gen/pwcache.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * Copyright (c) 1989, 1993
  27  *      The Regents of the University of California.  All rights reserved.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  * 1. Redistributions of source code must retain the above copyright
  33  *    notice, this list of conditions and the following disclaimer.
  34  * 2. Redistributions in binary form must reproduce the above copyright
  35  *    notice, this list of conditions and the following disclaimer in the
  36  *    documentation and/or other materials provided with the distribution.
  37  * 3. All advertising materials mentioning features or use of this software
  38  *    must display the following acknowledgement:
  39  *      This product includes software developed by the University of
  40  *      California, Berkeley and its contributors.
  41  * 4. Neither the name of the University nor the names of its contributors
  42  *    may be used to endorse or promote products derived from this software
  43  *    without specific prior written permission.
  44  *
  45  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  55  * SUCH DAMAGE.
  56  */
  57
  58
  59 #include <sys/types.h>
  60
  61 #include <grp.h>
  62 #include <pwd.h>
  63 #include <stdio.h>
  64 #include <utmp.h>
  65
  66 #define NCACHE  64                      /* power of 2 */
  67 #define MASK    NCACHE - 1              /* bits to store with */
  68
  69 #ifdef NeXT
  70 /* lookupd caches users, so there's no point in another cache here */
  71 char *
  72 user_from_uid(uid, nouser)
  73         uid_t uid;
  74         int nouser;
  75 {
  76         static struct passwd *pw;
  77
  78         if ((pw = getpwuid(uid)) == NULL) return (NULL);
  79         return pw->pw_name;
  80 }
  81 #else
  82 char *
  83 user_from_uid(uid, nouser)
  84         uid_t uid;
  85         int nouser;
  86 {
  87         static struct ncache {
  88                 uid_t   uid;
  89                 char    name[UT_NAMESIZE + 1];
  90         } c_uid[NCACHE];
  91         static int pwopen;
  92         static char nbuf[15];           /* 32 bits == 10 digits */
  93         register struct passwd *pw;
  94         register struct ncache *cp;
  95
  96         cp = c_uid + (uid & MASK);
  97         if (cp->uid != uid || !*cp->name) {
  98                 if (pwopen == 0) {
  99                         setpassent(1);
 100                         pwopen = 1;
 101                 }
 102                 if ((pw = getpwuid(uid)) == NULL) {
 103                         if (nouser)
 104                                 return (NULL);
 105                         (void)snprintf(nbuf, sizeof(nbuf), "%u", uid);
 106                         return (nbuf);
 107                 }
 108                 cp->uid = uid;
 109                 (void)strncpy(cp->name, pw->pw_name, UT_NAMESIZE);
 110                 cp->name[UT_NAMESIZE] = '\0';
 111         }
 112         return (cp->name);
 113 }
 114 #endif
 115
 116 #ifdef NeXT
 117 /* lookupd caches groups, so there's no point in another cache here */
 118 char *
 119 group_from_gid(gid, nogroup)
 120         gid_t gid;
 121         int nogroup;
 122 {
 123         static struct group *gr;
 124
 125         if ((gr = getgrgid(gid)) == NULL) return (NULL);
 126         return gr->gr_name;
 127 }
 128 #else
 129 char *
 130 group_from_gid(gid, nogroup)
 131         gid_t gid;
 132         int nogroup;
 133 {
 134         static struct ncache {
 135                 gid_t   gid;
 136                 char    name[UT_NAMESIZE + 1];
 137         } c_gid[NCACHE];
 138         static int gropen;
 139         static char nbuf[15];           /* 32 bits == 10 digits */
 140         struct group *gr;
 141         struct ncache *cp;
 142
 143         cp = c_gid + (gid & MASK);
 144         if (cp->gid != gid || !*cp->name) {
 145                 if (gropen == 0) {
 146                         setgroupent(1);
 147                         gropen = 1;
 148                 }
 149                 if ((gr = getgrgid(gid)) == NULL) {
 150                         if (nogroup)
 151                                 return (NULL);
 152                         (void)snprintf(nbuf, sizeof(nbuf), "%u", gid);
 153                         return (nbuf);
 154                 }
 155                 cp->gid = gid;
 156                 (void)strncpy(cp->name, gr->gr_name, UT_NAMESIZE);
 157                 cp->name[UT_NAMESIZE] = '\0';
 158         }
 159         return (cp->name);
 160 }
 161 #endif NeXT