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/*
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);
}
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