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