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         kvfree(conn->request_buf);
  40         kfree(conn->preauth_info);
  41         kfree(conn);
  42 }
  43
  44 /**
  45  * ksmbd_conn_alloc() - initialize a new connection instance
  46  *
  47  * Return:      ksmbd_conn struct on success, otherwise NULL
  48  */
  49 struct ksmbd_conn *ksmbd_conn_alloc(void)
  50 {
  51         struct ksmbd_conn *conn;
  52
  53         conn = kzalloc(sizeof(struct ksmbd_conn), GFP_KERNEL);
  54         if (!conn)
  55                 return NULL;
  56
  57         conn->need_neg = true;
  58         conn->status = KSMBD_SESS_NEW;
  59         conn->local_nls = load_nls("utf8");
  60         if (!conn->local_nls)
  61                 conn->local_nls = load_nls_default();
  62         atomic_set(&conn->req_running, 0);
  63         atomic_set(&conn->r_count, 0);
  64         init_waitqueue_head(&conn->req_running_q);
  65         INIT_LIST_HEAD(&conn->conns_list);
  66         INIT_LIST_HEAD(&conn->sessions);
  67         INIT_LIST_HEAD(&conn->requests);
  68         INIT_LIST_HEAD(&conn->async_requests);
  69         spin_lock_init(&conn->request_lock);
  70         spin_lock_init(&conn->credits_lock);
  71         ida_init(&conn->async_ida);
  72
  73         spin_lock_init(&conn->llist_lock);
  74         INIT_LIST_HEAD(&conn->lock_list);
  75
  76         write_lock(&conn_list_lock);
  77         list_add(&conn->conns_list, &conn_list);
  78         write_unlock(&conn_list_lock);
  79         return conn;
  80 }
  81
  82 bool ksmbd_conn_lookup_dialect(struct ksmbd_conn *c)
  83 {
  84         struct ksmbd_conn *t;
  85         bool ret = false;
  86
  87         read_lock(&conn_list_lock);
  88         list_for_each_entry(t, &conn_list, conns_list) {
  89                 if (memcmp(t->ClientGUID, c->ClientGUID, SMB2_CLIENT_GUID_SIZE))
  90                         continue;
  91
  92                 ret = true;
  93                 break;
  94         }
  95         read_unlock(&conn_list_lock);
  96         return ret;
  97 }
  98
  99 void ksmbd_conn_enqueue_request(struct ksmbd_work *work)
 100 {
 101         struct ksmbd_conn *conn = work->conn;
 102         struct list_head *requests_queue = NULL;
 103
 104         if (conn->ops->get_cmd_val(work) != SMB2_CANCEL_HE) {
 105                 requests_queue = &conn->requests;
 106                 work->syncronous = true;
 107         }
 108
 109         if (requests_queue) {
 110                 atomic_inc(&conn->req_running);
 111                 spin_lock(&conn->request_lock);
 112                 list_add_tail(&work->request_entry, requests_queue);
 113                 spin_unlock(&conn->request_lock);
 114         }
 115 }
 116
 117 int ksmbd_conn_try_dequeue_request(struct ksmbd_work *work)
 118 {
 119         struct ksmbd_conn *conn = work->conn;
 120         int ret = 1;
 121
 122         if (list_empty(&work->request_entry) &&
 123             list_empty(&work->async_request_entry))
 124                 return 0;
 125
 126         if (!work->multiRsp)
 127                 atomic_dec(&conn->req_running);
 128         spin_lock(&conn->request_lock);
 129         if (!work->multiRsp) {
 130                 list_del_init(&work->request_entry);
 131                 if (work->syncronous == false)
 132                         list_del_init(&work->async_request_entry);
 133                 ret = 0;
 134         }
 135         spin_unlock(&conn->request_lock);
 136
 137         wake_up_all(&conn->req_running_q);
 138         return ret;
 139 }
 140
 141 static void ksmbd_conn_lock(struct ksmbd_conn *conn)
 142 {
 143         mutex_lock(&conn->srv_mutex);
 144 }
 145
