1 /*
2 * net/tipc/link.c: TIPC link code
3 *
4 * Copyright (c) 1996-2007, 2012-2016, Ericsson AB
5 * Copyright (c) 2004-2007, 2010-2013, Wind River Systems
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the names of the copyright holders nor the names of its
17 * contributors may be used to endorse or promote products derived from
18 * this software without specific prior written permission.
19 *
20 * Alternatively, this software may be distributed under the terms of the
21 * GNU General Public License ("GPL") version 2 as published by the Free
22 * Software Foundation.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34 * POSSIBILITY OF SUCH DAMAGE.
35 */
36
37 #include "core.h"
38 #include "subscr.h"
39 #include "link.h"
40 #include "bcast.h"
41 #include "socket.h"
42 #include "name_distr.h"
43 #include "discover.h"
44 #include "netlink.h"
45 #include "monitor.h"
46 #include "trace.h"
47 #include "crypto.h"
48
49 #include <linux/pkt_sched.h>
50
51 struct tipc_stats {
52 u32 sent_pkts;
53 u32 recv_pkts;
54 u32 sent_states;
55 u32 recv_states;
56 u32 sent_probes;
57 u32 recv_probes;
58 u32 sent_nacks;
59 u32 recv_nacks;
60 u32 sent_acks;
61 u32 sent_bundled;
62 u32 sent_bundles;
63 u32 recv_bundled;
64 u32 recv_bundles;
65 u32 retransmitted;
66 u32 sent_fragmented;
67 u32 sent_fragments;
68 u32 recv_fragmented;
69 u32 recv_fragments;
70 u32 link_congs; /* # port sends blocked by congestion */
71 u32 deferred_recv;
72 u32 duplicates;
73 u32 max_queue_sz; /* send queue size high water mark */
74 u32 accu_queue_sz; /* used for send queue size profiling */
75 u32 queue_sz_counts; /* used for send queue size profiling */
76 u32 msg_length_counts; /* used for message length profiling */
77 u32 msg_lengths_total; /* used for message length profiling */
78 u32 msg_length_profile[7]; /* used for msg. length profiling */
79 };
80
81 /**
82 * struct tipc_link - TIPC link data structure
83 * @addr: network address of link's peer node
84 * @name: link name character string
85 * @net: pointer to namespace struct
86 * @peer_session: link session # being used by peer end of link
87 * @peer_bearer_id: bearer id used by link's peer endpoint
88 * @bearer_id: local bearer id used by link
89 * @tolerance: minimum link continuity loss needed to reset link [in ms]
90 * @abort_limit: # of unacknowledged continuity probes needed to reset link
91 * @state: current state of link FSM
92 * @peer_caps: bitmap describing capabilities of peer node
93 * @silent_intv_cnt: # of timer intervals without any reception from peer
94 * @priority: current link priority
95 * @net_plane: current link network plane ('A' through 'H')
96 * @mon_state: cookie with information needed by link monitor
97 * @mtu: current maximum packet size for this link
98 * @advertised_mtu: advertised own mtu when link is being established
99 * @backlogq: queue for messages waiting to be sent
100 * @ackers: # of peers that needs to ack each packet before it can be released
101 * @acked: # last packet acked by a certain peer. Used for broadcast.
102 * @rcv_nxt: next sequence number to expect for inbound messages
103 * @inputq: buffer queue for messages to be delivered upwards
104 * @namedq: buffer queue for name table messages to be delivered upwards
105 * @wakeupq: linked list of wakeup msgs waiting for link congestion to abate
106 * @reasm_buf: head of partially reassembled inbound message fragments
107 * @stats: collects statistics regarding link activity
108 * @session: session to be used by link
109 * @snd_nxt_state: next send seq number
110 * @rcv_nxt_state: next rcv seq number
111 * @in_session: have received ACTIVATE_MSG from peer
112 * @active: link is active
113 * @if_name: associated interface name
114 * @rst_cnt: link reset counter
115 * @drop_point: seq number for failover handling (FIXME)
116 * @failover_reasm_skb: saved failover msg ptr (FIXME)
117 * @failover_deferdq: deferred message queue for failover processing (FIXME)
118 * @transmq: the link's transmit queue
119 * @backlog: link's backlog by priority (importance)
120 * @snd_nxt: next sequence number to be used
121 * @rcv_unacked: # messages read by user, but not yet acked back to peer
122 * @deferdq: deferred receive queue
123 * @window: sliding window size for congestion handling
124 * @min_win: minimal send window to be used by link
125 * @ssthresh: slow start threshold for congestion handling
126 * @max_win: maximal send window to be used by link
127 * @cong_acks: congestion acks for congestion avoidance (FIXME)
128 * @checkpoint: seq number for congestion window size handling
129 * @reasm_tnlmsg: fragmentation/reassembly area for tunnel protocol message
130 * @last_gap: last gap ack blocks for bcast (FIXME)
131 * @last_ga: ptr to gap ack blocks
132 * @bc_rcvlink: the peer specific link used for broadcast reception
133 * @bc_sndlink: the namespace global link used for broadcast sending
134 * @nack_state: bcast nack state
135 * @bc_peer_is_up: peer has acked the bcast init msg
136 */
137 struct tipc_link {
138 u32 addr;
139 char name[TIPC_MAX_LINK_NAME];
140 struct net *net;
141
142 /* Management and link supervision data */
143 u16 peer_session;
144 u16 session;
145 u16 snd_nxt_state;
146 u16 rcv_nxt_state;
147 u32 peer_bearer_id;
148 u32 bearer_id;
149 u32 tolerance;
150 u32 abort_limit;
151 u32 state;
152 u16 peer_caps;
153 bool in_session;
154 bool active;
155 u32 silent_intv_cnt;
156 char if_name[TIPC_MAX_IF_NAME];
157 u32 priority;
158 char net_plane;
159 struct tipc_mon_state mon_state;
160 u16 rst_cnt;
161
162 /* Failover/synch */
163 u16 drop_point;
164 struct sk_buff *failover_reasm_skb;
165 struct sk_buff_head failover_deferdq;
166
167 /* Max packet negotiation */
168 u16 mtu;
169 u16 advertised_mtu;
170
171 /* Sending */
172 struct sk_buff_head transmq;
173 struct sk_buff_head backlogq;
174 struct {
175 u16 len;
176 u16 limit;
177 struct sk_buff *target_bskb;
178 } backlog[5];
179 u16 snd_nxt;
180
181 /* Reception */
182 u16 rcv_nxt;
183 u32 rcv_unacked;
184 struct sk_buff_head deferdq;
185 struct sk_buff_head *inputq;
186 struct sk_buff_head *namedq;
187
188 /* Congestion handling */
189 struct sk_buff_head wakeupq;
190 u16 window;
191 u16 min_win;
192 u16 ssthresh;
193 u16 max_win;
194 u16 cong_acks;
195 u16 checkpoint;
196
197 /* Fragmentation/reassembly */
198 struct sk_buff *reasm_buf;
199 struct sk_buff *reasm_tnlmsg;
200
201 /* Broadcast */
202 u16 ackers;
203 u16 acked;
204 u16 last_gap;
205 struct tipc_gap_ack_blks *last_ga;
206 struct tipc_link *bc_rcvlink;
207 struct tipc_link *bc_sndlink;
208 u8 nack_state;
209 bool bc_peer_is_up;
210
211 /* Statistics */
212 struct tipc_stats stats;
213 };
214
215 /*
216 * Error message prefixes
217 */
218 static const char *link_co_err = "Link tunneling error, ";
219 static const char *link_rst_msg = "Resetting link ";
220
221 /* Send states for broadcast NACKs
222 */
223 enum {
224 BC_NACK_SND_CONDITIONAL,
225 BC_NACK_SND_UNCONDITIONAL,
226 BC_NACK_SND_SUPPRESS,
227 };
228
229 #define TIPC_BC_RETR_LIM (jiffies + msecs_to_jiffies(10))
230 #define TIPC_UC_RETR_TIME (jiffies + msecs_to_jiffies(1))
231
232 /* Link FSM states:
233 */
234 enum {
235 LINK_ESTABLISHED = 0xe,
236 LINK_ESTABLISHING = 0xe << 4,
237 LINK_RESET = 0x1 << 8,
238 LINK_RESETTING = 0x2 << 12,
239 LINK_PEER_RESET = 0xd << 16,
240 LINK_FAILINGOVER = 0xf << 20,
241 LINK_SYNCHING = 0xc << 24
242 };
243
244 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
245 struct sk_buff_head *xmitq);
246 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
247 bool probe_reply, u16 rcvgap,
248 int tolerance, int priority,
249 struct sk_buff_head *xmitq);
250 static void link_print(struct tipc_link *l, const char *str);
251 static int tipc_link_build_nack_msg(struct tipc_link *l,
252 struct sk_buff_head *xmitq);
253 static void tipc_link_build_bc_init_msg(struct tipc_link *l,
254 struct sk_buff_head *xmitq);
255 static u8 __tipc_build_gap_ack_blks(struct tipc_gap_ack_blks *ga,
256 struct tipc_link *l, u8 start_index);
257 static u16 tipc_build_gap_ack_blks(struct tipc_link *l, struct tipc_msg *hdr);
258 static int tipc_link_advance_transmq(struct tipc_link *l, struct tipc_link *r,
259 u16 acked, u16 gap,
260 struct tipc_gap_ack_blks *ga,
261 struct sk_buff_head *xmitq,
262 bool *retransmitted, int *rc);
263 static void tipc_link_update_cwin(struct tipc_link *l, int released,
264 bool retransmitted);
265 /*
266 * Simple non-static link routines (i.e. referenced outside this file)
267 */
tipc_link_is_up(struct tipc_link * l)268 bool tipc_link_is_up(struct tipc_link *l)
269 {
270 return l->state & (LINK_ESTABLISHED | LINK_SYNCHING);
271 }
272
tipc_link_peer_is_down(struct tipc_link * l)273 bool tipc_link_peer_is_down(struct tipc_link *l)
274 {
275 return l->state == LINK_PEER_RESET;
276 }
277
tipc_link_is_reset(struct tipc_link * l)278 bool tipc_link_is_reset(struct tipc_link *l)
279 {
280 return l->state & (LINK_RESET | LINK_FAILINGOVER | LINK_ESTABLISHING);
281 }
282
tipc_link_is_establishing(struct tipc_link * l)283 bool tipc_link_is_establishing(struct tipc_link *l)
284 {
285 return l->state == LINK_ESTABLISHING;
286 }
287
tipc_link_is_synching(struct tipc_link * l)288 bool tipc_link_is_synching(struct tipc_link *l)
289 {
290 return l->state == LINK_SYNCHING;
291 }
292
tipc_link_is_failingover(struct tipc_link * l)293 bool tipc_link_is_failingover(struct tipc_link *l)
294 {
295 return l->state == LINK_FAILINGOVER;
296 }
297
tipc_link_is_blocked(struct tipc_link * l)298 bool tipc_link_is_blocked(struct tipc_link *l)
299 {
300 return l->state & (LINK_RESETTING | LINK_PEER_RESET | LINK_FAILINGOVER);
301 }
302
link_is_bc_sndlink(struct tipc_link * l)303 static bool link_is_bc_sndlink(struct tipc_link *l)
304 {
305 return !l->bc_sndlink;
306 }
307
link_is_bc_rcvlink(struct tipc_link * l)308 static bool link_is_bc_rcvlink(struct tipc_link *l)
309 {
310 return ((l->bc_rcvlink == l) && !link_is_bc_sndlink(l));
311 }
312
tipc_link_set_active(struct tipc_link * l,bool active)313 void tipc_link_set_active(struct tipc_link *l, bool active)
314 {
315 l->active = active;
316 }
317
tipc_link_id(struct tipc_link * l)318 u32 tipc_link_id(struct tipc_link *l)
319 {
320 return l->peer_bearer_id << 16 | l->bearer_id;
321 }
322
tipc_link_min_win(struct tipc_link * l)323 int tipc_link_min_win(struct tipc_link *l)
324 {
325 return l->min_win;
326 }
327
tipc_link_max_win(struct tipc_link * l)328 int tipc_link_max_win(struct tipc_link *l)
329 {
330 return l->max_win;
331 }
332
tipc_link_prio(struct tipc_link * l)333 int tipc_link_prio(struct tipc_link *l)
334 {
335 return l->priority;
336 }
337
tipc_link_tolerance(struct tipc_link * l)338 unsigned long tipc_link_tolerance(struct tipc_link *l)
339 {
340 return l->tolerance;
341 }
342
tipc_link_inputq(struct tipc_link * l)343 struct sk_buff_head *tipc_link_inputq(struct tipc_link *l)
344 {
345 return l->inputq;
346 }
347
tipc_link_plane(struct tipc_link * l)348 char tipc_link_plane(struct tipc_link *l)
349 {
350 return l->net_plane;
351 }
352
tipc_link_net(struct tipc_link * l)353 struct net *tipc_link_net(struct tipc_link *l)
354 {
355 return l->net;
356 }
357
tipc_link_update_caps(struct tipc_link * l,u16 capabilities)358 void tipc_link_update_caps(struct tipc_link *l, u16 capabilities)
359 {
360 l->peer_caps = capabilities;
361 }
362
tipc_link_add_bc_peer(struct tipc_link * snd_l,struct tipc_link * uc_l,struct sk_buff_head * xmitq)363 void tipc_link_add_bc_peer(struct tipc_link *snd_l,
364 struct tipc_link *uc_l,
365 struct sk_buff_head *xmitq)
366 {
367 struct tipc_link *rcv_l = uc_l->bc_rcvlink;
368
369 snd_l->ackers++;
370 rcv_l->acked = snd_l->snd_nxt - 1;
371 snd_l->state = LINK_ESTABLISHED;
372 tipc_link_build_bc_init_msg(uc_l, xmitq);
373 }
374
