFL);
555 	sigset_t nset;
556 
557 	(void)sigemptyset(&nset);
558 	(void)sigaddset(&nset, s);
559 	(void)sigprocmask(SIG_UNBLOCK, &nset, NULL);
560 	(void)kill(0, s);
561 	(void)sigprocmask(SIG_BLOCK, &nset, NULL);
562 	(void)signal(s, old_action);
563 	if (reset_on_stop) {
564 		reset_on_stop = 0;
565 		reset(0);
566 	}
567 }
568 
569 /*
570  * Announce the presence of the current Mail version,
571  * give the message count, and print a header listing.
572  */
573 void
announce(void)574 announce(void)
575 {
576 	int vec[2], mdot;
577 
578 	mdot = newfileinfo(0);
579 	vec[0] = mdot;
580 	vec[1] = 0;
581 	dot = &message[mdot - 1];
582 	if (msgCount > 0 && value("noheader") == NULL) {
583 		inithdr++;
584 		headers(vec);
585 		inithdr = 0;
586 	}
587 }
588 
589 /*
590  * Announce information about the file we are editing.
591  * Return a likely place to set dot.
592  */
593 int
newfileinfo(int omsgCount)594 newfileinfo(int omsgCount)
595 {
596 	struct message *mp;
597 	int u, n, mdot, d, s;
598 	char fname[PATHSIZE+1], zname[PATHSIZE+1], *ename;
599 
600 	for (mp = &message[omsgCount]; mp < &message[msgCount]; mp++)
601 		if (mp->m_flag & MNEW)
602 			break;
603 	if (mp >= &message[msgCount])
604 		for (mp = &message[omsgCount]; mp < &message[msgCount]; mp++)
605 			if ((mp->m_flag & MREAD) == 0)
606 				break;
607 	if (mp < &message[msgCount])
608 		mdot = mp - &message[0] + 1;
609 	else
610 		mdot = omsgCount + 1;
611 	s = d = 0;
612 	for (mp = &message[0], n = 0, u = 0; mp < &message[msgCount]; mp++) {
613 		if (mp->m_flag & MNEW)
614 			n++;
615 		if ((mp->m_flag & MREAD) == 0)
616 			u++;
617 		if (mp->m_flag & MDELETED)
618 			d++;
619 		if (mp->m_flag & MSAVED)
620 			s++;
621 	}
622 	ename = mailname;
623 	if (getfold(fname, sizeof(fname) - 1) >= 0) {
624 		strcat(fname, "/");
625 		if (strncmp(fname, mailname, strlen(fname)) == 0) {
626 			(void)snprintf(zname, sizeof(zname), "+%s",
627 			    mailname + strlen(fname));
628 			ename = zname;
629 		}
630 	}
631 	printf("\"%s\": ", ename);
632 	if (msgCount == 1)
633 		printf("1 message");
634 	else
635 		printf("%d messages", msgCount);
636 	if (n > 0)
637 		printf(" %d new", n);
638 	if (u-n > 0)
639 		printf(" %d unread", u);
640 	if (d > 0)
641 		printf(" %d deleted", d);
642 	if (s > 0)
643 		printf(" %d saved", s);
644 	if (readonly)
645 		printf(" [Read only]");
646 	printf("\n");
647 	return (mdot);
648 }
649 
650 /*
651  * Print the current version number.
652  */
653 
654 int
pversion(void * arg __unused)655 pversion(void *arg __unused)
656 {
657 
658 	printf("Version %s\n", version);
659 	return (0);
660 }
661 
662 /*
663  * Load a file of user definitions.
664  */
665 void
load(char * name)666 load(char *name)
667 {
668 	FILE *in, *oldin;
669 
670 	if ((in = Fopen(name, "r")) == NULL)
671 		return;
672 	oldin = input;
673 	input = in;
674 	loading = 1;
675 	sourcing = 1;
676 	commands();
677 	loading = 0;
678 	sourcing = 0;
679 	input = oldin;
680 	(void)Fclose(in);
681 }
682