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 <asm/uaccess.h>
62 #include <asm/system.h>
64 __setup("ether=", netdev_boot_setup
);
67 * eth_header - create the Ethernet header
68 * @skb: buffer to alter
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)
76 * Set the protocol type. For a packet of type ETH_P_802_3/2 we put the length
79 int eth_header(struct sk_buff
*skb
, struct net_device
*dev
,
81 const void *daddr
, const void *saddr
, unsigned len
)
83 struct ethhdr
*eth
= (struct ethhdr
*)skb_push(skb
, ETH_HLEN
);
85 if (type
!= ETH_P_802_3
&& type
!= ETH_P_802_2
)
86 eth
->h_proto
= htons(type
);
88 eth
->h_proto
= htons(len
);
91 * Set the source hardware address.
95 saddr
= dev
->dev_addr
;
96 memcpy(eth
->h_source
, saddr
, ETH_ALEN
);
99 memcpy(eth
->h_dest
, daddr
, ETH_ALEN
);
104 * Anyway, the loopback-device should never use this function...
107 if (dev
->flags
& (IFF_LOOPBACK
| IFF_NOARP
)) {
108 memset(eth
->h_dest
, 0, ETH_ALEN
);
114 EXPORT_SYMBOL(eth_header
);
117 * eth_rebuild_header- rebuild the Ethernet MAC header.
118 * @skb: socket buffer to update
120 * This is called after an ARP or IPV6 ndisc it's resolution on this
121 * sk_buff. We now let protocol (ARP) fill in the other fields.
123 * This routine CANNOT use cached dst->neigh!
124 * Really, it is used only when dst->neigh is wrong.
126 int eth_rebuild_header(struct sk_buff
*skb
)
128 struct ethhdr
*eth
= (struct ethhdr
*)skb
->data
;
129 struct net_device
*dev
= skb
->dev
;
131 switch (eth
->h_proto
) {
133 case htons(ETH_P_IP
):
134 return arp_find(eth
->h_dest
, skb
);
138 "%s: unable to resolve type %X addresses.\n",
139 dev
->name
, ntohs(eth
->h_proto
));
141 memcpy(eth
->h_source
, dev
->dev_addr
, ETH_ALEN
);
147 EXPORT_SYMBOL(eth_rebuild_header
);
150 * eth_type_trans - determine the packet's protocol ID.
151 * @skb: received socket data
152 * @dev: receiving network device
154 * The rule here is that we
155 * assume 802.3 if the type field is short enough to be a length.
156 * This is normal practice and works for any 'now in use' protocol.
158 __be16
eth_type_trans(struct sk_buff
*skb
, struct net_device
*dev
)
163 skb_reset_mac_header(skb
);
164 skb_pull_inline(skb
, ETH_HLEN
);
167 if (unlikely(is_multicast_ether_addr(eth
->h_dest
))) {
168 if (!compare_ether_addr_64bits(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_64bits(eth
->h_dest
, 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
) >= 1536)
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
);
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
);
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
235 * Create an Ethernet header template from the neighbour.
237 int eth_header_cache(const struct neighbour
*neigh
, struct hh_cache
*hh
, __be16 type
)
240 const struct net_device
*dev
= neigh
->dev
;
242 eth
= (struct ethhdr
*)
243 (((u8
*) hh
->hh_data
) + (HH_DATA_OFF(sizeof(*eth
))));
245 if (type
== htons(ETH_P_802_3
))
249 memcpy(eth
->h_source
, dev
->dev_addr
, ETH_ALEN
);
250 memcpy(eth
->h_dest
, neigh
->ha
, ETH_ALEN
);
251 hh
->hh_len
= ETH_HLEN
;
254 EXPORT_SYMBOL(eth_header_cache
);
257 * eth_header_cache_update - update cache entry
258 * @hh: destination cache entry
259 * @dev: network device
260 * @haddr: new hardware address
262 * Called by Address Resolution module to notify changes in address.
264 void eth_header_cache_update(struct hh_cache
*hh
,
265 const struct net_device
*dev
,
266 const unsigned char *haddr
)
268 memcpy(((u8
*) hh
->hh_data
) + HH_DATA_OFF(sizeof(struct ethhdr
)),
271 EXPORT_SYMBOL(eth_header_cache_update
);
274 * eth_mac_addr - set new Ethernet hardware address
275 * @dev: network device
277 * Change hardware address of device.
