xref: /openbmc/linux/net/tipc/udp_media.c (revision 74be2d3b)
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;
165 	int ttl, err = 0;
166 
167 	local_bh_disable();
168 	ndst = dst_cache_get(cache);
169 	if (dst->proto == htons(ETH_P_IP)) {
170 		struct rtable *rt = (struct rtable *)ndst;
171 
172 		if (!rt) {
173 			struct flowi4 fl = {
174 				.daddr = dst->ipv4.s_addr,
175 				.saddr = src->ipv4.s_addr,
176 				.flowi4_mark = skb->mark,
177 				.flowi4_proto = IPPROTO_UDP
178 			};
179 			rt = ip_route_output_key(net, &fl);
180 			if (IS_ERR(rt)) {
181 				err = PTR_ERR(rt);
182 				goto tx_error;
183 			}
184 			dst_cache_set_ip4(cache, &rt->dst, fl.saddr);
185 		}
186 
187 		ttl = ip4_dst_hoplimit(&rt->dst);
188 		udp_tunnel_xmit_skb(rt, ub->ubsock->sk, skb, src->ipv4.s_addr,
189 				    dst->ipv4.s_addr, 0, ttl, 0, src->port,
190 				    dst->port, false, true);
191 #if IS_ENABLED(CONFIG_IPV6)
192 	} else {
193 		if (!ndst) {
194 			struct flowi6 fl6 = {
195 				.flowi6_oif = ub->ifindex,
196 				.daddr = dst->ipv6,
197 				.saddr = src->ipv6,
198 				.flowi6_proto = IPPROTO_UDP
199 			};
200 			ndst = ipv6_stub->ipv6_dst_lookup_flow(net,
201 							       ub->ubsock->sk,
202 							       &fl6, NULL);
203 			if (IS_ERR(ndst)) {
204 				err = PTR_ERR(ndst);
205 				goto tx_error;
206 			}
207 			dst_cache_set_ip6(cache, ndst, &fl6.saddr);
208 		}
209 		ttl = ip6_dst_hoplimit(ndst);
210 		err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb, NULL,
211 					   &src->ipv6, &dst->ipv6, 0, ttl, 0,
212 					   src->port, dst->port, false);
213 #endif
214 	}
215 	local_bh_enable();
216 	return err;
217 
218 tx_error:
219 	local_bh_enable();
220 	kfree_skb(skb);
221 	return err;
222 }
223 
224 static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
225 			     struct tipc_bearer *b,
226 			     struct tipc_media_addr *addr)
227 {
228 	struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
229 	struct udp_media_addr *dst = (struct udp_media_addr *)&addr->value;
230 	struct udp_replicast *rcast;
231 	struct udp_bearer *ub;
232 	int err = 0;
233 
234 	if (skb_headroom(skb) < UDP_MIN_HEADROOM) {
235 		err = pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC);
236 		if (err)
237 			goto out;
238 	}
239 
240 	skb_set_inner_protocol(skb, htons(ETH_P_TIPC));
241 	ub = rcu_dereference(b->media_ptr);
242 	if (!ub) {
243 		err = -ENODEV;
244 		goto out;
245 	}
246 
247 	if (addr->broadcast != TIPC_REPLICAST_SUPPORT)
248 		return tipc_udp_xmit(net, skb, ub, src, dst,
249 				     &ub->rcast.dst_cache);
250 
251 	/* Replicast, send an skb to each configured IP address */
252 	list_for_each_entry_rcu(rcast, &ub->rcast.list, list) {
253 		struct sk_buff *_skb;
254 
255 		_skb = pskb_copy(skb, GFP_ATOMIC);
256 		if (!_skb) {
257 			err = -ENOMEM;
258 			goto out;
259 		}
260 
261 		err = tipc_udp_xmit(net, _skb, ub, src, &rcast->addr,
262 				    &rcast->dst_cache);
263 		if (err)
264 			goto out;
265 	}
266 	err = 0;
267 out:
268 	kfree_skb(skb);
269 	return err;
270 }
271 
272 static bool tipc_udp_is_known_peer(struct tipc_bearer *b,
273 				   struct udp_media_addr *addr)
274 {
275 	struct udp_replicast *rcast, *tmp;
