xref: /trueos/sys/ofed/drivers/infiniband/core/addr.c (revision 1428bc6a8724cdc2bc2edf4c9ddd41eac844c81c)
1 /*
2  * Copyright (c) 2005 Voltaire Inc.  All rights reserved.
3  * Copyright (c) 2002-2005, Network Appliance, Inc. All rights reserved.
4  * Copyright (c) 1999-2005, Mellanox Technologies, Inc. All rights reserved.
5  * Copyright (c) 2005 Intel Corporation.  All rights reserved.
6  *
7  * This software is available to you under a choice of one of two
8  * licenses.  You may choose to be licensed under the terms of the GNU
9  * General Public License (GPL) Version 2, available from the file
10  * COPYING in the main directory of this source tree, or the
11  * OpenIB.org BSD license below:
12  *
13  *     Redistribution and use in source and binary forms, with or
14  *     without modification, are permitted provided that the following
15  *     conditions are met:
16  *
17  *      - Redistributions of source code must retain the above
18  *        copyright notice, this list of conditions and the following
19  *        disclaimer.
20  *
21  *      - Redistributions in binary form must reproduce the above
22  *        copyright notice, this list of conditions and the following
23  *        disclaimer in the documentation and/or other materials
24  *        provided with the distribution.
25  *
26  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
27  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
28  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
29  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
30  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
31  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
32  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
33  * SOFTWARE.
34  */
35 
36 #include <linux/mutex.h>
37 #include <linux/inetdevice.h>
38 #include <linux/slab.h>
39 #include <linux/workqueue.h>
40 #include <linux/module.h>
41 #include <linux/notifier.h>
42 #include <net/route.h>
43 #include <net/netevent.h>
44 #include <rdma/ib_addr.h>
45 #include <netinet/if_ether.h>
46 
47 
48 MODULE_AUTHOR("Sean Hefty");
49 MODULE_DESCRIPTION("IB Address Translation");
50 MODULE_LICENSE("Dual BSD/GPL");
51 
52 struct addr_req {
53 	struct list_head list;
54 	struct sockaddr_storage src_addr;
55 	struct sockaddr_storage dst_addr;
56 	struct rdma_dev_addr *addr;
57 	struct rdma_addr_client *client;
58 	void *context;
59 	void (*callback)(int status, struct sockaddr *src_addr,
60 			 struct rdma_dev_addr *addr, void *context);
61 	unsigned long timeout;
62 	int status;
63 };
64 
65 static void process_req(struct work_struct *work);
66 
67 static DEFINE_MUTEX(lock);
68 static LIST_HEAD(req_list);
69 static struct delayed_work work;
70 static struct workqueue_struct *addr_wq;
71 
rdma_addr_register_client(struct rdma_addr_client * client)72 void rdma_addr_register_client(struct rdma_addr_client *client)
73 {
74 	atomic_set(&client->refcount, 1);
75 	init_completion(&client->comp);
76 }
77 EXPORT_SYMBOL(rdma_addr_register_client);
78 
put_client(struct rdma_addr_client * client)79 static inline void put_client(struct rdma_addr_client *client)
80 {
81 	if (atomic_dec_and_test(&client->refcount))
82 		complete(&client->comp);
83 }
84 
rdma_addr_unregister_client(struct rdma_addr_client * client)85 void rdma_addr_unregister_client(struct rdma_addr_client *client)
