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tracing/snapshot: Resize spare buffer if size changed
[linux/fpc-iii.git] / net / 802 / garp.c
blob7f50d47470bd450566b448b0a3e6ad6fe6d0a000
1 /*
2 * IEEE 802.1D Generic Attribute Registration Protocol (GARP)
3 *
4 * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * version 2 as published by the Free Software Foundation.
9 */
10 #include <linux/kernel.h>
11 #include <linux/timer.h>
12 #include <linux/skbuff.h>
13 #include <linux/netdevice.h>
14 #include <linux/etherdevice.h>
15 #include <linux/rtnetlink.h>
16 #include <linux/llc.h>
17 #include <linux/slab.h>
18 #include <linux/module.h>
19 #include <net/llc.h>
20 #include <net/llc_pdu.h>
21 #include <net/garp.h>
22 #include <asm/unaligned.h>
23
24 static unsigned int garp_join_time __read_mostly = 200;
25 module_param(garp_join_time, uint, 0644);
26 MODULE_PARM_DESC(garp_join_time, "Join time in ms (default 200ms)");
27 MODULE_LICENSE("GPL");
28
29 static const struct garp_state_trans {
30 u8 state;
31 u8 action;
32 } garp_applicant_state_table[GARP_APPLICANT_MAX + 1][GARP_EVENT_MAX + 1] = {
33 [GARP_APPLICANT_VA] = {
34 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_AA,
35 .action = GARP_ACTION_S_JOIN_IN },
36 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_AA },
37 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VA },
38 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VA },
39 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VA },
40 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
41 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
42 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_LA },
43 },
44 [GARP_APPLICANT_AA] = {
45 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_QA,
46 .action = GARP_ACTION_S_JOIN_IN },
47 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QA },
48 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VA },
49 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VA },
50 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VA },
51 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
52 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
53 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_LA },
54 },
55 [GARP_APPLICANT_QA] = {
56 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID },
57 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QA },
58 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VA },
59 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VA },
60 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VP },
61 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
62 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
63 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_LA },
64 },
65 [GARP_APPLICANT_LA] = {
66 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_VO,
67 .action = GARP_ACTION_S_LEAVE_EMPTY },
68 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_LA },
69 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VO },
70 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_LA },
71 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_LA },
72 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VO },
73 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_VA },
74 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_INVALID },
75 },
76 [GARP_APPLICANT_VP] = {
77 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_AA,
78 .action = GARP_ACTION_S_JOIN_IN },
79 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_AP },
80 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VP },
81 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VP },
82 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VP },
83 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
84 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
85 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_VO },
86 },
87 [GARP_APPLICANT_AP] = {
