xref: /linux/drivers/net/amt.c (revision cbac924200b838cfb8d8b1415113d788089dc50b)
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_TEARDOWM",
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 	}
955 	spin_unlock_bh(&amt->lock);
956 
957 	amt_send_request(amt, false);
958 	amt_send_request(amt, true);
959 	amt_update_gw_status(amt, AMT_STATUS_SENT_REQUEST, true);
960 	spin_lock_bh(&amt->lock);
961 out:
962 	exp = min_t(u32, (1 * (1 << amt->req_cnt)), AMT_MAX_REQ_TIMEOUT);
963 	mod_delayed_work(amt_wq, &amt->req_wq, msecs_to_jiffies(exp * 1000));
964 	spin_unlock_bh(&amt->lock);
965 }
966 
967 static bool amt_send_membership_update(struct amt_dev *amt,
968 				       struct sk_buff *skb,
969 				       bool v6)
970 {
971 	struct amt_header_membership_update *amtmu;
972 	struct socket *sock;
973 	struct iphdr *iph;
974 	struct flowi4 fl4;
975 	struct rtable *rt;
976 	int err;
977 
978 	sock = rcu_dereference_bh(amt->sock);
979 	if (!sock)
980 		return true;
981 
982 	err = skb_cow_head(skb, LL_RESERVED_SPACE(amt->dev) + sizeof(*amtmu) +
983 			   sizeof(*iph) + sizeof(struct udphdr));
984 	if (err)
985 		return true;
986 
987 	skb_reset_inner_headers(skb);
988 	memset(&fl4, 0, sizeof(struct flowi4));
989 	fl4.flowi4_oif         = amt->stream_dev->ifindex;
990 	fl4.daddr              = amt->remote_ip;
991 	fl4.saddr              = amt->local_ip;
992 	fl4.flowi4_tos         = AMT_TOS;
993 	fl4.flowi4_proto       = IPPROTO_UDP;
994 	rt = ip_route_output_key(amt->net, &fl4);
995 	if (IS_ERR(rt)) {
996 		netdev_dbg(amt->dev, "no route to %pI4\n", &amt->remote_ip);
997 		return true;
998 	}
999 
1000 	amtmu			= skb_push(skb, sizeof(*amtmu));
1001 	amtmu->version		= 0;
1002 	amtmu->type		= AMT_MSG_MEMBERSHIP_UPDATE;
1003 	amtmu->reserved		= 0;
1004 	amtmu->nonce		= amt->nonce;
1005 	amtmu->response_mac	= amt->mac;
1006 
1007 	if (!v6)
1008 		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1009 	else
1010 		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1011 	udp_tunnel_xmit_skb(rt, sock->sk, skb,
1012 			    fl4.saddr,
1013 			    fl4.daddr,
1014 			    AMT_TOS,
1015 			    ip4_dst_hoplimit(&rt->dst),
1016 			    0,
1017 			    amt->gw_port,
1018 			    amt->relay_port,
1019 			    false,
1020 			    false);
1021 	amt_update_gw_status(amt, AMT_STATUS_SENT_UPDATE, true);
1022 	return false;
1023 }
1024 
1025 static void amt_send_multicast_data(struct amt_dev *amt,
1026 				    const struct sk_buff *oskb,
1027 				    struct amt_tunnel_list *tunnel,
1028 				    bool v6)
1029 {
1030 	struct amt_header_mcast_data *amtmd;
1031 	struct socket *sock;
1032 	struct sk_buff *skb;
1033 	struct iphdr *iph;
1034 	struct flowi4 fl4;
1035 	struct rtable *rt;
1036 
1037 	sock = rcu_dereference_bh(amt->sock);
1038 	if (!sock)
1039 		return;
1040 
1041 	skb = skb_copy_expand(oskb, sizeof(*amtmd) + sizeof(*iph) +
1042 			      sizeof(struct udphdr), 0, GFP_ATOMIC);
1043 	if (!skb)
1044 		return;
1045 
1046 	skb_reset_inner_headers(skb);
1047 	memset(&fl4, 0, sizeof(struct flowi4));
1048 	fl4.flowi4_oif         = amt->stream_dev->ifindex;
1049 	fl4.daddr              = tunnel->ip4;
1050 	fl4.saddr              = amt->local_ip;
1051 	fl4.flowi4_proto       = IPPROTO_UDP;
1052 	rt = ip_route_output_key(amt->net, &fl4);
1053 	if (IS_ERR(rt)) {
1054 		netdev_dbg(amt->dev, "no route to %pI4\n", &tunnel->ip4);
1055 		kfree_skb(skb);
1056 		return;
1057 	}
1058 
1059 	amtmd = skb_push(skb, sizeof(*amtmd));
1060 	amtmd->version = 0;
1061 	amtmd->reserved = 0;
1062 	amtmd->type = AMT_MSG_MULTICAST_DATA;
1063 
1064 	if (!v6)
1065 		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1066 	else
1067 		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1068 	udp_tunnel_xmit_skb(rt, sock->sk, skb,
1069 			    fl4.saddr,
1070 			    fl4.daddr,
1071 			    AMT_TOS,
1072 			    ip4_dst_hoplimit(&rt->dst),
1073 			    0,
1074 			    amt->relay_port,
1075 			    tunnel->source_port,
1076 			    false,
1077 			    false);
1078 }
1079 
1080 static bool amt_send_membership_query(struct amt_dev *amt,
1081 				      struct sk_buff *skb,
1082 				      struct amt_tunnel_list *tunnel,
1083 				      bool v6)
1084 {
1085 	struct amt_header_membership_query *amtmq;
1086 	struct socket *sock;
1087 	struct rtable *rt;
1088 	struct flowi4 fl4;
1089 	int err;
1090 
1091 	sock = rcu_dereference_bh(amt->sock);
1092 	if (!sock)
1093 		return true;
1094 
1095 	err = skb_cow_head(skb, LL_RESERVED_SPACE(amt->dev) + sizeof(*amtmq) +
1096 			   sizeof(struct iphdr) + sizeof(struct udphdr));
1097 	if (err)
1098 		return true;
1099 
1100 	skb_reset_inner_headers(skb);
1101 	memset(&fl4, 0, sizeof(struct flowi4));
1102 	fl4.flowi4_oif         = amt->stream_dev->ifindex;
1103 	fl4.daddr              = tunnel->ip4;
1104 	fl4.saddr              = amt->local_ip;
1105 	fl4.flowi4_tos         = AMT_TOS;
1106 	fl4.flowi4_proto       = IPPROTO_UDP;
1107 	rt = ip_route_output_key(amt->net, &fl4);
1108 	if (IS_ERR(rt)) {
1109 		netdev_dbg(amt->dev, "no route to %pI4\n", &tunnel->ip4);
1110 		return true;
1111 	}
1112 
1113 	amtmq		= skb_push(skb, sizeof(*amtmq));
1114 	amtmq->version	= 0;
1115 	amtmq->type	= AMT_MSG_MEMBERSHIP_QUERY;
1116 	amtmq->reserved = 0;
1117 	amtmq->l	= 0;
1118 	amtmq->g	= 0;
1119 	amtmq->nonce	= tunnel->nonce;
1120 	amtmq->response_mac = tunnel->mac;
1121 
1122 	if (!v6)
1123 		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1124 	else
1125 		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1126 	udp_tunnel_xmit_skb(rt, sock->sk, skb,
1127 			    fl4.saddr,
1128 			    fl4.daddr,
1129 			    AMT_TOS,
1130 			    ip4_dst_hoplimit(&rt->dst),
1131 			    0,
1132 			    amt->relay_port,
1133 			    tunnel->source_port,
1134 			    false,
1135 			    false);
1136 	amt_update_relay_status(tunnel, AMT_STATUS_SENT_QUERY, true);
1137 	return false;
1138 }
1139 
1140 static netdev_tx_t amt_dev_xmit(struct sk_buff *skb, struct net_device *dev)
1141 {
1142 	struct amt_dev *amt = netdev_priv(dev);
1143 	struct amt_tunnel_list *tunnel;
1144 	struct amt_group_node *gnode;
1145 	union amt_addr group = {0,};
1146 #if IS_ENABLED(CONFIG_IPV6)
1147 	struct ipv6hdr *ip6h;
1148 	struct mld_msg *mld;
1149 #endif
1150 	bool report = false;
1151 	struct igmphdr *ih;
1152 	bool query = false;
1153 	struct iphdr *iph;
1154 	bool data = false;
1155 	bool v6 = false;
1156 	u32 hash;
1157 
1158 	iph = ip_hdr(skb);
1159 	if (iph->version == 4) {
1160 		if (!ipv4_is_multicast(iph->daddr))
1161 			goto free;
1162 
1163 		if (!ip_mc_check_igmp(skb)) {
1164 			ih = igmp_hdr(skb);
1165 			switch (ih->type) {
1166 			case IGMPV3_HOST_MEMBERSHIP_REPORT:
1167 			case IGMP_HOST_MEMBERSHIP_REPORT:
1168 				report = true;
1169 				break;
1170 			case IGMP_HOST_MEMBERSHIP_QUERY:
1171 				query = true;
1172 				break;
1173 			default:
1174 				goto free;
1175 			}
1176 		} else {
1177 			data = true;
1178 		}
1179 		v6 = false;
1180 		group.ip4 = iph->daddr;
1181 #if IS_ENABLED(CONFIG_IPV6)
1182 	} else if (iph->version == 6) {
1183 		ip6h = ipv6_hdr(skb);
1184 		if (!ipv6_addr_is_multicast(&ip6h->daddr))
1185 			goto free;
1186 
1187 		if (!ipv6_mc_check_mld(skb)) {
1188 			mld = (struct mld_msg *)skb_transport_header(skb);
1189 			switch (mld->mld_type) {
1190 			case ICMPV6_MGM_REPORT:
1191 			case ICMPV6_MLD2_REPORT:
1192 				report = true;
1193 				break;
1194 			case ICMPV6_MGM_QUERY:
1195 				query = true;
1196 				break;
1197 			default:
1198 				goto free;
1199 			}
1200 		} else {
1201 			data = true;
1202 		}
1203 		v6 = true;
1204 		group.ip6 = ip6h->daddr;
1205 #endif
1206 	} else {
1207 		dev->stats.tx_errors++;
1208 		goto free;
1209 	}
1210 
1211 	if (!pskb_may_pull(skb, sizeof(struct ethhdr)))
1212 		goto free;
1213 
1214 	skb_pull(skb, sizeof(struct ethhdr));
1215 
1216 	if (amt->mode == AMT_MODE_GATEWAY) {
1217 		/* Gateway only passes IGMP/MLD packets */
1218 		if (!report)
1219 			goto free;
1220 		if ((!v6 && !amt->ready4) || (v6 && !amt->ready6))
1221 			goto free;
1222 		if (amt_send_membership_update(amt, skb,  v6))
1223 			goto free;
1224 		goto unlock;
1225 	} else if (amt->mode == AMT_MODE_RELAY) {
1226 		if (query) {
1227 			tunnel = amt_skb_cb(skb)->tunnel;
1228 			if (!tunnel) {
1229 				WARN_ON(1);
1230 				goto free;
1231 			}
1232 
1233 			/* Do not forward unexpected query */
1234 			if (amt_send_membership_query(amt, skb, tunnel, v6))
1235 				goto free;
1236 			goto unlock;
1237 		}
1238 
1239 		if (!data)
1240 			goto free;
1241 		list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list) {
1242 			hash = amt_group_hash(tunnel, &group);
1243 			hlist_for_each_entry_rcu(gnode, &tunnel->groups[hash],
1244 						 node) {
1245 				if (!v6) {
1246 					if (gnode->group_addr.ip4 == iph->daddr)
1247 						goto found;
1248 #if IS_ENABLED(CONFIG_IPV6)
1249 				} else {
1250 					if (ipv6_addr_equal(&gnode->group_addr.ip6,
1251 							    &ip6h->daddr))
1252 						goto found;
1253 #endif
1254 				}
1255 			}
1256 			continue;
1257 found:
1258 			amt_send_multicast_data(amt, skb, tunnel, v6);
1259 		}
1260 	}
1261 
1262 	dev_kfree_skb(skb);
1263 	return NETDEV_TX_OK;
1264 free:
1265 	dev_kfree_skb(skb);
1266 unlock:
1267 	dev->stats.tx_dropped++;
1268 	return NETDEV_TX_OK;
1269 }
1270 
1271 static int amt_parse_type(struct sk_buff *skb)
1272 {
1273 	struct amt_header *amth;
1274 
1275 	if (!pskb_may_pull(skb, sizeof(struct udphdr) +
1276 			   sizeof(struct amt_header)))
1277 		return -1;
1278 
1279 	amth = (struct amt_header *)(udp_hdr(skb) + 1);
1280 
