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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/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 #include "udp_media.h"
56 
57 /* IANA assigned UDP port */
58 #define UDP_PORT_DEFAULT	6118
59 
60 #define UDP_MIN_HEADROOM        48
61 
62 /**
63  * struct udp_media_addr - IP/UDP addressing information
64  *
65  * This is the bearer level originating address used in neighbor discovery
66  * messages, and all fields should be in network byte order
67  *
68  * @proto: Ethernet protocol in use
69  * @port: port being used
70  * @ipv4: IPv4 address of neighbor
71  * @ipv6: IPv6 address of neighbor
72  */
73 struct udp_media_addr {
74 	__be16	proto;
75 	__be16	port;
76 	union {
77 		struct in_addr ipv4;
78 		struct in6_addr ipv6;
79 	};
80 };
81 
82 /* struct udp_replicast - container for UDP remote addresses */
83 struct udp_replicast {
84 	struct udp_media_addr addr;
85 	struct dst_cache dst_cache;
86 	struct rcu_head rcu;
87 	struct list_head list;
88 };
89 
90 /**
91  * struct udp_bearer - ip/udp bearer data structure
92  * @bearer:	associated generic tipc bearer
93  * @ubsock:	bearer associated socket
94  * @ifindex:	local address scope
95  * @work:	used to schedule deferred work on a bearer
96  * @rcast:	associated udp_replicast container
97  */
98 struct udp_bearer {
99 	struct tipc_bearer __rcu *bearer;
100 	struct socket *ubsock;
101 	u32 ifindex;
102 	struct work_struct work;
103 	struct udp_replicast rcast;
104 };
105 
tipc_udp_is_mcast_addr(struct udp_media_addr * addr)106 static int tipc_udp_is_mcast_addr(struct udp_media_addr *addr)
107 {
108 	if (ntohs(addr->proto) == ETH_P_IP)
109 		return ipv4_is_multicast(addr->ipv4.s_addr);
110 #if IS_ENABLED(CONFIG_IPV6)
111 	else
112 		return ipv6_addr_is_multicast(&addr->ipv6);
113 #endif
114 	return 0;
115 }
116 
117 /* udp_media_addr_set - convert a ip/udp address to a TIPC media address */
tipc_udp_media_addr_set(struct tipc_media_addr * addr,struct udp_media_addr * ua)118 static void tipc_udp_media_addr_set(struct tipc_media_addr *addr,
119 				    struct udp_media_addr *ua)
120 {
121 	memset(addr, 0, sizeof(struct tipc_media_addr));
122 	addr->media_id = TIPC_MEDIA_TYPE_UDP;
123 	memcpy(addr->value, ua, sizeof(struct udp_media_addr));
124 
125 	if (tipc_udp_is_mcast_addr(ua))
126 		addr->broadcast = TIPC_BROADCAST_SUPPORT;
127 }
128 
129 /* tipc_udp_addr2str - convert ip/udp address to string */
tipc_udp_addr2str(struct tipc_media_addr * a,char * buf,int size)130 static int tipc_udp_addr2str(struct tipc_media_addr *a, char *buf, int size)
131 {
132 	struct udp_media_addr *ua = (struct udp_media_addr *)&a->value;
133 
134 	if (ntohs(ua->proto) == ETH_P_IP)
135 		snprintf(buf, size, "%pI4:%u", &ua->ipv4, ntohs(ua->port));
136 	else if (ntohs(ua->proto) == ETH_P_IPV6)
137 		snprintf(buf, size, "%pI6:%u", &ua->ipv6, ntohs(ua->port));
138 	else
139 		pr_err("Invalid UDP media address\n");
140 	return 0;
141 }
142 
143 /* tipc_udp_msg2addr - extract an ip/udp address from a TIPC ndisc message */
tipc_udp_msg2addr(struct tipc_bearer * b,struct tipc_media_addr * a,char * msg)144 static int tipc_udp_msg2addr(struct tipc_bearer *b, struct tipc_media_addr *a,
