File Coverage

blib/lib/Net/Inspect/L7/HTTP.pm

Criterion	Covered	Total	%
statement	426	603	70.6
branch	256	466	54.9
condition	76	241	31.5
subroutine	24	35	68.5
pod	14	17	82.3
total	796	1362	58.4

############################################################################
# finds HTTP requests + responses in tcp connection
# chunked HTTP responses are supported
############################################################################
use strict;
use warnings;
package Net::Inspect::L7::HTTP;
use base 'Net::Inspect::Flow';
use Net::Inspect::Debug qw(:DEFAULT $DEBUG %TRACE);
use Hash::Util 'lock_ref_keys';
use Carp 'croak';
use Scalar::Util 'weaken';
use fields (
    'replay',   # collected and replayed in guess_protocol
    'meta',     # meta data from connection
    'requests', # list of open requests, see _in0 for fields
    'error',    # connection has error like server sending data w/o request
    'upgrade',  # true if got upgrade, CONNECT, WebSockets..
    'connid',   # connection id
    'lastreqid',# id of last request
    'offset',   # offset in data stream
    'gap_upto', # up to which offset we could manage a gap, that is where we
		# only get body data (no header, chunked info..).
		# [off,off] similar to offset and off is set to -1 if umlimited
		# (i.e. body ends with end of file)
    'hdr_maxsz',# maximum header size for request(0), response(1) and
		# chunk header(2). Defaults to 64k, 16k and 2k.
);

use Exporter 'import';
our (@EXPORT_OK,%EXPORT_TAGS);
{
    %EXPORT_TAGS = (
	need_body => [qw(
	    METHODS_WITHOUT_RQBODY METHODS_WITH_RQBODY METHODS_WITHOUT_RPBODY
	    CODE_WITHOUT_RPBODY
	)]
    );
    push @EXPORT_OK,@$_ for (values %EXPORT_TAGS);
    push @EXPORT_OK,'parse_hdrfields','parse_reqhdr','parse_rsphdr';
}

use constant {
    METHODS_WITHOUT_RQBODY => [qw(GET HEAD DELETE CONNECT)],
    METHODS_WITH_RQBODY    => [qw(POST PUT)],
    METHODS_WITHOUT_RPBODY => [qw(HEAD CONNECT)],
    CODE_WITHOUT_RPBODY    => [100..199, 204, 205, 304],
};

use constant {
    RQHDR_DONE => 0b00001,
    RQBDY_DONE => 0b00010,
    RQ_ERROR   => 0b00100,
    RPHDR_DONE => 0b01000,
    RPBDY_DONE_ON_EOF => 0b10000,
};

# rfc2616, 2.2
#  token          = 1*
#  separators     = "(" | ")" | "<" | ">" | "@"
#                 | "," | ";" | ":" | "\" | <">
#                 | "/" | "[" | "]" | "?" | "="
#                 | "{" | "}" | SP | HT

my $separator = qr{[()<>@,;:\\"/\[\]?={} \t]};
my $token = qr{[^()<>@,;:\\"/\[\]?={}\x00-\x20\x7f]+};
my $token_value_cont = qr{
    ($token):                      # key:
    [\040\t]*([^\r\n]*?)[\040\t]*  # value
    ((?:\r?\n[\040\t][^\r\n]*)*)   # continuation lines
    \r?\n                          # (CR)LF
}x;

# common error: "Last Modified" instead of "Last-Modified"
# squid seems to just strip invalid headers, try the same
my $xtoken = qr{[^()<>@,;:\\"/\[\]?={}\x00-\x20\x7f][^:[:^print:]]*};

my %METHODS_WITHOUT_RQBODY = map { ($_,1) } @{METHODS_WITHOUT_RQBODY()};
my %METHODS_WITH_RQBODY    = map { ($_,1) } @{METHODS_WITH_RQBODY()};
my %METHODS_WITHOUT_RPBODY = map { ($_,1) } @{METHODS_WITHOUT_RPBODY()};
my %CODE_WITHOUT_RPBODY    = map { ($_,1) } @{CODE_WITHOUT_RPBODY()};

sub guess_protocol {
    my ($self,$guess,$dir,$data,$eof,$time,$meta) = @_;

    if ( $dir == 0 ) {
	my $rp = $self->{replay} ||= [];
	push @$rp,[$data,$eof,$time];
	my $buf = join('',map { $_->[0] } @$rp);
	if ( $buf =~m{
	    \A[\r\n]*                                   # initial junk
	    [A-Z]{2,20}[\040\t]{1,3}                    # method
	    \S+[\040\t]{1,3}                            # path/URI
	    HTTP/1\.[01][\040\t]{0,3}                   # version
	    \r?\n                                       # (CR)LF
	    (?:$xtoken:.*\r?\n(?:[\t\040].*\r?\n)* )*   # field:..+cont
	    \r?\n                                       # empty line
	}xi) {
	    # looks like HTTP request
	    my $obj =  $self->new_connection($meta);
	    # replay as one piece
	    my $n = $obj->in(0,$buf,$rp->[-1][1],$rp->[-1][2]);
	    undef $self->{replay};
	    $n += -length($buf) + length($data);
	    $n<=0 and die "object $obj did not consume alle replayed bytes";
	    debug("consumed $n of ".length($data)." bytes");
	    return ($obj,$n);

