util.subproj/pwcache.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.1 (the "License").  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License.
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24
  25 #include <sys/types.h>
  26
  27 #include <grp.h>
  28 #include <pwd.h>
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <utmp.h>
  33
  34 #define NCACHE  64                      /* power of 2 */
  35 #define MASK    (NCACHE - 1)            /* bits to store with */
  36
  37 char *
  38 user_from_uid(uid, nouser)
  39         uid_t uid;
  40         int nouser;
  41 {
  42         static struct ncache {
  43                 uid_t   uid;
  44                 char    name[UT_NAMESIZE + 1];
  45         } *c_uid[NCACHE];
  46         static int pwopen;
  47         static char nbuf[15];           /* 32 bits == 10 digits */
  48         register struct passwd *pw;
  49         register struct ncache **cp;
  50
  51         cp = &c_uid[uid & MASK];
  52         if (*cp == NULL || (*cp)->uid != uid || !*(*cp)->name) {
  53                 if (pwopen == 0) {
  54                         setpassent(1);
  55                         pwopen = 1;
  56                 }
  57                 if ((pw = getpwuid(uid)) == NULL) {
  58 err:
  59                         if (nouser)
  60                                 return (NULL);
  61                         (void)snprintf(nbuf, sizeof(nbuf), "%u", uid);
  62                         return (nbuf);
  63                 }
  64                 if (*cp == NULL) {
  65                         *cp = malloc(sizeof(struct ncache));
  66                         if (*cp == NULL)
  67                                 goto err;
  68                 }
  69                 (*cp)->uid = uid;
  70                 (void)strncpy((*cp)->name, pw->pw_name, UT_NAMESIZE);
  71                 (*cp)->name[UT_NAMESIZE] = '\0';
  72         }
  73         return ((*cp)->name);
  74 }
  75
  76 char *
  77 group_from_gid(gid, nogroup)
  78         gid_t gid;
  79         int nogroup;
  80 {
  81         static struct ncache {
  82                 gid_t   gid;
  83                 char    name[UT_NAMESIZE + 1];
  84         } *c_gid[NCACHE];
  85         static int gropen;
  86         static char nbuf[15];           /* 32 bits == 10 digits */
  87         struct group *gr;
  88         struct ncache **cp = NULL;
  89
  90         cp = &c_gid[gid & MASK];
  91         if (*cp == NULL || (*cp)->gid != gid || !*(*cp)->name) {
  92                 if (gropen == 0) {
  93                         setgroupent(1);
  94                         gropen = 1;
  95                 }
  96                 if ((gr = getgrgid(gid)) == NULL) {
  97 err:
  98                         if (nogroup)
  99                                 return (NULL);
 100                         (void)snprintf(nbuf, sizeof(nbuf), "%u", gid);
 101                         return (nbuf);
 102                 }
 103                 if (*cp == NULL) {
 104                         *cp = malloc(sizeof(struct ncache));
 105                         if (*cp == NULL)
 106                                 goto err;
 107                 }
 108                 (*cp)->gid = gid;
 109                 (void)strncpy((*cp)->name, gr->gr_name, UT_NAMESIZE);
 110                 (*cp)->name[UT_NAMESIZE] = '\0';
 111         }
 112         return ((*cp)->name);
 113 }