xref: /linux/drivers/net/amt.c (revision 8e07e0e3964ca4e23ce7b68e2096fe660a888942)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Copyright (c) 2021 Taehee Yoo <ap420073@gmail.com> */
3 
4 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
5 
6 #include <linux/module.h>
7 #include <linux/skbuff.h>
8 #include <linux/udp.h>
9 #include <linux/jhash.h>
10 #include <linux/if_tunnel.h>
11 #include <linux/net.h>
12 #include <linux/igmp.h>
13 #include <linux/workqueue.h>
14 #include <net/sch_generic.h>
15 #include <net/net_namespace.h>
16 #include <net/ip.h>
17 #include <net/udp.h>
18 #include <net/udp_tunnel.h>
19 #include <net/icmp.h>
20 #include <net/mld.h>
21 #include <net/amt.h>
22 #include <uapi/linux/amt.h>
23 #include <linux/security.h>
24 #include <net/gro_cells.h>
25 #include <net/ipv6.h>
26 #include <net/if_inet6.h>
27 #include <net/ndisc.h>
28 #include <net/addrconf.h>
29 #include <net/ip6_route.h>
30 #include <net/inet_common.h>
31 #include <net/ip6_checksum.h>
32 
33 static struct workqueue_struct *amt_wq;
34 
35 static HLIST_HEAD(source_gc_list);
36 /* Lock for source_gc_list */
37 static spinlock_t source_gc_lock;
38 static struct delayed_work source_gc_wq;
39 static char *status_str[] = {
40 	"AMT_STATUS_INIT",
41 	"AMT_STATUS_SENT_DISCOVERY",
42 	"AMT_STATUS_RECEIVED_DISCOVERY",
43 	"AMT_STATUS_SENT_ADVERTISEMENT",
44 	"AMT_STATUS_RECEIVED_ADVERTISEMENT",
45 	"AMT_STATUS_SENT_REQUEST",
46 	"AMT_STATUS_RECEIVED_REQUEST",
47 	"AMT_STATUS_SENT_QUERY",
48 	"AMT_STATUS_RECEIVED_QUERY",
49 	"AMT_STATUS_SENT_UPDATE",
50 	"AMT_STATUS_RECEIVED_UPDATE",
51 };
52 
53 static char *type_str[] = {
54 	"", /* Type 0 is not defined */
55 	"AMT_MSG_DISCOVERY",
56 	"AMT_MSG_ADVERTISEMENT",
57 	"AMT_MSG_REQUEST",
58 	"AMT_MSG_MEMBERSHIP_QUERY",
59 	"AMT_MSG_MEMBERSHIP_UPDATE",
60 	"AMT_MSG_MULTICAST_DATA",
61 	"AMT_MSG_TEARDOWN",
62 };
63 
64 static char *action_str[] = {
65 	"AMT_ACT_GMI",
66 	"AMT_ACT_GMI_ZERO",
67 	"AMT_ACT_GT",
68 	"AMT_ACT_STATUS_FWD_NEW",
69 	"AMT_ACT_STATUS_D_FWD_NEW",
70 	"AMT_ACT_STATUS_NONE_NEW",
71 };
72 
73 static struct igmpv3_grec igmpv3_zero_grec;
74 
75 #if IS_ENABLED(CONFIG_IPV6)
76 #define MLD2_ALL_NODE_INIT { { { 0xff, 0x02, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x01 } } }
77 static struct in6_addr mld2_all_node = MLD2_ALL_NODE_INIT;
78 static struct mld2_grec mldv2_zero_grec;
79 #endif
80 
81 static struct amt_skb_cb *amt_skb_cb(struct sk_buff *skb)
82 {
83 	BUILD_BUG_ON(sizeof(struct amt_skb_cb) + sizeof(struct qdisc_skb_cb) >
84 		     sizeof_field(struct sk_buff, cb));
85 
86 	return (struct amt_skb_cb *)((void *)skb->cb +
87 		sizeof(struct qdisc_skb_cb));
88 }
89 
90 static void __amt_source_gc_work(void)
91 {
92 	struct amt_source_node *snode;
93 	struct hlist_head gc_list;
94 	struct hlist_node *t;
95 
96 	spin_lock_bh(&source_gc_lock);
97 	hlist_move_list(&source_gc_list, &gc_list);
98 	spin_unlock_bh(&source_gc_lock);
99 
100 	hlist_for_each_entry_safe(snode, t, &gc_list, node) {
101 		hlist_del_rcu(&snode->node);
102 		kfree_rcu(snode, rcu);
103 	}
104 }
105 
106 static void amt_source_gc_work(struct work_struct *work)
107 {
108 	__amt_source_gc_work();
109 
110 	spin_lock_bh(&source_gc_lock);
111 	mod_delayed_work(amt_wq, &source_gc_wq,
112 			 msecs_to_jiffies(AMT_GC_INTERVAL));
113 	spin_unlock_bh(&source_gc_lock);
114 }
115 
116 static bool amt_addr_equal(union amt_addr *a, union amt_addr *b)
117 {
118 	return !memcmp(a, b, sizeof(union amt_addr));
119 }
120 
121 static u32 amt_source_hash(struct amt_tunnel_list *tunnel, union amt_addr *src)
122 {
123 	u32 hash = jhash(src, sizeof(*src), tunnel->amt->hash_seed);
124 
125 	return reciprocal_scale(hash, tunnel->amt->hash_buckets);
126 }
127 
128 static bool amt_status_filter(struct amt_source_node *snode,
129 			      enum amt_filter filter)
130 {
131 	bool rc = false;
132 
133 	switch (filter) {
134 	case AMT_FILTER_FWD:
135 		if (snode->status == AMT_SOURCE_STATUS_FWD &&
136 		    snode->flags == AMT_SOURCE_OLD)
137 			rc = true;
138 		break;
139 	case AMT_FILTER_D_FWD:
140 		if (snode->status == AMT_SOURCE_STATUS_D_FWD &&
141 		    snode->flags == AMT_SOURCE_OLD)
142 			rc = true;
143 		break;
144 	case AMT_FILTER_FWD_NEW:
145 		if (snode->status == AMT_SOURCE_STATUS_FWD &&
146 		    snode->flags == AMT_SOURCE_NEW)
147 			rc = true;
148 		break;
149 	case AMT_FILTER_D_FWD_NEW:
150 		if (snode->status == AMT_SOURCE_STATUS_D_FWD &&
151 		    snode->flags == AMT_SOURCE_NEW)
152 			rc = true;
153 		break;
154 	case AMT_FILTER_ALL:
155 		rc = true;
156 		break;
157 	case AMT_FILTER_NONE_NEW:
158 		if (snode->status == AMT_SOURCE_STATUS_NONE &&
159 		    snode->flags == AMT_SOURCE_NEW)
160 			rc = true;
161 		break;
162 	case AMT_FILTER_BOTH:
163 		if ((snode->status == AMT_SOURCE_STATUS_D_FWD ||
164 		     snode->status == AMT_SOURCE_STATUS_FWD) &&
165 		    snode->flags == AMT_SOURCE_OLD)
166 			rc = true;
167 		break;
168 	case AMT_FILTER_BOTH_NEW:
169 		if ((snode->status == AMT_SOURCE_STATUS_D_FWD ||
170 		     snode->status == AMT_SOURCE_STATUS_FWD) &&
171 		    snode->flags == AMT_SOURCE_NEW)
172 			rc = true;
173 		break;
174 	default:
175 		WARN_ON_ONCE(1);
176 		break;
177 	}
178 
179 	return rc;
180 }
181 
182 static struct amt_source_node *amt_lookup_src(struct amt_tunnel_list *tunnel,
183 					      struct amt_group_node *gnode,
184 					      enum amt_filter filter,
185 					      union amt_addr *src)
186 {
187 	u32 hash = amt_source_hash(tunnel, src);
188 	struct amt_source_node *snode;
189 
190 	hlist_for_each_entry_rcu(snode, &gnode->sources[hash], node)
191 		if (amt_status_filter(snode, filter) &&
192 		    amt_addr_equal(&snode->source_addr, src))
193 			return snode;
194 
195 	return NULL;
196 }
197 
198 static u32 amt_group_hash(struct amt_tunnel_list *tunnel, union amt_addr *group)
199 {
200 	u32 hash = jhash(group, sizeof(*group), tunnel->amt->hash_seed);
201 
202 	return reciprocal_scale(hash, tunnel->amt->hash_buckets);
203 }
204 
205 static struct amt_group_node *amt_lookup_group(struct amt_tunnel_list *tunnel,
206 					       union amt_addr *group,
207 					       union amt_addr *host,
208 					       bool v6)
209 {
210 	u32 hash = amt_group_hash(tunnel, group);
211 	struct amt_group_node *gnode;
212 
213 	hlist_for_each_entry_rcu(gnode, &tunnel->groups[hash], node) {
214 		if (amt_addr_equal(&gnode->group_addr, group) &&
215 		    amt_addr_equal(&gnode->host_addr, host) &&
216 		    gnode->v6 == v6)
217 			return gnode;
218 	}
219 
220 	return NULL;
221 }
222 
223 static void amt_destroy_source(struct amt_source_node *snode)
224 {
225 	struct amt_group_node *gnode = snode->gnode;
226 	struct amt_tunnel_list *tunnel;
227 
228 	tunnel = gnode->tunnel_list;
229 
230 	if (!gnode->v6) {
231 		netdev_dbg(snode->gnode->amt->dev,
232 			   "Delete source %pI4 from %pI4\n",
233 			   &snode->source_addr.ip4,
234 			   &gnode->group_addr.ip4);
235 #if IS_ENABLED(CONFIG_IPV6)
236 	} else {
237 		netdev_dbg(snode->gnode->amt->dev,
238 			   "Delete source %pI6 from %pI6\n",
239 			   &snode->source_addr.ip6,
240 			   &gnode->group_addr.ip6);
241 #endif
242 	}
243 
244 	cancel_delayed_work(&snode->source_timer);
245 	hlist_del_init_rcu(&snode->node);
246 	tunnel->nr_sources--;
247 	gnode->nr_sources--;
248 	spin_lock_bh(&source_gc_lock);
249 	hlist_add_head_rcu(&snode->node, &source_gc_list);
250 	spin_unlock_bh(&source_gc_lock);
251 }
252 
253 static void amt_del_group(struct amt_dev *amt, struct amt_group_node *gnode)
254 {
255 	struct amt_source_node *snode;
256 	struct hlist_node *t;
257 	int i;
258 
259 	if (cancel_delayed_work(&gnode->group_timer))
260 		dev_put(amt->dev);
261 	hlist_del_rcu(&gnode->node);
262 	gnode->tunnel_list->nr_groups--;
263 
264 	if (!gnode->v6)
265 		netdev_dbg(amt->dev, "Leave group %pI4\n",
266 			   &gnode->group_addr.ip4);
267 #if IS_ENABLED(CONFIG_IPV6)
268 	else
269 		netdev_dbg(amt->dev, "Leave group %pI6\n",
270 			   &gnode->group_addr.ip6);
271 #endif
272 	for (i = 0; i < amt->hash_buckets; i++)
273 		hlist_for_each_entry_safe(snode, t, &gnode->sources[i], node)
274 			amt_destroy_source(snode);
275 
276 	/* tunnel->lock was acquired outside of amt_del_group()
277 	 * But rcu_read_lock() was acquired too so It's safe.
278 	 */
279 	kfree_rcu(gnode, rcu);
280 }
281 
282 /* If a source timer expires with a router filter-mode for the group of
283  * INCLUDE, the router concludes that traffic from this particular
284  * source is no longer desired on the attached network, and deletes the
285  * associated source record.
286  */
287 static void amt_source_work(struct work_struct *work)
288 {
289 	struct amt_source_node *snode = container_of(to_delayed_work(work),
290 						     struct amt_source_node,
291 						     source_timer);
292 	struct amt_group_node *gnode = snode->gnode;
293 	struct amt_dev *amt = gnode->amt;
294 	struct amt_tunnel_list *tunnel;
295 
296 	tunnel = gnode->tunnel_list;
297 	spin_lock_bh(&tunnel->lock);
298 	rcu_read_lock();
299 	if (gnode->filter_mode == MCAST_INCLUDE) {
300 		amt_destroy_source(snode);
301 		if (!gnode->nr_sources)
302 			amt_del_group(amt, gnode);
303 	} else {
304 		/* When a router filter-mode for a group is EXCLUDE,
305 		 * source records are only deleted when the group timer expires
306 		 */
307 		snode->status = AMT_SOURCE_STATUS_D_FWD;
308 	}
309 	rcu_read_unlock();
310 	spin_unlock_bh(&tunnel->lock);
311 }
312 
313 static void amt_act_src(struct amt_tunnel_list *tunnel,
314 			struct amt_group_node *gnode,
315 			struct amt_source_node *snode,
316 			enum amt_act act)
317 {
318 	struct amt_dev *amt = tunnel->amt;
319 
320 	switch (act) {
321 	case AMT_ACT_GMI:
322 		mod_delayed_work(amt_wq, &snode->source_timer,
323 				 msecs_to_jiffies(amt_gmi(amt)));
324 		break;
325 	case AMT_ACT_GMI_ZERO:
326 		cancel_delayed_work(&snode->source_timer);
327 		break;
328 	case AMT_ACT_GT:
329 		mod_delayed_work(amt_wq, &snode->source_timer,
330 				 gnode->group_timer.timer.expires);
331 		break;
332 	case AMT_ACT_STATUS_FWD_NEW:
333 		snode->status = AMT_SOURCE_STATUS_FWD;
334 		snode->flags = AMT_SOURCE_NEW;
335 		break;
336 	case AMT_ACT_STATUS_D_FWD_NEW:
337 		snode->status = AMT_SOURCE_STATUS_D_FWD;
338 		snode->flags = AMT_SOURCE_NEW;
339 		break;
340 	case AMT_ACT_STATUS_NONE_NEW:
341 		cancel_delayed_work(&snode->source_timer);
342 		snode->status = AMT_SOURCE_STATUS_NONE;
343 		snode->flags = AMT_SOURCE_NEW;
344 		break;
345 	default:
346 		WARN_ON_ONCE(1);
347 		return;
348 	}
349 
350 	if (!gnode->v6)
351 		netdev_dbg(amt->dev, "Source %pI4 from %pI4 Acted %s\n",
352 			   &snode->source_addr.ip4,
353 			   &gnode->group_addr.ip4,
354 			   action_str[act]);
355 #if IS_ENABLED(CONFIG_IPV6)
356 	else
357 		netdev_dbg(amt->dev, "Source %pI6 from %pI6 Acted %s\n",
358 			   &snode->source_addr.ip6,
359 			   &gnode->group_addr.ip6,
360 			   action_str[act]);
361 #endif
362 }
363 
364 static struct amt_source_node *amt_alloc_snode(struct amt_group_node *gnode,
365 					       union amt_addr *src)
366 {
367 	struct amt_source_node *snode;
368 
369 	snode = kzalloc(sizeof(*snode), GFP_ATOMIC);
370 	if (!snode)
371 		return NULL;
372 
373 	memcpy(&snode->source_addr, src, sizeof(union amt_addr));
374 	snode->gnode = gnode;
375 	snode->status = AMT_SOURCE_STATUS_NONE;
376 	snode->flags = AMT_SOURCE_NEW;
377 	INIT_HLIST_NODE(&snode->node);
378 	INIT_DELAYED_WORK(&snode->source_timer, amt_source_work);
379 
380 	return snode;
381 }
382 
383 /* RFC 3810 - 7.2.2.  Definition of Filter Timers
384  *
385  *  Router Mode          Filter Timer         Actions/Comments
386  *  -----------       -----------------       ----------------
387  *
388  *    INCLUDE             Not Used            All listeners in
389  *                                            INCLUDE mode.
390  *
391  *    EXCLUDE             Timer > 0           At least one listener
392  *                                            in EXCLUDE mode.
393  *
394  *    EXCLUDE             Timer == 0          No more listeners in
395  *                                            EXCLUDE mode for the
396  *                                            multicast address.
397  *                                            If the Requested List
398  *                                            is empty, delete
399  *                                            Multicast Address
400  *                                            Record.  If not, switch
401  *                                            to INCLUDE filter mode;
402  *                                            the sources in the
403  *                                            Requested List are
404  *                                            moved to the Include
405  *                                            List, and the Exclude
406  *                                            List is deleted.
407  */
408 static void amt_group_work(struct work_struct *work)
409 {
410 	struct amt_group_node *gnode = container_of(to_delayed_work(work),
411 						    struct amt_group_node,
412 						    group_timer);
413 	struct amt_tunnel_list *tunnel = gnode->tunnel_list;
414 	struct amt_dev *amt = gnode->amt;
415 	struct amt_source_node *snode;
416 	bool delete_group = true;
417 	struct hlist_node *t;
418 	int i, buckets;
419 
420 	buckets = amt->hash_buckets;
421 
422 	spin_lock_bh(&tunnel->lock);
423 	if (gnode->filter_mode == MCAST_INCLUDE) {
424 		/* Not Used */
425 		spin_unlock_bh(&tunnel->lock);
426 		goto out;
427 	}
428 
429 	rcu_read_lock();
430 	for (i = 0; i < buckets; i++) {
431 		hlist_for_each_entry_safe(snode, t,
432 					  &gnode->sources[i], node) {
433 			if (!delayed_work_pending(&snode->source_timer) ||
434 			    snode->status == AMT_SOURCE_STATUS_D_FWD) {
435 				amt_destroy_source(snode);
436 			} else {
437 				delete_group = false;
438 				snode->status = AMT_SOURCE_STATUS_FWD;
439 			}
440 		}
441 	}
442 	if (delete_group)
443 		amt_del_group(amt, gnode);
444 	else
445 		gnode->filter_mode = MCAST_INCLUDE;
446 	rcu_read_unlock();
447 	spin_unlock_bh(&tunnel->lock);
448 out:
449 	dev_put(amt->dev);
450 }
451 
452 /* Non-existent group is created as INCLUDE {empty}:
453  *
454  * RFC 3376 - 5.1. Action on Change of Interface State
455  *
456  * If no interface state existed for that multicast address before
457  * the change (i.e., the change consisted of creating a new
458  * per-interface record), or if no state exists after the change
459  * (i.e., the change consisted of deleting a per-interface record),
460  * then the "non-existent" state is considered to have a filter mode
461  * of INCLUDE and an empty source list.
