void SDPContainer::PrintLine(SInt32 lineIndex)
{
StrPtrLen *printLinePtr = GetLine(lineIndex);
if (printLinePtr)
{ printLinePtr->PrintStr();
qtss_printf("\n");
}
}
QTSS_Error RTSPRequestStream::ReadRequest()
{
while (true)
{
UInt32 newOffset = 0;
//If this is the case, we already HAVE a request on this session, and we now are done
//with the request and want to move onto the next one. The first thing we should do
//is check whether there is any lingering data in the stream. If there is, the parent
//session believes that is part of a new request
if (fRequestPtr != NULL)
{
fRequestPtr = NULL;//flag that we no longer have a complete request
// Take all the retreated leftover data and move it to the beginning of the buffer
if ((fRetreatBytes > 0) && (fRequest.Len > 0))
::memmove(fRequest.Ptr, fRequest.Ptr + fRequest.Len + fRetreatBytesRead, fRetreatBytes);
// if we are decoding, we need to also move over the remaining encoded bytes
// to the right position in the fRequestBuffer
if (fEncodedBytesRemaining > 0)
{
//Assert(fEncodedBytesRemaining < 4);
// The right position is at fRetreatBytes offset in the request buffer. The reason for this is:
// 1) We need to find a place in the request buffer where we know we have enough space to store
// fEncodedBytesRemaining. fRetreatBytes + fEncodedBytesRemaining will always be less than
// kRequestBufferSize because all this data must have been in the same request buffer, together, at one point.
//
// 2) We need to make sure that there is always more data in the RequestBuffer than in the decoded
// request buffer, otherwise we could overrun the decoded request buffer (we bounds check on the encoded
// buffer, not the decoded buffer). Leaving fRetreatBytes as empty space in the request buffer ensures
// that this principle is maintained.
::memmove(&fRequestBuffer[fRetreatBytes], &fRequestBuffer[fCurOffset - fEncodedBytesRemaining], fEncodedBytesRemaining);
fCurOffset = fRetreatBytes + fEncodedBytesRemaining;
Assert(fCurOffset < kRequestBufferSizeInBytes);
}
else
fCurOffset = fRetreatBytes;
newOffset = fRequest.Len = fRetreatBytes;
fRetreatBytes = fRetreatBytesRead = 0;
}
// We don't have any new data, so try and get some
if (newOffset == 0)
{
if (fRetreatBytes > 0)
{
// This will be true if we've just snarfed another input stream, in which case the encoded data
// is copied into our request buffer, and its length is tracked in fRetreatBytes.
// If this is true, just fall through and decode the data.
newOffset = fRetreatBytes;
fRetreatBytes = 0;
Assert(fEncodedBytesRemaining == 0);
}
else
{
// We don't have any new data, get some from the socket...
QTSS_Error sockErr = fSocket->Read(&fRequestBuffer[fCurOffset],
(kRequestBufferSizeInBytes - fCurOffset) - 1, &newOffset);
//assume the client is dead if we get an error back
if (sockErr == EAGAIN)
return QTSS_NoErr;
if (sockErr != QTSS_NoErr)
{
Assert(!fSocket->IsConnected());
return sockErr;
}
}
if (fDecode)
{
// If we need to decode this data, do it now.
Assert(fCurOffset >= fEncodedBytesRemaining);
QTSS_Error decodeErr = this->DecodeIncomingData(&fRequestBuffer[fCurOffset - fEncodedBytesRemaining],
newOffset + fEncodedBytesRemaining);
// If the above function returns an error, it is because we've
// encountered some non-base64 data in the stream. We can process
// everything up until that point, but all data after this point will
// be ignored.
