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;
mgcp: add voice muxer support This patch adds the voice muxer. You can use this to batch RTP traffic to reduce bandwidth comsuption. Basically, osmux transforms RTP flows to a compact batch format, that is later on decompacted to its original form. Port UDP/1984 is used for the muxer traffic between osmo-bsc_nat and osmo-bsc_mgcp (in the BSC side). This feature depends on libosmo-netif, which contains the osmux core support. Osmux is requested on-demand via the MGCP CRCX/MDCX messages (using the vendor-specific extension X-Osmux: on) coming from the BSC-NAT, so you can selectively enable osmux per BSC from one the bsc-nat.cfg file, so we have a centralized point to enable/disable osmux. First thing you need to do is to accept requests to use Osmux, this can be done from VTY interface of osmo-bsc_nat and osmo-bsc_mgcp by adding the following line: mgcp ... osmux on osmux batch-factor 4 This just initializes the osmux engine. You still have to specify what BSC uses osmux from osmo-bsc_nat configuration file: ... bsc 1 osmux on bsc 2 ... bsc 3 osmux on In this case, bsc 1 and 3 should use osmux if possible, bsc 2 does not have osmux enabled. Thus, you can selectively enable osmux depending on the BSC, and we have a centralized point for configuration from the bsc-nat to enable osmux on demand, as suggested by Holger. At this moment, this patch contains heavy debug logging for each RTP packet that can be removed later to save cycles. The RTP ssrc/seqnum/timestamp is randomly allocated for each MDCX that is received to configure an endpoint.
9 years ago
/* 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);