[pve-devel] [PATCH common] add websocket client implementation

Fabian Grünbichler f.gruenbichler at proxmox.com
Fri Mar 6 11:20:26 CET 2020


based on existing one in pve-client's LXC console handling code by René
Jochum.

it probably would make sense to generalize this further to allow code
sharing with pve-http-server's server implementation.

Signed-off-by: Fabian Grünbichler <f.gruenbichler at proxmox.com>
---
 src/Makefile         |   3 +-
 src/PVE/WebSocket.pm | 356 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 358 insertions(+), 1 deletion(-)
 create mode 100644 src/PVE/WebSocket.pm

diff --git a/src/Makefile b/src/Makefile
index 02f1f56..7eb575a 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -33,7 +33,8 @@ LIB_SOURCES = \
 	SysFSTools.pm \
 	Systemd.pm \
 	Ticket.pm \
-	Tools.pm
+	Tools.pm \
+	WebSocket.pm
 
 all:
 
diff --git a/src/PVE/WebSocket.pm b/src/PVE/WebSocket.pm
new file mode 100644
index 0000000..4cda43d
--- /dev/null
+++ b/src/PVE/WebSocket.pm
@@ -0,0 +1,356 @@
+package PVE::WebSocket;
+
+use strict;
+use warnings;
+
+use Errno qw(EINTR EAGAIN);
+use IO::Socket::SSL;
+use MIME::Base64;
+use Digest::SHA;
+use HTTP::Response;
+use URI::Escape;
+
+my $CRLF = "\x0D\x0A";
+
+sub new {
+    my ($class, $host, $port, $path, %options) = @_;
+
+    my $self = {
+	host => $host,
+	port => $port,
+	path => $path,
+	max_payload_size => $options{max_payload_size} // 128*1024,
+	buf => '',
+    };
+
+    my $ssl_opts = $options{ssl_opts};
+    if (!$ssl_opts) {
+	$ssl_opts->{SSL_verify_mode} = SSL_VERIFY_NONE;
+    }
+
+    my $socket =  IO::Socket::SSL->new(
+	PeerHost => $host,
+	PeerPort => $port,
+	%$ssl_opts,
+	timeout => 30) ||
+	die "failed to connect: $!\n";
+
+    $self->{socket} = $socket;
+
+    return bless $self, $class;
+};
+
+my $wb_socket_read_available_bytes = sub {
+    my ($self) = @_;
+    my $nr = $self->{socket}->sysread($self->{buf}, $self->{max_payload_size}, length($self->{buf}));
+    if (!defined($nr) && !($! == EINTR || $! == EAGAIN)) {
+	die "web socket read error - $!\n";
+    }
+    return $nr;
+};
+
+sub connect {
+    my ($self, $header) = @_;
+
+    my $key = '';
+    $key .= chr(int(rand(256))) for 1 .. 16;
+    my $enckey = MIME::Base64::encode_base64($key, '');
+
+    my $request = "GET $self->{path} HTTP/1.1$CRLF"
+	. "Upgrade: WebSocket$CRLF"
+	. "Connection: Upgrade$CRLF"
+	. "Host: $self->{host}$CRLF"
+	. "Sec-WebSocket-Key: $enckey$CRLF"
+	. "Sec-WebSocket-Version: 13$CRLF"
+	. "Sec-WebSocket-Protocol: binary$CRLF"
+	. ($header ? "${header}$CRLF" : "")
+	. "$CRLF";
+
+    $self->{enckey} = $enckey;
+
+    $self->send($request, 1);
+
+    my $raw_response = '';
+
+    while(1) {
+	my $nr = $wb_socket_read_available_bytes->($self);
+	if ($self->{buf} =~ s/^(.*?)$CRLF$CRLF//s) {
+	    $raw_response = $1;
+	    last;
+	}
+	last if !$nr;
+    };
+
+    my $response = HTTP::Response->parse($raw_response);
+    my $wsaccept = Digest::SHA::sha1_base64("${enckey}258EAFA5-E914-47DA-95CA-C5AB0DC85B11") . "=";
+
+    die "got invalid websocket reponse: $raw_response\n"
+	if !(($response->code == 101) &&
+	     (lc $response->header('connection') eq 'upgrade') &&
+	     (lc $response->header('upgrade') eq 'websocket') &&
+	     ($response->header('sec-websocket-protocol') eq 'binary') &&
+	     ($response->header('sec-websocket-accept') eq $wsaccept));
+
+    return;
+};
+
