blob: 6617ea47d3656a6b6c6cfa94e546c12dc9648f8e [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>
56#include <net/dst.h>
57#include <net/arp.h>
58#include <net/sock.h>
59#include <net/ipv6.h>
60#include <net/ip.h>
61#include <asm/uaccess.h>
62#include <asm/system.h>
63#include <asm/checksum.h>
64
65extern int __init netdev_boot_setup(char *str);
66
67__setup("ether=", netdev_boot_setup);
68
69/*
70 * Create the Ethernet MAC header for an arbitrary protocol layer
71 *
72 * saddr=NULL means use device source address
73 * daddr=NULL means leave destination address (eg unresolved arp)
74 */
75
76int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
77 void *daddr, void *saddr, unsigned len)
78{
79 struct ethhdr *eth = (struct ethhdr *)skb_push(skb,ETH_HLEN);
80
81 /*
82 * Set the protocol type. For a packet of type ETH_P_802_3 we put the length
83 * in here instead. It is up to the 802.2 layer to carry protocol information.
84 */
85
86 if(type!=ETH_P_802_3)
87 eth->h_proto = htons(type);
88 else
89 eth->h_proto = htons(len);
90
91 /*
92 * Set the source hardware address.
93 */
94
95 if(saddr)
96 memcpy(eth->h_source,saddr,dev->addr_len);
97 else
98 memcpy(eth->h_source,dev->dev_addr,dev->addr_len);
99
100 /*
101 * Anyway, the loopback-device should never use this function...
102 */
103
104 if (dev->flags & (IFF_LOOPBACK|IFF_NOARP))
105 {
106 memset(eth->h_dest, 0, dev->addr_len);
107 return ETH_HLEN;
108 }
109
110 if(daddr)
111 {
112 memcpy(eth->h_dest,daddr,dev->addr_len);
113 return ETH_HLEN;
114 }
115
116 return -ETH_HLEN;
117}
118
119
120/*
121 * Rebuild the Ethernet MAC header. This is called after an ARP
122 * (or in future other address resolution) has completed on this
123 * sk_buff. We now let ARP fill in the other fields.
124 *
125 * This routine CANNOT use cached dst->neigh!
126 * Really, it is used only when dst->neigh is wrong.
127 */
128
129int eth_rebuild_header(struct sk_buff *skb)
130{
131 struct ethhdr *eth = (struct ethhdr *)skb->data;
132 struct net_device *dev = skb->dev;
133
134 switch (eth->h_proto)
135 {
136#ifdef CONFIG_INET
137 case __constant_htons(ETH_P_IP):
138 return arp_find(eth->h_dest, skb);
139#endif
140 default:
141 printk(KERN_DEBUG
142 "%s: unable to resolve type %X addresses.\n",
143 dev->name, (int)eth->h_proto);
144
145 memcpy(eth->h_source, dev->dev_addr, dev->addr_len);
146 break;
147 }
148
149 return 0;
150}
151
152
153/*
154 * Determine the packet's protocol ID. 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.
157 */
158
159unsigned short eth_type_trans(struct sk_buff *skb, struct net_device *dev)
160{
161 struct ethhdr *eth;
162 unsigned char *rawp;
163
164 skb->mac.raw=skb->data;
165 skb_pull(skb,ETH_HLEN);
166 eth = eth_hdr(skb);
167 skb->input_dev = dev;
168
169 if(*eth->h_dest&1)
170 {
171 if(memcmp(eth->h_dest,dev->broadcast, ETH_ALEN)==0)
172 skb->pkt_type=PACKET_BROADCAST;
173 else
174 skb->pkt_type=PACKET_MULTICAST;
175 }
176
177 /*
178 * This ALLMULTI check should be redundant by 1.4
179 * so don't forget to remove it.
180 *
181 * Seems, you forgot to remove it. All silly devices
182 * seems to set IFF_PROMISC.
