xref: /linux/net/802/mrp.c (revision 9fe34f5d)
1 /*
2  *	IEEE 802.1Q Multiple Registration Protocol (MRP)
3  *
4  *	Copyright (c) 2012 Massachusetts Institute of Technology
5  *
6  *	Adapted from code in net/802/garp.c
7  *	Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
8  *
9  *	This program is free software; you can redistribute it and/or
10  *	modify it under the terms of the GNU General Public License
11  *	version 2 as published by the Free Software Foundation.
12  */
13 #include <linux/kernel.h>
14 #include <linux/timer.h>
15 #include <linux/skbuff.h>
16 #include <linux/netdevice.h>
17 #include <linux/etherdevice.h>
18 #include <linux/rtnetlink.h>
19 #include <linux/slab.h>
20 #include <linux/module.h>
21 #include <net/mrp.h>
22 #include <asm/unaligned.h>
23 
24 static unsigned int mrp_join_time __read_mostly = 200;
25 module_param(mrp_join_time, uint, 0644);
26 MODULE_PARM_DESC(mrp_join_time, "Join time in ms (default 200ms)");
27 
28 static unsigned int mrp_periodic_time __read_mostly = 1000;
29 module_param(mrp_periodic_time, uint, 0644);
30 MODULE_PARM_DESC(mrp_periodic_time, "Periodic time in ms (default 1s)");
31 
32 MODULE_LICENSE("GPL");
33 
34 static const u8
35 mrp_applicant_state_table[MRP_APPLICANT_MAX + 1][MRP_EVENT_MAX + 1] = {
36 	[MRP_APPLICANT_VO] = {
37 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
38 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_VP,
39 		[MRP_EVENT_LV]		= MRP_APPLICANT_VO,
40 		[MRP_EVENT_TX]		= MRP_APPLICANT_VO,
41 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_VO,
42 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_AO,
43 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_VO,
44 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_VO,
45 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_VO,
46 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VO,
47 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VO,
48 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VO,
49 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_VO,
50 	},
51 	[MRP_APPLICANT_VP] = {
52 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
53 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_VP,
54 		[MRP_EVENT_LV]		= MRP_APPLICANT_VO,
55 		[MRP_EVENT_TX]		= MRP_APPLICANT_AA,
56 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_VP,
57 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_AP,
58 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_VP,
59 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_VP,
60 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_VP,
61 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VP,
62 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VP,
63 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VP,
64 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_VP,
65 	},
66 	[MRP_APPLICANT_VN] = {
67 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
68 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_VN,
69 		[MRP_EVENT_LV]		= MRP_APPLICANT_LA,
70 		[MRP_EVENT_TX]		= MRP_APPLICANT_AN,
71 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_VN,
72 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_VN,
73 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_VN,
74 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_VN,
75 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_VN,
76 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VN,
77 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VN,
78 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VN,
79 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_VN,
80 	},
81 	[MRP_APPLICANT_AN] = {
82 		[MRP_EVENT_NEW]		= MRP_APPLICANT_AN,
83 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_AN,
84 		[MRP_EVENT_LV]		= MRP_APPLICANT_LA,
85 		[MRP_EVENT_TX]		= MRP_APPLICANT_QA,
86 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_AN,
87 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_AN,
88 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_AN,
89 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AN,
90 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AN,
91 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VN,
92 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VN,
93 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VN,
94 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AN,
95 	},
96 	[MRP_APPLICANT_AA] = {
97 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
98 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_AA,
99 		[MRP_EVENT_LV]		= MRP_APPLICANT_LA,
100 		[MRP_EVENT_TX]		= MRP_APPLICANT_QA,
101 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_AA,
102 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QA,
103 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_AA,
104 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AA,
105 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AA,
106 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VP,
107 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VP,
108 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VP,
109 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AA,
110 	},
111 	[MRP_APPLICANT_QA] = {
112 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
113 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_QA,
114 		[MRP_EVENT_LV]		= MRP_APPLICANT_LA,
115 		[MRP_EVENT_TX]		= MRP_APPLICANT_QA,
