ksmbd: Add missing set_freezable() for freezable kthread
[platform/kernel/linux-rpi.git] / fs / smb / server / connection.c
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  */
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  */
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
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
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
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
146 void ksmbd_conn_lock(struct ksmbd_conn *conn)
147 {
148         mutex_lock(&conn->srv_mutex);
149 }
150
151 void ksmbd_conn_unlock(struct ksmbd_conn *conn)
152 {
153         mutex_unlock(&conn->srv_mutex);
154 }
155
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
168 void ksmbd_conn_wait_idle(struct ksmbd_conn *conn, u64 sess_id)
169 {
170         wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
171 }
172
173 int ksmbd_conn_write(struct ksmbd_work *work)
174 {
175         struct ksmbd_conn *conn = work->conn;
176         int sent;
177
178         if (!work->response_buf) {
179                 pr_err("NULL response header\n");
180                 return -EINVAL;
181         }
182
183         if (work->send_no_response)
184                 return 0;
185
186         if (!work->iov_idx)
187                 return -EINVAL;
188
189         ksmbd_conn_lock(conn);
190         sent = conn->transport->ops->writev(conn->transport, work->iov,
191                         work->iov_cnt,
192                         get_rfc1002_len(work->iov[0].iov_base) + 4,
193                         work->need_invalidate_rkey,
194                         work->remote_key);
195         ksmbd_conn_unlock(conn);
196
197         if (sent < 0) {
198                 pr_err("Failed to send message: %d\n", sent);
199                 return sent;
200         }
201
202         return 0;
203 }
204
205 int ksmbd_conn_rdma_read(struct ksmbd_conn *conn,
206                          void *buf, unsigned int buflen,
207                          struct smb2_buffer_desc_v1 *desc,
208                          unsigned int desc_len)
209 {
210         int ret = -EINVAL;
211
212         if (conn->transport->ops->rdma_read)
213                 ret = conn->transport->ops->rdma_read(conn->transport,
214                                                       buf, buflen,
215                                                       desc, desc_len);
216         return ret;
217 }
218
219 int ksmbd_conn_rdma_write(struct ksmbd_conn *conn,
220                           void *buf, unsigned int buflen,
221                           struct smb2_buffer_desc_v1 *desc,
222                           unsigned int desc_len)
223 {
224         int ret = -EINVAL;
225
226         if (conn->transport->ops->rdma_write)
227                 ret = conn->transport->ops->rdma_write(conn->transport,
228                                                        buf, buflen,
229                                                        desc, desc_len);
230         return ret;
231 }
232
233 bool ksmbd_conn_alive(struct ksmbd_conn *conn)
234 {
235         if (!ksmbd_server_running())
236                 return false;
237
238         if (ksmbd_conn_exiting(conn))
239                 return false;
240
241         if (kthread_should_stop())
242                 return false;
243
244         if (atomic_read(&conn->stats.open_files_count) > 0)
245                 return true;
246
247         /*
248          * Stop current session if the time that get last request from client
249          * is bigger than deadtime user configured and opening file count is
250          * zero.
251          */
252         if (server_conf.deadtime > 0 &&
253             time_after(jiffies, conn->last_active + server_conf.deadtime)) {
254                 ksmbd_debug(CONN, "No response from client in %lu minutes\n",
255                             server_conf.deadtime / SMB_ECHO_INTERVAL);
256                 return false;
257         }
258         return true;
259 }
260
261 #define SMB1_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb_hdr))
262 #define SMB2_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb2_hdr) + 4)
263
264 /**
265  * ksmbd_conn_handler_loop() - session thread to listen on new smb requests
266  * @p:          connection instance
267  *
268  * One thread each per connection
269  *
270  * Return:      0 on success
271  */
272 int ksmbd_conn_handler_loop(void *p)
273 {
274         struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
275         struct ksmbd_transport *t = conn->transport;
276         unsigned int pdu_size, max_allowed_pdu_size;
277         char hdr_buf[4] = {0,};
278         int size;
279
280         mutex_init(&conn->srv_mutex);
281         __module_get(THIS_MODULE);
282
283         if (t->ops->prepare && t->ops->prepare(t))
284                 goto out;
285
286         conn->last_active = jiffies;
287         set_freezable();
288         while (ksmbd_conn_alive(conn)) {
289                 if (try_to_freeze())
290                         continue;
291
292                 kvfree(conn->request_buf);
293                 conn->request_buf = NULL;
294
295                 size = t->ops->read(t, hdr_buf, sizeof(hdr_buf), -1);
296                 if (size != sizeof(hdr_buf))
297                         break;
298
299                 pdu_size = get_rfc1002_len(hdr_buf);
300                 ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
301
302                 if (ksmbd_conn_good(conn))
303                         max_allowed_pdu_size =
304                                 SMB3_MAX_MSGSIZE + conn->vals->max_write_size;
305                 else
306                         max_allowed_pdu_size = SMB3_MAX_MSGSIZE;
307
308                 if (pdu_size > max_allowed_pdu_size) {
309                         pr_err_ratelimited("PDU length(%u) exceeded maximum allowed pdu size(%u) on connection(%d)\n",
310                                         pdu_size, max_allowed_pdu_size,
311                                         READ_ONCE(conn->status));
312                         break;
313                 }
314
315                 /*
316                  * Check maximum pdu size(0x00FFFFFF).
