libutil/pw_util.c

   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   "$FreeBSD$";
  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 static char _default_editor[] = _PATH_VI;
  70 char mppath[] = _PATH_PWD;
  71 char masterpasswd[] = _PATH_MASTERPASSWD;
  72
  73 void             pw_cont(int);
  74
  75 void
  76 pw_cont(int sig)
  77 {
  78
  79         if (editpid != -1)
  80                 kill(editpid, sig);
  81 }
  82
  83 void
  84 pw_init(void)
  85 {
  86         struct rlimit rlim;
  87
  88         /* Unlimited resource limits. */
  89         rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY;
  90         (void)setrlimit(RLIMIT_CPU, &rlim);
  91         (void)setrlimit(RLIMIT_FSIZE, &rlim);
  92         (void)setrlimit(RLIMIT_STACK, &rlim);
  93         (void)setrlimit(RLIMIT_DATA, &rlim);
  94         (void)setrlimit(RLIMIT_RSS, &rlim);
  95
  96         /* Don't drop core (not really necessary, but GP's). */
  97         rlim.rlim_cur = rlim.rlim_max = 0;
  98         (void)setrlimit(RLIMIT_CORE, &rlim);
  99
 100         /* Turn off signals. */
 101         (void)signal(SIGALRM, SIG_IGN);
 102         (void)signal(SIGHUP, SIG_IGN);
 103         (void)signal(SIGINT, SIG_IGN);
 104         (void)signal(SIGPIPE, SIG_IGN);
 105         (void)signal(SIGQUIT, SIG_IGN);
 106         (void)signal(SIGTERM, SIG_IGN);
 107         (void)signal(SIGCONT, pw_cont);
 108
 109         /* Create with exact permissions. */
 110         (void)umask(0);
 111 }
 112
 113 int
 114 pw_lock(void)
 115 {
 116         /*
 117          * If the master password file doesn't exist, the system is hosed.
 118          * Might as well try to build one.  Set the close-on-exec bit so
 119          * that users can't get at the encrypted passwords while editing.
 120          * Open should allow flock'ing the file; see 4.4BSD.    XXX
 121          */
 122         for (;;) {
 123                 struct stat st;
 124
 125                 lockfd = open(masterpasswd, O_RDONLY, 0);
 126                 if (lockfd < 0 || fcntl(lockfd, F_SETFD, 1) == -1)
 127                         err(1, "%s", masterpasswd);
 128                 if (flock(lockfd, LOCK_EX|LOCK_NB))
 129                         errx(1, "the password db file is busy");
 130
 131                 /*
 132                  * If the password file was replaced while we were trying to
 133                  * get the lock, our hardlink count will be 0 and we have to
 134                  * close and retry.
 135                  */
 136                 if (fstat(lockfd, &st) < 0)
 137                         errx(1, "fstat() failed");
 138                 if (st.st_nlink != 0)
 139                         break;
 140                 close(lockfd);
 141                 lockfd = -1;
 142         }
 143         return (lockfd);
 144 }
 145
 146 int
 147 pw_tmp(void)
 148 {
 149         static char path[MAXPATHLEN];
 150         int fd;
 151         char *p;
 152
 153         strncpy(path, masterpasswd, MAXPATHLEN - 1);
 154         path[MAXPATHLEN] = '\0';
 155
 156         if ((p = strrchr(path, '/')))
 157                 ++p;
 158         else
 159                 p = path;
 160         strcpy(p, "pw.XXXXXX");
 161         if ((fd = mkstemp(path)) == -1)
 162                 err(1, "%s", path);
 163         tempname = path;
 164         return (fd);
 165 }
 166
 167 int
 168 pw_mkdb(const char *username)
 169 {
 170         int pstat;
 171         pid_t pid;
 172
 173         (void)fflush(stderr);
 174         if (!(pid = fork())) {
 175                 if(!username) {
 176                         warnx("rebuilding the database...");
 177                         execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p", "-d", mppath,
 178                             tempname, (char *)NULL);
 179                 } else {
 180                         warnx("updating the database...");
 181                         execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p", "-d", mppath,
 182                             "-u", username, tempname, (char *)NULL);
 183                 }
 184                 pw_error(_PATH_PWD_MKDB, 1, 1);
 185         }
 186         pid = waitpid(pid, &pstat, 0);
 187         if (pid == -1 || !WIFEXITED(pstat) || WEXITSTATUS(pstat) != 0)
 188                 return (0);
 189         warnx("done");
 190         return (1);
 191 }
 192
 193 void
 194 pw_edit(int notsetuid)
 195 {
 196         int pstat;
 197         char *p, *editor;
 198
 199         if (!(editor = getenv("EDITOR")))
 200                 editor = _default_editor;
 201         if ((p = strrchr(editor, '/')))
 202                 ++p;
 203         else
 204                 p = editor;
 205
 206         if (!(editpid = fork())) {
 207                 if (notsetuid) {
 208                         (void)setgid(getgid());
 209                         (void)setuid(getuid());
 210                 }
 211                 errno = 0;
 212                 execlp(editor, p, tempname, (char *)NULL);
 213                 _exit(errno);
 214         }
 215         for (;;) {
 216                 editpid = waitpid(editpid, (int *)&pstat, WUNTRACED);
 217                 errno = WEXITSTATUS(pstat);
 218                 if (editpid == -1)
 219                         pw_error(editor, 1, 1);
 220                 else if (WIFSTOPPED(pstat))
 221                         raise(WSTOPSIG(pstat));
 222                 else if (WIFEXITED(pstat) && errno == 0)
 223                         break;
 224                 else
 225                         pw_error(editor, 1, 1);
 226         }
 227         editpid = -1;
 228 }
 229
 230 void
 231 pw_prompt(void)
 232 {
 233         int c, first;
 234
 235         (void)printf("re-edit the password file? [y]: ");
 236         (void)fflush(stdout);
 237         first = c = getchar();
 238         while (c != '\n' && c != EOF)
 239                 c = getchar();
 240         if (first == 'n')
 241                 pw_error(NULL, 0, 0);
 242 }
 243
 244 void
 245 pw_error(const char *name, int error, int eval)
 246 {
 247 #ifdef YP
 248         extern int _use_yp;
 249 #endif /* YP */
 250         if (error) {
 251                 if (name != NULL)
 252                         warn("%s", name);
 253                 else
 254                         warn(NULL);
 255         }
 256 #ifdef YP
 257         if (_use_yp)
 258                 warnx("NIS information unchanged");
 259         else
 260 #endif /* YP */
 261         warnx("%s: unchanged", masterpasswd);
 262         (void)unlink(tempname);
 263         exit(eval);
 264 }