xref: /linux/fs/smb/server/transport_tcp.c (revision eb4a0992ddae04ad5b402029a430b2fa06c81647)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *   Copyright (C) 2016 Namjae Jeon <linkinjeon@kernel.org>
4  *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
5  */
6 
7 #include <linux/freezer.h>
8 
9 #include "smb_common.h"
10 #include "server.h"
11 #include "auth.h"
12 #include "connection.h"
13 #include "transport_tcp.h"
14 
15 #define IFACE_STATE_DOWN		BIT(0)
16 #define IFACE_STATE_CONFIGURED		BIT(1)
17 
18 static atomic_t active_num_conn;
19 
20 struct interface {
21 	struct task_struct	*ksmbd_kthread;
22 	struct socket		*ksmbd_socket;
23 	struct list_head	entry;
24 	char			*name;
25 	struct mutex		sock_release_lock;
26 	int			state;
27 };
28 
29 static LIST_HEAD(iface_list);
30 
31 static int bind_additional_ifaces;
32 
33 struct tcp_transport {
34 	struct ksmbd_transport		transport;
35 	struct socket			*sock;
36 	struct kvec			*iov;
37 	unsigned int			nr_iov;
38 };
39 
40 static const struct ksmbd_transport_ops ksmbd_tcp_transport_ops;
41 
42 static void tcp_stop_kthread(struct task_struct *kthread);
43 static struct interface *alloc_iface(char *ifname);
44 
45 #define KSMBD_TRANS(t)	(&(t)->transport)
46 #define TCP_TRANS(t)	((struct tcp_transport *)container_of(t, \
47 				struct tcp_transport, transport))
48 
ksmbd_tcp_nodelay(struct socket * sock)49 static inline void ksmbd_tcp_nodelay(struct socket *sock)
50 {
51 	tcp_sock_set_nodelay(sock->sk);
52 }
53 
ksmbd_tcp_reuseaddr(struct socket * sock)54 static inline void ksmbd_tcp_reuseaddr(struct socket *sock)
55 {
56 	sock_set_reuseaddr(sock->sk);
57 }
58 
ksmbd_tcp_rcv_timeout(struct socket * sock,s64 secs)59 static inline void ksmbd_tcp_rcv_timeout(struct socket *sock, s64 secs)
60 {
61 	if (secs && secs < MAX_SCHEDULE_TIMEOUT / HZ - 1)
62 		WRITE_ONCE(sock->sk->sk_rcvtimeo, secs * HZ);
63 	else
64 		WRITE_ONCE(sock->sk->sk_rcvtimeo, MAX_SCHEDULE_TIMEOUT);
65 }
66 
ksmbd_tcp_snd_timeout(struct socket * sock,s64 secs)67 static inline void ksmbd_tcp_snd_timeout(struct socket *sock, s64 secs)
68 {
69 	sock_set_sndtimeo(sock->sk, secs);
70 }
71 
alloc_transport(struct socket * client_sk)72 static struct tcp_transport *alloc_transport(struct socket *client_sk)
73 {
74 	struct tcp_transport *t;
75 	struct ksmbd_conn *conn;
76 
77 	t = kzalloc(sizeof(*t), KSMBD_DEFAULT_GFP);
78 	if (!t)
79 		return NULL;
80 	t->sock = client_sk;
81 
82 	conn = ksmbd_conn_alloc();
83 	if (!conn) {
84 		kfree(t);
85 		return NULL;
86 	}
87 
88 #if IS_ENABLED(CONFIG_IPV6)
89 	if (client_sk->sk->sk_family == AF_INET6)
90 		memcpy(&conn->inet6_addr, &client_sk->sk->sk_v6_daddr, 16);
91 	else
92 		conn->inet_addr = inet_sk(client_sk->sk)->inet_daddr;
93 #else
94 	conn->inet_addr = inet_sk(client_sk->sk)->inet_daddr;
95 #endif
96 	conn->transport = KSMBD_TRANS(t);
97 	KSMBD_TRANS(t)->conn = conn;
