nscd/nscd_getgr_r.c

   1 /* Copyright (C) 1998, 1999, 2000 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Thorsten Kukuk <kukuk@uni-paderborn.de>, 1998.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <errno.h>
  21 #include <grp.h>
  22 #include <stdint.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <unistd.h>
  27 #include <sys/socket.h>
  28 #include <sys/uio.h>
  29 #include <sys/un.h>
  30
  31 #include "nscd-client.h"
  32 #include "nscd_proto.h"
  33
  34 int __nss_not_use_nscd_group;
  35
  36 static int nscd_getgr_r (const char *key, size_t keylen, request_type type,
  37                          struct group *resultbuf, char *buffer,
  38                          size_t buflen) internal_function;
  39
  40
  41 int
  42 __nscd_getgrnam_r (const char *name, struct group *resultbuf, char *buffer,
  43                    size_t buflen)
  44 {
  45   return nscd_getgr_r (name, strlen (name) + 1, GETGRBYNAME, resultbuf,
  46                        buffer, buflen);
  47 }
  48
  49
  50 int
  51 __nscd_getgrgid_r (gid_t gid, struct group *resultbuf, char *buffer,
  52                    size_t buflen)
  53 {
  54   char buf[12];
  55   size_t n;
  56
  57   n = __snprintf (buf, sizeof (buf), "%d", gid) + 1;
  58
  59   return nscd_getgr_r (buf, n, GETGRBYGID, resultbuf, buffer, buflen);
  60 }
  61
  62
  63 /* Create a socket connected to a name. */
  64 static int
  65 open_socket (void)
  66 {
  67   struct sockaddr_un addr;
  68   int sock;
  69   int saved_errno = errno;
  70
  71   sock = __socket (PF_UNIX, SOCK_STREAM, 0);
  72   if (sock < 0)
  73     {
  74       __set_errno (saved_errno);
  75       return -1;
  76     }
  77
  78   addr.sun_family = AF_UNIX;
  79   strcpy (addr.sun_path, _PATH_NSCDSOCKET);
  80   if (__connect (sock, (struct sockaddr *) &addr, sizeof (addr)) < 0)
  81     {
  82       __close (sock);
  83       __set_errno (saved_errno);
  84       return -1;
  85     }
  86
  87   return sock;
  88 }
  89
  90
  91 static int
  92 internal_function
  93 nscd_getgr_r (const char *key, size_t keylen, request_type type,
  94               struct group *resultbuf, char *buffer, size_t buflen)
  95 {
  96   int sock = open_socket ();
  97   request_header req;
  98   gr_response_header gr_resp;
  99   ssize_t nbytes;
 100   struct iovec vec[2];
 101
 102   if (sock == -1)
 103     {
 104       __nss_not_use_nscd_group = 1;
 105       return -1;
 106     }
 107
 108   req.version = NSCD_VERSION;
 109   req.type = type;
 110   req.key_len = keylen;
 111
 112   vec[0].iov_base = &req;
 113   vec[0].iov_len = sizeof (request_header);
 114   vec[1].iov_base = (void *) key;
 115   vec[1].iov_len = keylen;
 116
 117   if (__writev (sock, vec, 2) != sizeof (request_header) + keylen)
 118     {
 119       __close (sock);
 120       return -1;
 121     }
 122
 123   nbytes = __read (sock, &gr_resp, sizeof (gr_response_header));
 124   if (nbytes != sizeof (gr_response_header))
 125     {
 126       __close (sock);
 127       return -1;
 128     }
 129
 130   if (gr_resp.found == -1)
 131     {
 132       /* The daemon does not cache this database.  */
 133       __close (sock);
 134       __nss_not_use_nscd_group = 1;
 135       return -1;
 136     }
 137
 138   if (gr_resp.found == 1)
 139     {
 140       uint32_t *len;
 141       char *p = buffer;
 142       size_t total_len;
 143       uintptr_t align;
 144       size_t cnt;
 145
 146       /* Now allocate the buffer the array for the group members.  We must
 147          align the pointer.  */
 148       align = ((__alignof__ (char *) - (p - ((char *) 0)))
 149                & (__alignof__ (char *) - 1));
 150       total_len = align + (1 + gr_resp.gr_mem_cnt) * sizeof (char *)
 151                   + gr_resp.gr_name_len + gr_resp.gr_passwd_len;
 152       if (buflen < total_len)
 153         {
 154         no_room:
 155           __set_errno (ERANGE);
 156           __close (sock);
 157           return ERANGE;
 158         }
 159       buflen -= total_len;
 160
 161       p += align;
 162       resultbuf->gr_mem = (char **) p;
 163       p += (1 + gr_resp.gr_mem_cnt) * sizeof (char *);
 164
 165       /* Set pointers for strings.  */
 166       resultbuf->gr_name = p;
 167       p += gr_resp.gr_name_len;
 168       resultbuf->gr_passwd = p;
 169       p += gr_resp.gr_passwd_len;
 170
 171       /* Fill in what we know now.  */
 172       resultbuf->gr_gid = gr_resp.gr_gid;
 173
 174       /* Allocate array to store lengths.  */
 175       len = (uint32_t *) alloca (gr_resp.gr_mem_cnt * sizeof (uint32_t));
 176
 177       total_len = gr_resp.gr_mem_cnt * sizeof (uint32_t);
 178       vec[0].iov_base = len;
 179       vec[0].iov_len = total_len;
 180       vec[1].iov_base = resultbuf->gr_name;
 181       vec[1].iov_len = gr_resp.gr_name_len + gr_resp.gr_passwd_len;
 182       total_len += gr_resp.gr_name_len + gr_resp.gr_passwd_len;
 183
 184       /* Get this data.  */
 185       if (__readv (sock, vec, 2) != total_len)
 186         {
 187           __close (sock);
 188           return -1;
 189         }
 190
 191       /* Clear the terminating entry.  */
 192       resultbuf->gr_mem[gr_resp.gr_mem_cnt] = NULL;
 193
 194       /* Prepare reading the group members.  */
 195       total_len = 0;
 196       for (cnt = 0; cnt < gr_resp.gr_mem_cnt; ++cnt)
 197         {
 198           resultbuf->gr_mem[cnt] = p;
 199           total_len += len[cnt];
 200           p += len[cnt];
 201         }
 202
 203       if (total_len > buflen)
 204         goto no_room;
 205
 206       if (__read (sock, resultbuf->gr_mem[0], total_len) != total_len)
 207         {
 208           __close (sock);
 209           /* The `errno' to some value != ERANGE.  */
 210           __set_errno (ENOENT);
 211           return ENOENT;
 212         }
 213
 214       __close (sock);
 215       return 0;
 216     }
 217   else
 218     {
 219       __close (sock);
 220       /* The `errno' to some value != ERANGE.  */
 221       __set_errno (ENOENT);
 222       return ENOENT;
 223     }
 224 }