1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * IEEE 802.1D Generic Attribute Registration Protocol (GARP)
4 *
5 * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
6 */
7 #include <linux/kernel.h>
8 #include <linux/timer.h>
9 #include <linux/skbuff.h>
10 #include <linux/netdevice.h>
11 #include <linux/etherdevice.h>
12 #include <linux/rtnetlink.h>
13 #include <linux/llc.h>
14 #include <linux/slab.h>
15 #include <linux/module.h>
16 #include <net/llc.h>
17 #include <net/llc_pdu.h>
18 #include <net/garp.h>
19 #include <asm/unaligned.h>
20
21 static unsigned int garp_join_time __read_mostly = 200;
22 module_param(garp_join_time, uint, 0644);
23 MODULE_PARM_DESC(garp_join_time, "Join time in ms (default 200ms)");
24 MODULE_DESCRIPTION("IEEE 802.1D Generic Attribute Registration Protocol (GARP)");
25 MODULE_LICENSE("GPL");
26
27 static const struct garp_state_trans {
28 u8 state;
29 u8 action;
30 } garp_applicant_state_table[GARP_APPLICANT_MAX + 1][GARP_EVENT_MAX + 1] = {
31 [GARP_APPLICANT_VA] = {
32 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_AA,
33 .action = GARP_ACTION_S_JOIN_IN },
34 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_AA },
35 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VA },
36 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VA },
37 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VA },
38 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
39 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
40 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_LA },
41 },
42 [GARP_APPLICANT_AA] = {
43 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_QA,
44 .action = GARP_ACTION_S_JOIN_IN },
45 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QA },
46 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VA },
47 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VA },
48 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VA },
49 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
50 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
51 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_LA },
52 },
53 [GARP_APPLICANT_QA] = {
54 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID },
55 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QA },
56 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VA },
57 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VA },
58 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VP },
59 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
60 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
61 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_LA },
62 },
63 [GARP_APPLICANT_LA] = {
64 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_VO,
65 .action = GARP_ACTION_S_LEAVE_EMPTY },
66 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_LA },
67 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VO },
68 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_LA },
69 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_LA },
70 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VO },
71 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_VA },
72 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_INVALID },
73 },
74 [GARP_APPLICANT_VP] = {
75 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_AA,
76 .action = GARP_ACTION_S_JOIN_IN },
77 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_AP },
78 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VP },
79 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VP },
80 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VP },
81 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
82 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
83 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_VO },
84 },
85 [GARP_APPLICANT_AP] = {
86 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_QA,
87 .action = GARP_ACTION_S_JOIN_IN },
88 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QP },
