?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
ARM: orion5x: clean-up mach/io.h
[linux-2.6/libata-dev.git] / net / tipc / link.c
blobac1832a66f8af9a415144408b63ecf6bdfe01b73
1 /*
2 * net/tipc/link.c: TIPC link code
3 *
4 * Copyright (c) 1996-2007, Ericsson AB
5 * Copyright (c) 2004-2007, 2010-2011, 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
45 /*
46 * Out-of-range value for link session numbers
47 */
48
49 #define INVALID_SESSION 0x10000
50
51 /*
52 * Link state events:
53 */
54
55 #define STARTING_EVT 856384768 /* link processing trigger */
56 #define TRAFFIC_MSG_EVT 560815u /* rx'd ??? */
57 #define TIMEOUT_EVT 560817u /* link timer expired */
58
59 /*
60 * The following two 'message types' is really just implementation
61 * data conveniently stored in the message header.
62 * They must not be considered part of the protocol
63 */
64 #define OPEN_MSG 0
65 #define CLOSED_MSG 1
66
67 /*
68 * State value stored in 'exp_msg_count'
69 */
70
71 #define START_CHANGEOVER 100000u
72
73 /**
74 * struct tipc_link_name - deconstructed link name
75 * @addr_local: network address of node at this end
76 * @if_local: name of interface at this end
77 * @addr_peer: network address of node at far end
78 * @if_peer: name of interface at far end
79 */
80
81 struct tipc_link_name {
82 u32 addr_local;
83 char if_local[TIPC_MAX_IF_NAME];
84 u32 addr_peer;
85 char if_peer[TIPC_MAX_IF_NAME];
86 };
87
88 static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
89 struct sk_buff *buf);
90 static void link_recv_proto_msg(struct tipc_link *l_ptr, struct sk_buff *buf);
91 static int link_recv_changeover_msg(struct tipc_link **l_ptr,
92 struct sk_buff **buf);
93 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance);
94 static int link_send_sections_long(struct tipc_port *sender,
95 struct iovec const *msg_sect,
96 u32 num_sect, unsigned int total_len,
97 u32 destnode);
98 static void link_check_defragm_bufs(struct tipc_link *l_ptr);
99 static void link_state_event(struct tipc_link *l_ptr, u32 event);
100 static void link_reset_statistics(struct tipc_link *l_ptr);
101 static void link_print(struct tipc_link *l_ptr, const char *str);
102 static void link_start(struct tipc_link *l_ptr);
103 static int link_send_long_buf(struct tipc_link *l_ptr, struct sk_buff *buf);
104
105 /*
106 * Simple link routines
107 */
108
109 static unsigned int align(unsigned int i)
110 {
111 return (i + 3) & ~3u;
112 }
113
114 static void link_init_max_pkt(struct tipc_link *l_ptr)
115 {
116 u32 max_pkt;
117
118 max_pkt = (l_ptr->b_ptr->mtu & ~3);
119 if (max_pkt > MAX_MSG_SIZE)
120 max_pkt = MAX_MSG_SIZE;
121
122 l_ptr->max_pkt_target = max_pkt;
123 if (l_ptr->max_pkt_target < MAX_PKT_DEFAULT)
124 l_ptr->max_pkt = l_ptr->max_pkt_target;
125 else
126 l_ptr->max_pkt = MAX_PKT_DEFAULT;
127
128 l_ptr->max_pkt_probes = 0;
129 }
130
131 static u32 link_next_sent(struct tipc_link *l_ptr)
132 {
133 if (l_ptr->next_out)
134 return buf_seqno(l_ptr->next_out);
135 return mod(l_ptr->next_out_no);
136 }
137
138 static u32 link_last_sent(struct tipc_link *l_ptr)
139 {
140 return mod(link_next_sent(l_ptr) - 1);
141 }
142
143 /*
144 * Simple non-static link routines (i.e. referenced outside this file)
145 */
146
147 int tipc_link_is_up(struct tipc_link *l_ptr)
148 {
149 if (!l_ptr)
150 return 0;
151 return link_working_working(l_ptr) || link_working_unknown(l_ptr);
152 }
153
154 int tipc_link_is_active(struct tipc_link *l_ptr)
155 {
156 return (l_ptr->owner->active_links[0] == l_ptr) ||
157 (l_ptr->owner->active_links[1] == l_ptr);
158 }
159
160 /**
161 * link_name_validate - validate & (optionally) deconstruct tipc_link name
162 * @name - ptr to link name string
163 * @name_parts - ptr to area for link name components (or NULL if not needed)
164 *
165 * Returns 1 if link name is valid, otherwise 0.
166 */
167
168 static int link_name_validate(const char *name,
169 struct tipc_link_name *name_parts)
170 {
171 char name_copy[TIPC_MAX_LINK_NAME];
172 char *addr_local;
173 char *if_local;
174 char *addr_peer;
175 char *if_peer;
176 char dummy;
177 u32 z_local, c_local, n_local;
178 u32 z_peer, c_peer, n_peer;
179 u32 if_local_len;
180 u32 if_peer_len;
181
182 /* copy link name & ensure length is OK */
183
184 name_copy[TIPC_MAX_LINK_NAME - 1] = 0;
185 /* need above in case non-Posix strncpy() doesn't pad with nulls */
186 strncpy(name_copy, name, TIPC_MAX_LINK_NAME);
187 if (name_copy[TIPC_MAX_LINK_NAME - 1] != 0)
188 return 0;
189
190 /* ensure all component parts of link name are present */
191
192 addr_local = name_copy;
193 if_local = strchr(addr_local, ':');
194 if (if_local == NULL)
195 return 0;
196 *(if_local++) = 0;
197 addr_peer = strchr(if_local, '-');
198 if (addr_peer == NULL)
199 return 0;
200 *(addr_peer++) = 0;
201 if_local_len = addr_peer - if_local;
202 if_peer = strchr(addr_peer, ':');
203 if (if_peer == NULL)
204 return 0;
205 *(if_peer++) = 0;
206 if_peer_len = strlen(if_peer) + 1;
207
208 /* validate component parts of link name */
209
210 if ((sscanf(addr_local, "%u.%u.%u%c",
211 &z_local, &c_local, &n_local, &dummy) != 3) ||
212 (sscanf(addr_peer, "%u.%u.%u%c",
213 &z_peer, &c_peer, &n_peer, &dummy) != 3) ||
214 (z_local > 255) || (c_local > 4095) || (n_local > 4095) ||
215 (z_peer > 255) || (c_peer > 4095) || (n_peer > 4095) ||
216 (if_local_len <= 1) || (if_local_len > TIPC_MAX_IF_NAME) ||
217 (if_peer_len <= 1) || (if_peer_len > TIPC_MAX_IF_NAME) ||
218 (strspn(if_local, tipc_alphabet) != (if_local_len - 1)) ||
219 (strspn(if_peer, tipc_alphabet) != (if_peer_len - 1)))
220 return 0;
221
222 /* return link name components, if necessary */
223
224 if (name_parts) {
225 name_parts->addr_local = tipc_addr(z_local, c_local, n_local);
226 strcpy(name_parts->if_local, if_local);
227 name_parts->addr_peer = tipc_addr(z_peer, c_peer, n_peer);
228 strcpy(name_parts->if_peer, if_peer);
229 }
230 return 1;
231 }
232
233 /**
234 * link_timeout - handle expiration of link timer
235 * @l_ptr: pointer to link
236 *
237 * This routine must not grab "tipc_net_lock" to avoid a potential deadlock conflict
238 * with tipc_link_delete(). (There is no risk that the node will be deleted by
239 * another thread because tipc_link_delete() always cancels the link timer before
240 * tipc_node_delete() is called.)
241 */
242
243 static void link_timeout(struct tipc_link *l_ptr)
244 {
245 tipc_node_lock(l_ptr->owner);
246
247 /* update counters used in statistical profiling of send traffic */
248
249 l_ptr->stats.accu_queue_sz += l_ptr->out_queue_size;
250 l_ptr->stats.queue_sz_counts++;
251
252 if (l_ptr->first_out) {
253 struct tipc_msg *msg = buf_msg(l_ptr->first_out);
254 u32 length = msg_size(msg);
255
256 if ((msg_user(msg) == MSG_FRAGMENTER) &&
257 (msg_type(msg) == FIRST_FRAGMENT)) {
258 length = msg_size(msg_get_wrapped(msg));
259 }
260 if (length) {
261 l_ptr->stats.msg_lengths_total += length;
262 l_ptr->stats.msg_length_counts++;
263 if (length <= 64)
264 l_ptr->stats.msg_length_profile[0]++;
265 else if (length <= 256)
266 l_ptr->stats.msg_length_profile[1]++;
267 else if (length <= 1024)
268 l_ptr->stats.msg_length_profile[2]++;
269 else if (length <= 4096)
270 l_ptr->stats.msg_length_profile[3]++;
271 else if (length <= 16384)
272 l_ptr->stats.msg_length_profile[4]++;
273 else if (length <= 32768)
274 l_ptr->stats.msg_length_profile[5]++;
275 else
276 l_ptr->stats.msg_length_profile[6]++;
277 }
278 }
279
280 /* do all other link processing performed on a periodic basis */
281
282 link_check_defragm_bufs(l_ptr);
283
284 link_state_event(l_ptr, TIMEOUT_EVT);
285
286 if (l_ptr->next_out)
287 tipc_link_push_queue(l_ptr);
288
289 tipc_node_unlock(l_ptr->owner);
290 }
291
292 static void link_set_timer(struct tipc_link *l_ptr, u32 time)
293 {
294 k_start_timer(&l_ptr->timer, time);
295 }
296
297 /**
298 * tipc_link_create - create a new link
299 * @n_ptr: pointer to associated node
300 * @b_ptr: pointer to associated bearer
301 * @media_addr: media address to use when sending messages over link
302 *
303 * Returns pointer to link.
304 */
305
306 struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
307 struct tipc_bearer *b_ptr,
308 const struct tipc_media_addr *media_addr)
309 {
310 struct tipc_link *l_ptr;
311 struct tipc_msg *msg;
312 char *if_name;
313 char addr_string[16];
314 u32 peer = n_ptr->addr;
315
316 if (n_ptr->link_cnt >= 2) {
317 tipc_addr_string_fill(addr_string, n_ptr->addr);
318 err("Attempt to establish third link to %s\n", addr_string);
319 return NULL;
320 }
321
322 if (n_ptr->links[b_ptr->identity]) {
323 tipc_addr_string_fill(addr_string, n_ptr->addr);
324 err("Attempt to establish second link on <%s> to %s\n",
325 b_ptr->name, addr_string);
326 return NULL;
327 }
328
329 l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
330 if (!l_ptr) {
331 warn("Link creation failed, no memory\n");
332 return NULL;
333 }
334
335 l_ptr->addr = peer;
336 if_name = strchr(b_ptr->name, ':') + 1;
337 sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
338 tipc_zone(tipc_own_addr), tipc_cluster(tipc_own_addr),
339 tipc_node(tipc_own_addr),
340 if_name,
341 tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
342 /* note: peer i/f name is updated by reset/activate message */
343 memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
344 l_ptr->owner = n_ptr;
345 l_ptr->checkpoint = 1;
346 l_ptr->peer_session = INVALID_SESSION;
347 l_ptr->b_ptr = b_ptr;
348 link_set_supervision_props(l_ptr, b_ptr->tolerance);
349 l_ptr->state = RESET_UNKNOWN;
350
351 l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
352 msg = l_ptr->pmsg;
353 tipc_msg_init(msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, l_ptr->addr);
354 msg_set_size(msg, sizeof(l_ptr->proto_msg));
355 msg_set_session(msg, (tipc_random & 0xffff));
356 msg_set_bearer_id(msg, b_ptr->identity);
357 strcpy((char *)msg_data(msg), if_name);
358
359 l_ptr->priority = b_ptr->priority;
360 tipc_link_set_queue_limits(l_ptr, b_ptr->window);
361
362 link_init_max_pkt(l_ptr);
363
364 l_ptr->next_out_no = 1;
365 INIT_LIST_HEAD(&l_ptr->waiting_ports);
366
367 link_reset_statistics(l_ptr);
368
369 tipc_node_attach_link(n_ptr, l_ptr);
370
371 k_init_timer(&l_ptr->timer, (Handler)link_timeout, (unsigned long)l_ptr);
372 list_add_tail(&l_ptr->link_list, &b_ptr->links);
373 tipc_k_signal((Handler)link_start, (unsigned long)l_ptr);
374
375 return l_ptr;
376 }
377
378 /**
379 * tipc_link_delete - delete a link
380 * @l_ptr: pointer to link
381 *
382 * Note: 'tipc_net_lock' is write_locked, bearer is locked.
383 * This routine must not grab the node lock until after link timer cancellation
384 * to avoid a potential deadlock situation.
385 */
386
387 void tipc_link_delete(struct tipc_link *l_ptr)
388 {
389 if (!l_ptr) {
390 err("Attempt to delete non-existent link\n");
391 return;
392 }
393
394 k_cancel_timer(&l_ptr->timer);
395
396 tipc_node_lock(l_ptr->owner);
397 tipc_link_reset(l_ptr);
398 tipc_node_detach_link(l_ptr->owner, l_ptr);
399 tipc_link_stop(l_ptr);
400 list_del_init(&l_ptr->link_list);
401 tipc_node_unlock(l_ptr->owner);
402 k_term_timer(&l_ptr->timer);
403 kfree(l_ptr);
404 }
405
406 static void link_start(struct tipc_link *l_ptr)
407 {
408 tipc_node_lock(l_ptr->owner);
409 link_state_event(l_ptr, STARTING_EVT);
410 tipc_node_unlock(l_ptr->owner);
411 }
412
413 /**
414 * link_schedule_port - schedule port for deferred sending
415 * @l_ptr: pointer to link
416 * @origport: reference to sending port
417 * @sz: amount of data to be sent
418 *
419 * Schedules port for renewed sending of messages after link congestion
420 * has abated.
