xref: /linux/fs/smb/server/transport_tcp.c (revision b3fee71e6673393d04476fbe0f4f03f97765e32d)
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 		conn->inet_hash = ipv6_addr_hash(&client_sk->sk->sk_v6_daddr);
92 	} else {
93 		conn->inet_addr = inet_sk(client_sk->sk)->inet_daddr;
94 		conn->inet_hash = ipv4_addr_hash(inet_sk(client_sk->sk)->inet_daddr);
95 	}
96 #else
97 	conn->inet_addr = inet_sk(client_sk->sk)->inet_daddr;
98 	conn->inet_hash = ipv4_addr_hash(inet_sk(client_sk->sk)->inet_daddr);
99 #endif
100 	down_write(&conn_list_lock);
101 	hash_add(conn_list, &conn->hlist, conn->inet_hash);
102 	up_write(&conn_list_lock);
103 
104 	conn->transport = KSMBD_TRANS(t);
105 	KSMBD_TRANS(t)->conn = conn;
106 	KSMBD_TRANS(t)->ops = &ksmbd_tcp_transport_ops;
107 	return t;
108 }
109 
ksmbd_tcp_free_transport(struct ksmbd_transport * kt)110 static void ksmbd_tcp_free_transport(struct ksmbd_transport *kt)
111 {
112 	struct tcp_transport *t = TCP_TRANS(kt);
113 
114 	sock_release(t->sock);
115 	kfree(t->iov);
116 	kfree(t);
117 }
118 
free_transport(struct tcp_transport * t)119 static void free_transport(struct tcp_transport *t)
120 {
121 	kernel_sock_shutdown(t->sock, SHUT_RDWR);
122 	ksmbd_conn_free(KSMBD_TRANS(t)->conn);
123 }
124 
125 /**
126  * kvec_array_init() - initialize a IO vector segment
127  * @new:	IO vector to be initialized
128  * @iov:	base IO vector
129  * @nr_segs:	number of segments in base iov
130  * @bytes:	total iovec length so far for read
131  *
132  * Return:	Number of IO segments
133  */
kvec_array_init(struct kvec * new,struct kvec * iov,unsigned int nr_segs,size_t bytes)134 static unsigned int kvec_array_init(struct kvec *new, struct kvec *iov,
135 				    unsigned int nr_segs, size_t bytes)
136 {
137 	size_t base = 0;
138 
139 	while (bytes || !iov->iov_len) {
140 		int copy = min(bytes, iov->iov_len);
141 
142 		bytes -= copy;
143 		base += copy;
144 		if (iov->iov_len == base) {
145 			iov++;
146 			nr_segs--;
147 			base = 0;
148 		}
149 	}
150 
151 	memcpy(new, iov, sizeof(*iov) * nr_segs);
152 	new->iov_base += base;
153 	new->iov_len -= base;
154 	return nr_segs;
155 }
156 
157 /**
158  * get_conn_iovec() - get connection iovec for reading from socket
159  * @t:		TCP transport instance
160  * @nr_segs:	number of segments in iov
161  *
162  * Return:	return existing or newly allocate iovec
163  */
get_conn_iovec(struct tcp_transport * t,unsigned int nr_segs)164 static struct kvec *get_conn_iovec(struct tcp_transport *t, unsigned int nr_segs)
165 {
166 	struct kvec *new_iov;
167 
168 	if (t->iov && nr_segs <= t->nr_iov)
169 		return t->iov;
170 
171 	/* not big enough -- allocate a new one and release the old */
172 	new_iov = kmalloc_array(nr_segs, sizeof(*new_iov), KSMBD_DEFAULT_GFP);
173 	if (new_iov) {
174 		kfree(t->iov);
175 		t->iov = new_iov;
176 		t->nr_iov = nr_segs;
177 	}
178 	return new_iov;
179 }
180 
181 /**
182  * ksmbd_tcp_new_connection() - create a new tcp session on mount
183  * @client_sk:	socket associated with new connection
184  *
185  * whenever a new connection is requested, create a conn thread
186  * (session thread) to handle new incoming smb requests from the connection
187  *
188  * Return:	0 on success, otherwise error
189  */
