using System;
using System.Runtime.InteropServices;
using Vanara.Extensions;
using Vanara.InteropServices;
using static Vanara.PInvoke.Ws2_32;

#pragma warning disable IDE1006 // Naming Styles
namespace Vanara.PInvoke;

public static partial class Ws2_32
{
	/// <summary/>
	public const int IN6ADDR_LINKLOCALPREFIX_LENGTH = 64;

	/// <summary/>
	public const int IN6ADDR_MULTICASTPREFIX_LENGTH = 8;

	/// <summary/>
	public const int IN6ADDR_SOLICITEDNODEMULTICASTPREFIX_LENGTH = 104;

	/// <summary/>
	public const int IN6ADDR_V4MAPPEDPREFIX_LENGTH = 96;

	/// <summary/>
	public const int IN6ADDR_6TO4PREFIX_LENGTH = 16;

	/// <summary/>
	public const int IN6ADDR_TEREDOPREFIX_LENGTH = 32;

	/// <summary/>
	public const int INET_ADDRSTRLEN  = 22;

	/// <summary/>
	public const int INET6_ADDRSTRLEN = 65;

	/// <summary/>
	public const uint IOC_IN = 0x80000000;

	/// <summary/>
	public const uint IOC_INOUT = IOC_IN | IOC_OUT;

	/// <summary/>
	public const uint IOC_OUT = 0x40000000;

	/// <summary/>
	public const uint IOC_VOID = 0x20000000;

	/// <summary/>
	public const uint IOCPARM_MASK = 0x7f;

	/// <summary>
	/// It is used to return information about each interface on the local machine. Nothing is required on input, but on output, an array of INTERFACE_INFO structures is returned.
	/// </summary>
	public static readonly uint SIO_GET_INTERFACE_LIST = _IOR('t', 127, typeof(uint));

	/// <summary>
	/// This ioctl is the same as SIO_GET_INTERFACE_LIST except the structure returned contains embedded SOCKET_ADDRESS structure to describe each local interface, as opposed to SOCKADDR_GEN structure. This removes the dependency the size of the socket address structure.
	/// </summary>
	public static readonly uint SIO_GET_INTERFACE_LIST_EX = _IOR('t', 126, typeof(uint));

	/// <summary>
	/// This ioctl retrieves the multicast filter set on a given socket. The multicast state is set with the SIO_SET_MULTICAST_FILTER ioctl. This ioctl requires an IGMPv3-enabled network and is supported in only Windows XP.
	/// </summary>
	public static readonly uint SIO_GET_MULTICAST_FILTER = _IOW('t', 124 | IOC_IN, typeof(uint));

	/// <summary>
	/// This ioctl sets the multicast state. The input parameter is a struct ip_msfilter.
	/// </summary>
	public static readonly uint SIO_SET_MULTICAST_FILTER = _IOW('t', 125, typeof(uint));

	/// <summary>
	/// This ioctl retrieves the multicast filter set on a given socket. The multicast state is set with the SIO_SET_MULTICAST_FILTER ioctl. This ioctl requires an IGMPv3-enabled network and is supported in only Windows XP.
	/// </summary>
	public static readonly uint SIOCGIPMSFILTER = SIO_GET_MULTICAST_FILTER;

	/// <summary>
	/// Enables an application to retrieve a list of the IPv4 or IPv6 source addresses that comprise the source filter along with the current mode on a given interface index and a multicast group for a socket. The source filter may either include or exclude the set of source address, depending on the filter mode (MCAST_INCLUDE or MCAST_EXCLUDE), which is defined in the GROUP_FILTER structure.
	/// </summary>
	public static readonly uint SIOCGMSFILTER = _IOW('t', 127 | IOC_IN, typeof(uint));

	/// <summary>
	/// This ioctl sets the multicast state. The input parameter is a struct ip_msfilter.
	/// </summary>
	public static readonly uint SIOCSIPMSFILTER = SIO_SET_MULTICAST_FILTER;

	/// <summary>
	/// Enables an application to specify or modify a list of IPv4 or IPv6 source addresses on a given interface index and to specify or modify a multicast group for a socket. The source filter can include or exclude the set of source address, depending on the filter mode (MCAST_INCLUDE or MCAST_EXCLUDE), which is defined in the GROUP_FILTER structure of the BPXYIOCC macro. The application can join multiple source multicast groups on a single socket; it also can join the same group on multiple interfaces on the same socket. However, there is a maximum limit of 20 groups per single UDP socket and there is a maximum limit of 256 groups per single RAW socket.
	/// </summary>
	public static readonly uint SIOCSMSFILTER = _IOW('t', 126, typeof(uint));

