WNetAddConnection4W function (winnetwk.h)

The WNetAddConnection4 function makes a connection to a network resource. The function can redirect a local device to the network resource.

The WNetAddConnection4 function is similar to the WNetAddConnection3 function. The main difference is that WNetAddConnection4 has an additional parameter that allows the caller to specify an extendable property bag of parameters. The WNetAddConnection2, WNetAddConnection3, and WNetAddConnection4 functions supersede the WNetAddConnection function.

Syntax

DWORD WNetAddConnection4W(
  HWND           hwndOwner,
  LPNETRESOURCEW lpNetResource,
  PVOID          pAuthBuffer,
  DWORD          cbAuthBuffer,
  DWORD          dwFlags,
  PBYTE          lpUseOptions,
  DWORD          cbUseOptions
);

Parameters

hwndOwner

A handle to a window that the provider of network resources can use as an owner window for dialog boxes. Use this parameter if you set the CONNECT_INTERACTIVE value in the dwFlags parameter.

The hwndOwner parameter can be NULL. If it is, a call to WNetAddConnection4 is equivalent to calling the WNetAddConnection2 function.

lpNetResource

A pointer to a NETRESOURCE structure that specifies details of the proposed connection, such as information about the network resource, the local device, and the network resource provider.

You must specify the following members of the NETRESOURCE structure.

The WNetAddConnection4 function ignores the other members of the NETRESOURCE structure.

pAuthBuffer

A pointer to a buffer that contains authentication information for the network resource. The format of this buffer is provider-specific. If the buffer is NULL, the default authentication information is used.

cbAuthBuffer

The size, in bytes, of the authentication information buffer pointed to by the pAuthBuffer parameter. If pAuthBuffer is NULL, this parameter can be zero.

dwFlags

A set of connection options. The following values are currently defined:

lpUseOptions

A pointer to a buffer that contains a set of options for the connection. The format of this buffer is provider-specific. If the buffer is NULL, the default options are used.

cbUseOptions

The size, in bytes, of the options buffer pointed to by the lpUseOptions parameter. If lpUseOptions is NULL, this parameter can be zero.

Return value

If the function succeeds, the return value is NO_ERROR.

If the function fails, the return value is a system error code, such as one of the following values:

Remarks

The WNetUseConnection function is similar to the WNetAddConnection4 function. The main difference is that WNetUseConnection can automatically select an unused local device to redirect to the network resource.

On Windows Server 2003 and Windows XP, the WNet functions create and delete network drive letters in the MS-DOS device namespace associated with a logon session because MS-DOS devices are identified by AuthenticationID (a locally unique identifier, or LUID, associated with a logon session.) This can affect applications that call one of the WNet functions to create a network drive letter under one user logon, but query for existing network drive letters under a different user logon. An example of this situation could be when a user's second logon is created within a logon session, for example, by calling the CreateProcessAsUser function, and the second logon runs an application that calls the GetLogicalDrives function. The call to the GetLogicalDrives function does not return network drive letters created by WNet function calls under the first logon. Note that in the preceding example the first logon session still exists, and the example could apply to any logon session, including a Terminal Services session. For more information, see Defining an MS-DOS Device Name.

On Windows Server 2003 and Windows XP, if a service that runs as LocalSystem calls the WNetAddConnection4 function, then the mapped drive is visible to all user logon sessions.

For Microsoft network providers, the lpRemoteName member of the NETRESOURCE structure pointed to by the lpNetResource parameter can contain an IPv4 address in dotted-decimal notation. An example for a share might be the following:

\\192.168.1.1\share

For Microsoft network providers on Windows Vista and later, the lpRemoteName member of the NETRESOURCE structure pointed to by the lpNetResource parameter can contain an IPv6 address. However, the IPv6 literal format must be used so that the IPv6 address is parsed correctly. An IPv6 literal address is of the form:

ipv6-address with the ':' characters replaced by '-' characters followed by the ".ipv6-literal.net" string.

For example, for the following IPv6 address:

2001:4898:9:3:c069:aa97:fe76:2449

an example for a share might be the following:

\\2001-4898-9-3-c069-aa97-fe76-2449.ipv6-literal.net\share

Other network providers may support the lpRemoteName member of the NETRESOURCE structure pointed to by the lpNetResource parameter that contains an IPv4 or IPv6 address, but this is up to specific network provider.

Windows 7 and Windows Server 2008 R2: If the WNetAddConnection4 function is called with explicit user credentials specified in the pAuthBuffer to establish a connection with a network resource on a specific server and then called again with the parameter as NULL (to use the default credential information) to the same server, the call with fail. The error returned will be ERROR_BAD_USERNAME or ERROR_INVALID_PASSWORD.

Requirements

See also

• WNetAddConnection
• WNetAddConnection2
• WNetAddConnection3