ksmbd_tcp_new_connection(struct socket * client_sk)190 static int ksmbd_tcp_new_connection(struct socket *client_sk)
191 {
192 	int rc = 0;
193 	struct tcp_transport *t;
194 	struct task_struct *handler;
195 
196 	t = alloc_transport(client_sk);
197 	if (!t) {
198 		sock_release(client_sk);
199 		return -ENOMEM;
200 	}
201 
202 #if IS_ENABLED(CONFIG_IPV6)
203 	if (client_sk->sk->sk_family == AF_INET6)
204 		handler = kthread_run(ksmbd_conn_handler_loop,
205 				KSMBD_TRANS(t)->conn, "ksmbd:%pI6c",
206 				&KSMBD_TRANS(t)->conn->inet6_addr);
207 	else
208 		handler = kthread_run(ksmbd_conn_handler_loop,
209 				KSMBD_TRANS(t)->conn, "ksmbd:%pI4",
210 				&KSMBD_TRANS(t)->conn->inet_addr);
211 #else
212 	handler = kthread_run(ksmbd_conn_handler_loop,
213 			KSMBD_TRANS(t)->conn, "ksmbd:%pI4",
214 			&KSMBD_TRANS(t)->conn->inet_addr);
215 #endif
216 	if (IS_ERR(handler)) {
217 		pr_err("cannot start conn thread\n");
218 		rc = PTR_ERR(handler);
219 		free_transport(t);
220 	}
221 	return rc;
222 }
223 
224 /**
225  * ksmbd_kthread_fn() - listen to new SMB connections and callback server
226  * @p:		arguments to forker thread
227  *
228  * Return:	0 on success, error number otherwise
229  */
ksmbd_kthread_fn(void * p)230 static int ksmbd_kthread_fn(void *p)
231 {
232 	struct socket *client_sk = NULL;
233 	struct interface *iface = (struct interface *)p;
234 	struct ksmbd_conn *conn;
235 	int ret, inet_hash;
236 	unsigned int max_ip_conns;
237 
238 	while (!kthread_should_stop()) {
239 		mutex_lock(&iface->sock_release_lock);
240 		if (!iface->ksmbd_socket) {
241 			mutex_unlock(&iface->sock_release_lock);
242 			break;
243 		}
244 		ret = kernel_accept(iface->ksmbd_socket, &client_sk,
245 				    SOCK_NONBLOCK);
246 		mutex_unlock(&iface->sock_release_lock);
247 		if (ret) {
248 			if (ret == -EAGAIN)
249 				/* check for new connections every 100 msecs */
250 				schedule_timeout_interruptible(HZ / 10);
251 			continue;
252 		}
253 
254 		if (!server_conf.max_ip_connections)
255 			goto skip_max_ip_conns_limit;
256 
257 		/*
258 		 * Limits repeated connections from clients with the same IP.
259 		 */
260 #if IS_ENABLED(CONFIG_IPV6)
261 		if (client_sk->sk->sk_family == AF_INET6)
262 			inet_hash = ipv6_addr_hash(&client_sk->sk->sk_v6_daddr);
263 		else
264 			inet_hash = ipv4_addr_hash(inet_sk(client_sk->sk)->inet_daddr);
265 #else
266 		inet_hash = ipv4_addr_hash(inet_sk(client_sk->sk)->inet_daddr);
267 #endif
268 
269 		max_ip_conns = 0;
270 		down_read(&conn_list_lock);
271 		hash_for_each_possible(conn_list, conn, hlist, inet_hash) {
272 #if IS_ENABLED(CONFIG_IPV6)
273 			if (client_sk->sk->sk_family == AF_INET6) {
274 				if (memcmp(&client_sk->sk->sk_v6_daddr,
275 					   &conn->inet6_addr, 16) == 0)
276 					max_ip_conns++;
277 			} else if (inet_sk(client_sk->sk)->inet_daddr ==
278 				 conn->inet_addr)
279 				max_ip_conns++;
280 #else
281 			if (inet_sk(client_sk->sk)->inet_daddr ==
282 			    conn->inet_addr)
283 				max_ip_conns++;
284 #endif
285 			if (server_conf.max_ip_connections <= max_ip_conns) {
286 				pr_info_ratelimited("Maximum IP connections exceeded (%u/%u)\n",
287 						    max_ip_conns, server_conf.max_ip_connections);
288 				ret = -EAGAIN;
289 				break;
290 			}
291 		}
