xref: /linux/fs/smb/server/server.c (revision 71dfa617ea9f18e4585fe78364217cd32b1fc382)
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->allocate_rsp_buf(work))
171 		return;
172 
173 	if (conn->ops->is_transform_hdr &&
174 	    conn->ops->is_transform_hdr(work->request_buf)) {
175 		rc = conn->ops->decrypt_req(work);
176 		if (rc < 0) {
177 			conn->ops->set_rsp_status(work, STATUS_DATA_ERROR);
178 			goto send;
179 		}
180 
181 		work->encrypted = true;
182 	}
183 
184 	rc = conn->ops->init_rsp_hdr(work);
185 	if (rc) {
186 		/* either uid or tid is not correct */
187 		conn->ops->set_rsp_status(work, STATUS_INVALID_HANDLE);
188 		goto send;
189 	}
190 
191 	do {
192 		if (conn->ops->check_user_session) {
193 			rc = conn->ops->check_user_session(work);
194 			if (rc < 0) {
195 				if (rc == -EINVAL)
196 					conn->ops->set_rsp_status(work,
197 						STATUS_INVALID_PARAMETER);
198 				else
199 					conn->ops->set_rsp_status(work,
200 						STATUS_USER_SESSION_DELETED);
201 				goto send;
202 			} else if (rc > 0) {
203 				rc = conn->ops->get_ksmbd_tcon(work);
204 				if (rc < 0) {
205 					if (rc == -EINVAL)
206 						conn->ops->set_rsp_status(work,
207 							STATUS_INVALID_PARAMETER);
208 					else
209 						conn->ops->set_rsp_status(work,
210 							STATUS_NETWORK_NAME_DELETED);
211 					goto send;
212 				}
213 			}
214 		}
215 
216 		rc = __process_request(work, conn, &command);
217 		if (rc == SERVER_HANDLER_ABORT)
218 			break;
219 
220 		/*
221 		 * Call smb2_set_rsp_credits() function to set number of credits
222 		 * granted in hdr of smb2 response.
223 		 */
224 		if (conn->ops->set_rsp_credits) {
225 			spin_lock(&conn->credits_lock);
226 			rc = conn->ops->set_rsp_credits(work);
227 			spin_unlock(&conn->credits_lock);
228 			if (rc < 0) {
229 				conn->ops->set_rsp_status(work,
230 					STATUS_INVALID_PARAMETER);
231 				goto send;
232 			}
233 		}
234 
235 		is_chained = is_chained_smb2_message(work);
236 
237 		if (work->sess &&
238 		    (work->sess->sign || smb3_11_final_sess_setup_resp(work) ||
239 		     conn->ops->is_sign_req(work, command)))
240 			conn->ops->set_sign_rsp(work);
241 	} while (is_chained == true);
242 
243 send:
244 	if (work->tcon)
245 		ksmbd_tree_connect_put(work->tcon);
246 	smb3_preauth_hash_rsp(work);
247 	if (work->sess && work->sess->enc && work->encrypted &&
248 	    conn->ops->encrypt_resp) {
249 		rc = conn->ops->encrypt_resp(work);
250 		if (rc < 0)
251 			conn->ops->set_rsp_status(work, STATUS_DATA_ERROR);
252 	}
253 
254 	ksmbd_conn_write(work);
255 }
256 
257 /**
258  * handle_ksmbd_work() - process pending smb work requests
259  * @wk:	smb work containing request command buffer
260  *
261  * called by kworker threads to processing remaining smb work requests
262  */
263 static void handle_ksmbd_work(struct work_struct *wk)
264 {
265 	struct ksmbd_work *work = container_of(wk, struct ksmbd_work, work);
266 	struct ksmbd_conn *conn = work->conn;
267 
268 	atomic64_inc(&conn->stats.request_served);
269 
270 	__handle_ksmbd_work(work, conn);
271 
272 	ksmbd_conn_try_dequeue_request(work);
273 	ksmbd_free_work_struct(work);
274 	/*
275 	 * Checking waitqueue to dropping pending requests on
276 	 * disconnection. waitqueue_active is safe because it
277 	 * uses atomic operation for condition.
