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Message-ID: <1326448338-13416-2-git-send-email-hans.schillstrom@ericsson.com>
Date: Fri, 13 Jan 2012 10:52:16 +0100
From: Hans Schillstrom <hans.schillstrom@...csson.com>
To: <kaber@...sh.net>, <pablo@...filter.org>, <jengelh@...ozas.de>,
<netfilter-devel@...r.kernel.org>, <netdev@...r.kernel.org>
CC: <hans@...illstrom.com>,
Hans Schillstrom <hans.schillstrom@...csson.com>
Subject: [PATCH 1/3] NETFILTER added flags to ipv6_find_hdr()
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 <hans.schillstrom@...csson.com>
---
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 <net/compat.h>
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
--
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