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  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
 25int ksmbd_debug_types;
 26
 27struct ksmbd_server_config server_conf;
 28
 29enum SERVER_CTRL_TYPE {
 30	SERVER_CTRL_TYPE_INIT,
 31	SERVER_CTRL_TYPE_RESET,
 32};
 33
 34struct server_ctrl_struct {
 35	int			type;
 36	struct work_struct	ctrl_work;
 37};
 38
 39static DEFINE_MUTEX(ctrl_lock);
 40
 41static 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
 56int ksmbd_set_netbios_name(char *v)
 57{
 58	return ___server_conf_set(SERVER_CONF_NETBIOS_NAME, v);
 59}
 60
 61int ksmbd_set_server_string(char *v)
 62{
 63	return ___server_conf_set(SERVER_CONF_SERVER_STRING, v);
 64}
 65
 66int ksmbd_set_work_group(char *v)
 67{
 68	return ___server_conf_set(SERVER_CONF_WORK_GROUP, v);
 69}
 70
 71char *ksmbd_netbios_name(void)
 72{
 73	return server_conf.conf[SERVER_CONF_NETBIOS_NAME];
 74}
 75
 76char *ksmbd_server_string(void)
 77{
 78	return server_conf.conf[SERVER_CONF_SERVER_STRING];
 79}
 80
 81char *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 */
 92static 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
108static 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
126andx_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
163static 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
240send:
241	if (work->tcon)
242		ksmbd_tree_connect_put(work->tcon);
243	smb3_preauth_hash_rsp(work);
244	if (work->sess && work->sess->enc && work->encrypted &&
245	    conn->ops->encrypt_resp) {
246		rc = conn->ops->encrypt_resp(work);
247		if (rc < 0)
248			conn->ops->set_rsp_status(work, STATUS_DATA_ERROR);
249	}
250
251	ksmbd_conn_write(work);
252}
253
254/**
255 * handle_ksmbd_work() - process pending smb work requests
256 * @wk:	smb work containing request command buffer
257 *
258 * called by kworker threads to processing remaining smb work requests
259 */
260static void handle_ksmbd_work(struct work_struct *wk)
261{
262	struct ksmbd_work *work = container_of(wk, struct ksmbd_work, work);
263	struct ksmbd_conn *conn = work->conn;
264
265	atomic64_inc(&conn->stats.request_served);
266
267	__handle_ksmbd_work(work, conn);
268
269	ksmbd_conn_try_dequeue_request(work);
270	ksmbd_free_work_struct(work);
271	/*
272	 * Checking waitqueue to dropping pending requests on
273	 * disconnection. waitqueue_active is safe because it
274	 * uses atomic operation for condition.
275	 */
276	if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q))
277		wake_up(&conn->r_count_q);
278}
279
280/**
281 * queue_ksmbd_work() - queue a smb request to worker thread queue
282 *		for proccessing smb command and sending response
283 * @conn:	connection instance
284 *
285 * read remaining data from socket create and submit work.
286 */
287static int queue_ksmbd_work(struct ksmbd_conn *conn)
288{
289	struct ksmbd_work *work;
290	int err;
291
292	work = ksmbd_alloc_work_struct();
293	if (!work) {
294		pr_err("allocation for work failed\n");
295		return -ENOMEM;
296	}
297
298	work->conn = conn;
299	work->request_buf = conn->request_buf;
300	conn->request_buf = NULL;
301
302	err = ksmbd_init_smb_server(work);
303	if (err) {
304		ksmbd_free_work_struct(work);
305		return 0;
306	}
307
308	ksmbd_conn_enqueue_request(work);
309	atomic_inc(&conn->r_count);
310	/* update activity on connection */
311	conn->last_active = jiffies;
312	INIT_WORK(&work->work, handle_ksmbd_work);
313	ksmbd_queue_work(work);
314	return 0;
315}
316
317static int ksmbd_server_process_request(struct ksmbd_conn *conn)
318{
319	return queue_ksmbd_work(conn);
320}
321
322static int ksmbd_server_terminate_conn(struct ksmbd_conn *conn)
323{
324	ksmbd_sessions_deregister(conn);
325	destroy_lease_table(conn);
326	return 0;
327}
328
329static void ksmbd_server_tcp_callbacks_init(void)
330{
331	struct ksmbd_conn_ops ops;
332
333	ops.process_fn = ksmbd_server_process_request;
