Kconfig revision 71c02863
1# SPDX-License-Identifier: GPL-2.0-only
2config CIFS
3	tristate "SMB3 and CIFS support (advanced network filesystem)"
4	depends on INET
5	select NLS
6	select CRYPTO
7	select CRYPTO_MD4
8	select CRYPTO_MD5
9	select CRYPTO_SHA256
10	select CRYPTO_SHA512
11	select CRYPTO_CMAC
12	select CRYPTO_HMAC
13	select CRYPTO_AEAD2
14	select CRYPTO_CCM
15	select CRYPTO_GCM
16	select CRYPTO_ECB
17	select CRYPTO_AES
18	select KEYS
19	select DNS_RESOLVER
20	select ASN1
21	select OID_REGISTRY
22	help
23	  This is the client VFS module for the SMB3 family of NAS protocols,
24	  (including support for the most recent, most secure dialect SMB3.1.1)
25	  as well as for earlier dialects such as SMB2.1, SMB2 and the older
26	  Common Internet File System (CIFS) protocol.  CIFS was the successor
27	  to the original dialect, the Server Message Block (SMB) protocol, the
28	  native file sharing mechanism for most early PC operating systems.
30	  The SMB3 protocol is supported by most modern operating systems
31	  and NAS appliances (e.g. Samba, Windows 10, Windows Server 2016,
32	  MacOS) and even in the cloud (e.g. Microsoft Azure).
33	  The older CIFS protocol was included in Windows NT4, 2000 and XP (and
34	  later) as well by Samba (which provides excellent CIFS and SMB3
35	  server support for Linux and many other operating systems). Use of
36	  dialects older than SMB2.1 is often discouraged on public networks.
37	  This module also provides limited support for OS/2 and Windows ME
38	  and similar very old servers.
40	  This module provides an advanced network file system client
41	  for mounting to SMB3 (and CIFS) compliant servers.  It includes
42	  support for DFS (hierarchical name space), secure per-user
43	  session establishment via Kerberos or NTLM or NTLMv2, RDMA
44	  (smbdirect), advanced security features, per-share encryption,
45	  directory leases, safe distributed caching (oplock), optional packet
46	  signing, Unicode and other internationalization improvements.
48	  In general, the default dialects, SMB3 and later, enable better
49	  performance, security and features, than would be possible with CIFS.
50	  Note that when mounting to Samba, due to the CIFS POSIX extensions,
51	  CIFS mounts can provide slightly better POSIX compatibility
52	  than SMB3 mounts. SMB2/SMB3 mount options are also
53	  slightly simpler (compared to CIFS) due to protocol improvements.
55	  If you need to mount to Samba, Azure, Macs or Windows from this machine, say Y.
57config CIFS_STATS2
58	bool "Extended statistics"
59	depends on CIFS
60	default y
61	help
62	  Enabling this option will allow more detailed statistics on SMB
63	  request timing to be displayed in /proc/fs/cifs/DebugData and also
64	  allow optional logging of slow responses to dmesg (depending on the
65	  value of /proc/fs/cifs/cifsFYI). See Documentation/admin-guide/cifs/usage.rst
66	  for more details. These additional statistics may have a minor effect
67	  on performance and memory utilization.
69	  If unsure, say Y.
72	bool "Support legacy servers which use less secure dialects"
73	depends on CIFS
74	default y
75	help
76	  Modern dialects, SMB2.1 and later (including SMB3 and 3.1.1), have
77	  additional security features, including protection against
78	  man-in-the-middle attacks and stronger crypto hashes, so the use
79	  of legacy dialects (SMB1/CIFS and SMB2.0) is discouraged.
81	  Disabling this option prevents users from using vers=1.0 or vers=2.0
82	  on mounts with cifs.ko
84	  If unsure, say Y.
86config CIFS_UPCALL
87	bool "Kerberos/SPNEGO advanced session setup"
88	depends on CIFS
89	help
90	  Enables an upcall mechanism for CIFS which accesses userspace helper
91	  utilities to provide SPNEGO packaged (RFC 4178) Kerberos tickets
92	  which are needed to mount to certain secure servers (for which more
93	  secure Kerberos authentication is required). If unsure, say Y.
