fs/ksmbd/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 int ksmbd_conn_try_dequeue_request(struct ksmbd_work *work)
 127 {
 128         struct ksmbd_conn *conn = work->conn;
 129         int ret = 1;
 130
 131         if (list_empty(&work->request_entry) &&
 132             list_empty(&work->async_request_entry))
 133                 return 0;
 134
 135         if (!work->multiRsp)
 136                 atomic_dec(&conn->req_running);
 137         if (!work->multiRsp) {
 138                 spin_lock(&conn->request_lock);
 139                 list_del_init(&work->request_entry);
 140                 spin_unlock(&conn->request_lock);
 141                 if (work->asynchronous)
 142                         release_async_work(work);
 143                 ret = 0;
 144         }
 145
 146         wake_up_all(&conn->req_running_q);
 147         return ret;
 148 }
 149
 150 void ksmbd_conn_lock(struct ksmbd_conn *conn)
 151 {
 152         mutex_lock(&conn->srv_mutex);
 153 }
 154
 155 void ksmbd_conn_unlock(struct ksmbd_conn *conn)
 156 {
 157         mutex_unlock(&conn->srv_mutex);
 158 }
 159
 160 void ksmbd_all_conn_set_status(u64 sess_id, u32 status)
 161 {
 162         struct ksmbd_conn *conn;
 163
 164         down_read(&conn_list_lock);
 165         list_for_each_entry(conn, &conn_list, conns_list) {
 166                 if (conn->binding || xa_load(&conn->sessions, sess_id))
 167                         WRITE_ONCE(conn->status, status);
 168         }
 169         up_read(&conn_list_lock);
 170 }
 171
 172 void ksmbd_conn_wait_idle(struct ksmbd_conn *conn, u64 sess_id)
 173 {
 174         struct ksmbd_conn *bind_conn;
 175
 176         wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
 177
 178         down_read(&conn_list_lock);
 179         list_for_each_entry(bind_conn, &conn_list, conns_list) {
 180                 if (bind_conn == conn)
 181                         continue;
 182
 183                 if ((bind_conn->binding || xa_load(&bind_conn->sessions, sess_id)) &&
 184                     !ksmbd_conn_releasing(bind_conn) &&
 185                     atomic_read(&bind_conn->req_running)) {
 186                         wait_event(bind_conn->req_running_q,
 187                                 atomic_read(&bind_conn->req_running) == 0);
 188                 }
 189         }
 190         up_read(&conn_list_lock);
 191 }
 192
 193 int ksmbd_conn_write(struct ksmbd_work *work)
 194 {
 195         struct ksmbd_conn *conn = work->conn;
 196         size_t len = 0;
 197         int sent;
 198         struct kvec iov[3];
 199         int iov_idx = 0;
 200
 201         if (!work->response_buf) {
 202                 pr_err("NULL response header\n");
 203                 return -EINVAL;
 204         }
 205
 206         if (work->tr_buf) {
 207                 iov[iov_idx] = (struct kvec) { work->tr_buf,
 208                                 sizeof(struct smb2_transform_hdr) + 4 };
 209                 len += iov[iov_idx++].iov_len;
 210         }
 211
 212         if (work->aux_payload_sz) {
 213                 iov[iov_idx] = (struct kvec) { work->response_buf, work->resp_hdr_sz };
 214                 len += iov[iov_idx++].iov_len;
 215                 iov[iov_idx] = (struct kvec) { work->aux_payload_buf, work->aux_payload_sz };
 216                 len += iov[iov_idx++].iov_len;
 217         } else {
 218                 if (work->tr_buf)
 219                         iov[iov_idx].iov_len = work->resp_hdr_sz;
 220                 else
 221                         iov[iov_idx].iov_len = get_rfc1002_len(work->response_buf) + 4;
 222                 iov[iov_idx].iov_base = work->response_buf;
 223                 len += iov[iov_idx++].iov_len;
 224         }
 225
 226         ksmbd_conn_lock(conn);
 227         sent = conn->transport->ops->writev(conn->transport, &iov[0],
 228                                         iov_idx, len,
 229                                         work->need_invalidate_rkey,
 230                                         work->remote_key);
 231         ksmbd_conn_unlock(conn);
 232
 233         if (sent < 0) {
 234                 pr_err("Failed to send message: %d\n", sent);
 235                 return sent;
 236         }
 237
 238         return 0;
