xref: /linux/drivers/net/amt.c (revision b470fde8f77b56ff273c5527484b99499b894e16)
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/flow.h>
15 #include <net/pkt_sched.h>
16 #include <net/net_namespace.h>
17 #include <net/ip.h>
18 #include <net/udp.h>
19 #include <net/udp_tunnel.h>
20 #include <net/icmp.h>
21 #include <net/mld.h>
22 #include <net/amt.h>
23 #include <uapi/linux/amt.h>
24 #include <linux/security.h>
25 #include <net/gro_cells.h>
26 #include <net/ipv6.h>
27 #include <net/if_inet6.h>
28 #include <net/ndisc.h>
29 #include <net/addrconf.h>
30 #include <net/ip6_route.h>
31 #include <net/inet_common.h>
32 #include <net/inet_dscp.h>
33 #include <net/ip6_checksum.h>
34 
35 static struct workqueue_struct *amt_wq;
36 
37 static HLIST_HEAD(source_gc_list);
38 /* Lock for source_gc_list */
39 static spinlock_t source_gc_lock;
40 static struct delayed_work source_gc_wq;
41 static char *status_str[] = {
42 	"AMT_STATUS_INIT",
43 	"AMT_STATUS_SENT_DISCOVERY",
44 	"AMT_STATUS_RECEIVED_DISCOVERY",
45 	"AMT_STATUS_SENT_ADVERTISEMENT",
46 	"AMT_STATUS_RECEIVED_ADVERTISEMENT",
47 	"AMT_STATUS_SENT_REQUEST",
48 	"AMT_STATUS_RECEIVED_REQUEST",
49 	"AMT_STATUS_SENT_QUERY",
50 	"AMT_STATUS_RECEIVED_QUERY",
51 	"AMT_STATUS_SENT_UPDATE",
52 	"AMT_STATUS_RECEIVED_UPDATE",
53 };
54 
55 static char *type_str[] = {
56 	"", /* Type 0 is not defined */
57 	"AMT_MSG_DISCOVERY",
58 	"AMT_MSG_ADVERTISEMENT",
59 	"AMT_MSG_REQUEST",
60 	"AMT_MSG_MEMBERSHIP_QUERY",
61 	"AMT_MSG_MEMBERSHIP_UPDATE",
62 	"AMT_MSG_MULTICAST_DATA",
63 	"AMT_MSG_TEARDOWN",
64 };
65 
66 static char *action_str[] = {
67 	"AMT_ACT_GMI",
68 	"AMT_ACT_GMI_ZERO",
69 	"AMT_ACT_GT",
70 	"AMT_ACT_STATUS_FWD_NEW",
71 	"AMT_ACT_STATUS_D_FWD_NEW",
72 	"AMT_ACT_STATUS_NONE_NEW",
73 };
74 
75 static struct igmpv3_grec igmpv3_zero_grec;
76 
77 #if IS_ENABLED(CONFIG_IPV6)
78 #define MLD2_ALL_NODE_INIT { { { 0xff, 0x02, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x01 } } }
79 static struct in6_addr mld2_all_node = MLD2_ALL_NODE_INIT;
80 static struct mld2_grec mldv2_zero_grec;
81 #endif
82 
83 static struct amt_skb_cb *amt_skb_cb(struct sk_buff *skb)
84 {
85 	BUILD_BUG_ON(sizeof(struct amt_skb_cb) + sizeof(struct tc_skb_cb) >
86 		     sizeof_field(struct sk_buff, cb));
87 
88 	return (struct amt_skb_cb *)((void *)skb->cb +
89 		sizeof(struct tc_skb_cb));
90 }
91 
92 static void __amt_source_gc_work(void)
93 {
94 	struct amt_source_node *snode;
95 	struct hlist_head gc_list;
96 	struct hlist_node *t;
97 
98 	spin_lock_bh(&source_gc_lock);
99 	hlist_move_list(&source_gc_list, &gc_list);
100 	spin_unlock_bh(&source_gc_lock);
101 
102 	hlist_for_each_entry_safe(snode, t, &gc_list, node) {
103 		hlist_del_rcu(&snode->node);
104 		kfree_rcu(snode, rcu);
105 	}
106 }
107 
108 static void amt_source_gc_work(struct work_struct *work)
109 {
110 	__amt_source_gc_work();
111 
112 	spin_lock_bh(&source_gc_lock);
113 	mod_delayed_work(amt_wq, &source_gc_wq,
114 			 msecs_to_jiffies(AMT_GC_INTERVAL));
115 	spin_unlock_bh(&source_gc_lock);
116 }
117 
118 static bool amt_addr_equal(union amt_addr *a, union amt_addr *b)
119 {
120 	return !memcmp(a, b, sizeof(union amt_addr));
121 }
122 
123 static u32 amt_source_hash(struct amt_tunnel_list *tunnel, union amt_addr *src)
124 {
125 	u32 hash = jhash(src, sizeof(*src), tunnel->amt->hash_seed);
126 
127 	return reciprocal_scale(hash, tunnel->amt->hash_buckets);
128 }
129 
130 static bool amt_status_filter(struct amt_source_node *snode,
131 			      enum amt_filter filter)
132 {
133 	bool rc = false;
134 
135 	switch (filter) {
136 	case AMT_FILTER_FWD:
137 		if (snode->status == AMT_SOURCE_STATUS_FWD &&
138 		    snode->flags == AMT_SOURCE_OLD)
139 			rc = true;
140 		break;
141 	case AMT_FILTER_D_FWD:
142 		if (snode->status == AMT_SOURCE_STATUS_D_FWD &&
143 		    snode->flags == AMT_SOURCE_OLD)
144 			rc = true;
145 		break;
146 	case AMT_FILTER_FWD_NEW:
147 		if (snode->status == AMT_SOURCE_STATUS_FWD &&
148 		    snode->flags == AMT_SOURCE_NEW)
149 			rc = true;
150 		break;
151 	case AMT_FILTER_D_FWD_NEW:
152 		if (snode->status == AMT_SOURCE_STATUS_D_FWD &&
153 		    snode->flags == AMT_SOURCE_NEW)
154 			rc = true;
155 		break;
156 	case AMT_FILTER_ALL:
157 		rc = true;
158 		break;
159 	case AMT_FILTER_NONE_NEW:
160 		if (snode->status == AMT_SOURCE_STATUS_NONE &&
161 		    snode->flags == AMT_SOURCE_NEW)
162 			rc = true;
163 		break;
164 	case AMT_FILTER_BOTH:
165 		if ((snode->status == AMT_SOURCE_STATUS_D_FWD ||
166 		     snode->status == AMT_SOURCE_STATUS_FWD) &&
167 		    snode->flags == AMT_SOURCE_OLD)
168 			rc = true;
169 		break;
170 	case AMT_FILTER_BOTH_NEW:
171 		if ((snode->status == AMT_SOURCE_STATUS_D_FWD ||
172 		     snode->status == AMT_SOURCE_STATUS_FWD) &&
173 		    snode->flags == AMT_SOURCE_NEW)
174 			rc = true;
175 		break;
176 	default:
177 		WARN_ON_ONCE(1);
178 		break;
179 	}
180 
181 	return rc;
182 }
183 
184 static struct amt_source_node *amt_lookup_src(struct amt_tunnel_list *tunnel,
185 					      struct amt_group_node *gnode,
186 					      enum amt_filter filter,
187 					      union amt_addr *src)
188 {
189 	u32 hash = amt_source_hash(tunnel, src);
190 	struct amt_source_node *snode;
191 
192 	hlist_for_each_entry_rcu(snode, &gnode->sources[hash], node)
193 		if (amt_status_filter(snode, filter) &&
194 		    amt_addr_equal(&snode->source_addr, src))
195 			return snode;
196 
197 	return NULL;
198 }
199 
200 static u32 amt_group_hash(struct amt_tunnel_list *tunnel, union amt_addr *group)
201 {
202 	u32 hash = jhash(group, sizeof(*group), tunnel->amt->hash_seed);
203 
204 	return reciprocal_scale(hash, tunnel->amt->hash_buckets);
205 }
206 
207 static struct amt_group_node *amt_lookup_group(struct amt_tunnel_list *tunnel,
208 					       union amt_addr *group,
209 					       union amt_addr *host,
210 					       bool v6)
211 {
212 	u32 hash = amt_group_hash(tunnel, group);
213 	struct amt_group_node *gnode;
214 
215 	hlist_for_each_entry_rcu(gnode, &tunnel->groups[hash], node) {
216 		if (amt_addr_equal(&gnode->group_addr, group) &&
217 		    amt_addr_equal(&gnode->host_addr, host) &&
218 		    gnode->v6 == v6)
219 			return gnode;
220 	}
221 
222 	return NULL;
223 }
224 
225 static void amt_destroy_source(struct amt_source_node *snode)
226 {
227 	struct amt_group_node *gnode = snode->gnode;
228 	struct amt_tunnel_list *tunnel;
229 
230 	tunnel = gnode->tunnel_list;
231 
232 	if (!gnode->v6) {
233 		netdev_dbg(snode->gnode->amt->dev,
234 			   "Delete source %pI4 from %pI4\n",
235 			   &snode->source_addr.ip4,
236 			   &gnode->group_addr.ip4);
237 #if IS_ENABLED(CONFIG_IPV6)
238 	} else {
239 		netdev_dbg(snode->gnode->amt->dev,
240 			   "Delete source %pI6 from %pI6\n",
241 			   &snode->source_addr.ip6,
242 			   &gnode->group_addr.ip6);
243 #endif
244 	}
245 
246 	cancel_delayed_work(&snode->source_timer);
247 	hlist_del_init_rcu(&snode->node);
248 	tunnel->nr_sources--;
249 	gnode->nr_sources--;
250 	spin_lock_bh(&source_gc_lock);
251 	hlist_add_head_rcu(&snode->node, &source_gc_list);
252 	spin_unlock_bh(&source_gc_lock);
253 }
254 
255 static void amt_del_group(struct amt_dev *amt, struct amt_group_node *gnode)
256 {
257 	struct amt_source_node *snode;
258 	struct hlist_node *t;
259 	int i;
260 
261 	if (cancel_delayed_work(&gnode->group_timer))
262 		dev_put(amt->dev);
263 	hlist_del_rcu(&gnode->node);
264 	gnode->tunnel_list->nr_groups--;
265 
266 	if (!gnode->v6)
267 		netdev_dbg(amt->dev, "Leave group %pI4\n",
268 			   &gnode->group_addr.ip4);
269 #if IS_ENABLED(CONFIG_IPV6)
270 	else
271 		netdev_dbg(amt->dev, "Leave group %pI6\n",
272 			   &gnode->group_addr.ip6);
273 #endif
274 	for (i = 0; i < amt->hash_buckets; i++)
275 		hlist_for_each_entry_safe(snode, t, &gnode->sources[i], node)
276 			amt_destroy_source(snode);
277 
278 	/* tunnel->lock was acquired outside of amt_del_group()
279 	 * But rcu_read_lock() was acquired too so It's safe.
280 	 */
281 	kfree_rcu(gnode, rcu);
282 }
283 
284 /* If a source timer expires with a router filter-mode for the group of
285  * INCLUDE, the router concludes that traffic from this particular
286  * source is no longer desired on the attached network, and deletes the
287  * associated source record.
288  */
289 static void amt_source_work(struct work_struct *work)
290 {
291 	struct amt_source_node *snode = container_of(to_delayed_work(work),
292 						     struct amt_source_node,
293 						     source_timer);
294 	struct amt_group_node *gnode = snode->gnode;
295 	struct amt_dev *amt = gnode->amt;
296 	struct amt_tunnel_list *tunnel;
297 
298 	tunnel = gnode->tunnel_list;
299 	spin_lock_bh(&tunnel->lock);
300 	rcu_read_lock();
301 	if (gnode->filter_mode == MCAST_INCLUDE) {
302 		amt_destroy_source(snode);
303 		if (!gnode->nr_sources)
304 			amt_del_group(amt, gnode);
305 	} else {
306 		/* When a router filter-mode for a group is EXCLUDE,
307 		 * source records are only deleted when the group timer expires
308 		 */
309 		snode->status = AMT_SOURCE_STATUS_D_FWD;
310 	}
311 	rcu_read_unlock();
312 	spin_unlock_bh(&tunnel->lock);
313 }
314 
315 static void amt_act_src(struct amt_tunnel_list *tunnel,
316 			struct amt_group_node *gnode,
317 			struct amt_source_node *snode,
318 			enum amt_act act)
319 {
320 	struct amt_dev *amt = tunnel->amt;
321 
322 	switch (act) {
323 	case AMT_ACT_GMI:
324 		mod_delayed_work(amt_wq, &snode->source_timer,
325 				 msecs_to_jiffies(amt_gmi(amt)));
326 		break;
327 	case AMT_ACT_GMI_ZERO:
328 		cancel_delayed_work(&snode->source_timer);
329 		break;
330 	case AMT_ACT_GT:
331 		mod_delayed_work(amt_wq, &snode->source_timer,
332 				 gnode->group_timer.timer.expires);
333 		break;
334 	case AMT_ACT_STATUS_FWD_NEW:
335 		snode->status = AMT_SOURCE_STATUS_FWD;
336 		snode->flags = AMT_SOURCE_NEW;
337 		break;
338 	case AMT_ACT_STATUS_D_FWD_NEW:
339 		snode->status = AMT_SOURCE_STATUS_D_FWD;
340 		snode->flags = AMT_SOURCE_NEW;
341 		break;
342 	case AMT_ACT_STATUS_NONE_NEW:
343 		cancel_delayed_work(&snode->source_timer);
344 		snode->status = AMT_SOURCE_STATUS_NONE;
345 		snode->flags = AMT_SOURCE_NEW;
346 		break;
347 	default:
348 		WARN_ON_ONCE(1);
349 		return;
350 	}
351 
352 	if (!gnode->v6)
353 		netdev_dbg(amt->dev, "Source %pI4 from %pI4 Acted %s\n",
354 			   &snode->source_addr.ip4,
355 			   &gnode->group_addr.ip4,
356 			   action_str[act]);
357 #if IS_ENABLED(CONFIG_IPV6)
358 	else
359 		netdev_dbg(amt->dev, "Source %pI6 from %pI6 Acted %s\n",
360 			   &snode->source_addr.ip6,
361 			   &gnode->group_addr.ip6,
362 			   action_str[act]);
363 #endif
364 }
365 
366 static struct amt_source_node *amt_alloc_snode(struct amt_group_node *gnode,
367 					       union amt_addr *src)
368 {
369 	struct amt_source_node *snode;
370 
371 	snode = kzalloc_obj(*snode, GFP_ATOMIC);
372 	if (!snode)
373 		return NULL;
374 
375 	memcpy(&snode->source_addr, src, sizeof(union amt_addr));
376 	snode->gnode = gnode;
377 	snode->status = AMT_SOURCE_STATUS_NONE;
378 	snode->flags = AMT_SOURCE_NEW;
379 	INIT_HLIST_NODE(&snode->node);
380 	INIT_DELAYED_WORK(&snode->source_timer, amt_source_work);
381 
382 	return snode;
383 }
384 
385 /* RFC 3810 - 7.2.2.  Definition of Filter Timers
386  *
387  *  Router Mode          Filter Timer         Actions/Comments
388  *  -----------       -----------------       ----------------
389  *
390  *    INCLUDE             Not Used            All listeners in
391  *                                            INCLUDE mode.
392  *
393  *    EXCLUDE             Timer > 0           At least one listener
394  *                                            in EXCLUDE mode.
395  *
396  *    EXCLUDE             Timer == 0          No more listeners in
397  *                                            EXCLUDE mode for the
398  *                                            multicast address.
399  *                                            If the Requested List
400  *                                            is empty, delete
401  *                                            Multicast Address
402  *                                            Record.  If not, switch
403  *                                            to INCLUDE filter mode;
404  *                                            the sources in the
405  *                                            Requested List are
406  *                                            moved to the Include
407  *                                            List, and the Exclude
408  *                                            List is deleted.
409  */
410 static void amt_group_work(struct work_struct *work)
411 {
412 	struct amt_group_node *gnode = container_of(to_delayed_work(work),
413 						    struct amt_group_node,
414 						    group_timer);
415 	struct amt_tunnel_list *tunnel = gnode->tunnel_list;
416 	struct amt_dev *amt = gnode->amt;
417 	struct amt_source_node *snode;
418 	bool delete_group = true;
419 	struct hlist_node *t;
420 	int i, buckets;
421 
422 	buckets = amt->hash_buckets;
423 
424 	spin_lock_bh(&tunnel->lock);
425 	if (gnode->filter_mode == MCAST_INCLUDE) {
426 		/* Not Used */
427 		spin_unlock_bh(&tunnel->lock);
428 		goto out;
429 	}
430 
431 	rcu_read_lock();
432 	for (i = 0; i < buckets; i++) {
433 		hlist_for_each_entry_safe(snode, t,
434 					  &gnode->sources[i], node) {
435 			if (!delayed_work_pending(&snode->source_timer) ||
436 			    snode->status == AMT_SOURCE_STATUS_D_FWD) {
437 				amt_destroy_source(snode);
438 			} else {
439 				delete_group = false;
440 				snode->status = AMT_SOURCE_STATUS_FWD;
441 			}
442 		}
443 	}
444 	if (delete_group)
445 		amt_del_group(amt, gnode);
446 	else
447 		gnode->filter_mode = MCAST_INCLUDE;
448 	rcu_read_unlock();
449 	spin_unlock_bh(&tunnel->lock);
450 out:
451 	dev_put(amt->dev);
452 }
453 
454 /* Non-existent group is created as INCLUDE {empty}:
455  *
456  * RFC 3376 - 5.1. Action on Change of Interface State
457  *
458  * If no interface state existed for that multicast address before
459  * the change (i.e., the change consisted of creating a new
460  * per-interface record), or if no state exists after the change
461  * (i.e., the change consisted of deleting a per-interface record),
462  * then the "non-existent" state is considered to have a filter mode
463  * of INCLUDE and an empty source list.
