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         conn->total_credits = 1;
  65
  66         init_waitqueue_head(&conn->req_running_q);
  67         INIT_LIST_HEAD(&conn->conns_list);
  68         INIT_LIST_HEAD(&conn->sessions);
  69         INIT_LIST_HEAD(&conn->requests);
  70         INIT_LIST_HEAD(&conn->async_requests);
  71         spin_lock_init(&conn->request_lock);
  72         spin_lock_init(&conn->credits_lock);
  73         ida_init(&conn->async_ida);
  74
  75         spin_lock_init(&conn->llist_lock);
  76         INIT_LIST_HEAD(&conn->lock_list);
  77
  78         write_lock(&conn_list_lock);
  79         list_add(&conn->conns_list, &conn_list);
  80         write_unlock(&conn_list_lock);
  81         return conn;
  82 }
  83
  84 bool ksmbd_conn_lookup_dialect(struct ksmbd_conn *c)
  85 {
  86         struct ksmbd_conn *t;
  87         bool ret = false;
  88
  89         read_lock(&conn_list_lock);
  90         list_for_each_entry(t, &conn_list, conns_list) {
  91                 if (memcmp(t->ClientGUID, c->ClientGUID, SMB2_CLIENT_GUID_SIZE))
  92                         continue;
  93
  94                 ret = true;
  95                 break;
  96         }
  97         read_unlock(&conn_list_lock);
  98         return ret;
  99 }
 100
 101 void ksmbd_conn_enqueue_request(struct ksmbd_work *work)
 102 {
 103         struct ksmbd_conn *conn = work->conn;
 104         struct list_head *requests_queue = NULL;
 105
 106         if (conn->ops->get_cmd_val(work) != SMB2_CANCEL_HE) {
 107                 requests_queue = &conn->requests;
 108                 work->syncronous = true;
 109         }
 110
 111         if (requests_queue) {
 112                 atomic_inc(&conn->req_running);
 113                 spin_lock(&conn->request_lock);
 114                 list_add_tail(&work->request_entry, requests_queue);
 115                 spin_unlock(&conn->request_lock);
 116         }
 117 }
 118
 119 int ksmbd_conn_try_dequeue_request(struct ksmbd_work *work)
 120 {
 121         struct ksmbd_conn *conn = work->conn;
 122         int ret = 1;
 123
 124         if (list_empty(&work->request_entry) &&
 125             list_empty(&work->async_request_entry))
 126                 return 0;
 127
 128         if (!work->multiRsp)
 129                 atomic_dec(&conn->req_running);
 130         spin_lock(&conn->request_lock);
 131         if (!work->multiRsp) {
 132                 list_del_init(&work->request_entry);
 133                 if (work->syncronous == false)
 134                         list_del_init(&work->async_request_entry);
 135                 ret = 0;
 136         }
 137         spin_unlock(&conn->request_lock);
 138
 139         wake_up_all(&conn->req_running_q);
 140         return ret;
 141 }
 142
 143 static void ksmbd_conn_lock(struct ksmbd_conn *conn)
 144 {
 145         mutex_lock(&conn->srv_mutex);
 146 }
 147
 148 static void ksmbd_conn_unlock(struct ksmbd_conn *conn)
 149 {
 150         mutex_unlock(&conn->srv_mutex);
 151 }
 152
 153 void ksmbd_conn_wait_idle(struct ksmbd_conn *conn)
 154 {
 155         wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
 156 }
 157
 158 int ksmbd_conn_write(struct ksmbd_work *work)
 159 {
 160         struct ksmbd_conn *conn = work->conn;
 161         size_t len = 0;
 162         int sent;
 163         struct kvec iov[3];
 164         int iov_idx = 0;
 165
 166         ksmbd_conn_try_dequeue_request(work);
 167         if (!work->response_buf) {
 168                 pr_err("NULL response header\n");
 169                 return -EINVAL;
 170         }
 171
 172         if (work->tr_buf) {
 173                 iov[iov_idx] = (struct kvec) { work->tr_buf,
 174                                 sizeof(struct smb2_transform_hdr) + 4 };
 175                 len += iov[iov_idx++].iov_len;
 176         }
 177
 178         if (work->aux_payload_sz) {
 179                 iov[iov_idx] = (struct kvec) { work->response_buf, work->resp_hdr_sz };
 180                 len += iov[iov_idx++].iov_len;
 181                 iov[iov_idx] = (struct kvec) { work->aux_payload_buf, work->aux_payload_sz };
 182                 len += iov[iov_idx++].iov_len;
 183         } else {
 184                 if (work->tr_buf)
 185                         iov[iov_idx].iov_len = work->resp_hdr_sz;
 186                 else
 187                         iov[iov_idx].iov_len = get_rfc1002_len(work->response_buf) + 4;
