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extract-rtmp-flv
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extract-rtmp-flv
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#! /usr/bin/perl -w
#########################################################################
# #
# Extract Flash video from an RTMP tcpdump #
# Copyright (C) 2008-11, John Zaitseff #
# #
#########################################################################
# Author: John Zaitseff <J.Zaitseff@zap.org.au>
# Date: 31st March, 2011
# Version: 1.8
# This script extracts Flash video (FLV file format) from an RTMP stream
# captured by tcpdump. To capture the RTMP stream and extract it to an
# FLV video:
# 1. Run as root:
# tcpdump -i eth0 -p -s 0 -w file.tcpdump -v tcp src port 1935
# 2. As an ordinary user, open the relevant video URL in your browser
# window and start playback,
# 3. When the video finishes playing, quit the tcpdump program (using ^C),
# 4. Run this script as an ordinary user:
# extract-rtmp-flv file.tcpdump file.flv
# This program is free software. You may distribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; either Version 2 of the license, or (at your
# option) any later version.
#
# This program 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
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#########################################################################
# Configuration parameters and default values
use strict; # Enforce better programming habits
use bytes; # Don't use Unicode in this program
(our $O = $0) =~ s,^.*/,,; # Script name (without path)
our $version = "1.8"; # Script version
our $ignore_missing = 1; # True to ignore missing TCP/IP packets
our $insert_zeros = 1; # Insert zero bytes when data missing
our $debug = 1; # True (non-zero) for debugging output
our $debug_ascii_in = 1; # True to assume tcpdump is in ASCII
our $debug_ascii_sloppy = 1; # True to allow sloppiness in ASCII
our $debug_tcpip = 0; # True to dump TCP/IP info
our $debug_rtmp = 1; # True to dump RTMP packets
our $debug_flv = 1; # True to dump FLV info
our $def_rtmp_chunk_size = 128; # Default RTMP chunk size
our $max_rtmp_routing_id = 16; # Maximum allowable value of routing ID
# Programs needed for this script to function
our $tcpdump_prog = "/usr/sbin/tcpdump"; # tcpdump(8) binary
# Function prototypes
sub dump_string ($;$); # Dump string as hexadecimal and ASCII
sub bool ($); # Return boolean as a string
sub packN24 (@); # Pack integers as 24-bit strings
sub datastream_rewind (); # Reset reading from data stream
sub datastream_remember (); # Remember current position of stream
sub datastream_read ($); # Read bytes from the data stream
sub flv_data_init ($); # Set up reading from FLV stream
sub flv_data_read ($); # Read bytes from the FLV stream
#########################################################################
# Initialise global variables
our @ip_hdr_data = (); # IP header, as an array of strings
our @tcp_hdr_data = (); # TCP header, also an array of strings
our @tcp_seq_num = (); # Relative TCP sequence number of data
our @payload_data = (); # Actual raw data (array of strings)
our $src_ip_addr; # Source IP address
our $src_tcp_port; # Source TCP port number
our $dst_ip_addr; # Destination IP address
our $dst_tcp_port; # Destination TCP port number
our $initial_tcp_seq_num; # TCP sequence number of first packet
our @rtmp_hdr_data = (); # Header for RTMP packets
our @rtmp_amf_index = (); # AMF index
our @rtmp_time_stamp = (); # Time stamp of packet
our @rtmp_data_len = (); # Length of data in packet
our @rtmp_type = (); # Content type of packet
our @rtmp_routing_id = (); # Routing ID of packet
our @rtmp_payload = (); # Assembled RTMP packet data (no header)
our $rtmp_chunk_size; # Current RTMP chunk size
our $flv_name; # Name of the FLV stream
# Variables needed by the datastream functions
our $datastream_eof = 0; # Non-zero if EOF() reached
our $datastream_bytenum = 0; # Current byte count
our $datastream_pktnum = 0; # Current IP packet number
our $datastream_idx = 0; # Index within data of packet
our $saved_eof; # Saved value of EOF() flag
our $saved_bytenum; # Saved value of current byte count
our $saved_pktnum; # Saved value of current packet number
our $saved_idx; # Saved value of index in packet
# Variables needed by the flv_data functions
our $flv_data_eof = 0; # Non-zero if EOF() reached
our $flv_data_bytenum = 0; # Current byte count (in RTMP stream)
our $flv_data_pktnum = 0; # Current RTMP packet number
our $flv_data_idx = 0; # Index within data of RTMP packet
#########################################################################
# Main program
if ($#ARGV != 1) {
die "$O: Need exactly two arguments\n";
}
our $infile = $ARGV[0];
our $outfile = $ARGV[1];
