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1da177e4 LT |
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. | |
5 | * | |
6 | * Ethernet-type device handling. | |
7 | * | |
8 | * Version: @(#)eth.c 1.0.7 05/25/93 | |
9 | * | |
02c30a84 | 10 | * Authors: Ross Biro |
1da177e4 LT |
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> | |
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> | |
1da177e4 | 54 | #include <linux/init.h> |
46f25dff | 55 | #include <linux/if_ether.h> |
1da177e4 LT |
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 | ||
1da177e4 LT |
65 | __setup("ether=", netdev_boot_setup); |
66 | ||
d3e01f71 SH |
67 | /** |
68 | * eth_header - create the Ethernet header | |
69 | * @skb: buffer to alter | |
70 | * @dev: source device | |
71 | * @type: Ethernet type field | |
72 | * @daddr: destination address (NULL leave destination address) | |
73 | * @saddr: source address (NULL use device source address) | |
74 | * @len: packet length (<= skb->len) | |
1da177e4 | 75 | * |
d3e01f71 SH |
76 | * |
77 | * Set the protocol type. For a packet of type ETH_P_802_3 we put the length | |
78 | * in here instead. It is up to the 802.2 layer to carry protocol information. | |
1da177e4 | 79 | */ |
1da177e4 LT |
80 | int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, |
81 | void *daddr, void *saddr, unsigned len) | |
82 | { | |
83 | struct ethhdr *eth = (struct ethhdr *)skb_push(skb,ETH_HLEN); | |
84 | ||
1da177e4 LT |
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 | ||
ff593c59 DV |
94 | if(!saddr) |
95 | saddr = dev->dev_addr; | |
96 | memcpy(eth->h_source,saddr,dev->addr_len); | |
1da177e4 | 97 | |
f8d0e3f1 JHS |
98 | if(daddr) |
99 | { | |
100 | memcpy(eth->h_dest,daddr,dev->addr_len); | |
101 | return ETH_HLEN; | |
102 | } | |
103 | ||
1da177e4 LT |
104 | /* |
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 | ||
1da177e4 LT |
114 | return -ETH_HLEN; |
115 | } | |
116 | ||
d3e01f71 SH |
117 | /** |
118 | * eth_rebuild_header- rebuild the Ethernet MAC header. | |
119 | * @skb: socket buffer to update | |
120 | * | |
121 | * This is called after an ARP or IPV6 ndisc it's resolution on this | |
122 | * sk_buff. We now let protocol (ARP) fill in the other fields. | |
1da177e4 | 123 | * |
d3e01f71 SH |
124 | * This routine CANNOT use cached dst->neigh! |
125 | * Really, it is used only when dst->neigh is wrong. | |
1da177e4 | 126 | */ |
1da177e4 LT |
127 | int 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 | ||
d3e01f71 SH |
151 | /** |
152 | * eth_type_trans - determine the packet's protocol ID. | |
153 | * @skb: received socket data | |
154 | * @dev: receiving network device | |
155 | * | |
156 | * The rule here is that we | |
157 | * assume 802.3 if the type field is short enough to be a length. | |
158 | * This is normal practice and works for any 'now in use' protocol. | |
1da177e4 | 159 | */ |
ab611487 | 160 | __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev) |
1da177e4 LT |
161 | { |
162 | struct ethhdr *eth; | |
163 | unsigned char *rawp; | |
164 | ||
ba645c16 | 165 | skb->mac.raw = skb->data; |
1da177e4 LT |
166 | skb_pull(skb,ETH_HLEN); |
167 | eth = eth_hdr(skb); | |
