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 "core.h" 38 #include "bearer.h" 39 40 #define MAX_ETH_BEARERS 2 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 for_each_netdev(&init_net, pdev) { 148 if (!strncmp(pdev->name, driver_name, IFNAMSIZ)) { 149 dev = pdev; 150 break; 151 } 152 } 153 if (!dev) 154 return -ENODEV; 155 156 /* Find Ethernet bearer for device (or create one) */ 157 158 while ((eb_ptr != stop) && eb_ptr->dev && (eb_ptr->dev != dev)) 159 eb_ptr++; 160 if (eb_ptr == stop) 161 return -EDQUOT; 162 if (!eb_ptr->dev) { 163 eb_ptr->dev = dev; 164 eb_ptr->tipc_packet_type.type = htons(ETH_P_TIPC); 165 eb_ptr->tipc_packet_type.dev = dev; 166 eb_ptr->tipc_packet_type.func = recv_msg; 167 eb_ptr->tipc_packet_type.af_packet_priv = eb_ptr; 168 INIT_LIST_HEAD(&(eb_ptr->tipc_packet_type.list)); 169 dev_hold(dev); 170 dev_add_pack(&eb_ptr->tipc_packet_type); 171 } 172 173 /* Associate TIPC bearer with Ethernet bearer */ 174 175 eb_ptr->bearer = tb_ptr; 176 tb_ptr->usr_handle = (void *)eb_ptr; 177 tb_ptr->mtu = dev->mtu; 178 tb_ptr->blocked = 0; 179 tb_ptr->addr.type = htonl(TIPC_MEDIA_TYPE_ETH); 180 memcpy(&tb_ptr->addr.dev_addr, dev->dev_addr, ETH_ALEN); 181 return 0; 182 } 183 184 /** 185 * disable_bearer - detach TIPC bearer from an Ethernet interface 186 * 187 * We really should do dev_remove_pack() here, but this function can not be 188 * called at tasklet level. => Use eth_bearer->bearer as a flag to throw away 189 * incoming buffers, & postpone dev_remove_pack() to eth_media_stop() on exit. 190 */ 191 192 static void disable_bearer(struct tipc_bearer *tb_ptr) 193 { 194 ((struct eth_bearer *)tb_ptr->usr_handle)->bearer = NULL; 195 } 196 197 /** 198 * recv_notification - handle device updates from OS 199 * 200 * Change the state of the Ethernet bearer (if any) associated with the 201 * specified device. 202 */ 203 204 static int recv_notification(struct notifier_block *nb, unsigned long evt, 205 void *dv) 206 { 207 struct net_device *dev = (struct net_device *)dv; 208 struct eth_bearer *eb_ptr = ð_bearers[0]; 209 struct eth_bearer *stop = ð_bearers[MAX_ETH_BEARERS]; 210 211 if (!net_eq(dev_net(dev), &init_net)) 212 return NOTIFY_DONE; 213 214 while ((eb_ptr->dev != dev)) { 215 if (++eb_ptr == stop) 216 return NOTIFY_DONE; /* couldn't find device */ 217 } 218 if (!eb_ptr->bearer) 219 return NOTIFY_DONE; /* bearer had been disabled */ 220 221 eb_ptr->bearer->mtu = dev->mtu; 222 223 switch (evt) { 224 case NETDEV_CHANGE: 225 if (netif_carrier_ok(dev)) 226 tipc_continue(eb_ptr->bearer); 227 else 228 tipc_block_bearer(eb_ptr->bearer->name); 229 break; 230 case NETDEV_UP: 231 tipc_continue(eb_ptr->bearer); 232 break; 233 case NETDEV_DOWN: 234 tipc_block_bearer(eb_ptr->bearer->name); 235 break; 236 case NETDEV_CHANGEMTU: 237 case NETDEV_CHANGEADDR: 238 tipc_block_bearer(eb_ptr->bearer->name); 239 tipc_continue(eb_ptr->bearer); 240 break; 241 case NETDEV_UNREGISTER: 242 case NETDEV_CHANGENAME: 243 tipc_disable_bearer(eb_ptr->bearer->name); 244 break; 245 } 246 return NOTIFY_OK; 247 } 248 249 /** 250 * eth_addr2str - convert Ethernet address to string 251 */ 252 253 static char *eth_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size) 254 { 255 unchar *addr = (unchar *)&a->dev_addr; 256 257 if (str_size < 18) 258 *str_buf = '\0'; 259 else 260 sprintf(str_buf, "%pM", addr); 261 return str_buf; 262 } 263 264 /** 265 * tipc_eth_media_start - activate Ethernet bearer support 266 * 267 * Register Ethernet media type with TIPC bearer code. Also register 268 * with OS for notifications about device state changes. 269 */ 270 271 int tipc_eth_media_start(void) 272 { 273 struct tipc_media_addr bcast_addr; 274 int res; 275 276 if (eth_started) 277 return -EINVAL; 278 279 bcast_addr.type = htonl(TIPC_MEDIA_TYPE_ETH); 280 memset(&bcast_addr.dev_addr, 0xff, ETH_ALEN); 281 282 memset(eth_bearers, 0, sizeof(eth_bearers)); 283 284 res = tipc_register_media(TIPC_MEDIA_TYPE_ETH, "eth", 285 enable_bearer, disable_bearer, send_msg, 286 eth_addr2str, &bcast_addr, ETH_LINK_PRIORITY, 287 ETH_LINK_TOLERANCE, ETH_LINK_WINDOW); 288 if (res) 289 return res; 290 291 notifier.notifier_call = &recv_notification; 292 notifier.priority = 0; 293 res = register_netdevice_notifier(¬ifier); 294 if (!res) 295 eth_started = 1; 296 return res; 297 } 298 299 /** 300 * tipc_eth_media_stop - deactivate Ethernet bearer support 301 */ 302 303 void tipc_eth_media_stop(void) 304 { 305 int i; 306 307 if (!eth_started) 308 return; 309 310 unregister_netdevice_notifier(¬ifier); 311 for (i = 0; i < MAX_ETH_BEARERS ; i++) { 312 if (eth_bearers[i].bearer) { 313 eth_bearers[i].bearer->blocked = 1; 314 eth_bearers[i].bearer = NULL; 315 } 316 if (eth_bearers[i].dev) { 317 dev_remove_pack(ð_bearers[i].tipc_packet_type); 318 dev_put(eth_bearers[i].dev); 319 } 320 } 321 memset(ð_bearers, 0, sizeof(eth_bearers)); 322 eth_started = 0; 323 } 324