 239 }
 240
 241 int ksmbd_conn_rdma_read(struct ksmbd_conn *conn,
 242                          void *buf, unsigned int buflen,
 243                          struct smb2_buffer_desc_v1 *desc,
 244                          unsigned int desc_len)
 245 {
 246         int ret = -EINVAL;
 247
 248         if (conn->transport->ops->rdma_read)
 249                 ret = conn->transport->ops->rdma_read(conn->transport,
 250                                                       buf, buflen,
 251                                                       desc, desc_len);
 252         return ret;
 253 }
 254
 255 int ksmbd_conn_rdma_write(struct ksmbd_conn *conn,
 256                           void *buf, unsigned int buflen,
 257                           struct smb2_buffer_desc_v1 *desc,
 258                           unsigned int desc_len)
 259 {
 260         int ret = -EINVAL;
 261
 262         if (conn->transport->ops->rdma_write)
 263                 ret = conn->transport->ops->rdma_write(conn->transport,
 264                                                        buf, buflen,
 265                                                        desc, desc_len);
 266         return ret;
 267 }
 268
 269 bool ksmbd_conn_alive(struct ksmbd_conn *conn)
 270 {
 271         if (!ksmbd_server_running())
 272                 return false;
 273
 274         if (ksmbd_conn_exiting(conn))
 275                 return false;
 276
 277         if (kthread_should_stop())
 278                 return false;
 279
 280         if (atomic_read(&conn->stats.open_files_count) > 0)
 281                 return true;
 282
 283         /*
 284          * Stop current session if the time that get last request from client
 285          * is bigger than deadtime user configured and opening file count is
 286          * zero.
 287          */
 288         if (server_conf.deadtime > 0 &&
 289             time_after(jiffies, conn->last_active + server_conf.deadtime)) {
 290                 ksmbd_debug(CONN, "No response from client in %lu minutes\n",
 291                             server_conf.deadtime / SMB_ECHO_INTERVAL);
 292                 return false;
 293         }
 294         return true;
 295 }
 296
 297 /**
 298  * ksmbd_conn_handler_loop() - session thread to listen on new smb requests
 299  * @p:          connection instance
 300  *
 301  * One thread each per connection
 302  *
 303  * Return:      0 on success
 304  */
 305 int ksmbd_conn_handler_loop(void *p)
 306 {
 307         struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
 308         struct ksmbd_transport *t = conn->transport;
 309         unsigned int pdu_size, max_allowed_pdu_size;
 310         char hdr_buf[4] = {0,};
 311         int size;
 312
 313         mutex_init(&conn->srv_mutex);
 314         __module_get(THIS_MODULE);
 315
 316         if (t->ops->prepare && t->ops->prepare(t))
 317                 goto out;
 318
 319         conn->last_active = jiffies;
 320         while (ksmbd_conn_alive(conn)) {
 321                 if (try_to_freeze())
 322                         continue;
 323
 324                 kvfree(conn->request_buf);
 325                 conn->request_buf = NULL;
 326
 327                 size = t->ops->read(t, hdr_buf, sizeof(hdr_buf), -1);
 328                 if (size != sizeof(hdr_buf))
 329                         break;
 330
 331                 pdu_size = get_rfc1002_len(hdr_buf);
 332                 ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
 333
 334                 if (ksmbd_conn_good(conn))
 335                         max_allowed_pdu_size =
 336                                 SMB3_MAX_MSGSIZE + conn->vals->max_write_size;
 337                 else
 338                         max_allowed_pdu_size = SMB3_MAX_MSGSIZE;
 339
 340                 if (pdu_size > max_allowed_pdu_size) {
 341                         pr_err_ratelimited("PDU length(%u) exceeded maximum allowed pdu size(%u) on connection(%d)\n",
 342                                         pdu_size, max_allowed_pdu_size,
 343                                         READ_ONCE(conn->status));
 344                         break;
 345                 }
 346
 347                 /*
 348                  * Check maximum pdu size(0x00FFFFFF).
