xref: /openbmc/linux/fs/smb/server/server.c (revision 71a15258f3c92eb1c4ae98bbfca9459f4723d5d3)
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)
245 		ksmbd_user_session_put(work->sess);
246 	if (work->sess && work->sess->enc && work->encrypted &&
247 	    conn->ops->encrypt_resp) {
248 		rc = conn->ops->encrypt_resp(work);
249 		if (rc < 0)
250 			conn->ops->set_rsp_status(work, STATUS_DATA_ERROR);
251 	}
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  */
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 	atomic_dec(&conn->mux_smb_requests);
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 	atomic_inc(&conn->refcnt);
280 	if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q))
281 		wake_up(&conn->r_count_q);
282 
283 	if (atomic_dec_and_test(&conn->refcnt))
284 		kfree(conn);
285 }
286 
287 /**
288  * queue_ksmbd_work() - queue a smb request to worker thread queue
289  *		for proccessing smb command and sending response
290  * @conn:	connection instance
291  *
292  * read remaining data from socket create and submit work.
293  */
294 static int queue_ksmbd_work(struct ksmbd_conn *conn)
295 {
296 	struct ksmbd_work *work;
297 	int err;
298 
299 	err = ksmbd_init_smb_server(conn);
300 	if (err)
301 		return 0;
302 
303 	if (atomic_inc_return(&conn->mux_smb_requests) >= conn->vals->max_credits) {
304 		atomic_dec_return(&conn->mux_smb_requests);
305 		return -ENOSPC;
306 	}
307 
308 	work = ksmbd_alloc_work_struct();
309 	if (!work) {
310 		pr_err("allocation for work failed\n");
311 		return -ENOMEM;
312 	}
313 
314 	work->conn = conn;
315 	work->request_buf = conn->request_buf;
316 	conn->request_buf = NULL;
317 
318 	ksmbd_conn_enqueue_request(work);
319 	atomic_inc(&conn->r_count);
320 	/* update activity on connection */
321 	conn->last_active = jiffies;
322 	INIT_WORK(&work->work, handle_ksmbd_work);
323 	ksmbd_queue_work(work);
324 	return 0;
325 }
326 
327 static int ksmbd_server_process_request(struct ksmbd_conn *conn)
328 {
329 	return queue_ksmbd_work(conn);
330 }
331 
332 static int ksmbd_server_terminate_conn(struct ksmbd_conn *conn)
333 {
334 	ksmbd_sessions_deregister(conn);
335 	destroy_lease_table(conn);
336 	return 0;
337 }
338 
339 static void ksmbd_server_tcp_callbacks_init(void)
340 {
341 	struct ksmbd_conn_ops ops;
342 
343 	ops.process_fn = ksmbd_server_process_request;
344 	ops.terminate_fn = ksmbd_server_terminate_conn;
345 
346 	ksmbd_conn_init_server_callbacks(&ops);
347 }
348 
349 static void server_conf_free(void)
350 {
351 	int i;
352 
353 	for (i = 0; i < ARRAY_SIZE(server_conf.conf); i++) {
354 		kfree(server_conf.conf[i]);
355 		server_conf.conf[i] = NULL;
356 	}
357 }
358 
359 static int server_conf_init(void)
360 {
361 	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
362 	server_conf.enforced_signing = 0;
363 	server_conf.min_protocol = ksmbd_min_protocol();
364 	server_conf.max_protocol = ksmbd_max_protocol();
365 	server_conf.auth_mechs = KSMBD_AUTH_NTLMSSP;
366 #ifdef CONFIG_SMB_SERVER_KERBEROS5
367 	server_conf.auth_mechs |= KSMBD_AUTH_KRB5 |
368 				KSMBD_AUTH_MSKRB5;
369 #endif
370 	return 0;
371 }
372 
373 static void server_ctrl_handle_init(struct server_ctrl_struct *ctrl)
374 {
375 	int ret;
376 
377 	ret = ksmbd_conn_transport_init();
378 	if (ret) {
379 		server_queue_ctrl_reset_work();
380 		return;
381 	}
382 
383 	WRITE_ONCE(server_conf.state, SERVER_STATE_RUNNING);
384 }
385 
386 static void server_ctrl_handle_reset(struct server_ctrl_struct *ctrl)
387 {
