[vlc-devel] [PATCH] Add support for AMT multicast tunneling over non-multicast enabled networks
Wayne Brassem
wbrassem at rogers.com
Mon Apr 29 18:42:25 CEST 2019
Updated submission.
Notes on this version based on previous code reviews:
1. Upon inspection it was indeed clear that there was considerable and inefficient usage of ntop and pton for IP address format conversion throughout the prior submission. This issue has been addressed and kept to a minimum, however because both the string and binary IP address format are used in function calls both are retained in the data structures.
2. All IP address comparisons are done using numeric form except for a single strcmp() occurrence where it is documented.
3. In large part the “hacks” which were imported from upd.c were to address the very real possibility that the module could receive unexpectedly large jumbo Ethernet frames. The default MTU is derived from the “normal” Ethernet frame size of 1500, but in the event a larger-than-expected frame arrives the code defends against buffer overflow and then automatically adjusts the MTU to match what was received. The alternative of allocating a pathologically large buffer for each packet is very wasteful so adopting defensive code is preferable.
4. The usage of strtok_r() was added based on the code review comments on an much earlier version of this module which used strtok() that was not thread safe. It’s probably better this way, but if strtok is preferred that’s easy enough.
Additional comments and suggestion are welcome.
Wayne.
---
modules/access/Makefile.am | 4 +
modules/access/amt.c | 1240 ++++++++++++++++++++++++++++++++++++
modules/access/amt.h | 219 +++++++
3 files changed, 1463 insertions(+)
create mode 100644 modules/access/amt.c
create mode 100644 modules/access/amt.h
diff --git a/modules/access/Makefile.am b/modules/access/Makefile.am
index 9cdf98e0a1..fec9c32005 100644
--- a/modules/access/Makefile.am
+++ b/modules/access/Makefile.am
@@ -373,6 +373,10 @@ libudp_plugin_la_SOURCES = access/udp.c
libudp_plugin_la_LIBADD = $(SOCKET_LIBS)
access_LTLIBRARIES += libudp_plugin.la
+libamt_plugin_la_SOURCES = access/amt.c access/amt.h
+libamt_plugin_la_LIBADD = $(SOCKET_LIBS)
+access_LTLIBRARIES += libamt_plugin.la
+
libunc_plugin_la_SOURCES = access/unc.c access/smb_common.h
libunc_plugin_la_LIBADD = -lmpr -lnetapi32
if HAVE_WIN32
diff --git a/modules/access/amt.c b/modules/access/amt.c
new file mode 100644
index 0000000000..01109607a3
--- /dev/null
+++ b/modules/access/amt.c
@@ -0,0 +1,1240 @@
+/**
+ * @file amt.c
+ * @brief Automatic Multicast Tunneling Protocol (AMT) file for VLC media player
+ * Allows multicast streaming when not in a multicast-enabled network
+ * Currently IPv4 is supported, but IPv6 is not yet.
+ *
+ * Copyright (C) 2018 VLC authors and VideoLAN
+ * Copyright (c) Juniper Networks, Inc., 2018. All rights reserved.
+ *
+ * Authors: Christophe Massiot <massiot at via.ecp.fr> - original UDP code
+ * Tristan Leteurtre <tooney at via.ecp.fr> - original UDP code
+ * Laurent Aimar <fenrir at via.ecp.fr> - original UDP code
+ * Jean-Paul Saman <jpsaman #_at_# m2x dot nl> - original UDP code
+ * Remi Denis-Courmont - original UDP code
+ * Natalie Landsberg <natalie.landsberg97 at gmail.com> - AMT support
+ * Wayne Brassem <wbrassem at rogers.com> - Added FQDN support
+ *
+ * This code is licensed to you under the GNU Lesser General Public License
+ * version 2.1 or later. You may not use this code except in compliance with
+ * the GNU Lesser General Public License.
+ * This code is not an official Juniper product.
+ *
+ * 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
+ ****************************************************************************/
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <errno.h>
+#include <ctype.h>
+#ifdef HAVE_ARPA_INET_H
+# include <arpa/inet.h>
+#endif
+
+#ifdef HAVE_SYS_SELECT_H
+# include <sys/select.h>
+#endif
+
+#ifdef HAVE_SYS_SOCKET_H
+# include <sys/socket.h>
+#endif
+
+#include <vlc_common.h>
+#include <vlc_demux.h>
+#include <vlc_plugin.h>
+#include <vlc_access.h>
+#include <vlc_network.h>
+#include <vlc_block.h>
+#include <vlc_interrupt.h>
+#include <vlc_url.h>
+
+#include "amt.h"
+
+#ifdef HAVE_POLL
+ #include <poll.h>
+#endif
+#ifdef HAVE_SYS_UIO_H
+ #include <sys/uio.h>
+#endif
+
+#define BUFFER_TEXT N_("Receive buffer")
+#define BUFFER_LONGTEXT N_("AMT receive buffer size (bytes)" )
+#define TIMEOUT_TEXT N_("Native multicast timeout (sec)")
+#define AMT_TIMEOUT_TEXT N_("AMT timeout (sec)")
+#define AMT_RELAY_ADDRESS N_("AMT relay (IP address or FQDN)")
+#define AMT_RELAY_ADDR_LONG N_("AMT relay anycast address, or specify the relay you want by address or fully qualified domain name")
+#define AMT_DEFAULT_RELAY N_("amt-relay.m2icast.net")
+
+static int Open (vlc_object_t *);
+static void Close (vlc_object_t *);
+
+/* Utility functions */
+static unsigned short get_checksum( unsigned short *buffer, int nLen );
+static void make_report( amt_igmpv3_membership_report_t *mr );
+static void make_ip_header( amt_ip_alert_t *p_ipHead );
+
+vlc_module_begin ()
+ set_shortname( N_("AMT" ) )
+ set_description( N_("AMT input") )
+ set_category( CAT_INPUT )
+ set_subcategory( SUBCAT_INPUT_ACCESS )
+
+ add_integer( "amt-timeout", 5, AMT_TIMEOUT_TEXT, NULL, true )
+ add_integer( "amt-native-timeout", 3, TIMEOUT_TEXT, NULL, true )
+ add_string( "amt-relay", AMT_DEFAULT_RELAY, AMT_RELAY_ADDRESS, AMT_RELAY_ADDR_LONG, true )
+
+ set_capability( "access", 0 )
+ add_shortcut( "amt" )
+
+ set_callbacks( Open, Close )
+vlc_module_end ()
+
+/*****************************************************************************
+ * Local prototypes
+ *****************************************************************************/
