cifsd: add server handler for central processing and tranport layers

This adds server handler for central processing,
transport layers(tcp, rdma, ipc) and a document describing cifsd
architecture.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: NHyunchul Lee <hyc.lee@gmail.com>
Acked-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Documentation/filesystems/cifs/cifsd.rst

+.. SPDX-License-Identifier: GPL-2.0
+
+=========================
+CIFSD - SMB3 Kernel Server
+=========================
+
+CIFSD is a linux kernel server which implements SMB3 protocol in kernel space
+for sharing files over network.
+
+CIFSD 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.
+
+Key Features
+============
+
+The supported features are:
+ * SMB3 protocols for basic file sharing
+ * Auto negotiation
+ * Compound requests
+ * Oplock/Lease
+ * Large MTU
+ * NTLM/NTLMv2
+ * HMAC-SHA256 Signing
+ * Secure negotiate
+ * Signing Update
+ * Pre-authentication integrity(SMB 3.1.1)
+ * SMB3 encryption(CCM, GCM)
+ * SMB direct(RDMA)
+ * SMB3.1.1 POSIX extension support
+ * ACLs
+ * Kerberos
+
+The features that are planned or not supported:
+ * SMB3 Multi-channel
+ * Durable handle v1,v2
+ * Persistent handles
+ * Directory lease
+ * SMB2 notify
+
+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 Documentation/configuration.txt
+	  in ksmbd-tools
+
+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 CIFSD
+==============
+
+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.

fs/cifsd/connection.c

+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   Copyright (C) 2016 Namjae Jeon <namjae.jeon@protocolfreedom.org>
+ *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/mutex.h>
+#include <linux/freezer.h>
+#include <linux/module.h>
+
+#include "server.h"
+#include "buffer_pool.h"
+#include "smb_common.h"
+#include "mgmt/ksmbd_ida.h"
+#include "connection.h"
+#include "transport_tcp.h"
+#include "transport_rdma.h"
+
+static DEFINE_MUTEX(init_lock);
+
+static struct ksmbd_conn_ops default_conn_ops;
+
+static LIST_HEAD(conn_list);
+static DEFINE_RWLOCK(conn_list_lock);
+
+/**
+ * ksmbd_conn_free() - free resources of the connection instance
+ *
+ * @conn:	connection instance to be cleand up
+ *
+ * During the thread termination, the corresponding conn instance
+ * resources(sock/memory) are released and finally the conn object is freed.
+ */
+void ksmbd_conn_free(struct ksmbd_conn *conn)
+{
+	write_lock(&conn_list_lock);
+	list_del(&conn->conns_list);
+	write_unlock(&conn_list_lock);
+
+	ksmbd_free_request(conn->request_buf);
+	ksmbd_ida_free(conn->async_ida);
+	kfree(conn->preauth_info);
+	kfree(conn);
+}
+
+/**
+ * ksmbd_conn_alloc() - initialize a new connection instance
+ *
+ * Return:	ksmbd_conn struct on success, otherwise NULL
+ */
+struct ksmbd_conn *ksmbd_conn_alloc(void)
+{
+	struct ksmbd_conn *conn;
+
+	conn = kzalloc(sizeof(struct ksmbd_conn), GFP_KERNEL);
+	if (!conn)
+		return NULL;
+
+	conn->need_neg = true;
+	conn->status = KSMBD_SESS_NEW;
+	conn->local_nls = load_nls("utf8");
+	if (!conn->local_nls)
+		conn->local_nls = load_nls_default();
+	atomic_set(&conn->req_running, 0);
+	atomic_set(&conn->r_count, 0);
+	init_waitqueue_head(&conn->req_running_q);
+	INIT_LIST_HEAD(&conn->conns_list);
+	INIT_LIST_HEAD(&conn->sessions);
+	INIT_LIST_HEAD(&conn->requests);
+	INIT_LIST_HEAD(&conn->async_requests);
+	spin_lock_init(&conn->request_lock);
+	spin_lock_init(&conn->credits_lock);
+	conn->async_ida = ksmbd_ida_alloc();
+
+	write_lock(&conn_list_lock);
+	list_add(&conn->conns_list, &conn_list);
+	write_unlock(&conn_list_lock);
+	return conn;
+}
+
+bool ksmbd_conn_lookup_dialect(struct ksmbd_conn *c)
+{
+	struct ksmbd_conn *t;
+	bool ret = false;
+
+	read_lock(&conn_list_lock);
+	list_for_each_entry(t, &conn_list, conns_list) {
+		if (memcmp(t->ClientGUID, c->ClientGUID, SMB2_CLIENT_GUID_SIZE))
+			continue;
+
+		ret = true;
+		break;
+	}
+	read_unlock(&conn_list_lock);
+	return ret;
+}
+
+void ksmbd_conn_enqueue_request(struct ksmbd_work *work)
+{
+	struct ksmbd_conn *conn = work->conn;
+	struct list_head *requests_queue = NULL;
+
+	if (conn->ops->get_cmd_val(work) != SMB2_CANCEL_HE) {
+		requests_queue = &conn->requests;
+		work->syncronous = true;
+	}
+
+	if (requests_queue) {
+		atomic_inc(&conn->req_running);
+		spin_lock(&conn->request_lock);
+		list_add_tail(&work->request_entry, requests_queue);
+		spin_unlock(&conn->request_lock);
+	}
+}
+
+int ksmbd_conn_try_dequeue_request(struct ksmbd_work *work)
+{
+	struct ksmbd_conn *conn = work->conn;
+	int ret = 1;
+
+	if (list_empty(&work->request_entry) &&
+		list_empty(&work->async_request_entry))
+		return 0;
+
+	atomic_dec(&conn->req_running);
+	spin_lock(&conn->request_lock);
+	if (!work->multiRsp) {
+		list_del_init(&work->request_entry);
+		if (work->syncronous == false)
+			list_del_init(&work->async_request_entry);
+		ret = 0;
+	}
+	spin_unlock(&conn->request_lock);
+
+	wake_up_all(&conn->req_running_q);
+	return ret;
+}
+
+static void ksmbd_conn_lock(struct ksmbd_conn *conn)
+{
+	mutex_lock(&conn->srv_mutex);
+}
+
+static void ksmbd_conn_unlock(struct ksmbd_conn *conn)
+{
+	mutex_unlock(&conn->srv_mutex);
+}
+
+void ksmbd_conn_wait_idle(struct ksmbd_conn *conn)
+{
+	wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
+}
+
+int ksmbd_conn_write(struct ksmbd_work *work)
+{
+	struct ksmbd_conn *conn = work->conn;
+	struct smb_hdr *rsp_hdr = RESPONSE_BUF(work);
+	size_t len = 0;
+	int sent;
+	struct kvec iov[3];
+	int iov_idx = 0;
+
+	ksmbd_conn_try_dequeue_request(work);
+	if (!rsp_hdr) {
+		ksmbd_err("NULL response header\n");
+		return -EINVAL;
+	}
+
+	if (HAS_TRANSFORM_BUF(work)) {
+		iov[iov_idx] = (struct kvec) { work->tr_buf,
+				sizeof(struct smb2_transform_hdr) };
+		len += iov[iov_idx++].iov_len;
+	}
+
+	if (HAS_AUX_PAYLOAD(work)) {
+		iov[iov_idx] = (struct kvec) { rsp_hdr, RESP_HDR_SIZE(work) };
+		len += iov[iov_idx++].iov_len;
+		iov[iov_idx] = (struct kvec) { AUX_PAYLOAD(work),
+			AUX_PAYLOAD_SIZE(work) };
+		len += iov[iov_idx++].iov_len;
+	} else {
+		if (HAS_TRANSFORM_BUF(work))
+			iov[iov_idx].iov_len = RESP_HDR_SIZE(work);
+		else
+			iov[iov_idx].iov_len = get_rfc1002_len(rsp_hdr) + 4;
+		iov[iov_idx].iov_base = rsp_hdr;
+		len += iov[iov_idx++].iov_len;
+	}
+
+	ksmbd_conn_lock(conn);
+	sent = conn->transport->ops->writev(conn->transport, &iov[0],
+					iov_idx, len,
+					work->need_invalidate_rkey,
+					work->remote_key);
+	ksmbd_conn_unlock(conn);
+
+	if (sent < 0) {
+		ksmbd_err("Failed to send message: %d\n", sent);
+		return sent;
+	}
+
+	return 0;
+}
+
+int ksmbd_conn_rdma_read(struct ksmbd_conn *conn,
+				void *buf, unsigned int buflen,
+				u32 remote_key, u64 remote_offset,
+				u32 remote_len)
+{
+	int ret = -EINVAL;
+
+	if (conn->transport->ops->rdma_read)
+		ret = conn->transport->ops->rdma_read(conn->transport,
+						buf, buflen,
+						remote_key, remote_offset,
+						remote_len);
+	return ret;
+}
+
+int ksmbd_conn_rdma_write(struct ksmbd_conn *conn,
+				void *buf, unsigned int buflen,
+				u32 remote_key, u64 remote_offset,
+				u32 remote_len)
+{
+	int ret = -EINVAL;
+
+	if (conn->transport->ops->rdma_write)
+		ret = conn->transport->ops->rdma_write(conn->transport,
+						buf, buflen,
+						remote_key, remote_offset,
+						remote_len);
+	return ret;
+}
+
+bool ksmbd_conn_alive(struct ksmbd_conn *conn)
+{
+	if (!ksmbd_server_running())
+		return false;
+
+	if (conn->status == KSMBD_SESS_EXITING)
+		return false;
+
+	if (kthread_should_stop())
+		return false;
+
+	if (atomic_read(&conn->stats.open_files_count) > 0)
+		return true;
+
+	/*
+	 * Stop current session if the time that get last request from client
+	 * is bigger than deadtime user configured and openning file count is
+	 * zero.
+	 */
+	if (server_conf.deadtime > 0 &&
+		time_after(jiffies, conn->last_active + server_conf.deadtime)) {
+		ksmbd_debug(CONN, "No response from client in %lu minutes\n",
+			server_conf.deadtime / SMB_ECHO_INTERVAL);
+		return false;
+	}
+	return true;
+}
+
+/**
+ * ksmbd_conn_handler_loop() - session thread to listen on new smb requests
+ * @p:		connection instance
+ *
+ * One thread each per connection
+ *
+ * Return:	0 on success
+ */
+int ksmbd_conn_handler_loop(void *p)
+{
+	struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
+	struct ksmbd_transport *t = conn->transport;
+	unsigned int pdu_size;
+	char hdr_buf[4] = {0,};
+	int size;
+
+	mutex_init(&conn->srv_mutex);
+	__module_get(THIS_MODULE);
+
+	if (t->ops->prepare && t->ops->prepare(t))
+		goto out;
+
+	conn->last_active = jiffies;
+	while (ksmbd_conn_alive(conn)) {
+		if (try_to_freeze())
+			continue;
+
+		ksmbd_free_request(conn->request_buf);
+		conn->request_buf = NULL;
+
+		size = t->ops->read(t, hdr_buf, sizeof(hdr_buf));
+		if (size != sizeof(hdr_buf))
+			break;
+
+		pdu_size = get_rfc1002_len(hdr_buf);
+		ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
+
+		/* make sure we have enough to get to SMB header end */
+		if (!ksmbd_pdu_size_has_room(pdu_size)) {
+			ksmbd_debug(CONN, "SMB request too short (%u bytes)\n",
+				    pdu_size);
+			continue;
+		}
+
+		/* 4 for rfc1002 length field */
+		size = pdu_size + 4;
+		conn->request_buf = ksmbd_alloc_request(size);
+		if (!conn->request_buf)
+			continue;
+
+		memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
+		if (!ksmbd_smb_request(conn))
+			break;
+
+		/*
+		 * We already read 4 bytes to find out PDU size, now
+		 * read in PDU
+		 */
+		size = t->ops->read(t, conn->request_buf + 4, pdu_size);
+		if (size < 0) {
+			ksmbd_err("sock_read failed: %d\n", size);
+			break;
+		}
+
+		if (size != pdu_size) {
+			ksmbd_err("PDU error. Read: %d, Expected: %d\n",
+				  size,
+				  pdu_size);
+			continue;
+		}
+
+		if (!default_conn_ops.process_fn) {
+			ksmbd_err("No connection request callback\n");
+			break;
+		}
+
+		if (default_conn_ops.process_fn(conn)) {
+			ksmbd_err("Cannot handle request\n");
+			break;
+		}
+	}
+
+out:
+	/* Wait till all reference dropped to the Server object*/
+	while (atomic_read(&conn->r_count) > 0)
+		schedule_timeout(HZ);
+
+	unload_nls(conn->local_nls);
+	if (default_conn_ops.terminate_fn)
+		default_conn_ops.terminate_fn(conn);
+	t->ops->disconnect(t);
+	module_put(THIS_MODULE);
+	return 0;
+}
+
+void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
+{
+	default_conn_ops.process_fn = ops->process_fn;
+	default_conn_ops.terminate_fn = ops->terminate_fn;
+}
+
+int ksmbd_conn_transport_init(void)
+{
+	int ret;
+
+	mutex_lock(&init_lock);
+	ret = ksmbd_tcp_init();
+	if (ret) {
+		pr_err("Failed to init TCP subsystem: %d\n", ret);
+		goto out;
+	}
+
+	ret = ksmbd_rdma_init();
+	if (ret) {
+		pr_err("Failed to init KSMBD subsystem: %d\n", ret);
+		goto out;
+	}
+out:
+	mutex_unlock(&init_lock);
+	return ret;
+}
+
+static void stop_sessions(void)
+{
+	struct ksmbd_conn *conn;
+
+again:
+	read_lock(&conn_list_lock);
+	list_for_each_entry(conn, &conn_list, conns_list) {
+		struct task_struct *task;
+
+		task = conn->transport->handler;
+		if (task)
+			ksmbd_debug(CONN, "Stop session handler %s/%d\n",
+				  task->comm,
+				  task_pid_nr(task));
+		conn->status = KSMBD_SESS_EXITING;
+	}
+	read_unlock(&conn_list_lock);
+
+	if (!list_empty(&conn_list)) {
+		schedule_timeout_interruptible(HZ/10); /* 100ms */
+		goto again;
+	}
+}
+
+void ksmbd_conn_transport_destroy(void)
+{
+	mutex_lock(&init_lock);
+	ksmbd_tcp_destroy();
+	ksmbd_rdma_destroy();
+	stop_sessions();
+	mutex_unlock(&init_lock);
+}

