source/nbt_server/packet.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    packet utility functions
   5
   6    Copyright (C) Andrew Tridgell        2005
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 #include "includes.h"
  24 #include "dlinklist.h"
  25 #include "nbt_server/nbt_server.h"
  26
  27 /*
  28   we received a badly formed packet - log it
  29 */
  30 void nbtd_bad_packet(struct nbt_name_packet *packet,
  31                      const char *src_address, const char *reason)
  32 {
  33         DEBUG(2,("nbtd: bad packet '%s' from %s\n", reason, src_address));
  34         if (DEBUGLVL(5)) {
  35                 NDR_PRINT_DEBUG(nbt_name_packet, packet);
  36         }
  37 }
  38
  39
  40 /*
  41   see if an incoming packet is a broadcast packet from one of our own
  42   interfaces
  43 */
  44 BOOL nbtd_self_packet(struct nbt_name_socket *nbtsock,
  45                       struct nbt_name_packet *packet,
  46                       const char *src_address, int src_port)
  47 {
  48         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
  49                                                        struct nbtd_interface);
  50         struct nbtd_server *nbtsrv = iface->nbtsrv;
  51
  52         /* if its not a broadcast then its not considered a self packet */
  53         if (!(packet->operation & NBT_FLAG_BROADCAST)) {
  54                 return False;
  55         }
  56
  57         /* if its not from the nbt port, then it wasn't a broadcast from us */
  58         if (src_port != lp_nbt_port()) {
  59                 return False;
  60         }
  61
  62         /* this uses the fact that iface->nbtsock is our non-broadcast
  63            listen address */
  64         if (iface->nbtsock == nbtsock &&
  65             iface != iface->nbtsrv->bcast_interface) {
  66                 return False;
  67         }
  68
  69         /* we have to loop over our interface list, seeing if its from
  70            one of our own interfaces */
  71         for (iface=nbtsrv->interfaces;iface;iface=iface->next) {
  72                 if (strcmp(src_address, iface->ip_address) == 0) {
  73                         return True;
  74                 }
  75         }
  76
  77         return False;
  78 }
  79
  80
  81 /*
  82   send a name query reply
  83 */
  84 void nbtd_name_query_reply(struct nbt_name_socket *nbtsock,
  85                            struct nbt_name_packet *request_packet,
  86                            const char *src_address, int src_port,
  87                            struct nbt_name *name, uint32_t ttl,
  88                            uint16_t nb_flags, const char **addresses)
  89 {
  90         struct nbt_name_packet *packet;
  91         size_t num_addresses = str_list_length(addresses);
  92         int i;
  93
  94         if (num_addresses == 0) {
  95                 DEBUG(3,("No addresses in name query reply - failing\n"));
  96                 return;
  97         }
  98
  99         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 100         if (packet == NULL) return;
 101
 102         packet->name_trn_id = request_packet->name_trn_id;
 103         packet->ancount = 1;
 104         packet->operation =
 105                 NBT_FLAG_REPLY |
 106                 NBT_OPCODE_QUERY |
 107                 NBT_FLAG_AUTHORITIVE |
 108                 NBT_FLAG_RECURSION_DESIRED |
 109                 NBT_FLAG_RECURSION_AVAIL;
 110
 111         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 112         if (packet->answers == NULL) goto failed;
 113
 114         packet->answers[0].name     = *name;
 115         packet->answers[0].rr_type  = NBT_QTYPE_NETBIOS;
 116         packet->answers[0].rr_class = NBT_QCLASS_IP;
 117         packet->answers[0].ttl      = ttl;
 118         packet->answers[0].rdata.netbios.length = num_addresses*6;
 119         packet->answers[0].rdata.netbios.addresses =
 120                 talloc_array(packet->answers, struct nbt_rdata_address, num_addresses);
