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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>
Subject: [PATCH bpf-next 09/10] tcp: bpf: Add TCP_BPF_DELACK_MAX and TCP_BPF_RTO_MIN to bpf_setsockopt
Date: Fri, 26 Jun 2020 10:55:58 -0700	[thread overview]
Message-ID: <20200626175558.1462731-1-kafai@fb.com> (raw)
In-Reply-To: <20200626175501.1459961-1-kafai@fb.com>

This change is mostly from an internal patch and adapts it from sysctl
config to the bpf_setsockopt setup.

The bpf_prog can set the max delay ack by using
bpf_setsockopt(TCP_BPF_DELACK_MAX).  This max delay ack can be communicated
to its peer through bpf header option.  The receiving peer can then use
this max delay ack and set a potentially lower rto by using
bpf_setsockopt(TCP_BPF_RTO_MIN).  A latter patch will use it
like this in a test as an example.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
---
 include/net/inet_connection_sock.h |  2 ++
 include/net/tcp.h                  |  2 +-
 include/uapi/linux/bpf.h           |  2 ++
 net/core/filter.c                  | 15 +++++++++++++++
 net/ipv4/tcp.c                     |  4 ++++
 net/ipv4/tcp_output.c              |  2 ++
 tools/include/uapi/linux/bpf.h     |  2 ++
 7 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h
index e5b388f5fa20..43d45864e5f0 100644
--- a/include/net/inet_connection_sock.h
+++ b/include/net/inet_connection_sock.h
@@ -93,6 +93,8 @@ 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;
 	const struct inet_connection_sock_af_ops *icsk_af_ops;
diff --git a/include/net/tcp.h b/include/net/tcp.h
index e93ef2d324f3..8a682d678971 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -703,7 +703,7 @@ 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 479b83d05811..2ccc81548eef 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -4299,6 +4299,8 @@ enum {
 	 *	    is not saved by TCP_SAVE_SYN.
 	 */
 	TCP_BPF_SYN_HDR_OPT	= 1003,
+	TCP_BPF_DELACK_MAX	= 1004, /* Max delay ack in usecs */
+	TCP_BPF_RTO_MIN		= 1005, /* Min delay ack in usecs */
 };
 
 struct bpf_perf_event_value {
diff --git a/net/core/filter.c b/net/core/filter.c
index 5784f1bede2f..4b80934e6876 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4431,6 +4431,7 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname,
 		} else {
 			struct inet_connection_sock *icsk = inet_csk(sk);
 			struct tcp_sock *tp = tcp_sk(sk);
+			unsigned long timeout;
 
 			if (optlen != sizeof(int))
 				return -EINVAL;
@@ -4452,6 +4453,20 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname,
 					tp->snd_ssthresh = val;
 				}
 				break;
+			case TCP_BPF_DELACK_MAX:
+				timeout = usecs_to_jiffies(val);
+				if (timeout > TCP_DELACK_MAX ||
+				    timeout < TCP_TIMEOUT_MIN)
+					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 60093a211f4d..02be3e2a2fdb 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -418,6 +418,8 @@ 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);
 
@@ -2685,6 +2687,8 @@ 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;
 	tp->snd_cwnd_cnt = 0;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index a78a29980e1f..db872a2a01c6 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3899,6 +3899,8 @@ void tcp_send_delayed_ack(struct sock *sk)
 		ato = min(ato, max_ato);
 	}
 
+	ato = min_t(u32, ato, inet_csk(sk)->icsk_delack_max);
+
 	/* Stay within the limit we were given */
 	timeout = jiffies + ato;
 
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 479b83d05811..2ccc81548eef 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -4299,6 +4299,8 @@ enum {
 	 *	    is not saved by TCP_SAVE_SYN.
 	 */
 	TCP_BPF_SYN_HDR_OPT	= 1003,
+	TCP_BPF_DELACK_MAX	= 1004, /* Max delay ack in usecs */
+	TCP_BPF_RTO_MIN		= 1005, /* Min delay ack in usecs */
 };
 
 struct bpf_perf_event_value {
-- 
2.24.1


  parent reply	other threads:[~2020-06-26 17:56 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-26 17:55 [PATCH bpf-next 00/10] BPF TCP header options Martin KaFai Lau
2020-06-26 17:55 ` [PATCH bpf-next 01/10] tcp: Use a struct to represent a saved_syn Martin KaFai Lau
2020-06-27 17:41   ` Eric Dumazet
2020-06-30 23:24     ` Martin KaFai Lau
2020-06-30 23:35       ` Eric Dumazet
2020-06-26 17:55 ` [PATCH bpf-next 02/10] tcp: bpf: Parse BPF experimental header option Martin KaFai Lau
2020-06-27 16:44   ` Eric Dumazet
2020-06-27 17:17   ` Eric Dumazet
2020-06-28 23:44     ` Martin KaFai Lau
2020-06-29  0:45     ` Martin KaFai Lau
2020-06-26 17:55 ` [PATCH bpf-next 03/10] bpf: sock_ops: Change some members of sock_ops_kern from u32 to u8 Martin KaFai Lau
2020-06-26 17:55 ` [PATCH bpf-next 04/10] bpf: tcp: Allow bpf prog to write and parse BPF TCP header option Martin KaFai Lau
2020-06-28 18:24   ` Alexei Starovoitov
2020-06-29  0:34     ` Martin KaFai Lau
2020-07-02  5:31       ` Martin KaFai Lau
2020-06-26 17:55 ` [PATCH bpf-next 05/10] bpf: selftests: A few improvements to network_helpers.c Martin KaFai Lau
2020-06-26 17:55 ` [PATCH bpf-next 06/10] bpf: selftests: Add fastopen_connect to network_helpers Martin KaFai Lau
2020-06-26 17:55 ` [PATCH bpf-next 07/10] bpf: selftests: Restore netns after each test Martin KaFai Lau
2020-06-26 22:45   ` Andrii Nakryiko
2020-06-27  0:23     ` Martin KaFai Lau
2020-06-27 20:31       ` Andrii Nakryiko
2020-06-29 18:00         ` Martin KaFai Lau
2020-06-29 18:13           ` Andrii Nakryiko
2020-06-29 18:24             ` Martin KaFai Lau
2020-06-26 17:55 ` [PATCH bpf-next 08/10] bpf: selftests: tcp header options Martin KaFai Lau
2020-06-26 17:55 ` Martin KaFai Lau [this message]
2020-06-27 17:30   ` [PATCH bpf-next 09/10] tcp: bpf: Add TCP_BPF_DELACK_MAX and TCP_BPF_RTO_MIN to bpf_setsockopt Eric Dumazet
2020-06-26 17:56 ` [PATCH bpf-next 10/10] bpf: selftest: Add test for TCP_BPF_DELACK_MAX and TCP_BPF_RTO_MIN Martin KaFai Lau

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