linux/net/tipc/eth_media.c
<<
>>
Prefs
   1/*
   2 * net/tipc/eth_media.c: Ethernet bearer support for TIPC
   3 *
   4 * Copyright (c) 2001-2007, Ericsson AB
   5 * Copyright (c) 2005-2008, 2011, Wind River Systems
   6 * All rights reserved.
   7 *
   8 * Redistribution and use in source and binary forms, with or without
   9 * modification, are permitted provided that the following conditions are met:
  10 *
  11 * 1. Redistributions of source code must retain the above copyright
  12 *    notice, this list of conditions and the following disclaimer.
  13 * 2. Redistributions in binary form must reproduce the above copyright
  14 *    notice, this list of conditions and the following disclaimer in the
  15 *    documentation and/or other materials provided with the distribution.
  16 * 3. Neither the names of the copyright holders nor the names of its
  17 *    contributors may be used to endorse or promote products derived from
  18 *    this software without specific prior written permission.
  19 *
  20 * Alternatively, this software may be distributed under the terms of the
  21 * GNU General Public License ("GPL") version 2 as published by the Free
  22 * Software Foundation.
  23 *
  24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34 * POSSIBILITY OF SUCH DAMAGE.
  35 */
  36
  37#include "core.h"
  38#include "bearer.h"
  39
  40#define MAX_ETH_BEARERS         MAX_BEARERS
  41
  42#define ETH_ADDR_OFFSET 4       /* message header offset of MAC address */
  43
  44/**
  45 * struct eth_bearer - Ethernet bearer data structure
  46 * @bearer: ptr to associated "generic" bearer structure
  47 * @dev: ptr to associated Ethernet network device
  48 * @tipc_packet_type: used in binding TIPC to Ethernet driver
  49 * @setup: work item used when enabling bearer
  50 * @cleanup: work item used when disabling bearer
  51 */
  52struct eth_bearer {
  53        struct tipc_bearer *bearer;
  54        struct net_device *dev;
  55        struct packet_type tipc_packet_type;
  56        struct work_struct setup;
  57        struct work_struct cleanup;
  58};
  59
  60static struct tipc_media eth_media_info;
  61static struct eth_bearer eth_bearers[MAX_ETH_BEARERS];
  62static int eth_started;
  63
  64static int recv_notification(struct notifier_block *nb, unsigned long evt,
  65                              void *dv);
  66/*
  67 * Network device notifier info
  68 */
  69static struct notifier_block notifier = {
  70        .notifier_call  = recv_notification,
  71        .priority       = 0
  72};
  73
  74/**
  75 * eth_media_addr_set - initialize Ethernet media address structure
  76 *
  77 * Media-dependent "value" field stores MAC address in first 6 bytes
  78 * and zeroes out the remaining bytes.
  79 */
  80static void eth_media_addr_set(struct tipc_media_addr *a, char *mac)
  81{
  82        memcpy(a->value, mac, ETH_ALEN);
  83        memset(a->value + ETH_ALEN, 0, sizeof(a->value) - ETH_ALEN);
  84        a->media_id = TIPC_MEDIA_TYPE_ETH;
  85        a->broadcast = !memcmp(mac, eth_media_info.bcast_addr.value, ETH_ALEN);
  86}
  87
  88/**
  89 * send_msg - send a TIPC message out over an Ethernet interface
  90 */
  91static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr,
  92                    struct tipc_media_addr *dest)
  93{
  94        struct sk_buff *clone;
  95        struct net_device *dev;
  96        int delta;
  97
  98        clone = skb_clone(buf, GFP_ATOMIC);
  99        if (!clone)
 100                return 0;
 101
 102        dev = ((struct eth_bearer *)(tb_ptr->usr_handle))->dev;
 103        delta = dev->hard_header_len - skb_headroom(buf);
 104
 105        if ((delta > 0) &&
 106            pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
 107                kfree_skb(clone);
 108                return 0;
 109        }
 110
 111        skb_reset_network_header(clone);
 112        clone->dev = dev;
 113        dev_hard_header(clone, dev, ETH_P_TIPC, dest->value,
 114                        dev->dev_addr, clone->len);
 115        dev_queue_xmit(clone);
 116        return 0;
 117}
 118
 119/**
 120 * recv_msg - handle incoming TIPC message from an Ethernet interface
 121 *
 122 * Accept only packets explicitly sent to this node, or broadcast packets;
 123 * ignores packets sent using Ethernet multicast, and traffic sent to other
 124 * nodes (which can happen if interface is running in promiscuous mode).
