void zen::loginNetworkShare(const Zstring& dirpathOrig, bool allowUserInteraction) //throw() - user interaction: show OS password prompt
{
/*
ATTENTION: it is not safe to retrieve UNC path via ::WNetGetConnection() for every type of network share:
network type |::WNetGetConnection rv | lpRemoteName | existing UNC path
-----------------------------|-------------------------|---------------------------------|----------------
inactive local network share | ERROR_CONNECTION_UNAVAIL| \\192.168.1.27\new2 | YES
WebDrive | NO_ERROR | \\Webdrive-ZenJu\GNU | NO
Box.net (WebDav) | NO_ERROR | \\www.box.net\DavWWWRoot\dav | YES
NetDrive | ERROR_NOT_CONNECTED | <empty> | NO
____________________________________________________________________________________________________________
Windows Login Prompt Naming Conventions:
network share: \\<server>\<share> e.g. \\WIN-XP\folder or \\192.168.1.50\folder
user account: <Domain>\<user> e.g. WIN-XP\Zenju or 192.168.1.50\Zenju
Windows Command Line:
- list *all* active network connections, including deviceless ones which are hidden in Explorer:
net use
- delete active connection:
net use /delete \\server\share
____________________________________________________________________________________________________________
Scenario: XP-shared folder is accessed by Win 7 over LAN with access limited to a certain user
Problems:
I. WNetAddConnection2() allows (at least certain) invalid credentials (e.g. username: a/password: a) and establishes an *unusable* connection
II. WNetAddConnection2() refuses to overwrite an existing (unusable) connection created in I), but shows prompt repeatedly
III. WNetAddConnection2() won't bring up the prompt if *wrong* credentials had been entered just recently, even with CONNECT_INTERACTIVE specified! => 2-step proccess
*/
auto connect = [&](NETRESOURCE& trgRes) //blocks heavily if network is not reachable!!!
{
//1. first try to connect without user interaction - blocks!
DWORD rv = ::WNetAddConnection2(&trgRes, //__in LPNETRESOURCE lpNetResource,
nullptr, //__in LPCTSTR lpPassword,
nullptr, //__in LPCTSTR lpUsername,
0); //__in DWORD dwFlags
//53L ERROR_BAD_NETPATH The network path was not found.
//67L ERROR_BAD_NET_NAME
//86L ERROR_INVALID_PASSWORD
//1219L ERROR_SESSION_CREDENTIAL_CONFLICT Multiple connections to a server or shared resource by the same user, using more than one user name, are not allowed. Disconnect all previous connections to the server or shared resource and try again.
//1326L ERROR_LOGON_FAILURE Logon failure: unknown user name or bad password.
//1236L ERROR_CONNECTION_ABORTED
if (somethingExists(trgRes.lpRemoteName)) //blocks!
return; //success: connection usable! -> don't care about "rv"
if (rv == ERROR_BAD_NETPATH || //like ERROR_PATH_NOT_FOUND
rv == ERROR_BAD_NET_NAME|| //like ERROR_FILE_NOT_FOUND
rv == ERROR_CONNECTION_ABORTED) //failed to connect to a network that existed not too long ago; will later return ERROR_BAD_NETPATH
return; //no need to show a prompt for an unreachable network device
//2. if first attempt failed, we need to *force* prompt by using CONNECT_PROMPT
if (allowUserInteraction)
{
//avoid problem II.)
DWORD rv2= ::WNetCancelConnection2(trgRes.lpRemoteName, //_In_ LPCTSTR lpName,
0, //_In_ DWORD dwFlags,
true); //_In_ BOOL fForce
//2250L ERROR_NOT_CONNECTED
//enforce login prompt
DWORD rv3 = ::WNetAddConnection2(&trgRes, // __in LPNETRESOURCE lpNetResource,
nullptr, // __in LPCTSTR lpPassword,
nullptr, // __in LPCTSTR lpUsername,
CONNECT_INTERACTIVE | CONNECT_PROMPT); //__in DWORD dwFlags
(void)rv2;
(void)rv3;
}
};
Zstring dirpath = removeLongPathPrefix(dirpathOrig);
trim(dirpath, true, false);
//1. locally mapped network share
if (dirpath.size() >= 2 && iswalpha(dirpath[0]) && dirpath[1] == L':')
{
Zstring driveLetter(dirpath.c_str(), 2); //e.g.: "Q:"
{
DWORD bufferSize = 10000;
std::vector<wchar_t> remoteNameBuffer(bufferSize);
//map local -> remote
//note: following function call does NOT block!
DWORD rv = ::WNetGetConnection(driveLetter.c_str(), //__in LPCTSTR lpLocalName in the form "<driveletter>:"
&remoteNameBuffer[0], //__out LPTSTR lpRemoteName,
&bufferSize); //__inout LPDWORD lpnLength
if (rv == ERROR_CONNECTION_UNAVAIL) //remoteNameBuffer will be filled nevertheless!
{
//ERROR_CONNECTION_UNAVAIL: network mapping is existing, but not connected
Zstring networkShare = &remoteNameBuffer[0];
if (!networkShare.empty())
{
NETRESOURCE trgRes = {};
trgRes.dwType = RESOURCETYPE_DISK;
trgRes.lpLocalName = const_cast<LPWSTR>(driveLetter.c_str()); //lpNetResource is marked "__in", seems WNetAddConnection2 is not const correct!
trgRes.lpRemoteName = const_cast<LPWSTR>(networkShare.c_str()); //
connect(trgRes); //blocks!
}
}
}
}
//2. deviceless network connection
else if (startsWith(dirpath, L"\\\\")) //UNC path
{
const Zstring networkShare = [&]() -> Zstring //extract prefix "\\server\share"
{
size_t pos = dirpath.find('\\', 2);
if (pos == Zstring::npos)
return Zstring();
pos = dirpath.find('\\', pos + 1);
return pos == Zstring::npos ? dirpath : Zstring(dirpath.c_str(), pos);
}();
if (!networkShare.empty())
{
//::WNetGetResourceInformation seems to fail with ERROR_BAD_NET_NAME even for existing unconnected network shares!
// => unconditionally try to connect to network share, seems we cannot reliably detect connection status otherwise
NETRESOURCE trgRes = {};
trgRes.dwType = RESOURCETYPE_DISK;
trgRes.lpRemoteName = const_cast<LPWSTR>(networkShare.c_str()); //trgRes is "__in"
connect(trgRes); //blocks!
}
}
}
