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v5.9
  1/*
  2 * net/tipc/bcast.c: TIPC broadcast code
  3 *
  4 * Copyright (c) 2004-2006, 2014-2017, Ericsson AB
  5 * Copyright (c) 2004, Intel Corporation.
  6 * Copyright (c) 2005, 2010-2011, Wind River Systems
  7 * All rights reserved.
  8 *
  9 * Redistribution and use in source and binary forms, with or without
 10 * modification, are permitted provided that the following conditions are met:
 11 *
 12 * 1. Redistributions of source code must retain the above copyright
 13 *    notice, this list of conditions and the following disclaimer.
 14 * 2. Redistributions in binary form must reproduce the above copyright
 15 *    notice, this list of conditions and the following disclaimer in the
 16 *    documentation and/or other materials provided with the distribution.
 17 * 3. Neither the names of the copyright holders nor the names of its
 18 *    contributors may be used to endorse or promote products derived from
 19 *    this software without specific prior written permission.
 20 *
 21 * Alternatively, this software may be distributed under the terms of the
 22 * GNU General Public License ("GPL") version 2 as published by the Free
 23 * Software Foundation.
 24 *
 25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 26 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 29 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 35 * POSSIBILITY OF SUCH DAMAGE.
 36 */
 37
 38#include <linux/tipc_config.h>
 39#include "socket.h"
 40#include "msg.h"
 41#include "bcast.h"
 
 42#include "link.h"
 43#include "name_table.h"
 44
 45#define BCLINK_WIN_DEFAULT  50	/* bcast link window size (default) */
 46#define BCLINK_WIN_MIN      32	/* bcast minimum link window size */
 47
 48const char tipc_bclink_name[] = "broadcast-link";
 49unsigned long sysctl_tipc_bc_retruni __read_mostly;
 50
 51/**
 52 * struct tipc_bc_base - base structure for keeping broadcast send state
 53 * @link: broadcast send link structure
 54 * @inputq: data input queue; will only carry SOCK_WAKEUP messages
 55 * @dests: array keeping number of reachable destinations per bearer
 56 * @primary_bearer: a bearer having links to all broadcast destinations, if any
 57 * @bcast_support: indicates if primary bearer, if any, supports broadcast
 58 * @force_bcast: forces broadcast for multicast traffic
 59 * @rcast_support: indicates if all peer nodes support replicast
 60 * @force_rcast: forces replicast for multicast traffic
 61 * @rc_ratio: dest count as percentage of cluster size where send method changes
 62 * @bc_threshold: calculated from rc_ratio; if dests > threshold use broadcast
 63 */
 64struct tipc_bc_base {
 65	struct tipc_link *link;
 66	struct sk_buff_head inputq;
 67	int dests[MAX_BEARERS];
 68	int primary_bearer;
 69	bool bcast_support;
 70	bool force_bcast;
 71	bool rcast_support;
 72	bool force_rcast;
 73	int rc_ratio;
 74	int bc_threshold;
 75};
 76
 77static struct tipc_bc_base *tipc_bc_base(struct net *net)
 78{
 79	return tipc_net(net)->bcbase;
 80}
 81
 82/* tipc_bcast_get_mtu(): -get the MTU currently used by broadcast link
 83 * Note: the MTU is decremented to give room for a tunnel header, in
 84 * case the message needs to be sent as replicast
 85 */
 86int tipc_bcast_get_mtu(struct net *net)
 87{
 88	return tipc_link_mss(tipc_bc_sndlink(net));
 89}
 90
 91void tipc_bcast_toggle_rcast(struct net *net, bool supp)
 92{
 93	tipc_bc_base(net)->rcast_support = supp;
 94}
 95
 96static void tipc_bcbase_calc_bc_threshold(struct net *net)
 97{
 98	struct tipc_bc_base *bb = tipc_bc_base(net);
 99	int cluster_size = tipc_link_bc_peers(tipc_bc_sndlink(net));
100
101	bb->bc_threshold = 1 + (cluster_size * bb->rc_ratio / 100);
102}
103
104/* tipc_bcbase_select_primary(): find a bearer with links to all destinations,
105 *                               if any, and make it primary bearer
106 */
107static void tipc_bcbase_select_primary(struct net *net)
108{
109	struct tipc_bc_base *bb = tipc_bc_base(net);
110	int all_dests =  tipc_link_bc_peers(bb->link);
111	int i, mtu, prim;
112
113	bb->primary_bearer = INVALID_BEARER_ID;
114	bb->bcast_support = true;
115
116	if (!all_dests)
117		return;
118
119	for (i = 0; i < MAX_BEARERS; i++) {
120		if (!bb->dests[i])
121			continue;
122
123		mtu = tipc_bearer_mtu(net, i);
124		if (mtu < tipc_link_mtu(bb->link))
125			tipc_link_set_mtu(bb->link, mtu);
126		bb->bcast_support &= tipc_bearer_bcast_support(net, i);
127		if (bb->dests[i] < all_dests)
128			continue;
129
130		bb->primary_bearer = i;
131
132		/* Reduce risk that all nodes select same primary */
133		if ((i ^ tipc_own_addr(net)) & 1)
134			break;
135	}
136	prim = bb->primary_bearer;
137	if (prim != INVALID_BEARER_ID)
138		bb->bcast_support = tipc_bearer_bcast_support(net, prim);
139}
140
141void tipc_bcast_inc_bearer_dst_cnt(struct net *net, int bearer_id)
142{
143	struct tipc_bc_base *bb = tipc_bc_base(net);
144
145	tipc_bcast_lock(net);
146	bb->dests[bearer_id]++;
147	tipc_bcbase_select_primary(net);
148	tipc_bcast_unlock(net);
149}
150
151void tipc_bcast_dec_bearer_dst_cnt(struct net *net, int bearer_id)
152{
153	struct tipc_bc_base *bb = tipc_bc_base(net);
154
155	tipc_bcast_lock(net);
156	bb->dests[bearer_id]--;
157	tipc_bcbase_select_primary(net);
158	tipc_bcast_unlock(net);
159}
160
161/* tipc_bcbase_xmit - broadcast a packet queue across one or more bearers
162 *
163 * Note that number of reachable destinations, as indicated in the dests[]
164 * array, may transitionally differ from the number of destinations indicated
165 * in each sent buffer. We can sustain this. Excess destination nodes will
166 * drop and never acknowledge the unexpected packets, and missing destinations
167 * will either require retransmission (if they are just about to be added to
168 * the bearer), or be removed from the buffer's 'ackers' counter (if they
169 * just went down)
170 */
171static void tipc_bcbase_xmit(struct net *net, struct sk_buff_head *xmitq)
172{
173	int bearer_id;
174	struct tipc_bc_base *bb = tipc_bc_base(net);
175	struct sk_buff *skb, *_skb;
176	struct sk_buff_head _xmitq;
177
178	if (skb_queue_empty(xmitq))
179		return;
180
181	/* The typical case: at least one bearer has links to all nodes */
182	bearer_id = bb->primary_bearer;
183	if (bearer_id >= 0) {
184		tipc_bearer_bc_xmit(net, bearer_id, xmitq);
185		return;
186	}
187
188	/* We have to transmit across all bearers */
189	__skb_queue_head_init(&_xmitq);
190	for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
191		if (!bb->dests[bearer_id])
192			continue;
193
194		skb_queue_walk(xmitq, skb) {
195			_skb = pskb_copy_for_clone(skb, GFP_ATOMIC);
196			if (!_skb)
197				break;
198			__skb_queue_tail(&_xmitq, _skb);
199		}
200		tipc_bearer_bc_xmit(net, bearer_id, &_xmitq);
201	}
202	__skb_queue_purge(xmitq);
203	__skb_queue_purge(&_xmitq);
204}
205
206static void tipc_bcast_select_xmit_method(struct net *net, int dests,
207					  struct tipc_mc_method *method)
208{
209	struct tipc_bc_base *bb = tipc_bc_base(net);
210	unsigned long exp = method->expires;
211
212	/* Broadcast supported by used bearer/bearers? */
213	if (!bb->bcast_support) {
214		method->rcast = true;
215		return;
216	}
217	/* Any destinations which don't support replicast ? */
218	if (!bb->rcast_support) {
219		method->rcast = false;
220		return;
221	}
222	/* Can current method be changed ? */
223	method->expires = jiffies + TIPC_METHOD_EXPIRE;
224	if (method->mandatory)
225		return;
226
227	if (!(tipc_net(net)->capabilities & TIPC_MCAST_RBCTL) &&
228	    time_before(jiffies, exp))
229		return;
230
231	/* Configuration as force 'broadcast' method */
232	if (bb->force_bcast) {
233		method->rcast = false;
234		return;
235	}
236	/* Configuration as force 'replicast' method */
237	if (bb->force_rcast) {
238		method->rcast = true;
239		return;
240	}
241	/* Configuration as 'autoselect' or default method */
242	/* Determine method to use now */
243	method->rcast = dests <= bb->bc_threshold;
244}
245
246/* tipc_bcast_xmit - broadcast the buffer chain to all external nodes
247 * @net: the applicable net namespace
248 * @pkts: chain of buffers containing message
249 * @cong_link_cnt: set to 1 if broadcast link is congested, otherwise 0
250 * Consumes the buffer chain.
251 * Returns 0 if success, otherwise errno: -EHOSTUNREACH,-EMSGSIZE
252 */
253int tipc_bcast_xmit(struct net *net, struct sk_buff_head *pkts,
254		    u16 *cong_link_cnt)
255{
256	struct tipc_link *l = tipc_bc_sndlink(net);
257	struct sk_buff_head xmitq;
258	int rc = 0;
259
 
