xref: /openbmc/linux/fs/smb/server/server.c (revision 657c45b3)
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 		return SERVER_HANDLER_ABORT;
120 
121 	command = conn->ops->get_cmd_val(work);
122 	*cmd = command;
123 
124 andx_again:
125 	if (command >= conn->max_cmds) {
126 		conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER);
127 		return SERVER_HANDLER_CONTINUE;
128 	}
129 
130 	cmds = &conn->cmds[command];
131 	if (!cmds->proc) {
132 		ksmbd_debug(SMB, "*** not implemented yet cmd = %x\n", command);
133 		conn->ops->set_rsp_status(work, STATUS_NOT_IMPLEMENTED);
134 		return SERVER_HANDLER_CONTINUE;
135 	}
136 
137 	if (work->sess && conn->ops->is_sign_req(work, command)) {
138 		ret = conn->ops->check_sign_req(work);
139 		if (!ret) {
140 			conn->ops->set_rsp_status(work, STATUS_ACCESS_DENIED);
141 			return SERVER_HANDLER_CONTINUE;
142 		}
143 	}
144 
145 	ret = cmds->proc(work);
146 
147 	if (ret < 0)
148 		ksmbd_debug(CONN, "Failed to process %u [%d]\n", command, ret);
149 	/* AndX commands - chained request can return positive values */
150 	else if (ret > 0) {
151 		command = ret;
152 		*cmd = command;
153 		goto andx_again;
154 	}
155 
156 	if (work->send_no_response)
157 		return SERVER_HANDLER_ABORT;
158 	return SERVER_HANDLER_CONTINUE;
159 }
160 
161 static void __handle_ksmbd_work(struct ksmbd_work *work,
162 				struct ksmbd_conn *conn)
163 {
164 	u16 command = 0;
165 	int rc;
166 
167 	if (conn->ops->allocate_rsp_buf(work))
168 		return;
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 			conn->ops->set_rsp_status(work, STATUS_DATA_ERROR);
175 			goto send;
176 		}
177 
178 		work->encrypted = true;
179 	}
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 		if (work->sess &&
233 		    (work->sess->sign || smb3_11_final_sess_setup_resp(work) ||
234 		     conn->ops->is_sign_req(work, command)))
235 			conn->ops->set_sign_rsp(work);
236 	} while (is_chained_smb2_message(work));
237 
238 	if (work->send_no_response)
239 		return;
240 
241 send:
242 	smb3_preauth_hash_rsp(work);
243 	if (work->sess && work->sess->enc && work->encrypted &&
244 	    conn->ops->encrypt_resp) {
245 		rc = conn->ops->encrypt_resp(work);
246 		if (rc < 0)
247 			conn->ops->set_rsp_status(work, STATUS_DATA_ERROR);
248 	}
249 
250 	ksmbd_conn_write(work);
251 }
252 
253 /**
254  * handle_ksmbd_work() - process pending smb work requests
255  * @wk:	smb work containing request command buffer
256  *
257  * called by kworker threads to processing remaining smb work requests
258  */
259 static void handle_ksmbd_work(struct work_struct *wk)
260 {
261 	struct ksmbd_work *work = container_of(wk, struct ksmbd_work, work);
262 	struct ksmbd_conn *conn = work->conn;
263 
264 	atomic64_inc(&conn->stats.request_served);
265 
266 	__handle_ksmbd_work(work, conn);
267 
268 	ksmbd_conn_try_dequeue_request(work);
269 	ksmbd_free_work_struct(work);
270 	/*
271 	 * Checking waitqueue to dropping pending requests on
272 	 * disconnection. waitqueue_active is safe because it
273 	 * uses atomic operation for condition.
