1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2016 Namjae Jeon <namjae.jeon@protocolfreedom.org>
4 * Copyright (C) 2018 Samsung Electronics Co., Ltd.
5 */
6
7 #include <linux/mutex.h>
8 #include <linux/freezer.h>
9 #include <linux/module.h>
10
11 #include "server.h"
12 #include "smb_common.h"
13 #include "mgmt/ksmbd_ida.h"
14 #include "connection.h"
15 #include "transport_tcp.h"
16 #include "transport_rdma.h"
17
18 static DEFINE_MUTEX(init_lock);
19
20 static struct ksmbd_conn_ops default_conn_ops;
21
22 LIST_HEAD(conn_list);
23 DECLARE_RWSEM(conn_list_lock);
24
25 /**
26 * ksmbd_conn_free() - free resources of the connection instance
27 *
28 * @conn: connection instance to be cleand up
29 *
30 * During the thread termination, the corresponding conn instance
31 * resources(sock/memory) are released and finally the conn object is freed.
32 */
ksmbd_conn_free(struct ksmbd_conn * conn)33 void ksmbd_conn_free(struct ksmbd_conn *conn)
34 {
35 down_write(&conn_list_lock);
36 list_del(&conn->conns_list);
37 up_write(&conn_list_lock);
38
39 xa_destroy(&conn->sessions);
40 kvfree(conn->request_buf);
41 kfree(conn->preauth_info);
42 kfree(conn);
43 }
44
45 /**
46 * ksmbd_conn_alloc() - initialize a new connection instance
47 *
48 * Return: ksmbd_conn struct on success, otherwise NULL
49 */
ksmbd_conn_alloc(void)50 struct ksmbd_conn *ksmbd_conn_alloc(void)
51 {
52 struct ksmbd_conn *conn;
53
54 conn = kzalloc(sizeof(struct ksmbd_conn), GFP_KERNEL);
55 if (!conn)
56 return NULL;
57
58 conn->need_neg = true;
59 ksmbd_conn_set_new(conn);
60 conn->local_nls = load_nls("utf8");
61 if (!conn->local_nls)
62 conn->local_nls = load_nls_default();
63 if (IS_ENABLED(CONFIG_UNICODE))
64 conn->um = utf8_load(UNICODE_AGE(12, 1, 0));
65 else
66 conn->um = ERR_PTR(-EOPNOTSUPP);
67 if (IS_ERR(conn->um))
68 conn->um = NULL;
69 atomic_set(&conn->req_running, 0);
70 atomic_set(&conn->r_count, 0);
71 conn->total_credits = 1;
72 conn->outstanding_credits = 0;
73
74 init_waitqueue_head(&conn->req_running_q);
75 init_waitqueue_head(&conn->r_count_q);
76 INIT_LIST_HEAD(&conn->conns_list);
77 INIT_LIST_HEAD(&conn->requests);
78 INIT_LIST_HEAD(&conn->async_requests);
79 spin_lock_init(&conn->request_lock);
80 spin_lock_init(&conn->credits_lock);
81 ida_init(&conn->async_ida);
82 xa_init(&conn->sessions);
83
84 spin_lock_init(&conn->llist_lock);
85 INIT_LIST_HEAD(&conn->lock_list);
86
87 init_rwsem(&conn->session_lock);
88
89 down_write(&conn_list_lock);
90 list_add(&conn->conns_list, &conn_list);
91 up_write(&conn_list_lock);
92 return conn;
93 }
94
ksmbd_conn_lookup_dialect(struct ksmbd_conn * c)95 bool ksmbd_conn_lookup_dialect(struct ksmbd_conn *c)
96 {
97 struct ksmbd_conn *t;
98 bool ret = false;
99
100 down_read(&conn_list_lock);
101 list_for_each_entry(t, &conn_list, conns_list) {
102 if (memcmp(t->ClientGUID, c->ClientGUID, SMB2_CLIENT_GUID_SIZE))
103 continue;
104
105 ret = true;
106 break;
107 }
108 up_read(&conn_list_lock);
109 return ret;
110 }
111
ksmbd_conn_enqueue_request(struct ksmbd_work * work)112 void ksmbd_conn_enqueue_request(struct ksmbd_work *work)
113 {
114 struct ksmbd_conn *conn = work->conn;
