Linux 3.12.28
[linux/fpc-iii.git] / net / ethernet / eth.c
blobbe1f64d35358fbfbf61d84683c52e4d6fb423f34
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.
6 * Ethernet-type device handling.
8 * Version: @(#)eth.c 1.0.7 05/25/93
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>
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().
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>
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>
63 __setup("ether=", netdev_boot_setup);
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)
75 * Set the protocol type. For a packet of type ETH_P_802_3/2 we put the length
76 * in here instead.
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)
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);
86 else
87 eth->h_proto = htons(len);
90 * Set the source hardware address.
93 if (!saddr)
94 saddr = dev->dev_addr;
95 memcpy(eth->h_source, saddr, ETH_ALEN);
97 if (daddr) {
98 memcpy(eth->h_dest, daddr, ETH_ALEN);
99 return ETH_HLEN;
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);
108 return ETH_HLEN;
111 return -ETH_HLEN;
113 EXPORT_SYMBOL(eth_header);
116 * eth_rebuild_header- rebuild the Ethernet MAC header.
117 * @skb: socket buffer to update
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.
122 * This routine CANNOT use cached dst->neigh!
123 * Really, it is used only when dst->neigh is wrong.
125 int eth_rebuild_header(struct sk_buff *skb)
127 struct ethhdr *eth = (struct ethhdr *)skb->data;
128 struct net_device *dev = skb->dev;
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));
140 memcpy(eth->h_source, dev->dev_addr, ETH_ALEN);
141 break;
144 return 0;
146 EXPORT_SYMBOL(eth_rebuild_header);
149 * eth_type_trans - determine the packet's protocol ID.
150 * @skb: received socket data
151 * @dev: receiving network device
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.
157 __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev)
159 struct ethhdr *eth;
161 skb->dev = dev;
162 skb_reset_mac_header(skb);
163 skb_pull_inline(skb, ETH_HLEN);
164 eth = eth_hdr(skb);
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;
174 * This ALLMULTI check should be redundant by 1.4
175 * so don't forget to remove it.
177 * Seems, you forgot to remove it. All silly devices
178 * seems to set IFF_PROMISC.
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;
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.
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);
198 if (ntohs(eth->h_proto) >= ETH_P_802_3_MIN)
199 return eth->h_proto;
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.
207 if (skb->len >= 2 && *(unsigned short *)(skb->data) == 0xFFFF)
208 return htons(ETH_P_802_3);
211 * Real 802.2 LLC
213 return htons(ETH_P_802_2);
215 EXPORT_SYMBOL(eth_type_trans);
218 * eth_header_parse - extract hardware address from packet
219 * @skb: packet to extract header from
220 * @haddr: destination buffer
222 int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr)
224 const struct ethhdr *eth = eth_hdr(skb);
225 memcpy(haddr, eth->h_source, ETH_ALEN);
226 return ETH_ALEN;
228 EXPORT_SYMBOL(eth_header_parse);
231 * eth_header_cache - fill cache entry from neighbour
232 * @neigh: source neighbour
233 * @hh: destination cache entry
234 * @type: Ethernet type field
236 * Create an Ethernet header template from the neighbour.
238 int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, __be16 type)
240 struct ethhdr *eth;
241 const struct net_device *dev = neigh->dev;
243 eth = (struct ethhdr *)
244 (((u8 *) hh->hh_data) + (HH_DATA_OFF(sizeof(*eth))));
246 if (type == htons(ETH_P_802_3))
247 return -1;
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;
255 EXPORT_SYMBOL(eth_header_cache);
258 * eth_header_cache_update - update cache entry
259 * @hh: destination cache entry
260 * @dev: network device
261 * @haddr: new hardware address
263 * Called by Address Resolution module to notify changes in address.
265 void eth_header_cache_update(struct hh_cache *hh,
266 const struct net_device *dev,
267 const unsigned char *haddr)
269 memcpy(((u8 *) hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)),
270 haddr, ETH_ALEN);
272 EXPORT_SYMBOL(eth_header_cache_update);
275 * eth_prepare_mac_addr_change - prepare for mac change
276 * @dev: network device
277 * @p: socket address
279 int eth_prepare_mac_addr_change(struct net_device *dev, void *p)
281 struct sockaddr *addr = p;
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;
289 EXPORT_SYMBOL(eth_prepare_mac_addr_change);
292 * eth_commit_mac_addr_change - commit mac change
293 * @dev: network device
294 * @p: socket address
296 void eth_commit_mac_addr_change(struct net_device *dev, void *p)
298 struct sockaddr *addr = p;
300 memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
302 EXPORT_SYMBOL(eth_commit_mac_addr_change);
305 * eth_mac_addr - set new Ethernet hardware address
306 * @dev: network device
307 * @p: socket address
309 * Change hardware address of device.
311 * This doesn't change hardware matching, so needs to be overridden
312 * for most real devices.
314 int eth_mac_addr(struct net_device *dev, void *p)
316 int ret;
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;
324 EXPORT_SYMBOL(eth_mac_addr);
327 * eth_change_mtu - set new MTU size
328 * @dev: network device
329 * @new_mtu: new Maximum Transfer Unit
331 * Allow changing MTU size. Needs to be overridden for devices
332 * supporting jumbo frames.
334 int eth_change_mtu(struct net_device *dev, int new_mtu)
336 if (new_mtu < 68 || new_mtu > ETH_DATA_LEN)
337 return -EINVAL;
338 dev->mtu = new_mtu;
339 return 0;
341 EXPORT_SYMBOL(eth_change_mtu);
343 int eth_validate_addr(struct net_device *dev)
345 if (!is_valid_ether_addr(dev->dev_addr))
346 return -EADDRNOTAVAIL;
348 return 0;
350 EXPORT_SYMBOL(eth_validate_addr);
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,
361 * ether_setup - setup Ethernet network device
362 * @dev: network device
364 * Fill in the fields of the device structure with Ethernet-generic values.
366 void ether_setup(struct net_device *dev)
368 dev->header_ops = &eth_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;
377 memset(dev->broadcast, 0xFF, ETH_ALEN);
380 EXPORT_SYMBOL(ether_setup);
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.
389 * Fill in the fields of the device structure with Ethernet-generic
390 * values. Basically does everything except registering the device.
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.
397 struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs,
398 unsigned int rxqs)
400 return alloc_netdev_mqs(sizeof_priv, "eth%d", ether_setup, txqs, rxqs);
402 EXPORT_SYMBOL(alloc_etherdev_mqs);
404 ssize_t sysfs_format_mac(char *buf, const unsigned char *addr, int len)
406 return scnprintf(buf, PAGE_SIZE, "%*phC\n", len, addr);
408 EXPORT_SYMBOL(sysfs_format_mac);