xref: /openbmc/linux/fs/smb/server/server.c (revision 196eec40)
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 	if (conn->ops->check_user_session) {
189 		rc = conn->ops->check_user_session(work);
190 		if (rc < 0) {
191 			command = conn->ops->get_cmd_val(work);
192 			conn->ops->set_rsp_status(work,
193 					STATUS_USER_SESSION_DELETED);
194 			goto send;
195 		} else if (rc > 0) {
196 			rc = conn->ops->get_ksmbd_tcon(work);
197 			if (rc < 0) {
198 				conn->ops->set_rsp_status(work,
199 					STATUS_NETWORK_NAME_DELETED);
200 				goto send;
201 			}
202 		}
203 	}
204 
205 	do {
206 		rc = __process_request(work, conn, &command);
207 		if (rc == SERVER_HANDLER_ABORT)
208 			break;
209 
210 		/*
211 		 * Call smb2_set_rsp_credits() function to set number of credits
212 		 * granted in hdr of smb2 response.
213 		 */
214 		if (conn->ops->set_rsp_credits) {
215 			spin_lock(&conn->credits_lock);
216 			rc = conn->ops->set_rsp_credits(work);
217 			spin_unlock(&conn->credits_lock);
218 			if (rc < 0) {
219 				conn->ops->set_rsp_status(work,
220 					STATUS_INVALID_PARAMETER);
221 				goto send;
222 			}
223 		}
224 
225 		if (work->sess &&
226 		    (work->sess->sign || smb3_11_final_sess_setup_resp(work) ||
227 		     conn->ops->is_sign_req(work, command)))
228 			conn->ops->set_sign_rsp(work);
229 	} while (is_chained_smb2_message(work));
230 
231 	if (work->send_no_response)
232 		return;
233 
234 send:
235 	smb3_preauth_hash_rsp(work);
236 	if (work->sess && work->sess->enc && work->encrypted &&
237 	    conn->ops->encrypt_resp) {
238 		rc = conn->ops->encrypt_resp(work);
239 		if (rc < 0)
240 			conn->ops->set_rsp_status(work, STATUS_DATA_ERROR);
241 	}
242 
243 	ksmbd_conn_write(work);
244 }
245 
246 /**
247  * handle_ksmbd_work() - process pending smb work requests
248  * @wk:	smb work containing request command buffer
249  *
250  * called by kworker threads to processing remaining smb work requests
251  */
252 static void handle_ksmbd_work(struct work_struct *wk)
253 {
254 	struct ksmbd_work *work = container_of(wk, struct ksmbd_work, work);
255 	struct ksmbd_conn *conn = work->conn;
256 
257 	atomic64_inc(&conn->stats.request_served);
258 
259 	__handle_ksmbd_work(work, conn);
260 
261 	ksmbd_conn_try_dequeue_request(work);
262 	ksmbd_free_work_struct(work);
263 	/*
264 	 * Checking waitqueue to dropping pending requests on
265 	 * disconnection. waitqueue_active is safe because it
266 	 * uses atomic operation for condition.
267 	 */
268 	if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q))
269 		wake_up(&conn->r_count_q);
270 }
271 
272 /**
273  * queue_ksmbd_work() - queue a smb request to worker thread queue
274  *		for proccessing smb command and sending response
275  * @conn:	connection instance
276  *
277  * read remaining data from socket create and submit work.
