util.c revision 330897 
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 * 4. 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[] = "@(#)aux.c	8.1 (Berkeley) 6/6/93";
35#endif
36#endif /* not lint */
37#include <sys/cdefs.h>
38__FBSDID("$FreeBSD: stable/11/usr.bin/mail/util.c 330897 2018-03-14 03:19:51Z eadler $");
39
40#include <sys/time.h>
41
42#include <fcntl.h>
43
44#include "rcv.h"
45#include "extern.h"
46
47/*
48 * Mail -- a mail program
49 *
50 * Auxiliary functions.
51 */
52
53static char *save2str(char *, char *);
54
55/*
56 * Return a pointer to a dynamic copy of the argument.
57 */
58char *
59savestr(char *str)
60{
61	char *new;
62	int size = strlen(str) + 1;
63
64	if ((new = salloc(size)) != NULL)
65		bcopy(str, new, size);
66	return (new);
67}
68
69/*
70 * Make a copy of new argument incorporating old one.
71 */
72static char *
73save2str(char *str, char *old)
74{
75	char *new;
76	int newsize = strlen(str) + 1;
77	int oldsize = old ? strlen(old) + 1 : 0;
78
79	if ((new = salloc(newsize + oldsize)) != NULL) {
80		if (oldsize) {
81			bcopy(old, new, oldsize);
82			new[oldsize - 1] = ' ';
83		}
84		bcopy(str, new + oldsize, newsize);
85	}
86	return (new);
87}
88
89/*
90 * Touch the named message by setting its MTOUCH flag.
91 * Touched messages have the effect of not being sent
92 * back to the system mailbox on exit.
93 */
94void
95touch(struct message *mp)
96{
97
98	mp->m_flag |= MTOUCH;
99	if ((mp->m_flag & MREAD) == 0)
100		mp->m_flag |= MREAD|MSTATUS;
101}
102
103/*
104 * Test to see if the passed file name is a directory.
105 * Return true if it is.
106 */
107int
108isdir(char name[])
109{
110	struct stat sbuf;
111
112	if (stat(name, &sbuf) < 0)
113		return (0);
114	return (S_ISDIR(sbuf.st_mode));
115}
116
117/*
118 * Count the number of arguments in the given string raw list.
119 */
120int
121argcount(char **argv)
122{
123	char **ap;
124
125	for (ap = argv; *ap++ != NULL;)
126		;
127	return (ap - argv - 1);
128}
129
130/*
131 * Return the desired header line from the passed message
132 * pointer (or NULL if the desired header field is not available).
133 */
134char *
135hfield(const char *field, struct message *mp)
136{
137	FILE *ibuf;
138	char linebuf[LINESIZE];
139	int lc;
140	char *hfield;
141	char *colon, *oldhfield = NULL;
142
143	ibuf = setinput(mp);
144	if ((lc = mp->m_lines - 1) < 0)
145		return (NULL);
146	if (readline(ibuf, linebuf, LINESIZE) < 0)
147		return (NULL);
148	while (lc > 0) {
149		if ((lc = gethfield(ibuf, linebuf, lc, &colon)) < 0)
150			return (oldhfield);
151		if ((hfield = ishfield(linebuf, colon, field)) != NULL)
152			oldhfield = save2str(hfield, oldhfield);
153	}
154	return (oldhfield);
155}
156
157/*
158 * Return the next header field found in the given message.
159 * Return >= 0 if something found, < 0 elsewise.
160 * "colon" is set to point to the colon in the header.
161 * Must deal with \ continuations & other such fraud.
162 */
163int
164gethfield(FILE *f, char linebuf[], int rem, char **colon)
165{
166	char line2[LINESIZE];
167	char *cp, *cp2;
168	int c;
169
170	for (;;) {
171		if (--rem < 0)
172			return (-1);
173		if ((c = readline(f, linebuf, LINESIZE)) <= 0)
174			return (-1);
175		for (cp = linebuf; isprint((unsigned char)*cp) && *cp != ' ' && *cp != ':';
176		    cp++)
177			;
178		if (*cp != ':' || cp == linebuf)
179			continue;
180		/*
181		 * I guess we got a headline.