260	__skb_queue_head_init(&xmitq);
 
 
 
 
 
 
261	tipc_bcast_lock(net);
262	if (tipc_link_bc_peers(l))
263		rc = tipc_link_xmit(l, pkts, &xmitq);
264	tipc_bcast_unlock(net);
265	tipc_bcbase_xmit(net, &xmitq);
266	__skb_queue_purge(pkts);
267	if (rc == -ELINKCONG) {
268		*cong_link_cnt = 1;
269		rc = 0;
270	}
271	return rc;
272}
273
274/* tipc_rcast_xmit - replicate and send a message to given destination nodes
275 * @net: the applicable net namespace
276 * @pkts: chain of buffers containing message
277 * @dests: list of destination nodes
278 * @cong_link_cnt: returns number of congested links
279 * @cong_links: returns identities of congested links
280 * Returns 0 if success, otherwise errno
281 */
282static int tipc_rcast_xmit(struct net *net, struct sk_buff_head *pkts,
283			   struct tipc_nlist *dests, u16 *cong_link_cnt)
284{
285	struct tipc_dest *dst, *tmp;
286	struct sk_buff_head _pkts;
287	u32 dnode, selector;
288
289	selector = msg_link_selector(buf_msg(skb_peek(pkts)));
290	__skb_queue_head_init(&_pkts);
291
292	list_for_each_entry_safe(dst, tmp, &dests->list, list) {
293		dnode = dst->node;
294		if (!tipc_msg_pskb_copy(dnode, pkts, &_pkts))
295			return -ENOMEM;
296
297		/* Any other return value than -ELINKCONG is ignored */
298		if (tipc_node_xmit(net, &_pkts, dnode, selector) == -ELINKCONG)
299			(*cong_link_cnt)++;
300	}
301	return 0;
302}
303
304/* tipc_mcast_send_sync - deliver a dummy message with SYN bit
305 * @net: the applicable net namespace
306 * @skb: socket buffer to copy
307 * @method: send method to be used
308 * @dests: destination nodes for message.
309 * Returns 0 if success, otherwise errno
310 */
311static int tipc_mcast_send_sync(struct net *net, struct sk_buff *skb,
312				struct tipc_mc_method *method,
313				struct tipc_nlist *dests)
314{
315	struct tipc_msg *hdr, *_hdr;
316	struct sk_buff_head tmpq;
317	struct sk_buff *_skb;
318	u16 cong_link_cnt;
319	int rc = 0;
320
321	/* Is a cluster supporting with new capabilities ? */
322	if (!(tipc_net(net)->capabilities & TIPC_MCAST_RBCTL))
323		return 0;
324
325	hdr = buf_msg(skb);
326	if (msg_user(hdr) == MSG_FRAGMENTER)
327		hdr = msg_inner_hdr(hdr);
328	if (msg_type(hdr) != TIPC_MCAST_MSG)
329		return 0;
330
331	/* Allocate dummy message */
332	_skb = tipc_buf_acquire(MCAST_H_SIZE, GFP_KERNEL);
333	if (!_skb)
334		return -ENOMEM;
335
336	/* Preparing for 'synching' header */
337	msg_set_syn(hdr, 1);
338
339	/* Copy skb's header into a dummy header */
340	skb_copy_to_linear_data(_skb, hdr, MCAST_H_SIZE);
341	skb_orphan(_skb);
342
343	/* Reverse method for dummy message */
344	_hdr = buf_msg(_skb);
345	msg_set_size(_hdr, MCAST_H_SIZE);
346	msg_set_is_rcast(_hdr, !msg_is_rcast(hdr));
347	msg_set_errcode(_hdr, TIPC_ERR_NO_PORT);
348
349	__skb_queue_head_init(&tmpq);
350	__skb_queue_tail(&tmpq, _skb);
351	if (method->rcast)
352		rc = tipc_bcast_xmit(net, &tmpq, &cong_link_cnt);
353	else
354		rc = tipc_rcast_xmit(net, &tmpq, dests, &cong_link_cnt);
355
356	/* This queue should normally be empty by now */
357	__skb_queue_purge(&tmpq);
358
359	return rc;
360}
361
362/* tipc_mcast_xmit - deliver message to indicated destination nodes
363 *                   and to identified node local sockets
364 * @net: the applicable net namespace
365 * @pkts: chain of buffers containing message
366 * @method: send method to be used
367 * @dests: destination nodes for message.
368 * @cong_link_cnt: returns number of encountered congested destination links
369 * Consumes buffer chain.
370 * Returns 0 if success, otherwise errno
371 */
372int tipc_mcast_xmit(struct net *net, struct sk_buff_head *pkts,
373		    struct tipc_mc_method *method, struct tipc_nlist *dests,
374		    u16 *cong_link_cnt)
375{
376	struct sk_buff_head inputq, localq;
377	bool rcast = method->rcast;
378	struct tipc_msg *hdr;
379	struct sk_buff *skb;
380	int rc = 0;
381
382	skb_queue_head_init(&inputq);
383	__skb_queue_head_init(&localq);
384
385	/* Clone packets before they are consumed by next call */
386	if (dests->local && !tipc_msg_reassemble(pkts, &localq)) {
387		rc = -ENOMEM;
388		goto exit;
389	}
390	/* Send according to determined transmit method */
391	if (dests->remote) {
392		tipc_bcast_select_xmit_method(net, dests->remote, method);
393
394		skb = skb_peek(pkts);
395		hdr = buf_msg(skb);
396		if (msg_user(hdr) == MSG_FRAGMENTER)
397			hdr = msg_inner_hdr(hdr);
398		msg_set_is_rcast(hdr, method->rcast);
399
400		/* Switch method ? */
401		if (rcast != method->rcast) {
402			rc = tipc_mcast_send_sync(net, skb, method, dests);
403			if (unlikely(rc)) {
404				pr_err("Unable to send SYN: method %d, rc %d\n",
405				       rcast, rc);
406				goto exit;
407			}
408		}
409
410		if (method->rcast)
411			rc = tipc_rcast_xmit(net, pkts, dests, cong_link_cnt);
412		else
413			rc = tipc_bcast_xmit(net, pkts, cong_link_cnt);
414	}
415
416	if (dests->local) {
417		tipc_loopback_trace(net, &localq);
418		tipc_sk_mcast_rcv(net, &localq, &inputq);
419	}
420exit:
421	/* This queue should normally be empty by now */
422	__skb_queue_purge(pkts);
423	return rc;
424}
425
426/* tipc_bcast_rcv - receive a broadcast packet, and deliver to rcv link
427 *
428 * RCU is locked, no other locks set
429 */
430int tipc_bcast_rcv(struct net *net, struct tipc_link *l, struct sk_buff *skb)
431{
432	struct tipc_msg *hdr = buf_msg(skb);
433	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
434	struct sk_buff_head xmitq;
435	int rc;
436
437	__skb_queue_head_init(&xmitq);
438
439	if (msg_mc_netid(hdr) != tipc_netid(net) || !tipc_link_is_up(l)) {
440		kfree_skb(skb);
441		return 0;
442	}
443
444	tipc_bcast_lock(net);
445	if (msg_user(hdr) == BCAST_PROTOCOL)
446		rc = tipc_link_bc_nack_rcv(l, skb, &xmitq);
447	else
448		rc = tipc_link_rcv(l, skb, NULL);
449	tipc_bcast_unlock(net);
450
451	tipc_bcbase_xmit(net, &xmitq);
452
453	/* Any socket wakeup messages ? */
454	if (!skb_queue_empty(inputq))
455		tipc_sk_rcv(net, inputq);
456
457	return rc;
458}
459
460/* tipc_bcast_ack_rcv - receive and handle a broadcast acknowledge
461 *
462 * RCU is locked, no other locks set
463 */
464void tipc_bcast_ack_rcv(struct net *net, struct tipc_link *l,
465			struct tipc_msg *hdr)
466{
467	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
468	u16 acked = msg_bcast_ack(hdr);
469	struct sk_buff_head xmitq;
470
471	/* Ignore bc acks sent by peer before bcast synch point was received */
472	if (msg_bc_ack_invalid(hdr))
473		return;
474
475	__skb_queue_head_init(&xmitq);
476
477	tipc_bcast_lock(net);
478	tipc_link_bc_ack_rcv(l, acked, 0, NULL, &xmitq, NULL);
479	tipc_bcast_unlock(net);
480
481	tipc_bcbase_xmit(net, &xmitq);
482
483	/* Any socket wakeup messages ? */
484	if (!skb_queue_empty(inputq))
485		tipc_sk_rcv(net, inputq);
486}
487
488/* tipc_bcast_synch_rcv -  check and update rcv link with peer's send state
489 *
490 * RCU is locked, no other locks set
491 */
492int tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l,
493			struct tipc_msg *hdr,
494			struct sk_buff_head *retrq)
495{
496	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
497	struct tipc_gap_ack_blks *ga;
498	struct sk_buff_head xmitq;
499	int rc = 0;
500
501	__skb_queue_head_init(&xmitq);
502
503	tipc_bcast_lock(net);
504	if (msg_type(hdr) != STATE_MSG) {
 