# Read the tcpdump into memory, parsing it appropriately
# This script assumes the tcpdump file has been created by running
# tcpdump as shown above. In particular, it assumes that only server
# responses on TCP port 1935 have been recorded.
if ($debug) {
print "Parsing tcpdump output for $infile\n\n";
}
if ($debug_ascii_in) {
open(INFILE, "$infile")
or die "$O: Could not read $infile: $!\n";
} else {
open(INFILE, "$tcpdump_prog -r $infile -s 0 -vvv -X 2>/dev/null |")
or die "$O: Could not run tcpdump: $!\n";
}
my $pktnum = 0;
while (<INFILE>) {
my $lnum = $.;
chomp;
# Read the header line
# for tcpdump 3.x:
# if (! /^\d\d:\d\d:\d\d\.\d{6} IP \(tos 0x[0-9a-f]+, ttl \d+, id \d+, offset \d+, flags \[\w+\], proto:? TCP \(6\), length:? (\d+)\) \S+ > \S+: \S+, cksum 0x[0-9a-f]+ \(correct\), \d+:\d+\(\d+\) ack \d+ win \d+ <[^>]+>$/) {
# die "$O: Unexpected tcpdump header line, line $.:\n$_\n";
# }
# for tcpdump 4.x:
if (! /^\d\d:\d\d:\d\d\.\d{6} IP \(tos 0x[0-9a-f]+, ttl \d+, id \d+, offset \d+, flags \[\w+\], proto TCP \(6\), length (\d+)\)$/) {
die "$O: Unexpected tcpdump header line, line $.:\n$_\n";
}
my $pkt_len = $1;
my $raw_data = "";
# Read the second header line
# for tcpdump 3.x:
# ;
# for tcpdump 4.x (next 5 lines):
$_ = <INFILE>;
chomp;
if (! /^\s+\S+ > \S+: Flags \[\S+\], cksum 0x[0-9a-f]+ \((?:in)?correct(?: -> 0x[0-9a-f]+)?\), seq [0-9:]+, ack \d+, win \d+,(?: options \[[^]]+\],)? length \d+$/) {
die "$O: Unexpected tcpdump second header line, line $.:\n$_\n";
}
# Read the packet data
for (my $nlines = 0; $nlines < $pkt_len / 16; $nlines++) {
if (eof(INFILE)) {
die "$O: Unexpected tcpdump end of file, line $.\n";
}
my $line = <INFILE>;
chomp $line;
if ($line !~ /^\t0x[0-9a-f]{4}: [ 0-9a-f]{4} [ 0-9a-f]{4} [ 0-9a-f]{4} [ 0-9a-f]{4} [ 0-9a-f]{4} [ 0-9a-f]{4} [ 0-9a-f]{4} [ 0-9a-f]{4} /i) {
die "$O: Unexpected tcpdump data format, line $.:\n$line\n";
}
my $idx = $nlines * 16;
if (! $debug_ascii_sloppy) {
if (substr($line, 0, 10) ne sprintf("\t0x%04x: ", $idx)) {
die "$O: Unexpected tcpdump data index, line $. (expecting " .
sprintf("%04x", $idx) . "):\n$line\n";
}
} else {
# Don't check the data index value as strictly
if (substr($line, 0, 10) !~ /^\t0x[0-9a-f]{4}: $/i) {
die "$O: Unexpected tcpdump data index, line $. (expecting " .
sprintf("%04x", $idx) . "):\n$line\n";
}
}
substr($line, 0, 10, ""); # Remove the data index
for (my $i = $idx; $i < ($idx + 16 > $pkt_len ? $pkt_len : $idx + 16); $i++) {
# Remove preceding white space
$line =~ s/^ +//;
# Convert two hex bytes into a character (ugly hack!)
my $byte = pack("C", hex(substr($line, 0, 2)));
substr($line, 0, 2, "");
$raw_data .= $byte;
}
}
# At this stage, the entire packet is in the string $raw_data
# Parse IP header
if (((my $b = unpack("C", substr($raw_data, 0, 1))) & 0xF0) != 0x40) {
die "$O: Not an IPv4 packet, line $lnum, byte 0x0000: " .
sprintf("%02x", $b) . "\n";
}
my $ip_hdr_len = (unpack("C", substr($raw_data, 0, 1)) & 0x0F) * 4;
if ($ip_hdr_len < 20) {
die "$O: Impossible IP header length, line $lnum: $ip_hdr_len\n";
}
my $ip_pkt_len = unpack("n", substr($raw_data, 2, 2));
if ($ip_pkt_len != $pkt_len) {
die "$O: Mismatched lengths, line $lnum: IP header $ip_pkt_len vs derived $pkt_len\n";
}
my $ip_flags = unpack("C", substr($raw_data, 7, 1)) & 0xE0;
my $ip_frag_offset = unpack("C", substr($raw_data, 7, 1)) & 0x1F;
my $ip_fragmented = (($ip_flags & 0x20 != 0) || ($ip_frag_offset != 0));
if ($ip_fragmented) {
die "$O: Cannot handle IP fragments at this time, line $lnum\n";
}
my $tmp_src_ip_addr = unpack("C", substr($raw_data, 12, 1)) . "." .
