Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 8550f328 authored by Lawrence Brakmo's avatar Lawrence Brakmo Committed by David S. Miller
Browse files

bpf: Support for per connection SYN/SYN-ACK RTOs 



This patch adds support for setting a per connection SYN and
SYN_ACK RTOs from within a BPF_SOCK_OPS program. For example,
to set small RTOs when it is known both hosts are within a
datacenter.

Signed-off-by: default avatarLawrence Brakmo <brakmo@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ae16189e

include/net/tcp.h

+11 −0
Original line number Diff line number Diff line
@@ -2057,4 +2057,15 @@ static inline int tcp_call_bpf(struct sock *sk, int op) 
}

#endif



static inline u32 tcp_timeout_init(struct sock *sk)

{

	int timeout;



	timeout = tcp_call_bpf(sk, BPF_SOCK_OPS_TIMEOUT_INIT);



	if (timeout <= 0)

		timeout = TCP_TIMEOUT_INIT;

	return timeout;

}



#endif	/* _TCP_H */

include/uapi/linux/bpf.h

+3 −0
Original line number Diff line number Diff line
@@ -748,6 +748,9 @@ struct bpf_sock_ops { 
 */

enum {

	BPF_SOCK_OPS_VOID,

	BPF_SOCK_OPS_TIMEOUT_INIT,	/* Should return SYN-RTO value to use or

					 * -1 if default value should be used

					 */

};



#endif /* _UAPI__LINUX_BPF_H__ */

net/ipv4/tcp_input.c

+2 −1
Original line number Diff line number Diff line
@@ -6406,7 +6406,8 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, 
	} else {

		tcp_rsk(req)->tfo_listener = false;

		if (!want_cookie)

			inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);

			inet_csk_reqsk_queue_hash_add(sk, req,

				tcp_timeout_init((struct sock *)req));

		af_ops->send_synack(sk, dst, &fl, req, &foc,

				    !want_cookie ? TCP_SYNACK_NORMAL :

						   TCP_SYNACK_COOKIE);

net/ipv4/tcp_output.c

+1 −1
Original line number Diff line number Diff line
@@ -3326,7 +3326,7 @@ static void tcp_connect_init(struct sock *sk) 
	tp->rcv_wup = tp->rcv_nxt;

	tp->copied_seq = tp->rcv_nxt;



	inet_csk(sk)->icsk_rto = TCP_TIMEOUT_INIT;

	inet_csk(sk)->icsk_rto = tcp_timeout_init(sk);

	inet_csk(sk)->icsk_retransmits = 0;

	tcp_clear_retrans(tp);

}