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 56struct eth_bearer { 57 struct tipc_bearer *bearer; 58 struct net_device *dev; 59 struct packet_type tipc_packet_type; 60}; 61 62static struct eth_bearer eth_bearers[MAX_ETH_BEARERS]; 63static int eth_started = 0; 64static struct notifier_block notifier; 65 66/** 67 * send_msg - send a TIPC message out over an Ethernet interface 68 */ 69 70static 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 76 clone = skb_clone(buf, GFP_ATOMIC); 77 if (clone) { 78 skb_reset_network_header(clone); 79 dev = ((struct eth_bearer *)(tb_ptr->usr_handle))->dev; 80 clone->dev = dev; 81 dev_hard_header(clone, dev, ETH_P_TIPC, 82 &dest->dev_addr.eth_addr, 83 dev->dev_addr, clone->len); 84 dev_queue_xmit(clone); 85 } 86 return 0; 87} 88 89/** 90 * recv_msg - handle incoming TIPC message from an Ethernet interface 91 * 92 * Accept only packets explicitly sent to this node, or broadcast packets; 93 * ignores packets sent using Ethernet multicast, and traffic sent to other 94 * nodes (which can happen if interface is running in promiscuous mode). 95 * Routine truncates any Ethernet padding/CRC appended to the message, 96 * and ensures message size matches actual length 97 */ 98 99static int recv_msg(struct sk_buff *buf, struct net_device *dev, 100 struct packet_type *pt, struct net_device *orig_dev) 101{ 102 struct eth_bearer *eb_ptr = (struct eth_bearer *)pt->af_packet_priv; 103 u32 size; 104 105 if (!net_eq(dev_net(dev), &init_net)) { 106 kfree_skb(buf); 107 return 0; 108 } 109 110 if (likely(eb_ptr->bearer)) { 111 if (likely(buf->pkt_type <= PACKET_BROADCAST)) { 112 size = msg_size((struct tipc_msg *)buf->data); 113 skb_trim(buf, size); 114 if (likely(buf->len == size)) { 115 buf->next = NULL; 116 tipc_recv_msg(buf, eb_ptr->bearer); 117 return 0; 118 } 119 } 120 } 121 kfree_skb(buf); 122 return 0; 123} 124 125/** 126 * enable_bearer - attach TIPC bearer to an Ethernet interface 127 */ 128 129static int enable_bearer(struct tipc_bearer *tb_ptr) 130{ 131 struct net_device *dev = NULL; 132 struct net_device *pdev = NULL; 133 struct eth_bearer *eb_ptr = ð_bearers[0]; 134 struct eth_bearer *stop = ð_bearers[MAX_ETH_BEARERS]; 135 char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1; 136 137 /* Find device with specified name */ 138 139 for_each_netdev(&init_net, pdev){ 140 if (!strncmp(pdev->name, driver_name, IFNAMSIZ)) { 141 dev = pdev; 142 break; 143 } 144 } 145 if (!dev) 146 return -ENODEV; 147 148 /* Find Ethernet bearer for device (or create one) */ 149 150 for (;(eb_ptr != stop) && eb_ptr->dev && (eb_ptr->dev != dev); eb_ptr++); 151 if (eb_ptr == stop) 152 return -EDQUOT; 153 if (!eb_ptr->dev) { 154 eb_ptr->dev = dev; 155 eb_ptr->tipc_packet_type.type = htons(ETH_P_TIPC); 156 eb_ptr->tipc_packet_type.dev = dev; 157 eb_ptr->tipc_packet_type.func = recv_msg; 158 eb_ptr->tipc_packet_type.af_packet_priv = eb_ptr; 159 INIT_LIST_HEAD(&(eb_ptr->tipc_packet_type.list)); 160 dev_hold(dev); 161 dev_add_pack(&eb_ptr->tipc_packet_type); 162 } 163 164 /* Associate TIPC bearer with Ethernet bearer */ 165 166 eb_ptr->bearer = tb_ptr; 167 tb_ptr->usr_handle = (void *)eb_ptr; 168 tb_ptr->mtu = dev->mtu; 169 tb_ptr->blocked = 0; 170 tb_ptr->addr.type = htonl(TIPC_MEDIA_TYPE_ETH); 171 memcpy(&tb_ptr->addr.dev_addr, dev->dev_addr, ETH_ALEN); 172 return 0; 173} 174 175/** 176 * disable_bearer - detach TIPC bearer from an Ethernet interface 177 * 178 * We really should do dev_remove_pack() here, but this function can not be 179 * called at tasklet level. => Use eth_bearer->bearer as a flag to throw away 180 * incoming buffers, & postpone dev_remove_pack() to eth_media_stop() on exit. 181 */ 182 183static void disable_bearer(struct tipc_bearer *tb_ptr) 184{ 185 ((struct eth_bearer *)tb_ptr->usr_handle)->bearer = NULL; 186} 187 188/** 189 * recv_notification - handle device updates from OS 190 * 191 * Change the state of the Ethernet bearer (if any) associated with the 192 * specified device. 