xref: /openbmc/linux/drivers/net/amt.c (revision 2bc7d3e0)
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 	"AMT_MSG_DISCOVERY",
55 	"AMT_MSG_ADVERTISEMENT",
56 	"AMT_MSG_REQUEST",
57 	"AMT_MSG_MEMBERSHIP_QUERY",
58 	"AMT_MSG_MEMBERSHIP_UPDATE",
59 	"AMT_MSG_MULTICAST_DATA",
60 	"AMT_MSG_TEARDOWN",
61 };
62 
63 static char *action_str[] = {
64 	"AMT_ACT_GMI",
65 	"AMT_ACT_GMI_ZERO",
66 	"AMT_ACT_GT",
67 	"AMT_ACT_STATUS_FWD_NEW",
68 	"AMT_ACT_STATUS_D_FWD_NEW",
69 	"AMT_ACT_STATUS_NONE_NEW",
70 };
71 
72 static struct igmpv3_grec igmpv3_zero_grec;
73 
74 #if IS_ENABLED(CONFIG_IPV6)
75 #define MLD2_ALL_NODE_INIT { { { 0xff, 0x02, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x01 } } }
76 static struct in6_addr mld2_all_node = MLD2_ALL_NODE_INIT;
77 static struct mld2_grec mldv2_zero_grec;
78 #endif
79 
80 static struct amt_skb_cb *amt_skb_cb(struct sk_buff *skb)
81 {
82 	BUILD_BUG_ON(sizeof(struct amt_skb_cb) + sizeof(struct qdisc_skb_cb) >
83 		     sizeof_field(struct sk_buff, cb));
84 
85 	return (struct amt_skb_cb *)((void *)skb->cb +
86 		sizeof(struct qdisc_skb_cb));
87 }
88 
89 static void __amt_source_gc_work(void)
90 {
91 	struct amt_source_node *snode;
92 	struct hlist_head gc_list;
93 	struct hlist_node *t;
94 
95 	spin_lock_bh(&source_gc_lock);
96 	hlist_move_list(&source_gc_list, &gc_list);
97 	spin_unlock_bh(&source_gc_lock);
98 
99 	hlist_for_each_entry_safe(snode, t, &gc_list, node) {
100 		hlist_del_rcu(&snode->node);
101 		kfree_rcu(snode, rcu);
102 	}
103 }
104 
105 static void amt_source_gc_work(struct work_struct *work)
106 {
107 	__amt_source_gc_work();
108 
109 	spin_lock_bh(&source_gc_lock);
110 	mod_delayed_work(amt_wq, &source_gc_wq,
111 			 msecs_to_jiffies(AMT_GC_INTERVAL));
112 	spin_unlock_bh(&source_gc_lock);
113 }
114 
115 static bool amt_addr_equal(union amt_addr *a, union amt_addr *b)
116 {
117 	return !memcmp(a, b, sizeof(union amt_addr));
118 }
119 
120 static u32 amt_source_hash(struct amt_tunnel_list *tunnel, union amt_addr *src)
121 {
122 	u32 hash = jhash(src, sizeof(*src), tunnel->amt->hash_seed);
123 
124 	return reciprocal_scale(hash, tunnel->amt->hash_buckets);
125 }
126 
127 static bool amt_status_filter(struct amt_source_node *snode,
128 			      enum amt_filter filter)
129 {
130 	bool rc = false;
131 
132 	switch (filter) {
133 	case AMT_FILTER_FWD:
134 		if (snode->status == AMT_SOURCE_STATUS_FWD &&
135 		    snode->flags == AMT_SOURCE_OLD)
136 			rc = true;
137 		break;
138 	case AMT_FILTER_D_FWD:
139 		if (snode->status == AMT_SOURCE_STATUS_D_FWD &&
140 		    snode->flags == AMT_SOURCE_OLD)
141 			rc = true;
142 		break;
143 	case AMT_FILTER_FWD_NEW:
144 		if (snode->status == AMT_SOURCE_STATUS_FWD &&
145 		    snode->flags == AMT_SOURCE_NEW)
146 			rc = true;
147 		break;
148 	case AMT_FILTER_D_FWD_NEW:
149 		if (snode->status == AMT_SOURCE_STATUS_D_FWD &&
150 		    snode->flags == AMT_SOURCE_NEW)
151 			rc = true;
152 		break;
153 	case AMT_FILTER_ALL:
154 		rc = true;
155 		break;
156 	case AMT_FILTER_NONE_NEW:
157 		if (snode->status == AMT_SOURCE_STATUS_NONE &&
158 		    snode->flags == AMT_SOURCE_NEW)
159 			rc = true;
160 		break;
161 	case AMT_FILTER_BOTH:
162 		if ((snode->status == AMT_SOURCE_STATUS_D_FWD ||
163 		     snode->status == AMT_SOURCE_STATUS_FWD) &&
164 		    snode->flags == AMT_SOURCE_OLD)
165 			rc = true;
166 		break;
167 	case AMT_FILTER_BOTH_NEW:
168 		if ((snode->status == AMT_SOURCE_STATUS_D_FWD ||
169 		     snode->status == AMT_SOURCE_STATUS_FWD) &&
170 		    snode->flags == AMT_SOURCE_NEW)
171 			rc = true;
172 		break;
173 	default:
174 		WARN_ON_ONCE(1);
175 		break;
176 	}
177 
178 	return rc;
179 }
180 
181 static struct amt_source_node *amt_lookup_src(struct amt_tunnel_list *tunnel,
182 					      struct amt_group_node *gnode,
183 					      enum amt_filter filter,
184 					      union amt_addr *src)
185 {
186 	u32 hash = amt_source_hash(tunnel, src);
187 	struct amt_source_node *snode;
188 
189 	hlist_for_each_entry_rcu(snode, &gnode->sources[hash], node)
190 		if (amt_status_filter(snode, filter) &&
191 		    amt_addr_equal(&snode->source_addr, src))
192 			return snode;
193 
194 	return NULL;
195 }
196 
197 static u32 amt_group_hash(struct amt_tunnel_list *tunnel, union amt_addr *group)
198 {
199 	u32 hash = jhash(group, sizeof(*group), tunnel->amt->hash_seed);
200 
201 	return reciprocal_scale(hash, tunnel->amt->hash_buckets);
202 }
203 
204 static struct amt_group_node *amt_lookup_group(struct amt_tunnel_list *tunnel,
205 					       union amt_addr *group,
206 					       union amt_addr *host,
207 					       bool v6)
208 {
209 	u32 hash = amt_group_hash(tunnel, group);
210 	struct amt_group_node *gnode;
211 
212 	hlist_for_each_entry_rcu(gnode, &tunnel->groups[hash], node) {
213 		if (amt_addr_equal(&gnode->group_addr, group) &&
214 		    amt_addr_equal(&gnode->host_addr, host) &&
215 		    gnode->v6 == v6)
216 			return gnode;
217 	}
218 
219 	return NULL;
220 }
221 
222 static void amt_destroy_source(struct amt_source_node *snode)
223 {
224 	struct amt_group_node *gnode = snode->gnode;
225 	struct amt_tunnel_list *tunnel;
226 
227 	tunnel = gnode->tunnel_list;
228 
229 	if (!gnode->v6) {
230 		netdev_dbg(snode->gnode->amt->dev,
231 			   "Delete source %pI4 from %pI4\n",
232 			   &snode->source_addr.ip4,
233 			   &gnode->group_addr.ip4);
234 #if IS_ENABLED(CONFIG_IPV6)
235 	} else {
236 		netdev_dbg(snode->gnode->amt->dev,
237 			   "Delete source %pI6 from %pI6\n",
238 			   &snode->source_addr.ip6,
239 			   &gnode->group_addr.ip6);
240 #endif
241 	}
242 
243 	cancel_delayed_work(&snode->source_timer);
244 	hlist_del_init_rcu(&snode->node);
245 	tunnel->nr_sources--;
246 	gnode->nr_sources--;
247 	spin_lock_bh(&source_gc_lock);
248 	hlist_add_head_rcu(&snode->node, &source_gc_list);
249 	spin_unlock_bh(&source_gc_lock);
250 }
251 
252 static void amt_del_group(struct amt_dev *amt, struct amt_group_node *gnode)
253 {
254 	struct amt_source_node *snode;
255 	struct hlist_node *t;
256 	int i;
257 
258 	if (cancel_delayed_work(&gnode->group_timer))
259 		dev_put(amt->dev);
260 	hlist_del_rcu(&gnode->node);
261 	gnode->tunnel_list->nr_groups--;
262 
263 	if (!gnode->v6)
264 		netdev_dbg(amt->dev, "Leave group %pI4\n",
265 			   &gnode->group_addr.ip4);
266 #if IS_ENABLED(CONFIG_IPV6)
267 	else
268 		netdev_dbg(amt->dev, "Leave group %pI6\n",
269 			   &gnode->group_addr.ip6);
270 #endif
271 	for (i = 0; i < amt->hash_buckets; i++)
272 		hlist_for_each_entry_safe(snode, t, &gnode->sources[i], node)
273 			amt_destroy_source(snode);
274 
275 	/* tunnel->lock was acquired outside of amt_del_group()
276 	 * But rcu_read_lock() was acquired too so It's safe.
277 	 */
278 	kfree_rcu(gnode, rcu);
279 }
280 
281 /* If a source timer expires with a router filter-mode for the group of
282  * INCLUDE, the router concludes that traffic from this particular
283  * source is no longer desired on the attached network, and deletes the
284  * associated source record.
285  */
286 static void amt_source_work(struct work_struct *work)
287 {
288 	struct amt_source_node *snode = container_of(to_delayed_work(work),
289 						     struct amt_source_node,
290 						     source_timer);
291 	struct amt_group_node *gnode = snode->gnode;
292 	struct amt_dev *amt = gnode->amt;
293 	struct amt_tunnel_list *tunnel;
294 
295 	tunnel = gnode->tunnel_list;
296 	spin_lock_bh(&tunnel->lock);
297 	rcu_read_lock();
298 	if (gnode->filter_mode == MCAST_INCLUDE) {
299 		amt_destroy_source(snode);
300 		if (!gnode->nr_sources)
301 			amt_del_group(amt, gnode);
302 	} else {
303 		/* When a router filter-mode for a group is EXCLUDE,
304 		 * source records are only deleted when the group timer expires
305 		 */
306 		snode->status = AMT_SOURCE_STATUS_D_FWD;
307 	}
308 	rcu_read_unlock();
309 	spin_unlock_bh(&tunnel->lock);
310 }
311 
312 static void amt_act_src(struct amt_tunnel_list *tunnel,
313 			struct amt_group_node *gnode,
314 			struct amt_source_node *snode,
315 			enum amt_act act)
316 {
317 	struct amt_dev *amt = tunnel->amt;
318 
319 	switch (act) {
320 	case AMT_ACT_GMI:
321 		mod_delayed_work(amt_wq, &snode->source_timer,
322 				 msecs_to_jiffies(amt_gmi(amt)));
323 		break;
324 	case AMT_ACT_GMI_ZERO:
325 		cancel_delayed_work(&snode->source_timer);
326 		break;
327 	case AMT_ACT_GT:
328 		mod_delayed_work(amt_wq, &snode->source_timer,
329 				 gnode->group_timer.timer.expires);
330 		break;
331 	case AMT_ACT_STATUS_FWD_NEW:
332 		snode->status = AMT_SOURCE_STATUS_FWD;
333 		snode->flags = AMT_SOURCE_NEW;
334 		break;
335 	case AMT_ACT_STATUS_D_FWD_NEW:
336 		snode->status = AMT_SOURCE_STATUS_D_FWD;
337 		snode->flags = AMT_SOURCE_NEW;
338 		break;
339 	case AMT_ACT_STATUS_NONE_NEW:
340 		cancel_delayed_work(&snode->source_timer);
341 		snode->status = AMT_SOURCE_STATUS_NONE;
342 		snode->flags = AMT_SOURCE_NEW;
343 		break;
344 	default:
345 		WARN_ON_ONCE(1);
346 		return;
347 	}
348 
349 	if (!gnode->v6)
350 		netdev_dbg(amt->dev, "Source %pI4 from %pI4 Acted %s\n",
351 			   &snode->source_addr.ip4,
352 			   &gnode->group_addr.ip4,
353 			   action_str[act]);
354 #if IS_ENABLED(CONFIG_IPV6)
355 	else
356 		netdev_dbg(amt->dev, "Source %pI6 from %pI6 Acted %s\n",
357 			   &snode->source_addr.ip6,
358 			   &gnode->group_addr.ip6,
359 			   action_str[act]);
360 #endif
361 }
362 
363 static struct amt_source_node *amt_alloc_snode(struct amt_group_node *gnode,
364 					       union amt_addr *src)
365 {
366 	struct amt_source_node *snode;
367 
368 	snode = kzalloc(sizeof(*snode), GFP_ATOMIC);
369 	if (!snode)
370 		return NULL;
371 
372 	memcpy(&snode->source_addr, src, sizeof(union amt_addr));
373 	snode->gnode = gnode;
374 	snode->status = AMT_SOURCE_STATUS_NONE;
375 	snode->flags = AMT_SOURCE_NEW;
376 	INIT_HLIST_NODE(&snode->node);
377 	INIT_DELAYED_WORK(&snode->source_timer, amt_source_work);
378 
379 	return snode;
380 }
381 
382 /* RFC 3810 - 7.2.2.  Definition of Filter Timers
383  *
384  *  Router Mode          Filter Timer         Actions/Comments
385  *  -----------       -----------------       ----------------
386  *
387  *    INCLUDE             Not Used            All listeners in
388  *                                            INCLUDE mode.
389  *
390  *    EXCLUDE             Timer > 0           At least one listener
391  *                                            in EXCLUDE mode.
392  *
393  *    EXCLUDE             Timer == 0          No more listeners in
394  *                                            EXCLUDE mode for the
395  *                                            multicast address.
396  *                                            If the Requested List
397  *                                            is empty, delete
398  *                                            Multicast Address
399  *                                            Record.  If not, switch
400  *                                            to INCLUDE filter mode;
401  *                                            the sources in the
402  *                                            Requested List are
403  *                                            moved to the Include
404  *                                            List, and the Exclude
405  *                                            List is deleted.
406  */
407 static void amt_group_work(struct work_struct *work)
408 {
409 	struct amt_group_node *gnode = container_of(to_delayed_work(work),
410 						    struct amt_group_node,
411 						    group_timer);
412 	struct amt_tunnel_list *tunnel = gnode->tunnel_list;
413 	struct amt_dev *amt = gnode->amt;
414 	struct amt_source_node *snode;
415 	bool delete_group = true;
416 	struct hlist_node *t;
417 	int i, buckets;
418 
419 	buckets = amt->hash_buckets;
420 
421 	spin_lock_bh(&tunnel->lock);
422 	if (gnode->filter_mode == MCAST_INCLUDE) {
423 		/* Not Used */
424 		spin_unlock_bh(&tunnel->lock);
425 		goto out;
426 	}
427 
428 	rcu_read_lock();
429 	for (i = 0; i < buckets; i++) {
430 		hlist_for_each_entry_safe(snode, t,
431 					  &gnode->sources[i], node) {
432 			if (!delayed_work_pending(&snode->source_timer) ||
433 			    snode->status == AMT_SOURCE_STATUS_D_FWD) {
434 				amt_destroy_source(snode);
435 			} else {
436 				delete_group = false;
437 				snode->status = AMT_SOURCE_STATUS_FWD;
438 			}
439 		}
440 	}
441 	if (delete_group)
442 		amt_del_group(amt, gnode);
443 	else
444 		gnode->filter_mode = MCAST_INCLUDE;
445 	rcu_read_unlock();
446 	spin_unlock_bh(&tunnel->lock);
447 out:
448 	dev_put(amt->dev);
449 }
450 
451 /* Non-existant group is created as INCLUDE {empty}:
452  *
453  * RFC 3376 - 5.1. Action on Change of Interface State
454  *
455  * If no interface state existed for that multicast address before
456  * the change (i.e., the change consisted of creating a new
457  * per-interface record), or if no state exists after the change
458  * (i.e., the change consisted of deleting a per-interface record),
459  * then the "non-existent" state is considered to have a filter mode
460  * of INCLUDE and an empty source list.
