xref: /linux/net/tipc/udp_media.c (revision 79b6bb73f888933cbcd20b0ef3976cde67951b72)
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_SKB_CB(skb)->flags = 0;
376 		tipc_rcv(sock_net(sk), skb, b);
377 		return 0;
378 	}
379 
380 	if (unlikely(msg_user(hdr) == LINK_CONFIG)) {
381 		err = tipc_udp_rcast_disc(b, skb);
382 		if (err)
383 			goto out;
384 	}
385 
386 out:
387 	kfree_skb(skb);
388 	return 0;
389 }
390 
391 static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote)
392 {
393 	int err = 0;
394 	struct ip_mreqn mreqn;
395 	struct sock *sk = ub->ubsock->sk;
396 
397 	if (ntohs(remote->proto) == ETH_P_IP) {
398 		mreqn.imr_multiaddr = remote->ipv4;
399 		mreqn.imr_ifindex = ub->ifindex;
400 		err = ip_mc_join_group(sk, &mreqn);
401 #if IS_ENABLED(CONFIG_IPV6)
402 	} else {
403 		err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex,
404 						   &remote->ipv6);
405 #endif
406 	}
407 	return err;
408 }
409 
410 static int __tipc_nl_add_udp_addr(struct sk_buff *skb,
411 				  struct udp_media_addr *addr, int nla_t)
412 {
413 	if (ntohs(addr->proto) == ETH_P_IP) {
414 		struct sockaddr_in ip4;
415 
416 		memset(&ip4, 0, sizeof(ip4));
417 		ip4.sin_family = AF_INET;
418 		ip4.sin_port = addr->port;
419 		ip4.sin_addr.s_addr = addr->ipv4.s_addr;
420 		if (nla_put(skb, nla_t, sizeof(ip4), &ip4))
421 			return -EMSGSIZE;
422 
423 #if IS_ENABLED(CONFIG_IPV6)
424 	} else if (ntohs(addr->proto) == ETH_P_IPV6) {
425 		struct sockaddr_in6 ip6;
426 
427 		memset(&ip6, 0, sizeof(ip6));
428 		ip6.sin6_family = AF_INET6;
429 		ip6.sin6_port  = addr->port;
430 		memcpy(&ip6.sin6_addr, &addr->ipv6, sizeof(struct in6_addr));
431 		if (nla_put(skb, nla_t, sizeof(ip6), &ip6))
432 			return -EMSGSIZE;
433 #endif
434 	}
435 
436 	return 0;
437 }
438 
439 int tipc_udp_nl_dump_remoteip(struct sk_buff *skb, struct netlink_callback *cb)
440 {
441 	u32 bid = cb->args[0];
442 	u32 skip_cnt = cb->args[1];
443 	u32 portid = NETLINK_CB(cb->skb).portid;
444 	struct udp_replicast *rcast, *tmp;
445 	struct tipc_bearer *b;
446 	struct udp_bearer *ub;
447 	void *hdr;
448 	int err;
449 	int i;
450 
451 	if (!bid && !skip_cnt) {
452 		struct nlattr **attrs = genl_dumpit_info(cb)->attrs;
453 		struct net *net = sock_net(skb->sk);
454 		struct nlattr *battrs[TIPC_NLA_BEARER_MAX + 1];
455 		char *bname;
456 
457 		if (!attrs[TIPC_NLA_BEARER])
458 			return -EINVAL;
459 
460 		err = nla_parse_nested_deprecated(battrs, TIPC_NLA_BEARER_MAX,
461 						  attrs[TIPC_NLA_BEARER],
462 						  tipc_nl_bearer_policy, NULL);
463 		if (err)
464 			return err;
465 
466 		if (!battrs[TIPC_NLA_BEARER_NAME])
467 			return -EINVAL;
468 
469 		bname = nla_data(battrs[TIPC_NLA_BEARER_NAME]);
470 
471 		rtnl_lock();
472 		b = tipc_bearer_find(net, bname);
473 		if (!b) {
474 			rtnl_unlock();
475 			return -EINVAL;
476 		}
477 		bid = b->identity;
478 	} else {
479 		struct net *net = sock_net(skb->sk);
480 		struct tipc_net *tn = net_generic(net, tipc_net_id);
481 
482 		rtnl_lock();
483 		b = rtnl_dereference(tn->bearer_list[bid]);
484 		if (!b) {
485 			rtnl_unlock();
486 			return -EINVAL;
487 		}
488 	}
489 
490 	ub = rtnl_dereference(b->media_ptr);
491 	if (!ub) {
492 		rtnl_unlock();
493 		return -EINVAL;
494 	}
495 
496 	i = 0;
