osmux: Use DUMMY ft msg as per Osmux spec
That MGCP_DUMMY_LOAD is an old hack prior to Osmux spec update, and it's
not nice since it cannot be 100% distinguished from a usual AMR ft
frame.
Let's use the correct DUMMY ft type and build it according spec. Allow
handling differently the old format for a while until we are sure no old
implementations (like bsc-nat) exist sending that kind of message.
Change-Id: Ib17d20b87b28aade49ba60519b56a96e694819af
diff --git a/src/libosmo-mgcp/mgcp_osmux.c b/src/libosmo-mgcp/mgcp_osmux.c
index 7a817f8..3b788b6 100644
--- a/src/libosmo-mgcp/mgcp_osmux.c
+++ b/src/libosmo-mgcp/mgcp_osmux.c
@@ -20,6 +20,7 @@
#include <osmocom/netif/osmux.h>
#include <osmocom/netif/rtp.h>
+#include <osmocom/netif/amr.h>
#include <osmocom/mgcp/mgcp.h>
#include <osmocom/mgcp/mgcp_internal.h>
@@ -554,7 +555,8 @@
* \returns bytes sent, -1 on error */
int osmux_send_dummy(struct mgcp_endpoint *endp, struct mgcp_conn_rtp *conn)
{
- char buf[1 + sizeof(uint8_t)];
+ struct osmux_hdr *osmuxh;
+ int buf_len;
struct in_addr addr_unset = {};
/*! The dummy packet will not be sent via the actual OSMUX connection,
@@ -566,9 +568,6 @@
* endpoint may have already punched the hole in the firewall. This
* approach is simple though. */
- buf[0] = MGCP_DUMMY_LOAD;
- memcpy(&buf[1], &conn->osmux.cid, sizeof(conn->osmux.cid));
-
/* Wait until we have the connection information from MDCX */
if (memcmp(&conn->end.addr, &addr_unset, sizeof(addr_unset)) == 0)
return 0;
@@ -576,12 +575,19 @@
if (endp_osmux_state_check(endp, conn, true) < 0)
return 0;
+ buf_len = sizeof(struct osmux_hdr) + osmo_amr_bytes(AMR_FT_0);
+ osmuxh = (struct osmux_hdr *) alloca(buf_len);
+ memset(osmuxh, 0, buf_len);
+ osmuxh->ft = OSMUX_FT_DUMMY;
+ osmuxh->amr_ft = AMR_FT_0;
+ osmuxh->circuit_id = conn->osmux.cid;
+
LOGPCONN(conn->conn, DLMGCP, LOGL_DEBUG,
"sending OSMUX dummy load to %s:%u CID %u\n",
inet_ntoa(conn->end.addr), ntohs(conn->end.rtp_port), conn->osmux.cid);
return mgcp_udp_send(osmux_fd.fd, &conn->end.addr,
- conn->end.rtp_port, buf, sizeof(buf));
+ conn->end.rtp_port, (char*)osmuxh, buf_len);
}
/* bsc-nat allocates/releases the Osmux circuit ID. +7 to round up to 8 bit boundary. */