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) 2005-2006, 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
  42 #define MAX_ETH_BEARERS         2
  43 #define ETH_LINK_PRIORITY       TIPC_DEF_LINK_PRI
  44 #define ETH_LINK_TOLERANCE      TIPC_DEF_LINK_TOL
  45 #define ETH_LINK_WINDOW         TIPC_DEF_LINK_WIN
  46
  47 /**
  48  * struct eth_bearer - Ethernet bearer data structure
  49  * @bearer: ptr to associated "generic" bearer structure
  50  * @dev: ptr to associated Ethernet network device
  51  * @tipc_packet_type: used in binding TIPC to Ethernet driver
  52  */
  53
  54 struct eth_bearer {
  55         struct tipc_bearer *bearer;
  56         struct net_device *dev;
  57         struct packet_type tipc_packet_type;
  58 };
  59
  60 static struct eth_bearer eth_bearers[MAX_ETH_BEARERS];
  61 static int eth_started = 0;
  62 static struct notifier_block notifier;
  63
  64 /**
  65  * send_msg - send a TIPC message out over an Ethernet interface
  66  */
  67
  68 static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr,
  69                     struct tipc_media_addr *dest)
  70 {
  71         struct sk_buff *clone;
  72         struct net_device *dev;
  73
  74         clone = skb_clone(buf, GFP_ATOMIC);
  75         if (clone) {
  76                 skb_reset_network_header(clone);
  77                 dev = ((struct eth_bearer *)(tb_ptr->usr_handle))->dev;
  78                 clone->dev = dev;
  79                 dev->hard_header(clone, dev, ETH_P_TIPC,
  80                                  &dest->dev_addr.eth_addr,
  81                                  dev->dev_addr, clone->len);
  82                 dev_queue_xmit(clone);
  83         }
  84         return TIPC_OK;
  85 }
  86
  87 /**
  88  * recv_msg - handle incoming TIPC message from an Ethernet interface
  89  *
  90  * Routine truncates any Ethernet padding/CRC appended to the message,
  91  * and ensures message size matches actual length
  92  */
  93
  94 static int recv_msg(struct sk_buff *buf, struct net_device *dev,
  95                     struct packet_type *pt, struct net_device *orig_dev)
  96 {
  97         struct eth_bearer *eb_ptr = (struct eth_bearer *)pt->af_packet_priv;
  98         u32 size;
  99
 100         if (likely(eb_ptr->bearer)) {
 101                if (likely(!dev->promiscuity) ||
 102                    !memcmp(skb_mac_header(buf), dev->dev_addr, ETH_ALEN) ||
 103                    !memcmp(skb_mac_header(buf), dev->broadcast, ETH_ALEN)) {
 104                         size = msg_size((struct tipc_msg *)buf->data);
 105                         skb_trim(buf, size);
 106                         if (likely(buf->len == size)) {
 107                                 buf->next = NULL;
 108                                 tipc_recv_msg(buf, eb_ptr->bearer);
 109                                 return TIPC_OK;
 110                         }
 111                 }
 112         }
 113         kfree_skb(buf);
 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, *pdev;
 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         dev = NULL;
 130         for_each_netdev(pdev)
 131                 if (!strncmp(dev->name, driver_name, IFNAMSIZ)) {
 132                         dev = pdev;
 133                         break;
 134                 }
 135         if (!dev)
 136                 return -ENODEV;
 137
 138         /* Find Ethernet bearer for device (or create one) */
 139
 140         for (;(eb_ptr != stop) && eb_ptr->dev && (eb_ptr->dev != dev); eb_ptr++);
 141         if (eb_ptr == stop)
 142                 return -EDQUOT;
 143         if (!eb_ptr->dev) {
 144                 eb_ptr->dev = dev;
 145                 eb_ptr->tipc_packet_type.type = htons(ETH_P_TIPC);
 146                 eb_ptr->tipc_packet_type.dev = dev;
 147                 eb_ptr->tipc_packet_type.func = recv_msg;
 148                 eb_ptr->tipc_packet_type.af_packet_priv = eb_ptr;
 149                 INIT_LIST_HEAD(&(eb_ptr->tipc_packet_type.list));
 150                 dev_hold(dev);
 151                 dev_add_pack(&eb_ptr->tipc_packet_type);
 152         }
 153
 154         /* Associate TIPC bearer with Ethernet bearer */
 155
 156         eb_ptr->bearer = tb_ptr;
 157         tb_ptr->usr_handle = (void *)eb_ptr;
 158         tb_ptr->mtu = dev->mtu;
 159         tb_ptr->blocked = 0;
 160         tb_ptr->addr.type = htonl(TIPC_MEDIA_TYPE_ETH);
 161         memcpy(&tb_ptr->addr.dev_addr, &dev->dev_addr, ETH_ALEN);
 162         return 0;
 163 }
 164
 165 /**
 166  * disable_bearer - detach TIPC bearer from an Ethernet interface
 167  *
 168  * We really should do dev_remove_pack() here, but this function can not be
 169  * called at tasklet level. => Use eth_bearer->bearer as a flag to throw away
 170  * incoming buffers, & postpone dev_remove_pack() to eth_media_stop() on exit.
