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 <net/net_namespace.h> 42 43 #define MAX_ETH_BEARERS 2 44 #define ETH_LINK_PRIORITY TIPC_DEF_LINK_PRI 45 #define ETH_LINK_TOLERANCE TIPC_DEF_LINK_TOL 46 #define ETH_LINK_WINDOW TIPC_DEF_LINK_WIN 47 48 /** 49 * struct eth_bearer - Ethernet bearer data structure 50 * @bearer: ptr to associated "generic" bearer structure 51 * @dev: ptr to associated Ethernet network device 52 * @tipc_packet_type: used in binding TIPC to Ethernet driver 53 */ 54 55 struct eth_bearer { 56 struct tipc_bearer *bearer; 57 struct net_device *dev; 58 struct packet_type tipc_packet_type; 59 }; 60 61 static struct eth_bearer eth_bearers[MAX_ETH_BEARERS]; 62 static int eth_started = 0; 63 static struct notifier_block notifier; 64 65 /** 66 * send_msg - send a TIPC message out over an Ethernet interface 67 */ 68 69 static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr, 70 struct tipc_media_addr *dest) 71 { 72 struct sk_buff *clone; 73 struct net_device *dev; 74 75 clone = skb_clone(buf, GFP_ATOMIC); 76 if (clone) { 77 skb_reset_network_header(clone); 78 dev = ((struct eth_bearer *)(tb_ptr->usr_handle))->dev; 79 clone->dev = dev; 80 dev_hard_header(clone, dev, ETH_P_TIPC, 81 &dest->dev_addr.eth_addr, 82 dev->dev_addr, clone->len); 83 dev_queue_xmit(clone); 84 } 85 return 0; 86 } 87 88 /** 89 * recv_msg - handle incoming TIPC message from an Ethernet interface 90 * 91 * Accept only packets explicitly sent to this node, or broadcast packets; 92 * ignores packets sent using Ethernet multicast, and traffic sent to other 93 * nodes (which can happen if interface is running in promiscuous mode). 94 * Routine truncates any Ethernet padding/CRC appended to the message, 95 * and ensures message size matches actual length 96 */ 97 98 static int recv_msg(struct sk_buff *buf, struct net_device *dev, 99 struct packet_type *pt, struct net_device *orig_dev) 100 { 101 struct eth_bearer *eb_ptr = (struct eth_bearer *)pt->af_packet_priv; 102 u32 size; 103 104 if (!net_eq(dev_net(dev), &init_net)) { 105 kfree_skb(buf); 106 return 0; 107 } 108 109 if (likely(eb_ptr->bearer)) { 110 if (likely(buf->pkt_type <= PACKET_BROADCAST)) { 111 size = msg_size((struct tipc_msg *)buf->data); 112 skb_trim(buf, size); 113 if (likely(buf->len == size)) { 114 buf->next = NULL; 115 tipc_recv_msg(buf, eb_ptr->bearer); 116 return 0; 117 } 118 } 119 } 120 kfree_skb(buf); 121 return 0; 122 } 123 124 /** 125 * enable_bearer - attach TIPC bearer to an Ethernet interface 126 */ 127 128 static int enable_bearer(struct tipc_bearer *tb_ptr) 129 { 130 struct net_device *dev = NULL; 131 struct net_device *pdev = NULL; 132 struct eth_bearer *eb_ptr = ð_bearers[0]; 133 struct eth_bearer *stop = ð_bearers[MAX_ETH_BEARERS]; 134 char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1; 135 136 /* Find device with specified name */ 137 138 for_each_netdev(&init_net, pdev){ 139 if (!strncmp(pdev->name, driver_name, IFNAMSIZ)) { 140 dev = pdev; 141 break; 142 } 143 } 144 if (!dev) 145 return -ENODEV; 146 147 /* Find Ethernet bearer for device (or create one) */ 148 149 for (;(eb_ptr != stop) && eb_ptr->dev && (eb_ptr->dev != dev); eb_ptr++); 150 if (eb_ptr == stop) 151 return -EDQUOT; 152 if (!eb_ptr->dev) { 153 eb_ptr->dev = dev; 154 eb_ptr->tipc_packet_type.type = htons(ETH_P_TIPC); 155 eb_ptr->tipc_packet_type.dev = dev; 156 eb_ptr->tipc_packet_type.func = recv_msg; 157 eb_ptr->tipc_packet_type.af_packet_priv = eb_ptr; 158 INIT_LIST_HEAD(&(eb_ptr->tipc_packet_type.list)); 159 dev_hold(dev); 160 dev_add_pack(&eb_ptr->tipc_packet_type); 161 } 162 163 /* Associate TIPC bearer with Ethernet bearer */ 164 165 eb_ptr->bearer = tb_ptr; 166 tb_ptr->usr_handle = (void *)eb_ptr; 167 tb_ptr->mtu = dev->mtu; 168 tb_ptr->blocked = 0; 169 tb_ptr->addr.type = htonl(TIPC_MEDIA_TYPE_ETH); 170 memcpy(&tb_ptr->addr.dev_addr, dev->dev_addr, ETH_ALEN); 171 return 0; 172 } 173 174 /** 175 * disable_bearer - detach TIPC bearer from an Ethernet interface 176 * 177 * We really should do dev_remove_pack() here, but this function can not be 178 * called at tasklet level. => Use eth_bearer->bearer as a flag to throw away 179 * incoming buffers, & postpone dev_remove_pack() to eth_media_stop() on exit. 180 */ 181 182 static void disable_bearer(struct tipc_bearer *tb_ptr) 183 { 184 ((struct eth_bearer *)tb_ptr->usr_handle)->bearer = NULL; 185 } 186 187 /** 188 * recv_notification - handle device updates from OS 189 * 190 * Change the state of the Ethernet bearer (if any) associated with the 191 * specified device. 192 */ 193 194 static int recv_notification(struct notifier_block *nb, unsigned long evt, 195 void *dv) 196 { 197 struct net_device *dev = (struct net_device *)dv; 198 struct eth_bearer *eb_ptr = ð_bearers[0]; 199 struct eth_bearer *stop = ð_bearers[MAX_ETH_BEARERS]; 200 201 if (!net_eq(dev_net(dev), &init_net)) 202 return NOTIFY_DONE; 203 204 while ((eb_ptr->dev != dev)) { 205 if (++eb_ptr == stop) 206 return NOTIFY_DONE; /* couldn't find device */ 207 } 208 if (!eb_ptr->bearer) 209 return NOTIFY_DONE; /* bearer had been disabled */ 210 211 eb_ptr->bearer->mtu = dev->mtu; 212 213 switch (evt) { 214 case NETDEV_CHANGE: 215 if (netif_carrier_ok(dev)) 216 tipc_continue(eb_ptr->bearer); 217 else 218 tipc_block_bearer(eb_ptr->bearer->name); 219 break; 220 case NETDEV_UP: 221 tipc_continue(eb_ptr->bearer); 222 break; 223 case NETDEV_DOWN: 224 tipc_block_bearer(eb_ptr->bearer->name); 225 break; 226 case NETDEV_CHANGEMTU: 227 case NETDEV_CHANGEADDR: 228 tipc_block_bearer(eb_ptr->bearer->name); 229 tipc_continue(eb_ptr->bearer); 230 break; 231 case NETDEV_UNREGISTER: 232 case NETDEV_CHANGENAME: 233 tipc_disable_bearer(eb_ptr->bearer->name); 234 break; 235 } 236 return NOTIFY_OK; 237 } 238 239 /** 240 * eth_addr2str - convert Ethernet address to string 241 */ 242 243 static char *eth_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size) 244 { 245 unchar *addr = (unchar *)&a->dev_addr; 246 247 if (str_size < 18) 248 *str_buf = '\0'; 249 else 250 sprintf(str_buf, "%pM", addr); 251 return str_buf; 252 } 253 254 /** 255 * tipc_eth_media_start - activate Ethernet bearer support 256 * 257 * Register Ethernet media type with TIPC bearer code. Also register 258 * with OS for notifications about device state changes. 259 */ 260 261 int tipc_eth_media_start(void) 262 { 263 struct tipc_media_addr bcast_addr; 264 int res; 265 266 if (eth_started) 267 return -EINVAL; 268 269 bcast_addr.type = htonl(TIPC_MEDIA_TYPE_ETH); 270 memset(&bcast_addr.dev_addr, 0xff, ETH_ALEN); 271 272 memset(eth_bearers, 0, sizeof(eth_bearers)); 273 274 res = tipc_register_media(TIPC_MEDIA_TYPE_ETH, "eth", 275 enable_bearer, disable_bearer, send_msg, 276 eth_addr2str, &bcast_addr, ETH_LINK_PRIORITY, 277 ETH_LINK_TOLERANCE, ETH_LINK_WINDOW); 278 if (res) 279 return res; 280 281 notifier.notifier_call = &recv_notification; 282 notifier.priority = 0; 283 res = register_netdevice_notifier(¬ifier); 284 if (!res) 285 eth_started = 1; 286 return res; 287 } 288 289 /** 290 * tipc_eth_media_stop - deactivate Ethernet bearer support 291 */ 292 293 void tipc_eth_media_stop(void) 294 { 295 int i; 296 297 if (!eth_started) 298 return; 299 300 unregister_netdevice_notifier(¬ifier); 301 for (i = 0; i < MAX_ETH_BEARERS ; i++) { 302 if (eth_bearers[i].bearer) { 303 eth_bearers[i].bearer->blocked = 1; 304 eth_bearers[i].bearer = NULL; 305 } 306 if (eth_bearers[i].dev) { 307 dev_remove_pack(ð_bearers[i].tipc_packet_type); 308 dev_put(eth_bearers[i].dev); 309 } 310 } 311 memset(ð_bearers, 0, sizeof(eth_bearers)); 312 eth_started = 0; 313 } 314