passwd.c revision 1.15 1 /* $NetBSD: passwd.c,v 1.15 1998/12/09 14:35:03 christos Exp $ */
2
3 /*
4 * Copyright (c) 1987, 1993, 1994, 1995
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. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by the University of
18 * California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include <sys/cdefs.h>
37 #if defined(LIBC_SCCS) && !defined(lint)
38 __RCSID("$NetBSD: passwd.c,v 1.15 1998/12/09 14:35:03 christos Exp $");
39 #endif /* LIBC_SCCS and not lint */
40
41 #include <sys/types.h>
42 #include <sys/stat.h>
43 #include <sys/time.h>
44 #include <sys/resource.h>
45 #include <sys/wait.h>
46
47 #include <ctype.h>
48 #include <err.h>
49 #include <errno.h>
50 #include <fcntl.h>
51 #include <limits.h>
52 #include <paths.h>
53 #include <pwd.h>
54 #include <signal.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #include <unistd.h>
59 #include <util.h>
60
61 static void pw_cont __P((int sig));
62 static int pw_equal __P((char *buf, struct passwd *old_pw));
63
64 int
65 pw_lock(retries)
66 int retries;
67 {
68 int i, fd;
69 mode_t old_mode;
70 int oerrno;
71
72 /* Acquire the lock file. */
73 old_mode = umask(0);
74 fd = open(_PATH_MASTERPASSWD_LOCK, O_WRONLY|O_CREAT|O_EXCL, 0600);
75 for (i = 0; i < retries && fd < 0 && errno == EEXIST; i++) {
76 sleep(1);
77 fd = open(_PATH_MASTERPASSWD_LOCK, O_WRONLY|O_CREAT|O_EXCL,
78 0600);
79 }
80 oerrno = errno;
81 (void)umask(old_mode);
82 errno = oerrno;
83 return(fd);
84 }
85
86 int
87 pw_mkdb()
88 {
89 int pstat;
90 pid_t pid;
91
92 pid = vfork();
93 if (pid == 0) {
94 execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p",
95 _PATH_MASTERPASSWD_LOCK, NULL);
96 _exit(1);
97 }
98 pid = waitpid(pid, &pstat, 0);
99 if (pid == -1 || !WIFEXITED(pstat) || WEXITSTATUS(pstat) != 0)
100 return(-1);
101 return(0);
102 }
103
104 int
105 pw_abort()
106 {
107 return(unlink(_PATH_MASTERPASSWD_LOCK));
108 }
109
110 /* Everything below this point is intended for the convenience of programs
111 * which allow a user to interactively edit the passwd file. Errors in the
112 * routines below will cause the process to abort. */
113
114 static pid_t editpid = -1;
115
116 static void
117 pw_cont(sig)
118 int sig;
119 {
120
121 if (editpid != -1)
122 kill(editpid, sig);
123 }
124
125 void
126 pw_init()
127 {
128 struct rlimit rlim;
129
130 /* Unlimited resource limits. */
131 rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY;
132 (void)setrlimit(RLIMIT_CPU, &rlim);
133 (void)setrlimit(RLIMIT_FSIZE, &rlim);
134 (void)setrlimit(RLIMIT_STACK, &rlim);
135 (void)setrlimit(RLIMIT_DATA, &rlim);
136 (void)setrlimit(RLIMIT_RSS, &rlim);
137
138 /* Don't drop core (not really necessary, but GP's). */
139 rlim.rlim_cur = rlim.rlim_max = 0;
140 (void)setrlimit(RLIMIT_CORE, &rlim);
141
142 /* Turn off signals. */
143 (void)signal(SIGALRM, SIG_IGN);
144 (void)signal(SIGHUP, SIG_IGN);
145 (void)signal(SIGINT, SIG_IGN);
146 (void)signal(SIGPIPE, SIG_IGN);
147 (void)signal(SIGQUIT, SIG_IGN);
148 (void)signal(SIGTERM, SIG_IGN);
149 (void)signal(SIGCONT, pw_cont);
150 }
151
152 void
153 pw_edit(notsetuid, filename)
154 int notsetuid;
155 const char *filename;
156 {
157 int i, xargc, pstat;
158 char *p, *editor;
159 char **xargv;
160 #ifdef __GNUC__
161 (void) &editor;
162 #endif
163
164 if (filename == NULL)
165 filename = _PATH_MASTERPASSWD_LOCK;
166 if ((editor = getenv("EDITOR")) == NULL)
167 editor = strdup(_PATH_VI);
168 else
169 editor = strdup(editor);
170 if ((p = strrchr(editor, '/')) != NULL)
171 ++p;
172 else
173 p = editor;
174
175 /* Scan editor string, count spaces, allocate arg vector. */
176 for (i = 0, xargc = 0; p[i] != '\0'; i++) {
177 if (isspace(p[i])) {
178 while (isspace(p[i++]))
179 /* skip white space */ ;
180 if (p[i] == '\0')
181 break;
182 xargc++;
183 }
184 }
185
186 /* argv[0] + <xargc args> + filename + NULL */
