source/lib/util_pw.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Safe versions of getpw* calls
   5
   6    Copyright (C) Andrew Bartlett 2002
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 #include "includes.h"
  24
  25 static struct passwd *talloc_copy_passwd(TALLOC_CTX *mem_ctx,
  26                                          const struct passwd *from)
  27 {
  28         struct passwd *ret = TALLOC_P(mem_ctx, struct passwd);
  29         ret->pw_name = talloc_strdup(ret, from->pw_name);
  30         ret->pw_passwd = talloc_strdup(ret, from->pw_passwd);
  31         ret->pw_uid = from->pw_uid;
  32         ret->pw_gid = from->pw_gid;
  33         ret->pw_gecos = talloc_strdup(ret, from->pw_gecos);
  34         ret->pw_dir = talloc_strdup(ret, from->pw_dir);
  35         ret->pw_shell = talloc_strdup(ret, from->pw_shell);
  36         return ret;
  37 }
  38
  39 #define PWNAMCACHE_SIZE 4
  40 static struct passwd **pwnam_cache = NULL;
  41
  42 static void init_pwnam_cache(void)
  43 {
  44         if (pwnam_cache != NULL)
  45                 return;
  46
  47         pwnam_cache = TALLOC_ZERO_ARRAY(NULL, struct passwd *,
  48                                         PWNAMCACHE_SIZE);
  49         if (pwnam_cache == NULL) {
  50                 smb_panic("Could not init pwnam_cache\n");
  51         }
  52
  53         return;
  54 }
  55
  56 void flush_pwnam_cache(void)
  57 {
  58         talloc_free(pwnam_cache);
  59         pwnam_cache = NULL;
  60         init_pwnam_cache();
  61 }
  62
  63 struct passwd *getpwnam_alloc(TALLOC_CTX *mem_ctx, const char *name)
  64 {
  65         int i;
  66
  67         struct passwd *temp;
  68
  69         init_pwnam_cache();
  70
  71         for (i=0; i<PWNAMCACHE_SIZE; i++) {
  72                 if ((pwnam_cache[i] != NULL) &&
  73                     (strcmp(name, pwnam_cache[i]->pw_name) == 0)) {
  74                         DEBUG(10, ("Got %s from pwnam_cache\n", name));
  75                         return talloc_reference(mem_ctx, pwnam_cache[i]);
  76                 }
  77         }
  78
  79         temp = sys_getpwnam(name);
  80
  81         if (!temp) {
  82 #if 0
  83                 if (errno == ENOMEM) {
  84                         /* what now? */
  85                 }
  86 #endif
  87                 return NULL;
  88         }
  89
  90         for (i=0; i<PWNAMCACHE_SIZE; i++) {
  91                 if (pwnam_cache[i] == NULL)
  92                         break;
  93         }
  94
  95         if (i == PWNAMCACHE_SIZE)
  96                 i = rand() % PWNAMCACHE_SIZE;
  97
  98         if (pwnam_cache[i] != NULL) {
  99                 talloc_free(pwnam_cache[i]);
 100         }
 101
 102         pwnam_cache[i] = talloc_copy_passwd(pwnam_cache, temp);
 103
 104         if (mem_ctx != NULL) {
 105                 return talloc_reference(mem_ctx, pwnam_cache[i]);
 106         }
 107
 108         return talloc_copy_passwd(NULL, pwnam_cache[i]);
 109 }
 110
 111 struct passwd *getpwuid_alloc(TALLOC_CTX *mem_ctx, uid_t uid)
 112 {
 113         struct passwd *temp;
 114
 115         temp = sys_getpwuid(uid);
 116
 117         if (!temp) {
 118 #if 0
 119                 if (errno == ENOMEM) {
 120                         /* what now? */
 121                 }
 122 #endif
 123                 return NULL;
 124         }
 125
 126         return talloc_copy_passwd(mem_ctx, temp);
 127 }