From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lawrence Brakmo Subject: [PATCH bpf 05/11] bpf: Adds field bpf_sock_ops_flags to tcp_sock Date: Mon, 18 Dec 2017 22:21:54 -0800 Message-ID: <20171219062200.372711-6-brakmo@fb.com> References: <20171219062200.372711-1-brakmo@fb.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Kernel Team , Blake Matheny , "Alexei Starovoitov" , Daniel Borkmann To: netdev Return-path: Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:34474 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761364AbdLSGW2 (ORCPT ); Tue, 19 Dec 2017 01:22:28 -0500 Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id vBJ6KqhZ030090 for ; Mon, 18 Dec 2017 22:22:27 -0800 Received: from mail.thefacebook.com ([199.201.64.23]) by mx0a-00082601.pphosted.com with ESMTP id 2exwdnr04c-1 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT) for ; Mon, 18 Dec 2017 22:22:27 -0800 In-Reply-To: <20171219062200.372711-1-brakmo@fb.com> Sender: netdev-owner@vger.kernel.org List-ID: Adds field bpf_sock_ops_flags to tcp_sock and bpf_sock_ops. Its primary use is to determine if there should be calls to sock_ops bpf program at various points in the TCP code. The field is initialized to zero, disabling the calls. A sock_ops BPF program can set, per connection and as necessary, when the connection is established. It also adds support for reading and writting the field within a sock_ops BPF program. Examples of where to call the bpf program: 1) When RTO fires 2) When a packet is retransmitted 3) When the connection terminates 4) When a packet is sent 5) When a packet is received Signed-off-by: Lawrence Brakmo --- include/linux/tcp.h | 8 ++++++++ include/uapi/linux/bpf.h | 1 + net/core/filter.c | 6 ++++++ 3 files changed, 15 insertions(+) diff --git a/include/linux/tcp.h b/include/linux/tcp.h index df5d97a..c46553f 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -372,6 +372,14 @@ struct tcp_sock { */ struct request_sock *fastopen_rsk; u32 *saved_syn; + +/* Sock_ops bpf program related variables */ +#ifdef CONFIG_BPF + u32 bpf_sock_ops_flags; /* values defined in uapi/linux/tcp.h */ +#define BPF_SOCK_OPS_TEST_FLAG(TP, ARG) (TP->bpf_sock_ops_flags & ARG) +#else +#define BPF_SOCK_OPS_TEST_FLAG(TP, ARG) 0 +#endif }; enum tsq_enum { diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index addd849..dfbf43a 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -953,6 +953,7 @@ struct bpf_sock_ops { */ __u32 snd_cwnd; __u32 srtt_us; /* Averaged RTT << 3 in usecs */ + __u32 bpf_sock_ops_flags; /* flags defined in uapi/linux/tcp.h */ }; /* List of known BPF sock_ops operators. diff --git a/net/core/filter.c b/net/core/filter.c index 97e65df..2692514 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3842,6 +3842,7 @@ static bool sock_ops_is_valid_access(int off, int size, switch (off) { case offsetof(struct bpf_sock_ops, op) ... offsetof(struct bpf_sock_ops, replylong[3]): + case offsetof(struct bpf_sock_ops, bpf_sock_ops_flags): break; default: return false; @@ -4522,6 +4523,11 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type, case offsetof(struct bpf_sock_ops, srtt_us): SOCK_OPS_GET_FIELD(srtt_us, struct tcp_sock); break; + + case offsetof(struct bpf_sock_ops, bpf_sock_ops_flags): + SOCK_OPS_GET_OR_SET_FIELD(bpf_sock_ops_flags, struct tcp_sock, + type); + break; } return insn - insn_buf; } -- 2.9.5