- 根目录:
- net
- ethernet
- eth.c
/*
* 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
* 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/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/init.h>
#include <linux/if_ether.h>
#include <net/dst.h>
#include <net/arp.h>
#include <net/sock.h>
#include <net/ipv6.h>
#include <net/ip.h>
#include <net/dsa.h>
#include <linux/uaccess.h>
__setup("ether=", netdev_boot_setup);
/**
* eth_header - create the Ethernet header
* @skb: buffer to alter
* @dev: source device
* @type: Ethernet type field
* @daddr: destination address (NULL leave destination address)
* @saddr: source address (NULL use device source address)
* @len: packet length (<= skb->len)
*
*
* Set the protocol type. For a packet of type ETH_P_802_3/2 we put the length
* in here instead.
*/
int eth_header(struct sk_buff *skb, struct net_device *dev,
unsigned short type,
const void *daddr, const void *saddr, unsigned int len)
{
struct ethhdr *eth = (struct ethhdr *)skb_push(skb, ETH_HLEN);
if (type != ETH_P_802_3 && type != ETH_P_802_2)
eth->h_proto = htons(type);
else
eth->h_proto = htons(len);
/*
* Set the source hardware address.
*/
if (!saddr)
saddr = dev->dev_addr;
memcpy(eth->h_source, saddr, ETH_ALEN);
if (daddr) {
memcpy(eth->h_dest, daddr, ETH_ALEN);
return ETH_HLEN;
}
/*
* Anyway, the loopback-device should never use this function...
*/
if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
memset(eth->h_dest, 0, ETH_ALEN);
return ETH_HLEN;
}
return -ETH_HLEN;
}
EXPORT_SYMBOL(eth_header);
/**
* eth_rebuild_header- rebuild the Ethernet MAC header.
* @skb: socket buffer to update
*
* This is called after an ARP or IPV6 ndisc it's resolution on this
* sk_buff. We now let protocol (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 htons(ETH_P_IP):
return arp_find(eth->h_dest, skb);
#endif
default:
netdev_dbg(dev,
"%s: unable to resolve type %X addresses.\n",
dev->name, ntohs(eth->h_proto));
memcpy(eth->h_source, dev->dev_addr, ETH_ALEN);
break;
}
return 0;
}
EXPORT_SYMBOL(eth_rebuild_header);
/**
* eth_type_trans - determine the packet's protocol ID.
* @skb: received socket data
* @dev: receiving network device
*
* 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.
*/
__be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev)
{
unsigned short _service_access_point;
const unsigned short *sap;
const struct ethhdr *eth;
skb->dev = dev;
skb_reset_mac_header(skb);
skb_pull_inline(skb, ETH_HLEN);
eth = eth_hdr(skb);
if (unlikely(is_multicast_ether_addr(eth->h_dest))) {
if (ether_addr_equal_64bits(eth->h_dest, dev->broadcast))
skb->pkt_type = PACKET_BROADCAST;
else
skb->pkt_type = PACKET_MULTICAST;
}
else if (unlikely(!ether_addr_equal_64bits(eth->h_dest,
dev->dev_addr)))
skb->pkt_type = PACKET_OTHERHOST;
/*
* Some variants of DSA tagging don't have an ethertype field
* at all, so we check here whether one of those tagging
* variants has been configured on the receiving interface,
* and if so, set skb->protocol without looking at the packet.
*/
if (unlikely(netdev_uses_dsa_tags(dev)))
return htons(ETH_P_DSA);
if (unlikely(netdev_uses_trailer_tags(dev)))
return htons(ETH_P_TRAILER);
if (likely(ntohs(eth->h_proto) >= ETH_P_802_3_MIN))
return eth->h_proto;
/*
* 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.
*/
sap = skb_header_pointer(skb, 0, sizeof(*sap), &_service_access_point);
if (sap && *sap == 0xFFFF)
return htons(ETH_P_802_3);
/*
* Real 802.2 LLC
*/
return htons(ETH_P_802_2);
}
EXPORT_SYMBOL(eth_type_trans);
/**
* eth_header_parse - extract hardware address from packet
* @skb: packet to extract header from
* @haddr: destination buffer
*/
int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr)
{
const struct ethhdr *eth = eth_hdr(skb);
memcpy(haddr, eth->h_source, ETH_ALEN);
return ETH_ALEN;
}
EXPORT_SYMBOL(eth_header_parse);
/**
* eth_header_cache - fill cache entry from neighbour
* @neigh: source neighbour
* @hh: destination cache entry
* @type: Ethernet type field
*
* Create an Ethernet header template from the neighbour.