	/// <summary>IPPROTO_IPV6 socket options</summary>
	[PInvokeData("ws2ipdef.h")]
	public enum IPV6
	{
		/// <summary>Adds an interface index to the IFLIST associated with the IP_IFLIST option.</summary>
		[CorrespondingType(typeof(uint))]
		IPV6_ADD_IFLIST = 29,
		/// <summary>
		/// Join the socket to the supplied multicast group on the specified interface. This option is only valid on datagram and raw sockets
		/// (the socket type must be SOCK_DGRAM or SOCK_RAW).
		/// </summary>
		//[CorrespondingType(typeof(ipv6_mreq))]
		IPV6_ADD_MEMBERSHIP = 12,
		/// <summary/>
		IPV6_CHECKSUM = 26,
		/// <summary>
		/// Removes an interface index from the IFLIST associated with the IP_IFLIST option. Entries can be removed only by the application,
		/// so be aware that entries might go stale once an interface is removed.
		/// </summary>
		[CorrespondingType(typeof(uint))]
		IPV6_DEL_IFLIST = 30,
		/// <summary>Don't fragment IP datagrams.</summary>
		IPV6_DONTFRAG = 14,
		/// <summary>
		/// Leave the supplied multicast group from the given interface. This option is only valid on datagram and raw sockets (the socket
		/// type must be SOCK_DGRAM or SOCK_RAW).
		/// </summary>
		//[CorrespondingType(typeof(ipv6_mreq))]
		IPV6_DROP_MEMBERSHIP = 13,
		/// <summary/>
		IPV6_ECN = 50,
		/// <summary>Gets the current IFLIST associated with the IP_IFLIST option. Returns error if IP_IFLIST is not enabled.</summary>
		[CorrespondingType(typeof(uint[]))]
		IPV6_GET_IFLIST = 33,
		/// <summary>
		/// Indicates the application provides the IPv6 header on all outgoing data. If the optval parameter is set to 1 on the call to
		/// setsockopt, the option is enabled. If optval is set to 0, the option is disabled. The default value is disabled. This option is
		/// only valid for datagram and raw sockets (the socket type must be SOCK_DGRAM or SOCK_RAW). A TCP/IP service provider that supports
		/// SOCK_RAW should also support IPV6_HDRINCL.
		/// </summary>
		[CorrespondingType(typeof(BOOL))]
		IPV6_HDRINCL = 2,
		/// <summary>
		/// Indicates that hop (TTL) information should be returned in the LPFN_WSARECVMSG (WSARecvMsg) function. If optval is set to 1 on
		/// the call to setsockopt, the option is enabled. If set to 0, the option is disabled. This option is only valid for datagram and
		/// raw sockets (the socket type must be SOCK_DGRAM or SOCK_RAW).
		/// </summary>
		[CorrespondingType(typeof(BOOL))]
		IPV6_HOPLIMIT = 21,
		/// <summary/>
		IPV6_HOPOPTS = 1,
		/// <summary>
		/// Gets or sets the IP_IFLIST state of the socket. When this option is set to true, Datagram reception is restricted to interfaces
		/// that are in the IFLIST. Datagrams received on any other interfaces are ignored. IFLIST starts empty. Use IP_ADD_IFLIST and
		/// IP_DEL_IFLIST to edit the IFLIST.
		/// </summary>
		[CorrespondingType(typeof(BOOL))]
		IPV6_IFLIST = 28,
		/// <summary>Same as IPV6_ADD_MEMBERSHIP</summary>
		IPV6_JOIN_GROUP = IPV6_ADD_MEMBERSHIP,
		/// <summary>Same as IPV6_DROP_MEMBERSHIP</summary>
		IPV6_LEAVE_GROUP = IPV6_DROP_MEMBERSHIP,
		/// <summary>Gets the system's estimate of the path MTU. Socket must be connected.</summary>
		[CorrespondingType(typeof(uint))]
		IPV6_MTU = 72,
		/// <summary>
		/// Gets or sets the path MTU discovery state for the socket. The default value is IP_PMTUDISC_NOT_SET. For stream sockets,
		/// IP_PMTUDISC_NOT_SET and IP_PMTUDISC_DO will perform path MTU discovery. IP_PMTUDISC_DONT and IP_PMTUDISC_PROBE will turn off path
		/// MTU discovery. For datagram sockets, if set to IP_PMTUDISC_DO , attempts to send packets larger than path MTU will result in an
		/// error. If set to IP_PMTUDISC_DONT, packets will be fragmented according to interface MTU. If set to IP_PMTUDISC_PROBE, attempts
		/// to send packets larger than interface MTU will result in an error.
		/// </summary>
		[CorrespondingType(typeof(uint))]
		IPV6_MTU_DISCOVER = 71,
		/// <summary>
		/// Gets or sets the TTL value associated with IPv6 multicast traffic on the socket. It is illegal to set the TTL to a value greater
		/// than 255. This option is only valid for datagram and raw sockets (the socket type must be SOCK_DGRAM or SOCK_RAW).
		/// </summary>
		[CorrespondingType(typeof(uint))]
		IPV6_MULTICAST_HOPS = 10,
		/// <summary>
		/// Gets or sets the outgoing interface for sending IPv6 multicast traffic. This option does not change the default interface for
		/// receiving IPv6 multicast traffic. This option is important for multihomed computers. The input value for setting this option is a
		/// 4-byte interface index of the desired outgoing interface in host byte order. The GetAdaptersAddresses function can be used to
		/// obtain the interface index information. If optval is set to NULL on call to setsockopt, the default IPv6 interface is used. If
		/// optval is zero , the default interface for receiving multicast is specified for sending multicast traffic. When getting this
		/// option, the optval returns the current default interface index for sending multicast IPv6 traffic in host byte order.
		/// </summary>
		[CorrespondingType(typeof(uint))]
		IPV6_MULTICAST_IF = 9,
		/// <summary>
		/// Indicates multicast data sent on the socket will be echoed to the sockets receive buffer if it is also joined on the destination
		/// multicast group. If optval is set to 1 on the call to setsockopt, the option is enabled. If set to 0, the option is disabled.
		/// This option is only valid for datagram and raw sockets (the socket type must be SOCK_DGRAM or SOCK_RAW).
		/// </summary>
		[CorrespondingType(typeof(BOOL))]
		IPV6_MULTICAST_LOOP = 11,
		/// <summary/>
		IPV6_NRT_INTERFACE = 74,
		/// <summary>Indicates that packet information should be returned by the LPFN_WSARECVMSG (WSARecvMsg) function.</summary>
		[CorrespondingType(typeof(BOOL))]
		IPV6_PKTINFO = 19,
		/// <summary/>
		IPV6_PKTINFO_EX = 51,
		/// <summary>
		/// Enables restriction of a socket to a specified scope, such as addresses with the same link local or site local prefix. Provides
		/// various restriction levels and default settings. See IPV6_PROTECTION_LEVEL for more information.
		/// </summary>
		[CorrespondingType(typeof(int))]
		IPV6_PROTECTION_LEVEL = 23,
		/// <summary/>
		IPV6_RECVDSTADDR = 25,
		/// <summary/>
		IPV6_RECVECN = 50,
		/// <summary/>
		IPV6_RECVERR = 75,
		/// <summary>
		/// Indicates whether the IP stack should populate the control buffer with details about which interface received a packet with a
		/// datagram socket. When this value is true, the LPFN_WSARECVMSG (WSARecvMsg) function will return optional control data containing
		/// the interface where the packet was received for datagram sockets. This option allows the IPv6 interface where the packet was
		/// received to be returned in the WSAMSG structure. This option is only valid for datagram and raw sockets (the socket type must be
		/// SOCK_DGRAM or SOCK_RAW).
		/// </summary>
		[CorrespondingType(typeof(BOOL))]
		IPV6_RECVIF = 24,
		/// <summary/>
		IPV6_RECVRTHDR = 38,
		/// <summary>
		/// Indicates whether the IP stack should populate the control buffer with a message containing the Traffic Class IPv6 header field
		/// on a received datagram. When this value is true, the LPFN_WSARECVMSG (WSARecvMsg) function will return optional control data
		/// containing the Traffic Class IPv6 header field value of the received datagram. This option allows the Traffic Class IPv6 header
		/// field of the received datagram to be returned in the WSAMSG structure. The returned message type will be IPV6_TCLASS. All DSCP
		/// and ECN bits of the Traffic Class field will be returned. This option is only valid on datagram sockets (the socket type must be SOCK_DGRAM).
		/// </summary>
		[CorrespondingType(typeof(BOOL))]
		IPV6_RECVTCLASS = 40,
		/// <summary/>
		IPV6_RTHDR = 32,
		/// <summary/>
		IPV6_TCLASS = 39,
		/// <summary>
		/// Gets or sets the current TTL value associated with IPv6 socket for unicast traffic. It is illegal to set the TTL to a value
		/// greater than 255.
		/// </summary>
		[CorrespondingType(typeof(uint))]
		IPV6_UNICAST_HOPS = 4,
		/// <summary>
		/// Gets or sets the outgoing interface for sending IPv6 traffic. This option does not change the default interface for receiving
		/// IPv6 traffic. This option is important for multihomed computers. The input value for setting this option is a 4-byte interface
		/// index of the desired outgoing interface in host byte order. The GetAdaptersAddresses function can be used to obtain the interface
		/// index information. If optval is zero, the default interface for sending IPv6 traffic is set to unspecified. When getting this
		/// option, the optval returns the current default interface index for sending IPv6 traffic in host byte order.
		/// </summary>
		[CorrespondingType(typeof(uint))]
		IPV6_UNICAST_IF = 31,
		/// <summary>
		/// Gets or sets an upper bound on the IP layer MTU (in bytes) for the given socket. If the value is higher than the system's
		/// estimate of the path MTU (which you can retrieve on a connected socket by querying the IPV6_MTU socket option), then the option
		/// has no effect. If the value is lower, then outbound packets larger than this will be fragmented, or will fail to send, depending
		/// on the value of IPV6_DONTFRAG. Default value is IP_UNSPECIFIED_USER_MTU (MAXULONG). For type-safety, you should use the
		/// WSAGetIPUserMtu and WSASetIPUserMtu functions instead of using the socket option directly.
		/// </summary>
		[CorrespondingType(typeof(uint))]
		IPV6_USER_MTU = 76,
		/// <summary>
		/// Indicates if a socket created for the AF_INET6 address family is restricted to IPv6 communications only. Sockets created for the
		/// AF_INET6 address family may be used for both IPv6 and IPv4 communications. Some applications may want to restrict their use of a
		/// socket created for the AF_INET6 address family to IPv6 communications only. When this value is nonzero (the default on Windows),
		/// a socket created for the AF_INET6 address family can be used to send and receive IPv6 packets only. When this value is zero, a
		/// socket created for the AF_INET6 address family can be used to send and receive packets to and from an IPv6 address or an IPv4
		/// address. Note that the ability to interact with an IPv4 address requires the use of IPv4 mapped addresses. This socket option is
		/// supported on Windows Vista or later.
		/// </summary>
		[CorrespondingType(typeof(BOOL))]
		IPV6_V6ONLY = 27,
		/// <summary/>
		IPV6_WFP_REDIRECT_CONTEXT = 70,
		/// <summary/>
		IPV6_WFP_REDIRECT_RECORDS = 60,
	}

