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>
61 #include <linux/uaccess.h>
63 __setup("ether=", netdev_boot_setup);
66 * eth_header - create the Ethernet header
67 * @skb: buffer to alter
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)
75 * Set the protocol type. For a packet of type ETH_P_802_3/2 we put the length
78 int eth_header(struct sk_buff *skb, struct net_device *dev,
80 const void *daddr, const void *saddr, unsigned int len)
82 struct ethhdr *eth = (struct ethhdr *)skb_push(skb, ETH_HLEN);
84 if (type != ETH_P_802_3 && type != ETH_P_802_2)
85 eth->h_proto = htons(type);
87 eth->h_proto = htons(len);
90 * Set the source hardware address.
94 saddr = dev->dev_addr;
95 memcpy(eth->h_source, saddr, ETH_ALEN);
98 memcpy(eth->h_dest, daddr, ETH_ALEN);
103 * Anyway, the loopback-device should never use this function...
106 if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
107 memset(eth->h_dest, 0, ETH_ALEN);
113 EXPORT_SYMBOL(eth_header);
116 * eth_get_headlen - determine the the length of header for an ethernet frame
117 * @data: pointer to start of frame
118 * @len: total length of frame
120 * Make a best effort attempt to pull the length for all of the headers for
121 * a given frame in a linear buffer.
123 u32 eth_get_headlen(void *data, unsigned int len)
125 const struct ethhdr *eth = (const struct ethhdr *)data;
126 struct flow_keys keys;
128 /* this should never happen, but better safe than sorry */
129 if (len < sizeof(*eth))
132 /* parse any remaining L2/L3 headers, check for L4 */
133 if (!__skb_flow_dissect(NULL, &keys, data,
134 eth->h_proto, sizeof(*eth), len))
135 return max_t(u32, keys.thoff, sizeof(*eth));
137 /* parse for any L4 headers */
138 return min_t(u32, __skb_get_poff(NULL, data, &keys, len), len);
140 EXPORT_SYMBOL(eth_get_headlen);
143 * eth_type_trans - determine the packet's protocol ID.
144 * @skb: received socket data
145 * @dev: receiving network device
147 * The rule here is that we
148 * assume 802.3 if the type field is short enough to be a length.
149 * This is normal practice and works for any 'now in use' protocol.
151 __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev)
153 unsigned short _service_access_point;
154 const unsigned short *sap;
155 const struct ethhdr *eth;
158 skb_reset_mac_header(skb);
159 skb_pull_inline(skb, ETH_HLEN);
162 if (unlikely(is_multicast_ether_addr(eth->h_dest))) {
163 if (ether_addr_equal_64bits(eth->h_dest, dev->broadcast))
164 skb->pkt_type = PACKET_BROADCAST;
166 skb->pkt_type = PACKET_MULTICAST;
168 else if (unlikely(!ether_addr_equal_64bits(eth->h_dest,
170 skb->pkt_type = PACKET_OTHERHOST;
173 * Some variants of DSA tagging don't have an ethertype field
174 * at all, so we check here whether one of those tagging
175 * variants has been configured on the receiving interface,
176 * and if so, set skb->protocol without looking at the packet.
178 if (unlikely(netdev_uses_dsa(dev)))
179 return htons(ETH_P_XDSA);
181 if (likely(ntohs(eth->h_proto) >= ETH_P_802_3_MIN))
185 * This is a magic hack to spot IPX packets. Older Novell breaks
186 * the protocol design and runs IPX over 802.3 without an 802.2 LLC
187 * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
188 * won't work for fault tolerant netware but does for the rest.
