lib/libutil/pw_scan.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  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * $FreeBSD: src/lib/libc/gen/pw_scan.c,v 1.25 2004/01/18 21:33:25 charnier Exp $
  30  * $DragonFly: src/lib/libutil/pw_scan.c,v 1.3 2007/12/30 13:44:33 matthias Exp $
  31  */
  32
  33 /*
  34  * This module is used to "verify" password entries by chpass(1) and
  35  * pwd_mkdb(8).
  36  */
  37
  38 #include <sys/param.h>
  39
  40 #include <err.h>
  41 #include <errno.h>
  42 #include <fcntl.h>
  43 #include <pwd.h>
  44 #include <stdio.h>
  45 #include <string.h>
  46 #include <stdlib.h>
  47 #include <unistd.h>
  48
  49 #include <libutil.h>
  50
  51 /*
  52  * Some software assumes that IDs are short.  We should emit warnings
  53  * for id's which cannot be stored in a short, but we are more liberal
  54  * by default, warning for IDs greater than USHRT_MAX.
  55  *
  56  * If pw_big_ids_warning is -1 on entry to pw_scan(), it will be set based
  57  * on the existence of PW_SCAN_BIG_IDS in the environment.
  58  */
  59 static int      pw_big_ids_warning = -1;
  60
  61 int
  62 __pw_scan(char *bp, struct passwd *pw, int flags)
  63 {
  64         uid_t id;
  65         int root;
  66         char *ep, *p, *sh;
  67
  68         if (pw_big_ids_warning == -1)
  69                 pw_big_ids_warning = getenv("PW_SCAN_BIG_IDS") == NULL ? 1 : 0;
  70
  71         pw->pw_fields = 0;
  72         if (!(pw->pw_name = strsep(&bp, ":")))          /* login */
  73                 goto fmt;
  74         root = !strcmp(pw->pw_name, "root");
  75         if (pw->pw_name[0] && (pw->pw_name[0] != '+' || pw->pw_name[1] == '\0'))
  76                 pw->pw_fields |= _PWF_NAME;
  77
  78         if (!(pw->pw_passwd = strsep(&bp, ":")))        /* passwd */
  79                 goto fmt;
  80         if (pw->pw_passwd[0])
  81                 pw->pw_fields |= _PWF_PASSWD;
  82
  83         if (!(p = strsep(&bp, ":")))                    /* uid */
  84                 goto fmt;
  85         if (p[0])
  86                 pw->pw_fields |= _PWF_UID;
  87         else {
  88                 if (pw->pw_name[0] != '+' && pw->pw_name[0] != '-') {
  89                         if (flags & _PWSCAN_WARN)
  90                                 warnx("no uid for user %s", pw->pw_name);
  91                         return (0);
  92                 }
  93         }
  94         id = strtoul(p, &ep, 10);
  95         if (errno == ERANGE) {
  96                 if (flags & _PWSCAN_WARN)
  97                         warnx("%s > max uid value (%lu)", p, ULONG_MAX);
  98                 return (0);
  99         }
 100         if (*ep != '\0') {
 101                 if (flags & _PWSCAN_WARN)
 102                         warnx("%s uid is incorrect", p);
 103                 return (0);
 104         }
 105         if (root && id) {
 106                 if (flags & _PWSCAN_WARN)
 107                         warnx("root uid should be 0");
 108                 return (0);
 109         }
 110         if (flags & _PWSCAN_WARN && pw_big_ids_warning && id > USHRT_MAX) {
 111                 warnx("%s > recommended max uid value (%u)", p, USHRT_MAX);
 112                 /*return (0);*/ /* THIS SHOULD NOT BE FATAL! */
 113         }
 114         pw->pw_uid = id;
 115
 116         if (!(p = strsep(&bp, ":")))                    /* gid */
 117                 goto fmt;
 118         if (p[0])
 119                 pw->pw_fields |= _PWF_GID;
 120         else {
 121                 if (pw->pw_name[0] != '+' && pw->pw_name[0] != '-') {
 122                         if (flags & _PWSCAN_WARN)
 123                                 warnx("no gid for user %s", pw->pw_name);
 124                         return (0);
 125                 }
 126         }
 127         id = strtoul(p, &ep, 10);
 128         if (errno == ERANGE) {
 129                 if (flags & _PWSCAN_WARN)
 130                         warnx("%s > max gid value (%lu)", p, ULONG_MAX);
 131                 return (0);
 132         }
 133         if (*ep != '\0') {
 134                 if (flags & _PWSCAN_WARN)
 135                         warnx("%s gid is incorrect", p);
 136                 return (0);
 137         }
 138         if (flags & _PWSCAN_WARN && pw_big_ids_warning && id > USHRT_MAX) {
 139                 warnx("%s > recommended max gid value (%u)", p, USHRT_MAX);
 140                 /* return (0); This should not be fatal! */
 141         }
 142         pw->pw_gid = id;
 143
 144         if (flags & _PWSCAN_MASTER ) {
 145                 if (!(pw->pw_class = strsep(&bp, ":"))) /* class */
 146                         goto fmt;
 147                 if (pw->pw_class[0])
 148                         pw->pw_fields |= _PWF_CLASS;
 149
 150                 if (!(p = strsep(&bp, ":")))            /* change */
 151                         goto fmt;
 152                 if (p[0])
 153                         pw->pw_fields |= _PWF_CHANGE;
 154                 pw->pw_change = atol(p);
 155
 156                 if (!(p = strsep(&bp, ":")))            /* expire */
 157                         goto fmt;
 158                 if (p[0])
 159                         pw->pw_fields |= _PWF_EXPIRE;
 160                 pw->pw_expire = atol(p);
 161         }
 162         if (!(pw->pw_gecos = strsep(&bp, ":")))         /* gecos */
 163                 goto fmt;
 164         if (pw->pw_gecos[0])
 165                 pw->pw_fields |= _PWF_GECOS;
 166
 167         if (!(pw->pw_dir = strsep(&bp, ":")))           /* directory */
 168                 goto fmt;
 169         if (pw->pw_dir[0])
 170                 pw->pw_fields |= _PWF_DIR;
 171
 172         if (!(pw->pw_shell = strsep(&bp, ":")))         /* shell */
 173                 goto fmt;
 174
 175         p = pw->pw_shell;
 176         if (root && *p) {                               /* empty == /bin/sh */
 177                 for (setusershell();;) {
 178                         if (!(sh = getusershell())) {
 179                                 if (flags & _PWSCAN_WARN)
 180                                         warnx("warning, unknown root shell");
 181                                 break;
 182                         }
 183                         if (!strcmp(p, sh))
 184                                 break;
 185                 }
 186                 endusershell();
 187         }
 188         if (p[0])
 189                 pw->pw_fields |= _PWF_SHELL;
 190
 191         if ((p = strsep(&bp, ":"))) {                   /* too many */
 192 fmt:
 193                 if (flags & _PWSCAN_WARN)
 194                         warnx("corrupted entry");
 195                 return (0);
 196         }
 197         return (1);
 198 }