xref: /linux/fs/smb/server/server.c (revision 59e6295fac26b8e85c1ea859cdd89fa1e47519d7)
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 #include "compress.h"
26 
27 int ksmbd_debug_types;
28 
29 struct ksmbd_server_config server_conf;
30 
31 enum SERVER_CTRL_TYPE {
32 	SERVER_CTRL_TYPE_INIT,
33 	SERVER_CTRL_TYPE_RESET,
34 };
35 
36 struct server_ctrl_struct {
37 	int			type;
38 	struct work_struct	ctrl_work;
39 };
40 
41 static DEFINE_MUTEX(ctrl_lock);
42 
43 static int ___server_conf_set(int idx, char *val)
44 {
45 	if (idx >= ARRAY_SIZE(server_conf.conf))
46 		return -EINVAL;
47 
48 	if (!val || val[0] == 0x00)
49 		return -EINVAL;
50 
51 	kfree(server_conf.conf[idx]);
52 	server_conf.conf[idx] = kstrdup(val, KSMBD_DEFAULT_GFP);
53 	if (!server_conf.conf[idx])
54 		return -ENOMEM;
55 	return 0;
56 }
57 
58 int ksmbd_set_netbios_name(char *v)
59 {
60 	return ___server_conf_set(SERVER_CONF_NETBIOS_NAME, v);
61 }
62 
63 int ksmbd_set_server_string(char *v)
64 {
65 	return ___server_conf_set(SERVER_CONF_SERVER_STRING, v);
66 }
67 
68 int ksmbd_set_work_group(char *v)
69 {
70 	return ___server_conf_set(SERVER_CONF_WORK_GROUP, v);
71 }
72 
73 char *ksmbd_netbios_name(void)
74 {
75 	return server_conf.conf[SERVER_CONF_NETBIOS_NAME];
76 }
77 
78 char *ksmbd_server_string(void)
79 {
80 	return server_conf.conf[SERVER_CONF_SERVER_STRING];
81 }
82 
83 char *ksmbd_work_group(void)
84 {
85 	return server_conf.conf[SERVER_CONF_WORK_GROUP];
86 }
87 
88 /**
89  * check_conn_state() - check state of server thread connection
90  * @work:     smb work containing server thread information
91  *
92  * Return:	0 on valid connection, otherwise 1 to reconnect
93  */
94 static inline int check_conn_state(struct ksmbd_work *work)
95 {
96 	struct smb_hdr *rsp_hdr;
97 
98 	if (ksmbd_conn_exiting(work->conn) ||
99 	    ksmbd_conn_need_reconnect(work->conn)) {
100 		rsp_hdr = smb_get_msg(work->response_buf);
101 		rsp_hdr->Status.CifsError = STATUS_CONNECTION_DISCONNECTED;
102 		return 1;
103 	}
104 	return 0;
105 }
106 
107 #define SERVER_HANDLER_CONTINUE		0
108 #define SERVER_HANDLER_ABORT		1
109 
110 static int __process_request(struct ksmbd_work *work, struct ksmbd_conn *conn,
111 			     u16 *cmd)
112 {
113 	struct smb_version_cmds *cmds;
114 	u16 command;
115 	bool signed_req;
116 	int ret;
117 
118 	if (check_conn_state(work))
119 		return SERVER_HANDLER_CONTINUE;
120 
121 	if (ksmbd_verify_smb_message(work)) {
122 		conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER);
123 		return SERVER_HANDLER_ABORT;
124 	}
125 
126 	command = conn->ops->get_cmd_val(work);
127 	*cmd = command;
128 
129 andx_again:
130 	if (command >= conn->max_cmds) {
131 		conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER);
132 		return SERVER_HANDLER_ABORT;
133 	}
134 
135 	cmds = &conn->cmds[command];
136 	if (!cmds->proc) {
137 		ksmbd_debug(SMB, "*** not implemented yet cmd = %x\n", command);
