xref: /linux/fs/smb/server/server.c (revision bf4afc53b77aeaa48b5409da5c8da6bb4eff7f43)
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 #include "stats.h"
25 
26 int ksmbd_debug_types;
27 
28 struct ksmbd_server_config server_conf;
29 
30 enum SERVER_CTRL_TYPE {
31 	SERVER_CTRL_TYPE_INIT,
32 	SERVER_CTRL_TYPE_RESET,
33 };
34 
35 struct server_ctrl_struct {
36 	int			type;
37 	struct work_struct	ctrl_work;
38 };
39 
40 static DEFINE_MUTEX(ctrl_lock);
41 
42 static int ___server_conf_set(int idx, char *val)
43 {
44 	if (idx >= ARRAY_SIZE(server_conf.conf))
45 		return -EINVAL;
46 
47 	if (!val || val[0] == 0x00)
48 		return -EINVAL;
49 
50 	kfree(server_conf.conf[idx]);
51 	server_conf.conf[idx] = kstrdup(val, KSMBD_DEFAULT_GFP);
52 	if (!server_conf.conf[idx])
53 		return -ENOMEM;
54 	return 0;
55 }
56 
57 int ksmbd_set_netbios_name(char *v)
58 {
59 	return ___server_conf_set(SERVER_CONF_NETBIOS_NAME, v);
60 }
61 
62 int ksmbd_set_server_string(char *v)
63 {
64 	return ___server_conf_set(SERVER_CONF_SERVER_STRING, v);
65 }
66 
67 int ksmbd_set_work_group(char *v)
68 {
69 	return ___server_conf_set(SERVER_CONF_WORK_GROUP, v);
70 }
71 
72 char *ksmbd_netbios_name(void)
73 {
74 	return server_conf.conf[SERVER_CONF_NETBIOS_NAME];
75 }
76 
77 char *ksmbd_server_string(void)
78 {
79 	return server_conf.conf[SERVER_CONF_SERVER_STRING];
80 }
81 
82 char *ksmbd_work_group(void)
83 {
84 	return server_conf.conf[SERVER_CONF_WORK_GROUP];
85 }
86 
87 /**
88  * check_conn_state() - check state of server thread connection
89  * @work:     smb work containing server thread information
90  *
91  * Return:	0 on valid connection, otherwise 1 to reconnect
92  */
93 static inline int check_conn_state(struct ksmbd_work *work)
94 {
95 	struct smb_hdr *rsp_hdr;
96 
97 	if (ksmbd_conn_exiting(work->conn) ||
98 	    ksmbd_conn_need_reconnect(work->conn)) {
99 		rsp_hdr = smb_get_msg(work->response_buf);
100 		rsp_hdr->Status.CifsError = STATUS_CONNECTION_DISCONNECTED;
101 		return 1;
102 	}
103 	return 0;
104 }
105 
106 #define SERVER_HANDLER_CONTINUE		0
107 #define SERVER_HANDLER_ABORT		1
108 
109 static int __process_request(struct ksmbd_work *work, struct ksmbd_conn *conn,
110 			     u16 *cmd)
111 {
112 	struct smb_version_cmds *cmds;
113 	u16 command;
114 	int ret;
115 
116 	if (check_conn_state(work))
117 		return SERVER_HANDLER_CONTINUE;
118 
119 	if (ksmbd_verify_smb_message(work)) {
120 		conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER);
121 		return SERVER_HANDLER_ABORT;
122 	}
123 
124 	command = conn->ops->get_cmd_val(work);
125 	*cmd = command;
126 
127 andx_again:
128 	if (command >= conn->max_cmds) {
129 		conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER);
130 		return SERVER_HANDLER_ABORT;
131 	}
132 
133 	cmds = &conn->cmds[command];
134 	if (!cmds->proc) {
135 		ksmbd_debug(SMB, "*** not implemented yet cmd = %x\n", command);
136 		conn->ops->set_rsp_status(work, STATUS_NOT_IMPLEMENTED);
137 		return SERVER_HANDLER_ABORT;
138 	}
139 
140 	if (work->sess && conn->ops->is_sign_req(work, command)) {
141 		ret = conn->ops->check_sign_req(work);
142 		if (!ret) {
143 			conn->ops->set_rsp_status(work, STATUS_ACCESS_DENIED);
144 			return SERVER_HANDLER_ABORT;
145 		}
146 	}
147 
148 	ret = cmds->proc(work);
149 	if (conn->ops->inc_reqs)
150 		conn->ops->inc_reqs(command);
151 
152 	if (ret < 0)
153 		ksmbd_debug(CONN, "Failed to process %u [%d]\n", command, ret);
154 	/* AndX commands - chained request can return positive values */
