xref: /netbsd-src/usr.bin/mail/support.c (revision c0179c282a5968435315a82f4128c61372c68fc3)
1 /*	$NetBSD: support.c,v 1.16 2006/10/31 20:07:32 christos 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
35 static char sccsid[] = "@(#)aux.c	8.1 (Berkeley) 6/6/93";
36 #else
37 __RCSID("$NetBSD: support.c,v 1.16 2006/10/31 20:07:32 christos Exp $");
38 #endif
39 #endif /* not lint */
40 
41 #include "rcv.h"
42 #include "extern.h"
43 #include "mime.h"
44 
45 /*
46  * Mail -- a mail program
47  *
48  * Auxiliary functions.
49  */
50 static char *save2str(char *, char *);
51 static int gethfield(FILE *, char [], int, char **); /* don't call this outside hfield()
52 							or decoding will not get done */
53 /*
54  * Return a pointer to a dynamic copy of the argument.
55  */
56 char *
57 savestr(const char *str)
58 {
59 	char *new;
60 	size_t size = strlen(str) + 1;
61 
62 	if ((new = salloc(size)) != NULL)
63 		(void)memmove(new, str, size);
64 	return new;
65 }
66 
67 /*
68  * Make a copy of new argument incorporating old one.
69  */
70 static char *
71 save2str(char *str, char *old)
72 {
73 	char *new;
74 	size_t newsize = strlen(str) + 1;
75 	size_t oldsize = old ? strlen(old) + 1 : 0;
76 
77 	if ((new = salloc(newsize + oldsize)) != NULL) {
78 		if (oldsize) {
79 			(void)memmove(new, old, oldsize);
80 			new[oldsize - 1] = ' ';
81 		}
82 		(void)memmove(new + oldsize, str, newsize);
83 	}
84 	return new;
85 }
86 
87 /*
88  * Touch the named message by setting its MTOUCH flag.
89  * Touched messages have the effect of not being sent
90  * back to the system mailbox on exit.
91  */
92 void
93 touch(struct message *mp)
94 {
95 
96 	mp->m_flag |= MTOUCH;
97 	if ((mp->m_flag & MREAD) == 0)
98 		mp->m_flag |= MREAD|MSTATUS;
99 }
100 
101 /*
102  * Test to see if the passed file name is a directory.
103  * Return true if it is.
104  */
105 int
106 isdir(const char name[])
107 {
108 	struct stat sbuf;
109 
110 	if (stat(name, &sbuf) < 0)
111 		return(0);
112 	return (S_ISDIR(sbuf.st_mode));
113 }
114 
115 /*
116  * Count the number of arguments in the given string raw list.
117  */
118 int
119 argcount(char **argv)
120 {
121 	char **ap;
122 
123 	for (ap = argv; *ap++ != NULL;)
124 		;
125 	return ap - argv - 1;
126 }
127 
128 /*
129  * Return the desired header line from the passed message
130  * pointer (or NULL if the desired header field is not available).
131  */
132 char *
133 hfield(const char field[], const struct message *mp)
134 {
135 	FILE *ibuf;
136 	char linebuf[LINESIZE];
137 	int lc;
138 	char *headerfield;
139 	char *colon, *oldhfield = NULL;
140 #ifdef MIME_SUPPORT
141 	int decode;
142 
143 	decode = value(ENAME_MIME_DECODE_MSG) &&
144 	    value(ENAME_MIME_DECODE_HDR);
145 #endif
146 
147 	ibuf = setinput(mp);
148 	if ((lc = mp->m_lines - 1) < 0)
149 		return NULL;
150 	if (mail_readline(ibuf, linebuf, LINESIZE) < 0)
151 		return NULL;
152 	while (lc > 0) {
153 		if ((lc = gethfield(ibuf, linebuf, lc, &colon)) < 0)
154 			return oldhfield;
155 #ifdef MIME_SUPPORT
156 		if ((headerfield = ishfield(linebuf, colon, field)) != NULL) {
157 			char linebuf2[LINESIZE];
158 			if (decode && colon)
159 				headerfield = mime_decode_hfield(linebuf2, sizeof(linebuf2), headerfield);
160 			oldhfield = save2str(headerfield, oldhfield);
161 		}
162 #else
163 		if ((headerfield = ishfield(linebuf, colon, field)) != NULL)
164 			oldhfield = save2str(headerfield, oldhfield);
165 #endif
166 	}
167 	return oldhfield;
168 }
169 
170 /*
171  * Return the next header field found in the given message.
172  * Return >= 0 if something found, < 0 elsewise.
173  * "colon" is set to point to the colon in the header.
174  * Must deal with \ continuations & other such fraud.
