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1/*
2 * net/tipc/link.c: TIPC link code
3 *
4 * Copyright (c) 1996-2007, 2012-2016, Ericsson AB
5 * Copyright (c) 2004-2007, 2010-2013, Wind River Systems
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the names of the copyright holders nor the names of its
17 * contributors may be used to endorse or promote products derived from
18 * this software without specific prior written permission.
19 *
20 * Alternatively, this software may be distributed under the terms of the
21 * GNU General Public License ("GPL") version 2 as published by the Free
22 * Software Foundation.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34 * POSSIBILITY OF SUCH DAMAGE.
35 */
36
37#include "core.h"
38#include "subscr.h"
39#include "link.h"
40#include "bcast.h"
41#include "socket.h"
42#include "name_distr.h"
43#include "discover.h"
44#include "netlink.h"
45#include "monitor.h"
46
47#include <linux/pkt_sched.h>
48
49struct tipc_stats {
50 u32 sent_pkts;
51 u32 recv_pkts;
52 u32 sent_states;
53 u32 recv_states;
54 u32 sent_probes;
55 u32 recv_probes;
56 u32 sent_nacks;
57 u32 recv_nacks;
58 u32 sent_acks;
59 u32 sent_bundled;
60 u32 sent_bundles;
61 u32 recv_bundled;
62 u32 recv_bundles;
63 u32 retransmitted;
64 u32 sent_fragmented;
65 u32 sent_fragments;
66 u32 recv_fragmented;
67 u32 recv_fragments;
68 u32 link_congs; /* # port sends blocked by congestion */
69 u32 deferred_recv;
70 u32 duplicates;
71 u32 max_queue_sz; /* send queue size high water mark */
72 u32 accu_queue_sz; /* used for send queue size profiling */
73 u32 queue_sz_counts; /* used for send queue size profiling */
74 u32 msg_length_counts; /* used for message length profiling */
75 u32 msg_lengths_total; /* used for message length profiling */
76 u32 msg_length_profile[7]; /* used for msg. length profiling */
77};
78
79/**
80 * struct tipc_link - TIPC link data structure
81 * @addr: network address of link's peer node
82 * @name: link name character string
83 * @media_addr: media address to use when sending messages over link
84 * @timer: link timer
85 * @net: pointer to namespace struct
86 * @refcnt: reference counter for permanent references (owner node & timer)
87 * @peer_session: link session # being used by peer end of link
88 * @peer_bearer_id: bearer id used by link's peer endpoint
89 * @bearer_id: local bearer id used by link
90 * @tolerance: minimum link continuity loss needed to reset link [in ms]
91 * @abort_limit: # of unacknowledged continuity probes needed to reset link
92 * @state: current state of link FSM
93 * @peer_caps: bitmap describing capabilities of peer node
94 * @silent_intv_cnt: # of timer intervals without any reception from peer
95 * @proto_msg: template for control messages generated by link
96 * @pmsg: convenience pointer to "proto_msg" field
97 * @priority: current link priority
98 * @net_plane: current link network plane ('A' through 'H')
99 * @mon_state: cookie with information needed by link monitor
100 * @backlog_limit: backlog queue congestion thresholds (indexed by importance)
101 * @exp_msg_count: # of tunnelled messages expected during link changeover
102 * @reset_rcv_checkpt: seq # of last acknowledged message at time of link reset
103 * @mtu: current maximum packet size for this link
104 * @advertised_mtu: advertised own mtu when link is being established
105 * @transmitq: queue for sent, non-acked messages
106 * @backlogq: queue for messages waiting to be sent
107 * @snt_nxt: next sequence number to use for outbound messages
108 * @last_retransmitted: sequence number of most recently retransmitted message
109 * @stale_count: # of identical retransmit requests made by peer
110 * @ackers: # of peers that needs to ack each packet before it can be released
111 * @acked: # last packet acked by a certain peer. Used for broadcast.
112 * @rcv_nxt: next sequence number to expect for inbound messages
113 * @deferred_queue: deferred queue saved OOS b'cast message received from node
114 * @unacked_window: # of inbound messages rx'd without ack'ing back to peer
115 * @inputq: buffer queue for messages to be delivered upwards
116 * @namedq: buffer queue for name table messages to be delivered upwards
117 * @next_out: ptr to first unsent outbound message in queue
118 * @wakeupq: linked list of wakeup msgs waiting for link congestion to abate
119 * @long_msg_seq_no: next identifier to use for outbound fragmented messages
120 * @reasm_buf: head of partially reassembled inbound message fragments
121 * @bc_rcvr: marks that this is a broadcast receiver link
122 * @stats: collects statistics regarding link activity
123 */
124struct tipc_link {
125 u32 addr;
126 char name[TIPC_MAX_LINK_NAME];
127 struct net *net;
128
129 /* Management and link supervision data */
130 u32 peer_session;
131 u32 session;
132 u32 peer_bearer_id;
133 u32 bearer_id;
134 u32 tolerance;
135 u32 abort_limit;
136 u32 state;
137 u16 peer_caps;
138 bool active;
139 u32 silent_intv_cnt;
140 char if_name[TIPC_MAX_IF_NAME];
141 u32 priority;
142 char net_plane;
143 struct tipc_mon_state mon_state;
144 u16 rst_cnt;
145
146 /* Failover/synch */
147 u16 drop_point;
148 struct sk_buff *failover_reasm_skb;
149
150 /* Max packet negotiation */
151 u16 mtu;
152 u16 advertised_mtu;
153
154 /* Sending */
155 struct sk_buff_head transmq;
156 struct sk_buff_head backlogq;
157 struct {
158 u16 len;
159 u16 limit;
160 } backlog[5];
161 u16 snd_nxt;
162 u16 last_retransm;
163 u16 window;
164 u32 stale_count;
165
166 /* Reception */
167 u16 rcv_nxt;
168 u32 rcv_unacked;
169 struct sk_buff_head deferdq;
170 struct sk_buff_head *inputq;
171 struct sk_buff_head *namedq;
172
173 /* Congestion handling */
174 struct sk_buff_head wakeupq;
175
176 /* Fragmentation/reassembly */
177 struct sk_buff *reasm_buf;
178
179 /* Broadcast */
180 u16 ackers;
181 u16 acked;
182 struct tipc_link *bc_rcvlink;
183 struct tipc_link *bc_sndlink;
184 unsigned long prev_retr;
185 u16 prev_from;
186 u16 prev_to;
187 u8 nack_state;
188 bool bc_peer_is_up;
189
190 /* Statistics */
191 struct tipc_stats stats;
192};
193
194/*
195 * Error message prefixes
196 */
197static const char *link_co_err = "Link tunneling error, ";
198static const char *link_rst_msg = "Resetting link ";
199
200/* Send states for broadcast NACKs
201 */
202enum {
203 BC_NACK_SND_CONDITIONAL,
204 BC_NACK_SND_UNCONDITIONAL,
205 BC_NACK_SND_SUPPRESS,
206};
207
208#define TIPC_BC_RETR_LIMIT 10 /* [ms] */
209
210/*
211 * Interval between NACKs when packets arrive out of order
212 */
213#define TIPC_NACK_INTV (TIPC_MIN_LINK_WIN * 2)
214
215/* Wildcard value for link session numbers. When it is known that
216 * peer endpoint is down, any session number must be accepted.
217 */
218#define ANY_SESSION 0x10000
219
220/* Link FSM states:
221 */
222enum {
223 LINK_ESTABLISHED = 0xe,
224 LINK_ESTABLISHING = 0xe << 4,
225 LINK_RESET = 0x1 << 8,
226 LINK_RESETTING = 0x2 << 12,
227 LINK_PEER_RESET = 0xd << 16,
228 LINK_FAILINGOVER = 0xf << 20,
229 LINK_SYNCHING = 0xc << 24
230};
231
232/* Link FSM state checking routines
233 */
234static int link_is_up(struct tipc_link *l)
235{
236 return l->state & (LINK_ESTABLISHED | LINK_SYNCHING);
237}
238
239static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
240 struct sk_buff_head *xmitq);
241static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
242 u16 rcvgap, int tolerance, int priority,
243 struct sk_buff_head *xmitq);
244static void link_print(struct tipc_link *l, const char *str);
245static int tipc_link_build_nack_msg(struct tipc_link *l,
246 struct sk_buff_head *xmitq);
247static void tipc_link_build_bc_init_msg(struct tipc_link *l,
248 struct sk_buff_head *xmitq);
249static bool tipc_link_release_pkts(struct tipc_link *l, u16 to);
250
251/*
252 * Simple non-static link routines (i.e. referenced outside this file)
253 */
254bool tipc_link_is_up(struct tipc_link *l)
255{
256 return link_is_up(l);
257}
258
259bool tipc_link_peer_is_down(struct tipc_link *l)
260{
261 return l->state == LINK_PEER_RESET;
262}
263
264bool tipc_link_is_reset(struct tipc_link *l)
265{
266 return l->state & (LINK_RESET | LINK_FAILINGOVER | LINK_ESTABLISHING);
267}
268
269bool tipc_link_is_establishing(struct tipc_link *l)
270{
271 return l->state == LINK_ESTABLISHING;
272}
273
274bool tipc_link_is_synching(struct tipc_link *l)
275{
276 return l->state == LINK_SYNCHING;
277}
278
279bool tipc_link_is_failingover(struct tipc_link *l)
280{
281 return l->state == LINK_FAILINGOVER;
282}
283
284bool tipc_link_is_blocked(struct tipc_link *l)
285{
286 return l->state & (LINK_RESETTING | LINK_PEER_RESET | LINK_FAILINGOVER);
287}
288
289static bool link_is_bc_sndlink(struct tipc_link *l)
290{
291 return !l->bc_sndlink;
292}
293
294static bool link_is_bc_rcvlink(struct tipc_link *l)
295{
296 return ((l->bc_rcvlink == l) && !link_is_bc_sndlink(l));
297}
298
299int tipc_link_is_active(struct tipc_link *l)
300{
301 return l->active;
302}
303
304void tipc_link_set_active(struct tipc_link *l, bool active)
305{
306 l->active = active;
307}
308
309u32 tipc_link_id(struct tipc_link *l)
310{
311 return l->peer_bearer_id << 16 | l->bearer_id;
312}
313
314int tipc_link_window(struct tipc_link *l)
315{
316 return l->window;
317}
318
319int tipc_link_prio(struct tipc_link *l)
320{
321 return l->priority;
322}
323
324unsigned long tipc_link_tolerance(struct tipc_link *l)
325{
326 return l->tolerance;
327}
328
329struct sk_buff_head *tipc_link_inputq(struct tipc_link *l)
330{
331 return l->inputq;
332}
333
334char tipc_link_plane(struct tipc_link *l)
335{
336 return l->net_plane;
337}
338
339void tipc_link_add_bc_peer(struct tipc_link *snd_l,
340 struct tipc_link *uc_l,
341 struct sk_buff_head *xmitq)
342{
343 struct tipc_link *rcv_l = uc_l->bc_rcvlink;
344
345 snd_l->ackers++;
346 rcv_l->acked = snd_l->snd_nxt - 1;
347 snd_l->state = LINK_ESTABLISHED;
348 tipc_link_build_bc_init_msg(uc_l, xmitq);
349}
350
351void tipc_link_remove_bc_peer(struct tipc_link *snd_l,
352 struct tipc_link *rcv_l,
353 struct sk_buff_head *xmitq)
354{
355 u16 ack = snd_l->snd_nxt - 1;
356
357 snd_l->ackers--;
358 rcv_l->bc_peer_is_up = true;
359 rcv_l->state = LINK_ESTABLISHED;
360 tipc_link_bc_ack_rcv(rcv_l, ack, xmitq);
361 tipc_link_reset(rcv_l);
362 rcv_l->state = LINK_RESET;
363 if (!snd_l->ackers) {
364 tipc_link_reset(snd_l);
365 snd_l->state = LINK_RESET;
366 __skb_queue_purge(xmitq);
367 }
368}
369
370int tipc_link_bc_peers(struct tipc_link *l)
371{
372 return l->ackers;
373}
374
375u16 link_bc_rcv_gap(struct tipc_link *l)
376{
377 struct sk_buff *skb = skb_peek(&l->deferdq);
378 u16 gap = 0;
379
380 if (more(l->snd_nxt, l->rcv_nxt))
381 gap = l->snd_nxt - l->rcv_nxt;
382 if (skb)
383 gap = buf_seqno(skb) - l->rcv_nxt;
384 return gap;
385}
386
387void tipc_link_set_mtu(struct tipc_link *l, int mtu)
388{
389 l->mtu = mtu;
390}
391
392int tipc_link_mtu(struct tipc_link *l)
393{
394 return l->mtu;
395}
396
397u16 tipc_link_rcv_nxt(struct tipc_link *l)
398{
399 return l->rcv_nxt;
400}
401
402u16 tipc_link_acked(struct tipc_link *l)
403{
404 return l->acked;
405}
406
407char *tipc_link_name(struct tipc_link *l)
408{
409 return l->name;
410}
411
412/**
413 * tipc_link_create - create a new link
414 * @n: pointer to associated node
415 * @if_name: associated interface name
416 * @bearer_id: id (index) of associated bearer
417 * @tolerance: link tolerance to be used by link
418 * @net_plane: network plane (A,B,c..) this link belongs to
419 * @mtu: mtu to be advertised by link
420 * @priority: priority to be used by link
421 * @window: send window to be used by link
422 * @session: session to be used by link
423 * @ownnode: identity of own node
424 * @peer: node id of peer node
425 * @peer_caps: bitmap describing peer node capabilities
426 * @bc_sndlink: the namespace global link used for broadcast sending
427 * @bc_rcvlink: the peer specific link used for broadcast reception
428 * @inputq: queue to put messages ready for delivery
429 * @namedq: queue to put binding table update messages ready for delivery
430 * @link: return value, pointer to put the created link
431 *
432 * Returns true if link was created, otherwise false
433 */
434bool tipc_link_create(struct net *net, char *if_name, int bearer_id,
435 int tolerance, char net_plane, u32 mtu, int priority,
436 int window, u32 session, u32 ownnode, u32 peer,
437 u16 peer_caps,
438 struct tipc_link *bc_sndlink,
439 struct tipc_link *bc_rcvlink,
440 struct sk_buff_head *inputq,
441 struct sk_buff_head *namedq,
442 struct tipc_link **link)
443{
444 struct tipc_link *l;
445
446 l = kzalloc(sizeof(*l), GFP_ATOMIC);
447 if (!l)
448 return false;
449 *link = l;
450 l->session = session;
451
452 /* Note: peer i/f name is completed by reset/activate message */
453 sprintf(l->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
454 tipc_zone(ownnode), tipc_cluster(ownnode), tipc_node(ownnode),
455 if_name, tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
456 strcpy(l->if_name, if_name);
457 l->addr = peer;
458 l->peer_caps = peer_caps;
459 l->net = net;
460 l->peer_session = ANY_SESSION;
461 l->bearer_id = bearer_id;
462 l->tolerance = tolerance;
463 l->net_plane = net_plane;
464 l->advertised_mtu = mtu;
465 l->mtu = mtu;
466 l->priority = priority;
467 tipc_link_set_queue_limits(l, window);
468 l->ackers = 1;
469 l->bc_sndlink = bc_sndlink;
470 l->bc_rcvlink = bc_rcvlink;
471 l->inputq = inputq;
472 l->namedq = namedq;
473 l->state = LINK_RESETTING;
474 __skb_queue_head_init(&l->transmq);
475 __skb_queue_head_init(&l->backlogq);
476 __skb_queue_head_init(&l->deferdq);
477 skb_queue_head_init(&l->wakeupq);
478 skb_queue_head_init(l->inputq);
479 return true;
480}
481
482/**
483 * tipc_link_bc_create - create new link to be used for broadcast
484 * @n: pointer to associated node
485 * @mtu: mtu to be used
486 * @window: send window to be used
487 * @inputq: queue to put messages ready for delivery
488 * @namedq: queue to put binding table update messages ready for delivery
489 * @link: return value, pointer to put the created link
490 *
491 * Returns true if link was created, otherwise false
492 */
493bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer,
494 int mtu, int window, u16 peer_caps,
495 struct sk_buff_head *inputq,
496 struct sk_buff_head *namedq,
497 struct tipc_link *bc_sndlink,
498 struct tipc_link **link)
499{
500 struct tipc_link *l;
501
502 if (!tipc_link_create(net, "", MAX_BEARERS, 0, 'Z', mtu, 0, window,
503 0, ownnode, peer, peer_caps, bc_sndlink,
504 NULL, inputq, namedq, link))
505 return false;
506
507 l = *link;
508 strcpy(l->name, tipc_bclink_name);
509 tipc_link_reset(l);
510 l->state = LINK_RESET;
511 l->ackers = 0;
512 l->bc_rcvlink = l;
513
514 /* Broadcast send link is always up */
515 if (link_is_bc_sndlink(l))
516 l->state = LINK_ESTABLISHED;
517
518 return true;
519}
520
521/**
522 * tipc_link_fsm_evt - link finite state machine
523 * @l: pointer to link
524 * @evt: state machine event to be processed
525 */
526int tipc_link_fsm_evt(struct tipc_link *l, int evt)
527{
528 int rc = 0;
529
530 switch (l->state) {
531 case LINK_RESETTING:
532 switch (evt) {
533 case LINK_PEER_RESET_EVT:
534 l->state = LINK_PEER_RESET;
535 break;
536 case LINK_RESET_EVT:
537 l->state = LINK_RESET;
538 break;
539 case LINK_FAILURE_EVT:
540 case LINK_FAILOVER_BEGIN_EVT:
541 case LINK_ESTABLISH_EVT:
542 case LINK_FAILOVER_END_EVT:
543 case LINK_SYNCH_BEGIN_EVT:
544 case LINK_SYNCH_END_EVT:
545 default:
546 goto illegal_evt;
547 }
548 break;
549 case LINK_RESET:
550 switch (evt) {
551 case LINK_PEER_RESET_EVT:
552 l->state = LINK_ESTABLISHING;
553 break;
554 case LINK_FAILOVER_BEGIN_EVT:
555 l->state = LINK_FAILINGOVER;
556 case LINK_FAILURE_EVT:
557 case LINK_RESET_EVT:
558 case LINK_ESTABLISH_EVT:
559 case LINK_FAILOVER_END_EVT:
560 break;
561 case LINK_SYNCH_BEGIN_EVT:
562 case LINK_SYNCH_END_EVT:
563 default:
564 goto illegal_evt;
565 }
566 break;
567 case LINK_PEER_RESET:
568 switch (evt) {
569 case LINK_RESET_EVT:
570 l->state = LINK_ESTABLISHING;
571 break;
572 case LINK_PEER_RESET_EVT:
573 case LINK_ESTABLISH_EVT:
574 case LINK_FAILURE_EVT:
575 break;
576 case LINK_SYNCH_BEGIN_EVT:
577 case LINK_SYNCH_END_EVT:
578 case LINK_FAILOVER_BEGIN_EVT:
579 case LINK_FAILOVER_END_EVT:
580 default:
581 goto illegal_evt;
582 }
583 break;
584 case LINK_FAILINGOVER:
585 switch (evt) {
586 case LINK_FAILOVER_END_EVT:
587 l->state = LINK_RESET;
588 break;
589 case LINK_PEER_RESET_EVT:
590 case LINK_RESET_EVT:
591 case LINK_ESTABLISH_EVT:
592 case LINK_FAILURE_EVT:
593 break;
594 case LINK_FAILOVER_BEGIN_EVT:
595 case LINK_SYNCH_BEGIN_EVT:
596 case LINK_SYNCH_END_EVT:
597 default:
598 goto illegal_evt;
599 }
600 break;
601 case LINK_ESTABLISHING:
602 switch (evt) {
603 case LINK_ESTABLISH_EVT:
604 l->state = LINK_ESTABLISHED;
605 break;
606 case LINK_FAILOVER_BEGIN_EVT:
607 l->state = LINK_FAILINGOVER;
608 break;
609 case LINK_RESET_EVT:
610 l->state = LINK_RESET;
611 break;
612 case LINK_FAILURE_EVT:
613 case LINK_PEER_RESET_EVT:
614 case LINK_SYNCH_BEGIN_EVT:
615 case LINK_FAILOVER_END_EVT:
616 break;
617 case LINK_SYNCH_END_EVT:
618 default:
619 goto illegal_evt;
620 }
621 break;
622 case LINK_ESTABLISHED:
623 switch (evt) {
624 case LINK_PEER_RESET_EVT:
625 l->state = LINK_PEER_RESET;
626 rc |= TIPC_LINK_DOWN_EVT;
627 break;
628 case LINK_FAILURE_EVT:
629 l->state = LINK_RESETTING;
630 rc |= TIPC_LINK_DOWN_EVT;
631 break;
632 case LINK_RESET_EVT:
633 l->state = LINK_RESET;
634 break;
635 case LINK_ESTABLISH_EVT:
636 case LINK_SYNCH_END_EVT:
637 break;
638 case LINK_SYNCH_BEGIN_EVT:
639 l->state = LINK_SYNCHING;
640 break;
641 case LINK_FAILOVER_BEGIN_EVT:
642 case LINK_FAILOVER_END_EVT:
643 default:
644 goto illegal_evt;
645 }
646 break;
647 case LINK_SYNCHING:
648 switch (evt) {
649 case LINK_PEER_RESET_EVT:
650 l->state = LINK_PEER_RESET;
651 rc |= TIPC_LINK_DOWN_EVT;
652 break;
653 case LINK_FAILURE_EVT:
654 l->state = LINK_RESETTING;
655 rc |= TIPC_LINK_DOWN_EVT;
656 break;
657 case LINK_RESET_EVT:
658 l->state = LINK_RESET;
659 break;
660 case LINK_ESTABLISH_EVT:
661 case LINK_SYNCH_BEGIN_EVT:
662 break;
663 case LINK_SYNCH_END_EVT:
664 l->state = LINK_ESTABLISHED;
665 break;
666 case LINK_FAILOVER_BEGIN_EVT:
667 case LINK_FAILOVER_END_EVT:
668 default:
669 goto illegal_evt;
670 }
671 break;
672 default:
673 pr_err("Unknown FSM state %x in %s\n", l->state, l->name);
674 }
675 return rc;
676illegal_evt:
677 pr_err("Illegal FSM event %x in state %x on link %s\n",
678 evt, l->state, l->name);
679 return rc;
680}
681
682/* link_profile_stats - update statistical profiling of traffic
683 */
684static void link_profile_stats(struct tipc_link *l)
685{
686 struct sk_buff *skb;
687 struct tipc_msg *msg;
688 int length;
689
690 /* Update counters used in statistical profiling of send traffic */
691 l->stats.accu_queue_sz += skb_queue_len(&l->transmq);
692 l->stats.queue_sz_counts++;
693
694 skb = skb_peek(&l->transmq);
695 if (!skb)
696 return;
697 msg = buf_msg(skb);
698 length = msg_size(msg);
699
700 if (msg_user(msg) == MSG_FRAGMENTER) {
701 if (msg_type(msg) != FIRST_FRAGMENT)
702 return;
703 length = msg_size(msg_get_wrapped(msg));
704 }
705 l->stats.msg_lengths_total += length;
706 l->stats.msg_length_counts++;
707 if (length <= 64)
708 l->stats.msg_length_profile[0]++;
709 else if (length <= 256)
710 l->stats.msg_length_profile[1]++;
711 else if (length <= 1024)
712 l->stats.msg_length_profile[2]++;
713 else if (length <= 4096)
714 l->stats.msg_length_profile[3]++;
715 else if (length <= 16384)
