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 "bearer.h"
51
52 /* IANA assigned UDP port */
53 #define UDP_PORT_DEFAULT 6118
54
55 #define UDP_MIN_HEADROOM 48
56
57 static const struct nla_policy tipc_nl_udp_policy[TIPC_NLA_UDP_MAX + 1] = {
58 [TIPC_NLA_UDP_UNSPEC] = {.type = NLA_UNSPEC},
59 [TIPC_NLA_UDP_LOCAL] = {.type = NLA_BINARY,
60 .len = sizeof(struct sockaddr_storage)},
61 [TIPC_NLA_UDP_REMOTE] = {.type = NLA_BINARY,
62 .len = sizeof(struct sockaddr_storage)},
63 };
64
65 /**
66 * struct udp_media_addr - IP/UDP addressing information
67 *
68 * This is the bearer level originating address used in neighbor discovery
69 * messages, and all fields should be in network byte order
70 */
71 struct udp_media_addr {
72 __be16 proto;
73 __be16 udp_port;
74 union {
75 struct in_addr ipv4;
76 struct in6_addr ipv6;
77 };
78 };
79
80 /**
81 * struct udp_bearer - ip/udp bearer data structure
82 * @bearer: associated generic tipc bearer
83 * @ubsock: bearer associated socket
84 * @ifindex: local address scope
85 * @work: used to schedule deferred work on a bearer
86 */
87 struct udp_bearer {
88 struct tipc_bearer __rcu *bearer;
89 struct socket *ubsock;
90 u32 ifindex;
91 struct work_struct work;
92 };
93
94 /* 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)95 static void tipc_udp_media_addr_set(struct tipc_media_addr *addr,
96 struct udp_media_addr *ua)
97 {
98 memset(addr, 0, sizeof(struct tipc_media_addr));
99 addr->media_id = TIPC_MEDIA_TYPE_UDP;
100 memcpy(addr->value, ua, sizeof(struct udp_media_addr));
101 if (ntohs(ua->proto) == ETH_P_IP) {
102 if (ipv4_is_multicast(ua->ipv4.s_addr))
103 addr->broadcast = 1;
104 } else if (ntohs(ua->proto) == ETH_P_IPV6) {
105 if (ipv6_addr_type(&ua->ipv6) & IPV6_ADDR_MULTICAST)
106 addr->broadcast = 1;
107 } else {
108 pr_err("Invalid UDP media address\n");
109 }
110 }
111
112 /* tipc_udp_addr2str - convert ip/udp address to string */
tipc_udp_addr2str(struct tipc_media_addr * a,char * buf,int size)113 static int tipc_udp_addr2str(struct tipc_media_addr *a, char *buf, int size)
114 {
115 struct udp_media_addr *ua = (struct udp_media_addr *)&a->value;
116
117 if (ntohs(ua->proto) == ETH_P_IP)
118 snprintf(buf, size, "%pI4:%u", &ua->ipv4, ntohs(ua->udp_port));
119 else if (ntohs(ua->proto) == ETH_P_IPV6)
120 snprintf(buf, size, "%pI6:%u", &ua->ipv6, ntohs(ua->udp_port));
121 else
122 pr_err("Invalid UDP media address\n");
123 return 0;
124 }
125
126 /* 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)127 static int tipc_udp_msg2addr(struct tipc_bearer *b, struct tipc_media_addr *a,
128 char *msg)
129 {
130 struct udp_media_addr *ua;
131
132 ua = (struct udp_media_addr *) (msg + TIPC_MEDIA_ADDR_OFFSET);
133 if (msg[TIPC_MEDIA_TYPE_OFFSET] != TIPC_MEDIA_TYPE_UDP)
134 return -EINVAL;
135 tipc_udp_media_addr_set(a, ua);
136 return 0;
137 }
138
139 /* tipc_udp_addr2msg - write an ip/udp address to a TIPC ndisc message */
tipc_udp_addr2msg(char * msg,struct tipc_media_addr * a)140 static int tipc_udp_addr2msg(char *msg, struct tipc_media_addr *a)
141 {
142 memset(msg, 0, TIPC_MEDIA_INFO_SIZE);
143 msg[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_UDP;