138 		conn->ops->set_rsp_status(work, STATUS_NOT_IMPLEMENTED);
139 		return SERVER_HANDLER_ABORT;
140 	}
141 
142 	signed_req = conn->ops->is_sign_req && conn->ops->is_sign_req(work, command);
143 	if (work->sess && work->sess->sign && !work->encrypted &&
144 	    !signed_req) {
145 		conn->ops->set_rsp_status(work, STATUS_ACCESS_DENIED);
146 		return SERVER_HANDLER_ABORT;
147 	}
148 
149 	if (work->sess && signed_req) {
150 		ret = conn->ops->check_sign_req(work);
151 		if (!ret) {
152 			conn->ops->set_rsp_status(work, STATUS_ACCESS_DENIED);
153 			return SERVER_HANDLER_ABORT;
154 		}
155 	}
156 
157 	ret = cmds->proc(work);
158 	if (conn->ops->inc_reqs)
159 		conn->ops->inc_reqs(command);
160 
161 	if (ret < 0)
162 		ksmbd_debug(CONN, "Failed to process %u [%d]\n", command, ret);
163 	/* AndX commands - chained request can return positive values */
164 	else if (ret > 0) {
165 		command = ret;
166 		*cmd = command;
167 		goto andx_again;
168 	}
169 
170 	if (work->send_no_response)
171 		return SERVER_HANDLER_ABORT;
172 	return SERVER_HANDLER_CONTINUE;
173 }
174 
175 static void __handle_ksmbd_work(struct ksmbd_work *work,
176 				struct ksmbd_conn *conn)
177 {
178 	u16 command = 0;
179 	int rc;
180 	bool is_chained = false;
181 
182 	if (conn->ops->is_transform_hdr &&
183 	    conn->ops->is_transform_hdr(work->request_buf)) {
184 		rc = conn->ops->decrypt_req(work);
185 		if (rc < 0)
186 			return;
187 		work->encrypted = true;
188 	}
189 
190 	if (conn->ops->allocate_rsp_buf(work))
191 		return;
192 
193 	rc = conn->ops->init_rsp_hdr(work);
194 	if (rc) {
195 		/* either uid or tid is not correct */
196 		conn->ops->set_rsp_status(work, STATUS_INVALID_HANDLE);
197 		goto send;
198 	}
199 
200 	do {
201 		if (conn->ops->check_user_session) {
202 			rc = conn->ops->check_user_session(work);
203 			if (rc < 0) {
204 				if (rc == -EINVAL)
205 					conn->ops->set_rsp_status(work,
206 						STATUS_INVALID_PARAMETER);
207 				else
208 					conn->ops->set_rsp_status(work,
209 						STATUS_USER_SESSION_DELETED);
210 				if (conn->ops->is_sign_req(work, conn->ops->get_cmd_val(work))) {
211 					struct smb2_hdr *rsp_hdr;
212 
213 					rsp_hdr = ksmbd_resp_buf_curr(work);
214 					rsp_hdr->Flags |= SMB2_FLAGS_SIGNED;
215 				}
216 				goto send;
217 			} else if (rc > 0) {
218 				rc = conn->ops->get_ksmbd_tcon(work);
219 				if (rc < 0) {
220 					if (rc == -EINVAL)
221 						conn->ops->set_rsp_status(work,
222 							STATUS_INVALID_PARAMETER);
223 					else
224 						conn->ops->set_rsp_status(work,
225 							STATUS_NETWORK_NAME_DELETED);
226 					goto send;
227 				}
228 			}
229 		}
230 
231 		rc = __process_request(work, conn, &command);
232 		if (rc == SERVER_HANDLER_ABORT)
233 			break;
234 
235 		/*
236 		 * Call smb2_set_rsp_credits() function to set number of credits
237 		 * granted in hdr of smb2 response.
