xref: /openbmc/linux/fs/smb/server/server.c (revision e909258d)
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->sess)
242 		ksmbd_user_session_put(work->sess);
243 	if (work->tcon)
244 		ksmbd_tree_connect_put(work->tcon);
245 	smb3_preauth_hash_rsp(work);
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 	/*
274 	 * Checking waitqueue to dropping pending requests on
275 	 * disconnection. waitqueue_active is safe because it
276 	 * uses atomic operation for condition.
277 	 */
278 	if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q))
279 		wake_up(&conn->r_count_q);
280 }
281 
282 /**
283  * queue_ksmbd_work() - queue a smb request to worker thread queue
284  *		for proccessing smb command and sending response
285  * @conn:	connection instance
286  *
287  * read remaining data from socket create and submit work.
288  */
289 static int queue_ksmbd_work(struct ksmbd_conn *conn)
290 {
291 	struct ksmbd_work *work;
292 	int err;
293 
294 	work = ksmbd_alloc_work_struct();
295 	if (!work) {
296 		pr_err("allocation for work failed\n");
297 		return -ENOMEM;
298 	}
299 
300 	work->conn = conn;
301 	work->request_buf = conn->request_buf;
302 	conn->request_buf = NULL;
303 
304 	err = ksmbd_init_smb_server(work);
305 	if (err) {
306 		ksmbd_free_work_struct(work);
307 		return 0;
308 	}
309 
310 	ksmbd_conn_enqueue_request(work);
311 	atomic_inc(&conn->r_count);
312 	/* update activity on connection */
313 	conn->last_active = jiffies;
314 	INIT_WORK(&work->work, handle_ksmbd_work);
315 	ksmbd_queue_work(work);
316 	return 0;
317 }
318 
319 static int ksmbd_server_process_request(struct ksmbd_conn *conn)
320 {
321 	return queue_ksmbd_work(conn);
322 }
323 
324 static int ksmbd_server_terminate_conn(struct ksmbd_conn *conn)
325 {
326 	ksmbd_sessions_deregister(conn);
327 	destroy_lease_table(conn);
328 	return 0;
329 }
330 
331 static void ksmbd_server_tcp_callbacks_init(void)
332 {
333 	struct ksmbd_conn_ops ops;
334 
335 	ops.process_fn = ksmbd_server_process_request;
336 	ops.terminate_fn = ksmbd_server_terminate_conn;
337 
338 	ksmbd_conn_init_server_callbacks(&ops);
339 }
340 
341 static void server_conf_free(void)
342 {
343 	int i;
344 
345 	for (i = 0; i < ARRAY_SIZE(server_conf.conf); i++) {
346 		kfree(server_conf.conf[i]);
347 		server_conf.conf[i] = NULL;
348 	}
349 }
350 
351 static int server_conf_init(void)
352 {
353 	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
354 	server_conf.enforced_signing = 0;
355 	server_conf.min_protocol = ksmbd_min_protocol();
356 	server_conf.max_protocol = ksmbd_max_protocol();
357 	server_conf.auth_mechs = KSMBD_AUTH_NTLMSSP;
358 #ifdef CONFIG_SMB_SERVER_KERBEROS5
359 	server_conf.auth_mechs |= KSMBD_AUTH_KRB5 |
360 				KSMBD_AUTH_MSKRB5;
361 #endif
362 	return 0;
363 }
364 
365 static void server_ctrl_handle_init(struct server_ctrl_struct *ctrl)
366 {
367 	int ret;
368 
369 	ret = ksmbd_conn_transport_init();
370 	if (ret) {
371 		server_queue_ctrl_reset_work();
372 		return;
373 	}
374 
375 	WRITE_ONCE(server_conf.state, SERVER_STATE_RUNNING);
376 }
377 
378 static void server_ctrl_handle_reset(struct server_ctrl_struct *ctrl)
379 {
380 	ksmbd_ipc_soft_reset();
381 	ksmbd_conn_transport_destroy();
382 	server_conf_free();
383 	server_conf_init();
384 	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
385 }
386 
387 static void server_ctrl_handle_work(struct work_struct *work)
388 {
389 	struct server_ctrl_struct *ctrl;
390 
391 	ctrl = container_of(work, struct server_ctrl_struct, ctrl_work);
392 
393 	mutex_lock(&ctrl_lock);
394 	switch (ctrl->type) {
395 	case SERVER_CTRL_TYPE_INIT:
396 		server_ctrl_handle_init(ctrl);
397 		break;
398 	case SERVER_CTRL_TYPE_RESET:
399 		server_ctrl_handle_reset(ctrl);
400 		break;
401 	default:
402 		pr_err("Unknown server work type: %d\n", ctrl->type);
403 	}
404 	mutex_unlock(&ctrl_lock);
405 	kfree(ctrl);
406 	module_put(THIS_MODULE);
407 }
408 
409 static int __queue_ctrl_work(int type)
410 {
411 	struct server_ctrl_struct *ctrl;
412 
413 	ctrl = kmalloc(sizeof(struct server_ctrl_struct), GFP_KERNEL);
414 	if (!ctrl)
415 		return -ENOMEM;
416 
417 	__module_get(THIS_MODULE);
418 	ctrl->type = type;
419 	INIT_WORK(&ctrl->ctrl_work, server_ctrl_handle_work);
420 	queue_work(system_long_wq, &ctrl->ctrl_work);
421 	return 0;
422 }
423 
424 int server_queue_ctrl_init_work(void)
425 {
426 	return __queue_ctrl_work(SERVER_CTRL_TYPE_INIT);
427 }
428 
429 int server_queue_ctrl_reset_work(void)
430 {
431 	return __queue_ctrl_work(SERVER_CTRL_TYPE_RESET);
432 }
433 
434 static ssize_t stats_show(const struct class *class, const struct class_attribute *attr,
435 			  char *buf)
436 {
437 	/*
438 	 * Inc this each time you change stats output format,
439 	 * so user space will know what to do.
