iPXE
Functions | Variables
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)
 
static int eth_is_llc_packet (struct ethhdr *ethhdr)
 Check if Ethernet packet has an 802.3 LLC header. More...
 
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. More...
 
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. More...
 
void eth_init_addr (const void *hw_addr, void *ll_addr)
 Initialise Ethernet address. More...
 
void eth_random_addr (void *hw_addr)
 Generate random Ethernet address. More...
 
const char * eth_ntoa (const void *ll_addr)
 Transcribe Ethernet address. More...
 
int eth_mc_hash (unsigned int af, const void *net_addr, void *ll_addr)
 Hash multicast address. More...
 
int eth_eth_addr (const void *ll_addr, void *eth_addr)
 Generate Ethernet-compatible compressed link-layer address. More...
 
int eth_eui64 (const void *ll_addr, void *eui64)
 Generate EUI-64 address. More...
 
struct net_devicealloc_etherdev (size_t priv_size)
 Allocate Ethernet device. More...
 
 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. More...
 
struct ll_protocol ethernet_protocol __ll_protocol
 Ethernet protocol. More...
 

Detailed Description

Ethernet protocol.

Definition in file ethernet.c.

Function Documentation

◆ FILE_LICENCE()

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL  )

◆ eth_is_llc_packet()

static int eth_is_llc_packet ( struct ethhdr ethhdr)
inlinestatic

Check if Ethernet packet has an 802.3 LLC header.

Parameters
ethhdrEthernet header
Return values
is_llcPacket has 802.3 LLC header

Definition at line 55 of file ethernet.c.

55  {
56  uint8_t len_msb;
57 
58  /* Check if the protocol field contains a value short enough
59  * to be a frame length. The slightly convoluted form of the
60  * comparison is designed to reduce to a single x86
61  * instruction.
62  */
63  len_msb = *( ( uint8_t * ) &ethhdr->h_protocol );
64  return ( len_msb < 0x06 );
65 }
uint16_t h_protocol
Protocol ID.
Definition: if_ether.h:36
unsigned char uint8_t
Definition: stdint.h:10
An Ethernet link-layer header.
Definition: if_ether.h:30

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
netdevNetwork device
iobufI/O buffer
ll_destLink-layer destination address
ll_sourceSource link-layer address
net_protoNetwork-layer protocol, in network-byte order
Return values
rcReturn status code

Definition at line 77 of file ethernet.c.

79  {
80  struct ethhdr *ethhdr = iob_push ( iobuf, sizeof ( *ethhdr ) );
81 
82  /* Build Ethernet header */
83  memcpy ( ethhdr->h_dest, ll_dest, ETH_ALEN );
84  memcpy ( ethhdr->h_source, ll_source, ETH_ALEN );
85  ethhdr->h_protocol = net_proto;
86 
87  return 0;
88 }
uint16_t h_protocol
Protocol ID.
Definition: if_ether.h:36
#define iob_push(iobuf, len)
Definition: iobuf.h:80
uint8_t h_dest[ETH_ALEN]
Destination MAC address.
Definition: if_ether.h:32
void * memcpy(void *dest, const void *src, size_t len) __nonnull
uint8_t h_source[ETH_ALEN]
Source MAC address.
Definition: if_ether.h:34
#define ETH_ALEN
Definition: if_ether.h:8
An Ethernet link-layer header.
Definition: if_ether.h:30

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

◆ 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
netdevNetwork device
iobufI/O buffer
Return values
ll_destLink-layer destination address
ll_sourceSource link-layer address
net_protoNetwork-layer protocol, in network-byte order
flagsPacket flags
rcReturn status code

Definition at line 101 of file ethernet.c.