279 * This doesn't change hardware matching, so needs to be overridden
280 * for most real devices.
282 int eth_mac_addr(struct net_device
*dev
, void *p
)
284 struct sockaddr
*addr
= p
;
286 if (netif_running(dev
))
288 if (!is_valid_ether_addr(addr
->sa_data
))
289 return -EADDRNOTAVAIL
;
290 memcpy(dev
->dev_addr
, addr
->sa_data
, ETH_ALEN
);
293 EXPORT_SYMBOL(eth_mac_addr
);
296 * eth_change_mtu - set new MTU size
297 * @dev: network device
298 * @new_mtu: new Maximum Transfer Unit
300 * Allow changing MTU size. Needs to be overridden for devices
301 * supporting jumbo frames.
303 int eth_change_mtu(struct net_device
*dev
, int new_mtu
)
305 if (new_mtu
< 68 || new_mtu
> ETH_DATA_LEN
)
310 EXPORT_SYMBOL(eth_change_mtu
);
312 int eth_validate_addr(struct net_device
*dev
)
314 if (!is_valid_ether_addr(dev
->dev_addr
))
315 return -EADDRNOTAVAIL
;
319 EXPORT_SYMBOL(eth_validate_addr
);
321 const struct header_ops eth_header_ops ____cacheline_aligned
= {
322 .create
= eth_header
,
323 .parse
= eth_header_parse
,
324 .rebuild
= eth_rebuild_header
,
325 .cache
= eth_header_cache
,
326 .cache_update
= eth_header_cache_update
,
330 * ether_setup - setup Ethernet network device
331 * @dev: network device
332 * Fill in the fields of the device structure with Ethernet-generic values.
334 void ether_setup(struct net_device
*dev
)
336 dev
->header_ops
= ð_header_ops
;
337 dev
->type
= ARPHRD_ETHER
;
338 dev
->hard_header_len
= ETH_HLEN
;
339 dev
->mtu
= ETH_DATA_LEN
;
340 dev
->addr_len
= ETH_ALEN
;
341 dev
->tx_queue_len
= 1000; /* Ethernet wants good queues */
342 dev
->flags
= IFF_BROADCAST
|IFF_MULTICAST
;
343 dev
->priv_flags
= IFF_TX_SKB_SHARING
;
345 memset(dev
->broadcast
, 0xFF, ETH_ALEN
);
348 EXPORT_SYMBOL(ether_setup
);
351 * alloc_etherdev_mqs - Allocates and sets up an Ethernet device
352 * @sizeof_priv: Size of additional driver-private structure to be allocated
353 * for this Ethernet device
354 * @txqs: The number of TX queues this device has.
355 * @rxqs: The number of RX queues this device has.
357 * Fill in the fields of the device structure with Ethernet-generic
358 * values. Basically does everything except registering the device.
360 * Constructs a new net device, complete with a private data area of
361 * size (sizeof_priv). A 32-byte (not bit) alignment is enforced for
362 * this private data area.
365 struct net_device
*alloc_etherdev_mqs(int sizeof_priv
, unsigned int txqs
,
368 return alloc_netdev_mqs(sizeof_priv
, "eth%d", ether_setup
, txqs
, rxqs
);
370 EXPORT_SYMBOL(alloc_etherdev_mqs
);
372 static size_t _format_mac_addr(char *buf
, int buflen
,
373 const unsigned char *addr
, int len
)
378 for (i
= 0; i
< len
; i
++) {
379 cp
+= scnprintf(cp
, buflen
- (cp
- buf
), "%02x", addr
[i
]);
382 cp
+= scnprintf(cp
, buflen
- (cp
- buf
), ":");
387 ssize_t
sysfs_format_mac(char *buf
, const unsigned char *addr
, int len
)
391 l
= _format_mac_addr(buf
, PAGE_SIZE
, addr
, len
);
392 l
+= scnprintf(buf
+ l
, PAGE_SIZE
- l
, "\n");
395 EXPORT_SYMBOL(sysfs_format_mac
);