xref: /linux/net/802/mrp.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *	IEEE 802.1Q Multiple Registration Protocol (MRP)
4  *
5  *	Copyright (c) 2012 Massachusetts Institute of Technology
6  *
7  *	Adapted from code in net/802/garp.c
8  *	Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
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/slab.h>
17 #include <linux/module.h>
18 #include <net/mrp.h>
19 #include <linux/unaligned.h>
20 
21 static unsigned int mrp_join_time __read_mostly = 200;
22 module_param(mrp_join_time, uint, 0644);
23 MODULE_PARM_DESC(mrp_join_time, "Join time in ms (default 200ms)");
24 
25 static unsigned int mrp_periodic_time __read_mostly = 1000;
26 module_param(mrp_periodic_time, uint, 0644);
27 MODULE_PARM_DESC(mrp_periodic_time, "Periodic time in ms (default 1s)");
28 
29 MODULE_DESCRIPTION("IEEE 802.1Q Multiple Registration Protocol (MRP)");
30 MODULE_LICENSE("GPL");
31 
32 static const u8
33 mrp_applicant_state_table[MRP_APPLICANT_MAX + 1][MRP_EVENT_MAX + 1] = {
34 	[MRP_APPLICANT_VO] = {
35 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
36 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_VP,
37 		[MRP_EVENT_LV]		= MRP_APPLICANT_VO,
38 		[MRP_EVENT_TX]		= MRP_APPLICANT_VO,
39 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_VO,
40 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_AO,
41 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_VO,
42 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_VO,
43 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_VO,
44 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VO,
45 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VO,
46 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VO,
47 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_VO,
48 	},
49 	[MRP_APPLICANT_VP] = {
50 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
51 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_VP,
52 		[MRP_EVENT_LV]		= MRP_APPLICANT_VO,
53 		[MRP_EVENT_TX]		= MRP_APPLICANT_AA,
54 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_VP,
55 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_AP,
56 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_VP,
57 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_VP,
58 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_VP,
59 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VP,
60 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VP,
61 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VP,
62 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_VP,
63 	},
64 	[MRP_APPLICANT_VN] = {
65 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
66 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_VN,
67 		[MRP_EVENT_LV]		= MRP_APPLICANT_LA,
68 		[MRP_EVENT_TX]		= MRP_APPLICANT_AN,
69 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_VN,
70 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_VN,
71 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_VN,
72 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_VN,
73 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_VN,
74 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VN,
75 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VN,
76 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VN,
77 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_VN,
78 	},
79 	[MRP_APPLICANT_AN] = {
80 		[MRP_EVENT_NEW]		= MRP_APPLICANT_AN,
81 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_AN,
82 		[MRP_EVENT_LV]		= MRP_APPLICANT_LA,
83 		[MRP_EVENT_TX]		= MRP_APPLICANT_QA,
84 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_AN,
85 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_AN,
86 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_AN,
87 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AN,
88 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AN,
89 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VN,
90 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VN,
91 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VN,
92 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AN,
93 	},
94 	[MRP_APPLICANT_AA] = {
95 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
96 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_AA,
97 		[MRP_EVENT_LV]		= MRP_APPLICANT_LA,
98 		[MRP_EVENT_TX]		= MRP_APPLICANT_QA,
99 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_AA,
100 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QA,
101 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_AA,
