Osmocom's Base Station Controller for 2G mobile networks https://osmocom.org/projects/osmobsc
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* (C) 2010-2012 by Holger Hans Peter Freyther <zecke@selfish.org>
* (C) 2010-2012 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 Affero General Public License as published by
* the Free Software Foundation; either version 3 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
* GNU Affero General Public License for more details.
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
#ifndef BSC_NAT_H
#define BSC_NAT_H
#include "mgcp.h"
#include "bsc_msg_filter.h"
#include <osmocom/core/select.h>
#include <osmocom/core/msgb.h>
#include <osmocom/core/msgfile.h>
#include <osmocom/core/timer.h>
#include <osmocom/core/write_queue.h>
#include <osmocom/core/rate_ctr.h>
#include <osmocom/core/statistics.h>
#include <osmocom/gsm/protocol/gsm_04_08.h>
#include <regex.h>
#include <stdbool.h>
#define DIR_BSC 1
#define DIR_MSC 2
struct sccp_source_reference;
struct nat_sccp_connection;
struct bsc_nat_parsed;
struct bsc_nat;
struct bsc_nat_ussd_con;
struct nat_rewrite_rule;
* Is this terminated to the MSC, to the local machine (release
* handling for IMSI filtering) or to a USSD provider?
enum {
* Pending command entry
struct bsc_cmd_list {
struct llist_head list_entry;
struct osmo_timer_list timeout;
/* The NATed ID used on the bsc_con*/
int nat_id;
/* The control connection from which the command originated */
struct ctrl_connection *ccon;
/* The command from the control connection */
struct ctrl_cmd *cmd;
* Per BSC data structure
struct bsc_connection {
struct llist_head list_entry;
/* do we know anything about this BSC? */
int authenticated;
uint8_t last_rand[16];
/* the fd we use to communicate */
struct osmo_wqueue write_queue;
/* incoming message buffer */
struct msgb *pending_msg;
/* the BSS associated */
struct bsc_config *cfg;
/* a timeout node */
struct osmo_timer_list id_timeout;
/* pong timeout */
struct osmo_timer_list ping_timeout;
struct osmo_timer_list pong_timeout;
/* mgcp related code */
char *_endpoint_status;
int number_multiplexes;
int max_endpoints;
int last_endpoint;
int next_transaction;
uint32_t pending_dlcx_count;
struct llist_head pending_dlcx;
/* track the pending commands for this BSC */
struct llist_head cmd_pending;
int last_id;
/* a back pointer */
struct bsc_nat *nat;
* Stats per BSC
struct bsc_config_stats {
struct rate_ctr_group *ctrg;
enum bsc_cfg_ctr {
* One BSC entry in the config
struct bsc_config {
struct llist_head entry;
uint8_t key[16];
uint8_t key_present;
char *token;
int nr;
char *description;
/* imsi white and blacklist */
char *acc_lst_name;
int forbid_paging;
int paging_group;
/* audio handling */
int max_endpoints;
/* used internally for reload handling */
bool remove;
bool token_updated;
/* backpointer */
struct bsc_nat *nat;
struct bsc_config_stats stats;
struct llist_head lac_list;
/* Osmux is enabled/disabled per BSC */
int osmux;
struct bsc_lac_entry {
struct llist_head entry;
uint16_t lac;
struct bsc_nat_paging_group {
struct llist_head entry;
/* list of lac entries */
struct llist_head lists;
int nr;
* BSCs point of view of endpoints
struct bsc_endpoint {
/* the operation that is carried out */
int transaction_state;
/* the pending transaction id */
char *transaction_id;
/* the bsc we are talking to */
struct bsc_connection *bsc;
* Statistic for the nat.
