xref: /openbsd-src/usr.bin/calendar/calendar.c (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1 /*	$OpenBSD: calendar.c,v 1.35 2015/12/07 18:46:35 espie 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/stat.h>
33 #include <sys/types.h>
34 #include <sys/wait.h>
35 #include <err.h>
36 #include <errno.h>
37 #include <locale.h>
38 #include <login_cap.h>
39 #include <pwd.h>
40 #include <signal.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <limits.h>
45 #include <time.h>
46 #include <unistd.h>
47 
48 #include "pathnames.h"
49 #include "calendar.h"
50 
51 char *calendarFile = "calendar";  /* default calendar file */
52 char *calendarHome = ".calendar"; /* HOME */
53 char *calendarNoMail = "nomail";  /* don't sent mail if this file exists */
54 
55 struct passwd *pw;
56 int doall = 0;
57 int daynames = 0;
58 time_t f_time = 0;
59 int bodun_always = 0;
60 
61 int f_dayAfter = 0; /* days after current date */
62 int f_dayBefore = 0; /* days before current date */
63 int f_SetdayAfter = 0; /* calendar invoked with -A */
64 
65 struct specialev spev[NUMEV];
66 
67 void childsig(int);
68 
69 int
70 main(int argc, char *argv[])
71 {
72 	int ch;
73 	const char *errstr;
74 	char *caldir;
75 
76 	(void)setlocale(LC_ALL, "");
77 
78 	while ((ch = getopt(argc, argv, "abwf:t:A:B:-")) != -1)
79 		switch (ch) {
80 		case '-':		/* backward contemptible */
81 		case 'a':
82 			if (getuid())
83 				errx(1, "%s", strerror(EPERM));
84 			doall = 1;
85 			break;
86 
87 		case 'b':
88 			bodun_always = 1;
89 			break;
90 
91 		case 'f': /* other calendar file */
92 		        calendarFile = optarg;
93 			break;
94 
95 		case 't': /* other date, undocumented, for tests */
96 			if ((f_time = Mktime(optarg)) <= 0)
97 				errx(1, "specified date is outside allowed range");
98 			break;
99 
100 		case 'A': /* days after current date */
101 			f_dayAfter = strtonum(optarg, 0, INT_MAX, &errstr);
102 			if (errstr)
103 				errx(1, "-A %s: %s", optarg, errstr);
104 			f_SetdayAfter = 1;
105 			break;
106 
107 		case 'B': /* days before current date */
108 			f_dayBefore = strtonum(optarg, 0, INT_MAX, &errstr);
109 			if (errstr)
110 				errx(1, "-B %s: %s", optarg, errstr);
111 			break;
112 
113 		case 'w':
114 			daynames = 1;
115 			break;
116 
117 		default:
118 			usage();
119 		}
120 	argc -= optind;
121 	argv += optind;
122 
123 	if (argc)
124 		usage();
125 
126 	if (doall) {
127 		if (pledge("stdio rpath tmppath fattr getpw id proc exec", NULL)
128 		    == -1)
129 			err(1, "pledge");
130 	} else {
131 		if (pledge("stdio rpath proc exec", NULL) == -1)
132 			err(1, "pledge");
133 	}
134 
135 	/* use current time */
136 	if (f_time <= 0)
137 	    (void)time(&f_time);
138 
139 	if (f_dayBefore) {
140 		/* Move back in time and only look forwards */
141 		f_dayAfter += f_dayBefore;
142 		f_time -= SECSPERDAY * f_dayBefore;
143 		f_dayBefore = 0;
144 	}
145 	settime(&f_time);
146 
147 	if (doall) {
148 		pid_t kid, deadkid;
149 		int kidstat, kidreaped, runningkids;
150 		int acstat;
151 		struct stat sbuf;
152 		time_t t;
153 		unsigned int sleeptime;
154 
155 		signal(SIGCHLD, childsig);
156 		runningkids = 0;
157 		t = time(NULL);
158 		while ((pw = getpwent()) != NULL) {
159 			acstat = 0;
160 			/* Avoid unnecessary forks.  The calendar file is only
161 			 * opened as the user later; if it can't be opened,
162 			 * it's no big deal.  Also, get to correct directory.
