diff options
Diffstat (limited to 'openbsc/include/openbsc/bsc_nat.h')
| -rw-r--r-- | openbsc/include/openbsc/bsc_nat.h | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/openbsc/include/openbsc/bsc_nat.h b/openbsc/include/openbsc/bsc_nat.h new file mode 100644 index 000000000..64c6b8656 --- /dev/null +++ b/openbsc/include/openbsc/bsc_nat.h @@ -0,0 +1,274 @@ +/* + * (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. + * + */ + +#ifndef BSC_NAT_H +#define BSC_NAT_H + +#include "mgcp.h" + +#include <sys/types.h> +#include <sccp/sccp_types.h> + +#include <osmocore/select.h> +#include <osmocore/msgb.h> +#include <osmocore/timer.h> +#include <osmocore/write_queue.h> +#include <osmocore/statistics.h> + +#include <regex.h> + +#define DIR_BSC 1 +#define DIR_MSC 2 + +#define NAT_IPAC_PROTO_MGCP 0xfc + +struct bsc_nat; + +/* + * For the NAT we will need to analyze and later patch + * the received message. This would require us to parse + * the IPA and SCCP header twice. Instead of doing this + * we will have one analyze structure and have the patching + * and filter operate on the same structure. + */ +struct bsc_nat_parsed { + /* ip access prototype */ + int ipa_proto; + + /* source local reference */ + struct sccp_source_reference *src_local_ref; + + /* destination local reference */ + struct sccp_source_reference *dest_local_ref; + + /* called ssn number */ + int called_ssn; + + /* calling ssn number */ + int calling_ssn; + + /* sccp message type */ + int sccp_type; + + /* bssap type, e.g. 0 for BSS Management */ + int bssap; + + /* the gsm0808 message type */ + int gsm_type; +}; + +/* + * Per BSC data structure + */ +struct bsc_connection { + struct llist_head list_entry; + + /* do we know anything about this BSC? */ + int authenticated; + + /* the fd we use to communicate */ + struct write_queue write_queue; + + /* the BSS associated */ + struct bsc_config *cfg; + + /* a timeout node */ + struct timer_list id_timeout; + + /* a back pointer */ + struct bsc_nat *nat; +}; + +/* + * Per SCCP source local reference patch table. It needs to + * be updated on new SCCP connections, connection confirm and reject, + * and on the loss of the BSC connection. + */ +struct sccp_connections { + struct llist_head list_entry; + + struct bsc_connection *bsc; + + struct sccp_source_reference real_ref; + struct sccp_source_reference patched_ref; + struct sccp_source_reference remote_ref; + + /* GSM audio handling. That is 32 * multiplex + ts */ + int msc_timeslot; + int bsc_timeslot; +}; + +/** + * Stats per BSC + */ +struct bsc_config_stats { + struct { + struct counter *conn; + struct counter *calls; + } sccp; + + struct { + struct counter *reconn; + } net; +}; + +/** + * One BSC entry in the config + */ +struct bsc_config { + struct llist_head entry; + + char *token; + unsigned int lac; + int nr; + + /* imsi white and blacklist */ + char *imsi_allow; + regex_t imsi_allow_re; + char *imsi_deny; + regex_t imsi_deny_re; + + /* backpointer */ + struct bsc_nat *nat; + + struct bsc_config_stats stats; +}; + +/** + * BSCs point of view of endpoints + */ +struct bsc_endpoint { + /* the pending transaction id */ + char *transaction_id; + /* the bsc we are talking to */ + struct bsc_connection *bsc; + /* pending delete */ + int pending_delete; +}; + +/** + * Statistic for the nat. + */ +struct bsc_nat_statistics { + struct { + struct counter *conn; + struct counter *calls; + } sccp; + + struct { + struct counter *reconn; + struct counter *auth_fail; + } bsc; + + struct { + struct counter *reconn; + } msc; +}; + +/** + * the structure of the "nat" network + */ +struct bsc_nat { + /* active SCCP connections that need patching */ + struct llist_head sccp_connections; + + /* active BSC connections that need patching */ + struct llist_head bsc_connections; + + /* known BSC's */ + struct llist_head bsc_configs; + int num_bsc; + + /* MGCP config */ + struct mgcp_config *mgcp_cfg; + struct write_queue mgcp_queue; + u_int8_t mgcp_msg[4096]; + int mgcp_length; + + /* msc things */ + char *msc_ip; + int msc_port; + int first_contact; + + struct bsc_endpoint *bsc_endpoints; + + /* filter */ + char *imsi_allow; + regex_t imsi_allow_re; + char *imsi_deny; + regex_t imsi_deny_re; + + /* statistics */ + struct bsc_nat_statistics stats; +}; + +/* create and init the structures */ +struct bsc_config *bsc_config_alloc(struct bsc_nat *nat, const char *token, unsigned int lac); +struct bsc_config *bsc_config_num(struct bsc_nat *nat, int num); +struct bsc_nat *bsc_nat_alloc(void); +struct bsc_connection *bsc_connection_alloc(struct bsc_nat *nat); +void bsc_nat_set_msc_ip(struct bsc_nat *bsc, const char *ip); + +void sccp_connection_destroy(struct sccp_connections *); + +/** + * parse the given message into the above structure + */ +struct bsc_nat_parsed *bsc_nat_parse(struct msgb *msg); + +/** + * filter based on IP Access header in both directions + */ +int bsc_nat_filter_ipa(int direction, struct msgb *msg, struct bsc_nat_parsed *parsed); +int bsc_nat_vty_init(struct bsc_nat *nat); +struct bsc_connection *bsc_nat_find_bsc(struct bsc_nat *nat, struct msgb *msg, int *_lac); + +/** + * SCCP patching and handling + */ +int create_sccp_src_ref(struct bsc_connection *bsc, struct msgb *msg, struct bsc_nat_parsed *parsed); +int update_sccp_src_ref(struct sccp_connections *sccp, struct bsc_nat_parsed *parsed); +void remove_sccp_src_ref(struct bsc_connection *bsc, struct msgb *msg, struct bsc_nat_parsed *parsed); +struct sccp_connections *patch_sccp_src_ref_to_bsc(struct msgb *, struct bsc_nat_parsed *, struct bsc_nat *); +struct sccp_connections *patch_sccp_src_ref_to_msc(struct msgb *, struct bsc_nat_parsed *, struct bsc_nat *); + +/** + * MGCP/Audio handling + */ +int bsc_write_mgcp(struct bsc_connection *bsc, const u_int8_t *data, unsigned int length); +int bsc_mgcp_assign(struct sccp_connections *, struct msgb *msg); +void bsc_mgcp_clear(struct sccp_connections *); +void bsc_mgcp_free_endpoint(struct bsc_nat *nat, int); +void bsc_mgcp_free_endpoints(struct bsc_nat *nat); +int bsc_mgcp_init(struct bsc_nat *nat); + +struct sccp_connections *bsc_mgcp_find_con(struct bsc_nat *, int endpoint_number); +struct msgb *bsc_mgcp_rewrite(char *input, int length, const char *ip, int port); +void bsc_mgcp_forward(struct bsc_connection *bsc, struct msgb *msg); + +void bsc_mgcp_clear_endpoints_for(struct bsc_connection *bsc); +int bsc_mgcp_parse_response(const char *str, int *code, char transaction[60]); +int bsc_mgcp_extract_ci(const char *resp); + + +int bsc_write(struct bsc_connection *bsc, struct msgb *msg, int id); + +#endif |