Change in ...osmo-bsc[master]: Re-introduce support for IPA-encapsulated MGCP

laforge gerrit-no-reply at lists.osmocom.org
Tue Jun 18 18:09:26 UTC 2019


laforge has submitted this change and it was merged. ( https://gerrit.osmocom.org/c/osmo-bsc/+/9342 )

Change subject: Re-introduce support for IPA-encapsulated MGCP
......................................................................

Re-introduce support for IPA-encapsulated MGCP

Old osmo-bsc-sccplite already supported this, but in the migration
over to libosmo-sigtran and to real 3GPP AoIP, this functionality
got lost.

We now create a UDP proxy socket. Any MGCP commands received via IPA
from MSC (or rather: bsc_nat) are retransmitted to the MGW via UDP on
this socket.  Any responses back from the MGW received on the UDP
socket are retransmitted back to MSC/bsc_nat as MGCP inside the IPA
multiplex.

Closes: OS#2536
Change-Id: I38ad8fa645c08900e0e1f1b4b96136bc6d96b3ab
---
M include/osmocom/bsc/bsc_msc_data.h
M include/osmocom/bsc/osmo_bsc_sigtran.h
M src/osmo-bsc/Makefile.am
M src/osmo-bsc/osmo_bsc_ctrl.c
A src/osmo-bsc/osmo_bsc_mgcp.c
M src/osmo-bsc/osmo_bsc_msc.c
M src/osmo-bsc/osmo_bsc_sigtran.c
M tests/handover/Makefile.am
8 files changed, 207 insertions(+), 20 deletions(-)

Approvals:
  laforge: Looks good to me, approved
  Jenkins Builder: Verified



diff --git a/include/osmocom/bsc/bsc_msc_data.h b/include/osmocom/bsc/bsc_msc_data.h
index 1f9872a..2ad7c68 100644
--- a/include/osmocom/bsc/bsc_msc_data.h
+++ b/include/osmocom/bsc/bsc_msc_data.h
@@ -33,6 +33,7 @@
 #include "osmux.h"
 
 #include <osmocom/core/timer.h>
+#include <osmocom/core/select.h>
 #include <osmocom/gsm/protocol/gsm_04_08.h>
 
 
@@ -135,6 +136,16 @@
 	enum osmux_usage use_osmux;
 	/* Whether we detected the MSC supports Osmux (during BSSMAP_RESET) */
 	bool remote_supports_osmux;
+
+	/* Proxy between IPA/SCCPlite encapsulated MGCP and UDP */
+	struct {
+		/* local (BSC) IP address to be used */
+		char *local_addr;
+		/* local (BSC) UDP port to be used to talk with MGW */
+		uint16_t local_port;
+		/* UDP socket for proxying MGCP via SCCPlite/IPA */
+		struct osmo_fd ofd;
+	} mgcp_ipa;
 };
 
 /*
diff --git a/include/osmocom/bsc/osmo_bsc_sigtran.h b/include/osmocom/bsc/osmo_bsc_sigtran.h
index bd8b063..b934d51 100644
--- a/include/osmocom/bsc/osmo_bsc_sigtran.h
+++ b/include/osmocom/bsc/osmo_bsc_sigtran.h
@@ -44,3 +44,12 @@
 
 /* receive + process a CTRL command from the piggy-back on the IPA/SCCPlite link */
 int bsc_sccplite_rx_ctrl(struct osmo_ss7_asp *asp, struct msgb *msg);
+
+/* receive + process a MGCP message from the piggy-back on the IPA/SCCPlite link */
+int bsc_sccplite_rx_mgcp(struct osmo_ss7_asp *asp, struct msgb *msg);
+
+/* send a message via SCCPLite to given MSC */
+int bsc_sccplite_msc_send(struct bsc_msc_data *msc, struct msgb *msg);
+
+/* we received some data on the UDP proxy socket from the MGW. Pass it to MSC via IPA */
+int bsc_sccplite_mgcp_proxy_cb(struct osmo_fd *ofd, unsigned int what);
diff --git a/src/osmo-bsc/Makefile.am b/src/osmo-bsc/Makefile.am
index e88e614..d50515b 100644
--- a/src/osmo-bsc/Makefile.am
+++ b/src/osmo-bsc/Makefile.am
@@ -78,6 +78,7 @@
 	osmo_bsc_grace.c \
 	osmo_bsc_lcls.c \
 	osmo_bsc_main.c \
+	osmo_bsc_mgcp.c \
 	osmo_bsc_msc.c \
 	osmo_bsc_sigtran.c \
 	osmo_bsc_vty.c \
diff --git a/src/osmo-bsc/osmo_bsc_ctrl.c b/src/osmo-bsc/osmo_bsc_ctrl.c
index 80699f8..afe061e 100644
--- a/src/osmo-bsc/osmo_bsc_ctrl.c
+++ b/src/osmo-bsc/osmo_bsc_ctrl.c
@@ -52,6 +52,39 @@
 	return rt->dest.as;
 }
 
