Implementation of the DHCPv4 protocol. More...

#include <freeradius-devel/util/pcap.h>
#include <freeradius-devel/util/packet.h>
#include <freeradius-devel/protocol/dhcpv4/rfc2131.h>

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Data Structures
struct	dhcp_packet_t

struct	fr_dhcpv4_attr_flags_t

struct	fr_dhcpv4_ctx_t
	Used as the decoder ctx. More...

Macros
#define	DEFAULT_PACKET_SIZE (300)

#define	DHCP_CHADDR_LEN (16)

#define	DHCP_FILE_FIELD (1)

#define	DHCP_FILE_LEN (128)

#define	DHCP_OPTION_FIELD (0)

#define	DHCP_OPTION_MAGIC_NUMBER (0x63825363U)

#define	DHCP_PACK_OPTION1(x, y) ((x) \| ((y) << 8))

#define	DHCP_SNAME_FIELD (2)

#define	DHCP_SNAME_LEN (64)

#define	DHCP_UNPACK_OPTION1(x) (((x) & 0xff00) >> 8)

#define	DHCP_VEND_LEN (308)

#define	DHCPV4_MAX_ATTRIBUTES 255

#define	ETH_ADDR_LEN 6

#define	FR_DHCP_PACKET_CODE_VALID(_code) (((_code) > 0) && ((_code) < FR_DHCP_CODE_MAX))

#define	INADDR_BROADCAST INADDR_NONE

#define	MAX_PACKET_SIZE (1500 - 40)

#define	MIN_PACKET_SIZE (244)

Enumerations
enum	fr_dhcpv4_attr_flags_prefix_t : int8_t { DHCPV4_FLAG_PREFIX_INVALID = -1 , DHCPV4_FLAG_PREFIX_NONE = 0 , DHCPV4_FLAG_PREFIX_BITS = 1 , DHCPV4_FLAG_PREFIX_SPLIT = 2 }

enum	fr_dhcpv4_packet_code_t : uint16_t { FR_DHCP_INVALID = 0 , FR_DHCP_DISCOVER = 1 , FR_DHCP_OFFER = 2 , FR_DHCP_REQUEST = 3 , FR_DHCP_DECLINE = 4 , FR_DHCP_ACK = 5 , FR_DHCP_NAK = 6 , FR_DHCP_RELEASE = 7 , FR_DHCP_INFORM = 8 , FR_DHCP_FORCE_RENEW = 9 , FR_DHCP_LEASE_QUERY = 10 , FR_DHCP_LEASE_UNASSIGNED = 11 , FR_DHCP_LEASE_UNKNOWN = 12 , FR_DHCP_LEASE_ACTIVE = 13 , FR_DHCP_BULK_LEASE_QUERY = 14 , FR_DHCP_LEASE_QUERY_DONE = 15 , FR_DHCP_CODE_MAX = 16 , FR_DHCP_DO_NOT_RESPOND = 256 }

Functions
fr_cmp_ret_t	fr_dhcpv4_attr_cmp (void const a, void const b)

static fr_dhcpv4_attr_flags_t const *	fr_dhcpv4_attr_flags (fr_dict_attr_t const *da)
	Return DHCPv4-specific flags for a given attribute.

int	fr_dhcpv4_decode (TALLOC_CTX ctx, fr_pair_list_t out, uint8_t const data, size_t data_len, unsigned int code)

ssize_t	fr_dhcpv4_decode_foreign (TALLOC_CTX ctx, fr_pair_list_t out, uint8_t const *data, size_t data_len)

ssize_t	fr_dhcpv4_decode_option (TALLOC_CTX ctx, fr_pair_list_t out, uint8_t const data, size_t len, void decode_ctx)
	Decode DHCP option.