145 			     char *msg)
146 {
147 	struct udp_media_addr *ua;
148 
149 	ua = (struct udp_media_addr *) (msg + TIPC_MEDIA_ADDR_OFFSET);
150 	if (msg[TIPC_MEDIA_TYPE_OFFSET] != TIPC_MEDIA_TYPE_UDP)
151 		return -EINVAL;
152 	tipc_udp_media_addr_set(a, ua);
153 	return 0;
154 }
155 
156 /* tipc_udp_addr2msg - write an ip/udp address to a TIPC ndisc message */
tipc_udp_addr2msg(char * msg,struct tipc_media_addr * a)157 static int tipc_udp_addr2msg(char *msg, struct tipc_media_addr *a)
158 {
159 	memset(msg, 0, TIPC_MEDIA_INFO_SIZE);
160 	msg[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_UDP;
161 	memcpy(msg + TIPC_MEDIA_ADDR_OFFSET, a->value,
162 	       sizeof(struct udp_media_addr));
163 	return 0;
164 }
165 
166 /* tipc_send_msg - enqueue a send request */
tipc_udp_xmit(struct net * net,struct sk_buff * skb,struct udp_bearer * ub,struct udp_media_addr * src,struct udp_media_addr * dst,struct dst_cache * cache)167 static int tipc_udp_xmit(struct net *net, struct sk_buff *skb,
168 			 struct udp_bearer *ub, struct udp_media_addr *src,
169 			 struct udp_media_addr *dst, struct dst_cache *cache)
170 {
171 	struct dst_entry *ndst;
172 	int ttl, err = 0;
173 
174 	local_bh_disable();
175 	ndst = dst_cache_get(cache);
176 	if (dst->proto == htons(ETH_P_IP)) {
177 		struct rtable *rt = (struct rtable *)ndst;
178 
179 		if (!rt) {
180 			struct flowi4 fl = {
181 				.daddr = dst->ipv4.s_addr,
182 				.saddr = src->ipv4.s_addr,
183 				.flowi4_mark = skb->mark,
184 				.flowi4_proto = IPPROTO_UDP
185 			};
186 			rt = ip_route_output_key(net, &fl);
187 			if (IS_ERR(rt)) {
188 				err = PTR_ERR(rt);
189 				goto tx_error;
190 			}
191 			dst_cache_set_ip4(cache, &rt->dst, fl.saddr);
192 		}
193 
194 		ttl = ip4_dst_hoplimit(&rt->dst);
195 		udp_tunnel_xmit_skb(rt, ub->ubsock->sk, skb, src->ipv4.s_addr,
196 				    dst->ipv4.s_addr, 0, ttl, 0, src->port,
197 				    dst->port, false, true);
198 #if IS_ENABLED(CONFIG_IPV6)
199 	} else {
200 		if (!ndst) {
201 			struct flowi6 fl6 = {
202 				.flowi6_oif = ub->ifindex,
203 				.daddr = dst->ipv6,
204 				.saddr = src->ipv6,
205 				.flowi6_proto = IPPROTO_UDP
206 			};
207 			ndst = ipv6_stub->ipv6_dst_lookup_flow(net,
208 							       ub->ubsock->sk,
209 							       &fl6, NULL);
210 			if (IS_ERR(ndst)) {
211 				err = PTR_ERR(ndst);
212 				goto tx_error;
213 			}
214 			dst_cache_set_ip6(cache, ndst, &fl6.saddr);
215 		}
216 		ttl = ip6_dst_hoplimit(ndst);
217 		err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb, NULL,
218 					   &src->ipv6, &dst->ipv6, 0, ttl, 0,
219 					   src->port, dst->port, false);
220 #endif
221 	}
222 	local_bh_enable();
223 	return err;
224 
225 tx_error:
226 	local_bh_enable();
227 	kfree_skb(skb);
228 	return err;
229 }
230 
tipc_udp_send_msg(struct net * net,struct sk_buff * skb,struct tipc_bearer * b,struct tipc_media_addr * addr)231 static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
232 			     struct tipc_bearer *b,
233 			     struct tipc_media_addr *addr)
234 {
235 	struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
236 	struct udp_media_addr *dst = (struct udp_media_addr *)&addr->value;
237 	struct udp_replicast *rcast;
238 	struct udp_bearer *ub;
