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  
mrp_attrvalue_inc(void * value,u8 len)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  
mrp_attr_cmp(const struct mrp_attr * attr,const void * value,u8 len,u8 type)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  
mrp_attr_lookup(const struct mrp_applicant * app,const void * value,u8 len,u8 type)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  
mrp_attr_create(struct mrp_applicant * app,const void * value,u8 len,u8 type)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  
mrp_attr_destroy(struct mrp_applicant * app,struct mrp_attr * attr)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  
mrp_attr_destroy_all(struct mrp_applicant * app)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  
mrp_pdu_init(struct mrp_applicant * app)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  
mrp_pdu_append_end_mark(struct mrp_applicant * app)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  
mrp_pdu_queue(struct mrp_applicant * app)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  
mrp_queue_xmit(struct mrp_applicant * app)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  
mrp_pdu_append_msg_hdr(struct mrp_applicant * app,u8 attrtype,u8 attrlen)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  
mrp_pdu_append_vecattr_hdr(struct mrp_applicant * app,const void * firstattrvalue,u8 attrlen)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  
mrp_pdu_append_vecattr_event(struct mrp_applicant * app,const struct mrp_attr * attr,enum mrp_vecattr_event vaevent)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  
mrp_attr_event(struct mrp_applicant * app,struct mrp_attr * attr,enum mrp_event event)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  
mrp_request_join(const struct net_device * dev,const struct mrp_application * appl,const void * value,u8 len,u8 type)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  
mrp_request_leave(const struct net_device * dev,const struct mrp_application * appl,const void * value,u8 len,u8 type)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  
mrp_mad_event(struct mrp_applicant * app,enum mrp_event event)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  
mrp_join_timer_arm(struct mrp_applicant * app)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  
mrp_join_timer(struct timer_list * t)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  
mrp_periodic_timer_arm(struct mrp_applicant * app)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  
mrp_periodic_timer(struct timer_list * t)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  
mrp_pdu_parse_end_mark(struct sk_buff * skb,int * offset)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  
mrp_pdu_parse_vecattr_event(struct mrp_applicant * app,struct sk_buff * skb,enum mrp_vecattr_event vaevent)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  
mrp_pdu_parse_vecattr(struct mrp_applicant * app,struct sk_buff * skb,int * offset)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  
mrp_pdu_parse_msg(struct mrp_applicant * app,struct sk_buff * skb,int * offset)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  
mrp_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)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  
mrp_init_port(struct net_device * dev)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  
mrp_release_port(struct net_device * dev)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  
mrp_init_applicant(struct net_device * dev,struct mrp_application * appl)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  
mrp_uninit_applicant(struct net_device * dev,struct mrp_application * appl)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  
mrp_register_application(struct mrp_application * appl)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  
mrp_unregister_application(struct mrp_application * appl)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