278 	 */
279 	if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q))
280 		wake_up(&conn->r_count_q);
281 }
282 
283 /**
284  * queue_ksmbd_work() - queue a smb request to worker thread queue
285  *		for proccessing smb command and sending response
286  * @conn:	connection instance
287  *
288  * read remaining data from socket create and submit work.
289  */
290 static int queue_ksmbd_work(struct ksmbd_conn *conn)
291 {
292 	struct ksmbd_work *work;
293 	int err;
294 
295 	work = ksmbd_alloc_work_struct();
296 	if (!work) {
297 		pr_err("allocation for work failed\n");
298 		return -ENOMEM;
299 	}
300 
301 	work->conn = conn;
302 	work->request_buf = conn->request_buf;
303 	conn->request_buf = NULL;
304 
305 	err = ksmbd_init_smb_server(work);
306 	if (err) {
307 		ksmbd_free_work_struct(work);
308 		return 0;
309 	}
310 
311 	ksmbd_conn_enqueue_request(work);
312 	atomic_inc(&conn->r_count);
313 	/* update activity on connection */
314 	conn->last_active = jiffies;
315 	INIT_WORK(&work->work, handle_ksmbd_work);
316 	ksmbd_queue_work(work);
317 	return 0;
318 }
319 
320 static int ksmbd_server_process_request(struct ksmbd_conn *conn)
321 {
322 	return queue_ksmbd_work(conn);
323 }
324 
325 static int ksmbd_server_terminate_conn(struct ksmbd_conn *conn)
326 {
327 	ksmbd_sessions_deregister(conn);
328 	destroy_lease_table(conn);
329 	return 0;
330 }
331 
332 static void ksmbd_server_tcp_callbacks_init(void)
333 {
334 	struct ksmbd_conn_ops ops;
335 
336 	ops.process_fn = ksmbd_server_process_request;
337 	ops.terminate_fn = ksmbd_server_terminate_conn;
338 
339 	ksmbd_conn_init_server_callbacks(&ops);
340 }
341 
342 static void server_conf_free(void)
343 {
344 	int i;
345 
346 	for (i = 0; i < ARRAY_SIZE(server_conf.conf); i++) {
347 		kfree(server_conf.conf[i]);
348 		server_conf.conf[i] = NULL;
349 	}
350 }
351 
352 static int server_conf_init(void)
353 {
354 	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
355 	server_conf.enforced_signing = 0;
356 	server_conf.min_protocol = ksmbd_min_protocol();
357 	server_conf.max_protocol = ksmbd_max_protocol();
358 	server_conf.auth_mechs = KSMBD_AUTH_NTLMSSP;
359 #ifdef CONFIG_SMB_SERVER_KERBEROS5
360 	server_conf.auth_mechs |= KSMBD_AUTH_KRB5 |
361 				KSMBD_AUTH_MSKRB5;
362 #endif
363 	return 0;
364 }
365 
366 static void server_ctrl_handle_init(struct server_ctrl_struct *ctrl)
367 {
368 	int ret;
369 
370 	ret = ksmbd_conn_transport_init();
371 	if (ret) {
372 		server_queue_ctrl_reset_work();
373 		return;
374 	}
375 
376 	WRITE_ONCE(server_conf.state, SERVER_STATE_RUNNING);
377 }
378 
379 static void server_ctrl_handle_reset(struct server_ctrl_struct *ctrl)
380 {
381 	ksmbd_ipc_soft_reset();
382 	ksmbd_conn_transport_destroy();
383 	server_conf_free();
384 	server_conf_init();
385 	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
386 }
387 
388 static void server_ctrl_handle_work(struct work_struct *work)
389 {
390 	struct server_ctrl_struct *ctrl;
391 
392 	ctrl = container_of(work, struct server_ctrl_struct, ctrl_work);
393 
394 	mutex_lock(&ctrl_lock);
395 	switch (ctrl->type) {
396 	case SERVER_CTRL_TYPE_INIT:
397 		server_ctrl_handle_init(ctrl);
398 		break;
399 	case SERVER_CTRL_TYPE_RESET:
400 		server_ctrl_handle_reset(ctrl);
401 		break;
402 	default:
403 		pr_err("Unknown server work type: %d\n", ctrl->type);
404 	}
405 	mutex_unlock(&ctrl_lock);
406 	kfree(ctrl);
407 	module_put(THIS_MODULE);
408 }
409 
410 static int __queue_ctrl_work(int type)
411 {
412 	struct server_ctrl_struct *ctrl;
413 
414 	ctrl = kmalloc(sizeof(struct server_ctrl_struct), GFP_KERNEL);
415 	if (!ctrl)
416 		return -ENOMEM;
417 
418 	__module_get(THIS_MODULE);
419 	ctrl->type = type;
420 	INIT_WORK(&ctrl->ctrl_work, server_ctrl_handle_work);
421 	queue_work(system_long_wq, &ctrl->ctrl_work);
422 	return 0;
423 }
424 
425 int server_queue_ctrl_init_work(void)
426 {
427 	return __queue_ctrl_work(SERVER_CTRL_TYPE_INIT);
428 }
429 
430 int server_queue_ctrl_reset_work(void)
431 {
432 	return __queue_ctrl_work(SERVER_CTRL_TYPE_RESET);
433 }
434 
435 static ssize_t stats_show(const struct class *class, const struct class_attribute *attr,
436 			  char *buf)
437 {
438 	/*
439 	 * Inc this each time you change stats output format,
440 	 * so user space will know what to do.
