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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[mirror_ubuntu-jammy-kernel.git] / net / 802 / garp.c
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_LICENSE("GPL");
25
26 static const struct garp_state_trans {
27 u8 state;
28 u8 action;
29 } garp_applicant_state_table[GARP_APPLICANT_MAX + 1][GARP_EVENT_MAX + 1] = {
30 [GARP_APPLICANT_VA] = {
31 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_AA,
32 .action = GARP_ACTION_S_JOIN_IN },
33 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_AA },
34 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VA },
35 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VA },
36 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VA },
37 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
38 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
39 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_LA },
40 },
41 [GARP_APPLICANT_AA] = {
42 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_QA,
43 .action = GARP_ACTION_S_JOIN_IN },
44 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QA },
45 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VA },
46 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VA },
47 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VA },
48 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
49 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
50 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_LA },
51 },
52 [GARP_APPLICANT_QA] = {
53 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID },
54 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QA },
55 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VA },
56 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VA },
57 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VP },
58 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
59 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
60 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_LA },
61 },
62 [GARP_APPLICANT_LA] = {
63 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_VO,
64 .action = GARP_ACTION_S_LEAVE_EMPTY },
65 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_LA },
66 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VO },
67 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_LA },
68 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_LA },
69 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VO },
70 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_VA },
71 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_INVALID },
72 },
73 [GARP_APPLICANT_VP] = {
74 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_AA,
75 .action = GARP_ACTION_S_JOIN_IN },
76 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_AP },
77 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VP },
78 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VP },
79 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VP },
80 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
81 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
82 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_VO },
83 },
84 [GARP_APPLICANT_AP] = {
85 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_QA,
86 .action = GARP_ACTION_S_JOIN_IN },
87 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QP },
88 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VP },
89 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VP },
90 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VP },
91 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
92 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
93 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_AO },
94 },
95 [GARP_APPLICANT_QP] = {
96 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID },
97 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QP },
