Commit 87637398 authored by Martin KaFai Lau's avatar Martin KaFai Lau
Browse files

Merge branch 'bpf: add mrtt and srtt as ctx->args for BPF_SOCK_OPS_RTT_CB' 



Philo Lu says:

====================
These provides more information about tcp RTT estimation. The selftest for
BPF_SOCK_OPS_RTT_CB is extended for the added args.

changelogs
-> v1:
- extend rtt selftest for added args (suggested by Stanislav)
====================

Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
parents a311c3f9 7eb4f66b

include/net/tcp.h

+2 −2
Original line number Diff line number Diff line
@@ -2706,10 +2706,10 @@ static inline bool tcp_bpf_ca_needs_ecn(struct sock *sk) 
	return (tcp_call_bpf(sk, BPF_SOCK_OPS_NEEDS_ECN, 0, NULL) == 1);

}



static inline void tcp_bpf_rtt(struct sock *sk)

static inline void tcp_bpf_rtt(struct sock *sk, long mrtt, u32 srtt)

{

	if (BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), BPF_SOCK_OPS_RTT_CB_FLAG))

		tcp_call_bpf(sk, BPF_SOCK_OPS_RTT_CB, 0, NULL);

		tcp_call_bpf_2arg(sk, BPF_SOCK_OPS_RTT_CB, mrtt, srtt);

}



#if IS_ENABLED(CONFIG_SMC)

include/uapi/linux/bpf.h

+2 −0
Original line number Diff line number Diff line
@@ -6947,6 +6947,8 @@ enum { 
					 * socket transition to LISTEN state.

					 */

	BPF_SOCK_OPS_RTT_CB,		/* Called on every RTT.

					 * Arg1: measured RTT input (mrtt)

					 * Arg2: updated srtt

					 */

	BPF_SOCK_OPS_PARSE_HDR_OPT_CB,	/* Parse the header option.

					 * It will be called to handle

net/ipv4/tcp_input.c

+2 −2
Original line number Diff line number Diff line
@@ -911,7 +911,7 @@ static void tcp_rtt_estimator(struct sock *sk, long mrtt_us) 
			tp->rtt_seq = tp->snd_nxt;

			tp->mdev_max_us = tcp_rto_min_us(sk);



			tcp_bpf_rtt(sk);

			tcp_bpf_rtt(sk, mrtt_us, srtt);

		}

	} else {

		/* no previous measure. */
@@ -921,7 +921,7 @@ static void tcp_rtt_estimator(struct sock *sk, long mrtt_us) 
		tp->mdev_max_us = tp->rttvar_us;

		tp->rtt_seq = tp->snd_nxt;



		tcp_bpf_rtt(sk);

		tcp_bpf_rtt(sk, mrtt_us, srtt);

	}

	tp->srtt_us = max(1U, srtt);

}

tools/include/uapi/linux/bpf.h

+2 −0
Original line number Diff line number Diff line
@@ -6947,6 +6947,8 @@ enum { 
					 * socket transition to LISTEN state.

					 */

	BPF_SOCK_OPS_RTT_CB,		/* Called on every RTT.

					 * Arg1: measured RTT input (mrtt)

					 * Arg2: updated srtt

					 */

	BPF_SOCK_OPS_PARSE_HDR_OPT_CB,	/* Parse the header option.

					 * It will be called to handle

tools/testing/selftests/bpf/prog_tests/tcp_rtt.c

+14 −0
Original line number Diff line number Diff line
@@ -10,6 +10,9 @@ struct tcp_rtt_storage { 
	__u32 delivered;

	__u32 delivered_ce;

	__u32 icsk_retransmits;



	__u32 mrtt_us;	/* args[0] */

	__u32 srtt;	/* args[1] */

};



static void send_byte(int fd)
@@ -83,6 +86,17 @@ static int verify_sk(int map_fd, int client_fd, const char *msg, __u32 invoked, 
		err++;

	}



	/* Precise values of mrtt and srtt are unavailable, just make sure they are nonzero */

	if (val.mrtt_us == 0) {

		log_err("%s: unexpected bpf_tcp_sock.args[0] (mrtt_us) %u == 0", msg, val.mrtt_us);

		err++;

	}



	if (val.srtt == 0) {

		log_err("%s: unexpected bpf_tcp_sock.args[1] (srtt) %u == 0", msg, val.srtt);

		err++;

	}



	return err;

}