334	ops.terminate_fn = ksmbd_server_terminate_conn;
335
336	ksmbd_conn_init_server_callbacks(&ops);
337}
338
339static void server_conf_free(void)
340{
341	int i;
342
343	for (i = 0; i < ARRAY_SIZE(server_conf.conf); i++) {
344		kfree(server_conf.conf[i]);
345		server_conf.conf[i] = NULL;
346	}
347}
348
349static int server_conf_init(void)
350{
351	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
352	server_conf.enforced_signing = 0;
353	server_conf.min_protocol = ksmbd_min_protocol();
354	server_conf.max_protocol = ksmbd_max_protocol();
355	server_conf.auth_mechs = KSMBD_AUTH_NTLMSSP;
356#ifdef CONFIG_SMB_SERVER_KERBEROS5
357	server_conf.auth_mechs |= KSMBD_AUTH_KRB5 |
358				KSMBD_AUTH_MSKRB5;
359#endif
360	return 0;
361}
362
363static void server_ctrl_handle_init(struct server_ctrl_struct *ctrl)
364{
365	int ret;
366
367	ret = ksmbd_conn_transport_init();
368	if (ret) {
369		server_queue_ctrl_reset_work();
370		return;
371	}
372
373	WRITE_ONCE(server_conf.state, SERVER_STATE_RUNNING);
374}
375
376static void server_ctrl_handle_reset(struct server_ctrl_struct *ctrl)
377{
378	ksmbd_ipc_soft_reset();
379	ksmbd_conn_transport_destroy();
380	server_conf_free();
381	server_conf_init();
382	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
383}
384
385static void server_ctrl_handle_work(struct work_struct *work)
386{
387	struct server_ctrl_struct *ctrl;
388
389	ctrl = container_of(work, struct server_ctrl_struct, ctrl_work);
390
391	mutex_lock(&ctrl_lock);
392	switch (ctrl->type) {
393	case SERVER_CTRL_TYPE_INIT:
394		server_ctrl_handle_init(ctrl);
395		break;
396	case SERVER_CTRL_TYPE_RESET:
397		server_ctrl_handle_reset(ctrl);
398		break;
399	default:
400		pr_err("Unknown server work type: %d\n", ctrl->type);
401	}
402	mutex_unlock(&ctrl_lock);
403	kfree(ctrl);
404	module_put(THIS_MODULE);
405}
406
407static int __queue_ctrl_work(int type)
408{
409	struct server_ctrl_struct *ctrl;
410
411	ctrl = kmalloc(sizeof(struct server_ctrl_struct), GFP_KERNEL);
412	if (!ctrl)
413		return -ENOMEM;
414
415	__module_get(THIS_MODULE);
416	ctrl->type = type;
417	INIT_WORK(&ctrl->ctrl_work, server_ctrl_handle_work);
418	queue_work(system_long_wq, &ctrl->ctrl_work);
419	return 0;
420}
421
422int server_queue_ctrl_init_work(void)
423{
424	return __queue_ctrl_work(SERVER_CTRL_TYPE_INIT);
425}
426
427int server_queue_ctrl_reset_work(void)
428{
429	return __queue_ctrl_work(SERVER_CTRL_TYPE_RESET);
430}
431
432static ssize_t stats_show(const struct class *class, const struct class_attribute *attr,
433			  char *buf)
434{
435	/*
436	 * Inc this each time you change stats output format,
437	 * so user space will know what to do.
438	 */
439	static int stats_version = 2;
440	static const char * const state[] = {
441		"startup",
442		"running",
443		"reset",
444		"shutdown"
445	};
446	return sysfs_emit(buf, "%d %s %d %lu\n", stats_version,
447			  state[server_conf.state], server_conf.tcp_port,
448			  server_conf.ipc_last_active / HZ);
449}
450
451static ssize_t kill_server_store(const struct class *class,
452				 const struct class_attribute *attr, const char *buf,
453				 size_t len)
454{
455	if (!sysfs_streq(buf, "hard"))
456		return len;
457
458	pr_info("kill command received\n");
459	mutex_lock(&ctrl_lock);
460	WRITE_ONCE(server_conf.state, SERVER_STATE_RESETTING);
461	__module_get(THIS_MODULE);
462	server_ctrl_handle_reset(NULL);
463	module_put(THIS_MODULE);
464	mutex_unlock(&ctrl_lock);
465	return len;
466}
467
468static const char * const debug_type_strings[] = {"smb", "auth", "vfs",
469						  "oplock", "ipc", "conn",
470						  "rdma"};
471
472static ssize_t debug_show(const struct class *class, const struct class_attribute *attr,
473			  char *buf)
474{
475	ssize_t sz = 0;
476	int i, pos = 0;
477
478	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
479		if ((ksmbd_debug_types >> i) & 1) {
480			pos = sysfs_emit_at(buf, sz, "[%s] ", debug_type_strings[i]);
