xref: /openbmc/linux/drivers/net/amt.c (revision 53a2a90d)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Copyright (c) 2021 Taehee Yoo <ap420073@gmail.com> */
3 
4 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
5 
6 #include <linux/module.h>
7 #include <linux/skbuff.h>
8 #include <linux/udp.h>
9 #include <linux/jhash.h>
10 #include <linux/if_tunnel.h>
11 #include <linux/net.h>
12 #include <linux/igmp.h>
13 #include <linux/workqueue.h>
14 #include <net/sch_generic.h>
15 #include <net/net_namespace.h>
16 #include <net/ip.h>
17 #include <net/udp.h>
18 #include <net/udp_tunnel.h>
19 #include <net/icmp.h>
20 #include <net/mld.h>
21 #include <net/amt.h>
22 #include <uapi/linux/amt.h>
23 #include <linux/security.h>
24 #include <net/gro_cells.h>
25 #include <net/ipv6.h>
26 #include <net/if_inet6.h>
27 #include <net/ndisc.h>
28 #include <net/addrconf.h>
29 #include <net/ip6_route.h>
30 #include <net/inet_common.h>
31 #include <net/ip6_checksum.h>
32 
33 static struct workqueue_struct *amt_wq;
34 
35 static HLIST_HEAD(source_gc_list);
36 /* Lock for source_gc_list */
37 static spinlock_t source_gc_lock;
38 static struct delayed_work source_gc_wq;
39 static char *status_str[] = {
40 	"AMT_STATUS_INIT",
41 	"AMT_STATUS_SENT_DISCOVERY",
42 	"AMT_STATUS_RECEIVED_DISCOVERY",
43 	"AMT_STATUS_SENT_ADVERTISEMENT",
44 	"AMT_STATUS_RECEIVED_ADVERTISEMENT",
45 	"AMT_STATUS_SENT_REQUEST",
46 	"AMT_STATUS_RECEIVED_REQUEST",
47 	"AMT_STATUS_SENT_QUERY",
48 	"AMT_STATUS_RECEIVED_QUERY",
49 	"AMT_STATUS_SENT_UPDATE",
50 	"AMT_STATUS_RECEIVED_UPDATE",
51 };
52 
53 static char *type_str[] = {
54 	"", /* Type 0 is not defined */
55 	"AMT_MSG_DISCOVERY",
56 	"AMT_MSG_ADVERTISEMENT",
57 	"AMT_MSG_REQUEST",
58 	"AMT_MSG_MEMBERSHIP_QUERY",
59 	"AMT_MSG_MEMBERSHIP_UPDATE",
60 	"AMT_MSG_MULTICAST_DATA",
61 	"AMT_MSG_TEARDOWN",
62 };
63 
64 static char *action_str[] = {
65 	"AMT_ACT_GMI",
66 	"AMT_ACT_GMI_ZERO",
67 	"AMT_ACT_GT",
68 	"AMT_ACT_STATUS_FWD_NEW",
69 	"AMT_ACT_STATUS_D_FWD_NEW",
70 	"AMT_ACT_STATUS_NONE_NEW",
71 };
72 
73 static struct igmpv3_grec igmpv3_zero_grec;
74 
75 #if IS_ENABLED(CONFIG_IPV6)
76 #define MLD2_ALL_NODE_INIT { { { 0xff, 0x02, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x01 } } }
77 static struct in6_addr mld2_all_node = MLD2_ALL_NODE_INIT;
78 static struct mld2_grec mldv2_zero_grec;
79 #endif
80 
81 static struct amt_skb_cb *amt_skb_cb(struct sk_buff *skb)
82 {
83 	BUILD_BUG_ON(sizeof(struct amt_skb_cb) + sizeof(struct qdisc_skb_cb) >
84 		     sizeof_field(struct sk_buff, cb));
85 
86 	return (struct amt_skb_cb *)((void *)skb->cb +
87 		sizeof(struct qdisc_skb_cb));
88 }
89 
90 static void __amt_source_gc_work(void)
91 {
92 	struct amt_source_node *snode;
93 	struct hlist_head gc_list;
94 	struct hlist_node *t;
95 
96 	spin_lock_bh(&source_gc_lock);
97 	hlist_move_list(&source_gc_list, &gc_list);
98 	spin_unlock_bh(&source_gc_lock);
99 
100 	hlist_for_each_entry_safe(snode, t, &gc_list, node) {
101 		hlist_del_rcu(&snode->node);
102 		kfree_rcu(snode, rcu);
103 	}
104 }
105 
106 static void amt_source_gc_work(struct work_struct *work)
107 {
108 	__amt_source_gc_work();
109 
110 	spin_lock_bh(&source_gc_lock);
111 	mod_delayed_work(amt_wq, &source_gc_wq,
112 			 msecs_to_jiffies(AMT_GC_INTERVAL));
113 	spin_unlock_bh(&source_gc_lock);
114 }
115 
116 static bool amt_addr_equal(union amt_addr *a, union amt_addr *b)
117 {
118 	return !memcmp(a, b, sizeof(union amt_addr));
119 }
120 
121 static u32 amt_source_hash(struct amt_tunnel_list *tunnel, union amt_addr *src)
122 {
123 	u32 hash = jhash(src, sizeof(*src), tunnel->amt->hash_seed);
124 
125 	return reciprocal_scale(hash, tunnel->amt->hash_buckets);
126 }
127 
128 static bool amt_status_filter(struct amt_source_node *snode,
129 			      enum amt_filter filter)
130 {
131 	bool rc = false;
132 
133 	switch (filter) {
134 	case AMT_FILTER_FWD:
135 		if (snode->status == AMT_SOURCE_STATUS_FWD &&
136 		    snode->flags == AMT_SOURCE_OLD)
137 			rc = true;
138 		break;
139 	case AMT_FILTER_D_FWD:
140 		if (snode->status == AMT_SOURCE_STATUS_D_FWD &&
141 		    snode->flags == AMT_SOURCE_OLD)
142 			rc = true;
143 		break;
144 	case AMT_FILTER_FWD_NEW:
145 		if (snode->status == AMT_SOURCE_STATUS_FWD &&
146 		    snode->flags == AMT_SOURCE_NEW)
147 			rc = true;
148 		break;
149 	case AMT_FILTER_D_FWD_NEW:
150 		if (snode->status == AMT_SOURCE_STATUS_D_FWD &&
151 		    snode->flags == AMT_SOURCE_NEW)
152 			rc = true;
153 		break;
154 	case AMT_FILTER_ALL:
155 		rc = true;
156 		break;
157 	case AMT_FILTER_NONE_NEW:
158 		if (snode->status == AMT_SOURCE_STATUS_NONE &&
159 		    snode->flags == AMT_SOURCE_NEW)
160 			rc = true;
161 		break;
162 	case AMT_FILTER_BOTH:
163 		if ((snode->status == AMT_SOURCE_STATUS_D_FWD ||
164 		     snode->status == AMT_SOURCE_STATUS_FWD) &&
165 		    snode->flags == AMT_SOURCE_OLD)
166 			rc = true;
167 		break;
168 	case AMT_FILTER_BOTH_NEW:
169 		if ((snode->status == AMT_SOURCE_STATUS_D_FWD ||
170 		     snode->status == AMT_SOURCE_STATUS_FWD) &&
171 		    snode->flags == AMT_SOURCE_NEW)
172 			rc = true;
173 		break;
174 	default:
175 		WARN_ON_ONCE(1);
176 		break;
177 	}
178 
179 	return rc;
180 }
181 
182 static struct amt_source_node *amt_lookup_src(struct amt_tunnel_list *tunnel,
183 					      struct amt_group_node *gnode,
184 					      enum amt_filter filter,
185 					      union amt_addr *src)
186 {
187 	u32 hash = amt_source_hash(tunnel, src);
188 	struct amt_source_node *snode;
189 
190 	hlist_for_each_entry_rcu(snode, &gnode->sources[hash], node)
191 		if (amt_status_filter(snode, filter) &&
192 		    amt_addr_equal(&snode->source_addr, src))
193 			return snode;
194 
195 	return NULL;
196 }
197 
198 static u32 amt_group_hash(struct amt_tunnel_list *tunnel, union amt_addr *group)
199 {
200 	u32 hash = jhash(group, sizeof(*group), tunnel->amt->hash_seed);
201 
202 	return reciprocal_scale(hash, tunnel->amt->hash_buckets);
203 }
204 
205 static struct amt_group_node *amt_lookup_group(struct amt_tunnel_list *tunnel,
206 					       union amt_addr *group,
207 					       union amt_addr *host,
208 					       bool v6)
209 {
210 	u32 hash = amt_group_hash(tunnel, group);
211 	struct amt_group_node *gnode;
212 
213 	hlist_for_each_entry_rcu(gnode, &tunnel->groups[hash], node) {
214 		if (amt_addr_equal(&gnode->group_addr, group) &&
215 		    amt_addr_equal(&gnode->host_addr, host) &&
216 		    gnode->v6 == v6)
217 			return gnode;
218 	}
219 
220 	return NULL;
221 }
222 
223 static void amt_destroy_source(struct amt_source_node *snode)
224 {
225 	struct amt_group_node *gnode = snode->gnode;
226 	struct amt_tunnel_list *tunnel;
227 
228 	tunnel = gnode->tunnel_list;
229 
230 	if (!gnode->v6) {
231 		netdev_dbg(snode->gnode->amt->dev,
232 			   "Delete source %pI4 from %pI4\n",
233 			   &snode->source_addr.ip4,
234 			   &gnode->group_addr.ip4);
235 #if IS_ENABLED(CONFIG_IPV6)
236 	} else {
237 		netdev_dbg(snode->gnode->amt->dev,
238 			   "Delete source %pI6 from %pI6\n",
239 			   &snode->source_addr.ip6,
240 			   &gnode->group_addr.ip6);
241 #endif
242 	}
243 
244 	cancel_delayed_work(&snode->source_timer);
245 	hlist_del_init_rcu(&snode->node);
246 	tunnel->nr_sources--;
247 	gnode->nr_sources--;
248 	spin_lock_bh(&source_gc_lock);
249 	hlist_add_head_rcu(&snode->node, &source_gc_list);
250 	spin_unlock_bh(&source_gc_lock);
251 }
252 
253 static void amt_del_group(struct amt_dev *amt, struct amt_group_node *gnode)
254 {
255 	struct amt_source_node *snode;
256 	struct hlist_node *t;
257 	int i;
258 
259 	if (cancel_delayed_work(&gnode->group_timer))
260 		dev_put(amt->dev);
261 	hlist_del_rcu(&gnode->node);
262 	gnode->tunnel_list->nr_groups--;
263 
264 	if (!gnode->v6)
265 		netdev_dbg(amt->dev, "Leave group %pI4\n",
266 			   &gnode->group_addr.ip4);
267 #if IS_ENABLED(CONFIG_IPV6)
268 	else
269 		netdev_dbg(amt->dev, "Leave group %pI6\n",
270 			   &gnode->group_addr.ip6);
271 #endif
272 	for (i = 0; i < amt->hash_buckets; i++)
273 		hlist_for_each_entry_safe(snode, t, &gnode->sources[i], node)
274 			amt_destroy_source(snode);
275 
276 	/* tunnel->lock was acquired outside of amt_del_group()
277 	 * But rcu_read_lock() was acquired too so It's safe.
278 	 */
279 	kfree_rcu(gnode, rcu);
280 }
281 
282 /* If a source timer expires with a router filter-mode for the group of
283  * INCLUDE, the router concludes that traffic from this particular
284  * source is no longer desired on the attached network, and deletes the
285  * associated source record.
286  */
287 static void amt_source_work(struct work_struct *work)
288 {
289 	struct amt_source_node *snode = container_of(to_delayed_work(work),
290 						     struct amt_source_node,
291 						     source_timer);
292 	struct amt_group_node *gnode = snode->gnode;
293 	struct amt_dev *amt = gnode->amt;
294 	struct amt_tunnel_list *tunnel;
295 
296 	tunnel = gnode->tunnel_list;
297 	spin_lock_bh(&tunnel->lock);
298 	rcu_read_lock();
299 	if (gnode->filter_mode == MCAST_INCLUDE) {
300 		amt_destroy_source(snode);
301 		if (!gnode->nr_sources)
302 			amt_del_group(amt, gnode);
303 	} else {
304 		/* When a router filter-mode for a group is EXCLUDE,
305 		 * source records are only deleted when the group timer expires
306 		 */
307 		snode->status = AMT_SOURCE_STATUS_D_FWD;
308 	}
309 	rcu_read_unlock();
310 	spin_unlock_bh(&tunnel->lock);
311 }
312 
313 static void amt_act_src(struct amt_tunnel_list *tunnel,
314 			struct amt_group_node *gnode,
315 			struct amt_source_node *snode,
316 			enum amt_act act)
317 {
318 	struct amt_dev *amt = tunnel->amt;
319 
320 	switch (act) {
321 	case AMT_ACT_GMI:
322 		mod_delayed_work(amt_wq, &snode->source_timer,
323 				 msecs_to_jiffies(amt_gmi(amt)));
324 		break;
325 	case AMT_ACT_GMI_ZERO:
326 		cancel_delayed_work(&snode->source_timer);
327 		break;
328 	case AMT_ACT_GT:
329 		mod_delayed_work(amt_wq, &snode->source_timer,
330 				 gnode->group_timer.timer.expires);
331 		break;
332 	case AMT_ACT_STATUS_FWD_NEW:
333 		snode->status = AMT_SOURCE_STATUS_FWD;
334 		snode->flags = AMT_SOURCE_NEW;
335 		break;
336 	case AMT_ACT_STATUS_D_FWD_NEW:
337 		snode->status = AMT_SOURCE_STATUS_D_FWD;
338 		snode->flags = AMT_SOURCE_NEW;
339 		break;
340 	case AMT_ACT_STATUS_NONE_NEW:
341 		cancel_delayed_work(&snode->source_timer);
342 		snode->status = AMT_SOURCE_STATUS_NONE;
343 		snode->flags = AMT_SOURCE_NEW;
344 		break;
345 	default:
346 		WARN_ON_ONCE(1);
347 		return;
348 	}
349 
350 	if (!gnode->v6)
351 		netdev_dbg(amt->dev, "Source %pI4 from %pI4 Acted %s\n",
352 			   &snode->source_addr.ip4,
353 			   &gnode->group_addr.ip4,
354 			   action_str[act]);
355 #if IS_ENABLED(CONFIG_IPV6)
356 	else
357 		netdev_dbg(amt->dev, "Source %pI6 from %pI6 Acted %s\n",
358 			   &snode->source_addr.ip6,
359 			   &gnode->group_addr.ip6,
360 			   action_str[act]);
361 #endif
362 }
363 
364 static struct amt_source_node *amt_alloc_snode(struct amt_group_node *gnode,
365 					       union amt_addr *src)
366 {
367 	struct amt_source_node *snode;
368 
369 	snode = kzalloc(sizeof(*snode), GFP_ATOMIC);
370 	if (!snode)
371 		return NULL;
372 
373 	memcpy(&snode->source_addr, src, sizeof(union amt_addr));
374 	snode->gnode = gnode;
375 	snode->status = AMT_SOURCE_STATUS_NONE;
376 	snode->flags = AMT_SOURCE_NEW;
377 	INIT_HLIST_NODE(&snode->node);
378 	INIT_DELAYED_WORK(&snode->source_timer, amt_source_work);
379 
380 	return snode;
381 }
382 
383 /* RFC 3810 - 7.2.2.  Definition of Filter Timers
384  *
385  *  Router Mode          Filter Timer         Actions/Comments
386  *  -----------       -----------------       ----------------
387  *
388  *    INCLUDE             Not Used            All listeners in
389  *                                            INCLUDE mode.
390  *
391  *    EXCLUDE             Timer > 0           At least one listener
392  *                                            in EXCLUDE mode.
393  *
394  *    EXCLUDE             Timer == 0          No more listeners in
395  *                                            EXCLUDE mode for the
396  *                                            multicast address.
397  *                                            If the Requested List
398  *                                            is empty, delete
399  *                                            Multicast Address
400  *                                            Record.  If not, switch
401  *                                            to INCLUDE filter mode;
402  *                                            the sources in the
403  *                                            Requested List are
404  *                                            moved to the Include
405  *                                            List, and the Exclude
406  *                                            List is deleted.