ssize_t	fr_dhcpv4_encode (uint8_t buffer, size_t buflen, dhcp_packet_t original, fr_dhcpv4_packet_code_t code, uint32_t xid, fr_pair_list_t *vps)

ssize_t	fr_dhcpv4_encode_dbuff (fr_dbuff_t dbuff, dhcp_packet_t original, fr_dhcpv4_packet_code_t code, uint32_t xid, fr_pair_list_t *vps)

ssize_t	fr_dhcpv4_encode_foreign (fr_dbuff_t dbuff, fr_pair_list_t const list)

ssize_t	fr_dhcpv4_encode_option (fr_dbuff_t dbuff, fr_dcursor_t cursor, void *encode_ctx)
	Encode a DHCP option and any sub-options.

static bool	fr_dhcpv4_flag_dns_label (fr_dict_attr_t const *da)

static bool	fr_dhcpv4_flag_exists (fr_dict_attr_t const *da)

static fr_dhcpv4_attr_flags_prefix_t	fr_dhcpv4_flag_prefix (fr_dict_attr_t const *da)

static bool	fr_dhcpv4_flag_prefix_bits (fr_dict_attr_t const *da)

static bool	fr_dhcpv4_flag_prefix_split (fr_dict_attr_t const *da)

void	fr_dhcpv4_global_free (void)

int	fr_dhcpv4_global_init (void)
	Resolve/cache attributes in the DHCP dictionary.

bool	fr_dhcpv4_is_encodable (void const item, void const uctx)

void *	fr_dhcpv4_next_encodable (fr_dcursor_t cursor, void to_eval, void *uctx)
	DHCPV4-specific iterator.

bool	fr_dhcpv4_ok (uint8_t const data, size_t data_len, uint8_t message_type, uint32_t *xid)
	Check received DHCP request is valid and build fr_packet_t structure if it is.

fr_packet_t *	fr_dhcpv4_packet_alloc (uint8_t const *data, size_t data_len)

int	fr_dhcpv4_packet_encode (fr_packet_t packet, fr_pair_list_t list)

uint8_t const *	fr_dhcpv4_packet_get_option (dhcp_packet_t const packet, size_t packet_size, fr_dict_attr_t const da)
	Retrieve a DHCP option from a raw packet buffer.

void	fr_dhcpv4_print_hex (FILE fp, uint8_t const packet, size_t packet_len)
	Print a raw DHCP packet as hex.

fr_packet_t *	fr_dhcpv4_udp_packet_recv (int sockfd)
	Receive DHCP packet using a connectionless UDP socket.

int	fr_dhcpv4_udp_packet_send (fr_packet_t *packet)
	Send DHCP packet using a connectionless UDP socket.

Variables
fr_dict_attr_t const **	dhcp_header_attrs []

size_t	dhcp_header_attrs_len

int	dhcp_header_sizes []

char const *	dhcp_message_types [FR_DHCP_CODE_MAX]

uint8_t	eth_bcast [ETH_ADDR_LEN]

fr_dict_protocol_t	libfreeradius_dhcpv4_dict_protocol

Detailed Description

Implementation of the DHCPv4 protocol.

Id: e9b71fe622406e0b165b8e1db5a5ae97853e058f

Copyright: 2008 The FreeRADIUS server project; 2008 Alan DeKok (aland.nosp@m.@dep.nosp@m.loyin.nosp@m.grad.nosp@m.ius.c.nosp@m.om)

Definition in file dhcpv4.h.

Data Structure Documentation

◆ dhcp_packet_t

struct dhcp_packet_t

Definition at line 66 of file dhcpv4.h.

Data Fields
uint8_t	chaddr[DHCP_CHADDR_LEN]
uint32_t	ciaddr
uint8_t	file[DHCP_FILE_LEN]
uint16_t	flags
uint32_t	giaddr
uint8_t	hlen
uint8_t	hops
uint8_t	htype
uint8_t	opcode
uint32_t	option_format
uint8_t	options[DHCP_VEND_LEN]
uint16_t	secs
uint32_t	siaddr
uint8_t	sname[DHCP_SNAME_LEN]
uint32_t	xid
uint32_t	yiaddr

◆ fr_dhcpv4_attr_flags_t

struct fr_dhcpv4_attr_flags_t

Definition at line 146 of file dhcpv4.h.