tipc_link_remove_bc_peer(struct tipc_link * snd_l,struct tipc_link * rcv_l,struct sk_buff_head * xmitq)375 void tipc_link_remove_bc_peer(struct tipc_link *snd_l,
376 struct tipc_link *rcv_l,
377 struct sk_buff_head *xmitq)
378 {
379 u16 ack = snd_l->snd_nxt - 1;
380
381 snd_l->ackers--;
382 rcv_l->bc_peer_is_up = true;
383 rcv_l->state = LINK_ESTABLISHED;
384 tipc_link_bc_ack_rcv(rcv_l, ack, 0, NULL, xmitq, NULL);
385 trace_tipc_link_reset(rcv_l, TIPC_DUMP_ALL, "bclink removed!");
386 tipc_link_reset(rcv_l);
387 rcv_l->state = LINK_RESET;
388 if (!snd_l->ackers) {
389 trace_tipc_link_reset(snd_l, TIPC_DUMP_ALL, "zero ackers!");
390 tipc_link_reset(snd_l);
391 snd_l->state = LINK_RESET;
392 __skb_queue_purge(xmitq);
393 }
394 }
395
tipc_link_bc_peers(struct tipc_link * l)396 int tipc_link_bc_peers(struct tipc_link *l)
397 {
398 return l->ackers;
399 }
400
link_bc_rcv_gap(struct tipc_link * l)401 static u16 link_bc_rcv_gap(struct tipc_link *l)
402 {
403 struct sk_buff *skb = skb_peek(&l->deferdq);
404 u16 gap = 0;
405
406 if (more(l->snd_nxt, l->rcv_nxt))
407 gap = l->snd_nxt - l->rcv_nxt;
408 if (skb)
409 gap = buf_seqno(skb) - l->rcv_nxt;
410 return gap;
411 }
412
tipc_link_set_mtu(struct tipc_link * l,int mtu)413 void tipc_link_set_mtu(struct tipc_link *l, int mtu)
414 {
415 l->mtu = mtu;
416 }
417
tipc_link_mtu(struct tipc_link * l)418 int tipc_link_mtu(struct tipc_link *l)
419 {
420 return l->mtu;
421 }
422
tipc_link_mss(struct tipc_link * l)423 int tipc_link_mss(struct tipc_link *l)
424 {
425 #ifdef CONFIG_TIPC_CRYPTO
426 return l->mtu - INT_H_SIZE - EMSG_OVERHEAD;
427 #else
428 return l->mtu - INT_H_SIZE;
429 #endif
430 }
431
tipc_link_rcv_nxt(struct tipc_link * l)432 u16 tipc_link_rcv_nxt(struct tipc_link *l)
433 {
434 return l->rcv_nxt;
435 }
436
tipc_link_acked(struct tipc_link * l)437 u16 tipc_link_acked(struct tipc_link *l)
438 {
439 return l->acked;
440 }
441
tipc_link_name(struct tipc_link * l)442 char *tipc_link_name(struct tipc_link *l)
443 {
444 return l->name;
445 }
446
tipc_link_state(struct tipc_link * l)447 u32 tipc_link_state(struct tipc_link *l)
448 {
449 return l->state;
450 }
451
452 /**
453 * tipc_link_create - create a new link
454 * @net: pointer to associated network namespace
455 * @if_name: associated interface name
456 * @bearer_id: id (index) of associated bearer
457 * @tolerance: link tolerance to be used by link
458 * @net_plane: network plane (A,B,c..) this link belongs to
459 * @mtu: mtu to be advertised by link
460 * @priority: priority to be used by link
461 * @min_win: minimal send window to be used by link
462 * @max_win: maximal send window to be used by link
463 * @session: session to be used by link
464 * @peer: node id of peer node
465 * @peer_caps: bitmap describing peer node capabilities
466 * @bc_sndlink: the namespace global link used for broadcast sending
467 * @bc_rcvlink: the peer specific link used for broadcast reception
468 * @inputq: queue to put messages ready for delivery
469 * @namedq: queue to put binding table update messages ready for delivery
470 * @link: return value, pointer to put the created link
471 * @self: local unicast link id
472 * @peer_id: 128-bit ID of peer
473 *
474 * Return: true if link was created, otherwise false
475 */
tipc_link_create(struct net * net,char * if_name,int bearer_id,int tolerance,char net_plane,u32 mtu,int priority,u32 min_win,u32 max_win,u32 session,u32 self,u32 peer,u8 * peer_id,u16 peer_caps,struct tipc_link * bc_sndlink,struct tipc_link * bc_rcvlink,struct sk_buff_head * inputq,struct sk_buff_head * namedq,struct tipc_link ** link)476 bool tipc_link_create(struct net *net, char *if_name, int bearer_id,
477 int tolerance, char net_plane, u32 mtu, int priority,
478 u32 min_win, u32 max_win, u32 session, u32 self,
479 u32 peer, u8 *peer_id, u16 peer_caps,
480 struct tipc_link *bc_sndlink,
481 struct tipc_link *bc_rcvlink,
482 struct sk_buff_head *inputq,
483 struct sk_buff_head *namedq,
484 struct tipc_link **link)
485 {
486 char peer_str[NODE_ID_STR_LEN] = {0,};
487 char self_str[NODE_ID_STR_LEN] = {0,};
488 struct tipc_link *l;
489
490 l = kzalloc(sizeof(*l), GFP_ATOMIC);
491 if (!l)
492 return false;
493 *link = l;
494 l->session = session;
495
496 /* Set link name for unicast links only */
497 if (peer_id) {
498 tipc_nodeid2string(self_str, tipc_own_id(net));
499 if (strlen(self_str) > 16)
500 sprintf(self_str, "%x", self);
501 tipc_nodeid2string(peer_str, peer_id);
502 if (strlen(peer_str) > 16)
503 sprintf(peer_str, "%x", peer);
504 }
505 /* Peer i/f name will be completed by reset/activate message */
506 snprintf(l->name, sizeof(l->name), "%s:%s-%s:unknown",
507 self_str, if_name, peer_str);
508
509 strcpy(l->if_name, if_name);
510 l->addr = peer;
511 l->peer_caps = peer_caps;
512 l->net = net;
513 l->in_session = false;
514 l->bearer_id = bearer_id;
515 l->tolerance = tolerance;
516 if (bc_rcvlink)
517 bc_rcvlink->tolerance = tolerance;
518 l->net_plane = net_plane;
519 l->advertised_mtu = mtu;
520 l->mtu = mtu;
521 l->priority = priority;
522 tipc_link_set_queue_limits(l, min_win, max_win);
523 l->ackers = 1;
524 l->bc_sndlink = bc_sndlink;
525 l->bc_rcvlink = bc_rcvlink;
526 l->inputq = inputq;
527 l->namedq = namedq;
528 l->state = LINK_RESETTING;
529 __skb_queue_head_init(&l->transmq);
530 __skb_queue_head_init(&l->backlogq);
531 __skb_queue_head_init(&l->deferdq);
532 __skb_queue_head_init(&l->failover_deferdq);
533 skb_queue_head_init(&l->wakeupq);
534 skb_queue_head_init(l->inputq);
535 return true;
536 }
537
538 /**
539 * tipc_link_bc_create - create new link to be used for broadcast
540 * @net: pointer to associated network namespace
541 * @mtu: mtu to be used initially if no peers
542 * @min_win: minimal send window to be used by link
543 * @max_win: maximal send window to be used by link
544 * @inputq: queue to put messages ready for delivery
545 * @namedq: queue to put binding table update messages ready for delivery
546 * @link: return value, pointer to put the created link
547 * @ownnode: identity of own node
548 * @peer: node id of peer node
549 * @peer_id: 128-bit ID of peer
550 * @peer_caps: bitmap describing peer node capabilities
551 * @bc_sndlink: the namespace global link used for broadcast sending
552 *
553 * Return: true if link was created, otherwise false
554 */
tipc_link_bc_create(struct net * net,u32 ownnode,u32 peer,u8 * peer_id,int mtu,u32 min_win,u32 max_win,u16 peer_caps,struct sk_buff_head * inputq,struct sk_buff_head * namedq,struct tipc_link * bc_sndlink,struct tipc_link ** link)555 bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer, u8 *peer_id,
556 int mtu, u32 min_win, u32 max_win, u16 peer_caps,
557 struct sk_buff_head *inputq,
558 struct sk_buff_head *namedq,
559 struct tipc_link *bc_sndlink,
560 struct tipc_link **link)
561 {
562 struct tipc_link *l;
563
564 if (!tipc_link_create(net, "", MAX_BEARERS, 0, 'Z', mtu, 0, min_win,
565 max_win, 0, ownnode, peer, NULL, peer_caps,
566 bc_sndlink, NULL, inputq, namedq, link))
567 return false;
568
569 l = *link;
570 if (peer_id) {
571 char peer_str[NODE_ID_STR_LEN] = {0,};
572
573 tipc_nodeid2string(peer_str, peer_id);
574 if (strlen(peer_str) > 16)
575 sprintf(peer_str, "%x", peer);
576 /* Broadcast receiver link name: "broadcast-link:<peer>" */
577 snprintf(l->name, sizeof(l->name), "%s:%s", tipc_bclink_name,
578 peer_str);
579 } else {
580 strcpy(l->name, tipc_bclink_name);
581 }
582 trace_tipc_link_reset(l, TIPC_DUMP_ALL, "bclink created!");
583 tipc_link_reset(l);
584 l->state = LINK_RESET;
585 l->ackers = 0;
586 l->bc_rcvlink = l;
587
588 /* Broadcast send link is always up */
589 if (link_is_bc_sndlink(l))
590 l->state = LINK_ESTABLISHED;
591
592 /* Disable replicast if even a single peer doesn't support it */
593 if (link_is_bc_rcvlink(l) && !(peer_caps & TIPC_BCAST_RCAST))
594 tipc_bcast_toggle_rcast(net, false);
595
596 return true;
597 }
598
599 /**
600 * tipc_link_fsm_evt - link finite state machine
601 * @l: pointer to link
602 * @evt: state machine event to be processed
603 */
tipc_link_fsm_evt(struct tipc_link * l,int evt)604 int tipc_link_fsm_evt(struct tipc_link *l, int evt)
605 {
606 int rc = 0;
607 int old_state = l->state;
608
609 switch (l->state) {
610 case LINK_RESETTING:
611 switch (evt) {
612 case LINK_PEER_RESET_EVT:
613 l->state = LINK_PEER_RESET;
614 break;
615 case LINK_RESET_EVT:
616 l->state = LINK_RESET;
617 break;
618 case LINK_FAILURE_EVT:
619 case LINK_FAILOVER_BEGIN_EVT:
620 case LINK_ESTABLISH_EVT:
621 case LINK_FAILOVER_END_EVT:
622 case LINK_SYNCH_BEGIN_EVT:
623 case LINK_SYNCH_END_EVT:
624 default:
625 goto illegal_evt;
626 }
627 break;
628 case LINK_RESET:
629 switch (evt) {
630 case LINK_PEER_RESET_EVT:
631 l->state = LINK_ESTABLISHING;
632 break;
633 case LINK_FAILOVER_BEGIN_EVT:
634 l->state = LINK_FAILINGOVER;
635 break;
636 case LINK_FAILURE_EVT:
637 case LINK_RESET_EVT:
638 case LINK_ESTABLISH_EVT:
639 case LINK_FAILOVER_END_EVT:
640 break;
641 case LINK_SYNCH_BEGIN_EVT:
642 case LINK_SYNCH_END_EVT:
643 default:
644 goto illegal_evt;
645 }
646 break;
647 case LINK_PEER_RESET:
648 switch (evt) {
649 case LINK_RESET_EVT:
650 l->state = LINK_ESTABLISHING;
651 break;
652 case LINK_PEER_RESET_EVT:
653 case LINK_ESTABLISH_EVT:
654 case LINK_FAILURE_EVT:
655 break;
656 case LINK_SYNCH_BEGIN_EVT:
657 case LINK_SYNCH_END_EVT:
658 case LINK_FAILOVER_BEGIN_EVT:
659 case LINK_FAILOVER_END_EVT:
660 default:
661 goto illegal_evt;
662 }
663 break;
664 case LINK_FAILINGOVER:
665 switch (evt) {
666 case LINK_FAILOVER_END_EVT:
667 l->state = LINK_RESET;
668 break;
669 case LINK_PEER_RESET_EVT:
670 case LINK_RESET_EVT:
671 case LINK_ESTABLISH_EVT:
672 case LINK_FAILURE_EVT:
673 break;
674 case LINK_FAILOVER_BEGIN_EVT:
675 case LINK_SYNCH_BEGIN_EVT:
676 case LINK_SYNCH_END_EVT:
677 default:
678 goto illegal_evt;
679 }
680 break;
681 case LINK_ESTABLISHING:
682 switch (evt) {
683 case LINK_ESTABLISH_EVT:
684 l->state = LINK_ESTABLISHED;
685 break;
686 case LINK_FAILOVER_BEGIN_EVT:
687 l->state = LINK_FAILINGOVER;
688 break;
689 case LINK_RESET_EVT:
690 l->state = LINK_RESET;
691 break;
692 case LINK_FAILURE_EVT:
693 case LINK_PEER_RESET_EVT:
694 case LINK_SYNCH_BEGIN_EVT:
695 case LINK_FAILOVER_END_EVT:
696 break;
697 case LINK_SYNCH_END_EVT:
698 default:
699 goto illegal_evt;
700 }
701 break;
702 case LINK_ESTABLISHED:
703 switch (evt) {
704 case LINK_PEER_RESET_EVT:
705 l->state = LINK_PEER_RESET;
706 rc |= TIPC_LINK_DOWN_EVT;
707 break;
708 case LINK_FAILURE_EVT:
709 l->state = LINK_RESETTING;
710 rc |= TIPC_LINK_DOWN_EVT;
711 break;
712 case LINK_RESET_EVT:
713 l->state = LINK_RESET;
714 break;
715 case LINK_ESTABLISH_EVT:
716 case LINK_SYNCH_END_EVT:
717 break;
718 case LINK_SYNCH_BEGIN_EVT:
719 l->state = LINK_SYNCHING;
720 break;
721 case LINK_FAILOVER_BEGIN_EVT:
722 case LINK_FAILOVER_END_EVT:
723 default:
724 goto illegal_evt;
725 }
726 break;
727 case LINK_SYNCHING:
728 switch (evt) {
729 case LINK_PEER_RESET_EVT:
730 l->state = LINK_PEER_RESET;
731 rc |= TIPC_LINK_DOWN_EVT;
732 break;
733 case LINK_FAILURE_EVT:
734 l->state = LINK_RESETTING;
735 rc |= TIPC_LINK_DOWN_EVT;
736 break;
737 case LINK_RESET_EVT:
738 l->state = LINK_RESET;
739 break;
740 case LINK_ESTABLISH_EVT:
741 case LINK_SYNCH_BEGIN_EVT:
742 break;
743 case LINK_SYNCH_END_EVT:
744 l->state = LINK_ESTABLISHED;
745 break;
746 case LINK_FAILOVER_BEGIN_EVT:
747 case LINK_FAILOVER_END_EVT:
748 default:
749 goto illegal_evt;
750 }
751 break;
752 default:
753 pr_err("Unknown FSM state %x in %s\n", l->state, l->name);
754 }
755 trace_tipc_link_fsm(l->name, old_state, l->state, evt);
756 return rc;
757 illegal_evt:
758 pr_err("Illegal FSM event %x in state %x on link %s\n",
759 evt, l->state, l->name);
760 trace_tipc_link_fsm(l->name, old_state, l->state, evt);
761 return rc;
762 }
763
764 /* link_profile_stats - update statistical profiling of traffic
765 */