	/// <summary>The <c>MULTICAST_MODE_TYPE</c> enumeration specifies the filter mode for multicast group addresses.</summary>
	/// <remarks>
	/// <para>This enumeration is supported on Windows Vistaand later.</para>
	/// <para>
	/// The <c>MULTICAST_MODE_TYPE</c> enumeration is used in the <c>gf_fmode</c> member of the GROUP_SOURCE_REQ structure to determine if a
	/// list of IP addresses should included or excluded. The values from this enumeration can also be used in the <c>imsf_fmode</c> member
	/// of the ip_msfilter structure.
	/// </para>
	/// <para>
	/// The <c>MULTICAST_MODE_TYPE</c> enumeration is defined in the Ws2ipdef.h header file which is automatically included in the Ws2tcpip.h
	/// header file. The Ws2ipdef.h header files should never be used directly.
	/// </para>
	/// </remarks>
	// https://docs.microsoft.com/en-us/windows/win32/api/ws2ipdef/ne-ws2ipdef-multicast_mode_type typedef enum { MCAST_INCLUDE,
	// MCAST_EXCLUDE } MULTICAST_MODE_TYPE;
	[PInvokeData("ws2ipdef.h", MSDNShortId = "7ca9cb9b-618a-4e73-9e2a-18e55e5c00c0")]
	public enum MULTICAST_MODE_TYPE
	{
		/// <summary>The filter contains a list of IP addresses to include.</summary>
		MCAST_INCLUDE,

		/// <summary>The filter contains a list of IP addresses to exclude.</summary>
		MCAST_EXCLUDE,
	}

	/// <summary>
	/// Used for an ioctl that reads data from the device driver. The driver will be allowed to return sizeof(data_type) bytes to the user.
	/// </summary>
	/// <param name="x">The type.</param>
	/// <param name="y">The value.</param>
	/// <param name="t">The type from which a size is extracted.</param>
	/// <returns>IOCtrl value.</returns>
	public static uint _IOR(char x, uint y, Type t) => IOC_OUT | (((uint)Marshal.SizeOf(t) & IOCPARM_MASK) << 16) | ((uint)x) << 8 | (y);

	/// <summary>Used for an ioctl that writes data to the device driver.</summary>
	/// <param name="x">The type.</param>
	/// <param name="y">The value.</param>
	/// <param name="t">The type from which a size is extracted.</param>
	/// <returns>IOCtrl value.</returns>
	public static uint _IOW(char x, uint y, Type t) => IOC_IN | (((uint)Marshal.SizeOf(t) & IOCPARM_MASK) << 16) | ((uint)x) << 8 | (y);

	/// <summary>Gets the size, in bytes, of an GROUP_FILTER with a number of SOCKADDR_STORAGE items.</summary>
	/// <param name="numsrc">The number of SOCKADDR_STORAGE sources.</param>
	/// <returns>Size, in bytes.</returns>
	[PInvokeData("ws2ipdef.h")]
	public static int GROUP_FILTER_SIZE(int numsrc) => Marshal.SizeOf(typeof(GROUP_FILTER)) - Marshal.SizeOf(typeof(SOCKADDR_STORAGE)) + numsrc * Marshal.SizeOf(typeof(SOCKADDR_STORAGE));

	/// <summary>Gets the size, in bytes, of an IP_MSFILTER with a number of IN_ADDR items.</summary>
	/// <param name="NumSources">The number of IN_ADDR sources.</param>
	/// <returns>Size, in bytes.</returns>
	[PInvokeData("ws2ipdef.h")]
	public static int IP_MSFILTER_SIZE(int NumSources) => Marshal.SizeOf(typeof(IP_MSFILTER)) - Marshal.SizeOf(typeof(IN_ADDR)) + NumSources * Marshal.SizeOf(typeof(IN_ADDR));

	/// <summary>The <c>GROUP_FILTER</c> structure provides multicast filtering parameters for multicast IPv6 or IPv4 addresses.</summary>
	/// <remarks>
	/// <para>
	/// The <c>GROUP_FILTER</c> structure is used with either IPv6 or IPv4 multicast addresses. The <c>GROUP_FILTER</c> structure is
	/// passed as an argument for the <c>SIOCGMSFILTER</c> and <c>SIOCSMSFILTER</c> IOCTLs.
	/// </para>
	/// <para>
	/// The <c>GROUP_FILTER</c> structure and related structures used for multicast programming are based on IETF recommendations in
	/// sections 5 and 8.2 of RFC 3768. For more information, see http://www.ietf.org/rfc/rfc3678.txt.
	/// </para>
	/// <para>
	/// On Windows Vista and later, a set of socket options are available for multicast programming that support IPv6 and IPv4
	/// addresses. These socket options are IP agnostic and can be used on both IPv6 and IPv4. These IP agnostic options use the
	/// GROUP_REQ and the GROUP_SOURCE_REQ structures and are the preferred socket options for multicast programming on Windows Vista
	/// and later.
	/// </para>
	/// <para>The GetAdaptersAddresses function can be used to obtain interface index information required for the gf_interface member.</para>
	/// <para>
	/// The <c>GROUP_FILTER</c> structure and the Ioctls that use this structure are only valid on datagram and raw sockets (the socket
	/// type must be <c>SOCK_DGRAM</c> or <c>SOCK_RAW</c>).
	/// </para>
	/// <para>
	/// The <c>GROUP_FILTER</c> structure is defined in the Ws2ipdef.h header file which is automatically included in the Ws2tcpip.h
	/// header file. The Ws2ipdef.h header files should never be used directly.
	/// </para>
	/// </remarks>
	// https://docs.microsoft.com/en-us/windows/win32/api/ws2ipdef/ns-ws2ipdef-group_filter typedef struct group_filter { ULONG
	// gf_interface; SOCKADDR_STORAGE gf_group; MULTICAST_MODE_TYPE gf_fmode; ULONG gf_numsrc; SOCKADDR_STORAGE gf_slist[1]; }
	// GROUP_FILTER, *PGROUP_FILTER;
	[PInvokeData("ws2ipdef.h", MSDNShortId = "09aa1f67-c858-4bef-9a98-ce25ebcc1d4e")]
	[VanaraMarshaler(typeof(SafeAnysizeStructMarshaler<IP_MSFILTER>), "gf_numsrc")]
	[StructLayout(LayoutKind.Sequential)]
	public struct GROUP_FILTER
	{
		/// <summary>The interface index of the local interface for the multicast group to filter.</summary>
		public uint gf_interface;

		/// <summary>The multicast address group that should be filtered. This may be either an IPv6 or IPv4 multicast address.</summary>
		public SOCKADDR_STORAGE gf_group;

		/// <summary>
		/// <para>The multicast filter mode.</para>
		/// <para>
		/// This member can be one of the values from the MULTICAST_MODE_TYPE enumeration type defined in the Ws2ipdef.h header file.
		/// This member determines if the list of IP addresses in the <c>gf_numsrc</c> member should be included or excluded.
		/// </para>
		/// <list type="table">
		/// <listheader>
		/// <term>Value</term>
		/// <term>Meaning</term>
		/// </listheader>
		/// <item>
		/// <term>MCAST_INCLUDE</term>
		/// <term>The filter contains a list of IP addresses to include.</term>
		/// </item>
		/// <item>
		/// <term>MCAST_EXCLUDE</term>
		/// <term>The filter contains a list of IP addresses to exclude.</term>
		/// </item>
		/// </list>
		/// </summary>
		public MULTICAST_MODE_TYPE gf_fmode;

		/// <summary>The number of multicast filter source address entries in the <c>gf_slist</c> member.</summary>
		public uint gf_numsrc;