292 		up_read(&conn_list_lock);
293 		if (ret == -EAGAIN)
294 			continue;
295 
296 skip_max_ip_conns_limit:
297 		if (server_conf.max_connections &&
298 		    atomic_inc_return(&active_num_conn) >= server_conf.max_connections) {
299 			pr_info_ratelimited("Limit the maximum number of connections(%u)\n",
300 					    atomic_read(&active_num_conn));
301 			atomic_dec(&active_num_conn);
302 			sock_release(client_sk);
303 			continue;
304 		}
305 
306 		ksmbd_debug(CONN, "connect success: accepted new connection\n");
307 		client_sk->sk->sk_rcvtimeo = KSMBD_TCP_RECV_TIMEOUT;
308 		client_sk->sk->sk_sndtimeo = KSMBD_TCP_SEND_TIMEOUT;
309 
310 		ksmbd_tcp_new_connection(client_sk);
311 	}
312 
313 	ksmbd_debug(CONN, "releasing socket\n");
314 	return 0;
315 }
316 
317 /**
318  * ksmbd_tcp_run_kthread() - start forker thread
319  * @iface: pointer to struct interface
320  *
321  * start forker thread(ksmbd/0) at module init time to listen
322  * on port 445 for new SMB connection requests. It creates per connection
323  * server threads(ksmbd/x)
324  *
325  * Return:	0 on success or error number
326  */
ksmbd_tcp_run_kthread(struct interface * iface)327 static int ksmbd_tcp_run_kthread(struct interface *iface)
328 {
329 	int rc;
330 	struct task_struct *kthread;
331 
332 	kthread = kthread_run(ksmbd_kthread_fn, (void *)iface, "ksmbd-%s",
333 			      iface->name);
334 	if (IS_ERR(kthread)) {
335 		rc = PTR_ERR(kthread);
336 		return rc;
337 	}
338 	iface->ksmbd_kthread = kthread;
339 
340 	return 0;
341 }
342 
343 /**
344  * ksmbd_tcp_readv() - read data from socket in given iovec
345  * @t:			TCP transport instance
346  * @iov_orig:		base IO vector
347  * @nr_segs:		number of segments in base iov
348  * @to_read:		number of bytes to read from socket
349  * @max_retries:	maximum retry count
350  *
351  * Return:	on success return number of bytes read from socket,
352  *		otherwise return error number
353  */
ksmbd_tcp_readv(struct tcp_transport * t,struct kvec * iov_orig,unsigned int nr_segs,unsigned int to_read,int max_retries)354 static int ksmbd_tcp_readv(struct tcp_transport *t, struct kvec *iov_orig,
355 			   unsigned int nr_segs, unsigned int to_read,
356 			   int max_retries)
357 {
358 	int length = 0;
359 	int total_read;
360 	unsigned int segs;
361 	struct msghdr ksmbd_msg;
362 	struct kvec *iov;
363 	struct ksmbd_conn *conn = KSMBD_TRANS(t)->conn;
364 
365 	iov = get_conn_iovec(t, nr_segs);
366 	if (!iov)
367 		return -ENOMEM;
368 
369 	ksmbd_msg.msg_control = NULL;
370 	ksmbd_msg.msg_controllen = 0;
371 
372 	for (total_read = 0; to_read; total_read += length, to_read -= length) {
373 		try_to_freeze();
374 
375 		if (!ksmbd_conn_alive(conn)) {
376 			total_read = -ESHUTDOWN;
377 			break;
378 		}
379 		segs = kvec_array_init(iov, iov_orig, nr_segs, total_read);
380 
381 		length = kernel_recvmsg(t->sock, &ksmbd_msg,
382 					iov, segs, to_read, 0);
383 
384 		if (length == -EINTR) {
385 			total_read = -ESHUTDOWN;
386 			break;
387 		} else if (ksmbd_conn_need_reconnect(conn)) {
388 			total_read = -EAGAIN;
389 			break;
390 		} else if (length == -ERESTARTSYS || length == -EAGAIN) {
391 			/*
392 			 * If max_retries is negative, Allow unlimited
393 			 * retries to keep connection with inactive sessions.
