From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2D1B7C282C2 for ; Wed, 13 Feb 2019 19:53:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 01607222CF for ; Wed, 13 Feb 2019 19:53:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="HmJgE4g0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2436565AbfBMTxx (ORCPT ); Wed, 13 Feb 2019 14:53:53 -0500 Received: from mail-yw1-f74.google.com ([209.85.161.74]:49823 "EHLO mail-yw1-f74.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726291AbfBMTxw (ORCPT ); Wed, 13 Feb 2019 14:53:52 -0500 Received: by mail-yw1-f74.google.com with SMTP id r187so2113837ywb.16 for ; Wed, 13 Feb 2019 11:53:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=qqz5RegrCN8L1NVjilJsx8Ak84pUlSYYkGI27Z9WhK8=; b=HmJgE4g0VNji+mAbPsLbZz9pIr4ppDVdgopGGBxRZ+q/wcswfDxAYLBJdvTAVX9gEw beGKCg22gJ/lmXfIJzGhJDMy+oWL6g2wFraiHjBYxVe9+5xkDXpl8yJAHge7FjvqN5B9 xtFEf0hI3B4h/M4SzrsnJJKz3QmNl4UE8bwkJgYL1efs4c96oHTX7CROBcYaf1yivLCH +7earwCv/lTawYGx9JWuSEizmPGOum0Rj6qTgtdLI2V8IatfvPvJ+C5r3KCfsm0gVSsB TFBMReyE3yyYbhsMHyytoQlvQXz+TdIBKhQsTtnKnjTDZb6DFzNIbXLgpzmwQ3vcctTl QSOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=qqz5RegrCN8L1NVjilJsx8Ak84pUlSYYkGI27Z9WhK8=; b=CxmhnvNgTXofXMdzoFp+5JwBARf0kwl2QOTo74r4nYOYqGqjp9Hx7bfnYWW7PqD7jH SXybZlaLSGvC6aBXJ1Vkks1FYV5wRW7q9OAwP4LB+haUG6vIiRtsCL/gfxjvuGqGbt37 k5o7n6SX6MWOIZBF4rwnXpM48qt33TFXkY075pwpPCaJtJO9IGdPRg7DEtQZIJnoS19c VoLayfJmN34DaD8OtEArl6gUfutwClbFAOWTT5DzHWUNrjKVZLQH3pJszeKz8CPltQbi dHxDWuBShyLnSqADkxgQtXvtz3xOoWvcEQvsmSUETN3SZhCpDs70JdWYaESjVD+MQsUs eJ8A== X-Gm-Message-State: AHQUAubYwoKSPlyX7Klfz0/C4X9uxgN3LARFLwnxxQAkSyGAy7XiyVJM bXDJn9g+LyQ9WSrTYz+yKJZKiqAf X-Google-Smtp-Source: AHgI3IZ2RQnBMHmG8AQRhW57bRje87IZweqIVo9zg4bDBqHV7EuMEQHMX4Ip6/cQl3VxWlnDv0wn8u8s X-Received: by 2002:a5b:c82:: with SMTP id i2mr998236ybq.25.1550087631266; Wed, 13 Feb 2019 11:53:51 -0800 (PST) Date: Wed, 13 Feb 2019 11:53:36 -0800 In-Reply-To: <20190213195341.184969-1-posk@google.com> Message-Id: <20190213195341.184969-3-posk@google.com> Mime-Version: 1.0 References: <20190213195341.184969-1-posk@google.com> X-Mailer: git-send-email 2.20.1.791.gb4d0f1c61a-goog Subject: [PATCH bpf-next v11 2/7] bpf: implement BPF_LWT_ENCAP_IP mode in bpf_lwt_push_encap From: Peter Oskolkov To: Alexei Starovoitov , Daniel Borkmann , netdev@vger.kernel.org Cc: Peter Oskolkov , David Ahern , Willem de Bruijn , Peter Oskolkov Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Implement BPF_LWT_ENCAP_IP mode in bpf_lwt_push_encap BPF helper. It enables BPF programs (specifically, BPF_PROG_TYPE_LWT_IN and BPF_PROG_TYPE_LWT_XMIT prog types) to add IP encapsulation headers to packets (e.g. IP/GRE, GUE, IPIP). This is useful when thousands of different short-lived flows should be encapped, each with different and dynamically determined destination. Although lwtunnels can be used in some of these scenarios, the ability to dynamically generate encap headers adds more flexibility, e.g. when routing depends on the state of the host (reflected in global bpf maps). v7 changes: - added a call skb_clear_hash(); - removed calls to skb_set_transport_header(); - refuse to encap GSO-enabled packets. v8 changes: - fix build errors when LWT is not enabled. Note: the next patch in the