usr.sbin/vipw/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  * @(#)pw_util.c        8.3 (Berkeley) 4/2/94
  34  * $FreeBSD: src/usr.sbin/vipw/pw_util.c,v 1.17.2.4 2002/09/04 15:28:10 des Exp $
  35  * $DragonFly: src/usr.sbin/vipw/pw_util.c,v 1.3 2004/12/18 22:48:14 swildner Exp $
  36  */
  37
  38 /*
  39  * This file is used by all the "password" programs; vipw(8), chpass(1),
  40  * and passwd(1).
  41  */
  42
  43 #include <sys/param.h>
  44 #include <sys/errno.h>
  45 #include <sys/time.h>
  46 #include <sys/resource.h>
  47 #include <sys/stat.h>
  48 #include <sys/wait.h>
  49
  50 #include <err.h>
  51 #include <fcntl.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
  60 #include "pw_util.h"
  61
  62 extern char *tempname;
  63 static pid_t editpid = -1;
  64 static int lockfd;
  65 char *mppath = _PATH_PWD;
  66 char *masterpasswd = _PATH_MASTERPASSWD;
  67
  68 void
  69 pw_cont(sig)
  70         int sig;
  71 {
  72
  73         if (editpid != -1)
  74                 kill(editpid, sig);
  75 }
  76
  77 void
  78 pw_init()
  79 {
  80         struct rlimit rlim;
  81
  82         /* Unlimited resource limits. */
  83         rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY;
  84         setrlimit(RLIMIT_CPU, &rlim);
  85         setrlimit(RLIMIT_FSIZE, &rlim);
  86         setrlimit(RLIMIT_STACK, &rlim);
  87         setrlimit(RLIMIT_DATA, &rlim);
  88         setrlimit(RLIMIT_RSS, &rlim);
  89
  90         /* Don't drop core (not really necessary, but GP's). */
  91         rlim.rlim_cur = rlim.rlim_max = 0;
  92         setrlimit(RLIMIT_CORE, &rlim);
  93
  94         /* Turn off signals. */
  95         signal(SIGALRM, SIG_IGN);
  96         signal(SIGHUP, SIG_IGN);
  97         signal(SIGINT, SIG_IGN);
  98         signal(SIGPIPE, SIG_IGN);
  99         signal(SIGQUIT, SIG_IGN);
 100         signal(SIGTERM, SIG_IGN);
 101         signal(SIGCONT, pw_cont);
 102
 103         /* Create with exact permissions. */
 104         umask(0);
 105 }
 106
 107 int
 108 pw_lock()
 109 {
 110         /*
 111          * If the master password file doesn't exist, the system is hosed.
 112          * Might as well try to build one.  Set the close-on-exec bit so
 113          * that users can't get at the encrypted passwords while editing.
 114          * Open should allow flock'ing the file; see 4.4BSD.    XXX
 115          */
 116         for (;;) {
 117                 struct stat st;
 118
 119                 lockfd = open(masterpasswd, O_RDONLY, 0);
 120                 if (lockfd < 0 || fcntl(lockfd, F_SETFD, 1) == -1)
 121                         err(1, "%s", masterpasswd);
 122                 if (flock(lockfd, LOCK_EX|LOCK_NB))
 123                         errx(1, "the password db file is busy");
 124
 125                 /*
 126                  * If the password file was replaced while we were trying to
 127                  * get the lock, our hardlink count will be 0 and we have to
 128                  * close and retry.
 129                  */
 130                 if (fstat(lockfd, &st) < 0)
 131                         errx(1, "fstat() failed");
 132                 if (st.st_nlink != 0)
 133                         break;
 134                 close(lockfd);
 135                 lockfd = -1;
 136         }
 137         return (lockfd);
 138 }
 139
 140 int
 141 pw_tmp()
 142 {
 143         static char path[MAXPATHLEN];
 144         int fd;
 145         char *p;
 146
 147         if ((p = strrchr(masterpasswd, '/')) == NULL)
 148                 strcpy(path, "pw.XXXXXX");
 149         else
 150                 if (snprintf(path, sizeof path, "%.*s/pw.XXXXXX",
 151                     (int)(p - masterpasswd), masterpasswd) >= sizeof path)
 152                         errx(1, "%s: path too long", masterpasswd);
 153         if ((fd = mkstemp(path)) == -1)
 154                 err(1, "%s", path);
 155         tempname = path;
 156         return (fd);
 157 }
 158
 159 int
 160 pw_mkdb(username)
 161 char *username;
 162 {
 163         int pstat;
 164         pid_t pid;
 165
 166         fflush(stderr);
 167         if (!(pid = fork())) {
 168                 if(!username) {
 169                         warnx("rebuilding the database...");
 170                         execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p", "-d", mppath,
 171                             tempname, NULL);
 172                 } else {
 173                         warnx("updating the database...");
 174                         execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p", "-d", mppath,
 175                             "-u", 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                         setgid(getgid());
 203                         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         printf("re-edit the password file? [y]: ");
 230         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                 if (name != NULL)
 248                         warn("%s", name);
 249                 else
 250                         warn(NULL);
 251         }
 252 #ifdef YP
 253         if (_use_yp)
 254                 warnx("NIS information unchanged");
 255         else
 256 #endif /* YP */
 257         warnx("%s: unchanged", masterpasswd);
 258         unlink(tempname);
 259         exit(eval);
 260 }