 349                  */
 350                 if (pdu_size > MAX_STREAM_PROT_LEN)
 351                         break;
 352
 353                 /* 4 for rfc1002 length field */
 354                 size = pdu_size + 4;
 355                 conn->request_buf = kvmalloc(size, GFP_KERNEL);
 356                 if (!conn->request_buf)
 357                         break;
 358
 359                 memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
 360                 if (!ksmbd_smb_request(conn))
 361                         break;
 362
 363                 /*
 364                  * We already read 4 bytes to find out PDU size, now
 365                  * read in PDU
 366                  */
 367                 size = t->ops->read(t, conn->request_buf + 4, pdu_size, 2);
 368                 if (size < 0) {
 369                         pr_err("sock_read failed: %d\n", size);
 370                         break;
 371                 }
 372
 373                 if (size != pdu_size) {
 374                         pr_err("PDU error. Read: %d, Expected: %d\n",
 375                                size, pdu_size);
 376                         continue;
 377                 }
 378
 379                 if (!default_conn_ops.process_fn) {
 380                         pr_err("No connection request callback\n");
 381                         break;
 382                 }
 383
 384                 if (default_conn_ops.process_fn(conn)) {
 385                         pr_err("Cannot handle request\n");
 386                         break;
 387                 }
 388         }
 389
 390 out:
 391         ksmbd_conn_set_releasing(conn);
 392         /* Wait till all reference dropped to the Server object*/
 393         wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);
 394
 395         if (IS_ENABLED(CONFIG_UNICODE))
 396                 utf8_unload(conn->um);
 397         unload_nls(conn->local_nls);
 398         if (default_conn_ops.terminate_fn)
 399                 default_conn_ops.terminate_fn(conn);
 400         t->ops->disconnect(t);
 401         module_put(THIS_MODULE);
 402         return 0;
 403 }
 404
 405 void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
 406 {
 407         default_conn_ops.process_fn = ops->process_fn;
 408         default_conn_ops.terminate_fn = ops->terminate_fn;
 409 }
 410
 411 int ksmbd_conn_transport_init(void)
 412 {
 413         int ret;
 414
 415         mutex_lock(&init_lock);
 416         ret = ksmbd_tcp_init();
 417         if (ret) {
 418                 pr_err("Failed to init TCP subsystem: %d\n", ret);
 419                 goto out;
 420         }
 421
 422         ret = ksmbd_rdma_init();
 423         if (ret) {
 424                 pr_err("Failed to init RDMA subsystem: %d\n", ret);
 425                 goto out;
 426         }
 427 out:
 428         mutex_unlock(&init_lock);
 429         return ret;
 430 }
 431
 432 static void stop_sessions(void)
 433 {
 434         struct ksmbd_conn *conn;
 435         struct ksmbd_transport *t;
 436
 437 again:
 438         down_read(&conn_list_lock);
 439         list_for_each_entry(conn, &conn_list, conns_list) {
 440                 struct task_struct *task;
 441
 442                 t = conn->transport;
 443                 task = t->handler;
 444                 if (task)
 445                         ksmbd_debug(CONN, "Stop session handler %s/%d\n",
 446                                     task->comm, task_pid_nr(task));
 447                 ksmbd_conn_set_exiting(conn);
 448                 if (t->ops->shutdown) {
 449                         up_read(&conn_list_lock);
 450                         t->ops->shutdown(t);
 451                         down_read(&conn_list_lock);
 452                 }
 453         }
 454         up_read(&conn_list_lock);
 455
 456         if (!list_empty(&conn_list)) {
 457                 schedule_timeout_interruptible(HZ / 10); /* 100ms */
 458                 goto again;
 459         }
 460 }
 461
 462 void ksmbd_conn_transport_destroy(void)
 463 {
 464         mutex_lock(&init_lock);
 465         ksmbd_tcp_destroy();
 466         ksmbd_rdma_destroy();
 467         stop_sessions();
 468         mutex_unlock(&init_lock);
 469 }