95config CIFS_XATTR
96	bool "CIFS extended attributes"
97	depends on CIFS
98	help
99	  Extended attributes are name:value pairs associated with inodes by
100	  the kernel or by users (see the attr(5) manual page for details).
101	  CIFS maps the name of extended attributes beginning with the user
102	  namespace prefix to SMB/CIFS EAs.  EAs are stored on Windows
103	  servers without the user namespace prefix, but their names are
104	  seen by Linux cifs clients prefaced by the user namespace prefix.
105	  The system namespace (used by some filesystems to store ACLs) is
106	  not supported at this time.
108	  If unsure, say Y.
110config CIFS_POSIX
111	bool "CIFS POSIX Extensions"
113	help
114	  Enabling this option will cause the cifs client to attempt to
115	  negotiate a newer dialect with servers, such as Samba 3.0.5
116	  or later, that optionally can handle more POSIX like (rather
117	  than Windows like) file behavior.  It also enables
118	  support for POSIX ACLs (getfacl and setfacl) to servers
119	  (such as Samba 3.10 and later) which can negotiate
120	  CIFS POSIX ACL support.  If unsure, say N.
122config CIFS_DEBUG
123	bool "Enable CIFS debugging routines"
124	default y
125	depends on CIFS
126	help
127	  Enabling this option adds helpful debugging messages to
128	  the cifs code which increases the size of the cifs module.
129	  If unsure, say Y.
131config CIFS_DEBUG2
132	bool "Enable additional CIFS debugging routines"
133	depends on CIFS_DEBUG
134	help
135	  Enabling this option adds a few more debugging routines
136	  to the cifs code which slightly increases the size of
137	  the cifs module and can cause additional logging of debug
138	  messages in some error paths, slowing performance. This
139	  option can be turned off unless you are debugging
140	  cifs problems.  If unsure, say N.
143	bool "Dump encryption keys for offline decryption (Unsafe)"
144	depends on CIFS_DEBUG
145	help
146	  Enabling this will dump the encryption and decryption keys
147	  used to communicate on an encrypted share connection on the
148	  console. This allows Wireshark to decrypt and dissect
149	  encrypted network captures. Enable this carefully.
150	  If unsure, say N.
153	bool "DFS feature support"
154	depends on CIFS
155	help
156	  Distributed File System (DFS) support is used to access shares
157	  transparently in an enterprise name space, even if the share
158	  moves to a different server.  This feature also enables
159	  an upcall mechanism for CIFS which contacts userspace helper
160	  utilities to provide server name resolution (host names to
161	  IP addresses) which is needed in order to reconnect to
162	  servers if their addresses change or for implicit mounts of
163	  DFS junction points. If unsure, say Y.
166	bool "SWN feature support"
167	depends on CIFS
168	help
169	  The Service Witness Protocol (SWN) is used to get notifications
170	  from a highly available server of resource state changes. This
171	  feature enables an upcall mechanism for CIFS which contacts a
172	  userspace daemon to establish the DCE/RPC connection to retrieve
173	  the cluster available interfaces and resource change notifications.
174	  If unsure, say Y.
177	bool "Allow nfsd to export CIFS file system"
178	depends on CIFS && BROKEN
179	help
180	  Allows NFS server to export a CIFS mounted share (nfsd over cifs)
183	bool "SMB Direct support"
185	help
186	  Enables SMB Direct support for SMB 3.0, 3.02 and 3.1.1.
187	  SMB Direct allows transferring SMB packets over RDMA. If unsure,
188	  say Y.
190config CIFS_FSCACHE
191	bool "Provide CIFS client caching support"
192	depends on CIFS=m && FSCACHE || CIFS=y && FSCACHE=y
193	help
194	  Makes CIFS FS-Cache capable. Say Y here if you want your CIFS data
195	  to be cached locally on disk through the general filesystem cache
196	  manager. If unsure, say N.
198config CIFS_ROOT
199	bool "SMB root file system (Experimental)"
200	depends on CIFS=y && IP_PNP
201	help
202	  Enables root file system support over SMB protocol.
204	  Most people say N here.