 188                 iov[iov_idx].iov_base = work->response_buf;
 189                 len += iov[iov_idx++].iov_len;
 190         }
 191
 192         ksmbd_conn_lock(conn);
 193         sent = conn->transport->ops->writev(conn->transport, &iov[0],
 194                                         iov_idx, len,
 195                                         work->need_invalidate_rkey,
 196                                         work->remote_key);
 197         ksmbd_conn_unlock(conn);
 198
 199         if (sent < 0) {
 200                 pr_err("Failed to send message: %d\n", sent);
 201                 return sent;
 202         }
 203
 204         return 0;
 205 }
 206
 207 int ksmbd_conn_rdma_read(struct ksmbd_conn *conn, void *buf,
 208                          unsigned int buflen, u32 remote_key, u64 remote_offset,
 209                          u32 remote_len)
 210 {
 211         int ret = -EINVAL;
 212
 213         if (conn->transport->ops->rdma_read)
 214                 ret = conn->transport->ops->rdma_read(conn->transport,
 215                                                       buf, buflen,
 216                                                       remote_key, remote_offset,
 217                                                       remote_len);
 218         return ret;
 219 }
 220
 221 int ksmbd_conn_rdma_write(struct ksmbd_conn *conn, void *buf,
 222                           unsigned int buflen, u32 remote_key,
 223                           u64 remote_offset, u32 remote_len)
 224 {
 225         int ret = -EINVAL;
 226
 227         if (conn->transport->ops->rdma_write)
 228                 ret = conn->transport->ops->rdma_write(conn->transport,
 229                                                        buf, buflen,
 230                                                        remote_key, remote_offset,
 231                                                        remote_len);
 232         return ret;
 233 }
 234
 235 bool ksmbd_conn_alive(struct ksmbd_conn *conn)
 236 {
 237         if (!ksmbd_server_running())
 238                 return false;
 239
 240         if (conn->status == KSMBD_SESS_EXITING)
 241                 return false;
 242
 243         if (kthread_should_stop())
 244                 return false;
 245
 246         if (atomic_read(&conn->stats.open_files_count) > 0)
 247                 return true;
 248
 249         /*
 250          * Stop current session if the time that get last request from client
 251          * is bigger than deadtime user configured and opening file count is
 252          * zero.
 253          */
 254         if (server_conf.deadtime > 0 &&
 255             time_after(jiffies, conn->last_active + server_conf.deadtime)) {
 256                 ksmbd_debug(CONN, "No response from client in %lu minutes\n",
 257                             server_conf.deadtime / SMB_ECHO_INTERVAL);
 258                 return false;
 259         }
 260         return true;
 261 }
 262
 263 /**
 264  * ksmbd_conn_handler_loop() - session thread to listen on new smb requests
 265  * @p:          connection instance
 266  *
 267  * One thread each per connection
 268  *
 269  * Return:      0 on success
 270  */
 271 int ksmbd_conn_handler_loop(void *p)
 272 {
 273         struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
 274         struct ksmbd_transport *t = conn->transport;
 275         unsigned int pdu_size;
 276         char hdr_buf[4] = {0,};
 277         int size;
 278
 279         mutex_init(&conn->srv_mutex);
 280         __module_get(THIS_MODULE);
 281
 282         if (t->ops->prepare && t->ops->prepare(t))
 283                 goto out;
 284
 285         conn->last_active = jiffies;
 286         while (ksmbd_conn_alive(conn)) {
 287                 if (try_to_freeze())
 288                         continue;
 289
 290                 kvfree(conn->request_buf);
 291                 conn->request_buf = NULL;
 292
 293                 size = t->ops->read(t, hdr_buf, sizeof(hdr_buf));
 294                 if (size != sizeof(hdr_buf))
 295                         break;
 296
 297                 pdu_size = get_rfc1002_len(hdr_buf);
 298                 ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
 299
 300                 /*
 301                  * Check if pdu size is valid (min : smb header size,
 302                  * max : 0x00FFFFFF).