fs/cifsd/connection.h

+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
+ */
+
+#ifndef __KSMBD_CONNECTION_H__
+#define __KSMBD_CONNECTION_H__
+
+#include <linux/list.h>
+#include <linux/ip.h>
+#include <net/sock.h>
+#include <net/tcp.h>
+#include <net/inet_connection_sock.h>
+#include <net/request_sock.h>
+#include <linux/kthread.h>
+#include <linux/nls.h>
+
+#include "smb_common.h"
+#include "ksmbd_work.h"
+
+#define KSMBD_SOCKET_BACKLOG		16
+
+/*
+ * WARNING
+ *
+ * This is nothing but a HACK. Session status should move to channel
+ * or to session. As of now we have 1 tcp_conn : 1 ksmbd_session, but
+ * we need to change it to 1 tcp_conn : N ksmbd_sessions.
+ */
+enum {
+	KSMBD_SESS_NEW = 0,
+	KSMBD_SESS_GOOD,
+	KSMBD_SESS_EXITING,
+	KSMBD_SESS_NEED_RECONNECT,
+	KSMBD_SESS_NEED_NEGOTIATE
+};
+
+struct ksmbd_stats {
+	atomic_t			open_files_count;
+	atomic64_t			request_served;
+};
+
+struct ksmbd_transport;
+
+struct ksmbd_conn {
+	struct smb_version_values	*vals;
+	struct smb_version_ops		*ops;
+	struct smb_version_cmds		*cmds;
+	unsigned int			max_cmds;
+	struct mutex			srv_mutex;
+	int				status;
+	unsigned int			cli_cap;
+	char				*request_buf;
+	struct ksmbd_transport		*transport;
+	struct nls_table		*local_nls;
+	struct list_head		conns_list;
+	/* smb session 1 per user */
+	struct list_head		sessions;
+	unsigned long			last_active;
+	/* How many request are running currently */
+	atomic_t			req_running;
+	/* References which are made for this Server object*/
+	atomic_t			r_count;
+	unsigned short			total_credits;
+	unsigned short			max_credits;
+	spinlock_t			credits_lock;
+	wait_queue_head_t		req_running_q;
+	/* Lock to protect requests list*/
+	spinlock_t			request_lock;
+	struct list_head		requests;
+	struct list_head		async_requests;
+	int				connection_type;
+	struct ksmbd_stats		stats;
+	char				ClientGUID[SMB2_CLIENT_GUID_SIZE];
+	union {
+		/* pending trans request table */
+		struct trans_state	*recent_trans;
+		/* Used by ntlmssp */
+		char			*ntlmssp_cryptkey;
+	};
+
+	struct preauth_integrity_info	*preauth_info;
+
+	bool				need_neg;
+	unsigned int			auth_mechs;
+	unsigned int			preferred_auth_mech;
+	bool				sign;
+	bool				use_spnego:1;
+	__u16				cli_sec_mode;
+	__u16				srv_sec_mode;
+	/* dialect index that server chose */
+	__u16				dialect;
+
+	char				*mechToken;
+
+	struct ksmbd_conn_ops	*conn_ops;
+
+	/* Preauth Session Table */
+	struct list_head		preauth_sess_table;
+
+	struct sockaddr_storage		peer_addr;
+
+	/* Identifier for async message */
+	struct ksmbd_ida		*async_ida;
+
+	__le16				cipher_type;
+	__le16				compress_algorithm;
+	bool				posix_ext_supported;
+};
+
+struct ksmbd_conn_ops {
+	int	(*process_fn)(struct ksmbd_conn *conn);
+	int	(*terminate_fn)(struct ksmbd_conn *conn);
+};
+
+struct ksmbd_transport_ops {
+	int (*prepare)(struct ksmbd_transport *t);
+	void (*disconnect)(struct ksmbd_transport *t);
+	int (*read)(struct ksmbd_transport *t,
+			char *buf, unsigned int size);
+	int (*writev)(struct ksmbd_transport *t,
+			struct kvec *iovs, int niov, int size,
+			bool need_invalidate_rkey, unsigned int remote_key);
+	int (*rdma_read)(struct ksmbd_transport *t,
+				void *buf, unsigned int len, u32 remote_key,
+				u64 remote_offset, u32 remote_len);
+	int (*rdma_write)(struct ksmbd_transport *t,
+				void *buf, unsigned int len, u32 remote_key,
+				u64 remote_offset, u32 remote_len);
+};
+
+struct ksmbd_transport {
+	struct ksmbd_conn		*conn;
+	struct ksmbd_transport_ops	*ops;
+	struct task_struct		*handler;
+};
+
+#define KSMBD_TCP_RECV_TIMEOUT	(7 * HZ)
+#define KSMBD_TCP_SEND_TIMEOUT	(5 * HZ)
+#define KSMBD_TCP_PEER_SOCKADDR(c)	((struct sockaddr *)&((c)->peer_addr))
+
+bool ksmbd_conn_alive(struct ksmbd_conn *conn);
+void ksmbd_conn_wait_idle(struct ksmbd_conn *conn);
+
+struct ksmbd_conn *ksmbd_conn_alloc(void);
+void ksmbd_conn_free(struct ksmbd_conn *conn);
+bool ksmbd_conn_lookup_dialect(struct ksmbd_conn *c);
+int ksmbd_conn_write(struct ksmbd_work *work);
+int ksmbd_conn_rdma_read(struct ksmbd_conn *conn,
+				void *buf, unsigned int buflen,
+				u32 remote_key, u64 remote_offset,
+				u32 remote_len);
+int ksmbd_conn_rdma_write(struct ksmbd_conn *conn,
+				void *buf, unsigned int buflen,
+				u32 remote_key, u64 remote_offset,
+				u32 remote_len);
+
+void ksmbd_conn_enqueue_request(struct ksmbd_work *work);
+int ksmbd_conn_try_dequeue_request(struct ksmbd_work *work);
+void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops);
+
+int ksmbd_conn_handler_loop(void *p);
+
+int ksmbd_conn_transport_init(void);
+void ksmbd_conn_transport_destroy(void);
+
+/*
+ * WARNING
+ *
+ * This is a hack. We will move status to a proper place once we land
+ * a multi-sessions support.
+ */
+static inline bool ksmbd_conn_good(struct ksmbd_work *work)
+{
+	return work->conn->status == KSMBD_SESS_GOOD;
+}
+
+static inline bool ksmbd_conn_need_negotiate(struct ksmbd_work *work)
+{
+	return work->conn->status == KSMBD_SESS_NEED_NEGOTIATE;
+}
+
+static inline bool ksmbd_conn_need_reconnect(struct ksmbd_work *work)
+{
+	return work->conn->status == KSMBD_SESS_NEED_RECONNECT;
+}
+
+static inline bool ksmbd_conn_exiting(struct ksmbd_work *work)
+{
+	return work->conn->status == KSMBD_SESS_EXITING;
+}
+
+static inline void ksmbd_conn_set_good(struct ksmbd_work *work)
+{
+	work->conn->status = KSMBD_SESS_GOOD;
+}
+
+static inline void ksmbd_conn_set_need_negotiate(struct ksmbd_work *work)
+{
+	work->conn->status = KSMBD_SESS_NEED_NEGOTIATE;
+}
+
+static inline void ksmbd_conn_set_need_reconnect(struct ksmbd_work *work)
+{
+	work->conn->status = KSMBD_SESS_NEED_RECONNECT;
+}
+
+static inline void ksmbd_conn_set_exiting(struct ksmbd_work *work)
+{
+	work->conn->status = KSMBD_SESS_EXITING;
+}
+#endif /* __CONNECTION_H__ */