394 			 */
395 			if (max_retries == 0) {
396 				total_read = length;
397 				break;
398 			} else if (max_retries > 0) {
399 				max_retries--;
400 			}
401 
402 			usleep_range(1000, 2000);
403 			length = 0;
404 			continue;
405 		} else if (length <= 0) {
406 			total_read = length;
407 			break;
408 		}
409 	}
410 	return total_read;
411 }
412 
413 /**
414  * ksmbd_tcp_read() - read data from socket in given buffer
415  * @t:		TCP transport instance
416  * @buf:	buffer to store read data from socket
417  * @to_read:	number of bytes to read from socket
418  * @max_retries: number of retries if reading from socket fails
419  *
420  * Return:	on success return number of bytes read from socket,
421  *		otherwise return error number
422  */
ksmbd_tcp_read(struct ksmbd_transport * t,char * buf,unsigned int to_read,int max_retries)423 static int ksmbd_tcp_read(struct ksmbd_transport *t, char *buf,
424 			  unsigned int to_read, int max_retries)
425 {
426 	struct kvec iov;
427 
428 	iov.iov_base = buf;
429 	iov.iov_len = to_read;
430 
431 	return ksmbd_tcp_readv(TCP_TRANS(t), &iov, 1, to_read, max_retries);
432 }
433 
ksmbd_tcp_writev(struct ksmbd_transport * t,struct kvec * iov,int nvecs,int size,bool need_invalidate,unsigned int remote_key)434 static int ksmbd_tcp_writev(struct ksmbd_transport *t, struct kvec *iov,
435 			    int nvecs, int size, bool need_invalidate,
436 			    unsigned int remote_key)
437 
438 {
439 	struct msghdr smb_msg = {.msg_flags = MSG_NOSIGNAL};
440 
441 	return kernel_sendmsg(TCP_TRANS(t)->sock, &smb_msg, iov, nvecs, size);
442 }
443 
ksmbd_tcp_disconnect(struct ksmbd_transport * t)444 static void ksmbd_tcp_disconnect(struct ksmbd_transport *t)
445 {
446 	free_transport(TCP_TRANS(t));
447 	if (server_conf.max_connections)
448 		atomic_dec(&active_num_conn);
449 }
450 
tcp_destroy_socket(struct socket * ksmbd_socket)451 static void tcp_destroy_socket(struct socket *ksmbd_socket)
452 {
453 	int ret;
454 
455 	if (!ksmbd_socket)
456 		return;
457 
458 	/* set zero to timeout */
459 	ksmbd_tcp_rcv_timeout(ksmbd_socket, 0);
460 	ksmbd_tcp_snd_timeout(ksmbd_socket, 0);
461 
462 	ret = kernel_sock_shutdown(ksmbd_socket, SHUT_RDWR);
463 	if (ret)
464 		pr_err("Failed to shutdown socket: %d\n", ret);
465 	sock_release(ksmbd_socket);
466 }
467 
468 /**
469  * create_socket - create socket for ksmbd/0
470  * @iface:      interface to bind the created socket to
471  *
472  * Return:	0 on success, error number otherwise
473  */
create_socket(struct interface * iface)474 static int create_socket(struct interface *iface)
475 {
476 	int ret;
477 	struct sockaddr_in6 sin6;
478 	struct sockaddr_in sin;
479 	struct socket *ksmbd_socket;
480 	bool ipv4 = false;
481 
482 	ret = sock_create_kern(current->nsproxy->net_ns, PF_INET6, SOCK_STREAM,
483 			IPPROTO_TCP, &ksmbd_socket);
484 	if (ret) {
485 		if (ret != -EAFNOSUPPORT)
486 			pr_err("Can't create socket for ipv6, fallback to ipv4: %d\n", ret);
487 		ret = sock_create_kern(current->nsproxy->net_ns, PF_INET,