	} elsif ( $buf =~m{[^\n]\r?\n\r?\n}
	    or length($buf)>2**16 ) {
	    # does not look like a HTTP header for me
	    debug("does not look like HTTP header: $buf");
	    $guess->detach($self);
	} else {
	    debug("need more data to decide if HTTP");
	    return;
	}
    } else {
	# data from server but no request header from
	# client yet - cannot be HTTP
	debug("got data from server before getting request from client -> no HTTP");
	$guess->detach($self);
    }
    return;
}


{
    my $connid = 0;
    sub syn { 1 }; # in case it is attached to Net::Inspect::Tcp
    sub new_connection {
	my ($self,$meta,%args) = @_;
	my $obj = $self->new;
	$obj->{meta} = $meta;
	$obj->{requests} = [];
	$obj->{connid} = ++$connid;
	$obj->{lastreqid} = 0;
	$obj->{offset} = [0,0];
	$obj->{gap_upto} = [0,0];
	$obj->{hdr_maxsz} = delete $args{header_maxsize};
	$obj->{hdr_maxsz}[0] ||= 2**16;
	$obj->{hdr_maxsz}[1] ||= 2**14;
	$obj->{hdr_maxsz}[2] ||= 2**11;

	return $obj;
    }
}

sub in {
    my ($self,$dir,$data,$eof,$time) = @_;
    $DEBUG && $self->xdebug("got %s bytes from %d, eof=%d",
	ref($data) ? join(":",@$data): length($data),
	$dir,$eof//0
    );
    my $bytes = $dir == 0
	? _in0($self,$data,$eof,$time)
	: _in1($self,$data,$eof,$time);
    #$self->dump_state if $DEBUG;
    return $bytes;
}

sub offset {
    my $self = shift;
    return @{ $self->{offset} }[wantarray ? @_:$_[0]];
}

sub gap_diff {
    my $self = shift;
    my @rv;
    for(@_) {
	my $off = $self->{gap_upto}[$_];
	push @rv,
	    $off == -1 ? -1 :
	    ($off-=$self->{offset}[$_]) > 0 ? $off :
	    0;
    }
    return wantarray ? @rv : $rv[0];
}

sub set_gap_diff {
    my ($self,$dir,$diff) = @_;
    $self->{gap_upto}[$dir] = defined($diff)
	? $self->{offset}[$dir] + $diff   # add to offset
	: 0;                              # reset gap_upto
}

sub gap_offset {
    my $self = shift;
    my @rv;
    for(@_) {
	my $off = $self->{gap_upto}[$_];
	push @rv,
	    $off == -1 ? -1 :
	    $off > $self->{offset}[$_] ? $off :
	    0
    }
    return wantarray ? @rv : $rv[0];
}

# give requests a chance to cleanup before destroying connection
sub DESTROY {
    my $self = shift;
    @{$self->{requests}} = ();
}


# process request data
sub _in0 {
    my ($self,$data,$eof,$time) = @_;
    my $bytes = 0; # processed bytes
    my $rqs = $self->{requests};

    if ( ref($data)) {
	# process gap in request data
	croak "unknown type $data->[0]" if $data->[0] ne 'gap';
	my $len = $data->[1];

	croak 'existing error in connection' if $self->{error};

	my $rqs = $self->{requests};
	croak 'no open request' if ! @$rqs or
	    $rqs->[0]{state} & RQBDY_DONE && ! $self->{upgrade};
	croak 'existing error in request' if $rqs->[0]{state} & RQ_ERROR;
	croak "gap too large" if $self->{gap_upto}[0]>=0
	    && $self->{gap_upto}[0] < $self->{offset}[0] + $len;

	if (defined $rqs->[0]{rqclen}) {
	    $rqs->[0]{rqclen} -= $len;
	    if ( ! $rqs->[0]{rqclen} && ! $rqs->[0]{rqchunked} ) {
		$rqs->[0]{state} |= RQBDY_DONE;
	    }
	}

	$self->{offset}[0] += $len;
	my $obj = $rqs->[0]{obj};
	if ($self->{upgrade}) {
	    $self->{upgrade}(0,[ gap => $len ],$eof,$time);
	} elsif ($obj) {
	    $obj->in_request_body(
		[ gap => $len ],
		$eof || ($rqs->[0]{state} & RQBDY_DONE ? 1:0),
		$time
	    );
	}
	return $len;
    }

    READ_DATA:

    if ($self->{error}) {
	$DEBUG && $self->xdebug("no more data because of server side error");
	return $bytes;
    }

    if ($self->{upgrade}) {
	$self->{offset}[0] += length($data);
	$self->{upgrade}(0,$data,$eof,$time);
	return $bytes + length($data);
    }

    if (@$rqs and $rqs->[0]{state} & RQ_ERROR ) {
	# error reading request
	$DEBUG && $self->xdebug("no more data because of client side error");
	return $bytes;
    }

    if ( ( ! @$rqs or $rqs->[0]{state} & RQBDY_DONE )
	and $data =~m{\A[\r\n]+}g ) {
	# first request or previous request body done
	# new request might follow but maybe we only have trailing lines after
	# the last request: eat empty lines
	my $n = pos($data);
	$bytes += $n;
	$self->{offset}[0] += $n;
	substr($data,0,$n,'');
	%TRACE && $self->xtrace("eat empty lines before request header");
    }

    if ( $data eq '' ) {
	$DEBUG && $self->xdebug("no data, eof=$eof, bytes=$bytes");
	return $bytes if ! $eof; # need more data