102 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AA,
103 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AA,
104 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VP,
105 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VP,
106 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VP,
107 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AA,
108 	},
109 	[MRP_APPLICANT_QA] = {
110 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
111 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_QA,
112 		[MRP_EVENT_LV]		= MRP_APPLICANT_LA,
113 		[MRP_EVENT_TX]		= MRP_APPLICANT_QA,
114 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_QA,
115 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QA,
116 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_QA,
117 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AA,
118 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AA,
119 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VP,
120 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VP,
121 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VP,
122 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AA,
123 	},
124 	[MRP_APPLICANT_LA] = {
125 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
126 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_AA,
127 		[MRP_EVENT_LV]		= MRP_APPLICANT_LA,
128 		[MRP_EVENT_TX]		= MRP_APPLICANT_VO,
129 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_LA,
130 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_LA,
131 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_LA,
132 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_LA,
133 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_LA,
134 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_LA,
135 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_LA,
136 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_LA,
137 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_LA,
138 	},
139 	[MRP_APPLICANT_AO] = {
140 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
141 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_AP,
142 		[MRP_EVENT_LV]		= MRP_APPLICANT_AO,
143 		[MRP_EVENT_TX]		= MRP_APPLICANT_AO,
144 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_AO,
145 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QO,
146 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_AO,
147 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AO,
148 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AO,
149 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VO,
150 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VO,
151 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VO,
152 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AO,
153 	},
154 	[MRP_APPLICANT_QO] = {
155 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
156 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_QP,
157 		[MRP_EVENT_LV]		= MRP_APPLICANT_QO,
158 		[MRP_EVENT_TX]		= MRP_APPLICANT_QO,
159 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_QO,
160 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QO,
161 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_QO,
162 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AO,
163 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AO,
164 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VO,
165 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VO,
166 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VO,
167 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_QO,
168 	},
169 	[MRP_APPLICANT_AP] = {
170 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
171 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_AP,
172 		[MRP_EVENT_LV]		= MRP_APPLICANT_AO,
173 		[MRP_EVENT_TX]		= MRP_APPLICANT_QA,
174 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_AP,
175 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QP,
176 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_AP,
177 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AP,
178 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AP,
179 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VP,
180 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VP,
181 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VP,
182 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AP,
183 	},
184 	[MRP_APPLICANT_QP] = {
185 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
186 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_QP,
187 		[MRP_EVENT_LV]		= MRP_APPLICANT_QO,
188 		[MRP_EVENT_TX]		= MRP_APPLICANT_QP,
