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 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         down_write(&conn_list_lock);
  88         list_add(&conn->conns_list, &conn_list);
  89         up_write(&conn_list_lock);
  90         return conn;
  91 }
  92
  93 bool ksmbd_conn_lookup_dialect(struct ksmbd_conn *c)
  94 {
  95         struct ksmbd_conn *t;
  96         bool ret = false;
  97
  98         down_read(&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         up_read(&conn_list_lock);
 107         return ret;
 108 }
 109
 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
 118         if (requests_queue) {
 119                 atomic_inc(&conn->req_running);
 120                 spin_lock(&conn->request_lock);
 121                 list_add_tail(&work->request_entry, requests_queue);
 122                 spin_unlock(&conn->request_lock);
 123         }
 124 }
 125
 126 void ksmbd_conn_try_dequeue_request(struct ksmbd_work *work)
 127 {
 128         struct ksmbd_conn *conn = work->conn;
 129
 130         if (list_empty(&work->request_entry) &&
 131             list_empty(&work->async_request_entry))
 132                 return;
 133
 134         atomic_dec(&conn->req_running);
 135         spin_lock(&conn->request_lock);
 136         list_del_init(&work->request_entry);
 137         spin_unlock(&conn->request_lock);
 138         if (work->asynchronous)
 139                 release_async_work(work);
 140
 141         wake_up_all(&conn->req_running_q);
 142 }
 143
 144 void ksmbd_conn_lock(struct ksmbd_conn *conn)
 145 {
 146         mutex_lock(&conn->srv_mutex);
 147 }
 148
 149 void ksmbd_conn_unlock(struct ksmbd_conn *conn)
 150 {
 151         mutex_unlock(&conn->srv_mutex);
 152 }
 153
 154 void ksmbd_all_conn_set_status(u64 sess_id, u32 status)
 155 {
 156         struct ksmbd_conn *conn;
 157
 158         down_read(&conn_list_lock);
 159         list_for_each_entry(conn, &conn_list, conns_list) {
 160                 if (conn->binding || xa_load(&conn->sessions, sess_id))
 161                         WRITE_ONCE(conn->status, status);
 162         }
 163         up_read(&conn_list_lock);
 164 }
 165
 166 void ksmbd_conn_wait_idle(struct ksmbd_conn *conn, u64 sess_id)
 167 {
 168         struct ksmbd_conn *bind_conn;
 169
 170         wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
 171
 172         down_read(&conn_list_lock);
 173         list_for_each_entry(bind_conn, &conn_list, conns_list) {
 174                 if (bind_conn == conn)
 175                         continue;
 176
 177                 if ((bind_conn->binding || xa_load(&bind_conn->sessions, sess_id)) &&
 178                     !ksmbd_conn_releasing(bind_conn) &&
 179                     atomic_read(&bind_conn->req_running)) {
 180                         wait_event(bind_conn->req_running_q,
 181                                 atomic_read(&bind_conn->req_running) == 0);
 182                 }
 183         }
 184         up_read(&conn_list_lock);
 185 }
 186
 187 int ksmbd_conn_write(struct ksmbd_work *work)
 188 {
 189         struct ksmbd_conn *conn = work->conn;
 190         int sent;
 191
 192         if (!work->response_buf) {
 193                 pr_err("NULL response header\n");
 194                 return -EINVAL;
 195         }
 196
 197         if (work->send_no_response)
 198                 return 0;
 199
 200         if (!work->iov_idx)
 201                 return -EINVAL;
 202
 203         ksmbd_conn_lock(conn);
 204         sent = conn->transport->ops->writev(conn->transport, work->iov,
 205                         work->iov_cnt,
 206                         get_rfc1002_len(work->iov[0].iov_base) + 4,
 207                         work->need_invalidate_rkey,
 208                         work->remote_key);
 209         ksmbd_conn_unlock(conn);
 210
 211         if (sent < 0) {
 212                 pr_err("Failed to send message: %d\n", sent);
 213                 return sent;
 214         }
 215
 216         return 0;
 217 }
 218
 219 int ksmbd_conn_rdma_read(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_read)
