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()
82 	 * myself.  --SAW  in inet_initpeers()
97 /* Called with rcu_read_lock() or base->lock held */
109 	pp = &base->rb_root.rb_node;  in lookup()
119 		cmp = inetpeer_addr_cmp(daddr, &p->daddr);  in lookup()
121 			if (!refcount_inc_not_zero(&p->refcnt))  in lookup()
128 		} else if (unlikely(read_seqretry(&base->lock, seq))) {  in lookup()
131 		if (cmp == -1)  in lookup()
132 			pp = &next->rb_left;  in lookup()
134 			pp = &next->rb_right;  in lookup()
160 	if (base->total >= peer_threshold)  in inet_peer_gc()
163 		ttl = peer_maxttl - (peer_maxttl - peer_minttl) / HZ *  in inet_peer_gc()
164 			base->total / peer_threshold * HZ;  in inet_peer_gc()
171 		delta = (__u32)jiffies - READ_ONCE(p->dtime);  in inet_peer_gc()
173 		if (delta < ttl || !refcount_dec_if_one(&p->refcnt))  in inet_peer_gc()
179 			rb_erase(&p->rb_node, &base->rb_root);  in inet_peer_gc()
180 			base->total--;  in inet_peer_gc()
181 			call_rcu(&p->rcu, inetpeer_free_rcu);  in inet_peer_gc()
199 	seq = read_seqbegin(&base->lock);  in inet_getpeer()
201 	invalidated = read_seqretry(&base->lock, seq);  in inet_getpeer()
215 	write_seqlock_bh(&base->lock);  in inet_getpeer()
222 			p->daddr = *daddr;  in inet_getpeer()
223 			p->dtime = (__u32)jiffies;  in inet_getpeer()
224 			refcount_set(&p->refcnt, 2);  in inet_getpeer()
225 			atomic_set(&p->rid, 0);  in inet_getpeer()
226 			p->metrics[RTAX_LOCK-1] = INETPEER_METRICS_NEW;  in inet_getpeer()
227 			p->rate_tokens = 0;  in inet_getpeer()
228 			p->n_redirects = 0;  in inet_getpeer()
232 			p->rate_last = jiffies - 60*HZ;  in inet_getpeer()
234 			rb_link_node(&p->rb_node, parent, pp);  in inet_getpeer()
235 			rb_insert_color(&p->rb_node, &base->rb_root);  in inet_getpeer()
236 			base->total++;  in inet_getpeer()
241 	write_sequnlock_bh(&base->lock);  in inet_getpeer()
252 	WRITE_ONCE(p->dtime, (__u32)jiffies);  in inet_putpeer()
254 	if (refcount_dec_and_test(&p->refcnt))  in inet_putpeer()
255 		call_rcu(&p->rcu, inetpeer_free_rcu);  in inet_putpeer()
268  *	for one "ip object" is shared - and these ICMPs are twice limited:
277 bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout)  in inet_peer_xrlim_allow()  argument
285 	token = peer->rate_tokens;  in inet_peer_xrlim_allow()
287 	token += now - peer->rate_last;  in inet_peer_xrlim_allow()
288 	peer->rate_last = now;  in inet_peer_xrlim_allow()
289 	if (token > XRLIM_BURST_FACTOR * timeout)  in inet_peer_xrlim_allow()
290 		token = XRLIM_BURST_FACTOR * timeout;  in inet_peer_xrlim_allow()
291 	if (token >= timeout) {  in inet_peer_xrlim_allow()
292 		token -= timeout;  in inet_peer_xrlim_allow()
295 	peer->rate_tokens = token;  in inet_peer_xrlim_allow()
302 	struct rb_node *p = rb_first(&base->rb_root);  in inetpeer_invalidate_tree()
308 		rb_erase(&peer->rb_node, &base->rb_root);  in inetpeer_invalidate_tree()
313 	base->total = 0;  in inetpeer_invalidate_tree()