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_MEDIA            MAX_BEARERS
  46
  47 /**
  48  * struct ib_media - Infiniband media 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_media {
  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_media ib_media_array[MAX_IB_MEDIA];
  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_media *)(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_media *ib_ptr = (struct ib_media *)pt->af_packet_priv;
 125
 126         if (!net_eq(dev_net(dev), &init_net)) {
 127                 kfree_skb(buf);
 128                 return NET_RX_DROP;
 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 NET_RX_SUCCESS;
 136                 }
 137         }
 138         kfree_skb(buf);
 139         return NET_RX_DROP;
 140 }
 141
 142 /**
 143  * setup_bearer - setup association between InfiniBand bearer and interface
 144  */
 145 static void setup_media(struct work_struct *work)
 146 {
 147         struct ib_media *ib_ptr =
 148                 container_of(work, struct ib_media, setup);
 149
 150         dev_add_pack(&ib_ptr->tipc_packet_type);
 151 }
 152
 153 /**
 154  * enable_media - attach TIPC bearer to an InfiniBand interface
 155  */
 156 static int enable_media(struct tipc_bearer *tb_ptr)
 157 {
 158         struct net_device *dev;
 159         struct ib_media *ib_ptr = &ib_media_array[0];
 160         struct ib_media *stop = &ib_media_array[MAX_IB_MEDIA];
 161         char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1;
 162         int pending_dev = 0;
 163
 164         /* Find unused InfiniBand bearer structure */
 165         while (ib_ptr->dev) {
 166                 if (!ib_ptr->bearer)
 167                         pending_dev++;
 168                 if (++ib_ptr == stop)
 169                         return pending_dev ? -EAGAIN : -EDQUOT;
 170         }
 171
 172         /* Find device with specified name */
 173         dev = dev_get_by_name(&init_net, driver_name);
 174         if (!dev)
 175                 return -ENODEV;
 176
 177         /* Create InfiniBand bearer for device */
 178         ib_ptr->dev = dev;
 179         ib_ptr->tipc_packet_type.type = htons(ETH_P_TIPC);
 180         ib_ptr->tipc_packet_type.dev = dev;
 181         ib_ptr->tipc_packet_type.func = recv_msg;
 182         ib_ptr->tipc_packet_type.af_packet_priv = ib_ptr;
 183         INIT_LIST_HEAD(&(ib_ptr->tipc_packet_type.list));
 184         INIT_WORK(&ib_ptr->setup, setup_media);
 185         schedule_work(&ib_ptr->setup);
 186
 187         /* Associate TIPC bearer with InfiniBand bearer */
 188         ib_ptr->bearer = tb_ptr;
 189         tb_ptr->usr_handle = (void *)ib_ptr;
 190         memset(tb_ptr->bcast_addr.value, 0, sizeof(tb_ptr->bcast_addr.value));
 191         memcpy(tb_ptr->bcast_addr.value, dev->broadcast, INFINIBAND_ALEN);
 192         tb_ptr->bcast_addr.media_id = TIPC_MEDIA_TYPE_IB;
 193         tb_ptr->bcast_addr.broadcast = 1;
 194         tb_ptr->mtu = dev->mtu;
 195         tb_ptr->blocked = 0;
 196         ib_media_addr_set(tb_ptr, &tb_ptr->addr, (char *)dev->dev_addr);
 197         return 0;
 198 }
 199
 200 /**
 201  * cleanup_bearer - break association between InfiniBand bearer and interface
 202  *
 203  * This routine must be invoked from a work queue because it can sleep.
 204  */
 205 static void cleanup_bearer(struct work_struct *work)
 206 {
 207         struct ib_media *ib_ptr =
 208                 container_of(work, struct ib_media, cleanup);
 209
 210         dev_remove_pack(&ib_ptr->tipc_packet_type);
 211         dev_put(ib_ptr->dev);
 212         ib_ptr->dev = NULL;
 213 }
 214
 215 /**
 216  * disable_media - detach TIPC bearer from an InfiniBand interface
 217  *
 218  * Mark InfiniBand bearer as inactive so that incoming buffers are thrown away,
 219  * then get worker thread to complete bearer cleanup.  (Can't do cleanup
 220  * here because cleanup code needs to sleep and caller holds spinlocks.)
 221  */
 222 static void disable_media(struct tipc_bearer *tb_ptr)
 223 {
 224         struct ib_media *ib_ptr = (struct ib_media *)tb_ptr->usr_handle;
 225
 226         ib_ptr->bearer = NULL;
 227         INIT_WORK(&ib_ptr->cleanup, cleanup_bearer);
 228         schedule_work(&ib_ptr->cleanup);
 229 }
 230
 231 /**
 232  * recv_notification - handle device updates from OS
 233  *
 234  * Change the state of the InfiniBand bearer (if any) associated with the
 235  * specified device.
