diff options
Diffstat (limited to 'openbsc/src/nat/bsc_nat_utils.c')
| -rw-r--r-- | openbsc/src/nat/bsc_nat_utils.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/openbsc/src/nat/bsc_nat_utils.c b/openbsc/src/nat/bsc_nat_utils.c new file mode 100644 index 000000000..24b4e1f00 --- /dev/null +++ b/openbsc/src/nat/bsc_nat_utils.c @@ -0,0 +1,165 @@ + +/* 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 <openbsc/ipaccess.h> + +#include <osmocore/linuxlist.h> +#include <osmocore/talloc.h> + +#include <sccp/sccp.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; +} + +void sccp_connection_destroy(struct sccp_connections *conn) +{ + LOGP(DNAT, LOGL_DEBUG, "Destroy 0x%x <-> 0x%x mapping for con %p\n", + sccp_src_ref_to_int(&conn->real_ref), + sccp_src_ref_to_int(&conn->patched_ref), conn->bsc); + bsc_mgcp_clear(conn); + llist_del(&conn->list_entry); + talloc_free(conn); +} + +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: %d\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->cfg) + continue; + if (!bsc->authenticated || _lac != bsc->cfg->lac) + continue; + + return bsc; + } + } + + return NULL; +} + +int bsc_write_mgcp(struct bsc_connection *bsc, const u_int8_t *data, unsigned int length) +{ + struct msgb *msg; + + if (length > 4096 - 128) { + LOGP(DINP, LOGL_ERROR, "Can not send message of that size.\n"); + return -1; + } + + msg = msgb_alloc_headroom(4096, 128, "to-bsc"); + if (!msg) { + LOGP(DINP, LOGL_ERROR, "Failed to allocate memory for BSC msg.\n"); + return -1; + } + + /* copy the data */ + msg->l3h = msgb_put(msg, length); + memcpy(msg->l3h, data, length); + + return bsc_write_mgcp_msg(bsc, msg); +} + +int bsc_write_mgcp_msg(struct bsc_connection *bsc, struct msgb *msg) +{ + /* prepend the header */ + ipaccess_prepend_header(msg, NAT_IPAC_PROTO_MGCP); + + if (write_queue_enqueue(&bsc->write_queue, msg) != 0) { + LOGP(DINP, LOGL_ERROR, "Failed to enqueue the write.\n"); + msgb_free(msg); + return -1; + } + + return 0; +} + |