/*
  * RTP network protocol

  * Copyright (c) 2002 Fabrice Bellard

  *

  * This file is part of FFmpeg.
  *
  * FFmpeg 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.

  *

  * FFmpeg 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 FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  */

 
 /**

  * @file

  * RTP protocol
  */
 

 #include "libavutil/parseutils.h"

 #include "libavutil/avstring.h"

 #include "avformat.h"

 #include "avio_internal.h"

 #include "rtpdec.h"

 #include "url.h"

 #include <stdarg.h>

 #include "internal.h"

 #include "network.h"

 #include "os_support.h"

 #include <fcntl.h>

 #if HAVE_POLL_H
 #include <sys/poll.h>

 #endif

 
 typedef struct RTPContext {
     URLContext *rtp_hd, *rtcp_hd;
     int rtp_fd, rtcp_fd;
 } RTPContext;
 
 /**
  * If no filename is given to av_open_input_file because you want to
  * get the local port first, then you must call this function to set
  * the remote server address.
  *

  * @param h media file context

  * @param uri of the remote server
  * @return zero if no error.
  */

 int ff_rtp_set_remote_url(URLContext *h, const char *uri)

 {
     RTPContext *s = h->priv_data;
     char hostname[256];
     int port;

     char buf[1024];
     char path[1024];

     av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &port,

                  path, sizeof(path), uri);

     ff_url_join(buf, sizeof(buf), "udp", NULL, hostname, port, "%s", path);

     ff_udp_set_remote_url(s->rtp_hd, buf);

     ff_url_join(buf, sizeof(buf), "udp", NULL, hostname, port + 1, "%s", path);

     ff_udp_set_remote_url(s->rtcp_hd, buf);

     return 0;
 }
 
 

 /**
  * add option to url of the form:
  * "http://host:port/path?option1=val1&option2=val2...
  */
 

 static av_printf_format(3, 4) void url_add_option(char *buf, int buf_size, const char *fmt, ...)

 {
     char buf1[1024];
     va_list ap;
 
     va_start(ap, fmt);
     if (strchr(buf, '?'))

         av_strlcat(buf, "&", buf_size);

     else

         av_strlcat(buf, "?", buf_size);

     vsnprintf(buf1, sizeof(buf1), fmt, ap);

     av_strlcat(buf, buf1, buf_size);

     va_end(ap);
 }
 

 static void build_udp_url(char *buf, int buf_size,

                           const char *hostname, int port,

                           int local_port, int ttl,

                           int max_packet_size, int connect)

 {

     ff_url_join(buf, buf_size, "udp", NULL, hostname, port, NULL);

     if (local_port >= 0)
         url_add_option(buf, buf_size, "localport=%d", local_port);
     if (ttl >= 0)
         url_add_option(buf, buf_size, "ttl=%d", ttl);

     if (max_packet_size >=0)
         url_add_option(buf, buf_size, "pkt_size=%d", max_packet_size);

     if (connect)
         url_add_option(buf, buf_size, "connect=1");

     url_add_option(buf, buf_size, "fifo_size=0");

 }
 

 /**

  * url syntax: rtp://host:port[?option=val...]

  * option: 'ttl=n'            : set the ttl value (for multicast only)
  *         'rtcpport=n'       : set the remote rtcp port to n
  *         'localrtpport=n'   : set the local rtp port to n
  *         'localrtcpport=n'  : set the local rtcp port to n
  *         'pkt_size=n'       : set max packet size

  *         'connect=0/1'      : do a connect() on the UDP socket

  * deprecated option:
  *         'localport=n'      : set the local port to n

  *

  * if rtcpport isn't set the rtcp port will be the rtp port + 1
  * if local rtp port isn't set any available port will be used for the local
  * rtp and rtcp ports
  * if the local rtcp port is not set it will be the local rtp port + 1

  */

 static int rtp_open(URLContext *h, const char *uri, int flags)
 {

     RTPContext *s = h->priv_data;

     int rtp_port, rtcp_port,

         ttl, connect,

         local_rtp_port, local_rtcp_port, max_packet_size;

     char hostname[256];
     char buf[1024];
     char path[1024];

     const char *p;

     av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &rtp_port,

                  path, sizeof(path), uri);

     /* extract parameters */
     ttl = -1;

     rtcp_port = rtp_port+1;
     local_rtp_port = -1;
     local_rtcp_port = -1;

     max_packet_size = -1;

     connect = 0;

     p = strchr(uri, '?');
     if (p) {

         if (av_find_info_tag(buf, sizeof(buf), "ttl", p)) {

             ttl = strtol(buf, NULL, 10);
         }

         if (av_find_info_tag(buf, sizeof(buf), "rtcpport", p)) {

             rtcp_port = strtol(buf, NULL, 10);
         }

         if (av_find_info_tag(buf, sizeof(buf), "localport", p)) {

             local_rtp_port = strtol(buf, NULL, 10);
         }

         if (av_find_info_tag(buf, sizeof(buf), "localrtpport", p)) {

             local_rtp_port = strtol(buf, NULL, 10);
         }

         if (av_find_info_tag(buf, sizeof(buf), "localrtcpport", p)) {

             local_rtcp_port = strtol(buf, NULL, 10);

