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