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/pkt_sched.h>
15#include <net/net_namespace.h>
16#include <net/ip.h>
17#include <net/udp.h>
18#include <net/udp_tunnel.h>
19#include <net/icmp.h>
20#include <net/mld.h>
21#include <net/amt.h>
22#include <uapi/linux/amt.h>
23#include <linux/security.h>
24#include <net/gro_cells.h>
25#include <net/ipv6.h>
26#include <net/if_inet6.h>
27#include <net/ndisc.h>
28#include <net/addrconf.h>
29#include <net/ip6_route.h>
30#include <net/inet_common.h>
31#include <net/ip6_checksum.h>
32
33static struct workqueue_struct *amt_wq;
34
35static HLIST_HEAD(source_gc_list);
36/* Lock for source_gc_list */
37static spinlock_t source_gc_lock;
38static struct delayed_work source_gc_wq;
39static char *status_str[] = {
40	"AMT_STATUS_INIT",
41	"AMT_STATUS_SENT_DISCOVERY",
42	"AMT_STATUS_RECEIVED_DISCOVERY",
43	"AMT_STATUS_SENT_ADVERTISEMENT",
44	"AMT_STATUS_RECEIVED_ADVERTISEMENT",
45	"AMT_STATUS_SENT_REQUEST",
46	"AMT_STATUS_RECEIVED_REQUEST",
47	"AMT_STATUS_SENT_QUERY",
48	"AMT_STATUS_RECEIVED_QUERY",
49	"AMT_STATUS_SENT_UPDATE",
50	"AMT_STATUS_RECEIVED_UPDATE",
51};
52
53static char *type_str[] = {
54	"", /* Type 0 is not defined */
55	"AMT_MSG_DISCOVERY",
56	"AMT_MSG_ADVERTISEMENT",
57	"AMT_MSG_REQUEST",
58	"AMT_MSG_MEMBERSHIP_QUERY",
59	"AMT_MSG_MEMBERSHIP_UPDATE",
60	"AMT_MSG_MULTICAST_DATA",
61	"AMT_MSG_TEARDOWN",
62};
63
64static char *action_str[] = {
65	"AMT_ACT_GMI",
66	"AMT_ACT_GMI_ZERO",
67	"AMT_ACT_GT",
68	"AMT_ACT_STATUS_FWD_NEW",
69	"AMT_ACT_STATUS_D_FWD_NEW",
70	"AMT_ACT_STATUS_NONE_NEW",
71};
72
73static struct igmpv3_grec igmpv3_zero_grec;
74
75#if IS_ENABLED(CONFIG_IPV6)
76#define MLD2_ALL_NODE_INIT { { { 0xff, 0x02, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x01 } } }
77static struct in6_addr mld2_all_node = MLD2_ALL_NODE_INIT;
78static struct mld2_grec mldv2_zero_grec;
79#endif
80
81static struct amt_skb_cb *amt_skb_cb(struct sk_buff *skb)
82{
83	BUILD_BUG_ON(sizeof(struct amt_skb_cb) + sizeof(struct tc_skb_cb) >
84		     sizeof_field(struct sk_buff, cb));
85
86	return (struct amt_skb_cb *)((void *)skb->cb +
87		sizeof(struct tc_skb_cb));
88}
89
90static void __amt_source_gc_work(void)
91{
92	struct amt_source_node *snode;
93	struct hlist_head gc_list;
94	struct hlist_node *t;
95
96	spin_lock_bh(&source_gc_lock);
97	hlist_move_list(&source_gc_list, &gc_list);
98	spin_unlock_bh(&source_gc_lock);
99
100	hlist_for_each_entry_safe(snode, t, &gc_list, node) {
101		hlist_del_rcu(&snode->node);
102		kfree_rcu(snode, rcu);
103	}
104}
105
106static void amt_source_gc_work(struct work_struct *work)
107{
108	__amt_source_gc_work();
109
110	spin_lock_bh(&source_gc_lock);
111	mod_delayed_work(amt_wq, &source_gc_wq,
112			 msecs_to_jiffies(AMT_GC_INTERVAL));
113	spin_unlock_bh(&source_gc_lock);
114}
115
116static bool amt_addr_equal(union amt_addr *a, union amt_addr *b)
117{
118	return !memcmp(a, b, sizeof(union amt_addr));
119}
120
121static u32 amt_source_hash(struct amt_tunnel_list *tunnel, union amt_addr *src)
122{
123	u32 hash = jhash(src, sizeof(*src), tunnel->amt->hash_seed);
124
125	return reciprocal_scale(hash, tunnel->amt->hash_buckets);
126}
127
128static bool amt_status_filter(struct amt_source_node *snode,
129			      enum amt_filter filter)
130{
131	bool rc = false;
132
133	switch (filter) {
134	case AMT_FILTER_FWD:
135		if (snode->status == AMT_SOURCE_STATUS_FWD &&
136		    snode->flags == AMT_SOURCE_OLD)
137			rc = true;
138		break;
139	case AMT_FILTER_D_FWD:
140		if (snode->status == AMT_SOURCE_STATUS_D_FWD &&
141		    snode->flags == AMT_SOURCE_OLD)
142			rc = true;
143		break;
144	case AMT_FILTER_FWD_NEW:
145		if (snode->status == AMT_SOURCE_STATUS_FWD &&
146		    snode->flags == AMT_SOURCE_NEW)
147			rc = true;
148		break;
149	case AMT_FILTER_D_FWD_NEW:
150		if (snode->status == AMT_SOURCE_STATUS_D_FWD &&
151		    snode->flags == AMT_SOURCE_NEW)
152			rc = true;
153		break;
154	case AMT_FILTER_ALL:
155		rc = true;
156		break;
157	case AMT_FILTER_NONE_NEW:
158		if (snode->status == AMT_SOURCE_STATUS_NONE &&
159		    snode->flags == AMT_SOURCE_NEW)
160			rc = true;
161		break;
162	case AMT_FILTER_BOTH:
163		if ((snode->status == AMT_SOURCE_STATUS_D_FWD ||
164		     snode->status == AMT_SOURCE_STATUS_FWD) &&
165		    snode->flags == AMT_SOURCE_OLD)
166			rc = true;
167		break;
168	case AMT_FILTER_BOTH_NEW:
169		if ((snode->status == AMT_SOURCE_STATUS_D_FWD ||
170		     snode->status == AMT_SOURCE_STATUS_FWD) &&
171		    snode->flags == AMT_SOURCE_NEW)
172			rc = true;
173		break;
174	default:
175		WARN_ON_ONCE(1);
176		break;
177	}
178
179	return rc;
180}
181
182static struct amt_source_node *amt_lookup_src(struct amt_tunnel_list *tunnel,
183					      struct amt_group_node *gnode,
184					      enum amt_filter filter,
185					      union amt_addr *src)
186{
187	u32 hash = amt_source_hash(tunnel, src);
188	struct amt_source_node *snode;
189
190	hlist_for_each_entry_rcu(snode, &gnode->sources[hash], node)
191		if (amt_status_filter(snode, filter) &&
192		    amt_addr_equal(&snode->source_addr, src))
193			return snode;
194
195	return NULL;
196}
197
198static u32 amt_group_hash(struct amt_tunnel_list *tunnel, union amt_addr *group)
199{
200	u32 hash = jhash(group, sizeof(*group), tunnel->amt->hash_seed);
201
202	return reciprocal_scale(hash, tunnel->amt->hash_buckets);
203}
204
205static struct amt_group_node *amt_lookup_group(struct amt_tunnel_list *tunnel,
206					       union amt_addr *group,
207					       union amt_addr *host,
208					       bool v6)
209{
210	u32 hash = amt_group_hash(tunnel, group);
211	struct amt_group_node *gnode;
212
213	hlist_for_each_entry_rcu(gnode, &tunnel->groups[hash], node) {
214		if (amt_addr_equal(&gnode->group_addr, group) &&
215		    amt_addr_equal(&gnode->host_addr, host) &&
216		    gnode->v6 == v6)
217			return gnode;
218	}
219
220	return NULL;
221}
222
223static void amt_destroy_source(struct amt_source_node *snode)
224{
225	struct amt_group_node *gnode = snode->gnode;
226	struct amt_tunnel_list *tunnel;
227
228	tunnel = gnode->tunnel_list;
229
230	if (!gnode->v6) {
231		netdev_dbg(snode->gnode->amt->dev,
232			   "Delete source %pI4 from %pI4\n",
233			   &snode->source_addr.ip4,
234			   &gnode->group_addr.ip4);
235#if IS_ENABLED(CONFIG_IPV6)
236	} else {
237		netdev_dbg(snode->gnode->amt->dev,
238			   "Delete source %pI6 from %pI6\n",
239			   &snode->source_addr.ip6,
240			   &gnode->group_addr.ip6);
241#endif
242	}
243
244	cancel_delayed_work(&snode->source_timer);
245	hlist_del_init_rcu(&snode->node);
246	tunnel->nr_sources--;
247	gnode->nr_sources--;
248	spin_lock_bh(&source_gc_lock);
249	hlist_add_head_rcu(&snode->node, &source_gc_list);
250	spin_unlock_bh(&source_gc_lock);
251}
252
253static void amt_del_group(struct amt_dev *amt, struct amt_group_node *gnode)
254{
255	struct amt_source_node *snode;
256	struct hlist_node *t;
257	int i;
258
259	if (cancel_delayed_work(&gnode->group_timer))
260		dev_put(amt->dev);
261	hlist_del_rcu(&gnode->node);
262	gnode->tunnel_list->nr_groups--;
263
264	if (!gnode->v6)
265		netdev_dbg(amt->dev, "Leave group %pI4\n",
266			   &gnode->group_addr.ip4);
267#if IS_ENABLED(CONFIG_IPV6)
268	else
269		netdev_dbg(amt->dev, "Leave group %pI6\n",
270			   &gnode->group_addr.ip6);
271#endif
272	for (i = 0; i < amt->hash_buckets; i++)
273		hlist_for_each_entry_safe(snode, t, &gnode->sources[i], node)
274			amt_destroy_source(snode);
275
276	/* tunnel->lock was acquired outside of amt_del_group()
277	 * But rcu_read_lock() was acquired too so It's safe.
278	 */
279	kfree_rcu(gnode, rcu);
280}
281
282/* If a source timer expires with a router filter-mode for the group of
283 * INCLUDE, the router concludes that traffic from this particular
284 * source is no longer desired on the attached network, and deletes the
285 * associated source record.
286 */
287static void amt_source_work(struct work_struct *work)
288{
289	struct amt_source_node *snode = container_of(to_delayed_work(work),
290						     struct amt_source_node,
291						     source_timer);
292	struct amt_group_node *gnode = snode->gnode;
293	struct amt_dev *amt = gnode->amt;
294	struct amt_tunnel_list *tunnel;
295
296	tunnel = gnode->tunnel_list;
297	spin_lock_bh(&tunnel->lock);
298	rcu_read_lock();
299	if (gnode->filter_mode == MCAST_INCLUDE) {
300		amt_destroy_source(snode);
301		if (!gnode->nr_sources)
302			amt_del_group(amt, gnode);
303	} else {
304		/* When a router filter-mode for a group is EXCLUDE,
305		 * source records are only deleted when the group timer expires
306		 */
307		snode->status = AMT_SOURCE_STATUS_D_FWD;
308	}
309	rcu_read_unlock();
310	spin_unlock_bh(&tunnel->lock);
311}
312
313static void amt_act_src(struct amt_tunnel_list *tunnel,
314			struct amt_group_node *gnode,
315			struct amt_source_node *snode,
316			enum amt_act act)
317{
318	struct amt_dev *amt = tunnel->amt;
319
320	switch (act) {
321	case AMT_ACT_GMI:
322		mod_delayed_work(amt_wq, &snode->source_timer,
323				 msecs_to_jiffies(amt_gmi(amt)));
324		break;
325	case AMT_ACT_GMI_ZERO:
326		cancel_delayed_work(&snode->source_timer);
327		break;
328	case AMT_ACT_GT:
329		mod_delayed_work(amt_wq, &snode->source_timer,
330				 gnode->group_timer.timer.expires);
331		break;
332	case AMT_ACT_STATUS_FWD_NEW:
333		snode->status = AMT_SOURCE_STATUS_FWD;
334		snode->flags = AMT_SOURCE_NEW;
335		break;
336	case AMT_ACT_STATUS_D_FWD_NEW:
337		snode->status = AMT_SOURCE_STATUS_D_FWD;
338		snode->flags = AMT_SOURCE_NEW;
339		break;
340	case AMT_ACT_STATUS_NONE_NEW:
341		cancel_delayed_work(&snode->source_timer);
342		snode->status = AMT_SOURCE_STATUS_NONE;
343		snode->flags = AMT_SOURCE_NEW;
344		break;
345	default:
346		WARN_ON_ONCE(1);
347		return;
348	}
349
350	if (!gnode->v6)
351		netdev_dbg(amt->dev, "Source %pI4 from %pI4 Acted %s\n",
352			   &snode->source_addr.ip4,
353			   &gnode->group_addr.ip4,
354			   action_str[act]);
355#if IS_ENABLED(CONFIG_IPV6)
356	else
357		netdev_dbg(amt->dev, "Source %pI6 from %pI6 Acted %s\n",
358			   &snode->source_addr.ip6,
359			   &gnode->group_addr.ip6,
360			   action_str[act]);
361#endif
362}
363
364static struct amt_source_node *amt_alloc_snode(struct amt_group_node *gnode,
365					       union amt_addr *src)
366{
367	struct amt_source_node *snode;
368
369	snode = kzalloc(sizeof(*snode), GFP_ATOMIC);
370	if (!snode)
371		return NULL;
372
373	memcpy(&snode->source_addr, src, sizeof(union amt_addr));
374	snode->gnode = gnode;
375	snode->status = AMT_SOURCE_STATUS_NONE;
376	snode->flags = AMT_SOURCE_NEW;
377	INIT_HLIST_NODE(&snode->node);
378	INIT_DELAYED_WORK(&snode->source_timer, amt_source_work);
379
380	return snode;
381}
382
383/* RFC 3810 - 7.2.2.  Definition of Filter Timers
384 *
385 *  Router Mode          Filter Timer         Actions/Comments
386 *  -----------       -----------------       ----------------
387 *
388 *    INCLUDE             Not Used            All listeners in
389 *                                            INCLUDE mode.
390 *
391 *    EXCLUDE             Timer > 0           At least one listener
392 *                                            in EXCLUDE mode.
393 *
394 *    EXCLUDE             Timer == 0          No more listeners in
395 *                                            EXCLUDE mode for the
396 *                                            multicast address.
397 *                                            If the Requested List
398 *                                            is empty, delete
399 *                                            Multicast Address
400 *                                            Record.  If not, switch
401 *                                            to INCLUDE filter mode;
402 *                                            the sources in the
403 *                                            Requested List are
404 *                                            moved to the Include
405 *                                            List, and the Exclude
406 *                                            List is deleted.
407 */
408static void amt_group_work(struct work_struct *work)
409{
410	struct amt_group_node *gnode = container_of(to_delayed_work(work),
411						    struct amt_group_node,
412						    group_timer);
413	struct amt_tunnel_list *tunnel = gnode->tunnel_list;
414	struct amt_dev *amt = gnode->amt;
415	struct amt_source_node *snode;
416	bool delete_group = true;
417	struct hlist_node *t;
418	int i, buckets;
419
420	buckets = amt->hash_buckets;
421
422	spin_lock_bh(&tunnel->lock);
423	if (gnode->filter_mode == MCAST_INCLUDE) {
424		/* Not Used */
425		spin_unlock_bh(&tunnel->lock);
426		goto out;
427	}
428
429	rcu_read_lock();
430	for (i = 0; i < buckets; i++) {
431		hlist_for_each_entry_safe(snode, t,
432					  &gnode->sources[i], node) {
433			if (!delayed_work_pending(&snode->source_timer) ||
434			    snode->status == AMT_SOURCE_STATUS_D_FWD) {
435				amt_destroy_source(snode);
436			} else {
437				delete_group = false;
438				snode->status = AMT_SOURCE_STATUS_FWD;
439			}
440		}
441	}
442	if (delete_group)
443		amt_del_group(amt, gnode);
444	else
445		gnode->filter_mode = MCAST_INCLUDE;
446	rcu_read_unlock();
447	spin_unlock_bh(&tunnel->lock);
448out:
449	dev_put(amt->dev);
450}
451
452/* Non-existent group is created as INCLUDE {empty}:
453 *
454 * RFC 3376 - 5.1. Action on Change of Interface State
455 *
456 * If no interface state existed for that multicast address before
457 * the change (i.e., the change consisted of creating a new
458 * per-interface record), or if no state exists after the change
459 * (i.e., the change consisted of deleting a per-interface record),
460 * then the "non-existent" state is considered to have a filter mode
461 * of INCLUDE and an empty source list.
