diff options
Diffstat (limited to 'net/netfilter/xt_physdev.c')
-rw-r--r-- | net/netfilter/xt_physdev.c | 37 |
1 files changed, 23 insertions, 14 deletions
diff --git a/net/netfilter/xt_physdev.c b/net/netfilter/xt_physdev.c index 1bcdfc12cf59..44a234ef4439 100644 --- a/net/netfilter/xt_physdev.c +++ b/net/netfilter/xt_physdev.c @@ -20,13 +20,30 @@ MODULE_DESCRIPTION("Xtables: Bridge physical device match"); MODULE_ALIAS("ipt_physdev"); MODULE_ALIAS("ip6t_physdev"); +static unsigned long ifname_compare(const char *_a, const char *_b, const 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; +} + static bool physdev_mt(const struct sk_buff *skb, const struct xt_match_param *par) { - int i; - static const char nulldevname[IFNAMSIZ]; + static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long)))); const struct xt_physdev_info *info = par->matchinfo; - bool ret; + unsigned long ret; const char *indev, *outdev; const struct nf_bridge_info *nf_bridge; @@ -68,11 +85,7 @@ physdev_mt(const struct sk_buff *skb, const struct xt_match_param *par) if (!(info->bitmask & XT_PHYSDEV_OP_IN)) goto match_outdev; indev = nf_bridge->physindev ? nf_bridge->physindev->name : nulldevname; - for (i = 0, ret = false; i < IFNAMSIZ/sizeof(unsigned int); i++) { - ret |= (((const unsigned int *)indev)[i] - ^ ((const unsigned int *)info->physindev)[i]) - & ((const unsigned int *)info->in_mask)[i]; - } + ret = ifname_compare(indev, info->physindev, info->in_mask); if (!ret ^ !(info->invert & XT_PHYSDEV_OP_IN)) return false; @@ -82,13 +95,9 @@ match_outdev: return true; outdev = nf_bridge->physoutdev ? nf_bridge->physoutdev->name : nulldevname; - for (i = 0, ret = false; i < IFNAMSIZ/sizeof(unsigned int); i++) { - ret |= (((const unsigned int *)outdev)[i] - ^ ((const unsigned int *)info->physoutdev)[i]) - & ((const unsigned int *)info->out_mask)[i]; - } + ret = ifname_compare(outdev, info->physoutdev, info->out_mask); - return ret ^ !(info->invert & XT_PHYSDEV_OP_OUT); + return (!!ret ^ !(info->invert & XT_PHYSDEV_OP_OUT)); } static bool physdev_mt_check(const struct xt_mtchk_param *par) |