xref: /openbmc/linux/net/802/mrp.c (revision 5e012745)
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 <asm/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_LICENSE("GPL");
30 
31 static const u8
32 mrp_applicant_state_table[MRP_APPLICANT_MAX + 1][MRP_EVENT_MAX + 1] = {
33 	[MRP_APPLICANT_VO] = {
34 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
35 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_VP,
36 		[MRP_EVENT_LV]		= MRP_APPLICANT_VO,
37 		[MRP_EVENT_TX]		= MRP_APPLICANT_VO,
38 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_VO,
39 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_AO,
40 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_VO,
41 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_VO,
42 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_VO,
43 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VO,
44 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VO,
45 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VO,
46 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_VO,
47 	},
48 	[MRP_APPLICANT_VP] = {
49 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
50 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_VP,
51 		[MRP_EVENT_LV]		= MRP_APPLICANT_VO,
52 		[MRP_EVENT_TX]		= MRP_APPLICANT_AA,
53 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_VP,
54 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_AP,
55 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_VP,
56 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_VP,
57 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_VP,
58 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VP,
59 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VP,
60 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VP,
61 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_VP,
62 	},
63 	[MRP_APPLICANT_VN] = {
64 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
65 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_VN,
66 		[MRP_EVENT_LV]		= MRP_APPLICANT_LA,
67 		[MRP_EVENT_TX]		= MRP_APPLICANT_AN,
68 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_VN,
69 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_VN,
70 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_VN,
71 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_VN,
72 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_VN,
73 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VN,
74 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VN,
75 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VN,
76 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_VN,
77 	},
78 	[MRP_APPLICANT_AN] = {
79 		[MRP_EVENT_NEW]		= MRP_APPLICANT_AN,
80 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_AN,
81 		[MRP_EVENT_LV]		= MRP_APPLICANT_LA,
82 		[MRP_EVENT_TX]		= MRP_APPLICANT_QA,
83 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_AN,
84 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_AN,
85 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_AN,
86 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AN,
87 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AN,
88 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VN,
89 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VN,
90 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VN,
91 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AN,
92 	},
93 	[MRP_APPLICANT_AA] = {
94 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
95 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_AA,
96 		[MRP_EVENT_LV]		= MRP_APPLICANT_LA,
97 		[MRP_EVENT_TX]		= MRP_APPLICANT_QA,
98 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_AA,
99 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QA,
100 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_AA,
101 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AA,
102 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AA,
103 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VP,
104 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VP,
105 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VP,
106 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AA,
107 	},
108 	[MRP_APPLICANT_QA] = {
109 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
110 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_QA,
111 		[MRP_EVENT_LV]		= MRP_APPLICANT_LA,
112 		[MRP_EVENT_TX]		= MRP_APPLICANT_QA,
113 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_QA,
114 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QA,
115 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_QA,
116 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AA,
117 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AA,
118 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VP,
119 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VP,
120 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VP,
121 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AA,
