xref: /linux/drivers/net/amt.c (revision a7ddedc84c59a645ef970b992f7cda5bffc70cc0)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Copyright (c) 2021 Taehee Yoo <ap420073@gmail.com> */
3 
4 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
5 
6 #include <linux/module.h>
7 #include <linux/skbuff.h>
8 #include <linux/udp.h>
9 #include <linux/jhash.h>
10 #include <linux/if_tunnel.h>
11 #include <linux/net.h>
12 #include <linux/igmp.h>
13 #include <linux/workqueue.h>
14 #include <net/flow.h>
15 #include <net/pkt_sched.h>
16 #include <net/net_namespace.h>
17 #include <net/ip.h>
18 #include <net/udp.h>
19 #include <net/udp_tunnel.h>
20 #include <net/icmp.h>
21 #include <net/mld.h>
22 #include <net/amt.h>
23 #include <uapi/linux/amt.h>
24 #include <linux/security.h>
25 #include <net/gro_cells.h>
26 #include <net/ipv6.h>
27 #include <net/if_inet6.h>
28 #include <net/ndisc.h>
29 #include <net/addrconf.h>
30 #include <net/ip6_route.h>
31 #include <net/inet_common.h>
32 #include <net/inet_dscp.h>
33 #include <net/ip6_checksum.h>
34 
35 static struct workqueue_struct *amt_wq;
36 
37 static HLIST_HEAD(source_gc_list);
38 /* Lock for source_gc_list */
39 static spinlock_t source_gc_lock;
40 static struct delayed_work source_gc_wq;
41 static char *status_str[] = {
42 	"AMT_STATUS_INIT",
43 	"AMT_STATUS_SENT_DISCOVERY",
44 	"AMT_STATUS_RECEIVED_DISCOVERY",
45 	"AMT_STATUS_SENT_ADVERTISEMENT",
46 	"AMT_STATUS_RECEIVED_ADVERTISEMENT",
47 	"AMT_STATUS_SENT_REQUEST",
48 	"AMT_STATUS_RECEIVED_REQUEST",
49 	"AMT_STATUS_SENT_QUERY",
50 	"AMT_STATUS_RECEIVED_QUERY",
51 	"AMT_STATUS_SENT_UPDATE",
52 	"AMT_STATUS_RECEIVED_UPDATE",
53 };
54 
55 static char *type_str[] = {
56 	"", /* Type 0 is not defined */
57 	"AMT_MSG_DISCOVERY",
58 	"AMT_MSG_ADVERTISEMENT",
59 	"AMT_MSG_REQUEST",
60 	"AMT_MSG_MEMBERSHIP_QUERY",
61 	"AMT_MSG_MEMBERSHIP_UPDATE",
62 	"AMT_MSG_MULTICAST_DATA",
63 	"AMT_MSG_TEARDOWN",
64 };
65 
66 static char *action_str[] = {
67 	"AMT_ACT_GMI",
68 	"AMT_ACT_GMI_ZERO",
69 	"AMT_ACT_GT",
70 	"AMT_ACT_STATUS_FWD_NEW",
71 	"AMT_ACT_STATUS_D_FWD_NEW",
72 	"AMT_ACT_STATUS_NONE_NEW",
73 };
74 
75 static struct igmpv3_grec igmpv3_zero_grec;
76 
77 #if IS_ENABLED(CONFIG_IPV6)
78 #define MLD2_ALL_NODE_INIT { { { 0xff, 0x02, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x01 } } }
79 static struct in6_addr mld2_all_node = MLD2_ALL_NODE_INIT;
80 static struct mld2_grec mldv2_zero_grec;
81 #endif
82 
83 static struct amt_skb_cb *amt_skb_cb(struct sk_buff *skb)
84 {
85 	BUILD_BUG_ON(sizeof(struct amt_skb_cb) + sizeof(struct tc_skb_cb) >
86 		     sizeof_field(struct sk_buff, cb));
87 
88 	return (struct amt_skb_cb *)((void *)skb->cb +
89 		sizeof(struct tc_skb_cb));
90 }
91 
92 static void __amt_source_gc_work(void)
93 {
94 	struct amt_source_node *snode;
95 	struct hlist_head gc_list;
96 	struct hlist_node *t;
97 
98 	spin_lock_bh(&source_gc_lock);
99 	hlist_move_list(&source_gc_list, &gc_list);
100 	spin_unlock_bh(&source_gc_lock);
101 
102 	hlist_for_each_entry_safe(snode, t, &gc_list, node) {
103 		hlist_del_rcu(&snode->node);
104 		kfree_rcu(snode, rcu);
105 	}
106 }
107 
108 static void amt_source_gc_work(struct work_struct *work)
109 {
110 	__amt_source_gc_work();
111 
112 	spin_lock_bh(&source_gc_lock);
113 	mod_delayed_work(amt_wq, &source_gc_wq,
114 			 msecs_to_jiffies(AMT_GC_INTERVAL));
115 	spin_unlock_bh(&source_gc_lock);
116 }
117 
118 static bool amt_addr_equal(union amt_addr *a, union amt_addr *b)
119 {
120 	return !memcmp(a, b, sizeof(union amt_addr));
121 }
122 
123 static u32 amt_source_hash(struct amt_tunnel_list *tunnel, union amt_addr *src)
124 {
125 	u32 hash = jhash(src, sizeof(*src), tunnel->amt->hash_seed);
126 
127 	return reciprocal_scale(hash, tunnel->amt->hash_buckets);
128 }
129 
130 static bool amt_status_filter(struct amt_source_node *snode,
131 			      enum amt_filter filter)
132 {
133 	bool rc = false;
134 
135 	switch (filter) {
136 	case AMT_FILTER_FWD:
137 		if (snode->status == AMT_SOURCE_STATUS_FWD &&
138 		    snode->flags == AMT_SOURCE_OLD)
139 			rc = true;
140 		break;
141 	case AMT_FILTER_D_FWD:
142 		if (snode->status == AMT_SOURCE_STATUS_D_FWD &&
143 		    snode->flags == AMT_SOURCE_OLD)
144 			rc = true;
145 		break;
146 	case AMT_FILTER_FWD_NEW:
147 		if (snode->status == AMT_SOURCE_STATUS_FWD &&
148 		    snode->flags == AMT_SOURCE_NEW)
149 			rc = true;
150 		break;
151 	case AMT_FILTER_D_FWD_NEW:
152 		if (snode->status == AMT_SOURCE_STATUS_D_FWD &&
153 		    snode->flags == AMT_SOURCE_NEW)
154 			rc = true;
155 		break;
156 	case AMT_FILTER_ALL:
157 		rc = true;
158 		break;
159 	case AMT_FILTER_NONE_NEW:
160 		if (snode->status == AMT_SOURCE_STATUS_NONE &&
161 		    snode->flags == AMT_SOURCE_NEW)
162 			rc = true;
163 		break;
164 	case AMT_FILTER_BOTH:
165 		if ((snode->status == AMT_SOURCE_STATUS_D_FWD ||
166 		     snode->status == AMT_SOURCE_STATUS_FWD) &&
167 		    snode->flags == AMT_SOURCE_OLD)
168 			rc = true;
169 		break;
170 	case AMT_FILTER_BOTH_NEW:
171 		if ((snode->status == AMT_SOURCE_STATUS_D_FWD ||
172 		     snode->status == AMT_SOURCE_STATUS_FWD) &&
173 		    snode->flags == AMT_SOURCE_NEW)
174 			rc = true;
175 		break;
176 	default:
177 		WARN_ON_ONCE(1);
178 		break;
179 	}
180 
181 	return rc;
182 }
183 
184 static struct amt_source_node *amt_lookup_src(struct amt_tunnel_list *tunnel,
185 					      struct amt_group_node *gnode,
186 					      enum amt_filter filter,
187 					      union amt_addr *src)
188 {
189 	u32 hash = amt_source_hash(tunnel, src);
190 	struct amt_source_node *snode;
191 
192 	hlist_for_each_entry_rcu(snode, &gnode->sources[hash], node)
193 		if (amt_status_filter(snode, filter) &&
194 		    amt_addr_equal(&snode->source_addr, src))
195 			return snode;
196 
197 	return NULL;
198 }
199 
200 static u32 amt_group_hash(struct amt_tunnel_list *tunnel, union amt_addr *group)
201 {
202 	u32 hash = jhash(group, sizeof(*group), tunnel->amt->hash_seed);
203 
204 	return reciprocal_scale(hash, tunnel->amt->hash_buckets);
205 }
206 
207 static struct amt_group_node *amt_lookup_group(struct amt_tunnel_list *tunnel,
208 					       union amt_addr *group,
209 					       union amt_addr *host,
210 					       bool v6)
211 {
212 	u32 hash = amt_group_hash(tunnel, group);
213 	struct amt_group_node *gnode;
214 
215 	hlist_for_each_entry_rcu(gnode, &tunnel->groups[hash], node) {
216 		if (amt_addr_equal(&gnode->group_addr, group) &&
217 		    amt_addr_equal(&gnode->host_addr, host) &&
218 		    gnode->v6 == v6)
219 			return gnode;
220 	}
221 
222 	return NULL;
223 }
224 
225 static void amt_destroy_source(struct amt_source_node *snode)
226 {
227 	struct amt_group_node *gnode = snode->gnode;
228 	struct amt_tunnel_list *tunnel;
229 
230 	tunnel = gnode->tunnel_list;
231 
232 	if (!gnode->v6) {
233 		netdev_dbg(snode->gnode->amt->dev,
234 			   "Delete source %pI4 from %pI4\n",
235 			   &snode->source_addr.ip4,
236 			   &gnode->group_addr.ip4);
237 #if IS_ENABLED(CONFIG_IPV6)
238 	} else {
239 		netdev_dbg(snode->gnode->amt->dev,
240 			   "Delete source %pI6 from %pI6\n",
241 			   &snode->source_addr.ip6,
242 			   &gnode->group_addr.ip6);
243 #endif
244 	}
245 
246 	cancel_delayed_work(&snode->source_timer);
247 	hlist_del_init_rcu(&snode->node);
248 	tunnel->nr_sources--;
249 	gnode->nr_sources--;
250 	spin_lock_bh(&source_gc_lock);
251 	hlist_add_head_rcu(&snode->node, &source_gc_list);
252 	spin_unlock_bh(&source_gc_lock);
253 }
254 
255 static void amt_del_group(struct amt_dev *amt, struct amt_group_node *gnode)
256 {
257 	struct amt_source_node *snode;
258 	struct hlist_node *t;
259 	int i;
260 
261 	if (cancel_delayed_work(&gnode->group_timer))
262 		dev_put(amt->dev);
263 	hlist_del_rcu(&gnode->node);
264 	gnode->tunnel_list->nr_groups--;
265 
266 	if (!gnode->v6)
267 		netdev_dbg(amt->dev, "Leave group %pI4\n",
268 			   &gnode->group_addr.ip4);
269 #if IS_ENABLED(CONFIG_IPV6)
270 	else
271 		netdev_dbg(amt->dev, "Leave group %pI6\n",
272 			   &gnode->group_addr.ip6);
273 #endif
274 	for (i = 0; i < amt->hash_buckets; i++)
275 		hlist_for_each_entry_safe(snode, t, &gnode->sources[i], node)
276 			amt_destroy_source(snode);
277 
278 	/* tunnel->lock was acquired outside of amt_del_group()
279 	 * But rcu_read_lock() was acquired too so It's safe.
280 	 */
281 	kfree_rcu(gnode, rcu);
282 }
283 
284 /* If a source timer expires with a router filter-mode for the group of
285  * INCLUDE, the router concludes that traffic from this particular
286  * source is no longer desired on the attached network, and deletes the
287  * associated source record.
288  */
289 static void amt_source_work(struct work_struct *work)
290 {
291 	struct amt_source_node *snode = container_of(to_delayed_work(work),
292 						     struct amt_source_node,
293 						     source_timer);
294 	struct amt_group_node *gnode = snode->gnode;
295 	struct amt_dev *amt = gnode->amt;
296 	struct amt_tunnel_list *tunnel;
297 
298 	tunnel = gnode->tunnel_list;
299 	spin_lock_bh(&tunnel->lock);
300 	rcu_read_lock();
301 	if (gnode->filter_mode == MCAST_INCLUDE) {
302 		amt_destroy_source(snode);
303 		if (!gnode->nr_sources)
304 			amt_del_group(amt, gnode);
305 	} else {
306 		/* When a router filter-mode for a group is EXCLUDE,
307 		 * source records are only deleted when the group timer expires
308 		 */
309 		snode->status = AMT_SOURCE_STATUS_D_FWD;
310 	}
311 	rcu_read_unlock();
312 	spin_unlock_bh(&tunnel->lock);
313 }
314 
315 static void amt_act_src(struct amt_tunnel_list *tunnel,
316 			struct amt_group_node *gnode,
317 			struct amt_source_node *snode,
318 			enum amt_act act)
319 {
320 	struct amt_dev *amt = tunnel->amt;
321 
322 	switch (act) {
323 	case AMT_ACT_GMI:
324 		mod_delayed_work(amt_wq, &snode->source_timer,
325 				 msecs_to_jiffies(amt_gmi(amt)));
326 		break;
327 	case AMT_ACT_GMI_ZERO:
328 		cancel_delayed_work(&snode->source_timer);
329 		break;
330 	case AMT_ACT_GT:
331 		mod_delayed_work(amt_wq, &snode->source_timer,
332 				 gnode->group_timer.timer.expires);
333 		break;
334 	case AMT_ACT_STATUS_FWD_NEW:
335 		snode->status = AMT_SOURCE_STATUS_FWD;
336 		snode->flags = AMT_SOURCE_NEW;
337 		break;
338 	case AMT_ACT_STATUS_D_FWD_NEW:
339 		snode->status = AMT_SOURCE_STATUS_D_FWD;
340 		snode->flags = AMT_SOURCE_NEW;
341 		break;
342 	case AMT_ACT_STATUS_NONE_NEW:
343 		cancel_delayed_work(&snode->source_timer);
344 		snode->status = AMT_SOURCE_STATUS_NONE;
345 		snode->flags = AMT_SOURCE_NEW;
346 		break;
347 	default:
348 		WARN_ON_ONCE(1);
349 		return;
350 	}
351 
352 	if (!gnode->v6)
353 		netdev_dbg(amt->dev, "Source %pI4 from %pI4 Acted %s\n",
354 			   &snode->source_addr.ip4,
355 			   &gnode->group_addr.ip4,
356 			   action_str[act]);
357 #if IS_ENABLED(CONFIG_IPV6)
358 	else
359 		netdev_dbg(amt->dev, "Source %pI6 from %pI6 Acted %s\n",
360 			   &snode->source_addr.ip6,
361 			   &gnode->group_addr.ip6,
362 			   action_str[act]);
363 #endif
364 }
365 
366 static struct amt_source_node *amt_alloc_snode(struct amt_group_node *gnode,
367 					       union amt_addr *src)
368 {
369 	struct amt_source_node *snode;
370 
371 	snode = kzalloc(sizeof(*snode), GFP_ATOMIC);
372 	if (!snode)
373 		return NULL;
374 
375 	memcpy(&snode->source_addr, src, sizeof(union amt_addr));
376 	snode->gnode = gnode;
377 	snode->status = AMT_SOURCE_STATUS_NONE;
378 	snode->flags = AMT_SOURCE_NEW;
379 	INIT_HLIST_NODE(&snode->node);
380 	INIT_DELAYED_WORK(&snode->source_timer, amt_source_work);
381 
382 	return snode;
383 }
384 
385 /* RFC 3810 - 7.2.2.  Definition of Filter Timers
386  *
387  *  Router Mode          Filter Timer         Actions/Comments
388  *  -----------       -----------------       ----------------
389  *
390  *    INCLUDE             Not Used            All listeners in
391  *                                            INCLUDE mode.
392  *
393  *    EXCLUDE             Timer > 0           At least one listener
394  *                                            in EXCLUDE mode.
395  *
396  *    EXCLUDE             Timer == 0          No more listeners in
397  *                                            EXCLUDE mode for the
398  *                                            multicast address.
399  *                                            If the Requested List
400  *                                            is empty, delete
401  *                                            Multicast Address
402  *                                            Record.  If not, switch
403  *                                            to INCLUDE filter mode;
404  *                                            the sources in the
405  *                                            Requested List are
406  *                                            moved to the Include
407  *                                            List, and the Exclude
408  *                                            List is deleted.
409  */
410 static void amt_group_work(struct work_struct *work)
411 {
412 	struct amt_group_node *gnode = container_of(to_delayed_work(work),
413 						    struct amt_group_node,
414 						    group_timer);
415 	struct amt_tunnel_list *tunnel = gnode->tunnel_list;
416 	struct amt_dev *amt = gnode->amt;
417 	struct amt_source_node *snode;
418 	bool delete_group = true;
419 	struct hlist_node *t;
420 	int i, buckets;
421 
422 	buckets = amt->hash_buckets;
423 
424 	spin_lock_bh(&tunnel->lock);
425 	if (gnode->filter_mode == MCAST_INCLUDE) {
426 		/* Not Used */
427 		spin_unlock_bh(&tunnel->lock);
428 		goto out;
429 	}
430 
431 	rcu_read_lock();
432 	for (i = 0; i < buckets; i++) {
433 		hlist_for_each_entry_safe(snode, t,
434 					  &gnode->sources[i], node) {
435 			if (!delayed_work_pending(&snode->source_timer) ||
436 			    snode->status == AMT_SOURCE_STATUS_D_FWD) {
437 				amt_destroy_source(snode);
438 			} else {
439 				delete_group = false;
440 				snode->status = AMT_SOURCE_STATUS_FWD;
441 			}
442 		}
443 	}
444 	if (delete_group)
445 		amt_del_group(amt, gnode);
446 	else
447 		gnode->filter_mode = MCAST_INCLUDE;
448 	rcu_read_unlock();
449 	spin_unlock_bh(&tunnel->lock);
450 out:
451 	dev_put(amt->dev);
452 }
453 
454 /* Non-existent group is created as INCLUDE {empty}:
455  *
456  * RFC 3376 - 5.1. Action on Change of Interface State
457  *
458  * If no interface state existed for that multicast address before
459  * the change (i.e., the change consisted of creating a new
460  * per-interface record), or if no state exists after the change
461  * (i.e., the change consisted of deleting a per-interface record),
462  * then the "non-existent" state is considered to have a filter mode
463  * of INCLUDE and an empty source list.
