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authorNeels Hofmeyr <neels@hofmeyr.de>2017-07-04 23:08:44 +0200
committerNeels Hofmeyr <neels@hofmeyr.de>2017-08-27 17:40:52 +0200
commited3157ce46cde0f3973a5ee0a0a53909f361ae7c (patch)
tree072f9b723003554bead716390f6ed8bf7351d103 /src/osmo-bsc_nat/bsc_sccp.c
parent2758330b6ab37ff30afca8306080f0e82ef5a732 (diff)
move openbsc/* to repos root
This is the first step in creating this repository from the legacy openbsc.git. Like all other Osmocom repositories, keep the autoconf and automake files in the repository root. openbsc.git has been the sole exception, which ends now. Change-Id: I9c6f2a448d9cb1cc088cf1cf6918b69d7e69b4e7
Diffstat (limited to 'src/osmo-bsc_nat/bsc_sccp.c')
-rw-r--r--src/osmo-bsc_nat/bsc_sccp.c247
1 files changed, 247 insertions, 0 deletions
diff --git a/src/osmo-bsc_nat/bsc_sccp.c b/src/osmo-bsc_nat/bsc_sccp.c
new file mode 100644
index 00000000..c6c265f7
--- /dev/null
+++ b/src/osmo-bsc_nat/bsc_sccp.c
@@ -0,0 +1,247 @@
+/* SCCP patching and handling routines */
+/*
+ * (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 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
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * 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/>.
+ *
+ */
+
+#include <openbsc/debug.h>
+#include <openbsc/bsc_nat.h>
+#include <openbsc/bsc_nat_sccp.h>
+
+#include <osmocom/sccp/sccp.h>
+
+#include <osmocom/core/talloc.h>
+
+#include <string.h>
+#include <time.h>
+
+static int equal(struct sccp_source_reference *ref1, struct sccp_source_reference *ref2)
+{
+ return memcmp(ref1, ref2, sizeof(*ref1)) == 0;
+}
+
+/*
+ * SCCP patching below
+ */
+
+/* check if we are using this ref for patched already */
+static int sccp_ref_is_free(struct sccp_source_reference *ref, struct bsc_nat *nat)
+{
+ struct nat_sccp_connection *conn;
+
+ llist_for_each_entry(conn, &nat->sccp_connections, list_entry) {
+ if (equal(ref, &conn->patched_ref))
+ return -1;
+ }
+
+ return 0;
+}
+
+/* copied from sccp.c */
+static int assign_src_local_reference(struct sccp_source_reference *ref, struct bsc_nat *nat)
+{
+ static uint32_t last_ref = 0x50000;
+ int wrapped = 0;
+
+ do {
+ struct sccp_source_reference reference;
+ reference.octet1 = (last_ref >> 0) & 0xff;
+ reference.octet2 = (last_ref >> 8) & 0xff;
+ reference.octet3 = (last_ref >> 16) & 0xff;
+
+ ++last_ref;
+ /* do not use the reversed word and wrap around */
+ if ((last_ref & 0x00FFFFFF) == 0x00FFFFFF) {
+ LOGP(DNAT, LOGL_NOTICE, "Wrapped searching for a free code\n");
+ last_ref = 0;
+ ++wrapped;
+ }
+
+ if (sccp_ref_is_free(&reference, nat) == 0) {
+ *ref = reference;
+ return 0;
+ }
+ } while (wrapped != 2);
+
+ LOGP(DNAT, LOGL_ERROR, "Finding a free reference failed\n");
+ return -1;
+}
+
+struct nat_sccp_connection *create_sccp_src_ref(struct bsc_connection *bsc,
+ struct bsc_nat_parsed *parsed)
+{
+ struct nat_sccp_connection *conn;
+
+ /* Some commercial BSCs like to reassign there SRC ref */
+ llist_for_each_entry(conn, &bsc->nat->sccp_connections, list_entry) {
+ if (conn->bsc != bsc)
+ continue;
+ if (!equal(parsed->src_local_ref, &conn->real_ref))
+ continue;
+
+ /* the BSC has reassigned the SRC ref and we failed to keep track */
+ memset(&conn->remote_ref, 0, sizeof(conn->remote_ref));
+ if (assign_src_local_reference(&conn->patched_ref, bsc->nat) != 0) {
+ LOGP(DNAT, LOGL_ERROR, "BSC %d reused src ref: %d and we failed to generate a new id.\n",
+ bsc->cfg->nr, sccp_src_ref_to_int(parsed->src_local_ref));
+ bsc_mgcp_dlcx(conn);
+ llist_del(&conn->list_entry);
+ talloc_free(conn);
+ return NULL;
+ } else {
+ clock_gettime(CLOCK_MONOTONIC, &conn->creation_time);
+ bsc_mgcp_dlcx(conn);
+ return conn;
+ }
+ }
+
+
