fs/cifs/Kconfig - third_party/linux - Git at Google


            
            # SPDX-License-Identifier: GPL-2.0-only

            
            config CIFS

            
            	tristate "SMB3 and CIFS support (advanced network filesystem)"

            
            	depends on INET

            
            	select NLS

            
            	select CRYPTO

            
            	select CRYPTO_MD5

            
            	select CRYPTO_SHA256

            
            	select CRYPTO_SHA512

            
            	select CRYPTO_CMAC

            
            	select CRYPTO_HMAC

            
            	select CRYPTO_AEAD2

            
            	select CRYPTO_CCM

            
            	select CRYPTO_GCM

            
            	select CRYPTO_ECB

            
            	select CRYPTO_AES

            
            	select KEYS

            
            	select DNS_RESOLVER

            
            	select ASN1

            
            	select OID_REGISTRY

            
            	help

            
            	  This is the client VFS module for the SMB3 family of NAS protocols,

            
            	  (including support for the most recent, most secure dialect SMB3.1.1)

            
            	  as well as for earlier dialects such as SMB2.1, SMB2 and the older

            
            	  Common Internet File System (CIFS) protocol.  CIFS was the successor

            
            	  to the original dialect, the Server Message Block (SMB) protocol, the

            
            	  native file sharing mechanism for most early PC operating systems.


            	  The SMB3 protocol is supported by most modern operating systems

            
            	  and NAS appliances (e.g. Samba, Windows 10, Windows Server 2016,

            
            	  MacOS) and even in the cloud (e.g. Microsoft Azure).

            
            	  The older CIFS protocol was included in Windows NT4, 2000 and XP (and

            
            	  later) as well by Samba (which provides excellent CIFS and SMB3

            
            	  server support for Linux and many other operating systems). Use of

            
            	  dialects older than SMB2.1 is often discouraged on public networks.

            
            	  This module also provides limited support for OS/2 and Windows ME

            
            	  and similar very old servers.


            	  This module provides an advanced network file system client

            
            	  for mounting to SMB3 (and CIFS) compliant servers.  It includes

            
            	  support for DFS (hierarchical name space), secure per-user

            
            	  session establishment via Kerberos or NTLM or NTLMv2, RDMA

            
            	  (smbdirect), advanced security features, per-share encryption,

            
            	  directory leases, safe distributed caching (oplock), optional packet

            
            	  signing, Unicode and other internationalization improvements.


            	  In general, the default dialects, SMB3 and later, enable 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. SMB2/SMB3 mount options are also

            
            	  slightly simpler (compared to CIFS) due to protocol improvements.


            	  If you need to mount to Samba, Azure, Macs or Windows from this machine, say Y.


            config CIFS_STATS2

            
            	bool "Extended statistics"

            
            	depends on CIFS

            
            	default y

            
            	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 Documentation/admin-guide/cifs/usage.rst

            
            	  for more details. These additional statistics may have a minor effect

            
            	  on performance and memory utilization.


            	  If unsure, say Y.


            config CIFS_ALLOW_INSECURE_LEGACY

            
            	bool "Support legacy servers which use less secure dialects"

            
            	depends on CIFS

            
            	default y

            
            	help

            
            	  Modern dialects, SMB2.1 and later (including SMB3 and 3.1.1), have

            
            	  additional security features, including protection against

            
            	  man-in-the-middle attacks and stronger crypto hashes, so the use

            
            	  of legacy dialects (SMB1/CIFS and SMB2.0) is discouraged.


            	  Disabling this option prevents users from using vers=1.0 or vers=2.0

            
            	  on mounts with cifs.ko


            	  If unsure, say Y.


            config CIFS_UPCALL

            
            	bool "Kerberos/SPNEGO advanced session setup"

            
            	depends on CIFS

            
            	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 Y.


            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 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 Y.


            config CIFS_POSIX

            
            	bool "CIFS POSIX Extensions"

            
            	depends on CIFS && CIFS_ALLOW_INSECURE_LEGACY && 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_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_DEBUG_DUMP_KEYS

            
            	bool "Dump encryption keys for offline decryption (Unsafe)"

            
            	depends on CIFS_DEBUG

            
            	help

            
            	  Enabling this will dump the encryption and decryption keys

            
            	  used to communicate on an encrypted share connection on the

            
            	  console. This allows Wireshark to decrypt and dissect

            
            	  encrypted network captures. Enable this carefully.

            
            	  If unsure, say N.


            config CIFS_DFS_UPCALL

            
            	bool "DFS feature support"

            
            	depends on CIFS

            
            	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 in order to reconnect to

            
            	  servers if their addresses change or for implicit mounts of

            
            	  DFS junction points. If unsure, say Y.


            config CIFS_SWN_UPCALL

            
            	bool "SWN feature support"

            
            	depends on CIFS

            
            	help

            
            	  The Service Witness Protocol (SWN) is used to get notifications

            
            	  from a highly available server of resource state changes. This

            
            	  feature enables an upcall mechanism for CIFS which contacts a

            
            	  userspace daemon to establish the DCE/RPC connection to retrieve

            
            	  the cluster available interfaces and resource change notifications.

            
            	  If unsure, say Y.


            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_SMB_DIRECT

            
            	bool "SMB Direct support"

            
            	depends on CIFS=m && INFINIBAND && INFINIBAND_ADDR_TRANS || CIFS=y && INFINIBAND=y && INFINIBAND_ADDR_TRANS=y

            
            	help

            
            	  Enables SMB Direct support for SMB 3.0, 3.02 and 3.1.1.