461  */
462 static struct amt_group_node *amt_add_group(struct amt_dev *amt,
463 					    struct amt_tunnel_list *tunnel,
464 					    union amt_addr *group,
465 					    union amt_addr *host,
466 					    bool v6)
467 {
468 	struct amt_group_node *gnode;
469 	u32 hash;
470 	int i;
471 
472 	if (tunnel->nr_groups >= amt->max_groups)
473 		return ERR_PTR(-ENOSPC);
474 
475 	gnode = kzalloc(sizeof(*gnode) +
476 			(sizeof(struct hlist_head) * amt->hash_buckets),
477 			GFP_ATOMIC);
478 	if (unlikely(!gnode))
479 		return ERR_PTR(-ENOMEM);
480 
481 	gnode->amt = amt;
482 	gnode->group_addr = *group;
483 	gnode->host_addr = *host;
484 	gnode->v6 = v6;
485 	gnode->tunnel_list = tunnel;
486 	gnode->filter_mode = MCAST_INCLUDE;
487 	INIT_HLIST_NODE(&gnode->node);
488 	INIT_DELAYED_WORK(&gnode->group_timer, amt_group_work);
489 	for (i = 0; i < amt->hash_buckets; i++)
490 		INIT_HLIST_HEAD(&gnode->sources[i]);
491 
492 	hash = amt_group_hash(tunnel, group);
493 	hlist_add_head_rcu(&gnode->node, &tunnel->groups[hash]);
494 	tunnel->nr_groups++;
495 
496 	if (!gnode->v6)
497 		netdev_dbg(amt->dev, "Join group %pI4\n",
498 			   &gnode->group_addr.ip4);
499 #if IS_ENABLED(CONFIG_IPV6)
500 	else
501 		netdev_dbg(amt->dev, "Join group %pI6\n",
502 			   &gnode->group_addr.ip6);
503 #endif
504 
505 	return gnode;
506 }
507 
508 static struct sk_buff *amt_build_igmp_gq(struct amt_dev *amt)
509 {
510 	u8 ra[AMT_IPHDR_OPTS] = { IPOPT_RA, 4, 0, 0 };
511 	int hlen = LL_RESERVED_SPACE(amt->dev);
512 	int tlen = amt->dev->needed_tailroom;
513 	struct igmpv3_query *ihv3;
514 	void *csum_start = NULL;
515 	__sum16 *csum = NULL;
516 	struct sk_buff *skb;
517 	struct ethhdr *eth;
518 	struct iphdr *iph;
519 	unsigned int len;
520 	int offset;
521 
522 	len = hlen + tlen + sizeof(*iph) + AMT_IPHDR_OPTS + sizeof(*ihv3);
523 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
524 	if (!skb)
525 		return NULL;
526 
527 	skb_reserve(skb, hlen);
528 	skb_push(skb, sizeof(*eth));
529 	skb->protocol = htons(ETH_P_IP);
530 	skb_reset_mac_header(skb);
531 	skb->priority = TC_PRIO_CONTROL;
532 	skb_put(skb, sizeof(*iph));
533 	skb_put_data(skb, ra, sizeof(ra));
534 	skb_put(skb, sizeof(*ihv3));
535 	skb_pull(skb, sizeof(*eth));
536 	skb_reset_network_header(skb);
537 
538 	iph		= ip_hdr(skb);
539 	iph->version	= 4;
540 	iph->ihl	= (sizeof(struct iphdr) + AMT_IPHDR_OPTS) >> 2;
541 	iph->tos	= AMT_TOS;
542 	iph->tot_len	= htons(sizeof(*iph) + AMT_IPHDR_OPTS + sizeof(*ihv3));
543 	iph->frag_off	= htons(IP_DF);
544 	iph->ttl	= 1;
545 	iph->id		= 0;
546 	iph->protocol	= IPPROTO_IGMP;
547 	iph->daddr	= htonl(INADDR_ALLHOSTS_GROUP);
548 	iph->saddr	= htonl(INADDR_ANY);
549 	ip_send_check(iph);
550 
551 	eth = eth_hdr(skb);
552 	ether_addr_copy(eth->h_source, amt->dev->dev_addr);
553 	ip_eth_mc_map(htonl(INADDR_ALLHOSTS_GROUP), eth->h_dest);
554 	eth->h_proto = htons(ETH_P_IP);
555 
556 	ihv3		= skb_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
557 	skb_reset_transport_header(skb);
558 	ihv3->type	= IGMP_HOST_MEMBERSHIP_QUERY;
559 	ihv3->code	= 1;
560 	ihv3->group	= 0;
561 	ihv3->qqic	= amt->qi;
562 	ihv3->nsrcs	= 0;
563 	ihv3->resv	= 0;
564 	ihv3->suppress	= false;
565 	ihv3->qrv	= amt->net->ipv4.sysctl_igmp_qrv;
566 	ihv3->csum	= 0;
567 	csum		= &ihv3->csum;
568 	csum_start	= (void *)ihv3;
569 	*csum		= ip_compute_csum(csum_start, sizeof(*ihv3));
570 	offset		= skb_transport_offset(skb);
571 	skb->csum	= skb_checksum(skb, offset, skb->len - offset, 0);
572 	skb->ip_summed	= CHECKSUM_NONE;
573 
574 	skb_push(skb, sizeof(*eth) + sizeof(*iph) + AMT_IPHDR_OPTS);
575 
576 	return skb;
577 }
578 
579 static void __amt_update_gw_status(struct amt_dev *amt, enum amt_status status,
580 				   bool validate)
581 {
582 	if (validate && amt->status >= status)
583 		return;
584 	netdev_dbg(amt->dev, "Update GW status %s -> %s",
585 		   status_str[amt->status], status_str[status]);
586 	amt->status = status;
587 }
588 
589 static void __amt_update_relay_status(struct amt_tunnel_list *tunnel,
590 				      enum amt_status status,
591 				      bool validate)
592 {
593 	if (validate && tunnel->status >= status)
594 		return;
595 	netdev_dbg(tunnel->amt->dev,
596 		   "Update Tunnel(IP = %pI4, PORT = %u) status %s -> %s",
597 		   &tunnel->ip4, ntohs(tunnel->source_port),
598 		   status_str[tunnel->status], status_str[status]);
599 	tunnel->status = status;
600 }
601 
602 static void amt_update_gw_status(struct amt_dev *amt, enum amt_status status,
603 				 bool validate)
604 {
605 	spin_lock_bh(&amt->lock);
606 	__amt_update_gw_status(amt, status, validate);
607 	spin_unlock_bh(&amt->lock);
608 }
609 
610 static void amt_update_relay_status(struct amt_tunnel_list *tunnel,
611 				    enum amt_status status, bool validate)
612 {
613 	spin_lock_bh(&tunnel->lock);
614 	__amt_update_relay_status(tunnel, status, validate);
615 	spin_unlock_bh(&tunnel->lock);
616 }
617 
618 static void amt_send_discovery(struct amt_dev *amt)
619 {
620 	struct amt_header_discovery *amtd;
621 	int hlen, tlen, offset;
622 	struct socket *sock;
623 	struct udphdr *udph;
624 	struct sk_buff *skb;
625 	struct iphdr *iph;
626 	struct rtable *rt;
627 	struct flowi4 fl4;
628 	u32 len;
629 	int err;
630 
631 	rcu_read_lock();
632 	sock = rcu_dereference(amt->sock);
633 	if (!sock)
634 		goto out;
635 
636 	if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
637 		goto out;
638 
639 	rt = ip_route_output_ports(amt->net, &fl4, sock->sk,
640 				   amt->discovery_ip, amt->local_ip,
641 				   amt->gw_port, amt->relay_port,
642 				   IPPROTO_UDP, 0,
643 				   amt->stream_dev->ifindex);
644 	if (IS_ERR(rt)) {
645 		amt->dev->stats.tx_errors++;
646 		goto out;
647 	}
648 
649 	hlen = LL_RESERVED_SPACE(amt->dev);
650 	tlen = amt->dev->needed_tailroom;
651 	len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amtd);
652 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
653 	if (!skb) {
654 		ip_rt_put(rt);
655 		amt->dev->stats.tx_errors++;
656 		goto out;
657 	}
658 
659 	skb->priority = TC_PRIO_CONTROL;
660 	skb_dst_set(skb, &rt->dst);
661 
662 	len = sizeof(*iph) + sizeof(*udph) + sizeof(*amtd);
663 	skb_reset_network_header(skb);
664 	skb_put(skb, len);
665 	amtd = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
666 	amtd->version	= 0;
667 	amtd->type	= AMT_MSG_DISCOVERY;
668 	amtd->reserved	= 0;
669 	amtd->nonce	= amt->nonce;
670 	skb_push(skb, sizeof(*udph));
671 	skb_reset_transport_header(skb);
672 	udph		= udp_hdr(skb);
673 	udph->source	= amt->gw_port;
674 	udph->dest	= amt->relay_port;
675 	udph->len	= htons(sizeof(*udph) + sizeof(*amtd));
676 	udph->check	= 0;
677 	offset = skb_transport_offset(skb);
678 	skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
679 	udph->check = csum_tcpudp_magic(amt->local_ip, amt->discovery_ip,
680 					sizeof(*udph) + sizeof(*amtd),
681 					IPPROTO_UDP, skb->csum);
682 
683 	skb_push(skb, sizeof(*iph));
684 	iph		= ip_hdr(skb);
685 	iph->version	= 4;
686 	iph->ihl	= (sizeof(struct iphdr)) >> 2;
687 	iph->tos	= AMT_TOS;
688 	iph->frag_off	= 0;
689 	iph->ttl	= ip4_dst_hoplimit(&rt->dst);
690 	iph->daddr	= amt->discovery_ip;
691 	iph->saddr	= amt->local_ip;
692 	iph->protocol	= IPPROTO_UDP;
693 	iph->tot_len	= htons(len);
694 
695 	skb->ip_summed = CHECKSUM_NONE;
696 	ip_select_ident(amt->net, skb, NULL);
697 	ip_send_check(iph);
698 	err = ip_local_out(amt->net, sock->sk, skb);
699 	if (unlikely(net_xmit_eval(err)))
700 		amt->dev->stats.tx_errors++;
701 
702 	spin_lock_bh(&amt->lock);
703 	__amt_update_gw_status(amt, AMT_STATUS_SENT_DISCOVERY, true);
704 	spin_unlock_bh(&amt->lock);
705 out:
706 	rcu_read_unlock();
707 }
708 
709 static void amt_send_request(struct amt_dev *amt, bool v6)
710 {
711 	struct amt_header_request *amtrh;
712 	int hlen, tlen, offset;
713 	struct socket *sock;
714 	struct udphdr *udph;
715 	struct sk_buff *skb;
716 	struct iphdr *iph;
717 	struct rtable *rt;
718 	struct flowi4 fl4;
719 	u32 len;
720 	int err;
721 
722 	rcu_read_lock();
723 	sock = rcu_dereference(amt->sock);
724 	if (!sock)
725 		goto out;
726 
727 	if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
728 		goto out;
729 
730 	rt = ip_route_output_ports(amt->net, &fl4, sock->sk,
731 				   amt->remote_ip, amt->local_ip,
732 				   amt->gw_port, amt->relay_port,
733 				   IPPROTO_UDP, 0,
734 				   amt->stream_dev->ifindex);
735 	if (IS_ERR(rt)) {
736 		amt->dev->stats.tx_errors++;
737 		goto out;
738 	}
739 
740 	hlen = LL_RESERVED_SPACE(amt->dev);
741 	tlen = amt->dev->needed_tailroom;
742 	len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amtrh);
743 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
744 	if (!skb) {
745 		ip_rt_put(rt);
746 		amt->dev->stats.tx_errors++;
747 		goto out;
748 	}
749 
750 	skb->priority = TC_PRIO_CONTROL;
751 	skb_dst_set(skb, &rt->dst);
752 
753 	len = sizeof(*iph) + sizeof(*udph) + sizeof(*amtrh);
754 	skb_reset_network_header(skb);
755 	skb_put(skb, len);
756 	amtrh = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
757 	amtrh->version	 = 0;
758 	amtrh->type	 = AMT_MSG_REQUEST;
759 	amtrh->reserved1 = 0;
760 	amtrh->p	 = v6;
761 	amtrh->reserved2 = 0;
762 	amtrh->nonce	 = amt->nonce;
763 	skb_push(skb, sizeof(*udph));
764 	skb_reset_transport_header(skb);
765 	udph		= udp_hdr(skb);
766 	udph->source	= amt->gw_port;
767 	udph->dest	= amt->relay_port;
768 	udph->len	= htons(sizeof(*amtrh) + sizeof(*udph));
769 	udph->check	= 0;
770 	offset = skb_transport_offset(skb);
771 	skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
772 	udph->check = csum_tcpudp_magic(amt->local_ip, amt->remote_ip,
773 					sizeof(*udph) + sizeof(*amtrh),
774 					IPPROTO_UDP, skb->csum);
775 
776 	skb_push(skb, sizeof(*iph));
777 	iph		= ip_hdr(skb);
778 	iph->version	= 4;
779 	iph->ihl	= (sizeof(struct iphdr)) >> 2;
780 	iph->tos	= AMT_TOS;
781 	iph->frag_off	= 0;
782 	iph->ttl	= ip4_dst_hoplimit(&rt->dst);
783 	iph->daddr	= amt->remote_ip;
784 	iph->saddr	= amt->local_ip;
785 	iph->protocol	= IPPROTO_UDP;
786 	iph->tot_len	= htons(len);
787 
788 	skb->ip_summed = CHECKSUM_NONE;
789 	ip_select_ident(amt->net, skb, NULL);
790 	ip_send_check(iph);
791 	err = ip_local_out(amt->net, sock->sk, skb);
792 	if (unlikely(net_xmit_eval(err)))
793 		amt->dev->stats.tx_errors++;
794 
795 out:
796 	rcu_read_unlock();
797 }
798 
799 static void amt_send_igmp_gq(struct amt_dev *amt,
800 			     struct amt_tunnel_list *tunnel)
801 {
802 	struct sk_buff *skb;
803 
804 	skb = amt_build_igmp_gq(amt);
805 	if (!skb)
806 		return;
807 
808 	amt_skb_cb(skb)->tunnel = tunnel;
809 	dev_queue_xmit(skb);
810 }
811 
812 #if IS_ENABLED(CONFIG_IPV6)
813 static struct sk_buff *amt_build_mld_gq(struct amt_dev *amt)
814 {
815 	u8 ra[AMT_IP6HDR_OPTS] = { IPPROTO_ICMPV6, 0, IPV6_TLV_ROUTERALERT,
816 				   2, 0, 0, IPV6_TLV_PAD1, IPV6_TLV_PAD1 };
817 	int hlen = LL_RESERVED_SPACE(amt->dev);
818 	int tlen = amt->dev->needed_tailroom;
819 	struct mld2_query *mld2q;
820 	void *csum_start = NULL;
821 	struct ipv6hdr *ip6h;
822 	struct sk_buff *skb;
823 	struct ethhdr *eth;
824 	u32 len;
825 
826 	len = hlen + tlen + sizeof(*ip6h) + sizeof(ra) + sizeof(*mld2q);
827 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
828 	if (!skb)
829 		return NULL;
830 
831 	skb_reserve(skb, hlen);
832 	skb_push(skb, sizeof(*eth));
833 	skb_reset_mac_header(skb);
834 	eth = eth_hdr(skb);
835 	skb->priority = TC_PRIO_CONTROL;
836 	skb->protocol = htons(ETH_P_IPV6);
837 	skb_put_zero(skb, sizeof(*ip6h));
838 	skb_put_data(skb, ra, sizeof(ra));
839 	skb_put_zero(skb, sizeof(*mld2q));
840 	skb_pull(skb, sizeof(*eth));
841 	skb_reset_network_header(skb);
842 	ip6h			= ipv6_hdr(skb);
843 	ip6h->payload_len	= htons(sizeof(ra) + sizeof(*mld2q));
844 	ip6h->nexthdr		= NEXTHDR_HOP;
845 	ip6h->hop_limit		= 1;
846 	ip6h->daddr		= mld2_all_node;
847 	ip6_flow_hdr(ip6h, 0, 0);
848 
849 	if (ipv6_dev_get_saddr(amt->net, amt->dev, &ip6h->daddr, 0,
850 			       &ip6h->saddr)) {
851 		amt->dev->stats.tx_errors++;
852 		kfree_skb(skb);
853 		return NULL;
854 	}
855 
856 	eth->h_proto = htons(ETH_P_IPV6);
857 	ether_addr_copy(eth->h_source, amt->dev->dev_addr);
858 	ipv6_eth_mc_map(&mld2_all_node, eth->h_dest);
859 
860 	skb_pull(skb, sizeof(*ip6h) + sizeof(ra));
861 	skb_reset_transport_header(skb);
862 	mld2q			= (struct mld2_query *)icmp6_hdr(skb);
863 	mld2q->mld2q_mrc	= htons(1);
864 	mld2q->mld2q_type	= ICMPV6_MGM_QUERY;
865 	mld2q->mld2q_code	= 0;
866 	mld2q->mld2q_cksum	= 0;
867 	mld2q->mld2q_resv1	= 0;
868 	mld2q->mld2q_resv2	= 0;
869 	mld2q->mld2q_suppress	= 0;
870 	mld2q->mld2q_qrv	= amt->qrv;
871 	mld2q->mld2q_nsrcs	= 0;
872 	mld2q->mld2q_qqic	= amt->qi;
873 	csum_start		= (void *)mld2q;
874 	mld2q->mld2q_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
875 					     sizeof(*mld2q),
876 					     IPPROTO_ICMPV6,
877 					     csum_partial(csum_start,
878 							  sizeof(*mld2q), 0));
879 
880 	skb->ip_summed = CHECKSUM_NONE;
881 	skb_push(skb, sizeof(*eth) + sizeof(*ip6h) + sizeof(ra));
