/* Unix SMB/CIFS implementation. core wins server handling Copyright (C) Andrew Tridgell 2005 Copyright (C) Stefan Metzmacher 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/wins/winsdb.h" #include "nbt_server/wins/winsserver.h" #include "system/time.h" #include "libcli/composite/composite.h" #include "smbd/service_task.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->config.max_renew_interval); ttl = MAX(ttl, winssrv->config.min_renew_interval); return ttl; } static enum wrepl_name_type wrepl_type(uint16_t nb_flags, struct nbt_name *name, BOOL mhomed) { /* this copes with the nasty hack that is the type 0x1c name */ if (name->type == NBT_NAME_LOGON) { return WREPL_TYPE_SGROUP; } if (nb_flags & NBT_NM_GROUP) { return WREPL_TYPE_GROUP; } if (mhomed) { return WREPL_TYPE_MHOMED; } return WREPL_TYPE_UNIQUE; } /* register a new name with WINS */ static uint8_t wins_register_new(struct nbt_name_socket *nbtsock, struct nbt_name_packet *packet, const struct nbt_peer_socket *src, enum wrepl_name_type type) { 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; enum wrepl_name_node node; #define WREPL_NODE_NBT_FLAGS(nb_flags) \ ((nb_flags & NBT_NM_OWNER_TYPE)>>13) node = WREPL_NODE_NBT_FLAGS(nb_flags); rec.name = name; rec.type = type; rec.state = WREPL_STATE_ACTIVE; rec.node = node; rec.is_static = False; rec.expire_time = time(NULL) + ttl; rec.version = 0; /* will be allocated later */ rec.wins_owner = NULL; /* will be set later */ rec.registered_by = src->addr; rec.addresses = winsdb_addr_list_make(packet); if (rec.addresses == NULL) return NBT_RCODE_SVR; rec.addresses = winsdb_addr_list_add(rec.addresses, address, winssrv->wins_db->local_owner, rec.expire_time); 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]->address)); return winsdb_add(winssrv->wins_db, &rec, WINSDB_FLAG_ALLOC_VERSION | WINSDB_FLAG_TAKE_OWNERSHIP); } /* 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, struct winsdb_addr *winsdb_addr, const struct nbt_peer_socket *src) { 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; uint32_t modify_flags = 0; rec->expire_time = time(NULL) + ttl; rec->registered_by = src->addr; if (winsdb_addr) { winsdb_addr->wins_owner = winssrv->wins_db->local_owner; winsdb_addr->expire_time = rec->expire_time; } if (strcmp(winssrv->wins_db->local_owner, rec->wins_owner) != 0) { modify_flags = WINSDB_FLAG_ALLOC_VERSION | WINSDB_FLAG_TAKE_OWNERSHIP; } DEBUG(5,("WINS: refreshed registration of %s at %s\n", nbt_name_string(packet, rec->name), address)); return winsdb_modify(winssrv->wins_db, rec, modify_flags); } /* do a sgroup merge */ static uint8_t wins_sgroup_merge(struct nbt_name_socket *nbtsock, struct nbt_name_packet *packet, struct winsdb_record *rec, const char *address, const struct nbt_peer_socket *src) { 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); rec->expire_time = time(NULL) + ttl; rec->registered_by = src->addr; rec->addresses = winsdb_addr_list_add(rec->addresses, address, winssrv->wins_db->local_owner, rec->expire_time); if (rec->addresses == NULL) return NBT_RCODE_SVR; DEBUG(5,("WINS: sgroup merge of %s at %s\n", nbt_name_string(packet, rec->name), address)); return winsdb_modify(winssrv->wins_db, rec, WINSDB_FLAG_ALLOC_VERSION | WINSDB_FLAG_TAKE_OWNERSHIP); } struct wack_state { struct wins_server *winssrv; struct nbt_name_socket *nbtsock; struct nbt_name_packet *request_packet; struct winsdb_record *rec; struct nbt_peer_socket src; const char *reg_address; enum wrepl_name_type new_type; struct wins_challenge_io io; NTSTATUS status; }; /* deny a registration request */ static void wins_wack_deny(struct wack_state *s) { nbtd_name_registration_reply(s->nbtsock, s->request_packet, &s->src, NBT_RCODE_ACT); DEBUG(4,("WINS: