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Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[deliverable/linux.git] / net / tipc / link.c
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 "socket.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 */
49 static const char *link_co_err = "Link changeover error, ";
50 static const char *link_rst_msg = "Resetting link ";
51 static 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
78 static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
79 struct sk_buff *buf);
80 static void tipc_link_proto_rcv(struct tipc_link *l_ptr, struct sk_buff *buf);
81 static int tipc_link_tunnel_rcv(struct tipc_node *n_ptr,
82 struct sk_buff **buf);
83 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance);
84 static void link_state_event(struct tipc_link *l_ptr, u32 event);
85 static void link_reset_statistics(struct tipc_link *l_ptr);
86 static void link_print(struct tipc_link *l_ptr, const char *str);
87 static void tipc_link_sync_xmit(struct tipc_link *l);
88 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf);
89 static int tipc_link_input(struct tipc_link *l, struct sk_buff *buf);
90 static int tipc_link_prepare_input(struct tipc_link *l, struct sk_buff **buf);
91
92 /*
93 * Simple link routines
94 */
95 static unsigned int align(unsigned int i)
96 {
97 return (i + 3) & ~3u;
98 }
99
100 static void link_init_max_pkt(struct tipc_link *l_ptr)
101 {
102 struct tipc_bearer *b_ptr;
103 u32 max_pkt;
104
105 rcu_read_lock();
106 b_ptr = rcu_dereference_rtnl(bearer_list[l_ptr->bearer_id]);
107 if (!b_ptr) {
108 rcu_read_unlock();
109 return;
110 }
111 max_pkt = (b_ptr->mtu & ~3);
112 rcu_read_unlock();
113
114 if (max_pkt > MAX_MSG_SIZE)
115 max_pkt = MAX_MSG_SIZE;
116
117 l_ptr->max_pkt_target = max_pkt;
118 if (l_ptr->max_pkt_target < MAX_PKT_DEFAULT)
119 l_ptr->max_pkt = l_ptr->max_pkt_target;
120 else
121 l_ptr->max_pkt = MAX_PKT_DEFAULT;
122
123 l_ptr->max_pkt_probes = 0;
124 }
125
126 static u32 link_next_sent(struct tipc_link *l_ptr)
127 {
128 if (l_ptr->next_out)
129 return buf_seqno(l_ptr->next_out);
130 return mod(l_ptr->next_out_no);
131 }
132
133 static u32 link_last_sent(struct tipc_link *l_ptr)
134 {
135 return mod(link_next_sent(l_ptr) - 1);
136 }
137
138 /*
139 * Simple non-static link routines (i.e. referenced outside this file)
140 */
141 int tipc_link_is_up(struct tipc_link *l_ptr)
142 {
143 if (!l_ptr)
144 return 0;
145 return link_working_working(l_ptr) || link_working_unknown(l_ptr);
146 }
147
148 int tipc_link_is_active(struct tipc_link *l_ptr)
149 {
150 return (l_ptr->owner->active_links[0] == l_ptr) ||
151 (l_ptr->owner->active_links[1] == l_ptr);
152 }
153
154 /**
155 * link_timeout - handle expiration of link timer
156 * @l_ptr: pointer to link
157 */
158 static void link_timeout(struct tipc_link *l_ptr)
159 {
160 tipc_node_lock(l_ptr->owner);
161
162 /* update counters used in statistical profiling of send traffic */
163 l_ptr->stats.accu_queue_sz += l_ptr->out_queue_size;
164 l_ptr->stats.queue_sz_counts++;
165
166 if (l_ptr->first_out) {
167 struct tipc_msg *msg = buf_msg(l_ptr->first_out);
168 u32 length = msg_size(msg);
169
170 if ((msg_user(msg) == MSG_FRAGMENTER) &&
171 (msg_type(msg) == FIRST_FRAGMENT)) {
172 length = msg_size(msg_get_wrapped(msg));
173 }
174 if (length) {
175 l_ptr->stats.msg_lengths_total += length;
176 l_ptr->stats.msg_length_counts++;
177 if (length <= 64)
178 l_ptr->stats.msg_length_profile[0]++;
179 else if (length <= 256)
180 l_ptr->stats.msg_length_profile[1]++;
181 else if (length <= 1024)
182 l_ptr->stats.msg_length_profile[2]++;
183 else if (length <= 4096)
184 l_ptr->stats.msg_length_profile[3]++;
185 else if (length <= 16384)
186 l_ptr->stats.msg_length_profile[4]++;
187 else if (length <= 32768)
188 l_ptr->stats.msg_length_profile[5]++;
189 else
190 l_ptr->stats.msg_length_profile[6]++;
191 }
192 }
193
194 /* do all other link processing performed on a periodic basis */
195
196 link_state_event(l_ptr, TIMEOUT_EVT);
197
198 if (l_ptr->next_out)
199 tipc_link_push_queue(l_ptr);
200
201 tipc_node_unlock(l_ptr->owner);
202 }
203
204 static void link_set_timer(struct tipc_link *l_ptr, u32 time)
205 {
206 k_start_timer(&l_ptr->timer, time);
207 }
208
209 /**
210 * tipc_link_create - create a new link
211 * @n_ptr: pointer to associated node
212 * @b_ptr: pointer to associated bearer
213 * @media_addr: media address to use when sending messages over link
214 *
215 * Returns pointer to link.
216 */
217 struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
218 struct tipc_bearer *b_ptr,
219 const struct tipc_media_addr *media_addr)
220 {
221 struct tipc_link *l_ptr;
222 struct tipc_msg *msg;
223 char *if_name;
224 char addr_string[16];
225 u32 peer = n_ptr->addr;
226
227 if (n_ptr->link_cnt >= 2) {
228 tipc_addr_string_fill(addr_string, n_ptr->addr);
229 pr_err("Attempt to establish third link to %s\n", addr_string);
230 return NULL;
231 }
232
233 if (n_ptr->links[b_ptr->identity]) {
234 tipc_addr_string_fill(addr_string, n_ptr->addr);
235 pr_err("Attempt to establish second link on <%s> to %s\n",
236 b_ptr->name, addr_string);
237 return NULL;
238 }
239
240 l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
241 if (!l_ptr) {
242 pr_warn("Link creation failed, no memory\n");
243 return NULL;
244 }
245
246 l_ptr->addr = peer;
247 if_name = strchr(b_ptr->name, ':') + 1;
248 sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
249 tipc_zone(tipc_own_addr), tipc_cluster(tipc_own_addr),
250 tipc_node(tipc_own_addr),
251 if_name,
252 tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
253 /* note: peer i/f name is updated by reset/activate message */
254 memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
255 l_ptr->owner = n_ptr;
256 l_ptr->checkpoint = 1;
257 l_ptr->peer_session = INVALID_SESSION;
258 l_ptr->bearer_id = b_ptr->identity;
259 link_set_supervision_props(l_ptr, b_ptr->tolerance);
260 l_ptr->state = RESET_UNKNOWN;
261
262 l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
263 msg = l_ptr->pmsg;
264 tipc_msg_init(msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, l_ptr->addr);
265 msg_set_size(msg, sizeof(l_ptr->proto_msg));
266 msg_set_session(msg, (tipc_random & 0xffff));
267 msg_set_bearer_id(msg, b_ptr->identity);
268 strcpy((char *)msg_data(msg), if_name);
269
270 l_ptr->priority = b_ptr->priority;
271 tipc_link_set_queue_limits(l_ptr, b_ptr->window);
272
273 l_ptr->net_plane = b_ptr->net_plane;
274 link_init_max_pkt(l_ptr);
275
276 l_ptr->next_out_no = 1;
277 __skb_queue_head_init(&l_ptr->waiting_sks);
278
279 link_reset_statistics(l_ptr);
280
281 tipc_node_attach_link(n_ptr, l_ptr);
282
283 k_init_timer(&l_ptr->timer, (Handler)link_timeout,
284 (unsigned long)l_ptr);
285
286 link_state_event(l_ptr, STARTING_EVT);
287
288 return l_ptr;
289 }
290
291 void tipc_link_delete_list(unsigned int bearer_id, bool shutting_down)
292 {
293 struct tipc_link *l_ptr;
294 struct tipc_node *n_ptr;
295
296 rcu_read_lock();
297 list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
298 tipc_node_lock(n_ptr);
299 l_ptr = n_ptr->links[bearer_id];
300 if (l_ptr) {
301 tipc_link_reset(l_ptr);
302 if (shutting_down || !tipc_node_is_up(n_ptr)) {
303 tipc_node_detach_link(l_ptr->owner, l_ptr);
304 tipc_link_reset_fragments(l_ptr);
305 tipc_node_unlock(n_ptr);
306
307 /* Nobody else can access this link now: */
308 del_timer_sync(&l_ptr->timer);
309 kfree(l_ptr);
310 } else {
311 /* Detach/delete when failover is finished: */
312 l_ptr->flags |= LINK_STOPPED;
313 tipc_node_unlock(n_ptr);
314 del_timer_sync(&l_ptr->timer);
315 }
316 continue;
317 }
318 tipc_node_unlock(n_ptr);
319 }
320 rcu_read_unlock();
321 }
322
323 /**
324 * link_schedule_user - schedule user for wakeup after congestion
325 * @link: congested link
326 * @oport: sending port
327 * @chain_sz: size of buffer chain that was attempted sent
328 * @imp: importance of message attempted sent
329 * Create pseudo msg to send back to user when congestion abates
330 */
331 static bool link_schedule_user(struct tipc_link *link, u32 oport,
332 uint chain_sz, uint imp)
333 {
334 struct sk_buff *buf;
335
336 buf = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0, tipc_own_addr,
337 tipc_own_addr, oport, 0, 0);
338 if (!buf)
339 return false;
340 TIPC_SKB_CB(buf)->chain_sz = chain_sz;
341 TIPC_SKB_CB(buf)->chain_imp = imp;
342 __skb_queue_tail(&link->waiting_sks, buf);
343 link->stats.link_congs++;
344 return true;
345 }
346
347 /**
348 * link_prepare_wakeup - prepare users for wakeup after congestion
349 * @link: congested link
350 * Move a number of waiting users, as permitted by available space in
351 * the send queue, from link wait queue to node wait queue for wakeup
352 */
353 static void link_prepare_wakeup(struct tipc_link *link)
354 {
355 struct sk_buff_head *wq = &link->waiting_sks;
356 struct sk_buff *buf;
357 uint pend_qsz = link->out_queue_size;
