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         void *context;
  51         void (*callback)(int status, struct sockaddr *src_addr,
  52                          struct rdma_dev_addr *addr, void *context);
  53         unsigned long timeout;
  54         int status;
  55 };
  56
  57 static void process_req(void *data);
  58
  59 static DEFINE_MUTEX(lock);
  60 static LIST_HEAD(req_list);
  61 static DECLARE_WORK(work, process_req, NULL);
  62 static struct workqueue_struct *addr_wq;
  63
  64 static int copy_addr(struct rdma_dev_addr *dev_addr, struct net_device *dev,
  65                      unsigned char *dst_dev_addr)
  66 {
  67         switch (dev->type) {
  68         case ARPHRD_INFINIBAND:
  69                 dev_addr->dev_type = IB_NODE_CA;
  70                 break;
  71         default:
  72                 return -EADDRNOTAVAIL;
  73         }
  74
  75         memcpy(dev_addr->src_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
  76         memcpy(dev_addr->broadcast, dev->broadcast, MAX_ADDR_LEN);
  77         if (dst_dev_addr)
  78                 memcpy(dev_addr->dst_dev_addr, dst_dev_addr, MAX_ADDR_LEN);
  79         return 0;
  80 }
  81
  82 int rdma_translate_ip(struct sockaddr *addr, struct rdma_dev_addr *dev_addr)
  83 {
  84         struct net_device *dev;
  85         u32 ip = ((struct sockaddr_in *) addr)->sin_addr.s_addr;
  86         int ret;
  87
  88         dev = ip_dev_find(ip);
  89         if (!dev)
  90                 return -EADDRNOTAVAIL;
  91
  92         ret = copy_addr(dev_addr, dev, NULL);
  93         dev_put(dev);
  94         return ret;
  95 }
  96 EXPORT_SYMBOL(rdma_translate_ip);
  97
  98 static void set_timeout(unsigned long time)
  99 {
 100         unsigned long delay;
 101
 102         cancel_delayed_work(&work);
 103
 104         delay = time - jiffies;
 105         if ((long)delay <= 0)
 106                 delay = 1;
 107
 108         queue_delayed_work(addr_wq, &work, delay);
 109 }
 110
 111 static void queue_req(struct addr_req *req)
 112 {
 113         struct addr_req *temp_req;
 114
 115         mutex_lock(&lock);
 116         list_for_each_entry_reverse(temp_req, &req_list, list) {
 117                 if (time_after(req->timeout, temp_req->timeout))
 118                         break;
 119         }
 120
 121         list_add(&req->list, &temp_req->list);
 122
 123         if (req_list.next == &req->list)
 124                 set_timeout(req->timeout);
 125         mutex_unlock(&lock);
 126 }
 127
 128 static void addr_send_arp(struct sockaddr_in *dst_in)
 129 {
 130         struct rtable *rt;
 131         struct flowi fl;
 132         u32 dst_ip = dst_in->sin_addr.s_addr;
 133
 134         memset(&fl, 0, sizeof fl);
 135         fl.nl_u.ip4_u.daddr = dst_ip;
 136         if (ip_route_output_key(&rt, &fl))
 137                 return;
 138
 139         arp_send(ARPOP_REQUEST, ETH_P_ARP, rt->rt_gateway, rt->idev->dev,
 140                  rt->rt_src, NULL, rt->idev->dev->dev_addr, NULL);
 141         ip_rt_put(rt);
 142 }
 143
 144 static int addr_resolve_remote(struct sockaddr_in *src_in,
 145                                struct sockaddr_in *dst_in,
 146                                struct rdma_dev_addr *addr)
 147 {
 148         u32 src_ip = src_in->sin_addr.s_addr;
 149         u32 dst_ip = dst_in->sin_addr.s_addr;
 150         struct flowi fl;
 151         struct rtable *rt;
 152         struct neighbour *neigh;
 153         int ret;
 154
 155         memset(&fl, 0, sizeof fl);
 156         fl.nl_u.ip4_u.daddr = dst_ip;
 157         fl.nl_u.ip4_u.saddr = src_ip;
 158         ret = ip_route_output_key(&rt, &fl);
 159         if (ret)