88 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_QA,
89 .action = GARP_ACTION_S_JOIN_IN },
90 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QP },
91 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VP },
92 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VP },
93 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VP },
94 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
95 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
96 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_AO },
97 },
98 [GARP_APPLICANT_QP] = {
99 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID },
100 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QP },
101 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VP },
102 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VP },
103 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VP },
104 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
105 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
106 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_QO },
107 },
108 [GARP_APPLICANT_VO] = {
109 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID },
110 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_AO },
111 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VO },
112 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VO },
113 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VO },
114 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VO },
115 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_VP },
116 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_INVALID },
117 },
118 [GARP_APPLICANT_AO] = {
119 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID },
120 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QO },
121 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VO },
122 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VO },
123 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VO },
124 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VO },
125 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_AP },
126 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_INVALID },
127 },
128 [GARP_APPLICANT_QO] = {
129 [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID },
130 [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QO },
131 [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VO },
132 [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VO },
133 [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VO },
134 [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VO },
135 [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_QP },
136 [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_INVALID },
137 },
138 };
139
140 static int garp_attr_cmp(const struct garp_attr *attr,
141 const void *data, u8 len, u8 type)
142 {
143 if (attr->type != type)
144 return attr->type - type;
145 if (attr->dlen != len)
146 return attr->dlen - len;
147 return memcmp(attr->data, data, len);
148 }
149
150 static struct garp_attr *garp_attr_lookup(const struct garp_applicant *app,
151 const void *data, u8 len, u8 type)
152 {
153 struct rb_node *parent = app->gid.rb_node;
154 struct garp_attr *attr;
155 int d;
156
157 while (parent) {
158 attr = rb_entry(parent, struct garp_attr, node);
159 d = garp_attr_cmp(attr, data, len, type);
160 if (d > 0)
161 parent = parent->rb_left;
162 else if (d < 0)
163 parent = parent->rb_right;
164 else
165 return attr;
166 }
167 return NULL;
168 }
169
170 static struct garp_attr *garp_attr_create(struct garp_applicant *app,
171 const void *data, u8 len, u8 type)
172 {
173 struct rb_node *parent = NULL, **p = &app->gid.rb_node;
174 struct garp_attr *attr;
175 int d;
176
177 while (*p) {
178 parent = *p;
179 attr = rb_entry(parent, struct garp_attr, node);
180 d = garp_attr_cmp(attr, data, len, type);
181 if (d > 0)
182 p = &parent->rb_left;
183 else if (d < 0)
184 p = &parent->rb_right;
185 else {