462 */
463static struct amt_group_node *amt_add_group(struct amt_dev *amt,
464					    struct amt_tunnel_list *tunnel,
465					    union amt_addr *group,
466					    union amt_addr *host,
467					    bool v6)
468{
469	struct amt_group_node *gnode;
470	u32 hash;
471	int i;
472
473	if (tunnel->nr_groups >= amt->max_groups)
474		return ERR_PTR(-ENOSPC);
475
476	gnode = kzalloc(sizeof(*gnode) +
477			(sizeof(struct hlist_head) * amt->hash_buckets),
478			GFP_ATOMIC);
479	if (unlikely(!gnode))
480		return ERR_PTR(-ENOMEM);
481
482	gnode->amt = amt;
483	gnode->group_addr = *group;
484	gnode->host_addr = *host;
485	gnode->v6 = v6;
486	gnode->tunnel_list = tunnel;
487	gnode->filter_mode = MCAST_INCLUDE;
488	INIT_HLIST_NODE(&gnode->node);
489	INIT_DELAYED_WORK(&gnode->group_timer, amt_group_work);
490	for (i = 0; i < amt->hash_buckets; i++)
491		INIT_HLIST_HEAD(&gnode->sources[i]);
492
493	hash = amt_group_hash(tunnel, group);
494	hlist_add_head_rcu(&gnode->node, &tunnel->groups[hash]);
495	tunnel->nr_groups++;
496
497	if (!gnode->v6)
498		netdev_dbg(amt->dev, "Join group %pI4\n",
499			   &gnode->group_addr.ip4);
500#if IS_ENABLED(CONFIG_IPV6)
501	else
502		netdev_dbg(amt->dev, "Join group %pI6\n",
503			   &gnode->group_addr.ip6);
504#endif
505
506	return gnode;
507}
508
509static struct sk_buff *amt_build_igmp_gq(struct amt_dev *amt)
510{
511	u8 ra[AMT_IPHDR_OPTS] = { IPOPT_RA, 4, 0, 0 };
512	int hlen = LL_RESERVED_SPACE(amt->dev);
513	int tlen = amt->dev->needed_tailroom;
514	struct igmpv3_query *ihv3;
515	void *csum_start = NULL;
516	__sum16 *csum = NULL;
517	struct sk_buff *skb;
518	struct ethhdr *eth;
519	struct iphdr *iph;
520	unsigned int len;
521	int offset;
522
523	len = hlen + tlen + sizeof(*iph) + AMT_IPHDR_OPTS + sizeof(*ihv3);
524	skb = netdev_alloc_skb_ip_align(amt->dev, len);
525	if (!skb)
526		return NULL;
527
528	skb_reserve(skb, hlen);
529	skb_push(skb, sizeof(*eth));
530	skb->protocol = htons(ETH_P_IP);
531	skb_reset_mac_header(skb);
532	skb->priority = TC_PRIO_CONTROL;
533	skb_put(skb, sizeof(*iph));
534	skb_put_data(skb, ra, sizeof(ra));
535	skb_put(skb, sizeof(*ihv3));
536	skb_pull(skb, sizeof(*eth));
537	skb_reset_network_header(skb);
538
539	iph		= ip_hdr(skb);
540	iph->version	= 4;
541	iph->ihl	= (sizeof(struct iphdr) + AMT_IPHDR_OPTS) >> 2;
542	iph->tos	= AMT_TOS;
543	iph->tot_len	= htons(sizeof(*iph) + AMT_IPHDR_OPTS + sizeof(*ihv3));
544	iph->frag_off	= htons(IP_DF);
545	iph->ttl	= 1;
546	iph->id		= 0;
547	iph->protocol	= IPPROTO_IGMP;
548	iph->daddr	= htonl(INADDR_ALLHOSTS_GROUP);
549	iph->saddr	= htonl(INADDR_ANY);
550	ip_send_check(iph);
551
552	eth = eth_hdr(skb);
553	ether_addr_copy(eth->h_source, amt->dev->dev_addr);
554	ip_eth_mc_map(htonl(INADDR_ALLHOSTS_GROUP), eth->h_dest);
555	eth->h_proto = htons(ETH_P_IP);
556
557	ihv3		= skb_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
558	skb_reset_transport_header(skb);
559	ihv3->type	= IGMP_HOST_MEMBERSHIP_QUERY;
560	ihv3->code	= 1;
561	ihv3->group	= 0;
562	ihv3->qqic	= amt->qi;
563	ihv3->nsrcs	= 0;
564	ihv3->resv	= 0;
565	ihv3->suppress	= false;
566	ihv3->qrv	= READ_ONCE(amt->net->ipv4.sysctl_igmp_qrv);
567	ihv3->csum	= 0;
568	csum		= &ihv3->csum;
569	csum_start	= (void *)ihv3;
570	*csum		= ip_compute_csum(csum_start, sizeof(*ihv3));
571	offset		= skb_transport_offset(skb);
572	skb->csum	= skb_checksum(skb, offset, skb->len - offset, 0);
573	skb->ip_summed	= CHECKSUM_NONE;
574
575	skb_push(skb, sizeof(*eth) + sizeof(*iph) + AMT_IPHDR_OPTS);
576
577	return skb;
578}
579
580static void amt_update_gw_status(struct amt_dev *amt, enum amt_status status,
581				 bool validate)
582{
583	if (validate && amt->status >= status)
584		return;
585	netdev_dbg(amt->dev, "Update GW status %s -> %s",
586		   status_str[amt->status], status_str[status]);
587	WRITE_ONCE(amt->status, status);
588}
589
590static void __amt_update_relay_status(struct amt_tunnel_list *tunnel,
591				      enum amt_status status,
592				      bool validate)
593{
594	if (validate && tunnel->status >= status)
595		return;
596	netdev_dbg(tunnel->amt->dev,
597		   "Update Tunnel(IP = %pI4, PORT = %u) status %s -> %s",
598		   &tunnel->ip4, ntohs(tunnel->source_port),
599		   status_str[tunnel->status], status_str[status]);
600	tunnel->status = status;
601}
602
603static void amt_update_relay_status(struct amt_tunnel_list *tunnel,
604				    enum amt_status status, bool validate)
605{
606	spin_lock_bh(&tunnel->lock);
607	__amt_update_relay_status(tunnel, status, validate);
608	spin_unlock_bh(&tunnel->lock);
609}
610
611static void amt_send_discovery(struct amt_dev *amt)
612{
613	struct amt_header_discovery *amtd;
614	int hlen, tlen, offset;
615	struct socket *sock;
616	struct udphdr *udph;
617	struct sk_buff *skb;
618	struct iphdr *iph;
619	struct rtable *rt;
620	struct flowi4 fl4;
621	u32 len;
622	int err;
623
624	rcu_read_lock();
625	sock = rcu_dereference(amt->sock);
626	if (!sock)
627		goto out;
628
629	if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
630		goto out;
631
632	rt = ip_route_output_ports(amt->net, &fl4, sock->sk,
633				   amt->discovery_ip, amt->local_ip,
634				   amt->gw_port, amt->relay_port,
635				   IPPROTO_UDP, 0,
636				   amt->stream_dev->ifindex);
637	if (IS_ERR(rt)) {
638		amt->dev->stats.tx_errors++;
639		goto out;
640	}
641
642	hlen = LL_RESERVED_SPACE(amt->dev);
643	tlen = amt->dev->needed_tailroom;
644	len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amtd);
645	skb = netdev_alloc_skb_ip_align(amt->dev, len);
646	if (!skb) {
647		ip_rt_put(rt);
648		amt->dev->stats.tx_errors++;
649		goto out;
650	}
651
652	skb->priority = TC_PRIO_CONTROL;
653	skb_dst_set(skb, &rt->dst);
654
655	len = sizeof(*iph) + sizeof(*udph) + sizeof(*amtd);
656	skb_reset_network_header(skb);
657	skb_put(skb, len);
658	amtd = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
659	amtd->version	= 0;
660	amtd->type	= AMT_MSG_DISCOVERY;
661	amtd->reserved	= 0;
662	amtd->nonce	= amt->nonce;
663	skb_push(skb, sizeof(*udph));
664	skb_reset_transport_header(skb);
665	udph		= udp_hdr(skb);
666	udph->source	= amt->gw_port;
667	udph->dest	= amt->relay_port;
668	udph->len	= htons(sizeof(*udph) + sizeof(*amtd));
669	udph->check	= 0;
670	offset = skb_transport_offset(skb);
671	skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
672	udph->check = csum_tcpudp_magic(amt->local_ip, amt->discovery_ip,
673					sizeof(*udph) + sizeof(*amtd),
674					IPPROTO_UDP, skb->csum);
675
676	skb_push(skb, sizeof(*iph));
677	iph		= ip_hdr(skb);
678	iph->version	= 4;
679	iph->ihl	= (sizeof(struct iphdr)) >> 2;
680	iph->tos	= AMT_TOS;
681	iph->frag_off	= 0;
682	iph->ttl	= ip4_dst_hoplimit(&rt->dst);
683	iph->daddr	= amt->discovery_ip;
684	iph->saddr	= amt->local_ip;
685	iph->protocol	= IPPROTO_UDP;
686	iph->tot_len	= htons(len);
687
688	skb->ip_summed = CHECKSUM_NONE;
689	ip_select_ident(amt->net, skb, NULL);
690	ip_send_check(iph);
691	err = ip_local_out(amt->net, sock->sk, skb);
692	if (unlikely(net_xmit_eval(err)))
693		amt->dev->stats.tx_errors++;
694
695	amt_update_gw_status(amt, AMT_STATUS_SENT_DISCOVERY, true);
696out:
697	rcu_read_unlock();
698}
699
700static void amt_send_request(struct amt_dev *amt, bool v6)
701{
702	struct amt_header_request *amtrh;
703	int hlen, tlen, offset;
704	struct socket *sock;
705	struct udphdr *udph;
706	struct sk_buff *skb;
707	struct iphdr *iph;
708	struct rtable *rt;
709	struct flowi4 fl4;
710	u32 len;
711	int err;
712
713	rcu_read_lock();
714	sock = rcu_dereference(amt->sock);
715	if (!sock)
716		goto out;
717
718	if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
719		goto out;
720
721	rt = ip_route_output_ports(amt->net, &fl4, sock->sk,
722				   amt->remote_ip, amt->local_ip,
723				   amt->gw_port, amt->relay_port,
724				   IPPROTO_UDP, 0,
725				   amt->stream_dev->ifindex);
726	if (IS_ERR(rt)) {
727		amt->dev->stats.tx_errors++;
728		goto out;
729	}
730
731	hlen = LL_RESERVED_SPACE(amt->dev);
732	tlen = amt->dev->needed_tailroom;
733	len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amtrh);
734	skb = netdev_alloc_skb_ip_align(amt->dev, len);
735	if (!skb) {
736		ip_rt_put(rt);
737		amt->dev->stats.tx_errors++;
738		goto out;
739	}
740
741	skb->priority = TC_PRIO_CONTROL;
742	skb_dst_set(skb, &rt->dst);
743
744	len = sizeof(*iph) + sizeof(*udph) + sizeof(*amtrh);
745	skb_reset_network_header(skb);
746	skb_put(skb, len);
747	amtrh = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
748	amtrh->version	 = 0;
749	amtrh->type	 = AMT_MSG_REQUEST;
750	amtrh->reserved1 = 0;
751	amtrh->p	 = v6;
752	amtrh->reserved2 = 0;
753	amtrh->nonce	 = amt->nonce;
754	skb_push(skb, sizeof(*udph));
755	skb_reset_transport_header(skb);
756	udph		= udp_hdr(skb);
757	udph->source	= amt->gw_port;
758	udph->dest	= amt->relay_port;
759	udph->len	= htons(sizeof(*amtrh) + sizeof(*udph));
760	udph->check	= 0;
761	offset = skb_transport_offset(skb);
762	skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
763	udph->check = csum_tcpudp_magic(amt->local_ip, amt->remote_ip,
764					sizeof(*udph) + sizeof(*amtrh),
765					IPPROTO_UDP, skb->csum);
766
767	skb_push(skb, sizeof(*iph));
768	iph		= ip_hdr(skb);
769	iph->version	= 4;
770	iph->ihl	= (sizeof(struct iphdr)) >> 2;
771	iph->tos	= AMT_TOS;
772	iph->frag_off	= 0;
773	iph->ttl	= ip4_dst_hoplimit(&rt->dst);
774	iph->daddr	= amt->remote_ip;
775	iph->saddr	= amt->local_ip;
776	iph->protocol	= IPPROTO_UDP;
777	iph->tot_len	= htons(len);
778
779	skb->ip_summed = CHECKSUM_NONE;
780	ip_select_ident(amt->net, skb, NULL);
781	ip_send_check(iph);
782	err = ip_local_out(amt->net, sock->sk, skb);
783	if (unlikely(net_xmit_eval(err)))
784		amt->dev->stats.tx_errors++;
785
786out:
787	rcu_read_unlock();
788}
789
790static void amt_send_igmp_gq(struct amt_dev *amt,
791			     struct amt_tunnel_list *tunnel)
792{
793	struct sk_buff *skb;
794
795	skb = amt_build_igmp_gq(amt);
796	if (!skb)
797		return;
798
799	amt_skb_cb(skb)->tunnel = tunnel;
800	dev_queue_xmit(skb);
801}
802
803#if IS_ENABLED(CONFIG_IPV6)
804static struct sk_buff *amt_build_mld_gq(struct amt_dev *amt)
805{
806	u8 ra[AMT_IP6HDR_OPTS] = { IPPROTO_ICMPV6, 0, IPV6_TLV_ROUTERALERT,
807				   2, 0, 0, IPV6_TLV_PAD1, IPV6_TLV_PAD1 };
808	int hlen = LL_RESERVED_SPACE(amt->dev);
809	int tlen = amt->dev->needed_tailroom;
810	struct mld2_query *mld2q;
811	void *csum_start = NULL;
812	struct ipv6hdr *ip6h;
813	struct sk_buff *skb;
814	struct ethhdr *eth;
815	u32 len;
816
817	len = hlen + tlen + sizeof(*ip6h) + sizeof(ra) + sizeof(*mld2q);
818	skb = netdev_alloc_skb_ip_align(amt->dev, len);
819	if (!skb)
820		return NULL;
821
822	skb_reserve(skb, hlen);
823	skb_push(skb, sizeof(*eth));
824	skb_reset_mac_header(skb);
825	eth = eth_hdr(skb);
826	skb->priority = TC_PRIO_CONTROL;
827	skb->protocol = htons(ETH_P_IPV6);
828	skb_put_zero(skb, sizeof(*ip6h));
829	skb_put_data(skb, ra, sizeof(ra));
830	skb_put_zero(skb, sizeof(*mld2q));
831	skb_pull(skb, sizeof(*eth));
832	skb_reset_network_header(skb);
833	ip6h			= ipv6_hdr(skb);
834	ip6h->payload_len	= htons(sizeof(ra) + sizeof(*mld2q));
835	ip6h->nexthdr		= NEXTHDR_HOP;
836	ip6h->hop_limit		= 1;
837	ip6h->daddr		= mld2_all_node;
838	ip6_flow_hdr(ip6h, 0, 0);
839
840	if (ipv6_dev_get_saddr(amt->net, amt->dev, &ip6h->daddr, 0,
841			       &ip6h->saddr)) {
842		amt->dev->stats.tx_errors++;
843		kfree_skb(skb);
844		return NULL;
845	}
846
847	eth->h_proto = htons(ETH_P_IPV6);
848	ether_addr_copy(eth->h_source, amt->dev->dev_addr);
849	ipv6_eth_mc_map(&mld2_all_node, eth->h_dest);
850
851	skb_pull(skb, sizeof(*ip6h) + sizeof(ra));
852	skb_reset_transport_header(skb);
853	mld2q			= (struct mld2_query *)icmp6_hdr(skb);
854	mld2q->mld2q_mrc	= htons(1);
855	mld2q->mld2q_type	= ICMPV6_MGM_QUERY;
856	mld2q->mld2q_code	= 0;
857	mld2q->mld2q_cksum	= 0;
858	mld2q->mld2q_resv1	= 0;
859	mld2q->mld2q_resv2	= 0;
860	mld2q->mld2q_suppress	= 0;
861	mld2q->mld2q_qrv	= amt->qrv;
862	mld2q->mld2q_nsrcs	= 0;
863	mld2q->mld2q_qqic	= amt->qi;
864	csum_start		= (void *)mld2q;
865	mld2q->mld2q_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
866					     sizeof(*mld2q),
867					     IPPROTO_ICMPV6,
868					     csum_partial(csum_start,
869							  sizeof(*mld2q), 0));
870
871	skb->ip_summed = CHECKSUM_NONE;
872	skb_push(skb, sizeof(*eth) + sizeof(*ip6h) + sizeof(ra));
873	return skb;
874}
875
876static void amt_send_mld_gq(struct amt_dev *amt, struct amt_tunnel_list *tunnel)
877{
878	struct sk_buff *skb;
879
880	skb = amt_build_mld_gq(amt);
881	if (!skb)
882		return;
883
884	amt_skb_cb(skb)->tunnel = tunnel;
885	dev_queue_xmit(skb);
886}
887#else
888static void amt_send_mld_gq(struct amt_dev *amt, struct amt_tunnel_list *tunnel)
889{
890}
891#endif
892
893static bool amt_queue_event(struct amt_dev *amt, enum amt_event event,
894			    struct sk_buff *skb)
895{
896	int index;
897