unpack("C", substr($raw_data, 13, 1)) . "." .
unpack("C", substr($raw_data, 14, 1)) . "." .
unpack("C", substr($raw_data, 15, 1));
if ($pktnum == 0) {
$src_ip_addr = $tmp_src_ip_addr;
} elsif ($tmp_src_ip_addr ne $src_ip_addr) {
die "$O: Source IP addresses differ, line $lnum: $tmp_src_ip_addr vs $src_ip_addr\n";
}
my $tmp_dst_ip_addr = unpack("C", substr($raw_data, 16, 1)) . "." .
unpack("C", substr($raw_data, 17, 1)) . "." .
unpack("C", substr($raw_data, 18, 1)) . "." .
unpack("C", substr($raw_data, 19, 1));
if ($pktnum == 0) {
$dst_ip_addr = $tmp_dst_ip_addr;
} elsif ($tmp_dst_ip_addr ne $dst_ip_addr) {
die "$O: Destination IP addresses differ, line $lnum: $tmp_dst_ip_addr vs $dst_ip_addr\n";
}
if ((my $b = unpack("C", substr($raw_data, 9, 1))) != 0x06) {
die "$O: Not a TCP packet, line $lnum, byte 0x0009: " .
sprintf("%02x", $b) . "\n";
}
# Parse TCP header
my $tcp_hdr_len = (unpack("C", substr($raw_data, $ip_hdr_len + 12, 1)) &
0xF0) / 4;
if ($tcp_hdr_len < 20) {
die "$O: Impossible TCP header length, line $lnum: $tcp_hdr_len\n";
}
my $tmp_src_tcp_port = unpack("n", substr($raw_data, $ip_hdr_len + 0, 2));
if ($pktnum == 0) {
$src_tcp_port = $tmp_src_tcp_port;
} elsif ($tmp_src_tcp_port != $src_tcp_port) {
die "$O: Source TCP ports differ, line $lnum: $tmp_src_tcp_port vs $src_tcp_port\n";
}
my $tmp_dst_tcp_port = unpack("n", substr($raw_data, $ip_hdr_len + 2, 2));
if ($pktnum == 0) {
$dst_tcp_port = $tmp_dst_tcp_port;
} elsif ($tmp_dst_tcp_port != $dst_tcp_port) {
die "$O: Destination TCP ports differ, line $lnum: $tmp_dst_tcp_port vs $dst_tcp_port\n";
}
my $tcp_flags = unpack("C", substr($raw_data, $ip_hdr_len + 13, 1));
my $tcp_urg_flag = (($tcp_flags & 0x20) != 0);
my $tcp_ack_flag = (($tcp_flags & 0x10) != 0);
my $tcp_psh_flag = (($tcp_flags & 0x08) != 0);
my $tcp_rst_flag = (($tcp_flags & 0x04) != 0);
my $tcp_syn_flag = (($tcp_flags & 0x02) != 0);
my $tcp_fin_flag = (($tcp_flags & 0x01) != 0);
if ($tcp_urg_flag) {
die "$O: Cannot handle TCP packet with URG flag true, line $lnum\n";
}
if (! $tcp_ack_flag) {
die "$O: Cannot handle TCP packet with ACK flag false, line $lnum\n";
}
if ($tcp_rst_flag) {
die "$O: Cannot handle TCP packet with RST flag true, line $lnum\n";
}
my $raw_tcp_seq_num = unpack("N", substr($raw_data, $ip_hdr_len + 4, 4));
my $cur_tcp_seq_num;
# Handle TCP sequence number wrap-arounds (although this code might
# not be correct for modern TCP/IP implementations!)
if ($pktnum == 0) {
$initial_tcp_seq_num = $raw_tcp_seq_num;
if ($tcp_syn_flag) {
$initial_tcp_seq_num++;
}
$cur_tcp_seq_num = 0;
} else {
$cur_tcp_seq_num = $raw_tcp_seq_num - $initial_tcp_seq_num;
if ($cur_tcp_seq_num < 0) {
# Perl complains if we add by 0x100000000 (non-portable hex)
$cur_tcp_seq_num += 0x80000000;
$cur_tcp_seq_num += 0x80000000;
}
}
# Check if packet is in sequence
if ($pktnum != 0) {
# Check previous TCP packet to calculate expected sequence number
my $expected_seq_num = $tcp_seq_num[$#tcp_seq_num] +
length($payload_data[$#payload_data]);
if ($expected_seq_num > 0xFFFFFFFF) {
die "$O: Cannot handle TCP seq num overflow, line $lnum\n";
}
if ($cur_tcp_seq_num != $expected_seq_num) {
my $seq_num_diff = $cur_tcp_seq_num - $expected_seq_num;
if ($debug && $debug_tcpip) {
print "Note: Packet $pktnum is out of order, line $lnum:\n" .
" expecting seqnum $expected_seq_num, found $cur_tcp_seq_num " .
