drivers/infiniband/core/addr.c

   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 <net/arp.h>
  42 #include <net/neighbour.h>
  43 #include <net/route.h>
  44 #include <net/netevent.h>
  45 #include <net/addrconf.h>
  46 #include <net/ip6_route.h>
  47 #include <rdma/ib_addr.h>
  48 #include <rdma/ib.h>
  49
  50 MODULE_AUTHOR("Sean Hefty");
  51 MODULE_DESCRIPTION("IB Address Translation");
  52 MODULE_LICENSE("Dual BSD/GPL");
  53
  54 struct addr_req {
  55         struct list_head list;
  56         struct sockaddr_storage src_addr;
  57         struct sockaddr_storage dst_addr;
  58         struct rdma_dev_addr *addr;
  59         struct rdma_addr_client *client;
  60         void *context;
  61         void (*callback)(int status, struct sockaddr *src_addr,
  62                          struct rdma_dev_addr *addr, void *context);
  63         unsigned long timeout;
  64         int status;
  65 };
  66
  67 static void process_req(struct work_struct *work);
  68
  69 static DEFINE_MUTEX(lock);
  70 static LIST_HEAD(req_list);
  71 static DECLARE_DELAYED_WORK(work, process_req);
  72 static struct workqueue_struct *addr_wq;
  73
  74 int rdma_addr_size(struct sockaddr *addr)
  75 {
  76         switch (addr->sa_family) {
  77         case AF_INET:
  78                 return sizeof(struct sockaddr_in);
  79         case AF_INET6:
  80                 return sizeof(struct sockaddr_in6);
  81         case AF_IB:
  82                 return sizeof(struct sockaddr_ib);
  83         default:
  84                 return 0;
  85         }
  86 }
  87 EXPORT_SYMBOL(rdma_addr_size);
  88
  89 static struct rdma_addr_client self;
  90
  91 void rdma_addr_register_client(struct rdma_addr_client *client)
  92 {
  93         atomic_set(&client->refcount, 1);
  94         init_completion(&client->comp);
  95 }
  96 EXPORT_SYMBOL(rdma_addr_register_client);
  97
  98 static inline void put_client(struct rdma_addr_client *client)
  99 {
 100         if (atomic_dec_and_test(&client->refcount))
 101                 complete(&client->comp);
 102 }
 103
 104 void rdma_addr_unregister_client(struct rdma_addr_client *client)
 105 {
 106         put_client(client);
 107         wait_for_completion(&client->comp);
 108 }
 109 EXPORT_SYMBOL(rdma_addr_unregister_client);
 110
 111 int rdma_copy_addr(struct rdma_dev_addr *dev_addr, struct net_device *dev,
 112                      const unsigned char *dst_dev_addr)
 113 {
 114         dev_addr->dev_type = dev->type;
 115         memcpy(dev_addr->src_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
 116         memcpy(dev_addr->broadcast, dev->broadcast, MAX_ADDR_LEN);
 117         if (dst_dev_addr)
 118                 memcpy(dev_addr->dst_dev_addr, dst_dev_addr, MAX_ADDR_LEN);
 119         dev_addr->bound_dev_if = dev->ifindex;
 120         return 0;
 121 }
 122 EXPORT_SYMBOL(rdma_copy_addr);
 123
 124 int rdma_translate_ip(const struct sockaddr *addr,
 125                       struct rdma_dev_addr *dev_addr,
 126                       u16 *vlan_id)
 127 {
 128         struct net_device *dev;
 129         int ret = -EADDRNOTAVAIL;
 130
 131         if (dev_addr->bound_dev_if) {
 132                 dev = dev_get_by_index(dev_addr->net, dev_addr->bound_dev_if);
 133                 if (!dev)
 134                         return -ENODEV;
 135                 ret = rdma_copy_addr(dev_addr, dev, NULL);
 136                 dev_put(dev);
 137                 return ret;
 138         }
 139
 140         switch (addr->sa_family) {
 141         case AF_INET:
 142                 dev = ip_dev_find(dev_addr->net,
