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  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/addrconf.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 rcu_head rcu;
 80	struct list_head list;
 81};
 82
 83/**
 84 * struct udp_bearer - ip/udp bearer data structure
 85 * @bearer:	associated generic tipc bearer
 86 * @ubsock:	bearer associated socket
 87 * @ifindex:	local address scope
 88 * @work:	used to schedule deferred work on a bearer
 89 */
 90struct udp_bearer {
 91	struct tipc_bearer __rcu *bearer;
 92	struct socket *ubsock;
 93	u32 ifindex;
 94	struct work_struct work;
 95	struct udp_replicast rcast;
 96};
 97
 98static int tipc_udp_is_mcast_addr(struct udp_media_addr *addr)
 99{
100	if (ntohs(addr->proto) == ETH_P_IP)
101		return ipv4_is_multicast(addr->ipv4.s_addr);
102#if IS_ENABLED(CONFIG_IPV6)
103	else
104		return ipv6_addr_is_multicast(&addr->ipv6);
105#endif
106	return 0;
107}
108
109/* udp_media_addr_set - convert a ip/udp address to a TIPC media address */
110static void tipc_udp_media_addr_set(struct tipc_media_addr *addr,
111				    struct udp_media_addr *ua)
112{
113	memset(addr, 0, sizeof(struct tipc_media_addr));
114	addr->media_id = TIPC_MEDIA_TYPE_UDP;
115	memcpy(addr->value, ua, sizeof(struct udp_media_addr));
116
117	if (tipc_udp_is_mcast_addr(ua))
118		addr->broadcast = TIPC_BROADCAST_SUPPORT;
119}
120
121/* tipc_udp_addr2str - convert ip/udp address to string */
122static int tipc_udp_addr2str(struct tipc_media_addr *a, char *buf, int size)
123{
124	struct udp_media_addr *ua = (struct udp_media_addr *)&a->value;
125
126	if (ntohs(ua->proto) == ETH_P_IP)
127		snprintf(buf, size, "%pI4:%u", &ua->ipv4, ntohs(ua->port));
128	else if (ntohs(ua->proto) == ETH_P_IPV6)
129		snprintf(buf, size, "%pI6:%u", &ua->ipv6, ntohs(ua->port));
130	else
131		pr_err("Invalid UDP media address\n");
132	return 0;
133}
134
135/* tipc_udp_msg2addr - extract an ip/udp address from a TIPC ndisc message */
136static int tipc_udp_msg2addr(struct tipc_bearer *b, struct tipc_media_addr *a,
137			     char *msg)
138{
139	struct udp_media_addr *ua;
140
141	ua = (struct udp_media_addr *) (msg + TIPC_MEDIA_ADDR_OFFSET);
142	if (msg[TIPC_MEDIA_TYPE_OFFSET] != TIPC_MEDIA_TYPE_UDP)
143		return -EINVAL;
144	tipc_udp_media_addr_set(a, ua);
145	return 0;
146}
147
148/* tipc_udp_addr2msg - write an ip/udp address to a TIPC ndisc message */
149static int tipc_udp_addr2msg(char *msg, struct tipc_media_addr *a)
150{
151	memset(msg, 0, TIPC_MEDIA_INFO_SIZE);
152	msg[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_UDP;
153	memcpy(msg + TIPC_MEDIA_ADDR_OFFSET, a->value,
154	       sizeof(struct udp_media_addr));
155	return 0;
156}
157
158/* tipc_send_msg - enqueue a send request */
159static int tipc_udp_xmit(struct net *net, struct sk_buff *skb,
160			 struct udp_bearer *ub, struct udp_media_addr *src,
161			 struct udp_media_addr *dst)
162{
163	int ttl, err = 0;
164	struct rtable *rt;
165
166	if (dst->proto == htons(ETH_P_IP)) {
167		struct flowi4 fl = {
168			.daddr = dst->ipv4.s_addr,
169			.saddr = src->ipv4.s_addr,
170			.flowi4_mark = skb->mark,
171			.flowi4_proto = IPPROTO_UDP
172		};
173		rt = ip_route_output_key(net, &fl);
174		if (IS_ERR(rt)) {
175			err = PTR_ERR(rt);
176			goto tx_error;
177		}
178
179		skb->dev = rt->dst.dev;
180		ttl = ip4_dst_hoplimit(&rt->dst);