278  */
279 static int queue_ksmbd_work(struct ksmbd_conn *conn)
280 {
281 	struct ksmbd_work *work;
282 
283 	work = ksmbd_alloc_work_struct();
284 	if (!work) {
285 		pr_err("allocation for work failed\n");
286 		return -ENOMEM;
287 	}
288 
289 	work->conn = conn;
290 	work->request_buf = conn->request_buf;
291 	conn->request_buf = NULL;
292 
293 	ksmbd_init_smb_server(work);
294 
295 	ksmbd_conn_enqueue_request(work);
296 	atomic_inc(&conn->r_count);
297 	/* update activity on connection */
298 	conn->last_active = jiffies;
299 	INIT_WORK(&work->work, handle_ksmbd_work);
300 	ksmbd_queue_work(work);
301 	return 0;
302 }
303 
304 static int ksmbd_server_process_request(struct ksmbd_conn *conn)
305 {
306 	return queue_ksmbd_work(conn);
307 }
308 
309 static int ksmbd_server_terminate_conn(struct ksmbd_conn *conn)
310 {
311 	ksmbd_sessions_deregister(conn);
312 	destroy_lease_table(conn);
313 	return 0;
314 }
315 
316 static void ksmbd_server_tcp_callbacks_init(void)
317 {
318 	struct ksmbd_conn_ops ops;
319 
320 	ops.process_fn = ksmbd_server_process_request;
321 	ops.terminate_fn = ksmbd_server_terminate_conn;
322 
323 	ksmbd_conn_init_server_callbacks(&ops);
324 }
325 
326 static void server_conf_free(void)
327 {
328 	int i;
329 
330 	for (i = 0; i < ARRAY_SIZE(server_conf.conf); i++) {
331 		kfree(server_conf.conf[i]);
332 		server_conf.conf[i] = NULL;
333 	}
334 }
335 
336 static int server_conf_init(void)
337 {
338 	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
339 	server_conf.enforced_signing = 0;
340 	server_conf.min_protocol = ksmbd_min_protocol();
341 	server_conf.max_protocol = ksmbd_max_protocol();
342 	server_conf.auth_mechs = KSMBD_AUTH_NTLMSSP;
343 #ifdef CONFIG_SMB_SERVER_KERBEROS5
344 	server_conf.auth_mechs |= KSMBD_AUTH_KRB5 |
345 				KSMBD_AUTH_MSKRB5;
346 #endif
347 	return 0;
348 }
349 
350 static void server_ctrl_handle_init(struct server_ctrl_struct *ctrl)
351 {
352 	int ret;
353 
354 	ret = ksmbd_conn_transport_init();
355 	if (ret) {
356 		server_queue_ctrl_reset_work();
357 		return;
358 	}
359 
360 	WRITE_ONCE(server_conf.state, SERVER_STATE_RUNNING);
361 }
362 
363 static void server_ctrl_handle_reset(struct server_ctrl_struct *ctrl)
364 {
365 	ksmbd_ipc_soft_reset();
366 	ksmbd_conn_transport_destroy();
367 	server_conf_free();
368 	server_conf_init();
369 	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
370 }
371 
372 static void server_ctrl_handle_work(struct work_struct *work)
373 {
374 	struct server_ctrl_struct *ctrl;
375 
376 	ctrl = container_of(work, struct server_ctrl_struct, ctrl_work);
377 
378 	mutex_lock(&ctrl_lock);
379 	switch (ctrl->type) {
380 	case SERVER_CTRL_TYPE_INIT:
381 		server_ctrl_handle_init(ctrl);
382 		break;
383 	case SERVER_CTRL_TYPE_RESET:
384 		server_ctrl_handle_reset(ctrl);
385 		break;
386 	default:
387 		pr_err("Unknown server work type: %d\n", ctrl->type);
388 	}
389 	mutex_unlock(&ctrl_lock);
390 	kfree(ctrl);
391 	module_put(THIS_MODULE);
392 }
393 
394 static int __queue_ctrl_work(int type)
395 {
396 	struct server_ctrl_struct *ctrl;
397 
398 	ctrl = kmalloc(sizeof(struct server_ctrl_struct), GFP_KERNEL);
399 	if (!ctrl)
400 		return -ENOMEM;
401 
402 	__module_get(THIS_MODULE);
403 	ctrl->type = type;
404 	INIT_WORK(&ctrl->ctrl_work, server_ctrl_handle_work);
405 	queue_work(system_long_wq, &ctrl->ctrl_work);
406 	return 0;
407 }
408 
409 int server_queue_ctrl_init_work(void)
410 {
411 	return __queue_ctrl_work(SERVER_CTRL_TYPE_INIT);
412 }
413 
414 int server_queue_ctrl_reset_work(void)
415 {
416 	return __queue_ctrl_work(SERVER_CTRL_TYPE_RESET);
417 }
418 
419 static ssize_t stats_show(const struct class *class, const struct class_attribute *attr,
420 			  char *buf)
421 {
422 	/*
423 	 * Inc this each time you change stats output format,
424 	 * so user space will know what to do.
