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 1.5 2005/12/26 20:18:56 dillon 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(int sig)
  70 {
  71         if (editpid != -1) {
  72                 kill(editpid, sig);
  73         }
  74 }
  75
  76 void
  77 pw_init(void)
  78 {
  79         struct rlimit rlim;
  80
  81         /* Unlimited resource limits. */
  82         rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY;
  83         setrlimit(RLIMIT_CPU, &rlim);
  84         setrlimit(RLIMIT_FSIZE, &rlim);
  85         setrlimit(RLIMIT_STACK, &rlim);
  86         setrlimit(RLIMIT_DATA, &rlim);
  87         setrlimit(RLIMIT_RSS, &rlim);
  88
  89         /* Don't drop core (not really necessary, but GP's). */
  90         rlim.rlim_cur = rlim.rlim_max = 0;
  91         setrlimit(RLIMIT_CORE, &rlim);
  92
  93         /* Turn off signals. */
  94         signal(SIGALRM, SIG_IGN);
  95         signal(SIGHUP, SIG_IGN);
  96         signal(SIGINT, SIG_IGN);
  97         signal(SIGPIPE, SIG_IGN);
  98         signal(SIGQUIT, SIG_IGN);
  99         signal(SIGTERM, SIG_IGN);
 100         signal(SIGCONT, pw_cont);
 101
 102         /* Create with exact permissions. */
 103         umask(0);
 104 }
 105
 106 int
 107 pw_lock(void)
 108 {
 109         /*
 110          * If the master password file doesn't exist, the system is hosed.
 111          * Might as well try to build one.  Set the close-on-exec bit so
 112          * that users can't get at the encrypted passwords while editing.
 113          * Open should allow flock'ing the file; see 4.4BSD.    XXX
 114          */
 115         for (;;) {
 116                 struct stat st;
 117
 118                 lockfd = open(masterpasswd, O_RDONLY, 0);
 119                 if (lockfd < 0 || fcntl(lockfd, F_SETFD, 1) == -1)
 120                         err(1, "%s", masterpasswd);
 121                 if (flock(lockfd, LOCK_EX|LOCK_NB))
 122                         errx(1, "the password db file is busy");
 123
 124                 /*
 125                  * If the password file was replaced while we were trying to
 126                  * get the lock, our hardlink count will be 0 and we have to
 127                  * close and retry.
 128                  */
 129                 if (fstat(lockfd, &st) < 0)
 130                         errx(1, "fstat() failed");
 131                 if (st.st_nlink != 0)
 132                         break;
 133                 close(lockfd);
 134                 lockfd = -1;
 135         }
 136         return (lockfd);
 137 }
 138
 139 int
 140 pw_tmp(void)
 141 {
 142         static char path[MAXPATHLEN];
 143         int fd;
 144         char *p;
 145
 146         if ((p = strrchr(masterpasswd, '/')) == NULL)
 147                 strcpy(path, "pw.XXXXXX");
 148         else
 149                 if (snprintf(path, sizeof path, "%.*s/pw.XXXXXX",
 150                     (int)(p - masterpasswd), masterpasswd) >= sizeof path)
 151                         errx(1, "%s: path too long", masterpasswd);
 152         if ((fd = mkstemp(path)) == -1)
 153                 err(1, "%s", path);
 154         tempname = path;
 155         return (fd);
 156 }
 157
 158 int
 159 pw_mkdb(char *username)
 160 {
 161         int pstat;
 162         pid_t pid;
 163
 164         fflush(stderr);
 165         if (!(pid = fork())) {
 166                 if(!username) {
 167                         warnx("rebuilding the database...");
 168                         execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p", "-d", mppath,
 169                             tempname, NULL);
 170                 } else {
 171                         warnx("updating the database...");
 172                         execl(_PATH_PWD_MKDB, "pwd_mkdb", "-p", "-d", mppath,
 173                             "-u", username, tempname, NULL);
 174                 }
 175                 pw_error(_PATH_PWD_MKDB, 1, 1);
 176         }
 177         pid = waitpid(pid, &pstat, 0);
 178         if (pid == -1 || !WIFEXITED(pstat) || WEXITSTATUS(pstat) != 0)
 179                 return (0);
 180         warnx("done");
 181         return (1);
 182 }
 183
 184 void
 185 pw_edit(int notsetuid)
 186 {
 187         int pstat;
 188         char *p, *editor;
 189
 190         if (!(editor = getenv("EDITOR")))
 191                 editor = _PATH_VI;
 192         if ((p = strrchr(editor, '/')))
 193                 ++p;
 194         else
 195                 p = editor;
 196
 197         if (!(editpid = fork())) {
 198                 if (notsetuid) {
 199                         setgid(getgid());
 200                         setuid(getuid());
 201                 }
 202                 errno = 0;
 203                 execlp(editor, p, tempname, NULL);
 204                 _exit(errno);
 205         }
 206         for (;;) {
 207                 editpid = waitpid(editpid, (int *)&pstat, 0);
 208                 errno = WEXITSTATUS(pstat);
 209                 if (editpid == -1)
 210                         pw_error(editor, 1, 1);
 211                 else if (WIFSTOPPED(pstat))
 212                         ; /*raise(WSTOPSIG(pstat));*/
 213                 else if (WIFEXITED(pstat) && errno == 0)
 214                         break;
 215                 else
 216                         pw_error(editor, 1, 1);
 217         }
 218         editpid = -1;
 219 }
 220
 221 void
 222 pw_prompt(void)
 223 {
 224         int c, first;
 225
 226         printf("re-edit the password file? [y]: ");
 227         fflush(stdout);
 228         first = c = getchar();
 229         while (c != '\n' && c != EOF)
 230                 c = getchar();
 231         if (first == 'n')
 232                 pw_error(NULL, 0, 0);
 233 }
 234
 235 void
 236 pw_error(char *name, int err, int eval)
 237 {
 238 #ifdef YP
 239         extern int _use_yp;
 240 #endif /* YP */
 241         if (err) {
 242                 if (name != NULL)
 243                         warn("%s", name);
 244                 else
 245                         warn(NULL);
 246         }
 247 #ifdef YP
 248         if (_use_yp)
 249                 warnx("NIS information unchanged");
 250         else
 251 #endif /* YP */
 252         warnx("%s: unchanged", masterpasswd);
 253         unlink(tempname);
 254         exit(eval);
 255 }