1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * Ethernet-type device handling. 8 * 9 * Version: @(#)eth.c 1.0.7 05/25/93 10 * 11 * Authors: Ross Biro 12 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 13 * Mark Evans, <evansmp@uhura.aston.ac.uk> 14 * Florian La Roche, <rzsfl@rz.uni-sb.de> 15 * Alan Cox, <gw4pts@gw4pts.ampr.org> 16 * 17 * Fixes: 18 * Mr Linux : Arp problems 19 * Alan Cox : Generic queue tidyup (very tiny here) 20 * Alan Cox : eth_header ntohs should be htons 21 * Alan Cox : eth_rebuild_header missing an htons and 22 * minor other things. 23 * Tegge : Arp bug fixes. 24 * Florian : Removed many unnecessary functions, code cleanup 25 * and changes for new arp and skbuff. 26 * Alan Cox : Redid header building to reflect new format. 27 * Alan Cox : ARP only when compiled with CONFIG_INET 28 * Greg Page : 802.2 and SNAP stuff. 29 * Alan Cox : MAC layer pointers/new format. 30 * Paul Gortmaker : eth_copy_and_sum shouldn't csum padding. 31 * Alan Cox : Protect against forwarding explosions with 32 * older network drivers and IFF_ALLMULTI. 33 * Christer Weinigel : Better rebuild header message. 34 * Andrew Morton : 26Feb01: kill ether_setup() - use netdev_boot_setup(). 35 */ 36#include <linux/module.h> 37#include <linux/types.h> 38#include <linux/kernel.h> 39#include <linux/string.h> 40#include <linux/mm.h> 41#include <linux/socket.h> 42#include <linux/in.h> 43#include <linux/inet.h> 44#include <linux/ip.h> 45#include <linux/netdevice.h> 46#include <linux/nvmem-consumer.h> 47#include <linux/etherdevice.h> 48#include <linux/skbuff.h> 49#include <linux/errno.h> 50#include <linux/init.h> 51#include <linux/if_ether.h> 52#include <linux/of_net.h> 53#include <linux/pci.h> 54#include <linux/property.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 <net/flow_dissector.h> 62#include <net/gro.h> 63#include <linux/uaccess.h> 64#include <net/pkt_sched.h> 65 66/** 67 * eth_header - create the Ethernet header 68 * @skb: buffer to alter 69 * @dev: source device 70 * @type: Ethernet type field 71 * @daddr: destination address (NULL leave destination address) 72 * @saddr: source address (NULL use device source address) 73 * @len: packet length (<= skb->len) 74 * 75 * 76 * Set the protocol type. For a packet of type ETH_P_802_3/2 we put the length 77 * in here instead. 78 */ 79int eth_header(struct sk_buff *skb, struct net_device *dev, 80 unsigned short type, 81 const void *daddr, const void *saddr, unsigned int len) 82{ 83 struct ethhdr *eth = skb_push(skb, ETH_HLEN); 84 85 if (type != ETH_P_802_3 && type != ETH_P_802_2) 86 eth->h_proto = htons(type); 87 else 88 eth->h_proto = htons(len); 89 90 /* 91 * Set the source hardware address. 92 */ 93 94 if (!saddr) 95 saddr = dev->dev_addr; 96 memcpy(eth->h_source, saddr, ETH_ALEN); 97 98 if (daddr) { 99 memcpy(eth->h_dest, daddr, ETH_ALEN); 100 return ETH_HLEN; 101 } 102 103 /* 104 * Anyway, the loopback-device should never use this function... 105 */ 106 107 if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) { 108 eth_zero_addr(eth->h_dest); 109 return ETH_HLEN; 110 } 111 112 return -ETH_HLEN; 113} 114EXPORT_SYMBOL(eth_header); 115 116/** 117 * eth_get_headlen - determine the length of header for an ethernet frame 118 * @dev: pointer to network device 119 * @data: pointer to start of frame 120 * @len: total length of frame 121 * 122 * Make a best effort attempt to pull the length for all of the headers for 123 * a given frame in a linear buffer. 