1/* Copyright 1988,1990,1993,1994 by Paul Vixie
2 * All rights reserved
3 *
4 * Distribute freely, except: don't remove my name from the source or
5 * documentation (don't take credit for my work), mark your changes (don't
6 * get me blamed for your possible bugs), don't alter or remove this
7 * notice.  May be sold if buildable source is provided to buyer.  No
8 * warrantee of any kind, express or implied, is included with this
9 * software; use at your own risk, responsibility for damages (if any) to
10 * anyone resulting from the use of this software rests entirely with the
11 * user.
12 *
13 * Send bug reports, bug fixes, enhancements, requests, flames, etc., and
14 * I'll try to keep a version up to date.  I can be reached as follows:
15 * Paul Vixie          <paul@vix.com>          uunet!decwrl!vixie!paul
16 */
17
18#if !defined(lint) && !defined(LINT)
19static const char rcsid[] =
20  "$FreeBSD: src/usr.sbin/cron/lib/misc.c,v 1.13 2005/08/24 17:51:36 pjd Exp $";
21#endif
22
23/* vix 26jan87 [RCS has the rest of the log]
24 * vix 30dec86 [written]
25 */
26
27
28#include "cron.h"
29#if SYS_TIME_H
30# include <sys/time.h>
31#else
32# include <time.h>
33#endif
34#include <sys/file.h>
35#include <sys/stat.h>
36#include <err.h>
37#include <errno.h>
38#include <string.h>
39#include <fcntl.h>
40#if defined(SYSLOG)
41# include <syslog.h>
42#endif
43
44
45#if defined(LOG_DAEMON) && !defined(LOG_CRON)
46#define LOG_CRON LOG_DAEMON
47#endif
48
49
50static int		LogFD = ERR;
51
52
53int
54strcmp_until(left, right, until)
55	char	*left;
56	char	*right;
57	int	until;
58{
59	register int	diff;
60
61	while (*left && *left != until && *left == *right) {
62		left++;
63		right++;
64	}
65
66	if ((*left=='\0' || *left == until) &&
67	    (*right=='\0' || *right == until)) {
68		diff = 0;
69	} else {
70		diff = *left - *right;
71	}
72
73	return diff;
74}
75
76
77/* strdtb(s) - delete trailing blanks in string 's' and return new length
78 */
79int
80strdtb(s)
81	char	*s;
82{
83	char	*x = s;
84
85	/* scan forward to the null
86	 */
87	while (*x)
88		x++;
89
90	/* scan backward to either the first character before the string,
91	 * or the last non-blank in the string, whichever comes first.
92	 */
93	do	{x--;}
94	while (x >= s && isspace(*x));
95
96	/* one character beyond where we stopped above is where the null
97	 * goes.
98	 */
99	*++x = '\0';
100
101	/* the difference between the position of the null character and
102	 * the position of the first character of the string is the length.
103	 */
104	return x - s;
105}
106
107
108int
109set_debug_flags(flags)
110	char	*flags;
111{
112	/* debug flags are of the form    flag[,flag ...]
113	 *
114	 * if an error occurs, print a message to stdout and return FALSE.
115	 * otherwise return TRUE after setting ERROR_FLAGS.
116	 */
117
118#if !DEBUGGING
119
120	printf("this program was compiled without debugging enabled\n");
121	return FALSE;
122
123#else /* DEBUGGING */
124
125	char	*pc = flags;
126
127	DebugFlags = 0;
128
129	while (*pc) {
130		char	**test;
131		int	mask;
132
133		/* try to find debug flag name in our list.
