...and time out after that. This will be needed because of an upcoming
change to passt-repair enabling it to start before passt is started,
on both source and target, by means of an inotify watch.
Once the inotify watch triggers, passt-repair will connect right away,
but we have no guarantees that the connection completes before we
start the migration process, so wait for it (for a reasonable amount
of time).
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
This implements flow preparation on the source, transfer of data with
a format roughly inspired by struct tcp_tap_conn, plus a specific
structure for parameters that don't fit in the flow table, and flow
insertion on the target, with all the appropriate window options,
window scaling, MSS, etc.
Contents of pending queues are transferred as well.
The target side is rather convoluted because we first need to create
sockets and switch them to repair mode, before we can apply options
that are *not* stored in the flow table. This also means that, if
we're testing this on the same machine, in the same namespace, we need
to close the listening socket on the source before we can start moving
data.
Further, we need to connect() the socket on the target before we can
restore data queues, but we can't do that (again, on the same machine)
as long as the matching source socket is open, which implies an
arbitrary limit on queue sizes we can transfer, because we can only
dump pending queues on the source as long as the socket is open, of
course.
Co-authored-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Tested-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
In vhost-user mode, by default, create a second UNIX domain socket
accepting connections from passt-repair, with the usual listener
socket.
When we need to set or clear TCP_REPAIR on sockets, we'll send them
via SCM_RIGHTS to passt-repair, who sets the socket option values we
ask for.
To that end, introduce batched functions to request TCP_REPAIR
settings on sockets, so that we don't have to send a single message
for each socket, on migration. When needed, repair_flush() will
send the message and check for the reply.
Co-authored-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