+static int _ss7_as_send(struct osmo_ss7_as *as, struct msgb *msg)
+{
+	struct osmo_ss7_asp *asp;
+	unsigned int i;
+
+	/* FIXME: unify with xua_as_transmit_msg() and perform proper ASP lookup */
+	for (i = 0; i < ARRAY_SIZE(as->cfg.asps); i++) {
+		asp = as->cfg.asps[i];
+		if (!asp)
+			continue;
+		/* FIXME: deal with multiple ASPs per AS */
+		return osmo_ss7_asp_send(asp, msg);
+	}
+	msgb_free(msg);
+	return -1;
+}
+
+int bsc_sccplite_msc_send(struct bsc_msc_data *msc, struct msgb *msg)
+{
+	struct osmo_ss7_as *as;
+
+	as = msc_get_ss7_as(msc);
+	if (!as) {
+		msgb_free(msg);
+		return -1;
+	}
+
+	/* don't attempt to send CTRL on a non-SCCPlite AS */
+	if (as->cfg.proto != OSMO_SS7_ASP_PROT_IPA)
+		return 0;
+
+	return _ss7_as_send(as, msg);
+}
 
 /* Encode a CTRL command and send it to the given ASP
  * \param[in] asp ASP through which we shall send the encoded message
@@ -83,30 +116,20 @@
  * Caller must hence free 'cmd' itself. */
 static int sccplite_msc_ctrl_cmd_send(struct bsc_msc_data *msc, struct ctrl_cmd *cmd)
 {
-	struct osmo_ss7_as *as;
-	struct osmo_ss7_asp *asp;
-	unsigned int i;
+	struct msgb *msg;
 
-	as = msc_get_ss7_as(msc);
-	if (!as)
+	msg = ctrl_cmd_make(cmd);
+	if (!msg)
 		return -1;
 
-	/* don't attempt to send CTRL on a non-SCCPlite AS */
-	if (as->cfg.proto != OSMO_SS7_ASP_PROT_IPA)
-		return 0;
+	ipa_prepend_header_ext(msg, IPAC_PROTO_EXT_CTRL);
+	ipa_prepend_header(msg, IPAC_PROTO_OSMO);
 
-	/* FIXME: unify with xua_as_transmit_msg() and perform proper ASP lookup */
-	for (i = 0; i < ARRAY_SIZE(as->cfg.asps); i++) {
-		asp = as->cfg.asps[i];
-		if (!asp)
-			continue;
-		/* FIXME: deal with multiple ASPs per AS */
-		return sccplite_asp_ctrl_cmd_send(asp, cmd);
-	}
-	return -1;
+	return bsc_sccplite_msc_send(msc, msg);
 }
 
