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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
18static DEFINE_MUTEX(init_lock);
19
20static struct ksmbd_conn_ops default_conn_ops;
21
22LIST_HEAD(conn_list);
23DECLARE_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 */
33void 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 */
51struct ksmbd_conn *ksmbd_conn_alloc(void)
52{
53 struct ksmbd_conn *conn;
54
55 conn = kzalloc(sizeof(struct ksmbd_conn), KSMBD_DEFAULT_GFP);
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
97bool 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
114void 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 atomic_inc(&conn->req_running);
123 if (requests_queue) {
124 spin_lock(&conn->request_lock);
125 list_add_tail(&work->request_entry, requests_queue);
126 spin_unlock(&conn->request_lock);
127 }
128}
129
130void ksmbd_conn_try_dequeue_request(struct ksmbd_work *work)
131{
132 struct ksmbd_conn *conn = work->conn;
133
134 atomic_dec(&conn->req_running);
135 if (waitqueue_active(&conn->req_running_q))
136 wake_up(&conn->req_running_q);
137
138 if (list_empty(&work->request_entry) &&
139 list_empty(&work->async_request_entry))
140 return;
141
142 spin_lock(&conn->request_lock);
143 list_del_init(&work->request_entry);
144 spin_unlock(&conn->request_lock);
145 if (work->asynchronous)
146 release_async_work(work);
147
148 wake_up_all(&conn->req_running_q);
149}
150
151void ksmbd_conn_lock(struct ksmbd_conn *conn)
152{
153 mutex_lock(&conn->srv_mutex);
154}
155
156void ksmbd_conn_unlock(struct ksmbd_conn *conn)
157{
158 mutex_unlock(&conn->srv_mutex);
159}
160
161void ksmbd_all_conn_set_status(u64 sess_id, u32 status)
162{
163 struct ksmbd_conn *conn;
164
165 down_read(&conn_list_lock);
166 list_for_each_entry(conn, &conn_list, conns_list) {
167 if (conn->binding || xa_load(&conn->sessions, sess_id))
168 WRITE_ONCE(conn->status, status);
169 }
170 up_read(&conn_list_lock);
171}
172
173void ksmbd_conn_wait_idle(struct ksmbd_conn *conn)
174{
175 wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
176}
177
178int ksmbd_conn_wait_idle_sess_id(struct ksmbd_conn *curr_conn, u64 sess_id)
179{
180 struct ksmbd_conn *conn;
181 int rc, retry_count = 0, max_timeout = 120;
182 int rcount = 1;
183
184retry_idle:
185 if (retry_count >= max_timeout)
186 return -EIO;
187
188 down_read(&conn_list_lock);
189 list_for_each_entry(conn, &conn_list, conns_list) {
190 if (conn->binding || xa_load(&conn->sessions, sess_id)) {
191 if (conn == curr_conn)
192 rcount = 2;
193 if (atomic_read(&conn->req_running) >= rcount) {
194 rc = wait_event_timeout(conn->req_running_q,
195 atomic_read(&conn->req_running) < rcount,
196 HZ);
197 if (!rc) {
198 up_read(&conn_list_lock);
199 retry_count++;
200 goto retry_idle;
201 }
202 }
203 }
204 }
205 up_read(&conn_list_lock);
206
207 return 0;
208}
209
210int ksmbd_conn_write(struct ksmbd_work *work)
211{
212 struct ksmbd_conn *conn = work->conn;
213 int sent;
214
215 if (!work->response_buf) {
216 pr_err("NULL response header\n");
217 return -EINVAL;
218 }
219
220 if (work->send_no_response)
221 return 0;
222
223 if (!work->iov_idx)
224 return -EINVAL;
225
226 ksmbd_conn_lock(conn);
227 sent = conn->transport->ops->writev(conn->transport, work->iov,
228 work->iov_cnt,
229 get_rfc1002_len(work->iov[0].iov_base) + 4,
230 work->need_invalidate_rkey,
231 work->remote_key);
232 ksmbd_conn_unlock(conn);
