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_ctx_t
	Used as the decoder ctx. More...

Macros
#define	da_is_bits_prefix(_da) (!(_da)->flags.extra && ((_da)->flags.subtype == FLAG_ENCODE_BITS_PREFIX))

#define	da_is_bool_exists(_da) (!(_da)->flags.extra && ((_da)->flags.subtype == FLAG_ENCODE_BOOL_EXISTS))

#define	da_is_dns_label(_da) (!(_da)->flags.extra && ((_da)->flags.subtype == FLAG_ENCODE_DNS_LABEL))

#define	da_is_split_prefix(_da) (!(_da)->flags.extra && ((_da)->flags.subtype == FLAG_ENCODE_SPLIT_PREFIX))

#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 (0x63825363)

#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_OPTION_82 (82)

#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	{ FLAG_ENCODE_NONE = 0 , FLAG_ENCODE_DNS_LABEL , FLAG_ENCODE_SPLIT_PREFIX , FLAG_ENCODE_BITS_PREFIX , FLAG_ENCODE_BOOL_EXISTS }
	subtype values for DHCPv4 and DHCPv6 More...

enum	fr_dhcpv4_packet_code_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
int8_t	fr_dhcpv4_attr_cmp (void const a, void const b)

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. More...

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

ssize_t	fr_dhcpv4_encode_dbuff (fr_dbuff_t dbuff, dhcp_packet_t original, int 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. More...

void	fr_dhcpv4_global_free (void)

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

bool	fr_dhcpv4_is_encodable (void const item, void const uctx)

void *	fr_dhcpv4_next_encodable (fr_dlist_head_t list, void to_eval, void *uctx)
	DHCPV4-specific iterator. More...

bool	fr_dhcpv4_ok (uint8_t const data, ssize_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. More...

fr_packet_t *	fr_dhcpv4_packet_alloc (uint8_t const *data, ssize_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. More...

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

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

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

Variables
fr_dict_attr_t const **	dhcp_header_attrs []

size_t	dhcp_header_attrs_len

int	dhcp_header_sizes []

char const *	dhcp_message_types []

HIDDEN fr_dict_attr_t const *	dhcp_option_82

uint8_t	eth_bcast [ETH_ADDR_LEN]

Detailed Description

Implementation of the DHCPv4 protocol.

Id: 24d4195921871fb197d1b759eb818b23c30c6f5a

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 82 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_ctx_t

struct fr_dhcpv4_ctx_t

Used as the decoder ctx.

Definition at line 152 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

◆ da_is_bits_prefix

#define da_is_bits_prefix ( _da ) (!(_da)->flags.extra && ((_da)->flags.subtype == FLAG_ENCODE_BITS_PREFIX))

Definition at line 79 of file dhcpv4.h.

◆ da_is_bool_exists

#define da_is_bool_exists ( _da ) (!(_da)->flags.extra && ((_da)->flags.subtype == FLAG_ENCODE_BOOL_EXISTS))

Definition at line 80 of file dhcpv4.h.

◆ da_is_dns_label

#define da_is_dns_label ( _da ) (!(_da)->flags.extra && ((_da)->flags.subtype == FLAG_ENCODE_DNS_LABEL))

Definition at line 77 of file dhcpv4.h.

◆ da_is_split_prefix

#define da_is_split_prefix ( _da ) (!(_da)->flags.extra && ((_da)->flags.subtype == FLAG_ENCODE_SPLIT_PREFIX))

Definition at line 78 of file dhcpv4.h.

◆ DEFAULT_PACKET_SIZE

#define DEFAULT_PACKET_SIZE (300)

Definition at line 105 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 110 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 109 of file dhcpv4.h.

◆ DHCP_OPTION_MAGIC_NUMBER

#define DHCP_OPTION_MAGIC_NUMBER (0x63825363)

Definition at line 41 of file dhcpv4.h.

◆ DHCP_PACK_OPTION1

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

Definition at line 114 of file dhcpv4.h.

