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 licensed under one of the following licenses:
   8  *
   9  * 1) under the terms of the "Common Public License 1.0" a copy of which is
  10  *    available from the Open Source Initiative, see
  11  *    http://www.opensource.org/licenses/cpl.php.
  12  *
  13  * 2) under the terms of the "The BSD License" a copy of which is
  14  *    available from the Open Source Initiative, see
  15  *    http://www.opensource.org/licenses/bsd-license.php.
  16  *
  17  * 3) under the terms of the "GNU General Public License (GPL) Version 2" a
  18  *    copy of which is available from the Open Source Initiative, see
  19  *    http://www.opensource.org/licenses/gpl-license.php.
  20  *
  21  * Licensee has the right to choose one of the above licenses.
  22  *
  23  * Redistributions of source code must retain the above copyright
  24  * notice and one of the license notices.
  25  *
  26  * Redistributions in binary form must reproduce both the above copyright
  27  * notice, one of the license notices in the documentation
  28  * and/or other materials provided with the distribution.
  29  */
  30
  31 #include <linux/mutex.h>
  32 #include <linux/inetdevice.h>
  33 #include <linux/workqueue.h>
  34 #include <linux/if_arp.h>
  35 #include <net/arp.h>
  36 #include <net/neighbour.h>
  37 #include <net/route.h>
  38 #include <net/netevent.h>
  39 #include <rdma/ib_addr.h>
  40
  41 MODULE_AUTHOR("Sean Hefty");
  42 MODULE_DESCRIPTION("IB Address Translation");
  43 MODULE_LICENSE("Dual BSD/GPL");
  44
  45 struct addr_req {
  46         struct list_head list;
  47         struct sockaddr src_addr;
  48         struct sockaddr dst_addr;
  49         struct rdma_dev_addr *addr;
  50         struct rdma_addr_client *client;
  51         void *context;
  52         void (*callback)(int status, struct sockaddr *src_addr,
  53                          struct rdma_dev_addr *addr, void *context);
  54         unsigned long timeout;
  55         int status;
  56 };
  57
  58 static void process_req(struct work_struct *work);
  59
  60 static DEFINE_MUTEX(lock);
  61 static LIST_HEAD(req_list);
  62 static DECLARE_DELAYED_WORK(work, process_req);
  63 static struct workqueue_struct *addr_wq;
  64
  65 void rdma_addr_register_client(struct rdma_addr_client *client)
  66 {
  67         atomic_set(&client->refcount, 1);
  68         init_completion(&client->comp);
  69 }
  70 EXPORT_SYMBOL(rdma_addr_register_client);
  71
  72 static inline void put_client(struct rdma_addr_client *client)
  73 {
  74         if (atomic_dec_and_test(&client->refcount))
  75                 complete(&client->comp);
  76 }
  77
  78 void rdma_addr_unregister_client(struct rdma_addr_client *client)
  79 {
  80         put_client(client);
  81         wait_for_completion(&client->comp);
  82 }
  83 EXPORT_SYMBOL(rdma_addr_unregister_client);
  84
  85 int rdma_copy_addr(struct rdma_dev_addr *dev_addr, struct net_device *dev,
  86                      const unsigned char *dst_dev_addr)
  87 {
  88         switch (dev->type) {
  89         case ARPHRD_INFINIBAND:
  90                 dev_addr->dev_type = RDMA_NODE_IB_CA;
  91                 break;
  92         case ARPHRD_ETHER:
  93                 dev_addr->dev_type = RDMA_NODE_RNIC;
  94                 break;
  95         default:
  96                 return -EADDRNOTAVAIL;
  97         }
  98
  99         memcpy(dev_addr->src_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
 100         memcpy(dev_addr->broadcast, dev->broadcast, MAX_ADDR_LEN);
 101         if (dst_dev_addr)
 102                 memcpy(dev_addr->dst_dev_addr, dst_dev_addr, MAX_ADDR_LEN);
 103         return 0;
 104 }
 105 EXPORT_SYMBOL(rdma_copy_addr);
 106
 107 int rdma_translate_ip(struct sockaddr *addr, struct rdma_dev_addr *dev_addr)
 108 {
 109         struct net_device *dev;
 110         __be32 ip = ((struct sockaddr_in *) addr)->sin_addr.s_addr;
 111         int ret;
 112
 113         dev = ip_dev_find(ip);
 114         if (!dev)
 115                 return -EADDRNOTAVAIL;
 116
 117         ret = rdma_copy_addr(dev_addr, dev, NULL);
 118         dev_put(dev);
 119         return ret;
 120 }
 121 EXPORT_SYMBOL(rdma_translate_ip);
 122
 123 static void set_timeout(unsigned long time)
 124 {
 125         unsigned long delay;
 126
 127         cancel_delayed_work(&work);
 128
 129         delay = time - jiffies;
 130         if ((long)delay <= 0)
 131                 delay = 1;
 132
 133         queue_delayed_work(addr_wq, &work, delay);
 134 }
 135
 136 static void queue_req(struct addr_req *req)
