xref: /linux/fs/smb/server/server.c (revision 466b2d40f60ce874cb9b56dc88bd1a0880a43786)
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 "glob.h"
8 #include "oplock.h"
9 #include "misc.h"
10 #include <linux/sched/signal.h>
11 #include <linux/workqueue.h>
12 #include <linux/sysfs.h>
13 #include <linux/module.h>
14 #include <linux/moduleparam.h>
15 
16 #include "server.h"
17 #include "smb_common.h"
18 #include "../common/smb2status.h"
19 #include "connection.h"
20 #include "transport_ipc.h"
21 #include "mgmt/user_session.h"
22 #include "crypto_ctx.h"
23 #include "auth.h"
24 
25 int ksmbd_debug_types;
26 
27 struct ksmbd_server_config server_conf;
28 
29 enum SERVER_CTRL_TYPE {
30 	SERVER_CTRL_TYPE_INIT,
31 	SERVER_CTRL_TYPE_RESET,
32 };
33 
34 struct server_ctrl_struct {
35 	int			type;
36 	struct work_struct	ctrl_work;
37 };
38 
39 static DEFINE_MUTEX(ctrl_lock);
40 
___server_conf_set(int idx,char * val)41 static int ___server_conf_set(int idx, char *val)
42 {
43 	if (idx >= ARRAY_SIZE(server_conf.conf))
44 		return -EINVAL;
45 
46 	if (!val || val[0] == 0x00)
47 		return -EINVAL;
48 
49 	kfree(server_conf.conf[idx]);
50 	server_conf.conf[idx] = kstrdup(val, KSMBD_DEFAULT_GFP);
51 	if (!server_conf.conf[idx])
52 		return -ENOMEM;
53 	return 0;
54 }
55 
ksmbd_set_netbios_name(char * v)56 int ksmbd_set_netbios_name(char *v)
57 {
58 	return ___server_conf_set(SERVER_CONF_NETBIOS_NAME, v);
59 }
60 
ksmbd_set_server_string(char * v)61 int ksmbd_set_server_string(char *v)
62 {
63 	return ___server_conf_set(SERVER_CONF_SERVER_STRING, v);
64 }
65 
ksmbd_set_work_group(char * v)66 int ksmbd_set_work_group(char *v)
67 {
68 	return ___server_conf_set(SERVER_CONF_WORK_GROUP, v);
69 }
70 
ksmbd_netbios_name(void)71 char *ksmbd_netbios_name(void)
72 {
73 	return server_conf.conf[SERVER_CONF_NETBIOS_NAME];
74 }
75 
ksmbd_server_string(void)76 char *ksmbd_server_string(void)
77 {
78 	return server_conf.conf[SERVER_CONF_SERVER_STRING];
79 }
80 
ksmbd_work_group(void)81 char *ksmbd_work_group(void)
82 {
83 	return server_conf.conf[SERVER_CONF_WORK_GROUP];
84 }
85 
86 /**
87  * check_conn_state() - check state of server thread connection
88  * @work:     smb work containing server thread information
89  *
90  * Return:	0 on valid connection, otherwise 1 to reconnect
91  */
check_conn_state(struct ksmbd_work * work)92 static inline int check_conn_state(struct ksmbd_work *work)
93 {
94 	struct smb_hdr *rsp_hdr;
95 
96 	if (ksmbd_conn_exiting(work->conn) ||
97 	    ksmbd_conn_need_reconnect(work->conn)) {
98 		rsp_hdr = work->response_buf;
99 		rsp_hdr->Status.CifsError = STATUS_CONNECTION_DISCONNECTED;
100 		return 1;
101 	}
102 	return 0;
103 }
104 
105 #define SERVER_HANDLER_CONTINUE		0
106 #define SERVER_HANDLER_ABORT		1
107 
__process_request(struct ksmbd_work * work,struct ksmbd_conn * conn,u16 * cmd)108 static int __process_request(struct ksmbd_work *work, struct ksmbd_conn *conn,
109 			     u16 *cmd)
110 {
111 	struct smb_version_cmds *cmds;
112 	u16 command;
113 	int ret;
