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authorJan Engelhardt <jengelh@medozas.de>2009-07-09 23:00:19 +0200
committerJan Engelhardt <jengelh@medozas.de>2009-08-10 13:35:27 +0200
commit47901dc2c4a3f1f9af453486a005d31fe9b393f0 (patch)
tree12bcbe4b7add3cc9beff300165ac4d962015ad15
parente5afbba1869a5d9509c61f8962be9bdebf95f7d3 (diff)
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netfilter: xtables: use memcmp in unconditional check
Instead of inspecting each u32/char open-coded, clean up and make use of memcmp. On some arches, memcmp is implemented as assembly or GCC's __builtin_memcmp which can possibly take advantages of known alignment. Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
-rw-r--r--net/ipv4/netfilter/arp_tables.c10
-rw-r--r--net/ipv4/netfilter/ip_tables.c11
-rw-r--r--net/ipv6/netfilter/ip6_tables.c11
3 files changed, 9 insertions, 23 deletions
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 7505dff4ffdf..b9f7243f4220 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -341,15 +341,11 @@ unsigned int arpt_do_table(struct sk_buff *skb,
}
/* All zeroes == unconditional rule. */
-static inline int unconditional(const struct arpt_arp *arp)
+static inline bool unconditional(const struct arpt_arp *arp)
{
- unsigned int i;
-
- for (i = 0; i < sizeof(*arp)/sizeof(__u32); i++)
- if (((__u32 *)arp)[i])
- return 0;
+ static const struct arpt_arp uncond;
- return 1;
+ return memcmp(arp, &uncond, sizeof(uncond)) == 0;
}
/* Figures out from what hook each rule can be called: returns 0 if
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 3856aa3f231e..3431a771ff1f 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -190,16 +190,11 @@ get_entry(void *base, unsigned int offset)
/* All zeroes == unconditional rule. */
/* Mildly perf critical (only if packet tracing is on) */
-static inline int
-unconditional(const struct ipt_ip *ip)
+static inline bool unconditional(const struct ipt_ip *ip)
{
- unsigned int i;
+ static const struct ipt_ip uncond;
- for (i = 0; i < sizeof(*ip)/sizeof(__u32); i++)
- if (((__u32 *)ip)[i])
- return 0;
-
- return 1;
+ return memcmp(ip, &uncond, sizeof(uncond)) == 0;
#undef FWINV
}
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index ced1f2c0cb65..1389ad904bc3 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -222,16 +222,11 @@ get_entry(void *base, unsigned int offset)
/* All zeroes == unconditional rule. */
/* Mildly perf critical (only if packet tracing is on) */
-static inline int
-unconditional(const struct ip6t_ip6 *ipv6)
+static inline bool unconditional(const struct ip6t_ip6 *ipv6)
{
- unsigned int i;
-
- for (i = 0; i < sizeof(*ipv6); i++)
- if (((char *)ipv6)[i])
- break;
+ static const struct ip6t_ip6 uncond;
- return (i == sizeof(*ipv6));
+ return memcmp(ipv6, &uncond, sizeof(uncond)) == 0;
}
#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
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