425 	 */
426 	static int stats_version = 2;
427 	static const char * const state[] = {
428 		"startup",
429 		"running",
430 		"reset",
431 		"shutdown"
432 	};
433 	return sysfs_emit(buf, "%d %s %d %lu\n", stats_version,
434 			  state[server_conf.state], server_conf.tcp_port,
435 			  server_conf.ipc_last_active / HZ);
436 }
437 
438 static ssize_t kill_server_store(const struct class *class,
439 				 const struct class_attribute *attr, const char *buf,
440 				 size_t len)
441 {
442 	if (!sysfs_streq(buf, "hard"))
443 		return len;
444 
445 	pr_info("kill command received\n");
446 	mutex_lock(&ctrl_lock);
447 	WRITE_ONCE(server_conf.state, SERVER_STATE_RESETTING);
448 	__module_get(THIS_MODULE);
449 	server_ctrl_handle_reset(NULL);
450 	module_put(THIS_MODULE);
451 	mutex_unlock(&ctrl_lock);
452 	return len;
453 }
454 
455 static const char * const debug_type_strings[] = {"smb", "auth", "vfs",
456 						  "oplock", "ipc", "conn",
457 						  "rdma"};
458 
459 static ssize_t debug_show(const struct class *class, const struct class_attribute *attr,
460 			  char *buf)
461 {
462 	ssize_t sz = 0;
463 	int i, pos = 0;
464 
465 	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
466 		if ((ksmbd_debug_types >> i) & 1) {
467 			pos = sysfs_emit_at(buf, sz, "[%s] ", debug_type_strings[i]);
468 		} else {
469 			pos = sysfs_emit_at(buf, sz, "%s ", debug_type_strings[i]);
470 		}
471 		sz += pos;
472 	}
473 	sz += sysfs_emit_at(buf, sz, "\n");
474 	return sz;
475 }
476 
477 static ssize_t debug_store(const struct class *class, const struct class_attribute *attr,
478 			   const char *buf, size_t len)
479 {
480 	int i;
481 
482 	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
483 		if (sysfs_streq(buf, "all")) {
484 			if (ksmbd_debug_types == KSMBD_DEBUG_ALL)
485 				ksmbd_debug_types = 0;
486 			else
487 				ksmbd_debug_types = KSMBD_DEBUG_ALL;
488 			break;
489 		}
490 
491 		if (sysfs_streq(buf, debug_type_strings[i])) {
492 			if (ksmbd_debug_types & (1 << i))
493 				ksmbd_debug_types &= ~(1 << i);
494 			else
495 				ksmbd_debug_types |= (1 << i);
496 			break;
497 		}
498 	}
499 
500 	return len;
501 }
502 
503 static CLASS_ATTR_RO(stats);
504 static CLASS_ATTR_WO(kill_server);
505 static CLASS_ATTR_RW(debug);
506 
507 static struct attribute *ksmbd_control_class_attrs[] = {
508 	&class_attr_stats.attr,
509 	&class_attr_kill_server.attr,
510 	&class_attr_debug.attr,
511 	NULL,
512 };
513 ATTRIBUTE_GROUPS(ksmbd_control_class);
514 
515 static struct class ksmbd_control_class = {
516 	.name		= "ksmbd-control",
517 	.class_groups	= ksmbd_control_class_groups,
518 };
519 
520 static int ksmbd_server_shutdown(void)
521 {
522 	WRITE_ONCE(server_conf.state, SERVER_STATE_SHUTTING_DOWN);