		/// <summary>
		/// An array of SOCKADDR_STORAGE structures specifying the multicast source addresses to include or exclude. These IP addresses
		/// may be either IPv6 or IPv4 addresses, but they must be the same address family (IPv6 or IPv4) as the address specified in
		/// the <c>gf_group</c> member..
		/// </summary>
		[MarshalAs(UnmanagedType.ByValArray, SizeConst = 1)]
		public SOCKADDR_STORAGE[] gf_slist;
	}

	/// <summary>
	/// The <c>in_pktinfo</c> structure is used to store received packet address information, and is used by Windows to return
	/// information about received packets and also allows specifying the local IPv4 address to use for sending packets.
	/// </summary>
	/// <remarks>
	/// <para>
	/// If the IP_PKTINFO socket option is set on a socket of type <c>SOCK_DGRAM</c> or <c>SOCK_RAW</c>, one of the control data objects
	/// returned by the LPFN_WSARECVMSG (WSARecvMsg) function will contain an <c>in_pktinfo</c> structure used to store received packet
	/// address information.
	/// </para>
	/// <para>
	/// On an IPv4 socket of type <c>SOCK_DGRAM</c> or <c>SOCK_RAW</c>, an application can specific the local IP address to use for
	/// sending with the WSASendMsg function. One of the control data objects passed in the WSAMSG structure to the <c>WSASendMsg</c>
	/// function may contain an <c>in_pktinfo</c> structure used to specify the local IPv4 address to use for sending.
	/// </para>
	/// <para>
	/// On the Microsoft Windows Software Development Kit (SDK) released for Windows Vista and later, the organization of header files
	/// has changed and the <c>in_pktinfo</c> structure is defined in the <c>Ws2ipdef.h</c> header file which is automatically included
	/// in the <c>Ws2tcpip.h</c> header file. The <c>Ws2ipdef.h</c> header files should never be used directly.
	/// </para>
	/// </remarks>
	// https://docs.microsoft.com/en-us/windows/win32/api/ws2ipdef/ns-ws2ipdef-in_pktinfo typedef struct in_pktinfo { IN_ADDR ipi_addr;
	// ULONG ipi_ifindex; } IN_PKTINFO, *PIN_PKTINFO;
	[PInvokeData("ws2ipdef.h", MSDNShortId = "NS:ws2ipdef.in_pktinfo")]
	[StructLayout(LayoutKind.Sequential)]
	public struct IN_PKTINFO
	{
		/// <summary>
		/// The destination IPv4 address from the IP header of the received packet when used with the LPFN_WSARECVMSG (WSARecvMsg)
		/// function. The local source IPv4 address to set in the IP header when used with the WSASendMsg function.
		/// </summary>
		public IN_ADDR ipi_addr;

		/// <summary>
		/// The interface on which the packet was received when used with the LPFN_WSARECVMSG (WSARecvMsg) function. The interface on
		/// which the packet should be sent when used with the WSASendMsg function.
		/// </summary>
		public uint ipi_ifindex;
	}

	/// <summary>
	/// The <c>in6_pktinfo</c> structure is used to store received IPv6 packet address information, and is used by Windows to return
	/// information about received packets and also allows specifying the local IPv6 address to use for sending packets.
	/// </summary>
	/// <remarks>
	/// <para>
	/// If the IPV6_PKTINFO socket option is set on a socket of type <c>SOCK_DGRAM</c> or <c>SOCK_RAW</c>, one of the control data
	/// objects returned by the LPFN_WSARECVMSG (WSARecvMsg) function will contain an <c>in6_pktinfo</c> structure used to store received
	/// packet address information.
	/// </para>
	/// <para>
	/// On an IPv6 socket of type <c>SOCK_DGRAM</c> or <c>SOCK_RAW</c>, an application can specific the local IP source address to use
	/// for sending with the WSASendMsg function. One of the control data objects passed in the WSAMSG structure to the <c>WSASendMsg</c>
	/// function may contain an <c>in6_pktinfo</c> structure used to specify the local IPv6 address to use for sending.
	/// </para>
	/// <para>
	/// On the Microsoft Windows Software Development Kit (SDK) released for Windows Vista and later, the organization of header files
	/// has changed and the <c>in6_pktinfo</c> structure is defined in the <c>Ws2ipdef.h</c> header file which is automatically included
	/// in the <c>Ws2tcpip.h</c> header file. The <c>Ws2ipdef.h</c> header files should never be used directly.
	/// </para>
	/// </remarks>
	// https://docs.microsoft.com/en-us/windows/win32/api/ws2ipdef/ns-ws2ipdef-in6_pktinfo typedef struct in6_pktinfo { IN6_ADDR
	// ipi6_addr; ULONG ipi6_ifindex; } IN6_PKTINFO, *PIN6_PKTINFO;
	[PInvokeData("ws2ipdef.h", MSDNShortId = "NS:ws2ipdef.in6_pktinfo")]
	[StructLayout(LayoutKind.Sequential)]
	public struct IN6_PKTINFO
	{
		/// <summary>
		/// The destination IPv6 address from the IP header of the received packet when used with the LPFN_WSARECVMSG (WSARecvMsg)
		/// function. The local source IPv6 address to set in the IP header when used with the WSASendMsg function.
		/// </summary>
		public IN6_ADDR ipi6_addr;

		/// <summary>
		/// The interface on which the packet was received when used with the LPFN_WSARECVMSG (WSARecvMsg) function. The interface on
		/// which the packet should be sent when used with the WSASendMsg function.
		/// </summary>
		public uint ipi6_ifindex;
	}

	/// <summary>The <c>ip_mreq</c> structure provides multicast group information for IPv4 addresses.</summary>
	/// <remarks>
	/// <para>
	/// The <c>ip_mreq</c> structure is used with IPv4 addresses. The <c>ip_mreq</c> structure is used with the IP_ADD_MEMBERSHIP and
	/// <c>IP_DROP_MEMBERSHIP</c> socket options.
	/// </para>
	/// <para>
	/// The <c>ip_mreq</c> structure and related structures used for IPv4 multicast programming are based on IETF recommendations in
	/// sections 4 and 8.1 of RFC 3768. For more information, see http://www.ietf.org/rfc/rfc3678.txt.
	/// </para>
	/// <para>
	/// For more configurable multicast capabilities with IPv4, use the ip_mreq_source structure. See Multicast Programming for more information.
	/// </para>
	/// <para>
	/// On Windows Vista and later, a set of socket options are available for multicast programming that support IPv6 and IPv4 addresses.
	/// These socket options are IP agnostic and can be used on both IPv6 and IPv4. These IP agnostic options use the GROUP_REQ and the
	/// GROUP_SOURCE_REQ structures and are the preferred socket options for multicast programming on Windows Vista and later.
	/// </para>
	/// <para>The <c>ip_mreq</c> structure is the IPv4 equivalent of the IPv6-based ipv6_mreq structure.</para>
	/// <para>
	/// The <c>imr_interface</c> member can be an interface index. Any IP address in the 0.x.x.x block (first octet of 0) except for the
	/// IP address of 0.0.0.0 is treated as an interface index. An interface index is a 24-bit number. The 0.0.0.0/8 IPv4 address block
	/// is not used (this range is reserved). The GetAdaptersAddresses function can be used to obtain interface index information to use
	/// for the <c>imr_interface</c> member.
	/// </para>
	/// <para>
	/// It is recommended that a local IPv4 address or interface index always be specified in the <c>imr_interface</c> member of the
	/// <c>ip_mreq</c> structure, rather than use the default interface. This is particularly important on computers with multiple
	/// network interfaces and multiple public IPv4 addresses.
	/// </para>
	/// <para>
	/// The default interface used for IPv4 multicast is determined by the networking stack in Windows. An application can determine the
	/// default interface used for IPv4 multicast using the GetIpForwardTable function to retrieve the IPv4 routing table. The network
	/// interface with the lowest value for the routing metric for a destination IP address of 224.0.0.0 is the default interface for
	/// IPv4 multicast. The routing table can also be displayed from the command prompt with the following command:
	/// </para>
	/// <para><c>route print</c></para>
	/// <para>
	/// The IP_MULTICAST_IF socket option can be used to set the default interface to send IPv4 multicast packets. This socket option
	/// does not change the default interface used to receive IPv4 multicast packets.
	/// </para>
	/// <para>
	/// A typical IPv4 multicast application would use the IP_ADD_MEMBERSHIP socket option with the <c>ip_mreq</c> structure to join a
	/// multicast group and listen for multicast packets on a specific interface. The <c>IP_MULTICAST_IF</c> socket option would be used
	/// to set the interface to send IPv4 multicast packets to the multicast group. The most common scenario would be a multicast
	/// application that listens and sends on the same interface for a multicast group. Multiple sockets might be used by a multicast
	/// application with one socket for listening and one or more sockets for sending.
	/// </para>
	/// <para>
	/// On the Microsoft Windows Software Development Kit (SDK) released for Windows Vista and later, the organization of header files
	/// has changed and the <c>ip_mreq</c> structure is defined in the <c>Ws2ipdef.h</c> header file which is automatically included in
	/// the <c>Ws2tcpip.h</c> header file. The <c>Ws2ipdef.h</c> header files should never be used directly.
	/// </para>
	/// <para>
	/// <c>Note</c> The <c>IP_MREQ</c> and <c>PIP_MREQ</c> derived structures are only defined on the Windows SDK released with Windows
	/// Vista and later. The <c>ip_mreq</c> structure should be used on earlier versions of the Windows SDK.
	/// </para>
	/// </remarks>
	// https://docs.microsoft.com/en-us/windows/win32/api/ws2ipdef/ns-ws2ipdef-ip_mreq typedef struct ip_mreq { IN_ADDR imr_multiaddr;
	// IN_ADDR imr_interface; } IP_MREQ, *PIP_MREQ;
	[PInvokeData("ws2ipdef.h", MSDNShortId = "NS:ws2ipdef.ip_mreq")]
	[StructLayout(LayoutKind.Sequential)]
	public struct IP_MREQ
	{
		/// <summary>The address of the IPv4 multicast group.</summary>
		public IN_ADDR imr_multiaddr;