+ conn = talloc_zero(bsc->nat, struct nat_sccp_connection);
+ if (!conn) {
+ LOGP(DNAT, LOGL_ERROR, "Memory allocation failure.\n");
+ return NULL;
+ }
+
+ conn->bsc = bsc;
+ clock_gettime(CLOCK_MONOTONIC, &conn->creation_time);
+ conn->real_ref = *parsed->src_local_ref;
+ if (assign_src_local_reference(&conn->patched_ref, bsc->nat) != 0) {
+ LOGP(DNAT, LOGL_ERROR, "Failed to assign a ref.\n");
+ talloc_free(conn);
+ return NULL;
+ }
+
+ bsc_mgcp_init(conn);
+ llist_add_tail(&conn->list_entry, &bsc->nat->sccp_connections);
+ rate_ctr_inc(&bsc->cfg->stats.ctrg->ctr[BCFG_CTR_SCCP_CONN]);
+ osmo_counter_inc(bsc->cfg->nat->stats.sccp.conn);
+
+ LOGP(DNAT, LOGL_DEBUG, "Created 0x%x <-> 0x%x mapping for con %p\n",
+ sccp_src_ref_to_int(&conn->real_ref),
+ sccp_src_ref_to_int(&conn->patched_ref), bsc);
+
+ return conn;
+}
+
+int update_sccp_src_ref(struct nat_sccp_connection *sccp, struct bsc_nat_parsed *parsed)
+{
+ if (!parsed->dest_local_ref || !parsed->src_local_ref) {
+ LOGP(DNAT, LOGL_ERROR, "CC MSG should contain both local and dest address.\n");
+ return -1;
+ }
+
+ sccp->remote_ref = *parsed->src_local_ref;
+ sccp->has_remote_ref = 1;
+ LOGP(DNAT, LOGL_DEBUG, "Updating 0x%x to remote 0x%x on %p\n",
+ sccp_src_ref_to_int(&sccp->patched_ref),
+ sccp_src_ref_to_int(&sccp->remote_ref), sccp->bsc);
+
+ return 0;
+}
+
+void remove_sccp_src_ref(struct bsc_connection *bsc, struct msgb *msg, struct bsc_nat_parsed *parsed)
+{
+ struct nat_sccp_connection *conn;
+
+ llist_for_each_entry(conn, &bsc->nat->sccp_connections, list_entry) {
+ if (equal(parsed->src_local_ref, &conn->patched_ref)) {
+ sccp_connection_destroy(conn);
+ return;
+ }
+ }
+
+ LOGP(DNAT, LOGL_ERROR, "Can not remove connection: 0x%x\n",
+ sccp_src_ref_to_int(parsed->src_local_ref));
+}
+
+/*
+ * We have a message from the MSC to the BSC. The MSC is using
+ * an address that was assigned by the MUX, we need to update the
+ * dest reference to the real network.
+ */
+struct nat_sccp_connection *patch_sccp_src_ref_to_bsc(struct msgb *msg,
+ struct bsc_nat_parsed *parsed,
+ struct bsc_nat *nat)
+{
+ struct nat_sccp_connection *conn;
+
+ if (!parsed->dest_local_ref) {
+ LOGP(DNAT, LOGL_ERROR, "MSG should contain dest_local_ref.\n");
+ return NULL;
+ }
+
+
+ llist_for_each_entry(conn, &nat->sccp_connections, list_entry) {
+ if (!equal(parsed->dest_local_ref, &conn->patched_ref))
+ continue;
+
+ /* Change the dest address to the real one */
+ *parsed->dest_local_ref = conn->real_ref;
+ return conn;
+ }
+
+ return NULL;
+}
+
+/*
+ * These are message to the MSC. We will need to find the BSC
+ * Connection by either the SRC or the DST local reference.
+ *
+ * In case of a CR we need to work by the SRC local reference
+ * in all other cases we need to work by the destination local
+ * reference..
+ */
+struct nat_sccp_connection *patch_sccp_src_ref_to_msc(struct msgb *msg,
+ struct bsc_nat_parsed *parsed,
+ struct bsc_connection *bsc)
+{
+ struct nat_sccp_connection *conn;
+
+ llist_for_each_entry(conn, &bsc->nat->sccp_connections, list_entry) {
+ if (conn->bsc != bsc)
+ continue;
+
+ if (parsed->src_local_ref) {
+ if (equal(parsed->src_local_ref, &conn->real_ref)) {
+ *parsed->src_local_ref = conn->patched_ref;
+ return conn;
+ }
+ } else if (parsed->dest_local_ref) {
+ if (equal(parsed->dest_local_ref, &conn->remote_ref))
+ return conn;
+ } else {
+ LOGP(DNAT, LOGL_ERROR, "Header has neither loc/dst ref.\n");
+ return NULL;
+ }
+ }
+
+ return NULL;
+}
+
+struct nat_sccp_connection *bsc_nat_find_con_by_bsc(struct bsc_nat *nat,
+ struct sccp_source_reference *ref)
+{
+ struct nat_sccp_connection *conn;
+
+ llist_for_each_entry(conn, &nat->sccp_connections, list_entry) {
+ if (equal(ref, &conn->real_ref))
+ return conn;
+ }
+
+ return NULL;
+}