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