189 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_QP,
190 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QP,
191 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_QP,
192 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AP,
193 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AP,
194 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VP,
195 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VP,
196 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VP,
197 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AP,
198 	},
199 };
200 
201 static const u8
202 mrp_tx_action_table[MRP_APPLICANT_MAX + 1] = {
203 	[MRP_APPLICANT_VO] = MRP_TX_ACTION_S_IN_OPTIONAL,
204 	[MRP_APPLICANT_VP] = MRP_TX_ACTION_S_JOIN_IN,
205 	[MRP_APPLICANT_VN] = MRP_TX_ACTION_S_NEW,
206 	[MRP_APPLICANT_AN] = MRP_TX_ACTION_S_NEW,
207 	[MRP_APPLICANT_AA] = MRP_TX_ACTION_S_JOIN_IN,
208 	[MRP_APPLICANT_QA] = MRP_TX_ACTION_S_JOIN_IN_OPTIONAL,
209 	[MRP_APPLICANT_LA] = MRP_TX_ACTION_S_LV,
210 	[MRP_APPLICANT_AO] = MRP_TX_ACTION_S_IN_OPTIONAL,
211 	[MRP_APPLICANT_QO] = MRP_TX_ACTION_S_IN_OPTIONAL,
212 	[MRP_APPLICANT_AP] = MRP_TX_ACTION_S_JOIN_IN,
213 	[MRP_APPLICANT_QP] = MRP_TX_ACTION_S_IN_OPTIONAL,
214 };
215 
216 static void mrp_attrvalue_inc(void *value, u8 len)
217 {
218 	u8 *v = (u8 *)value;
219 
220 	/* Add 1 to the last byte. If it becomes zero,
221 	 * go to the previous byte and repeat.
222 	 */
223 	while (len > 0 && !++v[--len])
224 		;
225 }
226 
227 static int mrp_attr_cmp(const struct mrp_attr *attr,
228 			 const void *value, u8 len, u8 type)
229 {
230 	if (attr->type != type)
231 		return attr->type - type;
232 	if (attr->len != len)
233 		return attr->len - len;
234 	return memcmp(attr->value, value, len);
235 }
236 
237 static struct mrp_attr *mrp_attr_lookup(const struct mrp_applicant *app,
238 					const void *value, u8 len, u8 type)
239 {
240 	struct rb_node *parent = app->mad.rb_node;
241 	struct mrp_attr *attr;
242 	int d;
243 
244 	while (parent) {
245 		attr = rb_entry(parent, struct mrp_attr, node);
246 		d = mrp_attr_cmp(attr, value, len, type);
247 		if (d > 0)
248 			parent = parent->rb_left;
249 		else if (d < 0)
250 			parent = parent->rb_right;
251 		else
252 			return attr;
253 	}
254 	return NULL;
255 }
256 
257 static struct mrp_attr *mrp_attr_create(struct mrp_applicant *app,
258 					const void *value, u8 len, u8 type)
259 {
260 	struct rb_node *parent = NULL, **p = &app->mad.rb_node;
261 	struct mrp_attr *attr;
262 	int d;
263 
264 	while (*p) {
265 		parent = *p;
266 		attr = rb_entry(parent, struct mrp_attr, node);
267 		d = mrp_attr_cmp(attr, value, len, type);
268 		if (d > 0)
269 			p = &parent->rb_left;
270 		else if (d < 0)
271 			p = &parent->rb_right;
272 		else {
273 			/* The attribute already exists; re-use it. */
274 			return attr;
275 		}
276 	}
277 	attr = kmalloc(sizeof(*attr) + len, GFP_ATOMIC);
278 	if (!attr)
279 		return attr;
280 	attr->state = MRP_APPLICANT_VO;
281 	attr->type  = type;
282 	attr->len   = len;
283 	memcpy(attr->value, value, len);
284 
285 	rb_link_node(&attr->node, parent, p);
286 	rb_insert_color(&attr->node, &app->mad);
287 	return attr;
288 }
289 
290 static void mrp_attr_destroy(struct mrp_applicant *app, struct mrp_attr *attr)
291 {
292 	rb_erase(&attr->node, &app->mad);
293 	kfree(attr);
294 }
295 
296 static void mrp_attr_destroy_all(struct mrp_applicant *app)
297 {
298 	struct rb_node *node, *next;
299 	struct mrp_attr *attr;
300 
301 	for (node = rb_first(&app->mad);
302 	     next = node ? rb_next(node) : NULL, node != NULL;
303 	     node = next) {
304 		attr = rb_entry(node, struct mrp_attr, node);
305 		mrp_attr_destroy(app, attr);
306 	}
307 }
308 
309 static int mrp_pdu_init(struct mrp_applicant *app)
310 {
311 	struct sk_buff *skb;
312 	struct mrp_pdu_hdr *ph;
313 
314 	skb = alloc_skb(app->dev->mtu + LL_RESERVED_SPACE(app->dev),
315 			GFP_ATOMIC);
316 	if (!skb)
317 		return -ENOMEM;
318 
319 	skb->dev = app->dev;
320 	skb->protocol = app->app->pkttype.type;
321 	skb_reserve(skb, LL_RESERVED_SPACE(app->dev));
322 	skb_reset_network_header(skb);
323 	skb_reset_transport_header(skb);
324 
325 	ph = __skb_put(skb, sizeof(*ph));
326 	ph->version = app->app->version;
327 
328 	app->pdu = skb;
329 	return 0;
330 }
331 
332 static int mrp_pdu_append_end_mark(struct mrp_applicant *app)
333 {
334 	__be16 *endmark;
335 
336 	if (skb_tailroom(app->pdu) < sizeof(*endmark))
337 		return -1;
338 	endmark = __skb_put(app->pdu, sizeof(*endmark));
339 	put_unaligned(MRP_END_MARK, endmark);
