fs/smb/server/server.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *   Copyright (C) 2016 Namjae Jeon <linkinjeon@kernel.org>
   4  *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
   5  */
   6
   7 #include "glob.h"
   8 #include "oplock.h"
   9 #include "misc.h"
  10 #include <linux/sched/signal.h>
  11 #include <linux/workqueue.h>
  12 #include <linux/sysfs.h>
  13 #include <linux/module.h>
  14 #include <linux/moduleparam.h>
  15
  16 #include "server.h"
  17 #include "smb_common.h"
  18 #include "smbstatus.h"
  19 #include "connection.h"
  20 #include "transport_ipc.h"
  21 #include "mgmt/user_session.h"
  22 #include "crypto_ctx.h"
  23 #include "auth.h"
  24
  25 int ksmbd_debug_types;
  26
  27 struct ksmbd_server_config server_conf;
  28
  29 enum SERVER_CTRL_TYPE {
  30         SERVER_CTRL_TYPE_INIT,
  31         SERVER_CTRL_TYPE_RESET,
  32 };
  33
  34 struct server_ctrl_struct {
  35         int                     type;
  36         struct work_struct      ctrl_work;
  37 };
  38
  39 static DEFINE_MUTEX(ctrl_lock);
  40
  41 static int ___server_conf_set(int idx, char *val)
  42 {
  43         if (idx >= ARRAY_SIZE(server_conf.conf))
  44                 return -EINVAL;
  45
  46         if (!val || val[0] == 0x00)
  47                 return -EINVAL;
  48
  49         kfree(server_conf.conf[idx]);
  50         server_conf.conf[idx] = kstrdup(val, GFP_KERNEL);
  51         if (!server_conf.conf[idx])
  52                 return -ENOMEM;
  53         return 0;
  54 }
  55
  56 int ksmbd_set_netbios_name(char *v)
  57 {
  58         return ___server_conf_set(SERVER_CONF_NETBIOS_NAME, v);
  59 }
  60
  61 int ksmbd_set_server_string(char *v)
  62 {
  63         return ___server_conf_set(SERVER_CONF_SERVER_STRING, v);
  64 }
  65
  66 int ksmbd_set_work_group(char *v)
  67 {
  68         return ___server_conf_set(SERVER_CONF_WORK_GROUP, v);
  69 }
  70
  71 char *ksmbd_netbios_name(void)
  72 {
  73         return server_conf.conf[SERVER_CONF_NETBIOS_NAME];
  74 }
  75
  76 char *ksmbd_server_string(void)
  77 {
  78         return server_conf.conf[SERVER_CONF_SERVER_STRING];
  79 }
  80
  81 char *ksmbd_work_group(void)
  82 {
  83         return server_conf.conf[SERVER_CONF_WORK_GROUP];
  84 }
  85
  86 /**
  87  * check_conn_state() - check state of server thread connection
  88  * @work:     smb work containing server thread information
  89  *
  90  * Return:      0 on valid connection, otherwise 1 to reconnect
  91  */
  92 static inline int check_conn_state(struct ksmbd_work *work)
  93 {
  94         struct smb_hdr *rsp_hdr;
  95
  96         if (ksmbd_conn_exiting(work->conn) ||
  97             ksmbd_conn_need_reconnect(work->conn)) {
  98                 rsp_hdr = work->response_buf;
  99                 rsp_hdr->Status.CifsError = STATUS_CONNECTION_DISCONNECTED;
 100                 return 1;
 101         }
 102         return 0;
 103 }
 104
 105 #define SERVER_HANDLER_CONTINUE         0
 106 #define SERVER_HANDLER_ABORT            1
 107
 108 static int __process_request(struct ksmbd_work *work, struct ksmbd_conn *conn,
 109                              u16 *cmd)
 110 {
 111         struct smb_version_cmds *cmds;
 112         u16 command;
 113         int ret;
 114
 115         if (check_conn_state(work))
 116                 return SERVER_HANDLER_CONTINUE;
 117
 118         if (ksmbd_verify_smb_message(work))
 119                 return SERVER_HANDLER_ABORT;
 120
 121         command = conn->ops->get_cmd_val(work);
 122         *cmd = command;
 123
 124 andx_again:
 125         if (command >= conn->max_cmds) {
 126                 conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER);
 127                 return SERVER_HANDLER_CONTINUE;
 128         }
 129
 130         cmds = &conn->cmds[command];
 131         if (!cmds->proc) {
 132                 ksmbd_debug(SMB, "*** not implemented yet cmd = %x\n", command);
 133                 conn->ops->set_rsp_status(work, STATUS_NOT_IMPLEMENTED);
 134                 return SERVER_HANDLER_CONTINUE;
 135         }
 136
 137         if (work->sess && conn->ops->is_sign_req(work, command)) {
 138                 ret = conn->ops->check_sign_req(work);
 139                 if (!ret) {
 140                         conn->ops->set_rsp_status(work, STATUS_ACCESS_DENIED);
 141                         return SERVER_HANDLER_CONTINUE;
 142                 }
 143         }
 144
 145         ret = cmds->proc(work);
 146
 147         if (ret < 0)
 148                 ksmbd_debug(CONN, "Failed to process %u [%d]\n", command, ret);
 149         /* AndX commands - chained request can return positive values */