421 */
422
423 static int link_schedule_port(struct tipc_link *l_ptr, u32 origport, u32 sz)
424 {
425 struct tipc_port *p_ptr;
426
427 spin_lock_bh(&tipc_port_list_lock);
428 p_ptr = tipc_port_lock(origport);
429 if (p_ptr) {
430 if (!p_ptr->wakeup)
431 goto exit;
432 if (!list_empty(&p_ptr->wait_list))
433 goto exit;
434 p_ptr->congested = 1;
435 p_ptr->waiting_pkts = 1 + ((sz - 1) / l_ptr->max_pkt);
436 list_add_tail(&p_ptr->wait_list, &l_ptr->waiting_ports);
437 l_ptr->stats.link_congs++;
438 exit:
439 tipc_port_unlock(p_ptr);
440 }
441 spin_unlock_bh(&tipc_port_list_lock);
442 return -ELINKCONG;
443 }
444
445 void tipc_link_wakeup_ports(struct tipc_link *l_ptr, int all)
446 {
447 struct tipc_port *p_ptr;
448 struct tipc_port *temp_p_ptr;
449 int win = l_ptr->queue_limit[0] - l_ptr->out_queue_size;
450
451 if (all)
452 win = 100000;
453 if (win <= 0)
454 return;
455 if (!spin_trylock_bh(&tipc_port_list_lock))
456 return;
457 if (link_congested(l_ptr))
458 goto exit;
459 list_for_each_entry_safe(p_ptr, temp_p_ptr, &l_ptr->waiting_ports,
460 wait_list) {
461 if (win <= 0)
462 break;
463 list_del_init(&p_ptr->wait_list);
464 spin_lock_bh(p_ptr->lock);
465 p_ptr->congested = 0;
466 p_ptr->wakeup(p_ptr);
467 win -= p_ptr->waiting_pkts;
468 spin_unlock_bh(p_ptr->lock);
469 }
470
471 exit:
472 spin_unlock_bh(&tipc_port_list_lock);
473 }
474
475 /**
476 * link_release_outqueue - purge link's outbound message queue
477 * @l_ptr: pointer to link
478 */
479
480 static void link_release_outqueue(struct tipc_link *l_ptr)
481 {
482 struct sk_buff *buf = l_ptr->first_out;
483 struct sk_buff *next;
484
485 while (buf) {
486 next = buf->next;
487 buf_discard(buf);
488 buf = next;
489 }
490 l_ptr->first_out = NULL;
491 l_ptr->out_queue_size = 0;
492 }
493
494 /**
495 * tipc_link_reset_fragments - purge link's inbound message fragments queue
496 * @l_ptr: pointer to link
497 */
498
499 void tipc_link_reset_fragments(struct tipc_link *l_ptr)
500 {
501 struct sk_buff *buf = l_ptr->defragm_buf;
502 struct sk_buff *next;
503
504 while (buf) {
505 next = buf->next;
506 buf_discard(buf);
507 buf = next;
508 }
509 l_ptr->defragm_buf = NULL;
510 }
511
512 /**
513 * tipc_link_stop - purge all inbound and outbound messages associated with link
514 * @l_ptr: pointer to link
515 */
516
517 void tipc_link_stop(struct tipc_link *l_ptr)
518 {
519 struct sk_buff *buf;
520 struct sk_buff *next;
521
522 buf = l_ptr->oldest_deferred_in;
523 while (buf) {
524 next = buf->next;
525 buf_discard(buf);
526 buf = next;
527 }
528
529 buf = l_ptr->first_out;
530 while (buf) {
531 next = buf->next;
532 buf_discard(buf);
533 buf = next;
534 }
535
536 tipc_link_reset_fragments(l_ptr);
537
538 buf_discard(l_ptr->proto_msg_queue);
539 l_ptr->proto_msg_queue = NULL;
540 }
541
542 void tipc_link_reset(struct tipc_link *l_ptr)
543 {
544 struct sk_buff *buf;
545 u32 prev_state = l_ptr->state;
546 u32 checkpoint = l_ptr->next_in_no;
547 int was_active_link = tipc_link_is_active(l_ptr);
548
549 msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
550
551 /* Link is down, accept any session */
552 l_ptr->peer_session = INVALID_SESSION;
553
554 /* Prepare for max packet size negotiation */
555 link_init_max_pkt(l_ptr);
556
557 l_ptr->state = RESET_UNKNOWN;
558
559 if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
560 return;
561
562 tipc_node_link_down(l_ptr->owner, l_ptr);
563 tipc_bearer_remove_dest(l_ptr->b_ptr, l_ptr->addr);
564
565 if (was_active_link && tipc_node_active_links(l_ptr->owner) &&
566 l_ptr->owner->permit_changeover) {
567 l_ptr->reset_checkpoint = checkpoint;
568 l_ptr->exp_msg_count = START_CHANGEOVER;
569 }
570
571 /* Clean up all queues: */
572
573 link_release_outqueue(l_ptr);
574 buf_discard(l_ptr->proto_msg_queue);
575 l_ptr->proto_msg_queue = NULL;
576 buf = l_ptr->oldest_deferred_in;
577 while (buf) {
578 struct sk_buff *next = buf->next;
579 buf_discard(buf);
580 buf = next;
581 }
582 if (!list_empty(&l_ptr->waiting_ports))
583 tipc_link_wakeup_ports(l_ptr, 1);
584
585 l_ptr->retransm_queue_head = 0;
586 l_ptr->retransm_queue_size = 0;
587 l_ptr->last_out = NULL;
588 l_ptr->first_out = NULL;
589 l_ptr->next_out = NULL;
590 l_ptr->unacked_window = 0;
591 l_ptr->checkpoint = 1;
592 l_ptr->next_out_no = 1;
593 l_ptr->deferred_inqueue_sz = 0;
594 l_ptr->oldest_deferred_in = NULL;
595 l_ptr->newest_deferred_in = NULL;
596 l_ptr->fsm_msg_cnt = 0;
597 l_ptr->stale_count = 0;
598 link_reset_statistics(l_ptr);
599 }
600
601
602 static void link_activate(struct tipc_link *l_ptr)
603 {
604 l_ptr->next_in_no = l_ptr->stats.recv_info = 1;
605 tipc_node_link_up(l_ptr->owner, l_ptr);
606 tipc_bearer_add_dest(l_ptr->b_ptr, l_ptr->addr);
607 }
608
609 /**
610 * link_state_event - link finite state machine
611 * @l_ptr: pointer to link
612 * @event: state machine event to process
613 */
614
615 static void link_state_event(struct tipc_link *l_ptr, unsigned event)
616 {
617 struct tipc_link *other;
618 u32 cont_intv = l_ptr->continuity_interval;
619
620 if (!l_ptr->started && (event != STARTING_EVT))
621 return; /* Not yet. */
622
623 if (link_blocked(l_ptr)) {
624 if (event == TIMEOUT_EVT)
625 link_set_timer(l_ptr, cont_intv);
626 return; /* Changeover going on */
627 }
628
629 switch (l_ptr->state) {
630 case WORKING_WORKING:
631 switch (event) {
632 case TRAFFIC_MSG_EVT:
633 case ACTIVATE_MSG:
634 break;
635 case TIMEOUT_EVT:
636 if (l_ptr->next_in_no != l_ptr->checkpoint) {
637 l_ptr->checkpoint = l_ptr->next_in_no;
638 if (tipc_bclink_acks_missing(l_ptr->owner)) {
639 tipc_link_send_proto_msg(l_ptr, STATE_MSG,
640 0, 0, 0, 0, 0);
641 l_ptr->fsm_msg_cnt++;
642 } else if (l_ptr->max_pkt < l_ptr->max_pkt_target) {
643 tipc_link_send_proto_msg(l_ptr, STATE_MSG,
644 1, 0, 0, 0, 0);
645 l_ptr->fsm_msg_cnt++;
646 }
647 link_set_timer(l_ptr, cont_intv);
648 break;
649 }
650 l_ptr->state = WORKING_UNKNOWN;
651 l_ptr->fsm_msg_cnt = 0;
652 tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
653 l_ptr->fsm_msg_cnt++;
654 link_set_timer(l_ptr, cont_intv / 4);
655 break;
656 case RESET_MSG:
657 info("Resetting link <%s>, requested by peer\n",
658 l_ptr->name);
659 tipc_link_reset(l_ptr);
660 l_ptr->state = RESET_RESET;
661 l_ptr->fsm_msg_cnt = 0;
662 tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
663 l_ptr->fsm_msg_cnt++;
664 link_set_timer(l_ptr, cont_intv);
665 break;
666 default:
667 err("Unknown link event %u in WW state\n", event);
668 }
669 break;
670 case WORKING_UNKNOWN:
671 switch (event) {
672 case TRAFFIC_MSG_EVT:
673 case ACTIVATE_MSG:
674 l_ptr->state = WORKING_WORKING;
675 l_ptr->fsm_msg_cnt = 0;
676 link_set_timer(l_ptr, cont_intv);
677 break;
678 case RESET_MSG:
679 info("Resetting link <%s>, requested by peer "
680 "while probing\n", l_ptr->name);
681 tipc_link_reset(l_ptr);
682 l_ptr->state = RESET_RESET;
683 l_ptr->fsm_msg_cnt = 0;
684 tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
685 l_ptr->fsm_msg_cnt++;
686 link_set_timer(l_ptr, cont_intv);
687 break;
688 case TIMEOUT_EVT:
689 if (l_ptr->next_in_no != l_ptr->checkpoint) {
690 l_ptr->state = WORKING_WORKING;
691 l_ptr->fsm_msg_cnt = 0;
692 l_ptr->checkpoint = l_ptr->next_in_no;
693 if (tipc_bclink_acks_missing(l_ptr->owner)) {
694 tipc_link_send_proto_msg(l_ptr, STATE_MSG,
695 0, 0, 0, 0, 0);
696 l_ptr->fsm_msg_cnt++;
697 }
698 link_set_timer(l_ptr, cont_intv);
699 } else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) {
700 tipc_link_send_proto_msg(l_ptr, STATE_MSG,
701 1, 0, 0, 0, 0);
702 l_ptr->fsm_msg_cnt++;
703 link_set_timer(l_ptr, cont_intv / 4);
704 } else { /* Link has failed */
705 warn("Resetting link <%s>, peer not responding\n",
706 l_ptr->name);
707 tipc_link_reset(l_ptr);
708 l_ptr->state = RESET_UNKNOWN;
709 l_ptr->fsm_msg_cnt = 0;
710 tipc_link_send_proto_msg(l_ptr, RESET_MSG,
711 0, 0, 0, 0, 0);
712 l_ptr->fsm_msg_cnt++;
713 link_set_timer(l_ptr, cont_intv);
714 }
715 break;
716 default:
717 err("Unknown link event %u in WU state\n", event);
718 }
719 break;
720 case RESET_UNKNOWN:
721 switch (event) {
722 case TRAFFIC_MSG_EVT:
723 break;
724 case ACTIVATE_MSG:
725 other = l_ptr->owner->active_links[0];
726 if (other && link_working_unknown(other))
727 break;
728 l_ptr->state = WORKING_WORKING;
729 l_ptr->fsm_msg_cnt = 0;
730 link_activate(l_ptr);
731 tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
732 l_ptr->fsm_msg_cnt++;
733 link_set_timer(l_ptr, cont_intv);
734 break;
735 case RESET_MSG:
736 l_ptr->state = RESET_RESET;
737 l_ptr->fsm_msg_cnt = 0;
738 tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 1, 0, 0, 0, 0);
739 l_ptr->fsm_msg_cnt++;
740 link_set_timer(l_ptr, cont_intv);
741 break;
742 case STARTING_EVT:
743 l_ptr->started = 1;
744 /* fall through */
745 case TIMEOUT_EVT:
746 tipc_link_send_proto_msg(l_ptr, RESET_MSG, 0, 0, 0, 0, 0);
747 l_ptr->fsm_msg_cnt++;
748 link_set_timer(l_ptr, cont_intv);
749 break;
750 default:
751 err("Unknown link event %u in RU state\n", event);
752 }
753 break;
754 case RESET_RESET:
755 switch (event) {
756 case TRAFFIC_MSG_EVT:
757 case ACTIVATE_MSG:
758 other = l_ptr->owner->active_links[0];
759 if (other && link_working_unknown(other))
760 break;
761 l_ptr->state = WORKING_WORKING;
762 l_ptr->fsm_msg_cnt = 0;
763 link_activate(l_ptr);
764 tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
765 l_ptr->fsm_msg_cnt++;
766 link_set_timer(l_ptr, cont_intv);
767 break;
768 case RESET_MSG:
769 break;
770 case TIMEOUT_EVT:
771 tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
772 l_ptr->fsm_msg_cnt++;
773 link_set_timer(l_ptr, cont_intv);
774 break;
775 default:
776 err("Unknown link event %u in RR state\n", event);
777 }
778 break;
779 default:
780 err("Unknown link state %u/%u\n", l_ptr->state, event);
781 }
782 }
783
784 /*
785 * link_bundle_buf(): Append contents of a buffer to
786 * the tail of an existing one.
