xref: /linux/fs/smb/server/server.c (revision 95444b9eeb8c5c0330563931d70c61ca3b101548)
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 "smbstatus.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 
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, GFP_KERNEL);
51 	if (!server_conf.conf[idx])
52 		return -ENOMEM;
53 	return 0;
54 }
55 
56 int ksmbd_set_netbios_name(char *v)
57 {
58 	return ___server_conf_set(SERVER_CONF_NETBIOS_NAME, v);
59 }
60 
61 int ksmbd_set_server_string(char *v)
62 {
63 	return ___server_conf_set(SERVER_CONF_SERVER_STRING, v);
64 }
65 
66 int ksmbd_set_work_group(char *v)
67 {
68 	return ___server_conf_set(SERVER_CONF_WORK_GROUP, v);
69 }
70 
71 char *ksmbd_netbios_name(void)
72 {
73 	return server_conf.conf[SERVER_CONF_NETBIOS_NAME];
74 }
75 
76 char *ksmbd_server_string(void)
77 {
78 	return server_conf.conf[SERVER_CONF_SERVER_STRING];
79 }
80 
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  */
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 
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 
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 
251 	ksmbd_conn_write(work);
252 }
253 
254 /**
255  * handle_ksmbd_work() - process pending smb work requests
256  * @wk:	smb work containing request command buffer
257  *
258  * called by kworker threads to processing remaining smb work requests
259  */
260 static void handle_ksmbd_work(struct work_struct *wk)
261 {
262 	struct ksmbd_work *work = container_of(wk, struct ksmbd_work, work);
263 	struct ksmbd_conn *conn = work->conn;
264 
265 	atomic64_inc(&conn->stats.request_served);
266 
267 	__handle_ksmbd_work(work, conn);
268 
269 	ksmbd_conn_try_dequeue_request(work);
270 	ksmbd_free_work_struct(work);
271 	/*
272 	 * Checking waitqueue to dropping pending requests on
273 	 * disconnection. waitqueue_active is safe because it
274 	 * uses atomic operation for condition.
275 	 */
276 	if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q))
277 		wake_up(&conn->r_count_q);
278 }
279 
280 /**
281  * queue_ksmbd_work() - queue a smb request to worker thread queue
282  *		for proccessing smb command and sending response
283  * @conn:	connection instance
284  *
285  * read remaining data from socket create and submit work.
286  */
287 static int queue_ksmbd_work(struct ksmbd_conn *conn)
288 {
289 	struct ksmbd_work *work;
290 	int err;
291 
292 	work = ksmbd_alloc_work_struct();
293 	if (!work) {
294 		pr_err("allocation for work failed\n");
295 		return -ENOMEM;
296 	}
297 
298 	work->conn = conn;
299 	work->request_buf = conn->request_buf;
300 	conn->request_buf = NULL;
301 
302 	err = ksmbd_init_smb_server(work);
303 	if (err) {
304 		ksmbd_free_work_struct(work);
305 		return 0;
306 	}
307 
308 	ksmbd_conn_enqueue_request(work);
309 	atomic_inc(&conn->r_count);
310 	/* update activity on connection */
311 	conn->last_active = jiffies;
312 	INIT_WORK(&work->work, handle_ksmbd_work);
313 	ksmbd_queue_work(work);
314 	return 0;
315 }
316 
317 static int ksmbd_server_process_request(struct ksmbd_conn *conn)
318 {
319 	return queue_ksmbd_work(conn);
320 }
321 
322 static int ksmbd_server_terminate_conn(struct ksmbd_conn *conn)
323 {
324 	ksmbd_sessions_deregister(conn);
325 	destroy_lease_table(conn);
326 	return 0;
327 }
328 
329 static void ksmbd_server_tcp_callbacks_init(void)
330 {
331 	struct ksmbd_conn_ops ops;
332 
333 	ops.process_fn = ksmbd_server_process_request;
334 	ops.terminate_fn = ksmbd_server_terminate_conn;
335 
336 	ksmbd_conn_init_server_callbacks(&ops);
337 }
338 
339 static void server_conf_free(void)
340 {
341 	int i;
342 
343 	for (i = 0; i < ARRAY_SIZE(server_conf.conf); i++) {
344 		kfree(server_conf.conf[i]);
345 		server_conf.conf[i] = NULL;
346 	}
347 }
348 
349 static int server_conf_init(void)
350 {
351 	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