98 	KSMBD_TRANS(t)->ops = &ksmbd_tcp_transport_ops;
99 	return t;
100 }
101 
ksmbd_tcp_free_transport(struct ksmbd_transport * kt)102 static void ksmbd_tcp_free_transport(struct ksmbd_transport *kt)
103 {
104 	struct tcp_transport *t = TCP_TRANS(kt);
105 
106 	sock_release(t->sock);
107 	kfree(t->iov);
108 	kfree(t);
109 }
110 
free_transport(struct tcp_transport * t)111 static void free_transport(struct tcp_transport *t)
112 {
113 	kernel_sock_shutdown(t->sock, SHUT_RDWR);
114 	ksmbd_conn_free(KSMBD_TRANS(t)->conn);
115 }
116 
117 /**
118  * kvec_array_init() - initialize a IO vector segment
119  * @new:	IO vector to be initialized
120  * @iov:	base IO vector
121  * @nr_segs:	number of segments in base iov
122  * @bytes:	total iovec length so far for read
123  *
124  * Return:	Number of IO segments
125  */
kvec_array_init(struct kvec * new,struct kvec * iov,unsigned int nr_segs,size_t bytes)126 static unsigned int kvec_array_init(struct kvec *new, struct kvec *iov,
127 				    unsigned int nr_segs, size_t bytes)
128 {
129 	size_t base = 0;
130 
131 	while (bytes || !iov->iov_len) {
132 		int copy = min(bytes, iov->iov_len);
133 
134 		bytes -= copy;
135 		base += copy;
136 		if (iov->iov_len == base) {
137 			iov++;
138 			nr_segs--;
139 			base = 0;
140 		}
141 	}
142 
143 	memcpy(new, iov, sizeof(*iov) * nr_segs);
144 	new->iov_base += base;
145 	new->iov_len -= base;
146 	return nr_segs;
147 }
148 
149 /**
150  * get_conn_iovec() - get connection iovec for reading from socket
151  * @t:		TCP transport instance
152  * @nr_segs:	number of segments in iov
153  *
154  * Return:	return existing or newly allocate iovec
155  */
get_conn_iovec(struct tcp_transport * t,unsigned int nr_segs)156 static struct kvec *get_conn_iovec(struct tcp_transport *t, unsigned int nr_segs)
157 {
158 	struct kvec *new_iov;
159 
160 	if (t->iov && nr_segs <= t->nr_iov)
161 		return t->iov;
162 
163 	/* not big enough -- allocate a new one and release the old */
164 	new_iov = kmalloc_array(nr_segs, sizeof(*new_iov), KSMBD_DEFAULT_GFP);
165 	if (new_iov) {
166 		kfree(t->iov);
167 		t->iov = new_iov;
168 		t->nr_iov = nr_segs;
169 	}
170 	return new_iov;
171 }
172 
ksmbd_tcp_get_port(const struct sockaddr * sa)173 static unsigned short ksmbd_tcp_get_port(const struct sockaddr *sa)
174 {
175 	switch (sa->sa_family) {
176 	case AF_INET:
177 		return ntohs(((struct sockaddr_in *)sa)->sin_port);
178 	case AF_INET6:
179 		return ntohs(((struct sockaddr_in6 *)sa)->sin6_port);
180 	}
181 	return 0;
182 }
183 
184 /**
185  * ksmbd_tcp_new_connection() - create a new tcp session on mount
186  * @client_sk:	socket associated with new connection
187  *
188  * whenever a new connection is requested, create a conn thread
189  * (session thread) to handle new incoming smb requests from the connection
190  *
191  * Return:	0 on success, otherwise error
192  */
