net: bpf: Use the protocol's set_rcvlowat behavior if there is one

The commit d1361840f8c5 ("tcp: fix SO_RCVLOWAT and RCVBUF autotuning")
add one new (struct proto_ops)->set_rcvlowat method so that a protocol
can override the default setsockopt(SO_RCVLOWAT) behavior.

The prior bpf codes don't check and invoke the protos's set_rcvlowat,
now correct it.

Signed-off-by: Gao Feng <gfree.wind@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/filter.c b/net/core/filter.c
index 5669248..e8508aa 100644 (file)
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5063,7 +5063,10 @@ static int __bpf_setsockopt(struct sock *sk, int level, int optname,
                case SO_RCVLOWAT:
                        if (val < 0)
                                val = INT_MAX;
-                       WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
+                       if (sk->sk_socket && sk->sk_socket->ops->set_rcvlowat)
+                               ret = sk->sk_socket->ops->set_rcvlowat(sk, val);
+                       else
+                               WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
                        break;
                case SO_MARK:
                        if (sk->sk_mark != val) {