181		udp_tunnel_xmit_skb(rt, ub->ubsock->sk, skb, src->ipv4.s_addr,
182				    dst->ipv4.s_addr, 0, ttl, 0, src->port,
183				    dst->port, false, true);
184#if IS_ENABLED(CONFIG_IPV6)
185	} else {
186		struct dst_entry *ndst;
187		struct flowi6 fl6 = {
188			.flowi6_oif = ub->ifindex,
189			.daddr = dst->ipv6,
190			.saddr = src->ipv6,
191			.flowi6_proto = IPPROTO_UDP
192		};
193		err = ipv6_stub->ipv6_dst_lookup(net, ub->ubsock->sk, &ndst,
194						 &fl6);
195		if (err)
196			goto tx_error;
197		ttl = ip6_dst_hoplimit(ndst);
198		err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb,
199					   ndst->dev, &src->ipv6,
200					   &dst->ipv6, 0, ttl, 0, src->port,
201					   dst->port, false);
202#endif
203	}
204	return err;
205
206tx_error:
207	kfree_skb(skb);
208	return err;
209}
210
211static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
212			     struct tipc_bearer *b,
213			     struct tipc_media_addr *addr)
214{
215	struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
216	struct udp_media_addr *dst = (struct udp_media_addr *)&addr->value;
217	struct udp_replicast *rcast;
218	struct udp_bearer *ub;
219	int err = 0;
220
221	if (skb_headroom(skb) < UDP_MIN_HEADROOM) {
222		err = pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC);
223		if (err)
224			goto out;
225	}
226
227	skb_set_inner_protocol(skb, htons(ETH_P_TIPC));
228	ub = rcu_dereference_rtnl(b->media_ptr);
229	if (!ub) {
230		err = -ENODEV;
231		goto out;
232	}
233
234	if (addr->broadcast != TIPC_REPLICAST_SUPPORT)
235		return tipc_udp_xmit(net, skb, ub, src, dst);
236
237	/* Replicast, send an skb to each configured IP address */
238	list_for_each_entry_rcu(rcast, &ub->rcast.list, list) {
239		struct sk_buff *_skb;
240
241		_skb = pskb_copy(skb, GFP_ATOMIC);
242		if (!_skb) {
243			err = -ENOMEM;
244			goto out;
245		}
246
247		err = tipc_udp_xmit(net, _skb, ub, src, &rcast->addr);
248		if (err) {
249			kfree_skb(_skb);
250			goto out;
251		}
252	}
253	err = 0;
254out:
255	kfree_skb(skb);
256	return err;
257}
258
259static bool tipc_udp_is_known_peer(struct tipc_bearer *b,
260				   struct udp_media_addr *addr)
261{
262	struct udp_replicast *rcast, *tmp;
263	struct udp_bearer *ub;
264
265	ub = rcu_dereference_rtnl(b->media_ptr);
266	if (!ub) {
267		pr_err_ratelimited("UDP bearer instance not found\n");
268		return false;
269	}
270
271	list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
272		if (!memcmp(&rcast->addr, addr, sizeof(struct udp_media_addr)))
273			return true;
274	}
275
276	return false;
277}
278
279static int tipc_udp_rcast_add(struct tipc_bearer *b,
280			      struct udp_media_addr *addr)
281{
282	struct udp_replicast *rcast;
283	struct udp_bearer *ub;
284
285	ub = rcu_dereference_rtnl(b->media_ptr);
286	if (!ub)
287		return -ENODEV;
288
289	rcast = kmalloc(sizeof(*rcast), GFP_ATOMIC);
290	if (!rcast)
291		return -ENOMEM;
292
293	memcpy(&rcast->addr, addr, sizeof(struct udp_media_addr));
294
295	if (ntohs(addr->proto) == ETH_P_IP)
296		pr_info("New replicast peer: %pI4\n", &rcast->addr.ipv4);
297#if IS_ENABLED(CONFIG_IPV6)
298	else if (ntohs(addr->proto) == ETH_P_IPV6)
299		pr_info("New replicast peer: %pI6\n", &rcast->addr.ipv6);
300#endif
301	b->bcast_addr.broadcast = TIPC_REPLICAST_SUPPORT;
302	list_add_rcu(&rcast->list, &ub->rcast.list);
303	return 0;
304}
305
306static int tipc_udp_rcast_disc(struct tipc_bearer *b, struct sk_buff *skb)
