ethernet.c File Reference

Ethernet protocol. More...

#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>

Go to the source code of this file.

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
	FILE_SECBOOT (PERMITTED)
static int	eth_is_llc_packet (struct ethhdr *ethhdr)
	Check if Ethernet packet has an 802.3 LLC header.
int	eth_push (struct net_device *netdev __unused, struct io_buffer *iobuf, const void *ll_dest, const void *ll_source, uint16_t net_proto)
	Add Ethernet link-layer header.
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)
	Remove Ethernet link-layer header.
void	eth_init_addr (const void *hw_addr, void *ll_addr)
	Initialise Ethernet address.
void	eth_random_addr (void *hw_addr)
	Generate random Ethernet address.
const char *	eth_ntoa (const void *ll_addr)
	Transcribe Ethernet address.
int	eth_mc_hash (unsigned int af, const void *net_addr, void *ll_addr)
	Hash multicast address.
int	eth_eth_addr (const void *ll_addr, void *eth_addr)
	Generate Ethernet-compatible compressed link-layer address.
int	eth_eui64 (const void *ll_addr, void *eui64)
	Generate EUI-64 address.
struct net_device *	alloc_etherdev (size_t priv_size)
	Allocate Ethernet device.
	REQUIRING_SYMBOL (ethernet_protocol)
	REQUIRE_OBJECT (config_ethernet)

Variables
uint8_t	eth_broadcast [ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }
	Ethernet broadcast MAC address.
struct ll_protocol ethernet_protocol	__ll_protocol
	Ethernet protocol.

Detailed Description

Ethernet protocol.

Definition in file ethernet.c.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

FILE_SECBOOT()

FILE_SECBOOT

(

PERMITTED

)

eth_is_llc_packet()

int eth_is_llc_packet ( struct ethhdr * ethhdr )

inlinestatic

Check if Ethernet packet has an 802.3 LLC header.

Parameters

ethhdr

Ethernet header

Return values

is_llc

Packet has 802.3 LLC header

Definition at line 56 of file ethernet.c.

                                                              {
        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 * ) &ethhdr->h_protocol );
        return ( len_msb < 0x06 );
}

References ethhdr::h_protocol.

Referenced by eth_pull().

eth_push()

int eth_push	(	struct net_device *netdev	__unused,
		struct io_buffer *	iobuf,
		const void *	ll_dest,
		const void *	ll_source,
		uint16_t	net_proto )

Add Ethernet link-layer header.

Parameters

netdev	Network device
iobuf	I/O buffer
ll_dest	Link-layer destination address
ll_source	Source link-layer address
net_proto	Network-layer protocol, in network-byte order

Return values

rc	Return status code

Definition at line 78 of file ethernet.c.

                                    {
        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;
}

References __unused, ETH_ALEN, ethhdr::h_dest, ethhdr::h_protocol, ethhdr::h_source, iob_push, memcpy(), and netdev.

eth_pull()

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 )

Remove Ethernet link-layer header.

Parameters

netdev	Network device
iobuf	I/O buffer

Return values

ll_dest	Link-layer destination address
ll_source	Source link-layer address
net_proto	Network-layer protocol, in network-byte order
flags	Packet flags
rc	Return status code

Definition at line 102 of file ethernet.c.

                                                          {
        struct ethhdr *ethhdr;
        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;
        }
        ethhdr = iobuf->data;
 
        /* 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 = iobuf->data;
                *net_proto = *llc_proto;
        }
 
        return 0;
}

References __unused, io_buffer::data, DBG, EINVAL, eth_is_llc_packet(), flags, ethhdr::h_dest, ethhdr::h_protocol, ethhdr::h_source, iob_len(), iob_pull, is_broadcast_ether_addr(), is_multicast_ether_addr(), LL_BROADCAST, LL_MULTICAST, and netdev.

Referenced by undinet_transmit().

eth_init_addr()

void eth_init_addr	(	const void *	hw_addr,
		void *	ll_addr )

Initialise Ethernet address.

Parameters

hw_addr	Hardware address
ll_addr	Link-layer address

Definition at line 152 of file ethernet.c.

                                                          {
        memcpy ( ll_addr, hw_addr, ETH_ALEN );
}

References ETH_ALEN, and memcpy().

eth_random_addr()

void eth_random_addr

(

void *

hw_addr

)

Generate random Ethernet address.

Parameters

hw_addr

Generated hardware address

Definition at line 161 of file ethernet.c.

                                       {
        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 */
}

References addr, ETH_ALEN, and random().

Referenced by igbvf_probe(), intelvf_mbox_reset(), lan78xx_fetch_mac(), smsc95xx_fetch_mac(), txnic_bgx_mac(), and virtio_net_mac().

eth_ntoa()

const char * eth_ntoa

(

const void *

ll_addr

)

Transcribe Ethernet address.

Parameters

ll_addr

Link-layer address

Return values

string

Link-layer address in human-readable format

Definition at line 177 of file ethernet.c.

                                              {
        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;
}

References sprintf.