 143                         ((const 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                 if (vlan_id)
 150                         *vlan_id = rdma_vlan_dev_vlan_id(dev);
 151                 dev_put(dev);
 152                 break;
 153 #if IS_ENABLED(CONFIG_IPV6)
 154         case AF_INET6:
 155                 rcu_read_lock();
 156                 for_each_netdev_rcu(dev_addr->net, dev) {
 157                         if (ipv6_chk_addr(dev_addr->net,
 158                                           &((const struct sockaddr_in6 *)addr)->sin6_addr,
 159                                           dev, 1)) {
 160                                 ret = rdma_copy_addr(dev_addr, dev, NULL);
 161                                 if (vlan_id)
 162                                         *vlan_id = rdma_vlan_dev_vlan_id(dev);
 163                                 break;
 164                         }
 165                 }
 166                 rcu_read_unlock();
 167                 break;
 168 #endif
 169         }
 170         return ret;
 171 }
 172 EXPORT_SYMBOL(rdma_translate_ip);
 173
 174 static void set_timeout(unsigned long time)
 175 {
 176         unsigned long delay;
 177
 178         delay = time - jiffies;
 179         if ((long)delay < 0)
 180                 delay = 0;
 181
 182         mod_delayed_work(addr_wq, &work, delay);
 183 }
 184
 185 static void queue_req(struct addr_req *req)
 186 {
 187         struct addr_req *temp_req;
 188
 189         mutex_lock(&lock);
 190         list_for_each_entry_reverse(temp_req, &req_list, list) {
 191                 if (time_after_eq(req->timeout, temp_req->timeout))
 192                         break;
 193         }
 194
 195         list_add(&req->list, &temp_req->list);
 196
 197         if (req_list.next == &req->list)
 198                 set_timeout(req->timeout);
 199         mutex_unlock(&lock);
 200 }
 201
 202 static int dst_fetch_ha(struct dst_entry *dst, struct rdma_dev_addr *dev_addr,
 203                         const void *daddr)
 204 {
 205         struct neighbour *n;
 206         int ret;
 207
 208         n = dst_neigh_lookup(dst, daddr);
 209
 210         rcu_read_lock();
 211         if (!n || !(n->nud_state & NUD_VALID)) {
 212                 if (n)
 213                         neigh_event_send(n, NULL);
 214                 ret = -ENODATA;
 215         } else {
 216                 ret = rdma_copy_addr(dev_addr, dst->dev, n->ha);
 217         }
 218         rcu_read_unlock();
 219
 220         if (n)
 221                 neigh_release(n);
 222
 223         return ret;
 224 }
 225
 226 static int addr4_resolve(struct sockaddr_in *src_in,
 227                          const struct sockaddr_in *dst_in,
 228                          struct rdma_dev_addr *addr,
 229                          struct rtable **prt)
 230 {
 231         __be32 src_ip = src_in->sin_addr.s_addr;
 232         __be32 dst_ip = dst_in->sin_addr.s_addr;
 233         struct rtable *rt;
 234         struct flowi4 fl4;
 235         int ret;
 236
 237         memset(&fl4, 0, sizeof(fl4));
 238         fl4.daddr = dst_ip;
 239         fl4.saddr = src_ip;
 240         fl4.flowi4_oif = addr->bound_dev_if;
 241         rt = ip_route_output_key(addr->net, &fl4);
 242         if (IS_ERR(rt)) {
 243                 ret = PTR_ERR(rt);
 244                 goto out;
 245         }
 246         src_in->sin_family = AF_INET;
 247         src_in->sin_addr.s_addr = fl4.saddr;
 248
 249         /* If there's a gateway, we're definitely in RoCE v2 (as RoCE v1 isn't
 250          * routable) and we could set the network type accordingly.