716 l->stats.msg_length_profile[4]++;
717 else if (length <= 32768)
718 l->stats.msg_length_profile[5]++;
719 else
720 l->stats.msg_length_profile[6]++;
721}
722
723/* tipc_link_timeout - perform periodic task as instructed from node timeout
724 */
725int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
726{
727 int mtyp = 0;
728 int rc = 0;
729 bool state = false;
730 bool probe = false;
731 bool setup = false;
732 u16 bc_snt = l->bc_sndlink->snd_nxt - 1;
733 u16 bc_acked = l->bc_rcvlink->acked;
734 struct tipc_mon_state *mstate = &l->mon_state;
735
736 switch (l->state) {
737 case LINK_ESTABLISHED:
738 case LINK_SYNCHING:
739 mtyp = STATE_MSG;
740 link_profile_stats(l);
741 tipc_mon_get_state(l->net, l->addr, mstate, l->bearer_id);
742 if (mstate->reset || (l->silent_intv_cnt > l->abort_limit))
743 return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
744 state = bc_acked != bc_snt;
745 state |= l->bc_rcvlink->rcv_unacked;
746 state |= l->rcv_unacked;
747 state |= !skb_queue_empty(&l->transmq);
748 state |= !skb_queue_empty(&l->deferdq);
749 probe = mstate->probing;
750 probe |= l->silent_intv_cnt;
751 if (probe || mstate->monitoring)
752 l->silent_intv_cnt++;
753 break;
754 case LINK_RESET:
755 setup = l->rst_cnt++ <= 4;
756 setup |= !(l->rst_cnt % 16);
757 mtyp = RESET_MSG;
758 break;
759 case LINK_ESTABLISHING:
760 setup = true;
761 mtyp = ACTIVATE_MSG;
762 break;
763 case LINK_PEER_RESET:
764 case LINK_RESETTING:
765 case LINK_FAILINGOVER:
766 break;
767 default:
768 break;
769 }
770
771 if (state || probe || setup)
772 tipc_link_build_proto_msg(l, mtyp, probe, 0, 0, 0, xmitq);
773
774 return rc;
775}
776
777/**
778 * link_schedule_user - schedule a message sender for wakeup after congestion
779 * @link: congested link
780 * @list: message that was attempted sent
781 * Create pseudo msg to send back to user when congestion abates
782 * Does not consume buffer list
783 */
784static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list)
785{
786 struct tipc_msg *msg = buf_msg(skb_peek(list));
787 int imp = msg_importance(msg);
788 u32 oport = msg_origport(msg);
789 u32 addr = tipc_own_addr(link->net);
790 struct sk_buff *skb;
791
792 /* This really cannot happen... */
793 if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
794 pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
795 return -ENOBUFS;
796 }
797 /* Non-blocking sender: */
798 if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending)
799 return -ELINKCONG;
800
801 /* Create and schedule wakeup pseudo message */
802 skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
803 addr, addr, oport, 0, 0);
804 if (!skb)
805 return -ENOBUFS;
806 TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list);
807 TIPC_SKB_CB(skb)->chain_imp = imp;
808 skb_queue_tail(&link->wakeupq, skb);
809 link->stats.link_congs++;
810 return -ELINKCONG;
811}
812
813/**
814 * link_prepare_wakeup - prepare users for wakeup after congestion
815 * @link: congested link
816 * Move a number of waiting users, as permitted by available space in
817 * the send queue, from link wait queue to node wait queue for wakeup
818 */
819void link_prepare_wakeup(struct tipc_link *l)
820{
821 int pnd[TIPC_SYSTEM_IMPORTANCE + 1] = {0,};
822 int imp, lim;
823 struct sk_buff *skb, *tmp;
824
825 skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
826 imp = TIPC_SKB_CB(skb)->chain_imp;
827 lim = l->backlog[imp].limit;
828 pnd[imp] += TIPC_SKB_CB(skb)->chain_sz;
829 if ((pnd[imp] + l->backlog[imp].len) >= lim)
830 break;
831 skb_unlink(skb, &l->wakeupq);
832 skb_queue_tail(l->inputq, skb);
833 }
834}
835
836void tipc_link_reset(struct tipc_link *l)
837{
838 l->peer_session = ANY_SESSION;
839 l->session++;
840 l->mtu = l->advertised_mtu;
841 __skb_queue_purge(&l->transmq);
842 __skb_queue_purge(&l->deferdq);
843 skb_queue_splice_init(&l->wakeupq, l->inputq);
844 __skb_queue_purge(&l->backlogq);
845 l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
846 l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;
847 l->backlog[TIPC_HIGH_IMPORTANCE].len = 0;
848 l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0;
849 l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0;
850 kfree_skb(l->reasm_buf);
851 kfree_skb(l->failover_reasm_skb);
852 l->reasm_buf = NULL;
853 l->failover_reasm_skb = NULL;
854 l->rcv_unacked = 0;
855 l->snd_nxt = 1;
856 l->rcv_nxt = 1;
857 l->acked = 0;
858 l->silent_intv_cnt = 0;
859 l->rst_cnt = 0;
860 l->stale_count = 0;
861 l->bc_peer_is_up = false;
862 memset(&l->mon_state, 0, sizeof(l->mon_state));
863 tipc_link_reset_stats(l);
864}
865
866/**
867 * tipc_link_xmit(): enqueue buffer list according to queue situation
868 * @link: link to use
869 * @list: chain of buffers containing message
870 * @xmitq: returned list of packets to be sent by caller
871 *
872 * Consumes the buffer chain, except when returning -ELINKCONG,
873 * since the caller then may want to make more send attempts.
874 * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
875 * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
876 */
877int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
878 struct sk_buff_head *xmitq)
879{
880 struct tipc_msg *hdr = buf_msg(skb_peek(list));
881 unsigned int maxwin = l->window;
882 unsigned int i, imp = msg_importance(hdr);
883 unsigned int mtu = l->mtu;
884 u16 ack = l->rcv_nxt - 1;
885 u16 seqno = l->snd_nxt;
886 u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
887 struct sk_buff_head *transmq = &l->transmq;
888 struct sk_buff_head *backlogq = &l->backlogq;
889 struct sk_buff *skb, *_skb, *bskb;
890 int pkt_cnt = skb_queue_len(list);
891
892 /* Match msg importance against this and all higher backlog limits: */
893 if (!skb_queue_empty(backlogq)) {
894 for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
895 if (unlikely(l->backlog[i].len >= l->backlog[i].limit))
896 return link_schedule_user(l, list);
897 }
898 }
899 if (unlikely(msg_size(hdr) > mtu)) {
900 skb_queue_purge(list);
901 return -EMSGSIZE;
902 }
903
904 if (pkt_cnt > 1) {
905 l->stats.sent_fragmented++;
906 l->stats.sent_fragments += pkt_cnt;
907 }
908
909 /* Prepare each packet for sending, and add to relevant queue: */
910 while (skb_queue_len(list)) {
911 skb = skb_peek(list);
912 hdr = buf_msg(skb);
913 msg_set_seqno(hdr, seqno);
914 msg_set_ack(hdr, ack);
915 msg_set_bcast_ack(hdr, bc_ack);
916
917 if (likely(skb_queue_len(transmq) < maxwin)) {
918 _skb = skb_clone(skb, GFP_ATOMIC);
919 if (!_skb) {
920 skb_queue_purge(list);
921 return -ENOBUFS;
922 }
923 __skb_dequeue(list);
924 __skb_queue_tail(transmq, skb);
925 __skb_queue_tail(xmitq, _skb);
926 TIPC_SKB_CB(skb)->ackers = l->ackers;
927 l->rcv_unacked = 0;
928 l->stats.sent_pkts++;
929 seqno++;
930 continue;
931 }
932 if (tipc_msg_bundle(skb_peek_tail(backlogq), hdr, mtu)) {
933 kfree_skb(__skb_dequeue(list));
934 l->stats.sent_bundled++;
935 continue;
936 }
937 if (tipc_msg_make_bundle(&bskb, hdr, mtu, l->addr)) {
938 kfree_skb(__skb_dequeue(list));
939 __skb_queue_tail(backlogq, bskb);
940 l->backlog[msg_importance(buf_msg(bskb))].len++;
941 l->stats.sent_bundled++;
942 l->stats.sent_bundles++;
943 continue;
944 }
945 l->backlog[imp].len += skb_queue_len(list);
946 skb_queue_splice_tail_init(list, backlogq);
947 }
948 l->snd_nxt = seqno;
949 return 0;
950}
951
952void tipc_link_advance_backlog(struct tipc_link *l, struct sk_buff_head *xmitq)
953{
954 struct sk_buff *skb, *_skb;
955 struct tipc_msg *hdr;
956 u16 seqno = l->snd_nxt;
957 u16 ack = l->rcv_nxt - 1;
958 u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
959
960 while (skb_queue_len(&l->transmq) < l->window) {
961 skb = skb_peek(&l->backlogq);
962 if (!skb)
963 break;
964 _skb = skb_clone(skb, GFP_ATOMIC);
965 if (!_skb)
966 break;
967 __skb_dequeue(&l->backlogq);
968 hdr = buf_msg(skb);
969 l->backlog[msg_importance(hdr)].len--;
970 __skb_queue_tail(&l->transmq, skb);
971 __skb_queue_tail(xmitq, _skb);
972 TIPC_SKB_CB(skb)->ackers = l->ackers;
973 msg_set_seqno(hdr, seqno);
974 msg_set_ack(hdr, ack);
975 msg_set_bcast_ack(hdr, bc_ack);
976 l->rcv_unacked = 0;
977 l->stats.sent_pkts++;
978 seqno++;
979 }
980 l->snd_nxt = seqno;
981}
982
983static void link_retransmit_failure(struct tipc_link *l, struct sk_buff *skb)
984{
985 struct tipc_msg *hdr = buf_msg(skb);
986
987 pr_warn("Retransmission failure on link <%s>\n", l->name);
988 link_print(l, "Resetting link ");
989 pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
990 msg_user(hdr), msg_type(hdr), msg_size(hdr), msg_errcode(hdr));
991 pr_info("sqno %u, prev: %x, src: %x\n",
992 msg_seqno(hdr), msg_prevnode(hdr), msg_orignode(hdr));
993}
994
995int tipc_link_retrans(struct tipc_link *l, u16 from, u16 to,
996 struct sk_buff_head *xmitq)
997{
998 struct sk_buff *_skb, *skb = skb_peek(&l->transmq);
999 struct tipc_msg *hdr;
1000 u16 ack = l->rcv_nxt - 1;
1001 u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
1002
1003 if (!skb)
1004 return 0;
1005
1006 /* Detect repeated retransmit failures on same packet */
1007 if (likely(l->last_retransm != buf_seqno(skb))) {
1008 l->last_retransm = buf_seqno(skb);
1009 l->stale_count = 1;
1010 } else if (++l->stale_count > 100) {
1011 link_retransmit_failure(l, skb);
1012 return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1013 }
1014
1015 /* Move forward to where retransmission should start */
1016 skb_queue_walk(&l->transmq, skb) {
1017 if (!less(buf_seqno(skb), from))
1018 break;
1019 }
1020
1021 skb_queue_walk_from(&l->transmq, skb) {
1022 if (more(buf_seqno(skb), to))
1023 break;
1024 hdr = buf_msg(skb);
1025 _skb = __pskb_copy(skb, MIN_H_SIZE, GFP_ATOMIC);
1026 if (!_skb)
1027 return 0;
1028 hdr = buf_msg(_skb);
1029 msg_set_ack(hdr, ack);
1030 msg_set_bcast_ack(hdr, bc_ack);
1031 _skb->priority = TC_PRIO_CONTROL;
1032 __skb_queue_tail(xmitq, _skb);
1033 l->stats.retransmitted++;
1034 }
1035 return 0;
1036}
1037
1038/* tipc_data_input - deliver data and name distr msgs to upper layer
1039 *
1040 * Consumes buffer if message is of right type
1041 * Node lock must be held
1042 */
1043static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb,
1044 struct sk_buff_head *inputq)
1045{
1046 switch (msg_user(buf_msg(skb))) {
1047 case TIPC_LOW_IMPORTANCE:
1048 case TIPC_MEDIUM_IMPORTANCE:
1049 case TIPC_HIGH_IMPORTANCE:
1050 case TIPC_CRITICAL_IMPORTANCE:
1051 case CONN_MANAGER:
1052 skb_queue_tail(inputq, skb);
1053 return true;
1054 case NAME_DISTRIBUTOR:
1055 l->bc_rcvlink->state = LINK_ESTABLISHED;
1056 skb_queue_tail(l->namedq, skb);
1057 return true;
1058 case MSG_BUNDLER:
1059 case TUNNEL_PROTOCOL:
1060 case MSG_FRAGMENTER:
1061 case BCAST_PROTOCOL:
1062 return false;
1063 default:
1064 pr_warn("Dropping received illegal msg type\n");
1065 kfree_skb(skb);
1066 return false;
1067 };
1068}
1069
1070/* tipc_link_input - process packet that has passed link protocol check
1071 *
1072 * Consumes buffer
1073 */
1074static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb,
1075 struct sk_buff_head *inputq)
1076{
1077 struct tipc_msg *hdr = buf_msg(skb);
1078 struct sk_buff **reasm_skb = &l->reasm_buf;
1079 struct sk_buff *iskb;
1080 struct sk_buff_head tmpq;
1081 int usr = msg_user(hdr);
1082 int rc = 0;
1083 int pos = 0;
1084 int ipos = 0;
1085
1086 if (unlikely(usr == TUNNEL_PROTOCOL)) {
1087 if (msg_type(hdr) == SYNCH_MSG) {
1088 __skb_queue_purge(&l->deferdq);
1089 goto drop;
1090 }
1091 if (!tipc_msg_extract(skb, &iskb, &ipos))
1092 return rc;
1093 kfree_skb(skb);
1094 skb = iskb;
1095 hdr = buf_msg(skb);
1096 if (less(msg_seqno(hdr), l->drop_point))
1097 goto drop;
1098 if (tipc_data_input(l, skb, inputq))
1099 return rc;
1100 usr = msg_user(hdr);
1101 reasm_skb = &l->failover_reasm_skb;
1102 }
1103
1104 if (usr == MSG_BUNDLER) {
1105 skb_queue_head_init(&tmpq);
1106 l->stats.recv_bundles++;
1107 l->stats.recv_bundled += msg_msgcnt(hdr);
1108 while (tipc_msg_extract(skb, &iskb, &pos))
1109 tipc_data_input(l, iskb, &tmpq);
1110 tipc_skb_queue_splice_tail(&tmpq, inputq);
1111 return 0;
1112 } else if (usr == MSG_FRAGMENTER) {
1113 l->stats.recv_fragments++;
1114 if (tipc_buf_append(reasm_skb, &skb)) {
1115 l->stats.recv_fragmented++;
1116 tipc_data_input(l, skb, inputq);
1117 } else if (!*reasm_skb && !link_is_bc_rcvlink(l)) {
1118 pr_warn_ratelimited("Unable to build fragment list\n");
1119 return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1120 }
1121 return 0;
1122 } else if (usr == BCAST_PROTOCOL) {
1123 tipc_bcast_lock(l->net);
1124 tipc_link_bc_init_rcv(l->bc_rcvlink, hdr);
1125 tipc_bcast_unlock(l->net);
1126 }
1127drop:
1128 kfree_skb(skb);
1129 return 0;
1130}
1131
1132static bool tipc_link_release_pkts(struct tipc_link *l, u16 acked)
1133{
1134 bool released = false;
1135 struct sk_buff *skb, *tmp;
1136
1137 skb_queue_walk_safe(&l->transmq, skb, tmp) {
1138 if (more(buf_seqno(skb), acked))
1139 break;
1140 __skb_unlink(skb, &l->transmq);
1141 kfree_skb(skb);
1142 released = true;
1143 }
1144 return released;
1145}
1146
1147/* tipc_link_build_state_msg: prepare link state message for transmission
1148 *
1149 * Note that sending of broadcast ack is coordinated among nodes, to reduce
1150 * risk of ack storms towards the sender
1151 */
1152int tipc_link_build_state_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1153{
1154 if (!l)
1155 return 0;
1156
1157 /* Broadcast ACK must be sent via a unicast link => defer to caller */
1158 if (link_is_bc_rcvlink(l)) {
1159 if (((l->rcv_nxt ^ tipc_own_addr(l->net)) & 0xf) != 0xf)
1160 return 0;
1161 l->rcv_unacked = 0;
1162
1163 /* Use snd_nxt to store peer's snd_nxt in broadcast rcv link */
1164 l->snd_nxt = l->rcv_nxt;
1165 return TIPC_LINK_SND_STATE;
1166 }
1167
1168 /* Unicast ACK */
1169 l->rcv_unacked = 0;
1170 l->stats.sent_acks++;
1171 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
1172 return 0;
1173}
1174
1175/* tipc_link_build_reset_msg: prepare link RESET or ACTIVATE message
1176 */
1177void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1178{
1179 int mtyp = RESET_MSG;
1180 struct sk_buff *skb;
1181
1182 if (l->state == LINK_ESTABLISHING)
1183 mtyp = ACTIVATE_MSG;
1184
1185 tipc_link_build_proto_msg(l, mtyp, 0, 0, 0, 0, xmitq);
1186
1187 /* Inform peer that this endpoint is going down if applicable */
1188 skb = skb_peek_tail(xmitq);
1189 if (skb && (l->state == LINK_RESET))
1190 msg_set_peer_stopping(buf_msg(skb), 1);
1191}
1192
1193/* tipc_link_build_nack_msg: prepare link nack message for transmission
1194 * Note that sending of broadcast NACK is coordinated among nodes, to
1195 * reduce the risk of NACK storms towards the sender
1196 */
1197static int tipc_link_build_nack_msg(struct tipc_link *l,
1198 struct sk_buff_head *xmitq)
1199{
1200 u32 def_cnt = ++l->stats.deferred_recv;
1201 int match1, match2;
1202
1203 if (link_is_bc_rcvlink(l)) {
1204 match1 = def_cnt & 0xf;
1205 match2 = tipc_own_addr(l->net) & 0xf;
1206 if (match1 == match2)
1207 return TIPC_LINK_SND_STATE;
1208 return 0;
1209 }
1210
1211 if ((skb_queue_len(&l->deferdq) == 1) || !(def_cnt % TIPC_NACK_INTV))
1212 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
1213 return 0;
1214}
1215
1216/* tipc_link_rcv - process TIPC packets/messages arriving from off-node
1217 * @l: the link that should handle the message
1218 * @skb: TIPC packet
1219 * @xmitq: queue to place packets to be sent after this call
1220 */
1221int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
1222 struct sk_buff_head *xmitq)
1223{
1224 struct sk_buff_head *defq = &l->deferdq;
1225 struct tipc_msg *hdr;
1226 u16 seqno, rcv_nxt, win_lim;
1227 int rc = 0;
1228
1229 do {
1230 hdr = buf_msg(skb);
1231 seqno = msg_seqno(hdr);
1232 rcv_nxt = l->rcv_nxt;
1233 win_lim = rcv_nxt + TIPC_MAX_LINK_WIN;
1234
1235 /* Verify and update link state */
1236 if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
1237 return tipc_link_proto_rcv(l, skb, xmitq);
1238
1239 if (unlikely(!link_is_up(l))) {
1240 if (l->state == LINK_ESTABLISHING)
1241 rc = TIPC_LINK_UP_EVT;
1242 goto drop;
1243 }
1244
1245 /* Don't send probe at next timeout expiration */
1246 l->silent_intv_cnt = 0;
1247
1248 /* Drop if outside receive window */
1249 if (unlikely(less(seqno, rcv_nxt) || more(seqno, win_lim))) {
1250 l->stats.duplicates++;
1251 goto drop;
1252 }
1253
1254 /* Forward queues and wake up waiting users */
1255 if (likely(tipc_link_release_pkts(l, msg_ack(hdr)))) {
1256 tipc_link_advance_backlog(l, xmitq);
1257 if (unlikely(!skb_queue_empty(&l->wakeupq)))
1258 link_prepare_wakeup(l);
1259 }
1260
1261 /* Defer delivery if sequence gap */
1262 if (unlikely(seqno != rcv_nxt)) {
1263 __tipc_skb_queue_sorted(defq, seqno, skb);
1264 rc |= tipc_link_build_nack_msg(l, xmitq);
1265 break;
1266 }
1267
1268 /* Deliver packet */
1269 l->rcv_nxt++;
1270 l->stats.recv_pkts++;
1271 if (!tipc_data_input(l, skb, l->inputq))
1272 rc |= tipc_link_input(l, skb, l->inputq);
1273 if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
1274 rc |= tipc_link_build_state_msg(l, xmitq);
1275 if (unlikely(rc & ~TIPC_LINK_SND_STATE))
1276 break;
1277 } while ((skb = __skb_dequeue(defq)));
1278
1279 return rc;
1280drop:
1281 kfree_skb(skb);
1282 return rc;
1283}
1284
1285static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
1286 u16 rcvgap, int tolerance, int priority,
1287 struct sk_buff_head *xmitq)
1288{
1289 struct tipc_link *bcl = l->bc_rcvlink;
1290 struct sk_buff *skb;
1291 struct tipc_msg *hdr;
1292 struct sk_buff_head *dfq = &l->deferdq;
1293 bool node_up = link_is_up(bcl);
1294 struct tipc_mon_state *mstate = &l->mon_state;
1295 int dlen = 0;
1296 void *data;
1297
1298 /* Don't send protocol message during reset or link failover */
1299 if (tipc_link_is_blocked(l))
1300 return;
1301
1302 if (!tipc_link_is_up(l) && (mtyp == STATE_MSG))
1303 return;
1304
1305 if (!skb_queue_empty(dfq))
1306 rcvgap = buf_seqno(skb_peek(dfq)) - l->rcv_nxt;
1307
1308 skb = tipc_msg_create(LINK_PROTOCOL, mtyp, INT_H_SIZE,
1309 tipc_max_domain_size, l->addr,
1310 tipc_own_addr(l->net), 0, 0, 0);
1311 if (!skb)
1312 return;
1313
1314 hdr = buf_msg(skb);
1315 data = msg_data(hdr);
1316 msg_set_session(hdr, l->session);
1317 msg_set_bearer_id(hdr, l->bearer_id);
1318 msg_set_net_plane(hdr, l->net_plane);
1319 msg_set_next_sent(hdr, l->snd_nxt);
1320 msg_set_ack(hdr, l->rcv_nxt - 1);
1321 msg_set_bcast_ack(hdr, bcl->rcv_nxt - 1);
1322 msg_set_bc_ack_invalid(hdr, !node_up);
1323 msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
1324 msg_set_link_tolerance(hdr, tolerance);
1325 msg_set_linkprio(hdr, priority);
1326 msg_set_redundant_link(hdr, node_up);
1327 msg_set_seq_gap(hdr, 0);
1328 msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2);
1329
1330 if (mtyp == STATE_MSG) {
1331 msg_set_seq_gap(hdr, rcvgap);
1332 msg_set_bc_gap(hdr, link_bc_rcv_gap(bcl));
1333 msg_set_probe(hdr, probe);
1334 tipc_mon_prep(l->net, data, &dlen, mstate, l->bearer_id);
1335 msg_set_size(hdr, INT_H_SIZE + dlen);
1336 skb_trim(skb, INT_H_SIZE + dlen);
1337 l->stats.sent_states++;
1338 l->rcv_unacked = 0;
1339 } else {
1340 /* RESET_MSG or ACTIVATE_MSG */
1341 msg_set_max_pkt(hdr, l->advertised_mtu);
1342 strcpy(data, l->if_name);
1343 msg_set_size(hdr, INT_H_SIZE + TIPC_MAX_IF_NAME);
1344 skb_trim(skb, INT_H_SIZE + TIPC_MAX_IF_NAME);
1345 }
1346 if (probe)
1347 l->stats.sent_probes++;
1348 if (rcvgap)
1349 l->stats.sent_nacks++;
1350 skb->priority = TC_PRIO_CONTROL;
1351 __skb_queue_tail(xmitq, skb);
1352}
1353
1354/* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets
1355 * with contents of the link's transmit and backlog queues.