116 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_QA,
117 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QA,
118 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_QA,
119 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AA,
120 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AA,
121 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VP,
122 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VP,
123 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VP,
124 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AA,
125 	},
126 	[MRP_APPLICANT_LA] = {
127 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
128 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_AA,
129 		[MRP_EVENT_LV]		= MRP_APPLICANT_LA,
130 		[MRP_EVENT_TX]		= MRP_APPLICANT_VO,
131 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_LA,
132 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_LA,
133 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_LA,
134 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_LA,
135 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_LA,
136 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_LA,
137 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_LA,
138 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_LA,
139 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_LA,
140 	},
141 	[MRP_APPLICANT_AO] = {
142 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
143 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_AP,
144 		[MRP_EVENT_LV]		= MRP_APPLICANT_AO,
145 		[MRP_EVENT_TX]		= MRP_APPLICANT_AO,
146 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_AO,
147 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QO,
148 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_AO,
149 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AO,
150 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AO,
151 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VO,
152 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VO,
153 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VO,
154 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AO,
155 	},
156 	[MRP_APPLICANT_QO] = {
157 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
158 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_QP,
159 		[MRP_EVENT_LV]		= MRP_APPLICANT_QO,
160 		[MRP_EVENT_TX]		= MRP_APPLICANT_QO,
161 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_QO,
162 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QO,
163 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_QO,
164 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AO,
165 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AO,
166 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VO,
167 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VO,
168 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VO,
169 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_QO,
170 	},
171 	[MRP_APPLICANT_AP] = {
172 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
173 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_AP,
174 		[MRP_EVENT_LV]		= MRP_APPLICANT_AO,
175 		[MRP_EVENT_TX]		= MRP_APPLICANT_QA,
176 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_AP,
177 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QP,
178 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_AP,
179 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AP,
180 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AP,
181 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VP,
182 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VP,
183 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VP,
184 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AP,
185 	},
186 	[MRP_APPLICANT_QP] = {
187 		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
188 		[MRP_EVENT_JOIN]	= MRP_APPLICANT_QP,
189 		[MRP_EVENT_LV]		= MRP_APPLICANT_QO,
190 		[MRP_EVENT_TX]		= MRP_APPLICANT_QP,
191 		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_QP,
192 		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QP,
193 		[MRP_EVENT_R_IN]	= MRP_APPLICANT_QP,
194 		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AP,
195 		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AP,
196 		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VP,
197 		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VP,
198 		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VP,
199 		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AP,
200 	},
201 };
202 
203 static const u8
204 mrp_tx_action_table[MRP_APPLICANT_MAX + 1] = {
205 	[MRP_APPLICANT_VO] = MRP_TX_ACTION_S_IN_OPTIONAL,
206 	[MRP_APPLICANT_VP] = MRP_TX_ACTION_S_JOIN_IN,
207 	[MRP_APPLICANT_VN] = MRP_TX_ACTION_S_NEW,
208 	[MRP_APPLICANT_AN] = MRP_TX_ACTION_S_NEW,
209 	[MRP_APPLICANT_AA] = MRP_TX_ACTION_S_JOIN_IN,
210 	[MRP_APPLICANT_QA] = MRP_TX_ACTION_S_JOIN_IN_OPTIONAL,
211 	[MRP_APPLICANT_LA] = MRP_TX_ACTION_S_LV,
212 	[MRP_APPLICANT_AO] = MRP_TX_ACTION_S_IN_OPTIONAL,
213 	[MRP_APPLICANT_QO] = MRP_TX_ACTION_S_IN_OPTIONAL,
214 	[MRP_APPLICANT_AP] = MRP_TX_ACTION_S_JOIN_IN,
215 	[MRP_APPLICANT_QP] = MRP_TX_ACTION_S_IN_OPTIONAL,
216 };
217 
218 static void mrp_attrvalue_inc(void *value, u8 len)
219 {
220 	u8 *v = (u8 *)value;
221 
222 	/* Add 1 to the last byte. If it becomes zero,
223 	 * go to the previous byte and repeat.