352 	server_conf.enforced_signing = 0;
353 	server_conf.min_protocol = ksmbd_min_protocol();
354 	server_conf.max_protocol = ksmbd_max_protocol();
355 	server_conf.auth_mechs = KSMBD_AUTH_NTLMSSP;
356 #ifdef CONFIG_SMB_SERVER_KERBEROS5
357 	server_conf.auth_mechs |= KSMBD_AUTH_KRB5 |
358 				KSMBD_AUTH_MSKRB5;
359 #endif
360 	return 0;
361 }
362 
363 static void server_ctrl_handle_init(struct server_ctrl_struct *ctrl)
364 {
365 	int ret;
366 
367 	ret = ksmbd_conn_transport_init();
368 	if (ret) {
369 		server_queue_ctrl_reset_work();
370 		return;
371 	}
372 
373 	WRITE_ONCE(server_conf.state, SERVER_STATE_RUNNING);
374 }
375 
376 static void server_ctrl_handle_reset(struct server_ctrl_struct *ctrl)
377 {
378 	ksmbd_ipc_soft_reset();
379 	ksmbd_conn_transport_destroy();
380 	server_conf_free();
381 	server_conf_init();
382 	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
383 }
384 
385 static void server_ctrl_handle_work(struct work_struct *work)
386 {
387 	struct server_ctrl_struct *ctrl;
388 
389 	ctrl = container_of(work, struct server_ctrl_struct, ctrl_work);
390 
391 	mutex_lock(&ctrl_lock);
392 	switch (ctrl->type) {
393 	case SERVER_CTRL_TYPE_INIT:
394 		server_ctrl_handle_init(ctrl);
395 		break;
396 	case SERVER_CTRL_TYPE_RESET:
397 		server_ctrl_handle_reset(ctrl);
398 		break;
399 	default:
400 		pr_err("Unknown server work type: %d\n", ctrl->type);
401 	}
402 	mutex_unlock(&ctrl_lock);
403 	kfree(ctrl);
404 	module_put(THIS_MODULE);
405 }
406 
407 static int __queue_ctrl_work(int type)
408 {
409 	struct server_ctrl_struct *ctrl;
410 
411 	ctrl = kmalloc(sizeof(struct server_ctrl_struct), GFP_KERNEL);
412 	if (!ctrl)
413 		return -ENOMEM;
414 
415 	__module_get(THIS_MODULE);
416 	ctrl->type = type;
417 	INIT_WORK(&ctrl->ctrl_work, server_ctrl_handle_work);
418 	queue_work(system_long_wq, &ctrl->ctrl_work);
419 	return 0;
420 }
421 
422 int server_queue_ctrl_init_work(void)
423 {
424 	return __queue_ctrl_work(SERVER_CTRL_TYPE_INIT);
425 }
426 
427 int server_queue_ctrl_reset_work(void)
428 {
429 	return __queue_ctrl_work(SERVER_CTRL_TYPE_RESET);
430 }
431 
432 static ssize_t stats_show(const struct class *class, const struct class_attribute *attr,
433 			  char *buf)
434 {
435 	/*
436 	 * Inc this each time you change stats output format,
437 	 * so user space will know what to do.
438 	 */
439 	static int stats_version = 2;
440 	static const char * const state[] = {
441 		"startup",
442 		"running",
443 		"reset",
444 		"shutdown"
445 	};
446 	return sysfs_emit(buf, "%d %s %d %lu\n", stats_version,
447 			  state[server_conf.state], server_conf.tcp_port,
448 			  server_conf.ipc_last_active / HZ);
449 }
450 
451 static ssize_t kill_server_store(const struct class *class,
452 				 const struct class_attribute *attr, const char *buf,
453 				 size_t len)
454 {
455 	if (!sysfs_streq(buf, "hard"))
456 		return len;
457 
458 	pr_info("kill command received\n");
459 	mutex_lock(&ctrl_lock);
460 	WRITE_ONCE(server_conf.state, SERVER_STATE_RESETTING);
461 	__module_get(THIS_MODULE);
462 	server_ctrl_handle_reset(NULL);
463 	module_put(THIS_MODULE);
464 	mutex_unlock(&ctrl_lock);
465 	return len;
466 }
467 
468 static const char * const debug_type_strings[] = {"smb", "auth", "vfs",
469 						  "oplock", "ipc", "conn",
470 						  "rdma"};
471 
472 static ssize_t debug_show(const struct class *class, const struct class_attribute *attr,
473 			  char *buf)
474 {
475 	ssize_t sz = 0;
476 	int i, pos = 0;
477 
478 	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
479 		if ((ksmbd_debug_types >> i) & 1) {
480 			pos = sysfs_emit_at(buf, sz, "[%s] ", debug_type_strings[i]);
481 		} else {
482 			pos = sysfs_emit_at(buf, sz, "%s ", debug_type_strings[i]);
483 		}
484 		sz += pos;
485 	}
486 	sz += sysfs_emit_at(buf, sz, "\n");
487 	return sz;
488 }
489 