488 				SOCK_STREAM, IPPROTO_TCP, &ksmbd_socket);
489 		if (ret) {
490 			pr_err("Can't create socket for ipv4: %d\n", ret);
491 			goto out_clear;
492 		}
493 
494 		sin.sin_family = PF_INET;
495 		sin.sin_addr.s_addr = htonl(INADDR_ANY);
496 		sin.sin_port = htons(server_conf.tcp_port);
497 		ipv4 = true;
498 	} else {
499 		sin6.sin6_family = PF_INET6;
500 		sin6.sin6_addr = in6addr_any;
501 		sin6.sin6_port = htons(server_conf.tcp_port);
502 
503 		lock_sock(ksmbd_socket->sk);
504 		ksmbd_socket->sk->sk_ipv6only = false;
505 		release_sock(ksmbd_socket->sk);
506 	}
507 
508 	ksmbd_tcp_nodelay(ksmbd_socket);
509 	ksmbd_tcp_reuseaddr(ksmbd_socket);
510 
511 	ret = sock_setsockopt(ksmbd_socket,
512 			      SOL_SOCKET,
513 			      SO_BINDTODEVICE,
514 			      KERNEL_SOCKPTR(iface->name),
515 			      strlen(iface->name));
516 	if (ret != -ENODEV && ret < 0) {
517 		pr_err("Failed to set SO_BINDTODEVICE: %d\n", ret);
518 		goto out_error;
519 	}
520 
521 	if (ipv4)
522 		ret = kernel_bind(ksmbd_socket, (struct sockaddr *)&sin,
523 				  sizeof(sin));
524 	else
525 		ret = kernel_bind(ksmbd_socket, (struct sockaddr *)&sin6,
526 				  sizeof(sin6));
527 	if (ret) {
528 		pr_err("Failed to bind socket: %d\n", ret);
529 		goto out_error;
530 	}
531 
532 	ksmbd_socket->sk->sk_rcvtimeo = KSMBD_TCP_RECV_TIMEOUT;
533 	ksmbd_socket->sk->sk_sndtimeo = KSMBD_TCP_SEND_TIMEOUT;
534 
535 	ret = kernel_listen(ksmbd_socket, KSMBD_SOCKET_BACKLOG);
536 	if (ret) {
537 		pr_err("Port listen() error: %d\n", ret);
538 		goto out_error;
539 	}
540 
541 	iface->ksmbd_socket = ksmbd_socket;
542 	ret = ksmbd_tcp_run_kthread(iface);
543 	if (ret) {
544 		pr_err("Can't start ksmbd main kthread: %d\n", ret);
545 		goto out_error;
546 	}
547 	iface->state = IFACE_STATE_CONFIGURED;
548 
549 	return 0;
550 
551 out_error:
552 	tcp_destroy_socket(ksmbd_socket);
553 out_clear:
554 	iface->ksmbd_socket = NULL;
555 	return ret;
556 }
557 
ksmbd_find_netdev_name_iface_list(char * netdev_name)558 struct interface *ksmbd_find_netdev_name_iface_list(char *netdev_name)
559 {
560 	struct interface *iface;
561 
562 	list_for_each_entry(iface, &iface_list, entry)
563 		if (!strcmp(iface->name, netdev_name))
564 			return iface;
565 	return NULL;
566 }
567 
ksmbd_netdev_event(struct notifier_block * nb,unsigned long event,void * ptr)568 static int ksmbd_netdev_event(struct notifier_block *nb, unsigned long event,
569 			      void *ptr)
570 {
571 	struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
572 	struct interface *iface;
573 	int ret;
574 
575 	switch (event) {
576 	case NETDEV_UP:
577 		if (netif_is_bridge_port(netdev))
578 			return NOTIFY_OK;
579 
580 		iface = ksmbd_find_netdev_name_iface_list(netdev->name);
581 		if (iface && iface->state == IFACE_STATE_DOWN) {
582 			ksmbd_debug(CONN, "netdev-up event: netdev(%s) is going up\n",
583 					iface->name);
584 			ret = create_socket(iface);
585 			if (ret)
586 				return NOTIFY_OK;
587 		}
588 		if (!iface && bind_additional_ifaces) {
