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From: Martin KaFai Lau <kafai@fb.com>
To: <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Eric Dumazet <edumazet@google.com>, <kernel-team@fb.com>,
	Lawrence Brakmo <brakmo@fb.com>,
	Neal Cardwell <ncardwell@google.com>, <netdev@vger.kernel.org>,
	Yuchung Cheng <ycheng@google.com>,
	John Fastabend <john.fastabend@gmail.com>
Subject: [PATCH v5 bpf-next 03/12] tcp: bpf: Add TCP_BPF_RTO_MIN for bpf_setsockopt
Date: Thu, 20 Aug 2020 12:00:27 -0700	[thread overview]
Message-ID: <20200820190027.2884170-1-kafai@fb.com> (raw)
In-Reply-To: <20200820190008.2883500-1-kafai@fb.com>

This patch adds bpf_setsockopt(TCP_BPF_RTO_MIN) to allow bpf prog
to set the min rto of a connection.  It could be used together
with the earlier patch which has added bpf_setsockopt(TCP_BPF_DELACK_MAX).

A later selftest patch will communicate the max delay ack in a
bpf tcp header option and then the receiving side can use
bpf_setsockopt(TCP_BPF_RTO_MIN) to set a shorter rto.

Acked-by: John Fastabend <john.fastabend@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
---
 include/net/inet_connection_sock.h | 1 +
 include/net/tcp.h                  | 2 +-
 include/uapi/linux/bpf.h           | 1 +
 net/core/filter.c                  | 7 +++++++
 net/ipv4/tcp.c                     | 2 ++
 tools/include/uapi/linux/bpf.h     | 1 +
 6 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h
index da7264a1ebfc..c738abeb3265 100644
--- a/include/net/inet_connection_sock.h
+++ b/include/net/inet_connection_sock.h
@@ -86,6 +86,7 @@ struct inet_connection_sock {
  	struct timer_list	  icsk_retransmit_timer;
  	struct timer_list	  icsk_delack_timer;
 	__u32			  icsk_rto;
+	__u32                     icsk_rto_min;
 	__u32                     icsk_delack_max;
 	__u32			  icsk_pmtu_cookie;
 	const struct tcp_congestion_ops *icsk_ca_ops;
diff --git a/include/net/tcp.h b/include/net/tcp.h
index eab6c7510b5b..dda778c782fe 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -699,7 +699,7 @@ static inline void tcp_fast_path_check(struct sock *sk)
 static inline u32 tcp_rto_min(struct sock *sk)
 {
 	const struct dst_entry *dst = __sk_dst_get(sk);
-	u32 rto_min = TCP_RTO_MIN;
+	u32 rto_min = inet_csk(sk)->icsk_rto_min;
 
 	if (dst && dst_metric_locked(dst, RTAX_RTO_MIN))
 		rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN);
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index f5d9549c52dc..4bd75c12476b 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -4251,6 +4251,7 @@ enum {
 	TCP_BPF_IW		= 1001,	/* Set TCP initial congestion window */
 	TCP_BPF_SNDCWND_CLAMP	= 1002,	/* Set sndcwnd_clamp */
 	TCP_BPF_DELACK_MAX	= 1003, /* Max delay ack in usecs */
+	TCP_BPF_RTO_MIN		= 1004, /* Min delay ack in usecs */
 };
 
 struct bpf_perf_event_value {
diff --git a/net/core/filter.c b/net/core/filter.c
index 80fe7420f609..075ab71b985c 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4488,6 +4488,13 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname,
 					return -EINVAL;
 				inet_csk(sk)->icsk_delack_max = timeout;
 				break;
+			case TCP_BPF_RTO_MIN:
+				timeout = usecs_to_jiffies(val);
+				if (timeout > TCP_RTO_MIN ||
+				    timeout < TCP_TIMEOUT_MIN)
+					return -EINVAL;
+				inet_csk(sk)->icsk_rto_min = timeout;
+				break;
 			case TCP_SAVE_SYN:
 				if (val < 0 || val > 1)
 					ret = -EINVAL;
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 44c353a39ad4..6075cb091a20 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -418,6 +418,7 @@ void tcp_init_sock(struct sock *sk)
 	INIT_LIST_HEAD(&tp->tsorted_sent_queue);
 
