net/tipc/ib_media.c

   1 /*
   2  * net/tipc/ib_media.c: Infiniband bearer support for TIPC
   3  *
   4  * Copyright (c) 2013 Patrick McHardy <kaber@trash.net>
   5  *
   6  * Based on eth_media.c, which carries the following copyright notice:
   7  *
   8  * Copyright (c) 2001-2007, Ericsson AB
   9  * Copyright (c) 2005-2008, 2011, Wind River Systems
  10  * All rights reserved.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions are met:
  14  *
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 3. Neither the names of the copyright holders nor the names of its
  21  *    contributors may be used to endorse or promote products derived from
  22  *    this software without specific prior written permission.
  23  *
  24  * Alternatively, this software may be distributed under the terms of the
  25  * GNU General Public License ("GPL") version 2 as published by the Free
  26  * Software Foundation.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  29  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  31  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  32  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  33  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  34  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  35  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  36  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  37  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  38  * POSSIBILITY OF SUCH DAMAGE.
  39  */
  40
  41 #include <linux/if_infiniband.h>
  42 #include "core.h"
  43 #include "bearer.h"
  44
  45 #define MAX_IB_BEARERS          MAX_BEARERS
  46
  47 /**
  48  * struct ib_bearer - Infiniband bearer data structure
  49  * @bearer: ptr to associated "generic" bearer structure
  50  * @dev: ptr to associated Infiniband network device
  51  * @tipc_packet_type: used in binding TIPC to Infiniband driver
  52  * @cleanup: work item used when disabling bearer
  53  */
  54
  55 struct ib_bearer {
  56         struct tipc_bearer *bearer;
  57         struct net_device *dev;
  58         struct packet_type tipc_packet_type;
  59         struct work_struct setup;
  60         struct work_struct cleanup;
  61 };
  62
  63 static struct tipc_media ib_media_info;
  64 static struct ib_bearer ib_bearers[MAX_IB_BEARERS];
  65 static int ib_started;
  66
  67 /**
  68  * ib_media_addr_set - initialize Infiniband media address structure
  69  *
  70  * Media-dependent "value" field stores MAC address in first 6 bytes
  71  * and zeroes out the remaining bytes.
  72  */
  73 static void ib_media_addr_set(const struct tipc_bearer *tb_ptr,
  74                               struct tipc_media_addr *a, char *mac)
  75 {
  76         BUILD_BUG_ON(sizeof(a->value) < INFINIBAND_ALEN);
  77         memcpy(a->value, mac, INFINIBAND_ALEN);
  78         a->media_id = TIPC_MEDIA_TYPE_IB;
  79         a->broadcast = !memcmp(mac, tb_ptr->bcast_addr.value, INFINIBAND_ALEN);
  80 }
  81
  82 /**
  83  * send_msg - send a TIPC message out over an InfiniBand interface
  84  */
  85 static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr,
  86                     struct tipc_media_addr *dest)
  87 {
  88         struct sk_buff *clone;
  89         struct net_device *dev;
  90         int delta;
  91
  92         clone = skb_clone(buf, GFP_ATOMIC);
  93         if (!clone)
  94                 return 0;
  95
  96         dev = ((struct ib_bearer *)(tb_ptr->usr_handle))->dev;
  97         delta = dev->hard_header_len - skb_headroom(buf);
  98
  99         if ((delta > 0) &&
 100             pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
 101                 kfree_skb(clone);
 102                 return 0;
 103         }
 104
 105         skb_reset_network_header(clone);
 106         clone->dev = dev;
 107         clone->protocol = htons(ETH_P_TIPC);
 108         dev_hard_header(clone, dev, ETH_P_TIPC, dest->value,
 109                         dev->dev_addr, clone->len);
 110         dev_queue_xmit(clone);
 111         return 0;
 112 }
 113
 114 /**
 115  * recv_msg - handle incoming TIPC message from an InfiniBand interface
 116  *
 117  * Accept only packets explicitly sent to this node, or broadcast packets;
 118  * ignores packets sent using InfiniBand multicast, and traffic sent to other
 119  * nodes (which can happen if interface is running in promiscuous mode).
