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         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         if (IS_ENABLED(CONFIG_UNICODE))
  64                 conn->um = utf8_load(UNICODE_AGE(12, 1, 0));
  65         else
  66                 conn->um = ERR_PTR(-EOPNOTSUPP);
  67         if (IS_ERR(conn->um))
  68                 conn->um = NULL;
  69         atomic_set(&conn->req_running, 0);
  70         atomic_set(&conn->r_count, 0);
  71         conn->total_credits = 1;
  72         conn->outstanding_credits = 0;
  73
  74         init_waitqueue_head(&conn->req_running_q);
  75         init_waitqueue_head(&conn->r_count_q);
  76         INIT_LIST_HEAD(&conn->conns_list);
  77         INIT_LIST_HEAD(&conn->requests);
  78         INIT_LIST_HEAD(&conn->async_requests);
  79         spin_lock_init(&conn->request_lock);
  80         spin_lock_init(&conn->credits_lock);
  81         ida_init(&conn->async_ida);
  82         xa_init(&conn->sessions);
  83
  84         spin_lock_init(&conn->llist_lock);
  85         INIT_LIST_HEAD(&conn->lock_list);
  86
  87         write_lock(&conn_list_lock);
  88         list_add(&conn->conns_list, &conn_list);
  89         write_unlock(&conn_list_lock);
  90         return conn;
  91 }
  92
  93 bool ksmbd_conn_lookup_dialect(struct ksmbd_conn *c)
  94 {
  95         struct ksmbd_conn *t;
  96         bool ret = false;
  97
  98         read_lock(&conn_list_lock);
  99         list_for_each_entry(t, &conn_list, conns_list) {
 100                 if (memcmp(t->ClientGUID, c->ClientGUID, SMB2_CLIENT_GUID_SIZE))
 101                         continue;
 102
 103                 ret = true;
 104                 break;
 105         }
 106         read_unlock(&conn_list_lock);
 107         return ret;
 108 }
 109
 110 void ksmbd_conn_enqueue_request(struct ksmbd_work *work)
 111 {
 112         struct ksmbd_conn *conn = work->conn;
 113         struct list_head *requests_queue = NULL;
 114
 115         if (conn->ops->get_cmd_val(work) != SMB2_CANCEL_HE)
 116                 requests_queue = &conn->requests;
 117
 118         if (requests_queue) {
 119                 atomic_inc(&conn->req_running);
 120                 spin_lock(&conn->request_lock);
 121                 list_add_tail(&work->request_entry, requests_queue);
 122                 spin_unlock(&conn->request_lock);
 123         }
 124 }
 125
 126 int ksmbd_conn_try_dequeue_request(struct ksmbd_work *work)
 127 {
 128         struct ksmbd_conn *conn = work->conn;
 129         int ret = 1;
 130
 131         if (list_empty(&work->request_entry) &&
 132             list_empty(&work->async_request_entry))
 133                 return 0;
 134
 135         if (!work->multiRsp)
 136                 atomic_dec(&conn->req_running);
 137         if (!work->multiRsp) {
 138                 spin_lock(&conn->request_lock);
 139                 list_del_init(&work->request_entry);
 140                 spin_unlock(&conn->request_lock);
 141                 if (work->asynchronous)
 142                         release_async_work(work);
 143                 ret = 0;
 144         }
 145
 146         wake_up_all(&conn->req_running_q);
 147         return ret;
 148 }
 149
 150 static void ksmbd_conn_lock(struct ksmbd_conn *conn)
 151 {
 152         mutex_lock(&conn->srv_mutex);
 153 }
 154
 155 static void ksmbd_conn_unlock(struct ksmbd_conn *conn)
 156 {
 157         mutex_unlock(&conn->srv_mutex);
 158 }
 159
 160 void ksmbd_conn_wait_idle(struct ksmbd_conn *conn)
 161 {
 162         wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
 163 }
 164
 165 int ksmbd_conn_write(struct ksmbd_work *work)
 166 {
 167         struct ksmbd_conn *conn = work->conn;
 168         size_t len = 0;
 169         int sent;
 170         struct kvec iov[3];
 171         int iov_idx = 0;
 172
 173         if (!work->response_buf) {
 174                 pr_err("NULL response header\n");
 175                 return -EINVAL;
 176         }
 177
 178         if (work->tr_buf) {
 179                 iov[iov_idx] = (struct kvec) { work->tr_buf,
 180                                 sizeof(struct smb2_transform_hdr) + 4 };
 181                 len += iov[iov_idx++].iov_len;
 182         }
 183
 184         if (work->aux_payload_sz) {
 185                 iov[iov_idx] = (struct kvec) { work->response_buf, work->resp_hdr_sz };
 186                 len += iov[iov_idx++].iov_len;
 187                 iov[iov_idx] = (struct kvec) { work->aux_payload_buf, work->aux_payload_sz };
 188                 len += iov[iov_idx++].iov_len;
 189         } else {
 190                 if (work->tr_buf)
 191                         iov[iov_idx].iov_len = work->resp_hdr_sz;
 192                 else
 193                         iov[iov_idx].iov_len = get_rfc1002_len(work->response_buf) + 4;
 194                 iov[iov_idx].iov_base = work->response_buf;