 121         if (packet->answers[0].rdata.netbios.addresses == NULL) goto failed;
 122
 123         for (i=0;i<num_addresses;i++) {
 124                 struct nbt_rdata_address *addr =
 125                         &packet->answers[0].rdata.netbios.addresses[i];
 126                 addr->nb_flags = nb_flags;
 127                 addr->ipaddr = talloc_strdup(packet->answers, addresses[i]);
 128                 if (addr->ipaddr == NULL) goto failed;
 129         }
 130
 131         DEBUG(7,("Sending name query reply for %s at %s to %s:%d\n",
 132                  nbt_name_string(packet, name), addresses[0], src_address, src_port));
 133
 134         nbt_name_reply_send(nbtsock, src_address, src_port, packet);
 135
 136 failed:
 137         talloc_free(packet);
 138 }
 139
 140
 141 /*
 142   send a negative name query reply
 143 */
 144 void nbtd_negative_name_query_reply(struct nbt_name_socket *nbtsock,
 145                                     struct nbt_name_packet *request_packet,
 146                                     const char *src_address, int src_port)
 147 {
 148         struct nbt_name_packet *packet;
 149         struct nbt_name *name = &request_packet->questions[0].name;
 150
 151         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 152         if (packet == NULL) return;
 153
 154         packet->name_trn_id = request_packet->name_trn_id;
 155         packet->ancount = 1;
 156         packet->operation =
 157                 NBT_FLAG_REPLY |
 158                 NBT_OPCODE_QUERY |
 159                 NBT_FLAG_AUTHORITIVE |
 160                 NBT_RCODE_NAM;
 161
 162         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 163         if (packet->answers == NULL) goto failed;
 164
 165         packet->answers[0].name      = *name;
 166         packet->answers[0].rr_type   = NBT_QTYPE_NULL;
 167         packet->answers[0].rr_class  = NBT_QCLASS_IP;
 168         packet->answers[0].ttl       = 0;
 169         ZERO_STRUCT(packet->answers[0].rdata);
 170
 171         DEBUG(7,("Sending negative name query reply for %s to %s:%d\n",
 172                  nbt_name_string(packet, name), src_address, src_port));
 173
 174         nbt_name_reply_send(nbtsock, src_address, src_port, packet);
 175
 176 failed:
 177         talloc_free(packet);
 178 }
 179
 180 /*
 181   send a name defense reply
 182 */
 183 void nbtd_negative_name_registration_reply(struct nbt_name_socket *nbtsock,
 184                                            struct nbt_name_packet *request_packet,
 185                                            const char *src_address, int src_port)
 186 {
 187         struct nbt_name_packet *packet;
 188         struct nbt_name *name = &request_packet->questions[0].name;
 189
 190         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 191         if (packet == NULL) return;
 192
 193         packet->name_trn_id = request_packet->name_trn_id;
 194         packet->ancount = 1;
 195         packet->operation =
 196                 NBT_FLAG_REPLY |
 197                 NBT_OPCODE_REGISTER |
 198                 NBT_FLAG_AUTHORITIVE |
 199                 NBT_FLAG_RECURSION_DESIRED |
 200                 NBT_FLAG_RECURSION_AVAIL |
 201                 NBT_RCODE_ACT;
 202
 203         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 204         if (packet->answers == NULL) goto failed;
 205
 206         packet->answers[0].name     = *name;
 207         packet->answers[0].rr_type  = NBT_QTYPE_NETBIOS;
 208         packet->answers[0].rr_class = NBT_QCLASS_IP;
 209         packet->answers[0].ttl      = 0;
 210         packet->answers[0].rdata    = request_packet->additional[0].rdata;
 211
 212         DEBUG(7,("Sending negative name registration reply for %s to %s:%d\n",
 213                  nbt_name_string(packet, name), src_address, src_port));
 214
 215         nbt_name_reply_send(nbtsock, src_address, src_port, packet);
 216
 217 failed:
 218         talloc_free(packet);
 219 }