190 sap = skb_header_pointer(skb, 0, sizeof(*sap), &_service_access_point);
191 if (sap && *sap == 0xFFFF)
192 return htons(ETH_P_802_3);
197 return htons(ETH_P_802_2);
199 EXPORT_SYMBOL(eth_type_trans);
202 * eth_header_parse - extract hardware address from packet
203 * @skb: packet to extract header from
204 * @haddr: destination buffer
206 int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr)
208 const struct ethhdr *eth = eth_hdr(skb);
209 memcpy(haddr, eth->h_source, ETH_ALEN);
212 EXPORT_SYMBOL(eth_header_parse);
215 * eth_header_cache - fill cache entry from neighbour
216 * @neigh: source neighbour
217 * @hh: destination cache entry
218 * @type: Ethernet type field
220 * Create an Ethernet header template from the neighbour.
222 int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, __be16 type)
225 const struct net_device *dev = neigh->dev;
227 eth = (struct ethhdr *)
228 (((u8 *) hh->hh_data) + (HH_DATA_OFF(sizeof(*eth))));
230 if (type == htons(ETH_P_802_3))
234 memcpy(eth->h_source, dev->dev_addr, ETH_ALEN);
235 memcpy(eth->h_dest, neigh->ha, ETH_ALEN);
236 hh->hh_len = ETH_HLEN;
239 EXPORT_SYMBOL(eth_header_cache);
242 * eth_header_cache_update - update cache entry
243 * @hh: destination cache entry
244 * @dev: network device
245 * @haddr: new hardware address
247 * Called by Address Resolution module to notify changes in address.
249 void eth_header_cache_update(struct hh_cache *hh,
250 const struct net_device *dev,
251 const unsigned char *haddr)
253 memcpy(((u8 *) hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)),
256 EXPORT_SYMBOL(eth_header_cache_update);
259 * eth_prepare_mac_addr_change - prepare for mac change
260 * @dev: network device
263 int eth_prepare_mac_addr_change(struct net_device *dev, void *p)
265 struct sockaddr *addr = p;
267 if (!(dev->priv_flags & IFF_LIVE_ADDR_CHANGE) && netif_running(dev))
269 if (!is_valid_ether_addr(addr->sa_data))
270 return -EADDRNOTAVAIL;
273 EXPORT_SYMBOL(eth_prepare_mac_addr_change);
276 * eth_commit_mac_addr_change - commit mac change
277 * @dev: network device
280 void eth_commit_mac_addr_change(struct net_device *dev, void *p)
282 struct sockaddr *addr = p;
284 memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
286 EXPORT_SYMBOL(eth_commit_mac_addr_change);
289 * eth_mac_addr - set new Ethernet hardware address
290 * @dev: network device
293 * Change hardware address of device.
295 * This doesn't change hardware matching, so needs to be overridden
296 * for most real devices.
298 int eth_mac_addr(struct net_device *dev, void *p)
302 ret = eth_prepare_mac_addr_change(dev, p);
305 eth_commit_mac_addr_change(dev, p);
308 EXPORT_SYMBOL(eth_mac_addr);
311 * eth_change_mtu - set new MTU size
312 * @dev: network device
313 * @new_mtu: new Maximum Transfer Unit
315 * Allow changing MTU size. Needs to be overridden for devices
316 * supporting jumbo frames.
318 int eth_change_mtu(struct net_device *dev, int new_mtu)
320 if (new_mtu < 68 || new_mtu > ETH_DATA_LEN)
325 EXPORT_SYMBOL(eth_change_mtu);
327 int eth_validate_addr(struct net_device *dev)
329 if (!is_valid_ether_addr(dev->dev_addr))
330 return -EADDRNOTAVAIL;
334 EXPORT_SYMBOL(eth_validate_addr);
336 const struct header_ops eth_header_ops ____cacheline_aligned = {
337 .create = eth_header,
338 .parse = eth_header_parse,
339 .cache = eth_header_cache,
340 .cache_update = eth_header_cache_update,
344 * ether_setup - setup Ethernet network device
345 * @dev: network device
347 * Fill in the fields of the device structure with Ethernet-generic values.