155 	else if (ret > 0) {
156 		command = ret;
157 		*cmd = command;
158 		goto andx_again;
159 	}
160 
161 	if (work->send_no_response)
162 		return SERVER_HANDLER_ABORT;
163 	return SERVER_HANDLER_CONTINUE;
164 }
165 
166 static void __handle_ksmbd_work(struct ksmbd_work *work,
167 				struct ksmbd_conn *conn)
168 {
169 	u16 command = 0;
170 	int rc;
171 	bool is_chained = false;
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 			return;
178 		work->encrypted = true;
179 	}
180 
181 	if (conn->ops->allocate_rsp_buf(work))
182 		return;
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 	if (work->sess)
254 		ksmbd_user_session_put(work->sess);
255 
256 	ksmbd_conn_write(work);
257 }
258 
259 /**
260  * handle_ksmbd_work() - process pending smb work requests
261  * @wk:	smb work containing request command buffer
262  *
263  * called by kworker threads to processing remaining smb work requests
264  */
265 static void handle_ksmbd_work(struct work_struct *wk)
266 {
267 	struct ksmbd_work *work = container_of(wk, struct ksmbd_work, work);
268 	struct ksmbd_conn *conn = work->conn;
269 
270 	atomic64_inc(&conn->stats.request_served);
271 
272 	__handle_ksmbd_work(work, conn);
273 
274 	ksmbd_conn_try_dequeue_request(work);
275 	ksmbd_free_work_struct(work);
276 	ksmbd_conn_r_count_dec(conn);
277 }
278 
279 /**
280  * queue_ksmbd_work() - queue a smb request to worker thread queue
281  *		for processing smb command and sending response
282  * @conn:	connection instance
283  *
284  * read remaining data from socket create and submit work.
285  */
286 static int queue_ksmbd_work(struct ksmbd_conn *conn)
287 {
288 	struct ksmbd_work *work;
289 	int err;
290 
291 	err = ksmbd_init_smb_server(conn);
292 	if (err)
293 		return 0;
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 	ksmbd_conn_enqueue_request(work);
306 	ksmbd_conn_r_count_inc(conn);
307 	/* update activity on connection */
308 	conn->last_active = jiffies;
309 	INIT_WORK(&work->work, handle_ksmbd_work);
310 	ksmbd_queue_work(work);
311 	return 0;
312 }
313 
314 static int ksmbd_server_process_request(struct ksmbd_conn *conn)
315 {
316 	return queue_ksmbd_work(conn);
317 }
318 
319 static int ksmbd_server_terminate_conn(struct ksmbd_conn *conn)
320 {
321 	ksmbd_sessions_deregister(conn);
322 	destroy_lease_table(conn);
323 	return 0;
324 }
325 
326 static void ksmbd_server_tcp_callbacks_init(void)
327 {
328 	struct ksmbd_conn_ops ops;
329 
330 	ops.process_fn = ksmbd_server_process_request;
331 	ops.terminate_fn = ksmbd_server_terminate_conn;
332 
333 	ksmbd_conn_init_server_callbacks(&ops);
334 }
335 
336 static void server_conf_free(void)
337 {
338 	int i;
339 
340 	for (i = 0; i < ARRAY_SIZE(server_conf.conf); i++) {
341 		kfree(server_conf.conf[i]);
342 		server_conf.conf[i] = NULL;
343 	}
344 }
345 
346 static int server_conf_init(void)
347 {
348 	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
349 	server_conf.enforced_signing = 0;
350 	server_conf.min_protocol = ksmbd_min_protocol();
351 	server_conf.max_protocol = ksmbd_max_protocol();
352 	server_conf.auth_mechs = KSMBD_AUTH_NTLMSSP;
353 #ifdef CONFIG_SMB_SERVER_KERBEROS5
354 	server_conf.auth_mechs |= KSMBD_AUTH_KRB5 |
355 				KSMBD_AUTH_MSKRB5;
356 #endif
357 	server_conf.max_inflight_req = SMB2_MAX_CREDITS;
358 	return 0;
359 }
360 
361 static void server_ctrl_handle_init(struct server_ctrl_struct *ctrl)
362 {
363 	int ret;
364 
365 	ksmbd_proc_reset();
366 	ret = ksmbd_conn_transport_init();
367 	if (ret) {