340 	return 0;
341 }
342 
343 static void mrp_pdu_queue(struct mrp_applicant *app)
344 {
345 	if (!app->pdu)
346 		return;
347 
348 	if (mrp_cb(app->pdu)->mh)
349 		mrp_pdu_append_end_mark(app);
350 	mrp_pdu_append_end_mark(app);
351 
352 	dev_hard_header(app->pdu, app->dev, ntohs(app->app->pkttype.type),
353 			app->app->group_address, app->dev->dev_addr,
354 			app->pdu->len);
355 
356 	skb_queue_tail(&app->queue, app->pdu);
357 	app->pdu = NULL;
358 }
359 
360 static void mrp_queue_xmit(struct mrp_applicant *app)
361 {
362 	struct sk_buff *skb;
363 
364 	while ((skb = skb_dequeue(&app->queue)))
365 		dev_queue_xmit(skb);
366 }
367 
368 static int mrp_pdu_append_msg_hdr(struct mrp_applicant *app,
369 				  u8 attrtype, u8 attrlen)
370 {
371 	struct mrp_msg_hdr *mh;
372 
373 	if (mrp_cb(app->pdu)->mh) {
374 		if (mrp_pdu_append_end_mark(app) < 0)
375 			return -1;
376 		mrp_cb(app->pdu)->mh = NULL;
377 		mrp_cb(app->pdu)->vah = NULL;
378 	}
379 
380 	if (skb_tailroom(app->pdu) < sizeof(*mh))
381 		return -1;
382 	mh = __skb_put(app->pdu, sizeof(*mh));
383 	mh->attrtype = attrtype;
384 	mh->attrlen = attrlen;
385 	mrp_cb(app->pdu)->mh = mh;
386 	return 0;
387 }
388 
389 static int mrp_pdu_append_vecattr_hdr(struct mrp_applicant *app,
390 				      const void *firstattrvalue, u8 attrlen)
391 {
392 	struct mrp_vecattr_hdr *vah;
393 
394 	if (skb_tailroom(app->pdu) < sizeof(*vah) + attrlen)
395 		return -1;
396 	vah = __skb_put(app->pdu, sizeof(*vah) + attrlen);
397 	put_unaligned(0, &vah->lenflags);
398 	memcpy(vah->firstattrvalue, firstattrvalue, attrlen);
399 	mrp_cb(app->pdu)->vah = vah;
400 	memcpy(mrp_cb(app->pdu)->attrvalue, firstattrvalue, attrlen);
401 	return 0;
402 }
403 
404 static int mrp_pdu_append_vecattr_event(struct mrp_applicant *app,
405 					const struct mrp_attr *attr,
406 					enum mrp_vecattr_event vaevent)
407 {
408 	u16 len, pos;
409 	u8 *vaevents;
410 	int err;
411 again:
412 	if (!app->pdu) {
413 		err = mrp_pdu_init(app);
414 		if (err < 0)
415 			return err;
416 	}
417 
418 	/* If there is no Message header in the PDU, or the Message header is
419 	 * for a different attribute type, add an EndMark (if necessary) and a
420 	 * new Message header to the PDU.
421 	 */
422 	if (!mrp_cb(app->pdu)->mh ||
423 	    mrp_cb(app->pdu)->mh->attrtype != attr->type ||
424 	    mrp_cb(app->pdu)->mh->attrlen != attr->len) {
425 		if (mrp_pdu_append_msg_hdr(app, attr->type, attr->len) < 0)
426 			goto queue;
427 	}
428 
429 	/* If there is no VectorAttribute header for this Message in the PDU,
430 	 * or this attribute's value does not sequentially follow the previous
431 	 * attribute's value, add a new VectorAttribute header to the PDU.
432 	 */
433 	if (!mrp_cb(app->pdu)->vah ||
434 	    memcmp(mrp_cb(app->pdu)->attrvalue, attr->value, attr->len)) {
435 		if (mrp_pdu_append_vecattr_hdr(app, attr->value, attr->len) < 0)
436 			goto queue;
437 	}
438 
439 	len = be16_to_cpu(get_unaligned(&mrp_cb(app->pdu)->vah->lenflags));
440 	pos = len % 3;
441 
442 	/* Events are packed into Vectors in the PDU, three to a byte. Add a
443 	 * byte to the end of the Vector if necessary.
444 	 */
445 	if (!pos) {
446 		if (skb_tailroom(app->pdu) < sizeof(u8))
447 			goto queue;
448 		vaevents = __skb_put(app->pdu, sizeof(u8));
449 	} else {
450 		vaevents = (u8 *)(skb_tail_pointer(app->pdu) - sizeof(u8));
451 	}
452 
453 	switch (pos) {
454 	case 0:
455 		*vaevents = vaevent * (__MRP_VECATTR_EVENT_MAX *
456 				       __MRP_VECATTR_EVENT_MAX);
457 		break;
458 	case 1:
459 		*vaevents += vaevent * __MRP_VECATTR_EVENT_MAX;
460 		break;
461 	case 2:
462 		*vaevents += vaevent;
463 		break;
464 	default:
465 		WARN_ON(1);
466 	}
467 
468 	/* Increment the length of the VectorAttribute in the PDU, as well as
469 	 * the value of the next attribute that would continue its Vector.
470 	 */
471 	put_unaligned(cpu_to_be16(++len), &mrp_cb(app->pdu)->vah->lenflags);
472 	mrp_attrvalue_inc(mrp_cb(app->pdu)->attrvalue, attr->len);
473 
474 	return 0;
475 
476 queue:
477 	mrp_pdu_queue(app);
478 	goto again;
479 }
480 
481 static void mrp_attr_event(struct mrp_applicant *app,
482 			   struct mrp_attr *attr, enum mrp_event event)
483 {
484 	enum mrp_applicant_state state;
485 
486 	state = mrp_applicant_state_table[attr->state][event];
487 	if (state == MRP_APPLICANT_INVALID) {
488 		WARN_ON(1);
489 		return;
490 	}
491 
492 	if (event == MRP_EVENT_TX) {
493 		/* When appending the attribute fails, don't update its state
494 		 * in order to retry at the next TX event.