358
359 for (buf = skb_peek(wq); buf; buf = skb_peek(wq)) {
360 if (pend_qsz >= link->queue_limit[TIPC_SKB_CB(buf)->chain_imp])
361 break;
362 pend_qsz += TIPC_SKB_CB(buf)->chain_sz;
363 __skb_queue_tail(&link->owner->waiting_sks, __skb_dequeue(wq));
364 }
365 }
366
367 /**
368 * link_release_outqueue - purge link's outbound message queue
369 * @l_ptr: pointer to link
370 */
371 static void link_release_outqueue(struct tipc_link *l_ptr)
372 {
373 kfree_skb_list(l_ptr->first_out);
374 l_ptr->first_out = NULL;
375 l_ptr->out_queue_size = 0;
376 }
377
378 /**
379 * tipc_link_reset_fragments - purge link's inbound message fragments queue
380 * @l_ptr: pointer to link
381 */
382 void tipc_link_reset_fragments(struct tipc_link *l_ptr)
383 {
384 kfree_skb(l_ptr->reasm_buf);
385 l_ptr->reasm_buf = NULL;
386 }
387
388 /**
389 * tipc_link_purge_queues - purge all pkt queues associated with link
390 * @l_ptr: pointer to link
391 */
392 void tipc_link_purge_queues(struct tipc_link *l_ptr)
393 {
394 kfree_skb_list(l_ptr->oldest_deferred_in);
395 kfree_skb_list(l_ptr->first_out);
396 tipc_link_reset_fragments(l_ptr);
397 kfree_skb(l_ptr->proto_msg_queue);
398 l_ptr->proto_msg_queue = NULL;
399 }
400
401 void tipc_link_reset(struct tipc_link *l_ptr)
402 {
403 u32 prev_state = l_ptr->state;
404 u32 checkpoint = l_ptr->next_in_no;
405 int was_active_link = tipc_link_is_active(l_ptr);
406 struct tipc_node *owner = l_ptr->owner;
407
408 msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
409
410 /* Link is down, accept any session */
411 l_ptr->peer_session = INVALID_SESSION;
412
413 /* Prepare for max packet size negotiation */
414 link_init_max_pkt(l_ptr);
415
416 l_ptr->state = RESET_UNKNOWN;
417
418 if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
419 return;
420
421 tipc_node_link_down(l_ptr->owner, l_ptr);
422 tipc_bearer_remove_dest(l_ptr->bearer_id, l_ptr->addr);
423
424 if (was_active_link && tipc_node_active_links(l_ptr->owner)) {
425 l_ptr->reset_checkpoint = checkpoint;
426 l_ptr->exp_msg_count = START_CHANGEOVER;
427 }
428
429 /* Clean up all queues: */
430 link_release_outqueue(l_ptr);
431 kfree_skb(l_ptr->proto_msg_queue);
432 l_ptr->proto_msg_queue = NULL;
433 kfree_skb_list(l_ptr->oldest_deferred_in);
434 if (!skb_queue_empty(&l_ptr->waiting_sks)) {
435 skb_queue_splice_init(&l_ptr->waiting_sks, &owner->waiting_sks);
436 owner->action_flags |= TIPC_WAKEUP_USERS;
437 }
438 l_ptr->retransm_queue_head = 0;
439 l_ptr->retransm_queue_size = 0;
440 l_ptr->last_out = NULL;
441 l_ptr->first_out = NULL;
442 l_ptr->next_out = NULL;
443 l_ptr->unacked_window = 0;
444 l_ptr->checkpoint = 1;
445 l_ptr->next_out_no = 1;
446 l_ptr->deferred_inqueue_sz = 0;
447 l_ptr->oldest_deferred_in = NULL;
448 l_ptr->newest_deferred_in = NULL;
449 l_ptr->fsm_msg_cnt = 0;
450 l_ptr->stale_count = 0;
451 link_reset_statistics(l_ptr);
452 }
453
454 void tipc_link_reset_list(unsigned int bearer_id)
455 {
456 struct tipc_link *l_ptr;
457 struct tipc_node *n_ptr;
458
459 rcu_read_lock();
460 list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
461 tipc_node_lock(n_ptr);
462 l_ptr = n_ptr->links[bearer_id];
463 if (l_ptr)
464 tipc_link_reset(l_ptr);
465 tipc_node_unlock(n_ptr);
466 }
467 rcu_read_unlock();
468 }
469
470 static void link_activate(struct tipc_link *l_ptr)
471 {
472 l_ptr->next_in_no = l_ptr->stats.recv_info = 1;
473 tipc_node_link_up(l_ptr->owner, l_ptr);
474 tipc_bearer_add_dest(l_ptr->bearer_id, l_ptr->addr);
475 }
476
477 /**
478 * link_state_event - link finite state machine
479 * @l_ptr: pointer to link
480 * @event: state machine event to process
481 */
482 static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
483 {
484 struct tipc_link *other;
485 u32 cont_intv = l_ptr->continuity_interval;
486
487 if (l_ptr->flags & LINK_STOPPED)
488 return;
489
490 if (!(l_ptr->flags & LINK_STARTED) && (event != STARTING_EVT))
491 return; /* Not yet. */
492
493 /* Check whether changeover is going on */
494 if (l_ptr->exp_msg_count) {
495 if (event == TIMEOUT_EVT)
496 link_set_timer(l_ptr, cont_intv);
497 return;
498 }
499
500 switch (l_ptr->state) {
501 case WORKING_WORKING:
502 switch (event) {
503 case TRAFFIC_MSG_EVT:
504 case ACTIVATE_MSG:
505 break;
506 case TIMEOUT_EVT:
507 if (l_ptr->next_in_no != l_ptr->checkpoint) {
508 l_ptr->checkpoint = l_ptr->next_in_no;
509 if (tipc_bclink_acks_missing(l_ptr->owner)) {
510 tipc_link_proto_xmit(l_ptr, STATE_MSG,
511 0, 0, 0, 0, 0);
512 l_ptr->fsm_msg_cnt++;
513 } else if (l_ptr->max_pkt < l_ptr->max_pkt_target) {
514 tipc_link_proto_xmit(l_ptr, STATE_MSG,
515 1, 0, 0, 0, 0);
516 l_ptr->fsm_msg_cnt++;
517 }
518 link_set_timer(l_ptr, cont_intv);
519 break;
520 }
521 l_ptr->state = WORKING_UNKNOWN;
522 l_ptr->fsm_msg_cnt = 0;
523 tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
524 l_ptr->fsm_msg_cnt++;
525 link_set_timer(l_ptr, cont_intv / 4);
526 break;
527 case RESET_MSG:
528 pr_info("%s<%s>, requested by peer\n", link_rst_msg,
529 l_ptr->name);
530 tipc_link_reset(l_ptr);
531 l_ptr->state = RESET_RESET;
532 l_ptr->fsm_msg_cnt = 0;
533 tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
534 0, 0, 0, 0, 0);
535 l_ptr->fsm_msg_cnt++;
536 link_set_timer(l_ptr, cont_intv);
537 break;
538 default:
539 pr_err("%s%u in WW state\n", link_unk_evt, event);
540 }
541 break;
542 case WORKING_UNKNOWN:
543 switch (event) {
544 case TRAFFIC_MSG_EVT:
545 case ACTIVATE_MSG:
546 l_ptr->state = WORKING_WORKING;
547 l_ptr->fsm_msg_cnt = 0;
548 link_set_timer(l_ptr, cont_intv);
549 break;
550 case RESET_MSG:
551 pr_info("%s<%s>, requested by peer while probing\n",
552 link_rst_msg, l_ptr->name);
553 tipc_link_reset(l_ptr);
554 l_ptr->state = RESET_RESET;
555 l_ptr->fsm_msg_cnt = 0;
556 tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
557 0, 0, 0, 0, 0);
558 l_ptr->fsm_msg_cnt++;
559 link_set_timer(l_ptr, cont_intv);
560 break;
561 case TIMEOUT_EVT:
562 if (l_ptr->next_in_no != l_ptr->checkpoint) {
563 l_ptr->state = WORKING_WORKING;
564 l_ptr->fsm_msg_cnt = 0;
565 l_ptr->checkpoint = l_ptr->next_in_no;
566 if (tipc_bclink_acks_missing(l_ptr->owner)) {
567 tipc_link_proto_xmit(l_ptr, STATE_MSG,
568 0, 0, 0, 0, 0);
569 l_ptr->fsm_msg_cnt++;
570 }
571 link_set_timer(l_ptr, cont_intv);
572 } else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) {
573 tipc_link_proto_xmit(l_ptr, STATE_MSG,
574 1, 0, 0, 0, 0);
575 l_ptr->fsm_msg_cnt++;
576 link_set_timer(l_ptr, cont_intv / 4);
577 } else { /* Link has failed */
578 pr_warn("%s<%s>, peer not responding\n",
579 link_rst_msg, l_ptr->name);
580 tipc_link_reset(l_ptr);
581 l_ptr->state = RESET_UNKNOWN;
582 l_ptr->fsm_msg_cnt = 0;
583 tipc_link_proto_xmit(l_ptr, RESET_MSG,
584 0, 0, 0, 0, 0);
585 l_ptr->fsm_msg_cnt++;
586 link_set_timer(l_ptr, cont_intv);
587 }
588 break;
589 default:
590 pr_err("%s%u in WU state\n", link_unk_evt, event);
591 }
592 break;
593 case RESET_UNKNOWN:
594 switch (event) {
595 case TRAFFIC_MSG_EVT:
596 break;
597 case ACTIVATE_MSG:
598 other = l_ptr->owner->active_links[0];
599 if (other && link_working_unknown(other))
600 break;
601 l_ptr->state = WORKING_WORKING;
602 l_ptr->fsm_msg_cnt = 0;
603 link_activate(l_ptr);
604 tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
605 l_ptr->fsm_msg_cnt++;
606 if (l_ptr->owner->working_links == 1)
607 tipc_link_sync_xmit(l_ptr);
608 link_set_timer(l_ptr, cont_intv);
609 break;
610 case RESET_MSG:
611 l_ptr->state = RESET_RESET;
612 l_ptr->fsm_msg_cnt = 0;
613 tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
614 1, 0, 0, 0, 0);
615 l_ptr->fsm_msg_cnt++;
616 link_set_timer(l_ptr, cont_intv);
617 break;
618 case STARTING_EVT:
619 l_ptr->flags |= LINK_STARTED;
620 /* fall through */
621 case TIMEOUT_EVT:
622 tipc_link_proto_xmit(l_ptr, RESET_MSG, 0, 0, 0, 0, 0);
623 l_ptr->fsm_msg_cnt++;
624 link_set_timer(l_ptr, cont_intv);
625 break;
626 default:
627 pr_err("%s%u in RU state\n", link_unk_evt, event);
628 }
629 break;
630 case RESET_RESET:
631 switch (event) {
632 case TRAFFIC_MSG_EVT:
633 case ACTIVATE_MSG:
634 other = l_ptr->owner->active_links[0];
635 if (other && link_working_unknown(other))
636 break;
637 l_ptr->state = WORKING_WORKING;
638 l_ptr->fsm_msg_cnt = 0;
639 link_activate(l_ptr);
640 tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
641 l_ptr->fsm_msg_cnt++;
642 if (l_ptr->owner->working_links == 1)
643 tipc_link_sync_xmit(l_ptr);
644 link_set_timer(l_ptr, cont_intv);
645 break;
646 case RESET_MSG:
647 break;
648 case TIMEOUT_EVT:
649 tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
650 0, 0, 0, 0, 0);
651 l_ptr->fsm_msg_cnt++;
652 link_set_timer(l_ptr, cont_intv);
653 break;
654 default:
655 pr_err("%s%u in RR state\n", link_unk_evt, event);
656 }
657 break;
658 default:
659 pr_err("Unknown link state %u/%u\n", l_ptr->state, event);
660 }
661 }
662
663 /* tipc_link_cong: determine return value and how to treat the
664 * sent buffer during link congestion.