407  */
408 static void amt_group_work(struct work_struct *work)
409 {
410 	struct amt_group_node *gnode = container_of(to_delayed_work(work),
411 						    struct amt_group_node,
412 						    group_timer);
413 	struct amt_tunnel_list *tunnel = gnode->tunnel_list;
414 	struct amt_dev *amt = gnode->amt;
415 	struct amt_source_node *snode;
416 	bool delete_group = true;
417 	struct hlist_node *t;
418 	int i, buckets;
419 
420 	buckets = amt->hash_buckets;
421 
422 	spin_lock_bh(&tunnel->lock);
423 	if (gnode->filter_mode == MCAST_INCLUDE) {
424 		/* Not Used */
425 		spin_unlock_bh(&tunnel->lock);
426 		goto out;
427 	}
428 
429 	rcu_read_lock();
430 	for (i = 0; i < buckets; i++) {
431 		hlist_for_each_entry_safe(snode, t,
432 					  &gnode->sources[i], node) {
433 			if (!delayed_work_pending(&snode->source_timer) ||
434 			    snode->status == AMT_SOURCE_STATUS_D_FWD) {
435 				amt_destroy_source(snode);
436 			} else {
437 				delete_group = false;
438 				snode->status = AMT_SOURCE_STATUS_FWD;
439 			}
440 		}
441 	}
442 	if (delete_group)
443 		amt_del_group(amt, gnode);
444 	else
445 		gnode->filter_mode = MCAST_INCLUDE;
446 	rcu_read_unlock();
447 	spin_unlock_bh(&tunnel->lock);
448 out:
449 	dev_put(amt->dev);
450 }
451 
452 /* Non-existant group is created as INCLUDE {empty}:
453  *
454  * RFC 3376 - 5.1. Action on Change of Interface State
455  *
456  * If no interface state existed for that multicast address before
457  * the change (i.e., the change consisted of creating a new
458  * per-interface record), or if no state exists after the change
459  * (i.e., the change consisted of deleting a per-interface record),
460  * then the "non-existent" state is considered to have a filter mode
461  * of INCLUDE and an empty source list.
462  */
463 static struct amt_group_node *amt_add_group(struct amt_dev *amt,
464 					    struct amt_tunnel_list *tunnel,
465 					    union amt_addr *group,
466 					    union amt_addr *host,
467 					    bool v6)
468 {
469 	struct amt_group_node *gnode;
470 	u32 hash;
471 	int i;
472 
473 	if (tunnel->nr_groups >= amt->max_groups)
474 		return ERR_PTR(-ENOSPC);
475 
476 	gnode = kzalloc(sizeof(*gnode) +
477 			(sizeof(struct hlist_head) * amt->hash_buckets),
478 			GFP_ATOMIC);
479 	if (unlikely(!gnode))
480 		return ERR_PTR(-ENOMEM);
481 
482 	gnode->amt = amt;
483 	gnode->group_addr = *group;
484 	gnode->host_addr = *host;
485 	gnode->v6 = v6;
486 	gnode->tunnel_list = tunnel;
487 	gnode->filter_mode = MCAST_INCLUDE;
488 	INIT_HLIST_NODE(&gnode->node);
489 	INIT_DELAYED_WORK(&gnode->group_timer, amt_group_work);
490 	for (i = 0; i < amt->hash_buckets; i++)
491 		INIT_HLIST_HEAD(&gnode->sources[i]);
492 
493 	hash = amt_group_hash(tunnel, group);
494 	hlist_add_head_rcu(&gnode->node, &tunnel->groups[hash]);
495 	tunnel->nr_groups++;
496 
497 	if (!gnode->v6)
498 		netdev_dbg(amt->dev, "Join group %pI4\n",
499 			   &gnode->group_addr.ip4);
500 #if IS_ENABLED(CONFIG_IPV6)
501 	else
502 		netdev_dbg(amt->dev, "Join group %pI6\n",
503 			   &gnode->group_addr.ip6);
504 #endif
505 
506 	return gnode;
507 }
508 
509 static struct sk_buff *amt_build_igmp_gq(struct amt_dev *amt)
510 {
511 	u8 ra[AMT_IPHDR_OPTS] = { IPOPT_RA, 4, 0, 0 };
512 	int hlen = LL_RESERVED_SPACE(amt->dev);
513 	int tlen = amt->dev->needed_tailroom;
514 	struct igmpv3_query *ihv3;
515 	void *csum_start = NULL;
516 	__sum16 *csum = NULL;
517 	struct sk_buff *skb;
518 	struct ethhdr *eth;
519 	struct iphdr *iph;
520 	unsigned int len;
521 	int offset;
522 
523 	len = hlen + tlen + sizeof(*iph) + AMT_IPHDR_OPTS + sizeof(*ihv3);
524 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
525 	if (!skb)
526 		return NULL;
527 
528 	skb_reserve(skb, hlen);
529 	skb_push(skb, sizeof(*eth));
530 	skb->protocol = htons(ETH_P_IP);
531 	skb_reset_mac_header(skb);
532 	skb->priority = TC_PRIO_CONTROL;
533 	skb_put(skb, sizeof(*iph));
534 	skb_put_data(skb, ra, sizeof(ra));
535 	skb_put(skb, sizeof(*ihv3));
536 	skb_pull(skb, sizeof(*eth));
537 	skb_reset_network_header(skb);
538 
539 	iph		= ip_hdr(skb);
540 	iph->version	= 4;
541 	iph->ihl	= (sizeof(struct iphdr) + AMT_IPHDR_OPTS) >> 2;
542 	iph->tos	= AMT_TOS;
543 	iph->tot_len	= htons(sizeof(*iph) + AMT_IPHDR_OPTS + sizeof(*ihv3));
544 	iph->frag_off	= htons(IP_DF);
545 	iph->ttl	= 1;
546 	iph->id		= 0;
547 	iph->protocol	= IPPROTO_IGMP;
548 	iph->daddr	= htonl(INADDR_ALLHOSTS_GROUP);
549 	iph->saddr	= htonl(INADDR_ANY);
550 	ip_send_check(iph);
551 
552 	eth = eth_hdr(skb);
553 	ether_addr_copy(eth->h_source, amt->dev->dev_addr);
554 	ip_eth_mc_map(htonl(INADDR_ALLHOSTS_GROUP), eth->h_dest);
555 	eth->h_proto = htons(ETH_P_IP);
556 
557 	ihv3		= skb_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
558 	skb_reset_transport_header(skb);
559 	ihv3->type	= IGMP_HOST_MEMBERSHIP_QUERY;
560 	ihv3->code	= 1;
561 	ihv3->group	= 0;
562 	ihv3->qqic	= amt->qi;
563 	ihv3->nsrcs	= 0;
564 	ihv3->resv	= 0;
565 	ihv3->suppress	= false;
566 	ihv3->qrv	= amt->net->ipv4.sysctl_igmp_qrv;
567 	ihv3->csum	= 0;
568 	csum		= &ihv3->csum;
569 	csum_start	= (void *)ihv3;
570 	*csum		= ip_compute_csum(csum_start, sizeof(*ihv3));
571 	offset		= skb_transport_offset(skb);
572 	skb->csum	= skb_checksum(skb, offset, skb->len - offset, 0);
573 	skb->ip_summed	= CHECKSUM_NONE;
574 
575 	skb_push(skb, sizeof(*eth) + sizeof(*iph) + AMT_IPHDR_OPTS);
576 
577 	return skb;
578 }
579 
580 static void __amt_update_gw_status(struct amt_dev *amt, enum amt_status status,
581 				   bool validate)
582 {
583 	if (validate && amt->status >= status)
584 		return;
585 	netdev_dbg(amt->dev, "Update GW status %s -> %s",
586 		   status_str[amt->status], status_str[status]);
587 	amt->status = status;
588 }
589 
590 static void __amt_update_relay_status(struct amt_tunnel_list *tunnel,
591 				      enum amt_status status,
592 				      bool validate)
593 {
594 	if (validate && tunnel->status >= status)
595 		return;
596 	netdev_dbg(tunnel->amt->dev,
597 		   "Update Tunnel(IP = %pI4, PORT = %u) status %s -> %s",
598 		   &tunnel->ip4, ntohs(tunnel->source_port),
599 		   status_str[tunnel->status], status_str[status]);
600 	tunnel->status = status;
601 }
602 
603 static void amt_update_gw_status(struct amt_dev *amt, enum amt_status status,
604 				 bool validate)
605 {
606 	spin_lock_bh(&amt->lock);
607 	__amt_update_gw_status(amt, status, validate);
608 	spin_unlock_bh(&amt->lock);
609 }
610 
611 static void amt_update_relay_status(struct amt_tunnel_list *tunnel,
612 				    enum amt_status status, bool validate)
613 {
614 	spin_lock_bh(&tunnel->lock);
615 	__amt_update_relay_status(tunnel, status, validate);
616 	spin_unlock_bh(&tunnel->lock);
617 }
618 
619 static void amt_send_discovery(struct amt_dev *amt)
620 {
621 	struct amt_header_discovery *amtd;
622 	int hlen, tlen, offset;
623 	struct socket *sock;
624 	struct udphdr *udph;
625 	struct sk_buff *skb;
626 	struct iphdr *iph;
627 	struct rtable *rt;
628 	struct flowi4 fl4;
629 	u32 len;
630 	int err;
631 
632 	rcu_read_lock();
633 	sock = rcu_dereference(amt->sock);
634 	if (!sock)
635 		goto out;
636 
637 	if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
638 		goto out;
639 
640 	rt = ip_route_output_ports(amt->net, &fl4, sock->sk,
641 				   amt->discovery_ip, amt->local_ip,
642 				   amt->gw_port, amt->relay_port,
643 				   IPPROTO_UDP, 0,
644 				   amt->stream_dev->ifindex);
645 	if (IS_ERR(rt)) {
646 		amt->dev->stats.tx_errors++;
647 		goto out;
648 	}
649 
650 	hlen = LL_RESERVED_SPACE(amt->dev);
651 	tlen = amt->dev->needed_tailroom;
652 	len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amtd);
653 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
654 	if (!skb) {
655 		ip_rt_put(rt);
656 		amt->dev->stats.tx_errors++;
657 		goto out;
658 	}
659 
660 	skb->priority = TC_PRIO_CONTROL;
661 	skb_dst_set(skb, &rt->dst);
662 
663 	len = sizeof(*iph) + sizeof(*udph) + sizeof(*amtd);
664 	skb_reset_network_header(skb);
665 	skb_put(skb, len);
666 	amtd = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
667 	amtd->version	= 0;
668 	amtd->type	= AMT_MSG_DISCOVERY;
669 	amtd->reserved	= 0;
670 	amtd->nonce	= amt->nonce;
671 	skb_push(skb, sizeof(*udph));
672 	skb_reset_transport_header(skb);
673 	udph		= udp_hdr(skb);
674 	udph->source	= amt->gw_port;
675 	udph->dest	= amt->relay_port;
676 	udph->len	= htons(sizeof(*udph) + sizeof(*amtd));
677 	udph->check	= 0;
678 	offset = skb_transport_offset(skb);
679 	skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
680 	udph->check = csum_tcpudp_magic(amt->local_ip, amt->discovery_ip,
681 					sizeof(*udph) + sizeof(*amtd),
682 					IPPROTO_UDP, skb->csum);
683 
684 	skb_push(skb, sizeof(*iph));
685 	iph		= ip_hdr(skb);
686 	iph->version	= 4;
687 	iph->ihl	= (sizeof(struct iphdr)) >> 2;
688 	iph->tos	= AMT_TOS;
689 	iph->frag_off	= 0;
690 	iph->ttl	= ip4_dst_hoplimit(&rt->dst);
691 	iph->daddr	= amt->discovery_ip;
692 	iph->saddr	= amt->local_ip;
693 	iph->protocol	= IPPROTO_UDP;
694 	iph->tot_len	= htons(len);
695 
696 	skb->ip_summed = CHECKSUM_NONE;
697 	ip_select_ident(amt->net, skb, NULL);
698 	ip_send_check(iph);
699 	err = ip_local_out(amt->net, sock->sk, skb);
700 	if (unlikely(net_xmit_eval(err)))
701 		amt->dev->stats.tx_errors++;
702 
703 	spin_lock_bh(&amt->lock);
704 	__amt_update_gw_status(amt, AMT_STATUS_SENT_DISCOVERY, true);
705 	spin_unlock_bh(&amt->lock);
706 out:
707 	rcu_read_unlock();
708 }
709 
710 static void amt_send_request(struct amt_dev *amt, bool v6)
711 {
712 	struct amt_header_request *amtrh;
713 	int hlen, tlen, offset;
714 	struct socket *sock;
715 	struct udphdr *udph;
716 	struct sk_buff *skb;
717 	struct iphdr *iph;
718 	struct rtable *rt;
719 	struct flowi4 fl4;
720 	u32 len;
721 	int err;
722 
723 	rcu_read_lock();
724 	sock = rcu_dereference(amt->sock);
725 	if (!sock)
726 		goto out;
727 
728 	if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
729 		goto out;
730 
731 	rt = ip_route_output_ports(amt->net, &fl4, sock->sk,
732 				   amt->remote_ip, amt->local_ip,
733 				   amt->gw_port, amt->relay_port,
734 				   IPPROTO_UDP, 0,
735 				   amt->stream_dev->ifindex);
736 	if (IS_ERR(rt)) {
737 		amt->dev->stats.tx_errors++;
738 		goto out;
739 	}
740 
741 	hlen = LL_RESERVED_SPACE(amt->dev);
742 	tlen = amt->dev->needed_tailroom;
743 	len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amtrh);
744 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
745 	if (!skb) {
746 		ip_rt_put(rt);
747 		amt->dev->stats.tx_errors++;
748 		goto out;
749 	}
750 
751 	skb->priority = TC_PRIO_CONTROL;
752 	skb_dst_set(skb, &rt->dst);
753 
754 	len = sizeof(*iph) + sizeof(*udph) + sizeof(*amtrh);
755 	skb_reset_network_header(skb);
756 	skb_put(skb, len);
757 	amtrh = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
758 	amtrh->version	 = 0;
759 	amtrh->type	 = AMT_MSG_REQUEST;
760 	amtrh->reserved1 = 0;
761 	amtrh->p	 = v6;
762 	amtrh->reserved2 = 0;
763 	amtrh->nonce	 = amt->nonce;
764 	skb_push(skb, sizeof(*udph));
765 	skb_reset_transport_header(skb);
766 	udph		= udp_hdr(skb);
767 	udph->source	= amt->gw_port;
768 	udph->dest	= amt->relay_port;
769 	udph->len	= htons(sizeof(*amtrh) + sizeof(*udph));
770 	udph->check	= 0;
771 	offset = skb_transport_offset(skb);
772 	skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
773 	udph->check = csum_tcpudp_magic(amt->local_ip, amt->remote_ip,
774 					sizeof(*udph) + sizeof(*amtrh),
775 					IPPROTO_UDP, skb->csum);
776 
777 	skb_push(skb, sizeof(*iph));
778 	iph		= ip_hdr(skb);
779 	iph->version	= 4;
780 	iph->ihl	= (sizeof(struct iphdr)) >> 2;
781 	iph->tos	= AMT_TOS;
782 	iph->frag_off	= 0;
783 	iph->ttl	= ip4_dst_hoplimit(&rt->dst);
784 	iph->daddr	= amt->remote_ip;
785 	iph->saddr	= amt->local_ip;
786 	iph->protocol	= IPPROTO_UDP;
787 	iph->tot_len	= htons(len);
788 
789 	skb->ip_summed = CHECKSUM_NONE;
790 	ip_select_ident(amt->net, skb, NULL);
791 	ip_send_check(iph);
792 	err = ip_local_out(amt->net, sock->sk, skb);
793 	if (unlikely(net_xmit_eval(err)))
794 		amt->dev->stats.tx_errors++;
795 
796 out:
797 	rcu_read_unlock();
798 }
799 
800 static void amt_send_igmp_gq(struct amt_dev *amt,
801 			     struct amt_tunnel_list *tunnel)
802 {
803 	struct sk_buff *skb;
804 
805 	skb = amt_build_igmp_gq(amt);
806 	if (!skb)
807 		return;
808 
809 	amt_skb_cb(skb)->tunnel = tunnel;
810 	dev_queue_xmit(skb);
811 }
812 
813 #if IS_ENABLED(CONFIG_IPV6)
814 static struct sk_buff *amt_build_mld_gq(struct amt_dev *amt)
815 {
816 	u8 ra[AMT_IP6HDR_OPTS] = { IPPROTO_ICMPV6, 0, IPV6_TLV_ROUTERALERT,
817 				   2, 0, 0, IPV6_TLV_PAD1, IPV6_TLV_PAD1 };
818 	int hlen = LL_RESERVED_SPACE(amt->dev);
819 	int tlen = amt->dev->needed_tailroom;
820 	struct mld2_query *mld2q;
821 	void *csum_start = NULL;
822 	struct ipv6hdr *ip6h;
823 	struct sk_buff *skb;
824 	struct ethhdr *eth;
825 	u32 len;
826 
827 	len = hlen + tlen + sizeof(*ip6h) + sizeof(ra) + sizeof(*mld2q);
828 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
829 	if (!skb)
830 		return NULL;
831 
832 	skb_reserve(skb, hlen);
833 	skb_push(skb, sizeof(*eth));
834 	skb_reset_mac_header(skb);
835 	eth = eth_hdr(skb);
836 	skb->priority = TC_PRIO_CONTROL;
837 	skb->protocol = htons(ETH_P_IPV6);
838 	skb_put_zero(skb, sizeof(*ip6h));
839 	skb_put_data(skb, ra, sizeof(ra));
840 	skb_put_zero(skb, sizeof(*mld2q));
841 	skb_pull(skb, sizeof(*eth));
842 	skb_reset_network_header(skb);
843 	ip6h			= ipv6_hdr(skb);
844 	ip6h->payload_len	= htons(sizeof(ra) + sizeof(*mld2q));
845 	ip6h->nexthdr		= NEXTHDR_HOP;
846 	ip6h->hop_limit		= 1;
847 	ip6h->daddr		= mld2_all_node;
