httpi

#!/usr/bin/perl
use POSIX qw(SIGALRM SIGTERM SIGPIPE SIGHUP sigaction);
$VERSION = "Unknown";

# HTTPi Hypertext Tiny Truncated Process Implementation
# Copyright 1999-2012 Cameron Kaiser and Contributors # All rights reserved
# Please read LICENSE # Do not strip this copyright message.

###############################################################
# WHITE HATS ONLY BELOW THIS POINT -- SEE DOCUMENTATION FIRST #
###############################################################

%system_content_types =
	("html" => "text/html",
	 "htm" => "text/html",
	 "txt" => "text/plain",
	 "xml" => "text/xml",
	 "xsl" => "text/xml",
	 "xhtml" => "application/xhtml+xml",
	 "css" => "text/css",
	 "wml" => "text/vnd.wap.wml",
	 "gif" => "image/gif",
	 "jpeg" => "image/jpeg",
	 "jpg" => "image/jpeg",
	 "bmp" => "image/bmp",
	 "png" => "image/png",
	 "tif" => "image/tiff",
	 "tiff" => "image/tiff",
	 "ico" => "image/x-icon",
	 "svg" => "image/svg+xml",
	 "svgz" => "image/svg+xml",
	 "wbmp" => "image/vnd.wap.wbmp",
	 "wbm" => "image/vnd.wap.wbmp",
	 "xbm" => "image/x-xbitmap",
	 "mp3" => "audio/x-mpeg",
	 "wma" => "audio/x-ms-wma",
	 "wav" => "audio/x-wav",
	 "au" => "audio/basic",
	 "aif" => "audio/x-aiff",
	 "aiff" => "audio/x-aiff",
	 "ogg" => "audio/x-ogg",
	 "oga" => "audio/x-ogg",
	 "mid" => "audio/midi",
	 "wma" => "audio/x-ms-wma",
	 "mpeg" => "video/mpeg",
	 "mpg" => "video/mpeg",
	 "aac" => "audio/aac",
	 "ogv" => "video/x-ogg",
	 "ogx" => "application/x-ogg",
	 "avi" => "video/x-msvideo",
	 "wmv" => "video/x-ms-wmv",
	 "asf" => "video/x-ms-asf",
	 "mov" => "video/quicktime",
	 "mp4" => "video/mp4",
	 "rv" => "video/vnd.m-realvideo",
	 "rm" => "application/vnd.m-realmedia",
	 "ra" => "audio/vnd.m-realaudio",
	 "ram" => "audio/vnd.m-realaudio",
	 "pdf" => "application/pdf",
	 "fdf" => "application/vnd.fdf",
	 "class" => "application/octet-stream",
	 "jar" => "application/octet-stream",
	 "js" => "application/x-javascript",
	 "lnk" => "application/x-hyperlink",
	 "prg" => "application/x-c64-prg-binary",
	 "d64" => "application/x-c64-disk-image",
	 "tar" => "application/x-tar",
	 "sit" => "application/x-stuffit",
	 "Z" => "application/x-compress",
	 "gz"  => "application/x-gzip",
	 "apk" => "application/vnd.android.package-archive",
	 "dmg" => "application/octet-stream",
	 "img" => "application/octet-stream",
	 "lzh" => "application/octet-stream",
	 "lha" => "application/octet-stream",
	 "exe" => "application/octet-stream",
	 "com" => "application/octet-stream",
	 "zip" => "application/x-zip-compressed",
	 "hqx" => "application/x-binhex",
	 "swf" => "x-shockwave-flash",
	 "flv" => "video/x-flv",

	 "bin" => "application/octet-stream");

$logfile = "/dev/null";
$path = "/tmp/htdocs";
$sockaddr = 'S n a4 x8';
$server_host = "ogn-flarm-receiver";
$server_port = "8080";


%content_types =
	("html" => "text/html",
	 "htm" => "text/html");

$headers = <<"EOF";
Server: HTTPi/$VERSION
MIME-Version: 1.0
EOF


%content_types = (%system_content_types, %content_types);
undef %system_content_types;

if ($pid = fork()) { exit; }
$0 = "dhttpi: binding port ...";
$bindthis = pack($sockaddr, 2, 8080, pack('C4', 0, 0, 0, 0));
socket(S, 2, 1, 6);
setsockopt(S, 1, 2, 1);
bind(S, $bindthis) || die("$0: while binding port 8080:\n\"$!\"\n");
listen(S, 128);
$0 = "dhttpi: connected and waiting ANY:8080";

