xref: /openbmc/linux/net/tipc/link.c (revision 35c55c9877f8de0ab129fa1a309271d0ecc868b9)
1 /*
2  * net/tipc/link.c: TIPC link code
3  *
4  * Copyright (c) 1996-2007, 2012-2016, Ericsson AB
5  * Copyright (c) 2004-2007, 2010-2013, Wind River Systems
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the names of the copyright holders nor the names of its
17  *    contributors may be used to endorse or promote products derived from
18  *    this software without specific prior written permission.
19  *
20  * Alternatively, this software may be distributed under the terms of the
21  * GNU General Public License ("GPL") version 2 as published by the Free
22  * Software Foundation.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34  * POSSIBILITY OF SUCH DAMAGE.
35  */
36 
37 #include "core.h"
38 #include "subscr.h"
39 #include "link.h"
40 #include "bcast.h"
41 #include "socket.h"
42 #include "name_distr.h"
43 #include "discover.h"
44 #include "netlink.h"
45 #include "monitor.h"
46 
47 #include <linux/pkt_sched.h>
48 
49 struct tipc_stats {
50 	u32 sent_info;		/* used in counting # sent packets */
51 	u32 recv_info;		/* used in counting # recv'd packets */
52 	u32 sent_states;
53 	u32 recv_states;
54 	u32 sent_probes;
55 	u32 recv_probes;
56 	u32 sent_nacks;
57 	u32 recv_nacks;
58 	u32 sent_acks;
59 	u32 sent_bundled;
60 	u32 sent_bundles;
61 	u32 recv_bundled;
62 	u32 recv_bundles;
63 	u32 retransmitted;
64 	u32 sent_fragmented;
65 	u32 sent_fragments;
66 	u32 recv_fragmented;
67 	u32 recv_fragments;
68 	u32 link_congs;		/* # port sends blocked by congestion */
69 	u32 deferred_recv;
70 	u32 duplicates;
71 	u32 max_queue_sz;	/* send queue size high water mark */
72 	u32 accu_queue_sz;	/* used for send queue size profiling */
73 	u32 queue_sz_counts;	/* used for send queue size profiling */
74 	u32 msg_length_counts;	/* used for message length profiling */
75 	u32 msg_lengths_total;	/* used for message length profiling */
76 	u32 msg_length_profile[7]; /* used for msg. length profiling */
77 };
78 
79 /**
80  * struct tipc_link - TIPC link data structure
81  * @addr: network address of link's peer node
82  * @name: link name character string
83  * @media_addr: media address to use when sending messages over link
84  * @timer: link timer
85  * @net: pointer to namespace struct
86  * @refcnt: reference counter for permanent references (owner node & timer)
87  * @peer_session: link session # being used by peer end of link
88  * @peer_bearer_id: bearer id used by link's peer endpoint
89  * @bearer_id: local bearer id used by link
90  * @tolerance: minimum link continuity loss needed to reset link [in ms]
91  * @abort_limit: # of unacknowledged continuity probes needed to reset link
92  * @state: current state of link FSM
93  * @peer_caps: bitmap describing capabilities of peer node
94  * @silent_intv_cnt: # of timer intervals without any reception from peer
95  * @proto_msg: template for control messages generated by link
96  * @pmsg: convenience pointer to "proto_msg" field
97  * @priority: current link priority
98  * @net_plane: current link network plane ('A' through 'H')
99  * @mon_state: cookie with information needed by link monitor
100  * @backlog_limit: backlog queue congestion thresholds (indexed by importance)
101  * @exp_msg_count: # of tunnelled messages expected during link changeover
102  * @reset_rcv_checkpt: seq # of last acknowledged message at time of link reset
103  * @mtu: current maximum packet size for this link
104  * @advertised_mtu: advertised own mtu when link is being established
105  * @transmitq: queue for sent, non-acked messages
106  * @backlogq: queue for messages waiting to be sent
107  * @snt_nxt: next sequence number to use for outbound messages
108  * @last_retransmitted: sequence number of most recently retransmitted message
109  * @stale_count: # of identical retransmit requests made by peer
110  * @ackers: # of peers that needs to ack each packet before it can be released
111  * @acked: # last packet acked by a certain peer. Used for broadcast.
112  * @rcv_nxt: next sequence number to expect for inbound messages
113  * @deferred_queue: deferred queue saved OOS b'cast message received from node
114  * @unacked_window: # of inbound messages rx'd without ack'ing back to peer
115  * @inputq: buffer queue for messages to be delivered upwards
116  * @namedq: buffer queue for name table messages to be delivered upwards
117  * @next_out: ptr to first unsent outbound message in queue
118  * @wakeupq: linked list of wakeup msgs waiting for link congestion to abate
119  * @long_msg_seq_no: next identifier to use for outbound fragmented messages
120  * @reasm_buf: head of partially reassembled inbound message fragments
121  * @bc_rcvr: marks that this is a broadcast receiver link
122  * @stats: collects statistics regarding link activity
123  */
124 struct tipc_link {
125 	u32 addr;
126 	char name[TIPC_MAX_LINK_NAME];
127 	struct net *net;
128 
129 	/* Management and link supervision data */
130 	u32 peer_session;
131 	u32 session;
132 	u32 peer_bearer_id;
133 	u32 bearer_id;
134 	u32 tolerance;
135 	u32 abort_limit;
136 	u32 state;
137 	u16 peer_caps;
138 	bool active;
139 	u32 silent_intv_cnt;
140 	char if_name[TIPC_MAX_IF_NAME];
141 	u32 priority;
142 	char net_plane;
143 	struct tipc_mon_state mon_state;
144 	u16 rst_cnt;
145 
146 	/* Failover/synch */
147 	u16 drop_point;
148 	struct sk_buff *failover_reasm_skb;
149 
150 	/* Max packet negotiation */
151 	u16 mtu;
152 	u16 advertised_mtu;
153 
154 	/* Sending */
155 	struct sk_buff_head transmq;
156 	struct sk_buff_head backlogq;
157 	struct {
158 		u16 len;
159 		u16 limit;
160 	} backlog[5];
161 	u16 snd_nxt;
162 	u16 last_retransm;
163 	u16 window;
164 	u32 stale_count;
165 
166 	/* Reception */
167 	u16 rcv_nxt;
168 	u32 rcv_unacked;
169 	struct sk_buff_head deferdq;
170 	struct sk_buff_head *inputq;
171 	struct sk_buff_head *namedq;
172 
173 	/* Congestion handling */
174 	struct sk_buff_head wakeupq;
175 
176 	/* Fragmentation/reassembly */
177 	struct sk_buff *reasm_buf;
178 
179 	/* Broadcast */
180 	u16 ackers;
181 	u16 acked;
182 	struct tipc_link *bc_rcvlink;
183 	struct tipc_link *bc_sndlink;
184 	int nack_state;
185 	bool bc_peer_is_up;
186 
187 	/* Statistics */
188 	struct tipc_stats stats;
189 };
190 
191 /*
192  * Error message prefixes
193  */
194 static const char *link_co_err = "Link tunneling error, ";
195 static const char *link_rst_msg = "Resetting link ";
196 
197 /* Send states for broadcast NACKs
198  */
199 enum {
200 	BC_NACK_SND_CONDITIONAL,
201 	BC_NACK_SND_UNCONDITIONAL,
202 	BC_NACK_SND_SUPPRESS,
203 };
204 
205 /*
206  * Interval between NACKs when packets arrive out of order
207  */
208 #define TIPC_NACK_INTV (TIPC_MIN_LINK_WIN * 2)
209 
210 /* Wildcard value for link session numbers. When it is known that
211  * peer endpoint is down, any session number must be accepted.