1281 	if (amth->version != 0)
1282 		return -1;
1283 
1284 	if (amth->type >= __AMT_MSG_MAX || !amth->type)
1285 		return -1;
1286 	return amth->type;
1287 }
1288 
1289 static void amt_clear_groups(struct amt_tunnel_list *tunnel)
1290 {
1291 	struct amt_dev *amt = tunnel->amt;
1292 	struct amt_group_node *gnode;
1293 	struct hlist_node *t;
1294 	int i;
1295 
1296 	spin_lock_bh(&tunnel->lock);
1297 	rcu_read_lock();
1298 	for (i = 0; i < amt->hash_buckets; i++)
1299 		hlist_for_each_entry_safe(gnode, t, &tunnel->groups[i], node)
1300 			amt_del_group(amt, gnode);
1301 	rcu_read_unlock();
1302 	spin_unlock_bh(&tunnel->lock);
1303 }
1304 
1305 static void amt_tunnel_expire(struct work_struct *work)
1306 {
1307 	struct amt_tunnel_list *tunnel = container_of(to_delayed_work(work),
1308 						      struct amt_tunnel_list,
1309 						      gc_wq);
1310 	struct amt_dev *amt = tunnel->amt;
1311 
1312 	spin_lock_bh(&amt->lock);
1313 	rcu_read_lock();
1314 	list_del_rcu(&tunnel->list);
1315 	amt->nr_tunnels--;
1316 	amt_clear_groups(tunnel);
1317 	rcu_read_unlock();
1318 	spin_unlock_bh(&amt->lock);
1319 	kfree_rcu(tunnel, rcu);
1320 }
1321 
1322 static void amt_cleanup_srcs(struct amt_dev *amt,
1323 			     struct amt_tunnel_list *tunnel,
1324 			     struct amt_group_node *gnode)
1325 {
1326 	struct amt_source_node *snode;
1327 	struct hlist_node *t;
1328 	int i;
1329 
1330 	/* Delete old sources */
1331 	for (i = 0; i < amt->hash_buckets; i++) {
1332 		hlist_for_each_entry_safe(snode, t, &gnode->sources[i], node) {
1333 			if (snode->flags == AMT_SOURCE_OLD)
1334 				amt_destroy_source(snode);
1335 		}
1336 	}
1337 
1338 	/* switch from new to old */
1339 	for (i = 0; i < amt->hash_buckets; i++)  {
1340 		hlist_for_each_entry_rcu(snode, &gnode->sources[i], node) {
1341 			snode->flags = AMT_SOURCE_OLD;
1342 			if (!gnode->v6)
1343 				netdev_dbg(snode->gnode->amt->dev,
1344 					   "Add source as OLD %pI4 from %pI4\n",
1345 					   &snode->source_addr.ip4,
1346 					   &gnode->group_addr.ip4);
1347 #if IS_ENABLED(CONFIG_IPV6)
1348 			else
1349 				netdev_dbg(snode->gnode->amt->dev,
1350 					   "Add source as OLD %pI6 from %pI6\n",
1351 					   &snode->source_addr.ip6,
1352 					   &gnode->group_addr.ip6);
1353 #endif
1354 		}
1355 	}
1356 }
1357 
1358 static void amt_add_srcs(struct amt_dev *amt, struct amt_tunnel_list *tunnel,
1359 			 struct amt_group_node *gnode, void *grec,
1360 			 bool v6)
1361 {
1362 	struct igmpv3_grec *igmp_grec;
1363 	struct amt_source_node *snode;
1364 #if IS_ENABLED(CONFIG_IPV6)
1365 	struct mld2_grec *mld_grec;
1366 #endif
1367 	union amt_addr src = {0,};
1368 	u16 nsrcs;
1369 	u32 hash;
1370 	int i;
1371 
1372 	if (!v6) {
1373 		igmp_grec = (struct igmpv3_grec *)grec;
1374 		nsrcs = ntohs(igmp_grec->grec_nsrcs);
1375 	} else {
1376 #if IS_ENABLED(CONFIG_IPV6)
1377 		mld_grec = (struct mld2_grec *)grec;
1378 		nsrcs = ntohs(mld_grec->grec_nsrcs);
1379 #else
1380 	return;
1381 #endif
1382 	}
1383 	for (i = 0; i < nsrcs; i++) {
1384 		if (tunnel->nr_sources >= amt->max_sources)
1385 			return;
1386 		if (!v6)
1387 			src.ip4 = igmp_grec->grec_src[i];
1388 #if IS_ENABLED(CONFIG_IPV6)
1389 		else
1390 			memcpy(&src.ip6, &mld_grec->grec_src[i],
1391 			       sizeof(struct in6_addr));
1392 #endif
1393 		if (amt_lookup_src(tunnel, gnode, AMT_FILTER_ALL, &src))
1394 			continue;
1395 
1396 		snode = amt_alloc_snode(gnode, &src);
1397 		if (snode) {
1398 			hash = amt_source_hash(tunnel, &snode->source_addr);
1399 			hlist_add_head_rcu(&snode->node, &gnode->sources[hash]);
1400 			tunnel->nr_sources++;
1401 			gnode->nr_sources++;
1402 
1403 			if (!gnode->v6)
1404 				netdev_dbg(snode->gnode->amt->dev,
1405 					   "Add source as NEW %pI4 from %pI4\n",
1406 					   &snode->source_addr.ip4,
1407 					   &gnode->group_addr.ip4);
1408 #if IS_ENABLED(CONFIG_IPV6)
1409 			else
1410 				netdev_dbg(snode->gnode->amt->dev,
1411 					   "Add source as NEW %pI6 from %pI6\n",
1412 					   &snode->source_addr.ip6,
1413 					   &gnode->group_addr.ip6);
1414 #endif
1415 		}
1416 	}
1417 }
1418 
1419 /* Router State   Report Rec'd New Router State
1420  * ------------   ------------ ----------------
1421  * EXCLUDE (X,Y)  IS_IN (A)    EXCLUDE (X+A,Y-A)
1422  *
1423  * -----------+-----------+-----------+
1424  *            |    OLD    |    NEW    |
1425  * -----------+-----------+-----------+
1426  *    FWD     |     X     |    X+A    |
1427  * -----------+-----------+-----------+
1428  *    D_FWD   |     Y     |    Y-A    |
1429  * -----------+-----------+-----------+
1430  *    NONE    |           |     A     |
1431  * -----------+-----------+-----------+
1432  *
1433  * a) Received sources are NONE/NEW
1434  * b) All NONE will be deleted by amt_cleanup_srcs().
1435  * c) All OLD will be deleted by amt_cleanup_srcs().
1436  * d) After delete, NEW source will be switched to OLD.
1437  */
1438 static void amt_lookup_act_srcs(struct amt_tunnel_list *tunnel,
1439 				struct amt_group_node *gnode,
1440 				void *grec,
1441 				enum amt_ops ops,
1442 				enum amt_filter filter,
1443 				enum amt_act act,
1444 				bool v6)
1445 {
1446 	struct amt_dev *amt = tunnel->amt;
1447 	struct amt_source_node *snode;
1448 	struct igmpv3_grec *igmp_grec;
1449 #if IS_ENABLED(CONFIG_IPV6)
1450 	struct mld2_grec *mld_grec;
1451 #endif
1452 	union amt_addr src = {0,};
1453 	struct hlist_node *t;
1454 	u16 nsrcs;
1455 	int i, j;
1456 
1457 	if (!v6) {
1458 		igmp_grec = (struct igmpv3_grec *)grec;
1459 		nsrcs = ntohs(igmp_grec->grec_nsrcs);
1460 	} else {
1461 #if IS_ENABLED(CONFIG_IPV6)
1462 		mld_grec = (struct mld2_grec *)grec;
1463 		nsrcs = ntohs(mld_grec->grec_nsrcs);
1464 #else
1465 	return;
1466 #endif
1467 	}
1468 
1469 	memset(&src, 0, sizeof(union amt_addr));
1470 	switch (ops) {
1471 	case AMT_OPS_INT:
1472 		/* A*B */
1473 		for (i = 0; i < nsrcs; i++) {
1474 			if (!v6)
1475 				src.ip4 = igmp_grec->grec_src[i];
1476 #if IS_ENABLED(CONFIG_IPV6)
1477 			else
1478 				memcpy(&src.ip6, &mld_grec->grec_src[i],
1479 				       sizeof(struct in6_addr));
1480 #endif
1481 			snode = amt_lookup_src(tunnel, gnode, filter, &src);
1482 			if (!snode)
1483 				continue;
1484 			amt_act_src(tunnel, gnode, snode, act);
1485 		}
1486 		break;
1487 	case AMT_OPS_UNI:
1488 		/* A+B */
1489 		for (i = 0; i < amt->hash_buckets; i++) {
1490 			hlist_for_each_entry_safe(snode, t, &gnode->sources[i],
1491 						  node) {
1492 				if (amt_status_filter(snode, filter))
1493 					amt_act_src(tunnel, gnode, snode, act);
1494 			}
1495 		}
1496 		for (i = 0; i < nsrcs; i++) {
1497 			if (!v6)
1498 				src.ip4 = igmp_grec->grec_src[i];
1499 #if IS_ENABLED(CONFIG_IPV6)
1500 			else
1501 				memcpy(&src.ip6, &mld_grec->grec_src[i],
1502 				       sizeof(struct in6_addr));
1503 #endif
1504 			snode = amt_lookup_src(tunnel, gnode, filter, &src);
1505 			if (!snode)
1506 				continue;
1507 			amt_act_src(tunnel, gnode, snode, act);
1508 		}
1509 		break;
1510 	case AMT_OPS_SUB:
1511 		/* A-B */
1512 		for (i = 0; i < amt->hash_buckets; i++) {
1513 			hlist_for_each_entry_safe(snode, t, &gnode->sources[i],
1514 						  node) {
1515 				if (!amt_status_filter(snode, filter))
1516 					continue;
1517 				for (j = 0; j < nsrcs; j++) {
1518 					if (!v6)
1519 						src.ip4 = igmp_grec->grec_src[j];
1520 #if IS_ENABLED(CONFIG_IPV6)
1521 					else
1522 						memcpy(&src.ip6,
1523 						       &mld_grec->grec_src[j],
1524 						       sizeof(struct in6_addr));
1525 #endif
1526 					if (amt_addr_equal(&snode->source_addr,
1527 							   &src))
1528 						goto out_sub;
1529 				}
1530 				amt_act_src(tunnel, gnode, snode, act);
1531 				continue;
1532 out_sub:;
1533 			}
1534 		}
1535 		break;
1536 	case AMT_OPS_SUB_REV:
1537 		/* B-A */
1538 		for (i = 0; i < nsrcs; i++) {
1539 			if (!v6)
1540 				src.ip4 = igmp_grec->grec_src[i];
1541 #if IS_ENABLED(CONFIG_IPV6)
1542 			else
1543 				memcpy(&src.ip6, &mld_grec->grec_src[i],
1544 				       sizeof(struct in6_addr));
1545 #endif
1546 			snode = amt_lookup_src(tunnel, gnode, AMT_FILTER_ALL,
1547 					       &src);
1548 			if (!snode) {
1549 				snode = amt_lookup_src(tunnel, gnode,
1550 						       filter, &src);
1551 				if (snode)
1552 					amt_act_src(tunnel, gnode, snode, act);
1553 			}
1554 		}
1555 		break;
1556 	default:
1557 		netdev_dbg(amt->dev, "Invalid type\n");
1558 		return;
1559 	}
1560 }
1561 
1562 static void amt_mcast_is_in_handler(struct amt_dev *amt,
1563 				    struct amt_tunnel_list *tunnel,
1564 				    struct amt_group_node *gnode,
1565 				    void *grec, void *zero_grec, bool v6)
1566 {
1567 	if (gnode->filter_mode == MCAST_INCLUDE) {
1568 /* Router State   Report Rec'd New Router State        Actions
1569  * ------------   ------------ ----------------        -------
1570  * INCLUDE (A)    IS_IN (B)    INCLUDE (A+B)           (B)=GMI
1571  */
1572 		/* Update IS_IN (B) as FWD/NEW */
1573 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1574 				    AMT_FILTER_NONE_NEW,
1575 				    AMT_ACT_STATUS_FWD_NEW,
1576 				    v6);
1577 		/* Update INCLUDE (A) as NEW */
1578 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1579 				    AMT_FILTER_FWD,
1580 				    AMT_ACT_STATUS_FWD_NEW,
1581 				    v6);
1582 		/* (B)=GMI */
1583 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1584 				    AMT_FILTER_FWD_NEW,
1585 				    AMT_ACT_GMI,
1586 				    v6);
1587 	} else {
1588 /* State        Actions
1589  * ------------   ------------ ----------------        -------