224 	 */
225 	while (len > 0 && !++v[--len])
226 		;
227 }
228 
229 static int mrp_attr_cmp(const struct mrp_attr *attr,
230 			 const void *value, u8 len, u8 type)
231 {
232 	if (attr->type != type)
233 		return attr->type - type;
234 	if (attr->len != len)
235 		return attr->len - len;
236 	return memcmp(attr->value, value, len);
237 }
238 
239 static struct mrp_attr *mrp_attr_lookup(const struct mrp_applicant *app,
240 					const void *value, u8 len, u8 type)
241 {
242 	struct rb_node *parent = app->mad.rb_node;
243 	struct mrp_attr *attr;
244 	int d;
245 
246 	while (parent) {
247 		attr = rb_entry(parent, struct mrp_attr, node);
248 		d = mrp_attr_cmp(attr, value, len, type);
249 		if (d > 0)
250 			parent = parent->rb_left;
251 		else if (d < 0)
252 			parent = parent->rb_right;
253 		else
254 			return attr;
255 	}
256 	return NULL;
257 }
258 
259 static struct mrp_attr *mrp_attr_create(struct mrp_applicant *app,
260 					const void *value, u8 len, u8 type)
261 {
262 	struct rb_node *parent = NULL, **p = &app->mad.rb_node;
263 	struct mrp_attr *attr;
264 	int d;
265 
266 	while (*p) {
267 		parent = *p;
268 		attr = rb_entry(parent, struct mrp_attr, node);
269 		d = mrp_attr_cmp(attr, value, len, type);
270 		if (d > 0)
271 			p = &parent->rb_left;
272 		else if (d < 0)
273 			p = &parent->rb_right;
274 		else {
275 			/* The attribute already exists; re-use it. */
276 			return attr;
277 		}
278 	}
279 	attr = kmalloc(sizeof(*attr) + len, GFP_ATOMIC);
280 	if (!attr)
281 		return attr;
282 	attr->state = MRP_APPLICANT_VO;
283 	attr->type  = type;
284 	attr->len   = len;
285 	memcpy(attr->value, value, len);
286 
287 	rb_link_node(&attr->node, parent, p);
288 	rb_insert_color(&attr->node, &app->mad);
289 	return attr;
290 }
291 
292 static void mrp_attr_destroy(struct mrp_applicant *app, struct mrp_attr *attr)
293 {
294 	rb_erase(&attr->node, &app->mad);
295 	kfree(attr);
296 }
297 
298 static int mrp_pdu_init(struct mrp_applicant *app)
299 {
300 	struct sk_buff *skb;
301 	struct mrp_pdu_hdr *ph;
302 
303 	skb = alloc_skb(app->dev->mtu + LL_RESERVED_SPACE(app->dev),
304 			GFP_ATOMIC);
305 	if (!skb)
306 		return -ENOMEM;
307 
308 	skb->dev = app->dev;
309 	skb->protocol = app->app->pkttype.type;
310 	skb_reserve(skb, LL_RESERVED_SPACE(app->dev));
311 	skb_reset_network_header(skb);
312 	skb_reset_transport_header(skb);
313 
314 	ph = (struct mrp_pdu_hdr *)__skb_put(skb, sizeof(*ph));
315 	ph->version = app->app->version;
316 
317 	app->pdu = skb;
318 	return 0;
319 }
320 
321 static int mrp_pdu_append_end_mark(struct mrp_applicant *app)
322 {
323 	__be16 *endmark;
324 
325 	if (skb_tailroom(app->pdu) < sizeof(*endmark))
326 		return -1;
327 	endmark = (__be16 *)__skb_put(app->pdu, sizeof(*endmark));
328 	put_unaligned(MRP_END_MARK, endmark);
329 	return 0;
330 }
331 
332 static void mrp_pdu_queue(struct mrp_applicant *app)
333 {
334 	if (!app->pdu)
335 		return;
336 
337 	if (mrp_cb(app->pdu)->mh)
338 		mrp_pdu_append_end_mark(app);
339 	mrp_pdu_append_end_mark(app);
340 
341 	dev_hard_header(app->pdu, app->dev, ntohs(app->app->pkttype.type),
342 			app->app->group_address, app->dev->dev_addr,
343 			app->pdu->len);
344 
345 	skb_queue_tail(&app->queue, app->pdu);
346 	app->pdu = NULL;
347 }
348 
349 static void mrp_queue_xmit(struct mrp_applicant *app)
350 {
351 	struct sk_buff *skb;
352 
353 	while ((skb = skb_dequeue(&app->queue)))
354 		dev_queue_xmit(skb);
355 }
356 
357 static int mrp_pdu_append_msg_hdr(struct mrp_applicant *app,
358 				  u8 attrtype, u8 attrlen)
359 {
360 	struct mrp_msg_hdr *mh;
361 
362 	if (mrp_cb(app->pdu)->mh) {
363 		if (mrp_pdu_append_end_mark(app) < 0)
364 			return -1;
365 		mrp_cb(app->pdu)->mh = NULL;
