: Fix multiple bugs in ipv6header match

This patch fixes an invalid cast and unlogical inverse match in the ipv6header match.

# This is a BitKeeper generated diff -Nru style patch. #
# ChangeSet
# 2004/11/04 03:12:42+01:00 [email protected]
# [NETFILTER]: Fix multiple bugs in ipv6header match
#
# This patch fixes following bugs in ip6t_ipv6header.c
#
# - The cast of the pointer to the next IPv6 extension header is wrong.
# - The logical operation is wrong. These fixes intends
#
# - soft mode without invert flag "!"
# match if the packet contains all of the specified headers.
#

#   	- soft mode with invert flag "!"
#   		match if the packet DOESN'T contain all of the specified
#   		headers.
#   
#   	- strict mode without invert flag "!"
#   		match if the packet contains JUST ONLY the specified headers.
#   		if the packet doesn't contain some specified headers or
#   		contains unspecified headers, the packet doesn't match with
#   		rule.
#   
#   	- strict mode with invert flag "!"
#   		NOT MATCH if the packet contains JUST ONLY the specified
#   		headers. Otherwise, match. So, if the packet contains some
#   		specified headers and DOESN'T contain other specified headers,
#   		the packet MATCHES with rule.

#
# Signed-off-by: Yasuyuki KOZAKAI <[email protected]>
# Signed-off-by: Patrick McHardy <[email protected]>
#

# net/ipv6/netfilter/ip6t_ipv6header.c
#   2004/11/04 03:12:35+01:00 [email protected] +16 -5
#   [NETFILTER]: Fix multiple bugs in ipv6header match
#   
#   This patch fixes following bugs in ip6t_ipv6header.c
#   
#   - The cast of the pointer to the next IPv6 extension header is wrong.
#   - The logical operation is wrong. These fixes intends
#   
#   	- soft mode without invert flag "!"
#   		match if the packet contains all of the specified headers.
#   
#   	- soft mode with invert flag "!"
#   		match if the packet DOESN'T contain all of the specified
#   		headers.
#   
#   	- strict mode without invert flag "!"
#   		match if the packet contains JUST ONLY the specified headers.
#   		if the packet doesn't contain some specified headers or
#   		contains unspecified headers, the packet doesn't match with
#   		rule.
#   
#   	- strict mode with invert flag "!"
#   		NOT MATCH if the packet contains JUST ONLY the specified
#   		headers. Otherwise, match. So, if the packet contains some
#   		specified headers and DOESN'T contain other specified headers,
#   		the packet MATCHES with rule.
#   
#   Signed-off-by: Yasuyuki KOZAKAI <[email protected]>
#   Signed-off-by: Patrick McHardy <[email protected]>
# 
diff -Nru a/net/ipv6/netfilter/ip6t_ipv6header.c b/net/ipv6/netfilter/ip6t_ipv6header.c
--- a/net/ipv6/netfilter/ip6t_ipv6header.c	2004-11-15 22:06:09 +01:00
+++ b/net/ipv6/netfilter/ip6t_ipv6header.c	2004-11-15 22:06:09 +01:00
@@ -68,7 +68,7 @@
 			break;
 		}

- hdr=(struct ipv6_opt_hdr *)skb->data+ptr;
+ hdr=(struct ipv6_opt_hdr *)(skb->data+ptr);

/* Calculate the header length */

                 if (nexthdr == NEXTHDR_FRAGMENT) {

@@ -111,10 +111,14 @@
temp |= MASK_PROTO;

if (info->modeflag)
- return (!( (temp & info->matchflags)
- ^ info->matchflags) ^ info->invflags);
- else
- return (!( temp ^ info->matchflags) ^ info->invflags);
+ return !((temp ^ info->matchflags ^ info->invflags)
+ & info->matchflags);
+ else {
+ if (info->invflags)
+ return temp != info->matchflags;
+ else
+ return temp == info->matchflags;
+ }
}

static int
@@ -124,9 +128,16 @@
unsigned int matchsize,
unsigned int hook_mask)
{
+ const struct ip6t_ipv6header_info *info = matchinfo;
+
/* Check for obvious errors */
/* This match is valid in all hooks! */
if (matchsize != IP6T_ALIGN(sizeof(struct ip6t_ipv6header_info)))
+ return 0;
+
+ /* invflags is 0 or 0xff in hard mode */
+ if ((!info->modeflag) && info->invflags != 0x00
+ && info->invflags != 0xFF)
return 0;

return 1;