307{
308	struct udp_media_addr src = {0};
309	struct udp_media_addr *dst;
310
311	dst = (struct udp_media_addr *)&b->bcast_addr.value;
312	if (tipc_udp_is_mcast_addr(dst))
313		return 0;
314
315	src.port = udp_hdr(skb)->source;
316
317	if (ip_hdr(skb)->version == 4) {
318		struct iphdr *iphdr = ip_hdr(skb);
319
320		src.proto = htons(ETH_P_IP);
321		src.ipv4.s_addr = iphdr->saddr;
322		if (ipv4_is_multicast(iphdr->daddr))
323			return 0;
324#if IS_ENABLED(CONFIG_IPV6)
325	} else if (ip_hdr(skb)->version == 6) {
326		struct ipv6hdr *iphdr = ipv6_hdr(skb);
327
328		src.proto = htons(ETH_P_IPV6);
329		src.ipv6 = iphdr->saddr;
330		if (ipv6_addr_is_multicast(&iphdr->daddr))
331			return 0;
332#endif
333	} else {
334		return 0;
335	}
336
337	if (likely(tipc_udp_is_known_peer(b, &src)))
338		return 0;
339
340	return tipc_udp_rcast_add(b, &src);
341}
342
343/* tipc_udp_recv - read data from bearer socket */
344static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb)
345{
346	struct udp_bearer *ub;
347	struct tipc_bearer *b;
348	struct tipc_msg *hdr;
349	int err;
350
351	ub = rcu_dereference_sk_user_data(sk);
352	if (!ub) {
353		pr_err_ratelimited("Failed to get UDP bearer reference");
354		goto out;
355	}
356	skb_pull(skb, sizeof(struct udphdr));
357	hdr = buf_msg(skb);
358
359	rcu_read_lock();
360	b = rcu_dereference_rtnl(ub->bearer);
361	if (!b)
362		goto rcu_out;
363
364	if (b && test_bit(0, &b->up)) {
365		tipc_rcv(sock_net(sk), skb, b);
366		rcu_read_unlock();
367		return 0;
368	}
369
370	if (unlikely(msg_user(hdr) == LINK_CONFIG)) {
371		err = tipc_udp_rcast_disc(b, skb);
372		if (err)
373			goto rcu_out;
374	}
375
376rcu_out:
377	rcu_read_unlock();
378out:
379	kfree_skb(skb);
380	return 0;
381}
382
383static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote)
384{
385	int err = 0;
386	struct ip_mreqn mreqn;
387	struct sock *sk = ub->ubsock->sk;
388
389	if (ntohs(remote->proto) == ETH_P_IP) {
390		mreqn.imr_multiaddr = remote->ipv4;
391		mreqn.imr_ifindex = ub->ifindex;
392		err = ip_mc_join_group(sk, &mreqn);
393#if IS_ENABLED(CONFIG_IPV6)
394	} else {
395		err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex,
396						   &remote->ipv6);
397#endif
398	}
399	return err;
400}
401
402static int __tipc_nl_add_udp_addr(struct sk_buff *skb,
403				  struct udp_media_addr *addr, int nla_t)
404{
405	if (ntohs(addr->proto) == ETH_P_IP) {
406		struct sockaddr_in ip4;
407
408		memset(&ip4, 0, sizeof(ip4));
409		ip4.sin_family = AF_INET;
410		ip4.sin_port = addr->port;
411		ip4.sin_addr.s_addr = addr->ipv4.s_addr;
412		if (nla_put(skb, nla_t, sizeof(ip4), &ip4))
413			return -EMSGSIZE;
414
415#if IS_ENABLED(CONFIG_IPV6)
416	} else if (ntohs(addr->proto) == ETH_P_IPV6) {
417		struct sockaddr_in6 ip6;
418
419		memset(&ip6, 0, sizeof(ip6));
420		ip6.sin6_family = AF_INET6;
421		ip6.sin6_port  = addr->port;
422		memcpy(&ip6.sin6_addr, &addr->ipv6, sizeof(struct in6_addr));
423		if (nla_put(skb, nla_t, sizeof(ip6), &ip6))
424			return -EMSGSIZE;
425#endif
426	}
427
428	return 0;
429}
430
431int tipc_udp_nl_dump_remoteip(struct sk_buff *skb, struct netlink_callback *cb)
432{
433	u32 bid = cb->args[0];
434	u32 skip_cnt = cb->args[1];
435	u32 portid = NETLINK_CB(cb->skb).portid;
436	struct udp_replicast *rcast, *tmp;
437	struct tipc_bearer *b;
438	struct udp_bearer *ub;
439	void *hdr;
440	int err;
441	int i;
