initial skeleton for accepting UMA/GAN connections

1 files changed, 151 insertions, 0 deletions

diff --git a/openbsc/src/osmo-ganc/ganc_server.c b/openbsc/src/osmo-ganc/ganc_server.c
new file mode 100644
index 000000000..b8153c9e5
--- /dev/null
+++ b/openbsc/src/osmo-ganc/ganc_server.c
@@ -0,0 +1,151 @@
+
+#include <unistd.h>
+#include <stdio.h>
+#include <errno.h>
+
+#include <arpa/inet.h>
+
+#include <osmocom/core/socket.h>
+#include <osmocom/core/talloc.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/gsm/tlv.h>
+#include <osmocom/gsm/protocol/gsm_44_318.h>
+
+#include "conn.h"
+#include "ganc_data.h"
+
+static struct msgb *unc_msgb_alloc(void)
+{
+	return msgb_alloc_headroom(1024+128, 128, "GANC Tx");
+}
+
+static int unc_peer_tx(struct gan_peer *peer, struct msgb *msg)
+{
+	return osmo_conn_enqueue(peer->conn, msg);
+}
+
+static int tx_unc_disco_acc(struct gan_peer *peer, const char *segw_host,
+			    const char *ganc_host)
+{
+	struct msgb *msg = unc_msgb_alloc();
+	struct gan_rc_csr_hdr *gh = (struct gan_rc_csr_hdr*) msg->l2h;
+
+	if (!msg)
+		return -ENOMEM;
+
+	gh->pdisc = GA_PDISC_RC;
+	gh->msg_type = GA_MT_RC_DISCOVERY_ACCEPT;
+
+	msgb_tlv_put(msg, GA_IE_DEF_SEGW_FQDN, strlen(segw_host)+1, (uint8_t *) segw_host);
+	msgb_tlv_put(msg, GA_IE_DEF_GANC_FQDN, strlen(ganc_host)+1, (uint8_t *) ganc_host);
+
+	return unc_peer_tx(peer, msg);
+}
+
+static int rx_unc_discovery_req(struct gan_peer *peer, struct msgb *msg,
+				struct gan_rc_csr_hdr *gh)
+{
+	struct tlv_parsed tp;
+
+	tlv_parse(&tp, &tvlv_att_def, gh->data, msg->len - sizeof(*gh), 0, 0);
+
+	if (TLVP_PRESENT(&tp, GA_IE_MI)) {
+		char mi_string[32];
+		gsm48_mi_to_string(&mi_string, sizeof(mi_string),
+				   TLVP_VAL(&tp, GA_IE_MI), TLVP_LEN(&tp, GA_IE_MI));
+
+		printf("DISCOVERY from %s\n", mi_string);
+	}
+
+	return tx_unc_disco_acc(peer, "segw.uma.sysmocom.de",
+				"ganc.uma.sysmocom.de");
+}
+
+static int rx_unc_rc(struct gan_peer *peer, struct msgb *msg, struct gan_rc_csr_hdr *gh)
+{
+	switch (gh->msg_type) {
+	case GA_MT_RC_DISCOVERY_REQUEST:
+		return rx_unc_discovery_req(peer, msg, gh);
+	case GA_MT_RC_REGISTER_REQUEST:
+	case GA_MT_RC_DEREGISTER:
+		break;
+	}
+
+	return 0;
+}
+
+static int rx_unc_msg(struct gan_peer *peer, struct msgb *msg)
+{
+	struct gan_rc_csr_hdr *gh = (struct gan_rc_csr_hdr *) msg->l2h;
+
+	printf("PDISC=%u TYPE=%u\n", gh->pdisc, gh->msg_type);
+
+	switch (gh->pdisc) {
+	case GA_PDISC_RC:
+		return rx_unc_rc(peer, msg, gh);
+	case GA_PDISC_CSR:
+	case GA_PDISC_PSR:
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static int unc_read_cb(struct osmo_conn *conn)
+{
+	struct msgb *msg;
+	struct gan_rc_csr_hdr *gh;
+	int rc;
+
+	msg = msgb_alloc_headroom(1024 + 128, 128, "UNC Read");
+	if (!msg)
+		return -ENOMEM;
+
+	gh = (struct gan_rc_csr_hdr *) msg->data;
+	rc = read(conn->queue.bfd.fd, msg->data, sizeof(gh->len));
+	if (rc <= 0) {
+		msgb_free(msg);
+		return rc;
+	} else if (rc != sizeof(gh->len)) {
+		msgb_free(msg);
+		return -EIO;
+	}
+	msg->l2h = msg->data;
+	msgb_put(msg, rc);
+
+	rc = read(conn->queue.bfd.fd, msg->data, ntohs(gh->len));
+	if (rc <= 0)
+		return rc;
+	else if (rc != ntohs(gh->len)) {
+		msgb_free(msg);
+		return -EIO;
+	}
+
+	msgb_put(msg, rc);
+
+	return rx_unc_msg(conn->priv, msg);
+}
+
+static void unc_accept_cb(struct osmo_conn *conn)
+{
+	struct gan_peer *peer = talloc_zero(conn, struct gan_peer);
+	printf("accepted connection\n");
+
+	peer->conn = conn;
+	conn->priv = peer;
+}
+
+
+int ganc_server_start(const char *host, uint16_t port)
+{
+	struct osmo_link *link;
+
+	link = osmo_link_create(NULL, host, port, unc_read_cb, 10);
+	if (!link)
+		return -ENOMEM;
+
+	osmo_link_listen(link, unc_accept_cb);
+
+	return 0;
+}