diff options
| author | Jan Engelhardt <jengelh@medozas.de> | 2010-01-04 16:28:38 +0100 |
|---|---|---|
| committer | Patrick McHardy <kaber@trash.net> | 2010-01-04 16:28:38 +0100 |
| commit | 294188ae32f984a072c64c959354b2f6f52f80a7 (patch) | |
| tree | 87e15911eebc0ef54375afc01aef3fd5efadd9c7 /net/netfilter/xt_recent.c | |
| parent | 5191d50192ec1281e51cbcb5248cb2667ff4d896 (diff) | |
netfilter: xtables: obtain random bytes earlier, in checkentry
We can initialize the random hash bytes on checkentry. This is
preferable since it is outside the hot path.
Reference: http://bugzilla.netfilter.org/show_bug.cgi?id=621
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'net/netfilter/xt_recent.c')
| -rw-r--r-- | net/netfilter/xt_recent.c | 20 |
1 files changed, 8 insertions, 12 deletions
diff --git a/net/netfilter/xt_recent.c b/net/netfilter/xt_recent.c index fc70a49c0afd..768d01ff1fea 100644 --- a/net/netfilter/xt_recent.c +++ b/net/netfilter/xt_recent.c @@ -90,25 +90,17 @@ static struct proc_dir_entry *recent_proc_dir; static const struct file_operations recent_old_fops, recent_mt_fops; #endif -static u_int32_t hash_rnd; -static bool hash_rnd_initted; +static u_int32_t hash_rnd __read_mostly; +static bool hash_rnd_inited __read_mostly; -static unsigned int recent_entry_hash4(const union nf_inet_addr *addr) +static inline unsigned int recent_entry_hash4(const union nf_inet_addr *addr) { - if (!hash_rnd_initted) { - get_random_bytes(&hash_rnd, sizeof(hash_rnd)); - hash_rnd_initted = true; - } return jhash_1word((__force u32)addr->ip, hash_rnd) & (ip_list_hash_size - 1); } -static unsigned int recent_entry_hash6(const union nf_inet_addr *addr) +static inline unsigned int recent_entry_hash6(const union nf_inet_addr *addr) { - if (!hash_rnd_initted) { - get_random_bytes(&hash_rnd, sizeof(hash_rnd)); - hash_rnd_initted = true; - } return jhash2((u32 *)addr->ip6, ARRAY_SIZE(addr->ip6), hash_rnd) & (ip_list_hash_size - 1); } @@ -287,6 +279,10 @@ static bool recent_mt_check(const struct xt_mtchk_param *par) unsigned i; bool ret = false; + if (unlikely(!hash_rnd_inited)) { + get_random_bytes(&hash_rnd, sizeof(hash_rnd)); + hash_rnd_inited = true; + } if (hweight8(info->check_set & (XT_RECENT_SET | XT_RECENT_REMOVE | XT_RECENT_CHECK | XT_RECENT_UPDATE)) != 1) |