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-rw-r--r--fs/smb/server/transport_tcp.c650
1 files changed, 650 insertions, 0 deletions
diff --git a/fs/smb/server/transport_tcp.c b/fs/smb/server/transport_tcp.c
new file mode 100644
index 000000000..9d4222154
--- /dev/null
+++ b/fs/smb/server/transport_tcp.c
@@ -0,0 +1,650 @@
+// 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)
+
+static atomic_t active_num_conn;
+
+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;
+ struct task_struct *handler;
+
+ t = alloc_transport(client_sk);
+ if (!t) {
+ sock_release(client_sk);
+ 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;
+ }
+
+ handler = kthread_run(ksmbd_conn_handler_loop,
+ KSMBD_TRANS(t)->conn,
+ "ksmbd:%u",
+ ksmbd_tcp_get_port(csin));
+ if (IS_ERR(handler)) {
+ pr_err("cannot start conn thread\n");
+ rc = PTR_ERR(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: 0 on success, error number otherwise
+ */
+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,
+ SOCK_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;
+ }
+
+ if (server_conf.max_connections &&
+ atomic_inc_return(&active_num_conn) >= server_conf.max_connections) {
+ pr_info_ratelimited("Limit the maximum number of connections(%u)\n",
+ atomic_read(&active_num_conn));
+ atomic_dec(&active_num_conn);
+ sock_release(client_sk);
+ 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
+ * @max_retries: maximum retry count
+ *
+ * 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 max_retries)
+{
+ 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 (ksmbd_conn_need_reconnect(conn)) {
+ total_read = -EAGAIN;
+ break;
+ } else if (length == -ERESTARTSYS || length == -EAGAIN) {
+ /*
+ * If max_retries is negative, Allow unlimited
+ * retries to keep connection with inactive sessions.
+ */
+ if (max_retries == 0) {
+ total_read = length;
+ break;
+ } else if (max_retries > 0) {
+ max_retries--;
+ }
+
+ usleep_range(1000, 2000);
+ length = 0;
+ continue;
+ } else if (length <= 0) {
+ total_read = length;
+ 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, int max_retries)
+{
+ struct kvec iov;
+
+ iov.iov_base = buf;
+ iov.iov_len = to_read;
+
+ return ksmbd_tcp_readv(TCP_TRANS(t), &iov, 1, to_read, max_retries);
+}
+
+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));
+ if (server_conf.max_connections)
+ atomic_dec(&active_num_conn);
+}
+
+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);
+ sock_release(ksmbd_socket);
+}
+
+/**
+ * create_socket - create socket for ksmbd/0
+ *
+ * Return: 0 on success, error number otherwise
+ */
+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) {
+ if (ret != -EAFNOSUPPORT)
+ pr_err("Can't create socket for ipv6, fallback to 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_clear;
+ }
+
+ 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);
+out_clear:
+ 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 (netif_is_bridge_port(netdev))
+ 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 (netif_is_bridge_port(netdev))
+ 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,
+};