 137 {
 138         struct addr_req *temp_req;
 139
 140         mutex_lock(&lock);
 141         list_for_each_entry_reverse(temp_req, &req_list, list) {
 142                 if (time_after_eq(req->timeout, temp_req->timeout))
 143                         break;
 144         }
 145
 146         list_add(&req->list, &temp_req->list);
 147
 148         if (req_list.next == &req->list)
 149                 set_timeout(req->timeout);
 150         mutex_unlock(&lock);
 151 }
 152
 153 static void addr_send_arp(struct sockaddr_in *dst_in)
 154 {
 155         struct rtable *rt;
 156         struct flowi fl;
 157         u32 dst_ip = dst_in->sin_addr.s_addr;
 158
 159         memset(&fl, 0, sizeof fl);
 160         fl.nl_u.ip4_u.daddr = dst_ip;
 161         if (ip_route_output_key(&rt, &fl))
 162                 return;
 163
 164         arp_send(ARPOP_REQUEST, ETH_P_ARP, rt->rt_gateway, rt->idev->dev,
 165                  rt->rt_src, NULL, rt->idev->dev->dev_addr, NULL);
 166         ip_rt_put(rt);
 167 }
 168
 169 static int addr_resolve_remote(struct sockaddr_in *src_in,
 170                                struct sockaddr_in *dst_in,
 171                                struct rdma_dev_addr *addr)
 172 {
 173         u32 src_ip = src_in->sin_addr.s_addr;
 174         u32 dst_ip = dst_in->sin_addr.s_addr;
 175         struct flowi fl;
 176         struct rtable *rt;
 177         struct neighbour *neigh;
 178         int ret;
 179
 180         memset(&fl, 0, sizeof fl);
 181         fl.nl_u.ip4_u.daddr = dst_ip;
 182         fl.nl_u.ip4_u.saddr = src_ip;
 183         ret = ip_route_output_key(&rt, &fl);
 184         if (ret)
 185                 goto out;
 186
 187         /* If the device does ARP internally, return 'done' */
 188         if (rt->idev->dev->flags & IFF_NOARP) {
 189                 rdma_copy_addr(addr, rt->idev->dev, NULL);
 190                 goto put;
 191         }
 192
 193         neigh = neigh_lookup(&arp_tbl, &rt->rt_gateway, rt->idev->dev);
 194         if (!neigh) {
 195                 ret = -ENODATA;
 196                 goto put;
 197         }
 198
 199         if (!(neigh->nud_state & NUD_VALID)) {
 200                 ret = -ENODATA;
 201                 goto release;
 202         }
 203
 204         if (!src_ip) {
 205                 src_in->sin_family = dst_in->sin_family;
 206                 src_in->sin_addr.s_addr = rt->rt_src;
 207         }
 208
 209         ret = rdma_copy_addr(addr, neigh->dev, neigh->ha);
 210 release:
 211         neigh_release(neigh);
 212 put:
 213         ip_rt_put(rt);
 214 out:
 215         return ret;
 216 }
 217
 218 static void process_req(struct work_struct *work)
 219 {
 220         struct addr_req *req, *temp_req;
 221         struct sockaddr_in *src_in, *dst_in;
 222         struct list_head done_list;
 223
 224         INIT_LIST_HEAD(&done_list);
 225
 226         mutex_lock(&lock);
 227         list_for_each_entry_safe(req, temp_req, &req_list, list) {
 228                 if (req->status == -ENODATA) {
 229                         src_in = (struct sockaddr_in *) &req->src_addr;
 230                         dst_in = (struct sockaddr_in *) &req->dst_addr;
 231                         req->status = addr_resolve_remote(src_in, dst_in,
 232                                                           req->addr);
 233                         if (req->status && time_after_eq(jiffies, req->timeout))
 234                                 req->status = -ETIMEDOUT;
 235                         else if (req->status == -ENODATA)
 236                                 continue;
 237                 }
 238                 list_move_tail(&req->list, &done_list);
 239         }
 240
 241         if (!list_empty(&req_list)) {
 242                 req = list_entry(req_list.next, struct addr_req, list);
 243                 set_timeout(req->timeout);
 244         }
 245         mutex_unlock(&lock);
 246
 247         list_for_each_entry_safe(req, temp_req, &done_list, list) {
 248                 list_del(&req->list);
 249                 req->callback(req->status, &req->src_addr, req->addr,
 250                               req->context);
 251                 put_client(req->client);
 252                 kfree(req);
 253         }
 254 }
 255
 256 static int addr_resolve_local(struct sockaddr_in *src_in,
 257                               struct sockaddr_in *dst_in,
 258                               struct rdma_dev_addr *addr)
 259 {
 260         struct net_device *dev;
 261         u32 src_ip = src_in->sin_addr.s_addr;
 262         __be32 dst_ip = dst_in->sin_addr.s_addr;
