GetUnicastIpAddressEntry function (netioapi.h)

The GetUnicastIpAddressEntry function retrieves information for an existing unicast IP address entry on the local computer.

Syntax

IPHLPAPI_DLL_LINKAGE _NETIOAPI_SUCCESS_ NETIOAPI_API GetUnicastIpAddressEntry(
  [in, out] PMIB_UNICASTIPADDRESS_ROW Row
);

Parameters

[in, out] Row

A pointer to a MIB_UNICASTIPADDRESS_ROW structure entry for a unicast IP address entry. On successful return, this structure will be updated with the properties for an existing unicast IP address.

Return value

If the function succeeds, the return value is NO_ERROR.

If the function fails, the return value is one of the following error codes.

Remarks

The GetUnicastIpAddressEntry function is defined on Windows Vista and later.

The GetUnicastIpAddressEntry function is normally used to retrieve an existing MIB_UNICASTIPADDRESS_ROW structure entry to be modified. An application can then change the members in the MIB_UNICASTIPADDRESS_ROW entry it wishes to modify, and then call the SetUnicastIpAddressEntry function.

On input, the Address member in the MIB_UNICASTIPADDRESS_ROW structure pointed to by the Row parameter must be initialized to a valid unicast IPv4 or IPv6 address. The si_family member of the SOCKADDR_INET structure in the Address member must be initialized to either AF_INET or AF_INET6 and the related Ipv4 or Ipv6 member of the SOCKADDR_INET structure must be set to a valid unicast IP address. In addition, at least one of the following members in the MIB_UNICASTIPADDRESS_ROW structure pointed to the Row parameter must be initialized: the InterfaceLuid or InterfaceIndex.

The fields are used in the order listed above. So if the InterfaceLuid is specified, then this member is used to determine the interface. If no value is set for the InterfaceLuid member (the value of this member is set to zero), then the InterfaceIndex member is next used to determine the interface.

On output when the call is successful, GetUnicastIpAddressEntry retrieves the other properties for the unicast IP address and fills out the MIB_UNICASTIPADDRESS_ROW structure pointed to by the Row parameter.

The GetUnicastIpAddressTable function can be called to enumerate the unicast IP address entries on a local computer.

Examples

The following example retrieves a unicast IP address entry specified on the command line and prints some values from the retrieved MIB_UNICASTIPADDRESS_ROW structure.

#ifndef UNICODE
#define UNICODE
#endif

#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif

#include <Windows.h.>
#include <winsock2.h>
#include <ws2tcpip.h>
#include <ws2ipdef.h>
#include <iphlpapi.h>
#include <stdio.h>
#include <stdlib.h>

// Need to link with Iphlpapi.lib and Ws2_32.lib
#pragma comment (lib, "iphlpapi.lib")
#pragma comment (lib, "Ws2_32.lib")

void PrintUnicastIpAddress(PMIB_UNICASTIPADDRESS_ROW pIpRow);

int __cdecl wmain(int argc, WCHAR **argv)
{

    // Declare and initialize variables

    ULONG Result = 0;
    ULONG ifIndex;

    // default to unspecified address family
    ULONG addressFamily = AF_UNSPEC;

    IN_ADDR Ipv4Addr;
    IN6_ADDR Ipv6Addr;

    MIB_UNICASTIPADDRESS_ROW ipRow = {0};
    
    // Validate the parameters
    if (argc < 4) {
        wprintf(L"usage: %s <AddressFamily> <IPAddress> <InterfaceIndex>\n", argv[0]);
        wprintf(L"   Gets the UnicastIpAddressEntry for an AddressFamily,\n");
        wprintf(L"     Interface Index, and IP address\n");
        wprintf(L"   Examples\n");
        wprintf(L"     Get the IPv4 loopback at interface index=1\n");
        wprintf(L"       %s 4 127.0.0.1 1\n", argv[0]);
        wprintf(L"     Get the IPv6 loopback at interface index=1\n");
        wprintf(L"       %s 6 ::1 1\n", argv[0]);
        exit(1);
    }