+static block_t *BlockUDP( stream_t *, bool * );
+static int Control( stream_t *, int, va_list );
+
+/*****************************************************************************
+ * Open: Open a connection to the multicast feed
+ *****************************************************************************/
+static int Open( vlc_object_t *p_this )
+{
+ stream_t *p_access = (stream_t*) p_this;
+ access_sys_t *sys = NULL;
+ struct addrinfo hints, *serverinfo = NULL;
+ struct sockaddr_in *server_addr;
+ char *psz_name = NULL, *saveptr, *psz_strtok_r, ip_buffer[INET_ADDRSTRLEN];
+ int i_bind_port = 1234, i_server_port = 0, VLC_ret = VLC_SUCCESS, res;
+ vlc_url_t url;
+
+ if( p_access->b_preparsing )
+ return VLC_EGENERIC;
+
+ /* Allocate the structure for holding AMT info and zeroize it */
+ sys = vlc_obj_calloc( p_this, 1, sizeof( *sys ) );
+ if( unlikely( sys == NULL ) )
+ return VLC_ENOMEM;
+
+ /* The standard MPEG-2 transport is 188 bytes. 7 packets fit into a standard 1500 byte Ethernet frame */
+ sys->mtu = 7 * 188;
+
+ /* Protective packet overflow buffer designed to accommodate jumbo Ethernet frames (beyond the standard 1500 byte frame) should they arrive unexpectedly */
+ sys->overflow_block = block_Alloc(65507 - sys->mtu);
+ if( unlikely( sys->overflow_block == NULL ) )
+ return VLC_ENOMEM;
+
+ p_access->p_sys = sys;
+
+ /* Set up p_access */
+ ACCESS_SET_CALLBACKS( NULL, BlockUDP, Control, NULL );
+
+ if( !p_access->psz_location )
+ return VLC_EGENERIC;
+
+ psz_name = strdup( p_access->psz_location );
+ if ( unlikely( psz_name == NULL ) )
+ return VLC_ENOMEM;
+
+ /* Parse psz_name syntax :
+ * [serveraddr[:serverport]][@[bindaddr]:[bindport]] */
+ if( vlc_UrlParse( &url, p_access->psz_url ) != 0 )
+ {
+ msg_Err( p_access, "Invalid URL: %s", p_access->psz_url );
+ VLC_ret = VLC_EGENERIC;
+ goto cleanup;
+ }
+
+ /* Determining the multicast source and group depends on the URL provided */
+ /* */
+ /* The address(es) in the URL can be in the form of IP address or FQDN */
+ /* By calling vlc_getaaddrinfo() you get it in IP form either way */
+ /* */
+ /* Case 1: amt://<source-ip-address>@<multicast-group-ip-address> */
+ /* */
+ /* sys->mcastSrc = <source-ip-address> */
+ /* sys->mcastSrcAddr = inet_pton( sys->mcastSrc ) */
+ /* */
+ /* sys->mcastGroup = <multicast-group-ip-address> */
+ /* sys->mcastGroupAddr = inet_pton( sys->mcastGroup ) */
+ /* */
+ /* Case 2: amt://<multicast-group-ip-address> */
+ /* */
+ /* sys->mcastSrc = MCAST_ANYCAST = "0.0.0.0" */
+ /* sys->mcastSrcAddr = inet_pton( sys->mcastSrc ) = 0 */
+ /* */
+ /* sys->mcastGroup = <multicast-group-ip-address> */
+ /* sys->mcastGroupAddr = inet_pton( sys->mcastGroup ) */
+ /* */
+
+ /* If UDP port provided then assign port to stream */
+ if( url.i_port > 0 )
+ i_bind_port = url.i_port;
+
+ msg_Dbg( p_access, "Opening multicast: %s:%d local=%s:%d", url.psz_host, i_server_port, url.psz_path, i_bind_port );
+
+ /* Initialize hints prior to call to vlc_getaddrinfo with either IP address or FQDN */
+ memset( &hints, 0, sizeof( hints ));
+ hints.ai_family = AF_INET; /* Setting to AF_UNSPEC accepts both IPv4 and IPv6 */
+ hints.ai_socktype = SOCK_DGRAM;
+
+ /* Retrieve list of multicast addresses matching the multicast group identifier */
+ res = vlc_getaddrinfo( url.psz_host, AMT_PORT, &hints, &serverinfo );
+
+ /* If an error returned print reason and exit */
+ if( res )
+ {
+ msg_Err( p_access, "Could not find multicast group %s, reason: %s", url.psz_host, gai_strerror(res) );
+ VLC_ret = VLC_EGENERIC;
+ goto cleanup;
+ }
+
+ /* Convert binary socket address to string */
+ server_addr = (struct sockaddr_in *) serverinfo->ai_addr;
+ inet_ntop(AF_INET, &(server_addr->sin_addr), ip_buffer, INET_ADDRSTRLEN);
+
+ /* Store the binary socket representation of multicast group address */
+ sys->mcastGroupAddr = *server_addr;
+
+ /* Release the allocated memory */
+ freeaddrinfo( serverinfo );
+ serverinfo = NULL;
+
+ /* Store string representation */
+ sys->mcastGroup = strdup( ip_buffer );
+ if( unlikely( sys->mcastGroup == NULL ) )
+ {
+ VLC_ret = VLC_ENOMEM;
+ goto cleanup;
+ }
+
+ msg_Dbg( p_access, "Setting multicast group address to %s", sys->mcastGroup);
+
+ /* Extract the source from the URL, or the multicast group when no source is provided */
+ if ( !( psz_strtok_r = strtok_r( psz_name, "@", &saveptr ) ) )
+ {
+ msg_Err( p_access, "Could not parse location %s", psz_name);
+ VLC_ret = VLC_EGENERIC;
+ goto cleanup;
+ }
+
+ /* Store the string representation */
+ sys->mcastSrc = strdup( psz_strtok_r );
+ if( unlikely( sys->mcastSrc == NULL ) )
+ {
+ VLC_ret = VLC_ENOMEM;
+ goto cleanup;
+ }
+
+ /* If strings are equal then no multicast source has been specified, so try anycast */
+ if( strcmp( url.psz_host, sys->mcastSrc ) == 0 )
+ {
+ free( sys->mcastSrc );
+ sys->mcastSrc = strdup(MCAST_ANYCAST);
+ sys->mcastSrcAddr.sin_addr.s_addr = 0;
+ msg_Dbg( p_access, "No multicast source address specified, trying ASM...");
+ }
+
+ /* retrieve list of source addresses matching the multicast source identifier */
+ res = vlc_getaddrinfo( sys->mcastSrc, AMT_PORT, &hints, &serverinfo );
+
+ /* If an error returned print reason and exit */
+ if( res )
+ {
+ msg_Err( p_access, "Could not find multicast source %s, reason: %s", sys->mcastSrc, gai_strerror(res) );
+ VLC_ret = VLC_EGENERIC;
+ goto cleanup;
+ }
+
+ /* Convert binary socket address to string */
+ server_addr = (struct sockaddr_in *) serverinfo->ai_addr;
+ inet_ntop(AF_INET, &(server_addr->sin_addr), ip_buffer, INET_ADDRSTRLEN);
+
+ /* Store the binary socket representation of multicast source address */
+ sys->mcastSrcAddr = *server_addr;
+
+ /* free the original source address buffer (IP or FQDN) and assign it just the IP address */