464  */
465 static struct amt_group_node *amt_add_group(struct amt_dev *amt,
466 					    struct amt_tunnel_list *tunnel,
467 					    union amt_addr *group,
468 					    union amt_addr *host,
469 					    bool v6)
470 {
471 	struct amt_group_node *gnode;
472 	u32 hash;
473 	int i;
474 
475 	if (tunnel->nr_groups >= amt->max_groups)
476 		return ERR_PTR(-ENOSPC);
477 
478 	gnode = kzalloc(sizeof(*gnode) +
479 			(sizeof(struct hlist_head) * amt->hash_buckets),
480 			GFP_ATOMIC);
481 	if (unlikely(!gnode))
482 		return ERR_PTR(-ENOMEM);
483 
484 	gnode->amt = amt;
485 	gnode->group_addr = *group;
486 	gnode->host_addr = *host;
487 	gnode->v6 = v6;
488 	gnode->tunnel_list = tunnel;
489 	gnode->filter_mode = MCAST_INCLUDE;
490 	INIT_HLIST_NODE(&gnode->node);
491 	INIT_DELAYED_WORK(&gnode->group_timer, amt_group_work);
492 	for (i = 0; i < amt->hash_buckets; i++)
493 		INIT_HLIST_HEAD(&gnode->sources[i]);
494 
495 	hash = amt_group_hash(tunnel, group);
496 	hlist_add_head_rcu(&gnode->node, &tunnel->groups[hash]);
497 	tunnel->nr_groups++;
498 
499 	if (!gnode->v6)
500 		netdev_dbg(amt->dev, "Join group %pI4\n",
501 			   &gnode->group_addr.ip4);
502 #if IS_ENABLED(CONFIG_IPV6)
503 	else
504 		netdev_dbg(amt->dev, "Join group %pI6\n",
505 			   &gnode->group_addr.ip6);
506 #endif
507 
508 	return gnode;
509 }
510 
511 static struct sk_buff *amt_build_igmp_gq(struct amt_dev *amt)
512 {
513 	u8 ra[AMT_IPHDR_OPTS] = { IPOPT_RA, 4, 0, 0 };
514 	int hlen = LL_RESERVED_SPACE(amt->dev);
515 	int tlen = amt->dev->needed_tailroom;
516 	struct igmpv3_query *ihv3;
517 	void *csum_start = NULL;
518 	__sum16 *csum = NULL;
519 	struct sk_buff *skb;
520 	struct ethhdr *eth;
521 	struct iphdr *iph;
522 	unsigned int len;
523 	int offset;
524 
525 	len = hlen + tlen + sizeof(*iph) + AMT_IPHDR_OPTS + sizeof(*ihv3);
526 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
527 	if (!skb)
528 		return NULL;
529 
530 	skb_reserve(skb, hlen);
531 	skb_push(skb, sizeof(*eth));
532 	skb->protocol = htons(ETH_P_IP);
533 	skb_reset_mac_header(skb);
534 	skb->priority = TC_PRIO_CONTROL;
535 	skb_put(skb, sizeof(*iph));
536 	skb_put_data(skb, ra, sizeof(ra));
537 	skb_put(skb, sizeof(*ihv3));
538 	skb_pull(skb, sizeof(*eth));
539 	skb_reset_network_header(skb);
540 
541 	iph		= ip_hdr(skb);
542 	iph->version	= 4;
543 	iph->ihl	= (sizeof(struct iphdr) + AMT_IPHDR_OPTS) >> 2;
544 	iph->tos	= AMT_TOS;
545 	iph->tot_len	= htons(sizeof(*iph) + AMT_IPHDR_OPTS + sizeof(*ihv3));
546 	iph->frag_off	= htons(IP_DF);
547 	iph->ttl	= 1;
548 	iph->id		= 0;
549 	iph->protocol	= IPPROTO_IGMP;
550 	iph->daddr	= htonl(INADDR_ALLHOSTS_GROUP);
551 	iph->saddr	= htonl(INADDR_ANY);
552 	ip_send_check(iph);
553 
554 	eth = eth_hdr(skb);
555 	ether_addr_copy(eth->h_source, amt->dev->dev_addr);
556 	ip_eth_mc_map(htonl(INADDR_ALLHOSTS_GROUP), eth->h_dest);
557 	eth->h_proto = htons(ETH_P_IP);
558 
559 	ihv3		= skb_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
560 	skb_reset_transport_header(skb);
561 	ihv3->type	= IGMP_HOST_MEMBERSHIP_QUERY;
562 	ihv3->code	= 1;
563 	ihv3->group	= 0;
564 	ihv3->qqic	= amt->qi;
565 	ihv3->nsrcs	= 0;
566 	ihv3->resv	= 0;
567 	ihv3->suppress	= false;
568 	ihv3->qrv	= READ_ONCE(amt->net->ipv4.sysctl_igmp_qrv);
569 	ihv3->csum	= 0;
570 	csum		= &ihv3->csum;
571 	csum_start	= (void *)ihv3;
572 	*csum		= ip_compute_csum(csum_start, sizeof(*ihv3));
573 	offset		= skb_transport_offset(skb);
574 	skb->csum	= skb_checksum(skb, offset, skb->len - offset, 0);
575 	skb->ip_summed	= CHECKSUM_NONE;
576 
577 	skb_push(skb, sizeof(*eth) + sizeof(*iph) + AMT_IPHDR_OPTS);
578 
579 	return skb;
580 }
581 
582 static void amt_update_gw_status(struct amt_dev *amt, enum amt_status status,
583 				 bool validate)
584 {
585 	if (validate && amt->status >= status)
586 		return;
587 	netdev_dbg(amt->dev, "Update GW status %s -> %s",
588 		   status_str[amt->status], status_str[status]);
589 	WRITE_ONCE(amt->status, status);
590 }
591 
592 static void __amt_update_relay_status(struct amt_tunnel_list *tunnel,
593 				      enum amt_status status,
594 				      bool validate)
595 {
596 	if (validate && tunnel->status >= status)
597 		return;
598 	netdev_dbg(tunnel->amt->dev,
599 		   "Update Tunnel(IP = %pI4, PORT = %u) status %s -> %s",
600 		   &tunnel->ip4, ntohs(tunnel->source_port),
601 		   status_str[tunnel->status], status_str[status]);
602 	tunnel->status = status;
603 }
604 
605 static void amt_update_relay_status(struct amt_tunnel_list *tunnel,
606 				    enum amt_status status, bool validate)
607 {
608 	spin_lock_bh(&tunnel->lock);
609 	__amt_update_relay_status(tunnel, status, validate);
610 	spin_unlock_bh(&tunnel->lock);
611 }
612 
613 static void amt_send_discovery(struct amt_dev *amt)
614 {
615 	struct amt_header_discovery *amtd;
616 	int hlen, tlen, offset;
617 	struct udphdr *udph;
618 	struct sk_buff *skb;
619 	struct iphdr *iph;
620 	struct rtable *rt;
621 	struct flowi4 fl4;
622 	struct sock *sk;
623 	u32 len;
624 	int err;
625 
626 	rcu_read_lock();
627 	sk = rcu_dereference(amt->sk);
628 	if (!sk)
629 		goto out;
630 
631 	if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
632 		goto out;
633 
634 	rt = ip_route_output_ports(amt->net, &fl4, sk,
635 				   amt->discovery_ip, amt->local_ip,
636 				   amt->gw_port, amt->relay_port,
637 				   IPPROTO_UDP, 0,
638 				   amt->stream_dev->ifindex);
639 	if (IS_ERR(rt)) {
640 		amt->dev->stats.tx_errors++;
641 		goto out;
642 	}
643 
644 	hlen = LL_RESERVED_SPACE(amt->dev);
645 	tlen = amt->dev->needed_tailroom;
646 	len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amtd);
647 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
648 	if (!skb) {
649 		ip_rt_put(rt);
650 		amt->dev->stats.tx_errors++;
651 		goto out;
652 	}
653 
654 	skb->priority = TC_PRIO_CONTROL;
655 	skb_dst_set(skb, &rt->dst);
656 
657 	len = sizeof(*iph) + sizeof(*udph) + sizeof(*amtd);
658 	skb_reset_network_header(skb);
659 	skb_put(skb, len);
660 	amtd = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
661 	amtd->version	= 0;
662 	amtd->type	= AMT_MSG_DISCOVERY;
663 	amtd->reserved	= 0;
664 	amtd->nonce	= amt->nonce;
665 	skb_push(skb, sizeof(*udph));
666 	skb_reset_transport_header(skb);
667 	udph		= udp_hdr(skb);
668 	udph->source	= amt->gw_port;
669 	udph->dest	= amt->relay_port;
670 	udph->len	= htons(sizeof(*udph) + sizeof(*amtd));
671 	udph->check	= 0;
672 	offset = skb_transport_offset(skb);
673 	skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
674 	udph->check = csum_tcpudp_magic(amt->local_ip, amt->discovery_ip,
675 					sizeof(*udph) + sizeof(*amtd),
676 					IPPROTO_UDP, skb->csum);
677 
678 	skb_push(skb, sizeof(*iph));
679 	iph		= ip_hdr(skb);
680 	iph->version	= 4;
681 	iph->ihl	= (sizeof(struct iphdr)) >> 2;
682 	iph->tos	= AMT_TOS;
683 	iph->frag_off	= 0;
684 	iph->ttl	= ip4_dst_hoplimit(&rt->dst);
685 	iph->daddr	= amt->discovery_ip;
686 	iph->saddr	= amt->local_ip;
687 	iph->protocol	= IPPROTO_UDP;
688 	iph->tot_len	= htons(len);
689 
690 	skb->ip_summed = CHECKSUM_NONE;
691 	ip_select_ident(amt->net, skb, NULL);
692 	ip_send_check(iph);
693 	err = ip_local_out(amt->net, sk, skb);
694 	if (unlikely(net_xmit_eval(err)))
695 		amt->dev->stats.tx_errors++;
696 
697 	amt_update_gw_status(amt, AMT_STATUS_SENT_DISCOVERY, true);
698 out:
699 	rcu_read_unlock();
700 }
701 
702 static void amt_send_request(struct amt_dev *amt, bool v6)
703 {
704 	struct amt_header_request *amtrh;
705 	int hlen, tlen, offset;
706 	struct udphdr *udph;
707 	struct sk_buff *skb;
708 	struct iphdr *iph;
709 	struct rtable *rt;
710 	struct flowi4 fl4;
711 	__be32 remote_ip;
712 	struct sock *sk;
713 	u32 len;
714 	int err;
715 
716 	rcu_read_lock();
717 	remote_ip = READ_ONCE(amt->remote_ip);
718 	sk = rcu_dereference(amt->sk);
719 	if (!sk)
720 		goto out;
721 
722 	if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
723 		goto out;
724 
725 	rt = ip_route_output_ports(amt->net, &fl4, sk,
726 				   remote_ip, amt->local_ip,
727 				   amt->gw_port, amt->relay_port,
728 				   IPPROTO_UDP, 0,
729 				   amt->stream_dev->ifindex);
730 	if (IS_ERR(rt)) {
731 		amt->dev->stats.tx_errors++;
732 		goto out;
733 	}
734 
735 	hlen = LL_RESERVED_SPACE(amt->dev);
736 	tlen = amt->dev->needed_tailroom;
737 	len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amtrh);
738 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
739 	if (!skb) {
740 		ip_rt_put(rt);
741 		amt->dev->stats.tx_errors++;
742 		goto out;
743 	}
744 
745 	skb->priority = TC_PRIO_CONTROL;
746 	skb_dst_set(skb, &rt->dst);
747 
748 	len = sizeof(*iph) + sizeof(*udph) + sizeof(*amtrh);
749 	skb_reset_network_header(skb);
750 	skb_put(skb, len);
751 	amtrh = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
752 	amtrh->version	 = 0;
753 	amtrh->type	 = AMT_MSG_REQUEST;
754 	amtrh->reserved1 = 0;
755 	amtrh->p	 = v6;
756 	amtrh->reserved2 = 0;
757 	amtrh->nonce	 = amt->nonce;
758 	skb_push(skb, sizeof(*udph));
759 	skb_reset_transport_header(skb);
760 	udph		= udp_hdr(skb);
761 	udph->source	= amt->gw_port;
762 	udph->dest	= amt->relay_port;
763 	udph->len	= htons(sizeof(*amtrh) + sizeof(*udph));
764 	udph->check	= 0;
765 	offset = skb_transport_offset(skb);
766 	skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
767 	udph->check = csum_tcpudp_magic(amt->local_ip, remote_ip,
768 					sizeof(*udph) + sizeof(*amtrh),
769 					IPPROTO_UDP, skb->csum);
770 
771 	skb_push(skb, sizeof(*iph));
772 	iph		= ip_hdr(skb);
773 	iph->version	= 4;
774 	iph->ihl	= (sizeof(struct iphdr)) >> 2;
775 	iph->tos	= AMT_TOS;
776 	iph->frag_off	= 0;
777 	iph->ttl	= ip4_dst_hoplimit(&rt->dst);
778 	iph->daddr	= remote_ip;
779 	iph->saddr	= amt->local_ip;
780 	iph->protocol	= IPPROTO_UDP;
781 	iph->tot_len	= htons(len);
782 
783 	skb->ip_summed = CHECKSUM_NONE;
784 	ip_select_ident(amt->net, skb, NULL);
785 	ip_send_check(iph);
786 	err = ip_local_out(amt->net, sk, skb);
787 	if (unlikely(net_xmit_eval(err)))
788 		amt->dev->stats.tx_errors++;
789 
790 out:
791 	rcu_read_unlock();
792 }
793 
794 static void amt_send_igmp_gq(struct amt_dev *amt,
795 			     struct amt_tunnel_list *tunnel)
796 {
797 	struct sk_buff *skb;
798 
799 	skb = amt_build_igmp_gq(amt);
800 	if (!skb)
801 		return;
802 
803 	amt_skb_cb(skb)->tunnel = tunnel;
804 	dev_queue_xmit(skb);
805 }
806 
807 #if IS_ENABLED(CONFIG_IPV6)
808 static struct sk_buff *amt_build_mld_gq(struct amt_dev *amt)
809 {
810 	u8 ra[AMT_IP6HDR_OPTS] = { IPPROTO_ICMPV6, 0, IPV6_TLV_ROUTERALERT,
811 				   2, 0, 0, IPV6_TLV_PAD1, IPV6_TLV_PAD1 };
812 	int hlen = LL_RESERVED_SPACE(amt->dev);
813 	int tlen = amt->dev->needed_tailroom;
814 	struct mld2_query *mld2q;
815 	void *csum_start = NULL;
816 	struct ipv6hdr *ip6h;
817 	struct sk_buff *skb;
818 	struct ethhdr *eth;
819 	u32 len;
820 
821 	len = hlen + tlen + sizeof(*ip6h) + sizeof(ra) + sizeof(*mld2q);
822 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
823 	if (!skb)
824 		return NULL;
825 
826 	skb_reserve(skb, hlen);
827 	skb_push(skb, sizeof(*eth));
828 	skb_reset_mac_header(skb);
829 	eth = eth_hdr(skb);
830 	skb->priority = TC_PRIO_CONTROL;
831 	skb->protocol = htons(ETH_P_IPV6);
832 	skb_put_zero(skb, sizeof(*ip6h));
833 	skb_put_data(skb, ra, sizeof(ra));
834 	skb_put_zero(skb, sizeof(*mld2q));
835 	skb_pull(skb, sizeof(*eth));
836 	skb_reset_network_header(skb);
837 	ip6h			= ipv6_hdr(skb);
838 	ip6h->payload_len	= htons(sizeof(ra) + sizeof(*mld2q));
839 	ip6h->nexthdr		= NEXTHDR_HOP;
840 	ip6h->hop_limit		= 1;
841 	ip6h->daddr		= mld2_all_node;
842 	ip6_flow_hdr(ip6h, 0, 0);
843 
844 	if (ipv6_dev_get_saddr(amt->net, amt->dev, &ip6h->daddr, 0,
845 			       &ip6h->saddr)) {
846 		amt->dev->stats.tx_errors++;
847 		kfree_skb(skb);
848 		return NULL;
849 	}
850 
851 	eth->h_proto = htons(ETH_P_IPV6);
852 	ether_addr_copy(eth->h_source, amt->dev->dev_addr);
853 	ipv6_eth_mc_map(&mld2_all_node, eth->h_dest);
854 
855 	skb_pull(skb, sizeof(*ip6h) + sizeof(ra));
856 	skb_reset_transport_header(skb);
857 	mld2q			= (struct mld2_query *)icmp6_hdr(skb);
858 	mld2q->mld2q_mrc	= htons(1);
859 	mld2q->mld2q_type	= ICMPV6_MGM_QUERY;
860 	mld2q->mld2q_code	= 0;
861 	mld2q->mld2q_cksum	= 0;
862 	mld2q->mld2q_resv1	= 0;
863 	mld2q->mld2q_resv2	= 0;
864 	mld2q->mld2q_suppress	= 0;
865 	mld2q->mld2q_qrv	= amt->qrv;
866 	mld2q->mld2q_nsrcs	= 0;
867 	mld2q->mld2q_qqic	= amt->qi;
868 	csum_start		= (void *)mld2q;
869 	mld2q->mld2q_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
870 					     sizeof(*mld2q),
871 					     IPPROTO_ICMPV6,
872 					     csum_partial(csum_start,
873 							  sizeof(*mld2q), 0));
874 
875 	skb->ip_summed = CHECKSUM_NONE;
876 	skb_push(skb, sizeof(*eth) + sizeof(*ip6h) + sizeof(ra));
877 	return skb;
878 }
879 
880 static void amt_send_mld_gq(struct amt_dev *amt, struct amt_tunnel_list *tunnel)
881 {
882 	struct sk_buff *skb;
883 
884 	skb = amt_build_mld_gq(amt);
885 	if (!skb)
886 		return;
887 
888 	amt_skb_cb(skb)->tunnel = tunnel;
889 	dev_queue_xmit(skb);
890 }
891 #else
892 static void amt_send_mld_gq(struct amt_dev *amt, struct amt_tunnel_list *tunnel)
893 {
894 }
895 #endif
896 
897 static bool amt_queue_event(struct amt_dev *amt, enum amt_event event,
898 			    struct sk_buff *skb)
899 {
900 	int index;
901 