495 		 */
496 
497 		switch (mrp_tx_action_table[attr->state]) {
498 		case MRP_TX_ACTION_NONE:
499 		case MRP_TX_ACTION_S_JOIN_IN_OPTIONAL:
500 		case MRP_TX_ACTION_S_IN_OPTIONAL:
501 			break;
502 		case MRP_TX_ACTION_S_NEW:
503 			if (mrp_pdu_append_vecattr_event(
504 				    app, attr, MRP_VECATTR_EVENT_NEW) < 0)
505 				return;
506 			break;
507 		case MRP_TX_ACTION_S_JOIN_IN:
508 			if (mrp_pdu_append_vecattr_event(
509 				    app, attr, MRP_VECATTR_EVENT_JOIN_IN) < 0)
510 				return;
511 			break;
512 		case MRP_TX_ACTION_S_LV:
513 			if (mrp_pdu_append_vecattr_event(
514 				    app, attr, MRP_VECATTR_EVENT_LV) < 0)
515 				return;
516 			/* As a pure applicant, sending a leave message
517 			 * implies that the attribute was unregistered and
518 			 * can be destroyed.
519 			 */
520 			mrp_attr_destroy(app, attr);
521 			return;
522 		default:
523 			WARN_ON(1);
524 		}
525 	}
526 
527 	attr->state = state;
528 }
529 
530 int mrp_request_join(const struct net_device *dev,
531 		     const struct mrp_application *appl,
532 		     const void *value, u8 len, u8 type)
533 {
534 	struct mrp_port *port = rtnl_dereference(dev->mrp_port);
535 	struct mrp_applicant *app = rtnl_dereference(
536 		port->applicants[appl->type]);
537 	struct mrp_attr *attr;
538 
539 	if (sizeof(struct mrp_skb_cb) + len >
540 	    sizeof_field(struct sk_buff, cb))
541 		return -ENOMEM;
542 
543 	spin_lock_bh(&app->lock);
544 	attr = mrp_attr_create(app, value, len, type);
545 	if (!attr) {
546 		spin_unlock_bh(&app->lock);
547 		return -ENOMEM;
548 	}
549 	mrp_attr_event(app, attr, MRP_EVENT_JOIN);
550 	spin_unlock_bh(&app->lock);
551 	return 0;
552 }
553 EXPORT_SYMBOL_GPL(mrp_request_join);
554 
555 void mrp_request_leave(const struct net_device *dev,
556 		       const struct mrp_application *appl,
557 		       const void *value, u8 len, u8 type)
558 {
559 	struct mrp_port *port = rtnl_dereference(dev->mrp_port);
560 	struct mrp_applicant *app = rtnl_dereference(
561 		port->applicants[appl->type]);
562 	struct mrp_attr *attr;
563 
564 	if (sizeof(struct mrp_skb_cb) + len >
565 	    sizeof_field(struct sk_buff, cb))
566 		return;
567 
568 	spin_lock_bh(&app->lock);
569 	attr = mrp_attr_lookup(app, value, len, type);
570 	if (!attr) {
571 		spin_unlock_bh(&app->lock);
572 		return;
573 	}
574 	mrp_attr_event(app, attr, MRP_EVENT_LV);
575 	spin_unlock_bh(&app->lock);
576 }
577 EXPORT_SYMBOL_GPL(mrp_request_leave);
578 
579 static void mrp_mad_event(struct mrp_applicant *app, enum mrp_event event)
580 {
581 	struct rb_node *node, *next;
582 	struct mrp_attr *attr;
583 
584 	for (node = rb_first(&app->mad);
585 	     next = node ? rb_next(node) : NULL, node != NULL;
586 	     node = next) {
587 		attr = rb_entry(node, struct mrp_attr, node);
588 		mrp_attr_event(app, attr, event);
589 	}
590 }
591 
592 static void mrp_join_timer_arm(struct mrp_applicant *app)
593 {
594 	unsigned long delay;
595 
596 	delay = get_random_u32_below(msecs_to_jiffies(mrp_join_time));
597 	mod_timer(&app->join_timer, jiffies + delay);
598 }
599 
600 static void mrp_join_timer(struct timer_list *t)
601 {
602 	struct mrp_applicant *app = from_timer(app, t, join_timer);
603 
604 	spin_lock(&app->lock);
605 	mrp_mad_event(app, MRP_EVENT_TX);
606 	mrp_pdu_queue(app);
607 	spin_unlock(&app->lock);
608 
609 	mrp_queue_xmit(app);