 303                  */
 304                 if (pdu_size < __SMB2_HEADER_STRUCTURE_SIZE ||
 305                     pdu_size > MAX_STREAM_PROT_LEN) {
 306                         continue;
 307                 }
 308
 309                 /* 4 for rfc1002 length field */
 310                 size = pdu_size + 4;
 311                 conn->request_buf = kvmalloc(size, GFP_KERNEL);
 312                 if (!conn->request_buf)
 313                         continue;
 314
 315                 memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
 316                 if (!ksmbd_smb_request(conn))
 317                         break;
 318
 319                 /*
 320                  * We already read 4 bytes to find out PDU size, now
 321                  * read in PDU
 322                  */
 323                 size = t->ops->read(t, conn->request_buf + 4, pdu_size);
 324                 if (size < 0) {
 325                         pr_err("sock_read failed: %d\n", size);
 326                         break;
 327                 }
 328
 329                 if (size != pdu_size) {
 330                         pr_err("PDU error. Read: %d, Expected: %d\n",
 331                                size, pdu_size);
 332                         continue;
 333                 }
 334
 335                 if (!default_conn_ops.process_fn) {
 336                         pr_err("No connection request callback\n");
 337                         break;
 338                 }
 339
 340                 if (default_conn_ops.process_fn(conn)) {
 341                         pr_err("Cannot handle request\n");
 342                         break;
 343                 }
 344         }
 345
 346 out:
 347         /* Wait till all reference dropped to the Server object*/
 348         while (atomic_read(&conn->r_count) > 0)
 349                 schedule_timeout(HZ);
 350
 351         unload_nls(conn->local_nls);
 352         if (default_conn_ops.terminate_fn)
 353                 default_conn_ops.terminate_fn(conn);
 354         t->ops->disconnect(t);
 355         module_put(THIS_MODULE);
 356         return 0;
 357 }
 358
 359 void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
 360 {
 361         default_conn_ops.process_fn = ops->process_fn;
 362         default_conn_ops.terminate_fn = ops->terminate_fn;
 363 }
 364
 365 int ksmbd_conn_transport_init(void)
 366 {
 367         int ret;
 368
 369         mutex_lock(&init_lock);
 370         ret = ksmbd_tcp_init();
 371         if (ret) {
 372                 pr_err("Failed to init TCP subsystem: %d\n", ret);
 373                 goto out;
 374         }
 375
 376         ret = ksmbd_rdma_init();
 377         if (ret) {
 378                 pr_err("Failed to init RDMA subsystem: %d\n", ret);
 379                 goto out;
 380         }
 381 out:
 382         mutex_unlock(&init_lock);
 383         return ret;
 384 }
 385
 386 static void stop_sessions(void)
 387 {
 388         struct ksmbd_conn *conn;
 389
 390 again:
 391         read_lock(&conn_list_lock);
 392         list_for_each_entry(conn, &conn_list, conns_list) {
 393                 struct task_struct *task;
 394
 395                 task = conn->transport->handler;
 396                 if (task)
 397                         ksmbd_debug(CONN, "Stop session handler %s/%d\n",
 398                                     task->comm, task_pid_nr(task));
 399                 conn->status = KSMBD_SESS_EXITING;
 400         }
 401         read_unlock(&conn_list_lock);
 402
 403         if (!list_empty(&conn_list)) {
 404                 schedule_timeout_interruptible(HZ / 10); /* 100ms */
 405                 goto again;
 406         }
 407 }
 408
 409 void ksmbd_conn_transport_destroy(void)
 410 {
 411         mutex_lock(&init_lock);
 412         ksmbd_tcp_destroy();
 413         ksmbd_rdma_destroy();
 414         stop_sessions();
 415         mutex_unlock(&init_lock);
 416 }