gen/pwcache.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1989, 1993
  24  *      The Regents of the University of California.  All rights reserved.
  25  *
  26  * Redistribution and use in source and binary forms, with or without
  27  * modification, are permitted provided that the following conditions
  28  * are met:
  29  * 1. Redistributions of source code must retain the above copyright
  30  *    notice, this list of conditions and the following disclaimer.
  31  * 2. Redistributions in binary form must reproduce the above copyright
  32  *    notice, this list of conditions and the following disclaimer in the
  33  *    documentation and/or other materials provided with the distribution.
  34  * 3. All advertising materials mentioning features or use of this software
  35  *    must display the following acknowledgement:
  36  *      This product includes software developed by the University of
  37  *      California, Berkeley and its contributors.
  38  * 4. Neither the name of the University nor the names of its contributors
  39  *    may be used to endorse or promote products derived from this software
  40  *    without specific prior written permission.
  41  *
  42  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  43  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  44  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  45  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  46  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  47  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  48  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  49  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  50  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  51  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  52  * SUCH DAMAGE.
  53  */
  54
  55
  56 #include <sys/types.h>
  57
  58 #include <grp.h>
  59 #include <pwd.h>
  60 #include <stdio.h>
  61 #include <utmp.h>
  62
  63 #define NCACHE  64                      /* power of 2 */
  64 #define MASK    NCACHE - 1              /* bits to store with */
  65
  66 #ifdef NeXT
  67 /* lookupd caches users, so there's no point in another cache here */
  68 char *
  69 user_from_uid(uid, nouser)
  70         uid_t uid;
  71         int nouser;
  72 {
  73         static struct passwd *pw;
  74
  75         if ((pw = getpwuid(uid)) == NULL) return (NULL);
  76         return pw->pw_name;
  77 }
  78 #else
  79 char *
  80 user_from_uid(uid, nouser)
  81         uid_t uid;
  82         int nouser;
  83 {
  84         static struct ncache {
  85                 uid_t   uid;
  86                 char    name[UT_NAMESIZE + 1];
  87         } c_uid[NCACHE];
  88         static int pwopen;
  89         static char nbuf[15];           /* 32 bits == 10 digits */
  90         register struct passwd *pw;
  91         register struct ncache *cp;
  92
  93         cp = c_uid + (uid & MASK);
  94         if (cp->uid != uid || !*cp->name) {
  95                 if (pwopen == 0) {
  96                         setpassent(1);
  97                         pwopen = 1;
  98                 }
  99                 if ((pw = getpwuid(uid)) == NULL) {
 100                         if (nouser)
 101                                 return (NULL);
 102                         (void)snprintf(nbuf, sizeof(nbuf), "%u", uid);
 103                         return (nbuf);
 104                 }
 105                 cp->uid = uid;
 106                 (void)strncpy(cp->name, pw->pw_name, UT_NAMESIZE);
 107                 cp->name[UT_NAMESIZE] = '\0';
 108         }
 109         return (cp->name);
 110 }
 111 #endif
 112
 113 #ifdef NeXT
 114 /* lookupd caches groups, so there's no point in another cache here */
 115 char *
 116 group_from_gid(gid, nogroup)
 117         gid_t gid;
 118         int nogroup;
 119 {
 120         static struct group *gr;
 121
 122         if ((gr = getgrgid(gid)) == NULL) return (NULL);
 123         return gr->gr_name;
 124 }
 125 #else
 126 char *
 127 group_from_gid(gid, nogroup)
 128         gid_t gid;
 129         int nogroup;
 130 {
 131         static struct ncache {
 132                 gid_t   gid;
 133                 char    name[UT_NAMESIZE + 1];
 134         } c_gid[NCACHE];
 135         static int gropen;
 136         static char nbuf[15];           /* 32 bits == 10 digits */
 137         struct group *gr;
 138         struct ncache *cp;
 139
 140         cp = c_gid + (gid & MASK);
 141         if (cp->gid != gid || !*cp->name) {
 142                 if (gropen == 0) {
 143                         setgroupent(1);
 144                         gropen = 1;
 145                 }
 146                 if ((gr = getgrgid(gid)) == NULL) {
 147                         if (nogroup)
 148                                 return (NULL);
 149                         (void)snprintf(nbuf, sizeof(nbuf), "%u", gid);
 150                         return (nbuf);
 151                 }
 152                 cp->gid = gid;
 153                 (void)strncpy(cp->name, gr->gr_name, UT_NAMESIZE);
 154                 cp->name[UT_NAMESIZE] = '\0';
 155         }
 156         return (cp->name);
 157 }
 158 #endif NeXT