317                  */
318                 if (pdu_size > MAX_STREAM_PROT_LEN)
319                         break;
320
321                 if (pdu_size < SMB1_MIN_SUPPORTED_HEADER_SIZE)
322                         break;
323
324                 /* 4 for rfc1002 length field */
325                 /* 1 for implied bcc[0] */
326                 size = pdu_size + 4 + 1;
327                 conn->request_buf = kvmalloc(size, GFP_KERNEL);
328                 if (!conn->request_buf)
329                         break;
330
331                 memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
332
333                 /*
334                  * We already read 4 bytes to find out PDU size, now
335                  * read in PDU
336                  */
337                 size = t->ops->read(t, conn->request_buf + 4, pdu_size, 2);
338                 if (size < 0) {
339                         pr_err("sock_read failed: %d\n", size);
340                         break;
341                 }
342
343                 if (size != pdu_size) {
344                         pr_err("PDU error. Read: %d, Expected: %d\n",
345                                size, pdu_size);
346                         continue;
347                 }
348
349                 if (!ksmbd_smb_request(conn))
350                         break;
351
352                 if (((struct smb2_hdr *)smb2_get_msg(conn->request_buf))->ProtocolId ==
353                     SMB2_PROTO_NUMBER) {
354                         if (pdu_size < SMB2_MIN_SUPPORTED_HEADER_SIZE)
355                                 break;
356                 }
357
358                 if (!default_conn_ops.process_fn) {
359                         pr_err("No connection request callback\n");
360                         break;
361                 }
362
363                 if (default_conn_ops.process_fn(conn)) {
364                         pr_err("Cannot handle request\n");
365                         break;
366                 }
367         }
368
369 out:
370         ksmbd_conn_set_releasing(conn);
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         if (IS_ENABLED(CONFIG_UNICODE))
375                 utf8_unload(conn->um);
376         unload_nls(conn->local_nls);
377         if (default_conn_ops.terminate_fn)
378                 default_conn_ops.terminate_fn(conn);
379         t->ops->disconnect(t);
380         module_put(THIS_MODULE);
381         return 0;
382 }
383
384 void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
385 {
386         default_conn_ops.process_fn = ops->process_fn;
387         default_conn_ops.terminate_fn = ops->terminate_fn;
388 }
389
390 int ksmbd_conn_transport_init(void)
391 {
392         int ret;
393
394         mutex_lock(&init_lock);
395         ret = ksmbd_tcp_init();
396         if (ret) {
397                 pr_err("Failed to init TCP subsystem: %d\n", ret);
398                 goto out;
399         }
400
401         ret = ksmbd_rdma_init();
402         if (ret) {
403                 pr_err("Failed to init RDMA subsystem: %d\n", ret);
404                 goto out;
405         }
406 out:
407         mutex_unlock(&init_lock);
408         return ret;
409 }
410
411 static void stop_sessions(void)
412 {
413         struct ksmbd_conn *conn;
414         struct ksmbd_transport *t;
415
416 again:
417         down_read(&conn_list_lock);
418         list_for_each_entry(conn, &conn_list, conns_list) {
419                 t = conn->transport;
420                 ksmbd_conn_set_exiting(conn);
421                 if (t->ops->shutdown) {
422                         up_read(&conn_list_lock);
423                         t->ops->shutdown(t);
424                         down_read(&conn_list_lock);
425                 }
426         }
427         up_read(&conn_list_lock);
428
429         if (!list_empty(&conn_list)) {
430                 schedule_timeout_interruptible(HZ / 10); /* 100ms */
431                 goto again;
432         }
433 }
434
435 void ksmbd_conn_transport_destroy(void)
436 {
437         mutex_lock(&init_lock);
438         ksmbd_tcp_destroy();
439         ksmbd_rdma_destroy();
440         stop_sessions();
441         mutex_unlock(&init_lock);
442 }