From patchwork Mon Aug 3 23:11:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin KaFai Lau X-Patchwork-Id: 1340607 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=fb.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=fb.com header.i=@fb.com header.a=rsa-sha256 header.s=facebook header.b=Lz5sfVaS; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BLDCt1NxMz9sR4 for ; Tue, 4 Aug 2020 09:11:38 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729230AbgHCXLh (ORCPT ); Mon, 3 Aug 2020 19:11:37 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:5996 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729226AbgHCXLh (ORCPT ); Mon, 3 Aug 2020 19:11:37 -0400 Received: from pps.filterd (m0089730.ppops.net [127.0.0.1]) by m0089730.ppops.net (8.16.0.42/8.16.0.42) with SMTP id 073MtAao013131 for ; Mon, 3 Aug 2020 16:11:35 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=+IEUf0xZ8dTX/kRSFz42cb/OMoa7ChR09r+jtEdi8nA=; b=Lz5sfVaSKYzdB/ejJxFoONkBUQEB4X9m8Q0niNpZn0+/ybeRnypu88pGn034/GP4UcLO cPWzMSPRmlhtZlr9yRGDPfiRwkr4G5NS0REShMfjPa2OLwfkZeqKr8k2kkfR7zjMltBk ll3YV1toBe+Ai9qs6i34WqSPgjWIiUXbtO8= Received: from maileast.thefacebook.com ([163.114.130.16]) by m0089730.ppops.net with ESMTP id 32n81y9jnq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 03 Aug 2020 16:11:35 -0700 Received: from intmgw005.03.ash8.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::d) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Mon, 3 Aug 2020 16:11:35 -0700 Received: by devbig005.ftw2.facebook.com (Postfix, from userid 6611) id E01622943872; Mon, 3 Aug 2020 16:11:29 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Martin KaFai Lau Smtp-Origin-Hostname: devbig005.ftw2.facebook.com To: CC: Alexei Starovoitov , Daniel Borkmann , Eric Dumazet , , Lawrence Brakmo , Neal Cardwell , , Yuchung Cheng Smtp-Origin-Cluster: ftw2c04 Subject: [RFC PATCH v4 bpf-next 12/12] tcp: bpf: Optionally store mac header in TCP_SAVE_SYN Date: Mon, 3 Aug 2020 16:11:29 -0700 Message-ID: <20200803231129.2687001-1-kafai@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200803231013.2681560-1-kafai@fb.com> References: <20200803231013.2681560-1-kafai@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-08-03_15:2020-08-03,2020-08-03 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 malwarescore=0 phishscore=0 priorityscore=1501 mlxlogscore=998 bulkscore=0 suspectscore=3 impostorscore=0 adultscore=0 clxscore=1015 mlxscore=0 spamscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2008030158 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org This patch is adapted from Eric's patch in an earlier discussion [1]. The TCP_SAVE_SYN currently only stores the network header and tcp header. This patch allows it to optionally store the mac header also if the setsockopt's optval is 2. It requires one more bit for the "save_syn" bit field in tcp_sock. This patch achieves this by moving the syn_smc bit next to the is_mptcp. The syn_smc is currently used with the TCP experimental option. Since syn_smc is only used when CONFIG_SMC is enabled, this patch also puts the "IS_ENABLED(CONFIG_SMC)" around it like the is_mptcp did with "IS_ENABLED(CONFIG_MPTCP)". The mac_hdrlen is also stored in the "struct saved_syn" to allow a quick offset from the bpf prog if it chooses to start getting from the network header or the tcp header. [1]: https://lore.kernel.org/netdev/CANn89iLJNWh6bkH7DNhy_kmcAexuUCccqERqe7z2QsvPhGrYPQ@mail.gmail.com/ Suggested-by: Eric Dumazet Reviewed-by: Eric Dumazet Signed-off-by: Martin KaFai Lau --- include/linux/tcp.h | 13 ++++++++----- include/net/request_sock.h | 1 + include/uapi/linux/bpf.h | 1 + net/core/filter.c | 27 ++++++++++++++++++++++----- net/ipv4/tcp.c | 3 ++- net/ipv4/tcp_input.c | 14 +++++++++++++- tools/include/uapi/linux/bpf.h | 1 + 7 files changed, 48 insertions(+), 12 deletions(-) diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 981145691f60..97cfb33305c0 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -239,14 +239,13 @@ struct tcp_sock { repair : 1, frto : 1;/* F-RTO (RFC5682) activated in CA_Loss */ u8 repair_queue; - u8 syn_data:1, /* SYN includes data */ + u8 save_syn:2, /* Save headers of SYN packet */ + syn_data:1, /* SYN includes data */ syn_fastopen:1, /* SYN includes Fast Open option */ syn_fastopen_exp:1,/* SYN includes Fast Open exp. option */ syn_fastopen_ch:1, /* Active TFO re-enabling probe */ syn_data_acked:1,/* data in SYN is acked by SYN-ACK */ - save_syn:1, /* Save headers of SYN packet */ - is_cwnd_limited:1,/* forward progress limited by snd_cwnd? */ - syn_smc:1; /* SYN includes SMC */ + is_cwnd_limited:1;/* forward progress limited by snd_cwnd? */ u32 tlp_high_seq; /* snd_nxt at the time of TLP */ u32 tcp_tx_delay; /* delay (in usec) added to TX packets */ @@ -393,6 +392,9 @@ struct