 251          */
 252         if (rt->rt_uses_gateway)
 253                 addr->network = RDMA_NETWORK_IPV4;
 254
 255         addr->hoplimit = ip4_dst_hoplimit(&rt->dst);
 256
 257         *prt = rt;
 258         return 0;
 259 out:
 260         return ret;
 261 }
 262
 263 #if IS_ENABLED(CONFIG_IPV6)
 264 static int addr6_resolve(struct sockaddr_in6 *src_in,
 265                          const struct sockaddr_in6 *dst_in,
 266                          struct rdma_dev_addr *addr,
 267                          struct dst_entry **pdst)
 268 {
 269         struct flowi6 fl6;
 270         struct dst_entry *dst;
 271         struct rt6_info *rt;
 272         int ret;
 273
 274         memset(&fl6, 0, sizeof fl6);
 275         fl6.daddr = dst_in->sin6_addr;
 276         fl6.saddr = src_in->sin6_addr;
 277         fl6.flowi6_oif = addr->bound_dev_if;
 278
 279         dst = ip6_route_output(addr->net, NULL, &fl6);
 280         if ((ret = dst->error))
 281                 goto put;
 282
 283         rt = (struct rt6_info *)dst;
 284         if (ipv6_addr_any(&fl6.saddr)) {
 285                 ret = ipv6_dev_get_saddr(addr->net, ip6_dst_idev(dst)->dev,
 286                                          &fl6.daddr, 0, &fl6.saddr);
 287                 if (ret)
 288                         goto put;
 289
 290                 src_in->sin6_family = AF_INET6;
 291                 src_in->sin6_addr = fl6.saddr;
 292         }
 293
 294         /* If there's a gateway, we're definitely in RoCE v2 (as RoCE v1 isn't
 295          * routable) and we could set the network type accordingly.
 296          */
 297         if (rt->rt6i_flags & RTF_GATEWAY)
 298                 addr->network = RDMA_NETWORK_IPV6;
 299
 300         addr->hoplimit = ip6_dst_hoplimit(dst);
 301
 302         *pdst = dst;
 303         return 0;
 304 put:
 305         dst_release(dst);
 306         return ret;
 307 }
 308 #else
 309 static int addr6_resolve(struct sockaddr_in6 *src_in,
 310                          const struct sockaddr_in6 *dst_in,
 311                          struct rdma_dev_addr *addr,
 312                          struct dst_entry **pdst)
 313 {
 314         return -EADDRNOTAVAIL;
 315 }
 316 #endif
 317
 318 static int addr_resolve_neigh(struct dst_entry *dst,
 319                               const struct sockaddr *dst_in,
 320                               struct rdma_dev_addr *addr)
 321 {
 322         if (dst->dev->flags & IFF_LOOPBACK) {
 323                 int ret;
 324
 325                 ret = rdma_translate_ip(dst_in, addr, NULL);
 326                 if (!ret)
 327                         memcpy(addr->dst_dev_addr, addr->src_dev_addr,
 328                                MAX_ADDR_LEN);
 329
 330                 return ret;
 331         }
 332
 333         /* If the device doesn't do ARP internally */
 334         if (!(dst->dev->flags & IFF_NOARP)) {
 335                 const struct sockaddr_in *dst_in4 =
 336                         (const struct sockaddr_in *)dst_in;
 337                 const struct sockaddr_in6 *dst_in6 =
 338                         (const struct sockaddr_in6 *)dst_in;
 339
 340                 return dst_fetch_ha(dst, addr,
 341                                     dst_in->sa_family == AF_INET ?