239 	int err = 0;
240 
241 	if (skb_headroom(skb) < UDP_MIN_HEADROOM) {
242 		err = pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC);
243 		if (err)
244 			goto out;
245 	}
246 
247 	skb_set_inner_protocol(skb, htons(ETH_P_TIPC));
248 	ub = rcu_dereference(b->media_ptr);
249 	if (!ub) {
250 		err = -ENODEV;
251 		goto out;
252 	}
253 
254 	if (addr->broadcast != TIPC_REPLICAST_SUPPORT)
255 		return tipc_udp_xmit(net, skb, ub, src, dst,
256 				     &ub->rcast.dst_cache);
257 
258 	/* Replicast, send an skb to each configured IP address */
259 	list_for_each_entry_rcu(rcast, &ub->rcast.list, list) {
260 		struct sk_buff *_skb;
261 
262 		_skb = pskb_copy(skb, GFP_ATOMIC);
263 		if (!_skb) {
264 			err = -ENOMEM;
265 			goto out;
266 		}
267 
268 		err = tipc_udp_xmit(net, _skb, ub, src, &rcast->addr,
269 				    &rcast->dst_cache);
270 		if (err)
271 			goto out;
272 	}
273 	err = 0;
274 out:
275 	kfree_skb(skb);
276 	return err;
277 }
278 
tipc_udp_is_known_peer(struct tipc_bearer * b,struct udp_media_addr * addr)279 static bool tipc_udp_is_known_peer(struct tipc_bearer *b,
280 				   struct udp_media_addr *addr)
281 {
282 	struct udp_replicast *rcast, *tmp;
283 	struct udp_bearer *ub;
284 
285 	ub = rcu_dereference_rtnl(b->media_ptr);
286 	if (!ub) {
287 		pr_err_ratelimited("UDP bearer instance not found\n");
288 		return false;
289 	}
290 
291 	list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
292 		if (!memcmp(&rcast->addr, addr, sizeof(struct udp_media_addr)))
293 			return true;
294 	}
295 
296 	return false;
297 }
298 
tipc_udp_rcast_add(struct tipc_bearer * b,struct udp_media_addr * addr)299 static int tipc_udp_rcast_add(struct tipc_bearer *b,
300 			      struct udp_media_addr *addr)
301 {
302 	struct udp_replicast *rcast;
303 	struct udp_bearer *ub;
304 
305 	ub = rcu_dereference_rtnl(b->media_ptr);
306 	if (!ub)
307 		return -ENODEV;
308 
309 	rcast = kmalloc(sizeof(*rcast), GFP_ATOMIC);
310 	if (!rcast)
311 		return -ENOMEM;
312 
313 	if (dst_cache_init(&rcast->dst_cache, GFP_ATOMIC)) {
314 		kfree(rcast);
315 		return -ENOMEM;
316 	}
317 
318 	memcpy(&rcast->addr, addr, sizeof(struct udp_media_addr));
319 
320 	if (ntohs(addr->proto) == ETH_P_IP)
321 		pr_info("New replicast peer: %pI4\n", &rcast->addr.ipv4);
322 #if IS_ENABLED(CONFIG_IPV6)
323 	else if (ntohs(addr->proto) == ETH_P_IPV6)
324 		pr_info("New replicast peer: %pI6\n", &rcast->addr.ipv6);
325 #endif
326 	b->bcast_addr.broadcast = TIPC_REPLICAST_SUPPORT;
327 	list_add_rcu(&rcast->list, &ub->rcast.list);
328 	return 0;
329 }
330 
tipc_udp_rcast_disc(struct tipc_bearer * b,struct sk_buff * skb)331 static int tipc_udp_rcast_disc(struct tipc_bearer *b, struct sk_buff *skb)
332 {
333 	struct udp_media_addr src = {0};
334 	struct udp_media_addr *dst;
335 
336 	dst = (struct udp_media_addr *)&b->bcast_addr.value;
337 	if (tipc_udp_is_mcast_addr(dst))
338 		return 0;
339 
340 	src.port = udp_hdr(skb)->source;
341 
342 	if (ip_hdr(skb)->version == 4) {
343 		struct iphdr *iphdr = ip_hdr(skb);
344 
345 		src.proto = htons(ETH_P_IP);
346 		src.ipv4.s_addr = iphdr->saddr;
347 		if (ipv4_is_multicast(iphdr->daddr))
348 			return 0;
349 #if IS_ENABLED(CONFIG_IPV6)
