| 1 | /* |
| 2 | * INET An implementation of the TCP/IP protocol suite for the LINUX |
| 3 | * operating system. INET is implemented using the BSD Socket |
| 4 | * interface as the means of communication with the user level. |
| 5 | * |
| 6 | * Ethernet-type device handling. |
| 7 | * |
| 8 | * Version: @(#)eth.c 1.0.7 05/25/93 |
| 9 | * |
| 10 | * Authors: Ross Biro |
| 11 | * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
| 12 | * Mark Evans, <evansmp@uhura.aston.ac.uk> |
| 13 | * Florian La Roche, <rzsfl@rz.uni-sb.de> |
| 14 | * Alan Cox, <gw4pts@gw4pts.ampr.org> |
| 15 | * |
| 16 | * Fixes: |
| 17 | * Mr Linux : Arp problems |
| 18 | * Alan Cox : Generic queue tidyup (very tiny here) |
| 19 | * Alan Cox : eth_header ntohs should be htons |
| 20 | * Alan Cox : eth_rebuild_header missing an htons and |
| 21 | * minor other things. |
| 22 | * Tegge : Arp bug fixes. |
| 23 | * Florian : Removed many unnecessary functions, code cleanup |
| 24 | * and changes for new arp and skbuff. |
| 25 | * Alan Cox : Redid header building to reflect new format. |
| 26 | * Alan Cox : ARP only when compiled with CONFIG_INET |
| 27 | * Greg Page : 802.2 and SNAP stuff. |
| 28 | * Alan Cox : MAC layer pointers/new format. |
| 29 | * Paul Gortmaker : eth_copy_and_sum shouldn't csum padding. |
| 30 | * Alan Cox : Protect against forwarding explosions with |
| 31 | * older network drivers and IFF_ALLMULTI. |
| 32 | * Christer Weinigel : Better rebuild header message. |
| 33 | * Andrew Morton : 26Feb01: kill ether_setup() - use netdev_boot_setup(). |
| 34 | * |
| 35 | * This program is free software; you can redistribute it and/or |
| 36 | * modify it under the terms of the GNU General Public License |
| 37 | * as published by the Free Software Foundation; either version |
| 38 | * 2 of the License, or (at your option) any later version. |
| 39 | */ |
| 40 | #include <linux/module.h> |
| 41 | #include <linux/types.h> |
| 42 | #include <linux/kernel.h> |
| 43 | #include <linux/string.h> |
| 44 | #include <linux/mm.h> |
| 45 | #include <linux/socket.h> |
| 46 | #include <linux/in.h> |
| 47 | #include <linux/inet.h> |
| 48 | #include <linux/ip.h> |
| 49 | #include <linux/netdevice.h> |
| 50 | #include <linux/etherdevice.h> |
| 51 | #include <linux/skbuff.h> |
| 52 | #include <linux/errno.h> |
| 53 | #include <linux/init.h> |
| 54 | #include <linux/if_ether.h> |
| 55 | #include <net/dst.h> |
| 56 | #include <net/arp.h> |
| 57 | #include <net/sock.h> |
| 58 | #include <net/ipv6.h> |
| 59 | #include <net/ip.h> |
| 60 | #include <net/dsa.h> |
| 61 | #include <asm/uaccess.h> |
| 62 | |
| 63 | __setup("ether=", netdev_boot_setup); |
| 64 | |
| 65 | /** |
| 66 | * eth_header - create the Ethernet header |
| 67 | * @skb: buffer to alter |
| 68 | * @dev: source device |
| 69 | * @type: Ethernet type field |
| 70 | * @daddr: destination address (NULL leave destination address) |
| 71 | * @saddr: source address (NULL use device source address) |
| 72 | * @len: packet length (<= skb->len) |
| 73 | * |
| 74 | * |
| 75 | * Set the protocol type. For a packet of type ETH_P_802_3/2 we put the length |
| 76 | * in here instead. |
| 77 | */ |
| 78 | int eth_header(struct sk_buff *skb, struct net_device *dev, |
| 79 | unsigned short type, |
| 80 | const void *daddr, const void *saddr, unsigned int len) |
| 81 | { |
| 82 | struct ethhdr *eth = (struct ethhdr *)skb_push(skb, ETH_HLEN); |
| 83 | |
| 84 | if (type != ETH_P_802_3 && type != ETH_P_802_2) |
| 85 | eth->h_proto = htons(type); |
| 86 | else |
| 87 | eth->h_proto = htons(len); |
| 88 | |
| 89 | /* |
| 90 | * Set the source hardware address. |
| 91 | */ |