         }

         if (av_find_info_tag(buf, sizeof(buf), "pkt_size", p)) {

             max_packet_size = strtol(buf, NULL, 10);
         }

         if (av_find_info_tag(buf, sizeof(buf), "connect", p)) {

             connect = strtol(buf, NULL, 10);
         }

     }

     build_udp_url(buf, sizeof(buf),

                   hostname, rtp_port, local_rtp_port, ttl, max_packet_size,
                   connect);

     if (ffurl_open(&s->rtp_hd, buf, flags, &h->interrupt_callback, NULL) < 0)

         goto fail;

     if (local_rtp_port>=0 && local_rtcp_port<0)

         local_rtcp_port = ff_udp_get_local_port(s->rtp_hd) + 1;

     build_udp_url(buf, sizeof(buf),

                   hostname, rtcp_port, local_rtcp_port, ttl, max_packet_size,
                   connect);

     if (ffurl_open(&s->rtcp_hd, buf, flags, &h->interrupt_callback, NULL) < 0)

         goto fail;

     /* just to ease handle access. XXX: need to suppress direct handle
        access */

     s->rtp_fd = ffurl_get_file_handle(s->rtp_hd);
     s->rtcp_fd = ffurl_get_file_handle(s->rtcp_hd);

     h->max_packet_size = s->rtp_hd->max_packet_size;

     h->is_streamed = 1;
     return 0;
 
  fail:
     if (s->rtp_hd)

         ffurl_close(s->rtp_hd);

     if (s->rtcp_hd)

         ffurl_close(s->rtcp_hd);

     return AVERROR(EIO);

 }
 

 static int rtp_read(URLContext *h, uint8_t *buf, int size)

 {
     RTPContext *s = h->priv_data;

     struct sockaddr_storage from;

     socklen_t from_len;

     int len, n;
     struct pollfd p[2] = {{s->rtp_fd, POLLIN, 0}, {s->rtcp_fd, POLLIN, 0}};
 

     for(;;) {

         if (ff_check_interrupt(&h->interrupt_callback))

             return AVERROR_EXIT;

         /* build fdset to listen to RTP and RTCP packets */

         n = poll(p, 2, 100);

         if (n > 0) {
             /* first try RTCP */

             if (p[1].revents & POLLIN) {

                 from_len = sizeof(from);
                 len = recvfrom (s->rtcp_fd, buf, size, 0,
                                 (struct sockaddr *)&from, &from_len);
                 if (len < 0) {

                     if (ff_neterrno() == AVERROR(EAGAIN) ||
                         ff_neterrno() == AVERROR(EINTR))

                         continue;

                     return AVERROR(EIO);

                 }
                 break;
             }
             /* then RTP */

             if (p[0].revents & POLLIN) {

                 from_len = sizeof(from);
                 len = recvfrom (s->rtp_fd, buf, size, 0,
                                 (struct sockaddr *)&from, &from_len);
                 if (len < 0) {

                     if (ff_neterrno() == AVERROR(EAGAIN) ||
                         ff_neterrno() == AVERROR(EINTR))

                         continue;

                     return AVERROR(EIO);

                 }
                 break;
             }

         } else if (n < 0) {

             if (ff_neterrno() == AVERROR(EINTR))

                 continue;

             return AVERROR(EIO);

         }
     }
     return len;
 }
 

 static int rtp_write(URLContext *h, const uint8_t *buf, int size)

 {
     RTPContext *s = h->priv_data;

     int ret;

     URLContext *hd;

     if (RTP_PT_IS_RTCP(buf[1])) {

         /* RTCP payload type */
         hd = s->rtcp_hd;
     } else {
         /* RTP payload type */
         hd = s->rtp_hd;
     }
 

     ret = ffurl_write(hd, buf, size);

     return ret;
 }
 
 static int rtp_close(URLContext *h)
 {
     RTPContext *s = h->priv_data;
 

     ffurl_close(s->rtp_hd);
     ffurl_close(s->rtcp_hd);

     return 0;
 }
 
 /**

  * Return the local rtp port used by the RTP connection

  * @param h media file context

  * @return the local port number
  */
 

 int ff_rtp_get_local_rtp_port(URLContext *h)

 {
     RTPContext *s = h->priv_data;

     return ff_udp_get_local_port(s->rtp_hd);

 }
 

 /**
  * Return the local rtcp port used by the RTP connection

  * @param h media file context

  * @return the local port number
  */
 

 int ff_rtp_get_local_rtcp_port(URLContext *h)

 {
     RTPContext *s = h->priv_data;

     return ff_udp_get_local_port(s->rtcp_hd);

 }
 

 static int rtp_get_file_handle(URLContext *h)
 {
     RTPContext *s = h->priv_data;
     return s->rtp_fd;
 }

 static int rtp_get_multi_file_handle(URLContext *h, int **handles,
                                      int *numhandles)
 {

     RTPContext *s = h->priv_data;

     int *hs       = *handles = av_malloc(sizeof(**handles) * 2);
     if (!hs)
         return AVERROR(ENOMEM);
     hs[0] = s->rtp_fd;
     hs[1] = s->rtcp_fd;
     *numhandles = 2;
     return 0;

 }
 

 URLProtocol ff_rtp_protocol = {

     .name                      = "rtp",
     .url_open                  = rtp_open,
     .url_read                  = rtp_read,
     .url_write                 = rtp_write,
     .url_close                 = rtp_close,
     .url_get_file_handle       = rtp_get_file_handle,
     .url_get_multi_file_handle = rtp_get_multi_file_handle,
     .priv_data_size            = sizeof(RTPContext),
     .flags                     = URL_PROTOCOL_FLAG_NETWORK,

 };