		/// <summary>
		/// <para>
		/// The local IPv4 address of the interface or the interface index on which the multicast group should be joined or dropped. This
		/// value is in network byte order. If this member specifies an IPv4 address of 0.0.0.0, the default IPv4 multicast interface is used.
		/// </para>
		/// <para>To use an interface index of 1 would be the same as an IP address of 0.0.0.1.</para>
		/// </summary>
		public IN_ADDR imr_interface;
	}

	/// <summary>The <c>ip_msfilter</c> structure provides multicast filtering parameters for IPv4 addresses.</summary>
	/// <remarks>
	/// <para>
	/// The <c>ip_msfilter</c> structure is used with IPv4 addresses. The <c>ip_msfilter</c> structure is passed as an argument for the
	/// <c>SIO_GET_MULTICAST_FILTER</c> and <c>SIO_SET_MULTICAST_FILTER</c> IOCTLs.
	/// </para>
	/// <para>
	/// The <c>ip_msfilter</c> structure and related structures used for IPv4 multicast programming are based on IETF recommendations in
	/// sections 4 and 8.1 of RFC 3768. For more information, see http://www.ietf.org/rfc/rfc3678.txt.
	/// </para>
	/// <para>
	/// On Windows Vista and later, a set of socket options are available for multicast programming that support IPv6 and IPv4
	/// addresses. These socket options are IP agnostic and can be used on both IPv6 and IPv4. These IP agnostic options use the
	/// GROUP_REQ and the GROUP_SOURCE_REQ structures and the <c>SIOCSMSFILTER</c> and <c>SIOCGMSFILTER</c> IOCTLs. These are the
	/// preferred socket options and IOCTLs for multicast programming on Windows Vista and later.
	/// </para>
	/// <para>
	/// The <c>imsf_interface</c> member can be an interface index. Any IPv4 address in the 0.x.x.x block (first octet of 0) except for
	/// the IPv4 address of 0.0.0.0 is treated as an interface index. An interface index is a 24-bit number. The 0.0.0.0/8 IPv4 address
	/// block is not used (this range is reserved). The GetAdaptersAddresses function can be used to obtain interface index information
	/// to use for the <c>imsf_interface</c> member.
	/// </para>
	/// <para>
	/// It is recommended that a local IPv4 address or interface index always be specified in the <c>imsf_interface</c> member of the
	/// <c>ip_msfilter</c> structure, rather than use the default interface. This is particularly important on computers with multiple
	/// network interfaces and multiple public IPv4 addresses.
	/// </para>
	/// <para>
	/// The default interface used for IPv4 multicast is determined by the networking stack in Windows. An application can determine the
	/// default interface used for IPv4 multicast using the GetIpForwardTable function to retrieve the IPv4 routing table. The network
	/// interface with the lowest value for the routing metric for a destination IP address of 224.0.0.0 is the default interface for
	/// IPv4 multicast. The routing table can also be displayed from the command prompt with the following command:
	/// </para>
	/// <para><c>route print</c></para>
	/// <para>
	/// The IP_MULTICAST_IF socket option can be used to set the default interface to send IPv4 multicast packets. This socket option
	/// does not change the default interface used to receive IPv4 multicast packets.
	/// </para>
	/// <para>
	/// A typical IPv4 multicast application would use the IP_ADD_MEMBERSHIP socket option with the ip_mreq structure or the
	/// <c>IP_ADD_SOURCE_MEMBERSHIP</c> socket option with the ip_mreq_source structure to join a multicast group and listen for
	/// multicast packets on a specific interface. The <c>IP_MULTICAST_IF</c> socket option would be used to set the interface to send
	/// IPv4 multicast packets to the multicast group. The most common scenario would be a multicast application that listens and sends
	/// on the same interface for a multicast group. Multiple sockets might be used by a multicast application with one socket for
	/// listening and one or more sockets for sending.
	/// </para>
	/// <para>
	/// On the Microsoft Windows Software Development Kit (SDK) released for Windows Vista and later, the organization of header files
	/// has changed and the <c>ip_msfilter</c> structure is defined in the Ws2ipdef.h header file which is automatically included in the
	/// Ws2tcpip.h header file. The Ws2ipdef.h header files should never be used directly.
	/// </para>
	/// <para>
	/// <c>Note</c> The <c>IP_MSFILTER</c> and <c>PIP_MSFILTER</c> derived structures are only defined on the Windows SDK released with
	/// Windows Vista and later. The <c>ip_msfilter</c> structure should be used on earlier versions of the Windows SDK.
	/// </para>
	/// </remarks>
	// https://docs.microsoft.com/en-us/windows/win32/api/ws2ipdef/ns-ws2ipdef-ip_msfilter typedef struct ip_msfilter { IN_ADDR
	// imsf_multiaddr; IN_ADDR imsf_interface; MULTICAST_MODE_TYPE imsf_fmode; ULONG imsf_numsrc; IN_ADDR imsf_slist[1]; } IP_MSFILTER, *PIP_MSFILTER;
	[PInvokeData("ws2ipdef.h", MSDNShortId = "8d9d515e-9369-4d71-9614-6cbeb5557a5d")]
	[VanaraMarshaler(typeof(SafeAnysizeStructMarshaler<IP_MSFILTER>), "imsf_numsrc")]
	[StructLayout(LayoutKind.Sequential)]
	public struct IP_MSFILTER
	{
		/// <summary>The IPv4 address of the multicast group.</summary>
		public IN_ADDR imsf_multiaddr;

		/// <summary>
		/// <para>
		/// The local IPv4 address of the interface or the interface index on which the multicast group should be filtered. This value
		/// is in network byte order. If this member specifies an IPv4 address of 0.0.0.0, the default IPv4 multicast interface is used.
		/// </para>
		/// <para>To use an interface index of 1 would be the same as an IP address of 0.0.0.1.</para>
		/// </summary>
		public IN_ADDR imsf_interface;