144 memcpy(msg + TIPC_MEDIA_ADDR_OFFSET, a->value,
145 sizeof(struct udp_media_addr));
146 return 0;
147 }
148
149 /* tipc_send_msg - enqueue a send request */
tipc_udp_send_msg(struct net * net,struct sk_buff * skb,struct tipc_bearer * b,struct tipc_media_addr * dest)150 static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
151 struct tipc_bearer *b,
152 struct tipc_media_addr *dest)
153 {
154 int ttl, err = 0;
155 struct udp_bearer *ub;
156 struct udp_media_addr *dst = (struct udp_media_addr *)&dest->value;
157 struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
158 struct rtable *rt;
159
160 if (skb_headroom(skb) < UDP_MIN_HEADROOM) {
161 err = pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC);
162 if (err)
163 goto tx_error;
164 }
165
166 skb_set_inner_protocol(skb, htons(ETH_P_TIPC));
167 ub = rcu_dereference_rtnl(b->media_ptr);
168 if (!ub) {
169 err = -ENODEV;
170 goto tx_error;
171 }
172 if (dst->proto == htons(ETH_P_IP)) {
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 ttl = ip4_dst_hoplimit(&rt->dst);
185 err = udp_tunnel_xmit_skb(rt, ub->ubsock->sk, skb,
186 src->ipv4.s_addr,
187 dst->ipv4.s_addr, 0, ttl, 0,
188 src->udp_port, dst->udp_port,
189 false, true);
190 if (err < 0) {
191 ip_rt_put(rt);
192 goto tx_error;
193 }
194 #if IS_ENABLED(CONFIG_IPV6)
195 } else {
196 struct dst_entry *ndst;
197 struct flowi6 fl6 = {
198 .flowi6_oif = ub->ifindex,
199 .daddr = dst->ipv6,
200 .saddr = src->ipv6,
201 .flowi6_proto = IPPROTO_UDP
202 };
203 ndst = ipv6_stub->ipv6_dst_lookup_flow(net,
204 ub->ubsock->sk,
205 &fl6, NULL);
206 if (IS_ERR(ndst)) {
207 err = PTR_ERR(ndst);
208 goto tx_error;
209 }
210 ttl = ip6_dst_hoplimit(ndst);
211 err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb,
212 ndst->dev, &src->ipv6,
213 &dst->ipv6, 0, ttl, src->udp_port,
214 dst->udp_port, false);
215 #endif
216 }
217 return err;
218
219 tx_error:
220 kfree_skb(skb);
221 return err;
222 }
223
224 /* tipc_udp_recv - read data from bearer socket */
tipc_udp_recv(struct sock * sk,struct sk_buff * skb)225 static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb)
226 {
227 struct udp_bearer *ub;
228 struct tipc_bearer *b;
229
230 ub = rcu_dereference_sk_user_data(sk);
231 if (!ub) {
232 pr_err_ratelimited("Failed to get UDP bearer reference");
233 kfree_skb(skb);
234 return 0;
235 }
236
237 skb_pull(skb, sizeof(struct udphdr));
238 rcu_read_lock();
239 b = rcu_dereference_rtnl(ub->bearer);
240
241 if (b) {
242 tipc_rcv(sock_net(sk), skb, b);
243 rcu_read_unlock();
244 return 0;
245 }
246 rcu_read_unlock();
247 kfree_skb(skb);
248 return 0;
249 }
250
enable_mcast(struct udp_bearer * ub,struct udp_media_addr * remote)251 static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote)
252 {
253 int err = 0;
254 struct ip_mreqn mreqn;
255 struct sock *sk = ub->ubsock->sk;
256
257 if (ntohs(remote->proto) == ETH_P_IP) {
258 if (!ipv4_is_multicast(remote->ipv4.s_addr))
259 return 0;
260 mreqn.imr_multiaddr = remote->ipv4;
261 mreqn.imr_ifindex = ub->ifindex;
262 err = ip_mc_join_group(sk, &mreqn);
263 #if IS_ENABLED(CONFIG_IPV6)