struct bsc_nat_statistics {
struct {
struct osmo_counter *conn;
struct osmo_counter *calls;
} sccp;
struct {
struct osmo_counter *reconn;
struct osmo_counter *auth_fail;
} bsc;
struct {
struct osmo_counter *reconn;
} msc;
struct {
struct osmo_counter *reconn;
} ussd;
* 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;
/* access lists */
struct llist_head access_lists;
/* paging groups */
struct llist_head paging_groups;
/* known BSC's */
struct llist_head bsc_configs;
int num_bsc;
int bsc_ip_dscp;
/* MGCP config */
struct mgcp_config *mgcp_cfg;
uint8_t mgcp_msg[4096];
int mgcp_length;
int mgcp_ipa;
int sdp_ensure_amr_mode_set;
/* msc things */
struct llist_head dests;
struct bsc_msc_dest *main_dest;
struct bsc_msc_connection *msc_con;
char *token;
/* timeouts */
int auth_timeout;
int ping_timeout;
int pong_timeout;
struct bsc_endpoint *bsc_endpoints;
/* path to file with BSC config */
char *include_file;
char *include_base;
char *resolved_path;
/* filter */
char *acc_lst_name;
/* Barring of subscribers with a rb tree */
struct rb_root imsi_black_list;
char *imsi_black_list_fn;
/* number rewriting */
char *num_rewr_name;
struct llist_head num_rewr;
char *num_rewr_post_name;
struct llist_head num_rewr_post;
char *smsc_rewr_name;
struct llist_head smsc_rewr;
char *tpdest_match_name;
struct llist_head tpdest_match;
char *sms_clear_tp_srr_name;
struct llist_head sms_clear_tp_srr;
char *sms_num_rewr_name;
struct llist_head sms_num_rewr;
/* more rewriting */
char *num_rewr_trie_name;
struct nat_rewrite *num_rewr_trie;
/* USSD messages we want to match */
char *ussd_lst_name;
char *ussd_query;
regex_t ussd_query_re;
char *ussd_token;
char *ussd_local;
struct osmo_fd ussd_listen;
struct bsc_nat_ussd_con *ussd_con;
/* for maintainenance */
int blocked;
/* statistics */
struct bsc_nat_statistics stats;
/* control interface */
struct ctrl_handle *ctrl;
struct bsc_nat_ussd_con {
struct osmo_wqueue queue;
struct bsc_nat *nat;
int authorized;
struct msgb *pending_msg;
struct osmo_timer_list auth_timeout;
/* create and init the structures */
struct bsc_config *bsc_config_alloc(struct bsc_nat *nat, const char *token,
unsigned int number);
struct bsc_config *bsc_config_num(struct bsc_nat *nat, int num);
struct bsc_config *bsc_config_by_token(struct bsc_nat *nat, const char *token, int len);
void bsc_config_free(struct bsc_config *);
void bsc_config_add_lac(struct bsc_config *cfg, int lac);
void bsc_config_del_lac(struct bsc_config *cfg, int lac);
int bsc_config_handles_lac(struct bsc_config *cfg, int lac);
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 nat_sccp_connection *);
void bsc_close_connection(struct bsc_connection *);
const char *bsc_con_type_to_string(int type);
* 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);
int bsc_nat_find_paging(struct msgb *msg, const uint8_t **,int *len);
* SCCP patching and handling
struct nat_sccp_connection *create_sccp_src_ref(struct bsc_connection *bsc, struct bsc_nat_parsed *parsed);
int update_sccp_src_ref(struct nat_sccp_connection *sccp, struct bsc_nat_parsed *parsed);
void remove_sccp_src_ref(struct bsc_connection *bsc, struct msgb *msg, struct bsc_nat_parsed *parsed);
struct nat_sccp_connection *patch_sccp_src_ref_to_bsc(struct msgb *, struct bsc_nat_parsed *, struct bsc_nat *);
struct nat_sccp_connection *patch_sccp_src_ref_to_msc(struct msgb *, struct bsc_nat_parsed *, struct bsc_connection *);