175  */
176 static int
177 gethfield(FILE *f, char linebuf[], int rem, char **colon)
178 {
179 	char line2[LINESIZE];
180 	char *cp, *cp2;
181 	int c;
182 
183 	for (;;) {
184 		if (--rem < 0)
185 			return -1;
186 		if ((c = mail_readline(f, linebuf, LINESIZE)) <= 0)
187 			return -1;
188 		for (cp = linebuf; isprint((unsigned char)*cp) && *cp != ' ' && *cp != ':';
189 		     cp++)
190 			;
191 		if (*cp != ':' || cp == linebuf)
192 			continue;
193 		/*
194 		 * I guess we got a headline.
195 		 * Handle wraparounding
196 		 */
197 		*colon = cp;
198 		cp = linebuf + c;
199 		for (;;) {
200 			while (--cp >= linebuf && (*cp == ' ' || *cp == '\t'))
201 				;
202 			cp++;
203 			if (rem <= 0)
204 				break;
205 			(void)ungetc(c = getc(f), f);
206 			if (c != ' ' && c != '\t')
207 				break;
208 			if ((c = mail_readline(f, line2, LINESIZE)) < 0)
209 				break;
210 			rem--;
211 			for (cp2 = line2; *cp2 == ' ' || *cp2 == '\t'; cp2++)
212 				;
213 			c -= cp2 - line2;
214 			if (cp + c >= linebuf + LINESIZE - 2)
215 				break;
216 			*cp++ = ' ';
217 			(void)memmove(cp, cp2, (size_t)c);
218 			cp += c;
219 		}
220 		*cp = 0;
221 		return rem;
222 	}
223 	/* NOTREACHED */
224 }
225 
226 /*
227  * Check whether the passed line is a header line of
228  * the desired breed.  Return the field body, or 0.
229  */
230 
231 char*
232 ishfield(const char linebuf[], char *colon, const char field[])
233 {
234 	char *cp = colon;
235 
236 	*cp = 0;
237 	if (strcasecmp(linebuf, field) != 0) {
238 		*cp = ':';
239 		return 0;
240 	}
241 	*cp = ':';
242 	for (cp++; *cp == ' ' || *cp == '\t'; cp++)
243 		;
244 	return cp;
245 }
246 
247 /*
248  * Copy a string, lowercasing it as we go.
249  */
250 void
251 istrcpy(char *dest, const char *src)
252 {
253 
254 	do {
255 		*dest++ = tolower((unsigned char)*src);
256 	} while (*src++ != 0);
257 }
258 
259 /*
260  * The following code deals with input stacking to do source
261  * commands.  All but the current file pointer are saved on
262  * the stack.
263  */
264 
265 static	int	ssp;			/* Top of file stack */
266 struct sstack {
267 	FILE	*s_file;		/* File we were in. */
268 	int	s_cond;			/* Saved state of conditionals */
269 	int	s_loading;		/* Loading .mailrc, etc. */
270 } sstack[NOFILE];
271 
272 /*
273  * Pushdown current input file and switch to a new one.
274  * Set the global flag "sourcing" so that others will realize
275  * that they are no longer reading from a tty (in all probability).
276  */
277 int
278 source(void *v)
279 {
280 	char **arglist = v;
281 	FILE *fi;
282 	const char *cp;
283 
284 	if ((cp = expand(*arglist)) == NULL)
285 		return(1);
286 	if ((fi = Fopen(cp, "r")) == NULL) {
287 		warn("%s", cp);
288 		return(1);
289 	}
290 	if (ssp >= NOFILE - 1) {
291 		(void)printf("Too much \"sourcing\" going on.\n");
292 		(void)Fclose(fi);
293 		return(1);
294 	}
295 	sstack[ssp].s_file = input;
296 	sstack[ssp].s_cond = cond;
297 	sstack[ssp].s_loading = loading;
298 	ssp++;
299 	loading = 0;
300 	cond = CANY;
301 	input = fi;
302 	sourcing++;
303 	return(0);
304 }
305 
306 /*
307  * Pop the current input back to the previous level.
308  * Update the "sourcing" flag as appropriate.
309  */
310 int
311 unstack(void)
312 {
313 	if (ssp <= 0) {
314 		(void)printf("\"Source\" stack over-pop.\n");
315 		sourcing = 0;
316 		return(1);
317 	}
318 	(void)Fclose(input);
319 	if (cond != CANY)
320 		(void)printf("Unmatched \"if\"\n");
321 	ssp--;
322 	cond = sstack[ssp].s_cond;
323 	loading = sstack[ssp].s_loading;
324 	input = sstack[ssp].s_file;
325 	if (ssp == 0)
326 		sourcing = loading;
327 	return(0);
328 }
329 
330 /*
331  * Touch the indicated file.