 150         else if (ret > 0) {
 151                 command = ret;
 152                 *cmd = command;
 153                 goto andx_again;
 154         }
 155
 156         if (work->send_no_response)
 157                 return SERVER_HANDLER_ABORT;
 158         return SERVER_HANDLER_CONTINUE;
 159 }
 160
 161 static void __handle_ksmbd_work(struct ksmbd_work *work,
 162                                 struct ksmbd_conn *conn)
 163 {
 164         u16 command = 0;
 165         int rc;
 166
 167         if (conn->ops->allocate_rsp_buf(work))
 168                 return;
 169
 170         if (conn->ops->is_transform_hdr &&
 171             conn->ops->is_transform_hdr(work->request_buf)) {
 172                 rc = conn->ops->decrypt_req(work);
 173                 if (rc < 0) {
 174                         conn->ops->set_rsp_status(work, STATUS_DATA_ERROR);
 175                         goto send;
 176                 }
 177
 178                 work->encrypted = true;
 179         }
 180
 181         rc = conn->ops->init_rsp_hdr(work);
 182         if (rc) {
 183                 /* either uid or tid is not correct */
 184                 conn->ops->set_rsp_status(work, STATUS_INVALID_HANDLE);
 185                 goto send;
 186         }
 187
 188         if (conn->ops->check_user_session) {
 189                 rc = conn->ops->check_user_session(work);
 190                 if (rc < 0) {
 191                         command = conn->ops->get_cmd_val(work);
 192                         conn->ops->set_rsp_status(work,
 193                                         STATUS_USER_SESSION_DELETED);
 194                         goto send;
 195                 } else if (rc > 0) {
 196                         rc = conn->ops->get_ksmbd_tcon(work);
 197                         if (rc < 0) {
 198                                 conn->ops->set_rsp_status(work,
 199                                         STATUS_NETWORK_NAME_DELETED);
 200                                 goto send;
 201                         }
 202                 }
 203         }
 204
 205         do {
 206                 rc = __process_request(work, conn, &command);
 207                 if (rc == SERVER_HANDLER_ABORT)
 208                         break;
 209
 210                 /*
 211                  * Call smb2_set_rsp_credits() function to set number of credits
 212                  * granted in hdr of smb2 response.
 213                  */
 214                 if (conn->ops->set_rsp_credits) {
 215                         spin_lock(&conn->credits_lock);
 216                         rc = conn->ops->set_rsp_credits(work);
 217                         spin_unlock(&conn->credits_lock);
 218                         if (rc < 0) {
 219                                 conn->ops->set_rsp_status(work,
 220                                         STATUS_INVALID_PARAMETER);
 221                                 goto send;
 222                         }
 223                 }
 224
 225                 if (work->sess &&
 226                     (work->sess->sign || smb3_11_final_sess_setup_resp(work) ||
 227                      conn->ops->is_sign_req(work, command)))
 228                         conn->ops->set_sign_rsp(work);
 229         } while (is_chained_smb2_message(work));
 230
 231         if (work->send_no_response)
 232                 return;
 233
 234 send:
 235         smb3_preauth_hash_rsp(work);
 236         if (work->sess && work->sess->enc && work->encrypted &&
 237             conn->ops->encrypt_resp) {
 238                 rc = conn->ops->encrypt_resp(work);
 239                 if (rc < 0)
 240                         conn->ops->set_rsp_status(work, STATUS_DATA_ERROR);
 241         }
 242
 243         ksmbd_conn_write(work);
 244 }
 245
 246 /**
 247  * handle_ksmbd_work() - process pending smb work requests
 248  * @wk: smb work containing request command buffer
 249  *
 250  * called by kworker threads to processing remaining smb work requests
 251  */
 252 static void handle_ksmbd_work(struct work_struct *wk)
 253 {
 254         struct ksmbd_work *work = container_of(wk, struct ksmbd_work, work);
 255         struct ksmbd_conn *conn = work->conn;
 256
 257         atomic64_inc(&conn->stats.request_served);
 258
 259         __handle_ksmbd_work(work, conn);
 260
 261         ksmbd_conn_try_dequeue_request(work);
 262         ksmbd_free_work_struct(work);
 263         /*
 264          * Checking waitqueue to dropping pending requests on
 265          * disconnection. waitqueue_active is safe because it
 266          * uses atomic operation for condition.
