fs/smb/server/connection.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *   Copyright (C) 2016 Namjae Jeon <[email protected]>
   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  */
  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  */
  51 struct 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
  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
 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         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
 130 void 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
 151 void ksmbd_conn_lock(struct ksmbd_conn *conn)
 152 {
 153         mutex_lock(&conn->srv_mutex);
 154 }
 155
 156 void ksmbd_conn_unlock(struct ksmbd_conn *conn)
 157 {
 158         mutex_unlock(&conn->srv_mutex);
 159 }
 160
 161 void 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
 173 void ksmbd_conn_wait_idle(struct ksmbd_conn *conn)
 174 {
 175         wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
 176 }
 177
 178 int 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
 184 retry_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
 210 int 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
 242 int 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
 256 int 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
 270 bool 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  */
 309 int 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
 333 recheck:
 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
 414 out:
 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
 430 void 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
 436 int 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         }
 452 out:
 453         mutex_unlock(&init_lock);
 454         return ret;
 455 }
 456
 457 static void stop_sessions(void)
 458 {
 459         struct ksmbd_conn *conn;
 460         struct ksmbd_transport *t;
 461
 462 again:
 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
 481 void 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 }