238 		 */
239 		if (conn->ops->set_rsp_credits) {
240 			spin_lock(&conn->credits_lock);
241 			rc = conn->ops->set_rsp_credits(work);
242 			spin_unlock(&conn->credits_lock);
243 			if (rc < 0) {
244 				conn->ops->set_rsp_status(work,
245 					STATUS_INVALID_PARAMETER);
246 				goto send;
247 			}
248 		}
249 
250 		is_chained = is_chained_smb2_message(work);
251 
252 		if (work->sess &&
253 		    (work->sess->sign || smb3_11_final_sess_setup_resp(work) ||
254 		     conn->ops->is_sign_req(work, command))) {
255 			if (command == SMB2_SESSION_SETUP_HE &&
256 			    work->sess->dialect >= SMB30_PROT_ID &&
257 			    conn->dialect < SMB30_PROT_ID)
258 				smb3_set_sign_rsp(work);
259 			else
260 				conn->ops->set_sign_rsp(work);
261 		}
262 	} while (is_chained == true);
263 
264 send:
265 	/*
266 	 * Release any credit charge still outstanding for this request.  On
267 	 * the normal path smb2_set_rsp_credits() already returned it, but the
268 	 * abort, error and send-no-response paths skip that call, so the
269 	 * charge would otherwise leak and eventually exhaust the connection's
270 	 * outstanding credit window.
271 	 */
272 	if (work->credit_charge) {
273 		spin_lock(&conn->credits_lock);
274 		conn->outstanding_credits -= work->credit_charge;
275 		work->credit_charge = 0;
276 		spin_unlock(&conn->credits_lock);
277 	}
278 
279 	if (work->tcon)
280 		ksmbd_tree_connect_put(work->tcon);
281 	smb3_preauth_hash_rsp(work);
282 	/*
283 	 * Preauthentication hashes cover the original SMB2 response. Apply the
284 	 * transport compression wrapper only after updating the hash.
285 	 */
286 	if (work->compress_response) {
287 		rc = ksmbd_compress_response(work);
288 		if (rc < 0)
289 			ksmbd_debug(CONN, "Failed to compress response: %d\n", rc);
290 	}
291 	if (work->sess && work->sess->enc && work->encrypted &&
292 	    conn->ops->encrypt_resp) {
293 		rc = conn->ops->encrypt_resp(work);
294 		if (rc < 0)
295 			conn->ops->set_rsp_status(work, STATUS_DATA_ERROR);
296 	}
297 	if (work->sess)
298 		ksmbd_user_session_put(work->sess);
299 
300 	ksmbd_conn_write(work);
301 }
302 
303 /**
304  * handle_ksmbd_work() - process pending smb work requests
305  * @wk:	smb work containing request command buffer
306  *
307  * called by kworker threads to processing remaining smb work requests
308  */
309 static void handle_ksmbd_work(struct work_struct *wk)
310 {
311 	struct ksmbd_work *work = container_of(wk, struct ksmbd_work, work);
312 	struct ksmbd_conn *conn = work->conn;
313 
314 	atomic64_inc(&conn->stats.request_served);
315 
316 	__handle_ksmbd_work(work, conn);
317 
318 	ksmbd_conn_try_dequeue_request(work);
319 	ksmbd_free_work_struct(work);
320 	ksmbd_conn_r_count_dec(conn);
321 }
322 
323 /**
324  * queue_ksmbd_work() - queue a smb request to worker thread queue
325  *		for processing smb command and sending response
326  * @conn:	connection instance
327  *
328  * read remaining data from socket create and submit work.
