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.
6 * Ethernet-type device handling.
8 * Version: @(#)eth.c 1.0.7 05/25/93
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>
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
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().
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.
40 #include <linux/module.h>
41 #include <linux/types.h>
42 #include <linux/kernel.h>
43 #include <linux/string.h>
45 #include <linux/socket.h>
47 #include <linux/inet.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 <linux/of_net.h>
56 #include <linux/pci.h>
63 #include <net/flow_dissector.h>
64 #include <linux/uaccess.h>
65 #include <net/pkt_sched.h>
67 __setup("ether=", netdev_boot_setup);
70 * eth_header - create the Ethernet header
71 * @skb: buffer to alter
73 * @type: Ethernet type field
74 * @daddr: destination address (NULL leave destination address)
75 * @saddr: source address (NULL use device source address)
76 * @len: packet length (<= skb->len)
79 * Set the protocol type. For a packet of type ETH_P_802_3/2 we put the length
82 int eth_header(struct sk_buff *skb, struct net_device *dev,
84 const void *daddr, const void *saddr, unsigned int len)
86 struct ethhdr *eth = skb_push(skb, ETH_HLEN);
88 if (type != ETH_P_802_3 && type != ETH_P_802_2)
89 eth->h_proto = htons(type);
91 eth->h_proto = htons(len);
94 * Set the source hardware address.
98 saddr = dev->dev_addr;
99 memcpy(eth->h_source, saddr, ETH_ALEN);
102 memcpy(eth->h_dest, daddr, ETH_ALEN);
107 * Anyway, the loopback-device should never use this function...
110 if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
111 eth_zero_addr(eth->h_dest);
117 EXPORT_SYMBOL(eth_header);
120 * eth_get_headlen - determine the length of header for an ethernet frame
121 * @data: pointer to start of frame
122 * @len: total length of frame
124 * Make a best effort attempt to pull the length for all of the headers for
125 * a given frame in a linear buffer.
127 u32 eth_get_headlen(void *data, unsigned int len)
129 const unsigned int flags = FLOW_DISSECTOR_F_PARSE_1ST_FRAG;
130 const struct ethhdr *eth = (const struct ethhdr *)data;
131 struct flow_keys keys;
133 /* this should never happen, but better safe than sorry */
134 if (unlikely(len < sizeof(*eth)))
137 /* parse any remaining L2/L3 headers, check for L4 */
138 if (!skb_flow_dissect_flow_keys_buf(&keys, data, eth->h_proto,
139 sizeof(*eth), len, flags))
140 return max_t(u32, keys.control.thoff, sizeof(*eth));
142 /* parse for any L4 headers */
143 return min_t(u32, __skb_get_poff(NULL, data, &keys, len), len);
145 EXPORT_SYMBOL(eth_get_headlen);
148 * eth_type_trans - determine the packet's protocol ID.
149 * @skb: received socket data
150 * @dev: receiving network device
152 * The rule here is that we
153 * assume 802.3 if the type field is short enough to be a length.
154 * This is normal practice and works for any 'now in use' protocol.
156 __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev)
158 unsigned short _service_access_point;
159 const unsigned short *sap;
160 const struct ethhdr *eth;
163 skb_reset_mac_header(skb);
165 eth = (struct ethhdr *)skb->data;
166 skb_pull_inline(skb, ETH_HLEN);
168 if (unlikely(is_multicast_ether_addr_64bits(eth->h_dest))) {
169 if (ether_addr_equal_64bits(eth->h_dest, dev->broadcast))
170 skb->pkt_type = PACKET_BROADCAST;
172 skb->pkt_type = PACKET_MULTICAST;
174 else if (unlikely(!ether_addr_equal_64bits(eth->h_dest,
176 skb->pkt_type = PACKET_OTHERHOST;
179 * Some variants of DSA tagging don't have an ethertype field
180 * at all, so we check here whether one of those tagging
181 * variants has been configured on the receiving interface,
182 * and if so, set skb->protocol without looking at the packet.
184 if (unlikely(netdev_uses_dsa(dev)))
185 return htons(ETH_P_XDSA);
187 if (likely(eth_proto_is_802_3(eth->h_proto)))
191 * This is a magic hack to spot IPX packets. Older Novell breaks
192 * the protocol design and runs IPX over 802.3 without an 802.2 LLC
193 * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
194 * won't work for fault tolerant netware but does for the rest.
