Commit | Line | Data |
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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> | |
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 | ||
65 | extern 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 | ||
76 | int 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 | ||
ff593c59 DV |
95 | if(!saddr) |
96 | saddr = dev->dev_addr; | |
97 | memcpy(eth->h_source,saddr,dev->addr_len); | |
1da177e4 LT |
98 | |
99 | /* | |
100 | * Anyway, the loopback-device should never use this function... | |
101 | */ | |
102 | ||
103 | if (dev->flags & (IFF_LOOPBACK|IFF_NOARP)) | |
104 | { | |
105 | memset(eth->h_dest, 0, dev->addr_len); | |
106 | return ETH_HLEN; | |
107 | } | |
108 | ||
109 | if(daddr) | |
110 | { | |
111 | memcpy(eth->h_dest,daddr,dev->addr_len); | |
112 | return ETH_HLEN; | |
113 | } | |
114 | ||
115 | return -ETH_HLEN; | |
116 | } | |
117 | ||
118 | ||
119 | /* | |
120 | * Rebuild the Ethernet MAC header. This is called after an ARP | |
121 | * (or in future other address resolution) has completed on this | |
122 | * sk_buff. We now let ARP fill in the other fields. | |
123 | * | |
124 | * This routine CANNOT use cached dst->neigh! | |
125 | * Really, it is used only when dst->neigh is wrong. | |
126 | */ | |
127 | ||
128 | int eth_rebuild_header(struct sk_buff *skb) | |
129 | { | |
130 | struct ethhdr *eth = (struct ethhdr *)skb->data; | |
131 | struct net_device *dev = skb->dev; | |
132 | ||
133 | switch (eth->h_proto) | |
134 | { | |
135 | #ifdef CONFIG_INET | |
136 | case __constant_htons(ETH_P_IP): | |
137 | return arp_find(eth->h_dest, skb); | |
138 | #endif | |
139 | default: | |
140 | printk(KERN_DEBUG | |
141 | "%s: unable to resolve type %X addresses.\n", | |
142 | dev->name, (int)eth->h_proto); | |
143 | ||
144 | memcpy(eth->h_source, dev->dev_addr, dev->addr_len); | |
145 | break; | |
146 | } | |
147 | ||
148 | return 0; | |
149 | } | |
150 | ||
151 | ||
152 | /* | |
153 | * Determine the packet's protocol ID. 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. | |
156 | */ | |
157 | ||
ab611487 | 158 | __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev) |
1da177e4 LT |
159 | { |
160 | struct ethhdr *eth; | |
161 | unsigned char *rawp; | |
162 | ||
163 | skb->mac.raw=skb->data; | |
164 | skb_pull(skb,ETH_HLEN); | |
165 | eth = eth_hdr(skb); | |
166 | skb->input_dev = dev; | |
167 | ||
168 | if(*eth->h_dest&1) | |
169 | { | |
170 | if(memcmp(eth->h_dest,dev->broadcast, ETH_ALEN)==0) | |
171 | skb->pkt_type=PACKET_BROADCAST; | |
172 | else | |
173 | skb->pkt_type=PACKET_MULTICAST; | |
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 | ||
184 | else if(1 /*dev->flags&IFF_PROMISC*/) | |
185 | { | |
186 | if(memcmp(eth->h_dest,dev->dev_addr, ETH_ALEN)) | |
187 | skb->pkt_type=PACKET_OTHERHOST; | |
188 | } | |
189 | ||
190 | if (ntohs(eth->h_proto) >= 1536) | |
191 | return eth->h_proto; | |
192 | ||
193 | rawp = skb->data; | |
194 | ||
195 | /* | |
196 | * This is a magic hack to spot IPX packets. Older Novell breaks | |
197 | * the protocol design and runs IPX over 802.3 without an 802.2 LLC | |
198 | * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This | |
199 | * won't work for fault tolerant netware but does for the rest. | |
200 | */ | |
201 | if (*(unsigned short *)rawp == 0xFFFF) | |
202 | return htons(ETH_P_802_3); | |
203 | ||
204 | /* | |
205 | * Real 802.2 LLC | |
206 | */ | |
207 | return htons(ETH_P_802_2); | |
208 | } | |
209 | ||
