Linux Audio

Check our new training course

Loading...
v6.2
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/* Peer event handling, typically ICMP messages.
  3 *
  4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
  5 * Written by David Howells (dhowells@redhat.com)
 
 
 
 
 
  6 */
  7
  8#include <linux/module.h>
  9#include <linux/net.h>
 10#include <linux/skbuff.h>
 11#include <linux/errqueue.h>
 12#include <linux/udp.h>
 13#include <linux/in.h>
 14#include <linux/in6.h>
 15#include <linux/icmp.h>
 16#include <net/sock.h>
 17#include <net/af_rxrpc.h>
 18#include <net/ip.h>
 19#include "ar-internal.h"
 20
 21static void rxrpc_store_error(struct rxrpc_peer *, struct sk_buff *);
 22static void rxrpc_distribute_error(struct rxrpc_peer *, struct sk_buff *,
 23				   enum rxrpc_call_completion, int);
 24
 25/*
 26 * Find the peer associated with a local error.
 27 */
 28static struct rxrpc_peer *rxrpc_lookup_peer_local_rcu(struct rxrpc_local *local,
 29						      const struct sk_buff *skb,
 30						      struct sockaddr_rxrpc *srx)
 31{
 32	struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
 33
 34	_enter("");
 35
 36	memset(srx, 0, sizeof(*srx));
 37	srx->transport_type = local->srx.transport_type;
 38	srx->transport_len = local->srx.transport_len;
 39	srx->transport.family = local->srx.transport.family;
 40
 41	/* Can we see an ICMP4 packet on an ICMP6 listening socket?  and vice
 42	 * versa?
 43	 */
 44	switch (srx->transport.family) {
 45	case AF_INET:
 46		srx->transport_len = sizeof(srx->transport.sin);
 47		srx->transport.family = AF_INET;
 48		srx->transport.sin.sin_port = serr->port;
 49		switch (serr->ee.ee_origin) {
 50		case SO_EE_ORIGIN_ICMP:
 
 51			memcpy(&srx->transport.sin.sin_addr,
 52			       skb_network_header(skb) + serr->addr_offset,
 53			       sizeof(struct in_addr));
 54			break;
 55		case SO_EE_ORIGIN_ICMP6:
 
 56			memcpy(&srx->transport.sin.sin_addr,
 57			       skb_network_header(skb) + serr->addr_offset + 12,
 58			       sizeof(struct in_addr));
 59			break;
 60		default:
 61			memcpy(&srx->transport.sin.sin_addr, &ip_hdr(skb)->saddr,
 62			       sizeof(struct in_addr));
 63			break;
 64		}
 65		break;
 66
 67#ifdef CONFIG_AF_RXRPC_IPV6
 68	case AF_INET6:
 
 69		switch (serr->ee.ee_origin) {
 70		case SO_EE_ORIGIN_ICMP6:
 71			srx->transport.sin6.sin6_port = serr->port;
 72			memcpy(&srx->transport.sin6.sin6_addr,
 73			       skb_network_header(skb) + serr->addr_offset,
 74			       sizeof(struct in6_addr));
 75			break;
 76		case SO_EE_ORIGIN_ICMP:
 77			srx->transport_len = sizeof(srx->transport.sin);
 78			srx->transport.family = AF_INET;
 79			srx->transport.sin.sin_port = serr->port;
 80			memcpy(&srx->transport.sin.sin_addr,
 
 81			       skb_network_header(skb) + serr->addr_offset,
 82			       sizeof(struct in_addr));
 83			break;
 84		default:
 85			memcpy(&srx->transport.sin6.sin6_addr,
 86			       &ipv6_hdr(skb)->saddr,
 87			       sizeof(struct in6_addr));
 88			break;
 89		}
 90		break;
 91#endif
 92
 93	default:
 94		BUG();
 95	}
 96
 97	return rxrpc_lookup_peer_rcu(local, srx);
 98}
 99
100/*
101 * Handle an MTU/fragmentation problem.
102 */
103static void rxrpc_adjust_mtu(struct rxrpc_peer *peer, unsigned int mtu)
104{
 
 
 
 
105	/* wind down the local interface MTU */
106	if (mtu > 0 && peer->if_mtu == 65535 && mtu < peer->if_mtu)
107		peer->if_mtu = mtu;
 
