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