274 	 */
275 	if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q))
276 		wake_up(&conn->r_count_q);
277 }
278 
279 /**
280  * queue_ksmbd_work() - queue a smb request to worker thread queue
281  *		for proccessing 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 
290 	work = ksmbd_alloc_work_struct();
291 	if (!work) {
292 		pr_err("allocation for work failed\n");
293 		return -ENOMEM;
294 	}
295 
296 	work->conn = conn;
297 	work->request_buf = conn->request_buf;
298 	conn->request_buf = NULL;
299 
300 	ksmbd_init_smb_server(work);
301 
302 	ksmbd_conn_enqueue_request(work);
303 	atomic_inc(&conn->r_count);
304 	/* update activity on connection */
305 	conn->last_active = jiffies;
306 	INIT_WORK(&work->work, handle_ksmbd_work);
307 	ksmbd_queue_work(work);
308 	return 0;
309 }
310 
311 static int ksmbd_server_process_request(struct ksmbd_conn *conn)
312 {
313 	return queue_ksmbd_work(conn);
314 }
315 
316 static int ksmbd_server_terminate_conn(struct ksmbd_conn *conn)
317 {
318 	ksmbd_sessions_deregister(conn);
319 	destroy_lease_table(conn);
320 	return 0;
321 }
322 
323 static void ksmbd_server_tcp_callbacks_init(void)
324 {
325 	struct ksmbd_conn_ops ops;
326 
327 	ops.process_fn = ksmbd_server_process_request;
328 	ops.terminate_fn = ksmbd_server_terminate_conn;
329 
330 	ksmbd_conn_init_server_callbacks(&ops);
331 }
332 
333 static void server_conf_free(void)
334 {
335 	int i;
336 
337 	for (i = 0; i < ARRAY_SIZE(server_conf.conf); i++) {
338 		kfree(server_conf.conf[i]);
339 		server_conf.conf[i] = NULL;
340 	}
341 }
342 
343 static int server_conf_init(void)
344 {
345 	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
346 	server_conf.enforced_signing = 0;
347 	server_conf.min_protocol = ksmbd_min_protocol();
348 	server_conf.max_protocol = ksmbd_max_protocol();
349 	server_conf.auth_mechs = KSMBD_AUTH_NTLMSSP;
350 #ifdef CONFIG_SMB_SERVER_KERBEROS5
351 	server_conf.auth_mechs |= KSMBD_AUTH_KRB5 |
352 				KSMBD_AUTH_MSKRB5;
353 #endif
354 	return 0;
355 }
356 
357 static void server_ctrl_handle_init(struct server_ctrl_struct *ctrl)
358 {
359 	int ret;
360 
361 	ret = ksmbd_conn_transport_init();
362 	if (ret) {
363 		server_queue_ctrl_reset_work();
364 		return;
365 	}
366 
367 	WRITE_ONCE(server_conf.state, SERVER_STATE_RUNNING);
368 }
369 
370 static void server_ctrl_handle_reset(struct server_ctrl_struct *ctrl)
371 {
372 	ksmbd_ipc_soft_reset();
373 	ksmbd_conn_transport_destroy();
374 	server_conf_free();
375 	server_conf_init();
376 	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
377 }
378 
379 static void server_ctrl_handle_work(struct work_struct *work)
380 {
381 	struct server_ctrl_struct *ctrl;
382 
383 	ctrl = container_of(work, struct server_ctrl_struct, ctrl_work);
384 
385 	mutex_lock(&ctrl_lock);
386 	switch (ctrl->type) {
387 	case SERVER_CTRL_TYPE_INIT:
388 		server_ctrl_handle_init(ctrl);
389 		break;
390 	case SERVER_CTRL_TYPE_RESET:
391 		server_ctrl_handle_reset(ctrl);
392 		break;
393 	default:
394 		pr_err("Unknown server work type: %d\n", ctrl->type);
395 	}
396 	mutex_unlock(&ctrl_lock);
397 	kfree(ctrl);
398 	module_put(THIS_MODULE);
399 }
400 
401 static int __queue_ctrl_work(int type)
402 {
403 	struct server_ctrl_struct *ctrl;
404 
405 	ctrl = kmalloc(sizeof(struct server_ctrl_struct), GFP_KERNEL);
406 	if (!ctrl)
407 		return -ENOMEM;
408 
409 	__module_get(THIS_MODULE);
410 	ctrl->type = type;
411 	INIT_WORK(&ctrl->ctrl_work, server_ctrl_handle_work);
412 	queue_work(system_long_wq, &ctrl->ctrl_work);
413 	return 0;
414 }
415 
416 int server_queue_ctrl_init_work(void)
417 {
418 	return __queue_ctrl_work(SERVER_CTRL_TYPE_INIT);
419 }
420 
421 int server_queue_ctrl_reset_work(void)
422 {
423 	return __queue_ctrl_work(SERVER_CTRL_TYPE_RESET);
424 }
425 
426 static ssize_t stats_show(const struct class *class, const struct class_attribute *attr,
427 			  char *buf)
428 {
429 	/*
430 	 * Inc this each time you change stats output format,
431 	 * so user space will know what to do.