264 } else {
265 if (!ipv6_addr_is_multicast(&remote->ipv6))
266 return 0;
267 err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex,
268 &remote->ipv6);
269 #endif
270 }
271 return err;
272 }
273
274 /**
275 * parse_options - build local/remote addresses from configuration
276 * @attrs: netlink config data
277 * @ub: UDP bearer instance
278 * @local: local bearer IP address/port
279 * @remote: peer or multicast IP/port
280 */
parse_options(struct nlattr * attrs[],struct udp_bearer * ub,struct udp_media_addr * local,struct udp_media_addr * remote)281 static int parse_options(struct nlattr *attrs[], struct udp_bearer *ub,
282 struct udp_media_addr *local,
283 struct udp_media_addr *remote)
284 {
285 struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
286 struct sockaddr_storage *sa_local, *sa_remote;
287
288 if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
289 goto err;
290 if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX,
291 attrs[TIPC_NLA_BEARER_UDP_OPTS],
292 tipc_nl_udp_policy))
293 goto err;
294 if (opts[TIPC_NLA_UDP_LOCAL] && opts[TIPC_NLA_UDP_REMOTE]) {
295 sa_local = nla_data(opts[TIPC_NLA_UDP_LOCAL]);
296 sa_remote = nla_data(opts[TIPC_NLA_UDP_REMOTE]);
297 } else {
298 err:
299 pr_err("Invalid UDP bearer configuration");
300 return -EINVAL;
301 }
302 if ((sa_local->ss_family & sa_remote->ss_family) == AF_INET) {
303 struct sockaddr_in *ip4;
304
305 ip4 = (struct sockaddr_in *)sa_local;
306 local->proto = htons(ETH_P_IP);
307 local->udp_port = ip4->sin_port;
308 local->ipv4.s_addr = ip4->sin_addr.s_addr;
309
310 ip4 = (struct sockaddr_in *)sa_remote;
311 remote->proto = htons(ETH_P_IP);
312 remote->udp_port = ip4->sin_port;
313 remote->ipv4.s_addr = ip4->sin_addr.s_addr;
314 return 0;
315
316 #if IS_ENABLED(CONFIG_IPV6)
317 } else if ((sa_local->ss_family & sa_remote->ss_family) == AF_INET6) {
318 struct sockaddr_in6 *ip6;
319
320 ip6 = (struct sockaddr_in6 *)sa_local;
321 local->proto = htons(ETH_P_IPV6);
322 local->udp_port = ip6->sin6_port;
323 local->ipv6 = ip6->sin6_addr;
324 ub->ifindex = ip6->sin6_scope_id;
325
326 ip6 = (struct sockaddr_in6 *)sa_remote;
327 remote->proto = htons(ETH_P_IPV6);
328 remote->udp_port = ip6->sin6_port;
329 remote->ipv6 = ip6->sin6_addr;
330 return 0;
331 #endif
332 }
333 return -EADDRNOTAVAIL;
334 }
335
336 /**
337 * tipc_udp_enable - callback to create a new udp bearer instance
338 * @net: network namespace
339 * @b: pointer to generic tipc_bearer
340 * @attrs: netlink bearer configuration
341 *
342 * validate the bearer parameters and initialize the udp bearer
343 * rtnl_lock should be held
344 */
tipc_udp_enable(struct net * net,struct tipc_bearer * b,struct nlattr * attrs[])345 static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
346 struct nlattr *attrs[])
347 {
348 int err = -EINVAL;
349 struct udp_bearer *ub;
350 struct udp_media_addr *remote;
351 struct udp_media_addr local = {0};
352 struct udp_port_cfg udp_conf = {0};
353 struct udp_tunnel_sock_cfg tuncfg = {NULL};
354
355 ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
356 if (!ub)
357 return -ENOMEM;
358
359 remote = (struct udp_media_addr *)&b->bcast_addr.value;