787 */
788
789 static int link_bundle_buf(struct tipc_link *l_ptr,
790 struct sk_buff *bundler,
791 struct sk_buff *buf)
792 {
793 struct tipc_msg *bundler_msg = buf_msg(bundler);
794 struct tipc_msg *msg = buf_msg(buf);
795 u32 size = msg_size(msg);
796 u32 bundle_size = msg_size(bundler_msg);
797 u32 to_pos = align(bundle_size);
798 u32 pad = to_pos - bundle_size;
799
800 if (msg_user(bundler_msg) != MSG_BUNDLER)
801 return 0;
802 if (msg_type(bundler_msg) != OPEN_MSG)
803 return 0;
804 if (skb_tailroom(bundler) < (pad + size))
805 return 0;
806 if (l_ptr->max_pkt < (to_pos + size))
807 return 0;
808
809 skb_put(bundler, pad + size);
810 skb_copy_to_linear_data_offset(bundler, to_pos, buf->data, size);
811 msg_set_size(bundler_msg, to_pos + size);
812 msg_set_msgcnt(bundler_msg, msg_msgcnt(bundler_msg) + 1);
813 buf_discard(buf);
814 l_ptr->stats.sent_bundled++;
815 return 1;
816 }
817
818 static void link_add_to_outqueue(struct tipc_link *l_ptr,
819 struct sk_buff *buf,
820 struct tipc_msg *msg)
821 {
822 u32 ack = mod(l_ptr->next_in_no - 1);
823 u32 seqno = mod(l_ptr->next_out_no++);
824
825 msg_set_word(msg, 2, ((ack << 16) | seqno));
826 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
827 buf->next = NULL;
828 if (l_ptr->first_out) {
829 l_ptr->last_out->next = buf;
830 l_ptr->last_out = buf;
831 } else
832 l_ptr->first_out = l_ptr->last_out = buf;
833
834 l_ptr->out_queue_size++;
835 if (l_ptr->out_queue_size > l_ptr->stats.max_queue_sz)
836 l_ptr->stats.max_queue_sz = l_ptr->out_queue_size;
837 }
838
839 static void link_add_chain_to_outqueue(struct tipc_link *l_ptr,
840 struct sk_buff *buf_chain,
841 u32 long_msgno)
842 {
843 struct sk_buff *buf;
844 struct tipc_msg *msg;
845
846 if (!l_ptr->next_out)
847 l_ptr->next_out = buf_chain;
848 while (buf_chain) {
849 buf = buf_chain;
850 buf_chain = buf_chain->next;
851
852 msg = buf_msg(buf);
853 msg_set_long_msgno(msg, long_msgno);
854 link_add_to_outqueue(l_ptr, buf, msg);
855 }
856 }
857
858 /*
859 * tipc_link_send_buf() is the 'full path' for messages, called from
860 * inside TIPC when the 'fast path' in tipc_send_buf
861 * has failed, and from link_send()
862 */
863
864 int tipc_link_send_buf(struct tipc_link *l_ptr, struct sk_buff *buf)
865 {
866 struct tipc_msg *msg = buf_msg(buf);
867 u32 size = msg_size(msg);
868 u32 dsz = msg_data_sz(msg);
869 u32 queue_size = l_ptr->out_queue_size;
870 u32 imp = tipc_msg_tot_importance(msg);
871 u32 queue_limit = l_ptr->queue_limit[imp];
872 u32 max_packet = l_ptr->max_pkt;
873
874 msg_set_prevnode(msg, tipc_own_addr); /* If routed message */
875
876 /* Match msg importance against queue limits: */
877
878 if (unlikely(queue_size >= queue_limit)) {
879 if (imp <= TIPC_CRITICAL_IMPORTANCE) {
880 link_schedule_port(l_ptr, msg_origport(msg), size);
881 buf_discard(buf);
882 return -ELINKCONG;
883 }
884 buf_discard(buf);
885 if (imp > CONN_MANAGER) {
886 warn("Resetting link <%s>, send queue full", l_ptr->name);
887 tipc_link_reset(l_ptr);
888 }
889 return dsz;
890 }
891
892 /* Fragmentation needed ? */
893
894 if (size > max_packet)
895 return link_send_long_buf(l_ptr, buf);
896
897 /* Packet can be queued or sent: */
898
899 if (likely(!tipc_bearer_congested(l_ptr->b_ptr, l_ptr) &&
900 !link_congested(l_ptr))) {
901 link_add_to_outqueue(l_ptr, buf, msg);
902
903 if (likely(tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr))) {
904 l_ptr->unacked_window = 0;
905 } else {
906 tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
907 l_ptr->stats.bearer_congs++;
908 l_ptr->next_out = buf;
909 }
910 return dsz;
911 }
912 /* Congestion: can message be bundled ?: */
913
914 if ((msg_user(msg) != CHANGEOVER_PROTOCOL) &&
915 (msg_user(msg) != MSG_FRAGMENTER)) {
916
917 /* Try adding message to an existing bundle */
918
919 if (l_ptr->next_out &&
920 link_bundle_buf(l_ptr, l_ptr->last_out, buf)) {
921 tipc_bearer_resolve_congestion(l_ptr->b_ptr, l_ptr);
922 return dsz;
923 }
924
925 /* Try creating a new bundle */
926
927 if (size <= max_packet * 2 / 3) {
928 struct sk_buff *bundler = tipc_buf_acquire(max_packet);
929 struct tipc_msg bundler_hdr;
930
931 if (bundler) {
932 tipc_msg_init(&bundler_hdr, MSG_BUNDLER, OPEN_MSG,
933 INT_H_SIZE, l_ptr->addr);
934 skb_copy_to_linear_data(bundler, &bundler_hdr,
935 INT_H_SIZE);
936 skb_trim(bundler, INT_H_SIZE);
937 link_bundle_buf(l_ptr, bundler, buf);
938 buf = bundler;
939 msg = buf_msg(buf);
940 l_ptr->stats.sent_bundles++;
941 }
942 }
943 }
944 if (!l_ptr->next_out)
945 l_ptr->next_out = buf;
946 link_add_to_outqueue(l_ptr, buf, msg);
947 tipc_bearer_resolve_congestion(l_ptr->b_ptr, l_ptr);
948 return dsz;
949 }
950
951 /*
952 * tipc_link_send(): same as tipc_link_send_buf(), but the link to use has
953 * not been selected yet, and the the owner node is not locked
954 * Called by TIPC internal users, e.g. the name distributor
955 */
956
957 int tipc_link_send(struct sk_buff *buf, u32 dest, u32 selector)
958 {
959 struct tipc_link *l_ptr;
960 struct tipc_node *n_ptr;
961 int res = -ELINKCONG;
962
963 read_lock_bh(&tipc_net_lock);
964 n_ptr = tipc_node_find(dest);
965 if (n_ptr) {
966 tipc_node_lock(n_ptr);
967 l_ptr = n_ptr->active_links[selector & 1];
968 if (l_ptr)
969 res = tipc_link_send_buf(l_ptr, buf);
970 else
971 buf_discard(buf);
972 tipc_node_unlock(n_ptr);
973 } else {
974 buf_discard(buf);
975 }
976 read_unlock_bh(&tipc_net_lock);
977 return res;
978 }
979
980 /*
981 * tipc_link_send_names - send name table entries to new neighbor
982 *
983 * Send routine for bulk delivery of name table messages when contact
984 * with a new neighbor occurs. No link congestion checking is performed
985 * because name table messages *must* be delivered. The messages must be
986 * small enough not to require fragmentation.
987 * Called without any locks held.
988 */
989
990 void tipc_link_send_names(struct list_head *message_list, u32 dest)
991 {
992 struct tipc_node *n_ptr;
993 struct tipc_link *l_ptr;
994 struct sk_buff *buf;
995 struct sk_buff *temp_buf;
996
997 if (list_empty(message_list))
998 return;
999
1000 read_lock_bh(&tipc_net_lock);
1001 n_ptr = tipc_node_find(dest);
1002 if (n_ptr) {
1003 tipc_node_lock(n_ptr);
1004 l_ptr = n_ptr->active_links[0];
1005 if (l_ptr) {
1006 /* convert circular list to linear list */
1007 ((struct sk_buff *)message_list->prev)->next = NULL;
1008 link_add_chain_to_outqueue(l_ptr,
1009 (struct sk_buff *)message_list->next, 0);
1010 tipc_link_push_queue(l_ptr);
1011 INIT_LIST_HEAD(message_list);
1012 }
1013 tipc_node_unlock(n_ptr);
1014 }
1015 read_unlock_bh(&tipc_net_lock);
1016
1017 /* discard the messages if they couldn't be sent */
1018
1019 list_for_each_safe(buf, temp_buf, ((struct sk_buff *)message_list)) {
1020 list_del((struct list_head *)buf);
1021 buf_discard(buf);
1022 }
1023 }
1024
1025 /*
1026 * link_send_buf_fast: Entry for data messages where the
1027 * destination link is known and the header is complete,
1028 * inclusive total message length. Very time critical.
1029 * Link is locked. Returns user data length.
1030 */
1031
1032 static int link_send_buf_fast(struct tipc_link *l_ptr, struct sk_buff *buf,
1033 u32 *used_max_pkt)
1034 {
1035 struct tipc_msg *msg = buf_msg(buf);
1036 int res = msg_data_sz(msg);
1037
1038 if (likely(!link_congested(l_ptr))) {
1039 if (likely(msg_size(msg) <= l_ptr->max_pkt)) {
1040 if (likely(list_empty(&l_ptr->b_ptr->cong_links))) {
1041 link_add_to_outqueue(l_ptr, buf, msg);
1042 if (likely(tipc_bearer_send(l_ptr->b_ptr, buf,
1043 &l_ptr->media_addr))) {
1044 l_ptr->unacked_window = 0;
1045 return res;
1046 }
1047 tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
1048 l_ptr->stats.bearer_congs++;
1049 l_ptr->next_out = buf;
1050 return res;
1051 }
1052 } else
1053 *used_max_pkt = l_ptr->max_pkt;
1054 }
1055 return tipc_link_send_buf(l_ptr, buf); /* All other cases */
1056 }
1057
1058 /*
1059 * tipc_send_buf_fast: Entry for data messages where the
1060 * destination node is known and the header is complete,
1061 * inclusive total message length.
1062 * Returns user data length.
1063 */
1064 int tipc_send_buf_fast(struct sk_buff *buf, u32 destnode)
1065 {
1066 struct tipc_link *l_ptr;
1067 struct tipc_node *n_ptr;
1068 int res;
1069 u32 selector = msg_origport(buf_msg(buf)) & 1;
1070 u32 dummy;
1071
1072 read_lock_bh(&tipc_net_lock);
1073 n_ptr = tipc_node_find(destnode);
1074 if (likely(n_ptr)) {
1075 tipc_node_lock(n_ptr);
1076 l_ptr = n_ptr->active_links[selector];
1077 if (likely(l_ptr)) {
1078 res = link_send_buf_fast(l_ptr, buf, &dummy);
1079 tipc_node_unlock(n_ptr);
1080 read_unlock_bh(&tipc_net_lock);
1081 return res;
1082 }
1083 tipc_node_unlock(n_ptr);
1084 }
1085 read_unlock_bh(&tipc_net_lock);
1086 res = msg_data_sz(buf_msg(buf));
1087 tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
1088 return res;
1089 }
1090
1091
1092 /*
1093 * tipc_link_send_sections_fast: Entry for messages where the
1094 * destination processor is known and the header is complete,
1095 * except for total message length.
1096 * Returns user data length or errno.
1097 */
1098 int tipc_link_send_sections_fast(struct tipc_port *sender,
1099 struct iovec const *msg_sect,
1100 const u32 num_sect,
1101 unsigned int total_len,
1102 u32 destaddr)
1103 {
1104 struct tipc_msg *hdr = &sender->phdr;
1105 struct tipc_link *l_ptr;
1106 struct sk_buff *buf;
1107 struct tipc_node *node;
1108 int res;
1109 u32 selector = msg_origport(hdr) & 1;
1110
1111 again:
1112 /*
1113 * Try building message using port's max_pkt hint.
1114 * (Must not hold any locks while building message.)
1115 */
1116
1117 res = tipc_msg_build(hdr, msg_sect, num_sect, total_len,
1118 sender->max_pkt, !sender->user_port, &buf);
1119
1120 read_lock_bh(&tipc_net_lock);
1121 node = tipc_node_find(destaddr);
1122 if (likely(node)) {
1123 tipc_node_lock(node);
1124 l_ptr = node->active_links[selector];
1125 if (likely(l_ptr)) {
1126 if (likely(buf)) {
1127 res = link_send_buf_fast(l_ptr, buf,
1128 &sender->max_pkt);
1129 exit:
1130 tipc_node_unlock(node);
1131 read_unlock_bh(&tipc_net_lock);
1132 return res;
1133 }
1134
1135 /* Exit if build request was invalid */
1136
1137 if (unlikely(res < 0))
1138 goto exit;
1139
1140 /* Exit if link (or bearer) is congested */
1141
1142 if (link_congested(l_ptr) ||
1143 !list_empty(&l_ptr->b_ptr->cong_links)) {
1144 res = link_schedule_port(l_ptr,
1145 sender->ref, res);
1146 goto exit;
1147 }
1148
1149 /*
1150 * Message size exceeds max_pkt hint; update hint,
1151 * then re-try fast path or fragment the message
1152 */
1153
1154 sender->max_pkt = l_ptr->max_pkt;
1155 tipc_node_unlock(node);
1156 read_unlock_bh(&tipc_net_lock);
1157
1158
1159 if ((msg_hdr_sz(hdr) + res) <= sender->max_pkt)
1160 goto again;
1161
1162 return link_send_sections_long(sender, msg_sect,
1163 num_sect, total_len,
1164 destaddr);
1165 }
1166 tipc_node_unlock(node);
1167 }
1168 read_unlock_bh(&tipc_net_lock);
1169
1170 /* Couldn't find a link to the destination node */
1171
1172 if (buf)
1173 return tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
1174 if (res >= 0)
1175 return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
1176 total_len, TIPC_ERR_NO_NODE);
1177 return res;
1178 }
1179
1180 /*
1181 * link_send_sections_long(): Entry for long messages where the
1182 * destination node is known and the header is complete,
1183 * inclusive total message length.
1184 * Link and bearer congestion status have been checked to be ok,
1185 * and are ignored if they change.
1186 *
1187 * Note that fragments do not use the full link MTU so that they won't have
1188 * to undergo refragmentation if link changeover causes them to be sent
1189 * over another link with an additional tunnel header added as prefix.
1190 * (Refragmentation will still occur if the other link has a smaller MTU.)
1191 *
1192 * Returns user data length or errno.
