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 cleaned 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 if (atomic_dec_and_test(&conn->refcnt))
43 kfree(conn);
44 }
45
46 /**
47 * ksmbd_conn_alloc() - initialize a new connection instance
48 *
49 * Return: ksmbd_conn struct on success, otherwise NULL
50 */
ksmbd_conn_alloc(void)51 struct ksmbd_conn *ksmbd_conn_alloc(void)
52 {
53 struct ksmbd_conn *conn;
54
55 conn = kzalloc(sizeof(struct ksmbd_conn), GFP_KERNEL);
56 if (!conn)
57 return NULL;
58
59 conn->need_neg = true;
60 ksmbd_conn_set_new(conn);
61 conn->local_nls = load_nls("utf8");
62 if (!conn->local_nls)
63 conn->local_nls = load_nls_default();
64 if (IS_ENABLED(CONFIG_UNICODE))
65 conn->um = utf8_load(UNICODE_AGE(12, 1, 0));
66 else
67 conn->um = ERR_PTR(-EOPNOTSUPP);
68 if (IS_ERR(conn->um))
69 conn->um = NULL;
70 atomic_set(&conn->req_running, 0);
71 atomic_set(&conn->r_count, 0);
72 atomic_set(&conn->refcnt, 1);
73 atomic_set(&conn->mux_smb_requests, 0);
74 conn->total_credits = 1;
75 conn->outstanding_credits = 0;
76
77 init_waitqueue_head(&conn->req_running_q);
78 init_waitqueue_head(&conn->r_count_q);
79 INIT_LIST_HEAD(&conn->conns_list);
80 INIT_LIST_HEAD(&conn->requests);
81 INIT_LIST_HEAD(&conn->async_requests);
82 spin_lock_init(&conn->request_lock);
83 spin_lock_init(&conn->credits_lock);
84 ida_init(&conn->async_ida);
85 xa_init(&conn->sessions);
86
87 spin_lock_init(&conn->llist_lock);
88 INIT_LIST_HEAD(&conn->lock_list);
89
90 init_rwsem(&conn->session_lock);
91
92 down_write(&conn_list_lock);
93 list_add(&conn->conns_list, &conn_list);
94 up_write(&conn_list_lock);
95 return conn;
96 }
97
ksmbd_conn_lookup_dialect(struct ksmbd_conn * c)98 bool ksmbd_conn_lookup_dialect(struct ksmbd_conn *c)
99 {
100 struct ksmbd_conn *t;
101 bool ret = false;
102
103 down_read(&conn_list_lock);
104 list_for_each_entry(t, &conn_list, conns_list) {
105 if (memcmp(t->ClientGUID, c->ClientGUID, SMB2_CLIENT_GUID_SIZE))
106 continue;
107
108 ret = true;
109 break;
110 }
111 up_read(&conn_list_lock);
112 return ret;
113 }
114
ksmbd_conn_enqueue_request(struct ksmbd_work * work)115 void ksmbd_conn_enqueue_request(struct ksmbd_work *work)
116 {
117 struct ksmbd_conn *conn = work->conn;
118 struct list_head *requests_queue = NULL;
119
120 if (conn->ops->get_cmd_val(work) != SMB2_CANCEL_HE)
121 requests_queue = &conn->requests;
122
123 if (requests_queue) {
124 atomic_inc(&conn->req_running);
125 spin_lock(&conn->request_lock);
126 list_add_tail(&work->request_entry, requests_queue);
127 spin_unlock(&conn->request_lock);
128 }
129 }
130
ksmbd_conn_try_dequeue_request(struct ksmbd_work * work)131 void ksmbd_conn_try_dequeue_request(struct ksmbd_work *work)
132 {
133 struct ksmbd_conn *conn = work->conn;
134
135 if (list_empty(&work->request_entry) &&
136 list_empty(&work->async_request_entry))
137 return;
138
139 atomic_dec(&conn->req_running);
140 spin_lock(&conn->request_lock);
141 list_del_init(&work->request_entry);