902 	spin_lock_bh(&amt->lock);
903 	if (amt->nr_events >= AMT_MAX_EVENTS) {
904 		spin_unlock_bh(&amt->lock);
905 		return 1;
906 	}
907 
908 	index = (amt->event_idx + amt->nr_events) % AMT_MAX_EVENTS;
909 	amt->events[index].event = event;
910 	amt->events[index].skb = skb;
911 	amt->nr_events++;
912 	amt->event_idx %= AMT_MAX_EVENTS;
913 	queue_work(amt_wq, &amt->event_wq);
914 	spin_unlock_bh(&amt->lock);
915 
916 	return 0;
917 }
918 
919 static void amt_secret_work(struct work_struct *work)
920 {
921 	struct amt_dev *amt = container_of(to_delayed_work(work),
922 					   struct amt_dev,
923 					   secret_wq);
924 
925 	spin_lock_bh(&amt->lock);
926 	get_random_bytes(&amt->key, sizeof(siphash_key_t));
927 	spin_unlock_bh(&amt->lock);
928 	mod_delayed_work(amt_wq, &amt->secret_wq,
929 			 msecs_to_jiffies(AMT_SECRET_TIMEOUT));
930 }
931 
932 static void amt_event_send_discovery(struct amt_dev *amt)
933 {
934 	if (amt->status > AMT_STATUS_SENT_DISCOVERY)
935 		goto out;
936 	get_random_bytes(&amt->nonce, sizeof(__be32));
937 
938 	amt_send_discovery(amt);
939 out:
940 	mod_delayed_work(amt_wq, &amt->discovery_wq,
941 			 msecs_to_jiffies(AMT_DISCOVERY_TIMEOUT));
942 }
943 
944 static void amt_discovery_work(struct work_struct *work)
945 {
946 	struct amt_dev *amt = container_of(to_delayed_work(work),
947 					   struct amt_dev,
948 					   discovery_wq);
949 
950 	if (amt_queue_event(amt, AMT_EVENT_SEND_DISCOVERY, NULL))
951 		mod_delayed_work(amt_wq, &amt->discovery_wq,
952 				 msecs_to_jiffies(AMT_DISCOVERY_TIMEOUT));
953 }
954 
955 static void amt_event_send_request(struct amt_dev *amt)
956 {
957 	u32 exp;
958 
959 	if (amt->status < AMT_STATUS_RECEIVED_ADVERTISEMENT)
960 		goto out;
961 
962 	if (amt->req_cnt > AMT_MAX_REQ_COUNT) {
963 		netdev_dbg(amt->dev, "Gateway is not ready");
964 		amt->qi = AMT_INIT_REQ_TIMEOUT;
965 		WRITE_ONCE(amt->ready4, false);
966 		WRITE_ONCE(amt->ready6, false);
967 		WRITE_ONCE(amt->remote_ip, 0);
968 		amt_update_gw_status(amt, AMT_STATUS_INIT, false);
969 		amt->req_cnt = 0;
970 		amt->nonce = 0;
971 		goto out;
972 	}
973 
974 	if (!amt->req_cnt) {
975 		WRITE_ONCE(amt->ready4, false);
976 		WRITE_ONCE(amt->ready6, false);
977 		get_random_bytes(&amt->nonce, sizeof(__be32));
978 	}
979 
980 	amt_send_request(amt, false);
981 	amt_send_request(amt, true);
982 	amt_update_gw_status(amt, AMT_STATUS_SENT_REQUEST, true);
983 	amt->req_cnt++;
984 out:
985 	exp = min_t(u32, (1 * (1 << amt->req_cnt)), AMT_MAX_REQ_TIMEOUT);
986 	mod_delayed_work(amt_wq, &amt->req_wq, secs_to_jiffies(exp));
987 }
988 
989 static void amt_req_work(struct work_struct *work)
990 {
991 	struct amt_dev *amt = container_of(to_delayed_work(work),
992 					   struct amt_dev,
993 					   req_wq);
994 
995 	if (amt_queue_event(amt, AMT_EVENT_SEND_REQUEST, NULL))
996 		mod_delayed_work(amt_wq, &amt->req_wq,
997 				 msecs_to_jiffies(100));
998 }
999 
1000 static bool amt_send_membership_update(struct amt_dev *amt,
1001 				       struct sk_buff *skb,
1002 				       bool v6)
1003 {
1004 	__be32 remote_ip = READ_ONCE(amt->remote_ip);
1005 	struct amt_header_membership_update *amtmu;
1006 	struct iphdr *iph;
1007 	struct flowi4 fl4;
1008 	struct rtable *rt;
1009 	struct sock *sk;
1010 	int err;
1011 
1012 	sk = rcu_dereference_bh(amt->sk);
1013 	if (!sk)
1014 		return true;
1015 
1016 	err = skb_cow_head(skb, LL_RESERVED_SPACE(amt->dev) + sizeof(*amtmu) +
1017 			   sizeof(*iph) + sizeof(struct udphdr));
1018 	if (err)
1019 		return true;
1020 
1021 	skb_reset_inner_headers(skb);
1022 	memset(&fl4, 0, sizeof(struct flowi4));
1023 	fl4.flowi4_oif         = amt->stream_dev->ifindex;
1024 	fl4.daddr              = remote_ip;
1025 	fl4.saddr              = amt->local_ip;
1026 	fl4.flowi4_dscp        = inet_dsfield_to_dscp(AMT_TOS);
1027 	fl4.flowi4_proto       = IPPROTO_UDP;
1028 	rt = ip_route_output_key(amt->net, &fl4);
1029 	if (IS_ERR(rt)) {
1030 		netdev_dbg(amt->dev, "no route to %pI4\n", &remote_ip);
1031 		return true;
1032 	}
1033 
1034 	amtmu			= skb_push(skb, sizeof(*amtmu));
1035 	amtmu->version		= 0;
1036 	amtmu->type		= AMT_MSG_MEMBERSHIP_UPDATE;
1037 	amtmu->reserved		= 0;
1038 	amtmu->nonce		= amt->nonce;
1039 	amtmu->response_mac	= amt->mac;
1040 
1041 	if (!v6)
1042 		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1043 	else
1044 		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1045 	udp_tunnel_xmit_skb(rt, sk, skb,
1046 			    fl4.saddr,
1047 			    fl4.daddr,
1048 			    AMT_TOS,
1049 			    ip4_dst_hoplimit(&rt->dst),
1050 			    0,
1051 			    amt->gw_port,
1052 			    amt->relay_port,
1053 			    false,
1054 			    false,
1055 			    0);
1056 	amt_update_gw_status(amt, AMT_STATUS_SENT_UPDATE, true);
1057 	return false;
1058 }
1059 
1060 static void amt_send_multicast_data(struct amt_dev *amt,
1061 				    const struct sk_buff *oskb,
1062 				    struct amt_tunnel_list *tunnel,
1063 				    bool v6)
1064 {
1065 	struct amt_header_mcast_data *amtmd;
1066 	struct sk_buff *skb;
1067 	struct iphdr *iph;
1068 	struct flowi4 fl4;
1069 	struct rtable *rt;
1070 	struct sock *sk;
1071 
1072 	sk = rcu_dereference_bh(amt->sk);
1073 	if (!sk)
1074 		return;
1075 
1076 	skb = skb_copy_expand(oskb, sizeof(*amtmd) + sizeof(*iph) +
1077 			      sizeof(struct udphdr), 0, GFP_ATOMIC);
1078 	if (!skb)
1079 		return;
1080 
1081 	skb_reset_inner_headers(skb);
1082 	memset(&fl4, 0, sizeof(struct flowi4));
1083 	fl4.flowi4_oif         = amt->stream_dev->ifindex;
1084 	fl4.daddr              = tunnel->ip4;
1085 	fl4.saddr              = amt->local_ip;
1086 	fl4.flowi4_proto       = IPPROTO_UDP;
1087 	rt = ip_route_output_key(amt->net, &fl4);
1088 	if (IS_ERR(rt)) {
1089 		netdev_dbg(amt->dev, "no route to %pI4\n", &tunnel->ip4);
1090 		kfree_skb(skb);
1091 		return;
1092 	}
1093 
1094 	amtmd = skb_push(skb, sizeof(*amtmd));
1095 	amtmd->version = 0;
1096 	amtmd->reserved = 0;
1097 	amtmd->type = AMT_MSG_MULTICAST_DATA;
1098 
1099 	if (!v6)
1100 		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1101 	else
1102 		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1103 	udp_tunnel_xmit_skb(rt, sk, skb,
1104 			    fl4.saddr,
1105 			    fl4.daddr,
1106 			    AMT_TOS,
1107 			    ip4_dst_hoplimit(&rt->dst),
1108 			    0,
1109 			    amt->relay_port,
1110 			    tunnel->source_port,
1111 			    false,
1112 			    false,
1113 			    0);
1114 }
1115 
1116 static bool amt_send_membership_query(struct amt_dev *amt,
1117 				      struct sk_buff *skb,
1118 				      struct amt_tunnel_list *tunnel,
1119 				      bool v6)
1120 {
1121 	struct amt_header_membership_query *amtmq;
1122 	struct rtable *rt;
1123 	struct flowi4 fl4;
1124 	struct sock *sk;
1125 	int err;
1126 
1127 	sk = rcu_dereference_bh(amt->sk);
1128 	if (!sk)
1129 		return true;
1130 
1131 	err = skb_cow_head(skb, LL_RESERVED_SPACE(amt->dev) + sizeof(*amtmq) +
1132 			   sizeof(struct iphdr) + sizeof(struct udphdr));
1133 	if (err)
1134 		return true;
1135 
1136 	skb_reset_inner_headers(skb);
1137 	memset(&fl4, 0, sizeof(struct flowi4));
1138 	fl4.flowi4_oif         = amt->stream_dev->ifindex;
1139 	fl4.daddr              = tunnel->ip4;
1140 	fl4.saddr              = amt->local_ip;
1141 	fl4.flowi4_dscp        = inet_dsfield_to_dscp(AMT_TOS);
1142 	fl4.flowi4_proto       = IPPROTO_UDP;
1143 	rt = ip_route_output_key(amt->net, &fl4);
1144 	if (IS_ERR(rt)) {
1145 		netdev_dbg(amt->dev, "no route to %pI4\n", &tunnel->ip4);
1146 		return true;
1147 	}
1148 
1149 	amtmq		= skb_push(skb, sizeof(*amtmq));
1150 	amtmq->version	= 0;
1151 	amtmq->type	= AMT_MSG_MEMBERSHIP_QUERY;
1152 	amtmq->reserved = 0;
1153 	amtmq->l	= 0;
1154 	amtmq->g	= 0;
1155 	amtmq->nonce	= tunnel->nonce;
1156 	amtmq->response_mac = tunnel->mac;
1157 
1158 	if (!v6)
1159 		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1160 	else
1161 		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1162 	udp_tunnel_xmit_skb(rt, sk, skb,
1163 			    fl4.saddr,
1164 			    fl4.daddr,
1165 			    AMT_TOS,
1166 			    ip4_dst_hoplimit(&rt->dst),
1167 			    0,
1168 			    amt->relay_port,
1169 			    tunnel->source_port,
1170 			    false,
1171 			    false,
1172 			    0);
1173 	amt_update_relay_status(tunnel, AMT_STATUS_SENT_QUERY, true);
1174 	return false;
1175 }
1176 
1177 static netdev_tx_t amt_dev_xmit(struct sk_buff *skb, struct net_device *dev)
1178 {
1179 	struct amt_dev *amt = netdev_priv(dev);
1180 	struct amt_tunnel_list *tunnel;
1181 	struct amt_group_node *gnode;
1182 	union amt_addr group = {0,};
1183 #if IS_ENABLED(CONFIG_IPV6)
1184 	struct ipv6hdr *ip6h;
1185 	struct mld_msg *mld;
1186 #endif
1187 	bool report = false;
1188 	struct igmphdr *ih;
1189 	bool query = false;
1190 	struct iphdr *iph;
1191 	bool data = false;
1192 	bool v6 = false;
1193 	u32 hash;
1194 
1195 	iph = ip_hdr(skb);
1196 	if (iph->version == 4) {
1197 		if (!ipv4_is_multicast(iph->daddr))
1198 			goto free;
1199 
1200 		if (!ip_mc_check_igmp(skb)) {
1201 			ih = igmp_hdr(skb);
1202 			switch (ih->type) {
1203 			case IGMPV3_HOST_MEMBERSHIP_REPORT:
1204 			case IGMP_HOST_MEMBERSHIP_REPORT:
1205 				report = true;
1206 				break;
1207 			case IGMP_HOST_MEMBERSHIP_QUERY:
1208 				query = true;
1209 				break;
1210 			default:
1211 				goto free;
1212 			}
1213 		} else {
1214 			data = true;
1215 		}
1216 		v6 = false;
1217 		group.ip4 = iph->daddr;
1218 #if IS_ENABLED(CONFIG_IPV6)
1219 	} else if (iph->version == 6) {
1220 		ip6h = ipv6_hdr(skb);
1221 		if (!ipv6_addr_is_multicast(&ip6h->daddr))
1222 			goto free;
1223 
1224 		if (!ipv6_mc_check_mld(skb)) {
1225 			mld = (struct mld_msg *)skb_transport_header(skb);
1226 			switch (mld->mld_type) {
1227 			case ICMPV6_MGM_REPORT:
1228 			case ICMPV6_MLD2_REPORT:
1229 				report = true;
1230 				break;
1231 			case ICMPV6_MGM_QUERY:
1232 				query = true;
1233 				break;
1234 			default:
1235 				goto free;
1236 			}
1237 		} else {
1238 			data = true;
1239 		}
1240 		v6 = true;
1241 		group.ip6 = ip6h->daddr;
1242 #endif
1243 	} else {
1244 		dev->stats.tx_errors++;
1245 		goto free;
1246 	}
1247 
1248 	if (!pskb_may_pull(skb, sizeof(struct ethhdr)))
1249 		goto free;
1250 
1251 	skb_pull(skb, sizeof(struct ethhdr));
1252 
1253 	if (amt->mode == AMT_MODE_GATEWAY) {
1254 		/* Gateway only passes IGMP/MLD packets */
1255 		if (!report)
1256 			goto free;
1257 		if ((!v6 && !READ_ONCE(amt->ready4)) ||
1258 		    (v6 && !READ_ONCE(amt->ready6)))
1259 			goto free;
1260 		if (amt_send_membership_update(amt, skb,  v6))
1261 			goto free;
1262 		goto unlock;
1263 	} else if (amt->mode == AMT_MODE_RELAY) {
1264 		if (query) {
1265 			tunnel = amt_skb_cb(skb)->tunnel;
1266 			if (!tunnel) {
1267 				WARN_ON(1);
1268 				goto free;
1269 			}
1270 
1271 			/* Do not forward unexpected query */
1272 			if (amt_send_membership_query(amt, skb, tunnel, v6))
1273 				goto free;
1274 			goto unlock;
1275 		}
1276 
1277 		if (!data)
1278 			goto free;
1279 		list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list) {
1280 			hash = amt_group_hash(tunnel, &group);
1281 			hlist_for_each_entry_rcu(gnode, &tunnel->groups[hash],
1282 						 node) {
1283 				if (!v6) {
1284 					if (gnode->group_addr.ip4 == iph->daddr)
1285 						goto found;
1286 #if IS_ENABLED(CONFIG_IPV6)
1287 				} else {
1288 					if (ipv6_addr_equal(&gnode->group_addr.ip6,
1289 							    &ip6h->daddr))
1290 						goto found;
1291 #endif
1292 				}
1293 			}
1294 			continue;
1295 found:
1296 			amt_send_multicast_data(amt, skb, tunnel, v6);
1297 		}
1298 	}
1299 
1300 	dev_kfree_skb(skb);
1301 	return NETDEV_TX_OK;
1302 free:
1303 	dev_kfree_skb(skb);
1304 unlock:
1305 	dev->stats.tx_dropped++;
1306 	return NETDEV_TX_OK;
1307 }
1308 
1309 static int amt_parse_type(struct sk_buff *skb)
1310 {
1311 	struct amt_header *amth;
1312 
1313 	if (!pskb_may_pull(skb, sizeof(struct udphdr) +
1314 			   sizeof(struct amt_header)))
1315 		return -1;
1316 
1317 	amth = (struct amt_header *)(udp_hdr(skb) + 1);
1318 
1319 	if (amth->version != 0)
1320 		return -1;
1321 
1322 	if (amth->type >= __AMT_MSG_MAX || !amth->type)
1323 		return -1;
1324 	return amth->type;
1325 }
1326 
1327 static void amt_clear_groups(struct amt_tunnel_list *tunnel)
1328 {
1329 	struct amt_dev *amt = tunnel->amt;
1330 	struct amt_group_node *gnode;
1331 	struct hlist_node *t;
1332 	int i;
1333 
1334 	spin_lock_bh(&tunnel->lock);
1335 	rcu_read_lock();
1336 	for (i = 0; i < amt->hash_buckets; i++)
1337 		hlist_for_each_entry_safe(gnode, t, &tunnel->groups[i], node)
1338 			amt_del_group(amt, gnode);
1339 	rcu_read_unlock();
1340 	spin_unlock_bh(&tunnel->lock);
1341 }
1342 
1343 static void amt_tunnel_expire(struct work_struct *work)
1344 {
1345 	struct amt_tunnel_list *tunnel = container_of(to_delayed_work(work),
1346 						      struct amt_tunnel_list,
1347 						      gc_wq);
1348 	struct amt_dev *amt = tunnel->amt;
1349 
1350 	spin_lock_bh(&amt->lock);
1351 	rcu_read_lock();
1352 	list_del_rcu(&tunnel->list);
1353 	amt->nr_tunnels--;
1354 	amt_clear_groups(tunnel);
1355 	rcu_read_unlock();
1356 	spin_unlock_bh(&amt->lock);
1357 	kfree_rcu(tunnel, rcu);
1358 }
1359 
1360 static void amt_cleanup_srcs(struct amt_dev *amt,
1361 			     struct amt_tunnel_list *tunnel,
1362 			     struct amt_group_node *gnode)
1363 {