86 {
87 	put_client(client);
88 	wait_for_completion(&client->comp);
89 }
90 EXPORT_SYMBOL(rdma_addr_unregister_client);
91 
92 #ifdef __linux__
rdma_copy_addr(struct rdma_dev_addr * dev_addr,struct net_device * dev,const unsigned char * dst_dev_addr)93 int rdma_copy_addr(struct rdma_dev_addr *dev_addr, struct net_device *dev,
94 		     const unsigned char *dst_dev_addr)
95 {
96 	dev_addr->dev_type = dev->type;
97 	memcpy(dev_addr->src_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
98 	memcpy(dev_addr->broadcast, dev->broadcast, MAX_ADDR_LEN);
99 	if (dst_dev_addr)
100 		memcpy(dev_addr->dst_dev_addr, dst_dev_addr, MAX_ADDR_LEN);
101 	dev_addr->bound_dev_if = dev->ifindex;
102 	return 0;
103 }
104 #else
rdma_copy_addr(struct rdma_dev_addr * dev_addr,struct ifnet * dev,const unsigned char * dst_dev_addr)105 int rdma_copy_addr(struct rdma_dev_addr *dev_addr, struct ifnet *dev,
106 		     const unsigned char *dst_dev_addr)
107 {
108 	if (dev->if_type == IFT_INFINIBAND)
109 		dev_addr->dev_type = ARPHRD_INFINIBAND;
110 	else if (dev->if_type == IFT_ETHER)
111 		dev_addr->dev_type = ARPHRD_ETHER;
112 	else
113 		dev_addr->dev_type = 0;
114 	memcpy(dev_addr->src_dev_addr, IF_LLADDR(dev), dev->if_addrlen);
115 	memcpy(dev_addr->broadcast, __DECONST(char *, dev->if_broadcastaddr),
116 	    dev->if_addrlen);
117 	if (dst_dev_addr)
118 		memcpy(dev_addr->dst_dev_addr, dst_dev_addr, dev->if_addrlen);
119 	dev_addr->bound_dev_if = dev->if_index;
120 	return 0;
121 }
122 #endif
123 EXPORT_SYMBOL(rdma_copy_addr);
124 
rdma_translate_ip(struct sockaddr * addr,struct rdma_dev_addr * dev_addr)125 int rdma_translate_ip(struct sockaddr *addr, struct rdma_dev_addr *dev_addr)
126 {
127 	struct net_device *dev;
128 	int ret = -EADDRNOTAVAIL;
129 
130 	if (dev_addr->bound_dev_if) {
131 		dev = dev_get_by_index(&init_net, dev_addr->bound_dev_if);
132 		if (!dev)
133 			return -ENODEV;
134 		ret = rdma_copy_addr(dev_addr, dev, NULL);
135 		dev_put(dev);
136 		return ret;
137 	}
138 
139 	switch (addr->sa_family) {
140 #ifdef INET
141 	case AF_INET:
142 		dev = ip_dev_find(NULL,
143 			((struct sockaddr_in *) addr)->sin_addr.s_addr);
144 
145 		if (!dev)
146 			return ret;
147 
148 		ret = rdma_copy_addr(dev_addr, dev, NULL);
149 		dev_put(dev);
150 		break;
151 #endif
152 
153 #if defined(INET6)
154 	case AF_INET6:
155 #ifdef __linux__
156 		read_lock(&dev_base_lock);
157 		for_each_netdev(&init_net, dev) {
158 			if (ipv6_chk_addr(&init_net,
159 					  &((struct sockaddr_in6 *) addr)->sin6_addr,
160 					  dev, 1)) {
161 				ret = rdma_copy_addr(dev_addr, dev, NULL);
162 				break;
163 			}
164 		}
165 		read_unlock(&dev_base_lock);
166 #else
167 		{
168 			struct sockaddr_in6 *sin6;
169 			struct ifaddr *ifa;
170 			in_port_t port;
171 
172 			sin6 = (struct sockaddr_in6 *)addr;
173 			port = sin6->sin6_port;
174 			sin6->sin6_port = 0;
175 			ifa = ifa_ifwithaddr(addr);
176 			sin6->sin6_port = port;
177 			if (ifa == NULL) {
178 				ret = -ENODEV;
179 				break;
180 			}
181 			ret = rdma_copy_addr(dev_addr, ifa->ifa_ifp, NULL);
182 			ifa_free(ifa);
183 			break;
184 		}
185 #endif
186 		break;
187 #endif
188 	}
189 	return ret;
190 }
191 EXPORT_SYMBOL(rdma_translate_ip);
192 