1590  * EXCLUDE (X,Y)  IS_IN (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1591  */
1592 		/* Update (A) in (X, Y) as NONE/NEW */
1593 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1594 				    AMT_FILTER_BOTH,
1595 				    AMT_ACT_STATUS_NONE_NEW,
1596 				    v6);
1597 		/* Update FWD/OLD as FWD/NEW */
1598 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1599 				    AMT_FILTER_FWD,
1600 				    AMT_ACT_STATUS_FWD_NEW,
1601 				    v6);
1602 		/* Update IS_IN (A) as FWD/NEW */
1603 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1604 				    AMT_FILTER_NONE_NEW,
1605 				    AMT_ACT_STATUS_FWD_NEW,
1606 				    v6);
1607 		/* Update EXCLUDE (, Y-A) as D_FWD_NEW */
1608 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB,
1609 				    AMT_FILTER_D_FWD,
1610 				    AMT_ACT_STATUS_D_FWD_NEW,
1611 				    v6);
1612 	}
1613 }
1614 
1615 static void amt_mcast_is_ex_handler(struct amt_dev *amt,
1616 				    struct amt_tunnel_list *tunnel,
1617 				    struct amt_group_node *gnode,
1618 				    void *grec, void *zero_grec, bool v6)
1619 {
1620 	if (gnode->filter_mode == MCAST_INCLUDE) {
1621 /* Router State   Report Rec'd  New Router State         Actions
1622  * ------------   ------------  ----------------         -------
1623  * INCLUDE (A)    IS_EX (B)     EXCLUDE (A*B,B-A)        (B-A)=0
1624  *                                                       Delete (A-B)
1625  *                                                       Group Timer=GMI
1626  */
1627 		/* EXCLUDE(A*B, ) */
1628 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1629 				    AMT_FILTER_FWD,
1630 				    AMT_ACT_STATUS_FWD_NEW,
1631 				    v6);
1632 		/* EXCLUDE(, B-A) */
1633 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1634 				    AMT_FILTER_FWD,
1635 				    AMT_ACT_STATUS_D_FWD_NEW,
1636 				    v6);
1637 		/* (B-A)=0 */
1638 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1639 				    AMT_FILTER_D_FWD_NEW,
1640 				    AMT_ACT_GMI_ZERO,
1641 				    v6);
1642 		/* Group Timer=GMI */
1643 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1644 				      msecs_to_jiffies(amt_gmi(amt))))
1645 			dev_hold(amt->dev);
1646 		gnode->filter_mode = MCAST_EXCLUDE;
1647 		/* Delete (A-B) will be worked by amt_cleanup_srcs(). */
1648 	} else {
1649 /* Router State   Report Rec'd  New Router State	Actions
1650  * ------------   ------------  ----------------	-------
1651  * EXCLUDE (X,Y)  IS_EX (A)     EXCLUDE (A-Y,Y*A)	(A-X-Y)=GMI
1652  *							Delete (X-A)
1653  *							Delete (Y-A)
1654  *							Group Timer=GMI
1655  */
1656 		/* EXCLUDE (A-Y, ) */
1657 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1658 				    AMT_FILTER_D_FWD,
1659 				    AMT_ACT_STATUS_FWD_NEW,
1660 				    v6);
1661 		/* EXCLUDE (, Y*A ) */
1662 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1663 				    AMT_FILTER_D_FWD,
1664 				    AMT_ACT_STATUS_D_FWD_NEW,
1665 				    v6);
1666 		/* (A-X-Y)=GMI */
1667 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1668 				    AMT_FILTER_BOTH_NEW,
1669 				    AMT_ACT_GMI,
1670 				    v6);
1671 		/* Group Timer=GMI */
1672 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1673 				      msecs_to_jiffies(amt_gmi(amt))))
1674 			dev_hold(amt->dev);
1675 		/* Delete (X-A), (Y-A) will be worked by amt_cleanup_srcs(). */
1676 	}
1677 }
1678 
1679 static void amt_mcast_to_in_handler(struct amt_dev *amt,
1680 				    struct amt_tunnel_list *tunnel,
1681 				    struct amt_group_node *gnode,
1682 				    void *grec, void *zero_grec, bool v6)
1683 {
1684 	if (gnode->filter_mode == MCAST_INCLUDE) {
1685 /* Router State   Report Rec'd New Router State        Actions
1686  * ------------   ------------ ----------------        -------
1687  * INCLUDE (A)    TO_IN (B)    INCLUDE (A+B)           (B)=GMI
1688  *						       Send Q(G,A-B)
1689  */
1690 		/* Update TO_IN (B) sources as FWD/NEW */
1691 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1692 				    AMT_FILTER_NONE_NEW,
1693 				    AMT_ACT_STATUS_FWD_NEW,
1694 				    v6);
1695 		/* Update INCLUDE (A) sources as NEW */
1696 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1697 				    AMT_FILTER_FWD,
1698 				    AMT_ACT_STATUS_FWD_NEW,
1699 				    v6);
1700 		/* (B)=GMI */
1701 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1702 				    AMT_FILTER_FWD_NEW,
1703 				    AMT_ACT_GMI,
1704 				    v6);
1705 	} else {
1706 /* Router State   Report Rec'd New Router State        Actions
1707  * ------------   ------------ ----------------        -------
1708  * EXCLUDE (X,Y)  TO_IN (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1709  *						       Send Q(G,X-A)
1710  *						       Send Q(G)
1711  */
1712 		/* Update TO_IN (A) sources as FWD/NEW */
1713 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1714 				    AMT_FILTER_NONE_NEW,
1715 				    AMT_ACT_STATUS_FWD_NEW,
1716 				    v6);
1717 		/* Update EXCLUDE(X,) sources as FWD/NEW */
1718 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1719 				    AMT_FILTER_FWD,
1720 				    AMT_ACT_STATUS_FWD_NEW,
1721 				    v6);
1722 		/* EXCLUDE (, Y-A)
1723 		 * (A) are already switched to FWD_NEW.
1724 		 * So, D_FWD/OLD -> D_FWD/NEW is okay.
1725 		 */
1726 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1727 				    AMT_FILTER_D_FWD,
1728 				    AMT_ACT_STATUS_D_FWD_NEW,
1729 				    v6);
1730 		/* (A)=GMI
1731 		 * Only FWD_NEW will have (A) sources.
1732 		 */
1733 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1734 				    AMT_FILTER_FWD_NEW,
1735 				    AMT_ACT_GMI,
1736 				    v6);
1737 	}
1738 }
1739 
1740 static void amt_mcast_to_ex_handler(struct amt_dev *amt,
1741 				    struct amt_tunnel_list *tunnel,
1742 				    struct amt_group_node *gnode,
1743 				    void *grec, void *zero_grec, bool v6)
1744 {
1745 	if (gnode->filter_mode == MCAST_INCLUDE) {
1746 /* Router State   Report Rec'd New Router State        Actions
1747  * ------------   ------------ ----------------        -------
1748  * INCLUDE (A)    TO_EX (B)    EXCLUDE (A*B,B-A)       (B-A)=0
1749  *						       Delete (A-B)
1750  *						       Send Q(G,A*B)
1751  *						       Group Timer=GMI
1752  */
1753 		/* EXCLUDE (A*B, ) */
1754 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1755 				    AMT_FILTER_FWD,
1756 				    AMT_ACT_STATUS_FWD_NEW,
1757 				    v6);
1758 		/* EXCLUDE (, B-A) */
1759 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1760 				    AMT_FILTER_FWD,
1761 				    AMT_ACT_STATUS_D_FWD_NEW,
1762 				    v6);
1763 		/* (B-A)=0 */
1764 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1765 				    AMT_FILTER_D_FWD_NEW,
1766 				    AMT_ACT_GMI_ZERO,
1767 				    v6);
1768 		/* Group Timer=GMI */
1769 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1770 				      msecs_to_jiffies(amt_gmi(amt))))
1771 			dev_hold(amt->dev);
1772 		gnode->filter_mode = MCAST_EXCLUDE;
1773 		/* Delete (A-B) will be worked by amt_cleanup_srcs(). */
1774 	} else {
1775 /* Router State   Report Rec'd New Router State        Actions
1776  * ------------   ------------ ----------------        -------
1777  * EXCLUDE (X,Y)  TO_EX (A)    EXCLUDE (A-Y,Y*A)       (A-X-Y)=Group Timer
1778  *						       Delete (X-A)
1779  *						       Delete (Y-A)
1780  *						       Send Q(G,A-Y)
1781  *						       Group Timer=GMI
1782  */
1783 		/* Update (A-X-Y) as NONE/OLD */
1784 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1785 				    AMT_FILTER_BOTH,
1786 				    AMT_ACT_GT,
1787 				    v6);
1788 		/* EXCLUDE (A-Y, ) */
1789 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1790 				    AMT_FILTER_D_FWD,
1791 				    AMT_ACT_STATUS_FWD_NEW,
1792 				    v6);
1793 		/* EXCLUDE (, Y*A) */
1794 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1795 				    AMT_FILTER_D_FWD,
1796 				    AMT_ACT_STATUS_D_FWD_NEW,
1797 				    v6);
1798 		/* Group Timer=GMI */
1799 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1800 				      msecs_to_jiffies(amt_gmi(amt))))
1801 			dev_hold(amt->dev);
1802 		/* Delete (X-A), (Y-A) will be worked by amt_cleanup_srcs(). */
1803 	}
1804 }
1805 
1806 static void amt_mcast_allow_handler(struct amt_dev *amt,
1807 				    struct amt_tunnel_list *tunnel,
1808 				    struct amt_group_node *gnode,
1809 				    void *grec, void *zero_grec, bool v6)
1810 {
1811 	if (gnode->filter_mode == MCAST_INCLUDE) {
1812 /* Router State   Report Rec'd New Router State        Actions
1813  * ------------   ------------ ----------------        -------
1814  * INCLUDE (A)    ALLOW (B)    INCLUDE (A+B)	       (B)=GMI
1815  */
1816 		/* INCLUDE (A+B) */
1817 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1818 				    AMT_FILTER_FWD,
1819 				    AMT_ACT_STATUS_FWD_NEW,
1820 				    v6);
1821 		/* (B)=GMI */
1822 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1823 				    AMT_FILTER_FWD_NEW,
1824 				    AMT_ACT_GMI,
1825 				    v6);
1826 	} else {
1827 /* Router State   Report Rec'd New Router State        Actions
1828  * ------------   ------------ ----------------        -------
1829  * EXCLUDE (X,Y)  ALLOW (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1830  */
1831 		/* EXCLUDE (X+A, ) */
1832 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1833 				    AMT_FILTER_FWD,
1834 				    AMT_ACT_STATUS_FWD_NEW,
1835 				    v6);
1836 		/* EXCLUDE (, Y-A) */
1837 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB,
1838 				    AMT_FILTER_D_FWD,
1839 				    AMT_ACT_STATUS_D_FWD_NEW,
1840 				    v6);
1841 		/* (A)=GMI
1842 		 * All (A) source are now FWD/NEW status.
