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