152 lines
4.0 KiB
C
152 lines
4.0 KiB
C
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/* SCCP patching and handling routines */
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/*
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* (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org>
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* (C) 2010 by On-Waves
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* All Rights Reserved
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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*/
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#include <openbsc/debug.h>
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#include <openbsc/bsc_nat.h>
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#include <osmocore/talloc.h>
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#include <string.h>
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/*
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* SCCP patching below
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*/
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/* check if we are using this ref for patched already */
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static int sccp_ref_is_free(struct sccp_source_reference *ref, struct bsc_nat *nat)
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{
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struct sccp_connections *conn;
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llist_for_each_entry(conn, &nat->sccp_connections, list_entry) {
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if (memcmp(ref, &conn->patched_ref, sizeof(*ref)) == 0)
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return -1;
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}
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return 0;
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}
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/* copied from sccp.c */
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static int assign_src_local_reference(struct sccp_source_reference *ref, struct bsc_nat *nat)
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{
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static u_int32_t last_ref = 0x50000;
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int wrapped = 0;
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do {
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struct sccp_source_reference reference;
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reference.octet1 = (last_ref >> 0) & 0xff;
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reference.octet2 = (last_ref >> 8) & 0xff;
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reference.octet3 = (last_ref >> 16) & 0xff;
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++last_ref;
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/* do not use the reversed word and wrap around */
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if ((last_ref & 0x00FFFFFF) == 0x00FFFFFF) {
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LOGP(DNAT, LOGL_NOTICE, "Wrapped searching for a free code\n");
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last_ref = 0;
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++wrapped;
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}
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if (sccp_ref_is_free(&reference, nat) == 0) {
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*ref = reference;
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return 0;
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}
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} while (wrapped != 2);
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LOGP(DNAT, LOGL_ERROR, "Finding a free reference failed\n");
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return -1;
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}
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int create_sccp_src_ref(struct bsc_connection *bsc, struct msgb *msg, struct bsc_nat_parsed *parsed)
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{
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struct sccp_connections *conn;
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conn = talloc_zero(bsc->nat, struct sccp_connections);
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if (!conn) {
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LOGP(DNAT, LOGL_ERROR, "Memory allocation failure.\n");
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return -1;
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}
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conn->real_ref = *parsed->src_local_ref;
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if (assign_src_local_reference(&conn->patched_ref, bsc->nat) != 0) {
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LOGP(DNAT, LOGL_ERROR, "Failed to assign a ref.\n");
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talloc_free(conn);
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return -1;
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}
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return 0;
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}
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void remove_sccp_src_ref(struct bsc_connection *bsc, struct msgb *msg, struct bsc_nat_parsed *parsed)
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{
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struct sccp_connections *conn;
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llist_for_each_entry(conn, &bsc->nat->sccp_connections, list_entry) {
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if (memcmp(parsed->src_local_ref,
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&conn->real_ref, sizeof(conn->real_ref)) == 0) {
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if (bsc != conn->bsc) {
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LOGP(DNAT, LOGL_ERROR, "Someone else...\n");
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continue;
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}
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llist_del(&conn->list_entry);
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talloc_free(conn);
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return;
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}
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}
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LOGP(DNAT, LOGL_ERROR, "Unknown connection.\n");
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}
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struct bsc_connection *patch_sccp_src_ref_to_bsc(struct msgb *msg,
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struct bsc_nat_parsed *parsed,
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struct bsc_nat *nat)
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{
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struct sccp_connections *conn;
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llist_for_each_entry(conn, &nat->sccp_connections, list_entry) {
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if (memcmp(parsed->dest_local_ref,
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&conn->real_ref, sizeof(*parsed->dest_local_ref)) == 0) {
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memcpy(parsed->dest_local_ref,
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&conn->patched_ref, sizeof(*parsed->dest_local_ref));
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return conn->bsc;
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}
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}
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return NULL;
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}
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struct bsc_connection *patch_sccp_src_ref_to_msc(struct msgb *msg,
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struct bsc_nat_parsed *parsed,
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struct bsc_nat *nat)
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{
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struct sccp_connections *conn;
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llist_for_each_entry(conn, &nat->sccp_connections, list_entry) {
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if (memcmp(parsed->src_local_ref,
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&conn->real_ref, sizeof(*parsed->src_local_ref)) == 0) {
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memcpy(parsed->src_local_ref,
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&conn->patched_ref, sizeof(*parsed->src_local_ref));
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return conn->bsc;
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}
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}
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return NULL;
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}
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