497 	list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
498 		if (i < skip_cnt)
499 			goto count;
500 
501 		hdr = genlmsg_put(skb, portid, cb->nlh->nlmsg_seq,
502 				  &tipc_genl_family, NLM_F_MULTI,
503 				  TIPC_NL_BEARER_GET);
504 		if (!hdr)
505 			goto done;
506 
507 		err = __tipc_nl_add_udp_addr(skb, &rcast->addr,
508 					     TIPC_NLA_UDP_REMOTE);
509 		if (err) {
510 			genlmsg_cancel(skb, hdr);
511 			goto done;
512 		}
513 		genlmsg_end(skb, hdr);
514 count:
515 		i++;
516 	}
517 done:
518 	rtnl_unlock();
519 	cb->args[0] = bid;
520 	cb->args[1] = i;
521 
522 	return skb->len;
523 }
524 
525 int tipc_udp_nl_add_bearer_data(struct tipc_nl_msg *msg, struct tipc_bearer *b)
526 {
527 	struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
528 	struct udp_media_addr *dst;
529 	struct udp_bearer *ub;
530 	struct nlattr *nest;
531 
532 	ub = rtnl_dereference(b->media_ptr);
533 	if (!ub)
534 		return -ENODEV;
535 
536 	nest = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER_UDP_OPTS);
537 	if (!nest)
538 		goto msg_full;
539 
540 	if (__tipc_nl_add_udp_addr(msg->skb, src, TIPC_NLA_UDP_LOCAL))
541 		goto msg_full;
542 
543 	dst = (struct udp_media_addr *)&b->bcast_addr.value;
544 	if (__tipc_nl_add_udp_addr(msg->skb, dst, TIPC_NLA_UDP_REMOTE))
545 		goto msg_full;
546 
547 	if (!list_empty(&ub->rcast.list)) {
548 		if (nla_put_flag(msg->skb, TIPC_NLA_UDP_MULTI_REMOTEIP))
549 			goto msg_full;
550 	}
551 
552 	nla_nest_end(msg->skb, nest);
553 	return 0;
554 msg_full:
555 	nla_nest_cancel(msg->skb, nest);
556 	return -EMSGSIZE;
557 }
558 
559 /**
560  * tipc_parse_udp_addr - build udp media address from netlink data
561  * @nlattr:	netlink attribute containing sockaddr storage aligned address
562  * @addr:	tipc media address to fill with address, port and protocol type
563  * @scope_id:	IPv6 scope id pointer, not NULL indicates it's required
564  */
565 
566 static int tipc_parse_udp_addr(struct nlattr *nla, struct udp_media_addr *addr,
567 			       u32 *scope_id)
568 {
569 	struct sockaddr_storage sa;
570 
571 	nla_memcpy(&sa, nla, sizeof(sa));
572 	if (sa.ss_family == AF_INET) {
573 		struct sockaddr_in *ip4 = (struct sockaddr_in *)&sa;
574 
575 		addr->proto = htons(ETH_P_IP);
576 		addr->port = ip4->sin_port;
577 		addr->ipv4.s_addr = ip4->sin_addr.s_addr;
578 		return 0;
579 
580 #if IS_ENABLED(CONFIG_IPV6)
581 	} else if (sa.ss_family == AF_INET6) {
582 		struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)&sa;
583 
584 		addr->proto = htons(ETH_P_IPV6);
585 		addr->port = ip6->sin6_port;
586 		memcpy(&addr->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr));
587 
588 		/* Scope ID is only interesting for local addresses */
589 		if (scope_id) {
590 			int atype;
591 
592 			atype = ipv6_addr_type(&ip6->sin6_addr);
593 			if (__ipv6_addr_needs_scope_id(atype) &&
594 			    !ip6->sin6_scope_id) {
595 				return -EINVAL;
596 			}
597 
598 			*scope_id = ip6->sin6_scope_id ? : 0;
599 		}
600 
601 		return 0;
602 #endif
603 	}
604 	return -EADDRNOTAVAIL;
605 }
606 
607 int tipc_udp_nl_bearer_add(struct tipc_bearer *b, struct nlattr *attr)
608 {
609 	int err;
610 	struct udp_media_addr addr = {0};
611 	struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
612 	struct udp_media_addr *dst;
