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1config CIFS
2 tristate "CIFS support (advanced network filesystem, SMBFS successor)"
3 depends on INET
4 select NLS
5 select CRYPTO
6 select CRYPTO_MD4
7 select CRYPTO_MD5
8 select CRYPTO_HMAC
9 select CRYPTO_ARC4
10 select CRYPTO_ECB
11 select CRYPTO_DES
12 help
13 This is the client VFS module for the Common Internet File System
14 (CIFS) protocol which is the successor to the Server Message Block
15 (SMB) protocol, the native file sharing mechanism for most early
16 PC operating systems. The CIFS protocol is fully supported by
17 file servers such as Windows 2000 (including Windows 2003, NT 4
18 and Windows XP) as well by Samba (which provides excellent CIFS
19 server support for Linux and many other operating systems). Limited
20 support for OS/2 and Windows ME and similar servers is provided as
21 well.
22
23 The cifs module provides an advanced network file system
24 client for mounting to CIFS compliant servers. It includes
25 support for DFS (hierarchical name space), secure per-user
26 session establishment via Kerberos or NTLM or NTLMv2,
27 safe distributed caching (oplock), optional packet
28 signing, Unicode and other internationalization improvements.
29 If you need to mount to Samba or Windows from this machine, say Y.
30
31config CIFS_STATS
32 bool "CIFS statistics"
33 depends on CIFS
34 help
35 Enabling this option will cause statistics for each server share
36 mounted by the cifs client to be displayed in /proc/fs/cifs/Stats
37
38config CIFS_STATS2
39 bool "Extended statistics"
40 depends on CIFS_STATS
41 help
42 Enabling this option will allow more detailed statistics on SMB
43 request timing to be displayed in /proc/fs/cifs/DebugData and also
44 allow optional logging of slow responses to dmesg (depending on the
45 value of /proc/fs/cifs/cifsFYI, see fs/cifs/README for more details).
46 These additional statistics may have a minor effect on performance
47 and memory utilization.
48
49 Unless you are a developer or are doing network performance analysis
50 or tuning, say N.
51
52config CIFS_WEAK_PW_HASH
53 bool "Support legacy servers which use weaker LANMAN security"
54 depends on CIFS
55 help
56 Modern CIFS servers including Samba and most Windows versions
57 (since 1997) support stronger NTLM (and even NTLMv2 and Kerberos)
58 security mechanisms. These hash the password more securely
59 than the mechanisms used in the older LANMAN version of the
60 SMB protocol but LANMAN based authentication is needed to
61 establish sessions with some old SMB servers.
62
63 Enabling this option allows the cifs module to mount to older
64 LANMAN based servers such as OS/2 and Windows 95, but such
65 mounts may be less secure than mounts using NTLM or more recent
66 security mechanisms if you are on a public network. Unless you
67 have a need to access old SMB servers (and are on a private
68 network) you probably want to say N. Even if this support
69 is enabled in the kernel build, LANMAN authentication will not be
70 used automatically. At runtime LANMAN mounts are disabled but
71 can be set to required (or optional) either in
72 /proc/fs/cifs (see fs/cifs/README for more detail) or via an
73 option on the mount command. This support is disabled by
74 default in order to reduce the possibility of a downgrade
75 attack.
76
77 If unsure, say N.
78
79config CIFS_UPCALL
80 bool "Kerberos/SPNEGO advanced session setup"
81 depends on CIFS && KEYS
82 select DNS_RESOLVER
83 help
84 Enables an upcall mechanism for CIFS which accesses userspace helper
85 utilities to provide SPNEGO packaged (RFC 4178) Kerberos tickets
86 which are needed to mount to certain secure servers (for which more
87 secure Kerberos authentication is required). If unsure, say N.
88
89config CIFS_XATTR
90 bool "CIFS extended attributes"
91 depends on CIFS
92 help
93 Extended attributes are name:value pairs associated with inodes by
94 the kernel or by users (see the attr(5) manual page, or visit
95 <http://acl.bestbits.at/> for details). CIFS maps the name of
96 extended attributes beginning with the user namespace prefix
97 to SMB/CIFS EAs. EAs are stored on Windows servers without the
98 user namespace prefix, but their names are seen by Linux cifs clients
99 prefaced by the user namespace prefix. The system namespace
100 (used by some filesystems to store ACLs) is not supported at
101 this time.