276 	struct udp_bearer *ub;
277 
278 	ub = rcu_dereference_rtnl(b->media_ptr);
279 	if (!ub) {
280 		pr_err_ratelimited("UDP bearer instance not found\n");
281 		return false;
282 	}
283 
284 	list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
285 		if (!memcmp(&rcast->addr, addr, sizeof(struct udp_media_addr)))
286 			return true;
287 	}
288 
289 	return false;
290 }
291 
292 static int tipc_udp_rcast_add(struct tipc_bearer *b,
293 			      struct udp_media_addr *addr)
294 {
295 	struct udp_replicast *rcast;
296 	struct udp_bearer *ub;
297 
298 	ub = rcu_dereference_rtnl(b->media_ptr);
299 	if (!ub)
300 		return -ENODEV;
301 
302 	rcast = kmalloc(sizeof(*rcast), GFP_ATOMIC);
303 	if (!rcast)
304 		return -ENOMEM;
305 
306 	if (dst_cache_init(&rcast->dst_cache, GFP_ATOMIC)) {
307 		kfree(rcast);
308 		return -ENOMEM;
309 	}
310 
311 	memcpy(&rcast->addr, addr, sizeof(struct udp_media_addr));
312 
313 	if (ntohs(addr->proto) == ETH_P_IP)
314 		pr_info("New replicast peer: %pI4\n", &rcast->addr.ipv4);
315 #if IS_ENABLED(CONFIG_IPV6)
316 	else if (ntohs(addr->proto) == ETH_P_IPV6)
317 		pr_info("New replicast peer: %pI6\n", &rcast->addr.ipv6);
318 #endif
319 	b->bcast_addr.broadcast = TIPC_REPLICAST_SUPPORT;
320 	list_add_rcu(&rcast->list, &ub->rcast.list);
321 	return 0;
322 }
323 
324 static int tipc_udp_rcast_disc(struct tipc_bearer *b, struct sk_buff *skb)
325 {
326 	struct udp_media_addr src = {0};
327 	struct udp_media_addr *dst;
328 
329 	dst = (struct udp_media_addr *)&b->bcast_addr.value;
330 	if (tipc_udp_is_mcast_addr(dst))
331 		return 0;
332 
333 	src.port = udp_hdr(skb)->source;
334 
335 	if (ip_hdr(skb)->version == 4) {
336 		struct iphdr *iphdr = ip_hdr(skb);
337 
338 		src.proto = htons(ETH_P_IP);
339 		src.ipv4.s_addr = iphdr->saddr;
340 		if (ipv4_is_multicast(iphdr->daddr))
341 			return 0;
342 #if IS_ENABLED(CONFIG_IPV6)
343 	} else if (ip_hdr(skb)->version == 6) {
344 		struct ipv6hdr *iphdr = ipv6_hdr(skb);
345 
346 		src.proto = htons(ETH_P_IPV6);
347 		src.ipv6 = iphdr->saddr;
348 		if (ipv6_addr_is_multicast(&iphdr->daddr))
349 			return 0;
350 #endif
351 	} else {
352 		return 0;
353 	}
354 
355 	if (likely(tipc_udp_is_known_peer(b, &src)))
356 		return 0;
357 
358 	return tipc_udp_rcast_add(b, &src);
359 }
360 
361 /* tipc_udp_recv - read data from bearer socket */
362 static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb)
363 {
364 	struct udp_bearer *ub;
365 	struct tipc_bearer *b;
366 	struct tipc_msg *hdr;
367 	int err;
368 
369 	ub = rcu_dereference_sk_user_data(sk);
370 	if (!ub) {
371 		pr_err_ratelimited("Failed to get UDP bearer reference");
372 		goto out;
373 	}
374 	skb_pull(skb, sizeof(struct udphdr));
375 	hdr = buf_msg(skb);
376 
377 	b = rcu_dereference(ub->bearer);
378 	if (!b)
379 		goto out;
380 
381 	if (b && test_bit(0, &b->up)) {
382 		TIPC_SKB_CB(skb)->flags = 0;
383 		tipc_rcv(sock_net(sk), skb, b);
384 		return 0;
385 	}
386 
387 	if (unlikely(msg_user(hdr) == LINK_CONFIG)) {
388 		err = tipc_udp_rcast_disc(b, skb);
389 		if (err)
390 			goto out;
391 	}
392 
393 out:
394 	kfree_skb(skb);
395 	return 0;
396 }
397 