122 	},
123 	[MRP_APPLICANT_LA] = {
124 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
125 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_AA,
126 		[MRP_EVENT_LV]		= MRP_APPLICANT_LA,
127 		[MRP_EVENT_TX]		= MRP_APPLICANT_VO,
128 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_LA,
129 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_LA,
130 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_LA,
131 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_LA,
132 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_LA,
133 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_LA,
134 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_LA,
135 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_LA,
136 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_LA,
137 	},
138 	[MRP_APPLICANT_AO] = {
139 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
140 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_AP,
141 		[MRP_EVENT_LV]		= MRP_APPLICANT_AO,
142 		[MRP_EVENT_TX]		= MRP_APPLICANT_AO,
143 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_AO,
144 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QO,
145 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_AO,
146 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AO,
147 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AO,
148 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VO,
149 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VO,
150 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VO,
151 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AO,
152 	},
153 	[MRP_APPLICANT_QO] = {
154 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
155 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_QP,
156 		[MRP_EVENT_LV]		= MRP_APPLICANT_QO,
157 		[MRP_EVENT_TX]		= MRP_APPLICANT_QO,
158 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_QO,
159 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QO,
160 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_QO,
161 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AO,
162 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AO,
163 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VO,
164 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VO,
165 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VO,
166 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_QO,
167 	},
168 	[MRP_APPLICANT_AP] = {
169 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
170 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_AP,
171 		[MRP_EVENT_LV]		= MRP_APPLICANT_AO,
172 		[MRP_EVENT_TX]		= MRP_APPLICANT_QA,
173 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_AP,
174 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QP,
175 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_AP,
176 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AP,
177 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AP,
178 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VP,
179 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VP,
180 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VP,
181 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AP,
182 	},
183 	[MRP_APPLICANT_QP] = {
184 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
185 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_QP,
186 		[MRP_EVENT_LV]		= MRP_APPLICANT_QO,
187 		[MRP_EVENT_TX]		= MRP_APPLICANT_QP,
188 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_QP,
189 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QP,
190 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_QP,
191 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AP,
192 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AP,
193 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VP,
194 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VP,
195 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VP,
196 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AP,
197 	},
198 };
199 
200 static const u8
201 mrp_tx_action_table[MRP_APPLICANT_MAX + 1] = {
202 	[MRP_APPLICANT_VO] = MRP_TX_ACTION_S_IN_OPTIONAL,
203 	[MRP_APPLICANT_VP] = MRP_TX_ACTION_S_JOIN_IN,
204 	[MRP_APPLICANT_VN] = MRP_TX_ACTION_S_NEW,
205 	[MRP_APPLICANT_AN] = MRP_TX_ACTION_S_NEW,
206 	[MRP_APPLICANT_AA] = MRP_TX_ACTION_S_JOIN_IN,
207 	[MRP_APPLICANT_QA] = MRP_TX_ACTION_S_JOIN_IN_OPTIONAL,
208 	[MRP_APPLICANT_LA] = MRP_TX_ACTION_S_LV,
209 	[MRP_APPLICANT_AO] = MRP_TX_ACTION_S_IN_OPTIONAL,
210 	[MRP_APPLICANT_QO] = MRP_TX_ACTION_S_IN_OPTIONAL,
211 	[MRP_APPLICANT_AP] = MRP_TX_ACTION_S_JOIN_IN,
212 	[MRP_APPLICANT_QP] = MRP_TX_ACTION_S_IN_OPTIONAL,
213 };
214 
215 static void mrp_attrvalue_inc(void *value, u8 len)
216 {
217 	u8 *v = (u8 *)value;
218 
219 	/* Add 1 to the last byte. If it becomes zero,
220 	 * go to the previous byte and repeat.
221 	 */
222 	while (len > 0 && !++v[--len])
223 		;
224 }
225 
