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diff --git a/docs/textdocs/Recent-FAQs.txt b/docs/textdocs/Recent-FAQs.txt new file mode 100644 index 0000000000..feed127827 --- /dev/null +++ b/docs/textdocs/Recent-FAQs.txt @@ -0,0 +1,286 @@ +Contributor: Samba-bugs@samba.org +Date: July 5, 1998 +Status: Current + +============================================================================= +Subject: Recent FAQ answers to common questions / problems +============================================================================= +Contents: NetWkstaUserLogon + Not listening for calling name + System Error 1240 + Trapdoor UID + User Access Control + Using NT to Browse Samba Shares + setup.exe and 16 bit programs + smbclient -N + +NetWkstaUserLogon +================= +FAQ answer about the new password server code: + +In 1.9.18 you can disable the NetWkstaUserLogon call at compile time +in local.h and from 1.9.18p3 you can now disable it from an option in +your smb.conf. + +The password server behaviour changed because we discovered that bugs +in some NT servers allowed anyone to login with no password if they +chose an account name that did not exist on the password server. The +NT password server was saying "yes, it's OK to login" even when the +account didn't exist at all! Adding the NetWkstaUserLogon call fixed +the problem, and follows the "recommended" method that MS have +recently documented for pass through authentication. + +The problem now is that some NT servers (in particular NT +workstation?) don't support the NetWkstaUserLogon call. The call also +doesn't work for accounts in trust relationships. + +The eventual solution for this will be to replace the password server +code in Samba with NT domain code as that is developed. For now you +have the choice of compiling Samba either with or without the +NetWkstaUserLogon call in the password server code. + +In 1.9.18p3 the following was added (copied from the 1.9.18p3 release +notes): + +In the [global] section of smb.conf : + +networkstation user login + +This code (submitted by Rob Nielsen) allows the code many people +were having problems with that queries an NT password server to +be turned off at runtime rather than compile time. Please see the +documentation in the smb.conf manual page for details. This is a +security option - it must only be turned off after checks have been +made to ensure that your NT password server does not suffer from the +bug this code was meant to protect against ! + +In 1.9.18 you can enable/disable this call in local.h. In 1.9.17p5 +you could apply the following patch. Applying this patch will make +the password server code behave like the code in earlier versions +of Samba. If you do this then please ensure that you test to see +that users are prevented from logging in if they give a bogus +username/password. You may have a NT server that is affected by the +bug that this code is designed to avoid. + + +--- password.c 1997/10/21 10:09:28 1.25.2.4 ++++ password.c 1997/12/31 06:43:06 +@@ -1619,6 +1619,7 @@ + } + + ++#if 0 + if (!cli_NetWkstaUserLogon(&cli,user,local_machine)) { + DEBUG(1,("password server %s failed NetWkstaUserLogon\n", cli.desthost)); + cli_tdis(&cli); +@@ -1638,6 +1639,7 @@ + cli_tdis(&cli); + return False; + } ++#endif + + DEBUG(3,("password server %s accepted the password\n", cli.desthost)); +=============================================================================== + +Not listening for calling name +============================== + +> Session request failed (131,129) with myname=HOBBES destname=CALVIN +> Not listening for calling name + +If you get this when talking to a Samba box then it means that your +global "hosts allow" or "hosts deny" settings are causing the Samba +server to refuse the connection. + +Look carefully at your "hosts allow" and "hosts deny" lines in the +global section of smb.conf. + +It can also be a problem with reverse DNS lookups not functioning +correctly, leading to the remote host identity not being able to +be confirmed, but that is less likely. +=============================================================================== + +System Error 1240 +================= +System error 1240 means that the client is refusing to talk +to a non-encrypting server. Microsoft changed WinNT in service +pack 3 to refuse to connect to servers that do not support +SMB password encryption. + +There are two main solutions: + +1) enable SMB password encryption in Samba. See ENCRYPTION.txt in the +Samba docs + +2) disable this new behaviour in NT. See WinNT.txt in the +Samba docs +=============================================================================== + +Trapdoor UID +============ +> Log message "you appear to have a trapdoor uid system" + +This can have several causes. It might be because you are using a uid +or gid of 65535 or -1. This is a VERY bad idea, and is a big security +hole. Check carefully in your /etc/passwd file and make sure that no +user has uid 65535 or -1. Especially check the "nobody" user, as many +broken systems are shipped with nobody setup with a uid of 65535. + +It might also mean that your OS has a trapdoor uid/gid system :-) + +This means that once a process changes effective uid from root to +another user it can't go back to root. Unfortunately Samba relies on +being able to change effective uid from root to non-root and back +again to implement its security policy. If your OS has a trapdoor uid +system this won't work, and several things in Samba may break. Less +things will break if you use user or server level security instead of +the default share level security, but you may still strike +problems. + +The problems don't give rise to any security holes, so don't panic, +but it does mean some of Samba's capabilities will be unavailable. +In particular you will not be able to connect to the Samba server as +two different uids at once. This may happen if you try to print as a +"guest" while accessing a share as a normal user. It may also affect +your ability to list the available shares as this is normally done as +the guest user. + +Complain to your OS vendor and