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  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
 21static unsigned int mrp_join_time __read_mostly = 200;
 22module_param(mrp_join_time, uint, 0644);
 23MODULE_PARM_DESC(mrp_join_time, "Join time in ms (default 200ms)");
 24
 25static unsigned int mrp_periodic_time __read_mostly = 1000;
 26module_param(mrp_periodic_time, uint, 0644);
 27MODULE_PARM_DESC(mrp_periodic_time, "Periodic time in ms (default 1s)");
 28
 29MODULE_LICENSE("GPL");
 30
 31static const u8
 32mrp_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
200static const u8
201mrp_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
215static 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
226static 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
236static 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
256static 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
289static 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
295static void mrp_attr_destroy_all(struct mrp_applicant *app)
296{
297	struct rb_node *node, *next;
298	struct mrp_attr *attr;
299
300	for (node = rb_first(&app->mad);
301	     next = node ? rb_next(node) : NULL, node != NULL;
302	     node = next) {
303		attr = rb_entry(node, struct mrp_attr, node);
304		mrp_attr_destroy(app, attr);
305	}
306}
307
308static int mrp_pdu_init(struct mrp_applicant *app)
309{
310	struct sk_buff *skb;
311	struct mrp_pdu_hdr *ph;
312
313	skb = alloc_skb(app->dev->mtu + LL_RESERVED_SPACE(app->dev),
314			GFP_ATOMIC);
315	if (!skb)
316		return -ENOMEM;
317
318	skb->dev = app->dev;
319	skb->protocol = app->app->pkttype.type;
320	skb_reserve(skb, LL_RESERVED_SPACE(app->dev));
321	skb_reset_network_header(skb);
322	skb_reset_transport_header(skb);
323
324	ph = __skb_put(skb, sizeof(*ph));
325	ph->version = app->app->version;
326
327	app->pdu = skb;
328	return 0;
329}
330
331static int mrp_pdu_append_end_mark(struct mrp_applicant *app)
332{
333	__be16 *endmark;
334
335	if (skb_tailroom(app->pdu) < sizeof(*endmark))
336		return -1;
337	endmark = __skb_put(app->pdu, sizeof(*endmark));
338	put_unaligned(MRP_END_MARK, endmark);
339	return 0;
340}
341
342static void mrp_pdu_queue(struct mrp_applicant *app)
343{
344	if (!app->pdu)
345		return;
346
347	if (mrp_cb(app->pdu)->mh)
348		mrp_pdu_append_end_mark(app);
349	mrp_pdu_append_end_mark(app);
350
351	dev_hard_header(app->pdu, app->dev, ntohs(app->app->pkttype.type),
352			app->app->group_address, app->dev->dev_addr,
353			app->pdu->len);
354
355	skb_queue_tail(&app->queue, app->pdu);
356	app->pdu = NULL;
357}
358
359static void mrp_queue_xmit(struct mrp_applicant *app)
360{
361	struct sk_buff *skb;
362
363	while ((skb = skb_dequeue(&app->queue)))
364		dev_queue_xmit(skb);
365}
366
367static int mrp_pdu_append_msg_hdr(struct mrp_applicant *app,
368				  u8 attrtype, u8 attrlen)
369{
370	struct mrp_msg_hdr *mh;
371
372	if (mrp_cb(app->pdu)->mh) {
373		if (mrp_pdu_append_end_mark(app) < 0)
374			return -1;
375		mrp_cb(app->pdu)->mh = NULL;
376		mrp_cb(app->pdu)->vah = NULL;
377	}
378
379	if (skb_tailroom(app->pdu) < sizeof(*mh))
380		return -1;
381	mh = __skb_put(app->pdu, sizeof(*mh));
382	mh->attrtype = attrtype;
383	mh->attrlen = attrlen;
384	mrp_cb(app->pdu)->mh = mh;
385	return 0;
386}
387
388static int mrp_pdu_append_vecattr_hdr(struct mrp_applicant *app,
389				      const void *firstattrvalue, u8 attrlen)
390{
391	struct mrp_vecattr_hdr *vah;
392
393	if (skb_tailroom(app->pdu) < sizeof(*vah) + attrlen)
394		return -1;
395	vah = __skb_put(app->pdu, sizeof(*vah) + attrlen);
396	put_unaligned(0, &vah->lenflags);
397	memcpy(vah->firstattrvalue, firstattrvalue, attrlen);
398	mrp_cb(app->pdu)->vah = vah;
399	memcpy(mrp_cb(app->pdu)->attrvalue, firstattrvalue, attrlen);
400	return 0;
401}
402
403static int mrp_pdu_append_vecattr_event(struct mrp_applicant *app,
404					const struct mrp_attr *attr,
405					enum mrp_vecattr_event vaevent)
406{
407	u16 len, pos;
408	u8 *vaevents;
409	int err;
410again:
411	if (!app->pdu) {
412		err = mrp_pdu_init(app);
413		if (err < 0)
414			return err;
415	}
416
417	/* If there is no Message header in the PDU, or the Message header is
418	 * for a different attribute type, add an EndMark (if necessary) and a
419	 * new Message header to the PDU.
