Module org.jnetpcap

Package org.jnetpcap

Class SockAddr

java.lang.Object

org.jnetpcap.SockAddr

Direct Known Subclasses:

SockAddr.Inet6SockAddr, SockAddr.InetSockAddr, SockAddr.IpxSockAddr, SockAddr.IrdaSockAddr, SockAddr.LinkSockAddr, SockAddr.PacketSockAddr

public class SockAddr
extends Object

A Java representation of the native socket address (sockaddr) structure and its protocol-specific variants. Socket addresses are used to identify network endpoints in various networking protocols.

Platform-Specific Variants

The native sockaddr structure has two main variants:

BSD-style Structure

 struct sockaddr {
     uint8_t  sa_len;     // Total length of the structure
     uint8_t  sa_family;  // Address family (AF_*)
     char     sa_data[14];// Protocol-specific address data
 };
 

POSIX-style Structure

 struct sockaddr {
     uint16_t sa_family;  // Address family (AF_*)
     char     sa_data[14];// Protocol-specific address data
 };
 

Protocol Families

This class serves as the base for protocol-specific socket address structures:

• SockAddr.InetSockAddr - IPv4 addresses (AF_INET)
• SockAddr.Inet6SockAddr - IPv6 addresses (AF_INET6)
• SockAddr.PacketSockAddr - Link-layer packet info (AF_PACKET) [Linux]
• SockAddr.LinkSockAddr - Link-layer info (AF_LINK) [BSD platforms]
• SockAddr.IpxSockAddr - IPX/SPX addresses (AF_IPX)
• SockAddr.IrdaSockAddr - IrDA addresses (AF_IRDA) [Windows]

Memory Management

This class manages native memory through the MemorySegment API. The lifetime of the native memory is controlled by the provided Arena.

Platform Detection

The class automatically detects the platform's socket address format (BSD vs POSIX) and adjusts its behavior accordingly. This detection affects how the family field is read and whether the length field is present.

See Also:

• MemorySegment
• Arena
• SockAddrFamily

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	SockAddr.Inet6SockAddr	Represents an IPv6 socket address (sockaddr_in6 structure).
static final class	SockAddr.InetSockAddr	Represents an IPv4 socket address (sockaddr_in structure).
static final class	SockAddr.IpxSockAddr	The structure of sockaddr_ipx, used for AF_IPX sockets.
static final class	SockAddr.IrdaSockAddr	The structure of sockaddr_irda, used with AF_IRDA sockets on windows (winsock2.h) to access link-layer information.
static final class	SockAddr.LinkSockAddr	The structure of sockaddr_dl, used with AF_LINK sockets on macOS to access link-layer information.
static final class	SockAddr.PacketSockAddr	The structure of sockaddr_ll, used with AF_PACKET sockets for raw packet access on Linux.

Field Summary

Fields

Modifier and Type	Field	Description
protected final MemorySegment	saSegment	The sa segment.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	SockAddr(MemorySegment mseg, SockAddrFamily familyConstant, OptionalInt totalLength)	Instantiates a new sock addr.

Method Summary

Modifier and Type	Method	Description
byte[]	data()	Returns the protocol-specific address data from the sa_data field.
int	family()	Returns the address family identifier as defined in the sa_family field.
Optional<SockAddrFamily>	familyConstant()	Returns the address family as an enumerated constant.
boolean	isFamily(SockAddrFamily family)	Checks if this socket address belongs to the specified address family.
String	toString()	Creates a string representation of the socket address.
OptionalInt	totalLength()	Returns the total length of the socket address structure.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Details

saSegment

protected final MemorySegment saSegment

The sa segment.

Constructor Details

SockAddr

protected SockAddr(MemorySegment mseg,
 SockAddrFamily familyConstant,
 OptionalInt totalLength)

Instantiates a new sock addr.

Parameters:

mseg - the mseg

familyConstant - the family.

totalLength - the addr len.

Method Details

data

public byte[] data()

Returns the protocol-specific address data from the sa_data field. The format and meaning of this data depends on the address family.

Returns:

A byte array containing the raw address data

family

public int family()

Returns the address family identifier as defined in the sa_family field. Common values include AF_INET (IPv4), AF_INET6 (IPv6), AF_PACKET (Linux raw), AF_LINK (BSD raw), etc.

Returns:

The address family value as an integer

familyConstant

public Optional<SockAddrFamily> familyConstant()

Returns the address family as an enumerated constant.

Returns:

An Optional containing the SockAddrFamily constant, or empty if the family value doesn't match any known constant

See Also:

• SockAddrFamily

isFamily

public boolean isFamily(SockAddrFamily family)

Checks if this socket address belongs to the specified address family.

Parameters:

family - The address family to check against

Returns:

true if this address belongs to the specified family

toString

public String toString()

Creates a string representation of the socket address. The format varies depending on the address family and includes relevant address information in a human-readable format.

Overrides:

toString in class Object

Returns:

A string representation of the address

totalLength

public OptionalInt totalLength()

Returns the total length of the socket address structure. This method is primarily relevant for BSD-style socket addresses which include an explicit length field.

Returns:

An OptionalInt containing the structure length on BSD systems, or empty on POSIX systems