1193 */
1194 static int link_send_sections_long(struct tipc_port *sender,
1195 struct iovec const *msg_sect,
1196 u32 num_sect,
1197 unsigned int total_len,
1198 u32 destaddr)
1199 {
1200 struct tipc_link *l_ptr;
1201 struct tipc_node *node;
1202 struct tipc_msg *hdr = &sender->phdr;
1203 u32 dsz = total_len;
1204 u32 max_pkt, fragm_sz, rest;
1205 struct tipc_msg fragm_hdr;
1206 struct sk_buff *buf, *buf_chain, *prev;
1207 u32 fragm_crs, fragm_rest, hsz, sect_rest;
1208 const unchar *sect_crs;
1209 int curr_sect;
1210 u32 fragm_no;
1211
1212 again:
1213 fragm_no = 1;
1214 max_pkt = sender->max_pkt - INT_H_SIZE;
1215 /* leave room for tunnel header in case of link changeover */
1216 fragm_sz = max_pkt - INT_H_SIZE;
1217 /* leave room for fragmentation header in each fragment */
1218 rest = dsz;
1219 fragm_crs = 0;
1220 fragm_rest = 0;
1221 sect_rest = 0;
1222 sect_crs = NULL;
1223 curr_sect = -1;
1224
1225 /* Prepare reusable fragment header: */
1226
1227 tipc_msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
1228 INT_H_SIZE, msg_destnode(hdr));
1229 msg_set_size(&fragm_hdr, max_pkt);
1230 msg_set_fragm_no(&fragm_hdr, 1);
1231
1232 /* Prepare header of first fragment: */
1233
1234 buf_chain = buf = tipc_buf_acquire(max_pkt);
1235 if (!buf)
1236 return -ENOMEM;
1237 buf->next = NULL;
1238 skb_copy_to_linear_data(buf, &fragm_hdr, INT_H_SIZE);
1239 hsz = msg_hdr_sz(hdr);
1240 skb_copy_to_linear_data_offset(buf, INT_H_SIZE, hdr, hsz);
1241
1242 /* Chop up message: */
1243
1244 fragm_crs = INT_H_SIZE + hsz;
1245 fragm_rest = fragm_sz - hsz;
1246
1247 do { /* For all sections */
1248 u32 sz;
1249
1250 if (!sect_rest) {
1251 sect_rest = msg_sect[++curr_sect].iov_len;
1252 sect_crs = (const unchar *)msg_sect[curr_sect].iov_base;
1253 }
1254
1255 if (sect_rest < fragm_rest)
1256 sz = sect_rest;
1257 else
1258 sz = fragm_rest;
1259
1260 if (likely(!sender->user_port)) {
1261 if (copy_from_user(buf->data + fragm_crs, sect_crs, sz)) {
1262 error:
1263 for (; buf_chain; buf_chain = buf) {
1264 buf = buf_chain->next;
1265 buf_discard(buf_chain);
1266 }
1267 return -EFAULT;
1268 }
1269 } else
1270 skb_copy_to_linear_data_offset(buf, fragm_crs,
1271 sect_crs, sz);
1272 sect_crs += sz;
1273 sect_rest -= sz;
1274 fragm_crs += sz;
1275 fragm_rest -= sz;
1276 rest -= sz;
1277
1278 if (!fragm_rest && rest) {
1279
1280 /* Initiate new fragment: */
1281 if (rest <= fragm_sz) {
1282 fragm_sz = rest;
1283 msg_set_type(&fragm_hdr, LAST_FRAGMENT);
1284 } else {
1285 msg_set_type(&fragm_hdr, FRAGMENT);
1286 }
1287 msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
1288 msg_set_fragm_no(&fragm_hdr, ++fragm_no);
1289 prev = buf;
1290 buf = tipc_buf_acquire(fragm_sz + INT_H_SIZE);
1291 if (!buf)
1292 goto error;
1293
1294 buf->next = NULL;
1295 prev->next = buf;
1296 skb_copy_to_linear_data(buf, &fragm_hdr, INT_H_SIZE);
1297 fragm_crs = INT_H_SIZE;
1298 fragm_rest = fragm_sz;
1299 }
1300 } while (rest > 0);
1301
1302 /*
1303 * Now we have a buffer chain. Select a link and check
1304 * that packet size is still OK
1305 */
1306 node = tipc_node_find(destaddr);
1307 if (likely(node)) {
1308 tipc_node_lock(node);
1309 l_ptr = node->active_links[sender->ref & 1];
1310 if (!l_ptr) {
1311 tipc_node_unlock(node);
1312 goto reject;
1313 }
1314 if (l_ptr->max_pkt < max_pkt) {
1315 sender->max_pkt = l_ptr->max_pkt;
1316 tipc_node_unlock(node);
1317 for (; buf_chain; buf_chain = buf) {
1318 buf = buf_chain->next;
1319 buf_discard(buf_chain);
1320 }
1321 goto again;
1322 }
1323 } else {
1324 reject:
1325 for (; buf_chain; buf_chain = buf) {
1326 buf = buf_chain->next;
1327 buf_discard(buf_chain);
1328 }
1329 return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
1330 total_len, TIPC_ERR_NO_NODE);
1331 }
1332
1333 /* Append chain of fragments to send queue & send them */
1334
1335 l_ptr->long_msg_seq_no++;
1336 link_add_chain_to_outqueue(l_ptr, buf_chain, l_ptr->long_msg_seq_no);
1337 l_ptr->stats.sent_fragments += fragm_no;
1338 l_ptr->stats.sent_fragmented++;
1339 tipc_link_push_queue(l_ptr);
1340 tipc_node_unlock(node);
1341 return dsz;
1342 }
1343
1344 /*
1345 * tipc_link_push_packet: Push one unsent packet to the media
1346 */
1347 u32 tipc_link_push_packet(struct tipc_link *l_ptr)
1348 {
1349 struct sk_buff *buf = l_ptr->first_out;
1350 u32 r_q_size = l_ptr->retransm_queue_size;
1351 u32 r_q_head = l_ptr->retransm_queue_head;
1352
1353 /* Step to position where retransmission failed, if any, */
1354 /* consider that buffers may have been released in meantime */
1355
1356 if (r_q_size && buf) {
1357 u32 last = lesser(mod(r_q_head + r_q_size),
1358 link_last_sent(l_ptr));
1359 u32 first = buf_seqno(buf);
1360
1361 while (buf && less(first, r_q_head)) {
1362 first = mod(first + 1);
1363 buf = buf->next;
1364 }
1365 l_ptr->retransm_queue_head = r_q_head = first;
1366 l_ptr->retransm_queue_size = r_q_size = mod(last - first);
1367 }
1368
1369 /* Continue retransmission now, if there is anything: */
1370
1371 if (r_q_size && buf) {
1372 msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
1373 msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
1374 if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1375 l_ptr->retransm_queue_head = mod(++r_q_head);
1376 l_ptr->retransm_queue_size = --r_q_size;
1377 l_ptr->stats.retransmitted++;
1378 return 0;
1379 } else {
1380 l_ptr->stats.bearer_congs++;
1381 return PUSH_FAILED;
1382 }
1383 }
1384
1385 /* Send deferred protocol message, if any: */
1386
1387 buf = l_ptr->proto_msg_queue;
1388 if (buf) {
1389 msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
1390 msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
1391 if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1392 l_ptr->unacked_window = 0;
1393 buf_discard(buf);
1394 l_ptr->proto_msg_queue = NULL;
1395 return 0;
1396 } else {
1397 l_ptr->stats.bearer_congs++;
1398 return PUSH_FAILED;
1399 }
1400 }
1401
1402 /* Send one deferred data message, if send window not full: */
1403
1404 buf = l_ptr->next_out;
1405 if (buf) {
1406 struct tipc_msg *msg = buf_msg(buf);
1407 u32 next = msg_seqno(msg);
1408 u32 first = buf_seqno(l_ptr->first_out);
1409
1410 if (mod(next - first) < l_ptr->queue_limit[0]) {
1411 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1412 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1413 if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1414 if (msg_user(msg) == MSG_BUNDLER)
1415 msg_set_type(msg, CLOSED_MSG);
1416 l_ptr->next_out = buf->next;
1417 return 0;
1418 } else {
1419 l_ptr->stats.bearer_congs++;
1420 return PUSH_FAILED;
1421 }
1422 }
1423 }
1424 return PUSH_FINISHED;
1425 }
1426
1427 /*
1428 * push_queue(): push out the unsent messages of a link where
1429 * congestion has abated. Node is locked
1430 */
1431 void tipc_link_push_queue(struct tipc_link *l_ptr)
1432 {
1433 u32 res;
1434
1435 if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr))
1436 return;
1437
1438 do {
1439 res = tipc_link_push_packet(l_ptr);
1440 } while (!res);
1441
1442 if (res == PUSH_FAILED)
1443 tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
1444 }
1445
1446 static void link_reset_all(unsigned long addr)
1447 {
1448 struct tipc_node *n_ptr;
1449 char addr_string[16];
1450 u32 i;
1451
1452 read_lock_bh(&tipc_net_lock);
1453 n_ptr = tipc_node_find((u32)addr);
1454 if (!n_ptr) {
1455 read_unlock_bh(&tipc_net_lock);
1456 return; /* node no longer exists */
1457 }
1458
1459 tipc_node_lock(n_ptr);
1460
1461 warn("Resetting all links to %s\n",
1462 tipc_addr_string_fill(addr_string, n_ptr->addr));
1463
1464 for (i = 0; i < MAX_BEARERS; i++) {
1465 if (n_ptr->links[i]) {
1466 link_print(n_ptr->links[i], "Resetting link\n");
1467 tipc_link_reset(n_ptr->links[i]);
1468 }
1469 }
1470
1471 tipc_node_unlock(n_ptr);
1472 read_unlock_bh(&tipc_net_lock);
1473 }
1474
1475 static void link_retransmit_failure(struct tipc_link *l_ptr,
1476 struct sk_buff *buf)
1477 {
1478 struct tipc_msg *msg = buf_msg(buf);
1479
1480 warn("Retransmission failure on link <%s>\n", l_ptr->name);
1481
1482 if (l_ptr->addr) {
1483
1484 /* Handle failure on standard link */
1485
1486 link_print(l_ptr, "Resetting link\n");
1487 tipc_link_reset(l_ptr);
1488
1489 } else {
1490
1491 /* Handle failure on broadcast link */
1492
1493 struct tipc_node *n_ptr;
1494 char addr_string[16];
1495
1496 info("Msg seq number: %u, ", msg_seqno(msg));
1497 info("Outstanding acks: %lu\n",
1498 (unsigned long) TIPC_SKB_CB(buf)->handle);
1499
1500 n_ptr = tipc_bclink_retransmit_to();
1501 tipc_node_lock(n_ptr);
1502
1503 tipc_addr_string_fill(addr_string, n_ptr->addr);
1504 info("Multicast link info for %s\n", addr_string);
1505 info("Supported: %d, ", n_ptr->bclink.supported);
1506 info("Acked: %u\n", n_ptr->bclink.acked);
1507 info("Last in: %u, ", n_ptr->bclink.last_in);
1508 info("Gap after: %u, ", n_ptr->bclink.gap_after);
1509 info("Gap to: %u\n", n_ptr->bclink.gap_to);
1510 info("Nack sync: %u\n\n", n_ptr->bclink.nack_sync);
1511
1512 tipc_k_signal((Handler)link_reset_all, (unsigned long)n_ptr->addr);
1513
1514 tipc_node_unlock(n_ptr);
1515
1516 l_ptr->stale_count = 0;
1517 }
1518 }
1519
1520 void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *buf,
1521 u32 retransmits)
1522 {
1523 struct tipc_msg *msg;
1524
1525 if (!buf)
1526 return;
1527
1528 msg = buf_msg(buf);
1529
1530 if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr)) {
1531 if (l_ptr->retransm_queue_size == 0) {
1532 l_ptr->retransm_queue_head = msg_seqno(msg);
1533 l_ptr->retransm_queue_size = retransmits;
1534 } else {
1535 err("Unexpected retransmit on link %s (qsize=%d)\n",
1536 l_ptr->name, l_ptr->retransm_queue_size);
1537 }
1538 return;
1539 } else {
1540 /* Detect repeated retransmit failures on uncongested bearer */
1541
1542 if (l_ptr->last_retransmitted == msg_seqno(msg)) {
1543 if (++l_ptr->stale_count > 100) {
1544 link_retransmit_failure(l_ptr, buf);
1545 return;
1546 }
1547 } else {
1548 l_ptr->last_retransmitted = msg_seqno(msg);
1549 l_ptr->stale_count = 1;
1550 }
1551 }
1552
1553 while (retransmits && (buf != l_ptr->next_out) && buf) {
1554 msg = buf_msg(buf);
1555 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1556 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1557 if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1558 buf = buf->next;
1559 retransmits--;
1560 l_ptr->stats.retransmitted++;
1561 } else {
1562 tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
1563 l_ptr->stats.bearer_congs++;
1564 l_ptr->retransm_queue_head = buf_seqno(buf);
1565 l_ptr->retransm_queue_size = retransmits;
1566 return;
1567 }
1568 }
1569
1570 l_ptr->retransm_queue_head = l_ptr->retransm_queue_size = 0;
1571 }
1572
1573 /**
1574 * link_insert_deferred_queue - insert deferred messages back into receive chain
1575 */
1576
1577 static struct sk_buff *link_insert_deferred_queue(struct tipc_link *l_ptr,
1578 struct sk_buff *buf)
1579 {
1580 u32 seq_no;
1581
1582 if (l_ptr->oldest_deferred_in == NULL)
1583 return buf;
1584
1585 seq_no = buf_seqno(l_ptr->oldest_deferred_in);
1586 if (seq_no == mod(l_ptr->next_in_no)) {
1587 l_ptr->newest_deferred_in->next = buf;
1588 buf = l_ptr->oldest_deferred_in;
1589 l_ptr->oldest_deferred_in = NULL;
1590 l_ptr->deferred_inqueue_sz = 0;
1591 }
1592 return buf;
1593 }
1594
1595 /**
1596 * link_recv_buf_validate - validate basic format of received message
1597 *
1598 * This routine ensures a TIPC message has an acceptable header, and at least
1599 * as much data as the header indicates it should. The routine also ensures
1600 * that the entire message header is stored in the main fragment of the message
1601 * buffer, to simplify future access to message header fields.
1602 *
1603 * Note: Having extra info present in the message header or data areas is OK.
1604 * TIPC will ignore the excess, under the assumption that it is optional info
1605 * introduced by a later release of the protocol.
1606 */
1607
1608 static int link_recv_buf_validate(struct sk_buff *buf)
1609 {
1610 static u32 min_data_hdr_size[8] = {
1611 SHORT_H_SIZE, MCAST_H_SIZE, NAMED_H_SIZE, BASIC_H_SIZE,
1612 MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE
1613 };
1614
1615 struct tipc_msg *msg;
1616 u32 tipc_hdr[2];
1617 u32 size;
1618 u32 hdr_size;
1619 u32 min_hdr_size;
1620
1621 if (unlikely(buf->len < MIN_H_SIZE))
1622 return 0;
1623
1624 msg = skb_header_pointer(buf, 0, sizeof(tipc_hdr), tipc_hdr);
1625 if (msg == NULL)
1626 return 0;
1627
1628 if (unlikely(msg_version(msg) != TIPC_VERSION))
1629 return 0;
1630
1631 size = msg_size(msg);
1632 hdr_size = msg_hdr_sz(msg);
1633 min_hdr_size = msg_isdata(msg) ?
1634 min_data_hdr_size[msg_type(msg)] : INT_H_SIZE;
1635
1636 if (unlikely((hdr_size < min_hdr_size) ||
1637 (size < hdr_size) ||
1638 (buf->len < size) ||
1639 (size - hdr_size > TIPC_MAX_USER_MSG_SIZE)))
1640 return 0;
1641
1642 return pskb_may_pull(buf, hdr_size);
1643 }
1644
1645 /**
1646 * tipc_recv_msg - process TIPC messages arriving from off-node
1647 * @head: pointer to message buffer chain
1648 * @tb_ptr: pointer to bearer message arrived on
1649 *
1650 * Invoked with no locks held. Bearer pointer must point to a valid bearer
1651 * structure (i.e. cannot be NULL), but bearer can be inactive.