420	 */
421	if (!mrp_cb(app->pdu)->mh ||
422	    mrp_cb(app->pdu)->mh->attrtype != attr->type ||
423	    mrp_cb(app->pdu)->mh->attrlen != attr->len) {
424		if (mrp_pdu_append_msg_hdr(app, attr->type, attr->len) < 0)
425			goto queue;
426	}
427
428	/* If there is no VectorAttribute header for this Message in the PDU,
429	 * or this attribute's value does not sequentially follow the previous
430	 * attribute's value, add a new VectorAttribute header to the PDU.
431	 */
432	if (!mrp_cb(app->pdu)->vah ||
433	    memcmp(mrp_cb(app->pdu)->attrvalue, attr->value, attr->len)) {
434		if (mrp_pdu_append_vecattr_hdr(app, attr->value, attr->len) < 0)
435			goto queue;
436	}
437
438	len = be16_to_cpu(get_unaligned(&mrp_cb(app->pdu)->vah->lenflags));
439	pos = len % 3;
440
441	/* Events are packed into Vectors in the PDU, three to a byte. Add a
442	 * byte to the end of the Vector if necessary.
443	 */
444	if (!pos) {
445		if (skb_tailroom(app->pdu) < sizeof(u8))
446			goto queue;
447		vaevents = __skb_put(app->pdu, sizeof(u8));
448	} else {
449		vaevents = (u8 *)(skb_tail_pointer(app->pdu) - sizeof(u8));
450	}
451
452	switch (pos) {
453	case 0:
454		*vaevents = vaevent * (__MRP_VECATTR_EVENT_MAX *
455				       __MRP_VECATTR_EVENT_MAX);
456		break;
457	case 1:
458		*vaevents += vaevent * __MRP_VECATTR_EVENT_MAX;
459		break;
460	case 2:
461		*vaevents += vaevent;
462		break;
463	default:
464		WARN_ON(1);
465	}
466
467	/* Increment the length of the VectorAttribute in the PDU, as well as
468	 * the value of the next attribute that would continue its Vector.
469	 */
470	put_unaligned(cpu_to_be16(++len), &mrp_cb(app->pdu)->vah->lenflags);
471	mrp_attrvalue_inc(mrp_cb(app->pdu)->attrvalue, attr->len);
472
473	return 0;
474
475queue:
476	mrp_pdu_queue(app);
477	goto again;
478}
479
480static void mrp_attr_event(struct mrp_applicant *app,
481			   struct mrp_attr *attr, enum mrp_event event)
482{
483	enum mrp_applicant_state state;
484
485	state = mrp_applicant_state_table[attr->state][event];
486	if (state == MRP_APPLICANT_INVALID) {
487		WARN_ON(1);
488		return;
489	}
490
491	if (event == MRP_EVENT_TX) {
492		/* When appending the attribute fails, don't update its state
493		 * in order to retry at the next TX event.