 267          */
 268         if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q))
 269                 wake_up(&conn->r_count_q);
 270 }
 271
 272 /**
 273  * queue_ksmbd_work() - queue a smb request to worker thread queue
 274  *              for proccessing smb command and sending response
 275  * @conn:       connection instance
 276  *
 277  * read remaining data from socket create and submit work.
 278  */
 279 static int queue_ksmbd_work(struct ksmbd_conn *conn)
 280 {
 281         struct ksmbd_work *work;
 282
 283         work = ksmbd_alloc_work_struct();
 284         if (!work) {
 285                 pr_err("allocation for work failed\n");
 286                 return -ENOMEM;
 287         }
 288
 289         work->conn = conn;
 290         work->request_buf = conn->request_buf;
 291         conn->request_buf = NULL;
 292
 293         ksmbd_init_smb_server(work);
 294
 295         ksmbd_conn_enqueue_request(work);
 296         atomic_inc(&conn->r_count);
 297         /* update activity on connection */
 298         conn->last_active = jiffies;
 299         INIT_WORK(&work->work, handle_ksmbd_work);
 300         ksmbd_queue_work(work);
 301         return 0;
 302 }
 303
 304 static int ksmbd_server_process_request(struct ksmbd_conn *conn)
 305 {
 306         return queue_ksmbd_work(conn);
 307 }
 308
 309 static int ksmbd_server_terminate_conn(struct ksmbd_conn *conn)
 310 {
 311         ksmbd_sessions_deregister(conn);
 312         destroy_lease_table(conn);
 313         return 0;
 314 }
 315
 316 static void ksmbd_server_tcp_callbacks_init(void)
 317 {
 318         struct ksmbd_conn_ops ops;
 319
 320         ops.process_fn = ksmbd_server_process_request;
 321         ops.terminate_fn = ksmbd_server_terminate_conn;
 322
 323         ksmbd_conn_init_server_callbacks(&ops);
 324 }
 325
 326 static void server_conf_free(void)
 327 {
 328         int i;
 329
 330         for (i = 0; i < ARRAY_SIZE(server_conf.conf); i++) {
 331                 kfree(server_conf.conf[i]);
 332                 server_conf.conf[i] = NULL;
 333         }
 334 }
 335
 336 static int server_conf_init(void)
 337 {
 338         WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
 339         server_conf.enforced_signing = 0;
 340         server_conf.min_protocol = ksmbd_min_protocol();
 341         server_conf.max_protocol = ksmbd_max_protocol();
 342         server_conf.auth_mechs = KSMBD_AUTH_NTLMSSP;
 343 #ifdef CONFIG_SMB_SERVER_KERBEROS5
 344         server_conf.auth_mechs |= KSMBD_AUTH_KRB5 |
 345                                 KSMBD_AUTH_MSKRB5;
 346 #endif
 347         return 0;
 348 }
 349
 350 static void server_ctrl_handle_init(struct server_ctrl_struct *ctrl)
 351 {
 352         int ret;
 353
 354         ret = ksmbd_conn_transport_init();
 355         if (ret) {
 356                 server_queue_ctrl_reset_work();
 357                 return;
 358         }
 359
 360         WRITE_ONCE(server_conf.state, SERVER_STATE_RUNNING);
 361 }
 362
 363 static void server_ctrl_handle_reset(struct server_ctrl_struct *ctrl)
 364 {
 365         ksmbd_ipc_soft_reset();
 366         ksmbd_conn_transport_destroy();
 367         server_conf_free();
 368         server_conf_init();
 369         WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
 370 }
 371
 372 static void server_ctrl_handle_work(struct work_struct *work)
 373 {
 374         struct server_ctrl_struct *ctrl;
 375
 376         ctrl = container_of(work, struct server_ctrl_struct, ctrl_work);
 377
 378         mutex_lock(&ctrl_lock);
 379         switch (ctrl->type) {
 380         case SERVER_CTRL_TYPE_INIT:
 381                 server_ctrl_handle_init(ctrl);
 382                 break;
 383         case SERVER_CTRL_TYPE_RESET:
 384                 server_ctrl_handle_reset(ctrl);
 385                 break;
 386         default:
 387                 pr_err("Unknown server work type: %d\n", ctrl->type);
 388         }
 389         mutex_unlock(&ctrl_lock);
 390         kfree(ctrl);
