net/tipc/eth_media.c

   1 /*
   2  * net/tipc/eth_media.c: Ethernet bearer support for TIPC
   3  *
   4  * Copyright (c) 2001-2006, Ericsson AB
   5  * Copyright (c) 2005, 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 <net/tipc/tipc.h>
  38 #include <net/tipc/tipc_bearer.h>
  39 #include <net/tipc/tipc_msg.h>
  40 #include <linux/netdevice.h>
  41 #include <linux/version.h>
  42
  43 #define MAX_ETH_BEARERS         2
  44 #define TIPC_PROTOCOL           0x88ca
  45 #define ETH_LINK_PRIORITY       10
  46 #define ETH_LINK_TOLERANCE      TIPC_DEF_LINK_TOL
  47
  48
  49 /**
  50  * struct eth_bearer - Ethernet bearer data structure
  51  * @bearer: ptr to associated "generic" bearer structure
  52  * @dev: ptr to associated Ethernet network device
  53  * @tipc_packet_type: used in binding TIPC to Ethernet driver
  54  */
  55
  56 struct eth_bearer {
  57         struct tipc_bearer *bearer;
  58         struct net_device *dev;
  59         struct packet_type tipc_packet_type;
  60 };
  61
  62 static struct eth_bearer eth_bearers[MAX_ETH_BEARERS];
  63 static int eth_started = 0;
  64 static struct notifier_block notifier;
  65
  66 /**
  67  * send_msg - send a TIPC message out over an Ethernet interface
  68  */
  69
  70 static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr,
  71                     struct tipc_media_addr *dest)
  72 {
  73         struct sk_buff *clone;
  74         struct net_device *dev;
  75
  76         clone = skb_clone(buf, GFP_ATOMIC);
  77         if (clone) {
  78                 clone->nh.raw = clone->data;
  79                 dev = ((struct eth_bearer *)(tb_ptr->usr_handle))->dev;
  80                 clone->dev = dev;
  81                 dev->hard_header(clone, dev, TIPC_PROTOCOL,
  82                                  &dest->dev_addr.eth_addr,
  83                                  dev->dev_addr, clone->len);
  84                 dev_queue_xmit(clone);
  85         }
  86         return TIPC_OK;
  87 }
  88
  89 /**
  90  * recv_msg - handle incoming TIPC message from an Ethernet interface
  91  *
  92  * Routine truncates any Ethernet padding/CRC appended to the message,
  93  * and ensures message size matches actual length
  94  */
  95
  96 static int recv_msg(struct sk_buff *buf, struct net_device *dev,
  97                     struct packet_type *pt, struct net_device *orig_dev)
  98 {
  99         struct eth_bearer *eb_ptr = (struct eth_bearer *)pt->af_packet_priv;
 100         u32 size;
 101
 102         if (likely(eb_ptr->bearer)) {
 103                 size = msg_size((struct tipc_msg *)buf->data);
 104                 skb_trim(buf, size);
 105                 if (likely(buf->len == size)) {
 106                         buf->next = NULL;
 107                         tipc_recv_msg(buf, eb_ptr->bearer);
 108                 } else {
 109                         kfree_skb(buf);
 110                 }
 111         } else {
 112                 kfree_skb(buf);
 113         }
 114         return TIPC_OK;
 115 }
 116
 117 /**
 118  * enable_bearer - attach TIPC bearer to an Ethernet interface
 119  */
 120
 121 static int enable_bearer(struct tipc_bearer *tb_ptr)
 122 {
 123         struct net_device *dev = dev_base;
 124         struct eth_bearer *eb_ptr = &eth_bearers[0];
 125         struct eth_bearer *stop = &eth_bearers[MAX_ETH_BEARERS];
 126         char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1;
 127
 128         /* Find device with specified name */
 129
 130         while (dev && dev->name &&
 131                (memcmp(dev->name, driver_name, strlen(dev->name)))) {
 132                 dev = dev->next;
 133         }
 134         if (!dev)
 135                 return -ENODEV;
 136
 137         /* Find Ethernet bearer for device (or create one) */
 138
 139         for (;(eb_ptr != stop) && eb_ptr->dev && (eb_ptr->dev != dev); eb_ptr++);
 140         if (eb_ptr == stop)
 141                 return -EDQUOT;
 142         if (!eb_ptr->dev) {
 143                 eb_ptr->dev = dev;
 144                 eb_ptr->tipc_packet_type.type = __constant_htons(TIPC_PROTOCOL);
 145                 eb_ptr->tipc_packet_type.dev = dev;
 146                 eb_ptr->tipc_packet_type.func = recv_msg;
 147                 eb_ptr->tipc_packet_type.af_packet_priv = eb_ptr;
 148                 INIT_LIST_HEAD(&(eb_ptr->tipc_packet_type.list));
 149                 dev_hold(dev);
 150                 dev_add_pack(&eb_ptr->tipc_packet_type);
 151         }
 152
 153         /* Associate TIPC bearer with Ethernet bearer */
 154
 155         eb_ptr->bearer = tb_ptr;
 156         tb_ptr->usr_handle = (void *)eb_ptr;
 157         tb_ptr->mtu = dev->mtu;
 158         tb_ptr->blocked = 0;
 159         tb_ptr->addr.type = htonl(TIPC_MEDIA_TYPE_ETH);
 160         memcpy(&tb_ptr->addr.dev_addr, &dev->dev_addr, ETH_ALEN);
 161         return 0;
 162 }
 163
 164 /**
 165  * disable_bearer - detach TIPC bearer from an Ethernet interface
 166  *
 167  * We really should do dev_remove_pack() here, but this function can not be
 168  * called at tasklet level. => Use eth_bearer->bearer as a flag to throw away
 169  * incoming buffers, & postpone dev_remove_pack() to eth_media_stop() on exit.
