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         conn->outstanding_credits = 1;
  66
  67         init_waitqueue_head(&conn->req_running_q);
  68         INIT_LIST_HEAD(&conn->conns_list);
  69         INIT_LIST_HEAD(&conn->sessions);
  70         INIT_LIST_HEAD(&conn->requests);
  71         INIT_LIST_HEAD(&conn->async_requests);
  72         spin_lock_init(&conn->request_lock);
  73         spin_lock_init(&conn->credits_lock);
  74         ida_init(&conn->async_ida);
  75
  76         spin_lock_init(&conn->llist_lock);
  77         INIT_LIST_HEAD(&conn->lock_list);
  78
  79         write_lock(&conn_list_lock);
  80         list_add(&conn->conns_list, &conn_list);
  81         write_unlock(&conn_list_lock);
  82         return conn;
  83 }
  84
  85 bool ksmbd_conn_lookup_dialect(struct ksmbd_conn *c)
  86 {
  87         struct ksmbd_conn *t;
  88         bool ret = false;
  89
  90         read_lock(&conn_list_lock);
  91         list_for_each_entry(t, &conn_list, conns_list) {
  92                 if (memcmp(t->ClientGUID, c->ClientGUID, SMB2_CLIENT_GUID_SIZE))
  93                         continue;
  94
  95                 ret = true;
  96                 break;
  97         }
  98         read_unlock(&conn_list_lock);
  99         return ret;
 100 }
 101
 102 void ksmbd_conn_enqueue_request(struct ksmbd_work *work)
 103 {
 104         struct ksmbd_conn *conn = work->conn;
 105         struct list_head *requests_queue = NULL;
 106
 107         if (conn->ops->get_cmd_val(work) != SMB2_CANCEL_HE) {
 108                 requests_queue = &conn->requests;
 109                 work->syncronous = true;
 110         }
 111
 112         if (requests_queue) {
 113                 atomic_inc(&conn->req_running);
 114                 spin_lock(&conn->request_lock);
 115                 list_add_tail(&work->request_entry, requests_queue);
 116                 spin_unlock(&conn->request_lock);
 117         }
 118 }
 119
 120 int ksmbd_conn_try_dequeue_request(struct ksmbd_work *work)
 121 {
 122         struct ksmbd_conn *conn = work->conn;
 123         int ret = 1;
 124
 125         if (list_empty(&work->request_entry) &&
 126             list_empty(&work->async_request_entry))
 127                 return 0;
 128
 129         if (!work->multiRsp)
 130                 atomic_dec(&conn->req_running);
 131         spin_lock(&conn->request_lock);
 132         if (!work->multiRsp) {
 133                 list_del_init(&work->request_entry);
 134                 if (work->syncronous == false)
 135                         list_del_init(&work->async_request_entry);
 136                 ret = 0;
 137         }
 138         spin_unlock(&conn->request_lock);
 139
 140         wake_up_all(&conn->req_running_q);
 141         return ret;
 142 }
 143
 144 static void ksmbd_conn_lock(struct ksmbd_conn *conn)
 145 {
 146         mutex_lock(&conn->srv_mutex);
 147 }
 148
 149 static void ksmbd_conn_unlock(struct ksmbd_conn *conn)
 150 {
 151         mutex_unlock(&conn->srv_mutex);
 152 }
 153
 154 void ksmbd_conn_wait_idle(struct ksmbd_conn *conn)
 155 {
 156         wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
 157 }
 158
 159 int ksmbd_conn_write(struct ksmbd_work *work)
 160 {
 161         struct ksmbd_conn *conn = work->conn;
 162         size_t len = 0;
 163         int sent;
 164         struct kvec iov[3];
 165         int iov_idx = 0;
 166
 167         ksmbd_conn_try_dequeue_request(work);
 168         if (!work->response_buf) {
 169                 pr_err("NULL response header\n");
 170                 return -EINVAL;
 171         }
 172
 173         if (work->tr_buf) {
 174                 iov[iov_idx] = (struct kvec) { work->tr_buf,
 175                                 sizeof(struct smb2_transform_hdr) + 4 };
 176                 len += iov[iov_idx++].iov_len;
 177         }
 178
 179         if (work->aux_payload_sz) {
 180                 iov[iov_idx] = (struct kvec) { work->response_buf, work->resp_hdr_sz };
 181                 len += iov[iov_idx++].iov_len;
 182                 iov[iov_idx] = (struct kvec) { work->aux_payload_buf, work->aux_payload_sz };
 183                 len += iov[iov_idx++].iov_len;
 184         } else {
 185                 if (work->tr_buf)
 186                         iov[iov_idx].iov_len = work->resp_hdr_sz;
 187                 else
 188                         iov[iov_idx].iov_len = get_rfc1002_len(work->response_buf) + 4;
