[pve-devel] [PATCH common 2/2] daemon: explicitly bind to wildcard address.

[Stoiko Ivanov]

with the recent change in pve-manager pveproxy (and spiceproxy)
try binding to '::' per default. This fails for hosts having disabled
ipv6 via kernel commandline.

Our desired behavior of binding on '::' and only falling back to
'0.0.0.0' in case this is not supported is not directly possible with
IO::Socket::IP->new (or rather by Socket::GetAddrInfo, which at least
on my system always returns the v4 wildcard-address first).

the code now binds to:
* the provided $host if not undef
* '::' if $host is not set
* '0.0.0.0' if $host is not set and binding on '::' yields an error

Signed-off-by: Stoiko Ivanov <s.ivanov at proxmox.com>
---
 src/PVE/Daemon.pm | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/src/PVE/Daemon.pm b/src/PVE/Daemon.pm
index 79b90ad..f4786b8 100644
--- a/src/PVE/Daemon.pm
+++ b/src/PVE/Daemon.pm
@@ -819,14 +819,24 @@ sub create_reusable_socket {
 	$socket->fcntl(Fcntl::F_SETFD(), Fcntl::FD_CLOEXEC);
     } else {
 
-	$socket = IO::Socket::IP->new(
-	    LocalHost => $host,
+	my %sockargs = (
 	    LocalPort => $port,
 	    Listen => SOMAXCONN,
 	    Proto  => 'tcp',
 	    GetAddrInfoFlags => 0,
-	    ReuseAddr => 1) ||
-	    die "unable to create socket - $@\n";
+	    ReuseAddr => 1,
+	);
+	if (defined($host)) {
+	    $socket = IO::Socket::IP->new( LocalHost => $host, %sockargs) ||
+		die "unable to create socket - $@\n";
+	} else {
+	    # disabling AF_INET6 (by adding ipv6.disable=1 to the kernel cmdline)
+	    # causes bind on :: to fail, try 0.0.0.0 in that case
+	    $socket = IO::Socket::IP->new( LocalHost => '::', %sockargs);
+
+	    $socket = IO::Socket::IP->new( LocalHost => '0.0.0.0', %sockargs) if $@;
+	    die "unable to create socket - $@\n" if !$socket;
+	}
 
 	# we often observe delays when using Nagle algorithm,
 	# so we disable that to maximize performance
-- 
2.20.1