366 		mrp_cb(app->pdu)->vah = NULL;
367 	}
368 
369 	if (skb_tailroom(app->pdu) < sizeof(*mh))
370 		return -1;
371 	mh = (struct mrp_msg_hdr *)__skb_put(app->pdu, sizeof(*mh));
372 	mh->attrtype = attrtype;
373 	mh->attrlen = attrlen;
374 	mrp_cb(app->pdu)->mh = mh;
375 	return 0;
376 }
377 
378 static int mrp_pdu_append_vecattr_hdr(struct mrp_applicant *app,
379 				      const void *firstattrvalue, u8 attrlen)
380 {
381 	struct mrp_vecattr_hdr *vah;
382 
383 	if (skb_tailroom(app->pdu) < sizeof(*vah) + attrlen)
384 		return -1;
385 	vah = (struct mrp_vecattr_hdr *)__skb_put(app->pdu,
386 						  sizeof(*vah) + attrlen);
387 	put_unaligned(0, &vah->lenflags);
388 	memcpy(vah->firstattrvalue, firstattrvalue, attrlen);
389 	mrp_cb(app->pdu)->vah = vah;
390 	memcpy(mrp_cb(app->pdu)->attrvalue, firstattrvalue, attrlen);
391 	return 0;
392 }
393 
394 static int mrp_pdu_append_vecattr_event(struct mrp_applicant *app,
395 					const struct mrp_attr *attr,
396 					enum mrp_vecattr_event vaevent)
397 {
398 	u16 len, pos;
399 	u8 *vaevents;
400 	int err;
401 again:
402 	if (!app->pdu) {
403 		err = mrp_pdu_init(app);
404 		if (err < 0)
405 			return err;
406 	}
407 
408 	/* If there is no Message header in the PDU, or the Message header is
409 	 * for a different attribute type, add an EndMark (if necessary) and a
410 	 * new Message header to the PDU.
411 	 */
412 	if (!mrp_cb(app->pdu)->mh ||
413 	    mrp_cb(app->pdu)->mh->attrtype != attr->type ||
414 	    mrp_cb(app->pdu)->mh->attrlen != attr->len) {
415 		if (mrp_pdu_append_msg_hdr(app, attr->type, attr->len) < 0)
416 			goto queue;
417 	}
418 
419 	/* If there is no VectorAttribute header for this Message in the PDU,
420 	 * or this attribute's value does not sequentially follow the previous
421 	 * attribute's value, add a new VectorAttribute header to the PDU.
422 	 */
423 	if (!mrp_cb(app->pdu)->vah ||
424 	    memcmp(mrp_cb(app->pdu)->attrvalue, attr->value, attr->len)) {
425 		if (mrp_pdu_append_vecattr_hdr(app, attr->value, attr->len) < 0)
426 			goto queue;
427 	}
428 
429 	len = be16_to_cpu(get_unaligned(&mrp_cb(app->pdu)->vah->lenflags));
430 	pos = len % 3;
431 
432 	/* Events are packed into Vectors in the PDU, three to a byte. Add a
433 	 * byte to the end of the Vector if necessary.
434 	 */
435 	if (!pos) {
436 		if (skb_tailroom(app->pdu) < sizeof(u8))
437 			goto queue;
438 		vaevents = (u8 *)__skb_put(app->pdu, sizeof(u8));
439 	} else {
440 		vaevents = (u8 *)(skb_tail_pointer(app->pdu) - sizeof(u8));
441 	}
442 
443 	switch (pos) {
444 	case 0:
445 		*vaevents = vaevent * (__MRP_VECATTR_EVENT_MAX *
446 				       __MRP_VECATTR_EVENT_MAX);
447 		break;
448 	case 1:
449 		*vaevents += vaevent * __MRP_VECATTR_EVENT_MAX;
450 		break;
451 	case 2:
452 		*vaevents += vaevent;
453 		break;
454 	default:
455 		WARN_ON(1);
456 	}
457 
458 	/* Increment the length of the VectorAttribute in the PDU, as well as
459 	 * the value of the next attribute that would continue its Vector.
460 	 */
461 	put_unaligned(cpu_to_be16(++len), &mrp_cb(app->pdu)->vah->lenflags);
462 	mrp_attrvalue_inc(mrp_cb(app->pdu)->attrvalue, attr->len);
463 
464 	return 0;
465 
466 queue:
467 	mrp_pdu_queue(app);
468 	goto again;
469 }
470 
471 static void mrp_attr_event(struct mrp_applicant *app,
472 			   struct mrp_attr *attr, enum mrp_event event)
473 {
474 	enum mrp_applicant_state state;
475 
476 	state = mrp_applicant_state_table[attr->state][event];
477 	if (state == MRP_APPLICANT_INVALID) {
478 		WARN_ON(1);
479 		return;
480 	}
481 
482 	if (event == MRP_EVENT_TX) {
483 		/* When appending the attribute fails, don't update its state
484 		 * in order to retry at the next TX event.