1356 */
1357void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
1358 int mtyp, struct sk_buff_head *xmitq)
1359{
1360 struct sk_buff *skb, *tnlskb;
1361 struct tipc_msg *hdr, tnlhdr;
1362 struct sk_buff_head *queue = &l->transmq;
1363 struct sk_buff_head tmpxq, tnlq;
1364 u16 pktlen, pktcnt, seqno = l->snd_nxt;
1365
1366 if (!tnl)
1367 return;
1368
1369 skb_queue_head_init(&tnlq);
1370 skb_queue_head_init(&tmpxq);
1371
1372 /* At least one packet required for safe algorithm => add dummy */
1373 skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
1374 BASIC_H_SIZE, 0, l->addr, tipc_own_addr(l->net),
1375 0, 0, TIPC_ERR_NO_PORT);
1376 if (!skb) {
1377 pr_warn("%sunable to create tunnel packet\n", link_co_err);
1378 return;
1379 }
1380 skb_queue_tail(&tnlq, skb);
1381 tipc_link_xmit(l, &tnlq, &tmpxq);
1382 __skb_queue_purge(&tmpxq);
1383
1384 /* Initialize reusable tunnel packet header */
1385 tipc_msg_init(tipc_own_addr(l->net), &tnlhdr, TUNNEL_PROTOCOL,
1386 mtyp, INT_H_SIZE, l->addr);
1387 pktcnt = skb_queue_len(&l->transmq) + skb_queue_len(&l->backlogq);
1388 msg_set_msgcnt(&tnlhdr, pktcnt);
1389 msg_set_bearer_id(&tnlhdr, l->peer_bearer_id);
1390tnl:
1391 /* Wrap each packet into a tunnel packet */
1392 skb_queue_walk(queue, skb) {
1393 hdr = buf_msg(skb);
1394 if (queue == &l->backlogq)
1395 msg_set_seqno(hdr, seqno++);
1396 pktlen = msg_size(hdr);
1397 msg_set_size(&tnlhdr, pktlen + INT_H_SIZE);
1398 tnlskb = tipc_buf_acquire(pktlen + INT_H_SIZE, GFP_ATOMIC);
1399 if (!tnlskb) {
1400 pr_warn("%sunable to send packet\n", link_co_err);
1401 return;
1402 }
1403 skb_copy_to_linear_data(tnlskb, &tnlhdr, INT_H_SIZE);
1404 skb_copy_to_linear_data_offset(tnlskb, INT_H_SIZE, hdr, pktlen);
1405 __skb_queue_tail(&tnlq, tnlskb);
1406 }
1407 if (queue != &l->backlogq) {
1408 queue = &l->backlogq;
1409 goto tnl;
1410 }
1411
1412 tipc_link_xmit(tnl, &tnlq, xmitq);
1413
1414 if (mtyp == FAILOVER_MSG) {
1415 tnl->drop_point = l->rcv_nxt;
1416 tnl->failover_reasm_skb = l->reasm_buf;
1417 l->reasm_buf = NULL;
1418 }
1419}
1420
1421/* tipc_link_proto_rcv(): receive link level protocol message :
1422 * Note that network plane id propagates through the network, and may
1423 * change at any time. The node with lowest numerical id determines
1424 * network plane
1425 */
1426static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
1427 struct sk_buff_head *xmitq)
1428{
1429 struct tipc_msg *hdr = buf_msg(skb);
1430 u16 rcvgap = 0;
1431 u16 ack = msg_ack(hdr);
1432 u16 gap = msg_seq_gap(hdr);
1433 u16 peers_snd_nxt = msg_next_sent(hdr);
1434 u16 peers_tol = msg_link_tolerance(hdr);
1435 u16 peers_prio = msg_linkprio(hdr);
1436 u16 rcv_nxt = l->rcv_nxt;
1437 u16 dlen = msg_data_sz(hdr);
1438 int mtyp = msg_type(hdr);
1439 void *data;
1440 char *if_name;
1441 int rc = 0;
1442
1443 if (tipc_link_is_blocked(l) || !xmitq)
1444 goto exit;
1445
1446 if (tipc_own_addr(l->net) > msg_prevnode(hdr))
1447 l->net_plane = msg_net_plane(hdr);
1448
1449 skb_linearize(skb);
1450 hdr = buf_msg(skb);
1451 data = msg_data(hdr);
1452
1453 switch (mtyp) {
1454 case RESET_MSG:
1455
1456 /* Ignore duplicate RESET with old session number */
1457 if ((less_eq(msg_session(hdr), l->peer_session)) &&
1458 (l->peer_session != ANY_SESSION))
1459 break;
1460 /* fall thru' */
1461
1462 case ACTIVATE_MSG:
1463
1464 /* Complete own link name with peer's interface name */
1465 if_name = strrchr(l->name, ':') + 1;
1466 if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME)
1467 break;
1468 if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME)
1469 break;
1470 strncpy(if_name, data, TIPC_MAX_IF_NAME);
1471
1472 /* Update own tolerance if peer indicates a non-zero value */
1473 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1474 l->tolerance = peers_tol;
1475
1476 /* Update own priority if peer's priority is higher */
1477 if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
1478 l->priority = peers_prio;
1479
1480 /* ACTIVATE_MSG serves as PEER_RESET if link is already down */
1481 if (msg_peer_stopping(hdr))
1482 rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1483 else if ((mtyp == RESET_MSG) || !link_is_up(l))
1484 rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
1485
1486 /* ACTIVATE_MSG takes up link if it was already locally reset */
1487 if ((mtyp == ACTIVATE_MSG) && (l->state == LINK_ESTABLISHING))
1488 rc = TIPC_LINK_UP_EVT;
1489
1490 l->peer_session = msg_session(hdr);
1491 l->peer_bearer_id = msg_bearer_id(hdr);
1492 if (l->mtu > msg_max_pkt(hdr))
1493 l->mtu = msg_max_pkt(hdr);
1494 break;
1495
1496 case STATE_MSG:
1497
1498 /* Update own tolerance if peer indicates a non-zero value */
1499 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1500 l->tolerance = peers_tol;
1501
1502 /* Update own prio if peer indicates a different value */
1503 if ((peers_prio != l->priority) &&
1504 in_range(peers_prio, 1, TIPC_MAX_LINK_PRI)) {
1505 l->priority = peers_prio;
1506 rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1507 }
1508
1509 l->silent_intv_cnt = 0;
1510 l->stats.recv_states++;
1511 if (msg_probe(hdr))
1512 l->stats.recv_probes++;
1513
1514 if (!link_is_up(l)) {
1515 if (l->state == LINK_ESTABLISHING)
1516 rc = TIPC_LINK_UP_EVT;
1517 break;
1518 }
1519 tipc_mon_rcv(l->net, data, dlen, l->addr,
1520 &l->mon_state, l->bearer_id);
1521
1522 /* Send NACK if peer has sent pkts we haven't received yet */
1523 if (more(peers_snd_nxt, rcv_nxt) && !tipc_link_is_synching(l))
1524 rcvgap = peers_snd_nxt - l->rcv_nxt;
1525 if (rcvgap || (msg_probe(hdr)))
1526 tipc_link_build_proto_msg(l, STATE_MSG, 0, rcvgap,
1527 0, 0, xmitq);
1528 tipc_link_release_pkts(l, ack);
1529
1530 /* If NACK, retransmit will now start at right position */
1531 if (gap) {
1532 rc = tipc_link_retrans(l, ack + 1, ack + gap, xmitq);
1533 l->stats.recv_nacks++;
1534 }
1535
1536 tipc_link_advance_backlog(l, xmitq);
1537 if (unlikely(!skb_queue_empty(&l->wakeupq)))
1538 link_prepare_wakeup(l);
1539 }
1540exit:
1541 kfree_skb(skb);
1542 return rc;
1543}
1544
1545/* tipc_link_build_bc_proto_msg() - create broadcast protocol message
1546 */
1547static bool tipc_link_build_bc_proto_msg(struct tipc_link *l, bool bcast,
1548 u16 peers_snd_nxt,
1549 struct sk_buff_head *xmitq)
1550{
1551 struct sk_buff *skb;
1552 struct tipc_msg *hdr;
1553 struct sk_buff *dfrd_skb = skb_peek(&l->deferdq);
1554 u16 ack = l->rcv_nxt - 1;
1555 u16 gap_to = peers_snd_nxt - 1;
1556
1557 skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
1558 0, l->addr, tipc_own_addr(l->net), 0, 0, 0);
1559 if (!skb)
1560 return false;
1561 hdr = buf_msg(skb);
1562 msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
1563 msg_set_bcast_ack(hdr, ack);
1564 msg_set_bcgap_after(hdr, ack);
1565 if (dfrd_skb)
1566 gap_to = buf_seqno(dfrd_skb) - 1;
1567 msg_set_bcgap_to(hdr, gap_to);
1568 msg_set_non_seq(hdr, bcast);
1569 __skb_queue_tail(xmitq, skb);
1570 return true;
1571}
1572
1573/* tipc_link_build_bc_init_msg() - synchronize broadcast link endpoints.
1574 *
1575 * Give a newly added peer node the sequence number where it should
1576 * start receiving and acking broadcast packets.
1577 */
1578static void tipc_link_build_bc_init_msg(struct tipc_link *l,
1579 struct sk_buff_head *xmitq)
1580{
1581 struct sk_buff_head list;
1582
1583 __skb_queue_head_init(&list);
1584 if (!tipc_link_build_bc_proto_msg(l->bc_rcvlink, false, 0, &list))
1585 return;
1586 msg_set_bc_ack_invalid(buf_msg(skb_peek(&list)), true);
1587 tipc_link_xmit(l, &list, xmitq);
1588}
1589
1590/* tipc_link_bc_init_rcv - receive initial broadcast synch data from peer
1591 */
1592void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr)
1593{
1594 int mtyp = msg_type(hdr);
1595 u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
1596
1597 if (link_is_up(l))
1598 return;
1599
1600 if (msg_user(hdr) == BCAST_PROTOCOL) {
1601 l->rcv_nxt = peers_snd_nxt;
1602 l->state = LINK_ESTABLISHED;
1603 return;
1604 }
1605
1606 if (l->peer_caps & TIPC_BCAST_SYNCH)
1607 return;
1608
1609 if (msg_peer_node_is_up(hdr))
1610 return;
1611
1612 /* Compatibility: accept older, less safe initial synch data */
1613 if ((mtyp == RESET_MSG) || (mtyp == ACTIVATE_MSG))
1614 l->rcv_nxt = peers_snd_nxt;
1615}
1616
1617/* link_bc_retr eval()- check if the indicated range can be retransmitted now
1618 * - Adjust permitted range if there is overlap with previous retransmission
1619 */
1620static bool link_bc_retr_eval(struct tipc_link *l, u16 *from, u16 *to)
1621{
1622 unsigned long elapsed = jiffies_to_msecs(jiffies - l->prev_retr);
1623
1624 if (less(*to, *from))
1625 return false;
1626
1627 /* New retransmission request */
1628 if ((elapsed > TIPC_BC_RETR_LIMIT) ||
1629 less(*to, l->prev_from) || more(*from, l->prev_to)) {
1630 l->prev_from = *from;
1631 l->prev_to = *to;
1632 l->prev_retr = jiffies;
1633 return true;
1634 }
1635
1636 /* Inside range of previous retransmit */
1637 if (!less(*from, l->prev_from) && !more(*to, l->prev_to))
1638 return false;
1639
1640 /* Fully or partially outside previous range => exclude overlap */
1641 if (less(*from, l->prev_from)) {
1642 *to = l->prev_from - 1;
1643 l->prev_from = *from;
1644 }
1645 if (more(*to, l->prev_to)) {
1646 *from = l->prev_to + 1;
1647 l->prev_to = *to;
1648 }
1649 l->prev_retr = jiffies;
1650 return true;
1651}
1652
1653/* tipc_link_bc_sync_rcv - update rcv link according to peer's send state
1654 */
1655int tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
1656 struct sk_buff_head *xmitq)
1657{
1658 struct tipc_link *snd_l = l->bc_sndlink;
1659 u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
1660 u16 from = msg_bcast_ack(hdr) + 1;
1661 u16 to = from + msg_bc_gap(hdr) - 1;
1662 int rc = 0;
1663
1664 if (!link_is_up(l))
1665 return rc;
1666
1667 if (!msg_peer_node_is_up(hdr))
1668 return rc;
1669
1670 /* Open when peer ackowledges our bcast init msg (pkt #1) */
1671 if (msg_ack(hdr))
1672 l->bc_peer_is_up = true;
1673
1674 if (!l->bc_peer_is_up)
1675 return rc;
1676
1677 l->stats.recv_nacks++;
1678
1679 /* Ignore if peers_snd_nxt goes beyond receive window */
1680 if (more(peers_snd_nxt, l->rcv_nxt + l->window))
1681 return rc;
1682
1683 if (link_bc_retr_eval(snd_l, &from, &to))
1684 rc = tipc_link_retrans(snd_l, from, to, xmitq);
1685
1686 l->snd_nxt = peers_snd_nxt;
1687 if (link_bc_rcv_gap(l))
1688 rc |= TIPC_LINK_SND_STATE;
1689
1690 /* Return now if sender supports nack via STATE messages */
1691 if (l->peer_caps & TIPC_BCAST_STATE_NACK)
1692 return rc;
1693
1694 /* Otherwise, be backwards compatible */
1695
1696 if (!more(peers_snd_nxt, l->rcv_nxt)) {
1697 l->nack_state = BC_NACK_SND_CONDITIONAL;
1698 return 0;
1699 }
1700
1701 /* Don't NACK if one was recently sent or peeked */
1702 if (l->nack_state == BC_NACK_SND_SUPPRESS) {
1703 l->nack_state = BC_NACK_SND_UNCONDITIONAL;
1704 return 0;
1705 }
1706
1707 /* Conditionally delay NACK sending until next synch rcv */
1708 if (l->nack_state == BC_NACK_SND_CONDITIONAL) {
1709 l->nack_state = BC_NACK_SND_UNCONDITIONAL;
1710 if ((peers_snd_nxt - l->rcv_nxt) < TIPC_MIN_LINK_WIN)
1711 return 0;
1712 }
1713
1714 /* Send NACK now but suppress next one */
1715 tipc_link_build_bc_proto_msg(l, true, peers_snd_nxt, xmitq);
1716 l->nack_state = BC_NACK_SND_SUPPRESS;
1717 return 0;
1718}
1719
1720void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
1721 struct sk_buff_head *xmitq)
1722{
1723 struct sk_buff *skb, *tmp;
1724 struct tipc_link *snd_l = l->bc_sndlink;
1725
1726 if (!link_is_up(l) || !l->bc_peer_is_up)
1727 return;
1728
1729 if (!more(acked, l->acked))
1730 return;
1731
1732 /* Skip over packets peer has already acked */
1733 skb_queue_walk(&snd_l->transmq, skb) {
1734 if (more(buf_seqno(skb), l->acked))
1735 break;
1736 }
1737
1738 /* Update/release the packets peer is acking now */
1739 skb_queue_walk_from_safe(&snd_l->transmq, skb, tmp) {
1740 if (more(buf_seqno(skb), acked))
1741 break;
1742 if (!--TIPC_SKB_CB(skb)->ackers) {
1743 __skb_unlink(skb, &snd_l->transmq);
1744 kfree_skb(skb);
1745 }
1746 }
1747 l->acked = acked;
1748 tipc_link_advance_backlog(snd_l, xmitq);
1749 if (unlikely(!skb_queue_empty(&snd_l->wakeupq)))
1750 link_prepare_wakeup(snd_l);
1751}
1752
1753/* tipc_link_bc_nack_rcv(): receive broadcast nack message
1754 * This function is here for backwards compatibility, since
1755 * no BCAST_PROTOCOL/STATE messages occur from TIPC v2.5.