Data Fields
bool	dns_label
bool	exists
fr_dhcpv4_attr_flags_prefix_t	prefix

◆ fr_dhcpv4_ctx_t

struct fr_dhcpv4_ctx_t

Used as the decoder ctx.

Definition at line 134 of file dhcpv4.h.

Collaboration diagram for fr_dhcpv4_ctx_t:

Data Fields
fr_dict_attr_t const *	root
TALLOC_CTX *	tmp_ctx	for temporary things cleaned up during decoding

Macro Definition Documentation

◆ DEFAULT_PACKET_SIZE

#define DEFAULT_PACKET_SIZE (300)

Definition at line 89 of file dhcpv4.h.

◆ DHCP_CHADDR_LEN

#define DHCP_CHADDR_LEN (16)

Definition at line 37 of file dhcpv4.h.

◆ DHCP_FILE_FIELD

#define DHCP_FILE_FIELD (1)

Definition at line 94 of file dhcpv4.h.

◆ DHCP_FILE_LEN

#define DHCP_FILE_LEN (128)

Definition at line 39 of file dhcpv4.h.

◆ DHCP_OPTION_FIELD

#define DHCP_OPTION_FIELD (0)

Definition at line 93 of file dhcpv4.h.

◆ DHCP_OPTION_MAGIC_NUMBER

#define DHCP_OPTION_MAGIC_NUMBER (0x63825363U)

Definition at line 41 of file dhcpv4.h.

◆ DHCP_PACK_OPTION1

#define DHCP_PACK_OPTION1	(	x,
		y
	)	((x) \| ((y) << 8))

Definition at line 97 of file dhcpv4.h.

◆ DHCP_SNAME_FIELD

#define DHCP_SNAME_FIELD (2)

Definition at line 95 of file dhcpv4.h.

◆ DHCP_SNAME_LEN

#define DHCP_SNAME_LEN (64)

Definition at line 38 of file dhcpv4.h.

◆ DHCP_UNPACK_OPTION1

#define DHCP_UNPACK_OPTION1 ( x ) (((x) & 0xff00) >> 8)

Definition at line 98 of file dhcpv4.h.

◆ DHCP_VEND_LEN

#define DHCP_VEND_LEN (308)

Definition at line 40 of file dhcpv4.h.

◆ DHCPV4_MAX_ATTRIBUTES

#define DHCPV4_MAX_ATTRIBUTES 255

Definition at line 91 of file dhcpv4.h.

◆ ETH_ADDR_LEN

#define ETH_ADDR_LEN 6

Definition at line 103 of file dhcpv4.h.

◆ FR_DHCP_PACKET_CODE_VALID

#define FR_DHCP_PACKET_CODE_VALID ( _code ) (((_code) > 0) && ((_code) < FR_DHCP_CODE_MAX))

Definition at line 64 of file dhcpv4.h.

◆ INADDR_BROADCAST

#define INADDR_BROADCAST INADDR_NONE

Definition at line 101 of file dhcpv4.h.

◆ MAX_PACKET_SIZE

#define MAX_PACKET_SIZE (1500 - 40)

Definition at line 90 of file dhcpv4.h.

◆ MIN_PACKET_SIZE

#define MIN_PACKET_SIZE (244)

Definition at line 88 of file dhcpv4.h.

Enumeration Type Documentation

◆ fr_dhcpv4_attr_flags_prefix_t

enum fr_dhcpv4_attr_flags_prefix_t : int8_t

Enumerator
DHCPV4_FLAG_PREFIX_INVALID
DHCPV4_FLAG_PREFIX_NONE
DHCPV4_FLAG_PREFIX_BITS
DHCPV4_FLAG_PREFIX_SPLIT

Definition at line 139 of file dhcpv4.h.