 
 
505		tipc_link_bc_init_rcv(l, hdr);
506	} else if (!msg_bc_ack_invalid(hdr)) {
507		tipc_get_gap_ack_blks(&ga, l, hdr, false);
508		if (!sysctl_tipc_bc_retruni)
509			retrq = &xmitq;
510		rc = tipc_link_bc_ack_rcv(l, msg_bcast_ack(hdr),
511					  msg_bc_gap(hdr), ga, &xmitq,
512					  retrq);
513		rc |= tipc_link_bc_sync_rcv(l, hdr, &xmitq);
514	}
515	tipc_bcast_unlock(net);
516
517	tipc_bcbase_xmit(net, &xmitq);
518
519	/* Any socket wakeup messages ? */
520	if (!skb_queue_empty(inputq))
521		tipc_sk_rcv(net, inputq);
522	return rc;
523}
524
525/* tipc_bcast_add_peer - add a peer node to broadcast link and bearer
526 *
527 * RCU is locked, node lock is set
528 */
529void tipc_bcast_add_peer(struct net *net, struct tipc_link *uc_l,
530			 struct sk_buff_head *xmitq)
531{
532	struct tipc_link *snd_l = tipc_bc_sndlink(net);
533
534	tipc_bcast_lock(net);
535	tipc_link_add_bc_peer(snd_l, uc_l, xmitq);
536	tipc_bcbase_select_primary(net);
537	tipc_bcbase_calc_bc_threshold(net);
538	tipc_bcast_unlock(net);
539}
540
541/* tipc_bcast_remove_peer - remove a peer node from broadcast link and bearer
542 *
543 * RCU is locked, node lock is set
544 */
545void tipc_bcast_remove_peer(struct net *net, struct tipc_link *rcv_l)
546{
547	struct tipc_link *snd_l = tipc_bc_sndlink(net);
548	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
549	struct sk_buff_head xmitq;
550
551	__skb_queue_head_init(&xmitq);
552
553	tipc_bcast_lock(net);
554	tipc_link_remove_bc_peer(snd_l, rcv_l, &xmitq);
555	tipc_bcbase_select_primary(net);
556	tipc_bcbase_calc_bc_threshold(net);
557	tipc_bcast_unlock(net);
558
559	tipc_bcbase_xmit(net, &xmitq);
560
561	/* Any socket wakeup messages ? */
562	if (!skb_queue_empty(inputq))
563		tipc_sk_rcv(net, inputq);
564}
565
566int tipc_bclink_reset_stats(struct net *net, struct tipc_link *l)
567{
 