610 	spin_lock(&app->lock);
611 	if (likely(app->active))
612 		mrp_join_timer_arm(app);
613 	spin_unlock(&app->lock);
614 }
615 
616 static void mrp_periodic_timer_arm(struct mrp_applicant *app)
617 {
618 	mod_timer(&app->periodic_timer,
619 		  jiffies + msecs_to_jiffies(mrp_periodic_time));
620 }
621 
622 static void mrp_periodic_timer(struct timer_list *t)
623 {
624 	struct mrp_applicant *app = from_timer(app, t, periodic_timer);
625 
626 	spin_lock(&app->lock);
627 	if (likely(app->active)) {
628 		mrp_mad_event(app, MRP_EVENT_PERIODIC);
629 		mrp_pdu_queue(app);
630 		mrp_periodic_timer_arm(app);
631 	}
632 	spin_unlock(&app->lock);
633 }
634 
635 static int mrp_pdu_parse_end_mark(struct sk_buff *skb, int *offset)
636 {
637 	__be16 endmark;
638 
639 	if (skb_copy_bits(skb, *offset, &endmark, sizeof(endmark)) < 0)
640 		return -1;
641 	if (endmark == MRP_END_MARK) {
642 		*offset += sizeof(endmark);
643 		return -1;
644 	}
645 	return 0;
646 }
647 
648 static void mrp_pdu_parse_vecattr_event(struct mrp_applicant *app,
649 					struct sk_buff *skb,
650 					enum mrp_vecattr_event vaevent)
651 {
652 	struct mrp_attr *attr;
653 	enum mrp_event event;
654 
655 	attr = mrp_attr_lookup(app, mrp_cb(skb)->attrvalue,
656 			       mrp_cb(skb)->mh->attrlen,
657 			       mrp_cb(skb)->mh->attrtype);
658 	if (attr == NULL)
659 		return;
660 
661 	switch (vaevent) {
662 	case MRP_VECATTR_EVENT_NEW:
663 		event = MRP_EVENT_R_NEW;
664 		break;
665 	case MRP_VECATTR_EVENT_JOIN_IN:
666 		event = MRP_EVENT_R_JOIN_IN;
667 		break;
668 	case MRP_VECATTR_EVENT_IN:
669 		event = MRP_EVENT_R_IN;
670 		break;
671 	case MRP_VECATTR_EVENT_JOIN_MT:
672 		event = MRP_EVENT_R_JOIN_MT;
673 		break;
674 	case MRP_VECATTR_EVENT_MT:
675 		event = MRP_EVENT_R_MT;
676 		break;
677 	case MRP_VECATTR_EVENT_LV:
678 		event = MRP_EVENT_R_LV;
679 		break;
680 	default:
681 		return;
682 	}
683 
684 	mrp_attr_event(app, attr, event);
685 }
686 
687 static int mrp_pdu_parse_vecattr(struct mrp_applicant *app,
688 				 struct sk_buff *skb, int *offset)
689 {
690 	struct mrp_vecattr_hdr _vah;
691 	u16 valen;
692 	u8 vaevents, vaevent;
693 
694 	mrp_cb(skb)->vah = skb_header_pointer(skb, *offset, sizeof(_vah),
695 					      &_vah);
696 	if (!mrp_cb(skb)->vah)
697 		return -1;
698 	*offset += sizeof(_vah);
699 
700 	if (get_unaligned(&mrp_cb(skb)->vah->lenflags) &
701 	    MRP_VECATTR_HDR_FLAG_LA)
702 		mrp_mad_event(app, MRP_EVENT_R_LA);
703 	valen = be16_to_cpu(get_unaligned(&mrp_cb(skb)->vah->lenflags) &
704 			    MRP_VECATTR_HDR_LEN_MASK);
705 
706 	/* The VectorAttribute structure in a PDU carries event information
707 	 * about one or more attributes having consecutive values. Only the
708 	 * value for the first attribute is contained in the structure. So
709 	 * we make a copy of that value, and then increment it each time we
710 	 * advance to the next event in its Vector.
711 	 */
712 	if (sizeof(struct mrp_skb_cb) + mrp_cb(skb)->mh->attrlen >
713 	    sizeof_field(struct sk_buff, cb))
714 		return -1;
715 	if (skb_copy_bits(skb, *offset, mrp_cb(skb)->attrvalue,
716 			  mrp_cb(skb)->mh->attrlen) < 0)
717 		return -1;
718 	*offset += mrp_cb(skb)->mh->attrlen;
719 
720 	/* In a VectorAttribute, the Vector contains events which are packed
721 	 * three to a byte. We process one byte of the Vector at a time.
