nscd/nscd_getgr_r.c

   1 /* Copyright (C) 1998, 1999 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);
  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 nscd_getgr_r (const char *key, size_t keylen, request_type type,
  93               struct group *resultbuf, char *buffer, size_t buflen)
  94 {
  95   int sock = open_socket ();
  96   request_header req;
  97   gr_response_header gr_resp;
  98   ssize_t nbytes;
  99   struct iovec vec[2];
 100
 101   if (sock == -1)
 102     {
 103       __nss_not_use_nscd_group = 1;
 104       return 1;
 105     }
 106
 107   req.version = NSCD_VERSION;
 108   req.type = type;
 109   req.key_len = keylen;
 110
 111   vec[0].iov_base = &req;
 112   vec[0].iov_len = sizeof (request_header);
 113   vec[1].iov_base = (void *) key;
 114   vec[1].iov_len = keylen;
 115
 116   if (__writev (sock, vec, 2) != sizeof (request_header) + keylen)
 117     {
 118       __close (sock);
 119       return 1;
 120     }
 121
 122   nbytes = __read (sock, &gr_resp, sizeof (gr_response_header));
 123   if (nbytes != sizeof (gr_response_header))
 124     {
 125       __close (sock);
 126       return 1;
 127     }
 128
 129   if (gr_resp.found == -1)
 130     {
 131       /* The daemon does not cache this database.  */
 132       __close (sock);
 133       __nss_not_use_nscd_group = 1;
 134       return 1;
 135     }
 136
 137   if (gr_resp.found == 1)
 138     {
 139       size_t *len;
 140       char *p = buffer;
 141       size_t total_len;
 142       uintptr_t align;
 143       size_t cnt;
 144
 145       /* Now allocate the buffer the array for the group members.  We must
 146          align the pointer.  */
 147       align = ((__alignof__ (char *) - (p - ((char *) 0)))
 148                & (__alignof__ (char *) - 1));
 149       if (buflen < (align + (1 + gr_resp.gr_mem_cnt) * sizeof (char *)
 150                     + gr_resp.gr_name_len + gr_resp.gr_passwd_len))
 151         {
 152         no_room:
 153           __set_errno (ERANGE);
 154           __close (sock);
 155           return -1;
 156         }
 157
 158       p += align;
 159       resultbuf->gr_mem = (char **) p;
 160       p += (1 + gr_resp.gr_mem_cnt) * sizeof (char *);
 161       buflen -= align + (1 + gr_resp.gr_mem_cnt) * sizeof (char *);
 162
 163       /* Set pointers for strings.  */
 164       resultbuf->gr_name = p;
 165       p += gr_resp.gr_name_len;
 166       resultbuf->gr_passwd = p;
 167       p += gr_resp.gr_passwd_len;
 168
 169       /* Fill in what we know now.  */
 170       resultbuf->gr_gid = gr_resp.gr_gid;
 171
 172       /* Allocate array to store lengths.  */
 173       len = alloca (gr_resp.gr_mem_cnt * sizeof (size_t));
 174
 175       total_len = gr_resp.gr_mem_cnt * sizeof (size_t);
 176       vec[0].iov_base = len;
 177       vec[0].iov_len = total_len;
 178       vec[1].iov_base = resultbuf->gr_name;
 179       vec[1].iov_len = gr_resp.gr_name_len + gr_resp.gr_passwd_len;
 180       total_len += gr_resp.gr_name_len + gr_resp.gr_passwd_len;
 181
 182       buflen -= total_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           return -1;
 210         }
 211
 212       __close (sock);
 213       return 0;
 214     }
 215   else
 216     {
 217       __close (sock);
 218       return -1;
 219     }
 220 }