ksmbd_tcp_new_connection(struct socket * client_sk)193 static int ksmbd_tcp_new_connection(struct socket *client_sk)
194 {
195 	struct sockaddr *csin;
196 	int rc = 0;
197 	struct tcp_transport *t;
198 	struct task_struct *handler;
199 
200 	t = alloc_transport(client_sk);
201 	if (!t) {
202 		sock_release(client_sk);
203 		return -ENOMEM;
204 	}
205 
206 	csin = KSMBD_TCP_PEER_SOCKADDR(KSMBD_TRANS(t)->conn);
207 	if (kernel_getpeername(client_sk, csin) < 0) {
208 		pr_err("client ip resolution failed\n");
209 		rc = -EINVAL;
210 		goto out_error;
211 	}
212 
213 	handler = kthread_run(ksmbd_conn_handler_loop,
214 			      KSMBD_TRANS(t)->conn,
215 			      "ksmbd:%u",
216 			      ksmbd_tcp_get_port(csin));
217 	if (IS_ERR(handler)) {
218 		pr_err("cannot start conn thread\n");
219 		rc = PTR_ERR(handler);
220 		free_transport(t);
221 	}
222 	return rc;
223 
224 out_error:
225 	free_transport(t);
226 	return rc;
227 }
228 
229 /**
230  * ksmbd_kthread_fn() - listen to new SMB connections and callback server
231  * @p:		arguments to forker thread
232  *
233  * Return:	0 on success, error number otherwise
234  */
ksmbd_kthread_fn(void * p)235 static int ksmbd_kthread_fn(void *p)
236 {
237 	struct socket *client_sk = NULL;
238 	struct interface *iface = (struct interface *)p;
239 	struct ksmbd_conn *conn;
240 	int ret;
241 
242 	while (!kthread_should_stop()) {
243 		mutex_lock(&iface->sock_release_lock);
244 		if (!iface->ksmbd_socket) {
245 			mutex_unlock(&iface->sock_release_lock);
246 			break;
247 		}
248 		ret = kernel_accept(iface->ksmbd_socket, &client_sk,
249 				    SOCK_NONBLOCK);
250 		mutex_unlock(&iface->sock_release_lock);
251 		if (ret) {
252 			if (ret == -EAGAIN)
253 				/* check for new connections every 100 msecs */
254 				schedule_timeout_interruptible(HZ / 10);
255 			continue;
256 		}
257 
258 		/*
259 		 * Limits repeated connections from clients with the same IP.
260 		 */
261 		down_read(&conn_list_lock);
262 		list_for_each_entry(conn, &conn_list, conns_list)
263 #if IS_ENABLED(CONFIG_IPV6)
264 			if (client_sk->sk->sk_family == AF_INET6) {
265 				if (memcmp(&client_sk->sk->sk_v6_daddr,
266 					   &conn->inet6_addr, 16) == 0) {
267 					ret = -EAGAIN;
268 					break;
269 				}
270 			} else if (inet_sk(client_sk->sk)->inet_daddr ==
271 				 conn->inet_addr) {
272 				ret = -EAGAIN;
273 				break;
274 			}
275 #else
276 			if (inet_sk(client_sk->sk)->inet_daddr ==
277 			    conn->inet_addr) {
278 				ret = -EAGAIN;
279 				break;
280 			}
281 #endif
282 		up_read(&conn_list_lock);
283 		if (ret == -EAGAIN)
284 			continue;
285 
286 		if (server_conf.max_connections &&
287 		    atomic_inc_return(&active_num_conn) >= server_conf.max_connections) {
288 			pr_info_ratelimited("Limit the maximum number of connections(%u)\n",
289 					    atomic_read(&active_num_conn));
290 			atomic_dec(&active_num_conn);