898	spin_lock_bh(&amt->lock);
899	if (amt->nr_events >= AMT_MAX_EVENTS) {
900		spin_unlock_bh(&amt->lock);
901		return 1;
902	}
903
904	index = (amt->event_idx + amt->nr_events) % AMT_MAX_EVENTS;
905	amt->events[index].event = event;
906	amt->events[index].skb = skb;
907	amt->nr_events++;
908	amt->event_idx %= AMT_MAX_EVENTS;
909	queue_work(amt_wq, &amt->event_wq);
910	spin_unlock_bh(&amt->lock);
911
912	return 0;
913}
914
915static void amt_secret_work(struct work_struct *work)
916{
917	struct amt_dev *amt = container_of(to_delayed_work(work),
918					   struct amt_dev,
919					   secret_wq);
920
921	spin_lock_bh(&amt->lock);
922	get_random_bytes(&amt->key, sizeof(siphash_key_t));
923	spin_unlock_bh(&amt->lock);
924	mod_delayed_work(amt_wq, &amt->secret_wq,
925			 msecs_to_jiffies(AMT_SECRET_TIMEOUT));
926}
927
928static void amt_event_send_discovery(struct amt_dev *amt)
929{
930	if (amt->status > AMT_STATUS_SENT_DISCOVERY)
931		goto out;
932	get_random_bytes(&amt->nonce, sizeof(__be32));
933
934	amt_send_discovery(amt);
935out:
936	mod_delayed_work(amt_wq, &amt->discovery_wq,
937			 msecs_to_jiffies(AMT_DISCOVERY_TIMEOUT));
938}
939
940static void amt_discovery_work(struct work_struct *work)
941{
942	struct amt_dev *amt = container_of(to_delayed_work(work),
943					   struct amt_dev,
944					   discovery_wq);
945
946	if (amt_queue_event(amt, AMT_EVENT_SEND_DISCOVERY, NULL))
947		mod_delayed_work(amt_wq, &amt->discovery_wq,
948				 msecs_to_jiffies(AMT_DISCOVERY_TIMEOUT));
949}
950
951static void amt_event_send_request(struct amt_dev *amt)
952{
953	u32 exp;
954
955	if (amt->status < AMT_STATUS_RECEIVED_ADVERTISEMENT)
956		goto out;
957
958	if (amt->req_cnt > AMT_MAX_REQ_COUNT) {
959		netdev_dbg(amt->dev, "Gateway is not ready");
960		amt->qi = AMT_INIT_REQ_TIMEOUT;
961		WRITE_ONCE(amt->ready4, false);
962		WRITE_ONCE(amt->ready6, false);
963		amt->remote_ip = 0;
964		amt_update_gw_status(amt, AMT_STATUS_INIT, false);
965		amt->req_cnt = 0;
966		amt->nonce = 0;
967		goto out;
968	}
969
970	if (!amt->req_cnt) {
971		WRITE_ONCE(amt->ready4, false);
972		WRITE_ONCE(amt->ready6, false);
973		get_random_bytes(&amt->nonce, sizeof(__be32));
974	}
975
976	amt_send_request(amt, false);
977	amt_send_request(amt, true);
978	amt_update_gw_status(amt, AMT_STATUS_SENT_REQUEST, true);
979	amt->req_cnt++;
980out:
981	exp = min_t(u32, (1 * (1 << amt->req_cnt)), AMT_MAX_REQ_TIMEOUT);
982	mod_delayed_work(amt_wq, &amt->req_wq, msecs_to_jiffies(exp * 1000));
983}
984
985static void amt_req_work(struct work_struct *work)
986{
987	struct amt_dev *amt = container_of(to_delayed_work(work),
988					   struct amt_dev,
989					   req_wq);
990
991	if (amt_queue_event(amt, AMT_EVENT_SEND_REQUEST, NULL))
992		mod_delayed_work(amt_wq, &amt->req_wq,
993				 msecs_to_jiffies(100));
994}
995
996static bool amt_send_membership_update(struct amt_dev *amt,
997				       struct sk_buff *skb,
998				       bool v6)
999{
1000	struct amt_header_membership_update *amtmu;
1001	struct socket *sock;
1002	struct iphdr *iph;
1003	struct flowi4 fl4;
1004	struct rtable *rt;
1005	int err;
1006
1007	sock = rcu_dereference_bh(amt->sock);
1008	if (!sock)
1009		return true;
1010
1011	err = skb_cow_head(skb, LL_RESERVED_SPACE(amt->dev) + sizeof(*amtmu) +
1012			   sizeof(*iph) + sizeof(struct udphdr));
1013	if (err)
1014		return true;
1015
1016	skb_reset_inner_headers(skb);
1017	memset(&fl4, 0, sizeof(struct flowi4));
1018	fl4.flowi4_oif         = amt->stream_dev->ifindex;
1019	fl4.daddr              = amt->remote_ip;
1020	fl4.saddr              = amt->local_ip;
1021	fl4.flowi4_tos         = AMT_TOS;
1022	fl4.flowi4_proto       = IPPROTO_UDP;
1023	rt = ip_route_output_key(amt->net, &fl4);
1024	if (IS_ERR(rt)) {
1025		netdev_dbg(amt->dev, "no route to %pI4\n", &amt->remote_ip);
1026		return true;
1027	}
1028
1029	amtmu			= skb_push(skb, sizeof(*amtmu));
1030	amtmu->version		= 0;
1031	amtmu->type		= AMT_MSG_MEMBERSHIP_UPDATE;
1032	amtmu->reserved		= 0;
1033	amtmu->nonce		= amt->nonce;
1034	amtmu->response_mac	= amt->mac;
1035
1036	if (!v6)
1037		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1038	else
1039		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1040	udp_tunnel_xmit_skb(rt, sock->sk, skb,
1041			    fl4.saddr,
1042			    fl4.daddr,
1043			    AMT_TOS,
1044			    ip4_dst_hoplimit(&rt->dst),
1045			    0,
1046			    amt->gw_port,
1047			    amt->relay_port,
1048			    false,
1049			    false);
1050	amt_update_gw_status(amt, AMT_STATUS_SENT_UPDATE, true);
1051	return false;
1052}
1053
1054static void amt_send_multicast_data(struct amt_dev *amt,
1055				    const struct sk_buff *oskb,
1056				    struct amt_tunnel_list *tunnel,
1057				    bool v6)
1058{
1059	struct amt_header_mcast_data *amtmd;
1060	struct socket *sock;
1061	struct sk_buff *skb;
1062	struct iphdr *iph;
1063	struct flowi4 fl4;
1064	struct rtable *rt;
1065
1066	sock = rcu_dereference_bh(amt->sock);
1067	if (!sock)
1068		return;
1069
1070	skb = skb_copy_expand(oskb, sizeof(*amtmd) + sizeof(*iph) +
1071			      sizeof(struct udphdr), 0, GFP_ATOMIC);
1072	if (!skb)
1073		return;
1074
1075	skb_reset_inner_headers(skb);
1076	memset(&fl4, 0, sizeof(struct flowi4));
1077	fl4.flowi4_oif         = amt->stream_dev->ifindex;
1078	fl4.daddr              = tunnel->ip4;
1079	fl4.saddr              = amt->local_ip;
1080	fl4.flowi4_proto       = IPPROTO_UDP;
1081	rt = ip_route_output_key(amt->net, &fl4);
1082	if (IS_ERR(rt)) {
1083		netdev_dbg(amt->dev, "no route to %pI4\n", &tunnel->ip4);
1084		kfree_skb(skb);
1085		return;
1086	}
1087
1088	amtmd = skb_push(skb, sizeof(*amtmd));
1089	amtmd->version = 0;
1090	amtmd->reserved = 0;
1091	amtmd->type = AMT_MSG_MULTICAST_DATA;
1092
1093	if (!v6)
1094		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1095	else
1096		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1097	udp_tunnel_xmit_skb(rt, sock->sk, skb,
1098			    fl4.saddr,
1099			    fl4.daddr,
1100			    AMT_TOS,
1101			    ip4_dst_hoplimit(&rt->dst),
1102			    0,
1103			    amt->relay_port,
1104			    tunnel->source_port,
1105			    false,
1106			    false);
1107}
1108
1109static bool amt_send_membership_query(struct amt_dev *amt,
1110				      struct sk_buff *skb,
1111				      struct amt_tunnel_list *tunnel,
1112				      bool v6)
1113{
1114	struct amt_header_membership_query *amtmq;
1115	struct socket *sock;
1116	struct rtable *rt;
1117	struct flowi4 fl4;
1118	int err;
1119
1120	sock = rcu_dereference_bh(amt->sock);
1121	if (!sock)
1122		return true;
1123
1124	err = skb_cow_head(skb, LL_RESERVED_SPACE(amt->dev) + sizeof(*amtmq) +
1125			   sizeof(struct iphdr) + sizeof(struct udphdr));
1126	if (err)
1127		return true;
1128
1129	skb_reset_inner_headers(skb);
1130	memset(&fl4, 0, sizeof(struct flowi4));
1131	fl4.flowi4_oif         = amt->stream_dev->ifindex;
1132	fl4.daddr              = tunnel->ip4;
1133	fl4.saddr              = amt->local_ip;
1134	fl4.flowi4_tos         = AMT_TOS;
1135	fl4.flowi4_proto       = IPPROTO_UDP;
1136	rt = ip_route_output_key(amt->net, &fl4);
1137	if (IS_ERR(rt)) {
1138		netdev_dbg(amt->dev, "no route to %pI4\n", &tunnel->ip4);
1139		return true;
1140	}
1141
1142	amtmq		= skb_push(skb, sizeof(*amtmq));
1143	amtmq->version	= 0;
1144	amtmq->type	= AMT_MSG_MEMBERSHIP_QUERY;
1145	amtmq->reserved = 0;
1146	amtmq->l	= 0;
1147	amtmq->g	= 0;
1148	amtmq->nonce	= tunnel->nonce;
1149	amtmq->response_mac = tunnel->mac;
1150
1151	if (!v6)
1152		skb_set_inner_protocol(skb, htons(ETH_P_IP));
1153	else
1154		skb_set_inner_protocol(skb, htons(ETH_P_IPV6));
1155	udp_tunnel_xmit_skb(rt, sock->sk, skb,
1156			    fl4.saddr,
1157			    fl4.daddr,
1158			    AMT_TOS,
1159			    ip4_dst_hoplimit(&rt->dst),
1160			    0,
1161			    amt->relay_port,
1162			    tunnel->source_port,
1163			    false,
1164			    false);
1165	amt_update_relay_status(tunnel, AMT_STATUS_SENT_QUERY, true);
1166	return false;
1167}
1168
1169static netdev_tx_t amt_dev_xmit(struct sk_buff *skb, struct net_device *dev)
1170{
1171	struct amt_dev *amt = netdev_priv(dev);
1172	struct amt_tunnel_list *tunnel;
1173	struct amt_group_node *gnode;
1174	union amt_addr group = {0,};
1175#if IS_ENABLED(CONFIG_IPV6)
1176	struct ipv6hdr *ip6h;
1177	struct mld_msg *mld;
1178#endif
1179	bool report = false;
1180	struct igmphdr *ih;
1181	bool query = false;
1182	struct iphdr *iph;
1183	bool data = false;
1184	bool v6 = false;
1185	u32 hash;
1186
1187	iph = ip_hdr(skb);
1188	if (iph->version == 4) {
1189		if (!ipv4_is_multicast(iph->daddr))
1190			goto free;
1191
1192		if (!ip_mc_check_igmp(skb)) {
1193			ih = igmp_hdr(skb);
1194			switch (ih->type) {
1195			case IGMPV3_HOST_MEMBERSHIP_REPORT:
1196			case IGMP_HOST_MEMBERSHIP_REPORT:
1197				report = true;
1198				break;
1199			case IGMP_HOST_MEMBERSHIP_QUERY:
1200				query = true;
1201				break;
1202			default:
1203				goto free;
1204			}
1205		} else {
1206			data = true;
1207		}
1208		v6 = false;
1209		group.ip4 = iph->daddr;
1210#if IS_ENABLED(CONFIG_IPV6)
1211	} else if (iph->version == 6) {
1212		ip6h = ipv6_hdr(skb);
1213		if (!ipv6_addr_is_multicast(&ip6h->daddr))
1214			goto free;
1215
1216		if (!ipv6_mc_check_mld(skb)) {
1217			mld = (struct mld_msg *)skb_transport_header(skb);
1218			switch (mld->mld_type) {
1219			case ICMPV6_MGM_REPORT:
1220			case ICMPV6_MLD2_REPORT:
1221				report = true;
1222				break;
1223			case ICMPV6_MGM_QUERY:
1224				query = true;
1225				break;
1226			default:
1227				goto free;
1228			}
1229		} else {
1230			data = true;
1231		}
1232		v6 = true;
1233		group.ip6 = ip6h->daddr;
1234#endif
1235	} else {
1236		dev->stats.tx_errors++;
1237		goto free;
1238	}
1239
1240	if (!pskb_may_pull(skb, sizeof(struct ethhdr)))
1241		goto free;
1242
1243	skb_pull(skb, sizeof(struct ethhdr));
1244
1245	if (amt->mode == AMT_MODE_GATEWAY) {
1246		/* Gateway only passes IGMP/MLD packets */
1247		if (!report)
1248			goto free;
1249		if ((!v6 && !READ_ONCE(amt->ready4)) ||
1250		    (v6 && !READ_ONCE(amt->ready6)))
1251			goto free;
1252		if (amt_send_membership_update(amt, skb,  v6))
1253			goto free;
1254		goto unlock;
1255	} else if (amt->mode == AMT_MODE_RELAY) {
1256		if (query) {
1257			tunnel = amt_skb_cb(skb)->tunnel;
1258			if (!tunnel) {
1259				WARN_ON(1);
1260				goto free;
1261			}
1262
1263			/* Do not forward unexpected query */
1264			if (amt_send_membership_query(amt, skb, tunnel, v6))
1265				goto free;
1266			goto unlock;
1267		}
1268
1269		if (!data)
1270			goto free;
1271		list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list) {
1272			hash = amt_group_hash(tunnel, &group);
1273			hlist_for_each_entry_rcu(gnode, &tunnel->groups[hash],
1274						 node) {
1275				if (!v6) {
1276					if (gnode->group_addr.ip4 == iph->daddr)
1277						goto found;
1278#if IS_ENABLED(CONFIG_IPV6)
1279				} else {
1280					if (ipv6_addr_equal(&gnode->group_addr.ip6,
1281							    &ip6h->daddr))
1282						goto found;
1283#endif
1284				}
1285			}
1286			continue;
1287found:
1288			amt_send_multicast_data(amt, skb, tunnel, v6);
1289		}
1290	}
1291
1292	dev_kfree_skb(skb);
1293	return NETDEV_TX_OK;
1294free:
1295	dev_kfree_skb(skb);
1296unlock:
1297	dev->stats.tx_dropped++;
1298	return NETDEV_TX_OK;
1299}
1300
1301static int amt_parse_type(struct sk_buff *skb)
1302{
1303	struct amt_header *amth;
1304
1305	if (!pskb_may_pull(skb, sizeof(struct udphdr) +
1306			   sizeof(struct amt_header)))
1307		return -1;
1308
1309	amth = (struct amt_header *)(udp_hdr(skb) + 1);
1310
1311	if (amth->version != 0)
1312		return -1;
1313
1314	if (amth->type >= __AMT_MSG_MAX || !amth->type)
1315		return -1;
1316	return amth->type;
1317}
1318
1319static void amt_clear_groups(struct amt_tunnel_list *tunnel)
1320{
1321	struct amt_dev *amt = tunnel->amt;
1322	struct amt_group_node *gnode;
1323	struct hlist_node *t;
1324	int i;
1325
1326	spin_lock_bh(&tunnel->lock);
1327	rcu_read_lock();
1328	for (i = 0; i < amt->hash_buckets; i++)
1329		hlist_for_each_entry_safe(gnode, t, &tunnel->groups[i], node)
1330			amt_del_group(amt, gnode);
1331	rcu_read_unlock();
1332	spin_unlock_bh(&tunnel->lock);
1333}
1334
1335static void amt_tunnel_expire(struct work_struct *work)
1336{
1337	struct amt_tunnel_list *tunnel = container_of(to_delayed_work(work),
1338						      struct amt_tunnel_list,
1339						      gc_wq);
1340	struct amt_dev *amt = tunnel->amt;
1341
1342	spin_lock_bh(&amt->lock);
1343	rcu_read_lock();
1344	list_del_rcu(&tunnel->list);
1345	amt->nr_tunnels--;
1346	amt_clear_groups(tunnel);
1347	rcu_read_unlock();
1348	spin_unlock_bh(&amt->lock);
1349	kfree_rcu(tunnel, rcu);
1350}
1351
1352static void amt_cleanup_srcs(struct amt_dev *amt,
1353			     struct amt_tunnel_list *tunnel,
1354			     struct amt_group_node *gnode)
1355{
1356	struct amt_source_node *snode;
1357	struct hlist_node *t;
1358	int i;
1359
1360	/* Delete old sources */