183 */
184
185 else if(1 /*dev->flags&IFF_PROMISC*/)
186 {
187 if(memcmp(eth->h_dest,dev->dev_addr, ETH_ALEN))
188 skb->pkt_type=PACKET_OTHERHOST;
189 }
190
191 if (ntohs(eth->h_proto) >= 1536)
192 return eth->h_proto;
193
194 rawp = skb->data;
195
196 /*
197 * This is a magic hack to spot IPX packets. Older Novell breaks
198 * the protocol design and runs IPX over 802.3 without an 802.2 LLC
199 * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
200 * won't work for fault tolerant netware but does for the rest.
201 */
202 if (*(unsigned short *)rawp == 0xFFFF)
203 return htons(ETH_P_802_3);
204
205 /*
206 * Real 802.2 LLC
207 */
208 return htons(ETH_P_802_2);
209}
210
211static int eth_header_parse(struct sk_buff *skb, unsigned char *haddr)
212{
213 struct ethhdr *eth = eth_hdr(skb);
214 memcpy(haddr, eth->h_source, ETH_ALEN);
215 return ETH_ALEN;
216}
217
218int eth_header_cache(struct neighbour *neigh, struct hh_cache *hh)
219{
220 unsigned short type = hh->hh_type;
221 struct ethhdr *eth;
222 struct net_device *dev = neigh->dev;
223
224 eth = (struct ethhdr*)
225 (((u8*)hh->hh_data) + (HH_DATA_OFF(sizeof(*eth))));
226
227 if (type == __constant_htons(ETH_P_802_3))
228 return -1;
229
230 eth->h_proto = type;
231 memcpy(eth->h_source, dev->dev_addr, dev->addr_len);
232 memcpy(eth->h_dest, neigh->ha, dev->addr_len);
233 hh->hh_len = ETH_HLEN;
234 return 0;
235}
236
237/*
238 * Called by Address Resolution module to notify changes in address.
239 */
240
241void eth_header_cache_update(struct hh_cache *hh, struct net_device *dev, unsigned char * haddr)
242{
243 memcpy(((u8*)hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)),
244 haddr, dev->addr_len);
245}
246
247EXPORT_SYMBOL(eth_type_trans);
248
249static int eth_mac_addr(struct net_device *dev, void *p)
250{
251 struct sockaddr *addr=p;
252 if (netif_running(dev))
253 return -EBUSY;
254 memcpy(dev->dev_addr, addr->sa_data,dev->addr_len);
255 return 0;
256}
257
258static int eth_change_mtu(struct net_device *dev, int new_mtu)
259{
260 if ((new_mtu < 68) || (new_mtu > 1500))
261 return -EINVAL;
262 dev->mtu = new_mtu;
263 return 0;
264}
265
266/*
267 * Fill in the fields of the device structure with ethernet-generic values.
268 */
269void ether_setup(struct net_device *dev)
270{
271 dev->change_mtu = eth_change_mtu;
272 dev->hard_header = eth_header;
273 dev->rebuild_header = eth_rebuild_header;
274 dev->set_mac_address = eth_mac_addr;
275 dev->hard_header_cache = eth_header_cache;
276 dev->header_cache_update= eth_header_cache_update;
277 dev->hard_header_parse = eth_header_parse;
278
279 dev->type = ARPHRD_ETHER;
280 dev->hard_header_len = ETH_HLEN;
281 dev->mtu = 1500; /* eth_mtu */
282 dev->addr_len = ETH_ALEN;
283 dev->tx_queue_len = 1000; /* Ethernet wants good queues */
284 dev->flags = IFF_BROADCAST|IFF_MULTICAST;
285
286 memset(dev->broadcast,0xFF, ETH_ALEN);
287
288}
289EXPORT_SYMBOL(ether_setup);
290
291/**
292 * alloc_etherdev - Allocates and sets up an ethernet device
293 * @sizeof_priv: Size of additional driver-private structure to be allocated
294 * for this ethernet device
295 *
296 * Fill in the fields of the device structure with ethernet-generic
297 * values. Basically does everything except registering the device.
298 *
299 * Constructs a new net device, complete with a private data area of
300 * size @sizeof_priv. A 32-byte (not bit) alignment is enforced for
301 * this private data area.
302 */
303
304struct net_device *alloc_etherdev(int sizeof_priv)
305{
306 return alloc_netdev(sizeof_priv, "eth%d", ether_setup);
307}
308EXPORT_SYMBOL(alloc_etherdev);