98 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VP },
99 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VP },
100 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VP },
101 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
102 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
103 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_QO },
104 },
105 [GARP_APPLICANT_VO] = {
106 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID },
107 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_AO },
108 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VO },
109 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VO },
110 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VO },
111 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VO },
112 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_VP },
113 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_INVALID },
114 },
115 [GARP_APPLICANT_AO] = {
116 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID },
117 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QO },
118 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VO },
119 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VO },
120 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VO },
121 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VO },
122 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_AP },
123 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_INVALID },
124 },
125 [GARP_APPLICANT_QO] = {
126 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID },
127 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QO },
128 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VO },
129 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VO },
130 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VO },
131 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VO },
132 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_QP },
133 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_INVALID },
134 },
135 };
136
137 static int garp_attr_cmp(const struct garp_attr *attr,
138 const void *data, u8 len, u8 type)
139 {
140 if (attr->type != type)
141 return attr->type - type;
142 if (attr->dlen != len)
143 return attr->dlen - len;
144 return memcmp(attr->data, data, len);
145 }
146
147 static struct garp_attr *garp_attr_lookup(const struct garp_applicant *app,
148 const void *data, u8 len, u8 type)
149 {
150 struct rb_node *parent = app->gid.rb_node;
151 struct garp_attr *attr;
152 int d;
153
154 while (parent) {
155 attr = rb_entry(parent, struct garp_attr, node);
156 d = garp_attr_cmp(attr, data, len, type);
157 if (d > 0)
158 parent = parent->rb_left;
159 else if (d < 0)
160 parent = parent->rb_right;
161 else
162 return attr;
163 }
164 return NULL;
165 }
166
167 static struct garp_attr *garp_attr_create(struct garp_applicant *app,
168 const void *data, u8 len, u8 type)
169 {
170 struct rb_node *parent = NULL, **p = &app->gid.rb_node;
171 struct garp_attr *attr;
172 int d;
173
174 while (*p) {
175 parent = *p;
176 attr = rb_entry(parent, struct garp_attr, node);
177 d = garp_attr_cmp(attr, data, len, type);
178 if (d > 0)
179 p = &parent->rb_left;
180 else if (d < 0)
181 p = &parent->rb_right;
182 else {
183 /* The attribute already exists; re-use it. */
184 return attr;
185 }
186 }
187 attr = kmalloc(sizeof(*attr) + len, GFP_ATOMIC);
188 if (!attr)
189 return attr;
190 attr->state = GARP_APPLICANT_VO;
191 attr->type = type;
192 attr->dlen = len;
193 memcpy(attr->data, data, len);
194
195 rb_link_node(&attr->node, parent, p);
196 rb_insert_color(&attr->node, &app->gid);
197 return attr;
198 }
199
200 static void garp_attr_destroy(struct garp_applicant *app, struct garp_attr *attr)
201 {
202 rb_erase(&attr->node, &app->gid);
203 kfree(attr);
204 }
205
206 static void garp_attr_destroy_all(struct garp_applicant *app)