set_timeout(unsigned long time)193 static void set_timeout(unsigned long time)
194 {
195 	unsigned long delay;
196 
197 	delay = time - jiffies;
198 	if ((long)delay <= 0)
199 		delay = 1;
200 
201 	mod_delayed_work(addr_wq, &work, delay);
202 }
203 
queue_req(struct addr_req * req)204 static void queue_req(struct addr_req *req)
205 {
206 	struct addr_req *temp_req;
207 
208 	mutex_lock(&lock);
209 	list_for_each_entry_reverse(temp_req, &req_list, list) {
210 		if (time_after_eq(req->timeout, temp_req->timeout))
211 			break;
212 	}
213 
214 	list_add(&req->list, &temp_req->list);
215 
216 	if (req_list.next == &req->list)
217 		set_timeout(req->timeout);
218 	mutex_unlock(&lock);
219 }
220 
221 #ifdef __linux__
addr4_resolve(struct sockaddr_in * src_in,struct sockaddr_in * dst_in,struct rdma_dev_addr * addr)222 static int addr4_resolve(struct sockaddr_in *src_in,
223 			 struct sockaddr_in *dst_in,
224 			 struct rdma_dev_addr *addr)
225 {
226 	__be32 src_ip = src_in->sin_addr.s_addr;
227 	__be32 dst_ip = dst_in->sin_addr.s_addr;
228 	struct flowi fl;
229 	struct rtable *rt;
230 	struct neighbour *neigh;
231 	int ret;
232 
233 	memset(&fl, 0, sizeof fl);
234 	fl.nl_u.ip4_u.daddr = dst_ip;
235 	fl.nl_u.ip4_u.saddr = src_ip;
236 	fl.oif = addr->bound_dev_if;
237 
238 	ret = ip_route_output_key(&init_net, &rt, &fl);
239 	if (ret)
240 		goto out;
241 
242 	src_in->sin_family = AF_INET;
243 	src_in->sin_addr.s_addr = rt->rt_src;
244 
245 	if (rt->idev->dev->flags & IFF_LOOPBACK) {
246 		ret = rdma_translate_ip((struct sockaddr *) dst_in, addr);
247 		if (!ret)
248 			memcpy(addr->dst_dev_addr, addr->src_dev_addr, MAX_ADDR_LEN);
249 		goto put;
250 	}
251 
252 	/* If the device does ARP internally, return 'done' */
253 	if (rt->idev->dev->flags & IFF_NOARP) {
254 		rdma_copy_addr(addr, rt->idev->dev, NULL);
255 		goto put;
256 	}
257 
258 	neigh = neigh_lookup(&arp_tbl, &rt->rt_gateway, rt->idev->dev);
259 	if (!neigh || !(neigh->nud_state & NUD_VALID)) {
260 		neigh_event_send(rt->u.dst.neighbour, NULL);
261 		ret = -ENODATA;
262 		if (neigh)
263 			goto release;
264 		goto put;
265 	}
266 
267 	ret = rdma_copy_addr(addr, neigh->dev, neigh->ha);
268 release:
269 	neigh_release(neigh);
270 put:
271 	ip_rt_put(rt);
272 out:
273 	return ret;
274 }
275 
276 #if defined(INET6)
addr6_resolve(struct sockaddr_in6 * src_in,struct sockaddr_in6 * dst_in,struct rdma_dev_addr * addr)277 static int addr6_resolve(struct sockaddr_in6 *src_in,
278 			 struct sockaddr_in6 *dst_in,
279 			 struct rdma_dev_addr *addr)
280 {
281 	struct flowi fl;
282 	struct neighbour *neigh;
283 	struct dst_entry *dst;
284 	int ret;
285 
286 	memset(&fl, 0, sizeof fl);
287 	ipv6_addr_copy(&fl.fl6_dst, &dst_in->sin6_addr);
288 	ipv6_addr_copy(&fl.fl6_src, &src_in->sin6_addr);
289 	fl.oif = addr->bound_dev_if;
290 
291 	dst = ip6_route_output(&init_net, NULL, &fl);
292 	if ((ret = dst->error))
293 		goto put;
294 
295 	if (ipv6_addr_any(&fl.fl6_src)) {
296 		ret = ipv6_dev_get_saddr(&init_net, ip6_dst_idev(dst)->dev,
297 					 &fl.fl6_dst, 0, &fl.fl6_src);
298 		if (ret)
299 			goto put;
300 
301 		src_in->sin6_family = AF_INET6;
302 		ipv6_addr_copy(&src_in->sin6_addr, &fl.fl6_src);
303 	}
304 
305 	if (dst->dev->flags & IFF_LOOPBACK) {
306 		ret = rdma_translate_ip((struct sockaddr *) dst_in, addr);