134		 */
135		for (	test = DebugFlagNames, mask = 1;
136			*test && strcmp_until(*test, pc, ',');
137			test++, mask <<= 1
138		    )
139			;
140
141		if (!*test) {
142			fprintf(stderr,
143				"unrecognized debug flag <%s> <%s>\n",
144				flags, pc);
145			return FALSE;
146		}
147
148		DebugFlags |= mask;
149
150		/* skip to the next flag
151		 */
152		while (*pc && *pc != ',')
153			pc++;
154		if (*pc == ',')
155			pc++;
156	}
157
158	if (DebugFlags) {
159		int	flag;
160
161		fprintf(stderr, "debug flags enabled:");
162
163		for (flag = 0;  DebugFlagNames[flag];  flag++)
164			if (DebugFlags & (1 << flag))
165				fprintf(stderr, " %s", DebugFlagNames[flag]);
166		fprintf(stderr, "\n");
167	}
168
169	return TRUE;
170
171#endif /* DEBUGGING */
172}
173
174
175void
176set_cron_uid()
177{
178#if defined(BSD) || defined(POSIX)
179	if (seteuid(ROOT_UID) < OK)
180		err(ERROR_EXIT, "seteuid");
181#else
182	if (setuid(ROOT_UID) < OK)
183		err(ERROR_EXIT, "setuid");
184#endif
185}
186
187
188void
189set_cron_cwd()
190{
191	struct stat	sb;
192
193	/* first check for CRONDIR ("/var/cron" or some such)
194	 */
195	if (stat(CRONDIR, &sb) < OK && errno == ENOENT) {
196		warn("%s", CRONDIR);
197		if (OK == mkdir(CRONDIR, 0700)) {
198			warnx("%s: created", CRONDIR);
199			stat(CRONDIR, &sb);
200		} else {
201			err(ERROR_EXIT, "%s: mkdir", CRONDIR);
202		}
203	}
204	if (!(sb.st_mode & S_IFDIR))
205		err(ERROR_EXIT, "'%s' is not a directory, bailing out", CRONDIR);
206	if (chdir(CRONDIR) < OK)
207		err(ERROR_EXIT, "cannot chdir(%s), bailing out", CRONDIR);
208
209	/* CRONDIR okay (now==CWD), now look at SPOOL_DIR ("tabs" or some such)
210	 */
211	if (stat(SPOOL_DIR, &sb) < OK && errno == ENOENT) {
212		warn("%s", SPOOL_DIR);
213		if (OK == mkdir(SPOOL_DIR, 0700)) {
214			warnx("%s: created", SPOOL_DIR);
215			stat(SPOOL_DIR, &sb);
216		} else {
217			err(ERROR_EXIT, "%s: mkdir", SPOOL_DIR);
218		}
219	}
220	if (!(sb.st_mode & S_IFDIR))
221		err(ERROR_EXIT, "'%s' is not a directory, bailing out", SPOOL_DIR);
222}
223
224
225/* get_char(file) : like getc() but increment LineNumber on newlines
226 */
227int
228get_char(file)
229	FILE	*file;
230{
231	int	ch;
232
233	ch = getc(file);
234	if (ch == '\n')
235		Set_LineNum(LineNumber + 1)
236	return ch;
237}
238
239
240/* unget_char(ch, file) : like ungetc but do LineNumber processing
241 */
242void
243unget_char(ch, file)
244	int	ch;
245	FILE	*file;
246{
247	ungetc(ch, file);
248	if (ch == '\n')
249		Set_LineNum(LineNumber - 1)
250}
251
252
253/* get_string(str, max, file, termstr) : like fgets() but
254 *		(1) has terminator string which should include \n
255 *		(2) will always leave room for the null
256 *		(3) uses get_char() so LineNumber will be accurate
257 *		(4) returns EOF or terminating character, whichever
258 */
259int
260get_string(string, size, file, terms)
261	char	*string;
262	int	size;
263	FILE	*file;
264	char	*terms;
265{
266	int	ch;
267
268	while (EOF != (ch = get_char(file)) && !strchr(terms, ch)) {
269		if (size > 1) {
270			*string++ = (char) ch;
271			size--;
272		}
273	}
274
275	if (size > 0)
276		*string = '\0';
277
278	return ch;
279}
280
281
282/* skip_comments(file) : read past comment (if any)
283 */
284void
285skip_comments(file)
286	FILE	*file;
287{
288	int	ch;
289
290	while (EOF != (ch = get_char(file))) {
291		/* ch is now the first character of a line.
292		 */
293
294		while (ch == ' ' || ch == '\t')
295			ch = get_char(file);
296
297		if (ch == EOF)
298			break;
299
300		/* ch is now the first non-blank character of a line.
301		 */
302
303		if (ch != '\n' && ch != '#')
304			break;
305
306		/* ch must be a newline or comment as first non-blank
307		 * character on a line.
308		 */
309
310		while (ch != '\n' && ch != EOF)
311			ch = get_char(file);
312
313		/* ch is now the newline of a line which we're going to
314		 * ignore.
315		 */
316	}
317	if (ch != EOF)
318		unget_char(ch, file);
319}
320
321
322/* int in_file(char *string, FILE *file)
323 *	return TRUE if one of the lines in file matches string exactly,
324 *	FALSE otherwise.
