Subversion Repositories planix.SVN

#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,
};