gsup_client: allow passing a unit id to identify with HLR

Before, each GSUP client would contact the HLR with an identical unit id, i.e.
"SGSN-00-00-00-00-00-00", with the result that some messages were sucked off by
the wrong client.

Pass explicit unit name from each gsup client user, so that OsmoMSC is "MSC"
and OsmoSGSN is "SGSN". Hence the HLR can properly route the messages.

Todo: also set some values instead of the zeros.

Unrelated cosmetic change while editing the arguments: gsup_client_create()'s
definition's oap client config arg name mismatched the one used in the
declaration. Use oapc_config in both.

Change-Id: I3f8d6dd47c7013920e2a4bde006ed77afd974e80

2 files changed, 15 insertions, 5 deletions

diff --git a/openbsc/src/libcommon/gsup_client.c b/openbsc/src/libcommon/gsup_client.c
index 2e920a6b6..3bceaa72a 100644
--- a/openbsc/src/libcommon/gsup_client.c
+++ b/openbsc/src/libcommon/gsup_client.c
@@ -173,10 +173,13 @@ static int gsup_client_read_cb(struct ipa_client_conn *link, struct msgb *msg)
 	struct ipaccess_head_ext *he = (struct ipaccess_head_ext *) msgb_l2(msg);
 	struct gsup_client *gsupc = (struct gsup_client *)link->data;
 	int rc;
-	static struct ipaccess_unit ipa_dev = {
-		.unit_name = "SGSN"
+	struct ipaccess_unit ipa_dev = {
+		/* see gsup_client_create() on const vs non-const */
+		.unit_name = (char*)gsupc->unit_name,
 	};
 
+	OSMO_ASSERT(ipa_dev.unit_name);
+
 	msg->l2h = &hh->data[0];
 
 	rc = ipaccess_bts_handle_ccm(link, &ipa_dev, msg);
@@ -263,7 +266,8 @@ static void start_test_procedure(struct gsup_client *gsupc)
 	gsup_client_send_ping(gsupc);
 }
 
-struct gsup_client *gsup_client_create(const char *ip_addr,
+struct gsup_client *gsup_client_create(const char *unit_name,
+				       const char *ip_addr,
 				       unsigned int tcp_port,
 				       gsup_client_read_cb_t read_cb,
 				       struct oap_client_config *oapc_config)
@@ -274,6 +278,12 @@ struct gsup_client *gsup_client_create(const char *ip_addr,
 	gsupc = talloc_zero(tall_bsc_ctx, struct gsup_client);
 	OSMO_ASSERT(gsupc);
 
+	/* struct ipaccess_unit has a non-const unit_name, so let's copy to be
+	 * able to have a non-const unit_name here as well. To not taint the
+	 * public gsup_client API, let's store it in a const char* anyway. */
+	gsupc->unit_name = talloc_strdup(gsupc, unit_name);
+	OSMO_ASSERT(gsupc->unit_name);
+
 	/* a NULL oapc_config will mark oap_state disabled. */
 	rc = oap_client_init(oapc_config, &gsupc->oap_state);
 	if (rc != 0)
diff --git a/openbsc/src/libcommon/gsup_test_client.c b/openbsc/src/libcommon/gsup_test_client.c
index 8be4e7aea..c71a522e5 100644
--- a/openbsc/src/libcommon/gsup_test_client.c
+++ b/openbsc/src/libcommon/gsup_test_client.c
@@ -276,8 +276,8 @@ int main(int argc, char **argv)
 
 	osmo_init_logging(&gsup_test_client_log_info);
 
-	g_gc = gsup_client_create(server_host, server_port, gsupc_read_cb,
-				       NULL);
+	g_gc = gsup_client_create("GSUPTEST", server_host, server_port,
+				  gsupc_read_cb, NULL);
 
 
 	signal(SIGINT, sig_cb);