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
 18static DEFINE_MUTEX(init_lock);
 19
 20static struct ksmbd_conn_ops default_conn_ops;
 21
 22DEFINE_HASHTABLE(conn_list, CONN_HASH_BITS);
 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	hash_del(&conn->hlist);
 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->mechToken);
 43	if (atomic_dec_and_test(&conn->refcnt)) {
 44		conn->transport->ops->free_transport(conn->transport);
 45		kfree(conn);
 46	}
 47}
 48
 49/**
 50 * ksmbd_conn_alloc() - initialize a new connection instance
 51 *
 52 * Return:	ksmbd_conn struct on success, otherwise NULL
 53 */
 54struct ksmbd_conn *ksmbd_conn_alloc(void)
 55{
 56	struct ksmbd_conn *conn;
 57
 58	conn = kzalloc(sizeof(struct ksmbd_conn), KSMBD_DEFAULT_GFP);
 59	if (!conn)
 60		return NULL;
 61
 62	conn->need_neg = true;
 63	ksmbd_conn_set_new(conn);
 64	conn->local_nls = load_nls("utf8");
 65	if (!conn->local_nls)
 66		conn->local_nls = load_nls_default();
 67	if (IS_ENABLED(CONFIG_UNICODE))
 68		conn->um = utf8_load(UNICODE_AGE(12, 1, 0));
 69	else
 70		conn->um = ERR_PTR(-EOPNOTSUPP);
 71	if (IS_ERR(conn->um))
 72		conn->um = NULL;
 73	atomic_set(&conn->req_running, 0);
 74	atomic_set(&conn->r_count, 0);
 75	atomic_set(&conn->refcnt, 1);
 76	conn->total_credits = 1;
 77	conn->outstanding_credits = 0;
 78
 79	init_waitqueue_head(&conn->req_running_q);
 80	init_waitqueue_head(&conn->r_count_q);
 81	INIT_LIST_HEAD(&conn->requests);
 82	INIT_LIST_HEAD(&conn->async_requests);
 83	spin_lock_init(&conn->request_lock);
 84	spin_lock_init(&conn->credits_lock);
 85	ida_init(&conn->async_ida);
 86	xa_init(&conn->sessions);
 87
 88	spin_lock_init(&conn->llist_lock);
 89	INIT_LIST_HEAD(&conn->lock_list);
 90
 91	init_rwsem(&conn->session_lock);
 92
 93	return conn;
 94}
 95
 96bool ksmbd_conn_lookup_dialect(struct ksmbd_conn *c)
 97{
 98	struct ksmbd_conn *t;
 99	int bkt;
100	bool ret = false;
101
102	down_read(&conn_list_lock);
103	hash_for_each(conn_list, bkt, t, hlist) {
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	int bkt;
165
166	down_read(&conn_list_lock);
167	hash_for_each(conn_list, bkt, conn, hlist) {
168		if (conn->binding || xa_load(&conn->sessions, sess_id))
169			WRITE_ONCE(conn->status, status);
170	}
171	up_read(&conn_list_lock);
172}
173
174void ksmbd_conn_wait_idle(struct ksmbd_conn *conn)
175{
176	wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
177}
178
179int ksmbd_conn_wait_idle_sess_id(struct ksmbd_conn *curr_conn, u64 sess_id)
180{
181	struct ksmbd_conn *conn;
182	int rc, retry_count = 0, max_timeout = 120;
183	int rcount = 1, bkt;
184
185retry_idle:
186	if (retry_count >= max_timeout)
187		return -EIO;
188
189	down_read(&conn_list_lock);
190	hash_for_each(conn_list, bkt, conn, hlist) {
191		if (conn->binding || xa_load(&conn->sessions, sess_id)) {
192			if (conn == curr_conn)
193				rcount = 2;
194			if (atomic_read(&conn->req_running) >= rcount) {
195				rc = wait_event_timeout(conn->req_running_q,
196					atomic_read(&conn->req_running) < rcount,
197					HZ);
198				if (!rc) {
199					up_read(&conn_list_lock);
200					retry_count++;
201					goto retry_idle;
202				}
203			}
204		}
205	}
206	up_read(&conn_list_lock);
207
208	return 0;
209}
210
211int ksmbd_conn_write(struct ksmbd_work *work)
212{
213	struct ksmbd_conn *conn = work->conn;
214	int sent;
215
216	if (!work->response_buf) {
217		pr_err("NULL response header\n");
218		return -EINVAL;
219	}
220
221	if (work->send_no_response)
222		return 0;
223
224	if (!work->iov_idx)
225		return -EINVAL;
226
227	ksmbd_conn_lock(conn);
228	sent = conn->transport->ops->writev(conn->transport, work->iov,
229			work->iov_cnt,
230			get_rfc1002_len(work->iov[0].iov_base) + 4,