350 	} else if (ip_hdr(skb)->version == 6) {
351 		struct ipv6hdr *iphdr = ipv6_hdr(skb);
352 
353 		src.proto = htons(ETH_P_IPV6);
354 		src.ipv6 = iphdr->saddr;
355 		if (ipv6_addr_is_multicast(&iphdr->daddr))
356 			return 0;
357 #endif
358 	} else {
359 		return 0;
360 	}
361 
362 	if (likely(tipc_udp_is_known_peer(b, &src)))
363 		return 0;
364 
365 	return tipc_udp_rcast_add(b, &src);
366 }
367 
368 /* tipc_udp_recv - read data from bearer socket */
tipc_udp_recv(struct sock * sk,struct sk_buff * skb)369 static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb)
370 {
371 	struct udp_bearer *ub;
372 	struct tipc_bearer *b;
373 	struct tipc_msg *hdr;
374 	int err;
375 
376 	ub = rcu_dereference_sk_user_data(sk);
377 	if (!ub) {
378 		pr_err_ratelimited("Failed to get UDP bearer reference");
379 		goto out;
380 	}
381 	skb_pull(skb, sizeof(struct udphdr));
382 	hdr = buf_msg(skb);
383 
384 	b = rcu_dereference(ub->bearer);
385 	if (!b)
386 		goto out;
387 
388 	if (b && test_bit(0, &b->up)) {
389 		TIPC_SKB_CB(skb)->flags = 0;
390 		tipc_rcv(sock_net(sk), skb, b);
391 		return 0;
392 	}
393 
394 	if (unlikely(msg_user(hdr) == LINK_CONFIG)) {
395 		err = tipc_udp_rcast_disc(b, skb);
396 		if (err)
397 			goto out;
398 	}
399 
400 out:
401 	kfree_skb(skb);
402 	return 0;
403 }
404 
enable_mcast(struct udp_bearer * ub,struct udp_media_addr * remote)405 static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote)
406 {
407 	int err = 0;
408 	struct ip_mreqn mreqn;
409 	struct sock *sk = ub->ubsock->sk;
410 
411 	if (ntohs(remote->proto) == ETH_P_IP) {
412 		mreqn.imr_multiaddr = remote->ipv4;
413 		mreqn.imr_ifindex = ub->ifindex;
414 		err = ip_mc_join_group(sk, &mreqn);
415 #if IS_ENABLED(CONFIG_IPV6)
416 	} else {
417 		lock_sock(sk);
418 		err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex,
419 						   &remote->ipv6);
420 		release_sock(sk);
421 #endif
422 	}
423 	return err;
424 }
425 
__tipc_nl_add_udp_addr(struct sk_buff * skb,struct udp_media_addr * addr,int nla_t)426 static int __tipc_nl_add_udp_addr(struct sk_buff *skb,
427 				  struct udp_media_addr *addr, int nla_t)
428 {
429 	if (ntohs(addr->proto) == ETH_P_IP) {
430 		struct sockaddr_in ip4;
431 
432 		memset(&ip4, 0, sizeof(ip4));
433 		ip4.sin_family = AF_INET;
434 		ip4.sin_port = addr->port;
435 		ip4.sin_addr.s_addr = addr->ipv4.s_addr;
436 		if (nla_put(skb, nla_t, sizeof(ip4), &ip4))
437 			return -EMSGSIZE;
438 
439 #if IS_ENABLED(CONFIG_IPV6)
440 	} else if (ntohs(addr->proto) == ETH_P_IPV6) {
441 		struct sockaddr_in6 ip6;
442 
443 		memset(&ip6, 0, sizeof(ip6));
444 		ip6.sin6_family = AF_INET6;
445 		ip6.sin6_port  = addr->port;
446 		memcpy(&ip6.sin6_addr, &addr->ipv6, sizeof(struct in6_addr));
447 		if (nla_put(skb, nla_t, sizeof(ip6), &ip6))
448 			return -EMSGSIZE;
449 #endif
450 	}
451 
452 	return 0;
453 }
454 
tipc_udp_nl_dump_remoteip(struct sk_buff * skb,struct netlink_callback * cb)455 int tipc_udp_nl_dump_remoteip(struct sk_buff *skb, struct netlink_callback *cb)
456 {
457 	u32 bid = cb->args[0];
458 	u32 skip_cnt = cb->args[1];
459 	u32 portid = NETLINK_CB(cb->skb).portid;
460 	struct udp_replicast *rcast, *tmp;
461 	struct tipc_bearer *b;
462 	struct udp_bearer *ub;
