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/workqueue.h>
  39 #include <linux/if_arp.h>
  40 #include <net/arp.h>
  41 #include <net/neighbour.h>
  42 #include <net/route.h>
  43 #include <net/netevent.h>
  44 #include <rdma/ib_addr.h>
  45
  46 MODULE_AUTHOR("Sean Hefty");
  47 MODULE_DESCRIPTION("IB Address Translation");
  48 MODULE_LICENSE("Dual BSD/GPL");
  49
  50 struct addr_req {
  51         struct list_head list;
  52         struct sockaddr src_addr;
  53         struct sockaddr dst_addr;
  54         struct rdma_dev_addr *addr;
  55         struct rdma_addr_client *client;
  56         void *context;
  57         void (*callback)(int status, struct sockaddr *src_addr,
  58                          struct rdma_dev_addr *addr, void *context);
  59         unsigned long timeout;
  60         int status;
  61 };
  62
  63 static void process_req(struct work_struct *work);
  64
  65 static DEFINE_MUTEX(lock);
  66 static LIST_HEAD(req_list);
  67 static DECLARE_DELAYED_WORK(work, process_req);
  68 static struct workqueue_struct *addr_wq;
  69
  70 void rdma_addr_register_client(struct rdma_addr_client *client)
  71 {
  72         atomic_set(&client->refcount, 1);
  73         init_completion(&client->comp);
  74 }
  75 EXPORT_SYMBOL(rdma_addr_register_client);
  76
  77 static inline void put_client(struct rdma_addr_client *client)
  78 {
  79         if (atomic_dec_and_test(&client->refcount))
  80                 complete(&client->comp);
  81 }
  82
  83 void rdma_addr_unregister_client(struct rdma_addr_client *client)
  84 {
  85         put_client(client);
  86         wait_for_completion(&client->comp);
  87 }
  88 EXPORT_SYMBOL(rdma_addr_unregister_client);
  89
  90 int rdma_copy_addr(struct rdma_dev_addr *dev_addr, struct net_device *dev,
  91                      const unsigned char *dst_dev_addr)
  92 {
  93         switch (dev->type) {
  94         case ARPHRD_INFINIBAND:
  95                 dev_addr->dev_type = RDMA_NODE_IB_CA;
  96                 break;
  97         case ARPHRD_ETHER:
  98                 dev_addr->dev_type = RDMA_NODE_RNIC;
  99                 break;
 100         default:
 101                 return -EADDRNOTAVAIL;
 102         }
 103
 104         memcpy(dev_addr->src_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
 105         memcpy(dev_addr->broadcast, dev->broadcast, MAX_ADDR_LEN);
 106         if (dst_dev_addr)
 107                 memcpy(dev_addr->dst_dev_addr, dst_dev_addr, MAX_ADDR_LEN);
 108         dev_addr->src_dev = dev;
 109         return 0;
 110 }
 111 EXPORT_SYMBOL(rdma_copy_addr);
 112
 113 int rdma_translate_ip(struct sockaddr *addr, struct rdma_dev_addr *dev_addr)
 114 {
 115         struct net_device *dev;
 116         __be32 ip = ((struct sockaddr_in *) addr)->sin_addr.s_addr;
 117         int ret;
 118
 119         dev = ip_dev_find(&init_net, ip);
 120         if (!dev)
 121                 return -EADDRNOTAVAIL;
 122
 123         ret = rdma_copy_addr(dev_addr, dev, NULL);
 124         dev_put(dev);
 125         return ret;
 126 }
 127 EXPORT_SYMBOL(rdma_translate_ip);
 128
 129 static void set_timeout(unsigned long time)
 130 {
 131         unsigned long delay;
 132
 133         cancel_delayed_work(&work);
 134
 135         delay = time - jiffies;
 136         if ((long)delay <= 0)
 137                 delay = 1;
 138
 139         queue_delayed_work(addr_wq, &work, delay);
 140 }
 141
 142 static void queue_req(struct addr_req *req)
 143 {
 144         struct addr_req *temp_req;
 145
 146         mutex_lock(&lock);
 147         list_for_each_entry_reverse(temp_req, &req_list, list) {
 148                 if (time_after_eq(req->timeout, temp_req->timeout))
 149                         break;
 150         }
 151
 152         list_add(&req->list, &temp_req->list);
 153
 154         if (req_list.next == &req->list)
 155                 set_timeout(req->timeout);
 156         mutex_unlock(&lock);
 157 }
 158
 159 static void addr_send_arp(struct sockaddr_in *dst_in)
 160 {
 161         struct rtable *rt;
 162         struct flowi fl;
 163         __be32 dst_ip = dst_in->sin_addr.s_addr;
 164
 165         memset(&fl, 0, sizeof fl);
