xref: /kernel/linux/linux-6.6/net/tipc/link.c (revision 62306a36)
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#include "trace.h"
47#include "crypto.h"
48
49#include <linux/pkt_sched.h>
50
51struct tipc_stats {
52	u32 sent_pkts;
53	u32 recv_pkts;
54	u32 sent_states;
55	u32 recv_states;
56	u32 sent_probes;
57	u32 recv_probes;
58	u32 sent_nacks;
59	u32 recv_nacks;
60	u32 sent_acks;
61	u32 sent_bundled;
62	u32 sent_bundles;
63	u32 recv_bundled;
64	u32 recv_bundles;
65	u32 retransmitted;
66	u32 sent_fragmented;
67	u32 sent_fragments;
68	u32 recv_fragmented;
69	u32 recv_fragments;
70	u32 link_congs;		/* # port sends blocked by congestion */
71	u32 deferred_recv;
72	u32 duplicates;
73	u32 max_queue_sz;	/* send queue size high water mark */
74	u32 accu_queue_sz;	/* used for send queue size profiling */
75	u32 queue_sz_counts;	/* used for send queue size profiling */
76	u32 msg_length_counts;	/* used for message length profiling */
77	u32 msg_lengths_total;	/* used for message length profiling */
78	u32 msg_length_profile[7]; /* used for msg. length profiling */
79};
80
81/**
82 * struct tipc_link - TIPC link data structure
83 * @addr: network address of link's peer node
84 * @name: link name character string
85 * @media_addr: media address to use when sending messages over link
86 * @timer: link timer
87 * @net: pointer to namespace struct
88 * @refcnt: reference counter for permanent references (owner node & timer)
89 * @peer_session: link session # being used by peer end of link
90 * @peer_bearer_id: bearer id used by link's peer endpoint
91 * @bearer_id: local bearer id used by link
92 * @tolerance: minimum link continuity loss needed to reset link [in ms]
93 * @abort_limit: # of unacknowledged continuity probes needed to reset link
94 * @state: current state of link FSM
95 * @peer_caps: bitmap describing capabilities of peer node
96 * @silent_intv_cnt: # of timer intervals without any reception from peer
97 * @proto_msg: template for control messages generated by link
98 * @pmsg: convenience pointer to "proto_msg" field
99 * @priority: current link priority
100 * @net_plane: current link network plane ('A' through 'H')
101 * @mon_state: cookie with information needed by link monitor
102 * @backlog_limit: backlog queue congestion thresholds (indexed by importance)
103 * @exp_msg_count: # of tunnelled messages expected during link changeover
104 * @reset_rcv_checkpt: seq # of last acknowledged message at time of link reset
105 * @mtu: current maximum packet size for this link
106 * @advertised_mtu: advertised own mtu when link is being established
107 * @transmitq: queue for sent, non-acked messages
108 * @backlogq: queue for messages waiting to be sent
109 * @snt_nxt: next sequence number to use for outbound messages
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 * @session: session to be used by link
124 * @snd_nxt_state: next send seq number
125 * @rcv_nxt_state: next rcv seq number
126 * @in_session: have received ACTIVATE_MSG from peer
127 * @active: link is active
128 * @if_name: associated interface name
129 * @rst_cnt: link reset counter
130 * @drop_point: seq number for failover handling (FIXME)
131 * @failover_reasm_skb: saved failover msg ptr (FIXME)
132 * @failover_deferdq: deferred message queue for failover processing (FIXME)
133 * @transmq: the link's transmit queue
134 * @backlog: link's backlog by priority (importance)
135 * @snd_nxt: next sequence number to be used
136 * @rcv_unacked: # messages read by user, but not yet acked back to peer
137 * @deferdq: deferred receive queue
138 * @window: sliding window size for congestion handling
139 * @min_win: minimal send window to be used by link
140 * @ssthresh: slow start threshold for congestion handling
141 * @max_win: maximal send window to be used by link
142 * @cong_acks: congestion acks for congestion avoidance (FIXME)
143 * @checkpoint: seq number for congestion window size handling
144 * @reasm_tnlmsg: fragmentation/reassembly area for tunnel protocol message
145 * @last_gap: last gap ack blocks for bcast (FIXME)
146 * @last_ga: ptr to gap ack blocks
147 * @bc_rcvlink: the peer specific link used for broadcast reception
148 * @bc_sndlink: the namespace global link used for broadcast sending
149 * @nack_state: bcast nack state
150 * @bc_peer_is_up: peer has acked the bcast init msg
151 */
152struct tipc_link {
153	u32 addr;
154	char name[TIPC_MAX_LINK_NAME];
155	struct net *net;
156
157	/* Management and link supervision data */
158	u16 peer_session;
159	u16 session;
160	u16 snd_nxt_state;
161	u16 rcv_nxt_state;
162	u32 peer_bearer_id;
163	u32 bearer_id;
164	u32 tolerance;
165	u32 abort_limit;
166	u32 state;
167	u16 peer_caps;
168	bool in_session;
169	bool active;
170	u32 silent_intv_cnt;
171	char if_name[TIPC_MAX_IF_NAME];
172	u32 priority;
173	char net_plane;
174	struct tipc_mon_state mon_state;
175	u16 rst_cnt;
176
177	/* Failover/synch */
178	u16 drop_point;
179	struct sk_buff *failover_reasm_skb;
180	struct sk_buff_head failover_deferdq;
181
182	/* Max packet negotiation */
183	u16 mtu;
184	u16 advertised_mtu;
185
186	/* Sending */
187	struct sk_buff_head transmq;
188	struct sk_buff_head backlogq;
189	struct {
190		u16 len;
191		u16 limit;
192		struct sk_buff *target_bskb;
193	} backlog[5];
194	u16 snd_nxt;
195
196	/* Reception */
197	u16 rcv_nxt;
198	u32 rcv_unacked;
199	struct sk_buff_head deferdq;
200	struct sk_buff_head *inputq;
201	struct sk_buff_head *namedq;
202
203	/* Congestion handling */
204	struct sk_buff_head wakeupq;
205	u16 window;
206	u16 min_win;
207	u16 ssthresh;
208	u16 max_win;
209	u16 cong_acks;
210	u16 checkpoint;
211
212	/* Fragmentation/reassembly */
213	struct sk_buff *reasm_buf;
214	struct sk_buff *reasm_tnlmsg;
215
216	/* Broadcast */
217	u16 ackers;
218	u16 acked;
219	u16 last_gap;
220	struct tipc_gap_ack_blks *last_ga;
221	struct tipc_link *bc_rcvlink;
222	struct tipc_link *bc_sndlink;
223	u8 nack_state;
224	bool bc_peer_is_up;
225
226	/* Statistics */
227	struct tipc_stats stats;
228};
229
230/*
231 * Error message prefixes
232 */
233static const char *link_co_err = "Link tunneling error, ";
234static const char *link_rst_msg = "Resetting link ";
235
236/* Send states for broadcast NACKs
237 */
238enum {
239	BC_NACK_SND_CONDITIONAL,
240	BC_NACK_SND_UNCONDITIONAL,
241	BC_NACK_SND_SUPPRESS,
242};
243
244#define TIPC_BC_RETR_LIM  (jiffies + msecs_to_jiffies(10))
245#define TIPC_UC_RETR_TIME (jiffies + msecs_to_jiffies(1))
246
247/* Link FSM states:
248 */
249enum {
250	LINK_ESTABLISHED     = 0xe,
251	LINK_ESTABLISHING    = 0xe  << 4,
252	LINK_RESET           = 0x1  << 8,
253	LINK_RESETTING       = 0x2  << 12,
254	LINK_PEER_RESET      = 0xd  << 16,
255	LINK_FAILINGOVER     = 0xf  << 20,
256	LINK_SYNCHING        = 0xc  << 24
257};
258
259/* Link FSM state checking routines
260 */
261static int link_is_up(struct tipc_link *l)
262{
263	return l->state & (LINK_ESTABLISHED | LINK_SYNCHING);
264}
265
266static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
267			       struct sk_buff_head *xmitq);
268static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
269				      bool probe_reply, u16 rcvgap,
270				      int tolerance, int priority,
271				      struct sk_buff_head *xmitq);
272static void link_print(struct tipc_link *l, const char *str);
273static int tipc_link_build_nack_msg(struct tipc_link *l,
274				    struct sk_buff_head *xmitq);
275static void tipc_link_build_bc_init_msg(struct tipc_link *l,
276					struct sk_buff_head *xmitq);
277static u8 __tipc_build_gap_ack_blks(struct tipc_gap_ack_blks *ga,
278				    struct tipc_link *l, u8 start_index);
279static u16 tipc_build_gap_ack_blks(struct tipc_link *l, struct tipc_msg *hdr);
280static int tipc_link_advance_transmq(struct tipc_link *l, struct tipc_link *r,
281				     u16 acked, u16 gap,
282				     struct tipc_gap_ack_blks *ga,
283				     struct sk_buff_head *xmitq,
284				     bool *retransmitted, int *rc);
285static void tipc_link_update_cwin(struct tipc_link *l, int released,
286				  bool retransmitted);
287/*
288 *  Simple non-static link routines (i.e. referenced outside this file)
289 */
290bool tipc_link_is_up(struct tipc_link *l)
291{
292	return link_is_up(l);
293}
294
295bool tipc_link_peer_is_down(struct tipc_link *l)
296{
297	return l->state == LINK_PEER_RESET;
298}
299
300bool tipc_link_is_reset(struct tipc_link *l)
301{
302	return l->state & (LINK_RESET | LINK_FAILINGOVER | LINK_ESTABLISHING);
303}
304
305bool tipc_link_is_establishing(struct tipc_link *l)
306{
307	return l->state == LINK_ESTABLISHING;
308}
309
310bool tipc_link_is_synching(struct tipc_link *l)
311{
312	return l->state == LINK_SYNCHING;
313}
314
315bool tipc_link_is_failingover(struct tipc_link *l)
316{
317	return l->state == LINK_FAILINGOVER;
318}
319
320bool tipc_link_is_blocked(struct tipc_link *l)
321{
322	return l->state & (LINK_RESETTING | LINK_PEER_RESET | LINK_FAILINGOVER);
323}
324
325static bool link_is_bc_sndlink(struct tipc_link *l)
326{
327	return !l->bc_sndlink;
328}
329
330static bool link_is_bc_rcvlink(struct tipc_link *l)
331{
332	return ((l->bc_rcvlink == l) && !link_is_bc_sndlink(l));
333}
334
335void tipc_link_set_active(struct tipc_link *l, bool active)
336{
337	l->active = active;
338}
339
340u32 tipc_link_id(struct tipc_link *l)
341{
342	return l->peer_bearer_id << 16 | l->bearer_id;
343}
344
345int tipc_link_min_win(struct tipc_link *l)
346{
347	return l->min_win;
348}
349
350int tipc_link_max_win(struct tipc_link *l)
351{
352	return l->max_win;
353}
354
355int tipc_link_prio(struct tipc_link *l)
356{
357	return l->priority;
358}
359
360unsigned long tipc_link_tolerance(struct tipc_link *l)
361{
362	return l->tolerance;
363}
364
365struct sk_buff_head *tipc_link_inputq(struct tipc_link *l)
366{
367	return l->inputq;
368}
369
370char tipc_link_plane(struct tipc_link *l)
371{
372	return l->net_plane;
373}
374
375struct net *tipc_link_net(struct tipc_link *l)
376{
377	return l->net;
378}
379
380void tipc_link_update_caps(struct tipc_link *l, u16 capabilities)
381{
382	l->peer_caps = capabilities;
383}
384
385void tipc_link_add_bc_peer(struct tipc_link *snd_l,
386			   struct tipc_link *uc_l,
387			   struct sk_buff_head *xmitq)
388{
389	struct tipc_link *rcv_l = uc_l->bc_rcvlink;
390
391	snd_l->ackers++;
392	rcv_l->acked = snd_l->snd_nxt - 1;
393	snd_l->state = LINK_ESTABLISHED;
394	tipc_link_build_bc_init_msg(uc_l, xmitq);
395}
396
397void tipc_link_remove_bc_peer(struct tipc_link *snd_l,
398			      struct tipc_link *rcv_l,
399			      struct sk_buff_head *xmitq)
400{
401	u16 ack = snd_l->snd_nxt - 1;
402
403	snd_l->ackers--;
404	rcv_l->bc_peer_is_up = true;
405	rcv_l->state = LINK_ESTABLISHED;
406	tipc_link_bc_ack_rcv(rcv_l, ack, 0, NULL, xmitq, NULL);
407	trace_tipc_link_reset(rcv_l, TIPC_DUMP_ALL, "bclink removed!");
408	tipc_link_reset(rcv_l);
409	rcv_l->state = LINK_RESET;
410	if (!snd_l->ackers) {
411		trace_tipc_link_reset(snd_l, TIPC_DUMP_ALL, "zero ackers!");
412		tipc_link_reset(snd_l);
413		snd_l->state = LINK_RESET;
414		__skb_queue_purge(xmitq);
415	}
416}
417