$statiosuptime = time();

sub sock_to_host {
	return ($cache_hn, $cache_port, $cache_ip)
		if (length($cache_ip));

	return (undef, undef, undef) if (!$sock);
	my($AFC, $cache_port, $thataddr, $zero) = unpack($sockaddr, $sock);
	$cache_ip = join('.', unpack("C4", $thataddr));
	$cache_hn =
		$cache_ip;
	return ($cache_hn, $cache_port, $cache_ip);
}


sub htsponse {
	($currentcode, $currentstring) = (@_);
	return if (0+$httpver < 1);
	my($what) = <<"EOF";
HTTP/$httpver $currentcode $currentstring
${headers}Date: $rfcdate
EOF
	$what =~ s/\n/\r\n/g;
	print STDOUT $what;
	&hthead("Connection: close") if (0+$httpver > 1);
}

sub hthead {
	my($header, $term) = (@_);
	return if (0+$httpver < 1);
	print STDOUT "$header\r\n" , ($term) ? "\r\n" : "";
}

sub htcontent {
	my($what, $ctype, $mode) = (@_);
	($contentlength) = $mode || length($what);
	&hthead("Content-Length: $contentlength");
	&hthead("Content-Type: $ctype", 1);
	return if ($method eq 'HEAD' || $mode);
	print STDOUT $what;
}

sub log {
 	if (open(J, ">>$logfile")) {
		my $q = $address . (($variables) ? "?$variables" : "");
		$contentlength += 0;
		$contentlength = 0 if ($method eq 'HEAD');
		my ($hostname, $port, $ip) = &sock_to_host();
		$hostname ||= "-";
		$httpuser ||= "-";
		print J <<"EOF";
$hostname - $httpuser [$date] "$method $q HTTP/$httpver" $currentcode $contentlength "" ""
EOF
		close(J);
	}
}


sub bye { exit; }
sub byebye { kill(9,$secondary_pid) if ($secondary_pid); exit; }

sub dead {
	&htsponse(500, "Server Error");
	&hterror("Server Error", <<"EOF");
The server cannot comply with your request for resource <tt>$::address</tt>.
Please attempt to notify the administrators.
<p>Useful(?) debugging information:
<pre>
@_
</pre>
EOF
	&log; exit;
}

sub generic_signal {
	# this is just a stub, and effectively IGNORE in this version.
}

sub defaultsignals {
	$SIG{'__DIE__'} = \&dead;
	sigaction SIGALRM, new POSIX::SigAction \&bye
		or die "sigalrm failed: $!\n";
	sigaction SIGTERM, new POSIX::SigAction \&byebye
		or die "sigterm failed: $!\n";
	sigaction SIGPIPE, new POSIX::SigAction \&generic_signal
		or die "sigterm failed: $!\n";
	sigaction SIGHUP, new POSIX::SigAction \&generic_signal
		or die "sigterm failed: $!\n";
}
&defaultsignals;

sub alarmsignals {
	undef $SIG{'__DIE__'};
	sigaction SIGALRM, new POSIX::SigAction sub { die; }
		or die "sigalrm failed: $!\n";
}

sub master {
	$0 = "dhttpi: handling request";
$sock = getpeername(STDIN);
$rfcdate = &rfctime(scalar gmtime, 1);
$date = scalar localtime;
($dow, $mon, $dt, $tm, $yr) = ($date =~
	m/(...) (...) (..) (..:..:..) (....)/);
$dt += 0;
$dt = substr("0$dt", length("0$dt") - 2, 2);
$date = "$dt/$mon/$yr:$tm +0000";