325 */
326static int
327in_file(string, file)
328	char *string;
329	FILE *file;
330{
331	char line[MAX_TEMPSTR];
332
333	rewind(file);
334	while (fgets(line, MAX_TEMPSTR, file)) {
335		if (line[0] != '\0')
336			if (line[strlen(line)-1] == '\n')
337				line[strlen(line)-1] = '\0';
338		if (0 == strcmp(line, string))
339			return TRUE;
340	}
341	return FALSE;
342}
343
344
345/* int allowed(char *username)
346 *	returns TRUE if (ALLOW_FILE exists and user is listed)
347 *	or (DENY_FILE exists and user is NOT listed)
348 *	or (neither file exists but user=="root" so it's okay)
349 */
350#ifdef __APPLE__
351int allowed(char* username, int allow_only_root)
352#else
353int
354allowed(username)
355	char *username;
356#endif /* __APPLE__ */
357{
358	FILE	*allow, *deny;
359	int	isallowed;
360
361	isallowed = FALSE;
362
363	deny = NULL;
364#if defined(ALLOW_FILE) && defined(DENY_FILE)
365	if ((allow = fopen(ALLOW_FILE, "r")) == NULL && errno != ENOENT)
366		goto out;
367	if ((deny = fopen(DENY_FILE, "r")) == NULL && errno != ENOENT)
368		goto out;
369	Debug(DMISC, ("allow/deny enabled, %d/%d\n", !!allow, !!deny))
370#else
371	allow = NULL;
372#endif
373
374	if (allow)
375		isallowed = in_file(username, allow);
376	else if (deny)
377		isallowed = !in_file(username, deny);
378	else {
379#ifdef __APPLE__
380		if (allow_only_root) {
381			isallowed = (strcmp(username, ROOT_USER) == 0);
382		} else {
383			isallowed = TRUE;
384		}
385#else
386#if defined(ALLOW_ONLY_ROOT)
387		isallowed = (strcmp(username, ROOT_USER) == 0);
388#else
389		isallowed = TRUE;
390#endif
391#endif
392	}
393out:	if (allow)
394		fclose(allow);
395	if (deny)
396		fclose(deny);
397	return (isallowed);
398}
399
400
401void
402log_it(username, xpid, event, detail)
403	char	*username;
404	int	xpid;
405	char	*event;
406	char	*detail;
407{
408	PID_T			pid = xpid;
409#if defined(LOG_FILE)
410	char			*msg;
411	TIME_T			now = time((TIME_T) 0);
412	register struct tm	*t = localtime(&now);
413#endif /*LOG_FILE*/
414
415#if defined(SYSLOG)
416	static int		syslog_open = 0;
417#endif
418
419#if defined(LOG_FILE)
420	/* we assume that MAX_TEMPSTR will hold the date, time, &punctuation.
421	 */
422	msg = malloc(strlen(username)
423		     + strlen(event)
424		     + strlen(detail)
425		     + MAX_TEMPSTR);
426
427	if (msg == NULL)
428		warnx("failed to allocate memory for log message");
429	else {
430		if (LogFD < OK) {
431			LogFD = open(LOG_FILE, O_WRONLY|O_APPEND|O_CREAT, 0600);
432			if (LogFD < OK) {
433				warn("can't open log file %s", LOG_FILE);
434			} else {
435				(void) fcntl(LogFD, F_SETFD, 1);
436			}
437		}
438
439		/* we have to sprintf() it because fprintf() doesn't always
440		 * write everything out in one chunk and this has to be
441		 * atomically appended to the log file.
442		 */
443		sprintf(msg, "%s (%02d/%02d-%02d:%02d:%02d-%d) %s (%s)\n",
444			username,
445			t->tm_mon+1, t->tm_mday, t->tm_hour, t->tm_min,
446			t->tm_sec, pid, event, detail);
447
448		/* we have to run strlen() because sprintf() returns (char*)
449		 * on old BSD.
450		 */
451		if (LogFD < OK || write(LogFD, msg, strlen(msg)) < OK) {
452			if (LogFD >= OK)
453				warn("%s", LOG_FILE);
454			warnx("can't write to log file");
455			write(STDERR, msg, strlen(msg));
456		}
457
458		free(msg);
459	}
460#endif /*LOG_FILE*/
461
462#if defined(SYSLOG)
463	if (!syslog_open) {
464		/* we don't use LOG_PID since the pid passed to us by
465		 * our client may not be our own.  therefore we want to
466		 * print the pid ourselves.