329  */
330 static int queue_ksmbd_work(struct ksmbd_conn *conn)
331 {
332 	struct ksmbd_work *work;
333 	int err;
334 
335 	err = ksmbd_init_smb_server(conn);
336 	if (err)
337 		return 0;
338 
339 	work = ksmbd_alloc_work_struct();
340 	if (!work) {
341 		pr_err("allocation for work failed\n");
342 		return -ENOMEM;
343 	}
344 
345 	work->conn = conn;
346 	work->request_buf = conn->request_buf;
347 	conn->request_buf = NULL;
348 
349 	ksmbd_conn_enqueue_request(work);
350 	ksmbd_conn_r_count_inc(conn);
351 	/* update activity on connection */
352 	conn->last_active = jiffies;
353 	INIT_WORK(&work->work, handle_ksmbd_work);
354 	ksmbd_queue_work(work);
355 	return 0;
356 }
357 
358 static int ksmbd_server_process_request(struct ksmbd_conn *conn)
359 {
360 	return queue_ksmbd_work(conn);
361 }
362 
363 static int ksmbd_server_terminate_conn(struct ksmbd_conn *conn)
364 {
365 	ksmbd_sessions_deregister(conn);
366 	destroy_lease_table(conn);
367 	return 0;
368 }
369 
370 static void ksmbd_server_tcp_callbacks_init(void)
371 {
372 	struct ksmbd_conn_ops ops;
373 
374 	ops.process_fn = ksmbd_server_process_request;
375 	ops.terminate_fn = ksmbd_server_terminate_conn;
376 
377 	ksmbd_conn_init_server_callbacks(&ops);
378 }
379 
380 static void server_conf_free(void)
381 {
382 	int i;
383 
384 	for (i = 0; i < ARRAY_SIZE(server_conf.conf); i++) {
385 		kfree(server_conf.conf[i]);
386 		server_conf.conf[i] = NULL;
387 	}
388 }
389 
390 static int server_conf_init(void)
391 {
392 	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
393 	server_conf.enforced_signing = 0;
394 	server_conf.min_protocol = ksmbd_min_protocol();
395 	server_conf.max_protocol = ksmbd_max_protocol();
396 	server_conf.auth_mechs = KSMBD_AUTH_NTLMSSP;
397 #ifdef CONFIG_SMB_SERVER_KERBEROS5
398 	server_conf.auth_mechs |= KSMBD_AUTH_KRB5 |
399 				KSMBD_AUTH_MSKRB5;
400 #endif
401 	server_conf.max_inflight_req = SMB2_MAX_CREDITS;
402 	return 0;
403 }
404 
405 static void server_ctrl_handle_init(struct server_ctrl_struct *ctrl)
406 {
407 	int ret;
408 
409 	ksmbd_proc_reset();
410 	ret = ksmbd_conn_transport_init();
411 	if (ret) {
412 		server_queue_ctrl_reset_work();
413 		return;
414 	}
415 
416 	pr_info("running\n");
417 	WRITE_ONCE(server_conf.state, SERVER_STATE_RUNNING);
418 }
419 
420 static void server_ctrl_handle_reset(struct server_ctrl_struct *ctrl)
421 {
422 	ksmbd_ipc_soft_reset();
423 	ksmbd_conn_transport_destroy();
424 	ksmbd_stop_durable_scavenger();
425 	server_conf_free();
426 	server_conf_init();
427 	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
428 }
429 
430 static void server_ctrl_handle_work(struct work_struct *work)
431 {
432 	struct server_ctrl_struct *ctrl;
433 
434 	ctrl = container_of(work, struct server_ctrl_struct, ctrl_work);
435 
436 	mutex_lock(&ctrl_lock);
437 	switch (ctrl->type) {
438 	case SERVER_CTRL_TYPE_INIT:
439 		server_ctrl_handle_init(ctrl);
440 		break;
441 	case SERVER_CTRL_TYPE_RESET:
442 		server_ctrl_handle_reset(ctrl);
443 		break;
444 	default:
445 		pr_err("Unknown server work type: %d\n", ctrl->type);
446 	}
447 	mutex_unlock(&ctrl_lock);
448 	kfree(ctrl);
449 	module_put(THIS_MODULE);
450 }
451 
452 static int __queue_ctrl_work(int type)
453 {
454 	struct server_ctrl_struct *ctrl;
455 
456 	ctrl = kmalloc_obj(struct server_ctrl_struct, KSMBD_DEFAULT_GFP);
457 	if (!ctrl)
458 		return -ENOMEM;
459 
460 	__module_get(THIS_MODULE);
461 	ctrl->type = type;
462 	INIT_WORK(&ctrl->ctrl_work, server_ctrl_handle_work);
463 	queue_work(system_long_wq, &ctrl->ctrl_work);
464 	return 0;
465 }
466 
467 int server_queue_ctrl_init_work(void)
468 {
469 	return __queue_ctrl_work(SERVER_CTRL_TYPE_INIT);
470 }
471 
472 int server_queue_ctrl_reset_work(void)
473 {
474 	return __queue_ctrl_work(SERVER_CTRL_TYPE_RESET);
475 }
476 
477 static ssize_t stats_show(const struct class *class, const struct class_attribute *attr,
478 			  char *buf)
479 {
480 	/*
481 	 * Inc this each time you change stats output format,
482 	 * so user space will know what to do.