186 /* The attribute already exists; re-use it. */
187 return attr;
188 }
189 }
190 attr = kmalloc(sizeof(*attr) + len, GFP_ATOMIC);
191 if (!attr)
192 return attr;
193 attr->state = GARP_APPLICANT_VO;
194 attr->type = type;
195 attr->dlen = len;
196 memcpy(attr->data, data, len);
197
198 rb_link_node(&attr->node, parent, p);
199 rb_insert_color(&attr->node, &app->gid);
200 return attr;
201 }
202
203 static void garp_attr_destroy(struct garp_applicant *app, struct garp_attr *attr)
204 {
205 rb_erase(&attr->node, &app->gid);
206 kfree(attr);
207 }
208
209 static int garp_pdu_init(struct garp_applicant *app)
210 {
211 struct sk_buff *skb;
212 struct garp_pdu_hdr *gp;
213
214 #define LLC_RESERVE sizeof(struct llc_pdu_un)
215 skb = alloc_skb(app->dev->mtu + LL_RESERVED_SPACE(app->dev),
216 GFP_ATOMIC);
217 if (!skb)
218 return -ENOMEM;
219
220 skb->dev = app->dev;
221 skb->protocol = htons(ETH_P_802_2);
222 skb_reserve(skb, LL_RESERVED_SPACE(app->dev) + LLC_RESERVE);
223
224 gp = __skb_put(skb, sizeof(*gp));
225 put_unaligned(htons(GARP_PROTOCOL_ID), &gp->protocol);
226
227 app->pdu = skb;
228 return 0;
229 }
230
231 static int garp_pdu_append_end_mark(struct garp_applicant *app)
232 {
233 if (skb_tailroom(app->pdu) < sizeof(u8))
234 return -1;
235 __skb_put_u8(app->pdu, GARP_END_MARK);
236 return 0;
237 }
238
239 static void garp_pdu_queue(struct garp_applicant *app)
240 {
241 if (!app->pdu)
242 return;
243
244 garp_pdu_append_end_mark(app);
245 garp_pdu_append_end_mark(app);
246
247 llc_pdu_header_init(app->pdu, LLC_PDU_TYPE_U, LLC_SAP_BSPAN,
248 LLC_SAP_BSPAN, LLC_PDU_CMD);
249 llc_pdu_init_as_ui_cmd(app->pdu);
250 llc_mac_hdr_init(app->pdu, app->dev->dev_addr,
251 app->app->proto.group_address);
252
253 skb_queue_tail(&app->queue, app->pdu);
254 app->pdu = NULL;
255 }
256
257 static void garp_queue_xmit(struct garp_applicant *app)
258 {
259 struct sk_buff *skb;
260
261 while ((skb = skb_dequeue(&app->queue)))
262 dev_queue_xmit(skb);
263 }
264
265 static int garp_pdu_append_msg(struct garp_applicant *app, u8 attrtype)
266 {
267 struct garp_msg_hdr *gm;
268
269 if (skb_tailroom(app->pdu) < sizeof(*gm))
270 return -1;
271 gm = __skb_put(app->pdu, sizeof(*gm));
272 gm->attrtype = attrtype;
273 garp_cb(app->pdu)->cur_type = attrtype;
274 return 0;
275 }
276
277 static int garp_pdu_append_attr(struct garp_applicant *app,
278 const struct garp_attr *attr,
279 enum garp_attr_event event)
280 {
281 struct garp_attr_hdr *ga;
282 unsigned int len;
283 int err;
284 again:
285 if (!app->pdu) {
286 err = garp_pdu_init(app);
287 if (err < 0)
288 return err;
289 }
290
291 if (garp_cb(app->pdu)->cur_type != attr->type) {
292 if (garp_cb(app->pdu)->cur_type &&
293 garp_pdu_append_end_mark(app) < 0)
294 goto queue;
295 if (garp_pdu_append_msg(app, attr->type) < 0)
296 goto queue;
297 }
298
299 len = sizeof(*ga) + attr->dlen;
300 if (skb_tailroom(app->pdu) < len)
301 goto queue;
302 ga = __skb_put(app->pdu, len);
303 ga->len = len;
304 ga->event = event;
305 memcpy(ga->data, attr->data, attr->dlen);
306 return 0;
307
308 queue:
309 garp_pdu_queue(app);
310 goto again;
311 }
312
313 static void garp_attr_event(struct garp_applicant *app,
314 struct garp_attr *attr, enum garp_event event)
315 {
316 enum garp_applicant_state state;
317
318 state = garp_applicant_state_table[attr->state][event].state;
319 if (state == GARP_APPLICANT_INVALID)
320 return;
321
322 switch (garp_applicant_state_table[attr->state][event].action) {
323 case GARP_ACTION_NONE:
324 break;
325 case GARP_ACTION_S_JOIN_IN:
326 /* When appending the attribute fails, don't update state in
327 * order to retry on next TRANSMIT_PDU event. */
328 if (garp_pdu_append_attr(app, attr, GARP_JOIN_IN) < 0)
329 return;
330 break;
331 case GARP_ACTION_S_LEAVE_EMPTY:
332 garp_pdu_append_attr(app, attr, GARP_LEAVE_EMPTY);
333 /* As a pure applicant, sending a leave message implies that
334 * the attribute was unregistered and can be destroyed. */