124 */ 125u32 eth_get_headlen(const struct net_device *dev, const void *data, u32 len) 126{ 127 const unsigned int flags = FLOW_DISSECTOR_F_PARSE_1ST_FRAG; 128 const struct ethhdr *eth = (const struct ethhdr *)data; 129 struct flow_keys_basic keys; 130 131 /* this should never happen, but better safe than sorry */ 132 if (unlikely(len < sizeof(*eth))) 133 return len; 134 135 /* parse any remaining L2/L3 headers, check for L4 */ 136 if (!skb_flow_dissect_flow_keys_basic(dev_net(dev), NULL, &keys, data, 137 eth->h_proto, sizeof(*eth), 138 len, flags)) 139 return max_t(u32, keys.control.thoff, sizeof(*eth)); 140 141 /* parse for any L4 headers */ 142 return min_t(u32, __skb_get_poff(NULL, data, &keys, len), len); 143} 144EXPORT_SYMBOL(eth_get_headlen); 145 146/** 147 * eth_type_trans - determine the packet's protocol ID. 148 * @skb: received socket data 149 * @dev: receiving network device 150 * 151 * The rule here is that we 152 * assume 802.3 if the type field is short enough to be a length. 153 * This is normal practice and works for any 'now in use' protocol. 154 */ 155__be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev) 156{ 157 unsigned short _service_access_point; 158 const unsigned short *sap; 159 const struct ethhdr *eth; 160 161 skb->dev = dev; 162 skb_reset_mac_header(skb); 163 164 eth = (struct ethhdr *)skb->data; 165 skb_pull_inline(skb, ETH_HLEN); 166 167 eth_skb_pkt_type(skb, dev); 168 169 /* 170 * Some variants of DSA tagging don't have an ethertype field 171 * at all, so we check here whether one of those tagging 172 * variants has been configured on the receiving interface, 173 * and if so, set skb->protocol without looking at the packet. 174 */ 175 if (unlikely(netdev_uses_dsa(dev))) 176 return htons(ETH_P_XDSA); 177 178 if (likely(eth_proto_is_802_3(eth->h_proto))) 179 return eth->h_proto; 180 181 /* 182 * This is a magic hack to spot IPX packets. Older Novell breaks 183 * the protocol design and runs IPX over 802.3 without an 802.2 LLC 184 * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This 185 * won't work for fault tolerant netware but does for the rest. 186 */ 187 sap = skb_header_pointer(skb, 0, sizeof(*sap), &_service_access_point); 188 if (sap && *sap == 0xFFFF) 189 return htons(ETH_P_802_3); 190 191 /* 192 * Real 802.2 LLC 193 */ 194 return htons(ETH_P_802_2); 195} 196EXPORT_SYMBOL(eth_type_trans); 197 198/** 199 * eth_header_parse - extract hardware address from packet 200 * @skb: packet to extract header from 201 * @haddr: destination buffer 202 */ 203int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr) 204{ 205 const struct ethhdr *eth = eth_hdr(skb); 206 memcpy(haddr, eth->h_source, ETH_ALEN); 207 return ETH_ALEN; 208} 209EXPORT_SYMBOL(eth_header_parse); 210 211/** 212 * eth_header_cache - fill cache entry from neighbour 213 * @neigh: source neighbour 214 * @hh: destination cache entry 215 * @type: Ethernet type field 216 * 217 * Create an Ethernet header template from the neighbour. 218 */ 219int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, __be16 type) 220{ 221 struct ethhdr *eth; 222 const struct net_device *dev = neigh->dev; 223 224 eth = (struct ethhdr *) 225 (((u8 *) hh->hh_data) + (HH_DATA_OFF(sizeof(*eth)))); 226 227 if (type == htons(ETH_P_802_3)) 228 return -1; 229 230 eth->h_proto = type; 231 memcpy(eth->h_source, dev->dev_addr, ETH_ALEN); 232 memcpy(eth->h_dest, neigh->ha, ETH_ALEN); 233 234 /* Pairs with READ_ONCE() in neigh_resolve_output(), 235 * neigh_hh_output() and neigh_update_hhs(). 236 */ 237 smp_store_release(&hh->hh_len, ETH_HLEN); 238 239 return 0; 240} 241EXPORT_SYMBOL(eth_header_cache); 242 243/** 244 * eth_header_cache_update - update cache entry 245 * @hh: destination cache entry 246 * @dev: network device 247 * @haddr: new hardware address 248 * 249 * Called by Address Resolution module to notify changes in address. 