307 		if (!ret)
308 			memcpy(addr->dst_dev_addr, addr->src_dev_addr, MAX_ADDR_LEN);
309 		goto put;
310 	}
311 
312 	/* If the device does ARP internally, return 'done' */
313 	if (dst->dev->flags & IFF_NOARP) {
314 		ret = rdma_copy_addr(addr, dst->dev, NULL);
315 		goto put;
316 	}
317 
318 	neigh = dst->neighbour;
319 	if (!neigh || !(neigh->nud_state & NUD_VALID)) {
320 		neigh_event_send(dst->neighbour, NULL);
321 		ret = -ENODATA;
322 		goto put;
323 	}
324 
325 	ret = rdma_copy_addr(addr, dst->dev, neigh->ha);
326 put:
327 	dst_release(dst);
328 	return ret;
329 }
330 #else
addr6_resolve(struct sockaddr_in6 * src_in,struct sockaddr_in6 * dst_in,struct rdma_dev_addr * addr)331 static int addr6_resolve(struct sockaddr_in6 *src_in,
332 			 struct sockaddr_in6 *dst_in,
333 			 struct rdma_dev_addr *addr)
334 {
335 	return -EADDRNOTAVAIL;
336 }
337 #endif
338 
339 #else
340 #include <netinet/if_ether.h>
341 
addr_resolve(struct sockaddr * src_in,struct sockaddr * dst_in,struct rdma_dev_addr * addr)342 static int addr_resolve(struct sockaddr *src_in,
343 			struct sockaddr *dst_in,
344 			struct rdma_dev_addr *addr)
345 {
346 	struct sockaddr_in *sin;
347 	struct sockaddr_in6 *sin6;
348 	struct ifaddr *ifa;
349 	struct ifnet *ifp;
350 #if defined(INET) || defined(INET6)
351 	struct llentry *lle;
352 #endif
353 	struct rtentry *rte;
354 	in_port_t port;
355 	u_char edst[MAX_ADDR_LEN];
356 	int multi;
357 	int bcast;
358 	int error = 0;
359 
360 	/*
361 	 * Determine whether the address is unicast, multicast, or broadcast
362 	 * and whether the source interface is valid.
363 	 */
364 	multi = 0;
365 	bcast = 0;
366 	sin = NULL;
367 	sin6 = NULL;
368 	ifp = NULL;
369 	rte = NULL;
370 	switch (dst_in->sa_family) {
371 #ifdef INET
372 	case AF_INET:
373 		sin = (struct sockaddr_in *)dst_in;
374 		if (sin->sin_addr.s_addr == INADDR_BROADCAST)
375 			bcast = 1;
376 		if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr)))
377 			multi = 1;
378 		sin = (struct sockaddr_in *)src_in;
379 		if (sin->sin_addr.s_addr != INADDR_ANY) {
380 			/*
381 			 * Address comparison fails if the port is set
382 			 * cache it here to be restored later.
383 			 */
384 			port = sin->sin_port;
385 			sin->sin_port = 0;
386 			memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
387 		} else
388 			src_in = NULL;
389 		break;
390 #endif
391 #ifdef INET6
392 	case AF_INET6:
393 		sin6 = (struct sockaddr_in6 *)dst_in;
394 		if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
395 			multi = 1;
396 		sin6 = (struct sockaddr_in6 *)src_in;
397 		if (!IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
398 			port = sin6->sin6_port;
399 			sin6->sin6_port = 0;
400 		} else
401 			src_in = NULL;
402 		break;
403 #endif
404 	default:
405 		return -EINVAL;
406 	}
407 	/*
408 	 * If we have a source address to use look it up first and verify
409 	 * that it is a local interface.
410 	 */
411 	if (src_in) {
412 		ifa = ifa_ifwithaddr(src_in);
413 		if (sin)
414 			sin->sin_port = port;
415 		if (sin6)
416 			sin6->sin6_port = port;
417 		if (ifa == NULL)
418 			return -ENETUNREACH;
419 		ifp = ifa->ifa_ifp;
420 		ifa_free(ifa);
421 		if (bcast || multi)
422 			goto mcast;
423 	}
424 	/*
425 	 * Make sure the route exists and has a valid link.
