From patchwork Wed Feb 8 11:43:17 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steffen Klassert X-Patchwork-Id: 13133003 X-Patchwork-Delegate: kuba@kernel.org 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 7DBA8C636CC for ; Wed, 8 Feb 2023 11:43:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229894AbjBHLne (ORCPT ); Wed, 8 Feb 2023 06:43:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36938 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229630AbjBHLna (ORCPT ); Wed, 8 Feb 2023 06:43:30 -0500 Received: from a.mx.secunet.com (a.mx.secunet.com [62.96.220.36]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D12F6442F1 for ; Wed, 8 Feb 2023 03:43:28 -0800 (PST) Received: from localhost (localhost [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id D67C120660; Wed, 8 Feb 2023 12:43:26 +0100 (CET) X-Virus-Scanned: by secunet Received: from a.mx.secunet.com ([127.0.0.1]) by localhost (a.mx.secunet.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id okz5jzu9idao; Wed, 8 Feb 2023 12:43:26 +0100 (CET) Received: from mailout1.secunet.com (mailout1.secunet.com [62.96.220.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by a.mx.secunet.com (Postfix) with ESMTPS id 39B6720653; Wed, 8 Feb 2023 12:43:26 +0100 (CET) Received: from cas-essen-01.secunet.de (unknown [10.53.40.201]) by mailout1.secunet.com (Postfix) with ESMTP id 2826080004A; Wed, 8 Feb 2023 12:43:26 +0100 (CET) Received: from mbx-essen-01.secunet.de (10.53.40.197) by cas-essen-01.secunet.de (10.53.40.201) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.17; Wed, 8 Feb 2023 12:43:25 +0100 Received: from gauss2.secunet.de (10.182.7.193) by mbx-essen-01.secunet.de (10.53.40.197) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.17; Wed, 8 Feb 2023 12:43:25 +0100 Received: by gauss2.secunet.de (Postfix, from userid 1000) id 67DAB318022F; Wed, 8 Feb 2023 12:43:25 +0100 (CET) From: Steffen Klassert To: David Miller , Jakub Kicinski CC: Herbert Xu , Steffen Klassert , Subject: [PATCH 1/6] Fix XFRM-I support for nested ESP tunnels Date: Wed, 8 Feb 2023 12:43:17 +0100 Message-ID: <20230208114322.266510-2-steffen.klassert@secunet.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230208114322.266510-1-steffen.klassert@secunet.com> References: <20230208114322.266510-1-steffen.klassert@secunet.com> MIME-Version: 1.0 X-ClientProxiedBy: cas-essen-01.secunet.de (10.53.40.201) To mbx-essen-01.secunet.de (10.53.40.197) X-EXCLAIMER-MD-CONFIG: 2c86f778-e09b-4440-8b15-867914633a10 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Benedict Wong This change adds support for nested IPsec tunnels by ensuring that XFRM-I verifies existing policies before decapsulating a subsequent policies. Addtionally, this clears the secpath entries after policies are verified, ensuring that previous tunnels with no-longer-valid do not pollute subsequent policy checks. This is necessary especially for nested tunnels, as the IP addresses, protocol and ports may all change, thus not matching the previous policies. In order to ensure that packets match the relevant inbound templates, the xfrm_policy_check should be done before handing off to the inner XFRM protocol to decrypt and decapsulate. Notably, raw ESP/AH packets did not perform policy checks inherently, whereas all other encapsulated packets (UDP, TCP encapsulated) do policy checks after calling xfrm_input handling in the respective encapsulation layer. Test: Verified with additional Android Kernel Unit tests Signed-off-by: Benedict Wong Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_interface_core.c | 54 +++++++++++++++++++++++++++++++--- net/xfrm/xfrm_policy.c | 3 ++ 2 files changed, 53 insertions(+), 4 deletions(-) diff --git a/net/xfrm/xfrm_interface_core.c b/net/xfrm/xfrm_interface_core.c index 1f99dc469027..35279c220bd7 100644 --- a/net/xfrm/xfrm_interface_core.c +++ b/net/xfrm/xfrm_interface_core.c @@ -310,6 +310,52 @@ static void xfrmi_scrub_packet(struct sk_buff *skb, bool xnet) skb->mark = 0; } +static int xfrmi_input(struct sk_buff *skb, int nexthdr, __be32 spi, + int encap_type, unsigned short family) +{ + struct sec_path *sp; + + sp = skb_sec_path(skb); + if (sp && (sp->len || sp->olen) && + !xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family)) + goto discard; + + XFRM_SPI_SKB_CB(skb)->family = family; + if (family == AF_INET) { + XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr); + XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL; + } else { + XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr); + XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL; + } + + return xfrm_input(skb, nexthdr, spi, encap_type); +discard: + kfree_skb(skb); + return 0; +} + +static int xfrmi4_rcv(struct sk_buff *skb) +{ + return xfrmi_input(skb, ip_hdr(skb)->protocol, 0, 0, AF_INET); +} + +static int xfrmi6_rcv(struct sk_buff *skb) +{ + return xfrmi_input(skb, skb_network_header(skb)[IP6CB(skb)->nhoff], + 0, 0, AF_INET6); +} + +static int xfrmi4_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type) +{ + return xfrmi_input(skb, nexthdr, spi, encap_type, AF_INET); +} + +static int xfrmi6_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type) +{ + return xfrmi_input(skb, nexthdr, spi, encap_type, AF_INET6); +} + static int xfrmi_rcv_cb(struct sk_buff *skb, int err) { const struct xfrm_mode *inner_mode; @@ -945,8 +991,8 @@ static struct pernet_operations xfrmi_net_ops = { }; static struct xfrm6_protocol xfrmi_esp6_protocol __read_mostly = { - .handler = xfrm6_rcv, - .input_handler = xfrm_input, + .handler = xfrmi6_rcv, + .input_handler = xfrmi6_input, .cb_handler = xfrmi_rcv_cb, .err_handler = xfrmi6_err, .priority = 10, @@ -996,8 +1042,8 @@ static struct xfrm6_tunnel xfrmi_ip6ip_handler __read_mostly = { #endif static struct xfrm4_protocol xfrmi_esp4_protocol __read_mostly = { - .handler = xfrm4_rcv, - .input_handler = xfrm_input, + .handler = xfrmi4_rcv, + .input_handler = xfrmi4_input, .cb_handler = xfrmi_rcv_cb, .err_handler = xfrmi4_err, .priority = 10, diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index e9eb82c5457d..ed0976f8e42b 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -3742,6 +3742,9 @@ int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, goto reject; } + if (if_id) + secpath_reset(skb); + xfrm_pols_put(pols, npols); return 1; }