 
108
109	if (mtu == 0) {
110		/* they didn't give us a size, estimate one */
111		mtu = peer->if_mtu;
112		if (mtu > 1500) {
113			mtu >>= 1;
114			if (mtu < 1500)
115				mtu = 1500;
116		} else {
117			mtu -= 100;
118			if (mtu < peer->hdrsize)
119				mtu = peer->hdrsize + 4;
120		}
121	}
122
123	if (mtu < peer->mtu) {
124		spin_lock(&peer->lock);
125		peer->mtu = mtu;
126		peer->maxdata = peer->mtu - peer->hdrsize;
127		spin_unlock(&peer->lock);
 
 
128	}
129}
130
131/*
132 * Handle an error received on the local endpoint.
133 */
134void rxrpc_input_error(struct rxrpc_local *local, struct sk_buff *skb)
135{
136	struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
137	struct sockaddr_rxrpc srx;
138	struct rxrpc_peer *peer = NULL;
 
 
139
140	_enter("L=%x", local->debug_id);
141
 
 
 
 
 
 
 
142	if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) {
143		_leave("UDP empty message");
 
144		return;
145	}
146
147	rcu_read_lock();
148	peer = rxrpc_lookup_peer_local_rcu(local, skb, &srx);
149	if (peer && !rxrpc_get_peer_maybe(peer, rxrpc_peer_get_input_error))
150		peer = NULL;
151	rcu_read_unlock();
152	if (!peer)
 
 
153		return;
 
154
155	trace_rxrpc_rx_icmp(peer, &serr->ee, &srx);
156
157	if ((serr->ee.ee_origin == SO_EE_ORIGIN_ICMP &&
158	     serr->ee.ee_type == ICMP_DEST_UNREACH &&
159	     serr->ee.ee_code == ICMP_FRAG_NEEDED)) {
160		rxrpc_adjust_mtu(peer, serr->ee.ee_info);
161		goto out;
 
 
 
 
162	}
163
164	rxrpc_store_error(peer, skb);
165out:
166	rxrpc_put_peer(peer, rxrpc_peer_put_input_error);
 
 
 
 
167}
168
169/*
170 * Map an error report to error codes on the peer record.
171 */
172static void rxrpc_store_error(struct rxrpc_peer *peer, struct sk_buff *skb)
 
173{
174	enum rxrpc_call_completion compl = RXRPC_CALL_NETWORK_ERROR;
175	struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
176	struct sock_extended_err *ee = &serr->ee;
177	int err = ee->ee_errno;
178
179	_enter("");
180
 
 
 
 
181	switch (ee->ee_origin) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
182	case SO_EE_ORIGIN_NONE:
183	case SO_EE_ORIGIN_LOCAL:
184		compl = RXRPC_CALL_LOCAL_ERROR;
 
185		break;
186
187	case SO_EE_ORIGIN_ICMP6:
188		if (err == EACCES)
189			err = EHOSTUNREACH;
190		fallthrough;
191	case SO_EE_ORIGIN_ICMP:
192	default:
 
193		break;
194	}
195
196	rxrpc_distribute_error(peer, skb, compl, err);
197}
198
199/*
200 * Distribute an error that occurred on a peer.
201 */
202static void rxrpc_distribute_error(struct rxrpc_peer *peer, struct sk_buff *skb,
203				   enum rxrpc_call_completion compl, int err)
204{
 
 
205	struct rxrpc_call *call;
206	HLIST_HEAD(error_targets);
 
 
 
 
 
 
 
 
 
 
 
207
208	spin_lock(&peer->lock);
209	hlist_move_list(&peer->error_targets, &error_targets);
210
211	while (!hlist_empty(&error_targets)) {
212		call = hlist_entry(error_targets.first,
 
 
213				   struct rxrpc_call, error_link);
214		hlist_del_init(&call->error_link);
215		spin_unlock(&peer->lock);
216
217		rxrpc_see_call(call, rxrpc_call_see_distribute_error);
218		rxrpc_set_call_completion(call, compl, 0, -err);
219		rxrpc_input_call_event(call, skb);
220
221		spin_lock(&peer->lock);
 
222	}
223
224	spin_unlock(&peer->lock);
 
 
 
225}
226
227/*
228 * Perform keep-alive pings.
 
