eap_common.c File Reference

EAP common peer/server definitions. More...

#include "includes.h"
#include "common.h"
#include "eap_defs.h"
#include "eap_common.h"

Functions
int	eap_hdr_len_valid (const struct wpabuf *msg, size_t min_payload)
	Validate EAP header length field. More...
const u8 *	eap_hdr_validate (int vendor, EapType eap_type, const struct wpabuf *msg, size_t *plen)
	Validate EAP header. More...
struct wpabuf *	eap_msg_alloc (int vendor, EapType type, size_t payload_len, u8 code, u8 identifier)
	Allocate a buffer for an EAP message. More...
void	eap_update_len (struct wpabuf *msg)
	Update EAP header length. More...
u8	eap_get_id (const struct wpabuf *msg)
	Get EAP Identifier from wpabuf. More...
EapType	eap_get_type (const struct wpabuf *msg)
	Get EAP Type from wpabuf. More...

Detailed Description

EAP common peer/server definitions.

Function Documentation

u8 eap_get_id

(

const struct wpabuf *

msg

)

Get EAP Identifier from wpabuf.

Parameters

msg	Buffer starting with an EAP header

Returns

The Identifier field from the EAP header

EapType eap_get_type

(

const struct wpabuf *

msg

)

Get EAP Type from wpabuf.

Parameters

msg	Buffer starting with an EAP header

Returns

The EAP Type after the EAP header

int eap_hdr_len_valid	(	const struct wpabuf *	msg,
		size_t	min_payload
	)

Validate EAP header length field.

Parameters

msg	EAP frame (starting with EAP header)
min_payload	Minimum payload length needed

Returns

1 for valid header, 0 for invalid

This is a helper function that does minimal validation of EAP messages. The length field is verified to be large enough to include the header and not too large to go beyond the end of the buffer.

const u8* eap_hdr_validate	(	int	vendor,
		EapType	eap_type,
		const struct wpabuf *	msg,
		size_t *	plen
	)

Validate EAP header.

Parameters

vendor	Expected EAP Vendor-Id (0 = IETF)
eap_type	Expected EAP type number
msg	EAP frame (starting with EAP header)
plen	Pointer to variable to contain the returned payload length

Returns

Pointer to EAP payload (after type field), or NULL on failure

This is a helper function for EAP method implementations. This is usually called in the beginning of struct eap_method::process() function to verify that the received EAP request packet has a valid header. This function is able to process both legacy and expanded EAP headers and in most cases, the caller can just use the returned payload pointer (into *plen) for processing the payload regardless of whether the packet used the expanded EAP header or not.

struct wpabuf* eap_msg_alloc	(	int	vendor,
		EapType	type,
		size_t	payload_len,
		u8	code,
		u8	identifier
	)

Allocate a buffer for an EAP message.

Parameters

vendor	Vendor-Id (0 = IETF)
type	EAP type
payload_len	Payload length in bytes (data after Type)
code	Message Code (EAP_CODE_*)
identifier	Identifier

Returns

Pointer to the allocated message buffer or NULL on error

This function can be used to allocate a buffer for an EAP message and fill in the EAP header. This function is automatically using expanded EAP header if the selected Vendor-Id is not IETF. In other words, most EAP methods do not need to separately select which header type to use when using this function to allocate the message buffers. The returned buffer has room for payload_len bytes and has the EAP header and Type field already filled in.

void eap_update_len

(

struct wpabuf *

msg

)

Update EAP header length.

Parameters

msg	EAP message from eap_msg_alloc

This function updates the length field in the EAP header to match with the current length for the buffer. This allows eap_msg_alloc() to be used to allocate a larger buffer than the exact message length (e.g., if exact message length is not yet known).