fs/cifsd/glob.h

+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *   Copyright (C) 2016 Namjae Jeon <linkinjeon@kernel.org>
+ *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
+ */
+
+#ifndef __KSMBD_GLOB_H
+#define __KSMBD_GLOB_H
+
+#include <linux/ctype.h>
+#include <linux/version.h>
+
+#include "unicode.h"
+#include "vfs_cache.h"
+#include "smberr.h"
+
+#define KSMBD_VERSION	"3.1.9"
+
+/* @FIXME clean up this code */
+
+extern int ksmbd_debug_types;
+extern int ksmbd_caseless_search;
+
+#define DATA_STREAM	1
+#define DIR_STREAM	2
+
+#define KSMBD_DEBUG_SMB         (1 << 0)
+#define KSMBD_DEBUG_AUTH        (1 << 1)
+#define KSMBD_DEBUG_VFS         (1 << 2)
+#define KSMBD_DEBUG_OPLOCK      (1 << 3)
+#define KSMBD_DEBUG_IPC         (1 << 4)
+#define KSMBD_DEBUG_CONN        (1 << 5)
+#define KSMBD_DEBUG_RDMA        (1 << 6)
+#define KSMBD_DEBUG_ALL         (KSMBD_DEBUG_SMB | KSMBD_DEBUG_AUTH |	\
+				KSMBD_DEBUG_VFS | KSMBD_DEBUG_OPLOCK |	\
+				KSMBD_DEBUG_IPC | KSMBD_DEBUG_CONN |	\
+				KSMBD_DEBUG_RDMA)
+
+#ifndef ksmbd_pr_fmt
+#ifdef SUBMOD_NAME
+#define ksmbd_pr_fmt(fmt)	"ksmbd: " SUBMOD_NAME ": " fmt
+#else
+#define ksmbd_pr_fmt(fmt)	"ksmbd: " fmt
+#endif
+#endif
+
+#define ksmbd_debug(type, fmt, ...)				\
+	do {							\
+		if (ksmbd_debug_types & KSMBD_DEBUG_##type)	\
+			pr_info(ksmbd_pr_fmt("%s:%d: " fmt),	\
+				__func__,			\
+				__LINE__,			\
+				##__VA_ARGS__);			\
+	} while (0)
+
+#define ksmbd_info(fmt, ...)					\
+			pr_info(ksmbd_pr_fmt(fmt), ##__VA_ARGS__)
+
+#define ksmbd_err(fmt, ...)					\
+			pr_err(ksmbd_pr_fmt("%s:%d: " fmt),	\
+				__func__,			\
+				__LINE__,			\
+				##__VA_ARGS__)
+
+#define UNICODE_LEN(x)		((x) * 2)
+
+#endif /* __KSMBD_GLOB_H */

fs/cifsd/ksmbd_server.h

+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
+ *
+ *   linux-ksmbd-devel@lists.sourceforge.net
+ */
+
+#ifndef _LINUX_KSMBD_SERVER_H
+#define _LINUX_KSMBD_SERVER_H
+
+#include <linux/types.h>
+
+#define KSMBD_GENL_NAME		"SMBD_GENL"
+#define KSMBD_GENL_VERSION		0x01
+
+#ifndef ____ksmbd_align
+#define ____ksmbd_align		__aligned(4)
+#endif
+
+#define KSMBD_REQ_MAX_ACCOUNT_NAME_SZ	48
+#define KSMBD_REQ_MAX_HASH_SZ		18
+#define KSMBD_REQ_MAX_SHARE_NAME	64
+
+struct ksmbd_heartbeat {
+	__u32	handle;
+};
+
+/*
+ * Global config flags.
+ */
+#define KSMBD_GLOBAL_FLAG_INVALID		(0)
+#define KSMBD_GLOBAL_FLAG_SMB2_LEASES		(1 << 0)
+#define KSMBD_GLOBAL_FLAG_CACHE_TBUF		(1 << 1)
+#define KSMBD_GLOBAL_FLAG_CACHE_RBUF		(1 << 2)
+#define KSMBD_GLOBAL_FLAG_SMB2_ENCRYPTION	(1 << 3)
+#define KSMBD_GLOBAL_FLAG_DURABLE_HANDLE	(1 << 4)
+
+struct ksmbd_startup_request {
+	__u32	flags;
+	__s32	signing;
+	__s8	min_prot[16];
+	__s8	max_prot[16];
+	__s8	netbios_name[16];
+	__s8	work_group[64];
+	__s8	server_string[64];
+	__u16	tcp_port;
+	__u16	ipc_timeout;
+	__u32	deadtime;
+	__u32	file_max;
+	__u32	smb2_max_write;
+	__u32	smb2_max_read;
+	__u32	smb2_max_trans;
+	__u32	share_fake_fscaps;
+	__u32	sub_auth[3];
+	__u32	ifc_list_sz;
+	__s8	____payload[0];
+} ____ksmbd_align;
+
+#define KSMBD_STARTUP_CONFIG_INTERFACES(s)	((s)->____payload)
+
+struct ksmbd_shutdown_request {
+	__s32	reserved;
+} ____ksmbd_align;
+
+struct ksmbd_login_request {
+	__u32	handle;
+	__s8	account[KSMBD_REQ_MAX_ACCOUNT_NAME_SZ];
+} ____ksmbd_align;
+
+struct ksmbd_login_response {
+	__u32	handle;
+	__u32	gid;
+	__u32	uid;
+	__s8	account[KSMBD_REQ_MAX_ACCOUNT_NAME_SZ];
+	__u16	status;
+	__u16	hash_sz;
+	__s8	hash[KSMBD_REQ_MAX_HASH_SZ];
+} ____ksmbd_align;
+
+struct ksmbd_share_config_request {
+	__u32	handle;
+	__s8	share_name[KSMBD_REQ_MAX_SHARE_NAME];
+} ____ksmbd_align;
+
+struct ksmbd_share_config_response {
+	__u32	handle;
+	__u32	flags;
+	__u16	create_mask;
+	__u16	directory_mask;
+	__u16	force_create_mode;
+	__u16	force_directory_mode;
+	__u16	force_uid;
+	__u16	force_gid;
+	__u32	veto_list_sz;
+	__s8	____payload[0];
+} ____ksmbd_align;
+
+#define KSMBD_SHARE_CONFIG_VETO_LIST(s)	((s)->____payload)
+#define KSMBD_SHARE_CONFIG_PATH(s)				\
+	({							\
+		char *p = (s)->____payload;			\
+		if ((s)->veto_list_sz)				\
+			p += (s)->veto_list_sz + 1;		\
+		p;						\
+	 })
+
+struct ksmbd_tree_connect_request {
+	__u32	handle;
+	__u16	account_flags;
+	__u16	flags;
+	__u64	session_id;
+	__u64	connect_id;
+	__s8	account[KSMBD_REQ_MAX_ACCOUNT_NAME_SZ];
+	__s8	share[KSMBD_REQ_MAX_SHARE_NAME];
+	__s8	peer_addr[64];
+} ____ksmbd_align;
+
+struct ksmbd_tree_connect_response {
+	__u32	handle;
+	__u16	status;
+	__u16	connection_flags;
+} ____ksmbd_align;
+
+struct ksmbd_tree_disconnect_request {
+	__u64	session_id;
+	__u64	connect_id;
+} ____ksmbd_align;
+
+struct ksmbd_logout_request {
+	__s8	account[KSMBD_REQ_MAX_ACCOUNT_NAME_SZ];
+} ____ksmbd_align;
+
+struct ksmbd_rpc_command {
+	__u32	handle;
+	__u32	flags;
+	__u32	payload_sz;
+	__u8	payload[0];
+} ____ksmbd_align;
+
+struct ksmbd_spnego_authen_request {
+	__u32	handle;
+	__u16	spnego_blob_len;
+	__u8	spnego_blob[0];
+} ____ksmbd_align;
+
+struct ksmbd_spnego_authen_response {
+	__u32	handle;
+	struct ksmbd_login_response	login_response;
+	__u16	session_key_len;
+	__u16	spnego_blob_len;
+	__u8	payload[0];		/* session key + AP_REP */
+} ____ksmbd_align;
+
+/*
+ * This also used as NETLINK attribute type value.
+ *
+ * NOTE:
+ * Response message type value should be equal to
+ * request message type value + 1.
+ */
+enum ksmbd_event {
+	KSMBD_EVENT_UNSPEC			= 0,
+	KSMBD_EVENT_HEARTBEAT_REQUEST,
+
+	KSMBD_EVENT_STARTING_UP,
+	KSMBD_EVENT_SHUTTING_DOWN,
+
+	KSMBD_EVENT_LOGIN_REQUEST,
+	KSMBD_EVENT_LOGIN_RESPONSE		= 5,
+
+	KSMBD_EVENT_SHARE_CONFIG_REQUEST,
+	KSMBD_EVENT_SHARE_CONFIG_RESPONSE,
+
+	KSMBD_EVENT_TREE_CONNECT_REQUEST,
+	KSMBD_EVENT_TREE_CONNECT_RESPONSE,
+
+	KSMBD_EVENT_TREE_DISCONNECT_REQUEST	= 10,
+
+	KSMBD_EVENT_LOGOUT_REQUEST,
+
+	KSMBD_EVENT_RPC_REQUEST,
+	KSMBD_EVENT_RPC_RESPONSE,
+
+	KSMBD_EVENT_SPNEGO_AUTHEN_REQUEST,
+	KSMBD_EVENT_SPNEGO_AUTHEN_RESPONSE	= 15,
+
+	KSMBD_EVENT_MAX
+};
+
+enum KSMBD_TREE_CONN_STATUS {
+	KSMBD_TREE_CONN_STATUS_OK		= 0,
+	KSMBD_TREE_CONN_STATUS_NOMEM,
+	KSMBD_TREE_CONN_STATUS_NO_SHARE,
+	KSMBD_TREE_CONN_STATUS_NO_USER,
+	KSMBD_TREE_CONN_STATUS_INVALID_USER,
+	KSMBD_TREE_CONN_STATUS_HOST_DENIED	= 5,
+	KSMBD_TREE_CONN_STATUS_CONN_EXIST,
+	KSMBD_TREE_CONN_STATUS_TOO_MANY_CONNS,
+	KSMBD_TREE_CONN_STATUS_TOO_MANY_SESSIONS,
+	KSMBD_TREE_CONN_STATUS_ERROR,
+};
+
+/*
+ * User config flags.
+ */
+#define KSMBD_USER_FLAG_INVALID		(0)
+#define KSMBD_USER_FLAG_OK		(1 << 0)
+#define KSMBD_USER_FLAG_BAD_PASSWORD	(1 << 1)
+#define KSMBD_USER_FLAG_BAD_UID		(1 << 2)
+#define KSMBD_USER_FLAG_BAD_USER	(1 << 3)
+#define KSMBD_USER_FLAG_GUEST_ACCOUNT	(1 << 4)
+
+/*
+ * Share config flags.
+ */
+#define KSMBD_SHARE_FLAG_INVALID		(0)
+#define KSMBD_SHARE_FLAG_AVAILABLE		(1 << 0)
+#define KSMBD_SHARE_FLAG_BROWSEABLE		(1 << 1)
+#define KSMBD_SHARE_FLAG_WRITEABLE		(1 << 2)
+#define KSMBD_SHARE_FLAG_READONLY		(1 << 3)
+#define KSMBD_SHARE_FLAG_GUEST_OK		(1 << 4)
+#define KSMBD_SHARE_FLAG_GUEST_ONLY		(1 << 5)
+#define KSMBD_SHARE_FLAG_STORE_DOS_ATTRS	(1 << 6)
+#define KSMBD_SHARE_FLAG_OPLOCKS		(1 << 7)
+#define KSMBD_SHARE_FLAG_PIPE			(1 << 8)
+#define KSMBD_SHARE_FLAG_HIDE_DOT_FILES		(1 << 9)
+#define KSMBD_SHARE_FLAG_INHERIT_SMACK		(1 << 10)
+#define KSMBD_SHARE_FLAG_INHERIT_OWNER		(1 << 11)
+#define KSMBD_SHARE_FLAG_STREAMS		(1 << 12)
+#define KSMBD_SHARE_FLAG_FOLLOW_SYMLINKS	(1 << 13)
+#define KSMBD_SHARE_FLAG_ACL_XATTR		(1 << 14)
+
+/*
+ * Tree connect request flags.
+ */
+#define KSMBD_TREE_CONN_FLAG_REQUEST_SMB1	(0)
+#define KSMBD_TREE_CONN_FLAG_REQUEST_IPV6	(1 << 0)
+#define KSMBD_TREE_CONN_FLAG_REQUEST_SMB2	(1 << 1)
+
+/*
+ * Tree connect flags.
+ */
+#define KSMBD_TREE_CONN_FLAG_GUEST_ACCOUNT	(1 << 0)
+#define KSMBD_TREE_CONN_FLAG_READ_ONLY		(1 << 1)
+#define KSMBD_TREE_CONN_FLAG_WRITABLE		(1 << 2)
+#define KSMBD_TREE_CONN_FLAG_ADMIN_ACCOUNT	(1 << 3)
+
+/*
+ * RPC over IPC.
+ */
+#define KSMBD_RPC_METHOD_RETURN		(1 << 0)
+#define KSMBD_RPC_SRVSVC_METHOD_INVOKE	(1 << 1)
+#define KSMBD_RPC_SRVSVC_METHOD_RETURN	((1 << 1) | KSMBD_RPC_METHOD_RETURN)
+#define KSMBD_RPC_WKSSVC_METHOD_INVOKE	(1 << 2)
+#define KSMBD_RPC_WKSSVC_METHOD_RETURN	((1 << 2) | KSMBD_RPC_METHOD_RETURN)
+#define KSMBD_RPC_IOCTL_METHOD		((1 << 3) | KSMBD_RPC_METHOD_RETURN)
+#define KSMBD_RPC_OPEN_METHOD		(1 << 4)
+#define KSMBD_RPC_WRITE_METHOD		(1 << 5)
+#define KSMBD_RPC_READ_METHOD		((1 << 6) | KSMBD_RPC_METHOD_RETURN)
+#define KSMBD_RPC_CLOSE_METHOD		(1 << 7)
+#define KSMBD_RPC_RAP_METHOD		((1 << 8) | KSMBD_RPC_METHOD_RETURN)
+#define KSMBD_RPC_RESTRICTED_CONTEXT	(1 << 9)
+#define KSMBD_RPC_SAMR_METHOD_INVOKE	(1 << 10)
+#define KSMBD_RPC_SAMR_METHOD_RETURN	((1 << 10) | KSMBD_RPC_METHOD_RETURN)
+#define KSMBD_RPC_LSARPC_METHOD_INVOKE	(1 << 11)
+#define KSMBD_RPC_LSARPC_METHOD_RETURN	((1 << 11) | KSMBD_RPC_METHOD_RETURN)
+
+#define KSMBD_RPC_OK			0
+#define KSMBD_RPC_EBAD_FUNC		0x00000001
+#define KSMBD_RPC_EACCESS_DENIED	0x00000005
+#define KSMBD_RPC_EBAD_FID		0x00000006
+#define KSMBD_RPC_ENOMEM		0x00000008
+#define KSMBD_RPC_EBAD_DATA		0x0000000D
+#define KSMBD_RPC_ENOTIMPLEMENTED	0x00000040
+#define KSMBD_RPC_EINVALID_PARAMETER	0x00000057
+#define KSMBD_RPC_EMORE_DATA		0x000000EA
+#define KSMBD_RPC_EINVALID_LEVEL	0x0000007C
+#define KSMBD_RPC_SOME_NOT_MAPPED	0x00000107
+
+#define KSMBD_CONFIG_OPT_DISABLED	0
+#define KSMBD_CONFIG_OPT_ENABLED	1
+#define KSMBD_CONFIG_OPT_AUTO		2
+#define KSMBD_CONFIG_OPT_MANDATORY	3
+
+#endif /* _LINUX_KSMBD_SERVER_H */

