1 /* 2 * net/tipc/eth_media.c: Ethernet bearer support for TIPC 3 * 4 * Copyright (c) 2001-2007, Ericsson AB 5 * Copyright (c) 2005-2008, 2011, 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 "core.h" 38 #include "bearer.h" 39 40 #define MAX_ETH_BEARERS MAX_BEARERS 41 42 #define ETH_ADDR_OFFSET 4 /* message header offset of MAC address */ 43 44 /** 45 * struct eth_bearer - Ethernet bearer data structure 46 * @bearer: ptr to associated "generic" bearer structure 47 * @dev: ptr to associated Ethernet network device 48 * @tipc_packet_type: used in binding TIPC to Ethernet driver 49 * @cleanup: work item used when disabling bearer 50 */ 51 struct eth_bearer { 52 struct tipc_bearer *bearer; 53 struct net_device *dev; 54 struct packet_type tipc_packet_type; 55 struct work_struct cleanup; 56 }; 57 58 static struct tipc_media eth_media_info; 59 static struct eth_bearer eth_bearers[MAX_ETH_BEARERS]; 60 static int eth_started; 61 static struct notifier_block notifier; 62 63 /** 64 * eth_media_addr_set - initialize Ethernet media address structure 65 * 66 * Media-dependent "value" field stores MAC address in first 6 bytes 67 * and zeroes out the remaining bytes. 68 */ 69 static void eth_media_addr_set(struct tipc_media_addr *a, char *mac) 70 { 71 memcpy(a->value, mac, ETH_ALEN); 72 memset(a->value + ETH_ALEN, 0, sizeof(a->value) - ETH_ALEN); 73 a->media_id = TIPC_MEDIA_TYPE_ETH; 74 a->broadcast = !memcmp(mac, eth_media_info.bcast_addr.value, ETH_ALEN); 75 } 76 77 /** 78 * send_msg - send a TIPC message out over an Ethernet interface 79 */ 80 static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr, 81 struct tipc_media_addr *dest) 82 { 83 struct sk_buff *clone; 84 struct net_device *dev; 85 int delta; 86 87 clone = skb_clone(buf, GFP_ATOMIC); 88 if (!clone) 89 return 0; 90 91 dev = ((struct eth_bearer *)(tb_ptr->usr_handle))->dev; 92 delta = dev->hard_header_len - skb_headroom(buf); 93 94 if ((delta > 0) && 95 pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) { 96 kfree_skb(clone); 97 return 0; 98 } 99 100 skb_reset_network_header(clone); 101 clone->dev = dev; 102 dev_hard_header(clone, dev, ETH_P_TIPC, dest->value, 103 dev->dev_addr, clone->len); 104 dev_queue_xmit(clone); 105 return 0; 106 } 107 108 /** 109 * recv_msg - handle incoming TIPC message from an Ethernet interface 110 * 111 * Accept only packets explicitly sent to this node, or broadcast packets; 112 * ignores packets sent using Ethernet multicast, and traffic sent to other 113 * nodes (which can happen if interface is running in promiscuous mode). 114 */ 115 static int recv_msg(struct sk_buff *buf, struct net_device *dev, 116 struct packet_type *pt, struct net_device *orig_dev) 117 { 118 struct eth_bearer *eb_ptr = (struct eth_bearer *)pt->af_packet_priv; 119 120 if (!net_eq(dev_net(dev), &init_net)) { 121 kfree_skb(buf); 122 return 0; 123 } 124 125 if (likely(eb_ptr->bearer)) { 126 if (likely(buf->pkt_type <= PACKET_BROADCAST)) { 127 buf->next = NULL; 128 tipc_recv_msg(buf, eb_ptr->bearer); 129 return 0; 130 } 131 } 132 kfree_skb(buf); 133 return 0; 134 } 135 136 /** 137 * enable_bearer - attach TIPC bearer to an Ethernet interface 138 */ 139 static int enable_bearer(struct tipc_bearer *tb_ptr) 140 { 141 struct net_device *dev = NULL; 142 struct net_device *pdev = NULL; 