464  */
465 static struct amt_group_node *amt_add_group(struct amt_dev *amt,
466 					    struct amt_tunnel_list *tunnel,
467 					    union amt_addr *group,
468 					    union amt_addr *host,
469 					    bool v6)
470 {
471 	struct amt_group_node *gnode;
472 	u32 hash;
473 	int i;
474 
475 	if (tunnel->nr_groups >= amt->max_groups)
476 		return ERR_PTR(-ENOSPC);
477 
478 	gnode = kzalloc(sizeof(*gnode) +
479 			(sizeof(struct hlist_head) * amt->hash_buckets),
480 			GFP_ATOMIC);
481 	if (unlikely(!gnode))
482 		return ERR_PTR(-ENOMEM);
483 
484 	gnode->amt = amt;
485 	gnode->group_addr = *group;
486 	gnode->host_addr = *host;
487 	gnode->v6 = v6;
488 	gnode->tunnel_list = tunnel;
489 	gnode->filter_mode = MCAST_INCLUDE;
490 	INIT_HLIST_NODE(&gnode->node);
491 	INIT_DELAYED_WORK(&gnode->group_timer, amt_group_work);
492 	for (i = 0; i < amt->hash_buckets; i++)
493 		INIT_HLIST_HEAD(&gnode->sources[i]);
494 
495 	hash = amt_group_hash(tunnel, group);
496 	hlist_add_head_rcu(&gnode->node, &tunnel->groups[hash]);
497 	tunnel->nr_groups++;
498 
499 	if (!gnode->v6)
500 		netdev_dbg(amt->dev, "Join group %pI4\n",
501 			   &gnode->group_addr.ip4);
502 #if IS_ENABLED(CONFIG_IPV6)
503 	else
504 		netdev_dbg(amt->dev, "Join group %pI6\n",
505 			   &gnode->group_addr.ip6);
506 #endif
507 
508 	return gnode;
509 }
510 
511 static struct sk_buff *amt_build_igmp_gq(struct amt_dev *amt)
512 {
513 	u8 ra[AMT_IPHDR_OPTS] = { IPOPT_RA, 4, 0, 0 };
514 	int hlen = LL_RESERVED_SPACE(amt->dev);
515 	int tlen = amt->dev->needed_tailroom;
516 	struct igmpv3_query *ihv3;
517 	void *csum_start = NULL;
518 	__sum16 *csum = NULL;
519 	struct sk_buff *skb;
520 	struct ethhdr *eth;
521 	struct iphdr *iph;
522 	unsigned int len;
523 	int offset;
524 
525 	len = hlen + tlen + sizeof(*iph) + AMT_IPHDR_OPTS + sizeof(*ihv3);
526 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
527 	if (!skb)
528 		return NULL;
529 
530 	skb_reserve(skb, hlen);
531 	skb_push(skb, sizeof(*eth));
532 	skb->protocol = htons(ETH_P_IP);
533 	skb_reset_mac_header(skb);
534 	skb->priority = TC_PRIO_CONTROL;
535 	skb_put(skb, sizeof(*iph));
536 	skb_put_data(skb, ra, sizeof(ra));
537 	skb_put(skb, sizeof(*ihv3));
538 	skb_pull(skb, sizeof(*eth));
539 	skb_reset_network_header(skb);
540 
541 	iph		= ip_hdr(skb);
542 	iph->version	= 4;
543 	iph->ihl	= (sizeof(struct iphdr) + AMT_IPHDR_OPTS) >> 2;
544 	iph->tos	= AMT_TOS;
545 	iph->tot_len	= htons(sizeof(*iph) + AMT_IPHDR_OPTS + sizeof(*ihv3));
546 	iph->frag_off	= htons(IP_DF);
547 	iph->ttl	= 1;
548 	iph->id		= 0;
549 	iph->protocol	= IPPROTO_IGMP;
550 	iph->daddr	= htonl(INADDR_ALLHOSTS_GROUP);
551 	iph->saddr	= htonl(INADDR_ANY);
552 	ip_send_check(iph);
553 
554 	eth = eth_hdr(skb);
555 	ether_addr_copy(eth->h_source, amt->dev->dev_addr);
556 	ip_eth_mc_map(htonl(INADDR_ALLHOSTS_GROUP), eth->h_dest);
557 	eth->h_proto = htons(ETH_P_IP);
558 
559 	ihv3		= skb_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
560 	skb_reset_transport_header(skb);
561 	ihv3->type	= IGMP_HOST_MEMBERSHIP_QUERY;
562 	ihv3->code	= 1;
563 	ihv3->group	= 0;
564 	ihv3->qqic	= amt->qi;
565 	ihv3->nsrcs	= 0;
566 	ihv3->resv	= 0;
567 	ihv3->suppress	= false;
568 	ihv3->qrv	= READ_ONCE(amt->net->ipv4.sysctl_igmp_qrv);
569 	ihv3->csum	= 0;
570 	csum		= &ihv3->csum;
571 	csum_start	= (void *)ihv3;
572 	*csum		= ip_compute_csum(csum_start, sizeof(*ihv3));
573 	offset		= skb_transport_offset(skb);
574 	skb->csum	= skb_checksum(skb, offset, skb->len - offset, 0);
575 	skb->ip_summed	= CHECKSUM_NONE;
576 
577 	skb_push(skb, sizeof(*eth) + sizeof(*iph) + AMT_IPHDR_OPTS);
578 
579 	return skb;
580 }
581 
582 static void amt_update_gw_status(struct amt_dev *amt, enum amt_status status,
583 				 bool validate)
584 {
585 	if (validate && amt->status >= status)
586 		return;
587 	netdev_dbg(amt->dev, "Update GW status %s -> %s",
588 		   status_str[amt->status], status_str[status]);
589 	WRITE_ONCE(amt->status, status);
590 }
591 
592 static void __amt_update_relay_status(struct amt_tunnel_list *tunnel,
593 				      enum amt_status status,
594 				      bool validate)
595 {
596 	if (validate && tunnel->status >= status)
597 		return;
598 	netdev_dbg(tunnel->amt->dev,
599 		   "Update Tunnel(IP = %pI4, PORT = %u) status %s -> %s",
600 		   &tunnel->ip4, ntohs(tunnel->source_port),
601 		   status_str[tunnel->status], status_str[status]);
602 	tunnel->status = status;
603 }
604 
605 static void amt_update_relay_status(struct amt_tunnel_list *tunnel,
606 				    enum amt_status status, bool validate)
607 {
608 	spin_lock_bh(&tunnel->lock);
609 	__amt_update_relay_status(tunnel, status, validate);
610 	spin_unlock_bh(&tunnel->lock);
611 }
612 
613 static void amt_send_discovery(struct amt_dev *amt)
614 {
615 	struct amt_header_discovery *amtd;
616 	int hlen, tlen, offset;
617 	struct socket *sock;
618 	struct udphdr *udph;
619 	struct sk_buff *skb;
620 	struct iphdr *iph;
621 	struct rtable *rt;
622 	struct flowi4 fl4;
623 	u32 len;
624 	int err;
625 
626 	rcu_read_lock();
627 	sock = rcu_dereference(amt->sock);
628 	if (!sock)
629 		goto out;
630 
631 	if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
632 		goto out;
633 
634 	rt = ip_route_output_ports(amt->net, &fl4, sock->sk,
635 				   amt->discovery_ip, amt->local_ip,
636 				   amt->gw_port, amt->relay_port,
637 				   IPPROTO_UDP, 0,
638 				   amt->stream_dev->ifindex);
639 	if (IS_ERR(rt)) {
640 		amt->dev->stats.tx_errors++;
641 		goto out;
642 	}
643 
644 	hlen = LL_RESERVED_SPACE(amt->dev);
645 	tlen = amt->dev->needed_tailroom;
646 	len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amtd);
647 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
648 	if (!skb) {
649 		ip_rt_put(rt);
650 		amt->dev->stats.tx_errors++;
651 		goto out;
652 	}
653 
654 	skb->priority = TC_PRIO_CONTROL;
655 	skb_dst_set(skb, &rt->dst);
656 
657 	len = sizeof(*iph) + sizeof(*udph) + sizeof(*amtd);
658 	skb_reset_network_header(skb);
659 	skb_put(skb, len);
660 	amtd = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
661 	amtd->version	= 0;
662 	amtd->type	= AMT_MSG_DISCOVERY;
663 	amtd->reserved	= 0;
664 	amtd->nonce	= amt->nonce;
665 	skb_push(skb, sizeof(*udph));
666 	skb_reset_transport_header(skb);
667 	udph		= udp_hdr(skb);
668 	udph->source	= amt->gw_port;
669 	udph->dest	= amt->relay_port;
670 	udph->len	= htons(sizeof(*udph) + sizeof(*amtd));
671 	udph->check	= 0;
672 	offset = skb_transport_offset(skb);
673 	skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
674 	udph->check = csum_tcpudp_magic(amt->local_ip, amt->discovery_ip,
675 					sizeof(*udph) + sizeof(*amtd),
676 					IPPROTO_UDP, skb->csum);
677 
678 	skb_push(skb, sizeof(*iph));
679 	iph		= ip_hdr(skb);
680 	iph->version	= 4;
681 	iph->ihl	= (sizeof(struct iphdr)) >> 2;
682 	iph->tos	= AMT_TOS;
683 	iph->frag_off	= 0;
684 	iph->ttl	= ip4_dst_hoplimit(&rt->dst);
685 	iph->daddr	= amt->discovery_ip;
686 	iph->saddr	= amt->local_ip;
687 	iph->protocol	= IPPROTO_UDP;
688 	iph->tot_len	= htons(len);
689 
690 	skb->ip_summed = CHECKSUM_NONE;
691 	ip_select_ident(amt->net, skb, NULL);
692 	ip_send_check(iph);
693 	err = ip_local_out(amt->net, sock->sk, skb);
694 	if (unlikely(net_xmit_eval(err)))
695 		amt->dev->stats.tx_errors++;
696 
697 	amt_update_gw_status(amt, AMT_STATUS_SENT_DISCOVERY, true);
698 out:
699 	rcu_read_unlock();
700 }
701 
702 static void amt_send_request(struct amt_dev *amt, bool v6)
703 {
704 	struct amt_header_request *amtrh;
705 	int hlen, tlen, offset;
706 	struct socket *sock;
707 	struct udphdr *udph;
708 	struct sk_buff *skb;
709 	struct iphdr *iph;
710 	struct rtable *rt;
711 	struct flowi4 fl4;
712 	u32 len;
713 	int err;
714 
715 	rcu_read_lock();
716 	sock = rcu_dereference(amt->sock);
717 	if (!sock)
718 		goto out;
719 
720 	if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
721 		goto out;
722 
723 	rt = ip_route_output_ports(amt->net, &fl4, sock->sk,
724 				   amt->remote_ip, amt->local_ip,
725 				   amt->gw_port, amt->relay_port,
726 				   IPPROTO_UDP, 0,
727 				   amt->stream_dev->ifindex);
728 	if (IS_ERR(rt)) {
729 		amt->dev->stats.tx_errors++;
730 		goto out;
731 	}
732 
733 	hlen = LL_RESERVED_SPACE(amt->dev);
734 	tlen = amt->dev->needed_tailroom;
735 	len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amtrh);
736 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
737 	if (!skb) {
738 		ip_rt_put(rt);
739 		amt->dev->stats.tx_errors++;
740 		goto out;
741 	}
742 
743 	skb->priority = TC_PRIO_CONTROL;
744 	skb_dst_set(skb, &rt->dst);
745 
746 	len = sizeof(*iph) + sizeof(*udph) + sizeof(*amtrh);
747 	skb_reset_network_header(skb);
748 	skb_put(skb, len);
749 	amtrh = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
750 	amtrh->version	 = 0;
751 	amtrh->type	 = AMT_MSG_REQUEST;
752 	amtrh->reserved1 = 0;
753 	amtrh->p	 = v6;
754 	amtrh->reserved2 = 0;
755 	amtrh->nonce	 = amt->nonce;
756 	skb_push(skb, sizeof(*udph));
757 	skb_reset_transport_header(skb);
758 	udph		= udp_hdr(skb);
759 	udph->source	= amt->gw_port;
760 	udph->dest	= amt->relay_port;
761 	udph->len	= htons(sizeof(*amtrh) + sizeof(*udph));
762 	udph->check	= 0;
763 	offset = skb_transport_offset(skb);
764 	skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
765 	udph->check = csum_tcpudp_magic(amt->local_ip, amt->remote_ip,
766 					sizeof(*udph) + sizeof(*amtrh),
767 					IPPROTO_UDP, skb->csum);
768 
769 	skb_push(skb, sizeof(*iph));
770 	iph		= ip_hdr(skb);
771 	iph->version	= 4;
772 	iph->ihl	= (sizeof(struct iphdr)) >> 2;
773 	iph->tos	= AMT_TOS;
774 	iph->frag_off	= 0;
775 	iph->ttl	= ip4_dst_hoplimit(&rt->dst);
776 	iph->daddr	= amt->remote_ip;
777 	iph->saddr	= amt->local_ip;
778 	iph->protocol	= IPPROTO_UDP;
779 	iph->tot_len	= htons(len);
780 
781 	skb->ip_summed = CHECKSUM_NONE;
782 	ip_select_ident(amt->net, skb, NULL);
783 	ip_send_check(iph);
784 	err = ip_local_out(amt->net, sock->sk, skb);
785 	if (unlikely(net_xmit_eval(err)))
786 		amt->dev->stats.tx_errors++;
787 
788 out:
789 	rcu_read_unlock();
790 }
791 
792 static void amt_send_igmp_gq(struct amt_dev *amt,
793 			     struct amt_tunnel_list *tunnel)
794 {
795 	struct sk_buff *skb;
796 
797 	skb = amt_build_igmp_gq(amt);
798 	if (!skb)
799 		return;
800 
801 	amt_skb_cb(skb)->tunnel = tunnel;
802 	dev_queue_xmit(skb);
803 }
804 
805 #if IS_ENABLED(CONFIG_IPV6)
806 static struct sk_buff *amt_build_mld_gq(struct amt_dev *amt)
807 {
808 	u8 ra[AMT_IP6HDR_OPTS] = { IPPROTO_ICMPV6, 0, IPV6_TLV_ROUTERALERT,
809 				   2, 0, 0, IPV6_TLV_PAD1, IPV6_TLV_PAD1 };
810 	int hlen = LL_RESERVED_SPACE(amt->dev);
811 	int tlen = amt->dev->needed_tailroom;
812 	struct mld2_query *mld2q;
813 	void *csum_start = NULL;
814 	struct ipv6hdr *ip6h;
815 	struct sk_buff *skb;
816 	struct ethhdr *eth;
817 	u32 len;
818 
819 	len = hlen + tlen + sizeof(*ip6h) + sizeof(ra) + sizeof(*mld2q);
820 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
821 	if (!skb)
822 		return NULL;
823 
824 	skb_reserve(skb, hlen);
825 	skb_push(skb, sizeof(*eth));
826 	skb_reset_mac_header(skb);
827 	eth = eth_hdr(skb);
828 	skb->priority = TC_PRIO_CONTROL;
829 	skb->protocol = htons(ETH_P_IPV6);
830 	skb_put_zero(skb, sizeof(*ip6h));
831 	skb_put_data(skb, ra, sizeof(ra));
832 	skb_put_zero(skb, sizeof(*mld2q));
833 	skb_pull(skb, sizeof(*eth));
834 	skb_reset_network_header(skb);
835 	ip6h			= ipv6_hdr(skb);
836 	ip6h->payload_len	= htons(sizeof(ra) + sizeof(*mld2q));
837 	ip6h->nexthdr		= NEXTHDR_HOP;
838 	ip6h->hop_limit		= 1;
839 	ip6h->daddr		= mld2_all_node;
840 	ip6_flow_hdr(ip6h, 0, 0);
841 
842 	if (ipv6_dev_get_saddr(amt->net, amt->dev, &ip6h->daddr, 0,
843 			       &ip6h->saddr)) {
844 		amt->dev->stats.tx_errors++;
845 		kfree_skb(skb);
846 		return NULL;
847 	}
848 
849 	eth->h_proto = htons(ETH_P_IPV6);
850 	ether_addr_copy(eth->h_source, amt->dev->dev_addr);
851 	ipv6_eth_mc_map(&mld2_all_node, eth->h_dest);
852 
853 	skb_pull(skb, sizeof(*ip6h) + sizeof(ra));
854 	skb_reset_transport_header(skb);
855 	mld2q			= (struct mld2_query *)icmp6_hdr(skb);
856 	mld2q->mld2q_mrc	= htons(1);
857 	mld2q->mld2q_type	= ICMPV6_MGM_QUERY;
858 	mld2q->mld2q_code	= 0;
859 	mld2q->mld2q_cksum	= 0;
860 	mld2q->mld2q_resv1	= 0;
861 	mld2q->mld2q_resv2	= 0;
862 	mld2q->mld2q_suppress	= 0;
863 	mld2q->mld2q_qrv	= amt->qrv;
864 	mld2q->mld2q_nsrcs	= 0;
865 	mld2q->mld2q_qqic	= amt->qi;
866 	csum_start		= (void *)mld2q;
867 	mld2q->mld2q_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
868 					     sizeof(*mld2q),
869 					     IPPROTO_ICMPV6,
870 					     csum_partial(csum_start,
871 							  sizeof(*mld2q), 0));
872 
873 	skb->ip_summed = CHECKSUM_NONE;
874 	skb_push(skb, sizeof(*eth) + sizeof(*ip6h) + sizeof(ra));
875 	return skb;
876 }
877 
878 static void amt_send_mld_gq(struct amt_dev *amt, struct amt_tunnel_list *tunnel)
879 {
880 	struct sk_buff *skb;
881 
882 	skb = amt_build_mld_gq(amt);
883 	if (!skb)
884 		return;
885 
886 	amt_skb_cb(skb)->tunnel = tunnel;
887 	dev_queue_xmit(skb);
888 }
889 #else
890 static void amt_send_mld_gq(struct amt_dev *amt, struct amt_tunnel_list *tunnel)
891 {
892 }
893 #endif
894 
895 static bool amt_queue_event(struct amt_dev *amt, enum amt_event event,
896 			    struct sk_buff *skb)
897 {
898 	int index;
899 
