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 #include <linux/slab.h> 42 #include <net/net_namespace.h> 43 44 #define MAX_ETH_BEARERS 2 45 #define ETH_LINK_PRIORITY TIPC_DEF_LINK_PRI 46 #define ETH_LINK_TOLERANCE TIPC_DEF_LINK_TOL 47 #define ETH_LINK_WINDOW TIPC_DEF_LINK_WIN 48 49 /** 50 * struct eth_bearer - Ethernet bearer data structure 51 * @bearer: ptr to associated "generic" bearer structure 52 * @dev: ptr to associated Ethernet network device 53 * @tipc_packet_type: used in binding TIPC to Ethernet driver 54 */ 55 56 struct eth_bearer { 57 struct tipc_bearer *bearer; 58 struct net_device *dev; 59 struct packet_type tipc_packet_type; 60 }; 61 62 static struct eth_bearer eth_bearers[MAX_ETH_BEARERS]; 63 static int eth_started = 0; 64 static struct notifier_block notifier; 65 66 /** 67 * send_msg - send a TIPC message out over an Ethernet interface 68 */ 69 70 static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr, 71 struct tipc_media_addr *dest) 72 { 73 struct sk_buff *clone; 74 struct net_device *dev; 75 int delta; 76 77 clone = skb_clone(buf, GFP_ATOMIC); 78 if (!clone) 79 return 0; 80 81 dev = ((struct eth_bearer *)(tb_ptr->usr_handle))->dev; 82 delta = dev->hard_header_len - skb_headroom(buf); 83 84 if ((delta > 0) && 85 pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) { 86 kfree_skb(clone); 87 return 0; 88 } 89 90 skb_reset_network_header(clone); 91 clone->dev = dev; 92 dev_hard_header(clone, dev, ETH_P_TIPC, &dest->dev_addr.eth_addr, 93 dev->dev_addr, clone->len); 94 dev_queue_xmit(clone); 95 return 0; 96 } 97 98 /** 99 * recv_msg - handle incoming TIPC message from an Ethernet interface 100 * 101 * Accept only packets explicitly sent to this node, or broadcast packets; 102 * ignores packets sent using Ethernet multicast, and traffic sent to other 103 * nodes (which can happen if interface is running in promiscuous mode). 104 */ 105 106 static int recv_msg(struct sk_buff *buf, struct net_device *dev, 107 struct packet_type *pt, struct net_device *orig_dev) 108 { 109 struct eth_bearer *eb_ptr = (struct eth_bearer *)pt->af_packet_priv; 110 111 if (!net_eq(dev_net(dev), &init_net)) { 112 kfree_skb(buf); 113 return 0; 114 } 115 116 if (likely(eb_ptr->bearer)) { 117 if (likely(buf->pkt_type <= PACKET_BROADCAST)) { 118 buf->next = NULL; 119 tipc_recv_msg(buf, eb_ptr->bearer); 120 return 0; 121 } 122 } 123 kfree_skb(buf); 124 return 0; 125 } 126 127 /** 128 * enable_bearer - attach TIPC bearer to an Ethernet interface 129 */ 130 131 static int enable_bearer(struct tipc_bearer *tb_ptr) 132 { 133 struct net_device *dev = NULL; 134 struct net_device *pdev = NULL; 135 struct eth_bearer *eb_ptr = ð_bearers[0]; 136 struct eth_bearer *stop = ð_bearers[MAX_ETH_BEARERS]; 137 char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1; 138 int pending_dev = 0; 139 140 /* Find unused Ethernet bearer structure */ 141 142 while (eb_ptr->dev) { 143 if (!eb_ptr->bearer) 144 pending_dev++; 145 if (++eb_ptr == stop) 146 return pending_dev ? -EAGAIN : -EDQUOT; 147 } 148 149 /* Find device with specified name */ 150 151 for_each_netdev(&init_net, pdev){ 152 if (!strncmp(pdev->name, driver_name, IFNAMSIZ)) { 153 dev = pdev; 154 break; 155 } 156 } 157 if (!dev) 158 return -ENODEV; 159 160 /* Find Ethernet bearer for device (or create one) */ 161 162 for (;(eb_ptr != stop) && eb_ptr->dev && (eb_ptr->dev != dev); eb_ptr++); 163 if (eb_ptr == stop) 164 return -EDQUOT; 165 if (!eb_ptr->dev) { 166 eb_ptr->dev = dev; 167 eb_ptr->tipc_packet_type.type = htons(ETH_P_TIPC); 168 eb_ptr->tipc_packet_type.dev = dev; 169 eb_ptr->tipc_packet_type.func = recv_msg; 170 eb_ptr->tipc_packet_type.af_packet_priv = eb_ptr; 171 INIT_LIST_HEAD(&(eb_ptr->tipc_packet_type.list)); 172 dev_hold(dev); 173 dev_add_pack(&eb_ptr->tipc_packet_type); 174 } 175 176 /* Associate TIPC bearer with Ethernet bearer */ 177 178 eb_ptr->bearer = tb_ptr; 179 