 342                                     (const void *)&dst_in4->sin_addr.s_addr :
 343                                     (const void *)&dst_in6->sin6_addr);
 344         }
 345
 346         return rdma_copy_addr(addr, dst->dev, NULL);
 347 }
 348
 349 static int addr_resolve(struct sockaddr *src_in,
 350                         const struct sockaddr *dst_in,
 351                         struct rdma_dev_addr *addr,
 352                         bool resolve_neigh)
 353 {
 354         struct net_device *ndev;
 355         struct dst_entry *dst;
 356         int ret;
 357
 358         if (src_in->sa_family == AF_INET) {
 359                 struct rtable *rt = NULL;
 360                 const struct sockaddr_in *dst_in4 =
 361                         (const struct sockaddr_in *)dst_in;
 362
 363                 ret = addr4_resolve((struct sockaddr_in *)src_in,
 364                                     dst_in4, addr, &rt);
 365                 if (ret)
 366                         return ret;
 367
 368                 if (resolve_neigh)
 369                         ret = addr_resolve_neigh(&rt->dst, dst_in, addr);
 370
 371                 ndev = rt->dst.dev;
 372                 dev_hold(ndev);
 373
 374                 ip_rt_put(rt);
 375         } else {
 376                 const struct sockaddr_in6 *dst_in6 =
 377                         (const struct sockaddr_in6 *)dst_in;
 378
 379                 ret = addr6_resolve((struct sockaddr_in6 *)src_in,
 380                                     dst_in6, addr,
 381                                     &dst);
 382                 if (ret)
 383                         return ret;
 384
 385                 if (resolve_neigh)
 386                         ret = addr_resolve_neigh(dst, dst_in, addr);
 387
 388                 ndev = dst->dev;
 389                 dev_hold(ndev);
 390
 391                 dst_release(dst);
 392         }
 393
 394         addr->bound_dev_if = ndev->ifindex;
 395         addr->net = dev_net(ndev);
 396         dev_put(ndev);
 397
 398         return ret;
 399 }
 400
 401 static void process_req(struct work_struct *work)
 402 {
 403         struct addr_req *req, *temp_req;
 404         struct sockaddr *src_in, *dst_in;
 405         struct list_head done_list;
 406
 407         INIT_LIST_HEAD(&done_list);
 408
 409         mutex_lock(&lock);
 410         list_for_each_entry_safe(req, temp_req, &req_list, list) {
 411                 if (req->status == -ENODATA) {
 412                         src_in = (struct sockaddr *) &req->src_addr;
 413                         dst_in = (struct sockaddr *) &req->dst_addr;
 414                         req->status = addr_resolve(src_in, dst_in, req->addr,
 415                                                    true);
 416                         if (req->status && time_after_eq(jiffies, req->timeout))
 417                                 req->status = -ETIMEDOUT;
 418                         else if (req->status == -ENODATA)
 419                                 continue;
 420                 }
 421                 list_move_tail(&req->list, &done_list);
 422         }
 423
 424         if (!list_empty(&req_list)) {
 425                 req = list_entry(req_list.next, struct addr_req, list);
 426                 set_timeout(req->timeout);
 427         }
 428         mutex_unlock(&lock);
 429
 430         list_for_each_entry_safe(req, temp_req, &done_list, list) {
 431                 list_del(&req->list);
 432                 req->callback(req->status, (struct sockaddr *) &req->src_addr,
 433                         req->addr, req->context);
 434                 put_client(req->client);
 435                 kfree(req);
 436         }
 437 }
 438
 439 int rdma_resolve_ip(struct rdma_addr_client *client,