467		 */
468# ifdef LOG_DAEMON
469		openlog(ProgramName, LOG_PID, LOG_CRON);
470# else
471		openlog(ProgramName, LOG_PID);
472# endif
473		syslog_open = TRUE;		/* assume openlog success */
474	}
475
476	syslog(LOG_INFO, "(%s) %s (%s)\n", username, event, detail);
477
478#endif /*SYSLOG*/
479
480#if DEBUGGING
481	if (DebugFlags) {
482		fprintf(stderr, "log_it: (%s %d) %s (%s)\n",
483			username, pid, event, detail);
484	}
485#endif
486}
487
488
489void
490log_close() {
491	if (LogFD != ERR) {
492		close(LogFD);
493		LogFD = ERR;
494	}
495}
496
497
498/* two warnings:
499 *	(1) this routine is fairly slow
500 *	(2) it returns a pointer to static storage
501 */
502char *
503first_word(s, t)
504	register char *s;	/* string we want the first word of */
505	register char *t;	/* terminators, implicitly including \0 */
506{
507	static char retbuf[2][MAX_TEMPSTR + 1];	/* sure wish C had GC */
508	static int retsel = 0;
509	register char *rb, *rp;
510
511	/* select a return buffer */
512	retsel = 1-retsel;
513	rb = &retbuf[retsel][0];
514	rp = rb;
515
516	/* skip any leading terminators */
517	while (*s && (NULL != strchr(t, *s))) {
518		s++;
519	}
520
521	/* copy until next terminator or full buffer */
522	while (*s && (NULL == strchr(t, *s)) && (rp < &rb[MAX_TEMPSTR])) {
523		*rp++ = *s++;
524	}
525
526	/* finish the return-string and return it */
527	*rp = '\0';
528	return rb;
529}
530
531
532/* warning:
533 *	heavily ascii-dependent.
534 */
535void
536mkprint(dst, src, len)
537	register char *dst;
538	register unsigned char *src;
539	register int len;
540{
541	while (len-- > 0)
542	{
543		register unsigned char ch = *src++;
544
545		if (ch < ' ') {			/* control character */
546			*dst++ = '^';
547			*dst++ = ch + '@';
548		} else if (ch < 0177) {		/* printable */
549			*dst++ = ch;
550		} else if (ch == 0177) {	/* delete/rubout */
551			*dst++ = '^';
552			*dst++ = '?';
553		} else {			/* parity character */
554			sprintf(dst, "\\%03o", ch);
555			dst += 4;
556		}
557	}
558	*dst = '\0';
559}
560
561
562/* warning:
563 *	returns a pointer to malloc'd storage, you must call free yourself.
564 */
565char *
566mkprints(src, len)
567	register unsigned char *src;
568	register unsigned int len;
569{
570	register char *dst = malloc(len*4 + 1);
571
572	if (dst != NULL)
573		mkprint(dst, src, len);
574
575	return dst;
576}
577
578
579#ifdef MAIL_DATE
580/* Sat, 27 Feb 93 11:44:51 CST
581 * 123456789012345678901234567
582 */
583char *
584arpadate(clock)
585	time_t *clock;
586{
587	time_t t = clock ?*clock :time(0L);
588	struct tm *tm = localtime(&t);
589	static char ret[32];	/* zone name might be >3 chars */
590
591	if (tm->tm_year >= 100)
592		tm->tm_year += 1900;
593
594	(void) snprintf(ret, sizeof(ret), "%s, %2d %s %d %02d:%02d:%02d %s",
595		       DowNames[tm->tm_wday],
596		       tm->tm_mday,
597		       MonthNames[tm->tm_mon],
598		       tm->tm_year,
599		       tm->tm_hour,
600		       tm->tm_min,
601		       tm->tm_sec,
602		       TZONE(*tm));
603	return ret;
604}
605#endif /*MAIL_DATE*/
606
607
608#ifdef HAVE_SAVED_UIDS
609static int save_euid;
610int swap_uids() { save_euid = geteuid(); return seteuid(getuid()); }
611int swap_uids_back() { return seteuid(save_euid); }
612#else /*HAVE_SAVED_UIDS*/
613int swap_uids() { return setreuid(geteuid(), getuid()); }
614int swap_uids_back() { return swap_uids(); }
615#endif /*HAVE_SAVED_UIDS*/
616