103  {
104  struct ethhdr *ethhdr = iobuf->data;
105  uint16_t *llc_proto;
106 
107  /* Sanity check. While in theory we could receive a one-byte
108  * packet, this will never happen in practice and performing
109  * the combined length check here avoids the need for an
110  * additional comparison if we detect an LLC frame.
111  */
112  if ( iob_len ( iobuf ) < ( sizeof ( *ethhdr ) + sizeof ( *llc_proto ))){
113  DBG ( "Ethernet packet too short (%zd bytes)\n",
114  iob_len ( iobuf ) );
115  return -EINVAL;
116  }
117 
118  /* Strip off Ethernet header */
119  iob_pull ( iobuf, sizeof ( *ethhdr ) );
120 
121  /* Fill in required fields */
122  *ll_dest = ethhdr->h_dest;
123  *ll_source = ethhdr->h_source;
124  *net_proto = ethhdr->h_protocol;
126  LL_MULTICAST : 0 ) |
128  LL_BROADCAST : 0 ) );
129 
130  /* If this is an LLC frame (with a length in place of the
131  * protocol field), then use the next two bytes (which happen
132  * to be the LLC DSAP and SSAP) as the protocol. This allows
133  * for minimal-overhead support for receiving (rare) LLC
134  * frames, without requiring a full LLC protocol layer.
135  */
136  if ( eth_is_llc_packet ( ethhdr ) ) {
137  llc_proto = iobuf->data;
138  *net_proto = *llc_proto;
139  }
140 
141  return 0;
142 }
#define LL_MULTICAST
Packet is a multicast (including broadcast) packet.
Definition: netdevice.h:105
uint16_t h_protocol
Protocol ID.
Definition: if_ether.h:36
#define iob_pull(iobuf, len)
Definition: iobuf.h:98
#define EINVAL
Invalid argument.
Definition: errno.h:428
unsigned short uint16_t
Definition: stdint.h:11
uint8_t h_dest[ETH_ALEN]
Destination MAC address.
Definition: if_ether.h:32
static int eth_is_llc_packet(struct ethhdr *ethhdr)
Check if Ethernet packet has an 802.3 LLC header.
Definition: ethernet.c:55
static int is_multicast_ether_addr(const void *addr)
Check if Ethernet address is a multicast address.
Definition: ethernet.h:37
static size_t iob_len(struct io_buffer *iobuf)
Calculate length of data in an I/O buffer.
Definition: iobuf.h:151
uint8_t h_source[ETH_ALEN]
Source MAC address.
Definition: if_ether.h:34
#define LL_BROADCAST
Packet is a broadcast packet.
Definition: netdevice.h:108
void * data
Start of data.
Definition: iobuf.h:44
static int is_broadcast_ether_addr(const void *addr)
Check if Ethernet address is the broadcast address.
Definition: ethernet.h:61
#define DBG(...)
Print a debugging message.
Definition: compiler.h:498
An Ethernet link-layer header.
Definition: if_ether.h:30
uint8_t flags
Flags.
Definition: ena.h:18

References 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, and LL_MULTICAST.

Referenced by undinet_transmit().

◆ eth_init_addr()

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

Initialise Ethernet address.

Parameters
hw_addrHardware address
ll_addrLink-layer address

Definition at line 150 of file ethernet.c.

150  {
151  memcpy ( ll_addr, hw_addr, ETH_ALEN );
152 }
void * memcpy(void *dest, const void *src, size_t len) __nonnull
#define ETH_ALEN
Definition: if_ether.h:8

References ETH_ALEN, and memcpy().

◆ eth_random_addr()

void eth_random_addr ( void *  hw_addr)

Generate random Ethernet address.

Parameters
hw_addrGenerated hardware address

Definition at line 159 of file ethernet.c.

159  {
160  uint8_t *addr = hw_addr;
161  unsigned int i;
162 
163  for ( i = 0 ; i < ETH_ALEN ; i++ )
164  addr[i] = random();
165  addr[0] &= ~0x01; /* Clear multicast bit */
166  addr[0] |= 0x02; /* Set locally-assigned bit */
167 }
long int random(void)
Generate a pseudo-random number between 0 and 2147483647L or 2147483562?
Definition: random.c:30
u32 addr
Definition: sky2.h:8
unsigned char uint8_t
Definition: stdint.h:10
#define ETH_ALEN
Definition: if_ether.h:8

References addr, ETH_ALEN, and random().

