xref: /linux/fs/smb/server/mgmt/user_session.c (revision 46e6acfe3501fa938af9c5bd730f0020235b08a2)
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;
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), GFP_KERNEL);
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 	xa_store(&sess->rpc_handle_list, entry->id, entry, GFP_KERNEL);
110 
111 	resp = ksmbd_rpc_open(sess, entry->id);
112 	if (!resp)
113 		goto free_id;
114 
115 	kvfree(resp);
116 	return entry->id;
117 free_id:
118 	xa_erase(&sess->rpc_handle_list, entry->id);
119 	ksmbd_rpc_id_free(entry->id);
120 free_entry:
121 	kfree(entry);
122 	return -EINVAL;
123 }
124 
125 void ksmbd_session_rpc_close(struct ksmbd_session *sess, int id)
126 {
127 	struct ksmbd_session_rpc *entry;
128 
129 	entry = xa_erase(&sess->rpc_handle_list, id);
130 	if (entry)
131 		__session_rpc_close(sess, entry);
132 }
133 
134 int ksmbd_session_rpc_method(struct ksmbd_session *sess, int id)
135 {
136 	struct ksmbd_session_rpc *entry;
137 
138 	entry = xa_load(&sess->rpc_handle_list, id);
139 	return entry ? entry->method : 0;
140 }
141 
142 void ksmbd_session_destroy(struct ksmbd_session *sess)
143 {
144 	if (!sess)
145 		return;
146 
147 	if (sess->user)
148 		ksmbd_free_user(sess->user);
149 
150 	ksmbd_tree_conn_session_logoff(sess);
151 	ksmbd_destroy_file_table(&sess->file_table);
152 	ksmbd_launch_ksmbd_durable_scavenger();
153 	ksmbd_session_rpc_clear_list(sess);
154 	free_channel_list(sess);
155 	kfree(sess->Preauth_HashValue);
156 	ksmbd_release_id(&session_ida, sess->id);
157 	kfree(sess);
158 }
159 
160 struct ksmbd_session *__session_lookup(unsigned long long id)
161 {
162 	struct ksmbd_session *sess;
163 
164 	hash_for_each_possible(sessions_table, sess, hlist, id) {
165 		if (id == sess->id) {
166 			sess->last_active = jiffies;
167 			return sess;
168 		}
169 	}
170 	return NULL;
171 }
172 
173 static void ksmbd_expire_session(struct ksmbd_conn *conn)
174 {
175 	unsigned long id;
176 	struct ksmbd_session *sess;
177 
178 	down_write(&conn->session_lock);
179 	xa_for_each(&conn->sessions, id, sess) {
180 		if (sess->state != SMB2_SESSION_VALID ||
181 		    time_after(jiffies,
182 			       sess->last_active + SMB2_SESSION_TIMEOUT)) {
183 			xa_erase(&conn->sessions, sess->id);
184 			hash_del(&sess->hlist);
185 			ksmbd_session_destroy(sess);
186 			continue;
187 		}
188 	}
189 	up_write(&conn->session_lock);
190 }
191 
192 int ksmbd_session_register(struct ksmbd_conn *conn,
193 			   struct ksmbd_session *sess)
194 {
195 	sess->dialect = conn->dialect;
196 	memcpy(sess->ClientGUID, conn->ClientGUID, SMB2_CLIENT_GUID_SIZE);
197 	ksmbd_expire_session(conn);
198 	return xa_err(xa_store(&conn->sessions, sess->id, sess, GFP_KERNEL));
199 }
200 
201 static int ksmbd_chann_del(struct ksmbd_conn *conn, struct ksmbd_session *sess)
202 {
203 	struct channel *chann;
204 
205 	chann = xa_erase(&sess->ksmbd_chann_list, (long)conn);
206 	if (!chann)
207 		return -ENOENT;
208 
209 	kfree(chann);
210 	return 0;
211 }
212 
213 void ksmbd_sessions_deregister(struct ksmbd_conn *conn)
214 {
215 	struct ksmbd_session *sess;
216 	unsigned long id;
217 
218 	down_write(&sessions_table_lock);
219 	if (conn->binding) {
220 		int bkt;
221 		struct hlist_node *tmp;
222 
223 		hash_for_each_safe(sessions_table, bkt, tmp, sess, hlist) {
224 			if (!ksmbd_chann_del(conn, sess) &&
225 			    xa_empty(&sess->ksmbd_chann_list)) {
226 				hash_del(&sess->hlist);
227 				ksmbd_session_destroy(sess);
228 			}
229 		}
230 	}
231 	up_write(&sessions_table_lock);
232 
233 	down_write(&conn->session_lock);
234 	xa_for_each(&conn->sessions, id, sess) {
235 		unsigned long chann_id;
236 		struct channel *chann;
237 
238 		xa_for_each(&sess->ksmbd_chann_list, chann_id, chann) {
239 			if (chann->conn != conn)
240 				ksmbd_conn_set_exiting(chann->conn);
241 		}
242 
243 		ksmbd_chann_del(conn, sess);
244 		if (xa_empty(&sess->ksmbd_chann_list)) {
245 			xa_erase(&conn->sessions, sess->id);
246 			hash_del(&sess->hlist);
247 			ksmbd_session_destroy(sess);
248 		}
249 	}
250 	up_write(&conn->session_lock);
251 }
252 
253 struct ksmbd_session *ksmbd_session_lookup(struct ksmbd_conn *conn,
254 					   unsigned long long id)
255 {
256 	struct ksmbd_session *sess;
257 
258 	down_read(&conn->session_lock);
259 	sess = xa_load(&conn->sessions, id);
260 	if (sess)
261 		sess->last_active = jiffies;