462  */
463 static struct amt_group_node *amt_add_group(struct amt_dev *amt,
464 					    struct amt_tunnel_list *tunnel,
465 					    union amt_addr *group,
466 					    union amt_addr *host,
467 					    bool v6)
468 {
469 	struct amt_group_node *gnode;
470 	u32 hash;
471 	int i;
472 
473 	if (tunnel->nr_groups >= amt->max_groups)
474 		return ERR_PTR(-ENOSPC);
475 
476 	gnode = kzalloc(sizeof(*gnode) +
477 			(sizeof(struct hlist_head) * amt->hash_buckets),
478 			GFP_ATOMIC);
479 	if (unlikely(!gnode))
480 		return ERR_PTR(-ENOMEM);
481 
482 	gnode->amt = amt;
483 	gnode->group_addr = *group;
484 	gnode->host_addr = *host;
485 	gnode->v6 = v6;
486 	gnode->tunnel_list = tunnel;
487 	gnode->filter_mode = MCAST_INCLUDE;
488 	INIT_HLIST_NODE(&gnode->node);
489 	INIT_DELAYED_WORK(&gnode->group_timer, amt_group_work);
490 	for (i = 0; i < amt->hash_buckets; i++)
491 		INIT_HLIST_HEAD(&gnode->sources[i]);
492 
493 	hash = amt_group_hash(tunnel, group);
494 	hlist_add_head_rcu(&gnode->node, &tunnel->groups[hash]);
495 	tunnel->nr_groups++;
496 
497 	if (!gnode->v6)
498 		netdev_dbg(amt->dev, "Join group %pI4\n",
499 			   &gnode->group_addr.ip4);
500 #if IS_ENABLED(CONFIG_IPV6)
501 	else
502 		netdev_dbg(amt->dev, "Join group %pI6\n",
503 			   &gnode->group_addr.ip6);
504 #endif
505 
506 	return gnode;
507 }
508 
509 static struct sk_buff *amt_build_igmp_gq(struct amt_dev *amt)
510 {
511 	u8 ra[AMT_IPHDR_OPTS] = { IPOPT_RA, 4, 0, 0 };
512 	int hlen = LL_RESERVED_SPACE(amt->dev);
513 	int tlen = amt->dev->needed_tailroom;
514 	struct igmpv3_query *ihv3;
515 	void *csum_start = NULL;
516 	__sum16 *csum = NULL;
517 	struct sk_buff *skb;
518 	struct ethhdr *eth;
519 	struct iphdr *iph;
520 	unsigned int len;
521 	int offset;
522 
523 	len = hlen + tlen + sizeof(*iph) + AMT_IPHDR_OPTS + sizeof(*ihv3);
524 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
525 	if (!skb)
526 		return NULL;
527 
528 	skb_reserve(skb, hlen);
529 	skb_push(skb, sizeof(*eth));
530 	skb->protocol = htons(ETH_P_IP);
531 	skb_reset_mac_header(skb);
532 	skb->priority = TC_PRIO_CONTROL;
533 	skb_put(skb, sizeof(*iph));
534 	skb_put_data(skb, ra, sizeof(ra));
535 	skb_put(skb, sizeof(*ihv3));
536 	skb_pull(skb, sizeof(*eth));
537 	skb_reset_network_header(skb);
538 
539 	iph		= ip_hdr(skb);
540 	iph->version	= 4;
541 	iph->ihl	= (sizeof(struct iphdr) + AMT_IPHDR_OPTS) >> 2;
542 	iph->tos	= AMT_TOS;
543 	iph->tot_len	= htons(sizeof(*iph) + AMT_IPHDR_OPTS + sizeof(*ihv3));
544 	iph->frag_off	= htons(IP_DF);
545 	iph->ttl	= 1;
546 	iph->id		= 0;
547 	iph->protocol	= IPPROTO_IGMP;
548 	iph->daddr	= htonl(INADDR_ALLHOSTS_GROUP);
549 	iph->saddr	= htonl(INADDR_ANY);
550 	ip_send_check(iph);
551 
552 	eth = eth_hdr(skb);
553 	ether_addr_copy(eth->h_source, amt->dev->dev_addr);
554 	ip_eth_mc_map(htonl(INADDR_ALLHOSTS_GROUP), eth->h_dest);
555 	eth->h_proto = htons(ETH_P_IP);
556 
557 	ihv3		= skb_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
558 	skb_reset_transport_header(skb);
559 	ihv3->type	= IGMP_HOST_MEMBERSHIP_QUERY;
560 	ihv3->code	= 1;
561 	ihv3->group	= 0;
562 	ihv3->qqic	= amt->qi;
563 	ihv3->nsrcs	= 0;
564 	ihv3->resv	= 0;
565 	ihv3->suppress	= false;
566 	ihv3->qrv	= READ_ONCE(amt->net->ipv4.sysctl_igmp_qrv);
567 	ihv3->csum	= 0;
568 	csum		= &ihv3->csum;
569 	csum_start	= (void *)ihv3;
570 	*csum		= ip_compute_csum(csum_start, sizeof(*ihv3));
571 	offset		= skb_transport_offset(skb);
572 	skb->csum	= skb_checksum(skb, offset, skb->len - offset, 0);
573 	skb->ip_summed	= CHECKSUM_NONE;
574 
575 	skb_push(skb, sizeof(*eth) + sizeof(*iph) + AMT_IPHDR_OPTS);
576 
577 	return skb;
578 }
579 
580 static void amt_update_gw_status(struct amt_dev *amt, enum amt_status status,
581 				 bool validate)
582 {
583 	if (validate && amt->status >= status)
584 		return;
585 	netdev_dbg(amt->dev, "Update GW status %s -> %s",
586 		   status_str[amt->status], status_str[status]);
587 	WRITE_ONCE(amt->status, status);
588 }
589 
590 static void __amt_update_relay_status(struct amt_tunnel_list *tunnel,
591 				      enum amt_status status,
592 				      bool validate)
593 {
594 	if (validate && tunnel->status >= status)
595 		return;
596 	netdev_dbg(tunnel->amt->dev,
597 		   "Update Tunnel(IP = %pI4, PORT = %u) status %s -> %s",
598 		   &tunnel->ip4, ntohs(tunnel->source_port),
599 		   status_str[tunnel->status], status_str[status]);
600 	tunnel->status = status;
601 }
602 
603 static void amt_update_relay_status(struct amt_tunnel_list *tunnel,
604 				    enum amt_status status, bool validate)
605 {
606 	spin_lock_bh(&tunnel->lock);
607 	__amt_update_relay_status(tunnel, status, validate);
608 	spin_unlock_bh(&tunnel->lock);
609 }
610 
611 static void amt_send_discovery(struct amt_dev *amt)
612 {
613 	struct amt_header_discovery *amtd;
614 	int hlen, tlen, offset;
615 	struct socket *sock;
616 	struct udphdr *udph;
617 	struct sk_buff *skb;
618 	struct iphdr *iph;
619 	struct rtable *rt;
620 	struct flowi4 fl4;
621 	u32 len;
622 	int err;
623 
624 	rcu_read_lock();
625 	sock = rcu_dereference(amt->sock);
626 	if (!sock)
627 		goto out;
628 
629 	if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
630 		goto out;
631 
632 	rt = ip_route_output_ports(amt->net, &fl4, sock->sk,
633 				   amt->discovery_ip, amt->local_ip,
634 				   amt->gw_port, amt->relay_port,
635 				   IPPROTO_UDP, 0,
636 				   amt->stream_dev->ifindex);
637 	if (IS_ERR(rt)) {
638 		amt->dev->stats.tx_errors++;
639 		goto out;
640 	}
641 
642 	hlen = LL_RESERVED_SPACE(amt->dev);
643 	tlen = amt->dev->needed_tailroom;
644 	len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amtd);
645 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
646 	if (!skb) {
647 		ip_rt_put(rt);
648 		amt->dev->stats.tx_errors++;
649 		goto out;
650 	}
651 
652 	skb->priority = TC_PRIO_CONTROL;
653 	skb_dst_set(skb, &rt->dst);
654 
655 	len = sizeof(*iph) + sizeof(*udph) + sizeof(*amtd);
656 	skb_reset_network_header(skb);
657 	skb_put(skb, len);
658 	amtd = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
659 	amtd->version	= 0;
660 	amtd->type	= AMT_MSG_DISCOVERY;
661 	amtd->reserved	= 0;
662 	amtd->nonce	= amt->nonce;
663 	skb_push(skb, sizeof(*udph));
664 	skb_reset_transport_header(skb);
665 	udph		= udp_hdr(skb);
666 	udph->source	= amt->gw_port;
667 	udph->dest	= amt->relay_port;
668 	udph->len	= htons(sizeof(*udph) + sizeof(*amtd));
669 	udph->check	= 0;
670 	offset = skb_transport_offset(skb);
671 	skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
672 	udph->check = csum_tcpudp_magic(amt->local_ip, amt->discovery_ip,
673 					sizeof(*udph) + sizeof(*amtd),
674 					IPPROTO_UDP, skb->csum);
675 
676 	skb_push(skb, sizeof(*iph));
677 	iph		= ip_hdr(skb);
678 	iph->version	= 4;
679 	iph->ihl	= (sizeof(struct iphdr)) >> 2;
680 	iph->tos	= AMT_TOS;
681 	iph->frag_off	= 0;
682 	iph->ttl	= ip4_dst_hoplimit(&rt->dst);
683 	iph->daddr	= amt->discovery_ip;
684 	iph->saddr	= amt->local_ip;
685 	iph->protocol	= IPPROTO_UDP;
686 	iph->tot_len	= htons(len);
687 
688 	skb->ip_summed = CHECKSUM_NONE;
689 	ip_select_ident(amt->net, skb, NULL);
690 	ip_send_check(iph);
691 	err = ip_local_out(amt->net, sock->sk, skb);
692 	if (unlikely(net_xmit_eval(err)))
693 		amt->dev->stats.tx_errors++;
694 
695 	amt_update_gw_status(amt, AMT_STATUS_SENT_DISCOVERY, true);
696 out:
697 	rcu_read_unlock();
698 }
699 
700 static void amt_send_request(struct amt_dev *amt, bool v6)
701 {
702 	struct amt_header_request *amtrh;
703 	int hlen, tlen, offset;
704 	struct socket *sock;
705 	struct udphdr *udph;
706 	struct sk_buff *skb;
707 	struct iphdr *iph;
708 	struct rtable *rt;
709 	struct flowi4 fl4;
710 	u32 len;
711 	int err;
712 
713 	rcu_read_lock();
714 	sock = rcu_dereference(amt->sock);
715 	if (!sock)
716 		goto out;
717 
718 	if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
719 		goto out;
720 
721 	rt = ip_route_output_ports(amt->net, &fl4, sock->sk,
722 				   amt->remote_ip, amt->local_ip,
723 				   amt->gw_port, amt->relay_port,
724 				   IPPROTO_UDP, 0,
725 				   amt->stream_dev->ifindex);
726 	if (IS_ERR(rt)) {
727 		amt->dev->stats.tx_errors++;
728 		goto out;
729 	}
730 
731 	hlen = LL_RESERVED_SPACE(amt->dev);
732 	tlen = amt->dev->needed_tailroom;
733 	len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amtrh);
734 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
735 	if (!skb) {
736 		ip_rt_put(rt);
737 		amt->dev->stats.tx_errors++;
738 		goto out;
739 	}
740 
741 	skb->priority = TC_PRIO_CONTROL;
742 	skb_dst_set(skb, &rt->dst);
743 
744 	len = sizeof(*iph) + sizeof(*udph) + sizeof(*amtrh);
745 	skb_reset_network_header(skb);
746 	skb_put(skb, len);
747 	amtrh = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
748 	amtrh->version	 = 0;
749 	amtrh->type	 = AMT_MSG_REQUEST;
750 	amtrh->reserved1 = 0;
751 	amtrh->p	 = v6;
752 	amtrh->reserved2 = 0;
753 	amtrh->nonce	 = amt->nonce;
754 	skb_push(skb, sizeof(*udph));
755 	skb_reset_transport_header(skb);
756 	udph		= udp_hdr(skb);
757 	udph->source	= amt->gw_port;
758 	udph->dest	= amt->relay_port;
759 	udph->len	= htons(sizeof(*amtrh) + sizeof(*udph));
760 	udph->check	= 0;
761 	offset = skb_transport_offset(skb);
762 	skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
763 	udph->check = csum_tcpudp_magic(amt->local_ip, amt->remote_ip,
764 					sizeof(*udph) + sizeof(*amtrh),
765 					IPPROTO_UDP, skb->csum);
766 
767 	skb_push(skb, sizeof(*iph));
768 	iph		= ip_hdr(skb);
769 	iph->version	= 4;
770 	iph->ihl	= (sizeof(struct iphdr)) >> 2;
771 	iph->tos	= AMT_TOS;
772 	iph->frag_off	= 0;
773 	iph->ttl	= ip4_dst_hoplimit(&rt->dst);
774 	iph->daddr	= amt->remote_ip;
775 	iph->saddr	= amt->local_ip;
776 	iph->protocol	= IPPROTO_UDP;
777 	iph->tot_len	= htons(len);
778 
779 	skb->ip_summed = CHECKSUM_NONE;
780 	ip_select_ident(amt->net, skb, NULL);
781 	ip_send_check(iph);
782 	err = ip_local_out(amt->net, sock->sk, skb);
783 	if (unlikely(net_xmit_eval(err)))
784 		amt->dev->stats.tx_errors++;
785 
786 out:
787 	rcu_read_unlock();
788 }
789 
790 static void amt_send_igmp_gq(struct amt_dev *amt,
791 			     struct amt_tunnel_list *tunnel)
792 {
793 	struct sk_buff *skb;
794 
795 	skb = amt_build_igmp_gq(amt);
796 	if (!skb)
797 		return;
798 
799 	amt_skb_cb(skb)->tunnel = tunnel;
800 	dev_queue_xmit(skb);
801 }
802 
803 #if IS_ENABLED(CONFIG_IPV6)
804 static struct sk_buff *amt_build_mld_gq(struct amt_dev *amt)
805 {
806 	u8 ra[AMT_IP6HDR_OPTS] = { IPPROTO_ICMPV6, 0, IPV6_TLV_ROUTERALERT,
807 				   2, 0, 0, IPV6_TLV_PAD1, IPV6_TLV_PAD1 };
808 	int hlen = LL_RESERVED_SPACE(amt->dev);
809 	int tlen = amt->dev->needed_tailroom;
810 	struct mld2_query *mld2q;
811 	void *csum_start = NULL;
812 	struct ipv6hdr *ip6h;
813 	struct sk_buff *skb;
814 	struct ethhdr *eth;
815 	u32 len;
816 
817 	len = hlen + tlen + sizeof(*ip6h) + sizeof(ra) + sizeof(*mld2q);
818 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
819 	if (!skb)
820 		return NULL;
821 
822 	skb_reserve(skb, hlen);
823 	skb_push(skb, sizeof(*eth));
824 	skb_reset_mac_header(skb);
825 	eth = eth_hdr(skb);
826 	skb->priority = TC_PRIO_CONTROL;
827 	skb->protocol = htons(ETH_P_IPV6);
828 	skb_put_zero(skb, sizeof(*ip6h));
829 	skb_put_data(skb, ra, sizeof(ra));
830 	skb_put_zero(skb, sizeof(*mld2q));
831 	skb_pull(skb, sizeof(*eth));
832 	skb_reset_network_header(skb);
833 	ip6h			= ipv6_hdr(skb);
834 	ip6h->payload_len	= htons(sizeof(ra) + sizeof(*mld2q));
835 	ip6h->nexthdr		= NEXTHDR_HOP;
836 	ip6h->hop_limit		= 1;
837 	ip6h->daddr		= mld2_all_node;
838 	ip6_flow_hdr(ip6h, 0, 0);
839 
840 	if (ipv6_dev_get_saddr(amt->net, amt->dev, &ip6h->daddr, 0,
841 			       &ip6h->saddr)) {
842 		amt->dev->stats.tx_errors++;
843 		kfree_skb(skb);
844 		return NULL;
845 	}
846 
847 	eth->h_proto = htons(ETH_P_IPV6);
848 	ether_addr_copy(eth->h_source, amt->dev->dev_addr);
849 	ipv6_eth_mc_map(&mld2_all_node, eth->h_dest);
850 
851 	skb_pull(skb, sizeof(*ip6h) + sizeof(ra));
852 	skb_reset_transport_header(skb);
853 	mld2q			= (struct mld2_query *)icmp6_hdr(skb);
854 	mld2q->mld2q_mrc	= htons(1);
855 	mld2q->mld2q_type	= ICMPV6_MGM_QUERY;
856 	mld2q->mld2q_code	= 0;
857 	mld2q->mld2q_cksum	= 0;
858 	mld2q->mld2q_resv1	= 0;
859 	mld2q->mld2q_resv2	= 0;
860 	mld2q->mld2q_suppress	= 0;
861 	mld2q->mld2q_qrv	= amt->qrv;
862 	mld2q->mld2q_nsrcs	= 0;
863 	mld2q->mld2q_qqic	= amt->qi;
864 	csum_start		= (void *)mld2q;
865 	mld2q->mld2q_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
866 					     sizeof(*mld2q),
867 					     IPPROTO_ICMPV6,
868 					     csum_partial(csum_start,
869 							  sizeof(*mld2q), 0));
870 
871 	skb->ip_summed = CHECKSUM_NONE;
872 	skb_push(skb, sizeof(*eth) + sizeof(*ip6h) + sizeof(ra));
873 	return skb;
874 }
875 
876 static void amt_send_mld_gq(struct amt_dev *amt, struct amt_tunnel_list *tunnel)
877 {
878 	struct sk_buff *skb;
879 
880 	skb = amt_build_mld_gq(amt);
881 	if (!skb)
882 		return;
883 
884 	amt_skb_cb(skb)->tunnel = tunnel;
885 	dev_queue_xmit(skb);
886 }
887 #else
888 static void amt_send_mld_gq(struct amt_dev *amt, struct amt_tunnel_list *tunnel)
889 {
890 }
891 #endif
892 
893 static bool amt_queue_event(struct amt_dev *amt, enum amt_event event,
894 			    struct sk_buff *skb)
