xref: /linux/fs/smb/server/mgmt/user_session.c (revision f694f30e81c4ade358eb8c75273bac1a48f0cb8f) 
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
4  */
5 
6 #include <linux/list.h>
7 #include <linux/slab.h>
8 #include <linux/rwsem.h>
9 #include <linux/xarray.h>
10 
11 #include "ksmbd_ida.h"
12 #include "user_session.h"
13 #include "user_config.h"
14 #include "tree_connect.h"
15 #include "../transport_ipc.h"
16 #include "../connection.h"
17 #include "../vfs_cache.h"
18 
19 static DEFINE_IDA(session_ida);
20 
21 #define SESSION_HASH_BITS		3
22 static DEFINE_HASHTABLE(sessions_table, SESSION_HASH_BITS);
23 static DECLARE_RWSEM(sessions_table_lock);
24 
25 struct ksmbd_session_rpc {
26 	int			id;
27 	unsigned int		method;
28 };
29 
30 static void free_channel_list(struct ksmbd_session *sess)
31 {
32 	struct channel *chann;
33 	unsigned long index;
34 
35 	xa_for_each(&sess->ksmbd_chann_list, index, chann) {
36 		xa_erase(&sess->ksmbd_chann_list, index);
37 		kfree(chann);
38 	}
39 
40 	xa_destroy(&sess->ksmbd_chann_list);
41 }
42 
43 static void __session_rpc_close(struct ksmbd_session *sess,
44 				struct ksmbd_session_rpc *entry)
45 {
46 	struct ksmbd_rpc_command *resp;
47 
48 	resp = ksmbd_rpc_close(sess, entry->id);
49 	if (!resp)
50 		pr_err("Unable to close RPC pipe %d\n", entry->id);
51 
52 	kvfree(resp);
53 	ksmbd_rpc_id_free(entry->id);
54 	kfree(entry);
55 }
56 
57 static void ksmbd_session_rpc_clear_list(struct ksmbd_session *sess)
58 {
59 	struct ksmbd_session_rpc *entry;
60 	long index;
61 
62 	xa_for_each(&sess->rpc_handle_list, index, entry) {
63 		xa_erase(&sess->rpc_handle_list, index);
64 		__session_rpc_close(sess, entry);
65 	}
66 
67 	xa_destroy(&sess->rpc_handle_list);
68 }
69 
70 static int __rpc_method(char *rpc_name)
71 {
72 	if (!strcmp(rpc_name, "\\srvsvc") || !strcmp(rpc_name, "srvsvc"))
73 		return KSMBD_RPC_SRVSVC_METHOD_INVOKE;
74 
75 	if (!strcmp(rpc_name, "\\wkssvc") || !strcmp(rpc_name, "wkssvc"))
76 		return KSMBD_RPC_WKSSVC_METHOD_INVOKE;
77 
78 	if (!strcmp(rpc_name, "LANMAN") || !strcmp(rpc_name, "lanman"))
79 		return KSMBD_RPC_RAP_METHOD;
80 
81 	if (!strcmp(rpc_name, "\\samr") || !strcmp(rpc_name, "samr"))
82 		return KSMBD_RPC_SAMR_METHOD_INVOKE;
83 
84 	if (!strcmp(rpc_name, "\\lsarpc") || !strcmp(rpc_name, "lsarpc"))
85 		return KSMBD_RPC_LSARPC_METHOD_INVOKE;
86 
87 	pr_err("Unsupported RPC: %s\n", rpc_name);
88 	return 0;
89 }
90 
91 int ksmbd_session_rpc_open(struct ksmbd_session *sess, char *rpc_name)
92 {
93 	struct ksmbd_session_rpc *entry, *old;
94 	struct ksmbd_rpc_command *resp;
95 	int method;
96 
97 	method = __rpc_method(rpc_name);
98 	if (!method)
99 		return -EINVAL;
100 
101 	entry = kzalloc(sizeof(struct ksmbd_session_rpc), KSMBD_DEFAULT_GFP);
102 	if (!entry)
103 		return -ENOMEM;
104 
105 	entry->method = method;
106 	entry->id = ksmbd_ipc_id_alloc();
107 	if (entry->id < 0)
108 		goto free_entry;
109 	old = xa_store(&sess->rpc_handle_list, entry->id, entry, KSMBD_DEFAULT_GFP);
110 	if (xa_is_err(old))
111 		goto free_id;
112 
113 	resp = ksmbd_rpc_open(sess, entry->id);
114 	if (!resp)
115 		goto erase_xa;
116 
117 	kvfree(resp);
118 	return entry->id;
119 erase_xa:
120 	xa_erase(&sess->rpc_handle_list, entry->id);
121 free_id:
122 	ksmbd_rpc_id_free(entry->id);
123 free_entry:
124 	kfree(entry);
125 	return -EINVAL;
126 }
127 
128 void ksmbd_session_rpc_close(struct ksmbd_session *sess, int id)
129 {
130 	struct ksmbd_session_rpc *entry;
131 
132 	entry = xa_erase(&sess->rpc_handle_list, id);
133 	if (entry)
134 		__session_rpc_close(sess, entry);
135 }
136 
137 int ksmbd_session_rpc_method(struct ksmbd_session *sess, int id)
138 {
139 	struct ksmbd_session_rpc *entry;
140 
141 	entry = xa_load(&sess->rpc_handle_list, id);
142 	return entry ? entry->method : 0;
143 }
144 
145 void ksmbd_session_destroy(struct ksmbd_session *sess)
146 {
147 	if (!sess)
148 		return;
149 
150 	if (sess->user)
151 		ksmbd_free_user(sess->user);
152 
153 	ksmbd_tree_conn_session_logoff(sess);
154 	ksmbd_destroy_file_table(&sess->file_table);
155 	ksmbd_launch_ksmbd_durable_scavenger();
156 	ksmbd_session_rpc_clear_list(sess);
157 	free_channel_list(sess);
158 	kfree(sess->Preauth_HashValue);
159 	ksmbd_release_id(&session_ida, sess->id);
160 	kfree(sess);
161 }
162 
163 struct ksmbd_session *__session_lookup(unsigned long long id)
164 {
165 	struct ksmbd_session *sess;
166 
167 	hash_for_each_possible(sessions_table, sess, hlist, id) {
168 		if (id == sess->id) {
169 			sess->last_active = jiffies;
170 			return sess;
171 		}
172 	}
173 	return NULL;
174 }
175 
176 static void ksmbd_expire_session(struct ksmbd_conn *conn)
177 {
178 	unsigned long id;
179 	struct ksmbd_session *sess;
180 
181 	down_write(&sessions_table_lock);
182 	down_write(&conn->session_lock);
183 	xa_for_each(&conn->sessions, id, sess) {
184 		if (atomic_read(&sess->refcnt) <= 1 &&
185 		    (sess->state != SMB2_SESSION_VALID ||
186 		     time_after(jiffies,
187 			       sess->last_active + SMB2_SESSION_TIMEOUT))) {
188 			xa_erase(&conn->sessions, sess->id);
189 			hash_del(&sess->hlist);
190 			ksmbd_session_destroy(sess);
191 			continue;
192 		}
193 	}
194 	up_write(&conn->session_lock);
195 	up_write(&sessions_table_lock);
196 }
197 
198 int ksmbd_session_register(struct ksmbd_conn *conn,
199 			   struct ksmbd_session *sess)
200 {
201 	sess->dialect = conn->dialect;
202 	memcpy(sess->ClientGUID, conn->ClientGUID, SMB2_CLIENT_GUID_SIZE);
203 	ksmbd_expire_session(conn);
204 	return xa_err(xa_store(&conn->sessions, sess->id, sess, KSMBD_DEFAULT_GFP));
205 }
206 
207 static int ksmbd_chann_del(struct ksmbd_conn *conn, struct ksmbd_session *sess)
208 {
209 	struct channel *chann;
210 
211 	chann = xa_erase(&sess->ksmbd_chann_list, (long)conn);
212 	if (!chann)
213 		return -ENOENT;
214 
215 	kfree(chann);
216 	return 0;
217 }
218 
219 void ksmbd_sessions_deregister(struct ksmbd_conn *conn)
220 {
221 	struct ksmbd_session *sess;
222 	unsigned long id;
223 
224 	down_write(&sessions_table_lock);
225 	if (conn->binding) {
226 		int bkt;
227 		struct hlist_node *tmp;
228 
229 		hash_for_each_safe(sessions_table, bkt, tmp, sess, hlist) {
230 			if (!ksmbd_chann_del(conn, sess) &&
231 			    xa_empty(&sess->ksmbd_chann_list)) {
232 				hash_del(&sess->hlist);
233 				down_write(&conn->session_lock);
234 				xa_erase(&conn->sessions, sess->id);
235 				up_write(&conn->session_lock);
236 				if (atomic_dec_and_test(&sess->refcnt))
237 					ksmbd_session_destroy(sess);