-/* receive + process a CTRL command from the piggy-back on the IPA/SCCPlite link */
+/* receive + process a CTRL command from the piggy-back on the IPA/SCCPlite link.
+ * Transfers msg ownership. */
 int bsc_sccplite_rx_ctrl(struct osmo_ss7_asp *asp, struct msgb *msg)
 {
 	struct ctrl_cmd *cmd;
diff --git a/src/osmo-bsc/osmo_bsc_mgcp.c b/src/osmo-bsc/osmo_bsc_mgcp.c
new file mode 100644
index 0000000..bec7930
--- /dev/null
+++ b/src/osmo-bsc/osmo_bsc_mgcp.c
@@ -0,0 +1,92 @@
+/*
+ * SCCPlite MGCP handling
+ *
+ * (C) 2018 by Harald Welte <laforge at gnumonks.org>
+ * 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 <osmocom/bsc/bsc_msc_data.h>
+#include <osmocom/bsc/osmo_bsc.h>
+#include <osmocom/bsc/gsm_data.h>
+#include <osmocom/bsc/debug.h>
+#include <osmocom/gsm/ipa.h>
+#include <osmocom/gsm/protocol/ipaccess.h>
+#include <osmocom/bsc/osmo_bsc_sigtran.h>
+
+#include <arpa/inet.h>
+
+/* Determine MSC based on the ASP over which the message was received */
+static struct bsc_msc_data *msc_from_asp(struct osmo_ss7_asp *asp)
+{
+	int msc_nr;
+	/* this is rather ugly, as we of course have MTP-level routing between
+	 * the local SCCP user (BSC) and the AS/ASPs.  However, for the most simple
+	 * SCCPlite case, there is a 1:1 mapping between ASP and AS, and using
+	 * the libosmo-sigtran "simple client", the names are "as[p]-clnt-msc-%u",
+	 * as set in osmo_bsc_sigtran_init() */
+	if (sscanf(asp->cfg.name, "asp-clnt-msc-%u", &msc_nr) != 1) {
+		LOGP(DMSC, LOGL_ERROR, "Cannot find to which MSC the ASP %s belongs\n", asp->cfg.name);
+		return NULL;
+	}
+	return osmo_msc_data_find(bsc_gsmnet, msc_nr);
+}
+
+/* We received an IPA-encapsulated MGCP message from a MSC. Transfers msg ownership. */
+int bsc_sccplite_rx_mgcp(struct osmo_ss7_asp *asp, struct msgb *msg)
+{
+	struct bsc_msc_data *msc;
+	int rc;
+
+	LOGP(DMSC, LOGL_NOTICE, "%s: Received IPA-encapsulated MGCP: %s\n", asp->cfg.name, msg->l2h);
+	msc = msc_from_asp(asp);
+	if (msc) {
+		/* we don't have a write queue here as we simply expect the socket buffers
+		 * to be large enough to deal with whatever small/infrequent MGCP messages */
+		rc = send(msc->mgcp_ipa.ofd.fd, msgb_l2(msg), msgb_l2len(msg), 0);
+	} else
+		rc = 0;
+
+	msgb_free(msg);
+	return rc;
+}
+
+/* we received some data on the UDP proxy socket from the MGW. Pass it to MSC via IPA */
+int bsc_sccplite_mgcp_proxy_cb(struct osmo_fd *ofd, unsigned int what)
+{
+	struct bsc_msc_data *msc = ofd->data;
+	struct msgb *msg;
+	int rc;
+
+	if (!(what & BSC_FD_READ))
+		return 0;
+
+	msg = msgb_alloc_headroom(1024, 16, "MGCP->IPA");
+	OSMO_ASSERT(msg);
+	rc = recv(ofd->fd, msg->data, msgb_tailroom(msg), 0);
+	if (rc <= 0) {
+		LOGP(DMSC, LOGL_ERROR, "error receiving data from MGCP<->IPA proxy UDP socket: "
+			"%s\n", strerror(errno));
+		msgb_free(msg);
+		return rc;
+	}
+	msg->l2h = msgb_put(msg, rc);
+	msg->l2h[rc] = '\0';
+	LOGP(DMSC, LOGL_NOTICE, "Received MGCP on UDP proxy socket: %s\n", msg->l2h);
+
+	ipa_prepend_header(msg, IPAC_PROTO_MGCP_OLD);
+	return bsc_sccplite_msc_send(msc, msg);
+}
diff --git a/src/osmo-bsc/osmo_bsc_msc.c b/src/osmo-bsc/osmo_bsc_msc.c
index 6a6b1a9..7e78d94 100644
--- a/src/osmo-bsc/osmo_bsc_msc.c
+++ b/src/osmo-bsc/osmo_bsc_msc.c
@@ -27,26 +27,49 @@
 #include <osmocom/bsc/gsm_data.h>
 #include <osmocom/bsc/ipaccess.h>
 #include <osmocom/bsc/bsc_msc_data.h>
+#include <osmocom/bsc/osmo_bsc_sigtran.h>
 #include <osmocom/bsc/signal.h>
 
 #include <osmocom/core/talloc.h>
+#include <osmocom/core/socket.h>
 
 #include <osmocom/gsm/gsm0808.h>
 
 #include <osmocom/abis/ipa.h>
 
+#include <osmocom/mgcp_client/mgcp_client.h>
+
 #include <sys/socket.h>
 #include <netinet/tcp.h>
 #include <unistd.h>
 