1756 */
1757int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
1758 struct sk_buff_head *xmitq)
1759{
1760 struct tipc_msg *hdr = buf_msg(skb);
1761 u32 dnode = msg_destnode(hdr);
1762 int mtyp = msg_type(hdr);
1763 u16 acked = msg_bcast_ack(hdr);
1764 u16 from = acked + 1;
1765 u16 to = msg_bcgap_to(hdr);
1766 u16 peers_snd_nxt = to + 1;
1767 int rc = 0;
1768
1769 kfree_skb(skb);
1770
1771 if (!tipc_link_is_up(l) || !l->bc_peer_is_up)
1772 return 0;
1773
1774 if (mtyp != STATE_MSG)
1775 return 0;
1776
1777 if (dnode == tipc_own_addr(l->net)) {
1778 tipc_link_bc_ack_rcv(l, acked, xmitq);
1779 rc = tipc_link_retrans(l->bc_sndlink, from, to, xmitq);
1780 l->stats.recv_nacks++;
1781 return rc;
1782 }
1783
1784 /* Msg for other node => suppress own NACK at next sync if applicable */
1785 if (more(peers_snd_nxt, l->rcv_nxt) && !less(l->rcv_nxt, from))
1786 l->nack_state = BC_NACK_SND_SUPPRESS;
1787
1788 return 0;
1789}
1790
1791void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
1792{
1793 int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE);
1794
1795 l->window = win;
1796 l->backlog[TIPC_LOW_IMPORTANCE].limit = max_t(u16, 50, win);
1797 l->backlog[TIPC_MEDIUM_IMPORTANCE].limit = max_t(u16, 100, win * 2);
1798 l->backlog[TIPC_HIGH_IMPORTANCE].limit = max_t(u16, 150, win * 3);
1799 l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = max_t(u16, 200, win * 4);
1800 l->backlog[TIPC_SYSTEM_IMPORTANCE].limit = max_bulk;
1801}
1802
1803/**
1804 * link_reset_stats - reset link statistics
1805 * @l: pointer to link
1806 */
1807void tipc_link_reset_stats(struct tipc_link *l)
1808{
1809 memset(&l->stats, 0, sizeof(l->stats));
1810}
1811
1812static void link_print(struct tipc_link *l, const char *str)
1813{
1814 struct sk_buff *hskb = skb_peek(&l->transmq);
1815 u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt - 1;
1816 u16 tail = l->snd_nxt - 1;
1817
1818 pr_info("%s Link <%s> state %x\n", str, l->name, l->state);
1819 pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n",
1820 skb_queue_len(&l->transmq), head, tail,
1821 skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt);
1822}
1823
1824/* Parse and validate nested (link) properties valid for media, bearer and link
1825 */
1826int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
1827{
1828 int err;
1829
1830 err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop,
1831 tipc_nl_prop_policy);
1832 if (err)
1833 return err;
1834
1835 if (props[TIPC_NLA_PROP_PRIO]) {
1836 u32 prio;
1837
1838 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1839 if (prio > TIPC_MAX_LINK_PRI)
1840 return -EINVAL;
1841 }
1842
1843 if (props[TIPC_NLA_PROP_TOL]) {
1844 u32 tol;
1845
1846 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1847 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1848 return -EINVAL;
1849 }
1850
1851 if (props[TIPC_NLA_PROP_WIN]) {
1852 u32 win;
1853
1854 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1855 if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
1856 return -EINVAL;
1857 }
1858
1859 return 0;
1860}
1861
1862static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
1863{
1864 int i;
1865 struct nlattr *stats;
1866
1867 struct nla_map {
1868 u32 key;
1869 u32 val;
1870 };
1871
1872 struct nla_map map[] = {
1873 {TIPC_NLA_STATS_RX_INFO, 0},
1874 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
1875 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
1876 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
1877 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
1878 {TIPC_NLA_STATS_TX_INFO, 0},
1879 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
1880 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
1881 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
1882 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
1883 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
1884 s->msg_length_counts : 1},
1885 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
1886 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
1887 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
1888 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
1889 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
1890 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
1891 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
1892 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
1893 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
1894 {TIPC_NLA_STATS_RX_STATES, s->recv_states},
1895 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
1896 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
1897 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
1898 {TIPC_NLA_STATS_TX_STATES, s->sent_states},
1899 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
1900 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
1901 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
1902 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
1903 {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
1904 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
1905 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
1906 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
1907 (s->accu_queue_sz / s->queue_sz_counts) : 0}
1908 };
1909
1910 stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
1911 if (!stats)
1912 return -EMSGSIZE;
1913
1914 for (i = 0; i < ARRAY_SIZE(map); i++)
1915 if (nla_put_u32(skb, map[i].key, map[i].val))
1916 goto msg_full;
1917
1918 nla_nest_end(skb, stats);
1919
1920 return 0;
1921msg_full:
1922 nla_nest_cancel(skb, stats);
1923
1924 return -EMSGSIZE;
1925}
1926
1927/* Caller should hold appropriate locks to protect the link */
1928int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
1929 struct tipc_link *link, int nlflags)
1930{
1931 int err;
1932 void *hdr;
1933 struct nlattr *attrs;
1934 struct nlattr *prop;
1935 struct tipc_net *tn = net_generic(net, tipc_net_id);
1936
1937 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1938 nlflags, TIPC_NL_LINK_GET);
1939 if (!hdr)
1940 return -EMSGSIZE;
1941
1942 attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
1943 if (!attrs)
1944 goto msg_full;
1945
1946 if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
1947 goto attr_msg_full;
1948 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST,
1949 tipc_cluster_mask(tn->own_addr)))
1950 goto attr_msg_full;
1951 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
1952 goto attr_msg_full;
1953 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->stats.recv_pkts))
1954 goto attr_msg_full;
1955 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->stats.sent_pkts))
1956 goto attr_msg_full;
1957
1958 if (tipc_link_is_up(link))
1959 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
1960 goto attr_msg_full;
1961 if (link->active)
1962 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
1963 goto attr_msg_full;
1964
1965 prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
1966 if (!prop)
1967 goto attr_msg_full;
1968 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
1969 goto prop_msg_full;
1970 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
1971 goto prop_msg_full;
1972 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
1973 link->window))
1974 goto prop_msg_full;
1975 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
1976 goto prop_msg_full;
1977 nla_nest_end(msg->skb, prop);
1978
1979 err = __tipc_nl_add_stats(msg->skb, &link->stats);
1980 if (err)
1981 goto attr_msg_full;
1982
1983 nla_nest_end(msg->skb, attrs);
1984 genlmsg_end(msg->skb, hdr);
1985
1986 return 0;
1987
1988prop_msg_full:
1989 nla_nest_cancel(msg->skb, prop);
1990attr_msg_full:
1991 nla_nest_cancel(msg->skb, attrs);
1992msg_full:
1993 genlmsg_cancel(msg->skb, hdr);
1994
1995 return -EMSGSIZE;
1996}
1997
1998static int __tipc_nl_add_bc_link_stat(struct sk_buff *skb,
1999 struct tipc_stats *stats)
2000{
2001 int i;
2002 struct nlattr *nest;
2003
2004 struct nla_map {
2005 __u32 key;
2006 __u32 val;
2007 };
2008
2009 struct nla_map map[] = {
2010 {TIPC_NLA_STATS_RX_INFO, stats->recv_pkts},
2011 {TIPC_NLA_STATS_RX_FRAGMENTS, stats->recv_fragments},
2012 {TIPC_NLA_STATS_RX_FRAGMENTED, stats->recv_fragmented},
2013 {TIPC_NLA_STATS_RX_BUNDLES, stats->recv_bundles},
2014 {TIPC_NLA_STATS_RX_BUNDLED, stats->recv_bundled},
2015 {TIPC_NLA_STATS_TX_INFO, stats->sent_pkts},
2016 {TIPC_NLA_STATS_TX_FRAGMENTS, stats->sent_fragments},
2017 {TIPC_NLA_STATS_TX_FRAGMENTED, stats->sent_fragmented},
2018 {TIPC_NLA_STATS_TX_BUNDLES, stats->sent_bundles},
2019 {TIPC_NLA_STATS_TX_BUNDLED, stats->sent_bundled},
2020 {TIPC_NLA_STATS_RX_NACKS, stats->recv_nacks},
2021 {TIPC_NLA_STATS_RX_DEFERRED, stats->deferred_recv},
2022 {TIPC_NLA_STATS_TX_NACKS, stats->sent_nacks},
2023 {TIPC_NLA_STATS_TX_ACKS, stats->sent_acks},
2024 {TIPC_NLA_STATS_RETRANSMITTED, stats->retransmitted},
2025 {TIPC_NLA_STATS_DUPLICATES, stats->duplicates},
2026 {TIPC_NLA_STATS_LINK_CONGS, stats->link_congs},
2027 {TIPC_NLA_STATS_MAX_QUEUE, stats->max_queue_sz},
2028 {TIPC_NLA_STATS_AVG_QUEUE, stats->queue_sz_counts ?
2029 (stats->accu_queue_sz / stats->queue_sz_counts) : 0}
2030 };
2031
2032 nest = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
2033 if (!nest)
2034 return -EMSGSIZE;
2035
2036 for (i = 0; i < ARRAY_SIZE(map); i++)
2037 if (nla_put_u32(skb, map[i].key, map[i].val))
2038 goto msg_full;
2039
2040 nla_nest_end(skb, nest);
2041
2042 return 0;
2043msg_full:
2044 nla_nest_cancel(skb, nest);
2045
2046 return -EMSGSIZE;
2047}
2048
2049int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg)
2050{
2051 int err;
2052 void *hdr;
2053 struct nlattr *attrs;
2054 struct nlattr *prop;
2055 struct tipc_net *tn = net_generic(net, tipc_net_id);
2056 struct tipc_link *bcl = tn->bcl;
2057
2058 if (!bcl)
2059 return 0;
2060
2061 tipc_bcast_lock(net);
2062
2063 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2064 NLM_F_MULTI, TIPC_NL_LINK_GET);
2065 if (!hdr) {
2066 tipc_bcast_unlock(net);
2067 return -EMSGSIZE;
2068 }
2069
2070 attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
2071 if (!attrs)
2072 goto msg_full;
2073
2074 /* The broadcast link is always up */
2075 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2076 goto attr_msg_full;
2077
2078 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_BROADCAST))
2079 goto attr_msg_full;
2080 if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, bcl->name))
2081 goto attr_msg_full;
2082 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, 0))
2083 goto attr_msg_full;
2084 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, 0))
2085 goto attr_msg_full;
2086
2087 prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
2088 if (!prop)
2089 goto attr_msg_full;
2090 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bcl->window))
2091 goto prop_msg_full;
2092 nla_nest_end(msg->skb, prop);
2093
2094 err = __tipc_nl_add_bc_link_stat(msg->skb, &bcl->stats);
2095 if (err)
2096 goto attr_msg_full;
2097
2098 tipc_bcast_unlock(net);
2099 nla_nest_end(msg->skb, attrs);
2100 genlmsg_end(msg->skb, hdr);
2101
2102 return 0;
2103
2104prop_msg_full:
2105 nla_nest_cancel(msg->skb, prop);
2106attr_msg_full:
2107 nla_nest_cancel(msg->skb, attrs);
2108msg_full:
2109 tipc_bcast_unlock(net);
2110 genlmsg_cancel(msg->skb, hdr);
2111
2112 return -EMSGSIZE;
2113}
2114
2115void tipc_link_set_tolerance(struct tipc_link *l, u32 tol,
2116 struct sk_buff_head *xmitq)
2117{
2118 l->tolerance = tol;
2119 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, tol, 0, xmitq);
2120}
2121
2122void tipc_link_set_prio(struct tipc_link *l, u32 prio,
2123 struct sk_buff_head *xmitq)
2124{
2125 l->priority = prio;
2126 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, prio, xmitq);
2127}
2128
2129void tipc_link_set_abort_limit(struct tipc_link *l, u32 limit)
2130{
2131 l->abort_limit = limit;
2132}
1/*
2 * net/tipc/link.c: TIPC link code
3 *
4 * Copyright (c) 1996-2007, 2012-2014, 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 "link.h"
39#include "port.h"
40#include "name_distr.h"
41#include "discover.h"
42#include "config.h"
43
44#include <linux/pkt_sched.h>
45
46/*
47 * Error message prefixes
48 */
49static const char *link_co_err = "Link changeover error, ";
50static const char *link_rst_msg = "Resetting link ";
51static const char *link_unk_evt = "Unknown link event ";
52
53/*
54 * Out-of-range value for link session numbers
55 */
56#define INVALID_SESSION 0x10000
57
58/*
59 * Link state events:
60 */
61#define STARTING_EVT 856384768 /* link processing trigger */
62#define TRAFFIC_MSG_EVT 560815u /* rx'd ??? */
63#define TIMEOUT_EVT 560817u /* link timer expired */
64
65/*
66 * The following two 'message types' is really just implementation
67 * data conveniently stored in the message header.
68 * They must not be considered part of the protocol
69 */
70#define OPEN_MSG 0
71#define CLOSED_MSG 1
72
73/*
74 * State value stored in 'exp_msg_count'
75 */
76#define START_CHANGEOVER 100000u
77
78static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
79 struct sk_buff *buf);
80static void tipc_link_proto_rcv(struct tipc_link *l_ptr, struct sk_buff *buf);
81static int tipc_link_tunnel_rcv(struct tipc_node *n_ptr,
82 struct sk_buff **buf);
83static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance);
84static int tipc_link_iovec_long_xmit(struct tipc_port *sender,
85 struct iovec const *msg_sect,
86 unsigned int len, u32 destnode);
87static void link_state_event(struct tipc_link *l_ptr, u32 event);
88static void link_reset_statistics(struct tipc_link *l_ptr);
89static void link_print(struct tipc_link *l_ptr, const char *str);
90static int tipc_link_frag_xmit(struct tipc_link *l_ptr, struct sk_buff *buf);
91static void tipc_link_sync_xmit(struct tipc_link *l);
92static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf);
93
94/*
95 * Simple link routines
96 */
97static unsigned int align(unsigned int i)
98{
99 return (i + 3) & ~3u;
100}
101
102static void link_init_max_pkt(struct tipc_link *l_ptr)
103{
104 u32 max_pkt;
105
106 max_pkt = (l_ptr->b_ptr->mtu & ~3);
107 if (max_pkt > MAX_MSG_SIZE)
108 max_pkt = MAX_MSG_SIZE;
109
110 l_ptr->max_pkt_target = max_pkt;
111 if (l_ptr->max_pkt_target < MAX_PKT_DEFAULT)
112 l_ptr->max_pkt = l_ptr->max_pkt_target;
113 else
114 l_ptr->max_pkt = MAX_PKT_DEFAULT;
115
116 l_ptr->max_pkt_probes = 0;
117}
118
119static u32 link_next_sent(struct tipc_link *l_ptr)
120{
121 if (l_ptr->next_out)
122 return buf_seqno(l_ptr->next_out);
123 return mod(l_ptr->next_out_no);
124}
125
126static u32 link_last_sent(struct tipc_link *l_ptr)
127{
128 return mod(link_next_sent(l_ptr) - 1);
129}
130
131/*
132 * Simple non-static link routines (i.e. referenced outside this file)
133 */
134int tipc_link_is_up(struct tipc_link *l_ptr)
135{
136 if (!l_ptr)
137 return 0;
138 return link_working_working(l_ptr) || link_working_unknown(l_ptr);
139}
140
141int tipc_link_is_active(struct tipc_link *l_ptr)
142{
143 return (l_ptr->owner->active_links[0] == l_ptr) ||
144 (l_ptr->owner->active_links[1] == l_ptr);
145}
146
147/**
148 * link_timeout - handle expiration of link timer
149 * @l_ptr: pointer to link
150 */
151static void link_timeout(struct tipc_link *l_ptr)
152{
153 tipc_node_lock(l_ptr->owner);
154
155 /* update counters used in statistical profiling of send traffic */
156 l_ptr->stats.accu_queue_sz += l_ptr->out_queue_size;
157 l_ptr->stats.queue_sz_counts++;
158
159 if (l_ptr->first_out) {
160 struct tipc_msg *msg = buf_msg(l_ptr->first_out);
161 u32 length = msg_size(msg);
162
163 if ((msg_user(msg) == MSG_FRAGMENTER) &&
164 (msg_type(msg) == FIRST_FRAGMENT)) {
165 length = msg_size(msg_get_wrapped(msg));
166 }
167 if (length) {
168 l_ptr->stats.msg_lengths_total += length;
169 l_ptr->stats.msg_length_counts++;
170 if (length <= 64)
171 l_ptr->stats.msg_length_profile[0]++;
172 else if (length <= 256)
173 l_ptr->stats.msg_length_profile[1]++;
174 else if (length <= 1024)
175 l_ptr->stats.msg_length_profile[2]++;
176 else if (length <= 4096)
177 l_ptr->stats.msg_length_profile[3]++;
178 else if (length <= 16384)
179 l_ptr->stats.msg_length_profile[4]++;
180 else if (length <= 32768)
181 l_ptr->stats.msg_length_profile[5]++;
182 else
183 l_ptr->stats.msg_length_profile[6]++;
184 }
185 }
186
187 /* do all other link processing performed on a periodic basis */
188
189 link_state_event(l_ptr, TIMEOUT_EVT);
190
191 if (l_ptr->next_out)
192 tipc_link_push_queue(l_ptr);
193
194 tipc_node_unlock(l_ptr->owner);
195}
196
197static void link_set_timer(struct tipc_link *l_ptr, u32 time)
198{
199 k_start_timer(&l_ptr->timer, time);
200}
201
202/**
203 * tipc_link_create - create a new link
204 * @n_ptr: pointer to associated node
205 * @b_ptr: pointer to associated bearer
206 * @media_addr: media address to use when sending messages over link
207 *
208 * Returns pointer to link.
209 */
210struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
211 struct tipc_bearer *b_ptr,
212 const struct tipc_media_addr *media_addr)
213{
214 struct tipc_link *l_ptr;
215 struct tipc_msg *msg;
216 char *if_name;
217 char addr_string[16];
218 u32 peer = n_ptr->addr;
219
220 if (n_ptr->link_cnt >= 2) {
221 tipc_addr_string_fill(addr_string, n_ptr->addr);
222 pr_err("Attempt to establish third link to %s\n", addr_string);
223 return NULL;
224 }
225
226 if (n_ptr->links[b_ptr->identity]) {
227 tipc_addr_string_fill(addr_string, n_ptr->addr);
228 pr_err("Attempt to establish second link on <%s> to %s\n",
229 b_ptr->name, addr_string);
230 return NULL;
231 }
232
233 l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
234 if (!l_ptr) {
235 pr_warn("Link creation failed, no memory\n");
236 return NULL;
237 }
238
239 l_ptr->addr = peer;
240 if_name = strchr(b_ptr->name, ':') + 1;
241 sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
242 tipc_zone(tipc_own_addr), tipc_cluster(tipc_own_addr),
243 tipc_node(tipc_own_addr),
244 if_name,
245 tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
246 /* note: peer i/f name is updated by reset/activate message */
247 memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
248 l_ptr->owner = n_ptr;
249 l_ptr->checkpoint = 1;
250 l_ptr->peer_session = INVALID_SESSION;
251 l_ptr->b_ptr = b_ptr;
252 link_set_supervision_props(l_ptr, b_ptr->tolerance);
253 l_ptr->state = RESET_UNKNOWN;
254
255 l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
256 msg = l_ptr->pmsg;
257 tipc_msg_init(msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, l_ptr->addr);
258 msg_set_size(msg, sizeof(l_ptr->proto_msg));
259 msg_set_session(msg, (tipc_random & 0xffff));
260 msg_set_bearer_id(msg, b_ptr->identity);
261 strcpy((char *)msg_data(msg), if_name);
262
263 l_ptr->priority = b_ptr->priority;
264 tipc_link_set_queue_limits(l_ptr, b_ptr->window);
265
266 link_init_max_pkt(l_ptr);
267
268 l_ptr->next_out_no = 1;
269 INIT_LIST_HEAD(&l_ptr->waiting_ports);
270
271 link_reset_statistics(l_ptr);
272
273 tipc_node_attach_link(n_ptr, l_ptr);
274
275 k_init_timer(&l_ptr->timer, (Handler)link_timeout,
276 (unsigned long)l_ptr);
277
278 link_state_event(l_ptr, STARTING_EVT);
279
280 return l_ptr;
281}
282
283void tipc_link_delete_list(unsigned int bearer_id, bool shutting_down)
284{
285 struct tipc_link *l_ptr;
286 struct tipc_node *n_ptr;
287
288 rcu_read_lock();
289 list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
290 spin_lock_bh(&n_ptr->lock);
291 l_ptr = n_ptr->links[bearer_id];
292 if (l_ptr) {
293 tipc_link_reset(l_ptr);
294 if (shutting_down || !tipc_node_is_up(n_ptr)) {
295 tipc_node_detach_link(l_ptr->owner, l_ptr);
296 tipc_link_reset_fragments(l_ptr);
297 spin_unlock_bh(&n_ptr->lock);
298
299 /* Nobody else can access this link now: */
300 del_timer_sync(&l_ptr->timer);
301 kfree(l_ptr);
302 } else {
303 /* Detach/delete when failover is finished: */
304 l_ptr->flags |= LINK_STOPPED;
305 spin_unlock_bh(&n_ptr->lock);
306 del_timer_sync(&l_ptr->timer);
307 }
308 continue;
309 }
310 spin_unlock_bh(&n_ptr->lock);
311 }
312 rcu_read_unlock();
313}
314
315/**
316 * link_schedule_port - schedule port for deferred sending
317 * @l_ptr: pointer to link
318 * @origport: reference to sending port
319 * @sz: amount of data to be sent
320 *
321 * Schedules port for renewed sending of messages after link congestion
322 * has abated.