238 			}
239 		}
240 	}
241 
242 	down_write(&conn->session_lock);
243 	xa_for_each(&conn->sessions, id, sess) {
244 		unsigned long chann_id;
245 		struct channel *chann;
246 
247 		xa_for_each(&sess->ksmbd_chann_list, chann_id, chann) {
248 			if (chann->conn != conn)
249 				ksmbd_conn_set_exiting(chann->conn);
250 		}
251 
252 		ksmbd_chann_del(conn, sess);
253 		if (xa_empty(&sess->ksmbd_chann_list)) {
254 			xa_erase(&conn->sessions, sess->id);
255 			hash_del(&sess->hlist);
256 			if (atomic_dec_and_test(&sess->refcnt))
257 				ksmbd_session_destroy(sess);
258 		}
259 	}
260 	up_write(&conn->session_lock);
261 	up_write(&sessions_table_lock);
262 }
263 
264 bool is_ksmbd_session_in_connection(struct ksmbd_conn *conn,
265 				   unsigned long long id)
266 {
267 	struct ksmbd_session *sess;
268 
269 	down_read(&conn->session_lock);
270 	sess = xa_load(&conn->sessions, id);
271 	if (sess) {
272 		up_read(&conn->session_lock);
273 		return true;
274 	}
275 	up_read(&conn->session_lock);
276 
277 	return false;
278 }
279 
280 struct ksmbd_session *ksmbd_session_lookup(struct ksmbd_conn *conn,
281 					   unsigned long long id)
282 {
283 	struct ksmbd_session *sess;
284 
285 	down_read(&conn->session_lock);
286 	sess = xa_load(&conn->sessions, id);
287 	if (sess) {
288 		sess->last_active = jiffies;
289 		ksmbd_user_session_get(sess);
290 	}
291 	up_read(&conn->session_lock);
292 	return sess;
293 }
294 
295 struct ksmbd_session *ksmbd_session_lookup_slowpath(unsigned long long id)
296 {
297 	struct ksmbd_session *sess;
298 
299 	down_read(&sessions_table_lock);
300 	sess = __session_lookup(id);
301 	if (sess)
302 		ksmbd_user_session_get(sess);
303 	up_read(&sessions_table_lock);
304 
305 	return sess;
306 }
307 
308 struct ksmbd_session *ksmbd_session_lookup_all(struct ksmbd_conn *conn,
309 					       unsigned long long id)
310 {
311 	struct ksmbd_session *sess;
312 
313 	sess = ksmbd_session_lookup(conn, id);
314 	if (!sess && conn->binding)
315 		sess = ksmbd_session_lookup_slowpath(id);
316 	if (sess && sess->state != SMB2_SESSION_VALID)
317 		sess = NULL;
318 	return sess;
319 }
320 
321 void ksmbd_user_session_get(struct ksmbd_session *sess)
322 {
323 	atomic_inc(&sess->refcnt);
324 }
325 
326 void ksmbd_user_session_put(struct ksmbd_session *sess)
327 {
328 	if (!sess)
329 		return;
330 
331 	if (atomic_read(&sess->refcnt) <= 0)
332 		WARN_ON(1);
333 	else if (atomic_dec_and_test(&sess->refcnt))
334 		ksmbd_session_destroy(sess);
335 }
336 
337 struct preauth_session *ksmbd_preauth_session_alloc(struct ksmbd_conn *conn,
338 						    u64 sess_id)
339 {
340 	struct preauth_session *sess;
341 
342 	sess = kmalloc(sizeof(struct preauth_session), KSMBD_DEFAULT_GFP);
343 	if (!sess)
344 		return NULL;
345 
346 	sess->id = sess_id;
347 	memcpy(sess->Preauth_HashValue, conn->preauth_info->Preauth_HashValue,
348 	       PREAUTH_HASHVALUE_SIZE);
349 	list_add(&sess->preauth_entry, &conn->preauth_sess_table);
350 
351 	return sess;
352 }
353 
354 void destroy_previous_session(struct ksmbd_conn *conn,
355 			      struct ksmbd_user *user, u64 id)
356 {
357 	struct ksmbd_session *prev_sess;
358 	struct ksmbd_user *prev_user;
359 	int err;
360 
361 	down_write(&sessions_table_lock);
