xref: /linux/net/tipc/udp_media.c (revision 2c63221cd9e5c0dad0424029aeb1c40faada8330)
1 /* net/tipc/udp_media.c: IP bearer support for TIPC
2  *
3  * Copyright (c) 2015, Ericsson AB
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. Neither the names of the copyright holders nor the names of its
15  *    contributors may be used to endorse or promote products derived from
16  *    this software without specific prior written permission.
17  *
18  * Alternatively, this software may be distributed under the terms of the
19  * GNU General Public License ("GPL") version 2 as published by the Free
20  * Software Foundation.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
23  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
26  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32  * POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 #include <linux/socket.h>
36 #include <linux/ip.h>
37 #include <linux/udp.h>
38 #include <linux/inet.h>
39 #include <linux/inetdevice.h>
40 #include <linux/igmp.h>
41 #include <linux/kernel.h>
42 #include <linux/workqueue.h>
43 #include <linux/list.h>
44 #include <net/sock.h>
45 #include <net/ip.h>
46 #include <net/udp_tunnel.h>
47 #include <net/ipv6_stubs.h>
48 #include <linux/tipc_netlink.h>
49 #include "core.h"
50 #include "addr.h"
51 #include "net.h"
52 #include "bearer.h"
53 #include "netlink.h"
54 #include "msg.h"
55 
56 /* IANA assigned UDP port */
57 #define UDP_PORT_DEFAULT	6118
58 
59 #define UDP_MIN_HEADROOM        48
60 
61 /**
62  * struct udp_media_addr - IP/UDP addressing information
63  *
64  * This is the bearer level originating address used in neighbor discovery
65  * messages, and all fields should be in network byte order
66  */
67 struct udp_media_addr {
68 	__be16	proto;
69 	__be16	port;
70 	union {
71 		struct in_addr ipv4;
72 		struct in6_addr ipv6;
73 	};
74 };
75 
76 /* struct udp_replicast - container for UDP remote addresses */
77 struct udp_replicast {
78 	struct udp_media_addr addr;
79 	struct dst_cache dst_cache;
80 	struct rcu_head rcu;
81 	struct list_head list;
82 };
83 
84 /**
85  * struct udp_bearer - ip/udp bearer data structure
86  * @bearer:	associated generic tipc bearer
87  * @ubsock:	bearer associated socket
88  * @ifindex:	local address scope
89  * @work:	used to schedule deferred work on a bearer
90  */
91 struct udp_bearer {
92 	struct tipc_bearer __rcu *bearer;
93 	struct socket *ubsock;
94 	u32 ifindex;
95 	struct work_struct work;
96 	struct udp_replicast rcast;
97 };
98 
99 static int tipc_udp_is_mcast_addr(struct udp_media_addr *addr)
100 {
101 	if (ntohs(addr->proto) == ETH_P_IP)
102 		return ipv4_is_multicast(addr->ipv4.s_addr);
103 #if IS_ENABLED(CONFIG_IPV6)
104 	else
105 		return ipv6_addr_is_multicast(&addr->ipv6);
106 #endif
107 	return 0;
108 }
109 
110 /* udp_media_addr_set - convert a ip/udp address to a TIPC media address */
111 static void tipc_udp_media_addr_set(struct tipc_media_addr *addr,
112 				    struct udp_media_addr *ua)
113 {
114 	memset(addr, 0, sizeof(struct tipc_media_addr));
115 	addr->media_id = TIPC_MEDIA_TYPE_UDP;