463 	void *hdr;
464 	int err;
465 	int i;
466 
467 	if (!bid && !skip_cnt) {
468 		struct nlattr **attrs = genl_dumpit_info(cb)->attrs;
469 		struct net *net = sock_net(skb->sk);
470 		struct nlattr *battrs[TIPC_NLA_BEARER_MAX + 1];
471 		char *bname;
472 
473 		if (!attrs[TIPC_NLA_BEARER])
474 			return -EINVAL;
475 
476 		err = nla_parse_nested_deprecated(battrs, TIPC_NLA_BEARER_MAX,
477 						  attrs[TIPC_NLA_BEARER],
478 						  tipc_nl_bearer_policy, NULL);
479 		if (err)
480 			return err;
481 
482 		if (!battrs[TIPC_NLA_BEARER_NAME])
483 			return -EINVAL;
484 
485 		bname = nla_data(battrs[TIPC_NLA_BEARER_NAME]);
486 
487 		rtnl_lock();
488 		b = tipc_bearer_find(net, bname);
489 		if (!b) {
490 			rtnl_unlock();
491 			return -EINVAL;
492 		}
493 		bid = b->identity;
494 	} else {
495 		struct net *net = sock_net(skb->sk);
496 		struct tipc_net *tn = net_generic(net, tipc_net_id);
497 
498 		rtnl_lock();
499 		b = rtnl_dereference(tn->bearer_list[bid]);
500 		if (!b) {
501 			rtnl_unlock();
502 			return -EINVAL;
503 		}
504 	}
505 
506 	ub = rtnl_dereference(b->media_ptr);
507 	if (!ub) {
508 		rtnl_unlock();
509 		return -EINVAL;
510 	}
511 
512 	i = 0;
513 	list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
514 		if (i < skip_cnt)
515 			goto count;
516 
517 		hdr = genlmsg_put(skb, portid, cb->nlh->nlmsg_seq,
518 				  &tipc_genl_family, NLM_F_MULTI,
519 				  TIPC_NL_BEARER_GET);
520 		if (!hdr)
521 			goto done;
522 
523 		err = __tipc_nl_add_udp_addr(skb, &rcast->addr,
524 					     TIPC_NLA_UDP_REMOTE);
525 		if (err) {
526 			genlmsg_cancel(skb, hdr);
527 			goto done;
528 		}
529 		genlmsg_end(skb, hdr);
530 count:
531 		i++;
532 	}
533 done:
534 	rtnl_unlock();
535 	cb->args[0] = bid;
536 	cb->args[1] = i;
537 
538 	return skb->len;
539 }
540 
tipc_udp_nl_add_bearer_data(struct tipc_nl_msg * msg,struct tipc_bearer * b)541 int tipc_udp_nl_add_bearer_data(struct tipc_nl_msg *msg, struct tipc_bearer *b)
542 {
543 	struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
544 	struct udp_media_addr *dst;
545 	struct udp_bearer *ub;
546 	struct nlattr *nest;
547 
548 	ub = rtnl_dereference(b->media_ptr);
549 	if (!ub)
550 		return -ENODEV;
551 
552 	nest = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER_UDP_OPTS);
553 	if (!nest)
554 		goto msg_full;
555 
556 	if (__tipc_nl_add_udp_addr(msg->skb, src, TIPC_NLA_UDP_LOCAL))
557 		goto msg_full;
558 
559 	dst = (struct udp_media_addr *)&b->bcast_addr.value;
560 	if (__tipc_nl_add_udp_addr(msg->skb, dst, TIPC_NLA_UDP_REMOTE))
561 		goto msg_full;
562 
563 	if (!list_empty(&ub->rcast.list)) {
564 		if (nla_put_flag(msg->skb, TIPC_NLA_UDP_MULTI_REMOTEIP))
565 			goto msg_full;
566 	}
567 
568 	nla_nest_end(msg->skb, nest);
569 	return 0;
570 msg_full:
571 	nla_nest_cancel(msg->skb, nest);
572 	return -EMSGSIZE;
573 }
574 
575 /**
576  * tipc_parse_udp_addr - build udp media address from netlink data
577  * @nla:	netlink attribute containing sockaddr storage aligned address
578  * @addr:	tipc media address to fill with address, port and protocol type
579  * @scope_id:	IPv6 scope id pointer, not NULL indicates it's required
580  */
581 
