]> git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - net/802/garp.c
projects / mirror_ubuntu-jammy-kernel.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge branch 'linux-5.6' of git://github.com/skeggsb/linux into drm-fixes
[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 int garp_pdu_init(struct garp_applicant *app)
207 {
208 struct sk_buff *skb;
209 struct garp_pdu_hdr *gp;
210
211 #define LLC_RESERVE sizeof(struct llc_pdu_un)
212 skb = alloc_skb(app->dev->mtu + LL_RESERVED_SPACE(app->dev),
213 GFP_ATOMIC);
214 if (!skb)
215 return -ENOMEM;
216
217 skb->dev = app->dev;
218 skb->protocol = htons(ETH_P_802_2);
219 skb_reserve(skb, LL_RESERVED_SPACE(app->dev) + LLC_RESERVE);
220
221 gp = __skb_put(skb, sizeof(*gp));
222 put_unaligned(htons(GARP_PROTOCOL_ID), &gp->protocol);
223
224 app->pdu = skb;
225 return 0;
226 }
227
228 static int garp_pdu_append_end_mark(struct garp_applicant *app)
229 {
230 if (skb_tailroom(app->pdu) < sizeof(u8))
231 return -1;
232 __skb_put_u8(app->pdu, GARP_END_MARK);
233 return 0;
234 }
235
236 static void garp_pdu_queue(struct garp_applicant *app)
237 {
238 if (!app->pdu)
239 return;
240
241 garp_pdu_append_end_mark(app);
242 garp_pdu_append_end_mark(app);
243
244 llc_pdu_header_init(app->pdu, LLC_PDU_TYPE_U, LLC_SAP_BSPAN,
245 LLC_SAP_BSPAN, LLC_PDU_CMD);
246 llc_pdu_init_as_ui_cmd(app->pdu);
247 llc_mac_hdr_init(app->pdu, app->dev->dev_addr,
248 app->app->proto.group_address);
249
250 skb_queue_tail(&app->queue, app->pdu);
251 app->pdu = NULL;
252 }
253
254 static void garp_queue_xmit(struct garp_applicant *app)
255 {
256 struct sk_buff *skb;
257
258 while ((skb = skb_dequeue(&app->queue)))
259 dev_queue_xmit(skb);
260 }
261
262 static int garp_pdu_append_msg(struct garp_applicant *app, u8 attrtype)
263 {
264 struct garp_msg_hdr *gm;
265
266 if (skb_tailroom(app->pdu) < sizeof(*gm))
267 return -1;
268 gm = __skb_put(app->pdu, sizeof(*gm));
269 gm->attrtype = attrtype;
270 garp_cb(app->pdu)->cur_type = attrtype;
271 return 0;
272 }
273
274 static int garp_pdu_append_attr(struct garp_applicant *app,
275 const struct garp_attr *attr,
276 enum garp_attr_event event)
277 {
278 struct garp_attr_hdr *ga;
279 unsigned int len;
280 int err;
281 again:
282 if (!app->pdu) {
283 err = garp_pdu_init(app);
284 if (err < 0)
285 return err;
286 }
287
288 if (garp_cb(app->pdu)->cur_type != attr->type) {
289 if (garp_cb(app->pdu)->cur_type &&
290 garp_pdu_append_end_mark(app) < 0)
291 goto queue;
292 if (garp_pdu_append_msg(app, attr->type) < 0)
293 goto queue;
294 }
295
296 len = sizeof(*ga) + attr->dlen;
297 if (skb_tailroom(app->pdu) < len)
298 goto queue;
299 ga = __skb_put(app->pdu, len);
300 ga->len = len;
301 ga->event = event;
302 memcpy(ga->data, attr->data, attr->dlen);
303 return 0;
304
305 queue:
306 garp_pdu_queue(app);
307 goto again;
308 }
309
310 static void garp_attr_event(struct garp_applicant *app,
311 struct garp_attr *attr, enum garp_event event)
312 {
313 enum garp_applicant_state state;
314
315 state = garp_applicant_state_table[attr->state][event].state;
316 if (state == GARP_APPLICANT_INVALID)
317 return;
318
319 switch (garp_applicant_state_table[attr->state][event].action) {
320 case GARP_ACTION_NONE:
321 break;
322 case GARP_ACTION_S_JOIN_IN:
323 /* When appending the attribute fails, don't update state in
324 * order to retry on next TRANSMIT_PDU event. */
325 if (garp_pdu_append_attr(app, attr, GARP_JOIN_IN) < 0)
326 return;
327 break;
328 case GARP_ACTION_S_LEAVE_EMPTY:
329 garp_pdu_append_attr(app, attr, GARP_LEAVE_EMPTY);
330 /* As a pure applicant, sending a leave message implies that
331 * the attribute was unregistered and can be destroyed. */
332 garp_attr_destroy(app, attr);
333 return;
334 default:
335 WARN_ON(1);
336 }
337
338 attr->state = state;
339 }
340
341 int garp_request_join(const struct net_device *dev,
