ipv4_hdr_t Struct Reference

Data type to represent an IPv4 packet header. More...

Detailed Description

Data type to represent an IPv4 packet header.

The structure of the header is as follows:

 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Version|  IHL  |Type of Service|          Total Length         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|         Identification        |Flags|      Fragment Offset    |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|  Time to Live |    Protocol   |         Header Checksum       |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                       Source Address                          |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                    Destination Address                        |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                    Options                    |    Padding    |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

See also

RFC 791, section 3.1

Definition at line 55 of file hdr.h.

#include <hdr.h>

Data Fields
uint8_t	v_ih
	Version and Internet Header Length. More...
uint8_t	ts
	type of service of packet
network_uint16_t	tl
	total length of the datagram
network_uint16_t	id
	identification value of packet
network_uint16_t	fl_fo
	version control flags and Fragment Offset. More...
uint8_t	ttl
	time to live for this packet
uint8_t	protocol
	protocol of this packet
network_uint16_t	csum
	checksum of this packet
ipv4_addr_t	src
	source address of this packet
ipv4_addr_t	dst
	destination address of this packet

Field Documentation

fl_fo

network_uint16_t ipv4_hdr_t::fl_fo

version control flags and Fragment Offset.

The flags are the 3 most significant bits, and the remaining 13 bits are the fragment offfset

This module provides helper functions to set, get, and check these fields accordingly:

• ipv4_hdr_set_flags()
• ipv4_hdr_get_flags()
• ipv4_hdr_set_fo()
• ipv4_hdr_get_fo()

Definition at line 85 of file hdr.h.

v_ih

uint8_t ipv4_hdr_t::v_ih

Version and Internet Header Length.

The version are the 4 most significant bits and the Internet Header Length the 4 next bit (see above).

This module provides helper functions to set, get, and check these fields accordingly:

• ipv4_hdr_set_version()
• ipv4_hdr_get_version()
• ipv4_hdr_set_ihl()
• ipv4_hdr_get_ihl()

Definition at line 69 of file hdr.h.

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The documentation for this struct was generated from the following file:

• sys/include/net/ipv4/hdr.h