*/
int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, __be16 type)
{
struct ethhdr *eth;
const struct net_device *dev = neigh->dev;
eth = (struct ethhdr *)
(((u8 *) hh->hh_data) + (HH_DATA_OFF(sizeof(*eth))));
if (type == htons(ETH_P_802_3))
return -1;
eth->h_proto = type;
memcpy(eth->h_source, dev->dev_addr, ETH_ALEN);
memcpy(eth->h_dest, neigh->ha, ETH_ALEN);
hh->hh_len = ETH_HLEN;
return 0;
}
EXPORT_SYMBOL(eth_header_cache);
/**
* eth_header_cache_update - update cache entry
* @hh: destination cache entry
* @dev: network device
* @haddr: new hardware address
*
* Called by Address Resolution module to notify changes in address.
*/
void eth_header_cache_update(struct hh_cache *hh,
const struct net_device *dev,
const unsigned char *haddr)
{
memcpy(((u8 *) hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)),
haddr, ETH_ALEN);
}
EXPORT_SYMBOL(eth_header_cache_update);
/**
* eth_prepare_mac_addr_change - prepare for mac change
* @dev: network device
* @p: socket address
*/
int eth_prepare_mac_addr_change(struct net_device *dev, void *p)
{
struct sockaddr *addr = p;
if (!(dev->priv_flags & IFF_LIVE_ADDR_CHANGE) && netif_running(dev))
return -EBUSY;
if (!is_valid_ether_addr(addr->sa_data))
return -EADDRNOTAVAIL;
return 0;
}
EXPORT_SYMBOL(eth_prepare_mac_addr_change);
/**
* eth_commit_mac_addr_change - commit mac change
* @dev: network device
* @p: socket address
*/
void eth_commit_mac_addr_change(struct net_device *dev, void *p)
{
struct sockaddr *addr = p;
memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
}
EXPORT_SYMBOL(eth_commit_mac_addr_change);
/**
* eth_mac_addr - set new Ethernet hardware address
* @dev: network device
* @p: socket address
*
* Change hardware address of device.
*
* This doesn't change hardware matching, so needs to be overridden
* for most real devices.
*/
int eth_mac_addr(struct net_device *dev, void *p)
{
int ret;
ret = eth_prepare_mac_addr_change(dev, p);
if (ret < 0)
return ret;
eth_commit_mac_addr_change(dev, p);
return 0;
}
EXPORT_SYMBOL(eth_mac_addr);
/**
* eth_change_mtu - set new MTU size
* @dev: network device
* @new_mtu: new Maximum Transfer Unit
*
* Allow changing MTU size. Needs to be overridden for devices
* supporting jumbo frames.
*/
int eth_change_mtu(struct net_device *dev, int new_mtu)
{
if (new_mtu < 68 || new_mtu > ETH_DATA_LEN)
return -EINVAL;
dev->mtu = new_mtu;
return 0;
}
EXPORT_SYMBOL(eth_change_mtu);
int eth_validate_addr(struct net_device *dev)
{
if (!is_valid_ether_addr(dev->dev_addr))
return -EADDRNOTAVAIL;
return 0;
}
EXPORT_SYMBOL(eth_validate_addr);
const struct header_ops eth_header_ops ____cacheline_aligned = {
.create = eth_header,
.parse = eth_header_parse,
.rebuild = eth_rebuild_header,
.cache = eth_header_cache,
.cache_update = eth_header_cache_update,
};
/**
* ether_setup - setup Ethernet network device
* @dev: network device
*
* Fill in the fields of the device structure with Ethernet-generic values.
*/
void ether_setup(struct net_device *dev)
{
dev->header_ops = ð_header_ops;
dev->type = ARPHRD_ETHER;
dev->hard_header_len = ETH_HLEN;
dev->mtu = ETH_DATA_LEN;
dev->addr_len = ETH_ALEN;
dev->tx_queue_len = 1000; /* Ethernet wants good queues */
dev->flags = IFF_BROADCAST|IFF_MULTICAST;
dev->priv_flags |= IFF_TX_SKB_SHARING;
memset(dev->broadcast, 0xFF, ETH_ALEN);
}
EXPORT_SYMBOL(ether_setup);
/**
* alloc_etherdev_mqs - Allocates and sets up an Ethernet device
* @sizeof_priv: Size of additional driver-private structure to be allocated
* for this Ethernet device
* @txqs: The number of TX queues this device has.
* @rxqs: The number of RX queues this device has.
*
* 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_mqs(int sizeof_priv, unsigned int txqs,
unsigned int rxqs)
{
return alloc_netdev_mqs(sizeof_priv, "eth%d", ether_setup, txqs, rxqs);
}
EXPORT_SYMBOL(alloc_etherdev_mqs);
ssize_t sysfs_format_mac(char *buf, const unsigned char *addr, int len)
{
return scnprintf(buf, PAGE_SIZE, "%*phC\n", len, addr);
}
EXPORT_SYMBOL(sysfs_format_mac);