440 	 */
441 	static int stats_version = 2;
442 	static const char * const state[] = {
443 		"startup",
444 		"running",
445 		"reset",
446 		"shutdown"
447 	};
448 	return sysfs_emit(buf, "%d %s %d %lu\n", stats_version,
449 			  state[server_conf.state], server_conf.tcp_port,
450 			  server_conf.ipc_last_active / HZ);
451 }
452 
453 static ssize_t kill_server_store(const struct class *class,
454 				 const struct class_attribute *attr, const char *buf,
455 				 size_t len)
456 {
457 	if (!sysfs_streq(buf, "hard"))
458 		return len;
459 
460 	pr_info("kill command received\n");
461 	mutex_lock(&ctrl_lock);
462 	WRITE_ONCE(server_conf.state, SERVER_STATE_RESETTING);
463 	__module_get(THIS_MODULE);
464 	server_ctrl_handle_reset(NULL);
465 	module_put(THIS_MODULE);
466 	mutex_unlock(&ctrl_lock);
467 	return len;
468 }
469 
470 static const char * const debug_type_strings[] = {"smb", "auth", "vfs",
471 						  "oplock", "ipc", "conn",
472 						  "rdma"};
473 
474 static ssize_t debug_show(const struct class *class, const struct class_attribute *attr,
475 			  char *buf)
476 {
477 	ssize_t sz = 0;
478 	int i, pos = 0;
479 
480 	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
481 		if ((ksmbd_debug_types >> i) & 1) {
482 			pos = sysfs_emit_at(buf, sz, "[%s] ", debug_type_strings[i]);
483 		} else {
484 			pos = sysfs_emit_at(buf, sz, "%s ", debug_type_strings[i]);
485 		}
486 		sz += pos;
487 	}
488 	sz += sysfs_emit_at(buf, sz, "\n");
489 	return sz;
490 }
491 
492 static ssize_t debug_store(const struct class *class, const struct class_attribute *attr,
493 			   const char *buf, size_t len)
494 {
495 	int i;
496 
497 	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
498 		if (sysfs_streq(buf, "all")) {
499 			if (ksmbd_debug_types == KSMBD_DEBUG_ALL)
500 				ksmbd_debug_types = 0;
501 			else
502 				ksmbd_debug_types = KSMBD_DEBUG_ALL;
503 			break;
504 		}
505 
506 		if (sysfs_streq(buf, debug_type_strings[i])) {
507 			if (ksmbd_debug_types & (1 << i))
508 				ksmbd_debug_types &= ~(1 << i);
509 			else
510 				ksmbd_debug_types |= (1 << i);
511 			break;
512 		}
513 	}
514 
515 	return len;
516 }
517 
518 static CLASS_ATTR_RO(stats);
519 static CLASS_ATTR_WO(kill_server);
520 static CLASS_ATTR_RW(debug);
521 
522 static struct attribute *ksmbd_control_class_attrs[] = {
523 	&class_attr_stats.attr,
524 	&class_attr_kill_server.attr,
525 	&class_attr_debug.attr,
526 	NULL,
527 };
528 ATTRIBUTE_GROUPS(ksmbd_control_class);
529 
530 static struct class ksmbd_control_class = {
531 	.name		= "ksmbd-control",
532 	.class_groups	= ksmbd_control_class_groups,
533 };
534 
535 static int ksmbd_server_shutdown(void)
536 {
537 	WRITE_ONCE(server_conf.state, SERVER_STATE_SHUTTING_DOWN);
538 
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_server_tcp_callbacks_init();
563 
564 	ret = server_conf_init();
565 	if (ret)
566 		goto err_unregister;
567 
568 	ret = ksmbd_work_pool_init();
569 	if (ret)
570 		goto err_unregister;
571 
572 	ret = ksmbd_init_file_cache();
573 	if (ret)
574 		goto err_destroy_work_pools;
575 
576 	ret = ksmbd_ipc_init();
577 	if (ret)
578 		goto err_exit_file_cache;
579 
580 	ret = ksmbd_init_global_file_table();
581 	if (ret)
582 		goto err_ipc_release;
583 
584 	ret = ksmbd_inode_hash_init();
585 	if (ret)
586 		goto err_destroy_file_table;
587 
588 	ret = ksmbd_crypto_create();
589 	if (ret)
590 		goto err_release_inode_hash;
591 
592 	ret = ksmbd_workqueue_init();
593 	if (ret)
594 		goto err_crypto_destroy;
595 
596 	return 0;
597 
598 err_crypto_destroy:
599 	ksmbd_crypto_destroy();
600 err_release_inode_hash:
601 	ksmbd_release_inode_hash();
602 err_destroy_file_table:
603 	ksmbd_free_global_file_table();
604 err_ipc_release:
605 	ksmbd_ipc_release();
606 err_exit_file_cache:
607 	ksmbd_exit_file_cache();
608 err_destroy_work_pools:
609 	ksmbd_work_pool_destroy();
610 err_unregister:
611 	class_unregister(&ksmbd_control_class);
612 
613 	return ret;
614 }
615 
616 /**
617  * ksmbd_server_exit() - shutdown forker thread and free memory at module exit
618  */
619 static void __exit ksmbd_server_exit(void)
620 {
621 	ksmbd_server_shutdown();
622 	rcu_barrier();
623 	ksmbd_release_inode_hash();
624 }
625 
626 MODULE_AUTHOR("Namjae Jeon <linkinjeon@kernel.org>");
627 MODULE_VERSION(KSMBD_VERSION);
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