1843 		 */
1844 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1845 				    AMT_FILTER_FWD_NEW,
1846 				    AMT_ACT_GMI,
1847 				    v6);
1848 	}
1849 }
1850 
1851 static void amt_mcast_block_handler(struct amt_dev *amt,
1852 				    struct amt_tunnel_list *tunnel,
1853 				    struct amt_group_node *gnode,
1854 				    void *grec, void *zero_grec, bool v6)
1855 {
1856 	if (gnode->filter_mode == MCAST_INCLUDE) {
1857 /* Router State   Report Rec'd New Router State        Actions
1858  * ------------   ------------ ----------------        -------
1859  * INCLUDE (A)    BLOCK (B)    INCLUDE (A)             Send Q(G,A*B)
1860  */
1861 		/* INCLUDE (A) */
1862 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1863 				    AMT_FILTER_FWD,
1864 				    AMT_ACT_STATUS_FWD_NEW,
1865 				    v6);
1866 	} else {
1867 /* Router State   Report Rec'd New Router State        Actions
1868  * ------------   ------------ ----------------        -------
1869  * EXCLUDE (X,Y)  BLOCK (A)    EXCLUDE (X+(A-Y),Y)     (A-X-Y)=Group Timer
1870  *						       Send Q(G,A-Y)
1871  */
1872 		/* (A-X-Y)=Group Timer */
1873 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1874 				    AMT_FILTER_BOTH,
1875 				    AMT_ACT_GT,
1876 				    v6);
1877 		/* EXCLUDE (X, ) */
1878 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1879 				    AMT_FILTER_FWD,
1880 				    AMT_ACT_STATUS_FWD_NEW,
1881 				    v6);
1882 		/* EXCLUDE (X+(A-Y) */
1883 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1884 				    AMT_FILTER_D_FWD,
1885 				    AMT_ACT_STATUS_FWD_NEW,
1886 				    v6);
1887 		/* EXCLUDE (, Y) */
1888 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1889 				    AMT_FILTER_D_FWD,
1890 				    AMT_ACT_STATUS_D_FWD_NEW,
1891 				    v6);
1892 	}
1893 }
1894 
1895 /* RFC 3376
1896  * 7.3.2. In the Presence of Older Version Group Members
1897  *
1898  * When Group Compatibility Mode is IGMPv2, a router internally
1899  * translates the following IGMPv2 messages for that group to their
1900  * IGMPv3 equivalents:
1901  *
1902  * IGMPv2 Message                IGMPv3 Equivalent
1903  * --------------                -----------------
1904  * Report                        IS_EX( {} )
1905  * Leave                         TO_IN( {} )
1906  */
1907 static void amt_igmpv2_report_handler(struct amt_dev *amt, struct sk_buff *skb,
1908 				      struct amt_tunnel_list *tunnel)
1909 {
1910 	struct igmphdr *ih = igmp_hdr(skb);
1911 	struct iphdr *iph = ip_hdr(skb);
1912 	struct amt_group_node *gnode;
1913 	union amt_addr group, host;
1914 
1915 	memset(&group, 0, sizeof(union amt_addr));
1916 	group.ip4 = ih->group;
1917 	memset(&host, 0, sizeof(union amt_addr));
1918 	host.ip4 = iph->saddr;
1919 
1920 	gnode = amt_lookup_group(tunnel, &group, &host, false);
1921 	if (!gnode) {
1922 		gnode = amt_add_group(amt, tunnel, &group, &host, false);
1923 		if (!IS_ERR(gnode)) {
1924 			gnode->filter_mode = MCAST_EXCLUDE;
1925 			if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1926 					      msecs_to_jiffies(amt_gmi(amt))))
1927 				dev_hold(amt->dev);
1928 		}
1929 	}
1930 }
1931 
1932 /* RFC 3376
1933  * 7.3.2. In the Presence of Older Version Group Members
1934  *
1935  * When Group Compatibility Mode is IGMPv2, a router internally
1936  * translates the following IGMPv2 messages for that group to their
1937  * IGMPv3 equivalents:
1938  *
1939  * IGMPv2 Message                IGMPv3 Equivalent
1940  * --------------                -----------------
1941  * Report                        IS_EX( {} )
1942  * Leave                         TO_IN( {} )
1943  */
1944 static void amt_igmpv2_leave_handler(struct amt_dev *amt, struct sk_buff *skb,
1945 				     struct amt_tunnel_list *tunnel)
1946 {
1947 	struct igmphdr *ih = igmp_hdr(skb);
1948 	struct iphdr *iph = ip_hdr(skb);
1949 	struct amt_group_node *gnode;
1950 	union amt_addr group, host;
1951 
1952 	memset(&group, 0, sizeof(union amt_addr));
1953 	group.ip4 = ih->group;
1954 	memset(&host, 0, sizeof(union amt_addr));
1955 	host.ip4 = iph->saddr;
1956 
1957 	gnode = amt_lookup_group(tunnel, &group, &host, false);
1958 	if (gnode)
1959 		amt_del_group(amt, gnode);
1960 }
1961 
1962 static void amt_igmpv3_report_handler(struct amt_dev *amt, struct sk_buff *skb,
1963 				      struct amt_tunnel_list *tunnel)
1964 {
1965 	struct igmpv3_report *ihrv3 = igmpv3_report_hdr(skb);
1966 	int len = skb_transport_offset(skb) + sizeof(*ihrv3);
1967 	void *zero_grec = (void *)&igmpv3_zero_grec;
1968 	struct iphdr *iph = ip_hdr(skb);
1969 	struct amt_group_node *gnode;
1970 	union amt_addr group, host;
1971 	struct igmpv3_grec *grec;
1972 	u16 nsrcs;
1973 	int i;
1974 
1975 	for (i = 0; i < ntohs(ihrv3->ngrec); i++) {
1976 		len += sizeof(*grec);
1977 		if (!ip_mc_may_pull(skb, len))
1978 			break;
1979 
1980 		grec = (void *)(skb->data + len - sizeof(*grec));
1981 		nsrcs = ntohs(grec->grec_nsrcs);
1982 
1983 		len += nsrcs * sizeof(__be32);
1984 		if (!ip_mc_may_pull(skb, len))
1985 			break;
1986 
1987 		memset(&group, 0, sizeof(union amt_addr));
1988 		group.ip4 = grec->grec_mca;
1989 		memset(&host, 0, sizeof(union amt_addr));
1990 		host.ip4 = iph->saddr;
1991 		gnode = amt_lookup_group(tunnel, &group, &host, false);
1992 		if (!gnode) {
1993 			gnode = amt_add_group(amt, tunnel, &group, &host,
1994 					      false);
1995 			if (IS_ERR(gnode))
1996 				continue;
1997 		}
1998 
1999 		amt_add_srcs(amt, tunnel, gnode, grec, false);
2000 		switch (grec->grec_type) {
2001 		case IGMPV3_MODE_IS_INCLUDE:
2002 			amt_mcast_is_in_handler(amt, tunnel, gnode, grec,
2003 						zero_grec, false);
2004 			break;
2005 		case IGMPV3_MODE_IS_EXCLUDE:
2006 			amt_mcast_is_ex_handler(amt, tunnel, gnode, grec,
2007 						zero_grec, false);
2008 			break;
2009 		case IGMPV3_CHANGE_TO_INCLUDE:
2010 			amt_mcast_to_in_handler(amt, tunnel, gnode, grec,
2011 						zero_grec, false);
2012 			break;
2013 		case IGMPV3_CHANGE_TO_EXCLUDE:
2014 			amt_mcast_to_ex_handler(amt, tunnel, gnode, grec,
2015 						zero_grec, false);
2016 			break;
2017 		case IGMPV3_ALLOW_NEW_SOURCES:
2018 			amt_mcast_allow_handler(amt, tunnel, gnode, grec,
2019 						zero_grec, false);
2020 			break;
2021 		case IGMPV3_BLOCK_OLD_SOURCES:
2022 			amt_mcast_block_handler(amt, tunnel, gnode, grec,
2023 						zero_grec, false);
2024 			break;
2025 		default:
2026 			break;
2027 		}
2028 		amt_cleanup_srcs(amt, tunnel, gnode);
2029 	}
2030 }
2031 
2032 /* caller held tunnel->lock */
2033 static void amt_igmp_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2034 				    struct amt_tunnel_list *tunnel)
2035 {
2036 	struct igmphdr *ih = igmp_hdr(skb);
2037 
2038 	switch (ih->type) {
2039 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
2040 		amt_igmpv3_report_handler(amt, skb, tunnel);
2041 		break;
2042 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
2043 		amt_igmpv2_report_handler(amt, skb, tunnel);
2044 		break;
2045 	case IGMP_HOST_LEAVE_MESSAGE:
2046 		amt_igmpv2_leave_handler(amt, skb, tunnel);
2047 		break;
2048 	default:
2049 		break;
2050 	}
2051 }
2052 
2053 #if IS_ENABLED(CONFIG_IPV6)
2054 /* RFC 3810
2055  * 8.3.2. In the Presence of MLDv1 Multicast Address Listeners
2056  *
2057  * When Multicast Address Compatibility Mode is MLDv2, a router acts
2058  * using the MLDv2 protocol for that multicast address.  When Multicast
2059  * Address Compatibility Mode is MLDv1, a router internally translates
2060  * the following MLDv1 messages for that multicast address to their
2061  * MLDv2 equivalents:
2062  *
2063  * MLDv1 Message                 MLDv2 Equivalent
2064  * --------------                -----------------
2065  * Report                        IS_EX( {} )
2066  * Done                          TO_IN( {} )
2067  */
2068 static void amt_mldv1_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2069 				     struct amt_tunnel_list *tunnel)
2070 {
2071 	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2072 	struct ipv6hdr *ip6h = ipv6_hdr(skb);
2073 	struct amt_group_node *gnode;
2074 	union amt_addr group, host;
2075 
2076 	memcpy(&group.ip6, &mld->mld_mca, sizeof(struct in6_addr));
2077 	memcpy(&host.ip6, &ip6h->saddr, sizeof(struct in6_addr));
2078 
2079 	gnode = amt_lookup_group(tunnel, &group, &host, true);
2080 	if (!gnode) {
2081 		gnode = amt_add_group(amt, tunnel, &group, &host, true);
2082 		if (!IS_ERR(gnode)) {
2083 			gnode->filter_mode = MCAST_EXCLUDE;
2084 			if (!mod_delayed_work(amt_wq, &gnode->group_timer,
2085 					      msecs_to_jiffies(amt_gmi(amt))))
2086 				dev_hold(amt->dev);
2087 		}
2088 	}
2089 }
2090 
2091 /* RFC 3810
2092  * 8.3.2. In the Presence of MLDv1 Multicast Address Listeners
2093  *
2094  * When Multicast Address Compatibility Mode is MLDv2, a router acts
2095  * using the MLDv2 protocol for that multicast address.  When Multicast
2096  * Address Compatibility Mode is MLDv1, a router internally translates
2097  * the following MLDv1 messages for that multicast address to their
2098  * MLDv2 equivalents:
2099  *
2100  * MLDv1 Message                 MLDv2 Equivalent
2101  * --------------                -----------------