332  * This is nifty for the shell.
333  */
334 void
335 alter(char *name)
336 {
337 	struct stat sb;
338 	struct timeval tv[2];
339 
340 	if (stat(name, &sb))
341 		return;
342 	(void)gettimeofday(&tv[0], NULL);
343 	tv[0].tv_sec++;
344 	TIMESPEC_TO_TIMEVAL(&tv[1], &sb.st_mtimespec);
345 	(void)utimes(name, tv);
346 }
347 
348 /*
349  * Examine the passed line buffer and
350  * return true if it is all blanks and tabs.
351  */
352 int
353 blankline(char linebuf[])
354 {
355 	char *cp;
356 
357 	for (cp = linebuf; *cp; cp++)
358 		if (*cp != ' ' && *cp != '\t')
359 			return(0);
360 	return(1);
361 }
362 
363 /*
364  * Get sender's name from this message.  If the message has
365  * a bunch of arpanet stuff in it, we may have to skin the name
366  * before returning it.
367  */
368 char *
369 nameof(struct message *mp, int reptype)
370 {
371 	char *cp, *cp2;
372 
373 	cp = skin(name1(mp, reptype));
374 	if (reptype != 0 || charcount(cp, '!') < 2)
375 		return(cp);
376 	cp2 = strrchr(cp, '!');
377 	cp2--;
378 	while (cp2 > cp && *cp2 != '!')
379 		cp2--;
380 	if (*cp2 == '!')
381 		return(cp2 + 1);
382 	return(cp);
383 }
384 
385 /*
386  * Start of a "comment".
387  * Ignore it.
388  */
389 char *
390 skip_comment(char *cp)
391 {
392 	int nesting = 1;
393 
394 	for (; nesting > 0 && *cp; cp++) {
395 		switch (*cp) {
396 		case '\\':
397 			if (cp[1])
398 				cp++;
399 			break;
400 		case '(':
401 			nesting++;
402 			break;
403 		case ')':
404 			nesting--;
405 			break;
406 		}
407 	}
408 	return cp;
409 }
410 
411 /*
412  * Skin an arpa net address according to the RFC 822 interpretation
413  * of "host-phrase."
414  */
415 char *
416 skin(char *name)
417 {
418 	int c;
419 	char *cp, *cp2;
420 	char *bufend;
421 	int gotlt, lastsp;
422 	char nbuf[BUFSIZ];
423 
424 	if (name == NULL)
425 		return(NULL);
426 	if (strchr(name, '(') == NULL && strchr(name, '<') == NULL
427 	    && strchr(name, ' ') == NULL)
428 		return(name);
429 	gotlt = 0;
430 	lastsp = 0;
431 	bufend = nbuf;
432 	for (cp = name, cp2 = bufend; (c = *cp++) != '\0'; /* EMPTY */) {
433 		switch (c) {
434 		case '(':
435 			cp = skip_comment(cp);
436 			lastsp = 0;
437 			break;
438 
439 		case '"':
440 			/*
441 			 * Start of a "quoted-string".
442 			 * Copy it in its entirety.
443 			 */
444 			while ((c = *cp) != '\0') {
445 				cp++;
446 				if (c == '"')
447 					break;
448 				if (c != '\\')
449 					*cp2++ = c;
450 				else if ((c = *cp) != '\0') {
451 					*cp2++ = c;
452 					cp++;
453 				}
454 			}
455 			lastsp = 0;
456 			break;
457 
458 		case ' ':
459 			if (cp[0] == 'a' && cp[1] == 't' && cp[2] == ' ')
460 				cp += 3, *cp2++ = '@';
461 			else
462 			if (cp[0] == '@' && cp[1] == ' ')
463 				cp += 2, *cp2++ = '@';
464 			else
465 				lastsp = 1;
466 			break;
467 
468 		case '<':
469 			cp2 = bufend;
470 			gotlt++;
471 			lastsp = 0;
472 			break;
473 
474 		case '>':
475 			if (gotlt) {
476 				gotlt = 0;
477 				while ((c = *cp) && c != ',') {
478 					cp++;
479 					if (c == '(')
480 						cp = skip_comment(cp);
481 					else if (c == '"')
482 						while ((c = *cp) != '\0') {
483 							cp++;
484 							if (c == '"')
485 								break;
486 							if (c == '\\' && *cp)
487 								cp++;
488 						}
489 				}
490 				lastsp = 0;
491 				break;
492 			}
493 			/* FALLTHROUGH */
494 
495 		default:
496 			if (lastsp) {
497 				lastsp = 0;
498 				*cp2++ = ' ';
499 			}
500 			*cp2++ = c;
501 			if (c == ',' && !gotlt) {
502 				*cp2++ = ' ';
503 				for (; *cp == ' '; cp++)
504 					;
505 				lastsp = 0;
506 				bufend = cp2;
507 			}
508 		}
509 	}
510 	*cp2 = 0;
511 
512 	return(savestr(nbuf));
513 }
514 
515 /*
516  * Fetch the sender's name from the passed message.