115 struct list_head *requests_queue = NULL;
116
117 if (conn->ops->get_cmd_val(work) != SMB2_CANCEL_HE)
118 requests_queue = &conn->requests;
119
120 if (requests_queue) {
121 atomic_inc(&conn->req_running);
122 spin_lock(&conn->request_lock);
123 list_add_tail(&work->request_entry, requests_queue);
124 spin_unlock(&conn->request_lock);
125 }
126 }
127
ksmbd_conn_try_dequeue_request(struct ksmbd_work * work)128 void ksmbd_conn_try_dequeue_request(struct ksmbd_work *work)
129 {
130 struct ksmbd_conn *conn = work->conn;
131
132 if (list_empty(&work->request_entry) &&
133 list_empty(&work->async_request_entry))
134 return;
135
136 atomic_dec(&conn->req_running);
137 spin_lock(&conn->request_lock);
138 list_del_init(&work->request_entry);
139 spin_unlock(&conn->request_lock);
140 if (work->asynchronous)
141 release_async_work(work);
142
143 wake_up_all(&conn->req_running_q);
144 }
145
ksmbd_conn_lock(struct ksmbd_conn * conn)146 void ksmbd_conn_lock(struct ksmbd_conn *conn)
147 {
148 mutex_lock(&conn->srv_mutex);
149 }
150
ksmbd_conn_unlock(struct ksmbd_conn * conn)151 void ksmbd_conn_unlock(struct ksmbd_conn *conn)
152 {
153 mutex_unlock(&conn->srv_mutex);
154 }
155
ksmbd_all_conn_set_status(u64 sess_id,u32 status)156 void ksmbd_all_conn_set_status(u64 sess_id, u32 status)
157 {
158 struct ksmbd_conn *conn;
159
160 down_read(&conn_list_lock);
161 list_for_each_entry(conn, &conn_list, conns_list) {
162 if (conn->binding || xa_load(&conn->sessions, sess_id))
163 WRITE_ONCE(conn->status, status);
164 }
165 up_read(&conn_list_lock);
166 }
167
ksmbd_conn_wait_idle(struct ksmbd_conn * conn,u64 sess_id)168 void ksmbd_conn_wait_idle(struct ksmbd_conn *conn, u64 sess_id)
169 {
170 struct ksmbd_conn *bind_conn;
171
172 wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
173
174 down_read(&conn_list_lock);
175 list_for_each_entry(bind_conn, &conn_list, conns_list) {
176 if (bind_conn == conn)
177 continue;
178
179 if ((bind_conn->binding || xa_load(&bind_conn->sessions, sess_id)) &&
180 !ksmbd_conn_releasing(bind_conn) &&
181 atomic_read(&bind_conn->req_running)) {
182 wait_event(bind_conn->req_running_q,
183 atomic_read(&bind_conn->req_running) == 0);
184 }
185 }
186 up_read(&conn_list_lock);
187 }
188
ksmbd_conn_write(struct ksmbd_work * work)189 int ksmbd_conn_write(struct ksmbd_work *work)
190 {
191 struct ksmbd_conn *conn = work->conn;
192 int sent;
193
194 if (!work->response_buf) {
195 pr_err("NULL response header\n");
196 return -EINVAL;
197 }
198
199 if (work->send_no_response)
200 return 0;
201
202 if (!work->iov_idx)
203 return -EINVAL;
204
205 ksmbd_conn_lock(conn);
206 sent = conn->transport->ops->writev(conn->transport, work->iov,
207 work->iov_cnt,
208 get_rfc1002_len(work->iov[0].iov_base) + 4,
209 work->need_invalidate_rkey,
210 work->remote_key);
211 ksmbd_conn_unlock(conn);
212
213 if (sent < 0) {
214 pr_err("Failed to send message: %d\n", sent);
215 return sent;
216 }
217
218 return 0;
219 }
220
ksmbd_conn_rdma_read(struct ksmbd_conn * conn,void * buf,unsigned int buflen,struct smb2_buffer_desc_v1 * desc,unsigned int desc_len)221 int ksmbd_conn_rdma_read(struct ksmbd_conn *conn,
222 void *buf, unsigned int buflen,
