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 */
 67struct 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 */
 77struct 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 */
 91struct 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
 99static 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 */
111static 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 */
123static 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 */
137static 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 */
150static 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 */
160static 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
212tx_error:
213	kfree_skb(skb);
214	return err;
215}
216
217static 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;
260out:
261	kfree_skb(skb);
262	return err;
263}
264
265static 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
285static 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
317static 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 */
355static 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
385out:
386	kfree_skb(skb);
387	return 0;
388}
389
390static 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
409static 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
438int 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 net *net = sock_net(skb->sk);
452		struct nlattr *battrs[TIPC_NLA_BEARER_MAX + 1];
453		struct nlattr **attrs;
454		char *bname;
455
456		err = tipc_nlmsg_parse(cb->nlh, &attrs);
457		if (err)
458			return err;
459
460		if (!attrs[TIPC_NLA_BEARER])
461			return -EINVAL;
462
463		err = nla_parse_nested_deprecated(battrs, TIPC_NLA_BEARER_MAX,
464						  attrs[TIPC_NLA_BEARER],
465						  tipc_nl_bearer_policy, NULL);
466		if (err)
467			return err;
468
469		if (!battrs[TIPC_NLA_BEARER_NAME])
470			return -EINVAL;
471
472		bname = nla_data(battrs[TIPC_NLA_BEARER_NAME]);
473
474		rtnl_lock();
475		b = tipc_bearer_find(net, bname);
476		if (!b) {
477			rtnl_unlock();
478			return -EINVAL;
479		}
480		bid = b->identity;
 
 
 
 
481	} else {
482		struct net *net = sock_net(skb->sk);
483		struct tipc_net *tn = net_generic(net, tipc_net_id);
484
485		rtnl_lock();
486		b = rtnl_dereference(tn->bearer_list[bid]);
487		if (!b) {
488			rtnl_unlock();
489			return -EINVAL;
490		}
491	}
492
493	ub = rtnl_dereference(b->media_ptr);
494	if (!ub) {
495		rtnl_unlock();
496		return -EINVAL;
497	}
 
 
498
499	i = 0;
500	list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
501		if (i < skip_cnt)
502			goto count;
503
504		hdr = genlmsg_put(skb, portid, cb->nlh->nlmsg_seq,
505				  &tipc_genl_family, NLM_F_MULTI,
506				  TIPC_NL_BEARER_GET);
507		if (!hdr)
508			goto done;
509
510		err = __tipc_nl_add_udp_addr(skb, &rcast->addr,
511					     TIPC_NLA_UDP_REMOTE);
512		if (err) {
513			genlmsg_cancel(skb, hdr);
514			goto done;
515		}
516		genlmsg_end(skb, hdr);
517count:
518		i++;
519	}
520done:
521	rtnl_unlock();
522	cb->args[0] = bid;
523	cb->args[1] = i;
524
525	return skb->len;
526}
527
528int tipc_udp_nl_add_bearer_data(struct tipc_nl_msg *msg, struct tipc_bearer *b)
529{
530	struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
531	struct udp_media_addr *dst;
532	struct udp_bearer *ub;
533	struct nlattr *nest;
534
535	ub = rtnl_dereference(b->media_ptr);
536	if (!ub)
537		return -ENODEV;
538
539	nest = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER_UDP_OPTS);
540	if (!nest)
541		goto msg_full;
542
543	if (__tipc_nl_add_udp_addr(msg->skb, src, TIPC_NLA_UDP_LOCAL))
544		goto msg_full;
545
546	dst = (struct udp_media_addr *)&b->bcast_addr.value;
547	if (__tipc_nl_add_udp_addr(msg->skb, dst, TIPC_NLA_UDP_REMOTE))
548		goto msg_full;
549
550	if (!list_empty(&ub->rcast.list)) {
551		if (nla_put_flag(msg->skb, TIPC_NLA_UDP_MULTI_REMOTEIP))
552			goto msg_full;
553	}
554
555	nla_nest_end(msg->skb, nest);
556	return 0;
557msg_full:
558	nla_nest_cancel(msg->skb, nest);
559	return -EMSGSIZE;
560}
561
562/**
563 * tipc_parse_udp_addr - build udp media address from netlink data
564 * @nlattr:	netlink attribute containing sockaddr storage aligned address
565 * @addr:	tipc media address to fill with address, port and protocol type
566 * @scope_id:	IPv6 scope id pointer, not NULL indicates it's required
567 */
568
569static int tipc_parse_udp_addr(struct nlattr *nla, struct udp_media_addr *addr,
570			       u32 *scope_id)
571{
572	struct sockaddr_storage sa;
573
574	nla_memcpy(&sa, nla, sizeof(sa));
575	if (sa.ss_family == AF_INET) {
576		struct sockaddr_in *ip4 = (struct sockaddr_in *)&sa;
577
578		addr->proto = htons(ETH_P_IP);
579		addr->port = ip4->sin_port;
580		addr->ipv4.s_addr = ip4->sin_addr.s_addr;
581		return 0;
582
583#if IS_ENABLED(CONFIG_IPV6)
584	} else if (sa.ss_family == AF_INET6) {
585		struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)&sa;
586
587		addr->proto = htons(ETH_P_IPV6);
588		addr->port = ip6->sin6_port;
589		memcpy(&addr->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr));
590
591		/* Scope ID is only interesting for local addresses */
592		if (scope_id) {
593			int atype;
594
595			atype = ipv6_addr_type(&ip6->sin6_addr);
596			if (__ipv6_addr_needs_scope_id(atype) &&
597			    !ip6->sin6_scope_id) {
598				return -EINVAL;
599			}
600
601			*scope_id = ip6->sin6_scope_id ? : 0;
602		}
603
 