142 spin_unlock(&conn->request_lock);
143 if (work->asynchronous)
144 release_async_work(work);
145
146 wake_up_all(&conn->req_running_q);
147 }
148
ksmbd_conn_lock(struct ksmbd_conn * conn)149 void ksmbd_conn_lock(struct ksmbd_conn *conn)
150 {
151 mutex_lock(&conn->srv_mutex);
152 }
153
ksmbd_conn_unlock(struct ksmbd_conn * conn)154 void ksmbd_conn_unlock(struct ksmbd_conn *conn)
155 {
156 mutex_unlock(&conn->srv_mutex);
157 }
158
ksmbd_all_conn_set_status(u64 sess_id,u32 status)159 void ksmbd_all_conn_set_status(u64 sess_id, u32 status)
160 {
161 struct ksmbd_conn *conn;
162
163 down_read(&conn_list_lock);
164 list_for_each_entry(conn, &conn_list, conns_list) {
165 if (conn->binding || xa_load(&conn->sessions, sess_id))
166 WRITE_ONCE(conn->status, status);
167 }
168 up_read(&conn_list_lock);
169 }
170
ksmbd_conn_wait_idle(struct ksmbd_conn * conn)171 void ksmbd_conn_wait_idle(struct ksmbd_conn *conn)
172 {
173 wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
174 }
175
ksmbd_conn_wait_idle_sess_id(struct ksmbd_conn * curr_conn,u64 sess_id)176 int ksmbd_conn_wait_idle_sess_id(struct ksmbd_conn *curr_conn, u64 sess_id)
177 {
178 struct ksmbd_conn *conn;
179 int rc, retry_count = 0, max_timeout = 120;
180 int rcount = 1;
181
182 retry_idle:
183 if (retry_count >= max_timeout)
184 return -EIO;
185
186 down_read(&conn_list_lock);
187 list_for_each_entry(conn, &conn_list, conns_list) {
188 if (conn->binding || xa_load(&conn->sessions, sess_id)) {
189 if (conn == curr_conn)
190 rcount = 2;
191 if (atomic_read(&conn->req_running) >= rcount) {
192 rc = wait_event_timeout(conn->req_running_q,
193 atomic_read(&conn->req_running) < rcount,
194 HZ);
195 if (!rc) {
196 up_read(&conn_list_lock);
197 retry_count++;
198 goto retry_idle;
199 }
200 }
201 }
202 }
203 up_read(&conn_list_lock);
204
205 return 0;
206 }
207
ksmbd_conn_write(struct ksmbd_work * work)208 int ksmbd_conn_write(struct ksmbd_work *work)
209 {
210 struct ksmbd_conn *conn = work->conn;
211 int sent;
212
213 if (!work->response_buf) {
214 pr_err("NULL response header\n");
215 return -EINVAL;
216 }
217
218 if (work->send_no_response)
219 return 0;
220
221 if (!work->iov_idx)
222 return -EINVAL;
223
224 ksmbd_conn_lock(conn);
225 sent = conn->transport->ops->writev(conn->transport, work->iov,
226 work->iov_cnt,
227 get_rfc1002_len(work->iov[0].iov_base) + 4,
228 work->need_invalidate_rkey,
229 work->remote_key);
230 ksmbd_conn_unlock(conn);
231
232 if (sent < 0) {
233 pr_err("Failed to send message: %d\n", sent);
234 return sent;
235 }
236
237 return 0;
238 }
239
ksmbd_conn_rdma_read(struct ksmbd_conn * conn,void * buf,unsigned int buflen,struct smb2_buffer_desc_v1 * desc,unsigned int desc_len)240 int ksmbd_conn_rdma_read(struct ksmbd_conn *conn,
241 void *buf, unsigned int buflen,
242 struct smb2_buffer_desc_v1 *desc,
243 unsigned int desc_len)
244 {
245 int ret = -EINVAL;
246
247 if (conn->transport->ops->rdma_read)
248 ret = conn->transport->ops->rdma_read(conn->transport,