291 			sock_release(client_sk);
292 			continue;
293 		}
294 
295 		ksmbd_debug(CONN, "connect success: accepted new connection\n");
296 		client_sk->sk->sk_rcvtimeo = KSMBD_TCP_RECV_TIMEOUT;
297 		client_sk->sk->sk_sndtimeo = KSMBD_TCP_SEND_TIMEOUT;
298 
299 		ksmbd_tcp_new_connection(client_sk);
300 	}
301 
302 	ksmbd_debug(CONN, "releasing socket\n");
303 	return 0;
304 }
305 
306 /**
307  * ksmbd_tcp_run_kthread() - start forker thread
308  * @iface: pointer to struct interface
309  *
310  * start forker thread(ksmbd/0) at module init time to listen
311  * on port 445 for new SMB connection requests. It creates per connection
312  * server threads(ksmbd/x)
313  *
314  * Return:	0 on success or error number
315  */
ksmbd_tcp_run_kthread(struct interface * iface)316 static int ksmbd_tcp_run_kthread(struct interface *iface)
317 {
318 	int rc;
319 	struct task_struct *kthread;
320 
321 	kthread = kthread_run(ksmbd_kthread_fn, (void *)iface, "ksmbd-%s",
322 			      iface->name);
323 	if (IS_ERR(kthread)) {
324 		rc = PTR_ERR(kthread);
325 		return rc;
326 	}
327 	iface->ksmbd_kthread = kthread;
328 
329 	return 0;
330 }
331 
332 /**
333  * ksmbd_tcp_readv() - read data from socket in given iovec
334  * @t:			TCP transport instance
335  * @iov_orig:		base IO vector
336  * @nr_segs:		number of segments in base iov
337  * @to_read:		number of bytes to read from socket
338  * @max_retries:	maximum retry count
339  *
340  * Return:	on success return number of bytes read from socket,
341  *		otherwise return error number
342  */
ksmbd_tcp_readv(struct tcp_transport * t,struct kvec * iov_orig,unsigned int nr_segs,unsigned int to_read,int max_retries)343 static int ksmbd_tcp_readv(struct tcp_transport *t, struct kvec *iov_orig,
344 			   unsigned int nr_segs, unsigned int to_read,
345 			   int max_retries)
346 {
347 	int length = 0;
348 	int total_read;
349 	unsigned int segs;
350 	struct msghdr ksmbd_msg;
351 	struct kvec *iov;
352 	struct ksmbd_conn *conn = KSMBD_TRANS(t)->conn;
353 
354 	iov = get_conn_iovec(t, nr_segs);
355 	if (!iov)
356 		return -ENOMEM;
357 
358 	ksmbd_msg.msg_control = NULL;
359 	ksmbd_msg.msg_controllen = 0;
360 
361 	for (total_read = 0; to_read; total_read += length, to_read -= length) {
362 		try_to_freeze();
363 
364 		if (!ksmbd_conn_alive(conn)) {
365 			total_read = -ESHUTDOWN;
366 			break;
367 		}
368 		segs = kvec_array_init(iov, iov_orig, nr_segs, total_read);
369 
370 		length = kernel_recvmsg(t->sock, &ksmbd_msg,
371 					iov, segs, to_read, 0);
372 
373 		if (length == -EINTR) {
374 			total_read = -ESHUTDOWN;
375 			break;
376 		} else if (ksmbd_conn_need_reconnect(conn)) {
377 			total_read = -EAGAIN;
378 			break;
379 		} else if (length == -ERESTARTSYS || length == -EAGAIN) {
380 			/*
381 			 * If max_retries is negative, Allow unlimited
382 			 * retries to keep connection with inactive sessions.