116 	memcpy(addr->value, ua, sizeof(struct udp_media_addr));
117 
118 	if (tipc_udp_is_mcast_addr(ua))
119 		addr->broadcast = TIPC_BROADCAST_SUPPORT;
120 }
121 
122 /* tipc_udp_addr2str - convert ip/udp address to string */
123 static int tipc_udp_addr2str(struct tipc_media_addr *a, char *buf, int size)
124 {
125 	struct udp_media_addr *ua = (struct udp_media_addr *)&a->value;
126 
127 	if (ntohs(ua->proto) == ETH_P_IP)
128 		snprintf(buf, size, "%pI4:%u", &ua->ipv4, ntohs(ua->port));
129 	else if (ntohs(ua->proto) == ETH_P_IPV6)
130 		snprintf(buf, size, "%pI6:%u", &ua->ipv6, ntohs(ua->port));
131 	else
132 		pr_err("Invalid UDP media address\n");
133 	return 0;
134 }
135 
136 /* tipc_udp_msg2addr - extract an ip/udp address from a TIPC ndisc message */
137 static int tipc_udp_msg2addr(struct tipc_bearer *b, struct tipc_media_addr *a,
138 			     char *msg)
139 {
140 	struct udp_media_addr *ua;
141 
142 	ua = (struct udp_media_addr *) (msg + TIPC_MEDIA_ADDR_OFFSET);
143 	if (msg[TIPC_MEDIA_TYPE_OFFSET] != TIPC_MEDIA_TYPE_UDP)
144 		return -EINVAL;
145 	tipc_udp_media_addr_set(a, ua);
146 	return 0;
147 }
148 
149 /* tipc_udp_addr2msg - write an ip/udp address to a TIPC ndisc message */
150 static int tipc_udp_addr2msg(char *msg, struct tipc_media_addr *a)
151 {
152 	memset(msg, 0, TIPC_MEDIA_INFO_SIZE);
153 	msg[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_UDP;
154 	memcpy(msg + TIPC_MEDIA_ADDR_OFFSET, a->value,
155 	       sizeof(struct udp_media_addr));
156 	return 0;
157 }
158 
159 /* tipc_send_msg - enqueue a send request */
160 static int tipc_udp_xmit(struct net *net, struct sk_buff *skb,
161 			 struct udp_bearer *ub, struct udp_media_addr *src,
162 			 struct udp_media_addr *dst, struct dst_cache *cache)
163 {
164 	struct dst_entry *ndst = dst_cache_get(cache);
165 	int ttl, err = 0;
166 
167 	if (dst->proto == htons(ETH_P_IP)) {
168 		struct rtable *rt = (struct rtable *)ndst;
169 
170 		if (!rt) {
171 			struct flowi4 fl = {
172 				.daddr = dst->ipv4.s_addr,
173 				.saddr = src->ipv4.s_addr,
174 				.flowi4_mark = skb->mark,
175 				.flowi4_proto = IPPROTO_UDP
176 			};
177 			rt = ip_route_output_key(net, &fl);
178 			if (IS_ERR(rt)) {
179 				err = PTR_ERR(rt);
180 				goto tx_error;
181 			}
182 			dst_cache_set_ip4(cache, &rt->dst, fl.saddr);
183 		}
184 
185 		ttl = ip4_dst_hoplimit(&rt->dst);
186 		udp_tunnel_xmit_skb(rt, ub->ubsock->sk, skb, src->ipv4.s_addr,
187 				    dst->ipv4.s_addr, 0, ttl, 0, src->port,
188 				    dst->port, false, true);
189 #if IS_ENABLED(CONFIG_IPV6)
190 	} else {
191 		if (!ndst) {
192 			struct flowi6 fl6 = {
193 				.flowi6_oif = ub->ifindex,
194 				.daddr = dst->ipv6,
195 				.saddr = src->ipv6,
196 				.flowi6_proto = IPPROTO_UDP
197 			};
198 			err = ipv6_stub->ipv6_dst_lookup(net, ub->ubsock->sk,
199 							 &ndst, &fl6);
200 			if (err)
201 				goto tx_error;
202 			dst_cache_set_ip6(cache, ndst, &fl6.saddr);
203 		}
204 		ttl = ip6_dst_hoplimit(ndst);
205 		err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb, NULL,
206 					   &src->ipv6, &dst->ipv6, 0, ttl, 0,
