diff options
Diffstat (limited to 'net/netfilter/xt_hashlimit.c')
| -rw-r--r-- | net/netfilter/xt_hashlimit.c | 54 |
1 files changed, 46 insertions, 8 deletions
diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c index 26a668a84aa..a9d7af953ce 100644 --- a/net/netfilter/xt_hashlimit.c +++ b/net/netfilter/xt_hashlimit.c @@ -157,11 +157,22 @@ dsthash_find(const struct xt_hashlimit_htable *ht, /* allocate dsthash_ent, initialize dst, put in htable and lock it */ static struct dsthash_ent * dsthash_alloc_init(struct xt_hashlimit_htable *ht, - const struct dsthash_dst *dst) + const struct dsthash_dst *dst, bool *race) { struct dsthash_ent *ent; spin_lock(&ht->lock); + + /* Two or more packets may race to create the same entry in the + * hashtable, double check if this packet lost race. + */ + ent = dsthash_find(ht, dst); + if (ent != NULL) { + spin_unlock(&ht->lock); + *race = true; + return ent; + } + /* initialize hash with random val at the time we allocate * the first hashtable entry */ if (unlikely(!ht->rnd_initialized)) { @@ -318,7 +329,10 @@ static void htable_destroy(struct xt_hashlimit_htable *hinfo) parent = hashlimit_net->ipt_hashlimit; else parent = hashlimit_net->ip6t_hashlimit; - remove_proc_entry(hinfo->pde->name, parent); + + if(parent != NULL) + remove_proc_entry(hinfo->pde->name, parent); + htable_selective_cleanup(hinfo, select_all); vfree(hinfo); } @@ -585,6 +599,7 @@ hashlimit_mt(const struct sk_buff *skb, struct xt_action_param *par) unsigned long now = jiffies; struct dsthash_ent *dh; struct dsthash_dst dst; + bool race = false; u32 cost; if (hashlimit_init_dst(hinfo, &dst, skb, par->thoff) < 0) @@ -593,13 +608,18 @@ hashlimit_mt(const struct sk_buff *skb, struct xt_action_param *par) rcu_read_lock_bh(); dh = dsthash_find(hinfo, &dst); if (dh == NULL) { - dh = dsthash_alloc_init(hinfo, &dst); + dh = dsthash_alloc_init(hinfo, &dst, &race); if (dh == NULL) { rcu_read_unlock_bh(); goto hotdrop; + } else if (race) { + /* Already got an entry, update expiration timeout */ + dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire); + rateinfo_recalc(dh, now, hinfo->cfg.mode); + } else { + dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire); + rateinfo_init(dh, hinfo); } - dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire); - rateinfo_init(dh, hinfo); } else { /* update expiration timeout */ dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire); @@ -856,6 +876,27 @@ static int __net_init hashlimit_proc_net_init(struct net *net) static void __net_exit hashlimit_proc_net_exit(struct net *net) { + struct xt_hashlimit_htable *hinfo; + struct hlist_node *pos; + struct proc_dir_entry *pde; + struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); + + /* recent_net_exit() is called before recent_mt_destroy(). Make sure + * that the parent xt_recent proc entry is is empty before trying to + * remove it. + */ + mutex_lock(&hashlimit_mutex); + pde = hashlimit_net->ipt_hashlimit; + if (pde == NULL) + pde = hashlimit_net->ip6t_hashlimit; + + hlist_for_each_entry(hinfo, pos, &hashlimit_net->htables, node) + remove_proc_entry(hinfo->pde->name, pde); + + hashlimit_net->ipt_hashlimit = NULL; + hashlimit_net->ip6t_hashlimit = NULL; + mutex_unlock(&hashlimit_mutex); + proc_net_remove(net, "ipt_hashlimit"); #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) proc_net_remove(net, "ip6t_hashlimit"); @@ -872,9 +913,6 @@ static int __net_init hashlimit_net_init(struct net *net) static void __net_exit hashlimit_net_exit(struct net *net) { - struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); - - BUG_ON(!hlist_empty(&hashlimit_net->htables)); hashlimit_proc_net_exit(net); } |