89 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VP },
90 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VP },
91 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VP },
92 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
93 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
94 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_AO },
95 },
96 [GARP_APPLICANT_QP] = {
97 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID },
98 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QP },
99 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VP },
100 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VP },
101 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VP },
102 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
103 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
104 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_QO },
105 },
106 [GARP_APPLICANT_VO] = {
107 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID },
108 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_AO },
109 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VO },
110 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VO },
111 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VO },
112 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VO },
113 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_VP },
114 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_INVALID },
115 },
116 [GARP_APPLICANT_AO] = {
117 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID },
118 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QO },
119 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VO },
120 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VO },
121 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VO },
122 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VO },
123 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_AP },
124 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_INVALID },
125 },
126 [GARP_APPLICANT_QO] = {
127 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID },
128 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QO },
129 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VO },
130 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VO },
131 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VO },
132 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VO },
133 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_QP },
134 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_INVALID },
135 },
136 };
137
138 static int garp_attr_cmp(const struct garp_attr *attr,
139 const void *data, u8 len, u8 type)
140 {
141 if (attr->type != type)
142 return attr->type - type;
143 if (attr->dlen != len)
144 return attr->dlen - len;
145 return memcmp(attr->data, data, len);
146 }
147
148 static struct garp_attr *garp_attr_lookup(const struct garp_applicant *app,
149 const void *data, u8 len, u8 type)
150 {
151 struct rb_node *parent = app->gid.rb_node;
152 struct garp_attr *attr;
153 int d;
154
155 while (parent) {
156 attr = rb_entry(parent, struct garp_attr, node);
157 d = garp_attr_cmp(attr, data, len, type);
158 if (d > 0)
159 parent = parent->rb_left;
160 else if (d < 0)
161 parent = parent->rb_right;
162 else
163 return attr;
164 }
165 return NULL;
166 }
167
168 static struct garp_attr *garp_attr_create(struct garp_applicant *app,
169 const void *data, u8 len, u8 type)
170 {
171 struct rb_node *parent = NULL, **p = &app->gid.rb_node;
172 struct garp_attr *attr;
173 int d;
174
175 while (*p) {
176 parent = *p;
177 attr = rb_entry(parent, struct garp_attr, node);
178 d = garp_attr_cmp(attr, data, len, type);
179 if (d > 0)
180 p = &parent->rb_left;
181 else if (d < 0)
182 p = &parent->rb_right;
183 else {
184 /* The attribute already exists; re-use it. */
185 return attr;
186 }
187 }
188 attr = kmalloc(sizeof(*attr) + len, GFP_ATOMIC);
189 if (!attr)
190 return attr;
191 attr->state = GARP_APPLICANT_VO;
192 attr->type = type;
193 attr->dlen = len;