418int tipc_link_bc_peers(struct tipc_link *l)
419{
420	return l->ackers;
421}
422
423static u16 link_bc_rcv_gap(struct tipc_link *l)
424{
425	struct sk_buff *skb = skb_peek(&l->deferdq);
426	u16 gap = 0;
427
428	if (more(l->snd_nxt, l->rcv_nxt))
429		gap = l->snd_nxt - l->rcv_nxt;
430	if (skb)
431		gap = buf_seqno(skb) - l->rcv_nxt;
432	return gap;
433}
434
435void tipc_link_set_mtu(struct tipc_link *l, int mtu)
436{
437	l->mtu = mtu;
438}
439
440int tipc_link_mtu(struct tipc_link *l)
441{
442	return l->mtu;
443}
444
445int tipc_link_mss(struct tipc_link *l)
446{
447#ifdef CONFIG_TIPC_CRYPTO
448	return l->mtu - INT_H_SIZE - EMSG_OVERHEAD;
449#else
450	return l->mtu - INT_H_SIZE;
451#endif
452}
453
454u16 tipc_link_rcv_nxt(struct tipc_link *l)
455{
456	return l->rcv_nxt;
457}
458
459u16 tipc_link_acked(struct tipc_link *l)
460{
461	return l->acked;
462}
463
464char *tipc_link_name(struct tipc_link *l)
465{
466	return l->name;
467}
468
469u32 tipc_link_state(struct tipc_link *l)
470{
471	return l->state;
472}
473
474/**
475 * tipc_link_create - create a new link
476 * @net: pointer to associated network namespace
477 * @if_name: associated interface name
478 * @bearer_id: id (index) of associated bearer
479 * @tolerance: link tolerance to be used by link
480 * @net_plane: network plane (A,B,c..) this link belongs to
481 * @mtu: mtu to be advertised by link
482 * @priority: priority to be used by link
483 * @min_win: minimal send window to be used by link
484 * @max_win: maximal send window to be used by link
485 * @session: session to be used by link
486 * @peer: node id of peer node
487 * @peer_caps: bitmap describing peer node capabilities
488 * @bc_sndlink: the namespace global link used for broadcast sending
489 * @bc_rcvlink: the peer specific link used for broadcast reception
490 * @inputq: queue to put messages ready for delivery
491 * @namedq: queue to put binding table update messages ready for delivery
492 * @link: return value, pointer to put the created link
493 * @self: local unicast link id
494 * @peer_id: 128-bit ID of peer
495 *
496 * Return: true if link was created, otherwise false
497 */
498bool tipc_link_create(struct net *net, char *if_name, int bearer_id,
499		      int tolerance, char net_plane, u32 mtu, int priority,
500		      u32 min_win, u32 max_win, u32 session, u32 self,
501		      u32 peer, u8 *peer_id, u16 peer_caps,
502		      struct tipc_link *bc_sndlink,
503		      struct tipc_link *bc_rcvlink,
504		      struct sk_buff_head *inputq,
505		      struct sk_buff_head *namedq,
506		      struct tipc_link **link)
507{
508	char peer_str[NODE_ID_STR_LEN] = {0,};
509	char self_str[NODE_ID_STR_LEN] = {0,};
510	struct tipc_link *l;
511
512	l = kzalloc(sizeof(*l), GFP_ATOMIC);
513	if (!l)
514		return false;
515	*link = l;
516	l->session = session;
517
518	/* Set link name for unicast links only */
519	if (peer_id) {
520		tipc_nodeid2string(self_str, tipc_own_id(net));
521		if (strlen(self_str) > 16)
522			sprintf(self_str, "%x", self);
523		tipc_nodeid2string(peer_str, peer_id);
524		if (strlen(peer_str) > 16)
525			sprintf(peer_str, "%x", peer);
526	}
527	/* Peer i/f name will be completed by reset/activate message */
528	snprintf(l->name, sizeof(l->name), "%s:%s-%s:unknown",
529		 self_str, if_name, peer_str);
530
531	strcpy(l->if_name, if_name);
532	l->addr = peer;
533	l->peer_caps = peer_caps;
534	l->net = net;
535	l->in_session = false;
536	l->bearer_id = bearer_id;
537	l->tolerance = tolerance;
538	if (bc_rcvlink)
539		bc_rcvlink->tolerance = tolerance;
540	l->net_plane = net_plane;
541	l->advertised_mtu = mtu;
542	l->mtu = mtu;
543	l->priority = priority;
544	tipc_link_set_queue_limits(l, min_win, max_win);
545	l->ackers = 1;
546	l->bc_sndlink = bc_sndlink;
547	l->bc_rcvlink = bc_rcvlink;
548	l->inputq = inputq;
549	l->namedq = namedq;
550	l->state = LINK_RESETTING;
551	__skb_queue_head_init(&l->transmq);
552	__skb_queue_head_init(&l->backlogq);
553	__skb_queue_head_init(&l->deferdq);
554	__skb_queue_head_init(&l->failover_deferdq);
555	skb_queue_head_init(&l->wakeupq);
556	skb_queue_head_init(l->inputq);
557	return true;
558}
559
560/**
561 * tipc_link_bc_create - create new link to be used for broadcast
562 * @net: pointer to associated network namespace
563 * @mtu: mtu to be used initially if no peers
564 * @min_win: minimal send window to be used by link
565 * @max_win: maximal send window to be used by link
566 * @inputq: queue to put messages ready for delivery
567 * @namedq: queue to put binding table update messages ready for delivery
568 * @link: return value, pointer to put the created link
569 * @ownnode: identity of own node
570 * @peer: node id of peer node
571 * @peer_id: 128-bit ID of peer
572 * @peer_caps: bitmap describing peer node capabilities
573 * @bc_sndlink: the namespace global link used for broadcast sending
574 *
575 * Return: true if link was created, otherwise false
576 */
577bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer, u8 *peer_id,
578			 int mtu, u32 min_win, u32 max_win, u16 peer_caps,
579			 struct sk_buff_head *inputq,
580			 struct sk_buff_head *namedq,
581			 struct tipc_link *bc_sndlink,
582			 struct tipc_link **link)
583{
584	struct tipc_link *l;
585
586	if (!tipc_link_create(net, "", MAX_BEARERS, 0, 'Z', mtu, 0, min_win,
587			      max_win, 0, ownnode, peer, NULL, peer_caps,
588			      bc_sndlink, NULL, inputq, namedq, link))
589		return false;
590
591	l = *link;
592	if (peer_id) {
593		char peer_str[NODE_ID_STR_LEN] = {0,};
594
595		tipc_nodeid2string(peer_str, peer_id);
596		if (strlen(peer_str) > 16)
597			sprintf(peer_str, "%x", peer);
598		/* Broadcast receiver link name: "broadcast-link:<peer>" */
599		snprintf(l->name, sizeof(l->name), "%s:%s", tipc_bclink_name,
600			 peer_str);
601	} else {
602		strcpy(l->name, tipc_bclink_name);
603	}
604	trace_tipc_link_reset(l, TIPC_DUMP_ALL, "bclink created!");
605	tipc_link_reset(l);
606	l->state = LINK_RESET;
607	l->ackers = 0;
608	l->bc_rcvlink = l;
609
610	/* Broadcast send link is always up */
611	if (link_is_bc_sndlink(l))
612		l->state = LINK_ESTABLISHED;
613
614	/* Disable replicast if even a single peer doesn't support it */
615	if (link_is_bc_rcvlink(l) && !(peer_caps & TIPC_BCAST_RCAST))
616		tipc_bcast_toggle_rcast(net, false);
617
618	return true;
619}
620
621/**
622 * tipc_link_fsm_evt - link finite state machine
623 * @l: pointer to link
624 * @evt: state machine event to be processed
625 */
626int tipc_link_fsm_evt(struct tipc_link *l, int evt)
627{
628	int rc = 0;
629	int old_state = l->state;
630
631	switch (l->state) {
632	case LINK_RESETTING:
633		switch (evt) {
634		case LINK_PEER_RESET_EVT:
635			l->state = LINK_PEER_RESET;
636			break;
637		case LINK_RESET_EVT:
638			l->state = LINK_RESET;
639			break;
640		case LINK_FAILURE_EVT:
641		case LINK_FAILOVER_BEGIN_EVT:
642		case LINK_ESTABLISH_EVT:
643		case LINK_FAILOVER_END_EVT:
644		case LINK_SYNCH_BEGIN_EVT:
645		case LINK_SYNCH_END_EVT:
646		default:
647			goto illegal_evt;
648		}
649		break;
650	case LINK_RESET:
651		switch (evt) {
652		case LINK_PEER_RESET_EVT:
653			l->state = LINK_ESTABLISHING;
654			break;
655		case LINK_FAILOVER_BEGIN_EVT:
656			l->state = LINK_FAILINGOVER;
657			break;
658		case LINK_FAILURE_EVT:
659		case LINK_RESET_EVT:
660		case LINK_ESTABLISH_EVT:
661		case LINK_FAILOVER_END_EVT:
662			break;
663		case LINK_SYNCH_BEGIN_EVT:
664		case LINK_SYNCH_END_EVT:
665		default:
666			goto illegal_evt;
667		}
668		break;
669	case LINK_PEER_RESET:
670		switch (evt) {
671		case LINK_RESET_EVT:
672			l->state = LINK_ESTABLISHING;
673			break;
674		case LINK_PEER_RESET_EVT:
675		case LINK_ESTABLISH_EVT:
676		case LINK_FAILURE_EVT:
677			break;
678		case LINK_SYNCH_BEGIN_EVT:
679		case LINK_SYNCH_END_EVT:
680		case LINK_FAILOVER_BEGIN_EVT:
681		case LINK_FAILOVER_END_EVT:
682		default:
683			goto illegal_evt;
684		}
685		break;
686	case LINK_FAILINGOVER:
687		switch (evt) {
688		case LINK_FAILOVER_END_EVT:
689			l->state = LINK_RESET;
690			break;
691		case LINK_PEER_RESET_EVT:
692		case LINK_RESET_EVT:
693		case LINK_ESTABLISH_EVT:
694		case LINK_FAILURE_EVT:
695			break;
696		case LINK_FAILOVER_BEGIN_EVT:
697		case LINK_SYNCH_BEGIN_EVT:
698		case LINK_SYNCH_END_EVT:
699		default:
700			goto illegal_evt;
701		}
702		break;
703	case LINK_ESTABLISHING:
704		switch (evt) {
705		case LINK_ESTABLISH_EVT:
706			l->state = LINK_ESTABLISHED;
707			break;
708		case LINK_FAILOVER_BEGIN_EVT:
709			l->state = LINK_FAILINGOVER;
710			break;
711		case LINK_RESET_EVT:
712			l->state = LINK_RESET;
713			break;
714		case LINK_FAILURE_EVT:
715		case LINK_PEER_RESET_EVT:
716		case LINK_SYNCH_BEGIN_EVT:
717		case LINK_FAILOVER_END_EVT:
718			break;
719		case LINK_SYNCH_END_EVT:
720		default:
721			goto illegal_evt;
722		}
723		break;
724	case LINK_ESTABLISHED:
725		switch (evt) {
726		case LINK_PEER_RESET_EVT:
727			l->state = LINK_PEER_RESET;
728			rc |= TIPC_LINK_DOWN_EVT;
729			break;
730		case LINK_FAILURE_EVT:
731			l->state = LINK_RESETTING;
732			rc |= TIPC_LINK_DOWN_EVT;
733			break;
734		case LINK_RESET_EVT:
735			l->state = LINK_RESET;
736			break;
737		case LINK_ESTABLISH_EVT:
738		case LINK_SYNCH_END_EVT:
739			break;
740		case LINK_SYNCH_BEGIN_EVT:
741			l->state = LINK_SYNCHING;
742			break;
743		case LINK_FAILOVER_BEGIN_EVT:
744		case LINK_FAILOVER_END_EVT:
745		default:
746			goto illegal_evt;
747		}
748		break;
749	case LINK_SYNCHING:
750		switch (evt) {
751		case LINK_PEER_RESET_EVT:
752			l->state = LINK_PEER_RESET;
753			rc |= TIPC_LINK_DOWN_EVT;
754			break;
755		case LINK_FAILURE_EVT:
756			l->state = LINK_RESETTING;
757			rc |= TIPC_LINK_DOWN_EVT;
758			break;
759		case LINK_RESET_EVT:
760			l->state = LINK_RESET;
761			break;
762		case LINK_ESTABLISH_EVT:
763		case LINK_SYNCH_BEGIN_EVT:
764			break;
765		case LINK_SYNCH_END_EVT:
766			l->state = LINK_ESTABLISHED;
767			break;
768		case LINK_FAILOVER_BEGIN_EVT:
769		case LINK_FAILOVER_END_EVT:
770		default:
771			goto illegal_evt;
772		}
773		break;
774	default:
775		pr_err("Unknown FSM state %x in %s\n", l->state, l->name);
776	}
777	trace_tipc_link_fsm(l->name, old_state, l->state, evt);
778	return rc;
779illegal_evt:
780	pr_err("Illegal FSM event %x in state %x on link %s\n",
781	       evt, l->state, l->name);
782	trace_tipc_link_fsm(l->name, old_state, l->state, evt);
783	return rc;
784}
785
786/* link_profile_stats - update statistical profiling of traffic
787 */
788static void link_profile_stats(struct tipc_link *l)
789{
790	struct sk_buff *skb;
791	struct tipc_msg *msg;
792	int length;
793
794	/* Update counters used in statistical profiling of send traffic */
795	l->stats.accu_queue_sz += skb_queue_len(&l->transmq);
796	l->stats.queue_sz_counts++;
797
798	skb = skb_peek(&l->transmq);
799	if (!skb)
800		return;
801	msg = buf_msg(skb);
802	length = msg_size(msg);
803
804	if (msg_user(msg) == MSG_FRAGMENTER) {
805		if (msg_type(msg) != FIRST_FRAGMENT)
806			return;
807		length = msg_size(msg_inner_hdr(msg));
808	}
809	l->stats.msg_lengths_total += length;
810	l->stats.msg_length_counts++;
811	if (length <= 64)