select(STDOUT); $|=1; $address = 0; 
alarm 5;
while (<STDIN>) {
	if(/^([A-Z]+)\s+([^\s]+)\s+([^\s\r\l\n]*)/) {
		$method = $1;
		$address = $2;
		$httpver = $3;
		$httpref = '';
		$httpua = '';
		$httpver = ($httpver =~ m#HTTP/([0-9]\.[0-9]+)#) ?
			($1) : (0.9);
		$address =~ s#^http://[^/]+/#/#;
		$0 = $execstring = "dhttpi: $method $address $httpver";
		next unless ($httpver < 1);
	} else {
		s/[\r\l\n\s]+$//;
		(/^Host:\s+(.+)/i) && ($httphost = substr($1, 0, 255))
			&& ($httphost =~ s/:\d+$//);
		(/^Referer:\s+(.+)/i) && ($httpref = substr($1, 0, 1024));
		(/^User-agent:\s+(.+)/i) && ($httpua = substr($1, 0, 1024));
		(/^Content-length:\s+(\d+)/i) &&
			($ENV{'CONTENT_LENGTH'} = $httpcl = 0+$1);
		(/^Content-type:\s+(.+)/i) &&
			($ENV{'CONTENT_TYPE'} = $httpct = substr($1, 0, 255));
		(/^Expect:\s+/) && ($expect = 1);
		(/^Cookie:\s+(.+)/i) &&
			($ENV{'HTTP_COOKIE'} = substr($1, 0, 16384));
		(/^Range:\s+(.+)/i) &&
			($ENV{'CONTENT_RANGE'} = substr($1, 0, 255));
		(/^If-Modified-Since:\s+(.+)/i) &&
			($modsince = $ENV{'HTTP_IF_MODIFIED_SINCE'} =
				substr($1, 0, 255));
		(/^Accept:\s+(.+)/i) &&
			($ENV{'HTTP_ACCEPT'} = substr($1, 0, 255));
		(/^Accept-([a-zA-Z0-9]+):\s+(.+)/i) &&
			($ENV{'HTTP_ACCEPT_'.uc(substr($1, 0, 16))} =
				substr($2, 0, 255));
		(/^X-Requested-With:\s+(.+)/i) &&
			($ENV{'HTTP_X_REQUESTED_WITH'} = substr($1, 0, 1024));
		next unless (/^$/);
	}
	if ($expect) {
		&htsponse(417, "Expectation Failed");
		&hterror("Expectation Failed",
			"The server does not support this method.");
		&log; exit;
	}
	if (!length($address) || (0+$httpver > 1 && !$httphost)) {
		&htsponse(400, "Bad Request");
		&hterror("Bad Request",
			"The server cannot understand your request.");
		&log; exit;
	}
	if ($method !~ /^(GET|HEAD|POST)$/) {
		&htsponse(501, "Not Implemented");
		&hterror("Not Implemented",
			"Only GET, HEAD and POST are supported.");
		&log; exit;
	}
	($address, $variables) = split(/\?/, $address);
	$address =~ s/%([0-9a-fA-F]{2})/pack("H2", $1)/eg;
	$address=~ s#^/?#/#;
	1 while $address =~ s#/\.(/|$)#\1#;
        1 while $address =~ s#/[^/]*/\.\.(/|$)#\1#;
	1 while $address =~ s#^/\.\.(/|$)#\1#;

	alarm 0;




