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Commit 9872a4bd authored by Lawrence Brakmo's avatar Lawrence Brakmo Committed by David S. Miller
Browse files

bpf: Add TCP connection BPF callbacks 



Added callbacks to BPF SOCK_OPS type program before an active
connection is intialized and after a passive or active connection is
established.

The following patch demostrates how they can be used to set send and
receive buffer sizes.

Signed-off-by: default avatarLawrence Brakmo <brakmo@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8c4b4c7e

include/uapi/linux/bpf.h

+11 −0
Original line number Diff line number Diff line
@@ -767,6 +767,17 @@ enum { 
					 * window (in packets) or -1 if default

					 * value should be used

					 */

	BPF_SOCK_OPS_TCP_CONNECT_CB,	/* Calls BPF program right before an

					 * active connection is initialized

					 */

	BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB,	/* Calls BPF program when an

						 * active connection is

						 * established

						 */

	BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB,	/* Calls BPF program when a

						 * passive connection is

						 * established

						 */

};



#endif /* _UAPI__LINUX_BPF_H__ */

net/ipv4/tcp_fastopen.c

+1 −0
Original line number Diff line number Diff line
@@ -221,6 +221,7 @@ static struct sock *tcp_fastopen_create_child(struct sock *sk, 
	tcp_init_congestion_control(child);

	tcp_mtup_init(child);

	tcp_init_metrics(child);

	tcp_call_bpf(child, BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB);

	tcp_init_buffer_space(child);



	tp->rcv_nxt = TCP_SKB_CB(skb)->seq + 1;

net/ipv4/tcp_input.c

+2 −1
Original line number Diff line number Diff line
@@ -5571,7 +5571,7 @@ void tcp_finish_connect(struct sock *sk, struct sk_buff *skb) 
	icsk->icsk_af_ops->rebuild_header(sk);



	tcp_init_metrics(sk);



	tcp_call_bpf(sk, BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB);

	tcp_init_congestion_control(sk);



	/* Prevent spurious tcp_cwnd_restart() on first data
@@ -5977,6 +5977,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) 
		} else {

			/* Make sure socket is routed, for correct metrics. */

			icsk->icsk_af_ops->rebuild_header(sk);

			tcp_call_bpf(sk, BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB);

			tcp_init_congestion_control(sk);



			tcp_mtup_init(sk);

net/ipv4/tcp_output.c

+1 −0
Original line number Diff line number Diff line
@@ -3444,6 +3444,7 @@ int tcp_connect(struct sock *sk) 
	struct sk_buff *buff;

	int err;



	tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_CONNECT_CB);

	tcp_connect_init(sk);



	if (unlikely(tp->repair)) {