426 	 */
427 	rte = rtalloc1(dst_in, 1, 0);
428 	if (rte == NULL || rte->rt_ifp == NULL || !RT_LINK_IS_UP(rte->rt_ifp)) {
429 		if (rte)
430 			RTFREE_LOCKED(rte);
431 		return -EHOSTUNREACH;
432 	}
433 	/*
434 	 * If it's not multicast or broadcast and the route doesn't match the
435 	 * requested interface return unreachable.  Otherwise fetch the
436 	 * correct interface pointer and unlock the route.
437 	 */
438 	if (multi || bcast) {
439 		if (ifp == NULL)
440 			ifp = rte->rt_ifp;
441 		RTFREE_LOCKED(rte);
442 	} else if (ifp && ifp != rte->rt_ifp) {
443 		RTFREE_LOCKED(rte);
444 		return -ENETUNREACH;
445 	} else {
446 		if (ifp == NULL)
447 			ifp = rte->rt_ifp;
448 		RT_UNLOCK(rte);
449 	}
450 mcast:
451 	if (bcast)
452 		return rdma_copy_addr(addr, ifp, ifp->if_broadcastaddr);
453 	if (multi) {
454 		struct sockaddr *llsa;
455 
456 		error = ifp->if_resolvemulti(ifp, &llsa, dst_in);
457 		if (error)
458 			return -error;
459 		error = rdma_copy_addr(addr, ifp,
460 		    LLADDR((struct sockaddr_dl *)llsa));
461 		free(llsa, M_IFMADDR);
462 		return error;
463 	}
464 	/*
465 	 * Resolve the link local address.
466 	 */
467 	switch (dst_in->sa_family) {
468 #ifdef INET
469 	case AF_INET:
470 		error = arpresolve(ifp, rte, NULL, dst_in, edst, &lle);
471 		break;
472 #endif
473 #ifdef INET6
474 	case AF_INET6:
475 		error = nd6_storelladdr(ifp, NULL, dst_in, (u_char *)edst, &lle);
476 		break;
477 #endif
478 	default:
479 		/* XXX: Shouldn't happen. */
480 		error = -EINVAL;
481 	}
482 	RTFREE(rte);
483 	if (error == 0)
484 		return rdma_copy_addr(addr, ifp, edst);
485 	if (error == EWOULDBLOCK)
486 		return -ENODATA;
487 	return -error;
488 }
489 
490 #endif
491 
process_req(struct work_struct * work)492 static void process_req(struct work_struct *work)
493 {
494 	struct addr_req *req, *temp_req;
495 	struct sockaddr *src_in, *dst_in;
496 	struct list_head done_list;
497 
498 	INIT_LIST_HEAD(&done_list);
499 
500 	mutex_lock(&lock);
501 	list_for_each_entry_safe(req, temp_req, &req_list, list) {
502 		if (req->status == -ENODATA) {
503 			src_in = (struct sockaddr *) &req->src_addr;
504 			dst_in = (struct sockaddr *) &req->dst_addr;
505 			req->status = addr_resolve(src_in, dst_in, req->addr);
506 			if (req->status && time_after_eq(jiffies, req->timeout))
507 				req->status = -ETIMEDOUT;
508 			else if (req->status == -ENODATA)
509 				continue;
510 		}
511 		list_move_tail(&req->list, &done_list);
512 	}
513 
514 	if (!list_empty(&req_list)) {
515 		req = list_entry(req_list.next, struct addr_req, list);
516 		set_timeout(req->timeout);
517 	}
518 	mutex_unlock(&lock);
519 
520 	list_for_each_entry_safe(req, temp_req, &done_list, list) {
521 		list_del(&req->list);
522 		req->callback(req->status, (struct sockaddr *) &req->src_addr,
523 			req->addr, req->context);
524 		put_client(req->client);
525 		kfree(req);
526 	}
527 }
528 
rdma_resolve_ip(struct rdma_addr_client * client,struct sockaddr * src_addr,struct sockaddr * dst_addr,struct rdma_dev_addr * addr,int timeout_ms,void (* callback)(int status,struct sockaddr * src_addr,struct rdma_dev_addr * addr,void * context),void * context)529 int rdma_resolve_ip(struct rdma_addr_client *client,