fs/cifsd/ksmbd_work.c

+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   Copyright (C) 2019 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/list.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+#include "server.h"
+#include "connection.h"
+#include "ksmbd_work.h"
+#include "buffer_pool.h"
+#include "mgmt/ksmbd_ida.h"
+
+/* @FIXME */
+#include "ksmbd_server.h"
+
+static struct kmem_cache *work_cache;
+static struct workqueue_struct *ksmbd_wq;
+
+struct ksmbd_work *ksmbd_alloc_work_struct(void)
+{
+	struct ksmbd_work *work = kmem_cache_zalloc(work_cache, GFP_KERNEL);
+
+	if (work) {
+		work->compound_fid = KSMBD_NO_FID;
+		work->compound_pfid = KSMBD_NO_FID;
+		INIT_LIST_HEAD(&work->request_entry);
+		INIT_LIST_HEAD(&work->async_request_entry);
+		INIT_LIST_HEAD(&work->fp_entry);
+		INIT_LIST_HEAD(&work->interim_entry);
+	}
+	return work;
+}
+
+void ksmbd_free_work_struct(struct ksmbd_work *work)
+{
+	WARN_ON(work->saved_cred != NULL);
+	if (server_conf.flags & KSMBD_GLOBAL_FLAG_CACHE_TBUF &&
+			work->set_trans_buf)
+		ksmbd_release_buffer(RESPONSE_BUF(work));
+	else
+		ksmbd_free_response(RESPONSE_BUF(work));
+
+	if (server_conf.flags & KSMBD_GLOBAL_FLAG_CACHE_RBUF &&
+			work->set_read_buf)
+		ksmbd_release_buffer(AUX_PAYLOAD(work));
+	else
+		ksmbd_free_response(AUX_PAYLOAD(work));
+
+	ksmbd_free_response(TRANSFORM_BUF(work));
+	ksmbd_free_request(REQUEST_BUF(work));
+	if (work->async_id)
+		ksmbd_release_id(work->conn->async_ida, work->async_id);
+	kmem_cache_free(work_cache, work);
+}
+
+void ksmbd_work_pool_destroy(void)
+{
+	kmem_cache_destroy(work_cache);
+}
+
+int ksmbd_work_pool_init(void)
+{
+	work_cache = kmem_cache_create("ksmbd_work_cache",
+					sizeof(struct ksmbd_work), 0,
+					SLAB_HWCACHE_ALIGN, NULL);
+	if (!work_cache)
+		return -ENOMEM;
+	return 0;
+}
+
+int ksmbd_workqueue_init(void)
+{
+	ksmbd_wq = alloc_workqueue("ksmbd-io", 0, 0);
+	if (!ksmbd_wq)
+		return -ENOMEM;
+	return 0;
+}
+
+void ksmbd_workqueue_destroy(void)
+{
+	flush_workqueue(ksmbd_wq);
+	destroy_workqueue(ksmbd_wq);
+	ksmbd_wq = NULL;
+}
+
+bool ksmbd_queue_work(struct ksmbd_work *work)
+{
+	return queue_work(ksmbd_wq, &work->work);
+}

fs/cifsd/ksmbd_work.h

+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *   Copyright (C) 2019 Samsung Electronics Co., Ltd.
+ */
+
+#ifndef __KSMBD_WORK_H__
+#define __KSMBD_WORK_H__
+
+#include <linux/ctype.h>
+#include <linux/workqueue.h>
+
+struct ksmbd_conn;
+struct ksmbd_session;
+struct ksmbd_tree_connect;
+
+enum {
+	KSMBD_WORK_ACTIVE = 0,
+	KSMBD_WORK_CANCELLED,
+	KSMBD_WORK_CLOSED,
+};
+
+/* one of these for every pending CIFS request at the connection */
+struct ksmbd_work {
+	/* Server corresponding to this mid */
+	struct ksmbd_conn               *conn;
+	struct ksmbd_session            *sess;
+	struct ksmbd_tree_connect       *tcon;
+
+	/* Pointer to received SMB header */
+	char                            *request_buf;
+	/* Response buffer */
+	char                            *response_buf;
+
+	/* Read data buffer */
+	char                            *aux_payload_buf;
+
+	/* Next cmd hdr in compound req buf*/
+	int                             next_smb2_rcv_hdr_off;
+	/* Next cmd hdr in compound rsp buf*/
+	int                             next_smb2_rsp_hdr_off;
+
+	/*
+	 * Current Local FID assigned compound response if SMB2 CREATE
+	 * command is present in compound request
+	 */
+	unsigned int                    compound_fid;
+	unsigned int                    compound_pfid;
+	unsigned int                    compound_sid;
+
+	const struct cred		*saved_cred;
+
+	/* Number of granted credits */
+	unsigned int			credits_granted;
+
+	/* response smb header size */
+	unsigned int                    resp_hdr_sz;
+	unsigned int                    response_sz;
+	/* Read data count */
+	unsigned int                    aux_payload_sz;
+
+	void				*tr_buf;
+
+	unsigned char			state;
+	/* Multiple responses for one request e.g. SMB ECHO */
+	bool                            multiRsp:1;
+	/* No response for cancelled request */
+	bool                            send_no_response:1;
+	/* Request is encrypted */
+	bool                            encrypted:1;
+	/* Is this SYNC or ASYNC ksmbd_work */
+	bool                            syncronous:1;
+	bool                            need_invalidate_rkey:1;
+	bool                            set_trans_buf:1;
+	bool                            set_read_buf:1;
+
+	unsigned int                    remote_key;
+	/* cancel works */
+	int                             async_id;
+	void                            **cancel_argv;
+	void                            (*cancel_fn)(void **argv);
+
+	struct work_struct              work;
+	/* List head at conn->requests */
+	struct list_head                request_entry;
+	/* List head at conn->async_requests */
+	struct list_head                async_request_entry;
+	struct list_head                fp_entry;
+	struct list_head                interim_entry;
+};
+
+#define WORK_CANCELLED(w)	((w)->state == KSMBD_WORK_CANCELLED)
+#define WORK_CLOSED(w)		((w)->state == KSMBD_WORK_CLOSED)
+#define WORK_ACTIVE(w)		((w)->state == KSMBD_WORK_ACTIVE)
+
+#define RESPONSE_BUF(w)		((void *)(w)->response_buf)
+#define REQUEST_BUF(w)		((void *)(w)->request_buf)
+
+#define RESPONSE_BUF_NEXT(w)	\
+	((void *)((w)->response_buf + (w)->next_smb2_rsp_hdr_off))
+#define REQUEST_BUF_NEXT(w)	\
+	((void *)((w)->request_buf + (w)->next_smb2_rcv_hdr_off))
+
+#define RESPONSE_SZ(w)		((w)->response_sz)
+
+#define INIT_AUX_PAYLOAD(w)	((w)->aux_payload_buf = NULL)
+#define HAS_AUX_PAYLOAD(w)	((w)->aux_payload_sz != 0)
+#define AUX_PAYLOAD(w)		((void *)((w)->aux_payload_buf))
+#define AUX_PAYLOAD_SIZE(w)	((w)->aux_payload_sz)
+#define RESP_HDR_SIZE(w)	((w)->resp_hdr_sz)
+
+#define HAS_TRANSFORM_BUF(w)	((w)->tr_buf != NULL)
+#define TRANSFORM_BUF(w)	((void *)((w)->tr_buf))
+
+struct ksmbd_work *ksmbd_alloc_work_struct(void);
+void ksmbd_free_work_struct(struct ksmbd_work *work);
+
+void ksmbd_work_pool_destroy(void);
+int ksmbd_work_pool_init(void);
+
+int ksmbd_workqueue_init(void);
+void ksmbd_workqueue_destroy(void);
+bool ksmbd_queue_work(struct ksmbd_work *work);
+
+#endif /* __KSMBD_WORK_H__ */