848 	ip6_flow_hdr(ip6h, 0, 0);
849 
850 	if (ipv6_dev_get_saddr(amt->net, amt->dev, &ip6h->daddr, 0,
851 			       &ip6h->saddr)) {
852 		amt->dev->stats.tx_errors++;
853 		kfree_skb(skb);
854 		return NULL;
855 	}
856 
857 	eth->h_proto = htons(ETH_P_IPV6);
858 	ether_addr_copy(eth->h_source, amt->dev->dev_addr);
859 	ipv6_eth_mc_map(&mld2_all_node, eth->h_dest);
860 
861 	skb_pull(skb, sizeof(*ip6h) + sizeof(ra));
862 	skb_reset_transport_header(skb);
863 	mld2q			= (struct mld2_query *)icmp6_hdr(skb);
864 	mld2q->mld2q_mrc	= htons(1);
865 	mld2q->mld2q_type	= ICMPV6_MGM_QUERY;
866 	mld2q->mld2q_code	= 0;
867 	mld2q->mld2q_cksum	= 0;
868 	mld2q->mld2q_resv1	= 0;
869 	mld2q->mld2q_resv2	= 0;
870 	mld2q->mld2q_suppress	= 0;
871 	mld2q->mld2q_qrv	= amt->qrv;
872 	mld2q->mld2q_nsrcs	= 0;
873 	mld2q->mld2q_qqic	= amt->qi;
874 	csum_start		= (void *)mld2q;
875 	mld2q->mld2q_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
876 					     sizeof(*mld2q),
877 					     IPPROTO_ICMPV6,
878 					     csum_partial(csum_start,
879 							  sizeof(*mld2q), 0));
880 
881 	skb->ip_summed = CHECKSUM_NONE;
882 	skb_push(skb, sizeof(*eth) + sizeof(*ip6h) + sizeof(ra));
883 	return skb;
884 }
885 
886 static void amt_send_mld_gq(struct amt_dev *amt, struct amt_tunnel_list *tunnel)
887 {
888 	struct sk_buff *skb;
889 
890 	skb = amt_build_mld_gq(amt);
891 	if (!skb)
892 		return;
893 
894 	amt_skb_cb(skb)->tunnel = tunnel;
895 	dev_queue_xmit(skb);
896 }
897 #else
898 static void amt_send_mld_gq(struct amt_dev *amt, struct amt_tunnel_list *tunnel)
899 {
900 }
901 #endif
902 
903 static void amt_secret_work(struct work_struct *work)
904 {
905 	struct amt_dev *amt = container_of(to_delayed_work(work),
906 					   struct amt_dev,
907 					   secret_wq);
908 
909 	spin_lock_bh(&amt->lock);
910 	get_random_bytes(&amt->key, sizeof(siphash_key_t));
911 	spin_unlock_bh(&amt->lock);
912 	mod_delayed_work(amt_wq, &amt->secret_wq,
913 			 msecs_to_jiffies(AMT_SECRET_TIMEOUT));
914 }
915 
916 static void amt_discovery_work(struct work_struct *work)
917 {
918 	struct amt_dev *amt = container_of(to_delayed_work(work),
919 					   struct amt_dev,
920 					   discovery_wq);
921 
922 	spin_lock_bh(&amt->lock);
923 	if (amt->status > AMT_STATUS_SENT_DISCOVERY)
924 		goto out;
925 	get_random_bytes(&amt->nonce, sizeof(__be32));
926 	spin_unlock_bh(&amt->lock);
927 
928 	amt_send_discovery(amt);
929 	spin_lock_bh(&amt->lock);
930 out:
931 	mod_delayed_work(amt_wq, &amt->discovery_wq,
932 			 msecs_to_jiffies(AMT_DISCOVERY_TIMEOUT));
933 	spin_unlock_bh(&amt->lock);
934 }
935 
936 static void amt_req_work(struct work_struct *work)
937 {
938 	struct amt_dev *amt = container_of(to_delayed_work(work),
939 					   struct amt_dev,
940 					   req_wq);
941 	u32 exp;
942 
943 	spin_lock_bh(&amt->lock);
944 	if (amt->status < AMT_STATUS_RECEIVED_ADVERTISEMENT)
945 		goto out;
946 
947 	if (amt->req_cnt > AMT_MAX_REQ_COUNT) {
948 		netdev_dbg(amt->dev, "Gateway is not ready");
949 		amt->qi = AMT_INIT_REQ_TIMEOUT;
950 		amt->ready4 = false;
951 		amt->ready6 = false;
952 		amt->remote_ip = 0;
953 		__amt_update_gw_status(amt, AMT_STATUS_INIT, false);
954 		amt->req_cnt = 0;
955 		goto out;
956 	}
957 	spin_unlock_bh(&amt->lock);
958 
959 	amt_send_request(amt, false);
960 	amt_send_request(amt, true);
961 	spin_lock_bh(&amt->lock);
962 	__amt_update_gw_status(amt, AMT_STATUS_SENT_REQUEST, true);
963 	amt->req_cnt++;
964 out:
965 	exp = min_t(u32, (1 * (1 << amt->req_cnt)), AMT_MAX_REQ_TIMEOUT);
966 	mod_delayed_work(amt_wq, &amt->req_wq, msecs_to_jiffies(exp * 1000));
967 	spin_unlock_bh(&amt->lock);
968 }
969 
970 static bool amt_send_membership_update(struct amt_dev *amt,
971 				       struct sk_buff *skb,
972 				       bool v6)
973 {
974 	struct amt_header_membership_update *amtmu;
975 	struct socket *sock;
976 	struct iphdr *iph;
977 	struct flowi4 fl4;
978 	struct rtable *rt;
979 	int err;
980 
981 	sock = rcu_dereference_bh(amt->sock);
982 	if (!sock)
983 		return true;
984 
985 	err = skb_cow_head(skb, LL_RESERVED_SPACE(amt->dev) + sizeof(*amtmu) +
986 			   sizeof(*iph) + sizeof(struct udphdr));
987 	if (err)
988 		return true;
989 
990 	skb_reset_inner_headers(skb);
991 	memset(&fl4, 0, sizeof(struct flowi4));
992 	fl4.flowi4_oif         = amt->stream_dev->ifindex;
993 	fl4.daddr              = amt->remote_ip;
994 	fl4.saddr              = amt->local_ip;
995 	fl4.flowi4_tos         = AMT_TOS;
996 	fl4.flowi4_proto       = IPPROTO_UDP;
997 	rt = ip_route_output_key(amt->net, &fl4);
998 	if (IS_ERR(rt)) {
999 		netdev_dbg(amt->dev, "no route to %pI4\n", &amt->remote_ip);
1000 		return true;
1001 	}
1002 
1003 	amtmu			= skb_push(skb, sizeof(*amtmu));
1004 	amtmu->version		= 0;
1005 	amtmu->type		= AMT_MSG_MEMBERSHIP_UPDATE;
1006 	amtmu->reserved		= 0;
1007 	amtmu->nonce		= amt->nonce;
1008 	amtmu->response_mac	= amt->mac;
1009 
1010 	if (!v6)
1011 		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1012 	else
1013 		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1014 	udp_tunnel_xmit_skb(rt, sock->sk, skb,
1015 			    fl4.saddr,
1016 			    fl4.daddr,
1017 			    AMT_TOS,
1018 			    ip4_dst_hoplimit(&rt->dst),
1019 			    0,
1020 			    amt->gw_port,
1021 			    amt->relay_port,
1022 			    false,
1023 			    false);
1024 	amt_update_gw_status(amt, AMT_STATUS_SENT_UPDATE, true);
1025 	return false;
1026 }
1027 
1028 static void amt_send_multicast_data(struct amt_dev *amt,
1029 				    const struct sk_buff *oskb,
1030 				    struct amt_tunnel_list *tunnel,
1031 				    bool v6)
1032 {
1033 	struct amt_header_mcast_data *amtmd;
1034 	struct socket *sock;
1035 	struct sk_buff *skb;
1036 	struct iphdr *iph;
1037 	struct flowi4 fl4;
1038 	struct rtable *rt;
1039 
1040 	sock = rcu_dereference_bh(amt->sock);
1041 	if (!sock)
1042 		return;
1043 
1044 	skb = skb_copy_expand(oskb, sizeof(*amtmd) + sizeof(*iph) +
1045 			      sizeof(struct udphdr), 0, GFP_ATOMIC);
1046 	if (!skb)
1047 		return;
1048 
1049 	skb_reset_inner_headers(skb);
1050 	memset(&fl4, 0, sizeof(struct flowi4));
1051 	fl4.flowi4_oif         = amt->stream_dev->ifindex;
1052 	fl4.daddr              = tunnel->ip4;
1053 	fl4.saddr              = amt->local_ip;
1054 	fl4.flowi4_proto       = IPPROTO_UDP;
1055 	rt = ip_route_output_key(amt->net, &fl4);
1056 	if (IS_ERR(rt)) {
1057 		netdev_dbg(amt->dev, "no route to %pI4\n", &tunnel->ip4);
1058 		kfree_skb(skb);
1059 		return;
1060 	}
1061 
1062 	amtmd = skb_push(skb, sizeof(*amtmd));
1063 	amtmd->version = 0;
1064 	amtmd->reserved = 0;
1065 	amtmd->type = AMT_MSG_MULTICAST_DATA;
1066 
1067 	if (!v6)
1068 		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1069 	else
1070 		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1071 	udp_tunnel_xmit_skb(rt, sock->sk, skb,
1072 			    fl4.saddr,
1073 			    fl4.daddr,
1074 			    AMT_TOS,
1075 			    ip4_dst_hoplimit(&rt->dst),
1076 			    0,
1077 			    amt->relay_port,
1078 			    tunnel->source_port,
1079 			    false,
1080 			    false);
1081 }
1082 
1083 static bool amt_send_membership_query(struct amt_dev *amt,
1084 				      struct sk_buff *skb,
1085 				      struct amt_tunnel_list *tunnel,
1086 				      bool v6)
1087 {
1088 	struct amt_header_membership_query *amtmq;
1089 	struct socket *sock;
1090 	struct rtable *rt;
1091 	struct flowi4 fl4;
1092 	int err;
1093 
1094 	sock = rcu_dereference_bh(amt->sock);
1095 	if (!sock)
1096 		return true;
1097 
1098 	err = skb_cow_head(skb, LL_RESERVED_SPACE(amt->dev) + sizeof(*amtmq) +
1099 			   sizeof(struct iphdr) + sizeof(struct udphdr));
1100 	if (err)
1101 		return true;
1102 
1103 	skb_reset_inner_headers(skb);
1104 	memset(&fl4, 0, sizeof(struct flowi4));
1105 	fl4.flowi4_oif         = amt->stream_dev->ifindex;
1106 	fl4.daddr              = tunnel->ip4;
1107 	fl4.saddr              = amt->local_ip;
1108 	fl4.flowi4_tos         = AMT_TOS;
1109 	fl4.flowi4_proto       = IPPROTO_UDP;
1110 	rt = ip_route_output_key(amt->net, &fl4);
1111 	if (IS_ERR(rt)) {
1112 		netdev_dbg(amt->dev, "no route to %pI4\n", &tunnel->ip4);
1113 		return true;
1114 	}
1115 
1116 	amtmq		= skb_push(skb, sizeof(*amtmq));
1117 	amtmq->version	= 0;
1118 	amtmq->type	= AMT_MSG_MEMBERSHIP_QUERY;
1119 	amtmq->reserved = 0;
1120 	amtmq->l	= 0;
1121 	amtmq->g	= 0;
1122 	amtmq->nonce	= tunnel->nonce;
1123 	amtmq->response_mac = tunnel->mac;
1124 
1125 	if (!v6)
1126 		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1127 	else
1128 		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1129 	udp_tunnel_xmit_skb(rt, sock->sk, skb,
1130 			    fl4.saddr,
1131 			    fl4.daddr,
1132 			    AMT_TOS,
1133 			    ip4_dst_hoplimit(&rt->dst),
1134 			    0,
1135 			    amt->relay_port,
1136 			    tunnel->source_port,
1137 			    false,
1138 			    false);
1139 	amt_update_relay_status(tunnel, AMT_STATUS_SENT_QUERY, true);
1140 	return false;
1141 }
1142 
1143 static netdev_tx_t amt_dev_xmit(struct sk_buff *skb, struct net_device *dev)
1144 {
1145 	struct amt_dev *amt = netdev_priv(dev);
1146 	struct amt_tunnel_list *tunnel;
1147 	struct amt_group_node *gnode;
1148 	union amt_addr group = {0,};
1149 #if IS_ENABLED(CONFIG_IPV6)
1150 	struct ipv6hdr *ip6h;
1151 	struct mld_msg *mld;
1152 #endif
1153 	bool report = false;
1154 	struct igmphdr *ih;
1155 	bool query = false;
1156 	struct iphdr *iph;
1157 	bool data = false;
1158 	bool v6 = false;
1159 	u32 hash;
1160 
1161 	iph = ip_hdr(skb);
1162 	if (iph->version == 4) {
1163 		if (!ipv4_is_multicast(iph->daddr))
1164 			goto free;
1165 
1166 		if (!ip_mc_check_igmp(skb)) {
1167 			ih = igmp_hdr(skb);
1168 			switch (ih->type) {
1169 			case IGMPV3_HOST_MEMBERSHIP_REPORT:
1170 			case IGMP_HOST_MEMBERSHIP_REPORT:
1171 				report = true;
1172 				break;
1173 			case IGMP_HOST_MEMBERSHIP_QUERY:
1174 				query = true;
1175 				break;
1176 			default:
1177 				goto free;
1178 			}
1179 		} else {
1180 			data = true;
1181 		}
1182 		v6 = false;
1183 		group.ip4 = iph->daddr;
1184 #if IS_ENABLED(CONFIG_IPV6)
1185 	} else if (iph->version == 6) {
1186 		ip6h = ipv6_hdr(skb);
1187 		if (!ipv6_addr_is_multicast(&ip6h->daddr))
1188 			goto free;
1189 
1190 		if (!ipv6_mc_check_mld(skb)) {
1191 			mld = (struct mld_msg *)skb_transport_header(skb);
1192 			switch (mld->mld_type) {
1193 			case ICMPV6_MGM_REPORT:
1194 			case ICMPV6_MLD2_REPORT:
1195 				report = true;
1196 				break;
1197 			case ICMPV6_MGM_QUERY:
1198 				query = true;
1199 				break;
1200 			default:
1201 				goto free;
1202 			}
1203 		} else {
1204 			data = true;
1205 		}
1206 		v6 = true;
1207 		group.ip6 = ip6h->daddr;
1208 #endif
1209 	} else {
1210 		dev->stats.tx_errors++;
1211 		goto free;
1212 	}
1213 
1214 	if (!pskb_may_pull(skb, sizeof(struct ethhdr)))
1215 		goto free;
1216 
1217 	skb_pull(skb, sizeof(struct ethhdr));
1218 
1219 	if (amt->mode == AMT_MODE_GATEWAY) {
1220 		/* Gateway only passes IGMP/MLD packets */
1221 		if (!report)
1222 			goto free;
1223 		if ((!v6 && !amt->ready4) || (v6 && !amt->ready6))
1224 			goto free;
1225 		if (amt_send_membership_update(amt, skb,  v6))
1226 			goto free;
1227 		goto unlock;
1228 	} else if (amt->mode == AMT_MODE_RELAY) {
1229 		if (query) {
1230 			tunnel = amt_skb_cb(skb)->tunnel;
1231 			if (!tunnel) {
1232 				WARN_ON(1);
1233 				goto free;
1234 			}
1235 
1236 			/* Do not forward unexpected query */
1237 			if (amt_send_membership_query(amt, skb, tunnel, v6))
1238 				goto free;
1239 			goto unlock;
1240 		}
1241 
1242 		if (!data)
1243 			goto free;
1244 		list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list) {
1245 			hash = amt_group_hash(tunnel, &group);
1246 			hlist_for_each_entry_rcu(gnode, &tunnel->groups[hash],
1247 						 node) {
1248 				if (!v6) {
1249 					if (gnode->group_addr.ip4 == iph->daddr)
1250 						goto found;
1251 #if IS_ENABLED(CONFIG_IPV6)
1252 				} else {
1253 					if (ipv6_addr_equal(&gnode->group_addr.ip6,
1254 							    &ip6h->daddr))
1255 						goto found;
1256 #endif
1257 				}
1258 			}
1259 			continue;
1260 found:
1261 			amt_send_multicast_data(amt, skb, tunnel, v6);
1262 		}
1263 	}
1264 
1265 	dev_kfree_skb(skb);
1266 	return NETDEV_TX_OK;
1267 free:
1268 	dev_kfree_skb(skb);
1269 unlock:
1270 	dev->stats.tx_dropped++;
1271 	return NETDEV_TX_OK;
1272 }
1273 
1274 static int amt_parse_type(struct sk_buff *skb)
1275 {
1276 	struct amt_header *amth;
1277 
1278 	if (!pskb_may_pull(skb, sizeof(struct udphdr) +
1279 			   sizeof(struct amt_header)))
1280 		return -1;
1281 
1282 	amth = (struct amt_header *)(udp_hdr(skb) + 1);
1283 
1284 	if (amth->version != 0)
1285 		return -1;
1286 
1287 	if (amth->type >= __AMT_MSG_MAX || !amth->type)
1288 		return -1;
1289 	return amth->type;
1290 }
1291 
1292 static void amt_clear_groups(struct amt_tunnel_list *tunnel)
1293 {
1294 	struct amt_dev *amt = tunnel->amt;
1295 	struct amt_group_node *gnode;
1296 	struct hlist_node *t;
1297 	int i;
1298 
1299 	spin_lock_bh(&tunnel->lock);
1300 	rcu_read_lock();
1301 	for (i = 0; i < amt->hash_buckets; i++)
1302 		hlist_for_each_entry_safe(gnode, t, &tunnel->groups[i], node)
1303 			amt_del_group(amt, gnode);
1304 	rcu_read_unlock();
1305 	spin_unlock_bh(&tunnel->lock);
1306 }
1307 
1308 static void amt_tunnel_expire(struct work_struct *work)
1309 {
1310 	struct amt_tunnel_list *tunnel = container_of(to_delayed_work(work),
1311 						      struct amt_tunnel_list,
1312 						      gc_wq);
1313 	struct amt_dev *amt = tunnel->amt;
1314 
1315 	spin_lock_bh(&amt->lock);
1316 	rcu_read_lock();
1317 	list_del_rcu(&tunnel->list);
1318 	amt->nr_tunnels--;
1319 	amt_clear_groups(tunnel);