| 92 | |
| 93 | if (!saddr) |
| 94 | saddr = dev->dev_addr; |
| 95 | memcpy(eth->h_source, saddr, ETH_ALEN); |
| 96 | |
| 97 | if (daddr) { |
| 98 | memcpy(eth->h_dest, daddr, ETH_ALEN); |
| 99 | return ETH_HLEN; |
| 100 | } |
| 101 | |
| 102 | /* |
| 103 | * Anyway, the loopback-device should never use this function... |
| 104 | */ |
| 105 | |
| 106 | if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) { |
| 107 | memset(eth->h_dest, 0, ETH_ALEN); |
| 108 | return ETH_HLEN; |
| 109 | } |
| 110 | |
| 111 | return -ETH_HLEN; |
| 112 | } |
| 113 | EXPORT_SYMBOL(eth_header); |
| 114 | |
| 115 | /** |
| 116 | * eth_rebuild_header- rebuild the Ethernet MAC header. |
| 117 | * @skb: socket buffer to update |
| 118 | * |
| 119 | * This is called after an ARP or IPV6 ndisc it's resolution on this |
| 120 | * sk_buff. We now let protocol (ARP) fill in the other fields. |
| 121 | * |
| 122 | * This routine CANNOT use cached dst->neigh! |
| 123 | * Really, it is used only when dst->neigh is wrong. |
| 124 | */ |
| 125 | int eth_rebuild_header(struct sk_buff *skb) |
| 126 | { |
| 127 | struct ethhdr *eth = (struct ethhdr *)skb->data; |
| 128 | struct net_device *dev = skb->dev; |
| 129 | |
| 130 | switch (eth->h_proto) { |
| 131 | #ifdef CONFIG_INET |
| 132 | case htons(ETH_P_IP): |
| 133 | return arp_find(eth->h_dest, skb); |
| 134 | #endif |
| 135 | default: |
| 136 | printk(KERN_DEBUG |
| 137 | "%s: unable to resolve type %X addresses.\n", |
| 138 | dev->name, ntohs(eth->h_proto)); |
| 139 | |
| 140 | memcpy(eth->h_source, dev->dev_addr, ETH_ALEN); |
| 141 | break; |
| 142 | } |
| 143 | |
| 144 | return 0; |
| 145 | } |
| 146 | EXPORT_SYMBOL(eth_rebuild_header); |
| 147 | |
| 148 | /** |
| 149 | * eth_type_trans - determine the packet's protocol ID. |
| 150 | * @skb: received socket data |
| 151 | * @dev: receiving network device |
| 152 | * |
| 153 | * The rule here is that we |
| 154 | * assume 802.3 if the type field is short enough to be a length. |
| 155 | * This is normal practice and works for any 'now in use' protocol. |
| 156 | */ |
| 157 | __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev) |
| 158 | { |
| 159 | struct ethhdr *eth; |
| 160 | |
| 161 | skb->dev = dev; |
| 162 | skb_reset_mac_header(skb); |
| 163 | skb_pull_inline(skb, ETH_HLEN); |
| 164 | eth = eth_hdr(skb); |
| 165 | |
| 166 | if (unlikely(is_multicast_ether_addr(eth->h_dest))) { |
| 167 | if (ether_addr_equal_64bits(eth->h_dest, dev->broadcast)) |
| 168 | skb->pkt_type = PACKET_BROADCAST; |
| 169 | else |
| 170 | skb->pkt_type = PACKET_MULTICAST; |
| 171 | } |
| 172 | |
| 173 | /* |
| 174 | * This ALLMULTI check should be redundant by 1.4 |
| 175 | * so don't forget to remove it. |
| 176 | * |
| 177 | * Seems, you forgot to remove it. All silly devices |
| 178 | * seems to set IFF_PROMISC. |
| 179 | */ |
| 180 | |
| 181 | else if (1 /*dev->flags&IFF_PROMISC */ ) { |
| 182 | if (unlikely(!ether_addr_equal_64bits(eth->h_dest, |
| 183 | dev->dev_addr))) |
| 184 | skb->pkt_type = PACKET_OTHERHOST; |
| 185 | } |
| 186 | |
| 187 | /* |
| 188 | * Some variants of DSA tagging don't have an ethertype field |
| 189 | * at all, so we check here whether one of those tagging |
| 190 | * variants has been configured on the receiving interface, |
| 191 | * and if so, set skb->protocol without looking at the packet. |
| 192 | */ |
| 193 | if (netdev_uses_dsa_tags(dev)) |
| 194 | return htons(ETH_P_DSA); |
| 195 | if (netdev_uses_trailer_tags(dev)) |
| 196 | return htons(ETH_P_TRAILER); |
| 197 | |
| 198 | if (ntohs(eth->h_proto) >= ETH_P_802_3_MIN) |
| 199 | return eth->h_proto; |
| 200 | |
| 201 | /* |
