Merge tag '5.15-rc-first-ksmbd-merge' of git://git.samba.org/ksmbd

Pull initial ksmbd implementation from Steve French:
 "Initial merge of kernel smb3 file server, ksmbd.

  The SMB family of protocols is the most widely deployed network
  filesystem protocol, the default on Windows and Macs (and even on many
  phones and tablets), with clients and servers on all major operating
  systems, but lacked a kernel server for Linux. For many cases the
  current userspace server choices were suboptimal either due to memory
  footprint, performance or difficulty integrating well with advanced
  Linux features.

  ksmbd is a new kernel module which implements the server-side of the
  SMB3 protocol. The target is to provide optimized performance, GPLv2
  SMB server, and better lease handling (distributed caching). The
  bigger goal is to add new features more rapidly (e.g. RDMA aka
  "smbdirect", and recent encryption and signing improvements to the
  protocol) which are easier to develop on a smaller, more tightly
  optimized kernel server than for example in Samba.

  The Samba project is much broader in scope (tools, security services,
  LDAP, Active Directory Domain Controller, and a cross platform file
  server for a wider variety of purposes) but the user space file server
  portion of Samba has proved hard to optimize for some Linux workloads,
  including for smaller devices.

  This is not meant to replace Samba, but rather be an extension to
  allow better optimizing for Linux, and will continue to integrate well
  with Samba user space tools and libraries where appropriate. Working
  with the Samba team we have already made sure that the configuration
  files and xattrs are in a compatible format between the kernel and
  user space server.

  Various types of functional and regression tests are regularly run
  against it. One example is the automated 'buildbot' regression tests
  which use the Linux client to test against ksmbd, e.g.

     http://smb3-test-rhel-75.southcentralus.cloudapp.azure.com/#/builders/8/builds/56

  but other test suites, including Samba's smbtorture functional test
  suite are also used regularly"

* tag '5.15-rc-first-ksmbd-merge' of git://git.samba.org/ksmbd: (219 commits)
  ksmbd: fix __write_overflow warning in ndr_read_string
  MAINTAINERS: ksmbd: add cifs_common directory to ksmbd entry
  MAINTAINERS: ksmbd: update my email address
  ksmbd: fix permission check issue on chown and chmod
  ksmbd: don't set FILE DELETE and FILE_DELETE_CHILD in access mask by default
  MAINTAINERS: add git adddress of ksmbd
  ksmbd: update SMB3 multi-channel support in ksmbd.rst
  ksmbd: smbd: fix kernel oops during server shutdown
  ksmbd: remove select FS_POSIX_ACL in Kconfig
  ksmbd: use proper errno instead of -1 in smb2_get_ksmbd_tcon()
  ksmbd: update the comment for smb2_get_ksmbd_tcon()
  ksmbd: change int data type to boolean
  ksmbd: Fix multi-protocol negotiation
  ksmbd: fix an oops in error handling in smb2_open()
  ksmbd: add ipv6_addr_v4mapped check to know if connection from client is ipv4
  ksmbd: fix missing error code in smb2_lock
  ksmbd: use channel signingkey for binding SMB2 session setup
  ksmbd: don't set RSS capable in FSCTL_QUERY_NETWORK_INTERFACE_INFO
  ksmbd: Return STATUS_OBJECT_PATH_NOT_FOUND if smb2_creat() returns ENOENT
  ksmbd: fix -Wstringop-truncation warnings
  ...