613 
614 	if (nla_parse_nested_deprecated(opts, TIPC_NLA_UDP_MAX, attr, tipc_nl_udp_policy, NULL))
615 		return -EINVAL;
616 
617 	if (!opts[TIPC_NLA_UDP_REMOTE])
618 		return -EINVAL;
619 
620 	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &addr, NULL);
621 	if (err)
622 		return err;
623 
624 	dst = (struct udp_media_addr *)&b->bcast_addr.value;
625 	if (tipc_udp_is_mcast_addr(dst)) {
626 		pr_err("Can't add remote ip to TIPC UDP multicast bearer\n");
627 		return -EINVAL;
628 	}
629 
630 	if (tipc_udp_is_known_peer(b, &addr))
631 		return 0;
632 
633 	return tipc_udp_rcast_add(b, &addr);
634 }
635 
636 /**
637  * tipc_udp_enable - callback to create a new udp bearer instance
638  * @net:	network namespace
639  * @b:		pointer to generic tipc_bearer
640  * @attrs:	netlink bearer configuration
641  *
642  * validate the bearer parameters and initialize the udp bearer
643  * rtnl_lock should be held
644  */
645 static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
646 			   struct nlattr *attrs[])
647 {
648 	int err = -EINVAL;
649 	struct udp_bearer *ub;
650 	struct udp_media_addr remote = {0};
651 	struct udp_media_addr local = {0};
652 	struct udp_port_cfg udp_conf = {0};
653 	struct udp_tunnel_sock_cfg tuncfg = {NULL};
654 	struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
655 	u8 node_id[NODE_ID_LEN] = {0,};
656 	int rmcast = 0;
657 
658 	ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
659 	if (!ub)
660 		return -ENOMEM;
661 
662 	INIT_LIST_HEAD(&ub->rcast.list);
663 
664 	if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
665 		goto err;
666 
667 	if (nla_parse_nested_deprecated(opts, TIPC_NLA_UDP_MAX, attrs[TIPC_NLA_BEARER_UDP_OPTS], tipc_nl_udp_policy, NULL))
668 		goto err;
669 
670 	if (!opts[TIPC_NLA_UDP_LOCAL] || !opts[TIPC_NLA_UDP_REMOTE]) {
671 		pr_err("Invalid UDP bearer configuration");
672 		err = -EINVAL;
673 		goto err;
674 	}
675 
676 	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_LOCAL], &local,
677 				  &ub->ifindex);
678 	if (err)
679 		goto err;
680 
681 	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &remote, NULL);
682 	if (err)
683 		goto err;
684 
685 	if (remote.proto != local.proto) {
686 		err = -EINVAL;
687 		goto err;
688 	}
689 
690 	/* Checking remote ip address */
691 	rmcast = tipc_udp_is_mcast_addr(&remote);
692 
693 	/* Autoconfigure own node identity if needed */
694 	if (!tipc_own_id(net)) {
695 		memcpy(node_id, local.ipv6.in6_u.u6_addr8, 16);
696 		tipc_net_init(net, node_id, 0);
697 	}
698 	if (!tipc_own_id(net)) {
699 		pr_warn("Failed to set node id, please configure manually\n");
700 		err = -EINVAL;
701 		goto err;
702 	}
703 
704 	b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP;
705 	b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
706 	rcu_assign_pointer(b->media_ptr, ub);
707 	rcu_assign_pointer(ub->bearer, b);
708 	tipc_udp_media_addr_set(&b->addr, &local);
709 	if (local.proto == htons(ETH_P_IP)) {
710 		struct net_device *dev;
711 
712 		dev = __ip_dev_find(net, local.ipv4.s_addr, false);
713 		if (!dev) {
714 			err = -ENODEV;
715 			goto err;
716 		}
717 		udp_conf.family = AF_INET;
718 
719 		/* Switch to use ANY to receive packets from group */
720 		if (rmcast)
721 			udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