114 
115 	if (check_conn_state(work))
116 		return SERVER_HANDLER_CONTINUE;
117 
118 	if (ksmbd_verify_smb_message(work)) {
119 		conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER);
120 		return SERVER_HANDLER_ABORT;
121 	}
122 
123 	command = conn->ops->get_cmd_val(work);
124 	*cmd = command;
125 
126 andx_again:
127 	if (command >= conn->max_cmds) {
128 		conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER);
129 		return SERVER_HANDLER_CONTINUE;
130 	}
131 
132 	cmds = &conn->cmds[command];
133 	if (!cmds->proc) {
134 		ksmbd_debug(SMB, "*** not implemented yet cmd = %x\n", command);
135 		conn->ops->set_rsp_status(work, STATUS_NOT_IMPLEMENTED);
136 		return SERVER_HANDLER_CONTINUE;
137 	}
138 
139 	if (work->sess && conn->ops->is_sign_req(work, command)) {
140 		ret = conn->ops->check_sign_req(work);
141 		if (!ret) {
142 			conn->ops->set_rsp_status(work, STATUS_ACCESS_DENIED);
143 			return SERVER_HANDLER_CONTINUE;
144 		}
145 	}
146 
147 	ret = cmds->proc(work);
148 
149 	if (ret < 0)
150 		ksmbd_debug(CONN, "Failed to process %u [%d]\n", command, ret);
151 	/* AndX commands - chained request can return positive values */
152 	else if (ret > 0) {
153 		command = ret;
154 		*cmd = command;
155 		goto andx_again;
156 	}
157 
158 	if (work->send_no_response)
159 		return SERVER_HANDLER_ABORT;
160 	return SERVER_HANDLER_CONTINUE;
161 }
162 
__handle_ksmbd_work(struct ksmbd_work * work,struct ksmbd_conn * conn)163 static void __handle_ksmbd_work(struct ksmbd_work *work,
164 				struct ksmbd_conn *conn)
165 {
166 	u16 command = 0;
167 	int rc;
168 	bool is_chained = false;
169 
170 	if (conn->ops->is_transform_hdr &&
171 	    conn->ops->is_transform_hdr(work->request_buf)) {
172 		rc = conn->ops->decrypt_req(work);
173 		if (rc < 0)
174 			return;
175 		work->encrypted = true;
176 	}
177 
178 	if (conn->ops->allocate_rsp_buf(work))
179 		return;
180 
181 	rc = conn->ops->init_rsp_hdr(work);
182 	if (rc) {
183 		/* either uid or tid is not correct */
184 		conn->ops->set_rsp_status(work, STATUS_INVALID_HANDLE);
185 		goto send;
186 	}
187 
188 	do {
189 		if (conn->ops->check_user_session) {
190 			rc = conn->ops->check_user_session(work);
191 			if (rc < 0) {
192 				if (rc == -EINVAL)
193 					conn->ops->set_rsp_status(work,
194 						STATUS_INVALID_PARAMETER);
195 				else
196 					conn->ops->set_rsp_status(work,
197 						STATUS_USER_SESSION_DELETED);
198 				goto send;
199 			} else if (rc > 0) {
200 				rc = conn->ops->get_ksmbd_tcon(work);
201 				if (rc < 0) {
202 					if (rc == -EINVAL)
203 						conn->ops->set_rsp_status(work,
204 							STATUS_INVALID_PARAMETER);
205 					else
206 						conn->ops->set_rsp_status(work,
207 							STATUS_NETWORK_NAME_DELETED);
208 					goto send;
209 				}
210 			}
211 		}
212 
213 		rc = __process_request(work, conn, &command);
214 		if (rc == SERVER_HANDLER_ABORT)
215 			break;
216 
217 		/*
218 		 * Call smb2_set_rsp_credits() function to set number of credits
219 		 * granted in hdr of smb2 response.