882 	return skb;
883 }
884 
885 static void amt_send_mld_gq(struct amt_dev *amt, struct amt_tunnel_list *tunnel)
886 {
887 	struct sk_buff *skb;
888 
889 	skb = amt_build_mld_gq(amt);
890 	if (!skb)
891 		return;
892 
893 	amt_skb_cb(skb)->tunnel = tunnel;
894 	dev_queue_xmit(skb);
895 }
896 #else
897 static void amt_send_mld_gq(struct amt_dev *amt, struct amt_tunnel_list *tunnel)
898 {
899 }
900 #endif
901 
902 static void amt_secret_work(struct work_struct *work)
903 {
904 	struct amt_dev *amt = container_of(to_delayed_work(work),
905 					   struct amt_dev,
906 					   secret_wq);
907 
908 	spin_lock_bh(&amt->lock);
909 	get_random_bytes(&amt->key, sizeof(siphash_key_t));
910 	spin_unlock_bh(&amt->lock);
911 	mod_delayed_work(amt_wq, &amt->secret_wq,
912 			 msecs_to_jiffies(AMT_SECRET_TIMEOUT));
913 }
914 
915 static void amt_discovery_work(struct work_struct *work)
916 {
917 	struct amt_dev *amt = container_of(to_delayed_work(work),
918 					   struct amt_dev,
919 					   discovery_wq);
920 
921 	spin_lock_bh(&amt->lock);
922 	if (amt->status > AMT_STATUS_SENT_DISCOVERY)
923 		goto out;
924 	get_random_bytes(&amt->nonce, sizeof(__be32));
925 	spin_unlock_bh(&amt->lock);
926 
927 	amt_send_discovery(amt);
928 	spin_lock_bh(&amt->lock);
929 out:
930 	mod_delayed_work(amt_wq, &amt->discovery_wq,
931 			 msecs_to_jiffies(AMT_DISCOVERY_TIMEOUT));
932 	spin_unlock_bh(&amt->lock);
933 }
934 
935 static void amt_req_work(struct work_struct *work)
936 {
937 	struct amt_dev *amt = container_of(to_delayed_work(work),
938 					   struct amt_dev,
939 					   req_wq);
940 	u32 exp;
941 
942 	spin_lock_bh(&amt->lock);
943 	if (amt->status < AMT_STATUS_RECEIVED_ADVERTISEMENT)
944 		goto out;
945 
946 	if (amt->req_cnt > AMT_MAX_REQ_COUNT) {
947 		netdev_dbg(amt->dev, "Gateway is not ready");
948 		amt->qi = AMT_INIT_REQ_TIMEOUT;
949 		amt->ready4 = false;
950 		amt->ready6 = false;
951 		amt->remote_ip = 0;
952 		__amt_update_gw_status(amt, AMT_STATUS_INIT, false);
953 		amt->req_cnt = 0;
954 		goto out;
955 	}
956 	spin_unlock_bh(&amt->lock);
957 
958 	amt_send_request(amt, false);
959 	amt_send_request(amt, true);
960 	spin_lock_bh(&amt->lock);
961 	__amt_update_gw_status(amt, AMT_STATUS_SENT_REQUEST, true);
962 	amt->req_cnt++;
963 out:
964 	exp = min_t(u32, (1 * (1 << amt->req_cnt)), AMT_MAX_REQ_TIMEOUT);
965 	mod_delayed_work(amt_wq, &amt->req_wq, msecs_to_jiffies(exp * 1000));
966 	spin_unlock_bh(&amt->lock);
967 }
968 
969 static bool amt_send_membership_update(struct amt_dev *amt,
970 				       struct sk_buff *skb,
971 				       bool v6)
972 {
973 	struct amt_header_membership_update *amtmu;
974 	struct socket *sock;
975 	struct iphdr *iph;
976 	struct flowi4 fl4;
977 	struct rtable *rt;
978 	int err;
979 
980 	sock = rcu_dereference_bh(amt->sock);
981 	if (!sock)
982 		return true;
983 
984 	err = skb_cow_head(skb, LL_RESERVED_SPACE(amt->dev) + sizeof(*amtmu) +
985 			   sizeof(*iph) + sizeof(struct udphdr));
986 	if (err)
987 		return true;
988 
989 	skb_reset_inner_headers(skb);
990 	memset(&fl4, 0, sizeof(struct flowi4));
991 	fl4.flowi4_oif         = amt->stream_dev->ifindex;
992 	fl4.daddr              = amt->remote_ip;
993 	fl4.saddr              = amt->local_ip;
994 	fl4.flowi4_tos         = AMT_TOS;
995 	fl4.flowi4_proto       = IPPROTO_UDP;
996 	rt = ip_route_output_key(amt->net, &fl4);
997 	if (IS_ERR(rt)) {
998 		netdev_dbg(amt->dev, "no route to %pI4\n", &amt->remote_ip);
999 		return true;
1000 	}
1001 
1002 	amtmu			= skb_push(skb, sizeof(*amtmu));
1003 	amtmu->version		= 0;
1004 	amtmu->type		= AMT_MSG_MEMBERSHIP_UPDATE;
1005 	amtmu->reserved		= 0;
1006 	amtmu->nonce		= amt->nonce;
1007 	amtmu->response_mac	= amt->mac;
1008 
1009 	if (!v6)
1010 		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1011 	else
1012 		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1013 	udp_tunnel_xmit_skb(rt, sock->sk, skb,
1014 			    fl4.saddr,
1015 			    fl4.daddr,
1016 			    AMT_TOS,
1017 			    ip4_dst_hoplimit(&rt->dst),
1018 			    0,
1019 			    amt->gw_port,
1020 			    amt->relay_port,
1021 			    false,
1022 			    false);
1023 	amt_update_gw_status(amt, AMT_STATUS_SENT_UPDATE, true);
1024 	return false;
1025 }
1026 
1027 static void amt_send_multicast_data(struct amt_dev *amt,
1028 				    const struct sk_buff *oskb,
1029 				    struct amt_tunnel_list *tunnel,
1030 				    bool v6)
1031 {
1032 	struct amt_header_mcast_data *amtmd;
1033 	struct socket *sock;
1034 	struct sk_buff *skb;
1035 	struct iphdr *iph;
1036 	struct flowi4 fl4;
1037 	struct rtable *rt;
1038 
1039 	sock = rcu_dereference_bh(amt->sock);
1040 	if (!sock)
1041 		return;
1042 
1043 	skb = skb_copy_expand(oskb, sizeof(*amtmd) + sizeof(*iph) +
1044 			      sizeof(struct udphdr), 0, GFP_ATOMIC);
1045 	if (!skb)
1046 		return;
1047 
1048 	skb_reset_inner_headers(skb);
1049 	memset(&fl4, 0, sizeof(struct flowi4));
1050 	fl4.flowi4_oif         = amt->stream_dev->ifindex;
1051 	fl4.daddr              = tunnel->ip4;
1052 	fl4.saddr              = amt->local_ip;
1053 	fl4.flowi4_proto       = IPPROTO_UDP;
1054 	rt = ip_route_output_key(amt->net, &fl4);
1055 	if (IS_ERR(rt)) {
1056 		netdev_dbg(amt->dev, "no route to %pI4\n", &tunnel->ip4);
1057 		kfree_skb(skb);
1058 		return;
1059 	}
1060 
1061 	amtmd = skb_push(skb, sizeof(*amtmd));
1062 	amtmd->version = 0;
1063 	amtmd->reserved = 0;
1064 	amtmd->type = AMT_MSG_MULTICAST_DATA;
1065 
1066 	if (!v6)
1067 		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1068 	else
1069 		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1070 	udp_tunnel_xmit_skb(rt, sock->sk, skb,
1071 			    fl4.saddr,
1072 			    fl4.daddr,
1073 			    AMT_TOS,
1074 			    ip4_dst_hoplimit(&rt->dst),
1075 			    0,
1076 			    amt->relay_port,
1077 			    tunnel->source_port,
1078 			    false,
1079 			    false);
1080 }
1081 
1082 static bool amt_send_membership_query(struct amt_dev *amt,
1083 				      struct sk_buff *skb,
1084 				      struct amt_tunnel_list *tunnel,
1085 				      bool v6)
1086 {
1087 	struct amt_header_membership_query *amtmq;
1088 	struct socket *sock;
1089 	struct rtable *rt;
1090 	struct flowi4 fl4;
1091 	int err;
1092 
1093 	sock = rcu_dereference_bh(amt->sock);
1094 	if (!sock)
1095 		return true;
1096 
1097 	err = skb_cow_head(skb, LL_RESERVED_SPACE(amt->dev) + sizeof(*amtmq) +
1098 			   sizeof(struct iphdr) + sizeof(struct udphdr));
1099 	if (err)
1100 		return true;
1101 
1102 	skb_reset_inner_headers(skb);
1103 	memset(&fl4, 0, sizeof(struct flowi4));
1104 	fl4.flowi4_oif         = amt->stream_dev->ifindex;
1105 	fl4.daddr              = tunnel->ip4;
1106 	fl4.saddr              = amt->local_ip;
1107 	fl4.flowi4_tos         = AMT_TOS;
1108 	fl4.flowi4_proto       = IPPROTO_UDP;
1109 	rt = ip_route_output_key(amt->net, &fl4);
1110 	if (IS_ERR(rt)) {
1111 		netdev_dbg(amt->dev, "no route to %pI4\n", &tunnel->ip4);
1112 		return true;
1113 	}
1114 
1115 	amtmq		= skb_push(skb, sizeof(*amtmq));
1116 	amtmq->version	= 0;
1117 	amtmq->type	= AMT_MSG_MEMBERSHIP_QUERY;
1118 	amtmq->reserved = 0;
1119 	amtmq->l	= 0;
1120 	amtmq->g	= 0;
1121 	amtmq->nonce	= tunnel->nonce;
1122 	amtmq->response_mac = tunnel->mac;
1123 
1124 	if (!v6)
1125 		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1126 	else
1127 		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1128 	udp_tunnel_xmit_skb(rt, sock->sk, skb,
1129 			    fl4.saddr,
1130 			    fl4.daddr,
1131 			    AMT_TOS,
1132 			    ip4_dst_hoplimit(&rt->dst),
1133 			    0,
1134 			    amt->relay_port,
1135 			    tunnel->source_port,
1136 			    false,
1137 			    false);
1138 	amt_update_relay_status(tunnel, AMT_STATUS_SENT_QUERY, true);
1139 	return false;
1140 }
1141 
1142 static netdev_tx_t amt_dev_xmit(struct sk_buff *skb, struct net_device *dev)
1143 {
1144 	struct amt_dev *amt = netdev_priv(dev);
1145 	struct amt_tunnel_list *tunnel;
1146 	struct amt_group_node *gnode;
1147 	union amt_addr group = {0,};
1148 #if IS_ENABLED(CONFIG_IPV6)
1149 	struct ipv6hdr *ip6h;
1150 	struct mld_msg *mld;
1151 #endif
1152 	bool report = false;
1153 	struct igmphdr *ih;
1154 	bool query = false;
1155 	struct iphdr *iph;
1156 	bool data = false;
1157 	bool v6 = false;
1158 	u32 hash;
1159 
1160 	iph = ip_hdr(skb);
1161 	if (iph->version == 4) {
1162 		if (!ipv4_is_multicast(iph->daddr))
1163 			goto free;
1164 
1165 		if (!ip_mc_check_igmp(skb)) {
1166 			ih = igmp_hdr(skb);
1167 			switch (ih->type) {
1168 			case IGMPV3_HOST_MEMBERSHIP_REPORT:
1169 			case IGMP_HOST_MEMBERSHIP_REPORT:
1170 				report = true;
1171 				break;
1172 			case IGMP_HOST_MEMBERSHIP_QUERY:
1173 				query = true;
1174 				break;
1175 			default:
1176 				goto free;
1177 			}
1178 		} else {
1179 			data = true;
1180 		}
1181 		v6 = false;
1182 		group.ip4 = iph->daddr;
1183 #if IS_ENABLED(CONFIG_IPV6)
1184 	} else if (iph->version == 6) {
1185 		ip6h = ipv6_hdr(skb);
1186 		if (!ipv6_addr_is_multicast(&ip6h->daddr))
1187 			goto free;
1188 
1189 		if (!ipv6_mc_check_mld(skb)) {
1190 			mld = (struct mld_msg *)skb_transport_header(skb);
1191 			switch (mld->mld_type) {
1192 			case ICMPV6_MGM_REPORT:
1193 			case ICMPV6_MLD2_REPORT:
1194 				report = true;
1195 				break;
1196 			case ICMPV6_MGM_QUERY:
1197 				query = true;
1198 				break;
1199 			default:
1200 				goto free;
1201 			}
1202 		} else {
1203 			data = true;
1204 		}
1205 		v6 = true;
1206 		group.ip6 = ip6h->daddr;
1207 #endif
1208 	} else {
1209 		dev->stats.tx_errors++;
1210 		goto free;
1211 	}
1212 
1213 	if (!pskb_may_pull(skb, sizeof(struct ethhdr)))
1214 		goto free;
1215 
1216 	skb_pull(skb, sizeof(struct ethhdr));
1217 
1218 	if (amt->mode == AMT_MODE_GATEWAY) {
1219 		/* Gateway only passes IGMP/MLD packets */
1220 		if (!report)
1221 			goto free;
1222 		if ((!v6 && !amt->ready4) || (v6 && !amt->ready6))
1223 			goto free;
1224 		if (amt_send_membership_update(amt, skb,  v6))
1225 			goto free;
1226 		goto unlock;
1227 	} else if (amt->mode == AMT_MODE_RELAY) {
1228 		if (query) {
1229 			tunnel = amt_skb_cb(skb)->tunnel;
1230 			if (!tunnel) {
1231 				WARN_ON(1);
1232 				goto free;
1233 			}
1234 
1235 			/* Do not forward unexpected query */
1236 			if (amt_send_membership_query(amt, skb, tunnel, v6))
1237 				goto free;
1238 			goto unlock;
1239 		}
1240 
1241 		if (!data)
1242 			goto free;
1243 		list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list) {
1244 			hash = amt_group_hash(tunnel, &group);
1245 			hlist_for_each_entry_rcu(gnode, &tunnel->groups[hash],
1246 						 node) {
1247 				if (!v6) {
1248 					if (gnode->group_addr.ip4 == iph->daddr)
1249 						goto found;
1250 #if IS_ENABLED(CONFIG_IPV6)
1251 				} else {
1252 					if (ipv6_addr_equal(&gnode->group_addr.ip6,
1253 							    &ip6h->daddr))
1254 						goto found;
1255 #endif
1256 				}
1257 			}
1258 			continue;
1259 found:
1260 			amt_send_multicast_data(amt, skb, tunnel, v6);
1261 		}
1262 	}
1263 
1264 	dev_kfree_skb(skb);
1265 	return NETDEV_TX_OK;
1266 free:
1267 	dev_kfree_skb(skb);
1268 unlock:
1269 	dev->stats.tx_dropped++;
1270 	return NETDEV_TX_OK;
1271 }
1272 
1273 static int amt_parse_type(struct sk_buff *skb)
1274 {
1275 	struct amt_header *amth;
1276 
1277 	if (!pskb_may_pull(skb, sizeof(struct udphdr) +
1278 			   sizeof(struct amt_header)))
1279 		return -1;
1280 
1281 	amth = (struct amt_header *)(udp_hdr(skb) + 1);
1282 
1283 	if (amth->version != 0)
1284 		return -1;
1285 
1286 	if (amth->type >= __AMT_MSG_MAX || !amth->type)
1287 		return -1;
1288 	return amth->type;
1289 }
1290 
1291 static void amt_clear_groups(struct amt_tunnel_list *tunnel)
1292 {
1293 	struct amt_dev *amt = tunnel->amt;
1294 	struct amt_group_node *gnode;
1295 	struct hlist_node *t;
1296 	int i;
1297 
1298 	spin_lock_bh(&tunnel->lock);
1299 	rcu_read_lock();
1300 	for (i = 0; i < amt->hash_buckets; i++)
1301 		hlist_for_each_entry_safe(gnode, t, &tunnel->groups[i], node)
1302 			amt_del_group(amt, gnode);
1303 	rcu_read_unlock();
1304 	spin_unlock_bh(&tunnel->lock);
1305 }
1306 
1307 static void amt_tunnel_expire(struct work_struct *work)
1308 {
1309 	struct amt_tunnel_list *tunnel = container_of(to_delayed_work(work),
1310 						      struct amt_tunnel_list,
1311 						      gc_wq);
1312 	struct amt_dev *amt = tunnel->amt;
1313 
1314 	spin_lock_bh(&amt->lock);
1315 	rcu_read_lock();
1316 	list_del_rcu(&tunnel->list);
1317 	amt->nr_tunnels--;
1318 	amt_clear_groups(tunnel);
1319 	rcu_read_unlock();
1320 	spin_unlock_bh(&amt->lock);
1321 	kfree_rcu(tunnel, rcu);
1322 }
1323 
1324 static void amt_cleanup_srcs(struct amt_dev *amt,
1325 			     struct amt_tunnel_list *tunnel,
1326 			     struct amt_group_node *gnode)
1327 {
1328 	struct amt_source_node *snode;
1329 	struct hlist_node *t;
1330 	int i;
1331 
1332 	/* Delete old sources */
1333 	for (i = 0; i < amt->hash_buckets; i++) {
1334 		hlist_for_each_entry_safe(snode, t, &gnode->sources[i], node) {
1335 			if (snode->flags == AMT_SOURCE_OLD)
1336 				amt_destroy_source(snode);
1337 		}
1338 	}
1339 