250 */ 251void eth_header_cache_update(struct hh_cache *hh, 252 const struct net_device *dev, 253 const unsigned char *haddr) 254{ 255 memcpy(((u8 *) hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)), 256 haddr, ETH_ALEN); 257} 258EXPORT_SYMBOL(eth_header_cache_update); 259 260/** 261 * eth_header_parse_protocol - extract protocol from L2 header 262 * @skb: packet to extract protocol from 263 */ 264__be16 eth_header_parse_protocol(const struct sk_buff *skb) 265{ 266 const struct ethhdr *eth = eth_hdr(skb); 267 268 return eth->h_proto; 269} 270EXPORT_SYMBOL(eth_header_parse_protocol); 271 272/** 273 * eth_prepare_mac_addr_change - prepare for mac change 274 * @dev: network device 275 * @p: socket address 276 */ 277int eth_prepare_mac_addr_change(struct net_device *dev, void *p) 278{ 279 struct sockaddr *addr = p; 280 281 if (!(dev->priv_flags & IFF_LIVE_ADDR_CHANGE) && netif_running(dev)) 282 return -EBUSY; 283 if (!is_valid_ether_addr(addr->sa_data)) 284 return -EADDRNOTAVAIL; 285 return 0; 286} 287EXPORT_SYMBOL(eth_prepare_mac_addr_change); 288 289/** 290 * eth_commit_mac_addr_change - commit mac change 291 * @dev: network device 292 * @p: socket address 293 */ 294void eth_commit_mac_addr_change(struct net_device *dev, void *p) 295{ 296 struct sockaddr *addr = p; 297 298 eth_hw_addr_set(dev, addr->sa_data); 299} 300EXPORT_SYMBOL(eth_commit_mac_addr_change); 301 302/** 303 * eth_mac_addr - set new Ethernet hardware address 304 * @dev: network device 305 * @p: socket address 306 * 307 * Change hardware address of device. 308 * 309 * This doesn't change hardware matching, so needs to be overridden 310 * for most real devices. 311 */ 312int eth_mac_addr(struct net_device *dev, void *p) 313{ 314 int ret; 315 316 ret = eth_prepare_mac_addr_change(dev, p); 317 if (ret < 0) 318 return ret; 319 eth_commit_mac_addr_change(dev, p); 320 return 0; 321} 322EXPORT_SYMBOL(eth_mac_addr); 323 324int eth_validate_addr(struct net_device *dev) 325{ 326 if (!is_valid_ether_addr(dev->dev_addr)) 327 return -EADDRNOTAVAIL; 328 329 return 0; 330} 331EXPORT_SYMBOL(eth_validate_addr); 332 333const struct header_ops eth_header_ops ____cacheline_aligned = { 334 .create = eth_header, 335 .parse = eth_header_parse, 336 .cache = eth_header_cache, 337 .cache_update = eth_header_cache_update, 338 .parse_protocol = eth_header_parse_protocol, 339}; 340 341/** 342 * ether_setup - setup Ethernet network device 343 * @dev: network device 344 * 345 * Fill in the fields of the device structure with Ethernet-generic values. 346 */ 347void ether_setup(struct net_device *dev) 348{ 349 dev->header_ops = ð_header_ops; 350 dev->type = ARPHRD_ETHER; 351 dev->hard_header_len = ETH_HLEN; 352 dev->min_header_len = ETH_HLEN; 353 dev->mtu = ETH_DATA_LEN; 354 dev->min_mtu = ETH_MIN_MTU; 355 dev->max_mtu = ETH_DATA_LEN; 356 dev->addr_len = ETH_ALEN; 357 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN; 358 dev->flags = IFF_BROADCAST|IFF_MULTICAST; 359 dev->priv_flags |= IFF_TX_SKB_SHARING; 360 361 eth_broadcast_addr(dev->broadcast); 362 363} 364EXPORT_SYMBOL(ether_setup); 365 366/** 367 * alloc_etherdev_mqs - Allocates and sets up an Ethernet device 368 * @sizeof_priv: Size of additional driver-private structure to be allocated 369 * for this Ethernet device 370 * @txqs: The number of TX queues this device has. 371 * @rxqs: The number of RX queues this device has. 372 * 373 * Fill in the fields of the device structure with Ethernet-generic 374 * values. Basically does everything except registering the device. 