link_profile_stats(struct tipc_link * l)766 static void link_profile_stats(struct tipc_link *l)
767 {
768 struct sk_buff *skb;
769 struct tipc_msg *msg;
770 int length;
771
772 /* Update counters used in statistical profiling of send traffic */
773 l->stats.accu_queue_sz += skb_queue_len(&l->transmq);
774 l->stats.queue_sz_counts++;
775
776 skb = skb_peek(&l->transmq);
777 if (!skb)
778 return;
779 msg = buf_msg(skb);
780 length = msg_size(msg);
781
782 if (msg_user(msg) == MSG_FRAGMENTER) {
783 if (msg_type(msg) != FIRST_FRAGMENT)
784 return;
785 length = msg_size(msg_inner_hdr(msg));
786 }
787 l->stats.msg_lengths_total += length;
788 l->stats.msg_length_counts++;
789 if (length <= 64)
790 l->stats.msg_length_profile[0]++;
791 else if (length <= 256)
792 l->stats.msg_length_profile[1]++;
793 else if (length <= 1024)
794 l->stats.msg_length_profile[2]++;
795 else if (length <= 4096)
796 l->stats.msg_length_profile[3]++;
797 else if (length <= 16384)
798 l->stats.msg_length_profile[4]++;
799 else if (length <= 32768)
800 l->stats.msg_length_profile[5]++;
801 else
802 l->stats.msg_length_profile[6]++;
803 }
804
805 /**
806 * tipc_link_too_silent - check if link is "too silent"
807 * @l: tipc link to be checked
808 *
809 * Return: true if the link 'silent_intv_cnt' is about to reach the
810 * 'abort_limit' value, otherwise false
811 */
tipc_link_too_silent(struct tipc_link * l)812 bool tipc_link_too_silent(struct tipc_link *l)
813 {
814 return (l->silent_intv_cnt + 2 > l->abort_limit);
815 }
816
817 /* tipc_link_timeout - perform periodic task as instructed from node timeout
818 */
tipc_link_timeout(struct tipc_link * l,struct sk_buff_head * xmitq)819 int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
820 {
821 int mtyp = 0;
822 int rc = 0;
823 bool state = false;
824 bool probe = false;
825 bool setup = false;
826 u16 bc_snt = l->bc_sndlink->snd_nxt - 1;
827 u16 bc_acked = l->bc_rcvlink->acked;
828 struct tipc_mon_state *mstate = &l->mon_state;
829
830 trace_tipc_link_timeout(l, TIPC_DUMP_NONE, " ");
831 trace_tipc_link_too_silent(l, TIPC_DUMP_ALL, " ");
832 switch (l->state) {
833 case LINK_ESTABLISHED:
834 case LINK_SYNCHING:
835 mtyp = STATE_MSG;
836 link_profile_stats(l);
837 tipc_mon_get_state(l->net, l->addr, mstate, l->bearer_id);
838 if (mstate->reset || (l->silent_intv_cnt > l->abort_limit))
839 return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
840 state = bc_acked != bc_snt;
841 state |= l->bc_rcvlink->rcv_unacked;
842 state |= l->rcv_unacked;
843 state |= !skb_queue_empty(&l->transmq);
844 probe = mstate->probing;
845 probe |= l->silent_intv_cnt;
846 if (probe || mstate->monitoring)
847 l->silent_intv_cnt++;
848 probe |= !skb_queue_empty(&l->deferdq);
849 if (l->snd_nxt == l->checkpoint) {
850 tipc_link_update_cwin(l, 0, 0);
851 probe = true;
852 }
853 l->checkpoint = l->snd_nxt;
854 break;
855 case LINK_RESET:
856 setup = l->rst_cnt++ <= 4;
857 setup |= !(l->rst_cnt % 16);
858 mtyp = RESET_MSG;
859 break;
860 case LINK_ESTABLISHING:
861 setup = true;
862 mtyp = ACTIVATE_MSG;
863 break;
864 case LINK_PEER_RESET:
865 case LINK_RESETTING:
866 case LINK_FAILINGOVER:
867 break;
868 default:
869 break;
870 }
871
872 if (state || probe || setup)
873 tipc_link_build_proto_msg(l, mtyp, probe, 0, 0, 0, 0, xmitq);
874
875 return rc;
876 }
877
878 /**
879 * link_schedule_user - schedule a message sender for wakeup after congestion
880 * @l: congested link
881 * @hdr: header of message that is being sent
882 * Create pseudo msg to send back to user when congestion abates
883 */
link_schedule_user(struct tipc_link * l,struct tipc_msg * hdr)884 static int link_schedule_user(struct tipc_link *l, struct tipc_msg *hdr)
885 {
886 u32 dnode = tipc_own_addr(l->net);
887 u32 dport = msg_origport(hdr);
888 struct sk_buff *skb;
889
890 /* Create and schedule wakeup pseudo message */
891 skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
892 dnode, l->addr, dport, 0, 0);
893 if (!skb)
894 return -ENOBUFS;
895 msg_set_dest_droppable(buf_msg(skb), true);
896 TIPC_SKB_CB(skb)->chain_imp = msg_importance(hdr);
897 skb_queue_tail(&l->wakeupq, skb);
898 l->stats.link_congs++;
899 trace_tipc_link_conges(l, TIPC_DUMP_ALL, "wakeup scheduled!");
900 return -ELINKCONG;
901 }
902
903 /**
904 * link_prepare_wakeup - prepare users for wakeup after congestion
905 * @l: congested link
906 * Wake up a number of waiting users, as permitted by available space
907 * in the send queue
908 */
link_prepare_wakeup(struct tipc_link * l)909 static void link_prepare_wakeup(struct tipc_link *l)
910 {
911 struct sk_buff_head *wakeupq = &l->wakeupq;
912 struct sk_buff_head *inputq = l->inputq;
913 struct sk_buff *skb, *tmp;
914 struct sk_buff_head tmpq;
915 int avail[5] = {0,};
916 int imp = 0;
917
918 __skb_queue_head_init(&tmpq);
919
920 for (; imp <= TIPC_SYSTEM_IMPORTANCE; imp++)
921 avail[imp] = l->backlog[imp].limit - l->backlog[imp].len;
922
923 skb_queue_walk_safe(wakeupq, skb, tmp) {
924 imp = TIPC_SKB_CB(skb)->chain_imp;
925 if (avail[imp] <= 0)
926 continue;
927 avail[imp]--;
928 __skb_unlink(skb, wakeupq);
929 __skb_queue_tail(&tmpq, skb);
930 }
931
932 spin_lock_bh(&inputq->lock);
933 skb_queue_splice_tail(&tmpq, inputq);
934 spin_unlock_bh(&inputq->lock);
935
936 }
937
938 /**
939 * tipc_link_set_skb_retransmit_time - set the time at which retransmission of
940 * the given skb should be next attempted
941 * @skb: skb to set a future retransmission time for
942 * @l: link the skb will be transmitted on
943 */
tipc_link_set_skb_retransmit_time(struct sk_buff * skb,struct tipc_link * l)944 static void tipc_link_set_skb_retransmit_time(struct sk_buff *skb,
945 struct tipc_link *l)
946 {
947 if (link_is_bc_sndlink(l))
948 TIPC_SKB_CB(skb)->nxt_retr = TIPC_BC_RETR_LIM;
949 else
950 TIPC_SKB_CB(skb)->nxt_retr = TIPC_UC_RETR_TIME;
951 }
952
tipc_link_reset(struct tipc_link * l)953 void tipc_link_reset(struct tipc_link *l)
954 {
955 struct sk_buff_head list;
956 u32 imp;
957
958 __skb_queue_head_init(&list);
959
960 l->in_session = false;
961 /* Force re-synch of peer session number before establishing */
962 l->peer_session--;
963 l->session++;
964 l->mtu = l->advertised_mtu;
965
966 spin_lock_bh(&l->wakeupq.lock);
967 skb_queue_splice_init(&l->wakeupq, &list);
968 spin_unlock_bh(&l->wakeupq.lock);
969
970 spin_lock_bh(&l->inputq->lock);
971 skb_queue_splice_init(&list, l->inputq);
972 spin_unlock_bh(&l->inputq->lock);
973
974 __skb_queue_purge(&l->transmq);
975 __skb_queue_purge(&l->deferdq);
976 __skb_queue_purge(&l->backlogq);
977 __skb_queue_purge(&l->failover_deferdq);
978 for (imp = 0; imp <= TIPC_SYSTEM_IMPORTANCE; imp++) {
979 l->backlog[imp].len = 0;
980 l->backlog[imp].target_bskb = NULL;
981 }
982 kfree_skb(l->reasm_buf);
983 kfree_skb(l->reasm_tnlmsg);
984 kfree_skb(l->failover_reasm_skb);
985 l->reasm_buf = NULL;
986 l->reasm_tnlmsg = NULL;
987 l->failover_reasm_skb = NULL;
988 l->rcv_unacked = 0;
989 l->snd_nxt = 1;
990 l->rcv_nxt = 1;
991 l->snd_nxt_state = 1;
992 l->rcv_nxt_state = 1;
993 l->acked = 0;
994 l->last_gap = 0;
995 kfree(l->last_ga);
996 l->last_ga = NULL;
997 l->silent_intv_cnt = 0;
998 l->rst_cnt = 0;
999 l->bc_peer_is_up = false;
1000 memset(&l->mon_state, 0, sizeof(l->mon_state));
1001 tipc_link_reset_stats(l);
1002 }
1003
1004 /**
1005 * tipc_link_xmit(): enqueue buffer list according to queue situation
1006 * @l: link to use
1007 * @list: chain of buffers containing message
1008 * @xmitq: returned list of packets to be sent by caller
1009 *
1010 * Consumes the buffer chain.
1011 * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
1012 * Return: 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
1013 */
tipc_link_xmit(struct tipc_link * l,struct sk_buff_head * list,struct sk_buff_head * xmitq)1014 int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
1015 struct sk_buff_head *xmitq)
1016 {
1017 struct sk_buff_head *backlogq = &l->backlogq;
1018 struct sk_buff_head *transmq = &l->transmq;
1019 struct sk_buff *skb, *_skb;
1020 u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
1021 u16 ack = l->rcv_nxt - 1;
1022 u16 seqno = l->snd_nxt;
1023 int pkt_cnt = skb_queue_len(list);
1024 unsigned int mss = tipc_link_mss(l);
1025 unsigned int cwin = l->window;
1026 unsigned int mtu = l->mtu;
1027 struct tipc_msg *hdr;
1028 bool new_bundle;
1029 int rc = 0;
1030 int imp;
1031
1032 if (pkt_cnt <= 0)
1033 return 0;
1034
1035 hdr = buf_msg(skb_peek(list));
1036 if (unlikely(msg_size(hdr) > mtu)) {
1037 pr_warn("Too large msg, purging xmit list %d %d %d %d %d!\n",
1038 skb_queue_len(list), msg_user(hdr),
1039 msg_type(hdr), msg_size(hdr), mtu);
1040 __skb_queue_purge(list);
1041 return -EMSGSIZE;
1042 }
1043
1044 imp = msg_importance(hdr);
1045 /* Allow oversubscription of one data msg per source at congestion */
1046 if (unlikely(l->backlog[imp].len >= l->backlog[imp].limit)) {
1047 if (imp == TIPC_SYSTEM_IMPORTANCE) {
1048 pr_warn("%s<%s>, link overflow", link_rst_msg, l->name);
1049 __skb_queue_purge(list);
1050 return -ENOBUFS;
1051 }
1052 rc = link_schedule_user(l, hdr);
1053 }
1054
1055 if (pkt_cnt > 1) {
1056 l->stats.sent_fragmented++;
1057 l->stats.sent_fragments += pkt_cnt;
1058 }
1059
1060 /* Prepare each packet for sending, and add to relevant queue: */
1061 while ((skb = __skb_dequeue(list))) {
1062 if (likely(skb_queue_len(transmq) < cwin)) {
1063 hdr = buf_msg(skb);
1064 msg_set_seqno(hdr, seqno);
1065 msg_set_ack(hdr, ack);
1066 msg_set_bcast_ack(hdr, bc_ack);
1067 _skb = skb_clone(skb, GFP_ATOMIC);
1068 if (!_skb) {
1069 kfree_skb(skb);
1070 __skb_queue_purge(list);
1071 return -ENOBUFS;
1072 }
1073 __skb_queue_tail(transmq, skb);
1074 tipc_link_set_skb_retransmit_time(skb, l);
1075 __skb_queue_tail(xmitq, _skb);
1076 TIPC_SKB_CB(skb)->ackers = l->ackers;
1077 l->rcv_unacked = 0;
1078 l->stats.sent_pkts++;
1079 seqno++;
1080 continue;
1081 }
1082 if (tipc_msg_try_bundle(l->backlog[imp].target_bskb, &skb,
1083 mss, l->addr, &new_bundle)) {
1084 if (skb) {
1085 /* Keep a ref. to the skb for next try */
1086 l->backlog[imp].target_bskb = skb;
1087 l->backlog[imp].len++;
1088 __skb_queue_tail(backlogq, skb);
1089 } else {
1090 if (new_bundle) {
1091 l->stats.sent_bundles++;
1092 l->stats.sent_bundled++;
1093 }
1094 l->stats.sent_bundled++;
1095 }
1096 continue;
1097 }
1098 l->backlog[imp].target_bskb = NULL;
1099 l->backlog[imp].len += (1 + skb_queue_len(list));
1100 __skb_queue_tail(backlogq, skb);
1101 skb_queue_splice_tail_init(list, backlogq);
1102 }
1103 l->snd_nxt = seqno;
1104 return rc;
1105 }
1106
tipc_link_update_cwin(struct tipc_link * l,int released,bool retransmitted)1107 static void tipc_link_update_cwin(struct tipc_link *l, int released,
1108 bool retransmitted)
1109 {
1110 int bklog_len = skb_queue_len(&l->backlogq);
1111 struct sk_buff_head *txq = &l->transmq;
1112 int txq_len = skb_queue_len(txq);
1113 u16 cwin = l->window;
1114
1115 /* Enter fast recovery */
1116 if (unlikely(retransmitted)) {
1117 l->ssthresh = max_t(u16, l->window / 2, 300);
1118 l->window = min_t(u16, l->ssthresh, l->window);
1119 return;
1120 }
1121 /* Enter slow start */
1122 if (unlikely(!released)) {
1123 l->ssthresh = max_t(u16, l->window / 2, 300);
1124 l->window = l->min_win;
1125 return;
1126 }
1127 /* Don't increase window if no pressure on the transmit queue */
1128 if (txq_len + bklog_len < cwin)
1129 return;
1130
1131 /* Don't increase window if there are holes the transmit queue */
1132 if (txq_len && l->snd_nxt - buf_seqno(skb_peek(txq)) != txq_len)
1133 return;
1134
1135 l->cong_acks += released;
1136
1137 /* Slow start */
1138 if (cwin <= l->ssthresh) {
1139 l->window = min_t(u16, cwin + released, l->max_win);
1140 return;
1141 }
1142 /* Congestion avoidance */
1143 if (l->cong_acks < cwin)
1144 return;
1145 l->window = min_t(u16, ++cwin, l->max_win);
