From 429da4c0b1e59837ec946cdf0f04eb1899586923 Mon Sep 17 00:00:00 2001 From: Ulrich Weber Date: Wed, 2 Jan 2013 05:24:40 +0000 Subject: [PATCH] netfilter: ip6t_NPT: fix IPv6 NTP checksum calculation csum16_add() has a broken carry detection, should be: sum += sum < (__force u16)b; Instead of fixing csum16_add, remove the custom checksum functions and use the generic csum_add/csum_sub ones. Signed-off-by: Ulrich Weber Acked-by: Patrick McHardy Signed-off-by: Pablo Neira Ayuso --- net/ipv6/netfilter/ip6t_NPT.c | 33 +++++++-------------------------- 1 file changed, 7 insertions(+), 26 deletions(-) diff --git a/net/ipv6/netfilter/ip6t_NPT.c b/net/ipv6/netfilter/ip6t_NPT.c index e9486915eff6..7302b0b7b642 100644 --- a/net/ipv6/netfilter/ip6t_NPT.c +++ b/net/ipv6/netfilter/ip6t_NPT.c @@ -14,42 +14,23 @@ #include #include -static __sum16 csum16_complement(__sum16 a) -{ - return (__force __sum16)(0xffff - (__force u16)a); -} - -static __sum16 csum16_add(__sum16 a, __sum16 b) -{ - u16 sum; - - sum = (__force u16)a + (__force u16)b; - sum += (__force u16)a < (__force u16)b; - return (__force __sum16)sum; -} - -static __sum16 csum16_sub(__sum16 a, __sum16 b) -{ - return csum16_add(a, csum16_complement(b)); -} - static int ip6t_npt_checkentry(const struct xt_tgchk_param *par) { struct ip6t_npt_tginfo *npt = par->targinfo; - __sum16 src_sum = 0, dst_sum = 0; + __wsum src_sum = 0, dst_sum = 0; unsigned int i; if (npt->src_pfx_len > 64 || npt->dst_pfx_len > 64) return -EINVAL; for (i = 0; i < ARRAY_SIZE(npt->src_pfx.in6.s6_addr16); i++) { - src_sum = csum16_add(src_sum, - (__force __sum16)npt->src_pfx.in6.s6_addr16[i]); - dst_sum = csum16_add(dst_sum, - (__force __sum16)npt->dst_pfx.in6.s6_addr16[i]); + src_sum = csum_add(src_sum, + (__force __wsum)npt->src_pfx.in6.s6_addr16[i]); + dst_sum = csum_add(dst_sum, + (__force __wsum)npt->dst_pfx.in6.s6_addr16[i]); } - npt->adjustment = csum16_sub(src_sum, dst_sum); + npt->adjustment = (__force __sum16) csum_sub(src_sum, dst_sum); return 0; } @@ -85,7 +66,7 @@ static bool ip6t_npt_map_pfx(const struct ip6t_npt_tginfo *npt, return false; } - sum = csum16_add((__force __sum16)addr->s6_addr16[idx], + sum = (__force __sum16) csum_add((__force __wsum)addr->s6_addr16[idx], npt->adjustment); if (sum == CSUM_MANGLED_0) sum = 0; -- 2.20.1