denied name registration request for %s from %s:%d\n", nbt_name_string(s, s->rec->name), s->src.addr, s->src.port)); talloc_free(s); } /* allow a registration request */ static void wins_wack_allow(struct wack_state *s) { NTSTATUS status; uint32_t ttl = wins_server_ttl(s->winssrv, s->request_packet->additional[0].ttl); struct winsdb_record *rec = s->rec, *rec2; uint32_t i,j; status = winsdb_lookup(s->winssrv->wins_db, rec->name, s, &rec2); if (!NT_STATUS_IS_OK(status) || rec2->version != rec->version || strcmp(rec2->wins_owner, rec->wins_owner) != 0) { DEBUG(1,("WINS: record %s changed during WACK - failing registration\n", nbt_name_string(s, rec->name))); wins_wack_deny(s); return; } /* * if the old name owner doesn't hold the name anymore * handle the request as new registration for the new name owner */ if (!NT_STATUS_IS_OK(s->status)) { uint8_t rcode; winsdb_delete(s->winssrv->wins_db, rec); rcode = wins_register_new(s->nbtsock, s->request_packet, &s->src, s->new_type); if (rcode != NBT_RCODE_OK) { DEBUG(1,("WINS: record %s failed to register as new during WACK\n", nbt_name_string(s, rec->name))); wins_wack_deny(s); return; } goto done; } rec->expire_time = time(NULL) + ttl; rec->registered_by = s->src.addr; /* * now remove all addresses that're the client doesn't hold anymore * and update the time stamp and owner for the ownes that are still there */ for (i=0; rec->addresses[i]; i++) { BOOL found = False; for (j=0; j < s->io.out.num_addresses; j++) { if (strcmp(rec->addresses[i]->address, s->io.out.addresses[j]) != 0) continue; found = True; break; } if (found) { rec->addresses[i]->wins_owner = s->winssrv->wins_db->local_owner; rec->addresses[i]->expire_time = rec->expire_time; continue; } winsdb_addr_list_remove(rec->addresses, rec->addresses[i]->address); } rec->addresses = winsdb_addr_list_add(rec->addresses, s->reg_address, s->winssrv->wins_db->local_owner, rec->expire_time); if (rec->addresses == NULL) goto failed; /* if we have more than one address, this becomes implicit a MHOMED record */ if (winsdb_addr_list_length(rec->addresses) > 1) { rec->type = WREPL_TYPE_MHOMED; } winsdb_modify(s->winssrv->wins_db, rec, WINSDB_FLAG_ALLOC_VERSION | WINSDB_FLAG_TAKE_OWNERSHIP); DEBUG(4,("WINS: accepted registration of %s with address %s\n", nbt_name_string(s, rec->name), s->reg_address)); done: nbtd_name_registration_reply(s->nbtsock, s->request_packet, &s->src, NBT_RCODE_OK); failed: talloc_free(s); } /* called when a name query to a current owner completes */ static void wack_wins_challenge_handler(struct composite_context *c_req) { struct wack_state *s = talloc_get_type(c_req->async.private_data, struct wack_state); BOOL found; uint32_t i; s->status = wins_challenge_recv(c_req, s, &s->io); /* * if the owner denies it holds the name, then allow * the registration */ if (!NT_STATUS_IS_OK(s->status)) { wins_wack_allow(s); return; } if (s->new_type == WREPL_TYPE_GROUP || s->new_type == WREPL_TYPE_SGROUP) { DEBUG(1,("WINS: record %s failed to register as group type(%u) during WACK, it's still type(%u)\n", nbt_name_string(s, s->rec->name), s->new_type, s->rec->type)); wins_wack_deny(s); return; } /* * if the owner still wants the name and doesn't reply * with the address trying to be registered, then deny * the registration */ found = False; for (i=0; i < s->io.out.num_addresses; i++) { if (strcmp(s->reg_address, s->io.out.addresses[i]) != 0) continue; found = True; break; } if (!found) { wins_wack_deny(s); return; } wins_wack_allow(s); return; } /* a client has asked to register a unique name that someone else owns. We need to ask each of the current owners if they still want it. If they do then reject the