            
            	  SMB Direct allows transferring SMB packets over RDMA. If unsure,

            
            	  say Y.


            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.


            config CIFS_ROOT

            
            	bool "SMB root file system (Experimental)"

            
            	depends on CIFS=y && IP_PNP

            
            	help

            
            	  Enables root file system support over SMB protocol.


            	  Most people say N here.
	# SPDX-License-Identifier: GPL-2.0-only
	config CIFS
	tristate "SMB3 and CIFS support (advanced network filesystem)"
	depends on INET
	select NLS
	select CRYPTO
	select CRYPTO_MD5
	select CRYPTO_SHA256
	select CRYPTO_SHA512
	select CRYPTO_CMAC
	select CRYPTO_HMAC
	select CRYPTO_AEAD2
	select CRYPTO_CCM
	select CRYPTO_GCM
	select CRYPTO_ECB
	select CRYPTO_AES
	select KEYS
	select DNS_RESOLVER
	select ASN1
	select OID_REGISTRY
	help
	This is the client VFS module for the SMB3 family of NAS protocols,
	(including support for the most recent, most secure dialect SMB3.1.1)
	as well as for earlier dialects such as SMB2.1, SMB2 and the older
	Common Internet File System (CIFS) protocol. CIFS was the successor
	to the original dialect, the Server Message Block (SMB) protocol, the
	native file sharing mechanism for most early PC operating systems.

	The SMB3 protocol is supported by most modern operating systems
	and NAS appliances (e.g. Samba, Windows 10, Windows Server 2016,
	MacOS) and even in the cloud (e.g. Microsoft Azure).
	The older CIFS protocol was included in Windows NT4, 2000 and XP (and
	later) as well by Samba (which provides excellent CIFS and SMB3
	server support for Linux and many other operating systems). Use of
	dialects older than SMB2.1 is often discouraged on public networks.
	This module also provides limited support for OS/2 and Windows ME
	and similar very old servers.

	This module provides an advanced network file system client
	for mounting to SMB3 (and CIFS) compliant servers. It includes
	support for DFS (hierarchical name space), secure per-user
	session establishment via Kerberos or NTLM or NTLMv2, RDMA
	(smbdirect), advanced security features, per-share encryption,
	directory leases, safe distributed caching (oplock), optional packet
	signing, Unicode and other internationalization improvements.

	In general, the default dialects, SMB3 and later, enable 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. SMB2/SMB3 mount options are also
	slightly simpler (compared to CIFS) due to protocol improvements.

	If you need to mount to Samba, Azure, Macs or Windows from this machine, say Y.

	config CIFS_STATS2
	bool "Extended statistics"
	depends on CIFS
	default y
	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 Documentation/admin-guide/cifs/usage.rst
	for more details. These additional statistics may have a minor effect
	on performance and memory utilization.

	If unsure, say Y.

	config CIFS_ALLOW_INSECURE_LEGACY
	bool "Support legacy servers which use less secure dialects"
	depends on CIFS
	default y
	help
	Modern dialects, SMB2.1 and later (including SMB3 and 3.1.1), have
	additional security features, including protection against
	man-in-the-middle attacks and stronger crypto hashes, so the use
	of legacy dialects (SMB1/CIFS and SMB2.0) is discouraged.

	Disabling this option prevents users from using vers=1.0 or vers=2.0
	on mounts with cifs.ko

	If unsure, say Y.

	config CIFS_UPCALL
	bool "Kerberos/SPNEGO advanced session setup"
	depends on CIFS
	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 Y.

	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 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 Y.

	config CIFS_POSIX
	bool "CIFS POSIX Extensions"
	depends on CIFS && CIFS_ALLOW_INSECURE_LEGACY && 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_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_DEBUG_DUMP_KEYS
	bool "Dump encryption keys for offline decryption (Unsafe)"
	depends on CIFS_DEBUG
	help
	Enabling this will dump the encryption and decryption keys
	used to communicate on an encrypted share connection on the
	console. This allows Wireshark to decrypt and dissect
	encrypted network captures. Enable this carefully.
	If unsure, say N.

	config CIFS_DFS_UPCALL
	bool "DFS feature support"
	depends on CIFS
	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 in order to reconnect to
	servers if their addresses change or for implicit mounts of
	DFS junction points. If unsure, say Y.

	config CIFS_SWN_UPCALL
	bool "SWN feature support"
	depends on CIFS
	help
	The Service Witness Protocol (SWN) is used to get notifications
	from a highly available server of resource state changes. This
	feature enables an upcall mechanism for CIFS which contacts a
	userspace daemon to establish the DCE/RPC connection to retrieve
	the cluster available interfaces and resource change notifications.
	If unsure, say Y.

	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_SMB_DIRECT
	bool "SMB Direct support"
	depends on CIFS=m && INFINIBAND && INFINIBAND_ADDR_TRANS \|\| CIFS=y && INFINIBAND=y && INFINIBAND_ADDR_TRANS=y
	help
	Enables SMB Direct support for SMB 3.0, 3.02 and 3.1.1.
	SMB Direct allows transferring SMB packets over RDMA. If unsure,
	say Y.

	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.

	config CIFS_ROOT
	bool "SMB root file system (Experimental)"
	depends on CIFS=y && IP_PNP
	help
	Enables root file system support over SMB protocol.

	Most people say N here.