From 1b9b70ea2ebaab26c3e4fed385dfab6fc16359ed Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Wed, 9 Apr 2008 15:14:18 -0700 Subject: [PATCH] [NETFILTER]: xt_hashlimit: fix mask calculation Shifts larger than the data type are undefined, don't try to shift an u32 by 32. Also remove some special-casing of bitmasks divisible by 32. Based on patch by Jan Engelhardt . Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- net/netfilter/xt_hashlimit.c | 23 +++++------------------ 1 file changed, 5 insertions(+), 18 deletions(-) diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c index dc29007c52cd..40d344b21453 100644 --- a/net/netfilter/xt_hashlimit.c +++ b/net/netfilter/xt_hashlimit.c @@ -466,38 +466,25 @@ static inline void rateinfo_recalc(struct dsthash_ent *dh, unsigned long now) static inline __be32 maskl(__be32 a, unsigned int l) { - return htonl(ntohl(a) & ~(~(u_int32_t)0 >> l)); + return l ? htonl(ntohl(a) & ~0 << (32 - l)) : 0; } #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE) static void hashlimit_ipv6_mask(__be32 *i, unsigned int p) { switch (p) { - case 0: - i[0] = i[1] = 0; - i[2] = i[3] = 0; - break; - case 1 ... 31: + case 0 ... 31: i[0] = maskl(i[0], p); i[1] = i[2] = i[3] = 0; break; - case 32: - i[1] = i[2] = i[3] = 0; - break; - case 33 ... 63: + case 32 ... 63: i[1] = maskl(i[1], p - 32); i[2] = i[3] = 0; break; - case 64: - i[2] = i[3] = 0; - break; - case 65 ... 95: + case 64 ... 95: i[2] = maskl(i[2], p - 64); i[3] = 0; - case 96: - i[3] = 0; - break; - case 97 ... 127: + case 96 ... 127: i[3] = maskl(i[3], p - 96); break; case 128: -- 2.20.1