3 files changed, 176 insertions, 1 deletions

diff --git a/Documentation/filesystems/cifs/index.rst b/Documentation/filesystems/cifs/index.rst
new file mode 100644
index 000000000000..1c8597a679ab
--- /dev/null
+++ b/Documentation/filesystems/cifs/index.rst
@@ -0,0 +1,10 @@
+===============================
+CIFS
+===============================
+
+
+.. toctree::
+   :maxdepth: 1
+
+   ksmbd
+   cifsroot
diff --git a/Documentation/filesystems/cifs/ksmbd.rst b/Documentation/filesystems/cifs/ksmbd.rst
new file mode 100644
index 000000000000..a1326157d53f
--- /dev/null
+++ b/Documentation/filesystems/cifs/ksmbd.rst
@@ -0,0 +1,165 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==========================
+KSMBD - SMB3 Kernel Server
+==========================
+
+KSMBD is a linux kernel server which implements SMB3 protocol in kernel space
+for sharing files over network.
+
+KSMBD architecture
+==================
+
+The subset of performance related operations belong in kernelspace and
+the other subset which belong to operations which are not really related with
+performance in userspace. So, DCE/RPC management that has historically resulted
+into number of buffer overflow issues and dangerous security bugs and user
+account management are implemented in user space as ksmbd.mountd.
+File operations that are related with performance (open/read/write/close etc.)
+in kernel space (ksmbd). This also allows for easier integration with VFS
+interface for all file operations.
+
+ksmbd (kernel daemon)
+---------------------
+
+When the server daemon is started, It starts up a forker thread
+(ksmbd/interface name) at initialization time and open a dedicated port 445
+for listening to SMB requests. Whenever new clients make request, Forker
+thread will accept the client connection and fork a new thread for dedicated
+communication channel between the client and the server. It allows for parallel
+processing of SMB requests(commands) from clients as well as allowing for new
+clients to make new connections. Each instance is named ksmbd/1~n(port number)
+to indicate connected clients. Depending on the SMB request types, each new
+thread can decide to pass through the commands to the user space (ksmbd.mountd),
+currently DCE/RPC commands are identified to be handled through the user space.
+To further utilize the linux kernel, it has been chosen to process the commands
+as workitems and to be executed in the handlers of the ksmbd-io kworker threads.
+It allows for multiplexing of the handlers as the kernel take care of initiating
+extra worker threads if the load is increased and vice versa, if the load is
+decreased it destroys the extra worker threads. So, after connection is
+established with client. Dedicated ksmbd/1..n(port number) takes complete
+ownership of receiving/parsing of SMB commands. Each received command is worked
+in parallel i.e., There can be multiple clients commands which are worked in
+parallel. After receiving each command a separated kernel workitem is prepared
+for each command which is further queued to be handled by ksmbd-io kworkers.
+So, each SMB workitem is queued to the kworkers. This allows the benefit of load
+sharing to be managed optimally by the default kernel and optimizing client
+performance by handling client commands in parallel.
+
+ksmbd.mountd (user space daemon)
+--------------------------------
+
+ksmbd.mountd is userspace process to, transfer user account and password that
+are registered using ksmbd.adduser(part of utils for user space). Further it
+allows sharing information parameters that parsed from smb.conf to ksmbd in
+kernel. For the execution part it has a daemon which is continuously running
+and connected to the kernel interface using netlink socket, it waits for the
+requests(dcerpc and share/user info). It handles RPC calls (at a minimum few
+dozen) that are most important for file server from NetShareEnum and
+NetServerGetInfo. Complete DCE/RPC response is prepared from the user space
+and passed over to the associated kernel thread for the client.
+
+
+KSMBD Feature Status
+====================
+
+============================== =================================================
+Feature name                   Status
+============================== =================================================
+Dialects                       Supported. SMB2.1 SMB3.0, SMB3.1.1 dialects
+                               (intentionally excludes security vulnerable SMB1
+                               dialect).
+Auto Negotiation               Supported.
+Compound Request               Supported.
+Oplock Cache Mechanism         Supported.
+SMB2 leases(v1 lease)          Supported.
+Directory leases(v2 lease)     Planned for future.
+Multi-credits                  Supported.
+NTLM/NTLMv2                    Supported.
+HMAC-SHA256 Signing            Supported.
+Secure negotiate               Supported.
+Signing Update                 Supported.
+Pre-authentication integrity   Supported.
+SMB3 encryption(CCM, GCM)      Supported. (CCM and GCM128 supported, GCM256 in
+                               progress)
+SMB direct(RDMA)               Partially Supported. SMB3 Multi-channel is
+                               required to connect to Windows client.
+SMB3 Multi-channel             Partially Supported. Planned to implement
+                               replay/retry mechanisms for future.
+SMB3.1.1 POSIX extension       Supported.
+ACLs                           Partially Supported. only DACLs available, SACLs
+                               (auditing) is planned for the future. For
+                               ownership (SIDs) ksmbd generates random subauth
+                               values(then store it to disk) and use uid/gid
+                               get from inode as RID for local domain SID.
+                               The current acl implementation is limited to
+                               standalone server, not a domain member.
+                               Integration with Samba tools is being worked on
+                               to allow future support for running as a domain
+                               member.
+Kerberos                       Supported.
+Durable handle v1,v2           Planned for future.
+Persistent handle              Planned for future.
+SMB2 notify                    Planned for future.
+Sparse file support            Supported.
+DCE/RPC support                Partially Supported. a few calls(NetShareEnumAll,
+                               NetServerGetInfo, SAMR, LSARPC) that are needed
+                               for file server handled via netlink interface
+                               from ksmbd.mountd. Additional integration with
+                               Samba tools and libraries via upcall is being
+                               investigated to allow support for additional
+                               DCE/RPC management calls (and future support
+                               for Witness protocol e.g.)
+ksmbd/nfsd interoperability    Planned for future. The features that ksmbd
+                               support are Leases, Notify, ACLs and Share modes.
+============================== =================================================
+
+
+How to run
+==========
+
+1. Download ksmbd-tools and compile them.
+	- https://github.com/cifsd-team/ksmbd-tools
+
+2. Create user/password for SMB share.
+
+	# mkdir /etc/ksmbd/
+	# ksmbd.adduser -a <Enter USERNAME for SMB share access>
+
+3. Create /etc/ksmbd/smb.conf file, add SMB share in smb.conf file
+	- Refer smb.conf.example and
+          https://github.com/cifsd-team/ksmbd-tools/blob/master/Documentation/configuration.txt
+
+4. Insert ksmbd.ko module
+
+	# insmod ksmbd.ko
+
+5. Start ksmbd user space daemon
+	# ksmbd.mountd
+
+6. Access share from Windows or Linux using CIFS
+
+Shutdown KSMBD
+==============
+
+1. kill user and kernel space daemon
+	# sudo ksmbd.control -s
+
+How to turn debug print on
+==========================
+
+Each layer
+/sys/class/ksmbd-control/debug
+
+1. Enable all component prints
+	# sudo ksmbd.control -d "all"
+
+2. Enable one of components(smb, auth, vfs, oplock, ipc, conn, rdma)
+	# sudo ksmbd.control -d "smb"
+
+3. Show what prints are enable.
+	# cat/sys/class/ksmbd-control/debug
+	  [smb] auth vfs oplock ipc conn [rdma]
+
+4. Disable prints:
+	If you try the selected component once more, It is disabled without brackets.
diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst
index 246af51b277a..7e1f44c14e6f 100644
--- a/Documentation/filesystems/index.rst
+++ b/Documentation/filesystems/index.rst
@@ -72,7 +72,7 @@ Documentation for filesystem implementations.
    befs
    bfs
    btrfs
-   cifs/cifsroot
+   cifs/index
    ceph
    coda
    configfs