fs/ksmbd/connection.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *   Copyright (C) 2016 Namjae Jeon <[email protected]>
   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         atomic_set(&conn->req_running, 0);
  64         atomic_set(&conn->r_count, 0);
  65         conn->total_credits = 1;
  66         conn->outstanding_credits = 0;
  67
  68         init_waitqueue_head(&conn->req_running_q);
  69         init_waitqueue_head(&conn->r_count_q);
  70         INIT_LIST_HEAD(&conn->conns_list);
  71         INIT_LIST_HEAD(&conn->requests);
  72         INIT_LIST_HEAD(&conn->async_requests);
  73         spin_lock_init(&conn->request_lock);
  74         spin_lock_init(&conn->credits_lock);
  75         ida_init(&conn->async_ida);
  76         xa_init(&conn->sessions);
  77
  78         spin_lock_init(&conn->llist_lock);
  79         INIT_LIST_HEAD(&conn->lock_list);
  80
  81         write_lock(&conn_list_lock);
  82         list_add(&conn->conns_list, &conn_list);
  83         write_unlock(&conn_list_lock);
  84         return conn;
  85 }
  86
  87 bool ksmbd_conn_lookup_dialect(struct ksmbd_conn *c)
  88 {
  89         struct ksmbd_conn *t;
  90         bool ret = false;
  91
  92         read_lock(&conn_list_lock);
  93         list_for_each_entry(t, &conn_list, conns_list) {
  94                 if (memcmp(t->ClientGUID, c->ClientGUID, SMB2_CLIENT_GUID_SIZE))
  95                         continue;
  96
  97                 ret = true;
  98                 break;
  99         }
 100         read_unlock(&conn_list_lock);
 101         return ret;
 102 }
 103
 104 void ksmbd_conn_enqueue_request(struct ksmbd_work *work)
 105 {
 106         struct ksmbd_conn *conn = work->conn;
 107         struct list_head *requests_queue = NULL;
 108
 109         if (conn->ops->get_cmd_val(work) != SMB2_CANCEL_HE) {
 110                 requests_queue = &conn->requests;
 111                 work->syncronous = true;
 112         }
 113
 114         if (requests_queue) {
 115                 atomic_inc(&conn->req_running);
 116                 spin_lock(&conn->request_lock);
 117                 list_add_tail(&work->request_entry, requests_queue);
 118                 spin_unlock(&conn->request_lock);
 119         }
 120 }
 121
 122 int ksmbd_conn_try_dequeue_request(struct ksmbd_work *work)
 123 {
 124         struct ksmbd_conn *conn = work->conn;
 125         int ret = 1;
 126
 127         if (list_empty(&work->request_entry) &&
 128             list_empty(&work->async_request_entry))
 129                 return 0;
 130
 131         if (!work->multiRsp)
 132                 atomic_dec(&conn->req_running);
 133         spin_lock(&conn->request_lock);
 134         if (!work->multiRsp) {
 135                 list_del_init(&work->request_entry);
 136                 if (work->syncronous == false)
 137                         list_del_init(&work->async_request_entry);
 138                 ret = 0;
 139         }
 140         spin_unlock(&conn->request_lock);
 141
 142         wake_up_all(&conn->req_running_q);
 143         return ret;
 144 }
 145
 146 static void ksmbd_conn_lock(struct ksmbd_conn *conn)
 147 {
 148         mutex_lock(&conn->srv_mutex);
 149 }
 150
 151 static void ksmbd_conn_unlock(struct ksmbd_conn *conn)
 152 {
 153         mutex_unlock(&conn->srv_mutex);
 154 }
 155
 156 void ksmbd_conn_wait_idle(struct ksmbd_conn *conn)
 157 {
 158         wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
 159 }
 160
 161 int ksmbd_conn_write(struct ksmbd_work *work)
 162 {
 163         struct ksmbd_conn *conn = work->conn;
 164         size_t len = 0;
 165         int sent;
 166         struct kvec iov[3];
 167         int iov_idx = 0;
 168
 169         if (!work->response_buf) {
 170                 pr_err("NULL response header\n");
 171                 return -EINVAL;
 172         }
 173
 174         if (work->tr_buf) {
 175                 iov[iov_idx] = (struct kvec) { work->tr_buf,
 176                                 sizeof(struct smb2_transform_hdr) + 4 };
 177                 len += iov[iov_idx++].iov_len;
 178         }
 179
 180         if (work->aux_payload_sz) {
 181                 iov[iov_idx] = (struct kvec) { work->response_buf, work->resp_hdr_sz };
 182                 len += iov[iov_idx++].iov_len;
 183                 iov[iov_idx] = (struct kvec) { work->aux_payload_buf, work->aux_payload_sz };
 184                 len += iov[iov_idx++].iov_len;
 185         } else {