 189                 iov[iov_idx].iov_base = work->response_buf;
 190                 len += iov[iov_idx++].iov_len;
 191         }
 192
 193         ksmbd_conn_lock(conn);
 194         sent = conn->transport->ops->writev(conn->transport, &iov[0],
 195                                         iov_idx, len,
 196                                         work->need_invalidate_rkey,
 197                                         work->remote_key);
 198         ksmbd_conn_unlock(conn);
 199
 200         if (sent < 0) {
 201                 pr_err("Failed to send message: %d\n", sent);
 202                 return sent;
 203         }
 204
 205         return 0;
 206 }
 207
 208 int ksmbd_conn_rdma_read(struct ksmbd_conn *conn, void *buf,
 209                          unsigned int buflen, u32 remote_key, u64 remote_offset,
 210                          u32 remote_len)
 211 {
 212         int ret = -EINVAL;
 213
 214         if (conn->transport->ops->rdma_read)
 215                 ret = conn->transport->ops->rdma_read(conn->transport,
 216                                                       buf, buflen,
 217                                                       remote_key, remote_offset,
 218                                                       remote_len);
 219         return ret;
 220 }
 221
 222 int ksmbd_conn_rdma_write(struct ksmbd_conn *conn, void *buf,
 223                           unsigned int buflen, u32 remote_key,
 224                           u64 remote_offset, u32 remote_len)
 225 {
 226         int ret = -EINVAL;
 227
 228         if (conn->transport->ops->rdma_write)
 229                 ret = conn->transport->ops->rdma_write(conn->transport,
 230                                                        buf, buflen,
 231                                                        remote_key, remote_offset,
 232                                                        remote_len);
 233         return ret;
 234 }
 235
 236 bool ksmbd_conn_alive(struct ksmbd_conn *conn)
 237 {
 238         if (!ksmbd_server_running())
 239                 return false;
 240
 241         if (conn->status == KSMBD_SESS_EXITING)
 242                 return false;
 243
 244         if (kthread_should_stop())
 245                 return false;
 246
 247         if (atomic_read(&conn->stats.open_files_count) > 0)
 248                 return true;
 249
 250         /*
 251          * Stop current session if the time that get last request from client
 252          * is bigger than deadtime user configured and opening file count is
 253          * zero.
 254          */
 255         if (server_conf.deadtime > 0 &&
 256             time_after(jiffies, conn->last_active + server_conf.deadtime)) {
 257                 ksmbd_debug(CONN, "No response from client in %lu minutes\n",
 258                             server_conf.deadtime / SMB_ECHO_INTERVAL);
 259                 return false;
 260         }
 261         return true;
 262 }
 263
 264 /**
 265  * ksmbd_conn_handler_loop() - session thread to listen on new smb requests
 266  * @p:          connection instance
 267  *
 268  * One thread each per connection
 269  *
 270  * Return:      0 on success
 271  */
 272 int ksmbd_conn_handler_loop(void *p)
 273 {
 274         struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
 275         struct ksmbd_transport *t = conn->transport;
 276         unsigned int pdu_size;
 277         char hdr_buf[4] = {0,};
 278         int size;
 279
 280         mutex_init(&conn->srv_mutex);
 281         __module_get(THIS_MODULE);
 282
 283         if (t->ops->prepare && t->ops->prepare(t))
 284                 goto out;
 285
 286         conn->last_active = jiffies;
 287         while (ksmbd_conn_alive(conn)) {
 288                 if (try_to_freeze())
 289                         continue;
 290
 291                 kvfree(conn->request_buf);
 292                 conn->request_buf = NULL;
 293
 294                 size = t->ops->read(t, hdr_buf, sizeof(hdr_buf));
 295                 if (size != sizeof(hdr_buf))
 296                         break;
 297
 298                 pdu_size = get_rfc1002_len(hdr_buf);
 299                 ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
 300
 301                 /*
 302                  * Check if pdu size is valid (min : smb header size,
 303                  * max : 0x00FFFFFF).