432 	 */
433 	static int stats_version = 2;
434 	static const char * const state[] = {
435 		"startup",
436 		"running",
437 		"reset",
438 		"shutdown"
439 	};
440 	return sysfs_emit(buf, "%d %s %d %lu\n", stats_version,
441 			  state[server_conf.state], server_conf.tcp_port,
442 			  server_conf.ipc_last_active / HZ);
443 }
444 
445 static ssize_t kill_server_store(const struct class *class,
446 				 const struct class_attribute *attr, const char *buf,
447 				 size_t len)
448 {
449 	if (!sysfs_streq(buf, "hard"))
450 		return len;
451 
452 	pr_info("kill command received\n");
453 	mutex_lock(&ctrl_lock);
454 	WRITE_ONCE(server_conf.state, SERVER_STATE_RESETTING);
455 	__module_get(THIS_MODULE);
456 	server_ctrl_handle_reset(NULL);
457 	module_put(THIS_MODULE);
458 	mutex_unlock(&ctrl_lock);
459 	return len;
460 }
461 
462 static const char * const debug_type_strings[] = {"smb", "auth", "vfs",
463 						  "oplock", "ipc", "conn",
464 						  "rdma"};
465 
466 static ssize_t debug_show(const struct class *class, const struct class_attribute *attr,
467 			  char *buf)
468 {
469 	ssize_t sz = 0;
470 	int i, pos = 0;
471 
472 	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
473 		if ((ksmbd_debug_types >> i) & 1) {
474 			pos = sysfs_emit_at(buf, sz, "[%s] ", debug_type_strings[i]);
475 		} else {
476 			pos = sysfs_emit_at(buf, sz, "%s ", debug_type_strings[i]);
477 		}
478 		sz += pos;
479 	}
480 	sz += sysfs_emit_at(buf, sz, "\n");
481 	return sz;
482 }
483 
484 static ssize_t debug_store(const struct class *class, const struct class_attribute *attr,
485 			   const char *buf, size_t len)
486 {
487 	int i;
488 
489 	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
490 		if (sysfs_streq(buf, "all")) {
491 			if (ksmbd_debug_types == KSMBD_DEBUG_ALL)
492 				ksmbd_debug_types = 0;
493 			else
494 				ksmbd_debug_types = KSMBD_DEBUG_ALL;
495 			break;
496 		}
497 
498 		if (sysfs_streq(buf, debug_type_strings[i])) {
499 			if (ksmbd_debug_types & (1 << i))
500 				ksmbd_debug_types &= ~(1 << i);
501 			else
502 				ksmbd_debug_types |= (1 << i);
503 			break;
504 		}
505 	}
506 
507 	return len;
508 }
509 
510 static CLASS_ATTR_RO(stats);
511 static CLASS_ATTR_WO(kill_server);
512 static CLASS_ATTR_RW(debug);
513 
514 static struct attribute *ksmbd_control_class_attrs[] = {
515 	&class_attr_stats.attr,
516 	&class_attr_kill_server.attr,
517 	&class_attr_debug.attr,
518 	NULL,
519 };
520 ATTRIBUTE_GROUPS(ksmbd_control_class);
521 
522 static struct class ksmbd_control_class = {
523 	.name		= "ksmbd-control",
524 	.class_groups	= ksmbd_control_class_groups,
525 };
526 
527 static int ksmbd_server_shutdown(void)
528 {
529 	WRITE_ONCE(server_conf.state, SERVER_STATE_SHUTTING_DOWN);
