static void CAReceiveMessage(int fd)
{
// #1. get remote device information from file descriptor.
size_t index = 0;
CATCPSessionInfo_t *svritem = CAGetSessionInfoFromFD(fd, &index);
if (!svritem)
{
OIC_LOG(ERROR, TAG, "there is no connection information in list");
return;
}
// #2. get already allocated memory size.
size_t bufSize = (svritem->totalDataLen == 0) ? TCP_MAX_HEADER_LEN : svritem->totalDataLen;
if (!svritem->recvData)
{
svritem->recvData = (unsigned char *) OICCalloc(1, bufSize);
if (!svritem->recvData)
{
OIC_LOG(ERROR, TAG, "out of memory");
CADisconnectTCPSession(svritem, index);
return;
}
}
// #3. receive data from remote device.
ssize_t recvLen = recv(fd, svritem->recvData + svritem->recvDataLen,
bufSize - svritem->recvDataLen, 0);
if (recvLen <= 0)
{
if(EWOULDBLOCK != errno)
{
OIC_LOG_V(ERROR, TAG, "Recvfrom failed %s", strerror(errno));
CADisconnectTCPSession(svritem, index);
}
return;
}
svritem->recvDataLen += recvLen;
// #4. get actual data length from coap over tcp header.
if (!svritem->totalDataLen)
{
coap_transport_type transport = coap_get_tcp_header_type_from_initbyte(
((unsigned char *) svritem->recvData)[0] >> 4);
size_t headerLen = coap_get_tcp_header_length_for_transport(transport);
if (svritem->recvDataLen >= headerLen)
{
svritem->totalDataLen = CAGetTotalLengthFromHeader(
(unsigned char *) svritem->recvData);
bufSize = svritem->totalDataLen;
unsigned char *newBuf = OICRealloc(svritem->recvData, bufSize);
if (!newBuf)
{
OIC_LOG(ERROR, TAG, "out of memory");
CADisconnectTCPSession(svritem, index);
return;
}
svritem->recvData = newBuf;
}
}
static CAResult_t CAReceiveMessage()
{
uint32_t length = u_arraylist_length(caglobals.tcp.svrlist);
size_t i = 0;
unsigned char *recvBuffer = NULL;
CATCPServerInfo_t *svritem = NULL;
for (i = 0; i < length; i++)
{
svritem = (CATCPServerInfo_t *) u_arraylist_get(caglobals.tcp.svrlist, i);
if (svritem->u4tcp.fd < 0)
{
continue;
}
size_t bufSize = TCP_MAX_HEADER_LEN;
recvBuffer = (unsigned char *) OICCalloc(1, bufSize);
if (!recvBuffer)
{
OIC_LOG(ERROR, TAG, "out of memory");
goto exit;
}
bool isHeaderChecked = false;
size_t totalLen = 0;
size_t totalReceivedLen = 0;
do
{
ssize_t recvLen = recv(svritem->u4tcp.fd, recvBuffer + totalReceivedLen,
bufSize - totalReceivedLen, 0);
if (recvLen <= 0)
{
if(EWOULDBLOCK != errno)
{
OIC_LOG_V(ERROR, TAG, "Recvfrom failed %s", strerror(errno));
goto exit;
}
// if received data length is zero, we are breaking loop.
// because we use non-blocking socket to receive data from remote device.
if (!totalReceivedLen)
{
break;
}
continue;
}
totalReceivedLen += recvLen;
if (!isHeaderChecked && totalReceivedLen)
{
coap_transport_type transport = coap_get_tcp_header_type_from_initbyte(
((unsigned char *)recvBuffer)[0] >> 4);
size_t headerLen = coap_get_tcp_header_length_for_transport(transport);
if (totalReceivedLen >= headerLen)
{
// get actual data length from coap over tcp header
totalLen = CAGetTotalLengthFromHeader((unsigned char *) recvBuffer);
bufSize = totalLen;
unsigned char *newBuf = OICRealloc(recvBuffer, bufSize);
if (NULL == newBuf)
{
OIC_LOG(ERROR, TAG, "out of memory");
goto exit;
}
recvBuffer = newBuf;
isHeaderChecked = true;
}
}
if (totalLen == totalReceivedLen)
{
CAEndpoint_t ep = { .adapter = CA_ADAPTER_TCP,
.port = svritem->u4tcp.port };
strncpy(ep.addr, svritem->addr, sizeof(ep.addr));
if (g_packetReceivedCallback)
{
g_packetReceivedCallback(&ep, recvBuffer, totalLen);
}
OIC_LOG_V(DEBUG, TAG, "received data len:%d", totalLen);
break;
}
} while (!totalLen || totalLen > totalReceivedLen);
OICFree(recvBuffer);
}