+sub encode {
+    my ($self, $payload, $opcode) = @_;
+
+    my $string = $opcode ? "$opcode" : "\x82"; # binary frame
+    my $payload_len = length($payload);
+    if ($payload_len <= 125) {
+	$string .= pack 'C', $payload_len | 128;
+    } elsif ($payload_len <= 0xffff) {
+	$string .= pack 'C', 126 | 128;
+	$string .= pack 'n', $payload_len;
+    } else {
+	$string .= pack 'C', 127 | 128;
+	$string .= pack 'Q>', $payload_len;
+    }
+
+    $string .= pack 'N', 0; # we simply use 0 as mask
+    $string .= $payload;
+
+    return $string;
+};
+
+sub send {
+    my ($self, $data, $raw) = @_;
+
+    $data = $self->encode($data) if !$raw;
+
+    my $len = length($data);
+    my $todo = $len;
+    my $offset = 0;
+    while(1) {
+	my $nr = syswrite($self->{socket}, $data, $todo, $offset);
+	if (!defined($nr)) {
+	    next if $! == EINTR || $! == EAGAIN;
+	    die "websocket write error - $!\n"
+	}
+	$offset += $nr;
+	$todo -= $nr;
+	last if $todo <= 0;
+    }
+
+    if ($self->{pong}) {
+	# heartbeat / pong
+	$self->send($self->encode($self->{pong_data}, "\x8A"), 1);
+	$self->{pong} = 0;
+	$self->{pong_data} = undef;
+    }
+
+    return $len;
+};
+
+sub recv {
+    my ($self) = @_;
+
+    my $bytes = $wb_socket_read_available_bytes->($self);
+    if (!defined($bytes)) {
+	return undef;
+    } elsif ($bytes == 0) {
+	return (undef, 0); # EOF
+    } else {
+	my ($payload, $req_close) = $self->decode();
+	return ($payload, $bytes, $req_close);
+    }
+
+}
+
+sub decode {
+    my ($self) = @_;
+
+    my $payload;
+    my $req_close = 0;
+
+    my $buf = \$self->{buf};
+
+    while (my $len = length($$buf)) {
+	last if $len < 2;
+
+	my $hdr = unpack('C', substr($$buf, 0, 1));
+	my $opcode = $hdr & 0b00001111;
+	my $fin = $hdr & 0b10000000;
+
+	die "received fragmented websocket frame\n" if !$fin;
+
+	my $rsv = $hdr & 0b01110000;
+	die "received websocket frame with RSV flags\n" if $rsv;
+
+	my $payload_len = unpack 'C', substr($$buf, 1, 1);
+
+	my $masked = $payload_len & 0b10000000;
+	die "received masked websocket frame from server\n" if $masked;
+
+	my $offset = 2;
+	$payload_len = $payload_len & 0b01111111;
+	if ($payload_len == 126) {
+	    last if $len < 4;
+	    $payload_len = unpack('n', substr($$buf, $offset, 2));
+	    $offset += 2;
+	} elsif ($payload_len == 127) {
+	    last if $len < 10;
+	    $payload_len = unpack('Q>', substr($$buf, $offset, 8));
+	    $offset += 8;
+	}
+
+	die "received too large websocket frame (len = $payload_len)\n"
+	    if ($payload_len > $self->{max_payload_size}) || ($payload_len < 0);
+
+	last if $len < ($offset + $payload_len);
+
+	my $data = substr($$buf, 0, $offset + $payload_len, ''); # now consume data
+
+	my $frame_data = substr($data, $offset, $payload_len);
+
+	if ($opcode == 1 || $opcode == 2) {
+	    # text or binary data
+	    $payload = '' if !defined($payload);
+	    $payload .= $frame_data;
+	    # continue
+	} elsif ($opcode == 8) {
+	    # close received
+	    my $statuscode = unpack ("n", $frame_data);
+	    $req_close = 1;
+	} elsif ($opcode == 9) {
+	    # ping received, schedule pong
+	    $self->{pong} = 1;
+	    $self->{pong_data} = $frame_data;
+	} elsif ($opcode == 0xA) {
+	    # pong received, continue
+	} else {
+	    die "received unhandled websocket opcode $opcode\n";
+	}
+    }
+
+    return ($payload, $req_close);
+};
+
+sub process {
+    my ($self) = @_;
+