		/// <summary>
		/// <para>
		/// The multicast filter mode to be used. This parameter can be either MCAST_INCLUDE (value of 0) to include particular
		/// multicast sources, or MCAST_EXCLUDE (value of 1) to exclude traffic from specified sources.
		/// </para>
		/// <para>On Windows Server 2003 and Windows XP, these values are defined in the Ws2tcpip.h header file.</para>
		/// <para>
		/// On Windows Vistaand later, these values are defined as enumeration values in the MULTICAST_MODE_TYPE enumeration defined in
		/// the Ws2ipdef.h header file.
		/// </para>
		/// </summary>
		public MULTICAST_MODE_TYPE imsf_fmode;

		/// <summary>The number of sources in the <c>imsf_slist</c> member.</summary>
		public uint imsf_numsrc;

		/// <summary>An array of in_addr structures that specify the IPv4 multicast source addresses to include or exclude.</summary>
		[MarshalAs(UnmanagedType.ByValArray, SizeConst = 1)]
		public IN_ADDR[] imsf_slist;
	}

	/// <summary>The <c>ipv6_mreq</c> structure provides multicast group information for IPv6 addresses.</summary>
	/// <remarks>
	/// <para>
	/// The <c>ipv6_mreq</c> structure is used with IPv6 addresses. The <c>ipv6_mreq</c> structure is used with the IPV6_ADD_MEMBERSHIP,
	/// <c>IPV6_DROP_MEMBERSHIP</c>, <c>IPV6_JOIN_GROUP</c>, and <c>IPV6_LEAVE_GROUP</c> socket options. The <c>IPV6_JOIN_GROUP</c> and
	/// <c>IPV6_ADD_MEMBERSHIP</c> socket options are defined to be the same. The <c>IPV6_LEAVE_GROUP</c> and <c>IPV6_DROP_MEMBERSHIP</c>
	/// socket options are defined to be the same.
	/// </para>
	/// <para>
	/// On Windows Vista and later, a set of socket options are available for multicast programming that support IPv6 and IPv4 addresses.
	/// These socket options are IP agnostic and can be used on both IPv6 and IPv4. These IP agnostic options use the GROUP_REQ and the
	/// GROUP_SOURCE_REQ structures and are the preferred socket options for multicast programming on Windows Vista and later.
	/// </para>
	/// <para>The <c>ipv6_mreq</c> structure is the IPv6 equivalent of the IPv4-based ip_mreq structure.</para>
	/// <para>
	/// The GetAdaptersAddresses function can be used to obtain interface index information required for the <c>ipv6mr_interface</c> member.
	/// </para>
	/// <para>
	/// The <c>ipv6_mreq</c> structure and the <c>IPPROTO_IPV6</c> level socket options that use this structure are only valid on
	/// datagram and raw sockets (the socket type must be <c>SOCK_DGRAM</c> or <c>SOCK_RAW</c>).
	/// </para>
	/// <para>
	/// It is recommended that a local IPv6 interface index always be specified in the <c>ipv6mr_interface</c> member of the
	/// <c>ipv6_mreq</c> structure, rather than use the default interface. This is particularly important on computers with multiple
	/// network interfaces and multiple public IPv6 addresses.
	/// </para>
	/// <para>
	/// The default interface used for IPv6 multicast is determined by the networking stack in Windows. On Windows Vista and later, an
	/// application can determine the default interface used for IPv6 multicast using the GetIpForwardTable2 function to retrieve the
	/// IPv6 routing table. The network interface with the lowest value for the routing metric for a destination IPv6 multicast address
	/// (the FF00::/8 IPv6 address block) is the default interface for IPv6 multicast. The routing table can also be displayed from the
	/// command prompt with the following command:
	/// </para>
	/// <para><c>route print</c></para>
	/// <para>
	/// The IPV6_MULTICAST_IF socket option can be used to set the default interface to send IPv6 multicast packets. This socket option
	/// does not change the default interface used to receive IPv6 multicast packets.
	/// </para>
	/// <para>
	/// A typical IPv6 multicast application would use the IPV6_ADD_MEMBERSHIP or <c>IPV6_JOIN_GROUP</c> socket option with the
	/// <c>ipv6_mreq</c> structure to join a multicast group and listen for multicast packets on a specific interface. The
	/// <c>IPV6_MULTICAST_IF</c> socket option would be used to set the interface to send IPv6 multicast packets to the multicast group.
	/// The most common scenario would be a multicast application that listens and sends on the same interface for a multicast group.
	/// Multiple sockets might be used by a multicast application with one socket for listening and one or more sockets for sending.
	/// </para>
	/// <para>
	/// On the Microsoft Windows Software Development Kit (SDK) released for Windows Vista and later, the organization of header files
	/// has changed and the <c>ipv6_mreq</c> structure is defined in the <c>Ws2ipdef.h</c> header file which is automatically included in
	/// the <c>Ws2tcpip.h</c> header file. The <c>Ws2ipdef.h</c> header files should never be used directly.
	/// </para>
	/// <para>
	/// <c>Note</c> The <c>PIP6_MREQ</c> derived structure is only defined on the Windows SDK released with Windows Vista and later. The
	/// GROUP_REQ and the GROUP_SOURCE_REQ structures and are the preferred socket options for multicast programming on Windows Vista and later.
	/// </para>
	/// </remarks>
	// https://docs.microsoft.com/en-us/windows/win32/api/ws2ipdef/ns-ws2ipdef-ipv6_mreq typedef struct ipv6_mreq { IN6_ADDR
	// ipv6mr_multiaddr; ULONG ipv6mr_interface; } IPV6_MREQ, *PIPV6_MREQ;
	[PInvokeData("ws2ipdef.h", MSDNShortId = "NS:ws2ipdef.ipv6_mreq")]
	[StructLayout(LayoutKind.Sequential)]
	public struct IPV6_MREQ
	{
		/// <summary>The address of the IPv6 multicast group.</summary>
		public IN6_ADDR ipv6mr_multiaddr;

		/// <summary>
		/// The interface index of the local interface on which the multicast group should be joined or dropped. If this member specifies
		/// an interface index of 0, the default multicast interface is used.
		/// </summary>
		public uint ipv6mr_interface;
	}

	/// <summary>The SOCKADDR_IN6 structure specifies a transport address and port for the AF_INET6 address family.</summary>
	/// <remarks>
	/// <para>
	/// All of the data in the SOCKADDR_IN6 structure, except for the address family, must be specified in network-byte-order (big-endian).
	/// </para>
	/// <para>
	/// The size of the SOCKADDR_IN6 structure is too large to fit in the memory space that is provided by a SOCKADDR structure. For a
	/// structure that is guaranteed to be large enough to contain a transport address for all possible address families, see SOCKADDR_STORAGEa&gt;.
	/// </para>
	/// </remarks>
	// https://docs.microsoft.com/en-us/windows/win32/api/ws2ipdef/ns-ws2ipdef-sockaddr_in6_lh typedef struct sockaddr_in6 {
	// ADDRESS_FAMILY sin6_family; USHORT sin6_port; ULONG sin6_flowinfo; IN6_ADDR sin6_addr; union { ULONG sin6_scope_id; SCOPE_ID
	// sin6_scope_struct; }; } SOCKADDR_IN6_LH, *PSOCKADDR_IN6_LH, *LPSOCKADDR_IN6_LH;
	[PInvokeData("ws2ipdef.h", MSDNShortId = "ef2955d2-5dc1-420b-a9e0-32a584059d5a")]
	[StructLayout(LayoutKind.Sequential, Pack = 2)]
	public struct SOCKADDR_IN6
	{
		/// <summary>The address family for the transport address. This member should always be set to AF_INET6.</summary>
		public ADDRESS_FAMILY sin6_family;

		/// <summary>A transport protocol port number.</summary>
		public ushort sin6_port;