 
568	if (!l)
569		return -ENOPROTOOPT;
570
571	tipc_bcast_lock(net);
572	tipc_link_reset_stats(l);
573	tipc_bcast_unlock(net);
574	return 0;
575}
576
577static int tipc_bc_link_set_queue_limits(struct net *net, u32 max_win)
578{
579	struct tipc_link *l = tipc_bc_sndlink(net);
580
581	if (!l)
582		return -ENOPROTOOPT;
583	if (max_win < BCLINK_WIN_MIN)
584		max_win = BCLINK_WIN_MIN;
585	if (max_win > TIPC_MAX_LINK_WIN)
586		return -EINVAL;
587	tipc_bcast_lock(net);
588	tipc_link_set_queue_limits(l, BCLINK_WIN_MIN, max_win);
589	tipc_bcast_unlock(net);
590	return 0;
591}
592
593static int tipc_bc_link_set_broadcast_mode(struct net *net, u32 bc_mode)
594{
595	struct tipc_bc_base *bb = tipc_bc_base(net);
596
597	switch (bc_mode) {
598	case BCLINK_MODE_BCAST:
599		if (!bb->bcast_support)
600			return -ENOPROTOOPT;
601
602		bb->force_bcast = true;
603		bb->force_rcast = false;
604		break;
605	case BCLINK_MODE_RCAST:
606		if (!bb->rcast_support)
607			return -ENOPROTOOPT;
608
609		bb->force_bcast = false;
610		bb->force_rcast = true;
611		break;
612	case BCLINK_MODE_SEL:
613		if (!bb->bcast_support || !bb->rcast_support)
614			return -ENOPROTOOPT;
615
616		bb->force_bcast = false;
617		bb->force_rcast = false;
618		break;
619	default:
620		return -EINVAL;
621	}
622
623	return 0;
624}
625
626static int tipc_bc_link_set_broadcast_ratio(struct net *net, u32 bc_ratio)
627{
628	struct tipc_bc_base *bb = tipc_bc_base(net);
629
630	if (!bb->bcast_support || !bb->rcast_support)
631		return -ENOPROTOOPT;
632
633	if (bc_ratio > 100 || bc_ratio <= 0)
634		return -EINVAL;
635
636	bb->rc_ratio = bc_ratio;
637	tipc_bcast_lock(net);
638	tipc_bcbase_calc_bc_threshold(net);
639	tipc_bcast_unlock(net);
640
641	return 0;
642}
643
644int tipc_nl_bc_link_set(struct net *net, struct nlattr *attrs[])
645{
646	int err;
647	u32 win;
648	u32 bc_mode;
649	u32 bc_ratio;
650	struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
651
652	if (!attrs[TIPC_NLA_LINK_PROP])
653		return -EINVAL;
654
655	err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP], props);
656	if (err)
657		return err;
658
659	if (!props[TIPC_NLA_PROP_WIN] &&
660	    !props[TIPC_NLA_PROP_BROADCAST] &&
661	    !props[TIPC_NLA_PROP_BROADCAST_RATIO]) {
662		return -EOPNOTSUPP;
663	}
664
665	if (props[TIPC_NLA_PROP_BROADCAST]) {
666		bc_mode = nla_get_u32(props[TIPC_NLA_PROP_BROADCAST]);
667		err = tipc_bc_link_set_broadcast_mode(net, bc_mode);
668	}
669
670	if (!err && props[TIPC_NLA_PROP_BROADCAST_RATIO]) {
671		bc_ratio = nla_get_u32(props[TIPC_NLA_PROP_BROADCAST_RATIO]);
672		err = tipc_bc_link_set_broadcast_ratio(net, bc_ratio);
673	}
674
675	if (!err && props[TIPC_NLA_PROP_WIN]) {
676		win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
677		err = tipc_bc_link_set_queue_limits(net, win);
678	}
679
680	return err;
681}
682
683int tipc_bcast_init(struct net *net)
684{
685	struct tipc_net *tn = tipc_net(net);
686	struct tipc_bc_base *bb = NULL;
687	struct tipc_link *l = NULL;
688
689	bb = kzalloc(sizeof(*bb), GFP_KERNEL);
690	if (!bb)
691		goto enomem;
692	tn->bcbase = bb;
693	spin_lock_init(&tipc_net(net)->bclock);
694
695	if (!tipc_link_bc_create(net, 0, 0, NULL,
696				 FB_MTU,
697				 BCLINK_WIN_DEFAULT,
698				 BCLINK_WIN_DEFAULT,
699				 0,
700				 &bb->inputq,
701				 NULL,
702				 NULL,
703				 &l))
704		goto enomem;
705	bb->link = l;
706	tn->bcl = l;
707	bb->rc_ratio = 10;
708	bb->rcast_support = true;
709	return 0;
710enomem:
711	kfree(bb);
712	kfree(l);
713	return -ENOMEM;
714}
715
716void tipc_bcast_stop(struct net *net)
717{
718	struct tipc_net *tn = net_generic(net, tipc_net_id);
719
720	synchronize_net();
721	kfree(tn->bcbase);
722	kfree(tn->bcl);
723}
724
725void tipc_nlist_init(struct tipc_nlist *nl, u32 self)
726{
727	memset(nl, 0, sizeof(*nl));
728	INIT_LIST_HEAD(&nl->list);
729	nl->self = self;
730}
731
732void tipc_nlist_add(struct tipc_nlist *nl, u32 node)
733{
734	if (node == nl->self)
735		nl->local = true;
736	else if (tipc_dest_push(&nl->list, node, 0))
737		nl->remote++;
738}
739
740void tipc_nlist_del(struct tipc_nlist *nl, u32 node)
741{
742	if (node == nl->self)
743		nl->local = false;
744	else if (tipc_dest_del(&nl->list, node, 0))
745		nl->remote--;
746}
747
748void tipc_nlist_purge(struct tipc_nlist *nl)
749{
750	tipc_dest_list_purge(&nl->list);