 236  */
 237 static int recv_notification(struct notifier_block *nb, unsigned long evt,
 238                              void *ptr)
 239 {
 240         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 241         struct ib_media *ib_ptr = &ib_media_array[0];
 242         struct ib_media *stop = &ib_media_array[MAX_IB_MEDIA];
 243
 244         if (!net_eq(dev_net(dev), &init_net))
 245                 return NOTIFY_DONE;
 246
 247         while ((ib_ptr->dev != dev)) {
 248                 if (++ib_ptr == stop)
 249                         return NOTIFY_DONE;     /* couldn't find device */
 250         }
 251         if (!ib_ptr->bearer)
 252                 return NOTIFY_DONE;             /* bearer had been disabled */
 253
 254         ib_ptr->bearer->mtu = dev->mtu;
 255
 256         switch (evt) {
 257         case NETDEV_CHANGE:
 258                 if (netif_carrier_ok(dev))
 259                         tipc_continue(ib_ptr->bearer);
 260                 else
 261                         tipc_block_bearer(ib_ptr->bearer);
 262                 break;
 263         case NETDEV_UP:
 264                 tipc_continue(ib_ptr->bearer);
 265                 break;
 266         case NETDEV_DOWN:
 267                 tipc_block_bearer(ib_ptr->bearer);
 268                 break;
 269         case NETDEV_CHANGEMTU:
 270         case NETDEV_CHANGEADDR:
 271                 tipc_block_bearer(ib_ptr->bearer);
 272                 tipc_continue(ib_ptr->bearer);
 273                 break;
 274         case NETDEV_UNREGISTER:
 275         case NETDEV_CHANGENAME:
 276                 tipc_disable_bearer(ib_ptr->bearer->name);
 277                 break;
 278         }
 279         return NOTIFY_OK;
 280 }
 281
 282 static struct notifier_block notifier = {
 283         .notifier_call  = recv_notification,
 284         .priority       = 0,
 285 };
 286
 287 /**
 288  * ib_addr2str - convert InfiniBand address to string
 289  */
 290 static int ib_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size)
 291 {
 292         if (str_size < 60)      /* 60 = 19 * strlen("xx:") + strlen("xx\0") */
 293                 return 1;
 294
 295         sprintf(str_buf, "%20phC", a->value);
 296
 297         return 0;
 298 }
 299
 300 /**
 301  * ib_addr2msg - convert InfiniBand address format to message header format
 302  */
 303 static int ib_addr2msg(struct tipc_media_addr *a, char *msg_area)
 304 {
 305         memset(msg_area, 0, TIPC_MEDIA_ADDR_SIZE);
 306         msg_area[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_IB;
 307         memcpy(msg_area, a->value, INFINIBAND_ALEN);
 308         return 0;
 309 }
 310
 311 /**
 312  * ib_msg2addr - convert message header address format to InfiniBand format
 313  */
 314 static int ib_msg2addr(const struct tipc_bearer *tb_ptr,
 315                        struct tipc_media_addr *a, char *msg_area)
 316 {
 317         ib_media_addr_set(tb_ptr, a, msg_area);
 318         return 0;
 319 }
 320
 321 /*
 322  * InfiniBand media registration info
 323  */
 324 static struct tipc_media ib_media_info = {
 325         .send_msg       = send_msg,
 326         .enable_media   = enable_media,
 327         .disable_media  = disable_media,
 328         .addr2str       = ib_addr2str,
 329         .addr2msg       = ib_addr2msg,
 330         .msg2addr       = ib_msg2addr,
 331         .priority       = TIPC_DEF_LINK_PRI,
 332         .tolerance      = TIPC_DEF_LINK_TOL,
 333         .window         = TIPC_DEF_LINK_WIN,
 334         .type_id        = TIPC_MEDIA_TYPE_IB,
 335         .name           = "ib"
 336 };
 337
 338 /**
 339  * tipc_ib_media_start - activate InfiniBand bearer support
 340  *
 341  * Register InfiniBand media type with TIPC bearer code.  Also register
 342  * with OS for notifications about device state changes.
 343  */
 344 int tipc_ib_media_start(void)
 345 {
 346         int res;
 347
 348         if (ib_started)
 349                 return -EINVAL;
 350
 351         res = tipc_register_media(&ib_media_info);
 352         if (res)
 353                 return res;
 354
 355         res = register_netdevice_notifier(&notifier);
 356         if (!res)
 357                 ib_started = 1;
 358         return res;
 359 }
 360
 361 /**
 362  * tipc_ib_media_stop - deactivate InfiniBand bearer support
 363  */
 364 void tipc_ib_media_stop(void)
 365 {
 366         if (!ib_started)
 367                 return;
 368
 369         flush_scheduled_work();
 370         unregister_netdevice_notifier(&notifier);
 371         ib_started = 0;
 372 }