resource/csdk/connectivity/src/tcp_adapter/catcpserver.c

   1 /* ****************************************************************
   2  *
   3  * Copyright 2015 Samsung Electronics All Rights Reserved.
   4  *
   5  *
   6  *
   7  * Licensed under the Apache License, Version 2.0 (the "License");
   8  * you may not use this file except in compliance with the License.
   9  * You may obtain a copy of the License at
  10  *
  11  *      http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  *
  19  ******************************************************************/
  20
  21 #include <sys/types.h>
  22 #include <sys/socket.h>
  23 #include <sys/ioctl.h>
  24 #include <stdio.h>
  25 #include <unistd.h>
  26 #include <sys/types.h>
  27 #include <fcntl.h>
  28 #include <sys/select.h>
  29 #include <arpa/inet.h>
  30 #include <netinet/in.h>
  31 #include <net/if.h>
  32 #include <errno.h>
  33 #include <sys/poll.h>
  34
  35 #ifndef WITH_ARDUINO
  36 #include <sys/socket.h>
  37 #include <netinet/in.h>
  38 #include <netdb.h>
  39 #endif
  40
  41 #include "catcpinterface.h"
  42 #include "pdu.h"
  43 #include "caadapterutils.h"
  44 #include "camutex.h"
  45 #include "oic_malloc.h"
  46 #include "oic_string.h"
  47
  48 /**
  49  * Logging tag for module name.
  50  */
  51 #define TAG "OIC_CA_TCP_SERVER"
  52
  53 /**
  54  * Server port number for local test.
  55  */
  56 #define SERVER_PORT 8000
  57
  58 /**
  59  * Maximum CoAP over TCP header length
  60  * to know the total data length.
  61  */
  62 #define TCP_MAX_HEADER_LEN  6
  63
  64 /**
  65  * Accept server file descriptor.
  66  */
  67 static int g_acceptServerFD = -1;
  68
  69 /**
  70  * Mutex to synchronize device object list.
  71  */
  72 static ca_mutex g_mutexObjectList = NULL;
  73
  74 /**
  75  * Conditional mutex to synchronize.
  76  */
  77 static ca_cond g_condObjectList = NULL;
  78
  79 /**
  80  * Maintains the callback to be notified when data received from remote device.
  81  */
  82 static CATCPPacketReceivedCallback g_packetReceivedCallback;
  83
  84 /**
  85  * Error callback to update error in TCP.
  86  */
  87 static CATCPErrorHandleCallback g_TCPErrorHandler = NULL;
  88
  89 /**
  90  * Connected Callback to pass the connection information to RI.
  91  */
  92 static CATCPKeepAliveHandleCallback g_keepaliveCallback = NULL;
  93
  94 static CAResult_t CATCPCreateMutex();
  95 static void CATCPDestroyMutex();
  96 static CAResult_t CATCPCreateCond();
  97 static void CATCPDestroyCond();
  98 static CAResult_t CACreateAcceptSocket();
  99 static void CAAcceptConnection();
 100 static void CAFindReadyMessage();
 101 static void CASelectReturned(fd_set *readFds, int ret);
 102 static void CAReceiveMessage(int fd);
 103 static void CAReceiveHandler(void *data);
 104 static int CATCPCreateSocket(int family, CATCPSessionInfo_t *tcpServerInfo);
 105
 106 #define CHECKFD(FD) \
 107     if (FD > caglobals.tcp.maxfd) \
 108         caglobals.tcp.maxfd = FD;
 109
 110 static void CATCPDestroyMutex()
 111 {
 112     if (g_mutexObjectList)
 113     {
 114         ca_mutex_free(g_mutexObjectList);
 115         g_mutexObjectList = NULL;
 116     }
 117 }
 118
 119 static CAResult_t CATCPCreateMutex()
 120 {
 121     if (!g_mutexObjectList)