812		l->stats.msg_length_profile[0]++;
813	else if (length <= 256)
814		l->stats.msg_length_profile[1]++;
815	else if (length <= 1024)
816		l->stats.msg_length_profile[2]++;
817	else if (length <= 4096)
818		l->stats.msg_length_profile[3]++;
819	else if (length <= 16384)
820		l->stats.msg_length_profile[4]++;
821	else if (length <= 32768)
822		l->stats.msg_length_profile[5]++;
823	else
824		l->stats.msg_length_profile[6]++;
825}
826
827/**
828 * tipc_link_too_silent - check if link is "too silent"
829 * @l: tipc link to be checked
830 *
831 * Return: true if the link 'silent_intv_cnt' is about to reach the
832 * 'abort_limit' value, otherwise false
833 */
834bool tipc_link_too_silent(struct tipc_link *l)
835{
836	return (l->silent_intv_cnt + 2 > l->abort_limit);
837}
838
839/* tipc_link_timeout - perform periodic task as instructed from node timeout
840 */
841int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
842{
843	int mtyp = 0;
844	int rc = 0;
845	bool state = false;
846	bool probe = false;
847	bool setup = false;
848	u16 bc_snt = l->bc_sndlink->snd_nxt - 1;
849	u16 bc_acked = l->bc_rcvlink->acked;
850	struct tipc_mon_state *mstate = &l->mon_state;
851
852	trace_tipc_link_timeout(l, TIPC_DUMP_NONE, " ");
853	trace_tipc_link_too_silent(l, TIPC_DUMP_ALL, " ");
854	switch (l->state) {
855	case LINK_ESTABLISHED:
856	case LINK_SYNCHING:
857		mtyp = STATE_MSG;
858		link_profile_stats(l);
859		tipc_mon_get_state(l->net, l->addr, mstate, l->bearer_id);
860		if (mstate->reset || (l->silent_intv_cnt > l->abort_limit))
861			return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
862		state = bc_acked != bc_snt;
863		state |= l->bc_rcvlink->rcv_unacked;
864		state |= l->rcv_unacked;
865		state |= !skb_queue_empty(&l->transmq);
866		probe = mstate->probing;
867		probe |= l->silent_intv_cnt;
868		if (probe || mstate->monitoring)
869			l->silent_intv_cnt++;
870		probe |= !skb_queue_empty(&l->deferdq);
871		if (l->snd_nxt == l->checkpoint) {
872			tipc_link_update_cwin(l, 0, 0);
873			probe = true;
874		}
875		l->checkpoint = l->snd_nxt;
876		break;
877	case LINK_RESET:
878		setup = l->rst_cnt++ <= 4;
879		setup |= !(l->rst_cnt % 16);
880		mtyp = RESET_MSG;
881		break;
882	case LINK_ESTABLISHING:
883		setup = true;
884		mtyp = ACTIVATE_MSG;
885		break;
886	case LINK_PEER_RESET:
887	case LINK_RESETTING:
888	case LINK_FAILINGOVER:
889		break;
890	default:
891		break;
892	}
893
894	if (state || probe || setup)
895		tipc_link_build_proto_msg(l, mtyp, probe, 0, 0, 0, 0, xmitq);
896
897	return rc;
898}
899
900/**
901 * link_schedule_user - schedule a message sender for wakeup after congestion
902 * @l: congested link
903 * @hdr: header of message that is being sent
904 * Create pseudo msg to send back to user when congestion abates
905 */
906static int link_schedule_user(struct tipc_link *l, struct tipc_msg *hdr)
907{
908	u32 dnode = tipc_own_addr(l->net);
909	u32 dport = msg_origport(hdr);
910	struct sk_buff *skb;
911
912	/* Create and schedule wakeup pseudo message */
913	skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
914			      dnode, l->addr, dport, 0, 0);
915	if (!skb)
916		return -ENOBUFS;
917	msg_set_dest_droppable(buf_msg(skb), true);
918	TIPC_SKB_CB(skb)->chain_imp = msg_importance(hdr);
919	skb_queue_tail(&l->wakeupq, skb);
920	l->stats.link_congs++;
921	trace_tipc_link_conges(l, TIPC_DUMP_ALL, "wakeup scheduled!");
922	return -ELINKCONG;
923}
924
925/**
926 * link_prepare_wakeup - prepare users for wakeup after congestion
927 * @l: congested link
928 * Wake up a number of waiting users, as permitted by available space
929 * in the send queue
930 */
931static void link_prepare_wakeup(struct tipc_link *l)
932{
933	struct sk_buff_head *wakeupq = &l->wakeupq;
934	struct sk_buff_head *inputq = l->inputq;
935	struct sk_buff *skb, *tmp;
936	struct sk_buff_head tmpq;
937	int avail[5] = {0,};
938	int imp = 0;
939
940	__skb_queue_head_init(&tmpq);
941
942	for (; imp <= TIPC_SYSTEM_IMPORTANCE; imp++)
943		avail[imp] = l->backlog[imp].limit - l->backlog[imp].len;
944
945	skb_queue_walk_safe(wakeupq, skb, tmp) {
946		imp = TIPC_SKB_CB(skb)->chain_imp;
947		if (avail[imp] <= 0)
948			continue;
949		avail[imp]--;
950		__skb_unlink(skb, wakeupq);
951		__skb_queue_tail(&tmpq, skb);
952	}
953
954	spin_lock_bh(&inputq->lock);
955	skb_queue_splice_tail(&tmpq, inputq);
956	spin_unlock_bh(&inputq->lock);
957
958}
959
960/**
961 * tipc_link_set_skb_retransmit_time - set the time at which retransmission of
962 *                                     the given skb should be next attempted
963 * @skb: skb to set a future retransmission time for
964 * @l: link the skb will be transmitted on
965 */
966static void tipc_link_set_skb_retransmit_time(struct sk_buff *skb,
967					      struct tipc_link *l)
968{
969	if (link_is_bc_sndlink(l))
970		TIPC_SKB_CB(skb)->nxt_retr = TIPC_BC_RETR_LIM;
971	else
972		TIPC_SKB_CB(skb)->nxt_retr = TIPC_UC_RETR_TIME;
973}
974
975void tipc_link_reset(struct tipc_link *l)
976{
977	struct sk_buff_head list;
978	u32 imp;
979
980	__skb_queue_head_init(&list);
981
982	l->in_session = false;
983	/* Force re-synch of peer session number before establishing */
984	l->peer_session--;
985	l->session++;
986	l->mtu = l->advertised_mtu;
987
988	spin_lock_bh(&l->wakeupq.lock);
989	skb_queue_splice_init(&l->wakeupq, &list);
990	spin_unlock_bh(&l->wakeupq.lock);
991
992	spin_lock_bh(&l->inputq->lock);
993	skb_queue_splice_init(&list, l->inputq);
994	spin_unlock_bh(&l->inputq->lock);
995
996	__skb_queue_purge(&l->transmq);
997	__skb_queue_purge(&l->deferdq);
998	__skb_queue_purge(&l->backlogq);
999	__skb_queue_purge(&l->failover_deferdq);
1000	for (imp = 0; imp <= TIPC_SYSTEM_IMPORTANCE; imp++) {
1001		l->backlog[imp].len = 0;
1002		l->backlog[imp].target_bskb = NULL;
1003	}
1004	kfree_skb(l->reasm_buf);
1005	kfree_skb(l->reasm_tnlmsg);
1006	kfree_skb(l->failover_reasm_skb);
1007	l->reasm_buf = NULL;
1008	l->reasm_tnlmsg = NULL;
1009	l->failover_reasm_skb = NULL;
1010	l->rcv_unacked = 0;
1011	l->snd_nxt = 1;
1012	l->rcv_nxt = 1;
1013	l->snd_nxt_state = 1;
1014	l->rcv_nxt_state = 1;
1015	l->acked = 0;
1016	l->last_gap = 0;
1017	kfree(l->last_ga);
1018	l->last_ga = NULL;
1019	l->silent_intv_cnt = 0;
1020	l->rst_cnt = 0;
1021	l->bc_peer_is_up = false;
1022	memset(&l->mon_state, 0, sizeof(l->mon_state));
1023	tipc_link_reset_stats(l);
1024}
1025
1026/**
1027 * tipc_link_xmit(): enqueue buffer list according to queue situation
1028 * @l: link to use
1029 * @list: chain of buffers containing message
1030 * @xmitq: returned list of packets to be sent by caller
1031 *
1032 * Consumes the buffer chain.
1033 * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
1034 * Return: 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
1035 */
1036int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
1037		   struct sk_buff_head *xmitq)
1038{
1039	struct sk_buff_head *backlogq = &l->backlogq;
1040	struct sk_buff_head *transmq = &l->transmq;
1041	struct sk_buff *skb, *_skb;
1042	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
1043	u16 ack = l->rcv_nxt - 1;
1044	u16 seqno = l->snd_nxt;
1045	int pkt_cnt = skb_queue_len(list);
1046	unsigned int mss = tipc_link_mss(l);
1047	unsigned int cwin = l->window;
1048	unsigned int mtu = l->mtu;
1049	struct tipc_msg *hdr;
1050	bool new_bundle;
1051	int rc = 0;
1052	int imp;
1053
1054	if (pkt_cnt <= 0)
1055		return 0;
1056
1057	hdr = buf_msg(skb_peek(list));
1058	if (unlikely(msg_size(hdr) > mtu)) {
1059		pr_warn("Too large msg, purging xmit list %d %d %d %d %d!\n",
1060			skb_queue_len(list), msg_user(hdr),
1061			msg_type(hdr), msg_size(hdr), mtu);
1062		__skb_queue_purge(list);
1063		return -EMSGSIZE;
1064	}
1065
1066	imp = msg_importance(hdr);
1067	/* Allow oversubscription of one data msg per source at congestion */
1068	if (unlikely(l->backlog[imp].len >= l->backlog[imp].limit)) {
1069		if (imp == TIPC_SYSTEM_IMPORTANCE) {
1070			pr_warn("%s<%s>, link overflow", link_rst_msg, l->name);
1071			return -ENOBUFS;
1072		}
1073		rc = link_schedule_user(l, hdr);
1074	}
1075
1076	if (pkt_cnt > 1) {
1077		l->stats.sent_fragmented++;
1078		l->stats.sent_fragments += pkt_cnt;
1079	}
1080
1081	/* Prepare each packet for sending, and add to relevant queue: */
1082	while ((skb = __skb_dequeue(list))) {
1083		if (likely(skb_queue_len(transmq) < cwin)) {
1084			hdr = buf_msg(skb);
1085			msg_set_seqno(hdr, seqno);
1086			msg_set_ack(hdr, ack);
1087			msg_set_bcast_ack(hdr, bc_ack);
1088			_skb = skb_clone(skb, GFP_ATOMIC);
1089			if (!_skb) {
1090				kfree_skb(skb);
1091				__skb_queue_purge(list);
1092				return -ENOBUFS;
1093			}
1094			__skb_queue_tail(transmq, skb);
1095			tipc_link_set_skb_retransmit_time(skb, l);
1096			__skb_queue_tail(xmitq, _skb);
1097			TIPC_SKB_CB(skb)->ackers = l->ackers;
1098			l->rcv_unacked = 0;
1099			l->stats.sent_pkts++;
1100			seqno++;
1101			continue;
1102		}
1103		if (tipc_msg_try_bundle(l->backlog[imp].target_bskb, &skb,
1104					mss, l->addr, &new_bundle)) {
1105			if (skb) {
1106				/* Keep a ref. to the skb for next try */
1107				l->backlog[imp].target_bskb = skb;
1108				l->backlog[imp].len++;
1109				__skb_queue_tail(backlogq, skb);
1110			} else {
1111				if (new_bundle) {
1112					l->stats.sent_bundles++;
1113					l->stats.sent_bundled++;
1114				}
1115				l->stats.sent_bundled++;
1116			}
1117			continue;
1118		}
1119		l->backlog[imp].target_bskb = NULL;
1120		l->backlog[imp].len += (1 + skb_queue_len(list));
1121		__skb_queue_tail(backlogq, skb);
1122		skb_queue_splice_tail_init(list, backlogq);
1123	}
1124	l->snd_nxt = seqno;
1125	return rc;
1126}
1127
1128static void tipc_link_update_cwin(struct tipc_link *l, int released,
1129				  bool retransmitted)
1130{
1131	int bklog_len = skb_queue_len(&l->backlogq);
1132	struct sk_buff_head *txq = &l->transmq;
1133	int txq_len = skb_queue_len(txq);
1134	u16 cwin = l->window;
1135
1136	/* Enter fast recovery */
1137	if (unlikely(retransmitted)) {
1138		l->ssthresh = max_t(u16, l->window / 2, 300);
1139		l->window = min_t(u16, l->ssthresh, l->window);
1140		return;
1141	}
1142	/* Enter slow start */
1143	if (unlikely(!released)) {
1144		l->ssthresh = max_t(u16, l->window / 2, 300);
1145		l->window = l->min_win;
1146		return;
1147	}
1148	/* Don't increase window if no pressure on the transmit queue */
1149	if (txq_len + bklog_len < cwin)
1150		return;
1151
1152	/* Don't increase window if there are holes the transmit queue */
1153	if (txq_len && l->snd_nxt - buf_seqno(skb_peek(txq)) != txq_len)
1154		return;
1155
1156	l->cong_acks += released;
1157
1158	/* Slow start  */
1159	if (cwin <= l->ssthresh) {
1160		l->window = min_t(u16, cwin + released, l->max_win);
1161		return;
1162	}
1163	/* Congestion avoidance */
1164	if (l->cong_acks < cwin)
1165		return;
1166	l->window = min_t(u16, ++cwin, l->max_win);
1167	l->cong_acks = 0;
1168}
1169
1170static void tipc_link_advance_backlog(struct tipc_link *l,
1171				      struct sk_buff_head *xmitq)
1172{
1173	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
1174	struct sk_buff_head *txq = &l->transmq;
