GetNetworkParams function - Windows API Reference

Overview

The GetNetworkParams function retrieves the current network configuration information for the local computer.

It is part of the IP Helper API and is documented for Windows Desktop development.

Syntax

ULONG GetNetworkParams(
    PFIXED_INFO pFixedInfo,
    PULONG       pOutBufLen
);

Parameters

Name	Type	Description
pFixedInfo	PFIXED_INFO	Pointer to a `FIXED_INFO` structure that receives the network configuration data.
pOutBufLen	PULONG	Pointer to a variable that specifies the size of the buffer pointed to by `pFixedInfo`. On return it receives the actual size needed.

Return Value

Returns NO_ERROR (0) on success. On failure, the function returns a Windows error code such as ERROR_BUFFER_OVERFLOW if the supplied buffer is too small.

Remarks

The caller must allocate a buffer large enough to hold the FIXED_INFO structure and any associated strings.
If ERROR_BUFFER_OVERFLOW is returned, the pOutBufLen variable contains the required buffer size.
Call GetNetworkParams after the network configuration changes to obtain updated information.

Example

#include <windows.h>
#include <iphlpapi.h>
#include <stdio.h>

#pragma comment(lib, "iphlpapi.lib")

int main() {
    DWORD dwSize = 0;
    GetNetworkParams(NULL, &dwSize); // Get required size
    FIXED_INFO *pFixedInfo = (FIXED_INFO *)malloc(dwSize);
    if (pFixedInfo == NULL) {
        printf("Memory allocation failed.\n");
        return 1;
    }

    DWORD dwRetVal = GetNetworkParams(pFixedInfo, &dwSize);
    if (dwRetVal == NO_ERROR) {
        printf("Host Name: %s\n", pFixedInfo->HostName);
        printf("Domain Name: %s\n", pFixedInfo->DomainName);
        printf("DNS Servers:\n");
        IP_ADDR_STRING *pDns = &pFixedInfo->DnsServerList;
        while (pDns) {
            printf("  %s\n", pDns->IpAddress.String);
            pDns = pDns->Next;
        }
    } else {
        printf("GetNetworkParams failed with error %d\n", dwRetVal);
    }

    free(pFixedInfo);
    return 0;
}