441 	 */
442 	static int stats_version = 2;
443 	static const char * const state[] = {
444 		"startup",
445 		"running",
446 		"reset",
447 		"shutdown"
448 	};
449 	return sysfs_emit(buf, "%d %s %d %lu\n", stats_version,
450 			  state[server_conf.state], server_conf.tcp_port,
451 			  server_conf.ipc_last_active / HZ);
452 }
453 
454 static ssize_t kill_server_store(const struct class *class,
455 				 const struct class_attribute *attr, const char *buf,
456 				 size_t len)
457 {
458 	if (!sysfs_streq(buf, "hard"))
459 		return len;
460 
461 	pr_info("kill command received\n");
462 	mutex_lock(&ctrl_lock);
463 	WRITE_ONCE(server_conf.state, SERVER_STATE_RESETTING);
464 	__module_get(THIS_MODULE);
465 	server_ctrl_handle_reset(NULL);
466 	module_put(THIS_MODULE);
467 	mutex_unlock(&ctrl_lock);
468 	return len;
469 }
470 
471 static const char * const debug_type_strings[] = {"smb", "auth", "vfs",
472 						  "oplock", "ipc", "conn",
473 						  "rdma"};
474 
475 static ssize_t debug_show(const struct class *class, const struct class_attribute *attr,
476 			  char *buf)
477 {
478 	ssize_t sz = 0;
479 	int i, pos = 0;
480 
481 	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
482 		if ((ksmbd_debug_types >> i) & 1) {
483 			pos = sysfs_emit_at(buf, sz, "[%s] ", debug_type_strings[i]);
484 		} else {
485 			pos = sysfs_emit_at(buf, sz, "%s ", debug_type_strings[i]);
486 		}
487 		sz += pos;
488 	}
489 	sz += sysfs_emit_at(buf, sz, "\n");
490 	return sz;
491 }
492 
493 static ssize_t debug_store(const struct class *class, const struct class_attribute *attr,
494 			   const char *buf, size_t len)
495 {
496 	int i;
497 
498 	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
499 		if (sysfs_streq(buf, "all")) {
500 			if (ksmbd_debug_types == KSMBD_DEBUG_ALL)
501 				ksmbd_debug_types = 0;
502 			else
503 				ksmbd_debug_types = KSMBD_DEBUG_ALL;
504 			break;
505 		}
506 
507 		if (sysfs_streq(buf, debug_type_strings[i])) {
508 			if (ksmbd_debug_types & (1 << i))
509 				ksmbd_debug_types &= ~(1 << i);
510 			else
511 				ksmbd_debug_types |= (1 << i);
512 			break;
513 		}
514 	}
515 
516 	return len;
517 }
518 
519 static CLASS_ATTR_RO(stats);
520 static CLASS_ATTR_WO(kill_server);
521 static CLASS_ATTR_RW(debug);
522 
523 static struct attribute *ksmbd_control_class_attrs[] = {
524 	&class_attr_stats.attr,
525 	&class_attr_kill_server.attr,
526 	&class_attr_debug.attr,
527 	NULL,
528 };
529 ATTRIBUTE_GROUPS(ksmbd_control_class);
530 
531 static struct class ksmbd_control_class = {
532 	.name		= "ksmbd-control",
533 	.class_groups	= ksmbd_control_class_groups,
534 };
535 
536 static int ksmbd_server_shutdown(void)
537 {