1175	struct sk_buff *skb, *_skb;
1176	u16 ack = l->rcv_nxt - 1;
1177	u16 seqno = l->snd_nxt;
1178	struct tipc_msg *hdr;
1179	u16 cwin = l->window;
1180	u32 imp;
1181
1182	while (skb_queue_len(txq) < cwin) {
1183		skb = skb_peek(&l->backlogq);
1184		if (!skb)
1185			break;
1186		_skb = skb_clone(skb, GFP_ATOMIC);
1187		if (!_skb)
1188			break;
1189		__skb_dequeue(&l->backlogq);
1190		hdr = buf_msg(skb);
1191		imp = msg_importance(hdr);
1192		l->backlog[imp].len--;
1193		if (unlikely(skb == l->backlog[imp].target_bskb))
1194			l->backlog[imp].target_bskb = NULL;
1195		__skb_queue_tail(&l->transmq, skb);
1196		tipc_link_set_skb_retransmit_time(skb, l);
1197
1198		__skb_queue_tail(xmitq, _skb);
1199		TIPC_SKB_CB(skb)->ackers = l->ackers;
1200		msg_set_seqno(hdr, seqno);
1201		msg_set_ack(hdr, ack);
1202		msg_set_bcast_ack(hdr, bc_ack);
1203		l->rcv_unacked = 0;
1204		l->stats.sent_pkts++;
1205		seqno++;
1206	}
1207	l->snd_nxt = seqno;
1208}
1209
1210/**
1211 * link_retransmit_failure() - Detect repeated retransmit failures
1212 * @l: tipc link sender
1213 * @r: tipc link receiver (= l in case of unicast)
1214 * @rc: returned code
1215 *
1216 * Return: true if the repeated retransmit failures happens, otherwise
1217 * false
1218 */
1219static bool link_retransmit_failure(struct tipc_link *l, struct tipc_link *r,
1220				    int *rc)
1221{
1222	struct sk_buff *skb = skb_peek(&l->transmq);
1223	struct tipc_msg *hdr;
1224
1225	if (!skb)
1226		return false;
1227
1228	if (!TIPC_SKB_CB(skb)->retr_cnt)
1229		return false;
1230
1231	if (!time_after(jiffies, TIPC_SKB_CB(skb)->retr_stamp +
1232			msecs_to_jiffies(r->tolerance * 10)))
1233		return false;
1234
1235	hdr = buf_msg(skb);
1236	if (link_is_bc_sndlink(l) && !less(r->acked, msg_seqno(hdr)))
1237		return false;
1238
1239	pr_warn("Retransmission failure on link <%s>\n", l->name);
1240	link_print(l, "State of link ");
1241	pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
1242		msg_user(hdr), msg_type(hdr), msg_size(hdr), msg_errcode(hdr));
1243	pr_info("sqno %u, prev: %x, dest: %x\n",
1244		msg_seqno(hdr), msg_prevnode(hdr), msg_destnode(hdr));
1245	pr_info("retr_stamp %d, retr_cnt %d\n",
1246		jiffies_to_msecs(TIPC_SKB_CB(skb)->retr_stamp),
1247		TIPC_SKB_CB(skb)->retr_cnt);
1248
1249	trace_tipc_list_dump(&l->transmq, true, "retrans failure!");
1250	trace_tipc_link_dump(l, TIPC_DUMP_NONE, "retrans failure!");
1251	trace_tipc_link_dump(r, TIPC_DUMP_NONE, "retrans failure!");
1252
1253	if (link_is_bc_sndlink(l)) {
1254		r->state = LINK_RESET;
1255		*rc |= TIPC_LINK_DOWN_EVT;
1256	} else {
1257		*rc |= tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1258	}
1259
1260	return true;
1261}
1262
1263/* tipc_data_input - deliver data and name distr msgs to upper layer
1264 *
1265 * Consumes buffer if message is of right type
1266 * Node lock must be held
1267 */
1268static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb,
1269			    struct sk_buff_head *inputq)
1270{
1271	struct sk_buff_head *mc_inputq = l->bc_rcvlink->inputq;
1272	struct tipc_msg *hdr = buf_msg(skb);
1273
1274	switch (msg_user(hdr)) {
1275	case TIPC_LOW_IMPORTANCE:
1276	case TIPC_MEDIUM_IMPORTANCE:
1277	case TIPC_HIGH_IMPORTANCE:
1278	case TIPC_CRITICAL_IMPORTANCE:
1279		if (unlikely(msg_in_group(hdr) || msg_mcast(hdr))) {
1280			skb_queue_tail(mc_inputq, skb);
1281			return true;
1282		}
1283		fallthrough;
1284	case CONN_MANAGER:
1285		skb_queue_tail(inputq, skb);
1286		return true;
1287	case GROUP_PROTOCOL:
1288		skb_queue_tail(mc_inputq, skb);
1289		return true;
1290	case NAME_DISTRIBUTOR:
1291		l->bc_rcvlink->state = LINK_ESTABLISHED;
1292		skb_queue_tail(l->namedq, skb);
1293		return true;
1294	case MSG_BUNDLER:
1295	case TUNNEL_PROTOCOL:
1296	case MSG_FRAGMENTER:
1297	case BCAST_PROTOCOL:
1298		return false;
1299#ifdef CONFIG_TIPC_CRYPTO
1300	case MSG_CRYPTO:
1301		if (sysctl_tipc_key_exchange_enabled &&
1302		    TIPC_SKB_CB(skb)->decrypted) {
1303			tipc_crypto_msg_rcv(l->net, skb);
1304			return true;
1305		}
1306		fallthrough;
1307#endif
1308	default:
1309		pr_warn("Dropping received illegal msg type\n");
1310		kfree_skb(skb);
1311		return true;
1312	}
1313}
1314
1315/* tipc_link_input - process packet that has passed link protocol check
1316 *
1317 * Consumes buffer
1318 */
1319static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb,
1320			   struct sk_buff_head *inputq,
1321			   struct sk_buff **reasm_skb)
1322{
1323	struct tipc_msg *hdr = buf_msg(skb);
1324	struct sk_buff *iskb;
1325	struct sk_buff_head tmpq;
1326	int usr = msg_user(hdr);
1327	int pos = 0;
1328
1329	if (usr == MSG_BUNDLER) {
1330		skb_queue_head_init(&tmpq);
1331		l->stats.recv_bundles++;
1332		l->stats.recv_bundled += msg_msgcnt(hdr);
1333		while (tipc_msg_extract(skb, &iskb, &pos))
1334			tipc_data_input(l, iskb, &tmpq);
1335		tipc_skb_queue_splice_tail(&tmpq, inputq);
1336		return 0;
1337	} else if (usr == MSG_FRAGMENTER) {
1338		l->stats.recv_fragments++;
1339		if (tipc_buf_append(reasm_skb, &skb)) {
1340			l->stats.recv_fragmented++;
1341			tipc_data_input(l, skb, inputq);
1342		} else if (!*reasm_skb && !link_is_bc_rcvlink(l)) {
1343			pr_warn_ratelimited("Unable to build fragment list\n");
1344			return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1345		}
1346		return 0;
1347	} else if (usr == BCAST_PROTOCOL) {
1348		tipc_bcast_lock(l->net);
1349		tipc_link_bc_init_rcv(l->bc_rcvlink, hdr);
1350		tipc_bcast_unlock(l->net);
1351	}
1352
1353	kfree_skb(skb);
1354	return 0;
1355}
1356
1357/* tipc_link_tnl_rcv() - receive TUNNEL_PROTOCOL message, drop or process the
1358 *			 inner message along with the ones in the old link's
1359 *			 deferdq
1360 * @l: tunnel link
1361 * @skb: TUNNEL_PROTOCOL message
1362 * @inputq: queue to put messages ready for delivery
1363 */
1364static int tipc_link_tnl_rcv(struct tipc_link *l, struct sk_buff *skb,
1365			     struct sk_buff_head *inputq)
1366{
1367	struct sk_buff **reasm_skb = &l->failover_reasm_skb;
1368	struct sk_buff **reasm_tnlmsg = &l->reasm_tnlmsg;
1369	struct sk_buff_head *fdefq = &l->failover_deferdq;
1370	struct tipc_msg *hdr = buf_msg(skb);
1371	struct sk_buff *iskb;
1372	int ipos = 0;
1373	int rc = 0;
1374	u16 seqno;
1375
1376	if (msg_type(hdr) == SYNCH_MSG) {
1377		kfree_skb(skb);
1378		return 0;
1379	}
1380
1381	/* Not a fragment? */
1382	if (likely(!msg_nof_fragms(hdr))) {
1383		if (unlikely(!tipc_msg_extract(skb, &iskb, &ipos))) {
1384			pr_warn_ratelimited("Unable to extract msg, defq: %d\n",
1385					    skb_queue_len(fdefq));
1386			return 0;
1387		}
1388		kfree_skb(skb);
1389	} else {
1390		/* Set fragment type for buf_append */
1391		if (msg_fragm_no(hdr) == 1)
1392			msg_set_type(hdr, FIRST_FRAGMENT);
1393		else if (msg_fragm_no(hdr) < msg_nof_fragms(hdr))
1394			msg_set_type(hdr, FRAGMENT);
1395		else
1396			msg_set_type(hdr, LAST_FRAGMENT);
1397
1398		if (!tipc_buf_append(reasm_tnlmsg, &skb)) {
1399			/* Successful but non-complete reassembly? */
1400			if (*reasm_tnlmsg || link_is_bc_rcvlink(l))
1401				return 0;
1402			pr_warn_ratelimited("Unable to reassemble tunnel msg\n");
1403			return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1404		}
1405		iskb = skb;
1406	}
1407
1408	do {
1409		seqno = buf_seqno(iskb);
1410		if (unlikely(less(seqno, l->drop_point))) {
1411			kfree_skb(iskb);
1412			continue;
1413		}
1414		if (unlikely(seqno != l->drop_point)) {
1415			__tipc_skb_queue_sorted(fdefq, seqno, iskb);
1416			continue;
1417		}
1418
1419		l->drop_point++;
1420		if (!tipc_data_input(l, iskb, inputq))
1421			rc |= tipc_link_input(l, iskb, inputq, reasm_skb);
1422		if (unlikely(rc))
1423			break;
1424	} while ((iskb = __tipc_skb_dequeue(fdefq, l->drop_point)));
1425
1426	return rc;
1427}
1428
1429/**
1430 * tipc_get_gap_ack_blks - get Gap ACK blocks from PROTOCOL/STATE_MSG
1431 * @ga: returned pointer to the Gap ACK blocks if any
1432 * @l: the tipc link
1433 * @hdr: the PROTOCOL/STATE_MSG header
1434 * @uc: desired Gap ACK blocks type, i.e. unicast (= 1) or broadcast (= 0)
1435 *
1436 * Return: the total Gap ACK blocks size
1437 */
1438u16 tipc_get_gap_ack_blks(struct tipc_gap_ack_blks **ga, struct tipc_link *l,
1439			  struct tipc_msg *hdr, bool uc)
1440{
1441	struct tipc_gap_ack_blks *p;
1442	u16 sz = 0;
1443
1444	/* Does peer support the Gap ACK blocks feature? */
1445	if (l->peer_caps & TIPC_GAP_ACK_BLOCK) {
1446		p = (struct tipc_gap_ack_blks *)msg_data(hdr);
1447		sz = ntohs(p->len);
1448		/* Sanity check */
1449		if (sz == struct_size(p, gacks, size_add(p->ugack_cnt, p->bgack_cnt))) {
1450			/* Good, check if the desired type exists */
1451			if ((uc && p->ugack_cnt) || (!uc && p->bgack_cnt))
1452				goto ok;
1453		/* Backward compatible: peer might not support bc, but uc? */
1454		} else if (uc && sz == struct_size(p, gacks, p->ugack_cnt)) {
1455			if (p->ugack_cnt) {
1456				p->bgack_cnt = 0;
1457				goto ok;
1458			}
1459		}
1460	}
1461	/* Other cases: ignore! */
1462	p = NULL;
1463
1464ok:
1465	*ga = p;
1466	return sz;
1467}
1468
1469static u8 __tipc_build_gap_ack_blks(struct tipc_gap_ack_blks *ga,
1470				    struct tipc_link *l, u8 start_index)
1471{
1472	struct tipc_gap_ack *gacks = &ga->gacks[start_index];
1473	struct sk_buff *skb = skb_peek(&l->deferdq);
1474	u16 expect, seqno = 0;
1475	u8 n = 0;
1476
1477	if (!skb)
1478		return 0;
1479
1480	expect = buf_seqno(skb);
1481	skb_queue_walk(&l->deferdq, skb) {
1482		seqno = buf_seqno(skb);
1483		if (unlikely(more(seqno, expect))) {
1484			gacks[n].ack = htons(expect - 1);
1485			gacks[n].gap = htons(seqno - expect);
1486			if (++n >= MAX_GAP_ACK_BLKS / 2) {
1487				pr_info_ratelimited("Gacks on %s: %d, ql: %d!\n",
1488						    l->name, n,
1489						    skb_queue_len(&l->deferdq));
1490				return n;
1491			}
1492		} else if (unlikely(less(seqno, expect))) {
1493			pr_warn("Unexpected skb in deferdq!\n");
1494			continue;
1495		}
1496		expect = seqno + 1;
1497	}
1498
1499	/* last block */
1500	gacks[n].ack = htons(seqno);
1501	gacks[n].gap = 0;
1502	n++;
1503	return n;
1504}
1505
1506/* tipc_build_gap_ack_blks - build Gap ACK blocks
1507 * @l: tipc unicast link
1508 * @hdr: the tipc message buffer to store the Gap ACK blocks after built
1509 *
1510 * The function builds Gap ACK blocks for both the unicast & broadcast receiver
1511 * links of a certain peer, the buffer after built has the network data format
1512 * as found at the struct tipc_gap_ack_blks definition.
1513 *
1514 * returns the actual allocated memory size
1515 */
1516static u16 tipc_build_gap_ack_blks(struct tipc_link *l, struct tipc_msg *hdr)
1517{
1518	struct tipc_link *bcl = l->bc_rcvlink;
1519	struct tipc_gap_ack_blks *ga;
1520	u16 len;
1521
1522	ga = (struct tipc_gap_ack_blks *)msg_data(hdr);
1523
1524	/* Start with broadcast link first */
1525	tipc_bcast_lock(bcl->net);
1526	msg_set_bcast_ack(hdr, bcl->rcv_nxt - 1);
1527	msg_set_bc_gap(hdr, link_bc_rcv_gap(bcl));
1528	ga->bgack_cnt = __tipc_build_gap_ack_blks(ga, bcl, 0);
1529	tipc_bcast_unlock(bcl->net);
1530
1531	/* Now for unicast link, but an explicit NACK only (???) */
1532	ga->ugack_cnt = (msg_seq_gap(hdr)) ?