722 		else
723 			udp_conf.local_ip.s_addr = local.ipv4.s_addr;
724 		udp_conf.use_udp_checksums = false;
725 		ub->ifindex = dev->ifindex;
726 		if (tipc_mtu_bad(dev, sizeof(struct iphdr) +
727 				      sizeof(struct udphdr))) {
728 			err = -EINVAL;
729 			goto err;
730 		}
731 		b->mtu = b->media->mtu;
732 #if IS_ENABLED(CONFIG_IPV6)
733 	} else if (local.proto == htons(ETH_P_IPV6)) {
734 		udp_conf.family = AF_INET6;
735 		udp_conf.use_udp6_tx_checksums = true;
736 		udp_conf.use_udp6_rx_checksums = true;
737 		if (rmcast)
738 			udp_conf.local_ip6 = in6addr_any;
739 		else
740 			udp_conf.local_ip6 = local.ipv6;
741 		b->mtu = 1280;
742 #endif
743 	} else {
744 		err = -EAFNOSUPPORT;
745 		goto err;
746 	}
747 	udp_conf.local_udp_port = local.port;
748 	err = udp_sock_create(net, &udp_conf, &ub->ubsock);
749 	if (err)
750 		goto err;
751 	tuncfg.sk_user_data = ub;
752 	tuncfg.encap_type = 1;
753 	tuncfg.encap_rcv = tipc_udp_recv;
754 	tuncfg.encap_destroy = NULL;
755 	setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg);
756 
757 	err = dst_cache_init(&ub->rcast.dst_cache, GFP_ATOMIC);
758 	if (err)
759 		goto free;
760 
761 	/**
762 	 * The bcast media address port is used for all peers and the ip
763 	 * is used if it's a multicast address.
764 	 */
765 	memcpy(&b->bcast_addr.value, &remote, sizeof(remote));
766 	if (rmcast)
767 		err = enable_mcast(ub, &remote);
768 	else
769 		err = tipc_udp_rcast_add(b, &remote);
770 	if (err)
771 		goto free;
772 
773 	return 0;
774 
775 free:
776 	dst_cache_destroy(&ub->rcast.dst_cache);
777 	udp_tunnel_sock_release(ub->ubsock);
778 err:
779 	kfree(ub);
780 	return err;
781 }
782 
783 /* cleanup_bearer - break the socket/bearer association */
784 static void cleanup_bearer(struct work_struct *work)
785 {
786 	struct udp_bearer *ub = container_of(work, struct udp_bearer, work);
787 	struct udp_replicast *rcast, *tmp;
788 
789 	list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
790 		dst_cache_destroy(&rcast->dst_cache);
791 		list_del_rcu(&rcast->list);
792 		kfree_rcu(rcast, rcu);
793 	}
794 
795 	dst_cache_destroy(&ub->rcast.dst_cache);
796 	udp_tunnel_sock_release(ub->ubsock);
797 	synchronize_net();
798 	kfree(ub);
799 }
800 
801 /* tipc_udp_disable - detach bearer from socket */
802 static void tipc_udp_disable(struct tipc_bearer *b)
803 {
804 	struct udp_bearer *ub;
805 
806 	ub = rtnl_dereference(b->media_ptr);
807 	if (!ub) {
808 		pr_err("UDP bearer instance not found\n");
809 		return;
810 	}
811 	sock_set_flag(ub->ubsock->sk, SOCK_DEAD);
812 	RCU_INIT_POINTER(ub->bearer, NULL);
813 
814 	/* sock_release need to be done outside of rtnl lock */
815 	INIT_WORK(&ub->work, cleanup_bearer);
816 	schedule_work(&ub->work);
817 }
818 
819 struct tipc_media udp_media_info = {
820 	.send_msg	= tipc_udp_send_msg,
821 	.enable_media	= tipc_udp_enable,
822 	.disable_media	= tipc_udp_disable,
823 	.addr2str	= tipc_udp_addr2str,
824 	.addr2msg	= tipc_udp_addr2msg,
825 	.msg2addr	= tipc_udp_msg2addr,
826 	.priority	= TIPC_DEF_LINK_PRI,
827 	.tolerance	= TIPC_DEF_LINK_TOL,
828 	.window		= TIPC_DEF_LINK_WIN,
829 	.mtu		= TIPC_DEF_LINK_UDP_MTU,
830 	.type_id	= TIPC_MEDIA_TYPE_UDP,
831 	.hwaddr_len	= 0,
832 	.name		= "udp"
833 };
834