linux/fs/smb/client/Kconfig

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# SPDX-License-Identifier: GPL-2.0-only
config CIFS
tristate "SMB3 and CIFS support (advanced network filesystem)"
depends on INET
cifs: Implement netfslib hooks Provide implementation of the netfslib hooks that will be used by netfslib to ask cifs to set up and perform operations. Of particular note are (*) cifs_clamp_length() - This is used to negotiate the size of the next subrequest in a read request, taking into account the credit available and the rsize. The credits are attached to the subrequest. (*) cifs_req_issue_read() - This is used to issue a subrequest that has been set up and clamped. (*) cifs_prepare_write() - This prepares to fill a subrequest by picking a channel, reopening the file and requesting credits so that we can set the maximum size of the subrequest and also sets the maximum number of segments if we're doing RDMA. (*) cifs_issue_write() - This releases any unneeded credits and issues an asynchronous data write for the contiguous slice of file covered by the subrequest. This should possibly be folded in to all ->async_writev() ops and that called directly. (*) cifs_begin_writeback() - This gets the cached writable handle through which we do writeback (this does not affect writethrough, unbuffered or direct writes). At this point, cifs is not wired up to actually *use* netfslib; that will be done in a subsequent patch. Signed-off-by: David Howells <dhowells@redhat.com> cc: Steve French <sfrench@samba.org> cc: Shyam Prasad N <nspmangalore@gmail.com> cc: Rohith Surabattula <rohiths.msft@gmail.com> cc: Jeff Layton <jlayton@kernel.org> cc: linux-cifs@vger.kernel.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org
2023-10-06 17:16:15 +00:00
select NETFS_SUPPORT
select NLS
select NLS_UCS2_UTILS
NTLM auth and sign - Define crypto hash functions and create and send keys needed for key exchange Mark dependency on crypto modules in Kconfig. Defining per structures sdesc and cifs_secmech which are used to store crypto hash functions and contexts. They are stored per smb connection and used for all auth mechs to genereate hash values and signatures. Allocate crypto hashing functions, security descriptiors, and respective contexts when a smb/tcp connection is established. Release them when a tcp/smb connection is taken down. md5 and hmac-md5 are two crypto hashing functions that are used throught the life of an smb/tcp connection by various functions that calcualte signagure and ntlmv2 hash, HMAC etc. structure ntlmssp_auth is defined as per smb connection. ntlmssp_auth holds ciphertext which is genereated by rc4/arc4 encryption of secondary key, a nonce using ntlmv2 session key and sent in the session key field of the type 3 message sent by the client during ntlmssp negotiation/exchange A key is exchanged with the server if client indicates so in flags in type 1 messsage and server agrees in flag in type 2 message of ntlmssp negotiation. If both client and agree, a key sent by client in type 3 message of ntlmssp negotiation in the session key field. The key is a ciphertext generated off of secondary key, a nonce, using ntlmv2 hash via rc4/arc4. Signing works for ntlmssp in this patch. The sequence number within the server structure needs to be zero until session is established i.e. till type 3 packet of ntlmssp exchange of a to be very first smb session on that smb connection is sent. Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-10-21 19:25:08 +00:00
select CRYPTO
select CRYPTO_MD5
select CRYPTO_SHA256
select CRYPTO_SHA512
select CRYPTO_CMAC
select CRYPTO_HMAC
select CRYPTO_AEAD2
select CRYPTO_CCM
select CRYPTO_GCM
select CRYPTO_ECB
select CRYPTO_AES
select KEYS
select DNS_RESOLVER
select ASN1
select OID_REGISTRY
cifs: Change the I/O paths to use an iterator rather than a page list Currently, the cifs I/O paths hand lists of pages from the VM interface routines at the top all the way through the intervening layers to the socket interface at the bottom. This is a problem, however, for interfacing with netfslib which passes an iterator through to the ->issue_read() method (and will pass an iterator through to the ->issue_write() method in future). Netfslib takes over bounce buffering for direct I/O, async I/O and encrypted content, so cifs doesn't need to do that. Netfslib also converts IOVEC-type iterators into BVEC-type iterators if necessary. Further, cifs needs foliating - and folios may come in a variety of sizes, so a page list pointing to an array of