/* Unix SMB/CIFS implementation. core wins server handling Copyright (C) Andrew Tridgell 2005 This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include "includes.h" #include "nbt_server/nbt_server.h" #include "nbt_server/winsdb.h" #include "system/time.h" /* work out the ttl we will use given a client requested ttl */ uint32_t wins_server_ttl(struct wins_server *winssrv, uint32_t ttl) { ttl = MIN(ttl, winssrv->max_ttl); ttl = MAX(ttl, winssrv->min_ttl); return ttl; } /* register a new name with WINS */ static uint8_t wins_register_new(struct nbt_name_socket *nbtsock, struct nbt_name_packet *packet, const char *src_address, int src_port) { struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private, struct nbtd_interface); struct wins_server *winssrv = iface->nbtsrv->winssrv; struct nbt_name *name = &packet->questions[0].name; uint32_t ttl = wins_server_ttl(winssrv, packet->additional[0].ttl); uint16_t nb_flags = packet->additional[0].rdata.netbios.addresses[0].nb_flags; const char *address = packet->additional[0].rdata.netbios.addresses[0].ipaddr; struct winsdb_record rec; rec.name = name; rec.nb_flags = nb_flags; rec.state = WINS_REC_ACTIVE; rec.expire_time = time(NULL) + ttl; rec.registered_by = src_address; if (IS_GROUP_NAME(name, nb_flags)) { rec.addresses = str_list_make(packet, "255.255.255.255", NULL); } else { rec.addresses = str_list_make(packet, address, NULL); } if (rec.addresses == NULL) return NBT_RCODE_SVR; DEBUG(4,("WINS: accepted registration of %s with address %s\n", nbt_name_string(packet, name), rec.addresses[0])); return winsdb_add(winssrv, &rec); } /* update the ttl on an existing record */ static uint8_t wins_update_ttl(struct nbt_name_socket *nbtsock, struct nbt_name_packet *packet, struct winsdb_record *rec, const char *src_address, int src_port) { struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private, struct nbtd_interface); struct wins_server *winssrv = iface->nbtsrv->winssrv; uint32_t ttl = wins_server_ttl(winssrv, packet->additional[0].ttl); const char *address = packet->additional[0].rdata.netbios.addresses[0].ipaddr; time_t now = time(NULL); if (now + ttl > rec->expire_time) { rec->expire_time = now + ttl; } rec->registered_by = src_address; DEBUG(5,("WINS: refreshed registration of %s at %s\n", nbt_name_string(packet, rec->name), address)); return winsdb_modify(winssrv, rec); } /* register a name */ static void nbtd_winsserver_register(struct nbt_name_socket *nbtsock, struct nbt_name_packet *packet, const char *src_address, int src_port) { struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private, struct nbtd_interface); struct wins_server *winssrv = iface->nbtsrv->winssrv; struct nbt_name *name = &packet->questions[0].name; struct winsdb_record *rec; uint8_t rcode = NBT_RCODE_OK; uint16_t nb_flags = packet->additional[0].rdata.netbios.addresses[0].nb_flags; const char *address = packet->additional[0].rdata.netbios.addresses[0].ipaddr; /* as a special case, the local master browser name is always accepted for registration, but never stored */ if (name->type == NBT_NAME_MASTER) { goto done; } rec = winsdb_load(winssrv, name, packet); if (rec == NULL) { rcode = wins_register_new(nbtsock, packet, src_address, src_port); goto done; } else if (rec->state != WINS_REC_ACTIVE) { winsdb_delete(winssrv, rec); rcode = wins_register_new(nbtsock, packet, src_address, src_port); goto done; } /* its an active name - first see if the registration is of the right type */ if ((rec->nb_flags & NBT_NM_GROUP) && !(nb_flags & NBT_NM_GROUP)) { DEBUG(2,("WINS: Attempt to register unique name %s when group name is active\n", nbt_name_string(packet, name))); rcode = NBT_RCODE_ACT; goto done; } /* if its an active unique name, and the registration is for a group, then see if the unique name owner still wants the name */ if (!