895 {
896 	int index;
897 
898 	spin_lock_bh(&amt->lock);
899 	if (amt->nr_events >= AMT_MAX_EVENTS) {
900 		spin_unlock_bh(&amt->lock);
901 		return 1;
902 	}
903 
904 	index = (amt->event_idx + amt->nr_events) % AMT_MAX_EVENTS;
905 	amt->events[index].event = event;
906 	amt->events[index].skb = skb;
907 	amt->nr_events++;
908 	amt->event_idx %= AMT_MAX_EVENTS;
909 	queue_work(amt_wq, &amt->event_wq);
910 	spin_unlock_bh(&amt->lock);
911 
912 	return 0;
913 }
914 
915 static void amt_secret_work(struct work_struct *work)
916 {
917 	struct amt_dev *amt = container_of(to_delayed_work(work),
918 					   struct amt_dev,
919 					   secret_wq);
920 
921 	spin_lock_bh(&amt->lock);
922 	get_random_bytes(&amt->key, sizeof(siphash_key_t));
923 	spin_unlock_bh(&amt->lock);
924 	mod_delayed_work(amt_wq, &amt->secret_wq,
925 			 msecs_to_jiffies(AMT_SECRET_TIMEOUT));
926 }
927 
928 static void amt_event_send_discovery(struct amt_dev *amt)
929 {
930 	if (amt->status > AMT_STATUS_SENT_DISCOVERY)
931 		goto out;
932 	get_random_bytes(&amt->nonce, sizeof(__be32));
933 
934 	amt_send_discovery(amt);
935 out:
936 	mod_delayed_work(amt_wq, &amt->discovery_wq,
937 			 msecs_to_jiffies(AMT_DISCOVERY_TIMEOUT));
938 }
939 
940 static void amt_discovery_work(struct work_struct *work)
941 {
942 	struct amt_dev *amt = container_of(to_delayed_work(work),
943 					   struct amt_dev,
944 					   discovery_wq);
945 
946 	if (amt_queue_event(amt, AMT_EVENT_SEND_DISCOVERY, NULL))
947 		mod_delayed_work(amt_wq, &amt->discovery_wq,
948 				 msecs_to_jiffies(AMT_DISCOVERY_TIMEOUT));
949 }
950 
951 static void amt_event_send_request(struct amt_dev *amt)
952 {
953 	u32 exp;
954 
955 	if (amt->status < AMT_STATUS_RECEIVED_ADVERTISEMENT)
956 		goto out;
957 
958 	if (amt->req_cnt > AMT_MAX_REQ_COUNT) {
959 		netdev_dbg(amt->dev, "Gateway is not ready");
960 		amt->qi = AMT_INIT_REQ_TIMEOUT;
961 		WRITE_ONCE(amt->ready4, false);
962 		WRITE_ONCE(amt->ready6, false);
963 		amt->remote_ip = 0;
964 		amt_update_gw_status(amt, AMT_STATUS_INIT, false);
965 		amt->req_cnt = 0;
966 		amt->nonce = 0;
967 		goto out;
968 	}
969 
970 	if (!amt->req_cnt) {
971 		WRITE_ONCE(amt->ready4, false);
972 		WRITE_ONCE(amt->ready6, false);
973 		get_random_bytes(&amt->nonce, sizeof(__be32));
974 	}
975 
976 	amt_send_request(amt, false);
977 	amt_send_request(amt, true);
978 	amt_update_gw_status(amt, AMT_STATUS_SENT_REQUEST, true);
979 	amt->req_cnt++;
980 out:
981 	exp = min_t(u32, (1 * (1 << amt->req_cnt)), AMT_MAX_REQ_TIMEOUT);
982 	mod_delayed_work(amt_wq, &amt->req_wq, msecs_to_jiffies(exp * 1000));
983 }
984 
985 static void amt_req_work(struct work_struct *work)
986 {
987 	struct amt_dev *amt = container_of(to_delayed_work(work),
988 					   struct amt_dev,
989 					   req_wq);
990 
991 	if (amt_queue_event(amt, AMT_EVENT_SEND_REQUEST, NULL))
992 		mod_delayed_work(amt_wq, &amt->req_wq,
993 				 msecs_to_jiffies(100));
994 }
995 
996 static bool amt_send_membership_update(struct amt_dev *amt,
997 				       struct sk_buff *skb,
998 				       bool v6)
999 {
1000 	struct amt_header_membership_update *amtmu;
1001 	struct socket *sock;
1002 	struct iphdr *iph;
1003 	struct flowi4 fl4;
1004 	struct rtable *rt;
1005 	int err;
1006 
1007 	sock = rcu_dereference_bh(amt->sock);
1008 	if (!sock)
1009 		return true;
1010 
1011 	err = skb_cow_head(skb, LL_RESERVED_SPACE(amt->dev) + sizeof(*amtmu) +
1012 			   sizeof(*iph) + sizeof(struct udphdr));
1013 	if (err)
1014 		return true;
1015 
1016 	skb_reset_inner_headers(skb);
1017 	memset(&fl4, 0, sizeof(struct flowi4));
1018 	fl4.flowi4_oif         = amt->stream_dev->ifindex;
1019 	fl4.daddr              = amt->remote_ip;
1020 	fl4.saddr              = amt->local_ip;
1021 	fl4.flowi4_tos         = AMT_TOS;
1022 	fl4.flowi4_proto       = IPPROTO_UDP;
1023 	rt = ip_route_output_key(amt->net, &fl4);
1024 	if (IS_ERR(rt)) {
1025 		netdev_dbg(amt->dev, "no route to %pI4\n", &amt->remote_ip);
1026 		return true;
1027 	}
1028 
1029 	amtmu			= skb_push(skb, sizeof(*amtmu));
1030 	amtmu->version		= 0;
1031 	amtmu->type		= AMT_MSG_MEMBERSHIP_UPDATE;
1032 	amtmu->reserved		= 0;
1033 	amtmu->nonce		= amt->nonce;
1034 	amtmu->response_mac	= amt->mac;
1035 
1036 	if (!v6)
1037 		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1038 	else
1039 		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1040 	udp_tunnel_xmit_skb(rt, sock->sk, skb,
1041 			    fl4.saddr,
1042 			    fl4.daddr,
1043 			    AMT_TOS,
1044 			    ip4_dst_hoplimit(&rt->dst),
1045 			    0,
1046 			    amt->gw_port,
1047 			    amt->relay_port,
1048 			    false,
1049 			    false);
1050 	amt_update_gw_status(amt, AMT_STATUS_SENT_UPDATE, true);
1051 	return false;
1052 }
1053 
1054 static void amt_send_multicast_data(struct amt_dev *amt,
1055 				    const struct sk_buff *oskb,
1056 				    struct amt_tunnel_list *tunnel,
1057 				    bool v6)
1058 {
1059 	struct amt_header_mcast_data *amtmd;
1060 	struct socket *sock;
1061 	struct sk_buff *skb;
1062 	struct iphdr *iph;
1063 	struct flowi4 fl4;
1064 	struct rtable *rt;
1065 
1066 	sock = rcu_dereference_bh(amt->sock);
1067 	if (!sock)
1068 		return;
1069 
1070 	skb = skb_copy_expand(oskb, sizeof(*amtmd) + sizeof(*iph) +
1071 			      sizeof(struct udphdr), 0, GFP_ATOMIC);
1072 	if (!skb)
1073 		return;
1074 
1075 	skb_reset_inner_headers(skb);
1076 	memset(&fl4, 0, sizeof(struct flowi4));
1077 	fl4.flowi4_oif         = amt->stream_dev->ifindex;
1078 	fl4.daddr              = tunnel->ip4;
1079 	fl4.saddr              = amt->local_ip;
1080 	fl4.flowi4_proto       = IPPROTO_UDP;
1081 	rt = ip_route_output_key(amt->net, &fl4);
1082 	if (IS_ERR(rt)) {
1083 		netdev_dbg(amt->dev, "no route to %pI4\n", &tunnel->ip4);
1084 		kfree_skb(skb);
1085 		return;
1086 	}
1087 
1088 	amtmd = skb_push(skb, sizeof(*amtmd));
1089 	amtmd->version = 0;
1090 	amtmd->reserved = 0;
1091 	amtmd->type = AMT_MSG_MULTICAST_DATA;
1092 
1093 	if (!v6)
1094 		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1095 	else
1096 		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1097 	udp_tunnel_xmit_skb(rt, sock->sk, skb,
1098 			    fl4.saddr,
1099 			    fl4.daddr,
1100 			    AMT_TOS,
1101 			    ip4_dst_hoplimit(&rt->dst),
1102 			    0,
1103 			    amt->relay_port,
1104 			    tunnel->source_port,
1105 			    false,
1106 			    false);
1107 }
1108 
1109 static bool amt_send_membership_query(struct amt_dev *amt,
1110 				      struct sk_buff *skb,
1111 				      struct amt_tunnel_list *tunnel,
1112 				      bool v6)
1113 {
1114 	struct amt_header_membership_query *amtmq;
1115 	struct socket *sock;
1116 	struct rtable *rt;
1117 	struct flowi4 fl4;
1118 	int err;
1119 
1120 	sock = rcu_dereference_bh(amt->sock);
1121 	if (!sock)
1122 		return true;
1123 
1124 	err = skb_cow_head(skb, LL_RESERVED_SPACE(amt->dev) + sizeof(*amtmq) +
1125 			   sizeof(struct iphdr) + sizeof(struct udphdr));
1126 	if (err)
1127 		return true;
1128 
1129 	skb_reset_inner_headers(skb);
1130 	memset(&fl4, 0, sizeof(struct flowi4));
1131 	fl4.flowi4_oif         = amt->stream_dev->ifindex;
1132 	fl4.daddr              = tunnel->ip4;
1133 	fl4.saddr              = amt->local_ip;
1134 	fl4.flowi4_tos         = AMT_TOS;
1135 	fl4.flowi4_proto       = IPPROTO_UDP;
1136 	rt = ip_route_output_key(amt->net, &fl4);
1137 	if (IS_ERR(rt)) {
1138 		netdev_dbg(amt->dev, "no route to %pI4\n", &tunnel->ip4);
1139 		return true;
1140 	}
1141 
1142 	amtmq		= skb_push(skb, sizeof(*amtmq));
1143 	amtmq->version	= 0;
1144 	amtmq->type	= AMT_MSG_MEMBERSHIP_QUERY;
1145 	amtmq->reserved = 0;
1146 	amtmq->l	= 0;
1147 	amtmq->g	= 0;
1148 	amtmq->nonce	= tunnel->nonce;
1149 	amtmq->response_mac = tunnel->mac;
1150 
1151 	if (!v6)
1152 		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1153 	else
1154 		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1155 	udp_tunnel_xmit_skb(rt, sock->sk, skb,
1156 			    fl4.saddr,
1157 			    fl4.daddr,
1158 			    AMT_TOS,
1159 			    ip4_dst_hoplimit(&rt->dst),
1160 			    0,
1161 			    amt->relay_port,
1162 			    tunnel->source_port,
1163 			    false,
1164 			    false);
1165 	amt_update_relay_status(tunnel, AMT_STATUS_SENT_QUERY, true);
1166 	return false;
1167 }
1168 
1169 static netdev_tx_t amt_dev_xmit(struct sk_buff *skb, struct net_device *dev)
1170 {
1171 	struct amt_dev *amt = netdev_priv(dev);
1172 	struct amt_tunnel_list *tunnel;
1173 	struct amt_group_node *gnode;
1174 	union amt_addr group = {0,};
1175 #if IS_ENABLED(CONFIG_IPV6)
1176 	struct ipv6hdr *ip6h;
1177 	struct mld_msg *mld;
1178 #endif
1179 	bool report = false;
1180 	struct igmphdr *ih;
1181 	bool query = false;
1182 	struct iphdr *iph;
1183 	bool data = false;
1184 	bool v6 = false;
1185 	u32 hash;
1186 
1187 	iph = ip_hdr(skb);
1188 	if (iph->version == 4) {
1189 		if (!ipv4_is_multicast(iph->daddr))
1190 			goto free;
1191 
1192 		if (!ip_mc_check_igmp(skb)) {
1193 			ih = igmp_hdr(skb);
1194 			switch (ih->type) {
1195 			case IGMPV3_HOST_MEMBERSHIP_REPORT:
1196 			case IGMP_HOST_MEMBERSHIP_REPORT:
1197 				report = true;
1198 				break;
1199 			case IGMP_HOST_MEMBERSHIP_QUERY:
1200 				query = true;
1201 				break;
1202 			default:
1203 				goto free;
1204 			}
1205 		} else {
1206 			data = true;
1207 		}
1208 		v6 = false;
1209 		group.ip4 = iph->daddr;
1210 #if IS_ENABLED(CONFIG_IPV6)
1211 	} else if (iph->version == 6) {
1212 		ip6h = ipv6_hdr(skb);
1213 		if (!ipv6_addr_is_multicast(&ip6h->daddr))
1214 			goto free;
1215 
1216 		if (!ipv6_mc_check_mld(skb)) {
1217 			mld = (struct mld_msg *)skb_transport_header(skb);
1218 			switch (mld->mld_type) {
1219 			case ICMPV6_MGM_REPORT:
1220 			case ICMPV6_MLD2_REPORT:
1221 				report = true;
1222 				break;
1223 			case ICMPV6_MGM_QUERY:
1224 				query = true;
1225 				break;
1226 			default:
1227 				goto free;
1228 			}
1229 		} else {
1230 			data = true;
1231 		}
1232 		v6 = true;
1233 		group.ip6 = ip6h->daddr;
1234 #endif
1235 	} else {
1236 		dev->stats.tx_errors++;
1237 		goto free;
1238 	}
1239 
1240 	if (!pskb_may_pull(skb, sizeof(struct ethhdr)))
1241 		goto free;
1242 
1243 	skb_pull(skb, sizeof(struct ethhdr));
1244 
1245 	if (amt->mode == AMT_MODE_GATEWAY) {
1246 		/* Gateway only passes IGMP/MLD packets */
1247 		if (!report)
1248 			goto free;
1249 		if ((!v6 && !READ_ONCE(amt->ready4)) ||
1250 		    (v6 && !READ_ONCE(amt->ready6)))
1251 			goto free;
1252 		if (amt_send_membership_update(amt, skb,  v6))
1253 			goto free;
1254 		goto unlock;
1255 	} else if (amt->mode == AMT_MODE_RELAY) {
1256 		if (query) {
1257 			tunnel = amt_skb_cb(skb)->tunnel;
1258 			if (!tunnel) {
1259 				WARN_ON(1);
1260 				goto free;
1261 			}
1262 
1263 			/* Do not forward unexpected query */
1264 			if (amt_send_membership_query(amt, skb, tunnel, v6))
1265 				goto free;
1266 			goto unlock;
1267 		}
1268 
1269 		if (!data)
1270 			goto free;
1271 		list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list) {
1272 			hash = amt_group_hash(tunnel, &group);
1273 			hlist_for_each_entry_rcu(gnode, &tunnel->groups[hash],
1274 						 node) {
1275 				if (!v6) {
1276 					if (gnode->group_addr.ip4 == iph->daddr)
1277 						goto found;
1278 #if IS_ENABLED(CONFIG_IPV6)
1279 				} else {
1280 					if (ipv6_addr_equal(&gnode->group_addr.ip6,
1281 							    &ip6h->daddr))
1282 						goto found;
1283 #endif
1284 				}
1285 			}
1286 			continue;
1287 found:
1288 			amt_send_multicast_data(amt, skb, tunnel, v6);
1289 		}
1290 	}
1291 
1292 	dev_kfree_skb(skb);
1293 	return NETDEV_TX_OK;
1294 free:
1295 	dev_kfree_skb(skb);
1296 unlock:
1297 	dev->stats.tx_dropped++;
1298 	return NETDEV_TX_OK;
1299 }
1300 
1301 static int amt_parse_type(struct sk_buff *skb)
1302 {
1303 	struct amt_header *amth;
1304 
1305 	if (!pskb_may_pull(skb, sizeof(struct udphdr) +
1306 			   sizeof(struct amt_header)))
1307 		return -1;
1308 
1309 	amth = (struct amt_header *)(udp_hdr(skb) + 1);
1310 
1311 	if (amth->version != 0)
1312 		return -1;
1313 
1314 	if (amth->type >= __AMT_MSG_MAX || !amth->type)
1315 		return -1;
1316 	return amth->type;
1317 }
1318 
1319 static void amt_clear_groups(struct amt_tunnel_list *tunnel)
1320 {
1321 	struct amt_dev *amt = tunnel->amt;
1322 	struct amt_group_node *gnode;
1323 	struct hlist_node *t;
1324 	int i;
1325 
1326 	spin_lock_bh(&tunnel->lock);
1327 	rcu_read_lock();
1328 	for (i = 0; i < amt->hash_buckets; i++)
1329 		hlist_for_each_entry_safe(gnode, t, &tunnel->groups[i], node)
1330 			amt_del_group(amt, gnode);
1331 	rcu_read_unlock();
1332 	spin_unlock_bh(&tunnel->lock);
1333 }
1334 
1335 static void amt_tunnel_expire(struct work_struct *work)
1336 {
1337 	struct amt_tunnel_list *tunnel = container_of(to_delayed_work(work),
1338 						      struct amt_tunnel_list,
1339 						      gc_wq);
1340 	struct amt_dev *amt = tunnel->amt;
1341 
1342 	spin_lock_bh(&amt->lock);
1343 	rcu_read_lock();
1344 	list_del_rcu(&tunnel->list);
1345 	amt->nr_tunnels--;
1346 	amt_clear_groups(tunnel);
1347 	rcu_read_unlock();
1348 	spin_unlock_bh(&amt->lock);
1349 	kfree_rcu(tunnel, rcu);
1350 }
1351 
1352 static void amt_cleanup_srcs(struct amt_dev *amt,
1353 			     struct amt_tunnel_list *tunnel,
1354 			     struct amt_group_node *gnode)
1355 {
1356 	struct amt_source_node *snode;