229 */
230static void rxrpc_peer_keepalive_dispatch(struct rxrpc_net *rxnet,
231					  struct list_head *collector,
232					  time64_t base,
233					  u8 cursor)
234{
235	struct rxrpc_peer *peer;
236	const u8 mask = ARRAY_SIZE(rxnet->peer_keepalive) - 1;
237	time64_t keepalive_at;
238	bool use;
239	int slot;
240
241	spin_lock(&rxnet->peer_hash_lock);
242
243	while (!list_empty(collector)) {
244		peer = list_entry(collector->next,
245				  struct rxrpc_peer, keepalive_link);
246
247		list_del_init(&peer->keepalive_link);
248		if (!rxrpc_get_peer_maybe(peer, rxrpc_peer_get_keepalive))
249			continue;
250
251		use = __rxrpc_use_local(peer->local, rxrpc_local_use_peer_keepalive);
252		spin_unlock(&rxnet->peer_hash_lock);
253
254		if (use) {
255			keepalive_at = peer->last_tx_at + RXRPC_KEEPALIVE_TIME;
256			slot = keepalive_at - base;
257			_debug("%02x peer %u t=%d {%pISp}",
258			       cursor, peer->debug_id, slot, &peer->srx.transport);
259
260			if (keepalive_at <= base ||
261			    keepalive_at > base + RXRPC_KEEPALIVE_TIME) {
262				rxrpc_send_keepalive(peer);
263				slot = RXRPC_KEEPALIVE_TIME;
264			}
265
266			/* A transmission to this peer occurred since last we
267			 * examined it so put it into the appropriate future
268			 * bucket.
269			 */
270			slot += cursor;
271			slot &= mask;
272			spin_lock(&rxnet->peer_hash_lock);
273			list_add_tail(&peer->keepalive_link,
274				      &rxnet->peer_keepalive[slot & mask]);
275			spin_unlock(&rxnet->peer_hash_lock);
276			rxrpc_unuse_local(peer->local, rxrpc_local_unuse_peer_keepalive);
277		}
278		rxrpc_put_peer(peer, rxrpc_peer_put_keepalive);
279		spin_lock(&rxnet->peer_hash_lock);
 
 
 
 
 
 
 
280	}
281
282	spin_unlock(&rxnet->peer_hash_lock);
 
 
283}
284
285/*
286 * Perform keep-alive pings with VERSION packets to keep any NAT alive.
287 */
288void rxrpc_peer_keepalive_worker(struct work_struct *work)
289{
290	struct rxrpc_net *rxnet =
291		container_of(work, struct rxrpc_net, peer_keepalive_work);
292	const u8 mask = ARRAY_SIZE(rxnet->peer_keepalive) - 1;
293	time64_t base, now, delay;
294	u8 cursor, stop;
295	LIST_HEAD(collector);
 
296
297	now = ktime_get_seconds();
298	base = rxnet->peer_keepalive_base;
299	cursor = rxnet->peer_keepalive_cursor;
300	_enter("%lld,%u", base - now, cursor);
301
302	if (!rxnet->live)
303		return;
 
 
 
 
 
 
 
 
 
 
 
 
304
305	/* Remove to a temporary list all the peers that are currently lodged
306	 * in expired buckets plus all new peers.
307	 *
308	 * Everything in the bucket at the cursor is processed this
309	 * second; the bucket at cursor + 1 goes at now + 1s and so
310	 * on...
311	 */
312	spin_lock(&rxnet->peer_hash_lock);
313	list_splice_init(&rxnet->peer_keepalive_new, &collector);
 
 
 
314
315	stop = cursor + ARRAY_SIZE(rxnet->peer_keepalive);
316	while (base <= now && (s8)(cursor - stop) < 0) {
317		list_splice_tail_init(&rxnet->peer_keepalive[cursor & mask],
318				      &collector);
319		base++;
320		cursor++;
321	}
322
323	base = now;
324	spin_unlock(&rxnet->peer_hash_lock);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
325
 
