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)168 void ksmbd_conn_wait_idle(struct ksmbd_conn *conn)
169 {
170 wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
171 }
172
ksmbd_conn_wait_idle_sess_id(struct ksmbd_conn * curr_conn,u64 sess_id)173 int ksmbd_conn_wait_idle_sess_id(struct ksmbd_conn *curr_conn, u64 sess_id)
174 {
175 struct ksmbd_conn *conn;
176 int rc, retry_count = 0, max_timeout = 120;
177 int rcount = 1;
178
179 retry_idle:
180 if (retry_count >= max_timeout)
181 return -EIO;
182
183 down_read(&conn_list_lock);
184 list_for_each_entry(conn, &conn_list, conns_list) {
185 if (conn->binding || xa_load(&conn->sessions, sess_id)) {
186 if (conn == curr_conn)
187 rcount = 2;
188 if (atomic_read(&conn->req_running) >= rcount) {
189 rc = wait_event_timeout(conn->req_running_q,
190 atomic_read(&conn->req_running) < rcount,
191 HZ);
192 if (!rc) {
193 up_read(&conn_list_lock);
194 retry_count++;
195 goto retry_idle;
196 }
197 }
198 }
199 }
200 up_read(&conn_list_lock);
201
202 return 0;
203 }
204
ksmbd_conn_write(struct ksmbd_work * work)205 int ksmbd_conn_write(struct ksmbd_work *work)
206 {
207 struct ksmbd_conn *conn = work->conn;
208 int sent;
209
210 if (!work->response_buf) {
211 pr_err("NULL response header\n");
212 return -EINVAL;
213 }
214
215 if (work->send_no_response)
216 return 0;
217
218 if (!work->iov_idx)
219 return -EINVAL;
220
221 ksmbd_conn_lock(conn);
222 sent = conn->transport->ops->writev(conn->transport, work->iov,
223 work->iov_cnt,
224 get_rfc1002_len(work->iov[0].iov_base) + 4,
225 work->need_invalidate_rkey,
226 work->remote_key);
227 ksmbd_conn_unlock(conn);
228
229 if (sent < 0) {
230 pr_err("Failed to send message: %d\n", sent);
231 return sent;
232 }
233
234 return 0;
235 }
236
ksmbd_conn_rdma_read(struct ksmbd_conn * conn,void * buf,unsigned int buflen,struct smb2_buffer_desc_v1 * desc,unsigned int desc_len)237 int ksmbd_conn_rdma_read(struct ksmbd_conn *conn,
238 void *buf, unsigned int buflen,
239 struct smb2_buffer_desc_v1 *desc,
240 unsigned int desc_len)
241 {
242 int ret = -EINVAL;
243
244 if (conn->transport->ops->rdma_read)
245 ret = conn->transport->ops->rdma_read(conn->transport,
246 buf, buflen,
247 desc, desc_len);
248 return ret;
249 }
250
ksmbd_conn_rdma_write(struct ksmbd_conn * conn,void * buf,unsigned int buflen,struct smb2_buffer_desc_v1 * desc,unsigned int desc_len)251 int ksmbd_conn_rdma_write(struct ksmbd_conn *conn,
252 void *buf, unsigned int buflen,
253 struct smb2_buffer_desc_v1 *desc,
254 unsigned int desc_len)
255 {
256 int ret = -EINVAL;
257
258 if (conn->transport->ops->rdma_write)
259 ret = conn->transport->ops->rdma_write(conn->transport,
260 buf, buflen,
261 desc, desc_len);
262 return ret;
263 }
264
ksmbd_conn_alive(struct ksmbd_conn * conn)265 bool ksmbd_conn_alive(struct ksmbd_conn *conn)
266 {
267 if (!ksmbd_server_running())
268 return false;
269
270 if (ksmbd_conn_exiting(conn))
271 return false;
272
273 if (kthread_should_stop())
274 return false;
275
276 if (atomic_read(&conn->stats.open_files_count) > 0)
277 return true;
278
279 /*
280 * Stop current session if the time that get last request from client
281 * is bigger than deadtime user configured and opening file count is
282 * zero.
