From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans Schillstrom Subject: [v8 PATCH 1/3] NETFILTER added flags to ipv6_find_hdr() Date: Fri, 27 Jan 2012 15:41:41 +0100 Message-ID: <1327675303-9059-2-git-send-email-hans.schillstrom@ericsson.com> References: <1327675303-9059-1-git-send-email-hans.schillstrom@ericsson.com> Mime-Version: 1.0 Content-Type: text/plain Cc: , Hans Schillstrom To: , , , , Return-path: Received: from mailgw10.se.ericsson.net ([193.180.251.61]:48920 "EHLO mailgw10.se.ericsson.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755091Ab2A0Olq (ORCPT ); Fri, 27 Jan 2012 09:41:46 -0500 In-Reply-To: <1327675303-9059-1-git-send-email-hans.schillstrom@ericsson.com> Sender: netdev-owner@vger.kernel.org List-ID: Two new flags to ipv6_find_hdr, One that tells us that this is a fragment. One that stops at AH if any i.e. treat it like a transport header. i.e. make handling of ESP and AH the same. Param offset can now point to an inner icmp ipv5 header. Version 3: offset param into ipv6_find_hdr set to zero. Version 2: wrapper removed and changes made at every call. Signed-off-by: Hans Schillstrom --- include/linux/netfilter_ipv6/ip6_tables.h | 8 +++++- net/ipv6/netfilter/ip6_tables.c | 35 ++++++++++++++++++++++++---- 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 f549adc..e1ad013 100644 --- a/include/linux/netfilter_ipv6/ip6_tables.h +++ b/include/linux/netfilter_ipv6/ip6_tables.h @@ -288,9 +288,15 @@ extern unsigned int ip6t_do_table(struct sk_buff *skb, /* Check for an extension */ extern int ip6t_ext_hdr(u8 nexthdr); +enum { + IP6T_FH_FRAG, + IP6T_FH_AUTH, + IP6T_FH_F_FRAG = 1 << IP6T_FH_FRAG, + IP6T_FH_F_AUTH = 1 << IP6T_FH_AUTH, +}; /* 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 94874b0..9dab6a8 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -146,7 +146,7 @@ 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; @@ -375,6 +375,7 @@ 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: @@ -2290,6 +2291,8 @@ static void __exit ip6_tables_fini(void) * find the offset to specified header or the protocol number of last header * if target < 0. "last header" is transport protocol header, ESP, or * "No next header". + * Note, *offset is used as input param. an if != 0 + * it must be an offset to an inner ipv6 header ex. icmp error * * If target header is found, its offset is set in *offset and return protocol * number. Otherwise, return -1. @@ -2302,17 +2305,34 @@ static void __exit ip6_tables_fini(void) * *offset is meaningless and fragment offset is stored in *fragoff if fragoff * isn't NULL. * + * if flags != NULL AND + * it's a fragment the frag flag "IP6T_FH_F_FRAG" will be set + * it's an AH header and IP6T_FH_F_AUTH is set and target < 0 + * stop at AH (i.e. treat is as a transport 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; @@ -2329,6 +2349,9 @@ 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), @@ -2349,9 +2372,11 @@ 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; -- 1.7.2.3