1533			__tipc_build_gap_ack_blks(ga, l, ga->bgack_cnt) : 0;
1534
1535	/* Total len */
1536	len = struct_size(ga, gacks, size_add(ga->bgack_cnt, ga->ugack_cnt));
1537	ga->len = htons(len);
1538	return len;
1539}
1540
1541/* tipc_link_advance_transmq - advance TIPC link transmq queue by releasing
1542 *			       acked packets, also doing retransmissions if
1543 *			       gaps found
1544 * @l: tipc link with transmq queue to be advanced
1545 * @r: tipc link "receiver" i.e. in case of broadcast (= "l" if unicast)
1546 * @acked: seqno of last packet acked by peer without any gaps before
1547 * @gap: # of gap packets
1548 * @ga: buffer pointer to Gap ACK blocks from peer
1549 * @xmitq: queue for accumulating the retransmitted packets if any
1550 * @retransmitted: returned boolean value if a retransmission is really issued
1551 * @rc: returned code e.g. TIPC_LINK_DOWN_EVT if a repeated retransmit failures
1552 *      happens (- unlikely case)
1553 *
1554 * Return: the number of packets released from the link transmq
1555 */
1556static int tipc_link_advance_transmq(struct tipc_link *l, struct tipc_link *r,
1557				     u16 acked, u16 gap,
1558				     struct tipc_gap_ack_blks *ga,
1559				     struct sk_buff_head *xmitq,
1560				     bool *retransmitted, int *rc)
1561{
1562	struct tipc_gap_ack_blks *last_ga = r->last_ga, *this_ga = NULL;
1563	struct tipc_gap_ack *gacks = NULL;
1564	struct sk_buff *skb, *_skb, *tmp;
1565	struct tipc_msg *hdr;
1566	u32 qlen = skb_queue_len(&l->transmq);
1567	u16 nacked = acked, ngap = gap, gack_cnt = 0;
1568	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
1569	u16 ack = l->rcv_nxt - 1;
1570	u16 seqno, n = 0;
1571	u16 end = r->acked, start = end, offset = r->last_gap;
1572	u16 si = (last_ga) ? last_ga->start_index : 0;
1573	bool is_uc = !link_is_bc_sndlink(l);
1574	bool bc_has_acked = false;
1575
1576	trace_tipc_link_retrans(r, acked + 1, acked + gap, &l->transmq);
1577
1578	/* Determine Gap ACK blocks if any for the particular link */
1579	if (ga && is_uc) {
1580		/* Get the Gap ACKs, uc part */
1581		gack_cnt = ga->ugack_cnt;
1582		gacks = &ga->gacks[ga->bgack_cnt];
1583	} else if (ga) {
1584		/* Copy the Gap ACKs, bc part, for later renewal if needed */
1585		this_ga = kmemdup(ga, struct_size(ga, gacks, ga->bgack_cnt),
1586				  GFP_ATOMIC);
1587		if (likely(this_ga)) {
1588			this_ga->start_index = 0;
1589			/* Start with the bc Gap ACKs */
1590			gack_cnt = this_ga->bgack_cnt;
1591			gacks = &this_ga->gacks[0];
1592		} else {
1593			/* Hmm, we can get in trouble..., simply ignore it */
1594			pr_warn_ratelimited("Ignoring bc Gap ACKs, no memory\n");
1595		}
1596	}
1597
1598	/* Advance the link transmq */
1599	skb_queue_walk_safe(&l->transmq, skb, tmp) {
1600		seqno = buf_seqno(skb);
1601
1602next_gap_ack:
1603		if (less_eq(seqno, nacked)) {
1604			if (is_uc)
1605				goto release;
1606			/* Skip packets peer has already acked */
1607			if (!more(seqno, r->acked))
1608				continue;
1609			/* Get the next of last Gap ACK blocks */
1610			while (more(seqno, end)) {
1611				if (!last_ga || si >= last_ga->bgack_cnt)
1612					break;
1613				start = end + offset + 1;
1614				end = ntohs(last_ga->gacks[si].ack);
1615				offset = ntohs(last_ga->gacks[si].gap);
1616				si++;
1617				WARN_ONCE(more(start, end) ||
1618					  (!offset &&
1619					   si < last_ga->bgack_cnt) ||
1620					  si > MAX_GAP_ACK_BLKS,
1621					  "Corrupted Gap ACK: %d %d %d %d %d\n",
1622					  start, end, offset, si,
1623					  last_ga->bgack_cnt);
1624			}
1625			/* Check against the last Gap ACK block */
1626			if (tipc_in_range(seqno, start, end))
1627				continue;
1628			/* Update/release the packet peer is acking */
1629			bc_has_acked = true;
1630			if (--TIPC_SKB_CB(skb)->ackers)
1631				continue;
1632release:
1633			/* release skb */
1634			__skb_unlink(skb, &l->transmq);
1635			kfree_skb(skb);
1636		} else if (less_eq(seqno, nacked + ngap)) {
1637			/* First gap: check if repeated retrans failures? */
1638			if (unlikely(seqno == acked + 1 &&
1639				     link_retransmit_failure(l, r, rc))) {
1640				/* Ignore this bc Gap ACKs if any */
1641				kfree(this_ga);
1642				this_ga = NULL;
1643				break;
1644			}
1645			/* retransmit skb if unrestricted*/
1646			if (time_before(jiffies, TIPC_SKB_CB(skb)->nxt_retr))
1647				continue;
1648			tipc_link_set_skb_retransmit_time(skb, l);
1649			_skb = pskb_copy(skb, GFP_ATOMIC);
1650			if (!_skb)
1651				continue;
1652			hdr = buf_msg(_skb);
1653			msg_set_ack(hdr, ack);
1654			msg_set_bcast_ack(hdr, bc_ack);
1655			_skb->priority = TC_PRIO_CONTROL;
1656			__skb_queue_tail(xmitq, _skb);
1657			l->stats.retransmitted++;
1658			if (!is_uc)
1659				r->stats.retransmitted++;
1660			*retransmitted = true;
1661			/* Increase actual retrans counter & mark first time */
1662			if (!TIPC_SKB_CB(skb)->retr_cnt++)
1663				TIPC_SKB_CB(skb)->retr_stamp = jiffies;
1664		} else {
1665			/* retry with Gap ACK blocks if any */
1666			if (n >= gack_cnt)
1667				break;
1668			nacked = ntohs(gacks[n].ack);
1669			ngap = ntohs(gacks[n].gap);
1670			n++;
1671			goto next_gap_ack;
1672		}
1673	}
1674
1675	/* Renew last Gap ACK blocks for bc if needed */
1676	if (bc_has_acked) {
1677		if (this_ga) {
1678			kfree(last_ga);
1679			r->last_ga = this_ga;
1680			r->last_gap = gap;
1681		} else if (last_ga) {
1682			if (less(acked, start)) {
1683				si--;
1684				offset = start - acked - 1;
1685			} else if (less(acked, end)) {
1686				acked = end;
1687			}
1688			if (si < last_ga->bgack_cnt) {
1689				last_ga->start_index = si;
1690				r->last_gap = offset;
1691			} else {
1692				kfree(last_ga);
1693				r->last_ga = NULL;
1694				r->last_gap = 0;
1695			}
1696		} else {
1697			r->last_gap = 0;
1698		}
1699		r->acked = acked;
1700	} else {
1701		kfree(this_ga);
1702	}
1703
1704	return qlen - skb_queue_len(&l->transmq);
1705}
1706
1707/* tipc_link_build_state_msg: prepare link state message for transmission
1708 *
1709 * Note that sending of broadcast ack is coordinated among nodes, to reduce
1710 * risk of ack storms towards the sender
1711 */
1712int tipc_link_build_state_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1713{
1714	if (!l)
1715		return 0;
1716
1717	/* Broadcast ACK must be sent via a unicast link => defer to caller */
1718	if (link_is_bc_rcvlink(l)) {
1719		if (((l->rcv_nxt ^ tipc_own_addr(l->net)) & 0xf) != 0xf)
1720			return 0;
1721		l->rcv_unacked = 0;
1722
1723		/* Use snd_nxt to store peer's snd_nxt in broadcast rcv link */
1724		l->snd_nxt = l->rcv_nxt;
1725		return TIPC_LINK_SND_STATE;
1726	}
1727	/* Unicast ACK */
1728	l->rcv_unacked = 0;
1729	l->stats.sent_acks++;
1730	tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, 0, xmitq);
1731	return 0;
1732}
1733
1734/* tipc_link_build_reset_msg: prepare link RESET or ACTIVATE message
1735 */
1736void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1737{
1738	int mtyp = RESET_MSG;
1739	struct sk_buff *skb;
1740
1741	if (l->state == LINK_ESTABLISHING)
1742		mtyp = ACTIVATE_MSG;
1743
1744	tipc_link_build_proto_msg(l, mtyp, 0, 0, 0, 0, 0, xmitq);
1745
1746	/* Inform peer that this endpoint is going down if applicable */
1747	skb = skb_peek_tail(xmitq);
1748	if (skb && (l->state == LINK_RESET))
1749		msg_set_peer_stopping(buf_msg(skb), 1);
1750}
1751
1752/* tipc_link_build_nack_msg: prepare link nack message for transmission
1753 * Note that sending of broadcast NACK is coordinated among nodes, to
1754 * reduce the risk of NACK storms towards the sender
1755 */
1756static int tipc_link_build_nack_msg(struct tipc_link *l,
1757				    struct sk_buff_head *xmitq)
1758{
1759	u32 def_cnt = ++l->stats.deferred_recv;
1760	struct sk_buff_head *dfq = &l->deferdq;
1761	u32 defq_len = skb_queue_len(dfq);
1762	int match1, match2;
1763
1764	if (link_is_bc_rcvlink(l)) {
1765		match1 = def_cnt & 0xf;
1766		match2 = tipc_own_addr(l->net) & 0xf;
1767		if (match1 == match2)
1768			return TIPC_LINK_SND_STATE;
1769		return 0;
1770	}
1771
1772	if (defq_len >= 3 && !((defq_len - 3) % 16)) {
1773		u16 rcvgap = buf_seqno(skb_peek(dfq)) - l->rcv_nxt;
1774
1775		tipc_link_build_proto_msg(l, STATE_MSG, 0, 0,
1776					  rcvgap, 0, 0, xmitq);
1777	}
1778	return 0;
1779}
1780
1781/* tipc_link_rcv - process TIPC packets/messages arriving from off-node
1782 * @l: the link that should handle the message
1783 * @skb: TIPC packet
1784 * @xmitq: queue to place packets to be sent after this call
1785 */
1786int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
1787		  struct sk_buff_head *xmitq)
1788{
1789	struct sk_buff_head *defq = &l->deferdq;
1790	struct tipc_msg *hdr = buf_msg(skb);
1791	u16 seqno, rcv_nxt, win_lim;
1792	int released = 0;
1793	int rc = 0;
1794
1795	/* Verify and update link state */
1796	if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
1797		return tipc_link_proto_rcv(l, skb, xmitq);
1798
1799	/* Don't send probe at next timeout expiration */
1800	l->silent_intv_cnt = 0;
1801
1802	do {
1803		hdr = buf_msg(skb);
1804		seqno = msg_seqno(hdr);
1805		rcv_nxt = l->rcv_nxt;
1806		win_lim = rcv_nxt + TIPC_MAX_LINK_WIN;
1807
1808		if (unlikely(!link_is_up(l))) {
1809			if (l->state == LINK_ESTABLISHING)
1810				rc = TIPC_LINK_UP_EVT;
1811			kfree_skb(skb);
1812			break;
1813		}
1814
1815		/* Drop if outside receive window */
1816		if (unlikely(less(seqno, rcv_nxt) || more(seqno, win_lim))) {
1817			l->stats.duplicates++;
1818			kfree_skb(skb);
1819			break;
1820		}
1821		released += tipc_link_advance_transmq(l, l, msg_ack(hdr), 0,
1822						      NULL, NULL, NULL, NULL);
1823
1824		/* Defer delivery if sequence gap */
1825		if (unlikely(seqno != rcv_nxt)) {
1826			if (!__tipc_skb_queue_sorted(defq, seqno, skb))
1827				l->stats.duplicates++;
1828			rc |= tipc_link_build_nack_msg(l, xmitq);
1829			break;
1830		}
1831
1832		/* Deliver packet */
1833		l->rcv_nxt++;
1834		l->stats.recv_pkts++;
1835
1836		if (unlikely(msg_user(hdr) == TUNNEL_PROTOCOL))
1837			rc |= tipc_link_tnl_rcv(l, skb, l->inputq);
1838		else if (!tipc_data_input(l, skb, l->inputq))
1839			rc |= tipc_link_input(l, skb, l->inputq, &l->reasm_buf);
1840		if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
1841			rc |= tipc_link_build_state_msg(l, xmitq);
1842		if (unlikely(rc & ~TIPC_LINK_SND_STATE))
1843			break;
1844	} while ((skb = __tipc_skb_dequeue(defq, l->rcv_nxt)));
1845
1846	/* Forward queues and wake up waiting users */
1847	if (released) {
1848		tipc_link_update_cwin(l, released, 0);
1849		tipc_link_advance_backlog(l, xmitq);
1850		if (unlikely(!skb_queue_empty(&l->wakeupq)))
1851			link_prepare_wakeup(l);
1852	}
1853	return rc;
1854}
1855
1856static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
1857				      bool probe_reply, u16 rcvgap,
1858				      int tolerance, int priority,
1859				      struct sk_buff_head *xmitq)
1860{
1861	struct tipc_mon_state *mstate = &l->mon_state;
1862	struct sk_buff_head *dfq = &l->deferdq;
1863	struct tipc_link *bcl = l->bc_rcvlink;
1864	struct tipc_msg *hdr;
1865	struct sk_buff *skb;
1866	bool node_up = link_is_up(bcl);
1867	u16 glen = 0, bc_rcvgap = 0;
1868	int dlen = 0;
1869	void *data;
1870
1871	/* Don't send protocol message during reset or link failover */
1872	if (tipc_link_is_blocked(l))
1873		return;
1874
1875	if (!tipc_link_is_up(l) && (mtyp == STATE_MSG))
1876		return;
1877
1878	if ((probe || probe_reply) && !skb_queue_empty(dfq))
1879		rcvgap = buf_seqno(skb_peek(dfq)) - l->rcv_nxt;
1880
1881	skb = tipc_msg_create(LINK_PROTOCOL, mtyp, INT_H_SIZE,
1882			      tipc_max_domain_size + MAX_GAP_ACK_BLKS_SZ,
1883			      l->addr, tipc_own_addr(l->net), 0, 0, 0);
1884	if (!skb)
1885		return;
1886
1887	hdr = buf_msg(skb);
1888	data = msg_data(hdr);
1889	msg_set_session(hdr, l->session);
1890	msg_set_bearer_id(hdr, l->bearer_id);
1891	msg_set_net_plane(hdr, l->net_plane);
1892	msg_set_next_sent(hdr, l->snd_nxt);
1893	msg_set_ack(hdr, l->rcv_nxt - 1);
1894	msg_set_bcast_ack(hdr, bcl->rcv_nxt - 1);
1895	msg_set_bc_ack_invalid(hdr, !node_up);
1896	msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
1897	msg_set_link_tolerance(hdr, tolerance);
1898	msg_set_linkprio(hdr, priority);
1899	msg_set_redundant_link(hdr, node_up);
1900	msg_set_seq_gap(hdr, 0);
1901	msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2);
1902
1903	if (mtyp == STATE_MSG) {
1904		if (l->peer_caps & TIPC_LINK_PROTO_SEQNO)
1905			msg_set_seqno(hdr, l->snd_nxt_state++);
1906		msg_set_seq_gap(hdr, rcvgap);
1907		bc_rcvgap = link_bc_rcv_gap(bcl);
1908		msg_set_bc_gap(hdr, bc_rcvgap);
1909		msg_set_probe(hdr, probe);
1910		msg_set_is_keepalive(hdr, probe || probe_reply);
1911		if (l->peer_caps & TIPC_GAP_ACK_BLOCK)
1912			glen = tipc_build_gap_ack_blks(l, hdr);
1913		tipc_mon_prep(l->net, data + glen, &dlen, mstate, l->bearer_id);
1914		msg_set_size(hdr, INT_H_SIZE + glen + dlen);
1915		skb_trim(skb, INT_H_SIZE + glen + dlen);
1916		l->stats.sent_states++;
1917		l->rcv_unacked = 0;
1918	} else {
1919		/* RESET_MSG or ACTIVATE_MSG */
1920		if (mtyp == ACTIVATE_MSG) {
1921			msg_set_dest_session_valid(hdr, 1);
1922			msg_set_dest_session(hdr, l->peer_session);
1923		}
1924		msg_set_max_pkt(hdr, l->advertised_mtu);
1925		strcpy(data, l->if_name);
1926		msg_set_size(hdr, INT_H_SIZE + TIPC_MAX_IF_NAME);
1927		skb_trim(skb, INT_H_SIZE + TIPC_MAX_IF_NAME);
1928	}
1929	if (probe)
1930		l->stats.sent_probes++;
1931	if (rcvgap)
1932		l->stats.sent_nacks++;
1933	if (bc_rcvgap)
1934		bcl->stats.sent_nacks++;
1935	skb->priority = TC_PRIO_CONTROL;
1936	__skb_queue_tail(xmitq, skb);
1937	trace_tipc_proto_build(skb, false, l->name);
1938}
1939
1940void tipc_link_create_dummy_tnl_msg(struct tipc_link *l,
1941				    struct sk_buff_head *xmitq)
1942{
1943	u32 onode = tipc_own_addr(l->net);
1944	struct tipc_msg *hdr, *ihdr;
1945	struct sk_buff_head tnlq;
1946	struct sk_buff *skb;
1947	u32 dnode = l->addr;
1948
1949	__skb_queue_head_init(&tnlq);
1950	skb = tipc_msg_create(TUNNEL_PROTOCOL, FAILOVER_MSG,
1951			      INT_H_SIZE, BASIC_H_SIZE,
1952			      dnode, onode, 0, 0, 0);
1953	if (!skb) {
1954		pr_warn("%sunable to create tunnel packet\n", link_co_err);
1955		return;
1956	}
1957
1958	hdr = buf_msg(skb);
1959	msg_set_msgcnt(hdr, 1);
1960	msg_set_bearer_id(hdr, l->peer_bearer_id);
1961
1962	ihdr = (struct tipc_msg *)msg_data(hdr);
1963	tipc_msg_init(onode, ihdr, TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
1964		      BASIC_H_SIZE, dnode);
1965	msg_set_errcode(ihdr, TIPC_ERR_NO_PORT);
1966	__skb_queue_tail(&tnlq, skb);
1967	tipc_link_xmit(l, &tnlq, xmitq);
1968}
1969
1970/* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets
1971 * with contents of the link's transmit and backlog queues.