"(diff $seq_num_diff)\n";
}
if ($seq_num_diff > 0) {
# One or more packets have been lost somewhere (and
# hopefully retransmitted at a later stage). Do nothing
# (and pray for the best)
if ($debug && $debug_tcpip) {
print " (One or more packets have been lost; hoping for the best)\n\n";
}
} else {
# This packet has been retransmitted: search backwards
# until a suitable point of insertion is found
my $found = 0;
for (my $idx = $#tcp_seq_num; $idx >= 0; $idx--) {
if (($cur_tcp_seq_num == $tcp_seq_num[$idx]) &&
(length($payload_data[$idx]) != 0)) {
# Packet is already present at $idx: replace it
if ($debug && $debug_tcpip) {
print " (Replacing existing packet $idx)\n\n";
}
if ((length($raw_data) - $ip_hdr_len - $tcp_hdr_len)
!= length($payload_data[$idx])) {
die "$O: Replacement packet has a different data len, line $lnum:" .
(length($raw_data) - $ip_hdr_len - $tcp_hdr_len) .
" vs " . length($payload_data[$idx]) . "\n";
}
$pktnum = $idx;
$found = 1;
last;
} elsif ($cur_tcp_seq_num >= $tcp_seq_num[$idx]) {
# Insert (ie, make room for) the new packet at $idx + 1
if ($debug && $debug_tcpip) {
print " (Inserting after packet $idx)\n\n";
}
$pktnum = $idx + 1;
splice(@ip_hdr_data, $pktnum, 0, undef);
splice(@tcp_hdr_data, $pktnum, 0, undef);
splice(@tcp_seq_num, $pktnum, 0, undef);
splice(@payload_data, $pktnum, 0, undef);
$found = 1;
last;
}
}
if (! $found) {
die "$O: Could not insert out-of-order packet, line $lnum: packet $pktnum\n";
}
}
}
}
# Save the data into appropriate string arrays
$ip_hdr_data[$pktnum] = substr($raw_data, 0, $ip_hdr_len);
$tcp_hdr_data[$pktnum] = substr($raw_data, $ip_hdr_len, $tcp_hdr_len);
$tcp_seq_num[$pktnum] = $cur_tcp_seq_num;
$payload_data[$pktnum] = substr($raw_data, $ip_hdr_len + $tcp_hdr_len);
if ($debug && $debug_tcpip) {
print "Packet $pktnum: (IP hdr len ", length($ip_hdr_data[$pktnum]),
", TCP hdr len ", length($tcp_hdr_data[$pktnum]),
", data len ", length($payload_data[$pktnum]), "), line $lnum\n";
print " from $src_ip_addr (port $src_tcp_port)" .
" to $dst_ip_addr (port $dst_tcp_port)\n";
printf " raw seqnum %u rel %u (diff %d), flags PSH=%s SYN=%s FIN=%s\n\n",
$raw_tcp_seq_num, $cur_tcp_seq_num,
(($pktnum == 0) ? 0 : $cur_tcp_seq_num - $tcp_seq_num[$pktnum - 1]),
bool($tcp_psh_flag), bool($tcp_syn_flag), bool($tcp_fin_flag);
dump_string $ip_hdr_data[$pktnum], " ip ";
dump_string $tcp_hdr_data[$pktnum], " tcp ";
dump_string $payload_data[$pktnum], " data ";
print "\n";
}
} continue {
$pktnum = $#ip_hdr_data + 1;
}
close(INFILE);
#########################################################################
# Check for missing TCP/IP packets in the tcpdump
if ($debug) {
print "Checking for missing packets in tcpdump\n\n";
}
my $bytes_missing = 0;
my $expected_seq_num = 0;
for ($pktnum = 0; $pktnum <= $#tcp_seq_num; $pktnum++) {
my $seq_num_diff = $tcp_seq_num[$pktnum] - $expected_seq_num;
if ($seq_num_diff < 0) {
# This should never happen (packet reordering handled above)
die "$O: Data out of order at packet $pktnum: " .
"rel seq num $tcp_seq_num[$pktnum], diff $seq_num_diff\n";
} elsif ($seq_num_diff > 0) {
$bytes_missing += $seq_num_diff;
if (! $ignore_missing) {
die "$O: Missing data at packet $pktnum: " .
"rel seq num $tcp_seq_num[$pktnum], diff $seq_num_diff\n";
} elsif (! $debug) {
warn "$O: Missing data at packet $pktnum: " .
"rel seq num $tcp_seq_num[$pktnum], diff $seq_num_diff" .
($insert_zeros ? " (zeros inserted)\n" : "\n");
} elsif ($debug) {
print "Missing data at packet $pktnum: " .
"rel seq num $tcp_seq_num[$pktnum], diff $seq_num_diff" .