1340 	/* switch from new to old */
1341 	for (i = 0; i < amt->hash_buckets; i++)  {
1342 		hlist_for_each_entry_rcu(snode, &gnode->sources[i], node) {
1343 			snode->flags = AMT_SOURCE_OLD;
1344 			if (!gnode->v6)
1345 				netdev_dbg(snode->gnode->amt->dev,
1346 					   "Add source as OLD %pI4 from %pI4\n",
1347 					   &snode->source_addr.ip4,
1348 					   &gnode->group_addr.ip4);
1349 #if IS_ENABLED(CONFIG_IPV6)
1350 			else
1351 				netdev_dbg(snode->gnode->amt->dev,
1352 					   "Add source as OLD %pI6 from %pI6\n",
1353 					   &snode->source_addr.ip6,
1354 					   &gnode->group_addr.ip6);
1355 #endif
1356 		}
1357 	}
1358 }
1359 
1360 static void amt_add_srcs(struct amt_dev *amt, struct amt_tunnel_list *tunnel,
1361 			 struct amt_group_node *gnode, void *grec,
1362 			 bool v6)
1363 {
1364 	struct igmpv3_grec *igmp_grec;
1365 	struct amt_source_node *snode;
1366 #if IS_ENABLED(CONFIG_IPV6)
1367 	struct mld2_grec *mld_grec;
1368 #endif
1369 	union amt_addr src = {0,};
1370 	u16 nsrcs;
1371 	u32 hash;
1372 	int i;
1373 
1374 	if (!v6) {
1375 		igmp_grec = (struct igmpv3_grec *)grec;
1376 		nsrcs = ntohs(igmp_grec->grec_nsrcs);
1377 	} else {
1378 #if IS_ENABLED(CONFIG_IPV6)
1379 		mld_grec = (struct mld2_grec *)grec;
1380 		nsrcs = ntohs(mld_grec->grec_nsrcs);
1381 #else
1382 	return;
1383 #endif
1384 	}
1385 	for (i = 0; i < nsrcs; i++) {
1386 		if (tunnel->nr_sources >= amt->max_sources)
1387 			return;
1388 		if (!v6)
1389 			src.ip4 = igmp_grec->grec_src[i];
1390 #if IS_ENABLED(CONFIG_IPV6)
1391 		else
1392 			memcpy(&src.ip6, &mld_grec->grec_src[i],
1393 			       sizeof(struct in6_addr));
1394 #endif
1395 		if (amt_lookup_src(tunnel, gnode, AMT_FILTER_ALL, &src))
1396 			continue;
1397 
1398 		snode = amt_alloc_snode(gnode, &src);
1399 		if (snode) {
1400 			hash = amt_source_hash(tunnel, &snode->source_addr);
1401 			hlist_add_head_rcu(&snode->node, &gnode->sources[hash]);
1402 			tunnel->nr_sources++;
1403 			gnode->nr_sources++;
1404 
1405 			if (!gnode->v6)
1406 				netdev_dbg(snode->gnode->amt->dev,
1407 					   "Add source as NEW %pI4 from %pI4\n",
1408 					   &snode->source_addr.ip4,
1409 					   &gnode->group_addr.ip4);
1410 #if IS_ENABLED(CONFIG_IPV6)
1411 			else
1412 				netdev_dbg(snode->gnode->amt->dev,
1413 					   "Add source as NEW %pI6 from %pI6\n",
1414 					   &snode->source_addr.ip6,
1415 					   &gnode->group_addr.ip6);
1416 #endif
1417 		}
1418 	}
1419 }
1420 
1421 /* Router State   Report Rec'd New Router State
1422  * ------------   ------------ ----------------
1423  * EXCLUDE (X,Y)  IS_IN (A)    EXCLUDE (X+A,Y-A)
1424  *
1425  * -----------+-----------+-----------+
1426  *            |    OLD    |    NEW    |
1427  * -----------+-----------+-----------+
1428  *    FWD     |     X     |    X+A    |
1429  * -----------+-----------+-----------+
1430  *    D_FWD   |     Y     |    Y-A    |
1431  * -----------+-----------+-----------+
1432  *    NONE    |           |     A     |
1433  * -----------+-----------+-----------+
1434  *
1435  * a) Received sources are NONE/NEW
1436  * b) All NONE will be deleted by amt_cleanup_srcs().
1437  * c) All OLD will be deleted by amt_cleanup_srcs().
1438  * d) After delete, NEW source will be switched to OLD.
1439  */
1440 static void amt_lookup_act_srcs(struct amt_tunnel_list *tunnel,
1441 				struct amt_group_node *gnode,
1442 				void *grec,
1443 				enum amt_ops ops,
1444 				enum amt_filter filter,
1445 				enum amt_act act,
1446 				bool v6)
1447 {
1448 	struct amt_dev *amt = tunnel->amt;
1449 	struct amt_source_node *snode;
1450 	struct igmpv3_grec *igmp_grec;
1451 #if IS_ENABLED(CONFIG_IPV6)
1452 	struct mld2_grec *mld_grec;
1453 #endif
1454 	union amt_addr src = {0,};
1455 	struct hlist_node *t;
1456 	u16 nsrcs;
1457 	int i, j;
1458 
1459 	if (!v6) {
1460 		igmp_grec = (struct igmpv3_grec *)grec;
1461 		nsrcs = ntohs(igmp_grec->grec_nsrcs);
1462 	} else {
1463 #if IS_ENABLED(CONFIG_IPV6)
1464 		mld_grec = (struct mld2_grec *)grec;
1465 		nsrcs = ntohs(mld_grec->grec_nsrcs);
1466 #else
1467 	return;
1468 #endif
1469 	}
1470 
1471 	memset(&src, 0, sizeof(union amt_addr));
1472 	switch (ops) {
1473 	case AMT_OPS_INT:
1474 		/* A*B */
1475 		for (i = 0; i < nsrcs; i++) {
1476 			if (!v6)
1477 				src.ip4 = igmp_grec->grec_src[i];
1478 #if IS_ENABLED(CONFIG_IPV6)
1479 			else
1480 				memcpy(&src.ip6, &mld_grec->grec_src[i],
1481 				       sizeof(struct in6_addr));
1482 #endif
1483 			snode = amt_lookup_src(tunnel, gnode, filter, &src);
1484 			if (!snode)
1485 				continue;
1486 			amt_act_src(tunnel, gnode, snode, act);
1487 		}
1488 		break;
1489 	case AMT_OPS_UNI:
1490 		/* A+B */
1491 		for (i = 0; i < amt->hash_buckets; i++) {
1492 			hlist_for_each_entry_safe(snode, t, &gnode->sources[i],
1493 						  node) {
1494 				if (amt_status_filter(snode, filter))
1495 					amt_act_src(tunnel, gnode, snode, act);
1496 			}
1497 		}
1498 		for (i = 0; i < nsrcs; i++) {
1499 			if (!v6)
1500 				src.ip4 = igmp_grec->grec_src[i];
1501 #if IS_ENABLED(CONFIG_IPV6)
1502 			else
1503 				memcpy(&src.ip6, &mld_grec->grec_src[i],
1504 				       sizeof(struct in6_addr));
1505 #endif
1506 			snode = amt_lookup_src(tunnel, gnode, filter, &src);
1507 			if (!snode)
1508 				continue;
1509 			amt_act_src(tunnel, gnode, snode, act);
1510 		}
1511 		break;
1512 	case AMT_OPS_SUB:
1513 		/* A-B */
1514 		for (i = 0; i < amt->hash_buckets; i++) {
1515 			hlist_for_each_entry_safe(snode, t, &gnode->sources[i],
1516 						  node) {
1517 				if (!amt_status_filter(snode, filter))
1518 					continue;
1519 				for (j = 0; j < nsrcs; j++) {
1520 					if (!v6)
1521 						src.ip4 = igmp_grec->grec_src[j];
1522 #if IS_ENABLED(CONFIG_IPV6)
1523 					else
1524 						memcpy(&src.ip6,
1525 						       &mld_grec->grec_src[j],
1526 						       sizeof(struct in6_addr));
1527 #endif
1528 					if (amt_addr_equal(&snode->source_addr,
1529 							   &src))
1530 						goto out_sub;
1531 				}
1532 				amt_act_src(tunnel, gnode, snode, act);
1533 				continue;
1534 out_sub:;
1535 			}
1536 		}
1537 		break;
1538 	case AMT_OPS_SUB_REV:
1539 		/* B-A */
1540 		for (i = 0; i < nsrcs; i++) {
1541 			if (!v6)
1542 				src.ip4 = igmp_grec->grec_src[i];
1543 #if IS_ENABLED(CONFIG_IPV6)
1544 			else
1545 				memcpy(&src.ip6, &mld_grec->grec_src[i],
1546 				       sizeof(struct in6_addr));
1547 #endif
1548 			snode = amt_lookup_src(tunnel, gnode, AMT_FILTER_ALL,
1549 					       &src);
1550 			if (!snode) {
1551 				snode = amt_lookup_src(tunnel, gnode,
1552 						       filter, &src);
1553 				if (snode)
1554 					amt_act_src(tunnel, gnode, snode, act);
1555 			}
1556 		}
1557 		break;
1558 	default:
1559 		netdev_dbg(amt->dev, "Invalid type\n");
1560 		return;
1561 	}
1562 }
1563 
1564 static void amt_mcast_is_in_handler(struct amt_dev *amt,
1565 				    struct amt_tunnel_list *tunnel,
1566 				    struct amt_group_node *gnode,
1567 				    void *grec, void *zero_grec, bool v6)
1568 {
1569 	if (gnode->filter_mode == MCAST_INCLUDE) {
1570 /* Router State   Report Rec'd New Router State        Actions
1571  * ------------   ------------ ----------------        -------
1572  * INCLUDE (A)    IS_IN (B)    INCLUDE (A+B)           (B)=GMI
1573  */
1574 		/* Update IS_IN (B) as FWD/NEW */
1575 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1576 				    AMT_FILTER_NONE_NEW,
1577 				    AMT_ACT_STATUS_FWD_NEW,
1578 				    v6);
1579 		/* Update INCLUDE (A) as NEW */
1580 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1581 				    AMT_FILTER_FWD,
1582 				    AMT_ACT_STATUS_FWD_NEW,
1583 				    v6);
1584 		/* (B)=GMI */
1585 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1586 				    AMT_FILTER_FWD_NEW,
1587 				    AMT_ACT_GMI,
1588 				    v6);
1589 	} else {
1590 /* State        Actions
1591  * ------------   ------------ ----------------        -------
1592  * EXCLUDE (X,Y)  IS_IN (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1593  */
1594 		/* Update (A) in (X, Y) as NONE/NEW */
1595 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1596 				    AMT_FILTER_BOTH,
1597 				    AMT_ACT_STATUS_NONE_NEW,
1598 				    v6);
1599 		/* Update FWD/OLD as FWD/NEW */
1600 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1601 				    AMT_FILTER_FWD,
1602 				    AMT_ACT_STATUS_FWD_NEW,
1603 				    v6);
1604 		/* Update IS_IN (A) as FWD/NEW */
1605 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1606 				    AMT_FILTER_NONE_NEW,
1607 				    AMT_ACT_STATUS_FWD_NEW,
1608 				    v6);
1609 		/* Update EXCLUDE (, Y-A) as D_FWD_NEW */
1610 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB,
1611 				    AMT_FILTER_D_FWD,
1612 				    AMT_ACT_STATUS_D_FWD_NEW,
1613 				    v6);
1614 	}
1615 }
1616 
1617 static void amt_mcast_is_ex_handler(struct amt_dev *amt,
1618 				    struct amt_tunnel_list *tunnel,
1619 				    struct amt_group_node *gnode,
1620 				    void *grec, void *zero_grec, bool v6)
1621 {
1622 	if (gnode->filter_mode == MCAST_INCLUDE) {
1623 /* Router State   Report Rec'd  New Router State         Actions
1624  * ------------   ------------  ----------------         -------
1625  * INCLUDE (A)    IS_EX (B)     EXCLUDE (A*B,B-A)        (B-A)=0
1626  *                                                       Delete (A-B)
1627  *                                                       Group Timer=GMI
1628  */
1629 		/* EXCLUDE(A*B, ) */
1630 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1631 				    AMT_FILTER_FWD,
1632 				    AMT_ACT_STATUS_FWD_NEW,
1633 				    v6);
1634 		/* EXCLUDE(, B-A) */
1635 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1636 				    AMT_FILTER_FWD,
1637 				    AMT_ACT_STATUS_D_FWD_NEW,
1638 				    v6);
1639 		/* (B-A)=0 */
1640 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1641 				    AMT_FILTER_D_FWD_NEW,
1642 				    AMT_ACT_GMI_ZERO,
1643 				    v6);
1644 		/* Group Timer=GMI */
1645 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1646 				      msecs_to_jiffies(amt_gmi(amt))))
1647 			dev_hold(amt->dev);
1648 		gnode->filter_mode = MCAST_EXCLUDE;
1649 		/* Delete (A-B) will be worked by amt_cleanup_srcs(). */
1650 	} else {
1651 /* Router State   Report Rec'd  New Router State	Actions
1652  * ------------   ------------  ----------------	-------
1653  * EXCLUDE (X,Y)  IS_EX (A)     EXCLUDE (A-Y,Y*A)	(A-X-Y)=GMI
1654  *							Delete (X-A)
1655  *							Delete (Y-A)
1656  *							Group Timer=GMI
1657  */
1658 		/* EXCLUDE (A-Y, ) */
1659 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1660 				    AMT_FILTER_D_FWD,
1661 				    AMT_ACT_STATUS_FWD_NEW,
1662 				    v6);
1663 		/* EXCLUDE (, Y*A ) */
1664 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1665 				    AMT_FILTER_D_FWD,
1666 				    AMT_ACT_STATUS_D_FWD_NEW,
1667 				    v6);
1668 		/* (A-X-Y)=GMI */
1669 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1670 				    AMT_FILTER_BOTH_NEW,
1671 				    AMT_ACT_GMI,
1672 				    v6);
1673 		/* Group Timer=GMI */
1674 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1675 				      msecs_to_jiffies(amt_gmi(amt))))
1676 			dev_hold(amt->dev);
1677 		/* Delete (X-A), (Y-A) will be worked by amt_cleanup_srcs(). */
1678 	}
1679 }
1680 
1681 static void amt_mcast_to_in_handler(struct amt_dev *amt,
1682 				    struct amt_tunnel_list *tunnel,
1683 				    struct amt_group_node *gnode,
1684 				    void *grec, void *zero_grec, bool v6)
1685 {
1686 	if (gnode->filter_mode == MCAST_INCLUDE) {
1687 /* Router State   Report Rec'd New Router State        Actions
1688  * ------------   ------------ ----------------        -------
1689  * INCLUDE (A)    TO_IN (B)    INCLUDE (A+B)           (B)=GMI
1690  *						       Send Q(G,A-B)
1691  */
1692 		/* Update TO_IN (B) sources as FWD/NEW */
1693 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1694 				    AMT_FILTER_NONE_NEW,
1695 				    AMT_ACT_STATUS_FWD_NEW,
1696 				    v6);
1697 		/* Update INCLUDE (A) sources as NEW */
1698 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1699 				    AMT_FILTER_FWD,
1700 				    AMT_ACT_STATUS_FWD_NEW,
1701 				    v6);
1702 		/* (B)=GMI */
1703 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1704 				    AMT_FILTER_FWD_NEW,
1705 				    AMT_ACT_GMI,
1706 				    v6);
1707 	} else {
1708 /* Router State   Report Rec'd New Router State        Actions
1709  * ------------   ------------ ----------------        -------
1710  * EXCLUDE (X,Y)  TO_IN (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1711  *						       Send Q(G,X-A)
1712  *						       Send Q(G)
1713  */
1714 		/* Update TO_IN (A) sources as FWD/NEW */
1715 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1716 				    AMT_FILTER_NONE_NEW,
1717 				    AMT_ACT_STATUS_FWD_NEW,
1718 				    v6);
1719 		/* Update EXCLUDE(X,) sources as FWD/NEW */
1720 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1721 				    AMT_FILTER_FWD,
1722 				    AMT_ACT_STATUS_FWD_NEW,
1723 				    v6);
1724 		/* EXCLUDE (, Y-A)
1725 		 * (A) are already switched to FWD_NEW.