187 xargv = (char **)malloc(sizeof(char *) * (xargc + 3));
188 if (xargv == NULL)
189 pw_error("malloc failed", 1, 1);
190
191 i = 0;
192 xargv[i++] = p;
193 for (; *p != '\0'; p++) {
194 if (isspace(*p)) {
195 while(isspace(*p))
196 *p++ = '\0'; /* blast whitespace */
197 if (*p == '\0')
198 break;
199 xargv[i++] = p;
200 }
201 }
202
203 /*LINTED*/
204 xargv[i++] = (char *)filename;
205 xargv[i] = NULL;
206
207 if (!(editpid = vfork())) {
208 if (notsetuid) {
209 setgid(getgid());
210 setuid(getuid());
211 }
212 execvp(editor, xargv);
213 _exit(1);
214 }
215 for (;;) {
216 editpid = waitpid(editpid, (int *)&pstat, WUNTRACED);
217 if (editpid == -1)
218 pw_error(editor, 1, 1);
219 else if (WIFSTOPPED(pstat))
220 raise(WSTOPSIG(pstat));
221 else if (WIFEXITED(pstat) && WEXITSTATUS(pstat) == 0)
222 break;
223 else
224 pw_error(editor, 1, 1);
225 }
226 editpid = -1;
227 free(editor);
228 free(xargv);
229 }
230
231 void
232 pw_prompt()
233 {
234 int c;
235
236 (void)printf("re-edit the password file? [y]: ");
237 (void)fflush(stdout);
238 c = getchar();
239 if (c != EOF && c != '\n')
240 while (getchar() != '\n');
241 if (c == 'n')
242 pw_error(NULL, 0, 0);
243 }
244
245 /* for use in pw_copy(). Compare a pw entry to a pw struct. */
246 static int
247 pw_equal (buf, pw)
248 char *buf;
249 struct passwd *pw;
250 {
251 struct passwd buf_pw;
252 int len = strlen (buf);
253 if (buf[len-1] == '\n')
254 buf[len-1] = '\0';
255 if (!pw_scan(buf, &buf_pw, NULL))
256 return 0;
257 return !strcmp(pw->pw_name, buf_pw.pw_name)
258 && pw->pw_uid == buf_pw.pw_uid
259 && pw->pw_gid == buf_pw.pw_gid
260 && !strcmp(pw->pw_class, buf_pw.pw_class)
261 && (long)pw->pw_change == (long)buf_pw.pw_change
262 && (long)pw->pw_expire == (long)buf_pw.pw_expire
263 && !strcmp(pw->pw_gecos, buf_pw.pw_gecos)
264 && !strcmp(pw->pw_dir, buf_pw.pw_dir)
265 && !strcmp(pw->pw_shell, buf_pw.pw_shell);
266 }
267
268 void
269 pw_copy(ffd, tfd, pw, old_pw)
270 int ffd, tfd;
271 struct passwd *pw, *old_pw;
272 {
273 FILE *from, *to;
274 int done;
275 char *p, buf[8192];
276
277 if (!(from = fdopen(ffd, "r")))
278 pw_error(_PATH_MASTERPASSWD, 1, 1);
279 if (!(to = fdopen(tfd, "w")))
280 pw_error(_PATH_MASTERPASSWD_LOCK, 1, 1);
281
282 for (done = 0; fgets(buf, sizeof(buf), from);) {
283 if (!strchr(buf, '\n')) {
284 warnx("%s: line too long", _PATH_MASTERPASSWD);
285 pw_error(NULL, 0, 1);
286 }
287 if (done) {
288 (void)fprintf(to, "%s", buf);
289 if (ferror(to))
290 goto err;
291 continue;
292 }
293 if (!(p = strchr(buf, ':'))) {
294 warnx("%s: corrupted entry", _PATH_MASTERPASSWD);
295 pw_error(NULL, 0, 1);
296 }
297 *p = '\0';
298 if (strcmp(buf, pw->pw_name)) {
299 *p = ':';
300 (void)fprintf(to, "%s", buf);
301 if (ferror(to))
302 goto err;
303 continue;
304 }
305 *p = ':';
306 if (old_pw && !pw_equal(buf, old_pw)) {
307 warnx("%s: entry inconsistent",
308 _PATH_MASTERPASSWD);
309 pw_error(NULL, 0, 1);
310 }
311 (void)fprintf(to, "%s:%s:%d:%d:%s:%ld:%ld:%s:%s:%s\n",
312 pw->pw_name, pw->pw_passwd, pw->pw_uid, pw->pw_gid,
313 pw->pw_class, (long)pw->pw_change, (long)pw->pw_expire,
314 pw->pw_gecos, pw->pw_dir, pw->pw_shell);
315 done = 1;
316 if (ferror(to))
317 goto err;
318 }
319 /* Only append a new entry if real uid is root! */
320 if (!done) {
321 if (getuid() == 0)
322 (void)fprintf(to, "%s:%s:%d:%d:%s:%ld:%ld:%s:%s:%s\n",
323 pw->pw_name, pw->pw_passwd, pw->pw_uid, pw->pw_gid,
324 pw->pw_class, (long)pw->pw_change,
325 (long)pw->pw_expire, pw->pw_gecos, pw->pw_dir,
326 pw->pw_shell);
327 else
328 warnx("%s: changes not made, no such entry",
329 _PATH_MASTERPASSWD);
330 }
331
332 if (ferror(to))
333 err: pw_error(NULL, 1, 1);
334 (void)fclose(to);
335 }
336
337 void
338 pw_error(name, err, eval)
339 const char *name;
340 int err, eval;
341 {
342 if (err)
343 warn(name);
344
345 warnx("%s: unchanged", _PATH_MASTERPASSWD);
346 pw_abort();
347 exit(eval);
348 }
349