Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | * |
Jesper Juhl | 02c30a8 | 2005-05-05 16:16:16 -0700 | [diff] [blame] | 10 | * Authors: Ross Biro |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Denis Vlasenko | ff593c5 | 2005-06-28 15:49:06 -0700 | [diff] [blame] | 95 | if(!saddr) |
| 96 | saddr = dev->dev_addr; |
| 97 | memcpy(eth->h_source,saddr,dev->addr_len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Alexey Dobriyan | ab61148 | 2005-07-12 12:08:43 -0700 | [diff] [blame^] | 158 | __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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); |