665 * - For plain, errorless user data messages we keep the buffer and
666 * return -ELINKONG.
667 * - For all other messages we discard the buffer and return -EHOSTUNREACH
668 * - For TIPC internal messages we also reset the link
669 */
670 static int tipc_link_cong(struct tipc_link *link, struct sk_buff *buf)
671 {
672 struct tipc_msg *msg = buf_msg(buf);
673 uint imp = tipc_msg_tot_importance(msg);
674 u32 oport = msg_tot_origport(msg);
675
676 if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
677 pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
678 tipc_link_reset(link);
679 goto drop;
680 }
681 if (unlikely(msg_errcode(msg)))
682 goto drop;
683 if (unlikely(msg_reroute_cnt(msg)))
684 goto drop;
685 if (TIPC_SKB_CB(buf)->wakeup_pending)
686 return -ELINKCONG;
687 if (link_schedule_user(link, oport, TIPC_SKB_CB(buf)->chain_sz, imp))
688 return -ELINKCONG;
689 drop:
690 kfree_skb_list(buf);
691 return -EHOSTUNREACH;
692 }
693
694 /**
695 * __tipc_link_xmit(): same as tipc_link_xmit, but destlink is known & locked
696 * @link: link to use
697 * @buf: chain of buffers containing message
698 * Consumes the buffer chain, except when returning -ELINKCONG
699 * Returns 0 if success, otherwise errno: -ELINKCONG, -EMSGSIZE (plain socket
700 * user data messages) or -EHOSTUNREACH (all other messages/senders)
701 * Only the socket functions tipc_send_stream() and tipc_send_packet() need
702 * to act on the return value, since they may need to do more send attempts.
703 */
704 int __tipc_link_xmit(struct tipc_link *link, struct sk_buff *buf)
705 {
706 struct tipc_msg *msg = buf_msg(buf);
707 uint psz = msg_size(msg);
708 uint qsz = link->out_queue_size;
709 uint sndlim = link->queue_limit[0];
710 uint imp = tipc_msg_tot_importance(msg);
711 uint mtu = link->max_pkt;
712 uint ack = mod(link->next_in_no - 1);
713 uint seqno = link->next_out_no;
714 uint bc_last_in = link->owner->bclink.last_in;
715 struct tipc_media_addr *addr = &link->media_addr;
716 struct sk_buff *next = buf->next;
717
718 /* Match queue limits against msg importance: */
719 if (unlikely(qsz >= link->queue_limit[imp]))
720 return tipc_link_cong(link, buf);
721
722 /* Has valid packet limit been used ? */
723 if (unlikely(psz > mtu)) {
724 kfree_skb_list(buf);
725 return -EMSGSIZE;
726 }
727
728 /* Prepare each packet for sending, and add to outqueue: */
729 while (buf) {
730 next = buf->next;
731 msg = buf_msg(buf);
732 msg_set_word(msg, 2, ((ack << 16) | mod(seqno)));
733 msg_set_bcast_ack(msg, bc_last_in);
734
735 if (!link->first_out) {
736 link->first_out = buf;
737 } else if (qsz < sndlim) {
738 link->last_out->next = buf;
739 } else if (tipc_msg_bundle(link->last_out, buf, mtu)) {
740 link->stats.sent_bundled++;
741 buf = next;
742 next = buf->next;
743 continue;
744 } else if (tipc_msg_make_bundle(&buf, mtu, link->addr)) {
745 link->stats.sent_bundled++;
746 link->stats.sent_bundles++;
747 link->last_out->next = buf;
748 if (!link->next_out)
749 link->next_out = buf;
750 } else {
751 link->last_out->next = buf;
752 if (!link->next_out)
753 link->next_out = buf;
754 }
755
756 /* Send packet if possible: */
757 if (likely(++qsz <= sndlim)) {
758 tipc_bearer_send(link->bearer_id, buf, addr);
759 link->next_out = next;
760 link->unacked_window = 0;
761 }
762 seqno++;
763 link->last_out = buf;
764 buf = next;
765 }
766 link->next_out_no = seqno;
767 link->out_queue_size = qsz;
768 return 0;
769 }
770
771 /**
772 * tipc_link_xmit() is the general link level function for message sending
773 * @buf: chain of buffers containing message
774 * @dsz: amount of user data to be sent
775 * @dnode: address of destination node
776 * @selector: a number used for deterministic link selection
777 * Consumes the buffer chain, except when returning -ELINKCONG
778 * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
779 */
780 int tipc_link_xmit(struct sk_buff *buf, u32 dnode, u32 selector)
781 {
782 struct tipc_link *link = NULL;
783 struct tipc_node *node;
784 int rc = -EHOSTUNREACH;
785
786 node = tipc_node_find(dnode);
787 if (node) {
788 tipc_node_lock(node);
789 link = node->active_links[selector & 1];
790 if (link)
791 rc = __tipc_link_xmit(link, buf);
792 tipc_node_unlock(node);
793 }
794
795 if (link)
796 return rc;
797
798 if (likely(in_own_node(dnode)))
799 return tipc_sk_rcv(buf);
800
801 kfree_skb_list(buf);
802 return rc;
803 }
804
805 /*
806 * tipc_link_sync_xmit - synchronize broadcast link endpoints.
807 *
808 * Give a newly added peer node the sequence number where it should
809 * start receiving and acking broadcast packets.
810 *
811 * Called with node locked
812 */
813 static void tipc_link_sync_xmit(struct tipc_link *link)
814 {
815 struct sk_buff *buf;
816 struct tipc_msg *msg;
817
818 buf = tipc_buf_acquire(INT_H_SIZE);
819 if (!buf)
820 return;
821
822 msg = buf_msg(buf);
823 tipc_msg_init(msg, BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE, link->addr);
824 msg_set_last_bcast(msg, link->owner->bclink.acked);
825 __tipc_link_xmit(link, buf);
826 }
827
828 /*
829 * tipc_link_sync_rcv - synchronize broadcast link endpoints.
830 * Receive the sequence number where we should start receiving and
831 * acking broadcast packets from a newly added peer node, and open
832 * up for reception of such packets.
833 *
834 * Called with node locked
835 */
836 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf)
837 {
838 struct tipc_msg *msg = buf_msg(buf);
839
840 n->bclink.last_sent = n->bclink.last_in = msg_last_bcast(msg);
841 n->bclink.recv_permitted = true;
842 kfree_skb(buf);
843 }
844
845 /*
846 * tipc_link_push_packet: Push one unsent packet to the media
847 */
848 static u32 tipc_link_push_packet(struct tipc_link *l_ptr)
849 {
850 struct sk_buff *buf = l_ptr->first_out;
851 u32 r_q_size = l_ptr->retransm_queue_size;
852 u32 r_q_head = l_ptr->retransm_queue_head;
853
854 /* Step to position where retransmission failed, if any, */
855 /* consider that buffers may have been released in meantime */
856 if (r_q_size && buf) {
857 u32 last = lesser(mod(r_q_head + r_q_size),
858 link_last_sent(l_ptr));
859 u32 first = buf_seqno(buf);
860
861 while (buf && less(first, r_q_head)) {
862 first = mod(first + 1);
863 buf = buf->next;
864 }
865 l_ptr->retransm_queue_head = r_q_head = first;
866 l_ptr->retransm_queue_size = r_q_size = mod(last - first);
867 }
868
869 /* Continue retransmission now, if there is anything: */
870 if (r_q_size && buf) {
871 msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
872 msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
873 tipc_bearer_send(l_ptr->bearer_id, buf, &l_ptr->media_addr);
874 l_ptr->retransm_queue_head = mod(++r_q_head);
875 l_ptr->retransm_queue_size = --r_q_size;
876 l_ptr->stats.retransmitted++;
877 return 0;
878 }
879
880 /* Send deferred protocol message, if any: */
881 buf = l_ptr->proto_msg_queue;
882 if (buf) {
883 msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
884 msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
885 tipc_bearer_send(l_ptr->bearer_id, buf, &l_ptr->media_addr);
886 l_ptr->unacked_window = 0;
887 kfree_skb(buf);
888 l_ptr->proto_msg_queue = NULL;
889 return 0;
890 }
891
892 /* Send one deferred data message, if send window not full: */
893 buf = l_ptr->next_out;
894 if (buf) {
895 struct tipc_msg *msg = buf_msg(buf);
896 u32 next = msg_seqno(msg);
897 u32 first = buf_seqno(l_ptr->first_out);
898
899 if (mod(next - first) < l_ptr->queue_limit[0]) {
900 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
901 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
902 tipc_bearer_send(l_ptr->bearer_id, buf,
903 &l_ptr->media_addr);
904 if (msg_user(msg) == MSG_BUNDLER)
905 msg_set_type(msg, BUNDLE_CLOSED);
906 l_ptr->next_out = buf->next;
907 return 0;
908 }
909 }
910 return 1;
911 }
912
913 /*
914 * push_queue(): push out the unsent messages of a link where
915 * congestion has abated. Node is locked
916 */
917 void tipc_link_push_queue(struct tipc_link *l_ptr)
918 {
919 u32 res;
920
921 do {
922 res = tipc_link_push_packet(l_ptr);
923 } while (!res);
924 }
925
926 void tipc_link_reset_all(struct tipc_node *node)
927 {
928 char addr_string[16];
929 u32 i;
930
931 tipc_node_lock(node);
932
933 pr_warn("Resetting all links to %s\n",
934 tipc_addr_string_fill(addr_string, node->addr));
935
936 for (i = 0; i < MAX_BEARERS; i++) {
937 if (node->links[i]) {
938 link_print(node->links[i], "Resetting link\n");
939 tipc_link_reset(node->links[i]);
940 }
941 }
942
943 tipc_node_unlock(node);
944 }
945
946 static void link_retransmit_failure(struct tipc_link *l_ptr,