751	nl->remote = 0;
752	nl->local = false;
753}
754
755u32 tipc_bcast_get_mode(struct net *net)
756{
757	struct tipc_bc_base *bb = tipc_bc_base(net);
758
759	if (bb->force_bcast)
760		return BCLINK_MODE_BCAST;
761
762	if (bb->force_rcast)
763		return BCLINK_MODE_RCAST;
764
765	if (bb->bcast_support && bb->rcast_support)
766		return BCLINK_MODE_SEL;
767
768	return 0;
769}
770
771u32 tipc_bcast_get_broadcast_ratio(struct net *net)
772{
773	struct tipc_bc_base *bb = tipc_bc_base(net);
774
775	return bb->rc_ratio;
776}
777
778void tipc_mcast_filter_msg(struct net *net, struct sk_buff_head *defq,
779			   struct sk_buff_head *inputq)
780{
781	struct sk_buff *skb, *_skb, *tmp;
782	struct tipc_msg *hdr, *_hdr;
783	bool match = false;
784	u32 node, port;
785
786	skb = skb_peek(inputq);
787	if (!skb)
788		return;
789
790	hdr = buf_msg(skb);
791
792	if (likely(!msg_is_syn(hdr) && skb_queue_empty(defq)))
793		return;
794
795	node = msg_orignode(hdr);
796	if (node == tipc_own_addr(net))
797		return;
798
799	port = msg_origport(hdr);
800
801	/* Has the twin SYN message already arrived ? */
802	skb_queue_walk(defq, _skb) {
803		_hdr = buf_msg(_skb);
804		if (msg_orignode(_hdr) != node)
805			continue;
806		if (msg_origport(_hdr) != port)
807			continue;
808		match = true;
809		break;
810	}
811
812	if (!match) {
813		if (!msg_is_syn(hdr))
814			return;
815		__skb_dequeue(inputq);
816		__skb_queue_tail(defq, skb);
817		return;
818	}
819
820	/* Deliver non-SYN message from other link, otherwise queue it */
821	if (!msg_is_syn(hdr)) {
822		if (msg_is_rcast(hdr) != msg_is_rcast(_hdr))
823			return;
824		__skb_dequeue(inputq);
825		__skb_queue_tail(defq, skb);
826		return;
827	}
828
829	/* Queue non-SYN/SYN message from same link */
830	if (msg_is_rcast(hdr) == msg_is_rcast(_hdr)) {
831		__skb_dequeue(inputq);
832		__skb_queue_tail(defq, skb);
833		return;
834	}
835
836	/* Matching SYN messages => return the one with data, if any */
837	__skb_unlink(_skb, defq);
838	if (msg_data_sz(hdr)) {
839		kfree_skb(_skb);
840	} else {
841		__skb_dequeue(inputq);
842		kfree_skb(skb);
843		__skb_queue_tail(inputq, _skb);
844	}
845
846	/* Deliver subsequent non-SYN messages from same peer */
847	skb_queue_walk_safe(defq, _skb, tmp) {
848		_hdr = buf_msg(_skb);
849		if (msg_orignode(_hdr) != node)
850			continue;
851		if (msg_origport(_hdr) != port)
852			continue;
853		if (msg_is_syn(_hdr))
854			break;
855		__skb_unlink(_skb, defq);
856		__skb_queue_tail(inputq, _skb);
857	}
858}
v4.6
  1/*
  2 * net/tipc/bcast.c: TIPC broadcast code
  3 *
  4 * Copyright (c) 2004-2006, 2014-2015, Ericsson AB
  5 * Copyright (c) 2004, Intel Corporation.
  6 * Copyright (c) 2005, 2010-2011, Wind River Systems
  7 * All rights reserved.
  8 *
  9 * Redistribution and use in source and binary forms, with or without
 10 * modification, are permitted provided that the following conditions are met:
 11 *
 12 * 1. Redistributions of source code must retain the above copyright
 13 *    notice, this list of conditions and the following disclaimer.
 14 * 2. Redistributions in binary form must reproduce the above copyright
 15 *    notice, this list of conditions and the following disclaimer in the
 16 *    documentation and/or other materials provided with the distribution.
 17 * 3. Neither the names of the copyright holders nor the names of its
 18 *    contributors may be used to endorse or promote products derived from
 19 *    this software without specific prior written permission.
 20 *
 21 * Alternatively, this software may be distributed under the terms of the
 22 * GNU General Public License ("GPL") version 2 as published by the Free
 23 * Software Foundation.
 24 *
 25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 26 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 29 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 35 * POSSIBILITY OF SUCH DAMAGE.
 36 */
 37
 38#include <linux/tipc_config.h>
 39#include "socket.h"
 40#include "msg.h"
 41#include "bcast.h"
 42#include "name_distr.h"
 43#include "link.h"
 44#include "node.h"
 45
 46#define	BCLINK_WIN_DEFAULT	50	/* bcast link window size (default) */
 47#define	BCLINK_WIN_MIN	        32	/* bcast minimum link window size */
 48
 49const char tipc_bclink_name[] = "broadcast-link";
 