383 			 */
384 			if (max_retries == 0) {
385 				total_read = length;
386 				break;
387 			} else if (max_retries > 0) {
388 				max_retries--;
389 			}
390 
391 			usleep_range(1000, 2000);
392 			length = 0;
393 			continue;
394 		} else if (length <= 0) {
395 			total_read = length;
396 			break;
397 		}
398 	}
399 	return total_read;
400 }
401 
402 /**
403  * ksmbd_tcp_read() - read data from socket in given buffer
404  * @t:		TCP transport instance
405  * @buf:	buffer to store read data from socket
406  * @to_read:	number of bytes to read from socket
407  * @max_retries: number of retries if reading from socket fails
408  *
409  * Return:	on success return number of bytes read from socket,
410  *		otherwise return error number
411  */
ksmbd_tcp_read(struct ksmbd_transport * t,char * buf,unsigned int to_read,int max_retries)412 static int ksmbd_tcp_read(struct ksmbd_transport *t, char *buf,
413 			  unsigned int to_read, int max_retries)
414 {
415 	struct kvec iov;
416 
417 	iov.iov_base = buf;
418 	iov.iov_len = to_read;
419 
420 	return ksmbd_tcp_readv(TCP_TRANS(t), &iov, 1, to_read, max_retries);
421 }
422 
ksmbd_tcp_writev(struct ksmbd_transport * t,struct kvec * iov,int nvecs,int size,bool need_invalidate,unsigned int remote_key)423 static int ksmbd_tcp_writev(struct ksmbd_transport *t, struct kvec *iov,
424 			    int nvecs, int size, bool need_invalidate,
425 			    unsigned int remote_key)
426 
427 {
428 	struct msghdr smb_msg = {.msg_flags = MSG_NOSIGNAL};
429 
430 	return kernel_sendmsg(TCP_TRANS(t)->sock, &smb_msg, iov, nvecs, size);
431 }
432 
ksmbd_tcp_disconnect(struct ksmbd_transport * t)433 static void ksmbd_tcp_disconnect(struct ksmbd_transport *t)
434 {
435 	free_transport(TCP_TRANS(t));
436 	if (server_conf.max_connections)
437 		atomic_dec(&active_num_conn);
438 }
439 
tcp_destroy_socket(struct socket * ksmbd_socket)440 static void tcp_destroy_socket(struct socket *ksmbd_socket)
441 {
442 	int ret;
443 
444 	if (!ksmbd_socket)
445 		return;
446 
447 	/* set zero to timeout */
448 	ksmbd_tcp_rcv_timeout(ksmbd_socket, 0);
449 	ksmbd_tcp_snd_timeout(ksmbd_socket, 0);
450 
451 	ret = kernel_sock_shutdown(ksmbd_socket, SHUT_RDWR);
452 	if (ret)
453 		pr_err("Failed to shutdown socket: %d\n", ret);
454 	sock_release(ksmbd_socket);
455 }
456 
457 /**
458  * create_socket - create socket for ksmbd/0
459  * @iface:      interface to bind the created socket to
460  *
461  * Return:	0 on success, error number otherwise
462  */
create_socket(struct interface * iface)463 static int create_socket(struct interface *iface)
464 {
465 	int ret;
466 	struct sockaddr_in6 sin6;
467 	struct sockaddr_in sin;
468 	struct socket *ksmbd_socket;
469 	bool ipv4 = false;
470 
471 	ret = sock_create(PF_INET6, SOCK_STREAM, IPPROTO_TCP, &ksmbd_socket);
472 	if (ret) {
473 		if (ret != -EAFNOSUPPORT)
474 			pr_err("Can't create socket for ipv6, fallback to ipv4: %d\n", ret);
475 		ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP,
476 				  &ksmbd_socket);
