2 tristate "SMB3 and CIFS support (advanced network filesystem)"
18 This is the client VFS module for the SMB3 family of NAS protocols,
19 as well as for earlier dialects such as SMB2.1, SMB2 and the
20 Common Internet File System (CIFS) protocol. CIFS was the successor
21 to the original dialect, the Server Message Block (SMB) protocol, the
22 native file sharing mechanism for most early PC operating systems.
24 The SMB3 protocol is supported by most modern operating systems and
25 NAS appliances (e.g. Samba, Windows 8, Windows 2012, MacOS).
26 The older CIFS protocol was included in Windows NT4, 2000 and XP (and
27 later) as well by Samba (which provides excellent CIFS and SMB3
28 server support for Linux and many other operating systems). Limited
29 support for OS/2 and Windows ME and similar very old servers is
32 The cifs module provides an advanced network file system client
33 for mounting to SMB3 (and CIFS) compliant servers. It includes
34 support for DFS (hierarchical name space), secure per-user
35 session establishment via Kerberos or NTLM or NTLMv2,
36 safe distributed caching (oplock), optional packet
37 signing, Unicode and other internationalization improvements.
39 In general, the default dialects, SMB3 and later, enable better
40 performance, security and features, than would be possible with CIFS.
41 Note that when mounting to Samba, due to the CIFS POSIX extensions,
42 CIFS mounts can provide slightly better POSIX compatibility
43 than SMB3 mounts. SMB2/SMB3 mount options are also
44 slightly simpler (compared to CIFS) due to protocol improvements.
46 If you need to mount to Samba, Macs or Windows from this machine, say Y.
49 bool "CIFS statistics"
52 Enabling this option will cause statistics for each server share
53 mounted by the cifs client to be displayed in /proc/fs/cifs/Stats
56 bool "Extended statistics"
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 fs/cifs/README for more details).
63 These additional statistics may have a minor effect on performance
64 and memory utilization.
66 Unless you are a developer or are doing network performance analysis
69 config CIFS_WEAK_PW_HASH
70 bool "Support legacy servers which use weaker LANMAN security"
73 Modern CIFS servers including Samba and most Windows versions
74 (since 1997) support stronger NTLM (and even NTLMv2 and Kerberos)
75 security mechanisms. These hash the password more securely
76 than the mechanisms used in the older LANMAN version of the
77 SMB protocol but LANMAN based authentication is needed to
78 establish sessions with some old SMB servers.
80 Enabling this option allows the cifs module to mount to older
81 LANMAN based servers such as OS/2 and Windows 95, but such
82 mounts may be less secure than mounts using NTLM or more recent
83 security mechanisms if you are on a public network. Unless you
84 have a need to access old SMB servers (and are on a private
85 network) you probably want to say N. Even if this support
86 is enabled in the kernel build, LANMAN authentication will not be
87 used automatically. At runtime LANMAN mounts are disabled but
88 can be set to required (or optional) either in
89 /proc/fs/cifs (see fs/cifs/README for more detail) or via an
90 option on the mount command. This support is disabled by
91 default in order to reduce the possibility of a downgrade
97 bool "Kerberos/SPNEGO advanced session setup"
98 depends on CIFS && KEYS
101 Enables an upcall mechanism for CIFS which accesses userspace helper
102 utilities to provide SPNEGO packaged (RFC 4178) Kerberos tickets
103 which are needed to mount to certain secure servers (for which more
104 secure Kerberos authentication is required). If unsure, say Y.
107 bool "CIFS extended attributes"
110 Extended attributes are name:value pairs associated with inodes by
111 the kernel or by users (see the attr(5) manual page for details).
112 CIFS maps the name of extended attributes beginning with the user
113 namespace prefix to SMB/CIFS EAs. EAs are stored on Windows
114 servers without the user namespace prefix, but their names are
115 seen by Linux cifs clients prefaced by the user namespace prefix.
116 The system namespace (used by some filesystems to store ACLs) is
117 not supported at this time.
122 bool "CIFS POSIX Extensions"
123 depends on CIFS_XATTR
125 Enabling this option will cause the cifs client to attempt to
126 negotiate a newer dialect with servers, such as Samba 3.0.5
127 or later, that optionally can handle more POSIX like (rather
128 than Windows like) file behavior. It also enables
129 support for POSIX ACLs (getfacl and setfacl) to servers
130 (such as Samba 3.10 and later) which can negotiate
131 CIFS POSIX ACL support. If unsure, say N.
134 bool "Provide CIFS ACL support"
135 depends on CIFS_XATTR && KEYS
137 Allows fetching CIFS/NTFS ACL from the server. The DACL blob
138 is handed over to the application/caller. See the man
139 page for getcifsacl for more information. If unsure, say Y.
142 bool "Enable CIFS debugging routines"
146 Enabling this option adds helpful debugging messages to
147 the cifs code which increases the size of the cifs module.
150 bool "Enable additional CIFS debugging routines"
151 depends on CIFS_DEBUG
153 Enabling this option adds a few more debugging routines
154 to the cifs code which slightly increases the size of
155 the cifs module and can cause additional logging of debug
156 messages in some error paths, slowing performance. This
157 option can be turned off unless you are debugging
158 cifs problems. If unsure, say N.
160 config CIFS_DEBUG_DUMP_KEYS
161 bool "Dump encryption keys for offline decryption (Unsafe)"
162 depends on CIFS_DEBUG
164 Enabling this will dump the encryption and decryption keys
165 used to communicate on an encrypted share connection on the
166 console. This allows Wireshark to decrypt and dissect
167 encrypted network captures. Enable this carefully.
170 config CIFS_DFS_UPCALL
171 bool "DFS feature support"
172 depends on CIFS && KEYS
175 Distributed File System (DFS) support is used to access shares
176 transparently in an enterprise name space, even if the share
177 moves to a different server. This feature also enables
178 an upcall mechanism for CIFS which contacts userspace helper
179 utilities to provide server name resolution (host names to
180 IP addresses) which is needed for implicit mounts of DFS junction
181 points. If unsure, say Y.
183 config CIFS_NFSD_EXPORT
184 bool "Allow nfsd to export CIFS file system"
185 depends on CIFS && BROKEN
187 Allows NFS server to export a CIFS mounted share (nfsd over cifs)
190 bool "SMB3.1.1 network file system support (Experimental)"
194 This enables experimental support for the newest, SMB3.1.1, dialect.
195 This dialect includes improved security negotiation features.
198 config CIFS_SMB_DIRECT
199 bool "SMB Direct support (Experimental)"
200 depends on CIFS=m && INFINIBAND || CIFS=y && INFINIBAND=y
202 Enables SMB Direct experimental support for SMB 3.0, 3.02 and 3.1.1.
203 SMB Direct allows transferring SMB packets over RDMA. If unsure,
207 bool "Provide CIFS client caching support"
208 depends on CIFS=m && FSCACHE || CIFS=y && FSCACHE=y
210 Makes CIFS FS-Cache capable. Say Y here if you want your CIFS data
211 to be cached locally on disk through the general filesystem cache
212 manager. If unsure, say N.