tcp: fix SO_RCVLOWAT and RCVBUF autotuning
Applications might use SO_RCVLOWAT on TCP socket hoping to receive
one [E]POLLIN event only when a given amount of bytes are ready in socket
receive queue.
Problem is that receive autotuning is not aware of this constraint,
meaning sk_rcvbuf might be too small to allow all bytes to be stored.
Add a new (struct proto_ops)->set_rcvlowat method so that a protocol
can override the default setsockopt(SO_RCVLOWAT) behavior.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/net.h b/include/linux/net.h
index 2248a05..6554d3b 100644
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -197,6 +197,7 @@ struct proto_ops {
int offset, size_t size, int flags);
int (*sendmsg_locked)(struct sock *sk, struct msghdr *msg,
size_t size);
+ int (*set_rcvlowat)(struct sock *sk, int val);
};
#define DECLARE_SOCKADDR(type, dst, src) \