Question

Using the following code, more or less copy-pasted from the MSDN example of
GetAdaptersAddresses, I get the return value 122, which means ERROR_INSUFFICIENT_BUFFER (according to this system error code list).

ULONG outBufLen = 150000;   // Tried for different (large) values here...
PIP_ADAPTER_ADDRESSES pAddresses = (IP_ADAPTER_ADDRESSES *) malloc(outBufLen);
DWORD dwRetVal = GetAdaptersAddresses(AF_INET, 0, NULL, pAddresses, &outBufLen);
// ....
free(pAddresses);

The documentation of GetAdaptersAddresses does not list ERROR_INSUFFICIENT_BUFFER as one of the expected return values. (It lists ERROR_BUFFER_OVERFLOW, which should adjust outBufLen to the needed value, but that remains unchanged).

Using GetAdaptersInfo instead leads to the same symptoms.

This error does not occur on my development machine, but on one virtual and one real clean Windows 7 x86 SP1 installation (added the VC++ redistributables).

As a c++ newbie, am I doing something wrong? What could cause this error and how to fix it? =)

Answer 1

Visual Studio deployed a library named “IPHLPAPI.dll” together with my project which caused the problem. Deleting this file solved it.

Why this was the case is subject to further research =)