+ free( sys->mcastSrc );
+
+ /* Store string representation */
+ sys->mcastSrc = strdup( ip_buffer );
+ if( unlikely( sys->mcastSrc == NULL ) )
+ {
+ VLC_ret = VLC_ENOMEM;
+ goto cleanup;
+ }
+
+ msg_Dbg( p_access, "Setting multicast source address to %s", sys->mcastSrc);
+
+ /* Pull the AMT relay address from the settings */
+ sys->relay = var_InheritString( p_access, "amt-relay" );
+ if( unlikely( sys->relay == NULL ) )
+ {
+ msg_Err( p_access, "No relay anycast or unicast address specified." );
+ VLC_ret = VLC_EGENERIC;
+ goto cleanup;
+ }
+
+ msg_Dbg( p_access, "Addresses: mcastGroup: %s mcastSrc: %s relay: %s", \
+ sys->mcastGroup, sys->mcastSrc, sys->relay);
+
+ /* Native multicast file descriptor */
+ sys->fd = net_OpenDgram( p_access, sys->mcastGroup, i_bind_port,
+ sys->mcastSrc, i_server_port, IPPROTO_UDP );
+ if( sys->fd == -1 )
+ {
+ msg_Err( p_access, "cannot open socket" );
+ VLC_ret = VLC_EGENERIC;
+ goto cleanup;
+ }
+
+ sys->timeout = var_InheritInteger( p_access, "amt-native-timeout");
+ if( sys->timeout > 0)
+ sys->timeout *= 1000;
+
+ sys->amtTimeout = var_InheritInteger( p_access, "amt-timeout" );
+ if( sys->amtTimeout > 0)
+ sys->amtTimeout *= 1000;
+
+ sys->tryAMT = false;
+ sys->threadReady = false;
+
+cleanup: /* fall through */
+
+ /* release the allocated memory */
+ free( psz_name );
+ vlc_UrlClean( &url );
+ freeaddrinfo( serverinfo );
+
+ /* if an error occurred free the memory */
+ if ( VLC_ret != VLC_SUCCESS )
+ {
+ msg_Dbg( p_access, "Open(): Before free( sys-> sys->Addr ) #4" );
+ free( sys->mcastGroup );
+ free( sys->mcastSrc );
+ }
+
+ return VLC_ret;
+}
+
+/*****************************************************************************
+ * Close: Cancel thread and free data structures
+ *****************************************************************************/
+static void Close( vlc_object_t *p_this )
+{
+ stream_t *p_access = (stream_t*)p_this;
+ access_sys_t *sys = p_access->p_sys;
+
+ msg_Dbg( p_access, "Closing AMT plugin" );
+
+ /* If using AMT tunneling send leave message and free the relay addresses */
+ if ( sys->tryAMT )
+ {
+ /* Prepare socket options */
+ if( sys->mcastSrcAddr.sin_addr.s_addr )
+ amt_leaveSSM_group( p_access );
+ else
+ amt_leaveASM_group( p_access );
+
+ /* Send IGMP leave message */
+ amt_send_mem_update( p_access, sys->relayDisco, true );
+
+ free( sys->relay );
+ free( sys->relayDisco );
+ }
+
+ /* If overflow block allocated then free the memory */
+ if( sys->overflow_block )
+ block_Release( sys->overflow_block );
+
+ /* If membership thread spawned cancel it */
+ if( sys->threadReady )
+ {
+ msg_Dbg( p_access, "Canceling IGMP membership thread" );
+ sys->threadReady = false;
+ vlc_cancel( sys->updateThread );
+ vlc_join( sys->updateThread, NULL );
+ }
+
+ free( sys->mcastGroup );
+ free( sys->mcastSrc );
+
+ net_Close( sys->fd );
+ net_Close( sys->sAMT );
+ net_Close( sys->sQuery );
+
+ msg_Dbg( p_access, "Exiting AMT plugin" );
+}
+
+/*****************************************************************************
+ * Control: Define stream controls
+ *****************************************************************************/
+static int Control( stream_t *p_access, int i_query, va_list args )
+{
+ switch( i_query )
+ {
+ case STREAM_CAN_SEEK:
+ case STREAM_CAN_FASTSEEK:
+ case STREAM_CAN_PAUSE:
+ case STREAM_CAN_CONTROL_PACE:
+ *va_arg( args, bool * ) = false;
+ break;
+
+ case STREAM_GET_PTS_DELAY:
+ *va_arg( args, vlc_tick_t * ) =
+ VLC_TICK_FROM_MS(var_InheritInteger( p_access, "network-caching" ));
+ break;
+
+ default:
+ return VLC_EGENERIC;
+ }
+
+ return VLC_SUCCESS;
+}
+
+/*****************************************************************************
+ * BlockUDP: Responsible for returning the multicast payload
+ * BlockUDP: Several sections based upon the BlockUDP code in udp.c
+ *
+ * Default MTU based on number of MPEG-2 transports carried in a 1500 byte Ethernet frame
+ * however the code is able to receive jumbo Ethernet frames and then adjusts the MTU
+ *****************************************************************************/
+static block_t *BlockUDP(stream_t *p_access, bool *restrict eof)
+{
+ access_sys_t *sys = p_access->p_sys;
+ ssize_t len, shift = 0, tunnel = IP_HDR_LEN + UDP_HDR_LEN + AMT_HDR_LEN;
+
+ /* Allocate a packet buffer based on anticipated MTU */
+ block_t *pkt = block_Alloc(sys->mtu);
+ if ( unlikely( pkt == NULL ) )
+ return NULL;
+
+ /* Larger buffer for holding the UDP packet suitable for native or AMT tunneled multicast */
+ char *recvpkt = malloc( sys->mtu + tunnel );
+ if ( unlikely( recvpkt == NULL ) )
+ goto error;
+
+ /* Code snippet imported from BlockUDP() in udp.c */
+ /* Structure initialized to hold anticipated MTU buffer along with protective overflow buffer */
+ struct iovec iov[] = {{
+ .iov_base = recvpkt,
+ .iov_len = sys->mtu + tunnel,
+ },{
+ .iov_base = sys->overflow_block->p_buffer,
+ .iov_len = sys->overflow_block->i_buffer,
+ }};
+
+ /* References the two element array above to be passed into recvmsg */
+ struct msghdr msg = {
+ .msg_iov = iov,
+ .msg_iovlen = 2,
+ };
+
+ struct pollfd ufd[1];
+
+ if( sys->tryAMT )
+ ufd[0].fd = sys->sAMT; /* AMT tunneling file descriptor */
+ else
+ ufd[0].fd = sys->fd; /* Native multicast file descriptor */
+ ufd[0].events = POLLIN;
+
+ switch (vlc_poll_i11e(ufd, 1, sys->timeout))
+ {
+ case 0:
+ if( !sys->tryAMT )
+ {
+ msg_Err(p_access, "Native multicast receive time-out");
+ if( !open_amt_tunnel( p_access ) )
+ goto error;
+ break;
+ }
+ else
+ {
+ *eof = true;
+ }
+ /* fall through */
+ case -1:
+ goto error;
+ }
+
+ /* If using AMT tunneling perform basic checks and point to beginning of the payload */
+ if( sys->tryAMT )
+ {