326	rxnet->peer_keepalive_base = base;
327	rxnet->peer_keepalive_cursor = cursor;
328	rxrpc_peer_keepalive_dispatch(rxnet, &collector, base, cursor);
329	ASSERT(list_empty(&collector));
330
331	/* Schedule the timer for the next occupied timeslot. */
332	cursor = rxnet->peer_keepalive_cursor;
333	stop = cursor + RXRPC_KEEPALIVE_TIME - 1;
334	for (; (s8)(cursor - stop) < 0; cursor++) {
335		if (!list_empty(&rxnet->peer_keepalive[cursor & mask]))
336			break;
337		base++;
338	}
339
340	now = ktime_get_seconds();
341	delay = base - now;
342	if (delay < 1)
343		delay = 1;
344	delay *= HZ;
345	if (rxnet->live)
346		timer_reduce(&rxnet->peer_keepalive_timer, jiffies + delay);
347
348	_leave("");
349}
v4.17
 
  1/* Peer event handling, typically ICMP messages.
  2 *
  3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
  4 * Written by David Howells (dhowells@redhat.com)
  5 *
  6 * This program is free software; you can redistribute it and/or
  7 * modify it under the terms of the GNU General Public License
  8 * as published by the Free Software Foundation; either version
  9 * 2 of the License, or (at your option) any later version.
 10 */
 11
 12#include <linux/module.h>
 13#include <linux/net.h>
 14#include <linux/skbuff.h>
 15#include <linux/errqueue.h>
 16#include <linux/udp.h>
 17#include <linux/in.h>
 18#include <linux/in6.h>
 19#include <linux/icmp.h>
 20#include <net/sock.h>
 21#include <net/af_rxrpc.h>
 22#include <net/ip.h>
 23#include "ar-internal.h"
 24
 25static void rxrpc_store_error(struct rxrpc_peer *, struct sock_exterr_skb *);
 
 
 26
 27/*
 28 * Find the peer associated with an ICMP packet.
 29 */
 30static struct rxrpc_peer *rxrpc_lookup_peer_icmp_rcu(struct rxrpc_local *local,
 31						     const struct sk_buff *skb,
 32						     struct sockaddr_rxrpc *srx)
 33{
 34	struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
 35
 36	_enter("");
 37
 38	memset(srx, 0, sizeof(*srx));
 39	srx->transport_type = local->srx.transport_type;
 40	srx->transport_len = local->srx.transport_len;
 41	srx->transport.family = local->srx.transport.family;
 42
 43	/* Can we see an ICMP4 packet on an ICMP6 listening socket?  and vice
 44	 * versa?
 45	 */
 46	switch (srx->transport.family) {
 47	case AF_INET:
 