if (decodeErr == QTSS_NoErr)
Assert(fEncodedBytesRemaining < 4);
}
else
fRequest.Len += newOffset;
Assert(fRequest.Len < kRequestBufferSizeInBytes);
fCurOffset += newOffset;
}
Assert(newOffset > 0);
// See if this is an interleaved data packet
if ('$' == *(fRequest.Ptr))
{
if (fRequest.Len < 4)
continue;
UInt16* dataLenP = (UInt16*)fRequest.Ptr;
UInt32 interleavedPacketLen = ntohs(dataLenP[1]) + 4;
if (interleavedPacketLen > fRequest.Len)
continue;
//put back any data that is not part of the header
fRetreatBytes += fRequest.Len - interleavedPacketLen;
fRequest.Len = interleavedPacketLen;
fRequestPtr = &fRequest;
fIsDataPacket = true;
return QTSS_RequestArrived;
}
fIsDataPacket = false;
if (fPrintRTSP)
{
DateBuffer theDate;
DateTranslator::UpdateDateBuffer(&theDate, 0); // get the current GMT date and time
qtss_printf("\n\n#C->S:\n#time: ms=%lu date=%s\n", (UInt32) OS::StartTimeMilli_Int(), theDate.GetDateBuffer());
if (fSocket != NULL)
{
UInt16 serverPort = fSocket->GetLocalPort();
UInt16 clientPort = fSocket->GetRemotePort();
StrPtrLen* theLocalAddrStr = fSocket->GetLocalAddrStr();
StrPtrLen* theRemoteAddrStr = fSocket->GetRemoteAddrStr();
if (theLocalAddrStr != NULL)
{ qtss_printf("#server: ip="); theLocalAddrStr->PrintStr(); qtss_printf(" port=%u\n" , serverPort );
}
else
{ qtss_printf("#server: ip=NULL port=%u\n" , serverPort );
}
if (theRemoteAddrStr != NULL)
{ qtss_printf("#client: ip="); theRemoteAddrStr->PrintStr(); qtss_printf(" port=%u\n" , clientPort );
}
else
{ qtss_printf("#client: ip=NULL port=%u\n" , clientPort );
}
}
StrPtrLen str(fRequest);
str.PrintStrEOL("\n\r\n", "\n");// print the request but stop on \n\r\n and add a \n afterwards.
}
//use a StringParser object to search for a double EOL, which signifies the end of
//the header.
Bool16 weAreDone = false;
StringParser headerParser(&fRequest);
UInt16 lcount = 0;
while (headerParser.GetThruEOL(NULL))
{
lcount++;
if (headerParser.ExpectEOL())
{
//The legal end-of-header sequences are \r\r, \r\n\r\n, & \n\n. NOT \r\n\r!
//If the packets arrive just a certain way, we could get here with the latter
//combo, and not wait for a final \n.
if ((headerParser.GetDataParsedLen() > 2) &&
(memcmp(headerParser.GetCurrentPosition() - 3, "\r\n\r", 3) == 0))
continue;
weAreDone = true;
break;
}
else if (lcount == 1) {
// if this request is actually a ShoutCast password it will be
// in the form of "xxxxxx\r" where "xxxxx" is the password.
// If we get a 1st request line ending in \r with no blanks we will
// assume that this is the end of the request.
UInt16 flag = 0;
UInt16 i = 0;
for (i=0; i<fRequest.Len; i++)
{
if (fRequest.Ptr[i] == ' ')
flag++;
}
if (flag == 0)
{
weAreDone = true;
break;
}
}
}
//weAreDone means we have gotten a full request
if (weAreDone)
{
//put back any data that is not part of the header
fRequest.Len -= headerParser.GetDataRemaining();
fRetreatBytes += headerParser.GetDataRemaining();
fRequestPtr = &fRequest;
return QTSS_RequestArrived;
}
//check for a full buffer
if (fCurOffset == kRequestBufferSizeInBytes - 1)
{
fRequestPtr = &fRequest;
return E2BIG;
}
}
}
/* 从RTSP Request stream中获取full RTSP Request Header,打印fRequest相关信息,解析得到它的尾部,并配置相应数据成员的值 */
QTSS_Error RTSPRequestStream::ReadRequest()
{
while (true)
{
/* 注意这个量非常重要 */
UInt32 newOffset = 0;
//If this is the case, we already HAVE a request on this session, and we now are done
//with the request and want to move onto the next one. The first thing we should do
//is check whether there is any lingering(延迟的) data in the stream. If there is, the parent
//session believes that is part of a new request
if (fRequestPtr != NULL)
{
/* 标记不再有complete RTSP client Request */
fRequestPtr = NULL;//flag that we no longer have a complete request
// Take all the retreated leftover(剩余的) data and move it to the beginning of the buffer
if ((fRetreatBytes > 0) && (fRequest.Len > 0))
::memmove(fRequest.Ptr, fRequest.Ptr + fRequest.Len + fRetreatBytesRead/* NOTE! */, fRetreatBytes);
// if we are decoding, we need to also move over the remaining encoded bytes
// to the right position in the fRequestBuffer
if (fEncodedBytesRemaining > 0)
{
/* 参见RTSPRequestStream::DecodeIncomingData() */
//Assert(fEncodedBytesRemaining < 4);
// The right position is at fRetreatBytes offset in the request buffer. The reason for this is:
// 1) We need to find a place in the request buffer where we know we have enough space to store
// fEncodedBytesRemaining. fRetreatBytes + fEncodedBytesRemaining will always be less than
// kRequestBufferSize because all this data must have been in the same request buffer, together, at one point.