heterogeneous pages may cause problems in places such as where crypto is done. Change the cifs I/O paths to hand iov_iter iterators all the way through instead. Notes: (1) Some old routines are #if'd out to be removed in a follow up patch so as to avoid confusing diff, thereby making the diff output easier to follow. I've removed functions that don't overlap with anything added. (2) struct smb_rqst loses rq_pages, rq_offset, rq_npages, rq_pagesz and rq_tailsz which describe the pages forming the buffer; instead there's an rq_iter describing the source buffer and an rq_buffer which is used to hold the buffer for encryption. (3) struct cifs_readdata and cifs_writedata are similarly modified to smb_rqst. The ->read_into_pages() and ->copy_into_pages() are then replaced with passing the iterator directly to the socket. The iterators are stored in these structs so that they are persistent and don't get deallocated when the function returns (unlike if they were stack variables). (4) Buffered writeback is overhauled, borrowing the code from the afs filesystem to gather up contiguous runs of folios. The XARRAY-type iterator is then used to refer directly to the pagecache and can be passed to the socket to transmit data directly from there. This includes: cifs_extend_writeback() cifs_write_back_from_locked_folio() cifs_writepages_region() cifs_writepages() (5) Pages are converted to folios. (6) Direct I/O uses netfs_extract_user_iter() to create a BVEC-type iterator from an IOBUF/UBUF-type source iterator. (7) smb2_get_aead_req() uses netfs_extract_iter_to_sg() to extract page fragments from the iterator into the scatterlists that the crypto layer prefers. (8) smb2_init_transform_rq() attached pages to smb_rqst::rq_buffer, an xarray, to use as a bounce buffer for encryption. An XARRAY-type iterator can then be used to pass the bounce buffer to lower layers. Signed-off-by: David Howells <dhowells@redhat.com> cc: Steve French <sfrench@samba.org> cc: Shyam Prasad N <nspmangalore@gmail.com> cc: Rohith Surabattula <rohiths.msft@gmail.com> cc: Paulo Alcantara <pc@cjr.nz> cc: Jeff Layton <jlayton@kernel.org> cc: linux-cifs@vger.kernel.org Link: https://lore.kernel.org/r/164311907995.2806745.400147335497304099.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/164928620163.457102.11602306234438271112.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/165211420279.3154751.15923591172438186144.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/165348880385.2106726.3220789453472800240.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/165364827111.3334034.934805882842932881.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/166126396180.708021.271013668175370826.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/166697259595.61150.5982032408321852414.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/166732031756.3186319.12528413619888902872.stgit@warthog.procyon.org.uk/ # rfc Signed-off-by: Steve French <stfrench@microsoft.com>
2022-01-24 21:13:24 +00:00
select NETFS_SUPPORT
help
This is the client VFS module for the SMB3 family of network file
protocols (including the most recent, most secure dialect SMB3.1.1).
This module also includes support for earlier dialects such as
SMB2.1, SMB2 and even the old Common Internet File System (CIFS)
protocol. CIFS was the successor to the original network filesystem
protocol, Server Message Block (SMB ie SMB1), the native file sharing
mechanism for most early PC operating systems.
The SMB3.1.1 protocol is supported by most modern operating systems
and NAS appliances (e.g. Samba, Windows 11, Windows Server 2022,
MacOS) and even in the cloud (e.g. Microsoft Azure) and also by the
Linux kernel server, ksmbd. Support for the older CIFS protocol was
included in Windows NT4, 2000 and XP (and later). Use of dialects
older than SMB2.1 is often discouraged on public networks.
This module also provides limited support for OS/2 and Windows ME
and similar very old servers.
This module provides an advanced network file system client for
mounting to SMB3 (and CIFS) compliant servers. It includes support
for DFS (hierarchical name space), secure per-user session
establishment via Kerberos or NTLMv2, RDMA (smbdirect), advanced
security features, per-share encryption, packet-signing, snapshots,
directory leases, safe distributed caching (leases), multichannel,
Unicode and other internationalization improvements.
In general, the default dialects, SMB3 and later, enable better
performance, security and features, than would be possible with CIFS.
