From 8fb1a76a0f35c45a424c9eb84b0f97ffd51e6052 Mon Sep 17 00:00:00 2001 From: Kui-Feng Lee Date: Wed, 22 Mar 2023 20:23:59 -0700 Subject: net: Update an existing TCP congestion control algorithm. This feature lets you immediately transition to another congestion control algorithm or implementation with the same name. Once a name is updated, new connections will apply this new algorithm. The purpose is to update a customized algorithm implemented in BPF struct_ops with a new version on the flight. The following is an example of using the userspace API implemented in later BPF patches. link = bpf_map__attach_struct_ops(skel->maps.ca_update_1); ....... err = bpf_link__update_map(link, skel->maps.ca_update_2); We first load and register an algorithm implemented in BPF struct_ops, then swap it out with a new one using the same name. After that, newly created connections will apply the updated algorithm, while older ones retain the previous version already applied. This patch also takes this chance to refactor the ca validation into the new tcp_validate_congestion_control() function. Cc: netdev@vger.kernel.org, Eric Dumazet Signed-off-by: Kui-Feng Lee Link: https://lore.kernel.org/r/20230323032405.3735486-3-kuifeng@meta.com Signed-off-by: Martin KaFai Lau --- include/net/tcp.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include') diff --git a/include/net/tcp.h b/include/net/tcp.h index db9f828e9d1e..2abb755e6a3a 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1117,6 +1117,9 @@ struct tcp_congestion_ops { int tcp_register_congestion_control(struct tcp_congestion_ops *type); void tcp_unregister_congestion_control(struct tcp_congestion_ops *type); +int tcp_update_congestion_control(struct tcp_congestion_ops *type, + struct tcp_congestion_ops *old_type); +int tcp_validate_congestion_control(struct tcp_congestion_ops *ca); void tcp_assign_congestion_control(struct sock *sk); void tcp_init_congestion_control(struct sock *sk); -- cgit v1.2.3-58-ga151