947 struct sk_buff *buf)
948 {
949 struct tipc_msg *msg = buf_msg(buf);
950
951 pr_warn("Retransmission failure on link <%s>\n", l_ptr->name);
952
953 if (l_ptr->addr) {
954 /* Handle failure on standard link */
955 link_print(l_ptr, "Resetting link\n");
956 tipc_link_reset(l_ptr);
957
958 } else {
959 /* Handle failure on broadcast link */
960 struct tipc_node *n_ptr;
961 char addr_string[16];
962
963 pr_info("Msg seq number: %u, ", msg_seqno(msg));
964 pr_cont("Outstanding acks: %lu\n",
965 (unsigned long) TIPC_SKB_CB(buf)->handle);
966
967 n_ptr = tipc_bclink_retransmit_to();
968 tipc_node_lock(n_ptr);
969
970 tipc_addr_string_fill(addr_string, n_ptr->addr);
971 pr_info("Broadcast link info for %s\n", addr_string);
972 pr_info("Reception permitted: %d, Acked: %u\n",
973 n_ptr->bclink.recv_permitted,
974 n_ptr->bclink.acked);
975 pr_info("Last in: %u, Oos state: %u, Last sent: %u\n",
976 n_ptr->bclink.last_in,
977 n_ptr->bclink.oos_state,
978 n_ptr->bclink.last_sent);
979
980 tipc_node_unlock(n_ptr);
981
982 tipc_bclink_set_flags(TIPC_BCLINK_RESET);
983 l_ptr->stale_count = 0;
984 }
985 }
986
987 void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *buf,
988 u32 retransmits)
989 {
990 struct tipc_msg *msg;
991
992 if (!buf)
993 return;
994
995 msg = buf_msg(buf);
996
997 /* Detect repeated retransmit failures */
998 if (l_ptr->last_retransmitted == msg_seqno(msg)) {
999 if (++l_ptr->stale_count > 100) {
1000 link_retransmit_failure(l_ptr, buf);
1001 return;
1002 }
1003 } else {
1004 l_ptr->last_retransmitted = msg_seqno(msg);
1005 l_ptr->stale_count = 1;
1006 }
1007
1008 while (retransmits && (buf != l_ptr->next_out) && buf) {
1009 msg = buf_msg(buf);
1010 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1011 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1012 tipc_bearer_send(l_ptr->bearer_id, buf, &l_ptr->media_addr);
1013 buf = buf->next;
1014 retransmits--;
1015 l_ptr->stats.retransmitted++;
1016 }
1017
1018 l_ptr->retransm_queue_head = l_ptr->retransm_queue_size = 0;
1019 }
1020
1021 /**
1022 * link_insert_deferred_queue - insert deferred messages back into receive chain
1023 */
1024 static struct sk_buff *link_insert_deferred_queue(struct tipc_link *l_ptr,
1025 struct sk_buff *buf)
1026 {
1027 u32 seq_no;
1028
1029 if (l_ptr->oldest_deferred_in == NULL)
1030 return buf;
1031
1032 seq_no = buf_seqno(l_ptr->oldest_deferred_in);
1033 if (seq_no == mod(l_ptr->next_in_no)) {
1034 l_ptr->newest_deferred_in->next = buf;
1035 buf = l_ptr->oldest_deferred_in;
1036 l_ptr->oldest_deferred_in = NULL;
1037 l_ptr->deferred_inqueue_sz = 0;
1038 }
1039 return buf;
1040 }
1041
1042 /**
1043 * link_recv_buf_validate - validate basic format of received message
1044 *
1045 * This routine ensures a TIPC message has an acceptable header, and at least
1046 * as much data as the header indicates it should. The routine also ensures
1047 * that the entire message header is stored in the main fragment of the message
1048 * buffer, to simplify future access to message header fields.
1049 *
1050 * Note: Having extra info present in the message header or data areas is OK.
1051 * TIPC will ignore the excess, under the assumption that it is optional info
1052 * introduced by a later release of the protocol.
1053 */
1054 static int link_recv_buf_validate(struct sk_buff *buf)
1055 {
1056 static u32 min_data_hdr_size[8] = {
1057 SHORT_H_SIZE, MCAST_H_SIZE, NAMED_H_SIZE, BASIC_H_SIZE,
1058 MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE
1059 };
1060
1061 struct tipc_msg *msg;
1062 u32 tipc_hdr[2];
1063 u32 size;
1064 u32 hdr_size;
1065 u32 min_hdr_size;
1066
1067 /* If this packet comes from the defer queue, the skb has already
1068 * been validated
1069 */
1070 if (unlikely(TIPC_SKB_CB(buf)->deferred))
1071 return 1;
1072
1073 if (unlikely(buf->len < MIN_H_SIZE))
1074 return 0;
1075
1076 msg = skb_header_pointer(buf, 0, sizeof(tipc_hdr), tipc_hdr);
1077 if (msg == NULL)
1078 return 0;
1079
1080 if (unlikely(msg_version(msg) != TIPC_VERSION))
1081 return 0;
1082
1083 size = msg_size(msg);
1084 hdr_size = msg_hdr_sz(msg);
1085 min_hdr_size = msg_isdata(msg) ?
1086 min_data_hdr_size[msg_type(msg)] : INT_H_SIZE;
1087
1088 if (unlikely((hdr_size < min_hdr_size) ||
1089 (size < hdr_size) ||
1090 (buf->len < size) ||
1091 (size - hdr_size > TIPC_MAX_USER_MSG_SIZE)))
1092 return 0;
1093
1094 return pskb_may_pull(buf, hdr_size);
1095 }
1096
1097 /**
1098 * tipc_rcv - process TIPC packets/messages arriving from off-node
1099 * @head: pointer to message buffer chain
1100 * @b_ptr: pointer to bearer message arrived on
1101 *
1102 * Invoked with no locks held. Bearer pointer must point to a valid bearer
1103 * structure (i.e. cannot be NULL), but bearer can be inactive.
1104 */
1105 void tipc_rcv(struct sk_buff *head, struct tipc_bearer *b_ptr)
1106 {
1107 while (head) {
1108 struct tipc_node *n_ptr;
1109 struct tipc_link *l_ptr;
1110 struct sk_buff *crs;
1111 struct sk_buff *buf = head;
1112 struct tipc_msg *msg;
1113 u32 seq_no;
1114 u32 ackd;
1115 u32 released = 0;
1116
1117 head = head->next;
1118 buf->next = NULL;
1119
1120 /* Ensure message is well-formed */
1121 if (unlikely(!link_recv_buf_validate(buf)))
1122 goto discard;
1123
1124 /* Ensure message data is a single contiguous unit */
1125 if (unlikely(skb_linearize(buf)))
1126 goto discard;
1127
1128 /* Handle arrival of a non-unicast link message */
1129 msg = buf_msg(buf);
1130
1131 if (unlikely(msg_non_seq(msg))) {
1132 if (msg_user(msg) == LINK_CONFIG)
1133 tipc_disc_rcv(buf, b_ptr);
1134 else
1135 tipc_bclink_rcv(buf);
1136 continue;
1137 }
1138
1139 /* Discard unicast link messages destined for another node */
1140 if (unlikely(!msg_short(msg) &&
1141 (msg_destnode(msg) != tipc_own_addr)))
1142 goto discard;
1143
1144 /* Locate neighboring node that sent message */
1145 n_ptr = tipc_node_find(msg_prevnode(msg));
1146 if (unlikely(!n_ptr))
1147 goto discard;
1148 tipc_node_lock(n_ptr);
1149
1150 /* Locate unicast link endpoint that should handle message */
1151 l_ptr = n_ptr->links[b_ptr->identity];
1152 if (unlikely(!l_ptr))
1153 goto unlock_discard;
1154
1155 /* Verify that communication with node is currently allowed */
1156 if ((n_ptr->action_flags & TIPC_WAIT_PEER_LINKS_DOWN) &&
1157 msg_user(msg) == LINK_PROTOCOL &&
1158 (msg_type(msg) == RESET_MSG ||
1159 msg_type(msg) == ACTIVATE_MSG) &&
1160 !msg_redundant_link(msg))
1161 n_ptr->action_flags &= ~TIPC_WAIT_PEER_LINKS_DOWN;
1162
1163 if (tipc_node_blocked(n_ptr))
1164 goto unlock_discard;
1165
1166 /* Validate message sequence number info */
1167 seq_no = msg_seqno(msg);
1168 ackd = msg_ack(msg);
1169
1170 /* Release acked messages */
1171 if (n_ptr->bclink.recv_permitted)
1172 tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
1173
1174 crs = l_ptr->first_out;
1175 while ((crs != l_ptr->next_out) &&
1176 less_eq(buf_seqno(crs), ackd)) {
1177 struct sk_buff *next = crs->next;
1178 kfree_skb(crs);
1179 crs = next;
1180 released++;
1181 }
1182 if (released) {
1183 l_ptr->first_out = crs;
1184 l_ptr->out_queue_size -= released;
1185 }
1186
1187 /* Try sending any messages link endpoint has pending */
1188 if (unlikely(l_ptr->next_out))
1189 tipc_link_push_queue(l_ptr);
1190
1191 if (released && !skb_queue_empty(&l_ptr->waiting_sks)) {
1192 link_prepare_wakeup(l_ptr);
1193 l_ptr->owner->action_flags |= TIPC_WAKEUP_USERS;
1194 }
1195
1196 /* Process the incoming packet */
1197 if (unlikely(!link_working_working(l_ptr))) {
1198 if (msg_user(msg) == LINK_PROTOCOL) {
1199 tipc_link_proto_rcv(l_ptr, buf);
1200 head = link_insert_deferred_queue(l_ptr, head);
1201 tipc_node_unlock(n_ptr);
1202 continue;
1203 }
1204
1205 /* Traffic message. Conditionally activate link */
1206 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1207
1208 if (link_working_working(l_ptr)) {
1209 /* Re-insert buffer in front of queue */
1210 buf->next = head;
1211 head = buf;
1212 tipc_node_unlock(n_ptr);
1213 continue;
1214 }
1215 goto unlock_discard;
1216 }
1217
1218 /* Link is now in state WORKING_WORKING */
1219 if (unlikely(seq_no != mod(l_ptr->next_in_no))) {
1220 link_handle_out_of_seq_msg(l_ptr, buf);
1221 head = link_insert_deferred_queue(l_ptr, head);
1222 tipc_node_unlock(n_ptr);
1223 continue;
1224 }
1225 l_ptr->next_in_no++;
1226 if (unlikely(l_ptr->oldest_deferred_in))
1227 head = link_insert_deferred_queue(l_ptr, head);
1228
1229 if (unlikely(++l_ptr->unacked_window >= TIPC_MIN_LINK_WIN)) {
1230 l_ptr->stats.sent_acks++;
1231 tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1232 }
1233