//
// 2) We need to make sure that there is always more data in the RequestBuffer than in the decoded
// request buffer, otherwise we could overrun(超出限度) the decoded request buffer (we bounds check on the encoded
// buffer, not the decoded buffer). Leaving fRetreatBytes as empty space in the request buffer ensures
// that this principle is maintained.
::memmove(&fRequestBuffer[fRetreatBytes], &fRequestBuffer[fCurOffset - fEncodedBytesRemaining], fEncodedBytesRemaining);
fCurOffset = fRetreatBytes + fEncodedBytesRemaining;
Assert(fCurOffset < kRequestBufferSizeInBytes);
}
else
fCurOffset = fRetreatBytes;
newOffset = fRequest.Len = fRetreatBytes;
/* 因为已将Retreat data移位了 */
fRetreatBytes = fRetreatBytesRead = 0;
}
// We don't have any new data, so try and get some
/* 以下操作是确保newOffset>0 */
if (newOffset == 0)
{
if (fRetreatBytes > 0)
{
// This will be true if we've just snarfed(复制) another input stream, in which case the encoded data
// is copied into our request buffer, and its length is tracked(追踪) in fRetreatBytes.
// If this is true, just fall through(进行下去) and decode the data.
newOffset = fRetreatBytes;
fRetreatBytes = 0;
Assert(fEncodedBytesRemaining == 0);
}
else
{
// We don't have any new data, get some from the socket...
/* 利用TCPSocket的::recv()来接收数据,第一,二个参数是缓存地址和长度,第三个参数是接收数据的长度 */
QTSS_Error sockErr = fSocket->Read(&fRequestBuffer[fCurOffset],
(kRequestBufferSizeInBytes - fCurOffset) - 1, &newOffset);
//assume the client is dead if we get an error back
/* 目前缓冲区无数据可读 */
/* 当recv系统调用返回这个值时表示recv读数据时，对方没有发送数据过来。 */
if (sockErr == EAGAIN)
return QTSS_NoErr;
/* 假如返回出错,一定是连接断开 */
if (sockErr != QTSS_NoErr)
{
Assert(!fSocket->IsConnected());
return sockErr;
}
}
/* 当要base64 decode时 */
if (fDecode)
{
// If we need to decode this data, do it now.
/* 确保数据偏移量大于内存中需要decode的数据 */
Assert(fCurOffset >= fEncodedBytesRemaining);
/* 解密读进来的数据 */
QTSS_Error decodeErr = this->DecodeIncomingData(&fRequestBuffer[fCurOffset - fEncodedBytesRemaining],
newOffset + fEncodedBytesRemaining);
// If the above function returns an error, it is because we've
// encountered some non-base64 data in the stream. We can process
// everything up until that point, but all data after this point will
// be ignored.