207 					   src->port, dst->port, false);
208 #endif
209 	}
210 	return err;
211 
212 tx_error:
213 	kfree_skb(skb);
214 	return err;
215 }
216 
217 static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
218 			     struct tipc_bearer *b,
219 			     struct tipc_media_addr *addr)
220 {
221 	struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
222 	struct udp_media_addr *dst = (struct udp_media_addr *)&addr->value;
223 	struct udp_replicast *rcast;
224 	struct udp_bearer *ub;
225 	int err = 0;
226 
227 	if (skb_headroom(skb) < UDP_MIN_HEADROOM) {
228 		err = pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC);
229 		if (err)
230 			goto out;
231 	}
232 
233 	skb_set_inner_protocol(skb, htons(ETH_P_TIPC));
234 	ub = rcu_dereference(b->media_ptr);
235 	if (!ub) {
236 		err = -ENODEV;
237 		goto out;
238 	}
239 
240 	if (addr->broadcast != TIPC_REPLICAST_SUPPORT)
241 		return tipc_udp_xmit(net, skb, ub, src, dst,
242 				     &ub->rcast.dst_cache);
243 
244 	/* Replicast, send an skb to each configured IP address */
245 	list_for_each_entry_rcu(rcast, &ub->rcast.list, list) {
246 		struct sk_buff *_skb;
247 
248 		_skb = pskb_copy(skb, GFP_ATOMIC);
249 		if (!_skb) {
250 			err = -ENOMEM;
251 			goto out;
252 		}
253 
254 		err = tipc_udp_xmit(net, _skb, ub, src, &rcast->addr,
255 				    &rcast->dst_cache);
256 		if (err)
257 			goto out;
258 	}
259 	err = 0;
260 out:
261 	kfree_skb(skb);
262 	return err;
263 }
264 
265 static bool tipc_udp_is_known_peer(struct tipc_bearer *b,
266 				   struct udp_media_addr *addr)
267 {
268 	struct udp_replicast *rcast, *tmp;
269 	struct udp_bearer *ub;
270 
271 	ub = rcu_dereference_rtnl(b->media_ptr);
272 	if (!ub) {
273 		pr_err_ratelimited("UDP bearer instance not found\n");
274 		return false;
275 	}
276 
277 	list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
278 		if (!memcmp(&rcast->addr, addr, sizeof(struct udp_media_addr)))
279 			return true;
280 	}
281 
282 	return false;
283 }
284 
285 static int tipc_udp_rcast_add(struct tipc_bearer *b,
286 			      struct udp_media_addr *addr)
287 {
288 	struct udp_replicast *rcast;
289 	struct udp_bearer *ub;
290 
291 	ub = rcu_dereference_rtnl(b->media_ptr);
292 	if (!ub)
293 		return -ENODEV;
294 
295 	rcast = kmalloc(sizeof(*rcast), GFP_ATOMIC);
296 	if (!rcast)
297 		return -ENOMEM;
298 
299 	if (dst_cache_init(&rcast->dst_cache, GFP_ATOMIC)) {
300 		kfree(rcast);
301 		return -ENOMEM;
302 	}
303 
304 	memcpy(&rcast->addr, addr, sizeof(struct udp_media_addr));
305 
306 	if (ntohs(addr->proto) == ETH_P_IP)
307 		pr_info("New replicast peer: %pI4\n", &rcast->addr.ipv4);
308 #if IS_ENABLED(CONFIG_IPV6)
309 	else if (ntohs(addr->proto) == ETH_P_IPV6)
310 		pr_info("New replicast peer: %pI6\n", &rcast->addr.ipv6);
311 #endif
312 	b->bcast_addr.broadcast = TIPC_REPLICAST_SUPPORT;
313 	list_add_rcu(&rcast->list, &ub->rcast.list);
314 	return 0;
315 }
316 
317 static int tipc_udp_rcast_disc(struct tipc_bearer *b, struct sk_buff *skb)
318 {
319 	struct udp_media_addr src = {0};
320 	struct udp_media_addr *dst;
