fs/cifsd/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 "buffer_pool.h"
  13 #include "smb_common.h"
  14 #include "mgmt/ksmbd_ida.h"
  15 #include "connection.h"
  16 #include "transport_tcp.h"
  17 #include "transport_rdma.h"
  18
  19 static DEFINE_MUTEX(init_lock);
  20
  21 static struct ksmbd_conn_ops default_conn_ops;
  22
  23 static LIST_HEAD(conn_list);
  24 static DEFINE_RWLOCK(conn_list_lock);
  25
  26 /**
  27  * ksmbd_conn_free() - free resources of the connection instance
  28  *
  29  * @conn:       connection instance to be cleand up
  30  *
  31  * During the thread termination, the corresponding conn instance
  32  * resources(sock/memory) are released and finally the conn object is freed.
  33  */
  34 void ksmbd_conn_free(struct ksmbd_conn *conn)
  35 {
  36         write_lock(&conn_list_lock);
  37         list_del(&conn->conns_list);
  38         write_unlock(&conn_list_lock);
  39
  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         atomic_set(&conn->req_running, 0);
  64         atomic_set(&conn->r_count, 0);
  65         init_waitqueue_head(&conn->req_running_q);
  66         INIT_LIST_HEAD(&conn->conns_list);
  67         INIT_LIST_HEAD(&conn->sessions);
  68         INIT_LIST_HEAD(&conn->requests);
  69         INIT_LIST_HEAD(&conn->async_requests);
  70         spin_lock_init(&conn->request_lock);
  71         spin_lock_init(&conn->credits_lock);
  72         ida_init(&conn->async_ida);
  73
  74         write_lock(&conn_list_lock);
  75         list_add(&conn->conns_list, &conn_list);
  76         write_unlock(&conn_list_lock);
  77         return conn;
  78 }
  79
  80 bool ksmbd_conn_lookup_dialect(struct ksmbd_conn *c)
  81 {
  82         struct ksmbd_conn *t;
  83         bool ret = false;
  84
  85         read_lock(&conn_list_lock);
  86         list_for_each_entry(t, &conn_list, conns_list) {
  87                 if (memcmp(t->ClientGUID, c->ClientGUID, SMB2_CLIENT_GUID_SIZE))
  88                         continue;
  89
  90                 ret = true;
  91                 break;
  92         }
  93         read_unlock(&conn_list_lock);
  94         return ret;
  95 }
  96
  97 void ksmbd_conn_enqueue_request(struct ksmbd_work *work)
  98 {
  99         struct ksmbd_conn *conn = work->conn;
 100         struct list_head *requests_queue = NULL;
 101
 102         if (conn->ops->get_cmd_val(work) != SMB2_CANCEL_HE) {
 103                 requests_queue = &conn->requests;
 104                 work->syncronous = true;
 105         }
 106
 107         if (requests_queue) {
 108                 atomic_inc(&conn->req_running);
 109                 spin_lock(&conn->request_lock);
 110                 list_add_tail(&work->request_entry, requests_queue);
 111                 spin_unlock(&conn->request_lock);
 112         }
 113 }
 114
 115 int ksmbd_conn_try_dequeue_request(struct ksmbd_work *work)
 116 {
 117         struct ksmbd_conn *conn = work->conn;
 118         int ret = 1;
 119
 120         if (list_empty(&work->request_entry) &&
 121             list_empty(&work->async_request_entry))
 122                 return 0;
 123
 124         atomic_dec(&conn->req_running);
 125         spin_lock(&conn->request_lock);
 126         if (!work->multiRsp) {
 127                 list_del_init(&work->request_entry);
 128                 if (work->syncronous == false)
 129                         list_del_init(&work->async_request_entry);
 130                 ret = 0;
 131         }
 132         spin_unlock(&conn->request_lock);
 133
 134         wake_up_all(&conn->req_running_q);
 135         return ret;
 136 }
 137
 138 static void ksmbd_conn_lock(struct ksmbd_conn *conn)
 139 {
 140         mutex_lock(&conn->srv_mutex);
 141 }
 142
 143 static void ksmbd_conn_unlock(struct ksmbd_conn *conn)
 144 {
 145         mutex_unlock(&conn->srv_mutex);
 146 }
 147
 148 void ksmbd_conn_wait_idle(struct ksmbd_conn *conn)
