From patchwork Wed May 9 11:33:04 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 157921 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 9A672B6FA4 for ; Wed, 9 May 2012 21:34:12 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758069Ab2EILdi (ORCPT ); Wed, 9 May 2012 07:33:38 -0400 Received: from mail.us.es ([193.147.175.20]:33879 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757180Ab2EILdf (ORCPT ); Wed, 9 May 2012 07:33:35 -0400 Received: (qmail 13826 invoked from network); 9 May 2012 13:33:33 +0200 Received: from unknown (HELO us.es) (192.168.2.12) by us.es with SMTP; 9 May 2012 13:33:33 +0200 Received: (qmail 18240 invoked by uid 507); 9 May 2012 11:33:30 -0000 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on antivirus2 X-Spam-Level: X-Spam-Status: No, score=-97.2 required=7.5 tests=BAYES_50,KHOP_DYNAMIC, RCVD_IN_PBL, RCVD_IN_RP_RNBL, RCVD_IN_SORBS_DUL, RDNS_DYNAMIC, USER_IN_WHITELIST autolearn=disabled version=3.3.1 Received: from 127.0.0.1 by antivirus2 (envelope-from , uid 501) with qmail-scanner-2.08 (clamdscan: 0.97.4/14898. 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Processed in 0.029705 secs); 09 May 2012 11:33:30 -0000 Received: from unknown (HELO antivirus2) (127.0.0.1) by us.es with SMTP; 9 May 2012 11:33:30 -0000 Received: from 192.168.1.13 (192.168.1.13) by antivirus2 (F-Secure/fsigk_smtp/407/antivirus2); Wed, 09 May 2012 13:33:30 +0200 (CEST) X-Virus-Status: clean(F-Secure/fsigk_smtp/407/antivirus2) Received: (qmail 2114 invoked from network); 9 May 2012 13:33:40 +0200 Received: from 199.139.221.87.dynamic.jazztel.es (HELO localhost.localdomain) (pneira@us.es@87.221.139.199) by us.es with SMTP; 9 May 2012 13:33:40 +0200 From: pablo@netfilter.org To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org Subject: [PATCH 1/5] netfilter: ip6_tables: add flags parameter to ipv6_find_hdr() Date: Wed, 9 May 2012 13:33:04 +0200 Message-Id: <1336563188-6720-2-git-send-email-pablo@netfilter.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1336563188-6720-1-git-send-email-pablo@netfilter.org> References: <1336563188-6720-1-git-send-email-pablo@netfilter.org> Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org From: Hans Schillstrom This patch adds the flags parameter to ipv6_find_hdr. This flags allows us to: * know if this is a fragment. * stop at the AH header, so the information contained in that header can be used for some specific packet handling. This patch also adds the offset parameter for inspection of one inner IPv6 header that is contained in error messages. Signed-off-by: Hans Schillstrom Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter_ipv6/ip6_tables.h | 7 +++++- net/ipv6/netfilter/ip6_tables.c | 36 +++++++++++++++++++++++++---- net/ipv6/netfilter/ip6t_ah.c | 4 ++-- net/ipv6/netfilter/ip6t_frag.c | 4 ++-- net/ipv6/netfilter/ip6t_hbh.c | 4 ++-- net/ipv6/netfilter/ip6t_rt.c | 4 ++-- net/netfilter/xt_TPROXY.c | 4 ++-- net/netfilter/xt_socket.c | 4 ++-- 8 files changed, 49 insertions(+), 18 deletions(-) diff --git a/include/linux/netfilter_ipv6/ip6_tables.h b/include/linux/netfilter_ipv6/ip6_tables.h index 1bc898b..08c2cbb 100644 --- a/include/linux/netfilter_ipv6/ip6_tables.h +++ b/include/linux/netfilter_ipv6/ip6_tables.h @@ -298,9 +298,14 @@ ip6t_ext_hdr(u8 nexthdr) (nexthdr == IPPROTO_DSTOPTS); } +enum { + IP6T_FH_F_FRAG = (1 << 0), + IP6T_FH_F_AUTH = (1 << 1), +}; + /* find specified header and get offset to it */ extern