 227                 ret = conn->transport->ops->rdma_read(conn->transport,
 228                                                       buf, buflen,
 229                                                       desc, desc_len);
 230         return ret;
 231 }
 232
 233 int ksmbd_conn_rdma_write(struct ksmbd_conn *conn,
 234                           void *buf, unsigned int buflen,
 235                           struct smb2_buffer_desc_v1 *desc,
 236                           unsigned int desc_len)
 237 {
 238         int ret = -EINVAL;
 239
 240         if (conn->transport->ops->rdma_write)
 241                 ret = conn->transport->ops->rdma_write(conn->transport,
 242                                                        buf, buflen,
 243                                                        desc, desc_len);
 244         return ret;
 245 }
 246
 247 bool ksmbd_conn_alive(struct ksmbd_conn *conn)
 248 {
 249         if (!ksmbd_server_running())
 250                 return false;
 251
 252         if (ksmbd_conn_exiting(conn))
 253                 return false;
 254
 255         if (kthread_should_stop())
 256                 return false;
 257
 258         if (atomic_read(&conn->stats.open_files_count) > 0)
 259                 return true;
 260
 261         /*
 262          * Stop current session if the time that get last request from client
 263          * is bigger than deadtime user configured and opening file count is
 264          * zero.
 265          */
 266         if (server_conf.deadtime > 0 &&
 267             time_after(jiffies, conn->last_active + server_conf.deadtime)) {
 268                 ksmbd_debug(CONN, "No response from client in %lu minutes\n",
 269                             server_conf.deadtime / SMB_ECHO_INTERVAL);
 270                 return false;
 271         }
 272         return true;
 273 }
 274
 275 #define SMB1_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb_hdr))
 276 #define SMB2_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb2_hdr) + 4)
 277
 278 /**
 279  * ksmbd_conn_handler_loop() - session thread to listen on new smb requests
 280  * @p:          connection instance
 281  *
 282  * One thread each per connection
 283  *
 284  * Return:      0 on success
 285  */
 286 int ksmbd_conn_handler_loop(void *p)
 287 {
 288         struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
 289         struct ksmbd_transport *t = conn->transport;
 290         unsigned int pdu_size, max_allowed_pdu_size;
 291         char hdr_buf[4] = {0,};
 292         int size;
 293
 294         mutex_init(&conn->srv_mutex);
 295         __module_get(THIS_MODULE);
 296
 297         if (t->ops->prepare && t->ops->prepare(t))
 298                 goto out;
 299
 300         conn->last_active = jiffies;
 301         while (ksmbd_conn_alive(conn)) {
 302                 if (try_to_freeze())
 303                         continue;
 304
 305                 kvfree(conn->request_buf);
 306                 conn->request_buf = NULL;
 307
 308                 size = t->ops->read(t, hdr_buf, sizeof(hdr_buf), -1);
 309                 if (size != sizeof(hdr_buf))
 310                         break;
 311
 312                 pdu_size = get_rfc1002_len(hdr_buf);
 313                 ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
 314
 315                 if (ksmbd_conn_good(conn))
 316                         max_allowed_pdu_size =
 317                                 SMB3_MAX_MSGSIZE + conn->vals->max_write_size;
 318                 else
 319                         max_allowed_pdu_size = SMB3_MAX_MSGSIZE;
 320
 321                 if (pdu_size > max_allowed_pdu_size) {
 322                         pr_err_ratelimited("PDU length(%u) exceeded maximum allowed pdu size(%u) on connection(%d)\n",
 323                                         pdu_size, max_allowed_pdu_size,
 324                                         READ_ONCE(conn->status));
 325                         break;
 326                 }
 327
 328                 /*
 329                  * Check maximum pdu size(0x00FFFFFF).