900 	spin_lock_bh(&amt->lock);
901 	if (amt->nr_events >= AMT_MAX_EVENTS) {
902 		spin_unlock_bh(&amt->lock);
903 		return 1;
904 	}
905 
906 	index = (amt->event_idx + amt->nr_events) % AMT_MAX_EVENTS;
907 	amt->events[index].event = event;
908 	amt->events[index].skb = skb;
909 	amt->nr_events++;
910 	amt->event_idx %= AMT_MAX_EVENTS;
911 	queue_work(amt_wq, &amt->event_wq);
912 	spin_unlock_bh(&amt->lock);
913 
914 	return 0;
915 }
916 
917 static void amt_secret_work(struct work_struct *work)
918 {
919 	struct amt_dev *amt = container_of(to_delayed_work(work),
920 					   struct amt_dev,
921 					   secret_wq);
922 
923 	spin_lock_bh(&amt->lock);
924 	get_random_bytes(&amt->key, sizeof(siphash_key_t));
925 	spin_unlock_bh(&amt->lock);
926 	mod_delayed_work(amt_wq, &amt->secret_wq,
927 			 msecs_to_jiffies(AMT_SECRET_TIMEOUT));
928 }
929 
930 static void amt_event_send_discovery(struct amt_dev *amt)
931 {
932 	if (amt->status > AMT_STATUS_SENT_DISCOVERY)
933 		goto out;
934 	get_random_bytes(&amt->nonce, sizeof(__be32));
935 
936 	amt_send_discovery(amt);
937 out:
938 	mod_delayed_work(amt_wq, &amt->discovery_wq,
939 			 msecs_to_jiffies(AMT_DISCOVERY_TIMEOUT));
940 }
941 
942 static void amt_discovery_work(struct work_struct *work)
943 {
944 	struct amt_dev *amt = container_of(to_delayed_work(work),
945 					   struct amt_dev,
946 					   discovery_wq);
947 
948 	if (amt_queue_event(amt, AMT_EVENT_SEND_DISCOVERY, NULL))
949 		mod_delayed_work(amt_wq, &amt->discovery_wq,
950 				 msecs_to_jiffies(AMT_DISCOVERY_TIMEOUT));
951 }
952 
953 static void amt_event_send_request(struct amt_dev *amt)
954 {
955 	u32 exp;
956 
957 	if (amt->status < AMT_STATUS_RECEIVED_ADVERTISEMENT)
958 		goto out;
959 
960 	if (amt->req_cnt > AMT_MAX_REQ_COUNT) {
961 		netdev_dbg(amt->dev, "Gateway is not ready");
962 		amt->qi = AMT_INIT_REQ_TIMEOUT;
963 		WRITE_ONCE(amt->ready4, false);
964 		WRITE_ONCE(amt->ready6, false);
965 		amt->remote_ip = 0;
966 		amt_update_gw_status(amt, AMT_STATUS_INIT, false);
967 		amt->req_cnt = 0;
968 		amt->nonce = 0;
969 		goto out;
970 	}
971 
972 	if (!amt->req_cnt) {
973 		WRITE_ONCE(amt->ready4, false);
974 		WRITE_ONCE(amt->ready6, false);
975 		get_random_bytes(&amt->nonce, sizeof(__be32));
976 	}
977 
978 	amt_send_request(amt, false);
979 	amt_send_request(amt, true);
980 	amt_update_gw_status(amt, AMT_STATUS_SENT_REQUEST, true);
981 	amt->req_cnt++;
982 out:
983 	exp = min_t(u32, (1 * (1 << amt->req_cnt)), AMT_MAX_REQ_TIMEOUT);
984 	mod_delayed_work(amt_wq, &amt->req_wq, secs_to_jiffies(exp));
985 }
986 
987 static void amt_req_work(struct work_struct *work)
988 {
989 	struct amt_dev *amt = container_of(to_delayed_work(work),
990 					   struct amt_dev,
991 					   req_wq);
992 
993 	if (amt_queue_event(amt, AMT_EVENT_SEND_REQUEST, NULL))
994 		mod_delayed_work(amt_wq, &amt->req_wq,
995 				 msecs_to_jiffies(100));
996 }
997 
998 static bool amt_send_membership_update(struct amt_dev *amt,
999 				       struct sk_buff *skb,
1000 				       bool v6)
1001 {
1002 	struct amt_header_membership_update *amtmu;
1003 	struct socket *sock;
1004 	struct iphdr *iph;
1005 	struct flowi4 fl4;
1006 	struct rtable *rt;
1007 	int err;
1008 
1009 	sock = rcu_dereference_bh(amt->sock);
1010 	if (!sock)
1011 		return true;
1012 
1013 	err = skb_cow_head(skb, LL_RESERVED_SPACE(amt->dev) + sizeof(*amtmu) +
1014 			   sizeof(*iph) + sizeof(struct udphdr));
1015 	if (err)
1016 		return true;
1017 
1018 	skb_reset_inner_headers(skb);
1019 	memset(&fl4, 0, sizeof(struct flowi4));
1020 	fl4.flowi4_oif         = amt->stream_dev->ifindex;
1021 	fl4.daddr              = amt->remote_ip;
1022 	fl4.saddr              = amt->local_ip;
1023 	fl4.flowi4_dscp        = inet_dsfield_to_dscp(AMT_TOS);
1024 	fl4.flowi4_proto       = IPPROTO_UDP;
1025 	rt = ip_route_output_key(amt->net, &fl4);
1026 	if (IS_ERR(rt)) {
1027 		netdev_dbg(amt->dev, "no route to %pI4\n", &amt->remote_ip);
1028 		return true;
1029 	}
1030 
1031 	amtmu			= skb_push(skb, sizeof(*amtmu));
1032 	amtmu->version		= 0;
1033 	amtmu->type		= AMT_MSG_MEMBERSHIP_UPDATE;
1034 	amtmu->reserved		= 0;
1035 	amtmu->nonce		= amt->nonce;
1036 	amtmu->response_mac	= amt->mac;
1037 
1038 	if (!v6)
1039 		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1040 	else
1041 		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1042 	udp_tunnel_xmit_skb(rt, sock->sk, skb,
1043 			    fl4.saddr,
1044 			    fl4.daddr,
1045 			    AMT_TOS,
1046 			    ip4_dst_hoplimit(&rt->dst),
1047 			    0,
1048 			    amt->gw_port,
1049 			    amt->relay_port,
1050 			    false,
1051 			    false,
1052 			    0);
1053 	amt_update_gw_status(amt, AMT_STATUS_SENT_UPDATE, true);
1054 	return false;
1055 }
1056 
1057 static void amt_send_multicast_data(struct amt_dev *amt,
1058 				    const struct sk_buff *oskb,
1059 				    struct amt_tunnel_list *tunnel,
1060 				    bool v6)
1061 {
1062 	struct amt_header_mcast_data *amtmd;
1063 	struct socket *sock;
1064 	struct sk_buff *skb;
1065 	struct iphdr *iph;
1066 	struct flowi4 fl4;
1067 	struct rtable *rt;
1068 
1069 	sock = rcu_dereference_bh(amt->sock);
1070 	if (!sock)
1071 		return;
1072 
1073 	skb = skb_copy_expand(oskb, sizeof(*amtmd) + sizeof(*iph) +
1074 			      sizeof(struct udphdr), 0, GFP_ATOMIC);
1075 	if (!skb)
1076 		return;
1077 
1078 	skb_reset_inner_headers(skb);
1079 	memset(&fl4, 0, sizeof(struct flowi4));
1080 	fl4.flowi4_oif         = amt->stream_dev->ifindex;
1081 	fl4.daddr              = tunnel->ip4;
1082 	fl4.saddr              = amt->local_ip;
1083 	fl4.flowi4_proto       = IPPROTO_UDP;
1084 	rt = ip_route_output_key(amt->net, &fl4);
1085 	if (IS_ERR(rt)) {
1086 		netdev_dbg(amt->dev, "no route to %pI4\n", &tunnel->ip4);
1087 		kfree_skb(skb);
1088 		return;
1089 	}
1090 
1091 	amtmd = skb_push(skb, sizeof(*amtmd));
1092 	amtmd->version = 0;
1093 	amtmd->reserved = 0;
1094 	amtmd->type = AMT_MSG_MULTICAST_DATA;
1095 
1096 	if (!v6)
1097 		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1098 	else
1099 		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1100 	udp_tunnel_xmit_skb(rt, sock->sk, skb,
1101 			    fl4.saddr,
1102 			    fl4.daddr,
1103 			    AMT_TOS,
1104 			    ip4_dst_hoplimit(&rt->dst),
1105 			    0,
1106 			    amt->relay_port,
1107 			    tunnel->source_port,
1108 			    false,
1109 			    false,
1110 			    0);
1111 }
1112 
1113 static bool amt_send_membership_query(struct amt_dev *amt,
1114 				      struct sk_buff *skb,
1115 				      struct amt_tunnel_list *tunnel,
1116 				      bool v6)
1117 {
1118 	struct amt_header_membership_query *amtmq;
1119 	struct socket *sock;
1120 	struct rtable *rt;
1121 	struct flowi4 fl4;
1122 	int err;
1123 
1124 	sock = rcu_dereference_bh(amt->sock);
1125 	if (!sock)
1126 		return true;
1127 
1128 	err = skb_cow_head(skb, LL_RESERVED_SPACE(amt->dev) + sizeof(*amtmq) +
1129 			   sizeof(struct iphdr) + sizeof(struct udphdr));
1130 	if (err)
1131 		return true;
1132 
1133 	skb_reset_inner_headers(skb);
1134 	memset(&fl4, 0, sizeof(struct flowi4));
1135 	fl4.flowi4_oif         = amt->stream_dev->ifindex;
1136 	fl4.daddr              = tunnel->ip4;
1137 	fl4.saddr              = amt->local_ip;
1138 	fl4.flowi4_dscp        = inet_dsfield_to_dscp(AMT_TOS);
1139 	fl4.flowi4_proto       = IPPROTO_UDP;
1140 	rt = ip_route_output_key(amt->net, &fl4);
1141 	if (IS_ERR(rt)) {
1142 		netdev_dbg(amt->dev, "no route to %pI4\n", &tunnel->ip4);
1143 		return true;
1144 	}
1145 
1146 	amtmq		= skb_push(skb, sizeof(*amtmq));
1147 	amtmq->version	= 0;
1148 	amtmq->type	= AMT_MSG_MEMBERSHIP_QUERY;
1149 	amtmq->reserved = 0;
1150 	amtmq->l	= 0;
1151 	amtmq->g	= 0;
1152 	amtmq->nonce	= tunnel->nonce;
1153 	amtmq->response_mac = tunnel->mac;
1154 
1155 	if (!v6)
1156 		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1157 	else
1158 		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1159 	udp_tunnel_xmit_skb(rt, sock->sk, skb,
1160 			    fl4.saddr,
1161 			    fl4.daddr,
1162 			    AMT_TOS,
1163 			    ip4_dst_hoplimit(&rt->dst),
1164 			    0,
1165 			    amt->relay_port,
1166 			    tunnel->source_port,
1167 			    false,
1168 			    false,
1169 			    0);
1170 	amt_update_relay_status(tunnel, AMT_STATUS_SENT_QUERY, true);
1171 	return false;
1172 }
1173 
1174 static netdev_tx_t amt_dev_xmit(struct sk_buff *skb, struct net_device *dev)
1175 {
1176 	struct amt_dev *amt = netdev_priv(dev);
1177 	struct amt_tunnel_list *tunnel;
1178 	struct amt_group_node *gnode;
1179 	union amt_addr group = {0,};
1180 #if IS_ENABLED(CONFIG_IPV6)
1181 	struct ipv6hdr *ip6h;
1182 	struct mld_msg *mld;
1183 #endif
1184 	bool report = false;
1185 	struct igmphdr *ih;
1186 	bool query = false;
1187 	struct iphdr *iph;
1188 	bool data = false;
1189 	bool v6 = false;
1190 	u32 hash;
1191 
1192 	iph = ip_hdr(skb);
1193 	if (iph->version == 4) {
1194 		if (!ipv4_is_multicast(iph->daddr))
1195 			goto free;
1196 
1197 		if (!ip_mc_check_igmp(skb)) {
1198 			ih = igmp_hdr(skb);
1199 			switch (ih->type) {
1200 			case IGMPV3_HOST_MEMBERSHIP_REPORT:
1201 			case IGMP_HOST_MEMBERSHIP_REPORT:
1202 				report = true;
1203 				break;
1204 			case IGMP_HOST_MEMBERSHIP_QUERY:
1205 				query = true;
1206 				break;
1207 			default:
1208 				goto free;
1209 			}
1210 		} else {
1211 			data = true;
1212 		}
1213 		v6 = false;
1214 		group.ip4 = iph->daddr;
1215 #if IS_ENABLED(CONFIG_IPV6)
1216 	} else if (iph->version == 6) {
1217 		ip6h = ipv6_hdr(skb);
1218 		if (!ipv6_addr_is_multicast(&ip6h->daddr))
1219 			goto free;
1220 
1221 		if (!ipv6_mc_check_mld(skb)) {
1222 			mld = (struct mld_msg *)skb_transport_header(skb);
1223 			switch (mld->mld_type) {
1224 			case ICMPV6_MGM_REPORT:
1225 			case ICMPV6_MLD2_REPORT:
1226 				report = true;
1227 				break;
1228 			case ICMPV6_MGM_QUERY:
1229 				query = true;
1230 				break;
1231 			default:
1232 				goto free;
1233 			}
1234 		} else {
1235 			data = true;
1236 		}
1237 		v6 = true;
1238 		group.ip6 = ip6h->daddr;
1239 #endif
1240 	} else {
1241 		dev->stats.tx_errors++;
1242 		goto free;
1243 	}
1244 
1245 	if (!pskb_may_pull(skb, sizeof(struct ethhdr)))
1246 		goto free;
1247 
1248 	skb_pull(skb, sizeof(struct ethhdr));
1249 
1250 	if (amt->mode == AMT_MODE_GATEWAY) {
1251 		/* Gateway only passes IGMP/MLD packets */
1252 		if (!report)
1253 			goto free;
1254 		if ((!v6 && !READ_ONCE(amt->ready4)) ||
1255 		    (v6 && !READ_ONCE(amt->ready6)))
1256 			goto free;
1257 		if (amt_send_membership_update(amt, skb,  v6))
1258 			goto free;
1259 		goto unlock;
1260 	} else if (amt->mode == AMT_MODE_RELAY) {
1261 		if (query) {
1262 			tunnel = amt_skb_cb(skb)->tunnel;
1263 			if (!tunnel) {
1264 				WARN_ON(1);
1265 				goto free;
1266 			}
1267 
1268 			/* Do not forward unexpected query */
1269 			if (amt_send_membership_query(amt, skb, tunnel, v6))
1270 				goto free;
1271 			goto unlock;
1272 		}
1273 
1274 		if (!data)
1275 			goto free;
1276 		list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list) {
1277 			hash = amt_group_hash(tunnel, &group);
1278 			hlist_for_each_entry_rcu(gnode, &tunnel->groups[hash],
1279 						 node) {
1280 				if (!v6) {
1281 					if (gnode->group_addr.ip4 == iph->daddr)
1282 						goto found;
1283 #if IS_ENABLED(CONFIG_IPV6)
1284 				} else {
1285 					if (ipv6_addr_equal(&gnode->group_addr.ip6,
1286 							    &ip6h->daddr))
1287 						goto found;
1288 #endif
1289 				}
1290 			}
1291 			continue;
1292 found:
1293 			amt_send_multicast_data(amt, skb, tunnel, v6);
1294 		}
1295 	}
1296 
1297 	dev_kfree_skb(skb);
1298 	return NETDEV_TX_OK;
1299 free:
1300 	dev_kfree_skb(skb);
1301 unlock:
1302 	dev->stats.tx_dropped++;
1303 	return NETDEV_TX_OK;
1304 }
1305 
1306 static int amt_parse_type(struct sk_buff *skb)
1307 {
1308 	struct amt_header *amth;
1309 
1310 	if (!pskb_may_pull(skb, sizeof(struct udphdr) +
1311 			   sizeof(struct amt_header)))
1312 		return -1;
1313 
1314 	amth = (struct amt_header *)(udp_hdr(skb) + 1);
1315 
1316 	if (amth->version != 0)
1317 		return -1;
1318 
1319 	if (amth->type >= __AMT_MSG_MAX || !amth->type)
1320 		return -1;
1321 	return amth->type;
1322 }
1323 
1324 static void amt_clear_groups(struct amt_tunnel_list *tunnel)
1325 {
1326 	struct amt_dev *amt = tunnel->amt;
1327 	struct amt_group_node *gnode;
1328 	struct hlist_node *t;
1329 	int i;
1330 
1331 	spin_lock_bh(&tunnel->lock);
1332 	rcu_read_lock();
1333 	for (i = 0; i < amt->hash_buckets; i++)
1334 		hlist_for_each_entry_safe(gnode, t, &tunnel->groups[i], node)
1335 			amt_del_group(amt, gnode);
1336 	rcu_read_unlock();
1337 	spin_unlock_bh(&tunnel->lock);
1338 }
1339 
1340 static void amt_tunnel_expire(struct work_struct *work)
1341 {
1342 	struct amt_tunnel_list *tunnel = container_of(to_delayed_work(work),
1343 						      struct amt_tunnel_list,
1344 						      gc_wq);
1345 	struct amt_dev *amt = tunnel->amt;
1346 
1347 	spin_lock_bh(&amt->lock);
1348 	rcu_read_lock();
1349 	list_del_rcu(&tunnel->list);
1350 	amt->nr_tunnels--;
1351 	amt_clear_groups(tunnel);
1352 	rcu_read_unlock();
1353 	spin_unlock_bh(&amt->lock);
1354 	kfree_rcu(tunnel, rcu);
1355 }
1356 
1357 static void amt_cleanup_srcs(struct amt_dev *amt,
1358 			     struct amt_tunnel_list *tunnel,
1359 			     struct amt_group_node *gnode)
1360 {