 122     {
 123         g_mutexObjectList = ca_mutex_new();
 124         if (!g_mutexObjectList)
 125         {
 126             OIC_LOG(ERROR, TAG, "Failed to created mutex!");
 127             return CA_STATUS_FAILED;
 128         }
 129     }
 130
 131     return CA_STATUS_OK;
 132 }
 133
 134 static void CATCPDestroyCond()
 135 {
 136     if (g_condObjectList)
 137     {
 138         ca_cond_free(g_condObjectList);
 139         g_condObjectList = NULL;
 140     }
 141 }
 142
 143 static CAResult_t CATCPCreateCond()
 144 {
 145     if (!g_condObjectList)
 146     {
 147         g_condObjectList = ca_cond_new();
 148         if (!g_condObjectList)
 149         {
 150             OIC_LOG(ERROR, TAG, "Failed to created cond!");
 151             return CA_STATUS_FAILED;
 152         }
 153     }
 154     return CA_STATUS_OK;
 155 }
 156
 157 static void CAReceiveHandler(void *data)
 158 {
 159     (void)data;
 160     OIC_LOG(DEBUG, TAG, "IN - CAReceiveHandler");
 161
 162     while (!caglobals.tcp.terminate)
 163     {
 164         CAFindReadyMessage();
 165     }
 166
 167     ca_mutex_lock(g_mutexObjectList);
 168     ca_cond_signal(g_condObjectList);
 169     ca_mutex_unlock(g_mutexObjectList);
 170
 171     OIC_LOG(DEBUG, TAG, "OUT - CAReceiveHandler");
 172 }
 173
 174 static void CAFindReadyMessage()
 175 {
 176     fd_set readFds;
 177     struct timeval timeout = { .tv_sec = caglobals.tcp.selectTimeout };
 178
 179     FD_ZERO(&readFds);
 180
 181     if (-1 != g_acceptServerFD)
 182     {
 183         FD_SET(g_acceptServerFD, &readFds);
 184     }
 185     if (-1 != caglobals.tcp.shutdownFds[0])
 186     {
 187         FD_SET(caglobals.tcp.shutdownFds[0], &readFds);
 188     }
 189     if (-1 != caglobals.tcp.connectionFds[0])
 190     {
 191         FD_SET(caglobals.tcp.connectionFds[0], &readFds);
 192     }
 193
 194     uint32_t length = u_arraylist_length(caglobals.tcp.svrlist);
 195     for (size_t i = 0; i < length; i++)
 196     {
 197         CATCPSessionInfo_t *svritem =
 198                 (CATCPSessionInfo_t *) u_arraylist_get(caglobals.tcp.svrlist, i);
 199         if (svritem && 0 <= svritem->fd)
 200         {
 201             FD_SET(svritem->fd, &readFds);
 202         }
 203     }
 204
 205     int ret = select(caglobals.tcp.maxfd + 1, &readFds, NULL, NULL, &timeout);
 206
 207     if (caglobals.tcp.terminate)
 208     {
 209         OIC_LOG_V(DEBUG, TAG, "Packet receiver Stop request received.");
 210         return;
 211     }
 212     if (0 >= ret)
 213     {
 214         if (0 > ret)
 215         {
 216             OIC_LOG_V(FATAL, TAG, "select error %s", strerror(errno));
 217         }
 218         return;
 219     }
 220
 221     CASelectReturned(&readFds, ret);
 222 }
 223
 224 static void CASelectReturned(fd_set *readFds, int ret)
 225 {
 226     (void)ret;
 227
 228     if (g_acceptServerFD != -1 && FD_ISSET(g_acceptServerFD, readFds))
 229     {
 230         CAAcceptConnection();
 231         return;
 232     }
 233     else if (-1 != caglobals.tcp.connectionFds[0] &&
 234             FD_ISSET(caglobals.tcp.connectionFds[0], readFds))
 235     {
 236         // new connection was created from remote device.
 237         // exit the function to update read file descriptor.