1320 	rcu_read_unlock();
1321 	spin_unlock_bh(&amt->lock);
1322 	kfree_rcu(tunnel, rcu);
1323 }
1324 
1325 static void amt_cleanup_srcs(struct amt_dev *amt,
1326 			     struct amt_tunnel_list *tunnel,
1327 			     struct amt_group_node *gnode)
1328 {
1329 	struct amt_source_node *snode;
1330 	struct hlist_node *t;
1331 	int i;
1332 
1333 	/* Delete old sources */
1334 	for (i = 0; i < amt->hash_buckets; i++) {
1335 		hlist_for_each_entry_safe(snode, t, &gnode->sources[i], node) {
1336 			if (snode->flags == AMT_SOURCE_OLD)
1337 				amt_destroy_source(snode);
1338 		}
1339 	}
1340 
1341 	/* switch from new to old */
1342 	for (i = 0; i < amt->hash_buckets; i++)  {
1343 		hlist_for_each_entry_rcu(snode, &gnode->sources[i], node) {
1344 			snode->flags = AMT_SOURCE_OLD;
1345 			if (!gnode->v6)
1346 				netdev_dbg(snode->gnode->amt->dev,
1347 					   "Add source as OLD %pI4 from %pI4\n",
1348 					   &snode->source_addr.ip4,
1349 					   &gnode->group_addr.ip4);
1350 #if IS_ENABLED(CONFIG_IPV6)
1351 			else
1352 				netdev_dbg(snode->gnode->amt->dev,
1353 					   "Add source as OLD %pI6 from %pI6\n",
1354 					   &snode->source_addr.ip6,
1355 					   &gnode->group_addr.ip6);
1356 #endif
1357 		}
1358 	}
1359 }
1360 
1361 static void amt_add_srcs(struct amt_dev *amt, struct amt_tunnel_list *tunnel,
1362 			 struct amt_group_node *gnode, void *grec,
1363 			 bool v6)
1364 {
1365 	struct igmpv3_grec *igmp_grec;
1366 	struct amt_source_node *snode;
1367 #if IS_ENABLED(CONFIG_IPV6)
1368 	struct mld2_grec *mld_grec;
1369 #endif
1370 	union amt_addr src = {0,};
1371 	u16 nsrcs;
1372 	u32 hash;
1373 	int i;
1374 
1375 	if (!v6) {
1376 		igmp_grec = (struct igmpv3_grec *)grec;
1377 		nsrcs = ntohs(igmp_grec->grec_nsrcs);
1378 	} else {
1379 #if IS_ENABLED(CONFIG_IPV6)
1380 		mld_grec = (struct mld2_grec *)grec;
1381 		nsrcs = ntohs(mld_grec->grec_nsrcs);
1382 #else
1383 	return;
1384 #endif
1385 	}
1386 	for (i = 0; i < nsrcs; i++) {
1387 		if (tunnel->nr_sources >= amt->max_sources)
1388 			return;
1389 		if (!v6)
1390 			src.ip4 = igmp_grec->grec_src[i];
1391 #if IS_ENABLED(CONFIG_IPV6)
1392 		else
1393 			memcpy(&src.ip6, &mld_grec->grec_src[i],
1394 			       sizeof(struct in6_addr));
1395 #endif
1396 		if (amt_lookup_src(tunnel, gnode, AMT_FILTER_ALL, &src))
1397 			continue;
1398 
1399 		snode = amt_alloc_snode(gnode, &src);
1400 		if (snode) {
1401 			hash = amt_source_hash(tunnel, &snode->source_addr);
1402 			hlist_add_head_rcu(&snode->node, &gnode->sources[hash]);
1403 			tunnel->nr_sources++;
1404 			gnode->nr_sources++;
1405 
1406 			if (!gnode->v6)
1407 				netdev_dbg(snode->gnode->amt->dev,
1408 					   "Add source as NEW %pI4 from %pI4\n",
1409 					   &snode->source_addr.ip4,
1410 					   &gnode->group_addr.ip4);
1411 #if IS_ENABLED(CONFIG_IPV6)
1412 			else
1413 				netdev_dbg(snode->gnode->amt->dev,
1414 					   "Add source as NEW %pI6 from %pI6\n",
1415 					   &snode->source_addr.ip6,
1416 					   &gnode->group_addr.ip6);
1417 #endif
1418 		}
1419 	}
1420 }
1421 
1422 /* Router State   Report Rec'd New Router State
1423  * ------------   ------------ ----------------
1424  * EXCLUDE (X,Y)  IS_IN (A)    EXCLUDE (X+A,Y-A)
1425  *
1426  * -----------+-----------+-----------+
1427  *            |    OLD    |    NEW    |
1428  * -----------+-----------+-----------+
1429  *    FWD     |     X     |    X+A    |
1430  * -----------+-----------+-----------+
1431  *    D_FWD   |     Y     |    Y-A    |
1432  * -----------+-----------+-----------+
1433  *    NONE    |           |     A     |
1434  * -----------+-----------+-----------+
1435  *
1436  * a) Received sources are NONE/NEW
1437  * b) All NONE will be deleted by amt_cleanup_srcs().
1438  * c) All OLD will be deleted by amt_cleanup_srcs().
1439  * d) After delete, NEW source will be switched to OLD.
1440  */
1441 static void amt_lookup_act_srcs(struct amt_tunnel_list *tunnel,
1442 				struct amt_group_node *gnode,
1443 				void *grec,
1444 				enum amt_ops ops,
1445 				enum amt_filter filter,
1446 				enum amt_act act,
1447 				bool v6)
1448 {
1449 	struct amt_dev *amt = tunnel->amt;
1450 	struct amt_source_node *snode;
1451 	struct igmpv3_grec *igmp_grec;
1452 #if IS_ENABLED(CONFIG_IPV6)
1453 	struct mld2_grec *mld_grec;
1454 #endif
1455 	union amt_addr src = {0,};
1456 	struct hlist_node *t;
1457 	u16 nsrcs;
1458 	int i, j;
1459 
1460 	if (!v6) {
1461 		igmp_grec = (struct igmpv3_grec *)grec;
1462 		nsrcs = ntohs(igmp_grec->grec_nsrcs);
1463 	} else {
1464 #if IS_ENABLED(CONFIG_IPV6)
1465 		mld_grec = (struct mld2_grec *)grec;
1466 		nsrcs = ntohs(mld_grec->grec_nsrcs);
1467 #else
1468 	return;
1469 #endif
1470 	}
1471 
1472 	memset(&src, 0, sizeof(union amt_addr));
1473 	switch (ops) {
1474 	case AMT_OPS_INT:
1475 		/* A*B */
1476 		for (i = 0; i < nsrcs; i++) {
1477 			if (!v6)
1478 				src.ip4 = igmp_grec->grec_src[i];
1479 #if IS_ENABLED(CONFIG_IPV6)
1480 			else
1481 				memcpy(&src.ip6, &mld_grec->grec_src[i],
1482 				       sizeof(struct in6_addr));
1483 #endif
1484 			snode = amt_lookup_src(tunnel, gnode, filter, &src);
1485 			if (!snode)
1486 				continue;
1487 			amt_act_src(tunnel, gnode, snode, act);
1488 		}
1489 		break;
1490 	case AMT_OPS_UNI:
1491 		/* A+B */
1492 		for (i = 0; i < amt->hash_buckets; i++) {
1493 			hlist_for_each_entry_safe(snode, t, &gnode->sources[i],
1494 						  node) {
1495 				if (amt_status_filter(snode, filter))
1496 					amt_act_src(tunnel, gnode, snode, act);
1497 			}
1498 		}
1499 		for (i = 0; i < nsrcs; i++) {
1500 			if (!v6)
1501 				src.ip4 = igmp_grec->grec_src[i];
1502 #if IS_ENABLED(CONFIG_IPV6)
1503 			else
1504 				memcpy(&src.ip6, &mld_grec->grec_src[i],
1505 				       sizeof(struct in6_addr));
1506 #endif
1507 			snode = amt_lookup_src(tunnel, gnode, filter, &src);
1508 			if (!snode)
1509 				continue;
1510 			amt_act_src(tunnel, gnode, snode, act);
1511 		}
1512 		break;
1513 	case AMT_OPS_SUB:
1514 		/* A-B */
1515 		for (i = 0; i < amt->hash_buckets; i++) {
1516 			hlist_for_each_entry_safe(snode, t, &gnode->sources[i],
1517 						  node) {
1518 				if (!amt_status_filter(snode, filter))
1519 					continue;
1520 				for (j = 0; j < nsrcs; j++) {
1521 					if (!v6)
1522 						src.ip4 = igmp_grec->grec_src[j];
1523 #if IS_ENABLED(CONFIG_IPV6)
1524 					else
1525 						memcpy(&src.ip6,
1526 						       &mld_grec->grec_src[j],
1527 						       sizeof(struct in6_addr));
1528 #endif
1529 					if (amt_addr_equal(&snode->source_addr,
1530 							   &src))
1531 						goto out_sub;
1532 				}
1533 				amt_act_src(tunnel, gnode, snode, act);
1534 				continue;
1535 out_sub:;
1536 			}
1537 		}
1538 		break;
1539 	case AMT_OPS_SUB_REV:
1540 		/* B-A */
1541 		for (i = 0; i < nsrcs; i++) {
1542 			if (!v6)
1543 				src.ip4 = igmp_grec->grec_src[i];
1544 #if IS_ENABLED(CONFIG_IPV6)
1545 			else
1546 				memcpy(&src.ip6, &mld_grec->grec_src[i],
1547 				       sizeof(struct in6_addr));
1548 #endif
1549 			snode = amt_lookup_src(tunnel, gnode, AMT_FILTER_ALL,
1550 					       &src);
1551 			if (!snode) {
1552 				snode = amt_lookup_src(tunnel, gnode,
1553 						       filter, &src);
1554 				if (snode)
1555 					amt_act_src(tunnel, gnode, snode, act);
1556 			}
1557 		}
1558 		break;
1559 	default:
1560 		netdev_dbg(amt->dev, "Invalid type\n");
1561 		return;
1562 	}
1563 }
1564 
1565 static void amt_mcast_is_in_handler(struct amt_dev *amt,
1566 				    struct amt_tunnel_list *tunnel,
1567 				    struct amt_group_node *gnode,
1568 				    void *grec, void *zero_grec, bool v6)
1569 {
1570 	if (gnode->filter_mode == MCAST_INCLUDE) {
1571 /* Router State   Report Rec'd New Router State        Actions
1572  * ------------   ------------ ----------------        -------
1573  * INCLUDE (A)    IS_IN (B)    INCLUDE (A+B)           (B)=GMI
1574  */
1575 		/* Update IS_IN (B) as FWD/NEW */
1576 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1577 				    AMT_FILTER_NONE_NEW,
1578 				    AMT_ACT_STATUS_FWD_NEW,
1579 				    v6);
1580 		/* Update INCLUDE (A) as NEW */
1581 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1582 				    AMT_FILTER_FWD,
1583 				    AMT_ACT_STATUS_FWD_NEW,
1584 				    v6);
1585 		/* (B)=GMI */
1586 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1587 				    AMT_FILTER_FWD_NEW,
1588 				    AMT_ACT_GMI,
1589 				    v6);
1590 	} else {
1591 /* State        Actions
1592  * ------------   ------------ ----------------        -------
1593  * EXCLUDE (X,Y)  IS_IN (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1594  */
1595 		/* Update (A) in (X, Y) as NONE/NEW */
1596 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1597 				    AMT_FILTER_BOTH,
1598 				    AMT_ACT_STATUS_NONE_NEW,
1599 				    v6);
1600 		/* Update FWD/OLD as FWD/NEW */
1601 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1602 				    AMT_FILTER_FWD,
1603 				    AMT_ACT_STATUS_FWD_NEW,
1604 				    v6);
1605 		/* Update IS_IN (A) as FWD/NEW */
1606 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1607 				    AMT_FILTER_NONE_NEW,
1608 				    AMT_ACT_STATUS_FWD_NEW,
1609 				    v6);
1610 		/* Update EXCLUDE (, Y-A) as D_FWD_NEW */
1611 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB,
1612 				    AMT_FILTER_D_FWD,
1613 				    AMT_ACT_STATUS_D_FWD_NEW,
1614 				    v6);
1615 	}
1616 }
1617 
1618 static void amt_mcast_is_ex_handler(struct amt_dev *amt,
1619 				    struct amt_tunnel_list *tunnel,
1620 				    struct amt_group_node *gnode,
1621 				    void *grec, void *zero_grec, bool v6)
1622 {
1623 	if (gnode->filter_mode == MCAST_INCLUDE) {
1624 /* Router State   Report Rec'd  New Router State         Actions
1625  * ------------   ------------  ----------------         -------
1626  * INCLUDE (A)    IS_EX (B)     EXCLUDE (A*B,B-A)        (B-A)=0
1627  *                                                       Delete (A-B)
1628  *                                                       Group Timer=GMI
1629  */
1630 		/* EXCLUDE(A*B, ) */
1631 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1632 				    AMT_FILTER_FWD,
1633 				    AMT_ACT_STATUS_FWD_NEW,
1634 				    v6);
1635 		/* EXCLUDE(, B-A) */
1636 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1637 				    AMT_FILTER_FWD,
1638 				    AMT_ACT_STATUS_D_FWD_NEW,
1639 				    v6);
1640 		/* (B-A)=0 */
1641 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1642 				    AMT_FILTER_D_FWD_NEW,
1643 				    AMT_ACT_GMI_ZERO,
1644 				    v6);
1645 		/* Group Timer=GMI */
1646 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1647 				      msecs_to_jiffies(amt_gmi(amt))))
1648 			dev_hold(amt->dev);
1649 		gnode->filter_mode = MCAST_EXCLUDE;
1650 		/* Delete (A-B) will be worked by amt_cleanup_srcs(). */
1651 	} else {
1652 /* Router State   Report Rec'd  New Router State	Actions
1653  * ------------   ------------  ----------------	-------
1654  * EXCLUDE (X,Y)  IS_EX (A)     EXCLUDE (A-Y,Y*A)	(A-X-Y)=GMI
1655  *							Delete (X-A)
1656  *							Delete (Y-A)
1657  *							Group Timer=GMI
1658  */
1659 		/* EXCLUDE (A-Y, ) */
1660 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1661 				    AMT_FILTER_D_FWD,
1662 				    AMT_ACT_STATUS_FWD_NEW,
1663 				    v6);
1664 		/* EXCLUDE (, Y*A ) */
1665 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1666 				    AMT_FILTER_D_FWD,
1667 				    AMT_ACT_STATUS_D_FWD_NEW,
1668 				    v6);
1669 		/* (A-X-Y)=GMI */
1670 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1671 				    AMT_FILTER_BOTH_NEW,
1672 				    AMT_ACT_GMI,
1673 				    v6);
1674 		/* Group Timer=GMI */
1675 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1676 				      msecs_to_jiffies(amt_gmi(amt))))
1677 			dev_hold(amt->dev);
1678 		/* Delete (X-A), (Y-A) will be worked by amt_cleanup_srcs(). */
1679 	}
1680 }
1681 
1682 static void amt_mcast_to_in_handler(struct amt_dev *amt,
1683 				    struct amt_tunnel_list *tunnel,
1684 				    struct amt_group_node *gnode,
1685 				    void *grec, void *zero_grec, bool v6)
1686 {
1687 	if (gnode->filter_mode == MCAST_INCLUDE) {
1688 /* Router State   Report Rec'd New Router State        Actions
1689  * ------------   ------------ ----------------        -------
1690  * INCLUDE (A)    TO_IN (B)    INCLUDE (A+B)           (B)=GMI
1691  *						       Send Q(G,A-B)
1692  */
1693 		/* Update TO_IN (B) sources as FWD/NEW */
1694 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1695 				    AMT_FILTER_NONE_NEW,
1696 				    AMT_ACT_STATUS_FWD_NEW,
1697 				    v6);
1698 		/* Update INCLUDE (A) sources as NEW */
1699 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1700 				    AMT_FILTER_FWD,
1701 				    AMT_ACT_STATUS_FWD_NEW,
1702 				    v6);
1703 		/* (B)=GMI */
1704 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1705 				    AMT_FILTER_FWD_NEW,
1706 				    AMT_ACT_GMI,
1707 				    v6);
1708 	} else {
1709 /* Router State   Report Rec'd New Router State        Actions
1710  * ------------   ------------ ----------------        -------
1711  * EXCLUDE (X,Y)  TO_IN (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1712  *						       Send Q(G,X-A)
1713  *						       Send Q(G)
1714  */
1715 		/* Update TO_IN (A) sources as FWD/NEW */
1716 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1717 				    AMT_FILTER_NONE_NEW,
1718 				    AMT_ACT_STATUS_FWD_NEW,
1719 				    v6);
1720 		/* Update EXCLUDE(X,) sources as FWD/NEW */
1721 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1722 				    AMT_FILTER_FWD,
1723 				    AMT_ACT_STATUS_FWD_NEW,
1724 				    v6);
1725 		/* EXCLUDE (, Y-A)
1726 		 * (A) are already switched to FWD_NEW.