1361 	struct amt_source_node *snode;
1362 	struct hlist_node *t;
1363 	int i;
1364 
1365 	/* Delete old sources */
1366 	for (i = 0; i < amt->hash_buckets; i++) {
1367 		hlist_for_each_entry_safe(snode, t, &gnode->sources[i], node) {
1368 			if (snode->flags == AMT_SOURCE_OLD)
1369 				amt_destroy_source(snode);
1370 		}
1371 	}
1372 
1373 	/* switch from new to old */
1374 	for (i = 0; i < amt->hash_buckets; i++)  {
1375 		hlist_for_each_entry_rcu(snode, &gnode->sources[i], node) {
1376 			snode->flags = AMT_SOURCE_OLD;
1377 			if (!gnode->v6)
1378 				netdev_dbg(snode->gnode->amt->dev,
1379 					   "Add source as OLD %pI4 from %pI4\n",
1380 					   &snode->source_addr.ip4,
1381 					   &gnode->group_addr.ip4);
1382 #if IS_ENABLED(CONFIG_IPV6)
1383 			else
1384 				netdev_dbg(snode->gnode->amt->dev,
1385 					   "Add source as OLD %pI6 from %pI6\n",
1386 					   &snode->source_addr.ip6,
1387 					   &gnode->group_addr.ip6);
1388 #endif
1389 		}
1390 	}
1391 }
1392 
1393 static void amt_add_srcs(struct amt_dev *amt, struct amt_tunnel_list *tunnel,
1394 			 struct amt_group_node *gnode, void *grec,
1395 			 bool v6)
1396 {
1397 	struct igmpv3_grec *igmp_grec;
1398 	struct amt_source_node *snode;
1399 #if IS_ENABLED(CONFIG_IPV6)
1400 	struct mld2_grec *mld_grec;
1401 #endif
1402 	union amt_addr src = {0,};
1403 	u16 nsrcs;
1404 	u32 hash;
1405 	int i;
1406 
1407 	if (!v6) {
1408 		igmp_grec = grec;
1409 		nsrcs = ntohs(igmp_grec->grec_nsrcs);
1410 	} else {
1411 #if IS_ENABLED(CONFIG_IPV6)
1412 		mld_grec = grec;
1413 		nsrcs = ntohs(mld_grec->grec_nsrcs);
1414 #else
1415 	return;
1416 #endif
1417 	}
1418 	for (i = 0; i < nsrcs; i++) {
1419 		if (tunnel->nr_sources >= amt->max_sources)
1420 			return;
1421 		if (!v6)
1422 			src.ip4 = igmp_grec->grec_src[i];
1423 #if IS_ENABLED(CONFIG_IPV6)
1424 		else
1425 			memcpy(&src.ip6, &mld_grec->grec_src[i],
1426 			       sizeof(struct in6_addr));
1427 #endif
1428 		if (amt_lookup_src(tunnel, gnode, AMT_FILTER_ALL, &src))
1429 			continue;
1430 
1431 		snode = amt_alloc_snode(gnode, &src);
1432 		if (snode) {
1433 			hash = amt_source_hash(tunnel, &snode->source_addr);
1434 			hlist_add_head_rcu(&snode->node, &gnode->sources[hash]);
1435 			tunnel->nr_sources++;
1436 			gnode->nr_sources++;
1437 
1438 			if (!gnode->v6)
1439 				netdev_dbg(snode->gnode->amt->dev,
1440 					   "Add source as NEW %pI4 from %pI4\n",
1441 					   &snode->source_addr.ip4,
1442 					   &gnode->group_addr.ip4);
1443 #if IS_ENABLED(CONFIG_IPV6)
1444 			else
1445 				netdev_dbg(snode->gnode->amt->dev,
1446 					   "Add source as NEW %pI6 from %pI6\n",
1447 					   &snode->source_addr.ip6,
1448 					   &gnode->group_addr.ip6);
1449 #endif
1450 		}
1451 	}
1452 }
1453 
1454 /* Router State   Report Rec'd New Router State
1455  * ------------   ------------ ----------------
1456  * EXCLUDE (X,Y)  IS_IN (A)    EXCLUDE (X+A,Y-A)
1457  *
1458  * -----------+-----------+-----------+
1459  *            |    OLD    |    NEW    |
1460  * -----------+-----------+-----------+
1461  *    FWD     |     X     |    X+A    |
1462  * -----------+-----------+-----------+
1463  *    D_FWD   |     Y     |    Y-A    |
1464  * -----------+-----------+-----------+
1465  *    NONE    |           |     A     |
1466  * -----------+-----------+-----------+
1467  *
1468  * a) Received sources are NONE/NEW
1469  * b) All NONE will be deleted by amt_cleanup_srcs().
1470  * c) All OLD will be deleted by amt_cleanup_srcs().
1471  * d) After delete, NEW source will be switched to OLD.
1472  */
1473 static void amt_lookup_act_srcs(struct amt_tunnel_list *tunnel,
1474 				struct amt_group_node *gnode,
1475 				void *grec,
1476 				enum amt_ops ops,
1477 				enum amt_filter filter,
1478 				enum amt_act act,
1479 				bool v6)
1480 {
1481 	struct amt_dev *amt = tunnel->amt;
1482 	struct amt_source_node *snode;
1483 	struct igmpv3_grec *igmp_grec;
1484 #if IS_ENABLED(CONFIG_IPV6)
1485 	struct mld2_grec *mld_grec;
1486 #endif
1487 	union amt_addr src = {0,};
1488 	struct hlist_node *t;
1489 	u16 nsrcs;
1490 	int i, j;
1491 
1492 	if (!v6) {
1493 		igmp_grec = grec;
1494 		nsrcs = ntohs(igmp_grec->grec_nsrcs);
1495 	} else {
1496 #if IS_ENABLED(CONFIG_IPV6)
1497 		mld_grec = grec;
1498 		nsrcs = ntohs(mld_grec->grec_nsrcs);
1499 #else
1500 	return;
1501 #endif
1502 	}
1503 
1504 	memset(&src, 0, sizeof(union amt_addr));
1505 	switch (ops) {
1506 	case AMT_OPS_INT:
1507 		/* A*B */
1508 		for (i = 0; i < nsrcs; i++) {
1509 			if (!v6)
1510 				src.ip4 = igmp_grec->grec_src[i];
1511 #if IS_ENABLED(CONFIG_IPV6)
1512 			else
1513 				memcpy(&src.ip6, &mld_grec->grec_src[i],
1514 				       sizeof(struct in6_addr));
1515 #endif
1516 			snode = amt_lookup_src(tunnel, gnode, filter, &src);
1517 			if (!snode)
1518 				continue;
1519 			amt_act_src(tunnel, gnode, snode, act);
1520 		}
1521 		break;
1522 	case AMT_OPS_UNI:
1523 		/* A+B */
1524 		for (i = 0; i < amt->hash_buckets; i++) {
1525 			hlist_for_each_entry_safe(snode, t, &gnode->sources[i],
1526 						  node) {
1527 				if (amt_status_filter(snode, filter))
1528 					amt_act_src(tunnel, gnode, snode, act);
1529 			}
1530 		}
1531 		for (i = 0; i < nsrcs; i++) {
1532 			if (!v6)
1533 				src.ip4 = igmp_grec->grec_src[i];
1534 #if IS_ENABLED(CONFIG_IPV6)
1535 			else
1536 				memcpy(&src.ip6, &mld_grec->grec_src[i],
1537 				       sizeof(struct in6_addr));
1538 #endif
1539 			snode = amt_lookup_src(tunnel, gnode, filter, &src);
1540 			if (!snode)
1541 				continue;
1542 			amt_act_src(tunnel, gnode, snode, act);
1543 		}
1544 		break;
1545 	case AMT_OPS_SUB:
1546 		/* A-B */
1547 		for (i = 0; i < amt->hash_buckets; i++) {
1548 			hlist_for_each_entry_safe(snode, t, &gnode->sources[i],
1549 						  node) {
1550 				if (!amt_status_filter(snode, filter))
1551 					continue;
1552 				for (j = 0; j < nsrcs; j++) {
1553 					if (!v6)
1554 						src.ip4 = igmp_grec->grec_src[j];
1555 #if IS_ENABLED(CONFIG_IPV6)
1556 					else
1557 						memcpy(&src.ip6,
1558 						       &mld_grec->grec_src[j],
1559 						       sizeof(struct in6_addr));
1560 #endif
1561 					if (amt_addr_equal(&snode->source_addr,
1562 							   &src))
1563 						goto out_sub;
1564 				}
1565 				amt_act_src(tunnel, gnode, snode, act);
1566 				continue;
1567 out_sub:;
1568 			}
1569 		}
1570 		break;
1571 	case AMT_OPS_SUB_REV:
1572 		/* B-A */
1573 		for (i = 0; i < nsrcs; i++) {
1574 			if (!v6)
1575 				src.ip4 = igmp_grec->grec_src[i];
1576 #if IS_ENABLED(CONFIG_IPV6)
1577 			else
1578 				memcpy(&src.ip6, &mld_grec->grec_src[i],
1579 				       sizeof(struct in6_addr));
1580 #endif
1581 			snode = amt_lookup_src(tunnel, gnode, AMT_FILTER_ALL,
1582 					       &src);
1583 			if (!snode) {
1584 				snode = amt_lookup_src(tunnel, gnode,
1585 						       filter, &src);
1586 				if (snode)
1587 					amt_act_src(tunnel, gnode, snode, act);
1588 			}
1589 		}
1590 		break;
1591 	default:
1592 		netdev_dbg(amt->dev, "Invalid type\n");
1593 		return;
1594 	}
1595 }
1596 
1597 static void amt_mcast_is_in_handler(struct amt_dev *amt,
1598 				    struct amt_tunnel_list *tunnel,
1599 				    struct amt_group_node *gnode,
1600 				    void *grec, void *zero_grec, bool v6)
1601 {
1602 	if (gnode->filter_mode == MCAST_INCLUDE) {
1603 /* Router State   Report Rec'd New Router State        Actions
1604  * ------------   ------------ ----------------        -------
1605  * INCLUDE (A)    IS_IN (B)    INCLUDE (A+B)           (B)=GMI
1606  */
1607 		/* Update IS_IN (B) as FWD/NEW */
1608 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1609 				    AMT_FILTER_NONE_NEW,
1610 				    AMT_ACT_STATUS_FWD_NEW,
1611 				    v6);
1612 		/* Update INCLUDE (A) as NEW */
1613 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1614 				    AMT_FILTER_FWD,
1615 				    AMT_ACT_STATUS_FWD_NEW,
1616 				    v6);
1617 		/* (B)=GMI */
1618 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1619 				    AMT_FILTER_FWD_NEW,
1620 				    AMT_ACT_GMI,
1621 				    v6);
1622 	} else {
1623 /* State        Actions
1624  * ------------   ------------ ----------------        -------
1625  * EXCLUDE (X,Y)  IS_IN (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1626  */
1627 		/* Update (A) in (X, Y) as NONE/NEW */
1628 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1629 				    AMT_FILTER_BOTH,
1630 				    AMT_ACT_STATUS_NONE_NEW,
1631 				    v6);
1632 		/* Update FWD/OLD as FWD/NEW */
1633 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1634 				    AMT_FILTER_FWD,
1635 				    AMT_ACT_STATUS_FWD_NEW,
1636 				    v6);
1637 		/* Update IS_IN (A) as FWD/NEW */
1638 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1639 				    AMT_FILTER_NONE_NEW,
1640 				    AMT_ACT_STATUS_FWD_NEW,
1641 				    v6);
1642 		/* Update EXCLUDE (, Y-A) as D_FWD_NEW */
1643 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB,
1644 				    AMT_FILTER_D_FWD,
1645 				    AMT_ACT_STATUS_D_FWD_NEW,
1646 				    v6);
1647 	}
1648 }
1649 
1650 static void amt_mcast_is_ex_handler(struct amt_dev *amt,
1651 				    struct amt_tunnel_list *tunnel,
1652 				    struct amt_group_node *gnode,
1653 				    void *grec, void *zero_grec, bool v6)
1654 {
1655 	if (gnode->filter_mode == MCAST_INCLUDE) {
1656 /* Router State   Report Rec'd  New Router State         Actions
1657  * ------------   ------------  ----------------         -------
1658  * INCLUDE (A)    IS_EX (B)     EXCLUDE (A*B,B-A)        (B-A)=0
1659  *                                                       Delete (A-B)
1660  *                                                       Group Timer=GMI
1661  */
1662 		/* EXCLUDE(A*B, ) */
1663 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1664 				    AMT_FILTER_FWD,
1665 				    AMT_ACT_STATUS_FWD_NEW,
1666 				    v6);
1667 		/* EXCLUDE(, B-A) */
1668 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1669 				    AMT_FILTER_FWD,
1670 				    AMT_ACT_STATUS_D_FWD_NEW,
1671 				    v6);
1672 		/* (B-A)=0 */
1673 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1674 				    AMT_FILTER_D_FWD_NEW,
1675 				    AMT_ACT_GMI_ZERO,
1676 				    v6);
1677 		/* Group Timer=GMI */
1678 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1679 				      msecs_to_jiffies(amt_gmi(amt))))
1680 			dev_hold(amt->dev);
1681 		gnode->filter_mode = MCAST_EXCLUDE;
1682 		/* Delete (A-B) will be worked by amt_cleanup_srcs(). */
1683 	} else {
1684 /* Router State   Report Rec'd  New Router State	Actions
1685  * ------------   ------------  ----------------	-------
1686  * EXCLUDE (X,Y)  IS_EX (A)     EXCLUDE (A-Y,Y*A)	(A-X-Y)=GMI
1687  *							Delete (X-A)
1688  *							Delete (Y-A)
1689  *							Group Timer=GMI
1690  */
1691 		/* EXCLUDE (A-Y, ) */
1692 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1693 				    AMT_FILTER_D_FWD,
1694 				    AMT_ACT_STATUS_FWD_NEW,
1695 				    v6);
1696 		/* EXCLUDE (, Y*A ) */
1697 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1698 				    AMT_FILTER_D_FWD,
1699 				    AMT_ACT_STATUS_D_FWD_NEW,
1700 				    v6);
1701 		/* (A-X-Y)=GMI */
1702 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1703 				    AMT_FILTER_BOTH_NEW,
1704 				    AMT_ACT_GMI,
1705 				    v6);
1706 		/* Group Timer=GMI */
1707 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1708 				      msecs_to_jiffies(amt_gmi(amt))))
1709 			dev_hold(amt->dev);
1710 		/* Delete (X-A), (Y-A) will be worked by amt_cleanup_srcs(). */
1711 	}
1712 }
1713 
1714 static void amt_mcast_to_in_handler(struct amt_dev *amt,
1715 				    struct amt_tunnel_list *tunnel,
1716 				    struct amt_group_node *gnode,
1717 				    void *grec, void *zero_grec, bool v6)
1718 {
1719 	if (gnode->filter_mode == MCAST_INCLUDE) {
1720 /* Router State   Report Rec'd New Router State        Actions
1721  * ------------   ------------ ----------------        -------
1722  * INCLUDE (A)    TO_IN (B)    INCLUDE (A+B)           (B)=GMI
1723  *						       Send Q(G,A-B)
1724  */
1725 		/* Update TO_IN (B) sources as FWD/NEW */
1726 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1727 				    AMT_FILTER_NONE_NEW,
1728 				    AMT_ACT_STATUS_FWD_NEW,
1729 				    v6);
1730 		/* Update INCLUDE (A) sources as NEW */
1731 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1732 				    AMT_FILTER_FWD,
1733 				    AMT_ACT_STATUS_FWD_NEW,
1734 				    v6);
1735 		/* (B)=GMI */
1736 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1737 				    AMT_FILTER_FWD_NEW,
1738 				    AMT_ACT_GMI,
1739 				    v6);
1740 	} else {
1741 /* Router State   Report Rec'd New Router State        Actions
1742  * ------------   ------------ ----------------        -------
1743  * EXCLUDE (X,Y)  TO_IN (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1744  *						       Send Q(G,X-A)
1745  *						       Send Q(G)
1746  */
1747 		/* Update TO_IN (A) sources as FWD/NEW */
1748 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1749 				    AMT_FILTER_NONE_NEW,
1750 				    AMT_ACT_STATUS_FWD_NEW,
1751 				    v6);
1752 		/* Update EXCLUDE(X,) sources as FWD/NEW */
1753 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1754 				    AMT_FILTER_FWD,
1755 				    AMT_ACT_STATUS_FWD_NEW,
1756 				    v6);
1757 		/* EXCLUDE (, Y-A)
1758 		 * (A) are already switched to FWD_NEW.
