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  * Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved
  26  *
  27  * Copyright (c) 1980, 1988, 1993
  28  *     The Regents of the University of California.  All rights reserved.
  29  *
  30  *     @(#)fstab.c     8.1 (Berkeley) 6/4/93
  31  */
  32
  33 #include <sys/types.h>
  34
  35 #include <grp.h>
  36 #include <pwd.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <utmp.h>
  41 #include <utmpx.h>
  42
  43 #define NCACHE  64                      /* power of 2 */
  44 #define MASK    (NCACHE - 1)            /* bits to store with */
  45
  46 char *
  47 user_from_uid(uid, nouser)
  48         uid_t uid;
  49         int nouser;
  50 {
  51         static struct ncache {
  52                 uid_t   uid;
  53                 char    name[_UTX_USERSIZE + 1];
  54         } *c_uid[NCACHE];
  55         static int pwopen;
  56         static char nbuf[15];           /* 32 bits == 10 digits */
  57         register struct passwd *pw;
  58         register struct ncache **cp;
  59
  60         cp = &c_uid[uid & MASK];
  61         if (*cp == NULL || (*cp)->uid != uid || !*(*cp)->name) {
  62                 if (pwopen == 0) {
  63                         setpassent(1);
  64                         pwopen = 1;
  65                 }
  66                 if ((pw = getpwuid(uid)) == NULL) {
  67 err:
  68                         if (nouser)
  69                                 return (NULL);
  70                         (void)snprintf(nbuf, sizeof(nbuf), "%u", uid);
  71                         return (nbuf);
  72                 }
  73                 if (*cp == NULL) {
  74                         *cp = malloc(sizeof(struct ncache));
  75                         if (*cp == NULL)
  76                                 goto err;
  77                 }
  78                 (*cp)->uid = uid;
  79                 (void)strncpy((*cp)->name, pw->pw_name, _UTX_USERSIZE);
  80                 (*cp)->name[_UTX_USERSIZE] = '\0';
  81         }
  82         return ((*cp)->name);
  83 }
  84
  85 char *
  86 group_from_gid(gid, nogroup)
  87         gid_t gid;
  88         int nogroup;
  89 {
  90         static struct ncache {
  91                 gid_t   gid;
  92                 char    name[_UTX_USERSIZE + 1];
  93         } *c_gid[NCACHE];
  94         static int gropen;
  95         static char nbuf[15];           /* 32 bits == 10 digits */
  96         struct group *gr;
  97         struct ncache **cp = NULL;
  98
  99         cp = &c_gid[gid & MASK];
 100         if (*cp == NULL || (*cp)->gid != gid || !*(*cp)->name) {
 101                 if (gropen == 0) {
 102                         setgroupent(1);
 103                         gropen = 1;
 104                 }
 105                 if ((gr = getgrgid(gid)) == NULL) {
 106 err:
 107                         if (nogroup)
 108                                 return (NULL);
 109                         (void)snprintf(nbuf, sizeof(nbuf), "%u", gid);
 110                         return (nbuf);
 111                 }
 112                 if (*cp == NULL) {
 113                         *cp = malloc(sizeof(struct ncache));
 114                         if (*cp == NULL)
 115                                 goto err;
 116                 }
 117                 (*cp)->gid = gid;
 118                 (void)strncpy((*cp)->name, gr->gr_name, _UTX_USERSIZE);
 119                 (*cp)->name[_UTX_USERSIZE] = '\0';
 120         }
 121         return ((*cp)->name);
 122 }