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