398 static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote)
399 {
400 	int err = 0;
401 	struct ip_mreqn mreqn;
402 	struct sock *sk = ub->ubsock->sk;
403 
404 	if (ntohs(remote->proto) == ETH_P_IP) {
405 		mreqn.imr_multiaddr = remote->ipv4;
406 		mreqn.imr_ifindex = ub->ifindex;
407 		err = ip_mc_join_group(sk, &mreqn);
408 #if IS_ENABLED(CONFIG_IPV6)
409 	} else {
410 		err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex,
411 						   &remote->ipv6);
412 #endif
413 	}
414 	return err;
415 }
416 
417 static int __tipc_nl_add_udp_addr(struct sk_buff *skb,
418 				  struct udp_media_addr *addr, int nla_t)
419 {
420 	if (ntohs(addr->proto) == ETH_P_IP) {
421 		struct sockaddr_in ip4;
422 
423 		memset(&ip4, 0, sizeof(ip4));
424 		ip4.sin_family = AF_INET;
425 		ip4.sin_port = addr->port;
426 		ip4.sin_addr.s_addr = addr->ipv4.s_addr;
427 		if (nla_put(skb, nla_t, sizeof(ip4), &ip4))
428 			return -EMSGSIZE;
429 
430 #if IS_ENABLED(CONFIG_IPV6)
431 	} else if (ntohs(addr->proto) == ETH_P_IPV6) {
432 		struct sockaddr_in6 ip6;
433 
434 		memset(&ip6, 0, sizeof(ip6));
435 		ip6.sin6_family = AF_INET6;
436 		ip6.sin6_port  = addr->port;
437 		memcpy(&ip6.sin6_addr, &addr->ipv6, sizeof(struct in6_addr));
438 		if (nla_put(skb, nla_t, sizeof(ip6), &ip6))
439 			return -EMSGSIZE;
440 #endif
441 	}
442 
443 	return 0;
444 }
445 
446 int tipc_udp_nl_dump_remoteip(struct sk_buff *skb, struct netlink_callback *cb)
447 {
448 	u32 bid = cb->args[0];
449 	u32 skip_cnt = cb->args[1];
450 	u32 portid = NETLINK_CB(cb->skb).portid;
451 	struct udp_replicast *rcast, *tmp;
452 	struct tipc_bearer *b;
453 	struct udp_bearer *ub;
454 	void *hdr;
455 	int err;
456 	int i;
457 
458 	if (!bid && !skip_cnt) {
459 		struct nlattr **attrs = genl_dumpit_info(cb)->attrs;
460 		struct net *net = sock_net(skb->sk);
461 		struct nlattr *battrs[TIPC_NLA_BEARER_MAX + 1];
462 		char *bname;
463 
464 		if (!attrs[TIPC_NLA_BEARER])
465 			return -EINVAL;
466 
467 		err = nla_parse_nested_deprecated(battrs, TIPC_NLA_BEARER_MAX,
468 						  attrs[TIPC_NLA_BEARER],
469 						  tipc_nl_bearer_policy, NULL);
470 		if (err)
471 			return err;
472 
473 		if (!battrs[TIPC_NLA_BEARER_NAME])
474 			return -EINVAL;
475 
476 		bname = nla_data(battrs[TIPC_NLA_BEARER_NAME]);
477 
478 		rtnl_lock();
479 		b = tipc_bearer_find(net, bname);
480 		if (!b) {
481 			rtnl_unlock();
482 			return -EINVAL;
483 		}
484 		bid = b->identity;
485 	} else {
486 		struct net *net = sock_net(skb->sk);
487 		struct tipc_net *tn = net_generic(net, tipc_net_id);
488 
489 		rtnl_lock();
490 		b = rtnl_dereference(tn->bearer_list[bid]);
491 		if (!b) {
492 			rtnl_unlock();
493 			return -EINVAL;
494 		}
495 	}
496 
497 	ub = rtnl_dereference(b->media_ptr);
498 	if (!ub) {
499 		rtnl_unlock();
500 		return -EINVAL;
501 	}
502 
503 	i = 0;
504 	list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
505 		if (i < skip_cnt)
506 			goto count;
507 
508 		hdr = genlmsg_put(skb, portid, cb->nlh->nlmsg_seq,
509 				  &tipc_genl_family, NLM_F_MULTI,
510 				  TIPC_NL_BEARER_GET);
511 		if (!hdr)
512 			goto done;
513 
514 		err = __tipc_nl_add_udp_addr(skb, &rcast->addr,
515 					     TIPC_NLA_UDP_REMOTE);
