/*
* Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
*
* 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 any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <byteswap.h>
#include <errno.h>
#include <assert.h>
#include <ipxe/if_arp.h>
#include <ipxe/if_ether.h>
#include <ipxe/in.h>
#include <ipxe/netdevice.h>
#include <ipxe/iobuf.h>
#include <ipxe/ethernet.h>
/** @file
*
* Ethernet protocol
*
*/
/** Ethernet broadcast MAC address */
uint8_t eth_broadcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
/**
* Check if Ethernet packet has an 802.3 LLC header
*
* @v ethhdr Ethernet header
* @ret is_llc Packet has 802.3 LLC header
*/
static inline int eth_is_llc_packet ( struct ethhdr *ethhdr ) {
uint8_t len_msb;
/* Check if the protocol field contains a value short enough
* to be a frame length. The slightly convoluted form of the
* comparison is designed to reduce to a single x86
* instruction.
*/
len_msb = *( ( uint8_t * ) ðhdr->h_protocol );
return ( len_msb < 0x06 );
}
/**
* Add Ethernet link-layer header
*
* @v netdev Network device
* @v iobuf I/O buffer
* @v ll_dest Link-layer destination address
* @v ll_source Source link-layer address
* @v net_proto Network-layer protocol, in network-byte order
* @ret rc Return status code
*/
int eth_push ( struct net_device *netdev __unused, struct io_buffer *iobuf,
const void *ll_dest, const void *ll_source,
uint16_t net_proto ) {
struct ethhdr *ethhdr = iob_push ( iobuf, sizeof ( *ethhdr ) );
/* Build Ethernet header */
memcpy ( ethhdr->h_dest, ll_dest, ETH_ALEN );
memcpy ( ethhdr->h_source, ll_source, ETH_ALEN );
ethhdr->h_protocol = net_proto;
return 0;
}
/**
* Remove Ethernet link-layer header
*
* @v netdev Network device
* @v iobuf I/O buffer
* @ret ll_dest Link-layer destination address
* @ret ll_source Source link-layer address
* @ret net_proto Network-layer protocol, in network-byte order
* @ret flags Packet flags
* @ret rc Return status code
*/
int eth_pull ( struct net_device *netdev __unused, struct io_buffer *iobuf,
const void **ll_dest, const void **ll_source,
uint16_t *net_proto, unsigned int *flags ) {
struct ethhdr *ethhdr = iobuf->data;
uint16_t *llc_proto;
/* Sanity check. While in theory we could receive a one-byte
* packet, this will never happen in practice and performing
* the combined length check here avoids the need for an
* additional comparison if we detect an LLC frame.
*/
if ( iob_len ( iobuf ) < ( sizeof ( *ethhdr ) + sizeof ( *llc_proto ))){
DBG ( "Ethernet packet too short (%zd bytes)\n",
iob_len ( iobuf ) );
return -EINVAL;
}
/* Strip off Ethernet header */
iob_pull ( iobuf, sizeof ( *ethhdr ) );
/* Fill in required fields */
*ll_dest = ethhdr->h_dest;
*ll_source = ethhdr->h_source;
*net_proto = ethhdr->h_protocol;
*flags = ( ( is_multicast_ether_addr ( ethhdr->h_dest ) ?
LL_MULTICAST : 0 ) |
( is_broadcast_ether_addr ( ethhdr->h_dest ) ?
LL_BROADCAST : 0 ) );
/* If this is an LLC frame (with a length in place of the
* protocol field), then use the next two bytes (which happen
* to be the LLC DSAP and SSAP) as the protocol. This allows
* for minimal-overhead support for receiving (rare) LLC
* frames, without requiring a full LLC protocol layer.