233
234 if (sent < 0) {
235 pr_err("Failed to send message: %d\n", sent);
236 return sent;
237 }
238
239 return 0;
240}
241
242int ksmbd_conn_rdma_read(struct ksmbd_conn *conn,
243 void *buf, unsigned int buflen,
244 struct smb2_buffer_desc_v1 *desc,
245 unsigned int desc_len)
246{
247 int ret = -EINVAL;
248
249 if (conn->transport->ops->rdma_read)
250 ret = conn->transport->ops->rdma_read(conn->transport,
251 buf, buflen,
252 desc, desc_len);
253 return ret;
254}
255
256int ksmbd_conn_rdma_write(struct ksmbd_conn *conn,
257 void *buf, unsigned int buflen,
258 struct smb2_buffer_desc_v1 *desc,
259 unsigned int desc_len)
260{
261 int ret = -EINVAL;
262
263 if (conn->transport->ops->rdma_write)
264 ret = conn->transport->ops->rdma_write(conn->transport,
265 buf, buflen,
266 desc, desc_len);
267 return ret;
268}
269
270bool ksmbd_conn_alive(struct ksmbd_conn *conn)
271{
272 if (!ksmbd_server_running())
273 return false;
274
275 if (ksmbd_conn_exiting(conn))
276 return false;
277
278 if (kthread_should_stop())
279 return false;
280
281 if (atomic_read(&conn->stats.open_files_count) > 0)
282 return true;
283
284 /*
285 * Stop current session if the time that get last request from client
286 * is bigger than deadtime user configured and opening file count is
287 * zero.
288 */
289 if (server_conf.deadtime > 0 &&
290 time_after(jiffies, conn->last_active + server_conf.deadtime)) {
291 ksmbd_debug(CONN, "No response from client in %lu minutes\n",
292 server_conf.deadtime / SMB_ECHO_INTERVAL);
293 return false;
294 }
295 return true;
296}
297
298#define SMB1_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb_hdr))
299#define SMB2_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb2_hdr) + 4)
300
301/**
302 * ksmbd_conn_handler_loop() - session thread to listen on new smb requests
303 * @p: connection instance
304 *
305 * One thread each per connection
306 *
307 * Return: 0 on success
308 */
309int ksmbd_conn_handler_loop(void *p)
310{
311 struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
312 struct ksmbd_transport *t = conn->transport;
313 unsigned int pdu_size, max_allowed_pdu_size, max_req;
314 char hdr_buf[4] = {0,};
315 int size;
316
317 mutex_init(&conn->srv_mutex);
318 __module_get(THIS_MODULE);
319
320 if (t->ops->prepare && t->ops->prepare(t))
321 goto out;
322
323 max_req = server_conf.max_inflight_req;
324 conn->last_active = jiffies;
325 set_freezable();
326 while (ksmbd_conn_alive(conn)) {
327 if (try_to_freeze())
328 continue;
329
330 kvfree(conn->request_buf);
331 conn->request_buf = NULL;
332
333recheck:
334 if (atomic_read(&conn->req_running) + 1 > max_req) {
335 wait_event_interruptible(conn->req_running_q,
336 atomic_read(&conn->req_running) < max_req);
337 goto recheck;
338 }
339
340 size = t->ops->read(t, hdr_buf, sizeof(hdr_buf), -1);
341 if (size != sizeof(hdr_buf))
342 break;
343
344 pdu_size = get_rfc1002_len(hdr_buf);
345 ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
346
347 if (ksmbd_conn_good(conn))
348 max_allowed_pdu_size =
349 SMB3_MAX_MSGSIZE + conn->vals->max_write_size;
350 else
351 max_allowed_pdu_size = SMB3_MAX_MSGSIZE;
352
353 if (pdu_size > max_allowed_pdu_size) {
354 pr_err_ratelimited("PDU length(%u) exceeded maximum allowed pdu size(%u) on connection(%d)\n",
355 pdu_size, max_allowed_pdu_size,
356 READ_ONCE(conn->status));
357 break;
358 }
359
360 /*
361 * Check maximum pdu size(0x00FFFFFF).
