xref: /freebsd/lib/libutil/pw_util.c (revision 2ad872c5794e4c26fdf6ed219ad3f09ca0d5304a)
1 /*-
2  * Copyright (c) 1990, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 #if 0
36 static const char sccsid[] = "@(#)pw_util.c	8.3 (Berkeley) 4/2/94";
37 #endif
38 static const char rcsid[] =
39 	"$Id: pw_util.c,v 1.12 1998/12/13 01:36:45 dillon Exp $";
40 #endif /* not lint */
41 
42 /*
43  * This file is used by all the "password" programs; vipw(8), chpass(1),
44  * and passwd(1).
45  */
46 
47 #include <sys/param.h>
48 #include <sys/errno.h>
49 #include <sys/time.h>
50 #include <sys/resource.h>
51 #include <sys/stat.h>
52 #include <sys/wait.h>
53 
54 #include <err.h>
55 #include <fcntl.h>
56 #include <paths.h>
57 #include <pwd.h>
58 #include <signal.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62 #include <unistd.h>
63 
64 #include "pw_util.h"
65 
66 extern char *tempname;
67 static pid_t editpid = -1;
68 static int lockfd;
69 
70 void
71 pw_cont(sig)
72 	int sig;
73 {
74 
75 	if (editpid != -1)
76 		kill(editpid, sig);
77 }
78 
79 void
80 pw_init()
81 {
82 	struct rlimit rlim;
83 
84 	/* Unlimited resource limits. */
85 	rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY;
86 	(void)setrlimit(RLIMIT_CPU, &rlim);
87 	(void)setrlimit(RLIMIT_FSIZE, &rlim);
88 	(void)setrlimit(RLIMIT_STACK, &rlim);
89 	(void)setrlimit(RLIMIT_DATA, &rlim);
90 	(void)setrlimit(RLIMIT_RSS, &rlim);
91 
92 	/* Don't drop core (not really necessary, but GP's). */
93 	rlim.rlim_cur = rlim.rlim_max = 0;
94 	(void)setrlimit(RLIMIT_CORE, &rlim);
95 
96 	/* Turn off signals. */
97 	(void)signal(SIGALRM, SIG_IGN);
98 	(void)signal(SIGHUP, SIG_IGN);
99 	(void)signal(SIGINT, SIG_IGN);
100 	(void)signal(SIGPIPE, SIG_IGN);
101 	(void)signal(SIGQUIT, SIG_IGN);
102 	(void)signal(SIGTERM, SIG_IGN);
103 	(void)signal(SIGCONT, pw_cont);
104 
105 	/* Create with exact permissions. */
106 	(void)umask(0);
107 }
108 
109 int
110 pw_lock()
111 {
112 	/*
113 	 * If the master password file doesn't exist, the system is hosed.
114 	 * Might as well try to build one.  Set the close-on-exec bit so
115 	 * that users can't get at the encrypted passwords while editing.
116 	 * Open should allow flock'ing the file; see 4.4BSD.	XXX
117 	 */
118 	for (;;) {
119 		struct stat st;
120 
121 		lockfd = open(_PATH_MASTERPASSWD, O_RDONLY, 0);
122 		if (lockfd < 0 || fcntl(lockfd, F_SETFD, 1) == -1)
123 			err(1, "%s", _PATH_MASTERPASSWD);
124 		if (flock(lockfd, LOCK_EX|LOCK_NB))
125 			errx(1, "the password db file is busy");
126 
127 		/*
128 		 * If the password file was replaced while we were trying to
129 		 * get the lock, our hardlink count will be 0 and we have to
130 		 * close and retry.
131 		 */
132 		if (fstat(lockfd, &st) < 0)
133 			errx(1, "fstat() failed");
134 		if (st.st_nlink != 0)
135 			break;
136 		close(lockfd);
137 		lockfd = -1;
138 	}
139 	return (lockfd);
140 }
141 
142 int
143 pw_tmp()
144 {
145 	static char path[MAXPATHLEN] = _PATH_MASTERPASSWD;
146 	int fd;
147 	char *p;
148 
149 	if ((p = strrchr(path, '/')))
150 		++p;
151 	else
152 		p = path;
153 	strcpy(p, "pw.XXXXXX");
154 	if ((fd = mkstemp(path)) == -1)
155 		err(1, "%s", path);
156 	tempname = path;
157 	return (fd);
158 }
159 
160 int
161 pw_mkdb(username)
162 char *username;
163 {
164 	int pstat;
165 	pid_t pid;
166 
167 	(void)fflush(stderr);
168 	if (!(pid = fork())) {
169 		if(!username) {
170 			warnx("rebuilding the database...");
171 			execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p", tempname, NULL);
172 		} else {
173 			warnx("updating the database...");
174 			execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p", "-u",
175 					username, tempname, NULL);
176 		}
177 		pw_error(_PATH_PWD_MKDB, 1, 1);
178 	}
179 	pid = waitpid(pid, &pstat, 0);
180 	if (pid == -1 || !WIFEXITED(pstat) || WEXITSTATUS(pstat) != 0)
181 		return (0);
182 	warnx("done");
183 	return (1);
184 }
185 
186 void
187 pw_edit(notsetuid)
188 	int notsetuid;
189 {
190 	int pstat;
191 	char *p, *editor;
192 
193 	if (!(editor = getenv("EDITOR")))
194 		editor = _PATH_VI;
195 	if ((p = strrchr(editor, '/')))
196 		++p;
197 	else
198 		p = editor;
199 
200 	if (!(editpid = fork())) {
201 		if (notsetuid) {
202 			(void)setgid(getgid());
203 			(void)setuid(getuid());
204 		}
205 		errno = 0;
206 		execlp(editor, p, tempname, NULL);
207 		_exit(errno);
208 	}
209 	for (;;) {
210 		editpid = waitpid(editpid, (int *)&pstat, WUNTRACED);
211 		errno = WEXITSTATUS(pstat);
212 		if (editpid == -1)
213 			pw_error(editor, 1, 1);
214 		else if (WIFSTOPPED(pstat))
215 			raise(WSTOPSIG(pstat));
216 		else if (WIFEXITED(pstat) && errno == 0)
217 			break;
218 		else
219 			pw_error(editor, 1, 1);
220 	}
221 	editpid = -1;
222 }
223 
224 void
225 pw_prompt()
226 {
227 	int c, first;
228 
229 	(void)printf("re-edit the password file? [y]: ");
230 	(void)fflush(stdout);
231 	first = c = getchar();
232 	while (c != '\n' && c != EOF)
233 		c = getchar();
234 	if (first == 'n')
235 		pw_error(NULL, 0, 0);
236 }
237 
238 void
239 pw_error(name, err, eval)
240 	char *name;
241 	int err, eval;
242 {
243 #ifdef YP
244 	extern int _use_yp;
245 #endif /* YP */
246 	if (err)
247 		warn(name);
248 #ifdef YP
249 	if (_use_yp)
250 		warnx("NIS information unchanged");
251 	else
252 #endif /* YP */
253 	warnx("%s: unchanged", _PATH_MASTERPASSWD);
254 	(void)unlink(tempname);
255 	exit(eval);
256 }
257