2102  * Report                        IS_EX( {} )
2103  * Done                          TO_IN( {} )
2104  */
2105 static void amt_mldv1_leave_handler(struct amt_dev *amt, struct sk_buff *skb,
2106 				    struct amt_tunnel_list *tunnel)
2107 {
2108 	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2109 	struct iphdr *iph = ip_hdr(skb);
2110 	struct amt_group_node *gnode;
2111 	union amt_addr group, host;
2112 
2113 	memcpy(&group.ip6, &mld->mld_mca, sizeof(struct in6_addr));
2114 	memset(&host, 0, sizeof(union amt_addr));
2115 	host.ip4 = iph->saddr;
2116 
2117 	gnode = amt_lookup_group(tunnel, &group, &host, true);
2118 	if (gnode) {
2119 		amt_del_group(amt, gnode);
2120 		return;
2121 	}
2122 }
2123 
2124 static void amt_mldv2_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2125 				     struct amt_tunnel_list *tunnel)
2126 {
2127 	struct mld2_report *mld2r = (struct mld2_report *)icmp6_hdr(skb);
2128 	int len = skb_transport_offset(skb) + sizeof(*mld2r);
2129 	void *zero_grec = (void *)&mldv2_zero_grec;
2130 	struct ipv6hdr *ip6h = ipv6_hdr(skb);
2131 	struct amt_group_node *gnode;
2132 	union amt_addr group, host;
2133 	struct mld2_grec *grec;
2134 	u16 nsrcs;
2135 	int i;
2136 
2137 	for (i = 0; i < ntohs(mld2r->mld2r_ngrec); i++) {
2138 		len += sizeof(*grec);
2139 		if (!ipv6_mc_may_pull(skb, len))
2140 			break;
2141 
2142 		grec = (void *)(skb->data + len - sizeof(*grec));
2143 		nsrcs = ntohs(grec->grec_nsrcs);
2144 
2145 		len += nsrcs * sizeof(struct in6_addr);
2146 		if (!ipv6_mc_may_pull(skb, len))
2147 			break;
2148 
2149 		memset(&group, 0, sizeof(union amt_addr));
2150 		group.ip6 = grec->grec_mca;
2151 		memset(&host, 0, sizeof(union amt_addr));
2152 		host.ip6 = ip6h->saddr;
2153 		gnode = amt_lookup_group(tunnel, &group, &host, true);
2154 		if (!gnode) {
2155 			gnode = amt_add_group(amt, tunnel, &group, &host,
2156 					      ETH_P_IPV6);
2157 			if (IS_ERR(gnode))
2158 				continue;
2159 		}
2160 
2161 		amt_add_srcs(amt, tunnel, gnode, grec, true);
2162 		switch (grec->grec_type) {
2163 		case MLD2_MODE_IS_INCLUDE:
2164 			amt_mcast_is_in_handler(amt, tunnel, gnode, grec,
2165 						zero_grec, true);
2166 			break;
2167 		case MLD2_MODE_IS_EXCLUDE:
2168 			amt_mcast_is_ex_handler(amt, tunnel, gnode, grec,
2169 						zero_grec, true);
2170 			break;
2171 		case MLD2_CHANGE_TO_INCLUDE:
2172 			amt_mcast_to_in_handler(amt, tunnel, gnode, grec,
2173 						zero_grec, true);
2174 			break;
2175 		case MLD2_CHANGE_TO_EXCLUDE:
2176 			amt_mcast_to_ex_handler(amt, tunnel, gnode, grec,
2177 						zero_grec, true);
2178 			break;
2179 		case MLD2_ALLOW_NEW_SOURCES:
2180 			amt_mcast_allow_handler(amt, tunnel, gnode, grec,
2181 						zero_grec, true);
2182 			break;
2183 		case MLD2_BLOCK_OLD_SOURCES:
2184 			amt_mcast_block_handler(amt, tunnel, gnode, grec,
2185 						zero_grec, true);
2186 			break;
2187 		default:
2188 			break;
2189 		}
2190 		amt_cleanup_srcs(amt, tunnel, gnode);
2191 	}
2192 }
2193 
2194 /* caller held tunnel->lock */
2195 static void amt_mld_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2196 				   struct amt_tunnel_list *tunnel)
2197 {
2198 	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2199 
2200 	switch (mld->mld_type) {
2201 	case ICMPV6_MGM_REPORT:
2202 		amt_mldv1_report_handler(amt, skb, tunnel);
2203 		break;
2204 	case ICMPV6_MLD2_REPORT:
2205 		amt_mldv2_report_handler(amt, skb, tunnel);
2206 		break;
2207 	case ICMPV6_MGM_REDUCTION:
2208 		amt_mldv1_leave_handler(amt, skb, tunnel);
2209 		break;
2210 	default:
2211 		break;
2212 	}
2213 }
2214 #endif
2215 
2216 static bool amt_advertisement_handler(struct amt_dev *amt, struct sk_buff *skb)
2217 {
2218 	struct amt_header_advertisement *amta;
2219 	int hdr_size;
2220 
2221 	hdr_size = sizeof(*amta) - sizeof(struct amt_header);
2222 
2223 	if (!pskb_may_pull(skb, hdr_size))
2224 		return true;
2225 
2226 	amta = (struct amt_header_advertisement *)(udp_hdr(skb) + 1);
2227 	if (!amta->ip4)
2228 		return true;
2229 
2230 	if (amta->reserved || amta->version)
2231 		return true;
2232 
2233 	if (ipv4_is_loopback(amta->ip4) || ipv4_is_multicast(amta->ip4) ||
2234 	    ipv4_is_zeronet(amta->ip4))
2235 		return true;
2236 
2237 	amt->remote_ip = amta->ip4;
2238 	netdev_dbg(amt->dev, "advertised remote ip = %pI4\n", &amt->remote_ip);
2239 	mod_delayed_work(amt_wq, &amt->req_wq, 0);
2240 
2241 	amt_update_gw_status(amt, AMT_STATUS_RECEIVED_ADVERTISEMENT, true);
2242 	return false;
2243 }
2244 
2245 static bool amt_multicast_data_handler(struct amt_dev *amt, struct sk_buff *skb)
2246 {
2247 	struct amt_header_mcast_data *amtmd;
2248 	int hdr_size, len, err;
2249 	struct ethhdr *eth;
2250 	struct iphdr *iph;
2251 
2252 	amtmd = (struct amt_header_mcast_data *)(udp_hdr(skb) + 1);
2253 	if (amtmd->reserved || amtmd->version)
2254 		return true;
2255 
2256 	hdr_size = sizeof(*amtmd) + sizeof(struct udphdr);
2257 	if (iptunnel_pull_header(skb, hdr_size, htons(ETH_P_IP), false))
2258 		return true;
2259 	skb_reset_network_header(skb);
2260 	skb_push(skb, sizeof(*eth));
2261 	skb_reset_mac_header(skb);
2262 	skb_pull(skb, sizeof(*eth));
2263 	eth = eth_hdr(skb);
2264 	iph = ip_hdr(skb);
2265 	if (iph->version == 4) {
2266 		if (!ipv4_is_multicast(iph->daddr))
2267 			return true;
2268 		skb->protocol = htons(ETH_P_IP);
2269 		eth->h_proto = htons(ETH_P_IP);
2270 		ip_eth_mc_map(iph->daddr, eth->h_dest);
2271 #if IS_ENABLED(CONFIG_IPV6)
2272 	} else if (iph->version == 6) {
2273 		struct ipv6hdr *ip6h;
2274 
2275 		ip6h = ipv6_hdr(skb);
2276 		if (!ipv6_addr_is_multicast(&ip6h->daddr))
2277 			return true;
2278 		skb->protocol = htons(ETH_P_IPV6);
2279 		eth->h_proto = htons(ETH_P_IPV6);
2280 		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2281 #endif
2282 	} else {
2283 		return true;
2284 	}
2285 
2286 	skb->pkt_type = PACKET_MULTICAST;
2287 	skb->ip_summed = CHECKSUM_NONE;
2288 	len = skb->len;
2289 	err = gro_cells_receive(&amt->gro_cells, skb);
2290 	if (likely(err == NET_RX_SUCCESS))
2291 		dev_sw_netstats_rx_add(amt->dev, len);
2292 	else
2293 		amt->dev->stats.rx_dropped++;
2294 
2295 	return false;
2296 }
2297 
2298 static bool amt_membership_query_handler(struct amt_dev *amt,
2299 					 struct sk_buff *skb)
2300 {
2301 	struct amt_header_membership_query *amtmq;
2302 	struct igmpv3_query *ihv3;
2303 	struct ethhdr *eth, *oeth;
2304 	struct iphdr *iph;
2305 	int hdr_size, len;
2306 
2307 	hdr_size = sizeof(*amtmq) - sizeof(struct amt_header);
2308 
2309 	if (!pskb_may_pull(skb, hdr_size))
2310 		return true;
2311 
2312 	amtmq = (struct amt_header_membership_query *)(udp_hdr(skb) + 1);
2313 	if (amtmq->reserved || amtmq->version)
2314 		return true;
2315 
2316 	hdr_size = sizeof(*amtmq) + sizeof(struct udphdr) - sizeof(*eth);
2317 	if (iptunnel_pull_header(skb, hdr_size, htons(ETH_P_TEB), false))
2318 		return true;
2319 	oeth = eth_hdr(skb);
2320 	skb_reset_mac_header(skb);
2321 	skb_pull(skb, sizeof(*eth));
2322 	skb_reset_network_header(skb);
2323 	eth = eth_hdr(skb);
2324 	iph = ip_hdr(skb);
2325 	if (iph->version == 4) {
2326 		if (!ipv4_is_multicast(iph->daddr))
2327 			return true;
2328 		if (!pskb_may_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS +
2329 				   sizeof(*ihv3)))
2330 			return true;
2331 
2332 		ihv3 = skb_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
2333 		skb_reset_transport_header(skb);
2334 		skb_push(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
2335 		spin_lock_bh(&amt->lock);
2336 		amt->ready4 = true;
2337 		amt->mac = amtmq->response_mac;
2338 		amt->req_cnt = 0;
2339 		amt->qi = ihv3->qqic;
2340 		spin_unlock_bh(&amt->lock);
2341 		skb->protocol = htons(ETH_P_IP);
2342 		eth->h_proto = htons(ETH_P_IP);
2343 		ip_eth_mc_map(iph->daddr, eth->h_dest);
2344 #if IS_ENABLED(CONFIG_IPV6)
2345 	} else if (iph->version == 6) {
2346 		struct ipv6hdr *ip6h = ipv6_hdr(skb);
2347 		struct mld2_query *mld2q;
2348 
2349 		if (!ipv6_addr_is_multicast(&ip6h->daddr))
2350 			return true;
2351 		if (!pskb_may_pull(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS +
2352 				   sizeof(*mld2q)))
2353 			return true;
2354 
2355 		mld2q = skb_pull(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS);
2356 		skb_reset_transport_header(skb);
2357 		skb_push(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS);
2358 		spin_lock_bh(&amt->lock);
2359 		amt->ready6 = true;
2360 		amt->mac = amtmq->response_mac;
2361 		amt->req_cnt = 0;
2362 		amt->qi = mld2q->mld2q_qqic;
2363 		spin_unlock_bh(&amt->lock);
2364 		skb->protocol = htons(ETH_P_IPV6);
2365 		eth->h_proto = htons(ETH_P_IPV6);
2366 		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2367 #endif
2368 	} else {
2369 		return true;
2370 	}
2371 
2372 	ether_addr_copy(eth->h_source, oeth->h_source);
2373 	skb->pkt_type = PACKET_MULTICAST;
2374 	skb->ip_summed = CHECKSUM_NONE;
2375 	len = skb->len;
2376 	if (__netif_rx(skb) == NET_RX_SUCCESS) {
2377 		amt_update_gw_status(amt, AMT_STATUS_RECEIVED_QUERY, true);
2378 		dev_sw_netstats_rx_add(amt->dev, len);
2379 	} else {
2380 		amt->dev->stats.rx_dropped++;
2381 	}
2382 
2383 	return false;
2384 }
2385 