231			work->need_invalidate_rkey,
232			work->remote_key);
233	ksmbd_conn_unlock(conn);
234
235	if (sent < 0) {
236		pr_err("Failed to send message: %d\n", sent);
237		return sent;
238	}
239
240	return 0;
241}
242
243int ksmbd_conn_rdma_read(struct ksmbd_conn *conn,
244			 void *buf, unsigned int buflen,
245			 struct smbdirect_buffer_descriptor_v1 *desc,
246			 unsigned int desc_len)
247{
248	int ret = -EINVAL;
249
250	if (conn->transport->ops->rdma_read)
251		ret = conn->transport->ops->rdma_read(conn->transport,
252						      buf, buflen,
253						      desc, desc_len);
254	return ret;
255}
256
257int ksmbd_conn_rdma_write(struct ksmbd_conn *conn,
258			  void *buf, unsigned int buflen,
259			  struct smbdirect_buffer_descriptor_v1 *desc,
260			  unsigned int desc_len)
261{
262	int ret = -EINVAL;
263
264	if (conn->transport->ops->rdma_write)
265		ret = conn->transport->ops->rdma_write(conn->transport,
266						       buf, buflen,
267						       desc, desc_len);
268	return ret;
269}
270
271bool ksmbd_conn_alive(struct ksmbd_conn *conn)
272{
273	if (!ksmbd_server_running())
274		return false;
275
276	if (ksmbd_conn_exiting(conn))
277		return false;
278
279	if (kthread_should_stop())
280		return false;
281
282	if (atomic_read(&conn->stats.open_files_count) > 0)
283		return true;
284
285	/*
286	 * Stop current session if the time that get last request from client
287	 * is bigger than deadtime user configured and opening file count is
288	 * zero.
289	 */
290	if (server_conf.deadtime > 0 &&
291	    time_after(jiffies, conn->last_active + server_conf.deadtime)) {
292		ksmbd_debug(CONN, "No response from client in %lu minutes\n",
293			    server_conf.deadtime / SMB_ECHO_INTERVAL);
294		return false;
295	}
296	return true;
297}
298
299/* "+2" for BCC field (ByteCount, 2 bytes) */
300#define SMB1_MIN_SUPPORTED_PDU_SIZE (sizeof(struct smb_hdr) + 2)
301#define SMB2_MIN_SUPPORTED_PDU_SIZE (sizeof(struct smb2_pdu))
302
303/**
304 * ksmbd_conn_handler_loop() - session thread to listen on new smb requests
305 * @p:		connection instance
306 *
307 * One thread each per connection
308 *
309 * Return:	0 on success
310 */
311int ksmbd_conn_handler_loop(void *p)
312{
313	struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
314	struct ksmbd_transport *t = conn->transport;
315	unsigned int pdu_size, max_allowed_pdu_size, max_req;
316	char hdr_buf[4] = {0,};
317	int size;
318
319	mutex_init(&conn->srv_mutex);
320	__module_get(THIS_MODULE);
321
322	if (t->ops->prepare && t->ops->prepare(t))
323		goto out;
324
325	max_req = server_conf.max_inflight_req;
326	conn->last_active = jiffies;
327	set_freezable();
328	while (ksmbd_conn_alive(conn)) {
329		if (try_to_freeze())
330			continue;
331
332		kvfree(conn->request_buf);
333		conn->request_buf = NULL;
334
335recheck:
336		if (atomic_read(&conn->req_running) + 1 > max_req) {
337			wait_event_interruptible(conn->req_running_q,
338				atomic_read(&conn->req_running) < max_req);
339			goto recheck;
340		}
341
342		size = t->ops->read(t, hdr_buf, sizeof(hdr_buf), -1);
343		if (size != sizeof(hdr_buf))
344			break;
345
346		pdu_size = get_rfc1002_len(hdr_buf);
347		ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
348
349		if (ksmbd_conn_good(conn))
350			max_allowed_pdu_size =
351				SMB3_MAX_MSGSIZE + conn->vals->max_write_size;
352		else
353			max_allowed_pdu_size = SMB3_MAX_MSGSIZE;
354
355		if (pdu_size > max_allowed_pdu_size) {
356			pr_err_ratelimited("PDU length(%u) exceeded maximum allowed pdu size(%u) on connection(%d)\n",
357					pdu_size, max_allowed_pdu_size,
358					READ_ONCE(conn->status));
359			break;
360		}
361
362		/*
363		 * Check maximum pdu size(0x00FFFFFF).
