fs/cifs/Kconfig

   1 config CIFS
   2         tristate "SMB3 and CIFS support (advanced network filesystem)"
   3         depends on INET
   4         select NLS
   5         select CRYPTO
   6         select CRYPTO_MD4
   7         select CRYPTO_MD5
   8         select CRYPTO_SHA256
   9         select CRYPTO_CMAC
  10         select CRYPTO_HMAC
  11         select CRYPTO_ARC4
  12         select CRYPTO_AEAD2
  13         select CRYPTO_CCM
  14         select CRYPTO_ECB
  15         select CRYPTO_AES
  16         select CRYPTO_DES
  17         help
  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.
  23
  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
  30           provided as well.
  31
  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.
  38
  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.
  45
  46           If you need to mount to Samba, Macs or Windows from this machine, say Y.
  47
  48 config CIFS_STATS
  49         bool "CIFS statistics"
  50         depends on CIFS
  51         help
  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
  54
  55 config CIFS_STATS2
  56         bool "Extended statistics"
  57         depends on CIFS_STATS
  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 fs/cifs/README for more details).
  63           These additional statistics may have a minor effect on performance
  64           and memory utilization.
  65
  66           Unless you are a developer or are doing network performance analysis
  67           or tuning, say N.
  68
  69 config CIFS_WEAK_PW_HASH
  70         bool "Support legacy servers which use weaker LANMAN security"
  71         depends on CIFS
  72         help
  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.
  79
  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
  92           attack.
  93
  94           If unsure, say N.
  95
  96 config CIFS_UPCALL
  97         bool "Kerberos/SPNEGO advanced session setup"
  98         depends on CIFS && KEYS
  99         select DNS_RESOLVER
 100         help
 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.
 105
 106 config CIFS_XATTR
 107         bool "CIFS extended attributes"
 108         depends on CIFS
 109         help
 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.
 118
 119           If unsure, say Y.
 120
 121 config CIFS_POSIX
 122         bool "CIFS POSIX Extensions"
 123         depends on CIFS_XATTR
 124         help
 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.
 132
 133 config CIFS_ACL
 134           bool "Provide CIFS ACL support"
 135           depends on CIFS_XATTR && KEYS
 136           help
 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.
 140
 141 config CIFS_DEBUG
 142         bool "Enable CIFS debugging routines"
 143         default y
 144         depends on CIFS
 145         help
 146            Enabling this option adds helpful debugging messages to
 147            the cifs code which increases the size of the cifs module.
 148            If unsure, say Y.
 149 config CIFS_DEBUG2
 150         bool "Enable additional CIFS debugging routines"
 151         depends on CIFS_DEBUG
 152         help
 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.
 159
 160 config CIFS_DEBUG_DUMP_KEYS
 161         bool "Dump encryption keys for offline decryption (Unsafe)"
 162         depends on CIFS_DEBUG
 163         help
 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.
 168            If unsure, say N.
 169
 170 config CIFS_DFS_UPCALL
 171           bool "DFS feature support"
 172           depends on CIFS && KEYS
 173           select DNS_RESOLVER
 174           help
 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.
 182
 183 config CIFS_NFSD_EXPORT
 184           bool "Allow nfsd to export CIFS file system"
 185           depends on CIFS && BROKEN
 186           help
 187            Allows NFS server to export a CIFS mounted share (nfsd over cifs)
 188
 189 config CIFS_SMB311
 190         bool "SMB3.1.1 network file system support"
 191         depends on CIFS
 192         select CRYPTO_SHA512
 193
 194         help
 195           This enables support for the newest, and most secure dialect, SMB3.11.
 196           If unsure, say Y
 197
 198 config CIFS_SMB_DIRECT
 199         bool "SMB Direct support (Experimental)"
 200         depends on CIFS=m && INFINIBAND && INFINIBAND_ADDR_TRANS || CIFS=y && INFINIBAND=y && INFINIBAND_ADDR_TRANS=y
 201         help
 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,
 204           say N.
 205
 206 config CIFS_FSCACHE
 207           bool "Provide CIFS client caching support"
 208           depends on CIFS=m && FSCACHE || CIFS=y && FSCACHE=y
 209           help
 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.
 213