diff options
Diffstat (limited to 'net/ipv6')
| -rw-r--r-- | net/ipv6/netfilter/ip6_tables.c | 33 |
1 files changed, 21 insertions, 12 deletions
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c index a33485dc81c..d64594b6c06 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -89,6 +89,25 @@ ip6t_ext_hdr(u8 nexthdr) (nexthdr == IPPROTO_DSTOPTS) ); } +static unsigned long ifname_compare(const char *_a, const char *_b, + const unsigned char *_mask) +{ + const unsigned long *a = (const unsigned long *)_a; + const unsigned long *b = (const unsigned long *)_b; + const unsigned long *mask = (const unsigned long *)_mask; + unsigned long ret; + + ret = (a[0] ^ b[0]) & mask[0]; + if (IFNAMSIZ > sizeof(unsigned long)) + ret |= (a[1] ^ b[1]) & mask[1]; + if (IFNAMSIZ > 2 * sizeof(unsigned long)) + ret |= (a[2] ^ b[2]) & mask[2]; + if (IFNAMSIZ > 3 * sizeof(unsigned long)) + ret |= (a[3] ^ b[3]) & mask[3]; + BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long)); + return ret; +} + /* Returns whether matches rule or not. */ /* Performance critical - called for every packet */ static inline bool @@ -99,7 +118,6 @@ ip6_packet_match(const struct sk_buff *skb, unsigned int *protoff, int *fragoff, bool *hotdrop) { - size_t i; unsigned long ret; const struct ipv6hdr *ipv6 = ipv6_hdr(skb); @@ -120,12 +138,7 @@ ip6_packet_match(const struct sk_buff *skb, return false; } - /* Look for ifname matches; this should unroll nicely. */ - for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) { - ret |= (((const unsigned long *)indev)[i] - ^ ((const unsigned long *)ip6info->iniface)[i]) - & ((const unsigned long *)ip6info->iniface_mask)[i]; - } + ret = ifname_compare(indev, ip6info->iniface, ip6info->iniface_mask); if (FWINV(ret != 0, IP6T_INV_VIA_IN)) { dprintf("VIA in mismatch (%s vs %s).%s\n", @@ -134,11 +147,7 @@ ip6_packet_match(const struct sk_buff *skb, return false; } - for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) { - ret |= (((const unsigned long *)outdev)[i] - ^ ((const unsigned long *)ip6info->outiface)[i]) - & ((const unsigned long *)ip6info->outiface_mask)[i]; - } + ret = ifname_compare(outdev, ip6info->outiface, ip6info->outiface_mask); if (FWINV(ret != 0, IP6T_INV_VIA_OUT)) { dprintf("VIA out mismatch (%s vs %s).%s\n", |