321 
322 	dst = (struct udp_media_addr *)&b->bcast_addr.value;
323 	if (tipc_udp_is_mcast_addr(dst))
324 		return 0;
325 
326 	src.port = udp_hdr(skb)->source;
327 
328 	if (ip_hdr(skb)->version == 4) {
329 		struct iphdr *iphdr = ip_hdr(skb);
330 
331 		src.proto = htons(ETH_P_IP);
332 		src.ipv4.s_addr = iphdr->saddr;
333 		if (ipv4_is_multicast(iphdr->daddr))
334 			return 0;
335 #if IS_ENABLED(CONFIG_IPV6)
336 	} else if (ip_hdr(skb)->version == 6) {
337 		struct ipv6hdr *iphdr = ipv6_hdr(skb);
338 
339 		src.proto = htons(ETH_P_IPV6);
340 		src.ipv6 = iphdr->saddr;
341 		if (ipv6_addr_is_multicast(&iphdr->daddr))
342 			return 0;
343 #endif
344 	} else {
345 		return 0;
346 	}
347 
348 	if (likely(tipc_udp_is_known_peer(b, &src)))
349 		return 0;
350 
351 	return tipc_udp_rcast_add(b, &src);
352 }
353 
354 /* tipc_udp_recv - read data from bearer socket */
355 static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb)
356 {
357 	struct udp_bearer *ub;
358 	struct tipc_bearer *b;
359 	struct tipc_msg *hdr;
360 	int err;
361 
362 	ub = rcu_dereference_sk_user_data(sk);
363 	if (!ub) {
364 		pr_err_ratelimited("Failed to get UDP bearer reference");
365 		goto out;
366 	}
367 	skb_pull(skb, sizeof(struct udphdr));
368 	hdr = buf_msg(skb);
369 
370 	b = rcu_dereference(ub->bearer);
371 	if (!b)
372 		goto out;
373 
374 	if (b && test_bit(0, &b->up)) {
375 		tipc_rcv(sock_net(sk), skb, b);
376 		return 0;
377 	}
378 
379 	if (unlikely(msg_user(hdr) == LINK_CONFIG)) {
380 		err = tipc_udp_rcast_disc(b, skb);
381 		if (err)
382 			goto out;
383 	}
384 
385 out:
386 	kfree_skb(skb);
387 	return 0;
388 }
389 
390 static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote)
391 {
392 	int err = 0;
393 	struct ip_mreqn mreqn;
394 	struct sock *sk = ub->ubsock->sk;
395 
396 	if (ntohs(remote->proto) == ETH_P_IP) {
397 		mreqn.imr_multiaddr = remote->ipv4;
398 		mreqn.imr_ifindex = ub->ifindex;
399 		err = ip_mc_join_group(sk, &mreqn);
400 #if IS_ENABLED(CONFIG_IPV6)
401 	} else {
402 		err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex,
403 						   &remote->ipv6);
404 #endif
405 	}
406 	return err;
407 }
408 
409 static int __tipc_nl_add_udp_addr(struct sk_buff *skb,
410 				  struct udp_media_addr *addr, int nla_t)
411 {
412 	if (ntohs(addr->proto) == ETH_P_IP) {
413 		struct sockaddr_in ip4;
414 
415 		memset(&ip4, 0, sizeof(ip4));
416 		ip4.sin_family = AF_INET;
417 		ip4.sin_port = addr->port;
418 		ip4.sin_addr.s_addr = addr->ipv4.s_addr;
419 		if (nla_put(skb, nla_t, sizeof(ip4), &ip4))
420 			return -EMSGSIZE;
421 
422 #if IS_ENABLED(CONFIG_IPV6)
423 	} else if (ntohs(addr->proto) == ETH_P_IPV6) {
424 		struct sockaddr_in6 ip6;
425 
426 		memset(&ip6, 0, sizeof(ip6));
427 		ip6.sin6_family = AF_INET6;
428 		ip6.sin6_port  = addr->port;
429 		memcpy(&ip6.sin6_addr, &addr->ipv6, sizeof(struct in6_addr));
430 		if (nla_put(skb, nla_t, sizeof(ip6), &ip6))
431 			return -EMSGSIZE;
432 #endif
433 	}
434 
435 	return 0;
436 }
437 
438 int tipc_udp_nl_dump_remoteip(struct sk_buff *skb, struct netlink_callback *cb)
439 {