388 	ksmbd_ipc_soft_reset();
389 	ksmbd_conn_transport_destroy();
390 	server_conf_free();
391 	server_conf_init();
392 	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
393 }
394 
395 static void server_ctrl_handle_work(struct work_struct *work)
396 {
397 	struct server_ctrl_struct *ctrl;
398 
399 	ctrl = container_of(work, struct server_ctrl_struct, ctrl_work);
400 
401 	mutex_lock(&ctrl_lock);
402 	switch (ctrl->type) {
403 	case SERVER_CTRL_TYPE_INIT:
404 		server_ctrl_handle_init(ctrl);
405 		break;
406 	case SERVER_CTRL_TYPE_RESET:
407 		server_ctrl_handle_reset(ctrl);
408 		break;
409 	default:
410 		pr_err("Unknown server work type: %d\n", ctrl->type);
411 	}
412 	mutex_unlock(&ctrl_lock);
413 	kfree(ctrl);
414 	module_put(THIS_MODULE);
415 }
416 
417 static int __queue_ctrl_work(int type)
418 {
419 	struct server_ctrl_struct *ctrl;
420 
421 	ctrl = kmalloc(sizeof(struct server_ctrl_struct), GFP_KERNEL);
422 	if (!ctrl)
423 		return -ENOMEM;
424 
425 	__module_get(THIS_MODULE);
426 	ctrl->type = type;
427 	INIT_WORK(&ctrl->ctrl_work, server_ctrl_handle_work);
428 	queue_work(system_long_wq, &ctrl->ctrl_work);
429 	return 0;
430 }
431 
432 int server_queue_ctrl_init_work(void)
433 {
434 	return __queue_ctrl_work(SERVER_CTRL_TYPE_INIT);
435 }
436 
437 int server_queue_ctrl_reset_work(void)
438 {
439 	return __queue_ctrl_work(SERVER_CTRL_TYPE_RESET);
440 }
441 
442 static ssize_t stats_show(const struct class *class, const struct class_attribute *attr,
443 			  char *buf)
444 {
445 	/*
446 	 * Inc this each time you change stats output format,
447 	 * so user space will know what to do.
448 	 */
449 	static int stats_version = 2;
450 	static const char * const state[] = {
451 		"startup",
452 		"running",
453 		"reset",
454 		"shutdown"
455 	};
456 	return sysfs_emit(buf, "%d %s %d %lu\n", stats_version,
457 			  state[server_conf.state], server_conf.tcp_port,
458 			  server_conf.ipc_last_active / HZ);
459 }
460 
461 static ssize_t kill_server_store(const struct class *class,
462 				 const struct class_attribute *attr, const char *buf,
463 				 size_t len)
464 {
465 	if (!sysfs_streq(buf, "hard"))
466 		return len;
467 
468 	pr_info("kill command received\n");
469 	mutex_lock(&ctrl_lock);
470 	WRITE_ONCE(server_conf.state, SERVER_STATE_RESETTING);
471 	__module_get(THIS_MODULE);
472 	server_ctrl_handle_reset(NULL);
473 	module_put(THIS_MODULE);
474 	mutex_unlock(&ctrl_lock);
475 	return len;
476 }
477 
478 static const char * const debug_type_strings[] = {"smb", "auth", "vfs",
479 						  "oplock", "ipc", "conn",
480 						  "rdma"};
481 
482 static ssize_t debug_show(const struct class *class, const struct class_attribute *attr,
483 			  char *buf)
484 {
485 	ssize_t sz = 0;
486 	int i, pos = 0;
487 
488 	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
489 		if ((ksmbd_debug_types >> i) & 1) {
490 			pos = sysfs_emit_at(buf, sz, "[%s] ", debug_type_strings[i]);
491 		} else {
492 			pos = sysfs_emit_at(buf, sz, "%s ", debug_type_strings[i]);
493 		}
494 		sz += pos;
495 	}
496 	sz += sysfs_emit_at(buf, sz, "\n");
497 	return sz;
498 }
499 
500 static ssize_t debug_store(const struct class *class, const struct class_attribute *attr,
501 			   const char *buf, size_t len)
502 {
503 	int i;
504 
505 	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
506 		if (sysfs_streq(buf, "all")) {
507 			if (ksmbd_debug_types == KSMBD_DEBUG_ALL)
508 				ksmbd_debug_types = 0;
509 			else
510 				ksmbd_debug_types = KSMBD_DEBUG_ALL;
511 			break;
