net.h File Reference

Structures and functions for parsing raw network packets. More...

#include <freeradius-devel/build.h>
#include <freeradius-devel/ethernet/ethernet.h>
#include <freeradius-devel/missing.h>
#include <freeradius-devel/util/hash.h>
#include <freeradius-devel/util/misc.h>
#include <freeradius-devel/util/strerror.h>
#include <freeradius-devel/util/table.h>
#include <netinet/in.h>
#include <stdint.h>
#include <sys/socket.h>

Include dependency graph for net.h:

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Data Structures
struct	ip_header6_t
struct	ip_header_t
struct	ip_pseudo_header6_t
struct	udp_header_t

Macros
#define	ETHER_ADDR_LEN   6
#define	ETHER_HDR_LEN   22
#define	I_DF   0x4000
	Dont fragment flag.
#define	IP_HDR_LEN   60
#define	IP_HL(ip)   (((ip)->ip_vhl & 0x0f) << 2)
#define	IP_MF   0x2000
	More fragments flag.
#define	IP_OFFMASK   0x1fff
	Mask for fragmenting bits.
#define	IP_V(ip)   (((ip)->ip_vhl & 0xf0) >> 4)
#define	IP_VHL(v, hl)   ((v & 0x0f) << 4) | (hl & 0x0f)
#define	MAX_RADIUS_LEN   4096
#define	MIN_RADIUS_LEN   20
#define	RADIUS_AUTH_VECTOR_LENGTH   16
#define	RADIUS_HEADER_LENGTH   20

Enumerations
enum	fr_dlt {   DLT_RAW ,   DLT_NULL ,   DLT_LOOP ,   DLT_EN10MB ,   DLT_LINUX_SLL ,   DLT_PFLOG }

Functions
uint16_t	fr_ip6_pesudo_header_checksum (struct in6_addr const *src, struct in6_addr const *dst, uint16_t ip_len, uint8_t ip_next)
uint16_t	fr_ip_header_checksum (uint8_t const *data, uint8_t ihl)
	Calculate IP header checksum.
uint16_t	fr_udp_checksum (uint8_t const *data, uint16_t len, uint16_t checksum, struct in_addr const src_addr, struct in_addr const dst_addr)
	Calculate UDP checksum.
int	fr_udp_header_check (uint8_t const *data, uint16_t remaining, ip_header_t const *ip)
	Check UDP header is valid.

Variables
fr_table_num_sorted_t const	fr_net_af_table []
	Strings for address families.
size_t	fr_net_af_table_len
fr_table_num_sorted_t const	fr_net_ip_proto_table []
	Strings for L4 protocols.
size_t	fr_net_ip_proto_table_len
fr_table_num_sorted_t const	fr_net_sock_type_table []
	Strings for socket types.
size_t	fr_net_sock_type_table_len

Detailed Description

Structures and functions for parsing raw network packets.

Author

Arran Cudbard-Bell (a.cud.nosp@m.bard.nosp@m.b@fre.nosp@m.erad.nosp@m.ius.o.nosp@m.rg)

Copyright

2014 Arran Cudbard-Bell (a.cud.nosp@m.bard.nosp@m.b@fre.nosp@m.erad.nosp@m.ius.o.nosp@m.rg)

Definition in file net.h.

---

Data Structure Documentation

ip_header6_t

struct ip_header6_t

Definition at line 118 of file net.h.

Data Fields
struct in6_addr ip_src	ip_dst	Src and Dst address.
uint8_t	ip_hopl	IP Hop Limit.
uint16_t	ip_len	Payload length.
uint8_t	ip_next	Next header (protocol)
uint32_t	ip_vtcfl	Version, traffic class, flow label.

ip_header_t

struct ip_header_t

Definition at line 104 of file net.h.

Data Fields
struct in_addr ip_src	ip_dst	Src and Dst address.
uint16_t	ip_id	identification.
uint16_t	ip_len	Total length.
uint16_t	ip_off	Fragment offset field.
uint8_t	ip_p	Protocol.
uint16_t	ip_sum	Checksum.
uint8_t	ip_tos	Type of service.
uint8_t	ip_ttl	Time To Live.
uint8_t	ip_vhl	Header length, version.

ip_pseudo_header6_t

struct ip_pseudo_header6_t

Definition at line 128 of file net.h.

Data Fields
struct in6_addr ip_src	ip_dst	Src and Dst address.
uint32_t	ip_len	length
uint32_t	ip_next	upper 24 bits must be zero

udp_header_t

struct udp_header_t

Definition at line 138 of file net.h.

Data Fields
uint16_t	checksum	UDP checksum.
uint16_t	dst	Destination port.
uint16_t	len	UDP length.
uint16_t	src	Source port.