 120  */
 121 static int recv_msg(struct sk_buff *buf, struct net_device *dev,
 122                     struct packet_type *pt, struct net_device *orig_dev)
 123 {
 124         struct ib_bearer *ib_ptr = (struct ib_bearer *)pt->af_packet_priv;
 125
 126         if (!net_eq(dev_net(dev), &init_net)) {
 127                 kfree_skb(buf);
 128                 return 0;
 129         }
 130
 131         if (likely(ib_ptr->bearer)) {
 132                 if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
 133                         buf->next = NULL;
 134                         tipc_recv_msg(buf, ib_ptr->bearer);
 135                         return 0;
 136                 }
 137         }
 138         kfree_skb(buf);
 139         return 0;
 140 }
 141
 142 /**
 143  * setup_bearer - setup association between InfiniBand bearer and interface
 144  */
 145 static void setup_bearer(struct work_struct *work)
 146 {
 147         struct ib_bearer *ib_ptr =
 148                 container_of(work, struct ib_bearer, setup);
 149
 150         dev_add_pack(&ib_ptr->tipc_packet_type);
 151 }
 152
 153 /**
 154  * enable_bearer - attach TIPC bearer to an InfiniBand interface
 155  */
 156 static int enable_bearer(struct tipc_bearer *tb_ptr)
 157 {
 158         struct net_device *dev = NULL;
 159         struct net_device *pdev = NULL;
 160         struct ib_bearer *ib_ptr = &ib_bearers[0];
 161         struct ib_bearer *stop = &ib_bearers[MAX_IB_BEARERS];
 162         char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1;
 163         int pending_dev = 0;
 164
 165         /* Find unused InfiniBand bearer structure */
 166         while (ib_ptr->dev) {
 167                 if (!ib_ptr->bearer)
 168                         pending_dev++;
 169                 if (++ib_ptr == stop)
 170                         return pending_dev ? -EAGAIN : -EDQUOT;
 171         }
 172
 173         /* Find device with specified name */
 174         read_lock(&dev_base_lock);
 175         for_each_netdev(&init_net, pdev) {
 176                 if (!strncmp(pdev->name, driver_name, IFNAMSIZ)) {
 177                         dev = pdev;
 178                         dev_hold(dev);
 179                         break;
 180                 }
 181         }
 182         read_unlock(&dev_base_lock);
 183         if (!dev)
 184                 return -ENODEV;
 185
 186         /* Create InfiniBand bearer for device */
 187         ib_ptr->dev = dev;
 188         ib_ptr->tipc_packet_type.type = htons(ETH_P_TIPC);
 189         ib_ptr->tipc_packet_type.dev = dev;
 190         ib_ptr->tipc_packet_type.func = recv_msg;
 191         ib_ptr->tipc_packet_type.af_packet_priv = ib_ptr;
 192         INIT_LIST_HEAD(&(ib_ptr->tipc_packet_type.list));
 193         INIT_WORK(&ib_ptr->setup, setup_bearer);
 194         schedule_work(&ib_ptr->setup);
 195
 196         /* Associate TIPC bearer with InfiniBand bearer */
 197         ib_ptr->bearer = tb_ptr;
 198         tb_ptr->usr_handle = (void *)ib_ptr;
 199         memset(tb_ptr->bcast_addr.value, 0, sizeof(tb_ptr->bcast_addr.value));
 200         memcpy(tb_ptr->bcast_addr.value, dev->broadcast, INFINIBAND_ALEN);
 201         tb_ptr->bcast_addr.media_id = TIPC_MEDIA_TYPE_IB;
 202         tb_ptr->bcast_addr.broadcast = 1;
 203         tb_ptr->mtu = dev->mtu;
 204         tb_ptr->blocked = 0;
 205         ib_media_addr_set(tb_ptr, &tb_ptr->addr, (char *)dev->dev_addr);
 206         return 0;
 207 }
 208
 209 /**
 210  * cleanup_bearer - break association between InfiniBand bearer and interface
 211  *
 212  * This routine must be invoked from a work queue because it can sleep.
 213  */
 214 static void cleanup_bearer(struct work_struct *work)
 215 {
 216         struct ib_bearer *ib_ptr =
 217                 container_of(work, struct ib_bearer, cleanup);
 218
 219         dev_remove_pack(&ib_ptr->tipc_packet_type);
 220         dev_put(ib_ptr->dev);
 221         ib_ptr->dev = NULL;
 222 }
 223
 224 /**
 225  * disable_bearer - detach TIPC bearer from an InfiniBand interface
 226  *
 227  * Mark InfiniBand bearer as inactive so that incoming buffers are thrown away,
 228  * then get worker thread to complete bearer cleanup.  (Can't do cleanup
 229  * here because cleanup code needs to sleep and caller holds spinlocks.)
 230  */
 231 static void disable_bearer(struct tipc_bearer *tb_ptr)
 232 {
 233         struct ib_bearer *ib_ptr = (struct ib_bearer *)tb_ptr->usr_handle;
 234
 235         ib_ptr->bearer = NULL;
 236         INIT_WORK(&ib_ptr->cleanup, cleanup_bearer);
 237         schedule_work(&ib_ptr->cleanup);
 238 }
 239
 240 /**
 241  * recv_notification - handle device updates from OS
 242  *
 243  * Change the state of the InfiniBand bearer (if any) associated with the
 244  * specified device.