530 		    struct sockaddr *src_addr, struct sockaddr *dst_addr,
531 		    struct rdma_dev_addr *addr, int timeout_ms,
532 		    void (*callback)(int status, struct sockaddr *src_addr,
533 				     struct rdma_dev_addr *addr, void *context),
534 		    void *context)
535 {
536 	struct sockaddr *src_in, *dst_in;
537 	struct addr_req *req;
538 	int ret = 0;
539 
540 	req = kzalloc(sizeof *req, GFP_KERNEL);
541 	if (!req)
542 		return -ENOMEM;
543 
544 	src_in = (struct sockaddr *) &req->src_addr;
545 	dst_in = (struct sockaddr *) &req->dst_addr;
546 
547 	if (src_addr) {
548 		if (src_addr->sa_family != dst_addr->sa_family) {
549 			ret = -EINVAL;
550 			goto err;
551 		}
552 
553 		memcpy(src_in, src_addr, ip_addr_size(src_addr));
554 	} else {
555 		src_in->sa_family = dst_addr->sa_family;
556 	}
557 
558 	memcpy(dst_in, dst_addr, ip_addr_size(dst_addr));
559 	req->addr = addr;
560 	req->callback = callback;
561 	req->context = context;
562 	req->client = client;
563 	atomic_inc(&client->refcount);
564 
565 	req->status = addr_resolve(src_in, dst_in, addr);
566 	switch (req->status) {
567 	case 0:
568 		req->timeout = jiffies;
569 		queue_req(req);
570 		break;
571 	case -ENODATA:
572 		req->timeout = msecs_to_jiffies(timeout_ms) + jiffies;
573 		queue_req(req);
574 		break;
575 	default:
576 		ret = req->status;
577 		atomic_dec(&client->refcount);
578 		goto err;
579 	}
580 	return ret;
581 err:
582 	kfree(req);
583 	return ret;
584 }
585 EXPORT_SYMBOL(rdma_resolve_ip);
586 
rdma_addr_cancel(struct rdma_dev_addr * addr)587 void rdma_addr_cancel(struct rdma_dev_addr *addr)
588 {
589 	struct addr_req *req, *temp_req;
590 
591 	mutex_lock(&lock);
592 	list_for_each_entry_safe(req, temp_req, &req_list, list) {
593 		if (req->addr == addr) {
594 			req->status = -ECANCELED;
595 			req->timeout = jiffies;
596 			list_move(&req->list, &req_list);
597 			set_timeout(req->timeout);
598 			break;
599 		}
600 	}
601 	mutex_unlock(&lock);
602 }
603 EXPORT_SYMBOL(rdma_addr_cancel);
604 
netevent_callback(struct notifier_block * self,unsigned long event,void * ctx)605 static int netevent_callback(struct notifier_block *self, unsigned long event,
606 	void *ctx)
607 {
608 	if (event == NETEVENT_NEIGH_UPDATE) {
609 #ifdef __linux__
610 		struct neighbour *neigh = ctx;
611 
612 		if (neigh->nud_state & NUD_VALID) {
613 			set_timeout(jiffies);
614 		}
615 #else
616 		set_timeout(jiffies);
617 #endif
618 	}
619 	return 0;
620 }
621 
622 static struct notifier_block nb = {
623 	.notifier_call = netevent_callback
624 };
625 
addr_init(void)626 static int __init addr_init(void)
627 {
628 	INIT_DELAYED_WORK(&work, process_req);
629 	addr_wq = create_singlethread_workqueue("ib_addr");
630 	if (!addr_wq)
631 		return -ENOMEM;
632 
633 	register_netevent_notifier(&nb);
634 	return 0;
635 }
636 
addr_cleanup(void)637 static void __exit addr_cleanup(void)
638 {
639 	unregister_netevent_notifier(&nb);
640 	destroy_workqueue(addr_wq);
641 }
642 
643 module_init(addr_init);
644 module_exit(addr_cleanup);
645