196 sap = skb_header_pointer(skb, 0, sizeof(*sap), &_service_access_point);
197 if (sap && *sap == 0xFFFF)
198 return htons(ETH_P_802_3);
203 return htons(ETH_P_802_2);
205 EXPORT_SYMBOL(eth_type_trans);
208 * eth_header_parse - extract hardware address from packet
209 * @skb: packet to extract header from
210 * @haddr: destination buffer
212 int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr)
214 const struct ethhdr *eth = eth_hdr(skb);
215 memcpy(haddr, eth->h_source, ETH_ALEN);
218 EXPORT_SYMBOL(eth_header_parse);
221 * eth_header_cache - fill cache entry from neighbour
222 * @neigh: source neighbour
223 * @hh: destination cache entry
224 * @type: Ethernet type field
226 * Create an Ethernet header template from the neighbour.
228 int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, __be16 type)
231 const struct net_device *dev = neigh->dev;
233 eth = (struct ethhdr *)
234 (((u8 *) hh->hh_data) + (HH_DATA_OFF(sizeof(*eth))));
236 if (type == htons(ETH_P_802_3))
240 memcpy(eth->h_source, dev->dev_addr, ETH_ALEN);
241 memcpy(eth->h_dest, neigh->ha, ETH_ALEN);
243 /* Pairs with READ_ONCE() in neigh_resolve_output(),
244 * neigh_hh_output() and neigh_update_hhs().
246 smp_store_release(&hh->hh_len, ETH_HLEN);
250 EXPORT_SYMBOL(eth_header_cache);
253 * eth_header_cache_update - update cache entry
254 * @hh: destination cache entry
255 * @dev: network device
256 * @haddr: new hardware address
258 * Called by Address Resolution module to notify changes in address.
260 void eth_header_cache_update(struct hh_cache *hh,
261 const struct net_device *dev,
262 const unsigned char *haddr)
264 memcpy(((u8 *) hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)),
267 EXPORT_SYMBOL(eth_header_cache_update);
270 * eth_prepare_mac_addr_change - prepare for mac change
271 * @dev: network device
274 int eth_prepare_mac_addr_change(struct net_device *dev, void *p)
276 struct sockaddr *addr = p;
278 if (!(dev->priv_flags & IFF_LIVE_ADDR_CHANGE) && netif_running(dev))
280 if (!is_valid_ether_addr(addr->sa_data))
281 return -EADDRNOTAVAIL;
284 EXPORT_SYMBOL(eth_prepare_mac_addr_change);
287 * eth_commit_mac_addr_change - commit mac change
288 * @dev: network device
291 void eth_commit_mac_addr_change(struct net_device *dev, void *p)
293 struct sockaddr *addr = p;
295 memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
297 EXPORT_SYMBOL(eth_commit_mac_addr_change);
300 * eth_mac_addr - set new Ethernet hardware address
301 * @dev: network device
304 * Change hardware address of device.
306 * This doesn't change hardware matching, so needs to be overridden
307 * for most real devices.
309 int eth_mac_addr(struct net_device *dev, void *p)
313 ret = eth_prepare_mac_addr_change(dev, p);
316 eth_commit_mac_addr_change(dev, p);
319 EXPORT_SYMBOL(eth_mac_addr);
322 * eth_change_mtu - set new MTU size
323 * @dev: network device
324 * @new_mtu: new Maximum Transfer Unit
326 * Allow changing MTU size. Needs to be overridden for devices
327 * supporting jumbo frames.
329 int eth_change_mtu(struct net_device *dev, int new_mtu)
331 netdev_warn(dev, "%s is deprecated\n", __func__);
335 EXPORT_SYMBOL(eth_change_mtu);
337 int eth_validate_addr(struct net_device *dev)
339 if (!is_valid_ether_addr(dev->dev_addr))
340 return -EADDRNOTAVAIL;
344 EXPORT_SYMBOL(eth_validate_addr);
346 const struct header_ops eth_header_ops ____cacheline_aligned = {
347 .create = eth_header,
348 .parse = eth_header_parse,
349 .cache = eth_header_cache,
350 .cache_update = eth_header_cache_update,
354 * ether_setup - setup Ethernet network device
355 * @dev: network device
357 * Fill in the fields of the device structure with Ethernet-generic values.