| 202 | * This is a magic hack to spot IPX packets. Older Novell breaks |
| 203 | * the protocol design and runs IPX over 802.3 without an 802.2 LLC |
| 204 | * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This |
| 205 | * won't work for fault tolerant netware but does for the rest. |
| 206 | */ |
| 207 | if (skb->len >= 2 && *(unsigned short *)(skb->data) == 0xFFFF) |
| 208 | return htons(ETH_P_802_3); |
| 209 | |
| 210 | /* |
| 211 | * Real 802.2 LLC |
| 212 | */ |
| 213 | return htons(ETH_P_802_2); |
| 214 | } |
| 215 | EXPORT_SYMBOL(eth_type_trans); |
| 216 | |
| 217 | /** |
| 218 | * eth_header_parse - extract hardware address from packet |
| 219 | * @skb: packet to extract header from |
| 220 | * @haddr: destination buffer |
| 221 | */ |
| 222 | int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr) |
| 223 | { |
| 224 | const struct ethhdr *eth = eth_hdr(skb); |
| 225 | memcpy(haddr, eth->h_source, ETH_ALEN); |
| 226 | return ETH_ALEN; |
| 227 | } |
| 228 | EXPORT_SYMBOL(eth_header_parse); |
| 229 | |
| 230 | /** |
| 231 | * eth_header_cache - fill cache entry from neighbour |
| 232 | * @neigh: source neighbour |
| 233 | * @hh: destination cache entry |
| 234 | * @type: Ethernet type field |
| 235 | * |
| 236 | * Create an Ethernet header template from the neighbour. |
| 237 | */ |
| 238 | int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, __be16 type) |
| 239 | { |
| 240 | struct ethhdr *eth; |
| 241 | const struct net_device *dev = neigh->dev; |
| 242 | |
| 243 | eth = (struct ethhdr *) |
| 244 | (((u8 *) hh->hh_data) + (HH_DATA_OFF(sizeof(*eth)))); |
| 245 | |
| 246 | if (type == htons(ETH_P_802_3)) |
| 247 | return -1; |
| 248 | |
| 249 | eth->h_proto = type; |
| 250 | memcpy(eth->h_source, dev->dev_addr, ETH_ALEN); |
| 251 | memcpy(eth->h_dest, neigh->ha, ETH_ALEN); |
| 252 | hh->hh_len = ETH_HLEN; |
| 253 | return 0; |
| 254 | } |
| 255 | EXPORT_SYMBOL(eth_header_cache); |
| 256 | |
| 257 | /** |
| 258 | * eth_header_cache_update - update cache entry |
| 259 | * @hh: destination cache entry |
| 260 | * @dev: network device |
| 261 | * @haddr: new hardware address |
| 262 | * |
| 263 | * Called by Address Resolution module to notify changes in address. |
| 264 | */ |
| 265 | void eth_header_cache_update(struct hh_cache *hh, |
| 266 | const struct net_device *dev, |
| 267 | const unsigned char *haddr) |
| 268 | { |
| 269 | memcpy(((u8 *) hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)), |
| 270 | haddr, ETH_ALEN); |
| 271 | } |
| 272 | EXPORT_SYMBOL(eth_header_cache_update); |
| 273 | |
| 274 | /** |
| 275 | * eth_prepare_mac_addr_change - prepare for mac change |
| 276 | * @dev: network device |
| 277 | * @p: socket address |
| 278 | */ |
| 279 | int eth_prepare_mac_addr_change(struct net_device *dev, void *p) |
| 280 | { |
| 281 | struct sockaddr *addr = p; |
| 282 | |
| 283 | if (!(dev->priv_flags & IFF_LIVE_ADDR_CHANGE) && netif_running(dev)) |
| 284 | return -EBUSY; |
| 285 | if (!is_valid_ether_addr(addr->sa_data)) |
| 286 | return -EADDRNOTAVAIL; |
| 287 | return 0; |
| 288 | } |
| 289 | EXPORT_SYMBOL(eth_prepare_mac_addr_change); |
| 290 | |
| 291 | /** |
| 292 | * eth_commit_mac_addr_change - commit mac change |
| 293 | * @dev: network device |
| 294 | * @p: socket address |
| 295 | */ |
| 296 | void eth_commit_mac_addr_change(struct net_device *dev, void *p) |
| 297 | { |
| 298 | struct sockaddr *addr = p; |
| 299 | |
| 300 | memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN); |
| 301 | } |
| 302 | EXPORT_SYMBOL(eth_commit_mac_addr_change); |
| 303 | |
| 304 | /** |
| 305 | * eth_mac_addr - set new Ethernet hardware address |