1357 	struct hlist_node *t;
1358 	int i;
1359 
1360 	/* Delete old sources */
1361 	for (i = 0; i < amt->hash_buckets; i++) {
1362 		hlist_for_each_entry_safe(snode, t, &gnode->sources[i], node) {
1363 			if (snode->flags == AMT_SOURCE_OLD)
1364 				amt_destroy_source(snode);
1365 		}
1366 	}
1367 
1368 	/* switch from new to old */
1369 	for (i = 0; i < amt->hash_buckets; i++)  {
1370 		hlist_for_each_entry_rcu(snode, &gnode->sources[i], node) {
1371 			snode->flags = AMT_SOURCE_OLD;
1372 			if (!gnode->v6)
1373 				netdev_dbg(snode->gnode->amt->dev,
1374 					   "Add source as OLD %pI4 from %pI4\n",
1375 					   &snode->source_addr.ip4,
1376 					   &gnode->group_addr.ip4);
1377 #if IS_ENABLED(CONFIG_IPV6)
1378 			else
1379 				netdev_dbg(snode->gnode->amt->dev,
1380 					   "Add source as OLD %pI6 from %pI6\n",
1381 					   &snode->source_addr.ip6,
1382 					   &gnode->group_addr.ip6);
1383 #endif
1384 		}
1385 	}
1386 }
1387 
1388 static void amt_add_srcs(struct amt_dev *amt, struct amt_tunnel_list *tunnel,
1389 			 struct amt_group_node *gnode, void *grec,
1390 			 bool v6)
1391 {
1392 	struct igmpv3_grec *igmp_grec;
1393 	struct amt_source_node *snode;
1394 #if IS_ENABLED(CONFIG_IPV6)
1395 	struct mld2_grec *mld_grec;
1396 #endif
1397 	union amt_addr src = {0,};
1398 	u16 nsrcs;
1399 	u32 hash;
1400 	int i;
1401 
1402 	if (!v6) {
1403 		igmp_grec = grec;
1404 		nsrcs = ntohs(igmp_grec->grec_nsrcs);
1405 	} else {
1406 #if IS_ENABLED(CONFIG_IPV6)
1407 		mld_grec = grec;
1408 		nsrcs = ntohs(mld_grec->grec_nsrcs);
1409 #else
1410 	return;
1411 #endif
1412 	}
1413 	for (i = 0; i < nsrcs; i++) {
1414 		if (tunnel->nr_sources >= amt->max_sources)
1415 			return;
1416 		if (!v6)
1417 			src.ip4 = igmp_grec->grec_src[i];
1418 #if IS_ENABLED(CONFIG_IPV6)
1419 		else
1420 			memcpy(&src.ip6, &mld_grec->grec_src[i],
1421 			       sizeof(struct in6_addr));
1422 #endif
1423 		if (amt_lookup_src(tunnel, gnode, AMT_FILTER_ALL, &src))
1424 			continue;
1425 
1426 		snode = amt_alloc_snode(gnode, &src);
1427 		if (snode) {
1428 			hash = amt_source_hash(tunnel, &snode->source_addr);
1429 			hlist_add_head_rcu(&snode->node, &gnode->sources[hash]);
1430 			tunnel->nr_sources++;
1431 			gnode->nr_sources++;
1432 
1433 			if (!gnode->v6)
1434 				netdev_dbg(snode->gnode->amt->dev,
1435 					   "Add source as NEW %pI4 from %pI4\n",
1436 					   &snode->source_addr.ip4,
1437 					   &gnode->group_addr.ip4);
1438 #if IS_ENABLED(CONFIG_IPV6)
1439 			else
1440 				netdev_dbg(snode->gnode->amt->dev,
1441 					   "Add source as NEW %pI6 from %pI6\n",
1442 					   &snode->source_addr.ip6,
1443 					   &gnode->group_addr.ip6);
1444 #endif
1445 		}
1446 	}
1447 }
1448 
1449 /* Router State   Report Rec'd New Router State
1450  * ------------   ------------ ----------------
1451  * EXCLUDE (X,Y)  IS_IN (A)    EXCLUDE (X+A,Y-A)
1452  *
1453  * -----------+-----------+-----------+
1454  *            |    OLD    |    NEW    |
1455  * -----------+-----------+-----------+
1456  *    FWD     |     X     |    X+A    |
1457  * -----------+-----------+-----------+
1458  *    D_FWD   |     Y     |    Y-A    |
1459  * -----------+-----------+-----------+
1460  *    NONE    |           |     A     |
1461  * -----------+-----------+-----------+
1462  *
1463  * a) Received sources are NONE/NEW
1464  * b) All NONE will be deleted by amt_cleanup_srcs().
1465  * c) All OLD will be deleted by amt_cleanup_srcs().
1466  * d) After delete, NEW source will be switched to OLD.
1467  */
1468 static void amt_lookup_act_srcs(struct amt_tunnel_list *tunnel,
1469 				struct amt_group_node *gnode,
1470 				void *grec,
1471 				enum amt_ops ops,
1472 				enum amt_filter filter,
1473 				enum amt_act act,
1474 				bool v6)
1475 {
1476 	struct amt_dev *amt = tunnel->amt;
1477 	struct amt_source_node *snode;
1478 	struct igmpv3_grec *igmp_grec;
1479 #if IS_ENABLED(CONFIG_IPV6)
1480 	struct mld2_grec *mld_grec;
1481 #endif
1482 	union amt_addr src = {0,};
1483 	struct hlist_node *t;
1484 	u16 nsrcs;
1485 	int i, j;
1486 
1487 	if (!v6) {
1488 		igmp_grec = grec;
1489 		nsrcs = ntohs(igmp_grec->grec_nsrcs);
1490 	} else {
1491 #if IS_ENABLED(CONFIG_IPV6)
1492 		mld_grec = grec;
1493 		nsrcs = ntohs(mld_grec->grec_nsrcs);
1494 #else
1495 	return;
1496 #endif
1497 	}
1498 
1499 	memset(&src, 0, sizeof(union amt_addr));
1500 	switch (ops) {
1501 	case AMT_OPS_INT:
1502 		/* A*B */
1503 		for (i = 0; i < nsrcs; i++) {
1504 			if (!v6)
1505 				src.ip4 = igmp_grec->grec_src[i];
1506 #if IS_ENABLED(CONFIG_IPV6)
1507 			else
1508 				memcpy(&src.ip6, &mld_grec->grec_src[i],
1509 				       sizeof(struct in6_addr));
1510 #endif
1511 			snode = amt_lookup_src(tunnel, gnode, filter, &src);
1512 			if (!snode)
1513 				continue;
1514 			amt_act_src(tunnel, gnode, snode, act);
1515 		}
1516 		break;
1517 	case AMT_OPS_UNI:
1518 		/* A+B */
1519 		for (i = 0; i < amt->hash_buckets; i++) {
1520 			hlist_for_each_entry_safe(snode, t, &gnode->sources[i],
1521 						  node) {
1522 				if (amt_status_filter(snode, filter))
1523 					amt_act_src(tunnel, gnode, snode, act);
1524 			}
1525 		}
1526 		for (i = 0; i < nsrcs; i++) {
1527 			if (!v6)
1528 				src.ip4 = igmp_grec->grec_src[i];
1529 #if IS_ENABLED(CONFIG_IPV6)
1530 			else
1531 				memcpy(&src.ip6, &mld_grec->grec_src[i],
1532 				       sizeof(struct in6_addr));
1533 #endif
1534 			snode = amt_lookup_src(tunnel, gnode, filter, &src);
1535 			if (!snode)
1536 				continue;
1537 			amt_act_src(tunnel, gnode, snode, act);
1538 		}
1539 		break;
1540 	case AMT_OPS_SUB:
1541 		/* A-B */
1542 		for (i = 0; i < amt->hash_buckets; i++) {
1543 			hlist_for_each_entry_safe(snode, t, &gnode->sources[i],
1544 						  node) {
1545 				if (!amt_status_filter(snode, filter))
1546 					continue;
1547 				for (j = 0; j < nsrcs; j++) {
1548 					if (!v6)
1549 						src.ip4 = igmp_grec->grec_src[j];
1550 #if IS_ENABLED(CONFIG_IPV6)
1551 					else
1552 						memcpy(&src.ip6,
1553 						       &mld_grec->grec_src[j],
1554 						       sizeof(struct in6_addr));
1555 #endif
1556 					if (amt_addr_equal(&snode->source_addr,
1557 							   &src))
1558 						goto out_sub;
1559 				}
1560 				amt_act_src(tunnel, gnode, snode, act);
1561 				continue;
1562 out_sub:;
1563 			}
1564 		}
1565 		break;
1566 	case AMT_OPS_SUB_REV:
1567 		/* B-A */
1568 		for (i = 0; i < nsrcs; i++) {
1569 			if (!v6)
1570 				src.ip4 = igmp_grec->grec_src[i];
1571 #if IS_ENABLED(CONFIG_IPV6)
1572 			else
1573 				memcpy(&src.ip6, &mld_grec->grec_src[i],
1574 				       sizeof(struct in6_addr));
1575 #endif
1576 			snode = amt_lookup_src(tunnel, gnode, AMT_FILTER_ALL,
1577 					       &src);
1578 			if (!snode) {
1579 				snode = amt_lookup_src(tunnel, gnode,
1580 						       filter, &src);
1581 				if (snode)
1582 					amt_act_src(tunnel, gnode, snode, act);
1583 			}
1584 		}
1585 		break;
1586 	default:
1587 		netdev_dbg(amt->dev, "Invalid type\n");
1588 		return;
1589 	}
1590 }
1591 
1592 static void amt_mcast_is_in_handler(struct amt_dev *amt,
1593 				    struct amt_tunnel_list *tunnel,
1594 				    struct amt_group_node *gnode,
1595 				    void *grec, void *zero_grec, bool v6)
1596 {
1597 	if (gnode->filter_mode == MCAST_INCLUDE) {
1598 /* Router State   Report Rec'd New Router State        Actions
1599  * ------------   ------------ ----------------        -------
1600  * INCLUDE (A)    IS_IN (B)    INCLUDE (A+B)           (B)=GMI
1601  */
1602 		/* Update IS_IN (B) as FWD/NEW */
1603 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1604 				    AMT_FILTER_NONE_NEW,
1605 				    AMT_ACT_STATUS_FWD_NEW,
1606 				    v6);
1607 		/* Update INCLUDE (A) as NEW */
1608 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1609 				    AMT_FILTER_FWD,
1610 				    AMT_ACT_STATUS_FWD_NEW,
1611 				    v6);
1612 		/* (B)=GMI */
1613 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1614 				    AMT_FILTER_FWD_NEW,
1615 				    AMT_ACT_GMI,
1616 				    v6);
1617 	} else {
1618 /* State        Actions
1619  * ------------   ------------ ----------------        -------
1620  * EXCLUDE (X,Y)  IS_IN (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1621  */
1622 		/* Update (A) in (X, Y) as NONE/NEW */
1623 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1624 				    AMT_FILTER_BOTH,
1625 				    AMT_ACT_STATUS_NONE_NEW,
1626 				    v6);
1627 		/* Update FWD/OLD as FWD/NEW */
1628 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1629 				    AMT_FILTER_FWD,
1630 				    AMT_ACT_STATUS_FWD_NEW,
1631 				    v6);
1632 		/* Update IS_IN (A) as FWD/NEW */
1633 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1634 				    AMT_FILTER_NONE_NEW,
1635 				    AMT_ACT_STATUS_FWD_NEW,
1636 				    v6);
1637 		/* Update EXCLUDE (, Y-A) as D_FWD_NEW */
1638 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB,
1639 				    AMT_FILTER_D_FWD,
1640 				    AMT_ACT_STATUS_D_FWD_NEW,
1641 				    v6);
1642 	}
1643 }
1644 
1645 static void amt_mcast_is_ex_handler(struct amt_dev *amt,
1646 				    struct amt_tunnel_list *tunnel,
1647 				    struct amt_group_node *gnode,
1648 				    void *grec, void *zero_grec, bool v6)
1649 {
1650 	if (gnode->filter_mode == MCAST_INCLUDE) {
1651 /* Router State   Report Rec'd  New Router State         Actions
1652  * ------------   ------------  ----------------         -------
1653  * INCLUDE (A)    IS_EX (B)     EXCLUDE (A*B,B-A)        (B-A)=0
1654  *                                                       Delete (A-B)
1655  *                                                       Group Timer=GMI
1656  */
1657 		/* EXCLUDE(A*B, ) */
1658 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1659 				    AMT_FILTER_FWD,
1660 				    AMT_ACT_STATUS_FWD_NEW,
1661 				    v6);
1662 		/* EXCLUDE(, B-A) */
1663 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1664 				    AMT_FILTER_FWD,
1665 				    AMT_ACT_STATUS_D_FWD_NEW,
1666 				    v6);
1667 		/* (B-A)=0 */
1668 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1669 				    AMT_FILTER_D_FWD_NEW,
1670 				    AMT_ACT_GMI_ZERO,
1671 				    v6);
1672 		/* Group Timer=GMI */
1673 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1674 				      msecs_to_jiffies(amt_gmi(amt))))
1675 			dev_hold(amt->dev);
1676 		gnode->filter_mode = MCAST_EXCLUDE;
1677 		/* Delete (A-B) will be worked by amt_cleanup_srcs(). */
1678 	} else {
1679 /* Router State   Report Rec'd  New Router State	Actions
1680  * ------------   ------------  ----------------	-------
1681  * EXCLUDE (X,Y)  IS_EX (A)     EXCLUDE (A-Y,Y*A)	(A-X-Y)=GMI
1682  *							Delete (X-A)
1683  *							Delete (Y-A)
1684  *							Group Timer=GMI
1685  */
1686 		/* EXCLUDE (A-Y, ) */
1687 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1688 				    AMT_FILTER_D_FWD,
1689 				    AMT_ACT_STATUS_FWD_NEW,
1690 				    v6);
1691 		/* EXCLUDE (, Y*A ) */
1692 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1693 				    AMT_FILTER_D_FWD,
1694 				    AMT_ACT_STATUS_D_FWD_NEW,
1695 				    v6);
1696 		/* (A-X-Y)=GMI */
1697 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1698 				    AMT_FILTER_BOTH_NEW,
1699 				    AMT_ACT_GMI,
1700 				    v6);
1701 		/* Group Timer=GMI */
1702 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1703 				      msecs_to_jiffies(amt_gmi(amt))))
1704 			dev_hold(amt->dev);
1705 		/* Delete (X-A), (Y-A) will be worked by amt_cleanup_srcs(). */
1706 	}
1707 }
1708 
1709 static void amt_mcast_to_in_handler(struct amt_dev *amt,
1710 				    struct amt_tunnel_list *tunnel,
1711 				    struct amt_group_node *gnode,
1712 				    void *grec, void *zero_grec, bool v6)
1713 {
1714 	if (gnode->filter_mode == MCAST_INCLUDE) {
1715 /* Router State   Report Rec'd New Router State        Actions
1716  * ------------   ------------ ----------------        -------
1717  * INCLUDE (A)    TO_IN (B)    INCLUDE (A+B)           (B)=GMI
1718  *						       Send Q(G,A-B)
1719  */
1720 		/* Update TO_IN (B) sources as FWD/NEW */
1721 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1722 				    AMT_FILTER_NONE_NEW,
1723 				    AMT_ACT_STATUS_FWD_NEW,
1724 				    v6);
1725 		/* Update INCLUDE (A) sources as NEW */
1726 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1727 				    AMT_FILTER_FWD,
1728 				    AMT_ACT_STATUS_FWD_NEW,
1729 				    v6);
1730 		/* (B)=GMI */
1731 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1732 				    AMT_FILTER_FWD_NEW,
1733 				    AMT_ACT_GMI,
1734 				    v6);
1735 	} else {
1736 /* Router State   Report Rec'd New Router State        Actions
1737  * ------------   ------------ ----------------        -------
1738  * EXCLUDE (X,Y)  TO_IN (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1739  *						       Send Q(G,X-A)
1740  *						       Send Q(G)
1741  */
1742 		/* Update TO_IN (A) sources as FWD/NEW */
1743 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1744 				    AMT_FILTER_NONE_NEW,
1745 				    AMT_ACT_STATUS_FWD_NEW,
1746 				    v6);
1747 		/* Update EXCLUDE(X,) sources as FWD/NEW */
1748 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1749 				    AMT_FILTER_FWD,
1750 				    AMT_ACT_STATUS_FWD_NEW,
1751 				    v6);
1752 		/* EXCLUDE (, Y-A)
1753 		 * (A) are already switched to FWD_NEW.