1727 		 * So, D_FWD/OLD -> D_FWD/NEW is okay.
1728 		 */
1729 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1730 				    AMT_FILTER_D_FWD,
1731 				    AMT_ACT_STATUS_D_FWD_NEW,
1732 				    v6);
1733 		/* (A)=GMI
1734 		 * Only FWD_NEW will have (A) sources.
1735 		 */
1736 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1737 				    AMT_FILTER_FWD_NEW,
1738 				    AMT_ACT_GMI,
1739 				    v6);
1740 	}
1741 }
1742 
1743 static void amt_mcast_to_ex_handler(struct amt_dev *amt,
1744 				    struct amt_tunnel_list *tunnel,
1745 				    struct amt_group_node *gnode,
1746 				    void *grec, void *zero_grec, bool v6)
1747 {
1748 	if (gnode->filter_mode == MCAST_INCLUDE) {
1749 /* Router State   Report Rec'd New Router State        Actions
1750  * ------------   ------------ ----------------        -------
1751  * INCLUDE (A)    TO_EX (B)    EXCLUDE (A*B,B-A)       (B-A)=0
1752  *						       Delete (A-B)
1753  *						       Send Q(G,A*B)
1754  *						       Group Timer=GMI
1755  */
1756 		/* EXCLUDE (A*B, ) */
1757 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1758 				    AMT_FILTER_FWD,
1759 				    AMT_ACT_STATUS_FWD_NEW,
1760 				    v6);
1761 		/* EXCLUDE (, B-A) */
1762 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1763 				    AMT_FILTER_FWD,
1764 				    AMT_ACT_STATUS_D_FWD_NEW,
1765 				    v6);
1766 		/* (B-A)=0 */
1767 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1768 				    AMT_FILTER_D_FWD_NEW,
1769 				    AMT_ACT_GMI_ZERO,
1770 				    v6);
1771 		/* Group Timer=GMI */
1772 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1773 				      msecs_to_jiffies(amt_gmi(amt))))
1774 			dev_hold(amt->dev);
1775 		gnode->filter_mode = MCAST_EXCLUDE;
1776 		/* Delete (A-B) will be worked by amt_cleanup_srcs(). */
1777 	} else {
1778 /* Router State   Report Rec'd New Router State        Actions
1779  * ------------   ------------ ----------------        -------
1780  * EXCLUDE (X,Y)  TO_EX (A)    EXCLUDE (A-Y,Y*A)       (A-X-Y)=Group Timer
1781  *						       Delete (X-A)
1782  *						       Delete (Y-A)
1783  *						       Send Q(G,A-Y)
1784  *						       Group Timer=GMI
1785  */
1786 		/* Update (A-X-Y) as NONE/OLD */
1787 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1788 				    AMT_FILTER_BOTH,
1789 				    AMT_ACT_GT,
1790 				    v6);
1791 		/* EXCLUDE (A-Y, ) */
1792 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1793 				    AMT_FILTER_D_FWD,
1794 				    AMT_ACT_STATUS_FWD_NEW,
1795 				    v6);
1796 		/* EXCLUDE (, Y*A) */
1797 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1798 				    AMT_FILTER_D_FWD,
1799 				    AMT_ACT_STATUS_D_FWD_NEW,
1800 				    v6);
1801 		/* Group Timer=GMI */
1802 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1803 				      msecs_to_jiffies(amt_gmi(amt))))
1804 			dev_hold(amt->dev);
1805 		/* Delete (X-A), (Y-A) will be worked by amt_cleanup_srcs(). */
1806 	}
1807 }
1808 
1809 static void amt_mcast_allow_handler(struct amt_dev *amt,
1810 				    struct amt_tunnel_list *tunnel,
1811 				    struct amt_group_node *gnode,
1812 				    void *grec, void *zero_grec, bool v6)
1813 {
1814 	if (gnode->filter_mode == MCAST_INCLUDE) {
1815 /* Router State   Report Rec'd New Router State        Actions
1816  * ------------   ------------ ----------------        -------
1817  * INCLUDE (A)    ALLOW (B)    INCLUDE (A+B)	       (B)=GMI
1818  */
1819 		/* INCLUDE (A+B) */
1820 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1821 				    AMT_FILTER_FWD,
1822 				    AMT_ACT_STATUS_FWD_NEW,
1823 				    v6);
1824 		/* (B)=GMI */
1825 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1826 				    AMT_FILTER_FWD_NEW,
1827 				    AMT_ACT_GMI,
1828 				    v6);
1829 	} else {
1830 /* Router State   Report Rec'd New Router State        Actions
1831  * ------------   ------------ ----------------        -------
1832  * EXCLUDE (X,Y)  ALLOW (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1833  */
1834 		/* EXCLUDE (X+A, ) */
1835 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1836 				    AMT_FILTER_FWD,
1837 				    AMT_ACT_STATUS_FWD_NEW,
1838 				    v6);
1839 		/* EXCLUDE (, Y-A) */
1840 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB,
1841 				    AMT_FILTER_D_FWD,
1842 				    AMT_ACT_STATUS_D_FWD_NEW,
1843 				    v6);
1844 		/* (A)=GMI
1845 		 * All (A) source are now FWD/NEW status.
1846 		 */
1847 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1848 				    AMT_FILTER_FWD_NEW,
1849 				    AMT_ACT_GMI,
1850 				    v6);
1851 	}
1852 }
1853 
1854 static void amt_mcast_block_handler(struct amt_dev *amt,
1855 				    struct amt_tunnel_list *tunnel,
1856 				    struct amt_group_node *gnode,
1857 				    void *grec, void *zero_grec, bool v6)
1858 {
1859 	if (gnode->filter_mode == MCAST_INCLUDE) {
1860 /* Router State   Report Rec'd New Router State        Actions
1861  * ------------   ------------ ----------------        -------
1862  * INCLUDE (A)    BLOCK (B)    INCLUDE (A)             Send Q(G,A*B)
1863  */
1864 		/* INCLUDE (A) */
1865 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1866 				    AMT_FILTER_FWD,
1867 				    AMT_ACT_STATUS_FWD_NEW,
1868 				    v6);
1869 	} else {
1870 /* Router State   Report Rec'd New Router State        Actions
1871  * ------------   ------------ ----------------        -------
1872  * EXCLUDE (X,Y)  BLOCK (A)    EXCLUDE (X+(A-Y),Y)     (A-X-Y)=Group Timer
1873  *						       Send Q(G,A-Y)
1874  */
1875 		/* (A-X-Y)=Group Timer */
1876 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1877 				    AMT_FILTER_BOTH,
1878 				    AMT_ACT_GT,
1879 				    v6);
1880 		/* EXCLUDE (X, ) */
1881 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1882 				    AMT_FILTER_FWD,
1883 				    AMT_ACT_STATUS_FWD_NEW,
1884 				    v6);
1885 		/* EXCLUDE (X+(A-Y) */
1886 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1887 				    AMT_FILTER_D_FWD,
1888 				    AMT_ACT_STATUS_FWD_NEW,
1889 				    v6);
1890 		/* EXCLUDE (, Y) */
1891 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1892 				    AMT_FILTER_D_FWD,
1893 				    AMT_ACT_STATUS_D_FWD_NEW,
1894 				    v6);
1895 	}
1896 }
1897 
1898 /* RFC 3376
1899  * 7.3.2. In the Presence of Older Version Group Members
1900  *
1901  * When Group Compatibility Mode is IGMPv2, a router internally
1902  * translates the following IGMPv2 messages for that group to their
1903  * IGMPv3 equivalents:
1904  *
1905  * IGMPv2 Message                IGMPv3 Equivalent
1906  * --------------                -----------------
1907  * Report                        IS_EX( {} )
1908  * Leave                         TO_IN( {} )
1909  */
1910 static void amt_igmpv2_report_handler(struct amt_dev *amt, struct sk_buff *skb,
1911 				      struct amt_tunnel_list *tunnel)
1912 {
1913 	struct igmphdr *ih = igmp_hdr(skb);
1914 	struct iphdr *iph = ip_hdr(skb);
1915 	struct amt_group_node *gnode;
1916 	union amt_addr group, host;
1917 
1918 	memset(&group, 0, sizeof(union amt_addr));
1919 	group.ip4 = ih->group;
1920 	memset(&host, 0, sizeof(union amt_addr));
1921 	host.ip4 = iph->saddr;
1922 
1923 	gnode = amt_lookup_group(tunnel, &group, &host, false);
1924 	if (!gnode) {
1925 		gnode = amt_add_group(amt, tunnel, &group, &host, false);
1926 		if (!IS_ERR(gnode)) {
1927 			gnode->filter_mode = MCAST_EXCLUDE;
1928 			if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1929 					      msecs_to_jiffies(amt_gmi(amt))))
1930 				dev_hold(amt->dev);
1931 		}
1932 	}
1933 }
1934 
1935 /* RFC 3376
1936  * 7.3.2. In the Presence of Older Version Group Members
1937  *
1938  * When Group Compatibility Mode is IGMPv2, a router internally
1939  * translates the following IGMPv2 messages for that group to their
1940  * IGMPv3 equivalents:
1941  *
1942  * IGMPv2 Message                IGMPv3 Equivalent
1943  * --------------                -----------------
1944  * Report                        IS_EX( {} )
1945  * Leave                         TO_IN( {} )
1946  */
1947 static void amt_igmpv2_leave_handler(struct amt_dev *amt, struct sk_buff *skb,
1948 				     struct amt_tunnel_list *tunnel)
1949 {
1950 	struct igmphdr *ih = igmp_hdr(skb);
1951 	struct iphdr *iph = ip_hdr(skb);
1952 	struct amt_group_node *gnode;
1953 	union amt_addr group, host;
1954 
1955 	memset(&group, 0, sizeof(union amt_addr));
1956 	group.ip4 = ih->group;
1957 	memset(&host, 0, sizeof(union amt_addr));
1958 	host.ip4 = iph->saddr;
1959 
1960 	gnode = amt_lookup_group(tunnel, &group, &host, false);
1961 	if (gnode)
1962 		amt_del_group(amt, gnode);
1963 }
1964 
1965 static void amt_igmpv3_report_handler(struct amt_dev *amt, struct sk_buff *skb,
1966 				      struct amt_tunnel_list *tunnel)
1967 {
1968 	struct igmpv3_report *ihrv3 = igmpv3_report_hdr(skb);
1969 	int len = skb_transport_offset(skb) + sizeof(*ihrv3);
1970 	void *zero_grec = (void *)&igmpv3_zero_grec;
1971 	struct iphdr *iph = ip_hdr(skb);
1972 	struct amt_group_node *gnode;
1973 	union amt_addr group, host;
1974 	struct igmpv3_grec *grec;
1975 	u16 nsrcs;
1976 	int i;
1977 
1978 	for (i = 0; i < ntohs(ihrv3->ngrec); i++) {
1979 		len += sizeof(*grec);
1980 		if (!ip_mc_may_pull(skb, len))
1981 			break;
1982 
1983 		grec = (void *)(skb->data + len - sizeof(*grec));
1984 		nsrcs = ntohs(grec->grec_nsrcs);
1985 
1986 		len += nsrcs * sizeof(__be32);
1987 		if (!ip_mc_may_pull(skb, len))
1988 			break;
1989 
1990 		memset(&group, 0, sizeof(union amt_addr));
1991 		group.ip4 = grec->grec_mca;
1992 		memset(&host, 0, sizeof(union amt_addr));
1993 		host.ip4 = iph->saddr;
1994 		gnode = amt_lookup_group(tunnel, &group, &host, false);
1995 		if (!gnode) {
1996 			gnode = amt_add_group(amt, tunnel, &group, &host,
1997 					      false);
1998 			if (IS_ERR(gnode))
1999 				continue;
2000 		}
2001 
2002 		amt_add_srcs(amt, tunnel, gnode, grec, false);
2003 		switch (grec->grec_type) {
2004 		case IGMPV3_MODE_IS_INCLUDE:
2005 			amt_mcast_is_in_handler(amt, tunnel, gnode, grec,
2006 						zero_grec, false);
2007 			break;
2008 		case IGMPV3_MODE_IS_EXCLUDE:
2009 			amt_mcast_is_ex_handler(amt, tunnel, gnode, grec,
2010 						zero_grec, false);
2011 			break;
2012 		case IGMPV3_CHANGE_TO_INCLUDE:
2013 			amt_mcast_to_in_handler(amt, tunnel, gnode, grec,
2014 						zero_grec, false);
2015 			break;
2016 		case IGMPV3_CHANGE_TO_EXCLUDE:
2017 			amt_mcast_to_ex_handler(amt, tunnel, gnode, grec,
2018 						zero_grec, false);
2019 			break;
2020 		case IGMPV3_ALLOW_NEW_SOURCES:
2021 			amt_mcast_allow_handler(amt, tunnel, gnode, grec,
2022 						zero_grec, false);
2023 			break;
2024 		case IGMPV3_BLOCK_OLD_SOURCES:
2025 			amt_mcast_block_handler(amt, tunnel, gnode, grec,
2026 						zero_grec, false);
2027 			break;
2028 		default:
2029 			break;
2030 		}
2031 		amt_cleanup_srcs(amt, tunnel, gnode);
2032 	}
2033 }
2034 
2035 /* caller held tunnel->lock */
2036 static void amt_igmp_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2037 				    struct amt_tunnel_list *tunnel)
2038 {
2039 	struct igmphdr *ih = igmp_hdr(skb);
2040 
2041 	switch (ih->type) {
2042 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
2043 		amt_igmpv3_report_handler(amt, skb, tunnel);
2044 		break;
2045 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
2046 		amt_igmpv2_report_handler(amt, skb, tunnel);
2047 		break;
2048 	case IGMP_HOST_LEAVE_MESSAGE:
2049 		amt_igmpv2_leave_handler(amt, skb, tunnel);
2050 		break;
2051 	default:
2052 		break;
2053 	}
2054 }
2055 
2056 #if IS_ENABLED(CONFIG_IPV6)
2057 /* RFC 3810
2058  * 8.3.2. In the Presence of MLDv1 Multicast Address Listeners
2059  *
2060  * When Multicast Address Compatibility Mode is MLDv2, a router acts
2061  * using the MLDv2 protocol for that multicast address.  When Multicast
2062  * Address Compatibility Mode is MLDv1, a router internally translates
2063  * the following MLDv1 messages for that multicast address to their
2064  * MLDv2 equivalents:
2065  *
2066  * MLDv1 Message                 MLDv2 Equivalent
2067  * --------------                -----------------
2068  * Report                        IS_EX( {} )
2069  * Done                          TO_IN( {} )
2070  */
2071 static void amt_mldv1_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2072 				     struct amt_tunnel_list *tunnel)
2073 {
2074 	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2075 	struct ipv6hdr *ip6h = ipv6_hdr(skb);
2076 	struct amt_group_node *gnode;
2077 	union amt_addr group, host;
2078 
2079 	memcpy(&group.ip6, &mld->mld_mca, sizeof(struct in6_addr));
2080 	memcpy(&host.ip6, &ip6h->saddr, sizeof(struct in6_addr));
2081 