368 		server_queue_ctrl_reset_work();
369 		return;
370 	}
371 
372 	pr_info("running\n");
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 	ksmbd_stop_durable_scavenger();
381 	server_conf_free();
382 	server_conf_init();
383 	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
384 }
385 
386 static void server_ctrl_handle_work(struct work_struct *work)
387 {
388 	struct server_ctrl_struct *ctrl;
389 
390 	ctrl = container_of(work, struct server_ctrl_struct, ctrl_work);
391 
392 	mutex_lock(&ctrl_lock);
393 	switch (ctrl->type) {
394 	case SERVER_CTRL_TYPE_INIT:
395 		server_ctrl_handle_init(ctrl);
396 		break;
397 	case SERVER_CTRL_TYPE_RESET:
398 		server_ctrl_handle_reset(ctrl);
399 		break;
400 	default:
401 		pr_err("Unknown server work type: %d\n", ctrl->type);
402 	}
403 	mutex_unlock(&ctrl_lock);
404 	kfree(ctrl);
405 	module_put(THIS_MODULE);
406 }
407 
408 static int __queue_ctrl_work(int type)
409 {
410 	struct server_ctrl_struct *ctrl;
411 
412 	ctrl = kmalloc_obj(struct server_ctrl_struct, KSMBD_DEFAULT_GFP);
413 	if (!ctrl)
414 		return -ENOMEM;
415 
416 	__module_get(THIS_MODULE);
417 	ctrl->type = type;
418 	INIT_WORK(&ctrl->ctrl_work, server_ctrl_handle_work);
419 	queue_work(system_long_wq, &ctrl->ctrl_work);
420 	return 0;
421 }
422 
423 int server_queue_ctrl_init_work(void)
424 {
425 	return __queue_ctrl_work(SERVER_CTRL_TYPE_INIT);
426 }
427 
428 int server_queue_ctrl_reset_work(void)
429 {
430 	return __queue_ctrl_work(SERVER_CTRL_TYPE_RESET);
431 }
432 
433 static ssize_t stats_show(const struct class *class, const struct class_attribute *attr,
434 			  char *buf)
435 {
436 	/*
437 	 * Inc this each time you change stats output format,
438 	 * so user space will know what to do.
439 	 */
440 	static int stats_version = 2;
441 	static const char * const state[] = {
442 		"startup",
443 		"running",
444 		"reset",
445 		"shutdown"
446 	};
447 	return sysfs_emit(buf, "%d %s %d %lu\n", stats_version,
448 			  state[server_conf.state], server_conf.tcp_port,
449 			  server_conf.ipc_last_active / HZ);
450 }
451 
452 static ssize_t kill_server_store(const struct class *class,
453 				 const struct class_attribute *attr, const char *buf,
454 				 size_t len)
455 {
456 	if (!sysfs_streq(buf, "hard"))
457 		return len;
458 
459 	pr_info("kill command received\n");
460 	mutex_lock(&ctrl_lock);
461 	WRITE_ONCE(server_conf.state, SERVER_STATE_RESETTING);
462 	__module_get(THIS_MODULE);
463 	server_ctrl_handle_reset(NULL);
464 	module_put(THIS_MODULE);
465 	mutex_unlock(&ctrl_lock);
466 	return len;
467 }
468 
469 static const char * const debug_type_strings[] = {"smb", "auth", "vfs",
470 						  "oplock", "ipc", "conn",
471 						  "rdma"};
472 
473 static ssize_t debug_show(const struct class *class, const struct class_attribute *attr,
474 			  char *buf)
475 {
476 	ssize_t sz = 0;
477 	int i, pos = 0;
478 
479 	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
480 		if ((ksmbd_debug_types >> i) & 1) {
481 			pos = sysfs_emit_at(buf, sz, "[%s] ", debug_type_strings[i]);
482 		} else {
483 			pos = sysfs_emit_at(buf, sz, "%s ", debug_type_strings[i]);
484 		}
485 		sz += pos;
486 	}
487 	sz += sysfs_emit_at(buf, sz, "\n");
488 	return sz;
489 }
490 
491 static ssize_t debug_store(const struct class *class, const struct class_attribute *attr,
492 			   const char *buf, size_t len)
493 {
494 	int i;
495 
496 	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
497 		if (sysfs_streq(buf, "all")) {