442
443	if (!bid && !skip_cnt) {
444		struct net *net = sock_net(skb->sk);
445		struct nlattr *battrs[TIPC_NLA_BEARER_MAX + 1];
446		struct nlattr **attrs;
447		char *bname;
448
449		err = tipc_nlmsg_parse(cb->nlh, &attrs);
450		if (err)
451			return err;
452
453		if (!attrs[TIPC_NLA_BEARER])
454			return -EINVAL;
455
456		err = nla_parse_nested(battrs, TIPC_NLA_BEARER_MAX,
457				       attrs[TIPC_NLA_BEARER],
458				       tipc_nl_bearer_policy, NULL);
459		if (err)
460			return err;
461
462		if (!battrs[TIPC_NLA_BEARER_NAME])
463			return -EINVAL;
464
465		bname = nla_data(battrs[TIPC_NLA_BEARER_NAME]);
466
467		rtnl_lock();
468		b = tipc_bearer_find(net, bname);
469		if (!b) {
470			rtnl_unlock();
471			return -EINVAL;
472		}
473		bid = b->identity;
474	} else {
475		struct net *net = sock_net(skb->sk);
476		struct tipc_net *tn = net_generic(net, tipc_net_id);
477
478		rtnl_lock();
479		b = rtnl_dereference(tn->bearer_list[bid]);
480		if (!b) {
481			rtnl_unlock();
482			return -EINVAL;
483		}
484	}
485
486	ub = rcu_dereference_rtnl(b->media_ptr);
487	if (!ub) {
488		rtnl_unlock();
489		return -EINVAL;
490	}
491
492	i = 0;
493	list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
494		if (i < skip_cnt)
495			goto count;
496
497		hdr = genlmsg_put(skb, portid, cb->nlh->nlmsg_seq,
498				  &tipc_genl_family, NLM_F_MULTI,
499				  TIPC_NL_BEARER_GET);
500		if (!hdr)
501			goto done;
502
503		err = __tipc_nl_add_udp_addr(skb, &rcast->addr,
504					     TIPC_NLA_UDP_REMOTE);
505		if (err) {
506			genlmsg_cancel(skb, hdr);
507			goto done;
508		}
509		genlmsg_end(skb, hdr);
510count:
511		i++;
512	}
513done:
514	rtnl_unlock();
515	cb->args[0] = bid;
516	cb->args[1] = i;
517
518	return skb->len;
519}
520
521int tipc_udp_nl_add_bearer_data(struct tipc_nl_msg *msg, struct tipc_bearer *b)
522{
523	struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
524	struct udp_media_addr *dst;
525	struct udp_bearer *ub;
526	struct nlattr *nest;
527
528	ub = rcu_dereference_rtnl(b->media_ptr);
529	if (!ub)
530		return -ENODEV;
531
532	nest = nla_nest_start(msg->skb, TIPC_NLA_BEARER_UDP_OPTS);
533	if (!nest)
534		goto msg_full;
535
536	if (__tipc_nl_add_udp_addr(msg->skb, src, TIPC_NLA_UDP_LOCAL))
537		goto msg_full;
538
539	dst = (struct udp_media_addr *)&b->bcast_addr.value;
540	if (__tipc_nl_add_udp_addr(msg->skb, dst, TIPC_NLA_UDP_REMOTE))
541		goto msg_full;
542
543	if (!list_empty(&ub->rcast.list)) {
544		if (nla_put_flag(msg->skb, TIPC_NLA_UDP_MULTI_REMOTEIP))
545			goto msg_full;
546	}
547
548	nla_nest_end(msg->skb, nest);
549	return 0;
550msg_full:
551	nla_nest_cancel(msg->skb, nest);
552	return -EMSGSIZE;
553}
554
555/**
556 * tipc_parse_udp_addr - build udp media address from netlink data
557 * @nlattr:	netlink attribute containing sockaddr storage aligned address
558 * @addr:	tipc media address to fill with address, port and protocol type
559 * @scope_id:	IPv6 scope id pointer, not NULL indicates it's required
560 */
561
562static int tipc_parse_udp_addr(struct nlattr *nla, struct udp_media_addr *addr,
563			       u32 *scope_id)
564{
565	struct sockaddr_storage sa;
566
567	nla_memcpy(&sa, nla, sizeof(sa));
568	if (sa.ss_family == AF_INET) {
569		struct sockaddr_in *ip4 = (struct sockaddr_in *)&sa;
570
571		addr->proto = htons(ETH_P_IP);
572		addr->port = ip4->sin_port;
573		addr->ipv4.s_addr = ip4->sin_addr.s_addr;