375 * 376 * Constructs a new net device, complete with a private data area of 377 * size (sizeof_priv). A 32-byte (not bit) alignment is enforced for 378 * this private data area. 379 */ 380 381struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs, 382 unsigned int rxqs) 383{ 384 return alloc_netdev_mqs(sizeof_priv, "eth%d", NET_NAME_ENUM, 385 ether_setup, txqs, rxqs); 386} 387EXPORT_SYMBOL(alloc_etherdev_mqs); 388 389ssize_t sysfs_format_mac(char *buf, const unsigned char *addr, int len) 390{ 391 return sysfs_emit(buf, "%*phC\n", len, addr); 392} 393EXPORT_SYMBOL(sysfs_format_mac); 394 395struct sk_buff *eth_gro_receive(struct list_head *head, struct sk_buff *skb) 396{ 397 const struct packet_offload *ptype; 398 unsigned int hlen, off_eth; 399 struct sk_buff *pp = NULL; 400 struct ethhdr *eh, *eh2; 401 struct sk_buff *p; 402 __be16 type; 403 int flush = 1; 404 405 off_eth = skb_gro_offset(skb); 406 hlen = off_eth + sizeof(*eh); 407 eh = skb_gro_header(skb, hlen, off_eth); 408 if (unlikely(!eh)) 409 goto out; 410 411 flush = 0; 412 413 list_for_each_entry(p, head, list) { 414 if (!NAPI_GRO_CB(p)->same_flow) 415 continue; 416 417 eh2 = (struct ethhdr *)(p->data + off_eth); 418 if (compare_ether_header(eh, eh2)) { 419 NAPI_GRO_CB(p)->same_flow = 0; 420 continue; 421 } 422 } 423 424 type = eh->h_proto; 425 426 ptype = gro_find_receive_by_type(type); 427 if (ptype == NULL) { 428 flush = 1; 429 goto out; 430 } 431 432 skb_gro_pull(skb, sizeof(*eh)); 433 skb_gro_postpull_rcsum(skb, eh, sizeof(*eh)); 434 435 pp = indirect_call_gro_receive_inet(ptype->callbacks.gro_receive, 436 ipv6_gro_receive, inet_gro_receive, 437 head, skb); 438 439out: 440 skb_gro_flush_final(skb, pp, flush); 441 442 return pp; 443} 444EXPORT_SYMBOL(eth_gro_receive); 445 446int eth_gro_complete(struct sk_buff *skb, int nhoff) 447{ 448 struct ethhdr *eh = (struct ethhdr *)(skb->data + nhoff); 449 __be16 type = eh->h_proto; 450 struct packet_offload *ptype; 451 int err = -ENOSYS; 452 453 if (skb->encapsulation) 454 skb_set_inner_mac_header(skb, nhoff); 455 456 ptype = gro_find_complete_by_type(type); 457 if (ptype != NULL) 458 err = INDIRECT_CALL_INET(ptype->callbacks.gro_complete, 459 ipv6_gro_complete, inet_gro_complete, 460 skb, nhoff + sizeof(*eh)); 461 462 return err; 463} 464EXPORT_SYMBOL(eth_gro_complete); 465 466static struct packet_offload eth_packet_offload __read_mostly = { 467 .type = cpu_to_be16(ETH_P_TEB), 468 .priority = 10, 469 .callbacks = { 470 .gro_receive = eth_gro_receive, 471 .gro_complete = eth_gro_complete, 472 }, 473}; 474 475static int __init eth_offload_init(void) 476{ 477 dev_add_offload(ð_packet_offload); 478 479 return 0; 480} 481 482fs_initcall(eth_offload_init); 483 484unsigned char * __weak arch_get_platform_mac_address(void) 485{ 486 return NULL; 487} 488 489int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr) 490{ 491 unsigned char *addr; 492 int ret; 493 494 ret = of_get_mac_address(dev->of_node, mac_addr); 495 if (!ret) 496 return 0; 497 498 addr = arch_get_platform_mac_address(); 499 if (!addr) 500 return -ENODEV; 501 502 ether_addr_copy(mac_addr, addr); 503 504 return 0; 505} 506EXPORT_SYMBOL(eth_platform_get_mac_address); 507 508/** 509 * platform_get_ethdev_address - Set netdev's MAC address from a given device 510 * @dev: Pointer to the device 511 * @netdev: Pointer to netdev to write the address to 512 * 513 * Wrapper around eth_platform_get_mac_address() which writes the address 514 * directly to netdev->dev_addr. 515 */ 516int platform_get_ethdev_address(struct device *dev, struct net_device *netdev) 517{ 518 u8 addr[ETH_ALEN] __aligned(2); 519 int ret; 520 521 ret = eth_platform_get_mac_address(dev, addr); 522 if (!ret) 523 eth_hw_addr_set(netdev, addr); 524 return ret; 525} 526EXPORT_SYMBOL(platform_get_ethdev_address); 527 528/** 529 * nvmem_get_mac_address - Obtain the MAC address from an nvmem cell named 530 * 'mac-address' associated with given device. 