xref: /linux/fs/smb/client/Kconfig (revision baa172c77ac52b2058ba3abae7512b7b16d0c461)
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 NLS_UCS2_UTILS
7	select CRYPTO
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	select NETFS_SUPPORT
23	help
24	  This is the client VFS module for the SMB3 family of network file
25	  protocols (including the most recent, most secure dialect SMB3.1.1).
26	  This module also includes support for earlier dialects such as
27	  SMB2.1, SMB2 and even the old Common Internet File System (CIFS)
28	  protocol.  CIFS was the successor to the original network filesystem
29	  protocol, Server Message Block (SMB ie SMB1), the native file sharing
30	  mechanism for most early PC operating systems.
31
32	  The SMB3.1.1 protocol is supported by most modern operating systems
33	  and NAS appliances (e.g. Samba, Windows 11, Windows Server 2022,
34	  MacOS) and even in the cloud (e.g. Microsoft Azure) and also by the
35	  Linux kernel server, ksmbd.  Support for the older CIFS protocol was
36	  included in Windows NT4, 2000 and XP (and later). Use of dialects
37	  older than SMB2.1 is often discouraged on public networks.
38	  This module also provides limited support for OS/2 and Windows ME
39	  and similar very old servers.
40
41	  This module provides an advanced network file system client for
42	  mounting to SMB3 (and CIFS) compliant servers.  It includes support
43	  for DFS (hierarchical name space), secure per-user session
44	  establishment via Kerberos or NTLMv2, RDMA (smbdirect), advanced
45	  security features, per-share encryption, packet-signing, snapshots,
46	  directory leases, safe distributed caching (leases), multichannel,
47	  Unicode and other internationalization improvements.
48
49	  In general, the default dialects, SMB3 and later, enable better
50	  performance, security and features, than would be possible with CIFS.
51
52	  If you need to mount to Samba, Azure, ksmbd, Macs or Windows from this
53	  machine, say Y.
54
55config CIFS_STATS2
56	bool "Extended statistics"
57	depends on CIFS
58	default y
59	help
60	  Enabling this option will allow more detailed statistics on SMB
61	  request timing to be displayed in /proc/fs/cifs/DebugData and also
62	  allow optional logging of slow responses to dmesg (depending on the
63	  value of /proc/fs/cifs/cifsFYI). See Documentation/admin-guide/cifs/usage.rst
64	  for more details. These additional statistics may have a minor effect
65	  on performance and memory utilization.
66
67	  If unsure, say Y.
68
69config CIFS_ALLOW_INSECURE_LEGACY
70	bool "Support legacy servers which use less secure dialects"
71	depends on CIFS
72	default y
73	help
74	  Modern dialects, SMB2.1 and later (including SMB3 and 3.1.1), have
75	  additional security features, including protection against
76	  man-in-the-middle attacks and stronger crypto hashes, so the use
77	  of legacy dialects (SMB1/CIFS and SMB2.0) is discouraged.
78
79	  Disabling this option prevents users from using vers=1.0 or vers=2.0
80	  on mounts with cifs.ko
81
82	  If unsure, say Y.
83
84config CIFS_UPCALL
85	bool "Kerberos/SPNEGO advanced session setup"
86	depends on CIFS
87	help
88	  Enables an upcall mechanism for CIFS which accesses userspace helper
89	  utilities to provide SPNEGO packaged (RFC 4178) Kerberos tickets
90	  which are needed to mount to certain secure servers (for which more
91	  secure Kerberos authentication is required). If unsure, say Y.
92
93config CIFS_XATTR
94	bool "CIFS extended attributes"
95	depends on CIFS
96	help
97	  Extended attributes are name:value pairs associated with inodes by
98	  the kernel or by users (see the attr(5) manual page for details).
99	  CIFS maps the name of extended attributes beginning with the user
100	  namespace prefix to SMB/CIFS EAs.  EAs are stored on Windows
101	  servers without the user namespace prefix, but their names are
102	  seen by Linux cifs clients prefaced by the user namespace prefix.
