From patchwork Wed Apr 25 10:30:24 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ahmed Abdelsalam X-Patchwork-Id: 904107 X-Patchwork-Delegate: pablo@netfilter.org Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netfilter-devel-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="gEO2bCLd"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 40WGgX1gVcz9s1j for ; Wed, 25 Apr 2018 20:30:48 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752173AbeDYKak (ORCPT ); Wed, 25 Apr 2018 06:30:40 -0400 Received: from mail-wr0-f196.google.com ([209.85.128.196]:45123 "EHLO mail-wr0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751544AbeDYKaf (ORCPT ); Wed, 25 Apr 2018 06:30:35 -0400 Received: by mail-wr0-f196.google.com with SMTP id p5-v6so25033289wre.12; Wed, 25 Apr 2018 03:30:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=kYem8P9QKfeqQUOGIwn0cr0ioOsykYzSS9qFDtJQERk=; b=gEO2bCLd7Qdnm2babEPaf0Rd9NMyxjS/eCYe8Hw9wsinuLtCwiloDPK/009FX+3VZK COJ+HeUJRrPMqUP7dRY9oJeeMtMCFes/5ElEjZxLNcS8E15h+4wGNu3t5xmGRY6iTe7M H2iNYMzzQAQraBzf16+N7ptiLa5dox7YhkNhm+7uNUL5BUV645SOz5kryGMbkCjQPxZr YHnWXRQXI1hy9xu2/r+JJQO6scTU8DfRDHVwXWQGMB308v7No55Okn8zS7tB74e+v8SR +JTd7qS+hifcqFenI9jGSoT6dZa52BBW1waGM25HnMW8LwHpoqOk2dO5XfJx+6r51NT0 1tDQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=kYem8P9QKfeqQUOGIwn0cr0ioOsykYzSS9qFDtJQERk=; b=Fx4o+cvmp20Ep2M/G2FpD2oH/lyHCaF+w04K5lOxyA6Iqy5qQEc0fI8yq31bxITcuM 3Irq1YHyDRqng9x3RafNROdQaOdeb2pIynWbbrJR+gscRiE0dHco1cHlxqhxF8zewQ89 i0LB0N9nLJkHxBhfjJAVnK5x+Xotwm5nxiIgt8Y5v15jPyeGf00knWBWxvLYQEIDaNCC 8/VBuICObMVViAsEZwGpeJFQZZF2knS5C3f8G4nSp8QHkW7CIn1ZF4wJauuXN7TDOPT5 1hJcPskNbu9y86ig4AMmZMKQ/iBiHxUQCbn2X3bMGOswbxV3/yAXYI0mk4gwwR1eh7S/ 1h2A== X-Gm-Message-State: ALQs6tDYd68RVyjqR2AiQd9KoRRJetbM5o93dl5ps2cbLIY0r9dikXfo fb6g3TSSEFGTUfh6qggJL84= X-Google-Smtp-Source: AIpwx4+QClwGlpRPegdF6CEGWvJKp86psfX7O+Lifd7nkLrhzPBFSdTNR34wNkGblzNQ23V4lYfKJA== X-Received: by 2002:adf:c4b6:: with SMTP id m51-v6mr23807183wrf.126.1524652233251; Wed, 25 Apr 2018 03:30:33 -0700 (PDT) Received: from localhost.localdomain ([192.135.27.140]) by smtp.gmail.com with ESMTPSA id j8-v6sm3888626wra.58.2018.04.25.03.30.31 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 25 Apr 2018 03:30:32 -0700 (PDT) From: Ahmed Abdelsalam To: pablo@netfilter.org, fw@strlen.de, davem@davemloft.net, linux-kernel@vger.kernel.org, netfilter-devel@vger.kernel.org, coreteam@netfilter.org Cc: Ahmed Abdelsalam Subject: [nf-next v2] netfilter: extend SRH matching for previous, next and last SID Date: Wed, 25 Apr 2018 05:30:24 -0500 Message-Id: <1524652224-1702-1-git-send-email-amsalam20@gmail.com> X-Mailer: git-send-email 2.1.4 Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org IPv6 Segment Routing Header (SRH) contains a list of SIDs to be crossed by SR encapsulated packet. Each SID is encoded as an IPv6 prefix. When a Firewall receives an SR encapsulated packet, it should be