 238         char buf[MAX_ADDR_STR_SIZE_CA] = {0};
 239         ssize_t len = read(caglobals.tcp.connectionFds[0], buf, sizeof (buf));
 240         if (-1 == len)
 241         {
 242             return;
 243         }
 244         OIC_LOG_V(DEBUG, TAG, "Received new connection event with [%s]", buf);
 245         FD_CLR(caglobals.tcp.connectionFds[0], readFds);
 246         return;
 247     }
 248     else
 249     {
 250         uint32_t length = u_arraylist_length(caglobals.tcp.svrlist);
 251         for (size_t i = 0; i < length; i++)
 252         {
 253             CATCPSessionInfo_t *svritem =
 254                     (CATCPSessionInfo_t *) u_arraylist_get(caglobals.tcp.svrlist, i);
 255             if (svritem && svritem->fd >= 0)
 256             {
 257                 if (FD_ISSET(svritem->fd, readFds))
 258                 {
 259                     CAReceiveMessage(svritem->fd);
 260                     FD_CLR(svritem->fd, readFds);
 261                 }
 262             }
 263         }
 264     }
 265 }
 266
 267 static void CAAcceptConnection()
 268 {
 269     struct sockaddr_storage clientaddr;
 270     socklen_t clientlen = sizeof (struct sockaddr_in);
 271
 272     int sockfd = accept(g_acceptServerFD, (struct sockaddr *)&clientaddr,
 273                         &clientlen);
 274     if (-1 != sockfd)
 275     {
 276         CATCPSessionInfo_t *svritem =
 277                 (CATCPSessionInfo_t *) OICCalloc(1, sizeof (*svritem));
 278         if (!svritem)
 279         {
 280             OIC_LOG(ERROR, TAG, "Out of memory");
 281             close(sockfd);
 282             return;
 283         }
 284
 285         svritem->fd = sockfd;
 286         CAConvertAddrToName((struct sockaddr_storage *)&clientaddr, clientlen,
 287                             (char *) &svritem->sep.endpoint.addr, &svritem->sep.endpoint.port);
 288
 289         ca_mutex_lock(g_mutexObjectList);
 290         bool result = u_arraylist_add(caglobals.tcp.svrlist, svritem);
 291         if (!result)
 292         {
 293             OIC_LOG(ERROR, TAG, "u_arraylist_add failed.");
 294             close(sockfd);
 295             OICFree(svritem);
 296             ca_mutex_unlock(g_mutexObjectList);
 297             return;
 298         }
 299         ca_mutex_unlock(g_mutexObjectList);
 300
 301         CHECKFD(sockfd);
 302     }
 303 }
 304
 305 static void CAReceiveMessage(int fd)
 306 {
 307     // #1. get remote device information from file descriptor.
 308     size_t index = 0;
 309     CATCPSessionInfo_t *svritem = CAGetSessionInfoFromFD(fd, &index);
 310     if (!svritem)
 311     {
 312         OIC_LOG(ERROR, TAG, "there is no connection information in list");
 313         return;
 314     }
 315
 316     // #2. get already allocated memory size.
 317     size_t bufSize = (svritem->totalDataLen == 0) ? TCP_MAX_HEADER_LEN : svritem->totalDataLen;
 318     if (!svritem->recvData)
 319     {
 320         svritem->recvData = (unsigned char *) OICCalloc(1, bufSize);
 321         if (!svritem->recvData)
 322         {
 323             OIC_LOG(ERROR, TAG, "out of memory");
 324             CADisconnectTCPSession(svritem, index);
 325             return;
 326         }
 327     }
 328
 329     // #3. receive data from remote device.
 330     ssize_t recvLen = recv(fd, svritem->recvData + svritem->recvDataLen,
 331                            bufSize - svritem->recvDataLen, 0);
 332     if (recvLen <= 0)
 333     {
 334         if(EWOULDBLOCK != errno)
 335         {
 336             OIC_LOG_V(ERROR, TAG, "Recvfrom failed %s", strerror(errno));
 337             CADisconnectTCPSession(svritem, index);
 338         }
 339         return;
 340     }
 341     svritem->recvDataLen += recvLen;
 342
 343     // #4. get actual data length from coap over tcp header.
 344     if (!svritem->totalDataLen)
 345     {
 346         coap_transport_type transport = coap_get_tcp_header_type_from_initbyte(
 347                 ((unsigned char *) svritem->recvData)[0] >> 4);
 348
 349         size_t headerLen = coap_get_tcp_header_length_for_transport(transport);
 350         if (svritem->recvDataLen >= headerLen)
 351         {
 352             svritem->totalDataLen = CAGetTotalLengthFromHeader(
 353                     (unsigned char *) svritem->recvData);
 354             bufSize = svritem->totalDataLen;
 355             unsigned char *newBuf = OICRealloc(svritem->recvData, bufSize);
 356             if (!newBuf)
 357             {
 358                 OIC_LOG(ERROR, TAG, "out of memory");
 359                 CADisconnectTCPSession(svritem, index);
 360                 return;
 361             }
 362             svritem->recvData = newBuf;
 363         }
 364     }
 365
 366     // #5. pass the received data information to upper layer.