574		return 0;
575
576#if IS_ENABLED(CONFIG_IPV6)
577	} else if (sa.ss_family == AF_INET6) {
578		struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)&sa;
579
580		addr->proto = htons(ETH_P_IPV6);
581		addr->port = ip6->sin6_port;
582		memcpy(&addr->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr));
583
584		/* Scope ID is only interesting for local addresses */
585		if (scope_id) {
586			int atype;
587
588			atype = ipv6_addr_type(&ip6->sin6_addr);
589			if (__ipv6_addr_needs_scope_id(atype) &&
590			    !ip6->sin6_scope_id) {
591				return -EINVAL;
592			}
593
594			*scope_id = ip6->sin6_scope_id ? : 0;
595		}
596
597		return 0;
598#endif
599	}
600	return -EADDRNOTAVAIL;
601}
602
603int tipc_udp_nl_bearer_add(struct tipc_bearer *b, struct nlattr *attr)
604{
605	int err;
606	struct udp_media_addr addr = {0};
607	struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
608	struct udp_media_addr *dst;
609
610	if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX, attr,
611			     tipc_nl_udp_policy, NULL))
612		return -EINVAL;
613
614	if (!opts[TIPC_NLA_UDP_REMOTE])
615		return -EINVAL;
616
617	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &addr, NULL);
618	if (err)
619		return err;
620
621	dst = (struct udp_media_addr *)&b->bcast_addr.value;
622	if (tipc_udp_is_mcast_addr(dst)) {
623		pr_err("Can't add remote ip to TIPC UDP multicast bearer\n");
624		return -EINVAL;
625	}
626
627	if (tipc_udp_is_known_peer(b, &addr))
628		return 0;
629
630	return tipc_udp_rcast_add(b, &addr);
631}
632
633/**
634 * tipc_udp_enable - callback to create a new udp bearer instance
635 * @net:	network namespace
636 * @b:		pointer to generic tipc_bearer
637 * @attrs:	netlink bearer configuration
638 *
639 * validate the bearer parameters and initialize the udp bearer
640 * rtnl_lock should be held
641 */
642static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
643			   struct nlattr *attrs[])
644{
645	int err = -EINVAL;
646	struct udp_bearer *ub;
647	struct udp_media_addr remote = {0};
648	struct udp_media_addr local = {0};
649	struct udp_port_cfg udp_conf = {0};
650	struct udp_tunnel_sock_cfg tuncfg = {NULL};
651	struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
652	u8 node_id[NODE_ID_LEN] = {0,};
653
654	ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
655	if (!ub)
656		return -ENOMEM;
657
658	INIT_LIST_HEAD(&ub->rcast.list);
659
660	if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
661		goto err;
662
663	if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX,
664			     attrs[TIPC_NLA_BEARER_UDP_OPTS],
665			     tipc_nl_udp_policy, NULL))
666		goto err;
667
668	if (!opts[TIPC_NLA_UDP_LOCAL] || !opts[TIPC_NLA_UDP_REMOTE]) {
669		pr_err("Invalid UDP bearer configuration");
670		err = -EINVAL;
671		goto err;
672	}
673
674	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_LOCAL], &local,
675				  &ub->ifindex);
676	if (err)
677		goto err;
678
679	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &remote, NULL);
680	if (err)
681		goto err;
682
683	/* Autoconfigure own node identity if needed */
684	if (!tipc_own_id(net)) {
685		memcpy(node_id, local.ipv6.in6_u.u6_addr8, 16);
686		tipc_net_init(net, node_id, 0);
687	}
688	if (!tipc_own_id(net)) {
689		pr_warn("Failed to set node id, please configure manually\n");
690		err = -EINVAL;
691		goto err;
692	}
693
