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 DEFINE_RWLOCK(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 write_lock(&conn_list_lock);
36 list_del(&conn->conns_list);
37 write_unlock(&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 conn->status = KSMBD_SESS_NEW;
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 write_lock(&conn_list_lock);
88 list_add(&conn->conns_list, &conn_list);
89 write_unlock(&conn_list_lock);
90 return conn;
91 }
92
ksmbd_conn_lookup_dialect(struct ksmbd_conn * c)93 bool ksmbd_conn_lookup_dialect(struct ksmbd_conn *c)
94 {
95 struct ksmbd_conn *t;
96 bool ret = false;
97
98 read_lock(&conn_list_lock);
99 list_for_each_entry(t, &conn_list, conns_list) {
100 if (memcmp(t->ClientGUID, c->ClientGUID, SMB2_CLIENT_GUID_SIZE))
101 continue;
102
103 ret = true;
104 break;
105 }
106 read_unlock(&conn_list_lock);
107 return ret;
108 }
109
ksmbd_conn_enqueue_request(struct ksmbd_work * work)110 void ksmbd_conn_enqueue_request(struct ksmbd_work *work)
111 {
112 struct ksmbd_conn *conn = work->conn;
113 struct list_head *requests_queue = NULL;
114
115 if (conn->ops->get_cmd_val(work) != SMB2_CANCEL_HE) {
116 requests_queue = &conn->requests;
117 work->syncronous = true;
118 }
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 int ksmbd_conn_try_dequeue_request(struct ksmbd_work *work)
129 {
130 struct ksmbd_conn *conn = work->conn;
131 int ret = 1;
132
133 if (list_empty(&work->request_entry) &&
134 list_empty(&work->async_request_entry))
135 return 0;
136
137 if (!work->multiRsp)
138 atomic_dec(&conn->req_running);
139 spin_lock(&conn->request_lock);
140 if (!work->multiRsp) {
141 list_del_init(&work->request_entry);
142 if (work->syncronous == false)
143 list_del_init(&work->async_request_entry);
144 ret = 0;
145 }
146 spin_unlock(&conn->request_lock);
147
148 wake_up_all(&conn->req_running_q);
149 return ret;
150 }
151
ksmbd_conn_lock(struct ksmbd_conn * conn)152 static void ksmbd_conn_lock(struct ksmbd_conn *conn)
153 {
154 mutex_lock(&conn->srv_mutex);
155 }
156
ksmbd_conn_unlock(struct ksmbd_conn * conn)157 static void ksmbd_conn_unlock(struct ksmbd_conn *conn)
158 {
159 mutex_unlock(&conn->srv_mutex);
160 }
161
ksmbd_conn_wait_idle(struct ksmbd_conn * conn)162 void ksmbd_conn_wait_idle(struct ksmbd_conn *conn)
163 {
164 wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
165 }
166
ksmbd_conn_write(struct ksmbd_work * work)167 int ksmbd_conn_write(struct ksmbd_work *work)
168 {
169 struct ksmbd_conn *conn = work->conn;
170 size_t len = 0;
171 int sent;
172 struct kvec iov[3];
173 int iov_idx = 0;
174
175 if (!work->response_buf) {
176 pr_err("NULL response header\n");
177 return -EINVAL;
178 }
179
180 if (work->tr_buf) {
181 iov[iov_idx] = (struct kvec) { work->tr_buf,
182 sizeof(struct smb2_transform_hdr) + 4 };
183 len += iov[iov_idx++].iov_len;
184 }
185
186 if (work->aux_payload_sz) {
187 iov[iov_idx] = (struct kvec) { work->response_buf, work->resp_hdr_sz };
188 len += iov[iov_idx++].iov_len;
189 iov[iov_idx] = (struct kvec) { work->aux_payload_buf, work->aux_payload_sz };
190 len += iov[iov_idx++].iov_len;
191 } else {
192 if (work->tr_buf)
193 iov[iov_idx].iov_len = work->resp_hdr_sz;
194 else
195 iov[iov_idx].iov_len = get_rfc1002_len(work->response_buf) + 4;
196 iov[iov_idx].iov_base = work->response_buf;
197 len += iov[iov_idx++].iov_len;
198 }
199
200 ksmbd_conn_lock(conn);
201 sent = conn->transport->ops->writev(conn->transport, &iov[0],
