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| author | Jan Engelhardt <jengelh@medozas.de> | 2009-07-09 23:00:19 +0200 |
|---|---|---|
| committer | Jan Engelhardt <jengelh@medozas.de> | 2009-08-10 13:35:27 +0200 |
| commit | 47901dc2c4a3f1f9af453486a005d31fe9b393f0 (patch) | |
| tree | 12bcbe4b7add3cc9beff300165ac4d962015ad15 | |
| parent | e5afbba1869a5d9509c61f8962be9bdebf95f7d3 (diff) | |
| download | linux-47901dc2c4a3f1f9af453486a005d31fe9b393f0.tar.gz linux-47901dc2c4a3f1f9af453486a005d31fe9b393f0.tar.bz2 linux-47901dc2c4a3f1f9af453486a005d31fe9b393f0.zip | |
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.c | 10 | ||||
| -rw-r--r-- | net/ipv4/netfilter/ip_tables.c | 11 | ||||
| -rw-r--r-- | net/ipv6/netfilter/ip6_tables.c | 11 |
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) || \ |