diff options
Diffstat (limited to 'net/ethernet/eth.c')
| -rw-r--r-- | net/ethernet/eth.c | 308 |
1 files changed, 308 insertions, 0 deletions
diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c new file mode 100644 index 0000000..16c4234 --- /dev/null +++ b/net/ethernet/eth.c @@ -0,0 +1,308 @@ +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * Ethernet-type device handling. + * + * Version: @(#)eth.c 1.0.7 05/25/93 + * + * Authors: Ross Biro, <bir7@leland.Stanford.Edu> + * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> + * Mark Evans, <evansmp@uhura.aston.ac.uk> + * Florian La Roche, <rzsfl@rz.uni-sb.de> + * Alan Cox, <gw4pts@gw4pts.ampr.org> + * + * Fixes: + * Mr Linux : Arp problems + * Alan Cox : Generic queue tidyup (very tiny here) + * Alan Cox : eth_header ntohs should be htons + * Alan Cox : eth_rebuild_header missing an htons and + * minor other things. + * Tegge : Arp bug fixes. + * Florian : Removed many unnecessary functions, code cleanup + * and changes for new arp and skbuff. + * Alan Cox : Redid header building to reflect new format. + * Alan Cox : ARP only when compiled with CONFIG_INET + * Greg Page : 802.2 and SNAP stuff. + * Alan Cox : MAC layer pointers/new format. + * Paul Gortmaker : eth_copy_and_sum shouldn't csum padding. + * Alan Cox : Protect against forwarding explosions with + * older network drivers and IFF_ALLMULTI. + * Christer Weinigel : Better rebuild header message. + * Andrew Morton : 26Feb01: kill ether_setup() - use netdev_boot_setup(). + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ +#include <linux/module.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/string.h> +#include <linux/mm.h> +#include <linux/socket.h> +#include <linux/in.h> +#include <linux/inet.h> +#include <linux/ip.h> +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include <linux/skbuff.h> +#include <linux/errno.h> +#include <linux/config.h> +#include <linux/init.h> +#include <net/dst.h> +#include <net/arp.h> +#include <net/sock.h> +#include <net/ipv6.h> +#include <net/ip.h> +#include <asm/uaccess.h> +#include <asm/system.h> +#include <asm/checksum.h> + +extern int __init netdev_boot_setup(char *str); + +__setup("ether=", netdev_boot_setup); + +/* + * Create the Ethernet MAC header for an arbitrary protocol layer + * + * saddr=NULL means use device source address + * daddr=NULL means leave destination address (eg unresolved arp) + */ + +int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, + void *daddr, void *saddr, unsigned len) +{ + struct ethhdr *eth = (struct ethhdr *)skb_push(skb,ETH_HLEN); + + /* + * Set the protocol type. For a packet of type ETH_P_802_3 we put the length + * in here instead. It is up to the 802.2 layer to carry protocol information. + */ + + if(type!=ETH_P_802_3) + eth->h_proto = htons(type); + else + eth->h_proto = htons(len); + + /* + * Set the source hardware address. + */ + + if(saddr) + memcpy(eth->h_source,saddr,dev->addr_len); + else + memcpy(eth->h_source,dev->dev_addr,dev->addr_len); + + /* + * Anyway, the loopback-device should never use this function... + */ + + if (dev->flags & (IFF_LOOPBACK|IFF_NOARP)) + { + memset(eth->h_dest, 0, dev->addr_len); + return ETH_HLEN; + } + + if(daddr) + { + memcpy(eth->h_dest,daddr,dev->addr_len); + return ETH_HLEN; + } + + return -ETH_HLEN; +} + + +/* + * Rebuild the Ethernet MAC header. This is called after an ARP + * (or in future other address resolution) has completed on this + * sk_buff. We now let ARP fill in the other fields. + * + * This routine CANNOT use cached dst->neigh! + * Really, it is used only when dst->neigh is wrong. + */ + +int eth_rebuild_header(struct sk_buff *skb) +{ + struct ethhdr *eth = (struct ethhdr *)skb->data; + struct net_device *dev = skb->dev; + + switch (eth->h_proto) + { +#ifdef CONFIG_INET + case __constant_htons(ETH_P_IP): + return arp_find(eth->h_dest, skb); +#endif + default: + printk(KERN_DEBUG + "%s: unable to resolve type %X addresses.