 391         module_put(THIS_MODULE);
 392 }
 393
 394 static int __queue_ctrl_work(int type)
 395 {
 396         struct server_ctrl_struct *ctrl;
 397
 398         ctrl = kmalloc(sizeof(struct server_ctrl_struct), GFP_KERNEL);
 399         if (!ctrl)
 400                 return -ENOMEM;
 401
 402         __module_get(THIS_MODULE);
 403         ctrl->type = type;
 404         INIT_WORK(&ctrl->ctrl_work, server_ctrl_handle_work);
 405         queue_work(system_long_wq, &ctrl->ctrl_work);
 406         return 0;
 407 }
 408
 409 int server_queue_ctrl_init_work(void)
 410 {
 411         return __queue_ctrl_work(SERVER_CTRL_TYPE_INIT);
 412 }
 413
 414 int server_queue_ctrl_reset_work(void)
 415 {
 416         return __queue_ctrl_work(SERVER_CTRL_TYPE_RESET);
 417 }
 418
 419 static ssize_t stats_show(const struct class *class, const struct class_attribute *attr,
 420                           char *buf)
 421 {
 422         /*
 423          * Inc this each time you change stats output format,
 424          * so user space will know what to do.
 425          */
 426         static int stats_version = 2;
 427         static const char * const state[] = {
 428                 "startup",
 429                 "running",
 430                 "reset",
 431                 "shutdown"
 432         };
 433         return sysfs_emit(buf, "%d %s %d %lu\n", stats_version,
 434                           state[server_conf.state], server_conf.tcp_port,
 435                           server_conf.ipc_last_active / HZ);
 436 }
 437
 438 static ssize_t kill_server_store(const struct class *class,
 439                                  const struct class_attribute *attr, const char *buf,
 440                                  size_t len)
 441 {
 442         if (!sysfs_streq(buf, "hard"))
 443                 return len;
 444
 445         pr_info("kill command received\n");
 446         mutex_lock(&ctrl_lock);
 447         WRITE_ONCE(server_conf.state, SERVER_STATE_RESETTING);
 448         __module_get(THIS_MODULE);
 449         server_ctrl_handle_reset(NULL);
 450         module_put(THIS_MODULE);
 451         mutex_unlock(&ctrl_lock);
 452         return len;
 453 }
 454
 455 static const char * const debug_type_strings[] = {"smb", "auth", "vfs",
 456                                                   "oplock", "ipc", "conn",
 457                                                   "rdma"};
 458
 459 static ssize_t debug_show(const struct class *class, const struct class_attribute *attr,
 460                           char *buf)
 461 {
 462         ssize_t sz = 0;
 463         int i, pos = 0;
 464
 465         for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
 466                 if ((ksmbd_debug_types >> i) & 1) {
 467                         pos = sysfs_emit_at(buf, sz, "[%s] ", debug_type_strings[i]);
 468                 } else {
 469                         pos = sysfs_emit_at(buf, sz, "%s ", debug_type_strings[i]);
 470                 }
 471                 sz += pos;
 472         }
 473         sz += sysfs_emit_at(buf, sz, "\n");
 474         return sz;
 475 }
 476
 477 static ssize_t debug_store(const struct class *class, const struct class_attribute *attr,
 478                            const char *buf, size_t len)
 479 {
 480         int i;
 481
 482         for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
 483                 if (sysfs_streq(buf, "all")) {
 484                         if (ksmbd_debug_types == KSMBD_DEBUG_ALL)
 485                                 ksmbd_debug_types = 0;
 486                         else
 487                                 ksmbd_debug_types = KSMBD_DEBUG_ALL;
 488                         break;
 489                 }
 490
 491                 if (sysfs_streq(buf, debug_type_strings[i])) {
 492                         if (ksmbd_debug_types & (1 << i))
 493                                 ksmbd_debug_types &= ~(1 << i);
 494                         else
 495                                 ksmbd_debug_types |= (1 << i);