Macro Definition Documentation

ETHER_ADDR_LEN

#define ETHER_ADDR_LEN   6

Definition at line 64 of file net.h.

ETHER_HDR_LEN

#define ETHER_HDR_LEN   22

Definition at line 74 of file net.h.

I_DF

#define I_DF   0x4000

Dont fragment flag.

Definition at line 97 of file net.h.

IP_HDR_LEN

#define IP_HDR_LEN   60

Definition at line 75 of file net.h.

IP_HL

#define IP_HL

(

ip

)

(((ip)->ip_vhl & 0x0f) << 2)

Definition at line 93 of file net.h.

IP_MF

#define IP_MF   0x2000

More fragments flag.

Definition at line 98 of file net.h.

IP_OFFMASK

#define IP_OFFMASK   0x1fff

Mask for fragmenting bits.

Definition at line 99 of file net.h.

IP_V

#define IP_V

(

ip

)

(((ip)->ip_vhl & 0xf0) >> 4)

Definition at line 92 of file net.h.

IP_VHL

#define IP_VHL	(		v,
			hl
	)		((v & 0x0f) << 4) | (hl & 0x0f)

Definition at line 95 of file net.h.

MAX_RADIUS_LEN

#define MAX_RADIUS_LEN   4096

Definition at line 87 of file net.h.

MIN_RADIUS_LEN

#define MIN_RADIUS_LEN   20

Definition at line 88 of file net.h.

RADIUS_AUTH_VECTOR_LENGTH

#define RADIUS_AUTH_VECTOR_LENGTH   16

Definition at line 89 of file net.h.

RADIUS_HEADER_LENGTH

#define RADIUS_HEADER_LENGTH   20

Definition at line 80 of file net.h.

Enumeration Type Documentation

fr_dlt

enum fr_dlt

Enumerator
DLT_RAW
DLT_NULL
DLT_LOOP
DLT_EN10MB
DLT_LINUX_SLL
DLT_PFLOG

Definition at line 51 of file net.h.

Function Documentation

fr_ip6_pesudo_header_checksum()

uint16_t fr_ip6_pesudo_header_checksum	(	struct in6_addr const *	src,
		struct in6_addr const *	dst,
		uint16_t	ip_len,
		uint8_t	ip_next
	)

Definition at line 169 of file net.c.

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fr_ip_header_checksum()

uint16_t fr_ip_header_checksum	(	uint8_t const *	data,
		uint8_t	ihl
	)

Calculate IP header checksum.

Zero out IP header checksum in IP header before calling fr_ip_header_checksum to get 'expected' checksum.

Parameters

data	Pointer to the start of the IP header
ihl	value of ip header length field (number of 32 bit words)

Definition at line 154 of file net.c.

fr_udp_checksum()

uint16_t fr_udp_checksum	(	uint8_t const *	data,
		uint16_t	len,
		uint16_t	checksum,
		struct in_addr const	src_addr,
		struct in_addr const	dst_addr
	)

Calculate UDP checksum.

Zero out UDP checksum in UDP header before calling fr_udp_checksum to get 'expected' checksum.

Parameters

data	Pointer to the start of the UDP header
len	value of udp length field in host byte order. Must be validated to make sure it won't overrun data buffer.
checksum	current checksum, leave as 0 to just enable validation.
src_addr	in network byte order.
dst_addr	in network byte order.

Returns

• 0 if the checksum is correct.
• !0 if checksum is incorrect.

Definition at line 119 of file net.c.

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fr_udp_header_check()

int fr_udp_header_check	(	uint8_t const *	data,
		uint16_t	remaining,
		ip_header_t const *	ip
	)

Check UDP header is valid.

Parameters

data	Pointer to the start of the UDP header
remaining	bits of received packet
ip	pointer to IP header structure

Returns

• 1 if checksum is incorrect.
• 0 if UDP payload length and checksum are correct
• -1 on validation error.

Definition at line 64 of file net.c.

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Variable Documentation

fr_net_af_table

fr_table_num_sorted_t const fr_net_af_table[]

extern

Strings for address families.

Definition at line 48 of file net.c.

fr_net_af_table_len

size_t fr_net_af_table_len

extern

Definition at line 52 of file net.c.

fr_net_ip_proto_table

fr_table_num_sorted_t const fr_net_ip_proto_table[]

extern

Strings for L4 protocols.

Definition at line 28 of file net.c.

fr_net_ip_proto_table_len

size_t fr_net_ip_proto_table_len

extern

Definition at line 34 of file net.c.

fr_net_sock_type_table

fr_table_num_sorted_t const fr_net_sock_type_table[]

extern

Strings for socket types.

Definition at line 39 of file net.c.

fr_net_sock_type_table_len

size_t fr_net_sock_type_table_len

extern

Definition at line 43 of file net.c.