 	icsk->icsk_rto = TCP_TIMEOUT_INIT;
+	icsk->icsk_rto_min = TCP_RTO_MIN;
 	icsk->icsk_delack_max = TCP_DELACK_MAX;
 	tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT);
 	minmax_reset(&tp->rtt_min, tcp_jiffies32, ~0U);
@@ -2686,6 +2687,7 @@ int tcp_disconnect(struct sock *sk, int flags)
 	icsk->icsk_backoff = 0;
 	icsk->icsk_probes_out = 0;
 	icsk->icsk_rto = TCP_TIMEOUT_INIT;
+	icsk->icsk_rto_min = TCP_RTO_MIN;
 	icsk->icsk_delack_max = TCP_DELACK_MAX;
 	tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
 	tp->snd_cwnd = TCP_INIT_CWND;
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index f5d9549c52dc..4bd75c12476b 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -4251,6 +4251,7 @@ enum {
 	TCP_BPF_IW		= 1001,	/* Set TCP initial congestion window */
 	TCP_BPF_SNDCWND_CLAMP	= 1002,	/* Set sndcwnd_clamp */
 	TCP_BPF_DELACK_MAX	= 1003, /* Max delay ack in usecs */
+	TCP_BPF_RTO_MIN		= 1004, /* Min delay ack in usecs */
 };
 
 struct bpf_perf_event_value {
-- 
2.24.1


  parent reply	other threads:[~2020-08-20 19:00 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-20 19:00 [PATCH v5 bpf-next 00/12] BPF TCP header options Martin KaFai Lau
2020-08-20 19:00 ` [PATCH v5 bpf-next 01/12] tcp: Use a struct to represent a saved_syn Martin KaFai Lau
2020-08-20 19:00 ` [PATCH v5 bpf-next 02/12] tcp: bpf: Add TCP_BPF_DELACK_MAX setsockopt Martin KaFai Lau
2020-08-20 19:00 ` Martin KaFai Lau [this message]
2020-08-20 19:00 ` [PATCH v5 bpf-next 04/12] tcp: Add saw_unknown to struct tcp_options_received Martin KaFai Lau
2020-08-20 19:00 ` [PATCH v5 bpf-next 05/12] bpf: tcp: Add bpf_skops_established() Martin KaFai Lau
2020-08-20 19:00 ` [PATCH v5 bpf-next 06/12] bpf: tcp: Add bpf_skops_parse_hdr() Martin KaFai Lau
2020-08-20 19:00 ` [PATCH v5 bpf-next 07/12] bpf: tcp: Add bpf_skops_hdr_opt_len() and bpf_skops_write_hdr_opt() Martin KaFai Lau
2020-08-20 22:39   ` Mat Martineau
2020-08-20 22:54     ` Eric Dumazet
2020-08-20 23:16     ` Martin KaFai Lau
2020-08-20 19:00 ` [PATCH v5 bpf-next 08/12] bpf: sock_ops: Change some members of sock_ops_kern from u32 to u8 Martin KaFai Lau
2020-08-20 19:01 ` [PATCH v5 bpf-next 09/12] bpf: tcp: Allow bpf prog to write and parse TCP header option Martin KaFai Lau
2020-09-30 15:23   ` sdf
2020-10-01 22:38     ` Martin KaFai Lau
2020-08-20 19:01 ` [PATCH v5 bpf-next 10/12] bpf: selftests: Add fastopen_connect to network_helpers Martin KaFai Lau
2020-08-20 19:01 ` [PATCH v5 bpf-next 11/12] bpf: selftests: tcp header options Martin KaFai Lau
2020-08-20 19:01 ` [PATCH v5 bpf-next 12/12] tcp: bpf: Optionally store mac header in TCP_SAVE_SYN Martin KaFai Lau
2020-08-24 21:43 ` [PATCH v5 bpf-next 00/12] BPF TCP header options Alexei Starovoitov

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