323 */
324static int link_schedule_port(struct tipc_link *l_ptr, u32 origport, u32 sz)
325{
326 struct tipc_port *p_ptr;
327
328 spin_lock_bh(&tipc_port_list_lock);
329 p_ptr = tipc_port_lock(origport);
330 if (p_ptr) {
331 if (!list_empty(&p_ptr->wait_list))
332 goto exit;
333 p_ptr->congested = 1;
334 p_ptr->waiting_pkts = 1 + ((sz - 1) / l_ptr->max_pkt);
335 list_add_tail(&p_ptr->wait_list, &l_ptr->waiting_ports);
336 l_ptr->stats.link_congs++;
337exit:
338 tipc_port_unlock(p_ptr);
339 }
340 spin_unlock_bh(&tipc_port_list_lock);
341 return -ELINKCONG;
342}
343
344void tipc_link_wakeup_ports(struct tipc_link *l_ptr, int all)
345{
346 struct tipc_port *p_ptr;
347 struct tipc_port *temp_p_ptr;
348 int win = l_ptr->queue_limit[0] - l_ptr->out_queue_size;
349
350 if (all)
351 win = 100000;
352 if (win <= 0)
353 return;
354 if (!spin_trylock_bh(&tipc_port_list_lock))
355 return;
356 if (link_congested(l_ptr))
357 goto exit;
358 list_for_each_entry_safe(p_ptr, temp_p_ptr, &l_ptr->waiting_ports,
359 wait_list) {
360 if (win <= 0)
361 break;
362 list_del_init(&p_ptr->wait_list);
363 spin_lock_bh(p_ptr->lock);
364 p_ptr->congested = 0;
365 tipc_port_wakeup(p_ptr);
366 win -= p_ptr->waiting_pkts;
367 spin_unlock_bh(p_ptr->lock);
368 }
369
370exit:
371 spin_unlock_bh(&tipc_port_list_lock);
372}
373
374/**
375 * link_release_outqueue - purge link's outbound message queue
376 * @l_ptr: pointer to link
377 */
378static void link_release_outqueue(struct tipc_link *l_ptr)
379{
380 kfree_skb_list(l_ptr->first_out);
381 l_ptr->first_out = NULL;
382 l_ptr->out_queue_size = 0;
383}
384
385/**
386 * tipc_link_reset_fragments - purge link's inbound message fragments queue
387 * @l_ptr: pointer to link
388 */
389void tipc_link_reset_fragments(struct tipc_link *l_ptr)
390{
391 kfree_skb(l_ptr->reasm_head);
392 l_ptr->reasm_head = NULL;
393 l_ptr->reasm_tail = NULL;
394}
395
396/**
397 * tipc_link_purge_queues - purge all pkt queues associated with link
398 * @l_ptr: pointer to link
399 */
400void tipc_link_purge_queues(struct tipc_link *l_ptr)
401{
402 kfree_skb_list(l_ptr->oldest_deferred_in);
403 kfree_skb_list(l_ptr->first_out);
404 tipc_link_reset_fragments(l_ptr);
405 kfree_skb(l_ptr->proto_msg_queue);
406 l_ptr->proto_msg_queue = NULL;
407}
408
409void tipc_link_reset(struct tipc_link *l_ptr)
410{
411 u32 prev_state = l_ptr->state;
412 u32 checkpoint = l_ptr->next_in_no;
413 int was_active_link = tipc_link_is_active(l_ptr);
414
415 msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
416
417 /* Link is down, accept any session */
418 l_ptr->peer_session = INVALID_SESSION;
419
420 /* Prepare for max packet size negotiation */
421 link_init_max_pkt(l_ptr);
422
423 l_ptr->state = RESET_UNKNOWN;
424
425 if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
426 return;
427
428 tipc_node_link_down(l_ptr->owner, l_ptr);
429 tipc_bearer_remove_dest(l_ptr->b_ptr, l_ptr->addr);
430
431 if (was_active_link && tipc_node_active_links(l_ptr->owner)) {
432 l_ptr->reset_checkpoint = checkpoint;
433 l_ptr->exp_msg_count = START_CHANGEOVER;
434 }
435
436 /* Clean up all queues: */
437 link_release_outqueue(l_ptr);
438 kfree_skb(l_ptr->proto_msg_queue);
439 l_ptr->proto_msg_queue = NULL;
440 kfree_skb_list(l_ptr->oldest_deferred_in);
441 if (!list_empty(&l_ptr->waiting_ports))
442 tipc_link_wakeup_ports(l_ptr, 1);
443
444 l_ptr->retransm_queue_head = 0;
445 l_ptr->retransm_queue_size = 0;
446 l_ptr->last_out = NULL;
447 l_ptr->first_out = NULL;
448 l_ptr->next_out = NULL;
449 l_ptr->unacked_window = 0;
450 l_ptr->checkpoint = 1;
451 l_ptr->next_out_no = 1;
452 l_ptr->deferred_inqueue_sz = 0;
453 l_ptr->oldest_deferred_in = NULL;
454 l_ptr->newest_deferred_in = NULL;
455 l_ptr->fsm_msg_cnt = 0;
456 l_ptr->stale_count = 0;
457 link_reset_statistics(l_ptr);
458}
459
460void tipc_link_reset_list(unsigned int bearer_id)
461{
462 struct tipc_link *l_ptr;
463 struct tipc_node *n_ptr;
464
465 rcu_read_lock();
466 list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
467 spin_lock_bh(&n_ptr->lock);
468 l_ptr = n_ptr->links[bearer_id];
469 if (l_ptr)
470 tipc_link_reset(l_ptr);
471 spin_unlock_bh(&n_ptr->lock);
472 }
473 rcu_read_unlock();
474}
475
476static void link_activate(struct tipc_link *l_ptr)
477{
478 l_ptr->next_in_no = l_ptr->stats.recv_info = 1;
479 tipc_node_link_up(l_ptr->owner, l_ptr);
480 tipc_bearer_add_dest(l_ptr->b_ptr, l_ptr->addr);
481}
482
483/**
484 * link_state_event - link finite state machine
485 * @l_ptr: pointer to link
486 * @event: state machine event to process
487 */
488static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
489{
490 struct tipc_link *other;
491 u32 cont_intv = l_ptr->continuity_interval;
492
493 if (l_ptr->flags & LINK_STOPPED)
494 return;
495
496 if (!(l_ptr->flags & LINK_STARTED) && (event != STARTING_EVT))
497 return; /* Not yet. */
498
499 /* Check whether changeover is going on */
500 if (l_ptr->exp_msg_count) {
501 if (event == TIMEOUT_EVT)
502 link_set_timer(l_ptr, cont_intv);
503 return;
504 }
505
506 switch (l_ptr->state) {
507 case WORKING_WORKING:
508 switch (event) {
509 case TRAFFIC_MSG_EVT:
510 case ACTIVATE_MSG:
511 break;
512 case TIMEOUT_EVT:
513 if (l_ptr->next_in_no != l_ptr->checkpoint) {
514 l_ptr->checkpoint = l_ptr->next_in_no;
515 if (tipc_bclink_acks_missing(l_ptr->owner)) {
516 tipc_link_proto_xmit(l_ptr, STATE_MSG,
517 0, 0, 0, 0, 0);
518 l_ptr->fsm_msg_cnt++;
519 } else if (l_ptr->max_pkt < l_ptr->max_pkt_target) {
520 tipc_link_proto_xmit(l_ptr, STATE_MSG,
521 1, 0, 0, 0, 0);
522 l_ptr->fsm_msg_cnt++;
523 }
524 link_set_timer(l_ptr, cont_intv);
525 break;
526 }
527 l_ptr->state = WORKING_UNKNOWN;
528 l_ptr->fsm_msg_cnt = 0;
529 tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
530 l_ptr->fsm_msg_cnt++;
531 link_set_timer(l_ptr, cont_intv / 4);
532 break;
533 case RESET_MSG:
534 pr_info("%s<%s>, requested by peer\n", link_rst_msg,
535 l_ptr->name);
536 tipc_link_reset(l_ptr);
537 l_ptr->state = RESET_RESET;
538 l_ptr->fsm_msg_cnt = 0;
539 tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
540 0, 0, 0, 0, 0);
541 l_ptr->fsm_msg_cnt++;
542 link_set_timer(l_ptr, cont_intv);
543 break;
544 default:
545 pr_err("%s%u in WW state\n", link_unk_evt, event);
546 }
547 break;
548 case WORKING_UNKNOWN:
549 switch (event) {
550 case TRAFFIC_MSG_EVT:
551 case ACTIVATE_MSG:
552 l_ptr->state = WORKING_WORKING;
553 l_ptr->fsm_msg_cnt = 0;
554 link_set_timer(l_ptr, cont_intv);
555 break;
556 case RESET_MSG:
557 pr_info("%s<%s>, requested by peer while probing\n",
558 link_rst_msg, l_ptr->name);
559 tipc_link_reset(l_ptr);
560 l_ptr->state = RESET_RESET;
561 l_ptr->fsm_msg_cnt = 0;
562 tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
563 0, 0, 0, 0, 0);
564 l_ptr->fsm_msg_cnt++;
565 link_set_timer(l_ptr, cont_intv);
566 break;
567 case TIMEOUT_EVT:
568 if (l_ptr->next_in_no != l_ptr->checkpoint) {
569 l_ptr->state = WORKING_WORKING;
570 l_ptr->fsm_msg_cnt = 0;
571 l_ptr->checkpoint = l_ptr->next_in_no;
572 if (tipc_bclink_acks_missing(l_ptr->owner)) {
573 tipc_link_proto_xmit(l_ptr, STATE_MSG,
574 0, 0, 0, 0, 0);
575 l_ptr->fsm_msg_cnt++;
576 }
577 link_set_timer(l_ptr, cont_intv);
578 } else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) {
579 tipc_link_proto_xmit(l_ptr, STATE_MSG,
580 1, 0, 0, 0, 0);
581 l_ptr->fsm_msg_cnt++;
582 link_set_timer(l_ptr, cont_intv / 4);
583 } else { /* Link has failed */
584 pr_warn("%s<%s>, peer not responding\n",
585 link_rst_msg, l_ptr->name);
586 tipc_link_reset(l_ptr);
587 l_ptr->state = RESET_UNKNOWN;
588 l_ptr->fsm_msg_cnt = 0;
589 tipc_link_proto_xmit(l_ptr, RESET_MSG,
590 0, 0, 0, 0, 0);
591 l_ptr->fsm_msg_cnt++;
592 link_set_timer(l_ptr, cont_intv);
593 }
594 break;
595 default:
596 pr_err("%s%u in WU state\n", link_unk_evt, event);
597 }
598 break;
599 case RESET_UNKNOWN:
600 switch (event) {
601 case TRAFFIC_MSG_EVT:
602 break;
603 case ACTIVATE_MSG:
604 other = l_ptr->owner->active_links[0];
605 if (other && link_working_unknown(other))
606 break;
607 l_ptr->state = WORKING_WORKING;
608 l_ptr->fsm_msg_cnt = 0;
609 link_activate(l_ptr);
610 tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
611 l_ptr->fsm_msg_cnt++;
612 if (l_ptr->owner->working_links == 1)
613 tipc_link_sync_xmit(l_ptr);
614 link_set_timer(l_ptr, cont_intv);
615 break;
616 case RESET_MSG:
617 l_ptr->state = RESET_RESET;
618 l_ptr->fsm_msg_cnt = 0;
619 tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
620 1, 0, 0, 0, 0);
621 l_ptr->fsm_msg_cnt++;
622 link_set_timer(l_ptr, cont_intv);
623 break;
624 case STARTING_EVT:
625 l_ptr->flags |= LINK_STARTED;
626 /* fall through */
627 case TIMEOUT_EVT:
628 tipc_link_proto_xmit(l_ptr, RESET_MSG, 0, 0, 0, 0, 0);
629 l_ptr->fsm_msg_cnt++;
630 link_set_timer(l_ptr, cont_intv);
631 break;
632 default:
633 pr_err("%s%u in RU state\n", link_unk_evt, event);
634 }
635 break;
636 case RESET_RESET:
637 switch (event) {
638 case TRAFFIC_MSG_EVT:
639 case ACTIVATE_MSG:
640 other = l_ptr->owner->active_links[0];
641 if (other && link_working_unknown(other))
642 break;
643 l_ptr->state = WORKING_WORKING;
644 l_ptr->fsm_msg_cnt = 0;
645 link_activate(l_ptr);
646 tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
647 l_ptr->fsm_msg_cnt++;
648 if (l_ptr->owner->working_links == 1)
649 tipc_link_sync_xmit(l_ptr);
650 link_set_timer(l_ptr, cont_intv);
651 break;
652 case RESET_MSG:
653 break;
654 case TIMEOUT_EVT:
655 tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
656 0, 0, 0, 0, 0);
657 l_ptr->fsm_msg_cnt++;
658 link_set_timer(l_ptr, cont_intv);
659 break;
660 default:
661 pr_err("%s%u in RR state\n", link_unk_evt, event);
662 }
663 break;
664 default:
665 pr_err("Unknown link state %u/%u\n", l_ptr->state, event);
666 }
667}
668
669/*
670 * link_bundle_buf(): Append contents of a buffer to
671 * the tail of an existing one.
672 */
673static int link_bundle_buf(struct tipc_link *l_ptr, struct sk_buff *bundler,
674 struct sk_buff *buf)
675{
676 struct tipc_msg *bundler_msg = buf_msg(bundler);
677 struct tipc_msg *msg = buf_msg(buf);
678 u32 size = msg_size(msg);
679 u32 bundle_size = msg_size(bundler_msg);
680 u32 to_pos = align(bundle_size);
681 u32 pad = to_pos - bundle_size;
682
683 if (msg_user(bundler_msg) != MSG_BUNDLER)
684 return 0;
685 if (msg_type(bundler_msg) != OPEN_MSG)
686 return 0;
687 if (skb_tailroom(bundler) < (pad + size))
688 return 0;
689 if (l_ptr->max_pkt < (to_pos + size))
690 return 0;
691
692 skb_put(bundler, pad + size);
693 skb_copy_to_linear_data_offset(bundler, to_pos, buf->data, size);
694 msg_set_size(bundler_msg, to_pos + size);
695 msg_set_msgcnt(bundler_msg, msg_msgcnt(bundler_msg) + 1);
696 kfree_skb(buf);
697 l_ptr->stats.sent_bundled++;
698 return 1;
699}
700
701static void link_add_to_outqueue(struct tipc_link *l_ptr,
702 struct sk_buff *buf,
703 struct tipc_msg *msg)
704{
705 u32 ack = mod(l_ptr->next_in_no - 1);
706 u32 seqno = mod(l_ptr->next_out_no++);
707
708 msg_set_word(msg, 2, ((ack << 16) | seqno));
709 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
710 buf->next = NULL;
711 if (l_ptr->first_out) {
712 l_ptr->last_out->next = buf;
713 l_ptr->last_out = buf;
714 } else
715 l_ptr->first_out = l_ptr->last_out = buf;
716
717 l_ptr->out_queue_size++;
718 if (l_ptr->out_queue_size > l_ptr->stats.max_queue_sz)
719 l_ptr->stats.max_queue_sz = l_ptr->out_queue_size;
720}
721
722static void link_add_chain_to_outqueue(struct tipc_link *l_ptr,
723 struct sk_buff *buf_chain,
724 u32 long_msgno)
725{
726 struct sk_buff *buf;
727 struct tipc_msg *msg;
728
729 if (!l_ptr->next_out)
730 l_ptr->next_out = buf_chain;
731 while (buf_chain) {
732 buf = buf_chain;
733 buf_chain = buf_chain->next;
734
735 msg = buf_msg(buf);
736 msg_set_long_msgno(msg, long_msgno);
737 link_add_to_outqueue(l_ptr, buf, msg);
738 }
739}
740
741/*
742 * tipc_link_xmit() is the 'full path' for messages, called from
743 * inside TIPC when the 'fast path' in tipc_send_xmit
744 * has failed, and from link_send()
745 */
746int __tipc_link_xmit(struct tipc_link *l_ptr, struct sk_buff *buf)
747{
748 struct tipc_msg *msg = buf_msg(buf);
749 u32 size = msg_size(msg);
750 u32 dsz = msg_data_sz(msg);
751 u32 queue_size = l_ptr->out_queue_size;
752 u32 imp = tipc_msg_tot_importance(msg);
753 u32 queue_limit = l_ptr->queue_limit[imp];
754 u32 max_packet = l_ptr->max_pkt;
755
756 /* Match msg importance against queue limits: */
757 if (unlikely(queue_size >= queue_limit)) {
758 if (imp <= TIPC_CRITICAL_IMPORTANCE) {
759 link_schedule_port(l_ptr, msg_origport(msg), size);
760 kfree_skb(buf);
761 return -ELINKCONG;
762 }
763 kfree_skb(buf);
764 if (imp > CONN_MANAGER) {
765 pr_warn("%s<%s>, send queue full", link_rst_msg,
766 l_ptr->name);
767 tipc_link_reset(l_ptr);
768 }
769 return dsz;
770 }
771
772 /* Fragmentation needed ? */
773 if (size > max_packet)
774 return tipc_link_frag_xmit(l_ptr, buf);
775
776 /* Packet can be queued or sent. */
777 if (likely(!link_congested(l_ptr))) {
778 link_add_to_outqueue(l_ptr, buf, msg);
779
780 tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
781 l_ptr->unacked_window = 0;
782 return dsz;
783 }
784 /* Congestion: can message be bundled ? */
785 if ((msg_user(msg) != CHANGEOVER_PROTOCOL) &&
786 (msg_user(msg) != MSG_FRAGMENTER)) {
787
788 /* Try adding message to an existing bundle */
789 if (l_ptr->next_out &&
790 link_bundle_buf(l_ptr, l_ptr->last_out, buf))
791 return dsz;
792
793 /* Try creating a new bundle */
794 if (size <= max_packet * 2 / 3) {
795 struct sk_buff *bundler = tipc_buf_acquire(max_packet);
796 struct tipc_msg bundler_hdr;
797
798 if (bundler) {
799 tipc_msg_init(&bundler_hdr, MSG_BUNDLER, OPEN_MSG,
800 INT_H_SIZE, l_ptr->addr);
801 skb_copy_to_linear_data(bundler, &bundler_hdr,
802 INT_H_SIZE);
803 skb_trim(bundler, INT_H_SIZE);
804 link_bundle_buf(l_ptr, bundler, buf);
805 buf = bundler;
806 msg = buf_msg(buf);
807 l_ptr->stats.sent_bundles++;
808 }
809 }
810 }
811 if (!l_ptr->next_out)
812 l_ptr->next_out = buf;
813 link_add_to_outqueue(l_ptr, buf, msg);
814 return dsz;
815}
816
817/*
818 * tipc_link_xmit(): same as __tipc_link_xmit(), but the link to use
819 * has not been selected yet, and the the owner node is not locked
820 * Called by TIPC internal users, e.g. the name distributor
821 */
822int tipc_link_xmit(struct sk_buff *buf, u32 dest, u32 selector)
823{
824 struct tipc_link *l_ptr;
825 struct tipc_node *n_ptr;
826 int res = -ELINKCONG;
827
828 read_lock_bh(&tipc_net_lock);
829 n_ptr = tipc_node_find(dest);
830 if (n_ptr) {
831 tipc_node_lock(n_ptr);
832 l_ptr = n_ptr->active_links[selector & 1];
833 if (l_ptr)
834 res = __tipc_link_xmit(l_ptr, buf);
835 else
836 kfree_skb(buf);
837 tipc_node_unlock(n_ptr);
838 } else {
839 kfree_skb(buf);
840 }
841 read_unlock_bh(&tipc_net_lock);
842 return res;
843}
844
845/*
846 * tipc_link_sync_xmit - synchronize broadcast link endpoints.
847 *
848 * Give a newly added peer node the sequence number where it should
849 * start receiving and acking broadcast packets.
850 *
851 * Called with node locked
852 */
853static void tipc_link_sync_xmit(struct tipc_link *l)
854{
855 struct sk_buff *buf;
856 struct tipc_msg *msg;
857
858 buf = tipc_buf_acquire(INT_H_SIZE);
859 if (!buf)
860 return;
861
862 msg = buf_msg(buf);
863 tipc_msg_init(msg, BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE, l->addr);
864 msg_set_last_bcast(msg, l->owner->bclink.acked);
865 link_add_chain_to_outqueue(l, buf, 0);
866 tipc_link_push_queue(l);
867}
868
869/*
870 * tipc_link_sync_rcv - synchronize broadcast link endpoints.
871 * Receive the sequence number where we should start receiving and
872 * acking broadcast packets from a newly added peer node, and open
873 * up for reception of such packets.
874 *
875 * Called with node locked
876 */
877static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf)
878{
879 struct tipc_msg *msg = buf_msg(buf);
880
881 n->bclink.last_sent = n->bclink.last_in = msg_last_bcast(msg);
882 n->bclink.recv_permitted = true;
883 kfree_skb(buf);
884}
885
886/*
887 * tipc_link_names_xmit - send name table entries to new neighbor
888 *
889 * Send routine for bulk delivery of name table messages when contact
890 * with a new neighbor occurs. No link congestion checking is performed
891 * because name table messages *must* be delivered. The messages must be
892 * small enough not to require fragmentation.
893 * Called without any locks held.
894 */
895void tipc_link_names_xmit(struct list_head *message_list, u32 dest)
896{
897 struct tipc_node *n_ptr;
898 struct tipc_link *l_ptr;
899 struct sk_buff *buf;
900 struct sk_buff *temp_buf;
901
902 if (list_empty(message_list))
903 return;
904
905 read_lock_bh(&tipc_net_lock);
906 n_ptr = tipc_node_find(dest);
907 if (n_ptr) {
908 tipc_node_lock(n_ptr);
909 l_ptr = n_ptr->active_links[0];
910 if (l_ptr) {
911 /* convert circular list to linear list */
912 ((struct sk_buff *)message_list->prev)->next = NULL;
913 link_add_chain_to_outqueue(l_ptr,
914 (struct sk_buff *)message_list->next, 0);
915 tipc_link_push_queue(l_ptr);
916 INIT_LIST_HEAD(message_list);
917 }
918 tipc_node_unlock(n_ptr);
919 }
920 read_unlock_bh(&tipc_net_lock);
921
922 /* discard the messages if they couldn't be sent */
923 list_for_each_safe(buf, temp_buf, ((struct sk_buff *)message_list)) {
924 list_del((struct list_head *)buf);
925 kfree_skb(buf);
926 }
927}
928
929/*
930 * tipc_link_xmit_fast: Entry for data messages where the
931 * destination link is known and the header is complete,
932 * inclusive total message length. Very time critical.
933 * Link is locked. Returns user data length.
934 */
935static int tipc_link_xmit_fast(struct tipc_link *l_ptr, struct sk_buff *buf,
936 u32 *used_max_pkt)
937{
938 struct tipc_msg *msg = buf_msg(buf);
939 int res = msg_data_sz(msg);
940
941 if (likely(!link_congested(l_ptr))) {
942 if (likely(msg_size(msg) <= l_ptr->max_pkt)) {
943 link_add_to_outqueue(l_ptr, buf, msg);
944 tipc_bearer_send(l_ptr->b_ptr, buf,
945 &l_ptr->media_addr);
946 l_ptr->unacked_window = 0;
947 return res;
948 }
949 else
950 *used_max_pkt = l_ptr->max_pkt;
951 }
952 return __tipc_link_xmit(l_ptr, buf); /* All other cases */
953}
954
955/*
956 * tipc_link_iovec_xmit_fast: Entry for messages where the
957 * destination processor is known and the header is complete,
958 * except for total message length.
959 * Returns user data length or errno.
960 */
961int tipc_link_iovec_xmit_fast(struct tipc_port *sender,
962 struct iovec const *msg_sect,
963 unsigned int len, u32 destaddr)
964{
965 struct tipc_msg *hdr = &sender->phdr;
966 struct tipc_link *l_ptr;
967 struct sk_buff *buf;
968 struct tipc_node *node;
969 int res;
970 u32 selector = msg_origport(hdr) & 1;
971
972again:
973 /*
974 * Try building message using port's max_pkt hint.
975 * (Must not hold any locks while building message.)
976 */
977 res = tipc_msg_build(hdr, msg_sect, len, sender->max_pkt, &buf);
978 /* Exit if build request was invalid */
979 if (unlikely(res < 0))
980 return res;
981
982 read_lock_bh(&tipc_net_lock);
983 node = tipc_node_find(destaddr);
984 if (likely(node)) {
985 tipc_node_lock(node);
986 l_ptr = node->active_links[selector];
987 if (likely(l_ptr)) {
988 if (likely(buf)) {
989 res = tipc_link_xmit_fast(l_ptr, buf,
990 &sender->max_pkt);
991exit:
992 tipc_node_unlock(node);
993 read_unlock_bh(&tipc_net_lock);
994 return res;
995 }
996
997 /* Exit if link (or bearer) is congested */
998 if (link_congested(l_ptr)) {
999 res = link_schedule_port(l_ptr,
1000 sender->ref, res);
1001 goto exit;
1002 }
1003
1004 /*
1005 * Message size exceeds max_pkt hint; update hint,
1006 * then re-try fast path or fragment the message
1007 */
1008 sender->max_pkt = l_ptr->max_pkt;
1009 tipc_node_unlock(node);
1010 read_unlock_bh(&tipc_net_lock);
1011
1012
1013 if ((msg_hdr_sz(hdr) + res) <= sender->max_pkt)
1014 goto again;
1015
1016 return tipc_link_iovec_long_xmit(sender, msg_sect,
1017 len, destaddr);
1018 }
1019 tipc_node_unlock(node);
1020 }
1021 read_unlock_bh(&tipc_net_lock);
1022
1023 /* Couldn't find a link to the destination node */
1024 kfree_skb(buf);
1025 tipc_port_iovec_reject(sender, hdr, msg_sect, len, TIPC_ERR_NO_NODE);
1026 return -ENETUNREACH;
1027}
1028
1029/*
1030 * tipc_link_iovec_long_xmit(): Entry for long messages where the
1031 * destination node is known and the header is complete,
1032 * inclusive total message length.
1033 * Link and bearer congestion status have been checked to be ok,
1034 * and are ignored if they change.