1146 l->cong_acks = 0;
1147 }
1148
tipc_link_advance_backlog(struct tipc_link * l,struct sk_buff_head * xmitq)1149 static void tipc_link_advance_backlog(struct tipc_link *l,
1150 struct sk_buff_head *xmitq)
1151 {
1152 u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
1153 struct sk_buff_head *txq = &l->transmq;
1154 struct sk_buff *skb, *_skb;
1155 u16 ack = l->rcv_nxt - 1;
1156 u16 seqno = l->snd_nxt;
1157 struct tipc_msg *hdr;
1158 u16 cwin = l->window;
1159 u32 imp;
1160
1161 while (skb_queue_len(txq) < cwin) {
1162 skb = skb_peek(&l->backlogq);
1163 if (!skb)
1164 break;
1165 _skb = skb_clone(skb, GFP_ATOMIC);
1166 if (!_skb)
1167 break;
1168 __skb_dequeue(&l->backlogq);
1169 hdr = buf_msg(skb);
1170 imp = msg_importance(hdr);
1171 l->backlog[imp].len--;
1172 if (unlikely(skb == l->backlog[imp].target_bskb))
1173 l->backlog[imp].target_bskb = NULL;
1174 __skb_queue_tail(&l->transmq, skb);
1175 tipc_link_set_skb_retransmit_time(skb, l);
1176
1177 __skb_queue_tail(xmitq, _skb);
1178 TIPC_SKB_CB(skb)->ackers = l->ackers;
1179 msg_set_seqno(hdr, seqno);
1180 msg_set_ack(hdr, ack);
1181 msg_set_bcast_ack(hdr, bc_ack);
1182 l->rcv_unacked = 0;
1183 l->stats.sent_pkts++;
1184 seqno++;
1185 }
1186 l->snd_nxt = seqno;
1187 }
1188
1189 /**
1190 * link_retransmit_failure() - Detect repeated retransmit failures
1191 * @l: tipc link sender
1192 * @r: tipc link receiver (= l in case of unicast)
1193 * @rc: returned code
1194 *
1195 * Return: true if the repeated retransmit failures happens, otherwise
1196 * false
1197 */
link_retransmit_failure(struct tipc_link * l,struct tipc_link * r,int * rc)1198 static bool link_retransmit_failure(struct tipc_link *l, struct tipc_link *r,
1199 int *rc)
1200 {
1201 struct sk_buff *skb = skb_peek(&l->transmq);
1202 struct tipc_msg *hdr;
1203
1204 if (!skb)
1205 return false;
1206
1207 if (!TIPC_SKB_CB(skb)->retr_cnt)
1208 return false;
1209
1210 if (!time_after(jiffies, TIPC_SKB_CB(skb)->retr_stamp +
1211 msecs_to_jiffies(r->tolerance * 10)))
1212 return false;
1213
1214 hdr = buf_msg(skb);
1215 if (link_is_bc_sndlink(l) && !less(r->acked, msg_seqno(hdr)))
1216 return false;
1217
1218 pr_warn("Retransmission failure on link <%s>\n", l->name);
1219 link_print(l, "State of link ");
1220 pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
1221 msg_user(hdr), msg_type(hdr), msg_size(hdr), msg_errcode(hdr));
1222 pr_info("sqno %u, prev: %x, dest: %x\n",
1223 msg_seqno(hdr), msg_prevnode(hdr), msg_destnode(hdr));
1224 pr_info("retr_stamp %d, retr_cnt %d\n",
1225 jiffies_to_msecs(TIPC_SKB_CB(skb)->retr_stamp),
1226 TIPC_SKB_CB(skb)->retr_cnt);
1227
1228 trace_tipc_list_dump(&l->transmq, true, "retrans failure!");
1229 trace_tipc_link_dump(l, TIPC_DUMP_NONE, "retrans failure!");
1230 trace_tipc_link_dump(r, TIPC_DUMP_NONE, "retrans failure!");
1231
1232 if (link_is_bc_sndlink(l)) {
1233 r->state = LINK_RESET;
1234 *rc |= TIPC_LINK_DOWN_EVT;
1235 } else {
1236 *rc |= tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1237 }
1238
1239 return true;
1240 }
1241
1242 /* tipc_data_input - deliver data and name distr msgs to upper layer
1243 *
1244 * Consumes buffer if message is of right type
1245 * Node lock must be held
1246 */
tipc_data_input(struct tipc_link * l,struct sk_buff * skb,struct sk_buff_head * inputq)1247 static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb,
1248 struct sk_buff_head *inputq)
1249 {
1250 struct sk_buff_head *mc_inputq = l->bc_rcvlink->inputq;
1251 struct tipc_msg *hdr = buf_msg(skb);
1252
1253 switch (msg_user(hdr)) {
1254 case TIPC_LOW_IMPORTANCE:
1255 case TIPC_MEDIUM_IMPORTANCE:
1256 case TIPC_HIGH_IMPORTANCE:
1257 case TIPC_CRITICAL_IMPORTANCE:
1258 if (unlikely(msg_in_group(hdr) || msg_mcast(hdr))) {
1259 skb_queue_tail(mc_inputq, skb);
1260 return true;
1261 }
1262 fallthrough;
1263 case CONN_MANAGER:
1264 skb_queue_tail(inputq, skb);
1265 return true;
1266 case GROUP_PROTOCOL:
1267 skb_queue_tail(mc_inputq, skb);
1268 return true;
1269 case NAME_DISTRIBUTOR:
1270 l->bc_rcvlink->state = LINK_ESTABLISHED;
1271 skb_queue_tail(l->namedq, skb);
1272 return true;
1273 case MSG_BUNDLER:
1274 case TUNNEL_PROTOCOL:
1275 case MSG_FRAGMENTER:
1276 case BCAST_PROTOCOL:
1277 return false;
1278 #ifdef CONFIG_TIPC_CRYPTO
1279 case MSG_CRYPTO:
1280 if (sysctl_tipc_key_exchange_enabled &&
1281 TIPC_SKB_CB(skb)->decrypted) {
1282 tipc_crypto_msg_rcv(l->net, skb);
1283 return true;
1284 }
1285 fallthrough;
1286 #endif
1287 default:
1288 pr_warn("Dropping received illegal msg type\n");
1289 kfree_skb(skb);
1290 return true;
1291 }
1292 }
1293
1294 /* tipc_link_input - process packet that has passed link protocol check
1295 *
1296 * Consumes buffer
1297 */
tipc_link_input(struct tipc_link * l,struct sk_buff * skb,struct sk_buff_head * inputq,struct sk_buff ** reasm_skb)1298 static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb,
1299 struct sk_buff_head *inputq,
1300 struct sk_buff **reasm_skb)
1301 {
1302 struct tipc_msg *hdr = buf_msg(skb);
1303 struct sk_buff *iskb;
1304 struct sk_buff_head tmpq;
1305 int usr = msg_user(hdr);
1306 int pos = 0;
1307
1308 if (usr == MSG_BUNDLER) {
1309 skb_queue_head_init(&tmpq);
1310 l->stats.recv_bundles++;
1311 l->stats.recv_bundled += msg_msgcnt(hdr);
1312 while (tipc_msg_extract(skb, &iskb, &pos))
1313 tipc_data_input(l, iskb, &tmpq);
1314 tipc_skb_queue_splice_tail(&tmpq, inputq);
1315 return 0;
1316 } else if (usr == MSG_FRAGMENTER) {
1317 l->stats.recv_fragments++;
1318 if (tipc_buf_append(reasm_skb, &skb)) {
1319 l->stats.recv_fragmented++;
1320 tipc_data_input(l, skb, inputq);
1321 } else if (!*reasm_skb && !link_is_bc_rcvlink(l)) {
1322 pr_warn_ratelimited("Unable to build fragment list\n");
1323 return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1324 }
1325 return 0;
1326 } else if (usr == BCAST_PROTOCOL) {
1327 tipc_bcast_lock(l->net);
1328 tipc_link_bc_init_rcv(l->bc_rcvlink, hdr);
1329 tipc_bcast_unlock(l->net);
1330 }
1331
1332 kfree_skb(skb);
1333 return 0;
1334 }
1335
1336 /* tipc_link_tnl_rcv() - receive TUNNEL_PROTOCOL message, drop or process the
1337 * inner message along with the ones in the old link's
1338 * deferdq
1339 * @l: tunnel link
1340 * @skb: TUNNEL_PROTOCOL message
1341 * @inputq: queue to put messages ready for delivery
1342 */
tipc_link_tnl_rcv(struct tipc_link * l,struct sk_buff * skb,struct sk_buff_head * inputq)1343 static int tipc_link_tnl_rcv(struct tipc_link *l, struct sk_buff *skb,
1344 struct sk_buff_head *inputq)
1345 {
1346 struct sk_buff **reasm_skb = &l->failover_reasm_skb;
1347 struct sk_buff **reasm_tnlmsg = &l->reasm_tnlmsg;
1348 struct sk_buff_head *fdefq = &l->failover_deferdq;
1349 struct tipc_msg *hdr = buf_msg(skb);
1350 struct sk_buff *iskb;
1351 int ipos = 0;
1352 int rc = 0;
1353 u16 seqno;
1354
1355 if (msg_type(hdr) == SYNCH_MSG) {
1356 kfree_skb(skb);
1357 return 0;
1358 }
1359
1360 /* Not a fragment? */
1361 if (likely(!msg_nof_fragms(hdr))) {
1362 if (unlikely(!tipc_msg_extract(skb, &iskb, &ipos))) {
1363 pr_warn_ratelimited("Unable to extract msg, defq: %d\n",
1364 skb_queue_len(fdefq));
1365 return 0;
1366 }
1367 kfree_skb(skb);
1368 } else {
1369 /* Set fragment type for buf_append */
1370 if (msg_fragm_no(hdr) == 1)
1371 msg_set_type(hdr, FIRST_FRAGMENT);
1372 else if (msg_fragm_no(hdr) < msg_nof_fragms(hdr))
1373 msg_set_type(hdr, FRAGMENT);
1374 else
1375 msg_set_type(hdr, LAST_FRAGMENT);
1376
1377 if (!tipc_buf_append(reasm_tnlmsg, &skb)) {
1378 /* Successful but non-complete reassembly? */
1379 if (*reasm_tnlmsg || link_is_bc_rcvlink(l))
1380 return 0;
1381 pr_warn_ratelimited("Unable to reassemble tunnel msg\n");
1382 return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1383 }
1384 iskb = skb;
1385 }
1386
1387 do {
1388 seqno = buf_seqno(iskb);
1389 if (unlikely(less(seqno, l->drop_point))) {
1390 kfree_skb(iskb);
1391 continue;
1392 }
1393 if (unlikely(seqno != l->drop_point)) {
1394 __tipc_skb_queue_sorted(fdefq, seqno, iskb);
1395 continue;
1396 }
1397
1398 l->drop_point++;
1399 if (!tipc_data_input(l, iskb, inputq))
1400 rc |= tipc_link_input(l, iskb, inputq, reasm_skb);
1401 if (unlikely(rc))
1402 break;
1403 } while ((iskb = __tipc_skb_dequeue(fdefq, l->drop_point)));
1404
1405 return rc;
1406 }
1407
1408 /**
1409 * tipc_get_gap_ack_blks - get Gap ACK blocks from PROTOCOL/STATE_MSG
1410 * @ga: returned pointer to the Gap ACK blocks if any
1411 * @l: the tipc link
1412 * @hdr: the PROTOCOL/STATE_MSG header
1413 * @uc: desired Gap ACK blocks type, i.e. unicast (= 1) or broadcast (= 0)
1414 *
1415 * Return: the total Gap ACK blocks size
1416 */
tipc_get_gap_ack_blks(struct tipc_gap_ack_blks ** ga,struct tipc_link * l,struct tipc_msg * hdr,bool uc)1417 u16 tipc_get_gap_ack_blks(struct tipc_gap_ack_blks **ga, struct tipc_link *l,
1418 struct tipc_msg *hdr, bool uc)
1419 {
1420 struct tipc_gap_ack_blks *p;
1421 u16 sz = 0;
1422
1423 /* Does peer support the Gap ACK blocks feature? */
1424 if (l->peer_caps & TIPC_GAP_ACK_BLOCK) {
1425 p = (struct tipc_gap_ack_blks *)msg_data(hdr);
1426 sz = ntohs(p->len);
1427 /* Sanity check */
1428 if (sz == struct_size(p, gacks, size_add(p->ugack_cnt, p->bgack_cnt))) {
1429 /* Good, check if the desired type exists */
1430 if ((uc && p->ugack_cnt) || (!uc && p->bgack_cnt))
1431 goto ok;
1432 /* Backward compatible: peer might not support bc, but uc? */
1433 } else if (uc && sz == struct_size(p, gacks, p->ugack_cnt)) {
1434 if (p->ugack_cnt) {
1435 p->bgack_cnt = 0;
1436 goto ok;
1437 }
1438 }
1439 }
1440 /* Other cases: ignore! */
1441 p = NULL;
1442
1443 ok:
1444 *ga = p;
1445 return sz;
1446 }
1447
__tipc_build_gap_ack_blks(struct tipc_gap_ack_blks * ga,struct tipc_link * l,u8 start_index)1448 static u8 __tipc_build_gap_ack_blks(struct tipc_gap_ack_blks *ga,
1449 struct tipc_link *l, u8 start_index)
1450 {
1451 struct tipc_gap_ack *gacks = &ga->gacks[start_index];
1452 struct sk_buff *skb = skb_peek(&l->deferdq);
1453 u16 expect, seqno = 0;
1454 u8 n = 0;
1455
1456 if (!skb)
1457 return 0;
1458
1459 expect = buf_seqno(skb);
1460 skb_queue_walk(&l->deferdq, skb) {
1461 seqno = buf_seqno(skb);
1462 if (unlikely(more(seqno, expect))) {
1463 gacks[n].ack = htons(expect - 1);
1464 gacks[n].gap = htons(seqno - expect);
1465 if (++n >= MAX_GAP_ACK_BLKS / 2) {
1466 pr_info_ratelimited("Gacks on %s: %d, ql: %d!\n",
1467 l->name, n,
1468 skb_queue_len(&l->deferdq));
1469 return n;
1470 }
1471 } else if (unlikely(less(seqno, expect))) {
1472 pr_warn("Unexpected skb in deferdq!\n");
1473 continue;
1474 }
1475 expect = seqno + 1;
1476 }
1477
1478 /* last block */
1479 gacks[n].ack = htons(seqno);
1480 gacks[n].gap = 0;
1481 n++;
1482 return n;
1483 }
1484
1485 /* tipc_build_gap_ack_blks - build Gap ACK blocks
1486 * @l: tipc unicast link
1487 * @hdr: the tipc message buffer to store the Gap ACK blocks after built
1488 *
1489 * The function builds Gap ACK blocks for both the unicast & broadcast receiver
1490 * links of a certain peer, the buffer after built has the network data format
1491 * as found at the struct tipc_gap_ack_blks definition.
1492 *
1493 * returns the actual allocated memory size
1494 */
tipc_build_gap_ack_blks(struct tipc_link * l,struct tipc_msg * hdr)1495 static u16 tipc_build_gap_ack_blks(struct tipc_link *l, struct tipc_msg *hdr)
1496 {
1497 struct tipc_link *bcl = l->bc_rcvlink;
1498 struct tipc_gap_ack_blks *ga;
1499 u16 len;
1500
1501 ga = (struct tipc_gap_ack_blks *)msg_data(hdr);
1502
1503 /* Start with broadcast link first */
1504 tipc_bcast_lock(bcl->net);
1505 msg_set_bcast_ack(hdr, bcl->rcv_nxt - 1);
1506 msg_set_bc_gap(hdr, link_bc_rcv_gap(bcl));
1507 ga->bgack_cnt = __tipc_build_gap_ack_blks(ga, bcl, 0);
1508 tipc_bcast_unlock(bcl->net);
1509
1510 /* Now for unicast link, but an explicit NACK only (???) */
1511 ga->ugack_cnt = (msg_seq_gap(hdr)) ?