485 		 */
486 
487 		switch (mrp_tx_action_table[attr->state]) {
488 		case MRP_TX_ACTION_NONE:
489 		case MRP_TX_ACTION_S_JOIN_IN_OPTIONAL:
490 		case MRP_TX_ACTION_S_IN_OPTIONAL:
491 			break;
492 		case MRP_TX_ACTION_S_NEW:
493 			if (mrp_pdu_append_vecattr_event(
494 				    app, attr, MRP_VECATTR_EVENT_NEW) < 0)
495 				return;
496 			break;
497 		case MRP_TX_ACTION_S_JOIN_IN:
498 			if (mrp_pdu_append_vecattr_event(
499 				    app, attr, MRP_VECATTR_EVENT_JOIN_IN) < 0)
500 				return;
501 			break;
502 		case MRP_TX_ACTION_S_LV:
503 			if (mrp_pdu_append_vecattr_event(
504 				    app, attr, MRP_VECATTR_EVENT_LV) < 0)
505 				return;
506 			/* As a pure applicant, sending a leave message
507 			 * implies that the attribute was unregistered and
508 			 * can be destroyed.
509 			 */
510 			mrp_attr_destroy(app, attr);
511 			return;
512 		default:
513 			WARN_ON(1);
514 		}
515 	}
516 
517 	attr->state = state;
518 }
519 
520 int mrp_request_join(const struct net_device *dev,
521 		     const struct mrp_application *appl,
522 		     const void *value, u8 len, u8 type)
523 {
524 	struct mrp_port *port = rtnl_dereference(dev->mrp_port);
525 	struct mrp_applicant *app = rtnl_dereference(
526 		port->applicants[appl->type]);
527 	struct mrp_attr *attr;
528 
529 	if (sizeof(struct mrp_skb_cb) + len >
530 	    FIELD_SIZEOF(struct sk_buff, cb))
531 		return -ENOMEM;
532 
533 	spin_lock_bh(&app->lock);
534 	attr = mrp_attr_create(app, value, len, type);
535 	if (!attr) {
536 		spin_unlock_bh(&app->lock);
537 		return -ENOMEM;
538 	}
539 	mrp_attr_event(app, attr, MRP_EVENT_JOIN);
540 	spin_unlock_bh(&app->lock);
541 	return 0;
542 }
543 EXPORT_SYMBOL_GPL(mrp_request_join);
544 
545 void mrp_request_leave(const struct net_device *dev,
546 		       const struct mrp_application *appl,
547 		       const void *value, u8 len, u8 type)
548 {
549 	struct mrp_port *port = rtnl_dereference(dev->mrp_port);
550 	struct mrp_applicant *app = rtnl_dereference(
551 		port->applicants[appl->type]);
552 	struct mrp_attr *attr;
553 
554 	if (sizeof(struct mrp_skb_cb) + len >
555 	    FIELD_SIZEOF(struct sk_buff, cb))
556 		return;
557 
558 	spin_lock_bh(&app->lock);
559 	attr = mrp_attr_lookup(app, value, len, type);
560 	if (!attr) {
561 		spin_unlock_bh(&app->lock);
562 		return;
563 	}
564 	mrp_attr_event(app, attr, MRP_EVENT_LV);
565 	spin_unlock_bh(&app->lock);
566 }
567 EXPORT_SYMBOL_GPL(mrp_request_leave);
568 
569 static void mrp_mad_event(struct mrp_applicant *app, enum mrp_event event)
570 {
571 	struct rb_node *node, *next;
572 	struct mrp_attr *attr;
573 
574 	for (node = rb_first(&app->mad);
575 	     next = node ? rb_next(node) : NULL, node != NULL;
576 	     node = next) {
577 		attr = rb_entry(node, struct mrp_attr, node);
578 		mrp_attr_event(app, attr, event);
579 	}
580 }
581 
582 static void mrp_join_timer_arm(struct mrp_applicant *app)
583 {
584 	unsigned long delay;
585 
586 	delay = (u64)msecs_to_jiffies(mrp_join_time) * net_random() >> 32;
587 	mod_timer(&app->join_timer, jiffies + delay);