2386 static bool amt_update_handler(struct amt_dev *amt, struct sk_buff *skb)
2387 {
2388 	struct amt_header_membership_update *amtmu;
2389 	struct amt_tunnel_list *tunnel;
2390 	struct udphdr *udph;
2391 	struct ethhdr *eth;
2392 	struct iphdr *iph;
2393 	int len;
2394 
2395 	iph = ip_hdr(skb);
2396 	udph = udp_hdr(skb);
2397 
2398 	if (__iptunnel_pull_header(skb, sizeof(*udph), skb->protocol,
2399 				   false, false))
2400 		return true;
2401 
2402 	amtmu = (struct amt_header_membership_update *)skb->data;
2403 	if (amtmu->reserved || amtmu->version)
2404 		return true;
2405 
2406 	skb_pull(skb, sizeof(*amtmu));
2407 	skb_reset_network_header(skb);
2408 
2409 	list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list) {
2410 		if (tunnel->ip4 == iph->saddr) {
2411 			if ((amtmu->nonce == tunnel->nonce &&
2412 			     amtmu->response_mac == tunnel->mac)) {
2413 				mod_delayed_work(amt_wq, &tunnel->gc_wq,
2414 						 msecs_to_jiffies(amt_gmi(amt))
2415 								  * 3);
2416 				goto report;
2417 			} else {
2418 				netdev_dbg(amt->dev, "Invalid MAC\n");
2419 				return true;
2420 			}
2421 		}
2422 	}
2423 
2424 	return false;
2425 
2426 report:
2427 	iph = ip_hdr(skb);
2428 	if (iph->version == 4) {
2429 		if (ip_mc_check_igmp(skb)) {
2430 			netdev_dbg(amt->dev, "Invalid IGMP\n");
2431 			return true;
2432 		}
2433 
2434 		spin_lock_bh(&tunnel->lock);
2435 		amt_igmp_report_handler(amt, skb, tunnel);
2436 		spin_unlock_bh(&tunnel->lock);
2437 
2438 		skb_push(skb, sizeof(struct ethhdr));
2439 		skb_reset_mac_header(skb);
2440 		eth = eth_hdr(skb);
2441 		skb->protocol = htons(ETH_P_IP);
2442 		eth->h_proto = htons(ETH_P_IP);
2443 		ip_eth_mc_map(iph->daddr, eth->h_dest);
2444 #if IS_ENABLED(CONFIG_IPV6)
2445 	} else if (iph->version == 6) {
2446 		struct ipv6hdr *ip6h = ipv6_hdr(skb);
2447 
2448 		if (ipv6_mc_check_mld(skb)) {
2449 			netdev_dbg(amt->dev, "Invalid MLD\n");
2450 			return true;
2451 		}
2452 
2453 		spin_lock_bh(&tunnel->lock);
2454 		amt_mld_report_handler(amt, skb, tunnel);
2455 		spin_unlock_bh(&tunnel->lock);
2456 
2457 		skb_push(skb, sizeof(struct ethhdr));
2458 		skb_reset_mac_header(skb);
2459 		eth = eth_hdr(skb);
2460 		skb->protocol = htons(ETH_P_IPV6);
2461 		eth->h_proto = htons(ETH_P_IPV6);
2462 		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2463 #endif
2464 	} else {
2465 		netdev_dbg(amt->dev, "Unsupported Protocol\n");
2466 		return true;
2467 	}
2468 
2469 	skb_pull(skb, sizeof(struct ethhdr));
2470 	skb->pkt_type = PACKET_MULTICAST;
2471 	skb->ip_summed = CHECKSUM_NONE;
2472 	len = skb->len;
2473 	if (__netif_rx(skb) == NET_RX_SUCCESS) {
2474 		amt_update_relay_status(tunnel, AMT_STATUS_RECEIVED_UPDATE,
2475 					true);
2476 		dev_sw_netstats_rx_add(amt->dev, len);
2477 	} else {
2478 		amt->dev->stats.rx_dropped++;
2479 	}
2480 
2481 	return false;
2482 }
2483 
2484 static void amt_send_advertisement(struct amt_dev *amt, __be32 nonce,
2485 				   __be32 daddr, __be16 dport)
2486 {
2487 	struct amt_header_advertisement *amta;
2488 	int hlen, tlen, offset;
2489 	struct socket *sock;
2490 	struct udphdr *udph;
2491 	struct sk_buff *skb;
2492 	struct iphdr *iph;
2493 	struct rtable *rt;
2494 	struct flowi4 fl4;
2495 	u32 len;
2496 	int err;
2497 
2498 	rcu_read_lock();
2499 	sock = rcu_dereference(amt->sock);
2500 	if (!sock)
2501 		goto out;
2502 
2503 	if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
2504 		goto out;
2505 
2506 	rt = ip_route_output_ports(amt->net, &fl4, sock->sk,
2507 				   daddr, amt->local_ip,
2508 				   dport, amt->relay_port,
2509 				   IPPROTO_UDP, 0,
2510 				   amt->stream_dev->ifindex);
2511 	if (IS_ERR(rt)) {
2512 		amt->dev->stats.tx_errors++;
2513 		goto out;
2514 	}
2515 
2516 	hlen = LL_RESERVED_SPACE(amt->dev);
2517 	tlen = amt->dev->needed_tailroom;
2518 	len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amta);
2519 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
2520 	if (!skb) {
2521 		ip_rt_put(rt);
2522 		amt->dev->stats.tx_errors++;
2523 		goto out;
2524 	}
2525 
2526 	skb->priority = TC_PRIO_CONTROL;
2527 	skb_dst_set(skb, &rt->dst);
2528 
2529 	len = sizeof(*iph) + sizeof(*udph) + sizeof(*amta);
2530 	skb_reset_network_header(skb);
2531 	skb_put(skb, len);
2532 	amta = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
2533 	amta->version	= 0;
2534 	amta->type	= AMT_MSG_ADVERTISEMENT;
2535 	amta->reserved	= 0;
2536 	amta->nonce	= nonce;
2537 	amta->ip4	= amt->local_ip;
2538 	skb_push(skb, sizeof(*udph));
2539 	skb_reset_transport_header(skb);
2540 	udph		= udp_hdr(skb);
2541 	udph->source	= amt->relay_port;
2542 	udph->dest	= dport;
2543 	udph->len	= htons(sizeof(*amta) + sizeof(*udph));
2544 	udph->check	= 0;
2545 	offset = skb_transport_offset(skb);
2546 	skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
2547 	udph->check = csum_tcpudp_magic(amt->local_ip, daddr,
2548 					sizeof(*udph) + sizeof(*amta),
2549 					IPPROTO_UDP, skb->csum);
2550 
2551 	skb_push(skb, sizeof(*iph));
2552 	iph		= ip_hdr(skb);
2553 	iph->version	= 4;
2554 	iph->ihl	= (sizeof(struct iphdr)) >> 2;
2555 	iph->tos	= AMT_TOS;
2556 	iph->frag_off	= 0;
2557 	iph->ttl	= ip4_dst_hoplimit(&rt->dst);
2558 	iph->daddr	= daddr;
2559 	iph->saddr	= amt->local_ip;
2560 	iph->protocol	= IPPROTO_UDP;
2561 	iph->tot_len	= htons(len);
2562 
2563 	skb->ip_summed = CHECKSUM_NONE;
2564 	ip_select_ident(amt->net, skb, NULL);
2565 	ip_send_check(iph);
2566 	err = ip_local_out(amt->net, sock->sk, skb);
2567 	if (unlikely(net_xmit_eval(err)))
2568 		amt->dev->stats.tx_errors++;
2569 
2570 out:
2571 	rcu_read_unlock();
2572 }
2573 
2574 static bool amt_discovery_handler(struct amt_dev *amt, struct sk_buff *skb)
2575 {
2576 	struct amt_header_discovery *amtd;
2577 	struct udphdr *udph;
2578 	struct iphdr *iph;
2579 
2580 	if (!pskb_may_pull(skb, sizeof(*udph) + sizeof(*amtd)))
2581 		return true;
2582 
2583 	iph = ip_hdr(skb);
2584 	udph = udp_hdr(skb);
2585 	amtd = (struct amt_header_discovery *)(udp_hdr(skb) + 1);
2586 
2587 	if (amtd->reserved || amtd->version)
2588 		return true;
2589 
2590 	amt_send_advertisement(amt, amtd->nonce, iph->saddr, udph->source);
2591 
2592 	return false;
2593 }
2594 
2595 static bool amt_request_handler(struct amt_dev *amt, struct sk_buff *skb)
2596 {
2597 	struct amt_header_request *amtrh;
2598 	struct amt_tunnel_list *tunnel;
2599 	unsigned long long key;
2600 	struct udphdr *udph;
2601 	struct iphdr *iph;
2602 	u64 mac;
2603 	int i;
2604 
2605 	if (!pskb_may_pull(skb, sizeof(*udph) + sizeof(*amtrh)))
2606 		return true;
2607 
2608 	iph = ip_hdr(skb);
2609 	udph = udp_hdr(skb);
2610 	amtrh = (struct amt_header_request *)(udp_hdr(skb) + 1);
2611 
2612 	if (amtrh->reserved1 || amtrh->reserved2 || amtrh->version)
2613 		return true;
2614 
2615 	list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list)
2616 		if (tunnel->ip4 == iph->saddr)
2617 			goto send;
2618 
2619 	if (amt->nr_tunnels >= amt->max_tunnels) {
2620 		icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
2621 		return true;
2622 	}
2623 
2624 	tunnel = kzalloc(sizeof(*tunnel) +
2625 			 (sizeof(struct hlist_head) * amt->hash_buckets),
2626 			 GFP_ATOMIC);
2627 	if (!tunnel)
2628 		return true;
2629 
2630 	tunnel->source_port = udph->source;
2631 	tunnel->ip4 = iph->saddr;
2632 
2633 	memcpy(&key, &tunnel->key, sizeof(unsigned long long));
2634 	tunnel->amt = amt;
2635 	spin_lock_init(&tunnel->lock);
2636 	for (i = 0; i < amt->hash_buckets; i++)
2637 		INIT_HLIST_HEAD(&tunnel->groups[i]);
2638 
2639 	INIT_DELAYED_WORK(&tunnel->gc_wq, amt_tunnel_expire);
2640 
2641 	spin_lock_bh(&amt->lock);
2642 	list_add_tail_rcu(&tunnel->list, &amt->tunnel_list);
2643 	tunnel->key = amt->key;
2644 	amt_update_relay_status(tunnel, AMT_STATUS_RECEIVED_REQUEST, true);
2645 	amt->nr_tunnels++;
2646 	mod_delayed_work(amt_wq, &tunnel->gc_wq,
2647 			 msecs_to_jiffies(amt_gmi(amt)));
2648 	spin_unlock_bh(&amt->lock);
2649 
2650 send:
2651 	tunnel->nonce = amtrh->nonce;
2652 	mac = siphash_3u32((__force u32)tunnel->ip4,
2653 			   (__force u32)tunnel->source_port,
2654 			   (__force u32)tunnel->nonce,
2655 			   &tunnel->key);
2656 	tunnel->mac = mac >> 16;
2657 
2658 	if (!netif_running(amt->dev) || !netif_running(amt->stream_dev))
2659 		return true;
2660 
2661 	if (!amtrh->p)
2662 		amt_send_igmp_gq(amt, tunnel);
2663 	else
2664 		amt_send_mld_gq(amt, tunnel);
2665 
2666 	return false;
2667 }
2668 
2669 static int amt_rcv(struct sock *sk, struct sk_buff *skb)
2670 {
2671 	struct amt_dev *amt;
2672 	struct iphdr *iph;
2673 	int type;
2674 	bool err;
2675 
2676 	rcu_read_lock_bh();
2677 	amt = rcu_dereference_sk_user_data(sk);
2678 	if (!amt) {
2679 		err = true;
2680 		goto out;
2681 	}
2682 
2683 	skb->dev = amt->dev;
2684 	iph = ip_hdr(skb);
2685 	type = amt_parse_type(skb);
2686 	if (type == -1) {
2687 		err = true;
2688 		goto drop;
2689 	}
2690 
2691 	if (amt->mode == AMT_MODE_GATEWAY) {
2692 		switch (type) {
2693 		case AMT_MSG_ADVERTISEMENT:
2694 			if (iph->saddr != amt->discovery_ip) {
2695 				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2696 				err = true;
2697 				goto drop;
2698 			}
