A disabling repair mode drops SO_REUSEADDR.
We can set SO_REUSEADDR after disabling repair mode, but
a small race window exists in this case.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
All sockets are created with SO_REUSEADDR, it's needed for restoring.
E.g.: A listen socket is created after a connected socket. Both of them
are binded to one port.
So SO_REUSEADDR should be restored, when all sockets on a port were created.
This code creates a structure for each port of one type of sockets
and accounts a number of sockets, which are not restored yet.
Sockets have a hook post_open(), in which it waits when all sockets for
a defined port would be created and then it will restore SO_REUSEADDR.
struct port contains a type (udp, tcp, etc) and a port number.
It doesn't contain family or addr, because it's extra loads of logic,
which doesn't bring a significant profits.
v2: fix according with comments from Pavel
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
What it does is uses the tcp repair engine from the kernel.
On dump the connection is locked with netfilter, socket is put
in the repair state and then its internals are dumped.
On restore we create a socket, put it into repair, dress it up
and then unlock all the connections at the very end.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
When dump finished with error we should unlock all locked
previously connections.
When restoring we should collect connctions and unlock them
all at the end.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
First of all -- to make crtools dump/restore established tcp sockets
you have to specify the --tcp-established options. By doing so you
inform crtools that
a) you know, that after dump there will be a netfilter rules blocking
the dumped connections
b) you guarantee, that before restore this netfilter block is still
there
What else this patch does is simple -- collects establised sockets and
calls the dump/restore tcp function (now empty) where appropriate.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