1972 */
1973void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
1974			   int mtyp, struct sk_buff_head *xmitq)
1975{
1976	struct sk_buff_head *fdefq = &tnl->failover_deferdq;
1977	struct sk_buff *skb, *tnlskb;
1978	struct tipc_msg *hdr, tnlhdr;
1979	struct sk_buff_head *queue = &l->transmq;
1980	struct sk_buff_head tmpxq, tnlq, frags;
1981	u16 pktlen, pktcnt, seqno = l->snd_nxt;
1982	bool pktcnt_need_update = false;
1983	u16 syncpt;
1984	int rc;
1985
1986	if (!tnl)
1987		return;
1988
1989	__skb_queue_head_init(&tnlq);
1990	/* Link Synching:
1991	 * From now on, send only one single ("dummy") SYNCH message
1992	 * to peer. The SYNCH message does not contain any data, just
1993	 * a header conveying the synch point to the peer.
1994	 */
1995	if (mtyp == SYNCH_MSG && (tnl->peer_caps & TIPC_TUNNEL_ENHANCED)) {
1996		tnlskb = tipc_msg_create(TUNNEL_PROTOCOL, SYNCH_MSG,
1997					 INT_H_SIZE, 0, l->addr,
1998					 tipc_own_addr(l->net),
1999					 0, 0, 0);
2000		if (!tnlskb) {
2001			pr_warn("%sunable to create dummy SYNCH_MSG\n",
2002				link_co_err);
2003			return;
2004		}
2005
2006		hdr = buf_msg(tnlskb);
2007		syncpt = l->snd_nxt + skb_queue_len(&l->backlogq) - 1;
2008		msg_set_syncpt(hdr, syncpt);
2009		msg_set_bearer_id(hdr, l->peer_bearer_id);
2010		__skb_queue_tail(&tnlq, tnlskb);
2011		tipc_link_xmit(tnl, &tnlq, xmitq);
2012		return;
2013	}
2014
2015	__skb_queue_head_init(&tmpxq);
2016	__skb_queue_head_init(&frags);
2017	/* At least one packet required for safe algorithm => add dummy */
2018	skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
2019			      BASIC_H_SIZE, 0, l->addr, tipc_own_addr(l->net),
2020			      0, 0, TIPC_ERR_NO_PORT);
2021	if (!skb) {
2022		pr_warn("%sunable to create tunnel packet\n", link_co_err);
2023		return;
2024	}
2025	__skb_queue_tail(&tnlq, skb);
2026	tipc_link_xmit(l, &tnlq, &tmpxq);
2027	__skb_queue_purge(&tmpxq);
2028
2029	/* Initialize reusable tunnel packet header */
2030	tipc_msg_init(tipc_own_addr(l->net), &tnlhdr, TUNNEL_PROTOCOL,
2031		      mtyp, INT_H_SIZE, l->addr);
2032	if (mtyp == SYNCH_MSG)
2033		pktcnt = l->snd_nxt - buf_seqno(skb_peek(&l->transmq));
2034	else
2035		pktcnt = skb_queue_len(&l->transmq);
2036	pktcnt += skb_queue_len(&l->backlogq);
2037	msg_set_msgcnt(&tnlhdr, pktcnt);
2038	msg_set_bearer_id(&tnlhdr, l->peer_bearer_id);
2039tnl:
2040	/* Wrap each packet into a tunnel packet */
2041	skb_queue_walk(queue, skb) {
2042		hdr = buf_msg(skb);
2043		if (queue == &l->backlogq)
2044			msg_set_seqno(hdr, seqno++);
2045		pktlen = msg_size(hdr);
2046
2047		/* Tunnel link MTU is not large enough? This could be
2048		 * due to:
2049		 * 1) Link MTU has just changed or set differently;
2050		 * 2) Or FAILOVER on the top of a SYNCH message
2051		 *
2052		 * The 2nd case should not happen if peer supports
2053		 * TIPC_TUNNEL_ENHANCED
2054		 */
2055		if (pktlen > tnl->mtu - INT_H_SIZE) {
2056			if (mtyp == FAILOVER_MSG &&
2057			    (tnl->peer_caps & TIPC_TUNNEL_ENHANCED)) {
2058				rc = tipc_msg_fragment(skb, &tnlhdr, tnl->mtu,
2059						       &frags);
2060				if (rc) {
2061					pr_warn("%sunable to frag msg: rc %d\n",
2062						link_co_err, rc);
2063					return;
2064				}
2065				pktcnt += skb_queue_len(&frags) - 1;
2066				pktcnt_need_update = true;
2067				skb_queue_splice_tail_init(&frags, &tnlq);
2068				continue;
2069			}
2070			/* Unluckily, peer doesn't have TIPC_TUNNEL_ENHANCED
2071			 * => Just warn it and return!
2072			 */
2073			pr_warn_ratelimited("%stoo large msg <%d, %d>: %d!\n",
2074					    link_co_err, msg_user(hdr),
2075					    msg_type(hdr), msg_size(hdr));
2076			return;
2077		}
2078
2079		msg_set_size(&tnlhdr, pktlen + INT_H_SIZE);
2080		tnlskb = tipc_buf_acquire(pktlen + INT_H_SIZE, GFP_ATOMIC);
2081		if (!tnlskb) {
2082			pr_warn("%sunable to send packet\n", link_co_err);
2083			return;
2084		}
2085		skb_copy_to_linear_data(tnlskb, &tnlhdr, INT_H_SIZE);
2086		skb_copy_to_linear_data_offset(tnlskb, INT_H_SIZE, hdr, pktlen);
2087		__skb_queue_tail(&tnlq, tnlskb);
2088	}
2089	if (queue != &l->backlogq) {
2090		queue = &l->backlogq;
2091		goto tnl;
2092	}
2093
2094	if (pktcnt_need_update)
2095		skb_queue_walk(&tnlq, skb) {
2096			hdr = buf_msg(skb);
2097			msg_set_msgcnt(hdr, pktcnt);
2098		}
2099
2100	tipc_link_xmit(tnl, &tnlq, xmitq);
2101
2102	if (mtyp == FAILOVER_MSG) {
2103		tnl->drop_point = l->rcv_nxt;
2104		tnl->failover_reasm_skb = l->reasm_buf;
2105		l->reasm_buf = NULL;
2106
2107		/* Failover the link's deferdq */
2108		if (unlikely(!skb_queue_empty(fdefq))) {
2109			pr_warn("Link failover deferdq not empty: %d!\n",
2110				skb_queue_len(fdefq));
2111			__skb_queue_purge(fdefq);
2112		}
2113		skb_queue_splice_init(&l->deferdq, fdefq);
2114	}
2115}
2116
2117/**
2118 * tipc_link_failover_prepare() - prepare tnl for link failover
2119 *
2120 * This is a special version of the precursor - tipc_link_tnl_prepare(),
2121 * see the tipc_node_link_failover() for details
2122 *
2123 * @l: failover link
2124 * @tnl: tunnel link
2125 * @xmitq: queue for messages to be xmited
2126 */
2127void tipc_link_failover_prepare(struct tipc_link *l, struct tipc_link *tnl,
2128				struct sk_buff_head *xmitq)
2129{
2130	struct sk_buff_head *fdefq = &tnl->failover_deferdq;
2131
2132	tipc_link_create_dummy_tnl_msg(tnl, xmitq);
2133
2134	/* This failover link endpoint was never established before,
2135	 * so it has not received anything from peer.
2136	 * Otherwise, it must be a normal failover situation or the
2137	 * node has entered SELF_DOWN_PEER_LEAVING and both peer nodes
2138	 * would have to start over from scratch instead.
2139	 */
2140	tnl->drop_point = 1;
2141	tnl->failover_reasm_skb = NULL;
2142
2143	/* Initiate the link's failover deferdq */
2144	if (unlikely(!skb_queue_empty(fdefq))) {
2145		pr_warn("Link failover deferdq not empty: %d!\n",
2146			skb_queue_len(fdefq));
2147		__skb_queue_purge(fdefq);
2148	}
2149}
2150
2151/* tipc_link_validate_msg(): validate message against current link state
2152 * Returns true if message should be accepted, otherwise false
2153 */
2154bool tipc_link_validate_msg(struct tipc_link *l, struct tipc_msg *hdr)
2155{
2156	u16 curr_session = l->peer_session;
2157	u16 session = msg_session(hdr);
2158	int mtyp = msg_type(hdr);
2159
2160	if (msg_user(hdr) != LINK_PROTOCOL)
2161		return true;
2162
2163	switch (mtyp) {
2164	case RESET_MSG:
2165		if (!l->in_session)
2166			return true;
2167		/* Accept only RESET with new session number */
2168		return more(session, curr_session);
2169	case ACTIVATE_MSG:
2170		if (!l->in_session)
2171			return true;
2172		/* Accept only ACTIVATE with new or current session number */
2173		return !less(session, curr_session);
2174	case STATE_MSG:
2175		/* Accept only STATE with current session number */
2176		if (!l->in_session)
2177			return false;
2178		if (session != curr_session)
2179			return false;
2180		/* Extra sanity check */
2181		if (!link_is_up(l) && msg_ack(hdr))
2182			return false;
2183		if (!(l->peer_caps & TIPC_LINK_PROTO_SEQNO))
2184			return true;
2185		/* Accept only STATE with new sequence number */
2186		return !less(msg_seqno(hdr), l->rcv_nxt_state);
2187	default:
2188		return false;
2189	}
2190}
2191
2192/* tipc_link_proto_rcv(): receive link level protocol message :
2193 * Note that network plane id propagates through the network, and may
2194 * change at any time. The node with lowest numerical id determines
2195 * network plane
2196 */
2197static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
2198			       struct sk_buff_head *xmitq)
2199{
2200	struct tipc_msg *hdr = buf_msg(skb);
2201	struct tipc_gap_ack_blks *ga = NULL;
2202	bool reply = msg_probe(hdr), retransmitted = false;
2203	u32 dlen = msg_data_sz(hdr), glen = 0, msg_max;
2204	u16 peers_snd_nxt =  msg_next_sent(hdr);
2205	u16 peers_tol = msg_link_tolerance(hdr);
2206	u16 peers_prio = msg_linkprio(hdr);
2207	u16 gap = msg_seq_gap(hdr);
2208	u16 ack = msg_ack(hdr);
2209	u16 rcv_nxt = l->rcv_nxt;
2210	u16 rcvgap = 0;
2211	int mtyp = msg_type(hdr);
2212	int rc = 0, released;
2213	char *if_name;
2214	void *data;
2215
2216	trace_tipc_proto_rcv(skb, false, l->name);
2217
2218	if (dlen > U16_MAX)
2219		goto exit;
2220
2221	if (tipc_link_is_blocked(l) || !xmitq)
2222		goto exit;
2223
2224	if (tipc_own_addr(l->net) > msg_prevnode(hdr))
2225		l->net_plane = msg_net_plane(hdr);
2226
2227	if (skb_linearize(skb))
2228		goto exit;
2229
2230	hdr = buf_msg(skb);
2231	data = msg_data(hdr);
2232
2233	if (!tipc_link_validate_msg(l, hdr)) {
2234		trace_tipc_skb_dump(skb, false, "PROTO invalid (1)!");
2235		trace_tipc_link_dump(l, TIPC_DUMP_NONE, "PROTO invalid (1)!");
2236		goto exit;
2237	}
2238
2239	switch (mtyp) {
2240	case RESET_MSG:
2241	case ACTIVATE_MSG:
2242		msg_max = msg_max_pkt(hdr);
2243		if (msg_max < tipc_bearer_min_mtu(l->net, l->bearer_id))
2244			break;
2245		/* Complete own link name with peer's interface name */
2246		if_name =  strrchr(l->name, ':') + 1;
2247		if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME)
2248			break;
2249		if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME)
2250			break;
2251		strncpy(if_name, data, TIPC_MAX_IF_NAME);
2252
2253		/* Update own tolerance if peer indicates a non-zero value */
2254		if (tipc_in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL)) {
2255			l->tolerance = peers_tol;
2256			l->bc_rcvlink->tolerance = peers_tol;
2257		}
2258		/* Update own priority if peer's priority is higher */
2259		if (tipc_in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
2260			l->priority = peers_prio;
2261
2262		/* If peer is going down we want full re-establish cycle */
2263		if (msg_peer_stopping(hdr)) {
2264			rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
2265			break;
2266		}
2267
2268		/* If this endpoint was re-created while peer was ESTABLISHING
2269		 * it doesn't know current session number. Force re-synch.