+ len = recvmsg( sys->sAMT, &msg, 0 );
+
+ /* Check for the integrity of the received AMT packet */
+ if( len < 0 || recvpkt[0] != AMT_MULT_DATA )
+ goto error;
+
+ /* Set the offet to the first byte of the payload */
+ shift += tunnel;
+
+ /* If the length received is less than the AMT tunnel header then it's truncated */
+ if( len < tunnel )
+ {
+ msg_Err(p_access, "%zd bytes packet truncated (MTU was %zu)",
+ len, sys->mtu);
+ pkt->i_flags |= BLOCK_FLAG_CORRUPTED;
+ }
+
+ /* Otherwise subtract the length of the AMT header from the packets received */
+ else
+ {
+ len -= tunnel;
+ }
+ }
+
+ /* Otherwise pull native multicast */
+ else
+ {
+ len = recvmsg(sys->fd, &msg, 0);
+ }
+
+ /* If the payload length is greater than the MTU then the overflow buffer was utilized */
+ if ( unlikely( len > sys->mtu ) )
+ {
+ msg_Warn(p_access, "%zd bytes packet received (MTU was %zu), adjusting mtu",
+ len, sys->mtu);
+
+ block_t *gather_block = sys->overflow_block;
+
+ /* Allocate a new overflow buffer based on the received payload length */
+ sys->overflow_block = block_Alloc(65507 - len);
+
+ /* Set number of bytes consumed in the overflow block */
+ gather_block->i_buffer = len - sys->mtu;
+
+ /* Chain the anticipated packet and overflow buffers, copy into a single buffer and free the chain */
+ pkt->p_next = gather_block;
+ pkt = block_ChainGather( pkt );
+
+ /* Adjust the anticipated MTU to match the size received */
+ sys->mtu = len;
+ }
+
+ /* Otherwise the allocated buffer is sufficient to copy the payload into */
+ else
+ {
+ memcpy( pkt->p_buffer, &recvpkt[shift], len );
+ }
+
+ pkt->i_buffer = len;
+
+ free( recvpkt );
+ return pkt;
+
+error:
+ free( recvpkt );
+ free( pkt );
+ return NULL;
+}
+
+/*****************************************************************************
+ * open_amt_tunnel: Create an AMT tunnel to the AMT relay
+ *****************************************************************************/
+bool open_amt_tunnel( stream_t *p_access )
+{
+ struct addrinfo hints, *serverinfo, *server;
+ access_sys_t *sys = p_access->p_sys;
+
+ memset( &hints, 0, sizeof( hints ));
+ hints.ai_family = AF_INET; /* Setting to AF_UNSPEC accepts both IPv4 and IPv6 */
+ hints.ai_socktype = SOCK_DGRAM;
+
+ msg_Dbg( p_access, "Attempting AMT to %s...", sys->relay);
+ sys->tryAMT = true;
+
+ /* Retrieve list of addresses matching the AMT relay */
+ int res = vlc_getaddrinfo( sys->relay, AMT_PORT, &hints, &serverinfo );
+
+ /* If an error returned print reason and exit */
+ if( res )
+ {
+ msg_Err( p_access, "Could not find relay %s, reason: %s", sys->relay, gai_strerror(res) );
+ goto error;
+ }
+
+ /* Iterate through the list of sockets to find one that works */
+ for (server = serverinfo; server != NULL; server = server->ai_next)
+ {
+ struct sockaddr_in *server_addr = (struct sockaddr_in *) server->ai_addr;
+ char relay_ip[INET_ADDRSTRLEN];
+
+ /* Convert to binary representation */
+ inet_ntop(AF_INET, &(server_addr->sin_addr), relay_ip, INET_ADDRSTRLEN);
+
+ /* Store string representation */
+ sys->relayDisco = strdup( relay_ip );
+ if( unlikely( sys->relayDisco == NULL ) )
+ {
+ goto error;
+ }
+
+ msg_Dbg( p_access, "Trying AMT Server: %s", sys->relayDisco);
+
+ /* Store the binary representation */
+ sys->relayDiscoAddr.sin_addr = server_addr->sin_addr;
+
+ /* If can't open socket try any others in list */
+ if( amt_sockets_init( p_access ) != 0 )
+ msg_Err( p_access, "Error initializing socket to %s", relay_ip );
+
+ /* Otherwise negotiate with AMT relay and confirm you can pull a UDP packet */
+ else
+ {
+ amt_send_relay_discovery_msg( p_access, relay_ip );
+ msg_Dbg( p_access, "Sent relay AMT discovery message to %s", relay_ip );
+
+ if( !amt_rcv_relay_adv( p_access ) )
+ {
+ msg_Err( p_access, "Error receiving AMT relay advertisement msg from %s, skipping", relay_ip );
+ goto error;
+ }
+ msg_Dbg( p_access, "Received AMT relay advertisement from %s", relay_ip );
+
+ amt_send_relay_request( p_access, relay_ip );
+ msg_Dbg( p_access, "Sent AMT relay request message to %s", relay_ip );
+
+ if( !amt_rcv_relay_mem_query( p_access ) )
+ {
+ msg_Err( p_access, "Could not receive AMT relay membership query from %s, reason: %s", relay_ip, vlc_strerror(errno));
+ goto error;
+ }
+ msg_Dbg( p_access, "Received AMT relay membership query from %s", relay_ip );
+
+ /* If single source multicast send SSM join */
+ if( sys->mcastSrcAddr.sin_addr.s_addr )
+ {
+ if( amt_joinSSM_group( p_access ) != 0 )
+ {
+ msg_Err( p_access, "Error joining SSM %s", vlc_strerror(errno) );
+ goto error;
+ }
+ msg_Dbg( p_access, "Joined SSM src: %s group: %s", sys->mcastSrc, sys->mcastGroup );
+ }
+
+ /* If any source multicast send ASM join */
+ else {
+ if( amt_joinASM_group( p_access ) != 0 )
+ {
+ msg_Err( p_access, "Error joining ASM %s", vlc_strerror(errno) );
+ goto error;
+ }
+ msg_Dbg( p_access, "Joined ASM group: %s", sys->mcastGroup );
+ }
+
+ bool eof=false;
+ block_t *pkt;
+
+ /* Confirm that you can pull a UDP packet from the socket */
+ if ( !(pkt = BlockUDP( p_access, &eof )) )
+ msg_Err( p_access, "Unable to receive UDP packet from AMT relay %s for multicast group %s", relay_ip, sys->mcastGroup );
+ else
+ {
+ block_Release( pkt );
+ msg_Dbg( p_access, "Got UDP packet from multicast group %s via AMT relay %s, continuing...", sys->mcastGroup, relay_ip );
+ break; /* found an active server sending UDP packets, so exit loop */
+ }
+ }
+ }
+
+ /* if server is NULL then no AMT relay is responding */
+ if (server == NULL)
+ {
+ msg_Err( p_access, "No AMT servers responding" );
+ goto error;
+ }
+
+ sys->queryTime = vlc_tick_now() / CLOCK_FREQ;
+
+ /* release the allocated memory */
+ freeaddrinfo( serverinfo );
+ return true;
+
+error:
+ /* release the allocated memory */