 186                 if (work->tr_buf)
 187                         iov[iov_idx].iov_len = work->resp_hdr_sz;
 188                 else
 189                         iov[iov_idx].iov_len = get_rfc1002_len(work->response_buf) + 4;
 190                 iov[iov_idx].iov_base = work->response_buf;
 191                 len += iov[iov_idx++].iov_len;
 192         }
 193
 194         ksmbd_conn_lock(conn);
 195         sent = conn->transport->ops->writev(conn->transport, &iov[0],
 196                                         iov_idx, len,
 197                                         work->need_invalidate_rkey,
 198                                         work->remote_key);
 199         ksmbd_conn_unlock(conn);
 200
 201         if (sent < 0) {
 202                 pr_err("Failed to send message: %d\n", sent);
 203                 return sent;
 204         }
 205
 206         return 0;
 207 }
 208
 209 int ksmbd_conn_rdma_read(struct ksmbd_conn *conn,
 210                          void *buf, unsigned int buflen,
 211                          struct smb2_buffer_desc_v1 *desc,
 212                          unsigned int desc_len)
 213 {
 214         int ret = -EINVAL;
 215
 216         if (conn->transport->ops->rdma_read)
 217                 ret = conn->transport->ops->rdma_read(conn->transport,
 218                                                       buf, buflen,
 219                                                       desc, desc_len);
 220         return ret;
 221 }
 222
 223 int ksmbd_conn_rdma_write(struct ksmbd_conn *conn,
 224                           void *buf, unsigned int buflen,
 225                           struct smb2_buffer_desc_v1 *desc,
 226                           unsigned int desc_len)
 227 {
 228         int ret = -EINVAL;
 229
 230         if (conn->transport->ops->rdma_write)
 231                 ret = conn->transport->ops->rdma_write(conn->transport,
 232                                                        buf, buflen,
 233                                                        desc, desc_len);
 234         return ret;
 235 }
 236
 237 bool ksmbd_conn_alive(struct ksmbd_conn *conn)
 238 {
 239         if (!ksmbd_server_running())
 240                 return false;
 241
 242         if (conn->status == KSMBD_SESS_EXITING)
 243                 return false;
 244
 245         if (kthread_should_stop())
 246                 return false;
 247
 248         if (atomic_read(&conn->stats.open_files_count) > 0)
 249                 return true;
 250
 251         /*
 252          * Stop current session if the time that get last request from client
 253          * is bigger than deadtime user configured and opening file count is
 254          * zero.
 255          */
 256         if (server_conf.deadtime > 0 &&
 257             time_after(jiffies, conn->last_active + server_conf.deadtime)) {
 258                 ksmbd_debug(CONN, "No response from client in %lu minutes\n",
 259                             server_conf.deadtime / SMB_ECHO_INTERVAL);
 260                 return false;
 261         }
 262         return true;
 263 }
 264
 265 /**
 266  * ksmbd_conn_handler_loop() - session thread to listen on new smb requests
 267  * @p:          connection instance
 268  *
 269  * One thread each per connection
 270  *
 271  * Return:      0 on success
 272  */
 273 int ksmbd_conn_handler_loop(void *p)
 274 {
 275         struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
 276         struct ksmbd_transport *t = conn->transport;
 277         unsigned int pdu_size;
 278         char hdr_buf[4] = {0,};
 279         int size;
 280
 281         mutex_init(&conn->srv_mutex);
 282         __module_get(THIS_MODULE);
 283
 284         if (t->ops->prepare && t->ops->prepare(t))
 285                 goto out;
 286
 287         conn->last_active = jiffies;
 288         while (ksmbd_conn_alive(conn)) {
 289                 if (try_to_freeze())
 290                         continue;
 291
 292                 kvfree(conn->request_buf);
 293                 conn->request_buf = NULL;
 294
 295                 size = t->ops->read(t, hdr_buf, sizeof(hdr_buf));
 296                 if (size != sizeof(hdr_buf))
 297                         break;
 298
 299                 pdu_size = get_rfc1002_len(hdr_buf);
 300                 ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
 301
 302                 /*
 303                  * Check if pdu size is valid (min : smb header size,
 304                  * max : 0x00FFFFFF).
