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;
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
218tx_error:
219	local_bh_enable();
220	kfree_skb(skb);
221	return err;
222}
223
224static 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;
267out:
268	kfree_skb(skb);
269	return err;
270}
271
272static 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
292static 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
324static 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 */
362static 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
393out:
394	kfree_skb(skb);
395	return 0;
396}
397
398static 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
417static 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
446int 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);
521count:
522		i++;
523	}
524done:
525	rtnl_unlock();
526	cb->args[0] = bid;
527	cb->args[1] = i;
528
529	return skb->len;
530}
531
532int 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;
561msg_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 * @nla:	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
573static 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
614int 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 */
652static 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	struct net_device *dev;
664	int rmcast = 0;
665
666	ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
667	if (!ub)
668		return -ENOMEM;
669
670	INIT_LIST_HEAD(&ub->rcast.list);
671
672	if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
673		goto err;
674
675	if (nla_parse_nested_deprecated(opts, TIPC_NLA_UDP_MAX, attrs[TIPC_NLA_BEARER_UDP_OPTS], tipc_nl_udp_policy, NULL))
676		goto err;
677
678	if (!opts[TIPC_NLA_UDP_LOCAL] || !opts[TIPC_NLA_UDP_REMOTE]) {
679		pr_err("Invalid UDP bearer configuration");
680		err = -EINVAL;
681		goto err;
682	}
683
684	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_LOCAL], &local,
685				  &ub->ifindex);
686	if (err)
687		goto err;
688
689	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &remote, NULL);
690	if (err)
691		goto err;
692
693	if (remote.proto != local.proto) {
694		err = -EINVAL;
695		goto err;
696	}
697
698	/* Checking remote ip address */
699	rmcast = tipc_udp_is_mcast_addr(&remote);
700
701	/* Autoconfigure own node identity if needed */
702	if (!tipc_own_id(net)) {
703		memcpy(node_id, local.ipv6.in6_u.u6_addr8, 16);
704		tipc_net_init(net, node_id, 0);
705	}
706	if (!tipc_own_id(net)) {
707		pr_warn("Failed to set node id, please configure manually\n");
708		err = -EINVAL;
709		goto err;
710	}
711
712	b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP;
713	b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
714	rcu_assign_pointer(b->media_ptr, ub);
715	rcu_assign_pointer(ub->bearer, b);
716	tipc_udp_media_addr_set(&b->addr, &local);
717	if (local.proto == htons(ETH_P_IP)) {
 
 
718		dev = __ip_dev_find(net, local.ipv4.s_addr, false);
719		if (!dev) {
720			err = -ENODEV;
721			goto err;
722		}
723		udp_conf.family = AF_INET;
724
725		/* Switch to use ANY to receive packets from group */
726		if (rmcast)
727			udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
728		else
729			udp_conf.local_ip.s_addr = local.ipv4.s_addr;
730		udp_conf.use_udp_checksums = false;
731		ub->ifindex = dev->ifindex;
732		if (tipc_mtu_bad(dev, sizeof(struct iphdr) +
733				      sizeof(struct udphdr))) {
734			err = -EINVAL;
735			goto err;
736		}
737		b->mtu = b->media->mtu;
738#if IS_ENABLED(CONFIG_IPV6)
739	} else if (local.proto == htons(ETH_P_IPV6)) {
740		dev = ub->ifindex ? __dev_get_by_index(net, ub->ifindex) : NULL;
741		dev = ipv6_dev_find(net, &local.ipv6, dev);
742		if (!dev) {
743			err = -ENODEV;
744			goto err;
745		}
746		udp_conf.family = AF_INET6;
747		udp_conf.use_udp6_tx_checksums = true;
748		udp_conf.use_udp6_rx_checksums = true;
749		if (rmcast)
750			udp_conf.local_ip6 = in6addr_any;
751		else
752			udp_conf.local_ip6 = local.ipv6;
753		ub->ifindex = dev->ifindex;
754		b->mtu = 1280;
755#endif
756	} else {
757		err = -EAFNOSUPPORT;
758		goto err;
759	}
760	udp_conf.local_udp_port = local.port;
761	err = udp_sock_create(net, &udp_conf, &ub->ubsock);
762	if (err)
763		goto err;
764	tuncfg.sk_user_data = ub;
765	tuncfg.encap_type = 1;
766	tuncfg.encap_rcv = tipc_udp_recv;
767	tuncfg.encap_destroy = NULL;
768	setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg);
769
770	err = dst_cache_init(&ub->rcast.dst_cache, GFP_ATOMIC);
771	if (err)
772		goto free;
773
774	/**
775	 * The bcast media address port is used for all peers and the ip
776	 * is used if it's a multicast address.
777	 */
778	memcpy(&b->bcast_addr.value, &remote, sizeof(remote));
779	if (rmcast)
780		err = enable_mcast(ub, &remote);
781	else
782		err = tipc_udp_rcast_add(b, &remote);
783	if (err)
784		goto free;
785
786	return 0;
787
788free:
789	dst_cache_destroy(&ub->rcast.dst_cache);
790	udp_tunnel_sock_release(ub->ubsock);
791err:
792	kfree(ub);
793	return err;
794}
795
796/* cleanup_bearer - break the socket/bearer association */
797static void cleanup_bearer(struct work_struct *work)
798{
799	struct udp_bearer *ub = container_of(work, struct udp_bearer, work);
800	struct udp_replicast *rcast, *tmp;
801
802	list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
803		dst_cache_destroy(&rcast->dst_cache);
804		list_del_rcu(&rcast->list);
805		kfree_rcu(rcast, rcu);
806	}
807
808	dst_cache_destroy(&ub->rcast.dst_cache);
809	udp_tunnel_sock_release(ub->ubsock);
810	synchronize_net();
811	kfree(ub);
812}
813
814/* tipc_udp_disable - detach bearer from socket */
815static void tipc_udp_disable(struct tipc_bearer *b)
816{
817	struct udp_bearer *ub;
818
819	ub = rtnl_dereference(b->media_ptr);
820	if (!ub) {
821		pr_err("UDP bearer instance not found\n");
822		return;
823	}
824	sock_set_flag(ub->ubsock->sk, SOCK_DEAD);
 
825	RCU_INIT_POINTER(ub->bearer, NULL);
826
827	/* sock_release need to be done outside of rtnl lock */
828	INIT_WORK(&ub->work, cleanup_bearer);
829	schedule_work(&ub->work);
830}
831
832struct tipc_media udp_media_info = {
833	.send_msg	= tipc_udp_send_msg,
834	.enable_media	= tipc_udp_enable,
835	.disable_media	= tipc_udp_disable,
836	.addr2str	= tipc_udp_addr2str,
837	.addr2msg	= tipc_udp_addr2msg,
838	.msg2addr	= tipc_udp_msg2addr,
839	.priority	= TIPC_DEF_LINK_PRI,
840	.tolerance	= TIPC_DEF_LINK_TOL,
841	.min_win	= TIPC_DEF_LINK_WIN,
842	.max_win	= TIPC_DEF_LINK_WIN,
843	.mtu		= TIPC_DEF_LINK_UDP_MTU,
844	.type_id	= TIPC_MEDIA_TYPE_UDP,
845	.hwaddr_len	= 0,
846	.name		= "udp"
847};