(rec->nb_flags & NBT_NM_GROUP) && (nb_flags & NBT_NM_GROUP)) { wins_register_wack(nbtsock, packet, rec, src_address, src_port); return; } /* if the registration is for a group, then just update the expiry time and we are done */ if (IS_GROUP_NAME(name, nb_flags)) { wins_update_ttl(nbtsock, packet, rec, src_address, src_port); goto done; } /* if the registration is for an address that is currently active, then just update the expiry time */ if (str_list_check(rec->addresses, address)) { wins_update_ttl(nbtsock, packet, rec, src_address, src_port); goto done; } /* we have to do a WACK to see if the current owner is willing to give up its claim */ wins_register_wack(nbtsock, packet, rec, src_address, src_port); return; done: nbtd_name_registration_reply(nbtsock, packet, src_address, src_port, rcode); } /* query a name */ static void nbtd_winsserver_query(struct nbt_name_socket *nbtsock, struct nbt_name_packet *packet, const char *src_address, int src_port) { struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private, struct nbtd_interface); struct wins_server *winssrv = iface->nbtsrv->winssrv; struct nbt_name *name = &packet->questions[0].name; struct winsdb_record *rec; rec = winsdb_load(winssrv, name, packet); if (rec == NULL || rec->state != WINS_REC_ACTIVE) { nbtd_negative_name_query_reply(nbtsock, packet, src_address, src_port); return; } nbtd_name_query_reply(nbtsock, packet, src_address, src_port, name, 0, rec->nb_flags, rec->addresses); } /* release a name */ static void nbtd_winsserver_release(struct nbt_name_socket *nbtsock, struct nbt_name_packet *packet, const char *src_address, int src_port) { struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private, struct nbtd_interface); struct wins_server *winssrv = iface->nbtsrv->winssrv; struct nbt_name *name = &packet->questions[0].name; struct winsdb_record *rec; rec = winsdb_load(winssrv, name, packet); if (rec == NULL || rec->state != WINS_REC_ACTIVE || IS_GROUP_NAME(name, rec->nb_flags)) { goto done; } /* we only allow releases from an owner - other releases are silently ignored */ if (str_list_check(rec->addresses, src_address)) { const char *address = packet->additional[0].rdata.netbios.addresses[0].ipaddr; DEBUG(4,("WINS: released name %s at %s\n", nbt_name_string(rec, rec->name), address)); str_list_remove(rec->addresses, address); if (rec->addresses[0] == NULL) { rec->state = WINS_REC_RELEASED; } winsdb_modify(winssrv, rec); } done: /* we match w2k3 by always giving a positive reply to name releases. */ nbtd_name_release_reply(nbtsock, packet, src_address, src_port, NBT_RCODE_OK); } /* answer a name query */ void nbtd_winsserver_request(struct nbt_name_socket *nbtsock, struct nbt_name_packet *packet, const char *src_address, int src_port) { struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private, struct nbtd_interface); struct wins_server *winssrv = iface->nbtsrv->winssrv; if ((packet->operation & NBT_FLAG_BROADCAST) || winssrv == NULL) { return; } switch (packet->operation & NBT_OPCODE) { case NBT_OPCODE_QUERY: nbtd_winsserver_query(nbtsock, packet, src_address, src_port); break; case NBT_OPCODE_REGISTER: case NBT_OPCODE_REFRESH: case NBT_OPCODE_REFRESH2: case NBT_OPCODE_MULTI_HOME_REG: nbtd_winsserver_register(nbtsock, packet, src_address, src_port); break; case NBT_OPCODE_RELEASE: nbtd_winsserver_release(nbtsock, packet, src_address, src_port); break; } } /* startup the WINS server, if configured */ NTSTATUS nbtd_winsserver_init(struct nbtd_server *nbtsrv) { if (!lp_wins_support()) { nbtsrv->winssrv = NULL; return NT_STATUS_OK; } nbtsrv->winssrv = talloc(nbtsrv, struct wins_server); NT_STATUS_HAVE_NO_MEMORY(nbtsrv->winssrv); nbtsrv->winssrv->max_ttl = lp_max_wins_ttl(); nbtsrv->winssrv->min_ttl = lp_min_wins_ttl(); return winsdb_init(nbtsrv->winssrv); }