Link Layer Address Handling

Overview

The link layer addresses are set for network interfaces so that L2 connectivity works correctly in the network stack. Typically the link layer addresses are 6 bytes long like in Ethernet but for IEEE 802.15.4 the link layer address length is 8 bytes.

API Reference

group net_linkaddr

Network link address library.

Defines

NET_LINK_ADDR_MAX_LENGTH

Maximum length of the link address

Enums

enum net_link_type

Type of the link address. This indicates the network technology that this address is used in. Note that in order to save space we store the value into a uint8_t variable, so please do not introduce any values > 255 in this enum.

Values:

enumerator NET_LINK_UNKNOWN = 0

Unknown link address type.

enumerator NET_LINK_IEEE802154

IEEE 802.15.4 link address.

enumerator NET_LINK_BLUETOOTH

Bluetooth IPSP link address.

enumerator NET_LINK_ETHERNET

Ethernet link address.

enumerator NET_LINK_DUMMY

Dummy link address. Used in testing apps and loopback support.

enumerator NET_LINK_CANBUS_RAW

CANBUS link address.

Functions

static inline bool net_linkaddr_cmp(struct net_linkaddr *lladdr1, struct net_linkaddr *lladdr2)

Compare two link layer addresses.

Return

True if the addresses are the same, false otherwise.

Parameters

• lladdr1: Pointer to a link layer address

• lladdr2: Pointer to a link layer address

static inline int net_linkaddr_set(struct net_linkaddr_storage *lladdr_store, uint8_t *new_addr, uint8_t new_len)

Set the member data of a link layer address storage structure.

Parameters

• lladdr_store: The link address storage structure to change.

• new_addr: Array of bytes containing the link address.

• new_len: Length of the link address array. This value should always be <= NET_LINK_ADDR_MAX_LENGTH.

struct net_linkaddr

#include <net_linkaddr.h>

Hardware link address structure.

Used to hold the link address information

Public Members

uint8_t *addr

The array of byte representing the address

uint8_t len

Length of that address array

uint8_t type

What kind of address is this for

struct net_linkaddr_storage

#include <net_linkaddr.h>

Hardware link address structure.

Used to hold the link address information. This variant is needed when we have to store the link layer address.

Note that you cannot cast this to net_linkaddr as uint8_t * is handled differently than uint8_t addr[] and the fields are purposely in different order.

Public Members

uint8_t type

What kind of address is this for

uint8_t len

The real length of the ll address.

uint8_t addr[6]

The array of bytes representing the address