212  */
213 #define ANY_SESSION 0x10000
214 
215 /* Link FSM states:
216  */
217 enum {
218 	LINK_ESTABLISHED     = 0xe,
219 	LINK_ESTABLISHING    = 0xe  << 4,
220 	LINK_RESET           = 0x1  << 8,
221 	LINK_RESETTING       = 0x2  << 12,
222 	LINK_PEER_RESET      = 0xd  << 16,
223 	LINK_FAILINGOVER     = 0xf  << 20,
224 	LINK_SYNCHING        = 0xc  << 24
225 };
226 
227 /* Link FSM state checking routines
228  */
229 static int link_is_up(struct tipc_link *l)
230 {
231 	return l->state & (LINK_ESTABLISHED | LINK_SYNCHING);
232 }
233 
234 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
235 			       struct sk_buff_head *xmitq);
236 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
237 				      u16 rcvgap, int tolerance, int priority,
238 				      struct sk_buff_head *xmitq);
239 static void link_print(struct tipc_link *l, const char *str);
240 static void tipc_link_build_nack_msg(struct tipc_link *l,
241 				     struct sk_buff_head *xmitq);
242 static void tipc_link_build_bc_init_msg(struct tipc_link *l,
243 					struct sk_buff_head *xmitq);
244 static bool tipc_link_release_pkts(struct tipc_link *l, u16 to);
245 
246 /*
247  *  Simple non-static link routines (i.e. referenced outside this file)
248  */
249 bool tipc_link_is_up(struct tipc_link *l)
250 {
251 	return link_is_up(l);
252 }
253 
254 bool tipc_link_peer_is_down(struct tipc_link *l)
255 {
256 	return l->state == LINK_PEER_RESET;
257 }
258 
259 bool tipc_link_is_reset(struct tipc_link *l)
260 {
261 	return l->state & (LINK_RESET | LINK_FAILINGOVER | LINK_ESTABLISHING);
262 }
263 
264 bool tipc_link_is_establishing(struct tipc_link *l)
265 {
266 	return l->state == LINK_ESTABLISHING;
267 }
268 
269 bool tipc_link_is_synching(struct tipc_link *l)
270 {
271 	return l->state == LINK_SYNCHING;
272 }
273 
274 bool tipc_link_is_failingover(struct tipc_link *l)
275 {
276 	return l->state == LINK_FAILINGOVER;
277 }
278 
279 bool tipc_link_is_blocked(struct tipc_link *l)
280 {
281 	return l->state & (LINK_RESETTING | LINK_PEER_RESET | LINK_FAILINGOVER);
282 }
283 
284 static bool link_is_bc_sndlink(struct tipc_link *l)
285 {
286 	return !l->bc_sndlink;
287 }
288 
289 static bool link_is_bc_rcvlink(struct tipc_link *l)
290 {
291 	return ((l->bc_rcvlink == l) && !link_is_bc_sndlink(l));
292 }
293 
294 int tipc_link_is_active(struct tipc_link *l)
295 {
296 	return l->active;
297 }
298 
299 void tipc_link_set_active(struct tipc_link *l, bool active)
300 {
301 	l->active = active;
302 }
303 
304 u32 tipc_link_id(struct tipc_link *l)
305 {
306 	return l->peer_bearer_id << 16 | l->bearer_id;
307 }
308 
309 int tipc_link_window(struct tipc_link *l)
310 {
311 	return l->window;
312 }
313 
314 int tipc_link_prio(struct tipc_link *l)
315 {
316 	return l->priority;
317 }
318 
319 unsigned long tipc_link_tolerance(struct tipc_link *l)
320 {
321 	return l->tolerance;
322 }
323 
324 struct sk_buff_head *tipc_link_inputq(struct tipc_link *l)
325 {
326 	return l->inputq;
327 }
328 
329 char tipc_link_plane(struct tipc_link *l)
330 {
331 	return l->net_plane;
332 }
333 
334 void tipc_link_add_bc_peer(struct tipc_link *snd_l,
335 			   struct tipc_link *uc_l,
336 			   struct sk_buff_head *xmitq)
337 {
338 	struct tipc_link *rcv_l = uc_l->bc_rcvlink;
339 
340 	snd_l->ackers++;
341 	rcv_l->acked = snd_l->snd_nxt - 1;
342 	snd_l->state = LINK_ESTABLISHED;
343 	tipc_link_build_bc_init_msg(uc_l, xmitq);
344 }
345 
346 void tipc_link_remove_bc_peer(struct tipc_link *snd_l,
347 			      struct tipc_link *rcv_l,
348 			      struct sk_buff_head *xmitq)
349 {
350 	u16 ack = snd_l->snd_nxt - 1;
351 
352 	snd_l->ackers--;
353 	tipc_link_bc_ack_rcv(rcv_l, ack, xmitq);
354 	tipc_link_reset(rcv_l);
355 	rcv_l->state = LINK_RESET;
356 	if (!snd_l->ackers) {
357 		tipc_link_reset(snd_l);
358 		snd_l->state = LINK_RESET;
359 		__skb_queue_purge(xmitq);
360 	}
361 }
362 
363 int tipc_link_bc_peers(struct tipc_link *l)
364 {
365 	return l->ackers;
366 }
367 
368 void tipc_link_set_mtu(struct tipc_link *l, int mtu)
369 {
370 	l->mtu = mtu;
371 }
372 
373 int tipc_link_mtu(struct tipc_link *l)
374 {
375 	return l->mtu;
376 }
377 
378 u16 tipc_link_rcv_nxt(struct tipc_link *l)
379 {
380 	return l->rcv_nxt;
381 }
382 
383 u16 tipc_link_acked(struct tipc_link *l)
384 {
385 	return l->acked;
386 }
387 
388 char *tipc_link_name(struct tipc_link *l)
389 {
390 	return l->name;
391 }
392 
393 /**
394  * tipc_link_create - create a new link
395  * @n: pointer to associated node
396  * @if_name: associated interface name
397  * @bearer_id: id (index) of associated bearer
398  * @tolerance: link tolerance to be used by link
399  * @net_plane: network plane (A,B,c..) this link belongs to
400  * @mtu: mtu to be advertised by link
401  * @priority: priority to be used by link
402  * @window: send window to be used by link
403  * @session: session to be used by link
404  * @ownnode: identity of own node
405  * @peer: node id of peer node
406  * @peer_caps: bitmap describing peer node capabilities
407  * @bc_sndlink: the namespace global link used for broadcast sending
408  * @bc_rcvlink: the peer specific link used for broadcast reception
409  * @inputq: queue to put messages ready for delivery
410  * @namedq: queue to put binding table update messages ready for delivery
411  * @link: return value, pointer to put the created link
412  *
413  * Returns true if link was created, otherwise false
414  */
415 bool tipc_link_create(struct net *net, char *if_name, int bearer_id,
416 		      int tolerance, char net_plane, u32 mtu, int priority,
417 		      int window, u32 session, u32 ownnode, u32 peer,
418 		      u16 peer_caps,
419 		      struct tipc_link *bc_sndlink,
420 		      struct tipc_link *bc_rcvlink,
421 		      struct sk_buff_head *inputq,
422 		      struct sk_buff_head *namedq,
423 		      struct tipc_link **link)
424 {
425 	struct tipc_link *l;
426 
427 	l = kzalloc(sizeof(*l), GFP_ATOMIC);
428 	if (!l)
429 		return false;
430 	*link = l;
431 	l->session = session;
432 
433 	/* Note: peer i/f name is completed by reset/activate message */
434 	sprintf(l->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
435 		tipc_zone(ownnode), tipc_cluster(ownnode), tipc_node(ownnode),
436 		if_name, tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
437 	strcpy(l->if_name, if_name);
438 	l->addr = peer;
439 	l->peer_caps = peer_caps;
440 	l->net = net;
441 	l->peer_session = ANY_SESSION;
442 	l->bearer_id = bearer_id;
443 	l->tolerance = tolerance;
444 	l->net_plane = net_plane;
445 	l->advertised_mtu = mtu;
446 	l->mtu = mtu;
447 	l->priority = priority;
448 	tipc_link_set_queue_limits(l, window);
449 	l->ackers = 1;
450 	l->bc_sndlink = bc_sndlink;
451 	l->bc_rcvlink = bc_rcvlink;
452 	l->inputq = inputq;
453 	l->namedq = namedq;
454 	l->state = LINK_RESETTING;
455 	__skb_queue_head_init(&l->transmq);
456 	__skb_queue_head_init(&l->backlogq);
457 	__skb_queue_head_init(&l->deferdq);
458 	skb_queue_head_init(&l->wakeupq);
459 	skb_queue_head_init(l->inputq);
460 	return true;
461 }
462 
463 /**
464  * tipc_link_bc_create - create new link to be used for broadcast
465  * @n: pointer to associated node
466  * @mtu: mtu to be used
467  * @window: send window to be used
468  * @inputq: queue to put messages ready for delivery
469  * @namedq: queue to put binding table update messages ready for delivery
470  * @link: return value, pointer to put the created link
471  *
472  * Returns true if link was created, otherwise false
473  */
474 bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer,
475 			 int mtu, int window, u16 peer_caps,
476 			 struct sk_buff_head *inputq,
477 			 struct sk_buff_head *namedq,
478 			 struct tipc_link *bc_sndlink,
479 			 struct tipc_link **link)
480 {
481 	struct tipc_link *l;
482 
483 	if (!tipc_link_create(net, "", MAX_BEARERS, 0, 'Z', mtu, 0, window,
484 			      0, ownnode, peer, peer_caps, bc_sndlink,
485 			      NULL, inputq, namedq, link))
486 		return false;
487 
488 	l = *link;
489 	strcpy(l->name, tipc_bclink_name);
490 	tipc_link_reset(l);
491 	l->state = LINK_RESET;
492 	l->ackers = 0;
493 	l->bc_rcvlink = l;
494 
495 	/* Broadcast send link is always up */
496 	if (link_is_bc_sndlink(l))
497 		l->state = LINK_ESTABLISHED;
498 
499 	return true;
500 }
501 
502 /**
503  * tipc_link_fsm_evt - link finite state machine
504  * @l: pointer to link
505  * @evt: state machine event to be processed
506  */
507 int tipc_link_fsm_evt(struct tipc_link *l, int evt)
508 {
509 	int rc = 0;
510 
511 	switch (l->state) {
512 	case LINK_RESETTING:
513 		switch (evt) {
514 		case LINK_PEER_RESET_EVT:
515 			l->state = LINK_PEER_RESET;
516 			break;
517 		case LINK_RESET_EVT:
518 			l->state = LINK_RESET;
519 			break;
520 		case LINK_FAILURE_EVT:
521 		case LINK_FAILOVER_BEGIN_EVT:
522 		case LINK_ESTABLISH_EVT:
523 		case LINK_FAILOVER_END_EVT:
524 		case LINK_SYNCH_BEGIN_EVT:
525 		case LINK_SYNCH_END_EVT:
526 		default:
527 			goto illegal_evt;
528 		}
529 		break;
530 	case LINK_RESET:
531 		switch (evt) {
532 		case LINK_PEER_RESET_EVT:
533 			l->state = LINK_ESTABLISHING;
534 			break;
535 		case LINK_FAILOVER_BEGIN_EVT:
536 			l->state = LINK_FAILINGOVER;
537 		case LINK_FAILURE_EVT:
538 		case LINK_RESET_EVT:
539 		case LINK_ESTABLISH_EVT:
540 		case LINK_FAILOVER_END_EVT:
541 			break;
542 		case LINK_SYNCH_BEGIN_EVT:
543 		case LINK_SYNCH_END_EVT:
544 		default:
545 			goto illegal_evt;
546 		}
547 		break;
548 	case LINK_PEER_RESET:
549 		switch (evt) {
550 		case LINK_RESET_EVT:
551 			l->state = LINK_ESTABLISHING;
552 			break;
553 		case LINK_PEER_RESET_EVT:
554 		case LINK_ESTABLISH_EVT:
555 		case LINK_FAILURE_EVT:
556 			break;
557 		case LINK_SYNCH_BEGIN_EVT:
558 		case LINK_SYNCH_END_EVT:
559 		case LINK_FAILOVER_BEGIN_EVT:
560 		case LINK_FAILOVER_END_EVT:
561 		default:
562 			goto illegal_evt;
563 		}
564 		break;
565 	case LINK_FAILINGOVER:
566 		switch (evt) {
567 		case LINK_FAILOVER_END_EVT:
568 			l->state = LINK_RESET;
569 			break;
570 		case LINK_PEER_RESET_EVT:
571 		case LINK_RESET_EVT:
572 		case LINK_ESTABLISH_EVT:
573 		case LINK_FAILURE_EVT:
574 			break;
575 		case LINK_FAILOVER_BEGIN_EVT:
576 		case LINK_SYNCH_BEGIN_EVT:
577 		case LINK_SYNCH_END_EVT:
578 		default:
579 			goto illegal_evt;
580 		}
581 		break;
582 	case LINK_ESTABLISHING:
583 		switch (evt) {
584 		case LINK_ESTABLISH_EVT:
585 			l->state = LINK_ESTABLISHED;
586 			break;
587 		case LINK_FAILOVER_BEGIN_EVT:
588 			l->state = LINK_FAILINGOVER;
589 			break;
590 		case LINK_RESET_EVT:
591 			l->state = LINK_RESET;
592 			break;
593 		case LINK_FAILURE_EVT:
594 		case LINK_PEER_RESET_EVT:
595 		case LINK_SYNCH_BEGIN_EVT:
596 		case LINK_FAILOVER_END_EVT:
597 			break;
598 		case LINK_SYNCH_END_EVT:
599 		default:
600 			goto illegal_evt;
601 		}
602 		break;
603 	case LINK_ESTABLISHED:
604 		switch (evt) {
605 		case LINK_PEER_RESET_EVT:
606 			l->state = LINK_PEER_RESET;
607 			rc |= TIPC_LINK_DOWN_EVT;
608 			break;
609 		case LINK_FAILURE_EVT:
610 			l->state = LINK_RESETTING;
611 			rc |= TIPC_LINK_DOWN_EVT;
612 			break;
613 		case LINK_RESET_EVT:
614 			l->state = LINK_RESET;
615 			break;
616 		case LINK_ESTABLISH_EVT:
617 		case LINK_SYNCH_END_EVT:
618 			break;
619 		case LINK_SYNCH_BEGIN_EVT:
620 			l->state = LINK_SYNCHING;
621 			break;
622 		case LINK_FAILOVER_BEGIN_EVT:
623 		case LINK_FAILOVER_END_EVT:
624 		default:
625 			goto illegal_evt;
626 		}
627 		break;
628 	case LINK_SYNCHING:
629 		switch (evt) {
630 		case LINK_PEER_RESET_EVT:
631 			l->state = LINK_PEER_RESET;
632 			rc |= TIPC_LINK_DOWN_EVT;
633 			break;
634 		case LINK_FAILURE_EVT:
635 			l->state = LINK_RESETTING;
636 			rc |= TIPC_LINK_DOWN_EVT;
637 			break;
638 		case LINK_RESET_EVT:
639 			l->state = LINK_RESET;
640 			break;
641 		case LINK_ESTABLISH_EVT:
642 		case LINK_SYNCH_BEGIN_EVT:
643 			break;
644 		case LINK_SYNCH_END_EVT:
645 			l->state = LINK_ESTABLISHED;
646 			break;
647 		case LINK_FAILOVER_BEGIN_EVT:
648 		case LINK_FAILOVER_END_EVT:
649 		default:
650 			goto illegal_evt;
651 		}
652 		break;
653 	default:
654 		pr_err("Unknown FSM state %x in %s\n", l->state, l->name);
655 	}
656 	return rc;
657 illegal_evt:
658 	pr_err("Illegal FSM event %x in state %x on link %s\n",
659 	       evt, l->state, l->name);
660 	return rc;
661 }
662 
663 /* link_profile_stats - update statistical profiling of traffic
664  */
665 static void link_profile_stats(struct tipc_link *l)
666 {
667 	struct sk_buff *skb;
668 	struct tipc_msg *msg;
669 	int length;
670 
671 	/* Update counters used in statistical profiling of send traffic */
672 	l->stats.accu_queue_sz += skb_queue_len(&l->transmq);
673 	l->stats.queue_sz_counts++;
674 
675 	skb = skb_peek(&l->transmq);
676 	if (!skb)
677 		return;
678 	msg = buf_msg(skb);
679 	length = msg_size(msg);
680 
681 	if (msg_user(msg) == MSG_FRAGMENTER) {
682 		if (msg_type(msg) != FIRST_FRAGMENT)
683 			return;
684 		length = msg_size(msg_get_wrapped(msg));
685 	}
686 	l->stats.msg_lengths_total += length;
687 	l->stats.msg_length_counts++;
688 	if (length <= 64)
689 		l->stats.msg_length_profile[0]++;
690 	else if (length <= 256)
691 		l->stats.msg_length_profile[1]++;
692 	else if (length <= 1024)
693 		l->stats.msg_length_profile[2]++;
694 	else if (length <= 4096)
695 		l->stats.msg_length_profile[3]++;
696 	else if (length <= 16384)
697 		l->stats.msg_length_profile[4]++;
698 	else if (length <= 32768)
699 		l->stats.msg_length_profile[5]++;
700 	else
701 		l->stats.msg_length_profile[6]++;
702 }
703 
704 /* tipc_link_timeout - perform periodic task as instructed from node timeout
705  */
706 int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
707 {
708 	int mtyp, rc = 0;
709 	bool state = false;
710 	bool probe = false;
711 	bool setup = false;
712 	u16 bc_snt = l->bc_sndlink->snd_nxt - 1;
713 	u16 bc_acked = l->bc_rcvlink->acked;
714 	struct tipc_mon_state *mstate = &l->mon_state;
715 
716 	switch (l->state) {
717 	case LINK_ESTABLISHED:
718 	case LINK_SYNCHING:
719 		mtyp = STATE_MSG;
720 		link_profile_stats(l);
721 		tipc_mon_get_state(l->net, l->addr, mstate, l->bearer_id);
722 		if (mstate->reset || (l->silent_intv_cnt > l->abort_limit))
723 			return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
724 		state = bc_acked != bc_snt;
725 		state |= l->bc_rcvlink->rcv_unacked;
726 		state |= l->rcv_unacked;
727 		state |= !skb_queue_empty(&l->transmq);
728 		state |= !skb_queue_empty(&l->deferdq);
729 		probe = mstate->probing;
730 		probe |= l->silent_intv_cnt;
731 		if (probe || mstate->monitoring)
732 			l->silent_intv_cnt++;
733 		break;
734 	case LINK_RESET:
735 		setup = l->rst_cnt++ <= 4;
736 		setup |= !(l->rst_cnt % 16);
737 		mtyp = RESET_MSG;
738 		break;
739 	case LINK_ESTABLISHING:
740 		setup = true;
741 		mtyp = ACTIVATE_MSG;
742 		break;
743 	case LINK_PEER_RESET:
744 	case LINK_RESETTING:
745 	case LINK_FAILINGOVER:
746 		break;
747 	default:
748 		break;
749 	}
750 
751 	if (state || probe || setup)
752 		tipc_link_build_proto_msg(l, mtyp, probe, 0, 0, 0, xmitq);
753 
754 	return rc;
755 }
756 
757 /**
758  * link_schedule_user - schedule a message sender for wakeup after congestion
759  * @link: congested link
760  * @list: message that was attempted sent
761  * Create pseudo msg to send back to user when congestion abates
762  * Does not consume buffer list
763  */
764 static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list)
765 {
766 	struct tipc_msg *msg = buf_msg(skb_peek(list));
767 	int imp = msg_importance(msg);
768 	u32 oport = msg_origport(msg);
769 	u32 addr = tipc_own_addr(link->net);
770 	struct sk_buff *skb;
771 
772 	/* This really cannot happen...  */
773 	if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
774 		pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
775 		return -ENOBUFS;
776 	}
777 	/* Non-blocking sender: */
778 	if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending)
779 		return -ELINKCONG;
780 
781 	/* Create and schedule wakeup pseudo message */
782 	skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
783 			      addr, addr, oport, 0, 0);
784 	if (!skb)
785 		return -ENOBUFS;
786 	TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list);
787 	TIPC_SKB_CB(skb)->chain_imp = imp;
788 	skb_queue_tail(&link->wakeupq, skb);
789 	link->stats.link_congs++;
790 	return -ELINKCONG;
791 }
792 
793 /**
794  * link_prepare_wakeup - prepare users for wakeup after congestion
795  * @link: congested link
796  * Move a number of waiting users, as permitted by available space in
797  * the send queue, from link wait queue to node wait queue for wakeup
798  */
799 void link_prepare_wakeup(struct tipc_link *l)
800 {
801 	int pnd[TIPC_SYSTEM_IMPORTANCE + 1] = {0,};
802 	int imp, lim;
803 	struct sk_buff *skb, *tmp;
804 
805 	skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
806 		imp = TIPC_SKB_CB(skb)->chain_imp;
807 		lim = l->window + l->backlog[imp].limit;
808 		pnd[imp] += TIPC_SKB_CB(skb)->chain_sz;
809 		if ((pnd[imp] + l->backlog[imp].len) >= lim)
810 			break;
811 		skb_unlink(skb, &l->wakeupq);
812 		skb_queue_tail(l->inputq, skb);
813 	}
814 }
815 
816 void tipc_link_reset(struct tipc_link *l)
817 {
818 	l->peer_session = ANY_SESSION;
819 	l->session++;
820 	l->mtu = l->advertised_mtu;
821 	__skb_queue_purge(&l->transmq);
822 	__skb_queue_purge(&l->deferdq);
823 	skb_queue_splice_init(&l->wakeupq, l->inputq);
824 	__skb_queue_purge(&l->backlogq);
825 	l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
826 	l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;
827 	l->backlog[TIPC_HIGH_IMPORTANCE].len = 0;
828 	l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0;
829 	l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0;
830 	kfree_skb(l->reasm_buf);
831 	kfree_skb(l->failover_reasm_skb);
832 	l->reasm_buf = NULL;
833 	l->failover_reasm_skb = NULL;
834 	l->rcv_unacked = 0;
835 	l->snd_nxt = 1;
836 	l->rcv_nxt = 1;
837 	l->acked = 0;
838 	l->silent_intv_cnt = 0;
839 	l->rst_cnt = 0;
840 	l->stats.recv_info = 0;
841 	l->stale_count = 0;
842 	l->bc_peer_is_up = false;
843 	memset(&l->mon_state, 0, sizeof(l->mon_state));
844 	tipc_link_reset_stats(l);
845 }
846 
847 /**
848  * tipc_link_xmit(): enqueue buffer list according to queue situation
849  * @link: link to use
850  * @list: chain of buffers containing message
851  * @xmitq: returned list of packets to be sent by caller
852  *
853  * Consumes the buffer chain, except when returning -ELINKCONG,
854  * since the caller then may want to make more send attempts.