362 */
363 if (pdu_size > MAX_STREAM_PROT_LEN)
364 break;
365
366 if (pdu_size < SMB1_MIN_SUPPORTED_HEADER_SIZE)
367 break;
368
369 /* 4 for rfc1002 length field */
370 /* 1 for implied bcc[0] */
371 size = pdu_size + 4 + 1;
372 conn->request_buf = kvmalloc(size, KSMBD_DEFAULT_GFP);
373 if (!conn->request_buf)
374 break;
375
376 memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
377
378 /*
379 * We already read 4 bytes to find out PDU size, now
380 * read in PDU
381 */
382 size = t->ops->read(t, conn->request_buf + 4, pdu_size, 2);
383 if (size < 0) {
384 pr_err("sock_read failed: %d\n", size);
385 break;
386 }
387
388 if (size != pdu_size) {
389 pr_err("PDU error. Read: %d, Expected: %d\n",
390 size, pdu_size);
391 continue;
392 }
393
394 if (!ksmbd_smb_request(conn))
395 break;
396
397 if (((struct smb2_hdr *)smb2_get_msg(conn->request_buf))->ProtocolId ==
398 SMB2_PROTO_NUMBER) {
399 if (pdu_size < SMB2_MIN_SUPPORTED_HEADER_SIZE)
400 break;
401 }
402
403 if (!default_conn_ops.process_fn) {
404 pr_err("No connection request callback\n");
405 break;
406 }
407
408 if (default_conn_ops.process_fn(conn)) {
409 pr_err("Cannot handle request\n");
410 break;
411 }
412 }
413
414out:
415 ksmbd_conn_set_releasing(conn);
416 /* Wait till all reference dropped to the Server object*/
417 ksmbd_debug(CONN, "Wait for all pending requests(%d)\n", atomic_read(&conn->r_count));
418 wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);
419
420 if (IS_ENABLED(CONFIG_UNICODE))
421 utf8_unload(conn->um);
422 unload_nls(conn->local_nls);
423 if (default_conn_ops.terminate_fn)
424 default_conn_ops.terminate_fn(conn);
425 t->ops->disconnect(t);
426 module_put(THIS_MODULE);
427 return 0;
428}
429
430void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
431{
432 default_conn_ops.process_fn = ops->process_fn;
433 default_conn_ops.terminate_fn = ops->terminate_fn;
434}
435
436int ksmbd_conn_transport_init(void)
437{
438 int ret;
439
440 mutex_lock(&init_lock);
441 ret = ksmbd_tcp_init();
442 if (ret) {
443 pr_err("Failed to init TCP subsystem: %d\n", ret);
444 goto out;
445 }
446
447 ret = ksmbd_rdma_init();
448 if (ret) {
449 pr_err("Failed to init RDMA subsystem: %d\n", ret);
450 goto out;
451 }
452out:
453 mutex_unlock(&init_lock);
454 return ret;
455}
456
457static void stop_sessions(void)
458{
459 struct ksmbd_conn *conn;
460 struct ksmbd_transport *t;
461
462again:
463 down_read(&conn_list_lock);
464 list_for_each_entry(conn, &conn_list, conns_list) {
465 t = conn->transport;
466 ksmbd_conn_set_exiting(conn);
467 if (t->ops->shutdown) {
468 up_read(&conn_list_lock);
469 t->ops->shutdown(t);
470 down_read(&conn_list_lock);
471 }
472 }
473 up_read(&conn_list_lock);
474
475 if (!list_empty(&conn_list)) {
476 msleep(100);
477 goto again;
478 }
479}
480
481void ksmbd_conn_transport_destroy(void)
482{
483 mutex_lock(&init_lock);
484 ksmbd_tcp_destroy();
485 ksmbd_rdma_destroy();
486 stop_sessions();
487 mutex_unlock(&init_lock);
488}