 367     if ((svritem->totalDataLen == svritem->recvDataLen) && g_packetReceivedCallback)
 368     {
 369         svritem->sep.endpoint.adapter = CA_ADAPTER_TCP;
 370         g_packetReceivedCallback(&svritem->sep, svritem->recvData, svritem->recvDataLen);
 371         OIC_LOG_V(DEBUG, TAG, "total received data len:%d", svritem->recvDataLen);
 372
 373         // initialize data info to receive next message.
 374         OICFree(svritem->recvData);
 375         svritem->recvData = NULL;
 376         svritem->recvDataLen = 0;
 377         svritem->totalDataLen = 0;
 378     }
 379
 380     return;
 381 }
 382
 383 static void CAWakeUpForReadFdsUpdate(const char *host)
 384 {
 385     if (caglobals.tcp.connectionFds[1] != -1)
 386     {
 387         ssize_t len = 0;
 388         do
 389         {
 390             len = write(caglobals.tcp.connectionFds[1], host, strlen(host));
 391         } while ((len == -1) && (errno == EINTR));
 392
 393         if ((len == -1) && (errno != EINTR) && (errno != EPIPE))
 394         {
 395             OIC_LOG_V(DEBUG, TAG, "write failed: %s", strerror(errno));
 396         }
 397     }
 398 }
 399
 400 static int CATCPCreateSocket(int family, CATCPSessionInfo_t *svritem)
 401 {
 402     // create tcp socket
 403     int fd = socket(family, SOCK_STREAM, IPPROTO_TCP);
 404     if (-1 == fd)
 405     {
 406         OIC_LOG_V(ERROR, TAG, "create socket failed: %s", strerror(errno));
 407         goto exit;
 408     }
 409
 410     struct sockaddr_storage sa = { .ss_family = family };
 411     CAConvertNameToAddr(svritem->sep.endpoint.addr, svritem->sep.endpoint.port, &sa);
 412     socklen_t socklen = sizeof (struct sockaddr_in);
 413
 414     // connect to TCP server
 415     int ret = connect(fd, (struct sockaddr *)&sa, socklen);
 416     if (0 == ret)
 417     {
 418         OIC_LOG(DEBUG, TAG, "connect socket success");
 419         CAWakeUpForReadFdsUpdate(svritem->sep.endpoint.addr);
 420     }
 421     else
 422     {
 423         OIC_LOG(ERROR, TAG, "failed to connect socket");
 424         goto exit;
 425     }
 426
 427     return fd;
 428
 429 exit:
 430     if (fd >= 0)
 431     {
 432         close(fd);
 433     }
 434     return -1;
 435 }
 436
 437 static CAResult_t CACreateAcceptSocket()
 438 {
 439     if (g_acceptServerFD != -1)
 440     {
 441         OIC_LOG(DEBUG, TAG, "accept socket created already");
 442         return CA_STATUS_OK;
 443     }
 444
 445     int reuse = 1;
 446     struct sockaddr_in server = { .sin_addr.s_addr = INADDR_ANY,
 447                                   .sin_family = AF_INET,
 448                                   .sin_port = htons(SERVER_PORT),
 449                                   .sin_zero = { 0 } };
 450
 451     g_acceptServerFD = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
 452     if (g_acceptServerFD < 0)
 453     {
 454         OIC_LOG(ERROR, TAG, "Failed to create socket");
 455         goto exit;
 456     }
 457
 458     if (-1 == setsockopt(g_acceptServerFD, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse)))
 459     {
 460         OIC_LOG(ERROR, TAG, "setsockopt SO_REUSEADDR");
 461         goto exit;
 462     }
 463
 464     int serverlen = sizeof(server);
 465     if (-1 == bind(g_acceptServerFD, (struct sockaddr *)&server, serverlen))
 466     {
 467         OIC_LOG(ERROR, TAG, "bind() error");
 468         goto exit;
 469     }
 470
 471     if (listen(g_acceptServerFD, caglobals.tcp.listenBacklog) != 0)
 472     {
 473         OIC_LOG(ERROR, TAG, "listen() error");
 474         goto exit;
 475     }
 476