855  * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
856  * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
857  */
858 int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
859 		   struct sk_buff_head *xmitq)
860 {
861 	struct tipc_msg *hdr = buf_msg(skb_peek(list));
862 	unsigned int maxwin = l->window;
863 	unsigned int i, imp = msg_importance(hdr);
864 	unsigned int mtu = l->mtu;
865 	u16 ack = l->rcv_nxt - 1;
866 	u16 seqno = l->snd_nxt;
867 	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
868 	struct sk_buff_head *transmq = &l->transmq;
869 	struct sk_buff_head *backlogq = &l->backlogq;
870 	struct sk_buff *skb, *_skb, *bskb;
871 
872 	/* Match msg importance against this and all higher backlog limits: */
873 	for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
874 		if (unlikely(l->backlog[i].len >= l->backlog[i].limit))
875 			return link_schedule_user(l, list);
876 	}
877 	if (unlikely(msg_size(hdr) > mtu)) {
878 		skb_queue_purge(list);
879 		return -EMSGSIZE;
880 	}
881 
882 	/* Prepare each packet for sending, and add to relevant queue: */
883 	while (skb_queue_len(list)) {
884 		skb = skb_peek(list);
885 		hdr = buf_msg(skb);
886 		msg_set_seqno(hdr, seqno);
887 		msg_set_ack(hdr, ack);
888 		msg_set_bcast_ack(hdr, bc_ack);
889 
890 		if (likely(skb_queue_len(transmq) < maxwin)) {
891 			_skb = skb_clone(skb, GFP_ATOMIC);
892 			if (!_skb) {
893 				skb_queue_purge(list);
894 				return -ENOBUFS;
895 			}
896 			__skb_dequeue(list);
897 			__skb_queue_tail(transmq, skb);
898 			__skb_queue_tail(xmitq, _skb);
899 			TIPC_SKB_CB(skb)->ackers = l->ackers;
900 			l->rcv_unacked = 0;
901 			seqno++;
902 			continue;
903 		}
904 		if (tipc_msg_bundle(skb_peek_tail(backlogq), hdr, mtu)) {
905 			kfree_skb(__skb_dequeue(list));
906 			l->stats.sent_bundled++;
907 			continue;
908 		}
909 		if (tipc_msg_make_bundle(&bskb, hdr, mtu, l->addr)) {
910 			kfree_skb(__skb_dequeue(list));
911 			__skb_queue_tail(backlogq, bskb);
912 			l->backlog[msg_importance(buf_msg(bskb))].len++;
913 			l->stats.sent_bundled++;
914 			l->stats.sent_bundles++;
915 			continue;
916 		}
917 		l->backlog[imp].len += skb_queue_len(list);
918 		skb_queue_splice_tail_init(list, backlogq);
919 	}
920 	l->snd_nxt = seqno;
921 	return 0;
922 }
923 
924 void tipc_link_advance_backlog(struct tipc_link *l, struct sk_buff_head *xmitq)
925 {
926 	struct sk_buff *skb, *_skb;
927 	struct tipc_msg *hdr;
928 	u16 seqno = l->snd_nxt;
929 	u16 ack = l->rcv_nxt - 1;
930 	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
931 
932 	while (skb_queue_len(&l->transmq) < l->window) {
933 		skb = skb_peek(&l->backlogq);
934 		if (!skb)
935 			break;
936 		_skb = skb_clone(skb, GFP_ATOMIC);
937 		if (!_skb)
938 			break;
939 		__skb_dequeue(&l->backlogq);
940 		hdr = buf_msg(skb);
941 		l->backlog[msg_importance(hdr)].len--;
942 		__skb_queue_tail(&l->transmq, skb);
943 		__skb_queue_tail(xmitq, _skb);
944 		TIPC_SKB_CB(skb)->ackers = l->ackers;
945 		msg_set_seqno(hdr, seqno);
946 		msg_set_ack(hdr, ack);
947 		msg_set_bcast_ack(hdr, bc_ack);
948 		l->rcv_unacked = 0;
949 		seqno++;
950 	}
951 	l->snd_nxt = seqno;
952 }
953 
954 static void link_retransmit_failure(struct tipc_link *l, struct sk_buff *skb)
955 {
956 	struct tipc_msg *hdr = buf_msg(skb);
957 
958 	pr_warn("Retransmission failure on link <%s>\n", l->name);
959 	link_print(l, "Resetting link ");
960 	pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
961 		msg_user(hdr), msg_type(hdr), msg_size(hdr), msg_errcode(hdr));
962 	pr_info("sqno %u, prev: %x, src: %x\n",
963 		msg_seqno(hdr), msg_prevnode(hdr), msg_orignode(hdr));
964 }
965 
966 int tipc_link_retrans(struct tipc_link *l, u16 from, u16 to,
967 		      struct sk_buff_head *xmitq)
968 {
969 	struct sk_buff *_skb, *skb = skb_peek(&l->transmq);
970 	struct tipc_msg *hdr;
971 	u16 ack = l->rcv_nxt - 1;
972 	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
973 
974 	if (!skb)
975 		return 0;
976 
977 	/* Detect repeated retransmit failures on same packet */
978 	if (likely(l->last_retransm != buf_seqno(skb))) {
979 		l->last_retransm = buf_seqno(skb);
980 		l->stale_count = 1;
981 	} else if (++l->stale_count > 100) {
982 		link_retransmit_failure(l, skb);
983 		return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
984 	}
985 
986 	/* Move forward to where retransmission should start */
987 	skb_queue_walk(&l->transmq, skb) {
988 		if (!less(buf_seqno(skb), from))
989 			break;
990 	}
991 
992 	skb_queue_walk_from(&l->transmq, skb) {
993 		if (more(buf_seqno(skb), to))
994 			break;
995 		hdr = buf_msg(skb);
996 		_skb = __pskb_copy(skb, MIN_H_SIZE, GFP_ATOMIC);
997 		if (!_skb)
998 			return 0;
999 		hdr = buf_msg(_skb);
1000 		msg_set_ack(hdr, ack);
1001 		msg_set_bcast_ack(hdr, bc_ack);
1002 		_skb->priority = TC_PRIO_CONTROL;
1003 		__skb_queue_tail(xmitq, _skb);
1004 		l->stats.retransmitted++;
1005 	}
1006 	return 0;
1007 }
1008 
1009 /* tipc_data_input - deliver data and name distr msgs to upper layer
1010  *
1011  * Consumes buffer if message is of right type
1012  * Node lock must be held
1013  */
1014 static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb,
1015 			    struct sk_buff_head *inputq)
1016 {
1017 	switch (msg_user(buf_msg(skb))) {
1018 	case TIPC_LOW_IMPORTANCE:
1019 	case TIPC_MEDIUM_IMPORTANCE:
1020 	case TIPC_HIGH_IMPORTANCE:
1021 	case TIPC_CRITICAL_IMPORTANCE:
1022 	case CONN_MANAGER:
1023 		skb_queue_tail(inputq, skb);
1024 		return true;
1025 	case NAME_DISTRIBUTOR:
1026 		l->bc_rcvlink->state = LINK_ESTABLISHED;
1027 		skb_queue_tail(l->namedq, skb);
1028 		return true;
1029 	case MSG_BUNDLER:
1030 	case TUNNEL_PROTOCOL:
1031 	case MSG_FRAGMENTER:
1032 	case BCAST_PROTOCOL:
1033 		return false;
1034 	default:
1035 		pr_warn("Dropping received illegal msg type\n");
1036 		kfree_skb(skb);
1037 		return false;
1038 	};
1039 }
1040 
1041 /* tipc_link_input - process packet that has passed link protocol check
1042  *
1043  * Consumes buffer
1044  */
1045 static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb,
1046 			   struct sk_buff_head *inputq)
1047 {
1048 	struct tipc_msg *hdr = buf_msg(skb);
1049 	struct sk_buff **reasm_skb = &l->reasm_buf;
1050 	struct sk_buff *iskb;
1051 	struct sk_buff_head tmpq;
1052 	int usr = msg_user(hdr);
1053 	int rc = 0;
1054 	int pos = 0;
1055 	int ipos = 0;
1056 
1057 	if (unlikely(usr == TUNNEL_PROTOCOL)) {
1058 		if (msg_type(hdr) == SYNCH_MSG) {
1059 			__skb_queue_purge(&l->deferdq);
1060 			goto drop;
1061 		}
1062 		if (!tipc_msg_extract(skb, &iskb, &ipos))
1063 			return rc;
1064 		kfree_skb(skb);
1065 		skb = iskb;
1066 		hdr = buf_msg(skb);
1067 		if (less(msg_seqno(hdr), l->drop_point))
1068 			goto drop;
1069 		if (tipc_data_input(l, skb, inputq))
1070 			return rc;
1071 		usr = msg_user(hdr);
1072 		reasm_skb = &l->failover_reasm_skb;
1073 	}
1074 
1075 	if (usr == MSG_BUNDLER) {
1076 		skb_queue_head_init(&tmpq);
1077 		l->stats.recv_bundles++;
1078 		l->stats.recv_bundled += msg_msgcnt(hdr);
1079 		while (tipc_msg_extract(skb, &iskb, &pos))
1080 			tipc_data_input(l, iskb, &tmpq);
1081 		tipc_skb_queue_splice_tail(&tmpq, inputq);
1082 		return 0;
1083 	} else if (usr == MSG_FRAGMENTER) {
1084 		l->stats.recv_fragments++;