223 struct smb2_buffer_desc_v1 *desc,
224 unsigned int desc_len)
225 {
226 int ret = -EINVAL;
227
228 if (conn->transport->ops->rdma_read)
229 ret = conn->transport->ops->rdma_read(conn->transport,
230 buf, buflen,
231 desc, desc_len);
232 return ret;
233 }
234
ksmbd_conn_rdma_write(struct ksmbd_conn * conn,void * buf,unsigned int buflen,struct smb2_buffer_desc_v1 * desc,unsigned int desc_len)235 int ksmbd_conn_rdma_write(struct ksmbd_conn *conn,
236 void *buf, unsigned int buflen,
237 struct smb2_buffer_desc_v1 *desc,
238 unsigned int desc_len)
239 {
240 int ret = -EINVAL;
241
242 if (conn->transport->ops->rdma_write)
243 ret = conn->transport->ops->rdma_write(conn->transport,
244 buf, buflen,
245 desc, desc_len);
246 return ret;
247 }
248
ksmbd_conn_alive(struct ksmbd_conn * conn)249 bool ksmbd_conn_alive(struct ksmbd_conn *conn)
250 {
251 if (!ksmbd_server_running())
252 return false;
253
254 if (ksmbd_conn_exiting(conn))
255 return false;
256
257 if (kthread_should_stop())
258 return false;
259
260 if (atomic_read(&conn->stats.open_files_count) > 0)
261 return true;
262
263 /*
264 * Stop current session if the time that get last request from client
265 * is bigger than deadtime user configured and opening file count is
266 * zero.
267 */
268 if (server_conf.deadtime > 0 &&
269 time_after(jiffies, conn->last_active + server_conf.deadtime)) {
270 ksmbd_debug(CONN, "No response from client in %lu minutes\n",
271 server_conf.deadtime / SMB_ECHO_INTERVAL);
272 return false;
273 }
274 return true;
275 }
276
277 #define SMB1_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb_hdr))
278 #define SMB2_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb2_hdr) + 4)
279
280 /**
281 * ksmbd_conn_handler_loop() - session thread to listen on new smb requests
282 * @p: connection instance
283 *
284 * One thread each per connection
285 *
286 * Return: 0 on success
287 */
ksmbd_conn_handler_loop(void * p)288 int ksmbd_conn_handler_loop(void *p)
289 {
290 struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
291 struct ksmbd_transport *t = conn->transport;
292 unsigned int pdu_size, max_allowed_pdu_size;
293 char hdr_buf[4] = {0,};
294 int size;
295
296 mutex_init(&conn->srv_mutex);
297 __module_get(THIS_MODULE);
298
299 if (t->ops->prepare && t->ops->prepare(t))
300 goto out;
301
302 conn->last_active = jiffies;
303 while (ksmbd_conn_alive(conn)) {
304 if (try_to_freeze())
305 continue;
306
307 kvfree(conn->request_buf);
308 conn->request_buf = NULL;
309
310 size = t->ops->read(t, hdr_buf, sizeof(hdr_buf), -1);
311 if (size != sizeof(hdr_buf))
312 break;
313
314 pdu_size = get_rfc1002_len(hdr_buf);
315 ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
316
317 if (ksmbd_conn_good(conn))
318 max_allowed_pdu_size =
319 SMB3_MAX_MSGSIZE + conn->vals->max_write_size;
320 else
321 max_allowed_pdu_size = SMB3_MAX_MSGSIZE;
322
323 if (pdu_size > max_allowed_pdu_size) {
324 pr_err_ratelimited("PDU length(%u) exceeded maximum allowed pdu size(%u) on connection(%d)\n",
325 pdu_size, max_allowed_pdu_size,
326 READ_ONCE(conn->status));
327 break;
328 }
329
330 /*
331 * Check maximum pdu size(0x00FFFFFF).
