net/tipc/eth_media.c

   1 /*
   2  * net/tipc/eth_media.c: Ethernet bearer support for TIPC
   3  *
   4  * Copyright (c) 2001-2007, Ericsson AB
   5  * Copyright (c) 2005-2007, 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  * Accept only packets explicitly sent to this node, or broadcast packets;
  91  * ignores packets sent using Ethernet multicast, and traffic sent to other
  92  * nodes (which can happen if interface is running in promiscuous mode).
  93  * Routine truncates any Ethernet padding/CRC appended to the message,
  94  * and ensures message size matches actual length
  95  */
  96
  97 static int recv_msg(struct sk_buff *buf, struct net_device *dev,
  98                     struct packet_type *pt, struct net_device *orig_dev)
  99 {
 100         struct eth_bearer *eb_ptr = (struct eth_bearer *)pt->af_packet_priv;
 101         u32 size;
 102
 103         if (likely(eb_ptr->bearer)) {
 104                 if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
 105                         size = msg_size((struct tipc_msg *)buf->data);
 106                         skb_trim(buf, size);
 107                         if (likely(buf->len == size)) {
 108                                 buf->next = NULL;
 109                                 tipc_recv_msg(buf, eb_ptr->bearer);
 110                                 return TIPC_OK;
 111                         }
 112                 }
 113         }
 114         kfree_skb(buf);
 115         return TIPC_OK;
 116 }
 117
 118 /**
 119  * enable_bearer - attach TIPC bearer to an Ethernet interface
 120  */
 121
 122 static int enable_bearer(struct tipc_bearer *tb_ptr)
 123 {
 124         struct net_device *dev = NULL;
 125         struct net_device *pdev = NULL;
 126         struct eth_bearer *eb_ptr = &eth_bearers[0];
 127         struct eth_bearer *stop = &eth_bearers[MAX_ETH_BEARERS];
 128         char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1;
 129
 130         /* Find device with specified name */
 131
 132         for_each_netdev(pdev){
 133                 if (!strncmp(pdev->name, driver_name, IFNAMSIZ)) {
 134                         dev = pdev;
 135                         break;
 136                 }
 137         }
 138         if (!dev)
 139                 return -ENODEV;
 140
 141         /* Find Ethernet bearer for device (or create one) */
 142
 143         for (;(eb_ptr != stop) && eb_ptr->dev && (eb_ptr->dev != dev); eb_ptr++);
 144         if (eb_ptr == stop)
 145                 return -EDQUOT;
 146         if (!eb_ptr->dev) {
 147                 eb_ptr->dev = dev;
 148                 eb_ptr->tipc_packet_type.type = htons(ETH_P_TIPC);
 149                 eb_ptr->tipc_packet_type.dev = dev;
 150                 eb_ptr->tipc_packet_type.func = recv_msg;
 151                 eb_ptr->tipc_packet_type.af_packet_priv = eb_ptr;
 152                 INIT_LIST_HEAD(&(eb_ptr->tipc_packet_type.list));
 153                 dev_hold(dev);
 154                 dev_add_pack(&eb_ptr->tipc_packet_type);
 155         }
 156
 157         /* Associate TIPC bearer with Ethernet bearer */
 158
 159         eb_ptr->bearer = tb_ptr;
 160         tb_ptr->usr_handle = (void *)eb_ptr;
 161         tb_ptr->mtu = dev->mtu;
 162         tb_ptr->blocked = 0;
 163         tb_ptr->addr.type = htonl(TIPC_MEDIA_TYPE_ETH);
 164         memcpy(&tb_ptr->addr.dev_addr, &dev->dev_addr, ETH_ALEN);
 165         return 0;
 166 }
 167
 168 /**
 169  * disable_bearer - detach TIPC bearer from an Ethernet interface
 170  *
 171  * We really should do dev_remove_pack() here, but this function can not be
 172  * called at tasklet level. => Use eth_bearer->bearer as a flag to throw away
 173  * incoming buffers, & postpone dev_remove_pack() to eth_media_stop() on exit.
 174  */
 175
 176 static void disable_bearer(struct tipc_bearer *tb_ptr)
 177 {
 178         ((struct eth_bearer *)tb_ptr->usr_handle)->bearer = NULL;
 179 }
 180
 181 /**
 182  * recv_notification - handle device updates from OS
 183  *
 184  * Change the state of the Ethernet bearer (if any) associated with the
 185  * specified device.