1085 		if (tipc_buf_append(reasm_skb, &skb)) {
1086 			l->stats.recv_fragmented++;
1087 			tipc_data_input(l, skb, inputq);
1088 		} else if (!*reasm_skb && !link_is_bc_rcvlink(l)) {
1089 			pr_warn_ratelimited("Unable to build fragment list\n");
1090 			return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1091 		}
1092 		return 0;
1093 	} else if (usr == BCAST_PROTOCOL) {
1094 		tipc_bcast_lock(l->net);
1095 		tipc_link_bc_init_rcv(l->bc_rcvlink, hdr);
1096 		tipc_bcast_unlock(l->net);
1097 	}
1098 drop:
1099 	kfree_skb(skb);
1100 	return 0;
1101 }
1102 
1103 static bool tipc_link_release_pkts(struct tipc_link *l, u16 acked)
1104 {
1105 	bool released = false;
1106 	struct sk_buff *skb, *tmp;
1107 
1108 	skb_queue_walk_safe(&l->transmq, skb, tmp) {
1109 		if (more(buf_seqno(skb), acked))
1110 			break;
1111 		__skb_unlink(skb, &l->transmq);
1112 		kfree_skb(skb);
1113 		released = true;
1114 	}
1115 	return released;
1116 }
1117 
1118 /* tipc_link_build_state_msg: prepare link state message for transmission
1119  *
1120  * Note that sending of broadcast ack is coordinated among nodes, to reduce
1121  * risk of ack storms towards the sender
1122  */
1123 int tipc_link_build_state_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1124 {
1125 	if (!l)
1126 		return 0;
1127 
1128 	/* Broadcast ACK must be sent via a unicast link => defer to caller */
1129 	if (link_is_bc_rcvlink(l)) {
1130 		if (((l->rcv_nxt ^ tipc_own_addr(l->net)) & 0xf) != 0xf)
1131 			return 0;
1132 		l->rcv_unacked = 0;
1133 		return TIPC_LINK_SND_BC_ACK;
1134 	}
1135 
1136 	/* Unicast ACK */
1137 	l->rcv_unacked = 0;
1138 	l->stats.sent_acks++;
1139 	tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
1140 	return 0;
1141 }
1142 
1143 /* tipc_link_build_reset_msg: prepare link RESET or ACTIVATE message
1144  */
1145 void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1146 {
1147 	int mtyp = RESET_MSG;
1148 	struct sk_buff *skb;
1149 
1150 	if (l->state == LINK_ESTABLISHING)
1151 		mtyp = ACTIVATE_MSG;
1152 
1153 	tipc_link_build_proto_msg(l, mtyp, 0, 0, 0, 0, xmitq);
1154 
1155 	/* Inform peer that this endpoint is going down if applicable */
1156 	skb = skb_peek_tail(xmitq);
1157 	if (skb && (l->state == LINK_RESET))
1158 		msg_set_peer_stopping(buf_msg(skb), 1);
1159 }
1160 
1161 /* tipc_link_build_nack_msg: prepare link nack message for transmission
1162  */
1163 static void tipc_link_build_nack_msg(struct tipc_link *l,
1164 				     struct sk_buff_head *xmitq)
1165 {
1166 	u32 def_cnt = ++l->stats.deferred_recv;
1167 
1168 	if (link_is_bc_rcvlink(l))
1169 		return;
1170 
1171 	if ((skb_queue_len(&l->deferdq) == 1) || !(def_cnt % TIPC_NACK_INTV))
1172 		tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
1173 }
1174 
1175 /* tipc_link_rcv - process TIPC packets/messages arriving from off-node
1176  * @l: the link that should handle the message
1177  * @skb: TIPC packet
1178  * @xmitq: queue to place packets to be sent after this call
1179  */
1180 int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
1181 		  struct sk_buff_head *xmitq)
1182 {
1183 	struct sk_buff_head *defq = &l->deferdq;
1184 	struct tipc_msg *hdr;
1185 	u16 seqno, rcv_nxt, win_lim;
1186 	int rc = 0;
1187 
1188 	do {
1189 		hdr = buf_msg(skb);
1190 		seqno = msg_seqno(hdr);
1191 		rcv_nxt = l->rcv_nxt;
1192 		win_lim = rcv_nxt + TIPC_MAX_LINK_WIN;
1193 
1194 		/* Verify and update link state */
1195 		if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
1196 			return tipc_link_proto_rcv(l, skb, xmitq);
1197 
1198 		if (unlikely(!link_is_up(l))) {
1199 			if (l->state == LINK_ESTABLISHING)
1200 				rc = TIPC_LINK_UP_EVT;
1201 			goto drop;
1202 		}
1203 
1204 		/* Don't send probe at next timeout expiration */
1205 		l->silent_intv_cnt = 0;
1206 
1207 		/* Drop if outside receive window */
1208 		if (unlikely(less(seqno, rcv_nxt) || more(seqno, win_lim))) {
1209 			l->stats.duplicates++;
1210 			goto drop;
1211 		}
1212 
1213 		/* Forward queues and wake up waiting users */
1214 		if (likely(tipc_link_release_pkts(l, msg_ack(hdr)))) {
1215 			tipc_link_advance_backlog(l, xmitq);
1216 			if (unlikely(!skb_queue_empty(&l->wakeupq)))
1217 				link_prepare_wakeup(l);
1218 		}
1219 
1220 		/* Defer delivery if sequence gap */
1221 		if (unlikely(seqno != rcv_nxt)) {
1222 			__tipc_skb_queue_sorted(defq, seqno, skb);
1223 			tipc_link_build_nack_msg(l, xmitq);
1224 			break;
1225 		}
1226 
1227 		/* Deliver packet */
1228 		l->rcv_nxt++;
1229 		l->stats.recv_info++;
1230 		if (!tipc_data_input(l, skb, l->inputq))
1231 			rc |= tipc_link_input(l, skb, l->inputq);
1232 		if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
1233 			rc |= tipc_link_build_state_msg(l, xmitq);
1234 		if (unlikely(rc & ~TIPC_LINK_SND_BC_ACK))
1235 			break;
1236 	} while ((skb = __skb_dequeue(defq)));
1237 
1238 	return rc;
1239 drop:
1240 	kfree_skb(skb);
1241 	return rc;
1242 }
1243 
1244 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
1245 				      u16 rcvgap, int tolerance, int priority,
1246 				      struct sk_buff_head *xmitq)
1247 {
1248 	struct sk_buff *skb;
1249 	struct tipc_msg *hdr;
1250 	struct sk_buff_head *dfq = &l->deferdq;
1251 	bool node_up = link_is_up(l->bc_rcvlink);
1252 	struct tipc_mon_state *mstate = &l->mon_state;
1253 	int dlen = 0;
1254 	void *data;
1255 
1256 	/* Don't send protocol message during reset or link failover */
1257 	if (tipc_link_is_blocked(l))
1258 		return;
1259 
1260 	if (!tipc_link_is_up(l) && (mtyp == STATE_MSG))
1261 		return;
1262 
1263 	if (!skb_queue_empty(dfq))
1264 		rcvgap = buf_seqno(skb_peek(dfq)) - l->rcv_nxt;
1265 
1266 	skb = tipc_msg_create(LINK_PROTOCOL, mtyp, INT_H_SIZE,
1267 			      tipc_max_domain_size, l->addr,
1268 			      tipc_own_addr(l->net), 0, 0, 0);
1269 	if (!skb)
1270 		return;
1271 
1272 	hdr = buf_msg(skb);
1273 	data = msg_data(hdr);
1274 	msg_set_session(hdr, l->session);
1275 	msg_set_bearer_id(hdr, l->bearer_id);
1276 	msg_set_net_plane(hdr, l->net_plane);
1277 	msg_set_next_sent(hdr, l->snd_nxt);
1278 	msg_set_ack(hdr, l->rcv_nxt - 1);
1279 	msg_set_bcast_ack(hdr, l->bc_rcvlink->rcv_nxt - 1);
1280 	msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
1281 	msg_set_link_tolerance(hdr, tolerance);
1282 	msg_set_linkprio(hdr, priority);
1283 	msg_set_redundant_link(hdr, node_up);
1284 	msg_set_seq_gap(hdr, 0);
1285 	msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2);
1286 
1287 	if (mtyp == STATE_MSG) {
1288 		msg_set_seq_gap(hdr, rcvgap);
1289 		msg_set_probe(hdr, probe);
1290 		tipc_mon_prep(l->net, data, &dlen, mstate, l->bearer_id);
1291 		msg_set_size(hdr, INT_H_SIZE + dlen);
1292 		skb_trim(skb, INT_H_SIZE + dlen);
1293 		l->stats.sent_states++;
1294 		l->rcv_unacked = 0;
1295 	} else {
1296 		/* RESET_MSG or ACTIVATE_MSG */
1297 		msg_set_max_pkt(hdr, l->advertised_mtu);
1298 		strcpy(data, l->if_name);
1299 		msg_set_size(hdr, INT_H_SIZE + TIPC_MAX_IF_NAME);
1300 		skb_trim(skb, INT_H_SIZE + TIPC_MAX_IF_NAME);
1301 	}
1302 	if (probe)
1303 		l->stats.sent_probes++;
1304 	if (rcvgap)
1305 		l->stats.sent_nacks++;
1306 	skb->priority = TC_PRIO_CONTROL;
1307 	__skb_queue_tail(xmitq, skb);
1308 }
1309 
1310 /* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets
1311  * with contents of the link's transmit and backlog queues.