 146 static void ksmbd_conn_unlock(struct ksmbd_conn *conn)
 147 {
 148         mutex_unlock(&conn->srv_mutex);
 149 }
 150
 151 void ksmbd_conn_wait_idle(struct ksmbd_conn *conn)
 152 {
 153         wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
 154 }
 155
 156 int ksmbd_conn_write(struct ksmbd_work *work)
 157 {
 158         struct ksmbd_conn *conn = work->conn;
 159         struct smb_hdr *rsp_hdr = work->response_buf;
 160         size_t len = 0;
 161         int sent;
 162         struct kvec iov[3];
 163         int iov_idx = 0;
 164
 165         ksmbd_conn_try_dequeue_request(work);
 166         if (!rsp_hdr) {
 167                 pr_err("NULL response header\n");
 168                 return -EINVAL;
 169         }
 170
 171         if (work->tr_buf) {
 172                 iov[iov_idx] = (struct kvec) { work->tr_buf,
 173                                 sizeof(struct smb2_transform_hdr) };
 174                 len += iov[iov_idx++].iov_len;
 175         }
 176
 177         if (work->aux_payload_sz) {
 178                 iov[iov_idx] = (struct kvec) { rsp_hdr, work->resp_hdr_sz };
 179                 len += iov[iov_idx++].iov_len;
 180                 iov[iov_idx] = (struct kvec) { work->aux_payload_buf, work->aux_payload_sz };
 181                 len += iov[iov_idx++].iov_len;
 182         } else {
 183                 if (work->tr_buf)
 184                         iov[iov_idx].iov_len = work->resp_hdr_sz;
 185                 else
 186                         iov[iov_idx].iov_len = get_rfc1002_len(rsp_hdr) + 4;
 187                 iov[iov_idx].iov_base = rsp_hdr;
 188                 len += iov[iov_idx++].iov_len;
 189         }
 190
 191         ksmbd_conn_lock(conn);
 192         sent = conn->transport->ops->writev(conn->transport, &iov[0],
 193                                         iov_idx, len,
 194                                         work->need_invalidate_rkey,
 195                                         work->remote_key);
 196         ksmbd_conn_unlock(conn);
 197
 198         if (sent < 0) {
 199                 pr_err("Failed to send message: %d\n", sent);
 200                 return sent;
 201         }
 202
 203         return 0;
 204 }
 205
 206 int ksmbd_conn_rdma_read(struct ksmbd_conn *conn, void *buf,
 207                          unsigned int buflen, u32 remote_key, u64 remote_offset,
 208                          u32 remote_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                                                       remote_key, remote_offset,
 216                                                       remote_len);
 217         return ret;
 218 }
 219
 220 int ksmbd_conn_rdma_write(struct ksmbd_conn *conn, void *buf,
 221                           unsigned int buflen, u32 remote_key,
 222                           u64 remote_offset, u32 remote_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                                                        remote_key, remote_offset,
 230                                                        remote_len);
 231         return ret;
 232 }
 233
 234 bool ksmbd_conn_alive(struct ksmbd_conn *conn)
 235 {
 236         if (!ksmbd_server_running())
 237                 return false;
 238
 239         if (conn->status == KSMBD_SESS_EXITING)
 240                 return false;
 241
 242         if (kthread_should_stop())
 243                 return false;
 244
 245         if (atomic_read(&conn->stats.open_files_count) > 0)
 246                 return true;
 247
 248         /*
 249          * Stop current session if the time that get last request from client
 250          * is bigger than deadtime user configured and opening file count is
 251          * zero.