207 {
208 struct rb_node *node, *next;
209 struct garp_attr *attr;
210
211 for (node = rb_first(&app->gid);
212 next = node ? rb_next(node) : NULL, node != NULL;
213 node = next) {
214 attr = rb_entry(node, struct garp_attr, node);
215 garp_attr_destroy(app, attr);
216 }
217 }
218
219 static int garp_pdu_init(struct garp_applicant *app)
220 {
221 struct sk_buff *skb;
222 struct garp_pdu_hdr *gp;
223
224 #define LLC_RESERVE sizeof(struct llc_pdu_un)
225 skb = alloc_skb(app->dev->mtu + LL_RESERVED_SPACE(app->dev),
226 GFP_ATOMIC);
227 if (!skb)
228 return -ENOMEM;
229
230 skb->dev = app->dev;
231 skb->protocol = htons(ETH_P_802_2);
232 skb_reserve(skb, LL_RESERVED_SPACE(app->dev) + LLC_RESERVE);
233
234 gp = __skb_put(skb, sizeof(*gp));
235 put_unaligned(htons(GARP_PROTOCOL_ID), &gp->protocol);
236
237 app->pdu = skb;
238 return 0;
239 }
240
241 static int garp_pdu_append_end_mark(struct garp_applicant *app)
242 {
243 if (skb_tailroom(app->pdu) < sizeof(u8))
244 return -1;
245 __skb_put_u8(app->pdu, GARP_END_MARK);
246 return 0;
247 }
248
249 static void garp_pdu_queue(struct garp_applicant *app)
250 {
251 if (!app->pdu)
252 return;
253
254 garp_pdu_append_end_mark(app);
255 garp_pdu_append_end_mark(app);
256
257 llc_pdu_header_init(app->pdu, LLC_PDU_TYPE_U, LLC_SAP_BSPAN,
258 LLC_SAP_BSPAN, LLC_PDU_CMD);
259 llc_pdu_init_as_ui_cmd(app->pdu);
260 llc_mac_hdr_init(app->pdu, app->dev->dev_addr,
261 app->app->proto.group_address);
262
263 skb_queue_tail(&app->queue, app->pdu);
264 app->pdu = NULL;
265 }
266
267 static void garp_queue_xmit(struct garp_applicant *app)
268 {
269 struct sk_buff *skb;
270
271 while ((skb = skb_dequeue(&app->queue)))
272 dev_queue_xmit(skb);
273 }
274
275 static int garp_pdu_append_msg(struct garp_applicant *app, u8 attrtype)
276 {
277 struct garp_msg_hdr *gm;
278
279 if (skb_tailroom(app->pdu) < sizeof(*gm))
280 return -1;
281 gm = __skb_put(app->pdu, sizeof(*gm));
282 gm->attrtype = attrtype;
283 garp_cb(app->pdu)->cur_type = attrtype;
284 return 0;
285 }
286
287 static int garp_pdu_append_attr(struct garp_applicant *app,
288 const struct garp_attr *attr,
289 enum garp_attr_event event)
290 {
291 struct garp_attr_hdr *ga;
292 unsigned int len;
293 int err;
294 again:
295 if (!app->pdu) {
296 err = garp_pdu_init(app);
297 if (err < 0)
298 return err;
299 }
300
301 if (garp_cb(app->pdu)->cur_type != attr->type) {
302 if (garp_cb(app->pdu)->cur_type &&
303 garp_pdu_append_end_mark(app) < 0)
304 goto queue;
305 if (garp_pdu_append_msg(app, attr->type) < 0)
306 goto queue;
307 }
308
309 len = sizeof(*ga) + attr->dlen;
310 if (skb_tailroom(app->pdu) < len)
311 goto queue;
312 ga = __skb_put(app->pdu, len);
313 ga->len = len;
314 ga->event = event;
315 memcpy(ga->data, attr->data, attr->dlen);
316 return 0;
317
318 queue:
319 garp_pdu_queue(app);
320 goto again;
321 }
322
323 static void garp_attr_event(struct garp_applicant *app,
324 struct garp_attr *attr, enum garp_event event)
325 {
326 enum garp_applicant_state state;
327
328 state = garp_applicant_state_table[attr->state][event].state;
329 if (state == GARP_APPLICANT_INVALID)
330 return;
331
332 switch (garp_applicant_state_table[attr->state][event].action) {
333 case GARP_ACTION_NONE:
334 break;
335 case GARP_ACTION_S_JOIN_IN:
336 /* When appending the attribute fails, don't update state in
337 * order to retry on next TRANSMIT_PDU event. */
338 if (garp_pdu_append_attr(app, attr, GARP_JOIN_IN) < 0)
339 return;
340 break;
341 case GARP_ACTION_S_LEAVE_EMPTY:
342 garp_pdu_append_attr(app, attr, GARP_LEAVE_EMPTY);
343 /* As a pure applicant, sending a leave message implies that
344 * the attribute was unregistered and can be destroyed. */
345 garp_attr_destroy(app, attr);
346 return;
347 default:
348 WARN_ON(1);
349 }
350
351 attr->state = state;
352 }
353
354 int garp_request_join(const struct net_device *dev,