ask them to fix their system. + +Note: the reason why 65535 is a VERY bad choice of uid and gid is that +it casts to -1 as a uid, and the setreuid() system call ignores (with +no error) uid changes to -1. This means any daemon attempting to run +as uid 65535 will actually run as root. This is not good! +=============================================================================== + +User Access Control +=================== +> In windows when i set up a share in "user mode" i get the message: +> "You cannot view the list of users at this time. Please try again later." +> +> I know you have lists of users for access and aliasing purposes, but i +> have read nothing to support the idea that these lists control the Domain +> Users List... + +Samba does NOT at this time support user mode access control for Window 9x +of for NT. This is a priority item and requires full implementation of the NT SMB +protocol calls. Samba-1.9.19 will go into alpha in about 2 months time and will +have a more full implementation of the NT SMB protocols to support Domain Client +interoperability. When we can see that this has been succesful we wil then implement +the NT SMB Server components. This will probably be released as Samba-2.0 + +Samba-1.9.18p5 is scheduled to go out within 14 days. This will close off the 1.9.18 +branch and then opens the way to progress 1.9.19. + +I hope this answers your concerns adequately. +=============================================================================== + +Using NT to Browse Samba Shares +=============================== +> WIN-NT workstations (nt4.0, service pack 3) +> samba with +> security = user +> encrypt passwords = yes +> guest account = guest +> +> start the explorer on a win-nt workstation and select network. I find +> my unix server running samba, but I can not see the list of shares +> unless I am a user, who is known in the smbpasswd of the unix machine. +> The guest account "guest" exists on my unix machine. For testing I even +> made him a regular user with a password. +> +> With my network monitor I can see, that the win-nt workstation uses the +> current login, to connect to IPC$ on the samba server +> (for example "administrator"), not the guest account. + +This is exactly how Windows NT works. You MUST have a valid account on the Windows +NT box you are trying to see the resource list on. If your currently logged in +account details do NOT match an account on the NT machine you are trying to access +then you will be presented with a logon box for that machine. When you enter the +name of an account on that machine / domain, together with a valid password then +the resource list is made available. If the account details are not correct then +no resource list is shown. + +Samba follows the behaviour of Windows NT exactly. + +Warning:Warning:Warning: +======================== +Samba can be compiled with the GUEST_SESSION_SETUP option at 0,1 or 2. +The default is 0. If this is set to 1 or 2 then Windows NT machines that DO NOT +have an account on the Samba server will see the resource list. The down side of this +is that legitimate users may then be refused access to their legitimate resources. +Setting this option creates serious security holes. DO NOT DO IT. Samba has the +value of this option set at 0 - NOT WITHOUT REASON!!!! + +******> Warning:Warning:Warning: ****> Do not tamper with this setting!!! +=============================================================================== + +setup.exe and 16 bit programs +============================= +Running 16 bit programs from Windows NT on a Samba mapped drive +--------------------------------------------------------------- + +The Windows NT redirector has a bug when running against a +Samba or Windows 95 mapped drive and attempting to run a +16 bit executable. + +The problem occurs when the pathname to a 16 bit executable +contains a non 8.3 filename complient directory component, +Windows NT will fail to load the program and complain it +cannot find the path to the program. + +It can be verified that this is a bug in Windows NT and +not Samba as the same problem can be reproduced exactly +when attempting to run the same program with the same +pathname from a Windows 95 server (ie. the problem still +exists even with no Samba server involved). + +Microsoft have been made aware of this problem, it is +unknown if they regard it as serious enough to provide +a fix for this. + +One of the reasons this problem is reported frequently +is that InstallShield setup.exe executables are frequently +written as 16 bit programs, and so hit this problem. + +As a workaround, you may create (on a Samba server at +least) a symbolic link with an 8.3 complient name to +the non 8.3 complient directory name, and then the 16 +bit program will run. Alternatively, use the 8.3 +complient mangled name to specify the path to run +the binary. + +This will be fixed when Samba adds the NT-specific +SMB calls (currently targeted for the next major +Samba release), as once the NT SMB calls are used +this problem no longer occurs (which is why the +problem doesn't occur when running against a drive +mapped to a Windows NT server). + +Regards, + + Jeremy Allison. + Samba Team. +=============================================================================== + +smbclient -N +============ +> When getting the list of shares available on a host using the command +> smbclient -N -L <server> +> the program always prompts for the password if the server is a Samba server. +> It also ignores the "-N" argument when querying some (but not all) of our +> NT servers. + +No, it does not ignore -N, it is just that your server rejected the +null password in the connection, so smbclient prompts for a password +to try again. + +To get the behaviour that you probably want use + smbclient -L host -U% + +this will set both the username and password to null, which is +an anonymous login for SMB. Using -N would only set the password +to null, and this is not accepted as an anonymous login for most +SMB servers. +=============================================================================== + |