102
103 If unsure, say N.
104
105config CIFS_POSIX
106 bool "CIFS POSIX Extensions"
107 depends on CIFS_XATTR
108 help
109 Enabling this option will cause the cifs client to attempt to
110 negotiate a newer dialect with servers, such as Samba 3.0.5
111 or later, that optionally can handle more POSIX like (rather
112 than Windows like) file behavior. It also enables
113 support for POSIX ACLs (getfacl and setfacl) to servers
114 (such as Samba 3.10 and later) which can negotiate
115 CIFS POSIX ACL support. If unsure, say N.
116
117config CIFS_DEBUG2
118 bool "Enable additional CIFS debugging routines"
119 depends on CIFS
120 help
121 Enabling this option adds a few more debugging routines
122 to the cifs code which slightly increases the size of
123 the cifs module and can cause additional logging of debug
124 messages in some error paths, slowing performance. This
125 option can be turned off unless you are debugging
126 cifs problems. If unsure, say N.
127
128config CIFS_DFS_UPCALL
129 bool "DFS feature support"
130 depends on CIFS && KEYS
131 select DNS_RESOLVER
132 help
133 Distributed File System (DFS) support is used to access shares
134 transparently in an enterprise name space, even if the share
135 moves to a different server. This feature also enables
136 an upcall mechanism for CIFS which contacts userspace helper
137 utilities to provide server name resolution (host names to
138 IP addresses) which is needed for implicit mounts of DFS junction
139 points. If unsure, say N.
140
141config CIFS_FSCACHE
142 bool "Provide CIFS client caching support"
143 depends on CIFS=m && FSCACHE || CIFS=y && FSCACHE=y
144 help
145 Makes CIFS FS-Cache capable. Say Y here if you want your CIFS data
146 to be cached locally on disk through the general filesystem cache
147 manager. If unsure, say N.
148
149config CIFS_ACL
150 bool "Provide CIFS ACL support"
151 depends on CIFS_XATTR && KEYS
152 help
153 Allows to fetch CIFS/NTFS ACL from the server. The DACL blob
154 is handed over to the application/caller.
155
156config CIFS_NFSD_EXPORT
157 bool "Allow nfsd to export CIFS file system (EXPERIMENTAL)"
158 depends on CIFS && EXPERIMENTAL && BROKEN
159 help
160 Allows NFS server to export a CIFS mounted share (nfsd over cifs)
161
162config CIFS_SMB2
163 bool "SMB2 network file system support (EXPERIMENTAL)"
164 depends on EXPERIMENTAL && INET && BROKEN
165 select NLS
166 select KEYS
167 select FSCACHE
168 select DNS_RESOLVER
169
170 help
171 This enables experimental support for the SMB2 (Server Message Block
172 version 2) protocol. The SMB2 protocol is the successor to the
173 popular CIFS and SMB network file sharing protocols. SMB2 is the
174 native file sharing mechanism for recent versions of Windows
175 operating systems (since Vista). SMB2 enablement will eventually
176 allow users better performance, security and features, than would be
177 possible with cifs. Note that smb2 mount options also are simpler
178 (compared to cifs) due to protocol improvements.
179
180 Unless you are a developer or tester, say N.
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_LIB_ARC4
14 select CRYPTO_AEAD2
15 select CRYPTO_CCM
16 select CRYPTO_GCM
17 select CRYPTO_ECB
18 select CRYPTO_AES
19 select CRYPTO_LIB_DES
20 select KEYS
21 select DNS_RESOLVER
22 select ASN1
23 select OID_REGISTRY
24 help
25 This is the client VFS module for the SMB3 family of NAS protocols,
26 (including support for the most recent, most secure dialect SMB3.1.1)
27 as well as for earlier dialects such as SMB2.1, SMB2 and the older
28 Common Internet File System (CIFS) protocol. CIFS was the successor
29 to the original dialect, the Server Message Block (SMB) protocol, the
30 native file sharing mechanism for most early PC operating systems.
31
32 The SMB3 protocol is supported by most modern operating systems
33 and NAS appliances (e.g. Samba, Windows 10, Windows Server 2016,
34 MacOS) and even in the cloud (e.g. Microsoft Azure).
35 The older CIFS protocol was included in Windows NT4, 2000 and XP (and
36 later) as well by Samba (which provides excellent CIFS and SMB3
37 server support for Linux and many other operating systems). Use of
38 dialects older than SMB2.1 is often discouraged on public networks.