+ freeaddrinfo( serverinfo );
+ sys->threadReady = false;
+ return false;
+}
+
+/**
+ * Calculate checksum
+ * */
+unsigned short get_checksum( unsigned short *buffer, int nLen )
+{
+ int nleft = nLen;
+ int sum = 0;
+ unsigned short *w = buffer;
+ unsigned short answer = 0;
+
+ while (nleft > 1)
+ {
+ sum += *w++;
+ nleft -= 2;
+ }
+ if (nleft == 1)
+ {
+ *(unsigned char*)(&answer) = *(unsigned char*)w;
+ sum += answer;
+ }
+ sum = (sum >> 16) + (sum & 0xffff);
+ answer = ~sum;
+ return (answer);
+}
+
+/**
+ * Make IGMP Membership report
+ * */
+void make_report( amt_igmpv3_membership_report_t *mr )
+{
+ mr->type = AMT_IGMPV3_MEMBERSHIP_REPORT_TYPEID;
+ mr->resv = 0;
+ mr->checksum = 0;
+ mr->resv2 = 0;
+ mr->nGroupRecord = htons(1);
+}
+
+/**
+ * Make IP header
+ * */
+void make_ip_header( amt_ip_alert_t *p_ipHead )
+{
+ p_ipHead->ver_ihl = 0x46;
+ p_ipHead->tos = 0xc0;
+ p_ipHead->tot_len = htons( IP_HDR_IGMP_LEN + IGMP_REPORT_LEN );
+ p_ipHead->id = 0x00;
+ p_ipHead->frag_off = 0x0000;
+ p_ipHead->ttl = 0x01;
+ p_ipHead->protocol = 0x02;
+ p_ipHead->check = 0;
+ p_ipHead->srcAddr = INADDR_ANY;
+ p_ipHead->options = 0x0000;
+}
+
+/** Create relay discovery socket, query socket, UDP socket and
+ * fills in relay anycast address for discovery
+ * return 0 if successful, -1 if not
+ */
+int amt_sockets_init( stream_t *p_access )
+{
+ struct sockaddr_in rcvAddr;
+ access_sys_t *sys = p_access->p_sys;
+ memset( &rcvAddr, 0, sizeof(struct sockaddr_in) );
+ int enable = 0, res = 0;
+
+ /* Relay anycast address for discovery */
+ sys->relayDiscoAddr.sin_family = AF_INET;
+ sys->relayDiscoAddr.sin_port = htons( AMT_PORT );
+
+ /* create UDP socket */
+ sys->sAMT = vlc_socket( AF_INET, SOCK_DGRAM, IPPROTO_UDP, true );
+ if( sys->sAMT == -1 )
+ {
+ msg_Err( p_access, "Failed to create UDP socket" );
+ goto error;
+ }
+
+ res = setsockopt(sys->sAMT, IPPROTO_IP, IP_PKTINFO, &enable, sizeof(enable));
+ if(res < 0)
+ {
+ msg_Err( p_access, "Couldn't set socket options for IPPROTO_IP, IP_PKTINFO\n %s", vlc_strerror(errno));
+ goto error;
+ }
+
+ res = setsockopt(sys->sAMT, SOL_SOCKET, SO_REUSEADDR, &enable, sizeof(enable));
+ if(res < 0)
+ {
+ msg_Err( p_access, "Couldn't make socket reusable");
+ goto error;
+ }
+
+ rcvAddr.sin_family = AF_INET;
+ rcvAddr.sin_port = htons( 0 );
+ rcvAddr.sin_addr.s_addr = INADDR_ANY;
+
+ if( bind(sys->sAMT, (struct sockaddr *)&rcvAddr, sizeof(rcvAddr) ) != 0 )
+ {
+ msg_Err( p_access, "Failed to bind UDP socket error: %s", vlc_strerror(errno) );
+ goto error;
+ }
+
+ sys->sQuery = vlc_socket( AF_INET, SOCK_DGRAM, IPPROTO_UDP, true );
+ if( sys->sQuery == -1 )
+ {
+ msg_Err( p_access, "Failed to create query socket" );
+ goto error;
+ }
+
+ /* bind socket to local address */
+ sys->stLocalAddr.sin_family = AF_INET;
+ sys->stLocalAddr.sin_port = htons( 0 );
+ sys->stLocalAddr.sin_addr.s_addr = INADDR_ANY;
+
+ if( bind(sys->sQuery, (struct sockaddr *)&sys->stLocalAddr, sizeof(struct sockaddr) ) != 0 )
+ {
+ msg_Err( p_access, "Failed to bind query socket" );
+ goto error;
+ }
+
+ sys->stSvrAddr.sin_family = AF_INET;
+ sys->stSvrAddr.sin_port = htons( 9124 );
+ res = inet_pton( AF_INET, LOCAL_LOOPBACK, &sys->stSvrAddr.sin_addr );
+ if( res == 0 )
+ {
+ msg_Err( p_access, "Could not convert loopback address" );
+ goto error;
+ }
+
+ return 0;
+
+error:
+ net_Close( sys->sAMT );
+ net_Close( sys->sQuery );
+ return -1;
+}
+
+/**
+ * Send a relay discovery message, before 3-way handshake
+ * */
+void amt_send_relay_discovery_msg( stream_t *p_access, char *relay_ip )
+{
+ char chaSendBuffer[AMT_DISCO_MSG_LEN];
+ unsigned int ulNonce;
+ int nRet;
+ access_sys_t *sys = p_access->p_sys;
+
+ /* initialize variables */
+ memset( chaSendBuffer, 0, sizeof(chaSendBuffer) );
+ ulNonce = 0;
+ nRet = 0;
+
+ /*
+ * create AMT discovery message format
+ * +---------------------------------------------------+
+ * | Msg Type(1Byte)| Reserved (3 byte)| nonce (4byte) |
+ * +---------------------------------------------------+
+ */
+
+ chaSendBuffer[0] = AMT_RELAY_DISCO;
+ chaSendBuffer[1] = 0;
+ chaSendBuffer[2] = 0;
+ chaSendBuffer[3] = 0;
+
+ /* create nonce and copy into send buffer */
+ srand( (unsigned int)time(NULL) );
+ ulNonce = htonl( rand() );
+ memcpy( (void*)&chaSendBuffer[4], (void*)&ulNonce, sizeof(ulNonce) );
+ sys->glob_ulNonce = ulNonce;
+
+ /* send it */
+ nRet = sendto( sys->sAMT, chaSendBuffer, sizeof(chaSendBuffer), 0,\
+ (struct sockaddr *)&sys->relayDiscoAddr, sizeof(struct sockaddr) );
+
+ if( nRet < 0)
+ msg_Err( p_access, "Sendto failed to %s with error %d.", relay_ip, errno);
+}
+
+/**
+ * Send relay request message, stage 2 of handshake
+ * */
+void amt_send_relay_request( stream_t *p_access, char *relay_ip )
+{
+ char chaSendBuffer[AMT_REQUEST_MSG_LEN];
+ uint32_t ulNonce;
+ int nRet;
+ int nRetry;
+ access_sys_t *sys = p_access->p_sys;
+
+ memset( chaSendBuffer, 0, sizeof(chaSendBuffer) );
+
+ ulNonce = 0;
+ nRet = 0;
+ nRetry = 0;
+
+ /*
+ * create AMT request message format
+ * +-----------------------------------------------------------------+
+ * | Msg Type(1Byte)| Reserved(1byte)|P flag(1byte)|Reserved (2 byte)|
+ * +-----------------------------------------------------------------+
+ * | nonce (4byte) |
+ * +-----------------------------------------------------------------+
+ *
+ * The P flag is set to indicate which group membership protocol the
+ * gateway wishes the relay to use in the Membership Query response:
+
+ * Value Meaning
+
+ * 0 The relay MUST respond with a Membership Query message that
+ * contains an IPv4 packet carrying an IGMPv3 General Query
+ * message.
+ * 1 The relay MUST respond with a Membership Query message that
+ * contains an IPv6 packet carrying an MLDv2 General Query
+ * message.