1726 		 * So, D_FWD/OLD -> D_FWD/NEW is okay.
1727 		 */
1728 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1729 				    AMT_FILTER_D_FWD,
1730 				    AMT_ACT_STATUS_D_FWD_NEW,
1731 				    v6);
1732 		/* (A)=GMI
1733 		 * Only FWD_NEW will have (A) sources.
1734 		 */
1735 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1736 				    AMT_FILTER_FWD_NEW,
1737 				    AMT_ACT_GMI,
1738 				    v6);
1739 	}
1740 }
1741 
1742 static void amt_mcast_to_ex_handler(struct amt_dev *amt,
1743 				    struct amt_tunnel_list *tunnel,
1744 				    struct amt_group_node *gnode,
1745 				    void *grec, void *zero_grec, bool v6)
1746 {
1747 	if (gnode->filter_mode == MCAST_INCLUDE) {
1748 /* Router State   Report Rec'd New Router State        Actions
1749  * ------------   ------------ ----------------        -------
1750  * INCLUDE (A)    TO_EX (B)    EXCLUDE (A*B,B-A)       (B-A)=0
1751  *						       Delete (A-B)
1752  *						       Send Q(G,A*B)
1753  *						       Group Timer=GMI
1754  */
1755 		/* EXCLUDE (A*B, ) */
1756 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1757 				    AMT_FILTER_FWD,
1758 				    AMT_ACT_STATUS_FWD_NEW,
1759 				    v6);
1760 		/* EXCLUDE (, B-A) */
1761 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1762 				    AMT_FILTER_FWD,
1763 				    AMT_ACT_STATUS_D_FWD_NEW,
1764 				    v6);
1765 		/* (B-A)=0 */
1766 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1767 				    AMT_FILTER_D_FWD_NEW,
1768 				    AMT_ACT_GMI_ZERO,
1769 				    v6);
1770 		/* Group Timer=GMI */
1771 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1772 				      msecs_to_jiffies(amt_gmi(amt))))
1773 			dev_hold(amt->dev);
1774 		gnode->filter_mode = MCAST_EXCLUDE;
1775 		/* Delete (A-B) will be worked by amt_cleanup_srcs(). */
1776 	} else {
1777 /* Router State   Report Rec'd New Router State        Actions
1778  * ------------   ------------ ----------------        -------
1779  * EXCLUDE (X,Y)  TO_EX (A)    EXCLUDE (A-Y,Y*A)       (A-X-Y)=Group Timer
1780  *						       Delete (X-A)
1781  *						       Delete (Y-A)
1782  *						       Send Q(G,A-Y)
1783  *						       Group Timer=GMI
1784  */
1785 		/* Update (A-X-Y) as NONE/OLD */
1786 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1787 				    AMT_FILTER_BOTH,
1788 				    AMT_ACT_GT,
1789 				    v6);
1790 		/* EXCLUDE (A-Y, ) */
1791 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1792 				    AMT_FILTER_D_FWD,
1793 				    AMT_ACT_STATUS_FWD_NEW,
1794 				    v6);
1795 		/* EXCLUDE (, Y*A) */
1796 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1797 				    AMT_FILTER_D_FWD,
1798 				    AMT_ACT_STATUS_D_FWD_NEW,
1799 				    v6);
1800 		/* Group Timer=GMI */
1801 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1802 				      msecs_to_jiffies(amt_gmi(amt))))
1803 			dev_hold(amt->dev);
1804 		/* Delete (X-A), (Y-A) will be worked by amt_cleanup_srcs(). */
1805 	}
1806 }
1807 
1808 static void amt_mcast_allow_handler(struct amt_dev *amt,
1809 				    struct amt_tunnel_list *tunnel,
1810 				    struct amt_group_node *gnode,
1811 				    void *grec, void *zero_grec, bool v6)
1812 {
1813 	if (gnode->filter_mode == MCAST_INCLUDE) {
1814 /* Router State   Report Rec'd New Router State        Actions
1815  * ------------   ------------ ----------------        -------
1816  * INCLUDE (A)    ALLOW (B)    INCLUDE (A+B)	       (B)=GMI
1817  */
1818 		/* INCLUDE (A+B) */
1819 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1820 				    AMT_FILTER_FWD,
1821 				    AMT_ACT_STATUS_FWD_NEW,
1822 				    v6);
1823 		/* (B)=GMI */
1824 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1825 				    AMT_FILTER_FWD_NEW,
1826 				    AMT_ACT_GMI,
1827 				    v6);
1828 	} else {
1829 /* Router State   Report Rec'd New Router State        Actions
1830  * ------------   ------------ ----------------        -------
1831  * EXCLUDE (X,Y)  ALLOW (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1832  */
1833 		/* EXCLUDE (X+A, ) */
1834 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1835 				    AMT_FILTER_FWD,
1836 				    AMT_ACT_STATUS_FWD_NEW,
1837 				    v6);
1838 		/* EXCLUDE (, Y-A) */
1839 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB,
1840 				    AMT_FILTER_D_FWD,
1841 				    AMT_ACT_STATUS_D_FWD_NEW,
1842 				    v6);
1843 		/* (A)=GMI
1844 		 * All (A) source are now FWD/NEW status.
1845 		 */
1846 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1847 				    AMT_FILTER_FWD_NEW,
1848 				    AMT_ACT_GMI,
1849 				    v6);
1850 	}
1851 }
1852 
1853 static void amt_mcast_block_handler(struct amt_dev *amt,
1854 				    struct amt_tunnel_list *tunnel,
1855 				    struct amt_group_node *gnode,
1856 				    void *grec, void *zero_grec, bool v6)
1857 {
1858 	if (gnode->filter_mode == MCAST_INCLUDE) {
1859 /* Router State   Report Rec'd New Router State        Actions
1860  * ------------   ------------ ----------------        -------
1861  * INCLUDE (A)    BLOCK (B)    INCLUDE (A)             Send Q(G,A*B)
1862  */
1863 		/* INCLUDE (A) */
1864 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1865 				    AMT_FILTER_FWD,
1866 				    AMT_ACT_STATUS_FWD_NEW,
1867 				    v6);
1868 	} else {
1869 /* Router State   Report Rec'd New Router State        Actions
1870  * ------------   ------------ ----------------        -------
1871  * EXCLUDE (X,Y)  BLOCK (A)    EXCLUDE (X+(A-Y),Y)     (A-X-Y)=Group Timer
1872  *						       Send Q(G,A-Y)
1873  */
1874 		/* (A-X-Y)=Group Timer */
1875 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1876 				    AMT_FILTER_BOTH,
1877 				    AMT_ACT_GT,
1878 				    v6);
1879 		/* EXCLUDE (X, ) */
1880 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1881 				    AMT_FILTER_FWD,
1882 				    AMT_ACT_STATUS_FWD_NEW,
1883 				    v6);
1884 		/* EXCLUDE (X+(A-Y) */
1885 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1886 				    AMT_FILTER_D_FWD,
1887 				    AMT_ACT_STATUS_FWD_NEW,
1888 				    v6);
1889 		/* EXCLUDE (, Y) */
1890 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1891 				    AMT_FILTER_D_FWD,
1892 				    AMT_ACT_STATUS_D_FWD_NEW,
1893 				    v6);
1894 	}
1895 }
1896 
1897 /* RFC 3376
1898  * 7.3.2. In the Presence of Older Version Group Members
1899  *
1900  * When Group Compatibility Mode is IGMPv2, a router internally
1901  * translates the following IGMPv2 messages for that group to their
1902  * IGMPv3 equivalents:
1903  *
1904  * IGMPv2 Message                IGMPv3 Equivalent
1905  * --------------                -----------------
1906  * Report                        IS_EX( {} )
1907  * Leave                         TO_IN( {} )
1908  */
1909 static void amt_igmpv2_report_handler(struct amt_dev *amt, struct sk_buff *skb,
1910 				      struct amt_tunnel_list *tunnel)
1911 {
1912 	struct igmphdr *ih = igmp_hdr(skb);
1913 	struct iphdr *iph = ip_hdr(skb);
1914 	struct amt_group_node *gnode;
1915 	union amt_addr group, host;
1916 
1917 	memset(&group, 0, sizeof(union amt_addr));
1918 	group.ip4 = ih->group;
1919 	memset(&host, 0, sizeof(union amt_addr));
1920 	host.ip4 = iph->saddr;
1921 
1922 	gnode = amt_lookup_group(tunnel, &group, &host, false);
1923 	if (!gnode) {
1924 		gnode = amt_add_group(amt, tunnel, &group, &host, false);
1925 		if (!IS_ERR(gnode)) {
1926 			gnode->filter_mode = MCAST_EXCLUDE;
1927 			if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1928 					      msecs_to_jiffies(amt_gmi(amt))))
1929 				dev_hold(amt->dev);
1930 		}
1931 	}
1932 }
1933 
1934 /* RFC 3376
1935  * 7.3.2. In the Presence of Older Version Group Members
1936  *
1937  * When Group Compatibility Mode is IGMPv2, a router internally
1938  * translates the following IGMPv2 messages for that group to their
1939  * IGMPv3 equivalents:
1940  *
1941  * IGMPv2 Message                IGMPv3 Equivalent
1942  * --------------                -----------------
1943  * Report                        IS_EX( {} )
1944  * Leave                         TO_IN( {} )
1945  */
1946 static void amt_igmpv2_leave_handler(struct amt_dev *amt, struct sk_buff *skb,
1947 				     struct amt_tunnel_list *tunnel)
1948 {
1949 	struct igmphdr *ih = igmp_hdr(skb);
1950 	struct iphdr *iph = ip_hdr(skb);
1951 	struct amt_group_node *gnode;
1952 	union amt_addr group, host;
1953 
1954 	memset(&group, 0, sizeof(union amt_addr));
1955 	group.ip4 = ih->group;
1956 	memset(&host, 0, sizeof(union amt_addr));
1957 	host.ip4 = iph->saddr;
1958 
1959 	gnode = amt_lookup_group(tunnel, &group, &host, false);
1960 	if (gnode)
1961 		amt_del_group(amt, gnode);
1962 }
1963 
1964 static void amt_igmpv3_report_handler(struct amt_dev *amt, struct sk_buff *skb,
1965 				      struct amt_tunnel_list *tunnel)
1966 {
1967 	struct igmpv3_report *ihrv3 = igmpv3_report_hdr(skb);
1968 	int len = skb_transport_offset(skb) + sizeof(*ihrv3);
1969 	void *zero_grec = (void *)&igmpv3_zero_grec;
1970 	struct iphdr *iph = ip_hdr(skb);
1971 	struct amt_group_node *gnode;
1972 	union amt_addr group, host;
1973 	struct igmpv3_grec *grec;
1974 	u16 nsrcs;
1975 	int i;
1976 
1977 	for (i = 0; i < ntohs(ihrv3->ngrec); i++) {
1978 		len += sizeof(*grec);
1979 		if (!ip_mc_may_pull(skb, len))
1980 			break;
1981 
1982 		grec = (void *)(skb->data + len - sizeof(*grec));
1983 		nsrcs = ntohs(grec->grec_nsrcs);
1984 
1985 		len += nsrcs * sizeof(__be32);
1986 		if (!ip_mc_may_pull(skb, len))
1987 			break;
1988 
1989 		memset(&group, 0, sizeof(union amt_addr));
1990 		group.ip4 = grec->grec_mca;
1991 		memset(&host, 0, sizeof(union amt_addr));
1992 		host.ip4 = iph->saddr;
1993 		gnode = amt_lookup_group(tunnel, &group, &host, false);
1994 		if (!gnode) {
1995 			gnode = amt_add_group(amt, tunnel, &group, &host,
1996 					      false);
1997 			if (IS_ERR(gnode))
1998 				continue;
1999 		}
2000 
2001 		amt_add_srcs(amt, tunnel, gnode, grec, false);
2002 		switch (grec->grec_type) {
2003 		case IGMPV3_MODE_IS_INCLUDE:
2004 			amt_mcast_is_in_handler(amt, tunnel, gnode, grec,
2005 						zero_grec, false);
2006 			break;
2007 		case IGMPV3_MODE_IS_EXCLUDE:
2008 			amt_mcast_is_ex_handler(amt, tunnel, gnode, grec,
2009 						zero_grec, false);
2010 			break;
2011 		case IGMPV3_CHANGE_TO_INCLUDE:
2012 			amt_mcast_to_in_handler(amt, tunnel, gnode, grec,
2013 						zero_grec, false);
2014 			break;
2015 		case IGMPV3_CHANGE_TO_EXCLUDE:
2016 			amt_mcast_to_ex_handler(amt, tunnel, gnode, grec,
2017 						zero_grec, false);
2018 			break;
2019 		case IGMPV3_ALLOW_NEW_SOURCES:
2020 			amt_mcast_allow_handler(amt, tunnel, gnode, grec,
2021 						zero_grec, false);
2022 			break;
2023 		case IGMPV3_BLOCK_OLD_SOURCES:
2024 			amt_mcast_block_handler(amt, tunnel, gnode, grec,
2025 						zero_grec, false);
2026 			break;
2027 		default:
2028 			break;
2029 		}
2030 		amt_cleanup_srcs(amt, tunnel, gnode);
2031 	}
2032 }
2033 
2034 /* caller held tunnel->lock */
2035 static void amt_igmp_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2036 				    struct amt_tunnel_list *tunnel)
2037 {
2038 	struct igmphdr *ih = igmp_hdr(skb);
2039 
2040 	switch (ih->type) {
2041 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
2042 		amt_igmpv3_report_handler(amt, skb, tunnel);
2043 		break;
2044 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
2045 		amt_igmpv2_report_handler(amt, skb, tunnel);
2046 		break;
2047 	case IGMP_HOST_LEAVE_MESSAGE:
2048 		amt_igmpv2_leave_handler(amt, skb, tunnel);
2049 		break;
2050 	default:
2051 		break;
2052 	}
2053 }
2054 
2055 #if IS_ENABLED(CONFIG_IPV6)
2056 /* RFC 3810
2057  * 8.3.2. In the Presence of MLDv1 Multicast Address Listeners
2058  *
2059  * When Multicast Address Compatibility Mode is MLDv2, a router acts
2060  * using the MLDv2 protocol for that multicast address.  When Multicast
2061  * Address Compatibility Mode is MLDv1, a router internally translates
2062  * the following MLDv1 messages for that multicast address to their
2063  * MLDv2 equivalents:
2064  *
2065  * MLDv1 Message                 MLDv2 Equivalent
2066  * --------------                -----------------
2067  * Report                        IS_EX( {} )
2068  * Done                          TO_IN( {} )
2069  */
2070 static void amt_mldv1_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2071 				     struct amt_tunnel_list *tunnel)
2072 {