If you need to mount to Samba, Azure, ksmbd, Macs or Windows from this
machine, say Y.
config CIFS_STATS2
bool "Extended statistics"
depends on CIFS
default y
help
Enabling this option will allow more detailed statistics on SMB
request timing to be displayed in /proc/fs/cifs/DebugData and also
allow optional logging of slow responses to dmesg (depending on the
value of /proc/fs/cifs/cifsFYI). See Documentation/admin-guide/cifs/usage.rst
for more details. These additional statistics may have a minor effect
on performance and memory utilization.
If unsure, say Y.
config CIFS_ALLOW_INSECURE_LEGACY
bool "Support legacy servers which use less secure dialects"
depends on CIFS
default y
help
Modern dialects, SMB2.1 and later (including SMB3 and 3.1.1), have
additional security features, including protection against
man-in-the-middle attacks and stronger crypto hashes, so the use
of legacy dialects (SMB1/CIFS and SMB2.0) is discouraged.
Disabling this option prevents users from using vers=1.0 or vers=2.0
on mounts with cifs.ko
If unsure, say Y.
config CIFS_UPCALL
DNS: Separate out CIFS DNS Resolver code Separate out the DNS resolver key type from the CIFS filesystem into its own module so that it can be made available for general use, including the AFS filesystem module. This facility makes it possible for the kernel to upcall to userspace to have it issue DNS requests, package up the replies and present them to the kernel in a useful form. The kernel is then able to cache the DNS replies as keys can be retained in keyrings. Resolver keys are of type "dns_resolver" and have a case-insensitive description that is of the form "[<type>:]<domain_name>". The optional <type> indicates the particular DNS lookup and packaging that's required. The <domain_name> is the query to be made. If <type> isn't given, a basic hostname to IP address lookup is made, and the result is stored in the key in the form of a printable string consisting of a comma-separated list of IPv4 and IPv6 addresses. This key type is supported by userspace helpers driven from /sbin/request-key and configured through /etc/request-key.conf. The cifs.upcall utility is invoked for UNC path server name to IP address resolution. The CIFS functionality is encapsulated by the dns_resolve_unc_to_ip() function, which is used to resolve a UNC path to an IP address for CIFS filesystem. This part remains in the CIFS module for now. See the added Documentation/networking/dns_resolver.txt for more information. Signed-off-by: Wang Lei <wang840925@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-08-04 14:16:33 +00:00
bool "Kerberos/SPNEGO advanced session setup"
depends on CIFS
DNS: Separate out CIFS DNS Resolver code Separate out the DNS resolver key type from the CIFS filesystem into its own module so that it can be made available for general use, including the AFS filesystem module. This facility makes it possible for the kernel to upcall to userspace to have it issue DNS requests, package up the replies and present them to the kernel in a useful form. The kernel is then able to cache the DNS replies as keys can be retained in keyrings. Resolver keys are of type "dns_resolver" and have a case-insensitive description that is of the form "[<type>:]<domain_name>". The optional <type> indicates the particular DNS lookup and packaging that's required. The <domain_name> is the query to be made. If <type> isn't given, a basic hostname to IP address lookup is made, and the result is stored in the key in the form of a printable string consisting of a comma-separated list of IPv4 and IPv6 addresses. This key type is supported by userspace helpers driven from /sbin/request-key and configured through /etc/request-key.conf. The cifs.upcall utility is invoked for UNC path server name to IP address resolution. The CIFS functionality is encapsulated by the dns_resolve_unc_to_ip() function, which is used to resolve a UNC path to an IP address for CIFS filesystem. This part remains in the CIFS module for now. See the added Documentation/networking/dns_resolver.txt for more information. Signed-off-by: Wang Lei <wang840925@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-08-04 14:16:33 +00:00
help
Enables an upcall mechanism for CIFS which accesses userspace helper
utilities to provide SPNEGO packaged (RFC 4178) Kerberos tickets
which are needed to mount to certain secure servers (for which more
secure Kerberos authentication is required). If unsure, say Y.
config CIFS_XATTR
bool "CIFS extended attributes"
depends on CIFS
help
Extended attributes are name:value pairs associated with inodes by
the kernel or by users (see the attr(5) manual page for details).
