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