226 static int mrp_attr_cmp(const struct mrp_attr *attr,
227 			 const void *value, u8 len, u8 type)
228 {
229 	if (attr->type != type)
230 		return attr->type - type;
231 	if (attr->len != len)
232 		return attr->len - len;
233 	return memcmp(attr->value, value, len);
234 }
235 
236 static struct mrp_attr *mrp_attr_lookup(const struct mrp_applicant *app,
237 					const void *value, u8 len, u8 type)
238 {
239 	struct rb_node *parent = app->mad.rb_node;
240 	struct mrp_attr *attr;
241 	int d;
242 
243 	while (parent) {
244 		attr = rb_entry(parent, struct mrp_attr, node);
245 		d = mrp_attr_cmp(attr, value, len, type);
246 		if (d > 0)
247 			parent = parent->rb_left;
248 		else if (d < 0)
249 			parent = parent->rb_right;
250 		else
251 			return attr;
252 	}
253 	return NULL;
254 }
255 
256 static struct mrp_attr *mrp_attr_create(struct mrp_applicant *app,
257 					const void *value, u8 len, u8 type)
258 {
259 	struct rb_node *parent = NULL, **p = &app->mad.rb_node;
260 	struct mrp_attr *attr;
261 	int d;
262 
263 	while (*p) {
264 		parent = *p;
265 		attr = rb_entry(parent, struct mrp_attr, node);
266 		d = mrp_attr_cmp(attr, value, len, type);
267 		if (d > 0)
268 			p = &parent->rb_left;
269 		else if (d < 0)
270 			p = &parent->rb_right;
271 		else {
272 			/* The attribute already exists; re-use it. */
273 			return attr;
274 		}
275 	}
276 	attr = kmalloc(sizeof(*attr) + len, GFP_ATOMIC);
277 	if (!attr)
278 		return attr;
279 	attr->state = MRP_APPLICANT_VO;
280 	attr->type  = type;
281 	attr->len   = len;
282 	memcpy(attr->value, value, len);
283 
284 	rb_link_node(&attr->node, parent, p);
285 	rb_insert_color(&attr->node, &app->mad);
286 	return attr;
287 }
288 
289 static void mrp_attr_destroy(struct mrp_applicant *app, struct mrp_attr *attr)
290 {
291 	rb_erase(&attr->node, &app->mad);
292 	kfree(attr);
293 }
294 
295 static int mrp_pdu_init(struct mrp_applicant *app)
296 {
297 	struct sk_buff *skb;
298 	struct mrp_pdu_hdr *ph;
299 
300 	skb = alloc_skb(app->dev->mtu + LL_RESERVED_SPACE(app->dev),
301 			GFP_ATOMIC);
302 	if (!skb)
303 		return -ENOMEM;
304 
305 	skb->dev = app->dev;
306 	skb->protocol = app->app->pkttype.type;
307 	skb_reserve(skb, LL_RESERVED_SPACE(app->dev));
308 	skb_reset_network_header(skb);
309 	skb_reset_transport_header(skb);
310 
311 	ph = __skb_put(skb, sizeof(*ph));
312 	ph->version = app->app->version;
313 
314 	app->pdu = skb;
315 	return 0;
316 }
317 
318 static int mrp_pdu_append_end_mark(struct mrp_applicant *app)
319 {
320 	__be16 *endmark;
321 
322 	if (skb_tailroom(app->pdu) < sizeof(*endmark))
323 		return -1;
324 	endmark = __skb_put(app->pdu, sizeof(*endmark));
325 	put_unaligned(MRP_END_MARK, endmark);
326 	return 0;
327 }
328 
329 static void mrp_pdu_queue(struct mrp_applicant *app)
330 {
331 	if (!app->pdu)
332 		return;
333 
334 	if (mrp_cb(app->pdu)->mh)
335 		mrp_pdu_append_end_mark(app);
336 	mrp_pdu_append_end_mark(app);
337 
338 	dev_hard_header(app->pdu, app->dev, ntohs(app->app->pkttype.type),
339 			app->app->group_address, app->dev->dev_addr,
340 			app->pdu->len);
341 
342 	skb_queue_tail(&app->queue, app->pdu);
343 	app->pdu = NULL;
344 }
345 
346 static void mrp_queue_xmit(struct mrp_applicant *app)
347 {
348 	struct sk_buff *skb;
349 
350 	while ((skb = skb_dequeue(&app->queue)))
351 		dev_queue_xmit(skb);
352 }
353 
354 static int mrp_pdu_append_msg_hdr(struct mrp_applicant *app,
355 				  u8 attrtype, u8 attrlen)
356 {
357 	struct mrp_msg_hdr *mh;
358 
359 	if (mrp_cb(app->pdu)->mh) {
360 		if (mrp_pdu_append_end_mark(app) < 0)
361 			return -1;
362 		mrp_cb(app->pdu)->mh = NULL;
363 		mrp_cb(app->pdu)->vah = NULL;
364 	}
365 
366 	if (skb_tailroom(app->pdu) < sizeof(*mh))
367 		return -1;
368 	mh = __skb_put(app->pdu, sizeof(*mh));
369 	mh->attrtype = attrtype;
370 	mh->attrlen = attrlen;
371 	mrp_cb(app->pdu)->mh = mh;
372 	return 0;
373 }
374 
375 static int mrp_pdu_append_vecattr_hdr(struct mrp_applicant *app,
376 				      const void *firstattrvalue, u8 attrlen)
377 {
378 	struct mrp_vecattr_hdr *vah;
379 
380 	if (skb_tailroom(app->pdu) < sizeof(*vah) + attrlen)
381 		return -1;
382 	vah = __skb_put(app->pdu, sizeof(*vah) + attrlen);
383 	put_unaligned(0, &vah->lenflags);
384 	memcpy(vah->firstattrvalue, firstattrvalue, attrlen);
385 	mrp_cb(app->pdu)->vah = vah;
386 	memcpy(mrp_cb(app->pdu)->attrvalue, firstattrvalue, attrlen);
387 	return 0;
388 }
389 
390 static int mrp_pdu_append_vecattr_event(struct mrp_applicant *app,
391 					const struct mrp_attr *attr,
392 					enum mrp_vecattr_event vaevent)
393 {
394 	u16 len, pos;
395 	u8 *vaevents;
396 	int err;
397 again:
398 	if (!app->pdu) {
399 		err = mrp_pdu_init(app);
400 		if (err < 0)
401 			return err;
402 	}
403 
404 	/* If there is no Message header in the PDU, or the Message header is
405 	 * for a different attribute type, add an EndMark (if necessary) and a
406 	 * new Message header to the PDU.