+ *
+ */
+
+ chaSendBuffer[0] = AMT_REQUEST;
+ chaSendBuffer[1] = 0;
+ chaSendBuffer[2] = 0;
+ chaSendBuffer[3] = 0;
+
+ ulNonce = sys->glob_ulNonce;
+ memcpy( (void*)&chaSendBuffer[4], (void*)&ulNonce, sizeof(uint32_t) );
+
+ nRet = send( sys->sAMT, chaSendBuffer, sizeof(chaSendBuffer), 0 );
+
+ if( nRet < 0 )
+ msg_Err(p_access, "Error sending relay request to %s error: %s", relay_ip, vlc_strerror(errno) );
+}
+
+/*
+* create AMT request message format
+* +----------------------------------------------------------------------------------+
+* | Msg Type(1 byte)| Reserved (1 byte)| MAC (6 byte)| nonce (4 byte) | IGMP packet |
+* +----------------------------------------------------------------------------------+
+*/
+void amt_send_mem_update( stream_t *p_access, char *relay_ip, bool leave)
+{
+ int sendBufSize = IP_HDR_IGMP_LEN + MAC_LEN + NONCE_LEN + AMT_HDR_LEN;
+ char pSendBuffer[ sendBufSize + IGMP_REPORT_LEN ];
+ uint32_t ulNonce = 0;
+ access_sys_t *sys = p_access->p_sys;
+
+ memset( &pSendBuffer, 0, sizeof(pSendBuffer) );
+
+ pSendBuffer[0] = AMT_MEM_UPD;
+
+ /* copy relay MAC response */
+ memcpy( (void*)&pSendBuffer[2], (void*)sys->relay_mem_query_msg.uchaMAC, MAC_LEN );
+
+ /* copy nonce */
+ ulNonce = ntohl(sys->glob_ulNonce);
+ memcpy( (void*)&pSendBuffer[8], (void*)&ulNonce, NONCE_LEN );
+
+ /* make IP header for IGMP packet */
+ amt_ip_alert_t p_ipHead;
+ memset( &p_ipHead, 0, IP_HDR_IGMP_LEN );
+ make_ip_header( &p_ipHead );
+
+ struct sockaddr_in temp;
+ inet_pton( AF_INET, MCAST_ALLHOSTS, &(temp.sin_addr) );
+ p_ipHead.destAddr = temp.sin_addr.s_addr;
+ p_ipHead.check = get_checksum( (unsigned short*)&p_ipHead, IP_HDR_IGMP_LEN );
+
+ amt_igmpv3_groupRecord_t groupRcd;
+ groupRcd.auxDatalen = 0;
+ groupRcd.ssm = sys->mcastGroupAddr.sin_addr.s_addr;
+
+ if( sys->mcastSrcAddr.sin_addr.s_addr )
+ {
+ groupRcd.type = leave ? AMT_IGMP_BLOCK:AMT_IGMP_INCLUDE;
+ groupRcd.nSrc = htons(1);
+ groupRcd.srcIP[0] = sys->mcastSrcAddr.sin_addr.s_addr;
+
+ } else {
+ groupRcd.type = leave ? AMT_IGMP_INCLUDE_CHANGE:AMT_IGMP_EXCLUDE_CHANGE;
+ groupRcd.nSrc = htons(0);
+ }
+
+ /* make IGMP membership report */
+ amt_igmpv3_membership_report_t p_igmpMemRep;
+ make_report( &p_igmpMemRep );
+
+ memcpy((void *)&p_igmpMemRep.grp[0], (void *)&groupRcd, (int)sizeof(groupRcd) );
+ p_igmpMemRep.checksum = get_checksum( (unsigned short*)&p_igmpMemRep, IGMP_REPORT_LEN );
+
+ amt_membership_update_msg_t memUpdateMsg;
+ memset((void*)&memUpdateMsg, 0, sizeof(memUpdateMsg));
+ memcpy((void*)&memUpdateMsg.ipHead, (void*)&p_ipHead, sizeof(p_ipHead) );
+ memcpy((void*)&memUpdateMsg.memReport, (void*)&p_igmpMemRep, sizeof(p_igmpMemRep) );
+
+ memcpy( (void*)&pSendBuffer[12], (void*)&memUpdateMsg, sizeof(memUpdateMsg) );
+
+ send( sys->sAMT, pSendBuffer, sizeof(pSendBuffer), 0 );
+
+ msg_Dbg( p_access, "AMT relay membership report sent to %s", relay_ip );
+}
+
+/**
+ * Receive relay advertisement message
+ *
+ *
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | V=0 |Type=2 | Reserved |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Discovery Nonce |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | |
+ * ~ Relay Address (IPv4 or IPv6) ~
+ * | |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * */
+bool amt_rcv_relay_adv( stream_t *p_access )
+{
+ char pkt[RELAY_ADV_MSG_LEN];
+ access_sys_t *sys = p_access->p_sys;
+
+ memset( &pkt, 0, RELAY_ADV_MSG_LEN );
+
+ struct pollfd ufd[1];
+
+ ufd[0].fd = sys->sAMT;
+ ufd[0].events = POLLIN;
+
+ switch( vlc_poll_i11e(ufd, 1, sys->timeout) )
+ {
+ case 0:
+ msg_Err(p_access, "AMT relay advertisement receive time-out");
+ /* fall through */
+ case -1:
+ return false;
+ }
+
+ struct sockaddr temp;
+ uint32_t temp_size = sizeof( struct sockaddr );
+ ssize_t len = recvfrom( sys->sAMT, &pkt, RELAY_ADV_MSG_LEN, 0, &temp, &temp_size );
+
+ if (len < 0)
+ {
+ msg_Err(p_access, "Received message length less than zero");
+ return false;
+ }
+
+ memcpy( (void*)&sys->relay_adv_msg.type, &pkt[0], MSG_TYPE_LEN );
+ if( sys->relay_adv_msg.type != AMT_RELAY_ADV )
+ {
+ msg_Err( p_access, "Received message not an AMT relay advertisement, ignoring. ");
+ return false;
+ }
+
+ memcpy( (void*)&sys->relay_adv_msg.ulRcvNonce, &pkt[NONCE_LEN], NONCE_LEN );
+ if( sys->glob_ulNonce != sys->relay_adv_msg.ulRcvNonce )
+ {
+ msg_Err( p_access, "Discovery nonces differ! currNonce:%x rcvd%x", sys->glob_ulNonce, ntohl(sys->relay_adv_msg.ulRcvNonce) );
+ return false;
+ }
+
+ memcpy( (void*)&sys->relay_adv_msg.ipAddr, &pkt[8], 4 );
+
+ memset( &sys->relayAddr, 0, sizeof(sys->relayAddr) );
+ sys->relayAddr.sin_family = AF_INET;
+ sys->relayAddr.sin_addr.s_addr = sys->relay_adv_msg.ipAddr;
+ sys->relayAddr.sin_port = htons( AMT_PORT );
+
+ int nRet = connect( sys->sAMT, (struct sockaddr *)&sys->relayAddr, sizeof(sys->relayAddr) );
+ if( nRet < 0 )
+ {
+ msg_Err( p_access, "Error connecting AMT UDP socket: %s", vlc_strerror(errno) );
+ return false;
+ }
+
+ return true;
+}
+
+/**
+ * Receive relay membership query message
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ | V=0 |Type=4 | Reserved |L|G| Response MAC |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
+ | |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ | Request Nonce |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ | |
+ | Encapsulated General Query Message |
+ ~ IPv4:IGMPv3(Membership Query) ~
+ | IPv6:MLDv2(Listener Query) |
+ | |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ | Gateway Port Number | |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
+ | |
+ + +
+ | Gateway IP Address (IPv4 or IPv6) |
+ + +
+ | |
+ + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ | |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+bool amt_rcv_relay_mem_query( stream_t *p_access )
+{
+ char pkt[RELAY_QUERY_MSG_LEN];