355 const struct garp_application *appl,
356 const void *data, u8 len, u8 type)
357 {
358 struct garp_port *port = rtnl_dereference(dev->garp_port);
359 struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]);
360 struct garp_attr *attr;
361
362 spin_lock_bh(&app->lock);
363 attr = garp_attr_create(app, data, len, type);
364 if (!attr) {
365 spin_unlock_bh(&app->lock);
366 return -ENOMEM;
367 }
368 garp_attr_event(app, attr, GARP_EVENT_REQ_JOIN);
369 spin_unlock_bh(&app->lock);
370 return 0;
371 }
372 EXPORT_SYMBOL_GPL(garp_request_join);
373
374 void garp_request_leave(const struct net_device *dev,
375 const struct garp_application *appl,
376 const void *data, u8 len, u8 type)
377 {
378 struct garp_port *port = rtnl_dereference(dev->garp_port);
379 struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]);
380 struct garp_attr *attr;
381
382 spin_lock_bh(&app->lock);
383 attr = garp_attr_lookup(app, data, len, type);
384 if (!attr) {
385 spin_unlock_bh(&app->lock);
386 return;
387 }
388 garp_attr_event(app, attr, GARP_EVENT_REQ_LEAVE);
389 spin_unlock_bh(&app->lock);
390 }
391 EXPORT_SYMBOL_GPL(garp_request_leave);
392
393 static void garp_gid_event(struct garp_applicant *app, enum garp_event event)
394 {
395 struct rb_node *node, *next;
396 struct garp_attr *attr;
397
398 for (node = rb_first(&app->gid);
399 next = node ? rb_next(node) : NULL, node != NULL;
400 node = next) {
401 attr = rb_entry(node, struct garp_attr, node);
402 garp_attr_event(app, attr, event);
403 }
404 }
405
406 static void garp_join_timer_arm(struct garp_applicant *app)
407 {
408 unsigned long delay;
409
410 delay = (u64)msecs_to_jiffies(garp_join_time) * prandom_u32() >> 32;
411 mod_timer(&app->join_timer, jiffies + delay);
412 }
413
414 static void garp_join_timer(struct timer_list *t)
415 {
416 struct garp_applicant *app = from_timer(app, t, join_timer);
417
418 spin_lock(&app->lock);
419 garp_gid_event(app, GARP_EVENT_TRANSMIT_PDU);
420 garp_pdu_queue(app);
421 spin_unlock(&app->lock);
422
423 garp_queue_xmit(app);
424 garp_join_timer_arm(app);
425 }
426
427 static int garp_pdu_parse_end_mark(struct sk_buff *skb)
428 {
429 if (!pskb_may_pull(skb, sizeof(u8)))
430 return -1;
431 if (*skb->data == GARP_END_MARK) {
432 skb_pull(skb, sizeof(u8));
433 return -1;
434 }
435 return 0;
436 }
437
438 static int garp_pdu_parse_attr(struct garp_applicant *app, struct sk_buff *skb,
439 u8 attrtype)
440 {
441 const struct garp_attr_hdr *ga;
442 struct garp_attr *attr;
443 enum garp_event event;
444 unsigned int dlen;
445
446 if (!pskb_may_pull(skb, sizeof(*ga)))
447 return -1;
448 ga = (struct garp_attr_hdr *)skb->data;
449 if (ga->len < sizeof(*ga))
450 return -1;
451
452 if (!pskb_may_pull(skb, ga->len))
453 return -1;
454 skb_pull(skb, ga->len);
455 dlen = sizeof(*ga) - ga->len;
456
457 if (attrtype > app->app->maxattr)
458 return 0;
459
460 switch (ga->event) {
461 case GARP_LEAVE_ALL:
462 if (dlen != 0)
463 return -1;
464 garp_gid_event(app, GARP_EVENT_R_LEAVE_EMPTY);
465 return 0;
466 case GARP_JOIN_EMPTY:
467 event = GARP_EVENT_R_JOIN_EMPTY;
468 break;
469 case GARP_JOIN_IN:
470 event = GARP_EVENT_R_JOIN_IN;
471 break;
472 case GARP_LEAVE_EMPTY:
473 event = GARP_EVENT_R_LEAVE_EMPTY;
474 break;
475 case GARP_EMPTY:
476 event = GARP_EVENT_R_EMPTY;
477 break;
478 default:
479 return 0;
480 }
481
482 if (dlen == 0)
483 return -1;
484 attr = garp_attr_lookup(app, ga->data, dlen, attrtype);
485 if (attr == NULL)
486 return 0;
487 garp_attr_event(app, attr, event);
488 return 0;
489 }
490
491 static int garp_pdu_parse_msg(struct garp_applicant *app, struct sk_buff *skb)
492 {
493 const struct garp_msg_hdr *gm;
494
495 if (!pskb_may_pull(skb, sizeof(*gm)))
496 return -1;
497 gm = (struct garp_msg_hdr *)skb->data;
498 if (gm->attrtype == 0)
499 return -1;
500 skb_pull(skb, sizeof(*gm));
501
502 while (skb->len > 0) {