◆ fr_dhcpv4_packet_code_t

enum fr_dhcpv4_packet_code_t : uint16_t

Enumerator
FR_DHCP_INVALID
FR_DHCP_DISCOVER
FR_DHCP_OFFER
FR_DHCP_REQUEST
FR_DHCP_DECLINE
FR_DHCP_ACK
FR_DHCP_NAK
FR_DHCP_RELEASE
FR_DHCP_INFORM
FR_DHCP_FORCE_RENEW
FR_DHCP_LEASE_QUERY
FR_DHCP_LEASE_UNASSIGNED
FR_DHCP_LEASE_UNKNOWN
FR_DHCP_LEASE_ACTIVE
FR_DHCP_BULK_LEASE_QUERY
FR_DHCP_LEASE_QUERY_DONE
FR_DHCP_CODE_MAX
FR_DHCP_DO_NOT_RESPOND

Definition at line 43 of file dhcpv4.h.

Function Documentation

◆ fr_dhcpv4_attr_cmp()

fr_cmp_ret_t fr_dhcpv4_attr_cmp	(	void const *	a,
		void const *	b
	)

Definition at line 204 of file base.c.

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◆ fr_dhcpv4_attr_flags()

static fr_dhcpv4_attr_flags_t const * fr_dhcpv4_attr_flags ( fr_dict_attr_t const * da )

inlinestatic

Return DHCPv4-specific flags for a given attribute.

Assert in debug builds when the attribute belongs to another dictionary, as the flags of one protocol say nothing about an attribute of another.

If the attribute does not carry the protocol-specific extension, then assert. Other builds log the error and return zeroed flags instead of NULL.

Definition at line 162 of file dhcpv4.h.

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◆ fr_dhcpv4_decode()

int fr_dhcpv4_decode	(	TALLOC_CTX *	ctx,
		fr_pair_list_t *	out,
		uint8_t const *	data,
		size_t	data_len,
		unsigned int *	code
	)

Definition at line 119 of file packet.c.

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◆ fr_dhcpv4_decode_foreign()

ssize_t fr_dhcpv4_decode_foreign	(	TALLOC_CTX *	ctx,
		fr_pair_list_t *	out,
		uint8_t const *	data,
		size_t	data_len
	)

Definition at line 698 of file decode.c.

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◆ fr_dhcpv4_decode_option()

ssize_t fr_dhcpv4_decode_option	(	TALLOC_CTX *	ctx,
		fr_pair_list_t *	out,
		uint8_t const *	data,
		size_t	data_len,
		void *	decode_ctx
	)

Decode DHCP option.

Parameters

[in]	ctx	context to alloc new attributes in.
[out]	out	Where to write the decoded options.
[in]	data	to parse.
[in]	data_len	of data to parse.
[in]	decode_ctx	Unused.

Definition at line 587 of file decode.c.

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◆ fr_dhcpv4_encode()

ssize_t fr_dhcpv4_encode	(	uint8_t *	buffer,
		size_t	buflen,
		dhcp_packet_t *	original,
		fr_dhcpv4_packet_code_t	code,
		uint32_t	xid,
		fr_pair_list_t *	vps
	)

Definition at line 358 of file base.c.

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◆ fr_dhcpv4_encode_dbuff()

ssize_t fr_dhcpv4_encode_dbuff	(	fr_dbuff_t *	dbuff,
		dhcp_packet_t *	original,
		fr_dhcpv4_packet_code_t	code,
		uint32_t	xid,
		fr_pair_list_t *	vps
	)

Definition at line 363 of file base.c.

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◆ fr_dhcpv4_encode_foreign()

ssize_t fr_dhcpv4_encode_foreign	(	fr_dbuff_t *	dbuff,
		fr_pair_list_t const *	list
	)

Definition at line 786 of file encode.c.

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◆ fr_dhcpv4_encode_option()

ssize_t fr_dhcpv4_encode_option	(	fr_dbuff_t *	dbuff,
		fr_dcursor_t *	cursor,
		void *	encode_ctx
	)

Encode a DHCP option and any sub-options.

Parameters

[out]	dbuff	Where to write encoded DHCP attributes.
[in]	cursor	with current VP set to the option to be encoded. Will be advanced to the next option to encode.
[in]	encode_ctx	Containing DHCPv4 dictionary.