	$raddress = "$path$address"
	;
	1 while ($raddress =~ s#//#/#);
	&hterror301("http://ogn-flarm-receiver:8080$address/")
		if ($address !~ m#/$# && -d $raddress);
	$raddress = (-r "${raddress}index.shtml") ?
		"${raddress}index.shtml" : "${raddress}index.html"
			if (-d $raddress);
	$ENV{'REQUEST_URI'} = $address . (($variables) ? "?$variables" : "");
	delete($ENV{'PATH_INFO'});
	IRED: ($hostname, $port, $ip) = &sock_to_host();
	if(!sysopen(S, $raddress, 0)) { &hterror404; } else {
		if ((-x $raddress)
			) {
			$currentcode = 100; &nsecmodel;
			$ENV{'REQUEST_METHOD'} = $method;
			$ENV{'SERVER_NAME'} = "ogn-flarm-receiver";
			$ENV{'SERVER_PROTOCOL'} = "HTTP/$httpver";
			$ENV{'SERVER_SOFTWARE'} = "HTTPi/$VERSION";
			$ENV{'SERVER_PORT'} = "8080";
			$ENV{'SERVER_URL'} = "http://ogn-flarm-receiver:8080/";
			$ENV{'DOCUMENT_ROOT'} = $path;
			$ENV{'PATH_TRANSLATED'} =
				$ENV{'DOCUMENT_ROOT'} . $ENV{'PATH_INFO'}
				if (length($ENV{'PATH_INFO'}));
			$ENV{'SCRIPT_FILENAME'} = $raddress;
			$ENV{'SCRIPT_NAME'} = $address;
			$ENV{'REMOTE_HOST'} = $hostname;
			$ENV{'REMOTE_ADDR'} = $ip;
			$ENV{'REMOTE_PORT'} = $port;
			$ENV{'QUERY_STRING'} = $variables;
			$ENV{'HTTP_USER_AGENT'} = $httpua;
			$ENV{'HTTP_REFERER'} = $httpref;
			undef $pid;
			if ($pid = fork()) { kill 15, $$; exit; }
			elsif (!defined($pid)) {
				die
			"temporary(?) fork error, please retry request: $!\n";
			} else {
				$ENV{'PATH'} = '';
				($raddress =~ /^(.+)$/) && ($raddress = $1);
				if ($method eq 'POST') {
					open(W, "|$raddress") || die
						"can't POST to $raddress";
					read(STDIN, $buf, $httpcl);
					print W $buf;
					exit;
				}
				exec "$raddress", "$variables";
				die "exec() returned -1";
			}
		}
		($x,$x,$x,$x,$x,$x,$x,$length,$x,$mtime) = stat(S);
		$ctype = 0;
		foreach(keys %content_types) {
			if ($raddress =~ /\.$_$/i) {
				$ctype = $content_types{$_};
			}
		}
		$mtime = &rfctime($mtime);
SERVEIT:
		if ($mtime eq $modsince) {
			&htsponse(304, "Not Modified");
			&hthead("Last-Modified: $mtime", 1);
			&log; exit;
		}
		$ctype ||= 'text/plain';
		if ($pid = fork()) { kill 15, $$; exit; }
		$contentlength ||= $length;
			&htsponse(200, "OK");
			&hthead("Last-Modified: $mtime");
			&htcontent("", $ctype, $length);
			&nsecmodel;
			$bytecount = 0;
			unless ($method eq 'HEAD') {
				while(!eof(S)) {
					read(S, $q, 32768);
					print STDOUT $q;
					$bytecount += 32768;
					$0 = $execstring .
						" ($bytecount bytes sent)";
				}
			}
		alarm 0;
	}
	exit;
}

exit;
}


sub nsecmodel {
	&log;
	($x,$x,$x,$x,$uid,$gid) = stat(S);
	(!$uid || !$gid || $uid < 1000) &&
		die "resource is root-owned, secured or not stat-able\n";
	if (!$<) {
		($) = "$gid $gid") || die "can't set egid to $gid";
		($> = $uid) || die "can't set euid to $uid";
		($( = "$gid $gid") || die "can't set rgid to $gid";
		($< = $uid) || die "can't set ruid to $uid";
	}
}

sub rfctime {
	my $mtime = shift;
	$mtime = (scalar gmtime $mtime) if (!(shift));
	my ($dow, $mon, $dt, $tm, $yr) =
		($mtime =~ m/(...) (...) (..) (..:..:..) (....)/);
	$dt += 0; $yr += 0;
	return "$dow, $dt $mon $yr $tm GMT";
}

sub hterror {
	my($errstr, @expl) = (@_);
	&htcontent(<<"EOF", "text/html");
<html>
<body>
<h1>$errstr</h1>
@expl
<hr>
<address><a href = "http://httpi.floodgap.com/">httpi/$VERSION</a>
by Cameron Kaiser</address>
</body>
</html>
EOF
	}

sub hterror404 {
	&htsponse(404, "Not Found");
	&hterror("Not Found",
		"The resource <tt>$address</tt> was not found on this system.");
	&log; exit;
}

sub hterror301 {
	&htsponse(301, "Moved Permanently");
	&hthead("Location: @_");
	&hterror("Resource Moved Permanently",
		"This resource has moved <a href = \"@_\">here</a>.");
	&log; exit;
}


$0 = "dhttpi: on ANY:8080, ready!";
$master_pid = $$;
for (;;) {
	if ($secondary_pid = fork()) {
		waitpid($secondary_pid, 0);
		$0 = "dhttpi: on ANY:8080, last request " .
			scalar localtime;
	} else {
		$0 = "dhttpi (child of $master_pid): waiting for connect";
		$addr=accept(NS,S);
		open(STDIN, "<&NS");
		open(STDOUT, ">&NS");
		&defaultsignals;
		&master;
		exit;
	}
}