1035 *
1036 * Note that fragments do not use the full link MTU so that they won't have
1037 * to undergo refragmentation if link changeover causes them to be sent
1038 * over another link with an additional tunnel header added as prefix.
1039 * (Refragmentation will still occur if the other link has a smaller MTU.)
1040 *
1041 * Returns user data length or errno.
1042 */
1043static int tipc_link_iovec_long_xmit(struct tipc_port *sender,
1044 struct iovec const *msg_sect,
1045 unsigned int len, u32 destaddr)
1046{
1047 struct tipc_link *l_ptr;
1048 struct tipc_node *node;
1049 struct tipc_msg *hdr = &sender->phdr;
1050 u32 dsz = len;
1051 u32 max_pkt, fragm_sz, rest;
1052 struct tipc_msg fragm_hdr;
1053 struct sk_buff *buf, *buf_chain, *prev;
1054 u32 fragm_crs, fragm_rest, hsz, sect_rest;
1055 const unchar __user *sect_crs;
1056 int curr_sect;
1057 u32 fragm_no;
1058 int res = 0;
1059
1060again:
1061 fragm_no = 1;
1062 max_pkt = sender->max_pkt - INT_H_SIZE;
1063 /* leave room for tunnel header in case of link changeover */
1064 fragm_sz = max_pkt - INT_H_SIZE;
1065 /* leave room for fragmentation header in each fragment */
1066 rest = dsz;
1067 fragm_crs = 0;
1068 fragm_rest = 0;
1069 sect_rest = 0;
1070 sect_crs = NULL;
1071 curr_sect = -1;
1072
1073 /* Prepare reusable fragment header */
1074 tipc_msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
1075 INT_H_SIZE, msg_destnode(hdr));
1076 msg_set_size(&fragm_hdr, max_pkt);
1077 msg_set_fragm_no(&fragm_hdr, 1);
1078
1079 /* Prepare header of first fragment */
1080 buf_chain = buf = tipc_buf_acquire(max_pkt);
1081 if (!buf)
1082 return -ENOMEM;
1083 buf->next = NULL;
1084 skb_copy_to_linear_data(buf, &fragm_hdr, INT_H_SIZE);
1085 hsz = msg_hdr_sz(hdr);
1086 skb_copy_to_linear_data_offset(buf, INT_H_SIZE, hdr, hsz);
1087
1088 /* Chop up message */
1089 fragm_crs = INT_H_SIZE + hsz;
1090 fragm_rest = fragm_sz - hsz;
1091
1092 do { /* For all sections */
1093 u32 sz;
1094
1095 if (!sect_rest) {
1096 sect_rest = msg_sect[++curr_sect].iov_len;
1097 sect_crs = msg_sect[curr_sect].iov_base;
1098 }
1099
1100 if (sect_rest < fragm_rest)
1101 sz = sect_rest;
1102 else
1103 sz = fragm_rest;
1104
1105 if (copy_from_user(buf->data + fragm_crs, sect_crs, sz)) {
1106 res = -EFAULT;
1107error:
1108 kfree_skb_list(buf_chain);
1109 return res;
1110 }
1111 sect_crs += sz;
1112 sect_rest -= sz;
1113 fragm_crs += sz;
1114 fragm_rest -= sz;
1115 rest -= sz;
1116
1117 if (!fragm_rest && rest) {
1118
1119 /* Initiate new fragment: */
1120 if (rest <= fragm_sz) {
1121 fragm_sz = rest;
1122 msg_set_type(&fragm_hdr, LAST_FRAGMENT);
1123 } else {
1124 msg_set_type(&fragm_hdr, FRAGMENT);
1125 }
1126 msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
1127 msg_set_fragm_no(&fragm_hdr, ++fragm_no);
1128 prev = buf;
1129 buf = tipc_buf_acquire(fragm_sz + INT_H_SIZE);
1130 if (!buf) {
1131 res = -ENOMEM;
1132 goto error;
1133 }
1134
1135 buf->next = NULL;
1136 prev->next = buf;
1137 skb_copy_to_linear_data(buf, &fragm_hdr, INT_H_SIZE);
1138 fragm_crs = INT_H_SIZE;
1139 fragm_rest = fragm_sz;
1140 }
1141 } while (rest > 0);
1142
1143 /*
1144 * Now we have a buffer chain. Select a link and check
1145 * that packet size is still OK
1146 */
1147 node = tipc_node_find(destaddr);
1148 if (likely(node)) {
1149 tipc_node_lock(node);
1150 l_ptr = node->active_links[sender->ref & 1];
1151 if (!l_ptr) {
1152 tipc_node_unlock(node);
1153 goto reject;
1154 }
1155 if (l_ptr->max_pkt < max_pkt) {
1156 sender->max_pkt = l_ptr->max_pkt;
1157 tipc_node_unlock(node);
1158 kfree_skb_list(buf_chain);
1159 goto again;
1160 }
1161 } else {
1162reject:
1163 kfree_skb_list(buf_chain);
1164 tipc_port_iovec_reject(sender, hdr, msg_sect, len,
1165 TIPC_ERR_NO_NODE);
1166 return -ENETUNREACH;
1167 }
1168
1169 /* Append chain of fragments to send queue & send them */
1170 l_ptr->long_msg_seq_no++;
1171 link_add_chain_to_outqueue(l_ptr, buf_chain, l_ptr->long_msg_seq_no);
1172 l_ptr->stats.sent_fragments += fragm_no;
1173 l_ptr->stats.sent_fragmented++;
1174 tipc_link_push_queue(l_ptr);
1175 tipc_node_unlock(node);
1176 return dsz;
1177}
1178
1179/*
1180 * tipc_link_push_packet: Push one unsent packet to the media
1181 */
1182static u32 tipc_link_push_packet(struct tipc_link *l_ptr)
1183{
1184 struct sk_buff *buf = l_ptr->first_out;
1185 u32 r_q_size = l_ptr->retransm_queue_size;
1186 u32 r_q_head = l_ptr->retransm_queue_head;
1187
1188 /* Step to position where retransmission failed, if any, */
1189 /* consider that buffers may have been released in meantime */
1190 if (r_q_size && buf) {
1191 u32 last = lesser(mod(r_q_head + r_q_size),
1192 link_last_sent(l_ptr));
1193 u32 first = buf_seqno(buf);
1194
1195 while (buf && less(first, r_q_head)) {
1196 first = mod(first + 1);
1197 buf = buf->next;
1198 }
1199 l_ptr->retransm_queue_head = r_q_head = first;
1200 l_ptr->retransm_queue_size = r_q_size = mod(last - first);
1201 }
1202
1203 /* Continue retransmission now, if there is anything: */
1204 if (r_q_size && buf) {
1205 msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
1206 msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
1207 tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
1208 l_ptr->retransm_queue_head = mod(++r_q_head);
1209 l_ptr->retransm_queue_size = --r_q_size;
1210 l_ptr->stats.retransmitted++;
1211 return 0;
1212 }
1213
1214 /* Send deferred protocol message, if any: */
1215 buf = l_ptr->proto_msg_queue;
1216 if (buf) {
1217 msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
1218 msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
1219 tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
1220 l_ptr->unacked_window = 0;
1221 kfree_skb(buf);
1222 l_ptr->proto_msg_queue = NULL;
1223 return 0;
1224 }
1225
1226 /* Send one deferred data message, if send window not full: */
1227 buf = l_ptr->next_out;
1228 if (buf) {
1229 struct tipc_msg *msg = buf_msg(buf);
1230 u32 next = msg_seqno(msg);
1231 u32 first = buf_seqno(l_ptr->first_out);
1232
1233 if (mod(next - first) < l_ptr->queue_limit[0]) {
1234 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1235 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1236 tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
1237 if (msg_user(msg) == MSG_BUNDLER)
1238 msg_set_type(msg, CLOSED_MSG);
1239 l_ptr->next_out = buf->next;
1240 return 0;
1241 }
1242 }
1243 return 1;
1244}
1245
1246/*
1247 * push_queue(): push out the unsent messages of a link where
1248 * congestion has abated. Node is locked
1249 */
1250void tipc_link_push_queue(struct tipc_link *l_ptr)
1251{
1252 u32 res;
1253
1254 do {
1255 res = tipc_link_push_packet(l_ptr);
1256 } while (!res);
1257}
1258
1259static void link_reset_all(unsigned long addr)
1260{
1261 struct tipc_node *n_ptr;
1262 char addr_string[16];
1263 u32 i;
1264
1265 read_lock_bh(&tipc_net_lock);
1266 n_ptr = tipc_node_find((u32)addr);
1267 if (!n_ptr) {
1268 read_unlock_bh(&tipc_net_lock);
1269 return; /* node no longer exists */
1270 }
1271
1272 tipc_node_lock(n_ptr);
1273
1274 pr_warn("Resetting all links to %s\n",
1275 tipc_addr_string_fill(addr_string, n_ptr->addr));
1276
1277 for (i = 0; i < MAX_BEARERS; i++) {
1278 if (n_ptr->links[i]) {
1279 link_print(n_ptr->links[i], "Resetting link\n");
1280 tipc_link_reset(n_ptr->links[i]);
1281 }
1282 }
1283
1284 tipc_node_unlock(n_ptr);
1285 read_unlock_bh(&tipc_net_lock);
1286}
1287
1288static void link_retransmit_failure(struct tipc_link *l_ptr,
1289 struct sk_buff *buf)
1290{
1291 struct tipc_msg *msg = buf_msg(buf);
1292
1293 pr_warn("Retransmission failure on link <%s>\n", l_ptr->name);
1294
1295 if (l_ptr->addr) {
1296 /* Handle failure on standard link */
1297 link_print(l_ptr, "Resetting link\n");
1298 tipc_link_reset(l_ptr);
1299
1300 } else {
1301 /* Handle failure on broadcast link */
1302 struct tipc_node *n_ptr;
1303 char addr_string[16];
1304
1305 pr_info("Msg seq number: %u, ", msg_seqno(msg));
1306 pr_cont("Outstanding acks: %lu\n",
1307 (unsigned long) TIPC_SKB_CB(buf)->handle);
1308
1309 n_ptr = tipc_bclink_retransmit_to();
1310 tipc_node_lock(n_ptr);
1311
1312 tipc_addr_string_fill(addr_string, n_ptr->addr);
1313 pr_info("Broadcast link info for %s\n", addr_string);
1314 pr_info("Reception permitted: %d, Acked: %u\n",
1315 n_ptr->bclink.recv_permitted,
1316 n_ptr->bclink.acked);
1317 pr_info("Last in: %u, Oos state: %u, Last sent: %u\n",
1318 n_ptr->bclink.last_in,
1319 n_ptr->bclink.oos_state,
1320 n_ptr->bclink.last_sent);
1321
1322 tipc_k_signal((Handler)link_reset_all, (unsigned long)n_ptr->addr);
1323
1324 tipc_node_unlock(n_ptr);
1325
1326 l_ptr->stale_count = 0;
1327 }
1328}
1329
1330void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *buf,
1331 u32 retransmits)
1332{
1333 struct tipc_msg *msg;
1334
1335 if (!buf)
1336 return;
1337
1338 msg = buf_msg(buf);
1339
1340 /* Detect repeated retransmit failures */
1341 if (l_ptr->last_retransmitted == msg_seqno(msg)) {
1342 if (++l_ptr->stale_count > 100) {
1343 link_retransmit_failure(l_ptr, buf);
1344 return;
1345 }
1346 } else {
1347 l_ptr->last_retransmitted = msg_seqno(msg);
1348 l_ptr->stale_count = 1;
1349 }
1350
1351 while (retransmits && (buf != l_ptr->next_out) && buf) {
1352 msg = buf_msg(buf);
1353 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1354 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1355 tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
1356 buf = buf->next;
1357 retransmits--;
1358 l_ptr->stats.retransmitted++;
1359 }
1360
1361 l_ptr->retransm_queue_head = l_ptr->retransm_queue_size = 0;
1362}
1363
1364/**
1365 * link_insert_deferred_queue - insert deferred messages back into receive chain
1366 */
1367static struct sk_buff *link_insert_deferred_queue(struct tipc_link *l_ptr,
1368 struct sk_buff *buf)
1369{
1370 u32 seq_no;
1371
1372 if (l_ptr->oldest_deferred_in == NULL)
1373 return buf;
1374
1375 seq_no = buf_seqno(l_ptr->oldest_deferred_in);
1376 if (seq_no == mod(l_ptr->next_in_no)) {
1377 l_ptr->newest_deferred_in->next = buf;
1378 buf = l_ptr->oldest_deferred_in;
1379 l_ptr->oldest_deferred_in = NULL;
1380 l_ptr->deferred_inqueue_sz = 0;
1381 }
1382 return buf;
1383}
1384
1385/**
1386 * link_recv_buf_validate - validate basic format of received message
1387 *
1388 * This routine ensures a TIPC message has an acceptable header, and at least
1389 * as much data as the header indicates it should. The routine also ensures
1390 * that the entire message header is stored in the main fragment of the message
1391 * buffer, to simplify future access to message header fields.
1392 *
1393 * Note: Having extra info present in the message header or data areas is OK.
1394 * TIPC will ignore the excess, under the assumption that it is optional info
1395 * introduced by a later release of the protocol.
1396 */
1397static int link_recv_buf_validate(struct sk_buff *buf)
1398{
1399 static u32 min_data_hdr_size[8] = {
1400 SHORT_H_SIZE, MCAST_H_SIZE, NAMED_H_SIZE, BASIC_H_SIZE,
1401 MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE
1402 };
1403
1404 struct tipc_msg *msg;
1405 u32 tipc_hdr[2];
1406 u32 size;
1407 u32 hdr_size;
1408 u32 min_hdr_size;
1409
1410 /* If this packet comes from the defer queue, the skb has already
1411 * been validated
1412 */
1413 if (unlikely(TIPC_SKB_CB(buf)->deferred))
1414 return 1;
1415
1416 if (unlikely(buf->len < MIN_H_SIZE))
1417 return 0;
1418
1419 msg = skb_header_pointer(buf, 0, sizeof(tipc_hdr), tipc_hdr);
1420 if (msg == NULL)
1421 return 0;
1422
1423 if (unlikely(msg_version(msg) != TIPC_VERSION))
1424 return 0;
1425
1426 size = msg_size(msg);
1427 hdr_size = msg_hdr_sz(msg);
1428 min_hdr_size = msg_isdata(msg) ?
1429 min_data_hdr_size[msg_type(msg)] : INT_H_SIZE;
1430
1431 if (unlikely((hdr_size < min_hdr_size) ||
1432 (size < hdr_size) ||
1433 (buf->len < size) ||
1434 (size - hdr_size > TIPC_MAX_USER_MSG_SIZE)))
1435 return 0;
1436
1437 return pskb_may_pull(buf, hdr_size);
1438}
1439
1440/**
1441 * tipc_rcv - process TIPC packets/messages arriving from off-node
1442 * @head: pointer to message buffer chain
1443 * @tb_ptr: pointer to bearer message arrived on
1444 *
1445 * Invoked with no locks held. Bearer pointer must point to a valid bearer
1446 * structure (i.e. cannot be NULL), but bearer can be inactive.
1447 */
1448void tipc_rcv(struct sk_buff *head, struct tipc_bearer *b_ptr)
1449{
1450 read_lock_bh(&tipc_net_lock);
1451 while (head) {
1452 struct tipc_node *n_ptr;
1453 struct tipc_link *l_ptr;
1454 struct sk_buff *crs;
1455 struct sk_buff *buf = head;
1456 struct tipc_msg *msg;
1457 u32 seq_no;
1458 u32 ackd;
1459 u32 released = 0;
1460
1461 head = head->next;
1462 buf->next = NULL;
1463
1464 /* Ensure message is well-formed */
1465 if (unlikely(!link_recv_buf_validate(buf)))
1466 goto discard;
1467
1468 /* Ensure message data is a single contiguous unit */
1469 if (unlikely(skb_linearize(buf)))
1470 goto discard;
1471
1472 /* Handle arrival of a non-unicast link message */
1473 msg = buf_msg(buf);
1474
1475 if (unlikely(msg_non_seq(msg))) {
1476 if (msg_user(msg) == LINK_CONFIG)
1477 tipc_disc_rcv(buf, b_ptr);
1478 else
1479 tipc_bclink_rcv(buf);
1480 continue;
1481 }
1482
1483 /* Discard unicast link messages destined for another node */
1484 if (unlikely(!msg_short(msg) &&
1485 (msg_destnode(msg) != tipc_own_addr)))
1486 goto discard;
1487
1488 /* Locate neighboring node that sent message */
1489 n_ptr = tipc_node_find(msg_prevnode(msg));
1490 if (unlikely(!n_ptr))
1491 goto discard;
1492 tipc_node_lock(n_ptr);
1493
1494 /* Locate unicast link endpoint that should handle message */
1495 l_ptr = n_ptr->links[b_ptr->identity];
1496 if (unlikely(!l_ptr))
1497 goto unlock_discard;
1498
1499 /* Verify that communication with node is currently allowed */
1500 if ((n_ptr->block_setup & WAIT_PEER_DOWN) &&
1501 msg_user(msg) == LINK_PROTOCOL &&
1502 (msg_type(msg) == RESET_MSG ||
1503 msg_type(msg) == ACTIVATE_MSG) &&
1504 !msg_redundant_link(msg))
1505 n_ptr->block_setup &= ~WAIT_PEER_DOWN;
1506
1507 if (n_ptr->block_setup)
1508 goto unlock_discard;
1509
1510 /* Validate message sequence number info */
1511 seq_no = msg_seqno(msg);
1512 ackd = msg_ack(msg);
1513
1514 /* Release acked messages */
1515 if (n_ptr->bclink.recv_permitted)
1516 tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
1517
1518 crs = l_ptr->first_out;
1519 while ((crs != l_ptr->next_out) &&
1520 less_eq(buf_seqno(crs), ackd)) {
1521 struct sk_buff *next = crs->next;
1522 kfree_skb(crs);
1523 crs = next;
1524 released++;
1525 }
1526 if (released) {
1527 l_ptr->first_out = crs;
1528 l_ptr->out_queue_size -= released;
1529 }
1530
1531 /* Try sending any messages link endpoint has pending */
1532 if (unlikely(l_ptr->next_out))
1533 tipc_link_push_queue(l_ptr);
1534
1535 if (unlikely(!list_empty(&l_ptr->waiting_ports)))
1536 tipc_link_wakeup_ports(l_ptr, 0);
1537
1538 if (unlikely(++l_ptr->unacked_window >= TIPC_MIN_LINK_WIN)) {
1539 l_ptr->stats.sent_acks++;
1540 tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1541 }
1542
1543 /* Process the incoming packet */
1544 if (unlikely(!link_working_working(l_ptr))) {
1545 if (msg_user(msg) == LINK_PROTOCOL) {
1546 tipc_link_proto_rcv(l_ptr, buf);
1547 head = link_insert_deferred_queue(l_ptr, head);
1548 tipc_node_unlock(n_ptr);
1549 continue;
1550 }
1551
1552 /* Traffic message. Conditionally activate link */
1553 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1554
1555 if (link_working_working(l_ptr)) {
1556 /* Re-insert buffer in front of queue */
1557 buf->next = head;
1558 head = buf;
1559 tipc_node_unlock(n_ptr);
1560 continue;
1561 }
1562 goto unlock_discard;
1563 }
1564
1565 /* Link is now in state WORKING_WORKING */
1566 if (unlikely(seq_no != mod(l_ptr->next_in_no))) {
1567 link_handle_out_of_seq_msg(l_ptr, buf);
1568 head = link_insert_deferred_queue(l_ptr, head);
1569 tipc_node_unlock(n_ptr);
1570 continue;
1571 }
1572 l_ptr->next_in_no++;
1573 if (unlikely(l_ptr->oldest_deferred_in))
1574 head = link_insert_deferred_queue(l_ptr, head);
1575
1576 /* Deliver packet/message to correct user: */
1577 if (unlikely(msg_user(msg) == CHANGEOVER_PROTOCOL)) {
1578 if (!tipc_link_tunnel_rcv(n_ptr, &buf)) {
1579 tipc_node_unlock(n_ptr);
1580 continue;
1581 }
1582 msg = buf_msg(buf);
1583 } else if (msg_user(msg) == MSG_FRAGMENTER) {
1584 int rc;
1585
1586 l_ptr->stats.recv_fragments++;
1587 rc = tipc_link_frag_rcv(&l_ptr->reasm_head,
1588 &l_ptr->reasm_tail,
1589 &buf);
1590 if (rc == LINK_REASM_COMPLETE) {
1591 l_ptr->stats.recv_fragmented++;
1592 msg = buf_msg(buf);
1593 } else {
1594 if (rc == LINK_REASM_ERROR)
1595 tipc_link_reset(l_ptr);
1596 tipc_node_unlock(n_ptr);
1597 continue;
1598 }
1599 }
1600
1601 switch (msg_user(msg)) {
1602 case TIPC_LOW_IMPORTANCE:
1603 case TIPC_MEDIUM_IMPORTANCE:
1604 case TIPC_HIGH_IMPORTANCE:
1605 case TIPC_CRITICAL_IMPORTANCE:
1606 tipc_node_unlock(n_ptr);
1607 tipc_port_rcv(buf);
1608 continue;
1609 case MSG_BUNDLER:
1610 l_ptr->stats.recv_bundles++;
1611 l_ptr->stats.recv_bundled += msg_msgcnt(msg);
1612 tipc_node_unlock(n_ptr);
1613 tipc_link_bundle_rcv(buf);
1614 continue;
1615 case NAME_DISTRIBUTOR:
1616 n_ptr->bclink.recv_permitted = true;
1617 tipc_node_unlock(n_ptr);
1618 tipc_named_rcv(buf);
1619 continue;
1620 case CONN_MANAGER:
1621 tipc_node_unlock(n_ptr);
1622 tipc_port_proto_rcv(buf);
1623 continue;
1624 case BCAST_PROTOCOL:
1625 tipc_link_sync_rcv(n_ptr, buf);
1626 break;
1627 default:
1628 kfree_skb(buf);
1629 break;
1630 }
1631 tipc_node_unlock(n_ptr);
1632 continue;
1633unlock_discard:
1634 tipc_node_unlock(n_ptr);
1635discard:
1636 kfree_skb(buf);
1637 }
1638 read_unlock_bh(&tipc_net_lock);
1639}
1640
1641/**
1642 * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
1643 *
1644 * Returns increase in queue length (i.e. 0 or 1)
1645 */
1646u32 tipc_link_defer_pkt(struct sk_buff **head, struct sk_buff **tail,
1647 struct sk_buff *buf)
1648{
1649 struct sk_buff *queue_buf;
1650 struct sk_buff **prev;
1651 u32 seq_no = buf_seqno(buf);
1652
1653 buf->next = NULL;
1654
1655 /* Empty queue ? */
1656 if (*head == NULL) {
1657 *head = *tail = buf;
1658 return 1;
1659 }
1660
1661 /* Last ? */
1662 if (less(buf_seqno(*tail), seq_no)) {
1663 (*tail)->next = buf;
1664 *tail = buf;
1665 return 1;
1666 }
1667
1668 /* Locate insertion point in queue, then insert; discard if duplicate */
1669 prev = head;
1670 queue_buf = *head;
1671 for (;;) {
1672 u32 curr_seqno = buf_seqno(queue_buf);
1673
1674 if (seq_no == curr_seqno) {
1675 kfree_skb(buf);
1676 return 0;
1677 }
1678
1679 if (less(seq_no, curr_seqno))
1680 break;
1681
1682 prev = &queue_buf->next;
1683 queue_buf = queue_buf->next;
1684 }
1685
1686 buf->next = queue_buf;
1687 *prev = buf;
1688 return 1;
1689}
1690
1691/*
1692 * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
1693 */
1694static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
1695 struct sk_buff *buf)
1696{
1697 u32 seq_no = buf_seqno(buf);
1698
1699 if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) {
1700 tipc_link_proto_rcv(l_ptr, buf);
1701 return;
1702 }
1703
1704 /* Record OOS packet arrival (force mismatch on next timeout) */
1705 l_ptr->checkpoint--;
1706
1707 /*
1708 * Discard packet if a duplicate; otherwise add it to deferred queue
1709 * and notify peer of gap as per protocol specification
1710 */
1711 if (less(seq_no, mod(l_ptr->next_in_no))) {
1712 l_ptr->stats.duplicates++;
1713 kfree_skb(buf);
1714 return;
1715 }
1716
1717 if (tipc_link_defer_pkt(&l_ptr->oldest_deferred_in,
1718 &l_ptr->newest_deferred_in, buf)) {
1719 l_ptr->deferred_inqueue_sz++;
1720 l_ptr->stats.deferred_recv++;
1721 TIPC_SKB_CB(buf)->deferred = true;
1722 if ((l_ptr->deferred_inqueue_sz % 16) == 1)
1723 tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1724 } else
1725 l_ptr->stats.duplicates++;
1726}
1727
1728/*
1729 * Send protocol message to the other endpoint.