 
 48		srx->transport.sin.sin_port = serr->port;
 49		switch (serr->ee.ee_origin) {
 50		case SO_EE_ORIGIN_ICMP:
 51			_net("Rx ICMP");
 52			memcpy(&srx->transport.sin.sin_addr,
 53			       skb_network_header(skb) + serr->addr_offset,
 54			       sizeof(struct in_addr));
 55			break;
 56		case SO_EE_ORIGIN_ICMP6:
 57			_net("Rx ICMP6 on v4 sock");
 58			memcpy(&srx->transport.sin.sin_addr,
 59			       skb_network_header(skb) + serr->addr_offset + 12,
 60			       sizeof(struct in_addr));
 61			break;
 62		default:
 63			memcpy(&srx->transport.sin.sin_addr, &ip_hdr(skb)->saddr,
 64			       sizeof(struct in_addr));
 65			break;
 66		}
 67		break;
 68
 69#ifdef CONFIG_AF_RXRPC_IPV6
 70	case AF_INET6:
 71		srx->transport.sin6.sin6_port = serr->port;
 72		switch (serr->ee.ee_origin) {
 73		case SO_EE_ORIGIN_ICMP6:
 74			_net("Rx ICMP6");
 75			memcpy(&srx->transport.sin6.sin6_addr,
 76			       skb_network_header(skb) + serr->addr_offset,
 77			       sizeof(struct in6_addr));
 78			break;
 79		case SO_EE_ORIGIN_ICMP:
 80			_net("Rx ICMP on v6 sock");
 81			srx->transport.sin6.sin6_addr.s6_addr32[0] = 0;
 82			srx->transport.sin6.sin6_addr.s6_addr32[1] = 0;
 83			srx->transport.sin6.sin6_addr.s6_addr32[2] = htonl(0xffff);
 84			memcpy(srx->transport.sin6.sin6_addr.s6_addr + 12,
 85			       skb_network_header(skb) + serr->addr_offset,
 86			       sizeof(struct in_addr));
 87			break;
 88		default:
 89			memcpy(&srx->transport.sin6.sin6_addr,
 90			       &ipv6_hdr(skb)->saddr,
 91			       sizeof(struct in6_addr));
 92			break;
 93		}
 94		break;
 95#endif
 96
 97	default:
 98		BUG();
 99	}
100
101	return rxrpc_lookup_peer_rcu(local, srx);
102}
103
104/*
105 * Handle an MTU/fragmentation problem.
106 */
107static void rxrpc_adjust_mtu(struct rxrpc_peer *peer, struct sock_exterr_skb *serr)
108{
109	u32 mtu = serr->ee.ee_info;
110
111	_net("Rx ICMP Fragmentation Needed (%d)", mtu);
112
113	/* wind down the local interface MTU */
114	if (mtu > 0 && peer->if_mtu == 65535 && mtu < peer->if_mtu) {
115		peer->if_mtu = mtu;
116		_net("I/F MTU %u", mtu);
117	}
118
119	if (mtu == 0) {
120		/* they didn't give us a size, estimate one */
121		mtu = peer->if_mtu;
122		if (mtu > 1500) {
123			mtu >>= 1;
124			if (mtu < 1500)
125				mtu = 1500;
126		} else {
127			mtu -= 100;
128			if (mtu < peer->hdrsize)
129				mtu = peer->hdrsize + 4;
130		}
131	}
132
133	if (mtu < peer->mtu) {
134		spin_lock_bh(&peer->lock);
135		peer->mtu = mtu;
136		peer->maxdata = peer->mtu - peer->hdrsize;
137		spin_unlock_bh(&peer->lock);
138		_net("Net MTU %u (maxdata %u)",
139		     peer->mtu, peer->maxdata);
140	}
141}
142
143/*
144 * Handle an error received on the local endpoint.
145 */
146void rxrpc_error_report(struct sock *sk)
147{
148	struct sock_exterr_skb *serr;
149	struct sockaddr_rxrpc srx;
150	struct rxrpc_local *local = sk->sk_user_data;
151	struct rxrpc_peer *peer;
152	struct sk_buff *skb;
153
154	_enter("%p{%d}", sk, local->debug_id);
155
156	skb = sock_dequeue_err_skb(sk);
157	if (!skb) {
158		_leave("UDP socket errqueue empty");
159		return;
160	}
161	rxrpc_new_skb(skb, rxrpc_skb_rx_received);
162	serr = SKB_EXT_ERR(skb);
163	if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) {
164		_leave("UDP empty message");
165		rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
166		return;
167	}
168
169	rcu_read_lock();
170	peer = rxrpc_lookup_peer_icmp_rcu(local, skb, &srx);
171	if (peer && !rxrpc_get_peer_maybe(peer))
172		peer = NULL;
173	if (!peer) {
174		rcu_read_unlock();
175		rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
176		_leave(" [no peer]");
177		return;
178	}
179
180	trace_rxrpc_rx_icmp(peer, &serr->ee, &srx);
181
182	if ((serr->ee.ee_origin == SO_EE_ORIGIN_ICMP &&
183	     serr->ee.ee_type == ICMP_DEST_UNREACH &&
184	     serr->ee.ee_code == ICMP_FRAG_NEEDED)) {
185		rxrpc_adjust_mtu(peer, serr);
186		rcu_read_unlock();
187		rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
188		rxrpc_put_peer(peer);
189		_leave(" [MTU update]");
190		return;
191	}
192
193	rxrpc_store_error(peer, serr);
194	rcu_read_unlock();
195	rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
196
197	/* The ref we obtained is passed off to the work item */
198	__rxrpc_queue_peer_error(peer);
199	_leave("");
200}
201
202/*
203 * Map an error report to error codes on the peer record.
204 */
205static void rxrpc_store_error(struct rxrpc_peer *peer,
206			      struct sock_exterr_skb *serr)
207{
208	struct sock_extended_err *ee;
209	int err;
 