722 	 */
723 	while (valen > 0) {
724 		if (skb_copy_bits(skb, *offset, &vaevents,
725 				  sizeof(vaevents)) < 0)
726 			return -1;
727 		*offset += sizeof(vaevents);
728 
729 		/* Extract and process the first event. */
730 		vaevent = vaevents / (__MRP_VECATTR_EVENT_MAX *
731 				      __MRP_VECATTR_EVENT_MAX);
732 		if (vaevent >= __MRP_VECATTR_EVENT_MAX) {
733 			/* The byte is malformed; stop processing. */
734 			return -1;
735 		}
736 		mrp_pdu_parse_vecattr_event(app, skb, vaevent);
737 
738 		/* If present, extract and process the second event. */
739 		if (!--valen)
740 			break;
741 		mrp_attrvalue_inc(mrp_cb(skb)->attrvalue,
742 				  mrp_cb(skb)->mh->attrlen);
743 		vaevents %= (__MRP_VECATTR_EVENT_MAX *
744 			     __MRP_VECATTR_EVENT_MAX);
745 		vaevent = vaevents / __MRP_VECATTR_EVENT_MAX;
746 		mrp_pdu_parse_vecattr_event(app, skb, vaevent);
747 
748 		/* If present, extract and process the third event. */
749 		if (!--valen)
750 			break;
751 		mrp_attrvalue_inc(mrp_cb(skb)->attrvalue,
752 				  mrp_cb(skb)->mh->attrlen);
753 		vaevents %= __MRP_VECATTR_EVENT_MAX;
754 		vaevent = vaevents;
755 		mrp_pdu_parse_vecattr_event(app, skb, vaevent);
756 	}
757 	return 0;
758 }
759 
760 static int mrp_pdu_parse_msg(struct mrp_applicant *app, struct sk_buff *skb,
761 			     int *offset)
762 {
763 	struct mrp_msg_hdr _mh;
764 
765 	mrp_cb(skb)->mh = skb_header_pointer(skb, *offset, sizeof(_mh), &_mh);
766 	if (!mrp_cb(skb)->mh)
767 		return -1;
768 	*offset += sizeof(_mh);
769 
770 	if (mrp_cb(skb)->mh->attrtype == 0 ||
771 	    mrp_cb(skb)->mh->attrtype > app->app->maxattr ||
772 	    mrp_cb(skb)->mh->attrlen == 0)
773 		return -1;
774 
775 	while (skb->len > *offset) {
776 		if (mrp_pdu_parse_end_mark(skb, offset) < 0)
777 			break;
778 		if (mrp_pdu_parse_vecattr(app, skb, offset) < 0)
779 			return -1;
780 	}
781 	return 0;
782 }
783 
784 static int mrp_rcv(struct sk_buff *skb, struct net_device *dev,
785 		   struct packet_type *pt, struct net_device *orig_dev)
786 {
787 	struct mrp_application *appl = container_of(pt, struct mrp_application,
788 						    pkttype);
789 	struct mrp_port *port;
790 	struct mrp_applicant *app;
791 	struct mrp_pdu_hdr _ph;
792 	const struct mrp_pdu_hdr *ph;
793 	int offset = skb_network_offset(skb);
794 
795 	/* If the interface is in promiscuous mode, drop the packet if
796 	 * it was unicast to another host.