1754 		 * So, D_FWD/OLD -> D_FWD/NEW is okay.
1755 		 */
1756 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1757 				    AMT_FILTER_D_FWD,
1758 				    AMT_ACT_STATUS_D_FWD_NEW,
1759 				    v6);
1760 		/* (A)=GMI
1761 		 * Only FWD_NEW will have (A) sources.
1762 		 */
1763 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1764 				    AMT_FILTER_FWD_NEW,
1765 				    AMT_ACT_GMI,
1766 				    v6);
1767 	}
1768 }
1769 
1770 static void amt_mcast_to_ex_handler(struct amt_dev *amt,
1771 				    struct amt_tunnel_list *tunnel,
1772 				    struct amt_group_node *gnode,
1773 				    void *grec, void *zero_grec, bool v6)
1774 {
1775 	if (gnode->filter_mode == MCAST_INCLUDE) {
1776 /* Router State   Report Rec'd New Router State        Actions
1777  * ------------   ------------ ----------------        -------
1778  * INCLUDE (A)    TO_EX (B)    EXCLUDE (A*B,B-A)       (B-A)=0
1779  *						       Delete (A-B)
1780  *						       Send Q(G,A*B)
1781  *						       Group Timer=GMI
1782  */
1783 		/* EXCLUDE (A*B, ) */
1784 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1785 				    AMT_FILTER_FWD,
1786 				    AMT_ACT_STATUS_FWD_NEW,
1787 				    v6);
1788 		/* EXCLUDE (, B-A) */
1789 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1790 				    AMT_FILTER_FWD,
1791 				    AMT_ACT_STATUS_D_FWD_NEW,
1792 				    v6);
1793 		/* (B-A)=0 */
1794 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1795 				    AMT_FILTER_D_FWD_NEW,
1796 				    AMT_ACT_GMI_ZERO,
1797 				    v6);
1798 		/* Group Timer=GMI */
1799 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1800 				      msecs_to_jiffies(amt_gmi(amt))))
1801 			dev_hold(amt->dev);
1802 		gnode->filter_mode = MCAST_EXCLUDE;
1803 		/* Delete (A-B) will be worked by amt_cleanup_srcs(). */
1804 	} else {
1805 /* Router State   Report Rec'd New Router State        Actions
1806  * ------------   ------------ ----------------        -------
1807  * EXCLUDE (X,Y)  TO_EX (A)    EXCLUDE (A-Y,Y*A)       (A-X-Y)=Group Timer
1808  *						       Delete (X-A)
1809  *						       Delete (Y-A)
1810  *						       Send Q(G,A-Y)
1811  *						       Group Timer=GMI
1812  */
1813 		/* Update (A-X-Y) as NONE/OLD */
1814 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1815 				    AMT_FILTER_BOTH,
1816 				    AMT_ACT_GT,
1817 				    v6);
1818 		/* EXCLUDE (A-Y, ) */
1819 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1820 				    AMT_FILTER_D_FWD,
1821 				    AMT_ACT_STATUS_FWD_NEW,
1822 				    v6);
1823 		/* EXCLUDE (, Y*A) */
1824 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1825 				    AMT_FILTER_D_FWD,
1826 				    AMT_ACT_STATUS_D_FWD_NEW,
1827 				    v6);
1828 		/* Group Timer=GMI */
1829 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1830 				      msecs_to_jiffies(amt_gmi(amt))))
1831 			dev_hold(amt->dev);
1832 		/* Delete (X-A), (Y-A) will be worked by amt_cleanup_srcs(). */
1833 	}
1834 }
1835 
1836 static void amt_mcast_allow_handler(struct amt_dev *amt,
1837 				    struct amt_tunnel_list *tunnel,
1838 				    struct amt_group_node *gnode,
1839 				    void *grec, void *zero_grec, bool v6)
1840 {
1841 	if (gnode->filter_mode == MCAST_INCLUDE) {
1842 /* Router State   Report Rec'd New Router State        Actions
1843  * ------------   ------------ ----------------        -------
1844  * INCLUDE (A)    ALLOW (B)    INCLUDE (A+B)	       (B)=GMI
1845  */
1846 		/* INCLUDE (A+B) */
1847 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1848 				    AMT_FILTER_FWD,
1849 				    AMT_ACT_STATUS_FWD_NEW,
1850 				    v6);
1851 		/* (B)=GMI */
1852 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1853 				    AMT_FILTER_FWD_NEW,
1854 				    AMT_ACT_GMI,
1855 				    v6);
1856 	} else {
1857 /* Router State   Report Rec'd New Router State        Actions
1858  * ------------   ------------ ----------------        -------
1859  * EXCLUDE (X,Y)  ALLOW (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1860  */
1861 		/* EXCLUDE (X+A, ) */
1862 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1863 				    AMT_FILTER_FWD,
1864 				    AMT_ACT_STATUS_FWD_NEW,
1865 				    v6);
1866 		/* EXCLUDE (, Y-A) */
1867 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB,
1868 				    AMT_FILTER_D_FWD,
1869 				    AMT_ACT_STATUS_D_FWD_NEW,
1870 				    v6);
1871 		/* (A)=GMI
1872 		 * All (A) source are now FWD/NEW status.
1873 		 */
1874 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1875 				    AMT_FILTER_FWD_NEW,
1876 				    AMT_ACT_GMI,
1877 				    v6);
1878 	}
1879 }
1880 
1881 static void amt_mcast_block_handler(struct amt_dev *amt,
1882 				    struct amt_tunnel_list *tunnel,
1883 				    struct amt_group_node *gnode,
1884 				    void *grec, void *zero_grec, bool v6)
1885 {
1886 	if (gnode->filter_mode == MCAST_INCLUDE) {
1887 /* Router State   Report Rec'd New Router State        Actions
1888  * ------------   ------------ ----------------        -------
1889  * INCLUDE (A)    BLOCK (B)    INCLUDE (A)             Send Q(G,A*B)
1890  */
1891 		/* INCLUDE (A) */
1892 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1893 				    AMT_FILTER_FWD,
1894 				    AMT_ACT_STATUS_FWD_NEW,
1895 				    v6);
1896 	} else {
1897 /* Router State   Report Rec'd New Router State        Actions
1898  * ------------   ------------ ----------------        -------
1899  * EXCLUDE (X,Y)  BLOCK (A)    EXCLUDE (X+(A-Y),Y)     (A-X-Y)=Group Timer
1900  *						       Send Q(G,A-Y)
1901  */
1902 		/* (A-X-Y)=Group Timer */
1903 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1904 				    AMT_FILTER_BOTH,
1905 				    AMT_ACT_GT,
1906 				    v6);
1907 		/* EXCLUDE (X, ) */
1908 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1909 				    AMT_FILTER_FWD,
1910 				    AMT_ACT_STATUS_FWD_NEW,
1911 				    v6);
1912 		/* EXCLUDE (X+(A-Y) */
1913 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1914 				    AMT_FILTER_D_FWD,
1915 				    AMT_ACT_STATUS_FWD_NEW,
1916 				    v6);
1917 		/* EXCLUDE (, Y) */
1918 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1919 				    AMT_FILTER_D_FWD,
1920 				    AMT_ACT_STATUS_D_FWD_NEW,
1921 				    v6);
1922 	}
1923 }
1924 
1925 /* RFC 3376
1926  * 7.3.2. In the Presence of Older Version Group Members
1927  *
1928  * When Group Compatibility Mode is IGMPv2, a router internally
1929  * translates the following IGMPv2 messages for that group to their
1930  * IGMPv3 equivalents:
1931  *
1932  * IGMPv2 Message                IGMPv3 Equivalent
1933  * --------------                -----------------
1934  * Report                        IS_EX( {} )
1935  * Leave                         TO_IN( {} )
1936  */
1937 static void amt_igmpv2_report_handler(struct amt_dev *amt, struct sk_buff *skb,
1938 				      struct amt_tunnel_list *tunnel)
1939 {
1940 	struct igmphdr *ih = igmp_hdr(skb);
1941 	struct iphdr *iph = ip_hdr(skb);
1942 	struct amt_group_node *gnode;
1943 	union amt_addr group, host;
1944 
1945 	memset(&group, 0, sizeof(union amt_addr));
1946 	group.ip4 = ih->group;
1947 	memset(&host, 0, sizeof(union amt_addr));
1948 	host.ip4 = iph->saddr;
1949 
1950 	gnode = amt_lookup_group(tunnel, &group, &host, false);
1951 	if (!gnode) {
1952 		gnode = amt_add_group(amt, tunnel, &group, &host, false);
1953 		if (!IS_ERR(gnode)) {
1954 			gnode->filter_mode = MCAST_EXCLUDE;
1955 			if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1956 					      msecs_to_jiffies(amt_gmi(amt))))
1957 				dev_hold(amt->dev);
1958 		}
1959 	}
1960 }
1961 
1962 /* RFC 3376
1963  * 7.3.2. In the Presence of Older Version Group Members
1964  *
1965  * When Group Compatibility Mode is IGMPv2, a router internally
1966  * translates the following IGMPv2 messages for that group to their
1967  * IGMPv3 equivalents:
1968  *
1969  * IGMPv2 Message                IGMPv3 Equivalent
1970  * --------------                -----------------
1971  * Report                        IS_EX( {} )
1972  * Leave                         TO_IN( {} )
1973  */
1974 static void amt_igmpv2_leave_handler(struct amt_dev *amt, struct sk_buff *skb,
1975 				     struct amt_tunnel_list *tunnel)
1976 {
1977 	struct igmphdr *ih = igmp_hdr(skb);
1978 	struct iphdr *iph = ip_hdr(skb);
1979 	struct amt_group_node *gnode;
1980 	union amt_addr group, host;
1981 
1982 	memset(&group, 0, sizeof(union amt_addr));
1983 	group.ip4 = ih->group;
1984 	memset(&host, 0, sizeof(union amt_addr));
1985 	host.ip4 = iph->saddr;
1986 
1987 	gnode = amt_lookup_group(tunnel, &group, &host, false);
1988 	if (gnode)
1989 		amt_del_group(amt, gnode);
1990 }
1991 
1992 static void amt_igmpv3_report_handler(struct amt_dev *amt, struct sk_buff *skb,
1993 				      struct amt_tunnel_list *tunnel)
1994 {
1995 	struct igmpv3_report *ihrv3 = igmpv3_report_hdr(skb);
1996 	int len = skb_transport_offset(skb) + sizeof(*ihrv3);
1997 	void *zero_grec = (void *)&igmpv3_zero_grec;
1998 	struct iphdr *iph = ip_hdr(skb);
1999 	struct amt_group_node *gnode;
2000 	union amt_addr group, host;
2001 	struct igmpv3_grec *grec;
2002 	u16 nsrcs;
2003 	int i;
2004 
2005 	for (i = 0; i < ntohs(ihrv3->ngrec); i++) {
2006 		len += sizeof(*grec);
2007 		if (!ip_mc_may_pull(skb, len))
2008 			break;
2009 
2010 		grec = (void *)(skb->data + len - sizeof(*grec));
2011 		nsrcs = ntohs(grec->grec_nsrcs);
2012 
2013 		len += nsrcs * sizeof(__be32);
2014 		if (!ip_mc_may_pull(skb, len))
2015 			break;
2016 
2017 		memset(&group, 0, sizeof(union amt_addr));
2018 		group.ip4 = grec->grec_mca;
2019 		memset(&host, 0, sizeof(union amt_addr));
2020 		host.ip4 = iph->saddr;
2021 		gnode = amt_lookup_group(tunnel, &group, &host, false);
2022 		if (!gnode) {
2023 			gnode = amt_add_group(amt, tunnel, &group, &host,
2024 					      false);
2025 			if (IS_ERR(gnode))
2026 				continue;
2027 		}
2028 
2029 		amt_add_srcs(amt, tunnel, gnode, grec, false);
2030 		switch (grec->grec_type) {
2031 		case IGMPV3_MODE_IS_INCLUDE:
2032 			amt_mcast_is_in_handler(amt, tunnel, gnode, grec,
2033 						zero_grec, false);
2034 			break;
2035 		case IGMPV3_MODE_IS_EXCLUDE:
2036 			amt_mcast_is_ex_handler(amt, tunnel, gnode, grec,
2037 						zero_grec, false);
2038 			break;
2039 		case IGMPV3_CHANGE_TO_INCLUDE:
2040 			amt_mcast_to_in_handler(amt, tunnel, gnode, grec,
2041 						zero_grec, false);
2042 			break;
2043 		case IGMPV3_CHANGE_TO_EXCLUDE:
2044 			amt_mcast_to_ex_handler(amt, tunnel, gnode, grec,
2045 						zero_grec, false);
2046 			break;
2047 		case IGMPV3_ALLOW_NEW_SOURCES:
2048 			amt_mcast_allow_handler(amt, tunnel, gnode, grec,
2049 						zero_grec, false);
2050 			break;
2051 		case IGMPV3_BLOCK_OLD_SOURCES:
2052 			amt_mcast_block_handler(amt, tunnel, gnode, grec,
2053 						zero_grec, false);
2054 			break;
2055 		default:
2056 			break;
2057 		}
2058 		amt_cleanup_srcs(amt, tunnel, gnode);
2059 	}
2060 }
2061 
2062 /* caller held tunnel->lock */
2063 static void amt_igmp_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2064 				    struct amt_tunnel_list *tunnel)
2065 {
2066 	struct igmphdr *ih = igmp_hdr(skb);
2067 
2068 	switch (ih->type) {
2069 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
2070 		amt_igmpv3_report_handler(amt, skb, tunnel);
2071 		break;
2072 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
2073 		amt_igmpv2_report_handler(amt, skb, tunnel);
2074 		break;
2075 	case IGMP_HOST_LEAVE_MESSAGE:
2076 		amt_igmpv2_leave_handler(amt, skb, tunnel);
2077 		break;
2078 	default:
2079 		break;
2080 	}
2081 }
2082 
2083 #if IS_ENABLED(CONFIG_IPV6)
2084 /* RFC 3810
2085  * 8.3.2. In the Presence of MLDv1 Multicast Address Listeners
2086  *
2087  * When Multicast Address Compatibility Mode is MLDv2, a router acts
2088  * using the MLDv2 protocol for that multicast address.  When Multicast
2089  * Address Compatibility Mode is MLDv1, a router internally translates
2090  * the following MLDv1 messages for that multicast address to their
2091  * MLDv2 equivalents:
2092  *
2093  * MLDv1 Message                 MLDv2 Equivalent
2094  * --------------                -----------------
2095  * Report                        IS_EX( {} )
2096  * Done                          TO_IN( {} )
2097  */
2098 static void amt_mldv1_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2099 				     struct amt_tunnel_list *tunnel)
2100 {
2101 	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2102 	struct ipv6hdr *ip6h = ipv6_hdr(skb);
2103 	struct amt_group_node *gnode;
2104 	union amt_addr group, host;
2105 
2106 	memcpy(&group.ip6, &mld->mld_mca, sizeof(struct in6_addr));
2107 	memcpy(&host.ip6, &ip6h->saddr, sizeof(struct in6_addr));
2108 
2109 	gnode = amt_lookup_group(tunnel, &group, &host, true);
2110 	if (!gnode) {
2111 		gnode = amt_add_group(amt, tunnel, &group, &host, true);
2112 		if (!IS_ERR(gnode)) {
2113 			gnode->filter_mode = MCAST_EXCLUDE;
2114 			if (!mod_delayed_work(amt_wq, &gnode->group_timer,
2115 					      msecs_to_jiffies(amt_gmi(amt))))
2116 				dev_hold(amt->dev);
2117 		}
2118 	}
2119 }
2120 
2121 /* RFC 3810
2122  * 8.3.2. In the Presence of MLDv1 Multicast Address Listeners
2123  *
2124  * When Multicast Address Compatibility Mode is MLDv2, a router acts
2125  * using the MLDv2 protocol for that multicast address.  When Multicast
2126  * Address Compatibility Mode is MLDv1, a router internally translates