+ memset( &pkt, 0, RELAY_QUERY_MSG_LEN );
+ struct pollfd ufd[1];
+ access_sys_t *sys = p_access->p_sys;
+
+ ufd[0].fd = sys->sAMT;
+ ufd[0].events = POLLIN;
+
+ switch( vlc_poll_i11e(ufd, 1, sys->timeout) )
+ {
+ case 0:
+ msg_Err(p_access, "AMT relay membership query receive time-out");
+ /* fall through */
+ case -1:
+ return false;
+ }
+
+ ssize_t len = recv( sys->sAMT, &pkt, RELAY_QUERY_MSG_LEN, 0 );
+
+ if (len < 0)
+ {
+ msg_Err(p_access, "length less than zero");
+ return false;
+ }
+
+ memcpy( (void*)&sys->relay_mem_query_msg.type, &pkt[0], MSG_TYPE_LEN );
+ /* pkt[1] is reserved */
+ memcpy( (void*)&sys->relay_mem_query_msg.uchaMAC[0], &pkt[AMT_HDR_LEN], MAC_LEN );
+ memcpy( (void*)&sys->relay_mem_query_msg.ulRcvedNonce, &pkt[AMT_HDR_LEN + MAC_LEN], NONCE_LEN );
+ if( sys->relay_mem_query_msg.ulRcvedNonce != sys->glob_ulNonce )
+ {
+ msg_Warn( p_access, "Nonces are different rcvd: %x glob: %x", sys->relay_mem_query_msg.ulRcvedNonce, sys->glob_ulNonce );
+ return false;
+ }
+
+ sys->glob_ulNonce = ntohl(sys->relay_mem_query_msg.ulRcvedNonce);
+
+ int shift = AMT_HDR_LEN + MAC_LEN + NONCE_LEN;
+ memcpy( (void*)&sys->relay_ip_hdr, (void*)&pkt[shift], IP_HDR_IGMP_LEN );
+
+ shift += IP_HDR_IGMP_LEN;
+ sys->relay_igmp_query.type = pkt[shift];
+ shift++;
+ sys->relay_igmp_query.max_resp_code = pkt[shift];
+ shift++;
+ memcpy( (void*)&sys->relay_igmp_query.checksum, &pkt[shift], 2 );
+ shift += 2;
+ memcpy( (void*)&sys->relay_igmp_query.ssmIP, &pkt[shift], 4 );
+ shift += 4;
+ sys->relay_igmp_query.s_qrv = pkt[shift];
+ shift++;
+ if( (int)pkt[shift] == 0 )
+ sys->relay_igmp_query.qqic = 125;
+ else if( (int)pkt[shift] < 128 )
+ sys->relay_igmp_query.qqic = pkt[shift];
+ else {
+ int qqic;
+ qqic = ((pkt[shift]&0x0f) + 0x10) << (((pkt[shift] >> 4)&0x07) + 3);
+ sys->relay_igmp_query.qqic = qqic;
+ }
+
+ shift++;
+ memcpy( (void*)&sys->relay_igmp_query.nSrc, &pkt[shift], 2 );
+ if( sys->relay_igmp_query.nSrc != 0 )
+ {
+ shift += 2;
+ memcpy( (void*)&sys->relay_igmp_query.srcIP, &pkt[shift], 4 );
+ }
+
+ /* if a membership thread exists cancel it */
+ if( sys->threadReady )
+ {
+ msg_Dbg( p_access, "Canceling existing AMT relay membership update thread");
+
+ sys->threadReady = false;
+ vlc_cancel( sys->updateThread );
+ vlc_join( sys->updateThread, NULL );
+ }
+
+ msg_Dbg( p_access, "Spawning AMT relay membership update thread");
+
+ if( vlc_clone( &sys->updateThread, amt_mem_upd, p_access, VLC_THREAD_PRIORITY_LOW) )
+ {
+ msg_Err( p_access, "Could not create AMT relay membership update thread" );
+ return false;
+ }
+
+ /* set theadReady to true, thread will send periodic membership updates until false */
+ sys->threadReady = true;
+ return true;
+}
+
+/**
+ * Join SSM group based on input addresses, or use the defaults
+ * */
+int amt_joinSSM_group( stream_t *p_access )
+{
+ struct ip_mreq_source imr;
+ access_sys_t *sys = p_access->p_sys;
+
+ imr.imr_multiaddr.s_addr = sys->mcastGroupAddr.sin_addr.s_addr;
+ imr.imr_sourceaddr.s_addr = sys->mcastSrcAddr.sin_addr.s_addr;
+ imr.imr_interface.s_addr = INADDR_ANY;
+
+ return setsockopt( sys->sAMT, IPPROTO_IP, IP_ADD_SOURCE_MEMBERSHIP, (char *)&imr, sizeof(imr) );
+}
+
+int amt_joinASM_group( stream_t *p_access )
+{
+ struct ip_mreq imr;
+ access_sys_t *sys = p_access->p_sys;
+
+ imr.imr_multiaddr.s_addr = sys->mcastGroupAddr.sin_addr.s_addr;
+ imr.imr_interface.s_addr = INADDR_ANY;
+
+ return setsockopt( sys->sAMT, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char *)&imr, sizeof(imr) );
+}
+
+/**
+ * Leave SSM group that was joined earlier.
+ * */
+int amt_leaveSSM_group( stream_t *p_access )
+{
+ struct ip_mreq_source imr;
+ access_sys_t *sys = p_access->p_sys;
+
+ imr.imr_multiaddr.s_addr = sys->mcastGroupAddr.sin_addr.s_addr;
+ imr.imr_sourceaddr.s_addr = sys->mcastSrcAddr.sin_addr.s_addr;
+ imr.imr_interface.s_addr = INADDR_ANY;
+
+ return setsockopt( sys->sAMT, IPPROTO_IP, IP_DROP_SOURCE_MEMBERSHIP, (char *)&imr, sizeof(imr) );
+}
+
+/**
+ * Leave ASM group that was joined earlier.
+ * */
+int amt_leaveASM_group( stream_t *p_access )
+{
+ struct ip_mreq imr;
+ access_sys_t *sys = p_access->p_sys;
+
+ imr.imr_multiaddr.s_addr = sys->mcastGroupAddr.sin_addr.s_addr;
+ imr.imr_interface.s_addr = INADDR_ANY;
+
+ return setsockopt( sys->sAMT, IPPROTO_IP, IP_DROP_MEMBERSHIP, (char *)&imr, sizeof(imr) );
+}
+
+/* A thread is spawned since IGMP membership updates need to issued periodically in order to continue to receive multicast */
+/* Simple timers are not suitable for this requirement since the parent is otherwise occupied in receiving UDP packet flow */
+void *amt_mem_upd( void *data )
+{
+ stream_t *p_access = (stream_t*) data;
+ access_sys_t *sys = p_access->p_sys;
+
+ msg_Dbg( p_access, "AMT relay membership update thread started" );
+
+ /* thread sends periodic AMT membership updates until Close() which clears sys->threadReady and terminates thread */
+ while ( sys->threadReady )
+ {
+ amt_send_mem_update( p_access, sys->relayDisco, false );
+ vlc_tick_sleep( (vlc_tick_t)sys->relay_igmp_query.qqic * CLOCK_FREQ );
+ }
+
+ return NULL;
+}
diff --git a/modules/access/amt.h b/modules/access/amt.h
new file mode 100644
index 0000000000..f2ebdc2f90
--- /dev/null
+++ b/modules/access/amt.h
@@ -0,0 +1,219 @@
+/*****************************************************************************
+ * @file amt.h
+ * @brief AMT access module structs
+ *
+ * Some of this code was pulled from or based off Cisco's open-source
+ * SSMAMTtools repo.
+ * Copyright (c) Juniper Networks, Inc., 2018 - 2018. All rights reserved.
+ *
+ * This code is licensed to you under the GNU Lesser General Public License
+ * version 2.1 or later. You may not use this code except in compliance with
+ * the GNU Lesser General Public License.
+ * This code is not an official Juniper product.