182		 * Handle wraparounding
183		 */
184		*colon = cp;
185		cp = linebuf + c;
186		for (;;) {
187			while (--cp >= linebuf && (*cp == ' ' || *cp == '\t'))
188				;
189			cp++;
190			if (rem <= 0)
191				break;
192			ungetc(c = getc(f), f);
193			if (c != ' ' && c != '\t')
194				break;
195			if ((c = readline(f, line2, LINESIZE)) < 0)
196				break;
197			rem--;
198			for (cp2 = line2; *cp2 == ' ' || *cp2 == '\t'; cp2++)
199				;
200			c -= cp2 - line2;
201			if (cp + c >= linebuf + LINESIZE - 2)
202				break;
203			*cp++ = ' ';
204			bcopy(cp2, cp, c);
205			cp += c;
206		}
207		*cp = 0;
208		return (rem);
209	}
210	/* NOTREACHED */
211}
212
213/*
214 * Check whether the passed line is a header line of
215 * the desired breed.  Return the field body, or 0.
216 */
217
218char*
219ishfield(char linebuf[], char *colon, const char *field)
220{
221	char *cp = colon;
222
223	*cp = 0;
224	if (strcasecmp(linebuf, field) != 0) {
225		*cp = ':';
226		return (0);
227	}
228	*cp = ':';
229	for (cp++; *cp == ' ' || *cp == '\t'; cp++)
230		;
231	return (cp);
232}
233
234/*
235 * Copy a string and lowercase the result.
236 * dsize: space left in buffer (including space for NULL)
237 */
238void
239istrncpy(char *dest, const char *src, size_t dsize)
240{
241
242	strlcpy(dest, src, dsize);
243	for (; *dest; dest++)
244		*dest = tolower((unsigned char)*dest);
245}
246
247/*
248 * The following code deals with input stacking to do source
249 * commands.  All but the current file pointer are saved on
250 * the stack.
251 */
252
253static	int	ssp;			/* Top of file stack */
254struct sstack {
255	FILE	*s_file;		/* File we were in. */
256	int	s_cond;			/* Saved state of conditionals */
257	int	s_loading;		/* Loading .mailrc, etc. */
258};
259#define	SSTACK_SIZE	64		/* XXX was NOFILE. */
260static struct sstack sstack[SSTACK_SIZE];
261
262/*
263 * Pushdown current input file and switch to a new one.
264 * Set the global flag "sourcing" so that others will realize
265 * that they are no longer reading from a tty (in all probability).
266 */
267int
268source(char **arglist)
269{
270	FILE *fi;
271	char *cp;
272
273	if ((cp = expand(*arglist)) == NULL)
274		return (1);
275	if ((fi = Fopen(cp, "r")) == NULL) {
276		warn("%s", cp);
277		return (1);
278	}
279	if (ssp >= SSTACK_SIZE - 1) {
280		printf("Too much \"sourcing\" going on.\n");
281		(void)Fclose(fi);
282		return (1);
283	}
284	sstack[ssp].s_file = input;
285	sstack[ssp].s_cond = cond;
286	sstack[ssp].s_loading = loading;
287	ssp++;
288	loading = 0;
289	cond = CANY;
290	input = fi;
291	sourcing++;
292	return (0);
293}
294
295/*
296 * Pop the current input back to the previous level.
297 * Update the "sourcing" flag as appropriate.
298 */
299int
300unstack(void)
301{
302	if (ssp <= 0) {
303		printf("\"Source\" stack over-pop.\n");
304		sourcing = 0;
305		return (1);
306	}
307	(void)Fclose(input);
308	if (cond != CANY)
309		printf("Unmatched \"if\"\n");
310	ssp--;
311	cond = sstack[ssp].s_cond;
312	loading = sstack[ssp].s_loading;
313	input = sstack[ssp].s_file;
314	if (ssp == 0)
315		sourcing = loading;
316	return (0);
317}
318
319/*
320 * Touch the indicated file.