 330                  */
 331                 if (pdu_size > MAX_STREAM_PROT_LEN)
 332                         break;
 333
 334                 if (pdu_size < SMB1_MIN_SUPPORTED_HEADER_SIZE)
 335                         break;
 336
 337                 /* 4 for rfc1002 length field */
 338                 /* 1 for implied bcc[0] */
 339                 size = pdu_size + 4 + 1;
 340                 conn->request_buf = kvmalloc(size, GFP_KERNEL);
 341                 if (!conn->request_buf)
 342                         break;
 343
 344                 memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
 345
 346                 /*
 347                  * We already read 4 bytes to find out PDU size, now
 348                  * read in PDU
 349                  */
 350                 size = t->ops->read(t, conn->request_buf + 4, pdu_size, 2);
 351                 if (size < 0) {
 352                         pr_err("sock_read failed: %d\n", size);
 353                         break;
 354                 }
 355
 356                 if (size != pdu_size) {
 357                         pr_err("PDU error. Read: %d, Expected: %d\n",
 358                                size, pdu_size);
 359                         continue;
 360                 }
 361
 362                 if (!ksmbd_smb_request(conn))
 363                         break;
 364
 365                 if (((struct smb2_hdr *)smb2_get_msg(conn->request_buf))->ProtocolId ==
 366                     SMB2_PROTO_NUMBER) {
 367                         if (pdu_size < SMB2_MIN_SUPPORTED_HEADER_SIZE)
 368                                 break;
 369                 }
 370
 371                 if (!default_conn_ops.process_fn) {
 372                         pr_err("No connection request callback\n");
 373                         break;
 374                 }
 375
 376                 if (default_conn_ops.process_fn(conn)) {
 377                         pr_err("Cannot handle request\n");
 378                         break;
 379                 }
 380         }
 381
 382 out:
 383         ksmbd_conn_set_releasing(conn);
 384         /* Wait till all reference dropped to the Server object*/
 385         wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);
 386
 387         if (IS_ENABLED(CONFIG_UNICODE))
 388                 utf8_unload(conn->um);
 389         unload_nls(conn->local_nls);
 390         if (default_conn_ops.terminate_fn)
 391                 default_conn_ops.terminate_fn(conn);
 392         t->ops->disconnect(t);
 393         module_put(THIS_MODULE);
 394         return 0;
 395 }
 396
 397 void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
 398 {
 399         default_conn_ops.process_fn = ops->process_fn;
 400         default_conn_ops.terminate_fn = ops->terminate_fn;
 401 }
 402
 403 int ksmbd_conn_transport_init(void)
 404 {
 405         int ret;
 406
 407         mutex_lock(&init_lock);
 408         ret = ksmbd_tcp_init();
 409         if (ret) {
 410                 pr_err("Failed to init TCP subsystem: %d\n", ret);
 411                 goto out;
 412         }
 413
 414         ret = ksmbd_rdma_init();
 415         if (ret) {
 416                 pr_err("Failed to init RDMA subsystem: %d\n", ret);
 417                 goto out;
 418         }
 419 out:
 420         mutex_unlock(&init_lock);
 421         return ret;
 422 }
 423
 424 static void stop_sessions(void)
 425 {
 426         struct ksmbd_conn *conn;
 427         struct ksmbd_transport *t;
 428
 429 again:
 430         down_read(&conn_list_lock);
 431         list_for_each_entry(conn, &conn_list, conns_list) {
 432                 struct task_struct *task;
 433
 434                 t = conn->transport;
 435                 task = t->handler;
 436                 if (task)
 437                         ksmbd_debug(CONN, "Stop session handler %s/%d\n",
 438                                     task->comm, task_pid_nr(task));
 439                 ksmbd_conn_set_exiting(conn);
 440                 if (t->ops->shutdown) {
 441                         up_read(&conn_list_lock);
 442                         t->ops->shutdown(t);
 443                         down_read(&conn_list_lock);
 444                 }
 445         }
 446         up_read(&conn_list_lock);
 447
 448         if (!list_empty(&conn_list)) {
 449                 schedule_timeout_interruptible(HZ / 10); /* 100ms */
 450                 goto again;
 451         }
 452 }
 453
 454 void ksmbd_conn_transport_destroy(void)
 455 {
 456         mutex_lock(&init_lock);
 457         ksmbd_tcp_destroy();
 458         ksmbd_rdma_destroy();
 459         stop_sessions();
 460         mutex_unlock(&init_lock);
 461 }