 252          */
 253         if (server_conf.deadtime > 0 &&
 254             time_after(jiffies, conn->last_active + server_conf.deadtime)) {
 255                 ksmbd_debug(CONN, "No response from client in %lu minutes\n",
 256                             server_conf.deadtime / SMB_ECHO_INTERVAL);
 257                 return false;
 258         }
 259         return true;
 260 }
 261
 262 /**
 263  * ksmbd_conn_handler_loop() - session thread to listen on new smb requests
 264  * @p:          connection instance
 265  *
 266  * One thread each per connection
 267  *
 268  * Return:      0 on success
 269  */
 270 int ksmbd_conn_handler_loop(void *p)
 271 {
 272         struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
 273         struct ksmbd_transport *t = conn->transport;
 274         unsigned int pdu_size;
 275         char hdr_buf[4] = {0,};
 276         int size;
 277
 278         mutex_init(&conn->srv_mutex);
 279         __module_get(THIS_MODULE);
 280
 281         if (t->ops->prepare && t->ops->prepare(t))
 282                 goto out;
 283
 284         conn->last_active = jiffies;
 285         while (ksmbd_conn_alive(conn)) {
 286                 if (try_to_freeze())
 287                         continue;
 288
 289                 kvfree(conn->request_buf);
 290                 conn->request_buf = NULL;
 291
 292                 size = t->ops->read(t, hdr_buf, sizeof(hdr_buf));
 293                 if (size != sizeof(hdr_buf))
 294                         break;
 295
 296                 pdu_size = get_rfc1002_len(hdr_buf);
 297                 ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
 298
 299                 /* make sure we have enough to get to SMB header end */
 300                 if (!ksmbd_pdu_size_has_room(pdu_size)) {
 301                         ksmbd_debug(CONN, "SMB request too short (%u bytes)\n",
 302                                     pdu_size);
 303                         continue;
 304                 }
 305
 306                 /* 4 for rfc1002 length field */
 307                 size = pdu_size + 4;
 308                 conn->request_buf = kvmalloc(size, GFP_KERNEL);
 309                 if (!conn->request_buf)
 310                         continue;
 311
 312                 memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
 313                 if (!ksmbd_smb_request(conn))
 314                         break;
 315
 316                 /*
 317                  * We already read 4 bytes to find out PDU size, now
 318                  * read in PDU
 319                  */
 320                 size = t->ops->read(t, conn->request_buf + 4, pdu_size);
 321                 if (size < 0) {
 322                         pr_err("sock_read failed: %d\n", size);
 323                         break;
 324                 }
 325
 326                 if (size != pdu_size) {
 327                         pr_err("PDU error. Read: %d, Expected: %d\n",
 328                                size, pdu_size);
 329                         continue;
 330                 }
 331
 332                 if (!default_conn_ops.process_fn) {
 333                         pr_err("No connection request callback\n");
 334                         break;
 335                 }
 336
 337                 if (default_conn_ops.process_fn(conn)) {
 338                         pr_err("Cannot handle request\n");
 339                         break;
 340                 }
 341         }
 342
 343 out:
 344         /* Wait till all reference dropped to the Server object*/
 345         while (atomic_read(&conn->r_count) > 0)
 346                 schedule_timeout(HZ);
 347
 348         unload_nls(conn->local_nls);
 349         if (default_conn_ops.terminate_fn)
 350                 default_conn_ops.terminate_fn(conn);
 351         t->ops->disconnect(t);
 352         module_put(THIS_MODULE);
 353         return 0;
 354 }
 355
 356 void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
 357 {
 358         default_conn_ops.process_fn = ops->process_fn;
 359         default_conn_ops.terminate_fn = ops->terminate_fn;
 360 }
 361
 362 int ksmbd_conn_transport_init(void)
 363 {
 364         int ret;
 365
 366         mutex_lock(&init_lock);
 367         ret = ksmbd_tcp_init();
 368         if (ret) {
 369                 pr_err("Failed to init TCP subsystem: %d\n", ret);
 370                 goto out;
 371         }
 372
 373         ret = ksmbd_rdma_init();
 374         if (ret) {
 375                 pr_err("Failed to init RDMA subsystem: %d\n", ret);
 376                 goto out;
 377         }
 378 out:
 379         mutex_unlock(&init_lock);
 380         return ret;
 381 }
 382
 383 static void stop_sessions(void)
 384 {
 385         struct ksmbd_conn *conn;
 386
 387 again:
 388         read_lock(&conn_list_lock);
 389         list_for_each_entry(conn, &conn_list, conns_list) {
 390                 struct task_struct *task;
 391
 392                 task = conn->transport->handler;
 393                 if (task)
 394                         ksmbd_debug(CONN, "Stop session handler %s/%d\n",
 395                                     task->comm, task_pid_nr(task));
 396                 conn->status = KSMBD_SESS_EXITING;
 397         }
 398         read_unlock(&conn_list_lock);
 399
 400         if (!list_empty(&conn_list)) {
 401                 schedule_timeout_interruptible(HZ / 10); /* 100ms */
 402                 goto again;
 403         }
 404 }
 405
 406 void ksmbd_conn_transport_destroy(void)
 407 {
 408         mutex_lock(&init_lock);
 409         ksmbd_tcp_destroy();
 410         ksmbd_rdma_destroy();
 411         stop_sessions();
 412         mutex_unlock(&init_lock);
 413 }