694	b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP;
695	b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
696	rcu_assign_pointer(b->media_ptr, ub);
697	rcu_assign_pointer(ub->bearer, b);
698	tipc_udp_media_addr_set(&b->addr, &local);
699	if (local.proto == htons(ETH_P_IP)) {
700		struct net_device *dev;
701
702		dev = __ip_dev_find(net, local.ipv4.s_addr, false);
703		if (!dev) {
704			err = -ENODEV;
705			goto err;
706		}
707		udp_conf.family = AF_INET;
708		udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
709		udp_conf.use_udp_checksums = false;
710		ub->ifindex = dev->ifindex;
711		if (tipc_mtu_bad(dev, sizeof(struct iphdr) +
712				      sizeof(struct udphdr))) {
713			err = -EINVAL;
714			goto err;
715		}
716		b->mtu = dev->mtu - sizeof(struct iphdr)
717			- sizeof(struct udphdr);
718#if IS_ENABLED(CONFIG_IPV6)
719	} else if (local.proto == htons(ETH_P_IPV6)) {
720		udp_conf.family = AF_INET6;
721		udp_conf.use_udp6_tx_checksums = true;
722		udp_conf.use_udp6_rx_checksums = true;
723		udp_conf.local_ip6 = in6addr_any;
724		b->mtu = 1280;
725#endif
726	} else {
727		err = -EAFNOSUPPORT;
728		goto err;
729	}
730	udp_conf.local_udp_port = local.port;
731	err = udp_sock_create(net, &udp_conf, &ub->ubsock);
732	if (err)
733		goto err;
734	tuncfg.sk_user_data = ub;
735	tuncfg.encap_type = 1;
736	tuncfg.encap_rcv = tipc_udp_recv;
737	tuncfg.encap_destroy = NULL;
738	setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg);
739
740	/**
741	 * The bcast media address port is used for all peers and the ip
742	 * is used if it's a multicast address.
743	 */
744	memcpy(&b->bcast_addr.value, &remote, sizeof(remote));
745	if (tipc_udp_is_mcast_addr(&remote))
746		err = enable_mcast(ub, &remote);
747	else
748		err = tipc_udp_rcast_add(b, &remote);
749	if (err)
750		goto err;
751
752	return 0;
753err:
754	if (ub->ubsock)
755		udp_tunnel_sock_release(ub->ubsock);
756	kfree(ub);
757	return err;
758}
759
760/* cleanup_bearer - break the socket/bearer association */
761static void cleanup_bearer(struct work_struct *work)
762{
763	struct udp_bearer *ub = container_of(work, struct udp_bearer, work);
764	struct udp_replicast *rcast, *tmp;
765
766	list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
767		list_del_rcu(&rcast->list);
768		kfree_rcu(rcast, rcu);
769	}
770
771	if (ub->ubsock)
772		udp_tunnel_sock_release(ub->ubsock);
773	synchronize_net();
774	kfree(ub);
775}
776
777/* tipc_udp_disable - detach bearer from socket */
778static void tipc_udp_disable(struct tipc_bearer *b)
779{
780	struct udp_bearer *ub;
781
782	ub = rcu_dereference_rtnl(b->media_ptr);
783	if (!ub) {
784		pr_err("UDP bearer instance not found\n");
785		return;
786	}
787	if (ub->ubsock)
788		sock_set_flag(ub->ubsock->sk, SOCK_DEAD);
789	RCU_INIT_POINTER(ub->bearer, NULL);
790
791	/* sock_release need to be done outside of rtnl lock */
792	INIT_WORK(&ub->work, cleanup_bearer);
793	schedule_work(&ub->work);
794}
795
796struct tipc_media udp_media_info = {
797	.send_msg	= tipc_udp_send_msg,
798	.enable_media	= tipc_udp_enable,
799	.disable_media	= tipc_udp_disable,
800	.addr2str	= tipc_udp_addr2str,
801	.addr2msg	= tipc_udp_addr2msg,
802	.msg2addr	= tipc_udp_msg2addr,
803	.priority	= TIPC_DEF_LINK_PRI,
804	.tolerance	= TIPC_DEF_LINK_TOL,
805	.window		= TIPC_DEF_LINK_WIN,
806	.type_id	= TIPC_MEDIA_TYPE_UDP,
807	.hwaddr_len	= 0,
808	.name		= "udp"
809};