39 This module also provides limited support for OS/2 and Windows ME
40 and similar very old servers.
41
42 This module provides an advanced network file system client
43 for mounting to SMB3 (and CIFS) compliant servers. It includes
44 support for DFS (hierarchical name space), secure per-user
45 session establishment via Kerberos or NTLM or NTLMv2, RDMA
46 (smbdirect), advanced security features, per-share encryption,
47 directory leases, safe distributed caching (oplock), optional packet
48 signing, Unicode and other internationalization improvements.
49
50 In general, the default dialects, SMB3 and later, enable better
51 performance, security and features, than would be possible with CIFS.
52 Note that when mounting to Samba, due to the CIFS POSIX extensions,
53 CIFS mounts can provide slightly better POSIX compatibility
54 than SMB3 mounts. SMB2/SMB3 mount options are also
55 slightly simpler (compared to CIFS) due to protocol improvements.
56
57 If you need to mount to Samba, Azure, Macs or Windows from this machine, say Y.
58
59config CIFS_STATS2
60 bool "Extended statistics"
61 depends on CIFS
62 default y
63 help
64 Enabling this option will allow more detailed statistics on SMB
65 request timing to be displayed in /proc/fs/cifs/DebugData and also
66 allow optional logging of slow responses to dmesg (depending on the
67 value of /proc/fs/cifs/cifsFYI). See Documentation/admin-guide/cifs/usage.rst
68 for more details. These additional statistics may have a minor effect
69 on performance and memory utilization.
70
71 If unsure, say Y.
72
73config CIFS_ALLOW_INSECURE_LEGACY
74 bool "Support legacy servers which use less secure dialects"
75 depends on CIFS
76 default y
77 help
78 Modern dialects, SMB2.1 and later (including SMB3 and 3.1.1), have
79 additional security features, including protection against
80 man-in-the-middle attacks and stronger crypto hashes, so the use
81 of legacy dialects (SMB1/CIFS and SMB2.0) is discouraged.
82
83 Disabling this option prevents users from using vers=1.0 or vers=2.0
84 on mounts with cifs.ko
85
86 If unsure, say Y.
87
88config CIFS_WEAK_PW_HASH
89 bool "Support legacy servers which use weaker LANMAN security"
90 depends on CIFS && CIFS_ALLOW_INSECURE_LEGACY
91 help
92 Modern CIFS servers including Samba and most Windows versions
93 (since 1997) support stronger NTLM (and even NTLMv2 and Kerberos)
94 security mechanisms. These hash the password more securely
95 than the mechanisms used in the older LANMAN version of the
96 SMB protocol but LANMAN based authentication is needed to
97 establish sessions with some old SMB servers.
98
99 Enabling this option allows the cifs module to mount to older
100 LANMAN based servers such as OS/2 and Windows 95, but such
101 mounts may be less secure than mounts using NTLM or more recent
102 security mechanisms if you are on a public network. Unless you
103 have a need to access old SMB servers (and are on a private
104 network) you probably want to say N. Even if this support
105 is enabled in the kernel build, LANMAN authentication will not be
106 used automatically. At runtime LANMAN mounts are disabled but
107 can be set to required (or optional) either in
108 /proc/fs/cifs (see Documentation/admin-guide/cifs/usage.rst for
109 more detail) or via an option on the mount command. This support
110 is disabled by default in order to reduce the possibility of a
111 downgrade attack.
112
113 If unsure, say N.
114
115config CIFS_UPCALL
116 bool "Kerberos/SPNEGO advanced session setup"
117 depends on CIFS
118 help
119 Enables an upcall mechanism for CIFS which accesses userspace helper
120 utilities to provide SPNEGO packaged (RFC 4178) Kerberos tickets
121 which are needed to mount to certain secure servers (for which more
122 secure Kerberos authentication is required). If unsure, say Y.
123
124config CIFS_XATTR
125 bool "CIFS extended attributes"
126 depends on CIFS
127 help
128 Extended attributes are name:value pairs associated with inodes by
129 the kernel or by users (see the attr(5) manual page for details).
