1 files changed, 619 insertions, 0 deletions

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@kernel.org>
+ *   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,
+};