194 memcpy(attr->data, data, len);
195
196 rb_link_node(&attr->node, parent, p);
197 rb_insert_color(&attr->node, &app->gid);
198 return attr;
199 }
200
201 static void garp_attr_destroy(struct garp_applicant *app, struct garp_attr *attr)
202 {
203 rb_erase(&attr->node, &app->gid);
204 kfree(attr);
205 }
206
207 static void garp_attr_destroy_all(struct garp_applicant *app)
208 {
209 struct rb_node *node, *next;
210 struct garp_attr *attr;
211
212 for (node = rb_first(&app->gid);
213 next = node ? rb_next(node) : NULL, node != NULL;
214 node = next) {
215 attr = rb_entry(node, struct garp_attr, node);
216 garp_attr_destroy(app, attr);
217 }
218 }
219
220 static int garp_pdu_init(struct garp_applicant *app)
221 {
222 struct sk_buff *skb;
223 struct garp_pdu_hdr *gp;
224
225 #define LLC_RESERVE sizeof(struct llc_pdu_un)
226 skb = alloc_skb(app->dev->mtu + LL_RESERVED_SPACE(app->dev),
227 GFP_ATOMIC);
228 if (!skb)
229 return -ENOMEM;
230
231 skb->dev = app->dev;
232 skb->protocol = htons(ETH_P_802_2);
233 skb_reserve(skb, LL_RESERVED_SPACE(app->dev) + LLC_RESERVE);
234
235 gp = __skb_put(skb, sizeof(*gp));
236 put_unaligned(htons(GARP_PROTOCOL_ID), &gp->protocol);
237
238 app->pdu = skb;
239 return 0;
240 }
241
242 static int garp_pdu_append_end_mark(struct garp_applicant *app)
243 {
244 if (skb_tailroom(app->pdu) < sizeof(u8))
245 return -1;
246 __skb_put_u8(app->pdu, GARP_END_MARK);
247 return 0;
248 }
249
250 static void garp_pdu_queue(struct garp_applicant *app)
251 {
252 if (!app->pdu)
253 return;
254
255 garp_pdu_append_end_mark(app);
256 garp_pdu_append_end_mark(app);
257
258 llc_pdu_header_init(app->pdu, LLC_PDU_TYPE_U, LLC_SAP_BSPAN,
259 LLC_SAP_BSPAN, LLC_PDU_CMD);
260 llc_pdu_init_as_ui_cmd(app->pdu);
261 llc_mac_hdr_init(app->pdu, app->dev->dev_addr,
262 app->app->proto.group_address);
263
264 skb_queue_tail(&app->queue, app->pdu);
265 app->pdu = NULL;
266 }
267
268 static void garp_queue_xmit(struct garp_applicant *app)
269 {
270 struct sk_buff *skb;
271
272 while ((skb = skb_dequeue(&app->queue)))
273 dev_queue_xmit(skb);
274 }
275
276 static int garp_pdu_append_msg(struct garp_applicant *app, u8 attrtype)
277 {
278 struct garp_msg_hdr *gm;
279
280 if (skb_tailroom(app->pdu) < sizeof(*gm))
281 return -1;
282 gm = __skb_put(app->pdu, sizeof(*gm));
283 gm->attrtype = attrtype;
284 garp_cb(app->pdu)->cur_type = attrtype;
285 return 0;
286 }
287
288 static int garp_pdu_append_attr(struct garp_applicant *app,
289 const struct garp_attr *attr,
290 enum garp_attr_event event)
291 {
292 struct garp_attr_hdr *ga;
293 unsigned int len;
294 int err;
295 again:
296 if (!app->pdu) {
297 err = garp_pdu_init(app);
298 if (err < 0)
299 return err;
300 }
301
302 if (garp_cb(app->pdu)->cur_type != attr->type) {
303 if (garp_cb(app->pdu)->cur_type &&
304 garp_pdu_append_end_mark(app) < 0)
305 goto queue;
306 if (garp_pdu_append_msg(app, attr->type) < 0)
307 goto queue;
308 }
309
310 len = sizeof(*ga) + attr->dlen;
311 if (skb_tailroom(app->pdu) < len)
312 goto queue;
313 ga = __skb_put(app->pdu, len);
314 ga->len = len;
315 ga->event = event;
316 memcpy(ga->data, attr->data, attr->dlen);
317 return 0;
318
319 queue:
320 garp_pdu_queue(app);
321 goto again;
322 }
323
324 static void garp_attr_event(struct garp_applicant *app,
325 struct garp_attr *attr, enum garp_event event)
326 {
327 enum garp_applicant_state state;
328
329 state = garp_applicant_state_table[attr->state][event].state;
330 if (state == GARP_APPLICANT_INVALID)
331 return;
332
333 switch (garp_applicant_state_table[attr->state][event].action) {
334 case GARP_ACTION_NONE:
335 break;
336 case GARP_ACTION_S_JOIN_IN:
337 /* When appending the attribute fails, don't update state in
338 * order to retry on next TRANSMIT_PDU event. */
339 if (garp_pdu_append_attr(app, attr, GARP_JOIN_IN) < 0)
340 return;
341 break;
342 case GARP_ACTION_S_LEAVE_EMPTY:
343 garp_pdu_append_attr(app, attr, GARP_LEAVE_EMPTY);
344 /* As a pure applicant, sending a leave message implies that