210 | static int eth_header_parse(struct sk_buff *skb, unsigned char *haddr) | |
211 | { | |
212 | struct ethhdr *eth = eth_hdr(skb); | |
213 | memcpy(haddr, eth->h_source, ETH_ALEN); | |
214 | return ETH_ALEN; | |
215 | } | |
216 | ||
217 | int eth_header_cache(struct neighbour *neigh, struct hh_cache *hh) | |
218 | { | |
219 | unsigned short type = hh->hh_type; | |
220 | struct ethhdr *eth; | |
221 | struct net_device *dev = neigh->dev; | |
222 | ||
223 | eth = (struct ethhdr*) | |
224 | (((u8*)hh->hh_data) + (HH_DATA_OFF(sizeof(*eth)))); | |
225 | ||
226 | if (type == __constant_htons(ETH_P_802_3)) | |
227 | return -1; | |
228 | ||
229 | eth->h_proto = type; | |
230 | memcpy(eth->h_source, dev->dev_addr, dev->addr_len); | |
231 | memcpy(eth->h_dest, neigh->ha, dev->addr_len); | |
232 | hh->hh_len = ETH_HLEN; | |
233 | return 0; | |
234 | } | |
235 | ||
236 | /* | |
237 | * Called by Address Resolution module to notify changes in address. | |
238 | */ | |
239 | ||
240 | void eth_header_cache_update(struct hh_cache *hh, struct net_device *dev, unsigned char * haddr) | |
241 | { | |
242 | memcpy(((u8*)hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)), | |
243 | haddr, dev->addr_len); | |
244 | } | |
245 | ||
246 | EXPORT_SYMBOL(eth_type_trans); | |
247 | ||
248 | static int eth_mac_addr(struct net_device *dev, void *p) | |
249 | { | |
250 | struct sockaddr *addr=p; | |
251 | if (netif_running(dev)) | |
252 | return -EBUSY; | |
253 | memcpy(dev->dev_addr, addr->sa_data,dev->addr_len); | |
254 | return 0; | |
255 | } | |
256 | ||
257 | static int eth_change_mtu(struct net_device *dev, int new_mtu) | |
258 | { | |
259 | if ((new_mtu < 68) || (new_mtu > 1500)) | |
260 | return -EINVAL; | |
261 | dev->mtu = new_mtu; | |
262 | return 0; | |
263 | } | |
264 | ||
265 | /* | |
266 | * Fill in the fields of the device structure with ethernet-generic values. | |
267 | */ | |
268 | void ether_setup(struct net_device *dev) | |
269 | { | |
270 | dev->change_mtu = eth_change_mtu; | |
271 | dev->hard_header = eth_header; | |
272 | dev->rebuild_header = eth_rebuild_header; | |
273 | dev->set_mac_address = eth_mac_addr; | |
274 | dev->hard_header_cache = eth_header_cache; | |
275 | dev->header_cache_update= eth_header_cache_update; | |
276 | dev->hard_header_parse = eth_header_parse; | |
277 | ||
278 | dev->type = ARPHRD_ETHER; | |
279 | dev->hard_header_len = ETH_HLEN; | |
280 | dev->mtu = 1500; /* eth_mtu */ | |
281 | dev->addr_len = ETH_ALEN; | |
282 | dev->tx_queue_len = 1000; /* Ethernet wants good queues */ | |
283 | dev->flags = IFF_BROADCAST|IFF_MULTICAST; | |
284 | ||
285 | memset(dev->broadcast,0xFF, ETH_ALEN); | |
286 | ||
287 | } | |
288 | EXPORT_SYMBOL(ether_setup); | |
289 | ||
290 | /** | |
291 | * alloc_etherdev - Allocates and sets up an ethernet device | |
292 | * @sizeof_priv: Size of additional driver-private structure to be allocated | |
293 | * for this ethernet device | |
294 | * | |
295 | * Fill in the fields of the device structure with ethernet-generic | |
296 | * values. Basically does everything except registering the device. | |
297 | * | |
298 | * Constructs a new net device, complete with a private data area of | |
299 | * size @sizeof_priv. A 32-byte (not bit) alignment is enforced for | |
300 | * this private data area. | |
301 | */ | |
302 | ||
303 | struct net_device *alloc_etherdev(int sizeof_priv) | |
304 | { | |
305 | return alloc_netdev(sizeof_priv, "eth%d", ether_setup); | |
306 | } | |
307 | EXPORT_SYMBOL(alloc_etherdev); |