512 		}
513 
514 		if (sysfs_streq(buf, debug_type_strings[i])) {
515 			if (ksmbd_debug_types & (1 << i))
516 				ksmbd_debug_types &= ~(1 << i);
517 			else
518 				ksmbd_debug_types |= (1 << i);
519 			break;
520 		}
521 	}
522 
523 	return len;
524 }
525 
526 static CLASS_ATTR_RO(stats);
527 static CLASS_ATTR_WO(kill_server);
528 static CLASS_ATTR_RW(debug);
529 
530 static struct attribute *ksmbd_control_class_attrs[] = {
531 	&class_attr_stats.attr,
532 	&class_attr_kill_server.attr,
533 	&class_attr_debug.attr,
534 	NULL,
535 };
536 ATTRIBUTE_GROUPS(ksmbd_control_class);
537 
538 static struct class ksmbd_control_class = {
539 	.name		= "ksmbd-control",
540 	.class_groups	= ksmbd_control_class_groups,
541 };
542 
543 static int ksmbd_server_shutdown(void)
544 {
545 	WRITE_ONCE(server_conf.state, SERVER_STATE_SHUTTING_DOWN);
546 
547 	class_unregister(&ksmbd_control_class);
548 	ksmbd_workqueue_destroy();
549 	ksmbd_ipc_release();
550 	ksmbd_conn_transport_destroy();
551 	ksmbd_crypto_destroy();
552 	ksmbd_free_global_file_table();
553 	destroy_lease_table(NULL);
554 	ksmbd_work_pool_destroy();
555 	ksmbd_exit_file_cache();
556 	server_conf_free();
557 	return 0;
558 }
559 
560 static int __init ksmbd_server_init(void)
561 {
562 	int ret;
563 
564 	ret = class_register(&ksmbd_control_class);
565 	if (ret) {
566 		pr_err("Unable to register ksmbd-control class\n");
567 		return ret;
568 	}
569 
570 	ksmbd_server_tcp_callbacks_init();
571 
572 	ret = server_conf_init();
573 	if (ret)
574 		goto err_unregister;
575 
576 	ret = ksmbd_work_pool_init();
577 	if (ret)
578 		goto err_unregister;
579 
580 	ret = ksmbd_init_file_cache();
581 	if (ret)
582 		goto err_destroy_work_pools;
583 
584 	ret = ksmbd_ipc_init();
585 	if (ret)
586 		goto err_exit_file_cache;
587 
588 	ret = ksmbd_init_global_file_table();
589 	if (ret)
590 		goto err_ipc_release;
591 
592 	ret = ksmbd_inode_hash_init();
593 	if (ret)
594 		goto err_destroy_file_table;
595 
596 	ret = ksmbd_crypto_create();
597 	if (ret)
598 		goto err_release_inode_hash;
599 
600 	ret = ksmbd_workqueue_init();
601 	if (ret)
602 		goto err_crypto_destroy;
603 
604 	return 0;
605 
606 err_crypto_destroy:
607 	ksmbd_crypto_destroy();
608 err_release_inode_hash:
609 	ksmbd_release_inode_hash();
610 err_destroy_file_table:
611 	ksmbd_free_global_file_table();
612 err_ipc_release:
613 	ksmbd_ipc_release();
614 err_exit_file_cache:
615 	ksmbd_exit_file_cache();
616 err_destroy_work_pools:
617 	ksmbd_work_pool_destroy();
618 err_unregister:
619 	class_unregister(&ksmbd_control_class);
620 
621 	return ret;
622 }
623 
624 /**
625  * ksmbd_server_exit() - shutdown forker thread and free memory at module exit
626  */
627 static void __exit ksmbd_server_exit(void)
628 {
629 	ksmbd_server_shutdown();
630 	rcu_barrier();
631 	ksmbd_release_inode_hash();
632 }
633 
634 MODULE_AUTHOR("Namjae Jeon <linkinjeon@kernel.org>");
635 MODULE_VERSION(KSMBD_VERSION);
636 MODULE_DESCRIPTION("Linux kernel CIFS/SMB SERVER");
637 MODULE_LICENSE("GPL");
638 MODULE_SOFTDEP("pre: ecb");
639 MODULE_SOFTDEP("pre: hmac");
640 MODULE_SOFTDEP("pre: md5");
641 MODULE_SOFTDEP("pre: nls");
642 MODULE_SOFTDEP("pre: aes");
643 MODULE_SOFTDEP("pre: cmac");
644 MODULE_SOFTDEP("pre: sha256");
645 MODULE_SOFTDEP("pre: sha512");
646 MODULE_SOFTDEP("pre: aead2");
647 MODULE_SOFTDEP("pre: ccm");
648 MODULE_SOFTDEP("pre: gcm");
649 MODULE_SOFTDEP("pre: crc32");
650 module_init(ksmbd_server_init)
651 module_exit(ksmbd_server_exit)
652