 166         fl.nl_u.ip4_u.daddr = dst_ip;
 167         if (ip_route_output_key(&init_net, &rt, &fl))
 168                 return;
 169
 170         neigh_event_send(rt->u.dst.neighbour, NULL);
 171         ip_rt_put(rt);
 172 }
 173
 174 static int addr_resolve_remote(struct sockaddr_in *src_in,
 175                                struct sockaddr_in *dst_in,
 176                                struct rdma_dev_addr *addr)
 177 {
 178         __be32 src_ip = src_in->sin_addr.s_addr;
 179         __be32 dst_ip = dst_in->sin_addr.s_addr;
 180         struct flowi fl;
 181         struct rtable *rt;
 182         struct neighbour *neigh;
 183         int ret;
 184
 185         memset(&fl, 0, sizeof fl);
 186         fl.nl_u.ip4_u.daddr = dst_ip;
 187         fl.nl_u.ip4_u.saddr = src_ip;
 188         ret = ip_route_output_key(&init_net, &rt, &fl);
 189         if (ret)
 190                 goto out;
 191
 192         /* If the device does ARP internally, return 'done' */
 193         if (rt->idev->dev->flags & IFF_NOARP) {
 194                 rdma_copy_addr(addr, rt->idev->dev, NULL);
 195                 goto put;
 196         }
 197
 198         neigh = neigh_lookup(&arp_tbl, &rt->rt_gateway, rt->idev->dev);
 199         if (!neigh) {
 200                 ret = -ENODATA;
 201                 goto put;
 202         }
 203
 204         if (!(neigh->nud_state & NUD_VALID)) {
 205                 ret = -ENODATA;
 206                 goto release;
 207         }
 208
 209         if (!src_ip) {
 210                 src_in->sin_family = dst_in->sin_family;
 211                 src_in->sin_addr.s_addr = rt->rt_src;
 212         }
 213
 214         ret = rdma_copy_addr(addr, neigh->dev, neigh->ha);
 215 release:
 216         neigh_release(neigh);
 217 put:
 218         ip_rt_put(rt);
 219 out:
 220         return ret;
 221 }
 222
 223 static void process_req(struct work_struct *work)
 224 {
 225         struct addr_req *req, *temp_req;
 226         struct sockaddr_in *src_in, *dst_in;
 227         struct list_head done_list;
 228
 229         INIT_LIST_HEAD(&done_list);
 230
 231         mutex_lock(&lock);
 232         list_for_each_entry_safe(req, temp_req, &req_list, list) {
 233                 if (req->status == -ENODATA) {
 234                         src_in = (struct sockaddr_in *) &req->src_addr;
 235                         dst_in = (struct sockaddr_in *) &req->dst_addr;
 236                         req->status = addr_resolve_remote(src_in, dst_in,
 237                                                           req->addr);
 238                         if (req->status && time_after_eq(jiffies, req->timeout))
 239                                 req->status = -ETIMEDOUT;
 240                         else if (req->status == -ENODATA)
 241                                 continue;
 242                 }
 243                 list_move_tail(&req->list, &done_list);
 244         }
 245
 246         if (!list_empty(&req_list)) {
 247                 req = list_entry(req_list.next, struct addr_req, list);
 248                 set_timeout(req->timeout);
 249         }
 250         mutex_unlock(&lock);
 251
 252         list_for_each_entry_safe(req, temp_req, &done_list, list) {
 253                 list_del(&req->list);
 254                 req->callback(req->status, &req->src_addr, req->addr,
 255                               req->context);
 256                 put_client(req->client);
 257                 kfree(req);
 258         }
 259 }
 260
 261 static int addr_resolve_local(struct sockaddr_in *src_in,
 262                               struct sockaddr_in *dst_in,
 263                               struct rdma_dev_addr *addr)
 264 {
 265         struct net_device *dev;
 266         __be32 src_ip = src_in->sin_addr.s_addr;
 267         __be32 dst_ip = dst_in->sin_addr.s_addr;
 268         int ret;
 269
 270         dev = ip_dev_find(&init_net, dst_ip);
 271         if (!dev)
 272                 return -EADDRNOTAVAIL;
 273
 274         if (ipv4_is_zeronet(src_ip)) {
 275                 src_in->sin_family = dst_in->sin_family;
 276                 src_in->sin_addr.s_addr = dst_ip;
 277                 ret = rdma_copy_addr(addr, dev, dev->dev_addr);