 263         int ret;
 264
 265         dev = ip_dev_find(dst_ip);
 266         if (!dev)
 267                 return -EADDRNOTAVAIL;
 268
 269         if (ZERONET(src_ip)) {
 270                 src_in->sin_family = dst_in->sin_family;
 271                 src_in->sin_addr.s_addr = dst_ip;
 272                 ret = rdma_copy_addr(addr, dev, dev->dev_addr);
 273         } else if (LOOPBACK(src_ip)) {
 274                 ret = rdma_translate_ip((struct sockaddr *)dst_in, addr);
 275                 if (!ret)
 276                         memcpy(addr->dst_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
 277         } else {
 278                 ret = rdma_translate_ip((struct sockaddr *)src_in, addr);
 279                 if (!ret)
 280                         memcpy(addr->dst_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
 281         }
 282
 283         dev_put(dev);
 284         return ret;
 285 }
 286
 287 int rdma_resolve_ip(struct rdma_addr_client *client,
 288                     struct sockaddr *src_addr, struct sockaddr *dst_addr,
 289                     struct rdma_dev_addr *addr, int timeout_ms,
 290                     void (*callback)(int status, struct sockaddr *src_addr,
 291                                      struct rdma_dev_addr *addr, void *context),
 292                     void *context)
 293 {
 294         struct sockaddr_in *src_in, *dst_in;
 295         struct addr_req *req;
 296         int ret = 0;
 297
 298         req = kmalloc(sizeof *req, GFP_KERNEL);
 299         if (!req)
 300                 return -ENOMEM;
 301         memset(req, 0, sizeof *req);
 302
 303         if (src_addr)
 304                 memcpy(&req->src_addr, src_addr, ip_addr_size(src_addr));
 305         memcpy(&req->dst_addr, dst_addr, ip_addr_size(dst_addr));
 306         req->addr = addr;
 307         req->callback = callback;
 308         req->context = context;
 309         req->client = client;
 310         atomic_inc(&client->refcount);
 311
 312         src_in = (struct sockaddr_in *) &req->src_addr;
 313         dst_in = (struct sockaddr_in *) &req->dst_addr;
 314
 315         req->status = addr_resolve_local(src_in, dst_in, addr);
 316         if (req->status == -EADDRNOTAVAIL)
 317                 req->status = addr_resolve_remote(src_in, dst_in, addr);
 318
 319         switch (req->status) {
 320         case 0:
 321                 req->timeout = jiffies;
 322                 queue_req(req);
 323                 break;
 324         case -ENODATA:
 325                 req->timeout = msecs_to_jiffies(timeout_ms) + jiffies;
 326                 queue_req(req);
 327                 addr_send_arp(dst_in);
 328                 break;
 329         default:
 330                 ret = req->status;
 331                 atomic_dec(&client->refcount);
 332                 kfree(req);
 333                 break;
 334         }
 335         return ret;
 336 }
 337 EXPORT_SYMBOL(rdma_resolve_ip);
 338
 339 void rdma_addr_cancel(struct rdma_dev_addr *addr)
 340 {
 341         struct addr_req *req, *temp_req;
 342
 343         mutex_lock(&lock);
 344         list_for_each_entry_safe(req, temp_req, &req_list, list) {
 345                 if (req->addr == addr) {
 346                         req->status = -ECANCELED;
 347                         req->timeout = jiffies;
 348                         list_move(&req->list, &req_list);
 349                         set_timeout(req->timeout);
 350                         break;
 351                 }
 352         }
 353         mutex_unlock(&lock);
 354 }
 355 EXPORT_SYMBOL(rdma_addr_cancel);
 356
 357 static int netevent_callback(struct notifier_block *self, unsigned long event,
 358         void *ctx)
 359 {
 360         if (event == NETEVENT_NEIGH_UPDATE) {
 361                 struct neighbour *neigh = ctx;
 362
 363                 if (neigh->nud_state & NUD_VALID) {
 364                         set_timeout(jiffies);
 365                 }
 366         }
 367         return 0;
 368 }
 369
 370 static struct notifier_block nb = {
 371         .notifier_call = netevent_callback
 372 };
 373
 374 static int addr_init(void)
 375 {
 376         addr_wq = create_singlethread_workqueue("ib_addr");
 377         if (!addr_wq)
 378                 return -ENOMEM;
 379
 380         register_netevent_notifier(&nb);
 381         return 0;
 382 }
 383
 384 static void addr_cleanup(void)
 385 {
 386         unregister_netevent_notifier(&nb);
 387         destroy_workqueue(addr_wq);
 388 }
 389
 390 module_init(addr_init);
 391 module_exit(addr_cleanup);