342 const struct garp_application *appl,
343 const void *data, u8 len, u8 type)
344 {
345 struct garp_port *port = rtnl_dereference(dev->garp_port);
346 struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]);
347 struct garp_attr *attr;
348
349 spin_lock_bh(&app->lock);
350 attr = garp_attr_create(app, data, len, type);
351 if (!attr) {
352 spin_unlock_bh(&app->lock);
353 return -ENOMEM;
354 }
355 garp_attr_event(app, attr, GARP_EVENT_REQ_JOIN);
356 spin_unlock_bh(&app->lock);
357 return 0;
358 }
359 EXPORT_SYMBOL_GPL(garp_request_join);
360
361 void garp_request_leave(const struct net_device *dev,
362 const struct garp_application *appl,
363 const void *data, u8 len, u8 type)
364 {
365 struct garp_port *port = rtnl_dereference(dev->garp_port);
366 struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]);
367 struct garp_attr *attr;
368
369 spin_lock_bh(&app->lock);
370 attr = garp_attr_lookup(app, data, len, type);
371 if (!attr) {
372 spin_unlock_bh(&app->lock);
373 return;
374 }
375 garp_attr_event(app, attr, GARP_EVENT_REQ_LEAVE);
376 spin_unlock_bh(&app->lock);
377 }
378 EXPORT_SYMBOL_GPL(garp_request_leave);
379
380 static void garp_gid_event(struct garp_applicant *app, enum garp_event event)
381 {
382 struct rb_node *node, *next;
383 struct garp_attr *attr;
384
385 for (node = rb_first(&app->gid);
386 next = node ? rb_next(node) : NULL, node != NULL;
387 node = next) {
388 attr = rb_entry(node, struct garp_attr, node);
389 garp_attr_event(app, attr, event);
390 }
391 }
392
393 static void garp_join_timer_arm(struct garp_applicant *app)
394 {
395 unsigned long delay;
396
397 delay = (u64)msecs_to_jiffies(garp_join_time) * prandom_u32() >> 32;
398 mod_timer(&app->join_timer, jiffies + delay);
399 }
400
401 static void garp_join_timer(struct timer_list *t)
402 {
403 struct garp_applicant *app = from_timer(app, t, join_timer);
404
405 spin_lock(&app->lock);
406 garp_gid_event(app, GARP_EVENT_TRANSMIT_PDU);
407 garp_pdu_queue(app);
408 spin_unlock(&app->lock);
409
410 garp_queue_xmit(app);
411 garp_join_timer_arm(app);
412 }
413
414 static int garp_pdu_parse_end_mark(struct sk_buff *skb)
415 {
416 if (!pskb_may_pull(skb, sizeof(u8)))
417 return -1;
418 if (*skb->data == GARP_END_MARK) {
419 skb_pull(skb, sizeof(u8));
420 return -1;
421 }
422 return 0;
423 }
424
425 static int garp_pdu_parse_attr(struct garp_applicant *app, struct sk_buff *skb,
426 u8 attrtype)
427 {
428 const struct garp_attr_hdr *ga;
429 struct garp_attr *attr;
430 enum garp_event event;
431 unsigned int dlen;
432
433 if (!pskb_may_pull(skb, sizeof(*ga)))
434 return -1;
435 ga = (struct garp_attr_hdr *)skb->data;
436 if (ga->len < sizeof(*ga))
437 return -1;
438
439 if (!pskb_may_pull(skb, ga->len))
440 return -1;
441 skb_pull(skb, ga->len);
442 dlen = sizeof(*ga) - ga->len;
443
444 if (attrtype > app->app->maxattr)
445 return 0;
446
447 switch (ga->event) {
448 case GARP_LEAVE_ALL:
449 if (dlen != 0)
450 return -1;
451 garp_gid_event(app, GARP_EVENT_R_LEAVE_EMPTY);
452 return 0;
453 case GARP_JOIN_EMPTY:
454 event = GARP_EVENT_R_JOIN_EMPTY;
455 break;
456 case GARP_JOIN_IN:
457 event = GARP_EVENT_R_JOIN_IN;
458 break;
459 case GARP_LEAVE_EMPTY:
460 event = GARP_EVENT_R_LEAVE_EMPTY;
461 break;
462 case GARP_EMPTY:
463 event = GARP_EVENT_R_EMPTY;
464 break;
465 default:
466 return 0;
467 }
468
469 if (dlen == 0)
470 return -1;
471 attr = garp_attr_lookup(app, ga->data, dlen, attrtype);
472 if (attr == NULL)
473 return 0;
474 garp_attr_event(app, attr, event);
475 return 0;
476 }
477
478 static int garp_pdu_parse_msg(struct garp_applicant *app, struct sk_buff *skb)
479 {
480 const struct garp_msg_hdr *gm;
481
482 if (!pskb_may_pull(skb, sizeof(*gm)))
483 return -1;
484 gm = (struct garp_msg_hdr *)skb->data;
485 if (gm->attrtype == 0)
486 return -1;
487 skb_pull(skb, sizeof(*gm));