1364 	struct amt_source_node *snode;
1365 	struct hlist_node *t;
1366 	int i;
1367 
1368 	/* Delete old sources */
1369 	for (i = 0; i < amt->hash_buckets; i++) {
1370 		hlist_for_each_entry_safe(snode, t, &gnode->sources[i], node) {
1371 			if (snode->flags == AMT_SOURCE_OLD)
1372 				amt_destroy_source(snode);
1373 		}
1374 	}
1375 
1376 	/* switch from new to old */
1377 	for (i = 0; i < amt->hash_buckets; i++)  {
1378 		hlist_for_each_entry_rcu(snode, &gnode->sources[i], node) {
1379 			snode->flags = AMT_SOURCE_OLD;
1380 			if (!gnode->v6)
1381 				netdev_dbg(snode->gnode->amt->dev,
1382 					   "Add source as OLD %pI4 from %pI4\n",
1383 					   &snode->source_addr.ip4,
1384 					   &gnode->group_addr.ip4);
1385 #if IS_ENABLED(CONFIG_IPV6)
1386 			else
1387 				netdev_dbg(snode->gnode->amt->dev,
1388 					   "Add source as OLD %pI6 from %pI6\n",
1389 					   &snode->source_addr.ip6,
1390 					   &gnode->group_addr.ip6);
1391 #endif
1392 		}
1393 	}
1394 }
1395 
1396 static void amt_add_srcs(struct amt_dev *amt, struct amt_tunnel_list *tunnel,
1397 			 struct amt_group_node *gnode, void *grec,
1398 			 bool v6)
1399 {
1400 	struct igmpv3_grec *igmp_grec;
1401 	struct amt_source_node *snode;
1402 #if IS_ENABLED(CONFIG_IPV6)
1403 	struct mld2_grec *mld_grec;
1404 #endif
1405 	union amt_addr src = {0,};
1406 	u16 nsrcs;
1407 	u32 hash;
1408 	int i;
1409 
1410 	if (!v6) {
1411 		igmp_grec = grec;
1412 		nsrcs = ntohs(igmp_grec->grec_nsrcs);
1413 	} else {
1414 #if IS_ENABLED(CONFIG_IPV6)
1415 		mld_grec = grec;
1416 		nsrcs = ntohs(mld_grec->grec_nsrcs);
1417 #else
1418 	return;
1419 #endif
1420 	}
1421 	for (i = 0; i < nsrcs; i++) {
1422 		if (tunnel->nr_sources >= amt->max_sources)
1423 			return;
1424 		if (!v6)
1425 			src.ip4 = igmp_grec->grec_src[i];
1426 #if IS_ENABLED(CONFIG_IPV6)
1427 		else
1428 			memcpy(&src.ip6, &mld_grec->grec_src[i],
1429 			       sizeof(struct in6_addr));
1430 #endif
1431 		if (amt_lookup_src(tunnel, gnode, AMT_FILTER_ALL, &src))
1432 			continue;
1433 
1434 		snode = amt_alloc_snode(gnode, &src);
1435 		if (snode) {
1436 			hash = amt_source_hash(tunnel, &snode->source_addr);
1437 			hlist_add_head_rcu(&snode->node, &gnode->sources[hash]);
1438 			tunnel->nr_sources++;
1439 			gnode->nr_sources++;
1440 
1441 			if (!gnode->v6)
1442 				netdev_dbg(snode->gnode->amt->dev,
1443 					   "Add source as NEW %pI4 from %pI4\n",
1444 					   &snode->source_addr.ip4,
1445 					   &gnode->group_addr.ip4);
1446 #if IS_ENABLED(CONFIG_IPV6)
1447 			else
1448 				netdev_dbg(snode->gnode->amt->dev,
1449 					   "Add source as NEW %pI6 from %pI6\n",
1450 					   &snode->source_addr.ip6,
1451 					   &gnode->group_addr.ip6);
1452 #endif
1453 		}
1454 	}
1455 }
1456 
1457 /* Router State   Report Rec'd New Router State
1458  * ------------   ------------ ----------------
1459  * EXCLUDE (X,Y)  IS_IN (A)    EXCLUDE (X+A,Y-A)
1460  *
1461  * -----------+-----------+-----------+
1462  *            |    OLD    |    NEW    |
1463  * -----------+-----------+-----------+
1464  *    FWD     |     X     |    X+A    |
1465  * -----------+-----------+-----------+
1466  *    D_FWD   |     Y     |    Y-A    |
1467  * -----------+-----------+-----------+
1468  *    NONE    |           |     A     |
1469  * -----------+-----------+-----------+
1470  *
1471  * a) Received sources are NONE/NEW
1472  * b) All NONE will be deleted by amt_cleanup_srcs().
1473  * c) All OLD will be deleted by amt_cleanup_srcs().
1474  * d) After delete, NEW source will be switched to OLD.
1475  */
1476 static void amt_lookup_act_srcs(struct amt_tunnel_list *tunnel,
1477 				struct amt_group_node *gnode,
1478 				void *grec,
1479 				enum amt_ops ops,
1480 				enum amt_filter filter,
1481 				enum amt_act act,
1482 				bool v6)
1483 {
1484 	struct amt_dev *amt = tunnel->amt;
1485 	struct amt_source_node *snode;
1486 	struct igmpv3_grec *igmp_grec;
1487 #if IS_ENABLED(CONFIG_IPV6)
1488 	struct mld2_grec *mld_grec;
1489 #endif
1490 	union amt_addr src = {0,};
1491 	struct hlist_node *t;
1492 	u16 nsrcs;
1493 	int i, j;
1494 
1495 	if (!v6) {
1496 		igmp_grec = grec;
1497 		nsrcs = ntohs(igmp_grec->grec_nsrcs);
1498 	} else {
1499 #if IS_ENABLED(CONFIG_IPV6)
1500 		mld_grec = grec;
1501 		nsrcs = ntohs(mld_grec->grec_nsrcs);
1502 #else
1503 	return;
1504 #endif
1505 	}
1506 
1507 	memset(&src, 0, sizeof(union amt_addr));
1508 	switch (ops) {
1509 	case AMT_OPS_INT:
1510 		/* A*B */
1511 		for (i = 0; i < nsrcs; i++) {
1512 			if (!v6)
1513 				src.ip4 = igmp_grec->grec_src[i];
1514 #if IS_ENABLED(CONFIG_IPV6)
1515 			else
1516 				memcpy(&src.ip6, &mld_grec->grec_src[i],
1517 				       sizeof(struct in6_addr));
1518 #endif
1519 			snode = amt_lookup_src(tunnel, gnode, filter, &src);
1520 			if (!snode)
1521 				continue;
1522 			amt_act_src(tunnel, gnode, snode, act);
1523 		}
1524 		break;
1525 	case AMT_OPS_UNI:
1526 		/* A+B */
1527 		for (i = 0; i < amt->hash_buckets; i++) {
1528 			hlist_for_each_entry_safe(snode, t, &gnode->sources[i],
1529 						  node) {
1530 				if (amt_status_filter(snode, filter))
1531 					amt_act_src(tunnel, gnode, snode, act);
1532 			}
1533 		}
1534 		for (i = 0; i < nsrcs; i++) {
1535 			if (!v6)
1536 				src.ip4 = igmp_grec->grec_src[i];
1537 #if IS_ENABLED(CONFIG_IPV6)
1538 			else
1539 				memcpy(&src.ip6, &mld_grec->grec_src[i],
1540 				       sizeof(struct in6_addr));
1541 #endif
1542 			snode = amt_lookup_src(tunnel, gnode, filter, &src);
1543 			if (!snode)
1544 				continue;
1545 			amt_act_src(tunnel, gnode, snode, act);
1546 		}
1547 		break;
1548 	case AMT_OPS_SUB:
1549 		/* A-B */
1550 		for (i = 0; i < amt->hash_buckets; i++) {
1551 			hlist_for_each_entry_safe(snode, t, &gnode->sources[i],
1552 						  node) {
1553 				if (!amt_status_filter(snode, filter))
1554 					continue;
1555 				for (j = 0; j < nsrcs; j++) {
1556 					if (!v6)
1557 						src.ip4 = igmp_grec->grec_src[j];
1558 #if IS_ENABLED(CONFIG_IPV6)
1559 					else
1560 						memcpy(&src.ip6,
1561 						       &mld_grec->grec_src[j],
1562 						       sizeof(struct in6_addr));
1563 #endif
1564 					if (amt_addr_equal(&snode->source_addr,
1565 							   &src))
1566 						goto out_sub;
1567 				}
1568 				amt_act_src(tunnel, gnode, snode, act);
1569 				continue;
1570 out_sub:;
1571 			}
1572 		}
1573 		break;
1574 	case AMT_OPS_SUB_REV:
1575 		/* B-A */
1576 		for (i = 0; i < nsrcs; i++) {
1577 			if (!v6)
1578 				src.ip4 = igmp_grec->grec_src[i];
1579 #if IS_ENABLED(CONFIG_IPV6)
1580 			else
1581 				memcpy(&src.ip6, &mld_grec->grec_src[i],
1582 				       sizeof(struct in6_addr));
1583 #endif
1584 			snode = amt_lookup_src(tunnel, gnode, AMT_FILTER_ALL,
1585 					       &src);
1586 			if (!snode) {
1587 				snode = amt_lookup_src(tunnel, gnode,
1588 						       filter, &src);
1589 				if (snode)
1590 					amt_act_src(tunnel, gnode, snode, act);
1591 			}
1592 		}
1593 		break;
1594 	default:
1595 		netdev_dbg(amt->dev, "Invalid type\n");
1596 		return;
1597 	}
1598 }
1599 
1600 static void amt_mcast_is_in_handler(struct amt_dev *amt,
1601 				    struct amt_tunnel_list *tunnel,
1602 				    struct amt_group_node *gnode,
1603 				    void *grec, void *zero_grec, bool v6)
1604 {
1605 	if (gnode->filter_mode == MCAST_INCLUDE) {
1606 /* Router State   Report Rec'd New Router State        Actions
1607  * ------------   ------------ ----------------        -------
1608  * INCLUDE (A)    IS_IN (B)    INCLUDE (A+B)           (B)=GMI
1609  */
1610 		/* Update IS_IN (B) as FWD/NEW */
1611 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1612 				    AMT_FILTER_NONE_NEW,
1613 				    AMT_ACT_STATUS_FWD_NEW,
1614 				    v6);
1615 		/* Update INCLUDE (A) as NEW */
1616 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1617 				    AMT_FILTER_FWD,
1618 				    AMT_ACT_STATUS_FWD_NEW,
1619 				    v6);
1620 		/* (B)=GMI */
1621 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1622 				    AMT_FILTER_FWD_NEW,
1623 				    AMT_ACT_GMI,
1624 				    v6);
1625 	} else {
1626 /* State        Actions
1627  * ------------   ------------ ----------------        -------
1628  * EXCLUDE (X,Y)  IS_IN (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1629  */
1630 		/* Update (A) in (X, Y) as NONE/NEW */
1631 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1632 				    AMT_FILTER_BOTH,
1633 				    AMT_ACT_STATUS_NONE_NEW,
1634 				    v6);
1635 		/* Update FWD/OLD as FWD/NEW */
1636 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1637 				    AMT_FILTER_FWD,
1638 				    AMT_ACT_STATUS_FWD_NEW,
1639 				    v6);
1640 		/* Update IS_IN (A) as FWD/NEW */
1641 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1642 				    AMT_FILTER_NONE_NEW,
1643 				    AMT_ACT_STATUS_FWD_NEW,
1644 				    v6);
1645 		/* Update EXCLUDE (, Y-A) as D_FWD_NEW */
1646 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB,
1647 				    AMT_FILTER_D_FWD,
1648 				    AMT_ACT_STATUS_D_FWD_NEW,
1649 				    v6);
1650 	}
1651 }
1652 
1653 static void amt_mcast_is_ex_handler(struct amt_dev *amt,
1654 				    struct amt_tunnel_list *tunnel,
1655 				    struct amt_group_node *gnode,
1656 				    void *grec, void *zero_grec, bool v6)
1657 {
1658 	if (gnode->filter_mode == MCAST_INCLUDE) {
1659 /* Router State   Report Rec'd  New Router State         Actions
1660  * ------------   ------------  ----------------         -------
1661  * INCLUDE (A)    IS_EX (B)     EXCLUDE (A*B,B-A)        (B-A)=0
1662  *                                                       Delete (A-B)
1663  *                                                       Group Timer=GMI
1664  */
1665 		/* EXCLUDE(A*B, ) */
1666 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1667 				    AMT_FILTER_FWD,
1668 				    AMT_ACT_STATUS_FWD_NEW,
1669 				    v6);
1670 		/* EXCLUDE(, B-A) */
1671 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1672 				    AMT_FILTER_FWD,
1673 				    AMT_ACT_STATUS_D_FWD_NEW,
1674 				    v6);
1675 		/* (B-A)=0 */
1676 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1677 				    AMT_FILTER_D_FWD_NEW,
1678 				    AMT_ACT_GMI_ZERO,
1679 				    v6);
1680 		/* Group Timer=GMI */
1681 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1682 				      msecs_to_jiffies(amt_gmi(amt))))
1683 			dev_hold(amt->dev);
1684 		gnode->filter_mode = MCAST_EXCLUDE;
1685 		/* Delete (A-B) will be worked by amt_cleanup_srcs(). */
1686 	} else {
1687 /* Router State   Report Rec'd  New Router State	Actions
1688  * ------------   ------------  ----------------	-------
1689  * EXCLUDE (X,Y)  IS_EX (A)     EXCLUDE (A-Y,Y*A)	(A-X-Y)=GMI
1690  *							Delete (X-A)
1691  *							Delete (Y-A)
1692  *							Group Timer=GMI
1693  */
1694 		/* EXCLUDE (A-Y, ) */
1695 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1696 				    AMT_FILTER_D_FWD,
1697 				    AMT_ACT_STATUS_FWD_NEW,
1698 				    v6);
1699 		/* EXCLUDE (, Y*A ) */
1700 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1701 				    AMT_FILTER_D_FWD,
1702 				    AMT_ACT_STATUS_D_FWD_NEW,
1703 				    v6);
1704 		/* (A-X-Y)=GMI */
1705 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1706 				    AMT_FILTER_BOTH_NEW,
1707 				    AMT_ACT_GMI,
1708 				    v6);
1709 		/* Group Timer=GMI */
1710 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1711 				      msecs_to_jiffies(amt_gmi(amt))))
1712 			dev_hold(amt->dev);
1713 		/* Delete (X-A), (Y-A) will be worked by amt_cleanup_srcs(). */
1714 	}
1715 }
1716 
1717 static void amt_mcast_to_in_handler(struct amt_dev *amt,
1718 				    struct amt_tunnel_list *tunnel,
1719 				    struct amt_group_node *gnode,
1720 				    void *grec, void *zero_grec, bool v6)
1721 {
1722 	if (gnode->filter_mode == MCAST_INCLUDE) {
1723 /* Router State   Report Rec'd New Router State        Actions
1724  * ------------   ------------ ----------------        -------
1725  * INCLUDE (A)    TO_IN (B)    INCLUDE (A+B)           (B)=GMI
1726  *						       Send Q(G,A-B)
1727  */
1728 		/* Update TO_IN (B) sources as FWD/NEW */
1729 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1730 				    AMT_FILTER_NONE_NEW,
1731 				    AMT_ACT_STATUS_FWD_NEW,
1732 				    v6);
1733 		/* Update INCLUDE (A) sources as NEW */
1734 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1735 				    AMT_FILTER_FWD,
1736 				    AMT_ACT_STATUS_FWD_NEW,
1737 				    v6);
1738 		/* (B)=GMI */
1739 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1740 				    AMT_FILTER_FWD_NEW,
1741 				    AMT_ACT_GMI,
1742 				    v6);
1743 	} else {
1744 /* Router State   Report Rec'd New Router State        Actions
1745  * ------------   ------------ ----------------        -------
1746  * EXCLUDE (X,Y)  TO_IN (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1747  *						       Send Q(G,X-A)
1748  *						       Send Q(G)
1749  */
1750 		/* Update TO_IN (A) sources as FWD/NEW */
1751 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1752 				    AMT_FILTER_NONE_NEW,
1753 				    AMT_ACT_STATUS_FWD_NEW,
1754 				    v6);
1755 		/* Update EXCLUDE(X,) sources as FWD/NEW */
1756 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1757 				    AMT_FILTER_FWD,
1758 				    AMT_ACT_STATUS_FWD_NEW,
1759 				    v6);
1760 		/* EXCLUDE (, Y-A)
1761 		 * (A) are already switched to FWD_NEW.