440 	u32 bid = cb->args[0];
441 	u32 skip_cnt = cb->args[1];
442 	u32 portid = NETLINK_CB(cb->skb).portid;
443 	struct udp_replicast *rcast, *tmp;
444 	struct tipc_bearer *b;
445 	struct udp_bearer *ub;
446 	void *hdr;
447 	int err;
448 	int i;
449 
450 	if (!bid && !skip_cnt) {
451 		struct nlattr **attrs = genl_dumpit_info(cb)->attrs;
452 		struct net *net = sock_net(skb->sk);
453 		struct nlattr *battrs[TIPC_NLA_BEARER_MAX + 1];
454 		char *bname;
455 
456 		if (!attrs[TIPC_NLA_BEARER])
457 			return -EINVAL;
458 
459 		err = nla_parse_nested_deprecated(battrs, TIPC_NLA_BEARER_MAX,
460 						  attrs[TIPC_NLA_BEARER],
461 						  tipc_nl_bearer_policy, NULL);
462 		if (err)
463 			return err;
464 
465 		if (!battrs[TIPC_NLA_BEARER_NAME])
466 			return -EINVAL;
467 
468 		bname = nla_data(battrs[TIPC_NLA_BEARER_NAME]);
469 
470 		rtnl_lock();
471 		b = tipc_bearer_find(net, bname);
472 		if (!b) {
473 			rtnl_unlock();
474 			return -EINVAL;
475 		}
476 		bid = b->identity;
477 	} else {
478 		struct net *net = sock_net(skb->sk);
479 		struct tipc_net *tn = net_generic(net, tipc_net_id);
480 
481 		rtnl_lock();
482 		b = rtnl_dereference(tn->bearer_list[bid]);
483 		if (!b) {
484 			rtnl_unlock();
485 			return -EINVAL;
486 		}
487 	}
488 
489 	ub = rtnl_dereference(b->media_ptr);
490 	if (!ub) {
491 		rtnl_unlock();
492 		return -EINVAL;
493 	}
494 
495 	i = 0;
496 	list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
497 		if (i < skip_cnt)
498 			goto count;
499 
500 		hdr = genlmsg_put(skb, portid, cb->nlh->nlmsg_seq,
501 				  &tipc_genl_family, NLM_F_MULTI,
502 				  TIPC_NL_BEARER_GET);
503 		if (!hdr)
504 			goto done;
505 
506 		err = __tipc_nl_add_udp_addr(skb, &rcast->addr,
507 					     TIPC_NLA_UDP_REMOTE);
508 		if (err) {
509 			genlmsg_cancel(skb, hdr);
510 			goto done;
511 		}
512 		genlmsg_end(skb, hdr);
513 count:
514 		i++;
515 	}
516 done:
517 	rtnl_unlock();
518 	cb->args[0] = bid;
519 	cb->args[1] = i;
520 
521 	return skb->len;
522 }
523 
524 int tipc_udp_nl_add_bearer_data(struct tipc_nl_msg *msg, struct tipc_bearer *b)
525 {
526 	struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
527 	struct udp_media_addr *dst;
528 	struct udp_bearer *ub;
529 	struct nlattr *nest;
530 
531 	ub = rtnl_dereference(b->media_ptr);
532 	if (!ub)
533 		return -ENODEV;
534 
535 	nest = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER_UDP_OPTS);
536 	if (!nest)
537 		goto msg_full;
538 
539 	if (__tipc_nl_add_udp_addr(msg->skb, src, TIPC_NLA_UDP_LOCAL))
540 		goto msg_full;
541 
542 	dst = (struct udp_media_addr *)&b->bcast_addr.value;
543 	if (__tipc_nl_add_udp_addr(msg->skb, dst, TIPC_NLA_UDP_REMOTE))
544 		goto msg_full;
545 
546 	if (!list_empty(&ub->rcast.list)) {
547 		if (nla_put_flag(msg->skb, TIPC_NLA_UDP_MULTI_REMOTEIP))
548 			goto msg_full;
549 	}
550 
551 	nla_nest_end(msg->skb, nest);
552 	return 0;
553 msg_full:
554 	nla_nest_cancel(msg->skb, nest);
555 	return -EMSGSIZE;
556 }
557 
558 /**
559  * tipc_parse_udp_addr - build udp media address from netlink data
