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 B9AE2C433F5 for ; Fri, 7 Oct 2022 09:16:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229891AbiJGJQe (ORCPT ); Fri, 7 Oct 2022 05:16:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41304 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229919AbiJGJQT (ORCPT ); Fri, 7 Oct 2022 05:16:19 -0400 Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 7783CA0245 for ; Fri, 7 Oct 2022 02:16:18 -0700 (PDT) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Subject: [PATCH nf-next,v3 1/6] netfilter: nft_payload: access GRE payload via inner offset Date: Fri, 7 Oct 2022 11:16:09 +0200 Message-Id: <20221007091614.339582-2-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221007091614.339582-1-pablo@netfilter.org> References: <20221007091614.339582-1-pablo@netfilter.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org Parse GRE packets to properly set up inner offset, this allow for matching on inner headers. This includes support for GRE v0 and v1. Signed-off-by: Pablo Neira Ayuso --- v3: handle GREv0 and GREv1. net/netfilter/nft_payload.c | 38 +++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index 99d971fc54ad..448e32750fa0 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -19,6 +19,8 @@ /* For layer 4 checksum field offset. */ #include #include +#include +#include #include #include #include @@ -100,6 +102,42 @@ static int __nft_payload_inner_offset(struct nft_pktinfo *pkt) pkt->inneroff = thoff + __tcp_hdrlen(th); } break; + case IPPROTO_GRE: { + u32 offset = sizeof(struct gre_base_hdr), version; + struct gre_base_hdr *gre, _gre; + + gre = skb_header_pointer(pkt->skb, thoff, sizeof(_gre), &_gre); + if (!gre) + return -1; + + version = gre->flags & GRE_VERSION; + switch (version) { + case GRE_VERSION_0: + if (gre->flags & GRE_CSUM) { + offset += sizeof_field(struct gre_full_hdr, csum) + + sizeof_field(struct gre_full_hdr, reserved1); + } + if (gre->flags & GRE_KEY) + offset += sizeof_field(struct gre_full_hdr, key); + + if (gre->flags & GRE_SEQ) + offset += sizeof_field(struct pptp_gre_header, seq); + break; + case GRE_VERSION_1: + offset += sizeof_field(struct pptp_gre_header, payload_len) + + sizeof_field(struct pptp_gre_header, call_id); + + if (gre->flags & GRE_SEQ) + offset += sizeof_field(struct pptp_gre_header, seq); + + if (gre->flags & GRE_ACK) + offset += sizeof_field(struct pptp_gre_header, ack); + break; + } + + pkt->inneroff = thoff + offset; + } + break; default: return -1; } -- 2.30.2