1762 		 * So, D_FWD/OLD -> D_FWD/NEW is okay.
1763 		 */
1764 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1765 				    AMT_FILTER_D_FWD,
1766 				    AMT_ACT_STATUS_D_FWD_NEW,
1767 				    v6);
1768 		/* (A)=GMI
1769 		 * Only FWD_NEW will have (A) sources.
1770 		 */
1771 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1772 				    AMT_FILTER_FWD_NEW,
1773 				    AMT_ACT_GMI,
1774 				    v6);
1775 	}
1776 }
1777 
1778 static void amt_mcast_to_ex_handler(struct amt_dev *amt,
1779 				    struct amt_tunnel_list *tunnel,
1780 				    struct amt_group_node *gnode,
1781 				    void *grec, void *zero_grec, bool v6)
1782 {
1783 	if (gnode->filter_mode == MCAST_INCLUDE) {
1784 /* Router State   Report Rec'd New Router State        Actions
1785  * ------------   ------------ ----------------        -------
1786  * INCLUDE (A)    TO_EX (B)    EXCLUDE (A*B,B-A)       (B-A)=0
1787  *						       Delete (A-B)
1788  *						       Send Q(G,A*B)
1789  *						       Group Timer=GMI
1790  */
1791 		/* EXCLUDE (A*B, ) */
1792 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1793 				    AMT_FILTER_FWD,
1794 				    AMT_ACT_STATUS_FWD_NEW,
1795 				    v6);
1796 		/* EXCLUDE (, B-A) */
1797 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1798 				    AMT_FILTER_FWD,
1799 				    AMT_ACT_STATUS_D_FWD_NEW,
1800 				    v6);
1801 		/* (B-A)=0 */
1802 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1803 				    AMT_FILTER_D_FWD_NEW,
1804 				    AMT_ACT_GMI_ZERO,
1805 				    v6);
1806 		/* Group Timer=GMI */
1807 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1808 				      msecs_to_jiffies(amt_gmi(amt))))
1809 			dev_hold(amt->dev);
1810 		gnode->filter_mode = MCAST_EXCLUDE;
1811 		/* Delete (A-B) will be worked by amt_cleanup_srcs(). */
1812 	} else {
1813 /* Router State   Report Rec'd New Router State        Actions
1814  * ------------   ------------ ----------------        -------
1815  * EXCLUDE (X,Y)  TO_EX (A)    EXCLUDE (A-Y,Y*A)       (A-X-Y)=Group Timer
1816  *						       Delete (X-A)
1817  *						       Delete (Y-A)
1818  *						       Send Q(G,A-Y)
1819  *						       Group Timer=GMI
1820  */
1821 		/* Update (A-X-Y) as NONE/OLD */
1822 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1823 				    AMT_FILTER_BOTH,
1824 				    AMT_ACT_GT,
1825 				    v6);
1826 		/* EXCLUDE (A-Y, ) */
1827 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1828 				    AMT_FILTER_D_FWD,
1829 				    AMT_ACT_STATUS_FWD_NEW,
1830 				    v6);
1831 		/* EXCLUDE (, Y*A) */
1832 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1833 				    AMT_FILTER_D_FWD,
1834 				    AMT_ACT_STATUS_D_FWD_NEW,
1835 				    v6);
1836 		/* Group Timer=GMI */
1837 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1838 				      msecs_to_jiffies(amt_gmi(amt))))
1839 			dev_hold(amt->dev);
1840 		/* Delete (X-A), (Y-A) will be worked by amt_cleanup_srcs(). */
1841 	}
1842 }
1843 
1844 static void amt_mcast_allow_handler(struct amt_dev *amt,
1845 				    struct amt_tunnel_list *tunnel,
1846 				    struct amt_group_node *gnode,
1847 				    void *grec, void *zero_grec, bool v6)
1848 {
1849 	if (gnode->filter_mode == MCAST_INCLUDE) {
1850 /* Router State   Report Rec'd New Router State        Actions
1851  * ------------   ------------ ----------------        -------
1852  * INCLUDE (A)    ALLOW (B)    INCLUDE (A+B)	       (B)=GMI
1853  */
1854 		/* INCLUDE (A+B) */
1855 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1856 				    AMT_FILTER_FWD,
1857 				    AMT_ACT_STATUS_FWD_NEW,
1858 				    v6);
1859 		/* (B)=GMI */
1860 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1861 				    AMT_FILTER_FWD_NEW,
1862 				    AMT_ACT_GMI,
1863 				    v6);
1864 	} else {
1865 /* Router State   Report Rec'd New Router State        Actions
1866  * ------------   ------------ ----------------        -------
1867  * EXCLUDE (X,Y)  ALLOW (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1868  */
1869 		/* EXCLUDE (X+A, ) */
1870 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1871 				    AMT_FILTER_FWD,
1872 				    AMT_ACT_STATUS_FWD_NEW,
1873 				    v6);
1874 		/* EXCLUDE (, Y-A) */
1875 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB,
1876 				    AMT_FILTER_D_FWD,
1877 				    AMT_ACT_STATUS_D_FWD_NEW,
1878 				    v6);
1879 		/* (A)=GMI
1880 		 * All (A) source are now FWD/NEW status.
1881 		 */
1882 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1883 				    AMT_FILTER_FWD_NEW,
1884 				    AMT_ACT_GMI,
1885 				    v6);
1886 	}
1887 }
1888 
1889 static void amt_mcast_block_handler(struct amt_dev *amt,
1890 				    struct amt_tunnel_list *tunnel,
1891 				    struct amt_group_node *gnode,
1892 				    void *grec, void *zero_grec, bool v6)
1893 {
1894 	if (gnode->filter_mode == MCAST_INCLUDE) {
1895 /* Router State   Report Rec'd New Router State        Actions
1896  * ------------   ------------ ----------------        -------
1897  * INCLUDE (A)    BLOCK (B)    INCLUDE (A)             Send Q(G,A*B)
1898  */
1899 		/* INCLUDE (A) */
1900 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1901 				    AMT_FILTER_FWD,
1902 				    AMT_ACT_STATUS_FWD_NEW,
1903 				    v6);
1904 	} else {
1905 /* Router State   Report Rec'd New Router State        Actions
1906  * ------------   ------------ ----------------        -------
1907  * EXCLUDE (X,Y)  BLOCK (A)    EXCLUDE (X+(A-Y),Y)     (A-X-Y)=Group Timer
1908  *						       Send Q(G,A-Y)
1909  */
1910 		/* (A-X-Y)=Group Timer */
1911 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1912 				    AMT_FILTER_BOTH,
1913 				    AMT_ACT_GT,
1914 				    v6);
1915 		/* EXCLUDE (X, ) */
1916 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1917 				    AMT_FILTER_FWD,
1918 				    AMT_ACT_STATUS_FWD_NEW,
1919 				    v6);
1920 		/* EXCLUDE (X+(A-Y) */
1921 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1922 				    AMT_FILTER_D_FWD,
1923 				    AMT_ACT_STATUS_FWD_NEW,
1924 				    v6);
1925 		/* EXCLUDE (, Y) */
1926 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1927 				    AMT_FILTER_D_FWD,
1928 				    AMT_ACT_STATUS_D_FWD_NEW,
1929 				    v6);
1930 	}
1931 }
1932 
1933 /* RFC 3376
1934  * 7.3.2. In the Presence of Older Version Group Members
1935  *
1936  * When Group Compatibility Mode is IGMPv2, a router internally
1937  * translates the following IGMPv2 messages for that group to their
1938  * IGMPv3 equivalents:
1939  *
1940  * IGMPv2 Message                IGMPv3 Equivalent
1941  * --------------                -----------------
1942  * Report                        IS_EX( {} )
1943  * Leave                         TO_IN( {} )
1944  */
1945 static void amt_igmpv2_report_handler(struct amt_dev *amt, struct sk_buff *skb,
1946 				      struct amt_tunnel_list *tunnel)
1947 {
1948 	struct igmphdr *ih = igmp_hdr(skb);
1949 	struct iphdr *iph = ip_hdr(skb);
1950 	struct amt_group_node *gnode;
1951 	union amt_addr group, host;
1952 
1953 	memset(&group, 0, sizeof(union amt_addr));
1954 	group.ip4 = ih->group;
1955 	memset(&host, 0, sizeof(union amt_addr));
1956 	host.ip4 = iph->saddr;
1957 
1958 	gnode = amt_lookup_group(tunnel, &group, &host, false);
1959 	if (!gnode) {
1960 		gnode = amt_add_group(amt, tunnel, &group, &host, false);
1961 		if (!IS_ERR(gnode)) {
1962 			gnode->filter_mode = MCAST_EXCLUDE;
1963 			if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1964 					      msecs_to_jiffies(amt_gmi(amt))))
1965 				dev_hold(amt->dev);
1966 		}
1967 	}
1968 }
1969 
1970 /* RFC 3376
1971  * 7.3.2. In the Presence of Older Version Group Members
1972  *
1973  * When Group Compatibility Mode is IGMPv2, a router internally
1974  * translates the following IGMPv2 messages for that group to their
1975  * IGMPv3 equivalents:
1976  *
1977  * IGMPv2 Message                IGMPv3 Equivalent
1978  * --------------                -----------------
1979  * Report                        IS_EX( {} )
1980  * Leave                         TO_IN( {} )
1981  */
1982 static void amt_igmpv2_leave_handler(struct amt_dev *amt, struct sk_buff *skb,
1983 				     struct amt_tunnel_list *tunnel)
1984 {
1985 	struct igmphdr *ih = igmp_hdr(skb);
1986 	struct iphdr *iph = ip_hdr(skb);
1987 	struct amt_group_node *gnode;
1988 	union amt_addr group, host;
1989 
1990 	memset(&group, 0, sizeof(union amt_addr));
1991 	group.ip4 = ih->group;
1992 	memset(&host, 0, sizeof(union amt_addr));
1993 	host.ip4 = iph->saddr;
1994 
1995 	gnode = amt_lookup_group(tunnel, &group, &host, false);
1996 	if (gnode)
1997 		amt_del_group(amt, gnode);
1998 }
1999 
2000 static void amt_igmpv3_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2001 				      struct amt_tunnel_list *tunnel)
2002 {
2003 	struct igmpv3_report *ihrv3 = igmpv3_report_hdr(skb);
2004 	int len = skb_transport_offset(skb) + sizeof(*ihrv3);
2005 	void *zero_grec = (void *)&igmpv3_zero_grec;
2006 	struct iphdr *iph = ip_hdr(skb);
2007 	struct amt_group_node *gnode;
2008 	union amt_addr group, host;
2009 	struct igmpv3_grec *grec;
2010 	u16 nsrcs;
2011 	int i;
2012 
2013 	for (i = 0; i < ntohs(ihrv3->ngrec); i++) {
2014 		len += sizeof(*grec);
2015 		if (!ip_mc_may_pull(skb, len))
2016 			break;
2017 
2018 		grec = (void *)(skb->data + len - sizeof(*grec));
2019 		nsrcs = ntohs(grec->grec_nsrcs);
2020 
2021 		len += nsrcs * sizeof(__be32);
2022 		if (!ip_mc_may_pull(skb, len))
2023 			break;
2024 
2025 		memset(&group, 0, sizeof(union amt_addr));
2026 		group.ip4 = grec->grec_mca;
2027 		memset(&host, 0, sizeof(union amt_addr));
2028 		host.ip4 = iph->saddr;
2029 		gnode = amt_lookup_group(tunnel, &group, &host, false);
2030 		if (!gnode) {
2031 			gnode = amt_add_group(amt, tunnel, &group, &host,
2032 					      false);
2033 			if (IS_ERR(gnode))
2034 				continue;
2035 		}
2036 
2037 		amt_add_srcs(amt, tunnel, gnode, grec, false);
2038 		switch (grec->grec_type) {
2039 		case IGMPV3_MODE_IS_INCLUDE:
2040 			amt_mcast_is_in_handler(amt, tunnel, gnode, grec,
2041 						zero_grec, false);
2042 			break;
2043 		case IGMPV3_MODE_IS_EXCLUDE:
2044 			amt_mcast_is_ex_handler(amt, tunnel, gnode, grec,
2045 						zero_grec, false);
2046 			break;
2047 		case IGMPV3_CHANGE_TO_INCLUDE:
2048 			amt_mcast_to_in_handler(amt, tunnel, gnode, grec,
2049 						zero_grec, false);
2050 			break;
2051 		case IGMPV3_CHANGE_TO_EXCLUDE:
2052 			amt_mcast_to_ex_handler(amt, tunnel, gnode, grec,
2053 						zero_grec, false);
2054 			break;
2055 		case IGMPV3_ALLOW_NEW_SOURCES:
2056 			amt_mcast_allow_handler(amt, tunnel, gnode, grec,
2057 						zero_grec, false);
2058 			break;
2059 		case IGMPV3_BLOCK_OLD_SOURCES:
2060 			amt_mcast_block_handler(amt, tunnel, gnode, grec,
2061 						zero_grec, false);
2062 			break;
2063 		default:
2064 			break;
2065 		}
2066 		amt_cleanup_srcs(amt, tunnel, gnode);
2067 	}
2068 }
2069 
2070 /* caller held tunnel->lock */
2071 static void amt_igmp_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2072 				    struct amt_tunnel_list *tunnel)
2073 {
2074 	struct igmphdr *ih = igmp_hdr(skb);
2075 
2076 	switch (ih->type) {
2077 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
2078 		amt_igmpv3_report_handler(amt, skb, tunnel);
2079 		break;
2080 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
2081 		amt_igmpv2_report_handler(amt, skb, tunnel);
2082 		break;
2083 	case IGMP_HOST_LEAVE_MESSAGE:
2084 		amt_igmpv2_leave_handler(amt, skb, tunnel);
2085 		break;
2086 	default:
2087 		break;
2088 	}
2089 }
2090 
2091 #if IS_ENABLED(CONFIG_IPV6)
2092 /* RFC 3810
2093  * 8.3.2. In the Presence of MLDv1 Multicast Address Listeners
2094  *
2095  * When Multicast Address Compatibility Mode is MLDv2, a router acts
2096  * using the MLDv2 protocol for that multicast address.  When Multicast
2097  * Address Compatibility Mode is MLDv1, a router internally translates
2098  * the following MLDv1 messages for that multicast address to their
2099  * MLDv2 equivalents:
2100  *
2101  * MLDv1 Message                 MLDv2 Equivalent
2102  * --------------                -----------------
2103  * Report                        IS_EX( {} )
2104  * Done                          TO_IN( {} )
2105  */
2106 static void amt_mldv1_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2107 				     struct amt_tunnel_list *tunnel)
2108 {
2109 	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2110 	struct ipv6hdr *ip6h = ipv6_hdr(skb);
2111 	struct amt_group_node *gnode;
2112 	union amt_addr group, host;
2113 
2114 	memcpy(&group.ip6, &mld->mld_mca, sizeof(struct in6_addr));
2115 	memcpy(&host.ip6, &ip6h->saddr, sizeof(struct in6_addr));
2116 
2117 	gnode = amt_lookup_group(tunnel, &group, &host, true);
2118 	if (!gnode) {
2119 		gnode = amt_add_group(amt, tunnel, &group, &host, true);
2120 		if (!IS_ERR(gnode)) {
2121 			gnode->filter_mode = MCAST_EXCLUDE;
2122 			if (!mod_delayed_work(amt_wq, &gnode->group_timer,
2123 					      msecs_to_jiffies(amt_gmi(amt))))
2124 				dev_hold(amt->dev);
2125 		}
2126 	}
2127 }
2128 
2129 /* RFC 3810
2130  * 8.3.2. In the Presence of MLDv1 Multicast Address Listeners
2131  *
2132  * When Multicast Address Compatibility Mode is MLDv2, a router acts
2133  * using the MLDv2 protocol for that multicast address.  When Multicast
2134  * Address Compatibility Mode is MLDv1, a router internally translates