 477     CHECKFD(g_acceptServerFD);
 478
 479     return CA_STATUS_OK;
 480
 481 exit:
 482     if (g_acceptServerFD >= 0)
 483     {
 484         close(g_acceptServerFD);
 485         g_acceptServerFD = -1;
 486     }
 487     return CA_STATUS_FAILED;
 488 }
 489
 490 static void CAInitializePipe(int *fds)
 491 {
 492     int ret = pipe(fds);
 493     if (-1 != ret)
 494     {
 495         ret = fcntl(fds[0], F_GETFD);
 496         if (-1 != ret)
 497         {
 498             ret = fcntl(fds[0], F_SETFD, ret|FD_CLOEXEC);
 499         }
 500         if (-1 != ret)
 501         {
 502             ret = fcntl(fds[1], F_GETFD);
 503         }
 504         if (-1 != ret)
 505         {
 506             ret = fcntl(fds[1], F_SETFD, ret|FD_CLOEXEC);
 507         }
 508         if (-1 == ret)
 509         {
 510             close(fds[1]);
 511             close(fds[0]);
 512
 513             fds[0] = -1;
 514             fds[1] = -1;
 515
 516             OIC_LOG_V(ERROR, TAG, "pipe failed: %s", strerror(errno));
 517         }
 518     }
 519 }
 520
 521 CAResult_t CATCPStartServer(const ca_thread_pool_t threadPool)
 522 {
 523     if (caglobals.tcp.started)
 524     {
 525         return CA_STATUS_OK;
 526     }
 527
 528     if (!caglobals.tcp.ipv4tcpenabled)
 529     {
 530         caglobals.tcp.ipv4tcpenabled = true;    // only needed to run CA tests
 531     }
 532
 533     CAResult_t res = CATCPCreateMutex();
 534     if (CA_STATUS_OK == res)
 535     {
 536         res = CATCPCreateCond();
 537     }
 538     if (CA_STATUS_OK != res)
 539     {
 540         OIC_LOG(ERROR, TAG, "failed to create mutex/cond");
 541         return res;
 542     }
 543
 544     ca_mutex_lock(g_mutexObjectList);
 545     if (!caglobals.tcp.svrlist)
 546     {
 547         caglobals.tcp.svrlist = u_arraylist_create();
 548     }
 549     ca_mutex_unlock(g_mutexObjectList);
 550
 551     if (caglobals.server)
 552     {
 553         res = CACreateAcceptSocket();
 554         if (CA_STATUS_OK != res)
 555         {
 556             OIC_LOG(ERROR, TAG, "failed to create accept socket");
 557             return res;
 558         }
 559     }
 560
 561     // create pipe for fast shutdown
 562     CAInitializePipe(caglobals.tcp.shutdownFds);
 563     CHECKFD(caglobals.tcp.shutdownFds[0]);
 564     CHECKFD(caglobals.tcp.shutdownFds[1]);
 565
 566     // create pipe for connection event
 567     CAInitializePipe(caglobals.tcp.connectionFds);
 568     CHECKFD(caglobals.tcp.connectionFds[0]);
 569     CHECKFD(caglobals.tcp.connectionFds[1]);
 570
 571     caglobals.tcp.terminate = false;
 572     res = ca_thread_pool_add_task(threadPool, CAReceiveHandler, NULL);
 573     if (CA_STATUS_OK != res)
 574     {
 575         OIC_LOG(ERROR, TAG, "thread_pool_add_task failed");
 576         return res;
 577     }
 578     OIC_LOG(DEBUG, TAG, "CAReceiveHandler thread started successfully.");
 579
 580     caglobals.tcp.started = true;
 581     return CA_STATUS_OK;
 582 }
 583
 584 void CATCPStopServer()
 585 {
 586     // mutex lock
 587     ca_mutex_lock(g_mutexObjectList);
 588
 589     // set terminate flag
 590     caglobals.tcp.terminate = true;
 591
 592     if (caglobals.tcp.shutdownFds[1] != -1)
 593     {
 594         close(caglobals.tcp.shutdownFds[1]);
 595         // receive thread will stop immediately
 596     }
 597
 598     if (caglobals.tcp.connectionFds[1] != -1)
 599     {
 600         close(caglobals.tcp.connectionFds[1]);
 601     }
 602
 603     if (caglobals.tcp.started)
 604     {
 605         ca_cond_wait(g_condObjectList, g_mutexObjectList);