360 memset(remote, 0, sizeof(struct udp_media_addr));
361 err = parse_options(attrs, ub, &local, remote);
362 if (err)
363 goto err;
364
365 b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP;
366 b->bcast_addr.broadcast = 1;
367 rcu_assign_pointer(b->media_ptr, ub);
368 rcu_assign_pointer(ub->bearer, b);
369 tipc_udp_media_addr_set(&b->addr, &local);
370 if (local.proto == htons(ETH_P_IP)) {
371 struct net_device *dev;
372
373 dev = __ip_dev_find(net, local.ipv4.s_addr, false);
374 if (!dev) {
375 err = -ENODEV;
376 goto err;
377 }
378 udp_conf.family = AF_INET;
379 udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
380 udp_conf.use_udp_checksums = false;
381 ub->ifindex = dev->ifindex;
382 if (tipc_mtu_bad(dev, sizeof(struct iphdr) +
383 sizeof(struct udphdr))) {
384 err = -EINVAL;
385 goto err;
386 }
387 b->mtu = dev->mtu - sizeof(struct iphdr)
388 - sizeof(struct udphdr);
389 #if IS_ENABLED(CONFIG_IPV6)
390 } else if (local.proto == htons(ETH_P_IPV6)) {
391 udp_conf.family = AF_INET6;
392 udp_conf.use_udp6_tx_checksums = true;
393 udp_conf.use_udp6_rx_checksums = true;
394 udp_conf.local_ip6 = in6addr_any;
395 b->mtu = 1280;
396 #endif
397 } else {
398 err = -EAFNOSUPPORT;
399 goto err;
400 }
401 udp_conf.local_udp_port = local.udp_port;
402 err = udp_sock_create(net, &udp_conf, &ub->ubsock);
403 if (err)
404 goto err;
405 tuncfg.sk_user_data = ub;
406 tuncfg.encap_type = 1;
407 tuncfg.encap_rcv = tipc_udp_recv;
408 tuncfg.encap_destroy = NULL;
409 setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg);
410
411 err = enable_mcast(ub, remote);
412 if (err)
413 goto err;
414 return 0;
415 err:
416 if (ub->ubsock)
417 udp_tunnel_sock_release(ub->ubsock);
418 kfree(ub);
419 return err;
420 }
421
422 /* cleanup_bearer - break the socket/bearer association */
cleanup_bearer(struct work_struct * work)423 static void cleanup_bearer(struct work_struct *work)
424 {
425 struct udp_bearer *ub = container_of(work, struct udp_bearer, work);
426
427 if (ub->ubsock)
428 udp_tunnel_sock_release(ub->ubsock);
429 synchronize_net();
430 kfree(ub);
431 }
432
433 /* tipc_udp_disable - detach bearer from socket */
tipc_udp_disable(struct tipc_bearer * b)434 static void tipc_udp_disable(struct tipc_bearer *b)
435 {
436 struct udp_bearer *ub;
437
438 ub = rcu_dereference_rtnl(b->media_ptr);
439 if (!ub) {
440 pr_err("UDP bearer instance not found\n");
441 return;
442 }
443 if (ub->ubsock)
444 sock_set_flag(ub->ubsock->sk, SOCK_DEAD);
445 RCU_INIT_POINTER(ub->bearer, NULL);
446
447 /* sock_release need to be done outside of rtnl lock */
448 INIT_WORK(&ub->work, cleanup_bearer);
449 schedule_work(&ub->work);
450 }
451
452 struct tipc_media udp_media_info = {
453 .send_msg = tipc_udp_send_msg,
454 .enable_media = tipc_udp_enable,
455 .disable_media = tipc_udp_disable,
456 .addr2str = tipc_udp_addr2str,
457 .addr2msg = tipc_udp_addr2msg,
458 .msg2addr = tipc_udp_msg2addr,
459 .priority = TIPC_DEF_LINK_PRI,
460 .tolerance = TIPC_DEF_LINK_TOL,
461 .window = TIPC_DEF_LINK_WIN,
462 .type_id = TIPC_MEDIA_TYPE_UDP,
463 .hwaddr_len = 0,
464 .name = "udp"
465 };
466