Implement AoIP, port to M3UA SIGTRAN (large addition and refactoring)

This was originally a long series of commits converging to the final result
seen in this patch. It does not make much sense to review the smaller steps'
trial and error, we need to review this entire change as a whole.

Implement AoIP in osmo-msc and osmo-bsc.

Change over to the new libosmo-sigtran API with support for proper
SCCP/M3UA/SCTP stacking, as mandated by 3GPP specifications for the IuCS and
IuPS interfaces.

From here on, a separate osmo-stp process is required for SCCP routing between
OsmoBSC / OsmoHNBGW <-> OsmoMSC / OsmoSGSN

jenkins.sh: build from libosmo-sccp and osmo-iuh master branches now for new
M3UA SIGTRAN.

Patch-by: pmaier, nhofmeyr, laforge
Change-Id: I5ae4e05ee7c57cad341ea5e86af37c1f6b0ffa77
diff --git a/src/libmsc/msc_vty.c b/src/libmsc/msc_vty.c
index 82dc7d6..01e7e82 100644
--- a/src/libmsc/msc_vty.c
+++ b/src/libmsc/msc_vty.c
@@ -64,6 +64,26 @@
 	return CMD_SUCCESS;
 }
 
+DEFUN(cfg_msc_cs7_instance_a,
+      cfg_msc_cs7_instance_a_cmd,
+      "cs7-instance-a <0-15>",
+      "Set SS7 to be used by the A-Interface.\n" "SS7 instance reference number\n")
+{
+	struct gsm_network *gsmnet = gsmnet_from_vty(vty);
+	gsmnet->a.cs7_instance = atoi(argv[0]);
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_msc_cs7_instance_iu,
+      cfg_msc_cs7_instance_iu_cmd,
+      "cs7-instance-iu <0-15>",
+      "Set SS7 to be used by the Iu-Interface.\n" "SS7 instance reference number\n")
+{
+	struct gsm_network *gsmnet = gsmnet_from_vty(vty);
+	gsmnet->iu.cs7_instance = atoi(argv[0]);
+	return CMD_SUCCESS;
+}
+
 static int config_write_msc(struct vty *vty)
 {
 	struct gsm_network *gsmnet = gsmnet_from_vty(vty);
@@ -72,6 +92,11 @@
 	vty_out(vty, " %sassign-tmsi%s",
 		gsmnet->vlr->cfg.assign_tmsi? "" : "no ", VTY_NEWLINE);
 
+	vty_out(vty, " cs7-instance-a %u%s", gsmnet->a.cs7_instance,
+		VTY_NEWLINE);
+	vty_out(vty, " cs7-instance-iu %u%s", gsmnet->iu.cs7_instance,
+		VTY_NEWLINE);
+
 	mgcpgw_client_config_write(vty, " ");
 #ifdef BUILD_IU
 	iu_vty_config_write(vty, " ");
@@ -123,6 +148,9 @@
 	vty_install_default(MSC_NODE);
 	install_element(MSC_NODE, &cfg_msc_assign_tmsi_cmd);
 	install_element(MSC_NODE, &cfg_msc_no_assign_tmsi_cmd);
+	install_element(MSC_NODE, &cfg_msc_cs7_instance_a_cmd);
+	install_element(MSC_NODE, &cfg_msc_cs7_instance_iu_cmd);
+
 	mgcpgw_client_vty_init(MSC_NODE, &msc_network->mgcpgw.conf);
 #ifdef BUILD_IU
 	iu_vty_init(MSC_NODE, &msc_network->iu.rab_assign_addr_enc);