sock: Introduce sk->sk_prot->psock_update_sk_prot()

Currently sockmap calls into each protocol to update the struct
proto and replace it. This certainly won't work when the protocol
is implemented as a module, for example, AF_UNIX.

Introduce a new ops sk->sk_prot->psock_update_sk_prot(), so each
protocol can implement its own way to replace the struct proto.
This also helps get rid of symbol dependencies on CONFIG_INET.

Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210331023237.41094-11-xiyou.wangcong@gmail.com
This commit is contained in:
Cong Wang
2021-03-30 19:32:31 -07:00
committed by Alexei Starovoitov
parent a7ba4558e6
commit 8a59f9d1e3
12 changed files with 58 additions and 45 deletions

View File

@@ -41,12 +41,23 @@ static int __init udp_bpf_v4_build_proto(void)
}
core_initcall(udp_bpf_v4_build_proto);
struct proto *udp_bpf_get_proto(struct sock *sk, struct sk_psock *psock)
int udp_bpf_update_proto(struct sock *sk, bool restore)
{
int family = sk->sk_family == AF_INET ? UDP_BPF_IPV4 : UDP_BPF_IPV6;
struct sk_psock *psock = sk_psock(sk);
if (restore) {
sk->sk_write_space = psock->saved_write_space;
/* Pairs with lockless read in sk_clone_lock() */
WRITE_ONCE(sk->sk_prot, psock->sk_proto);
return 0;
}
if (sk->sk_family == AF_INET6)
udp_bpf_check_v6_needs_rebuild(psock->sk_proto);
return &udp_bpf_prots[family];
/* Pairs with lockless read in sk_clone_lock() */
WRITE_ONCE(sk->sk_prot, &udp_bpf_prots[family]);
return 0;
}
EXPORT_SYMBOL_GPL(udp_bpf_update_proto);