1730 */
1731void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int probe_msg,
1732 u32 gap, u32 tolerance, u32 priority, u32 ack_mtu)
1733{
1734 struct sk_buff *buf = NULL;
1735 struct tipc_msg *msg = l_ptr->pmsg;
1736 u32 msg_size = sizeof(l_ptr->proto_msg);
1737 int r_flag;
1738
1739 /* Discard any previous message that was deferred due to congestion */
1740 if (l_ptr->proto_msg_queue) {
1741 kfree_skb(l_ptr->proto_msg_queue);
1742 l_ptr->proto_msg_queue = NULL;
1743 }
1744
1745 /* Don't send protocol message during link changeover */
1746 if (l_ptr->exp_msg_count)
1747 return;
1748
1749 /* Abort non-RESET send if communication with node is prohibited */
1750 if ((l_ptr->owner->block_setup) && (msg_typ != RESET_MSG))
1751 return;
1752
1753 /* Create protocol message with "out-of-sequence" sequence number */
1754 msg_set_type(msg, msg_typ);
1755 msg_set_net_plane(msg, l_ptr->b_ptr->net_plane);
1756 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1757 msg_set_last_bcast(msg, tipc_bclink_get_last_sent());
1758
1759 if (msg_typ == STATE_MSG) {
1760 u32 next_sent = mod(l_ptr->next_out_no);
1761
1762 if (!tipc_link_is_up(l_ptr))
1763 return;
1764 if (l_ptr->next_out)
1765 next_sent = buf_seqno(l_ptr->next_out);
1766 msg_set_next_sent(msg, next_sent);
1767 if (l_ptr->oldest_deferred_in) {
1768 u32 rec = buf_seqno(l_ptr->oldest_deferred_in);
1769 gap = mod(rec - mod(l_ptr->next_in_no));
1770 }
1771 msg_set_seq_gap(msg, gap);
1772 if (gap)
1773 l_ptr->stats.sent_nacks++;
1774 msg_set_link_tolerance(msg, tolerance);
1775 msg_set_linkprio(msg, priority);
1776 msg_set_max_pkt(msg, ack_mtu);
1777 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1778 msg_set_probe(msg, probe_msg != 0);
1779 if (probe_msg) {
1780 u32 mtu = l_ptr->max_pkt;
1781
1782 if ((mtu < l_ptr->max_pkt_target) &&
1783 link_working_working(l_ptr) &&
1784 l_ptr->fsm_msg_cnt) {
1785 msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
1786 if (l_ptr->max_pkt_probes == 10) {
1787 l_ptr->max_pkt_target = (msg_size - 4);
1788 l_ptr->max_pkt_probes = 0;
1789 msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
1790 }
1791 l_ptr->max_pkt_probes++;
1792 }
1793
1794 l_ptr->stats.sent_probes++;
1795 }
1796 l_ptr->stats.sent_states++;
1797 } else { /* RESET_MSG or ACTIVATE_MSG */
1798 msg_set_ack(msg, mod(l_ptr->reset_checkpoint - 1));
1799 msg_set_seq_gap(msg, 0);
1800 msg_set_next_sent(msg, 1);
1801 msg_set_probe(msg, 0);
1802 msg_set_link_tolerance(msg, l_ptr->tolerance);
1803 msg_set_linkprio(msg, l_ptr->priority);
1804 msg_set_max_pkt(msg, l_ptr->max_pkt_target);
1805 }
1806
1807 r_flag = (l_ptr->owner->working_links > tipc_link_is_up(l_ptr));
1808 msg_set_redundant_link(msg, r_flag);
1809 msg_set_linkprio(msg, l_ptr->priority);
1810 msg_set_size(msg, msg_size);
1811
1812 msg_set_seqno(msg, mod(l_ptr->next_out_no + (0xffff/2)));
1813
1814 buf = tipc_buf_acquire(msg_size);
1815 if (!buf)
1816 return;
1817
1818 skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
1819 buf->priority = TC_PRIO_CONTROL;
1820
1821 tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
1822 l_ptr->unacked_window = 0;
1823 kfree_skb(buf);
1824}
1825
1826/*
1827 * Receive protocol message :
1828 * Note that network plane id propagates through the network, and may
1829 * change at any time. The node with lowest address rules
1830 */
1831static void tipc_link_proto_rcv(struct tipc_link *l_ptr, struct sk_buff *buf)
1832{
1833 u32 rec_gap = 0;
1834 u32 max_pkt_info;
1835 u32 max_pkt_ack;
1836 u32 msg_tol;
1837 struct tipc_msg *msg = buf_msg(buf);
1838
1839 /* Discard protocol message during link changeover */
1840 if (l_ptr->exp_msg_count)
1841 goto exit;
1842
1843 /* record unnumbered packet arrival (force mismatch on next timeout) */
1844 l_ptr->checkpoint--;
1845
1846 if (l_ptr->b_ptr->net_plane != msg_net_plane(msg))
1847 if (tipc_own_addr > msg_prevnode(msg))
1848 l_ptr->b_ptr->net_plane = msg_net_plane(msg);
1849
1850 switch (msg_type(msg)) {
1851
1852 case RESET_MSG:
1853 if (!link_working_unknown(l_ptr) &&
1854 (l_ptr->peer_session != INVALID_SESSION)) {
1855 if (less_eq(msg_session(msg), l_ptr->peer_session))
1856 break; /* duplicate or old reset: ignore */
1857 }
1858
1859 if (!msg_redundant_link(msg) && (link_working_working(l_ptr) ||
1860 link_working_unknown(l_ptr))) {
1861 /*
1862 * peer has lost contact -- don't allow peer's links
1863 * to reactivate before we recognize loss & clean up
1864 */
1865 l_ptr->owner->block_setup = WAIT_NODE_DOWN;
1866 }
1867
1868 link_state_event(l_ptr, RESET_MSG);
1869
1870 /* fall thru' */
1871 case ACTIVATE_MSG:
1872 /* Update link settings according other endpoint's values */
1873 strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg));
1874
1875 msg_tol = msg_link_tolerance(msg);
1876 if (msg_tol > l_ptr->tolerance)
1877 link_set_supervision_props(l_ptr, msg_tol);
1878
1879 if (msg_linkprio(msg) > l_ptr->priority)
1880 l_ptr->priority = msg_linkprio(msg);
1881
1882 max_pkt_info = msg_max_pkt(msg);
1883 if (max_pkt_info) {
1884 if (max_pkt_info < l_ptr->max_pkt_target)
1885 l_ptr->max_pkt_target = max_pkt_info;
1886 if (l_ptr->max_pkt > l_ptr->max_pkt_target)
1887 l_ptr->max_pkt = l_ptr->max_pkt_target;
1888 } else {
1889 l_ptr->max_pkt = l_ptr->max_pkt_target;
1890 }
1891
1892 /* Synchronize broadcast link info, if not done previously */
1893 if (!tipc_node_is_up(l_ptr->owner)) {
1894 l_ptr->owner->bclink.last_sent =
1895 l_ptr->owner->bclink.last_in =
1896 msg_last_bcast(msg);
1897 l_ptr->owner->bclink.oos_state = 0;
1898 }
1899
1900 l_ptr->peer_session = msg_session(msg);
1901 l_ptr->peer_bearer_id = msg_bearer_id(msg);
1902
1903 if (msg_type(msg) == ACTIVATE_MSG)
1904 link_state_event(l_ptr, ACTIVATE_MSG);
1905 break;
1906 case STATE_MSG:
1907
1908 msg_tol = msg_link_tolerance(msg);
1909 if (msg_tol)
1910 link_set_supervision_props(l_ptr, msg_tol);
1911
1912 if (msg_linkprio(msg) &&
1913 (msg_linkprio(msg) != l_ptr->priority)) {
1914 pr_warn("%s<%s>, priority change %u->%u\n",
1915 link_rst_msg, l_ptr->name, l_ptr->priority,
1916 msg_linkprio(msg));
1917 l_ptr->priority = msg_linkprio(msg);
1918 tipc_link_reset(l_ptr); /* Enforce change to take effect */
1919 break;
1920 }
1921 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1922 l_ptr->stats.recv_states++;
1923 if (link_reset_unknown(l_ptr))
1924 break;
1925
1926 if (less_eq(mod(l_ptr->next_in_no), msg_next_sent(msg))) {
1927 rec_gap = mod(msg_next_sent(msg) -
1928 mod(l_ptr->next_in_no));
1929 }
1930
1931 max_pkt_ack = msg_max_pkt(msg);
1932 if (max_pkt_ack > l_ptr->max_pkt) {
1933 l_ptr->max_pkt = max_pkt_ack;
1934 l_ptr->max_pkt_probes = 0;
1935 }
1936
1937 max_pkt_ack = 0;
1938 if (msg_probe(msg)) {
1939 l_ptr->stats.recv_probes++;
1940 if (msg_size(msg) > sizeof(l_ptr->proto_msg))
1941 max_pkt_ack = msg_size(msg);
1942 }
1943
1944 /* Protocol message before retransmits, reduce loss risk */
1945 if (l_ptr->owner->bclink.recv_permitted)
1946 tipc_bclink_update_link_state(l_ptr->owner,
1947 msg_last_bcast(msg));
1948
1949 if (rec_gap || (msg_probe(msg))) {
1950 tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, rec_gap, 0,
1951 0, max_pkt_ack);
1952 }
1953 if (msg_seq_gap(msg)) {
1954 l_ptr->stats.recv_nacks++;
1955 tipc_link_retransmit(l_ptr, l_ptr->first_out,
1956 msg_seq_gap(msg));
1957 }
1958 break;
1959 }
1960exit:
1961 kfree_skb(buf);
1962}
1963
1964
1965/* tipc_link_tunnel_xmit(): Tunnel one packet via a link belonging to
1966 * a different bearer. Owner node is locked.
1967 */
1968static void tipc_link_tunnel_xmit(struct tipc_link *l_ptr,
1969 struct tipc_msg *tunnel_hdr,
1970 struct tipc_msg *msg,
1971 u32 selector)
1972{
1973 struct tipc_link *tunnel;
1974 struct sk_buff *buf;
1975 u32 length = msg_size(msg);
1976
1977 tunnel = l_ptr->owner->active_links[selector & 1];
1978 if (!tipc_link_is_up(tunnel)) {
1979 pr_warn("%stunnel link no longer available\n", link_co_err);
1980 return;
1981 }
1982 msg_set_size(tunnel_hdr, length + INT_H_SIZE);
1983 buf = tipc_buf_acquire(length + INT_H_SIZE);
1984 if (!buf) {
1985 pr_warn("%sunable to send tunnel msg\n", link_co_err);
1986 return;
1987 }
1988 skb_copy_to_linear_data(buf, tunnel_hdr, INT_H_SIZE);
1989 skb_copy_to_linear_data_offset(buf, INT_H_SIZE, msg, length);
1990 __tipc_link_xmit(tunnel, buf);
1991}
1992
1993
1994/* tipc_link_failover_send_queue(): A link has gone down, but a second
1995 * link is still active. We can do failover. Tunnel the failing link's
1996 * whole send queue via the remaining link. This way, we don't lose
1997 * any packets, and sequence order is preserved for subsequent traffic
1998 * sent over the remaining link. Owner node is locked.
1999 */
2000void tipc_link_failover_send_queue(struct tipc_link *l_ptr)
2001{
2002 u32 msgcount = l_ptr->out_queue_size;
2003 struct sk_buff *crs = l_ptr->first_out;
2004 struct tipc_link *tunnel = l_ptr->owner->active_links[0];
2005 struct tipc_msg tunnel_hdr;
2006 int split_bundles;
2007
2008 if (!tunnel)
2009 return;
2010
2011 tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
2012 ORIGINAL_MSG, INT_H_SIZE, l_ptr->addr);
2013 msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
2014 msg_set_msgcnt(&tunnel_hdr, msgcount);
2015
2016 if (!l_ptr->first_out) {
2017 struct sk_buff *buf;
2018
2019 buf = tipc_buf_acquire(INT_H_SIZE);
2020 if (buf) {
2021 skb_copy_to_linear_data(buf, &tunnel_hdr, INT_H_SIZE);
2022 msg_set_size(&tunnel_hdr, INT_H_SIZE);
2023 __tipc_link_xmit(tunnel, buf);
2024 } else {
2025 pr_warn("%sunable to send changeover msg\n",
2026 link_co_err);
2027 }
2028 return;
2029 }
2030
2031 split_bundles = (l_ptr->owner->active_links[0] !=
2032 l_ptr->owner->active_links[1]);
2033
2034 while (crs) {
2035 struct tipc_msg *msg = buf_msg(crs);
2036
2037 if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
2038 struct tipc_msg *m = msg_get_wrapped(msg);
2039 unchar *pos = (unchar *)m;
2040
2041 msgcount = msg_msgcnt(msg);
2042 while (msgcount--) {
2043 msg_set_seqno(m, msg_seqno(msg));
2044 tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, m,
2045 msg_link_selector(m));
2046 pos += align(msg_size(m));
2047 m = (struct tipc_msg *)pos;
2048 }
2049 } else {
2050 tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, msg,
2051 msg_link_selector(msg));
2052 }
2053 crs = crs->next;
2054 }
2055}
2056
2057/* tipc_link_dup_queue_xmit(): A second link has become active. Tunnel a
2058 * duplicate of the first link's send queue via the new link. This way, we
2059 * are guaranteed that currently queued packets from a socket are delivered
2060 * before future traffic from the same socket, even if this is using the
2061 * new link. The last arriving copy of each duplicate packet is dropped at
2062 * the receiving end by the regular protocol check, so packet cardinality
2063 * and sequence order is preserved per sender/receiver socket pair.
2064 * Owner node is locked.
2065 */
2066void tipc_link_dup_queue_xmit(struct tipc_link *l_ptr,
2067 struct tipc_link *tunnel)
2068{
2069 struct sk_buff *iter;
2070 struct tipc_msg tunnel_hdr;
2071
2072 tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
2073 DUPLICATE_MSG, INT_H_SIZE, l_ptr->addr);
2074 msg_set_msgcnt(&tunnel_hdr, l_ptr->out_queue_size);
2075 msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
2076 iter = l_ptr->first_out;
2077 while (iter) {
2078 struct sk_buff *outbuf;
2079 struct tipc_msg *msg = buf_msg(iter);
2080 u32 length = msg_size(msg);
2081
2082 if (msg_user(msg) == MSG_BUNDLER)
2083 msg_set_type(msg, CLOSED_MSG);
2084 msg_set_ack(msg, mod(l_ptr->next_in_no - 1)); /* Update */
2085 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
2086 msg_set_size(&tunnel_hdr, length + INT_H_SIZE);
2087 outbuf = tipc_buf_acquire(length + INT_H_SIZE);
2088 if (outbuf == NULL) {
2089 pr_warn("%sunable to send duplicate msg\n",
2090 link_co_err);
2091 return;
2092 }
2093 skb_copy_to_linear_data(outbuf, &tunnel_hdr, INT_H_SIZE);
2094 skb_copy_to_linear_data_offset(outbuf, INT_H_SIZE, iter->data,
2095 length);
2096 __tipc_link_xmit(tunnel, outbuf);
2097 if (!tipc_link_is_up(l_ptr))
2098 return;
2099 iter = iter->next;
2100 }
2101}
2102
2103/**
2104 * buf_extract - extracts embedded TIPC message from another message
2105 * @skb: encapsulating message buffer
2106 * @from_pos: offset to extract from
2107 *
2108 * Returns a new message buffer containing an embedded message. The
2109 * encapsulating message itself is left unchanged.
2110 */
2111static struct sk_buff *buf_extract(struct sk_buff *skb, u32 from_pos)
2112{
2113 struct tipc_msg *msg = (struct tipc_msg *)(skb->data + from_pos);
2114 u32 size = msg_size(msg);
2115 struct sk_buff *eb;
2116
2117 eb = tipc_buf_acquire(size);
2118 if (eb)
2119 skb_copy_to_linear_data(eb, msg, size);
2120 return eb;
2121}
2122
2123
2124
2125/* tipc_link_dup_rcv(): Receive a tunnelled DUPLICATE_MSG packet.
2126 * Owner node is locked.
2127 */
2128static void tipc_link_dup_rcv(struct tipc_link *l_ptr,
2129 struct sk_buff *t_buf)
2130{
2131 struct sk_buff *buf;
2132
2133 if (!tipc_link_is_up(l_ptr))
2134 return;
2135
2136 buf = buf_extract(t_buf, INT_H_SIZE);
2137 if (buf == NULL) {
2138 pr_warn("%sfailed to extract inner dup pkt\n", link_co_err);
2139 return;
2140 }
2141
2142 /* Add buffer to deferred queue, if applicable: */
2143 link_handle_out_of_seq_msg(l_ptr, buf);
2144}
2145
2146/* tipc_link_failover_rcv(): Receive a tunnelled ORIGINAL_MSG packet
2147 * Owner node is locked.
2148 */
2149static struct sk_buff *tipc_link_failover_rcv(struct tipc_link *l_ptr,
2150 struct sk_buff *t_buf)
2151{
2152 struct tipc_msg *t_msg = buf_msg(t_buf);
2153 struct sk_buff *buf = NULL;
2154 struct tipc_msg *msg;
2155
2156 if (tipc_link_is_up(l_ptr))
2157 tipc_link_reset(l_ptr);
2158
2159 /* First failover packet? */
2160 if (l_ptr->exp_msg_count == START_CHANGEOVER)
2161 l_ptr->exp_msg_count = msg_msgcnt(t_msg);
2162
2163 /* Should there be an inner packet? */
2164 if (l_ptr->exp_msg_count) {
2165 l_ptr->exp_msg_count--;
2166 buf = buf_extract(t_buf, INT_H_SIZE);
2167 if (buf == NULL) {
2168 pr_warn("%sno inner failover pkt\n", link_co_err);
2169 goto exit;
2170 }
2171 msg = buf_msg(buf);
2172
2173 if (less(msg_seqno(msg), l_ptr->reset_checkpoint)) {
2174 kfree_skb(buf);
2175 buf = NULL;
2176 goto exit;
2177 }
2178 if (msg_user(msg) == MSG_FRAGMENTER) {
2179 l_ptr->stats.recv_fragments++;
2180 tipc_link_frag_rcv(&l_ptr->reasm_head,
2181 &l_ptr->reasm_tail,
2182 &buf);
2183 }
2184 }
2185exit:
2186 if ((l_ptr->exp_msg_count == 0) && (l_ptr->flags & LINK_STOPPED)) {
2187 tipc_node_detach_link(l_ptr->owner, l_ptr);
2188 kfree(l_ptr);
2189 }
2190 return buf;
2191}
2192
2193/* tipc_link_tunnel_rcv(): Receive a tunnelled packet, sent
2194 * via other link as result of a failover (ORIGINAL_MSG) or
2195 * a new active link (DUPLICATE_MSG). Failover packets are
2196 * returned to the active link for delivery upwards.
2197 * Owner node is locked.
