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         struct ksmbd_conn *bind_conn;
 171
 172         wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
 173
 174         down_read(&conn_list_lock);
 175         list_for_each_entry(bind_conn, &conn_list, conns_list) {
 176                 if (bind_conn == conn)
 177                         continue;
 178
 179                 if ((bind_conn->binding || xa_load(&bind_conn->sessions, sess_id)) &&
 180                     !ksmbd_conn_releasing(bind_conn) &&
 181                     atomic_read(&bind_conn->req_running)) {
 182                         wait_event(bind_conn->req_running_q,
 183                                 atomic_read(&bind_conn->req_running) == 0);
 184                 }
 185         }
 186         up_read(&conn_list_lock);
 187 }
 188
 189 int ksmbd_conn_write(struct ksmbd_work *work)
 190 {
 191         struct ksmbd_conn *conn = work->conn;
 192         int sent;
 193
 194         if (!work->response_buf) {
 195                 pr_err("NULL response header\n");
 196                 return -EINVAL;
 197         }
 198
 199         if (work->send_no_response)
 200                 return 0;
 201
 202         if (!work->iov_idx)
 203                 return -EINVAL;
 204
 205         ksmbd_conn_lock(conn);
 206         sent = conn->transport->ops->writev(conn->transport, work->iov,
 207                         work->iov_cnt,
 208                         get_rfc1002_len(work->iov[0].iov_base) + 4,
 209                         work->need_invalidate_rkey,
 210                         work->remote_key);
 211         ksmbd_conn_unlock(conn);
 212
 213         if (sent < 0) {
 214                 pr_err("Failed to send message: %d\n", sent);
 215                 return sent;
 216         }
 217
 218         return 0;
 219 }
 220
 221 int ksmbd_conn_rdma_read(struct ksmbd_conn *conn,
 222                          void *buf, unsigned int buflen,
 223                          struct smb2_buffer_desc_v1 *desc,
 224                          unsigned int desc_len)
 225 {
 226         int ret = -EINVAL;
 227
 228         if (conn->transport->ops->rdma_read)
 229                 ret = conn->transport->ops->rdma_read(conn->transport,
 230                                                       buf, buflen,
 231                                                       desc, desc_len);
 232         return ret;
 233 }
 234
 235 int ksmbd_conn_rdma_write(struct ksmbd_conn *conn,
 236                           void *buf, unsigned int buflen,
 237                           struct smb2_buffer_desc_v1 *desc,
 238                           unsigned int desc_len)
 239 {
 240         int ret = -EINVAL;
 241
 242         if (conn->transport->ops->rdma_write)
 243                 ret = conn->transport->ops->rdma_write(conn->transport,
 244                                                        buf, buflen,
 245                                                        desc, desc_len);
 246         return ret;
 247 }
 248
 249 bool ksmbd_conn_alive(struct ksmbd_conn *conn)
 250 {
 251         if (!ksmbd_server_running())
 252                 return false;
 253
 254         if (ksmbd_conn_exiting(conn))
 255                 return false;
 256
 257         if (kthread_should_stop())
 258                 return false;
 259
 260         if (atomic_read(&conn->stats.open_files_count) > 0)
 261                 return true;
 262
 263         /*
 264          * Stop current session if the time that get last request from client
 265          * is bigger than deadtime user configured and opening file count is
 266          * zero.
 267          */
 268         if (server_conf.deadtime > 0 &&
 269             time_after(jiffies, conn->last_active + server_conf.deadtime)) {
 270                 ksmbd_debug(CONN, "No response from client in %lu minutes\n",
 271                             server_conf.deadtime / SMB_ECHO_INTERVAL);
 272                 return false;
 273         }
 274         return true;
 275 }
 276
 277 #define SMB1_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb_hdr))
 278 #define SMB2_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb2_hdr) + 4)
 279
 280 /**
 281  * ksmbd_conn_handler_loop() - session thread to listen on new smb requests
 282  * @p:          connection instance
 283  *
 284  * One thread each per connection
 285  *
 286  * Return:      0 on success
 287  */
 288 int ksmbd_conn_handler_loop(void *p)
 289 {
 290         struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
 291         struct ksmbd_transport *t = conn->transport;
 292         unsigned int pdu_size, max_allowed_pdu_size;
 293         char hdr_buf[4] = {0,};
 294         int size;
 295
 296         mutex_init(&conn->srv_mutex);
 297         __module_get(THIS_MODULE);
 298
 299         if (t->ops->prepare && t->ops->prepare(t))
 300                 goto out;
 301
 302         conn->last_active = jiffies;
 303         while (ksmbd_conn_alive(conn)) {
 304                 if (try_to_freeze())
 305                         continue;
 306
 307                 kvfree(conn->request_buf);
 308                 conn->request_buf = NULL;
 309
 310                 size = t->ops->read(t, hdr_buf, sizeof(hdr_buf), -1);
 311                 if (size != sizeof(hdr_buf))
 312                         break;
 313
 314                 pdu_size = get_rfc1002_len(hdr_buf);
 315                 ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
 316
 317                 if (ksmbd_conn_good(conn))
 318                         max_allowed_pdu_size =
 319                                 SMB3_MAX_MSGSIZE + conn->vals->max_write_size;
 320                 else
 321                         max_allowed_pdu_size = SMB3_MAX_MSGSIZE;
 322
 323                 if (pdu_size > max_allowed_pdu_size) {
 324                         pr_err_ratelimited("PDU length(%u) exceeded maximum allowed pdu size(%u) on connection(%d)\n",
 325                                         pdu_size, max_allowed_pdu_size,
 326                                         READ_ONCE(conn->status));
 327                         break;
 328                 }
 329
 330                 /*
 331                  * Check maximum pdu size(0x00FFFFFF).