407 	 */
408 	if (!mrp_cb(app->pdu)->mh ||
409 	    mrp_cb(app->pdu)->mh->attrtype != attr->type ||
410 	    mrp_cb(app->pdu)->mh->attrlen != attr->len) {
411 		if (mrp_pdu_append_msg_hdr(app, attr->type, attr->len) < 0)
412 			goto queue;
413 	}
414 
415 	/* If there is no VectorAttribute header for this Message in the PDU,
416 	 * or this attribute's value does not sequentially follow the previous
417 	 * attribute's value, add a new VectorAttribute header to the PDU.
418 	 */
419 	if (!mrp_cb(app->pdu)->vah ||
420 	    memcmp(mrp_cb(app->pdu)->attrvalue, attr->value, attr->len)) {
421 		if (mrp_pdu_append_vecattr_hdr(app, attr->value, attr->len) < 0)
422 			goto queue;
423 	}
424 
425 	len = be16_to_cpu(get_unaligned(&mrp_cb(app->pdu)->vah->lenflags));
426 	pos = len % 3;
427 
428 	/* Events are packed into Vectors in the PDU, three to a byte. Add a
429 	 * byte to the end of the Vector if necessary.
430 	 */
431 	if (!pos) {
432 		if (skb_tailroom(app->pdu) < sizeof(u8))
433 			goto queue;
434 		vaevents = __skb_put(app->pdu, sizeof(u8));
435 	} else {
436 		vaevents = (u8 *)(skb_tail_pointer(app->pdu) - sizeof(u8));
437 	}
438 
439 	switch (pos) {
440 	case 0:
441 		*vaevents = vaevent * (__MRP_VECATTR_EVENT_MAX *
442 				       __MRP_VECATTR_EVENT_MAX);
443 		break;
444 	case 1:
445 		*vaevents += vaevent * __MRP_VECATTR_EVENT_MAX;
446 		break;
447 	case 2:
448 		*vaevents += vaevent;
449 		break;
450 	default:
451 		WARN_ON(1);
452 	}
453 
454 	/* Increment the length of the VectorAttribute in the PDU, as well as
455 	 * the value of the next attribute that would continue its Vector.
456 	 */
457 	put_unaligned(cpu_to_be16(++len), &mrp_cb(app->pdu)->vah->lenflags);
458 	mrp_attrvalue_inc(mrp_cb(app->pdu)->attrvalue, attr->len);
459 
460 	return 0;
461 
462 queue:
463 	mrp_pdu_queue(app);
464 	goto again;
465 }
466 
467 static void mrp_attr_event(struct mrp_applicant *app,
468 			   struct mrp_attr *attr, enum mrp_event event)
469 {
470 	enum mrp_applicant_state state;
471 
472 	state = mrp_applicant_state_table[attr->state][event];
473 	if (state == MRP_APPLICANT_INVALID) {
474 		WARN_ON(1);
475 		return;
476 	}
477 
478 	if (event == MRP_EVENT_TX) {
479 		/* When appending the attribute fails, don't update its state
480 		 * in order to retry at the next TX event.