2127  * the following MLDv1 messages for that multicast address to their
2128  * MLDv2 equivalents:
2129  *
2130  * MLDv1 Message                 MLDv2 Equivalent
2131  * --------------                -----------------
2132  * Report                        IS_EX( {} )
2133  * Done                          TO_IN( {} )
2134  */
2135 static void amt_mldv1_leave_handler(struct amt_dev *amt, struct sk_buff *skb,
2136 				    struct amt_tunnel_list *tunnel)
2137 {
2138 	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2139 	struct iphdr *iph = ip_hdr(skb);
2140 	struct amt_group_node *gnode;
2141 	union amt_addr group, host;
2142 
2143 	memcpy(&group.ip6, &mld->mld_mca, sizeof(struct in6_addr));
2144 	memset(&host, 0, sizeof(union amt_addr));
2145 	host.ip4 = iph->saddr;
2146 
2147 	gnode = amt_lookup_group(tunnel, &group, &host, true);
2148 	if (gnode) {
2149 		amt_del_group(amt, gnode);
2150 		return;
2151 	}
2152 }
2153 
2154 static void amt_mldv2_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2155 				     struct amt_tunnel_list *tunnel)
2156 {
2157 	struct mld2_report *mld2r = (struct mld2_report *)icmp6_hdr(skb);
2158 	int len = skb_transport_offset(skb) + sizeof(*mld2r);
2159 	void *zero_grec = (void *)&mldv2_zero_grec;
2160 	struct ipv6hdr *ip6h = ipv6_hdr(skb);
2161 	struct amt_group_node *gnode;
2162 	union amt_addr group, host;
2163 	struct mld2_grec *grec;
2164 	u16 nsrcs;
2165 	int i;
2166 
2167 	for (i = 0; i < ntohs(mld2r->mld2r_ngrec); i++) {
2168 		len += sizeof(*grec);
2169 		if (!ipv6_mc_may_pull(skb, len))
2170 			break;
2171 
2172 		grec = (void *)(skb->data + len - sizeof(*grec));
2173 		nsrcs = ntohs(grec->grec_nsrcs);
2174 
2175 		len += nsrcs * sizeof(struct in6_addr);
2176 		if (!ipv6_mc_may_pull(skb, len))
2177 			break;
2178 
2179 		memset(&group, 0, sizeof(union amt_addr));
2180 		group.ip6 = grec->grec_mca;
2181 		memset(&host, 0, sizeof(union amt_addr));
2182 		host.ip6 = ip6h->saddr;
2183 		gnode = amt_lookup_group(tunnel, &group, &host, true);
2184 		if (!gnode) {
2185 			gnode = amt_add_group(amt, tunnel, &group, &host,
2186 					      ETH_P_IPV6);
2187 			if (IS_ERR(gnode))
2188 				continue;
2189 		}
2190 
2191 		amt_add_srcs(amt, tunnel, gnode, grec, true);
2192 		switch (grec->grec_type) {
2193 		case MLD2_MODE_IS_INCLUDE:
2194 			amt_mcast_is_in_handler(amt, tunnel, gnode, grec,
2195 						zero_grec, true);
2196 			break;
2197 		case MLD2_MODE_IS_EXCLUDE:
2198 			amt_mcast_is_ex_handler(amt, tunnel, gnode, grec,
2199 						zero_grec, true);
2200 			break;
2201 		case MLD2_CHANGE_TO_INCLUDE:
2202 			amt_mcast_to_in_handler(amt, tunnel, gnode, grec,
2203 						zero_grec, true);
2204 			break;
2205 		case MLD2_CHANGE_TO_EXCLUDE:
2206 			amt_mcast_to_ex_handler(amt, tunnel, gnode, grec,
2207 						zero_grec, true);
2208 			break;
2209 		case MLD2_ALLOW_NEW_SOURCES:
2210 			amt_mcast_allow_handler(amt, tunnel, gnode, grec,
2211 						zero_grec, true);
2212 			break;
2213 		case MLD2_BLOCK_OLD_SOURCES:
2214 			amt_mcast_block_handler(amt, tunnel, gnode, grec,
2215 						zero_grec, true);
2216 			break;
2217 		default:
2218 			break;
2219 		}
2220 		amt_cleanup_srcs(amt, tunnel, gnode);
2221 	}
2222 }
2223 
2224 /* caller held tunnel->lock */
2225 static void amt_mld_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2226 				   struct amt_tunnel_list *tunnel)
2227 {
2228 	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2229 
2230 	switch (mld->mld_type) {
2231 	case ICMPV6_MGM_REPORT:
2232 		amt_mldv1_report_handler(amt, skb, tunnel);
2233 		break;
2234 	case ICMPV6_MLD2_REPORT:
2235 		amt_mldv2_report_handler(amt, skb, tunnel);
2236 		break;
2237 	case ICMPV6_MGM_REDUCTION:
2238 		amt_mldv1_leave_handler(amt, skb, tunnel);
2239 		break;
2240 	default:
2241 		break;
2242 	}
2243 }
2244 #endif
2245 
2246 static bool amt_advertisement_handler(struct amt_dev *amt, struct sk_buff *skb)
2247 {
2248 	struct amt_header_advertisement *amta;
2249 	int hdr_size;
2250 
2251 	hdr_size = sizeof(*amta) + sizeof(struct udphdr);
2252 	if (!pskb_may_pull(skb, hdr_size))
2253 		return true;
2254 
2255 	amta = (struct amt_header_advertisement *)(udp_hdr(skb) + 1);
2256 	if (!amta->ip4)
2257 		return true;
2258 
2259 	if (amta->reserved || amta->version)
2260 		return true;
2261 
2262 	if (ipv4_is_loopback(amta->ip4) || ipv4_is_multicast(amta->ip4) ||
2263 	    ipv4_is_zeronet(amta->ip4))
2264 		return true;
2265 
2266 	if (amt->status != AMT_STATUS_SENT_DISCOVERY ||
2267 	    amt->nonce != amta->nonce)
2268 		return true;
2269 
2270 	amt->remote_ip = amta->ip4;
2271 	netdev_dbg(amt->dev, "advertised remote ip = %pI4\n", &amt->remote_ip);
2272 	mod_delayed_work(amt_wq, &amt->req_wq, 0);
2273 
2274 	amt_update_gw_status(amt, AMT_STATUS_RECEIVED_ADVERTISEMENT, true);
2275 	return false;
2276 }
2277 
2278 static bool amt_multicast_data_handler(struct amt_dev *amt, struct sk_buff *skb)
2279 {
2280 	struct amt_header_mcast_data *amtmd;
2281 	int hdr_size, len, err;
2282 	struct ethhdr *eth;
2283 	struct iphdr *iph;
2284 
2285 	if (READ_ONCE(amt->status) != AMT_STATUS_SENT_UPDATE)
2286 		return true;
2287 
2288 	hdr_size = sizeof(*amtmd) + sizeof(struct udphdr);
2289 	if (!pskb_may_pull(skb, hdr_size))
2290 		return true;
2291 
2292 	amtmd = (struct amt_header_mcast_data *)(udp_hdr(skb) + 1);
2293 	if (amtmd->reserved || amtmd->version)
2294 		return true;
2295 
2296 	if (iptunnel_pull_header(skb, hdr_size, htons(ETH_P_IP), false))
2297 		return true;
2298 
2299 	skb_reset_network_header(skb);
2300 	skb_push(skb, sizeof(*eth));
2301 	skb_reset_mac_header(skb);
2302 	skb_pull(skb, sizeof(*eth));
2303 	eth = eth_hdr(skb);
2304 
2305 	if (!pskb_may_pull(skb, sizeof(*iph)))
2306 		return true;
2307 	iph = ip_hdr(skb);
2308 
2309 	if (iph->version == 4) {
2310 		if (!ipv4_is_multicast(iph->daddr))
2311 			return true;
2312 		skb->protocol = htons(ETH_P_IP);
2313 		eth->h_proto = htons(ETH_P_IP);
2314 		ip_eth_mc_map(iph->daddr, eth->h_dest);
2315 #if IS_ENABLED(CONFIG_IPV6)
2316 	} else if (iph->version == 6) {
2317 		struct ipv6hdr *ip6h;
2318 
2319 		if (!pskb_may_pull(skb, sizeof(*ip6h)))
2320 			return true;
2321 
2322 		ip6h = ipv6_hdr(skb);
2323 		if (!ipv6_addr_is_multicast(&ip6h->daddr))
2324 			return true;
2325 		skb->protocol = htons(ETH_P_IPV6);
2326 		eth->h_proto = htons(ETH_P_IPV6);
2327 		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2328 #endif
2329 	} else {
2330 		return true;
2331 	}
2332 
2333 	skb->pkt_type = PACKET_MULTICAST;
2334 	skb->ip_summed = CHECKSUM_NONE;
2335 	len = skb->len;
2336 	err = gro_cells_receive(&amt->gro_cells, skb);
2337 	if (likely(err == NET_RX_SUCCESS))
2338 		dev_sw_netstats_rx_add(amt->dev, len);
2339 	else
2340 		amt->dev->stats.rx_dropped++;
2341 
2342 	return false;
2343 }
2344 
2345 static bool amt_membership_query_handler(struct amt_dev *amt,
2346 					 struct sk_buff *skb)
2347 {
2348 	struct amt_header_membership_query *amtmq;
2349 	struct igmpv3_query *ihv3;
2350 	struct ethhdr *eth, *oeth;
2351 	struct iphdr *iph;
2352 	int hdr_size, len;
2353 
2354 	hdr_size = sizeof(*amtmq) + sizeof(struct udphdr);
2355 	if (!pskb_may_pull(skb, hdr_size))
2356 		return true;
2357 
2358 	amtmq = (struct amt_header_membership_query *)(udp_hdr(skb) + 1);
2359 	if (amtmq->reserved || amtmq->version)
2360 		return true;
2361 
2362 	if (amtmq->nonce != amt->nonce)
2363 		return true;
2364 
2365 	hdr_size -= sizeof(*eth);
2366 	if (iptunnel_pull_header(skb, hdr_size, htons(ETH_P_TEB), false))
2367 		return true;
2368 
2369 	oeth = eth_hdr(skb);
2370 	skb_reset_mac_header(skb);
2371 	skb_pull(skb, sizeof(*eth));
2372 	skb_reset_network_header(skb);
2373 	eth = eth_hdr(skb);
2374 	if (!pskb_may_pull(skb, sizeof(*iph)))
2375 		return true;
2376 
2377 	iph = ip_hdr(skb);
2378 	if (iph->version == 4) {
2379 		if (READ_ONCE(amt->ready4))
2380 			return true;
2381 
2382 		if (!pskb_may_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS +
2383 				   sizeof(*ihv3)))
2384 			return true;
2385 
2386 		if (!ipv4_is_multicast(iph->daddr))
2387 			return true;
2388 
2389 		ihv3 = skb_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
2390 		skb_reset_transport_header(skb);
2391 		skb_push(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
2392 		WRITE_ONCE(amt->ready4, true);
2393 		amt->mac = amtmq->response_mac;
2394 		amt->req_cnt = 0;
2395 		amt->qi = ihv3->qqic;
2396 		skb->protocol = htons(ETH_P_IP);
2397 		eth->h_proto = htons(ETH_P_IP);
2398 		ip_eth_mc_map(iph->daddr, eth->h_dest);
2399 #if IS_ENABLED(CONFIG_IPV6)
2400 	} else if (iph->version == 6) {
2401 		struct mld2_query *mld2q;
2402 		struct ipv6hdr *ip6h;
2403 
2404 		if (READ_ONCE(amt->ready6))
2405 			return true;
2406 
2407 		if (!pskb_may_pull(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS +
2408 				   sizeof(*mld2q)))
2409 			return true;
2410 
2411 		ip6h = ipv6_hdr(skb);
2412 		if (!ipv6_addr_is_multicast(&ip6h->daddr))
2413 			return true;
2414 
2415 		mld2q = skb_pull(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS);
2416 		skb_reset_transport_header(skb);
2417 		skb_push(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS);
2418 		WRITE_ONCE(amt->ready6, true);
2419 		amt->mac = amtmq->response_mac;
2420 		amt->req_cnt = 0;
2421 		amt->qi = mld2q->mld2q_qqic;
2422 		skb->protocol = htons(ETH_P_IPV6);
2423 		eth->h_proto = htons(ETH_P_IPV6);
2424 		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2425 #endif
2426 	} else {
2427 		return true;
2428 	}
2429 
2430 	ether_addr_copy(eth->h_source, oeth->h_source);
2431 	skb->pkt_type = PACKET_MULTICAST;
2432 	skb->ip_summed = CHECKSUM_NONE;
2433 	len = skb->len;
2434 	local_bh_disable();
2435 	if (__netif_rx(skb) == NET_RX_SUCCESS) {
2436 		amt_update_gw_status(amt, AMT_STATUS_RECEIVED_QUERY, true);
2437 		dev_sw_netstats_rx_add(amt->dev, len);
2438 	} else {
2439 		amt->dev->stats.rx_dropped++;
2440 	}
2441 	local_bh_enable();
2442 
2443 	return false;
2444 }
2445 
2446 static bool amt_update_handler(struct amt_dev *amt, struct sk_buff *skb)
2447 {
2448 	struct amt_header_membership_update *amtmu;
2449 	struct amt_tunnel_list *tunnel;
2450 	struct ethhdr *eth;
2451 	struct iphdr *iph;
2452 	int len, hdr_size;
2453 
2454 	iph = ip_hdr(skb);
2455 
2456 	hdr_size = sizeof(*amtmu) + sizeof(struct udphdr);
2457 	if (!pskb_may_pull(skb, hdr_size))
2458 		return true;
2459 
2460 	amtmu = (struct amt_header_membership_update *)(udp_hdr(skb) + 1);
2461 	if (amtmu->reserved || amtmu->version)
2462 		return true;
2463 
2464 	if (iptunnel_pull_header(skb, hdr_size, skb->protocol, false))
2465 		return true;
2466 
2467 	skb_reset_network_header(skb);
2468 
2469 	list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list) {
2470 		if (tunnel->ip4 == iph->saddr) {
2471 			if ((amtmu->nonce == tunnel->nonce &&
2472 			     amtmu->response_mac == tunnel->mac)) {
2473 				mod_delayed_work(amt_wq, &tunnel->gc_wq,
2474 						 msecs_to_jiffies(amt_gmi(amt))
2475 								  * 3);
2476 				goto report;
2477 			} else {
2478 				netdev_dbg(amt->dev, "Invalid MAC\n");
2479 				return true;
2480 			}
2481 		}
2482 	}
2483 
2484 	return true;
2485 
2486 report:
2487 	if (!pskb_may_pull(skb, sizeof(*iph)))
2488 		return true;
2489 
2490 	iph = ip_hdr(skb);
2491 	if (iph->version == 4) {
2492 		if (ip_mc_check_igmp(skb)) {
2493 			netdev_dbg(amt->dev, "Invalid IGMP\n");
2494 			return true;
2495 		}
2496 
2497 		spin_lock_bh(&tunnel->lock);
2498 		amt_igmp_report_handler(amt, skb, tunnel);
2499 		spin_unlock_bh(&tunnel->lock);
2500 
2501 		skb_push(skb, sizeof(struct ethhdr));
2502 		skb_reset_mac_header(skb);
2503 		eth = eth_hdr(skb);
2504 		skb->protocol = htons(ETH_P_IP);
2505 		eth->h_proto = htons(ETH_P_IP);
2506 		ip_eth_mc_map(iph->daddr, eth->h_dest);
2507 #if IS_ENABLED(CONFIG_IPV6)
2508 	} else if (iph->version == 6) {
2509 		struct ipv6hdr *ip6h = ipv6_hdr(skb);
2510 
2511 		if (ipv6_mc_check_mld(skb)) {
2512 			netdev_dbg(amt->dev, "Invalid MLD\n");
2513 			return true;
2514 		}
2515 
2516 		spin_lock_bh(&tunnel->lock);
2517 		amt_mld_report_handler(amt, skb, tunnel);
2518 		spin_unlock_bh(&tunnel->lock);
2519 
2520 		skb_push(skb, sizeof(struct ethhdr));
2521 		skb_reset_mac_header(skb);
2522 		eth = eth_hdr(skb);
2523 		skb->protocol = htons(ETH_P_IPV6);
2524 		eth->h_proto = htons(ETH_P_IPV6);
2525 		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2526 #endif
2527 	} else {
2528 		netdev_dbg(amt->dev, "Unsupported Protocol\n");
2529 		return true;
2530 	}
2531 
2532 	skb_pull(skb, sizeof(struct ethhdr));
2533 	skb->pkt_type = PACKET_MULTICAST;
2534 	skb->ip_summed = CHECKSUM_NONE;
2535 	len = skb->len;
2536 	if (__netif_rx(skb) == NET_RX_SUCCESS) {
2537 		amt_update_relay_status(tunnel, AMT_STATUS_RECEIVED_UPDATE,
2538 					true);
2539 		dev_sw_netstats_rx_add(amt->dev, len);
2540 	} else {
2541 		amt->dev->stats.rx_dropped++;
2542 	}
2543 
2544 	return false;
2545 }
2546 
2547 static void amt_send_advertisement(struct amt_dev *amt, __be32 nonce,
2548 				   __be32 daddr, __be16 dport)
2549 {
2550 	struct amt_header_advertisement *amta;
2551 	int hlen, tlen, offset;
2552 	struct socket *sock;
2553 	struct udphdr *udph;
2554 	struct sk_buff *skb;
2555 	struct iphdr *iph;
2556 	struct rtable *rt;
2557 	struct flowi4 fl4;
2558 	u32 len;
2559 	int err;
2560 
2561 	rcu_read_lock();
2562 	sock = rcu_dereference(amt->sock);