able to identify which node previously processed the packet (previous SID), which node is going to process the packet next (next SID), and which node is the last to process the packet (last SID) which represent the final destination of the packet in case of inline SR mode. An example use-case of using these features could be SID list that includes two firewalls. When the second firewall receives a packet, it can check whether the packet has been processed by the first firewall or not. Based on that check, it decides to apply all rules, apply just subset of the rules, or totally skip all rules and forward the packet to the next SID. This patch extends SRH match to support matching previous SID, next SID, and last SID. Signed-off-by: Ahmed Abdelsalam --- include/uapi/linux/netfilter_ipv6/ip6t_srh.h | 43 ++++++- net/ipv6/netfilter/ip6t_srh.c | 173 +++++++++++++++++++++++++-- 2 files changed, 205 insertions(+), 11 deletions(-) diff --git a/include/uapi/linux/netfilter_ipv6/ip6t_srh.h b/include/uapi/linux/netfilter_ipv6/ip6t_srh.h index f3cc0ef..54ed833 100644 --- a/include/uapi/linux/netfilter_ipv6/ip6t_srh.h +++ b/include/uapi/linux/netfilter_ipv6/ip6t_srh.h @@ -17,7 +17,10 @@ #define IP6T_SRH_LAST_GT 0x0100 #define IP6T_SRH_LAST_LT 0x0200 #define IP6T_SRH_TAG 0x0400 -#define IP6T_SRH_MASK 0x07FF +#define IP6T_SRH_PSID 0x0800 +#define IP6T_SRH_NSID 0x1000 +#define IP6T_SRH_LSID 0x2000 +#define IP6T_SRH_MASK 0x3FFF /* Values for "mt_invflags" field in struct ip6t_srh */ #define IP6T_SRH_INV_NEXTHDR 0x0001 @@ -31,7 +34,10 @@ #define IP6T_SRH_INV_LAST_GT 0x0100 #define IP6T_SRH_INV_LAST_LT 0x0200 #define IP6T_SRH_INV_TAG 0x0400 -#define IP6T_SRH_INV_MASK 0x07FF +#define IP6T_SRH_INV_PSID 0x0800 +#define IP6T_SRH_INV_NSID 0x1000 +#define IP6T_SRH_INV_LSID 0x2000 +#define IP6T_SRH_INV_MASK 0x3FFF /** * struct ip6t_srh - SRH match options @@ -54,4 +60,37 @@ struct ip6t_srh { __u16 mt_invflags; }; +/** + * struct ip6t_srh1 - SRH match options (revision 1) + * @ next_hdr: Next header field of SRH + * @ hdr_len: Extension header length field of SRH + * @ segs_left: Segments left field of SRH + * @ last_entry: Last entry field of SRH + * @ tag: Tag field of SRH + * @ psid_addr: Address of previous SID in SRH SID list + * @ nsid_addr: Address of NEXT SID in SRH SID list + * @ lsid_addr: Address of LAST SID in SRH SID list + * @ psid_msk: Mask of previous SID in SRH SID list + * @ nsid_msk: Mask of next SID in SRH SID list + * @ lsid_msk: MAsk of last SID in SRH SID list + * @ mt_flags: match options + * @ mt_invflags: Invert the sense of match options + */ + +struct ip6t_srh1 { + __u8 next_hdr; + __u8 hdr_len; + __u8 segs_left; + __u8 last_entry; + __u16 tag; + struct in6_addr psid_addr; + struct in6_addr nsid_addr; + struct in6_addr lsid_addr; + struct in6_addr psid_msk; + struct in6_addr nsid_msk; + struct in6_addr lsid_msk; + __u16 mt_flags; + __u16 mt_invflags; +}; + #endif /*_IP6T_SRH_H*/ diff --git a/net/ipv6/netfilter/ip6t_srh.c b/net/ipv6/netfilter/ip6t_srh.c index 33719d5..1059894 100644 --- a/net/ipv6/netfilter/ip6t_srh.c +++ b/net/ipv6/netfilter/ip6t_srh.c @@ -117,6 +117,130 @@ static bool srh_mt6(const struct sk_buff *skb, struct xt_action_param *par) return true; } +static bool srh1_mt6(const struct sk_buff *skb, struct xt_action_param *par) +{ + int hdrlen, psidoff, nsidoff, lsidoff, srhoff = 0; + const struct ip6t_srh1 *srhinfo = par->matchinfo; + struct in6_addr *psid, *nsid, *lsid; + struct in6_addr _psid, _nsid, _lsid; + struct ipv6_sr_hdr *srh; + struct ipv6_sr_hdr _srh; + + if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, NULL) < 0) + return false; + srh = skb_header_pointer(skb, srhoff, sizeof(_srh), &_srh); + if (!srh) + return false; + + hdrlen = ipv6_optlen(srh); + if (skb->len - srhoff < hdrlen) + return false; + + if (srh->type != IPV6_SRCRT_TYPE_4) + return false; + + if (srh->segments_left > srh->first_segment) + return false; + + /* Next Header matching */ + if (srhinfo->mt_flags & IP6T_SRH_NEXTHDR) + if (NF_SRH_INVF(srhinfo, IP6T_SRH_INV_NEXTHDR, + !(srh->nexthdr == srhinfo->next_hdr))) + return false; + + /* Header Extension Length matching */ + if (srhinfo->mt_flags & IP6T_SRH_LEN_EQ) + if (NF_SRH_INVF(srhinfo, IP6T_SRH_INV_LEN_EQ, + !(srh->hdrlen == srhinfo->hdr_len))) + return false; + if (srhinfo->mt_flags & IP6T_SRH_LEN_GT) + if (NF_SRH_INVF(srhinfo, IP6T_SRH_INV_LEN_GT, + !(srh->hdrlen > srhinfo->hdr_len))) + return false; + if (srhinfo->mt_flags & IP6T_SRH_LEN_LT) + if (NF_SRH_INVF(srhinfo, IP6T_SRH_INV_LEN_LT, + !(srh->hdrlen < srhinfo->hdr_len))) + return false; + + /* Segments Left matching */ + if (srhinfo->mt_flags & IP6T_SRH_SEGS_EQ) + if (NF_SRH_INVF(srhinfo, IP6T_SRH_INV_SEGS_EQ, + !(srh->segments_left == srhinfo->segs_left))) + return false; + if (srhinfo->mt_flags & IP6T_SRH_SEGS_GT) + if (NF_SRH_INVF(srhinfo, IP6T_SRH_INV_SEGS_GT, + !(srh->segments_left > srhinfo->segs_left))) + return false; + if (srhinfo->mt_flags & IP6T_SRH_SEGS_LT) + if (NF_SRH_INVF(srhinfo, IP6T_SRH_INV_SEGS_LT, + !(srh->segments_left < srhinfo->segs_left))) + return false; + + /** + * Last Entry matching + * Last_Entry field was introduced in revision 6 of the SRH draft. + * It was called First_Segment in the previous revision + */ + if (srhinfo->mt_flags & IP6T_SRH_LAST_EQ) + if (NF_SRH_INVF(srhinfo, IP6T_SRH_INV_LAST_EQ, + !(srh->first_segment == srhinfo->last_entry))) + return false; + if (srhinfo->mt_flags & IP6T_SRH_LAST_GT) + if (NF_SRH_INVF(srhinfo, IP6T_SRH_INV_LAST_GT, + !(srh->first_segment > srhinfo->last_entry))) + return false; + if (srhinfo->mt_flags & IP6T_SRH_LAST_LT) + if (NF_SRH_INVF(srhinfo, IP6T_SRH_INV_LAST_LT, + !(srh->first_segment < srhinfo->last_entry))) + return false; + + /** + * Tag matchig + * Tag field was introduced in revision 6 of the SRH draft + */ + if (srhinfo->mt_flags & IP6T_SRH_TAG) + if (NF_SRH_INVF(srhinfo, IP6T_SRH_INV_TAG, + !