fs/cifsd/server.c

+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   Copyright (C) 2016 Namjae Jeon <linkinjeon@kernel.org>
+ *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
+ */
+
+#include "glob.h"
+#include "oplock.h"
+#include "misc.h"
+#include <linux/sched/signal.h>
+#include <linux/workqueue.h>
+#include <linux/sysfs.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+
+#include "server.h"
+#include "smb_common.h"
+#include "smbstatus.h"
+#include "buffer_pool.h"
+#include "connection.h"
+#include "transport_ipc.h"
+#include "mgmt/user_session.h"
+#include "crypto_ctx.h"
+#include "auth.h"
+
+int ksmbd_debug_types;
+
+struct ksmbd_server_config server_conf;
+
+enum SERVER_CTRL_TYPE {
+	SERVER_CTRL_TYPE_INIT,
+	SERVER_CTRL_TYPE_RESET,
+};
+
+struct server_ctrl_struct {
+	int			type;
+	struct work_struct	ctrl_work;
+};
+
+static DEFINE_MUTEX(ctrl_lock);
+
+static int ___server_conf_set(int idx, char *val)
+{
+	if (idx >= ARRAY_SIZE(server_conf.conf))
+		return -EINVAL;
+
+	if (!val || val[0] == 0x00)
+		return -EINVAL;
+
+	kfree(server_conf.conf[idx]);
+	server_conf.conf[idx] = kstrdup(val, GFP_KERNEL);
+	if (!server_conf.conf[idx])
+		return -ENOMEM;
+	return 0;
+}
+
+int ksmbd_set_netbios_name(char *v)
+{
+	return ___server_conf_set(SERVER_CONF_NETBIOS_NAME, v);
+}
+
+int ksmbd_set_server_string(char *v)
+{
+	return ___server_conf_set(SERVER_CONF_SERVER_STRING, v);
+}
+
+int ksmbd_set_work_group(char *v)
+{
+	return ___server_conf_set(SERVER_CONF_WORK_GROUP, v);
+}
+
+char *ksmbd_netbios_name(void)
+{
+	return server_conf.conf[SERVER_CONF_NETBIOS_NAME];
+}
+
+char *ksmbd_server_string(void)
+{
+	return server_conf.conf[SERVER_CONF_SERVER_STRING];
+}
+
+char *ksmbd_work_group(void)
+{
+	return server_conf.conf[SERVER_CONF_WORK_GROUP];
+}
+
+/**
+ * check_conn_state() - check state of server thread connection
+ * @ksmbd_work:     smb work containing server thread information
+ *
+ * Return:	0 on valid connection, otherwise 1 to reconnect
+ */
+static inline int check_conn_state(struct ksmbd_work *work)
+{
+	struct smb_hdr *rsp_hdr;
+
+	if (ksmbd_conn_exiting(work) || ksmbd_conn_need_reconnect(work)) {
+		rsp_hdr = RESPONSE_BUF(work);
+		rsp_hdr->Status.CifsError = STATUS_CONNECTION_DISCONNECTED;
+		return 1;
+	}
+	return 0;
+}
+
+/* @FIXME what a mess... god help. */
+
+#define TCP_HANDLER_CONTINUE	0
+#define TCP_HANDLER_ABORT	1
+
+static int __process_request(struct ksmbd_work *work,
+			     struct ksmbd_conn *conn,
+			     uint16_t *cmd)
+{
+	struct smb_version_cmds *cmds;
+	uint16_t command;
+	int ret;
+
+	if (check_conn_state(work))
+		return TCP_HANDLER_CONTINUE;
+
+	if (ksmbd_verify_smb_message(work))
+		return TCP_HANDLER_ABORT;
+
+	command = conn->ops->get_cmd_val(work);
+	*cmd = command;
+
+andx_again:
+	if (command >= conn->max_cmds) {
+		conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER);
+		return TCP_HANDLER_CONTINUE;
+	}
+
+	cmds = &conn->cmds[command];
+	if (!cmds->proc) {
+		ksmbd_debug(SMB, "*** not implemented yet cmd = %x\n", command);
+		conn->ops->set_rsp_status(work, STATUS_NOT_IMPLEMENTED);
+		return TCP_HANDLER_CONTINUE;
+	}
+
+	if (work->sess && conn->ops->is_sign_req(work, command)) {
+		ret = conn->ops->check_sign_req(work);
+		if (!ret) {
+			conn->ops->set_rsp_status(work, STATUS_ACCESS_DENIED);
+			return TCP_HANDLER_CONTINUE;
+		}
+	}
+
+	ret = cmds->proc(work);
+
+	if (ret < 0)
+		ksmbd_debug(CONN, "Failed to process %u [%d]\n", command, ret);
+	/* AndX commands - chained request can return positive values */
+	else if (ret > 0) {
+		command = ret;
+		*cmd = command;
+		goto andx_again;
+	}
+
+	if (work->send_no_response)
+		return TCP_HANDLER_ABORT;
+	return TCP_HANDLER_CONTINUE;
+}
+
+static void __handle_ksmbd_work(struct ksmbd_work *work,
+				struct ksmbd_conn *conn)
+{
+	uint16_t command = 0;
+	int rc;
+
+	if (conn->ops->allocate_rsp_buf(work))
+		return;
+
+	if (conn->ops->is_transform_hdr &&
+		conn->ops->is_transform_hdr(REQUEST_BUF(work))) {
+		rc = conn->ops->decrypt_req(work);
+		if (rc < 0) {
+			conn->ops->set_rsp_status(work, STATUS_DATA_ERROR);
+			goto send;
+		}
+
+		work->encrypted = true;
+	}
+
+	rc = conn->ops->init_rsp_hdr(work);
+	if (rc) {
+		/* either uid or tid is not correct */
+		conn->ops->set_rsp_status(work, STATUS_INVALID_HANDLE);
+		goto send;
+	}
+
+	if (conn->ops->check_user_session) {
+		rc = conn->ops->check_user_session(work);
+		if (rc < 0) {
+			command = conn->ops->get_cmd_val(work);
+			conn->ops->set_rsp_status(work,
+					STATUS_USER_SESSION_DELETED);
+			goto send;
+		} else if (rc > 0) {
+			rc = conn->ops->get_ksmbd_tcon(work);
+			if (rc < 0) {
+				conn->ops->set_rsp_status(work,
+					STATUS_NETWORK_NAME_DELETED);
+				goto send;
+			}
+		}
+	}
+
+	do {
+		rc = __process_request(work, conn, &command);
+		if (rc == TCP_HANDLER_ABORT)
+			break;
+
+		/*
+		 * Call smb2_set_rsp_credits() function to set number of credits
+		 * granted in hdr of smb2 response.
+		 */
+		if (conn->ops->set_rsp_credits) {
+			spin_lock(&conn->credits_lock);
+			rc = conn->ops->set_rsp_credits(work);
+			spin_unlock(&conn->credits_lock);
+			if (rc < 0) {
+				conn->ops->set_rsp_status(work,
+					STATUS_INVALID_PARAMETER);
+				goto send;
+			}
+		}
+
+		if (work->sess && (work->sess->sign ||
+		     smb3_11_final_sess_setup_resp(work) ||
+		     conn->ops->is_sign_req(work, command)))
+			conn->ops->set_sign_rsp(work);
+	} while (is_chained_smb2_message(work));
+
+	if (work->send_no_response)
+		return;
+
+send:
+	smb3_preauth_hash_rsp(work);
+	if (work->sess && work->sess->enc && work->encrypted &&
+		conn->ops->encrypt_resp) {
+		rc = conn->ops->encrypt_resp(work);
+		if (rc < 0) {
+			conn->ops->set_rsp_status(work, STATUS_DATA_ERROR);
+			goto send;
+		}
+	}
+
+	ksmbd_conn_write(work);
+}
+
+/**
+ * handle_ksmbd_work() - process pending smb work requests
+ * @ksmbd_work:	smb work containing request command buffer
+ *
+ * called by kworker threads to processing remaining smb work requests
+ */
+static void handle_ksmbd_work(struct work_struct *wk)
+{
+	struct ksmbd_work *work = container_of(wk, struct ksmbd_work, work);
+	struct ksmbd_conn *conn = work->conn;
+
+	atomic64_inc(&conn->stats.request_served);
+
+	__handle_ksmbd_work(work, conn);
+
+	ksmbd_conn_try_dequeue_request(work);
+	ksmbd_free_work_struct(work);
+	atomic_dec(&conn->r_count);
+}
+
+/**
+ * queue_ksmbd_work() - queue a smb request to worker thread queue
+ *		for proccessing smb command and sending response
+ * @conn:	connection instance
+ *
+ * read remaining data from socket create and submit work.
+ */
+static int queue_ksmbd_work(struct ksmbd_conn *conn)
+{
+	struct ksmbd_work *work;
+
+	work = ksmbd_alloc_work_struct();
+	if (!work) {
+		ksmbd_err("allocation for work failed\n");
+		return -ENOMEM;
+	}
+
+	work->conn = conn;
+	work->request_buf = conn->request_buf;
+	conn->request_buf = NULL;
+
+	if (ksmbd_init_smb_server(work)) {
+		ksmbd_free_work_struct(work);
+		return -EINVAL;
+	}
+
+	ksmbd_conn_enqueue_request(work);
+	atomic_inc(&conn->r_count);
+	/* update activity on connection */
+	conn->last_active = jiffies;
+	INIT_WORK(&work->work, handle_ksmbd_work);
+	ksmbd_queue_work(work);
+	return 0;
+}
+
+static int ksmbd_server_process_request(struct ksmbd_conn *conn)
+{
+	return queue_ksmbd_work(conn);
+}
+
+static int ksmbd_server_terminate_conn(struct ksmbd_conn *conn)
+{
+	ksmbd_sessions_deregister(conn);
+	destroy_lease_table(conn);
+	return 0;
+}
+
+static void ksmbd_server_tcp_callbacks_init(void)
+{
+	struct ksmbd_conn_ops ops;
+
+	ops.process_fn = ksmbd_server_process_request;
+	ops.terminate_fn = ksmbd_server_terminate_conn;
+
+	ksmbd_conn_init_server_callbacks(&ops);
+}
+
+static void server_conf_free(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(server_conf.conf); i++) {
+		kfree(server_conf.conf[i]);
+		server_conf.conf[i] = NULL;
+	}
+}
+
+static int server_conf_init(void)
+{
+	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
+	server_conf.enforced_signing = 0;
+	server_conf.min_protocol = ksmbd_min_protocol();
+	server_conf.max_protocol = ksmbd_max_protocol();
+	server_conf.auth_mechs = KSMBD_AUTH_NTLMSSP;
+#ifdef CONFIG_SMB_SERVER_KERBEROS5
+	server_conf.auth_mechs |= KSMBD_AUTH_KRB5 |
+				KSMBD_AUTH_MSKRB5;
+#endif
+	return 0;
+}
+
+static void server_ctrl_handle_init(struct server_ctrl_struct *ctrl)
+{
+	int ret;
+
+	ret = ksmbd_conn_transport_init();
+	if (ret) {
+		server_queue_ctrl_reset_work();
+		return;
+	}
+
+	WRITE_ONCE(server_conf.state, SERVER_STATE_RUNNING);
+}
+
+static void server_ctrl_handle_reset(struct server_ctrl_struct *ctrl)
+{
+	ksmbd_ipc_soft_reset();
+	ksmbd_conn_transport_destroy();
+	server_conf_free();
+	server_conf_init();
+	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
+}
+
+static void server_ctrl_handle_work(struct work_struct *work)
+{
+	struct server_ctrl_struct *ctrl;
+
+	ctrl = container_of(work, struct server_ctrl_struct, ctrl_work);
+
+	mutex_lock(&ctrl_lock);
+	switch (ctrl->type) {
+	case SERVER_CTRL_TYPE_INIT:
+		server_ctrl_handle_init(ctrl);
+		break;
+	case SERVER_CTRL_TYPE_RESET:
+		server_ctrl_handle_reset(ctrl);
+		break;
+	default:
+		pr_err("Unknown server work type: %d\n", ctrl->type);
+	}
+	mutex_unlock(&ctrl_lock);
+	kfree(ctrl);
+	module_put(THIS_MODULE);
+}
+
+static int __queue_ctrl_work(int type)
+{
+	struct server_ctrl_struct *ctrl;
+
+	ctrl = kmalloc(sizeof(struct server_ctrl_struct), GFP_KERNEL);
+	if (!ctrl)
+		return -ENOMEM;
+
+	__module_get(THIS_MODULE);
+	ctrl->type = type;
+	INIT_WORK(&ctrl->ctrl_work, server_ctrl_handle_work);
+	queue_work(system_long_wq, &ctrl->ctrl_work);
+	return 0;
+}
+
+int server_queue_ctrl_init_work(void)
+{
+	return __queue_ctrl_work(SERVER_CTRL_TYPE_INIT);
+}
+
+int server_queue_ctrl_reset_work(void)
+{
+	return __queue_ctrl_work(SERVER_CTRL_TYPE_RESET);
+}
+
+static ssize_t stats_show(struct class *class,
+			  struct class_attribute *attr,
+			  char *buf)
+{
+	/*
+	 * Inc this each time you change stats output format,
+	 * so user space will know what to do.
+	 */
+	static int stats_version = 2;
+	static const char * const state[] = {
+		"startup",
+		"running",
+		"reset",
+		"shutdown"
+	};
+
+	ssize_t sz = scnprintf(buf,
+				PAGE_SIZE,
+				"%d %s %d %lu\n",
+				stats_version,
+				state[server_conf.state],
+				server_conf.tcp_port,
+				server_conf.ipc_last_active / HZ);
+	return sz;
+}
+
+static ssize_t kill_server_store(struct class *class,
+				 struct class_attribute *attr,
+				 const char *buf,
+				 size_t len)
+{
+	if (!sysfs_streq(buf, "hard"))
+		return len;
+
+	ksmbd_info("kill command received\n");
+	mutex_lock(&ctrl_lock);
+	WRITE_ONCE(server_conf.state, SERVER_STATE_RESETTING);
+	__module_get(THIS_MODULE);
+	server_ctrl_handle_reset(NULL);
+	module_put(THIS_MODULE);
+	mutex_unlock(&ctrl_lock);
+	return len;
+}
+
+static const char * const debug_type_strings[] = {"smb", "auth", "vfs",
+						"oplock", "ipc", "conn",
+						"rdma"};
+
+static ssize_t debug_show(struct class *class,
+		struct class_attribute *attr,
+		char *buf)
+{
+	ssize_t sz = 0;
+	int i, pos = 0;
+
+	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
+		if ((ksmbd_debug_types >> i) & 1) {
+			pos = scnprintf(buf + sz,
+					PAGE_SIZE - sz,
+					"[%s] ",
+					debug_type_strings[i]);
+		} else {
+			pos = scnprintf(buf + sz,
+					PAGE_SIZE - sz,
+					"%s ",
+					debug_type_strings[i]);
+		}
+		sz += pos;
+
+	}
+	sz += scnprintf(buf + sz, PAGE_SIZE - sz, "\n");
+	return sz;
+}
+
+static ssize_t debug_store(struct class *class,
+		struct class_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
+		if (sysfs_streq(buf, "all")) {
+			if (ksmbd_debug_types == KSMBD_DEBUG_ALL)
+				ksmbd_debug_types = 0;
+			else
+				ksmbd_debug_types = KSMBD_DEBUG_ALL;
+			break;
+		}
+
+		if (sysfs_streq(buf, debug_type_strings[i])) {
+			if (ksmbd_debug_types & (1 << i))
+				ksmbd_debug_types &= ~(1 << i);
+			else
+				ksmbd_debug_types |= (1 << i);
+			break;
+		}
+	}
+
+	return len;
+}
+
+static CLASS_ATTR_RO(stats);
+static CLASS_ATTR_WO(kill_server);
+static CLASS_ATTR_RW(debug);
+
+static struct attribute *ksmbd_control_class_attrs[] = {
+	&class_attr_stats.attr,
+	&class_attr_kill_server.attr,
+	&class_attr_debug.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(ksmbd_control_class);
+
+static struct class ksmbd_control_class = {
+	.name		= "ksmbd-control",
+	.owner		= THIS_MODULE,
+	.class_groups	= ksmbd_control_class_groups,
+};
+
+static int ksmbd_server_shutdown(void)
+{
+	WRITE_ONCE(server_conf.state, SERVER_STATE_SHUTTING_DOWN);
+
+	class_unregister(&ksmbd_control_class);
+	ksmbd_workqueue_destroy();
+	ksmbd_ipc_release();
+	ksmbd_conn_transport_destroy();
+	ksmbd_free_session_table();
+	ksmbd_crypto_destroy();
+	ksmbd_free_global_file_table();
+	destroy_lease_table(NULL);
+	ksmbd_destroy_buffer_pools();
+	server_conf_free();
+	return 0;
+}
+
+static int __init ksmbd_server_init(void)
+{
+	int ret;
+
+	ret = class_register(&ksmbd_control_class);
+	if (ret) {
+		ksmbd_err("Unable to register ksmbd-control class\n");
+		return ret;
+	}
+
+	ksmbd_server_tcp_callbacks_init();
+
+	ret = server_conf_init();
+	if (ret)
+		return ret;
+
+	ret = ksmbd_init_buffer_pools();
+	if (ret)
+		return ret;
+
+	ret = ksmbd_init_session_table();
+	if (ret)
+		goto error;
+
+	ret = ksmbd_ipc_init();
+	if (ret)
+		goto error;
+
+	ret = ksmbd_init_global_file_table();
+	if (ret)
+		goto error;
+
+	ret = ksmbd_inode_hash_init();
+	if (ret)
+		goto error;
+
+	ret = ksmbd_crypto_create();
+	if (ret)
+		goto error;
+
+	ret = ksmbd_workqueue_init();
+	if (ret)
+		goto error;
+	return 0;
+
+error:
+	ksmbd_server_shutdown();
+	return ret;
+}
+
+/**
+ * exit_smb_server() - shutdown forker thread and free memory at module exit
+ */
+static void __exit ksmbd_server_exit(void)
+{
+	ksmbd_server_shutdown();
+	ksmbd_release_inode_hash();
+}
+
+MODULE_AUTHOR("Namjae Jeon <linkinjeon@kernel.org>");
+MODULE_VERSION(KSMBD_VERSION);
+MODULE_DESCRIPTION("Linux kernel CIFS/SMB SERVER");
+MODULE_LICENSE("GPL");
+MODULE_SOFTDEP("pre: arc4");
+MODULE_SOFTDEP("pre: ecb");
+MODULE_SOFTDEP("pre: hmac");
+MODULE_SOFTDEP("pre: md4");
+MODULE_SOFTDEP("pre: md5");
+MODULE_SOFTDEP("pre: nls");
+MODULE_SOFTDEP("pre: aes");
+MODULE_SOFTDEP("pre: cmac");
+MODULE_SOFTDEP("pre: sha256");
+MODULE_SOFTDEP("pre: sha512");
+MODULE_SOFTDEP("pre: aead2");
+MODULE_SOFTDEP("pre: ccm");
+MODULE_SOFTDEP("pre: gcm");
+module_init(ksmbd_server_init)
+module_exit(ksmbd_server_exit)