538 	WRITE_ONCE(server_conf.state, SERVER_STATE_SHUTTING_DOWN);
539 
540 	class_unregister(&ksmbd_control_class);
541 	ksmbd_workqueue_destroy();
542 	ksmbd_ipc_release();
543 	ksmbd_conn_transport_destroy();
544 	ksmbd_crypto_destroy();
545 	ksmbd_free_global_file_table();
546 	destroy_lease_table(NULL);
547 	ksmbd_work_pool_destroy();
548 	ksmbd_exit_file_cache();
549 	server_conf_free();
550 	return 0;
551 }
552 
553 static int __init ksmbd_server_init(void)
554 {
555 	int ret;
556 
557 	ret = class_register(&ksmbd_control_class);
558 	if (ret) {
559 		pr_err("Unable to register ksmbd-control class\n");
560 		return ret;
561 	}
562 
563 	ksmbd_server_tcp_callbacks_init();
564 
565 	ret = server_conf_init();
566 	if (ret)
567 		goto err_unregister;
568 
569 	ret = ksmbd_work_pool_init();
570 	if (ret)
571 		goto err_unregister;
572 
573 	ret = ksmbd_init_file_cache();
574 	if (ret)
575 		goto err_destroy_work_pools;
576 
577 	ret = ksmbd_ipc_init();
578 	if (ret)
579 		goto err_exit_file_cache;
580 
581 	ret = ksmbd_init_global_file_table();
582 	if (ret)
583 		goto err_ipc_release;
584 
585 	ret = ksmbd_inode_hash_init();
586 	if (ret)
587 		goto err_destroy_file_table;
588 
589 	ret = ksmbd_crypto_create();
590 	if (ret)
591 		goto err_release_inode_hash;
592 
593 	ret = ksmbd_workqueue_init();
594 	if (ret)
595 		goto err_crypto_destroy;
596 
597 	return 0;
598 
599 err_crypto_destroy:
600 	ksmbd_crypto_destroy();
601 err_release_inode_hash:
602 	ksmbd_release_inode_hash();
603 err_destroy_file_table:
604 	ksmbd_free_global_file_table();
605 err_ipc_release:
606 	ksmbd_ipc_release();
607 err_exit_file_cache:
608 	ksmbd_exit_file_cache();
609 err_destroy_work_pools:
610 	ksmbd_work_pool_destroy();
611 err_unregister:
612 	class_unregister(&ksmbd_control_class);
613 
614 	return ret;
615 }
616 
617 /**
618  * ksmbd_server_exit() - shutdown forker thread and free memory at module exit
619  */
620 static void __exit ksmbd_server_exit(void)
621 {
622 	ksmbd_server_shutdown();
623 	rcu_barrier();
624 	ksmbd_release_inode_hash();
625 }
626 
627 MODULE_AUTHOR("Namjae Jeon <linkinjeon@kernel.org>");
628 MODULE_DESCRIPTION("Linux kernel CIFS/SMB SERVER");
629 MODULE_LICENSE("GPL");
630 MODULE_SOFTDEP("pre: ecb");
631 MODULE_SOFTDEP("pre: hmac");
632 MODULE_SOFTDEP("pre: md5");
633 MODULE_SOFTDEP("pre: nls");
634 MODULE_SOFTDEP("pre: aes");
635 MODULE_SOFTDEP("pre: cmac");
636 MODULE_SOFTDEP("pre: sha256");
637 MODULE_SOFTDEP("pre: sha512");
638 MODULE_SOFTDEP("pre: aead2");
639 MODULE_SOFTDEP("pre: ccm");
640 MODULE_SOFTDEP("pre: gcm");
641 MODULE_SOFTDEP("pre: crc32");
642 module_init(ksmbd_server_init)
643 module_exit(ksmbd_server_exit)
644