249 buf, buflen,
250 desc, desc_len);
251 return ret;
252 }
253
ksmbd_conn_rdma_write(struct ksmbd_conn * conn,void * buf,unsigned int buflen,struct smb2_buffer_desc_v1 * desc,unsigned int desc_len)254 int ksmbd_conn_rdma_write(struct ksmbd_conn *conn,
255 void *buf, unsigned int buflen,
256 struct smb2_buffer_desc_v1 *desc,
257 unsigned int desc_len)
258 {
259 int ret = -EINVAL;
260
261 if (conn->transport->ops->rdma_write)
262 ret = conn->transport->ops->rdma_write(conn->transport,
263 buf, buflen,
264 desc, desc_len);
265 return ret;
266 }
267
ksmbd_conn_alive(struct ksmbd_conn * conn)268 bool ksmbd_conn_alive(struct ksmbd_conn *conn)
269 {
270 if (!ksmbd_server_running())
271 return false;
272
273 if (ksmbd_conn_exiting(conn))
274 return false;
275
276 if (kthread_should_stop())
277 return false;
278
279 if (atomic_read(&conn->stats.open_files_count) > 0)
280 return true;
281
282 /*
283 * Stop current session if the time that get last request from client
284 * is bigger than deadtime user configured and opening file count is
285 * zero.
286 */
287 if (server_conf.deadtime > 0 &&
288 time_after(jiffies, conn->last_active + server_conf.deadtime)) {
289 ksmbd_debug(CONN, "No response from client in %lu minutes\n",
290 server_conf.deadtime / SMB_ECHO_INTERVAL);
291 return false;
292 }
293 return true;
294 }
295
296 #define SMB1_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb_hdr))
297 #define SMB2_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb2_hdr) + 4)
298
299 /**
300 * ksmbd_conn_handler_loop() - session thread to listen on new smb requests
301 * @p: connection instance
302 *
303 * One thread each per connection
304 *
305 * Return: 0 on success
306 */
ksmbd_conn_handler_loop(void * p)307 int ksmbd_conn_handler_loop(void *p)
308 {
309 struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
310 struct ksmbd_transport *t = conn->transport;
311 unsigned int pdu_size, max_allowed_pdu_size;
312 char hdr_buf[4] = {0,};
313 int size;
314
315 mutex_init(&conn->srv_mutex);
316 __module_get(THIS_MODULE);
317
318 if (t->ops->prepare && t->ops->prepare(t))
319 goto out;
320
321 conn->last_active = jiffies;
322 set_freezable();
323 while (ksmbd_conn_alive(conn)) {
324 if (try_to_freeze())
325 continue;
326
327 kvfree(conn->request_buf);
328 conn->request_buf = NULL;
329
330 size = t->ops->read(t, hdr_buf, sizeof(hdr_buf), -1);
331 if (size != sizeof(hdr_buf))
332 break;
333
334 pdu_size = get_rfc1002_len(hdr_buf);
335 ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
336
337 if (ksmbd_conn_good(conn))
338 max_allowed_pdu_size =
339 SMB3_MAX_MSGSIZE + conn->vals->max_write_size;
340 else
341 max_allowed_pdu_size = SMB3_MAX_MSGSIZE;
342
343 if (pdu_size > max_allowed_pdu_size) {
344 pr_err_ratelimited("PDU length(%u) exceeded maximum allowed pdu size(%u) on connection(%d)\n",
345 pdu_size, max_allowed_pdu_size,
346 READ_ONCE(conn->status));
347 break;
348 }
349
350 /*
351 * Check maximum pdu size(0x00FFFFFF).