Referenced by acpimac_extract(), amd8111e_get_mac_address(), b44_probe(), bnx2_probe(), bofm_dummy_harvest(), bofm_dummy_update(), bofm_en(), bofm_test(), corkscrew_probe1(), cs89x0_probe(), davicom_probe(), dmfe_probe(), ecm_fetch_mac(), eepro_probe(), ena_get_device_attributes(), eoib_create(), eoib_rx_av(), eoib_tx_av(), epic100_probe(), eth_probe(), eth_slow_lacp_dump(), eth_slow_marker_dump(), exanic_probe(), fcoe_expired(), fcoe_fip_rx(), fcoe_fip_rx_advertisement(), fcoe_fip_rx_els_response(), fcoe_fip_rx_vlan(), fcoe_rx(), gve_describe(), hermon_bofm_harvest(), hermon_bofm_update(), ibft_fill_nic(), ice_admin_mac_read(), intel_fetch_mac(), intel_fetch_mac_eeprom(), intelvf_mbox_reset(), intelx_try_fetch_mac(), intelxl_admin_mac_read(), ipoib_find_remac(), ipoib_translate_tx_arp(), ipoib_transmit(), iwlist(), lan78xx_fetch_mac(), ne_probe(), net80211_probe_step(), net80211_step_associate(), nv_setup_mac_addr(), pcnet32_probe(), phantom_add_macaddr(), phantom_del_macaddr(), phantom_get_macaddr(), prism2_probe(), smc9000_probe(), smsc95xx_fetch_mac(), smsc95xx_vm3_fetch_mac(), smscusb_eeprom_fetch_mac(), smscusb_fdt_fetch_mac(), smscusb_otp_fetch_mac(), stp_rx(), t595_probe(), t5x9_probe(), tlan_probe(), tulip_probe(), txnic_lmac_probe(), undinet_probe(), vxge_probe(), w89c840_probe(), wpa_derive_ptk(), xsmp_rx_xve_install(), and xve_create().

eth_mc_hash()

int eth_mc_hash	(	unsigned int	af,
		const void *	net_addr,
		void *	ll_addr )

Hash multicast address.

Parameters

af	Address family
net_addr	Network-layer address
ll_addr	Link-layer address to fill in

Return values

rc	Return status code

Definition at line 195 of file ethernet.c.

                                                                         {
        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;
        }
}

References AF_INET, AF_INET6, ENOTSUP, and memcpy().

eth_eth_addr()

int eth_eth_addr	(	const void *	ll_addr,
		void *	eth_addr )

Generate Ethernet-compatible compressed link-layer address.

Parameters

ll_addr	Link-layer address
eth_addr	Ethernet-compatible address to fill in

Definition at line 224 of file ethernet.c.

                                                         {
        memcpy ( eth_addr, ll_addr, ETH_ALEN );
        return 0;
}

References ETH_ALEN, and memcpy().

eth_eui64()

int eth_eui64	(	const void *	ll_addr,
		void *	eui64 )

Generate EUI-64 address.

Parameters

ll_addr	Link-layer address
eui64	EUI-64 address to fill in

Return values

rc	Return status code

Definition at line 236 of file ethernet.c.

                                                   {
 
        memcpy ( ( eui64 + 0 ), ( ll_addr + 0 ), 3 );
        memcpy ( ( eui64 + 5 ), ( ll_addr + 3 ), 3 );
        *( ( uint16_t * ) ( eui64 + 3 ) ) = htons ( 0xfffe );
        return 0;
}

References htons, and memcpy().

alloc_etherdev()

struct net_device * alloc_etherdev

(

size_t

priv_size

)

Allocate Ethernet device.

Parameters

priv_size

Size of driver private data

Return values

netdev

Network device, or NULL

Definition at line 266 of file ethernet.c.

                                                        {
        struct net_device *netdev;
 
        netdev = alloc_netdev ( priv_size );
        if ( netdev ) {
                netdev->ll_protocol = &ethernet_protocol;
                netdev->ll_broadcast = eth_broadcast;
                netdev->max_pkt_len = ETH_FRAME_LEN;
                netdev->mtu = ETH_MAX_MTU;
        }
        return netdev;
}

References alloc_netdev(), eth_broadcast, ETH_FRAME_LEN, ETH_MAX_MTU, and netdev.

Referenced by a3c90x_probe(), af_packet_nic_probe(), alloc_rndis(), atl1e_probe(), atl_probe(), axge_probe(), b44_probe(), bnxt_init_one(), cgem_probe(), dm96xx_probe(), dwmac_probe(), ecm_probe(), efab_probe(), ena_probe(), eoib_create(), exanic_probe_port(), flexboot_nodnic_register_netdev(), forcedeth_probe(), gve_probe(), hermon_probe(), hunt_probe(), ice_probe(), icplus_probe(), ifec_pci_probe(), igbvf_probe(), intel_probe(), intelx_probe(), intelxl_probe(), intelxlvf_probe(), intelxvf_probe(), iphone_probe(), jme_probe(), lan78xx_probe(), legacy_probe(), mnpnet_start(), myri10ge_pci_probe(), myson_probe(), natsemi_probe(), ncm_probe(), netfront_probe(), pcnet32_probe(), phantom_probe(), pnic_probe(), rdc_probe(), realtek_probe(), rhine_probe(), sis190_init_board(), skeleton_probe(), skge_devinit(), sky2_init_netdev(), slirp_probe(), smsc75xx_probe(), smsc95xx_probe(), snpnet_start(), tap_probe(), testnet_okx(), tg3_init_one(), txnic_alloc(), undinet_probe(), velocity_probe(), virtio_net_probe(), vlan_create(), vmxnet3_probe(), and vxge_device_register().

REQUIRING_SYMBOL()

REQUIRING_SYMBOL

(

ethernet_protocol

)

REQUIRE_OBJECT()

REQUIRE_OBJECT

(

config_ethernet

)

Variable Documentation

eth_broadcast

uint8_t eth_broadcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }

Ethernet broadcast MAC address.

Definition at line 48 of file ethernet.c.

{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };

Referenced by alloc_etherdev(), alloc_ipoibdev(), ath9k_init_misc(), ice_probe(), ipoib_complete_recv(), net80211_alloc(), and net80211_probe_step().

__ll_protocol

struct ll_protocol ethernet_protocol __ll_protocol

Initial value:

                 = {
        .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,
}

Ethernet protocol.

Definition at line 245 of file ethernet.c.

                                                   {
        .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,
};