xref: /netbsd-src/usr.bin/calendar/calendar.c (revision de4fa6c51a9708fc05f88b618fa6fad87c9508ec)
1 /*	$NetBSD: calendar.c,v 1.47 2008/09/30 05:51:41 dholland Exp $	*/
2 
3 /*
4  * Copyright (c) 1989, 1993, 1994
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 __COPYRIGHT("@(#) Copyright (c) 1989, 1993\
35  The Regents of the University of California.  All rights reserved.");
36 #endif /* not lint */
37 
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)calendar.c	8.4 (Berkeley) 1/7/95";
41 #endif
42 __RCSID("$NetBSD: calendar.c,v 1.47 2008/09/30 05:51:41 dholland Exp $");
43 #endif /* not lint */
44 
45 #include <sys/param.h>
46 #include <sys/time.h>
47 #include <sys/stat.h>
48 #include <sys/uio.h>
49 #include <sys/wait.h>
50 
51 #include <ctype.h>
52 #include <err.h>
53 #include <errno.h>
54 #include <fcntl.h>
55 #include <pwd.h>
56 #include <stdbool.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <time.h>
61 #include <tzfile.h>
62 #include <unistd.h>
63 
64 #include "pathnames.h"
65 
66 static unsigned short lookahead = 1;
67 static unsigned short weekend = 2;
68 static char *fname = NULL;
69 static char *datestr = NULL;
70 static const char *defaultnames[] = {"calendar", ".calendar", _PATH_SYSTEM_CALENDAR, NULL};
71 static struct passwd *pw;
72 static char path[MAXPATHLEN + 1];
73 static bool doall = false;
74 static bool cpp_restricted = false;
75 
76 /* 1-based month, 0-based days, cumulative */
77 static const int daytab[][14] = {
78 	{ 0, -1, 30, 58, 89, 119, 150, 180, 211, 242, 272, 303, 333, 364 },
79 	{ 0, -1, 30, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
80 };
81 static struct tm *tp;
82 static const int *cumdays;
83 static int offset, yrdays;
84 static char dayname[10];
85 
86 static struct iovec header[] = {
87 	{ __UNCONST("From: "), 6 },
88 	{ NULL, 0 },
89 	{ __UNCONST(" (Reminder Service)\nTo: "), 24 },
90 	{ NULL, 0 },
91 	{ __UNCONST("\nSubject: "), 10 },
92 	{ NULL, 0 },
93 	{ __UNCONST("'s Calendar\nPrecedence: bulk\n\n"),  30 },
94 };
95 
96 static const char *days[] = {
97 	"sun", "mon", "tue", "wed", "thu", "fri", "sat", NULL,
98 };
99 
100 static const char *months[] = {
101 	"jan", "feb", "mar", "apr", "may", "jun",
102 	"jul", "aug", "sep", "oct", "nov", "dec", NULL,
103 };
104 
105 static void	 atodays(int, char *, unsigned short *);
106 static void	 cal(void);
107 static void	 closecal(FILE *);
108 static int	 getday(char *);
109 static int	 getfield(char *, char **, int *);
110 static void	 getmmdd(struct tm *, char *);
111 static int	 getmonth(char *);
112 static bool	 isnow(char *);
113 static FILE	*opencal(void);
114 static void	 settime(void);
115 static void	 usage(void) __dead;
116 
117 int
118 main(int argc, char **argv)
119 {
120 	int ch;
121 	const char *caldir;
122 
123 	(void)setprogname(argv[0]);	/* for portability */
124 
125 	while ((ch = getopt(argc, argv, "-ad:f:l:w:x")) != -1) {
126 		switch (ch) {
127 		case '-':		/* backward contemptible */
128 		case 'a':
129 			if (getuid()) {
130 				errno = EPERM;
131 				err(EXIT_FAILURE, NULL);
132 			}
133 			doall = true;
134 			break;
135 		case 'd':
136 			datestr = optarg;
137 			break;
138 		case 'f':
139 			fname = optarg;
140 			break;
141 		case 'l':
142 			atodays(ch, optarg, &lookahead);
143 			break;
144 		case 'w':
145 			atodays(ch, optarg, &weekend);
146 			break;
147 		case 'x':
148 			cpp_restricted = true;
149 			break;
150 		case '?':
151 		default:
152 			usage();
153 		}
154 	}
155 	argc -= optind;
156 	argv += optind;
157 
158 	if (argc)
159 		usage();
160 
161 	settime();
162 	if (doall) {
163 		/*
164 		 * XXX - This ignores the user's CALENDAR_DIR variable.
165 		 *       Run under user's login shell?