494		 */
495
496		switch (mrp_tx_action_table[attr->state]) {
497		case MRP_TX_ACTION_NONE:
498		case MRP_TX_ACTION_S_JOIN_IN_OPTIONAL:
499		case MRP_TX_ACTION_S_IN_OPTIONAL:
500			break;
501		case MRP_TX_ACTION_S_NEW:
502			if (mrp_pdu_append_vecattr_event(
503				    app, attr, MRP_VECATTR_EVENT_NEW) < 0)
504				return;
505			break;
506		case MRP_TX_ACTION_S_JOIN_IN:
507			if (mrp_pdu_append_vecattr_event(
508				    app, attr, MRP_VECATTR_EVENT_JOIN_IN) < 0)
509				return;
510			break;
511		case MRP_TX_ACTION_S_LV:
512			if (mrp_pdu_append_vecattr_event(
513				    app, attr, MRP_VECATTR_EVENT_LV) < 0)
514				return;
515			/* As a pure applicant, sending a leave message
516			 * implies that the attribute was unregistered and
517			 * can be destroyed.
518			 */
519			mrp_attr_destroy(app, attr);
520			return;
521		default:
522			WARN_ON(1);
523		}
524	}
525
526	attr->state = state;
527}
528
529int mrp_request_join(const struct net_device *dev,
530		     const struct mrp_application *appl,
531		     const void *value, u8 len, u8 type)
532{
533	struct mrp_port *port = rtnl_dereference(dev->mrp_port);
534	struct mrp_applicant *app = rtnl_dereference(
535		port->applicants[appl->type]);
536	struct mrp_attr *attr;
537
538	if (sizeof(struct mrp_skb_cb) + len >
539	    sizeof_field(struct sk_buff, cb))
540		return -ENOMEM;
541
542	spin_lock_bh(&app->lock);
543	attr = mrp_attr_create(app, value, len, type);
544	if (!attr) {
545		spin_unlock_bh(&app->lock);
546		return -ENOMEM;
547	}
548	mrp_attr_event(app, attr, MRP_EVENT_JOIN);
549	spin_unlock_bh(&app->lock);
550	return 0;
551}
552EXPORT_SYMBOL_GPL(mrp_request_join);
553
554void mrp_request_leave(const struct net_device *dev,
555		       const struct mrp_application *appl,
556		       const void *value, u8 len, u8 type)
557{
558	struct mrp_port *port = rtnl_dereference(dev->mrp_port);
559	struct mrp_applicant *app = rtnl_dereference(
560		port->applicants[appl->type]);
561	struct mrp_attr *attr;
562
563	if (sizeof(struct mrp_skb_cb) + len >
564	    sizeof_field(struct sk_buff, cb))
565		return;
566
567	spin_lock_bh(&app->lock);
568	attr = mrp_attr_lookup(app, value, len, type);
569	if (!attr) {
570		spin_unlock_bh(&app->lock);
571		return;
572	}
573	mrp_attr_event(app, attr, MRP_EVENT_LV);
574	spin_unlock_bh(&app->lock);
575}
576EXPORT_SYMBOL_GPL(mrp_request_leave);
577
578static void mrp_mad_event(struct mrp_applicant *app, enum mrp_event event)
579{
580	struct rb_node *node, *next;
581	struct mrp_attr *attr;
582
583	for (node = rb_first(&app->mad);
584	     next = node ? rb_next(node) : NULL, node != NULL;
585	     node = next) {
586		attr = rb_entry(node, struct mrp_attr, node);
587		mrp_attr_event(app, attr, event);
588	}
589}
590
591static void mrp_join_timer_arm(struct mrp_applicant *app)
592{
593	unsigned long delay;
594
595	delay = (u64)msecs_to_jiffies(mrp_join_time) * prandom_u32() >> 32;
596	mod_timer(&app->join_timer, jiffies + delay);
597}
598
599static void mrp_join_timer(struct timer_list *t)
600{
601	struct mrp_applicant *app = from_timer(app, t, join_timer);
602
603	spin_lock(&app->lock);
604	mrp_mad_event(app, MRP_EVENT_TX);
605	mrp_pdu_queue(app);