 186  */
 187
 188 static int recv_notification(struct notifier_block *nb, unsigned long evt,
 189                              void *dv)
 190 {
 191         struct net_device *dev = (struct net_device *)dv;
 192         struct eth_bearer *eb_ptr = &eth_bearers[0];
 193         struct eth_bearer *stop = &eth_bearers[MAX_ETH_BEARERS];
 194
 195         while ((eb_ptr->dev != dev)) {
 196                 if (++eb_ptr == stop)
 197                         return NOTIFY_DONE;     /* couldn't find device */
 198         }
 199         if (!eb_ptr->bearer)
 200                 return NOTIFY_DONE;             /* bearer had been disabled */
 201
 202         eb_ptr->bearer->mtu = dev->mtu;
 203
 204         switch (evt) {
 205         case NETDEV_CHANGE:
 206                 if (netif_carrier_ok(dev))
 207                         tipc_continue(eb_ptr->bearer);
 208                 else
 209                         tipc_block_bearer(eb_ptr->bearer->name);
 210                 break;
 211         case NETDEV_UP:
 212                 tipc_continue(eb_ptr->bearer);
 213                 break;
 214         case NETDEV_DOWN:
 215                 tipc_block_bearer(eb_ptr->bearer->name);
 216                 break;
 217         case NETDEV_CHANGEMTU:
 218         case NETDEV_CHANGEADDR:
 219                 tipc_block_bearer(eb_ptr->bearer->name);
 220                 tipc_continue(eb_ptr->bearer);
 221                 break;
 222         case NETDEV_UNREGISTER:
 223         case NETDEV_CHANGENAME:
 224                 tipc_disable_bearer(eb_ptr->bearer->name);
 225                 break;
 226         }
 227         return NOTIFY_OK;
 228 }
 229
 230 /**
 231  * eth_addr2str - convert Ethernet address to string
 232  */
 233
 234 static char *eth_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size)
 235 {
 236         unchar *addr = (unchar *)&a->dev_addr;
 237
 238         if (str_size < 18)
 239                 *str_buf = '\0';
 240         else
 241                 sprintf(str_buf, "%02x:%02x:%02x:%02x:%02x:%02x",
 242                         addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
 243         return str_buf;
 244 }
 245
 246 /**
 247  * tipc_eth_media_start - activate Ethernet bearer support
 248  *
 249  * Register Ethernet media type with TIPC bearer code.  Also register
 250  * with OS for notifications about device state changes.
 251  */
 252
 253 int tipc_eth_media_start(void)
 254 {
 255         struct tipc_media_addr bcast_addr;
 256         int res;
 257
 258         if (eth_started)
 259                 return -EINVAL;
 260
 261         bcast_addr.type = htonl(TIPC_MEDIA_TYPE_ETH);
 262         memset(&bcast_addr.dev_addr, 0xff, ETH_ALEN);
 263
 264         memset(eth_bearers, 0, sizeof(eth_bearers));
 265
 266         res = tipc_register_media(TIPC_MEDIA_TYPE_ETH, "eth",
 267                                   enable_bearer, disable_bearer, send_msg,
 268                                   eth_addr2str, &bcast_addr, ETH_LINK_PRIORITY,
 269                                   ETH_LINK_TOLERANCE, ETH_LINK_WINDOW);
 270         if (res)
 271                 return res;
 272
 273         notifier.notifier_call = &recv_notification;
 274         notifier.priority = 0;
 275         res = register_netdevice_notifier(&notifier);
 276         if (!res)
 277                 eth_started = 1;
 278         return res;
 279 }
 280
 281 /**
 282  * tipc_eth_media_stop - deactivate Ethernet bearer support
 283  */
 284
 285 void tipc_eth_media_stop(void)
 286 {
 287         int i;
 288
 289         if (!eth_started)
 290                 return;
 291
 292         unregister_netdevice_notifier(&notifier);
 293         for (i = 0; i < MAX_ETH_BEARERS ; i++) {
 294                 if (eth_bearers[i].bearer) {
 295                         eth_bearers[i].bearer->blocked = 1;
 296                         eth_bearers[i].bearer = NULL;
 297                 }
 298                 if (eth_bearers[i].dev) {
 299                         dev_remove_pack(&eth_bearers[i].tipc_packet_type);
 300                         dev_put(eth_bearers[i].dev);
 301                 }
 302         }
 303         memset(&eth_bearers, 0, sizeof(eth_bearers));
 304         eth_started = 0;
 305 }