tipc_parse_udp_addr(struct nlattr * nla,struct udp_media_addr * addr,u32 * scope_id)582 static int tipc_parse_udp_addr(struct nlattr *nla, struct udp_media_addr *addr,
583 			       u32 *scope_id)
584 {
585 	struct sockaddr_storage sa;
586 
587 	nla_memcpy(&sa, nla, sizeof(sa));
588 	if (sa.ss_family == AF_INET) {
589 		struct sockaddr_in *ip4 = (struct sockaddr_in *)&sa;
590 
591 		addr->proto = htons(ETH_P_IP);
592 		addr->port = ip4->sin_port;
593 		addr->ipv4.s_addr = ip4->sin_addr.s_addr;
594 		return 0;
595 
596 #if IS_ENABLED(CONFIG_IPV6)
597 	} else if (sa.ss_family == AF_INET6) {
598 		struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)&sa;
599 
600 		addr->proto = htons(ETH_P_IPV6);
601 		addr->port = ip6->sin6_port;
602 		memcpy(&addr->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr));
603 
604 		/* Scope ID is only interesting for local addresses */
605 		if (scope_id) {
606 			int atype;
607 
608 			atype = ipv6_addr_type(&ip6->sin6_addr);
609 			if (__ipv6_addr_needs_scope_id(atype) &&
610 			    !ip6->sin6_scope_id) {
611 				return -EINVAL;
612 			}
613 
614 			*scope_id = ip6->sin6_scope_id ? : 0;
615 		}
616 
617 		return 0;
618 #endif
619 	}
620 	return -EADDRNOTAVAIL;
621 }
622 
tipc_udp_nl_bearer_add(struct tipc_bearer * b,struct nlattr * attr)623 int tipc_udp_nl_bearer_add(struct tipc_bearer *b, struct nlattr *attr)
624 {
625 	int err;
626 	struct udp_media_addr addr = {0};
627 	struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
628 	struct udp_media_addr *dst;
629 
630 	if (nla_parse_nested_deprecated(opts, TIPC_NLA_UDP_MAX, attr, tipc_nl_udp_policy, NULL))
631 		return -EINVAL;
632 
633 	if (!opts[TIPC_NLA_UDP_REMOTE])
634 		return -EINVAL;
635 
636 	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &addr, NULL);
637 	if (err)
638 		return err;
639 
640 	dst = (struct udp_media_addr *)&b->bcast_addr.value;
641 	if (tipc_udp_is_mcast_addr(dst)) {
642 		pr_err("Can't add remote ip to TIPC UDP multicast bearer\n");
643 		return -EINVAL;
644 	}
645 
646 	if (tipc_udp_is_known_peer(b, &addr))
647 		return 0;
648 
649 	return tipc_udp_rcast_add(b, &addr);
650 }
651 
652 /**
653  * tipc_udp_enable - callback to create a new udp bearer instance
654  * @net:	network namespace
655  * @b:		pointer to generic tipc_bearer
656  * @attrs:	netlink bearer configuration
657  *
658  * validate the bearer parameters and initialize the udp bearer
659  * rtnl_lock should be held
660  */
tipc_udp_enable(struct net * net,struct tipc_bearer * b,struct nlattr * attrs[])661 static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
662 			   struct nlattr *attrs[])
663 {
664 	int err = -EINVAL;
665 	struct udp_bearer *ub;
666 	struct udp_media_addr remote = {0};
667 	struct udp_media_addr local = {0};
668 	struct udp_port_cfg udp_conf = {0};
669 	struct udp_tunnel_sock_cfg tuncfg = {NULL};
670 	struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
671 	u8 node_id[NODE_ID_LEN] = {0,};
672 	struct net_device *dev;
673 	int rmcast = 0;
674 
675 	ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
676 	if (!ub)
677 		return -ENOMEM;
678 
679 	INIT_LIST_HEAD(&ub->rcast.list);
680 
681 	if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
682 		goto err;
683 
