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 NLS_UCS2_UTILS 7 select CRYPTO 8 select CRYPTO_MD5 9 select CRYPTO_SHA256 10 select CRYPTO_SHA512 11 select CRYPTO_CMAC 12 select CRYPTO_HMAC 13 select CRYPTO_AEAD2 14 select CRYPTO_CCM 15 select CRYPTO_GCM 16 select CRYPTO_ECB 17 select CRYPTO_AES 18 select KEYS 19 select DNS_RESOLVER 20 select ASN1 21 select OID_REGISTRY 22 select NETFS_SUPPORT 23 help 24 This is the client VFS module for the SMB3 family of network file 25 protocols (including the most recent, most secure dialect SMB3.1.1). 26 This module also includes support for earlier dialects such as 27 SMB2.1, SMB2 and even the old Common Internet File System (CIFS) 28 protocol. CIFS was the successor to the original network filesystem 29 protocol, Server Message Block (SMB ie SMB1), the native file sharing 30 mechanism for most early PC operating systems. 31 32 The SMB3.1.1 protocol is supported by most modern operating systems 33 and NAS appliances (e.g. Samba, Windows 11, Windows Server 2022, 34 MacOS) and even in the cloud (e.g. Microsoft Azure) and also by the 35 Linux kernel server, ksmbd. Support for the older CIFS protocol was 36 included in Windows NT4, 2000 and XP (and later). Use of dialects 37 older than SMB2.1 is often discouraged on public networks. 38 This module also provides limited support for OS/2 and Windows ME 39 and similar very old servers. 40 41 This module provides an advanced network file system client for 42 mounting to SMB3 (and CIFS) compliant servers. It includes support 43 for DFS (hierarchical name space), secure per-user session 44 establishment via Kerberos or NTLMv2, RDMA (smbdirect), advanced 45 security features, per-share encryption, packet-signing, snapshots, 46 directory leases, safe distributed caching (leases), multichannel, 47 Unicode and other internationalization improvements. 48 49 In general, the default dialects, SMB3 and later, enable better 50 performance, security and features, than would be possible with CIFS. 51 52 If you need to mount to Samba, Azure, ksmbd, Macs or Windows from this 53 machine, say Y. 54 55config CIFS_STATS2 56 bool "Extended statistics" 57 depends on CIFS 58 default y 59 help 60 Enabling this option will allow more detailed statistics on SMB 61 request timing to be displayed in /proc/fs/cifs/DebugData and also 62 allow optional logging of slow responses to dmesg (depending on the 63 value of /proc/fs/cifs/cifsFYI). See Documentation/admin-guide/cifs/usage.rst 64 for more details. These additional statistics may have a minor effect 65 on performance and memory utilization. 66 67 If unsure, say Y. 68 69config CIFS_ALLOW_INSECURE_LEGACY 70 bool "Support legacy servers which use less secure dialects" 71 depends on CIFS 72 default y 73 help 74 Modern dialects, SMB2.1 and later (including SMB3 and 3.1.1), have 75 additional security features, including protection against 76 man-in-the-middle attacks and stronger crypto hashes, so the use 77 of legacy dialects (SMB1/CIFS and SMB2.0) is discouraged. 78 79 Disabling this option prevents users from using vers=1.0 or vers=2.0 80 on mounts with cifs.ko 81 82 If unsure, say Y. 83 84config CIFS_UPCALL 85 bool "Kerberos/SPNEGO advanced session setup" 86 depends on CIFS 87 help 88 Enables an upcall mechanism for CIFS which accesses userspace helper 89 utilities to provide SPNEGO packaged (RFC 4178) Kerberos tickets 90 which are needed to mount to certain secure servers (for which more 91 secure Kerberos authentication is required). If unsure, say Y. 92 93config CIFS_XATTR 94 bool "CIFS extended attributes" 95 depends on CIFS 96 help 97 Extended attributes are name:value pairs associated with inodes by 98 the kernel or by users (see the attr(5) manual page for details). 99 CIFS maps the name of extended attributes beginning with the user 100 namespace prefix to SMB/CIFS EAs. EAs are stored on Windows 101 servers without the user namespace prefix, but their names are 102 seen by Linux cifs clients prefaced by the user namespace prefix. 