Add WIP code for SCCP User Adaptation (SUA) and SCCP User SAP

The idea of this code is to
* provide a SCCP User SAP as boundary between the User of SCCP
  or SCCP-like transport like SUA
* implement the minimum subset of SUA to transport RANAP messages
  betweene HNB-GW and MSC/SGSN

At this point
* we don't yet implement the proper state machines and timer
* we don't imp[lement the SCCP RESET procedure
* we don't implement AS/ASP management

The code is full of FIXMEs whihc hopefully will get fixed gradually.

After some cleanup + verification, it should move to a library, possibly
either replacing/renaming libomo-sccp, or adding it to libosmo-netif?

1 files changed, 79 insertions, 0 deletions

diff --git a/sigtran/sua_server_test.c b/sigtran/sua_server_test.c
new file mode 100644
index 0000000..be123c2
--- /dev/null
+++ b/sigtran/sua_server_test.c
@@ -0,0 +1,79 @@
+#include "sua_test_common.h"
+
+struct osmo_prim_hdr *make_conn_resp(struct osmo_scu_connect_param *param)
+{
+	struct msgb *msg = msgb_alloc(1024, "conn_resp");
+	struct osmo_scu_prim *prim;
+
+	prim = (struct osmo_scu_prim *) msgb_put(msg, sizeof(*prim));
+	osmo_prim_init(&prim->oph, SCCP_SAP_USER,
+			OSMO_SCU_PRIM_N_CONNECT,
+			PRIM_OP_RESPONSE, msg);
+	memcpy(&prim->u.connect, param, sizeof(prim->u.connect));
+	return &prim->oph;
+}
+
+static int sccp_sap_up(struct osmo_prim_hdr *oph, void *link)
+{
+	struct osmo_scu_prim *prim = (struct osmo_scu_prim *) oph;
+	struct osmo_prim_hdr *resp = NULL;
+	const uint8_t payload[] = { 0xb1, 0xb2, 0xb3 };
+
+	printf("sccp_sap_up(%s)\n", osmo_sccp_prim_name(oph));
+
+	switch (OSMO_PRIM_HDR(oph)) {
+	case OSMO_PRIM(OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_CONFIRM):
+		/* confirmation of outbound connection */
+		break;
+	case OSMO_PRIM(OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_INDICATION):
+		/* indication of new inbound connection request*/
+		printf("N-CONNECT.ind(X->%u)\n", prim->u.connect.conn_id);
+		resp = make_conn_resp(&prim->u.connect);
+		break;
+	case OSMO_PRIM(OSMO_SCU_PRIM_N_DISCONNECT, PRIM_OP_INDICATION):
+		/* indication of disconnect */
+		printf("N-DISCONNECT.ind(%u)\n", prim->u.disconnect.conn_id);
+		break;
+	case OSMO_PRIM(OSMO_SCU_PRIM_N_DATA, PRIM_OP_INDICATION):
+		/* connection-oriented data received */
+		printf("N-DATA.ind(%u, %s)\n", prim->u.data.conn_id,
+			osmo_hexdump(msgb_l2(oph->msg), msgb_l2len(oph->msg)));
+		resp = make_dt1_req(prim->u.data.conn_id, payload, sizeof(payload));
+		break;
+	case OSMO_PRIM(OSMO_SCU_PRIM_N_UNITDATA, PRIM_OP_INDICATION):
+		/* connection-oriented data received */
+		printf("N-UNITDATA.ind(%s)\n", 
+			osmo_hexdump(msgb_l2(oph->msg), msgb_l2len(oph->msg)));
+		tx_unitdata(link);
+		break;
+	}
+
+	if (resp)
+		osmo_osmo_sua_user_link_down(link, resp);
+
+	msgb_free(oph->msg);
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	struct osmo_sua_user *user;
+	void *ctx = talloc_named_const(NULL, 1, "root");
+	int rc;
+
+	osmo_sua_set_log_area(DSUA);
+	xua_set_log_area(DXUA);
+
+	osmo_init_logging(&test_log_info);
+
+	user = osmo_sua_user_create(ctx, sccp_sap_up);
+
+	rc = sua_server_listen(user, "127.0.0.1", 2342);
+	if (rc < 0) {
+		exit(1);
+	}
+
+	while (1) {
+		osmo_select_main(0);
+	}
+}