 160                 goto out;
 161
 162         /* If the device does ARP internally, return 'done' */
 163         if (rt->idev->dev->flags & IFF_NOARP) {
 164                 copy_addr(addr, rt->idev->dev, NULL);
 165                 goto put;
 166         }
 167
 168         neigh = neigh_lookup(&arp_tbl, &rt->rt_gateway, rt->idev->dev);
 169         if (!neigh) {
 170                 ret = -ENODATA;
 171                 goto put;
 172         }
 173
 174         if (!(neigh->nud_state & NUD_VALID)) {
 175                 ret = -ENODATA;
 176                 goto release;
 177         }
 178
 179         if (!src_ip) {
 180                 src_in->sin_family = dst_in->sin_family;
 181                 src_in->sin_addr.s_addr = rt->rt_src;
 182         }
 183
 184         ret = copy_addr(addr, neigh->dev, neigh->ha);
 185 release:
 186         neigh_release(neigh);
 187 put:
 188         ip_rt_put(rt);
 189 out:
 190         return ret;
 191 }
 192
 193 static void process_req(void *data)
 194 {
 195         struct addr_req *req, *temp_req;
 196         struct sockaddr_in *src_in, *dst_in;
 197         struct list_head done_list;
 198
 199         INIT_LIST_HEAD(&done_list);
 200
 201         mutex_lock(&lock);
 202         list_for_each_entry_safe(req, temp_req, &req_list, list) {
 203                 if (req->status) {
 204                         src_in = (struct sockaddr_in *) &req->src_addr;
 205                         dst_in = (struct sockaddr_in *) &req->dst_addr;
 206                         req->status = addr_resolve_remote(src_in, dst_in,
 207                                                           req->addr);
 208                 }
 209                 if (req->status && time_after(jiffies, req->timeout))
 210                         req->status = -ETIMEDOUT;
 211                 else if (req->status == -ENODATA)
 212                         continue;
 213
 214                 list_del(&req->list);
 215                 list_add_tail(&req->list, &done_list);
 216         }
 217
 218         if (!list_empty(&req_list)) {
 219                 req = list_entry(req_list.next, struct addr_req, list);
 220                 set_timeout(req->timeout);
 221         }
 222         mutex_unlock(&lock);
 223
 224         list_for_each_entry_safe(req, temp_req, &done_list, list) {
 225                 list_del(&req->list);
 226                 req->callback(req->status, &req->src_addr, req->addr,
 227                               req->context);
 228                 kfree(req);
 229         }
 230 }
 231
 232 static int addr_resolve_local(struct sockaddr_in *src_in,
 233                               struct sockaddr_in *dst_in,
 234                               struct rdma_dev_addr *addr)
 235 {
 236         struct net_device *dev;
 237         u32 src_ip = src_in->sin_addr.s_addr;
 238         u32 dst_ip = dst_in->sin_addr.s_addr;
 239         int ret;
 240
 241         dev = ip_dev_find(dst_ip);
 242         if (!dev)
 243                 return -EADDRNOTAVAIL;
 244
 245         if (ZERONET(src_ip)) {
 246                 src_in->sin_family = dst_in->sin_family;
 247                 src_in->sin_addr.s_addr = dst_ip;
 248                 ret = copy_addr(addr, dev, dev->dev_addr);
 249         } else if (LOOPBACK(src_ip)) {
 250                 ret = rdma_translate_ip((struct sockaddr *)dst_in, addr);
 251                 if (!ret)
 252                         memcpy(addr->dst_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
 253         } else {
 254                 ret = rdma_translate_ip((struct sockaddr *)src_in, addr);
 255                 if (!ret)
 256                         memcpy(addr->dst_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