 195                 len += iov[iov_idx++].iov_len;
 196         }
 197
 198         ksmbd_conn_lock(conn);
 199         sent = conn->transport->ops->writev(conn->transport, &iov[0],
 200                                         iov_idx, len,
 201                                         work->need_invalidate_rkey,
 202                                         work->remote_key);
 203         ksmbd_conn_unlock(conn);
 204
 205         if (sent < 0) {
 206                 pr_err("Failed to send message: %d\n", sent);
 207                 return sent;
 208         }
 209
 210         return 0;
 211 }
 212
 213 int ksmbd_conn_rdma_read(struct ksmbd_conn *conn,
 214                          void *buf, unsigned int buflen,
 215                          struct smb2_buffer_desc_v1 *desc,
 216                          unsigned int desc_len)
 217 {
 218         int ret = -EINVAL;
 219
 220         if (conn->transport->ops->rdma_read)
 221                 ret = conn->transport->ops->rdma_read(conn->transport,
 222                                                       buf, buflen,
 223                                                       desc, desc_len);
 224         return ret;
 225 }
 226
 227 int ksmbd_conn_rdma_write(struct ksmbd_conn *conn,
 228                           void *buf, unsigned int buflen,
 229                           struct smb2_buffer_desc_v1 *desc,
 230                           unsigned int desc_len)
 231 {
 232         int ret = -EINVAL;
 233
 234         if (conn->transport->ops->rdma_write)
 235                 ret = conn->transport->ops->rdma_write(conn->transport,
 236                                                        buf, buflen,
 237                                                        desc, desc_len);
 238         return ret;
 239 }
 240
 241 bool ksmbd_conn_alive(struct ksmbd_conn *conn)
 242 {
 243         if (!ksmbd_server_running())
 244                 return false;
 245
 246         if (conn->status == KSMBD_SESS_EXITING)
 247                 return false;
 248
 249         if (kthread_should_stop())
 250                 return false;
 251
 252         if (atomic_read(&conn->stats.open_files_count) > 0)
 253                 return true;
 254
 255         /*
 256          * Stop current session if the time that get last request from client
 257          * is bigger than deadtime user configured and opening file count is
 258          * zero.
 259          */
 260         if (server_conf.deadtime > 0 &&
 261             time_after(jiffies, conn->last_active + server_conf.deadtime)) {
 262                 ksmbd_debug(CONN, "No response from client in %lu minutes\n",
 263                             server_conf.deadtime / SMB_ECHO_INTERVAL);
 264                 return false;
 265         }
 266         return true;
 267 }
 268
 269 /**
 270  * ksmbd_conn_handler_loop() - session thread to listen on new smb requests
 271  * @p:          connection instance
 272  *
 273  * One thread each per connection
 274  *
 275  * Return:      0 on success
 276  */
 277 int ksmbd_conn_handler_loop(void *p)
 278 {
 279         struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
 280         struct ksmbd_transport *t = conn->transport;
 281         unsigned int pdu_size, max_allowed_pdu_size;
 282         char hdr_buf[4] = {0,};
 283         int size;
 284
 285         mutex_init(&conn->srv_mutex);
 286         __module_get(THIS_MODULE);
 287
 288         if (t->ops->prepare && t->ops->prepare(t))
 289                 goto out;
 290
 291         conn->last_active = jiffies;
 292         while (ksmbd_conn_alive(conn)) {
 293                 if (try_to_freeze())
 294                         continue;
 295
 296                 kvfree(conn->request_buf);
 297                 conn->request_buf = NULL;
 298
 299                 size = t->ops->read(t, hdr_buf, sizeof(hdr_buf), -1);
 300                 if (size != sizeof(hdr_buf))
 301                         break;
 302
 303                 pdu_size = get_rfc1002_len(hdr_buf);
 304                 ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
 305
 306                 if (conn->status == KSMBD_SESS_GOOD)
 307                         max_allowed_pdu_size =
 308                                 SMB3_MAX_MSGSIZE + conn->vals->max_write_size;
 309                 else
 310                         max_allowed_pdu_size = SMB3_MAX_MSGSIZE;
 311
 312                 if (pdu_size > max_allowed_pdu_size) {
 313                         pr_err_ratelimited("PDU length(%u) exceeded maximum allowed pdu size(%u) on connection(%d)\n",
 314                                         pdu_size, max_allowed_pdu_size,
 315                                         conn->status);
 316                         break;
 317                 }
 318
 319                 /*
 320                  * Check maximum pdu size(0x00FFFFFF).
