[pve-devel] [PATCH storage] fix insecure migration failing if waiting on lock

[Mira Limbeck]

both STDOUT and STDERR are written into `$info` which is then parsed for
IP and port of the target socket listening.
when the ports file can't be locked immediately `trying to acquire
lock...` is printed on STDERR and in turn written into `$info`.
trying to parse the IP then fails, resulting in a migration or
replication failing.

the bare open3 call is replaced by the run_command wrapper from
pve-common to use a safe wrapper around open3 with the same
functionality.
STDERR is now read separately from STDOUT and the last line of STDERR
is kept in case of errors.

Signed-off-by: Mira Limbeck <m.limbeck at proxmox.com>
---
I've replaced open3 with run_command on recommendation from others. tt
complicates the logic a little bit compared to the `simple` open3
solution, but may be less error prone since run_command abstracts open3
nicely behind a safe wrapper.

one thing I could not verify was the now removed line:
`if (!close($info)) { # does waitpid()`

I could not find any information mentioning this behavior of close() on
a simple file.


 src/PVE/Storage.pm | 79 +++++++++++++++++++++++++---------------------
 1 file changed, 43 insertions(+), 36 deletions(-)

diff --git a/src/PVE/Storage.pm b/src/PVE/Storage.pm
index 40314a8..b6045d5 100755
--- a/src/PVE/Storage.pm
+++ b/src/PVE/Storage.pm
@@ -851,44 +851,51 @@ sub storage_migrate {
 
     eval {
 	if ($insecure) {
-	    my $input = IO::File->new();
-	    my $info = IO::File->new();
-	    open3($input, $info, $info, @$recv)
-		or die "receive command failed: $!\n";
-	    close($input);
-
-	    my $try_ip = <$info> // '';
-	    my ($ip) = $try_ip =~ /^($PVE::Tools::IPRE)$/ # untaint
-		or die "no tunnel IP received, got '$try_ip'\n";
-
-	    my $try_port = <$info> // '';
-	    my ($port) = $try_port =~ /^(\d+)$/ # untaint
-		or die "no tunnel port received, got '$try_port'\n";
-
-	    my $socket = IO::Socket::IP->new(PeerHost => $ip, PeerPort => $port, Type => SOCK_STREAM)
-		or die "failed to connect to tunnel at $ip:$port\n";
-	    # we won't be reading from the socket
-	    shutdown($socket, 0);
-
-	    eval { run_command($cmds, output => '>&'.fileno($socket), errfunc => $match_volid_and_log); };
-	    my $send_error = $@;
-
-	    # don't close the connection entirely otherwise the receiving end
-	    # might not get all buffered data (and fails with 'connection reset by peer')
-	    shutdown($socket, 1);
-
-	    # wait for the remote process to finish
-	    while (my $line = <$info>) {
-		$match_volid_and_log->("[$target_sshinfo->{name}] $line");
+	    my $last_err = '';
+	    my $ip;
+	    my $port;
+	    my $socket;
+	    my $send_error;
+	    my $handle_insecure_migration = sub {
+		my $line = shift;
+
+		if (!$ip) {
+		    if ($line =~ /^($PVE::Tools::IPRE)$/) {
+			$ip = $1;
+		    } else {
+			die "no tunnel IP received, got $line\n";
+		    }
+		} elsif(!$port) {
+		    if ($line =~ /^(\d+)$/) {
+			$port = $1;
+		    } else {
+			die "no tunnel port received, got $line\n";
+		    }
+		}
+		if ($ip && $port && !$socket) {
+		    # create socket, run command
+		    $socket = IO::Socket::IP->new(PeerHost => $ip, PeerPort => $port, Type => SOCK_STREAM)
+			or die "failed to connect to tunnel at $ip:$port\n";
+		    # we won't be reading from the socket
+		    shutdown($socket, 0);
+
+		    eval { run_command($cmds, output => '>&'.fileno($socket), errfunc => $match_volid_and_log); };
+		    $send_error = $@;
+
+		    # don't close the connection entirely otherwise the receiving end
+		    # might not get all buffered data (and fails with 'connection reset by peer')
+		    shutdown($socket, 1);
+		} elsif ($ip && $port) {
+		    $match_volid_and_log->("[$target_sshinfo->{name}] $line");
+		}
+	    };
+	    eval { run_command($recv, outfunc => $handle_insecure_migration, errfunc => sub { $last_err = shift; }); };
+	    if (my $err = $@) {
+		chomp($err);
+		die "failed to run insecure migration: $err - $last_err\n";
 	    }
-
 	    # now close the socket
-	    close($socket);
-	    if (!close($info)) { # does waitpid()
-		die "import failed: $!\n" if $!;
-		die "import failed: exit code ".($?>>8)."\n";
-	    }
-
+	    close($socket) if $socket;
 	    die $send_error if $send_error;
 	} else {
 	    push @$cmds, $recv;
-- 
2.39.2