| 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 | } |