1652 */
1653
1654 void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *b_ptr)
1655 {
1656 read_lock_bh(&tipc_net_lock);
1657 while (head) {
1658 struct tipc_node *n_ptr;
1659 struct tipc_link *l_ptr;
1660 struct sk_buff *crs;
1661 struct sk_buff *buf = head;
1662 struct tipc_msg *msg;
1663 u32 seq_no;
1664 u32 ackd;
1665 u32 released = 0;
1666 int type;
1667
1668 head = head->next;
1669
1670 /* Ensure bearer is still enabled */
1671
1672 if (unlikely(!b_ptr->active))
1673 goto cont;
1674
1675 /* Ensure message is well-formed */
1676
1677 if (unlikely(!link_recv_buf_validate(buf)))
1678 goto cont;
1679
1680 /* Ensure message data is a single contiguous unit */
1681
1682 if (unlikely(buf_linearize(buf)))
1683 goto cont;
1684
1685 /* Handle arrival of a non-unicast link message */
1686
1687 msg = buf_msg(buf);
1688
1689 if (unlikely(msg_non_seq(msg))) {
1690 if (msg_user(msg) == LINK_CONFIG)
1691 tipc_disc_recv_msg(buf, b_ptr);
1692 else
1693 tipc_bclink_recv_pkt(buf);
1694 continue;
1695 }
1696
1697 /* Discard unicast link messages destined for another node */
1698
1699 if (unlikely(!msg_short(msg) &&
1700 (msg_destnode(msg) != tipc_own_addr)))
1701 goto cont;
1702
1703 /* Locate neighboring node that sent message */
1704
1705 n_ptr = tipc_node_find(msg_prevnode(msg));
1706 if (unlikely(!n_ptr))
1707 goto cont;
1708 tipc_node_lock(n_ptr);
1709
1710 /* Locate unicast link endpoint that should handle message */
1711
1712 l_ptr = n_ptr->links[b_ptr->identity];
1713 if (unlikely(!l_ptr)) {
1714 tipc_node_unlock(n_ptr);
1715 goto cont;
1716 }
1717
1718 /* Verify that communication with node is currently allowed */
1719
1720 if ((n_ptr->block_setup & WAIT_PEER_DOWN) &&
1721 msg_user(msg) == LINK_PROTOCOL &&
1722 (msg_type(msg) == RESET_MSG ||
1723 msg_type(msg) == ACTIVATE_MSG) &&
1724 !msg_redundant_link(msg))
1725 n_ptr->block_setup &= ~WAIT_PEER_DOWN;
1726
1727 if (n_ptr->block_setup) {
1728 tipc_node_unlock(n_ptr);
1729 goto cont;
1730 }
1731
1732 /* Validate message sequence number info */
1733
1734 seq_no = msg_seqno(msg);
1735 ackd = msg_ack(msg);
1736
1737 /* Release acked messages */
1738
1739 if (tipc_node_is_up(n_ptr) && n_ptr->bclink.supported)
1740 tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
1741
1742 crs = l_ptr->first_out;
1743 while ((crs != l_ptr->next_out) &&
1744 less_eq(buf_seqno(crs), ackd)) {
1745 struct sk_buff *next = crs->next;
1746
1747 buf_discard(crs);
1748 crs = next;
1749 released++;
1750 }
1751 if (released) {
1752 l_ptr->first_out = crs;
1753 l_ptr->out_queue_size -= released;
1754 }
1755
1756 /* Try sending any messages link endpoint has pending */
1757
1758 if (unlikely(l_ptr->next_out))
1759 tipc_link_push_queue(l_ptr);
1760 if (unlikely(!list_empty(&l_ptr->waiting_ports)))
1761 tipc_link_wakeup_ports(l_ptr, 0);
1762 if (unlikely(++l_ptr->unacked_window >= TIPC_MIN_LINK_WIN)) {
1763 l_ptr->stats.sent_acks++;
1764 tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1765 }
1766
1767 /* Now (finally!) process the incoming message */
1768
1769 protocol_check:
1770 if (likely(link_working_working(l_ptr))) {
1771 if (likely(seq_no == mod(l_ptr->next_in_no))) {
1772 l_ptr->next_in_no++;
1773 if (unlikely(l_ptr->oldest_deferred_in))
1774 head = link_insert_deferred_queue(l_ptr,
1775 head);
1776 if (likely(msg_is_dest(msg, tipc_own_addr))) {
1777 deliver:
1778 if (likely(msg_isdata(msg))) {
1779 tipc_node_unlock(n_ptr);
1780 tipc_port_recv_msg(buf);
1781 continue;
1782 }
1783 switch (msg_user(msg)) {
1784 case MSG_BUNDLER:
1785 l_ptr->stats.recv_bundles++;
1786 l_ptr->stats.recv_bundled +=
1787 msg_msgcnt(msg);
1788 tipc_node_unlock(n_ptr);
1789 tipc_link_recv_bundle(buf);
1790 continue;
1791 case NAME_DISTRIBUTOR:
1792 tipc_node_unlock(n_ptr);
1793 tipc_named_recv(buf);
1794 continue;
1795 case CONN_MANAGER:
1796 tipc_node_unlock(n_ptr);
1797 tipc_port_recv_proto_msg(buf);
1798 continue;
1799 case MSG_FRAGMENTER:
1800 l_ptr->stats.recv_fragments++;
1801 if (tipc_link_recv_fragment(&l_ptr->defragm_buf,
1802 &buf, &msg)) {
1803 l_ptr->stats.recv_fragmented++;
1804 goto deliver;
1805 }
1806 break;
1807 case CHANGEOVER_PROTOCOL:
1808 type = msg_type(msg);
1809 if (link_recv_changeover_msg(&l_ptr, &buf)) {
1810 msg = buf_msg(buf);
1811 seq_no = msg_seqno(msg);
1812 if (type == ORIGINAL_MSG)
1813 goto deliver;
1814 goto protocol_check;
1815 }
1816 break;
1817 default:
1818 buf_discard(buf);
1819 buf = NULL;
1820 break;
1821 }
1822 }
1823 tipc_node_unlock(n_ptr);
1824 tipc_net_route_msg(buf);
1825 continue;
1826 }
1827 link_handle_out_of_seq_msg(l_ptr, buf);
1828 head = link_insert_deferred_queue(l_ptr, head);
1829 tipc_node_unlock(n_ptr);
1830 continue;
1831 }
1832
1833 if (msg_user(msg) == LINK_PROTOCOL) {
1834 link_recv_proto_msg(l_ptr, buf);
1835 head = link_insert_deferred_queue(l_ptr, head);
1836 tipc_node_unlock(n_ptr);
1837 continue;
1838 }
1839 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1840
1841 if (link_working_working(l_ptr)) {
1842 /* Re-insert in front of queue */
1843 buf->next = head;
1844 head = buf;
1845 tipc_node_unlock(n_ptr);
1846 continue;
1847 }
1848 tipc_node_unlock(n_ptr);
1849 cont:
1850 buf_discard(buf);
1851 }
1852 read_unlock_bh(&tipc_net_lock);
1853 }
1854
1855 /*
1856 * link_defer_buf(): Sort a received out-of-sequence packet
1857 * into the deferred reception queue.
1858 * Returns the increase of the queue length,i.e. 0 or 1
1859 */
1860
1861 u32 tipc_link_defer_pkt(struct sk_buff **head,
1862 struct sk_buff **tail,
1863 struct sk_buff *buf)
1864 {
1865 struct sk_buff *prev = NULL;
1866 struct sk_buff *crs = *head;
1867 u32 seq_no = buf_seqno(buf);
1868
1869 buf->next = NULL;
1870
1871 /* Empty queue ? */
1872 if (*head == NULL) {
1873 *head = *tail = buf;
1874 return 1;
1875 }
1876
1877 /* Last ? */
1878 if (less(buf_seqno(*tail), seq_no)) {
1879 (*tail)->next = buf;
1880 *tail = buf;
1881 return 1;
1882 }
1883
1884 /* Scan through queue and sort it in */
1885 do {
1886 struct tipc_msg *msg = buf_msg(crs);
1887
1888 if (less(seq_no, msg_seqno(msg))) {
1889 buf->next = crs;
1890 if (prev)
1891 prev->next = buf;
1892 else
1893 *head = buf;
1894 return 1;
1895 }
1896 if (seq_no == msg_seqno(msg))
1897 break;
1898 prev = crs;
1899 crs = crs->next;
1900 } while (crs);
1901
1902 /* Message is a duplicate of an existing message */
1903
1904 buf_discard(buf);
1905 return 0;
1906 }
1907
1908 /**
1909 * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
1910 */
1911
1912 static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
1913 struct sk_buff *buf)
1914 {
1915 u32 seq_no = buf_seqno(buf);
1916
1917 if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) {
1918 link_recv_proto_msg(l_ptr, buf);
1919 return;
1920 }
1921
1922 /* Record OOS packet arrival (force mismatch on next timeout) */
1923
1924 l_ptr->checkpoint--;
1925
1926 /*
1927 * Discard packet if a duplicate; otherwise add it to deferred queue
1928 * and notify peer of gap as per protocol specification
1929 */
1930
1931 if (less(seq_no, mod(l_ptr->next_in_no))) {
1932 l_ptr->stats.duplicates++;
1933 buf_discard(buf);
1934 return;
1935 }
1936
1937 if (tipc_link_defer_pkt(&l_ptr->oldest_deferred_in,
1938 &l_ptr->newest_deferred_in, buf)) {
1939 l_ptr->deferred_inqueue_sz++;
1940 l_ptr->stats.deferred_recv++;
1941 if ((l_ptr->deferred_inqueue_sz % 16) == 1)
1942 tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1943 } else
1944 l_ptr->stats.duplicates++;
1945 }
1946
1947 /*
1948 * Send protocol message to the other endpoint.
1949 */
1950 void tipc_link_send_proto_msg(struct tipc_link *l_ptr, u32 msg_typ,
1951 int probe_msg, u32 gap, u32 tolerance,
1952 u32 priority, u32 ack_mtu)
1953 {
1954 struct sk_buff *buf = NULL;
1955 struct tipc_msg *msg = l_ptr->pmsg;
1956 u32 msg_size = sizeof(l_ptr->proto_msg);
1957 int r_flag;
1958
1959 if (link_blocked(l_ptr))
1960 return;
1961
1962 /* Abort non-RESET send if communication with node is prohibited */
1963
1964 if ((l_ptr->owner->block_setup) && (msg_typ != RESET_MSG))
1965 return;
1966
1967 msg_set_type(msg, msg_typ);
1968 msg_set_net_plane(msg, l_ptr->b_ptr->net_plane);
1969 msg_set_bcast_ack(msg, mod(l_ptr->owner->bclink.last_in));
1970 msg_set_last_bcast(msg, tipc_bclink_get_last_sent());
1971
1972 if (msg_typ == STATE_MSG) {
1973 u32 next_sent = mod(l_ptr->next_out_no);
1974
1975 if (!tipc_link_is_up(l_ptr))
1976 return;
1977 if (l_ptr->next_out)
1978 next_sent = buf_seqno(l_ptr->next_out);
1979 msg_set_next_sent(msg, next_sent);
1980 if (l_ptr->oldest_deferred_in) {
1981 u32 rec = buf_seqno(l_ptr->oldest_deferred_in);
1982 gap = mod(rec - mod(l_ptr->next_in_no));
1983 }
1984 msg_set_seq_gap(msg, gap);
1985 if (gap)
1986 l_ptr->stats.sent_nacks++;
1987 msg_set_link_tolerance(msg, tolerance);
1988 msg_set_linkprio(msg, priority);
1989 msg_set_max_pkt(msg, ack_mtu);
1990 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1991 msg_set_probe(msg, probe_msg != 0);
1992 if (probe_msg) {
1993 u32 mtu = l_ptr->max_pkt;
1994
1995 if ((mtu < l_ptr->max_pkt_target) &&
1996 link_working_working(l_ptr) &&
1997 l_ptr->fsm_msg_cnt) {
1998 msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
1999 if (l_ptr->max_pkt_probes == 10) {
2000 l_ptr->max_pkt_target = (msg_size - 4);
2001 l_ptr->max_pkt_probes = 0;
2002 msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
2003 }
2004 l_ptr->max_pkt_probes++;
2005 }
2006
2007 l_ptr->stats.sent_probes++;
2008 }
2009 l_ptr->stats.sent_states++;
2010 } else { /* RESET_MSG or ACTIVATE_MSG */
2011 msg_set_ack(msg, mod(l_ptr->reset_checkpoint - 1));
2012 msg_set_seq_gap(msg, 0);
2013 msg_set_next_sent(msg, 1);
2014 msg_set_probe(msg, 0);
2015 msg_set_link_tolerance(msg, l_ptr->tolerance);
2016 msg_set_linkprio(msg, l_ptr->priority);
2017 msg_set_max_pkt(msg, l_ptr->max_pkt_target);
2018 }
2019
2020 r_flag = (l_ptr->owner->working_links > tipc_link_is_up(l_ptr));
2021 msg_set_redundant_link(msg, r_flag);
2022 msg_set_linkprio(msg, l_ptr->priority);
2023
2024 /* Ensure sequence number will not fit : */
2025
2026 msg_set_seqno(msg, mod(l_ptr->next_out_no + (0xffff/2)));
2027
2028 /* Congestion? */
2029
2030 if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr)) {
2031 if (!l_ptr->proto_msg_queue) {
2032 l_ptr->proto_msg_queue =
2033 tipc_buf_acquire(sizeof(l_ptr->proto_msg));
2034 }
2035 buf = l_ptr->proto_msg_queue;
2036 if (!buf)
2037 return;
2038 skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
2039 return;
2040 }
2041
2042 /* Message can be sent */
2043
2044 buf = tipc_buf_acquire(msg_size);
2045 if (!buf)
2046 return;
2047
2048 skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
2049 msg_set_size(buf_msg(buf), msg_size);
2050
2051 if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
2052 l_ptr->unacked_window = 0;
2053 buf_discard(buf);
2054 return;
2055 }
2056
2057 /* New congestion */
2058 tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
2059 l_ptr->proto_msg_queue = buf;
2060 l_ptr->stats.bearer_congs++;
2061 }
2062
2063 /*
2064 * Receive protocol message :
2065 * Note that network plane id propagates through the network, and may
2066 * change at any time. The node with lowest address rules
2067 */
2068
2069 static void link_recv_proto_msg(struct tipc_link *l_ptr, struct sk_buff *buf)
2070 {
2071 u32 rec_gap = 0;