1312  */
1313 void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
1314 			   int mtyp, struct sk_buff_head *xmitq)
1315 {
1316 	struct sk_buff *skb, *tnlskb;
1317 	struct tipc_msg *hdr, tnlhdr;
1318 	struct sk_buff_head *queue = &l->transmq;
1319 	struct sk_buff_head tmpxq, tnlq;
1320 	u16 pktlen, pktcnt, seqno = l->snd_nxt;
1321 
1322 	if (!tnl)
1323 		return;
1324 
1325 	skb_queue_head_init(&tnlq);
1326 	skb_queue_head_init(&tmpxq);
1327 
1328 	/* At least one packet required for safe algorithm => add dummy */
1329 	skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
1330 			      BASIC_H_SIZE, 0, l->addr, tipc_own_addr(l->net),
1331 			      0, 0, TIPC_ERR_NO_PORT);
1332 	if (!skb) {
1333 		pr_warn("%sunable to create tunnel packet\n", link_co_err);
1334 		return;
1335 	}
1336 	skb_queue_tail(&tnlq, skb);
1337 	tipc_link_xmit(l, &tnlq, &tmpxq);
1338 	__skb_queue_purge(&tmpxq);
1339 
1340 	/* Initialize reusable tunnel packet header */
1341 	tipc_msg_init(tipc_own_addr(l->net), &tnlhdr, TUNNEL_PROTOCOL,
1342 		      mtyp, INT_H_SIZE, l->addr);
1343 	pktcnt = skb_queue_len(&l->transmq) + skb_queue_len(&l->backlogq);
1344 	msg_set_msgcnt(&tnlhdr, pktcnt);
1345 	msg_set_bearer_id(&tnlhdr, l->peer_bearer_id);
1346 tnl:
1347 	/* Wrap each packet into a tunnel packet */
1348 	skb_queue_walk(queue, skb) {
1349 		hdr = buf_msg(skb);
1350 		if (queue == &l->backlogq)
1351 			msg_set_seqno(hdr, seqno++);
1352 		pktlen = msg_size(hdr);
1353 		msg_set_size(&tnlhdr, pktlen + INT_H_SIZE);
1354 		tnlskb = tipc_buf_acquire(pktlen + INT_H_SIZE);
1355 		if (!tnlskb) {
1356 			pr_warn("%sunable to send packet\n", link_co_err);
1357 			return;
1358 		}
1359 		skb_copy_to_linear_data(tnlskb, &tnlhdr, INT_H_SIZE);
1360 		skb_copy_to_linear_data_offset(tnlskb, INT_H_SIZE, hdr, pktlen);
1361 		__skb_queue_tail(&tnlq, tnlskb);
1362 	}
1363 	if (queue != &l->backlogq) {
1364 		queue = &l->backlogq;
1365 		goto tnl;
1366 	}
1367 
1368 	tipc_link_xmit(tnl, &tnlq, xmitq);
1369 
1370 	if (mtyp == FAILOVER_MSG) {
1371 		tnl->drop_point = l->rcv_nxt;
1372 		tnl->failover_reasm_skb = l->reasm_buf;
1373 		l->reasm_buf = NULL;
1374 	}
1375 }
1376 
1377 /* tipc_link_proto_rcv(): receive link level protocol message :
1378  * Note that network plane id propagates through the network, and may
1379  * change at any time. The node with lowest numerical id determines
1380  * network plane
1381  */
1382 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
1383 			       struct sk_buff_head *xmitq)
1384 {
1385 	struct tipc_msg *hdr = buf_msg(skb);
1386 	u16 rcvgap = 0;
1387 	u16 ack = msg_ack(hdr);
1388 	u16 gap = msg_seq_gap(hdr);
1389 	u16 peers_snd_nxt =  msg_next_sent(hdr);
1390 	u16 peers_tol = msg_link_tolerance(hdr);
1391 	u16 peers_prio = msg_linkprio(hdr);
1392 	u16 rcv_nxt = l->rcv_nxt;
1393 	u16 dlen = msg_data_sz(hdr);
1394 	int mtyp = msg_type(hdr);
1395 	void *data;
1396 	char *if_name;
1397 	int rc = 0;
1398 
1399 	if (tipc_link_is_blocked(l) || !xmitq)
1400 		goto exit;
1401 
1402 	if (tipc_own_addr(l->net) > msg_prevnode(hdr))
1403 		l->net_plane = msg_net_plane(hdr);
1404 
1405 	skb_linearize(skb);
1406 	hdr = buf_msg(skb);
1407 	data = msg_data(hdr);
1408 
1409 	switch (mtyp) {
1410 	case RESET_MSG:
1411 
1412 		/* Ignore duplicate RESET with old session number */
1413 		if ((less_eq(msg_session(hdr), l->peer_session)) &&
1414 		    (l->peer_session != ANY_SESSION))
1415 			break;
1416 		/* fall thru' */
1417 
1418 	case ACTIVATE_MSG:
1419 
1420 		/* Complete own link name with peer's interface name */
1421 		if_name =  strrchr(l->name, ':') + 1;
1422 		if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME)
1423 			break;
1424 		if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME)
1425 			break;
1426 		strncpy(if_name, data, TIPC_MAX_IF_NAME);
1427 
1428 		/* Update own tolerance if peer indicates a non-zero value */
1429 		if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1430 			l->tolerance = peers_tol;
1431 
1432 		/* Update own priority if peer's priority is higher */
1433 		if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
1434 			l->priority = peers_prio;
1435 
1436 		/* ACTIVATE_MSG serves as PEER_RESET if link is already down */
1437 		if (msg_peer_stopping(hdr))
1438 			rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1439 		else if ((mtyp == RESET_MSG) || !link_is_up(l))
1440 			rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
1441 
1442 		/* ACTIVATE_MSG takes up link if it was already locally reset */
1443 		if ((mtyp == ACTIVATE_MSG) && (l->state == LINK_ESTABLISHING))
1444 			rc = TIPC_LINK_UP_EVT;
1445 
1446 		l->peer_session = msg_session(hdr);
1447 		l->peer_bearer_id = msg_bearer_id(hdr);
1448 		if (l->mtu > msg_max_pkt(hdr))
1449 			l->mtu = msg_max_pkt(hdr);
1450 		break;
1451 
1452 	case STATE_MSG:
1453 
1454 		/* Update own tolerance if peer indicates a non-zero value */
1455 		if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1456 			l->tolerance = peers_tol;
1457 
1458 		if (peers_prio && in_range(peers_prio, TIPC_MIN_LINK_PRI,
1459 					   TIPC_MAX_LINK_PRI)) {
1460 			l->priority = peers_prio;
1461 			rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1462 		}
1463 
1464 		l->silent_intv_cnt = 0;
1465 		l->stats.recv_states++;
1466 		if (msg_probe(hdr))
1467 			l->stats.recv_probes++;
1468 
1469 		if (!link_is_up(l)) {
1470 			if (l->state == LINK_ESTABLISHING)
1471 				rc = TIPC_LINK_UP_EVT;
1472 			break;
1473 		}
1474 		tipc_mon_rcv(l->net, data, dlen, l->addr,
1475 			     &l->mon_state, l->bearer_id);
1476 
1477 		/* Send NACK if peer has sent pkts we haven't received yet */
1478 		if (more(peers_snd_nxt, rcv_nxt) && !tipc_link_is_synching(l))
1479 			rcvgap = peers_snd_nxt - l->rcv_nxt;
1480 		if (rcvgap || (msg_probe(hdr)))
1481 			tipc_link_build_proto_msg(l, STATE_MSG, 0, rcvgap,
1482 						  0, 0, xmitq);
1483 		tipc_link_release_pkts(l, ack);
1484 
1485 		/* If NACK, retransmit will now start at right position */
1486 		if (gap) {
1487 			rc = tipc_link_retrans(l, ack + 1, ack + gap, xmitq);
1488 			l->stats.recv_nacks++;
1489 		}
1490 
1491 		tipc_link_advance_backlog(l, xmitq);
1492 		if (unlikely(!skb_queue_empty(&l->wakeupq)))
1493 			link_prepare_wakeup(l);
1494 	}
1495 exit:
1496 	kfree_skb(skb);
1497 	return rc;
1498 }
1499 
1500 /* tipc_link_build_bc_proto_msg() - create broadcast protocol message
1501  */
1502 static bool tipc_link_build_bc_proto_msg(struct tipc_link *l, bool bcast,
1503 					 u16 peers_snd_nxt,
1504 					 struct sk_buff_head *xmitq)
1505 {
1506 	struct sk_buff *skb;
1507 	struct tipc_msg *hdr;
1508 	struct sk_buff *dfrd_skb = skb_peek(&l->deferdq);
1509 	u16 ack = l->rcv_nxt - 1;
1510 	u16 gap_to = peers_snd_nxt - 1;
1511 
1512 	skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
1513 			      0, l->addr, tipc_own_addr(l->net), 0, 0, 0);
1514 	if (!skb)
1515 		return false;
1516 	hdr = buf_msg(skb);
1517 	msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
1518 	msg_set_bcast_ack(hdr, ack);
1519 	msg_set_bcgap_after(hdr, ack);
1520 	if (dfrd_skb)
1521 		gap_to = buf_seqno(dfrd_skb) - 1;
1522 	msg_set_bcgap_to(hdr, gap_to);
1523 	msg_set_non_seq(hdr, bcast);
1524 	__skb_queue_tail(xmitq, skb);
1525 	return true;
1526 }
1527 
1528 /* tipc_link_build_bc_init_msg() - synchronize broadcast link endpoints.