 606     }
 607     caglobals.tcp.started = false;
 608
 609     // mutex unlock
 610     ca_mutex_unlock(g_mutexObjectList);
 611
 612     if (-1 != g_acceptServerFD)
 613     {
 614         close(g_acceptServerFD);
 615         g_acceptServerFD = -1;
 616     }
 617
 618     CATCPDisconnectAll();
 619     CATCPDestroyMutex();
 620     CATCPDestroyCond();
 621 }
 622
 623 void CATCPSetPacketReceiveCallback(CATCPPacketReceivedCallback callback)
 624 {
 625     g_packetReceivedCallback = callback;
 626 }
 627
 628 void CATCPSetKeepAliveCallback(CATCPKeepAliveHandleCallback keepaliveHandler)
 629 {
 630     g_keepaliveCallback = keepaliveHandler;
 631 }
 632
 633 static size_t CACheckPayloadLength(const void *data, size_t dlen)
 634 {
 635     VERIFY_NON_NULL_RET(data, TAG, "data", -1);
 636
 637     coap_transport_type transport = coap_get_tcp_header_type_from_initbyte(
 638             ((unsigned char *)data)[0] >> 4);
 639
 640     coap_pdu_t *pdu = coap_new_pdu(transport, dlen);
 641     if (!pdu)
 642     {
 643         OIC_LOG(ERROR, TAG, "outpdu is null");
 644         return 0;
 645     }
 646
 647     int ret = coap_pdu_parse((unsigned char *) data, dlen, pdu, transport);
 648     if (0 >= ret)
 649     {
 650         OIC_LOG(ERROR, TAG, "pdu parse failed");
 651         coap_delete_pdu(pdu);
 652         return 0;
 653     }
 654
 655     size_t payloadLen = 0;
 656     size_t headerSize = coap_get_tcp_header_length_for_transport(transport);
 657     OIC_LOG_V(DEBUG, TAG, "headerSize : %d, pdu length : %d",
 658               headerSize, pdu->length);
 659     if (pdu->length > headerSize)
 660     {
 661         payloadLen = (unsigned char *) pdu->hdr + pdu->length - pdu->data;
 662     }
 663
 664     OICFree(pdu);
 665
 666     return payloadLen;
 667 }
 668
 669 static void sendData(const CAEndpoint_t *endpoint,
 670                      const void *data, size_t dlen)
 671 {
 672     // #1. get TCP Server object from list
 673     size_t index = 0;
 674     CATCPSessionInfo_t *svritem = CAGetTCPSessionInfoFromEndpoint(endpoint, &index);
 675     if (!svritem)
 676     {
 677         // if there is no connection info, connect to TCP Server
 678         svritem = CAConnectTCPSession(endpoint);
 679         if (!svritem)
 680         {
 681             OIC_LOG(ERROR, TAG, "Failed to create TCP server object");
 682             g_TCPErrorHandler(endpoint, data, dlen, CA_SEND_FAILED);
 683             return;
 684         }
 685     }
 686
 687     // #2. check payload length
 688     size_t payloadLen = CACheckPayloadLength(data, dlen);
 689     // if payload length is zero, disconnect from TCP server
 690     if (!payloadLen)
 691     {
 692         OIC_LOG(DEBUG, TAG, "payload length is zero, disconnect from remote device");
 693         CADisconnectTCPSession(svritem, index);
 694         return;
 695     }
 696
 697     // #3. check connection state
 698     if (svritem->fd < 0)
 699     {
 700         // if file descriptor value is wrong, remove TCP Server info from list
 701         OIC_LOG(ERROR, TAG, "Failed to connect to TCP server");
 702         CADisconnectTCPSession(svritem, index);
 703         g_TCPErrorHandler(endpoint, data, dlen, CA_SEND_FAILED);
 704         return;
 705     }
 706
 707     // #4. send data to TCP Server
 708     ssize_t remainLen = dlen;
 709     do
 710     {
 711         ssize_t len = send(svritem->fd, data, remainLen, 0);
 712         if (-1 == len)
 713         {
 714             if (EWOULDBLOCK != errno)
 715             {