1512 __tipc_build_gap_ack_blks(ga, l, ga->bgack_cnt) : 0;
1513
1514 /* Total len */
1515 len = struct_size(ga, gacks, size_add(ga->bgack_cnt, ga->ugack_cnt));
1516 ga->len = htons(len);
1517 return len;
1518 }
1519
1520 /* tipc_link_advance_transmq - advance TIPC link transmq queue by releasing
1521 * acked packets, also doing retransmissions if
1522 * gaps found
1523 * @l: tipc link with transmq queue to be advanced
1524 * @r: tipc link "receiver" i.e. in case of broadcast (= "l" if unicast)
1525 * @acked: seqno of last packet acked by peer without any gaps before
1526 * @gap: # of gap packets
1527 * @ga: buffer pointer to Gap ACK blocks from peer
1528 * @xmitq: queue for accumulating the retransmitted packets if any
1529 * @retransmitted: returned boolean value if a retransmission is really issued
1530 * @rc: returned code e.g. TIPC_LINK_DOWN_EVT if a repeated retransmit failures
1531 * happens (- unlikely case)
1532 *
1533 * Return: the number of packets released from the link transmq
1534 */
tipc_link_advance_transmq(struct tipc_link * l,struct tipc_link * r,u16 acked,u16 gap,struct tipc_gap_ack_blks * ga,struct sk_buff_head * xmitq,bool * retransmitted,int * rc)1535 static int tipc_link_advance_transmq(struct tipc_link *l, struct tipc_link *r,
1536 u16 acked, u16 gap,
1537 struct tipc_gap_ack_blks *ga,
1538 struct sk_buff_head *xmitq,
1539 bool *retransmitted, int *rc)
1540 {
1541 struct tipc_gap_ack_blks *last_ga = r->last_ga, *this_ga = NULL;
1542 struct tipc_gap_ack *gacks = NULL;
1543 struct sk_buff *skb, *_skb, *tmp;
1544 struct tipc_msg *hdr;
1545 u32 qlen = skb_queue_len(&l->transmq);
1546 u16 nacked = acked, ngap = gap, gack_cnt = 0;
1547 u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
1548 u16 ack = l->rcv_nxt - 1;
1549 u16 seqno, n = 0;
1550 u16 end = r->acked, start = end, offset = r->last_gap;
1551 u16 si = (last_ga) ? last_ga->start_index : 0;
1552 bool is_uc = !link_is_bc_sndlink(l);
1553 bool bc_has_acked = false;
1554
1555 trace_tipc_link_retrans(r, acked + 1, acked + gap, &l->transmq);
1556
1557 /* Determine Gap ACK blocks if any for the particular link */
1558 if (ga && is_uc) {
1559 /* Get the Gap ACKs, uc part */
1560 gack_cnt = ga->ugack_cnt;
1561 gacks = &ga->gacks[ga->bgack_cnt];
1562 } else if (ga) {
1563 /* Copy the Gap ACKs, bc part, for later renewal if needed */
1564 this_ga = kmemdup(ga, struct_size(ga, gacks, ga->bgack_cnt),
1565 GFP_ATOMIC);
1566 if (likely(this_ga)) {
1567 this_ga->start_index = 0;
1568 /* Start with the bc Gap ACKs */
1569 gack_cnt = this_ga->bgack_cnt;
1570 gacks = &this_ga->gacks[0];
1571 } else {
1572 /* Hmm, we can get in trouble..., simply ignore it */
1573 pr_warn_ratelimited("Ignoring bc Gap ACKs, no memory\n");
1574 }
1575 }
1576
1577 /* Advance the link transmq */
1578 skb_queue_walk_safe(&l->transmq, skb, tmp) {
1579 seqno = buf_seqno(skb);
1580
1581 next_gap_ack:
1582 if (less_eq(seqno, nacked)) {
1583 if (is_uc)
1584 goto release;
1585 /* Skip packets peer has already acked */
1586 if (!more(seqno, r->acked))
1587 continue;
1588 /* Get the next of last Gap ACK blocks */
1589 while (more(seqno, end)) {
1590 if (!last_ga || si >= last_ga->bgack_cnt)
1591 break;
1592 start = end + offset + 1;
1593 end = ntohs(last_ga->gacks[si].ack);
1594 offset = ntohs(last_ga->gacks[si].gap);
1595 si++;
1596 WARN_ONCE(more(start, end) ||
1597 (!offset &&
1598 si < last_ga->bgack_cnt) ||
1599 si > MAX_GAP_ACK_BLKS,
1600 "Corrupted Gap ACK: %d %d %d %d %d\n",
1601 start, end, offset, si,
1602 last_ga->bgack_cnt);
1603 }
1604 /* Check against the last Gap ACK block */
1605 if (tipc_in_range(seqno, start, end))
1606 continue;
1607 /* Update/release the packet peer is acking */
1608 bc_has_acked = true;
1609 if (--TIPC_SKB_CB(skb)->ackers)
1610 continue;
1611 release:
1612 /* release skb */
1613 __skb_unlink(skb, &l->transmq);
1614 kfree_skb(skb);
1615 } else if (less_eq(seqno, nacked + ngap)) {
1616 /* First gap: check if repeated retrans failures? */
1617 if (unlikely(seqno == acked + 1 &&
1618 link_retransmit_failure(l, r, rc))) {
1619 /* Ignore this bc Gap ACKs if any */
1620 kfree(this_ga);
1621 this_ga = NULL;
1622 break;
1623 }
1624 /* retransmit skb if unrestricted*/
1625 if (time_before(jiffies, TIPC_SKB_CB(skb)->nxt_retr))
1626 continue;
1627 tipc_link_set_skb_retransmit_time(skb, l);
1628 _skb = pskb_copy(skb, GFP_ATOMIC);
1629 if (!_skb)
1630 continue;
1631 hdr = buf_msg(_skb);
1632 msg_set_ack(hdr, ack);
1633 msg_set_bcast_ack(hdr, bc_ack);
1634 _skb->priority = TC_PRIO_CONTROL;
1635 __skb_queue_tail(xmitq, _skb);
1636 l->stats.retransmitted++;
1637 if (!is_uc)
1638 r->stats.retransmitted++;
1639 *retransmitted = true;
1640 /* Increase actual retrans counter & mark first time */
1641 if (!TIPC_SKB_CB(skb)->retr_cnt++)
1642 TIPC_SKB_CB(skb)->retr_stamp = jiffies;
1643 } else {
1644 /* retry with Gap ACK blocks if any */
1645 if (n >= gack_cnt)
1646 break;
1647 nacked = ntohs(gacks[n].ack);
1648 ngap = ntohs(gacks[n].gap);
1649 n++;
1650 goto next_gap_ack;
1651 }
1652 }
1653
1654 /* Renew last Gap ACK blocks for bc if needed */
1655 if (bc_has_acked) {
1656 if (this_ga) {
1657 kfree(last_ga);
1658 r->last_ga = this_ga;
1659 r->last_gap = gap;
1660 } else if (last_ga) {
1661 if (less(acked, start)) {
1662 si--;
1663 offset = start - acked - 1;
1664 } else if (less(acked, end)) {
1665 acked = end;
1666 }
1667 if (si < last_ga->bgack_cnt) {
1668 last_ga->start_index = si;
1669 r->last_gap = offset;
1670 } else {
1671 kfree(last_ga);
1672 r->last_ga = NULL;
1673 r->last_gap = 0;
1674 }
1675 } else {
1676 r->last_gap = 0;
1677 }
1678 r->acked = acked;
1679 } else {
1680 kfree(this_ga);
1681 }
1682
1683 return qlen - skb_queue_len(&l->transmq);
1684 }
1685
1686 /* tipc_link_build_state_msg: prepare link state message for transmission
1687 *
1688 * Note that sending of broadcast ack is coordinated among nodes, to reduce
1689 * risk of ack storms towards the sender
1690 */
tipc_link_build_state_msg(struct tipc_link * l,struct sk_buff_head * xmitq)1691 int tipc_link_build_state_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1692 {
1693 if (!l)
1694 return 0;
1695
1696 /* Broadcast ACK must be sent via a unicast link => defer to caller */
1697 if (link_is_bc_rcvlink(l)) {
1698 if (((l->rcv_nxt ^ tipc_own_addr(l->net)) & 0xf) != 0xf)
1699 return 0;
1700 l->rcv_unacked = 0;
1701
1702 /* Use snd_nxt to store peer's snd_nxt in broadcast rcv link */
1703 l->snd_nxt = l->rcv_nxt;
1704 return TIPC_LINK_SND_STATE;
1705 }
1706 /* Unicast ACK */
1707 l->rcv_unacked = 0;
1708 l->stats.sent_acks++;
1709 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, 0, xmitq);
1710 return 0;
1711 }
1712
1713 /* tipc_link_build_reset_msg: prepare link RESET or ACTIVATE message
1714 */
tipc_link_build_reset_msg(struct tipc_link * l,struct sk_buff_head * xmitq)1715 void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1716 {
1717 int mtyp = RESET_MSG;
1718 struct sk_buff *skb;
1719
1720 if (l->state == LINK_ESTABLISHING)
1721 mtyp = ACTIVATE_MSG;
1722
1723 tipc_link_build_proto_msg(l, mtyp, 0, 0, 0, 0, 0, xmitq);
1724
1725 /* Inform peer that this endpoint is going down if applicable */
1726 skb = skb_peek_tail(xmitq);
1727 if (skb && (l->state == LINK_RESET))
1728 msg_set_peer_stopping(buf_msg(skb), 1);
1729 }
1730
1731 /* tipc_link_build_nack_msg: prepare link nack message for transmission
1732 * Note that sending of broadcast NACK is coordinated among nodes, to
1733 * reduce the risk of NACK storms towards the sender
1734 */
tipc_link_build_nack_msg(struct tipc_link * l,struct sk_buff_head * xmitq)1735 static int tipc_link_build_nack_msg(struct tipc_link *l,
1736 struct sk_buff_head *xmitq)
1737 {
1738 u32 def_cnt = ++l->stats.deferred_recv;
1739 struct sk_buff_head *dfq = &l->deferdq;
1740 u32 defq_len = skb_queue_len(dfq);
1741 int match1, match2;
1742
1743 if (link_is_bc_rcvlink(l)) {
1744 match1 = def_cnt & 0xf;
1745 match2 = tipc_own_addr(l->net) & 0xf;
1746 if (match1 == match2)
1747 return TIPC_LINK_SND_STATE;
1748 return 0;
1749 }
1750
1751 if (defq_len >= 3 && !((defq_len - 3) % 16)) {
1752 u16 rcvgap = buf_seqno(skb_peek(dfq)) - l->rcv_nxt;
1753
1754 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0,
1755 rcvgap, 0, 0, xmitq);
1756 }
1757 return 0;
1758 }
1759
1760 /* tipc_link_rcv - process TIPC packets/messages arriving from off-node
1761 * @l: the link that should handle the message
1762 * @skb: TIPC packet
1763 * @xmitq: queue to place packets to be sent after this call
1764 */
tipc_link_rcv(struct tipc_link * l,struct sk_buff * skb,struct sk_buff_head * xmitq)1765 int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
1766 struct sk_buff_head *xmitq)
1767 {
1768 struct sk_buff_head *defq = &l->deferdq;
1769 struct tipc_msg *hdr = buf_msg(skb);
1770 u16 seqno, rcv_nxt, win_lim;
1771 int released = 0;
1772 int rc = 0;
1773
1774 /* Verify and update link state */
1775 if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
1776 return tipc_link_proto_rcv(l, skb, xmitq);
1777
1778 /* Don't send probe at next timeout expiration */
1779 l->silent_intv_cnt = 0;
1780
1781 do {
1782 hdr = buf_msg(skb);
1783 seqno = msg_seqno(hdr);
1784 rcv_nxt = l->rcv_nxt;
1785 win_lim = rcv_nxt + TIPC_MAX_LINK_WIN;
1786
1787 if (unlikely(!tipc_link_is_up(l))) {
1788 if (l->state == LINK_ESTABLISHING)
1789 rc = TIPC_LINK_UP_EVT;
1790 kfree_skb(skb);
1791 break;
1792 }
1793
1794 /* Drop if outside receive window */
1795 if (unlikely(less(seqno, rcv_nxt) || more(seqno, win_lim))) {
1796 l->stats.duplicates++;
1797 kfree_skb(skb);
1798 break;
1799 }
1800 released += tipc_link_advance_transmq(l, l, msg_ack(hdr), 0,
1801 NULL, NULL, NULL, NULL);
1802
1803 /* Defer delivery if sequence gap */
1804 if (unlikely(seqno != rcv_nxt)) {
1805 if (!__tipc_skb_queue_sorted(defq, seqno, skb))
1806 l->stats.duplicates++;
1807 rc |= tipc_link_build_nack_msg(l, xmitq);
1808 break;
1809 }
1810
1811 /* Deliver packet */
1812 l->rcv_nxt++;
1813 l->stats.recv_pkts++;
1814
1815 if (unlikely(msg_user(hdr) == TUNNEL_PROTOCOL))
1816 rc |= tipc_link_tnl_rcv(l, skb, l->inputq);
1817 else if (!tipc_data_input(l, skb, l->inputq))
1818 rc |= tipc_link_input(l, skb, l->inputq, &l->reasm_buf);
1819 if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
1820 rc |= tipc_link_build_state_msg(l, xmitq);
1821 if (unlikely(rc & ~TIPC_LINK_SND_STATE))
1822 break;
1823 } while ((skb = __tipc_skb_dequeue(defq, l->rcv_nxt)));
1824
1825 /* Forward queues and wake up waiting users */
1826 if (released) {
1827 tipc_link_update_cwin(l, released, 0);
1828 tipc_link_advance_backlog(l, xmitq);
1829 if (unlikely(!skb_queue_empty(&l->wakeupq)))
1830 link_prepare_wakeup(l);
1831 }
1832 return rc;
1833 }
1834
tipc_link_build_proto_msg(struct tipc_link * l,int mtyp,bool probe,bool probe_reply,u16 rcvgap,int tolerance,int priority,struct sk_buff_head * xmitq)1835 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
1836 bool probe_reply, u16 rcvgap,
1837 int tolerance, int priority,
1838 struct sk_buff_head *xmitq)
1839 {
1840 struct tipc_mon_state *mstate = &l->mon_state;
1841 struct sk_buff_head *dfq = &l->deferdq;
1842 struct tipc_link *bcl = l->bc_rcvlink;
1843 struct tipc_msg *hdr;
1844 struct sk_buff *skb;
1845 bool node_up = tipc_link_is_up(bcl);
1846 u16 glen = 0, bc_rcvgap = 0;
1847 int dlen = 0;
1848 void *data;
1849
1850 /* Don't send protocol message during reset or link failover */
1851 if (tipc_link_is_blocked(l))
1852 return;
1853
1854 if (!tipc_link_is_up(l) && (mtyp == STATE_MSG))
1855 return;
1856
1857 if ((probe || probe_reply) && !skb_queue_empty(dfq))
1858 rcvgap = buf_seqno(skb_peek(dfq)) - l->rcv_nxt;
1859
1860 skb = tipc_msg_create(LINK_PROTOCOL, mtyp, INT_H_SIZE,
1861 tipc_max_domain_size + MAX_GAP_ACK_BLKS_SZ,
1862 l->addr, tipc_own_addr(l->net), 0, 0, 0);
1863 if (!skb)
1864 return;
1865
1866 hdr = buf_msg(skb);
1867 data = msg_data(hdr);
1868 msg_set_session(hdr, l->session);
1869 msg_set_bearer_id(hdr, l->bearer_id);
1870 msg_set_net_plane(hdr, l->net_plane);
1871 msg_set_next_sent(hdr, l->snd_nxt);
1872 msg_set_ack(hdr, l->rcv_nxt - 1);
1873 msg_set_bcast_ack(hdr, bcl->rcv_nxt - 1);
1874 msg_set_bc_ack_invalid(hdr, !node_up);
1875 msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
1876 msg_set_link_tolerance(hdr, tolerance);
1877 msg_set_linkprio(hdr, priority);
1878 msg_set_redundant_link(hdr, node_up);
1879 msg_set_seq_gap(hdr, 0);
1880 msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2);
1881
1882 if (mtyp == STATE_MSG) {
1883 if (l->peer_caps & TIPC_LINK_PROTO_SEQNO)
1884 msg_set_seqno(hdr, l->snd_nxt_state++);
1885 msg_set_seq_gap(hdr, rcvgap);
1886 bc_rcvgap = link_bc_rcv_gap(bcl);
1887 msg_set_bc_gap(hdr, bc_rcvgap);
1888 msg_set_probe(hdr, probe);
1889 msg_set_is_keepalive(hdr, probe || probe_reply);
1890 if (l->peer_caps & TIPC_GAP_ACK_BLOCK)
1891 glen = tipc_build_gap_ack_blks(l, hdr);
1892 tipc_mon_prep(l->net, data + glen, &dlen, mstate, l->bearer_id);
1893 msg_set_size(hdr, INT_H_SIZE + glen + dlen);
1894 skb_trim(skb, INT_H_SIZE + glen + dlen);
1895 l->stats.sent_states++;
1896 l->rcv_unacked = 0;
1897 } else {
1898 /* RESET_MSG or ACTIVATE_MSG */
1899 if (mtyp == ACTIVATE_MSG) {
1900 msg_set_dest_session_valid(hdr, 1);
1901 msg_set_dest_session(hdr, l->peer_session);
1902 }
1903 msg_set_max_pkt(hdr, l->advertised_mtu);
1904 strcpy(data, l->if_name);
1905 msg_set_size(hdr, INT_H_SIZE + TIPC_MAX_IF_NAME);
1906 skb_trim(skb, INT_H_SIZE + TIPC_MAX_IF_NAME);
1907 }
1908 if (probe)
1909 l->stats.sent_probes++;
1910 if (rcvgap)
1911 l->stats.sent_nacks++;
1912 if (bc_rcvgap)
1913 bcl->stats.sent_nacks++;
1914 skb->priority = TC_PRIO_CONTROL;
1915 __skb_queue_tail(xmitq, skb);
1916 trace_tipc_proto_build(skb, false, l->name);
1917 }
1918
tipc_link_create_dummy_tnl_msg(struct tipc_link * l,struct sk_buff_head * xmitq)1919 void tipc_link_create_dummy_tnl_msg(struct tipc_link *l,
1920 struct sk_buff_head *xmitq)
1921 {
1922 u32 onode = tipc_own_addr(l->net);
1923 struct tipc_msg *hdr, *ihdr;
1924 struct sk_buff_head tnlq;
1925 struct sk_buff *skb;
1926 u32 dnode = l->addr;
1927
1928 __skb_queue_head_init(&tnlq);
1929 skb = tipc_msg_create(TUNNEL_PROTOCOL, FAILOVER_MSG,
1930 INT_H_SIZE, BASIC_H_SIZE,
1931 dnode, onode, 0, 0, 0);
1932 if (!skb) {
1933 pr_warn("%sunable to create tunnel packet\n", link_co_err);
1934 return;
1935 }
1936
1937 hdr = buf_msg(skb);
1938 msg_set_msgcnt(hdr, 1);
1939 msg_set_bearer_id(hdr, l->peer_bearer_id);
1940
1941 ihdr = (struct tipc_msg *)msg_data(hdr);
1942 tipc_msg_init(onode, ihdr, TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
1943 BASIC_H_SIZE, dnode);
1944 msg_set_errcode(ihdr, TIPC_ERR_NO_PORT);
1945 __skb_queue_tail(&tnlq, skb);
1946 tipc_link_xmit(l, &tnlq, xmitq);
1947 }
1948
1949 /* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets
1950 * with contents of the link's transmit and backlog queues.