220 		 */
221 		if (conn->ops->set_rsp_credits) {
222 			spin_lock(&conn->credits_lock);
223 			rc = conn->ops->set_rsp_credits(work);
224 			spin_unlock(&conn->credits_lock);
225 			if (rc < 0) {
226 				conn->ops->set_rsp_status(work,
227 					STATUS_INVALID_PARAMETER);
228 				goto send;
229 			}
230 		}
231 
232 		is_chained = is_chained_smb2_message(work);
233 
234 		if (work->sess &&
235 		    (work->sess->sign || smb3_11_final_sess_setup_resp(work) ||
236 		     conn->ops->is_sign_req(work, command)))
237 			conn->ops->set_sign_rsp(work);
238 	} while (is_chained == true);
239 
240 send:
241 	if (work->tcon)
242 		ksmbd_tree_connect_put(work->tcon);
243 	smb3_preauth_hash_rsp(work);
244 	if (work->sess && work->sess->enc && work->encrypted &&
245 	    conn->ops->encrypt_resp) {
246 		rc = conn->ops->encrypt_resp(work);
247 		if (rc < 0)
248 			conn->ops->set_rsp_status(work, STATUS_DATA_ERROR);
249 	}
250 	if (work->sess)
251 		ksmbd_user_session_put(work->sess);
252 
253 	ksmbd_conn_write(work);
254 }
255 
256 /**
257  * handle_ksmbd_work() - process pending smb work requests
258  * @wk:	smb work containing request command buffer
259  *
260  * called by kworker threads to processing remaining smb work requests
261  */
handle_ksmbd_work(struct work_struct * wk)262 static void handle_ksmbd_work(struct work_struct *wk)
263 {
264 	struct ksmbd_work *work = container_of(wk, struct ksmbd_work, work);
265 	struct ksmbd_conn *conn = work->conn;
266 
267 	atomic64_inc(&conn->stats.request_served);
268 
269 	__handle_ksmbd_work(work, conn);
270 
271 	ksmbd_conn_try_dequeue_request(work);
272 	ksmbd_free_work_struct(work);
273 	/*
274 	 * Checking waitqueue to dropping pending requests on
275 	 * disconnection. waitqueue_active is safe because it
276 	 * uses atomic operation for condition.
277 	 */
278 	atomic_inc(&conn->refcnt);
279 	if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q))
280 		wake_up(&conn->r_count_q);
281 
282 	if (atomic_dec_and_test(&conn->refcnt))
283 		kfree(conn);
284 }
285 
286 /**
287  * queue_ksmbd_work() - queue a smb request to worker thread queue
288  *		for processing smb command and sending response
289  * @conn:	connection instance
290  *
291  * read remaining data from socket create and submit work.
292  */
queue_ksmbd_work(struct ksmbd_conn * conn)293 static int queue_ksmbd_work(struct ksmbd_conn *conn)
294 {
295 	struct ksmbd_work *work;
296 	int err;
297 
298 	err = ksmbd_init_smb_server(conn);
299 	if (err)
300 		return 0;
301 
302 	work = ksmbd_alloc_work_struct();
303 	if (!work) {
304 		pr_err("allocation for work failed\n");
305 		return -ENOMEM;
306 	}
307 
308 	work->conn = conn;
309 	work->request_buf = conn->request_buf;
310 	conn->request_buf = NULL;
311 
312 	ksmbd_conn_enqueue_request(work);
313 	atomic_inc(&conn->r_count);
314 	/* update activity on connection */
315 	conn->last_active = jiffies;
316 	INIT_WORK(&work->work, handle_ksmbd_work);
317 	ksmbd_queue_work(work);
318 	return 0;
319 }
320 
ksmbd_server_process_request(struct ksmbd_conn * conn)321 static int ksmbd_server_process_request(struct ksmbd_conn *conn)
322 {
323 	return queue_ksmbd_work(conn);
324 }
325 
ksmbd_server_terminate_conn(struct ksmbd_conn * conn)326 static int ksmbd_server_terminate_conn(struct ksmbd_conn *conn)
327 {
328 	ksmbd_sessions_deregister(conn);
329 	destroy_lease_table(conn);
330 	return 0;
331 }
332 