2270		 */
2271		if (mtyp == ACTIVATE_MSG && msg_dest_session_valid(hdr) &&
2272		    l->session != msg_dest_session(hdr)) {
2273			if (less(l->session, msg_dest_session(hdr)))
2274				l->session = msg_dest_session(hdr) + 1;
2275			break;
2276		}
2277
2278		/* ACTIVATE_MSG serves as PEER_RESET if link is already down */
2279		if (mtyp == RESET_MSG || !link_is_up(l))
2280			rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
2281
2282		/* ACTIVATE_MSG takes up link if it was already locally reset */
2283		if (mtyp == ACTIVATE_MSG && l->state == LINK_ESTABLISHING)
2284			rc = TIPC_LINK_UP_EVT;
2285
2286		l->peer_session = msg_session(hdr);
2287		l->in_session = true;
2288		l->peer_bearer_id = msg_bearer_id(hdr);
2289		if (l->mtu > msg_max)
2290			l->mtu = msg_max;
2291		break;
2292
2293	case STATE_MSG:
2294		/* Validate Gap ACK blocks, drop if invalid */
2295		glen = tipc_get_gap_ack_blks(&ga, l, hdr, true);
2296		if (glen > dlen)
2297			break;
2298
2299		l->rcv_nxt_state = msg_seqno(hdr) + 1;
2300
2301		/* Update own tolerance if peer indicates a non-zero value */
2302		if (tipc_in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL)) {
2303			l->tolerance = peers_tol;
2304			l->bc_rcvlink->tolerance = peers_tol;
2305		}
2306		/* Update own prio if peer indicates a different value */
2307		if ((peers_prio != l->priority) &&
2308		    tipc_in_range(peers_prio, 1, TIPC_MAX_LINK_PRI)) {
2309			l->priority = peers_prio;
2310			rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
2311		}
2312
2313		l->silent_intv_cnt = 0;
2314		l->stats.recv_states++;
2315		if (msg_probe(hdr))
2316			l->stats.recv_probes++;
2317
2318		if (!link_is_up(l)) {
2319			if (l->state == LINK_ESTABLISHING)
2320				rc = TIPC_LINK_UP_EVT;
2321			break;
2322		}
2323
2324		tipc_mon_rcv(l->net, data + glen, dlen - glen, l->addr,
2325			     &l->mon_state, l->bearer_id);
2326
2327		/* Send NACK if peer has sent pkts we haven't received yet */
2328		if ((reply || msg_is_keepalive(hdr)) &&
2329		    more(peers_snd_nxt, rcv_nxt) &&
2330		    !tipc_link_is_synching(l) &&
2331		    skb_queue_empty(&l->deferdq))
2332			rcvgap = peers_snd_nxt - l->rcv_nxt;
2333		if (rcvgap || reply)
2334			tipc_link_build_proto_msg(l, STATE_MSG, 0, reply,
2335						  rcvgap, 0, 0, xmitq);
2336
2337		released = tipc_link_advance_transmq(l, l, ack, gap, ga, xmitq,
2338						     &retransmitted, &rc);
2339		if (gap)
2340			l->stats.recv_nacks++;
2341		if (released || retransmitted)
2342			tipc_link_update_cwin(l, released, retransmitted);
2343		if (released)
2344			tipc_link_advance_backlog(l, xmitq);
2345		if (unlikely(!skb_queue_empty(&l->wakeupq)))
2346			link_prepare_wakeup(l);
2347	}
2348exit:
2349	kfree_skb(skb);
2350	return rc;
2351}
2352
2353/* tipc_link_build_bc_proto_msg() - create broadcast protocol message
2354 */
2355static bool tipc_link_build_bc_proto_msg(struct tipc_link *l, bool bcast,
2356					 u16 peers_snd_nxt,
2357					 struct sk_buff_head *xmitq)
2358{
2359	struct sk_buff *skb;
2360	struct tipc_msg *hdr;
2361	struct sk_buff *dfrd_skb = skb_peek(&l->deferdq);
2362	u16 ack = l->rcv_nxt - 1;
2363	u16 gap_to = peers_snd_nxt - 1;
2364
2365	skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
2366			      0, l->addr, tipc_own_addr(l->net), 0, 0, 0);
2367	if (!skb)
2368		return false;
2369	hdr = buf_msg(skb);
2370	msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
2371	msg_set_bcast_ack(hdr, ack);
2372	msg_set_bcgap_after(hdr, ack);
2373	if (dfrd_skb)
2374		gap_to = buf_seqno(dfrd_skb) - 1;
2375	msg_set_bcgap_to(hdr, gap_to);
2376	msg_set_non_seq(hdr, bcast);
2377	__skb_queue_tail(xmitq, skb);
2378	return true;
2379}
2380
2381/* tipc_link_build_bc_init_msg() - synchronize broadcast link endpoints.
2382 *
2383 * Give a newly added peer node the sequence number where it should
2384 * start receiving and acking broadcast packets.
2385 */
2386static void tipc_link_build_bc_init_msg(struct tipc_link *l,
2387					struct sk_buff_head *xmitq)
2388{
2389	struct sk_buff_head list;
2390
2391	__skb_queue_head_init(&list);
2392	if (!tipc_link_build_bc_proto_msg(l->bc_rcvlink, false, 0, &list))
2393		return;
2394	msg_set_bc_ack_invalid(buf_msg(skb_peek(&list)), true);
2395	tipc_link_xmit(l, &list, xmitq);
2396}
2397
2398/* tipc_link_bc_init_rcv - receive initial broadcast synch data from peer
2399 */
2400void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr)
2401{
2402	int mtyp = msg_type(hdr);
2403	u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
2404
2405	if (link_is_up(l))
2406		return;
2407
2408	if (msg_user(hdr) == BCAST_PROTOCOL) {
2409		l->rcv_nxt = peers_snd_nxt;
2410		l->state = LINK_ESTABLISHED;
2411		return;
2412	}
2413
2414	if (l->peer_caps & TIPC_BCAST_SYNCH)
2415		return;
2416
2417	if (msg_peer_node_is_up(hdr))
2418		return;
2419
2420	/* Compatibility: accept older, less safe initial synch data */
2421	if ((mtyp == RESET_MSG) || (mtyp == ACTIVATE_MSG))
2422		l->rcv_nxt = peers_snd_nxt;
2423}
2424
2425/* tipc_link_bc_sync_rcv - update rcv link according to peer's send state
2426 */
2427int tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
2428			  struct sk_buff_head *xmitq)
2429{
2430	u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
2431	int rc = 0;
2432
2433	if (!link_is_up(l))
2434		return rc;
2435
2436	if (!msg_peer_node_is_up(hdr))
2437		return rc;
2438
2439	/* Open when peer acknowledges our bcast init msg (pkt #1) */
2440	if (msg_ack(hdr))
2441		l->bc_peer_is_up = true;
2442
2443	if (!l->bc_peer_is_up)
2444		return rc;
2445
2446	/* Ignore if peers_snd_nxt goes beyond receive window */
2447	if (more(peers_snd_nxt, l->rcv_nxt + l->window))
2448		return rc;
2449
2450	l->snd_nxt = peers_snd_nxt;
2451	if (link_bc_rcv_gap(l))
2452		rc |= TIPC_LINK_SND_STATE;
2453
2454	/* Return now if sender supports nack via STATE messages */
2455	if (l->peer_caps & TIPC_BCAST_STATE_NACK)
2456		return rc;
2457
2458	/* Otherwise, be backwards compatible */
2459
2460	if (!more(peers_snd_nxt, l->rcv_nxt)) {
2461		l->nack_state = BC_NACK_SND_CONDITIONAL;
2462		return 0;
2463	}
2464
2465	/* Don't NACK if one was recently sent or peeked */
2466	if (l->nack_state == BC_NACK_SND_SUPPRESS) {
2467		l->nack_state = BC_NACK_SND_UNCONDITIONAL;
2468		return 0;
2469	}
2470
2471	/* Conditionally delay NACK sending until next synch rcv */
2472	if (l->nack_state == BC_NACK_SND_CONDITIONAL) {
2473		l->nack_state = BC_NACK_SND_UNCONDITIONAL;
2474		if ((peers_snd_nxt - l->rcv_nxt) < TIPC_MIN_LINK_WIN)
2475			return 0;
2476	}
2477
2478	/* Send NACK now but suppress next one */
2479	tipc_link_build_bc_proto_msg(l, true, peers_snd_nxt, xmitq);
2480	l->nack_state = BC_NACK_SND_SUPPRESS;
2481	return 0;
2482}
2483
2484int tipc_link_bc_ack_rcv(struct tipc_link *r, u16 acked, u16 gap,
2485			 struct tipc_gap_ack_blks *ga,
2486			 struct sk_buff_head *xmitq,
2487			 struct sk_buff_head *retrq)
2488{
2489	struct tipc_link *l = r->bc_sndlink;
2490	bool unused = false;
2491	int rc = 0;
2492
2493	if (!link_is_up(r) || !r->bc_peer_is_up)
2494		return 0;
2495
2496	if (gap) {
2497		l->stats.recv_nacks++;
2498		r->stats.recv_nacks++;
2499	}
2500
2501	if (less(acked, r->acked) || (acked == r->acked && !gap && !ga))
2502		return 0;
2503
2504	trace_tipc_link_bc_ack(r, acked, gap, &l->transmq);
2505	tipc_link_advance_transmq(l, r, acked, gap, ga, retrq, &unused, &rc);
2506
2507	tipc_link_advance_backlog(l, xmitq);
2508	if (unlikely(!skb_queue_empty(&l->wakeupq)))
2509		link_prepare_wakeup(l);
2510
2511	return rc;
2512}
2513
2514/* tipc_link_bc_nack_rcv(): receive broadcast nack message
2515 * This function is here for backwards compatibility, since
2516 * no BCAST_PROTOCOL/STATE messages occur from TIPC v2.5.