int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, - int target, unsigned short *fragoff); + int target, unsigned short *fragoff, int *fragflg); #ifdef CONFIG_COMPAT #include diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c index d4e350f..308bdd6 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -133,7 +133,7 @@ ip6_packet_match(const struct sk_buff *skb, int protohdr; unsigned short _frag_off; - protohdr = ipv6_find_hdr(skb, protoff, -1, &_frag_off); + protohdr = ipv6_find_hdr(skb, protoff, -1, &_frag_off, NULL); if (protohdr < 0) { if (_frag_off == 0) *hotdrop = true; @@ -362,6 +362,7 @@ ip6t_do_table(struct sk_buff *skb, const struct xt_entry_match *ematch; IP_NF_ASSERT(e); + acpar.thoff = 0; if (!ip6_packet_match(skb, indev, outdev, &e->ipv6, &acpar.thoff, &acpar.fragoff, &acpar.hotdrop)) { no_match: @@ -2278,6 +2279,10 @@ static void __exit ip6_tables_fini(void) * if target < 0. "last header" is transport protocol header, ESP, or * "No next header". * + * Note that *offset is used as input/output parameter. an if it is not zero, + * then it must be a valid offset to an inner IPv6 header. This can be used + * to explore inner IPv6 header, eg. ICMPv6 error messages. + * * If target header is found, its offset is set in *offset and return protocol * number. Otherwise, return -1. * @@ -2289,17 +2294,33 @@ static void __exit ip6_tables_fini(void) * *offset is meaningless and fragment offset is stored in *fragoff if fragoff * isn't NULL. * + * if flags is not NULL and it's a fragment, then the frag flag IP6T_FH_F_FRAG + * will be set. If it's an AH header, the IP6T_FH_F_AUTH flag is set and + * target < 0, then this function will stop at the AH header. */ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, - int target, unsigned short *fragoff) + int target, unsigned short *fragoff, int *flags) { unsigned int start = skb_network_offset(skb) + sizeof(struct ipv6hdr); u8 nexthdr = ipv6_hdr(skb)->nexthdr; - unsigned int len = skb->len - start; + unsigned int len; if (fragoff) *fragoff = 0; + if (*offset) { + struct ipv6hdr _ip6, *ip6; + + ip6 = skb_header_pointer(skb, *offset, sizeof(_ip6), &_ip6); + if (!ip6 || (ip6->version != 6)) { + printk(KERN_ERR "IPv6 header not found\n"); + return -EBADMSG; + } + start = *offset + sizeof(struct ipv6hdr); + nexthdr = ip6->nexthdr; + } + len = skb->len - start; + while (nexthdr != target) { struct ipv6_opt_hdr _hdr, *hp; unsigned int hdrlen; @@ -2316,6 +2337,9 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, if (nexthdr == NEXTHDR_FRAGMENT) { unsigned short _frag_off; __be16 *fp; + + if (flags) /* Indicate that this is a fragment */ + *flags |= IP6T_FH_F_FRAG; fp = skb_header_pointer(skb, start+offsetof(struct frag_hdr, frag_off), @@ -2336,9 +2360,11 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, return -ENOENT; } hdrlen = 8; - } else if (nexthdr == NEXTHDR_AUTH) + } else if (nexthdr == NEXTHDR_AUTH) { + if (flags && (*flags & IP6T_FH_F_AUTH) && (target < 0)) + break; hdrlen = (hp->hdrlen + 2) << 2; - else + } else hdrlen = ipv6_optlen(hp); nexthdr = hp->nexthdr; diff --git a/net/ipv6/netfilter/ip6t_ah.c b/net/ipv6/netfilter/ip6t_ah.c index 89cccc5..04099ab 100644 --- a/net/ipv6/netfilter/ip6t_ah.c +++ b/net/ipv6/netfilter/ip6t_ah.c @@ -41,11 +41,11 @@ static bool ah_mt6(const struct sk_buff *skb, struct xt_action_param *par) struct ip_auth_hdr _ah; const struct ip_auth_hdr *ah; const struct ip6t_ah *ahinfo = par->matchinfo; - unsigned int ptr; + unsigned