		/// <summary>The IPv6 flow information.</summary>
		public uint sin6_flowinfo;

		/// <summary>An IN6_ADDR structure that contains an IPv6 transport address.</summary>
		public IN6_ADDR sin6_addr;

		/// <summary>A ULONG representation of the IPv6 scope identifier that is defined in the <c>sin6_scope_struct</c> member.</summary>
		public uint sin6_scope_id;

		/// <summary>Initializes a new instance of the <see cref="SOCKADDR_IN6"/> struct.</summary>
		/// <param name="addr">A byte array that contains an IPv6 transport address.</param>
		/// <param name="scope_id">
		/// A ULONG representation of the IPv6 scope identifier that is defined in the <c>sin6_scope_struct</c> member.
		/// </param>
		/// <param name="port">A transport protocol port number.</param>
		public SOCKADDR_IN6(byte[] addr, uint scope_id, ushort port = 0) : this(new IN6_ADDR(addr), scope_id, port)
		{
		}

		/// <summary>Initializes a new instance of the <see cref="SOCKADDR_IN6"/> struct.</summary>
		/// <param name="addr">An IN6_ADDR structure that contains an IPv6 transport address.</param>
		/// <param name="scope_id">
		/// A ULONG representation of the IPv6 scope identifier that is defined in the <c>sin6_scope_struct</c> member.
		/// </param>
		/// <param name="port">A transport protocol port number.</param>
		public SOCKADDR_IN6(IN6_ADDR addr, uint scope_id, ushort port = 0)
		{
			sin6_family = ADDRESS_FAMILY.AF_INET6;
			sin6_port = port;
			sin6_flowinfo = 0;
			sin6_addr = addr;
			sin6_scope_id = scope_id;
		}

		/// <summary>Initializes a new instance of the <see cref="SOCKADDR_IN6"/> struct from a <see cref="SOCKADDR_IN"/>.</summary>
		/// <param name="v4">The IPv4 socket address.</param>
		public SOCKADDR_IN6(SOCKADDR_IN v4) : this(new IN6_ADDR(v4.sin_addr), 0, v4.sin_port) { }

		/// <summary>Performs an implicit conversion from <see cref="IN6_ADDR"/> to <see cref="SOCKADDR_IN6"/>.</summary>
		/// <param name="addr">The address.</param>
		/// <returns>The resulting <see cref="SOCKADDR_IN6"/> instance from the conversion.</returns>
		public static implicit operator SOCKADDR_IN6(IN6_ADDR addr) => new(addr, 0);

		/// <summary>Represents an IPv6 anycast socket address.</summary>
		public static readonly SOCKADDR_IN6 IN6ADDR_ANY = new() { sin6_family = ADDRESS_FAMILY.AF_INET6, sin6_addr = IN6_ADDR.Unspecified };

		/// <summary>Represents an IPv6 LOOPBACK socket address.</summary>
		public static readonly SOCKADDR_IN6 IN6ADDR_LOOPBACK = new() { sin6_family = ADDRESS_FAMILY.AF_INET6, sin6_addr = IN6_ADDR.Loopback };

		/// <inheritdoc/>
		public override string ToString() => $"{sin6_addr}" + (sin6_scope_id == 0 ? "" : "%" + sin6_scope_id.ToString()) + $":{sin6_port}";
	}

	/// <summary>
	/// The <c>SOCKADDR_IN6_PAIR</c> structure contains pointers to a pair of IP addresses that represent a source and destination
	/// address pair.
	/// </summary>
	/// <remarks>
	/// <para>The <c>SOCKADDR_IN6_PAIR</c> structure is defined on Windows Vista and later.</para>
	/// <para>
	/// Any IPv4 addresses in the <c>SOCKADDR_IN6_PAIR</c> structure must be represented in the IPv4-mapped IPv6 address format which
	/// enables an IPv6 only application to communicate with an IPv4 node. For more information on the IPv4-mapped IPv6 address format,
	/// see Dual-Stack Sockets.
	/// </para>
	/// <para>The <c>SOCKADDR_IN6_PAIR</c> structure is used by the CreateSortedAddressPairs function.</para>
	/// <para>Note that the Ws2ipdef.h header file is automatically included in Ws2tcpip.h header file, and should never be used directly.</para>
	/// </remarks>
	// https://docs.microsoft.com/en-us/windows/desktop/api/ws2ipdef/ns-ws2ipdef-_sockaddr_in6_pair typedef struct _sockaddr_in6_pair {
	// PSOCKADDR_IN6 SourceAddress; PSOCKADDR_IN6 DestinationAddress; } SOCKADDR_IN6_PAIR, *PSOCKADDR_IN6_PAIR;
	[PInvokeData("ws2ipdef.h", MSDNShortId = "0265f8e0-8b35-4d9d-bf22-e98e9ff36a17")]
	[StructLayout(LayoutKind.Sequential)]
	public struct SOCKADDR_IN6_PAIR
	{
		/// <summary>The source address</summary>
		private readonly IntPtr _SourceAddress;

		/// <summary>The destination address</summary>
		private readonly IntPtr _DestinationAddress;

		/// <summary>
		/// A pointer to an IP source address represented as a SOCKADDR_IN6 structure. The address family is in host byte order and the
		/// IPv6 address, port, flow information, and zone ID are in network byte order.
		/// </summary>
		/// <value>The source address.</value>
		public SOCKADDR_IN6 SourceAddress => _SourceAddress.ToStructure<SOCKADDR_IN6>();

		/// <summary>
		/// A pointer to an IP source address represented as a SOCKADDR_IN6 structure. The address family is in host byte order and the
		/// IPv6 address, port, flow information, and zone ID are in network byte order.
		/// </summary>
		/// <value>The destination address.</value>
		public SOCKADDR_IN6 DestinationAddress => _DestinationAddress.ToStructure<SOCKADDR_IN6>();

		/// <summary>Performs an implicit conversion from <see cref="SOCKADDR_IN6_PAIR"/> to <see cref="SOCKADDR_IN6_PAIR_NATIVE"/>.</summary>
		/// <param name="unmgd">The unmanaged value.</param>
		/// <returns>The resulting <see cref="SOCKADDR_IN6_PAIR_NATIVE"/> instance from the conversion.</returns>
		public static implicit operator SOCKADDR_IN6_PAIR_NATIVE(SOCKADDR_IN6_PAIR unmgd) =>
			new()
			{ SourceAddress = unmgd.SourceAddress, DestinationAddress = unmgd.DestinationAddress };

		/// <summary>Converts to string.</summary>
		/// <returns>A <see cref="System.String"/> that represents this instance.</returns>
		/// <inheritdoc/>
		public override string ToString() => $"{SourceAddress} : {DestinationAddress}";
	}

	/// <summary>
	/// The <c>SOCKADDR_IN6_PAIR</c> structure contains pointers to a pair of IP addresses that represent a source and destination
	/// address pair.
	/// </summary>
	/// <remarks>
	/// <para>The <c>SOCKADDR_IN6_PAIR</c> structure is defined on Windows Vista and later.</para>
	/// <para>
	/// Any IPv4 addresses in the <c>SOCKADDR_IN6_PAIR</c> structure must be represented in the IPv4-mapped IPv6 address format which
	/// enables an IPv6 only application to communicate with an IPv4 node. For more information on the IPv4-mapped IPv6 address format,
	/// see Dual-Stack Sockets.
	/// </para>
	/// <para>The <c>SOCKADDR_IN6_PAIR</c> structure is used by the CreateSortedAddressPairs function.</para>
	/// <para>Note that the Ws2ipdef.h header file is automatically included in Ws2tcpip.h header file, and should never be used directly.</para>
	/// </remarks>
	// https://docs.microsoft.com/en-us/windows/desktop/api/ws2ipdef/ns-ws2ipdef-_sockaddr_in6_pair typedef struct _sockaddr_in6_pair {
	// PSOCKADDR_IN6 SourceAddress; PSOCKADDR_IN6 DestinationAddress; } SOCKADDR_IN6_PAIR, *PSOCKADDR_IN6_PAIR;
	[PInvokeData("ws2ipdef.h", MSDNShortId = "0265f8e0-8b35-4d9d-bf22-e98e9ff36a17")]
	[StructLayout(LayoutKind.Sequential)]
	public struct SOCKADDR_IN6_PAIR_NATIVE
	{
		/// <summary>
		/// A pointer to an IP source address represented as a SOCKADDR_IN6 structure. The address family is in host byte order and the
		/// IPv6 address, port, flow information, and zone ID are in network byte order.
		/// </summary>
		public SOCKADDR_IN6 SourceAddress;

