nscd/nscd_getgr_r.c

   1 /* Copyright (C) 1998, 1999, 2000, 2002, 2003, 2004
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Thorsten Kukuk <kukuk@uni-paderborn.de>, 1998.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <errno.h>
  22 #include <grp.h>
  23 #include <stdint.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <unistd.h>
  28 #include <sys/socket.h>
  29 #include <sys/uio.h>
  30 #include <sys/un.h>
  31 #include <not-cancel.h>
  32 #include <stdio-common/_itoa.h>
  33
  34 #include "nscd-client.h"
  35 #include "nscd_proto.h"
  36
  37 int __nss_not_use_nscd_group;
  38
  39 static int nscd_getgr_r (const char *key, size_t keylen, request_type type,
  40                          struct group *resultbuf, char *buffer,
  41                          size_t buflen, struct group **result)
  42      internal_function;
  43
  44
  45 int
  46 __nscd_getgrnam_r (const char *name, struct group *resultbuf, char *buffer,
  47                    size_t buflen, struct group **result)
  48 {
  49   return nscd_getgr_r (name, strlen (name) + 1, GETGRBYNAME, resultbuf,
  50                        buffer, buflen, result);
  51 }
  52
  53
  54 int
  55 __nscd_getgrgid_r (gid_t gid, struct group *resultbuf, char *buffer,
  56                    size_t buflen, struct group **result)
  57 {
  58   char buf[3 * sizeof (gid_t)];
  59   buf[sizeof (buf) - 1] = '\0';
  60   char *cp = _itoa_word (gid, buf + sizeof (buf) - 1, 10, 0);
  61
  62   return nscd_getgr_r (cp, buf + sizeof (buf) - cp, GETGRBYGID, resultbuf,
  63                        buffer, buflen, result);
  64 }
  65
  66
  67 static int
  68 internal_function
  69 nscd_getgr_r (const char *key, size_t keylen, request_type type,
  70               struct group *resbuf, char *buffer, size_t buflen,
  71               struct group **result)
  72 {
  73   gr_response_header gr_resp;
  74   int sock = __nscd_open_socket (key, keylen, type, &gr_resp,
  75                                  sizeof (gr_resp));
  76   if (sock == -1)
  77     {
  78       __nss_not_use_nscd_group = 1;
  79       return -1;
  80     }
  81
  82   /* No value found so far.  */
  83   int retval = -1;
  84   *result = NULL;
  85
  86   if (gr_resp.found == -1)
  87     {
  88       /* The daemon does not cache this database.  */
  89       __nss_not_use_nscd_group = 1;
  90       goto out;
  91     }
  92
  93   if (gr_resp.found == 1)
  94     {
  95       struct iovec vec[2];
  96       uint32_t *len;
  97       char *p = buffer;
  98       size_t total_len;
  99       uintptr_t align;
 100       nscd_ssize_t cnt;
 101
 102       /* Now allocate the buffer the array for the group members.  We must
 103          align the pointer.  */
 104       align = ((__alignof__ (char *) - (p - ((char *) 0)))
 105                & (__alignof__ (char *) - 1));
 106       total_len = align + (1 + gr_resp.gr_mem_cnt) * sizeof (char *)
 107                   + gr_resp.gr_name_len + gr_resp.gr_passwd_len;
 108       if (__builtin_expect (buflen < total_len, 0))
 109         {
 110         no_room:
 111           __set_errno (ERANGE);
 112           retval = ERANGE;
 113           goto out;
 114         }
 115       buflen -= total_len;
 116
 117       p += align;
 118       resbuf->gr_mem = (char **) p;
 119       p += (1 + gr_resp.gr_mem_cnt) * sizeof (char *);
 120
 121       /* Set pointers for strings.  */
 122       resbuf->gr_name = p;
 123       p += gr_resp.gr_name_len;
 124       resbuf->gr_passwd = p;
 125       p += gr_resp.gr_passwd_len;
 126
 127       /* Fill in what we know now.  */
 128       resbuf->gr_gid = gr_resp.gr_gid;
 129
 130       /* Allocate array to store lengths.  */
 131       len = (uint32_t *) alloca (gr_resp.gr_mem_cnt * sizeof (uint32_t));
 132
 133       total_len = gr_resp.gr_mem_cnt * sizeof (uint32_t);
 134       vec[0].iov_base = len;
 135       vec[0].iov_len = total_len;
 136       vec[1].iov_base = resbuf->gr_name;
 137       vec[1].iov_len = gr_resp.gr_name_len + gr_resp.gr_passwd_len;
 138       total_len += gr_resp.gr_name_len + gr_resp.gr_passwd_len;
 139
 140       /* Get this data.  */
 141       size_t n = TEMP_FAILURE_RETRY (__readv (sock, vec, 2));
 142       if (__builtin_expect (n != total_len, 0))
 143         goto out;
 144
 145       /* Clear the terminating entry.  */
 146       resbuf->gr_mem[gr_resp.gr_mem_cnt] = NULL;
 147
 148       /* Prepare reading the group members.  */
 149       total_len = 0;
 150       for (cnt = 0; cnt < gr_resp.gr_mem_cnt; ++cnt)
 151         {
 152           resbuf->gr_mem[cnt] = p;
 153           total_len += len[cnt];
 154           p += len[cnt];
 155         }
 156
 157       if (__builtin_expect (total_len > buflen, 0))
 158         goto no_room;
 159
 160       if (gr_resp.gr_mem_cnt > 0
 161           && __builtin_expect (TEMP_FAILURE_RETRY (__read (sock,
 162                                                            resbuf->gr_mem[0],
 163                                                            total_len))
 164                                != total_len, 0))
 165         {
 166           /* The `errno' to some value != ERANGE.  */
 167           __set_errno (ENOENT);
 168           retval = ENOENT;
 169         }
 170       else
 171         {
 172           retval = 0;
 173           *result = resbuf;
 174         }
 175     }
 176   else
 177     {
 178       /* The `errno' to some value != ERANGE.  */
 179       __set_errno (ENOENT);
 180       /* Even though we have not found anything, the result is zero.  */
 181       retval = 0;
 182     }
 183
 184  out:
 185   close_not_cancel_no_status (sock);
 186
 187   return retval;
 188 }