684 	if (nla_parse_nested_deprecated(opts, TIPC_NLA_UDP_MAX, attrs[TIPC_NLA_BEARER_UDP_OPTS], tipc_nl_udp_policy, NULL))
685 		goto err;
686 
687 	if (!opts[TIPC_NLA_UDP_LOCAL] || !opts[TIPC_NLA_UDP_REMOTE]) {
688 		pr_err("Invalid UDP bearer configuration");
689 		err = -EINVAL;
690 		goto err;
691 	}
692 
693 	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_LOCAL], &local,
694 				  &ub->ifindex);
695 	if (err)
696 		goto err;
697 
698 	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], &remote, NULL);
699 	if (err)
700 		goto err;
701 
702 	if (remote.proto != local.proto) {
703 		err = -EINVAL;
704 		goto err;
705 	}
706 
707 	/* Checking remote ip address */
708 	rmcast = tipc_udp_is_mcast_addr(&remote);
709 
710 	/* Autoconfigure own node identity if needed */
711 	if (!tipc_own_id(net)) {
712 		memcpy(node_id, local.ipv6.in6_u.u6_addr8, 16);
713 		tipc_net_init(net, node_id, 0);
714 	}
715 	if (!tipc_own_id(net)) {
716 		pr_warn("Failed to set node id, please configure manually\n");
717 		err = -EINVAL;
718 		goto err;
719 	}
720 
721 	b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP;
722 	b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
723 	rcu_assign_pointer(b->media_ptr, ub);
724 	rcu_assign_pointer(ub->bearer, b);
725 	tipc_udp_media_addr_set(&b->addr, &local);
726 	if (local.proto == htons(ETH_P_IP)) {
727 		dev = __ip_dev_find(net, local.ipv4.s_addr, false);
728 		if (!dev) {
729 			err = -ENODEV;
730 			goto err;
731 		}
732 		udp_conf.family = AF_INET;
733 
734 		/* Switch to use ANY to receive packets from group */
735 		if (rmcast)
736 			udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
737 		else
738 			udp_conf.local_ip.s_addr = local.ipv4.s_addr;
739 		udp_conf.use_udp_checksums = false;
740 		ub->ifindex = dev->ifindex;
741 		b->encap_hlen = sizeof(struct iphdr) + sizeof(struct udphdr);
742 		if (tipc_mtu_bad(dev, b->encap_hlen)) {
743 			err = -EINVAL;
744 			goto err;
745 		}
746 		b->mtu = b->media->mtu;
747 #if IS_ENABLED(CONFIG_IPV6)
748 	} else if (local.proto == htons(ETH_P_IPV6)) {
749 		dev = ub->ifindex ? __dev_get_by_index(net, ub->ifindex) : NULL;
750 		dev = ipv6_dev_find(net, &local.ipv6, dev);
751 		if (!dev) {
752 			err = -ENODEV;
753 			goto err;
754 		}
755 		udp_conf.family = AF_INET6;
756 		udp_conf.use_udp6_tx_checksums = true;
757 		udp_conf.use_udp6_rx_checksums = true;
758 		if (rmcast)
759 			udp_conf.local_ip6 = in6addr_any;
760 		else
761 			udp_conf.local_ip6 = local.ipv6;
762 		ub->ifindex = dev->ifindex;
763 		b->encap_hlen = sizeof(struct ipv6hdr) + sizeof(struct udphdr);
764 		b->mtu = 1280;
765 #endif
766 	} else {
767 		err = -EAFNOSUPPORT;
768 		goto err;
769 	}
770 	udp_conf.local_udp_port = local.port;
771 	err = udp_sock_create(net, &udp_conf, &ub->ubsock);
772 	if (err)
773 		goto err;
774 	tuncfg.sk_user_data = ub;
775 	tuncfg.encap_type = 1;
776 	tuncfg.encap_rcv = tipc_udp_recv;
777 	tuncfg.encap_destroy = NULL;
778 	setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg);
779 
780 	err = dst_cache_init(&ub->rcast.dst_cache, GFP_ATOMIC);
781 	if (err)
782 		goto free;
783 
784 	/*
785 	 * The bcast media address port is used for all peers and the ip
786 	 * is used if it's a multicast address.
