1 /* 2 * net/tipc/eth_media.c: Ethernet bearer support for TIPC 3 * 4 * Copyright (c) 2001-2006, Ericsson AB 5 * Copyright (c) 2005, 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 42 #define MAX_ETH_BEARERS 2 43 #define ETH_LINK_PRIORITY TIPC_DEF_LINK_PRI 44 #define ETH_LINK_TOLERANCE TIPC_DEF_LINK_TOL 45 #define ETH_LINK_WINDOW TIPC_DEF_LINK_WIN 46 47 /** 48 * struct eth_bearer - Ethernet bearer data structure 49 * @bearer: ptr to associated "generic" bearer structure 50 * @dev: ptr to associated Ethernet network device 51 * @tipc_packet_type: used in binding TIPC to Ethernet driver 52 */ 53 54 struct eth_bearer { 55 struct tipc_bearer *bearer; 56 struct net_device *dev; 57 struct packet_type tipc_packet_type; 58 }; 59 60 static struct eth_bearer eth_bearers[MAX_ETH_BEARERS]; 61 static int eth_started = 0; 62 static struct notifier_block notifier; 63 64 /** 65 * send_msg - send a TIPC message out over an Ethernet interface 66 */ 67 68 static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr, 69 struct tipc_media_addr *dest) 70 { 71 struct sk_buff *clone; 72 struct net_device *dev; 73 74 clone = skb_clone(buf, GFP_ATOMIC); 75 if (clone) { 76 clone->nh.raw = clone->data; 77 dev = ((struct eth_bearer *)(tb_ptr->usr_handle))->dev; 78 clone->dev = dev; 79 dev->hard_header(clone, dev, ETH_P_TIPC, 80 &dest->dev_addr.eth_addr, 81 dev->dev_addr, clone->len); 82 dev_queue_xmit(clone); 83 } 84 return TIPC_OK; 85 } 86 87 /** 88 * recv_msg - handle incoming TIPC message from an Ethernet interface 89 * 90 * Routine truncates any Ethernet padding/CRC appended to the message, 91 * and ensures message size matches actual length 92 */ 93 94 static int recv_msg(struct sk_buff *buf, struct net_device *dev, 95 struct packet_type *pt, struct net_device *orig_dev) 96 { 97 struct eth_bearer *eb_ptr = (struct eth_bearer *)pt->af_packet_priv; 98 u32 size; 99 100 if (likely(eb_ptr->bearer)) { 101 size = msg_size((struct tipc_msg *)buf->data); 102 skb_trim(buf, size); 103 if (likely(buf->len == size)) { 104 buf->next = NULL; 105 tipc_recv_msg(buf, eb_ptr->bearer); 106 } else { 107 kfree_skb(buf); 108 } 109 } else { 110 kfree_skb(buf); 111 } 112 return TIPC_OK; 113 } 114 115 /** 116 * enable_bearer - attach TIPC bearer to an Ethernet interface 117 */ 118 119 static int enable_bearer(struct tipc_bearer *tb_ptr) 120 { 121 struct net_device *dev = dev_base; 122 struct eth_bearer *eb_ptr = ð_bearers[0]; 123 struct eth_bearer *stop = ð_bearers[MAX_ETH_BEARERS]; 124 char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1; 125 126 /* Find device with specified name */ 127 128 while (dev && dev->name && 129 (memcmp(dev->name, driver_name, strlen(dev->name)))) { 130 dev = dev->next; 131 } 132 if (!dev) 133 return -ENODEV; 134 135 /* Find Ethernet bearer for device (or create one) */ 136 137 for (;(eb_ptr != stop) && eb_ptr->dev && (eb_ptr->dev != dev); eb_ptr++); 138 if (eb_ptr == stop) 139 return -EDQUOT; 140 if (!eb_ptr->dev) { 141 eb_ptr->dev = dev; 142 eb_ptr->tipc_packet_type.type = __constant_htons(ETH_P_TIPC); 143 eb_ptr->tipc_packet_type.dev = dev; 144 eb_ptr->tipc_packet_type.func = recv_msg; 145 eb_ptr->tipc_packet_type.af_packet_priv = eb_ptr; 146 INIT_LIST_HEAD(&(eb_ptr->tipc_packet_type.list)); 147 dev_hold(dev); 148 dev_add_pack(&eb_ptr->tipc_packet_type); 149 } 150 151 /* Associate TIPC bearer with Ethernet bearer */ 152 153 eb_ptr->bearer = tb_ptr; 154 tb_ptr->usr_handle = (void *)eb_ptr; 155 tb_ptr->mtu = dev->mtu; 156 tb_ptr->blocked = 0; 157 tb_ptr->addr.type = htonl(TIPC_MEDIA_TYPE_ETH); 158 memcpy(&tb_ptr->addr.dev_addr, &dev->dev_addr, ETH_ALEN); 159 return 0; 160 } 161 