-int osmo_bsc_msc_init(struct bsc_msc_data *data)
+int osmo_bsc_msc_init(struct bsc_msc_data *msc)
 {
+	struct gsm_network *net = msc->network;
+	uint16_t mgw_port;
+	int rc;
+
 	/* FIXME: This is a leftover from the old architecture that used
 	 * sccp-lite with osmocom specific authentication. Since we now
 	 * changed to AoIP the connected status and the authentication
 	 * status is managed differently. However osmo_bsc_filter.c still
 	 * needs the flags to be set to one. See also: OS#3112 */
-	data->is_authenticated = 1;
+	msc->is_authenticated = 1;
+
+	if (net->mgw.conf->remote_port >= 0)
+		mgw_port = net->mgw.conf->remote_port;
+	else
+		mgw_port = MGCP_CLIENT_REMOTE_PORT_DEFAULT;
+
+	rc = osmo_sock_init2_ofd(&msc->mgcp_ipa.ofd, AF_INET, SOCK_DGRAM, IPPROTO_UDP,
+				 msc->mgcp_ipa.local_addr, msc->mgcp_ipa.local_port,
+				 net->mgw.conf->remote_addr, mgw_port,
+				 OSMO_SOCK_F_BIND | OSMO_SOCK_F_CONNECT);
+	if (rc < 0) {
+		LOGP(DMSC, LOGL_ERROR, "msc %u: Could not create/connect/bind MGCP proxy socket: %d\n",
+			msc->nr, rc);
+		return rc;
+	}
 
 	return 0;
 }
@@ -117,6 +140,10 @@
 	msc_data->audio_support[4]->ver = 3;
 	msc_data->audio_support[4]->hr = 1;
 
+	osmo_fd_setup(&msc_data->mgcp_ipa.ofd, -1, BSC_FD_READ, &bsc_sccplite_mgcp_proxy_cb, msc_data, 0);
+	msc_data->mgcp_ipa.local_addr = talloc_strdup(msc_data, "0.0.0.0");
+	msc_data->mgcp_ipa.local_port = 0; /* dynamic */
+
 	return msc_data;
 }
 
diff --git a/src/osmo-bsc/osmo_bsc_sigtran.c b/src/osmo-bsc/osmo_bsc_sigtran.c
index 18f269d..763e1e1 100644
--- a/src/osmo-bsc/osmo_bsc_sigtran.c
+++ b/src/osmo-bsc/osmo_bsc_sigtran.c
@@ -611,8 +611,12 @@
 		switch (iph_ext->proto) {
 		case IPAC_PROTO_EXT_CTRL:
 			return bsc_sccplite_rx_ctrl(asp, msg);
+		case IPAC_PROTO_EXT_MGCP:
+			return bsc_sccplite_rx_mgcp(asp, msg);
 		}
 		break;
+	case IPAC_PROTO_MGCP_OLD:
+		return bsc_sccplite_rx_mgcp(asp, msg);
 	default:
 		break;
 	}
diff --git a/tests/handover/Makefile.am b/tests/handover/Makefile.am
index 56aea50..84c341e 100644
--- a/tests/handover/Makefile.am
+++ b/tests/handover/Makefile.am
@@ -8,6 +8,8 @@
 	-ggdb3 \
 	$(LIBOSMOCORE_CFLAGS) \
 	$(LIBOSMOGSM_CFLAGS) \
+	$(LIBOSMOCTRL_CFLAGS) \
+	$(LIBOSMOVTY_CFLAGS) \
 	$(LIBOSMOABIS_CFLAGS) \
 	$(LIBOSMOSIGTRAN_CFLAGS) \
 	$(LIBOSMOMGCPCLIENT_CFLAGS) \
@@ -38,15 +40,24 @@
 	$(NULL)
 