patchset with deal with GSO-enabled packets, which are currently rejected at encapping attempt. Signed-off-by: Peter Oskolkov --- include/net/lwtunnel.h | 2 ++ net/core/filter.c | 3 +- net/core/lwt_bpf.c | 65 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 69 insertions(+), 1 deletion(-) diff --git a/include/net/lwtunnel.h b/include/net/lwtunnel.h index 33fd9ba7e0e5..671113bcb2cc 100644 --- a/include/net/lwtunnel.h +++ b/include/net/lwtunnel.h @@ -126,6 +126,8 @@ int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b); int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb); int lwtunnel_input(struct sk_buff *skb); int lwtunnel_xmit(struct sk_buff *skb); +int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len, + bool ingress); static inline void lwtunnel_set_redirect(struct dst_entry *dst) { diff --git a/net/core/filter.c b/net/core/filter.c index 12c88c21b6b8..a78deb2656e1 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -73,6 +73,7 @@ #include #include #include +#include /** * sk_filter_trim_cap - run a packet through a socket filter @@ -4819,7 +4820,7 @@ static int bpf_push_seg6_encap(struct sk_buff *skb, u32 type, void *hdr, u32 len static int bpf_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len, bool ingress) { - return -EINVAL; /* Implemented in the next patch. */ + return bpf_lwt_push_ip_encap(skb, hdr, len, ingress); } #endif diff --git a/net/core/lwt_bpf.c b/net/core/lwt_bpf.c index a648568c5e8f..e5a9850d9f48 100644 --- a/net/core/lwt_bpf.c +++ b/net/core/lwt_bpf.c @@ -390,6 +390,71 @@ static const struct lwtunnel_encap_ops bpf_encap_ops = { .owner = THIS_MODULE, }; +static int handle_gso_encap(struct sk_buff *skb, bool ipv4, int encap_len) +{ + /* Handling of GSO-enabled packets is added in the next patch. */ + return -EOPNOTSUPP; +} + +int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len, bool ingress) +{ + struct iphdr *iph; + bool ipv4; + int err; + + if (unlikely(len < sizeof(struct iphdr) || len > LWT_BPF_MAX_HEADROOM)) + return -EINVAL; + + /* validate protocol and length */ + iph = (struct iphdr *)hdr; + if (iph->version == 4) { + ipv4 = true; + if (unlikely(len < iph->ihl * 4)) + return -EINVAL; + } else if (iph->version == 6) { + ipv4 = false; + if (unlikely(len < sizeof(struct ipv6hdr))) + return -EINVAL; + } else { + return -EINVAL; + } + + if (ingress) + err = skb_cow_head(skb, len + skb->mac_len); + else + err = skb_cow_head(skb, + len + LL_RESERVED_SPACE(skb_dst(skb)->dev)); + if (unlikely(err)) + return err; + + /* push the encap headers and fix pointers */ + skb_reset_inner_headers(skb); + skb->encapsulation = 1; + skb_push(skb, len); + if (ingress) + skb_postpush_rcsum(skb, iph, len); + skb_reset_network_header(skb); + memcpy(skb_network_header(skb), hdr, len); + bpf_compute_data_pointers(skb); + skb_clear_hash(skb); + + if (ipv4) { + skb->protocol = htons(ETH_P_IP); + iph = ip_hdr(skb); + + if (!iph->check) + iph->check = ip_fast_csum((unsigned char *)iph, + iph->ihl); + } else { + skb->protocol = htons(ETH_P_IPV6); + } + + if (skb_is_gso(skb)) + return handle_gso_encap(skb, ipv4, len); + + return 0; +} + static int __init bpf_lwt_init(void) { return lwtunnel_encap_add_ops(&bpf_encap_ops, LWTUNNEL_ENCAP_BPF); -- 2.20.1.791.gb4d0f1c61a-goog