 
210
211	_enter("");
212
213	ee = &serr->ee;
214
215	err = ee->ee_errno;
216
217	switch (ee->ee_origin) {
218	case SO_EE_ORIGIN_ICMP:
219		switch (ee->ee_type) {
220		case ICMP_DEST_UNREACH:
221			switch (ee->ee_code) {
222			case ICMP_NET_UNREACH:
223				_net("Rx Received ICMP Network Unreachable");
224				break;
225			case ICMP_HOST_UNREACH:
226				_net("Rx Received ICMP Host Unreachable");
227				break;
228			case ICMP_PORT_UNREACH:
229				_net("Rx Received ICMP Port Unreachable");
230				break;
231			case ICMP_NET_UNKNOWN:
232				_net("Rx Received ICMP Unknown Network");
233				break;
234			case ICMP_HOST_UNKNOWN:
235				_net("Rx Received ICMP Unknown Host");
236				break;
237			default:
238				_net("Rx Received ICMP DestUnreach code=%u",
239				     ee->ee_code);
240				break;
241			}
242			break;
243
244		case ICMP_TIME_EXCEEDED:
245			_net("Rx Received ICMP TTL Exceeded");
246			break;
247
248		default:
249			_proto("Rx Received ICMP error { type=%u code=%u }",
250			       ee->ee_type, ee->ee_code);
251			break;
252		}
253		break;
254
255	case SO_EE_ORIGIN_NONE:
256	case SO_EE_ORIGIN_LOCAL:
257		_proto("Rx Received local error { error=%d }", err);
258		err += RXRPC_LOCAL_ERROR_OFFSET;
259		break;
260
261	case SO_EE_ORIGIN_ICMP6:
 
 
 
 
262	default:
263		_proto("Rx Received error report { orig=%u }", ee->ee_origin);
264		break;
265	}
266
267	peer->error_report = err;
268}
269
270/*
271 * Distribute an error that occurred on a peer
272 */
273void rxrpc_peer_error_distributor(struct work_struct *work)
 
274{
275	struct rxrpc_peer *peer =
276		container_of(work, struct rxrpc_peer, error_distributor);
277	struct rxrpc_call *call;
278	enum rxrpc_call_completion compl;
279	int error;
280
281	_enter("");
282
283	error = READ_ONCE(peer->error_report);
284	if (error < RXRPC_LOCAL_ERROR_OFFSET) {
285		compl = RXRPC_CALL_NETWORK_ERROR;
286	} else {
287		compl = RXRPC_CALL_LOCAL_ERROR;
288		error -= RXRPC_LOCAL_ERROR_OFFSET;
289	}
290
291	_debug("ISSUE ERROR %s %d", rxrpc_call_completions[compl], error);
 
292
293	spin_lock_bh(&peer->lock);
294
295	while (!hlist_empty(&peer->error_targets)) {
296		call = hlist_entry(peer->error_targets.first,
297				   struct rxrpc_call, error_link);
298		hlist_del_init(&call->error_link);
299		rxrpc_see_call(call);
 
 
 
 
300
301		if (rxrpc_set_call_completion(call, compl, 0, -error))
302			rxrpc_notify_socket(call);
303	}
304
305	spin_unlock_bh(&peer->lock);
306
307	rxrpc_put_peer(peer);
308	_leave("");
309}
310
311/*
312 * Add RTT information to cache.  This is called in softirq mode and has
313 * exclusive access to the peer RTT data.
314 */
315void rxrpc_peer_add_rtt(struct rxrpc_call *call, enum rxrpc_rtt_rx_trace why,
316			rxrpc_serial_t send_serial, rxrpc_serial_t resp_serial,
317			ktime_t send_time, ktime_t resp_time)
 
