Commit 57bfc760 authored by Miao Xu's avatar Miao Xu Committed by Martin KaFai Lau
Browse files

tcp: Add new args for cong_control in tcp_congestion_ops 



This patch adds two new arguments for cong_control of struct
tcp_congestion_ops:
 - ack
 - flag
These two arguments are inherited from the caller tcp_cong_control in
tcp_intput.c. One use case of them is to update cwnd and pacing rate
inside cong_control based on the info they provide. For example, the
flag can be used to decide if it is the right time to raise or reduce a
sender's cwnd.

Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarMiao Xu <miaxu@meta.com>
Link: https://lore.kernel.org/r/20240502042318.801932-2-miaxu@meta.com


Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
parent f8c423d1

include/net/tcp.h

+1 −1
Original line number Diff line number Diff line
@@ -1172,7 +1172,7 @@ struct tcp_congestion_ops { 
	/* call when packets are delivered to update cwnd and pacing rate,

	 * after all the ca_state processing. (optional)

	 */

	void (*cong_control)(struct sock *sk, const struct rate_sample *rs);

	void (*cong_control)(struct sock *sk, u32 ack, int flag, const struct rate_sample *rs);





	/* new value of cwnd after loss (required) */

net/ipv4/bpf_tcp_ca.c

+2 −1
Original line number Diff line number Diff line
@@ -307,7 +307,8 @@ static u32 bpf_tcp_ca_min_tso_segs(struct sock *sk) 
	return 0;

}



static void bpf_tcp_ca_cong_control(struct sock *sk, const struct rate_sample *rs)

static void bpf_tcp_ca_cong_control(struct sock *sk, u32 ack, int flag,

				    const struct rate_sample *rs)

{

}

net/ipv4/tcp_bbr.c

+1 −1
Original line number Diff line number Diff line
@@ -1024,7 +1024,7 @@ static void bbr_update_model(struct sock *sk, const struct rate_sample *rs) 
	bbr_update_gains(sk);

}



__bpf_kfunc static void bbr_main(struct sock *sk, const struct rate_sample *rs)

__bpf_kfunc static void bbr_main(struct sock *sk, u32 ack, int flag, const struct rate_sample *rs)

{

	struct bbr *bbr = inet_csk_ca(sk);

	u32 bw;

net/ipv4/tcp_input.c

+1 −1
Original line number Diff line number Diff line
@@ -3541,7 +3541,7 @@ static void tcp_cong_control(struct sock *sk, u32 ack, u32 acked_sacked, 
	const struct inet_connection_sock *icsk = inet_csk(sk);



	if (icsk->icsk_ca_ops->cong_control) {

		icsk->icsk_ca_ops->cong_control(sk, rs);

		icsk->icsk_ca_ops->cong_control(sk, ack, flag, rs);

		return;

	}

tools/testing/selftests/bpf/progs/tcp_ca_kfunc.c

+3 −3
Original line number Diff line number Diff line
@@ -5,7 +5,7 @@ 
#include <bpf/bpf_tracing.h>



extern void bbr_init(struct sock *sk) __ksym;

extern void bbr_main(struct sock *sk, const struct rate_sample *rs) __ksym;

extern void bbr_main(struct sock *sk, u32 ack, int flag, const struct rate_sample *rs) __ksym;

extern u32 bbr_sndbuf_expand(struct sock *sk) __ksym;

extern u32 bbr_undo_cwnd(struct sock *sk) __ksym;

extern void bbr_cwnd_event(struct sock *sk, enum tcp_ca_event event) __ksym;
@@ -42,9 +42,9 @@ void BPF_PROG(in_ack_event, struct sock *sk, u32 flags) 
}



SEC("struct_ops/cong_control")

void BPF_PROG(cong_control, struct sock *sk, const struct rate_sample *rs)

void BPF_PROG(cong_control, struct sock *sk, u32 ack, int flag, const struct rate_sample *rs)

{

	bbr_main(sk, rs);

	bbr_main(sk, ack, flag, rs);

}



SEC("struct_ops/cong_avoid")