fs/cifsd/server.h

+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
+ */
+
+#ifndef __SERVER_H__
+#define __SERVER_H__
+
+#include "smbacl.h"
+
+#define SERVER_STATE_STARTING_UP	0
+#define SERVER_STATE_RUNNING		1
+#define SERVER_STATE_RESETTING		2
+#define SERVER_STATE_SHUTTING_DOWN	3
+
+#define SERVER_CONF_NETBIOS_NAME	0
+#define SERVER_CONF_SERVER_STRING	1
+#define SERVER_CONF_WORK_GROUP		2
+
+extern int ksmbd_debugging;
+
+struct ksmbd_server_config {
+	unsigned int		flags;
+	unsigned int		state;
+	short			signing;
+	short			enforced_signing;
+	short			min_protocol;
+	short			max_protocol;
+	unsigned short		tcp_port;
+	unsigned short		ipc_timeout;
+	unsigned long		ipc_last_active;
+	unsigned long		deadtime;
+	unsigned int		share_fake_fscaps;
+	struct smb_sid		domain_sid;
+	unsigned int		auth_mechs;
+
+	char			*conf[SERVER_CONF_WORK_GROUP + 1];
+};
+
+extern struct ksmbd_server_config server_conf;
+
+int ksmbd_set_netbios_name(char *v);
+int ksmbd_set_server_string(char *v);
+int ksmbd_set_work_group(char *v);
+
+char *ksmbd_netbios_name(void);
+char *ksmbd_server_string(void);
+char *ksmbd_work_group(void);
+
+static inline int ksmbd_server_running(void)
+{
+	return READ_ONCE(server_conf.state) == SERVER_STATE_RUNNING;
+}
+
+static inline int ksmbd_server_configurable(void)
+{
+	return READ_ONCE(server_conf.state) < SERVER_STATE_RESETTING;
+}
+
+int server_queue_ctrl_init_work(void);
+int server_queue_ctrl_reset_work(void);
+#endif /* __SERVER_H__ */

fs/cifsd/transport_ipc.h

+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
+ */
+
+#ifndef __KSMBD_TRANSPORT_IPC_H__
+#define __KSMBD_TRANSPORT_IPC_H__
+
+#include <linux/wait.h>
+#include "ksmbd_server.h"  /* FIXME */
+
+#define KSMBD_IPC_MAX_PAYLOAD	4096
+
+struct ksmbd_login_response *
+ksmbd_ipc_login_request(const char *account);
+
+struct ksmbd_session;
+struct ksmbd_share_config;
+struct ksmbd_tree_connect;
+struct sockaddr;
+
+struct ksmbd_tree_connect_response *
+ksmbd_ipc_tree_connect_request(struct ksmbd_session *sess,
+			       struct ksmbd_share_config *share,
+			       struct ksmbd_tree_connect *tree_conn,
+			       struct sockaddr *peer_addr);
+
+int ksmbd_ipc_tree_disconnect_request(unsigned long long session_id,
+				      unsigned long long connect_id);
+int ksmbd_ipc_logout_request(const char *account);
+
+struct ksmbd_share_config_response *
+ksmbd_ipc_share_config_request(const char *name);
+
+struct ksmbd_spnego_authen_response *
+ksmbd_ipc_spnego_authen_request(const char *spnego_blob, int blob_len);
+
+int ksmbd_ipc_id_alloc(void);
+void ksmbd_rpc_id_free(int handle);
+
+struct ksmbd_rpc_command *ksmbd_rpc_open(struct ksmbd_session *sess,
+					 int handle);
+struct ksmbd_rpc_command *ksmbd_rpc_close(struct ksmbd_session *sess,
+					  int handle);
+
+struct ksmbd_rpc_command *ksmbd_rpc_write(struct ksmbd_session *sess,
+					  int handle,
+					  void *payload,
+					  size_t payload_sz);
+struct ksmbd_rpc_command *ksmbd_rpc_read(struct ksmbd_session *sess,
+					 int handle);
+struct ksmbd_rpc_command *ksmbd_rpc_ioctl(struct ksmbd_session *sess,
+					  int handle,
+					  void *payload,
+					  size_t payload_sz);
+struct ksmbd_rpc_command *ksmbd_rpc_rap(struct ksmbd_session *sess,
+					  void *payload,
+					  size_t payload_sz);
+
+void ksmbd_ipc_release(void);
+void ksmbd_ipc_soft_reset(void);
+int ksmbd_ipc_init(void);
+#endif /* __KSMBD_TRANSPORT_IPC_H__ */