ksmbd_server_tcp_callbacks_init(void)333 static void ksmbd_server_tcp_callbacks_init(void)
334 {
335 	struct ksmbd_conn_ops ops;
336 
337 	ops.process_fn = ksmbd_server_process_request;
338 	ops.terminate_fn = ksmbd_server_terminate_conn;
339 
340 	ksmbd_conn_init_server_callbacks(&ops);
341 }
342 
server_conf_free(void)343 static void server_conf_free(void)
344 {
345 	int i;
346 
347 	for (i = 0; i < ARRAY_SIZE(server_conf.conf); i++) {
348 		kfree(server_conf.conf[i]);
349 		server_conf.conf[i] = NULL;
350 	}
351 }
352 
server_conf_init(void)353 static int server_conf_init(void)
354 {
355 	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
356 	server_conf.enforced_signing = 0;
357 	server_conf.min_protocol = ksmbd_min_protocol();
358 	server_conf.max_protocol = ksmbd_max_protocol();
359 	server_conf.auth_mechs = KSMBD_AUTH_NTLMSSP;
360 #ifdef CONFIG_SMB_SERVER_KERBEROS5
361 	server_conf.auth_mechs |= KSMBD_AUTH_KRB5 |
362 				KSMBD_AUTH_MSKRB5;
363 #endif
364 	server_conf.max_inflight_req = SMB2_MAX_CREDITS;
365 	return 0;
366 }
367 
server_ctrl_handle_init(struct server_ctrl_struct * ctrl)368 static void server_ctrl_handle_init(struct server_ctrl_struct *ctrl)
369 {
370 	int ret;
371 
372 	ret = ksmbd_conn_transport_init();
373 	if (ret) {
374 		server_queue_ctrl_reset_work();
375 		return;
376 	}
377 
378 	WRITE_ONCE(server_conf.state, SERVER_STATE_RUNNING);
379 }
380 
server_ctrl_handle_reset(struct server_ctrl_struct * ctrl)381 static void server_ctrl_handle_reset(struct server_ctrl_struct *ctrl)
382 {
383 	ksmbd_ipc_soft_reset();
384 	ksmbd_conn_transport_destroy();
385 	ksmbd_stop_durable_scavenger();
386 	server_conf_free();
387 	server_conf_init();
388 	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
389 }
390 
server_ctrl_handle_work(struct work_struct * work)391 static void server_ctrl_handle_work(struct work_struct *work)
392 {
393 	struct server_ctrl_struct *ctrl;
394 
395 	ctrl = container_of(work, struct server_ctrl_struct, ctrl_work);
396 
397 	mutex_lock(&ctrl_lock);
398 	switch (ctrl->type) {
399 	case SERVER_CTRL_TYPE_INIT:
400 		server_ctrl_handle_init(ctrl);
401 		break;
402 	case SERVER_CTRL_TYPE_RESET:
403 		server_ctrl_handle_reset(ctrl);
404 		break;
405 	default:
406 		pr_err("Unknown server work type: %d\n", ctrl->type);
407 	}
408 	mutex_unlock(&ctrl_lock);
409 	kfree(ctrl);
410 	module_put(THIS_MODULE);
411 }
412 
__queue_ctrl_work(int type)413 static int __queue_ctrl_work(int type)
414 {
415 	struct server_ctrl_struct *ctrl;
416 
417 	ctrl = kmalloc(sizeof(struct server_ctrl_struct), KSMBD_DEFAULT_GFP);
418 	if (!ctrl)
419 		return -ENOMEM;
420 
421 	__module_get(THIS_MODULE);
422 	ctrl->type = type;
423 	INIT_WORK(&ctrl->ctrl_work, server_ctrl_handle_work);
424 	queue_work(system_long_wq, &ctrl->ctrl_work);
425 	return 0;
426 }
427 
server_queue_ctrl_init_work(void)428 int server_queue_ctrl_init_work(void)
429 {
430 	return __queue_ctrl_work(SERVER_CTRL_TYPE_INIT);
431 }
432 
server_queue_ctrl_reset_work(void)433 int server_queue_ctrl_reset_work(void)
434 {
435 	return __queue_ctrl_work(SERVER_CTRL_TYPE_RESET);
436 }
437 
stats_show(const struct class * class,const struct class_attribute * attr,char * buf)438 static ssize_t stats_show(const struct class *class, const struct class_attribute *attr,
439 			  char *buf)
440 {
441 	/*
442 	 * Inc this each time you change stats output format,
443 	 * so user space will know what to do.