 50
 51/**
 52 * struct tipc_bc_base - base structure for keeping broadcast send state
 53 * @link: broadcast send link structure
 54 * @inputq: data input queue; will only carry SOCK_WAKEUP messages
 55 * @dest: array keeping number of reachable destinations per bearer
 56 * @primary_bearer: a bearer having links to all broadcast destinations, if any
 
 
 
 
 
 
 57 */
 58struct tipc_bc_base {
 59	struct tipc_link *link;
 60	struct sk_buff_head inputq;
 61	int dests[MAX_BEARERS];
 62	int primary_bearer;
 
 
 
 
 
 
 63};
 64
 65static struct tipc_bc_base *tipc_bc_base(struct net *net)
 66{
 67	return tipc_net(net)->bcbase;
 68}
 69
 
 
 
 
 70int tipc_bcast_get_mtu(struct net *net)
 71{
 72	return tipc_link_mtu(tipc_bc_sndlink(net));
 
 
 
 
 
 
 
 
 
 
 
 
 
 73}
 74
 75/* tipc_bcbase_select_primary(): find a bearer with links to all destinations,
 76 *                               if any, and make it primary bearer
 77 */
 78static void tipc_bcbase_select_primary(struct net *net)
 79{
 80	struct tipc_bc_base *bb = tipc_bc_base(net);
 81	int all_dests =  tipc_link_bc_peers(bb->link);
 82	int i, mtu;
 83
 84	bb->primary_bearer = INVALID_BEARER_ID;
 
 85
 86	if (!all_dests)
 87		return;
 88
 89	for (i = 0; i < MAX_BEARERS; i++) {
 90		if (!bb->dests[i])
 91			continue;
 92
 93		mtu = tipc_bearer_mtu(net, i);
 94		if (mtu < tipc_link_mtu(bb->link))
 95			tipc_link_set_mtu(bb->link, mtu);
 96
 97		if (bb->dests[i] < all_dests)
 98			continue;
 99
100		bb->primary_bearer = i;
101
102		/* Reduce risk that all nodes select same primary */
103		if ((i ^ tipc_own_addr(net)) & 1)
104			break;
105	}
 