335 garp_attr_destroy(app, attr);
336 return;
337 default:
338 WARN_ON(1);
339 }
340
341 attr->state = state;
342 }
343
344 int garp_request_join(const struct net_device *dev,
345 const struct garp_application *appl,
346 const void *data, u8 len, u8 type)
347 {
348 struct garp_port *port = rtnl_dereference(dev->garp_port);
349 struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]);
350 struct garp_attr *attr;
351
352 spin_lock_bh(&app->lock);
353 attr = garp_attr_create(app, data, len, type);
354 if (!attr) {
355 spin_unlock_bh(&app->lock);
356 return -ENOMEM;
357 }
358 garp_attr_event(app, attr, GARP_EVENT_REQ_JOIN);
359 spin_unlock_bh(&app->lock);
360 return 0;
361 }
362 EXPORT_SYMBOL_GPL(garp_request_join);
363
364 void garp_request_leave(const struct net_device *dev,
365 const struct garp_application *appl,
366 const void *data, u8 len, u8 type)
367 {
368 struct garp_port *port = rtnl_dereference(dev->garp_port);
369 struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]);
370 struct garp_attr *attr;
371
372 spin_lock_bh(&app->lock);
373 attr = garp_attr_lookup(app, data, len, type);
374 if (!attr) {
375 spin_unlock_bh(&app->lock);
376 return;
377 }
378 garp_attr_event(app, attr, GARP_EVENT_REQ_LEAVE);
379 spin_unlock_bh(&app->lock);
380 }
381 EXPORT_SYMBOL_GPL(garp_request_leave);
382
383 static void garp_gid_event(struct garp_applicant *app, enum garp_event event)
384 {
385 struct rb_node *node, *next;
386 struct garp_attr *attr;
387
388 for (node = rb_first(&app->gid);
389 next = node ? rb_next(node) : NULL, node != NULL;
390 node = next) {
391 attr = rb_entry(node, struct garp_attr, node);
392 garp_attr_event(app, attr, event);
393 }
394 }
395
396 static void garp_join_timer_arm(struct garp_applicant *app)
397 {
398 unsigned long delay;
399
400 delay = (u64)msecs_to_jiffies(garp_join_time) * prandom_u32() >> 32;
401 mod_timer(&app->join_timer, jiffies + delay);
402 }
403
404 static void garp_join_timer(struct timer_list *t)
405 {
406 struct garp_applicant *app = from_timer(app, t, join_timer);
407
408 spin_lock(&app->lock);
409 garp_gid_event(app, GARP_EVENT_TRANSMIT_PDU);
410 garp_pdu_queue(app);
411 spin_unlock(&app->lock);
412
413 garp_queue_xmit(app);
414 garp_join_timer_arm(app);
415 }
416
417 static int garp_pdu_parse_end_mark(struct sk_buff *skb)
418 {
419 if (!pskb_may_pull(skb, sizeof(u8)))
420 return -1;
421 if (*skb->data == GARP_END_MARK) {
422 skb_pull(skb, sizeof(u8));
423 return -1;
424 }
425 return 0;
426 }
427
428 static int garp_pdu_parse_attr(struct garp_applicant *app, struct sk_buff *skb,
429 u8 attrtype)
430 {
431 const struct garp_attr_hdr *ga;
432 struct garp_attr *attr;
433 enum garp_event event;
434 unsigned int dlen;
435
436 if (!pskb_may_pull(skb, sizeof(*ga)))
437 return -1;
438 ga = (struct garp_attr_hdr *)skb->data;
439 if (ga->len < sizeof(*ga))
440 return -1;
441
442 if (!pskb_may_pull(skb, ga->len))
443 return -1;
444 skb_pull(skb, ga->len);
445 dlen = sizeof(*ga) - ga->len;
446
447 if (attrtype > app->app->maxattr)
448 return 0;
449
450 switch (ga->event) {
451 case GARP_LEAVE_ALL:
452 if (dlen != 0)
453 return -1;
454 garp_gid_event(app, GARP_EVENT_R_LEAVE_EMPTY);
455 return 0;
456 case GARP_JOIN_EMPTY:
457 event = GARP_EVENT_R_JOIN_EMPTY;
458 break;
459 case GARP_JOIN_IN:
460 event = GARP_EVENT_R_JOIN_IN;
461 break;
462 case GARP_LEAVE_EMPTY:
463 event = GARP_EVENT_R_LEAVE_EMPTY;
464 break;
465 case GARP_EMPTY:
466 event = GARP_EVENT_R_EMPTY;
467 break;
468 default:
469 return 0;
470 }
471
472 if (dlen == 0)
473 return -1;
474 attr = garp_attr_lookup(app, ga->data, dlen, attrtype);
475 if (attr == NULL)
476 return 0;
477 garp_attr_event(app, attr, event);
478 return 0;
479 }
480
481 static int garp_pdu_parse_msg(struct garp_applicant *app, struct sk_buff *skb)
482 {
483 const struct garp_msg_hdr *gm;
484
485 if (!pskb_may_pull(skb, sizeof(*gm)))
486 return -1;