\n", + dev->name, (int)eth->h_proto); + + memcpy(eth->h_source, dev->dev_addr, dev->addr_len); + break; + } + + return 0; +} + + +/* + * Determine the packet's protocol ID. The rule here is that we + * assume 802.3 if the type field is short enough to be a length. + * This is normal practice and works for any 'now in use' protocol. + */ + +unsigned short eth_type_trans(struct sk_buff *skb, struct net_device *dev) +{ + struct ethhdr *eth; + unsigned char *rawp; + + skb->mac.raw=skb->data; + skb_pull(skb,ETH_HLEN); + eth = eth_hdr(skb); + skb->input_dev = dev; + + if(*eth->h_dest&1) + { + if(memcmp(eth->h_dest,dev->broadcast, ETH_ALEN)==0) + skb->pkt_type=PACKET_BROADCAST; + else + skb->pkt_type=PACKET_MULTICAST; + } + + /* + * This ALLMULTI check should be redundant by 1.4 + * so don't forget to remove it. + * + * Seems, you forgot to remove it. All silly devices + * seems to set IFF_PROMISC. + */ + + else if(1 /*dev->flags&IFF_PROMISC*/) + { + if(memcmp(eth->h_dest,dev->dev_addr, ETH_ALEN)) + skb->pkt_type=PACKET_OTHERHOST; + } + + if (ntohs(eth->h_proto) >= 1536) + return eth->h_proto; + + rawp = skb->data; + + /* + * This is a magic hack to spot IPX packets. Older Novell breaks + * the protocol design and runs IPX over 802.3 without an 802.2 LLC + * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This + * won't work for fault tolerant netware but does for the rest. + */ + if (*(unsigned short *)rawp == 0xFFFF) + return htons(ETH_P_802_3); + + /* + * Real 802.2 LLC + */ + return htons(ETH_P_802_2); +} + +static int eth_header_parse(struct sk_buff *skb, unsigned char *haddr) +{ + struct ethhdr *eth = eth_hdr(skb); + memcpy(haddr, eth->h_source, ETH_ALEN); + return ETH_ALEN; +} + +int eth_header_cache(struct neighbour *neigh, struct hh_cache *hh) +{ + unsigned short type = hh->hh_type; + struct ethhdr *eth; + struct net_device *dev = neigh->dev; + + eth = (struct ethhdr*) + (((u8*)hh->hh_data) + (HH_DATA_OFF(sizeof(*eth)))); + + if (type == __constant_htons(ETH_P_802_3)) + return -1; + + eth->h_proto = type; + memcpy(eth->h_source, dev->dev_addr, dev->addr_len); + memcpy(eth->h_dest, neigh->ha, dev->addr_len); + hh->hh_len = ETH_HLEN; + return 0; +} + +/* + * Called by Address Resolution module to notify changes in address. + */ + +void eth_header_cache_update(struct hh_cache *hh, struct net_device *dev, unsigned char * haddr) +{ + memcpy(((u8*)hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)), + haddr, dev->addr_len); +} + +EXPORT_SYMBOL(eth_type_trans); + +static int eth_mac_addr(struct net_device *dev, void *p) +{ + struct sockaddr *addr=p; + if (netif_running(dev)) + return -EBUSY; + memcpy(dev->dev_addr, addr->sa_data,dev->addr_len); + return 0; +} + +static int eth_change_mtu(struct net_device *dev, int new_mtu) +{ + if ((new_mtu < 68) || (new_mtu > 1500)) + return -EINVAL; + dev->mtu = new_mtu; + return 0; +} + +/* + * Fill in the fields of the device structure with ethernet-generic values. + */ +void ether_setup(struct net_device *dev) +{ + dev->change_mtu = eth_change_mtu; + dev->hard_header = eth_header; + dev->rebuild_header = eth_rebuild_header; + dev->set_mac_address = eth_mac_addr; + dev->hard_header_cache = eth_header_cache; + dev->header_cache_update= eth_header_cache_update; + dev->hard_header_parse = eth_header_parse; + + dev->type = ARPHRD_ETHER; + dev->hard_header_len = ETH_HLEN; + dev->mtu = 1500; /* eth_mtu */ + dev->addr_len = ETH_ALEN; + dev->tx_queue_len = 1000; /* Ethernet wants good queues */ + dev->flags = IFF_BROADCAST|IFF_MULTICAST; + + memset(dev->broadcast,0xFF, ETH_ALEN); + +} +EXPORT_SYMBOL(ether_setup); + +/** + * alloc_etherdev - Allocates and sets up an ethernet device + * @sizeof_priv: Size of additional driver-private structure to be allocated + * for this ethernet device + * + * Fill in the fields of the device structure with ethernet-generic + * values. Basically does everything except registering the device. + * + * Constructs a new net device, complete with a private data area of + * size @sizeof_priv. A 32-byte (not bit) alignment is enforced for + * this private data area. + */ + +struct net_device *alloc_etherdev(int sizeof_priv) +{ + return alloc_netdev(sizeof_priv, "eth%d", ether_setup); +} +EXPORT_SYMBOL(alloc_etherdev); |