1361	for (i = 0; i < amt->hash_buckets; i++) {
1362		hlist_for_each_entry_safe(snode, t, &gnode->sources[i], node) {
1363			if (snode->flags == AMT_SOURCE_OLD)
1364				amt_destroy_source(snode);
1365		}
1366	}
1367
1368	/* switch from new to old */
1369	for (i = 0; i < amt->hash_buckets; i++)  {
1370		hlist_for_each_entry_rcu(snode, &gnode->sources[i], node) {
1371			snode->flags = AMT_SOURCE_OLD;
1372			if (!gnode->v6)
1373				netdev_dbg(snode->gnode->amt->dev,
1374					   "Add source as OLD %pI4 from %pI4\n",
1375					   &snode->source_addr.ip4,
1376					   &gnode->group_addr.ip4);
1377#if IS_ENABLED(CONFIG_IPV6)
1378			else
1379				netdev_dbg(snode->gnode->amt->dev,
1380					   "Add source as OLD %pI6 from %pI6\n",
1381					   &snode->source_addr.ip6,
1382					   &gnode->group_addr.ip6);
1383#endif
1384		}
1385	}
1386}
1387
1388static void amt_add_srcs(struct amt_dev *amt, struct amt_tunnel_list *tunnel,
1389			 struct amt_group_node *gnode, void *grec,
1390			 bool v6)
1391{
1392	struct igmpv3_grec *igmp_grec;
1393	struct amt_source_node *snode;
1394#if IS_ENABLED(CONFIG_IPV6)
1395	struct mld2_grec *mld_grec;
1396#endif
1397	union amt_addr src = {0,};
1398	u16 nsrcs;
1399	u32 hash;
1400	int i;
1401
1402	if (!v6) {
1403		igmp_grec = grec;
1404		nsrcs = ntohs(igmp_grec->grec_nsrcs);
1405	} else {
1406#if IS_ENABLED(CONFIG_IPV6)
1407		mld_grec = grec;
1408		nsrcs = ntohs(mld_grec->grec_nsrcs);
1409#else
1410	return;
1411#endif
1412	}
1413	for (i = 0; i < nsrcs; i++) {
1414		if (tunnel->nr_sources >= amt->max_sources)
1415			return;
1416		if (!v6)
1417			src.ip4 = igmp_grec->grec_src[i];
1418#if IS_ENABLED(CONFIG_IPV6)
1419		else
1420			memcpy(&src.ip6, &mld_grec->grec_src[i],
1421			       sizeof(struct in6_addr));
1422#endif
1423		if (amt_lookup_src(tunnel, gnode, AMT_FILTER_ALL, &src))
1424			continue;
1425
1426		snode = amt_alloc_snode(gnode, &src);
1427		if (snode) {
1428			hash = amt_source_hash(tunnel, &snode->source_addr);
1429			hlist_add_head_rcu(&snode->node, &gnode->sources[hash]);
1430			tunnel->nr_sources++;
1431			gnode->nr_sources++;
1432
1433			if (!gnode->v6)
1434				netdev_dbg(snode->gnode->amt->dev,
1435					   "Add source as NEW %pI4 from %pI4\n",
1436					   &snode->source_addr.ip4,
1437					   &gnode->group_addr.ip4);
1438#if IS_ENABLED(CONFIG_IPV6)
1439			else
1440				netdev_dbg(snode->gnode->amt->dev,
1441					   "Add source as NEW %pI6 from %pI6\n",
1442					   &snode->source_addr.ip6,
1443					   &gnode->group_addr.ip6);
1444#endif
1445		}
1446	}
1447}
1448
1449/* Router State   Report Rec'd New Router State
1450 * ------------   ------------ ----------------
1451 * EXCLUDE (X,Y)  IS_IN (A)    EXCLUDE (X+A,Y-A)
1452 *
1453 * -----------+-----------+-----------+
1454 *            |    OLD    |    NEW    |
1455 * -----------+-----------+-----------+
1456 *    FWD     |     X     |    X+A    |
1457 * -----------+-----------+-----------+
1458 *    D_FWD   |     Y     |    Y-A    |
1459 * -----------+-----------+-----------+
1460 *    NONE    |           |     A     |
1461 * -----------+-----------+-----------+
1462 *
1463 * a) Received sources are NONE/NEW
1464 * b) All NONE will be deleted by amt_cleanup_srcs().
1465 * c) All OLD will be deleted by amt_cleanup_srcs().
1466 * d) After delete, NEW source will be switched to OLD.
1467 */
1468static void amt_lookup_act_srcs(struct amt_tunnel_list *tunnel,
1469				struct amt_group_node *gnode,
1470				void *grec,
1471				enum amt_ops ops,
1472				enum amt_filter filter,
1473				enum amt_act act,
1474				bool v6)
1475{
1476	struct amt_dev *amt = tunnel->amt;
1477	struct amt_source_node *snode;
1478	struct igmpv3_grec *igmp_grec;
1479#if IS_ENABLED(CONFIG_IPV6)
1480	struct mld2_grec *mld_grec;
1481#endif
1482	union amt_addr src = {0,};
1483	struct hlist_node *t;
1484	u16 nsrcs;
1485	int i, j;
1486
1487	if (!v6) {
1488		igmp_grec = grec;
1489		nsrcs = ntohs(igmp_grec->grec_nsrcs);
1490	} else {
1491#if IS_ENABLED(CONFIG_IPV6)
1492		mld_grec = grec;
1493		nsrcs = ntohs(mld_grec->grec_nsrcs);
1494#else
1495	return;
1496#endif
1497	}
1498
1499	memset(&src, 0, sizeof(union amt_addr));
1500	switch (ops) {
1501	case AMT_OPS_INT:
1502		/* A*B */
1503		for (i = 0; i < nsrcs; i++) {
1504			if (!v6)
1505				src.ip4 = igmp_grec->grec_src[i];
1506#if IS_ENABLED(CONFIG_IPV6)
1507			else
1508				memcpy(&src.ip6, &mld_grec->grec_src[i],
1509				       sizeof(struct in6_addr));
1510#endif
1511			snode = amt_lookup_src(tunnel, gnode, filter, &src);
1512			if (!snode)
1513				continue;
1514			amt_act_src(tunnel, gnode, snode, act);
1515		}
1516		break;
1517	case AMT_OPS_UNI:
1518		/* A+B */
1519		for (i = 0; i < amt->hash_buckets; i++) {
1520			hlist_for_each_entry_safe(snode, t, &gnode->sources[i],
1521						  node) {
1522				if (amt_status_filter(snode, filter))
1523					amt_act_src(tunnel, gnode, snode, act);
1524			}
1525		}
1526		for (i = 0; i < nsrcs; i++) {
1527			if (!v6)
1528				src.ip4 = igmp_grec->grec_src[i];
1529#if IS_ENABLED(CONFIG_IPV6)
1530			else
1531				memcpy(&src.ip6, &mld_grec->grec_src[i],
1532				       sizeof(struct in6_addr));
1533#endif
1534			snode = amt_lookup_src(tunnel, gnode, filter, &src);
1535			if (!snode)
1536				continue;
1537			amt_act_src(tunnel, gnode, snode, act);
1538		}
1539		break;
1540	case AMT_OPS_SUB:
1541		/* A-B */
1542		for (i = 0; i < amt->hash_buckets; i++) {
1543			hlist_for_each_entry_safe(snode, t, &gnode->sources[i],
1544						  node) {
1545				if (!amt_status_filter(snode, filter))
1546					continue;
1547				for (j = 0; j < nsrcs; j++) {
1548					if (!v6)
1549						src.ip4 = igmp_grec->grec_src[j];
1550#if IS_ENABLED(CONFIG_IPV6)
1551					else
1552						memcpy(&src.ip6,
1553						       &mld_grec->grec_src[j],
1554						       sizeof(struct in6_addr));
1555#endif
1556					if (amt_addr_equal(&snode->source_addr,
1557							   &src))
1558						goto out_sub;
1559				}
1560				amt_act_src(tunnel, gnode, snode, act);
1561				continue;
1562out_sub:;
1563			}
1564		}
1565		break;
1566	case AMT_OPS_SUB_REV:
1567		/* B-A */
1568		for (i = 0; i < nsrcs; i++) {
1569			if (!v6)
1570				src.ip4 = igmp_grec->grec_src[i];
1571#if IS_ENABLED(CONFIG_IPV6)
1572			else
1573				memcpy(&src.ip6, &mld_grec->grec_src[i],
1574				       sizeof(struct in6_addr));
1575#endif
1576			snode = amt_lookup_src(tunnel, gnode, AMT_FILTER_ALL,
1577					       &src);
1578			if (!snode) {
1579				snode = amt_lookup_src(tunnel, gnode,
1580						       filter, &src);
1581				if (snode)
1582					amt_act_src(tunnel, gnode, snode, act);
1583			}
1584		}
1585		break;
1586	default:
1587		netdev_dbg(amt->dev, "Invalid type\n");
1588		return;
1589	}
1590}
1591
1592static void amt_mcast_is_in_handler(struct amt_dev *amt,
1593				    struct amt_tunnel_list *tunnel,
1594				    struct amt_group_node *gnode,
1595				    void *grec, void *zero_grec, bool v6)
1596{
1597	if (gnode->filter_mode == MCAST_INCLUDE) {
1598/* Router State   Report Rec'd New Router State        Actions
1599 * ------------   ------------ ----------------        -------
1600 * INCLUDE (A)    IS_IN (B)    INCLUDE (A+B)           (B)=GMI
1601 */
1602		/* Update IS_IN (B) as FWD/NEW */
1603		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1604				    AMT_FILTER_NONE_NEW,
1605				    AMT_ACT_STATUS_FWD_NEW,
1606				    v6);
1607		/* Update INCLUDE (A) as NEW */
1608		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1609				    AMT_FILTER_FWD,
1610				    AMT_ACT_STATUS_FWD_NEW,
1611				    v6);
1612		/* (B)=GMI */
1613		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1614				    AMT_FILTER_FWD_NEW,
1615				    AMT_ACT_GMI,
1616				    v6);
1617	} else {
1618/* State        Actions
1619 * ------------   ------------ ----------------        -------
1620 * EXCLUDE (X,Y)  IS_IN (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1621 */
1622		/* Update (A) in (X, Y) as NONE/NEW */
1623		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1624				    AMT_FILTER_BOTH,
1625				    AMT_ACT_STATUS_NONE_NEW,
1626				    v6);
1627		/* Update FWD/OLD as FWD/NEW */
1628		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1629				    AMT_FILTER_FWD,
1630				    AMT_ACT_STATUS_FWD_NEW,
1631				    v6);
1632		/* Update IS_IN (A) as FWD/NEW */
1633		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1634				    AMT_FILTER_NONE_NEW,
1635				    AMT_ACT_STATUS_FWD_NEW,
1636				    v6);
1637		/* Update EXCLUDE (, Y-A) as D_FWD_NEW */
1638		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB,
1639				    AMT_FILTER_D_FWD,
1640				    AMT_ACT_STATUS_D_FWD_NEW,
1641				    v6);
1642	}
1643}
1644
1645static void amt_mcast_is_ex_handler(struct amt_dev *amt,
1646				    struct amt_tunnel_list *tunnel,
1647				    struct amt_group_node *gnode,
1648				    void *grec, void *zero_grec, bool v6)
1649{
1650	if (gnode->filter_mode == MCAST_INCLUDE) {
1651/* Router State   Report Rec'd  New Router State         Actions
1652 * ------------   ------------  ----------------         -------
1653 * INCLUDE (A)    IS_EX (B)     EXCLUDE (A*B,B-A)        (B-A)=0
1654 *                                                       Delete (A-B)
1655 *                                                       Group Timer=GMI
1656 */
1657		/* EXCLUDE(A*B, ) */
1658		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1659				    AMT_FILTER_FWD,
1660				    AMT_ACT_STATUS_FWD_NEW,
1661				    v6);
1662		/* EXCLUDE(, B-A) */
1663		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1664				    AMT_FILTER_FWD,
1665				    AMT_ACT_STATUS_D_FWD_NEW,
1666				    v6);
1667		/* (B-A)=0 */
1668		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1669				    AMT_FILTER_D_FWD_NEW,
1670				    AMT_ACT_GMI_ZERO,
1671				    v6);
1672		/* Group Timer=GMI */
1673		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1674				      msecs_to_jiffies(amt_gmi(amt))))
1675			dev_hold(amt->dev);
1676		gnode->filter_mode = MCAST_EXCLUDE;
1677		/* Delete (A-B) will be worked by amt_cleanup_srcs(). */
1678	} else {
1679/* Router State   Report Rec'd  New Router State	Actions
1680 * ------------   ------------  ----------------	-------
1681 * EXCLUDE (X,Y)  IS_EX (A)     EXCLUDE (A-Y,Y*A)	(A-X-Y)=GMI
1682 *							Delete (X-A)
1683 *							Delete (Y-A)
1684 *							Group Timer=GMI
1685 */
1686		/* EXCLUDE (A-Y, ) */
1687		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1688				    AMT_FILTER_D_FWD,
1689				    AMT_ACT_STATUS_FWD_NEW,
1690				    v6);
1691		/* EXCLUDE (, Y*A ) */
1692		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1693				    AMT_FILTER_D_FWD,
1694				    AMT_ACT_STATUS_D_FWD_NEW,
1695				    v6);
1696		/* (A-X-Y)=GMI */
1697		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1698				    AMT_FILTER_BOTH_NEW,
1699				    AMT_ACT_GMI,
1700				    v6);
1701		/* Group Timer=GMI */
1702		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1703				      msecs_to_jiffies(amt_gmi(amt))))
1704			dev_hold(amt->dev);
1705		/* Delete (X-A), (Y-A) will be worked by amt_cleanup_srcs(). */
1706	}
1707}
1708
1709static void amt_mcast_to_in_handler(struct amt_dev *amt,
1710				    struct amt_tunnel_list *tunnel,
1711				    struct amt_group_node *gnode,
1712				    void *grec, void *zero_grec, bool v6)
1713{
1714	if (gnode->filter_mode == MCAST_INCLUDE) {
1715/* Router State   Report Rec'd New Router State        Actions
1716 * ------------   ------------ ----------------        -------
1717 * INCLUDE (A)    TO_IN (B)    INCLUDE (A+B)           (B)=GMI
1718 *						       Send Q(G,A-B)
1719 */
1720		/* Update TO_IN (B) sources as FWD/NEW */
1721		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1722				    AMT_FILTER_NONE_NEW,
1723				    AMT_ACT_STATUS_FWD_NEW,
1724				    v6);
1725		/* Update INCLUDE (A) sources as NEW */
1726		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1727				    AMT_FILTER_FWD,
1728				    AMT_ACT_STATUS_FWD_NEW,
1729				    v6);
1730		/* (B)=GMI */
1731		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1732				    AMT_FILTER_FWD_NEW,
1733				    AMT_ACT_GMI,
1734				    v6);
1735	} else {
1736/* Router State   Report Rec'd New Router State        Actions
1737 * ------------   ------------ ----------------        -------
1738 * EXCLUDE (X,Y)  TO_IN (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1739 *						       Send Q(G,X-A)
1740 *						       Send Q(G)
1741 */
1742		/* Update TO_IN (A) sources as FWD/NEW */
1743		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1744				    AMT_FILTER_NONE_NEW,
1745				    AMT_ACT_STATUS_FWD_NEW,
1746				    v6);
1747		/* Update EXCLUDE(X,) sources as FWD/NEW */
1748		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1749				    AMT_FILTER_FWD,
1750				    AMT_ACT_STATUS_FWD_NEW,
1751				    v6);
1752		/* EXCLUDE (, Y-A)
1753		 * (A) are already switched to FWD_NEW.