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

◆ eth_ntoa()

const char* eth_ntoa ( const void *  ll_addr)

Transcribe Ethernet address.

Parameters
ll_addrLink-layer address
Return values
stringLink-layer address in human-readable format

Definition at line 175 of file ethernet.c.

175  {
176  static char buf[18]; /* "00:00:00:00:00:00" */
177  const uint8_t *eth_addr = ll_addr;
178 
179  sprintf ( buf, "%02x:%02x:%02x:%02x:%02x:%02x",
180  eth_addr[0], eth_addr[1], eth_addr[2],
181  eth_addr[3], eth_addr[4], eth_addr[5] );
182  return buf;
183 }
#define sprintf(buf, fmt,...)
Write a formatted string to a buffer.
Definition: stdio.h:36
unsigned char uint8_t
Definition: stdint.h:10

References sprintf.

Referenced by amd8111e_get_mac_address(), b44_probe(), bnx2_probe(), bofm_en(), bofm_test(), corkscrew_probe1(), cs89x0_probe(), davicom_probe(), dmfe_probe(), 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(), hermon_bofm_harvest(), hermon_bofm_update(), ibft_fill_nic(), intel_fetch_mac(), intel_fetch_mac_eeprom(), intelvf_mbox_reset(), intelx_try_fetch_mac(), intelxl_fetch_mac(), 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(), virtnet_probe_legacy(), virtnet_probe_modern(), 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
afAddress family
net_addrNetwork-layer address
ll_addrLink-layer address to fill in
Return values
rcReturn status code

Definition at line 193 of file ethernet.c.

193  {
194  const uint8_t *net_addr_bytes = net_addr;
195  uint8_t *ll_addr_bytes = ll_addr;
196 
197  switch ( af ) {
198  case AF_INET:
199  ll_addr_bytes[0] = 0x01;
200  ll_addr_bytes[1] = 0x00;
201  ll_addr_bytes[2] = 0x5e;
202  ll_addr_bytes[3] = net_addr_bytes[1] & 0x7f;
203  ll_addr_bytes[4] = net_addr_bytes[2];
204  ll_addr_bytes[5] = net_addr_bytes[3];
205  return 0;
206  case AF_INET6:
207  ll_addr_bytes[0] = 0x33;
208  ll_addr_bytes[1] = 0x33;
209  memcpy ( &ll_addr_bytes[2], &net_addr_bytes[12], 4 );
210  return 0;
211  default:
212  return -ENOTSUP;
213  }
214 }
#define AF_INET6
IPv6 Internet addresses.
Definition: socket.h:64
#define ENOTSUP
Operation not supported.
Definition: errno.h:589
void * memcpy(void *dest, const void *src, size_t len) __nonnull
unsigned char uint8_t
Definition: stdint.h:10
#define AF_INET
IPv4 Internet addresses.
Definition: socket.h:63

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_addrLink-layer address
eth_addrEthernet-compatible address to fill in

Definition at line 222 of file ethernet.c.

222  {
223  memcpy ( eth_addr, ll_addr, ETH_ALEN );
224  return 0;
225 }
void * memcpy(void *dest, const void *src, size_t len) __nonnull
#define ETH_ALEN
Definition: if_ether.h:8

References ETH_ALEN, and memcpy().

◆ eth_eui64()

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

Generate EUI-64 address.

Parameters
ll_addrLink-layer address
eui64EUI-64 address to fill in
Return values
rcReturn status code

Definition at line 234 of file ethernet.c.

234  {
235 
236  memcpy ( ( eui64 + 0 ), ( ll_addr + 0 ), 3 );
237  memcpy ( ( eui64 + 5 ), ( ll_addr + 3 ), 3 );
238  *( ( uint16_t * ) ( eui64 + 3 ) ) = htons ( 0xfffe );
239  return 0;
240 }
unsigned short uint16_t
Definition: stdint.h:11
void * memcpy(void *dest, const void *src, size_t len) __nonnull
#define htons(value)
Definition: byteswap.h:135

References htons, and memcpy().

