new goodies

src/cmd/ip/snoopy/rtcp.c

@@ -0,0 +1,97 @@
+#include <u.h>
+#include <libc.h>
+#include <ip.h>
+#include "dat.h"
+#include "protos.h"
+
+typedef struct Hdr Hdr;
+struct Hdr {
+	uchar	hdr;			// RTCP header
+	uchar	pt;			// Packet type
+	uchar	len[2];		// Report length
+	uchar	ssrc[4];		// Synchronization source identifier
+	uchar	ntp[8];		// NTP time stamp
+	uchar	rtp[4];		// RTP time stamp
+	uchar	pktc[4];		// Sender's packet count
+	uchar	octc[4];		// Sender's octect count
+};
+
+typedef struct Report Report;
+struct Report {
+	uchar	ssrc[4];		// SSRC identifier
+	uchar	lost[4];		// Fraction + cumu lost
+	uchar	seqhi[4];		// Highest seq number received
+	uchar	jitter[4];		// Interarrival jitter
+	uchar	lsr[4];		// Last SR
+	uchar	dlsr[4];		// Delay since last SR
+};
+
+enum{
+	RTCPLEN = 28,		// Minimum size of an RTCP header
+	REPORTLEN = 24,
+};
+
+
+static void
+p_compile(Filter *f)
+{
+	sysfatal("unknown rtcp 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;
+	Report*r;
+	int rc, i, frac;
+	float dlsr;
+
+	if(m->pe - m->ps < RTCPLEN)
+		return -1;
+
+	h = (Hdr*)m->ps;
+	if(m->pe - m->ps < (NetS(h->len) + 1) * 4)
+		return -1;
+
+	rc = h->hdr & 0x1f;
+	m->ps += RTCPLEN;
+	m->p = seprint(m->p, m->e, "version=%d rc=%d tp=%d ssrc=%8ux ntp=%d.%.10ud rtp=%d pktc=%d octc=%d hlen=%d",
+				(h->hdr >> 6) & 3, rc, h->pt, NetL(h->ssrc),
+				NetL(h->ntp), (uint)NetL(&h->ntp[4]), NetL(h->rtp),
+				NetL(h->pktc), NetL(h->octc),
+				(NetS(h->len) + 1) * 4);
+
+	for(i = 0; i < rc; i++){
+		r = (Report*)m->ps;	
+		m->ps += REPORTLEN;
+
+		frac = (int)(((float)r->lost[0] * 100.) / 256.);
+		r->lost[0] = 0;
+		dlsr = (float)NetL(r->dlsr) / 65536.;
+
+		m->p = seprint(m->p, m->e, "\n\trr(csrc=%8ux frac=%3d%% cumu=%10d seqhi=%10ud jitter=%10d lsr=%8ux dlsr=%f)",
+				NetL(r->ssrc), frac, NetL(r->lost), NetL(r->seqhi),
+				NetL(r->jitter), NetL(r->lsr), 
+				dlsr);
+	}
+	m->pr = nil;
+	return 0;
+}
+
+Proto rtcp = {
+	"rtcp",
+	p_compile,
+	p_filter,
+	p_seprint,
+	nil,
+	nil,
+	defaultframer,
+};