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 select CRYPTO_SHA256 13 select CRYPTO_CMAC 14 help 15 This is the client VFS module for the Common Internet File System 16 (CIFS) protocol which is the successor to the Server Message Block 17 (SMB) protocol, the native file sharing mechanism for most early 18 PC operating systems. The CIFS protocol is fully supported by 19 file servers such as Windows 2000 (including Windows 2003, Windows 2008, 20 NT 4 and Windows XP) as well by Samba (which provides excellent CIFS 21 server support for Linux and many other operating systems). Limited 22 support for OS/2 and Windows ME and similar servers is provided as 23 well. 24 25 The module also provides optional support for the followon 26 protocols for CIFS including SMB3, which enables 27 useful performance and security features (see the description 28 of CONFIG_CIFS_SMB2). 29 30 The cifs module provides an advanced network file system 31 client for mounting to CIFS compliant servers. It includes 32 support for DFS (hierarchical name space), secure per-user 33 session establishment via Kerberos or NTLM or NTLMv2, 34 safe distributed caching (oplock), optional packet 35 signing, Unicode and other internationalization improvements. 36 If you need to mount to Samba or Windows from this machine, say Y. 37 38config CIFS_STATS 39 bool "CIFS statistics" 40 depends on CIFS 41 help 42 Enabling this option will cause statistics for each server share 43 mounted by the cifs client to be displayed in /proc/fs/cifs/Stats 44 45config CIFS_STATS2 46 bool "Extended statistics" 47 depends on CIFS_STATS 48 help 49 Enabling this option will allow more detailed statistics on SMB 50 request timing to be displayed in /proc/fs/cifs/DebugData and also 51 allow optional logging of slow responses to dmesg (depending on the 52 value of /proc/fs/cifs/cifsFYI, see fs/cifs/README for more details). 53 These additional statistics may have a minor effect on performance 54 and memory utilization. 55 56 Unless you are a developer or are doing network performance analysis 57 or tuning, say N. 58 59config CIFS_WEAK_PW_HASH 60 bool "Support legacy servers which use weaker LANMAN security" 61 depends on CIFS 62 help 63 Modern CIFS servers including Samba and most Windows versions 64 (since 1997) support stronger NTLM (and even NTLMv2 and Kerberos) 65 security mechanisms. These hash the password more securely 66 than the mechanisms used in the older LANMAN version of the 67 SMB protocol but LANMAN based authentication is needed to 68 establish sessions with some old SMB servers. 69 70 Enabling this option allows the cifs module to mount to older 71 LANMAN based servers such as OS/2 and Windows 95, but such 72 mounts may be less secure than mounts using NTLM or more recent 73 security mechanisms if you are on a public network. Unless you 74 have a need to access old SMB servers (and are on a private 75 network) you probably want to say N. Even if this support 76 is enabled in the kernel build, LANMAN authentication will not be 77 used automatically. At runtime LANMAN mounts are disabled but 78 can be set to required (or optional) either in 79 /proc/fs/cifs (see fs/cifs/README for more detail) or via an 80 option on the mount command. This support is disabled by 81 default in order to reduce the possibility of a downgrade 82 attack. 83 84 If unsure, say N. 85 86config CIFS_UPCALL 87 bool "Kerberos/SPNEGO advanced session setup" 88 depends on CIFS && KEYS 89 select DNS_RESOLVER 90 help 91 Enables an upcall mechanism for CIFS which accesses userspace helper 92 utilities to provide SPNEGO packaged (RFC 4178) Kerberos tickets 93 which are needed to mount to certain secure servers (for which more 94 secure Kerberos authentication is required). If unsure, say N. 95 96config CIFS_XATTR 97 bool "CIFS extended attributes" 98 depends on CIFS 99 help 100 Extended attributes are name:value pairs associated with inodes by 101 the kernel or by users (see the attr(5) manual page, or visit 102 <http://acl.bestbits.at/> for details). CIFS maps the name of 103 extended attributes beginning with the user namespace prefix 104 to SMB/CIFS EAs. EAs are stored on Windows servers without the 105 user namespace prefix, but their names are seen by Linux cifs clients 106 prefaced by the user namespace prefix. The system namespace 107 (used by some filesystems to store ACLs) is not supported at 108 this time. 109 110 If unsure, say N. 111 112config CIFS_POSIX 113 bool "CIFS POSIX Extensions" 114 depends on CIFS_XATTR 115 help 116 Enabling this option will cause the cifs client to attempt to 117 negotiate a newer dialect with servers, such as Samba 3.0.5 118 or later, that optionally can handle more POSIX like (rather 119 than Windows like) file behavior. It also enables 120 support for POSIX ACLs (getfacl and setfacl) to servers 121 (such as Samba 3.10 and later) which can negotiate 122 CIFS POSIX ACL support. If unsure, say N. 123 124config CIFS_ACL 125 bool "Provide CIFS ACL support" 126 depends on CIFS_XATTR && KEYS 127 help 128 Allows fetching CIFS/NTFS ACL from the server. The DACL blob 129 is handed over to the application/caller. See the man 130 page for getcifsacl for more information. 131 132config CIFS_DEBUG 133 bool "Enable CIFS debugging routines" 134 default y 135 depends on CIFS 136 help 137 Enabling this option adds helpful debugging messages to 138 the cifs code which increases the size of the cifs module. 139 If unsure, say Y. 140config CIFS_DEBUG2 141 bool "Enable additional CIFS debugging routines" 142 depends on CIFS_DEBUG 143 help 144 Enabling this option adds a few more debugging routines 145 to the cifs code which slightly increases the size of 146 the cifs module and can cause additional logging of debug 147 messages in some error paths, slowing performance. This 148 option can be turned off unless you are debugging 149 cifs problems. If unsure, say N. 150 151config CIFS_DFS_UPCALL 152 bool "DFS feature support" 153 depends on CIFS && KEYS 154 select DNS_RESOLVER 155 help 156 Distributed File System (DFS) support is used to access shares 157 transparently in an enterprise name space, even if the share 158 moves to a different server. This feature also enables 159 an upcall mechanism for CIFS which contacts userspace helper 160 utilities to provide server name resolution (host names to 161 IP addresses) which is needed for implicit mounts of DFS junction 162 points. If unsure, say N. 163 164config CIFS_NFSD_EXPORT 165 bool "Allow nfsd to export CIFS file system" 166 depends on CIFS && BROKEN 167 help 168 Allows NFS server to export a CIFS mounted share (nfsd over cifs) 169 170config CIFS_SMB2 171 bool "SMB2 and SMB3 network file system support" 172 depends on CIFS && INET 173 select NLS 174 select KEYS 175 select FSCACHE 176 select DNS_RESOLVER 177 178 help 179 This enables support for the Server Message Block version 2 180 family of protocols, including SMB3. SMB3 support is 181 enabled on mount by specifying "vers=3.0" in the mount 182 options. These protocols are the successors to the popular 183 CIFS and SMB network file sharing protocols. SMB3 is the 184 native file sharing mechanism for the more recent 185 versions of Windows (Windows 8 and Windows 2012 and 186 later) and Samba server and many others support SMB3 well. 187 In general SMB3 enables better performance, security 188 and features, than would be possible with CIFS (Note that 189 when mounting to Samba, due to the CIFS POSIX extensions, 190 CIFS mounts can provide slightly better POSIX compatibility 191 than SMB3 mounts do though). Note that SMB2/SMB3 mount 192 options are also slightly simpler (compared to CIFS) due 193 to protocol improvements. 194 195config CIFS_FSCACHE 196 bool "Provide CIFS client caching support" 197 depends on CIFS=m && FSCACHE || CIFS=y && FSCACHE=y 198 help 199 Makes CIFS FS-Cache capable. Say Y here if you want your CIFS data 200 to be cached locally on disk through the general filesystem cache 201 manager. If unsure, say N. 202 203