490 static ssize_t debug_store(const struct class *class, const struct class_attribute *attr,
491 			   const char *buf, size_t len)
492 {
493 	int i;
494 
495 	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
496 		if (sysfs_streq(buf, "all")) {
497 			if (ksmbd_debug_types == KSMBD_DEBUG_ALL)
498 				ksmbd_debug_types = 0;
499 			else
500 				ksmbd_debug_types = KSMBD_DEBUG_ALL;
501 			break;
502 		}
503 
504 		if (sysfs_streq(buf, debug_type_strings[i])) {
505 			if (ksmbd_debug_types & (1 << i))
506 				ksmbd_debug_types &= ~(1 << i);
507 			else
508 				ksmbd_debug_types |= (1 << i);
509 			break;
510 		}
511 	}
512 
513 	return len;
514 }
515 
516 static CLASS_ATTR_RO(stats);
517 static CLASS_ATTR_WO(kill_server);
518 static CLASS_ATTR_RW(debug);
519 
520 static struct attribute *ksmbd_control_class_attrs[] = {
521 	&class_attr_stats.attr,
522 	&class_attr_kill_server.attr,
523 	&class_attr_debug.attr,
524 	NULL,
525 };
526 ATTRIBUTE_GROUPS(ksmbd_control_class);
527 
528 static struct class ksmbd_control_class = {
529 	.name		= "ksmbd-control",
530 	.class_groups	= ksmbd_control_class_groups,
531 };
532 
533 static int ksmbd_server_shutdown(void)
534 {
535 	WRITE_ONCE(server_conf.state, SERVER_STATE_SHUTTING_DOWN);
536 
537 	class_unregister(&ksmbd_control_class);
538 	ksmbd_workqueue_destroy();
539 	ksmbd_ipc_release();
540 	ksmbd_conn_transport_destroy();
541 	ksmbd_crypto_destroy();
542 	ksmbd_free_global_file_table();
543 	destroy_lease_table(NULL);
544 	ksmbd_work_pool_destroy();
545 	ksmbd_exit_file_cache();
546 	server_conf_free();
547 	return 0;
548 }
549 
550 static int __init ksmbd_server_init(void)
551 {
552 	int ret;
553 
554 	ret = class_register(&ksmbd_control_class);
555 	if (ret) {
556 		pr_err("Unable to register ksmbd-control class\n");
557 		return ret;
558 	}
559 
560 	ksmbd_server_tcp_callbacks_init();
561 
562 	ret = server_conf_init();
563 	if (ret)
564 		goto err_unregister;
565 
566 	ret = ksmbd_work_pool_init();
567 	if (ret)
568 		goto err_unregister;
569 
570 	ret = ksmbd_init_file_cache();
571 	if (ret)
572 		goto err_destroy_work_pools;
573 
574 	ret = ksmbd_ipc_init();
575 	if (ret)
576 		goto err_exit_file_cache;
577 
578 	ret = ksmbd_init_global_file_table();
579 	if (ret)
580 		goto err_ipc_release;
581 
582 	ret = ksmbd_inode_hash_init();
583 	if (ret)
584 		goto err_destroy_file_table;
585 
586 	ret = ksmbd_crypto_create();
587 	if (ret)
588 		goto err_release_inode_hash;
589 
590 	ret = ksmbd_workqueue_init();
591 	if (ret)
592 		goto err_crypto_destroy;
593 
594 	return 0;
595 
596 err_crypto_destroy:
597 	ksmbd_crypto_destroy();
598 err_release_inode_hash:
599 	ksmbd_release_inode_hash();
600 err_destroy_file_table:
601 	ksmbd_free_global_file_table();
602 err_ipc_release:
603 	ksmbd_ipc_release();
604 err_exit_file_cache:
605 	ksmbd_exit_file_cache();
606 err_destroy_work_pools:
607 	ksmbd_work_pool_destroy();
608 err_unregister:
609 	class_unregister(&ksmbd_control_class);
610 
611 	return ret;
612 }
613 
614 /**
615  * ksmbd_server_exit() - shutdown forker thread and free memory at module exit
616  */
617 static void __exit ksmbd_server_exit(void)
618 {
619 	ksmbd_server_shutdown();
620 	rcu_barrier();
621 	ksmbd_release_inode_hash();
622 }
623 
624 MODULE_AUTHOR("Namjae Jeon <linkinjeon@kernel.org>");
625 MODULE_DESCRIPTION("Linux kernel CIFS/SMB SERVER");
626 MODULE_LICENSE("GPL");
627 MODULE_SOFTDEP("pre: ecb");
628 MODULE_SOFTDEP("pre: hmac");
629 MODULE_SOFTDEP("pre: md5");
630 MODULE_SOFTDEP("pre: nls");
631 MODULE_SOFTDEP("pre: aes");
632 MODULE_SOFTDEP("pre: cmac");
633 MODULE_SOFTDEP("pre: sha256");
634 MODULE_SOFTDEP("pre: sha512");
635 MODULE_SOFTDEP("pre: aead2");
636 MODULE_SOFTDEP("pre: ccm");
637 MODULE_SOFTDEP("pre: gcm");
638 MODULE_SOFTDEP("pre: crc32");
639 module_init(ksmbd_server_init)
640 module_exit(ksmbd_server_exit)
641