 321                  */
 322                 if (pdu_size > MAX_STREAM_PROT_LEN)
 323                         break;
 324
 325                 /* 4 for rfc1002 length field */
 326                 size = pdu_size + 4;
 327                 conn->request_buf = kvmalloc(size, GFP_KERNEL);
 328                 if (!conn->request_buf)
 329                         break;
 330
 331                 memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
 332                 if (!ksmbd_smb_request(conn))
 333                         break;
 334
 335                 /*
 336                  * We already read 4 bytes to find out PDU size, now
 337                  * read in PDU
 338                  */
 339                 size = t->ops->read(t, conn->request_buf + 4, pdu_size, 2);
 340                 if (size < 0) {
 341                         pr_err("sock_read failed: %d\n", size);
 342                         break;
 343                 }
 344
 345                 if (size != pdu_size) {
 346                         pr_err("PDU error. Read: %d, Expected: %d\n",
 347                                size, pdu_size);
 348                         continue;
 349                 }
 350
 351                 if (!default_conn_ops.process_fn) {
 352                         pr_err("No connection request callback\n");
 353                         break;
 354                 }
 355
 356                 if (default_conn_ops.process_fn(conn)) {
 357                         pr_err("Cannot handle request\n");
 358                         break;
 359                 }
 360         }
 361
 362 out:
 363         /* Wait till all reference dropped to the Server object*/
 364         wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);
 365
 366
 367         if (IS_ENABLED(CONFIG_UNICODE))
 368                 utf8_unload(conn->um);
 369         unload_nls(conn->local_nls);
 370         if (default_conn_ops.terminate_fn)
 371                 default_conn_ops.terminate_fn(conn);
 372         t->ops->disconnect(t);
 373         module_put(THIS_MODULE);
 374         return 0;
 375 }
 376
 377 void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
 378 {
 379         default_conn_ops.process_fn = ops->process_fn;
 380         default_conn_ops.terminate_fn = ops->terminate_fn;
 381 }
 382
 383 int ksmbd_conn_transport_init(void)
 384 {
 385         int ret;
 386
 387         mutex_lock(&init_lock);
 388         ret = ksmbd_tcp_init();
 389         if (ret) {
 390                 pr_err("Failed to init TCP subsystem: %d\n", ret);
 391                 goto out;
 392         }
 393
 394         ret = ksmbd_rdma_init();
 395         if (ret) {
 396                 pr_err("Failed to init RDMA subsystem: %d\n", ret);
 397                 goto out;
 398         }
 399 out:
 400         mutex_unlock(&init_lock);
 401         return ret;
 402 }
 403
 404 static void stop_sessions(void)
 405 {
 406         struct ksmbd_conn *conn;
 407         struct ksmbd_transport *t;
 408
 409 again:
 410         read_lock(&conn_list_lock);
 411         list_for_each_entry(conn, &conn_list, conns_list) {
 412                 struct task_struct *task;
 413
 414                 t = conn->transport;
 415                 task = t->handler;
 416                 if (task)
 417                         ksmbd_debug(CONN, "Stop session handler %s/%d\n",
 418                                     task->comm, task_pid_nr(task));
 419                 conn->status = KSMBD_SESS_EXITING;
 420                 if (t->ops->shutdown) {
 421                         read_unlock(&conn_list_lock);
 422                         t->ops->shutdown(t);
 423                         read_lock(&conn_list_lock);
 424                 }
 425         }
 426         read_unlock(&conn_list_lock);
 427
 428         if (!list_empty(&conn_list)) {
 429                 schedule_timeout_interruptible(HZ / 10); /* 100ms */
 430                 goto again;
 431         }
 432 }
 433
 434 void ksmbd_conn_transport_destroy(void)
 435 {
 436         mutex_lock(&init_lock);
 437         ksmbd_tcp_destroy();
 438         ksmbd_rdma_destroy();
 439         stop_sessions();
 440         mutex_unlock(&init_lock);
 441 }