481		} else {
482			pos = sysfs_emit_at(buf, sz, "%s ", debug_type_strings[i]);
483		}
484		sz += pos;
485	}
486	sz += sysfs_emit_at(buf, sz, "\n");
487	return sz;
488}
489
490static ssize_t debug_store(const struct class *class, const struct class_attribute *attr,
491			   const char *buf, size_t len)
492{
493	int i;
494
495	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
496		if (sysfs_streq(buf, "all")) {
497			if (ksmbd_debug_types == KSMBD_DEBUG_ALL)
498				ksmbd_debug_types = 0;
499			else
500				ksmbd_debug_types = KSMBD_DEBUG_ALL;
501			break;
502		}
503
504		if (sysfs_streq(buf, debug_type_strings[i])) {
505			if (ksmbd_debug_types & (1 << i))
506				ksmbd_debug_types &= ~(1 << i);
507			else
508				ksmbd_debug_types |= (1 << i);
509			break;
510		}
511	}
512
513	return len;
514}
515
516static CLASS_ATTR_RO(stats);
517static CLASS_ATTR_WO(kill_server);
518static CLASS_ATTR_RW(debug);
519
520static struct attribute *ksmbd_control_class_attrs[] = {
521	&class_attr_stats.attr,
522	&class_attr_kill_server.attr,
523	&class_attr_debug.attr,
524	NULL,
525};
526ATTRIBUTE_GROUPS(ksmbd_control_class);
527
528static struct class ksmbd_control_class = {
529	.name		= "ksmbd-control",
530	.class_groups	= ksmbd_control_class_groups,
531};
532
533static int ksmbd_server_shutdown(void)
534{
535	WRITE_ONCE(server_conf.state, SERVER_STATE_SHUTTING_DOWN);
536
537	class_unregister(&ksmbd_control_class);
538	ksmbd_workqueue_destroy();
539	ksmbd_ipc_release();
540	ksmbd_conn_transport_destroy();
541	ksmbd_crypto_destroy();
542	ksmbd_free_global_file_table();
543	destroy_lease_table(NULL);
544	ksmbd_work_pool_destroy();
545	ksmbd_exit_file_cache();
546	server_conf_free();
547	return 0;
548}
549
550static int __init ksmbd_server_init(void)
551{
552	int ret;
553
554	ret = class_register(&ksmbd_control_class);
555	if (ret) {
556		pr_err("Unable to register ksmbd-control class\n");
557		return ret;
558	}
559
560	ksmbd_server_tcp_callbacks_init();
561
562	ret = server_conf_init();
563	if (ret)
564		goto err_unregister;
565
566	ret = ksmbd_work_pool_init();
567	if (ret)
568		goto err_unregister;
569
570	ret = ksmbd_init_file_cache();
571	if (ret)
572		goto err_destroy_work_pools;
573
574	ret = ksmbd_ipc_init();
575	if (ret)
576		goto err_exit_file_cache;
577
578	ret = ksmbd_init_global_file_table();
579	if (ret)
580		goto err_ipc_release;
581
582	ret = ksmbd_inode_hash_init();
583	if (ret)
584		goto err_destroy_file_table;
585
586	ret = ksmbd_crypto_create();
587	if (ret)
588		goto err_release_inode_hash;
589
590	ret = ksmbd_workqueue_init();
591	if (ret)
592		goto err_crypto_destroy;
593
594	return 0;
595
596err_crypto_destroy:
597	ksmbd_crypto_destroy();
598err_release_inode_hash:
599	ksmbd_release_inode_hash();
600err_destroy_file_table:
601	ksmbd_free_global_file_table();
602err_ipc_release:
603	ksmbd_ipc_release();
604err_exit_file_cache:
605	ksmbd_exit_file_cache();
606err_destroy_work_pools:
607	ksmbd_work_pool_destroy();
608err_unregister:
609	class_unregister(&ksmbd_control_class);
610
611	return ret;
612}
613
614/**
615 * ksmbd_server_exit() - shutdown forker thread and free memory at module exit
616 */
617static void __exit ksmbd_server_exit(void)
618{
619	ksmbd_server_shutdown();
620	rcu_barrier();
621	ksmbd_release_inode_hash();
622}
623
624MODULE_AUTHOR("Namjae Jeon <linkinjeon@kernel.org>");
625MODULE_DESCRIPTION("Linux kernel CIFS/SMB SERVER");
626MODULE_LICENSE("GPL");
627MODULE_SOFTDEP("pre: ecb");
628MODULE_SOFTDEP("pre: hmac");
629MODULE_SOFTDEP("pre: md5");
630MODULE_SOFTDEP("pre: nls");
631MODULE_SOFTDEP("pre: aes");
632MODULE_SOFTDEP("pre: cmac");
633MODULE_SOFTDEP("pre: sha256");
634MODULE_SOFTDEP("pre: sha512");
635MODULE_SOFTDEP("pre: aead2");
636MODULE_SOFTDEP("pre: ccm");
637MODULE_SOFTDEP("pre: gcm");
638MODULE_SOFTDEP("pre: crc32");
639module_init(ksmbd_server_init)
640module_exit(ksmbd_server_exit)