523 
524 	class_unregister(&ksmbd_control_class);
525 	ksmbd_workqueue_destroy();
526 	ksmbd_ipc_release();
527 	ksmbd_conn_transport_destroy();
528 	ksmbd_crypto_destroy();
529 	ksmbd_free_global_file_table();
530 	destroy_lease_table(NULL);
531 	ksmbd_work_pool_destroy();
532 	ksmbd_exit_file_cache();
533 	server_conf_free();
534 	return 0;
535 }
536 
537 static int __init ksmbd_server_init(void)
538 {
539 	int ret;
540 
541 	ret = class_register(&ksmbd_control_class);
542 	if (ret) {
543 		pr_err("Unable to register ksmbd-control class\n");
544 		return ret;
545 	}
546 
547 	ksmbd_server_tcp_callbacks_init();
548 
549 	ret = server_conf_init();
550 	if (ret)
551 		goto err_unregister;
552 
553 	ret = ksmbd_work_pool_init();
554 	if (ret)
555 		goto err_unregister;
556 
557 	ret = ksmbd_init_file_cache();
558 	if (ret)
559 		goto err_destroy_work_pools;
560 
561 	ret = ksmbd_ipc_init();
562 	if (ret)
563 		goto err_exit_file_cache;
564 
565 	ret = ksmbd_init_global_file_table();
566 	if (ret)
567 		goto err_ipc_release;
568 
569 	ret = ksmbd_inode_hash_init();
570 	if (ret)
571 		goto err_destroy_file_table;
572 
573 	ret = ksmbd_crypto_create();
574 	if (ret)
575 		goto err_release_inode_hash;
576 
577 	ret = ksmbd_workqueue_init();
578 	if (ret)
579 		goto err_crypto_destroy;
580 
581 	pr_warn_once("The ksmbd server is experimental\n");
582 
583 	return 0;
584 
585 err_crypto_destroy:
586 	ksmbd_crypto_destroy();
587 err_release_inode_hash:
588 	ksmbd_release_inode_hash();
589 err_destroy_file_table:
590 	ksmbd_free_global_file_table();
591 err_ipc_release:
592 	ksmbd_ipc_release();
593 err_exit_file_cache:
594 	ksmbd_exit_file_cache();
595 err_destroy_work_pools:
596 	ksmbd_work_pool_destroy();
597 err_unregister:
598 	class_unregister(&ksmbd_control_class);
599 
600 	return ret;
601 }
602 
603 /**
604  * ksmbd_server_exit() - shutdown forker thread and free memory at module exit
605  */
606 static void __exit ksmbd_server_exit(void)
607 {
608 	ksmbd_server_shutdown();
609 	rcu_barrier();
610 	ksmbd_release_inode_hash();
611 }
612 
613 MODULE_AUTHOR("Namjae Jeon <linkinjeon@kernel.org>");
614 MODULE_VERSION(KSMBD_VERSION);
615 MODULE_DESCRIPTION("Linux kernel CIFS/SMB SERVER");
616 MODULE_LICENSE("GPL");
617 MODULE_SOFTDEP("pre: ecb");
618 MODULE_SOFTDEP("pre: hmac");
619 MODULE_SOFTDEP("pre: md5");
620 MODULE_SOFTDEP("pre: nls");
621 MODULE_SOFTDEP("pre: aes");
622 MODULE_SOFTDEP("pre: cmac");
623 MODULE_SOFTDEP("pre: sha256");
624 MODULE_SOFTDEP("pre: sha512");
625 MODULE_SOFTDEP("pre: aead2");
626 MODULE_SOFTDEP("pre: ccm");
627 MODULE_SOFTDEP("pre: gcm");
628 MODULE_SOFTDEP("pre: crc32");
629 module_init(ksmbd_server_init)
630 module_exit(ksmbd_server_exit)
631