 245  */
 246 static int recv_notification(struct notifier_block *nb, unsigned long evt,
 247                              void *dv)
 248 {
 249         struct net_device *dev = (struct net_device *)dv;
 250         struct ib_bearer *ib_ptr = &ib_bearers[0];
 251         struct ib_bearer *stop = &ib_bearers[MAX_IB_BEARERS];
 252
 253         if (!net_eq(dev_net(dev), &init_net))
 254                 return NOTIFY_DONE;
 255
 256         while ((ib_ptr->dev != dev)) {
 257                 if (++ib_ptr == stop)
 258                         return NOTIFY_DONE;     /* couldn't find device */
 259         }
 260         if (!ib_ptr->bearer)
 261                 return NOTIFY_DONE;             /* bearer had been disabled */
 262
 263         ib_ptr->bearer->mtu = dev->mtu;
 264
 265         switch (evt) {
 266         case NETDEV_CHANGE:
 267                 if (netif_carrier_ok(dev))
 268                         tipc_continue(ib_ptr->bearer);
 269                 else
 270                         tipc_block_bearer(ib_ptr->bearer->name);
 271                 break;
 272         case NETDEV_UP:
 273                 tipc_continue(ib_ptr->bearer);
 274                 break;
 275         case NETDEV_DOWN:
 276                 tipc_block_bearer(ib_ptr->bearer->name);
 277                 break;
 278         case NETDEV_CHANGEMTU:
 279         case NETDEV_CHANGEADDR:
 280                 tipc_block_bearer(ib_ptr->bearer->name);
 281                 tipc_continue(ib_ptr->bearer);
 282                 break;
 283         case NETDEV_UNREGISTER:
 284         case NETDEV_CHANGENAME:
 285                 tipc_disable_bearer(ib_ptr->bearer->name);
 286                 break;
 287         }
 288         return NOTIFY_OK;
 289 }
 290
 291 static struct notifier_block notifier = {
 292         .notifier_call  = recv_notification,
 293         .priority       = 0,
 294 };
 295
 296 /**
 297  * ib_addr2str - convert InfiniBand address to string
 298  */
 299 static int ib_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size)
 300 {
 301         if (str_size < 60)      /* 60 = 19 * strlen("xx:") + strlen("xx\0") */
 302                 return 1;
 303
 304         sprintf(str_buf, "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:"
 305                          "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x",
 306                 a->value[0], a->value[1], a->value[2], a->value[3],
 307                 a->value[4], a->value[5], a->value[6], a->value[7],
 308                 a->value[8], a->value[9], a->value[10], a->value[11],
 309                 a->value[12], a->value[13], a->value[14], a->value[15],
 310                 a->value[16], a->value[17], a->value[18], a->value[19]);
 311
 312         return 0;
 313 }
 314
 315 /**
 316  * ib_addr2msg - convert InfiniBand address format to message header format
 317  */
 318 static int ib_addr2msg(struct tipc_media_addr *a, char *msg_area)
 319 {
 320         memset(msg_area, 0, TIPC_MEDIA_ADDR_SIZE);
 321         msg_area[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_IB;
 322         memcpy(msg_area, a->value, INFINIBAND_ALEN);
 323         return 0;
 324 }
 325
 326 /**
 327  * ib_msg2addr - convert message header address format to InfiniBand format
 328  */
 329 static int ib_msg2addr(const struct tipc_bearer *tb_ptr,
 330                        struct tipc_media_addr *a, char *msg_area)
 331 {
 332         ib_media_addr_set(tb_ptr, a, msg_area);
 333         return 0;
 334 }
 335
 336 /*
 337  * InfiniBand media registration info
 338  */
 339 static struct tipc_media ib_media_info = {
 340         .send_msg       = send_msg,
 341         .enable_bearer  = enable_bearer,
 342         .disable_bearer = disable_bearer,
 343         .addr2str       = ib_addr2str,
 344         .addr2msg       = ib_addr2msg,
 345         .msg2addr       = ib_msg2addr,
 346         .priority       = TIPC_DEF_LINK_PRI,
 347         .tolerance      = TIPC_DEF_LINK_TOL,
 348         .window         = TIPC_DEF_LINK_WIN,
 349         .type_id        = TIPC_MEDIA_TYPE_IB,
 350         .name           = "ib"
 351 };
 352
 353 /**
 354  * tipc_ib_media_start - activate InfiniBand bearer support
 355  *
 356  * Register InfiniBand media type with TIPC bearer code.  Also register
 357  * with OS for notifications about device state changes.
 358  */
 359 int tipc_ib_media_start(void)
 360 {
 361         int res;
 362
 363         if (ib_started)
 364                 return -EINVAL;
 365
 366         res = tipc_register_media(&ib_media_info);
 367         if (res)
 368                 return res;
 369
 370         res = register_netdevice_notifier(&notifier);
 371         if (!res)
 372                 ib_started = 1;
 373         return res;
 374 }
 375
 376 /**
 377  * tipc_ib_media_stop - deactivate InfiniBand bearer support
 378  */
 379 void tipc_ib_media_stop(void)
 380 {
 381         if (!ib_started)
 382                 return;
 383
 384         flush_scheduled_work();
 385         unregister_netdevice_notifier(&notifier);
 386         ib_started = 0;
 387 }