diff options
Diffstat (limited to 'fs/smb/server/transport_tcp.c')
| -rw-r--r-- | fs/smb/server/transport_tcp.c | 649 |
1 files changed, 649 insertions, 0 deletions
diff --git a/fs/smb/server/transport_tcp.c b/fs/smb/server/transport_tcp.c new file mode 100644 index 000000000000..eff7a1d793f0 --- /dev/null +++ b/fs/smb/server/transport_tcp.c @@ -0,0 +1,649 @@ +// 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; + + 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; + } + + 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: 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, +}; |