From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lawrence Brakmo Subject: [PATCH bpf-next v6 09/11] bpf: Add BPF_SOCK_OPS_RETRANS_CB Date: Fri, 19 Jan 2018 17:45:46 -0800 Message-ID: <20180120014548.2941040-10-brakmo@fb.com> References: <20180120014548.2941040-1-brakmo@fb.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Kernel Team , Blake Matheny , Alexei Starovoitov , Daniel Borkmann , Eric Dumazet , Neal Cardwell , Yuchung Cheng To: netdev Return-path: Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:42156 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756487AbeATBp5 (ORCPT ); Fri, 19 Jan 2018 20:45:57 -0500 Received: from pps.filterd (m0109333.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w0K1jA9t002914 for ; Fri, 19 Jan 2018 17:45:57 -0800 Received: from mail.thefacebook.com ([199.201.64.23]) by mx0a-00082601.pphosted.com with ESMTP id 2fkum9g2rs-10 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT) for ; Fri, 19 Jan 2018 17:45:57 -0800 In-Reply-To: <20180120014548.2941040-1-brakmo@fb.com> Sender: netdev-owner@vger.kernel.org List-ID: Adds support for calling sock_ops BPF program when there is a retransmission. Two arguments are used; one for the sequence number and other for the number of segments retransmitted. Does not include syn-ack retransmissions. New op: BPF_SOCK_OPS_RETRANS_CB. Signed-off-by: Lawrence Brakmo --- include/uapi/linux/bpf.h | 4 ++++ include/uapi/linux/tcp.h | 3 ++- net/ipv4/tcp_output.c | 3 +++ 3 files changed, 9 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 1c80ff4..2f752f3 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1039,6 +1039,10 @@ enum { * Arg2: value of icsk_rto * Arg3: whether RTO has expired */ + BPF_SOCK_OPS_RETRANS_CB, /* Called when skb is retransmitted. + * Arg1: sequence number of 1st byte + * Arg2: # segments + */ }; #define TCP_BPF_IW 1001 /* Set TCP initial congestion window */ diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h index 129032ca..ec03a2b 100644 --- a/include/uapi/linux/tcp.h +++ b/include/uapi/linux/tcp.h @@ -270,7 +270,8 @@ struct tcp_diag_md5sig { /* Definitions for bpf_sock_ops_cb_flags */ #define BPF_SOCK_OPS_RTO_CB_FLAG (1<<0) -#define BPF_SOCK_OPS_ALL_CB_FLAGS 0x1 /* Mask of all currently +#define BPF_SOCK_OPS_RETRANS_CB_FLAG (1<<1) +#define BPF_SOCK_OPS_ALL_CB_FLAGS 0x3 /* Mask of all currently * supported cb flags */ diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index d12f7f7..f7d34f01 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2908,6 +2908,9 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs) if (likely(!err)) { TCP_SKB_CB(skb)->sacked |= TCPCB_EVER_RETRANS; trace_tcp_retransmit_skb(sk, skb); + if (BPF_SOCK_OPS_TEST_FLAG(tp, BPF_SOCK_OPS_RETRANS_CB_FLAG)) + tcp_call_bpf_2arg(sk, BPF_SOCK_OPS_RETRANS_CB, + TCP_SKB_CB(skb)->seq, segs); } else if (err != -EBUSY) { NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRETRANSFAIL); } -- 2.9.5