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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AB0A6C4708D for ; Fri, 6 Jan 2023 03:55:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230042AbjAFDzn (ORCPT ); Thu, 5 Jan 2023 22:55:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49640 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229451AbjAFDzm (ORCPT ); Thu, 5 Jan 2023 22:55:42 -0500 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CCD116B582; Thu, 5 Jan 2023 19:55:41 -0800 (PST) Received: from canpemm500006.china.huawei.com (unknown [172.30.72.56]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4Np8XV1BTvzJq5w; Fri, 6 Jan 2023 11:51:38 +0800 (CST) Received: from localhost.localdomain (10.175.104.82) by canpemm500006.china.huawei.com (7.192.105.130) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.34; Fri, 6 Jan 2023 11:55:39 +0800 From: Ziyang Xuan To: , , , , , , , , , , , , , , , , Subject: [PATCH bpf-next 1/2] bpf: Add ipip6 and ip6ip decap support for bpf_skb_adjust_room() Date: Fri, 6 Jan 2023 11:55:34 +0800 Message-ID: <7e9ca6837b20bea661248957dbbd1db198e3d1f8.1672976410.git.william.xuanziyang@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.104.82] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To canpemm500006.china.huawei.com (7.192.105.130) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Add ipip6 and ip6ip decap support for bpf_skb_adjust_room(). Main use case is for using cls_bpf on ingress hook to decapsulate IPv4 over IPv6 and IPv6 over IPv4 tunnel packets. Signed-off-by: Ziyang Xuan --- net/core/filter.c | 34 ++++++++++++++++++++++++++++++++-- 1 file changed, 32 insertions(+), 2 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index 929358677183..73982fb4fe2e 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3495,6 +3495,12 @@ static int bpf_skb_net_grow(struct sk_buff *skb, u32 off, u32 len_diff, static int bpf_skb_net_shrink(struct sk_buff *skb, u32 off, u32 len_diff, u64 flags) { + union { + struct iphdr *v4; + struct ipv6hdr *v6; + unsigned char *hdr; + } ip; + __be16 proto; int ret; if (unlikely(flags & ~(BPF_F_ADJ_ROOM_FIXED_GSO | @@ -3512,10 +3518,19 @@ static int bpf_skb_net_shrink(struct sk_buff *skb, u32 off, u32 len_diff, if (unlikely(ret < 0)) return ret; + ip.hdr = skb_inner_network_header(skb); + if (ip.v4->version == 4) + proto = htons(ETH_P_IP); + else + proto = htons(ETH_P_IPV6); + ret = bpf_skb_net_hdr_pop(skb, off, len_diff); if (unlikely(ret < 0)) return ret; + /* Match skb->protocol to new outer l3 protocol */ + skb->protocol = proto; + if (skb_is_gso(skb)) { struct skb_shared_info *shinfo = skb_shinfo(skb); @@ -3578,10 +3593,14 @@ BPF_CALL_4(bpf_skb_adjust_room, struct sk_buff *, skb, s32, len_diff, u32, mode, u64, flags) { u32 len_cur, len_diff_abs = abs(len_diff); - u32 len_min = bpf_skb_net_base_len(skb); - u32 len_max = BPF_SKB_MAX_LEN; + u32 len_min, len_max = BPF_SKB_MAX_LEN; __be16 proto = skb->protocol; bool shrink = len_diff < 0; + union { + struct iphdr *v4; + struct ipv6hdr *v6; + unsigned char *hdr; + } ip; u32 off; int ret; @@ -3594,6 +3613,9 @@ BPF_CALL_4(bpf_skb_adjust_room, struct sk_buff *, skb, s32, len_diff, proto != htons(ETH_P_IPV6))) return -ENOTSUPP; + if (unlikely(shrink && !skb->encapsulation)) + return -ENOTSUPP; + off = skb_mac_header_len(skb); switch (mode) { case BPF_ADJ_ROOM_NET: @@ -3605,6 +3627,14 @@ BPF_CALL_4(bpf_skb_adjust_room, struct sk_buff *, skb, s32, len_diff, return -ENOTSUPP; } + if (shrink) { + ip.hdr = skb_inner_network_header(skb); + if (ip.v4->version == 4) + len_min = sizeof(struct iphdr); + else + len_min = sizeof(struct ipv6hdr); + } + len_cur = skb->len - skb_network_offset(skb); if ((shrink && (len_diff_abs >= len_cur || len_cur - len_diff_abs < len_min)) || -- 2.25.1