143 struct eth_bearer *eb_ptr = ð_bearers[0]; 144 struct eth_bearer *stop = ð_bearers[MAX_ETH_BEARERS]; 145 char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1; 146 int pending_dev = 0; 147 148 /* Find unused Ethernet bearer structure */ 149 while (eb_ptr->dev) { 150 if (!eb_ptr->bearer) 151 pending_dev++; 152 if (++eb_ptr == stop) 153 return pending_dev ? -EAGAIN : -EDQUOT; 154 } 155 156 /* Find device with specified name */ 157 read_lock(&dev_base_lock); 158 for_each_netdev(&init_net, pdev) { 159 if (!strncmp(pdev->name, driver_name, IFNAMSIZ)) { 160 dev = pdev; 161 dev_hold(dev); 162 break; 163 } 164 } 165 read_unlock(&dev_base_lock); 166 if (!dev) 167 return -ENODEV; 168 169 /* Create Ethernet bearer for device */ 170 eb_ptr->dev = dev; 171 eb_ptr->tipc_packet_type.type = htons(ETH_P_TIPC); 172 eb_ptr->tipc_packet_type.dev = dev; 173 eb_ptr->tipc_packet_type.func = recv_msg; 174 eb_ptr->tipc_packet_type.af_packet_priv = eb_ptr; 175 INIT_LIST_HEAD(&(eb_ptr->tipc_packet_type.list)); 176 dev_add_pack(&eb_ptr->tipc_packet_type); 177 178 /* Associate TIPC bearer with Ethernet bearer */ 179 eb_ptr->bearer = tb_ptr; 180 tb_ptr->usr_handle = (void *)eb_ptr; 181 tb_ptr->mtu = dev->mtu; 182 tb_ptr->blocked = 0; 183 eth_media_addr_set(&tb_ptr->addr, (char *)dev->dev_addr); 184 return 0; 185 } 186 187 /** 188 * cleanup_bearer - break association between Ethernet bearer and interface 189 * 190 * This routine must be invoked from a work queue because it can sleep. 191 */ 192 static void cleanup_bearer(struct work_struct *work) 193 { 194 struct eth_bearer *eb_ptr = 195 container_of(work, struct eth_bearer, cleanup); 196 197 dev_remove_pack(&eb_ptr->tipc_packet_type); 198 dev_put(eb_ptr->dev); 199 eb_ptr->dev = NULL; 200 } 201 202 /** 203 * disable_bearer - detach TIPC bearer from an Ethernet interface 204 * 205 * Mark Ethernet bearer as inactive so that incoming buffers are thrown away, 206 * then get worker thread to complete bearer cleanup. (Can't do cleanup 207 * here because cleanup code needs to sleep and caller holds spinlocks.) 208 */ 209 static void disable_bearer(struct tipc_bearer *tb_ptr) 210 { 211 struct eth_bearer *eb_ptr = (struct eth_bearer *)tb_ptr->usr_handle; 212 213 eb_ptr->bearer = NULL; 214 INIT_WORK(&eb_ptr->cleanup, cleanup_bearer); 215 schedule_work(&eb_ptr->cleanup); 216 } 217 218 /** 219 * recv_notification - handle device updates from OS 220 * 221 * Change the state of the Ethernet bearer (if any) associated with the 222 * specified device. 223 */ 224 static int recv_notification(struct notifier_block *nb, unsigned long evt, 225 void *dv) 226 { 227 struct net_device *dev = (struct net_device *)dv; 228 struct eth_bearer *eb_ptr = ð_bearers[0]; 229 struct eth_bearer *stop = ð_bearers[MAX_ETH_BEARERS]; 230 231 if (!net_eq(dev_net(dev), &init_net)) 232 return NOTIFY_DONE; 233 234 while ((eb_ptr->dev != dev)) { 235 if (++eb_ptr == stop) 236 return NOTIFY_DONE; /* couldn't find device */ 237 } 238 if (!eb_ptr->bearer) 239 return NOTIFY_DONE; /* bearer had been disabled */ 240 241 eb_ptr->bearer->mtu = dev->mtu; 242 243 switch (evt) { 244 case NETDEV_CHANGE: 245 if (netif_carrier_ok(dev)) 246 tipc_continue(eb_ptr->bearer); 247 else 248 tipc_block_bearer(eb_ptr->bearer->name); 249 break; 250 case NETDEV_UP: 251 