488
489 while (skb->len > 0) {
490 if (garp_pdu_parse_attr(app, skb, gm->attrtype) < 0)
491 return -1;
492 if (garp_pdu_parse_end_mark(skb) < 0)
493 break;
494 }
495 return 0;
496 }
497
498 static void garp_pdu_rcv(const struct stp_proto *proto, struct sk_buff *skb,
499 struct net_device *dev)
500 {
501 struct garp_application *appl = proto->data;
502 struct garp_port *port;
503 struct garp_applicant *app;
504 const struct garp_pdu_hdr *gp;
505
506 port = rcu_dereference(dev->garp_port);
507 if (!port)
508 goto err;
509 app = rcu_dereference(port->applicants[appl->type]);
510 if (!app)
511 goto err;
512
513 if (!pskb_may_pull(skb, sizeof(*gp)))
514 goto err;
515 gp = (struct garp_pdu_hdr *)skb->data;
516 if (get_unaligned(&gp->protocol) != htons(GARP_PROTOCOL_ID))
517 goto err;
518 skb_pull(skb, sizeof(*gp));
519
520 spin_lock(&app->lock);
521 while (skb->len > 0) {
522 if (garp_pdu_parse_msg(app, skb) < 0)
523 break;
524 if (garp_pdu_parse_end_mark(skb) < 0)
525 break;
526 }
527 spin_unlock(&app->lock);
528 err:
529 kfree_skb(skb);
530 }
531
532 static int garp_init_port(struct net_device *dev)
533 {
534 struct garp_port *port;
535
536 port = kzalloc(sizeof(*port), GFP_KERNEL);
537 if (!port)
538 return -ENOMEM;
539 rcu_assign_pointer(dev->garp_port, port);
540 return 0;
541 }
542
543 static void garp_release_port(struct net_device *dev)
544 {
545 struct garp_port *port = rtnl_dereference(dev->garp_port);
546 unsigned int i;
547
548 for (i = 0; i <= GARP_APPLICATION_MAX; i++) {
549 if (rtnl_dereference(port->applicants[i]))
550 return;
551 }
552 RCU_INIT_POINTER(dev->garp_port, NULL);
553 kfree_rcu(port, rcu);
554 }
555
556 int garp_init_applicant(struct net_device *dev, struct garp_application *appl)
557 {
558 struct garp_applicant *app;
559 int err;
560
561 ASSERT_RTNL();
562
563 if (!rtnl_dereference(dev->garp_port)) {
564 err = garp_init_port(dev);
565 if (err < 0)
566 goto err1;
567 }
568
569 err = -ENOMEM;
570 app = kzalloc(sizeof(*app), GFP_KERNEL);
571 if (!app)
572 goto err2;
573
574 err = dev_mc_add(dev, appl->proto.group_address);
575 if (err < 0)
576 goto err3;
577
578 app->dev = dev;
579 app->app = appl;
580 app->gid = RB_ROOT;
581 spin_lock_init(&app->lock);
582 skb_queue_head_init(&app->queue);
583 rcu_assign_pointer(dev->garp_port->applicants[appl->type], app);
584 timer_setup(&app->join_timer, garp_join_timer, 0);
585 garp_join_timer_arm(app);
586 return 0;
587
588 err3:
589 kfree(app);
590 err2:
591 garp_release_port(dev);
592 err1:
593 return err;
594 }
595 EXPORT_SYMBOL_GPL(garp_init_applicant);
596
597 void garp_uninit_applicant(struct net_device *dev, struct garp_application *appl)
598 {
599 struct garp_port *port = rtnl_dereference(dev->garp_port);
600 struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]);
601
602 ASSERT_RTNL();
603
604 RCU_INIT_POINTER(port->applicants[appl->type], NULL);
605
606 /* Delete timer and generate a final TRANSMIT_PDU event to flush out
607 * all pending messages before the applicant is gone. */
608 del_timer_sync(&app->join_timer);
609
610 spin_lock_bh(&app->lock);
611 garp_gid_event(app, GARP_EVENT_TRANSMIT_PDU);
612 garp_pdu_queue(app);
613 spin_unlock_bh(&app->lock);
614
615 garp_queue_xmit(app);
616
617 dev_mc_del(dev, appl->proto.group_address);
618 kfree_rcu(app, rcu);
619 garp_release_port(dev);
620 }
621 EXPORT_SYMBOL_GPL(garp_uninit_applicant);
622
623 int garp_register_application(struct garp_application *appl)
624 {
625 appl->proto.rcv = garp_pdu_rcv;
626 appl->proto.data = appl;
627 return stp_proto_register(&appl->proto);
628 }
629 EXPORT_SYMBOL_GPL(garp_register_application);
630
631 void garp_unregister_application(struct garp_application *appl)
632 {
633 stp_proto_unregister(&appl->proto);
634 }
635 EXPORT_SYMBOL_GPL(garp_unregister_application);
Ubuntu Jammy Linux kernel mirror