 
 
106}
107
108void tipc_bcast_inc_bearer_dst_cnt(struct net *net, int bearer_id)
109{
110	struct tipc_bc_base *bb = tipc_bc_base(net);
111
112	tipc_bcast_lock(net);
113	bb->dests[bearer_id]++;
114	tipc_bcbase_select_primary(net);
115	tipc_bcast_unlock(net);
116}
117
118void tipc_bcast_dec_bearer_dst_cnt(struct net *net, int bearer_id)
119{
120	struct tipc_bc_base *bb = tipc_bc_base(net);
121
122	tipc_bcast_lock(net);
123	bb->dests[bearer_id]--;
124	tipc_bcbase_select_primary(net);
125	tipc_bcast_unlock(net);
126}
127
128/* tipc_bcbase_xmit - broadcast a packet queue across one or more bearers
129 *
130 * Note that number of reachable destinations, as indicated in the dests[]
131 * array, may transitionally differ from the number of destinations indicated
132 * in each sent buffer. We can sustain this. Excess destination nodes will
133 * drop and never acknowledge the unexpected packets, and missing destinations
134 * will either require retransmission (if they are just about to be added to
135 * the bearer), or be removed from the buffer's 'ackers' counter (if they
136 * just went down)
137 */
138static void tipc_bcbase_xmit(struct net *net, struct sk_buff_head *xmitq)
139{
140	int bearer_id;
141	struct tipc_bc_base *bb = tipc_bc_base(net);
142	struct sk_buff *skb, *_skb;
143	struct sk_buff_head _xmitq;
144
145	if (skb_queue_empty(xmitq))
146		return;
147
148	/* The typical case: at least one bearer has links to all nodes */
149	bearer_id = bb->primary_bearer;
150	if (bearer_id >= 0) {
151		tipc_bearer_bc_xmit(net, bearer_id, xmitq);
152		return;
153	}
154
155	/* We have to transmit across all bearers */
156	skb_queue_head_init(&_xmitq);
157	for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
158		if (!bb->dests[bearer_id])
159			continue;
160
161		skb_queue_walk(xmitq, skb) {
162			_skb = pskb_copy_for_clone(skb, GFP_ATOMIC);
163			if (!_skb)
164				break;
165			__skb_queue_tail(&_xmitq, _skb);
166		}
167		tipc_bearer_bc_xmit(net, bearer_id, &_xmitq);
168	}
169	__skb_queue_purge(xmitq);
170	__skb_queue_purge(&_xmitq);
171}
172
173/* tipc_bcast_xmit - deliver buffer chain to all nodes in cluster
174 *                    and to identified node local sockets
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
175 * @net: the applicable net namespace
176 * @list: chain of buffers containing message
177 * Consumes the buffer chain, except when returning -ELINKCONG
178 * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
 
179 */
180int tipc_bcast_xmit(struct net *net, struct sk_buff_head *list)
 
181{
182	struct tipc_link *l = tipc_bc_sndlink(net);
183	struct sk_buff_head xmitq, inputq, rcvq;
184	int rc = 0;
185
186	__skb_queue_head_init(&rcvq);
187	__skb_queue_head_init(&xmitq);
188	skb_queue_head_init(&inputq);
189
190	/* Prepare message clone for local node */
191	if (unlikely(!tipc_msg_reassemble(list, &rcvq)))
192		return -EHOSTUNREACH;
193
194	tipc_bcast_lock(net);
195	if (tipc_link_bc_peers(l))
196		rc = tipc_link_xmit(l, list, &xmitq);
197	tipc_bcast_unlock(net);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
198
199	/* Don't send to local node if adding to link failed */
200	if (unlikely(rc)) {
201		__skb_queue_purge(&rcvq);
202		return rc;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
203	}
204
205	/* Broadcast to all nodes, inluding local node */
206	tipc_bcbase_xmit(net, &xmitq);
207	tipc_sk_mcast_rcv(net, &rcvq, &inputq);
208	__skb_queue_purge(list);
209	return 0;
 
 
 
210}
211
212/* tipc_bcast_rcv - receive a broadcast packet, and deliver to rcv link
213 *
214 * RCU is locked, no other locks set
215 */
216int tipc_bcast_rcv(struct net *net, struct tipc_link *l, struct sk_buff *skb)
217{
218	struct tipc_msg *hdr = buf_msg(skb);
219	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
220	struct sk_buff_head xmitq;
221	int rc;
222
223	__skb_queue_head_init(&xmitq);
224
225	if (msg_mc_netid(hdr) != tipc_netid(net) || !tipc_link_is_up(l)) {
226		kfree_skb(skb);
227		return 0;
228	}
229
230	tipc_bcast_lock(net);
231	if (msg_user(hdr) == BCAST_PROTOCOL)
232		rc = tipc_link_bc_nack_rcv(l, skb, &xmitq);
233	else
234		rc = tipc_link_rcv(l, skb, NULL);
235	tipc_bcast_unlock(net);
236
237	tipc_bcbase_xmit(net, &xmitq);
238
239	/* Any socket wakeup messages ? */
240	if (!skb_queue_empty(inputq))
241		tipc_sk_rcv(net, inputq);
242
243	return rc;
244}
245
246/* tipc_bcast_ack_rcv - receive and handle a broadcast acknowledge
247 *
248 * RCU is locked, no other locks set
249 */
250void tipc_bcast_ack_rcv(struct net *net, struct tipc_link *l, u32 acked)
 