321 * This is nifty for the shell.
322 */
323void
324alter(char *name)
325{
326	struct timespec ts[2];
327
328	(void)clock_gettime(CLOCK_REALTIME, &ts[0]);
329	ts[0].tv_sec++;
330	ts[1].tv_sec = 0;
331	ts[1].tv_nsec = UTIME_OMIT;
332	(void)utimensat(AT_FDCWD, name, ts, 0);
333}
334
335/*
336 * Get sender's name from this message.  If the message has
337 * a bunch of arpanet stuff in it, we may have to skin the name
338 * before returning it.
339 */
340char *
341nameof(struct message *mp, int reptype)
342{
343	char *cp, *cp2;
344
345	cp = skin(name1(mp, reptype));
346	if (reptype != 0 || charcount(cp, '!') < 2)
347		return (cp);
348	cp2 = strrchr(cp, '!');
349	cp2--;
350	while (cp2 > cp && *cp2 != '!')
351		cp2--;
352	if (*cp2 == '!')
353		return (cp2 + 1);
354	return (cp);
355}
356
357/*
358 * Start of a "comment".
359 * Ignore it.
360 */
361char *
362skip_comment(char *cp)
363{
364	int nesting = 1;
365
366	for (; nesting > 0 && *cp; cp++) {
367		switch (*cp) {
368		case '\\':
369			if (cp[1])
370				cp++;
371			break;
372		case '(':
373			nesting++;
374			break;
375		case ')':
376			nesting--;
377			break;
378		}
379	}
380	return (cp);
381}
382
383/*
384 * Skin an arpa net address according to the RFC 822 interpretation
385 * of "host-phrase."
386 */
387char *
388skin(char *name)
389{
390	char *nbuf, *bufend, *cp, *cp2;
391	int c, gotlt, lastsp;
392
393	if (name == NULL)
394		return (NULL);
395	if (strchr(name, '(') == NULL && strchr(name, '<') == NULL
396	    && strchr(name, ' ') == NULL)
397		return (name);
398
399	/* We assume that length(input) <= length(output) */
400	if ((nbuf = malloc(strlen(name) + 1)) == NULL)
401		err(1, "Out of memory");
402	gotlt = 0;
403	lastsp = 0;
404	bufend = nbuf;
405	for (cp = name, cp2 = bufend; (c = *cp++) != '\0'; ) {
406		switch (c) {
407		case '(':
408			cp = skip_comment(cp);
409			lastsp = 0;
410			break;
411
412		case '"':
413			/*
414			 * Start of a "quoted-string".
415			 * Copy it in its entirety.
416			 */
417			while ((c = *cp) != '\0') {
418				cp++;
419				if (c == '"')
420					break;
421				if (c != '\\')
422					*cp2++ = c;
423				else if ((c = *cp) != '\0') {
424					*cp2++ = c;
425					cp++;
426				}
427			}
428			lastsp = 0;
429			break;
430
431		case ' ':
432			if (cp[0] == 'a' && cp[1] == 't' && cp[2] == ' ')
433				cp += 3, *cp2++ = '@';
434			else
435			if (cp[0] == '@' && cp[1] == ' ')
436				cp += 2, *cp2++ = '@';
437			else
438				lastsp = 1;
439			break;
440
441		case '<':
442			cp2 = bufend;
443			gotlt++;
444			lastsp = 0;
445			break;
446
447		case '>':
448			if (gotlt) {
449				gotlt = 0;
450				while ((c = *cp) != '\0' && c != ',') {
451					cp++;
452					if (c == '(')
453						cp = skip_comment(cp);
454					else if (c == '"')
455						while ((c = *cp) != '\0') {
456							cp++;
457							if (c == '"')
458								break;
459							if (c == '\\' && *cp != '\0')
460								cp++;
461						}
462				}
463				lastsp = 0;
464				break;
465			}
466			/* FALLTHROUGH */
467
468		default:
469			if (lastsp) {
470				lastsp = 0;
471				*cp2++ = ' ';
472			}
473			*cp2++ = c;
474			if (c == ',' && !gotlt &&
475			    (*cp == ' ' || *cp == '"' || *cp == '<')) {
476				*cp2++ = ' ';
477				while (*cp == ' ')
478					cp++;
479				lastsp = 0;
480				bufend = cp2;
481			}
482		}
483	}
484	*cp2 = '\0';
485
486	if ((cp = realloc(nbuf, strlen(nbuf) + 1)) != NULL)
487		nbuf = cp;
488	return (nbuf);
489}
490
491/*
492 * Fetch the sender's name from the passed message.