(($insert_zeros) ? " (zeros inserted)\n" : "\n");
}
if ($insert_zeros) {
splice(@ip_hdr_data, $pktnum, 0, (chr(0) x 20));
splice(@tcp_hdr_data, $pktnum, 0, (chr(0) x 32));
splice(@tcp_seq_num, $pktnum, 0, ($expected_seq_num));
splice(@payload_data, $pktnum, 0, (chr(0) x $seq_num_diff));
}
}
$expected_seq_num += length($payload_data[$pktnum]);
#@@@ $expected_seq_num = $tcp_seq_num[$pktnum] + length($payload_data[$pktnum]);
}
if ($debug && ($bytes_missing > 0)) {
print "Total missing: $bytes_missing bytes\n\n";
}
#########################################################################
# Parse the data stream as a series of (possibly partial) RTMP packets
# This script is based on the (reverse-engineered) documentation
# found on the following web sites:
# http://osflash.org/documentation/rtmp
# http://wiki.gnashdev.org/RTMP
# http://rtmpy.org/wiki/RTMP
# http://www.acmewebworks.com/Downloads/openCS/TheAMF.pdf
# Partial RTMP packet structure:
# First byte, as binary:
# |00aaaaaa| - 12-byte header, aaaaaa (in binary) = AMF index
# |01aaaaaa| - 8-byte header, aaaaaa (in binary) = AMF index
# |10aaaaaa| - 4-byte header, aaaaaa (in binary) = AMF index
# |11aaaaaa| - 1-byte header, aaaaaa (in binary) = AMF index
#
# Following bytes (if 4-, 8- or 12-byte header), as hexadecimal:
# |tt|tt|tt| - Time stamp, in MSB (network) order
# |ss|ss|ss| - Length (size) of AMF packet data, MSB (network) order
# |cc| - RTMP packet content type
# |rr|rr|rr|rr| - Routing information, in LSB order (usually a
# small integer)
if ($debug) {
print "Parsing data stream as RTMP\n\n";
}
datastream_rewind();
my $b = unpack("C", datastream_read(1));
if ($b == 0x03) {
my $tmp = datastream_read(3072);
if ($debug && $debug_rtmp) {
print "Found RTMP handshake response (ignoring following 3072 bytes)\n";
dump_string $tmp, " del ";
print "\n";
}
} else {
datastream_rewind();
if ($debug) {
printf "Note: RTMP handshake response byte 0x03 not found: " .
"found byte 0x%02x,\n" .
"assuming start of proper RTMP packet stream.\n\n", $b;
} else {
warn "$O: RTMP handshake response byte 0x03 not found: " .
sprintf("found byte 0x%02x,\n", $b) .
"assuming start of proper RTMP packet stream.\n";
}
}
if ($debug && $debug_rtmp) {
print "Default RTMP chunk size: $def_rtmp_chunk_size bytes\n\n";
}
$rtmp_chunk_size = $def_rtmp_chunk_size;
$pktnum = 0;
RTMP_PROC:
while (! $datastream_eof) {
datastream_remember(); # For debugging only
# Parse next (potentially partial) RTMP packet
my $cur_first_byte = unpack("C", datastream_read(1));
last RTMP_PROC if ($datastream_eof || ! defined($cur_first_byte));
if ($insert_zeros && ($bytes_missing > 0) && ($cur_first_byte == 0x00)) {
# Handle possible missing packets
if (($pktnum > 0) &&
(length($rtmp_payload[$pktnum - 1]) != $rtmp_data_len[$pktnum - 1])) {
# Continue as if this packet was a one-byte header
$cur_first_byte = (unpack("C", substr($rtmp_hdr_data[$pktnum - 1], 0, 1))
& 0x3F) | 0xC0;
if ($debug) {
printf "Note: NUL byte while looking for RTMP header: " .
"treating as 0x%02x,\n", $cur_first_byte;
print "data byte $saved_bytenum, IP packet $saved_pktnum, offset $saved_idx\n\n";
}
} else {
# Skip all NUL bytes
my $skip_count = 0;
while ($cur_first_byte == 0x00) {
$skip_count++;
datastream_remember();
$cur_first_byte = unpack("C", datastream_read(1));
last RTMP_PROC if ($datastream_eof || ! defined($cur_first_byte));
}
if ($debug) {
print "Note: Skipped $skip_count NUL bytes looking for next RTMP header\n\n";
}
}
}
my $cur_hdr_size;
if (($cur_first_byte & 0xC0) == 0x00) {
$cur_hdr_size = 12;
} elsif (($cur_first_byte & 0xC0) == 0x40) {
$cur_hdr_size = 8;
} elsif (($cur_first_byte & 0xC0) == 0x80) {
$cur_hdr_size = 4;
} elsif (($cur_first_byte & 0xC0) == 0xC0) {
$cur_hdr_size = 1;
}
my $cur_amf_index = $cur_first_byte & 0x3F;
my $cur_hdr_data = pack("C", $cur_first_byte) . datastream_read($cur_hdr_size - 1);
