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_MD5
8	select CRYPTO_SHA256
9	select CRYPTO_SHA512
10	select CRYPTO_CMAC
11	select CRYPTO_HMAC
12	select CRYPTO_AEAD2
13	select CRYPTO_CCM
14	select CRYPTO_GCM
15	select CRYPTO_ECB
16	select CRYPTO_AES
17	select KEYS
18	select DNS_RESOLVER
19	select ASN1
20	select OID_REGISTRY
21	select NETFS_SUPPORT
22	help
23	  This is the client VFS module for the SMB3 family of network file
24	  protocols (including the most recent, most secure dialect SMB3.1.1).
25	  This module also includes support for earlier dialects such as
26	  SMB2.1, SMB2 and even the old Common Internet File System (CIFS)
27	  protocol.  CIFS was the successor to the original network filesystem
28	  protocol, Server Message Block (SMB ie SMB1), the native file sharing
29	  mechanism for most early PC operating systems.
30
31	  The SMB3.1.1 protocol is supported by most modern operating systems
32	  and NAS appliances (e.g. Samba, Windows 11, Windows Server 2022,
33	  MacOS) and even in the cloud (e.g. Microsoft Azure) and also by the
34	  Linux kernel server, ksmbd.  Support for the older CIFS protocol was
35	  included in Windows NT4, 2000 and XP (and later). Use of dialects
36	  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.
39
40	  This module provides an advanced network file system client for
41	  mounting to SMB3 (and CIFS) compliant servers.  It includes support
42	  for DFS (hierarchical name space), secure per-user session
43	  establishment via Kerberos or NTLMv2, RDMA (smbdirect), advanced
44	  security features, per-share encryption, packet-signing, snapshots,
45	  directory leases, safe distributed caching (leases), multichannel,
46	  Unicode and other internationalization improvements.
47
48	  In general, the default dialects, SMB3 and later, enable better
49	  performance, security and features, than would be possible with CIFS.
50
51	  If you need to mount to Samba, Azure, ksmbd, Macs or Windows from this
52	  machine, say Y.
53
54config CIFS_STATS2
55	bool "Extended statistics"
56	depends on CIFS
57	default y
58	help
59	  Enabling this option will allow more detailed statistics on SMB
60	  request timing to be displayed in /proc/fs/cifs/DebugData and also
61	  allow optional logging of slow responses to dmesg (depending on the
62	  value of /proc/fs/cifs/cifsFYI). See Documentation/admin-guide/cifs/usage.rst
63	  for more details. These additional statistics may have a minor effect
64	  on performance and memory utilization.
65
66	  If unsure, say Y.
67
68config CIFS_ALLOW_INSECURE_LEGACY
69	bool "Support legacy servers which use less secure dialects"
70	depends on CIFS
71	default y
72	help
73	  Modern dialects, SMB2.1 and later (including SMB3 and 3.1.1), have
74	  additional security features, including protection against
75	  man-in-the-middle attacks and stronger crypto hashes, so the use
76	  of legacy dialects (SMB1/CIFS and SMB2.0) is discouraged.
77
78	  Disabling this option prevents users from using vers=1.0 or vers=2.0
79	  on mounts with cifs.ko
80
81	  If unsure, say Y.
82
83config CIFS_UPCALL
84	bool "Kerberos/SPNEGO advanced session setup"
85	depends on CIFS
86	help
87	  Enables an upcall mechanism for CIFS which accesses userspace helper
88	  utilities to provide SPNEGO packaged (RFC 4178) Kerberos tickets
89	  which are needed to mount to certain secure servers (for which more
90	  secure Kerberos authentication is required). If unsure, say Y.
91
92config CIFS_XATTR
93	bool "CIFS extended attributes"
94	depends on CIFS
95	help
96	  Extended attributes are name:value pairs associated with inodes by
97	  the kernel or by users (see the attr(5) manual page for details).
98	  CIFS maps the name of extended attributes beginning with the user
99	  namespace prefix to SMB/CIFS EAs.  EAs are stored on Windows
100	  servers without the user namespace prefix, but their names are
101	  seen by Linux cifs clients prefaced by the user namespace prefix.
102	  The system namespace (used by some filesystems to store ACLs) is
103	  not supported at this time.