registration, otherwise allow it */ static void wins_register_wack(struct nbt_name_socket *nbtsock, struct nbt_name_packet *packet, struct winsdb_record *rec, const struct nbt_peer_socket *src, enum wrepl_name_type new_type) { struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private, struct nbtd_interface); struct wins_server *winssrv = iface->nbtsrv->winssrv; struct wack_state *s; struct composite_context *c_req; uint32_t ttl; s = talloc_zero(nbtsock, struct wack_state); if (s == NULL) goto failed; /* package up the state variables for this wack request */ s->winssrv = winssrv; s->nbtsock = nbtsock; s->request_packet = talloc_steal(s, packet); s->rec = talloc_steal(s, rec); s->reg_address = packet->additional[0].rdata.netbios.addresses[0].ipaddr; s->new_type = new_type; s->src.port = src->port; s->src.addr = talloc_strdup(s, src->addr); if (s->src.addr == NULL) goto failed; s->io.in.nbtd_server = iface->nbtsrv; s->io.in.event_ctx = iface->nbtsrv->task->event_ctx; s->io.in.name = rec->name; s->io.in.num_addresses = winsdb_addr_list_length(rec->addresses); s->io.in.addresses = winsdb_addr_string_list(s, rec->addresses); if (s->io.in.addresses == NULL) goto failed; /* * send a WACK to the client, specifying the maximum time it could * take to check with the owner, plus some slack */ ttl = 5 + 4 * winsdb_addr_list_length(rec->addresses); nbtd_wack_reply(nbtsock, packet, src, ttl); /* * send the challenge to the old addresses */ c_req = wins_challenge_send(s, &s->io); if (c_req == NULL) goto failed; c_req->async.fn = wack_wins_challenge_handler; c_req->async.private_data = s; return; failed: talloc_free(s); nbtd_name_registration_reply(nbtsock, packet, src, NBT_RCODE_SVR); } /* register a name */ static void nbtd_winsserver_register(struct nbt_name_socket *nbtsock, struct nbt_name_packet *packet, const struct nbt_peer_socket *src) { NTSTATUS status; 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; BOOL mhomed = ((packet->operation & NBT_OPCODE) == NBT_OPCODE_MULTI_HOME_REG); enum wrepl_name_type new_type = wrepl_type(nb_flags, name, mhomed); struct winsdb_addr *winsdb_addr = NULL; /* * as a special case, the local master browser name is always accepted * for registration, but never stored, but w2k3 stores it if it's registered * as a group name, (but a query for the 0x1D name still returns not found!) */ if (name->type == NBT_NAME_MASTER && !(nb_flags & NBT_NM_GROUP)) { rcode = NBT_RCODE_OK; goto done; } /* w2k3 refuses 0x1B names with marked as group */ if (name->type == NBT_NAME_PDC && (nb_flags & NBT_NM_GROUP)) { rcode = NBT_RCODE_RFS; goto done; } /* w2k3 refuses 0x1C names with out marked as group */ if (name->type == NBT_NAME_LOGON && !(nb_flags & NBT_NM_GROUP)) { rcode = NBT_RCODE_RFS; goto done; } /* w2k3 refuses 0x1E names with out marked as group */ if (name->type == NBT_NAME_BROWSER && !(nb_flags & NBT_NM_GROUP)) { rcode = NBT_RCODE_RFS; goto done; } status = winsdb_lookup(winssrv->wins_db, name, packet, &rec); if (NT_STATUS_EQUAL(NT_STATUS_OBJECT_NAME_NOT_FOUND, status)) { rcode = wins_register_new(nbtsock, packet, src, new_type); goto done; } else if (!NT_STATUS_IS_OK(status)) { rcode = NBT_RCODE_SVR; goto done; } else if (rec->is_static) { if (rec->type == WREPL_TYPE_GROUP || rec->type == WREPL_TYPE_SGROUP) { rcode = NBT_RCODE_OK; goto done; } rcode = NBT_RCODE_ACT; goto done; } if (rec->type == WREPL_TYPE_GROUP) { if (new_type != WREPL_TYPE_GROUP) { DEBUG(2,("WINS: Attempt to register name %s as non normal group(%u)" " while a normal group is already there\n", nbt_name_string(packet, name), new_type)); rcode = NBT_RCODE_ACT; goto done; } if (rec->state == WREPL_STATE_ACTIVE) { /* TODO: is this correct? */ rcode = wins_update_ttl(nbtsock, packet, rec, NULL, src); goto done; } /* TODO: is this correct? */ winsdb_delete(winssrv->wins_db, rec); rcode = wins_register_new(nbtsock, packet, src, new_type); goto done; } if (rec->state != WREPL_STATE_ACTIVE) { winsdb_delete(winssrv->wins_db, rec); rcode = wins_register_new(nbtsock, packet, src, new_type); goto done; } switch (rec->type) { case WREPL_TYPE_UNIQUE: case WREPL_TYPE_MHOMED: /* * if its an active unique name, and the registration is for a group, then * see if the unique name owner still wants the name * TODO: is this correct? */ if (new_type == WREPL_TYPE_GROUP || new_type == WREPL_TYPE_GROUP) { wins_register_wack(nbtsock, packet, rec, src, new_type); return; } /* * if the registration is for an address that is currently active, then * just update the expiry time of the record and the address * TODO: is this correct? */ winsdb_addr = winsdb_addr_list_check(rec->addresses, address); if (winsdb_addr) { rcode = wins_update_ttl(nbtsock, packet, rec, winsdb_addr, src); 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, new_type); return; case WREPL_TYPE_GROUP: /* this should not be reached as normal groups are handled above */ DEBUG(0,("BUG at %s\n",__location__)); rcode = NBT_RCODE_ACT; goto done; case WREPL_TYPE_SGROUP: /* if the new record isn't also a special group, refuse the registration */ if (new_type != WREPL_TYPE_SGROUP) { DEBUG(2,("WINS: Attempt to register name %s as non special group(%u)" " while a special group is already there\n", nbt_name_string(packet, name), new_type)); rcode = NBT_RCODE_ACT; goto done; } /* * if the registration is for an address that is currently active, then * just update the expiry time * just update the expiry time of the record and the address * TODO: is this correct? */ winsdb_addr = winsdb_addr_list_check(rec->addresses, address); if (winsdb_addr) { rcode = wins_update_ttl(nbtsock, packet, rec, winsdb_addr, src); goto done; } rcode = wins_sgroup_merge(nbtsock, packet, rec, address, src); goto done; } done: nbtd_name_registration_reply(nbtsock, packet, src, rcode); } /* query a name */ static void nbtd_winsserver_query(struct nbt_name_socket *nbtsock, struct nbt_name_packet *packet, const struct nbt_peer_socket *src) { NTSTATUS status; 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; struct winsdb_record *rec_1b = NULL; const char **addresses; const char **addresses_1b = NULL; uint16_t nb_flags = 0; /* TODO: ... */ if (name->type == NBT_NAME_MASTER) { goto notfound; } /* * w2k3 returns the first address of the 0x1B record as first address * to a 0x1C query */ if (name->type == NBT_NAME_LOGON) { struct nbt_name name_1b; name_1b = *name; name_1b.type = NBT_NAME_PDC; status = winsdb_lookup(winssrv->wins_db, &name_1b, packet, &rec_1b); if (NT_STATUS_IS_OK(status)) { addresses_1b = winsdb_addr_string_list(packet, rec_1b->addresses); } } status = winsdb_lookup(winssrv->wins_db, name, packet, &rec); if (!NT_STATUS_IS_OK(status)) { goto notfound; } /* * for group's we always reply with * 255.255.255.255 as address, even if * the record is released or tombstoned */ if (rec->type == WREPL_TYPE_GROUP) { addresses = talloc_array(packet, const char *, 2); if (addresses == NULL) { nbtd_negative_name_query_reply(nbtsock, packet, src); return; } addresses[0] = "255.255.255.255"; addresses[1] = NULL; goto found; } if (rec->state != WREPL_STATE_ACTIVE) { goto notfound; } addresses = winsdb_addr_string_list(packet, rec->addresses); if (!addresses) { goto notfound; } /* * if addresses_1b isn't NULL, we have a 0x1C query and need to return the * first 0x1B address as first address */ if (addresses_1b && addresses_1b[0]) { const char **addresses_1c = addresses; uint32_t