blob: c971f14712ec207608dd48d8477516bcb9af054b [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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.
5 *
6 * Ethernet-type device handling.
7 *
8 * Version: @(#)eth.c 1.0.7 05/25/93
9 *
Jesper Juhl02c30a82005-05-05 16:16:16 -070010 * Authors: Ross Biro
Linus Torvalds1da177e2005-04-16 15:20:36 -070011 * 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>
15 *
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().
34 *
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.
39 */
40#include <linux/module.h>
41#include <linux/types.h>
42#include <linux/kernel.h>
43#include <linux/sched.h>
44#include <linux/string.h>
45#include <linux/mm.h>
46#include <linux/socket.h>
47#include <linux/in.h>
48#include <linux/inet.h>
49#include <linux/ip.h>
50#include <linux/netdevice.h>
51#include <linux/etherdevice.h>
52#include <linux/skbuff.h>
53#include <linux/errno.h>
54#include <linux/config.h>
55#include <linux/init.h>
Kris Katterjohn46f25df2006-01-05 16:35:42 -080056#include <linux/if_ether.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070057#include <net/dst.h>
58#include <net/arp.h>
59#include <net/sock.h>
60#include <net/ipv6.h>
61#include <net/ip.h>
62#include <asm/uaccess.h>
63#include <asm/system.h>
64#include <asm/checksum.h>
65
Linus Torvalds1da177e2005-04-16 15:20:36 -070066__setup("ether=", netdev_boot_setup);
67
68/*
69 * Create the Ethernet MAC header for an arbitrary protocol layer
70 *
71 * saddr=NULL means use device source address
72 * daddr=NULL means leave destination address (eg unresolved arp)
73 */
74
75int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
76 void *daddr, void *saddr, unsigned len)
77{
78 struct ethhdr *eth = (struct ethhdr *)skb_push(skb,ETH_HLEN);
79
80 /*
81 * Set the protocol type. For a packet of type ETH_P_802_3 we put the length
82 * in here instead. It is up to the 802.2 layer to carry protocol information.
83 */
84
85 if(type!=ETH_P_802_3)
86 eth->h_proto = htons(type);
87 else
88 eth->h_proto = htons(len);
89
90 /*
91 * Set the source hardware address.
92 */
93
Denis Vlasenkoff593c52005-06-28 15:49:06 -070094 if(!saddr)
95 saddr = dev->dev_addr;
96 memcpy(eth->h_source,saddr,dev->addr_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
Jamal Hadi Salimf8d0e3f2006-02-23 16:18:01 -080098 if(daddr)
99 {
100 memcpy(eth->h_dest,daddr,dev->addr_len);
101 return ETH_HLEN;
102 }
103
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 /*
105 * Anyway, the loopback-device should never use this function...
106 */
107
108 if (dev->flags & (IFF_LOOPBACK|IFF_NOARP))
109 {
110 memset(eth->h_dest, 0, dev->addr_len);
111 return ETH_HLEN;
112 }
113
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 return -ETH_HLEN;
115}
116
117
118/*
119 * Rebuild the Ethernet MAC header. This is called after an ARP
120 * (or in future other address resolution) has completed on this
121 * sk_buff. We now let ARP fill in the other fields.
122 *
123 * This routine CANNOT use cached dst->neigh!
124 * Really, it is used only when dst->neigh is wrong.
125 */
126
127int eth_rebuild_header(struct sk_buff *skb)
128{
129 struct ethhdr *eth = (struct ethhdr *)skb->data;
130 struct net_device *dev = skb->dev;
131
132 switch (eth->h_proto)
133 {
134#ifdef CONFIG_INET
135 case __constant_htons(ETH_P_IP):
136 return arp_find(eth->h_dest, skb);
137#endif
138 default:
139 printk(KERN_DEBUG
140 "%s: unable to resolve type %X addresses.\n",
141 dev->name, (int)eth->h_proto);
142
143 memcpy(eth->h_source, dev->dev_addr, dev->addr_len);
144 break;
145 }
146
147 return 0;
148}
149
150
151/*
152 * Determine the packet's protocol ID. 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.
155 */
156
Alexey Dobriyanab611482005-07-12 12:08:43 -0700157__be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158{
159 struct ethhdr *eth;
160 unsigned char *rawp;
161
David S. Millerba645c12005-09-27 16:03:05 -0700162 skb->mac.raw = skb->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 skb_pull(skb,ETH_HLEN);
164 eth = eth_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
Kris Katterjohndbbc0982006-01-06 13:05:58 -0800166 if (is_multicast_ether_addr(eth->h_dest)) {
Stephen Hemminger360ac8e2005-10-25 15:03:41 -0700167 if (!compare_ether_addr(eth->h_dest, dev->broadcast))
David S. Millerba645c12005-09-27 16:03:05 -0700168 skb->pkt_type = PACKET_BROADCAST;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 else
David S. Millerba645c12005-09-27 16:03:05 -0700170 skb->pkt_type = PACKET_MULTICAST;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 }
172
173 /*
174 * This ALLMULTI check should be redundant by 1.4
175 * so don't forget to remove it.