589 			iface = alloc_iface(kstrdup(netdev->name, KSMBD_DEFAULT_GFP));
590 			if (!iface)
591 				return NOTIFY_OK;
592 			ksmbd_debug(CONN, "netdev-up event: netdev(%s) is going up\n",
593 				    iface->name);
594 			ret = create_socket(iface);
595 			if (ret)
596 				break;
597 		}
598 		break;
599 	case NETDEV_DOWN:
600 		iface = ksmbd_find_netdev_name_iface_list(netdev->name);
601 		if (iface && iface->state == IFACE_STATE_CONFIGURED) {
602 			ksmbd_debug(CONN, "netdev-down event: netdev(%s) is going down\n",
603 					iface->name);
604 			tcp_stop_kthread(iface->ksmbd_kthread);
605 			iface->ksmbd_kthread = NULL;
606 			mutex_lock(&iface->sock_release_lock);
607 			tcp_destroy_socket(iface->ksmbd_socket);
608 			iface->ksmbd_socket = NULL;
609 			mutex_unlock(&iface->sock_release_lock);
610 
611 			iface->state = IFACE_STATE_DOWN;
612 			break;
613 		}
614 		break;
615 	}
616 
617 	return NOTIFY_DONE;
618 }
619 
620 static struct notifier_block ksmbd_netdev_notifier = {
621 	.notifier_call = ksmbd_netdev_event,
622 };
623 
ksmbd_tcp_init(void)624 int ksmbd_tcp_init(void)
625 {
626 	register_netdevice_notifier(&ksmbd_netdev_notifier);
627 
628 	return 0;
629 }
630 
tcp_stop_kthread(struct task_struct * kthread)631 static void tcp_stop_kthread(struct task_struct *kthread)
632 {
633 	int ret;
634 
635 	if (!kthread)
636 		return;
637 
638 	ret = kthread_stop(kthread);
639 	if (ret)
640 		pr_err("failed to stop forker thread\n");
641 }
642 
ksmbd_tcp_destroy(void)643 void ksmbd_tcp_destroy(void)
644 {
645 	struct interface *iface, *tmp;
646 
647 	unregister_netdevice_notifier(&ksmbd_netdev_notifier);
648 
649 	list_for_each_entry_safe(iface, tmp, &iface_list, entry) {
650 		list_del(&iface->entry);
651 		kfree(iface->name);
652 		kfree(iface);
653 	}
654 }
655 
alloc_iface(char * ifname)656 static struct interface *alloc_iface(char *ifname)
657 {
658 	struct interface *iface;
659 
660 	if (!ifname)
661 		return NULL;
662 
663 	iface = kzalloc(sizeof(struct interface), KSMBD_DEFAULT_GFP);
664 	if (!iface) {
665 		kfree(ifname);
666 		return NULL;
667 	}
668 
669 	iface->name = ifname;
670 	iface->state = IFACE_STATE_DOWN;
671 	list_add(&iface->entry, &iface_list);
672 	mutex_init(&iface->sock_release_lock);
673 	return iface;
674 }
675 
ksmbd_tcp_set_interfaces(char * ifc_list,int ifc_list_sz)676 int ksmbd_tcp_set_interfaces(char *ifc_list, int ifc_list_sz)
677 {
678 	int sz = 0;
679 
680 	if (!ifc_list_sz) {
681 		bind_additional_ifaces = 1;
682 		return 0;
683 	}
684 
685 	while (ifc_list_sz > 0) {
686 		if (!alloc_iface(kstrdup(ifc_list, KSMBD_DEFAULT_GFP)))
687 			return -ENOMEM;
688 
689 		sz = strlen(ifc_list);
690 		if (!sz)
691 			break;
692 
693 		ifc_list += sz + 1;
694 		ifc_list_sz -= (sz + 1);
695 	}
696 
697 	bind_additional_ifaces = 0;
698 
699 	return 0;
700 }
701 
702 static const struct ksmbd_transport_ops ksmbd_tcp_transport_ops = {
703 	.read		= ksmbd_tcp_read,
704 	.writev		= ksmbd_tcp_writev,
705 	.disconnect	= ksmbd_tcp_disconnect,
706 	.free_transport = ksmbd_tcp_free_transport,
707 };
708