tb_ptr->usr_handle = (void *)eb_ptr; 180 tb_ptr->mtu = dev->mtu; 181 tb_ptr->blocked = 0; 182 tb_ptr->addr.type = htonl(TIPC_MEDIA_TYPE_ETH); 183 memcpy(&tb_ptr->addr.dev_addr, dev->dev_addr, ETH_ALEN); 184 return 0; 185 } 186 187 /** 188 * disable_bearer - detach TIPC bearer from an Ethernet interface 189 * 190 * We really should do dev_remove_pack() here, but this function can not be 191 * called at tasklet level. => Use eth_bearer->bearer as a flag to throw away 192 * incoming buffers, & postpone dev_remove_pack() to eth_media_stop() on exit. 193 */ 194 195 static void disable_bearer(struct tipc_bearer *tb_ptr) 196 { 197 ((struct eth_bearer *)tb_ptr->usr_handle)->bearer = NULL; 198 } 199 200 /** 201 * recv_notification - handle device updates from OS 202 * 203 * Change the state of the Ethernet bearer (if any) associated with the 204 * specified device. 205 */ 206 207 static int recv_notification(struct notifier_block *nb, unsigned long evt, 208 void *dv) 209 { 210 struct net_device *dev = (struct net_device *)dv; 211 struct eth_bearer *eb_ptr = ð_bearers[0]; 212 struct eth_bearer *stop = ð_bearers[MAX_ETH_BEARERS]; 213 214 if (!net_eq(dev_net(dev), &init_net)) 215 return NOTIFY_DONE; 216 217 while ((eb_ptr->dev != dev)) { 218 if (++eb_ptr == stop) 219 return NOTIFY_DONE; /* couldn't find device */ 220 } 221 if (!eb_ptr->bearer) 222 return NOTIFY_DONE; /* bearer had been disabled */ 223 224 eb_ptr->bearer->mtu = dev->mtu; 225 226 switch (evt) { 227 case NETDEV_CHANGE: 228 if (netif_carrier_ok(dev)) 229 tipc_continue(eb_ptr->bearer); 230 else 231 tipc_block_bearer(eb_ptr->bearer->name); 232 break; 233 case NETDEV_UP: 234 tipc_continue(eb_ptr->bearer); 235 break; 236 case NETDEV_DOWN: 237 tipc_block_bearer(eb_ptr->bearer->name); 238 break; 239 case NETDEV_CHANGEMTU: 240 case NETDEV_CHANGEADDR: 241 tipc_block_bearer(eb_ptr->bearer->name); 242 tipc_continue(eb_ptr->bearer); 243 break; 244 case NETDEV_UNREGISTER: 245 case NETDEV_CHANGENAME: 246 tipc_disable_bearer(eb_ptr->bearer->name); 247 break; 248 } 249 return NOTIFY_OK; 250 } 251 252 /** 253 * eth_addr2str - convert Ethernet address to string 254 */ 255 256 static char *eth_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size) 257 { 258 unchar *addr = (unchar *)&a->dev_addr; 259 260 if (str_size < 18) 261 *str_buf = '\0'; 262 else 263 sprintf(str_buf, "%pM", addr); 264 return str_buf; 265 } 266 267 /** 268 * tipc_eth_media_start - activate Ethernet bearer support 269 * 270 * Register Ethernet media type with TIPC bearer code. Also register 271 * with OS for notifications about device state changes. 272 */ 273 274 int tipc_eth_media_start(void) 275 { 276 struct tipc_media_addr bcast_addr; 277 int res; 278 279 if (eth_started) 280 return -EINVAL; 281 282 bcast_addr.type = htonl(TIPC_MEDIA_TYPE_ETH); 283 memset(&bcast_addr.dev_addr, 0xff, ETH_ALEN); 284 285 memset(eth_bearers, 0, sizeof(eth_bearers)); 286 287 res = tipc_register_media(TIPC_MEDIA_TYPE_ETH, "eth", 288 enable_bearer, disable_bearer, send_msg, 289 eth_addr2str, &bcast_addr, ETH_LINK_PRIORITY, 290 ETH_LINK_TOLERANCE, ETH_LINK_WINDOW); 291 if (res) 292 return res; 293 294 notifier.notifier_call = &recv_notification; 295 notifier.priority = 0; 296 res = register_netdevice_notifier(¬ifier); 297 if (!res) 298 eth_started = 1; 299 return res; 300 } 301 302 /** 303 * tipc_eth_media_stop - deactivate Ethernet bearer support 304 */ 305 306 void tipc_eth_media_stop(void) 307 { 308 int i; 309 310 if (!eth_started) 311 return; 312 313 unregister_netdevice_notifier(¬ifier); 314 for (i = 0; i < MAX_ETH_BEARERS ; i++) { 315 if (eth_bearers[i].bearer) { 316 eth_bearers[i].bearer->blocked = 1; 317 eth_bearers[i].bearer = NULL; 318 } 319 if (eth_bearers[i].dev) { 320 dev_remove_pack(ð_bearers[i].tipc_packet_type); 321 dev_put(eth_bearers[i].dev); 322 } 323 } 324 memset(ð_bearers, 0, sizeof(eth_bearers)); 325 eth_started = 0; 326 } 327