1951 */
tipc_link_tnl_prepare(struct tipc_link * l,struct tipc_link * tnl,int mtyp,struct sk_buff_head * xmitq)1952 void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
1953 int mtyp, struct sk_buff_head *xmitq)
1954 {
1955 struct sk_buff_head *fdefq = &tnl->failover_deferdq;
1956 struct sk_buff *skb, *tnlskb;
1957 struct tipc_msg *hdr, tnlhdr;
1958 struct sk_buff_head *queue = &l->transmq;
1959 struct sk_buff_head tmpxq, tnlq, frags;
1960 u16 pktlen, pktcnt, seqno = l->snd_nxt;
1961 bool pktcnt_need_update = false;
1962 u16 syncpt;
1963 int rc;
1964
1965 if (!tnl)
1966 return;
1967
1968 __skb_queue_head_init(&tnlq);
1969 /* Link Synching:
1970 * From now on, send only one single ("dummy") SYNCH message
1971 * to peer. The SYNCH message does not contain any data, just
1972 * a header conveying the synch point to the peer.
1973 */
1974 if (mtyp == SYNCH_MSG && (tnl->peer_caps & TIPC_TUNNEL_ENHANCED)) {
1975 tnlskb = tipc_msg_create(TUNNEL_PROTOCOL, SYNCH_MSG,
1976 INT_H_SIZE, 0, l->addr,
1977 tipc_own_addr(l->net),
1978 0, 0, 0);
1979 if (!tnlskb) {
1980 pr_warn("%sunable to create dummy SYNCH_MSG\n",
1981 link_co_err);
1982 return;
1983 }
1984
1985 hdr = buf_msg(tnlskb);
1986 syncpt = l->snd_nxt + skb_queue_len(&l->backlogq) - 1;
1987 msg_set_syncpt(hdr, syncpt);
1988 msg_set_bearer_id(hdr, l->peer_bearer_id);
1989 __skb_queue_tail(&tnlq, tnlskb);
1990 tipc_link_xmit(tnl, &tnlq, xmitq);
1991 return;
1992 }
1993
1994 __skb_queue_head_init(&tmpxq);
1995 __skb_queue_head_init(&frags);
1996 /* At least one packet required for safe algorithm => add dummy */
1997 skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
1998 BASIC_H_SIZE, 0, l->addr, tipc_own_addr(l->net),
1999 0, 0, TIPC_ERR_NO_PORT);
2000 if (!skb) {
2001 pr_warn("%sunable to create tunnel packet\n", link_co_err);
2002 return;
2003 }
2004 __skb_queue_tail(&tnlq, skb);
2005 tipc_link_xmit(l, &tnlq, &tmpxq);
2006 __skb_queue_purge(&tmpxq);
2007
2008 /* Initialize reusable tunnel packet header */
2009 tipc_msg_init(tipc_own_addr(l->net), &tnlhdr, TUNNEL_PROTOCOL,
2010 mtyp, INT_H_SIZE, l->addr);
2011 if (mtyp == SYNCH_MSG)
2012 pktcnt = l->snd_nxt - buf_seqno(skb_peek(&l->transmq));
2013 else
2014 pktcnt = skb_queue_len(&l->transmq);
2015 pktcnt += skb_queue_len(&l->backlogq);
2016 msg_set_msgcnt(&tnlhdr, pktcnt);
2017 msg_set_bearer_id(&tnlhdr, l->peer_bearer_id);
2018 tnl:
2019 /* Wrap each packet into a tunnel packet */
2020 skb_queue_walk(queue, skb) {
2021 hdr = buf_msg(skb);
2022 if (queue == &l->backlogq)
2023 msg_set_seqno(hdr, seqno++);
2024 pktlen = msg_size(hdr);
2025
2026 /* Tunnel link MTU is not large enough? This could be
2027 * due to:
2028 * 1) Link MTU has just changed or set differently;
2029 * 2) Or FAILOVER on the top of a SYNCH message
2030 *
2031 * The 2nd case should not happen if peer supports
2032 * TIPC_TUNNEL_ENHANCED
2033 */
2034 if (pktlen > tnl->mtu - INT_H_SIZE) {
2035 if (mtyp == FAILOVER_MSG &&
2036 (tnl->peer_caps & TIPC_TUNNEL_ENHANCED)) {
2037 rc = tipc_msg_fragment(skb, &tnlhdr, tnl->mtu,
2038 &frags);
2039 if (rc) {
2040 pr_warn("%sunable to frag msg: rc %d\n",
2041 link_co_err, rc);
2042 return;
2043 }
2044 pktcnt += skb_queue_len(&frags) - 1;
2045 pktcnt_need_update = true;
2046 skb_queue_splice_tail_init(&frags, &tnlq);
2047 continue;
2048 }
2049 /* Unluckily, peer doesn't have TIPC_TUNNEL_ENHANCED
2050 * => Just warn it and return!
2051 */
2052 pr_warn_ratelimited("%stoo large msg <%d, %d>: %d!\n",
2053 link_co_err, msg_user(hdr),
2054 msg_type(hdr), msg_size(hdr));
2055 return;
2056 }
2057
2058 msg_set_size(&tnlhdr, pktlen + INT_H_SIZE);
2059 tnlskb = tipc_buf_acquire(pktlen + INT_H_SIZE, GFP_ATOMIC);
2060 if (!tnlskb) {
2061 pr_warn("%sunable to send packet\n", link_co_err);
2062 return;
2063 }
2064 skb_copy_to_linear_data(tnlskb, &tnlhdr, INT_H_SIZE);
2065 skb_copy_to_linear_data_offset(tnlskb, INT_H_SIZE, hdr, pktlen);
2066 __skb_queue_tail(&tnlq, tnlskb);
2067 }
2068 if (queue != &l->backlogq) {
2069 queue = &l->backlogq;
2070 goto tnl;
2071 }
2072
2073 if (pktcnt_need_update)
2074 skb_queue_walk(&tnlq, skb) {
2075 hdr = buf_msg(skb);
2076 msg_set_msgcnt(hdr, pktcnt);
2077 }
2078
2079 tipc_link_xmit(tnl, &tnlq, xmitq);
2080
2081 if (mtyp == FAILOVER_MSG) {
2082 tnl->drop_point = l->rcv_nxt;
2083 tnl->failover_reasm_skb = l->reasm_buf;
2084 l->reasm_buf = NULL;
2085
2086 /* Failover the link's deferdq */
2087 if (unlikely(!skb_queue_empty(fdefq))) {
2088 pr_warn("Link failover deferdq not empty: %d!\n",
2089 skb_queue_len(fdefq));
2090 __skb_queue_purge(fdefq);
2091 }
2092 skb_queue_splice_init(&l->deferdq, fdefq);
2093 }
2094 }
2095
2096 /**
2097 * tipc_link_failover_prepare() - prepare tnl for link failover
2098 *
2099 * This is a special version of the precursor - tipc_link_tnl_prepare(),
2100 * see the tipc_node_link_failover() for details
2101 *
2102 * @l: failover link
2103 * @tnl: tunnel link
2104 * @xmitq: queue for messages to be xmited
2105 */
tipc_link_failover_prepare(struct tipc_link * l,struct tipc_link * tnl,struct sk_buff_head * xmitq)2106 void tipc_link_failover_prepare(struct tipc_link *l, struct tipc_link *tnl,
2107 struct sk_buff_head *xmitq)
2108 {
2109 struct sk_buff_head *fdefq = &tnl->failover_deferdq;
2110
2111 tipc_link_create_dummy_tnl_msg(tnl, xmitq);
2112
2113 /* This failover link endpoint was never established before,
2114 * so it has not received anything from peer.
2115 * Otherwise, it must be a normal failover situation or the
2116 * node has entered SELF_DOWN_PEER_LEAVING and both peer nodes
2117 * would have to start over from scratch instead.
2118 */
2119 tnl->drop_point = 1;
2120 tnl->failover_reasm_skb = NULL;
2121
2122 /* Initiate the link's failover deferdq */
2123 if (unlikely(!skb_queue_empty(fdefq))) {
2124 pr_warn("Link failover deferdq not empty: %d!\n",
2125 skb_queue_len(fdefq));
2126 __skb_queue_purge(fdefq);
2127 }
2128 }
2129
2130 /* tipc_link_validate_msg(): validate message against current link state
2131 * Returns true if message should be accepted, otherwise false
2132 */
tipc_link_validate_msg(struct tipc_link * l,struct tipc_msg * hdr)2133 bool tipc_link_validate_msg(struct tipc_link *l, struct tipc_msg *hdr)
2134 {
2135 u16 curr_session = l->peer_session;
2136 u16 session = msg_session(hdr);
2137 int mtyp = msg_type(hdr);
2138
2139 if (msg_user(hdr) != LINK_PROTOCOL)
2140 return true;
2141
2142 switch (mtyp) {
2143 case RESET_MSG:
2144 if (!l->in_session)
2145 return true;
2146 /* Accept only RESET with new session number */
2147 return more(session, curr_session);
2148 case ACTIVATE_MSG:
2149 if (!l->in_session)
2150 return true;
2151 /* Accept only ACTIVATE with new or current session number */
2152 return !less(session, curr_session);
2153 case STATE_MSG:
2154 /* Accept only STATE with current session number */
2155 if (!l->in_session)
2156 return false;
2157 if (session != curr_session)
2158 return false;
2159 /* Extra sanity check */
2160 if (!tipc_link_is_up(l) && msg_ack(hdr))
2161 return false;
2162 if (!(l->peer_caps & TIPC_LINK_PROTO_SEQNO))
2163 return true;
2164 /* Accept only STATE with new sequence number */
2165 return !less(msg_seqno(hdr), l->rcv_nxt_state);
2166 default:
2167 return false;
2168 }
2169 }
2170
2171 /* tipc_link_proto_rcv(): receive link level protocol message :
2172 * Note that network plane id propagates through the network, and may
2173 * change at any time. The node with lowest numerical id determines
2174 * network plane
2175 */
tipc_link_proto_rcv(struct tipc_link * l,struct sk_buff * skb,struct sk_buff_head * xmitq)2176 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
2177 struct sk_buff_head *xmitq)
2178 {
2179 struct tipc_msg *hdr = buf_msg(skb);
2180 struct tipc_gap_ack_blks *ga = NULL;
2181 bool reply = msg_probe(hdr), retransmitted = false;
2182 u32 dlen = msg_data_sz(hdr), glen = 0, msg_max;
2183 u16 peers_snd_nxt = msg_next_sent(hdr);
2184 u16 peers_tol = msg_link_tolerance(hdr);
2185 u16 peers_prio = msg_linkprio(hdr);
2186 u16 gap = msg_seq_gap(hdr);
2187 u16 ack = msg_ack(hdr);
2188 u16 rcv_nxt = l->rcv_nxt;
2189 u16 rcvgap = 0;
2190 int mtyp = msg_type(hdr);
2191 int rc = 0, released;
2192 char *if_name;
2193 void *data;
2194
2195 trace_tipc_proto_rcv(skb, false, l->name);
2196
2197 if (dlen > U16_MAX)
2198 goto exit;
2199
2200 if (tipc_link_is_blocked(l) || !xmitq)
2201 goto exit;
2202
2203 if (tipc_own_addr(l->net) > msg_prevnode(hdr))
2204 l->net_plane = msg_net_plane(hdr);
2205
2206 if (skb_linearize(skb))
2207 goto exit;
2208
2209 hdr = buf_msg(skb);
2210 data = msg_data(hdr);
2211
2212 if (!tipc_link_validate_msg(l, hdr)) {
2213 trace_tipc_skb_dump(skb, false, "PROTO invalid (1)!");
2214 trace_tipc_link_dump(l, TIPC_DUMP_NONE, "PROTO invalid (1)!");
2215 goto exit;
2216 }
2217
2218 switch (mtyp) {
2219 case RESET_MSG:
2220 case ACTIVATE_MSG:
2221 msg_max = msg_max_pkt(hdr);
2222 if (msg_max < tipc_bearer_min_mtu(l->net, l->bearer_id))
2223 break;
2224 /* Complete own link name with peer's interface name */
2225 if_name = strrchr(l->name, ':') + 1;
2226 if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME)
2227 break;
2228 if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME)
2229 break;
2230 strncpy(if_name, data, TIPC_MAX_IF_NAME);
2231
2232 /* Update own tolerance if peer indicates a non-zero value */
2233 if (tipc_in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL)) {
2234 l->tolerance = peers_tol;
2235 l->bc_rcvlink->tolerance = peers_tol;
2236 }
2237 /* Update own priority if peer's priority is higher */
2238 if (tipc_in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
2239 l->priority = peers_prio;
2240
2241 /* If peer is going down we want full re-establish cycle */
2242 if (msg_peer_stopping(hdr)) {
2243 rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
2244 break;
2245 }
2246
2247 /* If this endpoint was re-created while peer was ESTABLISHING
2248 * it doesn't know current session number. Force re-synch.