(srh->tag == srhinfo->tag))) + return false; + + /* Previous SID matching */ + if (srhinfo->mt_flags & IP6T_SRH_PSID) { + if (srh->segments_left == srh->first_segment) + return false; + psidoff = srhoff + sizeof(struct ipv6_sr_hdr) + + ((srh->segments_left + 1) * sizeof(struct in6_addr)); + psid = skb_header_pointer(skb, psidoff, sizeof(_psid), &_psid); + if (NF_SRH_INVF(srhinfo, IP6T_SRH_INV_PSID, + ipv6_masked_addr_cmp(psid, &srhinfo->psid_msk, + &srhinfo->psid_addr))) + return false; + } + + /* Next SID matching */ + if (srhinfo->mt_flags & IP6T_SRH_NSID) { + if (srh->segments_left == 0) + return false; + nsidoff = srhoff + sizeof(struct ipv6_sr_hdr) + + ((srh->segments_left - 1) * sizeof(struct in6_addr)); + nsid = skb_header_pointer(skb, nsidoff, sizeof(_nsid), &_nsid); + if (NF_SRH_INVF(srhinfo, IP6T_SRH_INV_NSID, + ipv6_masked_addr_cmp(nsid, &srhinfo->nsid_msk, + &srhinfo->nsid_addr))) + return false; + } + + /* Last SID matching */ + if (srhinfo->mt_flags & IP6T_SRH_LSID) { + lsidoff = srhoff + sizeof(struct ipv6_sr_hdr); + lsid = skb_header_pointer(skb, lsidoff, sizeof(_lsid), &_lsid); + if (NF_SRH_INVF(srhinfo, IP6T_SRH_INV_LSID, + ipv6_masked_addr_cmp(lsid, &srhinfo->lsid_msk, + &srhinfo->lsid_addr))) + return false; + } + return true; +} + static int srh_mt6_check(const struct xt_mtchk_param *par) { const struct ip6t_srh *srhinfo = par->matchinfo; @@ -136,23 +260,54 @@ static int srh_mt6_check(const struct xt_mtchk_param *par) return 0; } -static struct xt_match srh_mt6_reg __read_mostly = { - .name = "srh", - .family = NFPROTO_IPV6, - .match = srh_mt6, - .matchsize = sizeof(struct ip6t_srh), - .checkentry = srh_mt6_check, - .me = THIS_MODULE, +static int srh1_mt6_check(const struct xt_mtchk_param *par) +{ + const struct ip6t_srh1 *srhinfo = par->matchinfo; + + if (srhinfo->mt_flags & ~IP6T_SRH_MASK) { + pr_info_ratelimited("unknown srh match flags %X\n", + srhinfo->mt_flags); + return -EINVAL; + } + + if (srhinfo->mt_invflags & ~IP6T_SRH_INV_MASK) { + pr_info_ratelimited("unknown srh invflags %X\n", + srhinfo->mt_invflags); + return -EINVAL; + } + + return 0; +} + +static struct xt_match srh_mt6_reg[] __read_mostly = { + { + .name = "srh", + .revision = 0, + .family = NFPROTO_IPV6, + .match = srh_mt6, + .matchsize = sizeof(struct ip6t_srh), + .checkentry = srh_mt6_check, + .me = THIS_MODULE, + }, + { + .name = "srh", + .revision = 1, + .family = NFPROTO_IPV6, + .match = srh1_mt6, + .matchsize = sizeof(struct ip6t_srh1), + .checkentry = srh1_mt6_check, + .me = THIS_MODULE, + } }; static int __init srh_mt6_init(void) { - return xt_register_match(&srh_mt6_reg); + return xt_register_matches(srh_mt6_reg, ARRAY_SIZE(srh_mt6_reg)); } static void __exit srh_mt6_exit(void) { - xt_unregister_match(&srh_mt6_reg); + xt_unregister_matches(srh_mt6_reg, ARRAY_SIZE(srh_mt6_reg)); } module_init(srh_mt6_init);