481 		 */
482 
483 		switch (mrp_tx_action_table[attr->state]) {
484 		case MRP_TX_ACTION_NONE:
485 		case MRP_TX_ACTION_S_JOIN_IN_OPTIONAL:
486 		case MRP_TX_ACTION_S_IN_OPTIONAL:
487 			break;
488 		case MRP_TX_ACTION_S_NEW:
489 			if (mrp_pdu_append_vecattr_event(
490 				    app, attr, MRP_VECATTR_EVENT_NEW) < 0)
491 				return;
492 			break;
493 		case MRP_TX_ACTION_S_JOIN_IN:
494 			if (mrp_pdu_append_vecattr_event(
495 				    app, attr, MRP_VECATTR_EVENT_JOIN_IN) < 0)
496 				return;
497 			break;
498 		case MRP_TX_ACTION_S_LV:
499 			if (mrp_pdu_append_vecattr_event(
500 				    app, attr, MRP_VECATTR_EVENT_LV) < 0)
501 				return;
502 			/* As a pure applicant, sending a leave message
503 			 * implies that the attribute was unregistered and
504 			 * can be destroyed.
505 			 */
506 			mrp_attr_destroy(app, attr);
507 			return;
508 		default:
509 			WARN_ON(1);
510 		}
511 	}
512 
513 	attr->state = state;
514 }
515 
516 int mrp_request_join(const struct net_device *dev,
517 		     const struct mrp_application *appl,
518 		     const void *value, u8 len, u8 type)
519 {
520 	struct mrp_port *port = rtnl_dereference(dev->mrp_port);
521 	struct mrp_applicant *app = rtnl_dereference(
522 		port->applicants[appl->type]);
523 	struct mrp_attr *attr;
524 
525 	if (sizeof(struct mrp_skb_cb) + len >
526 	    FIELD_SIZEOF(struct sk_buff, cb))
527 		return -ENOMEM;
528 
529 	spin_lock_bh(&app->lock);
530 	attr = mrp_attr_create(app, value, len, type);
531 	if (!attr) {
532 		spin_unlock_bh(&app->lock);
533 		return -ENOMEM;
534 	}
535 	mrp_attr_event(app, attr, MRP_EVENT_JOIN);
536 	spin_unlock_bh(&app->lock);
537 	return 0;
538 }
539 EXPORT_SYMBOL_GPL(mrp_request_join);
540 
541 void mrp_request_leave(const struct net_device *dev,
542 		       const struct mrp_application *appl,
543 		       const void *value, u8 len, u8 type)
544 {
545 	struct mrp_port *port = rtnl_dereference(dev->mrp_port);
546 	struct mrp_applicant *app = rtnl_dereference(
547 		port->applicants[appl->type]);
548 	struct mrp_attr *attr;
549 
550 	if (sizeof(struct mrp_skb_cb) + len >
551 	    FIELD_SIZEOF(struct sk_buff, cb))
552 		return;
553 
554 	spin_lock_bh(&app->lock);
555 	attr = mrp_attr_lookup(app, value, len, type);
556 	if (!attr) {
557 		spin_unlock_bh(&app->lock);
558 		return;
559 	}
560 	mrp_attr_event(app, attr, MRP_EVENT_LV);
561 	spin_unlock_bh(&app->lock);
562 }
563 EXPORT_SYMBOL_GPL(mrp_request_leave);
564 
565 static void mrp_mad_event(struct mrp_applicant *app, enum mrp_event event)
566 {
567 	struct rb_node *node, *next;
568 	struct mrp_attr *attr;
569 
570 	for (node = rb_first(&app->mad);
571 	     next = node ? rb_next(node) : NULL, node != NULL;
572 	     node = next) {
573 		attr = rb_entry(node, struct mrp_attr, node);
574 		mrp_attr_event(app, attr, event);
575 	}
576 }
577 
578 static void mrp_join_timer_arm(struct mrp_applicant *app)
579 {
580 	unsigned long delay;
581 
582 	delay = (u64)msecs_to_jiffies(mrp_join_time) * prandom_u32() >> 32;
583 	mod_timer(&app->join_timer, jiffies + delay);
584 }
585 
586 static void mrp_join_timer(struct timer_list *t)
587 {
588 	struct mrp_applicant *app = from_timer(app, t, join_timer);
589 
590 	spin_lock(&app->lock);
591 	mrp_mad_event(app, MRP_EVENT_TX);
592 	mrp_pdu_queue(app);