2072 u32 max_pkt_info;
2073 u32 max_pkt_ack;
2074 u32 msg_tol;
2075 struct tipc_msg *msg = buf_msg(buf);
2076
2077 if (link_blocked(l_ptr))
2078 goto exit;
2079
2080 /* record unnumbered packet arrival (force mismatch on next timeout) */
2081
2082 l_ptr->checkpoint--;
2083
2084 if (l_ptr->b_ptr->net_plane != msg_net_plane(msg))
2085 if (tipc_own_addr > msg_prevnode(msg))
2086 l_ptr->b_ptr->net_plane = msg_net_plane(msg);
2087
2088 l_ptr->owner->permit_changeover = msg_redundant_link(msg);
2089
2090 switch (msg_type(msg)) {
2091
2092 case RESET_MSG:
2093 if (!link_working_unknown(l_ptr) &&
2094 (l_ptr->peer_session != INVALID_SESSION)) {
2095 if (less_eq(msg_session(msg), l_ptr->peer_session))
2096 break; /* duplicate or old reset: ignore */
2097 }
2098
2099 if (!msg_redundant_link(msg) && (link_working_working(l_ptr) ||
2100 link_working_unknown(l_ptr))) {
2101 /*
2102 * peer has lost contact -- don't allow peer's links
2103 * to reactivate before we recognize loss & clean up
2104 */
2105 l_ptr->owner->block_setup = WAIT_NODE_DOWN;
2106 }
2107
2108 /* fall thru' */
2109 case ACTIVATE_MSG:
2110 /* Update link settings according other endpoint's values */
2111
2112 strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg));
2113
2114 msg_tol = msg_link_tolerance(msg);
2115 if (msg_tol > l_ptr->tolerance)
2116 link_set_supervision_props(l_ptr, msg_tol);
2117
2118 if (msg_linkprio(msg) > l_ptr->priority)
2119 l_ptr->priority = msg_linkprio(msg);
2120
2121 max_pkt_info = msg_max_pkt(msg);
2122 if (max_pkt_info) {
2123 if (max_pkt_info < l_ptr->max_pkt_target)
2124 l_ptr->max_pkt_target = max_pkt_info;
2125 if (l_ptr->max_pkt > l_ptr->max_pkt_target)
2126 l_ptr->max_pkt = l_ptr->max_pkt_target;
2127 } else {
2128 l_ptr->max_pkt = l_ptr->max_pkt_target;
2129 }
2130 l_ptr->owner->bclink.supported = (max_pkt_info != 0);
2131
2132 link_state_event(l_ptr, msg_type(msg));
2133
2134 l_ptr->peer_session = msg_session(msg);
2135 l_ptr->peer_bearer_id = msg_bearer_id(msg);
2136
2137 /* Synchronize broadcast sequence numbers */
2138 if (!tipc_node_redundant_links(l_ptr->owner))
2139 l_ptr->owner->bclink.last_in = mod(msg_last_bcast(msg));
2140 break;
2141 case STATE_MSG:
2142
2143 msg_tol = msg_link_tolerance(msg);
2144 if (msg_tol)
2145 link_set_supervision_props(l_ptr, msg_tol);
2146
2147 if (msg_linkprio(msg) &&
2148 (msg_linkprio(msg) != l_ptr->priority)) {
2149 warn("Resetting link <%s>, priority change %u->%u\n",
2150 l_ptr->name, l_ptr->priority, msg_linkprio(msg));
2151 l_ptr->priority = msg_linkprio(msg);
2152 tipc_link_reset(l_ptr); /* Enforce change to take effect */
2153 break;
2154 }
2155 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
2156 l_ptr->stats.recv_states++;
2157 if (link_reset_unknown(l_ptr))
2158 break;
2159
2160 if (less_eq(mod(l_ptr->next_in_no), msg_next_sent(msg))) {
2161 rec_gap = mod(msg_next_sent(msg) -
2162 mod(l_ptr->next_in_no));
2163 }
2164
2165 max_pkt_ack = msg_max_pkt(msg);
2166 if (max_pkt_ack > l_ptr->max_pkt) {
2167 l_ptr->max_pkt = max_pkt_ack;
2168 l_ptr->max_pkt_probes = 0;
2169 }
2170
2171 max_pkt_ack = 0;
2172 if (msg_probe(msg)) {
2173 l_ptr->stats.recv_probes++;
2174 if (msg_size(msg) > sizeof(l_ptr->proto_msg))
2175 max_pkt_ack = msg_size(msg);
2176 }
2177
2178 /* Protocol message before retransmits, reduce loss risk */
2179
2180 tipc_bclink_check_gap(l_ptr->owner, msg_last_bcast(msg));
2181
2182 if (rec_gap || (msg_probe(msg))) {
2183 tipc_link_send_proto_msg(l_ptr, STATE_MSG,
2184 0, rec_gap, 0, 0, max_pkt_ack);
2185 }
2186 if (msg_seq_gap(msg)) {
2187 l_ptr->stats.recv_nacks++;
2188 tipc_link_retransmit(l_ptr, l_ptr->first_out,
2189 msg_seq_gap(msg));
2190 }
2191 break;
2192 }
2193 exit:
2194 buf_discard(buf);
2195 }
2196
2197
2198 /*
2199 * tipc_link_tunnel(): Send one message via a link belonging to
2200 * another bearer. Owner node is locked.
2201 */
2202 static void tipc_link_tunnel(struct tipc_link *l_ptr,
2203 struct tipc_msg *tunnel_hdr,
2204 struct tipc_msg *msg,
2205 u32 selector)
2206 {
2207 struct tipc_link *tunnel;
2208 struct sk_buff *buf;
2209 u32 length = msg_size(msg);
2210
2211 tunnel = l_ptr->owner->active_links[selector & 1];
2212 if (!tipc_link_is_up(tunnel)) {
2213 warn("Link changeover error, "
2214 "tunnel link no longer available\n");
2215 return;
2216 }
2217 msg_set_size(tunnel_hdr, length + INT_H_SIZE);
2218 buf = tipc_buf_acquire(length + INT_H_SIZE);
2219 if (!buf) {
2220 warn("Link changeover error, "
2221 "unable to send tunnel msg\n");
2222 return;
2223 }
2224 skb_copy_to_linear_data(buf, tunnel_hdr, INT_H_SIZE);
2225 skb_copy_to_linear_data_offset(buf, INT_H_SIZE, msg, length);
2226 tipc_link_send_buf(tunnel, buf);
2227 }
2228
2229
2230
2231 /*
2232 * changeover(): Send whole message queue via the remaining link
2233 * Owner node is locked.
2234 */
2235
2236 void tipc_link_changeover(struct tipc_link *l_ptr)
2237 {
2238 u32 msgcount = l_ptr->out_queue_size;
2239 struct sk_buff *crs = l_ptr->first_out;
2240 struct tipc_link *tunnel = l_ptr->owner->active_links[0];
2241 struct tipc_msg tunnel_hdr;
2242 int split_bundles;
2243
2244 if (!tunnel)
2245 return;
2246
2247 if (!l_ptr->owner->permit_changeover) {
2248 warn("Link changeover error, "
2249 "peer did not permit changeover\n");
2250 return;
2251 }
2252
2253 tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
2254 ORIGINAL_MSG, INT_H_SIZE, l_ptr->addr);
2255 msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
2256 msg_set_msgcnt(&tunnel_hdr, msgcount);
2257
2258 if (!l_ptr->first_out) {
2259 struct sk_buff *buf;
2260
2261 buf = tipc_buf_acquire(INT_H_SIZE);
2262 if (buf) {
2263 skb_copy_to_linear_data(buf, &tunnel_hdr, INT_H_SIZE);
2264 msg_set_size(&tunnel_hdr, INT_H_SIZE);
2265 tipc_link_send_buf(tunnel, buf);
2266 } else {
2267 warn("Link changeover error, "
2268 "unable to send changeover msg\n");
2269 }
2270 return;
2271 }
2272
2273 split_bundles = (l_ptr->owner->active_links[0] !=
2274 l_ptr->owner->active_links[1]);
2275
2276 while (crs) {
2277 struct tipc_msg *msg = buf_msg(crs);
2278
2279 if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
2280 struct tipc_msg *m = msg_get_wrapped(msg);
2281 unchar *pos = (unchar *)m;
2282
2283 msgcount = msg_msgcnt(msg);
2284 while (msgcount--) {
2285 msg_set_seqno(m, msg_seqno(msg));
2286 tipc_link_tunnel(l_ptr, &tunnel_hdr, m,
2287 msg_link_selector(m));
2288 pos += align(msg_size(m));
2289 m = (struct tipc_msg *)pos;
2290 }
2291 } else {
2292 tipc_link_tunnel(l_ptr, &tunnel_hdr, msg,
2293 msg_link_selector(msg));
2294 }
2295 crs = crs->next;
2296 }
2297 }
2298
2299 void tipc_link_send_duplicate(struct tipc_link *l_ptr, struct tipc_link *tunnel)
2300 {
2301 struct sk_buff *iter;
2302 struct tipc_msg tunnel_hdr;
2303
2304 tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
2305 DUPLICATE_MSG, INT_H_SIZE, l_ptr->addr);
2306 msg_set_msgcnt(&tunnel_hdr, l_ptr->out_queue_size);
2307 msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
2308 iter = l_ptr->first_out;
2309 while (iter) {
2310 struct sk_buff *outbuf;
2311 struct tipc_msg *msg = buf_msg(iter);
2312 u32 length = msg_size(msg);
2313
2314 if (msg_user(msg) == MSG_BUNDLER)
2315 msg_set_type(msg, CLOSED_MSG);
2316 msg_set_ack(msg, mod(l_ptr->next_in_no - 1)); /* Update */
2317 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
2318 msg_set_size(&tunnel_hdr, length + INT_H_SIZE);
2319 outbuf = tipc_buf_acquire(length + INT_H_SIZE);
2320 if (outbuf == NULL) {
2321 warn("Link changeover error, "
2322 "unable to send duplicate msg\n");
2323 return;
2324 }
2325 skb_copy_to_linear_data(outbuf, &tunnel_hdr, INT_H_SIZE);
2326 skb_copy_to_linear_data_offset(outbuf, INT_H_SIZE, iter->data,
2327 length);
2328 tipc_link_send_buf(tunnel, outbuf);
2329 if (!tipc_link_is_up(l_ptr))
2330 return;
2331 iter = iter->next;
2332 }
2333 }
2334
2335
2336
2337 /**
2338 * buf_extract - extracts embedded TIPC message from another message
2339 * @skb: encapsulating message buffer
2340 * @from_pos: offset to extract from
2341 *
2342 * Returns a new message buffer containing an embedded message. The
2343 * encapsulating message itself is left unchanged.
2344 */
2345
2346 static struct sk_buff *buf_extract(struct sk_buff *skb, u32 from_pos)
2347 {
2348 struct tipc_msg *msg = (struct tipc_msg *)(skb->data + from_pos);
2349 u32 size = msg_size(msg);
2350 struct sk_buff *eb;
2351
2352 eb = tipc_buf_acquire(size);
2353 if (eb)
2354 skb_copy_to_linear_data(eb, msg, size);
2355 return eb;
2356 }
2357
2358 /*
2359 * link_recv_changeover_msg(): Receive tunneled packet sent
2360 * via other link. Node is locked. Return extracted buffer.
2361 */
2362
2363 static int link_recv_changeover_msg(struct tipc_link **l_ptr,
2364 struct sk_buff **buf)
2365 {
2366 struct sk_buff *tunnel_buf = *buf;
2367 struct tipc_link *dest_link;
2368 struct tipc_msg *msg;
2369 struct tipc_msg *tunnel_msg = buf_msg(tunnel_buf);
2370 u32 msg_typ = msg_type(tunnel_msg);
2371 u32 msg_count = msg_msgcnt(tunnel_msg);
2372
2373 dest_link = (*l_ptr)->owner->links[msg_bearer_id(tunnel_msg)];
2374 if (!dest_link)
2375 goto exit;
2376 if (dest_link == *l_ptr) {
2377 err("Unexpected changeover message on link <%s>\n",
2378 (*l_ptr)->name);
2379 goto exit;
2380 }
2381 *l_ptr = dest_link;
2382 msg = msg_get_wrapped(tunnel_msg);
2383
2384 if (msg_typ == DUPLICATE_MSG) {
2385 if (less(msg_seqno(msg), mod(dest_link->next_in_no)))
2386 goto exit;
2387 *buf = buf_extract(tunnel_buf, INT_H_SIZE);
2388 if (*buf == NULL) {
2389 warn("Link changeover error, duplicate msg dropped\n");
2390 goto exit;
2391 }
2392 buf_discard(tunnel_buf);
2393 return 1;
2394 }
2395
2396 /* First original message ?: */
2397
2398 if (tipc_link_is_up(dest_link)) {
2399 info("Resetting link <%s>, changeover initiated by peer\n",
2400 dest_link->name);
2401 tipc_link_reset(dest_link);
2402 dest_link->exp_msg_count = msg_count;
2403 if (!msg_count)
2404 goto exit;
2405 } else if (dest_link->exp_msg_count == START_CHANGEOVER) {
2406 dest_link->exp_msg_count = msg_count;
2407 if (!msg_count)
2408 goto exit;
2409 }
2410
2411 /* Receive original message */
2412
2413 if (dest_link->exp_msg_count == 0) {
2414 warn("Link switchover error, "
2415 "got too many tunnelled messages\n");
2416 goto exit;
2417 }
2418 dest_link->exp_msg_count--;
2419 if (less(msg_seqno(msg), dest_link->reset_checkpoint)) {
2420 goto exit;
2421 } else {
2422 *buf = buf_extract(tunnel_buf, INT_H_SIZE);
2423 if (*buf != NULL) {
2424 buf_discard(tunnel_buf);
2425 return 1;
2426 } else {
2427 warn("Link changeover error, original msg dropped\n");
2428 }
2429 }
2430 exit:
2431 *buf = NULL;
2432 buf_discard(tunnel_buf);
2433 return 0;
2434 }
2435
2436 /*
2437 * Bundler functionality:
2438 */
2439 void tipc_link_recv_bundle(struct sk_buff *buf)
2440 {
2441 u32 msgcount = msg_msgcnt(buf_msg(buf));
2442 u32 pos = INT_H_SIZE;
2443 struct sk_buff *obuf;
2444
2445 while (msgcount--) {
2446 obuf = buf_extract(buf, pos);
2447 if (obuf == NULL) {
2448 warn("Link unable to unbundle message(s)\n");
2449 break;
2450 }
2451 pos += align(msg_size(buf_msg(obuf)));
2452 tipc_net_route_msg(obuf);
2453 }
2454 buf_discard(buf);
2455 }
2456
2457 /*
2458 * Fragmentation/defragmentation:
2459 */
2460
2461
2462 /*
2463 * link_send_long_buf: Entry for buffers needing fragmentation.