 
 
 
 
 
 
 
 
604		return 0;
605#endif
606	}
607	return -EADDRNOTAVAIL;
608}
609
610int tipc_udp_nl_bearer_add(struct tipc_bearer *b, struct nlattr *attr)
611{
612	int err;
613	struct udp_media_addr addr = {0};
614	struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
615	struct udp_media_addr *dst;
616
617	if (nla_parse_nested_deprecated(opts, TIPC_NLA_UDP_MAX, attr, tipc_nl_udp_policy, NULL))
618		return -EINVAL;
619
620	if (!opts[TIPC_NLA_UDP_REMOTE])
621		return -EINVAL;
622
623	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &addr, NULL);
624	if (err)
625		return err;
626
627	dst = (struct udp_media_addr *)&b->bcast_addr.value;
628	if (tipc_udp_is_mcast_addr(dst)) {
629		pr_err("Can't add remote ip to TIPC UDP multicast bearer\n");
630		return -EINVAL;
631	}
632
633	if (tipc_udp_is_known_peer(b, &addr))
634		return 0;
635
636	return tipc_udp_rcast_add(b, &addr);
637}
638
639/**
640 * tipc_udp_enable - callback to create a new udp bearer instance
641 * @net:	network namespace
642 * @b:		pointer to generic tipc_bearer
643 * @attrs:	netlink bearer configuration
644 *
645 * validate the bearer parameters and initialize the udp bearer
646 * rtnl_lock should be held
647 */
648static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
649			   struct nlattr *attrs[])
650{
651	int err = -EINVAL;
652	struct udp_bearer *ub;
653	struct udp_media_addr remote = {0};
654	struct udp_media_addr local = {0};
655	struct udp_port_cfg udp_conf = {0};
656	struct udp_tunnel_sock_cfg tuncfg = {NULL};
657	struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
658	u8 node_id[NODE_ID_LEN] = {0,};
659	int rmcast = 0;
660
661	ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
662	if (!ub)
663		return -ENOMEM;
664
665	INIT_LIST_HEAD(&ub->rcast.list);
666
667	if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
668		goto err;
669
670	if (nla_parse_nested_deprecated(opts, TIPC_NLA_UDP_MAX, attrs[TIPC_NLA_BEARER_UDP_OPTS], tipc_nl_udp_policy, NULL))
671		goto err;
672
673	if (!opts[TIPC_NLA_UDP_LOCAL] || !opts[TIPC_NLA_UDP_REMOTE]) {
674		pr_err("Invalid UDP bearer configuration");
675		err = -EINVAL;
676		goto err;
677	}
678
679	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_LOCAL], &local,
680				  &ub->ifindex);
681	if (err)
682		goto err;
683
684	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &remote, NULL);
685	if (err)
686		goto err;
687
688	if (remote.proto != local.proto) {
689		err = -EINVAL;
690		goto err;
691	}
692
693	/* Checking remote ip address */
694	rmcast = tipc_udp_is_mcast_addr(&remote);
695
696	/* Autoconfigure own node identity if needed */
697	if (!tipc_own_id(net)) {
698		memcpy(node_id, local.ipv6.in6_u.u6_addr8, 16);
699		tipc_net_init(net, node_id, 0);
700	}
701	if (!tipc_own_id(net)) {
702		pr_warn("Failed to set node id, please configure manually\n");
703		err = -EINVAL;
704		goto err;
705	}
706
707	b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP;
708	b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
709	rcu_assign_pointer(b->media_ptr, ub);
710	rcu_assign_pointer(ub->bearer, b);
711	tipc_udp_media_addr_set(&b->addr, &local);
712	if (local.proto == htons(ETH_P_IP)) {
713		struct net_device *dev;
714
715		dev = __ip_dev_find(net, local.ipv4.s_addr, false);
716		if (!dev) {
717			err = -ENODEV;
718			goto err;
