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/*
* (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 <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>
#define DIR_BSC 1
#define DIR_MSC 2
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 LAC assigned to this connection */
unsigned int lac;
/* 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;
};
/**
* One BSC entry in the config
*/
struct bsc_config {
struct llist_head entry;
char *token;
unsigned int lac;
int nr;
struct bsc_nat *nat;
};
/**
* 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;
};
/* 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);
/**
* 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);
/**
* 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 bsc_connection *bsc, struct msgb *msg, struct bsc_nat_parsed *parsed);
void remove_sccp_src_ref(struct bsc_connection *bsc, struct msgb *msg, struct bsc_nat_parsed *parsed);
struct bsc_connection *patch_sccp_src_ref_to_bsc(struct msgb *, struct bsc_nat_parsed *, struct bsc_nat *);
struct bsc_connection *patch_sccp_src_ref_to_msc(struct msgb *, struct bsc_nat_parsed *, struct bsc_nat *);
#endif
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