283 */
284 if (server_conf.deadtime > 0 &&
285 time_after(jiffies, conn->last_active + server_conf.deadtime)) {
286 ksmbd_debug(CONN, "No response from client in %lu minutes\n",
287 server_conf.deadtime / SMB_ECHO_INTERVAL);
288 return false;
289 }
290 return true;
291 }
292
293 #define SMB1_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb_hdr))
294 #define SMB2_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb2_hdr) + 4)
295
296 /**
297 * ksmbd_conn_handler_loop() - session thread to listen on new smb requests
298 * @p: connection instance
299 *
300 * One thread each per connection
301 *
302 * Return: 0 on success
303 */
ksmbd_conn_handler_loop(void * p)304 int ksmbd_conn_handler_loop(void *p)
305 {
306 struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
307 struct ksmbd_transport *t = conn->transport;
308 unsigned int pdu_size, max_allowed_pdu_size;
309 char hdr_buf[4] = {0,};
310 int size;
311
312 mutex_init(&conn->srv_mutex);
313 __module_get(THIS_MODULE);
314
315 if (t->ops->prepare && t->ops->prepare(t))
316 goto out;
317
318 conn->last_active = jiffies;
319 set_freezable();
320 while (ksmbd_conn_alive(conn)) {
321 if (try_to_freeze())
322 continue;
323
324 kvfree(conn->request_buf);
325 conn->request_buf = NULL;
326
327 size = t->ops->read(t, hdr_buf, sizeof(hdr_buf), -1);
328 if (size != sizeof(hdr_buf))
329 break;
330
331 pdu_size = get_rfc1002_len(hdr_buf);
332 ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
333
334 if (ksmbd_conn_good(conn))
335 max_allowed_pdu_size =
336 SMB3_MAX_MSGSIZE + conn->vals->max_write_size;
337 else
338 max_allowed_pdu_size = SMB3_MAX_MSGSIZE;
339
340 if (pdu_size > max_allowed_pdu_size) {
341 pr_err_ratelimited("PDU length(%u) exceeded maximum allowed pdu size(%u) on connection(%d)\n",
342 pdu_size, max_allowed_pdu_size,
343 READ_ONCE(conn->status));
344 break;
345 }
346
347 /*
348 * Check maximum pdu size(0x00FFFFFF).
349 */
350 if (pdu_size > MAX_STREAM_PROT_LEN)
351 break;
352
353 if (pdu_size < SMB1_MIN_SUPPORTED_HEADER_SIZE)
354 break;
355
356 /* 4 for rfc1002 length field */
357 /* 1 for implied bcc[0] */
358 size = pdu_size + 4 + 1;
359 conn->request_buf = kvmalloc(size, GFP_KERNEL);
360 if (!conn->request_buf)
361 break;
362
363 memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
364
365 /*
366 * We already read 4 bytes to find out PDU size, now
367 * read in PDU
368 */
369 size = t->ops->read(t, conn->request_buf + 4, pdu_size, 2);
370 if (size < 0) {
371 pr_err("sock_read failed: %d\n", size);
372 break;
373 }
374
375 if (size != pdu_size) {
376 pr_err("PDU error. Read: %d, Expected: %d\n",
377 size, pdu_size);
378 continue;
379 }
380
381 if (!ksmbd_smb_request(conn))
382 break;
383
384 if (((struct smb2_hdr *)smb2_get_msg(conn->request_buf))->ProtocolId ==
385 SMB2_PROTO_NUMBER) {
386 if (pdu_size < SMB2_MIN_SUPPORTED_HEADER_SIZE)
387 break;
388 }
389
390 if (!default_conn_ops.process_fn) {
391 pr_err("No connection request callback\n");
392 break;
393 }
394
395 if (default_conn_ops.process_fn(conn)) {
396 pr_err("Cannot handle request\n");
397 break;
398 }
399 }
400
401 out:
402 ksmbd_conn_set_releasing(conn);
403 /* Wait till all reference dropped to the Server object*/
404 wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);
405
406 if (IS_ENABLED(CONFIG_UNICODE))
407 utf8_unload(conn->um);
408 unload_nls(conn->local_nls);
409 if (default_conn_ops.terminate_fn)
410 default_conn_ops.terminate_fn(conn);
411 t->ops->disconnect(t);
412 module_put(THIS_MODULE);
413 return 0;
414 }
415
ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops * ops)416 void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
417 {
418 default_conn_ops.process_fn = ops->process_fn;
419 default_conn_ops.terminate_fn = ops->terminate_fn;
420 }
421
ksmbd_conn_transport_init(void)422 int ksmbd_conn_transport_init(void)
423 {
424 int ret;
425
426 mutex_lock(&init_lock);
427 ret = ksmbd_tcp_init();
428 if (ret) {
429 pr_err("Failed to init TCP subsystem: %d\n", ret);
430 goto out;
431 }
432
433 ret = ksmbd_rdma_init();
434 if (ret) {
435 pr_err("Failed to init RDMA subsystem: %d\n", ret);
436 goto out;
437 }
438 out:
439 mutex_unlock(&init_lock);
440 return ret;
441 }
442
stop_sessions(void)443 static void stop_sessions(void)
444 {
445 struct ksmbd_conn *conn;
446 struct ksmbd_transport *t;
447
448 again:
449 down_read(&conn_list_lock);
450 list_for_each_entry(conn, &conn_list, conns_list) {
451 t = conn->transport;
452 ksmbd_conn_set_exiting(conn);
453 if (t->ops->shutdown) {
454 up_read(&conn_list_lock);
455 t->ops->shutdown(t);
456 down_read(&conn_list_lock);
457 }
458 }
459 up_read(&conn_list_lock);
460
461 if (!list_empty(&conn_list)) {
462 schedule_timeout_interruptible(HZ / 10); /* 100ms */
463 goto again;
464 }
465 }
466
ksmbd_conn_transport_destroy(void)467 void ksmbd_conn_transport_destroy(void)
468 {
469 mutex_lock(&init_lock);
470 ksmbd_tcp_destroy();
471 ksmbd_rdma_destroy();
472 stop_sessions();
473 mutex_unlock(&init_lock);
474 }
475