+    my $read_select = IO::Select->new;
+    my $write_select = IO::Select->new;
+
+    my $output_buffer = ''; # write buffer for output/writer
+    my $websock_buffer = ''; # write buffer for websocket
+
+    eval {
+	$SIG{TERM} = $SIG{INT} = $SIG{KILL} = sub { die "received interrupt\n"; };
+
+	$read_select->add($self->{socket});
+	my $input_fh = $self->{reader} // \*STDIN;
+	$read_select->add($input_fh);
+
+	my $output_fh = $self->{writer} // \*STDOUT;
+
+	my $max_buffer_len = 256*1024;
+
+	my $drain_buffer = sub {
+	    my ($fh, $buffer_ref) = @_;
+
+	    if (length($$buffer_ref)) {
+		my $nr = syswrite($fh, $$buffer_ref);
+		if (!defined($nr)) {
+		    return if $! == EINTR || $! == EAGAIN;
+		    die "drain buffer - write error - $!\n";
+		}
+		return $nr if !$nr;
+		substr($$buffer_ref, 0, $nr, '');
+	    }
+
+	    $write_select->remove($fh) if !length($$buffer_ref);
+	};
+
+	my $close = 0;
+
+	while (!$close) {
+	    $! = 0;
+	    while(my ($readable, $writable) = IO::Select->select($read_select, $write_select, undef, 3)) {
+		foreach my $fh (@$writable) {
+		    if ($fh == $output_fh) {
+			$drain_buffer->($output_fh, \$output_buffer);
+			$read_select->add($self->{socket})
+			    if length($output_buffer) <= $max_buffer_len;
+		    } elsif ($fh == $self->{socket}) {
+			$drain_buffer->($self->{socket}, \$websock_buffer);
+		    }
+		}
+
+		foreach my $fh (@$readable) {
+		    if ($fh == $self->{socket}) {
+			my $nr = $wb_socket_read_available_bytes->($self);
+			if (!defined($nr)) {
+			    # wait
+			} elsif ($nr == 0) {
+			    $read_select->remove($self->{socket});
+			    $write_select->remove($self->{socket});
+			    $close = 1;
+			    next;
+			} else {
+			    my ($payload, $req_close) = $self->decode();
+			    if (defined($payload) && length($payload)) {
+				$output_buffer .= $payload;
+				$write_select->add($output_fh);
+				if (length($output_buffer) > $max_buffer_len) {
+				    $read_select->remove($self->{socket});
+				}
+			    }
+			    if ($req_close) {
+				$close = 1;
+				next;
+			    }
+			}
+
+		    } elsif ($fh == $input_fh) {
+			my $nr = sysread($input_fh, my $buff, 63*1024);
+			if (!$nr) {
+			    # EOF or error
+			    $read_select->remove($input_fh);
+			    # close connection
+			    if (!$close) {
+				$websock_buffer .= $self->encode(pack('n', 0), "\x88"); # close with status code 0
+				$close = 1;
+				$write_select->add($self->{socket});
+			    }
+			} else {
+			    $websock_buffer .= $self->encode($buff);
+			    $write_select->add($self->{socket});
+			}
+		    }
+		}
+	    }
+
+	    if (!$close) {
+		if ($!) {
+		    die "error processing websocket connection - $!\n";
+		}
+		# heartbeat / ping
+		$websock_buffer .= $self->encode('1', "\x89");
+		$write_select->add($self->{socket});
+	    }
+	}
+    };
+    my $err = $@;
+
+    eval {
+	if ($self->{socket}->connected) {
+	    # close connection
+	    $websock_buffer .= $self->encode(pack('n', 0), "\x88"); # close with status code 0
+	    $self->send($websock_buffer, 1);
+	    $websock_buffer = '';
+	}
+	$self->{socket}->close();
+	$self->{reader}->close() if defined($self->{reader});
+	$self->{writer}->close() if defined($self->{writer});
+    };
+    warn $@ if $@; # show cleanup errors
+
+    print STDERR "\nERROR: $err" if $err;
+
+    return undef;
+}
+
+1;
-- 
2.20.1





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