2082 	gnode = amt_lookup_group(tunnel, &group, &host, true);
2083 	if (!gnode) {
2084 		gnode = amt_add_group(amt, tunnel, &group, &host, true);
2085 		if (!IS_ERR(gnode)) {
2086 			gnode->filter_mode = MCAST_EXCLUDE;
2087 			if (!mod_delayed_work(amt_wq, &gnode->group_timer,
2088 					      msecs_to_jiffies(amt_gmi(amt))))
2089 				dev_hold(amt->dev);
2090 		}
2091 	}
2092 }
2093 
2094 /* RFC 3810
2095  * 8.3.2. In the Presence of MLDv1 Multicast Address Listeners
2096  *
2097  * When Multicast Address Compatibility Mode is MLDv2, a router acts
2098  * using the MLDv2 protocol for that multicast address.  When Multicast
2099  * Address Compatibility Mode is MLDv1, a router internally translates
2100  * the following MLDv1 messages for that multicast address to their
2101  * MLDv2 equivalents:
2102  *
2103  * MLDv1 Message                 MLDv2 Equivalent
2104  * --------------                -----------------
2105  * Report                        IS_EX( {} )
2106  * Done                          TO_IN( {} )
2107  */
2108 static void amt_mldv1_leave_handler(struct amt_dev *amt, struct sk_buff *skb,
2109 				    struct amt_tunnel_list *tunnel)
2110 {
2111 	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2112 	struct iphdr *iph = ip_hdr(skb);
2113 	struct amt_group_node *gnode;
2114 	union amt_addr group, host;
2115 
2116 	memcpy(&group.ip6, &mld->mld_mca, sizeof(struct in6_addr));
2117 	memset(&host, 0, sizeof(union amt_addr));
2118 	host.ip4 = iph->saddr;
2119 
2120 	gnode = amt_lookup_group(tunnel, &group, &host, true);
2121 	if (gnode) {
2122 		amt_del_group(amt, gnode);
2123 		return;
2124 	}
2125 }
2126 
2127 static void amt_mldv2_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2128 				     struct amt_tunnel_list *tunnel)
2129 {
2130 	struct mld2_report *mld2r = (struct mld2_report *)icmp6_hdr(skb);
2131 	int len = skb_transport_offset(skb) + sizeof(*mld2r);
2132 	void *zero_grec = (void *)&mldv2_zero_grec;
2133 	struct ipv6hdr *ip6h = ipv6_hdr(skb);
2134 	struct amt_group_node *gnode;
2135 	union amt_addr group, host;
2136 	struct mld2_grec *grec;
2137 	u16 nsrcs;
2138 	int i;
2139 
2140 	for (i = 0; i < ntohs(mld2r->mld2r_ngrec); i++) {
2141 		len += sizeof(*grec);
2142 		if (!ipv6_mc_may_pull(skb, len))
2143 			break;
2144 
2145 		grec = (void *)(skb->data + len - sizeof(*grec));
2146 		nsrcs = ntohs(grec->grec_nsrcs);
2147 
2148 		len += nsrcs * sizeof(struct in6_addr);
2149 		if (!ipv6_mc_may_pull(skb, len))
2150 			break;
2151 
2152 		memset(&group, 0, sizeof(union amt_addr));
2153 		group.ip6 = grec->grec_mca;
2154 		memset(&host, 0, sizeof(union amt_addr));
2155 		host.ip6 = ip6h->saddr;
2156 		gnode = amt_lookup_group(tunnel, &group, &host, true);
2157 		if (!gnode) {
2158 			gnode = amt_add_group(amt, tunnel, &group, &host,
2159 					      ETH_P_IPV6);
2160 			if (IS_ERR(gnode))
2161 				continue;
2162 		}
2163 
2164 		amt_add_srcs(amt, tunnel, gnode, grec, true);
2165 		switch (grec->grec_type) {
2166 		case MLD2_MODE_IS_INCLUDE:
2167 			amt_mcast_is_in_handler(amt, tunnel, gnode, grec,
2168 						zero_grec, true);
2169 			break;
2170 		case MLD2_MODE_IS_EXCLUDE:
2171 			amt_mcast_is_ex_handler(amt, tunnel, gnode, grec,
2172 						zero_grec, true);
2173 			break;
2174 		case MLD2_CHANGE_TO_INCLUDE:
2175 			amt_mcast_to_in_handler(amt, tunnel, gnode, grec,
2176 						zero_grec, true);
2177 			break;
2178 		case MLD2_CHANGE_TO_EXCLUDE:
2179 			amt_mcast_to_ex_handler(amt, tunnel, gnode, grec,
2180 						zero_grec, true);
2181 			break;
2182 		case MLD2_ALLOW_NEW_SOURCES:
2183 			amt_mcast_allow_handler(amt, tunnel, gnode, grec,
2184 						zero_grec, true);
2185 			break;
2186 		case MLD2_BLOCK_OLD_SOURCES:
2187 			amt_mcast_block_handler(amt, tunnel, gnode, grec,
2188 						zero_grec, true);
2189 			break;
2190 		default:
2191 			break;
2192 		}
2193 		amt_cleanup_srcs(amt, tunnel, gnode);
2194 	}
2195 }
2196 
2197 /* caller held tunnel->lock */
2198 static void amt_mld_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2199 				   struct amt_tunnel_list *tunnel)
2200 {
2201 	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2202 
2203 	switch (mld->mld_type) {
2204 	case ICMPV6_MGM_REPORT:
2205 		amt_mldv1_report_handler(amt, skb, tunnel);
2206 		break;
2207 	case ICMPV6_MLD2_REPORT:
2208 		amt_mldv2_report_handler(amt, skb, tunnel);
2209 		break;
2210 	case ICMPV6_MGM_REDUCTION:
2211 		amt_mldv1_leave_handler(amt, skb, tunnel);
2212 		break;
2213 	default:
2214 		break;
2215 	}
2216 }
2217 #endif
2218 
2219 static bool amt_advertisement_handler(struct amt_dev *amt, struct sk_buff *skb)
2220 {
2221 	struct amt_header_advertisement *amta;
2222 	int hdr_size;
2223 
2224 	hdr_size = sizeof(*amta) + sizeof(struct udphdr);
2225 	if (!pskb_may_pull(skb, hdr_size))
2226 		return true;
2227 
2228 	amta = (struct amt_header_advertisement *)(udp_hdr(skb) + 1);
2229 	if (!amta->ip4)
2230 		return true;
2231 
2232 	if (amta->reserved || amta->version)
2233 		return true;
2234 
2235 	if (ipv4_is_loopback(amta->ip4) || ipv4_is_multicast(amta->ip4) ||
2236 	    ipv4_is_zeronet(amta->ip4))
2237 		return true;
2238 
2239 	amt->remote_ip = amta->ip4;
2240 	netdev_dbg(amt->dev, "advertised remote ip = %pI4\n", &amt->remote_ip);
2241 	mod_delayed_work(amt_wq, &amt->req_wq, 0);
2242 
2243 	amt_update_gw_status(amt, AMT_STATUS_RECEIVED_ADVERTISEMENT, true);
2244 	return false;
2245 }
2246 
2247 static bool amt_multicast_data_handler(struct amt_dev *amt, struct sk_buff *skb)
2248 {
2249 	struct amt_header_mcast_data *amtmd;
2250 	int hdr_size, len, err;
2251 	struct ethhdr *eth;
2252 	struct iphdr *iph;
2253 
2254 	hdr_size = sizeof(*amtmd) + sizeof(struct udphdr);
2255 	if (!pskb_may_pull(skb, hdr_size))
2256 		return true;
2257 
2258 	amtmd = (struct amt_header_mcast_data *)(udp_hdr(skb) + 1);
2259 	if (amtmd->reserved || amtmd->version)
2260 		return true;
2261 
2262 	if (iptunnel_pull_header(skb, hdr_size, htons(ETH_P_IP), false))
2263 		return true;
2264 
2265 	skb_reset_network_header(skb);
2266 	skb_push(skb, sizeof(*eth));
2267 	skb_reset_mac_header(skb);
2268 	skb_pull(skb, sizeof(*eth));
2269 	eth = eth_hdr(skb);
2270 
2271 	if (!pskb_may_pull(skb, sizeof(*iph)))
2272 		return true;
2273 	iph = ip_hdr(skb);
2274 
2275 	if (iph->version == 4) {
2276 		if (!ipv4_is_multicast(iph->daddr))
2277 			return true;
2278 		skb->protocol = htons(ETH_P_IP);
2279 		eth->h_proto = htons(ETH_P_IP);
2280 		ip_eth_mc_map(iph->daddr, eth->h_dest);
2281 #if IS_ENABLED(CONFIG_IPV6)
2282 	} else if (iph->version == 6) {
2283 		struct ipv6hdr *ip6h;
2284 
2285 		if (!pskb_may_pull(skb, sizeof(*ip6h)))
2286 			return true;
2287 
2288 		ip6h = ipv6_hdr(skb);
2289 		if (!ipv6_addr_is_multicast(&ip6h->daddr))
2290 			return true;
2291 		skb->protocol = htons(ETH_P_IPV6);
2292 		eth->h_proto = htons(ETH_P_IPV6);
2293 		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2294 #endif
2295 	} else {
2296 		return true;
2297 	}
2298 
2299 	skb->pkt_type = PACKET_MULTICAST;
2300 	skb->ip_summed = CHECKSUM_NONE;
2301 	len = skb->len;
2302 	err = gro_cells_receive(&amt->gro_cells, skb);
2303 	if (likely(err == NET_RX_SUCCESS))
2304 		dev_sw_netstats_rx_add(amt->dev, len);
2305 	else
2306 		amt->dev->stats.rx_dropped++;
2307 
2308 	return false;
2309 }
2310 
2311 static bool amt_membership_query_handler(struct amt_dev *amt,
2312 					 struct sk_buff *skb)
2313 {
2314 	struct amt_header_membership_query *amtmq;
2315 	struct igmpv3_query *ihv3;
2316 	struct ethhdr *eth, *oeth;
2317 	struct iphdr *iph;
2318 	int hdr_size, len;
2319 
2320 	hdr_size = sizeof(*amtmq) + sizeof(struct udphdr);
2321 	if (!pskb_may_pull(skb, hdr_size))
2322 		return true;
2323 
2324 	amtmq = (struct amt_header_membership_query *)(udp_hdr(skb) + 1);
2325 	if (amtmq->reserved || amtmq->version)
2326 		return true;
2327 
2328 	hdr_size -= sizeof(*eth);
2329 	if (iptunnel_pull_header(skb, hdr_size, htons(ETH_P_TEB), false))
2330 		return true;
2331 
2332 	oeth = eth_hdr(skb);
2333 	skb_reset_mac_header(skb);
2334 	skb_pull(skb, sizeof(*eth));
2335 	skb_reset_network_header(skb);
2336 	eth = eth_hdr(skb);
2337 	if (!pskb_may_pull(skb, sizeof(*iph)))
2338 		return true;
2339 
2340 	iph = ip_hdr(skb);
2341 	if (iph->version == 4) {
2342 		if (!pskb_may_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS +
2343 				   sizeof(*ihv3)))
2344 			return true;
2345 
2346 		if (!ipv4_is_multicast(iph->daddr))
2347 			return true;
2348 
2349 		ihv3 = skb_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
2350 		skb_reset_transport_header(skb);
2351 		skb_push(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
2352 		spin_lock_bh(&amt->lock);
2353 		amt->ready4 = true;
2354 		amt->mac = amtmq->response_mac;
2355 		amt->req_cnt = 0;
2356 		amt->qi = ihv3->qqic;
2357 		spin_unlock_bh(&amt->lock);
2358 		skb->protocol = htons(ETH_P_IP);
2359 		eth->h_proto = htons(ETH_P_IP);
2360 		ip_eth_mc_map(iph->daddr, eth->h_dest);
2361 #if IS_ENABLED(CONFIG_IPV6)
2362 	} else if (iph->version == 6) {
2363 		struct mld2_query *mld2q;
2364 		struct ipv6hdr *ip6h;
2365 
2366 		if (!pskb_may_pull(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS +
2367 				   sizeof(*mld2q)))
2368 			return true;
2369 
2370 		ip6h = ipv6_hdr(skb);
2371 		if (!ipv6_addr_is_multicast(&ip6h->daddr))
2372 			return true;
2373 
2374 		mld2q = skb_pull(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS);
2375 		skb_reset_transport_header(skb);
2376 		skb_push(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS);
2377 		spin_lock_bh(&amt->lock);
2378 		amt->ready6 = true;
2379 		amt->mac = amtmq->response_mac;
2380 		amt->req_cnt = 0;
2381 		amt->qi = mld2q->mld2q_qqic;
2382 		spin_unlock_bh(&amt->lock);
2383 		skb->protocol = htons(ETH_P_IPV6);
2384 		eth->h_proto = htons(ETH_P_IPV6);
2385 		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2386 #endif
2387 	} else {
2388 		return true;
2389 	}
2390 
2391 	ether_addr_copy(eth->h_source, oeth->h_source);
2392 	skb->pkt_type = PACKET_MULTICAST;
2393 	skb->ip_summed = CHECKSUM_NONE;
2394 	len = skb->len;
2395 	if (__netif_rx(skb) == NET_RX_SUCCESS) {
2396 		amt_update_gw_status(amt, AMT_STATUS_RECEIVED_QUERY, true);
2397 		dev_sw_netstats_rx_add(amt->dev, len);
2398 	} else {
2399 		amt->dev->stats.rx_dropped++;
2400 	}
2401 
2402 	return false;
2403 }
2404 
2405 static bool amt_update_handler(struct amt_dev *amt, struct sk_buff *skb)
2406 {
2407 	struct amt_header_membership_update *amtmu;
2408 	struct amt_tunnel_list *tunnel;
2409 	struct ethhdr *eth;
2410 	struct iphdr *iph;
2411 	int len, hdr_size;
2412 
2413 	iph = ip_hdr(skb);
2414 
2415 	hdr_size = sizeof(*amtmu) + sizeof(struct udphdr);
2416 	if (!pskb_may_pull(skb, hdr_size))
2417 		return true;
2418 
2419 	amtmu = (struct amt_header_membership_update *)(udp_hdr(skb) + 1);
2420 	if (amtmu->reserved || amtmu->version)
2421 		return true;
2422 
2423 	if (iptunnel_pull_header(skb, hdr_size, skb->protocol, false))
2424 		return true;
2425 
2426 	skb_reset_network_header(skb);
2427 
2428 	list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list) {
2429 		if (tunnel->ip4 == iph->saddr) {
2430 			if ((amtmu->nonce == tunnel->nonce &&
2431 			     amtmu->response_mac == tunnel->mac)) {
2432 				mod_delayed_work(amt_wq, &tunnel->gc_wq,
2433 						 msecs_to_jiffies(amt_gmi(amt))
2434 								  * 3);
2435 				goto report;
2436 			} else {
2437 				netdev_dbg(amt->dev, "Invalid MAC\n");
2438 				return true;
2439 			}
2440 		}
2441 	}
2442 
2443 	return true;
2444 
2445 report:
2446 	if (!pskb_may_pull(skb, sizeof(*iph)))
2447 		return true;
2448 
2449 	iph = ip_hdr(skb);
2450 	if (iph->version == 4) {
2451 		if (ip_mc_check_igmp(skb)) {
2452 			netdev_dbg(amt->dev, "Invalid IGMP\n");
2453 			return true;
2454 		}
2455 
2456 		spin_lock_bh(&tunnel->lock);
2457 		amt_igmp_report_handler(amt, skb, tunnel);
2458 		spin_unlock_bh(&tunnel->lock);
2459 
2460 		skb_push(skb, sizeof(struct ethhdr));
2461 		skb_reset_mac_header(skb);
2462 		eth = eth_hdr(skb);
2463 		skb->protocol = htons(ETH_P_IP);
2464 		eth->h_proto = htons(ETH_P_IP);
2465 		ip_eth_mc_map(iph->daddr, eth->h_dest);
2466 #if IS_ENABLED(CONFIG_IPV6)
2467 	} else if (iph->version == 6) {
2468 		struct ipv6hdr *ip6h = ipv6_hdr(skb);
2469 
2470 		if (ipv6_mc_check_mld(skb)) {
2471 			netdev_dbg(amt->dev, "Invalid MLD\n");
2472 			return true;
2473 		}
2474 
2475 		spin_lock_bh(&tunnel->lock);
2476 		amt_mld_report_handler(amt, skb, tunnel);
2477 		spin_unlock_bh(&tunnel->lock);
2478 
2479 		skb_push(skb, sizeof(struct ethhdr));
2480 		skb_reset_mac_header(skb);
2481 		eth = eth_hdr(skb);