1754		 * So, D_FWD/OLD -> D_FWD/NEW is okay.
1755		 */
1756		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1757				    AMT_FILTER_D_FWD,
1758				    AMT_ACT_STATUS_D_FWD_NEW,
1759				    v6);
1760		/* (A)=GMI
1761		 * Only FWD_NEW will have (A) sources.
1762		 */
1763		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1764				    AMT_FILTER_FWD_NEW,
1765				    AMT_ACT_GMI,
1766				    v6);
1767	}
1768}
1769
1770static void amt_mcast_to_ex_handler(struct amt_dev *amt,
1771				    struct amt_tunnel_list *tunnel,
1772				    struct amt_group_node *gnode,
1773				    void *grec, void *zero_grec, bool v6)
1774{
1775	if (gnode->filter_mode == MCAST_INCLUDE) {
1776/* Router State   Report Rec'd New Router State        Actions
1777 * ------------   ------------ ----------------        -------
1778 * INCLUDE (A)    TO_EX (B)    EXCLUDE (A*B,B-A)       (B-A)=0
1779 *						       Delete (A-B)
1780 *						       Send Q(G,A*B)
1781 *						       Group Timer=GMI
1782 */
1783		/* EXCLUDE (A*B, ) */
1784		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1785				    AMT_FILTER_FWD,
1786				    AMT_ACT_STATUS_FWD_NEW,
1787				    v6);
1788		/* EXCLUDE (, B-A) */
1789		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1790				    AMT_FILTER_FWD,
1791				    AMT_ACT_STATUS_D_FWD_NEW,
1792				    v6);
1793		/* (B-A)=0 */
1794		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1795				    AMT_FILTER_D_FWD_NEW,
1796				    AMT_ACT_GMI_ZERO,
1797				    v6);
1798		/* Group Timer=GMI */
1799		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1800				      msecs_to_jiffies(amt_gmi(amt))))
1801			dev_hold(amt->dev);
1802		gnode->filter_mode = MCAST_EXCLUDE;
1803		/* Delete (A-B) will be worked by amt_cleanup_srcs(). */
1804	} else {
1805/* Router State   Report Rec'd New Router State        Actions
1806 * ------------   ------------ ----------------        -------
1807 * EXCLUDE (X,Y)  TO_EX (A)    EXCLUDE (A-Y,Y*A)       (A-X-Y)=Group Timer
1808 *						       Delete (X-A)
1809 *						       Delete (Y-A)
1810 *						       Send Q(G,A-Y)
1811 *						       Group Timer=GMI
1812 */
1813		/* Update (A-X-Y) as NONE/OLD */
1814		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1815				    AMT_FILTER_BOTH,
1816				    AMT_ACT_GT,
1817				    v6);
1818		/* EXCLUDE (A-Y, ) */
1819		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1820				    AMT_FILTER_D_FWD,
1821				    AMT_ACT_STATUS_FWD_NEW,
1822				    v6);
1823		/* EXCLUDE (, Y*A) */
1824		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1825				    AMT_FILTER_D_FWD,
1826				    AMT_ACT_STATUS_D_FWD_NEW,
1827				    v6);
1828		/* Group Timer=GMI */
1829		if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1830				      msecs_to_jiffies(amt_gmi(amt))))
1831			dev_hold(amt->dev);
1832		/* Delete (X-A), (Y-A) will be worked by amt_cleanup_srcs(). */
1833	}
1834}
1835
1836static void amt_mcast_allow_handler(struct amt_dev *amt,
1837				    struct amt_tunnel_list *tunnel,
1838				    struct amt_group_node *gnode,
1839				    void *grec, void *zero_grec, bool v6)
1840{
1841	if (gnode->filter_mode == MCAST_INCLUDE) {
1842/* Router State   Report Rec'd New Router State        Actions
1843 * ------------   ------------ ----------------        -------
1844 * INCLUDE (A)    ALLOW (B)    INCLUDE (A+B)	       (B)=GMI
1845 */
1846		/* INCLUDE (A+B) */
1847		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1848				    AMT_FILTER_FWD,
1849				    AMT_ACT_STATUS_FWD_NEW,
1850				    v6);
1851		/* (B)=GMI */
1852		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1853				    AMT_FILTER_FWD_NEW,
1854				    AMT_ACT_GMI,
1855				    v6);
1856	} else {
1857/* Router State   Report Rec'd New Router State        Actions
1858 * ------------   ------------ ----------------        -------
1859 * EXCLUDE (X,Y)  ALLOW (A)    EXCLUDE (X+A,Y-A)       (A)=GMI
1860 */
1861		/* EXCLUDE (X+A, ) */
1862		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1863				    AMT_FILTER_FWD,
1864				    AMT_ACT_STATUS_FWD_NEW,
1865				    v6);
1866		/* EXCLUDE (, Y-A) */
1867		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB,
1868				    AMT_FILTER_D_FWD,
1869				    AMT_ACT_STATUS_D_FWD_NEW,
1870				    v6);
1871		/* (A)=GMI
1872		 * All (A) source are now FWD/NEW status.
1873		 */
1874		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_INT,
1875				    AMT_FILTER_FWD_NEW,
1876				    AMT_ACT_GMI,
1877				    v6);
1878	}
1879}
1880
1881static void amt_mcast_block_handler(struct amt_dev *amt,
1882				    struct amt_tunnel_list *tunnel,
1883				    struct amt_group_node *gnode,
1884				    void *grec, void *zero_grec, bool v6)
1885{
1886	if (gnode->filter_mode == MCAST_INCLUDE) {
1887/* Router State   Report Rec'd New Router State        Actions
1888 * ------------   ------------ ----------------        -------
1889 * INCLUDE (A)    BLOCK (B)    INCLUDE (A)             Send Q(G,A*B)
1890 */
1891		/* INCLUDE (A) */
1892		amt_lookup_act_srcs(tunnel, gnode, zero_grec, AMT_OPS_UNI,
1893				    AMT_FILTER_FWD,
1894				    AMT_ACT_STATUS_FWD_NEW,
1895				    v6);
1896	} else {
1897/* Router State   Report Rec'd New Router State        Actions
1898 * ------------   ------------ ----------------        -------
1899 * EXCLUDE (X,Y)  BLOCK (A)    EXCLUDE (X+(A-Y),Y)     (A-X-Y)=Group Timer
1900 *						       Send Q(G,A-Y)
1901 */
1902		/* (A-X-Y)=Group Timer */
1903		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1904				    AMT_FILTER_BOTH,
1905				    AMT_ACT_GT,
1906				    v6);
1907		/* EXCLUDE (X, ) */
1908		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1909				    AMT_FILTER_FWD,
1910				    AMT_ACT_STATUS_FWD_NEW,
1911				    v6);
1912		/* EXCLUDE (X+(A-Y) */
1913		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_SUB_REV,
1914				    AMT_FILTER_D_FWD,
1915				    AMT_ACT_STATUS_FWD_NEW,
1916				    v6);
1917		/* EXCLUDE (, Y) */
1918		amt_lookup_act_srcs(tunnel, gnode, grec, AMT_OPS_UNI,
1919				    AMT_FILTER_D_FWD,
1920				    AMT_ACT_STATUS_D_FWD_NEW,
1921				    v6);
1922	}
1923}
1924
1925/* RFC 3376
1926 * 7.3.2. In the Presence of Older Version Group Members
1927 *
1928 * When Group Compatibility Mode is IGMPv2, a router internally
1929 * translates the following IGMPv2 messages for that group to their
1930 * IGMPv3 equivalents:
1931 *
1932 * IGMPv2 Message                IGMPv3 Equivalent
1933 * --------------                -----------------
1934 * Report                        IS_EX( {} )
1935 * Leave                         TO_IN( {} )
1936 */
1937static void amt_igmpv2_report_handler(struct amt_dev *amt, struct sk_buff *skb,
1938				      struct amt_tunnel_list *tunnel)
1939{
1940	struct igmphdr *ih = igmp_hdr(skb);
1941	struct iphdr *iph = ip_hdr(skb);
1942	struct amt_group_node *gnode;
1943	union amt_addr group, host;
1944
1945	memset(&group, 0, sizeof(union amt_addr));
1946	group.ip4 = ih->group;
1947	memset(&host, 0, sizeof(union amt_addr));
1948	host.ip4 = iph->saddr;
1949
1950	gnode = amt_lookup_group(tunnel, &group, &host, false);
1951	if (!gnode) {
1952		gnode = amt_add_group(amt, tunnel, &group, &host, false);
1953		if (!IS_ERR(gnode)) {
1954			gnode->filter_mode = MCAST_EXCLUDE;
1955			if (!mod_delayed_work(amt_wq, &gnode->group_timer,
1956					      msecs_to_jiffies(amt_gmi(amt))))
1957				dev_hold(amt->dev);
1958		}
1959	}
1960}
1961
1962/* RFC 3376
1963 * 7.3.2. In the Presence of Older Version Group Members
1964 *
1965 * When Group Compatibility Mode is IGMPv2, a router internally
1966 * translates the following IGMPv2 messages for that group to their
1967 * IGMPv3 equivalents:
1968 *
1969 * IGMPv2 Message                IGMPv3 Equivalent
1970 * --------------                -----------------
1971 * Report                        IS_EX( {} )
1972 * Leave                         TO_IN( {} )
1973 */
1974static void amt_igmpv2_leave_handler(struct amt_dev *amt, struct sk_buff *skb,
1975				     struct amt_tunnel_list *tunnel)
1976{
1977	struct igmphdr *ih = igmp_hdr(skb);
1978	struct iphdr *iph = ip_hdr(skb);
1979	struct amt_group_node *gnode;
1980	union amt_addr group, host;
1981
1982	memset(&group, 0, sizeof(union amt_addr));
1983	group.ip4 = ih->group;
1984	memset(&host, 0, sizeof(union amt_addr));
1985	host.ip4 = iph->saddr;
1986
1987	gnode = amt_lookup_group(tunnel, &group, &host, false);
1988	if (gnode)
1989		amt_del_group(amt, gnode);
1990}
1991
1992static void amt_igmpv3_report_handler(struct amt_dev *amt, struct sk_buff *skb,
1993				      struct amt_tunnel_list *tunnel)
1994{
1995	struct igmpv3_report *ihrv3 = igmpv3_report_hdr(skb);
1996	int len = skb_transport_offset(skb) + sizeof(*ihrv3);
1997	void *zero_grec = (void *)&igmpv3_zero_grec;
1998	struct iphdr *iph = ip_hdr(skb);
1999	struct amt_group_node *gnode;
2000	union amt_addr group, host;
2001	struct igmpv3_grec *grec;
2002	u16 nsrcs;
2003	int i;
2004
2005	for (i = 0; i < ntohs(ihrv3->ngrec); i++) {
2006		len += sizeof(*grec);
2007		if (!ip_mc_may_pull(skb, len))
2008			break;
2009
2010		grec = (void *)(skb->data + len - sizeof(*grec));
2011		nsrcs = ntohs(grec->grec_nsrcs);
2012
2013		len += nsrcs * sizeof(__be32);
2014		if (!ip_mc_may_pull(skb, len))
2015			break;
2016
2017		memset(&group, 0, sizeof(union amt_addr));
2018		group.ip4 = grec->grec_mca;
2019		memset(&host, 0, sizeof(union amt_addr));
2020		host.ip4 = iph->saddr;
2021		gnode = amt_lookup_group(tunnel, &group, &host, false);
2022		if (!gnode) {
2023			gnode = amt_add_group(amt, tunnel, &group, &host,
2024					      false);
2025			if (IS_ERR(gnode))
2026				continue;
2027		}
2028
2029		amt_add_srcs(amt, tunnel, gnode, grec, false);
2030		switch (grec->grec_type) {
2031		case IGMPV3_MODE_IS_INCLUDE:
2032			amt_mcast_is_in_handler(amt, tunnel, gnode, grec,
2033						zero_grec, false);
2034			break;
2035		case IGMPV3_MODE_IS_EXCLUDE:
2036			amt_mcast_is_ex_handler(amt, tunnel, gnode, grec,
2037						zero_grec, false);
2038			break;
2039		case IGMPV3_CHANGE_TO_INCLUDE:
2040			amt_mcast_to_in_handler(amt, tunnel, gnode, grec,
2041						zero_grec, false);
2042			break;
2043		case IGMPV3_CHANGE_TO_EXCLUDE:
2044			amt_mcast_to_ex_handler(amt, tunnel, gnode, grec,
2045						zero_grec, false);
2046			break;
2047		case IGMPV3_ALLOW_NEW_SOURCES:
2048			amt_mcast_allow_handler(amt, tunnel, gnode, grec,
2049						zero_grec, false);
2050			break;
2051		case IGMPV3_BLOCK_OLD_SOURCES:
2052			amt_mcast_block_handler(amt, tunnel, gnode, grec,
2053						zero_grec, false);
2054			break;
2055		default:
2056			break;
2057		}
2058		amt_cleanup_srcs(amt, tunnel, gnode);
2059	}
2060}
2061
2062/* caller held tunnel->lock */
2063static void amt_igmp_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2064				    struct amt_tunnel_list *tunnel)
2065{
2066	struct igmphdr *ih = igmp_hdr(skb);
2067
2068	switch (ih->type) {
2069	case IGMPV3_HOST_MEMBERSHIP_REPORT:
2070		amt_igmpv3_report_handler(amt, skb, tunnel);
2071		break;
2072	case IGMPV2_HOST_MEMBERSHIP_REPORT:
2073		amt_igmpv2_report_handler(amt, skb, tunnel);
2074		break;
2075	case IGMP_HOST_LEAVE_MESSAGE:
2076		amt_igmpv2_leave_handler(amt, skb, tunnel);
2077		break;
2078	default:
2079		break;
2080	}
2081}
2082
2083#if IS_ENABLED(CONFIG_IPV6)
2084/* RFC 3810
2085 * 8.3.2. In the Presence of MLDv1 Multicast Address Listeners
2086 *
2087 * When Multicast Address Compatibility Mode is MLDv2, a router acts
2088 * using the MLDv2 protocol for that multicast address.  When Multicast
2089 * Address Compatibility Mode is MLDv1, a router internally translates
2090 * the following MLDv1 messages for that multicast address to their
2091 * MLDv2 equivalents:
2092 *
2093 * MLDv1 Message                 MLDv2 Equivalent
2094 * --------------                -----------------
2095 * Report                        IS_EX( {} )
2096 * Done                          TO_IN( {} )
2097 */
2098static void amt_mldv1_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2099				     struct amt_tunnel_list *tunnel)
2100{
2101	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2102	struct ipv6hdr *ip6h = ipv6_hdr(skb);
2103	struct amt_group_node *gnode;
2104	union amt_addr group, host;
2105
2106	memcpy(&group.ip6, &mld->mld_mca, sizeof(struct in6_addr));
2107	memcpy(&host.ip6, &ip6h->saddr, sizeof(struct in6_addr));
2108
2109	gnode = amt_lookup_group(tunnel, &group, &host, true);
2110	if (!gnode) {
2111		gnode = amt_add_group(amt, tunnel, &group, &host, true);
2112		if (!IS_ERR(gnode)) {
2113			gnode->filter_mode = MCAST_EXCLUDE;
2114			if (!mod_delayed_work(amt_wq, &gnode->group_timer,
2115					      msecs_to_jiffies(amt_gmi(amt))))
2116				dev_hold(amt->dev);
2117		}
2118	}
2119}
2120
2121/* RFC 3810
2122 * 8.3.2. In the Presence of MLDv1 Multicast Address Listeners
2123 *
2124 * When Multicast Address Compatibility Mode is MLDv2, a router acts
2125 * using the MLDv2 protocol for that multicast address.  When Multicast
