Commit graph

4 commits

Author SHA1 Message Date
David Gibson
acca4235c4 flow, tcp: Generalise TCP hash table to general flow hash table
Move the data structures and helper functions for the TCP hash table to
flow.c, making it a general hash table indexing sides of flows.  This is
largely code motion and straightforward renames.  There are two semantic
changes:

 * flow_lookup_af() now needs to verify that the entry has a matching
   protocol and interface as well as matching addresses and ports.

 * We double the size of the hash table, because it's now at least
   theoretically possible for both sides of each flow to be hashed.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-07-19 18:32:59 +02:00
David Gibson
52d45f1737 tcp: Obtain guest address from flowside
Currently we always deliver inbound TCP packets to the guest's most
recent observed IP address.  This has the odd side effect that if the
guest changes its IP address with active TCP connections we might
deliver packets from old connections to the new address.  That won't
work; it will probably result in an RST from the guest.  Worse, if the
guest added a new address but also retains the old one, then we could
break those old connections by redirecting them to the new address.

Now that we maintain flowside information, we have a record of the correct
guest side address and can just use it.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-07-19 18:32:44 +02:00
David Gibson
f9fe212b1f tcp, flow: Remove redundant information, repack connection structures
Some information we explicitly store in the TCP connection is now
duplicated in the common flow structure.  Access it from there instead, and
remove it from the TCP specific structure.   With that done we can reorder
both the "tap" and "splice" TCP structures a bit to get better packing for
the new combined flow table entries.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-07-19 18:32:41 +02:00
Laurent Vivier
fba2b544b6 tcp: move buffers management functions to their own file
Move all the TCP parts using internal buffers to tcp_buf.c
and keep generic TCP management functions in tcp.c.
Add tcp_internal.h to export needed functions from tcp.c and
tcp_buf.h from tcp_buf.c

With this change we can use existing TCP functions with a
different kind of memory storage as for instance the shared
memory provided by the guest via vhost-user.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-06-13 15:45:05 +02:00