net/tipc/eth_media.c

   1 /*
   2  * net/tipc/eth_media.c: Ethernet bearer support for TIPC
   3  *
   4  * Copyright (c) 2003-2005, Ericsson Research Canada
   5  * Copyright (c) 2005, Wind River Systems
   6  * Copyright (c) 2005-2006, Ericsson AB
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the names of the copyright holders nor the names of its
  18  *    contributors may be used to endorse or promote products derived from
  19  *    this software without specific prior written permission.
  20  *
  21  * Alternatively, this software may be distributed under the terms of the
  22  * GNU General Public License ("GPL") version 2 as published by the Free
  23  * Software Foundation.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  26  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  28  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  29  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  35  * POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 #include <net/tipc/tipc.h>
  39 #include <net/tipc/tipc_bearer.h>
  40 #include <net/tipc/tipc_msg.h>
  41 #include <linux/netdevice.h>
  42 #include <linux/version.h>
  43
  44 #define MAX_ETH_BEARERS         2
  45 #define TIPC_PROTOCOL           0x88ca
  46 #define ETH_LINK_PRIORITY       10
  47 #define ETH_LINK_TOLERANCE      TIPC_DEF_LINK_TOL
  48
  49
  50 /**
  51  * struct eth_bearer - Ethernet bearer data structure
  52  * @bearer: ptr to associated "generic" bearer structure
  53  * @dev: ptr to associated Ethernet network device
  54  * @tipc_packet_type: used in binding TIPC to Ethernet driver
  55  */
  56
  57 struct eth_bearer {
  58         struct tipc_bearer *bearer;
  59         struct net_device *dev;
  60         struct packet_type tipc_packet_type;
  61 };
  62
  63 static struct eth_bearer eth_bearers[MAX_ETH_BEARERS];
  64 static int eth_started = 0;
  65 static struct notifier_block notifier;
  66
  67 /**
  68  * send_msg - send a TIPC message out over an Ethernet interface
  69  */
  70
  71 static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr,
  72                     struct tipc_media_addr *dest)
  73 {
  74         struct sk_buff *clone;
  75         struct net_device *dev;
  76
  77         clone = skb_clone(buf, GFP_ATOMIC);
  78         if (clone) {
  79                 clone->nh.raw = clone->data;
  80                 dev = ((struct eth_bearer *)(tb_ptr->usr_handle))->dev;
  81                 clone->dev = dev;
  82                 dev->hard_header(clone, dev, TIPC_PROTOCOL,
  83                                  &dest->dev_addr.eth_addr,
  84                                  dev->dev_addr, clone->len);
  85                 dev_queue_xmit(clone);
  86         }
  87         return TIPC_OK;
  88 }
  89
  90 /**
  91  * recv_msg - handle incoming TIPC message from an Ethernet interface
  92  *
  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                 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                 } else {
 110                         kfree_skb(buf);
 111                 }
 112         } else {
 113                 kfree_skb(buf);
 114         }
 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 = dev_base;
 125         struct eth_bearer *eb_ptr = &eth_bearers[0];
 126         struct eth_bearer *stop = &eth_bearers[MAX_ETH_BEARERS];
 127         char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1;
 128
 129         /* Find device with specified name */
 130
 131         while (dev && dev->name &&
 132                (memcmp(dev->name, driver_name, strlen(dev->name)))) {
 133                 dev = dev->next;
 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 = __constant_htons(TIPC_PROTOCOL);
 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 = 0;
 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  * 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 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         memset(&bcast_addr, 0xff, sizeof(bcast_addr));
 259         memset(eth_bearers, 0, sizeof(eth_bearers));
 260
 261         res = tipc_register_media(TIPC_MEDIA_TYPE_ETH, "eth",
 262                                   enable_bearer, disable_bearer, send_msg,
 263                                   eth_addr2str, &bcast_addr, ETH_LINK_PRIORITY,
 264                                   ETH_LINK_TOLERANCE, TIPC_DEF_LINK_WIN);
 265         if (res)
 266                 return res;
 267
 268         notifier.notifier_call = &recv_notification;
 269         notifier.priority = 0;
 270         res = register_netdevice_notifier(&notifier);
 271         if (!res)
 272                 eth_started = 1;
 273         return res;
 274 }
 275
 276 /**
 277  * eth_media_stop - deactivate Ethernet bearer support
 278  */
 279
 280 void eth_media_stop(void)
 281 {
 282         int i;
 283
 284         if (!eth_started)
 285                 return;
 286
 287         unregister_netdevice_notifier(&notifier);
 288         for (i = 0; i < MAX_ETH_BEARERS ; i++) {
 289                 if (eth_bearers[i].bearer) {
 290                         eth_bearers[i].bearer->blocked = 1;
 291                         eth_bearers[i].bearer = 0;
 292                 }
 293                 if (eth_bearers[i].dev) {
 294                         dev_remove_pack(&eth_bearers[i].tipc_packet_type);
 295                         dev_put(eth_bearers[i].dev);
 296                 }
 297         }
 298         memset(&eth_bearers, 0, sizeof(eth_bearers));
 299         eth_started = 0;
 300 }