352 */
353 if (pdu_size > MAX_STREAM_PROT_LEN)
354 break;
355
356 if (pdu_size < SMB1_MIN_SUPPORTED_HEADER_SIZE)
357 break;
358
359 /* 4 for rfc1002 length field */
360 /* 1 for implied bcc[0] */
361 size = pdu_size + 4 + 1;
362 conn->request_buf = kvmalloc(size, GFP_KERNEL);
363 if (!conn->request_buf)
364 break;
365
366 memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
367
368 /*
369 * We already read 4 bytes to find out PDU size, now
370 * read in PDU
371 */
372 size = t->ops->read(t, conn->request_buf + 4, pdu_size, 2);
373 if (size < 0) {
374 pr_err("sock_read failed: %d\n", size);
375 break;
376 }
377
378 if (size != pdu_size) {
379 pr_err("PDU error. Read: %d, Expected: %d\n",
380 size, pdu_size);
381 continue;
382 }
383
384 if (!ksmbd_smb_request(conn))
385 break;
386
387 if (((struct smb2_hdr *)smb2_get_msg(conn->request_buf))->ProtocolId ==
388 SMB2_PROTO_NUMBER) {
389 if (pdu_size < SMB2_MIN_SUPPORTED_HEADER_SIZE)
390 break;
391 }
392
393 if (!default_conn_ops.process_fn) {
394 pr_err("No connection request callback\n");
395 break;
396 }
397
398 if (default_conn_ops.process_fn(conn)) {
399 pr_err("Cannot handle request\n");
400 break;
401 }
402 }
403
404 out:
405 ksmbd_conn_set_releasing(conn);
406 /* Wait till all reference dropped to the Server object*/
407 wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);
408
409 if (IS_ENABLED(CONFIG_UNICODE))
410 utf8_unload(conn->um);
411 unload_nls(conn->local_nls);
412 if (default_conn_ops.terminate_fn)
413 default_conn_ops.terminate_fn(conn);
414 t->ops->disconnect(t);
415 module_put(THIS_MODULE);
416 return 0;
417 }
418
ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops * ops)419 void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
420 {
421 default_conn_ops.process_fn = ops->process_fn;
422 default_conn_ops.terminate_fn = ops->terminate_fn;
423 }
424
ksmbd_conn_transport_init(void)425 int ksmbd_conn_transport_init(void)
426 {
427 int ret;
428
429 mutex_lock(&init_lock);
430 ret = ksmbd_tcp_init();
431 if (ret) {
432 pr_err("Failed to init TCP subsystem: %d\n", ret);
433 goto out;
434 }
435
436 ret = ksmbd_rdma_init();
437 if (ret) {
438 pr_err("Failed to init RDMA subsystem: %d\n", ret);
439 goto out;
440 }
441 out:
442 mutex_unlock(&init_lock);
443 return ret;
444 }
445
stop_sessions(void)446 static void stop_sessions(void)
447 {
448 struct ksmbd_conn *conn;
449 struct ksmbd_transport *t;
450
451 again:
452 down_read(&conn_list_lock);
453 list_for_each_entry(conn, &conn_list, conns_list) {
454 t = conn->transport;
455 ksmbd_conn_set_exiting(conn);
456 if (t->ops->shutdown) {
457 up_read(&conn_list_lock);
458 t->ops->shutdown(t);
459 down_read(&conn_list_lock);
460 }
461 }
462 up_read(&conn_list_lock);
463
464 if (!list_empty(&conn_list)) {
465 schedule_timeout_interruptible(HZ / 10); /* 100ms */
466 goto again;
467 }
468 }
469
ksmbd_conn_transport_destroy(void)470 void ksmbd_conn_transport_destroy(void)
471 {
472 mutex_lock(&init_lock);
473 ksmbd_tcp_destroy();
474 ksmbd_rdma_destroy();
475 stop_sessions();
476 mutex_unlock(&init_lock);
477 }
478