104
105	  If unsure, say Y.
106
107config CIFS_POSIX
108	bool "CIFS POSIX Extensions"
109	depends on CIFS && CIFS_ALLOW_INSECURE_LEGACY && CIFS_XATTR
110	help
111	  Enabling this option will cause the cifs client to attempt to
112	  negotiate a feature of the older cifs dialect with servers, such as
113	  Samba 3.0.5 or later, that optionally can handle more POSIX like
114	  (rather than Windows like) file behavior.  It also enables support
115	  for POSIX ACLs (getfacl and setfacl) to servers (such as Samba 3.10
116	  and later) which can negotiate CIFS POSIX ACL support.  This config
117	  option is not needed when mounting with SMB3.1.1. If unsure, say N.
118
119config CIFS_DEBUG
120	bool "Enable CIFS debugging routines"
121	default y
122	depends on CIFS
123	help
124	  Enabling this option adds helpful debugging messages to
125	  the cifs code which increases the size of the cifs module.
126	  If unsure, say Y.
127
128config CIFS_DEBUG2
129	bool "Enable additional CIFS debugging routines"
130	depends on CIFS_DEBUG
131	help
132	  Enabling this option adds a few more debugging routines
133	  to the cifs code which slightly increases the size of
134	  the cifs module and can cause additional logging of debug
135	  messages in some error paths, slowing performance. This
136	  option can be turned off unless you are debugging
137	  cifs problems.  If unsure, say N.
138
139config CIFS_DEBUG_DUMP_KEYS
140	bool "Dump encryption keys for offline decryption (Unsafe)"
141	depends on CIFS_DEBUG
142	help
143	  Enabling this will dump the encryption and decryption keys
144	  used to communicate on an encrypted share connection on the
145	  console. This allows Wireshark to decrypt and dissect
146	  encrypted network captures. Enable this carefully.
147	  If unsure, say N.
148
149config CIFS_DFS_UPCALL
150	bool "DFS feature support"
151	depends on CIFS
152	help
153	  Distributed File System (DFS) support is used to access shares
154	  transparently in an enterprise name space, even if the share
155	  moves to a different server.  This feature also enables
156	  an upcall mechanism for CIFS which contacts userspace helper
157	  utilities to provide server name resolution (host names to
158	  IP addresses) which is needed in order to reconnect to
159	  servers if their addresses change or for implicit mounts of
160	  DFS junction points. If unsure, say Y.
161
162config CIFS_SWN_UPCALL
163	bool "SWN feature support"
164	depends on CIFS
165	help
166	  The Service Witness Protocol (SWN) is used to get notifications
167	  from a highly available server of resource state changes. This
168	  feature enables an upcall mechanism for CIFS which contacts a
169	  userspace daemon to establish the DCE/RPC connection to retrieve
170	  the cluster available interfaces and resource change notifications.
171	  If unsure, say Y.
172
173config CIFS_NFSD_EXPORT
174	bool "Allow nfsd to export CIFS file system"
175	depends on CIFS && BROKEN
176	help
177	  Allows NFS server to export a CIFS mounted share (nfsd over cifs)
178
179if CIFS
180
181config CIFS_SMB_DIRECT
182	bool "SMB Direct support"
183	depends on CIFS=m && INFINIBAND && INFINIBAND_ADDR_TRANS || CIFS=y && INFINIBAND=y && INFINIBAND_ADDR_TRANS=y
184	help
185	  Enables SMB Direct support for SMB 3.0, 3.02 and 3.1.1.
186	  SMB Direct allows transferring SMB packets over RDMA. If unsure,
187	  say Y.
188
189config CIFS_FSCACHE
190	bool "Provide CIFS client caching support"
191	depends on CIFS=m && FSCACHE || CIFS=y && FSCACHE=y
192	help
193	  Makes CIFS FS-Cache capable. Say Y here if you want your CIFS data
194	  to be cached locally on disk through the general filesystem cache
195	  manager. If unsure, say N.
196
197config CIFS_ROOT
198	bool "SMB root file system (Experimental)"
199	depends on CIFS=y && IP_PNP
200	help
201	  Enables root file system support over SMB protocol.
202
203	  Most people say N here.
204
205endif
206