787 	 */
788 	memcpy(&b->bcast_addr.value, &remote, sizeof(remote));
789 	if (rmcast)
790 		err = enable_mcast(ub, &remote);
791 	else
792 		err = tipc_udp_rcast_add(b, &remote);
793 	if (err)
794 		goto free;
795 
796 	return 0;
797 
798 free:
799 	dst_cache_destroy(&ub->rcast.dst_cache);
800 	udp_tunnel_sock_release(ub->ubsock);
801 err:
802 	kfree(ub);
803 	return err;
804 }
805 
806 /* cleanup_bearer - break the socket/bearer association */
cleanup_bearer(struct work_struct * work)807 static void cleanup_bearer(struct work_struct *work)
808 {
809 	struct udp_bearer *ub = container_of(work, struct udp_bearer, work);
810 	struct udp_replicast *rcast, *tmp;
811 
812 	list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) {
813 		dst_cache_destroy(&rcast->dst_cache);
814 		list_del_rcu(&rcast->list);
815 		kfree_rcu(rcast, rcu);
816 	}
817 
818 	atomic_dec(&tipc_net(sock_net(ub->ubsock->sk))->wq_count);
819 	dst_cache_destroy(&ub->rcast.dst_cache);
820 	udp_tunnel_sock_release(ub->ubsock);
821 	synchronize_net();
822 	kfree(ub);
823 }
824 
825 /* tipc_udp_disable - detach bearer from socket */
tipc_udp_disable(struct tipc_bearer * b)826 static void tipc_udp_disable(struct tipc_bearer *b)
827 {
828 	struct udp_bearer *ub;
829 
830 	ub = rtnl_dereference(b->media_ptr);
831 	if (!ub) {
832 		pr_err("UDP bearer instance not found\n");
833 		return;
834 	}
835 	sock_set_flag(ub->ubsock->sk, SOCK_DEAD);
836 	RCU_INIT_POINTER(ub->bearer, NULL);
837 
838 	/* sock_release need to be done outside of rtnl lock */
839 	atomic_inc(&tipc_net(sock_net(ub->ubsock->sk))->wq_count);
840 	INIT_WORK(&ub->work, cleanup_bearer);
841 	schedule_work(&ub->work);
842 }
843 
844 struct tipc_media udp_media_info = {
845 	.send_msg	= tipc_udp_send_msg,
846 	.enable_media	= tipc_udp_enable,
847 	.disable_media	= tipc_udp_disable,
848 	.addr2str	= tipc_udp_addr2str,
849 	.addr2msg	= tipc_udp_addr2msg,
850 	.msg2addr	= tipc_udp_msg2addr,
851 	.priority	= TIPC_DEF_LINK_PRI,
852 	.tolerance	= TIPC_DEF_LINK_TOL,
853 	.min_win	= TIPC_DEF_LINK_WIN,
854 	.max_win	= TIPC_DEF_LINK_WIN,
855 	.mtu		= TIPC_DEF_LINK_UDP_MTU,
856 	.type_id	= TIPC_MEDIA_TYPE_UDP,
857 	.hwaddr_len	= 0,
858 	.name		= "udp"
859 };
860