1759 		 * So, D_FWD/OLD -> D_FWD/NEW is okay.
1760 		 */
1761 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1762 				    AMT_FILTER_D_FWD,
1763 				    AMT_ACT_STATUS_D_FWD_NEW,
1764 				    v6);
1765 		/* (A)=GMI
1766 		 * Only FWD_NEW will have (A) sources.
1767 		 */
1768 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1769 				    AMT_FILTER_FWD_NEW,
1770 				    AMT_ACT_GMI,
1771 				    v6);
1772 	}
1773 }
1774 
1775 static void amt_mcast_to_ex_handler(struct amt_dev *amt,
1776 				    struct amt_tunnel_list *tunnel,
1777 				    struct amt_group_node *gnode,
1778 				    void *grec, void *zero_grec, bool v6)
1779 {
1780 	if (gnode->filter_mode == MCAST_INCLUDE) {
1781 /* Router State   Report Rec'd New Router State        Actions
1782  * ------------   ------------ ----------------        -------
1783  * INCLUDE (A)    TO_EX (B)    EXCLUDE (A*B,B-A)       (B-A)=0
1784  *						       Delete (A-B)
1785  *						       Send Q(G,A*B)
1786  *						       Group Timer=GMI
1787  */
1788 		/* EXCLUDE (A*B, ) */
1789 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1790 				    AMT_FILTER_FWD,
1791 				    AMT_ACT_STATUS_FWD_NEW,
1792 				    v6);
1793 		/* EXCLUDE (, B-A) */
1794 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1795 				    AMT_FILTER_FWD,
1796 				    AMT_ACT_STATUS_D_FWD_NEW,
1797 				    v6);
1798 		/* (B-A)=0 */
1799 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1800 				    AMT_FILTER_D_FWD_NEW,
1801 				    AMT_ACT_GMI_ZERO,
1802 				    v6);
1803 		/* Group Timer=GMI */
1804 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1805 				      msecs_to_jiffies(amt_gmi(amt))))
1806 			dev_hold(amt->dev);
1807 		gnode->filter_mode = MCAST_EXCLUDE;
1808 		/* Delete (A-B) will be worked by amt_cleanup_srcs(). */
1809 	} else {
1810 /* Router State   Report Rec'd New Router State        Actions
1811  * ------------   ------------ ----------------        -------
1812  * EXCLUDE (X,Y)  TO_EX (A)    EXCLUDE (A-Y,Y*A)       (A-X-Y)=Group Timer
1813  *						       Delete (X-A)
1814  *						       Delete (Y-A)
1815  *						       Send Q(G,A-Y)
1816  *						       Group Timer=GMI
1817  */
1818 		/* Update (A-X-Y) as NONE/OLD */
1819 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1820 				    AMT_FILTER_BOTH,
1821 				    AMT_ACT_GT,
1822 				    v6);
1823 		/* EXCLUDE (A-Y, ) */
1824 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1825 				    AMT_FILTER_D_FWD,
1826 				    AMT_ACT_STATUS_FWD_NEW,
1827 				    v6);
1828 		/* EXCLUDE (, Y*A) */
1829 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1830 				    AMT_FILTER_D_FWD,
1831 				    AMT_ACT_STATUS_D_FWD_NEW,
1832 				    v6);
1833 		/* Group Timer=GMI */
1834 		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1835 				      msecs_to_jiffies(amt_gmi(amt))))
1836 			dev_hold(amt->dev);
1837 		/* Delete (X-A), (Y-A) will be worked by amt_cleanup_srcs(). */
1838 	}
1839 }
1840 
1841 static void amt_mcast_allow_handler(struct amt_dev *amt,
1842 				    struct amt_tunnel_list *tunnel,
1843 				    struct amt_group_node *gnode,
1844 				    void *grec, void *zero_grec, bool v6)
1845 {
1846 	if (gnode->filter_mode == MCAST_INCLUDE) {
1847 /* Router State   Report Rec'd New Router State        Actions
1848  * ------------   ------------ ----------------        -------
1849  * INCLUDE (A)    ALLOW (B)    INCLUDE (A+B)	       (B)=GMI
1850  */
1851 		/* INCLUDE (A+B) */
1852 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1853 				    AMT_FILTER_FWD,
1854 				    AMT_ACT_STATUS_FWD_NEW,
1855 				    v6);
1856 		/* (B)=GMI */
1857 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1858 				    AMT_FILTER_FWD_NEW,
1859 				    AMT_ACT_GMI,
1860 				    v6);
1861 	} else {
1862 /* Router State   Report Rec'd New Router State        Actions
1863  * ------------   ------------ ----------------        -------
1864  * EXCLUDE (X,Y)  ALLOW (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1865  */
1866 		/* EXCLUDE (X+A, ) */
1867 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1868 				    AMT_FILTER_FWD,
1869 				    AMT_ACT_STATUS_FWD_NEW,
1870 				    v6);
1871 		/* EXCLUDE (, Y-A) */
1872 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB,
1873 				    AMT_FILTER_D_FWD,
1874 				    AMT_ACT_STATUS_D_FWD_NEW,
1875 				    v6);
1876 		/* (A)=GMI
1877 		 * All (A) source are now FWD/NEW status.
1878 		 */
1879 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1880 				    AMT_FILTER_FWD_NEW,
1881 				    AMT_ACT_GMI,
1882 				    v6);
1883 	}
1884 }
1885 
1886 static void amt_mcast_block_handler(struct amt_dev *amt,
1887 				    struct amt_tunnel_list *tunnel,
1888 				    struct amt_group_node *gnode,
1889 				    void *grec, void *zero_grec, bool v6)
1890 {
1891 	if (gnode->filter_mode == MCAST_INCLUDE) {
1892 /* Router State   Report Rec'd New Router State        Actions
1893  * ------------   ------------ ----------------        -------
1894  * INCLUDE (A)    BLOCK (B)    INCLUDE (A)             Send Q(G,A*B)
1895  */
1896 		/* INCLUDE (A) */
1897 		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1898 				    AMT_FILTER_FWD,
1899 				    AMT_ACT_STATUS_FWD_NEW,
1900 				    v6);
1901 	} else {
1902 /* Router State   Report Rec'd New Router State        Actions
1903  * ------------   ------------ ----------------        -------
1904  * EXCLUDE (X,Y)  BLOCK (A)    EXCLUDE (X+(A-Y),Y)     (A-X-Y)=Group Timer
1905  *						       Send Q(G,A-Y)
1906  */
1907 		/* (A-X-Y)=Group Timer */
1908 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1909 				    AMT_FILTER_BOTH,
1910 				    AMT_ACT_GT,
1911 				    v6);
1912 		/* EXCLUDE (X, ) */
1913 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1914 				    AMT_FILTER_FWD,
1915 				    AMT_ACT_STATUS_FWD_NEW,
1916 				    v6);
1917 		/* EXCLUDE (X+(A-Y) */
1918 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1919 				    AMT_FILTER_D_FWD,
1920 				    AMT_ACT_STATUS_FWD_NEW,
1921 				    v6);
1922 		/* EXCLUDE (, Y) */
1923 		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1924 				    AMT_FILTER_D_FWD,
1925 				    AMT_ACT_STATUS_D_FWD_NEW,
1926 				    v6);
1927 	}
1928 }
1929 
1930 /* RFC 3376
1931  * 7.3.2. In the Presence of Older Version Group Members
1932  *
1933  * When Group Compatibility Mode is IGMPv2, a router internally
1934  * translates the following IGMPv2 messages for that group to their
1935  * IGMPv3 equivalents:
1936  *
1937  * IGMPv2 Message                IGMPv3 Equivalent
1938  * --------------                -----------------
1939  * Report                        IS_EX( {} )
1940  * Leave                         TO_IN( {} )
1941  */
1942 static void amt_igmpv2_report_handler(struct amt_dev *amt, struct sk_buff *skb,
1943 				      struct amt_tunnel_list *tunnel)
1944 {
1945 	struct igmphdr *ih = igmp_hdr(skb);
1946 	struct iphdr *iph = ip_hdr(skb);
1947 	struct amt_group_node *gnode;
1948 	union amt_addr group, host;
1949 
1950 	memset(&group, 0, sizeof(union amt_addr));
1951 	group.ip4 = ih->group;
1952 	memset(&host, 0, sizeof(union amt_addr));
1953 	host.ip4 = iph->saddr;
1954 
1955 	gnode = amt_lookup_group(tunnel, &group, &host, false);
1956 	if (!gnode) {
1957 		gnode = amt_add_group(amt, tunnel, &group, &host, false);
1958 		if (!IS_ERR(gnode)) {
1959 			gnode->filter_mode = MCAST_EXCLUDE;
1960 			if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1961 					      msecs_to_jiffies(amt_gmi(amt))))
1962 				dev_hold(amt->dev);
1963 		}
1964 	}
1965 }
1966 
1967 /* RFC 3376
1968  * 7.3.2. In the Presence of Older Version Group Members
1969  *
1970  * When Group Compatibility Mode is IGMPv2, a router internally
1971  * translates the following IGMPv2 messages for that group to their
1972  * IGMPv3 equivalents:
1973  *
1974  * IGMPv2 Message                IGMPv3 Equivalent
1975  * --------------                -----------------
1976  * Report                        IS_EX( {} )
1977  * Leave                         TO_IN( {} )
1978  */
1979 static void amt_igmpv2_leave_handler(struct amt_dev *amt, struct sk_buff *skb,
1980 				     struct amt_tunnel_list *tunnel)
1981 {
1982 	struct igmphdr *ih = igmp_hdr(skb);
1983 	struct iphdr *iph = ip_hdr(skb);
1984 	struct amt_group_node *gnode;
1985 	union amt_addr group, host;
1986 
1987 	memset(&group, 0, sizeof(union amt_addr));
1988 	group.ip4 = ih->group;
1989 	memset(&host, 0, sizeof(union amt_addr));
1990 	host.ip4 = iph->saddr;
1991 
1992 	gnode = amt_lookup_group(tunnel, &group, &host, false);
1993 	if (gnode)
1994 		amt_del_group(amt, gnode);
1995 }
1996 
1997 static void amt_igmpv3_report_handler(struct amt_dev *amt, struct sk_buff *skb,
1998 				      struct amt_tunnel_list *tunnel)
1999 {
2000 	struct igmpv3_report *ihrv3 = igmpv3_report_hdr(skb);
2001 	int len = skb_transport_offset(skb) + sizeof(*ihrv3);
2002 	void *zero_grec = (void *)&igmpv3_zero_grec;
2003 	struct iphdr *iph = ip_hdr(skb);
2004 	struct amt_group_node *gnode;
2005 	union amt_addr group, host;
2006 	struct igmpv3_grec *grec;
2007 	u16 nsrcs;
2008 	int i;
2009 
2010 	for (i = 0; i < ntohs(ihrv3->ngrec); i++) {
2011 		len += sizeof(*grec);
2012 		if (!ip_mc_may_pull(skb, len))
2013 			break;
2014 
2015 		grec = (void *)(skb->data + len - sizeof(*grec));
2016 		nsrcs = ntohs(grec->grec_nsrcs);
2017 
2018 		len += nsrcs * sizeof(__be32);
2019 		if (!ip_mc_may_pull(skb, len))
2020 			break;
2021 
2022 		memset(&group, 0, sizeof(union amt_addr));
2023 		group.ip4 = grec->grec_mca;
2024 		memset(&host, 0, sizeof(union amt_addr));
2025 		host.ip4 = iph->saddr;
2026 		gnode = amt_lookup_group(tunnel, &group, &host, false);
2027 		if (!gnode) {
2028 			gnode = amt_add_group(amt, tunnel, &group, &host,
2029 					      false);
2030 			if (IS_ERR(gnode))
2031 				continue;
2032 		}
2033 
2034 		amt_add_srcs(amt, tunnel, gnode, grec, false);
2035 		switch (grec->grec_type) {
2036 		case IGMPV3_MODE_IS_INCLUDE:
2037 			amt_mcast_is_in_handler(amt, tunnel, gnode, grec,
2038 						zero_grec, false);
2039 			break;
2040 		case IGMPV3_MODE_IS_EXCLUDE:
2041 			amt_mcast_is_ex_handler(amt, tunnel, gnode, grec,
2042 						zero_grec, false);
2043 			break;
2044 		case IGMPV3_CHANGE_TO_INCLUDE:
2045 			amt_mcast_to_in_handler(amt, tunnel, gnode, grec,
2046 						zero_grec, false);
2047 			break;
2048 		case IGMPV3_CHANGE_TO_EXCLUDE:
2049 			amt_mcast_to_ex_handler(amt, tunnel, gnode, grec,
2050 						zero_grec, false);
2051 			break;
2052 		case IGMPV3_ALLOW_NEW_SOURCES:
2053 			amt_mcast_allow_handler(amt, tunnel, gnode, grec,
2054 						zero_grec, false);
2055 			break;
2056 		case IGMPV3_BLOCK_OLD_SOURCES:
2057 			amt_mcast_block_handler(amt, tunnel, gnode, grec,
2058 						zero_grec, false);
2059 			break;
2060 		default:
2061 			break;
2062 		}
2063 		amt_cleanup_srcs(amt, tunnel, gnode);
2064 	}
2065 }
2066 
2067 /* caller held tunnel->lock */
2068 static void amt_igmp_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2069 				    struct amt_tunnel_list *tunnel)
2070 {
2071 	struct igmphdr *ih = igmp_hdr(skb);
2072 
2073 	switch (ih->type) {
2074 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
2075 		amt_igmpv3_report_handler(amt, skb, tunnel);
2076 		break;
2077 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
2078 		amt_igmpv2_report_handler(amt, skb, tunnel);
2079 		break;
2080 	case IGMP_HOST_LEAVE_MESSAGE:
2081 		amt_igmpv2_leave_handler(amt, skb, tunnel);
2082 		break;
2083 	default:
2084 		break;
2085 	}
2086 }
2087 
2088 #if IS_ENABLED(CONFIG_IPV6)
2089 /* RFC 3810
2090  * 8.3.2. In the Presence of MLDv1 Multicast Address Listeners
2091  *
2092  * When Multicast Address Compatibility Mode is MLDv2, a router acts
2093  * using the MLDv2 protocol for that multicast address.  When Multicast
2094  * Address Compatibility Mode is MLDv1, a router internally translates
2095  * the following MLDv1 messages for that multicast address to their
2096  * MLDv2 equivalents:
2097  *
2098  * MLDv1 Message                 MLDv2 Equivalent
2099  * --------------                -----------------
2100  * Report                        IS_EX( {} )
2101  * Done                          TO_IN( {} )
2102  */
2103 static void amt_mldv1_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2104 				     struct amt_tunnel_list *tunnel)
2105 {
2106 	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2107 	struct ipv6hdr *ip6h = ipv6_hdr(skb);
2108 	struct amt_group_node *gnode;
2109 	union amt_addr group, host;
2110 
2111 	memcpy(&group.ip6, &mld->mld_mca, sizeof(struct in6_addr));
2112 	memcpy(&host.ip6, &ip6h->saddr, sizeof(struct in6_addr));
2113 
2114 	gnode = amt_lookup_group(tunnel, &group, &host, true);
2115 	if (!gnode) {
2116 		gnode = amt_add_group(amt, tunnel, &group, &host, true);
2117 		if (!IS_ERR(gnode)) {
2118 			gnode->filter_mode = MCAST_EXCLUDE;
2119 			if (!mod_delayed_work(amt_wq, &gnode->group_timer,
2120 					      msecs_to_jiffies(amt_gmi(amt))))
2121 				dev_hold(amt->dev);
2122 		}
2123 	}
2124 }
2125 
2126 /* RFC 3810
2127  * 8.3.2. In the Presence of MLDv1 Multicast Address Listeners
2128  *
2129  * When Multicast Address Compatibility Mode is MLDv2, a router acts
2130  * using the MLDv2 protocol for that multicast address.  When Multicast
2131  * Address Compatibility Mode is MLDv1, a router internally translates
