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 #define ETH_LINK_PRIORITY TIPC_DEF_LINK_PRI 42 #define ETH_LINK_TOLERANCE TIPC_DEF_LINK_TOL 43 #define ETH_LINK_WINDOW TIPC_DEF_LINK_WIN 44 45 /** 46 * struct eth_bearer - Ethernet bearer data structure 47 * @bearer: ptr to associated "generic" bearer structure 48 * @dev: ptr to associated Ethernet network device 49 * @tipc_packet_type: used in binding TIPC to Ethernet driver 50 */ 51 52 struct eth_bearer { 53 struct tipc_bearer *bearer; 54 struct net_device *dev; 55 struct packet_type tipc_packet_type; 56 }; 57 58 static struct eth_bearer eth_bearers[MAX_ETH_BEARERS]; 59 static int eth_started; 60 static struct notifier_block notifier; 61 62 /** 63 * send_msg - send a TIPC message out over an Ethernet interface 64 */ 65 66 static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr, 67 struct tipc_media_addr *dest) 68 { 69 struct sk_buff *clone; 70 struct net_device *dev; 71 int delta; 72 73 clone = skb_clone(buf, GFP_ATOMIC); 74 if (!clone) 75 return 0; 76 77 dev = ((struct eth_bearer *)(tb_ptr->usr_handle))->dev; 78 delta = dev->hard_header_len - skb_headroom(buf); 79 80 if ((delta > 0) && 81 pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) { 82 kfree_skb(clone); 83 return 0; 84 } 85 86 skb_reset_network_header(clone); 87 clone->dev = dev; 88 dev_hard_header(clone, dev, ETH_P_TIPC, &dest->dev_addr.eth_addr, 89 dev->dev_addr, clone->len); 90 dev_queue_xmit(clone); 91 return 0; 92 } 93 94 /** 95 * recv_msg - handle incoming TIPC message from an Ethernet interface 96 * 97 * Accept only packets explicitly sent to this node, or broadcast packets; 98 * ignores packets sent using Ethernet multicast, and traffic sent to other 99 * nodes (which can happen if interface is running in promiscuous mode). 100 */ 101 102 static int recv_msg(struct sk_buff *buf, struct net_device *dev, 103 struct packet_type *pt, struct net_device *orig_dev) 104 { 105 struct eth_bearer *eb_ptr = (struct eth_bearer *)pt->af_packet_priv; 106 107 if (!net_eq(dev_net(dev), &init_net)) { 108 kfree_skb(buf); 109 return 0; 110 } 111 112 if (likely(eb_ptr->bearer)) { 113 if (likely(buf->pkt_type <= PACKET_BROADCAST)) { 114 buf->next = NULL; 115 tipc_recv_msg(buf, eb_ptr->bearer); 116 return 0; 117 } 118 } 119 kfree_skb(buf); 120 return 0; 121 } 122 123 /** 124 * enable_bearer - attach TIPC bearer to an Ethernet interface 125 */ 126 127 static int enable_bearer(struct tipc_bearer *tb_ptr) 128 { 129 struct net_device *dev = NULL; 130 struct net_device *pdev = NULL; 131 struct eth_bearer *eb_ptr = ð_bearers[0]; 132 struct eth_bearer *stop = ð_bearers[MAX_ETH_BEARERS]; 133 char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1; 134 int pending_dev = 0; 135 136 /* Find unused Ethernet bearer structure */ 137 138 while (eb_ptr->dev) { 139 if (!eb_ptr->bearer) 140 pending_dev++; 141 if (++eb_ptr == stop) 142 return pending_dev ? -EAGAIN : -EDQUOT; 143 } 144 145 /* Find device with specified name */ 146 147 read_lock(&dev_base_lock); 148 for_each_netdev(&init_net, pdev) { 149 if (!strncmp(pdev->name, driver_name, IFNAMSIZ)) { 150 dev = pdev; 151 dev_hold(dev); 152 break; 153 } 154 } 155 read_unlock(&dev_base_lock); 156 if (!dev) 157 return -ENODEV; 158 159 /* Create Ethernet bearer for device */ 160 161 eb_ptr->dev = dev; 162 eb_ptr->tipc_packet_type.type = htons(ETH_P_TIPC); 163 eb_ptr->tipc_packet_type.dev = dev; 164 eb_ptr->tipc_packet_type.func = recv_msg; 165 eb_ptr->tipc_packet_type.af_packet_priv = eb_ptr; 166 INIT_LIST_HEAD(&(eb_ptr->tipc_packet_type.list)); 167 dev_add_pack(&eb_ptr->tipc_packet_type); 168 169 /* Associate TIPC bearer with Ethernet bearer */ 170 171 eb_ptr->bearer = tb_ptr; 172 tb_ptr->usr_handle = (void *)eb_ptr; 173 tb_ptr->mtu = dev->mtu; 174 tb_ptr->blocked = 0; 175 tb_ptr->addr.type = htonl(TIPC_MEDIA_TYPE_ETH); 176 memcpy(&tb_ptr->addr.dev_addr, dev->dev_addr, ETH_ALEN); 177 return 0; 178 } 179 180 /** 181 * disable_bearer - detach TIPC bearer from an Ethernet interface 182 * 183 * We really should do dev_remove_pack() here, but this function can not be 184 * called at tasklet level. => Use eth_bearer->bearer as a flag to throw away 185 * incoming buffers, & postpone dev_remove_pack() to eth_media_stop() on exit. 186 */ 187 188 static void disable_bearer(struct tipc_bearer *tb_ptr) 189 { 190 ((struct eth_bearer *)tb_ptr->usr_handle)->bearer = NULL; 191 } 192 193 /** 194 * recv_notification - handle device updates from OS 195 * 196 * Change the state of the Ethernet bearer (if any) associated with the 197 * specified device. 198 */ 199 200 static int recv_notification(struct notifier_block *nb, unsigned long evt, 201 void *dv) 202 { 203 struct net_device *dev = (struct net_device *)dv; 204 struct eth_bearer *eb_ptr = ð_bearers[0]; 205 struct eth_bearer *stop = ð_bearers[MAX_ETH_BEARERS]; 206 207 if (!net_eq(dev_net(dev), &init_net)) 208 return NOTIFY_DONE; 209 210 while ((eb_ptr->dev != dev)) { 211 if (++eb_ptr == stop) 212 return NOTIFY_DONE; /* couldn't find device */ 213 } 214 if (!eb_ptr->bearer) 215 return NOTIFY_DONE; /* bearer had been disabled */ 216 217 eb_ptr->bearer->mtu = dev->mtu; 218 219 switch (evt) { 220 case NETDEV_CHANGE: 221 if (netif_carrier_ok(dev)) 222 tipc_continue(eb_ptr->bearer); 223 else 224 tipc_block_bearer(eb_ptr->bearer->name); 225 break; 226 case NETDEV_UP: 227 tipc_continue(eb_ptr->bearer); 228 break; 229 case NETDEV_DOWN: 230 tipc_block_bearer(eb_ptr->bearer->name); 231 break; 232 case NETDEV_CHANGEMTU: 233 case NETDEV_CHANGEADDR: 234 tipc_block_bearer(eb_ptr->bearer->name); 235 tipc_continue(eb_ptr->bearer); 236 break; 237 case NETDEV_UNREGISTER: 238 case NETDEV_CHANGENAME: 239 tipc_disable_bearer(eb_ptr->bearer->name); 240 break; 241 } 242 return NOTIFY_OK; 243 } 244 245 /** 246 * eth_addr2str - convert Ethernet address to string 247 */ 248 249 static char *eth_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size) 250 { 251 unchar *addr = (unchar *)&a->dev_addr; 252 253 if (str_size < 18) 254 *str_buf = '\0'; 255 else 256 sprintf(str_buf, "%pM", addr); 257 return str_buf; 258 } 259 260 /** 261 * tipc_eth_media_start - activate Ethernet bearer support 262 * 263 * Register Ethernet media type with TIPC bearer code. Also register 264 * with OS for notifications about device state changes. 265 */ 266 267 int tipc_eth_media_start(void) 268 { 269 struct tipc_media_addr bcast_addr; 270 int res; 271 272 if (eth_started) 273 return -EINVAL; 274 275 bcast_addr.type = htonl(TIPC_MEDIA_TYPE_ETH); 276 memset(&bcast_addr.dev_addr, 0xff, ETH_ALEN); 277 278 memset(eth_bearers, 0, sizeof(eth_bearers)); 279 280 res = tipc_register_media(TIPC_MEDIA_TYPE_ETH, "eth", 281 enable_bearer, disable_bearer, send_msg, 282 eth_addr2str, &bcast_addr, ETH_LINK_PRIORITY, 283 ETH_LINK_TOLERANCE, ETH_LINK_WINDOW); 284 if (res) 285 return res; 286 287 notifier.notifier_call = &recv_notification; 288 notifier.priority = 0; 289 res = register_netdevice_notifier(¬ifier); 290 if (!res) 291 eth_started = 1; 292 return res; 293 } 294 295 /** 296 * tipc_eth_media_stop - deactivate Ethernet bearer support 297 */ 298 299 void tipc_eth_media_stop(void) 300 { 301 int i; 302 303 if (!eth_started) 304 return; 305 306 unregister_netdevice_notifier(¬ifier); 307 for (i = 0; i < MAX_ETH_BEARERS ; i++) { 308 if (eth_bearers[i].bearer) { 309 eth_bearers[i].bearer->blocked = 1; 310 eth_bearers[i].bearer = NULL; 311 } 312 if (eth_bearers[i].dev) { 313 dev_remove_pack(ð_bearers[i].tipc_packet_type); 314 dev_put(eth_bearers[i].dev); 315 } 316 } 317 memset(ð_bearers, 0, sizeof(eth_bearers)); 318 eth_started = 0; 319 } 320