1da177e4 | 168 | |
dbbc0988 | 169 | if (is_multicast_ether_addr(eth->h_dest)) { |
360ac8e2 | 170 | if (!compare_ether_addr(eth->h_dest, dev->broadcast)) |
ba645c16 | 171 | skb->pkt_type = PACKET_BROADCAST; |
1da177e4 | 172 | else |
ba645c16 | 173 | skb->pkt_type = PACKET_MULTICAST; |
1da177e4 LT |
174 | } |
175 | ||
176 | /* | |
177 | * This ALLMULTI check should be redundant by 1.4 | |
178 | * so don't forget to remove it. | |
179 | * | |
180 | * Seems, you forgot to remove it. All silly devices | |
181 | * seems to set IFF_PROMISC. | |
182 | */ | |
183 | ||
ba645c16 | 184 | else if(1 /*dev->flags&IFF_PROMISC*/) { |
360ac8e2 | 185 | if (unlikely(compare_ether_addr(eth->h_dest, dev->dev_addr))) |
ba645c16 | 186 | skb->pkt_type = PACKET_OTHERHOST; |
1da177e4 LT |
187 | } |
188 | ||
189 | if (ntohs(eth->h_proto) >= 1536) | |
190 | return eth->h_proto; | |
191 | ||
192 | rawp = skb->data; | |
193 | ||
194 | /* | |
195 | * This is a magic hack to spot IPX packets. Older Novell breaks | |
196 | * the protocol design and runs IPX over 802.3 without an 802.2 LLC | |
197 | * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This | |
198 | * won't work for fault tolerant netware but does for the rest. | |
199 | */ | |
200 | if (*(unsigned short *)rawp == 0xFFFF) | |
201 | return htons(ETH_P_802_3); | |
202 | ||
203 | /* | |
204 | * Real 802.2 LLC | |
205 | */ | |
206 | return htons(ETH_P_802_2); | |
207 | } | |
208 | ||
d3e01f71 SH |
209 | /** |
210 | * eth_header_parse - extract hardware address from packet | |
211 | * @skb: packet to extract header from | |
212 | * @haddr: destination buffer | |
213 | */ | |
1da177e4 LT |
214 | static int eth_header_parse(struct sk_buff *skb, unsigned char *haddr) |
215 | { | |
216 | struct ethhdr *eth = eth_hdr(skb); | |
217 | memcpy(haddr, eth->h_source, ETH_ALEN); | |
218 | return ETH_ALEN; | |
219 | } | |
220 | ||
d3e01f71 SH |
221 | /** |
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. | |
226 | */ | |
1da177e4 LT |
227 | int eth_header_cache(struct neighbour *neigh, struct hh_cache *hh) |
228 | { | |
229 | unsigned short type = hh->hh_type; | |
230 | struct ethhdr *eth; | |
231 | struct net_device *dev = neigh->dev; | |
232 | ||
233 | eth = (struct ethhdr*) | |
234 | (((u8*)hh->hh_data) + (HH_DATA_OFF(sizeof(*eth)))); | |
235 | ||
236 | if (type == __constant_htons(ETH_P_802_3)) | |
237 | return -1; | |
238 | ||
239 | eth->h_proto = type; | |
240 | memcpy(eth->h_source, dev->dev_addr, dev->addr_len); | |
241 | memcpy(eth->h_dest, neigh->ha, dev->addr_len); | |
242 | hh->hh_len = ETH_HLEN; | |
243 | return 0; | |
244 | } | |
245 | ||
d3e01f71 SH |
246 | /** |
247 | * eth_header_cache_update - update cache entry | |
248 | * @hh: destination cache entry | |
249 | * @dev: network device | |
250 | * @haddr: new hardware address | |
251 | * | |
1da177e4 LT |
252 | * Called by Address Resolution module to notify changes in address. |
253 | */ | |
1da177e4 LT |
254 | void eth_header_cache_update(struct hh_cache *hh, struct net_device *dev, unsigned char * haddr) |
255 | { | |
256 | memcpy(((u8*)hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)), | |
257 | haddr, dev->addr_len); | |