 125 */
 126static int recv_msg(struct sk_buff *buf, struct net_device *dev,
 127                    struct packet_type *pt, struct net_device *orig_dev)
 128{
 129        struct eth_bearer *eb_ptr = (struct eth_bearer *)pt->af_packet_priv;
 130
 131        if (!net_eq(dev_net(dev), &init_net)) {
 132                kfree_skb(buf);
 133                return 0;
 134        }
 135
 136        if (likely(eb_ptr->bearer)) {
 137                if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
 138                        buf->next = NULL;
 139                        tipc_recv_msg(buf, eb_ptr->bearer);
 140                        return 0;
 141                }
 142        }
 143        kfree_skb(buf);
 144        return 0;
 145}
 146
 147/**
 148 * setup_bearer - setup association between Ethernet bearer and interface
 149 */
 150static void setup_bearer(struct work_struct *work)
 151{
 152        struct eth_bearer *eb_ptr =
 153                container_of(work, struct eth_bearer, setup);
 154
 155        dev_add_pack(&eb_ptr->tipc_packet_type);
 156}
 157
 158/**
 159 * enable_bearer - attach TIPC bearer to an Ethernet interface
 160 */
 161static int enable_bearer(struct tipc_bearer *tb_ptr)
 162{
 163        struct net_device *dev = NULL;
 164        struct net_device *pdev = NULL;
 165        struct eth_bearer *eb_ptr = &eth_bearers[0];
 166        struct eth_bearer *stop = &eth_bearers[MAX_ETH_BEARERS];
 167        char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1;
 168        int pending_dev = 0;
 169
 170        /* Find unused Ethernet bearer structure */
 171        while (eb_ptr->dev) {
 172                if (!eb_ptr->bearer)
 173                        pending_dev++;
 174                if (++eb_ptr == stop)
 175                        return pending_dev ? -EAGAIN : -EDQUOT;
 176        }
 177
 178        /* Find device with specified name */
 179        read_lock(&dev_base_lock);
 180        for_each_netdev(&init_net, pdev) {
 181                if (!strncmp(pdev->name, driver_name, IFNAMSIZ)) {
 182                        dev = pdev;
 183                        dev_hold(dev);
 184                        break;
 185                }
 186        }
 187        read_unlock(&dev_base_lock);
 188        if (!dev)
 189                return -ENODEV;
 190
 191        /* Create Ethernet bearer for device */
 192        eb_ptr->dev = dev;
 193        eb_ptr->tipc_packet_type.type = htons(ETH_P_TIPC);
 194        eb_ptr->tipc_packet_type.dev = dev;
 195        eb_ptr->tipc_packet_type.func = recv_msg;
 196        eb_ptr->tipc_packet_type.af_packet_priv = eb_ptr;
 197        INIT_LIST_HEAD(&(eb_ptr->tipc_packet_type.list));
 198        INIT_WORK(&eb_ptr->setup, setup_bearer);
 199        schedule_work(&eb_ptr->setup);
 200
 201        /* Associate TIPC bearer with Ethernet bearer */
 202        eb_ptr->bearer = tb_ptr;
 203        tb_ptr->usr_handle = (void *)eb_ptr;
 204        tb_ptr->mtu = dev->mtu;
 205        tb_ptr->blocked = 0;
 206        eth_media_addr_set(&tb_ptr->addr, (char *)dev->dev_addr);
 207        return 0;
 208}
 209
 210/**
 211 * cleanup_bearer - break association between Ethernet bearer and interface
 212 *
 213 * This routine must be invoked from a work queue because it can sleep.
 214 */
 215static void cleanup_bearer(struct work_struct *work)
 216{
 217        struct eth_bearer *eb_ptr =
 218                container_of(work, struct eth_bearer, cleanup);
 219
 220        dev_remove_pack(&eb_ptr->tipc_packet_type);
 221        dev_put(eb_ptr->dev);
 222        eb_ptr->dev = NULL;
 223}
 224
 225/**
 226 * disable_bearer - detach TIPC bearer from an Ethernet interface
 227 *
 228 * Mark Ethernet bearer as inactive so that incoming buffers are thrown away,
 229 * then get worker thread to complete bearer cleanup.  (Can't do cleanup
 230 * here because cleanup code needs to sleep and caller holds spinlocks.)
 231 */
 232static void disable_bearer(struct tipc_bearer *tb_ptr)
 233{
 234        struct eth_bearer *eb_ptr = (struct eth_bearer *)tb_ptr->usr_handle;
 235
 236        eb_ptr->bearer = NULL;
 237        INIT_WORK(&eb_ptr->cleanup, cleanup_bearer);
 238        schedule_work(&eb_ptr->cleanup);
 239}
 240
 241/**
 242 * recv_notification - handle device updates from OS
 243 *
 244 * Change the state of the Ethernet bearer (if any) associated with the
 245 * specified device.