2132  * the following MLDv1 messages for that multicast address to their
2133  * MLDv2 equivalents:
2134  *
2135  * MLDv1 Message                 MLDv2 Equivalent
2136  * --------------                -----------------
2137  * Report                        IS_EX( {} )
2138  * Done                          TO_IN( {} )
2139  */
2140 static void amt_mldv1_leave_handler(struct amt_dev *amt, struct sk_buff *skb,
2141 				    struct amt_tunnel_list *tunnel)
2142 {
2143 	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2144 	struct iphdr *iph = ip_hdr(skb);
2145 	struct amt_group_node *gnode;
2146 	union amt_addr group, host;
2147 
2148 	memcpy(&group.ip6, &mld->mld_mca, sizeof(struct in6_addr));
2149 	memset(&host, 0, sizeof(union amt_addr));
2150 	host.ip4 = iph->saddr;
2151 
2152 	gnode = amt_lookup_group(tunnel, &group, &host, true);
2153 	if (gnode) {
2154 		amt_del_group(amt, gnode);
2155 		return;
2156 	}
2157 }
2158 
2159 static void amt_mldv2_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2160 				     struct amt_tunnel_list *tunnel)
2161 {
2162 	struct mld2_report *mld2r = (struct mld2_report *)icmp6_hdr(skb);
2163 	int len = skb_transport_offset(skb) + sizeof(*mld2r);
2164 	void *zero_grec = (void *)&mldv2_zero_grec;
2165 	struct ipv6hdr *ip6h = ipv6_hdr(skb);
2166 	struct amt_group_node *gnode;
2167 	union amt_addr group, host;
2168 	struct mld2_grec *grec;
2169 	u16 nsrcs;
2170 	int i;
2171 
2172 	for (i = 0; i < ntohs(mld2r->mld2r_ngrec); i++) {
2173 		len += sizeof(*grec);
2174 		if (!ipv6_mc_may_pull(skb, len))
2175 			break;
2176 
2177 		grec = (void *)(skb->data + len - sizeof(*grec));
2178 		nsrcs = ntohs(grec->grec_nsrcs);
2179 
2180 		len += nsrcs * sizeof(struct in6_addr);
2181 		if (!ipv6_mc_may_pull(skb, len))
2182 			break;
2183 
2184 		memset(&group, 0, sizeof(union amt_addr));
2185 		group.ip6 = grec->grec_mca;
2186 		memset(&host, 0, sizeof(union amt_addr));
2187 		host.ip6 = ip6h->saddr;
2188 		gnode = amt_lookup_group(tunnel, &group, &host, true);
2189 		if (!gnode) {
2190 			gnode = amt_add_group(amt, tunnel, &group, &host,
2191 					      ETH_P_IPV6);
2192 			if (IS_ERR(gnode))
2193 				continue;
2194 		}
2195 
2196 		amt_add_srcs(amt, tunnel, gnode, grec, true);
2197 		switch (grec->grec_type) {
2198 		case MLD2_MODE_IS_INCLUDE:
2199 			amt_mcast_is_in_handler(amt, tunnel, gnode, grec,
2200 						zero_grec, true);
2201 			break;
2202 		case MLD2_MODE_IS_EXCLUDE:
2203 			amt_mcast_is_ex_handler(amt, tunnel, gnode, grec,
2204 						zero_grec, true);
2205 			break;
2206 		case MLD2_CHANGE_TO_INCLUDE:
2207 			amt_mcast_to_in_handler(amt, tunnel, gnode, grec,
2208 						zero_grec, true);
2209 			break;
2210 		case MLD2_CHANGE_TO_EXCLUDE:
2211 			amt_mcast_to_ex_handler(amt, tunnel, gnode, grec,
2212 						zero_grec, true);
2213 			break;
2214 		case MLD2_ALLOW_NEW_SOURCES:
2215 			amt_mcast_allow_handler(amt, tunnel, gnode, grec,
2216 						zero_grec, true);
2217 			break;
2218 		case MLD2_BLOCK_OLD_SOURCES:
2219 			amt_mcast_block_handler(amt, tunnel, gnode, grec,
2220 						zero_grec, true);
2221 			break;
2222 		default:
2223 			break;
2224 		}
2225 		amt_cleanup_srcs(amt, tunnel, gnode);
2226 	}
2227 }
2228 
2229 /* caller held tunnel->lock */
2230 static void amt_mld_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2231 				   struct amt_tunnel_list *tunnel)
2232 {
2233 	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2234 
2235 	switch (mld->mld_type) {
2236 	case ICMPV6_MGM_REPORT:
2237 		amt_mldv1_report_handler(amt, skb, tunnel);
2238 		break;
2239 	case ICMPV6_MLD2_REPORT:
2240 		amt_mldv2_report_handler(amt, skb, tunnel);
2241 		break;
2242 	case ICMPV6_MGM_REDUCTION:
2243 		amt_mldv1_leave_handler(amt, skb, tunnel);
2244 		break;
2245 	default:
2246 		break;
2247 	}
2248 }
2249 #endif
2250 
2251 static bool amt_advertisement_handler(struct amt_dev *amt, struct sk_buff *skb)
2252 {
2253 	struct amt_header_advertisement *amta;
2254 	int hdr_size;
2255 
2256 	hdr_size = sizeof(*amta) + sizeof(struct udphdr);
2257 	if (!pskb_may_pull(skb, hdr_size))
2258 		return true;
2259 
2260 	amta = (struct amt_header_advertisement *)(udp_hdr(skb) + 1);
2261 	if (!amta->ip4)
2262 		return true;
2263 
2264 	if (amta->reserved || amta->version)
2265 		return true;
2266 
2267 	if (ipv4_is_loopback(amta->ip4) || ipv4_is_multicast(amta->ip4) ||
2268 	    ipv4_is_zeronet(amta->ip4))
2269 		return true;
2270 
2271 	if (amt->status != AMT_STATUS_SENT_DISCOVERY ||
2272 	    amt->nonce != amta->nonce)
2273 		return true;
2274 
2275 	amt->remote_ip = amta->ip4;
2276 	netdev_dbg(amt->dev, "advertised remote ip = %pI4\n", &amt->remote_ip);
2277 	mod_delayed_work(amt_wq, &amt->req_wq, 0);
2278 
2279 	amt_update_gw_status(amt, AMT_STATUS_RECEIVED_ADVERTISEMENT, true);
2280 	return false;
2281 }
2282 
2283 static bool amt_multicast_data_handler(struct amt_dev *amt, struct sk_buff *skb)
2284 {
2285 	struct amt_header_mcast_data *amtmd;
2286 	int hdr_size, len, err;
2287 	struct ethhdr *eth;
2288 	struct iphdr *iph;
2289 
2290 	if (READ_ONCE(amt->status) != AMT_STATUS_SENT_UPDATE)
2291 		return true;
2292 
2293 	hdr_size = sizeof(*amtmd) + sizeof(struct udphdr);
2294 	if (!pskb_may_pull(skb, hdr_size))
2295 		return true;
2296 
2297 	amtmd = (struct amt_header_mcast_data *)(udp_hdr(skb) + 1);
2298 	if (amtmd->reserved || amtmd->version)
2299 		return true;
2300 
2301 	if (iptunnel_pull_header(skb, hdr_size, htons(ETH_P_IP), false))
2302 		return true;
2303 
2304 	skb_reset_network_header(skb);
2305 	skb_push(skb, sizeof(*eth));
2306 	skb_reset_mac_header(skb);
2307 	skb_pull(skb, sizeof(*eth));
2308 	eth = eth_hdr(skb);
2309 
2310 	if (!pskb_may_pull(skb, sizeof(*iph)))
2311 		return true;
2312 	iph = ip_hdr(skb);
2313 
2314 	if (iph->version == 4) {
2315 		if (!ipv4_is_multicast(iph->daddr))
2316 			return true;
2317 		skb->protocol = htons(ETH_P_IP);
2318 		eth->h_proto = htons(ETH_P_IP);
2319 		ip_eth_mc_map(iph->daddr, eth->h_dest);
2320 #if IS_ENABLED(CONFIG_IPV6)
2321 	} else if (iph->version == 6) {
2322 		struct ipv6hdr *ip6h;
2323 
2324 		if (!pskb_may_pull(skb, sizeof(*ip6h)))
2325 			return true;
2326 
2327 		ip6h = ipv6_hdr(skb);
2328 		if (!ipv6_addr_is_multicast(&ip6h->daddr))
2329 			return true;
2330 		skb->protocol = htons(ETH_P_IPV6);
2331 		eth->h_proto = htons(ETH_P_IPV6);
2332 		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2333 #endif
2334 	} else {
2335 		return true;
2336 	}
2337 
2338 	skb->pkt_type = PACKET_MULTICAST;
2339 	skb->ip_summed = CHECKSUM_NONE;
2340 	len = skb->len;
2341 	err = gro_cells_receive(&amt->gro_cells, skb);
2342 	if (likely(err == NET_RX_SUCCESS))
2343 		dev_sw_netstats_rx_add(amt->dev, len);
2344 	else
2345 		amt->dev->stats.rx_dropped++;
2346 
2347 	return false;
2348 }
2349 
2350 static bool amt_membership_query_handler(struct amt_dev *amt,
2351 					 struct sk_buff *skb)
2352 {
2353 	struct amt_header_membership_query *amtmq;
2354 	struct igmpv3_query *ihv3;
2355 	struct ethhdr *eth, *oeth;
2356 	struct iphdr *iph;
2357 	int hdr_size, len;
2358 
2359 	hdr_size = sizeof(*amtmq) + sizeof(struct udphdr);
2360 	if (!pskb_may_pull(skb, hdr_size))
2361 		return true;
2362 
2363 	amtmq = (struct amt_header_membership_query *)(udp_hdr(skb) + 1);
2364 	if (amtmq->reserved || amtmq->version)
2365 		return true;
2366 
2367 	if (amtmq->nonce != amt->nonce)
2368 		return true;
2369 
2370 	hdr_size -= sizeof(*eth);
2371 	if (iptunnel_pull_header(skb, hdr_size, htons(ETH_P_TEB), false))
2372 		return true;
2373 
2374 	oeth = eth_hdr(skb);
2375 	skb_reset_mac_header(skb);
2376 	skb_pull(skb, sizeof(*eth));
2377 	skb_reset_network_header(skb);
2378 	eth = eth_hdr(skb);
2379 	if (!pskb_may_pull(skb, sizeof(*iph)))
2380 		return true;
2381 
2382 	iph = ip_hdr(skb);
2383 	if (iph->version == 4) {
2384 		if (READ_ONCE(amt->ready4))
2385 			return true;
2386 
2387 		if (!pskb_may_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS +
2388 				   sizeof(*ihv3)))
2389 			return true;
2390 
2391 		if (!ipv4_is_multicast(iph->daddr))
2392 			return true;
2393 
2394 		ihv3 = skb_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
2395 		skb_reset_transport_header(skb);
2396 		skb_push(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
2397 		WRITE_ONCE(amt->ready4, true);
2398 		amt->mac = amtmq->response_mac;
2399 		amt->req_cnt = 0;
2400 		amt->qi = ihv3->qqic;
2401 		skb->protocol = htons(ETH_P_IP);
2402 		eth->h_proto = htons(ETH_P_IP);
2403 		ip_eth_mc_map(iph->daddr, eth->h_dest);
2404 #if IS_ENABLED(CONFIG_IPV6)
2405 	} else if (iph->version == 6) {
2406 		struct mld2_query *mld2q;
2407 		struct ipv6hdr *ip6h;
2408 
2409 		if (READ_ONCE(amt->ready6))
2410 			return true;
2411 
2412 		if (!pskb_may_pull(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS +
2413 				   sizeof(*mld2q)))
2414 			return true;
2415 
2416 		ip6h = ipv6_hdr(skb);
2417 		if (!ipv6_addr_is_multicast(&ip6h->daddr))
2418 			return true;
2419 
2420 		mld2q = skb_pull(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS);
2421 		skb_reset_transport_header(skb);
2422 		skb_push(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS);
2423 		WRITE_ONCE(amt->ready6, true);
2424 		amt->mac = amtmq->response_mac;
2425 		amt->req_cnt = 0;
2426 		amt->qi = mld2q->mld2q_qqic;
2427 		skb->protocol = htons(ETH_P_IPV6);
2428 		eth->h_proto = htons(ETH_P_IPV6);
2429 		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2430 #endif
2431 	} else {
2432 		return true;
2433 	}
2434 
2435 	ether_addr_copy(eth->h_source, oeth->h_source);
2436 	skb->pkt_type = PACKET_MULTICAST;
2437 	skb->ip_summed = CHECKSUM_NONE;
2438 	len = skb->len;
2439 	local_bh_disable();
2440 	if (__netif_rx(skb) == NET_RX_SUCCESS) {
2441 		amt_update_gw_status(amt, AMT_STATUS_RECEIVED_QUERY, true);
2442 		dev_sw_netstats_rx_add(amt->dev, len);
2443 	} else {
2444 		amt->dev->stats.rx_dropped++;
2445 	}
2446 	local_bh_enable();
2447 
2448 	return false;
2449 }
2450 
2451 static bool amt_update_handler(struct amt_dev *amt, struct sk_buff *skb)
2452 {
2453 	struct amt_header_membership_update *amtmu;
2454 	struct amt_tunnel_list *tunnel;
2455 	struct ethhdr *eth;
2456 	struct iphdr *iph;
2457 	int len, hdr_size;
2458 
2459 	iph = ip_hdr(skb);
2460 
2461 	hdr_size = sizeof(*amtmu) + sizeof(struct udphdr);
2462 	if (!pskb_may_pull(skb, hdr_size))
2463 		return true;
2464 
2465 	amtmu = (struct amt_header_membership_update *)(udp_hdr(skb) + 1);
2466 	if (amtmu->reserved || amtmu->version)
2467 		return true;
2468 
2469 	if (iptunnel_pull_header(skb, hdr_size, skb->protocol, false))
2470 		return true;
2471 
2472 	skb_reset_network_header(skb);
2473 
2474 	list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list) {
2475 		if (tunnel->ip4 == iph->saddr) {
2476 			if ((amtmu->nonce == tunnel->nonce &&
2477 			     amtmu->response_mac == tunnel->mac)) {
2478 				mod_delayed_work(amt_wq, &tunnel->gc_wq,
2479 						 msecs_to_jiffies(amt_gmi(amt))
2480 								  * 3);
2481 				goto report;
2482 			} else {
2483 				netdev_dbg(amt->dev, "Invalid MAC\n");
2484 				return true;
2485 			}
2486 		}
2487 	}
2488 
2489 	return true;
2490 
2491 report:
2492 	if (!pskb_may_pull(skb, sizeof(*iph)))
2493 		return true;
2494 
2495 	iph = ip_hdr(skb);
2496 	if (iph->version == 4) {
2497 		if (ip_mc_check_igmp(skb)) {
2498 			netdev_dbg(amt->dev, "Invalid IGMP\n");
2499 			return true;
2500 		}
2501 
2502 		spin_lock_bh(&tunnel->lock);
2503 		amt_igmp_report_handler(amt, skb, tunnel);
2504 		spin_unlock_bh(&tunnel->lock);
2505 
2506 		skb_push(skb, sizeof(struct ethhdr));
2507 		skb_reset_mac_header(skb);
2508 		eth = eth_hdr(skb);
2509 		skb->protocol = htons(ETH_P_IP);
2510 		eth->h_proto = htons(ETH_P_IP);
2511 		ip_eth_mc_map(iph->daddr, eth->h_dest);
2512 #if IS_ENABLED(CONFIG_IPV6)
2513 	} else if (iph->version == 6) {
2514 		struct ipv6hdr *ip6h = ipv6_hdr(skb);
2515 
2516 		if (ipv6_mc_check_mld(skb)) {
2517 			netdev_dbg(amt->dev, "Invalid MLD\n");
2518 			return true;
2519 		}
2520 
2521 		spin_lock_bh(&tunnel->lock);
2522 		amt_mld_report_handler(amt, skb, tunnel);
2523 		spin_unlock_bh(&tunnel->lock);
2524 
2525 		skb_push(skb, sizeof(struct ethhdr));
2526 		skb_reset_mac_header(skb);
2527 		eth = eth_hdr(skb);
2528 		skb->protocol = htons(ETH_P_IPV6);
2529 		eth->h_proto = htons(ETH_P_IPV6);
2530 		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2531 #endif
2532 	} else {
2533 		netdev_dbg(amt->dev, "Unsupported Protocol\n");
2534 		return true;
2535 	}
2536 
2537 	skb_pull(skb, sizeof(struct ethhdr));
2538 	skb->pkt_type = PACKET_MULTICAST;
2539 	skb->ip_summed = CHECKSUM_NONE;
2540 	len = skb->len;
2541 	if (__netif_rx(skb) == NET_RX_SUCCESS) {
2542 		amt_update_relay_status(tunnel, AMT_STATUS_RECEIVED_UPDATE,
2543 					true);
2544 		dev_sw_netstats_rx_add(amt->dev, len);
2545 	} else {
2546 		amt->dev->stats.rx_dropped++;
2547 	}
2548 
2549 	return false;
2550 }
2551 
2552 static void amt_send_advertisement(struct amt_dev *amt, __be32 nonce,
2553 				   __be32 daddr, __be16 dport)
2554 {
2555 	struct amt_header_advertisement *amta;
2556 	int hlen, tlen, offset;
2557 	struct socket *sock;
2558 	struct udphdr *udph;
2559 	struct sk_buff *skb;
2560 	struct iphdr *iph;
2561 	struct rtable *rt;
2562 	struct flowi4 fl4;