588 }
589 
590 static void mrp_join_timer(unsigned long data)
591 {
592 	struct mrp_applicant *app = (struct mrp_applicant *)data;
593 
594 	spin_lock(&app->lock);
595 	mrp_mad_event(app, MRP_EVENT_TX);
596 	mrp_pdu_queue(app);
597 	spin_unlock(&app->lock);
598 
599 	mrp_queue_xmit(app);
600 	mrp_join_timer_arm(app);
601 }
602 
603 static void mrp_periodic_timer_arm(struct mrp_applicant *app)
604 {
605 	mod_timer(&app->periodic_timer,
606 		  jiffies + msecs_to_jiffies(mrp_periodic_time));
607 }
608 
609 static void mrp_periodic_timer(unsigned long data)
610 {
611 	struct mrp_applicant *app = (struct mrp_applicant *)data;
612 
613 	spin_lock(&app->lock);
614 	mrp_mad_event(app, MRP_EVENT_PERIODIC);
615 	mrp_pdu_queue(app);
616 	spin_unlock(&app->lock);
617 
618 	mrp_periodic_timer_arm(app);
619 }
620 
621 static int mrp_pdu_parse_end_mark(struct sk_buff *skb, int *offset)
622 {
623 	__be16 endmark;
624 
625 	if (skb_copy_bits(skb, *offset, &endmark, sizeof(endmark)) < 0)
626 		return -1;
627 	if (endmark == MRP_END_MARK) {
628 		*offset += sizeof(endmark);
629 		return -1;
630 	}
631 	return 0;
632 }
633 
634 static void mrp_pdu_parse_vecattr_event(struct mrp_applicant *app,
635 					struct sk_buff *skb,
636 					enum mrp_vecattr_event vaevent)
637 {
638 	struct mrp_attr *attr;
639 	enum mrp_event event;
640 
641 	attr = mrp_attr_lookup(app, mrp_cb(skb)->attrvalue,
642 			       mrp_cb(skb)->mh->attrlen,
643 			       mrp_cb(skb)->mh->attrtype);
644 	if (attr == NULL)
645 		return;
646 
647 	switch (vaevent) {
648 	case MRP_VECATTR_EVENT_NEW:
649 		event = MRP_EVENT_R_NEW;
650 		break;
651 	case MRP_VECATTR_EVENT_JOIN_IN:
652 		event = MRP_EVENT_R_JOIN_IN;
653 		break;
654 	case MRP_VECATTR_EVENT_IN:
655 		event = MRP_EVENT_R_IN;
656 		break;
657 	case MRP_VECATTR_EVENT_JOIN_MT:
658 		event = MRP_EVENT_R_JOIN_MT;
659 		break;
660 	case MRP_VECATTR_EVENT_MT:
661 		event = MRP_EVENT_R_MT;
662 		break;
663 	case MRP_VECATTR_EVENT_LV:
664 		event = MRP_EVENT_R_LV;
665 		break;
666 	default:
667 		return;
668 	}
669 
670 	mrp_attr_event(app, attr, event);
671 }
672 
673 static int mrp_pdu_parse_vecattr(struct mrp_applicant *app,
674 				 struct sk_buff *skb, int *offset)
675 {
676 	struct mrp_vecattr_hdr _vah;
677 	u16 valen;
678 	u8 vaevents, vaevent;
679 
680 	mrp_cb(skb)->vah = skb_header_pointer(skb, *offset, sizeof(_vah),
681 					      &_vah);
682 	if (!mrp_cb(skb)->vah)
683 		return -1;
684 	*offset += sizeof(_vah);
685 
686 	if (get_unaligned(&mrp_cb(skb)->vah->lenflags) &
687 	    MRP_VECATTR_HDR_FLAG_LA)
688 		mrp_mad_event(app, MRP_EVENT_R_LA);
689 	valen = be16_to_cpu(get_unaligned(&mrp_cb(skb)->vah->lenflags) &
690 			    MRP_VECATTR_HDR_LEN_MASK);
691 
692 	/* The VectorAttribute structure in a PDU carries event information
693 	 * about one or more attributes having consecutive values. Only the
694 	 * value for the first attribute is contained in the structure. So
695 	 * we make a copy of that value, and then increment it each time we
696 	 * advance to the next event in its Vector.