 171  */
 172
 173 static void disable_bearer(struct tipc_bearer *tb_ptr)
 174 {
 175         ((struct eth_bearer *)tb_ptr->usr_handle)->bearer = NULL;
 176 }
 177
 178 /**
 179  * recv_notification - handle device updates from OS
 180  *
 181  * Change the state of the Ethernet bearer (if any) associated with the
 182  * specified device.
 183  */
 184
 185 static int recv_notification(struct notifier_block *nb, unsigned long evt,
 186                              void *dv)
 187 {
 188         struct net_device *dev = (struct net_device *)dv;
 189         struct eth_bearer *eb_ptr = &eth_bearers[0];
 190         struct eth_bearer *stop = &eth_bearers[MAX_ETH_BEARERS];
 191
 192         while ((eb_ptr->dev != dev)) {
 193                 if (++eb_ptr == stop)
 194                         return NOTIFY_DONE;     /* couldn't find device */
 195         }
 196         if (!eb_ptr->bearer)
 197                 return NOTIFY_DONE;             /* bearer had been disabled */
 198
 199         eb_ptr->bearer->mtu = dev->mtu;
 200
 201         switch (evt) {
 202         case NETDEV_CHANGE:
 203                 if (netif_carrier_ok(dev))
 204                         tipc_continue(eb_ptr->bearer);
 205                 else
 206                         tipc_block_bearer(eb_ptr->bearer->name);
 207                 break;
 208         case NETDEV_UP:
 209                 tipc_continue(eb_ptr->bearer);
 210                 break;
 211         case NETDEV_DOWN:
 212                 tipc_block_bearer(eb_ptr->bearer->name);
 213                 break;
 214         case NETDEV_CHANGEMTU:
 215         case NETDEV_CHANGEADDR:
 216                 tipc_block_bearer(eb_ptr->bearer->name);
 217                 tipc_continue(eb_ptr->bearer);
 218                 break;
 219         case NETDEV_UNREGISTER:
 220         case NETDEV_CHANGENAME:
 221                 tipc_disable_bearer(eb_ptr->bearer->name);
 222                 break;
 223         }
 224         return NOTIFY_OK;
 225 }
 226
 227 /**
 228  * eth_addr2str - convert Ethernet address to string
 229  */
 230
 231 static char *eth_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size)
 232 {
 233         unchar *addr = (unchar *)&a->dev_addr;
 234
 235         if (str_size < 18)
 236                 *str_buf = '\0';
 237         else
 238                 sprintf(str_buf, "%02x:%02x:%02x:%02x:%02x:%02x",
 239                         addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
 240         return str_buf;
 241 }
 242
 243 /**
 244  * tipc_eth_media_start - activate Ethernet bearer support
 245  *
 246  * Register Ethernet media type with TIPC bearer code.  Also register
 247  * with OS for notifications about device state changes.
 248  */
 249
 250 int tipc_eth_media_start(void)
 251 {
 252         struct tipc_media_addr bcast_addr;
 253         int res;
 254
 255         if (eth_started)
 256                 return -EINVAL;
 257
 258         bcast_addr.type = htonl(TIPC_MEDIA_TYPE_ETH);
 259         memset(&bcast_addr.dev_addr, 0xff, ETH_ALEN);
 260
 261         memset(eth_bearers, 0, sizeof(eth_bearers));
 262
 263         res = tipc_register_media(TIPC_MEDIA_TYPE_ETH, "eth",
 264                                   enable_bearer, disable_bearer, send_msg,
 265                                   eth_addr2str, &bcast_addr, ETH_LINK_PRIORITY,
 266                                   ETH_LINK_TOLERANCE, ETH_LINK_WINDOW);
 267         if (res)
 268                 return res;
 269
 270         notifier.notifier_call = &recv_notification;
 271         notifier.priority = 0;
 272         res = register_netdevice_notifier(&notifier);
 273         if (!res)
 274                 eth_started = 1;
 275         return res;
 276 }
 277
 278 /**
 279  * tipc_eth_media_stop - deactivate Ethernet bearer support
 280  */
 281
 282 void tipc_eth_media_stop(void)
 283 {
 284         int i;
 285
 286         if (!eth_started)
 287                 return;
 288
 289         unregister_netdevice_notifier(&notifier);
 290         for (i = 0; i < MAX_ETH_BEARERS ; i++) {
 291                 if (eth_bearers[i].bearer) {
 292                         eth_bearers[i].bearer->blocked = 1;
 293                         eth_bearers[i].bearer = NULL;
 294                 }
 295                 if (eth_bearers[i].dev) {
 296                         dev_remove_pack(&eth_bearers[i].tipc_packet_type);
 297                         dev_put(eth_bearers[i].dev);
 298                 }
 299         }
 300         memset(&eth_bearers, 0, sizeof(eth_bearers));
 301         eth_started = 0;
 302 }