 304                  */
 305                 if (pdu_size < __SMB2_HEADER_STRUCTURE_SIZE ||
 306                     pdu_size > MAX_STREAM_PROT_LEN) {
 307                         continue;
 308                 }
 309
 310                 /* 4 for rfc1002 length field */
 311                 size = pdu_size + 4;
 312                 conn->request_buf = kvmalloc(size, GFP_KERNEL);
 313                 if (!conn->request_buf)
 314                         continue;
 315
 316                 memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
 317                 if (!ksmbd_smb_request(conn))
 318                         break;
 319
 320                 /*
 321                  * We already read 4 bytes to find out PDU size, now
 322                  * read in PDU
 323                  */
 324                 size = t->ops->read(t, conn->request_buf + 4, pdu_size);
 325                 if (size < 0) {
 326                         pr_err("sock_read failed: %d\n", size);
 327                         break;
 328                 }
 329
 330                 if (size != pdu_size) {
 331                         pr_err("PDU error. Read: %d, Expected: %d\n",
 332                                size, pdu_size);
 333                         continue;
 334                 }
 335
 336                 if (!default_conn_ops.process_fn) {
 337                         pr_err("No connection request callback\n");
 338                         break;
 339                 }
 340
 341                 if (default_conn_ops.process_fn(conn)) {
 342                         pr_err("Cannot handle request\n");
 343                         break;
 344                 }
 345         }
 346
 347 out:
 348         /* Wait till all reference dropped to the Server object*/
 349         while (atomic_read(&conn->r_count) > 0)
 350                 schedule_timeout(HZ);
 351
 352         unload_nls(conn->local_nls);
 353         if (default_conn_ops.terminate_fn)
 354                 default_conn_ops.terminate_fn(conn);
 355         t->ops->disconnect(t);
 356         module_put(THIS_MODULE);
 357         return 0;
 358 }
 359
 360 void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
 361 {
 362         default_conn_ops.process_fn = ops->process_fn;
 363         default_conn_ops.terminate_fn = ops->terminate_fn;
 364 }
 365
 366 int ksmbd_conn_transport_init(void)
 367 {
 368         int ret;
 369
 370         mutex_lock(&init_lock);
 371         ret = ksmbd_tcp_init();
 372         if (ret) {
 373                 pr_err("Failed to init TCP subsystem: %d\n", ret);
 374                 goto out;
 375         }
 376
 377         ret = ksmbd_rdma_init();
 378         if (ret) {
 379                 pr_err("Failed to init RDMA subsystem: %d\n", ret);
 380                 goto out;
 381         }
 382 out:
 383         mutex_unlock(&init_lock);
 384         return ret;
 385 }
 386
 387 static void stop_sessions(void)
 388 {
 389         struct ksmbd_conn *conn;
 390         struct ksmbd_transport *t;
 391
 392 again:
 393         read_lock(&conn_list_lock);
 394         list_for_each_entry(conn, &conn_list, conns_list) {
 395                 struct task_struct *task;
 396
 397                 t = conn->transport;
 398                 task = t->handler;
 399                 if (task)
 400                         ksmbd_debug(CONN, "Stop session handler %s/%d\n",
 401                                     task->comm, task_pid_nr(task));
 402                 conn->status = KSMBD_SESS_EXITING;
 403                 if (t->ops->shutdown) {
 404                         read_unlock(&conn_list_lock);
 405                         t->ops->shutdown(t);
 406                         read_lock(&conn_list_lock);
 407                 }
 408         }
 409         read_unlock(&conn_list_lock);
 410
 411         if (!list_empty(&conn_list)) {
 412                 schedule_timeout_interruptible(HZ / 10); /* 100ms */
 413                 goto again;
 414         }
 415 }
 416
 417 void ksmbd_conn_transport_destroy(void)
 418 {
 419         mutex_lock(&init_lock);
 420         ksmbd_tcp_destroy();
 421         ksmbd_rdma_destroy();
 422         stop_sessions();
 423         mutex_unlock(&init_lock);
 424 }