364		 */
365		if (pdu_size > MAX_STREAM_PROT_LEN)
366			break;
367
368		if (pdu_size < SMB1_MIN_SUPPORTED_PDU_SIZE)
369			break;
370
371		/* 4 for rfc1002 length field */
372		/* 1 for implied bcc[0] */
373		size = pdu_size + 4 + 1;
374		conn->request_buf = kvmalloc(size, KSMBD_DEFAULT_GFP);
375		if (!conn->request_buf)
376			break;
377
378		memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
379
380		/*
381		 * We already read 4 bytes to find out PDU size, now
382		 * read in PDU
383		 */
384		size = t->ops->read(t, conn->request_buf + 4, pdu_size, 2);
385		if (size < 0) {
386			pr_err("sock_read failed: %d\n", size);
387			break;
388		}
389
390		if (size != pdu_size) {
391			pr_err("PDU error. Read: %d, Expected: %d\n",
392			       size, pdu_size);
393			continue;
394		}
395
396		if (!ksmbd_smb_request(conn))
397			break;
398
399		if (((struct smb2_hdr *)smb_get_msg(conn->request_buf))->ProtocolId ==
400		    SMB2_PROTO_NUMBER) {
401			if (pdu_size < SMB2_MIN_SUPPORTED_PDU_SIZE)
402				break;
403		}
404
405		if (!default_conn_ops.process_fn) {
406			pr_err("No connection request callback\n");
407			break;
408		}
409
410		if (default_conn_ops.process_fn(conn)) {
411			pr_err("Cannot handle request\n");
412			break;
413		}
414	}
415
416out:
417	ksmbd_conn_set_releasing(conn);
418	/* Wait till all reference dropped to the Server object*/
419	ksmbd_debug(CONN, "Wait for all pending requests(%d)\n", atomic_read(&conn->r_count));
420	wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);
421
422	if (IS_ENABLED(CONFIG_UNICODE))
423		utf8_unload(conn->um);
424	unload_nls(conn->local_nls);
425	if (default_conn_ops.terminate_fn)
426		default_conn_ops.terminate_fn(conn);
427	t->ops->disconnect(t);
428	module_put(THIS_MODULE);
429	return 0;
430}
431
432void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
433{
434	default_conn_ops.process_fn = ops->process_fn;
435	default_conn_ops.terminate_fn = ops->terminate_fn;
436}
437
438void ksmbd_conn_r_count_inc(struct ksmbd_conn *conn)
439{
440	atomic_inc(&conn->r_count);
441}
442
443void ksmbd_conn_r_count_dec(struct ksmbd_conn *conn)
444{
445	/*
446	 * Checking waitqueue to dropping pending requests on
447	 * disconnection. waitqueue_active is safe because it
448	 * uses atomic operation for condition.
449	 */
450	atomic_inc(&conn->refcnt);
451	if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q))
452		wake_up(&conn->r_count_q);
453
454	if (atomic_dec_and_test(&conn->refcnt))
455		kfree(conn);
456}
457
458int ksmbd_conn_transport_init(void)
459{
460	int ret;
461
462	mutex_lock(&init_lock);
463	ret = ksmbd_tcp_init();
464	if (ret) {
465		pr_err("Failed to init TCP subsystem: %d\n", ret);
466		goto out;
467	}
468
469	ret = ksmbd_rdma_init();
470	if (ret) {
471		pr_err("Failed to init RDMA subsystem: %d\n", ret);
472		goto out;
473	}
474out:
475	mutex_unlock(&init_lock);
476	return ret;
477}
478
479static void stop_sessions(void)
480{
481	struct ksmbd_conn *conn;
482	struct ksmbd_transport *t;
483	int bkt;
484
485again:
486	down_read(&conn_list_lock);
487	hash_for_each(conn_list, bkt, conn, hlist) {
488		t = conn->transport;
489		ksmbd_conn_set_exiting(conn);
490		if (t->ops->shutdown) {
491			up_read(&conn_list_lock);
492			t->ops->shutdown(t);
493			down_read(&conn_list_lock);
494		}
495	}
496	up_read(&conn_list_lock);
497
498	if (!hash_empty(conn_list)) {
499		msleep(100);
500		goto again;
501	}
502}
503
504void ksmbd_conn_transport_destroy(void)
505{
506	mutex_lock(&init_lock);
507	ksmbd_tcp_destroy();
508	ksmbd_rdma_stop_listening();
509	stop_sessions();
510	ksmbd_rdma_destroy();
511	mutex_unlock(&init_lock);
512}