1529  *
1530  * Give a newly added peer node the sequence number where it should
1531  * start receiving and acking broadcast packets.
1532  */
1533 static void tipc_link_build_bc_init_msg(struct tipc_link *l,
1534 					struct sk_buff_head *xmitq)
1535 {
1536 	struct sk_buff_head list;
1537 
1538 	__skb_queue_head_init(&list);
1539 	if (!tipc_link_build_bc_proto_msg(l->bc_rcvlink, false, 0, &list))
1540 		return;
1541 	tipc_link_xmit(l, &list, xmitq);
1542 }
1543 
1544 /* tipc_link_bc_init_rcv - receive initial broadcast synch data from peer
1545  */
1546 void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr)
1547 {
1548 	int mtyp = msg_type(hdr);
1549 	u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
1550 
1551 	if (link_is_up(l))
1552 		return;
1553 
1554 	if (msg_user(hdr) == BCAST_PROTOCOL) {
1555 		l->rcv_nxt = peers_snd_nxt;
1556 		l->state = LINK_ESTABLISHED;
1557 		return;
1558 	}
1559 
1560 	if (l->peer_caps & TIPC_BCAST_SYNCH)
1561 		return;
1562 
1563 	if (msg_peer_node_is_up(hdr))
1564 		return;
1565 
1566 	/* Compatibility: accept older, less safe initial synch data */
1567 	if ((mtyp == RESET_MSG) || (mtyp == ACTIVATE_MSG))
1568 		l->rcv_nxt = peers_snd_nxt;
1569 }
1570 
1571 /* tipc_link_bc_sync_rcv - update rcv link according to peer's send state
1572  */
1573 void tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
1574 			   struct sk_buff_head *xmitq)
1575 {
1576 	u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
1577 
1578 	if (!link_is_up(l))
1579 		return;
1580 
1581 	if (!msg_peer_node_is_up(hdr))
1582 		return;
1583 
1584 	l->bc_peer_is_up = true;
1585 
1586 	/* Ignore if peers_snd_nxt goes beyond receive window */
1587 	if (more(peers_snd_nxt, l->rcv_nxt + l->window))
1588 		return;
1589 
1590 	if (!more(peers_snd_nxt, l->rcv_nxt)) {
1591 		l->nack_state = BC_NACK_SND_CONDITIONAL;
1592 		return;
1593 	}
1594 
1595 	/* Don't NACK if one was recently sent or peeked */
1596 	if (l->nack_state == BC_NACK_SND_SUPPRESS) {
1597 		l->nack_state = BC_NACK_SND_UNCONDITIONAL;
1598 		return;
1599 	}
1600 
1601 	/* Conditionally delay NACK sending until next synch rcv */
1602 	if (l->nack_state == BC_NACK_SND_CONDITIONAL) {
1603 		l->nack_state = BC_NACK_SND_UNCONDITIONAL;
1604 		if ((peers_snd_nxt - l->rcv_nxt) < TIPC_MIN_LINK_WIN)
1605 			return;
1606 	}
1607 
1608 	/* Send NACK now but suppress next one */
1609 	tipc_link_build_bc_proto_msg(l, true, peers_snd_nxt, xmitq);
1610 	l->nack_state = BC_NACK_SND_SUPPRESS;
1611 }
1612 
1613 void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
1614 			  struct sk_buff_head *xmitq)
1615 {
1616 	struct sk_buff *skb, *tmp;
1617 	struct tipc_link *snd_l = l->bc_sndlink;
1618 
1619 	if (!link_is_up(l) || !l->bc_peer_is_up)
1620 		return;
1621 
1622 	if (!more(acked, l->acked))
1623 		return;
1624 
1625 	/* Skip over packets peer has already acked */
1626 	skb_queue_walk(&snd_l->transmq, skb) {
1627 		if (more(buf_seqno(skb), l->acked))
1628 			break;
1629 	}
1630 
1631 	/* Update/release the packets peer is acking now */
1632 	skb_queue_walk_from_safe(&snd_l->transmq, skb, tmp) {
1633 		if (more(buf_seqno(skb), acked))
1634 			break;
1635 		if (!--TIPC_SKB_CB(skb)->ackers) {
1636 			__skb_unlink(skb, &snd_l->transmq);
1637 			kfree_skb(skb);
1638 		}
1639 	}
1640 	l->acked = acked;
1641 	tipc_link_advance_backlog(snd_l, xmitq);
1642 	if (unlikely(!skb_queue_empty(&snd_l->wakeupq)))
1643 		link_prepare_wakeup(snd_l);
1644 }
1645 
1646 /* tipc_link_bc_nack_rcv(): receive broadcast nack message
1647  */
1648 int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
1649 			  struct sk_buff_head *xmitq)
1650 {
1651 	struct tipc_msg *hdr = buf_msg(skb);
1652 	u32 dnode = msg_destnode(hdr);
1653 	int mtyp = msg_type(hdr);
1654 	u16 acked = msg_bcast_ack(hdr);
1655 	u16 from = acked + 1;
1656 	u16 to = msg_bcgap_to(hdr);
1657 	u16 peers_snd_nxt = to + 1;
1658 	int rc = 0;
1659 
1660 	kfree_skb(skb);
1661 
1662 	if (!tipc_link_is_up(l) || !l->bc_peer_is_up)
1663 		return 0;
1664 
1665 	if (mtyp != STATE_MSG)
1666 		return 0;
1667 
1668 	if (dnode == tipc_own_addr(l->net)) {
1669 		tipc_link_bc_ack_rcv(l, acked, xmitq);
1670 		rc = tipc_link_retrans(l->bc_sndlink, from, to, xmitq);
1671 		l->stats.recv_nacks++;
1672 		return rc;
1673 	}
1674 
1675 	/* Msg for other node => suppress own NACK at next sync if applicable */
1676 	if (more(peers_snd_nxt, l->rcv_nxt) && !less(l->rcv_nxt, from))
1677 		l->nack_state = BC_NACK_SND_SUPPRESS;
1678 
1679 	return 0;
1680 }
1681 
1682 void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
1683 {
1684 	int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE);
1685 
1686 	l->window = win;
1687 	l->backlog[TIPC_LOW_IMPORTANCE].limit      = win / 2;
1688 	l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = win;
1689 	l->backlog[TIPC_HIGH_IMPORTANCE].limit     = win / 2 * 3;
1690 	l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = win * 2;
1691 	l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
1692 }
1693 
1694 /**
1695  * link_reset_stats - reset link statistics
1696  * @l: pointer to link
1697  */
1698 void tipc_link_reset_stats(struct tipc_link *l)
1699 {
1700 	memset(&l->stats, 0, sizeof(l->stats));
1701 	if (!link_is_bc_sndlink(l)) {
1702 		l->stats.sent_info = l->snd_nxt;
1703 		l->stats.recv_info = l->rcv_nxt;
1704 	}
1705 }
1706 
1707 static void link_print(struct tipc_link *l, const char *str)
1708 {
1709 	struct sk_buff *hskb = skb_peek(&l->transmq);
1710 	u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt - 1;
1711 	u16 tail = l->snd_nxt - 1;
1712 
1713 	pr_info("%s Link <%s> state %x\n", str, l->name, l->state);
1714 	pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n",
1715 		skb_queue_len(&l->transmq), head, tail,
1716 		skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt);
1717 }
1718 
1719 /* Parse and validate nested (link) properties valid for media, bearer and link
1720  */
1721 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
1722 {
1723 	int err;
1724 
1725 	err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop,
1726 			       tipc_nl_prop_policy);
1727 	if (err)
1728 		return err;
1729 
1730 	if (props[TIPC_NLA_PROP_PRIO]) {
1731 		u32 prio;
1732 
1733 		prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1734 		if (prio > TIPC_MAX_LINK_PRI)
1735 			return -EINVAL;
1736 	}
1737 
1738 	if (props[TIPC_NLA_PROP_TOL]) {
1739 		u32 tol;
1740 
1741 		tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1742 		if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1743 			return -EINVAL;
1744 	}
1745 
1746 	if (props[TIPC_NLA_PROP_WIN]) {
1747 		u32 win;
1748 
1749 		win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1750 		if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
1751 			return -EINVAL;
1752 	}
1753 
1754 	return 0;
1755 }
1756 
1757 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
1758 {
1759 	int i;
1760 	struct nlattr *stats;
1761 
1762 	struct nla_map {
1763 		u32 key;
1764 		u32 val;
1765 	};
1766 
1767 	struct nla_map map[] = {
1768 		{TIPC_NLA_STATS_RX_INFO, s->recv_info},
1769 		{TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
1770 		{TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
1771 		{TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
1772 		{TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
1773 		{TIPC_NLA_STATS_TX_INFO, s->sent_info},
1774 		{TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
1775 		{TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
1776 		{TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
1777 		{TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
1778 		{TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
1779 			s->msg_length_counts : 1},
1780 		{TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
1781 		{TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
1782 		{TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
1783 		{TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
1784 		{TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