517  * Reptype can be
518  *	0 -- get sender's name for display purposes
519  *	1 -- get sender's name for reply
520  *	2 -- get sender's name for Reply
521  */
522 char *
523 name1(struct message *mp, int reptype)
524 {
525 	char namebuf[LINESIZE];
526 	char linebuf[LINESIZE];
527 	char *cp, *cp2;
528 	FILE *ibuf;
529 	int firstrun = 1;
530 
531 	if ((cp = hfield("from", mp)) != NULL)
532 		return cp;
533 	if (reptype == 0 && (cp = hfield("sender", mp)) != NULL)
534 		return cp;
535 	ibuf = setinput(mp);
536 	namebuf[0] = '\0';
537 	if (mail_readline(ibuf, linebuf, LINESIZE) < 0)
538 		return(savestr(namebuf));
539 newname:
540 	for (cp = linebuf; *cp && *cp != ' '; cp++)
541 		;
542 	for (; *cp == ' ' || *cp == '\t'; cp++)
543 		;
544 	for (cp2 = &namebuf[strlen(namebuf)];
545 	     *cp && *cp != ' ' && *cp != '\t' && cp2 < namebuf + LINESIZE - 1;)
546 		*cp2++ = *cp++;
547 	*cp2 = '\0';
548 	if (mail_readline(ibuf, linebuf, LINESIZE) < 0)
549 		return(savestr(namebuf));
550 	if ((cp = strchr(linebuf, 'F')) == NULL)
551 		return(savestr(namebuf));
552 	if (strncmp(cp, "From", 4) != 0)
553 		return(savestr(namebuf));
554 	while ((cp = strchr(cp, 'r')) != NULL) {
555 		if (strncmp(cp, "remote", 6) == 0) {
556 			if ((cp = strchr(cp, 'f')) == NULL)
557 				break;
558 			if (strncmp(cp, "from", 4) != 0)
559 				break;
560 			if ((cp = strchr(cp, ' ')) == NULL)
561 				break;
562 			cp++;
563 			if (firstrun) {
564 				cp2 = namebuf;
565 				firstrun = 0;
566 			} else
567 				cp2 = strrchr(namebuf, '!') + 1;
568 			while (*cp && cp2 < namebuf + LINESIZE - 1)
569 				*cp2++ = *cp++;
570 			if (cp2 < namebuf + LINESIZE - 1)
571 				*cp2++ = '!';
572 			*cp2 = '\0';
573 			if (cp2 < namebuf + LINESIZE - 1)
574 				goto newname;
575 			else
576 				break;
577 		}
578 		cp++;
579 	}
580 	return(savestr(namebuf));
581 }
582 
583 /*
584  * Count the occurrences of c in str
585  */
586 int
587 charcount(char *str, int c)
588 {
589 	char *cp;
590 	int i;
591 
592 	for (i = 0, cp = str; *cp; cp++)
593 		if (*cp == c)
594 			i++;
595 	return(i);
596 }
597 
598 /*
599  * Convert c to upper case
600  */
601 int
602 upcase(int c)
603 {
604 
605 	if (islower(c))
606 		return toupper(c);
607 	return c;
608 }
609 
610 /*
611  * Copy s1 to s2, return pointer to null in s2.
612  */
613 char *
614 copy(char *s1, char *s2)
615 {
616 
617 	while ((*s2++ = *s1++) != '\0')
618 		;
619 	return s2 - 1;
620 }
621 
622 /*
623  * See if the given header field is supposed to be ignored.
624  */
625 int
626 isign(const char *field, struct ignoretab ignoretabs[2])
627 {
628 	char realfld[LINESIZE];
629 
630 	if (ignoretabs == ignoreall)
631 		return 1;
632 	/*
633 	 * Lower-case the string, so that "Status" and "status"
634 	 * will hash to the same place.
635 	 */
636 	istrcpy(realfld, field);
637 	if (ignoretabs[1].i_count > 0)
638 		return (!member(realfld, ignoretabs + 1));
639 	else
640 		return (member(realfld, ignoretabs));
641 }
642 
643 int
644 member(char *realfield, struct ignoretab *table)
645 {
646 	struct ignore *igp;
647 
648 	for (igp = table->i_head[hash(realfield)]; igp != 0; igp = igp->i_link)
649 		if (*igp->i_field == *realfield &&
650 		    equal(igp->i_field, realfield))
651 			return (1);
652 	return (0);
653 }
654