		/// <summary>
		/// A pointer to an IP source address represented as a SOCKADDR_IN6 structure. The address family is in host byte order and the
		/// IPv6 address, port, flow information, and zone ID are in network byte order.
		/// </summary>
		public SOCKADDR_IN6 DestinationAddress;

		/// <summary>Converts to string.</summary>
		/// <returns>A <see cref="System.String"/> that represents this instance.</returns>
		/// <inheritdoc/>
		public override string ToString() => $"{SourceAddress} : {DestinationAddress}";
	}

	/// <summary>The <c>SOCKADDR_INET</c> union contains an IPv4, an IPv6 address, or an address family.</summary>
	/// <remarks>
	/// <para>The <c>SOCKADDR_INET</c> union is defined on Windows Vista and later.</para>
	/// <para>
	/// The <c>SOCKADDR_INET</c> union is a convenience structure for accessing an IPv4 address, an IPv6 address, or the IP address
	/// family without having to cast the sockaddr structure.
	/// </para>
	/// <para>The <c>SOCKADDR_INET</c> union is the data type of the <c>Prefix</c> member in the IP_ADDRESS_PREFIX structure</para>
	/// <para>Note that the Ws2ipdef.h header file is automatically included in Ws2tcpip.h header file, and should never be used directly.</para>
	/// </remarks>
	// https://docs.microsoft.com/en-us/windows/win32/api/ws2ipdef/ns-ws2ipdef-sockaddr_inet typedef union _SOCKADDR_INET { SOCKADDR_IN
	// Ipv4; SOCKADDR_IN6 Ipv6; ADDRESS_FAMILY si_family; } SOCKADDR_INET, *PSOCKADDR_INET;
	[PInvokeData("ws2ipdef.h", MSDNShortId = "7278dcb4-65c6-4aea-a474-cb7fae4d7672")]
	[StructLayout(LayoutKind.Explicit)]
	public struct SOCKADDR_INET : IEquatable<SOCKADDR_INET>, IEquatable<SOCKADDR_IN>, IEquatable<SOCKADDR_IN6>
	{
		/// <summary>
		/// An IPv4 address represented as a SOCKADDR_IN structure containing the address family and the IPv4 address. The address
		/// family is in host byte order and the IPv4 address is in network byte order.
		/// <para>
		/// On the Windows SDK released for Windows Vista and later, the organization of header files has changed and the SOCKADDR_IN
		/// structure is defined in the Ws2def.h header file. Note that the Ws2def.h header file is automatically included in
		/// Winsock2.h, and should never be used directly.
		/// </para>
		/// </summary>
		[FieldOffset(0)]
		public SOCKADDR_IN Ipv4;

		/// <summary>
		/// An IPv6 address represented as a SOCKADDR_IN6 structure containing the address family and the IPv6 address. The address
		/// family is in host byte order and the IPv6 address is in network byte order.
		/// <para>
		/// On the Windows SDK released for Windows Vista and later, the organization of header files has changed and the SOCKADDR_IN6
		/// structure is defined in the Ws2def.h header file. Note that the Ws2def.h header file is automatically included in
		/// Winsock2.h, and should never be used directly.
		/// </para>
		/// </summary>
		[FieldOffset(0)]
		public SOCKADDR_IN6 Ipv6;

		/// <summary>
		/// The address family.
		/// <para>
		/// Possible values for the address family are listed in the Ws2def.h header file. Note that the values for the AF_ address
		/// family and PF_ protocol family constants are identical (for example, AF_INET and PF_INET), so either constant can be
		/// used.The Ws2def.h header file is automatically included in Winsock2.h, and should never be used directly.
		/// </para>
		/// </summary>
		[FieldOffset(0)]
		public ADDRESS_FAMILY si_family;

		/// <summary>Gets the size of the actual address (not necessarily the size of the structure).</summary>
		public int Size => si_family == ADDRESS_FAMILY.AF_INET ? Marshal.SizeOf(typeof(SOCKADDR_IN)) : Marshal.SizeOf(typeof(SOCKADDR_IN6));

		/// <summary>Specifies whether this instance is equal to the specified object.</summary>
		/// <param name="other">The object to test for equality.</param>
		/// <returns><see langword="true"/> if <paramref name="other"/> is equal to this instance.</returns>
		public bool Equals(SOCKADDR_INET other) => (si_family == ADDRESS_FAMILY.AF_INET && Ipv4.Equals(other.Ipv4)) || (si_family == ADDRESS_FAMILY.AF_INET6 && Ipv6.Equals(other.Ipv6));

		/// <summary>Specifies whether this instance is equal to the specified object.</summary>
		/// <param name="other">The object to test for equality.</param>
		/// <returns><see langword="true"/> if <paramref name="other"/> is equal to this instance.</returns>
		public bool Equals(SOCKADDR_IN other) => si_family == ADDRESS_FAMILY.AF_INET && Ipv4.Equals(other);

		/// <summary>Specifies whether this instance is equal to the specified object.</summary>
		/// <param name="other">The object to test for equality.</param>
		/// <returns><see langword="true"/> if <paramref name="other"/> is equal to this instance.</returns>
		public bool Equals(SOCKADDR_IN6 other) => si_family == ADDRESS_FAMILY.AF_INET6 && Ipv6.Equals(other);

		/// <summary>Performs an implicit conversion from <see cref="SOCKADDR_IN"/> to <see cref="SOCKADDR_INET"/>.</summary>
		/// <param name="address">The address.</param>
		/// <returns>The resulting <see cref="SOCKADDR_INET"/> instance from the conversion.</returns>
		public static implicit operator SOCKADDR_INET(SOCKADDR_IN address) => new() { Ipv4 = address };

		/// <summary>Performs an implicit conversion from <see cref="SOCKADDR_IN6"/> to <see cref="SOCKADDR_INET"/>.</summary>
		/// <param name="address">The address.</param>
		/// <returns>The resulting <see cref="SOCKADDR_INET"/> instance from the conversion.</returns>
		public static implicit operator SOCKADDR_INET(SOCKADDR_IN6 address) => new() { Ipv6 = address };

		/// <summary>Performs an explicit conversion from <see cref="System.Net.IPEndPoint"/> to <see cref="SOCKADDR_INET"/>.</summary>
		/// <param name="address">The address.</param>
		/// <returns>The result of the conversion.</returns>
		public static explicit operator SOCKADDR_INET(System.Net.IPEndPoint address)
		{
			if (address.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork)
				return new() { Ipv4 = new SOCKADDR_IN(new(address.Address.GetAddressBytes()), (ushort)address.Port) };
			return new() { Ipv6 = new SOCKADDR_IN6(address.Address.GetAddressBytes(), (uint)address.Address.ScopeId, (ushort)address.Port) };
		}

		/// <summary>Converts to string.</summary>
		/// <returns>A <see cref="System.String"/> that represents this instance.</returns>
		public override string ToString()
		{
			var sb = new System.Text.StringBuilder($"{si_family}");
			if (si_family == ADDRESS_FAMILY.AF_INET)
				sb.Append(":").Append(Ipv4);
			else if (si_family == ADDRESS_FAMILY.AF_INET6)
				sb.Append(":").Append(Ipv6);
			return sb.ToString();
		}
	}
}