	# handle EOF
	# check if we got request body for last request
	if ( @$rqs and not $rqs->[0]{state} & RQBDY_DONE ) {
	    # request body not done yet
	    %TRACE && ($rqs->[0]{obj}||$self)->xtrace("request body not done but eof");
	    ($rqs->[0]{obj}||$self)->fatal('eof but request body not done',0,$time);
	    $rqs->[0]{state} |= RQ_ERROR;
	    return $bytes;
	}

	return $bytes; # request body done
    }

    # create new request if no open request or last open request has the
    # request body already done (pipelining)
    if ( ! @$rqs or $rqs->[0]{state} & RQBDY_DONE ) {
	my $reqid = ++$self->{lastreqid};
	my $obj = $self->new_request({
	    %{$self->{meta}},
	    time => $time,
	    reqid => $reqid,
	});
	my $rq = {
	    obj      => $obj,
	    # bitmask what is done: rpbody|rphdr|rqerror|rqbody|rqhdr
	    state    => 0,
	    rqclen   => undef,   # open content-length request
	    rpclen   => undef,   # open content-length response
	    # chunked mode for request|response:
	    #   false - no chunking
	    #   1,r[qp]clen == 0 - next will be chunk size
	    #   1,r[qp]clen > 0  - inside chunk data, need *clen
	    #   2 - next will be chunk
	    #   3 - after last chunk, next will be chunk trailer
	    rqchunked => undef,  # chunked mode for request
	    rpchunked => undef,  # chunked mode for response
	    request   => undef,  # result from parse_reqhdr
	};

	if ($DEBUG) {
	    $rq->{reqid} = $reqid;
	    weaken($rq->{conn} = $self);
	    bless $rq, 'Net::Inspect::L7::HTTP::_DebugRequest';
	    $rq->xdebug("create new request");
	}
	lock_ref_keys($rq);
	unshift @$rqs, $rq;
    }

    my $rq = $rqs->[0];
    my $obj = $rq->{obj};

    # read request header if not done
    if ( not $rq->{state} & RQHDR_DONE ) {
	# no request header yet, check if data contains it

	# leading newlines at beginning of request are legally ignored junk
	if ( $data =~s{\A([\r\n]+)}{} ) {
	    ($obj||$self)->in_junk(0,$1,0,$time);
	}

	$DEBUG && $rq->xdebug("need to read request header");
	if ($data =~s{\A(\A.*?\n\r?\n)}{}s) {
	    $DEBUG && $rq->xdebug("got request header");
	    my $hdr = $1;
	    my $n = length($hdr);
	    $self->{offset}[0] += $n;
	    $bytes += $n;
	    $rq->{state} |= RQHDR_DONE; # rqhdr done

	    my (%hdr,@warn);
	    my $err = parse_reqhdr($hdr,\%hdr,\@warn);
	    if ($err and my $sub = $obj->can('fix_reqhdr')) {
		$hdr = $sub->($obj,$hdr);
		$err = parse_rsphdr($hdr,\%hdr,\@warn);
	    }
	    if (@warn && %TRACE) {
		$self->xtrace($_) for @warn;
	    }

	    if ($err) {
		($obj||$self)->fatal($err,0,$time);
		$rq->{state} |= RQ_ERROR;
		return $bytes;
	    }

	    my $body_done;
	    if ($hdr{chunked}) {
		$rq->{rqchunked} = 1;
	    } elsif ($hdr{content_length}) {
		$rq->{rqclen} = $hdr{content_length};
		$self->{gap_upto}[0]= $self->{offset}[0] + $hdr{content_length};
	    } else {
		$body_done = 1;
	    }

	    $rq->{request} = \%hdr;

	    %TRACE && $hdr{junk} && ($obj||$self)->xtrace(
		"invalid request header data: $hdr{junk}");

	    $obj && $obj->in_request_header($hdr,$time,\%hdr);

	    if ($body_done) {
		$DEBUG && $rq->xdebug("request done (no body)");
		$rq->{state} |= RQBDY_DONE;
		if ($hdr{method} eq 'CONNECT' || $hdr{upgrade}) {
		    # Don't propagate an empty request body:
		    # with CONNECT there will be no body and with Upgrade we
		    # will have no body if the upgrade succeeded. If it failed
		    # we submit the body later.
		} else {
		    $obj && $obj->in_request_body('',1,$time);
		}
	    }

	} elsif ($data =~m{[\x00-\x08\x0b\x0c\x0e-\x1f\x7f]}) {
	    # junk data, maybe attempt to use SOCKS instead of proxy request
	    ($obj||$self)->fatal( sprintf(
		"junk data instead of request header '%s...'",
		substr($data,0,10)),0,$time);
	    $rq->{state} |= RQ_ERROR;
	    return $bytes;
	} elsif ( length($data) > $self->{hdr_maxsz}[0] ) {
	    ($obj||$self)->fatal('request header too big',0,$time);
	    $rq->{state} |= RQ_ERROR;
	    return $bytes;
	} elsif ( $eof ) {
	    ($obj||$self)->fatal('eof in request header',0,$time);
	    $rq->{state} |= RQ_ERROR;
	    return $bytes;
	} else {
	    # will be called on new data from upper flow
	    $DEBUG && $rq->xdebug("need more bytes for request header");
	    return $bytes;
	}
    }

