util.subproj/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) 1995 NeXT Computer, Inc. All Rights Reserved
  27  *
  28  * Copyright (c) 1989, 1993
  29  *      The Regents of the University of California.  All rights reserved.
  30  *
  31  * The NEXTSTEP Software License Agreement specifies the terms
  32  * and conditions for redistribution.
  33  *
  34  *      @(#)pwcache.c   8.1 (Berkeley) 6/4/93
  35  */
  36
  37
  38 #include <sys/types.h>
  39
  40 #include <grp.h>
  41 #include <pwd.h>
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44 #include <string.h>
  45 #include <utmp.h>
  46
  47 #define NCACHE  64                      /* power of 2 */
  48 #define MASK    (NCACHE - 1)            /* bits to store with */
  49
  50 char *
  51 user_from_uid(uid, nouser)
  52         uid_t uid;
  53         int nouser;
  54 {
  55         static struct ncache {
  56                 uid_t   uid;
  57                 char    name[UT_NAMESIZE + 1];
  58         } *c_uid[NCACHE];
  59         static int pwopen;
  60         static char nbuf[15];           /* 32 bits == 10 digits */
  61         register struct passwd *pw;
  62         register struct ncache **cp;
  63
  64         cp = &c_uid[uid & MASK];
  65         if (*cp == NULL || (*cp)->uid != uid || !*(*cp)->name) {
  66                 if (pwopen == 0) {
  67                         setpassent(1);
  68                         pwopen = 1;
  69                 }
  70                 if ((pw = getpwuid(uid)) == NULL) {
  71 err:
  72                         if (nouser)
  73                                 return (NULL);
  74                         (void)snprintf(nbuf, sizeof(nbuf), "%u", uid);
  75                         return (nbuf);
  76                 }
  77                 if (*cp == NULL) {
  78                         *cp = malloc(sizeof(struct ncache));
  79                         if (*cp == NULL)
  80                                 goto err;
  81                 }
  82                 (*cp)->uid = uid;
  83                 (void)strncpy((*cp)->name, pw->pw_name, UT_NAMESIZE);
  84                 (*cp)->name[UT_NAMESIZE] = '\0';
  85         }
  86         return ((*cp)->name);
  87 }
  88
  89 char *
  90 group_from_gid(gid, nogroup)
  91         gid_t gid;
  92         int nogroup;
  93 {
  94         static struct ncache {
  95                 gid_t   gid;
  96                 char    name[UT_NAMESIZE + 1];
  97         } *c_gid[NCACHE];
  98         static int gropen;
  99         static char nbuf[15];           /* 32 bits == 10 digits */
 100         struct group *gr;
 101         struct ncache **cp = NULL;
 102
 103         cp = &c_gid[gid & MASK];
 104         if (*cp == NULL || (*cp)->gid != gid || !*(*cp)->name) {
 105                 if (gropen == 0) {
 106                         setgroupent(1);
 107                         gropen = 1;
 108                 }
 109                 if ((gr = getgrgid(gid)) == NULL) {
 110 err:
 111                         if (nogroup)
 112                                 return (NULL);
 113                         (void)snprintf(nbuf, sizeof(nbuf), "%u", gid);
 114                         return (nbuf);
 115                 }
 116                 if (*cp == NULL) {
 117                         *cp = malloc(sizeof(struct ncache));
 118                         if (*cp == NULL)
 119                                 goto err;
 120                 }
 121                 (*cp)->gid = gid;
 122                 (void)strncpy((*cp)->name, gr->gr_name, UT_NAMESIZE);
 123                 (*cp)->name[UT_NAMESIZE] = '\0';
 124         }
 125         return ((*cp)->name);
 126 }