2126 * Address Compatibility Mode is MLDv1, a router internally translates
2127 * the following MLDv1 messages for that multicast address to their
2128 * MLDv2 equivalents:
2129 *
2130 * MLDv1 Message                 MLDv2 Equivalent
2131 * --------------                -----------------
2132 * Report                        IS_EX( {} )
2133 * Done                          TO_IN( {} )
2134 */
2135static void amt_mldv1_leave_handler(struct amt_dev *amt, struct sk_buff *skb,
2136				    struct amt_tunnel_list *tunnel)
2137{
2138	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2139	struct iphdr *iph = ip_hdr(skb);
2140	struct amt_group_node *gnode;
2141	union amt_addr group, host;
2142
2143	memcpy(&group.ip6, &mld->mld_mca, sizeof(struct in6_addr));
2144	memset(&host, 0, sizeof(union amt_addr));
2145	host.ip4 = iph->saddr;
2146
2147	gnode = amt_lookup_group(tunnel, &group, &host, true);
2148	if (gnode) {
2149		amt_del_group(amt, gnode);
2150		return;
2151	}
2152}
2153
2154static void amt_mldv2_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2155				     struct amt_tunnel_list *tunnel)
2156{
2157	struct mld2_report *mld2r = (struct mld2_report *)icmp6_hdr(skb);
2158	int len = skb_transport_offset(skb) + sizeof(*mld2r);
2159	void *zero_grec = (void *)&mldv2_zero_grec;
2160	struct ipv6hdr *ip6h = ipv6_hdr(skb);
2161	struct amt_group_node *gnode;
2162	union amt_addr group, host;
2163	struct mld2_grec *grec;
2164	u16 nsrcs;
2165	int i;
2166
2167	for (i = 0; i < ntohs(mld2r->mld2r_ngrec); i++) {
2168		len += sizeof(*grec);
2169		if (!ipv6_mc_may_pull(skb, len))
2170			break;
2171
2172		grec = (void *)(skb->data + len - sizeof(*grec));
2173		nsrcs = ntohs(grec->grec_nsrcs);
2174
2175		len += nsrcs * sizeof(struct in6_addr);
2176		if (!ipv6_mc_may_pull(skb, len))
2177			break;
2178
2179		memset(&group, 0, sizeof(union amt_addr));
2180		group.ip6 = grec->grec_mca;
2181		memset(&host, 0, sizeof(union amt_addr));
2182		host.ip6 = ip6h->saddr;
2183		gnode = amt_lookup_group(tunnel, &group, &host, true);
2184		if (!gnode) {
2185			gnode = amt_add_group(amt, tunnel, &group, &host,
2186					      ETH_P_IPV6);
2187			if (IS_ERR(gnode))
2188				continue;
2189		}
2190
2191		amt_add_srcs(amt, tunnel, gnode, grec, true);
2192		switch (grec->grec_type) {
2193		case MLD2_MODE_IS_INCLUDE:
2194			amt_mcast_is_in_handler(amt, tunnel, gnode, grec,
2195						zero_grec, true);
2196			break;
2197		case MLD2_MODE_IS_EXCLUDE:
2198			amt_mcast_is_ex_handler(amt, tunnel, gnode, grec,
2199						zero_grec, true);
2200			break;
2201		case MLD2_CHANGE_TO_INCLUDE:
2202			amt_mcast_to_in_handler(amt, tunnel, gnode, grec,
2203						zero_grec, true);
2204			break;
2205		case MLD2_CHANGE_TO_EXCLUDE:
2206			amt_mcast_to_ex_handler(amt, tunnel, gnode, grec,
2207						zero_grec, true);
2208			break;
2209		case MLD2_ALLOW_NEW_SOURCES:
2210			amt_mcast_allow_handler(amt, tunnel, gnode, grec,
2211						zero_grec, true);
2212			break;
2213		case MLD2_BLOCK_OLD_SOURCES:
2214			amt_mcast_block_handler(amt, tunnel, gnode, grec,
2215						zero_grec, true);
2216			break;
2217		default:
2218			break;
2219		}
2220		amt_cleanup_srcs(amt, tunnel, gnode);
2221	}
2222}
2223
2224/* caller held tunnel->lock */
2225static void amt_mld_report_handler(struct amt_dev *amt, struct sk_buff *skb,
2226				   struct amt_tunnel_list *tunnel)
2227{
2228	struct mld_msg *mld = (struct mld_msg *)icmp6_hdr(skb);
2229
2230	switch (mld->mld_type) {
2231	case ICMPV6_MGM_REPORT:
2232		amt_mldv1_report_handler(amt, skb, tunnel);
2233		break;
2234	case ICMPV6_MLD2_REPORT:
2235		amt_mldv2_report_handler(amt, skb, tunnel);
2236		break;
2237	case ICMPV6_MGM_REDUCTION:
2238		amt_mldv1_leave_handler(amt, skb, tunnel);
2239		break;
2240	default:
2241		break;
2242	}
2243}
2244#endif
2245
2246static bool amt_advertisement_handler(struct amt_dev *amt, struct sk_buff *skb)
2247{
2248	struct amt_header_advertisement *amta;
2249	int hdr_size;
2250
2251	hdr_size = sizeof(*amta) + sizeof(struct udphdr);
2252	if (!pskb_may_pull(skb, hdr_size))
2253		return true;
2254
2255	amta = (struct amt_header_advertisement *)(udp_hdr(skb) + 1);
2256	if (!amta->ip4)
2257		return true;
2258
2259	if (amta->reserved || amta->version)
2260		return true;
2261
2262	if (ipv4_is_loopback(amta->ip4) || ipv4_is_multicast(amta->ip4) ||
2263	    ipv4_is_zeronet(amta->ip4))
2264		return true;
2265
2266	if (amt->status != AMT_STATUS_SENT_DISCOVERY ||
2267	    amt->nonce != amta->nonce)
2268		return true;
2269
2270	amt->remote_ip = amta->ip4;
2271	netdev_dbg(amt->dev, "advertised remote ip = %pI4\n", &amt->remote_ip);
2272	mod_delayed_work(amt_wq, &amt->req_wq, 0);
2273
2274	amt_update_gw_status(amt, AMT_STATUS_RECEIVED_ADVERTISEMENT, true);
2275	return false;
2276}
2277
2278static bool amt_multicast_data_handler(struct amt_dev *amt, struct sk_buff *skb)
2279{
2280	struct amt_header_mcast_data *amtmd;
2281	int hdr_size, len, err;
2282	struct ethhdr *eth;
2283	struct iphdr *iph;
2284
2285	if (READ_ONCE(amt->status) != AMT_STATUS_SENT_UPDATE)
2286		return true;
2287
2288	hdr_size = sizeof(*amtmd) + sizeof(struct udphdr);
2289	if (!pskb_may_pull(skb, hdr_size))
2290		return true;
2291
2292	amtmd = (struct amt_header_mcast_data *)(udp_hdr(skb) + 1);
2293	if (amtmd->reserved || amtmd->version)
2294		return true;
2295
2296	if (iptunnel_pull_header(skb, hdr_size, htons(ETH_P_IP), false))
2297		return true;
2298
2299	skb_reset_network_header(skb);
2300	skb_push(skb, sizeof(*eth));
2301	skb_reset_mac_header(skb);
2302	skb_pull(skb, sizeof(*eth));
2303	eth = eth_hdr(skb);
2304
2305	if (!pskb_may_pull(skb, sizeof(*iph)))
2306		return true;
2307	iph = ip_hdr(skb);
2308
2309	if (iph->version == 4) {
2310		if (!ipv4_is_multicast(iph->daddr))
2311			return true;
2312		skb->protocol = htons(ETH_P_IP);
2313		eth->h_proto = htons(ETH_P_IP);
2314		ip_eth_mc_map(iph->daddr, eth->h_dest);
2315#if IS_ENABLED(CONFIG_IPV6)
2316	} else if (iph->version == 6) {
2317		struct ipv6hdr *ip6h;
2318
2319		if (!pskb_may_pull(skb, sizeof(*ip6h)))
2320			return true;
2321
2322		ip6h = ipv6_hdr(skb);
2323		if (!ipv6_addr_is_multicast(&ip6h->daddr))
2324			return true;
2325		skb->protocol = htons(ETH_P_IPV6);
2326		eth->h_proto = htons(ETH_P_IPV6);
2327		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2328#endif
2329	} else {
2330		return true;
2331	}
2332
2333	skb->pkt_type = PACKET_MULTICAST;
2334	skb->ip_summed = CHECKSUM_NONE;
2335	len = skb->len;
2336	err = gro_cells_receive(&amt->gro_cells, skb);
2337	if (likely(err == NET_RX_SUCCESS))
2338		dev_sw_netstats_rx_add(amt->dev, len);
2339	else
2340		amt->dev->stats.rx_dropped++;
2341
2342	return false;
2343}
2344
2345static bool amt_membership_query_handler(struct amt_dev *amt,
2346					 struct sk_buff *skb)
2347{
2348	struct amt_header_membership_query *amtmq;
2349	struct igmpv3_query *ihv3;
2350	struct ethhdr *eth, *oeth;
2351	struct iphdr *iph;
2352	int hdr_size, len;
2353
2354	hdr_size = sizeof(*amtmq) + sizeof(struct udphdr);
2355	if (!pskb_may_pull(skb, hdr_size))
2356		return true;
2357
2358	amtmq = (struct amt_header_membership_query *)(udp_hdr(skb) + 1);
2359	if (amtmq->reserved || amtmq->version)
2360		return true;
2361
2362	if (amtmq->nonce != amt->nonce)
2363		return true;
2364
2365	hdr_size -= sizeof(*eth);
2366	if (iptunnel_pull_header(skb, hdr_size, htons(ETH_P_TEB), false))
2367		return true;
2368
2369	oeth = eth_hdr(skb);
2370	skb_reset_mac_header(skb);
2371	skb_pull(skb, sizeof(*eth));
2372	skb_reset_network_header(skb);
2373	eth = eth_hdr(skb);
2374	if (!pskb_may_pull(skb, sizeof(*iph)))
2375		return true;
2376
2377	iph = ip_hdr(skb);
2378	if (iph->version == 4) {
2379		if (READ_ONCE(amt->ready4))
2380			return true;
2381
2382		if (!pskb_may_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS +
2383				   sizeof(*ihv3)))
2384			return true;
2385
2386		if (!ipv4_is_multicast(iph->daddr))
2387			return true;
2388
2389		ihv3 = skb_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
2390		skb_reset_transport_header(skb);
2391		skb_push(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
2392		WRITE_ONCE(amt->ready4, true);
2393		amt->mac = amtmq->response_mac;
2394		amt->req_cnt = 0;
2395		amt->qi = ihv3->qqic;
2396		skb->protocol = htons(ETH_P_IP);
2397		eth->h_proto = htons(ETH_P_IP);
2398		ip_eth_mc_map(iph->daddr, eth->h_dest);
2399#if IS_ENABLED(CONFIG_IPV6)
2400	} else if (iph->version == 6) {
2401		struct mld2_query *mld2q;
2402		struct ipv6hdr *ip6h;
2403
2404		if (READ_ONCE(amt->ready6))
2405			return true;
2406
2407		if (!pskb_may_pull(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS +
2408				   sizeof(*mld2q)))
2409			return true;
2410
2411		ip6h = ipv6_hdr(skb);
2412		if (!ipv6_addr_is_multicast(&ip6h->daddr))
2413			return true;
2414
2415		mld2q = skb_pull(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS);
2416		skb_reset_transport_header(skb);
2417		skb_push(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS);
2418		WRITE_ONCE(amt->ready6, true);
2419		amt->mac = amtmq->response_mac;
2420		amt->req_cnt = 0;
2421		amt->qi = mld2q->mld2q_qqic;
2422		skb->protocol = htons(ETH_P_IPV6);
2423		eth->h_proto = htons(ETH_P_IPV6);
2424		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2425#endif
2426	} else {
2427		return true;
2428	}
2429
2430	ether_addr_copy(eth->h_source, oeth->h_source);
2431	skb->pkt_type = PACKET_MULTICAST;
2432	skb->ip_summed = CHECKSUM_NONE;
2433	len = skb->len;
2434	local_bh_disable();
2435	if (__netif_rx(skb) == NET_RX_SUCCESS) {
2436		amt_update_gw_status(amt, AMT_STATUS_RECEIVED_QUERY, true);
2437		dev_sw_netstats_rx_add(amt->dev, len);
2438	} else {
2439		amt->dev->stats.rx_dropped++;
2440	}
2441	local_bh_enable();
2442
2443	return false;
2444}
2445
2446static bool amt_update_handler(struct amt_dev *amt, struct sk_buff *skb)
2447{
2448	struct amt_header_membership_update *amtmu;
2449	struct amt_tunnel_list *tunnel;
2450	struct ethhdr *eth;
2451	struct iphdr *iph;
2452	int len, hdr_size;
2453
2454	iph = ip_hdr(skb);
2455
2456	hdr_size = sizeof(*amtmu) + sizeof(struct udphdr);
2457	if (!pskb_may_pull(skb, hdr_size))
2458		return true;
2459
2460	amtmu = (struct amt_header_membership_update *)(udp_hdr(skb) + 1);
2461	if (amtmu->reserved || amtmu->version)
2462		return true;
2463
2464	if (iptunnel_pull_header(skb, hdr_size, skb->protocol, false))
2465		return true;
2466
2467	skb_reset_network_header(skb);
2468
2469	list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list) {
2470		if (tunnel->ip4 == iph->saddr) {
2471			if ((amtmu->nonce == tunnel->nonce &&
2472			     amtmu->response_mac == tunnel->mac)) {
2473				mod_delayed_work(amt_wq, &tunnel->gc_wq,
2474						 msecs_to_jiffies(amt_gmi(amt))
2475								  * 3);
2476				goto report;
2477			} else {
2478				netdev_dbg(amt->dev, "Invalid MAC\n");
2479				return true;
2480			}
2481		}
2482	}
2483
2484	return true;
2485
2486report:
2487	if (!pskb_may_pull(skb, sizeof(*iph)))
2488		return true;
2489
2490	iph = ip_hdr(skb);
2491	if (iph->version == 4) {
2492		if (ip_mc_check_igmp(skb)) {
2493			netdev_dbg(amt->dev, "Invalid IGMP\n");
2494			return true;
2495		}
2496
2497		spin_lock_bh(&tunnel->lock);
2498		amt_igmp_report_handler(amt, skb, tunnel);
2499		spin_unlock_bh(&tunnel->lock);
2500
2501		skb_push(skb, sizeof(struct ethhdr));
2502		skb_reset_mac_header(skb);
2503		eth = eth_hdr(skb);
2504		skb->protocol = htons(ETH_P_IP);
2505		eth->h_proto = htons(ETH_P_IP);
2506		ip_eth_mc_map(iph->daddr, eth->h_dest);
2507#if IS_ENABLED(CONFIG_IPV6)
2508	} else if (iph->version == 6) {
2509		struct ipv6hdr *ip6h = ipv6_hdr(skb);
2510
2511		if (ipv6_mc_check_mld(skb)) {
2512			netdev_dbg(amt->dev, "Invalid MLD\n");
2513			return true;
2514		}
2515
2516		spin_lock_bh(&tunnel->lock);
2517		amt_mld_report_handler(amt, skb, tunnel);
2518		spin_unlock_bh(&tunnel->lock);
2519
2520		skb_push(skb, sizeof(struct ethhdr));
2521		skb_reset_mac_header(skb);
2522		eth = eth_hdr(skb);
2523		skb->protocol = htons(ETH_P_IPV6);
2524		eth->h_proto = htons(ETH_P_IPV6);
2525		ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
2526#endif
2527	} else {
2528		netdev_dbg(amt->dev, "Unsupported Protocol\n");
2529		return true;
2530	}
2531
2532	skb_pull(skb, sizeof(struct ethhdr));
2533	skb->pkt_type = PACKET_MULTICAST;
2534	skb->ip_summed = CHECKSUM_NONE;
2535	len = skb->len;
2536	if (__netif_rx(skb) == NET_RX_SUCCESS) {
2537		amt_update_relay_status(tunnel, AMT_STATUS_RECEIVED_UPDATE,
2538					true);
2539		dev_sw_netstats_rx_add(amt->dev, len);
2540	} else {
2541		amt->dev->stats.rx_dropped++;
2542	}
2543
2544	return false;
2545}
2546
2547static void amt_send_advertisement(struct amt_dev *amt, __be32 nonce,
2548				   __be32 daddr, __be16 dport)
2549{
2550	struct amt_header_advertisement *amta;
2551	int hlen, tlen, offset;
2552	struct socket *sock;
2553	struct udphdr *udph;
2554	struct sk_buff *skb;
2555	struct iphdr *iph;