516 		if (err) {
517 			genlmsg_cancel(skb, hdr);
518 			goto done;
519 		}
520 		genlmsg_end(skb, hdr);
521 count:
522 		i++;
523 	}
524 done:
525 	rtnl_unlock();
526 	cb->args[0] = bid;
527 	cb->args[1] = i;
528 
529 	return skb->len;
530 }
531 
532 int tipc_udp_nl_add_bearer_data(struct tipc_nl_msg *msg, struct tipc_bearer *b)
533 {
534 	struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
535 	struct udp_media_addr *dst;
536 	struct udp_bearer *ub;
537 	struct nlattr *nest;
538 
539 	ub = rtnl_dereference(b->media_ptr);
540 	if (!ub)
541 		return -ENODEV;
542 
543 	nest = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER_UDP_OPTS);
544 	if (!nest)
545 		goto msg_full;
546 
547 	if (__tipc_nl_add_udp_addr(msg->skb, src, TIPC_NLA_UDP_LOCAL))
548 		goto msg_full;
549 
550 	dst = (struct udp_media_addr *)&b->bcast_addr.value;
551 	if (__tipc_nl_add_udp_addr(msg->skb, dst, TIPC_NLA_UDP_REMOTE))
552 		goto msg_full;
553 
554 	if (!list_empty(&ub->rcast.list)) {
555 		if (nla_put_flag(msg->skb, TIPC_NLA_UDP_MULTI_REMOTEIP))
556 			goto msg_full;
557 	}
558 
559 	nla_nest_end(msg->skb, nest);
560 	return 0;
561 msg_full:
562 	nla_nest_cancel(msg->skb, nest);
563 	return -EMSGSIZE;
564 }
565 
566 /**
567  * tipc_parse_udp_addr - build udp media address from netlink data
568  * @nlattr:	netlink attribute containing sockaddr storage aligned address
569  * @addr:	tipc media address to fill with address, port and protocol type
570  * @scope_id:	IPv6 scope id pointer, not NULL indicates it's required
571  */
572 
573 static int tipc_parse_udp_addr(struct nlattr *nla, struct udp_media_addr *addr,
574 			       u32 *scope_id)
575 {
576 	struct sockaddr_storage sa;
577 
578 	nla_memcpy(&sa, nla, sizeof(sa));
579 	if (sa.ss_family == AF_INET) {
580 		struct sockaddr_in *ip4 = (struct sockaddr_in *)&sa;
581 
582 		addr->proto = htons(ETH_P_IP);
583 		addr->port = ip4->sin_port;
584 		addr->ipv4.s_addr = ip4->sin_addr.s_addr;
585 		return 0;
586 
587 #if IS_ENABLED(CONFIG_IPV6)
588 	} else if (sa.ss_family == AF_INET6) {
589 		struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)&sa;
590 
591 		addr->proto = htons(ETH_P_IPV6);
592 		addr->port = ip6->sin6_port;
593 		memcpy(&addr->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr));
594 
595 		/* Scope ID is only interesting for local addresses */
596 		if (scope_id) {
597 			int atype;
598 
599 			atype = ipv6_addr_type(&ip6->sin6_addr);
600 			if (__ipv6_addr_needs_scope_id(atype) &&
601 			    !ip6->sin6_scope_id) {
602 				return -EINVAL;
603 			}
604 
605 			*scope_id = ip6->sin6_scope_id ? : 0;
606 		}
607 
608 		return 0;
609 #endif
610 	}
611 	return -EADDRNOTAVAIL;
612 }
613 
614 int tipc_udp_nl_bearer_add(struct tipc_bearer *b, struct nlattr *attr)
615 {
616 	int err;
617 	struct udp_media_addr addr = {0};
618 	struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
619 	struct udp_media_addr *dst;
620 
621 	if (nla_parse_nested_deprecated(opts, TIPC_NLA_UDP_MAX, attr, tipc_nl_udp_policy, NULL))
622 		return -EINVAL;
623 
624 	if (!opts[TIPC_NLA_UDP_REMOTE])
625 		return -EINVAL;
626 
627 	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &addr, NULL);