◆ alloc_etherdev()

struct net_device* alloc_etherdev ( size_t  priv_size)

Allocate Ethernet device.

Parameters
priv_sizeSize of driver private data
Return values
netdevNetwork device, or NULL

Definition at line 264 of file ethernet.c.

264  {
265  struct net_device *netdev;
266 
267  netdev = alloc_netdev ( priv_size );
268  if ( netdev ) {
269  netdev->ll_protocol = &ethernet_protocol;
273  }
274  return netdev;
275 }
size_t mtu
Maximum transmission unit length.
Definition: netdevice.h:409
uint8_t eth_broadcast[ETH_ALEN]
Ethernet broadcast MAC address.
Definition: ethernet.c:47
const uint8_t * ll_broadcast
Link-layer broadcast address.
Definition: netdevice.h:383
#define ETH_MAX_MTU
Definition: if_ether.h:14
struct net_device * alloc_netdev(size_t priv_len)
Allocate network device.
Definition: netdevice.c:622
#define ETH_FRAME_LEN
Definition: if_ether.h:11
static struct net_device * netdev
Definition: gdbudp.c:52
A network device.
Definition: netdevice.h:348
size_t max_pkt_len
Maximum packet length.
Definition: netdevice.h:403
struct ll_protocol * ll_protocol
Link-layer protocol.
Definition: netdevice.h:366

References alloc_netdev(), eth_broadcast, ETH_FRAME_LEN, ETH_MAX_MTU, net_device::ll_broadcast, net_device::ll_protocol, net_device::max_pkt_len, net_device::mtu, and netdev.

Referenced by a3c90x_probe(), alloc_rndis(), atl1e_probe(), axge_probe(), b44_probe(), dm96xx_probe(), ecm_probe(), efab_probe(), ena_probe(), eoib_create(), exanic_probe_port(), flexboot_nodnic_register_netdev(), forcedeth_probe(), hermon_probe(), hunt_probe(), icplus_probe(), ifec_pci_probe(), igbvf_probe(), intel_probe(), intelx_probe(), intelxl_probe(), intelxlvf_probe(), intelxvf_probe(), jme_probe(), lan78xx_probe(), legacy_probe(), myri10ge_pci_probe(), myson_probe(), natsemi_probe(), ncm_probe(), netfront_probe(), pcnet32_probe(), phantom_probe(), pnic_probe(), realtek_probe(), rhine_probe(), sis190_init_board(), skeleton_probe(), skge_devinit(), sky2_init_netdev(), smsc75xx_probe(), smsc95xx_probe(), snpnet_start(), tg3_init_one(), txnic_alloc(), undinet_probe(), velocity_probe(), virtnet_probe_legacy(), virtnet_probe_modern(), 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 47 of file ethernet.c.

Referenced by alloc_etherdev(), alloc_ipoibdev(), ath9k_init_misc(), 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,
}
int eth_eth_addr(const void *ll_addr, void *eth_addr)
Generate Ethernet-compatible compressed link-layer address.
Definition: ethernet.c:222
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.
Definition: ethernet.c:77
void eth_init_addr(const void *hw_addr, void *ll_addr)
Initialise Ethernet address.
Definition: ethernet.c:150
int eth_eui64(const void *ll_addr, void *eui64)
Generate EUI-64 address.
Definition: ethernet.c:234
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.
Definition: ethernet.c:101
#define ETH_HLEN
Definition: if_ether.h:9
int eth_mc_hash(unsigned int af, const void *net_addr, void *ll_addr)
Hash multicast address.
Definition: ethernet.c:193
const char * eth_ntoa(const void *ll_addr)
Transcribe Ethernet address.
Definition: ethernet.c:175
#define ETH_ALEN
Definition: if_ether.h:8
#define ARPHRD_ETHER
Ethernet 10Mbps.
Definition: if_arp.h:16
#define htons(value)
Definition: byteswap.h:135

Ethernet protocol.

Definition at line 243 of file ethernet.c.