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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 9F22BC35247 for ; Mon, 3 Feb 2020 16:42:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 75FB82086A for ; Mon, 3 Feb 2020 16:42:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580748164; bh=FGJN0gO2TBuNggdZwA7nnuBdLJL26KjsnjsQZvVTKJs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=RQXQ86rmYDwfV0VQnIUrR24RMtaBn5DII/dShNUVkUSUpPJ4ocOfm+zm6OHvHGzLa /nTA8yPWxNSxuEYUzV/5LADSusK4Ck1Gt5Aep93mC4yx7/VHoJJyPBKx/rVcl27904 cHiFVl3UZ1Vv+shoSax3jDTli7z2eA/7ddCJ+3wc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730681AbgBCQdx (ORCPT ); Mon, 3 Feb 2020 11:33:53 -0500 Received: from mail.kernel.org ([198.145.29.99]:47934 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730173AbgBCQdv (ORCPT ); Mon, 3 Feb 2020 11:33:51 -0500 Received: from localhost (unknown [104.132.45.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7846521775; Mon, 3 Feb 2020 16:33:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580747629; bh=FGJN0gO2TBuNggdZwA7nnuBdLJL26KjsnjsQZvVTKJs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZcSlloEw0k+J+vV1HXwJDLV/A7rCNGZ6gLDRT7XYALFVcOOybFyhZDJRv1udOddgz FFcQluVpEs0uitNnMPcEcnPD3Srz4VCdl58LpOSuEgV38VpDzKPXm0BAyLJHmpC7QU F+brz9wm/b97Iu/5hXBrmLIIz3bP9Tq1M8H6yWls= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nicolas Dichtel , Steffen Klassert , Sasha Levin Subject: [PATCH 4.19 55/70] xfrm interface: fix packet tx through bpf_redirect() Date: Mon, 3 Feb 2020 16:20:07 +0000 Message-Id: <20200203161920.275797541@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200203161912.158976871@linuxfoundation.org> References: <20200203161912.158976871@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nicolas Dichtel [ Upstream commit f042365dbffea98fb8148c98c700402e8d099f02 ] With an ebpf program that redirects packets through a xfrm interface, packets are dropped because no dst is attached to skb. This could also be reproduced with an AF_PACKET socket, with the following python script (xfrm1 is a xfrm interface): import socket send_s = socket.socket(socket.AF_PACKET, socket.SOCK_RAW, 0) # scapy # p = IP(src='10.100.0.2', dst='10.200.0.1')/ICMP(type='echo-request') # raw(p) req = b'E\x00\x00\x1c\x00\x01\x00\x00@\x01e\xb2\nd\x00\x02\n\xc8\x00\x01\x08\x00\xf7\xff\x00\x00\x00\x00' send_s.sendto(req, ('xfrm1', 0x800, 0, 0)) It was also not possible to send an ip packet through an AF_PACKET socket because a LL header was expected. Let's remove those LL header constraints. Signed-off-by: Nicolas Dichtel Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin --- net/xfrm/xfrm_interface.c | 32 +++++++++++++++++++++++++------- 1 file changed, 25 insertions(+), 7 deletions(-) diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface.c index 4ee512622e93d..20565a4742112 100644 --- a/net/xfrm/xfrm_interface.c +++ b/net/xfrm/xfrm_interface.c @@ -268,9 +268,6 @@ xfrmi_xmit2(struct sk_buff *skb, struct net_device *dev, struct flowi *fl) int err = -1; int mtu; - if (!dst) - goto tx_err_link_failure; - dst_hold(dst); dst = xfrm_lookup_with_ifid(xi->net, dst, fl, NULL, 0, xi->p.if_id); if (IS_ERR(dst)) { @@ -343,6 +340,7 @@ static netdev_tx_t xfrmi_xmit(struct sk_buff *skb, struct net_device *dev) { struct xfrm_if *xi = netdev_priv(dev); struct net_device_stats *stats = &xi->dev->stats; + struct dst_entry *dst = skb_dst(skb); struct flowi fl; int ret; @@ -352,10 +350,33 @@ static netdev_tx_t xfrmi_xmit(struct sk_buff *skb, struct net_device *dev) case htons(ETH_P_IPV6): xfrm_decode_session(skb, &fl, AF_INET6); memset(IP6CB(skb), 0, sizeof(*IP6CB(skb))); + if (!dst) { + fl.u.ip6.flowi6_oif = dev->ifindex; + fl.u.ip6.flowi6_flags |= FLOWI_FLAG_ANYSRC; + dst = ip6_route_output(dev_net(dev), NULL, &fl.u.ip6); + if (dst->error) { + dst_release(dst); + stats->tx_carrier_errors++; + goto tx_err; + } + skb_dst_set(skb, dst); + } break; case htons(ETH_P_IP): xfrm_decode_session(skb, &fl, AF_INET); memset(IPCB(skb), 0, sizeof(*IPCB(skb))); + if (!dst) { + struct rtable *rt; + + fl.u.ip4.flowi4_oif = dev->ifindex; + fl.u.ip4.flowi4_flags |= FLOWI_FLAG_ANYSRC; + rt = __ip_route_output_key(dev_net(dev), &fl.u.ip4); + if (IS_ERR(rt)) { + stats->tx_carrier_errors++; + goto tx_err; + } + skb_dst_set(skb, &rt->dst); + } break; default: goto tx_err; @@ -566,12 +587,9 @@ static void xfrmi_dev_setup(struct net_device *dev) { dev->netdev_ops = &xfrmi_netdev_ops; dev->type = ARPHRD_NONE; - dev->hard_header_len = ETH_HLEN; - dev->min_header_len = ETH_HLEN; dev->mtu = ETH_DATA_LEN; dev->min_mtu = ETH_MIN_MTU; - dev->max_mtu = ETH_DATA_LEN; - dev->addr_len = ETH_ALEN; + dev->max_mtu = IP_MAX_MTU; dev->flags = IFF_NOARP; dev->needs_free_netdev = true; dev->priv_destructor = xfrmi_dev_free; -- 2.20.1