2464 * The buffer is complete, inclusive total message length.
2465 * Returns user data length.
2466 */
2467 static int link_send_long_buf(struct tipc_link *l_ptr, struct sk_buff *buf)
2468 {
2469 struct sk_buff *buf_chain = NULL;
2470 struct sk_buff *buf_chain_tail = (struct sk_buff *)&buf_chain;
2471 struct tipc_msg *inmsg = buf_msg(buf);
2472 struct tipc_msg fragm_hdr;
2473 u32 insize = msg_size(inmsg);
2474 u32 dsz = msg_data_sz(inmsg);
2475 unchar *crs = buf->data;
2476 u32 rest = insize;
2477 u32 pack_sz = l_ptr->max_pkt;
2478 u32 fragm_sz = pack_sz - INT_H_SIZE;
2479 u32 fragm_no = 0;
2480 u32 destaddr;
2481
2482 if (msg_short(inmsg))
2483 destaddr = l_ptr->addr;
2484 else
2485 destaddr = msg_destnode(inmsg);
2486
2487 /* Prepare reusable fragment header: */
2488
2489 tipc_msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
2490 INT_H_SIZE, destaddr);
2491
2492 /* Chop up message: */
2493
2494 while (rest > 0) {
2495 struct sk_buff *fragm;
2496
2497 if (rest <= fragm_sz) {
2498 fragm_sz = rest;
2499 msg_set_type(&fragm_hdr, LAST_FRAGMENT);
2500 }
2501 fragm = tipc_buf_acquire(fragm_sz + INT_H_SIZE);
2502 if (fragm == NULL) {
2503 buf_discard(buf);
2504 while (buf_chain) {
2505 buf = buf_chain;
2506 buf_chain = buf_chain->next;
2507 buf_discard(buf);
2508 }
2509 return -ENOMEM;
2510 }
2511 msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
2512 fragm_no++;
2513 msg_set_fragm_no(&fragm_hdr, fragm_no);
2514 skb_copy_to_linear_data(fragm, &fragm_hdr, INT_H_SIZE);
2515 skb_copy_to_linear_data_offset(fragm, INT_H_SIZE, crs,
2516 fragm_sz);
2517 buf_chain_tail->next = fragm;
2518 buf_chain_tail = fragm;
2519
2520 rest -= fragm_sz;
2521 crs += fragm_sz;
2522 msg_set_type(&fragm_hdr, FRAGMENT);
2523 }
2524 buf_discard(buf);
2525
2526 /* Append chain of fragments to send queue & send them */
2527
2528 l_ptr->long_msg_seq_no++;
2529 link_add_chain_to_outqueue(l_ptr, buf_chain, l_ptr->long_msg_seq_no);
2530 l_ptr->stats.sent_fragments += fragm_no;
2531 l_ptr->stats.sent_fragmented++;
2532 tipc_link_push_queue(l_ptr);
2533
2534 return dsz;
2535 }
2536
2537 /*
2538 * A pending message being re-assembled must store certain values
2539 * to handle subsequent fragments correctly. The following functions
2540 * help storing these values in unused, available fields in the
2541 * pending message. This makes dynamic memory allocation unnecessary.
2542 */
2543
2544 static void set_long_msg_seqno(struct sk_buff *buf, u32 seqno)
2545 {
2546 msg_set_seqno(buf_msg(buf), seqno);
2547 }
2548
2549 static u32 get_fragm_size(struct sk_buff *buf)
2550 {
2551 return msg_ack(buf_msg(buf));
2552 }
2553
2554 static void set_fragm_size(struct sk_buff *buf, u32 sz)
2555 {
2556 msg_set_ack(buf_msg(buf), sz);
2557 }
2558
2559 static u32 get_expected_frags(struct sk_buff *buf)
2560 {
2561 return msg_bcast_ack(buf_msg(buf));
2562 }
2563
2564 static void set_expected_frags(struct sk_buff *buf, u32 exp)
2565 {
2566 msg_set_bcast_ack(buf_msg(buf), exp);
2567 }
2568
2569 static u32 get_timer_cnt(struct sk_buff *buf)
2570 {
2571 return msg_reroute_cnt(buf_msg(buf));
2572 }
2573
2574 static void incr_timer_cnt(struct sk_buff *buf)
2575 {
2576 msg_incr_reroute_cnt(buf_msg(buf));
2577 }
2578
2579 /*
2580 * tipc_link_recv_fragment(): Called with node lock on. Returns
2581 * the reassembled buffer if message is complete.
2582 */
2583 int tipc_link_recv_fragment(struct sk_buff **pending, struct sk_buff **fb,
2584 struct tipc_msg **m)
2585 {
2586 struct sk_buff *prev = NULL;
2587 struct sk_buff *fbuf = *fb;
2588 struct tipc_msg *fragm = buf_msg(fbuf);
2589 struct sk_buff *pbuf = *pending;
2590 u32 long_msg_seq_no = msg_long_msgno(fragm);
2591
2592 *fb = NULL;
2593
2594 /* Is there an incomplete message waiting for this fragment? */
2595
2596 while (pbuf && ((buf_seqno(pbuf) != long_msg_seq_no) ||
2597 (msg_orignode(fragm) != msg_orignode(buf_msg(pbuf))))) {
2598 prev = pbuf;
2599 pbuf = pbuf->next;
2600 }
2601
2602 if (!pbuf && (msg_type(fragm) == FIRST_FRAGMENT)) {
2603 struct tipc_msg *imsg = (struct tipc_msg *)msg_data(fragm);
2604 u32 msg_sz = msg_size(imsg);
2605 u32 fragm_sz = msg_data_sz(fragm);
2606 u32 exp_fragm_cnt = msg_sz/fragm_sz + !!(msg_sz % fragm_sz);
2607 u32 max = TIPC_MAX_USER_MSG_SIZE + NAMED_H_SIZE;
2608 if (msg_type(imsg) == TIPC_MCAST_MSG)
2609 max = TIPC_MAX_USER_MSG_SIZE + MCAST_H_SIZE;
2610 if (msg_size(imsg) > max) {
2611 buf_discard(fbuf);
2612 return 0;
2613 }
2614 pbuf = tipc_buf_acquire(msg_size(imsg));
2615 if (pbuf != NULL) {
2616 pbuf->next = *pending;
2617 *pending = pbuf;
2618 skb_copy_to_linear_data(pbuf, imsg,
2619 msg_data_sz(fragm));
2620 /* Prepare buffer for subsequent fragments. */
2621
2622 set_long_msg_seqno(pbuf, long_msg_seq_no);
2623 set_fragm_size(pbuf, fragm_sz);
2624 set_expected_frags(pbuf, exp_fragm_cnt - 1);
2625 } else {
2626 warn("Link unable to reassemble fragmented message\n");
2627 }
2628 buf_discard(fbuf);
2629 return 0;
2630 } else if (pbuf && (msg_type(fragm) != FIRST_FRAGMENT)) {
2631 u32 dsz = msg_data_sz(fragm);
2632 u32 fsz = get_fragm_size(pbuf);
2633 u32 crs = ((msg_fragm_no(fragm) - 1) * fsz);
2634 u32 exp_frags = get_expected_frags(pbuf) - 1;
2635 skb_copy_to_linear_data_offset(pbuf, crs,
2636 msg_data(fragm), dsz);
2637 buf_discard(fbuf);
2638
2639 /* Is message complete? */
2640
2641 if (exp_frags == 0) {
2642 if (prev)
2643 prev->next = pbuf->next;
2644 else
2645 *pending = pbuf->next;
2646 msg_reset_reroute_cnt(buf_msg(pbuf));
2647 *fb = pbuf;
2648 *m = buf_msg(pbuf);
2649 return 1;
2650 }
2651 set_expected_frags(pbuf, exp_frags);
2652 return 0;
2653 }
2654 buf_discard(fbuf);
2655 return 0;
2656 }
2657
2658 /**
2659 * link_check_defragm_bufs - flush stale incoming message fragments
2660 * @l_ptr: pointer to link
2661 */
2662
2663 static void link_check_defragm_bufs(struct tipc_link *l_ptr)
2664 {
2665 struct sk_buff *prev = NULL;
2666 struct sk_buff *next = NULL;
2667 struct sk_buff *buf = l_ptr->defragm_buf;
2668
2669 if (!buf)
2670 return;
2671 if (!link_working_working(l_ptr))
2672 return;
2673 while (buf) {
2674 u32 cnt = get_timer_cnt(buf);
2675
2676 next = buf->next;
2677 if (cnt < 4) {
2678 incr_timer_cnt(buf);
2679 prev = buf;
2680 } else {
2681 if (prev)
2682 prev->next = buf->next;
2683 else
2684 l_ptr->defragm_buf = buf->next;
2685 buf_discard(buf);
2686 }
2687 buf = next;
2688 }
2689 }
2690
2691
2692
2693 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance)
2694 {
2695 if ((tolerance < TIPC_MIN_LINK_TOL) || (tolerance > TIPC_MAX_LINK_TOL))
2696 return;
2697
2698 l_ptr->tolerance = tolerance;
2699 l_ptr->continuity_interval =
2700 ((tolerance / 4) > 500) ? 500 : tolerance / 4;
2701 l_ptr->abort_limit = tolerance / (l_ptr->continuity_interval / 4);
2702 }
2703
2704
2705 void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window)
2706 {
2707 /* Data messages from this node, inclusive FIRST_FRAGM */
2708 l_ptr->queue_limit[TIPC_LOW_IMPORTANCE] = window;
2709 l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE] = (window / 3) * 4;
2710 l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE] = (window / 3) * 5;
2711 l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE] = (window / 3) * 6;
2712 /* Transiting data messages,inclusive FIRST_FRAGM */
2713 l_ptr->queue_limit[TIPC_LOW_IMPORTANCE + 4] = 300;
2714 l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE + 4] = 600;
2715 l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE + 4] = 900;
2716 l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE + 4] = 1200;
2717 l_ptr->queue_limit[CONN_MANAGER] = 1200;
2718 l_ptr->queue_limit[CHANGEOVER_PROTOCOL] = 2500;
2719 l_ptr->queue_limit[NAME_DISTRIBUTOR] = 3000;
2720 /* FRAGMENT and LAST_FRAGMENT packets */
2721 l_ptr->queue_limit[MSG_FRAGMENTER] = 4000;
2722 }
2723
2724 /**
2725 * link_find_link - locate link by name
2726 * @name - ptr to link name string
2727 * @node - ptr to area to be filled with ptr to associated node
2728 *
2729 * Caller must hold 'tipc_net_lock' to ensure node and bearer are not deleted;
2730 * this also prevents link deletion.
2731 *
2732 * Returns pointer to link (or 0 if invalid link name).
2733 */
2734
2735 static struct tipc_link *link_find_link(const char *name,
2736 struct tipc_node **node)
2737 {
2738 struct tipc_link_name link_name_parts;
2739 struct tipc_bearer *b_ptr;
2740 struct tipc_link *l_ptr;
2741
2742 if (!link_name_validate(name, &link_name_parts))
2743 return NULL;
2744
2745 b_ptr = tipc_bearer_find_interface(link_name_parts.if_local);
2746 if (!b_ptr)
2747 return NULL;
2748
2749 *node = tipc_node_find(link_name_parts.addr_peer);
2750 if (!*node)
2751 return NULL;
2752
2753 l_ptr = (*node)->links[b_ptr->identity];
2754 if (!l_ptr || strcmp(l_ptr->name, name))
2755 return NULL;
2756
2757 return l_ptr;
2758 }
2759
2760 /**
2761 * link_value_is_valid -- validate proposed link tolerance/priority/window
2762 *
2763 * @cmd - value type (TIPC_CMD_SET_LINK_*)
2764 * @new_value - the new value
2765 *
2766 * Returns 1 if value is within range, 0 if not.
2767 */
2768
2769 static int link_value_is_valid(u16 cmd, u32 new_value)
2770 {
2771 switch (cmd) {
2772 case TIPC_CMD_SET_LINK_TOL:
2773 return (new_value >= TIPC_MIN_LINK_TOL) &&
2774 (new_value <= TIPC_MAX_LINK_TOL);
2775 case TIPC_CMD_SET_LINK_PRI:
2776 return (new_value <= TIPC_MAX_LINK_PRI);
2777 case TIPC_CMD_SET_LINK_WINDOW:
2778 return (new_value >= TIPC_MIN_LINK_WIN) &&
2779 (new_value <= TIPC_MAX_LINK_WIN);
2780 }
2781 return 0;
2782 }
2783
2784
2785 /**
2786 * link_cmd_set_value - change priority/tolerance/window for link/bearer/media
2787 * @name - ptr to link, bearer, or media name
2788 * @new_value - new value of link, bearer, or media setting
2789 * @cmd - which link, bearer, or media attribute to set (TIPC_CMD_SET_LINK_*)
2790 *
2791 * Caller must hold 'tipc_net_lock' to ensure link/bearer/media is not deleted.
2792 *
2793 * Returns 0 if value updated and negative value on error.
2794 */
2795
2796 static int link_cmd_set_value(const char *name, u32 new_value, u16 cmd)
2797 {
2798 struct tipc_node *node;
2799 struct tipc_link *l_ptr;
2800 struct tipc_bearer *b_ptr;
2801 struct tipc_media *m_ptr;
2802
2803 l_ptr = link_find_link(name, &node);
2804 if (l_ptr) {
2805 /*
2806 * acquire node lock for tipc_link_send_proto_msg().
2807 * see "TIPC locking policy" in net.c.