2563 	if (!sock)
2564 		goto out;
2565 
2566 	if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
2567 		goto out;
2568 
2569 	rt = ip_route_output_ports(amt->net, &fl4, sock->sk,
2570 				   daddr, amt->local_ip,
2571 				   dport, amt->relay_port,
2572 				   IPPROTO_UDP, 0,
2573 				   amt->stream_dev->ifindex);
2574 	if (IS_ERR(rt)) {
2575 		amt->dev->stats.tx_errors++;
2576 		goto out;
2577 	}
2578 
2579 	hlen = LL_RESERVED_SPACE(amt->dev);
2580 	tlen = amt->dev->needed_tailroom;
2581 	len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amta);
2582 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
2583 	if (!skb) {
2584 		ip_rt_put(rt);
2585 		amt->dev->stats.tx_errors++;
2586 		goto out;
2587 	}
2588 
2589 	skb->priority = TC_PRIO_CONTROL;
2590 	skb_dst_set(skb, &rt->dst);
2591 
2592 	len = sizeof(*iph) + sizeof(*udph) + sizeof(*amta);
2593 	skb_reset_network_header(skb);
2594 	skb_put(skb, len);
2595 	amta = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
2596 	amta->version	= 0;
2597 	amta->type	= AMT_MSG_ADVERTISEMENT;
2598 	amta->reserved	= 0;
2599 	amta->nonce	= nonce;
2600 	amta->ip4	= amt->local_ip;
2601 	skb_push(skb, sizeof(*udph));
2602 	skb_reset_transport_header(skb);
2603 	udph		= udp_hdr(skb);
2604 	udph->source	= amt->relay_port;
2605 	udph->dest	= dport;
2606 	udph->len	= htons(sizeof(*amta) + sizeof(*udph));
2607 	udph->check	= 0;
2608 	offset = skb_transport_offset(skb);
2609 	skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
2610 	udph->check = csum_tcpudp_magic(amt->local_ip, daddr,
2611 					sizeof(*udph) + sizeof(*amta),
2612 					IPPROTO_UDP, skb->csum);
2613 
2614 	skb_push(skb, sizeof(*iph));
2615 	iph		= ip_hdr(skb);
2616 	iph->version	= 4;
2617 	iph->ihl	= (sizeof(struct iphdr)) >> 2;
2618 	iph->tos	= AMT_TOS;
2619 	iph->frag_off	= 0;
2620 	iph->ttl	= ip4_dst_hoplimit(&rt->dst);
2621 	iph->daddr	= daddr;
2622 	iph->saddr	= amt->local_ip;
2623 	iph->protocol	= IPPROTO_UDP;
2624 	iph->tot_len	= htons(len);
2625 
2626 	skb->ip_summed = CHECKSUM_NONE;
2627 	ip_select_ident(amt->net, skb, NULL);
2628 	ip_send_check(iph);
2629 	err = ip_local_out(amt->net, sock->sk, skb);
2630 	if (unlikely(net_xmit_eval(err)))
2631 		amt->dev->stats.tx_errors++;
2632 
2633 out:
2634 	rcu_read_unlock();
2635 }
2636 
2637 static bool amt_discovery_handler(struct amt_dev *amt, struct sk_buff *skb)
2638 {
2639 	struct amt_header_discovery *amtd;
2640 	struct udphdr *udph;
2641 	struct iphdr *iph;
2642 
2643 	if (!pskb_may_pull(skb, sizeof(*udph) + sizeof(*amtd)))
2644 		return true;
2645 
2646 	iph = ip_hdr(skb);
2647 	udph = udp_hdr(skb);
2648 	amtd = (struct amt_header_discovery *)(udp_hdr(skb) + 1);
2649 
2650 	if (amtd->reserved || amtd->version)
2651 		return true;
2652 
2653 	amt_send_advertisement(amt, amtd->nonce, iph->saddr, udph->source);
2654 
2655 	return false;
2656 }
2657 
2658 static bool amt_request_handler(struct amt_dev *amt, struct sk_buff *skb)
2659 {
2660 	struct amt_header_request *amtrh;
2661 	struct amt_tunnel_list *tunnel;
2662 	unsigned long long key;
2663 	struct udphdr *udph;
2664 	struct iphdr *iph;
2665 	u64 mac;
2666 	int i;
2667 
2668 	if (!pskb_may_pull(skb, sizeof(*udph) + sizeof(*amtrh)))
2669 		return true;
2670 
2671 	iph = ip_hdr(skb);
2672 	udph = udp_hdr(skb);
2673 	amtrh = (struct amt_header_request *)(udp_hdr(skb) + 1);
2674 
2675 	if (amtrh->reserved1 || amtrh->reserved2 || amtrh->version)
2676 		return true;
2677 
2678 	list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list)
2679 		if (tunnel->ip4 == iph->saddr)
2680 			goto send;
2681 
2682 	spin_lock_bh(&amt->lock);
2683 	if (amt->nr_tunnels >= amt->max_tunnels) {
2684 		spin_unlock_bh(&amt->lock);
2685 		icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
2686 		return true;
2687 	}
2688 
2689 	tunnel = kzalloc(sizeof(*tunnel) +
2690 			 (sizeof(struct hlist_head) * amt->hash_buckets),
2691 			 GFP_ATOMIC);
2692 	if (!tunnel) {
2693 		spin_unlock_bh(&amt->lock);
2694 		return true;
2695 	}
2696 
2697 	tunnel->source_port = udph->source;
2698 	tunnel->ip4 = iph->saddr;
2699 
2700 	memcpy(&key, &tunnel->key, sizeof(unsigned long long));
2701 	tunnel->amt = amt;
2702 	spin_lock_init(&tunnel->lock);
2703 	for (i = 0; i < amt->hash_buckets; i++)
2704 		INIT_HLIST_HEAD(&tunnel->groups[i]);
2705 
2706 	INIT_DELAYED_WORK(&tunnel->gc_wq, amt_tunnel_expire);
2707 
2708 	list_add_tail_rcu(&tunnel->list, &amt->tunnel_list);
2709 	tunnel->key = amt->key;
2710 	__amt_update_relay_status(tunnel, AMT_STATUS_RECEIVED_REQUEST, true);
2711 	amt->nr_tunnels++;
2712 	mod_delayed_work(amt_wq, &tunnel->gc_wq,
2713 			 msecs_to_jiffies(amt_gmi(amt)));
2714 	spin_unlock_bh(&amt->lock);
2715 
2716 send:
2717 	tunnel->nonce = amtrh->nonce;
2718 	mac = siphash_3u32((__force u32)tunnel->ip4,
2719 			   (__force u32)tunnel->source_port,
2720 			   (__force u32)tunnel->nonce,
2721 			   &tunnel->key);
2722 	tunnel->mac = mac >> 16;
2723 
2724 	if (!netif_running(amt->dev) || !netif_running(amt->stream_dev))
2725 		return true;
2726 
2727 	if (!amtrh->p)
2728 		amt_send_igmp_gq(amt, tunnel);
2729 	else
2730 		amt_send_mld_gq(amt, tunnel);
2731 
2732 	return false;
2733 }
2734 
2735 static void amt_gw_rcv(struct amt_dev *amt, struct sk_buff *skb)
2736 {
2737 	int type = amt_parse_type(skb);
2738 	int err = 1;
2739 
2740 	if (type == -1)
2741 		goto drop;
2742 
2743 	if (amt->mode == AMT_MODE_GATEWAY) {
2744 		switch (type) {
2745 		case AMT_MSG_ADVERTISEMENT:
2746 			err = amt_advertisement_handler(amt, skb);
2747 			break;
2748 		case AMT_MSG_MEMBERSHIP_QUERY:
2749 			err = amt_membership_query_handler(amt, skb);
2750 			if (!err)
2751 				return;
2752 			break;
2753 		default:
2754 			netdev_dbg(amt->dev, "Invalid type of Gateway\n");
2755 			break;
2756 		}
2757 	}
2758 drop:
2759 	if (err) {
2760 		amt->dev->stats.rx_dropped++;
2761 		kfree_skb(skb);
2762 	} else {
2763 		consume_skb(skb);
2764 	}
2765 }
2766 
2767 static int amt_rcv(struct sock *sk, struct sk_buff *skb)
2768 {
2769 	struct amt_dev *amt;
2770 	struct iphdr *iph;
2771 	int type;
2772 	bool err;
2773 
2774 	rcu_read_lock_bh();
2775 	amt = rcu_dereference_sk_user_data(sk);
2776 	if (!amt) {
2777 		err = true;
2778 		kfree_skb(skb);
2779 		goto out;
2780 	}
2781 
2782 	skb->dev = amt->dev;
2783 	iph = ip_hdr(skb);
2784 	type = amt_parse_type(skb);
2785 	if (type == -1) {
2786 		err = true;
2787 		goto drop;
2788 	}
2789 
2790 	if (amt->mode == AMT_MODE_GATEWAY) {
2791 		switch (type) {
2792 		case AMT_MSG_ADVERTISEMENT:
2793 			if (iph->saddr != amt->discovery_ip) {
2794 				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2795 				err = true;
2796 				goto drop;
2797 			}
2798 			if (amt_queue_event(amt, AMT_EVENT_RECEIVE, skb)) {
2799 				netdev_dbg(amt->dev, "AMT Event queue full\n");
2800 				err = true;
2801 				goto drop;
2802 			}
2803 			goto out;
2804 		case AMT_MSG_MULTICAST_DATA:
2805 			if (iph->saddr != amt->remote_ip) {
2806 				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2807 				err = true;
2808 				goto drop;
2809 			}
2810 			err = amt_multicast_data_handler(amt, skb);
2811 			if (err)
2812 				goto drop;
2813 			else
2814 				goto out;
2815 		case AMT_MSG_MEMBERSHIP_QUERY:
2816 			if (iph->saddr != amt->remote_ip) {
2817 				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2818 				err = true;
2819 				goto drop;
2820 			}
2821 			if (amt_queue_event(amt, AMT_EVENT_RECEIVE, skb)) {
2822 				netdev_dbg(amt->dev, "AMT Event queue full\n");
2823 				err = true;
2824 				goto drop;
2825 			}
2826 			goto out;
2827 		default:
2828 			err = true;
2829 			netdev_dbg(amt->dev, "Invalid type of Gateway\n");
2830 			break;
2831 		}
2832 	} else {
2833 		switch (type) {
2834 		case AMT_MSG_DISCOVERY:
2835 			err = amt_discovery_handler(amt, skb);
2836 			break;
2837 		case AMT_MSG_REQUEST:
2838 			err = amt_request_handler(amt, skb);
2839 			break;
2840 		case AMT_MSG_MEMBERSHIP_UPDATE:
2841 			err = amt_update_handler(amt, skb);
2842 			if (err)
2843 				goto drop;
2844 			else
2845 				goto out;
2846 		default:
2847 			err = true;
2848 			netdev_dbg(amt->dev, "Invalid type of relay\n");
2849 			break;
2850 		}
2851 	}
2852 drop:
2853 	if (err) {
2854 		amt->dev->stats.rx_dropped++;
2855 		kfree_skb(skb);
2856 	} else {
2857 		consume_skb(skb);
2858 	}
2859 out:
2860 	rcu_read_unlock_bh();
2861 	return 0;
2862 }
2863 
2864 static void amt_event_work(struct work_struct *work)
2865 {
2866 	struct amt_dev *amt = container_of(work, struct amt_dev, event_wq);
2867 	struct sk_buff *skb;
2868 	u8 event;
2869 	int i;
2870 
2871 	for (i = 0; i < AMT_MAX_EVENTS; i++) {
2872 		spin_lock_bh(&amt->lock);
2873 		if (amt->nr_events == 0) {
2874 			spin_unlock_bh(&amt->lock);
2875 			return;
2876 		}
2877 		event = amt->events[amt->event_idx].event;
2878 		skb = amt->events[amt->event_idx].skb;
2879 		amt->events[amt->event_idx].event = AMT_EVENT_NONE;
2880 		amt->events[amt->event_idx].skb = NULL;
2881 		amt->nr_events--;
2882 		amt->event_idx++;
2883 		amt->event_idx %= AMT_MAX_EVENTS;
2884 		spin_unlock_bh(&amt->lock);
2885 
2886 		switch (event) {
2887 		case AMT_EVENT_RECEIVE:
2888 			amt_gw_rcv(amt, skb);
2889 			break;
2890 		case AMT_EVENT_SEND_DISCOVERY:
2891 			amt_event_send_discovery(amt);
2892 			break;
2893 		case AMT_EVENT_SEND_REQUEST:
2894 			amt_event_send_request(amt);
2895 			break;
2896 		default:
2897 			kfree_skb(skb);
2898 			break;
2899 		}
2900 	}
2901 }
2902 
2903 static int amt_err_lookup(struct sock *sk, struct sk_buff *skb)
2904 {
2905 	struct amt_dev *amt;
2906 	int type;
2907 
2908 	rcu_read_lock_bh();
2909 	amt = rcu_dereference_sk_user_data(sk);
2910 	if (!amt)
2911 		goto out;
2912 
2913 	if (amt->mode != AMT_MODE_GATEWAY)
2914 		goto drop;
2915 
2916 	type = amt_parse_type(skb);
2917 	if (type == -1)
2918 		goto drop;
2919 
2920 	netdev_dbg(amt->dev, "Received IGMP Unreachable of %s\n",
2921 		   type_str[type]);
2922 	switch (type) {
2923 	case AMT_MSG_DISCOVERY:
2924 		break;
2925 	case AMT_MSG_REQUEST:
2926 	case AMT_MSG_MEMBERSHIP_UPDATE:
2927 		if (READ_ONCE(amt->status) >= AMT_STATUS_RECEIVED_ADVERTISEMENT)
2928 			mod_delayed_work(amt_wq, &amt->req_wq, 0);
2929 		break;
2930 	default:
2931 		goto drop;
2932 	}
2933 out:
2934 	rcu_read_unlock_bh();
2935 	return 0;
2936 drop:
2937 	rcu_read_unlock_bh();
2938 	amt->dev->stats.rx_dropped++;
2939 	return 0;
2940 }
2941 
2942 static struct socket *amt_create_sock(struct net *net, __be16 port)
2943 {
2944 	struct udp_port_cfg udp_conf;
2945 	struct socket *sock;
2946 	int err;
2947 
2948 	memset(&udp_conf, 0, sizeof(udp_conf));
2949 	udp_conf.family = AF_INET;
2950 	udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
2951 
2952 	udp_conf.local_udp_port = port;
2953 
2954 	err = udp_sock_create(net, &udp_conf, &sock);
2955 	if (err < 0)
2956 		return ERR_PTR(err);
2957 
2958 	return sock;
2959 }
2960 
2961 static int amt_socket_create(struct amt_dev *amt)
2962 {
2963 	struct udp_tunnel_sock_cfg tunnel_cfg;
2964 	struct socket *sock;
2965 
2966 	sock = amt_create_sock(amt->net, amt->relay_port);
2967 	if (IS_ERR(sock))
2968 		return PTR_ERR(sock);
2969 
2970 	/* Mark socket as an encapsulation socket */
2971 	memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
2972 	tunnel_cfg.sk_user_data = amt;
2973 	tunnel_cfg.encap_type = 1;
2974 	tunnel_cfg.encap_rcv = amt_rcv;
2975 	tunnel_cfg.encap_err_lookup = amt_err_lookup;
2976 	tunnel_cfg.encap_destroy = NULL;
2977 	setup_udp_tunnel_sock(amt->net, sock, &tunnel_cfg);
2978 
2979 	rcu_assign_pointer(amt->sock, sock);
2980 	return 0;
2981 }
2982 
2983 static int amt_dev_open(struct net_device *dev)
2984 {
2985 	struct amt_dev *amt = netdev_priv(dev);
2986 	int err;
2987 
2988 	amt->ready4 = false;
2989 	amt->ready6 = false;
2990 	amt->event_idx = 0;
2991 	amt->nr_events = 0;
2992 
2993 	err = amt_socket_create(amt);
2994 	if (err)
2995 		return err;
2996 
2997 	amt->req_cnt = 0;
2998 	amt->remote_ip = 0;
2999 	amt->nonce = 0;
3000 	get_random_bytes(&amt->key, sizeof(siphash_key_t));
3001 
3002 	amt->status = AMT_STATUS_INIT;
3003 	if (amt->mode == AMT_MODE_GATEWAY) {
3004 		mod_delayed_work(amt_wq, &amt->discovery_wq, 0);
3005 		mod_delayed_work(amt_wq, &amt->req_wq, 0);
3006 	} else if (amt->mode == AMT_MODE_RELAY) {
3007 		mod_delayed_work(amt_wq, &amt->secret_wq,
3008 				 msecs_to_jiffies(AMT_SECRET_TIMEOUT));
3009 	}
3010 	return err;
3011 }
3012 
3013 static int amt_dev_stop(struct net_device *dev)
3014 {
3015 	struct amt_dev *amt = netdev_priv(dev);
3016 	struct amt_tunnel_list *tunnel, *tmp;
3017 	struct socket *sock;
3018 	struct sk_buff *skb;
3019 	int i;
3020 
3021 	cancel_delayed_work_sync(&amt->req_wq);
3022 	cancel_delayed_work_sync(&amt->discovery_wq);
3023 	cancel_delayed_work_sync(&amt->secret_wq);
3024 
3025 	/* shutdown */
3026 	sock = rtnl_dereference(amt->sock);
3027 	RCU_INIT_POINTER(amt->sock, NULL);
3028 	synchronize_net();
3029 	if (sock)
3030 		udp_tunnel_sock_release(sock);
3031 
3032 	cancel_work_sync(&amt->event_wq);
3033 	for (i = 0; i < AMT_MAX_EVENTS; i++) {
3034 		skb = amt->events[i].skb;
3035 		kfree_skb(skb);
3036 		amt->events[i].event = AMT_EVENT_NONE;
3037 		amt->events[i].skb = NULL;
3038 	}
3039 
3040 	amt->ready4 = false;
3041 	amt->ready6 = false;
3042 	amt->req_cnt = 0;
3043 	amt->remote_ip = 0;
3044 