202 iov_idx, len,
203 work->need_invalidate_rkey,
204 work->remote_key);
205 ksmbd_conn_unlock(conn);
206
207 if (sent < 0) {
208 pr_err("Failed to send message: %d\n", sent);
209 return sent;
210 }
211
212 return 0;
213 }
214
ksmbd_conn_rdma_read(struct ksmbd_conn * conn,void * buf,unsigned int buflen,struct smb2_buffer_desc_v1 * desc,unsigned int desc_len)215 int ksmbd_conn_rdma_read(struct ksmbd_conn *conn,
216 void *buf, unsigned int buflen,
217 struct smb2_buffer_desc_v1 *desc,
218 unsigned int desc_len)
219 {
220 int ret = -EINVAL;
221
222 if (conn->transport->ops->rdma_read)
223 ret = conn->transport->ops->rdma_read(conn->transport,
224 buf, buflen,
225 desc, desc_len);
226 return ret;
227 }
228
ksmbd_conn_rdma_write(struct ksmbd_conn * conn,void * buf,unsigned int buflen,struct smb2_buffer_desc_v1 * desc,unsigned int desc_len)229 int ksmbd_conn_rdma_write(struct ksmbd_conn *conn,
230 void *buf, unsigned int buflen,
231 struct smb2_buffer_desc_v1 *desc,
232 unsigned int desc_len)
233 {
234 int ret = -EINVAL;
235
236 if (conn->transport->ops->rdma_write)
237 ret = conn->transport->ops->rdma_write(conn->transport,
238 buf, buflen,
239 desc, desc_len);
240 return ret;
241 }
242
ksmbd_conn_alive(struct ksmbd_conn * conn)243 bool ksmbd_conn_alive(struct ksmbd_conn *conn)
244 {
245 if (!ksmbd_server_running())
246 return false;
247
248 if (conn->status == KSMBD_SESS_EXITING)
249 return false;
250
251 if (kthread_should_stop())
252 return false;
253
254 if (atomic_read(&conn->stats.open_files_count) > 0)
255 return true;
256
257 /*
258 * Stop current session if the time that get last request from client
259 * is bigger than deadtime user configured and opening file count is
260 * zero.
261 */
262 if (server_conf.deadtime > 0 &&
263 time_after(jiffies, conn->last_active + server_conf.deadtime)) {
264 ksmbd_debug(CONN, "No response from client in %lu minutes\n",
265 server_conf.deadtime / SMB_ECHO_INTERVAL);
266 return false;
267 }
268 return true;
269 }
270
271 /**
272 * ksmbd_conn_handler_loop() - session thread to listen on new smb requests
273 * @p: connection instance
274 *
275 * One thread each per connection
276 *
277 * Return: 0 on success
278 */
ksmbd_conn_handler_loop(void * p)279 int ksmbd_conn_handler_loop(void *p)
280 {
281 struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
282 struct ksmbd_transport *t = conn->transport;
283 unsigned int pdu_size, max_allowed_pdu_size;
284 char hdr_buf[4] = {0,};
285 int size;
286
287 mutex_init(&conn->srv_mutex);
288 __module_get(THIS_MODULE);
289
290 if (t->ops->prepare && t->ops->prepare(t))
291 goto out;
292
293 conn->last_active = jiffies;
294 while (ksmbd_conn_alive(conn)) {
295 if (try_to_freeze())
296 continue;
297
298 kvfree(conn->request_buf);
299 conn->request_buf = NULL;
300
301 size = t->ops->read(t, hdr_buf, sizeof(hdr_buf));
302 if (size != sizeof(hdr_buf))
303 break;
304
305 pdu_size = get_rfc1002_len(hdr_buf);
306 ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
307
308 if (conn->status == KSMBD_SESS_GOOD)
309 max_allowed_pdu_size =
310 SMB3_MAX_MSGSIZE + conn->vals->max_write_size;
311 else
312 max_allowed_pdu_size = SMB3_MAX_MSGSIZE;
313
314 if (pdu_size > max_allowed_pdu_size) {
315 pr_err_ratelimited("PDU length(%u) excceed maximum allowed pdu size(%u) on connection(%d)\n",
316 pdu_size, max_allowed_pdu_size,
317 conn->status);
318 break;
319 }
320
321 /*
322 * Check if pdu size is valid (min : smb header size,
323 * max : 0x00FFFFFF).