 496                         break;
 497                 }
 498         }
 499
 500         return len;
 501 }
 502
 503 static CLASS_ATTR_RO(stats);
 504 static CLASS_ATTR_WO(kill_server);
 505 static CLASS_ATTR_RW(debug);
 506
 507 static struct attribute *ksmbd_control_class_attrs[] = {
 508         &class_attr_stats.attr,
 509         &class_attr_kill_server.attr,
 510         &class_attr_debug.attr,
 511         NULL,
 512 };
 513 ATTRIBUTE_GROUPS(ksmbd_control_class);
 514
 515 static struct class ksmbd_control_class = {
 516         .name           = "ksmbd-control",
 517         .class_groups   = ksmbd_control_class_groups,
 518 };
 519
 520 static int ksmbd_server_shutdown(void)
 521 {
 522         WRITE_ONCE(server_conf.state, SERVER_STATE_SHUTTING_DOWN);
 523
 524         class_unregister(&ksmbd_control_class);
 525         ksmbd_workqueue_destroy();
 526         ksmbd_ipc_release();
 527         ksmbd_conn_transport_destroy();
 528         ksmbd_crypto_destroy();
 529         ksmbd_free_global_file_table();
 530         destroy_lease_table(NULL);
 531         ksmbd_work_pool_destroy();
 532         ksmbd_exit_file_cache();
 533         server_conf_free();
 534         return 0;
 535 }
 536
 537 static int __init ksmbd_server_init(void)
 538 {
 539         int ret;
 540
 541         ret = class_register(&ksmbd_control_class);
 542         if (ret) {
 543                 pr_err("Unable to register ksmbd-control class\n");
 544                 return ret;
 545         }
 546
 547         ksmbd_server_tcp_callbacks_init();
 548
 549         ret = server_conf_init();
 550         if (ret)
 551                 goto err_unregister;
 552
 553         ret = ksmbd_work_pool_init();
 554         if (ret)
 555                 goto err_unregister;
 556
 557         ret = ksmbd_init_file_cache();
 558         if (ret)
 559                 goto err_destroy_work_pools;
 560
 561         ret = ksmbd_ipc_init();
 562         if (ret)
 563                 goto err_exit_file_cache;
 564
 565         ret = ksmbd_init_global_file_table();
 566         if (ret)
 567                 goto err_ipc_release;
 568
 569         ret = ksmbd_inode_hash_init();
 570         if (ret)
 571                 goto err_destroy_file_table;
 572
 573         ret = ksmbd_crypto_create();
 574         if (ret)
 575                 goto err_release_inode_hash;
 576
 577         ret = ksmbd_workqueue_init();
 578         if (ret)
 579                 goto err_crypto_destroy;
 580
 581         pr_warn_once("The ksmbd server is experimental\n");
 582
 583         return 0;
 584
 585 err_crypto_destroy:
 586         ksmbd_crypto_destroy();
 587 err_release_inode_hash:
 588         ksmbd_release_inode_hash();
 589 err_destroy_file_table:
 590         ksmbd_free_global_file_table();
 591 err_ipc_release:
 592         ksmbd_ipc_release();
 593 err_exit_file_cache:
 594         ksmbd_exit_file_cache();
 595 err_destroy_work_pools:
 596         ksmbd_work_pool_destroy();
 597 err_unregister:
 598         class_unregister(&ksmbd_control_class);
 599
 600         return ret;
 601 }
 602
 603 /**
 604  * ksmbd_server_exit() - shutdown forker thread and free memory at module exit
 605  */
 606 static void __exit ksmbd_server_exit(void)
 607 {
 608         ksmbd_server_shutdown();
 609         rcu_barrier();
 610         ksmbd_release_inode_hash();
 611 }
 612
 613 MODULE_AUTHOR("Namjae Jeon <linkinjeon@kernel.org>");
 614 MODULE_VERSION(KSMBD_VERSION);
 615 MODULE_DESCRIPTION("Linux kernel CIFS/SMB SERVER");
 616 MODULE_LICENSE("GPL");
 617 MODULE_SOFTDEP("pre: ecb");
 618 MODULE_SOFTDEP("pre: hmac");
 619 MODULE_SOFTDEP("pre: md5");
 620 MODULE_SOFTDEP("pre: nls");
 621 MODULE_SOFTDEP("pre: aes");
 622 MODULE_SOFTDEP("pre: cmac");
 623 MODULE_SOFTDEP("pre: sha256");
 624 MODULE_SOFTDEP("pre: sha512");
 625 MODULE_SOFTDEP("pre: aead2");
 626 MODULE_SOFTDEP("pre: ccm");
 627 MODULE_SOFTDEP("pre: gcm");
 628 MODULE_SOFTDEP("pre: crc32");
 629 module_init(ksmbd_server_init)
 630 module_exit(ksmbd_server_exit)