2563 	u32 len;
2564 	int err;
2565 
2566 	rcu_read_lock();
2567 	sock = rcu_dereference(amt->sock);
2568 	if (!sock)
2569 		goto out;
2570 
2571 	if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
2572 		goto out;
2573 
2574 	rt = ip_route_output_ports(amt->net, &fl4, sock->sk,
2575 				   daddr, amt->local_ip,
2576 				   dport, amt->relay_port,
2577 				   IPPROTO_UDP, 0,
2578 				   amt->stream_dev->ifindex);
2579 	if (IS_ERR(rt)) {
2580 		amt->dev->stats.tx_errors++;
2581 		goto out;
2582 	}
2583 
2584 	hlen = LL_RESERVED_SPACE(amt->dev);
2585 	tlen = amt->dev->needed_tailroom;
2586 	len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amta);
2587 	skb = netdev_alloc_skb_ip_align(amt->dev, len);
2588 	if (!skb) {
2589 		ip_rt_put(rt);
2590 		amt->dev->stats.tx_errors++;
2591 		goto out;
2592 	}
2593 
2594 	skb->priority = TC_PRIO_CONTROL;
2595 	skb_dst_set(skb, &rt->dst);
2596 
2597 	len = sizeof(*iph) + sizeof(*udph) + sizeof(*amta);
2598 	skb_reset_network_header(skb);
2599 	skb_put(skb, len);
2600 	amta = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
2601 	amta->version	= 0;
2602 	amta->type	= AMT_MSG_ADVERTISEMENT;
2603 	amta->reserved	= 0;
2604 	amta->nonce	= nonce;
2605 	amta->ip4	= amt->local_ip;
2606 	skb_push(skb, sizeof(*udph));
2607 	skb_reset_transport_header(skb);
2608 	udph		= udp_hdr(skb);
2609 	udph->source	= amt->relay_port;
2610 	udph->dest	= dport;
2611 	udph->len	= htons(sizeof(*amta) + sizeof(*udph));
2612 	udph->check	= 0;
2613 	offset = skb_transport_offset(skb);
2614 	skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
2615 	udph->check = csum_tcpudp_magic(amt->local_ip, daddr,
2616 					sizeof(*udph) + sizeof(*amta),
2617 					IPPROTO_UDP, skb->csum);
2618 
2619 	skb_push(skb, sizeof(*iph));
2620 	iph		= ip_hdr(skb);
2621 	iph->version	= 4;
2622 	iph->ihl	= (sizeof(struct iphdr)) >> 2;
2623 	iph->tos	= AMT_TOS;
2624 	iph->frag_off	= 0;
2625 	iph->ttl	= ip4_dst_hoplimit(&rt->dst);
2626 	iph->daddr	= daddr;
2627 	iph->saddr	= amt->local_ip;
2628 	iph->protocol	= IPPROTO_UDP;
2629 	iph->tot_len	= htons(len);
2630 
2631 	skb->ip_summed = CHECKSUM_NONE;
2632 	ip_select_ident(amt->net, skb, NULL);
2633 	ip_send_check(iph);
2634 	err = ip_local_out(amt->net, sock->sk, skb);
2635 	if (unlikely(net_xmit_eval(err)))
2636 		amt->dev->stats.tx_errors++;
2637 
2638 out:
2639 	rcu_read_unlock();
2640 }
2641 
2642 static bool amt_discovery_handler(struct amt_dev *amt, struct sk_buff *skb)
2643 {
2644 	struct amt_header_discovery *amtd;
2645 	struct udphdr *udph;
2646 	struct iphdr *iph;
2647 
2648 	if (!pskb_may_pull(skb, sizeof(*udph) + sizeof(*amtd)))
2649 		return true;
2650 
2651 	iph = ip_hdr(skb);
2652 	udph = udp_hdr(skb);
2653 	amtd = (struct amt_header_discovery *)(udp_hdr(skb) + 1);
2654 
2655 	if (amtd->reserved || amtd->version)
2656 		return true;
2657 
2658 	amt_send_advertisement(amt, amtd->nonce, iph->saddr, udph->source);
2659 
2660 	return false;
2661 }
2662 
2663 static bool amt_request_handler(struct amt_dev *amt, struct sk_buff *skb)
2664 {
2665 	struct amt_header_request *amtrh;
2666 	struct amt_tunnel_list *tunnel;
2667 	unsigned long long key;
2668 	struct udphdr *udph;
2669 	struct iphdr *iph;
2670 	u64 mac;
2671 	int i;
2672 
2673 	if (!pskb_may_pull(skb, sizeof(*udph) + sizeof(*amtrh)))
2674 		return true;
2675 
2676 	iph = ip_hdr(skb);
2677 	udph = udp_hdr(skb);
2678 	amtrh = (struct amt_header_request *)(udp_hdr(skb) + 1);
2679 
2680 	if (amtrh->reserved1 || amtrh->reserved2 || amtrh->version)
2681 		return true;
2682 
2683 	list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list)
2684 		if (tunnel->ip4 == iph->saddr)
2685 			goto send;
2686 
2687 	spin_lock_bh(&amt->lock);
2688 	if (amt->nr_tunnels >= amt->max_tunnels) {
2689 		spin_unlock_bh(&amt->lock);
2690 		icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
2691 		return true;
2692 	}
2693 
2694 	tunnel = kzalloc(sizeof(*tunnel) +
2695 			 (sizeof(struct hlist_head) * amt->hash_buckets),
2696 			 GFP_ATOMIC);
2697 	if (!tunnel) {
2698 		spin_unlock_bh(&amt->lock);
2699 		return true;
2700 	}
2701 
2702 	tunnel->source_port = udph->source;
2703 	tunnel->ip4 = iph->saddr;
2704 
2705 	memcpy(&key, &tunnel->key, sizeof(unsigned long long));
2706 	tunnel->amt = amt;
2707 	spin_lock_init(&tunnel->lock);
2708 	for (i = 0; i < amt->hash_buckets; i++)
2709 		INIT_HLIST_HEAD(&tunnel->groups[i]);
2710 
2711 	INIT_DELAYED_WORK(&tunnel->gc_wq, amt_tunnel_expire);
2712 
2713 	list_add_tail_rcu(&tunnel->list, &amt->tunnel_list);
2714 	tunnel->key = amt->key;
2715 	__amt_update_relay_status(tunnel, AMT_STATUS_RECEIVED_REQUEST, true);
2716 	amt->nr_tunnels++;
2717 	mod_delayed_work(amt_wq, &tunnel->gc_wq,
2718 			 msecs_to_jiffies(amt_gmi(amt)));
2719 	spin_unlock_bh(&amt->lock);
2720 
2721 send:
2722 	tunnel->nonce = amtrh->nonce;
2723 	mac = siphash_3u32((__force u32)tunnel->ip4,
2724 			   (__force u32)tunnel->source_port,
2725 			   (__force u32)tunnel->nonce,
2726 			   &tunnel->key);
2727 	tunnel->mac = mac >> 16;
2728 
2729 	if (!netif_running(amt->dev) || !netif_running(amt->stream_dev))
2730 		return true;
2731 
2732 	if (!amtrh->p)
2733 		amt_send_igmp_gq(amt, tunnel);
2734 	else
2735 		amt_send_mld_gq(amt, tunnel);
2736 
2737 	return false;
2738 }
2739 
2740 static void amt_gw_rcv(struct amt_dev *amt, struct sk_buff *skb)
2741 {
2742 	int type = amt_parse_type(skb);
2743 	int err = 1;
2744 
2745 	if (type == -1)
2746 		goto drop;
2747 
2748 	if (amt->mode == AMT_MODE_GATEWAY) {
2749 		switch (type) {
2750 		case AMT_MSG_ADVERTISEMENT:
2751 			err = amt_advertisement_handler(amt, skb);
2752 			break;
2753 		case AMT_MSG_MEMBERSHIP_QUERY:
2754 			err = amt_membership_query_handler(amt, skb);
2755 			if (!err)
2756 				return;
2757 			break;
2758 		default:
2759 			netdev_dbg(amt->dev, "Invalid type of Gateway\n");
2760 			break;
2761 		}
2762 	}
2763 drop:
2764 	if (err) {
2765 		amt->dev->stats.rx_dropped++;
2766 		kfree_skb(skb);
2767 	} else {
2768 		consume_skb(skb);
2769 	}
2770 }
2771 
2772 static int amt_rcv(struct sock *sk, struct sk_buff *skb)
2773 {
2774 	struct amt_dev *amt;
2775 	struct iphdr *iph;
2776 	int type;
2777 	bool err;
2778 
2779 	rcu_read_lock_bh();
2780 	amt = rcu_dereference_sk_user_data(sk);
2781 	if (!amt) {
2782 		err = true;
2783 		kfree_skb(skb);
2784 		goto out;
2785 	}
2786 
2787 	skb->dev = amt->dev;
2788 	iph = ip_hdr(skb);
2789 	type = amt_parse_type(skb);
2790 	if (type == -1) {
2791 		err = true;
2792 		goto drop;
2793 	}
2794 
2795 	if (amt->mode == AMT_MODE_GATEWAY) {
2796 		switch (type) {
2797 		case AMT_MSG_ADVERTISEMENT:
2798 			if (iph->saddr != amt->discovery_ip) {
2799 				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2800 				err = true;
2801 				goto drop;
2802 			}
2803 			if (amt_queue_event(amt, AMT_EVENT_RECEIVE, skb)) {
2804 				netdev_dbg(amt->dev, "AMT Event queue full\n");
2805 				err = true;
2806 				goto drop;
2807 			}
2808 			goto out;
2809 		case AMT_MSG_MULTICAST_DATA:
2810 			if (iph->saddr != amt->remote_ip) {
2811 				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2812 				err = true;
2813 				goto drop;
2814 			}
2815 			err = amt_multicast_data_handler(amt, skb);
2816 			if (err)
2817 				goto drop;
2818 			else
2819 				goto out;
2820 		case AMT_MSG_MEMBERSHIP_QUERY:
2821 			if (iph->saddr != amt->remote_ip) {
2822 				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2823 				err = true;
2824 				goto drop;
2825 			}
2826 			if (amt_queue_event(amt, AMT_EVENT_RECEIVE, skb)) {
2827 				netdev_dbg(amt->dev, "AMT Event queue full\n");
2828 				err = true;
2829 				goto drop;
2830 			}
2831 			goto out;
2832 		default:
2833 			err = true;
2834 			netdev_dbg(amt->dev, "Invalid type of Gateway\n");
2835 			break;
2836 		}
2837 	} else {
2838 		switch (type) {
2839 		case AMT_MSG_DISCOVERY:
2840 			err = amt_discovery_handler(amt, skb);
2841 			break;
2842 		case AMT_MSG_REQUEST:
2843 			err = amt_request_handler(amt, skb);
2844 			break;
2845 		case AMT_MSG_MEMBERSHIP_UPDATE:
2846 			err = amt_update_handler(amt, skb);
2847 			if (err)
2848 				goto drop;
2849 			else
2850 				goto out;
2851 		default:
2852 			err = true;
2853 			netdev_dbg(amt->dev, "Invalid type of relay\n");
2854 			break;
2855 		}
2856 	}
2857 drop:
2858 	if (err) {
2859 		amt->dev->stats.rx_dropped++;
2860 		kfree_skb(skb);
2861 	} else {
2862 		consume_skb(skb);
2863 	}
2864 out:
2865 	rcu_read_unlock_bh();
2866 	return 0;
2867 }
2868 
2869 static void amt_event_work(struct work_struct *work)
2870 {
2871 	struct amt_dev *amt = container_of(work, struct amt_dev, event_wq);
2872 	struct sk_buff *skb;
2873 	u8 event;
2874 	int i;
2875 
2876 	for (i = 0; i < AMT_MAX_EVENTS; i++) {
2877 		spin_lock_bh(&amt->lock);
2878 		if (amt->nr_events == 0) {
2879 			spin_unlock_bh(&amt->lock);
2880 			return;
2881 		}
2882 		event = amt->events[amt->event_idx].event;
2883 		skb = amt->events[amt->event_idx].skb;
2884 		amt->events[amt->event_idx].event = AMT_EVENT_NONE;
2885 		amt->events[amt->event_idx].skb = NULL;
2886 		amt->nr_events--;
2887 		amt->event_idx++;
2888 		amt->event_idx %= AMT_MAX_EVENTS;
2889 		spin_unlock_bh(&amt->lock);
2890 
2891 		switch (event) {
2892 		case AMT_EVENT_RECEIVE:
2893 			amt_gw_rcv(amt, skb);
2894 			break;
2895 		case AMT_EVENT_SEND_DISCOVERY:
2896 			amt_event_send_discovery(amt);
2897 			break;
2898 		case AMT_EVENT_SEND_REQUEST:
2899 			amt_event_send_request(amt);
2900 			break;
2901 		default:
2902 			kfree_skb(skb);
2903 			break;
2904 		}
2905 	}
2906 }
2907 
2908 static int amt_err_lookup(struct sock *sk, struct sk_buff *skb)
2909 {
2910 	struct amt_dev *amt;
2911 	int type;
2912 
2913 	rcu_read_lock_bh();
2914 	amt = rcu_dereference_sk_user_data(sk);
2915 	if (!amt)
2916 		goto out;
2917 
2918 	if (amt->mode != AMT_MODE_GATEWAY)
2919 		goto drop;
2920 
2921 	type = amt_parse_type(skb);
2922 	if (type == -1)
2923 		goto drop;
2924 
2925 	netdev_dbg(amt->dev, "Received IGMP Unreachable of %s\n",
2926 		   type_str[type]);
2927 	switch (type) {
2928 	case AMT_MSG_DISCOVERY:
2929 		break;
2930 	case AMT_MSG_REQUEST:
2931 	case AMT_MSG_MEMBERSHIP_UPDATE:
2932 		if (READ_ONCE(amt->status) >= AMT_STATUS_RECEIVED_ADVERTISEMENT)
2933 			mod_delayed_work(amt_wq, &amt->req_wq, 0);
2934 		break;
2935 	default:
2936 		goto drop;
2937 	}
2938 out:
2939 	rcu_read_unlock_bh();
2940 	return 0;
2941 drop:
2942 	rcu_read_unlock_bh();
2943 	amt->dev->stats.rx_dropped++;
2944 	return 0;
2945 }
2946 
2947 static struct socket *amt_create_sock(struct net *net, __be16 port)
2948 {
2949 	struct udp_port_cfg udp_conf;
2950 	struct socket *sock;
2951 	int err;
2952 
2953 	memset(&udp_conf, 0, sizeof(udp_conf));
2954 	udp_conf.family = AF_INET;
2955 	udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
2956 
2957 	udp_conf.local_udp_port = port;
2958 
2959 	err = udp_sock_create(net, &udp_conf, &sock);
2960 	if (err < 0)
2961 		return ERR_PTR(err);
2962 
2963 	return sock;
2964 }
2965 
2966 static int amt_socket_create(struct amt_dev *amt)
2967 {
2968 	struct udp_tunnel_sock_cfg tunnel_cfg;
2969 	struct socket *sock;
2970 
2971 	sock = amt_create_sock(amt->net, amt->relay_port);
2972 	if (IS_ERR(sock))
2973 		return PTR_ERR(sock);
2974 
2975 	/* Mark socket as an encapsulation socket */
2976 	memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
2977 	tunnel_cfg.sk_user_data = amt;
2978 	tunnel_cfg.encap_type = 1;
2979 	tunnel_cfg.encap_rcv = amt_rcv;
2980 	tunnel_cfg.encap_err_lookup = amt_err_lookup;
2981 	tunnel_cfg.encap_destroy = NULL;
2982 	setup_udp_tunnel_sock(amt->net, sock, &tunnel_cfg);
2983 
2984 	rcu_assign_pointer(amt->sock, sock);
2985 	return 0;
2986 }
2987 
2988 static int amt_dev_open(struct net_device *dev)
2989 {
2990 	struct amt_dev *amt = netdev_priv(dev);
2991 	int err;
2992 
2993 	amt->ready4 = false;
2994 	amt->ready6 = false;
2995 	amt->event_idx = 0;
2996 	amt->nr_events = 0;
2997 
2998 	err = amt_socket_create(amt);
2999 	if (err)
3000 		return err;
3001 
3002 	amt->req_cnt = 0;
3003 	amt->remote_ip = 0;
3004 	amt->nonce = 0;
3005 	get_random_bytes(&amt->key, sizeof(siphash_key_t));
3006 
3007 	amt->status = AMT_STATUS_INIT;
3008 	if (amt->mode == AMT_MODE_GATEWAY) {
3009 		mod_delayed_work(amt_wq, &amt->discovery_wq, 0);
3010 		mod_delayed_work(amt_wq, &amt->req_wq, 0);
3011 	} else if (amt->mode == AMT_MODE_RELAY) {
3012 		mod_delayed_work(amt_wq, &amt->secret_wq,
3013 				 msecs_to_jiffies(AMT_SECRET_TIMEOUT));
3014 	}
3015 	return err;
3016 }
3017 
3018 static int amt_dev_stop(struct net_device *dev)
3019 {
3020 	struct amt_dev *amt = netdev_priv(dev);
3021 	struct amt_tunnel_list *tunnel, *tmp;
3022 	struct socket *sock;
3023 	struct sk_buff *skb;
3024 	int i;
3025 
3026 	cancel_delayed_work_sync(&amt->req_wq);
3027 	cancel_delayed_work_sync(&amt->discovery_wq);
3028 	cancel_delayed_work_sync(&amt->secret_wq);
3029 
3030 	/* shutdown */
3031 	sock = rtnl_dereference(amt->sock);
3032 	RCU_INIT_POINTER(amt->sock, NULL);
3033 	synchronize_net();
3034 	if (sock)
3035 		udp_tunnel_sock_release(sock);
3036 
3037 	cancel_work_sync(&amt->event_wq);
3038 	for (i = 0; i < AMT_MAX_EVENTS; i++) {
3039 		skb = amt->events[i].skb;
3040 		kfree_skb(skb);
3041 		amt->events[i].event = AMT_EVENT_NONE;
3042 		amt->events[i].skb = NULL;