 440                     struct sockaddr *src_addr, struct sockaddr *dst_addr,
 441                     struct rdma_dev_addr *addr, int timeout_ms,
 442                     void (*callback)(int status, struct sockaddr *src_addr,
 443                                      struct rdma_dev_addr *addr, void *context),
 444                     void *context)
 445 {
 446         struct sockaddr *src_in, *dst_in;
 447         struct addr_req *req;
 448         int ret = 0;
 449
 450         req = kzalloc(sizeof *req, GFP_KERNEL);
 451         if (!req)
 452                 return -ENOMEM;
 453
 454         src_in = (struct sockaddr *) &req->src_addr;
 455         dst_in = (struct sockaddr *) &req->dst_addr;
 456
 457         if (src_addr) {
 458                 if (src_addr->sa_family != dst_addr->sa_family) {
 459                         ret = -EINVAL;
 460                         goto err;
 461                 }
 462
 463                 memcpy(src_in, src_addr, rdma_addr_size(src_addr));
 464         } else {
 465                 src_in->sa_family = dst_addr->sa_family;
 466         }
 467
 468         memcpy(dst_in, dst_addr, rdma_addr_size(dst_addr));
 469         req->addr = addr;
 470         req->callback = callback;
 471         req->context = context;
 472         req->client = client;
 473         atomic_inc(&client->refcount);
 474
 475         req->status = addr_resolve(src_in, dst_in, addr, true);
 476         switch (req->status) {
 477         case 0:
 478                 req->timeout = jiffies;
 479                 queue_req(req);
 480                 break;
 481         case -ENODATA:
 482                 req->timeout = msecs_to_jiffies(timeout_ms) + jiffies;
 483                 queue_req(req);
 484                 break;
 485         default:
 486                 ret = req->status;
 487                 atomic_dec(&client->refcount);
 488                 goto err;
 489         }
 490         return ret;
 491 err:
 492         kfree(req);
 493         return ret;
 494 }
 495 EXPORT_SYMBOL(rdma_resolve_ip);
 496
 497 int rdma_resolve_ip_route(struct sockaddr *src_addr,
 498                           const struct sockaddr *dst_addr,
 499                           struct rdma_dev_addr *addr)
 500 {
 501         struct sockaddr_storage ssrc_addr = {};
 502         struct sockaddr *src_in = (struct sockaddr *)&ssrc_addr;
 503
 504         if (src_addr) {
 505                 if (src_addr->sa_family != dst_addr->sa_family)
 506                         return -EINVAL;
 507
 508                 memcpy(src_in, src_addr, rdma_addr_size(src_addr));
 509         } else {
 510                 src_in->sa_family = dst_addr->sa_family;
 511         }
 512
 513         return addr_resolve(src_in, dst_addr, addr, false);
 514 }
 515 EXPORT_SYMBOL(rdma_resolve_ip_route);
 516
 517 void rdma_addr_cancel(struct rdma_dev_addr *addr)
 518 {
 519         struct addr_req *req, *temp_req;
 520
 521         mutex_lock(&lock);
 522         list_for_each_entry_safe(req, temp_req, &req_list, list) {
 523                 if (req->addr == addr) {
 524                         req->status = -ECANCELED;
 525                         req->timeout = jiffies;
 526                         list_move(&req->list, &req_list);
 527                         set_timeout(req->timeout);
 528                         break;
 529                 }
 530         }
 531         mutex_unlock(&lock);
 532 }
 533 EXPORT_SYMBOL(rdma_addr_cancel);
 534
 535 struct resolve_cb_context {
 536         struct rdma_dev_addr *addr;
 537         struct completion comp;
 538 };
 539
 540 static void resolve_cb(int status, struct sockaddr *src_addr,
 541              struct rdma_dev_addr *addr, void *context)
 542 {
 543         memcpy(((struct resolve_cb_context *)context)->addr, addr, sizeof(struct
 544                                 rdma_dev_addr));