fs/cifsd/transport_rdma.h

+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *   Copyright (C) 2017, Microsoft Corporation.
+ *   Copyright (C) 2018, LG Electronics.
+ */
+
+#ifndef __KSMBD_TRANSPORT_RDMA_H__
+#define __KSMBD_TRANSPORT_RDMA_H__
+
+#define SMB_DIRECT_PORT	5445
+
+/* SMB DIRECT negotiation request packet [MS-KSMBD] 2.2.1 */
+struct smb_direct_negotiate_req {
+	__le16 min_version;
+	__le16 max_version;
+	__le16 reserved;
+	__le16 credits_requested;
+	__le32 preferred_send_size;
+	__le32 max_receive_size;
+	__le32 max_fragmented_size;
+} __packed;
+
+/* SMB DIRECT negotiation response packet [MS-KSMBD] 2.2.2 */
+struct smb_direct_negotiate_resp {
+	__le16 min_version;
+	__le16 max_version;
+	__le16 negotiated_version;
+	__le16 reserved;
+	__le16 credits_requested;
+	__le16 credits_granted;
+	__le32 status;
+	__le32 max_readwrite_size;
+	__le32 preferred_send_size;
+	__le32 max_receive_size;
+	__le32 max_fragmented_size;
+} __packed;
+
+#define SMB_DIRECT_RESPONSE_REQUESTED 0x0001
+
+/* SMB DIRECT data transfer packet with payload [MS-KSMBD] 2.2.3 */
+struct smb_direct_data_transfer {
+	__le16 credits_requested;
+	__le16 credits_granted;
+	__le16 flags;
+	__le16 reserved;
+	__le32 remaining_data_length;
+	__le32 data_offset;
+	__le32 data_length;
+	__le32 padding;
+	__u8 buffer[];
+} __packed;
+
+#ifdef CONFIG_SMB_SERVER_SMBDIRECT
+int ksmbd_rdma_init(void);
+int ksmbd_rdma_destroy(void);
+#else
+static inline int ksmbd_rdma_init(void) { return 0; }
+static inline int ksmbd_rdma_destroy(void) { return 0; }
+#endif
+
+#endif /* __KSMBD_TRANSPORT_RDMA_H__ */

