ref: 88ccea37f65b87312292b2b1a107c39927c6a2c3
dir: /sys/src/cmd/ip/snoopy/rtcp.c/
#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 octet 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 int p_seprint(Msg *m) { int rc, i, frac; float dlsr; Hdr*h; Report*r; 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)((r->lost[0] * 100.) / 256.); r->lost[0] = 0; dlsr = 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", nil, nil, p_seprint, nil, nil, nil, defaultframer, };