2135  * the following MLDv1 messages for that multicast address to their
2136  * MLDv2 equivalents:
2137  *
2138  * MLDv1 Message                 MLDv2 Equivalent
2139  * --------------                -----------------
2140  * Report                        IS_EX( {} )
2141  * Done                          TO_IN( {} )
2142  */
2143 static void amt_mldv1_leave_handler(struct amt_dev *amt, struct sk_buff *skb,
2144 				    struct amt_tunnel_list *tunnel)
2145 {
2146 	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2147 	struct iphdr *iph = ip_hdr(skb);
2148 	struct amt_group_node *gnode;
2149 	union amt_addr group, host;
2150 
2151 	memcpy(&group.ip6, &mld->mld_mca, sizeof(struct in6_addr));
2152 	memset(&host, 0, sizeof(union amt_addr));
2153 	host.ip4 = iph->saddr;
2154 
2155 	gnode = amt_lookup_group(tunnel, &group, &host, true);
2156 	if (gnode) {
2157 		amt_del_group(amt, gnode);
2158 		return;
2159 	}
2160 }
2161 
2162 static void amt_mldv2_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2163 				     struct amt_tunnel_list *tunnel)
2164 {
2165 	struct mld2_report *mld2r = (struct mld2_report *)icmp6_hdr(skb);
2166 	int len = skb_transport_offset(skb) + sizeof(*mld2r);
2167 	void *zero_grec = (void *)&mldv2_zero_grec;
2168 	struct ipv6hdr *ip6h = ipv6_hdr(skb);
2169 	struct amt_group_node *gnode;
2170 	union amt_addr group, host;
2171 	struct mld2_grec *grec;
2172 	u16 nsrcs;
2173 	int i;
2174 
2175 	for (i = 0; i < ntohs(mld2r->mld2r_ngrec); i++) {
2176 		len += sizeof(*grec);
2177 		if (!ipv6_mc_may_pull(skb, len))
2178 			break;
2179 
2180 		grec = (void *)(skb->data + len - sizeof(*grec));
2181 		nsrcs = ntohs(grec->grec_nsrcs);
2182 
2183 		len += nsrcs * sizeof(struct in6_addr);
2184 		if (!ipv6_mc_may_pull(skb, len))
2185 			break;
2186 
2187 		memset(&group, 0, sizeof(union amt_addr));
2188 		group.ip6 = grec->grec_mca;
2189 		memset(&host, 0, sizeof(union amt_addr));
2190 		host.ip6 = ip6h->saddr;
2191 		gnode = amt_lookup_group(tunnel, &group, &host, true);
2192 		if (!gnode) {
2193 			gnode = amt_add_group(amt, tunnel, &group, &host,
2194 					      ETH_P_IPV6);
2195 			if (IS_ERR(gnode))
2196 				continue;
2197 		}
2198 
2199 		amt_add_srcs(amt, tunnel, gnode, grec, true);
2200 		switch (grec->grec_type) {
2201 		case MLD2_MODE_IS_INCLUDE:
2202 			amt_mcast_is_in_handler(amt, tunnel, gnode, grec,
2203 						zero_grec, true);
2204 			break;
2205 		case MLD2_MODE_IS_EXCLUDE:
2206 			amt_mcast_is_ex_handler(amt, tunnel, gnode, grec,
2207 						zero_grec, true);
2208 			break;
2209 		case MLD2_CHANGE_TO_INCLUDE:
2210 			amt_mcast_to_in_handler(amt, tunnel, gnode, grec,
2211 						zero_grec, true);
2212 			break;
2213 		case MLD2_CHANGE_TO_EXCLUDE:
2214 			amt_mcast_to_ex_handler(amt, tunnel, gnode, grec,
2215 						zero_grec, true);
2216 			break;
2217 		case MLD2_ALLOW_NEW_SOURCES:
2218 			amt_mcast_allow_handler(amt, tunnel, gnode, grec,
2219 						zero_grec, true);
2220 			break;
2221 		case MLD2_BLOCK_OLD_SOURCES:
2222 			amt_mcast_block_handler(amt, tunnel, gnode, grec,
2223 						zero_grec, true);
2224 			break;
2225 		default:
2226 			break;
2227 		}
2228 		amt_cleanup_srcs(amt, tunnel, gnode);
2229 	}
2230 }
2231 
2232 /* caller held tunnel->lock */
2233 static void amt_mld_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2234 				   struct amt_tunnel_list *tunnel)
2235 {
2236 	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2237 
2238 	switch (mld->mld_type) {
2239 	case ICMPV6_MGM_REPORT:
2240 		amt_mldv1_report_handler(amt, skb, tunnel);
2241 		break;
2242 	case ICMPV6_MLD2_REPORT:
2243 		amt_mldv2_report_handler(amt, skb, tunnel);
2244 		break;
2245 	case ICMPV6_MGM_REDUCTION:
2246 		amt_mldv1_leave_handler(amt, skb, tunnel);
2247 		break;
2248 	default:
2249 		break;
2250 	}
2251 }
2252 #endif
2253 
2254 static bool amt_advertisement_handler(struct amt_dev *amt, struct sk_buff *skb)
2255 {
2256 	struct amt_header_advertisement *amta;
2257 	int hdr_size;
2258 
2259 	hdr_size = sizeof(*amta) + sizeof(struct udphdr);
2260 	if (!pskb_may_pull(skb, hdr_size))
2261 		return true;
2262 
2263 	amta = (struct amt_header_advertisement *)(udp_hdr(skb) + 1);
2264 	if (!amta->ip4)
2265 		return true;
2266 
2267 	if (amta->reserved || amta->version)
2268 		return true;
2269 
2270 	if (ipv4_is_loopback(amta->ip4) || ipv4_is_multicast(amta->ip4) ||
2271 	    ipv4_is_zeronet(amta->ip4))
2272 		return true;
2273 
2274 	if (amt->status != AMT_STATUS_SENT_DISCOVERY ||
2275 	    amt->nonce != amta->nonce)
2276 		return true;
2277 
2278 	WRITE_ONCE(amt->remote_ip, amta->ip4);
2279 	netdev_dbg(amt->dev, "advertised remote ip = %pI4\n", &amta->ip4);
2280 	mod_delayed_work(amt_wq, &amt->req_wq, 0);
2281 
2282 	amt_update_gw_status(amt, AMT_STATUS_RECEIVED_ADVERTISEMENT, true);
2283 	return false;
2284 }
2285 
2286 static bool amt_multicast_data_handler(struct amt_dev *amt, struct sk_buff *skb)
2287 {
2288 	struct amt_header_mcast_data *amtmd;
2289 	int hdr_size, len, err;
2290 	struct ethhdr *eth;
2291 	struct iphdr *iph;
2292 
2293 	if (READ_ONCE(amt->status) != AMT_STATUS_SENT_UPDATE)
2294 		return true;
2295 
2296 	hdr_size = sizeof(*amtmd) + sizeof(struct udphdr);
2297 	if (!pskb_may_pull(skb, hdr_size))
2298 		return true;
2299 
2300 	amtmd = (struct amt_header_mcast_data *)(udp_hdr(skb) + 1);
2301 	if (amtmd->reserved || amtmd->version)
2302 		return true;
2303 
2304 	if (iptunnel_pull_header(skb, hdr_size, htons(ETH_P_IP), false))
2305 		return true;
2306 
2307 	skb_reset_network_header(skb);
2308 	skb_push(skb, sizeof(*eth));
2309 	skb_reset_mac_header(skb);
2310 	skb_pull(skb, sizeof(*eth));
2311 	eth = eth_hdr(skb);
2312 
2313 	if (!pskb_may_pull(skb, sizeof(*iph)))
2314 		return true;
2315 	iph = ip_hdr(skb);
2316 
2317 	if (iph->version == 4) {
2318 		if (!ipv4_is_multicast(iph->daddr))
2319 			return true;
2320 		skb->protocol = htons(ETH_P_IP);
2321 		eth->h_proto = htons(ETH_P_IP);
2322 		ip_eth_mc_map(iph->daddr, eth->h_dest);
2323 #if IS_ENABLED(CONFIG_IPV6)
2324 	} else if (iph->version == 6) {
2325 		struct ipv6hdr *ip6h;
2326 
2327 		if (!pskb_may_pull(skb, sizeof(*ip6h)))
2328 			return true;
2329 
2330 		ip6h = ipv6_hdr(skb);
2331 		if (!ipv6_addr_is_multicast(&ip6h->daddr))
2332 			return true;
2333 		skb->protocol = htons(ETH_P_IPV6);
2334 		eth->h_proto = htons(ETH_P_IPV6);
2335 		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2336 #endif
2337 	} else {
2338 		return true;
2339 	}
2340 
2341 	skb->pkt_type = PACKET_MULTICAST;
2342 	skb->ip_summed = CHECKSUM_NONE;
2343 	len = skb->len;
2344 	err = gro_cells_receive(&amt->gro_cells, skb);
2345 	if (likely(err == NET_RX_SUCCESS))
2346 		dev_sw_netstats_rx_add(amt->dev, len);
2347 	else
2348 		amt->dev->stats.rx_dropped++;
2349 
2350 	return false;
2351 }
2352 
2353 static bool amt_membership_query_handler(struct amt_dev *amt,
2354 					 struct sk_buff *skb)
2355 {
2356 	struct amt_header_membership_query *amtmq;
2357 	struct igmpv3_query *ihv3;
2358 	struct ethhdr *eth, *oeth;
2359 	struct iphdr *iph;
2360 	int hdr_size, len;
2361 
2362 	hdr_size = sizeof(*amtmq) + sizeof(struct udphdr);
2363 	if (!pskb_may_pull(skb, hdr_size))
2364 		return true;
2365 
2366 	amtmq = (struct amt_header_membership_query *)(udp_hdr(skb) + 1);
2367 	if (amtmq->reserved || amtmq->version)
2368 		return true;
2369 
2370 	if (amtmq->nonce != amt->nonce)
2371 		return true;
2372 
2373 	hdr_size -= sizeof(*eth);
2374 	if (iptunnel_pull_header(skb, hdr_size, htons(ETH_P_TEB), false))
2375 		return true;
2376 
2377 	oeth = eth_hdr(skb);
2378 	skb_reset_mac_header(skb);
2379 	skb_pull(skb, sizeof(*eth));
2380 	skb_reset_network_header(skb);
2381 	eth = eth_hdr(skb);
2382 	if (!pskb_may_pull(skb, sizeof(*iph)))
2383 		return true;
2384 
2385 	iph = ip_hdr(skb);
2386 	if (iph->version == 4) {
2387 		if (READ_ONCE(amt->ready4))
2388 			return true;
2389 
2390 		if (!pskb_may_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS +
2391 				   sizeof(*ihv3)))
2392 			return true;
2393 
2394 		if (!ipv4_is_multicast(iph->daddr))
2395 			return true;
2396 
2397 		ihv3 = skb_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
2398 		skb_reset_transport_header(skb);
2399 		skb_push(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
2400 		WRITE_ONCE(amt->ready4, true);
2401 		amt->mac = amtmq->response_mac;
2402 		amt->req_cnt = 0;
2403 		amt->qi = ihv3->qqic;
2404 		skb->protocol = htons(ETH_P_IP);
2405 		eth->h_proto = htons(ETH_P_IP);
2406 		ip_eth_mc_map(iph->daddr, eth->h_dest);
2407 #if IS_ENABLED(CONFIG_IPV6)
2408 	} else if (iph->version == 6) {
2409 		struct mld2_query *mld2q;
2410 		struct ipv6hdr *ip6h;
2411 
2412 		if (READ_ONCE(amt->ready6))
2413 			return true;
2414 
2415 		if (!pskb_may_pull(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS +
2416 				   sizeof(*mld2q)))
2417 			return true;
2418 
2419 		ip6h = ipv6_hdr(skb);
2420 		if (!ipv6_addr_is_multicast(&ip6h->daddr))
2421 			return true;
2422 
2423 		mld2q = skb_pull(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS);
2424 		skb_reset_transport_header(skb);
2425 		skb_push(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS);
2426 		WRITE_ONCE(amt->ready6, true);
2427 		amt->mac = amtmq->response_mac;
2428 		amt->req_cnt = 0;
2429 		amt->qi = mld2q->mld2q_qqic;
2430 		skb->protocol = htons(ETH_P_IPV6);
2431 		eth->h_proto = htons(ETH_P_IPV6);
2432 		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2433 #endif
2434 	} else {
2435 		return true;
2436 	}
2437 
2438 	ether_addr_copy(eth->h_source, oeth->h_source);
2439 	skb->pkt_type = PACKET_MULTICAST;
2440 	skb->ip_summed = CHECKSUM_NONE;
2441 	len = skb->len;
2442 	local_bh_disable();
2443 	if (__netif_rx(skb) == NET_RX_SUCCESS) {
2444 		amt_update_gw_status(amt, AMT_STATUS_RECEIVED_QUERY, true);
2445 		dev_sw_netstats_rx_add(amt->dev, len);
2446 	} else {
2447 		amt->dev->stats.rx_dropped++;
2448 	}
2449 	local_bh_enable();
2450 
2451 	return false;
2452 }
2453 
2454 static bool amt_update_handler(struct amt_dev *amt, struct sk_buff *skb)
2455 {
2456 	struct amt_header_membership_update *amtmu;
2457 	struct amt_tunnel_list *tunnel;
2458 	struct ethhdr *eth;
2459 	struct iphdr *iph;
2460 	int len, hdr_size;
2461 
2462 	iph = ip_hdr(skb);
2463 
2464 	hdr_size = sizeof(*amtmu) + sizeof(struct udphdr);
2465 	if (!pskb_may_pull(skb, hdr_size))
2466 		return true;
2467 
2468 	amtmu = (struct amt_header_membership_update *)(udp_hdr(skb) + 1);
2469 	if (amtmu->reserved || amtmu->version)
2470 		return true;
2471 
2472 	if (iptunnel_pull_header(skb, hdr_size, skb->protocol, false))
2473 		return true;
2474 
2475 	skb_reset_network_header(skb);
2476 
2477 	list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list) {
2478 		if (tunnel->ip4 == iph->saddr) {
2479 			if ((amtmu->nonce == tunnel->nonce &&
2480 			     amtmu->response_mac == tunnel->mac)) {
2481 				mod_delayed_work(amt_wq, &tunnel->gc_wq,
2482 						 msecs_to_jiffies(amt_gmi(amt))
2483 								  * 3);
2484 				goto report;
2485 			} else {
2486 				netdev_dbg(amt->dev, "Invalid MAC\n");
2487 				return true;
2488 			}
2489 		}
2490 	}
2491 
2492 	return true;
2493 
2494 report:
2495 	if (!pskb_may_pull(skb, sizeof(*iph)))
2496 		return true;
2497 
2498 	iph = ip_hdr(skb);
2499 	if (iph->version == 4) {
2500 		if (ip_mc_check_igmp(skb)) {
2501 			netdev_dbg(amt->dev, "Invalid IGMP\n");
2502 			return true;
2503 		}
2504 
2505 		spin_lock_bh(&tunnel->lock);
2506 		amt_igmp_report_handler(amt, skb, tunnel);
2507 		spin_unlock_bh(&tunnel->lock);
2508 
2509 		skb_push(skb, sizeof(struct ethhdr));
2510 		skb_reset_mac_header(skb);
2511 		eth = eth_hdr(skb);
2512 		skb->protocol = htons(ETH_P_IP);
2513 		eth->h_proto = htons(ETH_P_IP);
2514 		ip_eth_mc_map(iph->daddr, eth->h_dest);
2515 #if IS_ENABLED(CONFIG_IPV6)
2516 	} else if (iph->version == 6) {
2517 		struct ipv6hdr *ip6h = ipv6_hdr(skb);
2518 
2519 		if (ipv6_mc_check_mld(skb)) {
2520 			netdev_dbg(amt->dev, "Invalid MLD\n");
2521 			return true;
2522 		}
2523 
2524 		spin_lock_bh(&tunnel->lock);
2525 		amt_mld_report_handler(amt, skb, tunnel);
2526 		spin_unlock_bh(&tunnel->lock);
2527 
2528 		skb_push(skb, sizeof(struct ethhdr));
2529 		skb_reset_mac_header(skb);
2530 		eth = eth_hdr(skb);
2531 		skb->protocol = htons(ETH_P_IPV6);
2532 		eth->h_proto = htons(ETH_P_IPV6);
2533 		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2534 #endif
2535 	} else {
2536 		netdev_dbg(amt->dev, "Unsupported Protocol\n");
2537 		return true;
2538 	}
2539 
2540 	skb_pull(skb, sizeof(struct ethhdr));
2541 	skb->pkt_type = PACKET_MULTICAST;
2542 	skb->ip_summed = CHECKSUM_NONE;
2543 	len = skb->len;
2544 	if (__netif_rx(skb) == NET_RX_SUCCESS) {
2545 		amt_update_relay_status(tunnel, AMT_STATUS_RECEIVED_UPDATE,
2546 					true);
2547 		dev_sw_netstats_rx_add(amt->dev, len);
2548 	} else {
2549 		amt->dev->stats.rx_dropped++;
2550 	}
2551 
2552 	return false;
2553 }
2554 
2555 static void amt_send_advertisement(struct amt_dev *amt, __be32 nonce,
2556 				   __be32 daddr, __be16 dport)
2557 {
2558 	struct amt_header_advertisement *amta;
2559 	int hlen, tlen, offset;
2560 	struct udphdr *udph;
2561 	struct sk_buff *skb;
2562 	struct iphdr *iph;
2563 	struct rtable *rt;
2564 	struct flowi4 fl4;
2565 	struct sock *sk;
2566 	u32 len;
2567 	int err;
2568 
2569 	rcu_read_lock();
2570 	sk = rcu_dereference(amt->sk);
