nscd/nscd_getgr_r.c

   1 /* Copyright (C) 1998 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 <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <unistd.h>
  26 #include <sys/socket.h>
  27 #include <sys/uio.h>
  28 #include <sys/un.h>
  29
  30 #include "nscd.h"
  31 #include "nscd_proto.h"
  32
  33 int __nss_not_use_nscd_group;
  34
  35 static int nscd_getgr_r (const char *key, size_t keylen, request_type type,
  36                          struct group *resultbuf, char *buffer,
  37                          size_t buflen);
  38
  39
  40 int
  41 __nscd_getgrnam_r (const char *name, struct group *resultbuf, char *buffer,
  42                    size_t buflen)
  43 {
  44   return nscd_getgr_r (name, strlen (name) + 1, GETGRBYNAME, resultbuf,
  45                        buffer, buflen);
  46 }
  47
  48
  49 int
  50 __nscd_getgrgid_r (gid_t gid, struct group *resultbuf, char *buffer,
  51                    size_t buflen)
  52 {
  53   char buf[12];
  54   size_t n;
  55
  56   n = __snprintf (buf, sizeof (buf), "%d", gid) + 1;
  57
  58   return nscd_getgr_r (buf, n, GETGRBYGID, resultbuf, buffer, buflen);
  59 }
  60
  61
  62 /* Create a socket connected to a name. */
  63 static int
  64 open_socket (void)
  65 {
  66   struct sockaddr_un addr;
  67   int sock;
  68   int saved_errno = errno;
  69
  70   sock = __socket (PF_UNIX, SOCK_STREAM, 0);
  71   if (sock < 0)
  72     {
  73       __set_errno (saved_errno);
  74       return -1;
  75     }
  76
  77   addr.sun_family = AF_UNIX;
  78   strcpy (addr.sun_path, _PATH_NSCDSOCKET);
  79   if (__connect (sock, (struct sockaddr *) &addr, sizeof (addr)) < 0)
  80     {
  81       __close (sock);
  82       __set_errno (saved_errno);
  83       return -1;
  84     }
  85
  86   return sock;
  87 }
  88
  89
  90 static int
  91 nscd_getgr_r (const char *key, size_t keylen, request_type type,
  92               struct group *resultbuf, char *buffer, size_t buflen)
  93 {
  94   int sock = open_socket ();
  95   request_header req;
  96   gr_response_header gr_resp;
  97   ssize_t nbytes;
  98   struct iovec vec[2];
  99
 100   if (sock == -1)
 101     {
 102       __nss_not_use_nscd_group = 1;
 103       return 1;
 104     }
 105
 106   req.version = NSCD_VERSION;
 107   req.type = type;
 108   req.key_len = keylen;
 109
 110   vec[0].iov_base = &req;
 111   vec[0].iov_len = sizeof (request_header);
 112   vec[1].iov_base = (void *) key;
 113   vec[1].iov_len = keylen;
 114
 115   if (__writev (sock, vec, 2) != sizeof (request_header) + keylen)
 116     {
 117       __close (sock);
 118       return 1;
 119     }
 120
 121   nbytes = __read (sock, &gr_resp, sizeof (gr_response_header));
 122   if (nbytes != sizeof (gr_response_header))
 123     {
 124       __close (sock);
 125       return 1;
 126     }
 127
 128   if (gr_resp.found == -1)
 129     {
 130       /* The daemon does not cache this database.  */
 131       __close (sock);
 132       __nss_not_use_nscd_group = 1;
 133       return 1;
 134     }
 135
 136   if (gr_resp.found == 1)
 137     {
 138       size_t *len;
 139       char *p = buffer;
 140       size_t total_len;
 141       uintptr_t align;
 142       size_t cnt;
 143
 144       /* Now allocate the buffer the array for the group members.  We must
 145          align the pointer.  */
 146       align = ((__alignof__ (char *) - (p - ((char *) 0)))
 147                & (__alignof__ (char *) - 1));
 148       if (buflen < (align + (1 + gr_resp.gr_mem_cnt) * sizeof (char *)
 149                     + gr_resp.gr_name_len + gr_resp.gr_passwd_len))
 150         {
 151         no_room:
 152           __set_errno (ERANGE);
 153           __close (sock);
 154           return -1;
 155         }
 156
 157       p += align;
 158       resultbuf->gr_mem = (char **) p;
 159       p += (1 + gr_resp.gr_mem_cnt) * sizeof (char *);
 160       buflen -= align + (1 + gr_resp.gr_mem_cnt) * sizeof (char *);
 161
 162       /* Set pointers for strings.  */
 163       resultbuf->gr_name = p;
 164       p += gr_resp.gr_name_len;
 165       resultbuf->gr_passwd = p;
 166       p += gr_resp.gr_passwd_len;
 167
 168       /* Fill in what we know now.  */
 169       resultbuf->gr_gid = gr_resp.gr_gid;
 170
 171       /* Allocate array to store lengths.  */
 172       len = alloca (gr_resp.gr_mem_cnt * sizeof (size_t));
 173
 174       total_len = gr_resp.gr_mem_cnt * sizeof (size_t);
 175       vec[0].iov_base = len;
 176       vec[0].iov_len = total_len;
 177       vec[1].iov_base = resultbuf->gr_name;
 178       vec[1].iov_len = gr_resp.gr_name_len + gr_resp.gr_passwd_len;
 179       total_len += gr_resp.gr_name_len + gr_resp.gr_passwd_len;
 180
 181       buflen -= total_len;
 182
 183       /* Get this data.  */
 184       if (__readv (sock, vec, 2) != total_len)
 185         {
 186           __close (sock);
 187           return 1;
 188         }
 189
 190       /* Clear the terminating entry.  */
 191       resultbuf->gr_mem[gr_resp.gr_mem_cnt] = NULL;
 192
 193       /* Prepare reading the group members.  */
 194       total_len = 0;
 195       for (cnt = 0; cnt < gr_resp.gr_mem_cnt; ++cnt)
 196         {
 197           resultbuf->gr_mem[cnt] = p;
 198           total_len += len[cnt];
 199           p += len[cnt];
 200         }
 201
 202       if (total_len > buflen)
 203         goto no_room;
 204
 205       if (__read (sock, resultbuf->gr_mem[0], total_len) != total_len)
 206         {
 207           __close (sock);
 208           return -1;
 209         }
 210
 211       __close (sock);
 212       return 0;
 213     }
 214   else
 215     {
 216       __close (sock);
 217       return -1;
 218     }
 219 }