2073 	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2074 	struct ipv6hdr *ip6h = ipv6_hdr(skb);
2075 	struct amt_group_node *gnode;
2076 	union amt_addr group, host;
2077 
2078 	memcpy(&group.ip6, &mld->mld_mca, sizeof(struct in6_addr));
2079 	memcpy(&host.ip6, &ip6h->saddr, sizeof(struct in6_addr));
2080 
2081 	gnode = amt_lookup_group(tunnel, &group, &host, true);
2082 	if (!gnode) {
2083 		gnode = amt_add_group(amt, tunnel, &group, &host, true);
2084 		if (!IS_ERR(gnode)) {
2085 			gnode->filter_mode = MCAST_EXCLUDE;
2086 			if (!mod_delayed_work(amt_wq, &gnode->group_timer,
2087 					      msecs_to_jiffies(amt_gmi(amt))))
2088 				dev_hold(amt->dev);
2089 		}
2090 	}
2091 }
2092 
2093 /* RFC 3810
2094  * 8.3.2. In the Presence of MLDv1 Multicast Address Listeners
2095  *
2096  * When Multicast Address Compatibility Mode is MLDv2, a router acts
2097  * using the MLDv2 protocol for that multicast address.  When Multicast
2098  * Address Compatibility Mode is MLDv1, a router internally translates
2099  * the following MLDv1 messages for that multicast address to their
2100  * MLDv2 equivalents:
2101  *
2102  * MLDv1 Message                 MLDv2 Equivalent
2103  * --------------                -----------------
2104  * Report                        IS_EX( {} )
2105  * Done                          TO_IN( {} )
2106  */
2107 static void amt_mldv1_leave_handler(struct amt_dev *amt, struct sk_buff *skb,
2108 				    struct amt_tunnel_list *tunnel)
2109 {
2110 	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2111 	struct iphdr *iph = ip_hdr(skb);
2112 	struct amt_group_node *gnode;
2113 	union amt_addr group, host;
2114 
2115 	memcpy(&group.ip6, &mld->mld_mca, sizeof(struct in6_addr));
2116 	memset(&host, 0, sizeof(union amt_addr));
2117 	host.ip4 = iph->saddr;
2118 
2119 	gnode = amt_lookup_group(tunnel, &group, &host, true);
2120 	if (gnode) {
2121 		amt_del_group(amt, gnode);
2122 		return;
2123 	}
2124 }
2125 
2126 static void amt_mldv2_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2127 				     struct amt_tunnel_list *tunnel)
2128 {
2129 	struct mld2_report *mld2r = (struct mld2_report *)icmp6_hdr(skb);
2130 	int len = skb_transport_offset(skb) + sizeof(*mld2r);
2131 	void *zero_grec = (void *)&mldv2_zero_grec;
2132 	struct ipv6hdr *ip6h = ipv6_hdr(skb);
2133 	struct amt_group_node *gnode;
2134 	union amt_addr group, host;
2135 	struct mld2_grec *grec;
2136 	u16 nsrcs;
2137 	int i;
2138 
2139 	for (i = 0; i < ntohs(mld2r->mld2r_ngrec); i++) {
2140 		len += sizeof(*grec);
2141 		if (!ipv6_mc_may_pull(skb, len))
2142 			break;
2143 
2144 		grec = (void *)(skb->data + len - sizeof(*grec));
2145 		nsrcs = ntohs(grec->grec_nsrcs);
2146 
2147 		len += nsrcs * sizeof(struct in6_addr);
2148 		if (!ipv6_mc_may_pull(skb, len))
2149 			break;
2150 
2151 		memset(&group, 0, sizeof(union amt_addr));
2152 		group.ip6 = grec->grec_mca;
2153 		memset(&host, 0, sizeof(union amt_addr));
2154 		host.ip6 = ip6h->saddr;
2155 		gnode = amt_lookup_group(tunnel, &group, &host, true);
2156 		if (!gnode) {
2157 			gnode = amt_add_group(amt, tunnel, &group, &host,
2158 					      ETH_P_IPV6);
2159 			if (IS_ERR(gnode))
2160 				continue;
2161 		}
2162 
2163 		amt_add_srcs(amt, tunnel, gnode, grec, true);
2164 		switch (grec->grec_type) {
2165 		case MLD2_MODE_IS_INCLUDE:
2166 			amt_mcast_is_in_handler(amt, tunnel, gnode, grec,
2167 						zero_grec, true);
2168 			break;
2169 		case MLD2_MODE_IS_EXCLUDE:
2170 			amt_mcast_is_ex_handler(amt, tunnel, gnode, grec,
2171 						zero_grec, true);
2172 			break;
2173 		case MLD2_CHANGE_TO_INCLUDE:
2174 			amt_mcast_to_in_handler(amt, tunnel, gnode, grec,
2175 						zero_grec, true);
2176 			break;
2177 		case MLD2_CHANGE_TO_EXCLUDE:
2178 			amt_mcast_to_ex_handler(amt, tunnel, gnode, grec,
2179 						zero_grec, true);
2180 			break;
2181 		case MLD2_ALLOW_NEW_SOURCES:
2182 			amt_mcast_allow_handler(amt, tunnel, gnode, grec,
2183 						zero_grec, true);
2184 			break;
2185 		case MLD2_BLOCK_OLD_SOURCES:
2186 			amt_mcast_block_handler(amt, tunnel, gnode, grec,
2187 						zero_grec, true);
2188 			break;
2189 		default:
2190 			break;
2191 		}
2192 		amt_cleanup_srcs(amt, tunnel, gnode);
2193 	}
2194 }
2195 
2196 /* caller held tunnel->lock */
2197 static void amt_mld_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2198 				   struct amt_tunnel_list *tunnel)
2199 {
2200 	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2201 
2202 	switch (mld->mld_type) {
2203 	case ICMPV6_MGM_REPORT:
2204 		amt_mldv1_report_handler(amt, skb, tunnel);
2205 		break;
2206 	case ICMPV6_MLD2_REPORT:
2207 		amt_mldv2_report_handler(amt, skb, tunnel);
2208 		break;
2209 	case ICMPV6_MGM_REDUCTION:
2210 		amt_mldv1_leave_handler(amt, skb, tunnel);
2211 		break;
2212 	default:
2213 		break;
2214 	}
2215 }
2216 #endif
2217 
2218 static bool amt_advertisement_handler(struct amt_dev *amt, struct sk_buff *skb)
2219 {
2220 	struct amt_header_advertisement *amta;
2221 	int hdr_size;
2222 
2223 	hdr_size = sizeof(*amta) - sizeof(struct amt_header);
2224 
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 	amtmd = (struct amt_header_mcast_data *)(udp_hdr(skb) + 1);
2255 	if (amtmd->reserved || amtmd->version)
2256 		return true;
2257 
2258 	hdr_size = sizeof(*amtmd) + sizeof(struct udphdr);
2259 	if (iptunnel_pull_header(skb, hdr_size, htons(ETH_P_IP), false))
2260 		return true;
2261 	skb_reset_network_header(skb);
2262 	skb_push(skb, sizeof(*eth));
2263 	skb_reset_mac_header(skb);
2264 	skb_pull(skb, sizeof(*eth));
2265 	eth = eth_hdr(skb);
2266 	iph = ip_hdr(skb);
2267 	if (iph->version == 4) {
2268 		if (!ipv4_is_multicast(iph->daddr))
2269 			return true;
2270 		skb->protocol = htons(ETH_P_IP);
2271 		eth->h_proto = htons(ETH_P_IP);
2272 		ip_eth_mc_map(iph->daddr, eth->h_dest);
2273 #if IS_ENABLED(CONFIG_IPV6)
2274 	} else if (iph->version == 6) {
2275 		struct ipv6hdr *ip6h;
2276 
2277 		ip6h = ipv6_hdr(skb);
2278 		if (!ipv6_addr_is_multicast(&ip6h->daddr))
2279 			return true;
2280 		skb->protocol = htons(ETH_P_IPV6);
2281 		eth->h_proto = htons(ETH_P_IPV6);
2282 		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2283 #endif
2284 	} else {
2285 		return true;
2286 	}
2287 
2288 	skb->pkt_type = PACKET_MULTICAST;
2289 	skb->ip_summed = CHECKSUM_NONE;
2290 	len = skb->len;
2291 	err = gro_cells_receive(&amt->gro_cells, skb);
2292 	if (likely(err == NET_RX_SUCCESS))
2293 		dev_sw_netstats_rx_add(amt->dev, len);
2294 	else
2295 		amt->dev->stats.rx_dropped++;
2296 
2297 	return false;
2298 }
2299 
2300 static bool amt_membership_query_handler(struct amt_dev *amt,
2301 					 struct sk_buff *skb)
2302 {
2303 	struct amt_header_membership_query *amtmq;
2304 	struct igmpv3_query *ihv3;
2305 	struct ethhdr *eth, *oeth;
2306 	struct iphdr *iph;
2307 	int hdr_size, len;
2308 
2309 	hdr_size = sizeof(*amtmq) - sizeof(struct amt_header);
2310 
2311 	if (!pskb_may_pull(skb, hdr_size))
2312 		return true;
2313 
2314 	amtmq = (struct amt_header_membership_query *)(udp_hdr(skb) + 1);
2315 	if (amtmq->reserved || amtmq->version)
2316 		return true;
2317 
2318 	hdr_size = sizeof(*amtmq) + sizeof(struct udphdr) - sizeof(*eth);
2319 	if (iptunnel_pull_header(skb, hdr_size, htons(ETH_P_TEB), false))
2320 		return true;
2321 	oeth = eth_hdr(skb);
2322 	skb_reset_mac_header(skb);
2323 	skb_pull(skb, sizeof(*eth));
2324 	skb_reset_network_header(skb);
2325 	eth = eth_hdr(skb);
2326 	iph = ip_hdr(skb);
2327 	if (iph->version == 4) {
2328 		if (!ipv4_is_multicast(iph->daddr))
2329 			return true;
2330 		if (!pskb_may_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS +
2331 				   sizeof(*ihv3)))
2332 			return true;
2333 
2334 		ihv3 = skb_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
2335 		skb_reset_transport_header(skb);
2336 		skb_push(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
2337 		spin_lock_bh(&amt->lock);
2338 		amt->ready4 = true;
2339 		amt->mac = amtmq->response_mac;
2340 		amt->req_cnt = 0;
2341 		amt->qi = ihv3->qqic;
2342 		spin_unlock_bh(&amt->lock);
2343 		skb->protocol = htons(ETH_P_IP);
2344 		eth->h_proto = htons(ETH_P_IP);
2345 		ip_eth_mc_map(iph->daddr, eth->h_dest);
2346 #if IS_ENABLED(CONFIG_IPV6)
2347 	} else if (iph->version == 6) {
2348 		struct ipv6hdr *ip6h = ipv6_hdr(skb);
2349 		struct mld2_query *mld2q;
2350 
2351 		if (!ipv6_addr_is_multicast(&ip6h->daddr))
2352 			return true;
2353 		if (!pskb_may_pull(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS +
2354 				   sizeof(*mld2q)))
2355 			return true;
2356 
2357 		mld2q = skb_pull(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS);
2358 		skb_reset_transport_header(skb);
2359 		skb_push(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS);
2360 		spin_lock_bh(&amt->lock);
2361 		amt->ready6 = true;
2362 		amt->mac = amtmq->response_mac;
2363 		amt->req_cnt = 0;
2364 		amt->qi = mld2q->mld2q_qqic;
2365 		spin_unlock_bh(&amt->lock);
2366 		skb->protocol = htons(ETH_P_IPV6);
2367 		eth->h_proto = htons(ETH_P_IPV6);
2368 		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2369 #endif
2370 	} else {
2371 		return true;
2372 	}
2373 
2374 	ether_addr_copy(eth->h_source, oeth->h_source);
2375 	skb->pkt_type = PACKET_MULTICAST;
2376 	skb->ip_summed = CHECKSUM_NONE;
2377 	len = skb->len;
2378 	if (__netif_rx(skb) == NET_RX_SUCCESS) {
2379 		amt_update_gw_status(amt, AMT_STATUS_RECEIVED_QUERY, true);
2380 		dev_sw_netstats_rx_add(amt->dev, len);
2381 	} else {
2382 		amt->dev->stats.rx_dropped++;
2383 	}
2384 
2385 	return false;
2386 }
2387 
2388 static bool amt_update_handler(struct amt_dev *amt, struct sk_buff *skb)
2389 {
2390 	struct amt_header_membership_update *amtmu;
2391 	struct amt_tunnel_list *tunnel;
2392 	struct udphdr *udph;
2393 	struct ethhdr *eth;
2394 	struct iphdr *iph;
2395 	int len;
2396 
2397 	iph = ip_hdr(skb);
2398 	udph = udp_hdr(skb);
2399 
2400 	if (__iptunnel_pull_header(skb, sizeof(*udph), skb->protocol,
2401 				   false, false))
2402 		return true;
2403 
2404 	amtmu = (struct amt_header_membership_update *)skb->data;
2405 	if (amtmu->reserved || amtmu->version)
2406 		return true;
2407 
2408 	skb_pull(skb, sizeof(*amtmu));
2409 	skb_reset_network_header(skb);
2410 
2411 	list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list) {
2412 		if (tunnel->ip4 == iph->saddr) {
2413 			if ((amtmu->nonce == tunnel->nonce &&
2414 			     amtmu->response_mac == tunnel->mac)) {
2415 				mod_delayed_work(amt_wq, &tunnel->gc_wq,
2416 						 msecs_to_jiffies(amt_gmi(amt))
2417 								  * 3);
2418 				goto report;
2419 			} else {
2420 				netdev_dbg(amt->dev, "Invalid MAC\n");
2421 				return true;
2422 			}
2423 		}
2424 	}
2425 
2426 	return true;
2427 
2428 report:
2429 	iph = ip_hdr(skb);
2430 	if (iph->version == 4) {
2431 		if (ip_mc_check_igmp(skb)) {
2432 			netdev_dbg(amt->dev, "Invalid IGMP\n");
2433 			return true;
2434 		}
2435 
2436 		spin_lock_bh(&tunnel->lock);
2437 		amt_igmp_report_handler(amt, skb, tunnel);
2438 		spin_unlock_bh(&tunnel->lock);
2439 
2440 		skb_push(skb, sizeof(struct ethhdr));
2441 		skb_reset_mac_header(skb);
2442 		eth = eth_hdr(skb);
2443 		skb->protocol = htons(ETH_P_IP);
2444 		eth->h_proto = htons(ETH_P_IP);
2445 		ip_eth_mc_map(iph->daddr, eth->h_dest);
2446 #if IS_ENABLED(CONFIG_IPV6)
2447 	} else if (iph->version == 6) {
2448 		struct ipv6hdr *ip6h = ipv6_hdr(skb);
2449 
2450 		if (ipv6_mc_check_mld(skb)) {
2451 			netdev_dbg(amt->dev, "Invalid MLD\n");
2452 			return true;
2453 		}
2454 
2455 		spin_lock_bh(&tunnel->lock);
2456 		amt_mld_report_handler(amt, skb, tunnel);
2457 		spin_unlock_bh(&tunnel->lock);
2458 
2459 		skb_push(skb, sizeof(struct ethhdr));
2460 		skb_reset_mac_header(skb);
2461 		eth = eth_hdr(skb);
2462 		skb->protocol = htons(ETH_P_IPV6);
2463 		eth->h_proto = htons(ETH_P_IPV6);
2464 		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2465 #endif
2466 	} else {
2467 		netdev_dbg(amt->dev, "Unsupported Protocol\n");
2468 		return true;
2469 	}
2470 
2471 	skb_pull(skb, sizeof(struct ethhdr));
2472 	skb->pkt_type = PACKET_MULTICAST;
2473 	skb->ip_summed = CHECKSUM_NONE;
2474 	len = skb->len;
2475 	if (__netif_rx(skb) == NET_RX_SUCCESS) {
2476 		amt_update_relay_status(tunnel, AMT_STATUS_RECEIVED_UPDATE,
2477 					true);
2478 		dev_sw_netstats_rx_add(amt->dev, len);
2479 	} else {