162 /** 163 * disable_bearer - detach TIPC bearer from an Ethernet interface 164 * 165 * We really should do dev_remove_pack() here, but this function can not be 166 * called at tasklet level. => Use eth_bearer->bearer as a flag to throw away 167 * incoming buffers, & postpone dev_remove_pack() to eth_media_stop() on exit. 168 */ 169 170 static void disable_bearer(struct tipc_bearer *tb_ptr) 171 { 172 ((struct eth_bearer *)tb_ptr->usr_handle)->bearer = NULL; 173 } 174 175 /** 176 * recv_notification - handle device updates from OS 177 * 178 * Change the state of the Ethernet bearer (if any) associated with the 179 * specified device. 180 */ 181 182 static int recv_notification(struct notifier_block *nb, unsigned long evt, 183 void *dv) 184 { 185 struct net_device *dev = (struct net_device *)dv; 186 struct eth_bearer *eb_ptr = ð_bearers[0]; 187 struct eth_bearer *stop = ð_bearers[MAX_ETH_BEARERS]; 188 189 while ((eb_ptr->dev != dev)) { 190 if (++eb_ptr == stop) 191 return NOTIFY_DONE; /* couldn't find device */ 192 } 193 if (!eb_ptr->bearer) 194 return NOTIFY_DONE; /* bearer had been disabled */ 195 196 eb_ptr->bearer->mtu = dev->mtu; 197 198 switch (evt) { 199 case NETDEV_CHANGE: 200 if (netif_carrier_ok(dev)) 201 tipc_continue(eb_ptr->bearer); 202 else 203 tipc_block_bearer(eb_ptr->bearer->name); 204 break; 205 case NETDEV_UP: 206 tipc_continue(eb_ptr->bearer); 207 break; 208 case NETDEV_DOWN: 209 tipc_block_bearer(eb_ptr->bearer->name); 210 break; 211 case NETDEV_CHANGEMTU: 212 case NETDEV_CHANGEADDR: 213 tipc_block_bearer(eb_ptr->bearer->name); 214 tipc_continue(eb_ptr->bearer); 215 break; 216 case NETDEV_UNREGISTER: 217 case NETDEV_CHANGENAME: 218 tipc_disable_bearer(eb_ptr->bearer->name); 219 break; 220 } 221 return NOTIFY_OK; 222 } 223 224 /** 225 * eth_addr2str - convert Ethernet address to string 226 */ 227 228 static char *eth_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size) 229 { 230 unchar *addr = (unchar *)&a->dev_addr; 231 232 if (str_size < 18) 233 *str_buf = '\0'; 234 else 235 sprintf(str_buf, "%02x:%02x:%02x:%02x:%02x:%02x", 236 addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]); 237 return str_buf; 238 } 239 240 /** 241 * tipc_eth_media_start - activate Ethernet bearer support 242 * 243 * Register Ethernet media type with TIPC bearer code. Also register 244 * with OS for notifications about device state changes. 245 */ 246 247 int tipc_eth_media_start(void) 248 { 249 struct tipc_media_addr bcast_addr; 250 int res; 251 252 if (eth_started) 253 return -EINVAL; 254 255 memset(&bcast_addr, 0xff, sizeof(bcast_addr)); 256 memset(eth_bearers, 0, sizeof(eth_bearers)); 257 258 res = tipc_register_media(TIPC_MEDIA_TYPE_ETH, "eth", 259 enable_bearer, disable_bearer, send_msg, 260 eth_addr2str, &bcast_addr, ETH_LINK_PRIORITY, 261 ETH_LINK_TOLERANCE, ETH_LINK_WINDOW); 262 if (res) 263 return res; 264 265 notifier.notifier_call = &recv_notification; 266 notifier.priority = 0; 267 res = register_netdevice_notifier(¬ifier); 268 if (!res) 269 eth_started = 1; 270 return res; 271 } 272 273 /** 274 * tipc_eth_media_stop - deactivate Ethernet bearer support 275 */ 276 277 void tipc_eth_media_stop(void) 278 { 279 int i; 280 281 if (!eth_started) 282 return; 283 284 unregister_netdevice_notifier(¬ifier); 285 for (i = 0; i < MAX_ETH_BEARERS ; i++) { 286 if (eth_bearers[i].bearer) { 287 eth_bearers[i].bearer->blocked = 1; 288 eth_bearers[i].bearer = NULL; 289 } 290 if (eth_bearers[i].dev) { 291 dev_remove_pack(ð_bearers[i].tipc_packet_type); 292 dev_put(eth_bearers[i].dev); 293 } 294 } 295 memset(ð_bearers, 0, sizeof(eth_bearers)); 296 eth_started = 0; 297 } 298