 305                  */
 306                 if (pdu_size < __SMB2_HEADER_STRUCTURE_SIZE ||
 307                     pdu_size > MAX_STREAM_PROT_LEN) {
 308                         continue;
 309                 }
 310
 311                 /* 4 for rfc1002 length field */
 312                 size = pdu_size + 4;
 313                 conn->request_buf = kvmalloc(size, GFP_KERNEL);
 314                 if (!conn->request_buf)
 315                         continue;
 316
 317                 memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
 318                 if (!ksmbd_smb_request(conn))
 319                         break;
 320
 321                 /*
 322                  * We already read 4 bytes to find out PDU size, now
 323                  * read in PDU
 324                  */
 325                 size = t->ops->read(t, conn->request_buf + 4, pdu_size);
 326                 if (size < 0) {
 327                         pr_err("sock_read failed: %d\n", size);
 328                         break;
 329                 }
 330
 331                 if (size != pdu_size) {
 332                         pr_err("PDU error. Read: %d, Expected: %d\n",
 333                                size, pdu_size);
 334                         continue;
 335                 }
 336
 337                 if (!default_conn_ops.process_fn) {
 338                         pr_err("No connection request callback\n");
 339                         break;
 340                 }
 341
 342                 if (default_conn_ops.process_fn(conn)) {
 343                         pr_err("Cannot handle request\n");
 344                         break;
 345                 }
 346         }
 347
 348 out:
 349         /* Wait till all reference dropped to the Server object*/
 350         wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);
 351
 352
 353         unload_nls(conn->local_nls);
 354         if (default_conn_ops.terminate_fn)
 355                 default_conn_ops.terminate_fn(conn);
 356         t->ops->disconnect(t);
 357         module_put(THIS_MODULE);
 358         return 0;
 359 }
 360
 361 void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
 362 {
 363         default_conn_ops.process_fn = ops->process_fn;
 364         default_conn_ops.terminate_fn = ops->terminate_fn;
 365 }
 366
 367 int ksmbd_conn_transport_init(void)
 368 {
 369         int ret;
 370
 371         mutex_lock(&init_lock);
 372         ret = ksmbd_tcp_init();
 373         if (ret) {
 374                 pr_err("Failed to init TCP subsystem: %d\n", ret);
 375                 goto out;
 376         }
 377
 378         ret = ksmbd_rdma_init();
 379         if (ret) {
 380                 pr_err("Failed to init RDMA subsystem: %d\n", ret);
 381                 goto out;
 382         }
 383 out:
 384         mutex_unlock(&init_lock);
 385         return ret;
 386 }
 387
 388 static void stop_sessions(void)
 389 {
 390         struct ksmbd_conn *conn;
 391         struct ksmbd_transport *t;
 392
 393 again:
 394         read_lock(&conn_list_lock);
 395         list_for_each_entry(conn, &conn_list, conns_list) {
 396                 struct task_struct *task;
 397
 398                 t = conn->transport;
 399                 task = t->handler;
 400                 if (task)
 401                         ksmbd_debug(CONN, "Stop session handler %s/%d\n",
 402                                     task->comm, task_pid_nr(task));
 403                 conn->status = KSMBD_SESS_EXITING;
 404                 if (t->ops->shutdown) {
 405                         read_unlock(&conn_list_lock);
 406                         t->ops->shutdown(t);
 407                         read_lock(&conn_list_lock);
 408                 }
 409         }
 410         read_unlock(&conn_list_lock);
 411
 412         if (!list_empty(&conn_list)) {
 413                 schedule_timeout_interruptible(HZ / 10); /* 100ms */
 414                 goto again;
 415         }
 416 }
 417
 418 void ksmbd_conn_transport_destroy(void)
 419 {
 420         mutex_lock(&init_lock);
 421         ksmbd_tcp_destroy();
 422         ksmbd_rdma_destroy();
 423         stop_sessions();
 424         mutex_unlock(&init_lock);
 425 }