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diff --git a/docs-xml/Samba4-HOWTO/protocol.xml b/docs-xml/Samba4-HOWTO/protocol.xml deleted file mode 100644 index f2961116e0..0000000000 --- a/docs-xml/Samba4-HOWTO/protocol.xml +++ /dev/null @@ -1,204 +0,0 @@ -<chapter id="protocol"> - <title>The SMB/CIFS protocol</title> - - <!-- - Some parts shamelessly borrowed from myself. - Original on http://jelmer.vernstok.nl/publications/cifs-developments.pdf - --> - - <para> - "SMB" (also known as "CIFS") is a - file-sharing protocol that has been used since the mid-eighties. - Most people know SMB as the protocol behind the "Network Neighbourhood" - and remote printing in Windows. - </para> - - <para> - Several parts of the protocol are not discussed in this chapter, such - as mailslots, browsing and dfs, to prevent it from getting too complex. - CIFS internals are documented in detail in <citation>Hertel, 2003</citation>. - </para> - - - <sect1> - <title>History</title> - - <sect2> - <title>Invention by IBM</title> - - <para> - SMB is not very old, but it has a long history of modifications and extensions. - The original protocol was meant to run over ``NetBIOS'', which was the - name of the DOS interface to a very simple LAN system developed by IBM. - NetBIOS was developed because SNA, IBM's other main - protocol at the time, was much too advanced for use in DOS. - </para> - - <para> - The NetBIOS API in these days (early eighties) was nothing more then the - interface to a very simple link-layer protocol - over which several protocols, including SMB, were used. It could do reads and - writes to services on remote hosts, which were identified by case-insensitive - names, and discover all available hosts and services. - </para> - - <para> - Dr. Barry Feigenbau, an IBM employee, invented the core of the original SMB protocol, - which he initially named after himself: ``BAF''. He later changed the name to - be ``SMB'' (for ``Server Message Block''). Every packet in the protocol - starts with a byte $0xFF$ and these three letters. - </para> - - <para> - IBM, Microsoft, 3Com and Intel made up the rest of the initial protocol - together. The commands the protocol supported at this stage were basically - a mirror of the DOS File IO API calls, which meant the protocol wasn't very - efficient. The protocol also lacked authentication support. Everybody on the - network could do reads and writes, which meant this protocol - wasn't very suitable for large enterprises. - </para> - - <para> - NetBIOS is an API that has had various implementations; there is - NetBIOS over TCP/IP (NBT), NetBIOS over IPX, NetBIOS over SNA and - even NetBIOS over DECNEt. Mostly used these days is - NetBIOS over TCP (NBT). - </para> - - <para> - This is also were things are starting to get hairy. Since NetBIOS identifies - hosts by their name, NetBIOS clients had to start doing IP broadcasts to - figure out the IP of the host they had to connect to. Several schemes were - introduced to do name lookups crossing subnet boundaries, using name servers, - etc. We're basically emulating a NetBIOS LAN in order to be able to run SMB. - </para> - - <para> - Doing NetBIOS over IP is not very sane, however, the NBT implementation itself - in Windows isn't very nice either. It has horrible - limits, special exceptions, several broken schemes for looking up - names (including two kinds of name servers). NetBIOS and NetBIOS over TCP/IP - are described in RFC1001 and RFC1002. - </para> - </sect2> - - <sect2> - <title>The various incarnations of SMB</title> - - <para>Over the years, several usage models for SMB have been developed. While SMB originally started out as a file sharing protocol, it was later extended to include support for network management and other network services - as well.</para> - - <para> - One of the reasons for the various "upgrades" of the SMB - protocol is the fact that networks have become larger - and larger and with them the need for privilege separation - and scalability has increased. - </para> - - <sect3> - <title>DOS</title> - - <para> - The original model in which SMB was used was as a - simple file-sharing service in a NetBIOS-environment. - </para> - - <para> - File sharing worked basically by specifying a list of directories that had - to be shared and what name they had to be shared under ("shares"). Eventually, - one could password-protect a share. At most one password per share could be set. - </para> - </sect3> - - <sect3> - <title>Windows For Workgroups</title> - - <para> - After the ``CORE'' dialect, - IBM and Microsoft implemented a new dialect known as ``LANMAN''. - This dialect was used by Windows for - Workgroups, OS/2 and Windows 9x which all know it under a different name. A - 'virtual' file system was also added, which was used for doing remote function - calls (RAP, for ``Remote Administration Protocol''). - </para> - - <para> - Computers are grouped into "Workgroups" in this model. Everybody is equal to - the others and there is no central point of control. - </para> - </sect3> - - <sect3> - <title>Windows NT</title> - <para> - For Windows NT, yet another dialect was added, named 'NT'. The NT dialect - had it's own set of file I/O functions (similar to the NT File I/O API) - and it had support for yet another way of doing remote function calls: - DCE/RPC. RPC's are used for DCOM and several of the subsystems in NT - that can be accessed remotely (registry, printing, user management, logging - on, etc). - </para> - - <para> - Windows NT works with a new concept for grouping computers called ``domains''<footnote>In the protocol, domains are actually an upgraded version of a workgroup</footnote>. Each computer is member of exactly one domain. There are several roles a computer can have in the domain: PDC (primary domain controller, the "manager" of the domain, that coordinates all authentication and authorization), BDC (Backup domain controller, in case the PDC goes down) or just a regular domain member. The PDC decides who is to be a member of the domain. - </para> - </sect3> - - <sect3> - <title>Windows 2000</title> - <para> - In Windows NT 5 (marketing name: Windows 2000), NetBIOS-less SMB was - introduced. This means SMB is used directly over TCP port 445 instead of - via NetBIOS over TCP/IP. DNS - is used for looking up machine names. - </para> - - <para>Windows 2000 was also the first operating system from Microsoft - that had support for Active Directory. Active Directory is very - similar to the "domain" concept used by NT4, though it - is implemented differently (using modified open protocols), - and has some additional features (one of the most important ones being decentralized). - </para> - - <para> - Active directory no longer uses a central point of authority - and there are fewer limits to the size of a domain. Several - DC's can exist, so there is no longer a single point of - failure as well as better scalability. - </para> - </sect3> - </sect2> - - <sect2> - <title>Samba versions and their support for the SMB models</title> - - <sect3> - <title>Samba 2.2</title> - - <para>Full CORE and Workgroup support. Somewhat basic - NT4-style support.</para> - </sect3> - - <sect3> - <title>Samba 3.0</title> - - <para>Full CORE and Workgroup support. Almost complete - NT4-style support. - </para> - </sect3> - - <sect3> - <title>Samba 3.2</title> - - <para>FIXME</para> - </sect3> - - <sect3> - <title>Samba 4.0</title> - - <para>Full CORE, Workgroup, NT4 and ADS support.</para> - - </sect3> - </sect2> - </sect1> -</chapter> |