1 files changed, 76 insertions, 0 deletions
diff --git a/src/cmd/ip/snoopy/rtp.c b/src/cmd/ip/snoopy/rtp.c
new file mode 100755
index 00000000..1e8e5ab8
--- /dev/null
+++ b/src/cmd/ip/snoopy/rtp.c
@@ -0,0 +1,76 @@
+#include <u.h>
+#include <libc.h>
+#include <ip.h>
+#include "dat.h"
+#include "protos.h"
+
+typedef struct Hdr Hdr;
+struct Hdr {
+	uchar	hdr;		// RTP header
+	uchar	marker;	// Payload and marker
+	uchar	seq[2];	// Sequence number
+	uchar	ts[4];		// Time stamp
+	uchar	ssrc[4];	// Synchronization source identifier
+};
+
+enum{
+	RTPLEN = 12,		// Minimum size of an RTP header
+};
+
+
+static void
+p_compile(Filter *f)
+{
+	sysfatal("unknown rtp field: %s", f->s);
+}
+
+static int
+p_filter(Filter *f, Msg *m)
+{
+	USED(f);
+	USED(m);
+	return 0;
+}
+
+static int
+p_seprint(Msg *m)
+{
+	Hdr*h;
+	ushort seq;
+	ulong ssrc, ts;
+	int cc, i;
+
+	if(m->pe - m->ps < RTPLEN)
+		return -1;
+
+	h = (Hdr*)m->ps;
+	cc = h->hdr & 0xf;
+	if(m->pe - m->ps < RTPLEN + cc * 4)
+		return -1;
+
+	m->ps += RTPLEN;
+
+	seq = NetS(h->seq);
+	ts = NetL(h->ts);
+	ssrc = NetL(h->ssrc);
+
+	m->p = seprint(m->p, m->e, "version=%d x=%d cc=%d seq=%d ts=%ld ssrc=%ulx",
+				(h->hdr >> 6) & 3, (h->hdr >> 4) & 1, cc, seq, ts, ssrc);
+	for(i = 0; i < cc; i++){
+		m->p = seprint(m->p, m->e, " csrc[%d]=%d",
+				i, NetL(m->ps));
+		m->ps += 4;
+	}
+	m->pr = nil;
+	return 0;
+}
+
+Proto rtp = {
+	"rtp",
+	p_compile,
+	p_filter,
+	p_seprint,
+	nil,
+	nil,
+	defaultframer,
+};