477 		if (ret) {
478 			pr_err("Can't create socket for ipv4: %d\n", ret);
479 			goto out_clear;
480 		}
481 
482 		sin.sin_family = PF_INET;
483 		sin.sin_addr.s_addr = htonl(INADDR_ANY);
484 		sin.sin_port = htons(server_conf.tcp_port);
485 		ipv4 = true;
486 	} else {
487 		sin6.sin6_family = PF_INET6;
488 		sin6.sin6_addr = in6addr_any;
489 		sin6.sin6_port = htons(server_conf.tcp_port);
490 
491 		lock_sock(ksmbd_socket->sk);
492 		ksmbd_socket->sk->sk_ipv6only = false;
493 		release_sock(ksmbd_socket->sk);
494 	}
495 
496 	ksmbd_tcp_nodelay(ksmbd_socket);
497 	ksmbd_tcp_reuseaddr(ksmbd_socket);
498 
499 	ret = sock_setsockopt(ksmbd_socket,
500 			      SOL_SOCKET,
501 			      SO_BINDTODEVICE,
502 			      KERNEL_SOCKPTR(iface->name),
503 			      strlen(iface->name));
504 	if (ret != -ENODEV && ret < 0) {
505 		pr_err("Failed to set SO_BINDTODEVICE: %d\n", ret);
506 		goto out_error;
507 	}
508 
509 	if (ipv4)
510 		ret = kernel_bind(ksmbd_socket, (struct sockaddr *)&sin,
511 				  sizeof(sin));
512 	else
513 		ret = kernel_bind(ksmbd_socket, (struct sockaddr *)&sin6,
514 				  sizeof(sin6));
515 	if (ret) {
516 		pr_err("Failed to bind socket: %d\n", ret);
517 		goto out_error;
518 	}
519 
520 	ksmbd_socket->sk->sk_rcvtimeo = KSMBD_TCP_RECV_TIMEOUT;
521 	ksmbd_socket->sk->sk_sndtimeo = KSMBD_TCP_SEND_TIMEOUT;
522 
523 	ret = kernel_listen(ksmbd_socket, KSMBD_SOCKET_BACKLOG);
524 	if (ret) {
525 		pr_err("Port listen() error: %d\n", ret);
526 		goto out_error;
527 	}
528 
529 	iface->ksmbd_socket = ksmbd_socket;
530 	ret = ksmbd_tcp_run_kthread(iface);
531 	if (ret) {
532 		pr_err("Can't start ksmbd main kthread: %d\n", ret);
533 		goto out_error;
534 	}
535 	iface->state = IFACE_STATE_CONFIGURED;
536 
537 	return 0;
538 
539 out_error:
540 	tcp_destroy_socket(ksmbd_socket);
541 out_clear:
542 	iface->ksmbd_socket = NULL;
543 	return ret;
544 }
545 
ksmbd_find_netdev_name_iface_list(char * netdev_name)546 struct interface *ksmbd_find_netdev_name_iface_list(char *netdev_name)
547 {
548 	struct interface *iface;
549 
550 	list_for_each_entry(iface, &iface_list, entry)
551 		if (!strcmp(iface->name, netdev_name))
552 			return iface;
553 	return NULL;
554 }
555 
ksmbd_netdev_event(struct notifier_block * nb,unsigned long event,void * ptr)556 static int ksmbd_netdev_event(struct notifier_block *nb, unsigned long event,
557 			      void *ptr)
558 {
559 	struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
560 	struct interface *iface;
561 	int ret;
562 
563 	switch (event) {
564 	case NETDEV_UP:
565 		if (netif_is_bridge_port(netdev))
566 			return NOTIFY_OK;
567 
568 		iface = ksmbd_find_netdev_name_iface_list(netdev->name);
569 		if (iface && iface->state == IFACE_STATE_DOWN) {
570 			ksmbd_debug(CONN, "netdev-up event: netdev(%s) is going up\n",
571 					iface->name);
572 			ret = create_socket(iface);
573 			if (ret)
574 				return NOTIFY_OK;
575 		}
576 		if (!iface && bind_additional_ifaces) {
577 			iface = alloc_iface(kstrdup(netdev->name, KSMBD_DEFAULT_GFP));