483 	 */
484 	static int stats_version = 2;
485 	static const char * const state[] = {
486 		"startup",
487 		"running",
488 		"reset",
489 		"shutdown"
490 	};
491 	return sysfs_emit(buf, "%d %s %d %lu\n", stats_version,
492 			  state[server_conf.state], server_conf.tcp_port,
493 			  server_conf.ipc_last_active / HZ);
494 }
495 
496 static ssize_t kill_server_store(const struct class *class,
497 				 const struct class_attribute *attr, const char *buf,
498 				 size_t len)
499 {
500 	if (!sysfs_streq(buf, "hard"))
501 		return len;
502 
503 	pr_info("kill command received\n");
504 	mutex_lock(&ctrl_lock);
505 	WRITE_ONCE(server_conf.state, SERVER_STATE_RESETTING);
506 	__module_get(THIS_MODULE);
507 	server_ctrl_handle_reset(NULL);
508 	module_put(THIS_MODULE);
509 	mutex_unlock(&ctrl_lock);
510 	return len;
511 }
512 
513 static const char * const debug_type_strings[] = {"smb", "auth", "vfs",
514 						  "oplock", "ipc", "conn",
515 						  "rdma"};
516 
517 static ssize_t debug_show(const struct class *class, const struct class_attribute *attr,
518 			  char *buf)
519 {
520 	ssize_t sz = 0;
521 	int i, pos = 0;
522 
523 	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
524 		if ((ksmbd_debug_types >> i) & 1) {
525 			pos = sysfs_emit_at(buf, sz, "[%s] ", debug_type_strings[i]);
526 		} else {
527 			pos = sysfs_emit_at(buf, sz, "%s ", debug_type_strings[i]);
528 		}
529 		sz += pos;
530 	}
531 	sz += sysfs_emit_at(buf, sz, "\n");
532 	return sz;
533 }
534 
535 static ssize_t debug_store(const struct class *class, const struct class_attribute *attr,
536 			   const char *buf, size_t len)
537 {
538 	int i;
539 
540 	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
541 		if (sysfs_streq(buf, "all")) {
542 			if (ksmbd_debug_types == KSMBD_DEBUG_ALL)
543 				ksmbd_debug_types = 0;
544 			else
545 				ksmbd_debug_types = KSMBD_DEBUG_ALL;
546 			break;
547 		}
548 
549 		if (sysfs_streq(buf, debug_type_strings[i])) {
550 			if (ksmbd_debug_types & (1 << i))
551 				ksmbd_debug_types &= ~(1 << i);
552 			else
553 				ksmbd_debug_types |= (1 << i);
554 			break;
555 		}
556 	}
557 
558 	return len;
559 }
560 
561 static CLASS_ATTR_RO(stats);
562 static CLASS_ATTR_WO(kill_server);
563 static CLASS_ATTR_RW(debug);
564 
565 static struct attribute *ksmbd_control_class_attrs[] = {
566 	&class_attr_stats.attr,
567 	&class_attr_kill_server.attr,
568 	&class_attr_debug.attr,
569 	NULL,
570 };
571 ATTRIBUTE_GROUPS(ksmbd_control_class);
572 
573 static struct class ksmbd_control_class = {
574 	.name		= "ksmbd-control",
575 	.class_groups	= ksmbd_control_class_groups,
576 };
577 
578 static int ksmbd_server_shutdown(void)
579 {
580 	WRITE_ONCE(server_conf.state, SERVER_STATE_SHUTTING_DOWN);
581 
582 	ksmbd_proc_cleanup();
583 	class_unregister(&ksmbd_control_class);