498 			if (ksmbd_debug_types == KSMBD_DEBUG_ALL)
499 				ksmbd_debug_types = 0;
500 			else
501 				ksmbd_debug_types = KSMBD_DEBUG_ALL;
502 			break;
503 		}
504 
505 		if (sysfs_streq(buf, debug_type_strings[i])) {
506 			if (ksmbd_debug_types & (1 << i))
507 				ksmbd_debug_types &= ~(1 << i);
508 			else
509 				ksmbd_debug_types |= (1 << i);
510 			break;
511 		}
512 	}
513 
514 	return len;
515 }
516 
517 static CLASS_ATTR_RO(stats);
518 static CLASS_ATTR_WO(kill_server);
519 static CLASS_ATTR_RW(debug);
520 
521 static struct attribute *ksmbd_control_class_attrs[] = {
522 	&class_attr_stats.attr,
523 	&class_attr_kill_server.attr,
524 	&class_attr_debug.attr,
525 	NULL,
526 };
527 ATTRIBUTE_GROUPS(ksmbd_control_class);
528 
529 static struct class ksmbd_control_class = {
530 	.name		= "ksmbd-control",
531 	.class_groups	= ksmbd_control_class_groups,
532 };
533 
534 static int ksmbd_server_shutdown(void)
535 {
536 	WRITE_ONCE(server_conf.state, SERVER_STATE_SHUTTING_DOWN);
537 
538 	ksmbd_proc_cleanup();
539 	class_unregister(&ksmbd_control_class);
540 	ksmbd_workqueue_destroy();
541 	ksmbd_ipc_release();
542 	ksmbd_conn_transport_destroy();
543 	ksmbd_crypto_destroy();
544 	ksmbd_free_global_file_table();
545 	destroy_lease_table(NULL);
546 	ksmbd_work_pool_destroy();
547 	ksmbd_exit_file_cache();
548 	server_conf_free();
549 	return 0;
550 }
551 
552 static int __init ksmbd_server_init(void)
553 {
554 	int ret;
555 
556 	ret = class_register(&ksmbd_control_class);
557 	if (ret) {
558 		pr_err("Unable to register ksmbd-control class\n");
559 		return ret;
560 	}
561 
562 	ksmbd_proc_init();
563 	create_proc_sessions();
564 
565 	ksmbd_server_tcp_callbacks_init();
566 
567 	ret = server_conf_init();
568 	if (ret)
569 		goto err_unregister;
570 
571 	ret = ksmbd_work_pool_init();
572 	if (ret)
573 		goto err_unregister;
574 
575 	ret = ksmbd_init_file_cache();
576 	if (ret)
577 		goto err_destroy_work_pools;
578 
579 	ret = ksmbd_ipc_init();
580 	if (ret)
581 		goto err_exit_file_cache;
582 
583 	ret = ksmbd_init_global_file_table();
584 	if (ret)
585 		goto err_ipc_release;
586 
587 	ret = ksmbd_inode_hash_init();
588 	if (ret)
589 		goto err_destroy_file_table;
590 
591 	ret = ksmbd_crypto_create();
592 	if (ret)
593 		goto err_release_inode_hash;
594 
595 	ret = ksmbd_workqueue_init();
596 	if (ret)
597 		goto err_crypto_destroy;
598 
599 	return 0;
600 
601 err_crypto_destroy:
602 	ksmbd_crypto_destroy();
603 err_release_inode_hash:
604 	ksmbd_release_inode_hash();
605 err_destroy_file_table:
606 	ksmbd_free_global_file_table();
607 err_ipc_release:
608 	ksmbd_ipc_release();
609 err_exit_file_cache:
610 	ksmbd_exit_file_cache();
611 err_destroy_work_pools:
612 	ksmbd_work_pool_destroy();
613 err_unregister:
614 	class_unregister(&ksmbd_control_class);
615 
616 	return ret;
617 }
618 
619 /**
620  * ksmbd_server_exit() - shutdown forker thread and free memory at module exit
621  */
622 static void __exit ksmbd_server_exit(void)
623 {
624 	ksmbd_server_shutdown();
625 	rcu_barrier();
626 	ksmbd_release_inode_hash();
627 }
628 
629 MODULE_AUTHOR("Namjae Jeon <linkinjeon@kernel.org>");
630 MODULE_DESCRIPTION("Linux kernel CIFS/SMB SERVER");
631 MODULE_LICENSE("GPL");
632 MODULE_SOFTDEP("pre: ecb");
633 MODULE_SOFTDEP("pre: nls");
634 MODULE_SOFTDEP("pre: aes");
635 MODULE_SOFTDEP("pre: cmac");
636 MODULE_SOFTDEP("pre: aead2");
637 MODULE_SOFTDEP("pre: ccm");
638 MODULE_SOFTDEP("pre: gcm");
639 module_init(ksmbd_server_init)
640 module_exit(ksmbd_server_exit)
641