606	spin_unlock(&app->lock);
607
608	mrp_queue_xmit(app);
609	mrp_join_timer_arm(app);
610}
611
612static void mrp_periodic_timer_arm(struct mrp_applicant *app)
613{
614	mod_timer(&app->periodic_timer,
615		  jiffies + msecs_to_jiffies(mrp_periodic_time));
616}
617
618static void mrp_periodic_timer(struct timer_list *t)
619{
620	struct mrp_applicant *app = from_timer(app, t, periodic_timer);
621
622	spin_lock(&app->lock);
623	mrp_mad_event(app, MRP_EVENT_PERIODIC);
624	mrp_pdu_queue(app);
625	spin_unlock(&app->lock);
626
627	mrp_periodic_timer_arm(app);
628}
629
630static int mrp_pdu_parse_end_mark(struct sk_buff *skb, int *offset)
631{
632	__be16 endmark;
633
634	if (skb_copy_bits(skb, *offset, &endmark, sizeof(endmark)) < 0)
635		return -1;
636	if (endmark == MRP_END_MARK) {
637		*offset += sizeof(endmark);
638		return -1;
639	}
640	return 0;
641}
642
643static void mrp_pdu_parse_vecattr_event(struct mrp_applicant *app,
644					struct sk_buff *skb,
645					enum mrp_vecattr_event vaevent)
646{
647	struct mrp_attr *attr;
648	enum mrp_event event;
649
650	attr = mrp_attr_lookup(app, mrp_cb(skb)->attrvalue,
651			       mrp_cb(skb)->mh->attrlen,
652			       mrp_cb(skb)->mh->attrtype);
653	if (attr == NULL)
654		return;
655
656	switch (vaevent) {
657	case MRP_VECATTR_EVENT_NEW:
658		event = MRP_EVENT_R_NEW;
659		break;
660	case MRP_VECATTR_EVENT_JOIN_IN:
661		event = MRP_EVENT_R_JOIN_IN;
662		break;
663	case MRP_VECATTR_EVENT_IN:
664		event = MRP_EVENT_R_IN;
665		break;
666	case MRP_VECATTR_EVENT_JOIN_MT:
667		event = MRP_EVENT_R_JOIN_MT;
668		break;
669	case MRP_VECATTR_EVENT_MT:
670		event = MRP_EVENT_R_MT;
671		break;
672	case MRP_VECATTR_EVENT_LV:
673		event = MRP_EVENT_R_LV;
674		break;
675	default:
676		return;
677	}
678
679	mrp_attr_event(app, attr, event);
680}
681
682static int mrp_pdu_parse_vecattr(struct mrp_applicant *app,
683				 struct sk_buff *skb, int *offset)
684{
685	struct mrp_vecattr_hdr _vah;
686	u16 valen;
687	u8 vaevents, vaevent;
688
689	mrp_cb(skb)->vah = skb_header_pointer(skb, *offset, sizeof(_vah),
690					      &_vah);
691	if (!mrp_cb(skb)->vah)
692		return -1;
693	*offset += sizeof(_vah);
694
695	if (get_unaligned(&mrp_cb(skb)->vah->lenflags) &
696	    MRP_VECATTR_HDR_FLAG_LA)
697		mrp_mad_event(app, MRP_EVENT_R_LA);
698	valen = be16_to_cpu(get_unaligned(&mrp_cb(skb)->vah->lenflags) &
699			    MRP_VECATTR_HDR_LEN_MASK);
700
701	/* The VectorAttribute structure in a PDU carries event information
702	 * about one or more attributes having consecutive values. Only the
703	 * value for the first attribute is contained in the structure. So
704	 * we make a copy of that value, and then increment it each time we
705	 * advance to the next event in its Vector.
706	 */
707	if (sizeof(struct mrp_skb_cb) + mrp_cb(skb)->mh->attrlen >
708	    sizeof_field(struct sk_buff, cb))
709		return -1;
710	if (skb_copy_bits(skb, *offset, mrp_cb(skb)->attrvalue,
711			  mrp_cb(skb)->mh->attrlen) < 0)
712		return -1;
713	*offset += mrp_cb(skb)->mh->attrlen;
714
715	/* In a VectorAttribute, the Vector contains events which are packed
716	 * three to a byte. We process one byte of the Vector at a time.