324 */
325 if (pdu_size < __SMB2_HEADER_STRUCTURE_SIZE ||
326 pdu_size > MAX_STREAM_PROT_LEN) {
327 break;
328 }
329
330 /* 4 for rfc1002 length field */
331 size = pdu_size + 4;
332 conn->request_buf = kvmalloc(size,
333 GFP_KERNEL |
334 __GFP_NOWARN |
335 __GFP_NORETRY);
336 if (!conn->request_buf)
337 break;
338
339 memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
340 if (!ksmbd_smb_request(conn))
341 break;
342
343 /*
344 * We already read 4 bytes to find out PDU size, now
345 * read in PDU
346 */
347 size = t->ops->read(t, conn->request_buf + 4, pdu_size);
348 if (size < 0) {
349 pr_err("sock_read failed: %d\n", size);
350 break;
351 }
352
353 if (size != pdu_size) {
354 pr_err("PDU error. Read: %d, Expected: %d\n",
355 size, pdu_size);
356 continue;
357 }
358
359 if (!default_conn_ops.process_fn) {
360 pr_err("No connection request callback\n");
361 break;
362 }
363
364 if (default_conn_ops.process_fn(conn)) {
365 pr_err("Cannot handle request\n");
366 break;
367 }
368 }
369
370 out:
371 /* Wait till all reference dropped to the Server object*/
372 wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);
373
374
375 if (IS_ENABLED(CONFIG_UNICODE))
376 utf8_unload(conn->um);
377 unload_nls(conn->local_nls);
378 if (default_conn_ops.terminate_fn)
379 default_conn_ops.terminate_fn(conn);
380 t->ops->disconnect(t);
381 module_put(THIS_MODULE);
382 return 0;
383 }
384
ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops * ops)385 void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
386 {
387 default_conn_ops.process_fn = ops->process_fn;
388 default_conn_ops.terminate_fn = ops->terminate_fn;
389 }
390
ksmbd_conn_transport_init(void)391 int ksmbd_conn_transport_init(void)
392 {
393 int ret;
394
395 mutex_lock(&init_lock);
396 ret = ksmbd_tcp_init();
397 if (ret) {
398 pr_err("Failed to init TCP subsystem: %d\n", ret);
399 goto out;
400 }
401
402 ret = ksmbd_rdma_init();
403 if (ret) {
404 pr_err("Failed to init RDMA subsystem: %d\n", ret);
405 goto out;
406 }
407 out:
408 mutex_unlock(&init_lock);
409 return ret;
410 }
411
stop_sessions(void)412 static void stop_sessions(void)
413 {
414 struct ksmbd_conn *conn;
415 struct ksmbd_transport *t;
416
417 again:
418 read_lock(&conn_list_lock);
419 list_for_each_entry(conn, &conn_list, conns_list) {
420 struct task_struct *task;
421
422 t = conn->transport;
423 task = t->handler;
424 if (task)
425 ksmbd_debug(CONN, "Stop session handler %s/%d\n",
426 task->comm, task_pid_nr(task));
427 conn->status = KSMBD_SESS_EXITING;
428 if (t->ops->shutdown) {
429 read_unlock(&conn_list_lock);
430 t->ops->shutdown(t);
431 read_lock(&conn_list_lock);
432 }
433 }
434 read_unlock(&conn_list_lock);
435
436 if (!list_empty(&conn_list)) {
437 schedule_timeout_interruptible(HZ / 10); /* 100ms */
438 goto again;
439 }
440 }
441
ksmbd_conn_transport_destroy(void)442 void ksmbd_conn_transport_destroy(void)
443 {
444 mutex_lock(&init_lock);
445 ksmbd_tcp_destroy();
446 ksmbd_rdma_destroy();
447 stop_sessions();
448 mutex_unlock(&init_lock);
449 }
450