2480 		amt->dev->stats.rx_dropped++;
2481 	}
2482 
2483 	return false;
2484 }
2485 
2486 static void amt_send_advertisement(struct amt_dev *amt, __be32 nonce,
2487 				   __be32 daddr, __be16 dport)
2488 {
2489 	struct amt_header_advertisement *amta;
2490 	int hlen, tlen, offset;
2491 	struct socket *sock;
2492 	struct udphdr *udph;
2493 	struct sk_buff *skb;
2494 	struct iphdr *iph;
2495 	struct rtable *rt;
2496 	struct flowi4 fl4;
2497 	u32 len;
2498 	int err;
2499 
2500 	rcu_read_lock();
2501 	sock = rcu_dereference(amt->sock);
2502 	if (!sock)
2503 		goto out;
2504 
2505 	if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
2506 		goto out;
2507 
2508 	rt = ip_route_output_ports(amt->net, &fl4, sock->sk,
2509 				   daddr, amt->local_ip,
2510 				   dport, amt->relay_port,
2511 				   IPPROTO_UDP, 0,
2512 				   amt->stream_dev->ifindex);
2513 	if (IS_ERR(rt)) {
2514 		amt->dev->stats.tx_errors++;
2515 		goto out;
2516 	}
2517 
2518 	hlen = LL_RESERVED_SPACE(amt->dev);
2519 	tlen = amt->dev->needed_tailroom;
2520 	len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amta);
2521 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
2522 	if (!skb) {
2523 		ip_rt_put(rt);
2524 		amt->dev->stats.tx_errors++;
2525 		goto out;
2526 	}
2527 
2528 	skb->priority = TC_PRIO_CONTROL;
2529 	skb_dst_set(skb, &rt->dst);
2530 
2531 	len = sizeof(*iph) + sizeof(*udph) + sizeof(*amta);
2532 	skb_reset_network_header(skb);
2533 	skb_put(skb, len);
2534 	amta = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
2535 	amta->version	= 0;
2536 	amta->type	= AMT_MSG_ADVERTISEMENT;
2537 	amta->reserved	= 0;
2538 	amta->nonce	= nonce;
2539 	amta->ip4	= amt->local_ip;
2540 	skb_push(skb, sizeof(*udph));
2541 	skb_reset_transport_header(skb);
2542 	udph		= udp_hdr(skb);
2543 	udph->source	= amt->relay_port;
2544 	udph->dest	= dport;
2545 	udph->len	= htons(sizeof(*amta) + sizeof(*udph));
2546 	udph->check	= 0;
2547 	offset = skb_transport_offset(skb);
2548 	skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
2549 	udph->check = csum_tcpudp_magic(amt->local_ip, daddr,
2550 					sizeof(*udph) + sizeof(*amta),
2551 					IPPROTO_UDP, skb->csum);
2552 
2553 	skb_push(skb, sizeof(*iph));
2554 	iph		= ip_hdr(skb);
2555 	iph->version	= 4;
2556 	iph->ihl	= (sizeof(struct iphdr)) >> 2;
2557 	iph->tos	= AMT_TOS;
2558 	iph->frag_off	= 0;
2559 	iph->ttl	= ip4_dst_hoplimit(&rt->dst);
2560 	iph->daddr	= daddr;
2561 	iph->saddr	= amt->local_ip;
2562 	iph->protocol	= IPPROTO_UDP;
2563 	iph->tot_len	= htons(len);
2564 
2565 	skb->ip_summed = CHECKSUM_NONE;
2566 	ip_select_ident(amt->net, skb, NULL);
2567 	ip_send_check(iph);
2568 	err = ip_local_out(amt->net, sock->sk, skb);
2569 	if (unlikely(net_xmit_eval(err)))
2570 		amt->dev->stats.tx_errors++;
2571 
2572 out:
2573 	rcu_read_unlock();
2574 }
2575 
2576 static bool amt_discovery_handler(struct amt_dev *amt, struct sk_buff *skb)
2577 {
2578 	struct amt_header_discovery *amtd;
2579 	struct udphdr *udph;
2580 	struct iphdr *iph;
2581 
2582 	if (!pskb_may_pull(skb, sizeof(*udph) + sizeof(*amtd)))
2583 		return true;
2584 
2585 	iph = ip_hdr(skb);
2586 	udph = udp_hdr(skb);
2587 	amtd = (struct amt_header_discovery *)(udp_hdr(skb) + 1);
2588 
2589 	if (amtd->reserved || amtd->version)
2590 		return true;
2591 
2592 	amt_send_advertisement(amt, amtd->nonce, iph->saddr, udph->source);
2593 
2594 	return false;
2595 }
2596 
2597 static bool amt_request_handler(struct amt_dev *amt, struct sk_buff *skb)
2598 {
2599 	struct amt_header_request *amtrh;
2600 	struct amt_tunnel_list *tunnel;
2601 	unsigned long long key;
2602 	struct udphdr *udph;
2603 	struct iphdr *iph;
2604 	u64 mac;
2605 	int i;
2606 
2607 	if (!pskb_may_pull(skb, sizeof(*udph) + sizeof(*amtrh)))
2608 		return true;
2609 
2610 	iph = ip_hdr(skb);
2611 	udph = udp_hdr(skb);
2612 	amtrh = (struct amt_header_request *)(udp_hdr(skb) + 1);
2613 
2614 	if (amtrh->reserved1 || amtrh->reserved2 || amtrh->version)
2615 		return true;
2616 
2617 	list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list)
2618 		if (tunnel->ip4 == iph->saddr)
2619 			goto send;
2620 
2621 	if (amt->nr_tunnels >= amt->max_tunnels) {
2622 		icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
2623 		return true;
2624 	}
2625 
2626 	tunnel = kzalloc(sizeof(*tunnel) +
2627 			 (sizeof(struct hlist_head) * amt->hash_buckets),
2628 			 GFP_ATOMIC);
2629 	if (!tunnel)
2630 		return true;
2631 
2632 	tunnel->source_port = udph->source;
2633 	tunnel->ip4 = iph->saddr;
2634 
2635 	memcpy(&key, &tunnel->key, sizeof(unsigned long long));
2636 	tunnel->amt = amt;
2637 	spin_lock_init(&tunnel->lock);
2638 	for (i = 0; i < amt->hash_buckets; i++)
2639 		INIT_HLIST_HEAD(&tunnel->groups[i]);
2640 
2641 	INIT_DELAYED_WORK(&tunnel->gc_wq, amt_tunnel_expire);
2642 
2643 	spin_lock_bh(&amt->lock);
2644 	list_add_tail_rcu(&tunnel->list, &amt->tunnel_list);
2645 	tunnel->key = amt->key;
2646 	amt_update_relay_status(tunnel, AMT_STATUS_RECEIVED_REQUEST, true);
2647 	amt->nr_tunnels++;
2648 	mod_delayed_work(amt_wq, &tunnel->gc_wq,
2649 			 msecs_to_jiffies(amt_gmi(amt)));
2650 	spin_unlock_bh(&amt->lock);
2651 
2652 send:
2653 	tunnel->nonce = amtrh->nonce;
2654 	mac = siphash_3u32((__force u32)tunnel->ip4,
2655 			   (__force u32)tunnel->source_port,
2656 			   (__force u32)tunnel->nonce,
2657 			   &tunnel->key);
2658 	tunnel->mac = mac >> 16;
2659 
2660 	if (!netif_running(amt->dev) || !netif_running(amt->stream_dev))
2661 		return true;
2662 
2663 	if (!amtrh->p)
2664 		amt_send_igmp_gq(amt, tunnel);
2665 	else
2666 		amt_send_mld_gq(amt, tunnel);
2667 
2668 	return false;
2669 }
2670 
2671 static int amt_rcv(struct sock *sk, struct sk_buff *skb)
2672 {
2673 	struct amt_dev *amt;
2674 	struct iphdr *iph;
2675 	int type;
2676 	bool err;
2677 
2678 	rcu_read_lock_bh();
2679 	amt = rcu_dereference_sk_user_data(sk);
2680 	if (!amt) {
2681 		err = true;
2682 		goto drop;
2683 	}
2684 
2685 	skb->dev = amt->dev;
2686 	iph = ip_hdr(skb);
2687 	type = amt_parse_type(skb);
2688 	if (type == -1) {
2689 		err = true;
2690 		goto drop;
2691 	}
2692 
2693 	if (amt->mode == AMT_MODE_GATEWAY) {
2694 		switch (type) {
2695 		case AMT_MSG_ADVERTISEMENT:
2696 			if (iph->saddr != amt->discovery_ip) {
2697 				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2698 				err = true;
2699 				goto drop;
2700 			}
2701 			err = amt_advertisement_handler(amt, skb);
2702 			break;
2703 		case AMT_MSG_MULTICAST_DATA:
2704 			if (iph->saddr != amt->remote_ip) {
2705 				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2706 				err = true;
2707 				goto drop;
2708 			}
2709 			err = amt_multicast_data_handler(amt, skb);
2710 			if (err)
2711 				goto drop;
2712 			else
2713 				goto out;
2714 		case AMT_MSG_MEMBERSHIP_QUERY:
2715 			if (iph->saddr != amt->remote_ip) {
2716 				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2717 				err = true;
2718 				goto drop;
2719 			}
2720 			err = amt_membership_query_handler(amt, skb);
2721 			if (err)
2722 				goto drop;
2723 			else
2724 				goto out;
2725 		default:
2726 			err = true;
2727 			netdev_dbg(amt->dev, "Invalid type of Gateway\n");
2728 			break;
2729 		}
2730 	} else {
2731 		switch (type) {
2732 		case AMT_MSG_DISCOVERY:
2733 			err = amt_discovery_handler(amt, skb);
2734 			break;
2735 		case AMT_MSG_REQUEST:
2736 			err = amt_request_handler(amt, skb);
2737 			break;
2738 		case AMT_MSG_MEMBERSHIP_UPDATE:
2739 			err = amt_update_handler(amt, skb);
2740 			if (err)
2741 				goto drop;
2742 			else
2743 				goto out;
2744 		default:
2745 			err = true;
2746 			netdev_dbg(amt->dev, "Invalid type of relay\n");
2747 			break;
2748 		}
2749 	}
2750 drop:
2751 	if (err) {
2752 		amt->dev->stats.rx_dropped++;
2753 		kfree_skb(skb);
2754 	} else {
2755 		consume_skb(skb);
2756 	}
2757 out:
2758 	rcu_read_unlock_bh();
2759 	return 0;
2760 }
2761 
2762 static int amt_err_lookup(struct sock *sk, struct sk_buff *skb)
2763 {
2764 	struct amt_dev *amt;
2765 	int type;
2766 
2767 	rcu_read_lock_bh();
2768 	amt = rcu_dereference_sk_user_data(sk);
2769 	if (!amt)
2770 		goto out;
2771 
2772 	if (amt->mode != AMT_MODE_GATEWAY)
2773 		goto drop;
2774 
2775 	type = amt_parse_type(skb);
2776 	if (type == -1)
2777 		goto drop;
2778 
2779 	netdev_dbg(amt->dev, "Received IGMP Unreachable of %s\n",
2780 		   type_str[type]);
2781 	switch (type) {
2782 	case AMT_MSG_DISCOVERY:
2783 		break;
2784 	case AMT_MSG_REQUEST:
2785 	case AMT_MSG_MEMBERSHIP_UPDATE:
2786 		if (amt->status >= AMT_STATUS_RECEIVED_ADVERTISEMENT)
2787 			mod_delayed_work(amt_wq, &amt->req_wq, 0);
2788 		break;
2789 	default:
2790 		goto drop;
2791 	}
2792 out:
2793 	rcu_read_unlock_bh();
2794 	return 0;
2795 drop:
2796 	rcu_read_unlock_bh();
2797 	amt->dev->stats.rx_dropped++;
2798 	return 0;
2799 }
2800 
2801 static struct socket *amt_create_sock(struct net *net, __be16 port)
2802 {
2803 	struct udp_port_cfg udp_conf;
2804 	struct socket *sock;
2805 	int err;
2806 
2807 	memset(&udp_conf, 0, sizeof(udp_conf));
2808 	udp_conf.family = AF_INET;
2809 	udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
2810 
2811 	udp_conf.local_udp_port = port;
2812 
2813 	err = udp_sock_create(net, &udp_conf, &sock);
2814 	if (err < 0)
2815 		return ERR_PTR(err);
2816 
2817 	return sock;
2818 }
2819 
2820 static int amt_socket_create(struct amt_dev *amt)
2821 {
2822 	struct udp_tunnel_sock_cfg tunnel_cfg;
2823 	struct socket *sock;
2824 
2825 	sock = amt_create_sock(amt->net, amt->relay_port);
2826 	if (IS_ERR(sock))
2827 		return PTR_ERR(sock);
2828 
2829 	/* Mark socket as an encapsulation socket */
2830 	memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
2831 	tunnel_cfg.sk_user_data = amt;
2832 	tunnel_cfg.encap_type = 1;
2833 	tunnel_cfg.encap_rcv = amt_rcv;
2834 	tunnel_cfg.encap_err_lookup = amt_err_lookup;
2835 	tunnel_cfg.encap_destroy = NULL;
2836 	setup_udp_tunnel_sock(amt->net, sock, &tunnel_cfg);
2837 
2838 	rcu_assign_pointer(amt->sock, sock);
2839 	return 0;
2840 }
2841 
2842 static int amt_dev_open(struct net_device *dev)
2843 {
2844 	struct amt_dev *amt = netdev_priv(dev);
2845 	int err;
2846 
2847 	amt->ready4 = false;
2848 	amt->ready6 = false;
2849 
2850 	err = amt_socket_create(amt);
2851 	if (err)
2852 		return err;
2853 
2854 	amt->req_cnt = 0;
2855 	amt->remote_ip = 0;
2856 	get_random_bytes(&amt->key, sizeof(siphash_key_t));
2857 
2858 	amt->status = AMT_STATUS_INIT;
2859 	if (amt->mode == AMT_MODE_GATEWAY) {
2860 		mod_delayed_work(amt_wq, &amt->discovery_wq, 0);
2861 		mod_delayed_work(amt_wq, &amt->req_wq, 0);
2862 	} else if (amt->mode == AMT_MODE_RELAY) {
2863 		mod_delayed_work(amt_wq, &amt->secret_wq,
2864 				 msecs_to_jiffies(AMT_SECRET_TIMEOUT));
2865 	}
2866 	return err;
2867 }
2868 
2869 static int amt_dev_stop(struct net_device *dev)
2870 {
2871 	struct amt_dev *amt = netdev_priv(dev);
2872 	struct amt_tunnel_list *tunnel, *tmp;
2873 	struct socket *sock;
2874 
2875 	cancel_delayed_work_sync(&amt->req_wq);
2876 	cancel_delayed_work_sync(&amt->discovery_wq);
2877 	cancel_delayed_work_sync(&amt->secret_wq);
2878 
2879 	/* shutdown */
2880 	sock = rtnl_dereference(amt->sock);
2881 	RCU_INIT_POINTER(amt->sock, NULL);
2882 	synchronize_net();
2883 	if (sock)
2884 		udp_tunnel_sock_release(sock);
2885 
2886 	amt->ready4 = false;
2887 	amt->ready6 = false;
2888 	amt->req_cnt = 0;
2889 	amt->remote_ip = 0;
2890 
2891 	list_for_each_entry_safe(tunnel, tmp, &amt->tunnel_list, list) {
2892 		list_del_rcu(&tunnel->list);
2893 		amt->nr_tunnels--;
2894 		cancel_delayed_work_sync(&tunnel->gc_wq);
2895 		amt_clear_groups(tunnel);
2896 		kfree_rcu(tunnel, rcu);
2897 	}
2898 
2899 	return 0;
2900 }
2901 
2902 static const struct device_type amt_type = {
2903 	.name = "amt",
2904 };
2905 
2906 static int amt_dev_init(struct net_device *dev)
2907 {
2908 	struct amt_dev *amt = netdev_priv(dev);
2909 	int err;
2910 
2911 	amt->dev = dev;
2912 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
2913 	if (!dev->tstats)
2914 		return -ENOMEM;
2915 
2916 	err = gro_cells_init(&amt->gro_cells, dev);
2917 	if (err) {
2918 		free_percpu(dev->tstats);
2919 		return err;
2920 	}
2921 
2922 	return 0;
2923 }
2924 
2925 static void amt_dev_uninit(struct net_device *dev)
2926 {
2927 	struct amt_dev *amt = netdev_priv(dev);
