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 DEFINE_RWLOCK(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         write_lock(&conn_list_lock);
  36         list_del(&conn->conns_list);
  37         write_unlock(&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         conn->status = KSMBD_SESS_NEW;
  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         write_lock(&conn_list_lock);
  88         list_add(&conn->conns_list, &conn_list);
  89         write_unlock(&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         read_lock(&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         read_unlock(&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                 work->syncronous = true;
 118         }
 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 int ksmbd_conn_try_dequeue_request(struct ksmbd_work *work)
 129 {
 130         struct ksmbd_conn *conn = work->conn;
 131         int ret = 1;
 132
 133         if (list_empty(&work->request_entry) &&
 134             list_empty(&work->async_request_entry))
 135                 return 0;
 136
 137         if (!work->multiRsp)
 138                 atomic_dec(&conn->req_running);
 139         spin_lock(&conn->request_lock);
 140         if (!work->multiRsp) {
 141                 list_del_init(&work->request_entry);
 142                 if (work->syncronous == false)
 143                         list_del_init(&work->async_request_entry);
 144                 ret = 0;
 145         }
 146         spin_unlock(&conn->request_lock);
 147
 148         wake_up_all(&conn->req_running_q);
 149         return ret;
 150 }
 151
 152 static void ksmbd_conn_lock(struct ksmbd_conn *conn)
 153 {
 154         mutex_lock(&conn->srv_mutex);
 155 }
 156
 157 static void ksmbd_conn_unlock(struct ksmbd_conn *conn)
 158 {
 159         mutex_unlock(&conn->srv_mutex);
 160 }
 161
 162 void ksmbd_conn_wait_idle(struct ksmbd_conn *conn)
 163 {
 164         wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
 165 }
 166
 167 int ksmbd_conn_write(struct ksmbd_work *work)
 168 {
 169         struct ksmbd_conn *conn = work->conn;
 170         size_t len = 0;
 171         int sent;
 172         struct kvec iov[3];
 173         int iov_idx = 0;
 174
 175         if (!work->response_buf) {
 176                 pr_err("NULL response header\n");
 177                 return -EINVAL;
 178         }
 179
 180         if (work->tr_buf) {
 181                 iov[iov_idx] = (struct kvec) { work->tr_buf,
 182                                 sizeof(struct smb2_transform_hdr) + 4 };
 183                 len += iov[iov_idx++].iov_len;
 184         }
 185
 186         if (work->aux_payload_sz) {
 187                 iov[iov_idx] = (struct kvec) { work->response_buf, work->resp_hdr_sz };
 188                 len += iov[iov_idx++].iov_len;
 189                 iov[iov_idx] = (struct kvec) { work->aux_payload_buf, work->aux_payload_sz };
 190                 len += iov[iov_idx++].iov_len;
 191         } else {
 192                 if (work->tr_buf)
 193                         iov[iov_idx].iov_len = work->resp_hdr_sz;
 194                 else
 195                         iov[iov_idx].iov_len = get_rfc1002_len(work->response_buf) + 4;
 196                 iov[iov_idx].iov_base = work->response_buf;
 197                 len += iov[iov_idx++].iov_len;
 198         }
 199
 200         ksmbd_conn_lock(conn);
 201         sent = conn->transport->ops->writev(conn->transport, &iov[0],
 202                                         iov_idx, len,
 203                                         work->need_invalidate_rkey,
 204                                         work->remote_key);
 205         ksmbd_conn_unlock(conn);
 206
 207         if (sent < 0) {
 208                 pr_err("Failed to send message: %d\n", sent);
 209                 return sent;
 210         }
 211
 212         return 0;
 213 }
 214
 215 int ksmbd_conn_rdma_read(struct ksmbd_conn *conn,
 216                          void *buf, unsigned int buflen,
 217                          struct smb2_buffer_desc_v1 *desc,
 218                          unsigned int desc_len)
 219 {
 220         int ret = -EINVAL;
 221
 222         if (conn->transport->ops->rdma_read)
 223                 ret = conn->transport->ops->rdma_read(conn->transport,
 224                                                       buf, buflen,
 225                                                       desc, desc_len);
 226         return ret;
 227 }
 228
 229 int ksmbd_conn_rdma_write(struct ksmbd_conn *conn,
 230                           void *buf, unsigned int buflen,
 231                           struct smb2_buffer_desc_v1 *desc,
 232                           unsigned int desc_len)
 233 {
 234         int ret = -EINVAL;
 235
 236         if (conn->transport->ops->rdma_write)
 237                 ret = conn->transport->ops->rdma_write(conn->transport,
 238                                                        buf, buflen,
 239                                                        desc, desc_len);
 240         return ret;
 241 }
 242
 243 bool ksmbd_conn_alive(struct ksmbd_conn *conn)
 244 {
 245         if (!ksmbd_server_running())
 246                 return false;
 247
 248         if (conn->status == KSMBD_SESS_EXITING)
 249                 return false;
 250
 251         if (kthread_should_stop())
 252                 return false;
 253
 254         if (atomic_read(&conn->stats.open_files_count) > 0)
 255                 return true;
 256
 257         /*
 258          * Stop current session if the time that get last request from client
 259          * is bigger than deadtime user configured and opening file count is
 260          * zero.
