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| author | YOSHIFUJI Hideaki / 吉藤英明 <yoshfuji@linux-ipv6.org> | 2013-01-26 08:37:48 +0000 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2013-02-07 18:37:41 +0100 |
| commit | f5271fff56c76e92fde122bcc02f102e99da5c8a (patch) | |
| tree | 88e0f58ea00fbc4f8652f92d915b40403aa38f3e /net/ipv6 | |
| parent | 4b47bc9a9e69141ed3a854c57601f548e82c78ba (diff) | |
| download | linux-f5271fff56c76e92fde122bcc02f102e99da5c8a.tar.bz2 | |
netfilter: ip6t_NPT: Fix adjustment calculation
Cast __wsum from/to __sum16 is wrong. Instead, apply appropriate
conversion function: csum_unfold() or csum_fold().
[ The original patch has been modified to undo the final ~ that
csum_fold returns. We only need to fold the 32-bit word that
results from the checksum calculation into a 16-bit to ensure
that the original subnet is restored appropriately. Spotted by
Ulrich Weber. ]
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/ipv6')
| -rw-r--r-- | net/ipv6/netfilter/ip6t_NPT.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/net/ipv6/netfilter/ip6t_NPT.c b/net/ipv6/netfilter/ip6t_NPT.c index 7302b0b7b642..68788c84aee7 100644 --- a/net/ipv6/netfilter/ip6t_NPT.c +++ b/net/ipv6/netfilter/ip6t_NPT.c @@ -30,7 +30,7 @@ static int ip6t_npt_checkentry(const struct xt_tgchk_param *par) (__force __wsum)npt->dst_pfx.in6.s6_addr16[i]); } - npt->adjustment = (__force __sum16) csum_sub(src_sum, dst_sum); + npt->adjustment = ~csum_fold(csum_sub(src_sum, dst_sum)); return 0; } @@ -66,8 +66,8 @@ static bool ip6t_npt_map_pfx(const struct ip6t_npt_tginfo *npt, return false; } - sum = (__force __sum16) csum_add((__force __wsum)addr->s6_addr16[idx], - npt->adjustment); + sum = ~csum_fold(csum_add(csum_unfold((__force __sum16)addr->s6_addr16[idx]), + csum_unfold(npt->adjustment))); if (sum == CSUM_MANGLED_0) sum = 0; *(__force __sum16 *)&addr->s6_addr16[idx] = sum; |