    # read request body if not done
    if ( $data ne '' and not $rq->{state} & RQBDY_DONE ) {
	# request body
	if ( my $want = $rq->{rqclen} ) {
	    my $l = length($data);
	    if ( $l>=$want) {
		# got all request body
		$DEBUG && $rq->xdebug("need $want bytes, got all");
		my $body = substr($data,0,$rq->{rqclen},'');
		$self->{offset}[0] += $rq->{rqclen};
		$bytes += $rq->{rqclen};
		$rq->{rqclen} = 0;
		if ( ! $rq->{rqchunked} ) {
		    $DEBUG && $rq->xdebug("request done (full clen)");
		    $rq->{state} |= RQBDY_DONE; # req body done
		    $obj && $obj->in_request_body($body,1,$time)
		} else {
		    $obj && $obj->in_request_body($body,$eof,$time);
		    $rq->{rqchunked} = 2; # get CRLF after chunk
		}
	    } else {
		# only part
		$DEBUG && $rq->xdebug("need $want bytes, got only $l");
		my $body = substr($data,0,$l,'');
		$self->{offset}[0] += $l;
		$bytes += $l;
		$rq->{rqclen} -= $l;
		$obj && $obj->in_request_body($body,0,$time);
	    }

	# Chunking: rfc2616, 3.6.1
	} else {
	    # [2] must get CRLF after chunk
	    if ( $rq->{rqchunked} == 2 ) {
		$DEBUG && $rq->xdebug("want CRLF after chunk");
		if ( $data =~m{\A\r?\n}g ) {
		    my $n = pos($data);
		    $self->{offset}[0] += $n;
		    $bytes += $n;
		    substr($data,0,$n,'');
		    $rq->{rqchunked} = 1; # get next chunk header
		    $DEBUG && $rq->xdebug("got CRLF after chunk");
		} elsif ( length($data)>=2 ) {
		    ($obj||$self)->fatal("no CRLF after chunk",0,$time);
		    $self->{error} = 1;
		    return $bytes;
		} else {
		    # need more
		    return $bytes;
		}
	    }

	    # [1] must read chunk header
	    if ( $rq->{rqchunked} == 1 ) {
		$DEBUG && $rq->xdebug("want chunk header");
		if ( $data =~m{\A([\da-fA-F]+)[ \t]*(?:;.*)?\r?\n}g ) {
		    $rq->{rqclen} = hex($1);
		    my $chdr = substr($data,0,pos($data),'');
		    $self->{offset}[0] += length($chdr);
		    $bytes += length($chdr);

		    $self->{gap_upto}[0] = $self->{offset}[0] + $rq->{rqclen}
			if $rq->{rqclen};

		    $obj->in_chunk_header(0,$chdr,$time) if $obj;
		    $DEBUG && $rq->xdebug(
			"got chunk header - want $rq->{rqclen} bytes");
		    if ( ! $rq->{rqclen} ) {
			# last chunk
			$rq->{rqchunked} = 3;
			$obj && $obj->in_request_body('',1,$time);
		    }
		} elsif ( $data =~m{\n} or length($data)>8192 ) {
		    ($obj||$self)->fatal("invalid chunk header",0,$time);
		    $self->{error} = 1;
		    return $bytes;
		} else {
		    # need more data
		    return $bytes;
		}
	    }

	    # [3] must read chunk trailer
	    if ( $rq->{rqchunked} == 3 ) {
		$DEBUG && $rq->xdebug("want chunk trailer");
		if ( $data =~m{\A
		    (?:\w[\w\-]*:.*\r?\n(?:[\t\040].*\r?\n)* )*  # field:..+cont
		    \r?\n
		}xg) {
		    $DEBUG && $rq->xdebug("request done (chunk trailer)");
		    my $trailer = substr($data,0,pos($data),'');
		    $self->{offset}[0] += length($trailer);
		    $bytes += length($trailer);
		    $obj->in_chunk_trailer(0,$trailer,$time) if $obj;
		    $rq->{state} |= RQBDY_DONE; # request done
		} elsif ( $data =~m{\n\r?\n}
		    or length($data) > $self->{hdr_maxsz}[2] ) {
		    ($obj||$self)->fatal("invalid chunk trailer",0,$time);
		    $self->{error} = 1;
		    return $bytes;
		} elsif ( $eof ) {
		    # not fatal, because we got all data
		    %TRACE && ($obj||$self)->xtrace(
			"eof before end of chunk trailer");
		    $self->{error} = 1;
		    return $bytes;
		} else {
		    # need more
		    $DEBUG && $rq->xdebug("need more bytes for chunk trailer");
		    return $bytes
		}
	    }
	}
    }

    goto READ_DATA;
}



# process response data
sub _in1 {
    my ($self,$data,$eof,$time) = @_;

    my $rqs = $self->{requests};
    my $bytes = 0; # processed bytes

    if ( ref($data)) {
	# process gap in response data
	croak "unknown type $data->[0]" if $data->[0] ne 'gap';
	my $len = $data->[1];

	croak 'existing error in connection' if $self->{error};

	my $rqs = $self->{requests};
	croak 'no open response' if ! @$rqs;
	my $rq = $rqs->[-1];
	croak 'existing error in request' if $rq->{state} & RQ_ERROR;
	croak "gap too large" if $self->{gap_upto}[1]>=0
	    && $self->{gap_upto}[1] < $self->{offset}[1] + $len;

	$rq->{rpclen} -= $len if defined $rq->{rpclen};
	$self->{offset}[1] += $len;

	my $obj = $rq->{obj};
	if ($self->{upgrade}) {
	    $self->{upgrade}(1,[ gap => $len ],$eof,$time);
	} elsif ($rq->{rpclen}
	    or !defined $rq->{rpclen}
	    or $rq->{rpchunked}) {
	    $obj && $obj->in_response_body([ gap => $len ],$eof,$time);
	} else {
	    # done with request
	    $DEBUG && $rq->xdebug("response done (last gap)");
	    pop(@$rqs);
	    $obj && $obj->in_response_body([ gap => $len ],1,$time);
	}
	return $len;
    }