 257         }
 258
 259         dev_put(dev);
 260         return ret;
 261 }
 262
 263 int rdma_resolve_ip(struct sockaddr *src_addr, struct sockaddr *dst_addr,
 264                     struct rdma_dev_addr *addr, int timeout_ms,
 265                     void (*callback)(int status, struct sockaddr *src_addr,
 266                                      struct rdma_dev_addr *addr, void *context),
 267                     void *context)
 268 {
 269         struct sockaddr_in *src_in, *dst_in;
 270         struct addr_req *req;
 271         int ret = 0;
 272
 273         req = kmalloc(sizeof *req, GFP_KERNEL);
 274         if (!req)
 275                 return -ENOMEM;
 276         memset(req, 0, sizeof *req);
 277
 278         if (src_addr)
 279                 memcpy(&req->src_addr, src_addr, ip_addr_size(src_addr));
 280         memcpy(&req->dst_addr, dst_addr, ip_addr_size(dst_addr));
 281         req->addr = addr;
 282         req->callback = callback;
 283         req->context = context;
 284
 285         src_in = (struct sockaddr_in *) &req->src_addr;
 286         dst_in = (struct sockaddr_in *) &req->dst_addr;
 287
 288         req->status = addr_resolve_local(src_in, dst_in, addr);
 289         if (req->status == -EADDRNOTAVAIL)
 290                 req->status = addr_resolve_remote(src_in, dst_in, addr);
 291
 292         switch (req->status) {
 293         case 0:
 294                 req->timeout = jiffies;
 295                 queue_req(req);
 296                 break;
 297         case -ENODATA:
 298                 req->timeout = msecs_to_jiffies(timeout_ms) + jiffies;
 299                 queue_req(req);
 300                 addr_send_arp(dst_in);
 301                 break;
 302         default:
 303                 ret = req->status;
 304                 kfree(req);
 305                 break;
 306         }
 307         return ret;
 308 }
 309 EXPORT_SYMBOL(rdma_resolve_ip);
 310
 311 void rdma_addr_cancel(struct rdma_dev_addr *addr)
 312 {
 313         struct addr_req *req, *temp_req;
 314
 315         mutex_lock(&lock);
 316         list_for_each_entry_safe(req, temp_req, &req_list, list) {
 317                 if (req->addr == addr) {
 318                         req->status = -ECANCELED;
 319                         req->timeout = jiffies;
 320                         list_del(&req->list);
 321                         list_add(&req->list, &req_list);
 322                         set_timeout(req->timeout);
 323                         break;
 324                 }
 325         }
 326         mutex_unlock(&lock);
 327 }
 328 EXPORT_SYMBOL(rdma_addr_cancel);
 329
 330 static int netevent_callback(struct notifier_block *self, unsigned long event,
 331         void *ctx)
 332 {
 333         if (event == NETEVENT_NEIGH_UPDATE) {
 334                 struct neighbour *neigh = ctx;
 335
 336                 if (neigh->dev->type == ARPHRD_INFINIBAND &&
 337                     (neigh->nud_state & NUD_VALID)) {
 338                         set_timeout(jiffies);
 339                 }
 340         }
 341         return 0;
 342 }
 343
 344 static struct notifier_block nb = {
 345         .notifier_call = netevent_callback
 346 };
 347
 348 static int addr_init(void)
 349 {
 350         addr_wq = create_singlethread_workqueue("ib_addr_wq");
 351         if (!addr_wq)
 352                 return -ENOMEM;
 353
 354         register_netevent_notifier(&nb);
 355         return 0;
 356 }
 357
 358 static void addr_cleanup(void)
 359 {
 360         unregister_netevent_notifier(&nb);
 361         destroy_workqueue(addr_wq);
 362 }
 363
 364 module_init(addr_init);
 365 module_exit(addr_cleanup);