/***************************************************************************** * rtcp.c: RTCP stream output support ***************************************************************************** * Copyright ? 2007 Rémi Denis-Courmont * $Id$ * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA *****************************************************************************//***************************************************************************** * Preamble *****************************************************************************/#ifdef HAVE_CONFIG_H# include "config.h"#endif#include <vlc_common.h>#include <vlc_block.h>#include <vlc_network.h>#include <vlc_sout.h>#include "rtp.h"#include <assert.h>/* * NOTE on RTCP implementation: * - there is a single sender (us), no conferencing here! => n = sender = 1, * - as such we need not bother to include Receiver Reports, * - in unicast case, there is a single receiver => members = 1 + 1 = 2, *   and obviously n > 25% of members, * - in multicast case, we do not want to maintain the number of receivers *   and we assume it is big (i.e. than 3) because that's what broadcasting is *   all about, * - it is assumed we_sent = true (could be wrong), since we are THE sender, * - we always send SR + SDES, while running, * - FIXME: we do not implement separate rate limiting for SDES, * - we do not implement any profile-specific extensions for the time being. */struct rtcp_sender_t{    size_t   length;  /* RTCP packet length */    uint8_t  payload[28 + 8 + (2 * 257) + 8];    int      handle;  /* RTCP socket handler */    uint32_t packets; /* RTP packets sent */    uint32_t bytes;   /* RTP bytes sent */    unsigned counter; /* RTP packets sent since last RTCP packet */};rtcp_sender_t *OpenRTCP (vlc_object_t *obj, int rtp_fd, int proto,                         bool mux){    rtcp_sender_t *rtcp;    uint8_t *ptr;    int fd;    char src[NI_MAXNUMERICHOST];    int sport;    if (net_GetSockAddress (rtp_fd, src, &sport))        return NULL;    if (mux)    {        /* RTP/RTCP mux: duplicate the socket */#ifndef WIN32        fd = dup (rtp_fd);#else        WSAPROTOCOL_INFO info;        WSADuplicateSocket (rtp_fd, GetCurrentProcessId (), &info);        fd = WSASocket (info.iAddressFamily, info.iSocketType, info.iProtocol,                        &info, 0, 0);#endif    }    else    {        /* RTCP on a separate port */        char dst[NI_MAXNUMERICHOST];        int dport;        if (net_GetPeerAddress (rtp_fd, dst, &dport))            return NULL;        sport++;        dport++;        fd = net_OpenDgram (obj, src, sport, dst, dport, AF_UNSPEC, proto);    }    if (fd == -1)        return NULL;    rtcp = malloc (sizeof (*rtcp));    if (rtcp == NULL)    {        net_Close (fd);        return NULL;    }    rtcp->handle = fd;    rtcp->bytes = rtcp->packets = rtcp->counter = 0;    ptr = (uint8_t *)strchr (src, '%');    if (ptr != NULL)        *ptr = '\0'; /* remove scope ID frop IPv6 addresses */    ptr = rtcp->payload;    /* Sender report */    ptr[0] = 2 << 6; /* V = 2, P = RC = 0 */    ptr[1] = 200; /* payload type: Sender Report */    SetWBE (ptr + 2, 6); /* length = 6 (7 double words) */    memset (ptr + 4, 0, 4); /* SSRC unknown yet */    SetQWBE (ptr + 8, NTPtime64 ());    memset (ptr + 16, 0, 12); /* timestamp and counters */    ptr += 28;    /* Source description */    uint8_t *sdes = ptr;    ptr[0] = (2 << 6) | 1; /* V = 2, P = 0, SC = 1 */    ptr[1] = 202; /* payload type: Source Description */    uint8_t *lenptr = ptr + 2;    memset (ptr + 4, 0, 4); /* SSRC unknown yet */    ptr += 8;    ptr[0] = 1; /* CNAME - mandatory */    assert (NI_MAXNUMERICHOST <= 256);    ptr[1] = strlen (src);    memcpy (ptr + 2, src, ptr[1]);    ptr += ptr[1] + 2;    static const char tool[] = PACKAGE_STRING;    ptr[0] = 6; /* TOOL */    ptr[1] = (sizeof (tool) > 256) ? 255 : (sizeof (tool) - 1);    memcpy (ptr + 2, tool, ptr[1]);    ptr += ptr[1] + 2;    while ((ptr - sdes) & 3) /* 32-bits padding */        *ptr++ = 0;    SetWBE (lenptr, (ptr - sdes - 1) >> 2);    rtcp->length = ptr - rtcp->payload;    return rtcp;}void CloseRTCP (rtcp_sender_t *rtcp){    if (rtcp == NULL)        return;    uint8_t *ptr = rtcp->payload;    uint64_t now64 = NTPtime64 ();    SetQWBE (ptr + 8, now64); /* Update the Sender Report timestamp */    /* Bye */    ptr += rtcp->length;    ptr[0] = (2 << 6) | 1; /* V = 2, P = 0, SC = 1 */    ptr[1] = 203; /* payload type: Bye */    SetWBE (ptr + 2, 1);    memcpy (ptr + 4, rtcp->payload + 4, 4); /* Copy SSRC from Sender Report */    rtcp->length += 8;    /* We are THE sender, so we are more important than anybody else, so     * we can afford not to check bandwidth constraints here. */    send (rtcp->handle, rtcp->payload, rtcp->length, 0);    net_Close (rtcp->handle);    free (rtcp);}void SendRTCP (rtcp_sender_t *restrict rtcp, const block_t *rtp){    if ((rtcp == NULL) /* RTCP sender off */     || (rtp->i_buffer < 12)) /* too short RTP packet */        return;    /* Updates statistics */    rtcp->packets++;    rtcp->bytes += rtp->i_buffer;    rtcp->counter += rtp->i_buffer;    /* 1.25% rate limit */    if ((rtcp->counter / 80) < rtcp->length)        return;    uint8_t *ptr = rtcp->payload;    uint32_t last = GetDWBE (ptr + 8); // last RTCP SR send time    uint64_t now64 = NTPtime64 ();    if ((now64 >> 32) < (last + 5))        return; // no more than one SR every 5 seconds    memcpy (ptr + 4, rtp->p_buffer + 8, 4); /* SR SSRC */    SetQWBE (ptr + 8, now64);    memcpy (ptr + 16, rtp->p_buffer + 4, 4); /* RTP timestamp */    SetDWBE (ptr + 20, rtcp->packets);    SetDWBE (ptr + 24, rtcp->bytes);    memcpy (ptr + 28 + 4, rtp->p_buffer + 8, 4); /* SDES SSRC */    if (send (rtcp->handle, ptr, rtcp->length, 0) == (ssize_t)rtcp->length)        rtcp->counter = 0;}