578 			if (!iface)
579 				return NOTIFY_OK;
580 			ksmbd_debug(CONN, "netdev-up event: netdev(%s) is going up\n",
581 				    iface->name);
582 			ret = create_socket(iface);
583 			if (ret)
584 				break;
585 		}
586 		break;
587 	case NETDEV_DOWN:
588 		iface = ksmbd_find_netdev_name_iface_list(netdev->name);
589 		if (iface && iface->state == IFACE_STATE_CONFIGURED) {
590 			ksmbd_debug(CONN, "netdev-down event: netdev(%s) is going down\n",
591 					iface->name);
592 			tcp_stop_kthread(iface->ksmbd_kthread);
593 			iface->ksmbd_kthread = NULL;
594 			mutex_lock(&iface->sock_release_lock);
595 			tcp_destroy_socket(iface->ksmbd_socket);
596 			iface->ksmbd_socket = NULL;
597 			mutex_unlock(&iface->sock_release_lock);
598 
599 			iface->state = IFACE_STATE_DOWN;
600 			break;
601 		}
602 		break;
603 	}
604 
605 	return NOTIFY_DONE;
606 }
607 
608 static struct notifier_block ksmbd_netdev_notifier = {
609 	.notifier_call = ksmbd_netdev_event,
610 };
611 
ksmbd_tcp_init(void)612 int ksmbd_tcp_init(void)
613 {
614 	register_netdevice_notifier(&ksmbd_netdev_notifier);
615 
616 	return 0;
617 }
618 
tcp_stop_kthread(struct task_struct * kthread)619 static void tcp_stop_kthread(struct task_struct *kthread)
620 {
621 	int ret;
622 
623 	if (!kthread)
624 		return;
625 
626 	ret = kthread_stop(kthread);
627 	if (ret)
628 		pr_err("failed to stop forker thread\n");
629 }
630 
ksmbd_tcp_destroy(void)631 void ksmbd_tcp_destroy(void)
632 {
633 	struct interface *iface, *tmp;
634 
635 	unregister_netdevice_notifier(&ksmbd_netdev_notifier);
636 
637 	list_for_each_entry_safe(iface, tmp, &iface_list, entry) {
638 		list_del(&iface->entry);
639 		kfree(iface->name);
640 		kfree(iface);
641 	}
642 }
643 
alloc_iface(char * ifname)644 static struct interface *alloc_iface(char *ifname)
645 {
646 	struct interface *iface;
647 
648 	if (!ifname)
649 		return NULL;
650 
651 	iface = kzalloc(sizeof(struct interface), KSMBD_DEFAULT_GFP);
652 	if (!iface) {
653 		kfree(ifname);
654 		return NULL;
655 	}
656 
657 	iface->name = ifname;
658 	iface->state = IFACE_STATE_DOWN;
659 	list_add(&iface->entry, &iface_list);
660 	mutex_init(&iface->sock_release_lock);
661 	return iface;
662 }
663 
ksmbd_tcp_set_interfaces(char * ifc_list,int ifc_list_sz)664 int ksmbd_tcp_set_interfaces(char *ifc_list, int ifc_list_sz)
665 {
666 	int sz = 0;
667 
668 	if (!ifc_list_sz) {
669 		bind_additional_ifaces = 1;
670 		return 0;
671 	}
672 
673 	while (ifc_list_sz > 0) {
674 		if (!alloc_iface(kstrdup(ifc_list, KSMBD_DEFAULT_GFP)))
675 			return -ENOMEM;
676 
677 		sz = strlen(ifc_list);
678 		if (!sz)
679 			break;
680 
681 		ifc_list += sz + 1;
682 		ifc_list_sz -= (sz + 1);
683 	}
684 
685 	bind_additional_ifaces = 0;
686 
687 	return 0;
688 }
689 
690 static const struct ksmbd_transport_ops ksmbd_tcp_transport_ops = {
691 	.read		= ksmbd_tcp_read,
692 	.writev		= ksmbd_tcp_writev,
693 	.disconnect	= ksmbd_tcp_disconnect,
694 	.free_transport = ksmbd_tcp_free_transport,
695 };
696