◆ DHCP_SNAME_FIELD

#define DHCP_SNAME_FIELD (2)

Definition at line 111 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 115 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 107 of file dhcpv4.h.

◆ ETH_ADDR_LEN

#define ETH_ADDR_LEN 6

Definition at line 120 of file dhcpv4.h.

◆ FR_DHCP_OPTION_82

#define FR_DHCP_OPTION_82 (82)

Definition at line 113 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 118 of file dhcpv4.h.

◆ MAX_PACKET_SIZE

#define MAX_PACKET_SIZE (1500 - 40)

Definition at line 106 of file dhcpv4.h.

◆ MIN_PACKET_SIZE

#define MIN_PACKET_SIZE (244)

Definition at line 104 of file dhcpv4.h.

Enumeration Type Documentation

◆ anonymous enum

anonymous enum

subtype values for DHCPv4 and DHCPv6

Enumerator
FLAG_ENCODE_NONE	no particular encoding for DHCPv6 strings
FLAG_ENCODE_DNS_LABEL	encode as DNS label
FLAG_ENCODE_SPLIT_PREFIX	encode IPv4 prefixes as Policy-Filter, split into IP/mask
FLAG_ENCODE_BITS_PREFIX	encode IPv4 prefixes as prefix bits, followed by IP.
FLAG_ENCODE_BOOL_EXISTS	bool as existence checks

Definition at line 69 of file dhcpv4.h.

◆ fr_dhcpv4_packet_code_t

enum fr_dhcpv4_packet_code_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()

int8_t fr_dhcpv4_attr_cmp	(	void const *	a,
		void const *	b
	)

Definition at line 166 of file base.c.

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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 100 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 640 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 538 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,
		int	code,
		uint32_t	xid,
		fr_pair_list_t *	vps
	)

Definition at line 311 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,
		int	code,
		uint32_t	xid,
		fr_pair_list_t *	vps
	)

Definition at line 316 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 759 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 711 of file encode.c.

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◆ fr_dhcpv4_global_free()

void fr_dhcpv4_global_free ( void )

Definition at line 601 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 557 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_dlist_head_t *	list,
		void *	to_eval,
		void *	uctx
	)

DHCPV4-specific iterator.

Definition at line 294 of file base.c.

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◆ fr_dhcpv4_ok()

bool fr_dhcpv4_ok	(	uint8_t const *	data,
		ssize_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 215 of file base.c.

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◆ fr_dhcpv4_packet_alloc()

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

Definition at line 401 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 373 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 645 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 106 of file base.c.

◆ dhcp_header_attrs_len

size_t dhcp_header_attrs_len

extern

Definition at line 122 of file base.c.

◆ dhcp_header_sizes

int dhcp_header_sizes[]

extern

Definition at line 145 of file base.c.

◆ dhcp_message_types

char const* dhcp_message_types[]

extern

Definition at line 124 of file base.c.

◆ dhcp_option_82

HIDDEN fr_dict_attr_t const* dhcp_option_82

extern

Definition at line 164 of file base.c.

◆ eth_bcast

uint8_t eth_bcast[ETH_ADDR_LEN]

extern

Definition at line 162 of file base.c.

Data Structures

Macros

Enumerations

Functions

Variables

Detailed Description

Data Structure Documentation

◆ dhcp_packet_t

◆ fr_dhcpv4_ctx_t

Macro Definition Documentation

◆ da_is_bits_prefix

◆ da_is_bool_exists

◆ da_is_dns_label

◆ da_is_split_prefix

◆ 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_OPTION_82

◆ FR_DHCP_PACKET_CODE_VALID

◆ INADDR_BROADCAST

◆ MAX_PACKET_SIZE

◆ MIN_PACKET_SIZE

Enumeration Type Documentation

◆ anonymous enum

◆ fr_dhcpv4_packet_code_t

Function Documentation

◆ fr_dhcpv4_attr_cmp()

◆ 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_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

◆ dhcp_option_82

◆ eth_bcast