diff options
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/xt_hashlimit.c | 25 |
1 files changed, 9 insertions, 16 deletions
diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c index 10063408141d..84ad5ab34558 100644 --- a/net/netfilter/xt_hashlimit.c +++ b/net/netfilter/xt_hashlimit.c @@ -463,23 +463,16 @@ static u32 xt_hashlimit_len_to_chunks(u32 len) /* Precision saver. */ static u64 user2credits(u64 user, int revision) { - if (revision == 1) { - /* If multiplying would overflow... */ - if (user > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY_v1)) - /* Divide first. */ - return div64_u64(user, XT_HASHLIMIT_SCALE) - * HZ * CREDITS_PER_JIFFY_v1; - - return div64_u64(user * HZ * CREDITS_PER_JIFFY_v1, - XT_HASHLIMIT_SCALE); - } else { - if (user > 0xFFFFFFFFFFFFFFFFULL / (HZ*CREDITS_PER_JIFFY)) - return div64_u64(user, XT_HASHLIMIT_SCALE_v2) - * HZ * CREDITS_PER_JIFFY; + u64 scale = (revision == 1) ? + XT_HASHLIMIT_SCALE : XT_HASHLIMIT_SCALE_v2; + u64 cpj = (revision == 1) ? + CREDITS_PER_JIFFY_v1 : CREDITS_PER_JIFFY; - return div64_u64(user * HZ * CREDITS_PER_JIFFY, - XT_HASHLIMIT_SCALE_v2); - } + /* Avoid overflow: divide the constant operands first */ + if (scale >= HZ * cpj) + return div64_u64(user, div64_u64(scale, HZ * cpj)); + + return user * div64_u64(HZ * cpj, scale); } static u32 user2credits_byte(u32 user) |