2249 */
2250 if (mtyp == ACTIVATE_MSG && msg_dest_session_valid(hdr) &&
2251 l->session != msg_dest_session(hdr)) {
2252 if (less(l->session, msg_dest_session(hdr)))
2253 l->session = msg_dest_session(hdr) + 1;
2254 break;
2255 }
2256
2257 /* ACTIVATE_MSG serves as PEER_RESET if link is already down */
2258 if (mtyp == RESET_MSG || !tipc_link_is_up(l))
2259 rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
2260
2261 /* ACTIVATE_MSG takes up link if it was already locally reset */
2262 if (mtyp == ACTIVATE_MSG && l->state == LINK_ESTABLISHING)
2263 rc = TIPC_LINK_UP_EVT;
2264
2265 l->peer_session = msg_session(hdr);
2266 l->in_session = true;
2267 l->peer_bearer_id = msg_bearer_id(hdr);
2268 if (l->mtu > msg_max)
2269 l->mtu = msg_max;
2270 break;
2271
2272 case STATE_MSG:
2273 /* Validate Gap ACK blocks, drop if invalid */
2274 glen = tipc_get_gap_ack_blks(&ga, l, hdr, true);
2275 if (glen > dlen)
2276 break;
2277
2278 l->rcv_nxt_state = msg_seqno(hdr) + 1;
2279
2280 /* Update own tolerance if peer indicates a non-zero value */
2281 if (tipc_in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL)) {
2282 l->tolerance = peers_tol;
2283 l->bc_rcvlink->tolerance = peers_tol;
2284 }
2285 /* Update own prio if peer indicates a different value */
2286 if ((peers_prio != l->priority) &&
2287 tipc_in_range(peers_prio, 1, TIPC_MAX_LINK_PRI)) {
2288 l->priority = peers_prio;
2289 rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
2290 }
2291
2292 l->silent_intv_cnt = 0;
2293 l->stats.recv_states++;
2294 if (msg_probe(hdr))
2295 l->stats.recv_probes++;
2296
2297 if (!tipc_link_is_up(l)) {
2298 if (l->state == LINK_ESTABLISHING)
2299 rc = TIPC_LINK_UP_EVT;
2300 break;
2301 }
2302
2303 tipc_mon_rcv(l->net, data + glen, dlen - glen, l->addr,
2304 &l->mon_state, l->bearer_id);
2305
2306 /* Send NACK if peer has sent pkts we haven't received yet */
2307 if ((reply || msg_is_keepalive(hdr)) &&
2308 more(peers_snd_nxt, rcv_nxt) &&
2309 !tipc_link_is_synching(l) &&
2310 skb_queue_empty(&l->deferdq))
2311 rcvgap = peers_snd_nxt - l->rcv_nxt;
2312 if (rcvgap || reply)
2313 tipc_link_build_proto_msg(l, STATE_MSG, 0, reply,
2314 rcvgap, 0, 0, xmitq);
2315
2316 released = tipc_link_advance_transmq(l, l, ack, gap, ga, xmitq,
2317 &retransmitted, &rc);
2318 if (gap)
2319 l->stats.recv_nacks++;
2320 if (released || retransmitted)
2321 tipc_link_update_cwin(l, released, retransmitted);
2322 if (released)
2323 tipc_link_advance_backlog(l, xmitq);
2324 if (unlikely(!skb_queue_empty(&l->wakeupq)))
2325 link_prepare_wakeup(l);
2326 }
2327 exit:
2328 kfree_skb(skb);
2329 return rc;
2330 }
2331
2332 /* tipc_link_build_bc_proto_msg() - create broadcast protocol message
2333 */
tipc_link_build_bc_proto_msg(struct tipc_link * l,bool bcast,u16 peers_snd_nxt,struct sk_buff_head * xmitq)2334 static bool tipc_link_build_bc_proto_msg(struct tipc_link *l, bool bcast,
2335 u16 peers_snd_nxt,
2336 struct sk_buff_head *xmitq)
2337 {
2338 struct sk_buff *skb;
2339 struct tipc_msg *hdr;
2340 struct sk_buff *dfrd_skb = skb_peek(&l->deferdq);
2341 u16 ack = l->rcv_nxt - 1;
2342 u16 gap_to = peers_snd_nxt - 1;
2343
2344 skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
2345 0, l->addr, tipc_own_addr(l->net), 0, 0, 0);
2346 if (!skb)
2347 return false;
2348 hdr = buf_msg(skb);
2349 msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
2350 msg_set_bcast_ack(hdr, ack);
2351 msg_set_bcgap_after(hdr, ack);
2352 if (dfrd_skb)
2353 gap_to = buf_seqno(dfrd_skb) - 1;
2354 msg_set_bcgap_to(hdr, gap_to);
2355 msg_set_non_seq(hdr, bcast);
2356 __skb_queue_tail(xmitq, skb);
2357 return true;
2358 }
2359
2360 /* tipc_link_build_bc_init_msg() - synchronize broadcast link endpoints.
2361 *
2362 * Give a newly added peer node the sequence number where it should
2363 * start receiving and acking broadcast packets.
2364 */
tipc_link_build_bc_init_msg(struct tipc_link * l,struct sk_buff_head * xmitq)2365 static void tipc_link_build_bc_init_msg(struct tipc_link *l,
2366 struct sk_buff_head *xmitq)
2367 {
2368 struct sk_buff_head list;
2369
2370 __skb_queue_head_init(&list);
2371 if (!tipc_link_build_bc_proto_msg(l->bc_rcvlink, false, 0, &list))
2372 return;
2373 msg_set_bc_ack_invalid(buf_msg(skb_peek(&list)), true);
2374 tipc_link_xmit(l, &list, xmitq);
2375 }
2376
2377 /* tipc_link_bc_init_rcv - receive initial broadcast synch data from peer
2378 */
tipc_link_bc_init_rcv(struct tipc_link * l,struct tipc_msg * hdr)2379 void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr)
2380 {
2381 int mtyp = msg_type(hdr);
2382 u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
2383
2384 if (tipc_link_is_up(l))
2385 return;
2386
2387 if (msg_user(hdr) == BCAST_PROTOCOL) {
2388 l->rcv_nxt = peers_snd_nxt;
2389 l->state = LINK_ESTABLISHED;
2390 return;
2391 }
2392
2393 if (l->peer_caps & TIPC_BCAST_SYNCH)
2394 return;
2395
2396 if (msg_peer_node_is_up(hdr))
2397 return;
2398
2399 /* Compatibility: accept older, less safe initial synch data */
2400 if ((mtyp == RESET_MSG) || (mtyp == ACTIVATE_MSG))
2401 l->rcv_nxt = peers_snd_nxt;
2402 }
2403
2404 /* tipc_link_bc_sync_rcv - update rcv link according to peer's send state
2405 */
tipc_link_bc_sync_rcv(struct tipc_link * l,struct tipc_msg * hdr,struct sk_buff_head * xmitq)2406 int tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
2407 struct sk_buff_head *xmitq)
2408 {
2409 u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
2410 int rc = 0;
2411
2412 if (!tipc_link_is_up(l))
2413 return rc;
2414
2415 if (!msg_peer_node_is_up(hdr))
2416 return rc;
2417
2418 /* Open when peer acknowledges our bcast init msg (pkt #1) */
2419 if (msg_ack(hdr))
2420 l->bc_peer_is_up = true;
2421
2422 if (!l->bc_peer_is_up)
2423 return rc;
2424
2425 /* Ignore if peers_snd_nxt goes beyond receive window */
2426 if (more(peers_snd_nxt, l->rcv_nxt + l->window))
2427 return rc;
2428
2429 l->snd_nxt = peers_snd_nxt;
2430 if (link_bc_rcv_gap(l))
2431 rc |= TIPC_LINK_SND_STATE;
2432
2433 /* Return now if sender supports nack via STATE messages */
2434 if (l->peer_caps & TIPC_BCAST_STATE_NACK)
2435 return rc;
2436
2437 /* Otherwise, be backwards compatible */
2438
2439 if (!more(peers_snd_nxt, l->rcv_nxt)) {
2440 l->nack_state = BC_NACK_SND_CONDITIONAL;
2441 return 0;
2442 }
2443
2444 /* Don't NACK if one was recently sent or peeked */
2445 if (l->nack_state == BC_NACK_SND_SUPPRESS) {
2446 l->nack_state = BC_NACK_SND_UNCONDITIONAL;
2447 return 0;
2448 }
2449
2450 /* Conditionally delay NACK sending until next synch rcv */
2451 if (l->nack_state == BC_NACK_SND_CONDITIONAL) {
2452 l->nack_state = BC_NACK_SND_UNCONDITIONAL;
2453 if ((peers_snd_nxt - l->rcv_nxt) < TIPC_MIN_LINK_WIN)
2454 return 0;
2455 }
2456
2457 /* Send NACK now but suppress next one */
2458 tipc_link_build_bc_proto_msg(l, true, peers_snd_nxt, xmitq);
2459 l->nack_state = BC_NACK_SND_SUPPRESS;
2460 return 0;
2461 }
2462
tipc_link_bc_ack_rcv(struct tipc_link * r,u16 acked,u16 gap,struct tipc_gap_ack_blks * ga,struct sk_buff_head * xmitq,struct sk_buff_head * retrq)2463 int tipc_link_bc_ack_rcv(struct tipc_link *r, u16 acked, u16 gap,
2464 struct tipc_gap_ack_blks *ga,
2465 struct sk_buff_head *xmitq,
2466 struct sk_buff_head *retrq)
2467 {
2468 struct tipc_link *l = r->bc_sndlink;
2469 bool unused = false;
2470 int rc = 0;
2471
2472 if (!tipc_link_is_up(r) || !r->bc_peer_is_up)
2473 return 0;
2474
2475 if (gap) {
2476 l->stats.recv_nacks++;
2477 r->stats.recv_nacks++;
2478 }
2479
2480 if (less(acked, r->acked) || (acked == r->acked && !gap && !ga))
2481 return 0;
2482
2483 trace_tipc_link_bc_ack(r, acked, gap, &l->transmq);
2484 tipc_link_advance_transmq(l, r, acked, gap, ga, retrq, &unused, &rc);
2485
2486 tipc_link_advance_backlog(l, xmitq);
2487 if (unlikely(!skb_queue_empty(&l->wakeupq)))
2488 link_prepare_wakeup(l);
2489
2490 return rc;
2491 }
2492
2493 /* tipc_link_bc_nack_rcv(): receive broadcast nack message
2494 * This function is here for backwards compatibility, since
2495 * no BCAST_PROTOCOL/STATE messages occur from TIPC v2.5.
