--- a/include/linux/netfilter/xt_recent.h +++ b/include/linux/netfilter/xt_recent.h @@ -9,6 +9,7 @@ enum { XT_RECENT_UPDATE = 1 << 2, XT_RECENT_REMOVE = 1 << 3, XT_RECENT_TTL = 1 << 4, + XT_RECENT_REAP = 1 << 5, XT_RECENT_SOURCE = 0, XT_RECENT_DEST = 1, @@ -16,6 +17,9 @@ enum { XT_RECENT_NAME_LEN = 200, }; +/* Only allowed with --rcheck and --update */ +#define XT_RECENT_MODIFIERS (XT_RECENT_TTL|XT_RECENT_REAP) + struct xt_recent_mtinfo { __u32 seconds; __u32 hit_count; --- a/net/netfilter/xt_recent.c +++ b/net/netfilter/xt_recent.c @@ -142,6 +142,25 @@ static void recent_entry_remove(struct r t->entries--; } +/* + * Drop entries with timestamps older then 'time'. + */ +static void recent_entry_reap(struct recent_table *t, unsigned long time) +{ + struct recent_entry *e; + + /* + * The head of the LRU list is always the oldest entry. + */ + e = list_entry(t->lru_list.next, struct recent_entry, lru_list); + + /* + * The last time stamp is the most recent. + */ + if (time_after(time, e->stamps[e->index-1])) + recent_entry_remove(t, e); +} + static struct recent_entry * recent_entry_init(struct recent_table *t, const union nf_inet_addr *addr, u_int16_t family, u_int8_t ttl) @@ -265,6 +284,10 @@ recent_mt(const struct sk_buff *skb, con break; } } + + /* info->seconds must be non-zero */ + if (info->check_set & XT_RECENT_REAP) + recent_entry_reap(t, time); } if (info->check_set & XT_RECENT_SET || @@ -292,7 +315,10 @@ static bool recent_mt_check(const struct XT_RECENT_CHECK | XT_RECENT_UPDATE)) != 1) return false; if ((info->check_set & (XT_RECENT_SET | XT_RECENT_REMOVE)) && - (info->seconds || info->hit_count)) + (info->seconds || info->hit_count || + (info->check_set & XT_RECENT_MODIFIERS))) + return false; + if ((info->check_set & XT_RECENT_REAP) && !info->seconds) return false; if (info->hit_count > ip_pkt_list_tot) return false;