Product Documentation for Devicescape Secure Wireless Client

API Reference Documentation for Devicescape Secure Wireless Client

l2_packet.h File Reference

WPA Supplicant - Layer2 packet interface definition. More...

Data Structures
struct	l2_ethhdr
Defines
#define	MAC2STR(a)   (a)[0], (a)[1], (a)[2], (a)[3], (a)[4], (a)[5]
#define	MACSTR   "%02x:%02x:%02x:%02x:%02x:%02x"
#define	ETH_P_EAPOL   0x888e
#define	ETH_P_RSN_PREAUTH   0x88c7
Functions
l2_packet_data *	l2_packet_init (const char *ifname, const u8 *own_addr, unsigned short protocol, void(*rx_callback)(void *ctx, const u8 *src_addr, const u8 *buf, size_t len), void *rx_callback_ctx, int l2_hdr)
	Initialize l2_packet interface.
void	l2_packet_deinit (struct l2_packet_data *l2)
	Deinitialize l2_packet interface.
int	l2_packet_get_own_addr (struct l2_packet_data *l2, u8 *addr)
	Get own layer 2 address.
int	l2_packet_send (struct l2_packet_data *l2, const u8 *dst_addr, u16 proto, const u8 *buf, size_t len)
	Send a packet.
int	l2_packet_get_ip_addr (struct l2_packet_data *l2, char *buf, size_t len)
	Get the current IP address from the interface.
void	l2_packet_notify_auth_start (struct l2_packet_data *l2)
	Notify l2_packet about start of authentication.
Variables
l2_ethhdr	STRUCT_PACKED

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Detailed Description

WPA Supplicant - Layer2 packet interface definition.

This file defines an interface for layer 2 (link layer) packet sending and receiving. l2_packet_linux.c is one implementation for such a layer 2 implementation using Linux packet sockets and l2_packet_pcap.c another one using libpcap and libdnet. When porting wpa_supplicant to other operating systems, a new l2_packet implementation may need to be added.

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Function Documentation

void l2_packet_deinit (  struct l2_packet_data *  l2  )

Deinitialize l2_packet interface. Parameters: l2  Pointer to internal l2_packet data from l2_packet_init()

int l2_packet_get_ip_addr (  struct l2_packet_data *  l2, char *  buf, size_t  len )

Get the current IP address from the interface. Parameters: l2  Pointer to internal l2_packet data from l2_packet_init() buf  Buffer for the IP address in text format len  Maximum buffer length Returns: 0 on success, -1 on failure This function can be used to get the current IP address from the interface bound to the l2_packet. This is mainly for status information and the IP address will be stored as an ASCII string. This function is not essential for wpa_supplicant operation, so full implementation is not required. l2_packet implementation will need to define the function, but it can return -1 if the IP address information is not available.

int l2_packet_get_own_addr (  struct l2_packet_data *  l2, u8 *  addr )

Get own layer 2 address. Parameters: l2  Pointer to internal l2_packet data from l2_packet_init() addr  Buffer for the own address (6 bytes) Returns: 0 on success, -1 on failure

struct l2_packet_data* l2_packet_init (  const char *  ifname, const u8 *  own_addr, unsigned short  protocol, void(*)(void *ctx, const u8 *src_addr, const u8 *buf, size_t len)  rx_callback, void *  rx_callback_ctx, int  l2_hdr )

Initialize l2_packet interface. Parameters: ifname  Interface name own_addr  Optional own MAC address if available from driver interface or NULL if not available protocol  Ethernet protocol number in host byte order rx_callback  Callback function that will be called for each received packet rx_callback_ctx  Callback data (ctx) for calls to rx_callback() l2_hdr  1 = include layer 2 header, 0 = do not include header Returns: Pointer to internal data or NULL on failure rx_callback function will be called with src_addr pointing to the source address (MAC address) of the the packet. If l2_hdr is set to 0, buf points to len bytes of the payload after the layer 2 header and similarly, TX buffers start with payload. This behavior can be changed by setting l2_hdr=1 to include the layer 2 header in the data buffer.

void l2_packet_notify_auth_start (  struct l2_packet_data *  l2  )

Notify l2_packet about start of authentication. Parameters: l2  Pointer to internal l2_packet data from l2_packet_init() This function is called when authentication is expected to start, e.g., when association has been completed, in order to prepare l2_packet implementation for EAPOL frames. This function is used mainly if the l2_packet code needs to do polling in which case it can increasing polling frequency. This can also be an empty function if the l2_packet implementation does not benefit from knowing about the starting authentication.

int l2_packet_send (  struct l2_packet_data *  l2, const u8 *  dst_addr, u16  proto, const u8 *  buf, size_t  len )

Send a packet. Parameters: l2  Pointer to internal l2_packet data from l2_packet_init() dst_addr  Destination address for the packet (only used if l2_hdr == 0) proto  Protocol/ethertype for the packet in host byte order (only used if l2_hdr == 0) buf  Packet contents to be sent; including layer 2 header if l2_hdr was set to 1 in l2_packet_init() call. Otherwise, only the payload of the packet is included. len  Length of the buffer (including l2 header only if l2_hdr == 1) Returns: >=0 on success, <0 on failure

 

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