3045 	list_for_each_entry_safe(tunnel, tmp, &amt->tunnel_list, list) {
3046 		list_del_rcu(&tunnel->list);
3047 		amt->nr_tunnels--;
3048 		cancel_delayed_work_sync(&tunnel->gc_wq);
3049 		amt_clear_groups(tunnel);
3050 		kfree_rcu(tunnel, rcu);
3051 	}
3052 
3053 	return 0;
3054 }
3055 
3056 static const struct device_type amt_type = {
3057 	.name = "amt",
3058 };
3059 
3060 static int amt_dev_init(struct net_device *dev)
3061 {
3062 	struct amt_dev *amt = netdev_priv(dev);
3063 	int err;
3064 
3065 	amt->dev = dev;
3066 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
3067 	if (!dev->tstats)
3068 		return -ENOMEM;
3069 
3070 	err = gro_cells_init(&amt->gro_cells, dev);
3071 	if (err) {
3072 		free_percpu(dev->tstats);
3073 		return err;
3074 	}
3075 
3076 	return 0;
3077 }
3078 
3079 static void amt_dev_uninit(struct net_device *dev)
3080 {
3081 	struct amt_dev *amt = netdev_priv(dev);
3082 
3083 	gro_cells_destroy(&amt->gro_cells);
3084 	free_percpu(dev->tstats);
3085 }
3086 
3087 static const struct net_device_ops amt_netdev_ops = {
3088 	.ndo_init               = amt_dev_init,
3089 	.ndo_uninit             = amt_dev_uninit,
3090 	.ndo_open		= amt_dev_open,
3091 	.ndo_stop		= amt_dev_stop,
3092 	.ndo_start_xmit         = amt_dev_xmit,
3093 	.ndo_get_stats64        = dev_get_tstats64,
3094 };
3095 
3096 static void amt_link_setup(struct net_device *dev)
3097 {
3098 	dev->netdev_ops         = &amt_netdev_ops;
3099 	dev->needs_free_netdev  = true;
3100 	SET_NETDEV_DEVTYPE(dev, &amt_type);
3101 	dev->min_mtu		= ETH_MIN_MTU;
3102 	dev->max_mtu		= ETH_MAX_MTU;
3103 	dev->type		= ARPHRD_NONE;
3104 	dev->flags		= IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
3105 	dev->hard_header_len	= 0;
3106 	dev->addr_len		= 0;
3107 	dev->priv_flags		|= IFF_NO_QUEUE;
3108 	dev->features		|= NETIF_F_LLTX;
3109 	dev->features		|= NETIF_F_GSO_SOFTWARE;
3110 	dev->features		|= NETIF_F_NETNS_LOCAL;
3111 	dev->hw_features	|= NETIF_F_SG | NETIF_F_HW_CSUM;
3112 	dev->hw_features	|= NETIF_F_FRAGLIST | NETIF_F_RXCSUM;
3113 	dev->hw_features	|= NETIF_F_GSO_SOFTWARE;
3114 	eth_hw_addr_random(dev);
3115 	eth_zero_addr(dev->broadcast);
3116 	ether_setup(dev);
3117 }
3118 
3119 static const struct nla_policy amt_policy[IFLA_AMT_MAX + 1] = {
3120 	[IFLA_AMT_MODE]		= { .type = NLA_U32 },
3121 	[IFLA_AMT_RELAY_PORT]	= { .type = NLA_U16 },
3122 	[IFLA_AMT_GATEWAY_PORT]	= { .type = NLA_U16 },
3123 	[IFLA_AMT_LINK]		= { .type = NLA_U32 },
3124 	[IFLA_AMT_LOCAL_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
3125 	[IFLA_AMT_REMOTE_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
3126 	[IFLA_AMT_DISCOVERY_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
3127 	[IFLA_AMT_MAX_TUNNELS]	= { .type = NLA_U32 },
3128 };
3129 
3130 static int amt_validate(struct nlattr *tb[], struct nlattr *data[],
3131 			struct netlink_ext_ack *extack)
3132 {
3133 	if (!data)
3134 		return -EINVAL;
3135 
3136 	if (!data[IFLA_AMT_LINK]) {
3137 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_LINK],
3138 				    "Link attribute is required");
3139 		return -EINVAL;
3140 	}
3141 
3142 	if (!data[IFLA_AMT_MODE]) {
3143 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_MODE],
3144 				    "Mode attribute is required");
3145 		return -EINVAL;
3146 	}
3147 
3148 	if (nla_get_u32(data[IFLA_AMT_MODE]) > AMT_MODE_MAX) {
3149 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_MODE],
3150 				    "Mode attribute is not valid");
3151 		return -EINVAL;
3152 	}
3153 
3154 	if (!data[IFLA_AMT_LOCAL_IP]) {
3155 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_DISCOVERY_IP],
3156 				    "Local attribute is required");
3157 		return -EINVAL;
3158 	}
3159 
3160 	if (!data[IFLA_AMT_DISCOVERY_IP] &&
3161 	    nla_get_u32(data[IFLA_AMT_MODE]) == AMT_MODE_GATEWAY) {
3162 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_LOCAL_IP],
3163 				    "Discovery attribute is required");
3164 		return -EINVAL;
3165 	}
3166 
3167 	return 0;
3168 }
3169 
3170 static int amt_newlink(struct net *net, struct net_device *dev,
3171 		       struct nlattr *tb[], struct nlattr *data[],
3172 		       struct netlink_ext_ack *extack)
3173 {
3174 	struct amt_dev *amt = netdev_priv(dev);
3175 	int err = -EINVAL;
3176 
3177 	amt->net = net;
3178 	amt->mode = nla_get_u32(data[IFLA_AMT_MODE]);
3179 
3180 	if (data[IFLA_AMT_MAX_TUNNELS] &&
3181 	    nla_get_u32(data[IFLA_AMT_MAX_TUNNELS]))
3182 		amt->max_tunnels = nla_get_u32(data[IFLA_AMT_MAX_TUNNELS]);
3183 	else
3184 		amt->max_tunnels = AMT_MAX_TUNNELS;
3185 
3186 	spin_lock_init(&amt->lock);
3187 	amt->max_groups = AMT_MAX_GROUP;
3188 	amt->max_sources = AMT_MAX_SOURCE;
3189 	amt->hash_buckets = AMT_HSIZE;
3190 	amt->nr_tunnels = 0;
3191 	get_random_bytes(&amt->hash_seed, sizeof(amt->hash_seed));
3192 	amt->stream_dev = dev_get_by_index(net,
3193 					   nla_get_u32(data[IFLA_AMT_LINK]));
3194 	if (!amt->stream_dev) {
3195 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LINK],
3196 				    "Can't find stream device");
3197 		return -ENODEV;
3198 	}
3199 
3200 	if (amt->stream_dev->type != ARPHRD_ETHER) {
3201 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LINK],
3202 				    "Invalid stream device type");
3203 		goto err;
3204 	}
3205 
3206 	amt->local_ip = nla_get_in_addr(data[IFLA_AMT_LOCAL_IP]);
3207 	if (ipv4_is_loopback(amt->local_ip) ||
3208 	    ipv4_is_zeronet(amt->local_ip) ||
3209 	    ipv4_is_multicast(amt->local_ip)) {
3210 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LOCAL_IP],
3211 				    "Invalid Local address");
3212 		goto err;
3213 	}
3214 
3215 	if (data[IFLA_AMT_RELAY_PORT])
3216 		amt->relay_port = nla_get_be16(data[IFLA_AMT_RELAY_PORT]);
3217 	else
3218 		amt->relay_port = htons(IANA_AMT_UDP_PORT);
3219 
3220 	if (data[IFLA_AMT_GATEWAY_PORT])
3221 		amt->gw_port = nla_get_be16(data[IFLA_AMT_GATEWAY_PORT]);
3222 	else
3223 		amt->gw_port = htons(IANA_AMT_UDP_PORT);
3224 
3225 	if (!amt->relay_port) {
3226 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3227 				    "relay port must not be 0");
3228 		goto err;
3229 	}
3230 	if (amt->mode == AMT_MODE_RELAY) {
3231 		amt->qrv = READ_ONCE(amt->net->ipv4.sysctl_igmp_qrv);
3232 		amt->qri = 10;
3233 		dev->needed_headroom = amt->stream_dev->needed_headroom +
3234 				       AMT_RELAY_HLEN;
3235 		dev->mtu = amt->stream_dev->mtu - AMT_RELAY_HLEN;
3236 		dev->max_mtu = dev->mtu;
3237 		dev->min_mtu = ETH_MIN_MTU + AMT_RELAY_HLEN;
3238 	} else {
3239 		if (!data[IFLA_AMT_DISCOVERY_IP]) {
3240 			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3241 					    "discovery must be set in gateway mode");
3242 			goto err;
3243 		}
3244 		if (!amt->gw_port) {
3245 			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3246 					    "gateway port must not be 0");
3247 			goto err;
3248 		}
3249 		amt->remote_ip = 0;
3250 		amt->discovery_ip = nla_get_in_addr(data[IFLA_AMT_DISCOVERY_IP]);
3251 		if (ipv4_is_loopback(amt->discovery_ip) ||
3252 		    ipv4_is_zeronet(amt->discovery_ip) ||
3253 		    ipv4_is_multicast(amt->discovery_ip)) {
3254 			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3255 					    "discovery must be unicast");
3256 			goto err;
3257 		}
3258 
3259 		dev->needed_headroom = amt->stream_dev->needed_headroom +
3260 				       AMT_GW_HLEN;
3261 		dev->mtu = amt->stream_dev->mtu - AMT_GW_HLEN;
3262 		dev->max_mtu = dev->mtu;
3263 		dev->min_mtu = ETH_MIN_MTU + AMT_GW_HLEN;
3264 	}
3265 	amt->qi = AMT_INIT_QUERY_INTERVAL;
3266 
3267 	err = register_netdevice(dev);
3268 	if (err < 0) {
3269 		netdev_dbg(dev, "failed to register new netdev %d\n", err);
3270 		goto err;
3271 	}
3272 
3273 	err = netdev_upper_dev_link(amt->stream_dev, dev, extack);
3274 	if (err < 0) {
3275 		unregister_netdevice(dev);
3276 		goto err;
3277 	}
3278 
3279 	INIT_DELAYED_WORK(&amt->discovery_wq, amt_discovery_work);
3280 	INIT_DELAYED_WORK(&amt->req_wq, amt_req_work);
3281 	INIT_DELAYED_WORK(&amt->secret_wq, amt_secret_work);
3282 	INIT_WORK(&amt->event_wq, amt_event_work);
3283 	INIT_LIST_HEAD(&amt->tunnel_list);
3284 	return 0;
3285 err:
3286 	dev_put(amt->stream_dev);
3287 	return err;
3288 }
3289 
3290 static void amt_dellink(struct net_device *dev, struct list_head *head)
3291 {
3292 	struct amt_dev *amt = netdev_priv(dev);
3293 
3294 	unregister_netdevice_queue(dev, head);
3295 	netdev_upper_dev_unlink(amt->stream_dev, dev);
3296 	dev_put(amt->stream_dev);
3297 }
3298 
3299 static size_t amt_get_size(const struct net_device *dev)
3300 {
3301 	return nla_total_size(sizeof(__u32)) + /* IFLA_AMT_MODE */
3302 	       nla_total_size(sizeof(__u16)) + /* IFLA_AMT_RELAY_PORT */
3303 	       nla_total_size(sizeof(__u16)) + /* IFLA_AMT_GATEWAY_PORT */
3304 	       nla_total_size(sizeof(__u32)) + /* IFLA_AMT_LINK */
3305 	       nla_total_size(sizeof(__u32)) + /* IFLA_MAX_TUNNELS */
3306 	       nla_total_size(sizeof(struct iphdr)) + /* IFLA_AMT_DISCOVERY_IP */
3307 	       nla_total_size(sizeof(struct iphdr)) + /* IFLA_AMT_REMOTE_IP */
3308 	       nla_total_size(sizeof(struct iphdr)); /* IFLA_AMT_LOCAL_IP */
3309 }
3310 
3311 static int amt_fill_info(struct sk_buff *skb, const struct net_device *dev)
3312 {
3313 	struct amt_dev *amt = netdev_priv(dev);
3314 
3315 	if (nla_put_u32(skb, IFLA_AMT_MODE, amt->mode))
3316 		goto nla_put_failure;
3317 	if (nla_put_be16(skb, IFLA_AMT_RELAY_PORT, amt->relay_port))
3318 		goto nla_put_failure;
3319 	if (nla_put_be16(skb, IFLA_AMT_GATEWAY_PORT, amt->gw_port))
3320 		goto nla_put_failure;
3321 	if (nla_put_u32(skb, IFLA_AMT_LINK, amt->stream_dev->ifindex))
3322 		goto nla_put_failure;
3323 	if (nla_put_in_addr(skb, IFLA_AMT_LOCAL_IP, amt->local_ip))
3324 		goto nla_put_failure;
3325 	if (nla_put_in_addr(skb, IFLA_AMT_DISCOVERY_IP, amt->discovery_ip))
3326 		goto nla_put_failure;
3327 	if (amt->remote_ip)
3328 		if (nla_put_in_addr(skb, IFLA_AMT_REMOTE_IP, amt->remote_ip))
3329 			goto nla_put_failure;
3330 	if (nla_put_u32(skb, IFLA_AMT_MAX_TUNNELS, amt->max_tunnels))
3331 		goto nla_put_failure;
3332 
3333 	return 0;
3334 
3335 nla_put_failure:
3336 	return -EMSGSIZE;
3337 }
3338 
3339 static struct rtnl_link_ops amt_link_ops __read_mostly = {
3340 	.kind		= "amt",
3341 	.maxtype	= IFLA_AMT_MAX,
3342 	.policy		= amt_policy,
3343 	.priv_size	= sizeof(struct amt_dev),
3344 	.setup		= amt_link_setup,
3345 	.validate	= amt_validate,
3346 	.newlink	= amt_newlink,
3347 	.dellink	= amt_dellink,
3348 	.get_size       = amt_get_size,
3349 	.fill_info      = amt_fill_info,
3350 };
3351 
3352 static struct net_device *amt_lookup_upper_dev(struct net_device *dev)
3353 {
3354 	struct net_device *upper_dev;
3355 	struct amt_dev *amt;
3356 
3357 	for_each_netdev(dev_net(dev), upper_dev) {
3358 		if (netif_is_amt(upper_dev)) {
3359 			amt = netdev_priv(upper_dev);
3360 			if (amt->stream_dev == dev)
3361 				return upper_dev;
3362 		}
3363 	}
3364 
3365 	return NULL;
3366 }
3367 
3368 static int amt_device_event(struct notifier_block *unused,
3369 			    unsigned long event, void *ptr)
3370 {
3371 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3372 	struct net_device *upper_dev;
3373 	struct amt_dev *amt;
3374 	LIST_HEAD(list);
3375 	int new_mtu;
3376 
3377 	upper_dev = amt_lookup_upper_dev(dev);
3378 	if (!upper_dev)
3379 		return NOTIFY_DONE;
3380 	amt = netdev_priv(upper_dev);
3381 
3382 	switch (event) {
3383 	case NETDEV_UNREGISTER:
3384 		amt_dellink(amt->dev, &list);
3385 		unregister_netdevice_many(&list);
3386 		break;
3387 	case NETDEV_CHANGEMTU:
3388 		if (amt->mode == AMT_MODE_RELAY)
3389 			new_mtu = dev->mtu - AMT_RELAY_HLEN;
3390 		else
3391 			new_mtu = dev->mtu - AMT_GW_HLEN;
3392 
3393 		dev_set_mtu(amt->dev, new_mtu);
3394 		break;
3395 	}
3396 
3397 	return NOTIFY_DONE;
3398 }
3399 
3400 static struct notifier_block amt_notifier_block __read_mostly = {
3401 	.notifier_call = amt_device_event,
3402 };
3403 
3404 static int __init amt_init(void)
3405 {
3406 	int err;
3407 
3408 	err = register_netdevice_notifier(&amt_notifier_block);
3409 	if (err < 0)
3410 		goto err;
3411 
3412 	err = rtnl_link_register(&amt_link_ops);
3413 	if (err < 0)
3414 		goto unregister_notifier;
3415 
3416 	amt_wq = alloc_workqueue("amt", WQ_UNBOUND, 0);
3417 	if (!amt_wq) {
3418 		err = -ENOMEM;
3419 		goto rtnl_unregister;
3420 	}
3421 
3422 	spin_lock_init(&source_gc_lock);
3423 	spin_lock_bh(&source_gc_lock);
3424 	INIT_DELAYED_WORK(&source_gc_wq, amt_source_gc_work);
3425 	mod_delayed_work(amt_wq, &source_gc_wq,
3426 			 msecs_to_jiffies(AMT_GC_INTERVAL));
3427 	spin_unlock_bh(&source_gc_lock);
3428 
3429 	return 0;
3430 
3431 rtnl_unregister:
3432 	rtnl_link_unregister(&amt_link_ops);
3433 unregister_notifier:
3434 	unregister_netdevice_notifier(&amt_notifier_block);
3435 err:
3436 	pr_err("error loading AMT module loaded\n");
3437 	return err;
3438 }
3439 late_initcall(amt_init);
3440 
3441 static void __exit amt_fini(void)
3442 {
3443 	rtnl_link_unregister(&amt_link_ops);
3444 	unregister_netdevice_notifier(&amt_notifier_block);
3445 	cancel_delayed_work_sync(&source_gc_wq);
3446 	__amt_source_gc_work();
3447 	destroy_workqueue(amt_wq);
3448 }
3449 module_exit(amt_fini);
3450 
3451 MODULE_LICENSE("GPL");
3452 MODULE_DESCRIPTION("Driver for Automatic Multicast Tunneling (AMT)");
3453 MODULE_AUTHOR("Taehee Yoo <ap420073@gmail.com>");
3454 MODULE_ALIAS_RTNL_LINK("amt");
3455