444 	 */
445 	static int stats_version = 2;
446 	static const char * const state[] = {
447 		"startup",
448 		"running",
449 		"reset",
450 		"shutdown"
451 	};
452 	return sysfs_emit(buf, "%d %s %d %lu\n", stats_version,
453 			  state[server_conf.state], server_conf.tcp_port,
454 			  server_conf.ipc_last_active / HZ);
455 }
456 
kill_server_store(const struct class * class,const struct class_attribute * attr,const char * buf,size_t len)457 static ssize_t kill_server_store(const struct class *class,
458 				 const struct class_attribute *attr, const char *buf,
459 				 size_t len)
460 {
461 	if (!sysfs_streq(buf, "hard"))
462 		return len;
463 
464 	pr_info("kill command received\n");
465 	mutex_lock(&ctrl_lock);
466 	WRITE_ONCE(server_conf.state, SERVER_STATE_RESETTING);
467 	__module_get(THIS_MODULE);
468 	server_ctrl_handle_reset(NULL);
469 	module_put(THIS_MODULE);
470 	mutex_unlock(&ctrl_lock);
471 	return len;
472 }
473 
474 static const char * const debug_type_strings[] = {"smb", "auth", "vfs",
475 						  "oplock", "ipc", "conn",
476 						  "rdma"};
477 
debug_show(const struct class * class,const struct class_attribute * attr,char * buf)478 static ssize_t debug_show(const struct class *class, const struct class_attribute *attr,
479 			  char *buf)
480 {
481 	ssize_t sz = 0;
482 	int i, pos = 0;
483 
484 	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
485 		if ((ksmbd_debug_types >> i) & 1) {
486 			pos = sysfs_emit_at(buf, sz, "[%s] ", debug_type_strings[i]);
487 		} else {
488 			pos = sysfs_emit_at(buf, sz, "%s ", debug_type_strings[i]);
489 		}
490 		sz += pos;
491 	}
492 	sz += sysfs_emit_at(buf, sz, "\n");
493 	return sz;
494 }
495 
debug_store(const struct class * class,const struct class_attribute * attr,const char * buf,size_t len)496 static ssize_t debug_store(const struct class *class, const struct class_attribute *attr,
497 			   const char *buf, size_t len)
498 {
499 	int i;
500 
501 	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
502 		if (sysfs_streq(buf, "all")) {
503 			if (ksmbd_debug_types == KSMBD_DEBUG_ALL)
504 				ksmbd_debug_types = 0;
505 			else
506 				ksmbd_debug_types = KSMBD_DEBUG_ALL;
507 			break;
508 		}
509 
510 		if (sysfs_streq(buf, debug_type_strings[i])) {
511 			if (ksmbd_debug_types & (1 << i))
512 				ksmbd_debug_types &= ~(1 << i);
513 			else
514 				ksmbd_debug_types |= (1 << i);
515 			break;
516 		}
517 	}
518 
519 	return len;
520 }
521 
522 static CLASS_ATTR_RO(stats);
523 static CLASS_ATTR_WO(kill_server);
524 static CLASS_ATTR_RW(debug);
525 
526 static struct attribute *ksmbd_control_class_attrs[] = {
527 	&class_attr_stats.attr,
528 	&class_attr_kill_server.attr,
529 	&class_attr_debug.attr,
530 	NULL,
531 };
532 ATTRIBUTE_GROUPS(ksmbd_control_class);
533 
534 static struct class ksmbd_control_class = {
535 	.name		= "ksmbd-control",