2517 */
2518int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
2519			  struct sk_buff_head *xmitq)
2520{
2521	struct tipc_msg *hdr = buf_msg(skb);
2522	u32 dnode = msg_destnode(hdr);
2523	int mtyp = msg_type(hdr);
2524	u16 acked = msg_bcast_ack(hdr);
2525	u16 from = acked + 1;
2526	u16 to = msg_bcgap_to(hdr);
2527	u16 peers_snd_nxt = to + 1;
2528	int rc = 0;
2529
2530	kfree_skb(skb);
2531
2532	if (!tipc_link_is_up(l) || !l->bc_peer_is_up)
2533		return 0;
2534
2535	if (mtyp != STATE_MSG)
2536		return 0;
2537
2538	if (dnode == tipc_own_addr(l->net)) {
2539		rc = tipc_link_bc_ack_rcv(l, acked, to - acked, NULL, xmitq,
2540					  xmitq);
2541		l->stats.recv_nacks++;
2542		return rc;
2543	}
2544
2545	/* Msg for other node => suppress own NACK at next sync if applicable */
2546	if (more(peers_snd_nxt, l->rcv_nxt) && !less(l->rcv_nxt, from))
2547		l->nack_state = BC_NACK_SND_SUPPRESS;
2548
2549	return 0;
2550}
2551
2552void tipc_link_set_queue_limits(struct tipc_link *l, u32 min_win, u32 max_win)
2553{
2554	int max_bulk = TIPC_MAX_PUBL / (l->mtu / ITEM_SIZE);
2555
2556	l->min_win = min_win;
2557	l->ssthresh = max_win;
2558	l->max_win = max_win;
2559	l->window = min_win;
2560	l->backlog[TIPC_LOW_IMPORTANCE].limit      = min_win * 2;
2561	l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = min_win * 4;
2562	l->backlog[TIPC_HIGH_IMPORTANCE].limit     = min_win * 6;
2563	l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = min_win * 8;
2564	l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
2565}
2566
2567/**
2568 * tipc_link_reset_stats - reset link statistics
2569 * @l: pointer to link
2570 */
2571void tipc_link_reset_stats(struct tipc_link *l)
2572{
2573	memset(&l->stats, 0, sizeof(l->stats));
2574}
2575
2576static void link_print(struct tipc_link *l, const char *str)
2577{
2578	struct sk_buff *hskb = skb_peek(&l->transmq);
2579	u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt - 1;
2580	u16 tail = l->snd_nxt - 1;
2581
2582	pr_info("%s Link <%s> state %x\n", str, l->name, l->state);
2583	pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n",
2584		skb_queue_len(&l->transmq), head, tail,
2585		skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt);
2586}
2587
2588/* Parse and validate nested (link) properties valid for media, bearer and link
2589 */
2590int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
2591{
2592	int err;
2593
2594	err = nla_parse_nested_deprecated(props, TIPC_NLA_PROP_MAX, prop,
2595					  tipc_nl_prop_policy, NULL);
2596	if (err)
2597		return err;
2598
2599	if (props[TIPC_NLA_PROP_PRIO]) {
2600		u32 prio;
2601
2602		prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
2603		if (prio > TIPC_MAX_LINK_PRI)
2604			return -EINVAL;
2605	}
2606
2607	if (props[TIPC_NLA_PROP_TOL]) {
2608		u32 tol;
2609
2610		tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
2611		if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
2612			return -EINVAL;
2613	}
2614
2615	if (props[TIPC_NLA_PROP_WIN]) {
2616		u32 max_win;
2617
2618		max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
2619		if (max_win < TIPC_DEF_LINK_WIN || max_win > TIPC_MAX_LINK_WIN)
2620			return -EINVAL;
2621	}
2622
2623	return 0;
2624}
2625
2626static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
2627{
2628	int i;
2629	struct nlattr *stats;
2630
2631	struct nla_map {
2632		u32 key;
2633		u32 val;
2634	};
2635
2636	struct nla_map map[] = {
2637		{TIPC_NLA_STATS_RX_INFO, 0},
2638		{TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
2639		{TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
2640		{TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
2641		{TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
2642		{TIPC_NLA_STATS_TX_INFO, 0},
2643		{TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
2644		{TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
2645		{TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
2646		{TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
2647		{TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
2648			s->msg_length_counts : 1},
2649		{TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
2650		{TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
2651		{TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
2652		{TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
2653		{TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
2654		{TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
2655		{TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
2656		{TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
2657		{TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
2658		{TIPC_NLA_STATS_RX_STATES, s->recv_states},
2659		{TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
2660		{TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
2661		{TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
2662		{TIPC_NLA_STATS_TX_STATES, s->sent_states},
2663		{TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
2664		{TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
2665		{TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
2666		{TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
2667		{TIPC_NLA_STATS_DUPLICATES, s->duplicates},
2668		{TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
2669		{TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
2670		{TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
2671			(s->accu_queue_sz / s->queue_sz_counts) : 0}
2672	};
2673
2674	stats = nla_nest_start_noflag(skb, TIPC_NLA_LINK_STATS);
2675	if (!stats)
2676		return -EMSGSIZE;
2677
2678	for (i = 0; i <  ARRAY_SIZE(map); i++)
2679		if (nla_put_u32(skb, map[i].key, map[i].val))
2680			goto msg_full;
2681
2682	nla_nest_end(skb, stats);
2683
2684	return 0;
2685msg_full:
2686	nla_nest_cancel(skb, stats);
2687
2688	return -EMSGSIZE;
2689}
2690
2691/* Caller should hold appropriate locks to protect the link */
2692int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
2693		       struct tipc_link *link, int nlflags)
2694{
2695	u32 self = tipc_own_addr(net);
2696	struct nlattr *attrs;
2697	struct nlattr *prop;
2698	void *hdr;
2699	int err;
2700
2701	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2702			  nlflags, TIPC_NL_LINK_GET);
2703	if (!hdr)
2704		return -EMSGSIZE;
2705
2706	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK);
2707	if (!attrs)
2708		goto msg_full;
2709
2710	if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
2711		goto attr_msg_full;
2712	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST, tipc_cluster_mask(self)))
2713		goto attr_msg_full;
2714	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
2715		goto attr_msg_full;
2716	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->stats.recv_pkts))
2717		goto attr_msg_full;
2718	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->stats.sent_pkts))
2719		goto attr_msg_full;
2720
2721	if (tipc_link_is_up(link))
2722		if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2723			goto attr_msg_full;
2724	if (link->active)
2725		if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
2726			goto attr_msg_full;
2727
2728	prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK_PROP);
2729	if (!prop)
2730		goto attr_msg_full;
2731	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2732		goto prop_msg_full;
2733	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
2734		goto prop_msg_full;
2735	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
2736			link->window))
2737		goto prop_msg_full;
2738	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2739		goto prop_msg_full;
2740	nla_nest_end(msg->skb, prop);
2741
2742	err = __tipc_nl_add_stats(msg->skb, &link->stats);
2743	if (err)
2744		goto attr_msg_full;
2745
2746	nla_nest_end(msg->skb, attrs);
2747	genlmsg_end(msg->skb, hdr);
2748
2749	return 0;
2750
2751prop_msg_full:
2752	nla_nest_cancel(msg->skb, prop);
2753attr_msg_full:
2754	nla_nest_cancel(msg->skb, attrs);
2755msg_full:
2756	genlmsg_cancel(msg->skb, hdr);
2757
2758	return -EMSGSIZE;
2759}
2760
2761static int __tipc_nl_add_bc_link_stat(struct sk_buff *skb,
2762				      struct tipc_stats *stats)
2763{
2764	int i;
2765	struct nlattr *nest;
2766
2767	struct nla_map {
2768		__u32 key;
2769		__u32 val;
2770	};
2771
2772	struct nla_map map[] = {
2773		{TIPC_NLA_STATS_RX_INFO, stats->recv_pkts},
2774		{TIPC_NLA_STATS_RX_FRAGMENTS, stats->recv_fragments},
2775		{TIPC_NLA_STATS_RX_FRAGMENTED, stats->recv_fragmented},
2776		{TIPC_NLA_STATS_RX_BUNDLES, stats->recv_bundles},
2777		{TIPC_NLA_STATS_RX_BUNDLED, stats->recv_bundled},
2778		{TIPC_NLA_STATS_TX_INFO, stats->sent_pkts},
2779		{TIPC_NLA_STATS_TX_FRAGMENTS, stats->sent_fragments},
2780		{TIPC_NLA_STATS_TX_FRAGMENTED, stats->sent_fragmented},
2781		{TIPC_NLA_STATS_TX_BUNDLES, stats->sent_bundles},
2782		{TIPC_NLA_STATS_TX_BUNDLED, stats->sent_bundled},
2783		{TIPC_NLA_STATS_RX_NACKS, stats->recv_nacks},
2784		{TIPC_NLA_STATS_RX_DEFERRED, stats->deferred_recv},
2785		{TIPC_NLA_STATS_TX_NACKS, stats->sent_nacks},
2786		{TIPC_NLA_STATS_TX_ACKS, stats->sent_acks},
2787		{TIPC_NLA_STATS_RETRANSMITTED, stats->retransmitted},
2788		{TIPC_NLA_STATS_DUPLICATES, stats->duplicates},
2789		{TIPC_NLA_STATS_LINK_CONGS, stats->link_congs},
2790		{TIPC_NLA_STATS_MAX_QUEUE, stats->max_queue_sz},
2791		{TIPC_NLA_STATS_AVG_QUEUE, stats->queue_sz_counts ?
2792			(stats->accu_queue_sz / stats->queue_sz_counts) : 0}
2793	};
2794
2795	nest = nla_nest_start_noflag(skb, TIPC_NLA_LINK_STATS);
2796	if (!nest)
2797		return -EMSGSIZE;
2798
2799	for (i = 0; i <  ARRAY_SIZE(map); i++)
2800		if (nla_put_u32(skb, map[i].key, map[i].val))
2801			goto msg_full;
2802
2803	nla_nest_end(skb, nest);
2804
2805	return 0;
2806msg_full:
2807	nla_nest_cancel(skb, nest);
2808
2809	return -EMSGSIZE;
2810}
2811
2812int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg,
2813			struct tipc_link *bcl)
2814{
2815	int err;
2816	void *hdr;
2817	struct nlattr *attrs;
2818	struct nlattr *prop;
2819	u32 bc_mode = tipc_bcast_get_mode(net);
2820	u32 bc_ratio = tipc_bcast_get_broadcast_ratio(net);
2821
2822	if (!bcl)
2823		return 0;
2824
2825	tipc_bcast_lock(net);
2826
2827	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2828			  NLM_F_MULTI, TIPC_NL_LINK_GET);
2829	if (!hdr) {
2830		tipc_bcast_unlock(net);
2831		return -EMSGSIZE;
2832	}
2833
2834	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK);
2835	if (!attrs)
2836		goto msg_full;
2837
2838	/* The broadcast link is always up */
2839	if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2840		goto attr_msg_full;
2841
2842	if (nla_put_flag(msg->skb, TIPC_NLA_LINK_BROADCAST))
2843		goto attr_msg_full;
2844	if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, bcl->name))
2845		goto attr_msg_full;
2846	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, 0))
2847		goto attr_msg_full;
2848	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, 0))
2849		goto attr_msg_full;
2850
2851	prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK_PROP);
2852	if (!prop)
2853		goto attr_msg_full;
2854	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bcl->max_win))
2855		goto prop_msg_full;
2856	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_BROADCAST, bc_mode))
2857		goto prop_msg_full;
2858	if (bc_mode & BCLINK_MODE_SEL)
2859		if (nla_put_u32(msg->skb, TIPC_NLA_PROP_BROADCAST_RATIO,
2860				bc_ratio))
2861			goto prop_msg_full;
2862	nla_nest_end(msg->skb, prop);
2863
2864	err = __tipc_nl_add_bc_link_stat(msg->skb, &bcl->stats);
2865	if (err)
2866		goto attr_msg_full;
2867
2868	tipc_bcast_unlock(net);
2869	nla_nest_end(msg->skb, attrs);
2870	genlmsg_end(msg->skb, hdr);
2871
2872	return 0;
2873
2874prop_msg_full:
2875	nla_nest_cancel(msg->skb, prop);
2876attr_msg_full:
2877	nla_nest_cancel(msg->skb, attrs);
2878msg_full:
2879	tipc_bcast_unlock(net);
2880	genlmsg_cancel(msg->skb, hdr);
2881
2882	return -EMSGSIZE;
2883}
2884
2885void tipc_link_set_tolerance(struct tipc_link *l, u32 tol,
2886			     struct sk_buff_head *xmitq)
2887{
2888	l->tolerance = tol;
2889	if (l->bc_rcvlink)
2890		l->bc_rcvlink->tolerance = tol;
2891	if (link_is_up(l))
2892		tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, tol, 0, xmitq);
2893}
2894
2895void tipc_link_set_prio(struct tipc_link *l, u32 prio,
2896			struct sk_buff_head *xmitq)
2897{
2898	l->priority = prio;
2899	tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, prio, xmitq);
2900}
2901
2902void tipc_link_set_abort_limit(struct tipc_link *l, u32 limit)
2903{
2904	l->abort_limit = limit;
2905}
2906
2907/**
2908 * tipc_link_dump - dump TIPC link data
2909 * @l: tipc link to be dumped
2910 * @dqueues: bitmask to decide if any link queue to be dumped?
2911 *           - TIPC_DUMP_NONE: don't dump link queues
2912 *           - TIPC_DUMP_TRANSMQ: dump link transmq queue
2913 *           - TIPC_DUMP_BACKLOGQ: dump link backlog queue
2914 *           - TIPC_DUMP_DEFERDQ: dump link deferd queue
2915 *           - TIPC_DUMP_INPUTQ: dump link input queue
2916 *           - TIPC_DUMP_WAKEUP: dump link wakeup queue
2917 *           - TIPC_DUMP_ALL: dump all the link queues above
2918 * @buf: returned buffer of dump data in format
2919 */
2920int tipc_link_dump(struct tipc_link *l, u16 dqueues, char *buf)
2921{
2922	int i = 0;
2923	size_t sz = (dqueues) ? LINK_LMAX : LINK_LMIN;
2924	struct sk_buff_head *list;
2925	struct sk_buff *hskb, *tskb;
2926	u32 len;
2927
2928	if (!l) {
2929		i += scnprintf(buf, sz, "link data: (null)\n");
2930		return i;
2931	}
2932
2933	i += scnprintf(buf, sz, "link data: %x", l->addr);
2934	i += scnprintf(buf + i, sz - i, " %x", l->state);
2935	i += scnprintf(buf + i, sz - i, " %u", l->in_session);
2936	i += scnprintf(buf + i, sz - i, " %u", l->session);
2937	i += scnprintf(buf + i, sz - i, " %u", l->peer_session);
2938	i += scnprintf(buf + i, sz - i, " %u", l->snd_nxt);
2939	i += scnprintf(buf + i, sz - i, " %u", l->rcv_nxt);
2940	i += scnprintf(buf + i, sz - i, " %u", l->snd_nxt_state);
2941	i += scnprintf(buf + i, sz - i, " %u", l->rcv_nxt_state);
2942	i += scnprintf(buf + i, sz - i, " %x", l->peer_caps);
2943	i += scnprintf(buf + i, sz - i, " %u", l->silent_intv_cnt);
2944	i += scnprintf(buf + i, sz - i, " %u", l->rst_cnt);
2945	i += scnprintf(buf + i, sz - i, " %u", 0);
2946	i += scnprintf(buf + i, sz - i, " %u", 0);
2947	i += scnprintf(buf + i, sz - i, " %u", l->acked);
2948
2949	list = &l->transmq;
2950	len = skb_queue_len(list);
2951	hskb = skb_peek(list);
2952	tskb = skb_peek_tail(list);
2953	i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
2954		       (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2955		       (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2956
2957	list = &l->deferdq;
2958	len = skb_queue_len(list);
2959	hskb = skb_peek(list);
2960	tskb = skb_peek_tail(list);
2961	i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
2962		       (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2963		       (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2964
2965	list = &l->backlogq;
2966	len = skb_queue_len(list);
2967	hskb = skb_peek(list);
2968	tskb = skb_peek_tail(list);
2969	i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
2970		       (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2971		       (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2972
2973	list = l->inputq;
2974	len = skb_queue_len(list);
2975	hskb = skb_peek(list);
2976	tskb = skb_peek_tail(list);
2977	i += scnprintf(buf + i, sz - i, " | %u %u %u\n", len,
2978		       (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2979		       (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2980
2981	if (dqueues & TIPC_DUMP_TRANSMQ) {
2982		i += scnprintf(buf + i, sz - i, "transmq: ");
2983		i += tipc_list_dump(&l->transmq, false, buf + i);
2984	}
2985	if (dqueues & TIPC_DUMP_BACKLOGQ) {
2986		i += scnprintf(buf + i, sz - i,
2987			       "backlogq: <%u %u %u %u %u>, ",
2988			       l->backlog[TIPC_LOW_IMPORTANCE].len,
2989			       l->backlog[TIPC_MEDIUM_IMPORTANCE].len,
2990			       l->backlog[TIPC_HIGH_IMPORTANCE].len,
2991			       l->backlog[TIPC_CRITICAL_IMPORTANCE].len,
2992			       l->backlog[TIPC_SYSTEM_IMPORTANCE].len);
2993		i += tipc_list_dump(&l->backlogq, false, buf + i);
2994	}
2995	if (dqueues & TIPC_DUMP_DEFERDQ) {
2996		i += scnprintf(buf + i, sz - i, "deferdq: ");
2997		i += tipc_list_dump(&l->deferdq, false, buf + i);
2998	}
2999	if (dqueues & TIPC_DUMP_INPUTQ) {
3000		i += scnprintf(buf + i, sz - i, "inputq: ");
3001		i += tipc_list_dump(l->inputq, false, buf + i);
3002	}
3003	if (dqueues & TIPC_DUMP_WAKEUP) {
3004		i += scnprintf(buf + i, sz - i, "wakeup: ");
3005		i += tipc_list_dump(&l->wakeupq, false, buf + i);
3006	}
3007
3008	return i;
3009}
3010