166 		 */
167 		while ((pw = getpwent()) != NULL) {
168 			(void)setegid(pw->pw_gid);
169 			(void)seteuid(pw->pw_uid);
170 			if (chdir(pw->pw_dir) != -1)
171 				cal();
172 			(void)seteuid(0);
173 		}
174 	} else if ((caldir = getenv("CALENDAR_DIR")) != NULL) {
175 		if (chdir(caldir) != -1)
176 			cal();
177 	} else if ((pw = getpwuid(geteuid())) != NULL) {
178 		if (chdir(pw->pw_dir) != -1)
179 			cal();
180 	}
181 	return 0;
182 }
183 
184 static void
185 cal(void)
186 {
187 	bool printing;
188 	FILE *fp;
189 	char *line;
190 
191 	if ((fp = opencal()) == NULL)
192 		return;
193 	printing = false;
194 	while ((line = fparseln(stdin,
195 		    NULL, NULL, NULL, FPARSELN_UNESCCOMM)) != NULL) {
196 		if (line[0] == '\0')
197 			continue;
198 		if (line[0] != '\t')
199 			printing = isnow(line);
200 		if (printing)
201 			(void)fprintf(fp, "%s\n", line);
202 		free(line);
203 
204 	}
205 	closecal(fp);
206 }
207 
208 static void
209 settime(void)
210 {
211 	time_t now;
212 
213 	(void)time(&now);
214 	tp = localtime(&now);
215 	if (datestr)
216 		getmmdd(tp, datestr);
217 
218 	if (isleap(tp->tm_year + TM_YEAR_BASE)) {
219 		yrdays = DAYSPERLYEAR;
220 		cumdays = daytab[1];
221 	} else {
222 		yrdays = DAYSPERNYEAR;
223 		cumdays = daytab[0];
224 	}
225 	/* Friday displays Monday's events */
226 	offset = tp->tm_wday == 5 ? lookahead + weekend : lookahead;
227 	header[5].iov_base = dayname;
228 	header[5].iov_len = strftime(dayname, sizeof(dayname), "%A", tp);
229 }
230 
231 /*
232  * Possible date formats include any combination of:
233  *	3-charmonth			(January, Jan, Jan)
234  *	3-charweekday			(Friday, Monday, mon.)
235  *	numeric month or day		(1, 2, 04)
236  *
237  * Any character may separate them, or they may not be separated.  Any line,
238  * following a line that is matched, that starts with "whitespace", is shown
239  * along with the matched line.
240  */
241 static bool
242 isnow(char *endp)
243 {
244 	int day;
245 	int flags;
246 	int month;
247 	int v1;
248 	int v2;
249 
250 #define	F_ISMONTH	0x01
251 #define	F_ISDAY		0x02
252 #define F_WILDMONTH	0x04
253 #define F_WILDDAY	0x08
254 
255 	flags = 0;
256 
257 	/* didn't recognize anything, skip it */
258 	if (!(v1 = getfield(endp, &endp, &flags)))
259 		return false;
260 
261 	if (flags & F_ISDAY || v1 > 12) {
262 		/* found a day */
263 		day = v1;
264 		/* if no recognizable month, assume wildcard ('*') month */
265 		if ((month = getfield(endp, &endp, &flags)) == 0) {
266 			flags |= F_ISMONTH | F_WILDMONTH;
267 			month = tp->tm_mon + 1;
268 		}
269 	} else if (flags & F_ISMONTH) {
270 		month = v1;
271 		/* if no recognizable day, assume the first */
272 		if ((day = getfield(endp, &endp, &flags)) == 0)
273 			day = 1;
274 	} else {
275 		v2 = getfield(endp, &endp, &flags);
276 		if (flags & F_ISMONTH) {
277 			day = v1;
278 			month = v2;
279 		} else {
280 			/* F_ISDAY set, v2 > 12, or no way to tell */
281 			month = v1;
282 			/* if no recognizable day, assume the first */
283 			day = v2 ? v2 : 1;
284 		}
285 	}
286 	/* if month is out of range, treat it as '*' */
287 	if (month < 1 || month > 12) {
288 		flags |= F_ISMONTH | F_WILDMONTH;
289 		month = tp->tm_mon + 1;
290 	}
291 
292 	if (flags & F_WILDMONTH && flags & F_WILDDAY)
293 		return true;
294 
295 	if (flags & F_WILDMONTH && flags & F_ISDAY && day == tp->tm_mday)
296 		return true;
297 
298 	if (flags & F_ISMONTH && flags & F_WILDDAY && month == tp->tm_mon + 1)