 716                 OIC_LOG_V(ERROR, TAG, "unicast ipv4tcp sendTo failed: %s", strerror(errno));
 717                 g_TCPErrorHandler(endpoint, data, dlen, CA_SEND_FAILED);
 718                 return;
 719             }
 720             continue;
 721         }
 722         data += len;
 723         remainLen -= len;
 724     } while (remainLen > 0);
 725
 726     OIC_LOG_V(INFO, TAG, "unicast ipv4tcp sendTo is successful: %zu bytes", dlen);
 727 }
 728
 729 void CATCPSendData(CAEndpoint_t *endpoint, const void *data, uint32_t datalen,
 730                    bool isMulticast)
 731 {
 732     VERIFY_NON_NULL_VOID(endpoint, TAG, "endpoint is NULL");
 733     VERIFY_NON_NULL_VOID(data, TAG, "data is NULL");
 734
 735     if (!isMulticast)
 736     {
 737         if (caglobals.tcp.ipv4tcpenabled && (endpoint->adapter & CA_ADAPTER_TCP))
 738         {
 739             sendData(endpoint, data, datalen);
 740         }
 741     }
 742 }
 743
 744 CAResult_t CAGetTCPInterfaceInformation(CAEndpoint_t **info, uint32_t *size)
 745 {
 746     VERIFY_NON_NULL(info, TAG, "info is NULL");
 747     VERIFY_NON_NULL(size, TAG, "size is NULL");
 748
 749     return CA_NOT_SUPPORTED;
 750 }
 751
 752 CATCPSessionInfo_t *CAConnectTCPSession(const CAEndpoint_t *endpoint)
 753 {
 754     VERIFY_NON_NULL_RET(endpoint, TAG, "endpoint is NULL", NULL);
 755
 756     // #1. create TCP server object
 757     CATCPSessionInfo_t *svritem = (CATCPSessionInfo_t *) OICCalloc(1, sizeof (*svritem));
 758     if (!svritem)
 759     {
 760         OIC_LOG(ERROR, TAG, "Out of memory");
 761         return NULL;
 762     }
 763     memcpy(svritem->sep.endpoint.addr, endpoint->addr, sizeof(svritem->sep.endpoint.addr));
 764     svritem->sep.endpoint.port = endpoint->port;
 765
 766     // #2. create the socket and connect to TCP server
 767     if (caglobals.tcp.ipv4tcpenabled)
 768     {
 769         int fd = CATCPCreateSocket(AF_INET, svritem);
 770         if (-1 == fd)
 771         {
 772             OICFree(svritem);
 773             return NULL;
 774         }
 775
 776         // #3. add TCP connection info to list
 777         svritem->fd = fd;
 778         ca_mutex_lock(g_mutexObjectList);
 779         if (caglobals.tcp.svrlist)
 780         {
 781             bool res = u_arraylist_add(caglobals.tcp.svrlist, svritem);
 782             if (!res)
 783             {
 784                 OIC_LOG(ERROR, TAG, "u_arraylist_add failed.");
 785                 close(svritem->fd);
 786                 OICFree(svritem);
 787                 ca_mutex_unlock(g_mutexObjectList);
 788                 return NULL;
 789             }
 790         }
 791         ca_mutex_unlock(g_mutexObjectList);
 792
 793         CHECKFD(fd);
 794
 795         // pass the connection information to RI for keepalive.
 796         if (g_keepaliveCallback)
 797         {
 798             g_keepaliveCallback(svritem->sep.endpoint.addr, svritem->sep.endpoint.port, true);
 799         }
 800     }
 801
 802     return svritem;
 803 }
 804
 805 CAResult_t CADisconnectTCPSession(CATCPSessionInfo_t *svritem, size_t index)
 806 {
 807     VERIFY_NON_NULL(svritem, TAG, "svritem is NULL");
 808
 809     ca_mutex_lock(g_mutexObjectList);
 810
 811     // close the socket and remove TCP connection info in list
 812     if (svritem->fd >= 0)
 813     {
 814         close(svritem->fd);
 815     }
 816     u_arraylist_remove(caglobals.tcp.svrlist, index);
 817     OICFree(svritem->recvData);
 818     OICFree(svritem);
 819     ca_mutex_unlock(g_mutexObjectList);
 820
 821     // pass the connection information to RI for keepalive.