 261          */
 262         if (server_conf.deadtime > 0 &&
 263             time_after(jiffies, conn->last_active + server_conf.deadtime)) {
 264                 ksmbd_debug(CONN, "No response from client in %lu minutes\n",
 265                             server_conf.deadtime / SMB_ECHO_INTERVAL);
 266                 return false;
 267         }
 268         return true;
 269 }
 270
 271 /**
 272  * ksmbd_conn_handler_loop() - session thread to listen on new smb requests
 273  * @p:          connection instance
 274  *
 275  * One thread each per connection
 276  *
 277  * Return:      0 on success
 278  */
 279 int ksmbd_conn_handler_loop(void *p)
 280 {
 281         struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
 282         struct ksmbd_transport *t = conn->transport;
 283         unsigned int pdu_size;
 284         char hdr_buf[4] = {0,};
 285         int size;
 286
 287         mutex_init(&conn->srv_mutex);
 288         __module_get(THIS_MODULE);
 289
 290         if (t->ops->prepare && t->ops->prepare(t))
 291                 goto out;
 292
 293         conn->last_active = jiffies;
 294         while (ksmbd_conn_alive(conn)) {
 295                 if (try_to_freeze())
 296                         continue;
 297
 298                 kvfree(conn->request_buf);
 299                 conn->request_buf = NULL;
 300
 301                 size = t->ops->read(t, hdr_buf, sizeof(hdr_buf));
 302                 if (size != sizeof(hdr_buf))
 303                         break;
 304
 305                 pdu_size = get_rfc1002_len(hdr_buf);
 306                 ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
 307
 308                 /*
 309                  * Check if pdu size is valid (min : smb header size,
 310                  * max : 0x00FFFFFF).
 311                  */
 312                 if (pdu_size < __SMB2_HEADER_STRUCTURE_SIZE ||
 313                     pdu_size > MAX_STREAM_PROT_LEN) {
 314                         continue;
 315                 }
 316
 317                 /* 4 for rfc1002 length field */
 318                 size = pdu_size + 4;
 319                 conn->request_buf = kvmalloc(size, GFP_KERNEL);
 320                 if (!conn->request_buf)
 321                         continue;
 322
 323                 memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
 324                 if (!ksmbd_smb_request(conn))
 325                         break;
 326
 327                 /*
 328                  * We already read 4 bytes to find out PDU size, now
 329                  * read in PDU
 330                  */
 331                 size = t->ops->read(t, conn->request_buf + 4, pdu_size);
 332                 if (size < 0) {
 333                         pr_err("sock_read failed: %d\n", size);
 334                         break;
 335                 }
 336
 337                 if (size != pdu_size) {
 338                         pr_err("PDU error. Read: %d, Expected: %d\n",
 339                                size, pdu_size);
 340                         continue;
 341                 }
 342
 343                 if (!default_conn_ops.process_fn) {
 344                         pr_err("No connection request callback\n");
 345                         break;
 346                 }
 347
 348                 if (default_conn_ops.process_fn(conn)) {
 349                         pr_err("Cannot handle request\n");
 350                         break;
 351                 }
 352         }
 353
 354 out:
 355         /* Wait till all reference dropped to the Server object*/
 356         wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);
 357
 358
 359         if (IS_ENABLED(CONFIG_UNICODE))
 360                 utf8_unload(conn->um);
 361         unload_nls(conn->local_nls);
 362         if (default_conn_ops.terminate_fn)
 363                 default_conn_ops.terminate_fn(conn);
 364         t->ops->disconnect(t);
 365         module_put(THIS_MODULE);
 366         return 0;
 367 }
 368
 369 void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
 370 {
 371         default_conn_ops.process_fn = ops->process_fn;
 372         default_conn_ops.terminate_fn = ops->terminate_fn;
 373 }
 374
 375 int ksmbd_conn_transport_init(void)
 376 {
 377         int ret;
 378
 379         mutex_lock(&init_lock);
 380         ret = ksmbd_tcp_init();
 381         if (ret) {
 382                 pr_err("Failed to init TCP subsystem: %d\n", ret);
 383                 goto out;
 384         }
 385
 386         ret = ksmbd_rdma_init();
 387         if (ret) {
 388                 pr_err("Failed to init RDMA subsystem: %d\n", ret);
 389                 goto out;
 390         }
 391 out:
 392         mutex_unlock(&init_lock);
 393         return ret;
 394 }
 395
 396 static void stop_sessions(void)
 397 {
 398         struct ksmbd_conn *conn;
 399         struct ksmbd_transport *t;
 400
 401 again:
 402         read_lock(&conn_list_lock);
 403         list_for_each_entry(conn, &conn_list, conns_list) {
 404                 struct task_struct *task;
 405
 406                 t = conn->transport;
 407                 task = t->handler;
 408                 if (task)
 409                         ksmbd_debug(CONN, "Stop session handler %s/%d\n",
 410                                     task->comm, task_pid_nr(task));
 411                 conn->status = KSMBD_SESS_EXITING;
 412                 if (t->ops->shutdown) {
 413                         read_unlock(&conn_list_lock);
 414                         t->ops->shutdown(t);
 415                         read_lock(&conn_list_lock);
 416                 }
 417         }
 418         read_unlock(&conn_list_lock);
 419
 420         if (!list_empty(&conn_list)) {
 421                 schedule_timeout_interruptible(HZ / 10); /* 100ms */
 422                 goto again;
 423         }
 424 }
 425
 426 void ksmbd_conn_transport_destroy(void)
 427 {
 428         mutex_lock(&init_lock);
 429         ksmbd_tcp_destroy();
 430         ksmbd_rdma_destroy();
 431         stop_sessions();
 432         mutex_unlock(&init_lock);
 433 }