3043 	}
3044 
3045 	amt->ready4 = false;
3046 	amt->ready6 = false;
3047 	amt->req_cnt = 0;
3048 	amt->remote_ip = 0;
3049 
3050 	list_for_each_entry_safe(tunnel, tmp, &amt->tunnel_list, list) {
3051 		list_del_rcu(&tunnel->list);
3052 		amt->nr_tunnels--;
3053 		cancel_delayed_work_sync(&tunnel->gc_wq);
3054 		amt_clear_groups(tunnel);
3055 		kfree_rcu(tunnel, rcu);
3056 	}
3057 
3058 	return 0;
3059 }
3060 
3061 static const struct device_type amt_type = {
3062 	.name = "amt",
3063 };
3064 
3065 static int amt_dev_init(struct net_device *dev)
3066 {
3067 	struct amt_dev *amt = netdev_priv(dev);
3068 	int err;
3069 
3070 	amt->dev = dev;
3071 
3072 	err = gro_cells_init(&amt->gro_cells, dev);
3073 	if (err)
3074 		return err;
3075 
3076 	return 0;
3077 }
3078 
3079 static void amt_dev_uninit(struct net_device *dev)
3080 {
3081 	struct amt_dev *amt = netdev_priv(dev);
3082 
3083 	gro_cells_destroy(&amt->gro_cells);
3084 }
3085 
3086 static const struct net_device_ops amt_netdev_ops = {
3087 	.ndo_init               = amt_dev_init,
3088 	.ndo_uninit             = amt_dev_uninit,
3089 	.ndo_open		= amt_dev_open,
3090 	.ndo_stop		= amt_dev_stop,
3091 	.ndo_start_xmit         = amt_dev_xmit,
3092 };
3093 
3094 static void amt_link_setup(struct net_device *dev)
3095 {
3096 	dev->netdev_ops         = &amt_netdev_ops;
3097 	dev->needs_free_netdev  = true;
3098 	SET_NETDEV_DEVTYPE(dev, &amt_type);
3099 	dev->min_mtu		= ETH_MIN_MTU;
3100 	dev->max_mtu		= ETH_MAX_MTU;
3101 	dev->type		= ARPHRD_NONE;
3102 	dev->flags		= IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
3103 	dev->hard_header_len	= 0;
3104 	dev->addr_len		= 0;
3105 	dev->priv_flags		|= IFF_NO_QUEUE;
3106 	dev->lltx		= true;
3107 	dev->netns_immutable	= true;
3108 	dev->features		|= NETIF_F_GSO_SOFTWARE;
3109 	dev->hw_features	|= NETIF_F_SG | NETIF_F_HW_CSUM;
3110 	dev->hw_features	|= NETIF_F_FRAGLIST | NETIF_F_RXCSUM;
3111 	dev->hw_features	|= NETIF_F_GSO_SOFTWARE;
3112 	dev->pcpu_stat_type	= NETDEV_PCPU_STAT_TSTATS;
3113 	eth_hw_addr_random(dev);
3114 	eth_zero_addr(dev->broadcast);
3115 	ether_setup(dev);
3116 }
3117 
3118 static const struct nla_policy amt_policy[IFLA_AMT_MAX + 1] = {
3119 	[IFLA_AMT_MODE]		= { .type = NLA_U32 },
3120 	[IFLA_AMT_RELAY_PORT]	= { .type = NLA_U16 },
3121 	[IFLA_AMT_GATEWAY_PORT]	= { .type = NLA_U16 },
3122 	[IFLA_AMT_LINK]		= { .type = NLA_U32 },
3123 	[IFLA_AMT_LOCAL_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
3124 	[IFLA_AMT_REMOTE_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
3125 	[IFLA_AMT_DISCOVERY_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
3126 	[IFLA_AMT_MAX_TUNNELS]	= { .type = NLA_U32 },
3127 };
3128 
3129 static int amt_validate(struct nlattr *tb[], struct nlattr *data[],
3130 			struct netlink_ext_ack *extack)
3131 {
3132 	if (!data)
3133 		return -EINVAL;
3134 
3135 	if (!data[IFLA_AMT_LINK]) {
3136 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_LINK],
3137 				    "Link attribute is required");
3138 		return -EINVAL;
3139 	}
3140 
3141 	if (!data[IFLA_AMT_MODE]) {
3142 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_MODE],
3143 				    "Mode attribute is required");
3144 		return -EINVAL;
3145 	}
3146 
3147 	if (nla_get_u32(data[IFLA_AMT_MODE]) > AMT_MODE_MAX) {
3148 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_MODE],
3149 				    "Mode attribute is not valid");
3150 		return -EINVAL;
3151 	}
3152 
3153 	if (!data[IFLA_AMT_LOCAL_IP]) {
3154 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_DISCOVERY_IP],
3155 				    "Local attribute is required");
3156 		return -EINVAL;
3157 	}
3158 
3159 	if (!data[IFLA_AMT_DISCOVERY_IP] &&
3160 	    nla_get_u32(data[IFLA_AMT_MODE]) == AMT_MODE_GATEWAY) {
3161 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_LOCAL_IP],
3162 				    "Discovery attribute is required");
3163 		return -EINVAL;
3164 	}
3165 
3166 	return 0;
3167 }
3168 
3169 static int amt_newlink(struct net_device *dev,
3170 		       struct rtnl_newlink_params *params,
3171 		       struct netlink_ext_ack *extack)
3172 {
3173 	struct net *link_net = rtnl_newlink_link_net(params);
3174 	struct amt_dev *amt = netdev_priv(dev);
3175 	struct nlattr **data = params->data;
3176 	struct nlattr **tb = params->tb;
3177 	int err = -EINVAL;
3178 
3179 	amt->net = link_net;
3180 	amt->mode = nla_get_u32(data[IFLA_AMT_MODE]);
3181 
3182 	if (data[IFLA_AMT_MAX_TUNNELS] &&
3183 	    nla_get_u32(data[IFLA_AMT_MAX_TUNNELS]))
3184 		amt->max_tunnels = nla_get_u32(data[IFLA_AMT_MAX_TUNNELS]);
3185 	else
3186 		amt->max_tunnels = AMT_MAX_TUNNELS;
3187 
3188 	spin_lock_init(&amt->lock);
3189 	amt->max_groups = AMT_MAX_GROUP;
3190 	amt->max_sources = AMT_MAX_SOURCE;
3191 	amt->hash_buckets = AMT_HSIZE;
3192 	amt->nr_tunnels = 0;
3193 	get_random_bytes(&amt->hash_seed, sizeof(amt->hash_seed));
3194 	amt->stream_dev = dev_get_by_index(link_net,
3195 					   nla_get_u32(data[IFLA_AMT_LINK]));
3196 	if (!amt->stream_dev) {
3197 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LINK],
3198 				    "Can't find stream device");
3199 		return -ENODEV;
3200 	}
3201 
3202 	if (amt->stream_dev->type != ARPHRD_ETHER) {
3203 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LINK],
3204 				    "Invalid stream device type");
3205 		goto err;
3206 	}
3207 
3208 	amt->local_ip = nla_get_in_addr(data[IFLA_AMT_LOCAL_IP]);
3209 	if (ipv4_is_loopback(amt->local_ip) ||
3210 	    ipv4_is_zeronet(amt->local_ip) ||
3211 	    ipv4_is_multicast(amt->local_ip)) {
3212 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LOCAL_IP],
3213 				    "Invalid Local address");
3214 		goto err;
3215 	}
3216 
3217 	amt->relay_port = nla_get_be16_default(data[IFLA_AMT_RELAY_PORT],
3218 					       htons(IANA_AMT_UDP_PORT));
3219 
3220 	amt->gw_port = nla_get_be16_default(data[IFLA_AMT_GATEWAY_PORT],
3221 					    htons(IANA_AMT_UDP_PORT));
3222 
3223 	if (!amt->relay_port) {
3224 		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3225 				    "relay port must not be 0");
3226 		goto err;
3227 	}
3228 	if (amt->mode == AMT_MODE_RELAY) {
3229 		amt->qrv = READ_ONCE(amt->net->ipv4.sysctl_igmp_qrv);
3230 		amt->qri = 10;
3231 		dev->needed_headroom = amt->stream_dev->needed_headroom +
3232 				       AMT_RELAY_HLEN;
3233 		dev->mtu = amt->stream_dev->mtu - AMT_RELAY_HLEN;
3234 		dev->max_mtu = dev->mtu;
3235 		dev->min_mtu = ETH_MIN_MTU + AMT_RELAY_HLEN;
3236 	} else {
3237 		if (!data[IFLA_AMT_DISCOVERY_IP]) {
3238 			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3239 					    "discovery must be set in gateway mode");
3240 			goto err;
3241 		}
3242 		if (!amt->gw_port) {
3243 			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3244 					    "gateway port must not be 0");
3245 			goto err;
3246 		}
3247 		amt->remote_ip = 0;
3248 		amt->discovery_ip = nla_get_in_addr(data[IFLA_AMT_DISCOVERY_IP]);
3249 		if (ipv4_is_loopback(amt->discovery_ip) ||
3250 		    ipv4_is_zeronet(amt->discovery_ip) ||
3251 		    ipv4_is_multicast(amt->discovery_ip)) {
3252 			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3253 					    "discovery must be unicast");
3254 			goto err;
3255 		}
3256 
3257 		dev->needed_headroom = amt->stream_dev->needed_headroom +
3258 				       AMT_GW_HLEN;
3259 		dev->mtu = amt->stream_dev->mtu - AMT_GW_HLEN;
3260 		dev->max_mtu = dev->mtu;
3261 		dev->min_mtu = ETH_MIN_MTU + AMT_GW_HLEN;
3262 	}
3263 	amt->qi = AMT_INIT_QUERY_INTERVAL;
3264 
3265 	err = register_netdevice(dev);
3266 	if (err < 0) {
3267 		netdev_dbg(dev, "failed to register new netdev %d\n", err);
3268 		goto err;
3269 	}
3270 
3271 	err = netdev_upper_dev_link(amt->stream_dev, dev, extack);
3272 	if (err < 0) {
3273 		unregister_netdevice(dev);
3274 		goto err;
3275 	}
3276 
3277 	INIT_DELAYED_WORK(&amt->discovery_wq, amt_discovery_work);
3278 	INIT_DELAYED_WORK(&amt->req_wq, amt_req_work);
3279 	INIT_DELAYED_WORK(&amt->secret_wq, amt_secret_work);
3280 	INIT_WORK(&amt->event_wq, amt_event_work);
3281 	INIT_LIST_HEAD(&amt->tunnel_list);
3282 	return 0;
3283 err:
3284 	dev_put(amt->stream_dev);
3285 	return err;
3286 }
3287 
3288 static void amt_dellink(struct net_device *dev, struct list_head *head)
3289 {
3290 	struct amt_dev *amt = netdev_priv(dev);
3291 
3292 	unregister_netdevice_queue(dev, head);
3293 	netdev_upper_dev_unlink(amt->stream_dev, dev);
3294 	dev_put(amt->stream_dev);
3295 }
3296 
3297 static size_t amt_get_size(const struct net_device *dev)
3298 {
3299 	return nla_total_size(sizeof(__u32)) + /* IFLA_AMT_MODE */
3300 	       nla_total_size(sizeof(__u16)) + /* IFLA_AMT_RELAY_PORT */
3301 	       nla_total_size(sizeof(__u16)) + /* IFLA_AMT_GATEWAY_PORT */
3302 	       nla_total_size(sizeof(__u32)) + /* IFLA_AMT_LINK */
3303 	       nla_total_size(sizeof(__u32)) + /* IFLA_MAX_TUNNELS */
3304 	       nla_total_size(sizeof(struct iphdr)) + /* IFLA_AMT_DISCOVERY_IP */
3305 	       nla_total_size(sizeof(struct iphdr)) + /* IFLA_AMT_REMOTE_IP */
3306 	       nla_total_size(sizeof(struct iphdr)); /* IFLA_AMT_LOCAL_IP */
3307 }
3308 
3309 static int amt_fill_info(struct sk_buff *skb, const struct net_device *dev)
3310 {
3311 	struct amt_dev *amt = netdev_priv(dev);
3312 
3313 	if (nla_put_u32(skb, IFLA_AMT_MODE, amt->mode))
3314 		goto nla_put_failure;
3315 	if (nla_put_be16(skb, IFLA_AMT_RELAY_PORT, amt->relay_port))
3316 		goto nla_put_failure;
3317 	if (nla_put_be16(skb, IFLA_AMT_GATEWAY_PORT, amt->gw_port))
3318 		goto nla_put_failure;
3319 	if (nla_put_u32(skb, IFLA_AMT_LINK, amt->stream_dev->ifindex))
3320 		goto nla_put_failure;
3321 	if (nla_put_in_addr(skb, IFLA_AMT_LOCAL_IP, amt->local_ip))
3322 		goto nla_put_failure;
3323 	if (nla_put_in_addr(skb, IFLA_AMT_DISCOVERY_IP, amt->discovery_ip))
3324 		goto nla_put_failure;
3325 	if (amt->remote_ip)
3326 		if (nla_put_in_addr(skb, IFLA_AMT_REMOTE_IP, amt->remote_ip))
3327 			goto nla_put_failure;
3328 	if (nla_put_u32(skb, IFLA_AMT_MAX_TUNNELS, amt->max_tunnels))
3329 		goto nla_put_failure;
3330 
3331 	return 0;
3332 
3333 nla_put_failure:
3334 	return -EMSGSIZE;
3335 }
3336 
3337 static struct rtnl_link_ops amt_link_ops __read_mostly = {
3338 	.kind		= "amt",
3339 	.maxtype	= IFLA_AMT_MAX,
3340 	.policy		= amt_policy,
3341 	.priv_size	= sizeof(struct amt_dev),
3342 	.setup		= amt_link_setup,
3343 	.validate	= amt_validate,
3344 	.newlink	= amt_newlink,
3345 	.dellink	= amt_dellink,
3346 	.get_size       = amt_get_size,
3347 	.fill_info      = amt_fill_info,
3348 };
3349 
3350 static struct net_device *amt_lookup_upper_dev(struct net_device *dev)
3351 {
3352 	struct net_device *upper_dev;
3353 	struct amt_dev *amt;
3354 
3355 	for_each_netdev(dev_net(dev), upper_dev) {
3356 		if (netif_is_amt(upper_dev)) {
3357 			amt = netdev_priv(upper_dev);
3358 			if (amt->stream_dev == dev)
3359 				return upper_dev;
3360 		}
3361 	}
3362 
3363 	return NULL;
3364 }
3365 
3366 static int amt_device_event(struct notifier_block *unused,
3367 			    unsigned long event, void *ptr)
3368 {
3369 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3370 	struct net_device *upper_dev;
3371 	struct amt_dev *amt;
3372 	LIST_HEAD(list);
3373 	int new_mtu;
3374 
3375 	upper_dev = amt_lookup_upper_dev(dev);
3376 	if (!upper_dev)
3377 		return NOTIFY_DONE;
3378 	amt = netdev_priv(upper_dev);
3379 
3380 	switch (event) {
3381 	case NETDEV_UNREGISTER:
3382 		amt_dellink(amt->dev, &list);
3383 		unregister_netdevice_many(&list);
3384 		break;
3385 	case NETDEV_CHANGEMTU:
3386 		if (amt->mode == AMT_MODE_RELAY)
3387 			new_mtu = dev->mtu - AMT_RELAY_HLEN;
3388 		else
3389 			new_mtu = dev->mtu - AMT_GW_HLEN;
3390 
3391 		dev_set_mtu(amt->dev, new_mtu);
3392 		break;
3393 	}
3394 
3395 	return NOTIFY_DONE;
3396 }
3397 
3398 static struct notifier_block amt_notifier_block __read_mostly = {
3399 	.notifier_call = amt_device_event,
3400 };
3401 
3402 static int __init amt_init(void)
3403 {
3404 	int err;
3405 
3406 	err = register_netdevice_notifier(&amt_notifier_block);
3407 	if (err < 0)
3408 		goto err;
3409 
3410 	err = rtnl_link_register(&amt_link_ops);
3411 	if (err < 0)
3412 		goto unregister_notifier;
3413 
3414 	amt_wq = alloc_workqueue("amt", WQ_UNBOUND, 0);
3415 	if (!amt_wq) {
3416 		err = -ENOMEM;
3417 		goto rtnl_unregister;
3418 	}
3419 
3420 	spin_lock_init(&source_gc_lock);
3421 	spin_lock_bh(&source_gc_lock);
3422 	INIT_DELAYED_WORK(&source_gc_wq, amt_source_gc_work);
3423 	mod_delayed_work(amt_wq, &source_gc_wq,
3424 			 msecs_to_jiffies(AMT_GC_INTERVAL));
3425 	spin_unlock_bh(&source_gc_lock);
3426 
3427 	return 0;
3428 
3429 rtnl_unregister:
3430 	rtnl_link_unregister(&amt_link_ops);
3431 unregister_notifier:
3432 	unregister_netdevice_notifier(&amt_notifier_block);
3433 err:
3434 	pr_err("error loading AMT module loaded\n");
3435 	return err;
3436 }
3437 late_initcall(amt_init);
3438 
3439 static void __exit amt_fini(void)
3440 {
3441 	rtnl_link_unregister(&amt_link_ops);
3442 	unregister_netdevice_notifier(&amt_notifier_block);
3443 	cancel_delayed_work_sync(&source_gc_wq);
3444 	__amt_source_gc_work();
3445 	destroy_workqueue(amt_wq);
3446 }
3447 module_exit(amt_fini);
3448 
3449 MODULE_LICENSE("GPL");
3450 MODULE_DESCRIPTION("Driver for Automatic Multicast Tunneling (AMT)");
3451 MODULE_AUTHOR("Taehee Yoo <ap420073@gmail.com>");
3452 MODULE_ALIAS_RTNL_LINK("amt");
3453