717	 */
718	while (valen > 0) {
719		if (skb_copy_bits(skb, *offset, &vaevents,
720				  sizeof(vaevents)) < 0)
721			return -1;
722		*offset += sizeof(vaevents);
723
724		/* Extract and process the first event. */
725		vaevent = vaevents / (__MRP_VECATTR_EVENT_MAX *
726				      __MRP_VECATTR_EVENT_MAX);
727		if (vaevent >= __MRP_VECATTR_EVENT_MAX) {
728			/* The byte is malformed; stop processing. */
729			return -1;
730		}
731		mrp_pdu_parse_vecattr_event(app, skb, vaevent);
732
733		/* If present, extract and process the second event. */
734		if (!--valen)
735			break;
736		mrp_attrvalue_inc(mrp_cb(skb)->attrvalue,
737				  mrp_cb(skb)->mh->attrlen);
738		vaevents %= (__MRP_VECATTR_EVENT_MAX *
739			     __MRP_VECATTR_EVENT_MAX);
740		vaevent = vaevents / __MRP_VECATTR_EVENT_MAX;
741		mrp_pdu_parse_vecattr_event(app, skb, vaevent);
742
743		/* If present, extract and process the third event. */
744		if (!--valen)
745			break;
746		mrp_attrvalue_inc(mrp_cb(skb)->attrvalue,
747				  mrp_cb(skb)->mh->attrlen);
748		vaevents %= __MRP_VECATTR_EVENT_MAX;
749		vaevent = vaevents;
750		mrp_pdu_parse_vecattr_event(app, skb, vaevent);
751	}
752	return 0;
753}
754
755static int mrp_pdu_parse_msg(struct mrp_applicant *app, struct sk_buff *skb,
756			     int *offset)
757{
758	struct mrp_msg_hdr _mh;
759
760	mrp_cb(skb)->mh = skb_header_pointer(skb, *offset, sizeof(_mh), &_mh);
761	if (!mrp_cb(skb)->mh)
762		return -1;
763	*offset += sizeof(_mh);
764
765	if (mrp_cb(skb)->mh->attrtype == 0 ||
766	    mrp_cb(skb)->mh->attrtype > app->app->maxattr ||
767	    mrp_cb(skb)->mh->attrlen == 0)
768		return -1;
769
770	while (skb->len > *offset) {
771		if (mrp_pdu_parse_end_mark(skb, offset) < 0)
772			break;
773		if (mrp_pdu_parse_vecattr(app, skb, offset) < 0)
774			return -1;
775	}
776	return 0;
777}
778
779static int mrp_rcv(struct sk_buff *skb, struct net_device *dev,
780		   struct packet_type *pt, struct net_device *orig_dev)
781{
782	struct mrp_application *appl = container_of(pt, struct mrp_application,
783						    pkttype);
784	struct mrp_port *port;
785	struct mrp_applicant *app;
786	struct mrp_pdu_hdr _ph;
787	const struct mrp_pdu_hdr *ph;
788	int offset = skb_network_offset(skb);
789
790	/* If the interface is in promiscuous mode, drop the packet if
791	 * it was unicast to another host.