719		}
720		udp_conf.family = AF_INET;
721
722		/* Switch to use ANY to receive packets from group */
723		if (rmcast)
724			udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
725		else
726			udp_conf.local_ip.s_addr = local.ipv4.s_addr;
727		udp_conf.use_udp_checksums = false;
728		ub->ifindex = dev->ifindex;
729		if (tipc_mtu_bad(dev, sizeof(struct iphdr) +
730				      sizeof(struct udphdr))) {
731			err = -EINVAL;
732			goto err;
733		}
734		b->mtu = b->media->mtu;
735#if IS_ENABLED(CONFIG_IPV6)
736	} else if (local.proto == htons(ETH_P_IPV6)) {
737		udp_conf.family = AF_INET6;
738		udp_conf.use_udp6_tx_checksums = true;
739		udp_conf.use_udp6_rx_checksums = true;
740		if (rmcast)
741			udp_conf.local_ip6 = in6addr_any;
742		else
743			udp_conf.local_ip6 = local.ipv6;
744		b->mtu = 1280;
745#endif
746	} else {
747		err = -EAFNOSUPPORT;
748		goto err;
749	}
750	udp_conf.local_udp_port = local.port;
751	err = udp_sock_create(net, &udp_conf, &ub->ubsock);
752	if (err)
753		goto err;
754	tuncfg.sk_user_data = ub;
755	tuncfg.encap_type = 1;
756	tuncfg.encap_rcv = tipc_udp_recv;
757	tuncfg.encap_destroy = NULL;
758	setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg);
759
760	err = dst_cache_init(&ub->rcast.dst_cache, GFP_ATOMIC);
761	if (err)
762		goto free;
763
764	/**
765	 * The bcast media address port is used for all peers and the ip
766	 * is used if it's a multicast address.
767	 */
768	memcpy(&b->bcast_addr.value, &remote, sizeof(remote));
769	if (rmcast)
770		err = enable_mcast(ub, &remote);
771	else
772		err = tipc_udp_rcast_add(b, &remote);
773	if (err)
774		goto free;
775
776	return 0;
777
778free:
779	dst_cache_destroy(&ub->rcast.dst_cache);
780	udp_tunnel_sock_release(ub->ubsock);
781err:
782	kfree(ub);
783	return err;
784}
785
786/* cleanup_bearer - break the socket/bearer association */
787static void cleanup_bearer(struct work_struct *work)
788{
789	struct udp_bearer *ub = container_of(work, struct udp_bearer, work);
790	struct udp_replicast *rcast, *tmp;
791
792	list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
793		dst_cache_destroy(&rcast->dst_cache);
794		list_del_rcu(&rcast->list);
795		kfree_rcu(rcast, rcu);
796	}
797
798	dst_cache_destroy(&ub->rcast.dst_cache);
799	udp_tunnel_sock_release(ub->ubsock);
800	synchronize_net();
801	kfree(ub);
802}
803
804/* tipc_udp_disable - detach bearer from socket */
805static void tipc_udp_disable(struct tipc_bearer *b)
806{
807	struct udp_bearer *ub;
808
809	ub = rtnl_dereference(b->media_ptr);
810	if (!ub) {
811		pr_err("UDP bearer instance not found\n");
812		return;
813	}
814	sock_set_flag(ub->ubsock->sk, SOCK_DEAD);
 
815	RCU_INIT_POINTER(ub->bearer, NULL);
816
817	/* sock_release need to be done outside of rtnl lock */
818	INIT_WORK(&ub->work, cleanup_bearer);
819	schedule_work(&ub->work);
820}
821
822struct tipc_media udp_media_info = {
823	.send_msg	= tipc_udp_send_msg,
824	.enable_media	= tipc_udp_enable,
825	.disable_media	= tipc_udp_disable,
826	.addr2str	= tipc_udp_addr2str,
827	.addr2msg	= tipc_udp_addr2msg,
828	.msg2addr	= tipc_udp_msg2addr,
829	.priority	= TIPC_DEF_LINK_PRI,
830	.tolerance	= TIPC_DEF_LINK_TOL,
831	.window		= TIPC_DEF_LINK_WIN,
832	.mtu		= TIPC_DEF_LINK_UDP_MTU,
833	.type_id	= TIPC_MEDIA_TYPE_UDP,
834	.hwaddr_len	= 0,
835	.name		= "udp"
836};