503 if (garp_pdu_parse_attr(app, skb, gm->attrtype) < 0)
504 return -1;
505 if (garp_pdu_parse_end_mark(skb) < 0)
506 break;
507 }
508 return 0;
509 }
510
511 static void garp_pdu_rcv(const struct stp_proto *proto, struct sk_buff *skb,
512 struct net_device *dev)
513 {
514 struct garp_application *appl = proto->data;
515 struct garp_port *port;
516 struct garp_applicant *app;
517 const struct garp_pdu_hdr *gp;
518
519 port = rcu_dereference(dev->garp_port);
520 if (!port)
521 goto err;
522 app = rcu_dereference(port->applicants[appl->type]);
523 if (!app)
524 goto err;
525
526 if (!pskb_may_pull(skb, sizeof(*gp)))
527 goto err;
528 gp = (struct garp_pdu_hdr *)skb->data;
529 if (get_unaligned(&gp->protocol) != htons(GARP_PROTOCOL_ID))
530 goto err;
531 skb_pull(skb, sizeof(*gp));
532
533 spin_lock(&app->lock);
534 while (skb->len > 0) {
535 if (garp_pdu_parse_msg(app, skb) < 0)
536 break;
537 if (garp_pdu_parse_end_mark(skb) < 0)
538 break;
539 }
540 spin_unlock(&app->lock);
541 err:
542 kfree_skb(skb);
543 }
544
545 static int garp_init_port(struct net_device *dev)
546 {
547 struct garp_port *port;
548
549 port = kzalloc(sizeof(*port), GFP_KERNEL);
550 if (!port)
551 return -ENOMEM;
552 rcu_assign_pointer(dev->garp_port, port);
553 return 0;
554 }
555
556 static void garp_release_port(struct net_device *dev)
557 {
558 struct garp_port *port = rtnl_dereference(dev->garp_port);
559 unsigned int i;
560
561 for (i = 0; i <= GARP_APPLICATION_MAX; i++) {
562 if (rtnl_dereference(port->applicants[i]))
563 return;
564 }
565 RCU_INIT_POINTER(dev->garp_port, NULL);
566 kfree_rcu(port, rcu);
567 }
568
569 int garp_init_applicant(struct net_device *dev, struct garp_application *appl)
570 {
571 struct garp_applicant *app;
572 int err;
573
574 ASSERT_RTNL();
575
576 if (!rtnl_dereference(dev->garp_port)) {
577 err = garp_init_port(dev);
578 if (err < 0)
579 goto err1;
580 }
581
582 err = -ENOMEM;
583 app = kzalloc(sizeof(*app), GFP_KERNEL);
584 if (!app)
585 goto err2;
586
587 err = dev_mc_add(dev, appl->proto.group_address);
588 if (err < 0)
589 goto err3;
590
591 app->dev = dev;
592 app->app = appl;
593 app->gid = RB_ROOT;
594 spin_lock_init(&app->lock);
595 skb_queue_head_init(&app->queue);
596 rcu_assign_pointer(dev->garp_port->applicants[appl->type], app);
597 timer_setup(&app->join_timer, garp_join_timer, 0);
598 garp_join_timer_arm(app);
599 return 0;
600
601 err3:
602 kfree(app);
603 err2:
604 garp_release_port(dev);
605 err1:
606 return err;
607 }
608 EXPORT_SYMBOL_GPL(garp_init_applicant);
609
610 void garp_uninit_applicant(struct net_device *dev, struct garp_application *appl)
611 {
612 struct garp_port *port = rtnl_dereference(dev->garp_port);
613 struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]);
614
615 ASSERT_RTNL();
616
617 RCU_INIT_POINTER(port->applicants[appl->type], NULL);
618
619 /* Delete timer and generate a final TRANSMIT_PDU event to flush out
620 * all pending messages before the applicant is gone. */
621 del_timer_sync(&app->join_timer);
622
623 spin_lock_bh(&app->lock);
624 garp_gid_event(app, GARP_EVENT_TRANSMIT_PDU);
625 garp_attr_destroy_all(app);
626 garp_pdu_queue(app);
627 spin_unlock_bh(&app->lock);
628
629 garp_queue_xmit(app);
630
631 dev_mc_del(dev, appl->proto.group_address);
632 kfree_rcu(app, rcu);
633 garp_release_port(dev);
634 }
635 EXPORT_SYMBOL_GPL(garp_uninit_applicant);
636
637 int garp_register_application(struct garp_application *appl)
638 {
639 appl->proto.rcv = garp_pdu_rcv;
640 appl->proto.data = appl;
641 return stp_proto_register(&appl->proto);
642 }
643 EXPORT_SYMBOL_GPL(garp_register_application);
644
645 void garp_unregister_application(struct garp_application *appl)
646 {
647 stp_proto_unregister(&appl->proto);
648 }
649 EXPORT_SYMBOL_GPL(garp_unregister_application);
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