593 	spin_unlock(&app->lock);
594 
595 	mrp_queue_xmit(app);
596 	mrp_join_timer_arm(app);
597 }
598 
599 static void mrp_periodic_timer_arm(struct mrp_applicant *app)
600 {
601 	mod_timer(&app->periodic_timer,
602 		  jiffies + msecs_to_jiffies(mrp_periodic_time));
603 }
604 
605 static void mrp_periodic_timer(struct timer_list *t)
606 {
607 	struct mrp_applicant *app = from_timer(app, t, periodic_timer);
608 
609 	spin_lock(&app->lock);
610 	mrp_mad_event(app, MRP_EVENT_PERIODIC);
611 	mrp_pdu_queue(app);
612 	spin_unlock(&app->lock);
613 
614 	mrp_periodic_timer_arm(app);
615 }
616 
617 static int mrp_pdu_parse_end_mark(struct sk_buff *skb, int *offset)
618 {
619 	__be16 endmark;
620 
621 	if (skb_copy_bits(skb, *offset, &endmark, sizeof(endmark)) < 0)
622 		return -1;
623 	if (endmark == MRP_END_MARK) {
624 		*offset += sizeof(endmark);
625 		return -1;
626 	}
627 	return 0;
628 }
629 
630 static void mrp_pdu_parse_vecattr_event(struct mrp_applicant *app,
631 					struct sk_buff *skb,
632 					enum mrp_vecattr_event vaevent)
633 {
634 	struct mrp_attr *attr;
635 	enum mrp_event event;
636 
637 	attr = mrp_attr_lookup(app, mrp_cb(skb)->attrvalue,
638 			       mrp_cb(skb)->mh->attrlen,
639 			       mrp_cb(skb)->mh->attrtype);
640 	if (attr == NULL)
641 		return;
642 
643 	switch (vaevent) {
644 	case MRP_VECATTR_EVENT_NEW:
645 		event = MRP_EVENT_R_NEW;
646 		break;
647 	case MRP_VECATTR_EVENT_JOIN_IN:
648 		event = MRP_EVENT_R_JOIN_IN;
649 		break;
650 	case MRP_VECATTR_EVENT_IN:
651 		event = MRP_EVENT_R_IN;
652 		break;
653 	case MRP_VECATTR_EVENT_JOIN_MT:
654 		event = MRP_EVENT_R_JOIN_MT;
655 		break;
656 	case MRP_VECATTR_EVENT_MT:
657 		event = MRP_EVENT_R_MT;
658 		break;
659 	case MRP_VECATTR_EVENT_LV:
660 		event = MRP_EVENT_R_LV;
661 		break;
662 	default:
663 		return;
664 	}
665 
666 	mrp_attr_event(app, attr, event);
667 }
668 
669 static int mrp_pdu_parse_vecattr(struct mrp_applicant *app,
670 				 struct sk_buff *skb, int *offset)
671 {
672 	struct mrp_vecattr_hdr _vah;
673 	u16 valen;
674 	u8 vaevents, vaevent;
675 
676 	mrp_cb(skb)->vah = skb_header_pointer(skb, *offset, sizeof(_vah),
677 					      &_vah);
678 	if (!mrp_cb(skb)->vah)
679 		return -1;
680 	*offset += sizeof(_vah);
681 
682 	if (get_unaligned(&mrp_cb(skb)->vah->lenflags) &
683 	    MRP_VECATTR_HDR_FLAG_LA)
684 		mrp_mad_event(app, MRP_EVENT_R_LA);
685 	valen = be16_to_cpu(get_unaligned(&mrp_cb(skb)->vah->lenflags) &
686 			    MRP_VECATTR_HDR_LEN_MASK);
687 
688 	/* The VectorAttribute structure in a PDU carries event information
689 	 * about one or more attributes having consecutive values. Only the
690 	 * value for the first attribute is contained in the structure. So
691 	 * we make a copy of that value, and then increment it each time we
692 	 * advance to the next event in its Vector.
693 	 */
694 	if (sizeof(struct mrp_skb_cb) + mrp_cb(skb)->mh->attrlen >
695 	    FIELD_SIZEOF(struct sk_buff, cb))
696 		return -1;
697 	if (skb_copy_bits(skb, *offset, mrp_cb(skb)->attrvalue,
698 			  mrp_cb(skb)->mh->attrlen) < 0)
699 		return -1;
700 	*offset += mrp_cb(skb)->mh->attrlen;
701 
702 	/* In a VectorAttribute, the Vector contains events which are packed
703 	 * three to a byte. We process one byte of the Vector at a time.
