openbsd-compat/pwcache.c

   1 /*      $OpenBSD: pwcache.c,v 1.9 2005/08/08 08:05:34 espie Exp $ */
   2 /*
   3  * Copyright (c) 1989, 1993
   4  *      The Regents of the University of California.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. Neither the name of the University nor the names of its contributors
  15  *    may be used to endorse or promote products derived from this software
  16  *    without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  */
  30
  31 /* OPENBSD ORIGINAL: lib/libc/gen/pwcache.c */
  32
  33 #include "includes.h"
  34
  35 #include <sys/types.h>
  36
  37 #include <grp.h>
  38 #include <pwd.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42
  43 #define NCACHE  64                      /* power of 2 */
  44 #define MASK    (NCACHE - 1)            /* bits to store with */
  45
  46 #ifndef HAVE_USER_FROM_UID
  47 char *
  48 user_from_uid(uid_t uid, int nouser)
  49 {
  50         static struct ncache {
  51                 uid_t   uid;
  52                 char    *name;
  53         } c_uid[NCACHE];
  54         static int pwopen;
  55         static char nbuf[15];           /* 32 bits == 10 digits */
  56         struct passwd *pw;
  57         struct ncache *cp;
  58
  59         cp = c_uid + (uid & MASK);
  60         if (cp->uid != uid || cp->name == NULL) {
  61                 if (pwopen == 0) {
  62 #ifdef HAVE_SETPASSENT
  63                         setpassent(1);
  64 #endif
  65                         pwopen = 1;
  66                 }
  67                 if ((pw = getpwuid(uid)) == NULL) {
  68                         if (nouser)
  69                                 return (NULL);
  70                         (void)snprintf(nbuf, sizeof(nbuf), "%u", uid);
  71                 }
  72                 cp->uid = uid;
  73                 if (cp->name != NULL)
  74                         free(cp->name);
  75                 cp->name = strdup(pw ? pw->pw_name : nbuf);
  76         }
  77         return (cp->name);
  78 }
  79 #endif
  80
  81 #ifndef HAVE_GROUP_FROM_GID
  82 char *
  83 group_from_gid(gid_t gid, int nogroup)
  84 {
  85         static struct ncache {
  86                 gid_t   gid;
  87                 char    *name;
  88         } c_gid[NCACHE];
  89         static int gropen;
  90         static char nbuf[15];           /* 32 bits == 10 digits */
  91         struct group *gr;
  92         struct ncache *cp;
  93
  94         cp = c_gid + (gid & MASK);
  95         if (cp->gid != gid || cp->name == NULL) {
  96                 if (gropen == 0) {
  97 #ifdef HAVE_SETGROUPENT
  98                         setgroupent(1);
  99 #endif
 100                         gropen = 1;
 101                 }
 102                 if ((gr = getgrgid(gid)) == NULL) {
 103                         if (nogroup)
 104                                 return (NULL);
 105                         (void)snprintf(nbuf, sizeof(nbuf), "%u", gid);
 106                 }
 107                 cp->gid = gid;
 108                 if (cp->name != NULL)
 109                         free(cp->name);
 110                 cp->name = strdup(gr ? gr->gr_name : nbuf);
 111         }
 112         return (cp->name);
 113 }
 114 #endif