 149 {
 150         wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
 151 }
 152
 153 int ksmbd_conn_write(struct ksmbd_work *work)
 154 {
 155         struct ksmbd_conn *conn = work->conn;
 156         struct smb_hdr *rsp_hdr = work->response_buf;
 157         size_t len = 0;
 158         int sent;
 159         struct kvec iov[3];
 160         int iov_idx = 0;
 161
 162         ksmbd_conn_try_dequeue_request(work);
 163         if (!rsp_hdr) {
 164                 ksmbd_err("NULL response header\n");
 165                 return -EINVAL;
 166         }
 167
 168         if (work->tr_buf) {
 169                 iov[iov_idx] = (struct kvec) { work->tr_buf,
 170                                 sizeof(struct smb2_transform_hdr) };
 171                 len += iov[iov_idx++].iov_len;
 172         }
 173
 174         if (work->aux_payload_sz) {
 175                 iov[iov_idx] = (struct kvec) { rsp_hdr, work->resp_hdr_sz };
 176                 len += iov[iov_idx++].iov_len;
 177                 iov[iov_idx] = (struct kvec) { work->aux_payload_buf, work->aux_payload_sz };
 178                 len += iov[iov_idx++].iov_len;
 179         } else {
 180                 if (work->tr_buf)
 181                         iov[iov_idx].iov_len = work->resp_hdr_sz;
 182                 else
 183                         iov[iov_idx].iov_len = get_rfc1002_len(rsp_hdr) + 4;
 184                 iov[iov_idx].iov_base = rsp_hdr;
 185                 len += iov[iov_idx++].iov_len;
 186         }
 187
 188         ksmbd_conn_lock(conn);
 189         sent = conn->transport->ops->writev(conn->transport, &iov[0],
 190                                         iov_idx, len,
 191                                         work->need_invalidate_rkey,
 192                                         work->remote_key);
 193         ksmbd_conn_unlock(conn);
 194
 195         if (sent < 0) {
 196                 ksmbd_err("Failed to send message: %d\n", sent);
 197                 return sent;
 198         }
 199
 200         return 0;
 201 }
 202
 203 int ksmbd_conn_rdma_read(struct ksmbd_conn *conn, void *buf,
 204                 unsigned int buflen, u32 remote_key, u64 remote_offset,
 205                 u32 remote_len)
 206 {
 207         int ret = -EINVAL;
 208
 209         if (conn->transport->ops->rdma_read)
 210                 ret = conn->transport->ops->rdma_read(conn->transport,
 211                                                 buf, buflen,
 212                                                 remote_key, remote_offset,
 213                                                 remote_len);
 214         return ret;
 215 }
 216
 217 int ksmbd_conn_rdma_write(struct ksmbd_conn *conn, void *buf,
 218                 unsigned int buflen, u32 remote_key, u64 remote_offset,
 219                 u32 remote_len)
 220 {
 221         int ret = -EINVAL;
 222
 223         if (conn->transport->ops->rdma_write)
 224                 ret = conn->transport->ops->rdma_write(conn->transport,
 225                                                 buf, buflen,
 226                                                 remote_key, remote_offset,
 227                                                 remote_len);
 228         return ret;
 229 }
 230
 231 bool ksmbd_conn_alive(struct ksmbd_conn *conn)
 232 {
 233         if (!ksmbd_server_running())
 234                 return false;
 235
 236         if (conn->status == KSMBD_SESS_EXITING)
 237                 return false;
 238
 239         if (kthread_should_stop())
 240                 return false;
 241
 242         if (atomic_read(&conn->stats.open_files_count) > 0)
 243                 return true;
 244
 245         /*
 246          * Stop current session if the time that get last request from client
 247          * is bigger than deadtime user configured and openning file count is
 248          * zero.