704 	 */
705 	while (valen > 0) {
706 		if (skb_copy_bits(skb, *offset, &vaevents,
707 				  sizeof(vaevents)) < 0)
708 			return -1;
709 		*offset += sizeof(vaevents);
710 
711 		/* Extract and process the first event. */
712 		vaevent = vaevents / (__MRP_VECATTR_EVENT_MAX *
713 				      __MRP_VECATTR_EVENT_MAX);
714 		if (vaevent >= __MRP_VECATTR_EVENT_MAX) {
715 			/* The byte is malformed; stop processing. */
716 			return -1;
717 		}
718 		mrp_pdu_parse_vecattr_event(app, skb, vaevent);
719 
720 		/* If present, extract and process the second event. */
721 		if (!--valen)
722 			break;
723 		mrp_attrvalue_inc(mrp_cb(skb)->attrvalue,
724 				  mrp_cb(skb)->mh->attrlen);
725 		vaevents %= (__MRP_VECATTR_EVENT_MAX *
726 			     __MRP_VECATTR_EVENT_MAX);
727 		vaevent = vaevents / __MRP_VECATTR_EVENT_MAX;
728 		mrp_pdu_parse_vecattr_event(app, skb, vaevent);
729 
730 		/* If present, extract and process the third event. */
731 		if (!--valen)
732 			break;
733 		mrp_attrvalue_inc(mrp_cb(skb)->attrvalue,
734 				  mrp_cb(skb)->mh->attrlen);
735 		vaevents %= __MRP_VECATTR_EVENT_MAX;
736 		vaevent = vaevents;
737 		mrp_pdu_parse_vecattr_event(app, skb, vaevent);
738 	}
739 	return 0;
740 }
741 
742 static int mrp_pdu_parse_msg(struct mrp_applicant *app, struct sk_buff *skb,
743 			     int *offset)
744 {
745 	struct mrp_msg_hdr _mh;
746 
747 	mrp_cb(skb)->mh = skb_header_pointer(skb, *offset, sizeof(_mh), &_mh);
748 	if (!mrp_cb(skb)->mh)
749 		return -1;
750 	*offset += sizeof(_mh);
751 
752 	if (mrp_cb(skb)->mh->attrtype == 0 ||
753 	    mrp_cb(skb)->mh->attrtype > app->app->maxattr ||
754 	    mrp_cb(skb)->mh->attrlen == 0)
755 		return -1;
756 
757 	while (skb->len > *offset) {
758 		if (mrp_pdu_parse_end_mark(skb, offset) < 0)
759 			break;
760 		if (mrp_pdu_parse_vecattr(app, skb, offset) < 0)
761 			return -1;
762 	}
763 	return 0;
764 }
765 
766 static int mrp_rcv(struct sk_buff *skb, struct net_device *dev,
767 		   struct packet_type *pt, struct net_device *orig_dev)
768 {
769 	struct mrp_application *appl = container_of(pt, struct mrp_application,
770 						    pkttype);
771 	struct mrp_port *port;
772 	struct mrp_applicant *app;
773 	struct mrp_pdu_hdr _ph;
774 	const struct mrp_pdu_hdr *ph;
775 	int offset = skb_network_offset(skb);
776 
777 	/* If the interface is in promiscuous mode, drop the packet if
778 	 * it was unicast to another host.
