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