2482 		skb->protocol = htons(ETH_P_IPV6);
2483 		eth->h_proto = htons(ETH_P_IPV6);
2484 		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2485 #endif
2486 	} else {
2487 		netdev_dbg(amt->dev, "Unsupported Protocol\n");
2488 		return true;
2489 	}
2490 
2491 	skb_pull(skb, sizeof(struct ethhdr));
2492 	skb->pkt_type = PACKET_MULTICAST;
2493 	skb->ip_summed = CHECKSUM_NONE;
2494 	len = skb->len;
2495 	if (__netif_rx(skb) == NET_RX_SUCCESS) {
2496 		amt_update_relay_status(tunnel, AMT_STATUS_RECEIVED_UPDATE,
2497 					true);
2498 		dev_sw_netstats_rx_add(amt->dev, len);
2499 	} else {
2500 		amt->dev->stats.rx_dropped++;
2501 	}
2502 
2503 	return false;
2504 }
2505 
2506 static void amt_send_advertisement(struct amt_dev *amt, __be32 nonce,
2507 				   __be32 daddr, __be16 dport)
2508 {
2509 	struct amt_header_advertisement *amta;
2510 	int hlen, tlen, offset;
2511 	struct socket *sock;
2512 	struct udphdr *udph;
2513 	struct sk_buff *skb;
2514 	struct iphdr *iph;
2515 	struct rtable *rt;
2516 	struct flowi4 fl4;
2517 	u32 len;
2518 	int err;
2519 
2520 	rcu_read_lock();
2521 	sock = rcu_dereference(amt->sock);
2522 	if (!sock)
2523 		goto out;
2524 
2525 	if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
2526 		goto out;
2527 
2528 	rt = ip_route_output_ports(amt->net, &fl4, sock->sk,
2529 				   daddr, amt->local_ip,
2530 				   dport, amt->relay_port,
2531 				   IPPROTO_UDP, 0,
2532 				   amt->stream_dev->ifindex);
2533 	if (IS_ERR(rt)) {
2534 		amt->dev->stats.tx_errors++;
2535 		goto out;
2536 	}
2537 
2538 	hlen = LL_RESERVED_SPACE(amt->dev);
2539 	tlen = amt->dev->needed_tailroom;
2540 	len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amta);
2541 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
2542 	if (!skb) {
2543 		ip_rt_put(rt);
2544 		amt->dev->stats.tx_errors++;
2545 		goto out;
2546 	}
2547 
2548 	skb->priority = TC_PRIO_CONTROL;
2549 	skb_dst_set(skb, &rt->dst);
2550 
2551 	len = sizeof(*iph) + sizeof(*udph) + sizeof(*amta);
2552 	skb_reset_network_header(skb);
2553 	skb_put(skb, len);
2554 	amta = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
2555 	amta->version	= 0;
2556 	amta->type	= AMT_MSG_ADVERTISEMENT;
2557 	amta->reserved	= 0;
2558 	amta->nonce	= nonce;
2559 	amta->ip4	= amt->local_ip;
2560 	skb_push(skb, sizeof(*udph));
2561 	skb_reset_transport_header(skb);
2562 	udph		= udp_hdr(skb);
2563 	udph->source	= amt->relay_port;
2564 	udph->dest	= dport;
2565 	udph->len	= htons(sizeof(*amta) + sizeof(*udph));
2566 	udph->check	= 0;
2567 	offset = skb_transport_offset(skb);
2568 	skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
2569 	udph->check = csum_tcpudp_magic(amt->local_ip, daddr,
2570 					sizeof(*udph) + sizeof(*amta),
2571 					IPPROTO_UDP, skb->csum);
2572 
2573 	skb_push(skb, sizeof(*iph));
2574 	iph		= ip_hdr(skb);
2575 	iph->version	= 4;
2576 	iph->ihl	= (sizeof(struct iphdr)) >> 2;
2577 	iph->tos	= AMT_TOS;
2578 	iph->frag_off	= 0;
2579 	iph->ttl	= ip4_dst_hoplimit(&rt->dst);
2580 	iph->daddr	= daddr;
2581 	iph->saddr	= amt->local_ip;
2582 	iph->protocol	= IPPROTO_UDP;
2583 	iph->tot_len	= htons(len);
2584 
2585 	skb->ip_summed = CHECKSUM_NONE;
2586 	ip_select_ident(amt->net, skb, NULL);
2587 	ip_send_check(iph);
2588 	err = ip_local_out(amt->net, sock->sk, skb);
2589 	if (unlikely(net_xmit_eval(err)))
2590 		amt->dev->stats.tx_errors++;
2591 
2592 out:
2593 	rcu_read_unlock();
2594 }
2595 
2596 static bool amt_discovery_handler(struct amt_dev *amt, struct sk_buff *skb)
2597 {
2598 	struct amt_header_discovery *amtd;
2599 	struct udphdr *udph;
2600 	struct iphdr *iph;
2601 
2602 	if (!pskb_may_pull(skb, sizeof(*udph) + sizeof(*amtd)))
2603 		return true;
2604 
2605 	iph = ip_hdr(skb);
2606 	udph = udp_hdr(skb);
2607 	amtd = (struct amt_header_discovery *)(udp_hdr(skb) + 1);
2608 
2609 	if (amtd->reserved || amtd->version)
2610 		return true;
2611 
2612 	amt_send_advertisement(amt, amtd->nonce, iph->saddr, udph->source);
2613 
2614 	return false;
2615 }
2616 
2617 static bool amt_request_handler(struct amt_dev *amt, struct sk_buff *skb)
2618 {
2619 	struct amt_header_request *amtrh;
2620 	struct amt_tunnel_list *tunnel;
2621 	unsigned long long key;
2622 	struct udphdr *udph;
2623 	struct iphdr *iph;
2624 	u64 mac;
2625 	int i;
2626 
2627 	if (!pskb_may_pull(skb, sizeof(*udph) + sizeof(*amtrh)))
2628 		return true;
2629 
2630 	iph = ip_hdr(skb);
2631 	udph = udp_hdr(skb);
2632 	amtrh = (struct amt_header_request *)(udp_hdr(skb) + 1);
2633 
2634 	if (amtrh->reserved1 || amtrh->reserved2 || amtrh->version)
2635 		return true;
2636 
2637 	list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list)
2638 		if (tunnel->ip4 == iph->saddr)
2639 			goto send;
2640 
2641 	if (amt->nr_tunnels >= amt->max_tunnels) {
2642 		icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
2643 		return true;
2644 	}
2645 
2646 	tunnel = kzalloc(sizeof(*tunnel) +
2647 			 (sizeof(struct hlist_head) * amt->hash_buckets),
2648 			 GFP_ATOMIC);
2649 	if (!tunnel)
2650 		return true;
2651 
2652 	tunnel->source_port = udph->source;
2653 	tunnel->ip4 = iph->saddr;
2654 
2655 	memcpy(&key, &tunnel->key, sizeof(unsigned long long));
2656 	tunnel->amt = amt;
2657 	spin_lock_init(&tunnel->lock);
2658 	for (i = 0; i < amt->hash_buckets; i++)
2659 		INIT_HLIST_HEAD(&tunnel->groups[i]);
2660 
2661 	INIT_DELAYED_WORK(&tunnel->gc_wq, amt_tunnel_expire);
2662 
2663 	spin_lock_bh(&amt->lock);
2664 	list_add_tail_rcu(&tunnel->list, &amt->tunnel_list);
2665 	tunnel->key = amt->key;
2666 	amt_update_relay_status(tunnel, AMT_STATUS_RECEIVED_REQUEST, true);
2667 	amt->nr_tunnels++;
2668 	mod_delayed_work(amt_wq, &tunnel->gc_wq,
2669 			 msecs_to_jiffies(amt_gmi(amt)));
2670 	spin_unlock_bh(&amt->lock);
2671 
2672 send:
2673 	tunnel->nonce = amtrh->nonce;
2674 	mac = siphash_3u32((__force u32)tunnel->ip4,
2675 			   (__force u32)tunnel->source_port,
2676 			   (__force u32)tunnel->nonce,
2677 			   &tunnel->key);
2678 	tunnel->mac = mac >> 16;
2679 
2680 	if (!netif_running(amt->dev) || !netif_running(amt->stream_dev))
2681 		return true;
2682 
2683 	if (!amtrh->p)
2684 		amt_send_igmp_gq(amt, tunnel);
2685 	else
2686 		amt_send_mld_gq(amt, tunnel);
2687 
2688 	return false;
2689 }
2690 
2691 static int amt_rcv(struct sock *sk, struct sk_buff *skb)
2692 {
2693 	struct amt_dev *amt;
2694 	struct iphdr *iph;
2695 	int type;
2696 	bool err;
2697 
2698 	rcu_read_lock_bh();
2699 	amt = rcu_dereference_sk_user_data(sk);
2700 	if (!amt) {
2701 		err = true;
2702 		kfree_skb(skb);
2703 		goto out;
2704 	}
2705 
2706 	skb->dev = amt->dev;
2707 	iph = ip_hdr(skb);
2708 	type = amt_parse_type(skb);
2709 	if (type == -1) {
2710 		err = true;
2711 		goto drop;
2712 	}
2713 
2714 	if (amt->mode == AMT_MODE_GATEWAY) {
2715 		switch (type) {
2716 		case AMT_MSG_ADVERTISEMENT:
2717 			if (iph->saddr != amt->discovery_ip) {
2718 				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2719 				err = true;
2720 				goto drop;
2721 			}
2722 			err = amt_advertisement_handler(amt, skb);
2723 			break;
2724 		case AMT_MSG_MULTICAST_DATA:
2725 			if (iph->saddr != amt->remote_ip) {
2726 				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2727 				err = true;
2728 				goto drop;
2729 			}
2730 			err = amt_multicast_data_handler(amt, skb);
2731 			if (err)
2732 				goto drop;
2733 			else
2734 				goto out;
2735 		case AMT_MSG_MEMBERSHIP_QUERY:
2736 			if (iph->saddr != amt->remote_ip) {
2737 				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2738 				err = true;
2739 				goto drop;
2740 			}
2741 			err = amt_membership_query_handler(amt, skb);
2742 			if (err)
2743 				goto drop;
2744 			else
2745 				goto out;
2746 		default:
2747 			err = true;
2748 			netdev_dbg(amt->dev, "Invalid type of Gateway\n");
2749 			break;
2750 		}
2751 	} else {
2752 		switch (type) {
2753 		case AMT_MSG_DISCOVERY:
2754 			err = amt_discovery_handler(amt, skb);
2755 			break;
2756 		case AMT_MSG_REQUEST:
2757 			err = amt_request_handler(amt, skb);
2758 			break;
2759 		case AMT_MSG_MEMBERSHIP_UPDATE:
2760 			err = amt_update_handler(amt, skb);
2761 			if (err)
2762 				goto drop;
2763 			else
2764 				goto out;
2765 		default:
2766 			err = true;
2767 			netdev_dbg(amt->dev, "Invalid type of relay\n");
2768 			break;
2769 		}
2770 	}
2771 drop:
2772 	if (err) {
2773 		amt->dev->stats.rx_dropped++;
2774 		kfree_skb(skb);
2775 	} else {
2776 		consume_skb(skb);
2777 	}
2778 out:
2779 	rcu_read_unlock_bh();
2780 	return 0;
2781 }
2782 
2783 static int amt_err_lookup(struct sock *sk, struct sk_buff *skb)
2784 {
2785 	struct amt_dev *amt;
2786 	int type;
2787 
2788 	rcu_read_lock_bh();
2789 	amt = rcu_dereference_sk_user_data(sk);
2790 	if (!amt)
2791 		goto out;
2792 
2793 	if (amt->mode != AMT_MODE_GATEWAY)
2794 		goto drop;
2795 
2796 	type = amt_parse_type(skb);
2797 	if (type == -1)
2798 		goto drop;
2799 
2800 	netdev_dbg(amt->dev, "Received IGMP Unreachable of %s\n",
2801 		   type_str[type]);
2802 	switch (type) {
2803 	case AMT_MSG_DISCOVERY:
2804 		break;
2805 	case AMT_MSG_REQUEST:
2806 	case AMT_MSG_MEMBERSHIP_UPDATE:
2807 		if (amt->status >= AMT_STATUS_RECEIVED_ADVERTISEMENT)
2808 			mod_delayed_work(amt_wq, &amt->req_wq, 0);
2809 		break;
2810 	default:
2811 		goto drop;
2812 	}
2813 out:
2814 	rcu_read_unlock_bh();
2815 	return 0;
2816 drop:
2817 	rcu_read_unlock_bh();
2818 	amt->dev->stats.rx_dropped++;
2819 	return 0;
2820 }
2821 
2822 static struct socket *amt_create_sock(struct net *net, __be16 port)
2823 {
2824 	struct udp_port_cfg udp_conf;
2825 	struct socket *sock;
2826 	int err;
2827 
2828 	memset(&udp_conf, 0, sizeof(udp_conf));
2829 	udp_conf.family = AF_INET;
2830 	udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
2831 
2832 	udp_conf.local_udp_port = port;
2833 
2834 	err = udp_sock_create(net, &udp_conf, &sock);
2835 	if (err < 0)
2836 		return ERR_PTR(err);
2837 
2838 	return sock;
2839 }
2840 
2841 static int amt_socket_create(struct amt_dev *amt)
2842 {
2843 	struct udp_tunnel_sock_cfg tunnel_cfg;
2844 	struct socket *sock;
2845 
2846 	sock = amt_create_sock(amt->net, amt->relay_port);
2847 	if (IS_ERR(sock))
2848 		return PTR_ERR(sock);
2849 
2850 	/* Mark socket as an encapsulation socket */
2851 	memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
2852 	tunnel_cfg.sk_user_data = amt;
2853 	tunnel_cfg.encap_type = 1;
2854 	tunnel_cfg.encap_rcv = amt_rcv;
2855 	tunnel_cfg.encap_err_lookup = amt_err_lookup;
2856 	tunnel_cfg.encap_destroy = NULL;
2857 	setup_udp_tunnel_sock(amt->net, sock, &tunnel_cfg);
2858 
2859 	rcu_assign_pointer(amt->sock, sock);
2860 	return 0;
2861 }
2862 
2863 static int amt_dev_open(struct net_device *dev)
2864 {
2865 	struct amt_dev *amt = netdev_priv(dev);
2866 	int err;
2867 
2868 	amt->ready4 = false;
2869 	amt->ready6 = false;
2870 
2871 	err = amt_socket_create(amt);
2872 	if (err)
2873 		return err;
2874 
2875 	amt->req_cnt = 0;
2876 	amt->remote_ip = 0;
2877 	get_random_bytes(&amt->key, sizeof(siphash_key_t));
2878 
2879 	amt->status = AMT_STATUS_INIT;
2880 	if (amt->mode == AMT_MODE_GATEWAY) {
2881 		mod_delayed_work(amt_wq, &amt->discovery_wq, 0);
2882 		mod_delayed_work(amt_wq, &amt->req_wq, 0);
2883 	} else if (amt->mode == AMT_MODE_RELAY) {
2884 		mod_delayed_work(amt_wq, &amt->secret_wq,
2885 				 msecs_to_jiffies(AMT_SECRET_TIMEOUT));
2886 	}
2887 	return err;
2888 }
2889 
2890 static int amt_dev_stop(struct net_device *dev)
2891 {
2892 	struct amt_dev *amt = netdev_priv(dev);
2893 	struct amt_tunnel_list *tunnel, *tmp;
2894 	struct socket *sock;
2895 
2896 	cancel_delayed_work_sync(&amt->req_wq);
2897 	cancel_delayed_work_sync(&amt->discovery_wq);
2898 	cancel_delayed_work_sync(&amt->secret_wq);
2899 
2900 	/* shutdown */
2901 	sock = rtnl_dereference(amt->sock);
2902 	RCU_INIT_POINTER(amt->sock, NULL);
2903 	synchronize_net();
2904 	if (sock)
2905 		udp_tunnel_sock_release(sock);
2906 
2907 	amt->ready4 = false;
2908 	amt->ready6 = false;
2909 	amt->req_cnt = 0;
2910 	amt->remote_ip = 0;
2911 
2912 	list_for_each_entry_safe(tunnel, tmp, &amt->tunnel_list, list) {
2913 		list_del_rcu(&tunnel->list);
2914 		amt->nr_tunnels--;
2915 		cancel_delayed_work_sync(&tunnel->gc_wq);
2916 		amt_clear_groups(tunnel);
2917 		kfree_rcu(tunnel, rcu);
2918 	}
2919 
2920 	return 0;
2921 }
2922 
2923 static const struct device_type amt_type = {
2924 	.name = "amt",
2925 };
2926 
2927 static int amt_dev_init(struct net_device *dev)
2928 {
2929 	struct amt_dev *amt = netdev_priv(dev);
2930 	int err;
2931 
2932 	amt->dev = dev;
2933 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
2934 	if (!dev->tstats)
