From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lawrence Brakmo Subject: [PATCH net-next v3 03/15] bpf: Support for per connection SYN/SYN-ACK RTOs Date: Mon, 19 Jun 2017 20:00:36 -0700 Message-ID: <20170620030048.3275347-4-brakmo@fb.com> References: <20170620030048.3275347-1-brakmo@fb.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Kernel Team , Blake Matheny , Alexei Starovoitov , Daniel Borkmann , David Ahern To: netdev Return-path: Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:51757 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751071AbdFTDAy (ORCPT ); Mon, 19 Jun 2017 23:00:54 -0400 Received: from pps.filterd (m0109331.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v5K2w3rF024384 for ; Mon, 19 Jun 2017 20:00:53 -0700 Received: from mail.thefacebook.com ([199.201.64.23]) by mx0a-00082601.pphosted.com with ESMTP id 2b6nvx8r6q-4 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT) for ; Mon, 19 Jun 2017 20:00:53 -0700 Received: from facebook.com (2401:db00:11:d025:face:0:13:0) by mx-out.facebook.com (2401:db00:2050:5102:face:0000:0037:0000) with ESMTP id aae460c2556411e79fcee32f9c16277d-aef368f0 for ; Mon, 19 Jun 2017 20:00:51 -0700 In-Reply-To: <20170620030048.3275347-1-brakmo@fb.com> Sender: netdev-owner@vger.kernel.org List-ID: This patch adds support for setting a per connection SYN and SYN_ACK RTOs from within a BPF_SOCK_OPS program. For example, to set small RTOs when it is known both hosts are within a datacenter. Signed-off-by: Lawrence Brakmo --- include/net/tcp.h | 11 +++++++++++ include/uapi/linux/bpf.h | 3 +++ net/ipv4/tcp_input.c | 3 ++- net/ipv4/tcp_output.c | 2 +- 4 files changed, 17 insertions(+), 2 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index f6f415c..bdf6bfd 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -2051,4 +2051,15 @@ static inline int tcp_call_bpf(struct sock *sk, bool is_req_sock, int op) } #endif +static inline u32 tcp_timeout_init(struct sock *sk, bool is_req_sock) +{ + int timeout; + + timeout = tcp_call_bpf(sk, is_req_sock, BPF_SOCK_OPS_TIMEOUT_INIT); + + if (timeout <= 0) + timeout = TCP_TIMEOUT_INIT; + return timeout; +} + #endif /* _TCP_H */ diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 861dbe9..4532c31 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -746,6 +746,9 @@ struct bpf_sock_ops { */ enum { BPF_SOCK_OPS_VOID, + BPF_SOCK_OPS_TIMEOUT_INIT, /* Should return SYN-RTO value to use or + * -1 if default value should be used + */ }; #endif /* _UAPI__LINUX_BPF_H__ */ diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 2ab7e2f..0867b05 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -6406,7 +6406,8 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, } else { tcp_rsk(req)->tfo_listener = false; if (!want_cookie) - inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT); + inet_csk_reqsk_queue_hash_add(sk, req, + tcp_timeout_init((struct sock *)req, true)); af_ops->send_synack(sk, dst, &fl, req, &foc, !want_cookie ? TCP_SYNACK_NORMAL : TCP_SYNACK_COOKIE); diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 9a9c395..5e478a1 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -3327,7 +3327,7 @@ static void tcp_connect_init(struct sock *sk) tp->rcv_wup = tp->rcv_nxt; tp->copied_seq = tp->rcv_nxt; - inet_csk(sk)->icsk_rto = TCP_TIMEOUT_INIT; + inet_csk(sk)->icsk_rto = tcp_timeout_init(sk, false); inet_csk(sk)->icsk_retransmits = 0; tcp_clear_retrans(tp); } -- 2.9.3