349 void ether_setup(struct net_device *dev)
351 dev->header_ops = ð_header_ops;
352 dev->type = ARPHRD_ETHER;
353 dev->hard_header_len = ETH_HLEN;
354 dev->mtu = ETH_DATA_LEN;
355 dev->addr_len = ETH_ALEN;
356 dev->tx_queue_len = 1000; /* Ethernet wants good queues */
357 dev->flags = IFF_BROADCAST|IFF_MULTICAST;
358 dev->priv_flags |= IFF_TX_SKB_SHARING;
360 memset(dev->broadcast, 0xFF, ETH_ALEN);
363 EXPORT_SYMBOL(ether_setup);
366 * alloc_etherdev_mqs - Allocates and sets up an Ethernet device
367 * @sizeof_priv: Size of additional driver-private structure to be allocated
368 * for this Ethernet device
369 * @txqs: The number of TX queues this device has.
370 * @rxqs: The number of RX queues this device has.
372 * Fill in the fields of the device structure with Ethernet-generic
373 * values. Basically does everything except registering the device.
375 * Constructs a new net device, complete with a private data area of
376 * size (sizeof_priv). A 32-byte (not bit) alignment is enforced for
377 * this private data area.
380 struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs,
383 return alloc_netdev_mqs(sizeof_priv, "eth%d", NET_NAME_UNKNOWN,
384 ether_setup, txqs, rxqs);
386 EXPORT_SYMBOL(alloc_etherdev_mqs);
388 ssize_t sysfs_format_mac(char *buf, const unsigned char *addr, int len)
390 return scnprintf(buf, PAGE_SIZE, "%*phC\n", len, addr);
392 EXPORT_SYMBOL(sysfs_format_mac);
394 struct sk_buff **eth_gro_receive(struct sk_buff **head,
397 struct sk_buff *p, **pp = NULL;
398 struct ethhdr *eh, *eh2;
399 unsigned int hlen, off_eth;
400 const struct packet_offload *ptype;
404 off_eth = skb_gro_offset(skb);
405 hlen = off_eth + sizeof(*eh);
406 eh = skb_gro_header_fast(skb, off_eth);
407 if (skb_gro_header_hard(skb, hlen)) {
408 eh = skb_gro_header_slow(skb, hlen, off_eth);
415 for (p = *head; p; p = p->next) {
416 if (!NAPI_GRO_CB(p)->same_flow)
419 eh2 = (struct ethhdr *)(p->data + off_eth);
420 if (compare_ether_header(eh, eh2)) {
421 NAPI_GRO_CB(p)->same_flow = 0;
429 ptype = gro_find_receive_by_type(type);
435 skb_gro_pull(skb, sizeof(*eh));
436 skb_gro_postpull_rcsum(skb, eh, sizeof(*eh));
437 pp = ptype->callbacks.gro_receive(head, skb);
442 NAPI_GRO_CB(skb)->flush |= flush;
446 EXPORT_SYMBOL(eth_gro_receive);
448 int eth_gro_complete(struct sk_buff *skb, int nhoff)
450 struct ethhdr *eh = (struct ethhdr *)(skb->data + nhoff);
451 __be16 type = eh->h_proto;
452 struct packet_offload *ptype;
455 if (skb->encapsulation)
456 skb_set_inner_mac_header(skb, nhoff);
459 ptype = gro_find_complete_by_type(type);
461 err = ptype->callbacks.gro_complete(skb, nhoff +
462 sizeof(struct ethhdr));
467 EXPORT_SYMBOL(eth_gro_complete);
469 static struct packet_offload eth_packet_offload __read_mostly = {
470 .type = cpu_to_be16(ETH_P_TEB),
472 .gro_receive = eth_gro_receive,
473 .gro_complete = eth_gro_complete,
477 static int __init eth_offload_init(void)
479 dev_add_offload(ð_packet_offload);
484 fs_initcall(eth_offload_init);