560  * @nlattr:	netlink attribute containing sockaddr storage aligned address
561  * @addr:	tipc media address to fill with address, port and protocol type
562  * @scope_id:	IPv6 scope id pointer, not NULL indicates it's required
563  */
564 
565 static int tipc_parse_udp_addr(struct nlattr *nla, struct udp_media_addr *addr,
566 			       u32 *scope_id)
567 {
568 	struct sockaddr_storage sa;
569 
570 	nla_memcpy(&sa, nla, sizeof(sa));
571 	if (sa.ss_family == AF_INET) {
572 		struct sockaddr_in *ip4 = (struct sockaddr_in *)&sa;
573 
574 		addr->proto = htons(ETH_P_IP);
575 		addr->port = ip4->sin_port;
576 		addr->ipv4.s_addr = ip4->sin_addr.s_addr;
577 		return 0;
578 
579 #if IS_ENABLED(CONFIG_IPV6)
580 	} else if (sa.ss_family == AF_INET6) {
581 		struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)&sa;
582 
583 		addr->proto = htons(ETH_P_IPV6);
584 		addr->port = ip6->sin6_port;
585 		memcpy(&addr->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr));
586 
587 		/* Scope ID is only interesting for local addresses */
588 		if (scope_id) {
589 			int atype;
590 
591 			atype = ipv6_addr_type(&ip6->sin6_addr);
592 			if (__ipv6_addr_needs_scope_id(atype) &&
593 			    !ip6->sin6_scope_id) {
594 				return -EINVAL;
595 			}
596 
597 			*scope_id = ip6->sin6_scope_id ? : 0;
598 		}
599 
600 		return 0;
601 #endif
602 	}
603 	return -EADDRNOTAVAIL;
604 }
605 
606 int tipc_udp_nl_bearer_add(struct tipc_bearer *b, struct nlattr *attr)
607 {
608 	int err;
609 	struct udp_media_addr addr = {0};
610 	struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
611 	struct udp_media_addr *dst;
612 
613 	if (nla_parse_nested_deprecated(opts, TIPC_NLA_UDP_MAX, attr, tipc_nl_udp_policy, NULL))
614 		return -EINVAL;
615 
616 	if (!opts[TIPC_NLA_UDP_REMOTE])
617 		return -EINVAL;
618 
619 	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &addr, NULL);
620 	if (err)
621 		return err;
622 
623 	dst = (struct udp_media_addr *)&b->bcast_addr.value;
624 	if (tipc_udp_is_mcast_addr(dst)) {
625 		pr_err("Can't add remote ip to TIPC UDP multicast bearer\n");
626 		return -EINVAL;
627 	}
628 
629 	if (tipc_udp_is_known_peer(b, &addr))
630 		return 0;
631 
632 	return tipc_udp_rcast_add(b, &addr);
633 }
634 
635 /**
636  * tipc_udp_enable - callback to create a new udp bearer instance
637  * @net:	network namespace
638  * @b:		pointer to generic tipc_bearer
639  * @attrs:	netlink bearer configuration
640  *
641  * validate the bearer parameters and initialize the udp bearer
642  * rtnl_lock should be held
643  */
644 static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
645 			   struct nlattr *attrs[])
646 {
647 	int err = -EINVAL;
648 	struct udp_bearer *ub;
649 	struct udp_media_addr remote = {0};
650 	struct udp_media_addr local = {0};
651 	struct udp_port_cfg udp_conf = {0};
652 	struct udp_tunnel_sock_cfg tuncfg = {NULL};
653 	struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
654 	u8 node_id[NODE_ID_LEN] = {0,};
655 	int rmcast = 0;
656 
657 	ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
658 	if (!ub)
659 		return -ENOMEM;
660 