2556	struct rtable *rt;
2557	struct flowi4 fl4;
2558	u32 len;
2559	int err;
2560
2561	rcu_read_lock();
2562	sock = rcu_dereference(amt->sock);
2563	if (!sock)
2564		goto out;
2565
2566	if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
2567		goto out;
2568
2569	rt = ip_route_output_ports(amt->net, &fl4, sock->sk,
2570				   daddr, amt->local_ip,
2571				   dport, amt->relay_port,
2572				   IPPROTO_UDP, 0,
2573				   amt->stream_dev->ifindex);
2574	if (IS_ERR(rt)) {
2575		amt->dev->stats.tx_errors++;
2576		goto out;
2577	}
2578
2579	hlen = LL_RESERVED_SPACE(amt->dev);
2580	tlen = amt->dev->needed_tailroom;
2581	len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amta);
2582	skb = netdev_alloc_skb_ip_align(amt->dev, len);
2583	if (!skb) {
2584		ip_rt_put(rt);
2585		amt->dev->stats.tx_errors++;
2586		goto out;
2587	}
2588
2589	skb->priority = TC_PRIO_CONTROL;
2590	skb_dst_set(skb, &rt->dst);
2591
2592	len = sizeof(*iph) + sizeof(*udph) + sizeof(*amta);
2593	skb_reset_network_header(skb);
2594	skb_put(skb, len);
2595	amta = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
2596	amta->version	= 0;
2597	amta->type	= AMT_MSG_ADVERTISEMENT;
2598	amta->reserved	= 0;
2599	amta->nonce	= nonce;
2600	amta->ip4	= amt->local_ip;
2601	skb_push(skb, sizeof(*udph));
2602	skb_reset_transport_header(skb);
2603	udph		= udp_hdr(skb);
2604	udph->source	= amt->relay_port;
2605	udph->dest	= dport;
2606	udph->len	= htons(sizeof(*amta) + sizeof(*udph));
2607	udph->check	= 0;
2608	offset = skb_transport_offset(skb);
2609	skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
2610	udph->check = csum_tcpudp_magic(amt->local_ip, daddr,
2611					sizeof(*udph) + sizeof(*amta),
2612					IPPROTO_UDP, skb->csum);
2613
2614	skb_push(skb, sizeof(*iph));
2615	iph		= ip_hdr(skb);
2616	iph->version	= 4;
2617	iph->ihl	= (sizeof(struct iphdr)) >> 2;
2618	iph->tos	= AMT_TOS;
2619	iph->frag_off	= 0;
2620	iph->ttl	= ip4_dst_hoplimit(&rt->dst);
2621	iph->daddr	= daddr;
2622	iph->saddr	= amt->local_ip;
2623	iph->protocol	= IPPROTO_UDP;
2624	iph->tot_len	= htons(len);
2625
2626	skb->ip_summed = CHECKSUM_NONE;
2627	ip_select_ident(amt->net, skb, NULL);
2628	ip_send_check(iph);
2629	err = ip_local_out(amt->net, sock->sk, skb);
2630	if (unlikely(net_xmit_eval(err)))
2631		amt->dev->stats.tx_errors++;
2632
2633out:
2634	rcu_read_unlock();
2635}
2636
2637static bool amt_discovery_handler(struct amt_dev *amt, struct sk_buff *skb)
2638{
2639	struct amt_header_discovery *amtd;
2640	struct udphdr *udph;
2641	struct iphdr *iph;
2642
2643	if (!pskb_may_pull(skb, sizeof(*udph) + sizeof(*amtd)))
2644		return true;
2645
2646	iph = ip_hdr(skb);
2647	udph = udp_hdr(skb);
2648	amtd = (struct amt_header_discovery *)(udp_hdr(skb) + 1);
2649
2650	if (amtd->reserved || amtd->version)
2651		return true;
2652
2653	amt_send_advertisement(amt, amtd->nonce, iph->saddr, udph->source);
2654
2655	return false;
2656}
2657
2658static bool amt_request_handler(struct amt_dev *amt, struct sk_buff *skb)
2659{
2660	struct amt_header_request *amtrh;
2661	struct amt_tunnel_list *tunnel;
2662	unsigned long long key;
2663	struct udphdr *udph;
2664	struct iphdr *iph;
2665	u64 mac;
2666	int i;
2667
2668	if (!pskb_may_pull(skb, sizeof(*udph) + sizeof(*amtrh)))
2669		return true;
2670
2671	iph = ip_hdr(skb);
2672	udph = udp_hdr(skb);
2673	amtrh = (struct amt_header_request *)(udp_hdr(skb) + 1);
2674
2675	if (amtrh->reserved1 || amtrh->reserved2 || amtrh->version)
2676		return true;
2677
2678	list_for_each_entry_rcu(tunnel, &amt->tunnel_list, list)
2679		if (tunnel->ip4 == iph->saddr)
2680			goto send;
2681
2682	spin_lock_bh(&amt->lock);
2683	if (amt->nr_tunnels >= amt->max_tunnels) {
2684		spin_unlock_bh(&amt->lock);
2685		icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
2686		return true;
2687	}
2688
2689	tunnel = kzalloc(sizeof(*tunnel) +
2690			 (sizeof(struct hlist_head) * amt->hash_buckets),
2691			 GFP_ATOMIC);
2692	if (!tunnel) {
2693		spin_unlock_bh(&amt->lock);
2694		return true;
2695	}
2696
2697	tunnel->source_port = udph->source;
2698	tunnel->ip4 = iph->saddr;
2699
2700	memcpy(&key, &tunnel->key, sizeof(unsigned long long));
2701	tunnel->amt = amt;
2702	spin_lock_init(&tunnel->lock);
2703	for (i = 0; i < amt->hash_buckets; i++)
2704		INIT_HLIST_HEAD(&tunnel->groups[i]);
2705
2706	INIT_DELAYED_WORK(&tunnel->gc_wq, amt_tunnel_expire);
2707
2708	list_add_tail_rcu(&tunnel->list, &amt->tunnel_list);
2709	tunnel->key = amt->key;
2710	__amt_update_relay_status(tunnel, AMT_STATUS_RECEIVED_REQUEST, true);
2711	amt->nr_tunnels++;
2712	mod_delayed_work(amt_wq, &tunnel->gc_wq,
2713			 msecs_to_jiffies(amt_gmi(amt)));
2714	spin_unlock_bh(&amt->lock);
2715
2716send:
2717	tunnel->nonce = amtrh->nonce;
2718	mac = siphash_3u32((__force u32)tunnel->ip4,
2719			   (__force u32)tunnel->source_port,
2720			   (__force u32)tunnel->nonce,
2721			   &tunnel->key);
2722	tunnel->mac = mac >> 16;
2723
2724	if (!netif_running(amt->dev) || !netif_running(amt->stream_dev))
2725		return true;
2726
2727	if (!amtrh->p)
2728		amt_send_igmp_gq(amt, tunnel);
2729	else
2730		amt_send_mld_gq(amt, tunnel);
2731
2732	return false;
2733}
2734
2735static void amt_gw_rcv(struct amt_dev *amt, struct sk_buff *skb)
2736{
2737	int type = amt_parse_type(skb);
2738	int err = 1;
2739
2740	if (type == -1)
2741		goto drop;
2742
2743	if (amt->mode == AMT_MODE_GATEWAY) {
2744		switch (type) {
2745		case AMT_MSG_ADVERTISEMENT:
2746			err = amt_advertisement_handler(amt, skb);
2747			break;
2748		case AMT_MSG_MEMBERSHIP_QUERY:
2749			err = amt_membership_query_handler(amt, skb);
2750			if (!err)
2751				return;
2752			break;
2753		default:
2754			netdev_dbg(amt->dev, "Invalid type of Gateway\n");
2755			break;
2756		}
2757	}
2758drop:
2759	if (err) {
2760		amt->dev->stats.rx_dropped++;
2761		kfree_skb(skb);
2762	} else {
2763		consume_skb(skb);
2764	}
2765}
2766
2767static int amt_rcv(struct sock *sk, struct sk_buff *skb)
2768{
2769	struct amt_dev *amt;
2770	struct iphdr *iph;
2771	int type;
2772	bool err;
2773
2774	rcu_read_lock_bh();
2775	amt = rcu_dereference_sk_user_data(sk);
2776	if (!amt) {
2777		err = true;
2778		kfree_skb(skb);
2779		goto out;
2780	}
2781
2782	skb->dev = amt->dev;
2783	iph = ip_hdr(skb);
2784	type = amt_parse_type(skb);
2785	if (type == -1) {
2786		err = true;
2787		goto drop;
2788	}
2789
2790	if (amt->mode == AMT_MODE_GATEWAY) {
2791		switch (type) {
2792		case AMT_MSG_ADVERTISEMENT:
2793			if (iph->saddr != amt->discovery_ip) {
2794				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2795				err = true;
2796				goto drop;
2797			}
2798			if (amt_queue_event(amt, AMT_EVENT_RECEIVE, skb)) {
2799				netdev_dbg(amt->dev, "AMT Event queue full\n");
2800				err = true;
2801				goto drop;
2802			}
2803			goto out;
2804		case AMT_MSG_MULTICAST_DATA:
2805			if (iph->saddr != amt->remote_ip) {
2806				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2807				err = true;
2808				goto drop;
2809			}
2810			err = amt_multicast_data_handler(amt, skb);
2811			if (err)
2812				goto drop;
2813			else
2814				goto out;
2815		case AMT_MSG_MEMBERSHIP_QUERY:
2816			if (iph->saddr != amt->remote_ip) {
2817				netdev_dbg(amt->dev, "Invalid Relay IP\n");
2818				err = true;
2819				goto drop;
2820			}
2821			if (amt_queue_event(amt, AMT_EVENT_RECEIVE, skb)) {
2822				netdev_dbg(amt->dev, "AMT Event queue full\n");
2823				err = true;
2824				goto drop;
2825			}
2826			goto out;
2827		default:
2828			err = true;
2829			netdev_dbg(amt->dev, "Invalid type of Gateway\n");
2830			break;
2831		}
2832	} else {
2833		switch (type) {
2834		case AMT_MSG_DISCOVERY:
2835			err = amt_discovery_handler(amt, skb);
2836			break;
2837		case AMT_MSG_REQUEST:
2838			err = amt_request_handler(amt, skb);
2839			break;
2840		case AMT_MSG_MEMBERSHIP_UPDATE:
2841			err = amt_update_handler(amt, skb);
2842			if (err)
2843				goto drop;
2844			else
2845				goto out;
2846		default:
2847			err = true;
2848			netdev_dbg(amt->dev, "Invalid type of relay\n");
2849			break;
2850		}
2851	}
2852drop:
2853	if (err) {
2854		amt->dev->stats.rx_dropped++;
2855		kfree_skb(skb);
2856	} else {
2857		consume_skb(skb);
2858	}
2859out:
2860	rcu_read_unlock_bh();
2861	return 0;
2862}
2863
2864static void amt_event_work(struct work_struct *work)
2865{
2866	struct amt_dev *amt = container_of(work, struct amt_dev, event_wq);
2867	struct sk_buff *skb;
2868	u8 event;
2869	int i;
2870
2871	for (i = 0; i < AMT_MAX_EVENTS; i++) {
2872		spin_lock_bh(&amt->lock);
2873		if (amt->nr_events == 0) {
2874			spin_unlock_bh(&amt->lock);
2875			return;
2876		}
2877		event = amt->events[amt->event_idx].event;
2878		skb = amt->events[amt->event_idx].skb;
2879		amt->events[amt->event_idx].event = AMT_EVENT_NONE;
2880		amt->events[amt->event_idx].skb = NULL;
2881		amt->nr_events--;
2882		amt->event_idx++;
2883		amt->event_idx %= AMT_MAX_EVENTS;
2884		spin_unlock_bh(&amt->lock);
2885
2886		switch (event) {
2887		case AMT_EVENT_RECEIVE:
2888			amt_gw_rcv(amt, skb);
2889			break;
2890		case AMT_EVENT_SEND_DISCOVERY:
2891			amt_event_send_discovery(amt);
2892			break;
2893		case AMT_EVENT_SEND_REQUEST:
2894			amt_event_send_request(amt);
2895			break;
2896		default:
2897			kfree_skb(skb);
2898			break;
2899		}
2900	}
2901}
2902
2903static int amt_err_lookup(struct sock *sk, struct sk_buff *skb)
2904{
2905	struct amt_dev *amt;
2906	int type;
2907
2908	rcu_read_lock_bh();
2909	amt = rcu_dereference_sk_user_data(sk);
2910	if (!amt)
2911		goto out;
2912
2913	if (amt->mode != AMT_MODE_GATEWAY)
2914		goto drop;
2915
2916	type = amt_parse_type(skb);
2917	if (type == -1)
2918		goto drop;
2919
2920	netdev_dbg(amt->dev, "Received IGMP Unreachable of %s\n",
2921		   type_str[type]);
2922	switch (type) {
2923	case AMT_MSG_DISCOVERY:
2924		break;
2925	case AMT_MSG_REQUEST:
2926	case AMT_MSG_MEMBERSHIP_UPDATE:
2927		if (READ_ONCE(amt->status) >= AMT_STATUS_RECEIVED_ADVERTISEMENT)
2928			mod_delayed_work(amt_wq, &amt->req_wq, 0);
2929		break;
2930	default:
2931		goto drop;
2932	}
2933out:
2934	rcu_read_unlock_bh();
2935	return 0;
2936drop:
2937	rcu_read_unlock_bh();
2938	amt->dev->stats.rx_dropped++;
2939	return 0;
2940}
2941
2942static struct socket *amt_create_sock(struct net *net, __be16 port)
2943{
2944	struct udp_port_cfg udp_conf;
2945	struct socket *sock;
2946	int err;
2947
2948	memset(&udp_conf, 0, sizeof(udp_conf));
2949	udp_conf.family = AF_INET;
2950	udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
2951
2952	udp_conf.local_udp_port = port;
2953
2954	err = udp_sock_create(net, &udp_conf, &sock);
2955	if (err < 0)
2956		return ERR_PTR(err);
2957
2958	return sock;
2959}
2960
2961static int amt_socket_create(struct amt_dev *amt)
2962{
2963	struct udp_tunnel_sock_cfg tunnel_cfg;
2964	struct socket *sock;
2965
2966	sock = amt_create_sock(amt->net, amt->relay_port);
2967	if (IS_ERR(sock))
2968		return PTR_ERR(sock);
2969
2970	/* Mark socket as an encapsulation socket */
2971	memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
2972	tunnel_cfg.sk_user_data = amt;
2973	tunnel_cfg.encap_type = 1;
2974	tunnel_cfg.encap_rcv = amt_rcv;
2975	tunnel_cfg.encap_err_lookup = amt_err_lookup;
2976	tunnel_cfg.encap_destroy = NULL;
2977	setup_udp_tunnel_sock(amt->net, sock, &tunnel_cfg);
2978
2979	rcu_assign_pointer(amt->sock, sock);
2980	return 0;
2981}
2982
2983static int amt_dev_open(struct net_device *dev)
2984{
2985	struct amt_dev *amt = netdev_priv(dev);
2986	int err;
2987
2988	amt->ready4 = false;
2989	amt->ready6 = false;
2990	amt->event_idx = 0;
2991	amt->nr_events = 0;
2992
2993	err = amt_socket_create(amt);
2994	if (err)
2995		return err;
2996
2997	amt->req_cnt = 0;
2998	amt->remote_ip = 0;
2999	amt->nonce = 0;
3000	get_random_bytes(&amt->key, sizeof(siphash_key_t));
3001
3002	amt->status = AMT_STATUS_INIT;
3003	if (amt->mode == AMT_MODE_GATEWAY) {
3004		mod_delayed_work(amt_wq, &amt->discovery_wq, 0);
3005		mod_delayed_work(amt_wq, &amt->req_wq, 0);
3006	} else if (amt->mode == AMT_MODE_RELAY) {
3007		mod_delayed_work(amt_wq, &amt->secret_wq,
3008				 msecs_to_jiffies(AMT_SECRET_TIMEOUT));
3009	}
3010	return err;
3011}
3012
3013static int amt_dev_stop(struct net_device *dev)
3014{
3015	struct amt_dev *amt = netdev_priv(dev);
3016	struct amt_tunnel_list *tunnel, *tmp;
3017	struct socket *sock;
3018	struct sk_buff *skb;
3019	int i;
3020
3021	cancel_delayed_work_sync(&amt->req_wq);
3022	cancel_delayed_work_sync(&amt->discovery_wq);
3023	cancel_delayed_work_sync(&amt->secret_wq);
3024
3025	/* shutdown */
3026	sock = rtnl_dereference(amt->sock);
3027	RCU_INIT_POINTER(amt->sock, NULL);
3028	synchronize_net();
3029	if (sock)
3030		udp_tunnel_sock_release(sock);
3031
3032	cancel_work_sync(&amt->event_wq);
3033	for (i = 0; i < AMT_MAX_EVENTS; i++) {
3034		skb = amt->events[i].skb;
3035		kfree_skb(skb);
3036		amt->events[i].event = AMT_EVENT_NONE;
3037		amt->events[i].skb = NULL;
3038	}
3039
3040	amt->ready4 = false;