    READ_DATA:

    return $bytes if $self->{error};
    return $bytes if $data eq '' && !$eof;

    if ($self->{upgrade}) {
	$self->{offset}[1] += length($data);
	$self->{upgrade}(1,$data,$eof,$time);
	return $bytes + length($data);
    }

    if ( $data eq '' ) {
	$DEBUG && $self->xdebug("no more data, eof=$eof bytes=$bytes");

	# handle EOF
	# check if we got response body for last request
	if ( @$rqs && $rqs->[-1]{state} & RPBDY_DONE_ON_EOF ) {
	    # response body done on eof
	    my $rq = pop(@$rqs);
	    $DEBUG && $rq->xdebug("response done (eof)");
	    $rq->{obj}->in_response_body('',1,$time) if $rq->{obj};

	} elsif ( @$rqs ) {
	    # response body not done yet
	    my $rq = pop(@$rqs);
	    $DEBUG && $rq->xdebug("response done (unexpected eof)");
	    if (($rq->{state} & RPHDR_DONE) == 0) {
		if ($data eq '' and $self->{lastreqid}>1) {
		    # We had already a request and now the server closes while
		    # the client is still sending a new request. This happens
		    # with keep-alive connections and the client needs to handle
		    # this case with retrying the request. Signal this issue by
		    # calling in_request_header with empty header.
		    ($rq->{obj}||$self)->in_request_header('',$time);
		} elsif ($data eq '') {
		    ($rq->{obj}||$self)->fatal(
			'eof before receiving first response', 1,$time);
		} else {
		    %TRACE && ($rq->{obj}||$self)->xtrace(
			"eof within response header: '$data'");
		    ($rq->{obj}||$self)->fatal(
			'eof within response header', 1,$time);
		}
	    } else {
		# eof inside a response or close for first request already.
		%TRACE && ($rq->{obj}||$self)->xtrace("eof within response body");
		($rq->{obj}||$self)->fatal('eof within response body', 1,$time);
	    }
	}

	return $bytes; # done
    }

    if ( ! @$rqs ) {
	if ( $data =~s{\A([\r\n]+)}{} ) {
	    # skip newlines after request because newlines at beginning of
	    # new request are allowed, stupid
	    $bytes += length($1);
	    goto READ_DATA;
	}

	$self->fatal('data from server w/o request',1,$time);
	$self->{error} = 1;
	return $bytes;
    }

    my $rq = $rqs->[-1];
    my $obj = $rq->{obj};

    # read response header if not done
    if ( not $rq->{state} & RPHDR_DONE ) {
	$DEBUG && $rq->xdebug("response header not read yet");

	# leading newlines at beginning of response are legally ignored junk
	if ( $data =~s{\A([\r\n]+)}{} ) {
	    ($obj||$self)->in_junk(1,$1,0,$time);
	}

	# no response header yet, check if data contains it
	if ( $data =~s{\A(.*?\n\r?\n)}{}s ) {
	    my $hdr = $1;
	    my $n = length($hdr);
	    $bytes += $n;
	    $self->{offset}[1] += $n;

	    my %hdr;
	    my $err = parse_rsphdr($hdr,$rq->{request},\%hdr);
	    if ($err and my $sub = $obj->can('fix_rsphdr')) {
		$hdr = $sub->($obj,$hdr);
		$err = parse_rsphdr($hdr,$rq->{request},\%hdr);
	    }

	    goto error if $err;
	    $DEBUG && $rq->xdebug("got response header");

	    %TRACE && $hdr{junk} && ($obj||$self)->xtrace(
		"invalid request header data: $hdr{junk}");

	    if ($hdr{preliminary}) {
		# Preliminary response. Wait for read real response.
		$obj && $obj->in_response_header($hdr,$time,\%hdr);
		goto READ_DATA;
	    }

	    $rq->{state} |= RPHDR_DONE; # response header done

	    if ($hdr{upgrade}) {
		# Reset length to undef since we need to read until eof.
		$rq->{rpclen} = undef;

		# If no object is given we just use a dummy function which
		# returns the size of the data.
		# If object has its own upgrade_XXXX method for the protocol we
		# use this. Support for CONNECT has been traditionally built in
		# but can be redefined with upgrade_CONNECT.

		if (!$obj) {
		    $self->{upgrade} = sub {};
		    @{$self->{gap_upto}} = (-1,-1);

		} elsif (my $sub = $obj->can('upgrade_'.$hdr{upgrade})) {
		    # $sub might throw an error if it is unwilling to upgrade
		    # the connection based on request and response.
		    unless ($self->{upgrade} = eval {
			$sub->($obj,$self,$rq->{request},\%hdr)
		    }) {
			$err = "invalid connection upgrade '$hdr{upgrade}': $@";
			goto error;
		    }

		} elsif ($sub = $obj->can('upgrade_ANY')) {
		    # $sub might throw an error if it is unwilling to upgrade
		    # the connection based on request and response.
		    unless ($self->{upgrade} = eval {
			$sub->($obj,$self,$rq->{request},\%hdr,$hdr{upgrade})
		    }) {
			$err = "invalid connection upgrade '$hdr{upgrade}': $@";
			goto error;
		    }