2198 */
2199static int tipc_link_tunnel_rcv(struct tipc_node *n_ptr,
2200 struct sk_buff **buf)
2201{
2202 struct sk_buff *t_buf = *buf;
2203 struct tipc_link *l_ptr;
2204 struct tipc_msg *t_msg = buf_msg(t_buf);
2205 u32 bearer_id = msg_bearer_id(t_msg);
2206
2207 *buf = NULL;
2208
2209 if (bearer_id >= MAX_BEARERS)
2210 goto exit;
2211
2212 l_ptr = n_ptr->links[bearer_id];
2213 if (!l_ptr)
2214 goto exit;
2215
2216 if (msg_type(t_msg) == DUPLICATE_MSG)
2217 tipc_link_dup_rcv(l_ptr, t_buf);
2218 else if (msg_type(t_msg) == ORIGINAL_MSG)
2219 *buf = tipc_link_failover_rcv(l_ptr, t_buf);
2220 else
2221 pr_warn("%sunknown tunnel pkt received\n", link_co_err);
2222exit:
2223 kfree_skb(t_buf);
2224 return *buf != NULL;
2225}
2226
2227/*
2228 * Bundler functionality:
2229 */
2230void tipc_link_bundle_rcv(struct sk_buff *buf)
2231{
2232 u32 msgcount = msg_msgcnt(buf_msg(buf));
2233 u32 pos = INT_H_SIZE;
2234 struct sk_buff *obuf;
2235
2236 while (msgcount--) {
2237 obuf = buf_extract(buf, pos);
2238 if (obuf == NULL) {
2239 pr_warn("Link unable to unbundle message(s)\n");
2240 break;
2241 }
2242 pos += align(msg_size(buf_msg(obuf)));
2243 tipc_net_route_msg(obuf);
2244 }
2245 kfree_skb(buf);
2246}
2247
2248/*
2249 * Fragmentation/defragmentation:
2250 */
2251
2252/*
2253 * tipc_link_frag_xmit: Entry for buffers needing fragmentation.
2254 * The buffer is complete, inclusive total message length.
2255 * Returns user data length.
2256 */
2257static int tipc_link_frag_xmit(struct tipc_link *l_ptr, struct sk_buff *buf)
2258{
2259 struct sk_buff *buf_chain = NULL;
2260 struct sk_buff *buf_chain_tail = (struct sk_buff *)&buf_chain;
2261 struct tipc_msg *inmsg = buf_msg(buf);
2262 struct tipc_msg fragm_hdr;
2263 u32 insize = msg_size(inmsg);
2264 u32 dsz = msg_data_sz(inmsg);
2265 unchar *crs = buf->data;
2266 u32 rest = insize;
2267 u32 pack_sz = l_ptr->max_pkt;
2268 u32 fragm_sz = pack_sz - INT_H_SIZE;
2269 u32 fragm_no = 0;
2270 u32 destaddr;
2271
2272 if (msg_short(inmsg))
2273 destaddr = l_ptr->addr;
2274 else
2275 destaddr = msg_destnode(inmsg);
2276
2277 /* Prepare reusable fragment header: */
2278 tipc_msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
2279 INT_H_SIZE, destaddr);
2280
2281 /* Chop up message: */
2282 while (rest > 0) {
2283 struct sk_buff *fragm;
2284
2285 if (rest <= fragm_sz) {
2286 fragm_sz = rest;
2287 msg_set_type(&fragm_hdr, LAST_FRAGMENT);
2288 }
2289 fragm = tipc_buf_acquire(fragm_sz + INT_H_SIZE);
2290 if (fragm == NULL) {
2291 kfree_skb(buf);
2292 kfree_skb_list(buf_chain);
2293 return -ENOMEM;
2294 }
2295 msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
2296 fragm_no++;
2297 msg_set_fragm_no(&fragm_hdr, fragm_no);
2298 skb_copy_to_linear_data(fragm, &fragm_hdr, INT_H_SIZE);
2299 skb_copy_to_linear_data_offset(fragm, INT_H_SIZE, crs,
2300 fragm_sz);
2301 buf_chain_tail->next = fragm;
2302 buf_chain_tail = fragm;
2303
2304 rest -= fragm_sz;
2305 crs += fragm_sz;
2306 msg_set_type(&fragm_hdr, FRAGMENT);
2307 }
2308 kfree_skb(buf);
2309
2310 /* Append chain of fragments to send queue & send them */
2311 l_ptr->long_msg_seq_no++;
2312 link_add_chain_to_outqueue(l_ptr, buf_chain, l_ptr->long_msg_seq_no);
2313 l_ptr->stats.sent_fragments += fragm_no;
2314 l_ptr->stats.sent_fragmented++;
2315 tipc_link_push_queue(l_ptr);
2316
2317 return dsz;
2318}
2319
2320/* tipc_link_frag_rcv(): Called with node lock on. Returns
2321 * the reassembled buffer if message is complete.
2322 */
2323int tipc_link_frag_rcv(struct sk_buff **head, struct sk_buff **tail,
2324 struct sk_buff **fbuf)
2325{
2326 struct sk_buff *frag = *fbuf;
2327 struct tipc_msg *msg = buf_msg(frag);
2328 u32 fragid = msg_type(msg);
2329 bool headstolen;
2330 int delta;
2331
2332 skb_pull(frag, msg_hdr_sz(msg));
2333 if (fragid == FIRST_FRAGMENT) {
2334 if (*head || skb_unclone(frag, GFP_ATOMIC))
2335 goto out_free;
2336 *head = frag;
2337 skb_frag_list_init(*head);
2338 *fbuf = NULL;
2339 return 0;
2340 } else if (*head &&
2341 skb_try_coalesce(*head, frag, &headstolen, &delta)) {
2342 kfree_skb_partial(frag, headstolen);
2343 } else {
2344 if (!*head)
2345 goto out_free;
2346 if (!skb_has_frag_list(*head))
2347 skb_shinfo(*head)->frag_list = frag;
2348 else
2349 (*tail)->next = frag;
2350 *tail = frag;
2351 (*head)->truesize += frag->truesize;
2352 }
2353 if (fragid == LAST_FRAGMENT) {
2354 *fbuf = *head;
2355 *tail = *head = NULL;
2356 return LINK_REASM_COMPLETE;
2357 }
2358 *fbuf = NULL;
2359 return 0;
2360out_free:
2361 pr_warn_ratelimited("Link unable to reassemble fragmented message\n");
2362 kfree_skb(*fbuf);
2363 *fbuf = NULL;
2364 return LINK_REASM_ERROR;
2365}
2366
2367static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance)
2368{
2369 if ((tolerance < TIPC_MIN_LINK_TOL) || (tolerance > TIPC_MAX_LINK_TOL))
2370 return;
2371
2372 l_ptr->tolerance = tolerance;
2373 l_ptr->continuity_interval =
2374 ((tolerance / 4) > 500) ? 500 : tolerance / 4;
2375 l_ptr->abort_limit = tolerance / (l_ptr->continuity_interval / 4);
2376}
2377
2378void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window)
2379{
2380 /* Data messages from this node, inclusive FIRST_FRAGM */
2381 l_ptr->queue_limit[TIPC_LOW_IMPORTANCE] = window;
2382 l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE] = (window / 3) * 4;
2383 l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE] = (window / 3) * 5;
2384 l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE] = (window / 3) * 6;
2385 /* Transiting data messages,inclusive FIRST_FRAGM */
2386 l_ptr->queue_limit[TIPC_LOW_IMPORTANCE + 4] = 300;
2387 l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE + 4] = 600;
2388 l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE + 4] = 900;
2389 l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE + 4] = 1200;
2390 l_ptr->queue_limit[CONN_MANAGER] = 1200;
2391 l_ptr->queue_limit[CHANGEOVER_PROTOCOL] = 2500;
2392 l_ptr->queue_limit[NAME_DISTRIBUTOR] = 3000;
2393 /* FRAGMENT and LAST_FRAGMENT packets */
2394 l_ptr->queue_limit[MSG_FRAGMENTER] = 4000;
2395}
2396
2397/* tipc_link_find_owner - locate owner node of link by link's name
2398 * @name: pointer to link name string
2399 * @bearer_id: pointer to index in 'node->links' array where the link was found.
2400 * Caller must hold 'tipc_net_lock' to ensure node and bearer are not deleted;
2401 * this also prevents link deletion.
2402 *
2403 * Returns pointer to node owning the link, or 0 if no matching link is found.
2404 */
2405static struct tipc_node *tipc_link_find_owner(const char *link_name,
2406 unsigned int *bearer_id)
2407{
2408 struct tipc_link *l_ptr;
2409 struct tipc_node *n_ptr;
2410 struct tipc_node *found_node = 0;
2411 int i;
2412
2413 *bearer_id = 0;
2414 rcu_read_lock();
2415 list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
2416 tipc_node_lock(n_ptr);
2417 for (i = 0; i < MAX_BEARERS; i++) {
2418 l_ptr = n_ptr->links[i];
2419 if (l_ptr && !strcmp(l_ptr->name, link_name)) {
2420 *bearer_id = i;
2421 found_node = n_ptr;
2422 break;
2423 }
2424 }
2425 tipc_node_unlock(n_ptr);
2426 if (found_node)
2427 break;
2428 }
2429 rcu_read_unlock();
2430
2431 return found_node;
2432}
2433
2434/**
2435 * link_value_is_valid -- validate proposed link tolerance/priority/window
2436 *
2437 * @cmd: value type (TIPC_CMD_SET_LINK_*)
2438 * @new_value: the new value
2439 *
2440 * Returns 1 if value is within range, 0 if not.
2441 */
2442static int link_value_is_valid(u16 cmd, u32 new_value)
2443{
2444 switch (cmd) {
2445 case TIPC_CMD_SET_LINK_TOL:
2446 return (new_value >= TIPC_MIN_LINK_TOL) &&
2447 (new_value <= TIPC_MAX_LINK_TOL);
2448 case TIPC_CMD_SET_LINK_PRI:
2449 return (new_value <= TIPC_MAX_LINK_PRI);
2450 case TIPC_CMD_SET_LINK_WINDOW:
2451 return (new_value >= TIPC_MIN_LINK_WIN) &&
2452 (new_value <= TIPC_MAX_LINK_WIN);
2453 }
2454 return 0;
2455}
2456
2457/**
2458 * link_cmd_set_value - change priority/tolerance/window for link/bearer/media
2459 * @name: ptr to link, bearer, or media name
2460 * @new_value: new value of link, bearer, or media setting
2461 * @cmd: which link, bearer, or media attribute to set (TIPC_CMD_SET_LINK_*)
2462 *
2463 * Caller must hold 'tipc_net_lock' to ensure link/bearer/media is not deleted.
2464 *
2465 * Returns 0 if value updated and negative value on error.
2466 */
2467static int link_cmd_set_value(const char *name, u32 new_value, u16 cmd)
2468{
2469 struct tipc_node *node;
2470 struct tipc_link *l_ptr;
2471 struct tipc_bearer *b_ptr;
2472 struct tipc_media *m_ptr;
2473 int bearer_id;
2474 int res = 0;
2475
2476 node = tipc_link_find_owner(name, &bearer_id);
2477 if (node) {
2478 tipc_node_lock(node);
2479 l_ptr = node->links[bearer_id];
2480
2481 if (l_ptr) {
2482 switch (cmd) {
2483 case TIPC_CMD_SET_LINK_TOL:
2484 link_set_supervision_props(l_ptr, new_value);
2485 tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0,
2486 new_value, 0, 0);
2487 break;
2488 case TIPC_CMD_SET_LINK_PRI:
2489 l_ptr->priority = new_value;
2490 tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0,
2491 0, new_value, 0);
2492 break;
2493 case TIPC_CMD_SET_LINK_WINDOW:
2494 tipc_link_set_queue_limits(l_ptr, new_value);
2495 break;
2496 default:
2497 res = -EINVAL;
2498 break;
2499 }
2500 }
2501 tipc_node_unlock(node);
2502 return res;
2503 }
2504
2505 b_ptr = tipc_bearer_find(name);
2506 if (b_ptr) {
2507 switch (cmd) {
2508 case TIPC_CMD_SET_LINK_TOL:
2509 b_ptr->tolerance = new_value;
2510 break;
2511 case TIPC_CMD_SET_LINK_PRI:
2512 b_ptr->priority = new_value;
2513 break;
2514 case TIPC_CMD_SET_LINK_WINDOW:
2515 b_ptr->window = new_value;
2516 break;
2517 default:
2518 res = -EINVAL;
2519 break;
2520 }
2521 return res;
2522 }
2523
2524 m_ptr = tipc_media_find(name);
2525 if (!m_ptr)
2526 return -ENODEV;
2527 switch (cmd) {
2528 case TIPC_CMD_SET_LINK_TOL:
2529 m_ptr->tolerance = new_value;
2530 break;
2531 case TIPC_CMD_SET_LINK_PRI:
2532 m_ptr->priority = new_value;
2533 break;
2534 case TIPC_CMD_SET_LINK_WINDOW:
2535 m_ptr->window = new_value;
2536 break;
2537 default:
2538 res = -EINVAL;
2539 break;
2540 }
2541 return res;
2542}
2543
2544struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space,
2545 u16 cmd)
2546{
2547 struct tipc_link_config *args;
2548 u32 new_value;
2549 int res;
2550
2551 if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_CONFIG))
2552 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2553
2554 args = (struct tipc_link_config *)TLV_DATA(req_tlv_area);
2555 new_value = ntohl(args->value);
2556
2557 if (!link_value_is_valid(cmd, new_value))
2558 return tipc_cfg_reply_error_string(
2559 "cannot change, value invalid");
2560
2561 if (!strcmp(args->name, tipc_bclink_name)) {
2562 if ((cmd == TIPC_CMD_SET_LINK_WINDOW) &&
2563 (tipc_bclink_set_queue_limits(new_value) == 0))
2564 return tipc_cfg_reply_none();
2565 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
2566 " (cannot change setting on broadcast link)");
2567 }
2568
2569 read_lock_bh(&tipc_net_lock);
2570 res = link_cmd_set_value(args->name, new_value, cmd);
2571 read_unlock_bh(&tipc_net_lock);
2572 if (res)
2573 return tipc_cfg_reply_error_string("cannot change link setting");
2574
2575 return tipc_cfg_reply_none();
2576}
2577
2578/**
2579 * link_reset_statistics - reset link statistics
2580 * @l_ptr: pointer to link
2581 */
2582static void link_reset_statistics(struct tipc_link *l_ptr)
2583{
2584 memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
2585 l_ptr->stats.sent_info = l_ptr->next_out_no;
2586 l_ptr->stats.recv_info = l_ptr->next_in_no;
2587}
2588
2589struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space)
2590{
2591 char *link_name;
2592 struct tipc_link *l_ptr;
2593 struct tipc_node *node;
2594 unsigned int bearer_id;
2595
2596 if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
2597 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2598
2599 link_name = (char *)TLV_DATA(req_tlv_area);
2600 if (!strcmp(link_name, tipc_bclink_name)) {
2601 if (tipc_bclink_reset_stats())
2602 return tipc_cfg_reply_error_string("link not found");
2603 return tipc_cfg_reply_none();
2604 }
2605 read_lock_bh(&tipc_net_lock);
2606 node = tipc_link_find_owner(link_name, &bearer_id);
2607 if (!node) {
2608 read_unlock_bh(&tipc_net_lock);
2609 return tipc_cfg_reply_error_string("link not found");
2610 }
2611 tipc_node_lock(node);
2612 l_ptr = node->links[bearer_id];
2613 if (!l_ptr) {
2614 tipc_node_unlock(node);
2615 read_unlock_bh(&tipc_net_lock);
2616 return tipc_cfg_reply_error_string("link not found");
2617 }
2618 link_reset_statistics(l_ptr);
2619 tipc_node_unlock(node);
2620 read_unlock_bh(&tipc_net_lock);
2621 return tipc_cfg_reply_none();
2622}
2623
2624/**
2625 * percent - convert count to a percentage of total (rounding up or down)
2626 */
2627static u32 percent(u32 count, u32 total)
2628{
2629 return (count * 100 + (total / 2)) / total;
2630}
2631
2632/**
2633 * tipc_link_stats - print link statistics
2634 * @name: link name
2635 * @buf: print buffer area
2636 * @buf_size: size of print buffer area
2637 *
2638 * Returns length of print buffer data string (or 0 if error)
2639 */
2640static int tipc_link_stats(const char *name, char *buf, const u32 buf_size)
2641{
2642 struct tipc_link *l;
2643 struct tipc_stats *s;
2644 struct tipc_node *node;
2645 char *status;
2646 u32 profile_total = 0;
2647 unsigned int bearer_id;
2648 int ret;
2649
2650 if (!strcmp(name, tipc_bclink_name))
2651 return tipc_bclink_stats(buf, buf_size);
2652
2653 read_lock_bh(&tipc_net_lock);
2654 node = tipc_link_find_owner(name, &bearer_id);
2655 if (!node) {
2656 read_unlock_bh(&tipc_net_lock);
2657 return 0;
2658 }
2659 tipc_node_lock(node);
2660
2661 l = node->links[bearer_id];
2662 if (!l) {
2663 tipc_node_unlock(node);
2664 read_unlock_bh(&tipc_net_lock);
2665 return 0;
2666 }
2667
2668 s = &l->stats;
2669
2670 if (tipc_link_is_active(l))
2671 status = "ACTIVE";
2672 else if (tipc_link_is_up(l))
2673 status = "STANDBY";
2674 else
2675 status = "DEFUNCT";
2676
2677 ret = tipc_snprintf(buf, buf_size, "Link <%s>\n"
2678 " %s MTU:%u Priority:%u Tolerance:%u ms"
2679 " Window:%u packets\n",
2680 l->name, status, l->max_pkt, l->priority,
2681 l->tolerance, l->queue_limit[0]);
2682
2683 ret += tipc_snprintf(buf + ret, buf_size - ret,
2684 " RX packets:%u fragments:%u/%u bundles:%u/%u\n",
2685 l->next_in_no - s->recv_info, s->recv_fragments,
2686 s->recv_fragmented, s->recv_bundles,
2687 s->recv_bundled);
2688
2689 ret += tipc_snprintf(buf + ret, buf_size - ret,
2690 " TX packets:%u fragments:%u/%u bundles:%u/%u\n",
2691 l->next_out_no - s->sent_info, s->sent_fragments,
2692 s->sent_fragmented, s->sent_bundles,
2693 s->sent_bundled);
2694
2695 profile_total = s->msg_length_counts;
2696 if (!profile_total)
2697 profile_total = 1;
2698
2699 ret += tipc_snprintf(buf + ret, buf_size - ret,
2700 " TX profile sample:%u packets average:%u octets\n"
2701 " 0-64:%u%% -256:%u%% -1024:%u%% -4096:%u%% "
2702 "-16384:%u%% -32768:%u%% -66000:%u%%\n",
2703 s->msg_length_counts,
2704 s->msg_lengths_total / profile_total,
2705 percent(s->msg_length_profile[0], profile_total),
2706 percent(s->msg_length_profile[1], profile_total),
2707 percent(s->msg_length_profile[2], profile_total),
2708 percent(s->msg_length_profile[3], profile_total),
2709 percent(s->msg_length_profile[4], profile_total),
2710 percent(s->msg_length_profile[5], profile_total),
2711 percent(s->msg_length_profile[6], profile_total));
2712
2713 ret += tipc_snprintf(buf + ret, buf_size - ret,
2714 " RX states:%u probes:%u naks:%u defs:%u"
2715 " dups:%u\n", s->recv_states, s->recv_probes,
2716 s->recv_nacks, s->deferred_recv, s->duplicates);
2717
2718 ret += tipc_snprintf(buf + ret, buf_size - ret,
2719 " TX states:%u probes:%u naks:%u acks:%u"
2720 " dups:%u\n", s->sent_states, s->sent_probes,
2721 s->sent_nacks, s->sent_acks, s->retransmitted);
2722
2723 ret += tipc_snprintf(buf + ret, buf_size - ret,
2724 " Congestion link:%u Send queue"
2725 " max:%u avg:%u\n", s->link_congs,
2726 s->max_queue_sz, s->queue_sz_counts ?
2727 (s->accu_queue_sz / s->queue_sz_counts) : 0);
2728
2729 tipc_node_unlock(node);
2730 read_unlock_bh(&tipc_net_lock);
2731 return ret;
2732}
2733
2734struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space)
2735{
2736 struct sk_buff *buf;
2737 struct tlv_desc *rep_tlv;
2738 int str_len;
2739 int pb_len;
2740 char *pb;
2741
2742 if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
2743 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2744
2745 buf = tipc_cfg_reply_alloc(TLV_SPACE(ULTRA_STRING_MAX_LEN));
2746 if (!buf)
2747 return NULL;
2748
2749 rep_tlv = (struct tlv_desc *)buf->data;
2750 pb = TLV_DATA(rep_tlv);
2751 pb_len = ULTRA_STRING_MAX_LEN;
2752 str_len = tipc_link_stats((char *)TLV_DATA(req_tlv_area),
2753 pb, pb_len);
2754 if (!str_len) {
2755 kfree_skb(buf);
2756 return tipc_cfg_reply_error_string("link not found");
2757 }
2758 str_len += 1; /* for "\0" */
2759 skb_put(buf, TLV_SPACE(str_len));
2760 TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
2761
2762 return buf;
2763}
2764
2765/**
2766 * tipc_link_get_max_pkt - get maximum packet size to use when sending to destination
2767 * @dest: network address of destination node
2768 * @selector: used to select from set of active links
2769 *
2770 * If no active link can be found, uses default maximum packet size.
2771 */
2772u32 tipc_link_get_max_pkt(u32 dest, u32 selector)
2773{
2774 struct tipc_node *n_ptr;
2775 struct tipc_link *l_ptr;
2776 u32 res = MAX_PKT_DEFAULT;
2777
2778 if (dest == tipc_own_addr)
2779 return MAX_MSG_SIZE;
2780
2781 read_lock_bh(&tipc_net_lock);
2782 n_ptr = tipc_node_find(dest);
2783 if (n_ptr) {
2784 tipc_node_lock(n_ptr);
2785 l_ptr = n_ptr->active_links[selector & 1];
2786 if (l_ptr)
2787 res = l_ptr->max_pkt;
2788 tipc_node_unlock(n_ptr);
2789 }
2790 read_unlock_bh(&tipc_net_lock);
2791 return res;
2792}
2793
2794static void link_print(struct tipc_link *l_ptr, const char *str)
2795{
2796 pr_info("%s Link %x<%s>:", str, l_ptr->addr, l_ptr->b_ptr->name);
2797
2798 if (link_working_unknown(l_ptr))
2799 pr_cont(":WU\n");
2800 else if (link_reset_reset(l_ptr))
2801 pr_cont(":RR\n");
2802 else if (link_reset_unknown(l_ptr))
2803 pr_cont(":RU\n");
2804 else if (link_working_working(l_ptr))
2805 pr_cont(":WW\n");
2806 else
2807 pr_cont("\n");
2808}