tcp_sock { #if IS_ENABLED(CONFIG_MPTCP) bool is_mptcp; #endif +#if IS_ENABLED(CONFIG_SMC) + bool syn_smc; /* SYN includes SMC */ +#endif #ifdef CONFIG_TCP_MD5SIG /* TCP AF-Specific parts; only used by MD5 Signature support so far */ @@ -488,7 +490,8 @@ static inline void tcp_saved_syn_free(struct tcp_sock *tp) static inline u32 tcp_saved_syn_len(const struct saved_syn *saved_syn) { - return saved_syn->network_hdrlen + saved_syn->tcp_hdrlen; + return saved_syn->mac_hdrlen + saved_syn->network_hdrlen + + saved_syn->tcp_hdrlen; } struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk); diff --git a/include/net/request_sock.h b/include/net/request_sock.h index b1b101814ecb..8c99af5ea891 100644 --- a/include/net/request_sock.h +++ b/include/net/request_sock.h @@ -42,6 +42,7 @@ struct request_sock_ops { int inet_rtx_syn_ack(const struct sock *parent, struct request_sock *req); struct saved_syn { + u32 mac_hdrlen; u32 network_hdrlen; u32 tcp_hdrlen; u8 data[]; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index c6162ee573e9..68e71c948dc3 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -4455,6 +4455,7 @@ enum { */ TCP_BPF_SYN = 1005, /* Copy the TCP header */ TCP_BPF_SYN_IP = 1006, /* Copy the IP[46] and TCP header */ + TCP_BPF_SYN_MAC = 1007, /* Copy the MAC, IP[46], and TCP header */ }; enum { diff --git a/net/core/filter.c b/net/core/filter.c index 607f87901122..477192550838 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4682,11 +4682,16 @@ static int bpf_sock_ops_get_syn(struct bpf_sock_ops_kern *bpf_sock, if (optname == TCP_BPF_SYN) { hdr_start = syn_skb->data; ret = tcp_hdrlen(syn_skb); - } else { - /* optname == TCP_BPF_SYN_IP */ + } else if (optname == TCP_BPF_SYN_IP) { hdr_start = skb_network_header(syn_skb); ret = skb_network_header_len(syn_skb) + tcp_hdrlen(syn_skb); + } else { + /* optname == TCP_BPF_SYN_MAC */ + hdr_start = skb_mac_header(syn_skb); + ret = skb_mac_header_len(syn_skb) + + skb_network_header_len(syn_skb) + + tcp_hdrlen(syn_skb); } } else { struct sock *sk = bpf_sock->sk; @@ -4706,12 +4711,24 @@ static int bpf_sock_ops_get_syn(struct bpf_sock_ops_kern *bpf_sock, if (optname == TCP_BPF_SYN) { hdr_start = saved_syn->data + + saved_syn->mac_hdrlen + saved_syn->network_hdrlen; ret = saved_syn->tcp_hdrlen; + } else if (optname == TCP_BPF_SYN_IP) { + hdr_start = saved_syn->data + + saved_syn->mac_hdrlen; + ret = saved_syn->network_hdrlen + + saved_syn->tcp_hdrlen; } else { - /* optname == TCP_BPF_SYN_IP */ + /* optname == TCP_BPF_SYN_MAC */ + + /* TCP_SAVE_SYN may not have saved the mac hdr */ + if (!saved_syn->mac_hdrlen) + return -ENOENT; + hdr_start = saved_syn->data; - ret = saved_syn->network_hdrlen + + ret = saved_syn->mac_hdrlen + + saved_syn->network_hdrlen + saved_syn->tcp_hdrlen; } } @@ -4724,7 +4741,7 @@ BPF_CALL_5(bpf_sock_ops_getsockopt, struct bpf_sock_ops_kern *, bpf_sock, int, level, int, optname, char *, optval, int, optlen) { if (IS_ENABLED(CONFIG_INET) && level == SOL_TCP && - optname >= TCP_BPF_SYN && optname <= TCP_BPF_SYN_IP) { + optname >= TCP_BPF_SYN && optname <= TCP_BPF_SYN_MAC) { int ret, copy_len = 0; const u8 *start; diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 98606f94b01b..b3d275624658 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3210,7 +3210,8 @@ static int do_tcp_setsockopt(struct sock *sk, int level, int optname, break; case TCP_SAVE_SYN: - if (val < 0 || val > 1) + /* 0: disable, 1: enable, 2: start from ether_header */ + if (val < 0 || val > 2) err = -EINVAL; else tp->save_syn = val; diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 40ffdfc9adf4..af235b058d14 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -6675,13 +6675,25 @@ static void tcp_reqsk_record_syn(const struct sock *sk, if (tcp_sk(sk)->save_syn) { u32 len = skb_network_header_len(skb) + tcp_hdrlen(skb); struct saved_syn *saved_syn; + u32 mac_hdrlen; + void *base; + + if (tcp_sk(sk)->save_syn == 2) { /* Save full header. */ + base = skb_mac_header(skb); + mac_hdrlen = skb_mac_header_len(skb); + len += mac_hdrlen; + } else { + base = skb_network_header(skb); + mac_hdrlen = 0; + } saved_syn = kmalloc(struct_size(saved_syn, data, len), GFP_ATOMIC); if (saved_syn) { + saved_syn->mac_hdrlen = mac_hdrlen; saved_syn->network_hdrlen = skb_network_header_len(skb); saved_syn->tcp_hdrlen = tcp_hdrlen(skb); - memcpy(saved_syn->data, skb_network_header(skb), len); + memcpy(saved_syn->data, base, len); req->saved_syn = saved_syn; } } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index c6162ee573e9..68e71c948dc3 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -4455,6 +4455,7 @@ enum { */ TCP_BPF_SYN = 1005, /* Copy the TCP header */ TCP_BPF_SYN_IP = 1006, /* Copy the IP[46] and TCP header */ + TCP_BPF_SYN_MAC = 1007, /* Copy the MAC, IP[46], and TCP header */ }; enum {