3041	amt->ready6 = false;
3042	amt->req_cnt = 0;
3043	amt->remote_ip = 0;
3044
3045	list_for_each_entry_safe(tunnel, tmp, &amt->tunnel_list, list) {
3046		list_del_rcu(&tunnel->list);
3047		amt->nr_tunnels--;
3048		cancel_delayed_work_sync(&tunnel->gc_wq);
3049		amt_clear_groups(tunnel);
3050		kfree_rcu(tunnel, rcu);
3051	}
3052
3053	return 0;
3054}
3055
3056static const struct device_type amt_type = {
3057	.name = "amt",
3058};
3059
3060static int amt_dev_init(struct net_device *dev)
3061{
3062	struct amt_dev *amt = netdev_priv(dev);
3063	int err;
3064
3065	amt->dev = dev;
3066
3067	err = gro_cells_init(&amt->gro_cells, dev);
3068	if (err)
3069		return err;
3070
3071	return 0;
3072}
3073
3074static void amt_dev_uninit(struct net_device *dev)
3075{
3076	struct amt_dev *amt = netdev_priv(dev);
3077
3078	gro_cells_destroy(&amt->gro_cells);
3079}
3080
3081static const struct net_device_ops amt_netdev_ops = {
3082	.ndo_init               = amt_dev_init,
3083	.ndo_uninit             = amt_dev_uninit,
3084	.ndo_open		= amt_dev_open,
3085	.ndo_stop		= amt_dev_stop,
3086	.ndo_start_xmit         = amt_dev_xmit,
3087};
3088
3089static void amt_link_setup(struct net_device *dev)
3090{
3091	dev->netdev_ops         = &amt_netdev_ops;
3092	dev->needs_free_netdev  = true;
3093	SET_NETDEV_DEVTYPE(dev, &amt_type);
3094	dev->min_mtu		= ETH_MIN_MTU;
3095	dev->max_mtu		= ETH_MAX_MTU;
3096	dev->type		= ARPHRD_NONE;
3097	dev->flags		= IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
3098	dev->hard_header_len	= 0;
3099	dev->addr_len		= 0;
3100	dev->priv_flags		|= IFF_NO_QUEUE;
3101	dev->features		|= NETIF_F_LLTX;
3102	dev->features		|= NETIF_F_GSO_SOFTWARE;
3103	dev->features		|= NETIF_F_NETNS_LOCAL;
3104	dev->hw_features	|= NETIF_F_SG | NETIF_F_HW_CSUM;
3105	dev->hw_features	|= NETIF_F_FRAGLIST | NETIF_F_RXCSUM;
3106	dev->hw_features	|= NETIF_F_GSO_SOFTWARE;
3107	dev->pcpu_stat_type	= NETDEV_PCPU_STAT_TSTATS;
3108	eth_hw_addr_random(dev);
3109	eth_zero_addr(dev->broadcast);
3110	ether_setup(dev);
3111}
3112
3113static const struct nla_policy amt_policy[IFLA_AMT_MAX + 1] = {
3114	[IFLA_AMT_MODE]		= { .type = NLA_U32 },
3115	[IFLA_AMT_RELAY_PORT]	= { .type = NLA_U16 },
3116	[IFLA_AMT_GATEWAY_PORT]	= { .type = NLA_U16 },
3117	[IFLA_AMT_LINK]		= { .type = NLA_U32 },
3118	[IFLA_AMT_LOCAL_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
3119	[IFLA_AMT_REMOTE_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
3120	[IFLA_AMT_DISCOVERY_IP]	= { .len = sizeof_field(struct iphdr, daddr) },
3121	[IFLA_AMT_MAX_TUNNELS]	= { .type = NLA_U32 },
3122};
3123
3124static int amt_validate(struct nlattr *tb[], struct nlattr *data[],
3125			struct netlink_ext_ack *extack)
3126{
3127	if (!data)
3128		return -EINVAL;
3129
3130	if (!data[IFLA_AMT_LINK]) {
3131		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_LINK],
3132				    "Link attribute is required");
3133		return -EINVAL;
3134	}
3135
3136	if (!data[IFLA_AMT_MODE]) {
3137		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_MODE],
3138				    "Mode attribute is required");
3139		return -EINVAL;
3140	}
3141
3142	if (nla_get_u32(data[IFLA_AMT_MODE]) > AMT_MODE_MAX) {
3143		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_MODE],
3144				    "Mode attribute is not valid");
3145		return -EINVAL;
3146	}
3147
3148	if (!data[IFLA_AMT_LOCAL_IP]) {
3149		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_DISCOVERY_IP],
3150				    "Local attribute is required");
3151		return -EINVAL;
3152	}
3153
3154	if (!data[IFLA_AMT_DISCOVERY_IP] &&
3155	    nla_get_u32(data[IFLA_AMT_MODE]) == AMT_MODE_GATEWAY) {
3156		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_AMT_LOCAL_IP],
3157				    "Discovery attribute is required");
3158		return -EINVAL;
3159	}
3160
3161	return 0;
3162}
3163
3164static int amt_newlink(struct net *net, struct net_device *dev,
3165		       struct nlattr *tb[], struct nlattr *data[],
3166		       struct netlink_ext_ack *extack)
3167{
3168	struct amt_dev *amt = netdev_priv(dev);
3169	int err = -EINVAL;
3170
3171	amt->net = net;
3172	amt->mode = nla_get_u32(data[IFLA_AMT_MODE]);
3173
3174	if (data[IFLA_AMT_MAX_TUNNELS] &&
3175	    nla_get_u32(data[IFLA_AMT_MAX_TUNNELS]))
3176		amt->max_tunnels = nla_get_u32(data[IFLA_AMT_MAX_TUNNELS]);
3177	else
3178		amt->max_tunnels = AMT_MAX_TUNNELS;
3179
3180	spin_lock_init(&amt->lock);
3181	amt->max_groups = AMT_MAX_GROUP;
3182	amt->max_sources = AMT_MAX_SOURCE;
3183	amt->hash_buckets = AMT_HSIZE;
3184	amt->nr_tunnels = 0;
3185	get_random_bytes(&amt->hash_seed, sizeof(amt->hash_seed));
3186	amt->stream_dev = dev_get_by_index(net,
3187					   nla_get_u32(data[IFLA_AMT_LINK]));
3188	if (!amt->stream_dev) {
3189		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LINK],
3190				    "Can't find stream device");
3191		return -ENODEV;
3192	}
3193
3194	if (amt->stream_dev->type != ARPHRD_ETHER) {
3195		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LINK],
3196				    "Invalid stream device type");
3197		goto err;
3198	}
3199
3200	amt->local_ip = nla_get_in_addr(data[IFLA_AMT_LOCAL_IP]);
3201	if (ipv4_is_loopback(amt->local_ip) ||
3202	    ipv4_is_zeronet(amt->local_ip) ||
3203	    ipv4_is_multicast(amt->local_ip)) {
3204		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_LOCAL_IP],
3205				    "Invalid Local address");
3206		goto err;
3207	}
3208
3209	if (data[IFLA_AMT_RELAY_PORT])
3210		amt->relay_port = nla_get_be16(data[IFLA_AMT_RELAY_PORT]);
3211	else
3212		amt->relay_port = htons(IANA_AMT_UDP_PORT);
3213
3214	if (data[IFLA_AMT_GATEWAY_PORT])
3215		amt->gw_port = nla_get_be16(data[IFLA_AMT_GATEWAY_PORT]);
3216	else
3217		amt->gw_port = htons(IANA_AMT_UDP_PORT);
3218
3219	if (!amt->relay_port) {
3220		NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3221				    "relay port must not be 0");
3222		goto err;
3223	}
3224	if (amt->mode == AMT_MODE_RELAY) {
3225		amt->qrv = READ_ONCE(amt->net->ipv4.sysctl_igmp_qrv);
3226		amt->qri = 10;
3227		dev->needed_headroom = amt->stream_dev->needed_headroom +
3228				       AMT_RELAY_HLEN;
3229		dev->mtu = amt->stream_dev->mtu - AMT_RELAY_HLEN;
3230		dev->max_mtu = dev->mtu;
3231		dev->min_mtu = ETH_MIN_MTU + AMT_RELAY_HLEN;
3232	} else {
3233		if (!data[IFLA_AMT_DISCOVERY_IP]) {
3234			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3235					    "discovery must be set in gateway mode");
3236			goto err;
3237		}
3238		if (!amt->gw_port) {
3239			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3240					    "gateway port must not be 0");
3241			goto err;
3242		}
3243		amt->remote_ip = 0;
3244		amt->discovery_ip = nla_get_in_addr(data[IFLA_AMT_DISCOVERY_IP]);
3245		if (ipv4_is_loopback(amt->discovery_ip) ||
3246		    ipv4_is_zeronet(amt->discovery_ip) ||
3247		    ipv4_is_multicast(amt->discovery_ip)) {
3248			NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_AMT_DISCOVERY_IP],
3249					    "discovery must be unicast");
3250			goto err;
3251		}
3252
3253		dev->needed_headroom = amt->stream_dev->needed_headroom +
3254				       AMT_GW_HLEN;
3255		dev->mtu = amt->stream_dev->mtu - AMT_GW_HLEN;
3256		dev->max_mtu = dev->mtu;
3257		dev->min_mtu = ETH_MIN_MTU + AMT_GW_HLEN;
3258	}
3259	amt->qi = AMT_INIT_QUERY_INTERVAL;
3260
3261	err = register_netdevice(dev);
3262	if (err < 0) {
3263		netdev_dbg(dev, "failed to register new netdev %d\n", err);
3264		goto err;
3265	}
3266
3267	err = netdev_upper_dev_link(amt->stream_dev, dev, extack);
3268	if (err < 0) {
3269		unregister_netdevice(dev);
3270		goto err;
3271	}
3272
3273	INIT_DELAYED_WORK(&amt->discovery_wq, amt_discovery_work);
3274	INIT_DELAYED_WORK(&amt->req_wq, amt_req_work);
3275	INIT_DELAYED_WORK(&amt->secret_wq, amt_secret_work);
3276	INIT_WORK(&amt->event_wq, amt_event_work);
3277	INIT_LIST_HEAD(&amt->tunnel_list);
3278	return 0;
3279err:
3280	dev_put(amt->stream_dev);
3281	return err;
3282}
3283
3284static void amt_dellink(struct net_device *dev, struct list_head *head)
3285{
3286	struct amt_dev *amt = netdev_priv(dev);
3287
3288	unregister_netdevice_queue(dev, head);
3289	netdev_upper_dev_unlink(amt->stream_dev, dev);
3290	dev_put(amt->stream_dev);
3291}
3292
3293static size_t amt_get_size(const struct net_device *dev)
3294{
3295	return nla_total_size(sizeof(__u32)) + /* IFLA_AMT_MODE */
3296	       nla_total_size(sizeof(__u16)) + /* IFLA_AMT_RELAY_PORT */
3297	       nla_total_size(sizeof(__u16)) + /* IFLA_AMT_GATEWAY_PORT */
3298	       nla_total_size(sizeof(__u32)) + /* IFLA_AMT_LINK */
3299	       nla_total_size(sizeof(__u32)) + /* IFLA_MAX_TUNNELS */
3300	       nla_total_size(sizeof(struct iphdr)) + /* IFLA_AMT_DISCOVERY_IP */
3301	       nla_total_size(sizeof(struct iphdr)) + /* IFLA_AMT_REMOTE_IP */
3302	       nla_total_size(sizeof(struct iphdr)); /* IFLA_AMT_LOCAL_IP */
3303}
3304
3305static int amt_fill_info(struct sk_buff *skb, const struct net_device *dev)
3306{
3307	struct amt_dev *amt = netdev_priv(dev);
3308
3309	if (nla_put_u32(skb, IFLA_AMT_MODE, amt->mode))
3310		goto nla_put_failure;
3311	if (nla_put_be16(skb, IFLA_AMT_RELAY_PORT, amt->relay_port))
3312		goto nla_put_failure;
3313	if (nla_put_be16(skb, IFLA_AMT_GATEWAY_PORT, amt->gw_port))
3314		goto nla_put_failure;
3315	if (nla_put_u32(skb, IFLA_AMT_LINK, amt->stream_dev->ifindex))
3316		goto nla_put_failure;
3317	if (nla_put_in_addr(skb, IFLA_AMT_LOCAL_IP, amt->local_ip))
3318		goto nla_put_failure;
3319	if (nla_put_in_addr(skb, IFLA_AMT_DISCOVERY_IP, amt->discovery_ip))
3320		goto nla_put_failure;
3321	if (amt->remote_ip)
3322		if (nla_put_in_addr(skb, IFLA_AMT_REMOTE_IP, amt->remote_ip))
3323			goto nla_put_failure;
3324	if (nla_put_u32(skb, IFLA_AMT_MAX_TUNNELS, amt->max_tunnels))
3325		goto nla_put_failure;
3326
3327	return 0;
3328
3329nla_put_failure:
3330	return -EMSGSIZE;
3331}
3332
3333static struct rtnl_link_ops amt_link_ops __read_mostly = {
3334	.kind		= "amt",
3335	.maxtype	= IFLA_AMT_MAX,
3336	.policy		= amt_policy,
3337	.priv_size	= sizeof(struct amt_dev),
3338	.setup		= amt_link_setup,
3339	.validate	= amt_validate,
3340	.newlink	= amt_newlink,
3341	.dellink	= amt_dellink,
3342	.get_size       = amt_get_size,
3343	.fill_info      = amt_fill_info,
3344};
3345
3346static struct net_device *amt_lookup_upper_dev(struct net_device *dev)
3347{
3348	struct net_device *upper_dev;
3349	struct amt_dev *amt;
3350
3351	for_each_netdev(dev_net(dev), upper_dev) {
3352		if (netif_is_amt(upper_dev)) {
3353			amt = netdev_priv(upper_dev);
3354			if (amt->stream_dev == dev)
3355				return upper_dev;
3356		}
3357	}
3358
3359	return NULL;
3360}
3361
3362static int amt_device_event(struct notifier_block *unused,
3363			    unsigned long event, void *ptr)
3364{
3365	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3366	struct net_device *upper_dev;
3367	struct amt_dev *amt;
3368	LIST_HEAD(list);
3369	int new_mtu;
3370
3371	upper_dev = amt_lookup_upper_dev(dev);
3372	if (!upper_dev)
3373		return NOTIFY_DONE;
3374	amt = netdev_priv(upper_dev);
3375
3376	switch (event) {
3377	case NETDEV_UNREGISTER:
3378		amt_dellink(amt->dev, &list);
3379		unregister_netdevice_many(&list);
3380		break;
3381	case NETDEV_CHANGEMTU:
3382		if (amt->mode == AMT_MODE_RELAY)
3383			new_mtu = dev->mtu - AMT_RELAY_HLEN;
3384		else
3385			new_mtu = dev->mtu - AMT_GW_HLEN;
3386
3387		dev_set_mtu(amt->dev, new_mtu);
3388		break;
3389	}
3390
3391	return NOTIFY_DONE;
3392}
3393
3394static struct notifier_block amt_notifier_block __read_mostly = {
3395	.notifier_call = amt_device_event,
3396};
3397
3398static int __init amt_init(void)
3399{
3400	int err;
3401
3402	err = register_netdevice_notifier(&amt_notifier_block);
3403	if (err < 0)
3404		goto err;
3405
3406	err = rtnl_link_register(&amt_link_ops);
3407	if (err < 0)
3408		goto unregister_notifier;
3409
3410	amt_wq = alloc_workqueue("amt", WQ_UNBOUND, 0);
3411	if (!amt_wq) {
3412		err = -ENOMEM;
3413		goto rtnl_unregister;
3414	}
3415
3416	spin_lock_init(&source_gc_lock);
3417	spin_lock_bh(&source_gc_lock);
3418	INIT_DELAYED_WORK(&source_gc_wq, amt_source_gc_work);
3419	mod_delayed_work(amt_wq, &source_gc_wq,
3420			 msecs_to_jiffies(AMT_GC_INTERVAL));
3421	spin_unlock_bh(&source_gc_lock);
3422
3423	return 0;
3424
3425rtnl_unregister:
3426	rtnl_link_unregister(&amt_link_ops);
3427unregister_notifier:
3428	unregister_netdevice_notifier(&amt_notifier_block);
3429err:
3430	pr_err("error loading AMT module loaded\n");
3431	return err;
3432}
3433late_initcall(amt_init);
3434
3435static void __exit amt_fini(void)
3436{
3437	rtnl_link_unregister(&amt_link_ops);
3438	unregister_netdevice_notifier(&amt_notifier_block);
3439	cancel_delayed_work_sync(&source_gc_wq);
3440	__amt_source_gc_work();
3441	destroy_workqueue(amt_wq);
3442}
3443module_exit(amt_fini);
3444
3445MODULE_LICENSE("GPL");
3446MODULE_DESCRIPTION("Driver for Automatic Multicast Tunneling (AMT)");
3447MODULE_AUTHOR("Taehee Yoo <ap420073@gmail.com>");
3448MODULE_ALIAS_RTNL_LINK("amt");
3449