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