 822     if (g_keepaliveCallback)
 823     {
 824         g_keepaliveCallback(svritem->sep.endpoint.addr, svritem->sep.endpoint.port, false);
 825     }
 826
 827     return CA_STATUS_OK;
 828 }
 829
 830 void CATCPDisconnectAll()
 831 {
 832     ca_mutex_lock(g_mutexObjectList);
 833     uint32_t length = u_arraylist_length(caglobals.tcp.svrlist);
 834
 835     CATCPSessionInfo_t *svritem = NULL;
 836     for (size_t i = 0; i < length; i++)
 837     {
 838         svritem = (CATCPSessionInfo_t *) u_arraylist_get(caglobals.tcp.svrlist, i);
 839         if (svritem && svritem->fd >= 0)
 840         {
 841             shutdown(svritem->fd, SHUT_RDWR);
 842             close(svritem->fd);
 843             OICFree(svritem->recvData);
 844         }
 845     }
 846     u_arraylist_destroy(caglobals.tcp.svrlist);
 847     ca_mutex_unlock(g_mutexObjectList);
 848 }
 849
 850 CATCPSessionInfo_t *CAGetTCPSessionInfoFromEndpoint(const CAEndpoint_t *endpoint,
 851                                                     size_t *index)
 852 {
 853     VERIFY_NON_NULL_RET(endpoint, TAG, "endpoint is NULL", NULL);
 854     VERIFY_NON_NULL_RET(index, TAG, "index is NULL", NULL);
 855
 856     // get connection info from list
 857     uint32_t length = u_arraylist_length(caglobals.tcp.svrlist);
 858     for (size_t i = 0; i < length; i++)
 859     {
 860         CATCPSessionInfo_t *svritem = (CATCPSessionInfo_t *) u_arraylist_get(
 861                 caglobals.tcp.svrlist, i);
 862         if (!svritem)
 863         {
 864             continue;
 865         }
 866
 867         if (!strncmp(svritem->sep.endpoint.addr, endpoint->addr,
 868                      sizeof(svritem->sep.endpoint.addr))
 869                 && (svritem->sep.endpoint.port == endpoint->port))
 870         {
 871             *index = i;
 872             return svritem;
 873         }
 874     }
 875
 876     return NULL;
 877 }
 878
 879 CATCPSessionInfo_t *CAGetSessionInfoFromFD(int fd, size_t *index)
 880 {
 881     ca_mutex_lock(g_mutexObjectList);
 882
 883     // check from the last item.
 884     CATCPSessionInfo_t *svritem = NULL;
 885     uint32_t length = u_arraylist_length(caglobals.tcp.svrlist);
 886     for (size_t i = 0; i < length; i++)
 887     {
 888         svritem = (CATCPSessionInfo_t *) u_arraylist_get(caglobals.tcp.svrlist, i);
 889
 890         if (svritem && svritem->fd == fd)
 891         {
 892             *index = i;
 893             ca_mutex_unlock(g_mutexObjectList);
 894             return svritem;
 895         }
 896     }
 897
 898     ca_mutex_unlock(g_mutexObjectList);
 899
 900     return NULL;
 901 }
 902
 903 size_t CAGetTotalLengthFromHeader(const unsigned char *recvBuffer)
 904 {
 905     OIC_LOG(DEBUG, TAG, "IN - CAGetTotalLengthFromHeader");
 906
 907     coap_transport_type transport = coap_get_tcp_header_type_from_initbyte(
 908             ((unsigned char *)recvBuffer)[0] >> 4);
 909     size_t optPaylaodLen = coap_get_length_from_header((unsigned char *)recvBuffer,
 910                                                         transport);
 911     size_t headerLen = coap_get_tcp_header_length((unsigned char *)recvBuffer);
 912
 913     OIC_LOG_V(DEBUG, TAG, "option/paylaod length [%d]", optPaylaodLen);
 914     OIC_LOG_V(DEBUG, TAG, "header length [%d]", headerLen);
 915     OIC_LOG_V(DEBUG, TAG, "total data length [%d]", headerLen + optPaylaodLen);
 916
 917     OIC_LOG(DEBUG, TAG, "OUT - CAGetTotalLengthFromHeader");
 918     return headerLen + optPaylaodLen;
 919 }
 920
 921 void CATCPSetErrorHandler(CATCPErrorHandleCallback errorHandleCallback)
 922 {
 923     g_TCPErrorHandler = errorHandleCallback;
 924 }