2  *		INETPEER - A storage for permanent information about peers
28  *  We keep one entry for each peer IP address.  The nodes contains long-living
33  *  time has been passed since its last use.  The less-recently-used entry can
34  *  also be removed if the pool is overloaded i.e. if the total amount of
35  *  entries is greater-or-equal than the threshold.
59 	bp->rb_root = RB_ROOT;  in inet_peer_base_init()
60 	seqlock_init(&bp->lock);  in inet_peer_base_init()
61 	bp->total = 0;  in inet_peer_base_init()
90 /* Called with rcu_read_lock() or base->lock held */
103 	pp = &base->rb_root.rb_node;  in lookup()
113 		cmp = inetpeer_addr_cmp(daddr, &p->daddr);  in lookup()
116 			if (READ_ONCE(p->dtime) != now)  in lookup()
117 				WRITE_ONCE(p->dtime, now);  in lookup()
123 		} else if (unlikely(read_seqretry(&base->lock, seq))) {  in lookup()
126 		if (cmp == -1)  in lookup()
127 			pp = &next->rb_left;  in lookup()
129 			pp = &next->rb_right;  in lookup()
155 	if (base->total >= peer_threshold)  in inet_peer_gc()
158 		ttl = peer_maxttl - (peer_maxttl - peer_minttl) / HZ *  in inet_peer_gc()
159 			base->total / peer_threshold * HZ;  in inet_peer_gc()
163 		delta = (__u32)jiffies - READ_ONCE(p->dtime);  in inet_peer_gc()
165 		if (delta < ttl || !refcount_dec_if_one(&p->refcnt))  in inet_peer_gc()
171 			rb_erase(&p->rb_node, &base->rb_root);  in inet_peer_gc()
172 			base->total--;  in inet_peer_gc()
173 			call_rcu(&p->rcu, inetpeer_free_rcu);  in inet_peer_gc()
189 	seq = read_seqbegin(&base->lock);  in inet_getpeer()
199 	write_seqlock_bh(&base->lock);  in inet_getpeer()
206 			p->daddr = *daddr;  in inet_getpeer()
207 			p->dtime = (__u32)jiffies;  in inet_getpeer()
208 			refcount_set(&p->refcnt, 1);  in inet_getpeer()
209 			atomic_set(&p->rid, 0);  in inet_getpeer()
210 			p->metrics[RTAX_LOCK-1] = INETPEER_METRICS_NEW;  in inet_getpeer()
211 			p->rate_tokens = 0;  in inet_getpeer()
212 			p->n_redirects = 0;  in inet_getpeer()
216 			p->rate_last = jiffies - 60*HZ;  in inet_getpeer()
218 			rb_link_node(&p->rb_node, parent, pp);  in inet_getpeer()
219 			rb_insert_color(&p->rb_node, &base->rb_root);  in inet_getpeer()
220 			base->total++;  in inet_getpeer()
225 	write_sequnlock_bh(&base->lock);  in inet_getpeer()
233 	if (refcount_dec_and_test(&p->refcnt))  in inet_putpeer()
234 		call_rcu(&p->rcu, inetpeer_free_rcu);  in inet_putpeer()
246  *	for one "ip object" is shared - and these ICMPs are twice limited:
255 bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout)  in inet_peer_xrlim_allow()  argument
263 	token = peer->rate_tokens;  in inet_peer_xrlim_allow()
265 	token += now - peer->rate_last;  in inet_peer_xrlim_allow()
266 	peer->rate_last = now;  in inet_peer_xrlim_allow()
267 	if (token > XRLIM_BURST_FACTOR * timeout)  in inet_peer_xrlim_allow()
268 		token = XRLIM_BURST_FACTOR * timeout;  in inet_peer_xrlim_allow()
269 	if (token >= timeout) {  in inet_peer_xrlim_allow()
270 		token -= timeout;  in inet_peer_xrlim_allow()
273 	peer->rate_tokens = token;  in inet_peer_xrlim_allow()
280 	struct rb_node *p = rb_first(&base->rb_root);  in inetpeer_invalidate_tree()
286 		rb_erase(&peer->rb_node, &base->rb_root);  in inetpeer_invalidate_tree()
291 	base->total = 0;  in inetpeer_invalidate_tree()