779 	 */
780 	if (unlikely(skb->pkt_type == PACKET_OTHERHOST))
781 		goto out;
782 	skb = skb_share_check(skb, GFP_ATOMIC);
783 	if (unlikely(!skb))
784 		goto out;
785 	port = rcu_dereference(dev->mrp_port);
786 	if (unlikely(!port))
787 		goto out;
788 	app = rcu_dereference(port->applicants[appl->type]);
789 	if (unlikely(!app))
790 		goto out;
791 
792 	ph = skb_header_pointer(skb, offset, sizeof(_ph), &_ph);
793 	if (!ph)
794 		goto out;
795 	offset += sizeof(_ph);
796 
797 	if (ph->version != app->app->version)
798 		goto out;
799 
800 	spin_lock(&app->lock);
801 	while (skb->len > offset) {
802 		if (mrp_pdu_parse_end_mark(skb, &offset) < 0)
803 			break;
804 		if (mrp_pdu_parse_msg(app, skb, &offset) < 0)
805 			break;
806 	}
807 	spin_unlock(&app->lock);
808 out:
809 	kfree_skb(skb);
810 	return 0;
811 }
812 
813 static int mrp_init_port(struct net_device *dev)
814 {
815 	struct mrp_port *port;
816 
817 	port = kzalloc(sizeof(*port), GFP_KERNEL);
818 	if (!port)
819 		return -ENOMEM;
820 	rcu_assign_pointer(dev->mrp_port, port);
821 	return 0;
822 }
823 
824 static void mrp_release_port(struct net_device *dev)
825 {
826 	struct mrp_port *port = rtnl_dereference(dev->mrp_port);
827 	unsigned int i;
828 
829 	for (i = 0; i <= MRP_APPLICATION_MAX; i++) {
830 		if (rtnl_dereference(port->applicants[i]))
831 			return;
832 	}
833 	RCU_INIT_POINTER(dev->mrp_port, NULL);
834 	kfree_rcu(port, rcu);
835 }
836 
837 int mrp_init_applicant(struct net_device *dev, struct mrp_application *appl)
838 {
839 	struct mrp_applicant *app;
840 	int err;
841 
842 	ASSERT_RTNL();
843 
844 	if (!rtnl_dereference(dev->mrp_port)) {
845 		err = mrp_init_port(dev);
846 		if (err < 0)
847 			goto err1;
848 	}
849 
850 	err = -ENOMEM;
851 	app = kzalloc(sizeof(*app), GFP_KERNEL);
852 	if (!app)
853 		goto err2;
854 
855 	err = dev_mc_add(dev, appl->group_address);
856 	if (err < 0)
857 		goto err3;
858 
859 	app->dev = dev;
860 	app->app = appl;
861 	app->mad = RB_ROOT;
862 	spin_lock_init(&app->lock);
863 	skb_queue_head_init(&app->queue);
864 	rcu_assign_pointer(dev->mrp_port->applicants[appl->type], app);
865 	timer_setup(&app->join_timer, mrp_join_timer, 0);
866 	mrp_join_timer_arm(app);
867 	timer_setup(&app->periodic_timer, mrp_periodic_timer, 0);
868 	mrp_periodic_timer_arm(app);
869 	return 0;
870 
871 err3:
872 	kfree(app);
873 err2:
874 	mrp_release_port(dev);
875 err1:
876 	return err;
877 }
878 EXPORT_SYMBOL_GPL(mrp_init_applicant);
879 
880 void mrp_uninit_applicant(struct net_device *dev, struct mrp_application *appl)
881 {
882 	struct mrp_port *port = rtnl_dereference(dev->mrp_port);
883 	struct mrp_applicant *app = rtnl_dereference(
884 		port->applicants[appl->type]);
885 
886 	ASSERT_RTNL();
887 
888 	RCU_INIT_POINTER(port->applicants[appl->type], NULL);
889 
890 	/* Delete timer and generate a final TX event to flush out
891 	 * all pending messages before the applicant is gone.
892 	 */
893 	del_timer_sync(&app->join_timer);
894 	del_timer_sync(&app->periodic_timer);
895 
896 	spin_lock_bh(&app->lock);
897 	mrp_mad_event(app, MRP_EVENT_TX);
898 	mrp_pdu_queue(app);
899 	spin_unlock_bh(&app->lock);
900 
901 	mrp_queue_xmit(app);
902 
903 	dev_mc_del(dev, appl->group_address);
904 	kfree_rcu(app, rcu);
905 	mrp_release_port(dev);
906 }
907 EXPORT_SYMBOL_GPL(mrp_uninit_applicant);
908 
909 int mrp_register_application(struct mrp_application *appl)
910 {
911 	appl->pkttype.func = mrp_rcv;
912 	dev_add_pack(&appl->pkttype);
913 	return 0;
914 }
915 EXPORT_SYMBOL_GPL(mrp_register_application);
916 
917 void mrp_unregister_application(struct mrp_application *appl)
918 {
919 	dev_remove_pack(&appl->pkttype);
920 }
921 EXPORT_SYMBOL_GPL(mrp_unregister_application);
922