628 	if (err)
629 		return err;
630 
631 	dst = (struct udp_media_addr *)&b->bcast_addr.value;
632 	if (tipc_udp_is_mcast_addr(dst)) {
633 		pr_err("Can't add remote ip to TIPC UDP multicast bearer\n");
634 		return -EINVAL;
635 	}
636 
637 	if (tipc_udp_is_known_peer(b, &addr))
638 		return 0;
639 
640 	return tipc_udp_rcast_add(b, &addr);
641 }
642 
643 /**
644  * tipc_udp_enable - callback to create a new udp bearer instance
645  * @net:	network namespace
646  * @b:		pointer to generic tipc_bearer
647  * @attrs:	netlink bearer configuration
648  *
649  * validate the bearer parameters and initialize the udp bearer
650  * rtnl_lock should be held
651  */
652 static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
653 			   struct nlattr *attrs[])
654 {
655 	int err = -EINVAL;
656 	struct udp_bearer *ub;
657 	struct udp_media_addr remote = {0};
658 	struct udp_media_addr local = {0};
659 	struct udp_port_cfg udp_conf = {0};
660 	struct udp_tunnel_sock_cfg tuncfg = {NULL};
661 	struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
662 	u8 node_id[NODE_ID_LEN] = {0,};
663 	int rmcast = 0;
664 
665 	ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
666 	if (!ub)
667 		return -ENOMEM;
668 
669 	INIT_LIST_HEAD(&ub->rcast.list);
670 
671 	if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
672 		goto err;
673 
674 	if (nla_parse_nested_deprecated(opts, TIPC_NLA_UDP_MAX, attrs[TIPC_NLA_BEARER_UDP_OPTS], tipc_nl_udp_policy, NULL))
675 		goto err;
676 
677 	if (!opts[TIPC_NLA_UDP_LOCAL] || !opts[TIPC_NLA_UDP_REMOTE]) {
678 		pr_err("Invalid UDP bearer configuration");
679 		err = -EINVAL;
680 		goto err;
681 	}
682 
683 	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_LOCAL], &local,
684 				  &ub->ifindex);
685 	if (err)
686 		goto err;
687 
688 	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &remote, NULL);
689 	if (err)
690 		goto err;
691 
692 	if (remote.proto != local.proto) {
693 		err = -EINVAL;
694 		goto err;
695 	}
696 
697 	/* Checking remote ip address */
698 	rmcast = tipc_udp_is_mcast_addr(&remote);
699 
700 	/* Autoconfigure own node identity if needed */
701 	if (!tipc_own_id(net)) {
702 		memcpy(node_id, local.ipv6.in6_u.u6_addr8, 16);
703 		tipc_net_init(net, node_id, 0);
704 	}
705 	if (!tipc_own_id(net)) {
706 		pr_warn("Failed to set node id, please configure manually\n");
707 		err = -EINVAL;
708 		goto err;
709 	}
710 
711 	b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP;
712 	b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
713 	rcu_assign_pointer(b->media_ptr, ub);
714 	rcu_assign_pointer(ub->bearer, b);
715 	tipc_udp_media_addr_set(&b->addr, &local);
716 	if (local.proto == htons(ETH_P_IP)) {
717 		struct net_device *dev;
718 
719 		dev = __ip_dev_find(net, local.ipv4.s_addr, false);
720 		if (!dev) {
721 			err = -ENODEV;
722 			goto err;
723 		}
724 		udp_conf.family = AF_INET;
725 
726 		/* Switch to use ANY to receive packets from group */
727 		if (rmcast)
728 			udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
729 		else
730 			udp_conf.local_ip.s_addr = local.ipv4.s_addr;
731 		udp_conf.use_udp_checksums = false;
