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/* BSC Multiplexer/NAT Utilities */
/*
* (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org>
* (C) 2010 by On-Waves
* All Rights Reserved
*
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#include <openbsc/bsc_nat.h>
#include <openbsc/gsm_data.h>
#include <openbsc/bssap.h>
#include <openbsc/debug.h>
#include <osmocore/linuxlist.h>
#include <osmocore/talloc.h>
#include <netinet/in.h>
#include <arpa/inet.h>
struct bsc_nat *bsc_nat_alloc(void)
{
struct bsc_nat *nat = talloc_zero(tall_bsc_ctx, struct bsc_nat);
if (!nat)
return NULL;
INIT_LLIST_HEAD(&nat->sccp_connections);
INIT_LLIST_HEAD(&nat->bsc_connections);
INIT_LLIST_HEAD(&nat->bsc_configs);
return nat;
}
struct bsc_connection *bsc_connection_alloc(struct bsc_nat *nat)
{
struct bsc_connection *con = talloc_zero(nat, struct bsc_connection);
if (!con)
return NULL;
con->nat = nat;
return con;
}
struct bsc_config *bsc_config_alloc(struct bsc_nat *nat, const char *token, unsigned int lac)
{
struct bsc_config *conf = talloc_zero(nat, struct bsc_config);
if (!conf)
return NULL;
conf->token = talloc_strdup(conf, token);
conf->lac = lac;
conf->nr = nat->num_bsc;
conf->nat = nat;
llist_add(&conf->entry, &nat->bsc_configs);
++nat->num_bsc;
return conf;
}
struct bsc_connection *bsc_nat_find_bsc(struct bsc_nat *nat, struct msgb *msg)
{
struct bsc_connection *bsc;
int data_length;
const u_int8_t *data;
struct tlv_parsed tp;
int i = 0;
if (!msg->l3h || msgb_l3len(msg) < 3) {
LOGP(DNAT, LOGL_ERROR, "Paging message is too short.\n");
return NULL;
}
tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l3h + 3, msgb_l3len(msg) - 3, 0, 0);
if (!TLVP_PRESENT(&tp, GSM0808_IE_CELL_IDENTIFIER_LIST)) {
LOGP(DNAT, LOGL_ERROR, "No CellIdentifier List inside paging msg.\n");
return NULL;
}
data_length = TLVP_LEN(&tp, GSM0808_IE_CELL_IDENTIFIER_LIST);
data = TLVP_VAL(&tp, GSM0808_IE_CELL_IDENTIFIER_LIST);
if (data[0] != CELL_IDENT_LAC) {
LOGP(DNAT, LOGL_ERROR, "Unhandled cell ident discrminator: %c\n", data[0]);
return NULL;
}
/* Currently we only handle one BSC */
for (i = 1; i < data_length - 1; i += 2) {
unsigned int _lac = ntohs(*(unsigned int *) &data[i]);
llist_for_each_entry(bsc, &nat->bsc_connections, list_entry) {
if (!bsc->authenticated || _lac != bsc->lac)
continue;
return bsc;
}
}
return NULL;
}
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