Returns

> 0 length of data written.
< 0 error.
0 not valid option for DHCP (skipping).

Definition at line 737 of file encode.c.

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◆ fr_dhcpv4_flag_dns_label()

static bool fr_dhcpv4_flag_dns_label ( fr_dict_attr_t const * da )

inlinestatic

Definition at line 178 of file dhcpv4.h.

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◆ fr_dhcpv4_flag_exists()

static bool fr_dhcpv4_flag_exists ( fr_dict_attr_t const * da )

inlinestatic

Definition at line 183 of file dhcpv4.h.

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◆ fr_dhcpv4_flag_prefix()

static fr_dhcpv4_attr_flags_prefix_t fr_dhcpv4_flag_prefix ( fr_dict_attr_t const * da )

inlinestatic

Definition at line 188 of file dhcpv4.h.

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◆ fr_dhcpv4_flag_prefix_bits()

static bool fr_dhcpv4_flag_prefix_bits ( fr_dict_attr_t const * da )

inlinestatic

Definition at line 193 of file dhcpv4.h.

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◆ fr_dhcpv4_flag_prefix_split()

static bool fr_dhcpv4_flag_prefix_split ( fr_dict_attr_t const * da )

inlinestatic

Definition at line 198 of file dhcpv4.h.

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◆ fr_dhcpv4_global_free()

void fr_dhcpv4_global_free ( void )

Definition at line 635 of file base.c.

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◆ fr_dhcpv4_global_init()

int fr_dhcpv4_global_init ( void )

Resolve/cache attributes in the DHCP dictionary.

Returns

0 on success.
-1 on failure.

Definition at line 611 of file base.c.

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◆ fr_dhcpv4_is_encodable()

bool fr_dhcpv4_is_encodable	(	void const *	item,
		void const *	uctx
	)

◆ fr_dhcpv4_next_encodable()

void * fr_dhcpv4_next_encodable	(	fr_dcursor_t *	cursor,
		void *	to_eval,
		void *	uctx
	)

DHCPV4-specific iterator.

Definition at line 332 of file base.c.

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◆ fr_dhcpv4_ok()

bool fr_dhcpv4_ok	(	uint8_t const *	data,
		size_t	data_len,
		uint8_t *	message_type,
		uint32_t *	xid
	)

Check received DHCP request is valid and build fr_packet_t structure if it is.

Parameters

	data	pointer to received packet.
	data_len	length of received data, and then length of the actual DHCP data.
[out]	message_type	where the message type will be stored (if used)
[out]	xid	where the xid will be stored (if used)

Returns

true if the packet is well-formed
false if it's a bad packet

Definition at line 248 of file base.c.

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◆ fr_dhcpv4_packet_alloc()

fr_packet_t * fr_dhcpv4_packet_alloc	(	uint8_t const *	data,
		size_t	data_len
	)

Definition at line 418 of file packet.c.

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◆ fr_dhcpv4_packet_encode()

int fr_dhcpv4_packet_encode	(	fr_packet_t *	packet,
		fr_pair_list_t *	list
	)

Definition at line 390 of file packet.c.

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◆ fr_dhcpv4_packet_get_option()

uint8_t const * fr_dhcpv4_packet_get_option	(	dhcp_packet_t const *	packet,
		size_t	packet_size,
		fr_dict_attr_t const *	da
	)

Retrieve a DHCP option from a raw packet buffer.

Definition at line 37 of file packet.c.

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◆ fr_dhcpv4_print_hex()

void fr_dhcpv4_print_hex	(	FILE *	fp,
		uint8_t const *	packet,
		size_t	packet_len
	)

Print a raw DHCP packet as hex.

Definition at line 682 of file base.c.

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◆ fr_dhcpv4_udp_packet_recv()

fr_packet_t * fr_dhcpv4_udp_packet_recv ( int sockfd )

Receive DHCP packet using a connectionless UDP socket.

Parameters

sockfd handle.

Returns

pointer to fr_packet_t if successful.
NULL if failed.

