lxc enter: cleanup filehandle usage

[pve-client.git] / PVE / APIClient / Commands / lxc.pm

diff --git a/PVE/APIClient/Commands/lxc.pm b/PVE/APIClient/Commands/lxc.pm
index e0d21ae935d1d2a34dfa53ecacaa8096b2cbd276..650b6b5273e9cdf8cfa9f052afa5659a2aebf090 100644 (file)
--- a/PVE/APIClient/Commands/lxc.pm
+++ b/PVE/APIClient/Commands/lxc.pm
@@ -244,7 +244,11 @@ __PACKAGE__->register_method ({
        my $old_termios = PVE::PTY::tcgetattr(*STDIN);
        my $raw_termios = {%$old_termios};
 
-       my $select = IO::Select->new;
+       my $read_select = IO::Select->new;
+       my $write_select = IO::Select->new;
+
+       my $output_buffer = ''; # write buffer for STDOUT
+       my $websock_buffer = ''; # write buffer for $web_socket
 
        eval {
            $SIG{TERM} = $SIG{INT} = $SIG{KILL} = sub { die "received interrupt\n"; };
@@ -254,17 +258,60 @@ __PACKAGE__->register_method ({
 
            # And set it to non-blocking so we can every char with IO::Select.
            STDIN->blocking(0);
-
            $web_socket->blocking(1);
-           $select->add($web_socket);
-           my $input_fh = fileno(STDIN);
-           $select->add($input_fh);
+           $read_select->add($web_socket);
+           my $input_fh = \*STDIN;
+           $read_select->add($input_fh);
+
+           my $output_fh = \*STDOUT;
 
            my $ctrl_a_pressed_before = 0;
 
+           my $winch_received = 0;
+           $SIG{WINCH} = sub { $winch_received = 1; };
+
+           my $check_terminal_size = sub {
+               my ($ncols, $nrows) = PVE::PTY::tcgetsize(*STDIN);
+               if ($ncols != $columns or $nrows != $rows) {
+                   $columns = $ncols;
+                   $rows = $nrows;
+                   $websock_buffer .= $create_websockt_frame->("1:$columns:$rows:");
+                   $write_select->add($web_socket);
+               }
+               $winch_received = 0;
+           };
+
+           my $max_buffer_len = 256*1024;
+
+           my $drain_buffer = sub {
+               my ($fh, $buffer_ref) = @_;
+
+               my $len = length($$buffer_ref);
+               my $nr = syswrite($fh, $$buffer_ref);
+               if (!defined($nr)) {
+                   next if $! == EINTR || $! == EAGAIN;
+                   die "drain buffer - write error - $!\n";
+               }
+               return $nr if !$nr;
+               substr($$buffer_ref, 0, $nr, '');
+               $len = length($$buffer_ref);
+               $write_select->remove($fh) if !$len;
+           };
+
            while (1) {
-               while(my @ready = $select->can_read(3)) {
-                   foreach my $fh (@ready) {
+               while(my ($readable, $writable) = IO::Select->select($read_select, $write_select, undef, 3)) {
+                   $check_terminal_size->() if $winch_received;
+
+                   foreach my $fh (@$writable) {
+                       if ($fh == $output_fh) {
+                           $drain_buffer->($output_fh, \$output_buffer);
+                           $read_select->add($web_socket) if length($output_buffer) <= $max_buffer_len;
+                       } elsif ($fh == $web_socket) {
+                           $drain_buffer->($web_socket, \$websock_buffer);
+                       }
+                   }
+
+                   foreach my $fh (@$readable) {
 
                        if ($fh == $web_socket) {
                            # Read from WebSocket
@@ -276,8 +323,12 @@ __PACKAGE__->register_method ({
                                return; # EOF
                            } else {
                                my ($payload, $req_close) = $parse_web_socket_frame->(\$wsbuf);
-                               if ($payload) {
-                                   $full_write->(\*STDOUT, $payload);
+                               if (defined($payload) && length($payload)) {
+                                   $output_buffer .= $payload;
+                                   $write_select->add($output_fh);
+                                   if (length($output_buffer) > $max_buffer_len) {
+                                       $read_select->remove($web_socket);
+                                   }
                                }
                                return if $req_close;
                            }
@@ -285,7 +336,7 @@ __PACKAGE__->register_method ({
                        } elsif ($fh == $input_fh) {
                            # Read from STDIN
 
-                           my $nr = read(\*STDIN, my $buff, 4096);
+                           my $nr = sysread($input_fh, my $buff, 4096);
                            return if !$nr; # EOF or error
 
                            my $char = ord($buff);
@@ -295,13 +346,16 @@ __PACKAGE__->register_method ({
 
                            $ctrl_a_pressed_before = ($char == hex("0x01") && $ctrl_a_pressed_before == 0) ? 1 : 0;
 
-                           my $frame = $create_websockt_frame->("0:" . $nr . ":" . $buff);
-                           $full_write->($web_socket, $frame);
+                           $websock_buffer .= $create_websockt_frame->("0:" . $nr . ":" . $buff);
+                           $write_select->add($web_socket);
                        }
                    }
                }
+               $check_terminal_size->() if $winch_received;
+
                # got timeout
-               $full_write->($web_socket, $create_websockt_frame->("2")); # ping server to keep connection alive
+               $websock_buffer .= $create_websockt_frame->("2"); # ping server to keep connection alive
+               $write_select->add($web_socket);
            }
        };
        my $err = $@;
@@ -313,13 +367,17 @@ __PACKAGE__->register_method ({
 
            if ($web_socket->connected) {
                # close connection
-               my $msg = "\x88" . pack('N', 0) . pack('n', 0); # Opcode, mask, statuscode
-               $full_write->($web_socket, $msg);
+               $websock_buffer .= "\x88" . pack('N', 0) . pack('n', 0); # Opcode, mask, statuscode
+               $full_write->($web_socket, $websock_buffer);
+               $websock_buffer = '';
                close($web_socket);
            }
 
            # Reset the terminal parameters.
-           $full_write->(\*STDOUT, "\e[24H\r\n");
+           $output_buffer .= "\e[24H\r\n";
+           $full_write->(\*STDOUT, $output_buffer);
+           $output_buffer = '';
+
            PVE::PTY::tcsetattr(*STDIN, $old_termios);
        };
        warn $@ if $@; # show cleanup errors