    if (_wtoi(argv[1]) == 4) {
        addressFamily = AF_INET;
        if (InetPtonW(addressFamily, argv[2], &Ipv4Addr) != 1) {
            wprintf(L"Unable to parse IPv4 address string: %s\n", argv[3]);
            exit(1);
        }
    } else if (_wtoi(argv[1]) == 6) {
        addressFamily = AF_INET6;
        if (InetPton(addressFamily, argv[2], &Ipv6Addr) != 1) {
            wprintf(L"Unable to parse IPv6 address string: %s\n", argv[3]);
            exit(1);
        }
    }

    ifIndex = _wtoi(argv[3]);

    ipRow.Address.si_family = (ADDRESS_FAMILY) addressFamily;
    ipRow.InterfaceIndex = ifIndex;

    if (addressFamily == AF_INET) {
        ipRow.Address.si_family = AF_INET;
        memcpy(&ipRow.Address.Ipv4.sin_addr, &Ipv4Addr, sizeof (IN_ADDR));
    }
    if (addressFamily == AF_INET6) {
        ipRow.Address.si_family = AF_INET6;
        memcpy(&ipRow.Address.Ipv6.sin6_addr, &Ipv6Addr, sizeof (IN6_ADDR));
    }

    Result = GetUnicastIpAddressEntry(&ipRow);
    if (Result != NO_ERROR) {
        wprintf(L"GetUnicastIpAddressEntry returned error: %lu\n", Result);
        exit(1);
    }
    PrintUnicastIpAddress(&ipRow);
    
    exit(0);
}

void PrintUnicastIpAddress(PMIB_UNICASTIPADDRESS_ROW pipRow)
{

    WCHAR Ipv4String[16] = { 0 };
    WCHAR Ipv6String[46] = { 0 };

    // Print some variables from the rows in the table
    wprintf(L"AddressFamily:\t\t\t ");
    switch (pipRow->Address.si_family) {
    case AF_INET:
        wprintf(L"IPv4\n");
        if (InetNtop(AF_INET, &pipRow->Address.Ipv4.sin_addr, Ipv4String, 16) !=
            NULL)
            wprintf(L"IPv4 Address:\t\t\t %ws\n", Ipv4String);
        break;
    case AF_INET6:
        wprintf(L"IPv6\n");
        if (InetNtop(AF_INET6, &pipRow->Address.Ipv6.sin6_addr, Ipv6String, 46)
            != NULL)
            wprintf(L"IPv6 Address:\t\t\t %s\n", Ipv6String);
        break;
    default:
        wprintf(L"Other: %d\n", pipRow->Address.si_family);
        break;
    }

    wprintf(L"Interface LUID NetLuidIndex:\t %lu\n",
           pipRow->InterfaceLuid.Info.NetLuidIndex);
    wprintf(L"Interface LUID IfType:\t\t ");
    switch (pipRow->InterfaceLuid.Info.IfType) {
    case IF_TYPE_OTHER:
        wprintf(L"Other\n");
        break;
    case IF_TYPE_ETHERNET_CSMACD:
        wprintf(L"Ethernet\n");
        break;
    case IF_TYPE_ISO88025_TOKENRING:
        wprintf(L"Token ring\n");
        break;
    case IF_TYPE_PPP:
        wprintf(L"PPP\n");
        break;
    case IF_TYPE_SOFTWARE_LOOPBACK:
        wprintf(L"Software loopback\n");
        break;
    case IF_TYPE_ATM:
        wprintf(L"ATM\n");
        break;
    case IF_TYPE_IEEE80211:
        wprintf(L"802.11 wireless\n");
        break;
    case IF_TYPE_TUNNEL:
        wprintf(L"Tunnel encapsulation\n");
        break;
    case IF_TYPE_IEEE1394:
        wprintf(L"IEEE 1394 (Firewire)\n");
        break;
    default:
        wprintf(L"Unknown: %d\n", pipRow->InterfaceLuid.Info.IfType);
        break;
    }