163 			 * Note that in an NFS environment root may get EACCES
164 			 * on a chdir(), in which case we have to fork.  As long as
165 			 * we can chdir() we can stat(), unless the user is
166 			 * modifying permissions while this is running.
167 			 */
168 			if (chdir(pw->pw_dir)) {
169 				if (errno == EACCES)
170 					acstat = 1;
171 				else
172 					continue;
173 			}
174 			if (stat(calendarFile, &sbuf) != 0) {
175 				if (chdir(calendarHome)) {
176 					if (errno == EACCES)
177 						acstat = 1;
178 					else
179 						continue;
180 				}
181 				if (stat(calendarNoMail, &sbuf) == 0 ||
182 				    stat(calendarFile, &sbuf) != 0)
183 					continue;
184 			}
185 			sleeptime = USERTIMEOUT;
186 			switch ((kid = fork())) {
187 			case -1:	/* error */
188 				warn("fork");
189 				continue;
190 			case 0:	/* child */
191 				(void)setpgid(getpid(), getpid());
192 				(void)setlocale(LC_ALL, "");
193 				if (setusercontext(NULL, pw, pw->pw_uid,
194 				    LOGIN_SETALL ^ LOGIN_SETLOGIN))
195 					err(1, "unable to set user context (uid %u)",
196 					    pw->pw_uid);
197 				if (acstat) {
198 					if (chdir(pw->pw_dir) ||
199 					    stat(calendarFile, &sbuf) != 0 ||
200 					    chdir(calendarHome) ||
201 					    stat(calendarNoMail, &sbuf) == 0 ||
202 					    stat(calendarFile, &sbuf) != 0)
203 						exit(0);
204 				}
205 				cal();
206 				exit(0);
207 			}
208 			/* parent: wait a reasonable time, then kill child if
209 			 * necessary.
210 			 */
211 			runningkids++;
212 			kidreaped = 0;
213 			do {
214 				sleeptime = sleep(sleeptime);
215 				/* Note that there is the possibility, if the sleep
216 				 * stops early due to some other signal, of the child
217 				 * terminating and not getting detected during the next
218 				 * sleep.  In that unlikely worst case, we just sleep
219 				 * too long for that user.
220 				 */
221 				for (;;) {
222 					deadkid = waitpid(-1, &kidstat, WNOHANG);
223 					if (deadkid <= 0)
224 						break;
225 					runningkids--;
226 					if (deadkid == kid) {
227 						kidreaped = 1;
228 						sleeptime = 0;
229 					}
230 				}
231 			} while (sleeptime);
232 
233 			if (!kidreaped) {
234 				/* It doesn't _really_ matter if the kill fails, e.g.
235 				 * if there's only a zombie now.
236 				 */
237 				if (getpgid(kid) != getpgrp())
238 					(void)killpg(getpgid(kid), SIGTERM);
239 				else
240 					(void)kill(kid, SIGTERM);
241 				warnx("uid %u did not finish in time", pw->pw_uid);
242 			}
243 			if (time(NULL) - t >= SECSPERDAY)
244 				errx(2, "'calendar -a' took more than a day; "
245 				    "stopped at uid %u",
246 				    pw->pw_uid);
247 		}
248 		for (;;) {
249 			deadkid = waitpid(-1, &kidstat, WNOHANG);
250 			if (deadkid <= 0)
251 				break;
252 			runningkids--;
253 		}
254 		if (runningkids)
255 			warnx("%d child processes still running when "
256 			    "'calendar -a' finished", runningkids);
257 	} else if ((caldir = getenv("CALENDAR_DIR")) != NULL) {
258 		if(!chdir(caldir))
259 			cal();
260 	} else
261 		cal();
262 
263 	exit(0);
264 }
265 
266 
267 void
268 usage(void)
269 {
270 	(void)fprintf(stderr,
271 	    "usage: calendar [-abw] [-A num] [-B num] [-f calendarfile] "
272 	    "[-t [[[cc]yy]mm]dd]\n");
273 	exit(1);
274 }
275 
276 
277 void
278 childsig(int signo)
279 {
280 }
281