# Extract pertinent information from the rest of the header. This
# code assumes that a 1-byte header will never occur by itself: a
# longer header will be always sent before such headers.
my $cur_time_stamp;
my $cur_data_len;
my $cur_type;
my $cur_routing_id;
if ($cur_hdr_size >= 4) {
$cur_time_stamp = unpack("N", chr(0) . substr($cur_hdr_data, 1, 3));
}
if ($cur_hdr_size >= 8) {
$cur_data_len = unpack("N", chr(0) . substr($cur_hdr_data, 4, 3));
$cur_type = unpack("C", substr($cur_hdr_data, 7, 1));
}
if ($cur_hdr_size == 12) {
$cur_routing_id = unpack("V", substr($cur_hdr_data, 8, 4));
if (($cur_routing_id < 0) || ($cur_routing_id > $max_rtmp_routing_id)) {
die "$O: Illegal value for RTMP routing ID: " .
sprintf("0x%08x,\n", $cur_routing_id) .
"data byte $saved_bytenum, IP packet $saved_pktnum, offset $saved_idx\n";
}
}
my $found = 0;
for (my $idx = $#rtmp_amf_index; $idx >= 0; $idx--) {
if ($cur_amf_index == $rtmp_amf_index[$idx]) {
if (length($rtmp_payload[$idx]) == $rtmp_data_len[$idx]) {
if ($cur_hdr_size > 1) {
# A new RTMP packet is present
$found = 0;
last;
} else {
# A partial header, but previous same-index RTMP
# packet is already complete
die "$O: Short-length RTMP header " .
sprintf("0x%02x", $cur_first_byte) .
" without a previous full-length header:\n" .
"data byte $saved_bytenum, IP packet $saved_pktnum, offset $saved_idx\n";
}
} else {
# Currently stored packet data (payload) is not complete
if ($cur_hdr_size < 4) {
$cur_time_stamp = $rtmp_time_stamp[$idx];
} else {
if ($cur_time_stamp != $rtmp_time_stamp[$idx]) {
# Update the RTMP time stamp
$rtmp_time_stamp[$idx] = $cur_time_stamp;
}
}
if ($cur_hdr_size < 8) {
$cur_data_len = $rtmp_data_len[$idx];
$cur_type = $rtmp_type[$idx];
} else {
if ($cur_data_len != $rtmp_data_len[$idx]) {
die "$O: Partial RTMP data length mismatch, " .
"data byte $saved_bytenum, IP packet $saved_pktnum, offset $saved_idx:\n" .
"expecting $rtmp_data_len[$idx], found $cur_data_len\n";
}
if ($cur_type != $rtmp_type[$idx]) {
die "$O: Partial RTMP packet type mismatch, " .
"data byte $saved_bytenum, IP packet $saved_pktnum, offset $saved_idx:\n" .
"expecting $rtmp_type[$idx], found $cur_type\n";
}
}
if ($cur_hdr_size < 12) {
$cur_routing_id = $rtmp_routing_id[$idx];
} else {
if ($cur_routing_id != $rtmp_routing_id[$idx]) {
die "$O: Partial RTMP routing ID mismatch, " .
"data byte $saved_bytenum, IP packet $saved_pktnum, offset $saved_idx:\n" .
"expecting $rtmp_routing_id[$idx], found $cur_routing_id\n";
}
}
$pktnum = $idx;
$found = 1;
last;
}
}
}
if (! $found) {
if ($cur_hdr_size > 1) {
# A new RTMP packet: store it appropriately
if ($cur_hdr_size < 8) {
# Assume the same as the last RTMP packet
$cur_data_len = $rtmp_data_len[$#rtmp_data_len];
$cur_type = $rtmp_type[$#rtmp_type];
}
if ($cur_hdr_size < 12) {
# Assume the same as the last RTMP packet
$cur_routing_id = $rtmp_routing_id[$#rtmp_routing_id];
}
$rtmp_hdr_data[$pktnum] = $cur_hdr_data;
$rtmp_amf_index[$pktnum] = $cur_amf_index;
$rtmp_time_stamp[$pktnum] = $cur_time_stamp;
$rtmp_data_len[$pktnum] = $cur_data_len;
$rtmp_type[$pktnum] = $cur_type;
$rtmp_routing_id[$pktnum] = $cur_routing_id;
$rtmp_payload[$pktnum] = "";
} else {
die "$O: Short-length RTMP header " . sprintf("0x%02x", $cur_first_byte) .
" without a previous full-length header:\n" .
"data byte $saved_bytenum, IP packet $saved_pktnum, offset $saved_idx\n";
}
}
# Store RTMP payload data at $pktnum
my $data_len_diff = $cur_data_len - length($rtmp_payload[$pktnum]);
my $cur_payload = datastream_read((($data_len_diff > $rtmp_chunk_size) ?