193 */ 194 195static int recv_notification(struct notifier_block *nb, unsigned long evt, 196 void *dv) 197{ 198 struct net_device *dev = (struct net_device *)dv; 199 struct eth_bearer *eb_ptr = ð_bearers[0]; 200 struct eth_bearer *stop = ð_bearers[MAX_ETH_BEARERS]; 201 202 if (!net_eq(dev_net(dev), &init_net)) 203 return NOTIFY_DONE; 204 205 while ((eb_ptr->dev != dev)) { 206 if (++eb_ptr == stop) 207 return NOTIFY_DONE; /* couldn't find device */ 208 } 209 if (!eb_ptr->bearer) 210 return NOTIFY_DONE; /* bearer had been disabled */ 211 212 eb_ptr->bearer->mtu = dev->mtu; 213 214 switch (evt) { 215 case NETDEV_CHANGE: 216 if (netif_carrier_ok(dev)) 217 tipc_continue(eb_ptr->bearer); 218 else 219 tipc_block_bearer(eb_ptr->bearer->name); 220 break; 221 case NETDEV_UP: 222 tipc_continue(eb_ptr->bearer); 223 break; 224 case NETDEV_DOWN: 225 tipc_block_bearer(eb_ptr->bearer->name); 226 break; 227 case NETDEV_CHANGEMTU: 228 case NETDEV_CHANGEADDR: 229 tipc_block_bearer(eb_ptr->bearer->name); 230 tipc_continue(eb_ptr->bearer); 231 break; 232 case NETDEV_UNREGISTER: 233 case NETDEV_CHANGENAME: 234 tipc_disable_bearer(eb_ptr->bearer->name); 235 break; 236 } 237 return NOTIFY_OK; 238} 239 240/** 241 * eth_addr2str - convert Ethernet address to string 242 */ 243 244static char *eth_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size) 245{ 246 unchar *addr = (unchar *)&a->dev_addr; 247 248 if (str_size < 18) 249 *str_buf = '\0'; 250 else 251 sprintf(str_buf, "%pM", addr); 252 return str_buf; 253} 254 255/** 256 * tipc_eth_media_start - activate Ethernet bearer support 257 * 258 * Register Ethernet media type with TIPC bearer code. Also register 259 * with OS for notifications about device state changes. 260 */ 261 262int tipc_eth_media_start(void) 263{ 264 struct tipc_media_addr bcast_addr; 265 int res; 266 267 if (eth_started) 268 return -EINVAL; 269 270 bcast_addr.type = htonl(TIPC_MEDIA_TYPE_ETH); 271 memset(&bcast_addr.dev_addr, 0xff, ETH_ALEN); 272 273 memset(eth_bearers, 0, sizeof(eth_bearers)); 274 275 res = tipc_register_media(TIPC_MEDIA_TYPE_ETH, "eth", 276 enable_bearer, disable_bearer, send_msg, 277 eth_addr2str, &bcast_addr, ETH_LINK_PRIORITY, 278 ETH_LINK_TOLERANCE, ETH_LINK_WINDOW); 279 if (res) 280 return res; 281 282 notifier.notifier_call = &recv_notification; 283 notifier.priority = 0; 284 res = register_netdevice_notifier(¬ifier); 285 if (!res) 286 eth_started = 1; 287 return res; 288} 289 290/** 291 * tipc_eth_media_stop - deactivate Ethernet bearer support 292 */ 293 294void tipc_eth_media_stop(void) 295{ 296 int i; 297 298 if (!eth_started) 299 return; 300 301 unregister_netdevice_notifier(¬ifier); 302 for (i = 0; i < MAX_ETH_BEARERS ; i++) { 303 if (eth_bearers[i].bearer) { 304 eth_bearers[i].bearer->blocked = 1; 305 eth_bearers[i].bearer = NULL; 306 } 307 if (eth_bearers[i].dev) { 308 dev_remove_pack(ð_bearers[i].tipc_packet_type); 309 dev_put(eth_bearers[i].dev); 310 } 311 } 312 memset(ð_bearers, 0, sizeof(eth_bearers)); 313 eth_started = 0; 314} 315