487 gm = (struct garp_msg_hdr *)skb->data;
488 if (gm->attrtype == 0)
489 return -1;
490 skb_pull(skb, sizeof(*gm));
491
492 while (skb->len > 0) {
493 if (garp_pdu_parse_attr(app, skb, gm->attrtype) < 0)
494 return -1;
495 if (garp_pdu_parse_end_mark(skb) < 0)
496 break;
497 }
498 return 0;
499 }
500
501 static void garp_pdu_rcv(const struct stp_proto *proto, struct sk_buff *skb,
502 struct net_device *dev)
503 {
504 struct garp_application *appl = proto->data;
505 struct garp_port *port;
506 struct garp_applicant *app;
507 const struct garp_pdu_hdr *gp;
508
509 port = rcu_dereference(dev->garp_port);
510 if (!port)
511 goto err;
512 app = rcu_dereference(port->applicants[appl->type]);
513 if (!app)
514 goto err;
515
516 if (!pskb_may_pull(skb, sizeof(*gp)))
517 goto err;
518 gp = (struct garp_pdu_hdr *)skb->data;
519 if (get_unaligned(&gp->protocol) != htons(GARP_PROTOCOL_ID))
520 goto err;
521 skb_pull(skb, sizeof(*gp));
522
523 spin_lock(&app->lock);
524 while (skb->len > 0) {
525 if (garp_pdu_parse_msg(app, skb) < 0)
526 break;
527 if (garp_pdu_parse_end_mark(skb) < 0)
528 break;
529 }
530 spin_unlock(&app->lock);
531 err:
532 kfree_skb(skb);
533 }
534
535 static int garp_init_port(struct net_device *dev)
536 {
537 struct garp_port *port;
538
539 port = kzalloc(sizeof(*port), GFP_KERNEL);
540 if (!port)
541 return -ENOMEM;
542 rcu_assign_pointer(dev->garp_port, port);
543 return 0;
544 }
545
546 static void garp_release_port(struct net_device *dev)
547 {
548 struct garp_port *port = rtnl_dereference(dev->garp_port);
549 unsigned int i;
550
551 for (i = 0; i <= GARP_APPLICATION_MAX; i++) {
552 if (rtnl_dereference(port->applicants[i]))
553 return;
554 }
555 RCU_INIT_POINTER(dev->garp_port, NULL);
556 kfree_rcu(port, rcu);
557 }
558
559 int garp_init_applicant(struct net_device *dev, struct garp_application *appl)
560 {
561 struct garp_applicant *app;
562 int err;
563
564 ASSERT_RTNL();
565
566 if (!rtnl_dereference(dev->garp_port)) {
567 err = garp_init_port(dev);
568 if (err < 0)
569 goto err1;
570 }
571
572 err = -ENOMEM;
573 app = kzalloc(sizeof(*app), GFP_KERNEL);
574 if (!app)
575 goto err2;
576
577 err = dev_mc_add(dev, appl->proto.group_address);
578 if (err < 0)
579 goto err3;
580
581 app->dev = dev;
582 app->app = appl;
583 app->gid = RB_ROOT;
584 spin_lock_init(&app->lock);
585 skb_queue_head_init(&app->queue);
586 rcu_assign_pointer(dev->garp_port->applicants[appl->type], app);
587 timer_setup(&app->join_timer, garp_join_timer, 0);
588 garp_join_timer_arm(app);
589 return 0;
590
591 err3:
592 kfree(app);
593 err2:
594 garp_release_port(dev);
595 err1:
596 return err;
597 }
598 EXPORT_SYMBOL_GPL(garp_init_applicant);
599
600 void garp_uninit_applicant(struct net_device *dev, struct garp_application *appl)
601 {
602 struct garp_port *port = rtnl_dereference(dev->garp_port);
603 struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]);
604
605 ASSERT_RTNL();
606
607 RCU_INIT_POINTER(port->applicants[appl->type], NULL);
608
609 /* Delete timer and generate a final TRANSMIT_PDU event to flush out
610 * all pending messages before the applicant is gone. */
611 del_timer_sync(&app->join_timer);
612
613 spin_lock_bh(&app->lock);
614 garp_gid_event(app, GARP_EVENT_TRANSMIT_PDU);
615 garp_pdu_queue(app);
616 spin_unlock_bh(&app->lock);
617
618 garp_queue_xmit(app);
619
620 dev_mc_del(dev, appl->proto.group_address);
621 kfree_rcu(app, rcu);
622 garp_release_port(dev);
623 }
624 EXPORT_SYMBOL_GPL(garp_uninit_applicant);
625
626 int garp_register_application(struct garp_application *appl)
627 {
628 appl->proto.rcv = garp_pdu_rcv;
629 appl->proto.data = appl;
630 return stp_proto_register(&appl->proto);
631 }
632 EXPORT_SYMBOL_GPL(garp_register_application);
633
634 void garp_unregister_application(struct garp_application *appl)
635 {
636 stp_proto_unregister(&appl->proto);
637 }
638 EXPORT_SYMBOL_GPL(garp_unregister_application);
Linux with added FPC-III support