linux-libre/fs/cifs/Kconfig

config CIFS
	tristate "CIFS support (advanced network filesystem, SMBFS successor)"
	depends on INET
	select NLS
	select CRYPTO
	select CRYPTO_MD4
	select CRYPTO_MD5
	select CRYPTO_HMAC
	select CRYPTO_ARC4
	select CRYPTO_ECB
	select CRYPTO_DES
	select CRYPTO_SHA256
	select CRYPTO_CMAC
	help
	  This is the client VFS module for the Common Internet File System
	  (CIFS) protocol which is the successor to the Server Message Block
	  (SMB) protocol, the native file sharing mechanism for most early
	  PC operating systems.  The CIFS protocol is fully supported by
	  file servers such as Windows 2000 (including Windows 2003, Windows 2008,
	  NT 4 and Windows XP) as well by Samba (which provides excellent CIFS
	  server support for Linux and many other operating systems). Limited
	  support for OS/2 and Windows ME and similar servers is provided as
	  well.

	  The module also provides optional support for the followon
	  protocols for CIFS including SMB3, which enables
	  useful performance and security features (see the description
	  of CONFIG_CIFS_SMB2).

	  The cifs module provides an advanced network file system
	  client for mounting to CIFS compliant servers.  It includes
	  support for DFS (hierarchical name space), secure per-user
	  session establishment via Kerberos or NTLM or NTLMv2,
	  safe distributed caching (oplock), optional packet
	  signing, Unicode and other internationalization improvements.
	  If you need to mount to Samba or Windows from this machine, say Y.

config CIFS_STATS
        bool "CIFS statistics"
        depends on CIFS
        help
          Enabling this option will cause statistics for each server share
	  mounted by the cifs client to be displayed in /proc/fs/cifs/Stats

config CIFS_STATS2
	bool "Extended statistics"
	depends on CIFS_STATS
	help
	  Enabling this option will allow more detailed statistics on SMB
	  request timing to be displayed in /proc/fs/cifs/DebugData and also
	  allow optional logging of slow responses to dmesg (depending on the
	  value of /proc/fs/cifs/cifsFYI, see fs/cifs/README for more details).
	  These additional statistics may have a minor effect on performance
	  and memory utilization.

	  Unless you are a developer or are doing network performance analysis
	  or tuning, say N.

config CIFS_WEAK_PW_HASH
	bool "Support legacy servers which use weaker LANMAN security"
	depends on CIFS
	help
	  Modern CIFS servers including Samba and most Windows versions
	  (since 1997) support stronger NTLM (and even NTLMv2 and Kerberos)
	  security mechanisms. These hash the password more securely
	  than the mechanisms used in the older LANMAN version of the
	  SMB protocol but LANMAN based authentication is needed to
	  establish sessions with some old SMB servers.

	  Enabling this option allows the cifs module to mount to older
	  LANMAN based servers such as OS/2 and Windows 95, but such
	  mounts may be less secure than mounts using NTLM or more recent
	  security mechanisms if you are on a public network.  Unless you
	  have a need to access old SMB servers (and are on a private
	  network) you probably want to say N.  Even if this support
	  is enabled in the kernel build, LANMAN authentication will not be
	  used automatically. At runtime LANMAN mounts are disabled but
	  can be set to required (or optional) either in
	  /proc/fs/cifs (see fs/cifs/README for more detail) or via an
	  option on the mount command. This support is disabled by
	  default in order to reduce the possibility of a downgrade
	  attack.

	  If unsure, say N.

config CIFS_UPCALL
	bool "Kerberos/SPNEGO advanced session setup"
	depends on CIFS && KEYS
	select DNS_RESOLVER
	help
	  Enables an upcall mechanism for CIFS which accesses userspace helper
	  utilities to provide SPNEGO packaged (RFC 4178) Kerberos tickets
	  which are needed to mount to certain secure servers (for which more
	  secure Kerberos authentication is required). If unsure, say N.

config CIFS_XATTR
        bool "CIFS extended attributes"
        depends on CIFS
        help
          Extended attributes are name:value pairs associated with inodes by
          the kernel or by users (see the attr(5) manual page, or visit
          <http://acl.bestbits.at/> for details).  CIFS maps the name of
          extended attributes beginning with the user namespace prefix
          to SMB/CIFS EAs. EAs are stored on Windows servers without the
          user namespace prefix, but their names are seen by Linux cifs clients
          prefaced by the user namespace prefix. The system namespace
          (used by some filesystems to store ACLs) is not supported at
          this time.