359 void ether_setup(struct net_device *dev)
361 dev->header_ops = ð_header_ops;
362 dev->type = ARPHRD_ETHER;
363 dev->hard_header_len = ETH_HLEN;
364 dev->min_header_len = ETH_HLEN;
365 dev->mtu = ETH_DATA_LEN;
366 dev->min_mtu = ETH_MIN_MTU;
367 dev->max_mtu = ETH_DATA_LEN;
368 dev->addr_len = ETH_ALEN;
369 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
370 dev->flags = IFF_BROADCAST|IFF_MULTICAST;
371 dev->priv_flags |= IFF_TX_SKB_SHARING;
373 eth_broadcast_addr(dev->broadcast);
376 EXPORT_SYMBOL(ether_setup);
379 * alloc_etherdev_mqs - Allocates and sets up an Ethernet device
380 * @sizeof_priv: Size of additional driver-private structure to be allocated
381 * for this Ethernet device
382 * @txqs: The number of TX queues this device has.
383 * @rxqs: The number of RX queues this device has.
385 * Fill in the fields of the device structure with Ethernet-generic
386 * values. Basically does everything except registering the device.
388 * Constructs a new net device, complete with a private data area of
389 * size (sizeof_priv). A 32-byte (not bit) alignment is enforced for
390 * this private data area.
393 struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs,
396 return alloc_netdev_mqs(sizeof_priv, "eth%d", NET_NAME_UNKNOWN,
397 ether_setup, txqs, rxqs);
399 EXPORT_SYMBOL(alloc_etherdev_mqs);
401 static void devm_free_netdev(struct device *dev, void *res)
403 free_netdev(*(struct net_device **)res);
406 struct net_device *devm_alloc_etherdev_mqs(struct device *dev, int sizeof_priv,
407 unsigned int txqs, unsigned int rxqs)
409 struct net_device **dr;
410 struct net_device *netdev;
412 dr = devres_alloc(devm_free_netdev, sizeof(*dr), GFP_KERNEL);
416 netdev = alloc_etherdev_mqs(sizeof_priv, txqs, rxqs);
427 EXPORT_SYMBOL(devm_alloc_etherdev_mqs);
429 ssize_t sysfs_format_mac(char *buf, const unsigned char *addr, int len)
431 return scnprintf(buf, PAGE_SIZE, "%*phC\n", len, addr);
433 EXPORT_SYMBOL(sysfs_format_mac);
435 struct sk_buff **eth_gro_receive(struct sk_buff **head,
438 struct sk_buff *p, **pp = NULL;
439 struct ethhdr *eh, *eh2;
440 unsigned int hlen, off_eth;
441 const struct packet_offload *ptype;
445 off_eth = skb_gro_offset(skb);
446 hlen = off_eth + sizeof(*eh);
447 eh = skb_gro_header_fast(skb, off_eth);
448 if (skb_gro_header_hard(skb, hlen)) {
449 eh = skb_gro_header_slow(skb, hlen, off_eth);
456 for (p = *head; p; p = p->next) {
457 if (!NAPI_GRO_CB(p)->same_flow)
460 eh2 = (struct ethhdr *)(p->data + off_eth);
461 if (compare_ether_header(eh, eh2)) {
462 NAPI_GRO_CB(p)->same_flow = 0;
470 ptype = gro_find_receive_by_type(type);
476 skb_gro_pull(skb, sizeof(*eh));
477 skb_gro_postpull_rcsum(skb, eh, sizeof(*eh));
478 pp = call_gro_receive(ptype->callbacks.gro_receive, head, skb);
483 skb_gro_flush_final(skb, pp, flush);
487 EXPORT_SYMBOL(eth_gro_receive);
489 int eth_gro_complete(struct sk_buff *skb, int nhoff)
491 struct ethhdr *eh = (struct ethhdr *)(skb->data + nhoff);
492 __be16 type = eh->h_proto;
493 struct packet_offload *ptype;
496 if (skb->encapsulation)
497 skb_set_inner_mac_header(skb, nhoff);
500 ptype = gro_find_complete_by_type(type);
502 err = ptype->callbacks.gro_complete(skb, nhoff +
503 sizeof(struct ethhdr));
508 EXPORT_SYMBOL(eth_gro_complete);
510 static struct packet_offload eth_packet_offload __read_mostly = {
511 .type = cpu_to_be16(ETH_P_TEB),
514 .gro_receive = eth_gro_receive,
515 .gro_complete = eth_gro_complete,
519 static int __init eth_offload_init(void)
521 dev_add_offload(ð_packet_offload);
526 fs_initcall(eth_offload_init);
528 unsigned char * __weak arch_get_platform_mac_address(void)
533 int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr)
535 const unsigned char *addr;
536 struct device_node *dp;
539 dp = pci_device_to_OF_node(to_pci_dev(dev));
545 addr = of_get_mac_address(dp);
547 addr = arch_get_platform_mac_address();
552 ether_addr_copy(mac_addr, addr);
555 EXPORT_SYMBOL(eth_platform_get_mac_address);