    wprintf(L"Interface Index:\t\t %lu\n", pipRow->InterfaceIndex);

    wprintf(L"Prefix Origin:\t\t\t ");
    switch (pipRow->PrefixOrigin) {
    case IpPrefixOriginOther:
        wprintf(L"IpPrefixOriginOther\n");
        break;
    case IpPrefixOriginManual:
        wprintf(L"IpPrefixOriginManual\n");
        break;
    case IpPrefixOriginWellKnown:
        wprintf(L"IpPrefixOriginWellKnown\n");
        break;
    case IpPrefixOriginDhcp:
        wprintf(L"IpPrefixOriginDhcp\n");
        break;
    case IpPrefixOriginRouterAdvertisement:
        wprintf(L"IpPrefixOriginRouterAdvertisement\n");
        break;
    case IpPrefixOriginUnchanged:
        wprintf(L"IpPrefixOriginUnchanged\n");
        break;
    default:
        wprintf(L"Unknown: %d\n", pipRow->PrefixOrigin);
        break;
    }

    wprintf(L"Suffix Origin:\t\t\t ");
    switch (pipRow->SuffixOrigin) {
    case IpSuffixOriginOther:
        wprintf(L"IpSuffixOriginOther\n");
        break;
    case IpSuffixOriginManual:
        wprintf(L"IpSuffixOriginManual\n");
        break;
    case IpSuffixOriginWellKnown:
        wprintf(L"IpSuffixOriginWellKnown\n");
        break;
    case IpSuffixOriginDhcp:
        wprintf(L"IpSuffixOriginDhcp\n");
        break;
    case IpSuffixOriginLinkLayerAddress:
        wprintf(L"IpSuffixOriginLinkLayerAddress\n");
        break;
    case IpSuffixOriginRandom:
        wprintf(L"IpSuffixOriginRandom\n");
        break;
    case IpSuffixOriginUnchanged:
        wprintf(L"IpSuffixOriginUnchanged\n");
        break;
    default:
        wprintf(L"Unknown: %d\n", pipRow->SuffixOrigin);
        break;
    }

    wprintf(L"Valid Lifetime:\t\t\t 0x%x (%u)\n",
           pipRow->ValidLifetime, pipRow->ValidLifetime);

    wprintf(L"Preferred Lifetime:\t\t 0x%x (%u)\n",
           pipRow->PreferredLifetime, pipRow->PreferredLifetime);

    wprintf(L"OnLink PrefixLength:\t\t %lu\n", pipRow->OnLinkPrefixLength);

    wprintf(L"Skip As Source:\t\t\t ");
    if (pipRow->SkipAsSource)
        wprintf(L"Yes\n");
    else
        wprintf(L"No\n");

    wprintf(L"Dad State:\t\t\t ");
    switch (pipRow->DadState) {
    case IpDadStateInvalid:
        wprintf(L"IpDadStateInvalid\n");
        break;
    case IpDadStateTentative:
        wprintf(L"IpDadStateTentative\n");
        break;
    case IpDadStateDuplicate:
        wprintf(L"IpDadStateDuplicate\n");
        break;
    case IpDadStateDeprecated:
        wprintf(L"IpDadStateDeprecated\n");
        break;
    case IpDadStatePreferred:
        wprintf(L"IpDadStatePreferred\n");
        break;
    default:
        wprintf(L"Unknown: %d\n", pipRow->DadState);
        break;
    }

    wprintf(L"\n");
}

Requirements

See also

CreateUnicastIpAddressEntry

DeleteUnicastIpAddressEntry

GetUnicastIpAddressTable

IP Helper Function Reference

InitializeUnicastIpAddressEntry

MIB_UNICASTIPADDRESS_ROW

MIB_UNICASTIPADDRESS_TABLE

NotifyUnicastIpAddressChange

SetUnicastIpAddressEntry