1234 if (tipc_link_prepare_input(l_ptr, &buf)) {
1235 tipc_node_unlock(n_ptr);
1236 continue;
1237 }
1238 tipc_node_unlock(n_ptr);
1239 msg = buf_msg(buf);
1240 if (tipc_link_input(l_ptr, buf) != 0)
1241 goto discard;
1242 continue;
1243 unlock_discard:
1244 tipc_node_unlock(n_ptr);
1245 discard:
1246 kfree_skb(buf);
1247 }
1248 }
1249
1250 /**
1251 * tipc_link_prepare_input - process TIPC link messages
1252 *
1253 * returns nonzero if the message was consumed
1254 *
1255 * Node lock must be held
1256 */
1257 static int tipc_link_prepare_input(struct tipc_link *l, struct sk_buff **buf)
1258 {
1259 struct tipc_node *n;
1260 struct tipc_msg *msg;
1261 int res = -EINVAL;
1262
1263 n = l->owner;
1264 msg = buf_msg(*buf);
1265 switch (msg_user(msg)) {
1266 case CHANGEOVER_PROTOCOL:
1267 if (tipc_link_tunnel_rcv(n, buf))
1268 res = 0;
1269 break;
1270 case MSG_FRAGMENTER:
1271 l->stats.recv_fragments++;
1272 if (tipc_buf_append(&l->reasm_buf, buf)) {
1273 l->stats.recv_fragmented++;
1274 res = 0;
1275 } else if (!l->reasm_buf) {
1276 tipc_link_reset(l);
1277 }
1278 break;
1279 case MSG_BUNDLER:
1280 l->stats.recv_bundles++;
1281 l->stats.recv_bundled += msg_msgcnt(msg);
1282 res = 0;
1283 break;
1284 case NAME_DISTRIBUTOR:
1285 n->bclink.recv_permitted = true;
1286 res = 0;
1287 break;
1288 case BCAST_PROTOCOL:
1289 tipc_link_sync_rcv(n, *buf);
1290 break;
1291 default:
1292 res = 0;
1293 }
1294 return res;
1295 }
1296 /**
1297 * tipc_link_input - Deliver message too higher layers
1298 */
1299 static int tipc_link_input(struct tipc_link *l, struct sk_buff *buf)
1300 {
1301 struct tipc_msg *msg = buf_msg(buf);
1302 int res = 0;
1303
1304 switch (msg_user(msg)) {
1305 case TIPC_LOW_IMPORTANCE:
1306 case TIPC_MEDIUM_IMPORTANCE:
1307 case TIPC_HIGH_IMPORTANCE:
1308 case TIPC_CRITICAL_IMPORTANCE:
1309 case CONN_MANAGER:
1310 tipc_sk_rcv(buf);
1311 break;
1312 case NAME_DISTRIBUTOR:
1313 tipc_named_rcv(buf);
1314 break;
1315 case MSG_BUNDLER:
1316 tipc_link_bundle_rcv(buf);
1317 break;
1318 default:
1319 res = -EINVAL;
1320 }
1321 return res;
1322 }
1323
1324 /**
1325 * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
1326 *
1327 * Returns increase in queue length (i.e. 0 or 1)
1328 */
1329 u32 tipc_link_defer_pkt(struct sk_buff **head, struct sk_buff **tail,
1330 struct sk_buff *buf)
1331 {
1332 struct sk_buff *queue_buf;
1333 struct sk_buff **prev;
1334 u32 seq_no = buf_seqno(buf);
1335
1336 buf->next = NULL;
1337
1338 /* Empty queue ? */
1339 if (*head == NULL) {
1340 *head = *tail = buf;
1341 return 1;
1342 }
1343
1344 /* Last ? */
1345 if (less(buf_seqno(*tail), seq_no)) {
1346 (*tail)->next = buf;
1347 *tail = buf;
1348 return 1;
1349 }
1350
1351 /* Locate insertion point in queue, then insert; discard if duplicate */
1352 prev = head;
1353 queue_buf = *head;
1354 for (;;) {
1355 u32 curr_seqno = buf_seqno(queue_buf);
1356
1357 if (seq_no == curr_seqno) {
1358 kfree_skb(buf);
1359 return 0;
1360 }
1361
1362 if (less(seq_no, curr_seqno))
1363 break;
1364
1365 prev = &queue_buf->next;
1366 queue_buf = queue_buf->next;
1367 }
1368
1369 buf->next = queue_buf;
1370 *prev = buf;
1371 return 1;
1372 }
1373
1374 /*
1375 * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
1376 */
1377 static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
1378 struct sk_buff *buf)
1379 {
1380 u32 seq_no = buf_seqno(buf);
1381
1382 if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) {
1383 tipc_link_proto_rcv(l_ptr, buf);
1384 return;
1385 }
1386
1387 /* Record OOS packet arrival (force mismatch on next timeout) */
1388 l_ptr->checkpoint--;
1389
1390 /*
1391 * Discard packet if a duplicate; otherwise add it to deferred queue
1392 * and notify peer of gap as per protocol specification
1393 */
1394 if (less(seq_no, mod(l_ptr->next_in_no))) {
1395 l_ptr->stats.duplicates++;
1396 kfree_skb(buf);
1397 return;
1398 }
1399
1400 if (tipc_link_defer_pkt(&l_ptr->oldest_deferred_in,
1401 &l_ptr->newest_deferred_in, buf)) {
1402 l_ptr->deferred_inqueue_sz++;
1403 l_ptr->stats.deferred_recv++;
1404 TIPC_SKB_CB(buf)->deferred = true;
1405 if ((l_ptr->deferred_inqueue_sz % 16) == 1)
1406 tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1407 } else
1408 l_ptr->stats.duplicates++;
1409 }
1410
1411 /*
1412 * Send protocol message to the other endpoint.
1413 */
1414 void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int probe_msg,
1415 u32 gap, u32 tolerance, u32 priority, u32 ack_mtu)
1416 {
1417 struct sk_buff *buf = NULL;
1418 struct tipc_msg *msg = l_ptr->pmsg;
1419 u32 msg_size = sizeof(l_ptr->proto_msg);
1420 int r_flag;
1421
1422 /* Discard any previous message that was deferred due to congestion */
1423 if (l_ptr->proto_msg_queue) {
1424 kfree_skb(l_ptr->proto_msg_queue);
1425 l_ptr->proto_msg_queue = NULL;
1426 }
1427
1428 /* Don't send protocol message during link changeover */
1429 if (l_ptr->exp_msg_count)
1430 return;
1431
1432 /* Abort non-RESET send if communication with node is prohibited */
1433 if ((tipc_node_blocked(l_ptr->owner)) && (msg_typ != RESET_MSG))
1434 return;
1435
1436 /* Create protocol message with "out-of-sequence" sequence number */
1437 msg_set_type(msg, msg_typ);
1438 msg_set_net_plane(msg, l_ptr->net_plane);
1439 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1440 msg_set_last_bcast(msg, tipc_bclink_get_last_sent());
1441
1442 if (msg_typ == STATE_MSG) {
1443 u32 next_sent = mod(l_ptr->next_out_no);
1444
1445 if (!tipc_link_is_up(l_ptr))
1446 return;
1447 if (l_ptr->next_out)
1448 next_sent = buf_seqno(l_ptr->next_out);
1449 msg_set_next_sent(msg, next_sent);
1450 if (l_ptr->oldest_deferred_in) {
1451 u32 rec = buf_seqno(l_ptr->oldest_deferred_in);
1452 gap = mod(rec - mod(l_ptr->next_in_no));
1453 }
1454 msg_set_seq_gap(msg, gap);
1455 if (gap)
1456 l_ptr->stats.sent_nacks++;
1457 msg_set_link_tolerance(msg, tolerance);
1458 msg_set_linkprio(msg, priority);
1459 msg_set_max_pkt(msg, ack_mtu);
1460 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1461 msg_set_probe(msg, probe_msg != 0);
1462 if (probe_msg) {
1463 u32 mtu = l_ptr->max_pkt;
1464
1465 if ((mtu < l_ptr->max_pkt_target) &&
1466 link_working_working(l_ptr) &&
1467 l_ptr->fsm_msg_cnt) {
1468 msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
1469 if (l_ptr->max_pkt_probes == 10) {
1470 l_ptr->max_pkt_target = (msg_size - 4);
1471 l_ptr->max_pkt_probes = 0;
1472 msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
1473 }
1474 l_ptr->max_pkt_probes++;
1475 }
1476
1477 l_ptr->stats.sent_probes++;
1478 }
1479 l_ptr->stats.sent_states++;
1480 } else { /* RESET_MSG or ACTIVATE_MSG */
1481 msg_set_ack(msg, mod(l_ptr->reset_checkpoint - 1));
1482 msg_set_seq_gap(msg, 0);
1483 msg_set_next_sent(msg, 1);
1484 msg_set_probe(msg, 0);
1485 msg_set_link_tolerance(msg, l_ptr->tolerance);
1486 msg_set_linkprio(msg, l_ptr->priority);
1487 msg_set_max_pkt(msg, l_ptr->max_pkt_target);
1488 }
1489
1490 r_flag = (l_ptr->owner->working_links > tipc_link_is_up(l_ptr));
1491 msg_set_redundant_link(msg, r_flag);
1492 msg_set_linkprio(msg, l_ptr->priority);
1493 msg_set_size(msg, msg_size);
1494
1495 msg_set_seqno(msg, mod(l_ptr->next_out_no + (0xffff/2)));
1496
1497 buf = tipc_buf_acquire(msg_size);
1498 if (!buf)
1499 return;
1500
1501 skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
1502 buf->priority = TC_PRIO_CONTROL;
1503
1504 tipc_bearer_send(l_ptr->bearer_id, buf, &l_ptr->media_addr);
1505 l_ptr->unacked_window = 0;
1506 kfree_skb(buf);
1507 }
1508
1509 /*
1510 * Receive protocol message :
1511 * Note that network plane id propagates through the network, and may
1512 * change at any time. The node with lowest address rules
1513 */
1514 static void tipc_link_proto_rcv(struct tipc_link *l_ptr, struct sk_buff *buf)
1515 {
1516 u32 rec_gap = 0;
1517 u32 max_pkt_info;
1518 u32 max_pkt_ack;
1519 u32 msg_tol;
1520 struct tipc_msg *msg = buf_msg(buf);
1521
1522 /* Discard protocol message during link changeover */
1523 if (l_ptr->exp_msg_count)
1524 goto exit;
1525
1526 if (l_ptr->net_plane != msg_net_plane(msg))
1527 if (tipc_own_addr > msg_prevnode(msg))
1528 l_ptr->net_plane = msg_net_plane(msg);
1529
1530 switch (msg_type(msg)) {
1531
1532 case RESET_MSG:
1533 if (!link_working_unknown(l_ptr) &&
1534 (l_ptr->peer_session != INVALID_SESSION)) {
1535 if (less_eq(msg_session(msg), l_ptr->peer_session))
1536 break; /* duplicate or old reset: ignore */
1537 }
1538
1539 if (!msg_redundant_link(msg) && (link_working_working(l_ptr) ||
1540 link_working_unknown(l_ptr))) {
1541 /*
1542 * peer has lost contact -- don't allow peer's links