i; addresses = str_list_add(NULL, addresses_1b[0]); if (!addresses) { goto notfound; } talloc_steal(packet, addresses); for (i=0; addresses_1c[i]; i++) { if (strcmp(addresses_1b[0], addresses_1c[i]) == 0) continue; addresses = str_list_add(addresses, addresses_1c[i]); if (!addresses) { goto notfound; } } } found: nbtd_name_query_reply(nbtsock, packet, src, name, 0, nb_flags, addresses); return; notfound: nbtd_negative_name_query_reply(nbtsock, packet, src); } /* release a name */ static void nbtd_winsserver_release(struct nbt_name_socket *nbtsock, struct nbt_name_packet *packet, const struct nbt_peer_socket *src) { NTSTATUS status; 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; uint32_t modify_flags = 0; uint8_t ret; if (name->type == NBT_NAME_MASTER) { goto done; } status = winsdb_lookup(winssrv->wins_db, name, packet, &rec); if (!NT_STATUS_IS_OK(status)) { goto done; } if (rec->is_static) { if (rec->type == WREPL_TYPE_UNIQUE || rec->type == WREPL_TYPE_MHOMED) { goto done; } nbtd_name_release_reply(nbtsock, packet, src, NBT_RCODE_ACT); return; } if (rec->state != WREPL_STATE_ACTIVE) { goto done; } /* * TODO: do we need to check if * src->addr matches packet->additional[0].rdata.netbios.addresses[0].ipaddr * here? */ /* * we only allow releases from an owner - other releases are * silently ignored */ if (!winsdb_addr_list_check(rec->addresses, src->addr)) { goto done; } DEBUG(4,("WINS: released name %s from %s\n", nbt_name_string(rec, rec->name), src->addr)); switch (rec->type) { case WREPL_TYPE_UNIQUE: rec->state = WREPL_STATE_RELEASED; break; case WREPL_TYPE_GROUP: rec->state = WREPL_STATE_RELEASED; break; case WREPL_TYPE_SGROUP: winsdb_addr_list_remove(rec->addresses, src->addr); /* TODO: do we need to take the ownership here? */ if (winsdb_addr_list_length(rec->addresses) == 0) { rec->state = WREPL_STATE_RELEASED; } break; case WREPL_TYPE_MHOMED: winsdb_addr_list_remove(rec->addresses, src->addr); /* TODO: do we need to take the ownership here? */ if (winsdb_addr_list_length(rec->addresses) == 0) { rec->state = WREPL_STATE_RELEASED; } break; } if (rec->state == WREPL_STATE_RELEASED) { rec->expire_time = time(NULL) + winssrv->config.tombstone_interval; } ret = winsdb_modify(winssrv->wins_db, rec, modify_flags); if (ret != NBT_RCODE_OK) { DEBUG(1,("WINS: FAILED: released name %s at %s: error:%u\n", nbt_name_string(rec, rec->name), src->addr, ret)); } done: /* we match w2k3 by always giving a positive reply to name releases. */ nbtd_name_release_reply(nbtsock, packet, src, NBT_RCODE_OK); } /* answer a name query */ void nbtd_winsserver_request(struct nbt_name_socket *nbtsock, struct nbt_name_packet *packet, const struct nbt_peer_socket *src) { 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); 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); break; case NBT_OPCODE_RELEASE: nbtd_winsserver_release(nbtsock, packet, src); break; } } /* startup the WINS server, if configured */ NTSTATUS nbtd_winsserver_init(struct nbtd_server *nbtsrv) { uint32_t tombstone_interval; if (!lp_wins_support()) { nbtsrv->winssrv = NULL; return NT_STATUS_OK; } nbtsrv->winssrv = talloc_zero(nbtsrv, struct wins_server); NT_STATUS_HAVE_NO_MEMORY(nbtsrv->winssrv); nbtsrv->winssrv->config.max_renew_interval = lp_max_wins_ttl(); nbtsrv->winssrv->config.min_renew_interval = lp_min_wins_ttl(); tombstone_interval = lp_parm_int(-1,"wreplsrv","tombstone_interval", 6*24*60*60); nbtsrv->winssrv->config.tombstone_interval = tombstone_interval; nbtsrv->winssrv->wins_db = winsdb_connect(nbtsrv->winssrv); if (!nbtsrv->winssrv->wins_db) { return NT_STATUS_INTERNAL_DB_ERROR; } irpc_add_name(nbtsrv->task->msg_ctx, "wins_server"); return NT_STATUS_OK; }