		} elsif ($hdr{upgrade} eq 'CONNECT') {
		    # Traditionally just calls in_data. If this is not available
		    # call dummy function.
		    $self->{upgrade} = $obj->can('in_data') && do {
			weaken(my $wobj = $obj);
			sub { $wobj->in_data(@_) }
		    } || sub {};
		    @{$self->{gap_upto}} = (-1,-1);

		} else {
		    $err = "unsupported connection upgrade '$hdr{upgrade}'";
		    goto error;
		}

		goto done;
	    } elsif ($rq->{request}{upgrade}) {
		# The client requested an upgrade which the server did not ack.
		# Thus propagate the empty request body now.
		$obj && $obj->in_request_body('',1,$time);
	    }

	    my $body_done;
	    if ($hdr{chunked}) {
		$rq->{rpchunked} = 1;
	    } elsif (defined $hdr{content_length}) {
		if (($rq->{rpclen} = $hdr{content_length})) {
		    # content_length > 0, can do gaps
		    $self->{gap_upto}[1]= $self->{offset}[1]
			+ $hdr{content_length};
		} else {
		    $body_done = 1;
		}
	    } else {
		# no length given but method supports body -> end with eof
		$rq->{state} |= RPBDY_DONE_ON_EOF; # body done when eof
		$self->{gap_upto}[1] = -1;
	    }

	    done:
	    $obj && $obj->in_response_header($hdr,$time,\%hdr);
	    if ($body_done) {
		$DEBUG && $rq->xdebug("response done (no body)");
		pop(@$rqs);
		$obj && $obj->in_response_body('',1,$time);
	    }
	    goto READ_DATA;

		error:
		$self->{error} = 1;
		($obj||$self)->fatal($err,1,$time);
		return $bytes;

	} elsif ($data =~m{[\x00-\x08\x0b\x0c\x0e-\x1f\x7f]}) {
	    ($obj||$self)->fatal( sprintf(
		"junk data instead of response header '%s...'",
		substr($data,0,10)) ,1,$time);
	    $self->{error} = 1;
	    return $bytes;
	} elsif ( $data =~m{[^\n]\r?\n\r?\n}g ) {
	    ($obj||$self)->fatal( sprintf("invalid response header syntax '%s'",
		substr($data,0,pos($data))),1,$time);
	    $self->{error} = 1;
	    return $bytes;
	} elsif ( length($data) > $self->{hdr_maxsz}[1] ) {
	    ($obj||$self)->fatal('response header too big',1,$time);
	    $self->{error} = 1;
	    return $bytes;
	} elsif ( $eof ) {
	    ($obj||$self)->fatal('eof in response header',1,$time);
	    $self->{error} = 1;
	    return $bytes;
	} else {
	    # will be called on new data from upper flow
	    $DEBUG && $rq->xdebug("need more data for response header");
	    return $bytes;
	}
    }

    # read response body
    if ( $data ne '' ) {
	# response body
	$DEBUG && $rq->xdebug("response body data");

	# have content-length or within chunk
	if ( my $want = $rq->{rpclen} ) {
	    # called for content-length or to read content from chunk
	    # with known length
	    my $l = length($data);
	    if ( $l >= $want ) {
		$DEBUG && $rq->xdebug("need $want bytes, got all($l)");
		# got all response body
		my $body = substr($data,0,$want,'');
		$self->{offset}[1] += $want;
		$bytes += $want;
		$rq->{rpclen} = 0;
		if ( ! $rq->{rpchunked} ) {
		    # response done
		    pop(@$rqs);
		    $DEBUG && $rq->xdebug("response done (full clen received)");
		    $obj && $obj->in_response_body($body,1,$time);
		} else {
		    $obj->in_response_body($body,0,$time) if $obj;
		    $rq->{rpchunked} = 2; # get CRLF after chunk
		}
	    } else {
		# only part
		$DEBUG && $rq->xdebug("need $want bytes, got only $l");
		my $body = substr($data,0,$l,'');
		$self->{offset}[1] += $l;
		$bytes += $l;
		$rq->{rpclen} -= $l;
		$obj->in_response_body($body,0,$time) if $obj;
	    }

	# no content-length, no chunk: must read until eof
	} elsif ( $rq->{state} & RPBDY_DONE_ON_EOF ) {
	    $DEBUG && $rq->xdebug("read until eof");
	    $self->{offset}[1] += length($data);
	    $bytes += length($data);
	    if ($eof) {
		# response done
		pop(@$rqs);
		$DEBUG && $rq->xdebug("response done (eof)");
	    }
	    $obj->in_response_body($data,$eof,$time) if $obj;
	    $data = '';
	    return $bytes;

	# Chunking: rfc2616, 3.6.1
	} elsif ( ! $rq->{rpchunked} ) {
	    # should not happen
	    die "no content-length and no chunked - why we are here?";
	} else {
	    # [2] must get CRLF after chunk
	    if ( $rq->{rpchunked} == 2 ) {
		$DEBUG && $rq->xdebug("want CRLF after chunk");
		if ( $data =~m{\A\r?\n}g ) {
		    my $n = pos($data);
		    $self->{offset}[1] += $n;
		    $bytes += $n;
		    substr($data,0,$n,'');
		    $rq->{rpchunked} = 1; # get next chunk header
		    $DEBUG && $rq->xdebug("got CRLF after chunk");
		} elsif ( length($data)>=2 ) {
		    ($obj||$self)->fatal("no CRLF after chunk",1,$time);
		    $self->{error} = 1;
		    return $bytes;
		} else {
		    # need more
		    return $bytes;
		}
	    }