CIFS maps the name of extended attributes beginning with the user
namespace prefix to SMB/CIFS EAs. EAs are stored on Windows
servers without the user namespace prefix, but their names are
seen by Linux cifs clients prefaced by the user namespace prefix.
The system namespace (used by some filesystems to store ACLs) is
not supported at this time.
If unsure, say Y.
config CIFS_POSIX
bool "CIFS POSIX Extensions"
depends on CIFS && CIFS_ALLOW_INSECURE_LEGACY && CIFS_XATTR
help
Enabling this option will cause the cifs client to attempt to
negotiate a feature of the older cifs dialect with servers, such as
Samba 3.0.5 or later, that optionally can handle more POSIX like
(rather than Windows like) file behavior. It also enables support
for POSIX ACLs (getfacl and setfacl) to servers (such as Samba 3.10
and later) which can negotiate CIFS POSIX ACL support. This config
option is not needed when mounting with SMB3.1.1. If unsure, say N.
config CIFS_DEBUG
bool "Enable CIFS debugging routines"
default y
depends on CIFS
help
Enabling this option adds helpful debugging messages to
the cifs code which increases the size of the cifs module.
If unsure, say Y.
config CIFS_DEBUG2
bool "Enable additional CIFS debugging routines"
depends on CIFS_DEBUG
help
Enabling this option adds a few more debugging routines
to the cifs code which slightly increases the size of
the cifs module and can cause additional logging of debug
messages in some error paths, slowing performance. This
option can be turned off unless you are debugging
cifs problems. If unsure, say N.
config CIFS_DEBUG_DUMP_KEYS
bool "Dump encryption keys for offline decryption (Unsafe)"
depends on CIFS_DEBUG
help
Enabling this will dump the encryption and decryption keys
used to communicate on an encrypted share connection on the
console. This allows Wireshark to decrypt and dissect
encrypted network captures. Enable this carefully.
If unsure, say N.
config CIFS_DFS_UPCALL
bool "DFS feature support"
depends on CIFS
help
Distributed File System (DFS) support is used to access shares
transparently in an enterprise name space, even if the share
moves to a different server. This feature also enables
an upcall mechanism for CIFS which contacts userspace helper
utilities to provide server name resolution (host names to
IP addresses) which is needed in order to reconnect to
servers if their addresses change or for implicit mounts of
DFS junction points. If unsure, say Y.
config CIFS_SWN_UPCALL
bool "SWN feature support"
depends on CIFS
help
The Service Witness Protocol (SWN) is used to get notifications
from a highly available server of resource state changes. This
feature enables an upcall mechanism for CIFS which contacts a
userspace daemon to establish the DCE/RPC connection to retrieve
the cluster available interfaces and resource change notifications.
If unsure, say Y.
config CIFS_NFSD_EXPORT
bool "Allow nfsd to export CIFS file system"
depends on CIFS && BROKEN
help
Allows NFS server to export a CIFS mounted share (nfsd over cifs)
if CIFS
config CIFS_SMB_DIRECT
bool "SMB Direct support"
depends on CIFS=m && INFINIBAND && INFINIBAND_ADDR_TRANS || CIFS=y && INFINIBAND=y && INFINIBAND_ADDR_TRANS=y
help
Enables SMB Direct support for SMB 3.0, 3.02 and 3.1.1.
SMB Direct allows transferring SMB packets over RDMA. If unsure,
say Y.