531 * 532 * @dev: Device with which the mac-address cell is associated. 533 * @addrbuf: Buffer to which the MAC address will be copied on success. 534 * 535 * Returns 0 on success or a negative error number on failure. 536 */ 537int nvmem_get_mac_address(struct device *dev, void *addrbuf) 538{ 539 struct nvmem_cell *cell; 540 const void *mac; 541 size_t len; 542 543 cell = nvmem_cell_get(dev, "mac-address"); 544 if (IS_ERR(cell)) 545 return PTR_ERR(cell); 546 547 mac = nvmem_cell_read(cell, &len); 548 nvmem_cell_put(cell); 549 550 if (IS_ERR(mac)) 551 return PTR_ERR(mac); 552 553 if (len != ETH_ALEN || !is_valid_ether_addr(mac)) { 554 kfree(mac); 555 return -EINVAL; 556 } 557 558 ether_addr_copy(addrbuf, mac); 559 kfree(mac); 560 561 return 0; 562} 563 564static int fwnode_get_mac_addr(struct fwnode_handle *fwnode, 565 const char *name, char *addr) 566{ 567 int ret; 568 569 ret = fwnode_property_read_u8_array(fwnode, name, addr, ETH_ALEN); 570 if (ret) 571 return ret; 572 573 if (!is_valid_ether_addr(addr)) 574 return -EINVAL; 575 return 0; 576} 577 578/** 579 * fwnode_get_mac_address - Get the MAC from the firmware node 580 * @fwnode: Pointer to the firmware node 581 * @addr: Address of buffer to store the MAC in 582 * 583 * Search the firmware node for the best MAC address to use. 'mac-address' is 584 * checked first, because that is supposed to contain to "most recent" MAC 585 * address. If that isn't set, then 'local-mac-address' is checked next, 586 * because that is the default address. If that isn't set, then the obsolete 587 * 'address' is checked, just in case we're using an old device tree. 588 * 589 * Note that the 'address' property is supposed to contain a virtual address of 590 * the register set, but some DTS files have redefined that property to be the 591 * MAC address. 592 * 593 * All-zero MAC addresses are rejected, because those could be properties that 594 * exist in the firmware tables, but were not updated by the firmware. For 595 * example, the DTS could define 'mac-address' and 'local-mac-address', with 596 * zero MAC addresses. Some older U-Boots only initialized 'local-mac-address'. 597 * In this case, the real MAC is in 'local-mac-address', and 'mac-address' 598 * exists but is all zeros. 599 */ 600int fwnode_get_mac_address(struct fwnode_handle *fwnode, char *addr) 601{ 602 if (!fwnode_get_mac_addr(fwnode, "mac-address", addr) || 603 !fwnode_get_mac_addr(fwnode, "local-mac-address", addr) || 604 !fwnode_get_mac_addr(fwnode, "address", addr)) 605 return 0; 606 607 return -ENOENT; 608} 609EXPORT_SYMBOL(fwnode_get_mac_address); 610 611/** 612 * device_get_mac_address - Get the MAC for a given device 613 * @dev: Pointer to the device 614 * @addr: Address of buffer to store the MAC in 615 */ 616int device_get_mac_address(struct device *dev, char *addr) 617{ 618 return fwnode_get_mac_address(dev_fwnode(dev), addr); 619} 620EXPORT_SYMBOL(device_get_mac_address); 621 622/** 623 * device_get_ethdev_address - Set netdev's MAC address from a given device 624 * @dev: Pointer to the device 625 * @netdev: Pointer to netdev to write the address to 626 * 627 * Wrapper around device_get_mac_address() which writes the address 628 * directly to netdev->dev_addr. 629 */ 630int device_get_ethdev_address(struct device *dev, struct net_device *netdev) 631{ 632 u8 addr[ETH_ALEN]; 633 int ret; 634 635 ret = device_get_mac_address(dev, addr); 636 if (!ret) 637 eth_hw_addr_set(netdev, addr); 638 return ret; 639} 640EXPORT_SYMBOL(device_get_ethdev_address); 641