661 	INIT_LIST_HEAD(&ub->rcast.list);
662 
663 	if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
664 		goto err;
665 
666 	if (nla_parse_nested_deprecated(opts, TIPC_NLA_UDP_MAX, attrs[TIPC_NLA_BEARER_UDP_OPTS], tipc_nl_udp_policy, NULL))
667 		goto err;
668 
669 	if (!opts[TIPC_NLA_UDP_LOCAL] || !opts[TIPC_NLA_UDP_REMOTE]) {
670 		pr_err("Invalid UDP bearer configuration");
671 		err = -EINVAL;
672 		goto err;
673 	}
674 
675 	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_LOCAL], &local,
676 				  &ub->ifindex);
677 	if (err)
678 		goto err;
679 
680 	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &remote, NULL);
681 	if (err)
682 		goto err;
683 
684 	if (remote.proto != local.proto) {
685 		err = -EINVAL;
686 		goto err;
687 	}
688 
689 	/* Checking remote ip address */
690 	rmcast = tipc_udp_is_mcast_addr(&remote);
691 
692 	/* Autoconfigure own node identity if needed */
693 	if (!tipc_own_id(net)) {
694 		memcpy(node_id, local.ipv6.in6_u.u6_addr8, 16);
695 		tipc_net_init(net, node_id, 0);
696 	}
697 	if (!tipc_own_id(net)) {
698 		pr_warn("Failed to set node id, please configure manually\n");
699 		err = -EINVAL;
700 		goto err;
701 	}
702 
703 	b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP;
704 	b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
705 	rcu_assign_pointer(b->media_ptr, ub);
706 	rcu_assign_pointer(ub->bearer, b);
707 	tipc_udp_media_addr_set(&b->addr, &local);
708 	if (local.proto == htons(ETH_P_IP)) {
709 		struct net_device *dev;
710 
711 		dev = __ip_dev_find(net, local.ipv4.s_addr, false);
712 		if (!dev) {
713 			err = -ENODEV;
714 			goto err;
715 		}
716 		udp_conf.family = AF_INET;
717 
718 		/* Switch to use ANY to receive packets from group */
719 		if (rmcast)
720 			udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
721 		else
722 			udp_conf.local_ip.s_addr = local.ipv4.s_addr;
723 		udp_conf.use_udp_checksums = false;
724 		ub->ifindex = dev->ifindex;
725 		if (tipc_mtu_bad(dev, sizeof(struct iphdr) +
726 				      sizeof(struct udphdr))) {
727 			err = -EINVAL;
728 			goto err;
729 		}
730 		b->mtu = b->media->mtu;
731 #if IS_ENABLED(CONFIG_IPV6)
732 	} else if (local.proto == htons(ETH_P_IPV6)) {
733 		udp_conf.family = AF_INET6;
734 		udp_conf.use_udp6_tx_checksums = true;
735 		udp_conf.use_udp6_rx_checksums = true;
736 		if (rmcast)
737 			udp_conf.local_ip6 = in6addr_any;
738 		else
739 			udp_conf.local_ip6 = local.ipv6;
740 		b->mtu = 1280;
741 #endif
742 	} else {
743 		err = -EAFNOSUPPORT;
744 		goto err;
745 	}
746 	udp_conf.local_udp_port = local.port;
747 	err = udp_sock_create(net, &udp_conf, &ub->ubsock);
748 	if (err)
749 		goto err;
750 	tuncfg.sk_user_data = ub;
751 	tuncfg.encap_type = 1;
752 	tuncfg.encap_rcv = tipc_udp_recv;
753 	tuncfg.encap_destroy = NULL;
754 	setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg);
755 
756 	err = dst_cache_init(&ub->rcast.dst_cache, GFP_ATOMIC);
757 	if (err)
758 		goto free;
759 
760 	/**
761 	 * The bcast media address port is used for all peers and the ip
762 	 * is used if it's a multicast address.