2496 */
tipc_link_bc_nack_rcv(struct tipc_link * l,struct sk_buff * skb,struct sk_buff_head * xmitq)2497 int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
2498 struct sk_buff_head *xmitq)
2499 {
2500 struct tipc_msg *hdr = buf_msg(skb);
2501 u32 dnode = msg_destnode(hdr);
2502 int mtyp = msg_type(hdr);
2503 u16 acked = msg_bcast_ack(hdr);
2504 u16 from = acked + 1;
2505 u16 to = msg_bcgap_to(hdr);
2506 u16 peers_snd_nxt = to + 1;
2507 int rc = 0;
2508
2509 kfree_skb(skb);
2510
2511 if (!tipc_link_is_up(l) || !l->bc_peer_is_up)
2512 return 0;
2513
2514 if (mtyp != STATE_MSG)
2515 return 0;
2516
2517 if (dnode == tipc_own_addr(l->net)) {
2518 rc = tipc_link_bc_ack_rcv(l, acked, to - acked, NULL, xmitq,
2519 xmitq);
2520 l->stats.recv_nacks++;
2521 return rc;
2522 }
2523
2524 /* Msg for other node => suppress own NACK at next sync if applicable */
2525 if (more(peers_snd_nxt, l->rcv_nxt) && !less(l->rcv_nxt, from))
2526 l->nack_state = BC_NACK_SND_SUPPRESS;
2527
2528 return 0;
2529 }
2530
tipc_link_set_queue_limits(struct tipc_link * l,u32 min_win,u32 max_win)2531 void tipc_link_set_queue_limits(struct tipc_link *l, u32 min_win, u32 max_win)
2532 {
2533 int max_bulk = TIPC_MAX_PUBL / (l->mtu / ITEM_SIZE);
2534
2535 l->min_win = min_win;
2536 l->ssthresh = max_win;
2537 l->max_win = max_win;
2538 l->window = min_win;
2539 l->backlog[TIPC_LOW_IMPORTANCE].limit = min_win * 2;
2540 l->backlog[TIPC_MEDIUM_IMPORTANCE].limit = min_win * 4;
2541 l->backlog[TIPC_HIGH_IMPORTANCE].limit = min_win * 6;
2542 l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = min_win * 8;
2543 l->backlog[TIPC_SYSTEM_IMPORTANCE].limit = max_bulk;
2544 }
2545
2546 /**
2547 * tipc_link_reset_stats - reset link statistics
2548 * @l: pointer to link
2549 */
tipc_link_reset_stats(struct tipc_link * l)2550 void tipc_link_reset_stats(struct tipc_link *l)
2551 {
2552 memset(&l->stats, 0, sizeof(l->stats));
2553 }
2554
link_print(struct tipc_link * l,const char * str)2555 static void link_print(struct tipc_link *l, const char *str)
2556 {
2557 struct sk_buff *hskb = skb_peek(&l->transmq);
2558 u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt - 1;
2559 u16 tail = l->snd_nxt - 1;
2560
2561 pr_info("%s Link <%s> state %x\n", str, l->name, l->state);
2562 pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n",
2563 skb_queue_len(&l->transmq), head, tail,
2564 skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt);
2565 }
2566
2567 /* Parse and validate nested (link) properties valid for media, bearer and link
2568 */
tipc_nl_parse_link_prop(struct nlattr * prop,struct nlattr * props[])2569 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
2570 {
2571 int err;
2572
2573 err = nla_parse_nested_deprecated(props, TIPC_NLA_PROP_MAX, prop,
2574 tipc_nl_prop_policy, NULL);
2575 if (err)
2576 return err;
2577
2578 if (props[TIPC_NLA_PROP_PRIO]) {
2579 u32 prio;
2580
2581 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
2582 if (prio > TIPC_MAX_LINK_PRI)
2583 return -EINVAL;
2584 }
2585
2586 if (props[TIPC_NLA_PROP_TOL]) {
2587 u32 tol;
2588
2589 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
2590 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
2591 return -EINVAL;
2592 }
2593
2594 if (props[TIPC_NLA_PROP_WIN]) {
2595 u32 max_win;
2596
2597 max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
2598 if (max_win < TIPC_DEF_LINK_WIN || max_win > TIPC_MAX_LINK_WIN)
2599 return -EINVAL;
2600 }
2601
2602 return 0;
2603 }
2604
__tipc_nl_add_stats(struct sk_buff * skb,struct tipc_stats * s)2605 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
2606 {
2607 int i;
2608 struct nlattr *stats;
2609
2610 struct nla_map {
2611 u32 key;
2612 u32 val;
2613 };
2614
2615 struct nla_map map[] = {
2616 {TIPC_NLA_STATS_RX_INFO, 0},
2617 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
2618 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
2619 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
2620 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
2621 {TIPC_NLA_STATS_TX_INFO, 0},
2622 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
2623 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
2624 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
2625 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
2626 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
2627 s->msg_length_counts : 1},
2628 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
2629 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
2630 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
2631 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
2632 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
2633 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
2634 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
2635 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
2636 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
2637 {TIPC_NLA_STATS_RX_STATES, s->recv_states},
2638 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
2639 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
2640 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
2641 {TIPC_NLA_STATS_TX_STATES, s->sent_states},
2642 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
2643 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
2644 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
2645 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
2646 {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
2647 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
2648 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
2649 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
2650 (s->accu_queue_sz / s->queue_sz_counts) : 0}
2651 };
2652
2653 stats = nla_nest_start_noflag(skb, TIPC_NLA_LINK_STATS);
2654 if (!stats)
2655 return -EMSGSIZE;
2656
2657 for (i = 0; i < ARRAY_SIZE(map); i++)
2658 if (nla_put_u32(skb, map[i].key, map[i].val))
2659 goto msg_full;
2660
2661 nla_nest_end(skb, stats);
2662
2663 return 0;
2664 msg_full:
2665 nla_nest_cancel(skb, stats);
2666
2667 return -EMSGSIZE;
2668 }
2669
2670 /* Caller should hold appropriate locks to protect the link */
__tipc_nl_add_link(struct net * net,struct tipc_nl_msg * msg,struct tipc_link * link,int nlflags)2671 int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
2672 struct tipc_link *link, int nlflags)
2673 {
2674 u32 self = tipc_own_addr(net);
2675 struct nlattr *attrs;
2676 struct nlattr *prop;
2677 void *hdr;
2678 int err;
2679
2680 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2681 nlflags, TIPC_NL_LINK_GET);
2682 if (!hdr)
2683 return -EMSGSIZE;
2684
2685 attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK);
2686 if (!attrs)
2687 goto msg_full;
2688
2689 if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
2690 goto attr_msg_full;
2691 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST, tipc_cluster_mask(self)))
2692 goto attr_msg_full;
2693 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
2694 goto attr_msg_full;
2695 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->stats.recv_pkts))
2696 goto attr_msg_full;
2697 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->stats.sent_pkts))
2698 goto attr_msg_full;
2699
2700 if (tipc_link_is_up(link))
2701 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2702 goto attr_msg_full;
2703 if (link->active)
2704 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
2705 goto attr_msg_full;
2706
2707 prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK_PROP);
2708 if (!prop)
2709 goto attr_msg_full;
2710 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2711 goto prop_msg_full;
2712 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
2713 goto prop_msg_full;
2714 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
2715 link->window))
2716 goto prop_msg_full;
2717 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2718 goto prop_msg_full;
2719 nla_nest_end(msg->skb, prop);
2720
2721 err = __tipc_nl_add_stats(msg->skb, &link->stats);
2722 if (err)
2723 goto attr_msg_full;
2724
2725 nla_nest_end(msg->skb, attrs);
2726 genlmsg_end(msg->skb, hdr);
2727
2728 return 0;
2729
2730 prop_msg_full:
2731 nla_nest_cancel(msg->skb, prop);
2732 attr_msg_full:
2733 nla_nest_cancel(msg->skb, attrs);
2734 msg_full:
2735 genlmsg_cancel(msg->skb, hdr);
2736
2737 return -EMSGSIZE;
2738 }
2739
__tipc_nl_add_bc_link_stat(struct sk_buff * skb,struct tipc_stats * stats)2740 static int __tipc_nl_add_bc_link_stat(struct sk_buff *skb,
2741 struct tipc_stats *stats)
2742 {
2743 int i;
2744 struct nlattr *nest;
2745
2746 struct nla_map {
2747 __u32 key;
2748 __u32 val;
2749 };
2750
2751 struct nla_map map[] = {
2752 {TIPC_NLA_STATS_RX_INFO, stats->recv_pkts},
2753 {TIPC_NLA_STATS_RX_FRAGMENTS, stats->recv_fragments},
2754 {TIPC_NLA_STATS_RX_FRAGMENTED, stats->recv_fragmented},
2755 {TIPC_NLA_STATS_RX_BUNDLES, stats->recv_bundles},
2756 {TIPC_NLA_STATS_RX_BUNDLED, stats->recv_bundled},
2757 {TIPC_NLA_STATS_TX_INFO, stats->sent_pkts},
2758 {TIPC_NLA_STATS_TX_FRAGMENTS, stats->sent_fragments},
2759 {TIPC_NLA_STATS_TX_FRAGMENTED, stats->sent_fragmented},
2760 {TIPC_NLA_STATS_TX_BUNDLES, stats->sent_bundles},
2761 {TIPC_NLA_STATS_TX_BUNDLED, stats->sent_bundled},
2762 {TIPC_NLA_STATS_RX_NACKS, stats->recv_nacks},
2763 {TIPC_NLA_STATS_RX_DEFERRED, stats->deferred_recv},
2764 {TIPC_NLA_STATS_TX_NACKS, stats->sent_nacks},
2765 {TIPC_NLA_STATS_TX_ACKS, stats->sent_acks},
2766 {TIPC_NLA_STATS_RETRANSMITTED, stats->retransmitted},
2767 {TIPC_NLA_STATS_DUPLICATES, stats->duplicates},
2768 {TIPC_NLA_STATS_LINK_CONGS, stats->link_congs},
2769 {TIPC_NLA_STATS_MAX_QUEUE, stats->max_queue_sz},
2770 {TIPC_NLA_STATS_AVG_QUEUE, stats->queue_sz_counts ?
2771 (stats->accu_queue_sz / stats->queue_sz_counts) : 0}
2772 };
2773
2774 nest = nla_nest_start_noflag(skb, TIPC_NLA_LINK_STATS);
2775 if (!nest)
2776 return -EMSGSIZE;
2777
2778 for (i = 0; i < ARRAY_SIZE(map); i++)
2779 if (nla_put_u32(skb, map[i].key, map[i].val))
2780 goto msg_full;
2781
2782 nla_nest_end(skb, nest);
2783
2784 return 0;
2785 msg_full:
2786 nla_nest_cancel(skb, nest);
2787
2788 return -EMSGSIZE;
2789 }
2790
tipc_nl_add_bc_link(struct net * net,struct tipc_nl_msg * msg,struct tipc_link * bcl)2791 int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg,
2792 struct tipc_link *bcl)
2793 {
2794 int err;
2795 void *hdr;
2796 struct nlattr *attrs;
2797 struct nlattr *prop;
2798 u32 bc_mode = tipc_bcast_get_mode(net);
2799 u32 bc_ratio = tipc_bcast_get_broadcast_ratio(net);
2800
2801 if (!bcl)
2802 return 0;
2803
2804 tipc_bcast_lock(net);
2805
2806 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2807 NLM_F_MULTI, TIPC_NL_LINK_GET);
2808 if (!hdr) {
2809 tipc_bcast_unlock(net);
2810 return -EMSGSIZE;
2811 }
2812
2813 attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK);
2814 if (!attrs)
2815 goto msg_full;
2816
2817 /* The broadcast link is always up */
2818 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2819 goto attr_msg_full;
2820
2821 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_BROADCAST))
2822 goto attr_msg_full;
2823 if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, bcl->name))
2824 goto attr_msg_full;
2825 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, 0))
2826 goto attr_msg_full;
2827 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, 0))
2828 goto attr_msg_full;
2829
2830 prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK_PROP);
2831 if (!prop)
2832 goto attr_msg_full;
2833 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bcl->max_win))
2834 goto prop_msg_full;
2835 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_BROADCAST, bc_mode))
2836 goto prop_msg_full;
2837 if (bc_mode & BCLINK_MODE_SEL)
2838 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_BROADCAST_RATIO,
2839 bc_ratio))
2840 goto prop_msg_full;
2841 nla_nest_end(msg->skb, prop);
2842
2843 err = __tipc_nl_add_bc_link_stat(msg->skb, &bcl->stats);
2844 if (err)
2845 goto attr_msg_full;
2846
2847 tipc_bcast_unlock(net);
2848 nla_nest_end(msg->skb, attrs);
2849 genlmsg_end(msg->skb, hdr);
2850
2851 return 0;
2852
2853 prop_msg_full:
2854 nla_nest_cancel(msg->skb, prop);
2855 attr_msg_full:
2856 nla_nest_cancel(msg->skb, attrs);
2857 msg_full:
2858 tipc_bcast_unlock(net);
2859 genlmsg_cancel(msg->skb, hdr);
2860
2861 return -EMSGSIZE;
2862 }
2863
tipc_link_set_tolerance(struct tipc_link * l,u32 tol,struct sk_buff_head * xmitq)2864 void tipc_link_set_tolerance(struct tipc_link *l, u32 tol,
2865 struct sk_buff_head *xmitq)
2866 {
2867 l->tolerance = tol;
2868 if (l->bc_rcvlink)
2869 l->bc_rcvlink->tolerance = tol;
2870 if (tipc_link_is_up(l))
2871 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, tol, 0, xmitq);
2872 }
2873
tipc_link_set_prio(struct tipc_link * l,u32 prio,struct sk_buff_head * xmitq)2874 void tipc_link_set_prio(struct tipc_link *l, u32 prio,
2875 struct sk_buff_head *xmitq)
2876 {
2877 l->priority = prio;
2878 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, prio, xmitq);
2879 }
2880
tipc_link_set_abort_limit(struct tipc_link * l,u32 limit)2881 void tipc_link_set_abort_limit(struct tipc_link *l, u32 limit)
2882 {
2883 l->abort_limit = limit;
2884 }
2885
2886 /**
2887 * tipc_link_dump - dump TIPC link data
2888 * @l: tipc link to be dumped
2889 * @dqueues: bitmask to decide if any link queue to be dumped?
2890 * - TIPC_DUMP_NONE: don't dump link queues
2891 * - TIPC_DUMP_TRANSMQ: dump link transmq queue
2892 * - TIPC_DUMP_BACKLOGQ: dump link backlog queue
2893 * - TIPC_DUMP_DEFERDQ: dump link deferd queue
2894 * - TIPC_DUMP_INPUTQ: dump link input queue
2895 * - TIPC_DUMP_WAKEUP: dump link wakeup queue
2896 * - TIPC_DUMP_ALL: dump all the link queues above
2897 * @buf: returned buffer of dump data in format
2898 */
tipc_link_dump(struct tipc_link * l,u16 dqueues,char * buf)2899 int tipc_link_dump(struct tipc_link *l, u16 dqueues, char *buf)
2900 {
2901 int i = 0;
2902 size_t sz = (dqueues) ? LINK_LMAX : LINK_LMIN;
2903 struct sk_buff_head *list;
2904 struct sk_buff *hskb, *tskb;
2905 u32 len;
2906
2907 if (!l) {
2908 i += scnprintf(buf, sz, "link data: (null)\n");
2909 return i;
2910 }
2911
2912 i += scnprintf(buf, sz, "link data: %x", l->addr);
2913 i += scnprintf(buf + i, sz - i, " %x", l->state);
2914 i += scnprintf(buf + i, sz - i, " %u", l->in_session);
2915 i += scnprintf(buf + i, sz - i, " %u", l->session);
2916 i += scnprintf(buf + i, sz - i, " %u", l->peer_session);
2917 i += scnprintf(buf + i, sz - i, " %u", l->snd_nxt);
2918 i += scnprintf(buf + i, sz - i, " %u", l->rcv_nxt);
2919 i += scnprintf(buf + i, sz - i, " %u", l->snd_nxt_state);
2920 i += scnprintf(buf + i, sz - i, " %u", l->rcv_nxt_state);
2921 i += scnprintf(buf + i, sz - i, " %x", l->peer_caps);
2922 i += scnprintf(buf + i, sz - i, " %u", l->silent_intv_cnt);
2923 i += scnprintf(buf + i, sz - i, " %u", l->rst_cnt);
2924 i += scnprintf(buf + i, sz - i, " %u", 0);
2925 i += scnprintf(buf + i, sz - i, " %u", 0);
2926 i += scnprintf(buf + i, sz - i, " %u", l->acked);
2927
2928 list = &l->transmq;
2929 len = skb_queue_len(list);
2930 hskb = skb_peek(list);
2931 tskb = skb_peek_tail(list);
2932 i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
2933 (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2934 (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2935
2936 list = &l->deferdq;
2937 len = skb_queue_len(list);
2938 hskb = skb_peek(list);
2939 tskb = skb_peek_tail(list);
2940 i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
2941 (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2942 (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2943
2944 list = &l->backlogq;
2945 len = skb_queue_len(list);
2946 hskb = skb_peek(list);
2947 tskb = skb_peek_tail(list);
2948 i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
2949 (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2950 (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2951
2952 list = l->inputq;
2953 len = skb_queue_len(list);
2954 hskb = skb_peek(list);
2955 tskb = skb_peek_tail(list);
2956 i += scnprintf(buf + i, sz - i, " | %u %u %u\n", len,
2957 (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2958 (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2959
2960 if (dqueues & TIPC_DUMP_TRANSMQ) {
2961 i += scnprintf(buf + i, sz - i, "transmq: ");
2962 i += tipc_list_dump(&l->transmq, false, buf + i);
2963 }
2964 if (dqueues & TIPC_DUMP_BACKLOGQ) {
2965 i += scnprintf(buf + i, sz - i,
2966 "backlogq: <%u %u %u %u %u>, ",
2967 l->backlog[TIPC_LOW_IMPORTANCE].len,
2968 l->backlog[TIPC_MEDIUM_IMPORTANCE].len,
2969 l->backlog[TIPC_HIGH_IMPORTANCE].len,
2970 l->backlog[TIPC_CRITICAL_IMPORTANCE].len,
2971 l->backlog[TIPC_SYSTEM_IMPORTANCE].len);
2972 i += tipc_list_dump(&l->backlogq, false, buf + i);
2973 }
2974 if (dqueues & TIPC_DUMP_DEFERDQ) {
2975 i += scnprintf(buf + i, sz - i, "deferdq: ");
2976 i += tipc_list_dump(&l->deferdq, false, buf + i);
2977 }
2978 if (dqueues & TIPC_DUMP_INPUTQ) {
2979 i += scnprintf(buf + i, sz - i, "inputq: ");
2980 i += tipc_list_dump(l->inputq, false, buf + i);
2981 }
2982 if (dqueues & TIPC_DUMP_WAKEUP) {
2983 i += scnprintf(buf + i, sz - i, "wakeup: ");
2984 i += tipc_list_dump(&l->wakeupq, false, buf + i);
2985 }
2986
2987 return i;
2988 }
2989