345 * the attribute was unregistered and can be destroyed. */
346 garp_attr_destroy(app, attr);
347 return;
348 default:
349 WARN_ON(1);
350 }
351
352 attr->state = state;
353 }
354
355 int garp_request_join(const struct net_device *dev,
356 const struct garp_application *appl,
357 const void *data, u8 len, u8 type)
358 {
359 struct garp_port *port = rtnl_dereference(dev->garp_port);
360 struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]);
361 struct garp_attr *attr;
362
363 spin_lock_bh(&app->lock);
364 attr = garp_attr_create(app, data, len, type);
365 if (!attr) {
366 spin_unlock_bh(&app->lock);
367 return -ENOMEM;
368 }
369 garp_attr_event(app, attr, GARP_EVENT_REQ_JOIN);
370 spin_unlock_bh(&app->lock);
371 return 0;
372 }
373 EXPORT_SYMBOL_GPL(garp_request_join);
374
375 void garp_request_leave(const struct net_device *dev,
376 const struct garp_application *appl,
377 const void *data, u8 len, u8 type)
378 {
379 struct garp_port *port = rtnl_dereference(dev->garp_port);
380 struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]);
381 struct garp_attr *attr;
382
383 spin_lock_bh(&app->lock);
384 attr = garp_attr_lookup(app, data, len, type);
385 if (!attr) {
386 spin_unlock_bh(&app->lock);
387 return;
388 }
389 garp_attr_event(app, attr, GARP_EVENT_REQ_LEAVE);
390 spin_unlock_bh(&app->lock);
391 }
392 EXPORT_SYMBOL_GPL(garp_request_leave);
393
394 static void garp_gid_event(struct garp_applicant *app, enum garp_event event)
395 {
396 struct rb_node *node, *next;
397 struct garp_attr *attr;
398
399 for (node = rb_first(&app->gid);
400 next = node ? rb_next(node) : NULL, node != NULL;
401 node = next) {
402 attr = rb_entry(node, struct garp_attr, node);
403 garp_attr_event(app, attr, event);
404 }
405 }
406
407 static void garp_join_timer_arm(struct garp_applicant *app)
408 {
409 unsigned long delay;
410
411 delay = get_random_u32_below(msecs_to_jiffies(garp_join_time));
412 mod_timer(&app->join_timer, jiffies + delay);
413 }
414
415 static void garp_join_timer(struct timer_list *t)
416 {
417 struct garp_applicant *app = from_timer(app, t, join_timer);
418
419 spin_lock(&app->lock);
420 garp_gid_event(app, GARP_EVENT_TRANSMIT_PDU);
421 garp_pdu_queue(app);
422 spin_unlock(&app->lock);
423
424 garp_queue_xmit(app);
425 garp_join_timer_arm(app);
426 }
427
428 static int garp_pdu_parse_end_mark(struct sk_buff *skb)
429 {
430 if (!pskb_may_pull(skb, sizeof(u8)))
431 return -1;
432 if (*skb->data == GARP_END_MARK) {
433 skb_pull(skb, sizeof(u8));
434 return -1;
435 }
436 return 0;
437 }
438
439 static int garp_pdu_parse_attr(struct garp_applicant *app, struct sk_buff *skb,
440 u8 attrtype)
441 {
442 const struct garp_attr_hdr *ga;
443 struct garp_attr *attr;
444 enum garp_event event;
445 unsigned int dlen;
446
447 if (!pskb_may_pull(skb, sizeof(*ga)))
448 return -1;
449 ga = (struct garp_attr_hdr *)skb->data;
450 if (ga->len < sizeof(*ga))
451 return -1;
452
453 if (!pskb_may_pull(skb, ga->len))
454 return -1;
455 skb_pull(skb, ga->len);
456 dlen = sizeof(*ga) - ga->len;
457
458 if (attrtype > app->app->maxattr)
459 return 0;
460
461 switch (ga->event) {
462 case GARP_LEAVE_ALL:
463 if (dlen != 0)
464 return -1;
465 garp_gid_event(app, GARP_EVENT_R_LEAVE_EMPTY);
466 return 0;
467 case GARP_JOIN_EMPTY:
468 event = GARP_EVENT_R_JOIN_EMPTY;
469 break;
470 case GARP_JOIN_IN:
471 event = GARP_EVENT_R_JOIN_IN;
472 break;
473 case GARP_LEAVE_EMPTY:
474 event = GARP_EVENT_R_LEAVE_EMPTY;
475 break;
476 case GARP_EMPTY:
477 event = GARP_EVENT_R_EMPTY;
478 break;
479 default:
480 return 0;
481 }
482
483 if (dlen == 0)
484 return -1;
485 attr = garp_attr_lookup(app, ga->data, dlen, attrtype);
486 if (attr == NULL)
487 return 0;
488 garp_attr_event(app, attr, event);
489 return 0;
490 }
491
492 static int garp_pdu_parse_msg(struct garp_applicant *app, struct sk_buff *skb)
493 {
494 const struct garp_msg_hdr *gm;
495
496 if (!pskb_may_pull(skb, sizeof(*gm)))
497 return -1;
498 gm = (struct garp_msg_hdr *)skb->data;