tipc_continue(eb_ptr->bearer); 252 break; 253 case NETDEV_DOWN: 254 tipc_block_bearer(eb_ptr->bearer->name); 255 break; 256 case NETDEV_CHANGEMTU: 257 case NETDEV_CHANGEADDR: 258 tipc_block_bearer(eb_ptr->bearer->name); 259 tipc_continue(eb_ptr->bearer); 260 break; 261 case NETDEV_UNREGISTER: 262 case NETDEV_CHANGENAME: 263 tipc_disable_bearer(eb_ptr->bearer->name); 264 break; 265 } 266 return NOTIFY_OK; 267 } 268 269 /** 270 * eth_addr2str - convert Ethernet address to string 271 */ 272 static int eth_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size) 273 { 274 if (str_size < 18) /* 18 = strlen("aa:bb:cc:dd:ee:ff\0") */ 275 return 1; 276 277 sprintf(str_buf, "%pM", a->value); 278 return 0; 279 } 280 281 /** 282 * eth_str2addr - convert string to Ethernet address 283 */ 284 static int eth_str2addr(struct tipc_media_addr *a, char *str_buf) 285 { 286 char mac[ETH_ALEN]; 287 int r; 288 289 r = sscanf(str_buf, "%02x:%02x:%02x:%02x:%02x:%02x", 290 (u32 *)&mac[0], (u32 *)&mac[1], (u32 *)&mac[2], 291 (u32 *)&mac[3], (u32 *)&mac[4], (u32 *)&mac[5]); 292 293 if (r != ETH_ALEN) 294 return 1; 295 296 eth_media_addr_set(a, mac); 297 return 0; 298 } 299 300 /** 301 * eth_str2addr - convert Ethernet address format to message header format 302 */ 303 static int eth_addr2msg(struct tipc_media_addr *a, char *msg_area) 304 { 305 memset(msg_area, 0, TIPC_MEDIA_ADDR_SIZE); 306 msg_area[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_ETH; 307 memcpy(msg_area + ETH_ADDR_OFFSET, a->value, ETH_ALEN); 308 return 0; 309 } 310 311 /** 312 * eth_str2addr - convert message header address format to Ethernet format 313 */ 314 static int eth_msg2addr(struct tipc_media_addr *a, char *msg_area) 315 { 316 if (msg_area[TIPC_MEDIA_TYPE_OFFSET] != TIPC_MEDIA_TYPE_ETH) 317 return 1; 318 319 eth_media_addr_set(a, msg_area + ETH_ADDR_OFFSET); 320 return 0; 321 } 322 323 /* 324 * Ethernet media registration info 325 */ 326 static struct tipc_media eth_media_info = { 327 .send_msg = send_msg, 328 .enable_bearer = enable_bearer, 329 .disable_bearer = disable_bearer, 330 .addr2str = eth_addr2str, 331 .str2addr = eth_str2addr, 332 .addr2msg = eth_addr2msg, 333 .msg2addr = eth_msg2addr, 334 .bcast_addr = { { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }, 335 TIPC_MEDIA_TYPE_ETH, 1 }, 336 .priority = TIPC_DEF_LINK_PRI, 337 .tolerance = TIPC_DEF_LINK_TOL, 338 .window = TIPC_DEF_LINK_WIN, 339 .type_id = TIPC_MEDIA_TYPE_ETH, 340 .name = "eth" 341 }; 342 343 /** 344 * tipc_eth_media_start - activate Ethernet bearer support 345 * 346 * Register Ethernet media type with TIPC bearer code. Also register 347 * with OS for notifications about device state changes. 348 */ 349 int tipc_eth_media_start(void) 350 { 351 int res; 352 353 if (eth_started) 354 return -EINVAL; 355 356 res = tipc_register_media(ð_media_info); 357 if (res) 358 return res; 359 360 notifier.notifier_call = &recv_notification; 361 notifier.priority = 0; 362 res = register_netdevice_notifier(¬ifier); 363 if (!res) 364 eth_started = 1; 365 return res; 366 } 367 368 /** 369 * tipc_eth_media_stop - deactivate Ethernet bearer support 370 */ 371 void tipc_eth_media_stop(void) 372 { 373 if (!eth_started) 374 return; 375 376 flush_scheduled_work(); 377 unregister_netdevice_notifier(¬ifier); 378 eth_started = 0; 379 } 380