697 	 */
698 	if (sizeof(struct mrp_skb_cb) + mrp_cb(skb)->mh->attrlen >
699 	    FIELD_SIZEOF(struct sk_buff, cb))
700 		return -1;
701 	if (skb_copy_bits(skb, *offset, mrp_cb(skb)->attrvalue,
702 			  mrp_cb(skb)->mh->attrlen) < 0)
703 		return -1;
704 	*offset += mrp_cb(skb)->mh->attrlen;
705 
706 	/* In a VectorAttribute, the Vector contains events which are packed
707 	 * three to a byte. We process one byte of the Vector at a time.
708 	 */
709 	while (valen > 0) {
710 		if (skb_copy_bits(skb, *offset, &vaevents,
711 				  sizeof(vaevents)) < 0)
712 			return -1;
713 		*offset += sizeof(vaevents);
714 
715 		/* Extract and process the first event. */
716 		vaevent = vaevents / (__MRP_VECATTR_EVENT_MAX *
717 				      __MRP_VECATTR_EVENT_MAX);
718 		if (vaevent >= __MRP_VECATTR_EVENT_MAX) {
719 			/* The byte is malformed; stop processing. */
720 			return -1;
721 		}
722 		mrp_pdu_parse_vecattr_event(app, skb, vaevent);
723 
724 		/* If present, extract and process the second event. */
725 		if (!--valen)
726 			break;
727 		mrp_attrvalue_inc(mrp_cb(skb)->attrvalue,
728 				  mrp_cb(skb)->mh->attrlen);
729 		vaevents %= (__MRP_VECATTR_EVENT_MAX *
730 			     __MRP_VECATTR_EVENT_MAX);
731 		vaevent = vaevents / __MRP_VECATTR_EVENT_MAX;
732 		mrp_pdu_parse_vecattr_event(app, skb, vaevent);
733 
734 		/* If present, extract and process the third event. */
735 		if (!--valen)
736 			break;
737 		mrp_attrvalue_inc(mrp_cb(skb)->attrvalue,
738 				  mrp_cb(skb)->mh->attrlen);
739 		vaevents %= __MRP_VECATTR_EVENT_MAX;
740 		vaevent = vaevents;
741 		mrp_pdu_parse_vecattr_event(app, skb, vaevent);
742 	}
743 	return 0;
744 }
745 
746 static int mrp_pdu_parse_msg(struct mrp_applicant *app, struct sk_buff *skb,
747 			     int *offset)
748 {
749 	struct mrp_msg_hdr _mh;
750 
751 	mrp_cb(skb)->mh = skb_header_pointer(skb, *offset, sizeof(_mh), &_mh);
752 	if (!mrp_cb(skb)->mh)
753 		return -1;
754 	*offset += sizeof(_mh);
755 
756 	if (mrp_cb(skb)->mh->attrtype == 0 ||
757 	    mrp_cb(skb)->mh->attrtype > app->app->maxattr ||
758 	    mrp_cb(skb)->mh->attrlen == 0)
759 		return -1;
760 
761 	while (skb->len > *offset) {
762 		if (mrp_pdu_parse_end_mark(skb, offset) < 0)
763 			break;
764 		if (mrp_pdu_parse_vecattr(app, skb, offset) < 0)
765 			return -1;
766 	}
767 	return 0;
768 }
769 
770 static int mrp_rcv(struct sk_buff *skb, struct net_device *dev,
771 		   struct packet_type *pt, struct net_device *orig_dev)
772 {
773 	struct mrp_application *appl = container_of(pt, struct mrp_application,
774 						    pkttype);
775 	struct mrp_port *port;
776 	struct mrp_applicant *app;
777 	struct mrp_pdu_hdr _ph;
778 	const struct mrp_pdu_hdr *ph;
779 	int offset = skb_network_offset(skb);
780 
781 	/* If the interface is in promiscuous mode, drop the packet if
782 	 * it was unicast to another host.