262 	up_read(&conn->session_lock);
263 	return sess;
264 }
265 
266 struct ksmbd_session *ksmbd_session_lookup_slowpath(unsigned long long id)
267 {
268 	struct ksmbd_session *sess;
269 
270 	down_read(&sessions_table_lock);
271 	sess = __session_lookup(id);
272 	if (sess)
273 		sess->last_active = jiffies;
274 	up_read(&sessions_table_lock);
275 
276 	return sess;
277 }
278 
279 struct ksmbd_session *ksmbd_session_lookup_all(struct ksmbd_conn *conn,
280 					       unsigned long long id)
281 {
282 	struct ksmbd_session *sess;
283 
284 	sess = ksmbd_session_lookup(conn, id);
285 	if (!sess && conn->binding)
286 		sess = ksmbd_session_lookup_slowpath(id);
287 	if (sess && sess->state != SMB2_SESSION_VALID)
288 		sess = NULL;
289 	return sess;
290 }
291 
292 struct preauth_session *ksmbd_preauth_session_alloc(struct ksmbd_conn *conn,
293 						    u64 sess_id)
294 {
295 	struct preauth_session *sess;
296 
297 	sess = kmalloc(sizeof(struct preauth_session), GFP_KERNEL);
298 	if (!sess)
299 		return NULL;
300 
301 	sess->id = sess_id;
302 	memcpy(sess->Preauth_HashValue, conn->preauth_info->Preauth_HashValue,
303 	       PREAUTH_HASHVALUE_SIZE);
304 	list_add(&sess->preauth_entry, &conn->preauth_sess_table);
305 
306 	return sess;
307 }
308 
309 void destroy_previous_session(struct ksmbd_conn *conn,
310 			      struct ksmbd_user *user, u64 id)
311 {
312 	struct ksmbd_session *prev_sess;
313 	struct ksmbd_user *prev_user;
314 
315 	down_write(&sessions_table_lock);
316 	down_write(&conn->session_lock);
317 	prev_sess = __session_lookup(id);
318 	if (!prev_sess || prev_sess->state == SMB2_SESSION_EXPIRED)
319 		goto out;
320 
321 	prev_user = prev_sess->user;
322 	if (!prev_user ||
323 	    strcmp(user->name, prev_user->name) ||
324 	    user->passkey_sz != prev_user->passkey_sz ||
325 	    memcmp(user->passkey, prev_user->passkey, user->passkey_sz))
326 		goto out;
327 
328 	ksmbd_destroy_file_table(&prev_sess->file_table);
329 	prev_sess->state = SMB2_SESSION_EXPIRED;
330 	ksmbd_launch_ksmbd_durable_scavenger();
331 out:
332 	up_write(&conn->session_lock);
333 	up_write(&sessions_table_lock);
334 }
335 
336 static bool ksmbd_preauth_session_id_match(struct preauth_session *sess,
337 					   unsigned long long id)
338 {
339 	return sess->id == id;
340 }
341 
342 struct preauth_session *ksmbd_preauth_session_lookup(struct ksmbd_conn *conn,
343 						     unsigned long long id)
344 {
345 	struct preauth_session *sess = NULL;
346 
347 	list_for_each_entry(sess, &conn->preauth_sess_table, preauth_entry) {
348 		if (ksmbd_preauth_session_id_match(sess, id))
349 			return sess;
350 	}
351 	return NULL;
352 }
353 
354 static int __init_smb2_session(struct ksmbd_session *sess)
355 {
356 	int id = ksmbd_acquire_smb2_uid(&session_ida);
357 
358 	if (id < 0)
359 		return -EINVAL;
360 	sess->id = id;
361 	return 0;
362 }
363 
364 static struct ksmbd_session *__session_create(int protocol)
365 {
366 	struct ksmbd_session *sess;
367 	int ret;
368 
369 	if (protocol != CIFDS_SESSION_FLAG_SMB2)
370 		return NULL;
371 
372 	sess = kzalloc(sizeof(struct ksmbd_session), GFP_KERNEL);
373 	if (!sess)
374 		return NULL;
375 
376 	if (ksmbd_init_file_table(&sess->file_table))
377 		goto error;
378 
379 	sess->last_active = jiffies;
380 	sess->state = SMB2_SESSION_IN_PROGRESS;
381 	set_session_flag(sess, protocol);
382 	xa_init(&sess->tree_conns);
383 	xa_init(&sess->ksmbd_chann_list);
384 	xa_init(&sess->rpc_handle_list);
385 	sess->sequence_number = 1;
386 	rwlock_init(&sess->tree_conns_lock);
387 
388 	ret = __init_smb2_session(sess);
389 	if (ret)
390 		goto error;
391 
392 	ida_init(&sess->tree_conn_ida);
393 
394 	down_write(&sessions_table_lock);
395 	hash_add(sessions_table, &sess->hlist, sess->id);
396 	up_write(&sessions_table_lock);
397 
398 	return sess;
399 
400 error:
401 	ksmbd_session_destroy(sess);
402 	return NULL;
403 }
404 
405 struct ksmbd_session *ksmbd_smb2_session_create(void)
406 {
407 	return __session_create(CIFDS_SESSION_FLAG_SMB2);
408 }
409 
410 int ksmbd_acquire_tree_conn_id(struct ksmbd_session *sess)
411 {
412 	int id = -EINVAL;
413 
414 	if (test_session_flag(sess, CIFDS_SESSION_FLAG_SMB2))
415 		id = ksmbd_acquire_smb2_tid(&sess->tree_conn_ida);
416 
417 	return id;
418 }
419 
420 void ksmbd_release_tree_conn_id(struct ksmbd_session *sess, int id)
421 {
422 	if (id >= 0)
423 		ksmbd_release_id(&sess->tree_conn_ida, id);
424 }
425