 249          */
 250         if (server_conf.deadtime > 0 &&
 251             time_after(jiffies, conn->last_active + server_conf.deadtime)) {
 252                 ksmbd_debug(CONN, "No response from client in %lu minutes\n",
 253                         server_conf.deadtime / SMB_ECHO_INTERVAL);
 254                 return false;
 255         }
 256         return true;
 257 }
 258
 259 /**
 260  * ksmbd_conn_handler_loop() - session thread to listen on new smb requests
 261  * @p:          connection instance
 262  *
 263  * One thread each per connection
 264  *
 265  * Return:      0 on success
 266  */
 267 int ksmbd_conn_handler_loop(void *p)
 268 {
 269         struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
 270         struct ksmbd_transport *t = conn->transport;
 271         unsigned int pdu_size;
 272         char hdr_buf[4] = {0,};
 273         int size;
 274
 275         mutex_init(&conn->srv_mutex);
 276         __module_get(THIS_MODULE);
 277
 278         if (t->ops->prepare && t->ops->prepare(t))
 279                 goto out;
 280
 281         conn->last_active = jiffies;
 282         while (ksmbd_conn_alive(conn)) {
 283                 if (try_to_freeze())
 284                         continue;
 285
 286                 kvfree(conn->request_buf);
 287                 conn->request_buf = NULL;
 288
 289                 size = t->ops->read(t, hdr_buf, sizeof(hdr_buf));
 290                 if (size != sizeof(hdr_buf))
 291                         break;
 292
 293                 pdu_size = get_rfc1002_len(hdr_buf);
 294                 ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
 295
 296                 /* make sure we have enough to get to SMB header end */
 297                 if (!ksmbd_pdu_size_has_room(pdu_size)) {
 298                         ksmbd_debug(CONN, "SMB request too short (%u bytes)\n",
 299                                     pdu_size);
 300                         continue;
 301                 }
 302
 303                 /* 4 for rfc1002 length field */
 304                 size = pdu_size + 4;
 305                 conn->request_buf = kvmalloc(size, GFP_KERNEL);
 306                 if (!conn->request_buf)
 307                         continue;
 308
 309                 memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
 310                 if (!ksmbd_smb_request(conn))
 311                         break;
 312
 313                 /*
 314                  * We already read 4 bytes to find out PDU size, now
 315                  * read in PDU
 316                  */
 317                 size = t->ops->read(t, conn->request_buf + 4, pdu_size);
 318                 if (size < 0) {
 319                         ksmbd_err("sock_read failed: %d\n", size);
 320                         break;
 321                 }
 322
 323                 if (size != pdu_size) {
 324                         ksmbd_err("PDU error. Read: %d, Expected: %d\n",
 325                                   size,
 326                                   pdu_size);
 327                         continue;
 328                 }
 329
 330                 if (!default_conn_ops.process_fn) {
 331                         ksmbd_err("No connection request callback\n");
 332                         break;
 333                 }
 334
 335                 if (default_conn_ops.process_fn(conn)) {
 336                         ksmbd_err("Cannot handle request\n");
 337                         break;
 338                 }
 339         }
 340
 341 out:
 342         /* Wait till all reference dropped to the Server object*/
 343         while (atomic_read(&conn->r_count) > 0)
 344                 schedule_timeout(HZ);
 345
 346         unload_nls(conn->local_nls);
 347         if (default_conn_ops.terminate_fn)
 348                 default_conn_ops.terminate_fn(conn);
 349         t->ops->disconnect(t);
 350         module_put(THIS_MODULE);
 351         return 0;
 352 }
 353
 354 void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
 355 {
 356         default_conn_ops.process_fn = ops->process_fn;
 357         default_conn_ops.terminate_fn = ops->terminate_fn;
 358 }
 359
 360 int ksmbd_conn_transport_init(void)
 361 {
 362         int ret;
 363
 364         mutex_lock(&init_lock);
 365         ret = ksmbd_tcp_init();
 366         if (ret) {
 367                 pr_err("Failed to init TCP subsystem: %d\n", ret);
 368                 goto out;
 369         }
 370
 371         ret = ksmbd_rdma_init();
 372         if (ret) {
 373                 pr_err("Failed to init KSMBD subsystem: %d\n", ret);
 374                 goto out;
 375         }
 376 out:
 377         mutex_unlock(&init_lock);
 378         return ret;
 379 }
 380
 381 static void stop_sessions(void)
 382 {
 383         struct ksmbd_conn *conn;
 384
 385 again:
 386         read_lock(&conn_list_lock);
 387         list_for_each_entry(conn, &conn_list, conns_list) {
 388                 struct task_struct *task;
 389
 390                 task = conn->transport->handler;
 391                 if (task)
 392                         ksmbd_debug(CONN, "Stop session handler %s/%d\n",
 393                                   task->comm, task_pid_nr(task));
 394                 conn->status = KSMBD_SESS_EXITING;
 395         }
 396         read_unlock(&conn_list_lock);
 397
 398         if (!list_empty(&conn_list)) {
 399                 schedule_timeout_interruptible(HZ / 10); /* 100ms */
 400                 goto again;
 401         }
 402 }
 403
 404 void ksmbd_conn_transport_destroy(void)
 405 {
 406         mutex_lock(&init_lock);
 407         ksmbd_tcp_destroy();
 408         ksmbd_rdma_destroy();
 409         stop_sessions();
 410         mutex_unlock(&init_lock);
 411 }