 278         } else if (ipv4_is_loopback(src_ip)) {
 279                 ret = rdma_translate_ip((struct sockaddr *)dst_in, addr);
 280                 if (!ret)
 281                         memcpy(addr->dst_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
 282         } else {
 283                 ret = rdma_translate_ip((struct sockaddr *)src_in, addr);
 284                 if (!ret)
 285                         memcpy(addr->dst_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
 286         }
 287
 288         dev_put(dev);
 289         return ret;
 290 }
 291
 292 int rdma_resolve_ip(struct rdma_addr_client *client,
 293                     struct sockaddr *src_addr, struct sockaddr *dst_addr,
 294                     struct rdma_dev_addr *addr, int timeout_ms,
 295                     void (*callback)(int status, struct sockaddr *src_addr,
 296                                      struct rdma_dev_addr *addr, void *context),
 297                     void *context)
 298 {
 299         struct sockaddr_in *src_in, *dst_in;
 300         struct addr_req *req;
 301         int ret = 0;
 302
 303         req = kzalloc(sizeof *req, GFP_KERNEL);
 304         if (!req)
 305                 return -ENOMEM;
 306
 307         if (src_addr)
 308                 memcpy(&req->src_addr, src_addr, ip_addr_size(src_addr));
 309         memcpy(&req->dst_addr, dst_addr, ip_addr_size(dst_addr));
 310         req->addr = addr;
 311         req->callback = callback;
 312         req->context = context;
 313         req->client = client;
 314         atomic_inc(&client->refcount);
 315
 316         src_in = (struct sockaddr_in *) &req->src_addr;
 317         dst_in = (struct sockaddr_in *) &req->dst_addr;
 318
 319         req->status = addr_resolve_local(src_in, dst_in, addr);
 320         if (req->status == -EADDRNOTAVAIL)
 321                 req->status = addr_resolve_remote(src_in, dst_in, addr);
 322
 323         switch (req->status) {
 324         case 0:
 325                 req->timeout = jiffies;
 326                 queue_req(req);
 327                 break;
 328         case -ENODATA:
 329                 req->timeout = msecs_to_jiffies(timeout_ms) + jiffies;
 330                 queue_req(req);
 331                 addr_send_arp(dst_in);
 332                 break;
 333         default:
 334                 ret = req->status;
 335                 atomic_dec(&client->refcount);
 336                 kfree(req);
 337                 break;
 338         }
 339         return ret;
 340 }
 341 EXPORT_SYMBOL(rdma_resolve_ip);
 342
 343 void rdma_addr_cancel(struct rdma_dev_addr *addr)
 344 {
 345         struct addr_req *req, *temp_req;
 346
 347         mutex_lock(&lock);
 348         list_for_each_entry_safe(req, temp_req, &req_list, list) {
 349                 if (req->addr == addr) {
 350                         req->status = -ECANCELED;
 351                         req->timeout = jiffies;
 352                         list_move(&req->list, &req_list);
 353                         set_timeout(req->timeout);
 354                         break;
 355                 }
 356         }
 357         mutex_unlock(&lock);
 358 }
 359 EXPORT_SYMBOL(rdma_addr_cancel);
 360
 361 static int netevent_callback(struct notifier_block *self, unsigned long event,
 362         void *ctx)
 363 {
 364         if (event == NETEVENT_NEIGH_UPDATE) {
 365                 struct neighbour *neigh = ctx;
 366
 367                 if (neigh->nud_state & NUD_VALID) {
 368                         set_timeout(jiffies);
 369                 }
 370         }
 371         return 0;
 372 }
 373
 374 static struct notifier_block nb = {
 375         .notifier_call = netevent_callback
 376 };
 377
 378 static int addr_init(void)
 379 {
 380         addr_wq = create_singlethread_workqueue("ib_addr");
 381         if (!addr_wq)
 382                 return -ENOMEM;
 383
 384         register_netevent_notifier(&nb);
 385         return 0;
 386 }
 387
 388 static void addr_cleanup(void)
 389 {
 390         unregister_netevent_notifier(&nb);
 391         destroy_workqueue(addr_wq);
 392 }
 393
 394 module_init(addr_init);
 395 module_exit(addr_cleanup);