 170  */
 171
 172 static void disable_bearer(struct tipc_bearer *tb_ptr)
 173 {
 174         ((struct eth_bearer *)tb_ptr->usr_handle)->bearer = 0;
 175 }
 176
 177 /**
 178  * recv_notification - handle device updates from OS
 179  *
 180  * Change the state of the Ethernet bearer (if any) associated with the
 181  * specified device.
 182  */
 183
 184 static int recv_notification(struct notifier_block *nb, unsigned long evt,
 185                              void *dv)
 186 {
 187         struct net_device *dev = (struct net_device *)dv;
 188         struct eth_bearer *eb_ptr = &eth_bearers[0];
 189         struct eth_bearer *stop = &eth_bearers[MAX_ETH_BEARERS];
 190
 191         while ((eb_ptr->dev != dev)) {
 192                 if (++eb_ptr == stop)
 193                         return NOTIFY_DONE;     /* couldn't find device */
 194         }
 195         if (!eb_ptr->bearer)
 196                 return NOTIFY_DONE;             /* bearer had been disabled */
 197
 198         eb_ptr->bearer->mtu = dev->mtu;
 199
 200         switch (evt) {
 201         case NETDEV_CHANGE:
 202                 if (netif_carrier_ok(dev))
 203                         tipc_continue(eb_ptr->bearer);
 204                 else
 205                         tipc_block_bearer(eb_ptr->bearer->name);
 206                 break;
 207         case NETDEV_UP:
 208                 tipc_continue(eb_ptr->bearer);
 209                 break;
 210         case NETDEV_DOWN:
 211                 tipc_block_bearer(eb_ptr->bearer->name);
 212                 break;
 213         case NETDEV_CHANGEMTU:
 214         case NETDEV_CHANGEADDR:
 215                 tipc_block_bearer(eb_ptr->bearer->name);
 216                 tipc_continue(eb_ptr->bearer);
 217                 break;
 218         case NETDEV_UNREGISTER:
 219         case NETDEV_CHANGENAME:
 220                 tipc_disable_bearer(eb_ptr->bearer->name);
 221                 break;
 222         }
 223         return NOTIFY_OK;
 224 }
 225
 226 /**
 227  * eth_addr2str - convert Ethernet address to string
 228  */
 229
 230 static char *eth_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size)
 231 {
 232         unchar *addr = (unchar *)&a->dev_addr;
 233
 234         if (str_size < 18)
 235                 *str_buf = '\0';
 236         else
 237                 sprintf(str_buf, "%02x:%02x:%02x:%02x:%02x:%02x",
 238                         addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
 239         return str_buf;
 240 }
 241
 242 /**
 243  * eth_media_start - activate Ethernet bearer support
 244  *
 245  * Register Ethernet media type with TIPC bearer code.  Also register
 246  * with OS for notifications about device state changes.
 247  */
 248
 249 int eth_media_start(void)
 250 {
 251         struct tipc_media_addr bcast_addr;
 252         int res;
 253
 254         if (eth_started)
 255                 return -EINVAL;
 256
 257         memset(&bcast_addr, 0xff, sizeof(bcast_addr));
 258         memset(eth_bearers, 0, sizeof(eth_bearers));
 259
 260         res = tipc_register_media(TIPC_MEDIA_TYPE_ETH, "eth",
 261                                   enable_bearer, disable_bearer, send_msg,
 262                                   eth_addr2str, &bcast_addr, ETH_LINK_PRIORITY,
 263                                   ETH_LINK_TOLERANCE, TIPC_DEF_LINK_WIN);
 264         if (res)
 265                 return res;
 266
 267         notifier.notifier_call = &recv_notification;
 268         notifier.priority = 0;
 269         res = register_netdevice_notifier(&notifier);
 270         if (!res)
 271                 eth_started = 1;
 272         return res;
 273 }
 274
 275 /**
 276  * eth_media_stop - deactivate Ethernet bearer support
 277  */
 278
 279 void eth_media_stop(void)
 280 {
 281         int i;
 282
 283         if (!eth_started)
 284                 return;
 285
 286         unregister_netdevice_notifier(&notifier);
 287         for (i = 0; i < MAX_ETH_BEARERS ; i++) {
 288                 if (eth_bearers[i].bearer) {
 289                         eth_bearers[i].bearer->blocked = 1;
 290                         eth_bearers[i].bearer = 0;
 291                 }
 292                 if (eth_bearers[i].dev) {
 293                         dev_remove_pack(&eth_bearers[i].tipc_packet_type);
 294                         dev_put(eth_bearers[i].dev);
 295                 }
 296         }
 297         memset(&eth_bearers, 0, sizeof(eth_bearers));
 298         eth_started = 0;
 299 }