783 	 */
784 	if (unlikely(skb->pkt_type == PACKET_OTHERHOST))
785 		goto out;
786 	skb = skb_share_check(skb, GFP_ATOMIC);
787 	if (unlikely(!skb))
788 		goto out;
789 	port = rcu_dereference(dev->mrp_port);
790 	if (unlikely(!port))
791 		goto out;
792 	app = rcu_dereference(port->applicants[appl->type]);
793 	if (unlikely(!app))
794 		goto out;
795 
796 	ph = skb_header_pointer(skb, offset, sizeof(_ph), &_ph);
797 	if (!ph)
798 		goto out;
799 	offset += sizeof(_ph);
800 
801 	if (ph->version != app->app->version)
802 		goto out;
803 
804 	spin_lock(&app->lock);
805 	while (skb->len > offset) {
806 		if (mrp_pdu_parse_end_mark(skb, &offset) < 0)
807 			break;
808 		if (mrp_pdu_parse_msg(app, skb, &offset) < 0)
809 			break;
810 	}
811 	spin_unlock(&app->lock);
812 out:
813 	kfree_skb(skb);
814 	return 0;
815 }
816 
817 static int mrp_init_port(struct net_device *dev)
818 {
819 	struct mrp_port *port;
820 
821 	port = kzalloc(sizeof(*port), GFP_KERNEL);
822 	if (!port)
823 		return -ENOMEM;
824 	rcu_assign_pointer(dev->mrp_port, port);
825 	return 0;
826 }
827 
828 static void mrp_release_port(struct net_device *dev)
829 {
830 	struct mrp_port *port = rtnl_dereference(dev->mrp_port);
831 	unsigned int i;
832 
833 	for (i = 0; i <= MRP_APPLICATION_MAX; i++) {
834 		if (rtnl_dereference(port->applicants[i]))
835 			return;
836 	}
837 	RCU_INIT_POINTER(dev->mrp_port, NULL);
838 	kfree_rcu(port, rcu);
839 }
840 
841 int mrp_init_applicant(struct net_device *dev, struct mrp_application *appl)
842 {
843 	struct mrp_applicant *app;
844 	int err;
845 
846 	ASSERT_RTNL();
847 
848 	if (!rtnl_dereference(dev->mrp_port)) {
849 		err = mrp_init_port(dev);
850 		if (err < 0)
851 			goto err1;
852 	}
853 
854 	err = -ENOMEM;
855 	app = kzalloc(sizeof(*app), GFP_KERNEL);
856 	if (!app)
857 		goto err2;
858 
859 	err = dev_mc_add(dev, appl->group_address);
860 	if (err < 0)
861 		goto err3;
862 
863 	app->dev = dev;
864 	app->app = appl;
865 	app->mad = RB_ROOT;
866 	spin_lock_init(&app->lock);
867 	skb_queue_head_init(&app->queue);
868 	rcu_assign_pointer(dev->mrp_port->applicants[appl->type], app);
869 	setup_timer(&app->join_timer, mrp_join_timer, (unsigned long)app);
870 	mrp_join_timer_arm(app);
871 	setup_timer(&app->periodic_timer, mrp_periodic_timer,
872 		    (unsigned long)app);
873 	mrp_periodic_timer_arm(app);
874 	return 0;
875 
876 err3:
877 	kfree(app);
878 err2:
879 	mrp_release_port(dev);
880 err1:
881 	return err;
882 }
883 EXPORT_SYMBOL_GPL(mrp_init_applicant);
884 
885 void mrp_uninit_applicant(struct net_device *dev, struct mrp_application *appl)
886 {
887 	struct mrp_port *port = rtnl_dereference(dev->mrp_port);
888 	struct mrp_applicant *app = rtnl_dereference(
889 		port->applicants[appl->type]);
890 
891 	ASSERT_RTNL();
892 
893 	RCU_INIT_POINTER(port->applicants[appl->type], NULL);
894 
895 	/* Delete timer and generate a final TX event to flush out
896 	 * all pending messages before the applicant is gone.
897 	 */
898 	del_timer_sync(&app->join_timer);
899 	del_timer_sync(&app->periodic_timer);
900 
901 	spin_lock_bh(&app->lock);
902 	mrp_mad_event(app, MRP_EVENT_TX);
903 	mrp_pdu_queue(app);
904 	spin_unlock_bh(&app->lock);
905 
906 	mrp_queue_xmit(app);
907 
908 	dev_mc_del(dev, appl->group_address);
909 	kfree_rcu(app, rcu);
910 	mrp_release_port(dev);
911 }
912 EXPORT_SYMBOL_GPL(mrp_uninit_applicant);
913 
914 int mrp_register_application(struct mrp_application *appl)
915 {
916 	appl->pkttype.func = mrp_rcv;
917 	dev_add_pack(&appl->pkttype);
918 	return 0;
919 }
920 EXPORT_SYMBOL_GPL(mrp_register_application);
921 
922 void mrp_unregister_application(struct mrp_application *appl)
923 {
924 	dev_remove_pack(&appl->pkttype);
925 }
926 EXPORT_SYMBOL_GPL(mrp_unregister_application);
927