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 = ð_bearers[0]; 127 struct eth_bearer *stop = ð_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 = ð_bearers[0]; 193 struct eth_bearer *stop = ð_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(¬ifier); 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(¬ifier); 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(ð_bearers[i].tipc_packet_type); 300 dev_put(eth_bearers[i].dev); 301 } 302 } 303 memset(ð_bearers, 0, sizeof(eth_bearers)); 304 eth_started = 0; 305 } 306