          If unsure, say N.

config CIFS_POSIX
        bool "CIFS POSIX Extensions"
        depends on CIFS_XATTR
        help
          Enabling this option will cause the cifs client to attempt to
	  negotiate a newer dialect with servers, such as Samba 3.0.5
	  or later, that optionally can handle more POSIX like (rather
	  than Windows like) file behavior.  It also enables
	  support for POSIX ACLs (getfacl and setfacl) to servers
	  (such as Samba 3.10 and later) which can negotiate
	  CIFS POSIX ACL support.  If unsure, say N.

config CIFS_ACL
	  bool "Provide CIFS ACL support"
	  depends on CIFS_XATTR && KEYS
	  help
	    Allows fetching CIFS/NTFS ACL from the server.  The DACL blob
	    is handed over to the application/caller.  See the man
	    page for getcifsacl for more information.

config CIFS_DEBUG
	bool "Enable CIFS debugging routines"
	default y
	depends on CIFS
	help
	   Enabling this option adds helpful debugging messages to
	   the cifs code which increases the size of the cifs module.
	   If unsure, say Y.
config CIFS_DEBUG2
	bool "Enable additional CIFS debugging routines"
	depends on CIFS_DEBUG
	help
	   Enabling this option adds a few more debugging routines
	   to the cifs code which slightly increases the size of
	   the cifs module and can cause additional logging of debug
	   messages in some error paths, slowing performance. This
	   option can be turned off unless you are debugging
	   cifs problems.  If unsure, say N.

config CIFS_DFS_UPCALL
	  bool "DFS feature support"
	  depends on CIFS && KEYS
	  select DNS_RESOLVER
	  help
	    Distributed File System (DFS) support is used to access shares
	    transparently in an enterprise name space, even if the share
	    moves to a different server.  This feature also enables
	    an upcall mechanism for CIFS which contacts userspace helper
	    utilities to provide server name resolution (host names to
	    IP addresses) which is needed for implicit mounts of DFS junction
	    points. If unsure, say N.

config CIFS_NFSD_EXPORT
	  bool "Allow nfsd to export CIFS file system"
	  depends on CIFS && BROKEN
	  help
	   Allows NFS server to export a CIFS mounted share (nfsd over cifs)

config CIFS_SMB2
	bool "SMB2 and SMB3 network file system support"
	depends on CIFS && INET
	select NLS
	select KEYS
	select FSCACHE
	select DNS_RESOLVER

	help
	  This enables support for the Server Message Block version 2
	  family of protocols, including SMB3.  SMB3 support is
	  enabled on mount by specifying "vers=3.0" in the mount
	  options. These protocols are the successors to the popular
	  CIFS and SMB network file sharing protocols. SMB3 is the
	  native file sharing mechanism for the more recent
	  versions of Windows (Windows 8 and Windows 2012 and
	  later) and Samba server and many others support SMB3 well.
	  In general SMB3 enables better performance, security
	  and features, than would be possible with CIFS (Note that
	  when mounting to Samba, due to the CIFS POSIX extensions,
	  CIFS mounts can provide slightly better POSIX compatibility
	  than SMB3 mounts do though). Note that SMB2/SMB3 mount
	  options are also slightly simpler (compared to CIFS) due
	  to protocol improvements.

config CIFS_SMB311
	bool "SMB3.1.1 network file system support (Experimental)"
	depends on CIFS_SMB2 && INET

	help
	  This enables experimental support for the newest, SMB3.1.1, dialect.
	  This dialect includes improved security negotiation features.
	  If unsure, say N

config CIFS_FSCACHE
	  bool "Provide CIFS client caching support"
	  depends on CIFS=m && FSCACHE || CIFS=y && FSCACHE=y
	  help
	    Makes CIFS FS-Cache capable. Say Y here if you want your CIFS data
	    to be cached locally on disk through the general filesystem cache
	    manager. If unsure, say N.