1785 		{TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
1786 		{TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
1787 		{TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
1788 		{TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
1789 		{TIPC_NLA_STATS_RX_STATES, s->recv_states},
1790 		{TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
1791 		{TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
1792 		{TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
1793 		{TIPC_NLA_STATS_TX_STATES, s->sent_states},
1794 		{TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
1795 		{TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
1796 		{TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
1797 		{TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
1798 		{TIPC_NLA_STATS_DUPLICATES, s->duplicates},
1799 		{TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
1800 		{TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
1801 		{TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
1802 			(s->accu_queue_sz / s->queue_sz_counts) : 0}
1803 	};
1804 
1805 	stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
1806 	if (!stats)
1807 		return -EMSGSIZE;
1808 
1809 	for (i = 0; i <  ARRAY_SIZE(map); i++)
1810 		if (nla_put_u32(skb, map[i].key, map[i].val))
1811 			goto msg_full;
1812 
1813 	nla_nest_end(skb, stats);
1814 
1815 	return 0;
1816 msg_full:
1817 	nla_nest_cancel(skb, stats);
1818 
1819 	return -EMSGSIZE;
1820 }
1821 
1822 /* Caller should hold appropriate locks to protect the link */
1823 int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
1824 		       struct tipc_link *link, int nlflags)
1825 {
1826 	int err;
1827 	void *hdr;
1828 	struct nlattr *attrs;
1829 	struct nlattr *prop;
1830 	struct tipc_net *tn = net_generic(net, tipc_net_id);
1831 
1832 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1833 			  nlflags, TIPC_NL_LINK_GET);
1834 	if (!hdr)
1835 		return -EMSGSIZE;
1836 
1837 	attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
1838 	if (!attrs)
1839 		goto msg_full;
1840 
1841 	if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
1842 		goto attr_msg_full;
1843 	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST,
1844 			tipc_cluster_mask(tn->own_addr)))
1845 		goto attr_msg_full;
1846 	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
1847 		goto attr_msg_full;
1848 	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->rcv_nxt))
1849 		goto attr_msg_full;
1850 	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->snd_nxt))
1851 		goto attr_msg_full;
1852 
1853 	if (tipc_link_is_up(link))
1854 		if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
1855 			goto attr_msg_full;
1856 	if (link->active)
1857 		if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
1858 			goto attr_msg_full;
1859 
1860 	prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
1861 	if (!prop)
1862 		goto attr_msg_full;
1863 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
1864 		goto prop_msg_full;
1865 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
1866 		goto prop_msg_full;
1867 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
1868 			link->window))
1869 		goto prop_msg_full;
1870 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
1871 		goto prop_msg_full;
1872 	nla_nest_end(msg->skb, prop);
1873 
1874 	err = __tipc_nl_add_stats(msg->skb, &link->stats);
1875 	if (err)
1876 		goto attr_msg_full;
1877 
1878 	nla_nest_end(msg->skb, attrs);
1879 	genlmsg_end(msg->skb, hdr);
1880 
1881 	return 0;
1882 
1883 prop_msg_full:
1884 	nla_nest_cancel(msg->skb, prop);
1885 attr_msg_full:
1886 	nla_nest_cancel(msg->skb, attrs);
1887 msg_full:
1888 	genlmsg_cancel(msg->skb, hdr);
1889 
1890 	return -EMSGSIZE;
1891 }
1892 
1893 static int __tipc_nl_add_bc_link_stat(struct sk_buff *skb,
1894 				      struct tipc_stats *stats)
1895 {
1896 	int i;
1897 	struct nlattr *nest;
1898 
1899 	struct nla_map {
1900 		__u32 key;
1901 		__u32 val;
1902 	};
1903 
1904 	struct nla_map map[] = {
1905 		{TIPC_NLA_STATS_RX_INFO, stats->recv_info},
1906 		{TIPC_NLA_STATS_RX_FRAGMENTS, stats->recv_fragments},
1907 		{TIPC_NLA_STATS_RX_FRAGMENTED, stats->recv_fragmented},
1908 		{TIPC_NLA_STATS_RX_BUNDLES, stats->recv_bundles},
1909 		{TIPC_NLA_STATS_RX_BUNDLED, stats->recv_bundled},
1910 		{TIPC_NLA_STATS_TX_INFO, stats->sent_info},
1911 		{TIPC_NLA_STATS_TX_FRAGMENTS, stats->sent_fragments},
1912 		{TIPC_NLA_STATS_TX_FRAGMENTED, stats->sent_fragmented},
1913 		{TIPC_NLA_STATS_TX_BUNDLES, stats->sent_bundles},
1914 		{TIPC_NLA_STATS_TX_BUNDLED, stats->sent_bundled},
1915 		{TIPC_NLA_STATS_RX_NACKS, stats->recv_nacks},
1916 		{TIPC_NLA_STATS_RX_DEFERRED, stats->deferred_recv},
1917 		{TIPC_NLA_STATS_TX_NACKS, stats->sent_nacks},
1918 		{TIPC_NLA_STATS_TX_ACKS, stats->sent_acks},
1919 		{TIPC_NLA_STATS_RETRANSMITTED, stats->retransmitted},
1920 		{TIPC_NLA_STATS_DUPLICATES, stats->duplicates},
1921 		{TIPC_NLA_STATS_LINK_CONGS, stats->link_congs},
1922 		{TIPC_NLA_STATS_MAX_QUEUE, stats->max_queue_sz},
1923 		{TIPC_NLA_STATS_AVG_QUEUE, stats->queue_sz_counts ?
1924 			(stats->accu_queue_sz / stats->queue_sz_counts) : 0}
1925 	};
1926 
1927 	nest = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
1928 	if (!nest)
1929 		return -EMSGSIZE;
1930 
1931 	for (i = 0; i <  ARRAY_SIZE(map); i++)
1932 		if (nla_put_u32(skb, map[i].key, map[i].val))
1933 			goto msg_full;
1934 
1935 	nla_nest_end(skb, nest);
1936 
1937 	return 0;
1938 msg_full:
1939 	nla_nest_cancel(skb, nest);
1940 
1941 	return -EMSGSIZE;
1942 }
1943 
1944 int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg)
1945 {
1946 	int err;
1947 	void *hdr;
1948 	struct nlattr *attrs;
1949 	struct nlattr *prop;
1950 	struct tipc_net *tn = net_generic(net, tipc_net_id);
1951 	struct tipc_link *bcl = tn->bcl;
1952 
1953 	if (!bcl)
1954 		return 0;
1955 
1956 	tipc_bcast_lock(net);
1957 
1958 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1959 			  NLM_F_MULTI, TIPC_NL_LINK_GET);
1960 	if (!hdr) {
1961 		tipc_bcast_unlock(net);
1962 		return -EMSGSIZE;
1963 	}
1964 
1965 	attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
1966 	if (!attrs)
1967 		goto msg_full;
1968 
1969 	/* The broadcast link is always up */
1970 	if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
1971 		goto attr_msg_full;
1972 
1973 	if (nla_put_flag(msg->skb, TIPC_NLA_LINK_BROADCAST))
1974 		goto attr_msg_full;
1975 	if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, bcl->name))
1976 		goto attr_msg_full;
1977 	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, bcl->rcv_nxt))
1978 		goto attr_msg_full;
1979 	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, bcl->snd_nxt))
1980 		goto attr_msg_full;
1981 
1982 	prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
1983 	if (!prop)
1984 		goto attr_msg_full;
1985 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bcl->window))
1986 		goto prop_msg_full;
1987 	nla_nest_end(msg->skb, prop);
1988 
1989 	err = __tipc_nl_add_bc_link_stat(msg->skb, &bcl->stats);
1990 	if (err)
1991 		goto attr_msg_full;
1992 
1993 	tipc_bcast_unlock(net);
1994 	nla_nest_end(msg->skb, attrs);
1995 	genlmsg_end(msg->skb, hdr);
1996 
1997 	return 0;
1998 
1999 prop_msg_full:
2000 	nla_nest_cancel(msg->skb, prop);
2001 attr_msg_full:
2002 	nla_nest_cancel(msg->skb, attrs);
2003 msg_full:
2004 	tipc_bcast_unlock(net);
2005 	genlmsg_cancel(msg->skb, hdr);
2006 
2007 	return -EMSGSIZE;
2008 }
2009 
2010 void tipc_link_set_tolerance(struct tipc_link *l, u32 tol,
2011 			     struct sk_buff_head *xmitq)
2012 {
2013 	l->tolerance = tol;
2014 	tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, tol, 0, xmitq);
2015 }
2016 
2017 void tipc_link_set_prio(struct tipc_link *l, u32 prio,
2018 			struct sk_buff_head *xmitq)
2019 {
2020 	l->priority = prio;
2021 	tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, prio, xmitq);
2022 }
2023 
2024 void tipc_link_set_abort_limit(struct tipc_link *l, u32 limit)
2025 {
2026 	l->abort_limit = limit;
2027 }
2028