 246 */
 247static int recv_notification(struct notifier_block *nb, unsigned long evt,
 248                             void *dv)
 249{
 250        struct net_device *dev = (struct net_device *)dv;
 251        struct eth_bearer *eb_ptr = &eth_bearers[0];
 252        struct eth_bearer *stop = &eth_bearers[MAX_ETH_BEARERS];
 253
 254        if (!net_eq(dev_net(dev), &init_net))
 255                return NOTIFY_DONE;
 256
 257        while ((eb_ptr->dev != dev)) {
 258                if (++eb_ptr == stop)
 259                        return NOTIFY_DONE;     /* couldn't find device */
 260        }
 261        if (!eb_ptr->bearer)
 262                return NOTIFY_DONE;             /* bearer had been disabled */
 263
 264        eb_ptr->bearer->mtu = dev->mtu;
 265
 266        switch (evt) {
 267        case NETDEV_CHANGE:
 268                if (netif_carrier_ok(dev))
 269                        tipc_continue(eb_ptr->bearer);
 270                else
 271                        tipc_block_bearer(eb_ptr->bearer->name);
 272                break;
 273        case NETDEV_UP:
 274                tipc_continue(eb_ptr->bearer);
 275                break;
 276        case NETDEV_DOWN:
 277                tipc_block_bearer(eb_ptr->bearer->name);
 278                break;
 279        case NETDEV_CHANGEMTU:
 280        case NETDEV_CHANGEADDR:
 281                tipc_block_bearer(eb_ptr->bearer->name);
 282                tipc_continue(eb_ptr->bearer);
 283                break;
 284        case NETDEV_UNREGISTER:
 285        case NETDEV_CHANGENAME:
 286                tipc_disable_bearer(eb_ptr->bearer->name);
 287                break;
 288        }
 289        return NOTIFY_OK;
 290}
 291
 292/**
 293 * eth_addr2str - convert Ethernet address to string
 294 */
 295static int eth_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size)
 296{
 297        if (str_size < 18)      /* 18 = strlen("aa:bb:cc:dd:ee:ff\0") */
 298                return 1;
 299
 300        sprintf(str_buf, "%pM", a->value);
 301        return 0;
 302}
 303
 304/**
 305 * eth_str2addr - convert string to Ethernet address
 306 */
 307static int eth_str2addr(struct tipc_media_addr *a, char *str_buf)
 308{
 309        char mac[ETH_ALEN];
 310        int r;
 311
 312        r = sscanf(str_buf, "%02x:%02x:%02x:%02x:%02x:%02x",
 313                       (u32 *)&mac[0], (u32 *)&mac[1], (u32 *)&mac[2],
 314                       (u32 *)&mac[3], (u32 *)&mac[4], (u32 *)&mac[5]);
 315
 316        if (r != ETH_ALEN)
 317                return 1;
 318
 319        eth_media_addr_set(a, mac);
 320        return 0;
 321}
 322
 323/**
 324 * eth_str2addr - convert Ethernet address format to message header format
 325 */
 326static int eth_addr2msg(struct tipc_media_addr *a, char *msg_area)
 327{
 328        memset(msg_area, 0, TIPC_MEDIA_ADDR_SIZE);
 329        msg_area[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_ETH;
 330        memcpy(msg_area + ETH_ADDR_OFFSET, a->value, ETH_ALEN);
 331        return 0;
 332}
 333
 334/**
 335 * eth_str2addr - convert message header address format to Ethernet format
 336 */
 337static int eth_msg2addr(struct tipc_media_addr *a, char *msg_area)
 338{
 339        if (msg_area[TIPC_MEDIA_TYPE_OFFSET] != TIPC_MEDIA_TYPE_ETH)
 340                return 1;
 341
 342        eth_media_addr_set(a, msg_area + ETH_ADDR_OFFSET);
 343        return 0;
 344}
 345
 346/*
 347 * Ethernet media registration info
 348 */
 349static struct tipc_media eth_media_info = {
 350        .send_msg       = send_msg,
 351        .enable_bearer  = enable_bearer,
 352        .disable_bearer = disable_bearer,
 353        .addr2str       = eth_addr2str,
 354        .str2addr       = eth_str2addr,
 355        .addr2msg       = eth_addr2msg,
 356        .msg2addr       = eth_msg2addr,
 357        .bcast_addr     = { { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff },
 358                            TIPC_MEDIA_TYPE_ETH, 1 },
 359        .priority       = TIPC_DEF_LINK_PRI,
 360        .tolerance      = TIPC_DEF_LINK_TOL,
 361        .window         = TIPC_DEF_LINK_WIN,
 362        .type_id        = TIPC_MEDIA_TYPE_ETH,
 363        .name           = "eth"
 364};
 365
 366/**
 367 * tipc_eth_media_start - activate Ethernet bearer support
 368 *
 369 * Register Ethernet media type with TIPC bearer code.  Also register
 370 * with OS for notifications about device state changes.
 371 */
 372int tipc_eth_media_start(void)
 373{
 374        int res;
 375
 376        if (eth_started)
 377                return -EINVAL;
 378
 379        res = tipc_register_media(&eth_media_info);
 380        if (res)
 381                return res;
 382
 383        res = register_netdevice_notifier(&notifier);
 384        if (!res)
 385                eth_started = 1;
 386        return res;
 387}
 388
 389/**
 390 * tipc_eth_media_stop - deactivate Ethernet bearer support
 391 */
 392void tipc_eth_media_stop(void)
 393{
 394        if (!eth_started)
 395                return;
 396
 397        flush_scheduled_work();
 398        unregister_netdevice_notifier(&notifier);
 399        eth_started = 0;
 400}
 401
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.