| 306 | * @dev: network device |
| 307 | * @p: socket address |
| 308 | * |
| 309 | * Change hardware address of device. |
| 310 | * |
| 311 | * This doesn't change hardware matching, so needs to be overridden |
| 312 | * for most real devices. |
| 313 | */ |
| 314 | int eth_mac_addr(struct net_device *dev, void *p) |
| 315 | { |
| 316 | int ret; |
| 317 | |
| 318 | ret = eth_prepare_mac_addr_change(dev, p); |
| 319 | if (ret < 0) |
| 320 | return ret; |
| 321 | eth_commit_mac_addr_change(dev, p); |
| 322 | return 0; |
| 323 | } |
| 324 | EXPORT_SYMBOL(eth_mac_addr); |
| 325 | |
| 326 | /** |
| 327 | * eth_change_mtu - set new MTU size |
| 328 | * @dev: network device |
| 329 | * @new_mtu: new Maximum Transfer Unit |
| 330 | * |
| 331 | * Allow changing MTU size. Needs to be overridden for devices |
| 332 | * supporting jumbo frames. |
| 333 | */ |
| 334 | int eth_change_mtu(struct net_device *dev, int new_mtu) |
| 335 | { |
| 336 | if (new_mtu < 68 || new_mtu > ETH_DATA_LEN) |
| 337 | return -EINVAL; |
| 338 | dev->mtu = new_mtu; |
| 339 | return 0; |
| 340 | } |
| 341 | EXPORT_SYMBOL(eth_change_mtu); |
| 342 | |
| 343 | int eth_validate_addr(struct net_device *dev) |
| 344 | { |
| 345 | if (!is_valid_ether_addr(dev->dev_addr)) |
| 346 | return -EADDRNOTAVAIL; |
| 347 | |
| 348 | return 0; |
| 349 | } |
| 350 | EXPORT_SYMBOL(eth_validate_addr); |
| 351 | |
| 352 | const struct header_ops eth_header_ops ____cacheline_aligned = { |
| 353 | .create = eth_header, |
| 354 | .parse = eth_header_parse, |
| 355 | .rebuild = eth_rebuild_header, |
| 356 | .cache = eth_header_cache, |
| 357 | .cache_update = eth_header_cache_update, |
| 358 | }; |
| 359 | |
| 360 | /** |
| 361 | * ether_setup - setup Ethernet network device |
| 362 | * @dev: network device |
| 363 | * |
| 364 | * Fill in the fields of the device structure with Ethernet-generic values. |
| 365 | */ |
| 366 | void ether_setup(struct net_device *dev) |
| 367 | { |
| 368 | dev->header_ops = ð_header_ops; |
| 369 | dev->type = ARPHRD_ETHER; |
| 370 | dev->hard_header_len = ETH_HLEN; |
| 371 | dev->mtu = ETH_DATA_LEN; |
| 372 | dev->addr_len = ETH_ALEN; |
| 373 | dev->tx_queue_len = 1000; /* Ethernet wants good queues */ |
| 374 | dev->flags = IFF_BROADCAST|IFF_MULTICAST; |
| 375 | dev->priv_flags |= IFF_TX_SKB_SHARING; |
| 376 | |
| 377 | memset(dev->broadcast, 0xFF, ETH_ALEN); |
| 378 | |
| 379 | } |
| 380 | EXPORT_SYMBOL(ether_setup); |
| 381 | |
| 382 | /** |
| 383 | * alloc_etherdev_mqs - Allocates and sets up an Ethernet device |
| 384 | * @sizeof_priv: Size of additional driver-private structure to be allocated |
| 385 | * for this Ethernet device |
| 386 | * @txqs: The number of TX queues this device has. |
| 387 | * @rxqs: The number of RX queues this device has. |
| 388 | * |
| 389 | * Fill in the fields of the device structure with Ethernet-generic |
| 390 | * values. Basically does everything except registering the device. |
| 391 | * |
| 392 | * Constructs a new net device, complete with a private data area of |
| 393 | * size (sizeof_priv). A 32-byte (not bit) alignment is enforced for |
| 394 | * this private data area. |
| 395 | */ |
| 396 | |
| 397 | struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs, |
| 398 | unsigned int rxqs) |
| 399 | { |
| 400 | return alloc_netdev_mqs(sizeof_priv, "eth%d", ether_setup, txqs, rxqs); |
| 401 | } |
| 402 | EXPORT_SYMBOL(alloc_etherdev_mqs); |
| 403 | |
| 404 | ssize_t sysfs_format_mac(char *buf, const unsigned char *addr, int len) |
| 405 | { |
| 406 | return scnprintf(buf, PAGE_SIZE, "%*phC\n", len, addr); |
| 407 | } |
| 408 | EXPORT_SYMBOL(sysfs_format_mac); |