584 	ksmbd_workqueue_destroy();
585 	ksmbd_ipc_release();
586 	ksmbd_conn_transport_destroy();
587 	ksmbd_crypto_destroy();
588 	ksmbd_free_global_file_table();
589 	destroy_lease_table(NULL);
590 	ksmbd_work_pool_destroy();
591 	ksmbd_exit_file_cache();
592 	server_conf_free();
593 	return 0;
594 }
595 
596 static int __init ksmbd_server_init(void)
597 {
598 	int ret;
599 
600 	ret = class_register(&ksmbd_control_class);
601 	if (ret) {
602 		pr_err("Unable to register ksmbd-control class\n");
603 		return ret;
604 	}
605 
606 	ksmbd_proc_init();
607 	create_proc_sessions();
608 
609 	ksmbd_server_tcp_callbacks_init();
610 
611 	ret = server_conf_init();
612 	if (ret)
613 		goto err_unregister;
614 
615 	ret = ksmbd_work_pool_init();
616 	if (ret)
617 		goto err_unregister;
618 
619 	ret = ksmbd_init_file_cache();
620 	if (ret)
621 		goto err_destroy_work_pools;
622 
623 	ret = ksmbd_ipc_init();
624 	if (ret)
625 		goto err_exit_file_cache;
626 
627 	ret = ksmbd_init_global_file_table();
628 	if (ret)
629 		goto err_ipc_release;
630 
631 	ret = ksmbd_inode_hash_init();
632 	if (ret)
633 		goto err_destroy_file_table;
634 
635 	ret = ksmbd_crypto_create();
636 	if (ret)
637 		goto err_release_inode_hash;
638 
639 	ret = ksmbd_workqueue_init();
640 	if (ret)
641 		goto err_crypto_destroy;
642 
643 	ret = ksmbd_conn_wq_init();
644 	if (ret)
645 		goto err_workqueue_destroy;
646 
647 	return 0;
648 
649 err_workqueue_destroy:
650 	ksmbd_workqueue_destroy();
651 err_crypto_destroy:
652 	ksmbd_crypto_destroy();
653 err_release_inode_hash:
654 	ksmbd_release_inode_hash();
655 err_destroy_file_table:
656 	ksmbd_free_global_file_table();
657 err_ipc_release:
658 	ksmbd_ipc_release();
659 err_exit_file_cache:
660 	ksmbd_exit_file_cache();
661 err_destroy_work_pools:
662 	ksmbd_work_pool_destroy();
663 err_unregister:
664 	class_unregister(&ksmbd_control_class);
665 
666 	return ret;
667 }
668 
669 /**
670  * ksmbd_server_exit() - shutdown forker thread and free memory at module exit
671  */
672 static void __exit ksmbd_server_exit(void)
673 {
674 	ksmbd_server_shutdown();
675 	rcu_barrier();
676 	/*
677 	 * ksmbd_conn_put() defers the final release onto ksmbd_conn_wq,
678 	 * so drain it after rcu_barrier() has fired any pending RCU
679 	 * callbacks that may have queued a release.
680 	 */
681 	ksmbd_conn_wq_destroy();
682 	ksmbd_release_inode_hash();
683 }
684 
685 MODULE_AUTHOR("Namjae Jeon <linkinjeon@kernel.org>");
686 MODULE_DESCRIPTION("Linux kernel CIFS/SMB SERVER");
687 MODULE_LICENSE("GPL");
688 MODULE_SOFTDEP("pre: nls");
689 MODULE_SOFTDEP("pre: aes");
690 MODULE_SOFTDEP("pre: aead2");
691 MODULE_SOFTDEP("pre: ccm");
692 MODULE_SOFTDEP("pre: gcm");
693 module_init(ksmbd_server_init)
694 module_exit(ksmbd_server_exit)
695