1543 * to reactivate before we recognize loss & clean up
1544 */
1545 l_ptr->owner->action_flags |= TIPC_WAIT_OWN_LINKS_DOWN;
1546 }
1547
1548 link_state_event(l_ptr, RESET_MSG);
1549
1550 /* fall thru' */
1551 case ACTIVATE_MSG:
1552 /* Update link settings according other endpoint's values */
1553 strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg));
1554
1555 msg_tol = msg_link_tolerance(msg);
1556 if (msg_tol > l_ptr->tolerance)
1557 link_set_supervision_props(l_ptr, msg_tol);
1558
1559 if (msg_linkprio(msg) > l_ptr->priority)
1560 l_ptr->priority = msg_linkprio(msg);
1561
1562 max_pkt_info = msg_max_pkt(msg);
1563 if (max_pkt_info) {
1564 if (max_pkt_info < l_ptr->max_pkt_target)
1565 l_ptr->max_pkt_target = max_pkt_info;
1566 if (l_ptr->max_pkt > l_ptr->max_pkt_target)
1567 l_ptr->max_pkt = l_ptr->max_pkt_target;
1568 } else {
1569 l_ptr->max_pkt = l_ptr->max_pkt_target;
1570 }
1571
1572 /* Synchronize broadcast link info, if not done previously */
1573 if (!tipc_node_is_up(l_ptr->owner)) {
1574 l_ptr->owner->bclink.last_sent =
1575 l_ptr->owner->bclink.last_in =
1576 msg_last_bcast(msg);
1577 l_ptr->owner->bclink.oos_state = 0;
1578 }
1579
1580 l_ptr->peer_session = msg_session(msg);
1581 l_ptr->peer_bearer_id = msg_bearer_id(msg);
1582
1583 if (msg_type(msg) == ACTIVATE_MSG)
1584 link_state_event(l_ptr, ACTIVATE_MSG);
1585 break;
1586 case STATE_MSG:
1587
1588 msg_tol = msg_link_tolerance(msg);
1589 if (msg_tol)
1590 link_set_supervision_props(l_ptr, msg_tol);
1591
1592 if (msg_linkprio(msg) &&
1593 (msg_linkprio(msg) != l_ptr->priority)) {
1594 pr_warn("%s<%s>, priority change %u->%u\n",
1595 link_rst_msg, l_ptr->name, l_ptr->priority,
1596 msg_linkprio(msg));
1597 l_ptr->priority = msg_linkprio(msg);
1598 tipc_link_reset(l_ptr); /* Enforce change to take effect */
1599 break;
1600 }
1601
1602 /* Record reception; force mismatch at next timeout: */
1603 l_ptr->checkpoint--;
1604
1605 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1606 l_ptr->stats.recv_states++;
1607 if (link_reset_unknown(l_ptr))
1608 break;
1609
1610 if (less_eq(mod(l_ptr->next_in_no), msg_next_sent(msg))) {
1611 rec_gap = mod(msg_next_sent(msg) -
1612 mod(l_ptr->next_in_no));
1613 }
1614
1615 max_pkt_ack = msg_max_pkt(msg);
1616 if (max_pkt_ack > l_ptr->max_pkt) {
1617 l_ptr->max_pkt = max_pkt_ack;
1618 l_ptr->max_pkt_probes = 0;
1619 }
1620
1621 max_pkt_ack = 0;
1622 if (msg_probe(msg)) {
1623 l_ptr->stats.recv_probes++;
1624 if (msg_size(msg) > sizeof(l_ptr->proto_msg))
1625 max_pkt_ack = msg_size(msg);
1626 }
1627
1628 /* Protocol message before retransmits, reduce loss risk */
1629 if (l_ptr->owner->bclink.recv_permitted)
1630 tipc_bclink_update_link_state(l_ptr->owner,
1631 msg_last_bcast(msg));
1632
1633 if (rec_gap || (msg_probe(msg))) {
1634 tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, rec_gap, 0,
1635 0, max_pkt_ack);
1636 }
1637 if (msg_seq_gap(msg)) {
1638 l_ptr->stats.recv_nacks++;
1639 tipc_link_retransmit(l_ptr, l_ptr->first_out,
1640 msg_seq_gap(msg));
1641 }
1642 break;
1643 }
1644 exit:
1645 kfree_skb(buf);
1646 }
1647
1648
1649 /* tipc_link_tunnel_xmit(): Tunnel one packet via a link belonging to
1650 * a different bearer. Owner node is locked.
1651 */
1652 static void tipc_link_tunnel_xmit(struct tipc_link *l_ptr,
1653 struct tipc_msg *tunnel_hdr,
1654 struct tipc_msg *msg,
1655 u32 selector)
1656 {
1657 struct tipc_link *tunnel;
1658 struct sk_buff *buf;
1659 u32 length = msg_size(msg);
1660
1661 tunnel = l_ptr->owner->active_links[selector & 1];
1662 if (!tipc_link_is_up(tunnel)) {
1663 pr_warn("%stunnel link no longer available\n", link_co_err);
1664 return;
1665 }
1666 msg_set_size(tunnel_hdr, length + INT_H_SIZE);
1667 buf = tipc_buf_acquire(length + INT_H_SIZE);
1668 if (!buf) {
1669 pr_warn("%sunable to send tunnel msg\n", link_co_err);
1670 return;
1671 }
1672 skb_copy_to_linear_data(buf, tunnel_hdr, INT_H_SIZE);
1673 skb_copy_to_linear_data_offset(buf, INT_H_SIZE, msg, length);
1674 __tipc_link_xmit(tunnel, buf);
1675 }
1676
1677
1678 /* tipc_link_failover_send_queue(): A link has gone down, but a second
1679 * link is still active. We can do failover. Tunnel the failing link's
1680 * whole send queue via the remaining link. This way, we don't lose
1681 * any packets, and sequence order is preserved for subsequent traffic
1682 * sent over the remaining link. Owner node is locked.
1683 */
1684 void tipc_link_failover_send_queue(struct tipc_link *l_ptr)
1685 {
1686 u32 msgcount = l_ptr->out_queue_size;
1687 struct sk_buff *crs = l_ptr->first_out;
1688 struct tipc_link *tunnel = l_ptr->owner->active_links[0];
1689 struct tipc_msg tunnel_hdr;
1690 int split_bundles;
1691
1692 if (!tunnel)
1693 return;
1694
1695 tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
1696 ORIGINAL_MSG, INT_H_SIZE, l_ptr->addr);
1697 msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
1698 msg_set_msgcnt(&tunnel_hdr, msgcount);
1699
1700 if (!l_ptr->first_out) {
1701 struct sk_buff *buf;
1702
1703 buf = tipc_buf_acquire(INT_H_SIZE);
1704 if (buf) {
1705 skb_copy_to_linear_data(buf, &tunnel_hdr, INT_H_SIZE);
1706 msg_set_size(&tunnel_hdr, INT_H_SIZE);
1707 __tipc_link_xmit(tunnel, buf);
1708 } else {
1709 pr_warn("%sunable to send changeover msg\n",
1710 link_co_err);
1711 }
1712 return;
1713 }
1714
1715 split_bundles = (l_ptr->owner->active_links[0] !=
1716 l_ptr->owner->active_links[1]);
1717
1718 while (crs) {
1719 struct tipc_msg *msg = buf_msg(crs);
1720
1721 if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
1722 struct tipc_msg *m = msg_get_wrapped(msg);
1723 unchar *pos = (unchar *)m;
1724
1725 msgcount = msg_msgcnt(msg);
1726 while (msgcount--) {
1727 msg_set_seqno(m, msg_seqno(msg));
1728 tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, m,
1729 msg_link_selector(m));
1730 pos += align(msg_size(m));
1731 m = (struct tipc_msg *)pos;
1732 }
1733 } else {
1734 tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, msg,
1735 msg_link_selector(msg));
1736 }
1737 crs = crs->next;
1738 }
1739 }
1740
1741 /* tipc_link_dup_queue_xmit(): A second link has become active. Tunnel a
1742 * duplicate of the first link's send queue via the new link. This way, we
1743 * are guaranteed that currently queued packets from a socket are delivered
1744 * before future traffic from the same socket, even if this is using the
1745 * new link. The last arriving copy of each duplicate packet is dropped at
1746 * the receiving end by the regular protocol check, so packet cardinality
1747 * and sequence order is preserved per sender/receiver socket pair.
1748 * Owner node is locked.
1749 */
1750 void tipc_link_dup_queue_xmit(struct tipc_link *l_ptr,
1751 struct tipc_link *tunnel)
1752 {
1753 struct sk_buff *iter;
1754 struct tipc_msg tunnel_hdr;
1755
1756 tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
1757 DUPLICATE_MSG, INT_H_SIZE, l_ptr->addr);
1758 msg_set_msgcnt(&tunnel_hdr, l_ptr->out_queue_size);
1759 msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
1760 iter = l_ptr->first_out;
1761 while (iter) {
1762 struct sk_buff *outbuf;
1763 struct tipc_msg *msg = buf_msg(iter);
1764 u32 length = msg_size(msg);
1765
1766 if (msg_user(msg) == MSG_BUNDLER)
1767 msg_set_type(msg, CLOSED_MSG);
1768 msg_set_ack(msg, mod(l_ptr->next_in_no - 1)); /* Update */
1769 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1770 msg_set_size(&tunnel_hdr, length + INT_H_SIZE);
1771 outbuf = tipc_buf_acquire(length + INT_H_SIZE);
1772 if (outbuf == NULL) {
1773 pr_warn("%sunable to send duplicate msg\n",
1774 link_co_err);
1775 return;
1776 }
1777 skb_copy_to_linear_data(outbuf, &tunnel_hdr, INT_H_SIZE);
1778 skb_copy_to_linear_data_offset(outbuf, INT_H_SIZE, iter->data,
1779 length);
1780 __tipc_link_xmit(tunnel, outbuf);
1781 if (!tipc_link_is_up(l_ptr))
1782 return;
1783 iter = iter->next;
1784 }
1785 }
1786
1787 /**
1788 * buf_extract - extracts embedded TIPC message from another message
1789 * @skb: encapsulating message buffer
1790 * @from_pos: offset to extract from
1791 *
1792 * Returns a new message buffer containing an embedded message. The
1793 * encapsulating message itself is left unchanged.
1794 */
1795 static struct sk_buff *buf_extract(struct sk_buff *skb, u32 from_pos)
1796 {
1797 struct tipc_msg *msg = (struct tipc_msg *)(skb->data + from_pos);
1798 u32 size = msg_size(msg);
1799 struct sk_buff *eb;
1800
1801 eb = tipc_buf_acquire(size);
1802 if (eb)
1803 skb_copy_to_linear_data(eb, msg, size);
1804 return eb;
1805 }
1806
1807
1808
1809 /* tipc_link_dup_rcv(): Receive a tunnelled DUPLICATE_MSG packet.