318{
319	struct rxrpc_peer *peer = call->peer;
320	s64 rtt;
321	u64 sum = peer->rtt_sum, avg;
322	u8 cursor = peer->rtt_cursor, usage = peer->rtt_usage;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
323
324	rtt = ktime_to_ns(ktime_sub(resp_time, send_time));
325	if (rtt < 0)
326		return;
327
328	/* Replace the oldest datum in the RTT buffer */
329	sum -= peer->rtt_cache[cursor];
330	sum += rtt;
331	peer->rtt_cache[cursor] = rtt;
332	peer->rtt_cursor = (cursor + 1) & (RXRPC_RTT_CACHE_SIZE - 1);
333	peer->rtt_sum = sum;
334	if (usage < RXRPC_RTT_CACHE_SIZE) {
335		usage++;
336		peer->rtt_usage = usage;
337	}
338
339	/* Now recalculate the average */
340	if (usage == RXRPC_RTT_CACHE_SIZE) {
341		avg = sum / RXRPC_RTT_CACHE_SIZE;
342	} else {
343		avg = sum;
344		do_div(avg, usage);
345	}
346
347	peer->rtt = avg;
348	trace_rxrpc_rtt_rx(call, why, send_serial, resp_serial, rtt,
349			   usage, avg);
350}
351
352/*
353 * Perform keep-alive pings with VERSION packets to keep any NAT alive.
354 */
355void rxrpc_peer_keepalive_worker(struct work_struct *work)
356{
357	struct rxrpc_net *rxnet =
358		container_of(work, struct rxrpc_net, peer_keepalive_work);
359	struct rxrpc_peer *peer;
360	unsigned long delay;
361	ktime_t base, now = ktime_get_real();
362	s64 diff;
363	u8 cursor, slot;
364
 
365	base = rxnet->peer_keepalive_base;
366	cursor = rxnet->peer_keepalive_cursor;
 
367
368	_enter("%u,%lld", cursor, ktime_sub(now, base));
369
370next_bucket:
371	diff = ktime_to_ns(ktime_sub(now, base));
372	if (diff < 0)
373		goto resched;
374
375	_debug("at %u", cursor);
376	spin_lock_bh(&rxnet->peer_hash_lock);
377next_peer:
378	if (!rxnet->live) {
379		spin_unlock_bh(&rxnet->peer_hash_lock);
380		goto out;
381	}
382
383	/* Everything in the bucket at the cursor is processed this second; the
384	 * bucket at cursor + 1 goes now + 1s and so on...
 
 
 
 
385	 */
386	if (hlist_empty(&rxnet->peer_keepalive[cursor])) {
387		if (hlist_empty(&rxnet->peer_keepalive_new)) {
388			spin_unlock_bh(&rxnet->peer_hash_lock);
389			goto emptied_bucket;
390		}
391
392		hlist_move_list(&rxnet->peer_keepalive_new,
393				&rxnet->peer_keepalive[cursor]);
 
 
 
 
394	}
395
396	peer = hlist_entry(rxnet->peer_keepalive[cursor].first,
397			   struct rxrpc_peer, keepalive_link);
398	hlist_del_init(&peer->keepalive_link);
399	if (!rxrpc_get_peer_maybe(peer))
400		goto next_peer;
401
402	spin_unlock_bh(&rxnet->peer_hash_lock);
403
404	_debug("peer %u {%pISp}", peer->debug_id, &peer->srx.transport);
405
406recalc:
407	diff = ktime_divns(ktime_sub(peer->last_tx_at, base), NSEC_PER_SEC);
408	if (diff < -30 || diff > 30)
409		goto send; /* LSW of 64-bit time probably wrapped on 32-bit */
410	diff += RXRPC_KEEPALIVE_TIME - 1;
411	if (diff < 0)
412		goto send;
413
414	slot = (diff > RXRPC_KEEPALIVE_TIME - 1) ? RXRPC_KEEPALIVE_TIME - 1 : diff;
415	if (slot == 0)
416		goto send;
417
418	/* A transmission to this peer occurred since last we examined it so
419	 * put it into the appropriate future bucket.
420	 */
421	slot = (slot + cursor) % ARRAY_SIZE(rxnet->peer_keepalive);
422	spin_lock_bh(&rxnet->peer_hash_lock);
423	hlist_add_head(&peer->keepalive_link, &rxnet->peer_keepalive[slot]);
424	rxrpc_put_peer(peer);
425	goto next_peer;
426
427send:
428	rxrpc_send_keepalive(peer);
429	now = ktime_get_real();
430	goto recalc;
431
432emptied_bucket:
433	cursor++;
434	if (cursor >= ARRAY_SIZE(rxnet->peer_keepalive))
435		cursor = 0;
436	base = ktime_add_ns(base, NSEC_PER_SEC);
437	goto next_bucket;
438
439resched:
440	rxnet->peer_keepalive_base = base;
441	rxnet->peer_keepalive_cursor = cursor;
442	delay = nsecs_to_jiffies(-diff) + 1;
443	timer_reduce(&rxnet->peer_keepalive_timer, jiffies + delay);
444out:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
445	_leave("");
446}