792	 */
793	if (unlikely(skb->pkt_type == PACKET_OTHERHOST))
794		goto out;
795	skb = skb_share_check(skb, GFP_ATOMIC);
796	if (unlikely(!skb))
797		goto out;
798	port = rcu_dereference(dev->mrp_port);
799	if (unlikely(!port))
800		goto out;
801	app = rcu_dereference(port->applicants[appl->type]);
802	if (unlikely(!app))
803		goto out;
804
805	ph = skb_header_pointer(skb, offset, sizeof(_ph), &_ph);
806	if (!ph)
807		goto out;
808	offset += sizeof(_ph);
809
810	if (ph->version != app->app->version)
811		goto out;
812
813	spin_lock(&app->lock);
814	while (skb->len > offset) {
815		if (mrp_pdu_parse_end_mark(skb, &offset) < 0)
816			break;
817		if (mrp_pdu_parse_msg(app, skb, &offset) < 0)
818			break;
819	}
820	spin_unlock(&app->lock);
821out:
822	kfree_skb(skb);
823	return 0;
824}
825
826static int mrp_init_port(struct net_device *dev)
827{
828	struct mrp_port *port;
829
830	port = kzalloc(sizeof(*port), GFP_KERNEL);
831	if (!port)
832		return -ENOMEM;
833	rcu_assign_pointer(dev->mrp_port, port);
834	return 0;
835}
836
837static void mrp_release_port(struct net_device *dev)
838{
839	struct mrp_port *port = rtnl_dereference(dev->mrp_port);
840	unsigned int i;
841
842	for (i = 0; i <= MRP_APPLICATION_MAX; i++) {
843		if (rtnl_dereference(port->applicants[i]))
844			return;
845	}
846	RCU_INIT_POINTER(dev->mrp_port, NULL);
847	kfree_rcu(port, rcu);
848}
849
850int mrp_init_applicant(struct net_device *dev, struct mrp_application *appl)
851{
852	struct mrp_applicant *app;
853	int err;
854
855	ASSERT_RTNL();
856
857	if (!rtnl_dereference(dev->mrp_port)) {
858		err = mrp_init_port(dev);
859		if (err < 0)
860			goto err1;
861	}
862
863	err = -ENOMEM;
864	app = kzalloc(sizeof(*app), GFP_KERNEL);
865	if (!app)
866		goto err2;
867
868	err = dev_mc_add(dev, appl->group_address);
869	if (err < 0)
870		goto err3;
871
872	app->dev = dev;
873	app->app = appl;
874	app->mad = RB_ROOT;
875	spin_lock_init(&app->lock);
876	skb_queue_head_init(&app->queue);
877	rcu_assign_pointer(dev->mrp_port->applicants[appl->type], app);
878	timer_setup(&app->join_timer, mrp_join_timer, 0);
879	mrp_join_timer_arm(app);
880	timer_setup(&app->periodic_timer, mrp_periodic_timer, 0);
881	mrp_periodic_timer_arm(app);
882	return 0;
883
884err3:
885	kfree(app);
886err2:
887	mrp_release_port(dev);
888err1:
889	return err;
890}
891EXPORT_SYMBOL_GPL(mrp_init_applicant);
892
893void mrp_uninit_applicant(struct net_device *dev, struct mrp_application *appl)
894{
895	struct mrp_port *port = rtnl_dereference(dev->mrp_port);
896	struct mrp_applicant *app = rtnl_dereference(
897		port->applicants[appl->type]);
898
899	ASSERT_RTNL();
900
901	RCU_INIT_POINTER(port->applicants[appl->type], NULL);
902
903	/* Delete timer and generate a final TX event to flush out
904	 * all pending messages before the applicant is gone.
905	 */
906	del_timer_sync(&app->join_timer);
907	del_timer_sync(&app->periodic_timer);
908
909	spin_lock_bh(&app->lock);
910	mrp_mad_event(app, MRP_EVENT_TX);
911	mrp_attr_destroy_all(app);
912	mrp_pdu_queue(app);
913	spin_unlock_bh(&app->lock);
914
915	mrp_queue_xmit(app);
916
917	dev_mc_del(dev, appl->group_address);
918	kfree_rcu(app, rcu);
919	mrp_release_port(dev);
920}
921EXPORT_SYMBOL_GPL(mrp_uninit_applicant);
922
923int mrp_register_application(struct mrp_application *appl)
924{
925	appl->pkttype.func = mrp_rcv;
926	dev_add_pack(&appl->pkttype);
927	return 0;
928}
929EXPORT_SYMBOL_GPL(mrp_register_application);
930
931void mrp_unregister_application(struct mrp_application *appl)
932{
933	dev_remove_pack(&appl->pkttype);
934}
935EXPORT_SYMBOL_GPL(mrp_unregister_application);