 545         complete(&((struct resolve_cb_context *)context)->comp);
 546 }
 547
 548 int rdma_addr_find_l2_eth_by_grh(const union ib_gid *sgid,
 549                                  const union ib_gid *dgid,
 550                                  u8 *dmac, u16 *vlan_id, int *if_index,
 551                                  int *hoplimit)
 552 {
 553         int ret = 0;
 554         struct rdma_dev_addr dev_addr;
 555         struct resolve_cb_context ctx;
 556         struct net_device *dev;
 557
 558         union {
 559                 struct sockaddr     _sockaddr;
 560                 struct sockaddr_in  _sockaddr_in;
 561                 struct sockaddr_in6 _sockaddr_in6;
 562         } sgid_addr, dgid_addr;
 563
 564
 565         rdma_gid2ip(&sgid_addr._sockaddr, sgid);
 566         rdma_gid2ip(&dgid_addr._sockaddr, dgid);
 567
 568         memset(&dev_addr, 0, sizeof(dev_addr));
 569         if (if_index)
 570                 dev_addr.bound_dev_if = *if_index;
 571         dev_addr.net = &init_net;
 572
 573         ctx.addr = &dev_addr;
 574         init_completion(&ctx.comp);
 575         ret = rdma_resolve_ip(&self, &sgid_addr._sockaddr, &dgid_addr._sockaddr,
 576                         &dev_addr, 1000, resolve_cb, &ctx);
 577         if (ret)
 578                 return ret;
 579
 580         wait_for_completion(&ctx.comp);
 581
 582         memcpy(dmac, dev_addr.dst_dev_addr, ETH_ALEN);
 583         dev = dev_get_by_index(&init_net, dev_addr.bound_dev_if);
 584         if (!dev)
 585                 return -ENODEV;
 586         if (if_index)
 587                 *if_index = dev_addr.bound_dev_if;
 588         if (vlan_id)
 589                 *vlan_id = rdma_vlan_dev_vlan_id(dev);
 590         if (hoplimit)
 591                 *hoplimit = dev_addr.hoplimit;
 592         dev_put(dev);
 593         return ret;
 594 }
 595 EXPORT_SYMBOL(rdma_addr_find_l2_eth_by_grh);
 596
 597 int rdma_addr_find_smac_by_sgid(union ib_gid *sgid, u8 *smac, u16 *vlan_id)
 598 {
 599         int ret = 0;
 600         struct rdma_dev_addr dev_addr;
 601         union {
 602                 struct sockaddr     _sockaddr;
 603                 struct sockaddr_in  _sockaddr_in;
 604                 struct sockaddr_in6 _sockaddr_in6;
 605         } gid_addr;
 606
 607         rdma_gid2ip(&gid_addr._sockaddr, sgid);
 608
 609         memset(&dev_addr, 0, sizeof(dev_addr));
 610         dev_addr.net = &init_net;
 611         ret = rdma_translate_ip(&gid_addr._sockaddr, &dev_addr, vlan_id);
 612         if (ret)
 613                 return ret;
 614
 615         memcpy(smac, dev_addr.src_dev_addr, ETH_ALEN);
 616         return ret;
 617 }
 618 EXPORT_SYMBOL(rdma_addr_find_smac_by_sgid);
 619
 620 static int netevent_callback(struct notifier_block *self, unsigned long event,
 621         void *ctx)
 622 {
 623         if (event == NETEVENT_NEIGH_UPDATE) {
 624                 struct neighbour *neigh = ctx;
 625
 626                 if (neigh->nud_state & NUD_VALID) {
 627                         set_timeout(jiffies);
 628                 }
 629         }
 630         return 0;
 631 }
 632
 633 static struct notifier_block nb = {
 634         .notifier_call = netevent_callback
 635 };
 636
 637 static int __init addr_init(void)
 638 {
 639         addr_wq = create_singlethread_workqueue("ib_addr");
 640         if (!addr_wq)
 641                 return -ENOMEM;
 642
 643         register_netevent_notifier(&nb);
 644         rdma_addr_register_client(&self);
 645         return 0;
 646 }
 647
 648 static void __exit addr_cleanup(void)
 649 {
 650         rdma_addr_unregister_client(&self);
 651         unregister_netevent_notifier(&nb);
 652         destroy_workqueue(addr_wq);
 653 }
 654
 655 module_init(addr_init);
 656 module_exit(addr_cleanup);