2571 	if (!sk)
2572 		goto out;
2573 
2574 	if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
2575 		goto out;
2576 
2577 	rt = ip_route_output_ports(amt->net, &fl4, sk,
2578 				   daddr, amt->local_ip,
2579 				   dport, amt->relay_port,
2580 				   IPPROTO_UDP, 0,
2581 				   amt->stream_dev->ifindex);
2582 	if (IS_ERR(rt)) {
2583 		amt->dev->stats.tx_errors++;
2584 		goto out;
2585 	}
2586 
2587 	hlen = LL_RESERVED_SPACE(amt->dev);
2588 	tlen = amt->dev->needed_tailroom;
2589 	len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amta);
2590 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
2591 	if (!skb) {
2592 		ip_rt_put(rt);
2593 		amt->dev->stats.tx_errors++;
2594 		goto out;
2595 	}
2596 
2597 	skb->priority = TC_PRIO_CONTROL;
2598 	skb_dst_set(skb, &rt->dst);
2599 
2600 	len = sizeof(*iph) + sizeof(*udph) + sizeof(*amta);
2601 	skb_reset_network_header(skb);
2602 	skb_put(skb, len);
2603 	amta = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
2604 	amta->version	= 0;
2605 	amta->type	= AMT_MSG_ADVERTISEMENT;
2606 	amta->reserved	= 0;
2607 	amta->nonce	= nonce;
2608 	amta->ip4	= amt->local_ip;
2609 	skb_push(skb, sizeof(*udph));
2610 	skb_reset_transport_header(skb);
2611 	udph		= udp_hdr(skb);
2612 	udph->source	= amt->relay_port;
2613 	udph->dest	= dport;
2614 	udph->len	= htons(sizeof(*amta) + sizeof(*udph));
2615 	udph->check	= 0;
2616 	offset = skb_transport_offset(skb);
2617 	skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
2618 	udph->check = csum_tcpudp_magic(amt->local_ip, daddr,
2619 					sizeof(*udph) + sizeof(*amta),
2620 					IPPROTO_UDP, skb->csum);
2621 
2622 	skb_push(skb, sizeof(*iph));
2623 	iph		= ip_hdr(skb);
2624 	iph->version	= 4;
2625 	iph->ihl	= (sizeof(struct iphdr)) >> 2;
2626 	iph->tos	= AMT_TOS;
2627 	iph->frag_off	= 0;
2628 	iph->ttl	= ip4_dst_hoplimit(&rt->dst);
2629 	iph->daddr	= daddr;
2630 	iph->saddr	= amt->local_ip;
2631 	iph->protocol	= IPPROTO_UDP;
2632 	iph->tot_len	= htons(len);
2633 
2634 	skb->ip_summed = CHECKSUM_NONE;
2635 	ip_select_ident(amt->net, skb, NULL);
2636 	ip_send_check(iph);
2637 	err = ip_local_out(amt->net, sk, skb);
2638 	if (unlikely(net_xmit_eval(err)))
2639 		amt->dev->stats.tx_errors++;
2640 
2641 out:
2642 	rcu_read_unlock();
2643 }
2644 
2645 static bool amt_discovery_handler(struct amt_dev *amt, struct sk_buff *skb)
2646 {
2647 	struct amt_header_discovery *amtd;
2648 	struct udphdr *udph;
2649 	struct iphdr *iph;
2650 
2651 	if (!pskb_may_pull(skb, sizeof(*udph) + sizeof(*amtd)))
2652 		return true;
2653 
2654 	iph = ip_hdr(skb);
2655 	udph = udp_hdr(skb);
2656 	amtd = (struct amt_header_discovery *)(udp_hdr(skb) + 1);
2657 
2658 	if (amtd->reserved || amtd->version)
2659 		return true;
2660 
2661 	amt_send_advertisement(amt, amtd->nonce, iph->saddr, udph->source);
2662 
2663 	return false;
2664 }
2665 
2666 static bool amt_request_handler(struct amt_dev *amt, struct sk_buff *skb)
2667 {
2668 	struct amt_header_request *amtrh;
2669 	struct amt_tunnel_list *tunnel;
2670 	unsigned long long key;
2671 	struct udphdr *udph;
2672 	struct iphdr *iph;
2673 	u64 mac;
2674 	int i;
2675 
2676 	if (!pskb_may_pull(skb, sizeof(*udph) + sizeof(*amtrh)))
2677 		return true;
2678 
2679 	iph = ip_hdr(skb);
2680 	udph = udp_hdr(skb);
2681 	amtrh = (struct amt_header_request *)(udp_hdr(skb) + 1);
2682 
2683 	if (amtrh->reserved1 || amtrh->reserved2 || amtrh->version)
2684 		return true;
2685 
2686 	list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list)
2687 		if (tunnel->ip4 == iph->saddr)
2688 			goto send;
2689 
2690 	spin_lock_bh(&amt->lock);
2691 	if (amt->nr_tunnels >= amt->max_tunnels) {
2692 		spin_unlock_bh(&amt->lock);
2693 		icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
2694 		return true;
2695 	}
2696 
2697 	tunnel = kzalloc(sizeof(*tunnel) +
2698 			 (sizeof(struct hlist_head) * amt->hash_buckets),
2699 			 GFP_ATOMIC);
2700 	if (!tunnel) {
2701 		spin_unlock_bh(&amt->lock);
2702 		return true;
2703 	}
2704 
2705 	tunnel->source_port = udph->source;
2706 	tunnel->ip4 = iph->saddr;
2707 
2708 	memcpy(&key, &tunnel->key, sizeof(unsigned long long));
2709 	tunnel->amt = amt;
2710 	spin_lock_init(&tunnel->lock);
2711 	for (i = 0; i < amt->hash_buckets; i++)
2712 		INIT_HLIST_HEAD(&tunnel->groups[i]);
2713 
2714 	INIT_DELAYED_WORK(&tunnel->gc_wq, amt_tunnel_expire);
2715 
2716 	list_add_tail_rcu(&tunnel->list, &amt->tunnel_list);
2717 	tunnel->key = amt->key;
2718 	__amt_update_relay_status(tunnel, AMT_STATUS_RECEIVED_REQUEST, true);
2719 	amt->nr_tunnels++;
2720 	mod_delayed_work(amt_wq, &tunnel->gc_wq,
2721 			 msecs_to_jiffies(amt_gmi(amt)));
2722 	spin_unlock_bh(&amt->lock);
2723 
2724 send:
2725 	tunnel->nonce = amtrh->nonce;
2726 	mac = siphash_3u32((__force u32)tunnel->ip4,
2727 			   (__force u32)tunnel->source_port,
2728 			   (__force u32)tunnel->nonce,
2729 			   &tunnel->key);
2730 	tunnel->mac = mac >> 16;
2731 
2732 	if (!netif_running(amt->dev) || !netif_running(amt->stream_dev))
2733 		return true;
2734 
2735 	if (!amtrh->p)
2736 		amt_send_igmp_gq(amt, tunnel);
2737 	else
2738 		amt_send_mld_gq(amt, tunnel);
2739 
2740 	return false;
2741 }
2742 
2743 static void amt_gw_rcv(struct amt_dev *amt, struct sk_buff *skb)
2744 {
2745 	int type = amt_parse_type(skb);
2746 	int err = 1;
2747 
2748 	if (type == -1)
2749 		goto drop;
2750 
2751 	if (amt->mode == AMT_MODE_GATEWAY) {
2752 		switch (type) {
2753 		case AMT_MSG_ADVERTISEMENT:
2754 			err = amt_advertisement_handler(amt, skb);
2755 			break;
2756 		case AMT_MSG_MEMBERSHIP_QUERY:
2757 			err = amt_membership_query_handler(amt, skb);
2758 			if (!err)
2759 				return;
2760 			break;
2761 		default:
2762 			netdev_dbg(amt->dev, "Invalid type of Gateway\n");
2763 			break;
2764 		}
2765 	}
2766 drop:
2767 	if (err) {
2768 		amt->dev->stats.rx_dropped++;
2769 		kfree_skb(skb);
2770 	} else {
2771 		consume_skb(skb);
2772 	}
2773 }
2774 
2775 static int amt_rcv(struct sock *sk, struct sk_buff *skb)
2776 {
2777 	struct amt_dev *amt;
2778 	struct iphdr *iph;
2779 	__be32 remote_ip;
2780 	int type;
2781 	bool err;
2782 
2783 	rcu_read_lock_bh();
2784 	amt = rcu_dereference_sk_user_data(sk);
2785 	if (!amt) {
2786 		err = true;
2787 		kfree_skb(skb);
2788 		goto out;
2789 	}
2790 	remote_ip = READ_ONCE(amt->remote_ip);
2791 
2792 	skb->dev = amt->dev;
2793 	iph = ip_hdr(skb);
2794 	type = amt_parse_type(skb);
2795 	if (type == -1) {
2796 		err = true;
2797 		goto drop;
2798 	}
2799 
2800 	if (amt->mode == AMT_MODE_GATEWAY) {
2801 		switch (type) {
2802 		case AMT_MSG_ADVERTISEMENT:
2803 			if (iph->saddr != amt->discovery_ip) {
2804 				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2805 				err = true;
2806 				goto drop;
2807 			}
2808 			if (amt_queue_event(amt, AMT_EVENT_RECEIVE, skb)) {
2809 				netdev_dbg(amt->dev, "AMT Event queue full\n");
2810 				err = true;
2811 				goto drop;
2812 			}
2813 			goto out;
2814 		case AMT_MSG_MULTICAST_DATA:
2815 			if (iph->saddr != remote_ip) {
2816 				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2817 				err = true;
2818 				goto drop;
2819 			}
2820 			err = amt_multicast_data_handler(amt, skb);
2821 			if (err)
2822 				goto drop;
2823 			else
2824 				goto out;
2825 		case AMT_MSG_MEMBERSHIP_QUERY:
2826 			if (iph->saddr != remote_ip) {
2827 				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2828 				err = true;
2829 				goto drop;
2830 			}
2831 			if (amt_queue_event(amt, AMT_EVENT_RECEIVE, skb)) {
2832 				netdev_dbg(amt->dev, "AMT Event queue full\n");
2833 				err = true;
2834 				goto drop;
2835 			}
2836 			goto out;
2837 		default:
2838 			err = true;
2839 			netdev_dbg(amt->dev, "Invalid type of Gateway\n");
2840 			break;
2841 		}
2842 	} else {
2843 		switch (type) {
2844 		case AMT_MSG_DISCOVERY:
2845 			err = amt_discovery_handler(amt, skb);
2846 			break;
2847 		case AMT_MSG_REQUEST:
2848 			err = amt_request_handler(amt, skb);
2849 			break;
2850 		case AMT_MSG_MEMBERSHIP_UPDATE:
2851 			err = amt_update_handler(amt, skb);
2852 			if (err)
2853 				goto drop;
2854 			else
2855 				goto out;
2856 		default:
2857 			err = true;
2858 			netdev_dbg(amt->dev, "Invalid type of relay\n");
2859 			break;
2860 		}
2861 	}
2862 drop:
2863 	if (err) {
2864 		amt->dev->stats.rx_dropped++;
2865 		kfree_skb(skb);
2866 	} else {
2867 		consume_skb(skb);
2868 	}
2869 out:
2870 	rcu_read_unlock_bh();
2871 	return 0;
2872 }
2873 
2874 static void amt_event_work(struct work_struct *work)
2875 {
2876 	struct amt_dev *amt = container_of(work, struct amt_dev, event_wq);
2877 	struct sk_buff *skb;
2878 	u8 event;
2879 	int i;
2880 
2881 	for (i = 0; i < AMT_MAX_EVENTS; i++) {
2882 		spin_lock_bh(&amt->lock);
2883 		if (amt->nr_events == 0) {
2884 			spin_unlock_bh(&amt->lock);
2885 			return;
2886 		}
2887 		event = amt->events[amt->event_idx].event;
2888 		skb = amt->events[amt->event_idx].skb;
2889 		amt->events[amt->event_idx].event = AMT_EVENT_NONE;
2890 		amt->events[amt->event_idx].skb = NULL;
2891 		amt->nr_events--;
2892 		amt->event_idx++;
2893 		amt->event_idx %= AMT_MAX_EVENTS;
2894 		spin_unlock_bh(&amt->lock);
2895 
2896 		switch (event) {
2897 		case AMT_EVENT_RECEIVE:
2898 			amt_gw_rcv(amt, skb);
2899 			break;
2900 		case AMT_EVENT_SEND_DISCOVERY:
2901 			amt_event_send_discovery(amt);
2902 			break;
2903 		case AMT_EVENT_SEND_REQUEST:
2904 			amt_event_send_request(amt);
2905 			break;
2906 		default:
2907 			kfree_skb(skb);
2908 			break;
2909 		}
2910 	}
2911 }
2912 
2913 static int amt_err_lookup(struct sock *sk, struct sk_buff *skb)
2914 {
2915 	struct amt_dev *amt;
2916 	int type;
2917 
2918 	rcu_read_lock_bh();
2919 	amt = rcu_dereference_sk_user_data(sk);
2920 	if (!amt)
2921 		goto out;
2922 
2923 	if (amt->mode != AMT_MODE_GATEWAY)
2924 		goto drop;
2925 
2926 	type = amt_parse_type(skb);
2927 	if (type == -1)
2928 		goto drop;
2929 
2930 	netdev_dbg(amt->dev, "Received IGMP Unreachable of %s\n",
2931 		   type_str[type]);
2932 	switch (type) {
2933 	case AMT_MSG_DISCOVERY:
2934 		break;
2935 	case AMT_MSG_REQUEST:
2936 	case AMT_MSG_MEMBERSHIP_UPDATE:
2937 		if (READ_ONCE(amt->status) >= AMT_STATUS_RECEIVED_ADVERTISEMENT)
2938 			mod_delayed_work(amt_wq, &amt->req_wq, 0);
2939 		break;
2940 	default:
2941 		goto drop;
2942 	}
2943 out:
2944 	rcu_read_unlock_bh();
2945 	return 0;
2946 drop:
2947 	rcu_read_unlock_bh();
2948 	amt->dev->stats.rx_dropped++;
2949 	return 0;
2950 }
2951 
2952 static struct sock *amt_create_sock(struct net *net, __be16 port)
2953 {
2954 	struct udp_port_cfg udp_conf;
2955 	struct socket *sock;
2956 	int err;
2957 
2958 	memset(&udp_conf, 0, sizeof(udp_conf));
2959 	udp_conf.family = AF_INET;
2960 	udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
2961 
2962 	udp_conf.local_udp_port = port;
2963 
2964 	err = udp_sock_create(net, &udp_conf, &sock);
2965 	if (err < 0)
2966 		return ERR_PTR(err);
2967 
2968 	return sock->sk;
2969 }
2970 
2971 static int amt_socket_create(struct amt_dev *amt)
2972 {
2973 	struct udp_tunnel_sock_cfg tunnel_cfg;
2974 	struct sock *sk;
2975 
2976 	sk = amt_create_sock(amt->net, amt->relay_port);
2977 	if (IS_ERR(sk))
2978 		return PTR_ERR(sk);
2979 
2980 	/* Mark socket as an encapsulation socket */
2981 	memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
2982 	tunnel_cfg.sk_user_data = amt;
2983 	tunnel_cfg.encap_type = 1;
2984 	tunnel_cfg.encap_rcv = amt_rcv;
2985 	tunnel_cfg.encap_err_lookup = amt_err_lookup;
2986 	tunnel_cfg.encap_destroy = NULL;
2987 	setup_udp_tunnel_sock(amt->net, sk, &tunnel_cfg);
2988 
2989 	rcu_assign_pointer(amt->sk, sk);
2990 	return 0;
2991 }
2992 
2993 static int amt_dev_open(struct net_device *dev)
2994 {
2995 	struct amt_dev *amt = netdev_priv(dev);
2996 	int err;
2997 
2998 	amt->ready4 = false;
2999 	amt->ready6 = false;
3000 	amt->event_idx = 0;
3001 	amt->nr_events = 0;
3002 
3003 	err = amt_socket_create(amt);
3004 	if (err)
3005 		return err;
3006 
3007 	amt->req_cnt = 0;
3008 	WRITE_ONCE(amt->remote_ip, 0);
3009 	amt->nonce = 0;
3010 	get_random_bytes(&amt->key, sizeof(siphash_key_t));
3011 
3012 	amt->status = AMT_STATUS_INIT;
3013 	if (amt->mode == AMT_MODE_GATEWAY) {
3014 		mod_delayed_work(amt_wq, &amt->discovery_wq, 0);
3015 		mod_delayed_work(amt_wq, &amt->req_wq, 0);
3016 	} else if (amt->mode == AMT_MODE_RELAY) {
3017 		mod_delayed_work(amt_wq, &amt->secret_wq,
3018 				 msecs_to_jiffies(AMT_SECRET_TIMEOUT));
3019 	}
3020 	return err;
3021 }
3022 
3023 static int amt_dev_stop(struct net_device *dev)
3024 {
3025 	struct amt_dev *amt = netdev_priv(dev);
3026 	struct amt_tunnel_list *tunnel, *tmp;
3027 	struct sk_buff *skb;
3028 	struct sock *sk;
3029 	int i;
3030 
3031 	cancel_delayed_work_sync(&amt->req_wq);
3032 	cancel_delayed_work_sync(&amt->discovery_wq);
3033 	cancel_delayed_work_sync(&amt->secret_wq);
3034 
3035 	/* shutdown */
3036 	sk = rtnl_dereference(amt->sk);
3037 	RCU_INIT_POINTER(amt->sk, NULL);
3038 	synchronize_net();
3039 	if (sk)
3040 		udp_tunnel_sock_release(sk);
3041 
3042 	cancel_work_sync(&amt->event_wq);
3043 	for (i = 0; i < AMT_MAX_EVENTS; i++) {
3044 		skb = amt->events[i].skb;
3045 		kfree_skb(skb);
3046 		amt->events[i].event = AMT_EVENT_NONE;
3047 		amt->events[i].skb = NULL;
3048 	}
3049 
3050 	amt->ready4 = false;
3051 	amt->ready6 = false;
3052 	amt->req_cnt = 0;