251{
252	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
 
253	struct sk_buff_head xmitq;
254
 
 
 
 
255	__skb_queue_head_init(&xmitq);
256
257	tipc_bcast_lock(net);
258	tipc_link_bc_ack_rcv(l, acked, &xmitq);
259	tipc_bcast_unlock(net);
260
261	tipc_bcbase_xmit(net, &xmitq);
262
263	/* Any socket wakeup messages ? */
264	if (!skb_queue_empty(inputq))
265		tipc_sk_rcv(net, inputq);
266}
267
268/* tipc_bcast_synch_rcv -  check and update rcv link with peer's send state
269 *
270 * RCU is locked, no other locks set
271 */
272void tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l,
273			 struct tipc_msg *hdr)
 
274{
275	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
 
276	struct sk_buff_head xmitq;
 
277
278	__skb_queue_head_init(&xmitq);
279
280	tipc_bcast_lock(net);
281	if (msg_type(hdr) == STATE_MSG) {
282		tipc_link_bc_ack_rcv(l, msg_bcast_ack(hdr), &xmitq);
283		tipc_link_bc_sync_rcv(l, hdr, &xmitq);
284	} else {
285		tipc_link_bc_init_rcv(l, hdr);
 
 
 
 
 
 
 
 
286	}
287	tipc_bcast_unlock(net);
288
289	tipc_bcbase_xmit(net, &xmitq);
290
291	/* Any socket wakeup messages ? */
292	if (!skb_queue_empty(inputq))
293		tipc_sk_rcv(net, inputq);
 
294}
295
296/* tipc_bcast_add_peer - add a peer node to broadcast link and bearer
297 *
298 * RCU is locked, node lock is set
299 */
300void tipc_bcast_add_peer(struct net *net, struct tipc_link *uc_l,
301			 struct sk_buff_head *xmitq)
302{
303	struct tipc_link *snd_l = tipc_bc_sndlink(net);
304
305	tipc_bcast_lock(net);
306	tipc_link_add_bc_peer(snd_l, uc_l, xmitq);
307	tipc_bcbase_select_primary(net);
 
308	tipc_bcast_unlock(net);
309}
310
311/* tipc_bcast_remove_peer - remove a peer node from broadcast link and bearer
312 *
313 * RCU is locked, node lock is set
314 */
315void tipc_bcast_remove_peer(struct net *net, struct tipc_link *rcv_l)
316{
317	struct tipc_link *snd_l = tipc_bc_sndlink(net);
318	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
319	struct sk_buff_head xmitq;
320
321	__skb_queue_head_init(&xmitq);
322
323	tipc_bcast_lock(net);
324	tipc_link_remove_bc_peer(snd_l, rcv_l, &xmitq);
325	tipc_bcbase_select_primary(net);
 
326	tipc_bcast_unlock(net);
327
328	tipc_bcbase_xmit(net, &xmitq);
329
330	/* Any socket wakeup messages ? */
331	if (!skb_queue_empty(inputq))
332		tipc_sk_rcv(net, inputq);
333}
334
335int tipc_bclink_reset_stats(struct net *net)
336{
337	struct tipc_link *l = tipc_bc_sndlink(net);
338
339	if (!l)
340		return -ENOPROTOOPT;
341
342	tipc_bcast_lock(net);
343	tipc_link_reset_stats(l);
344	tipc_bcast_unlock(net);
345	return 0;
346}
347
348static int tipc_bc_link_set_queue_limits(struct net *net, u32 limit)
349{
350	struct tipc_link *l = tipc_bc_sndlink(net);
351
352	if (!l)
353		return -ENOPROTOOPT;
354	if (limit < BCLINK_WIN_MIN)
355		limit = BCLINK_WIN_MIN;
356	if (limit > TIPC_MAX_LINK_WIN)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
357		return -EINVAL;
 
 
358	tipc_bcast_lock(net);
359	tipc_link_set_queue_limits(l, limit);
360	tipc_bcast_unlock(net);
 
361	return 0;
362}
363
364int tipc_nl_bc_link_set(struct net *net, struct nlattr *attrs[])
365{
366	int err;
367	u32 win;
 
 
368	struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
369
370	if (!attrs[TIPC_NLA_LINK_PROP])
371		return -EINVAL;
372
373	err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP], props);
374	if (err)
375		return err;
376
377	if (!props[TIPC_NLA_PROP_WIN])
 
 
378		return -EOPNOTSUPP;
 
379
380	win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
 
 
 
381
382	return tipc_bc_link_set_queue_limits(net, win);
 
 
 
 
 
 
 
 
 
 
383}
384
385int tipc_bcast_init(struct net *net)
386{
387	struct tipc_net *tn = tipc_net(net);
388	struct tipc_bc_base *bb = NULL;
389	struct tipc_link *l = NULL;
390
391	bb = kzalloc(sizeof(*bb), GFP_ATOMIC);
392	if (!bb)
393		goto enomem;
394	tn->bcbase = bb;
395	spin_lock_init(&tipc_net(net)->bclock);
396
397	if (!tipc_link_bc_create(net, 0, 0,
398				 U16_MAX,
 
399				 BCLINK_WIN_DEFAULT,
400				 0,
401				 &bb->inputq,
402				 NULL,
403				 NULL,
404				 &l))
405		goto enomem;
406	bb->link = l;
407	tn->bcl = l;
 
 
408	return 0;
409enomem:
410	kfree(bb);
411	kfree(l);
412	return -ENOMEM;
413}
414
415void tipc_bcast_stop(struct net *net)
416{
417	struct tipc_net *tn = net_generic(net, tipc_net_id);
418
419	synchronize_net();
420	kfree(tn->bcbase);
421	kfree(tn->bcl);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
422}