struct nat_sccp_connection *bsc_nat_find_con_by_bsc(struct bsc_nat *, struct sccp_source_reference *);
* MGCP/Audio handling
int bsc_mgcp_nr_multiplexes(int max_endpoints);
int bsc_write_mgcp(struct bsc_connection *bsc, const uint8_t *data, unsigned int length);
int bsc_mgcp_assign_patch(struct nat_sccp_connection *, struct msgb *msg);
void bsc_mgcp_init(struct nat_sccp_connection *);
void bsc_mgcp_dlcx(struct nat_sccp_connection *);
void bsc_mgcp_free_endpoints(struct bsc_nat *nat);
int bsc_mgcp_nat_init(struct bsc_nat *nat);
struct nat_sccp_connection *bsc_mgcp_find_con(struct bsc_nat *, int endpoint_number);
struct msgb *bsc_mgcp_rewrite(char *input, int length, int endp, const char *ip,
int port, int osmux, int *first_payload_type, int mode_set);
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]);
uint32_t bsc_mgcp_extract_ci(const char *resp);
int bsc_write(struct bsc_connection *bsc, struct msgb *msg, int id);
int bsc_do_write(struct osmo_wqueue *queue, struct msgb *msg, int id);
int bsc_write_msg(struct osmo_wqueue *queue, struct msgb *msg);
int bsc_write_cb(struct osmo_fd *bfd, struct msgb *msg);
int bsc_nat_msc_is_connected(struct bsc_nat *nat);
int bsc_conn_type_to_ctr(struct nat_sccp_connection *conn);
struct gsm48_hdr *bsc_unpack_dtap(struct bsc_nat_parsed *parsed, struct msgb *msg, uint32_t *len);
/** USSD filtering */
int bsc_ussd_init(struct bsc_nat *nat);
int bsc_ussd_check(struct nat_sccp_connection *con, struct bsc_nat_parsed *parsed, struct msgb *msg);
int bsc_ussd_close_connections(struct bsc_nat *nat);
struct msgb *bsc_nat_rewrite_msg(struct bsc_nat *nat, struct msgb *msg, struct bsc_nat_parsed *, const char *imsi);
/** paging group handling */
struct bsc_nat_paging_group *bsc_nat_paging_group_num(struct bsc_nat *nat, int group);
struct bsc_nat_paging_group *bsc_nat_paging_group_create(struct bsc_nat *nat, int group);
void bsc_nat_paging_group_delete(struct bsc_nat_paging_group *);
void bsc_nat_paging_group_add_lac(struct bsc_nat_paging_group *grp, int lac);
void bsc_nat_paging_group_del_lac(struct bsc_nat_paging_group *grp, int lac);
* Number rewriting support below
struct bsc_nat_num_rewr_entry {
struct llist_head list;
regex_t msisdn_reg;
regex_t num_reg;
char *replace;
uint8_t is_prefix_lookup;
void bsc_nat_num_rewr_entry_adapt(void *ctx, struct llist_head *head, const struct osmo_config_list *);
void bsc_nat_send_mgcp_to_msc(struct bsc_nat *bsc_nat, struct msgb *msg);
void bsc_nat_handle_mgcp(struct bsc_nat *bsc, struct msgb *msg);
struct ctrl_handle *bsc_nat_controlif_setup(struct bsc_nat *nat,
const char *bind_addr, int port);
void bsc_nat_ctrl_del_pending(struct bsc_cmd_list *pending);
int bsc_nat_handle_ctrlif_msg(struct bsc_connection *bsc, struct msgb *msg);
int bsc_nat_extract_lac(struct bsc_connection *bsc, struct nat_sccp_connection *con,
struct bsc_nat_parsed *parsed, struct msgb *msg);
int bsc_nat_filter_sccp_cr(struct bsc_connection *bsc, struct msgb *msg,
struct bsc_nat_parsed *, int *con_type, char **imsi,
struct bsc_filter_reject_cause *cause);
int bsc_nat_filter_dt(struct bsc_connection *bsc, struct msgb *msg,
struct nat_sccp_connection *con, struct bsc_nat_parsed *parsed,
struct bsc_filter_reject_cause *cause);
* CTRL interface helper
void bsc_nat_inform_reject(struct bsc_connection *bsc, const char *imsi);
* Use for testing
void bsc_nat_free(struct bsc_nat *nat);