763 	 */
764 	memcpy(&b->bcast_addr.value, &remote, sizeof(remote));
765 	if (rmcast)
766 		err = enable_mcast(ub, &remote);
767 	else
768 		err = tipc_udp_rcast_add(b, &remote);
769 	if (err)
770 		goto free;
771 
772 	return 0;
773 
774 free:
775 	dst_cache_destroy(&ub->rcast.dst_cache);
776 	udp_tunnel_sock_release(ub->ubsock);
777 err:
778 	kfree(ub);
779 	return err;
780 }
781 
782 /* cleanup_bearer - break the socket/bearer association */
783 static void cleanup_bearer(struct work_struct *work)
784 {
785 	struct udp_bearer *ub = container_of(work, struct udp_bearer, work);
786 	struct udp_replicast *rcast, *tmp;
787 
788 	list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
789 		dst_cache_destroy(&rcast->dst_cache);
790 		list_del_rcu(&rcast->list);
791 		kfree_rcu(rcast, rcu);
792 	}
793 
794 	dst_cache_destroy(&ub->rcast.dst_cache);
795 	udp_tunnel_sock_release(ub->ubsock);
796 	synchronize_net();
797 	kfree(ub);
798 }
799 
800 /* tipc_udp_disable - detach bearer from socket */
801 static void tipc_udp_disable(struct tipc_bearer *b)
802 {
803 	struct udp_bearer *ub;
804 
805 	ub = rtnl_dereference(b->media_ptr);
806 	if (!ub) {
807 		pr_err("UDP bearer instance not found\n");
808 		return;
809 	}
810 	sock_set_flag(ub->ubsock->sk, SOCK_DEAD);
811 	RCU_INIT_POINTER(ub->bearer, NULL);
812 
813 	/* sock_release need to be done outside of rtnl lock */
814 	INIT_WORK(&ub->work, cleanup_bearer);
815 	schedule_work(&ub->work);
816 }
817 
818 struct tipc_media udp_media_info = {
819 	.send_msg	= tipc_udp_send_msg,
820 	.enable_media	= tipc_udp_enable,
821 	.disable_media	= tipc_udp_disable,
822 	.addr2str	= tipc_udp_addr2str,
823 	.addr2msg	= tipc_udp_addr2msg,
824 	.msg2addr	= tipc_udp_msg2addr,
825 	.priority	= TIPC_DEF_LINK_PRI,
826 	.tolerance	= TIPC_DEF_LINK_TOL,
827 	.window		= TIPC_DEF_LINK_WIN,
828 	.mtu		= TIPC_DEF_LINK_UDP_MTU,
829 	.type_id	= TIPC_MEDIA_TYPE_UDP,
830 	.hwaddr_len	= 0,
831 	.name		= "udp"
832 };
833