530 
531 	class_unregister(&ksmbd_control_class);
532 	ksmbd_workqueue_destroy();
533 	ksmbd_ipc_release();
534 	ksmbd_conn_transport_destroy();
535 	ksmbd_crypto_destroy();
536 	ksmbd_free_global_file_table();
537 	destroy_lease_table(NULL);
538 	ksmbd_work_pool_destroy();
539 	ksmbd_exit_file_cache();
540 	server_conf_free();
541 	return 0;
542 }
543 
544 static int __init ksmbd_server_init(void)
545 {
546 	int ret;
547 
548 	ret = class_register(&ksmbd_control_class);
549 	if (ret) {
550 		pr_err("Unable to register ksmbd-control class\n");
551 		return ret;
552 	}
553 
554 	ksmbd_server_tcp_callbacks_init();
555 
556 	ret = server_conf_init();
557 	if (ret)
558 		goto err_unregister;
559 
560 	ret = ksmbd_work_pool_init();
561 	if (ret)
562 		goto err_unregister;
563 
564 	ret = ksmbd_init_file_cache();
565 	if (ret)
566 		goto err_destroy_work_pools;
567 
568 	ret = ksmbd_ipc_init();
569 	if (ret)
570 		goto err_exit_file_cache;
571 
572 	ret = ksmbd_init_global_file_table();
573 	if (ret)
574 		goto err_ipc_release;
575 
576 	ret = ksmbd_inode_hash_init();
577 	if (ret)
578 		goto err_destroy_file_table;
579 
580 	ret = ksmbd_crypto_create();
581 	if (ret)
582 		goto err_release_inode_hash;
583 
584 	ret = ksmbd_workqueue_init();
585 	if (ret)
586 		goto err_crypto_destroy;
587 
588 	pr_warn_once("The ksmbd server is experimental\n");
589 
590 	return 0;
591 
592 err_crypto_destroy:
593 	ksmbd_crypto_destroy();
594 err_release_inode_hash:
595 	ksmbd_release_inode_hash();
596 err_destroy_file_table:
597 	ksmbd_free_global_file_table();
598 err_ipc_release:
599 	ksmbd_ipc_release();
600 err_exit_file_cache:
601 	ksmbd_exit_file_cache();
602 err_destroy_work_pools:
603 	ksmbd_work_pool_destroy();
604 err_unregister:
605 	class_unregister(&ksmbd_control_class);
606 
607 	return ret;
608 }
609 
610 /**
611  * ksmbd_server_exit() - shutdown forker thread and free memory at module exit
612  */
613 static void __exit ksmbd_server_exit(void)
614 {
615 	ksmbd_server_shutdown();
616 	rcu_barrier();
617 	ksmbd_release_inode_hash();
618 }
619 
620 MODULE_AUTHOR("Namjae Jeon <linkinjeon@kernel.org>");
621 MODULE_VERSION(KSMBD_VERSION);
622 MODULE_DESCRIPTION("Linux kernel CIFS/SMB SERVER");
623 MODULE_LICENSE("GPL");
624 MODULE_SOFTDEP("pre: ecb");
625 MODULE_SOFTDEP("pre: hmac");
626 MODULE_SOFTDEP("pre: md5");
627 MODULE_SOFTDEP("pre: nls");
628 MODULE_SOFTDEP("pre: aes");
629 MODULE_SOFTDEP("pre: cmac");
630 MODULE_SOFTDEP("pre: sha256");
631 MODULE_SOFTDEP("pre: sha512");
632 MODULE_SOFTDEP("pre: aead2");
633 MODULE_SOFTDEP("pre: ccm");
634 MODULE_SOFTDEP("pre: gcm");
635 MODULE_SOFTDEP("pre: crc32");
636 module_init(ksmbd_server_init)
637 module_exit(ksmbd_server_exit)
638