2699 			if (amt_advertisement_handler(amt, skb))
2700 				amt->dev->stats.rx_dropped++;
2701 			goto out;
2702 		case AMT_MSG_MULTICAST_DATA:
2703 			if (iph->saddr != amt->remote_ip) {
2704 				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2705 				err = true;
2706 				goto drop;
2707 			}
2708 			err = amt_multicast_data_handler(amt, skb);
2709 			if (err)
2710 				goto drop;
2711 			else
2712 				goto out;
2713 		case AMT_MSG_MEMBERSHIP_QUERY:
2714 			if (iph->saddr != amt->remote_ip) {
2715 				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2716 				err = true;
2717 				goto drop;
2718 			}
2719 			err = amt_membership_query_handler(amt, skb);
2720 			if (err)
2721 				goto drop;
2722 			else
2723 				goto out;
2724 		default:
2725 			err = true;
2726 			netdev_dbg(amt->dev, "Invalid type of Gateway\n");
2727 			break;
2728 		}
2729 	} else {
2730 		switch (type) {
2731 		case AMT_MSG_DISCOVERY:
2732 			err = amt_discovery_handler(amt, skb);
2733 			break;
2734 		case AMT_MSG_REQUEST:
2735 			err = amt_request_handler(amt, skb);
2736 			break;
2737 		case AMT_MSG_MEMBERSHIP_UPDATE:
2738 			err = amt_update_handler(amt, skb);
2739 			if (err)
2740 				goto drop;
2741 			else
2742 				goto out;
2743 		default:
2744 			err = true;
2745 			netdev_dbg(amt->dev, "Invalid type of relay\n");
2746 			break;
2747 		}
2748 	}
2749 drop:
2750 	if (err) {
2751 		amt->dev->stats.rx_dropped++;
2752 		kfree_skb(skb);
2753 	} else {
2754 		consume_skb(skb);
2755 	}
2756 out:
2757 	rcu_read_unlock_bh();
2758 	return 0;
2759 }
2760 
2761 static int amt_err_lookup(struct sock *sk, struct sk_buff *skb)
2762 {
2763 	struct amt_dev *amt;
2764 	int type;
2765 
2766 	rcu_read_lock_bh();
2767 	amt = rcu_dereference_sk_user_data(sk);
2768 	if (!amt)
2769 		goto out;
2770 
2771 	if (amt->mode != AMT_MODE_GATEWAY)
2772 		goto drop;
2773 
2774 	type = amt_parse_type(skb);
2775 	if (type == -1)
2776 		goto drop;
2777 
2778 	netdev_dbg(amt->dev, "Received IGMP Unreachable of %s\n",
2779 		   type_str[type]);
2780 	switch (type) {
2781 	case AMT_MSG_DISCOVERY:
2782 		break;
2783 	case AMT_MSG_REQUEST:
2784 	case AMT_MSG_MEMBERSHIP_UPDATE:
2785 		if (amt->status >= AMT_STATUS_RECEIVED_ADVERTISEMENT)
2786 			mod_delayed_work(amt_wq, &amt->req_wq, 0);
2787 		break;
2788 	default:
2789 		goto drop;
2790 	}
2791 out:
2792 	rcu_read_unlock_bh();
2793 	return 0;
2794 drop:
2795 	rcu_read_unlock_bh();
2796 	amt->dev->stats.rx_dropped++;
2797 	return 0;
2798 }
2799 
2800 static struct socket *amt_create_sock(struct net *net, __be16 port)
2801 {
2802 	struct udp_port_cfg udp_conf;
2803 	struct socket *sock;
2804 	int err;
2805 
2806 	memset(&udp_conf, 0, sizeof(udp_conf));
2807 	udp_conf.family = AF_INET;
2808 	udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
2809 
2810 	udp_conf.local_udp_port = port;
2811 
2812 	err = udp_sock_create(net, &udp_conf, &sock);
2813 	if (err < 0)
2814 		return ERR_PTR(err);
2815 
2816 	return sock;
2817 }
2818 
2819 static int amt_socket_create(struct amt_dev *amt)
2820 {
2821 	struct udp_tunnel_sock_cfg tunnel_cfg;
2822 	struct socket *sock;
2823 
2824 	sock = amt_create_sock(amt->net, amt->relay_port);
2825 	if (IS_ERR(sock))
2826 		return PTR_ERR(sock);
2827 
2828 	/* Mark socket as an encapsulation socket */
2829 	memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
2830 	tunnel_cfg.sk_user_data = amt;
2831 	tunnel_cfg.encap_type = 1;
2832 	tunnel_cfg.encap_rcv = amt_rcv;
2833 	tunnel_cfg.encap_err_lookup = amt_err_lookup;
2834 	tunnel_cfg.encap_destroy = NULL;
2835 	setup_udp_tunnel_sock(amt->net, sock, &tunnel_cfg);
2836 
2837 	rcu_assign_pointer(amt->sock, sock);
2838 	return 0;
2839 }
2840 
2841 static int amt_dev_open(struct net_device *dev)
2842 {
2843 	struct amt_dev *amt = netdev_priv(dev);
2844 	int err;
2845 
2846 	amt->ready4 = false;
2847 	amt->ready6 = false;
2848 
2849 	err = amt_socket_create(amt);
2850 	if (err)
2851 		return err;
2852 
2853 	amt->req_cnt = 0;
2854 	amt->remote_ip = 0;
2855 	get_random_bytes(&amt->key, sizeof(siphash_key_t));
2856 
2857 	amt->status = AMT_STATUS_INIT;
2858 	if (amt->mode == AMT_MODE_GATEWAY) {
2859 		mod_delayed_work(amt_wq, &amt->discovery_wq, 0);
2860 		mod_delayed_work(amt_wq, &amt->req_wq, 0);
2861 	} else if (amt->mode == AMT_MODE_RELAY) {
2862 		mod_delayed_work(amt_wq, &amt->secret_wq,
2863 				 msecs_to_jiffies(AMT_SECRET_TIMEOUT));
2864 	}
2865 	return err;
2866 }
2867 
2868 static int amt_dev_stop(struct net_device *dev)
2869 {
2870 	struct amt_dev *amt = netdev_priv(dev);
2871 	struct amt_tunnel_list *tunnel, *tmp;
2872 	struct socket *sock;
2873 
2874 	cancel_delayed_work_sync(&amt->req_wq);
2875 	cancel_delayed_work_sync(&amt->discovery_wq);
2876 	cancel_delayed_work_sync(&amt->secret_wq);
2877 
2878 	/* shutdown */
2879 	sock = rtnl_dereference(amt->sock);
2880 	RCU_INIT_POINTER(amt->sock, NULL);
2881 	synchronize_net();
2882 	if (sock)
2883 		udp_tunnel_sock_release(sock);
2884 
2885 	amt->ready4 = false;
2886 	amt->ready6 = false;
2887 	amt->req_cnt = 0;
2888 	amt->remote_ip = 0;
2889 
2890 	list_for_each_entry_safe(tunnel, tmp, &amt->tunnel_list, list) {
2891 		list_del_rcu(&tunnel->list);
2892 		amt->nr_tunnels--;
2893 		cancel_delayed_work_sync(&tunnel->gc_wq);
2894 		amt_clear_groups(tunnel);
2895 		kfree_rcu(tunnel, rcu);
2896 	}
2897 
2898 	return 0;
2899 }
2900 
2901 static const struct device_type amt_type = {
2902 	.name = "amt",
2903 };
2904 
2905 static int amt_dev_init(struct net_device *dev)
2906 {
2907 	struct amt_dev *amt = netdev_priv(dev);
2908 	int err;
2909 
2910 	amt->dev = dev;
2911 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
2912 	if (!dev->tstats)
2913 		return -ENOMEM;
2914 
2915 	err = gro_cells_init(&amt->gro_cells, dev);
2916 	if (err) {
2917 		free_percpu(dev->tstats);
2918 		return err;
2919 	}
2920 
2921 	return 0;
2922 }
2923 
2924 static void amt_dev_uninit(struct net_device *dev)
2925 {
2926 	struct amt_dev *amt = netdev_priv(dev);
2927 
2928 	gro_cells_destroy(&amt->gro_cells);
2929 	free_percpu(dev->tstats);
2930 }
2931 
2932 static const struct net_device_ops amt_netdev_ops = {
2933 	.ndo_init               = amt_dev_init,
2934 	.ndo_uninit             = amt_dev_uninit,
2935 	.ndo_open		= amt_dev_open,
2936 	.ndo_stop		= amt_dev_stop,
2937 	.ndo_start_xmit         = amt_dev_xmit,
2938 	.ndo_get_stats64        = dev_get_tstats64,
2939 };
2940 
2941 static void amt_link_setup(struct net_device *dev)
2942 {
2943 	dev->netdev_ops         = &amt_netdev_ops;
2944 	dev->needs_free_netdev  = true;
2945 	SET_NETDEV_DEVTYPE(dev, &amt_type);
2946 	dev->min_mtu		= ETH_MIN_MTU;
2947 	dev->max_mtu		= ETH_MAX_MTU;
2948 	dev->type		= ARPHRD_NONE;
2949 	dev->flags		= IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
2950 	dev->hard_header_len	= 0;
2951 	dev->addr_len		= 0;
2952 	dev->priv_flags		|= IFF_NO_QUEUE;
2953 	dev->features		|= NETIF_F_LLTX;
2954 	dev->features		|= NETIF_F_GSO_SOFTWARE;
2955 	dev->features		|= NETIF_F_NETNS_LOCAL;
2956 	dev->hw_features	|= NETIF_F_SG | NETIF_F_HW_CSUM;
2957 	dev->hw_features	|= NETIF_F_FRAGLIST | NETIF_F_RXCSUM;
2958 	dev->hw_features	|= NETIF_F_GSO_SOFTWARE;
2959 	eth_hw_addr_random(dev);
2960 	eth_zero_addr(dev->broadcast);
2961 	ether_setup(dev);
2962 }
2963 
2964 static const struct nla_policy amt_policy[IFLA_AMT_MAX + 1] = {
2965 	[IFLA_AMT_MODE]		= { .type = NLA_U32 },
2966 	[IFLA_AMT_RELAY_PORT]	= { .type = NLA_U16 },
2967 	[IFLA_AMT_GATEWAY_PORT]	= { .type = NLA_U16 },
2968 	[IFLA_AMT_LINK]		= { .type = NLA_U32 },
2969 	[IFLA_AMT_LOCAL_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
2970 	[IFLA_AMT_REMOTE_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
2971 	[IFLA_AMT_DISCOVERY_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
2972 	[IFLA_AMT_MAX_TUNNELS]	= { .type = NLA_U32 },
2973 };
2974 
2975 static int amt_validate(struct nlattr *tb[], struct nlattr *data[],
2976 			struct netlink_ext_ack *extack)
2977 {
2978 	if (!data)
2979 		return -EINVAL;
2980 
2981 	if (!data[IFLA_AMT_LINK]) {
2982 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_LINK],
2983 				    "Link attribute is required");
2984 		return -EINVAL;
2985 	}
2986 
2987 	if (!data[IFLA_AMT_MODE]) {
2988 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_MODE],
2989 				    "Mode attribute is required");
2990 		return -EINVAL;
2991 	}
2992 
2993 	if (nla_get_u32(data[IFLA_AMT_MODE]) > AMT_MODE_MAX) {
2994 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_MODE],
2995 				    "Mode attribute is not valid");
2996 		return -EINVAL;
2997 	}
2998 
2999 	if (!data[IFLA_AMT_LOCAL_IP]) {
3000 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_DISCOVERY_IP],
3001 				    "Local attribute is required");
3002 		return -EINVAL;
3003 	}
3004 
3005 	if (!data[IFLA_AMT_DISCOVERY_IP] &&
3006 	    nla_get_u32(data[IFLA_AMT_MODE]) == AMT_MODE_GATEWAY) {
3007 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_LOCAL_IP],
3008 				    "Discovery attribute is required");
3009 		return -EINVAL;
3010 	}
3011 
3012 	return 0;
3013 }
3014 
3015 static int amt_newlink(struct net *net, struct net_device *dev,