499 if (gm->attrtype == 0)
500 return -1;
501 skb_pull(skb, sizeof(*gm));
502
503 while (skb->len > 0) {
504 if (garp_pdu_parse_attr(app, skb, gm->attrtype) < 0)
505 return -1;
506 if (garp_pdu_parse_end_mark(skb) < 0)
507 break;
508 }
509 return 0;
510 }
511
512 static void garp_pdu_rcv(const struct stp_proto *proto, struct sk_buff *skb,
513 struct net_device *dev)
514 {
515 struct garp_application *appl = proto->data;
516 struct garp_port *port;
517 struct garp_applicant *app;
518 const struct garp_pdu_hdr *gp;
519
520 port = rcu_dereference(dev->garp_port);
521 if (!port)
522 goto err;
523 app = rcu_dereference(port->applicants[appl->type]);
524 if (!app)
525 goto err;
526
527 if (!pskb_may_pull(skb, sizeof(*gp)))
528 goto err;
529 gp = (struct garp_pdu_hdr *)skb->data;
530 if (get_unaligned(&gp->protocol) != htons(GARP_PROTOCOL_ID))
531 goto err;
532 skb_pull(skb, sizeof(*gp));
533
534 spin_lock(&app->lock);
535 while (skb->len > 0) {
536 if (garp_pdu_parse_msg(app, skb) < 0)
537 break;
538 if (garp_pdu_parse_end_mark(skb) < 0)
539 break;
540 }
541 spin_unlock(&app->lock);
542 err:
543 kfree_skb(skb);
544 }
545
546 static int garp_init_port(struct net_device *dev)
547 {
548 struct garp_port *port;
549
550 port = kzalloc(sizeof(*port), GFP_KERNEL);
551 if (!port)
552 return -ENOMEM;
553 rcu_assign_pointer(dev->garp_port, port);
554 return 0;
555 }
556
557 static void garp_release_port(struct net_device *dev)
558 {
559 struct garp_port *port = rtnl_dereference(dev->garp_port);
560 unsigned int i;
561
562 for (i = 0; i <= GARP_APPLICATION_MAX; i++) {
563 if (rtnl_dereference(port->applicants[i]))
564 return;
565 }
566 RCU_INIT_POINTER(dev->garp_port, NULL);
567 kfree_rcu(port, rcu);
568 }
569
570 int garp_init_applicant(struct net_device *dev, struct garp_application *appl)
571 {
572 struct garp_applicant *app;
573 int err;
574
575 ASSERT_RTNL();
576
577 if (!rtnl_dereference(dev->garp_port)) {
578 err = garp_init_port(dev);
579 if (err < 0)
580 goto err1;
581 }
582
583 err = -ENOMEM;
584 app = kzalloc(sizeof(*app), GFP_KERNEL);
585 if (!app)
586 goto err2;
587
588 err = dev_mc_add(dev, appl->proto.group_address);
589 if (err < 0)
590 goto err3;
591
592 app->dev = dev;
593 app->app = appl;
594 app->gid = RB_ROOT;
595 spin_lock_init(&app->lock);
596 skb_queue_head_init(&app->queue);
597 rcu_assign_pointer(dev->garp_port->applicants[appl->type], app);
598 timer_setup(&app->join_timer, garp_join_timer, 0);
599 garp_join_timer_arm(app);
600 return 0;
601
602 err3:
603 kfree(app);
604 err2:
605 garp_release_port(dev);
606 err1:
607 return err;
608 }
609 EXPORT_SYMBOL_GPL(garp_init_applicant);
610
611 void garp_uninit_applicant(struct net_device *dev, struct garp_application *appl)
612 {
613 struct garp_port *port = rtnl_dereference(dev->garp_port);
614 struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]);
615
616 ASSERT_RTNL();
617
618 RCU_INIT_POINTER(port->applicants[appl->type], NULL);
619
620 /* Delete timer and generate a final TRANSMIT_PDU event to flush out
621 * all pending messages before the applicant is gone. */
622 timer_shutdown_sync(&app->join_timer);
623
624 spin_lock_bh(&app->lock);
625 garp_gid_event(app, GARP_EVENT_TRANSMIT_PDU);
626 garp_attr_destroy_all(app);
627 garp_pdu_queue(app);
628 spin_unlock_bh(&app->lock);
629
630 garp_queue_xmit(app);
631
632 dev_mc_del(dev, appl->proto.group_address);
633 kfree_rcu(app, rcu);
634 garp_release_port(dev);
635 }
636 EXPORT_SYMBOL_GPL(garp_uninit_applicant);
637
638 int garp_register_application(struct garp_application *appl)
639 {
640 appl->proto.rcv = garp_pdu_rcv;
641 appl->proto.data = appl;
642 return stp_proto_register(&appl->proto);
643 }
644 EXPORT_SYMBOL_GPL(garp_register_application);
645
646 void garp_unregister_application(struct garp_application *appl)
647 {
648 stp_proto_unregister(&appl->proto);
649 }
650 EXPORT_SYMBOL_GPL(garp_unregister_application);
651
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