diff options
| author | Paolo Abeni <pabeni@redhat.com> | 2025-04-07 17:45:41 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-04-08 18:19:41 -0700 |
| commit | a36283e2b683f172aa1760c77325e50b16c0f792 (patch) | |
| tree | de9d96061c23b493d9bb2d457c0bb113ca29269f /include/linux | |
| parent | 5ac40e6b5b0bac3f72020a48d01ada23e8450d0c (diff) | |
udp_tunnel: create a fastpath GRO lookup.
Most UDP tunnels bind a socket to a local port, with ANY address, no
peer and no interface index specified.
Additionally it's quite common to have a single tunnel device per
namespace.
Track in each namespace the UDP tunnel socket respecting the above.
When only a single one is present, store a reference in the netns.
When such reference is not NULL, UDP tunnel GRO lookup just need to
match the incoming packet destination port vs the socket local port.
The tunnel socket never sets the reuse[port] flag[s]. When bound to no
address and interface, no other socket can exist in the same netns
matching the specified local port.
Matching packets with non-local destination addresses will be
aggregated, and eventually segmented as needed - no behavior changes
intended.
Restrict the optimization to kernel sockets only: it covers all the
relevant use-cases, and user-space owned sockets could be disconnected
and rebound after setup_udp_tunnel_sock(), breaking the uniqueness
assumption
Note that the UDP tunnel socket reference is stored into struct
netns_ipv4 for both IPv4 and IPv6 tunnels. That is intentional to keep
all the fastpath-related netns fields in the same struct and allow
cacheline-based optimization. Currently both the IPv4 and IPv6 socket
pointer share the same cacheline as the `udp_table` field.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/41d16bc8d1257d567f9344c445b4ae0b4a91ede4.1744040675.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/udp.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/include/linux/udp.h b/include/linux/udp.h index 0807e21cfec9..895240177f4f 100644 --- a/include/linux/udp.h +++ b/include/linux/udp.h @@ -101,6 +101,13 @@ struct udp_sock { /* Cache friendly copy of sk->sk_peek_off >= 0 */ bool peeking_with_offset; + + /* + * Accounting for the tunnel GRO fastpath. + * Unprotected by compilers guard, as it uses space available in + * the last UDP socket cacheline. + */ + struct hlist_node tunnel_list; }; #define udp_test_bit(nr, sk) \ @@ -219,4 +226,13 @@ static inline void udp_allow_gso(struct sock *sk) #define IS_UDPLITE(__sk) (__sk->sk_protocol == IPPROTO_UDPLITE) +static inline struct sock *udp_tunnel_sk(const struct net *net, bool is_ipv6) +{ +#if IS_ENABLED(CONFIG_NET_UDP_TUNNEL) + return rcu_dereference(net->ipv4.udp_tunnel_gro[is_ipv6].sk); +#else + return NULL; +#endif +} + #endif /* _LINUX_UDP_H */ |