536 	.class_groups	= ksmbd_control_class_groups,
537 };
538 
ksmbd_server_shutdown(void)539 static int ksmbd_server_shutdown(void)
540 {
541 	WRITE_ONCE(server_conf.state, SERVER_STATE_SHUTTING_DOWN);
542 
543 	class_unregister(&ksmbd_control_class);
544 	ksmbd_workqueue_destroy();
545 	ksmbd_ipc_release();
546 	ksmbd_conn_transport_destroy();
547 	ksmbd_crypto_destroy();
548 	ksmbd_free_global_file_table();
549 	destroy_lease_table(NULL);
550 	ksmbd_work_pool_destroy();
551 	ksmbd_exit_file_cache();
552 	server_conf_free();
553 	return 0;
554 }
555 
ksmbd_server_init(void)556 static int __init ksmbd_server_init(void)
557 {
558 	int ret;
559 
560 	ret = class_register(&ksmbd_control_class);
561 	if (ret) {
562 		pr_err("Unable to register ksmbd-control class\n");
563 		return ret;
564 	}
565 
566 	ksmbd_server_tcp_callbacks_init();
567 
568 	ret = server_conf_init();
569 	if (ret)
570 		goto err_unregister;
571 
572 	ret = ksmbd_work_pool_init();
573 	if (ret)
574 		goto err_unregister;
575 
576 	ret = ksmbd_init_file_cache();
577 	if (ret)
578 		goto err_destroy_work_pools;
579 
580 	ret = ksmbd_ipc_init();
581 	if (ret)
582 		goto err_exit_file_cache;
583 
584 	ret = ksmbd_init_global_file_table();
585 	if (ret)
586 		goto err_ipc_release;
587 
588 	ret = ksmbd_inode_hash_init();
589 	if (ret)
590 		goto err_destroy_file_table;
591 
592 	ret = ksmbd_crypto_create();
593 	if (ret)
594 		goto err_release_inode_hash;
595 
596 	ret = ksmbd_workqueue_init();
597 	if (ret)
598 		goto err_crypto_destroy;
599 
600 	return 0;
601 
602 err_crypto_destroy:
603 	ksmbd_crypto_destroy();
604 err_release_inode_hash:
605 	ksmbd_release_inode_hash();
606 err_destroy_file_table:
607 	ksmbd_free_global_file_table();
608 err_ipc_release:
609 	ksmbd_ipc_release();
610 err_exit_file_cache:
611 	ksmbd_exit_file_cache();
612 err_destroy_work_pools:
613 	ksmbd_work_pool_destroy();
614 err_unregister:
615 	class_unregister(&ksmbd_control_class);
616 
617 	return ret;
618 }
619 
620 /**
621  * ksmbd_server_exit() - shutdown forker thread and free memory at module exit
622  */
ksmbd_server_exit(void)623 static void __exit ksmbd_server_exit(void)
624 {
625 	ksmbd_server_shutdown();
626 	rcu_barrier();
627 	ksmbd_release_inode_hash();
628 }
629 
630 MODULE_AUTHOR("Namjae Jeon <linkinjeon@kernel.org>");
631 MODULE_DESCRIPTION("Linux kernel CIFS/SMB SERVER");
632 MODULE_LICENSE("GPL");
633 MODULE_SOFTDEP("pre: ecb");
634 MODULE_SOFTDEP("pre: hmac");
635 MODULE_SOFTDEP("pre: md5");
636 MODULE_SOFTDEP("pre: nls");
637 MODULE_SOFTDEP("pre: aes");
638 MODULE_SOFTDEP("pre: cmac");
639 MODULE_SOFTDEP("pre: sha256");
640 MODULE_SOFTDEP("pre: sha512");
641 MODULE_SOFTDEP("pre: aead2");
642 MODULE_SOFTDEP("pre: ccm");
643 MODULE_SOFTDEP("pre: gcm");
644 MODULE_SOFTDEP("pre: crc32");
645 module_init(ksmbd_server_init)
646 module_exit(ksmbd_server_exit)
647