732 		ub->ifindex = dev->ifindex;
733 		if (tipc_mtu_bad(dev, sizeof(struct iphdr) +
734 				      sizeof(struct udphdr))) {
735 			err = -EINVAL;
736 			goto err;
737 		}
738 		b->mtu = b->media->mtu;
739 #if IS_ENABLED(CONFIG_IPV6)
740 	} else if (local.proto == htons(ETH_P_IPV6)) {
741 		udp_conf.family = AF_INET6;
742 		udp_conf.use_udp6_tx_checksums = true;
743 		udp_conf.use_udp6_rx_checksums = true;
744 		if (rmcast)
745 			udp_conf.local_ip6 = in6addr_any;
746 		else
747 			udp_conf.local_ip6 = local.ipv6;
748 		b->mtu = 1280;
749 #endif
750 	} else {
751 		err = -EAFNOSUPPORT;
752 		goto err;
753 	}
754 	udp_conf.local_udp_port = local.port;
755 	err = udp_sock_create(net, &udp_conf, &ub->ubsock);
756 	if (err)
757 		goto err;
758 	tuncfg.sk_user_data = ub;
759 	tuncfg.encap_type = 1;
760 	tuncfg.encap_rcv = tipc_udp_recv;
761 	tuncfg.encap_destroy = NULL;
762 	setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg);
763 
764 	err = dst_cache_init(&ub->rcast.dst_cache, GFP_ATOMIC);
765 	if (err)
766 		goto free;
767 
768 	/**
769 	 * The bcast media address port is used for all peers and the ip
770 	 * is used if it's a multicast address.
771 	 */
772 	memcpy(&b->bcast_addr.value, &remote, sizeof(remote));
773 	if (rmcast)
774 		err = enable_mcast(ub, &remote);
775 	else
776 		err = tipc_udp_rcast_add(b, &remote);
777 	if (err)
778 		goto free;
779 
780 	return 0;
781 
782 free:
783 	dst_cache_destroy(&ub->rcast.dst_cache);
784 	udp_tunnel_sock_release(ub->ubsock);
785 err:
786 	kfree(ub);
787 	return err;
788 }
789 
790 /* cleanup_bearer - break the socket/bearer association */
791 static void cleanup_bearer(struct work_struct *work)
792 {
793 	struct udp_bearer *ub = container_of(work, struct udp_bearer, work);
794 	struct udp_replicast *rcast, *tmp;
795 
796 	list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
797 		dst_cache_destroy(&rcast->dst_cache);
798 		list_del_rcu(&rcast->list);
799 		kfree_rcu(rcast, rcu);
800 	}
801 
802 	dst_cache_destroy(&ub->rcast.dst_cache);
803 	udp_tunnel_sock_release(ub->ubsock);
804 	synchronize_net();
805 	kfree(ub);
806 }
807 
808 /* tipc_udp_disable - detach bearer from socket */
809 static void tipc_udp_disable(struct tipc_bearer *b)
810 {
811 	struct udp_bearer *ub;
812 
813 	ub = rtnl_dereference(b->media_ptr);
814 	if (!ub) {
815 		pr_err("UDP bearer instance not found\n");
816 		return;
817 	}
818 	sock_set_flag(ub->ubsock->sk, SOCK_DEAD);
819 	RCU_INIT_POINTER(ub->bearer, NULL);
820 
821 	/* sock_release need to be done outside of rtnl lock */
822 	INIT_WORK(&ub->work, cleanup_bearer);
823 	schedule_work(&ub->work);
824 }
825 
826 struct tipc_media udp_media_info = {
827 	.send_msg	= tipc_udp_send_msg,
828 	.enable_media	= tipc_udp_enable,
829 	.disable_media	= tipc_udp_disable,
830 	.addr2str	= tipc_udp_addr2str,
831 	.addr2msg	= tipc_udp_addr2msg,
832 	.msg2addr	= tipc_udp_msg2addr,
833 	.priority	= TIPC_DEF_LINK_PRI,
834 	.tolerance	= TIPC_DEF_LINK_TOL,
835 	.min_win	= TIPC_DEF_LINK_WIN,
836 	.max_win	= TIPC_DEF_LINK_WIN,
837 	.mtu		= TIPC_DEF_LINK_UDP_MTU,
838 	.type_id	= TIPC_MEDIA_TYPE_UDP,
839 	.hwaddr_len	= 0,
840 	.name		= "udp"
841 };
842