private static unsafe IPHostEntry CreateHostEntry(Interop.libc.hostent *hostent)
{
string hostName = null;
if (hostent->h_name != null)
{
hostName = Marshal.PtrToStringAnsi((IntPtr)hostent->h_name);
}
int numAddresses;
for (numAddresses = 0; hostent->h_addr_list[numAddresses] != null; numAddresses++)
{
}
IPAddress[] ipAddresses;
if (numAddresses == 0)
{
ipAddresses = Array.Empty <IPAddress>();
}
else
{
ipAddresses = new IPAddress[numAddresses];
for (int i = 0; i < numAddresses; i++)
{
Debug.Assert(hostent->h_addr_list[i] != null);
ipAddresses[i] = new IPAddress(*(int *)hostent->h_addr_list[i]);
}
}
int numAliases;
for (numAliases = 0; hostent->h_aliases[numAliases] != null; numAliases++)
{
}
string[] aliases;
if (numAliases == 0)
{
aliases = Array.Empty <string>();
}
else
{
aliases = new string[numAliases];
for (int i = 0; i < numAliases; i++)
{
Debug.Assert(hostent->h_aliases[i] != null);
aliases[i] = Marshal.PtrToStringAnsi((IntPtr)hostent->h_aliases[i]);
}
}
return(new IPHostEntry
{
HostName = hostName,
AddressList = ipAddresses,
Aliases = aliases
});
}
public static unsafe IPHostEntry GetHostByName(string hostName)
{
Interop.libc.hostent *hostent = Interop.libc.gethostbyname(hostName);
if (hostent == null)
{
int errno = Marshal.GetLastWin32Error();
throw new InternalSocketException(GetSocketErrorForErrno(errno), errno);
}
return(CreateHostEntry(hostent));
}
public static unsafe IPHostEntry GetHostByAddr(IPAddress addr)
{
// TODO #2891: Optimize this (or decide if this legacy code can be removed):
byte[] addressBytes = addr.GetAddressBytes();
var address = new Interop.libc.in_addr {
s_addr = unchecked ((uint)BitConverter.ToInt32(addressBytes, 0))
};
Interop.libc.hostent *hostent = Interop.libc.gethostbyaddr(&address, (uint)sizeof(Interop.libc.in_addr), Interop.libc.AF_INET);
if (hostent == null)
{
int errno = Marshal.GetLastWin32Error();
throw new InternalSocketException(GetSocketErrorForErrno(errno), errno);
}
return(CreateHostEntry(hostent));
}
private static unsafe bool TryGetHostByAddr(Interop.libc.in_addr address, byte *buffer, int bufferSize, Interop.libc.hostent *hostent, Interop.libc.hostent **result)
{
int errno;
int err = Interop.libc.gethostbyaddr_r(&address, (uint)sizeof(Interop.libc.in_addr), Interop.libc.AF_INET, hostent, buffer, (IntPtr)bufferSize, result, &errno);
switch (Interop.Sys.ConvertErrorPlatformToPal(err))
{
case 0:
return(true);
case Interop.Error.ERANGE:
return(false);
default:
throw new InternalSocketException(GetSocketErrorForErrno(errno), errno);
}
}
private static unsafe bool TryGetHostByName(string hostName, byte *buffer, int bufferSize, Interop.libc.hostent *hostent, Interop.libc.hostent **result)
{
int errno;
int err = Interop.libc.gethostbyname_r(hostName, hostent, buffer, (IntPtr)bufferSize, result, &errno);
switch (Interop.Sys.ConvertErrorPlatformToPal(err))
{
case 0:
return(true);
case Interop.Error.ERANGE:
return(false);
default:
throw new InternalSocketException(GetSocketErrorForErrno(errno), errno);
}
}