1810 * Owner node is locked.
1811 */
1812 static void tipc_link_dup_rcv(struct tipc_link *l_ptr,
1813 struct sk_buff *t_buf)
1814 {
1815 struct sk_buff *buf;
1816
1817 if (!tipc_link_is_up(l_ptr))
1818 return;
1819
1820 buf = buf_extract(t_buf, INT_H_SIZE);
1821 if (buf == NULL) {
1822 pr_warn("%sfailed to extract inner dup pkt\n", link_co_err);
1823 return;
1824 }
1825
1826 /* Add buffer to deferred queue, if applicable: */
1827 link_handle_out_of_seq_msg(l_ptr, buf);
1828 }
1829
1830 /* tipc_link_failover_rcv(): Receive a tunnelled ORIGINAL_MSG packet
1831 * Owner node is locked.
1832 */
1833 static struct sk_buff *tipc_link_failover_rcv(struct tipc_link *l_ptr,
1834 struct sk_buff *t_buf)
1835 {
1836 struct tipc_msg *t_msg = buf_msg(t_buf);
1837 struct sk_buff *buf = NULL;
1838 struct tipc_msg *msg;
1839
1840 if (tipc_link_is_up(l_ptr))
1841 tipc_link_reset(l_ptr);
1842
1843 /* First failover packet? */
1844 if (l_ptr->exp_msg_count == START_CHANGEOVER)
1845 l_ptr->exp_msg_count = msg_msgcnt(t_msg);
1846
1847 /* Should there be an inner packet? */
1848 if (l_ptr->exp_msg_count) {
1849 l_ptr->exp_msg_count--;
1850 buf = buf_extract(t_buf, INT_H_SIZE);
1851 if (buf == NULL) {
1852 pr_warn("%sno inner failover pkt\n", link_co_err);
1853 goto exit;
1854 }
1855 msg = buf_msg(buf);
1856
1857 if (less(msg_seqno(msg), l_ptr->reset_checkpoint)) {
1858 kfree_skb(buf);
1859 buf = NULL;
1860 goto exit;
1861 }
1862 if (msg_user(msg) == MSG_FRAGMENTER) {
1863 l_ptr->stats.recv_fragments++;
1864 tipc_buf_append(&l_ptr->reasm_buf, &buf);
1865 }
1866 }
1867 exit:
1868 if ((l_ptr->exp_msg_count == 0) && (l_ptr->flags & LINK_STOPPED)) {
1869 tipc_node_detach_link(l_ptr->owner, l_ptr);
1870 kfree(l_ptr);
1871 }
1872 return buf;
1873 }
1874
1875 /* tipc_link_tunnel_rcv(): Receive a tunnelled packet, sent
1876 * via other link as result of a failover (ORIGINAL_MSG) or
1877 * a new active link (DUPLICATE_MSG). Failover packets are
1878 * returned to the active link for delivery upwards.
1879 * Owner node is locked.
1880 */
1881 static int tipc_link_tunnel_rcv(struct tipc_node *n_ptr,
1882 struct sk_buff **buf)
1883 {
1884 struct sk_buff *t_buf = *buf;
1885 struct tipc_link *l_ptr;
1886 struct tipc_msg *t_msg = buf_msg(t_buf);
1887 u32 bearer_id = msg_bearer_id(t_msg);
1888
1889 *buf = NULL;
1890
1891 if (bearer_id >= MAX_BEARERS)
1892 goto exit;
1893
1894 l_ptr = n_ptr->links[bearer_id];
1895 if (!l_ptr)
1896 goto exit;
1897
1898 if (msg_type(t_msg) == DUPLICATE_MSG)
1899 tipc_link_dup_rcv(l_ptr, t_buf);
1900 else if (msg_type(t_msg) == ORIGINAL_MSG)
1901 *buf = tipc_link_failover_rcv(l_ptr, t_buf);
1902 else
1903 pr_warn("%sunknown tunnel pkt received\n", link_co_err);
1904 exit:
1905 kfree_skb(t_buf);
1906 return *buf != NULL;
1907 }
1908
1909 /*
1910 * Bundler functionality:
1911 */
1912 void tipc_link_bundle_rcv(struct sk_buff *buf)
1913 {
1914 u32 msgcount = msg_msgcnt(buf_msg(buf));
1915 u32 pos = INT_H_SIZE;
1916 struct sk_buff *obuf;
1917 struct tipc_msg *omsg;
1918
1919 while (msgcount--) {
1920 obuf = buf_extract(buf, pos);
1921 if (obuf == NULL) {
1922 pr_warn("Link unable to unbundle message(s)\n");
1923 break;
1924 }
1925 omsg = buf_msg(obuf);
1926 pos += align(msg_size(omsg));
1927 if (msg_isdata(omsg) || (msg_user(omsg) == CONN_MANAGER)) {
1928 tipc_sk_rcv(obuf);
1929 } else if (msg_user(omsg) == NAME_DISTRIBUTOR) {
1930 tipc_named_rcv(obuf);
1931 } else {
1932 pr_warn("Illegal bundled msg: %u\n", msg_user(omsg));
1933 kfree_skb(obuf);
1934 }
1935 }
1936 kfree_skb(buf);
1937 }
1938
1939 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance)
1940 {
1941 if ((tolerance < TIPC_MIN_LINK_TOL) || (tolerance > TIPC_MAX_LINK_TOL))
1942 return;
1943
1944 l_ptr->tolerance = tolerance;
1945 l_ptr->continuity_interval =
1946 ((tolerance / 4) > 500) ? 500 : tolerance / 4;
1947 l_ptr->abort_limit = tolerance / (l_ptr->continuity_interval / 4);
1948 }
1949
1950 void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window)
1951 {
1952 /* Data messages from this node, inclusive FIRST_FRAGM */
1953 l_ptr->queue_limit[TIPC_LOW_IMPORTANCE] = window;
1954 l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE] = (window / 3) * 4;
1955 l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE] = (window / 3) * 5;
1956 l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE] = (window / 3) * 6;
1957 /* Transiting data messages,inclusive FIRST_FRAGM */
1958 l_ptr->queue_limit[TIPC_LOW_IMPORTANCE + 4] = 300;
1959 l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE + 4] = 600;
1960 l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE + 4] = 900;
1961 l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE + 4] = 1200;
1962 l_ptr->queue_limit[CONN_MANAGER] = 1200;
1963 l_ptr->queue_limit[CHANGEOVER_PROTOCOL] = 2500;
1964 l_ptr->queue_limit[NAME_DISTRIBUTOR] = 3000;
1965 /* FRAGMENT and LAST_FRAGMENT packets */
1966 l_ptr->queue_limit[MSG_FRAGMENTER] = 4000;
1967 }
1968
1969 /* tipc_link_find_owner - locate owner node of link by link's name
1970 * @name: pointer to link name string
1971 * @bearer_id: pointer to index in 'node->links' array where the link was found.
1972 *
1973 * Returns pointer to node owning the link, or 0 if no matching link is found.
1974 */
1975 static struct tipc_node *tipc_link_find_owner(const char *link_name,
1976 unsigned int *bearer_id)
1977 {
1978 struct tipc_link *l_ptr;
1979 struct tipc_node *n_ptr;
1980 struct tipc_node *found_node = 0;
1981 int i;
1982
1983 *bearer_id = 0;
1984 rcu_read_lock();
1985 list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
1986 tipc_node_lock(n_ptr);
1987 for (i = 0; i < MAX_BEARERS; i++) {
1988 l_ptr = n_ptr->links[i];
1989 if (l_ptr && !strcmp(l_ptr->name, link_name)) {
1990 *bearer_id = i;
1991 found_node = n_ptr;
1992 break;
1993 }
1994 }
1995 tipc_node_unlock(n_ptr);
1996 if (found_node)
1997 break;
1998 }
1999 rcu_read_unlock();
2000
2001 return found_node;
2002 }
2003
2004 /**
2005 * link_value_is_valid -- validate proposed link tolerance/priority/window
2006 *
2007 * @cmd: value type (TIPC_CMD_SET_LINK_*)
2008 * @new_value: the new value
2009 *
2010 * Returns 1 if value is within range, 0 if not.
2011 */
2012 static int link_value_is_valid(u16 cmd, u32 new_value)
2013 {
2014 switch (cmd) {
2015 case TIPC_CMD_SET_LINK_TOL:
2016 return (new_value >= TIPC_MIN_LINK_TOL) &&
2017 (new_value <= TIPC_MAX_LINK_TOL);
2018 case TIPC_CMD_SET_LINK_PRI:
2019 return (new_value <= TIPC_MAX_LINK_PRI);
2020 case TIPC_CMD_SET_LINK_WINDOW:
2021 return (new_value >= TIPC_MIN_LINK_WIN) &&
2022 (new_value <= TIPC_MAX_LINK_WIN);
2023 }
2024 return 0;
2025 }
2026
2027 /**
2028 * link_cmd_set_value - change priority/tolerance/window for link/bearer/media
2029 * @name: ptr to link, bearer, or media name
2030 * @new_value: new value of link, bearer, or media setting
2031 * @cmd: which link, bearer, or media attribute to set (TIPC_CMD_SET_LINK_*)
2032 *
2033 * Caller must hold RTNL lock to ensure link/bearer/media is not deleted.
2034 *
2035 * Returns 0 if value updated and negative value on error.