$rtmp_chunk_size : $data_len_diff));
$rtmp_payload[$pktnum] .= $cur_payload;
my $cur_completed = (length($rtmp_payload[$pktnum]) == $cur_data_len);
if ($debug && $debug_rtmp) {
print ($cur_completed ? "Complete" : "Partial");
print " RTMP packet $pktnum at byte $saved_bytenum (IP packet $saved_pktnum, offset $saved_idx)\n";
printf " (hdr len %d, AMF index %d, type 0x%02x, routing ID 0x%08x,\n" .
" full data len %d, cur data len %d, time stamp %d)\n\n",
$cur_hdr_size, $cur_amf_index, $cur_type, $cur_routing_id,
$cur_data_len, length($rtmp_payload[$pktnum]), $cur_time_stamp;
dump_string $cur_hdr_data, " rtmp ";
dump_string $cur_payload, " data ";
print "\n";
}
# Partially process the information in the complete RTMP packet
if ($cur_completed) {
$cur_payload = $rtmp_payload[$pktnum];
if ($cur_type == 0x01) {
# Chunk size
if (($cur_data_len >= 2) &&
(unpack("C", substr($cur_payload, 0, 1)) == 0x00)) {
$rtmp_chunk_size = unpack("N", (chr(0) x (5 - $cur_data_len)) . substr($cur_payload, 1));
if ($debug && $debug_rtmp) {
print "New RTMP chuck size: $rtmp_chunk_size bytes\n\n";
}
} else {
die "$O: Cannot handle unknown RTMP Chunk Size message,\n" .
"data byte $saved_bytenum, IP packet $saved_pktnum, offset $saved_idx\n";
}
} elsif ($cur_type == 0x03) {
# Bytes read
} elsif ($cur_type == 0x04) {
# Ping
} elsif ($cur_type == 0x05) {
# Server bandwidth
} elsif ($cur_type == 0x06) {
# Client bandwidth
} elsif ($cur_type == 0x08) {
# Audio data
} elsif ($cur_type == 0x09) {
# Video data
} elsif ($cur_type == 0x0F) {
# Flex stream
} elsif ($cur_type == 0x10) {
# Flex shared object
} elsif ($cur_type == 0x11) {
# Flex message
} elsif ($cur_type == 0x12) {
# Notify
} elsif ($cur_type == 0x13) {
# Shared object
} elsif ($cur_type == 0x14) {
# Invoke RPC
} elsif ($cur_type == 0x16) {
# FLV data
} else {
# Unknown (and undocumented)
if ($debug) {
printf " RTMP packet content type 0x%02x unknown\n\n", $cur_type;
} else {
warn sprintf("$O: RTMP packet content type 0x%02x unknown in packet $pktnum,\n",
$cur_type) .
"data byte $saved_bytenum, IP packet $saved_pktnum, offset $saved_idx\n";
}
}
}
} continue {
$pktnum = $#rtmp_hdr_data + 1;