 332                  */
 333                 if (pdu_size > MAX_STREAM_PROT_LEN)
 334                         break;
 335
 336                 if (pdu_size < SMB1_MIN_SUPPORTED_HEADER_SIZE)
 337                         break;
 338
 339                 /* 4 for rfc1002 length field */
 340                 /* 1 for implied bcc[0] */
 341                 size = pdu_size + 4 + 1;
 342                 conn->request_buf = kvmalloc(size, GFP_KERNEL);
 343                 if (!conn->request_buf)
 344                         break;
 345
 346                 memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
 347
 348                 /*
 349                  * We already read 4 bytes to find out PDU size, now
 350                  * read in PDU
 351                  */
 352                 size = t->ops->read(t, conn->request_buf + 4, pdu_size, 2);
 353                 if (size < 0) {
 354                         pr_err("sock_read failed: %d\n", size);
 355                         break;
 356                 }
 357
 358                 if (size != pdu_size) {
 359                         pr_err("PDU error. Read: %d, Expected: %d\n",
 360                                size, pdu_size);
 361                         continue;
 362                 }
 363
 364                 if (!ksmbd_smb_request(conn))
 365                         break;
 366
 367                 if (((struct smb2_hdr *)smb2_get_msg(conn->request_buf))->ProtocolId ==
 368                     SMB2_PROTO_NUMBER) {
 369                         if (pdu_size < SMB2_MIN_SUPPORTED_HEADER_SIZE)
 370                                 break;
 371                 }
 372
 373                 if (!default_conn_ops.process_fn) {
 374                         pr_err("No connection request callback\n");
 375                         break;
 376                 }
 377
 378                 if (default_conn_ops.process_fn(conn)) {
 379                         pr_err("Cannot handle request\n");
 380                         break;
 381                 }
 382         }
 383
 384 out:
 385         ksmbd_conn_set_releasing(conn);
 386         /* Wait till all reference dropped to the Server object*/
 387         wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);
 388
 389         if (IS_ENABLED(CONFIG_UNICODE))
 390                 utf8_unload(conn->um);
 391         unload_nls(conn->local_nls);
 392         if (default_conn_ops.terminate_fn)
 393                 default_conn_ops.terminate_fn(conn);
 394         t->ops->disconnect(t);
 395         module_put(THIS_MODULE);
 396         return 0;
 397 }
 398
 399 void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
 400 {
 401         default_conn_ops.process_fn = ops->process_fn;
 402         default_conn_ops.terminate_fn = ops->terminate_fn;
 403 }
 404
 405 int ksmbd_conn_transport_init(void)
 406 {
 407         int ret;
 408
 409         mutex_lock(&init_lock);
 410         ret = ksmbd_tcp_init();
 411         if (ret) {
 412                 pr_err("Failed to init TCP subsystem: %d\n", ret);
 413                 goto out;
 414         }
 415
 416         ret = ksmbd_rdma_init();
 417         if (ret) {
 418                 pr_err("Failed to init RDMA subsystem: %d\n", ret);
 419                 goto out;
 420         }
 421 out:
 422         mutex_unlock(&init_lock);
 423         return ret;
 424 }
 425
 426 static void stop_sessions(void)
 427 {
 428         struct ksmbd_conn *conn;
 429         struct ksmbd_transport *t;
 430
 431 again:
 432         down_read(&conn_list_lock);
 433         list_for_each_entry(conn, &conn_list, conns_list) {
 434                 struct task_struct *task;
 435
 436                 t = conn->transport;
 437                 task = t->handler;
 438                 if (task)
 439                         ksmbd_debug(CONN, "Stop session handler %s/%d\n",
 440                                     task->comm, task_pid_nr(task));
 441                 ksmbd_conn_set_exiting(conn);
 442                 if (t->ops->shutdown) {
 443                         up_read(&conn_list_lock);
 444                         t->ops->shutdown(t);
 445                         down_read(&conn_list_lock);
 446                 }
 447         }
 448         up_read(&conn_list_lock);
 449
 450         if (!list_empty(&conn_list)) {
 451                 schedule_timeout_interruptible(HZ / 10); /* 100ms */
 452                 goto again;
 453         }
 454 }
 455
 456 void ksmbd_conn_transport_destroy(void)
 457 {
 458         mutex_lock(&init_lock);
 459         ksmbd_tcp_destroy();
 460         ksmbd_rdma_destroy();
 461         stop_sessions();
 462         mutex_unlock(&init_lock);
 463 }