797 	 */
798 	if (unlikely(skb->pkt_type == PACKET_OTHERHOST))
799 		goto out;
800 	skb = skb_share_check(skb, GFP_ATOMIC);
801 	if (unlikely(!skb))
802 		goto out;
803 	port = rcu_dereference(dev->mrp_port);
804 	if (unlikely(!port))
805 		goto out;
806 	app = rcu_dereference(port->applicants[appl->type]);
807 	if (unlikely(!app))
808 		goto out;
809 
810 	ph = skb_header_pointer(skb, offset, sizeof(_ph), &_ph);
811 	if (!ph)
812 		goto out;
813 	offset += sizeof(_ph);
814 
815 	if (ph->version != app->app->version)
816 		goto out;
817 
818 	spin_lock(&app->lock);
819 	while (skb->len > offset) {
820 		if (mrp_pdu_parse_end_mark(skb, &offset) < 0)
821 			break;
822 		if (mrp_pdu_parse_msg(app, skb, &offset) < 0)
823 			break;
824 	}
825 	spin_unlock(&app->lock);
826 out:
827 	kfree_skb(skb);
828 	return 0;
829 }
830 
831 static int mrp_init_port(struct net_device *dev)
832 {
833 	struct mrp_port *port;
834 
835 	port = kzalloc(sizeof(*port), GFP_KERNEL);
836 	if (!port)
837 		return -ENOMEM;
838 	rcu_assign_pointer(dev->mrp_port, port);
839 	return 0;
840 }
841 
842 static void mrp_release_port(struct net_device *dev)
843 {
844 	struct mrp_port *port = rtnl_dereference(dev->mrp_port);
845 	unsigned int i;
846 
847 	for (i = 0; i <= MRP_APPLICATION_MAX; i++) {
848 		if (rtnl_dereference(port->applicants[i]))
849 			return;
850 	}
851 	RCU_INIT_POINTER(dev->mrp_port, NULL);
852 	kfree_rcu(port, rcu);
853 }
854 
855 int mrp_init_applicant(struct net_device *dev, struct mrp_application *appl)
856 {
857 	struct mrp_applicant *app;
858 	int err;
859 
860 	ASSERT_RTNL();
861 
862 	if (!rtnl_dereference(dev->mrp_port)) {
863 		err = mrp_init_port(dev);
864 		if (err < 0)
865 			goto err1;
866 	}
867 
868 	err = -ENOMEM;
869 	app = kzalloc(sizeof(*app), GFP_KERNEL);
870 	if (!app)
871 		goto err2;
872 
873 	err = dev_mc_add(dev, appl->group_address);
874 	if (err < 0)
875 		goto err3;
876 
877 	app->dev = dev;
878 	app->app = appl;
879 	app->mad = RB_ROOT;
880 	app->active = true;
881 	spin_lock_init(&app->lock);
882 	skb_queue_head_init(&app->queue);
883 	rcu_assign_pointer(dev->mrp_port->applicants[appl->type], app);
884 	timer_setup(&app->join_timer, mrp_join_timer, 0);
885 	mrp_join_timer_arm(app);
886 	timer_setup(&app->periodic_timer, mrp_periodic_timer, 0);
887 	mrp_periodic_timer_arm(app);
888 	return 0;
889 
890 err3:
891 	kfree(app);
892 err2:
893 	mrp_release_port(dev);
894 err1:
895 	return err;
896 }
897 EXPORT_SYMBOL_GPL(mrp_init_applicant);
898 
899 void mrp_uninit_applicant(struct net_device *dev, struct mrp_application *appl)
900 {
901 	struct mrp_port *port = rtnl_dereference(dev->mrp_port);
902 	struct mrp_applicant *app = rtnl_dereference(
903 		port->applicants[appl->type]);
904 
905 	ASSERT_RTNL();
906 
907 	RCU_INIT_POINTER(port->applicants[appl->type], NULL);
908 
909 	spin_lock_bh(&app->lock);
910 	app->active = false;
911 	spin_unlock_bh(&app->lock);
912 	/* Delete timer and generate a final TX event to flush out
913 	 * all pending messages before the applicant is gone.
914 	 */
915 	timer_shutdown_sync(&app->join_timer);
916 	timer_shutdown_sync(&app->periodic_timer);
917 
918 	spin_lock_bh(&app->lock);
919 	mrp_mad_event(app, MRP_EVENT_TX);
920 	mrp_attr_destroy_all(app);
921 	mrp_pdu_queue(app);
922 	spin_unlock_bh(&app->lock);
923 
924 	mrp_queue_xmit(app);
925 
926 	dev_mc_del(dev, appl->group_address);
927 	kfree_rcu(app, rcu);
928 	mrp_release_port(dev);
929 }
930 EXPORT_SYMBOL_GPL(mrp_uninit_applicant);
931 
932 int mrp_register_application(struct mrp_application *appl)
933 {
934 	appl->pkttype.func = mrp_rcv;
935 	dev_add_pack(&appl->pkttype);
936 	return 0;
937 }
938 EXPORT_SYMBOL_GPL(mrp_register_application);
939 
940 void mrp_unregister_application(struct mrp_application *appl)
941 {
942 	dev_remove_pack(&appl->pkttype);
943 }
944 EXPORT_SYMBOL_GPL(mrp_unregister_application);
945