Definition at line 74 of file udp.c.

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◆ fr_dhcpv4_udp_packet_send()

int fr_dhcpv4_udp_packet_send ( fr_packet_t * packet )

Send DHCP packet using a connectionless UDP socket.

Parameters

packet to send

Returns

>= 0 if successful.
< 0 if failed.

Definition at line 41 of file udp.c.

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Variable Documentation

◆ dhcp_header_attrs

fr_dict_attr_t const** dhcp_header_attrs[]

extern

Definition at line 111 of file base.c.

◆ dhcp_header_attrs_len

size_t dhcp_header_attrs_len

extern

Definition at line 127 of file base.c.

◆ dhcp_header_sizes

int dhcp_header_sizes[]

extern

Definition at line 150 of file base.c.

◆ dhcp_message_types

char const* dhcp_message_types[FR_DHCP_CODE_MAX]

extern

Definition at line 129 of file base.c.

◆ eth_bcast

uint8_t eth_bcast[ETH_ADDR_LEN]

extern

Definition at line 167 of file base.c.

◆ libfreeradius_dhcpv4_dict_protocol

fr_dict_protocol_t libfreeradius_dhcpv4_dict_protocol

extern

Definition at line 798 of file base.c.

Data Structures

Macros

Enumerations

Functions

Variables

Detailed Description

Data Structure Documentation

◆ dhcp_packet_t

◆ fr_dhcpv4_attr_flags_t

◆ fr_dhcpv4_ctx_t

Macro Definition Documentation

◆ DEFAULT_PACKET_SIZE

◆ DHCP_CHADDR_LEN

◆ DHCP_FILE_FIELD

◆ DHCP_FILE_LEN

◆ DHCP_OPTION_FIELD

◆ DHCP_OPTION_MAGIC_NUMBER

◆ DHCP_PACK_OPTION1

◆ DHCP_SNAME_FIELD

◆ DHCP_SNAME_LEN

◆ DHCP_UNPACK_OPTION1

◆ DHCP_VEND_LEN

◆ DHCPV4_MAX_ATTRIBUTES

◆ ETH_ADDR_LEN

◆ FR_DHCP_PACKET_CODE_VALID

◆ INADDR_BROADCAST

◆ MAX_PACKET_SIZE

◆ MIN_PACKET_SIZE

Enumeration Type Documentation

◆ fr_dhcpv4_attr_flags_prefix_t

◆ fr_dhcpv4_packet_code_t

Function Documentation

◆ fr_dhcpv4_attr_cmp()

◆ fr_dhcpv4_attr_flags()

◆ fr_dhcpv4_decode()

◆ fr_dhcpv4_decode_foreign()

◆ fr_dhcpv4_decode_option()

◆ fr_dhcpv4_encode()

◆ fr_dhcpv4_encode_dbuff()

◆ fr_dhcpv4_encode_foreign()

◆ fr_dhcpv4_encode_option()

◆ fr_dhcpv4_flag_dns_label()

◆ fr_dhcpv4_flag_exists()

◆ fr_dhcpv4_flag_prefix()

◆ fr_dhcpv4_flag_prefix_bits()

◆ fr_dhcpv4_flag_prefix_split()

◆ fr_dhcpv4_global_free()

◆ fr_dhcpv4_global_init()

◆ fr_dhcpv4_is_encodable()

◆ fr_dhcpv4_next_encodable()

◆ fr_dhcpv4_ok()

◆ fr_dhcpv4_packet_alloc()

◆ fr_dhcpv4_packet_encode()

◆ fr_dhcpv4_packet_get_option()

◆ fr_dhcpv4_print_hex()

◆ fr_dhcpv4_udp_packet_recv()

◆ fr_dhcpv4_udp_packet_send()

Variable Documentation

◆ dhcp_header_attrs

◆ dhcp_header_attrs_len

◆ dhcp_header_sizes

◆ dhcp_message_types

◆ eth_bcast

◆ libfreeradius_dhcpv4_dict_protocol