}
#########################################################################
# Extract FLV stream from the RTMP data stream
# This script is based on the documentation found on the following
# web sites:
# http://www.adobe.com/devnet/flv/pdf/video_file_format_spec_v9.pdf
# http://osflash.org/flv
# FLV file structure:
# File header, 9 bytes:
# |"FLV"|01| - FLV file signature and version number (1)
# |tt| - Type of FLV file: 0x05 = audio+video
# |dd|dd|dd|dd| - Data offset (size of header), always 9 (MSB)
# Tag0Size - always zero (4 bytes, MSB)
# Tag1, variable number of bytes:
# |cc| - Tag content type:
# 0x08 = audio, 0x09 = video, 0x18 = script data
# |ss|ss|ss| - Length of FLV data following tag header (MSB)
# |tt|tt|tt| - Time stamp (MSB)
# |uu| - Upper 8 bits of time stamp (to form 32-bit number)
# |ii|ii|ii| - Stream ID, always zero
# Tag data - Data as appropriate for the content type
# Tag1Size - size of tag header + data (4 bytes, MSB)
# Tag2 - as per Tag1
# Tag2Size - as per Tag1Size
# ...
# TagN - as per Tag1
# TagNSize - as per Tag1Size
if ($debug) {
print "Extracting FLV stream from RTMP data stream\n\n";
}
# Search for start of FLV stream: RTMP packet 0x14 with "NetStream.Play.Start"
my $found = 0;
$pktnum = 0;
while ($pktnum <= $#rtmp_type) {
if ($rtmp_type[$pktnum] == 0x14) {
my $payload = $rtmp_payload[$pktnum];
if ((substr($payload, 0, 11) eq "\x02\x00\x08onStatus") &&
($payload =~ /\x00\x04code\x02\x00\x14NetStream\.Play\.Start/)) {
if ($payload =~ /\x00\x0Bdescription\x02..Started playing (.*?)\.?\x00/) {
$found = 1;
$flv_name = $1;
if ($debug) {
print "Found FLV stream $flv_name\n";
if ($debug_flv) {
print " at RTMP packet $pktnum\n";
}
}
last;
}
}
}
} continue {
$pktnum++;
}
if (! $found) {
die "$O: Could not find start of FLV stream\n";
}
# Search for start of data: RTMP packet 0x12 with "NetStream.Data.Start"
$found = 0;
while ($pktnum <= $#rtmp_type) {
if ($rtmp_type[$pktnum] == 0x12) {
my $payload = $rtmp_payload[$pktnum];
if ((substr($payload, 0, 11) eq "\x02\x00\x08onStatus") &&
($payload =~ /\x00\x04code\x02\x00\x14NetStream\.Data\.Start/)) {
$found = 1;
if ($debug && $debug_flv) {
print "Found NetStream.Data.Start at RTMP packet $pktnum\n\n";
}
last;
}
}
} continue {
$pktnum++;
}
if (! $found) {
die "$O: Could not find start of data in FLV stream\n";
}
# Open output file and write FLV file header
if ($debug) {
print "Writing FLV stream to $outfile\n";
}
open(OUTFILE, ">", $outfile)
or die "$O: Could not write to $outfile: $!\n";
binmode(OUTFILE);
# Write the FLV file header: "FLV", version 1, type: audio+video,
# header length: 9, Tag0Size: 0.
print OUTFILE "FLV" . pack("C*", 1, 5) . pack("N", 9) . pack("N", 0);
# Next RTMP packet must contain onMetaData
$pktnum++;
$found = 0;
if ($pktnum <= $#rtmp_type) {
if ($rtmp_type[$pktnum] == 0x12) {
my $payload = $rtmp_payload[$pktnum];
if (substr($payload, 0, 13) eq "\x02\x00\x0AonMetaData") {
$found = 1;
if ($debug && $debug_flv) {
print "Found onMetaData in RTMP packet $pktnum\n";
}
}
}
}
if (! $found) {
die "$O: Could not find start of data in FLV stream\n";
}
# Output the onMetaData packet, using the FLV tag header format
my $flv_tag_hdr;
my $flv_tag_len;
$flv_tag_hdr = pack("C", 0x12) . packN24($rtmp_data_len[$pktnum],
$rtmp_time_stamp[$pktnum]) . pack("C", 0) . packN24(0);
$flv_tag_len = pack("N", $rtmp_data_len[$pktnum] + length($flv_tag_hdr));
print OUTFILE $flv_tag_hdr;
print OUTFILE $rtmp_payload[$pktnum];
print OUTFILE $flv_tag_len;
if ($debug && $debug_flv) {
print "\nWriting onMetaData to FLV file\n";
dump_string $flv_tag_hdr, " tag ";
dump_string $rtmp_payload[$pktnum], " data ";
dump_string $flv_tag_len, " len ";
print "\n";
}
# Skip next one or more packets, if these are "synchronisation" video packets
$pktnum++;
while (($pktnum <= $#rtmp_type) && ($rtmp_type[$pktnum] == 0x09)
&& ($rtmp_data_len[$pktnum] == 2)
&& (substr($rtmp_payload[$pktnum], 0, 1) eq "\x52")) {
if ($debug && $debug_flv) {
print "Skipping RTMP packet $pktnum: synchronisation packet only\n\n";
}
$pktnum++;
}
if ($pktnum > $#rtmp_type) {
die "$O: RTMP data stream ended before initial audio/video packet\n";
}
# Handle main FLV data stream: individual RTMP video/audio packets for
# the initial chunks, or 0x16 pre-packaged FLV chunks that can be
# (hopefully) written straight out
$found = 0;
while ($pktnum <= $#rtmp_type) {
if (($rtmp_type[$pktnum] == 0x08) || ($rtmp_type[$pktnum] == 0x09)) {
$found = 1;
$flv_tag_hdr = pack("C", $rtmp_type[$pktnum]) .
packN24($rtmp_data_len[$pktnum], $rtmp_time_stamp[$pktnum]) .
pack("C", 0) . packN24(0);
$flv_tag_len = pack("N", $rtmp_data_len[$pktnum] + length($flv_tag_hdr));
print OUTFILE $flv_tag_hdr;
print OUTFILE $rtmp_payload[$pktnum];
print OUTFILE $flv_tag_len;
if ($debug && $debug_flv) {
printf "Writing RTMP packet $pktnum (type 0x%02x) to FLV file\n",
$rtmp_type[$pktnum];
dump_string $flv_tag_hdr, " tag ";
dump_string $rtmp_payload[$pktnum], " data ";
dump_string $flv_tag_len, " len ";
print "\n";
}
} elsif ($rtmp_type[$pktnum] == 0x16) {
$found = 1;
flv_data_init($pktnum);
# Do we need to inspect the contents of $rtmp_payload? For the
# moment, we just dump everything as-is.
print OUTFILE $rtmp_payload[$pktnum];
if ($debug && $debug_flv) {
print "Writing RTMP packet $pktnum (type 0x16) to FLV file as-is (" .
length($rtmp_payload[$pktnum]) . " bytes)\n\n";