258 | } | |
259 | ||
260 | EXPORT_SYMBOL(eth_type_trans); | |
261 | ||
d3e01f71 SH |
262 | /** |
263 | * eth_mac_addr - set new Ethernet hardware address | |
264 | * @dev: network device | |
265 | * @p: socket address | |
266 | * Change hardware address of device. | |
267 | * | |
268 | * This doesn't change hardware matching, so needs to be overridden | |
269 | * for most real devices. | |
270 | */ | |
1da177e4 LT |
271 | static int eth_mac_addr(struct net_device *dev, void *p) |
272 | { | |
273 | struct sockaddr *addr=p; | |
274 | if (netif_running(dev)) | |
275 | return -EBUSY; | |
276 | memcpy(dev->dev_addr, addr->sa_data,dev->addr_len); | |
277 | return 0; | |
278 | } | |
279 | ||
d3e01f71 SH |
280 | /** |
281 | * eth_change_mtu - set new MTU size | |
282 | * @dev: network device | |
283 | * @new_mtu: new Maximum Transfer Unit | |
284 | * | |
285 | * Allow changing MTU size. Needs to be overridden for devices | |
286 | * supporting jumbo frames. | |
287 | */ | |
1da177e4 LT |
288 | static int eth_change_mtu(struct net_device *dev, int new_mtu) |
289 | { | |
46f25dff | 290 | if (new_mtu < 68 || new_mtu > ETH_DATA_LEN) |
1da177e4 LT |
291 | return -EINVAL; |
292 | dev->mtu = new_mtu; | |
293 | return 0; | |
294 | } | |
295 | ||
d3e01f71 SH |
296 | /** |
297 | * ether_setup - setup Ethernet network device | |
298 | * @dev: network device | |
299 | * Fill in the fields of the device structure with Ethernet-generic values. | |
1da177e4 LT |
300 | */ |
301 | void ether_setup(struct net_device *dev) | |
302 | { | |
303 | dev->change_mtu = eth_change_mtu; | |
304 | dev->hard_header = eth_header; | |
305 | dev->rebuild_header = eth_rebuild_header; | |
306 | dev->set_mac_address = eth_mac_addr; | |
307 | dev->hard_header_cache = eth_header_cache; | |
308 | dev->header_cache_update= eth_header_cache_update; | |
309 | dev->hard_header_parse = eth_header_parse; | |
310 | ||
311 | dev->type = ARPHRD_ETHER; | |
312 | dev->hard_header_len = ETH_HLEN; | |
46f25dff | 313 | dev->mtu = ETH_DATA_LEN; |
1da177e4 LT |
314 | dev->addr_len = ETH_ALEN; |
315 | dev->tx_queue_len = 1000; /* Ethernet wants good queues */ | |
316 | dev->flags = IFF_BROADCAST|IFF_MULTICAST; | |
317 | ||
318 | memset(dev->broadcast,0xFF, ETH_ALEN); | |
319 | ||
320 | } | |
321 | EXPORT_SYMBOL(ether_setup); | |
322 | ||
323 | /** | |
d3e01f71 | 324 | * alloc_etherdev - Allocates and sets up an Ethernet device |
1da177e4 | 325 | * @sizeof_priv: Size of additional driver-private structure to be allocated |
d3e01f71 | 326 | * for this Ethernet device |
1da177e4 | 327 | * |
d3e01f71 | 328 | * Fill in the fields of the device structure with Ethernet-generic |
1da177e4 LT |
329 | * values. Basically does everything except registering the device. |
330 | * | |
331 | * Constructs a new net device, complete with a private data area of | |
d3e01f71 | 332 | * size (sizeof_priv). A 32-byte (not bit) alignment is enforced for |
1da177e4 LT |
333 | * this private data area. |
334 | */ | |
335 | ||
336 | struct net_device *alloc_etherdev(int sizeof_priv) | |
337 | { | |
338 | return alloc_netdev(sizeof_priv, "eth%d", ether_setup); | |
339 | } | |
340 | EXPORT_SYMBOL(alloc_etherdev); |