| |
| /* 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; |
| } |