 handover_test_LDADD = \
+	$(top_builddir)/src/libfilter/bsc_msg_acc.o \
+	$(top_builddir)/src/libfilter/bsc_msg_vty.o \
 	$(top_builddir)/src/osmo-bsc/a_reset.o \
 	$(top_builddir)/src/osmo-bsc/abis_nm.o \
+	$(top_builddir)/src/osmo-bsc/abis_nm_vty.o \
+	$(top_builddir)/src/osmo-bsc/abis_om2000.o \
+	$(top_builddir)/src/osmo-bsc/abis_om2000_vty.o \
 	$(top_builddir)/src/osmo-bsc/abis_rsl.o \
+	$(top_builddir)/src/osmo-bsc/acc_ramp.o \
 	$(top_builddir)/src/osmo-bsc/arfcn_range_encode.o \
 	$(top_builddir)/src/osmo-bsc/assignment_fsm.o \
+	$(top_builddir)/src/osmo-bsc/bsc_ctrl_commands.o \
 	$(top_builddir)/src/osmo-bsc/bsc_init.o \
+	$(top_builddir)/src/osmo-bsc/bsc_rf_ctrl.o \
 	$(top_builddir)/src/osmo-bsc/bsc_rll.o \
 	$(top_builddir)/src/osmo-bsc/bsc_subscr_conn_fsm.o \
 	$(top_builddir)/src/osmo-bsc/bsc_subscriber.o \
+	$(top_builddir)/src/osmo-bsc/bsc_vty.o \
 	$(top_builddir)/src/osmo-bsc/bts_ipaccess_nanobts.o \
 	$(top_builddir)/src/osmo-bsc/bts_ipaccess_nanobts_omlattr.o \
 	$(top_builddir)/src/osmo-bsc/bts_sysmobts.o \
@@ -60,14 +71,20 @@
 	$(top_builddir)/src/osmo-bsc/handover_decision_2.o \
 	$(top_builddir)/src/osmo-bsc/handover_fsm.o \
 	$(top_builddir)/src/osmo-bsc/handover_logic.o \
+	$(top_builddir)/src/osmo-bsc/handover_vty.o \
 	$(top_builddir)/src/osmo-bsc/lchan_fsm.o \
 	$(top_builddir)/src/osmo-bsc/lchan_rtp_fsm.o \
 	$(top_builddir)/src/osmo-bsc/lchan_select.o \
+	$(top_builddir)/src/osmo-bsc/meas_feed.o \
 	$(top_builddir)/src/osmo-bsc/meas_rep.o \
 	$(top_builddir)/src/osmo-bsc/neighbor_ident.o \
+	$(top_builddir)/src/osmo-bsc/neighbor_ident_vty.o \
 	$(top_builddir)/src/osmo-bsc/net_init.o \
+	$(top_builddir)/src/osmo-bsc/osmo_bsc_ctrl.o \
 	$(top_builddir)/src/osmo-bsc/osmo_bsc_lcls.o \
+	$(top_builddir)/src/osmo-bsc/osmo_bsc_mgcp.o \
 	$(top_builddir)/src/osmo-bsc/osmo_bsc_msc.o \
+	$(top_builddir)/src/osmo-bsc/osmo_bsc_vty.o \
 	$(top_builddir)/src/osmo-bsc/paging.o \
 	$(top_builddir)/src/osmo-bsc/pcu_sock.o \
 	$(top_builddir)/src/osmo-bsc/penalty_timers.o \
@@ -76,6 +93,8 @@
 	$(top_builddir)/src/osmo-bsc/timeslot_fsm.o \
 	$(LIBOSMOCORE_LIBS) \
 	$(LIBOSMOGSM_LIBS) \
+	$(LIBOSMOCTRL_LIBS) \
+	$(LIBOSMOVTY_LIBS) \
 	$(LIBOSMOABIS_LIBS) \
 	$(LIBOSMOSIGTRAN_LIBS) \
 	$(LIBOSMOMGCPCLIENT_LIBS) \
@@ -89,6 +108,7 @@
 	$(top_builddir)/src/osmo-bsc/neighbor_ident.o \
 	$(LIBOSMOCORE_LIBS) \
 	$(LIBOSMOGSM_LIBS) \
+	$(LIBOSMOCTRL_LIBS) \
 	$(NULL)
 
 .PHONY: update_exp

-- 
To view, visit https://gerrit.osmocom.org/c/osmo-bsc/+/9342
To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings

Gerrit-Project: osmo-bsc
Gerrit-Branch: master
Gerrit-Change-Id: I38ad8fa645c08900e0e1f1b4b96136bc6d96b3ab
Gerrit-Change-Number: 9342
Gerrit-PatchSet: 10
Gerrit-Owner: laforge <laforge at gnumonks.org>
Gerrit-Assignee: Neels Hofmeyr <nhofmeyr at sysmocom.de>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: laforge <laforge at gnumonks.org>
Gerrit-Reviewer: pespin <pespin at sysmocom.de>
Gerrit-CC: Neels Hofmeyr <nhofmeyr at sysmocom.de>
Gerrit-MessageType: merged
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osmocom.org/pipermail/gerrit-log/attachments/20190618/5eec661e/attachment.html>


More information about the gerrit-log mailing list