2036 */
2037 static int link_cmd_set_value(const char *name, u32 new_value, u16 cmd)
2038 {
2039 struct tipc_node *node;
2040 struct tipc_link *l_ptr;
2041 struct tipc_bearer *b_ptr;
2042 struct tipc_media *m_ptr;
2043 int bearer_id;
2044 int res = 0;
2045
2046 node = tipc_link_find_owner(name, &bearer_id);
2047 if (node) {
2048 tipc_node_lock(node);
2049 l_ptr = node->links[bearer_id];
2050
2051 if (l_ptr) {
2052 switch (cmd) {
2053 case TIPC_CMD_SET_LINK_TOL:
2054 link_set_supervision_props(l_ptr, new_value);
2055 tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0,
2056 new_value, 0, 0);
2057 break;
2058 case TIPC_CMD_SET_LINK_PRI:
2059 l_ptr->priority = new_value;
2060 tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0,
2061 0, new_value, 0);
2062 break;
2063 case TIPC_CMD_SET_LINK_WINDOW:
2064 tipc_link_set_queue_limits(l_ptr, new_value);
2065 break;
2066 default:
2067 res = -EINVAL;
2068 break;
2069 }
2070 }
2071 tipc_node_unlock(node);
2072 return res;
2073 }
2074
2075 b_ptr = tipc_bearer_find(name);
2076 if (b_ptr) {
2077 switch (cmd) {
2078 case TIPC_CMD_SET_LINK_TOL:
2079 b_ptr->tolerance = new_value;
2080 break;
2081 case TIPC_CMD_SET_LINK_PRI:
2082 b_ptr->priority = new_value;
2083 break;
2084 case TIPC_CMD_SET_LINK_WINDOW:
2085 b_ptr->window = new_value;
2086 break;
2087 default:
2088 res = -EINVAL;
2089 break;
2090 }
2091 return res;
2092 }
2093
2094 m_ptr = tipc_media_find(name);
2095 if (!m_ptr)
2096 return -ENODEV;
2097 switch (cmd) {
2098 case TIPC_CMD_SET_LINK_TOL:
2099 m_ptr->tolerance = new_value;
2100 break;
2101 case TIPC_CMD_SET_LINK_PRI:
2102 m_ptr->priority = new_value;
2103 break;
2104 case TIPC_CMD_SET_LINK_WINDOW:
2105 m_ptr->window = new_value;
2106 break;
2107 default:
2108 res = -EINVAL;
2109 break;
2110 }
2111 return res;
2112 }
2113
2114 struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space,
2115 u16 cmd)
2116 {
2117 struct tipc_link_config *args;
2118 u32 new_value;
2119 int res;
2120
2121 if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_CONFIG))
2122 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2123
2124 args = (struct tipc_link_config *)TLV_DATA(req_tlv_area);
2125 new_value = ntohl(args->value);
2126
2127 if (!link_value_is_valid(cmd, new_value))
2128 return tipc_cfg_reply_error_string(
2129 "cannot change, value invalid");
2130
2131 if (!strcmp(args->name, tipc_bclink_name)) {
2132 if ((cmd == TIPC_CMD_SET_LINK_WINDOW) &&
2133 (tipc_bclink_set_queue_limits(new_value) == 0))
2134 return tipc_cfg_reply_none();
2135 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
2136 " (cannot change setting on broadcast link)");
2137 }
2138
2139 res = link_cmd_set_value(args->name, new_value, cmd);
2140 if (res)
2141 return tipc_cfg_reply_error_string("cannot change link setting");
2142
2143 return tipc_cfg_reply_none();
2144 }
2145
2146 /**
2147 * link_reset_statistics - reset link statistics
2148 * @l_ptr: pointer to link
2149 */
2150 static void link_reset_statistics(struct tipc_link *l_ptr)
2151 {
2152 memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
2153 l_ptr->stats.sent_info = l_ptr->next_out_no;
2154 l_ptr->stats.recv_info = l_ptr->next_in_no;
2155 }
2156
2157 struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space)
2158 {
2159 char *link_name;
2160 struct tipc_link *l_ptr;
2161 struct tipc_node *node;
2162 unsigned int bearer_id;
2163
2164 if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
2165 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2166
2167 link_name = (char *)TLV_DATA(req_tlv_area);
2168 if (!strcmp(link_name, tipc_bclink_name)) {
2169 if (tipc_bclink_reset_stats())
2170 return tipc_cfg_reply_error_string("link not found");
2171 return tipc_cfg_reply_none();
2172 }
2173 node = tipc_link_find_owner(link_name, &bearer_id);
2174 if (!node)
2175 return tipc_cfg_reply_error_string("link not found");
2176
2177 tipc_node_lock(node);
2178 l_ptr = node->links[bearer_id];
2179 if (!l_ptr) {
2180 tipc_node_unlock(node);
2181 return tipc_cfg_reply_error_string("link not found");
2182 }
2183 link_reset_statistics(l_ptr);
2184 tipc_node_unlock(node);
2185 return tipc_cfg_reply_none();
2186 }
2187
2188 /**
2189 * percent - convert count to a percentage of total (rounding up or down)
2190 */
2191 static u32 percent(u32 count, u32 total)
2192 {
2193 return (count * 100 + (total / 2)) / total;
2194 }
2195
2196 /**
2197 * tipc_link_stats - print link statistics
2198 * @name: link name
2199 * @buf: print buffer area
2200 * @buf_size: size of print buffer area
2201 *
2202 * Returns length of print buffer data string (or 0 if error)
2203 */
2204 static int tipc_link_stats(const char *name, char *buf, const u32 buf_size)
2205 {
2206 struct tipc_link *l;
2207 struct tipc_stats *s;
2208 struct tipc_node *node;
2209 char *status;
2210 u32 profile_total = 0;
2211 unsigned int bearer_id;
2212 int ret;
2213
2214 if (!strcmp(name, tipc_bclink_name))
2215 return tipc_bclink_stats(buf, buf_size);
2216
2217 node = tipc_link_find_owner(name, &bearer_id);
2218 if (!node)
2219 return 0;
2220
2221 tipc_node_lock(node);
2222
2223 l = node->links[bearer_id];
2224 if (!l) {
2225 tipc_node_unlock(node);
2226 return 0;
2227 }
2228
2229 s = &l->stats;
2230
2231 if (tipc_link_is_active(l))
2232 status = "ACTIVE";
2233 else if (tipc_link_is_up(l))
2234 status = "STANDBY";
2235 else
2236 status = "DEFUNCT";
2237
2238 ret = tipc_snprintf(buf, buf_size, "Link <%s>\n"
2239 " %s MTU:%u Priority:%u Tolerance:%u ms"
2240 " Window:%u packets\n",
2241 l->name, status, l->max_pkt, l->priority,
2242 l->tolerance, l->queue_limit[0]);
2243
2244 ret += tipc_snprintf(buf + ret, buf_size - ret,
2245 " RX packets:%u fragments:%u/%u bundles:%u/%u\n",
2246 l->next_in_no - s->recv_info, s->recv_fragments,
2247 s->recv_fragmented, s->recv_bundles,
2248 s->recv_bundled);
2249
2250 ret += tipc_snprintf(buf + ret, buf_size - ret,
2251 " TX packets:%u fragments:%u/%u bundles:%u/%u\n",
2252 l->next_out_no - s->sent_info, s->sent_fragments,
2253 s->sent_fragmented, s->sent_bundles,
2254 s->sent_bundled);
2255
2256 profile_total = s->msg_length_counts;
2257 if (!profile_total)
2258 profile_total = 1;
2259
2260 ret += tipc_snprintf(buf + ret, buf_size - ret,
2261 " TX profile sample:%u packets average:%u octets\n"
2262 " 0-64:%u%% -256:%u%% -1024:%u%% -4096:%u%% "
2263 "-16384:%u%% -32768:%u%% -66000:%u%%\n",
2264 s->msg_length_counts,
2265 s->msg_lengths_total / profile_total,
2266 percent(s->msg_length_profile[0], profile_total),
2267 percent(s->msg_length_profile[1], profile_total),
2268 percent(s->msg_length_profile[2], profile_total),
2269 percent(s->msg_length_profile[3], profile_total),
2270 percent(s->msg_length_profile[4], profile_total),
2271 percent(s->msg_length_profile[5], profile_total),
2272 percent(s->msg_length_profile[6], profile_total));
2273
2274 ret += tipc_snprintf(buf + ret, buf_size - ret,
2275 " RX states:%u probes:%u naks:%u defs:%u"
2276 " dups:%u\n", s->recv_states, s->recv_probes,
2277 s->recv_nacks, s->deferred_recv, s->duplicates);
2278
2279 ret += tipc_snprintf(buf + ret, buf_size - ret,
2280 " TX states:%u probes:%u naks:%u acks:%u"
2281 " dups:%u\n", s->sent_states, s->sent_probes,
2282 s->sent_nacks, s->sent_acks, s->retransmitted);
2283
2284 ret += tipc_snprintf(buf + ret, buf_size - ret,
2285 " Congestion link:%u Send queue"
2286 " max:%u avg:%u\n", s->link_congs,
2287 s->max_queue_sz, s->queue_sz_counts ?
2288 (s->accu_queue_sz / s->queue_sz_counts) : 0);
2289
2290 tipc_node_unlock(node);
2291 return ret;
2292 }
2293
2294 struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space)
2295 {
2296 struct sk_buff *buf;
2297 struct tlv_desc *rep_tlv;
2298 int str_len;
2299 int pb_len;
2300 char *pb;
2301
2302 if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
2303 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2304
2305 buf = tipc_cfg_reply_alloc(TLV_SPACE(ULTRA_STRING_MAX_LEN));
2306 if (!buf)
2307 return NULL;
2308
2309 rep_tlv = (struct tlv_desc *)buf->data;
2310 pb = TLV_DATA(rep_tlv);
2311 pb_len = ULTRA_STRING_MAX_LEN;
2312 str_len = tipc_link_stats((char *)TLV_DATA(req_tlv_area),
2313 pb, pb_len);
2314 if (!str_len) {
2315 kfree_skb(buf);
2316 return tipc_cfg_reply_error_string("link not found");
2317 }
2318 str_len += 1; /* for "\0" */
2319 skb_put(buf, TLV_SPACE(str_len));
2320 TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
2321
2322 return buf;
2323 }
2324
2325 /**
2326 * tipc_link_get_max_pkt - get maximum packet size to use when sending to destination
2327 * @dest: network address of destination node
2328 * @selector: used to select from set of active links
2329 *
2330 * If no active link can be found, uses default maximum packet size.
2331 */
2332 u32 tipc_link_get_max_pkt(u32 dest, u32 selector)
2333 {
2334 struct tipc_node *n_ptr;
2335 struct tipc_link *l_ptr;
2336 u32 res = MAX_PKT_DEFAULT;
2337
2338 if (dest == tipc_own_addr)
2339 return MAX_MSG_SIZE;
2340
2341 n_ptr = tipc_node_find(dest);
2342 if (n_ptr) {
2343 tipc_node_lock(n_ptr);
2344 l_ptr = n_ptr->active_links[selector & 1];
2345 if (l_ptr)
2346 res = l_ptr->max_pkt;
2347 tipc_node_unlock(n_ptr);
2348 }
2349 return res;
2350 }
2351
2352 static void link_print(struct tipc_link *l_ptr, const char *str)
2353 {
2354 struct tipc_bearer *b_ptr;
2355
2356 rcu_read_lock();
2357 b_ptr = rcu_dereference_rtnl(bearer_list[l_ptr->bearer_id]);
2358 if (b_ptr)
2359 pr_info("%s Link %x<%s>:", str, l_ptr->addr, b_ptr->name);
2360 rcu_read_unlock();
2361
2362 if (link_working_unknown(l_ptr))
2363 pr_cont(":WU\n");
2364 else if (link_reset_reset(l_ptr))
2365 pr_cont(":RR\n");
2366 else if (link_reset_unknown(l_ptr))
2367 pr_cont(":RU\n");
2368 else if (link_working_working(l_ptr))
2369 pr_cont(":WW\n");
2370 else
2371 pr_cont("\n");
2372 }
Linux kernel - Deliverables
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