332 */
333 if (pdu_size > MAX_STREAM_PROT_LEN)
334 break;
335
336 if (pdu_size < SMB1_MIN_SUPPORTED_HEADER_SIZE)
337 break;
338
339 /* 4 for rfc1002 length field */
340 /* 1 for implied bcc[0] */
341 size = pdu_size + 4 + 1;
342 conn->request_buf = kvmalloc(size, GFP_KERNEL);
343 if (!conn->request_buf)
344 break;
345
346 memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
347
348 /*
349 * We already read 4 bytes to find out PDU size, now
350 * read in PDU
351 */
352 size = t->ops->read(t, conn->request_buf + 4, pdu_size, 2);
353 if (size < 0) {
354 pr_err("sock_read failed: %d\n", size);
355 break;
356 }
357
358 if (size != pdu_size) {
359 pr_err("PDU error. Read: %d, Expected: %d\n",
360 size, pdu_size);
361 continue;
362 }
363
364 if (!ksmbd_smb_request(conn))
365 break;
366
367 if (((struct smb2_hdr *)smb2_get_msg(conn->request_buf))->ProtocolId ==
368 SMB2_PROTO_NUMBER) {
369 if (pdu_size < SMB2_MIN_SUPPORTED_HEADER_SIZE)
370 break;
371 }
372
373 if (!default_conn_ops.process_fn) {
374 pr_err("No connection request callback\n");
375 break;
376 }
377
378 if (default_conn_ops.process_fn(conn)) {
379 pr_err("Cannot handle request\n");
380 break;
381 }
382 }
383
384 out:
385 ksmbd_conn_set_releasing(conn);
386 /* Wait till all reference dropped to the Server object*/
387 wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);
388
389 if (IS_ENABLED(CONFIG_UNICODE))
390 utf8_unload(conn->um);
391 unload_nls(conn->local_nls);
392 if (default_conn_ops.terminate_fn)
393 default_conn_ops.terminate_fn(conn);
394 t->ops->disconnect(t);
395 module_put(THIS_MODULE);
396 return 0;
397 }
398
ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops * ops)399 void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
400 {
401 default_conn_ops.process_fn = ops->process_fn;
402 default_conn_ops.terminate_fn = ops->terminate_fn;
403 }
404
ksmbd_conn_transport_init(void)405 int ksmbd_conn_transport_init(void)
406 {
407 int ret;
408
409 mutex_lock(&init_lock);
410 ret = ksmbd_tcp_init();
411 if (ret) {
412 pr_err("Failed to init TCP subsystem: %d\n", ret);
413 goto out;
414 }
415
416 ret = ksmbd_rdma_init();
417 if (ret) {
418 pr_err("Failed to init RDMA subsystem: %d\n", ret);
419 goto out;
420 }
421 out:
422 mutex_unlock(&init_lock);
423 return ret;
424 }
425
stop_sessions(void)426 static void stop_sessions(void)
427 {
428 struct ksmbd_conn *conn;
429 struct ksmbd_transport *t;
430
431 again:
432 down_read(&conn_list_lock);
433 list_for_each_entry(conn, &conn_list, conns_list) {
434 struct task_struct *task;
435
436 t = conn->transport;
437 task = t->handler;
438 if (task)
439 ksmbd_debug(CONN, "Stop session handler %s/%d\n",
440 task->comm, task_pid_nr(task));
441 ksmbd_conn_set_exiting(conn);
442 if (t->ops->shutdown) {
443 up_read(&conn_list_lock);
444 t->ops->shutdown(t);
445 down_read(&conn_list_lock);
446 }
447 }
448 up_read(&conn_list_lock);
449
450 if (!list_empty(&conn_list)) {
451 schedule_timeout_interruptible(HZ / 10); /* 100ms */
452 goto again;
453 }
454 }
455
ksmbd_conn_transport_destroy(void)456 void ksmbd_conn_transport_destroy(void)
457 {
458 mutex_lock(&init_lock);
459 ksmbd_tcp_destroy();
460 ksmbd_rdma_destroy();
461 stop_sessions();
462 mutex_unlock(&init_lock);
463 }
464