2808 */
2809 tipc_node_lock(node);
2810 switch (cmd) {
2811 case TIPC_CMD_SET_LINK_TOL:
2812 link_set_supervision_props(l_ptr, new_value);
2813 tipc_link_send_proto_msg(l_ptr,
2814 STATE_MSG, 0, 0, new_value, 0, 0);
2815 break;
2816 case TIPC_CMD_SET_LINK_PRI:
2817 l_ptr->priority = new_value;
2818 tipc_link_send_proto_msg(l_ptr,
2819 STATE_MSG, 0, 0, 0, new_value, 0);
2820 break;
2821 case TIPC_CMD_SET_LINK_WINDOW:
2822 tipc_link_set_queue_limits(l_ptr, new_value);
2823 break;
2824 }
2825 tipc_node_unlock(node);
2826 return 0;
2827 }
2828
2829 b_ptr = tipc_bearer_find(name);
2830 if (b_ptr) {
2831 switch (cmd) {
2832 case TIPC_CMD_SET_LINK_TOL:
2833 b_ptr->tolerance = new_value;
2834 return 0;
2835 case TIPC_CMD_SET_LINK_PRI:
2836 b_ptr->priority = new_value;
2837 return 0;
2838 case TIPC_CMD_SET_LINK_WINDOW:
2839 b_ptr->window = new_value;
2840 return 0;
2841 }
2842 return -EINVAL;
2843 }
2844
2845 m_ptr = tipc_media_find(name);
2846 if (!m_ptr)
2847 return -ENODEV;
2848 switch (cmd) {
2849 case TIPC_CMD_SET_LINK_TOL:
2850 m_ptr->tolerance = new_value;
2851 return 0;
2852 case TIPC_CMD_SET_LINK_PRI:
2853 m_ptr->priority = new_value;
2854 return 0;
2855 case TIPC_CMD_SET_LINK_WINDOW:
2856 m_ptr->window = new_value;
2857 return 0;
2858 }
2859 return -EINVAL;
2860 }
2861
2862 struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space,
2863 u16 cmd)
2864 {
2865 struct tipc_link_config *args;
2866 u32 new_value;
2867 int res;
2868
2869 if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_CONFIG))
2870 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2871
2872 args = (struct tipc_link_config *)TLV_DATA(req_tlv_area);
2873 new_value = ntohl(args->value);
2874
2875 if (!link_value_is_valid(cmd, new_value))
2876 return tipc_cfg_reply_error_string(
2877 "cannot change, value invalid");
2878
2879 if (!strcmp(args->name, tipc_bclink_name)) {
2880 if ((cmd == TIPC_CMD_SET_LINK_WINDOW) &&
2881 (tipc_bclink_set_queue_limits(new_value) == 0))
2882 return tipc_cfg_reply_none();
2883 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
2884 " (cannot change setting on broadcast link)");
2885 }
2886
2887 read_lock_bh(&tipc_net_lock);
2888 res = link_cmd_set_value(args->name, new_value, cmd);
2889 read_unlock_bh(&tipc_net_lock);
2890 if (res)
2891 return tipc_cfg_reply_error_string("cannot change link setting");
2892
2893 return tipc_cfg_reply_none();
2894 }
2895
2896 /**
2897 * link_reset_statistics - reset link statistics
2898 * @l_ptr: pointer to link
2899 */
2900
2901 static void link_reset_statistics(struct tipc_link *l_ptr)
2902 {
2903 memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
2904 l_ptr->stats.sent_info = l_ptr->next_out_no;
2905 l_ptr->stats.recv_info = l_ptr->next_in_no;
2906 }
2907
2908 struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space)
2909 {
2910 char *link_name;
2911 struct tipc_link *l_ptr;
2912 struct tipc_node *node;
2913
2914 if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
2915 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2916
2917 link_name = (char *)TLV_DATA(req_tlv_area);
2918 if (!strcmp(link_name, tipc_bclink_name)) {
2919 if (tipc_bclink_reset_stats())
2920 return tipc_cfg_reply_error_string("link not found");
2921 return tipc_cfg_reply_none();
2922 }
2923
2924 read_lock_bh(&tipc_net_lock);
2925 l_ptr = link_find_link(link_name, &node);
2926 if (!l_ptr) {
2927 read_unlock_bh(&tipc_net_lock);
2928 return tipc_cfg_reply_error_string("link not found");
2929 }
2930
2931 tipc_node_lock(node);
2932 link_reset_statistics(l_ptr);
2933 tipc_node_unlock(node);
2934 read_unlock_bh(&tipc_net_lock);
2935 return tipc_cfg_reply_none();
2936 }
2937
2938 /**
2939 * percent - convert count to a percentage of total (rounding up or down)
2940 */
2941
2942 static u32 percent(u32 count, u32 total)
2943 {
2944 return (count * 100 + (total / 2)) / total;
2945 }
2946
2947 /**
2948 * tipc_link_stats - print link statistics
2949 * @name: link name
2950 * @buf: print buffer area
2951 * @buf_size: size of print buffer area
2952 *
2953 * Returns length of print buffer data string (or 0 if error)
2954 */
2955
2956 static int tipc_link_stats(const char *name, char *buf, const u32 buf_size)
2957 {
2958 struct print_buf pb;
2959 struct tipc_link *l_ptr;
2960 struct tipc_node *node;
2961 char *status;
2962 u32 profile_total = 0;
2963
2964 if (!strcmp(name, tipc_bclink_name))
2965 return tipc_bclink_stats(buf, buf_size);
2966
2967 tipc_printbuf_init(&pb, buf, buf_size);
2968
2969 read_lock_bh(&tipc_net_lock);
2970 l_ptr = link_find_link(name, &node);
2971 if (!l_ptr) {
2972 read_unlock_bh(&tipc_net_lock);
2973 return 0;
2974 }
2975 tipc_node_lock(node);
2976
2977 if (tipc_link_is_active(l_ptr))
2978 status = "ACTIVE";
2979 else if (tipc_link_is_up(l_ptr))
2980 status = "STANDBY";
2981 else
2982 status = "DEFUNCT";
2983 tipc_printf(&pb, "Link <%s>\n"
2984 " %s MTU:%u Priority:%u Tolerance:%u ms"
2985 " Window:%u packets\n",
2986 l_ptr->name, status, l_ptr->max_pkt,
2987 l_ptr->priority, l_ptr->tolerance, l_ptr->queue_limit[0]);
2988 tipc_printf(&pb, " RX packets:%u fragments:%u/%u bundles:%u/%u\n",
2989 l_ptr->next_in_no - l_ptr->stats.recv_info,
2990 l_ptr->stats.recv_fragments,
2991 l_ptr->stats.recv_fragmented,
2992 l_ptr->stats.recv_bundles,
2993 l_ptr->stats.recv_bundled);
2994 tipc_printf(&pb, " TX packets:%u fragments:%u/%u bundles:%u/%u\n",
2995 l_ptr->next_out_no - l_ptr->stats.sent_info,
2996 l_ptr->stats.sent_fragments,
2997 l_ptr->stats.sent_fragmented,
2998 l_ptr->stats.sent_bundles,
2999 l_ptr->stats.sent_bundled);
3000 profile_total = l_ptr->stats.msg_length_counts;
3001 if (!profile_total)
3002 profile_total = 1;
3003 tipc_printf(&pb, " TX profile sample:%u packets average:%u octets\n"
3004 " 0-64:%u%% -256:%u%% -1024:%u%% -4096:%u%% "
3005 "-16384:%u%% -32768:%u%% -66000:%u%%\n",
3006 l_ptr->stats.msg_length_counts,
3007 l_ptr->stats.msg_lengths_total / profile_total,
3008 percent(l_ptr->stats.msg_length_profile[0], profile_total),
3009 percent(l_ptr->stats.msg_length_profile[1], profile_total),
3010 percent(l_ptr->stats.msg_length_profile[2], profile_total),
3011 percent(l_ptr->stats.msg_length_profile[3], profile_total),
3012 percent(l_ptr->stats.msg_length_profile[4], profile_total),
3013 percent(l_ptr->stats.msg_length_profile[5], profile_total),
3014 percent(l_ptr->stats.msg_length_profile[6], profile_total));
3015 tipc_printf(&pb, " RX states:%u probes:%u naks:%u defs:%u dups:%u\n",
3016 l_ptr->stats.recv_states,
3017 l_ptr->stats.recv_probes,
3018 l_ptr->stats.recv_nacks,
3019 l_ptr->stats.deferred_recv,
3020 l_ptr->stats.duplicates);
3021 tipc_printf(&pb, " TX states:%u probes:%u naks:%u acks:%u dups:%u\n",
3022 l_ptr->stats.sent_states,
3023 l_ptr->stats.sent_probes,
3024 l_ptr->stats.sent_nacks,
3025 l_ptr->stats.sent_acks,
3026 l_ptr->stats.retransmitted);
3027 tipc_printf(&pb, " Congestion bearer:%u link:%u Send queue max:%u avg:%u\n",
3028 l_ptr->stats.bearer_congs,
3029 l_ptr->stats.link_congs,
3030 l_ptr->stats.max_queue_sz,
3031 l_ptr->stats.queue_sz_counts
3032 ? (l_ptr->stats.accu_queue_sz / l_ptr->stats.queue_sz_counts)
3033 : 0);
3034
3035 tipc_node_unlock(node);
3036 read_unlock_bh(&tipc_net_lock);
3037 return tipc_printbuf_validate(&pb);
3038 }
3039
3040 #define MAX_LINK_STATS_INFO 2000
3041
3042 struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space)
3043 {
3044 struct sk_buff *buf;
3045 struct tlv_desc *rep_tlv;
3046 int str_len;
3047
3048 if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
3049 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
3050
3051 buf = tipc_cfg_reply_alloc(TLV_SPACE(MAX_LINK_STATS_INFO));
3052 if (!buf)
3053 return NULL;
3054
3055 rep_tlv = (struct tlv_desc *)buf->data;
3056
3057 str_len = tipc_link_stats((char *)TLV_DATA(req_tlv_area),
3058 (char *)TLV_DATA(rep_tlv), MAX_LINK_STATS_INFO);
3059 if (!str_len) {
3060 buf_discard(buf);
3061 return tipc_cfg_reply_error_string("link not found");
3062 }
3063
3064 skb_put(buf, TLV_SPACE(str_len));
3065 TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
3066
3067 return buf;
3068 }
3069
3070 /**
3071 * tipc_link_get_max_pkt - get maximum packet size to use when sending to destination
3072 * @dest: network address of destination node
3073 * @selector: used to select from set of active links
3074 *
3075 * If no active link can be found, uses default maximum packet size.
3076 */
3077
3078 u32 tipc_link_get_max_pkt(u32 dest, u32 selector)
3079 {
3080 struct tipc_node *n_ptr;
3081 struct tipc_link *l_ptr;
3082 u32 res = MAX_PKT_DEFAULT;
3083
3084 if (dest == tipc_own_addr)
3085 return MAX_MSG_SIZE;
3086
3087 read_lock_bh(&tipc_net_lock);
3088 n_ptr = tipc_node_find(dest);
3089 if (n_ptr) {
3090 tipc_node_lock(n_ptr);
3091 l_ptr = n_ptr->active_links[selector & 1];
3092 if (l_ptr)
3093 res = l_ptr->max_pkt;
3094 tipc_node_unlock(n_ptr);
3095 }
3096 read_unlock_bh(&tipc_net_lock);
3097 return res;
3098 }
3099
3100 static void link_print(struct tipc_link *l_ptr, const char *str)
3101 {
3102 char print_area[256];
3103 struct print_buf pb;
3104 struct print_buf *buf = &pb;
3105
3106 tipc_printbuf_init(buf, print_area, sizeof(print_area));
3107
3108 tipc_printf(buf, str);
3109 tipc_printf(buf, "Link %x<%s>:",
3110 l_ptr->addr, l_ptr->b_ptr->name);
3111
3112 #ifdef CONFIG_TIPC_DEBUG
3113 if (link_reset_reset(l_ptr) || link_reset_unknown(l_ptr))
3114 goto print_state;
3115
3116 tipc_printf(buf, ": NXO(%u):", mod(l_ptr->next_out_no));
3117 tipc_printf(buf, "NXI(%u):", mod(l_ptr->next_in_no));
3118 tipc_printf(buf, "SQUE");
3119 if (l_ptr->first_out) {
3120 tipc_printf(buf, "[%u..", buf_seqno(l_ptr->first_out));
3121 if (l_ptr->next_out)
3122 tipc_printf(buf, "%u..", buf_seqno(l_ptr->next_out));
3123 tipc_printf(buf, "%u]", buf_seqno(l_ptr->last_out));
3124 if ((mod(buf_seqno(l_ptr->last_out) -
3125 buf_seqno(l_ptr->first_out))
3126 != (l_ptr->out_queue_size - 1)) ||
3127 (l_ptr->last_out->next != NULL)) {
3128 tipc_printf(buf, "\nSend queue inconsistency\n");
3129 tipc_printf(buf, "first_out= %p ", l_ptr->first_out);
3130 tipc_printf(buf, "next_out= %p ", l_ptr->next_out);
3131 tipc_printf(buf, "last_out= %p ", l_ptr->last_out);
3132 }
3133 } else
3134 tipc_printf(buf, "[]");
3135 tipc_printf(buf, "SQSIZ(%u)", l_ptr->out_queue_size);
3136 if (l_ptr->oldest_deferred_in) {
3137 u32 o = buf_seqno(l_ptr->oldest_deferred_in);
3138 u32 n = buf_seqno(l_ptr->newest_deferred_in);
3139 tipc_printf(buf, ":RQUE[%u..%u]", o, n);
3140 if (l_ptr->deferred_inqueue_sz != mod((n + 1) - o)) {
3141 tipc_printf(buf, ":RQSIZ(%u)",
3142 l_ptr->deferred_inqueue_sz);
3143 }
3144 }
3145 print_state:
3146 #endif
3147
3148 if (link_working_unknown(l_ptr))
3149 tipc_printf(buf, ":WU");
3150 else if (link_reset_reset(l_ptr))
3151 tipc_printf(buf, ":RR");
3152 else if (link_reset_unknown(l_ptr))
3153 tipc_printf(buf, ":RU");
3154 else if (link_working_working(l_ptr))
3155 tipc_printf(buf, ":WW");
3156 tipc_printf(buf, "\n");
3157
3158 tipc_printbuf_validate(buf);
3159 info("%s", print_area);
3160 }
3161
Linux 2.6 libata-dev (mirror)