	    # [1] must read chunk header
	    if ( $rq->{rpchunked} == 1 ) {
		$DEBUG && $rq->xdebug("want chunk header");
		if ( $data =~m{\A([\da-fA-F]+)[ \t]*(?:;.*)?\r?\n}g ) {
		    $rq->{rpclen} = hex($1);
		    my $chdr = substr($data,0,pos($data),'');
		    $self->{offset}[1] += length($chdr);
		    $bytes += length($chdr);
		    $self->{gap_upto}[1] = $self->{offset}[1] + $rq->{rpclen}
			if $rq->{rpclen};

		    $obj->in_chunk_header(1,$chdr,$time) if $obj;
		    $DEBUG && $rq->xdebug(
			"got chunk header - want $rq->{rpclen} bytes");
		    if ( ! $rq->{rpclen} ) {
			# last chunk
			$rq->{rpchunked} = 3;
			$obj && $obj->in_response_body('',1,$time);
		    }
		} elsif ( $data =~m{\n} or length($data)>8192 ) {
		    ($obj||$self)->fatal("invalid chunk header",1,$time);
		    $self->{error} = 1;
		    return $bytes;
		} else {
		    # need more data
		    return $bytes;
		}
	    }

	    # [3] must read chunk trailer
	    if ( $rq->{rpchunked} == 3 ) {
		$DEBUG && $rq->xdebug("want chunk trailer");
		if ( $data =~m{\A
		    (?:\w[\w\-]*:.*\r?\n(?:[\t\040].*\r?\n)* )*  # field:..+cont
		    \r?\n
		}xg) {
		    $DEBUG && $rq->xdebug("response done (chunk trailer)");
		    my $trailer = substr($data,0,pos($data),'');
		    $self->{offset}[1] += length($trailer);
		    $bytes += length($trailer);
		    $obj->in_chunk_trailer(1,$trailer,$time) if $obj;
		    pop(@$rqs); # done
		} elsif ( $data =~m{\n\r?\n} or
		    length($data)>$self->{hdr_maxsz}[2] ) {
		    ($obj||$self)->fatal("invalid chunk trailer",1,$time);
		    $self->{error} = 1;
		    return $bytes;
		} else {
		    # need more
		    $DEBUG && $rq->xdebug("need more bytes for chunk trailer");
		    return $bytes
		}
	    }
	}
    }

    goto READ_DATA;
}

# parse and normalize header
sub parse_hdrfields {
    my ($hdr,$fields) = @_;
    return '' if ! defined $hdr;
    my $bad = '';
    parse:
    while ( $hdr =~m{\G$token_value_cont}gc ) {
	if ($3 eq '') {
	    # no continuation line
	    push @{$fields->{ lc($1) }},$2;
	} else {
	    # with continuation line
	    my ($k,$v) = ($1,$2.$3);
	    # value-part -> ' ' + value-part
	    $v =~s{[\r\n]+[ \t](.*?)[ \t]*}{ $1}g;
	    push @{$fields->{ lc($k) }},$v;
	}
    }
    if (pos($hdr)//0 != length($hdr)) {
	# bad line inside
	substr($hdr,0,pos($hdr)//0,'');
	$bad .= $1 if $hdr =~s{\A([^\n]*)\n}{};
	goto parse;
    }
    return $bad;
}

sub parse_reqhdr {
    my ($data,$hdr,$external_length) = @_;
    $data =~m{\A
	([A-Z]{2,20})[\040\t]+          # $1: method
	(\S+)[\040\t]+                  # $2: path/URI
	HTTP/(1\.[01])[\40\t]*          # $3: version
	\r?\n                           # (CR)LF
	([^\r\n].*?\n)?                 # $4: fields
	\r?\n                           # final (CR)LF
    \Z}sx or return "invalid request header";

    my $version = $3;
    my $method  = $1;
    %$hdr = (
	method    => $method,
	url       => $2,
	version   => $version,
	info      => "$method $2 HTTP/$version",
	# fields  -  hash of fields
	# junk    -  bad header fields
	# expect  -  expectations from expect header
	# upgrade -  { websocket => key }
	# content_length
	# chunked
    );

    my %kv;
    my $bad = parse_hdrfields($4,\%kv);
    $hdr->{junk} = $bad if $bad ne '';
    $hdr->{fields} = \%kv;

    if ($version>=1.1 and $kv{expect}) {
	for(@{$kv{expect}}) {
	    # ignore all but 100-continue
	    $hdr->{expect}{lc($1)} = 1 if m{\b(100-continue)\b}i
	}
    }

    # RFC2616 4.4.3:
    # chunked transfer-encoding takes preferece before content-length
    if ( $version >= 1.1 and
	grep { m{(?:^|[ \t,])chunked(?:$|[ \t,;])}i }
	    @{ $kv{'transfer-encoding'} || [] }
    ) {
	$hdr->{chunked} = 1;

    } elsif ( my $cl = $kv{'content-length'} ) {
	return "multiple different content-length header in request"
	    if @$cl>1 and do { my %x; @x{@$cl} = (); keys(%x) } > 1;
	return "invalid content-length '$cl->[0]' in request"
	    if $cl->[0] !~m{^(\d+)$};
	$hdr->{content_length} = $cl->[0];
    }

    if ( $METHODS_WITHOUT_RQBODY{$method} ) {
	# Complain if the client announced a body.
	return "no body allowed with $method"
	    if $hdr->{content_length} or $hdr->{chunked};

    } elsif ( $METHODS_WITH_RQBODY{$method} ) {
	return "content-length or transfer-encoding chunked must be given with method $method"
	    if ! $hdr->{chunked}
	    and ! defined $hdr->{content_length}
	    and ! $external_length;