130 CIFS maps the name of extended attributes beginning with the user
131 namespace prefix to SMB/CIFS EAs. EAs are stored on Windows
132 servers without the user namespace prefix, but their names are
133 seen by Linux cifs clients prefaced by the user namespace prefix.
134 The system namespace (used by some filesystems to store ACLs) is
135 not supported at this time.
136
137 If unsure, say Y.
138
139config CIFS_POSIX
140 bool "CIFS POSIX Extensions"
141 depends on CIFS && CIFS_ALLOW_INSECURE_LEGACY && CIFS_XATTR
142 help
143 Enabling this option will cause the cifs client to attempt to
144 negotiate a newer dialect with servers, such as Samba 3.0.5
145 or later, that optionally can handle more POSIX like (rather
146 than Windows like) file behavior. It also enables
147 support for POSIX ACLs (getfacl and setfacl) to servers
148 (such as Samba 3.10 and later) which can negotiate
149 CIFS POSIX ACL support. If unsure, say N.
150
151config CIFS_DEBUG
152 bool "Enable CIFS debugging routines"
153 default y
154 depends on CIFS
155 help
156 Enabling this option adds helpful debugging messages to
157 the cifs code which increases the size of the cifs module.
158 If unsure, say Y.
159
160config CIFS_DEBUG2
161 bool "Enable additional CIFS debugging routines"
162 depends on CIFS_DEBUG
163 help
164 Enabling this option adds a few more debugging routines
165 to the cifs code which slightly increases the size of
166 the cifs module and can cause additional logging of debug
167 messages in some error paths, slowing performance. This
168 option can be turned off unless you are debugging
169 cifs problems. If unsure, say N.
170
171config CIFS_DEBUG_DUMP_KEYS
172 bool "Dump encryption keys for offline decryption (Unsafe)"
173 depends on CIFS_DEBUG
174 help
175 Enabling this will dump the encryption and decryption keys
176 used to communicate on an encrypted share connection on the
177 console. This allows Wireshark to decrypt and dissect
178 encrypted network captures. Enable this carefully.
179 If unsure, say N.
180
181config CIFS_DFS_UPCALL
182 bool "DFS feature support"
183 depends on CIFS
184 help
185 Distributed File System (DFS) support is used to access shares
186 transparently in an enterprise name space, even if the share
187 moves to a different server. This feature also enables
188 an upcall mechanism for CIFS which contacts userspace helper
189 utilities to provide server name resolution (host names to
190 IP addresses) which is needed in order to reconnect to
191 servers if their addresses change or for implicit mounts of
192 DFS junction points. If unsure, say Y.
193
194config CIFS_SWN_UPCALL
195 bool "SWN feature support"
196 depends on CIFS
197 help
198 The Service Witness Protocol (SWN) is used to get notifications
199 from a highly available server of resource state changes. This
200 feature enables an upcall mechanism for CIFS which contacts a
201 userspace daemon to establish the DCE/RPC connection to retrieve
202 the cluster available interfaces and resource change notifications.
203 If unsure, say Y.
204
205config CIFS_NFSD_EXPORT
206 bool "Allow nfsd to export CIFS file system"
207 depends on CIFS && BROKEN
208 help
209 Allows NFS server to export a CIFS mounted share (nfsd over cifs)
210
211config CIFS_SMB_DIRECT
212 bool "SMB Direct support"
213 depends on CIFS=m && INFINIBAND && INFINIBAND_ADDR_TRANS || CIFS=y && INFINIBAND=y && INFINIBAND_ADDR_TRANS=y
214 help
215 Enables SMB Direct support for SMB 3.0, 3.02 and 3.1.1.
216 SMB Direct allows transferring SMB packets over RDMA. If unsure,
217 say Y.
218
219config CIFS_FSCACHE
220 bool "Provide CIFS client caching support"
221 depends on CIFS=m && FSCACHE || CIFS=y && FSCACHE=y
222 help
223 Makes CIFS FS-Cache capable. Say Y here if you want your CIFS data
224 to be cached locally on disk through the general filesystem cache
225 manager. If unsure, say N.
226
227config CIFS_ROOT
228 bool "SMB root file system (Experimental)"
229 depends on CIFS=y && IP_PNP
230 help
231 Enables root file system support over SMB protocol.
232
233 Most people say N here.