2928 
2929 	gro_cells_destroy(&amt->gro_cells);
2930 	free_percpu(dev->tstats);
2931 }
2932 
2933 static const struct net_device_ops amt_netdev_ops = {
2934 	.ndo_init               = amt_dev_init,
2935 	.ndo_uninit             = amt_dev_uninit,
2936 	.ndo_open		= amt_dev_open,
2937 	.ndo_stop		= amt_dev_stop,
2938 	.ndo_start_xmit         = amt_dev_xmit,
2939 	.ndo_get_stats64        = dev_get_tstats64,
2940 };
2941 
2942 static void amt_link_setup(struct net_device *dev)
2943 {
2944 	dev->netdev_ops         = &amt_netdev_ops;
2945 	dev->needs_free_netdev  = true;
2946 	SET_NETDEV_DEVTYPE(dev, &amt_type);
2947 	dev->min_mtu		= ETH_MIN_MTU;
2948 	dev->max_mtu		= ETH_MAX_MTU;
2949 	dev->type		= ARPHRD_NONE;
2950 	dev->flags		= IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
2951 	dev->hard_header_len	= 0;
2952 	dev->addr_len		= 0;
2953 	dev->priv_flags		|= IFF_NO_QUEUE;
2954 	dev->features		|= NETIF_F_LLTX;
2955 	dev->features		|= NETIF_F_GSO_SOFTWARE;
2956 	dev->features		|= NETIF_F_NETNS_LOCAL;
2957 	dev->hw_features	|= NETIF_F_SG | NETIF_F_HW_CSUM;
2958 	dev->hw_features	|= NETIF_F_FRAGLIST | NETIF_F_RXCSUM;
2959 	dev->hw_features	|= NETIF_F_GSO_SOFTWARE;
2960 	eth_hw_addr_random(dev);
2961 	eth_zero_addr(dev->broadcast);
2962 	ether_setup(dev);
2963 }
2964 
2965 static const struct nla_policy amt_policy[IFLA_AMT_MAX + 1] = {
2966 	[IFLA_AMT_MODE]		= { .type = NLA_U32 },
2967 	[IFLA_AMT_RELAY_PORT]	= { .type = NLA_U16 },
2968 	[IFLA_AMT_GATEWAY_PORT]	= { .type = NLA_U16 },
2969 	[IFLA_AMT_LINK]		= { .type = NLA_U32 },
2970 	[IFLA_AMT_LOCAL_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
2971 	[IFLA_AMT_REMOTE_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
2972 	[IFLA_AMT_DISCOVERY_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
2973 	[IFLA_AMT_MAX_TUNNELS]	= { .type = NLA_U32 },
2974 };
2975 
2976 static int amt_validate(struct nlattr *tb[], struct nlattr *data[],
2977 			struct netlink_ext_ack *extack)
2978 {
2979 	if (!data)
2980 		return -EINVAL;
2981 
2982 	if (!data[IFLA_AMT_LINK]) {
2983 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_LINK],
2984 				    "Link attribute is required");
2985 		return -EINVAL;
2986 	}
2987 
2988 	if (!data[IFLA_AMT_MODE]) {
2989 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_MODE],
2990 				    "Mode attribute is required");
2991 		return -EINVAL;
2992 	}
2993 
2994 	if (nla_get_u32(data[IFLA_AMT_MODE]) > AMT_MODE_MAX) {
2995 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_MODE],
2996 				    "Mode attribute is not valid");
2997 		return -EINVAL;
2998 	}
2999 
3000 	if (!data[IFLA_AMT_LOCAL_IP]) {
3001 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_DISCOVERY_IP],
3002 				    "Local attribute is required");
3003 		return -EINVAL;
3004 	}
3005 
3006 	if (!data[IFLA_AMT_DISCOVERY_IP] &&
3007 	    nla_get_u32(data[IFLA_AMT_MODE]) == AMT_MODE_GATEWAY) {
3008 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_LOCAL_IP],
3009 				    "Discovery attribute is required");
3010 		return -EINVAL;
3011 	}
3012 
3013 	return 0;
3014 }
3015 
3016 static int amt_newlink(struct net *net, struct net_device *dev,
3017 		       struct nlattr *tb[], struct nlattr *data[],
3018 		       struct netlink_ext_ack *extack)
3019 {
3020 	struct amt_dev *amt = netdev_priv(dev);
3021 	int err = -EINVAL;
3022 
3023 	amt->net = net;
3024 	amt->mode = nla_get_u32(data[IFLA_AMT_MODE]);
3025 
3026 	if (data[IFLA_AMT_MAX_TUNNELS] &&
3027 	    nla_get_u32(data[IFLA_AMT_MAX_TUNNELS]))
3028 		amt->max_tunnels = nla_get_u32(data[IFLA_AMT_MAX_TUNNELS]);
3029 	else
3030 		amt->max_tunnels = AMT_MAX_TUNNELS;
3031 
3032 	spin_lock_init(&amt->lock);
3033 	amt->max_groups = AMT_MAX_GROUP;
3034 	amt->max_sources = AMT_MAX_SOURCE;
3035 	amt->hash_buckets = AMT_HSIZE;
3036 	amt->nr_tunnels = 0;
3037 	get_random_bytes(&amt->hash_seed, sizeof(amt->hash_seed));
3038 	amt->stream_dev = dev_get_by_index(net,
3039 					   nla_get_u32(data[IFLA_AMT_LINK]));
3040 	if (!amt->stream_dev) {
3041 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LINK],
3042 				    "Can't find stream device");
3043 		return -ENODEV;
3044 	}
3045 
3046 	if (amt->stream_dev->type != ARPHRD_ETHER) {
3047 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LINK],
3048 				    "Invalid stream device type");
3049 		goto err;
3050 	}
3051 
3052 	amt->local_ip = nla_get_in_addr(data[IFLA_AMT_LOCAL_IP]);
3053 	if (ipv4_is_loopback(amt->local_ip) ||
3054 	    ipv4_is_zeronet(amt->local_ip) ||
3055 	    ipv4_is_multicast(amt->local_ip)) {
3056 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LOCAL_IP],
3057 				    "Invalid Local address");
3058 		goto err;
3059 	}
3060 
3061 	if (data[IFLA_AMT_RELAY_PORT])
3062 		amt->relay_port = nla_get_be16(data[IFLA_AMT_RELAY_PORT]);
3063 	else
3064 		amt->relay_port = htons(IANA_AMT_UDP_PORT);
3065 
3066 	if (data[IFLA_AMT_GATEWAY_PORT])
3067 		amt->gw_port = nla_get_be16(data[IFLA_AMT_GATEWAY_PORT]);
3068 	else
3069 		amt->gw_port = htons(IANA_AMT_UDP_PORT);
3070 
3071 	if (!amt->relay_port) {
3072 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3073 				    "relay port must not be 0");
3074 		goto err;
3075 	}
3076 	if (amt->mode == AMT_MODE_RELAY) {
3077 		amt->qrv = amt->net->ipv4.sysctl_igmp_qrv;
3078 		amt->qri = 10;
3079 		dev->needed_headroom = amt->stream_dev->needed_headroom +
3080 				       AMT_RELAY_HLEN;
3081 		dev->mtu = amt->stream_dev->mtu - AMT_RELAY_HLEN;
3082 		dev->max_mtu = dev->mtu;
3083 		dev->min_mtu = ETH_MIN_MTU + AMT_RELAY_HLEN;
3084 	} else {
3085 		if (!data[IFLA_AMT_DISCOVERY_IP]) {
3086 			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3087 					    "discovery must be set in gateway mode");
3088 			goto err;
3089 		}
3090 		if (!amt->gw_port) {
3091 			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3092 					    "gateway port must not be 0");
3093 			goto err;
3094 		}
3095 		amt->remote_ip = 0;
3096 		amt->discovery_ip = nla_get_in_addr(data[IFLA_AMT_DISCOVERY_IP]);
3097 		if (ipv4_is_loopback(amt->discovery_ip) ||
3098 		    ipv4_is_zeronet(amt->discovery_ip) ||
3099 		    ipv4_is_multicast(amt->discovery_ip)) {
3100 			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3101 					    "discovery must be unicast");
3102 			goto err;
3103 		}
3104 
3105 		dev->needed_headroom = amt->stream_dev->needed_headroom +
3106 				       AMT_GW_HLEN;
3107 		dev->mtu = amt->stream_dev->mtu - AMT_GW_HLEN;
3108 		dev->max_mtu = dev->mtu;
3109 		dev->min_mtu = ETH_MIN_MTU + AMT_GW_HLEN;
3110 	}
3111 	amt->qi = AMT_INIT_QUERY_INTERVAL;
3112 
3113 	err = register_netdevice(dev);
3114 	if (err < 0) {
3115 		netdev_dbg(dev, "failed to register new netdev %d\n", err);
3116 		goto err;
3117 	}
3118 
3119 	err = netdev_upper_dev_link(amt->stream_dev, dev, extack);
3120 	if (err < 0) {
3121 		unregister_netdevice(dev);
3122 		goto err;
3123 	}
3124 
3125 	INIT_DELAYED_WORK(&amt->discovery_wq, amt_discovery_work);
3126 	INIT_DELAYED_WORK(&amt->req_wq, amt_req_work);
3127 	INIT_DELAYED_WORK(&amt->secret_wq, amt_secret_work);
3128 	INIT_LIST_HEAD(&amt->tunnel_list);
3129 
3130 	return 0;
3131 err:
3132 	dev_put(amt->stream_dev);
3133 	return err;
3134 }
3135 
3136 static void amt_dellink(struct net_device *dev, struct list_head *head)
3137 {
3138 	struct amt_dev *amt = netdev_priv(dev);
3139 
3140 	unregister_netdevice_queue(dev, head);
3141 	netdev_upper_dev_unlink(amt->stream_dev, dev);
3142 	dev_put(amt->stream_dev);
3143 }
3144 
3145 static size_t amt_get_size(const struct net_device *dev)
3146 {
3147 	return nla_total_size(sizeof(__u32)) + /* IFLA_AMT_MODE */
3148 	       nla_total_size(sizeof(__u16)) + /* IFLA_AMT_RELAY_PORT */
3149 	       nla_total_size(sizeof(__u16)) + /* IFLA_AMT_GATEWAY_PORT */
3150 	       nla_total_size(sizeof(__u32)) + /* IFLA_AMT_LINK */
3151 	       nla_total_size(sizeof(__u32)) + /* IFLA_MAX_TUNNELS */
3152 	       nla_total_size(sizeof(struct iphdr)) + /* IFLA_AMT_DISCOVERY_IP */
3153 	       nla_total_size(sizeof(struct iphdr)) + /* IFLA_AMT_REMOTE_IP */
3154 	       nla_total_size(sizeof(struct iphdr)); /* IFLA_AMT_LOCAL_IP */
3155 }
3156 
3157 static int amt_fill_info(struct sk_buff *skb, const struct net_device *dev)
3158 {
3159 	struct amt_dev *amt = netdev_priv(dev);
3160 
3161 	if (nla_put_u32(skb, IFLA_AMT_MODE, amt->mode))
3162 		goto nla_put_failure;
3163 	if (nla_put_be16(skb, IFLA_AMT_RELAY_PORT, amt->relay_port))
3164 		goto nla_put_failure;
3165 	if (nla_put_be16(skb, IFLA_AMT_GATEWAY_PORT, amt->gw_port))
3166 		goto nla_put_failure;
3167 	if (nla_put_u32(skb, IFLA_AMT_LINK, amt->stream_dev->ifindex))
3168 		goto nla_put_failure;
3169 	if (nla_put_in_addr(skb, IFLA_AMT_LOCAL_IP, amt->local_ip))
3170 		goto nla_put_failure;
3171 	if (nla_put_in_addr(skb, IFLA_AMT_DISCOVERY_IP, amt->discovery_ip))
3172 		goto nla_put_failure;
3173 	if (amt->remote_ip)
3174 		if (nla_put_in_addr(skb, IFLA_AMT_REMOTE_IP, amt->remote_ip))
3175 			goto nla_put_failure;
3176 	if (nla_put_u32(skb, IFLA_AMT_MAX_TUNNELS, amt->max_tunnels))
3177 		goto nla_put_failure;
3178 
3179 	return 0;
3180 
3181 nla_put_failure:
3182 	return -EMSGSIZE;
3183 }
3184 
3185 static struct rtnl_link_ops amt_link_ops __read_mostly = {
3186 	.kind		= "amt",
3187 	.maxtype	= IFLA_AMT_MAX,
3188 	.policy		= amt_policy,
3189 	.priv_size	= sizeof(struct amt_dev),
3190 	.setup		= amt_link_setup,
3191 	.validate	= amt_validate,
3192 	.newlink	= amt_newlink,
3193 	.dellink	= amt_dellink,
3194 	.get_size       = amt_get_size,
3195 	.fill_info      = amt_fill_info,
3196 };
3197 
3198 static struct net_device *amt_lookup_upper_dev(struct net_device *dev)
3199 {
3200 	struct net_device *upper_dev;
3201 	struct amt_dev *amt;
3202 
3203 	for_each_netdev(dev_net(dev), upper_dev) {
3204 		if (netif_is_amt(upper_dev)) {
3205 			amt = netdev_priv(upper_dev);
3206 			if (amt->stream_dev == dev)
3207 				return upper_dev;
3208 		}
3209 	}
3210 
3211 	return NULL;
3212 }
3213 
3214 static int amt_device_event(struct notifier_block *unused,
3215 			    unsigned long event, void *ptr)
3216 {
3217 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3218 	struct net_device *upper_dev;
3219 	struct amt_dev *amt;
3220 	LIST_HEAD(list);
3221 	int new_mtu;
3222 
3223 	upper_dev = amt_lookup_upper_dev(dev);
3224 	if (!upper_dev)
3225 		return NOTIFY_DONE;
3226 	amt = netdev_priv(upper_dev);
3227 
3228 	switch (event) {
3229 	case NETDEV_UNREGISTER:
3230 		amt_dellink(amt->dev, &list);
3231 		unregister_netdevice_many(&list);
3232 		break;
3233 	case NETDEV_CHANGEMTU:
3234 		if (amt->mode == AMT_MODE_RELAY)
3235 			new_mtu = dev->mtu - AMT_RELAY_HLEN;
3236 		else
3237 			new_mtu = dev->mtu - AMT_GW_HLEN;
3238 
3239 		dev_set_mtu(amt->dev, new_mtu);
3240 		break;
3241 	}
3242 
3243 	return NOTIFY_DONE;
3244 }
3245 
3246 static struct notifier_block amt_notifier_block __read_mostly = {
3247 	.notifier_call = amt_device_event,
3248 };
3249 
3250 static int __init amt_init(void)
3251 {
3252 	int err;
3253 
3254 	err = register_netdevice_notifier(&amt_notifier_block);
3255 	if (err < 0)
3256 		goto err;
3257 
3258 	err = rtnl_link_register(&amt_link_ops);
3259 	if (err < 0)
3260 		goto unregister_notifier;
3261 
3262 	amt_wq = alloc_workqueue("amt", WQ_UNBOUND, 1);
3263 	if (!amt_wq) {
3264 		err = -ENOMEM;
3265 		goto rtnl_unregister;
3266 	}
3267 
3268 	spin_lock_init(&source_gc_lock);
3269 	spin_lock_bh(&source_gc_lock);
3270 	INIT_DELAYED_WORK(&source_gc_wq, amt_source_gc_work);
3271 	mod_delayed_work(amt_wq, &source_gc_wq,
3272 			 msecs_to_jiffies(AMT_GC_INTERVAL));
3273 	spin_unlock_bh(&source_gc_lock);
3274 
3275 	return 0;
3276 
3277 rtnl_unregister:
3278 	rtnl_link_unregister(&amt_link_ops);
3279 unregister_notifier:
3280 	unregister_netdevice_notifier(&amt_notifier_block);
3281 err:
3282 	pr_err("error loading AMT module loaded\n");
3283 	return err;
3284 }
3285 late_initcall(amt_init);
3286 
3287 static void __exit amt_fini(void)
3288 {
3289 	rtnl_link_unregister(&amt_link_ops);
3290 	unregister_netdevice_notifier(&amt_notifier_block);
3291 	cancel_delayed_work_sync(&source_gc_wq);
3292 	__amt_source_gc_work();
3293 	destroy_workqueue(amt_wq);
3294 }
3295 module_exit(amt_fini);
3296 
3297 MODULE_LICENSE("GPL");
3298 MODULE_AUTHOR("Taehee Yoo <ap420073@gmail.com>");
3299 MODULE_ALIAS_RTNL_LINK("amt");
3300