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>
60 #include <asm/uaccess.h>
61 #include <asm/system.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 we put the length
76 * in here instead. It is up to the 802.2 layer to carry protocol information.
78 int eth_header(struct sk_buff
*skb
, struct net_device
*dev
,
80 const void *daddr
, const void *saddr
, unsigned len
)
82 struct ethhdr
*eth
= (struct ethhdr
*)skb_push(skb
, ETH_HLEN
);
84 if (type
!= ETH_P_802_3
)
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_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
) {
132 case __constant_htons(ETH_P_IP
):
133 return arp_find(eth
->h_dest
, skb
);
137 "%s: unable to resolve type %X addresses.\n",
138 dev
->name
, (int)eth
->h_proto
);
140 memcpy(eth
->h_source
, dev
->dev_addr
, ETH_ALEN
);
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
)
163 skb_reset_mac_header(skb
);
164 skb_pull(skb
, ETH_HLEN
);
167 if (is_multicast_ether_addr(eth
->h_dest
)) {
168 if (!compare_ether_addr(eth
->h_dest
, dev
->broadcast
))
169 skb
->pkt_type
= PACKET_BROADCAST
;
171 skb
->pkt_type
= PACKET_MULTICAST
;
175 * This ALLMULTI check should be redundant by 1.4
176 * so don't forget to remove it.
178 * Seems, you forgot to remove it. All silly devices
179 * seems to set IFF_PROMISC.
182 else if (1 /*dev->flags&IFF_PROMISC */ ) {
183 if (unlikely(compare_ether_addr(eth
->h_dest
, dev
->dev_addr
)))
184 skb
->pkt_type
= PACKET_OTHERHOST
;
187 if (ntohs(eth
->h_proto
) >= 1536)
193 * This is a magic hack to spot IPX packets. Older Novell breaks
194 * the protocol design and runs IPX over 802.3 without an 802.2 LLC
195 * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
196 * won't work for fault tolerant netware but does for the rest.
198 if (*(unsigned short *)rawp
== 0xFFFF)
199 return htons(ETH_P_802_3
);
204 return htons(ETH_P_802_2
);
206 EXPORT_SYMBOL(eth_type_trans
);
209 * eth_header_parse - extract hardware address from packet
210 * @skb: packet to extract header from
211 * @haddr: destination buffer
213 int eth_header_parse(const struct sk_buff
*skb
, unsigned char *haddr
)
215 const struct ethhdr
*eth
= eth_hdr(skb
);
216 memcpy(haddr
, eth
->h_source
, ETH_ALEN
);
219 EXPORT_SYMBOL(eth_header_parse
);
222 * eth_header_cache - fill cache entry from neighbour
223 * @neigh: source neighbour
224 * @hh: destination cache entry
225 * Create an Ethernet header template from the neighbour.
227 int eth_header_cache(const struct neighbour
*neigh
, struct hh_cache
*hh
)
229 __be16 type
= hh
->hh_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
);
242 hh
->hh_len
= ETH_HLEN
;
245 EXPORT_SYMBOL(eth_header_cache
);
248 * eth_header_cache_update - update cache entry
249 * @hh: destination cache entry
250 * @dev: network device
251 * @haddr: new hardware address
253 * Called by Address Resolution module to notify changes in address.
255 void eth_header_cache_update(struct hh_cache
*hh
,
256 const struct net_device
*dev
,
257 const unsigned char *haddr
)
259 memcpy(((u8
*) hh
->hh_data
) + HH_DATA_OFF(sizeof(struct ethhdr
)),
262 EXPORT_SYMBOL(eth_header_cache_update
);
265 * eth_mac_addr - set new Ethernet hardware address
266 * @dev: network device
268 * Change hardware address of device.
270 * This doesn't change hardware matching, so needs to be overridden
271 * for most real devices.
273 static int eth_mac_addr(struct net_device
*dev
, void *p
)
275 struct sockaddr
*addr
= p
;
277 if (netif_running(dev
))
279 if (!is_valid_ether_addr(addr
->sa_data
))
280 return -EADDRNOTAVAIL
;
281 memcpy(dev
->dev_addr
, addr
->sa_data
, ETH_ALEN
);
286 * eth_change_mtu - set new MTU size
287 * @dev: network device
288 * @new_mtu: new Maximum Transfer Unit
290 * Allow changing MTU size. Needs to be overridden for devices
291 * supporting jumbo frames.
293 static int eth_change_mtu(struct net_device
*dev
, int new_mtu
)
295 if (new_mtu
< 68 || new_mtu
> ETH_DATA_LEN
)
301 static int eth_validate_addr(struct net_device
*dev
)
303 if (!is_valid_ether_addr(dev
->dev_addr
))
309 const struct header_ops eth_header_ops ____cacheline_aligned
= {
310 .create
= eth_header
,
311 .parse
= eth_header_parse
,
312 .rebuild
= eth_rebuild_header
,
313 .cache
= eth_header_cache
,
314 .cache_update
= eth_header_cache_update
,
318 * ether_setup - setup Ethernet network device
319 * @dev: network device
320 * Fill in the fields of the device structure with Ethernet-generic values.
322 void ether_setup(struct net_device
*dev
)
324 dev
->header_ops
= ð_header_ops
;
326 dev
->change_mtu
= eth_change_mtu
;
327 dev
->set_mac_address
= eth_mac_addr
;
328 dev
->validate_addr
= eth_validate_addr
;
330 dev
->type
= ARPHRD_ETHER
;
331 dev
->hard_header_len
= ETH_HLEN
;
332 dev
->mtu
= ETH_DATA_LEN
;
333 dev
->addr_len
= ETH_ALEN
;
334 dev
->tx_queue_len
= 1000; /* Ethernet wants good queues */
335 dev
->flags
= IFF_BROADCAST
|IFF_MULTICAST
;
337 memset(dev
->broadcast
, 0xFF, ETH_ALEN
);
340 EXPORT_SYMBOL(ether_setup
);
343 * alloc_etherdev_mq - Allocates and sets up an Ethernet device
344 * @sizeof_priv: Size of additional driver-private structure to be allocated
345 * for this Ethernet device
346 * @queue_count: The number of queues this device has.
348 * Fill in the fields of the device structure with Ethernet-generic
349 * values. Basically does everything except registering the device.
351 * Constructs a new net device, complete with a private data area of
352 * size (sizeof_priv). A 32-byte (not bit) alignment is enforced for
353 * this private data area.
356 struct net_device
*alloc_etherdev_mq(int sizeof_priv
, unsigned int queue_count
)
358 return alloc_netdev_mq(sizeof_priv
, "eth%d", ether_setup
, queue_count
);
360 EXPORT_SYMBOL(alloc_etherdev_mq
);
362 char *print_mac(char *buf
, const u8
*addr
)
364 sprintf(buf
, MAC_FMT
,
365 addr
[0], addr
[1], addr
[2], addr
[3], addr
[4], addr
[5]);
368 EXPORT_SYMBOL(print_mac
);