config CIFS_FSCACHE
bool "Provide CIFS client caching support"
cifs: Support fscache indexing rewrite Change the cifs filesystem to take account of the changes to fscache's indexing rewrite and reenable caching in cifs. The following changes have been made: (1) The fscache_netfs struct is no more, and there's no need to register the filesystem as a whole. (2) The session cookie is now an fscache_volume cookie, allocated with fscache_acquire_volume(). That takes three parameters: a string representing the "volume" in the index, a string naming the cache to use (or NULL) and a u64 that conveys coherency metadata for the volume. For cifs, I've made it render the volume name string as: "cifs,<ipaddress>,<sharename>" where the sharename has '/' characters replaced with ';'. This probably needs rethinking a bit as the total name could exceed the maximum filename component length. Further, the coherency data is currently just set to 0. It needs something else doing with it - I wonder if it would suffice simply to sum the resource_id, vol_create_time and vol_serial_number or maybe hash them. (3) The fscache_cookie_def is no more and needed information is passed directly to fscache_acquire_cookie(). The cache no longer calls back into the filesystem, but rather metadata changes are indicated at other times. fscache_acquire_cookie() is passed the same keying and coherency information as before. (4) The functions to set/reset cookies are removed and fscache_use_cookie() and fscache_unuse_cookie() are used instead. fscache_use_cookie() is passed a flag to indicate if the cookie is opened for writing. fscache_unuse_cookie() is passed updates for the metadata if we changed it (ie. if the file was opened for writing). These are called when the file is opened or closed. (5) cifs_setattr_*() are made to call fscache_resize() to change the size of the cache object. (6) The functions to read and write data are stubbed out pending a conversion to use netfslib. Changes ======= ver #8: - Abstract cache invalidation into a helper function. - Fix some checkpatch warnings[3]. ver #7: - Removed the accidentally added-back call to get the super cookie in cifs_root_iget(). - Fixed the right call to cifs_fscache_get_super_cookie() to take account of the "-o fsc" mount flag. ver #6: - Moved the change of gfpflags_allow_blocking() to current_is_kswapd() for cifs here. - Fixed one of the error paths in cifs_atomic_open() to jump around the call to use the cookie. - Fixed an additional successful return in the middle of cifs_open() to use the cookie on the way out. - Only get a volume cookie (and thus inode cookies) when "-o fsc" is supplied to mount. ver #5: - Fixed a couple of bits of cookie handling[2]: - The cookie should be released in cifs_evict_inode(), not cifsFileInfo_put_final(). The cookie needs to persist beyond file closure so that writepages will be able to write to it. - fscache_use_cookie() needs to be called in cifs_atomic_open() as it is for cifs_open(). ver #4: - Fixed the use of sizeof with memset. - tcon->vol_create_time is __le64 so doesn't need cpu_to_le64(). ver #3: - Canonicalise the cifs coherency data to make the cache portable. - Set volume coherency data. ver #2: - Use gfpflags_allow_blocking() rather than using flag directly. - Upgraded to -rc4 to allow for upstream changes[1]. - fscache_acquire_volume() now returns errors. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Jeff Layton <jlayton@kernel.org> cc: Steve French <smfrench@gmail.com> cc: Shyam Prasad N <nspmangalore@gmail.com> cc: linux-cifs@vger.kernel.org cc: linux-cachefs@redhat.com Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=23b55d673d7527b093cd97b7c217c82e70cd1af0 [1] Link: https://lore.kernel.org/r/3419813.1641592362@warthog.procyon.org.uk/ [2] Link: https://lore.kernel.org/r/CAH2r5muTanw9pJqzAHd01d9A8keeChkzGsCEH6=0rHutVLAF-A@mail.gmail.com/ [3] Link: https://lore.kernel.org/r/163819671009.215744.11230627184193298714.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906982979.143852.10672081929614953210.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967187187.1823006.247415138444991444.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021579335.640689.2681324337038770579.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/3462849.1641593783@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/1318953.1642024578@warthog.procyon.org.uk/ # v6 Signed-off-by: Steve French <stfrench@microsoft.com>
2020-11-17 15:56:59 +00:00
depends on CIFS=m && FSCACHE || CIFS=y && FSCACHE=y
help
Makes CIFS FS-Cache capable. Say Y here if you want your CIFS data
to be cached locally on disk through the general filesystem cache
manager. If unsure, say N.
config CIFS_ROOT
bool "SMB root file system (Experimental)"
depends on CIFS=y && IP_PNP
help
Enables root file system support over SMB protocol.
Most people say N here.
config CIFS_COMPRESSION
bool "SMB message compression (Experimental)"
depends on CIFS
default n
help
Enables over-the-wire message compression for SMB 3.1.1
mounts when negotiated with the server.
Only write requests with data size >= PAGE_SIZE will be
compressed to avoid wasting resources.
Say Y here if you want SMB traffic to be compressed.
If unsure, say N.
endif