source/nsswitch/wins.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 2.0
   4    a WINS nsswitch module
   5    Copyright (C) Andrew Tridgell 1999
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20
  21 */
  22
  23 #define NO_SYSLOG
  24
  25 #include "includes.h"
  26 #include <nss.h>
  27
  28 extern int DEBUGLEVEL;
  29
  30 #ifndef INADDRSZ
  31 #define INADDRSZ 4
  32 #endif
  33
  34 /* Use our own create socket code so we don't recurse.... */
  35
  36 static int wins_lookup_open_socket_in(void)
  37 {
  38         struct sockaddr_in sock;
  39         int val=1;
  40         int res;
  41
  42         memset((char *)&sock,'\0',sizeof(sock));
  43
  44 #ifdef HAVE_SOCK_SIN_LEN
  45         sock.sin_len = sizeof(sock);
  46 #endif
  47         sock.sin_port = 0;
  48         sock.sin_family = AF_INET;
  49         sock.sin_addr.s_addr = interpret_addr("0.0.0.0");
  50         res = socket(AF_INET, SOCK_DGRAM, 0);
  51         if (res == -1)
  52                 return -1;
  53
  54         setsockopt(res,SOL_SOCKET,SO_REUSEADDR,(char *)&val,sizeof(val));
  55 #ifdef SO_REUSEPORT
  56         setsockopt(res,SOL_SOCKET,SO_REUSEPORT,(char *)&val,sizeof(val));
  57 #endif /* SO_REUSEPORT */
  58
  59         /* now we've got a socket - we need to bind it */
  60
  61         if (bind(res, (struct sockaddr * ) &sock,sizeof(sock)) < 0)
  62                 return(-1);
  63
  64         return res;
  65 }
  66
  67 struct in_addr *lookup_backend(const char *name, int *count)
  68 {
  69         int fd;
  70         static int initialised;
  71         struct in_addr *ret;
  72         struct in_addr  p;
  73         int j;
  74
  75         if (!initialised) {
  76                 initialised = 1;
  77                 DEBUGLEVEL = 0;
  78                 TimeInit();
  79                 setup_logging("nss_wins",True);
  80                 lp_load(CONFIGFILE,True,False,False);
  81                 load_interfaces();
  82         }
  83
  84         *count = 0;
  85
  86         fd = wins_lookup_open_socket_in();
  87         if (fd == -1)
  88                 return NULL;
  89
  90         set_socket_options(fd,"SO_BROADCAST");
  91
  92 /* The next four lines commented out by JHT
  93    and replaced with the four lines following */
  94 /*      if( !zero_ip( wins_ip ) ) {
  95  *              ret = name_query( fd, name, 0x20, False, True, wins_src_ip(), count );
  96  *              goto out;
  97  *      }
  98  */
  99         p = wins_srv_ip();
 100         if( !zero_ip(p) ) {
 101                 ret = name_query(fd,name,0x20,False,True, p, count);
 102                 goto out;
 103         }
 104
 105         if (lp_wins_support()) {
 106                 /* we are our own WINS server */
 107                 ret = name_query(fd,name,0x20,False,True, *interpret_addr2("127.0.0.1"), count);
 108                 goto out;
 109         }
 110
 111         /* uggh, we have to broadcast to each interface in turn */
 112         for (j=iface_count() - 1;
 113              j >= 0;
 114              j--) {
 115                 struct in_addr *bcast = iface_n_bcast(j);
 116                 ret = name_query(fd,name,0x20,True,True,*bcast,count);
 117                 if (ret) break;
 118         }
 119
 120  out:
 121
 122         close(fd);
 123         return ret;
 124 }
 125
 126
 127 /****************************************************************************
 128 gethostbyname() - we ignore any domain portion of the name and only
 129 handle names that are at most 15 characters long
 130   **************************************************************************/
 131 enum nss_status
 132 _nss_wins_gethostbyname_r(const char *name, struct hostent *he,
 133                           char *buffer, size_t buflen, int *errnop,
 134                           int *h_errnop)
 135 {
 136         char **host_addresses;
 137         struct in_addr *ip_list;
 138         int i, count;
 139         size_t namelen = strlen(name) + 1;
 140
 141         memset(he, '\0', sizeof(*he));
 142
 143         ip_list = lookup_backend(name, &count);
 144         if (!ip_list) {
 145                 return NSS_STATUS_NOTFOUND;
 146         }
 147
 148         if (buflen < namelen + (2*count+1)*INADDRSZ) {
 149                 /* no ENOMEM error type?! */
 150                 return NSS_STATUS_NOTFOUND;
 151         }
 152
 153
 154         host_addresses = (char **)buffer;
 155         he->h_addr_list = host_addresses;
 156         host_addresses[count] = NULL;
 157         buffer += (count + 1) * INADDRSZ;
 158         buflen += (count + 1) * INADDRSZ;
 159         he->h_addrtype = AF_INET;
 160         he->h_length = INADDRSZ;
 161
 162         for (i=0;i<count;i++) {
 163                 memcpy(buffer, &ip_list[i].s_addr, INADDRSZ);
 164                 *host_addresses = buffer;
 165                 buffer += INADDRSZ;
 166                 buflen -= INADDRSZ;
 167                 host_addresses++;
 168         }
 169
 170         if (ip_list)
 171                 free(ip_list);
 172
 173         memcpy(buffer, name, namelen);
 174         he->h_name = buffer;
 175
 176         return NSS_STATUS_SUCCESS;
 177 }