362 	down_write(&conn->session_lock);
363 	prev_sess = __session_lookup(id);
364 	if (!prev_sess || prev_sess->state == SMB2_SESSION_EXPIRED)
365 		goto out;
366 
367 	prev_user = prev_sess->user;
368 	if (!prev_user ||
369 	    strcmp(user->name, prev_user->name) ||
370 	    user->passkey_sz != prev_user->passkey_sz ||
371 	    memcmp(user->passkey, prev_user->passkey, user->passkey_sz))
372 		goto out;
373 
374 	ksmbd_all_conn_set_status(id, KSMBD_SESS_NEED_RECONNECT);
375 	err = ksmbd_conn_wait_idle_sess_id(conn, id);
376 	if (err) {
377 		ksmbd_all_conn_set_status(id, KSMBD_SESS_NEED_SETUP);
378 		goto out;
379 	}
380 
381 	ksmbd_destroy_file_table(&prev_sess->file_table);
382 	prev_sess->state = SMB2_SESSION_EXPIRED;
383 	ksmbd_all_conn_set_status(id, KSMBD_SESS_NEED_SETUP);
384 	ksmbd_launch_ksmbd_durable_scavenger();
385 out:
386 	up_write(&conn->session_lock);
387 	up_write(&sessions_table_lock);
388 }
389 
390 static bool ksmbd_preauth_session_id_match(struct preauth_session *sess,
391 					   unsigned long long id)
392 {
393 	return sess->id == id;
394 }
395 
396 struct preauth_session *ksmbd_preauth_session_lookup(struct ksmbd_conn *conn,
397 						     unsigned long long id)
398 {
399 	struct preauth_session *sess = NULL;
400 
401 	list_for_each_entry(sess, &conn->preauth_sess_table, preauth_entry) {
402 		if (ksmbd_preauth_session_id_match(sess, id))
403 			return sess;
404 	}
405 	return NULL;
406 }
407 
408 static int __init_smb2_session(struct ksmbd_session *sess)
409 {
410 	int id = ksmbd_acquire_smb2_uid(&session_ida);
411 
412 	if (id < 0)
413 		return -EINVAL;
414 	sess->id = id;
415 	return 0;
416 }
417 
418 static struct ksmbd_session *__session_create(int protocol)
419 {
420 	struct ksmbd_session *sess;
421 	int ret;
422 
423 	if (protocol != CIFDS_SESSION_FLAG_SMB2)
424 		return NULL;
425 
426 	sess = kzalloc(sizeof(struct ksmbd_session), KSMBD_DEFAULT_GFP);
427 	if (!sess)
428 		return NULL;
429 
430 	if (ksmbd_init_file_table(&sess->file_table))
431 		goto error;
432 
433 	sess->last_active = jiffies;
434 	sess->state = SMB2_SESSION_IN_PROGRESS;
435 	set_session_flag(sess, protocol);
436 	xa_init(&sess->tree_conns);
437 	xa_init(&sess->ksmbd_chann_list);
438 	xa_init(&sess->rpc_handle_list);
439 	sess->sequence_number = 1;
440 	rwlock_init(&sess->tree_conns_lock);
441 	atomic_set(&sess->refcnt, 2);
442 
443 	ret = __init_smb2_session(sess);
444 	if (ret)
445 		goto error;
446 
447 	ida_init(&sess->tree_conn_ida);
448 
449 	down_write(&sessions_table_lock);
450 	hash_add(sessions_table, &sess->hlist, sess->id);
451 	up_write(&sessions_table_lock);
452 
453 	return sess;
454 
455 error:
456 	ksmbd_session_destroy(sess);
457 	return NULL;
458 }
459 
460 struct ksmbd_session *ksmbd_smb2_session_create(void)
461 {
462 	return __session_create(CIFDS_SESSION_FLAG_SMB2);
463 }
464 
465 int ksmbd_acquire_tree_conn_id(struct ksmbd_session *sess)
466 {
467 	int id = -EINVAL;
468 
469 	if (test_session_flag(sess, CIFDS_SESSION_FLAG_SMB2))
470 		id = ksmbd_acquire_smb2_tid(&sess->tree_conn_ida);
471 
472 	return id;
473 }
474 
475 void ksmbd_release_tree_conn_id(struct ksmbd_session *sess, int id)
476 {
477 	if (id >= 0)
478 		ksmbd_release_id(&sess->tree_conn_ida, id);
479 }
480