+ *
+ * Authors: Natalie Landsberg <nlandsberg at juniper.net>
+ * Wayne Brassem <wbrassem at rogers.com>
+ *
+ * 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
+ ****************************************************************************/
+
+/*****************************************************************************
+ * Various Lengths of Msgs or Hdrs
+ *****************************************************************************/
+#define MAC_LEN 6 /* length of generated MAC in bytes */
+#define NONCE_LEN 4 /* length of nonce in bytes */
+
+#define MSG_TYPE_LEN 1 /* length of msg type */
+#define RELAY_QUERY_MSG_LEN 48 /* total length of relay query */
+#define RELAY_ADV_MSG_LEN 12 /* length of relay advertisement message */
+#define IGMP_QUERY_LEN 24 /* length of encapsulated IGMP query message */
+#define IGMP_REPORT_LEN 20
+#define AMT_HDR_LEN 2 /* length of AMT header on a packet */
+#define IP_HDR_LEN 20 /* length of standard IP header */
+#define IP_HDR_IGMP_LEN 24 /* length of IP header with an IGMP report */
+#define UDP_HDR_LEN 8 /* length of standard UDP header */
+#define AMT_REQUEST_MSG_LEN 9
+#define AMT_DISCO_MSG_LEN 8
+
+/*****************************************************************************
+ * Different AMT Message Types
+ *****************************************************************************/
+#define AMT_RELAY_DISCO 1 /* relay discovery */
+#define AMT_RELAY_ADV 2 /* relay advertisement */
+#define AMT_REQUEST 3 /* request */
+#define AMT_MEM_QUERY 4 /* membership query */
+#define AMT_MEM_UPD 5 /* membership update */
+#define AMT_MULT_DATA 6 /* multicast data */
+#define AMT_TEARDOWN 7 /* teardown (not currently supported) */
+
+/*****************************************************************************
+ * Different IGMP Message Types
+ *****************************************************************************/
+#define AMT_IGMPV3_MEMBERSHIP_QUERY_TYPEID 0x11
+#define AMT_IGMPV3_MEMBERSHIP_REPORT_TYPEID 0x22
+/* IGMPv2, interoperability */
+#define AMT_IGMPV1_MEMBERSHIP_REPORT_TYPEID 0x12
+#define AMT_IGMPV2_MEMBERSHIP_REPORT_TYPEID 0x16
+#define AMT_IGMPV2_MEMBERSHIP_LEAVE_TYPEID 0x17
+
+#define AMT_IGMP_INCLUDE 0x01
+#define AMT_IGMP_EXCLUDE 0x02
+#define AMT_IGMP_INCLUDE_CHANGE 0x03
+#define AMT_IGMP_EXCLUDE_CHANGE 0x04
+#define AMT_IGMP_ALLOW 0x05
+#define AMT_IGMP_BLOCK 0x06
+
+#define MCAST_ANYCAST "0.0.0.0"
+#define MCAST_ALLHOSTS "224.0.0.22"
+#define LOCAL_LOOPBACK "127.0.0.1"
+#define AMT_PORT 2268
+
+#define DEFAULT_MTU (1500u - (20 + 8))
+
+typedef struct access_sys_t access_sys_t;
+
+/* IPv4 Header Format */
+typedef struct _amt_ip {
+ uint8_t ver_ihl;
+ uint8_t tos;
+ uint16_t tot_len;
+ uint16_t id;
+ uint16_t frag_off;
+ uint8_t ttl;
+ uint8_t protocol;
+ uint16_t check;
+ uint32_t srcAddr;
+ uint32_t destAddr;
+} amt_ip_t;
+
+/* IPv4 Header Format with options field */
+typedef struct _amt_ip_alert {
+ uint8_t ver_ihl;
+ uint8_t tos;
+ uint16_t tot_len;
+ uint16_t id;
+ uint16_t frag_off;
+ uint8_t ttl;
+ uint8_t protocol;
+ uint16_t check;
+ uint32_t srcAddr;
+ uint32_t destAddr;
+ uint32_t options;
+} amt_ip_alert_t;
+
+/* IGMPv3 Group Record Format (RFC3376) */
+typedef struct _amt_igmpv3_groupRecord {
+ uint8_t type;
+ uint8_t auxDatalen;
+ uint16_t nSrc;
+ uint32_t ssm;
+ uint32_t srcIP[1];
+} amt_igmpv3_groupRecord_t;
+
+/* IGMPv3 Membership Report Format (RFC3376) */
+typedef struct _amt_igmpv3_membership_report {
+ uint8_t type;
+ uint8_t resv;
+ uint16_t checksum;
+ uint16_t resv2;
+ uint16_t nGroupRecord;
+ amt_igmpv3_groupRecord_t grp[1];
+} amt_igmpv3_membership_report_t;
+
+/* IGMPv3 Membership Query Format (RFC3376) */
+typedef struct _amt_igmpv3_membership_query {
+ uint8_t type;
+ uint8_t max_resp_code; /* in 100ms, Max Resp Time = (mant | 0x10) << (exp + 3) */
+ uint32_t checksum;
+ uint32_t ssmIP;
+ uint8_t s_qrv;
+ uint8_t qqic; /* in second, query Time = (mant | 0x10) << (exp + 3) */
+ uint16_t nSrc;
+ uint32_t srcIP[1];
+} amt_igmpv3_membership_query_t;
+
+/* ATM Membership Update Format (RFC7450) */
+typedef struct _amt_membership_update_msg {
+ amt_ip_alert_t ipHead;
+ amt_igmpv3_membership_report_t memReport;
+} amt_membership_update_msg_t;
+
+/* AMT Functions */
+int amt_sockets_init( stream_t *p_access );
+void amt_send_relay_discovery_msg( stream_t *p_access, char *relay_ip );
+void amt_send_relay_request( stream_t *p_access, char *relay_ip );
+int amt_joinSSM_group( stream_t *p_access );
+int amt_joinASM_group( stream_t *p_access );
+int amt_leaveASM_group( stream_t *p_access );
+int amt_leaveSSM_group( stream_t *p_access );
+bool amt_rcv_relay_adv( stream_t *p_access );
+bool amt_rcv_relay_mem_query( stream_t *p_access );
+void amt_send_mem_update( stream_t *p_access, char *relay_ip, bool leave );
+bool open_amt_tunnel( stream_t *p_access );
+void *amt_mem_upd( void *data );
+
+/* Struct to hold AMT state */
+struct access_sys_t
+{
+ char *mcastGroup;
+ char *mcastSrc;
+ char *relay;
+ char *relayDisco;
+ block_t *overflow_block;
+
+ vlc_thread_t updateThread;
+ vlc_tick_t queryTime;
+
+ /* Mulicast group and source */
+ struct sockaddr_in mcastGroupAddr;
+ struct sockaddr_in mcastSrcAddr;
+
+ /* AMT relay imformation */
+ struct sockaddr_in relayDiscoAddr;
+ struct sockaddr_in relayAddr;
+ struct sockaddr_in stLocalAddr;
+ struct sockaddr_in stSvrAddr;
+
+ /* AMT Relay Membership Query data (RFC7450) */
+ struct relay_mem_query_msg_t {
+ uint32_t ulRcvedNonce;
+ uint8_t type;
+ uint8_t uchaMAC[MAC_LEN];
+ uint8_t uchaIGMP[IGMP_QUERY_LEN];
+ } relay_mem_query_msg;
+
+ /* AMT Relay Advertisement data (RFC7450) */
+ struct relay_adv_msg_t {
+ uint32_t ulRcvNonce;
+ uint32_t ipAddr;
+ uint8_t type;
+ } relay_adv_msg;
+
+ amt_ip_t relay_ip_hdr;
+ amt_igmpv3_membership_query_t relay_igmp_query;
+ ssize_t mtu;
+
+ uint32_t glob_ulNonce;
+ uint32_t ulRelayNonce;
+
+ int fd;
+ int sAMT;
+ int sQuery;
+ int timeout;
+ int amtTimeout;
+
+ bool tryAMT;
+ bool threadReady;
+};
--
2.17.2 (Apple Git-113)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.videolan.org/pipermail/vlc-devel/attachments/20190429/ddba55cf/attachment-0001.html>
More information about the vlc-devel
mailing list