493 * Reptype can be
494 *	0 -- get sender's name for display purposes
495 *	1 -- get sender's name for reply
496 *	2 -- get sender's name for Reply
497 */
498char *
499name1(struct message *mp, int reptype)
500{
501	char namebuf[LINESIZE];
502	char linebuf[LINESIZE];
503	char *cp, *cp2;
504	FILE *ibuf;
505	int first = 1;
506
507	if ((cp = hfield("from", mp)) != NULL)
508		return (cp);
509	if (reptype == 0 && (cp = hfield("sender", mp)) != NULL)
510		return (cp);
511	ibuf = setinput(mp);
512	namebuf[0] = '\0';
513	if (readline(ibuf, linebuf, LINESIZE) < 0)
514		return (savestr(namebuf));
515newname:
516	for (cp = linebuf; *cp != '\0' && *cp != ' '; cp++)
517		;
518	for (; *cp == ' ' || *cp == '\t'; cp++)
519		;
520	for (cp2 = &namebuf[strlen(namebuf)];
521	    *cp != '\0' && *cp != ' ' && *cp != '\t' &&
522	    cp2 < namebuf + LINESIZE - 1;)
523		*cp2++ = *cp++;
524	*cp2 = '\0';
525	if (readline(ibuf, linebuf, LINESIZE) < 0)
526		return (savestr(namebuf));
527	if ((cp = strchr(linebuf, 'F')) == NULL)
528		return (savestr(namebuf));
529	if (strncmp(cp, "From", 4) != 0)
530		return (savestr(namebuf));
531	while ((cp = strchr(cp, 'r')) != NULL) {
532		if (strncmp(cp, "remote", 6) == 0) {
533			if ((cp = strchr(cp, 'f')) == NULL)
534				break;
535			if (strncmp(cp, "from", 4) != 0)
536				break;
537			if ((cp = strchr(cp, ' ')) == NULL)
538				break;
539			cp++;
540			if (first) {
541				cp2 = namebuf;
542				first = 0;
543			} else
544				cp2 = strrchr(namebuf, '!') + 1;
545			strlcpy(cp2, cp, sizeof(namebuf) - (cp2 - namebuf) - 1);
546			strcat(namebuf, "!");
547			goto newname;
548		}
549		cp++;
550	}
551	return (savestr(namebuf));
552}
553
554/*
555 * Count the occurrences of c in str
556 */
557int
558charcount(char *str, int c)
559{
560	char *cp;
561	int i;
562
563	for (i = 0, cp = str; *cp != '\0'; cp++)
564		if (*cp == c)
565			i++;
566	return (i);
567}
568
569/*
570 * See if the given header field is supposed to be ignored.
571 */
572int
573isign(const char *field, struct ignoretab ignore[2])
574{
575	char realfld[LINESIZE];
576
577	if (ignore == ignoreall)
578		return (1);
579	/*
580	 * Lower-case the string, so that "Status" and "status"
581	 * will hash to the same place.
582	 */
583	istrncpy(realfld, field, sizeof(realfld));
584	if (ignore[1].i_count > 0)
585		return (!member(realfld, ignore + 1));
586	else
587		return (member(realfld, ignore));
588}
589
590int
591member(char *realfield, struct ignoretab *table)
592{
593	struct ignore *igp;
594
595	for (igp = table->i_head[hash(realfield)]; igp != NULL; igp = igp->i_link)
596		if (*igp->i_field == *realfield &&
597		    equal(igp->i_field, realfield))
598			return (1);
599	return (0);
600}
601