2935 		return -ENOMEM;
2936 
2937 	err = gro_cells_init(&amt->gro_cells, dev);
2938 	if (err) {
2939 		free_percpu(dev->tstats);
2940 		return err;
2941 	}
2942 
2943 	return 0;
2944 }
2945 
2946 static void amt_dev_uninit(struct net_device *dev)
2947 {
2948 	struct amt_dev *amt = netdev_priv(dev);
2949 
2950 	gro_cells_destroy(&amt->gro_cells);
2951 	free_percpu(dev->tstats);
2952 }
2953 
2954 static const struct net_device_ops amt_netdev_ops = {
2955 	.ndo_init               = amt_dev_init,
2956 	.ndo_uninit             = amt_dev_uninit,
2957 	.ndo_open		= amt_dev_open,
2958 	.ndo_stop		= amt_dev_stop,
2959 	.ndo_start_xmit         = amt_dev_xmit,
2960 	.ndo_get_stats64        = dev_get_tstats64,
2961 };
2962 
2963 static void amt_link_setup(struct net_device *dev)
2964 {
2965 	dev->netdev_ops         = &amt_netdev_ops;
2966 	dev->needs_free_netdev  = true;
2967 	SET_NETDEV_DEVTYPE(dev, &amt_type);
2968 	dev->min_mtu		= ETH_MIN_MTU;
2969 	dev->max_mtu		= ETH_MAX_MTU;
2970 	dev->type		= ARPHRD_NONE;
2971 	dev->flags		= IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
2972 	dev->hard_header_len	= 0;
2973 	dev->addr_len		= 0;
2974 	dev->priv_flags		|= IFF_NO_QUEUE;
2975 	dev->features		|= NETIF_F_LLTX;
2976 	dev->features		|= NETIF_F_GSO_SOFTWARE;
2977 	dev->features		|= NETIF_F_NETNS_LOCAL;
2978 	dev->hw_features	|= NETIF_F_SG | NETIF_F_HW_CSUM;
2979 	dev->hw_features	|= NETIF_F_FRAGLIST | NETIF_F_RXCSUM;
2980 	dev->hw_features	|= NETIF_F_GSO_SOFTWARE;
2981 	eth_hw_addr_random(dev);
2982 	eth_zero_addr(dev->broadcast);
2983 	ether_setup(dev);
2984 }
2985 
2986 static const struct nla_policy amt_policy[IFLA_AMT_MAX + 1] = {
2987 	[IFLA_AMT_MODE]		= { .type = NLA_U32 },
2988 	[IFLA_AMT_RELAY_PORT]	= { .type = NLA_U16 },
2989 	[IFLA_AMT_GATEWAY_PORT]	= { .type = NLA_U16 },
2990 	[IFLA_AMT_LINK]		= { .type = NLA_U32 },
2991 	[IFLA_AMT_LOCAL_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
2992 	[IFLA_AMT_REMOTE_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
2993 	[IFLA_AMT_DISCOVERY_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
2994 	[IFLA_AMT_MAX_TUNNELS]	= { .type = NLA_U32 },
2995 };
2996 
2997 static int amt_validate(struct nlattr *tb[], struct nlattr *data[],
2998 			struct netlink_ext_ack *extack)
2999 {
3000 	if (!data)
3001 		return -EINVAL;
3002 
3003 	if (!data[IFLA_AMT_LINK]) {
3004 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_LINK],
3005 				    "Link attribute is required");
3006 		return -EINVAL;
3007 	}
3008 
3009 	if (!data[IFLA_AMT_MODE]) {
3010 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_MODE],
3011 				    "Mode attribute is required");
3012 		return -EINVAL;
3013 	}
3014 
3015 	if (nla_get_u32(data[IFLA_AMT_MODE]) > AMT_MODE_MAX) {
3016 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_MODE],
3017 				    "Mode attribute is not valid");
3018 		return -EINVAL;
3019 	}
3020 
3021 	if (!data[IFLA_AMT_LOCAL_IP]) {
3022 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_DISCOVERY_IP],
3023 				    "Local attribute is required");
3024 		return -EINVAL;
3025 	}
3026 
3027 	if (!data[IFLA_AMT_DISCOVERY_IP] &&
3028 	    nla_get_u32(data[IFLA_AMT_MODE]) == AMT_MODE_GATEWAY) {
3029 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_LOCAL_IP],
3030 				    "Discovery attribute is required");
3031 		return -EINVAL;
3032 	}
3033 
3034 	return 0;
3035 }
3036 
3037 static int amt_newlink(struct net *net, struct net_device *dev,
3038 		       struct nlattr *tb[], struct nlattr *data[],
3039 		       struct netlink_ext_ack *extack)
3040 {
3041 	struct amt_dev *amt = netdev_priv(dev);
3042 	int err = -EINVAL;
3043 
3044 	amt->net = net;
3045 	amt->mode = nla_get_u32(data[IFLA_AMT_MODE]);
3046 
3047 	if (data[IFLA_AMT_MAX_TUNNELS] &&
3048 	    nla_get_u32(data[IFLA_AMT_MAX_TUNNELS]))
3049 		amt->max_tunnels = nla_get_u32(data[IFLA_AMT_MAX_TUNNELS]);
3050 	else
3051 		amt->max_tunnels = AMT_MAX_TUNNELS;
3052 
3053 	spin_lock_init(&amt->lock);
3054 	amt->max_groups = AMT_MAX_GROUP;
3055 	amt->max_sources = AMT_MAX_SOURCE;
3056 	amt->hash_buckets = AMT_HSIZE;
3057 	amt->nr_tunnels = 0;
3058 	get_random_bytes(&amt->hash_seed, sizeof(amt->hash_seed));
3059 	amt->stream_dev = dev_get_by_index(net,
3060 					   nla_get_u32(data[IFLA_AMT_LINK]));
3061 	if (!amt->stream_dev) {
3062 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LINK],
3063 				    "Can't find stream device");
3064 		return -ENODEV;
3065 	}
3066 
3067 	if (amt->stream_dev->type != ARPHRD_ETHER) {
3068 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LINK],
3069 				    "Invalid stream device type");
3070 		goto err;
3071 	}
3072 
3073 	amt->local_ip = nla_get_in_addr(data[IFLA_AMT_LOCAL_IP]);
3074 	if (ipv4_is_loopback(amt->local_ip) ||
3075 	    ipv4_is_zeronet(amt->local_ip) ||
3076 	    ipv4_is_multicast(amt->local_ip)) {
3077 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LOCAL_IP],
3078 				    "Invalid Local address");
3079 		goto err;
3080 	}
3081 
3082 	if (data[IFLA_AMT_RELAY_PORT])
3083 		amt->relay_port = nla_get_be16(data[IFLA_AMT_RELAY_PORT]);
3084 	else
3085 		amt->relay_port = htons(IANA_AMT_UDP_PORT);
3086 
3087 	if (data[IFLA_AMT_GATEWAY_PORT])
3088 		amt->gw_port = nla_get_be16(data[IFLA_AMT_GATEWAY_PORT]);
3089 	else
3090 		amt->gw_port = htons(IANA_AMT_UDP_PORT);
3091 
3092 	if (!amt->relay_port) {
3093 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3094 				    "relay port must not be 0");
3095 		goto err;
3096 	}
3097 	if (amt->mode == AMT_MODE_RELAY) {
3098 		amt->qrv = amt->net->ipv4.sysctl_igmp_qrv;
3099 		amt->qri = 10;
3100 		dev->needed_headroom = amt->stream_dev->needed_headroom +
3101 				       AMT_RELAY_HLEN;
3102 		dev->mtu = amt->stream_dev->mtu - AMT_RELAY_HLEN;
3103 		dev->max_mtu = dev->mtu;
3104 		dev->min_mtu = ETH_MIN_MTU + AMT_RELAY_HLEN;
3105 	} else {
3106 		if (!data[IFLA_AMT_DISCOVERY_IP]) {
3107 			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3108 					    "discovery must be set in gateway mode");
3109 			goto err;
3110 		}
3111 		if (!amt->gw_port) {
3112 			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3113 					    "gateway port must not be 0");
3114 			goto err;
3115 		}
3116 		amt->remote_ip = 0;
3117 		amt->discovery_ip = nla_get_in_addr(data[IFLA_AMT_DISCOVERY_IP]);
3118 		if (ipv4_is_loopback(amt->discovery_ip) ||
3119 		    ipv4_is_zeronet(amt->discovery_ip) ||
3120 		    ipv4_is_multicast(amt->discovery_ip)) {
3121 			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3122 					    "discovery must be unicast");
3123 			goto err;
3124 		}
3125 
3126 		dev->needed_headroom = amt->stream_dev->needed_headroom +
3127 				       AMT_GW_HLEN;
3128 		dev->mtu = amt->stream_dev->mtu - AMT_GW_HLEN;
3129 		dev->max_mtu = dev->mtu;
3130 		dev->min_mtu = ETH_MIN_MTU + AMT_GW_HLEN;
3131 	}
3132 	amt->qi = AMT_INIT_QUERY_INTERVAL;
3133 
3134 	err = register_netdevice(dev);
3135 	if (err < 0) {
3136 		netdev_dbg(dev, "failed to register new netdev %d\n", err);
3137 		goto err;
3138 	}
3139 
3140 	err = netdev_upper_dev_link(amt->stream_dev, dev, extack);
3141 	if (err < 0) {
3142 		unregister_netdevice(dev);
3143 		goto err;
3144 	}
3145 
3146 	INIT_DELAYED_WORK(&amt->discovery_wq, amt_discovery_work);
3147 	INIT_DELAYED_WORK(&amt->req_wq, amt_req_work);
3148 	INIT_DELAYED_WORK(&amt->secret_wq, amt_secret_work);
3149 	INIT_LIST_HEAD(&amt->tunnel_list);
3150 
3151 	return 0;
3152 err:
3153 	dev_put(amt->stream_dev);
3154 	return err;
3155 }
3156 
3157 static void amt_dellink(struct net_device *dev, struct list_head *head)
3158 {
3159 	struct amt_dev *amt = netdev_priv(dev);
3160 
3161 	unregister_netdevice_queue(dev, head);
3162 	netdev_upper_dev_unlink(amt->stream_dev, dev);
3163 	dev_put(amt->stream_dev);
3164 }
3165 
3166 static size_t amt_get_size(const struct net_device *dev)
3167 {
3168 	return nla_total_size(sizeof(__u32)) + /* IFLA_AMT_MODE */
3169 	       nla_total_size(sizeof(__u16)) + /* IFLA_AMT_RELAY_PORT */
3170 	       nla_total_size(sizeof(__u16)) + /* IFLA_AMT_GATEWAY_PORT */
3171 	       nla_total_size(sizeof(__u32)) + /* IFLA_AMT_LINK */
3172 	       nla_total_size(sizeof(__u32)) + /* IFLA_MAX_TUNNELS */
3173 	       nla_total_size(sizeof(struct iphdr)) + /* IFLA_AMT_DISCOVERY_IP */
3174 	       nla_total_size(sizeof(struct iphdr)) + /* IFLA_AMT_REMOTE_IP */
3175 	       nla_total_size(sizeof(struct iphdr)); /* IFLA_AMT_LOCAL_IP */
3176 }
3177 
3178 static int amt_fill_info(struct sk_buff *skb, const struct net_device *dev)
3179 {
3180 	struct amt_dev *amt = netdev_priv(dev);
3181 
3182 	if (nla_put_u32(skb, IFLA_AMT_MODE, amt->mode))
3183 		goto nla_put_failure;
3184 	if (nla_put_be16(skb, IFLA_AMT_RELAY_PORT, amt->relay_port))
3185 		goto nla_put_failure;
3186 	if (nla_put_be16(skb, IFLA_AMT_GATEWAY_PORT, amt->gw_port))
3187 		goto nla_put_failure;
3188 	if (nla_put_u32(skb, IFLA_AMT_LINK, amt->stream_dev->ifindex))
3189 		goto nla_put_failure;
3190 	if (nla_put_in_addr(skb, IFLA_AMT_LOCAL_IP, amt->local_ip))
3191 		goto nla_put_failure;
3192 	if (nla_put_in_addr(skb, IFLA_AMT_DISCOVERY_IP, amt->discovery_ip))
3193 		goto nla_put_failure;
3194 	if (amt->remote_ip)
3195 		if (nla_put_in_addr(skb, IFLA_AMT_REMOTE_IP, amt->remote_ip))
3196 			goto nla_put_failure;
3197 	if (nla_put_u32(skb, IFLA_AMT_MAX_TUNNELS, amt->max_tunnels))
3198 		goto nla_put_failure;
3199 
3200 	return 0;
3201 
3202 nla_put_failure:
3203 	return -EMSGSIZE;
3204 }
3205 
3206 static struct rtnl_link_ops amt_link_ops __read_mostly = {
3207 	.kind		= "amt",
3208 	.maxtype	= IFLA_AMT_MAX,
3209 	.policy		= amt_policy,
3210 	.priv_size	= sizeof(struct amt_dev),
3211 	.setup		= amt_link_setup,
3212 	.validate	= amt_validate,
3213 	.newlink	= amt_newlink,
3214 	.dellink	= amt_dellink,
3215 	.get_size       = amt_get_size,
3216 	.fill_info      = amt_fill_info,
3217 };
3218 
3219 static struct net_device *amt_lookup_upper_dev(struct net_device *dev)
3220 {
3221 	struct net_device *upper_dev;
3222 	struct amt_dev *amt;
3223 
3224 	for_each_netdev(dev_net(dev), upper_dev) {
3225 		if (netif_is_amt(upper_dev)) {
3226 			amt = netdev_priv(upper_dev);
3227 			if (amt->stream_dev == dev)
3228 				return upper_dev;
3229 		}
3230 	}
3231 
3232 	return NULL;
3233 }
3234 
3235 static int amt_device_event(struct notifier_block *unused,
3236 			    unsigned long event, void *ptr)
3237 {
3238 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3239 	struct net_device *upper_dev;
3240 	struct amt_dev *amt;
3241 	LIST_HEAD(list);
3242 	int new_mtu;
3243 
3244 	upper_dev = amt_lookup_upper_dev(dev);
3245 	if (!upper_dev)
3246 		return NOTIFY_DONE;
3247 	amt = netdev_priv(upper_dev);
3248 
3249 	switch (event) {
3250 	case NETDEV_UNREGISTER:
3251 		amt_dellink(amt->dev, &list);
3252 		unregister_netdevice_many(&list);
3253 		break;
3254 	case NETDEV_CHANGEMTU:
3255 		if (amt->mode == AMT_MODE_RELAY)
3256 			new_mtu = dev->mtu - AMT_RELAY_HLEN;
3257 		else
3258 			new_mtu = dev->mtu - AMT_GW_HLEN;
3259 
3260 		dev_set_mtu(amt->dev, new_mtu);
3261 		break;
3262 	}
3263 
3264 	return NOTIFY_DONE;
3265 }
3266 
3267 static struct notifier_block amt_notifier_block __read_mostly = {
3268 	.notifier_call = amt_device_event,
3269 };
3270 
3271 static int __init amt_init(void)
3272 {
3273 	int err;
3274 
3275 	err = register_netdevice_notifier(&amt_notifier_block);
3276 	if (err < 0)
3277 		goto err;
3278 
3279 	err = rtnl_link_register(&amt_link_ops);
3280 	if (err < 0)
3281 		goto unregister_notifier;
3282 
3283 	amt_wq = alloc_workqueue("amt", WQ_UNBOUND, 1);
3284 	if (!amt_wq) {
3285 		err = -ENOMEM;
3286 		goto rtnl_unregister;
3287 	}
3288 
3289 	spin_lock_init(&source_gc_lock);
3290 	spin_lock_bh(&source_gc_lock);
3291 	INIT_DELAYED_WORK(&source_gc_wq, amt_source_gc_work);
3292 	mod_delayed_work(amt_wq, &source_gc_wq,
3293 			 msecs_to_jiffies(AMT_GC_INTERVAL));
3294 	spin_unlock_bh(&source_gc_lock);
3295 
3296 	return 0;
3297 
3298 rtnl_unregister:
3299 	rtnl_link_unregister(&amt_link_ops);
3300 unregister_notifier:
3301 	unregister_netdevice_notifier(&amt_notifier_block);
3302 err:
3303 	pr_err("error loading AMT module loaded\n");
3304 	return err;
3305 }
3306 late_initcall(amt_init);
3307 
3308 static void __exit amt_fini(void)
3309 {
3310 	rtnl_link_unregister(&amt_link_ops);
3311 	unregister_netdevice_notifier(&amt_notifier_block);
3312 	cancel_delayed_work_sync(&source_gc_wq);
3313 	__amt_source_gc_work();
3314 	destroy_workqueue(amt_wq);
3315 }
3316 module_exit(amt_fini);
3317 
3318 MODULE_LICENSE("GPL");
3319 MODULE_AUTHOR("Taehee Yoo <ap420073@gmail.com>");
3320 MODULE_ALIAS_RTNL_LINK("amt");
3321