103 The system namespace (used by some filesystems to store ACLs) is 104 not supported at this time. 105 106 If unsure, say Y. 107 108config CIFS_POSIX 109 bool "CIFS POSIX Extensions" 110 depends on CIFS && CIFS_ALLOW_INSECURE_LEGACY && CIFS_XATTR 111 help 112 Enabling this option will cause the cifs client to attempt to 113 negotiate a feature of the older cifs dialect with servers, such as 114 Samba 3.0.5 or later, that optionally can handle more POSIX like 115 (rather than Windows like) file behavior. It also enables support 116 for POSIX ACLs (getfacl and setfacl) to servers (such as Samba 3.10 117 and later) which can negotiate CIFS POSIX ACL support. This config 118 option is not needed when mounting with SMB3.1.1. If unsure, say N. 119 120config CIFS_DEBUG 121 bool "Enable CIFS debugging routines" 122 default y 123 depends on CIFS 124 help 125 Enabling this option adds helpful debugging messages to 126 the cifs code which increases the size of the cifs module. 127 If unsure, say Y. 128 129config CIFS_DEBUG2 130 bool "Enable additional CIFS debugging routines" 131 depends on CIFS_DEBUG 132 help 133 Enabling this option adds a few more debugging routines 134 to the cifs code which slightly increases the size of 135 the cifs module and can cause additional logging of debug 136 messages in some error paths, slowing performance. This 137 option can be turned off unless you are debugging 138 cifs problems. If unsure, say N. 139 140config CIFS_DEBUG_DUMP_KEYS 141 bool "Dump encryption keys for offline decryption (Unsafe)" 142 depends on CIFS_DEBUG 143 help 144 Enabling this will dump the encryption and decryption keys 145 used to communicate on an encrypted share connection on the 146 console. This allows Wireshark to decrypt and dissect 147 encrypted network captures. Enable this carefully. 148 If unsure, say N. 149 150config CIFS_DFS_UPCALL 151 bool "DFS feature support" 152 depends on CIFS 153 help 154 Distributed File System (DFS) support is used to access shares 155 transparently in an enterprise name space, even if the share 156 moves to a different server. This feature also enables 157 an upcall mechanism for CIFS which contacts userspace helper 158 utilities to provide server name resolution (host names to 159 IP addresses) which is needed in order to reconnect to 160 servers if their addresses change or for implicit mounts of 161 DFS junction points. If unsure, say Y. 162 163config CIFS_SWN_UPCALL 164 bool "SWN feature support" 165 depends on CIFS 166 help 167 The Service Witness Protocol (SWN) is used to get notifications 168 from a highly available server of resource state changes. This 169 feature enables an upcall mechanism for CIFS which contacts a 170 userspace daemon to establish the DCE/RPC connection to retrieve 171 the cluster available interfaces and resource change notifications. 172 If unsure, say Y. 173 174config CIFS_NFSD_EXPORT 175 bool "Allow nfsd to export CIFS file system" 176 depends on CIFS && BROKEN 177 help 178 Allows NFS server to export a CIFS mounted share (nfsd over cifs) 179 180if CIFS 181 182config CIFS_SMB_DIRECT 183 bool "SMB Direct support" 184 depends on CIFS=m && INFINIBAND && INFINIBAND_ADDR_TRANS || CIFS=y && INFINIBAND=y && INFINIBAND_ADDR_TRANS=y 185 help 186 Enables SMB Direct support for SMB 3.0, 3.02 and 3.1.1. 187 SMB Direct allows transferring SMB packets over RDMA. If unsure, 188 say Y. 189 190config CIFS_FSCACHE 191 bool "Provide CIFS client caching support" 192 depends on CIFS=m && FSCACHE || CIFS=y && FSCACHE=y 193 help 194 Makes CIFS FS-Cache capable. Say Y here if you want your CIFS data 195 to be cached locally on disk through the general filesystem cache 196 manager. If unsure, say N. 197 198config CIFS_ROOT 199 bool "SMB root file system (Experimental)" 200 depends on CIFS=y && IP_PNP 201 help 202 Enables root file system support over SMB protocol. 203 204 Most people say N here. 205 206config CIFS_COMPRESSION 207 bool "SMB message compression (Experimental)" 208 depends on CIFS 209 default n 210 help 211 Enables over-the-wire message compression for SMB 3.1.1 212 mounts when negotiated with the server. 213 214 Only write requests with data size >= PAGE_SIZE will be 215 compressed to avoid wasting resources. 216 217 Say Y here if you want SMB traffic to be compressed. 218 If unsure, say N. 219 220endif 221