    } elsif ( ! $hdr->{chunked} ) {
	# if not given content-length is considered 0
	$hdr->{content_length} ||= 0;
    }

    # Connection upgrade
    if ($version >= 1.1 and $kv{upgrade} and my %upgrade
	= map { lc($_) => 1 } map { m{($token)}g } @{$kv{upgrade}}) {
	$hdr->{upgrade} = \%upgrade;
    }

    return; # no error
}

sub parse_rsphdr {
    my ($data,$request,$hdr,$warn) = @_;
    $data =~ m{\A
	HTTP/(1\.[01])[\040\t]+          # $1: version
	(\d\d\d)                         # $2: code
	(?:[\040\t]+([^\r\n]*))?         # $3: reason
	\r?\n
	([^\r\n].*?\n)?                  # $4: fields
	\r?\n                            # empty line
    \Z}sx or return "invalid response header";

    my $version = $1;
    my $code = $2;
    %$hdr = (
	version   => $version,
	code      => $code,
	reason    => $3,
	# fields
	# junk
	# content_length
	# chunked
	# upgrade
	# preliminary
    );

    my %kv;
    my $bad = parse_hdrfields($4,\%kv);
    $hdr->{fields} = \%kv;
    $hdr->{junk} = $bad if $bad ne '';

    if ($code<=199) {
	# Preliminary responses do not contain any body.
	$hdr->{preliminary} = 1;
	$hdr->{content_length} = 0;
	if ($code == 100 and $request->{expect}{'100-continue'}
	    or $code == 102 or $code == 101) {
	    # 100 should only happen with Expect: 100-continue from client
	} else {
	    push @$warn,"unexpected intermediate status code $code" if $warn;
	}
    }

    # Switching Protocols
    # Any upgrade must have both a "Connection: upgrade" and a
    # "Upgrade: newprotocol" header.
    if ($code == 101) {
	my %proto;
	if ($request->{upgrade}
	    and grep { m{\bUPGRADE\b}i } @{$kv{connection} || []}) {
	    for(@{$kv{upgrade} || []}) {
		$proto{lc($_)} = 1 for split(m{\s*[,;]\s*});
	    }
	}

	if (keys(%proto) == 1) {
	    $hdr->{upgrade} = (keys %proto)[0];
	    $hdr->{preliminary} = 0;
	    $hdr->{content_length} = undef;
	} else {
	    return "invalid or unsupported connection upgrade";
	}
    }

    # successful response to CONNECT
    if ($request->{method} eq 'CONNECT' and $code >= 200 and $code < 300) {
	$hdr->{upgrade} = 'CONNECT';
	$hdr->{content_length} = 0;
	delete $hdr->{chunked};
	return;
    }

    # RFC2616 4.4.3:
    # chunked transfer-encoding takes preferece before content-length
    if ( $version >= 1.1 and
	grep { m{(?:^|[ \t,])chunked(?:$|[ \t,;])}i }
	    @{ $kv{'transfer-encoding'} || [] }
    ) {
	$hdr->{chunked} = 1;

    } elsif ( my $cl = $kv{'content-length'} ) {
	return "multiple different content-length header in response"
	    if @$cl>1 and do { my %x; @x{@$cl} = (); keys(%x) } > 1;
	return "invalid content-length '$cl->[0]' in response"
	    if $cl->[0] !~m{^(\d+)$};
	$hdr->{content_length} = $cl->[0];
    }

    if ($CODE_WITHOUT_RPBODY{$code}
	or $METHODS_WITHOUT_RPBODY{$request->{method}}) {
	# no content, even if specified
	$hdr->{content_length} = 0;
	delete $hdr->{chunked};
	return;
    }

    return;
}


sub new_request {
    my $self = shift;
    return $self->{upper_flow}->new_request(@_,$self)
}

# return open requests
sub open_requests {
    my $self = shift;
    my @rq = @_ ? @{$self->{requests}}[@_] : @{$self->{requests}};
    return wantarray
	? map { $_->{obj} ? ($_->{obj}):() } @rq
	: 0 + @rq;
}

sub fatal {
    my ($self,$reason,$dir,$time) = @_;
    %TRACE && $self->xtrace($reason);
}

sub xtrace {
    my $self = shift;
    my $msg = shift;
    $msg = "$$.$self->{connid} $msg";
    unshift @_,$msg;
    goto &trace;
}

sub xdebug {
    $DEBUG or return;
    my $self = shift;
    my $msg = shift;
    $msg = "$$.$self->{connid} $msg";
    unshift @_,$msg;
    goto &debug;
}

sub dump_state {
    $DEBUG or defined wantarray or return;
    my $self = shift;
    my $m = $self->{meta};
    my $msg = sprintf("%s.%d -> %s.%d ",
	$m->{saddr},$m->{sport},$m->{daddr},$m->{dport});
    my $rqs = $self->{requests};
    for( my $i=0;$i<@$rqs;$i++) {
	$msg .= sprintf("request#$i state=%05b %s",
	    $rqs->[$i]{state},$rqs->[$i]{request}{info});
    }
    return $msg if defined wantarray;
    $self->xdebug($msg);
}


{
    package Net::Inspect::L7::HTTP::_DebugRequest;
    sub xdebug {
	my $rq = shift;
	my $msg = shift;
	unshift @_, $rq->{conn}, "#$rq->{reqid} $msg";
	goto &Net::Inspect::L7::HTTP::xdebug;
    }
}

1;

__END__