*/
if ( eth_is_llc_packet ( ethhdr ) ) {
llc_proto = ( ðhdr->h_protocol + 1 );
*net_proto = *llc_proto;
}
return 0;
}
/**
* Initialise Ethernet address
*
* @v hw_addr Hardware address
* @v ll_addr Link-layer address
*/
void eth_init_addr ( const void *hw_addr, void *ll_addr ) {
memcpy ( ll_addr, hw_addr, ETH_ALEN );
}
/**
* Generate random Ethernet address
*
* @v hw_addr Generated hardware address
*/
void eth_random_addr ( void *hw_addr ) {
uint8_t *addr = hw_addr;
unsigned int i;
for ( i = 0 ; i < ETH_ALEN ; i++ )
addr[i] = random();
addr[0] &= ~0x01; /* Clear multicast bit */
addr[0] |= 0x02; /* Set locally-assigned bit */
}
/**
* Transcribe Ethernet address
*
* @v ll_addr Link-layer address
* @ret string Link-layer address in human-readable format
*/
const char * eth_ntoa ( const void *ll_addr ) {
static char buf[18]; /* "00:00:00:00:00:00" */
const uint8_t *eth_addr = ll_addr;
sprintf ( buf, "%02x:%02x:%02x:%02x:%02x:%02x",
eth_addr[0], eth_addr[1], eth_addr[2],
eth_addr[3], eth_addr[4], eth_addr[5] );
return buf;
}
/**
* Hash multicast address
*
* @v af Address family
* @v net_addr Network-layer address
* @v ll_addr Link-layer address to fill in
* @ret rc Return status code
*/
int eth_mc_hash ( unsigned int af, const void *net_addr, void *ll_addr ) {
const uint8_t *net_addr_bytes = net_addr;
uint8_t *ll_addr_bytes = ll_addr;
switch ( af ) {
case AF_INET:
ll_addr_bytes[0] = 0x01;
ll_addr_bytes[1] = 0x00;
ll_addr_bytes[2] = 0x5e;
ll_addr_bytes[3] = net_addr_bytes[1] & 0x7f;
ll_addr_bytes[4] = net_addr_bytes[2];
ll_addr_bytes[5] = net_addr_bytes[3];
return 0;
case AF_INET6:
ll_addr_bytes[0] = 0x33;
ll_addr_bytes[1] = 0x33;
memcpy ( &ll_addr_bytes[2], &net_addr_bytes[12], 4 );
return 0;
default:
return -ENOTSUP;
}
}
/**
* Generate Ethernet-compatible compressed link-layer address
*
* @v ll_addr Link-layer address
* @v eth_addr Ethernet-compatible address to fill in
*/
int eth_eth_addr ( const void *ll_addr, void *eth_addr ) {
memcpy ( eth_addr, ll_addr, ETH_ALEN );
return 0;
}
/**
* Generate EUI-64 address
*
* @v ll_addr Link-layer address
* @v eui64 EUI-64 address to fill in
* @ret rc Return status code
*/
int eth_eui64 ( const void *ll_addr, void *eui64 ) {
memcpy ( ( eui64 + 0 ), ( ll_addr + 0 ), 3 );
memcpy ( ( eui64 + 5 ), ( ll_addr + 3 ), 3 );
*( ( uint16_t * ) ( eui64 + 3 ) ) = htons ( 0xfffe );
return 0;
}
/** Ethernet protocol */
struct ll_protocol ethernet_protocol __ll_protocol = {
.name = "Ethernet",
.ll_proto = htons ( ARPHRD_ETHER ),
.hw_addr_len = ETH_ALEN,
.ll_addr_len = ETH_ALEN,
.ll_header_len = ETH_HLEN,
.push = eth_push,
.pull = eth_pull,
.init_addr = eth_init_addr,
.ntoa = eth_ntoa,
.mc_hash = eth_mc_hash,
.eth_addr = eth_eth_addr,
.eui64 = eth_eui64,
};
/**
* Allocate Ethernet device
*
* @v priv_size Size of driver private data
* @ret netdev Network device, or NULL
*/
struct net_device * alloc_etherdev ( size_t priv_size ) {
struct net_device *netdev;
netdev = alloc_netdev ( priv_size );
if ( netdev ) {
netdev->ll_protocol = ðernet_protocol;
netdev->ll_broadcast = eth_broadcast;
netdev->max_pkt_len = ETH_FRAME_LEN;
netdev->mtu = ETH_MAX_MTU;
}
return netdev;
}
/* Drag in objects via ethernet_protocol */
REQUIRING_SYMBOL ( ethernet_protocol );
/* Drag in Ethernet configuration */
REQUIRE_OBJECT ( config_ethernet );
