[PATCH v5 03/13] ksmbd: add tcp transport layer

From: Namjae Jeon
Date: Sun Jul 04 2021 - 23:17:57 EST


This adds tcp transport layer.

Signed-off-by: Namjae Jeon <namjae.jeon@xxxxxxxxxxx>
Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Signed-off-by: Hyunchul Lee <hyc.lee@xxxxxxxxx>
Acked-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
fs/ksmbd/connection.c | 409 ++++++++++++++++++++++++++
fs/ksmbd/connection.h | 205 +++++++++++++
fs/ksmbd/transport_tcp.c | 619 +++++++++++++++++++++++++++++++++++++++
fs/ksmbd/transport_tcp.h | 13 +
4 files changed, 1246 insertions(+)
create mode 100644 fs/ksmbd/connection.c
create mode 100644 fs/ksmbd/connection.h
create mode 100644 fs/ksmbd/transport_tcp.c
create mode 100644 fs/ksmbd/transport_tcp.h

diff --git a/fs/ksmbd/connection.c b/fs/ksmbd/connection.c
new file mode 100644
index 000000000000..928e22e19def
--- /dev/null
+++ b/fs/ksmbd/connection.c
@@ -0,0 +1,409 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2016 Namjae Jeon <namjae.jeon@xxxxxxxxxxxxxxxxxxx>
+ * Copyright (C) 2018 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/mutex.h>
+#include <linux/freezer.h>
+#include <linux/module.h>
+
+#include "server.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);
+
+ kvfree(conn->request_buf);
+ 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);
+ ida_init(&conn->async_ida);
+
+ 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 = work->response_buf;
+ size_t len = 0;
+ int sent;
+ struct kvec iov[3];
+ int iov_idx = 0;
+
+ ksmbd_conn_try_dequeue_request(work);
+ if (!rsp_hdr) {
+ pr_err("NULL response header\n");
+ return -EINVAL;
+ }
+
+ if (work->tr_buf) {
+ iov[iov_idx] = (struct kvec) { work->tr_buf,
+ sizeof(struct smb2_transform_hdr) };
+ len += iov[iov_idx++].iov_len;
+ }
+
+ if (work->aux_payload_sz) {
+ iov[iov_idx] = (struct kvec) { rsp_hdr, work->resp_hdr_sz };
+ len += iov[iov_idx++].iov_len;
+ iov[iov_idx] = (struct kvec) { work->aux_payload_buf, work->aux_payload_sz };
+ len += iov[iov_idx++].iov_len;
+ } else {
+ if (work->tr_buf)
+ iov[iov_idx].iov_len = work->resp_hdr_sz;
+ 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) {
+ pr_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;
+
+ kvfree(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 = kvmalloc(size, GFP_KERNEL);
+ 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) {
+ pr_err("sock_read failed: %d\n", size);
+ break;
+ }
+
+ if (size != pdu_size) {
+ pr_err("PDU error. Read: %d, Expected: %d\n",
+ size, pdu_size);
+ continue;
+ }
+
+ if (!default_conn_ops.process_fn) {
+ pr_err("No connection request callback\n");
+ break;
+ }
+
+ if (default_conn_ops.process_fn(conn)) {
+ pr_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);
+}
diff --git a/fs/ksmbd/connection.h b/fs/ksmbd/connection.h
new file mode 100644
index 000000000000..98108b41f739
--- /dev/null
+++ b/fs/ksmbd/connection.h
@@ -0,0 +1,205 @@
+/* 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 ida async_ida;
+
+ __le16 cipher_type;
+ __le16 compress_algorithm;
+ bool posix_ext_supported;
+ bool binding;
+};
+
+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__ */
diff --git a/fs/ksmbd/transport_tcp.c b/fs/ksmbd/transport_tcp.c
new file mode 100644
index 000000000000..56ec11ff5a9f
--- /dev/null
+++ b/fs/ksmbd/transport_tcp.c
@@ -0,0 +1,619 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2016 Namjae Jeon <linkinjeon@xxxxxxxxxx>
+ * Copyright (C) 2018 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/freezer.h>
+
+#include "smb_common.h"
+#include "server.h"
+#include "auth.h"
+#include "connection.h"
+#include "transport_tcp.h"
+
+#define IFACE_STATE_DOWN BIT(0)
+#define IFACE_STATE_CONFIGURED BIT(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
+ * @client_sk: 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) {
+ pr_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)) {
+ pr_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_tcp_run_kthread() - start forker thread
+ * @iface: pointer to struct interface
+ *
+ * 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)
+ pr_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) {
+ pr_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) {
+ pr_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) {
+ pr_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) {
+ pr_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) {
+ pr_err("Port listen() error: %d\n", ret);
+ goto out_error;
+ }
+
+ iface->ksmbd_socket = ksmbd_socket;
+ ret = ksmbd_tcp_run_kthread(iface);
+ if (ret) {
+ pr_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)
+ pr_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);
+ kfree(iface);
+ }
+}
+
+static struct interface *alloc_iface(char *ifname)
+{
+ struct interface *iface;
+
+ if (!ifname)
+ return NULL;
+
+ iface = kzalloc(sizeof(struct interface), GFP_KERNEL);
+ 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,
+};
diff --git a/fs/ksmbd/transport_tcp.h b/fs/ksmbd/transport_tcp.h
new file mode 100644
index 000000000000..e338bebe322f
--- /dev/null
+++ b/fs/ksmbd/transport_tcp.h
@@ -0,0 +1,13 @@
+/* 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__ */
--
2.17.1