int ptr = 0; unsigned int hdrlen = 0; int err; - err = ipv6_find_hdr(skb, &ptr, NEXTHDR_AUTH, NULL); + err = ipv6_find_hdr(skb, &ptr, NEXTHDR_AUTH, NULL, NULL); if (err < 0) { if (err != -ENOENT) par->hotdrop = true; diff --git a/net/ipv6/netfilter/ip6t_frag.c b/net/ipv6/netfilter/ip6t_frag.c index eda898f..3b5735e 100644 --- a/net/ipv6/netfilter/ip6t_frag.c +++ b/net/ipv6/netfilter/ip6t_frag.c @@ -40,10 +40,10 @@ frag_mt6(const struct sk_buff *skb, struct xt_action_param *par) struct frag_hdr _frag; const struct frag_hdr *fh; const struct ip6t_frag *fraginfo = par->matchinfo; - unsigned int ptr; + unsigned int ptr = 0; int err; - err = ipv6_find_hdr(skb, &ptr, NEXTHDR_FRAGMENT, NULL); + err = ipv6_find_hdr(skb, &ptr, NEXTHDR_FRAGMENT, NULL, NULL); if (err < 0) { if (err != -ENOENT) par->hotdrop = true; diff --git a/net/ipv6/netfilter/ip6t_hbh.c b/net/ipv6/netfilter/ip6t_hbh.c index 59df051..01df142 100644 --- a/net/ipv6/netfilter/ip6t_hbh.c +++ b/net/ipv6/netfilter/ip6t_hbh.c @@ -50,7 +50,7 @@ hbh_mt6(const struct sk_buff *skb, struct xt_action_param *par) const struct ipv6_opt_hdr *oh; const struct ip6t_opts *optinfo = par->matchinfo; unsigned int temp; - unsigned int ptr; + unsigned int ptr = 0; unsigned int hdrlen = 0; bool ret = false; u8 _opttype; @@ -62,7 +62,7 @@ hbh_mt6(const struct sk_buff *skb, struct xt_action_param *par) err = ipv6_find_hdr(skb, &ptr, (par->match == &hbh_mt6_reg[0]) ? - NEXTHDR_HOP : NEXTHDR_DEST, NULL); + NEXTHDR_HOP : NEXTHDR_DEST, NULL, NULL); if (err < 0) { if (err != -ENOENT) par->hotdrop = true; diff --git a/net/ipv6/netfilter/ip6t_rt.c b/net/ipv6/netfilter/ip6t_rt.c index d8488c5..2c99b94 100644 --- a/net/ipv6/netfilter/ip6t_rt.c +++ b/net/ipv6/netfilter/ip6t_rt.c @@ -42,14 +42,14 @@ static bool rt_mt6(const struct sk_buff *skb, struct xt_action_param *par) const struct ipv6_rt_hdr *rh; const struct ip6t_rt *rtinfo = par->matchinfo; unsigned int temp; - unsigned int ptr; + unsigned int ptr = 0; unsigned int hdrlen = 0; bool ret = false; struct in6_addr _addr; const struct in6_addr *ap; int err; - err = ipv6_find_hdr(skb, &ptr, NEXTHDR_ROUTING, NULL); + err = ipv6_find_hdr(skb, &ptr, NEXTHDR_ROUTING, NULL, NULL); if (err < 0) { if (err != -ENOENT) par->hotdrop = true; diff --git a/net/netfilter/xt_TPROXY.c b/net/netfilter/xt_TPROXY.c index 35a959a..146033a 100644 --- a/net/netfilter/xt_TPROXY.c +++ b/net/netfilter/xt_TPROXY.c @@ -282,10 +282,10 @@ tproxy_tg6_v1(struct sk_buff *skb, const struct xt_action_param *par) struct sock *sk; const struct in6_addr *laddr; __be16 lport; - int thoff; + int thoff = 0; int tproto; - tproto = ipv6_find_hdr(skb, &thoff, -1, NULL); + tproto = ipv6_find_hdr(skb, &thoff, -1, NULL, NULL); if (tproto < 0) { pr_debug("unable to find transport header in IPv6 packet, dropping\n"); return NF_DROP; diff --git a/net/netfilter/xt_socket.c b/net/netfilter/xt_socket.c index 72bb07f..9ea482d 100644 --- a/net/netfilter/xt_socket.c +++ b/net/netfilter/xt_socket.c @@ -263,10 +263,10 @@ socket_mt6_v1(const struct sk_buff *skb, struct xt_action_param *par) struct sock *sk; struct in6_addr *daddr, *saddr; __be16 dport, sport; - int thoff, tproto; + int thoff = 0, tproto; const struct xt_socket_mtinfo1 *info = (struct xt_socket_mtinfo1 *) par->matchinfo; - tproto = ipv6_find_hdr(skb, &thoff, -1, NULL); + tproto = ipv6_find_hdr(skb, &thoff, -1, NULL, NULL); if (tproto < 0) { pr_debug("unable to find transport header in IPv6 packet, dropping\n"); return NF_DROP;