fs/cifsd/transport_tcp.c

+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   Copyright (C) 2016 Namjae Jeon <linkinjeon@kernel.org>
+ *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/freezer.h>
+
+#include "smb_common.h"
+#include "server.h"
+#include "auth.h"
+#include "buffer_pool.h"
+#include "connection.h"
+#include "transport_tcp.h"
+
+#define IFACE_STATE_DOWN		(1 << 0)
+#define IFACE_STATE_CONFIGURED		(1 << 1)
+
+struct interface {
+	struct task_struct	*ksmbd_kthread;
+	struct socket		*ksmbd_socket;
+	struct list_head	entry;
+	char			*name;
+	struct mutex		sock_release_lock;
+	int			state;
+};
+
+static LIST_HEAD(iface_list);
+
+static int bind_additional_ifaces;
+
+struct tcp_transport {
+	struct ksmbd_transport		transport;
+	struct socket			*sock;
+	struct kvec			*iov;
+	unsigned int			nr_iov;
+};
+
+static struct ksmbd_transport_ops ksmbd_tcp_transport_ops;
+
+static void tcp_stop_kthread(struct task_struct *kthread);
+static struct interface *alloc_iface(char *ifname);
+
+#define KSMBD_TRANS(t)	(&(t)->transport)
+#define TCP_TRANS(t)	((struct tcp_transport *)container_of(t, \
+				struct tcp_transport, transport))
+
+static inline void ksmbd_tcp_nodelay(struct socket *sock)
+{
+	tcp_sock_set_nodelay(sock->sk);
+}
+
+static inline void ksmbd_tcp_reuseaddr(struct socket *sock)
+{
+	sock_set_reuseaddr(sock->sk);
+}
+
+static inline void ksmbd_tcp_rcv_timeout(struct socket *sock, s64 secs)
+{
+	lock_sock(sock->sk);
+	if (secs && secs < MAX_SCHEDULE_TIMEOUT / HZ - 1)
+		sock->sk->sk_rcvtimeo = secs * HZ;
+	else
+		sock->sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;
+	release_sock(sock->sk);
+}
+
+static inline void ksmbd_tcp_snd_timeout(struct socket *sock, s64 secs)
+{
+	sock_set_sndtimeo(sock->sk, secs);
+}
+
+static struct tcp_transport *alloc_transport(struct socket *client_sk)
+{
+	struct tcp_transport *t;
+	struct ksmbd_conn *conn;
+
+	t = kzalloc(sizeof(*t), GFP_KERNEL);
+	if (!t)
+		return NULL;
+	t->sock = client_sk;
+
+	conn = ksmbd_conn_alloc();
+	if (!conn) {
+		kfree(t);
+		return NULL;
+	}
+
+	conn->transport = KSMBD_TRANS(t);
+	KSMBD_TRANS(t)->conn = conn;
+	KSMBD_TRANS(t)->ops = &ksmbd_tcp_transport_ops;
+	return t;
+}
+
+static void free_transport(struct tcp_transport *t)
+{
+	kernel_sock_shutdown(t->sock, SHUT_RDWR);
+	sock_release(t->sock);
+	t->sock = NULL;
+
+	ksmbd_conn_free(KSMBD_TRANS(t)->conn);
+	kfree(t->iov);
+	kfree(t);
+}
+
+/**
+ * kvec_array_init() - initialize a IO vector segment
+ * @new:	IO vector to be initialized
+ * @iov:	base IO vector
+ * @nr_segs:	number of segments in base iov
+ * @bytes:	total iovec length so far for read
+ *
+ * Return:	Number of IO segments
+ */
+static unsigned int kvec_array_init(struct kvec *new, struct kvec *iov,
+				    unsigned int nr_segs, size_t bytes)
+{
+	size_t base = 0;
+
+	while (bytes || !iov->iov_len) {
+		int copy = min(bytes, iov->iov_len);
+
+		bytes -= copy;
+		base += copy;
+		if (iov->iov_len == base) {
+			iov++;
+			nr_segs--;
+			base = 0;
+		}
+	}
+
+	memcpy(new, iov, sizeof(*iov) * nr_segs);
+	new->iov_base += base;
+	new->iov_len -= base;
+	return nr_segs;
+}
+
+/**
+ * get_conn_iovec() - get connection iovec for reading from socket
+ * @t:		TCP transport instance
+ * @nr_segs:	number of segments in iov
+ *
+ * Return:	return existing or newly allocate iovec
+ */
+static struct kvec *get_conn_iovec(struct tcp_transport *t,
+				     unsigned int nr_segs)
+{
+	struct kvec *new_iov;
+
+	if (t->iov && nr_segs <= t->nr_iov)
+		return t->iov;
+
+	/* not big enough -- allocate a new one and release the old */
+	new_iov = kmalloc_array(nr_segs, sizeof(*new_iov), GFP_KERNEL);
+	if (new_iov) {
+		kfree(t->iov);
+		t->iov = new_iov;
+		t->nr_iov = nr_segs;
+	}
+	return new_iov;
+}
+
+static unsigned short ksmbd_tcp_get_port(const struct sockaddr *sa)
+{
+	switch (sa->sa_family) {
+	case AF_INET:
+		return ntohs(((struct sockaddr_in *)sa)->sin_port);
+	case AF_INET6:
+		return ntohs(((struct sockaddr_in6 *)sa)->sin6_port);
+	}
+	return 0;
+}
+
+/**
+ * ksmbd_tcp_new_connection() - create a new tcp session on mount
+ * @sock:	socket associated with new connection
+ *
+ * whenever a new connection is requested, create a conn thread
+ * (session thread) to handle new incoming smb requests from the connection
+ *
+ * Return:	0 on success, otherwise error
+ */
+static int ksmbd_tcp_new_connection(struct socket *client_sk)
+{
+	struct sockaddr *csin;
+	int rc = 0;
+	struct tcp_transport *t;
+
+	t = alloc_transport(client_sk);
+	if (!t)
+		return -ENOMEM;
+
+	csin = KSMBD_TCP_PEER_SOCKADDR(KSMBD_TRANS(t)->conn);
+	if (kernel_getpeername(client_sk, csin) < 0) {
+		ksmbd_err("client ip resolution failed\n");
+		rc = -EINVAL;
+		goto out_error;
+	}
+
+	KSMBD_TRANS(t)->handler = kthread_run(ksmbd_conn_handler_loop,
+					KSMBD_TRANS(t)->conn,
+					"ksmbd:%u", ksmbd_tcp_get_port(csin));
+	if (IS_ERR(KSMBD_TRANS(t)->handler)) {
+		ksmbd_err("cannot start conn thread\n");
+		rc = PTR_ERR(KSMBD_TRANS(t)->handler);
+		free_transport(t);
+	}
+	return rc;
+
+out_error:
+	free_transport(t);
+	return rc;
+}
+
+/**
+ * ksmbd_kthread_fn() - listen to new SMB connections and callback server
+ * @p:		arguments to forker thread
+ *
+ * Return:	Returns a task_struct or ERR_PTR
+ */
+static int ksmbd_kthread_fn(void *p)
+{
+	struct socket *client_sk = NULL;
+	struct interface *iface = (struct interface *)p;
+	int ret;
+
+	while (!kthread_should_stop()) {
+		mutex_lock(&iface->sock_release_lock);
+		if (!iface->ksmbd_socket) {
+			mutex_unlock(&iface->sock_release_lock);
+			break;
+		}
+		ret = kernel_accept(iface->ksmbd_socket, &client_sk,
+				O_NONBLOCK);
+		mutex_unlock(&iface->sock_release_lock);
+		if (ret) {
+			if (ret == -EAGAIN)
+				/* check for new connections every 100 msecs */
+				schedule_timeout_interruptible(HZ / 10);
+			continue;
+		}
+
+		ksmbd_debug(CONN, "connect success: accepted new connection\n");
+		client_sk->sk->sk_rcvtimeo = KSMBD_TCP_RECV_TIMEOUT;
+		client_sk->sk->sk_sndtimeo = KSMBD_TCP_SEND_TIMEOUT;
+
+		ksmbd_tcp_new_connection(client_sk);
+	}
+
+	ksmbd_debug(CONN, "releasing socket\n");
+	return 0;
+}
+
+/**
+ * ksmbd_create_ksmbd_kthread() - start forker thread
+ *
+ * start forker thread(ksmbd/0) at module init time to listen
+ * on port 445 for new SMB connection requests. It creates per connection
+ * server threads(ksmbd/x)
+ *
+ * Return:	0 on success or error number
+ */
+static int ksmbd_tcp_run_kthread(struct interface *iface)
+{
+	int rc;
+	struct task_struct *kthread;
+
+	kthread = kthread_run(ksmbd_kthread_fn, (void *)iface,
+		"ksmbd-%s", iface->name);
+	if (IS_ERR(kthread)) {
+		rc = PTR_ERR(kthread);
+		return rc;
+	}
+	iface->ksmbd_kthread = kthread;
+
+	return 0;
+}
+
+/**
+ * ksmbd_tcp_readv() - read data from socket in given iovec
+ * @t:		TCP transport instance
+ * @iov_orig:	base IO vector
+ * @nr_segs:	number of segments in base iov
+ * @to_read:	number of bytes to read from socket
+ *
+ * Return:	on success return number of bytes read from socket,
+ *		otherwise return error number
+ */
+static int ksmbd_tcp_readv(struct tcp_transport *t,
+			   struct kvec *iov_orig,
+			   unsigned int nr_segs,
+			   unsigned int to_read)
+{
+	int length = 0;
+	int total_read;
+	unsigned int segs;
+	struct msghdr ksmbd_msg;
+	struct kvec *iov;
+	struct ksmbd_conn *conn = KSMBD_TRANS(t)->conn;
+
+	iov = get_conn_iovec(t, nr_segs);
+	if (!iov)
+		return -ENOMEM;
+
+	ksmbd_msg.msg_control = NULL;
+	ksmbd_msg.msg_controllen = 0;
+
+	for (total_read = 0; to_read; total_read += length, to_read -= length) {
+		try_to_freeze();
+
+		if (!ksmbd_conn_alive(conn)) {
+			total_read = -ESHUTDOWN;
+			break;
+		}
+		segs = kvec_array_init(iov, iov_orig, nr_segs, total_read);
+
+		length = kernel_recvmsg(t->sock, &ksmbd_msg,
+					iov, segs, to_read, 0);
+
+		if (length == -EINTR) {
+			total_read = -ESHUTDOWN;
+			break;
+		} else if (conn->status == KSMBD_SESS_NEED_RECONNECT) {
+			total_read = -EAGAIN;
+			break;
+		} else if (length == -ERESTARTSYS || length == -EAGAIN) {
+			usleep_range(1000, 2000);
+			length = 0;
+			continue;
+		} else if (length <= 0) {
+			total_read = -EAGAIN;
+			break;
+		}
+	}
+	return total_read;
+}
+
+/**
+ * ksmbd_tcp_read() - read data from socket in given buffer
+ * @t:		TCP transport instance
+ * @buf:	buffer to store read data from socket
+ * @to_read:	number of bytes to read from socket
+ *
+ * Return:	on success return number of bytes read from socket,
+ *		otherwise return error number
+ */
+static int ksmbd_tcp_read(struct ksmbd_transport *t,
+		   char *buf,
+		   unsigned int to_read)
+{
+	struct kvec iov;
+
+	iov.iov_base = buf;
+	iov.iov_len = to_read;
+
+	return ksmbd_tcp_readv(TCP_TRANS(t), &iov, 1, to_read);
+}
+
+static int ksmbd_tcp_writev(struct ksmbd_transport *t,
+			struct kvec *iov, int nvecs, int size,
+			bool need_invalidate, unsigned int remote_key)
+
+{
+	struct msghdr smb_msg = {.msg_flags = MSG_NOSIGNAL};
+
+	return kernel_sendmsg(TCP_TRANS(t)->sock, &smb_msg, iov, nvecs, size);
+}
+
+static void ksmbd_tcp_disconnect(struct ksmbd_transport *t)
+{
+	free_transport(TCP_TRANS(t));
+}
+
+static void tcp_destroy_socket(struct socket *ksmbd_socket)
+{
+	int ret;
+
+	if (!ksmbd_socket)
+		return;
+
+	/* set zero to timeout */
+	ksmbd_tcp_rcv_timeout(ksmbd_socket, 0);
+	ksmbd_tcp_snd_timeout(ksmbd_socket, 0);
+
+	ret = kernel_sock_shutdown(ksmbd_socket, SHUT_RDWR);
+	if (ret)
+		ksmbd_err("Failed to shutdown socket: %d\n", ret);
+	else
+		sock_release(ksmbd_socket);
+}
+
+/**
+ * create_socket - create socket for ksmbd/0
+ *
+ * Return:	Returns a task_struct or ERR_PTR
+ */
+static int create_socket(struct interface *iface)
+{
+	int ret;
+	struct sockaddr_in6 sin6;
+	struct sockaddr_in sin;
+	struct socket *ksmbd_socket;
+	bool ipv4 = false;
+
+	ret = sock_create(PF_INET6, SOCK_STREAM, IPPROTO_TCP, &ksmbd_socket);
+	if (ret) {
+		ksmbd_err("Can't create socket for ipv6, try ipv4: %d\n", ret);
+		ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP,
+				&ksmbd_socket);
+		if (ret) {
+			ksmbd_err("Can't create socket for ipv4: %d\n", ret);
+			goto out_error;
+		}
+
+		sin.sin_family = PF_INET;
+		sin.sin_addr.s_addr = htonl(INADDR_ANY);
+		sin.sin_port = htons(server_conf.tcp_port);
+		ipv4 = true;
+	} else {
+		sin6.sin6_family = PF_INET6;
+		sin6.sin6_addr = in6addr_any;
+		sin6.sin6_port = htons(server_conf.tcp_port);
+	}
+
+	ksmbd_tcp_nodelay(ksmbd_socket);
+	ksmbd_tcp_reuseaddr(ksmbd_socket);
+
+	ret = sock_setsockopt(ksmbd_socket,
+				SOL_SOCKET,
+				SO_BINDTODEVICE,
+				KERNEL_SOCKPTR(iface->name),
+				strlen(iface->name));
+	if (ret != -ENODEV && ret < 0) {
+		ksmbd_err("Failed to set SO_BINDTODEVICE: %d\n", ret);
+		goto out_error;
+	}
+
+	if (ipv4)
+		ret = kernel_bind(ksmbd_socket, (struct sockaddr *)&sin,
+				sizeof(sin));
+	else
+		ret = kernel_bind(ksmbd_socket, (struct sockaddr *)&sin6,
+				sizeof(sin6));
+	if (ret) {
+		ksmbd_err("Failed to bind socket: %d\n", ret);
+		goto out_error;
+	}
+
+	ksmbd_socket->sk->sk_rcvtimeo = KSMBD_TCP_RECV_TIMEOUT;
+	ksmbd_socket->sk->sk_sndtimeo = KSMBD_TCP_SEND_TIMEOUT;
+
+	ret = kernel_listen(ksmbd_socket, KSMBD_SOCKET_BACKLOG);
+	if (ret) {
+		ksmbd_err("Port listen() error: %d\n", ret);
+		goto out_error;
+	}
+
+	iface->ksmbd_socket = ksmbd_socket;
+	ret = ksmbd_tcp_run_kthread(iface);
+	if (ret) {
+		ksmbd_err("Can't start ksmbd main kthread: %d\n", ret);
+		goto out_error;
+	}
+	iface->state = IFACE_STATE_CONFIGURED;
+
+	return 0;
+
+out_error:
+	tcp_destroy_socket(ksmbd_socket);
+	iface->ksmbd_socket = NULL;
+	return ret;
+}
+
+static int ksmbd_netdev_event(struct notifier_block *nb, unsigned long event,
+				void *ptr)
+{
+	struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
+	struct interface *iface;
+	int ret, found = 0;
+
+	switch (event) {
+	case NETDEV_UP:
+		if (netdev->priv_flags & IFF_BRIDGE_PORT)
+			return NOTIFY_OK;
+
+		list_for_each_entry(iface, &iface_list, entry) {
+			if (!strcmp(iface->name, netdev->name)) {
+				found = 1;
+				if (iface->state != IFACE_STATE_DOWN)
+					break;
+				ret = create_socket(iface);
+				if (ret)
+					return NOTIFY_OK;
+				break;
+			}
+		}
+		if (!found && bind_additional_ifaces) {
+			iface = alloc_iface(kstrdup(netdev->name, GFP_KERNEL));
+			if (!iface)
+				return NOTIFY_OK;
+			ret = create_socket(iface);
+			if (ret)
+				break;
+		}
+		break;
+	case NETDEV_DOWN:
+		list_for_each_entry(iface, &iface_list, entry) {
+			if (!strcmp(iface->name, netdev->name) &&
+			    iface->state == IFACE_STATE_CONFIGURED) {
+				tcp_stop_kthread(iface->ksmbd_kthread);
+				iface->ksmbd_kthread = NULL;
+				mutex_lock(&iface->sock_release_lock);
+				tcp_destroy_socket(iface->ksmbd_socket);
+				iface->ksmbd_socket = NULL;
+				mutex_unlock(&iface->sock_release_lock);
+
+				iface->state = IFACE_STATE_DOWN;
+				break;
+			}
+		}
+		break;
+	}
+
+	return NOTIFY_DONE;
+
+}
+
+static struct notifier_block ksmbd_netdev_notifier = {
+	.notifier_call = ksmbd_netdev_event,
+};
+
+int ksmbd_tcp_init(void)
+{
+	register_netdevice_notifier(&ksmbd_netdev_notifier);
+
+	return 0;
+}
+
+static void tcp_stop_kthread(struct task_struct *kthread)
+{
+	int ret;
+
+	if (!kthread)
+		return;
+
+	ret = kthread_stop(kthread);
+	if (ret)
+		ksmbd_err("failed to stop forker thread\n");
+}
+
+void ksmbd_tcp_destroy(void)
+{
+	struct interface *iface, *tmp;
+
+	unregister_netdevice_notifier(&ksmbd_netdev_notifier);
+
+	list_for_each_entry_safe(iface, tmp, &iface_list, entry) {
+		list_del(&iface->entry);
+		kfree(iface->name);
+		ksmbd_free(iface);
+	}
+}
+
+static struct interface *alloc_iface(char *ifname)
+{
+	struct interface *iface;
+
+	if (!ifname)
+		return NULL;
+
+	iface = ksmbd_alloc(sizeof(struct interface));
+	if (!iface) {
+		kfree(ifname);
+		return NULL;
+	}
+
+	iface->name = ifname;
+	iface->state = IFACE_STATE_DOWN;
+	list_add(&iface->entry, &iface_list);
+	mutex_init(&iface->sock_release_lock);
+	return iface;
+}
+
+int ksmbd_tcp_set_interfaces(char *ifc_list, int ifc_list_sz)
+{
+	int sz = 0;
+
+	if (!ifc_list_sz) {
+		struct net_device *netdev;
+
+		rtnl_lock();
+		for_each_netdev(&init_net, netdev) {
+			if (netdev->priv_flags & IFF_BRIDGE_PORT)
+				continue;
+			if (!alloc_iface(kstrdup(netdev->name, GFP_KERNEL)))
+				return -ENOMEM;
+		}
+		rtnl_unlock();
+		bind_additional_ifaces = 1;
+		return 0;
+	}
+
+	while (ifc_list_sz > 0) {
+		if (!alloc_iface(kstrdup(ifc_list, GFP_KERNEL)))
+			return -ENOMEM;
+
+		sz = strlen(ifc_list);
+		if (!sz)
+			break;
+
+		ifc_list += sz + 1;
+		ifc_list_sz -= (sz + 1);
+	}
+
+	bind_additional_ifaces = 0;
+
+	return 0;
+}
+
+static struct ksmbd_transport_ops ksmbd_tcp_transport_ops = {
+	.read		= ksmbd_tcp_read,
+	.writev		= ksmbd_tcp_writev,
+	.disconnect	= ksmbd_tcp_disconnect,
+};

fs/cifsd/transport_tcp.h

+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
+ */
+
+#ifndef __KSMBD_TRANSPORT_TCP_H__
+#define __KSMBD_TRANSPORT_TCP_H__
+
+int ksmbd_tcp_set_interfaces(char *ifc_list, int ifc_list_sz);
+int ksmbd_tcp_init(void);
+void ksmbd_tcp_destroy(void);
+
+#endif /* __KSMBD_TRANSPORT_TCP_H__ */