pcpp::DhcpOptionData Struct Reference

#include <DhcpLayer.h>

Public Member Functions
template<typename T >
T	getValueAs (int valueOffset=0)
IPv4Address	getValueAsIpAddr ()
std::string	getValueAsString (int valueOffset=0)
template<typename T >
void	setValue (T newValue, int valueOffset=0)
void	setValueIpAddr (const IPv4Address &addr, int valueOffset=0)
void	setValueString (const std::string &stringValue, int valueOffset=0)
size_t	getTotalSize () const
uint8_t	getLength ()
DhcpOptionTypes	getType ()

Public Attributes
uint8_t	opCode
uint8_t	len
uint8_t	value []

Detailed Description

Representing a DHCP option in a TLV (type-length-value) structure

Member Function Documentation

getLength()

uint8_t pcpp::DhcpOptionData::getLength ( )

inline

Returns

The length of the option value

getTotalSize()

size_t pcpp::DhcpOptionData::getTotalSize ( ) const

inline

Returns

The total size in bytes of this DHCP option which includes: 1[Byte] (option type) + 1[Byte] (option length) + X[Bytes] (option data length). For DHCPOPT_END and DHCPOPT_PAD the value 1 is returned

getType()

DhcpOptionTypes pcpp::DhcpOptionData::getType ( )

inline

Returns

DHCP option type casted as pcpp::DhcpOptionTypes enum

getValueAs()

template<typename T >

T pcpp::DhcpOptionData::getValueAs ( int  valueOffset = 0 )

inline

A templated method to retrieve the DHCP option data as a certain type T. For example, if DHCP option data is 4B (integer) then this method should be used as getValueAs<int>() and it will return the DHCP option data as an integer.
Notice this return value is a copy of the data, not a pointer to the actual data

Parameters

[in]

valueOffset

An optional parameter that specifies where to start copy the DHCP option data. For example: if option data is 20 bytes and you need only the 4 last bytes as integer then use this method like this: getValueAs<int>(16). The default is 0 - start copying from the beginning of option data

Returns

The DHCP option data as type T

getValueAsIpAddr()

IPv4Address pcpp::DhcpOptionData::getValueAsIpAddr ( )

inline

Retrieve DHCP option data as IPv4 address. Relevant only if option value is indeed an IPv4 address

Returns

DHCP option data as IPv4 address

getValueAsString()

std::string pcpp::DhcpOptionData::getValueAsString ( int  valueOffset = 0 )

inline

Retrieve DHCP option data as string. Relevant only if option value is indeed a string

Parameters

[in]

valueOffset

An optional parameter that specifies where to start copy the DHCP option data. For example: when retrieving Client FQDN option, you may ignore the flags and RCODE fields using this method like this: getValueAsString(3). The default is 0 - start copying from the beginning of option data

Returns

DHCP option data as string

setValue()

template<typename T >

void pcpp::DhcpOptionData::setValue ( T  newValue, int  valueOffset = 0  )

inline

A templated method to copy data of type T into the DHCP option data. For example: if option data is 4[Bytes] long use this method with <int> to set an integer value into the DHCP option data: setValue<int>(num)

Parameters

[in]	newValue	The value of type T to copy to DHCP option data
[in]	valueOffset	An optional parameter that specifies where to start setting the option data (default set to 0). For example: if option data is 20 bytes long and you only need to set the 4 last bytes as integer then use this method like this: setValue<int>(num, 16)

setValueIpAddr()

void pcpp::DhcpOptionData::setValueIpAddr ( const IPv4Address &  addr, int  valueOffset = 0  )

inline

Set DHCP option data as IPv4 address. This method copies the 4 bytes of the IP address to the option value

Parameters

[in]	addr	The IPv4 address to set
[in]	valueOffset	An optional parameter that specifies where to start set the option data (default set to 0). For example: if option data is 20 bytes long and you want to set the IP address in the 4 last bytes then use this method like this: setValueIpAddr(your_addr, 16)

setValueString()

void pcpp::DhcpOptionData::setValueString ( const std::string &  stringValue, int  valueOffset = 0  )

inline

Set DHCP option data as string. This method copies the string to the option value. If the string is longer than option length the string is trimmed so it will fit the option length

Parameters

[in]	stringValue	The string to set
[in]	valueOffset	An optional parameter that specifies where to start set the option data (default set to 0). For example: if option data is 20 bytes long and you want to set a 6 char-long string in the 6 last bytes then use this method like this: setValueString("string", 14)

Member Data Documentation

len

uint8_t pcpp::DhcpOptionData::len

DHCP option length

opCode

uint8_t pcpp::DhcpOptionData::opCode

DHCP option code, should be on of DhcpOptionTypes

value

uint8_t pcpp::DhcpOptionData::value[]

DHCP option value