299 		return true;
300 
301 	if (flags & F_ISDAY)
302 		day = tp->tm_mday + (((day - 1) - tp->tm_wday + 7) % 7);
303 	day = cumdays[month] + day;
304 
305 	/* if today or today + offset days */
306 	if (day >= tp->tm_yday && day <= tp->tm_yday + offset)
307 		return true;
308 
309 	/* if number of days left in this year + days to event in next year */
310 	if (yrdays - tp->tm_yday + day <= offset)
311 		return true;
312 
313 	return false;
314 }
315 
316 static int
317 getfield(char *p, char **endp, int *flags)
318 {
319 	int val;
320 	char *start;
321 	char savech;
322 
323 #define FLDCHAR(a) (*p != '\0' && !isdigit((unsigned char)*p) && \
324     !isalpha((unsigned char)*p) && *p != '*')
325 
326 	for (/*EMPTY*/; FLDCHAR(*p); ++p)
327 		continue;
328 	if (*p == '*') {			/* `*' is current month */
329 		if (!(*flags & F_ISMONTH)) {
330 			*flags |= F_ISMONTH | F_WILDMONTH;
331 			*endp = p + 1;
332 			return tp->tm_mon + 1;
333 		} else {
334 			*flags |= F_ISDAY | F_WILDDAY;
335 			*endp = p + 1;
336 			return 1;
337 		}
338 	}
339 	if (isdigit((unsigned char)*p)) {
340 		val = (int)strtol(p, &p, 10);	/* if 0, it's failure */
341 		for (/*EMPTY*/; FLDCHAR(*p); ++p)
342 			continue;
343 		*endp = p;
344 		return val;
345 	}
346 	for (start = p; *p != '\0' && isalpha((unsigned char)*++p); /*EMPTY*/)
347 		continue;
348 	savech = *p;
349 	*p = '\0';
350 	if ((val = getmonth(start)) != 0)
351 		*flags |= F_ISMONTH;
352 	else if ((val = getday(start)) != 0)
353 		*flags |= F_ISDAY;
354 	else {
355 		*p = savech;
356 		return 0;
357 	}
358 	for (*p = savech; FLDCHAR(*p); ++p)
359 		continue;
360 	*endp = p;
361 	return val;
362 }
363 
364 static FILE *
365 opencal(void)
366 {
367 	int fd;
368 	int pdes[2];
369 	const char **name;
370 
371 	/* open up calendar file as stdin */
372 	if (fname == NULL) {
373 		for (name = defaultnames; *name != NULL; name++) {
374 			if (freopen(*name, "rf", stdin) == NULL)
375 				continue;
376 			else
377 				break;
378 		}
379 		if (*name == NULL) {
380 			if (doall)
381 				return NULL;
382 			err(EXIT_FAILURE, "Cannot open calendar file");
383 		}
384 	} else if (freopen(fname, "rf", stdin) == NULL) {
385 		if (doall)
386 			return NULL;
387 		err(EXIT_FAILURE, "Cannot open `%s'", fname);
388 	}
389 
390 	if (pipe(pdes) == -1) {
391 		warn("Cannot open pipe");
392 		return NULL;
393 	}
394 
395 	switch (fork()) {
396 	case -1:
397 		/* error */
398 		(void)close(pdes[0]);
399 		(void)close(pdes[1]);
400 		return NULL;
401 	case 0:
402 		/* child -- stdin already setup, set stdout to pipe input */
403 		if (pdes[1] != STDOUT_FILENO) {
404 			(void)dup2(pdes[1], STDOUT_FILENO);
405 			(void)close(pdes[1]);
406 		}
407 		(void)close(pdes[0]);
408 		/* tell CPP to only open regular files */
409 		if(!cpp_restricted && setenv("CPP_RESTRICTED", "", 1) == -1)
410 			err(EXIT_FAILURE, "Cannot restrict cpp");
411 		cpp_restricted = true;
412 
413 		(void)execl(_PATH_CPP, "cpp", "-traditional", "-P", "-I.",
414 		    "-I" _PATH_CALENDARS, NULL);
415 		err(EXIT_FAILURE, "Cannot exec `%s'", _PATH_CPP);
416 		/*NOTREACHED*/
417 	default:
418 		/* parent -- set stdin to pipe output */
419 		(void)dup2(pdes[0], STDIN_FILENO);
420 		(void)close(pdes[0]);
421 		(void)close(pdes[1]);
422 
423 		/* not reading all calendar files, just set output to stdout */
424 		if (!doall)
425 			return stdout;
426 
427 		/*
428 		 * Set output to a temporary file, so if no output
429 		 * don't send mail.