176 *
177 * Seems, you forgot to remove it. All silly devices
178 * seems to set IFF_PROMISC.
179 */
180
David S. Millerba645c12005-09-27 16:03:05 -0700181 else if(1 /*dev->flags&IFF_PROMISC*/) {
Stephen Hemminger360ac8e2005-10-25 15:03:41 -0700182 if (unlikely(compare_ether_addr(eth->h_dest, dev->dev_addr)))
David S. Millerba645c12005-09-27 16:03:05 -0700183 skb->pkt_type = PACKET_OTHERHOST;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 }
185
186 if (ntohs(eth->h_proto) >= 1536)
187 return eth->h_proto;
188
189 rawp = skb->data;
190
191 /*
192 * This is a magic hack to spot IPX packets. Older Novell breaks
193 * the protocol design and runs IPX over 802.3 without an 802.2 LLC
194 * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
195 * won't work for fault tolerant netware but does for the rest.
196 */
197 if (*(unsigned short *)rawp == 0xFFFF)
198 return htons(ETH_P_802_3);
199
200 /*
201 * Real 802.2 LLC
202 */
203 return htons(ETH_P_802_2);
204}
205
206static int eth_header_parse(struct sk_buff *skb, unsigned char *haddr)
207{
208 struct ethhdr *eth = eth_hdr(skb);
209 memcpy(haddr, eth->h_source, ETH_ALEN);
210 return ETH_ALEN;
211}
212
213int eth_header_cache(struct neighbour *neigh, struct hh_cache *hh)
214{
215 unsigned short type = hh->hh_type;
216 struct ethhdr *eth;
217 struct net_device *dev = neigh->dev;
218
219 eth = (struct ethhdr*)
220 (((u8*)hh->hh_data) + (HH_DATA_OFF(sizeof(*eth))));
221
222 if (type == __constant_htons(ETH_P_802_3))
223 return -1;
224
225 eth->h_proto = type;
226 memcpy(eth->h_source, dev->dev_addr, dev->addr_len);
227 memcpy(eth->h_dest, neigh->ha, dev->addr_len);
228 hh->hh_len = ETH_HLEN;
229 return 0;
230}
231
232/*
233 * Called by Address Resolution module to notify changes in address.
234 */
235
236void eth_header_cache_update(struct hh_cache *hh, struct net_device *dev, unsigned char * haddr)
237{
238 memcpy(((u8*)hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)),
239 haddr, dev->addr_len);
240}
241
242EXPORT_SYMBOL(eth_type_trans);
243
244static int eth_mac_addr(struct net_device *dev, void *p)
245{
246 struct sockaddr *addr=p;
247 if (netif_running(dev))
248 return -EBUSY;
249 memcpy(dev->dev_addr, addr->sa_data,dev->addr_len);
250 return 0;
251}
252
253static int eth_change_mtu(struct net_device *dev, int new_mtu)
254{
Kris Katterjohn46f25df2006-01-05 16:35:42 -0800255 if (new_mtu < 68 || new_mtu > ETH_DATA_LEN)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 return -EINVAL;
257 dev->mtu = new_mtu;
258 return 0;
259}
260
261/*
262 * Fill in the fields of the device structure with ethernet-generic values.
263 */
264void ether_setup(struct net_device *dev)
265{
266 dev->change_mtu = eth_change_mtu;
267 dev->hard_header = eth_header;
268 dev->rebuild_header = eth_rebuild_header;
269 dev->set_mac_address = eth_mac_addr;
270 dev->hard_header_cache = eth_header_cache;
271 dev->header_cache_update= eth_header_cache_update;
272 dev->hard_header_parse = eth_header_parse;
273
274 dev->type = ARPHRD_ETHER;
275 dev->hard_header_len = ETH_HLEN;
Kris Katterjohn46f25df2006-01-05 16:35:42 -0800276 dev->mtu = ETH_DATA_LEN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 dev->addr_len = ETH_ALEN;
278 dev->tx_queue_len = 1000; /* Ethernet wants good queues */
279 dev->flags = IFF_BROADCAST|IFF_MULTICAST;
280
281 memset(dev->broadcast,0xFF, ETH_ALEN);
282
283}
284EXPORT_SYMBOL(ether_setup);
285
286/**
287 * alloc_etherdev - Allocates and sets up an ethernet device
288 * @sizeof_priv: Size of additional driver-private structure to be allocated
289 * for this ethernet device
290 *
291 * Fill in the fields of the device structure with ethernet-generic
292 * values. Basically does everything except registering the device.
293 *
294 * Constructs a new net device, complete with a private data area of
295 * size @sizeof_priv. A 32-byte (not bit) alignment is enforced for
296 * this private data area.
297 */
298
299struct net_device *alloc_etherdev(int sizeof_priv)
300{
301 return alloc_netdev(sizeof_priv, "eth%d", ether_setup);
302}
303EXPORT_SYMBOL(alloc_etherdev);