3016 		       struct nlattr *tb[], struct nlattr *data[],
3017 		       struct netlink_ext_ack *extack)
3018 {
3019 	struct amt_dev *amt = netdev_priv(dev);
3020 	int err = -EINVAL;
3021 
3022 	amt->net = net;
3023 	amt->mode = nla_get_u32(data[IFLA_AMT_MODE]);
3024 
3025 	if (data[IFLA_AMT_MAX_TUNNELS] &&
3026 	    nla_get_u32(data[IFLA_AMT_MAX_TUNNELS]))
3027 		amt->max_tunnels = nla_get_u32(data[IFLA_AMT_MAX_TUNNELS]);
3028 	else
3029 		amt->max_tunnels = AMT_MAX_TUNNELS;
3030 
3031 	spin_lock_init(&amt->lock);
3032 	amt->max_groups = AMT_MAX_GROUP;
3033 	amt->max_sources = AMT_MAX_SOURCE;
3034 	amt->hash_buckets = AMT_HSIZE;
3035 	amt->nr_tunnels = 0;
3036 	get_random_bytes(&amt->hash_seed, sizeof(amt->hash_seed));
3037 	amt->stream_dev = dev_get_by_index(net,
3038 					   nla_get_u32(data[IFLA_AMT_LINK]));
3039 	if (!amt->stream_dev) {
3040 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LINK],
3041 				    "Can't find stream device");
3042 		return -ENODEV;
3043 	}
3044 
3045 	if (amt->stream_dev->type != ARPHRD_ETHER) {
3046 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LINK],
3047 				    "Invalid stream device type");
3048 		goto err;
3049 	}
3050 
3051 	amt->local_ip = nla_get_in_addr(data[IFLA_AMT_LOCAL_IP]);
3052 	if (ipv4_is_loopback(amt->local_ip) ||
3053 	    ipv4_is_zeronet(amt->local_ip) ||
3054 	    ipv4_is_multicast(amt->local_ip)) {
3055 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LOCAL_IP],
3056 				    "Invalid Local address");
3057 		goto err;
3058 	}
3059 
3060 	if (data[IFLA_AMT_RELAY_PORT])
3061 		amt->relay_port = nla_get_be16(data[IFLA_AMT_RELAY_PORT]);
3062 	else
3063 		amt->relay_port = htons(IANA_AMT_UDP_PORT);
3064 
3065 	if (data[IFLA_AMT_GATEWAY_PORT])
3066 		amt->gw_port = nla_get_be16(data[IFLA_AMT_GATEWAY_PORT]);
3067 	else
3068 		amt->gw_port = htons(IANA_AMT_UDP_PORT);
3069 
3070 	if (!amt->relay_port) {
3071 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3072 				    "relay port must not be 0");
3073 		goto err;
3074 	}
3075 	if (amt->mode == AMT_MODE_RELAY) {
3076 		amt->qrv = amt->net->ipv4.sysctl_igmp_qrv;
3077 		amt->qri = 10;
3078 		dev->needed_headroom = amt->stream_dev->needed_headroom +
3079 				       AMT_RELAY_HLEN;
3080 		dev->mtu = amt->stream_dev->mtu - AMT_RELAY_HLEN;
3081 		dev->max_mtu = dev->mtu;
3082 		dev->min_mtu = ETH_MIN_MTU + AMT_RELAY_HLEN;
3083 	} else {
3084 		if (!data[IFLA_AMT_DISCOVERY_IP]) {
3085 			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3086 					    "discovery must be set in gateway mode");
3087 			goto err;
3088 		}
3089 		if (!amt->gw_port) {
3090 			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3091 					    "gateway port must not be 0");
3092 			goto err;
3093 		}
3094 		amt->remote_ip = 0;
3095 		amt->discovery_ip = nla_get_in_addr(data[IFLA_AMT_DISCOVERY_IP]);
3096 		if (ipv4_is_loopback(amt->discovery_ip) ||
3097 		    ipv4_is_zeronet(amt->discovery_ip) ||
3098 		    ipv4_is_multicast(amt->discovery_ip)) {
3099 			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3100 					    "discovery must be unicast");
3101 			goto err;
3102 		}
3103 
3104 		dev->needed_headroom = amt->stream_dev->needed_headroom +
3105 				       AMT_GW_HLEN;
3106 		dev->mtu = amt->stream_dev->mtu - AMT_GW_HLEN;
3107 		dev->max_mtu = dev->mtu;
3108 		dev->min_mtu = ETH_MIN_MTU + AMT_GW_HLEN;
3109 	}
3110 	amt->qi = AMT_INIT_QUERY_INTERVAL;
3111 
3112 	err = register_netdevice(dev);
3113 	if (err < 0) {
3114 		netdev_dbg(dev, "failed to register new netdev %d\n", err);
3115 		goto err;
3116 	}
3117 
3118 	err = netdev_upper_dev_link(amt->stream_dev, dev, extack);
3119 	if (err < 0) {
3120 		unregister_netdevice(dev);
3121 		goto err;
3122 	}
3123 
3124 	INIT_DELAYED_WORK(&amt->discovery_wq, amt_discovery_work);
3125 	INIT_DELAYED_WORK(&amt->req_wq, amt_req_work);
3126 	INIT_DELAYED_WORK(&amt->secret_wq, amt_secret_work);
3127 	INIT_LIST_HEAD(&amt->tunnel_list);
3128 
3129 	return 0;
3130 err:
3131 	dev_put(amt->stream_dev);
3132 	return err;
3133 }
3134 
3135 static void amt_dellink(struct net_device *dev, struct list_head *head)
3136 {
3137 	struct amt_dev *amt = netdev_priv(dev);
3138 
3139 	unregister_netdevice_queue(dev, head);
3140 	netdev_upper_dev_unlink(amt->stream_dev, dev);
3141 	dev_put(amt->stream_dev);
3142 }
3143 
3144 static size_t amt_get_size(const struct net_device *dev)
3145 {
3146 	return nla_total_size(sizeof(__u32)) + /* IFLA_AMT_MODE */
3147 	       nla_total_size(sizeof(__u16)) + /* IFLA_AMT_RELAY_PORT */
3148 	       nla_total_size(sizeof(__u16)) + /* IFLA_AMT_GATEWAY_PORT */
3149 	       nla_total_size(sizeof(__u32)) + /* IFLA_AMT_LINK */
3150 	       nla_total_size(sizeof(__u32)) + /* IFLA_MAX_TUNNELS */
3151 	       nla_total_size(sizeof(struct iphdr)) + /* IFLA_AMT_DISCOVERY_IP */
3152 	       nla_total_size(sizeof(struct iphdr)) + /* IFLA_AMT_REMOTE_IP */
3153 	       nla_total_size(sizeof(struct iphdr)); /* IFLA_AMT_LOCAL_IP */
3154 }
3155 
3156 static int amt_fill_info(struct sk_buff *skb, const struct net_device *dev)
3157 {
3158 	struct amt_dev *amt = netdev_priv(dev);
3159 
3160 	if (nla_put_u32(skb, IFLA_AMT_MODE, amt->mode))
3161 		goto nla_put_failure;
3162 	if (nla_put_be16(skb, IFLA_AMT_RELAY_PORT, amt->relay_port))
3163 		goto nla_put_failure;
3164 	if (nla_put_be16(skb, IFLA_AMT_GATEWAY_PORT, amt->gw_port))
3165 		goto nla_put_failure;
3166 	if (nla_put_u32(skb, IFLA_AMT_LINK, amt->stream_dev->ifindex))
3167 		goto nla_put_failure;
3168 	if (nla_put_in_addr(skb, IFLA_AMT_LOCAL_IP, amt->local_ip))
3169 		goto nla_put_failure;
3170 	if (nla_put_in_addr(skb, IFLA_AMT_DISCOVERY_IP, amt->discovery_ip))
3171 		goto nla_put_failure;
3172 	if (amt->remote_ip)
3173 		if (nla_put_in_addr(skb, IFLA_AMT_REMOTE_IP, amt->remote_ip))
3174 			goto nla_put_failure;
3175 	if (nla_put_u32(skb, IFLA_AMT_MAX_TUNNELS, amt->max_tunnels))
3176 		goto nla_put_failure;
3177 
3178 	return 0;
3179 
3180 nla_put_failure:
3181 	return -EMSGSIZE;
3182 }
3183 
3184 static struct rtnl_link_ops amt_link_ops __read_mostly = {
3185 	.kind		= "amt",
3186 	.maxtype	= IFLA_AMT_MAX,
3187 	.policy		= amt_policy,
3188 	.priv_size	= sizeof(struct amt_dev),
3189 	.setup		= amt_link_setup,
3190 	.validate	= amt_validate,
3191 	.newlink	= amt_newlink,
3192 	.dellink	= amt_dellink,
3193 	.get_size       = amt_get_size,
3194 	.fill_info      = amt_fill_info,
3195 };
3196 
3197 static struct net_device *amt_lookup_upper_dev(struct net_device *dev)
3198 {
3199 	struct net_device *upper_dev;
3200 	struct amt_dev *amt;
3201 
3202 	for_each_netdev(dev_net(dev), upper_dev) {
3203 		if (netif_is_amt(upper_dev)) {
3204 			amt = netdev_priv(upper_dev);
3205 			if (amt->stream_dev == dev)
3206 				return upper_dev;
3207 		}
3208 	}
3209 
3210 	return NULL;
3211 }
3212 
3213 static int amt_device_event(struct notifier_block *unused,
3214 			    unsigned long event, void *ptr)
3215 {
3216 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3217 	struct net_device *upper_dev;
3218 	struct amt_dev *amt;
3219 	LIST_HEAD(list);
3220 	int new_mtu;
3221 
3222 	upper_dev = amt_lookup_upper_dev(dev);
3223 	if (!upper_dev)
3224 		return NOTIFY_DONE;
3225 	amt = netdev_priv(upper_dev);
3226 
3227 	switch (event) {
3228 	case NETDEV_UNREGISTER:
3229 		amt_dellink(amt->dev, &list);
3230 		unregister_netdevice_many(&list);
3231 		break;
3232 	case NETDEV_CHANGEMTU:
3233 		if (amt->mode == AMT_MODE_RELAY)
3234 			new_mtu = dev->mtu - AMT_RELAY_HLEN;
3235 		else
3236 			new_mtu = dev->mtu - AMT_GW_HLEN;
3237 
3238 		dev_set_mtu(amt->dev, new_mtu);
3239 		break;
3240 	}
3241 
3242 	return NOTIFY_DONE;
3243 }
3244 
3245 static struct notifier_block amt_notifier_block __read_mostly = {
3246 	.notifier_call = amt_device_event,
3247 };
3248 
3249 static int __init amt_init(void)
3250 {
3251 	int err;
3252 
3253 	err = register_netdevice_notifier(&amt_notifier_block);
3254 	if (err < 0)
3255 		goto err;
3256 
3257 	err = rtnl_link_register(&amt_link_ops);
3258 	if (err < 0)
3259 		goto unregister_notifier;
3260 
3261 	amt_wq = alloc_workqueue("amt", WQ_UNBOUND, 1);
3262 	if (!amt_wq) {
3263 		err = -ENOMEM;
3264 		goto rtnl_unregister;
3265 	}
3266 
3267 	spin_lock_init(&source_gc_lock);
3268 	spin_lock_bh(&source_gc_lock);
3269 	INIT_DELAYED_WORK(&source_gc_wq, amt_source_gc_work);
3270 	mod_delayed_work(amt_wq, &source_gc_wq,
3271 			 msecs_to_jiffies(AMT_GC_INTERVAL));
3272 	spin_unlock_bh(&source_gc_lock);
3273 
3274 	return 0;
3275 
3276 rtnl_unregister:
3277 	rtnl_link_unregister(&amt_link_ops);
3278 unregister_notifier:
3279 	unregister_netdevice_notifier(&amt_notifier_block);
3280 err:
3281 	pr_err("error loading AMT module loaded\n");
3282 	return err;
3283 }
3284 late_initcall(amt_init);
3285 
3286 static void __exit amt_fini(void)
3287 {
3288 	rtnl_link_unregister(&amt_link_ops);
3289 	unregister_netdevice_notifier(&amt_notifier_block);
3290 	cancel_delayed_work_sync(&source_gc_wq);
3291 	__amt_source_gc_work();
3292 	destroy_workqueue(amt_wq);
3293 }
3294 module_exit(amt_fini);
3295 
3296 MODULE_LICENSE("GPL");
3297 MODULE_AUTHOR("Taehee Yoo <ap420073@gmail.com>");
3298 MODULE_ALIAS_RTNL_LINK("amt");
3299