103	  The system namespace (used by some filesystems to store ACLs) is
104	  not supported at this time.
105
106	  If unsure, say Y.
107
108config CIFS_POSIX
109	bool "CIFS POSIX Extensions"
110	depends on CIFS && CIFS_ALLOW_INSECURE_LEGACY && CIFS_XATTR
111	help
112	  Enabling this option will cause the cifs client to attempt to
113	  negotiate a feature of the older cifs dialect with servers, such as
114	  Samba 3.0.5 or later, that optionally can handle more POSIX like
115	  (rather than Windows like) file behavior.  It also enables support
116	  for POSIX ACLs (getfacl and setfacl) to servers (such as Samba 3.10
117	  and later) which can negotiate CIFS POSIX ACL support.  This config
118	  option is not needed when mounting with SMB3.1.1. If unsure, say N.
119
120config CIFS_DEBUG
121	bool "Enable CIFS debugging routines"
122	default y
123	depends on CIFS
124	help
125	  Enabling this option adds helpful debugging messages to
126	  the cifs code which increases the size of the cifs module.
127	  If unsure, say Y.
128
129config CIFS_DEBUG2
130	bool "Enable additional CIFS debugging routines"
131	depends on CIFS_DEBUG
132	help
133	  Enabling this option adds a few more debugging routines
134	  to the cifs code which slightly increases the size of
135	  the cifs module and can cause additional logging of debug
136	  messages in some error paths, slowing performance. This
137	  option can be turned off unless you are debugging
138	  cifs problems.  If unsure, say N.
139
140config CIFS_DEBUG_DUMP_KEYS
141	bool "Dump encryption keys for offline decryption (Unsafe)"
142	depends on CIFS_DEBUG
143	help
144	  Enabling this will dump the encryption and decryption keys
145	  used to communicate on an encrypted share connection on the
146	  console. This allows Wireshark to decrypt and dissect
147	  encrypted network captures. Enable this carefully.
148	  If unsure, say N.
149
150config CIFS_DFS_UPCALL
151	bool "DFS feature support"
152	depends on CIFS
153	help
154	  Distributed File System (DFS) support is used to access shares
155	  transparently in an enterprise name space, even if the share
156	  moves to a different server.  This feature also enables
157	  an upcall mechanism for CIFS which contacts userspace helper
158	  utilities to provide server name resolution (host names to
159	  IP addresses) which is needed in order to reconnect to
160	  servers if their addresses change or for implicit mounts of
161	  DFS junction points. If unsure, say Y.
162
163config CIFS_SWN_UPCALL
164	bool "SWN feature support"
165	depends on CIFS
166	help
167	  The Service Witness Protocol (SWN) is used to get notifications
168	  from a highly available server of resource state changes. This
169	  feature enables an upcall mechanism for CIFS which contacts a
170	  userspace daemon to establish the DCE/RPC connection to retrieve
171	  the cluster available interfaces and resource change notifications.
172	  If unsure, say Y.
173
174config CIFS_NFSD_EXPORT
175	bool "Allow nfsd to export CIFS file system"
176	depends on CIFS && BROKEN
177	help
178	  Allows NFS server to export a CIFS mounted share (nfsd over cifs)
179
180if CIFS
181
182config CIFS_SMB_DIRECT
183	bool "SMB Direct support"
184	depends on CIFS=m && INFINIBAND && INFINIBAND_ADDR_TRANS || CIFS=y && INFINIBAND=y && INFINIBAND_ADDR_TRANS=y
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.
189
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.
197
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.
203
204	  Most people say N here.
205
206config CIFS_COMPRESSION
207	bool "SMB message compression (Experimental)"
208	depends on CIFS
209	default n
210	help
211	  Enables over-the-wire message compression for SMB 3.1.1
212	  mounts when negotiated with the server.
213
214	  Only write requests with data size >= PAGE_SIZE will be
215	  compressed to avoid wasting resources.
216
217	  Say Y here if you want SMB traffic to be compressed.
218	  If unsure, say N.
219
220endif
221