3053 	WRITE_ONCE(amt->remote_ip, 0);
3054 
3055 	list_for_each_entry_safe(tunnel, tmp, &amt->tunnel_list, list) {
3056 		list_del_rcu(&tunnel->list);
3057 		amt->nr_tunnels--;
3058 		cancel_delayed_work_sync(&tunnel->gc_wq);
3059 		amt_clear_groups(tunnel);
3060 		kfree_rcu(tunnel, rcu);
3061 	}
3062 
3063 	return 0;
3064 }
3065 
3066 static const struct device_type amt_type = {
3067 	.name = "amt",
3068 };
3069 
3070 static int amt_dev_init(struct net_device *dev)
3071 {
3072 	struct amt_dev *amt = netdev_priv(dev);
3073 	int err;
3074 
3075 	amt->dev = dev;
3076 
3077 	err = gro_cells_init(&amt->gro_cells, dev);
3078 	if (err)
3079 		return err;
3080 
3081 	return 0;
3082 }
3083 
3084 static void amt_dev_uninit(struct net_device *dev)
3085 {
3086 	struct amt_dev *amt = netdev_priv(dev);
3087 
3088 	gro_cells_destroy(&amt->gro_cells);
3089 }
3090 
3091 static const struct net_device_ops amt_netdev_ops = {
3092 	.ndo_init               = amt_dev_init,
3093 	.ndo_uninit             = amt_dev_uninit,
3094 	.ndo_open		= amt_dev_open,
3095 	.ndo_stop		= amt_dev_stop,
3096 	.ndo_start_xmit         = amt_dev_xmit,
3097 };
3098 
3099 static void amt_link_setup(struct net_device *dev)
3100 {
3101 	dev->netdev_ops         = &amt_netdev_ops;
3102 	dev->needs_free_netdev  = true;
3103 	SET_NETDEV_DEVTYPE(dev, &amt_type);
3104 	dev->min_mtu		= ETH_MIN_MTU;
3105 	dev->max_mtu		= ETH_MAX_MTU;
3106 	dev->type		= ARPHRD_NONE;
3107 	dev->flags		= IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
3108 	dev->hard_header_len	= 0;
3109 	dev->addr_len		= 0;
3110 	dev->priv_flags		|= IFF_NO_QUEUE;
3111 	dev->lltx		= true;
3112 	dev->netns_immutable	= true;
3113 	dev->features		|= NETIF_F_GSO_SOFTWARE;
3114 	dev->hw_features	|= NETIF_F_SG | NETIF_F_HW_CSUM;
3115 	dev->hw_features	|= NETIF_F_FRAGLIST | NETIF_F_RXCSUM;
3116 	dev->hw_features	|= NETIF_F_GSO_SOFTWARE;
3117 	dev->pcpu_stat_type	= NETDEV_PCPU_STAT_TSTATS;
3118 	eth_hw_addr_random(dev);
3119 	eth_zero_addr(dev->broadcast);
3120 	ether_setup(dev);
3121 }
3122 
3123 static const struct nla_policy amt_policy[IFLA_AMT_MAX + 1] = {
3124 	[IFLA_AMT_MODE]		= { .type = NLA_U32 },
3125 	[IFLA_AMT_RELAY_PORT]	= { .type = NLA_U16 },
3126 	[IFLA_AMT_GATEWAY_PORT]	= { .type = NLA_U16 },
3127 	[IFLA_AMT_LINK]		= { .type = NLA_U32 },
3128 	[IFLA_AMT_LOCAL_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
3129 	[IFLA_AMT_REMOTE_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
3130 	[IFLA_AMT_DISCOVERY_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
3131 	[IFLA_AMT_MAX_TUNNELS]	= { .type = NLA_U32 },
3132 };
3133 
3134 static int amt_validate(struct nlattr *tb[], struct nlattr *data[],
3135 			struct netlink_ext_ack *extack)
3136 {
3137 	if (!data)
3138 		return -EINVAL;
3139 
3140 	if (!data[IFLA_AMT_LINK]) {
3141 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_LINK],
3142 				    "Link attribute is required");
3143 		return -EINVAL;
3144 	}
3145 
3146 	if (!data[IFLA_AMT_MODE]) {
3147 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_MODE],
3148 				    "Mode attribute is required");
3149 		return -EINVAL;
3150 	}
3151 
3152 	if (nla_get_u32(data[IFLA_AMT_MODE]) > AMT_MODE_MAX) {
3153 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_MODE],
3154 				    "Mode attribute is not valid");
3155 		return -EINVAL;
3156 	}
3157 
3158 	if (!data[IFLA_AMT_LOCAL_IP]) {
3159 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_DISCOVERY_IP],
3160 				    "Local attribute is required");
3161 		return -EINVAL;
3162 	}
3163 
3164 	if (!data[IFLA_AMT_DISCOVERY_IP] &&
3165 	    nla_get_u32(data[IFLA_AMT_MODE]) == AMT_MODE_GATEWAY) {
3166 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_LOCAL_IP],
3167 				    "Discovery attribute is required");
3168 		return -EINVAL;
3169 	}
3170 
3171 	return 0;
3172 }
3173 
3174 static int amt_newlink(struct net_device *dev,
3175 		       struct rtnl_newlink_params *params,
3176 		       struct netlink_ext_ack *extack)
3177 {
3178 	struct net *link_net = rtnl_newlink_link_net(params);
3179 	struct amt_dev *amt = netdev_priv(dev);
3180 	struct nlattr **data = params->data;
3181 	struct nlattr **tb = params->tb;
3182 	int err = -EINVAL;
3183 
3184 	amt->net = link_net;
3185 	amt->mode = nla_get_u32(data[IFLA_AMT_MODE]);
3186 
3187 	if (data[IFLA_AMT_MAX_TUNNELS] &&
3188 	    nla_get_u32(data[IFLA_AMT_MAX_TUNNELS]))
3189 		amt->max_tunnels = nla_get_u32(data[IFLA_AMT_MAX_TUNNELS]);
3190 	else
3191 		amt->max_tunnels = AMT_MAX_TUNNELS;
3192 
3193 	spin_lock_init(&amt->lock);
3194 	amt->max_groups = AMT_MAX_GROUP;
3195 	amt->max_sources = AMT_MAX_SOURCE;
3196 	amt->hash_buckets = AMT_HSIZE;
3197 	amt->nr_tunnels = 0;
3198 	get_random_bytes(&amt->hash_seed, sizeof(amt->hash_seed));
3199 	amt->stream_dev = dev_get_by_index(link_net,
3200 					   nla_get_u32(data[IFLA_AMT_LINK]));
3201 	if (!amt->stream_dev) {
3202 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LINK],
3203 				    "Can't find stream device");
3204 		return -ENODEV;
3205 	}
3206 
3207 	if (amt->stream_dev->type != ARPHRD_ETHER) {
3208 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LINK],
3209 				    "Invalid stream device type");
3210 		goto err;
3211 	}
3212 
3213 	amt->local_ip = nla_get_in_addr(data[IFLA_AMT_LOCAL_IP]);
3214 	if (ipv4_is_loopback(amt->local_ip) ||
3215 	    ipv4_is_zeronet(amt->local_ip) ||
3216 	    ipv4_is_multicast(amt->local_ip)) {
3217 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LOCAL_IP],
3218 				    "Invalid Local address");
3219 		goto err;
3220 	}
3221 
3222 	amt->relay_port = nla_get_be16_default(data[IFLA_AMT_RELAY_PORT],
3223 					       htons(IANA_AMT_UDP_PORT));
3224 
3225 	amt->gw_port = nla_get_be16_default(data[IFLA_AMT_GATEWAY_PORT],
3226 					    htons(IANA_AMT_UDP_PORT));
3227 
3228 	if (!amt->relay_port) {
3229 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3230 				    "relay port must not be 0");
3231 		goto err;
3232 	}
3233 	if (amt->mode == AMT_MODE_RELAY) {
3234 		amt->qrv = READ_ONCE(amt->net->ipv4.sysctl_igmp_qrv);
3235 		amt->qri = 10;
3236 		dev->needed_headroom = amt->stream_dev->needed_headroom +
3237 				       AMT_RELAY_HLEN;
3238 		dev->mtu = amt->stream_dev->mtu - AMT_RELAY_HLEN;
3239 		dev->max_mtu = dev->mtu;
3240 		dev->min_mtu = ETH_MIN_MTU + AMT_RELAY_HLEN;
3241 	} else {
3242 		if (!data[IFLA_AMT_DISCOVERY_IP]) {
3243 			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3244 					    "discovery must be set in gateway mode");
3245 			goto err;
3246 		}
3247 		if (!amt->gw_port) {
3248 			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3249 					    "gateway port must not be 0");
3250 			goto err;
3251 		}
3252 		WRITE_ONCE(amt->remote_ip, 0);
3253 		amt->discovery_ip = nla_get_in_addr(data[IFLA_AMT_DISCOVERY_IP]);
3254 		if (ipv4_is_loopback(amt->discovery_ip) ||
3255 		    ipv4_is_zeronet(amt->discovery_ip) ||
3256 		    ipv4_is_multicast(amt->discovery_ip)) {
3257 			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3258 					    "discovery must be unicast");
3259 			goto err;
3260 		}
3261 
3262 		dev->needed_headroom = amt->stream_dev->needed_headroom +
3263 				       AMT_GW_HLEN;
3264 		dev->mtu = amt->stream_dev->mtu - AMT_GW_HLEN;
3265 		dev->max_mtu = dev->mtu;
3266 		dev->min_mtu = ETH_MIN_MTU + AMT_GW_HLEN;
3267 	}
3268 	amt->qi = AMT_INIT_QUERY_INTERVAL;
3269 
3270 	err = register_netdevice(dev);
3271 	if (err < 0) {
3272 		netdev_dbg(dev, "failed to register new netdev %d\n", err);
3273 		goto err;
3274 	}
3275 
3276 	err = netdev_upper_dev_link(amt->stream_dev, dev, extack);
3277 	if (err < 0) {
3278 		unregister_netdevice(dev);
3279 		goto err;
3280 	}
3281 
3282 	INIT_DELAYED_WORK(&amt->discovery_wq, amt_discovery_work);
3283 	INIT_DELAYED_WORK(&amt->req_wq, amt_req_work);
3284 	INIT_DELAYED_WORK(&amt->secret_wq, amt_secret_work);
3285 	INIT_WORK(&amt->event_wq, amt_event_work);
3286 	INIT_LIST_HEAD(&amt->tunnel_list);
3287 	return 0;
3288 err:
3289 	dev_put(amt->stream_dev);
3290 	return err;
3291 }
3292 
3293 static void amt_dellink(struct net_device *dev, struct list_head *head)
3294 {
3295 	struct amt_dev *amt = netdev_priv(dev);
3296 
3297 	unregister_netdevice_queue(dev, head);
3298 	netdev_upper_dev_unlink(amt->stream_dev, dev);
3299 	dev_put(amt->stream_dev);
3300 }
3301 
3302 static size_t amt_get_size(const struct net_device *dev)
3303 {
3304 	return nla_total_size(sizeof(__u32)) + /* IFLA_AMT_MODE */
3305 	       nla_total_size(sizeof(__u16)) + /* IFLA_AMT_RELAY_PORT */
3306 	       nla_total_size(sizeof(__u16)) + /* IFLA_AMT_GATEWAY_PORT */
3307 	       nla_total_size(sizeof(__u32)) + /* IFLA_AMT_LINK */
3308 	       nla_total_size(sizeof(__u32)) + /* IFLA_MAX_TUNNELS */
3309 	       nla_total_size(sizeof(__be32)) + /* IFLA_AMT_DISCOVERY_IP */
3310 	       nla_total_size(sizeof(__be32)) + /* IFLA_AMT_REMOTE_IP */
3311 	       nla_total_size(sizeof(__be32)); /* IFLA_AMT_LOCAL_IP */
3312 }
3313 
3314 static int amt_fill_info(struct sk_buff *skb, const struct net_device *dev)
3315 {
3316 	const struct amt_dev *amt = netdev_priv(dev);
3317 	__be32 remote_ip;
3318 
3319 	rcu_read_lock();
3320 	if (nla_put_u32(skb, IFLA_AMT_MODE, amt->mode))
3321 		goto nla_put_failure;
3322 	if (nla_put_be16(skb, IFLA_AMT_RELAY_PORT, amt->relay_port))
3323 		goto nla_put_failure;
3324 	if (nla_put_be16(skb, IFLA_AMT_GATEWAY_PORT, amt->gw_port))
3325 		goto nla_put_failure;
3326 	if (nla_put_u32(skb, IFLA_AMT_LINK, amt->stream_dev->ifindex))
3327 		goto nla_put_failure;
3328 	if (nla_put_in_addr(skb, IFLA_AMT_LOCAL_IP, amt->local_ip))
3329 		goto nla_put_failure;
3330 	if (nla_put_in_addr(skb, IFLA_AMT_DISCOVERY_IP, amt->discovery_ip))
3331 		goto nla_put_failure;
3332 
3333 	remote_ip = READ_ONCE(amt->remote_ip);
3334 	if (remote_ip)
3335 		if (nla_put_in_addr(skb, IFLA_AMT_REMOTE_IP, remote_ip))
3336 			goto nla_put_failure;
3337 	if (nla_put_u32(skb, IFLA_AMT_MAX_TUNNELS, amt->max_tunnels))
3338 		goto nla_put_failure;
3339 
3340 	rcu_read_unlock();
3341 	return 0;
3342 
3343 nla_put_failure:
3344 	rcu_read_unlock();
3345 	return -EMSGSIZE;
3346 }
3347 
3348 static struct rtnl_link_ops amt_link_ops __read_mostly = {
3349 	.kind		= "amt",
3350 	.maxtype	= IFLA_AMT_MAX,
3351 	.policy		= amt_policy,
3352 	.priv_size	= sizeof(struct amt_dev),
3353 	.setup		= amt_link_setup,
3354 	.validate	= amt_validate,
3355 	.newlink	= amt_newlink,
3356 	.dellink	= amt_dellink,
3357 	.get_size       = amt_get_size,
3358 	.fill_info      = amt_fill_info,
3359 };
3360 
3361 static struct net_device *amt_lookup_upper_dev(struct net_device *dev)
3362 {
3363 	struct net_device *upper_dev;
3364 	struct amt_dev *amt;
3365 
3366 	for_each_netdev(dev_net(dev), upper_dev) {
3367 		if (netif_is_amt(upper_dev)) {
3368 			amt = netdev_priv(upper_dev);
3369 			if (amt->stream_dev == dev)
3370 				return upper_dev;
3371 		}
3372 	}
3373 
3374 	return NULL;
3375 }
3376 
3377 static int amt_device_event(struct notifier_block *unused,
3378 			    unsigned long event, void *ptr)
3379 {
3380 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3381 	struct net_device *upper_dev;
3382 	struct amt_dev *amt;
3383 	LIST_HEAD(list);
3384 	int new_mtu;
3385 
3386 	upper_dev = amt_lookup_upper_dev(dev);
3387 	if (!upper_dev)
3388 		return NOTIFY_DONE;
3389 	amt = netdev_priv(upper_dev);
3390 
3391 	switch (event) {
3392 	case NETDEV_UNREGISTER:
3393 		amt_dellink(amt->dev, &list);
3394 		unregister_netdevice_many(&list);
3395 		break;
3396 	case NETDEV_CHANGEMTU:
3397 		if (amt->mode == AMT_MODE_RELAY)
3398 			new_mtu = dev->mtu - AMT_RELAY_HLEN;
3399 		else
3400 			new_mtu = dev->mtu - AMT_GW_HLEN;
3401 
3402 		dev_set_mtu(amt->dev, new_mtu);
3403 		break;
3404 	}
3405 
3406 	return NOTIFY_DONE;
3407 }
3408 
3409 static struct notifier_block amt_notifier_block __read_mostly = {
3410 	.notifier_call = amt_device_event,
3411 };
3412 
3413 static int __init amt_init(void)
3414 {
3415 	int err;
3416 
3417 	err = register_netdevice_notifier(&amt_notifier_block);
3418 	if (err < 0)
3419 		goto err;
3420 
3421 	err = rtnl_link_register(&amt_link_ops);
3422 	if (err < 0)
3423 		goto unregister_notifier;
3424 
3425 	amt_wq = alloc_workqueue("amt", WQ_UNBOUND, 0);
3426 	if (!amt_wq) {
3427 		err = -ENOMEM;
3428 		goto rtnl_unregister;
3429 	}
3430 
3431 	spin_lock_init(&source_gc_lock);
3432 	spin_lock_bh(&source_gc_lock);
3433 	INIT_DELAYED_WORK(&source_gc_wq, amt_source_gc_work);
3434 	mod_delayed_work(amt_wq, &source_gc_wq,
3435 			 msecs_to_jiffies(AMT_GC_INTERVAL));
3436 	spin_unlock_bh(&source_gc_lock);
3437 
3438 	return 0;
3439 
3440 rtnl_unregister:
3441 	rtnl_link_unregister(&amt_link_ops);
3442 unregister_notifier:
3443 	unregister_netdevice_notifier(&amt_notifier_block);
3444 err:
3445 	pr_err("error loading AMT module loaded\n");
3446 	return err;
3447 }
3448 late_initcall(amt_init);
3449 
3450 static void __exit amt_fini(void)
3451 {
3452 	rtnl_link_unregister(&amt_link_ops);
3453 	unregister_netdevice_notifier(&amt_notifier_block);
3454 	cancel_delayed_work_sync(&source_gc_wq);
3455 	__amt_source_gc_work();
3456 	destroy_workqueue(amt_wq);
3457 }
3458 module_exit(amt_fini);
3459 
3460 MODULE_LICENSE("GPL");
3461 MODULE_DESCRIPTION("Driver for Automatic Multicast Tunneling (AMT)");
3462 MODULE_AUTHOR("Taehee Yoo <ap420073@gmail.com>");
3463 MODULE_ALIAS_RTNL_LINK("amt");
3464