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