430 		 */
431 		(void)snprintf(path, sizeof(path), "%s/_calXXXXXX", _PATH_TMP);
432 		if ((fd = mkstemp(path)) == -1) {
433 			warn("Cannot create temporary file");
434 			return NULL;
435 		}
436 		return fdopen(fd, "w+");
437 	}
438 	/*NOTREACHED*/
439 }
440 
441 static void
442 closecal(FILE *fp)
443 {
444 	struct stat sbuf;
445 	ssize_t nread;
446 	int pdes[2];
447 	int status;
448 	char buf[1024];
449 
450 	if (!doall)
451 		return;
452 
453 	(void)rewind(fp);
454 	if (fstat(fileno(fp), &sbuf) == -1 || sbuf.st_size == 0)
455 		goto done;
456 	if (pipe(pdes) == -1)
457 		goto done;
458 
459 	switch (fork()) {
460 	case -1:
461 		/* error */
462 		(void)close(pdes[0]);
463 		(void)close(pdes[1]);
464 		break;
465 	case 0:
466 		/* child -- set stdin to pipe output */
467 		if (pdes[0] != STDIN_FILENO) {
468 			(void)dup2(pdes[0], STDIN_FILENO);
469 			(void)close(pdes[0]);
470 		}
471 		(void)close(pdes[1]);
472 		(void)execl(_PATH_SENDMAIL, "sendmail", "-i", "-t", "-F",
473 		    "\"Reminder Service\"", "-f", "root", NULL);
474 		err(EXIT_FAILURE, "Cannot exec `%s'", _PATH_SENDMAIL);
475 		/*NOTREACHED*/
476 	default:
477 		/* parent -- write to pipe input */
478 		(void)close(pdes[0]);
479 
480 		header[1].iov_base = header[3].iov_base = (void *)pw->pw_name;
481 		header[1].iov_len = header[3].iov_len = strlen(pw->pw_name);
482 		(void)writev(pdes[1], header, 7);
483 		while ((nread = read(fileno(fp), buf, sizeof(buf))) > 0)
484 			(void)write(pdes[1], buf, (size_t)nread);
485 		(void)close(pdes[1]);
486 		break;
487 	}
488 
489 done:	(void)fclose(fp);
490 	(void)unlink(path);
491 	while (wait(&status) != -1)
492 		continue;
493 }
494 
495 static int
496 getmonth(char *s)
497 {
498 	const char **p;
499 
500 	for (p = months; *p; ++p)
501 		if (strncasecmp(s, *p, 3) == 0)
502 			return (int)(p - months) + 1;
503 	return 0;
504 }
505 
506 static int
507 getday(char *s)
508 {
509 	const char **p;
510 
511 	for (p = days; *p; ++p)
512 		if (strncasecmp(s, *p, 3) == 0)
513 			return (int)(p - days) + 1;
514 	return 0;
515 }
516 
517 static void
518 atodays(int ch, char *arg, unsigned short *rvp)
519 {
520 	int u;
521 
522 	u = atoi(arg);
523 	if (u < 0 || u > 366)
524 		warnx("-%c %d out of range 0-366, ignored.", ch, u);
525 	else
526 		*rvp = u;
527 }
528 
529 #define todigit(x) ((x) - '0')
530 #define ATOI2(x) (todigit((x)[0]) * 10 + todigit((x)[1]))
531 #define ISDIG2(x) (isdigit((unsigned char)(x)[0]) && isdigit((unsigned char)(x)[1]))
532 
533 static void
534 getmmdd(struct tm *ptm, char *ds)
535 {
536 	bool ok = false;
537 	struct tm ttm;
538 
539 	ttm = *ptm;
540 	ttm.tm_isdst = -1;
541 
542 	if (ISDIG2(ds)) {
543 		ttm.tm_mon = ATOI2(ds) - 1;
544 		ds += 2;
545 	}
546 	if (ISDIG2(ds)) {
547 		ttm.tm_mday = ATOI2(ds);
548 		ds += 2;
549 		ok = true;
550 	}
551 	if (ok) {
552 		if (ISDIG2(ds) && ISDIG2(ds + 2)) {
553 			ttm.tm_year = ATOI2(ds) * 100 - TM_YEAR_BASE;
554 			ds += 2;
555 			ttm.tm_year += ATOI2(ds);
556 		} else if (ISDIG2(ds)) {
557 			ttm.tm_year = ATOI2(ds);
558 			if (ttm.tm_year < 69)
559 				ttm.tm_year += 2000 - TM_YEAR_BASE;
560 			else
561 				ttm.tm_year += 1900 - TM_YEAR_BASE;
562 		}
563 	}
564 	if (ok && mktime(&ttm) == -1)
565 		ok = false;
566 
567 	if (ok)
568 		*ptm = ttm;
569 	else {
570 		warnx("Can't convert `%s' to date, ignored.", ds);
571 		usage();
572 	}
573 }
574 
575 __dead
576 static void
577 usage(void)
578 {
579 	(void)fprintf(stderr, "usage: %s [-ax] [-d MMDD[[YY]YY]"
580 	    " [-f fname] [-l days] [-w days]\n", getprogname());
581 	exit(1);
582 }
583