/* 解码成功时,确保最后剩下的未解码的数据少于4个字节,参见下面的RTSPRequestStream::DecodeIncomingData() */
if (decodeErr == QTSS_NoErr)
Assert(fEncodedBytesRemaining < 4);
}
else
fRequest.Len += newOffset;
Assert(fRequest.Len < kRequestBufferSizeInBytes);
fCurOffset += newOffset;
}
/* 最后一定要达到这个结论! */
Assert(newOffset > 0);
// See if this is an interleaved data packet
/* 查找data packet,配置fIsDataPacket的值 */
/* 找到data packet */
if ('$' == *(fRequest.Ptr))
{
if (fRequest.Len < 4)
continue;
UInt16* dataLenP = (UInt16*)fRequest.Ptr;
/* 获取混叠包长度 */
UInt32 interleavedPacketLen = ntohs(dataLenP[1]) + 4;
if (interleavedPacketLen > fRequest.Len)
continue;
//put back any data that is not part of the header
/* 将不是header部分的数据放回失控数据处 */
fRetreatBytes += fRequest.Len - interleavedPacketLen;
fRequest.Len = interleavedPacketLen;
fRequestPtr = &fRequest;
fIsDataPacket = true;
return QTSS_RequestArrived;
}
fIsDataPacket = false;
/* 当打印RTSP info时,打印出如下信息:
(空两行)
#C->S;
#time: ms=*** data=Mon,29 July 2009 15:17:17 GTM
#server: ip=172.16.32.37 port=***
或#server: ip=NULL port=***
#client: ip=172.16.39.30 port=***
或#client: ip=NULL port=***
*********fRequest info***************
*/
if (fPrintRTSP)
{
/* 类似RTSPResponseStream::WriteV() */
/* 得到当前的GTM时间,格式为"Mon, 04 Nov 1996 21:42:17 GMT" */
DateBuffer theDate;
DateTranslator::UpdateDateBuffer(&theDate, 0); // get the current GMT date and time
/* OS::StartTimeMilli_Int()表示服务器运行多长时间? */
qtss_printf("\n\n#C->S:\n#time: ms=%lu date=%s\n", (UInt32) OS::StartTimeMilli_Int(), theDate.GetDateBuffer());
/* 假如有TCPSocket存在,就获取并打印其相关信息 */
if (fSocket != NULL)
{
UInt16 serverPort = fSocket->GetLocalPort();
UInt16 clientPort = fSocket->GetRemotePort();
StrPtrLen* theLocalAddrStr = fSocket->GetLocalAddrStr();
StrPtrLen* theRemoteAddrStr = fSocket->GetRemoteAddrStr();
if (theLocalAddrStr != NULL)
{ qtss_printf("#server: ip="); theLocalAddrStr->PrintStr(); qtss_printf(" port=%u\n" , serverPort );
}
else
{ qtss_printf("#server: ip=NULL port=%u\n" , serverPort );
}
if (theRemoteAddrStr != NULL)
{ qtss_printf("#client: ip="); theRemoteAddrStr->PrintStr(); qtss_printf(" port=%u\n" , clientPort );
}
else
{ qtss_printf("#client: ip=NULL port=%u\n" , clientPort );
}
}
/* 打印fRequest字符串 */
StrPtrLen str(fRequest);
str.PrintStrEOL("\n\r\n", "\n");// print the request but stop on \n\r\n and add a \n afterwards.
}
//use a StringParser object to search for a double EOL, which signifies the end of
//the header.
/* 下面要查找client发出的RTSP Request Header的末尾处 */
/* 找到fRequest末端了吗? */
Bool16 weAreDone = false;
StringParser headerParser(&fRequest);
UInt16 lcount = 0;
/* 当遇到eol时,fStartGet指针越过它 */
while (headerParser.GetThruEOL(NULL))
{
lcount++;
/* 当当前的fStartGet指针指向EOL时 */
if (headerParser.ExpectEOL())
{
//The legal end-of-header sequences are \r\r, \r\n\r\n, & \n\n. NOT \r\n\r!
//If the packets arrive just a certain way, we could get here with the latter
//combo(组合,即\r\n\r), and not wait for a final \n.
/* 假如查找到"\r\n\r",就继续查找,直至找到符合条件的末端 */
if ((headerParser.GetDataParsedLen() > 2) &&
(memcmp(headerParser.GetCurrentPosition() - 3, "\r\n\r", 3) == 0))
continue;
/* 标记找到了 */
weAreDone = true;
break;
}
/* 假如是"xxxxxx\r" */
else if (lcount == 1) {
// if this request is actually a ShoutCast password it will be
// in the form of "xxxxxx\r" where "xxxxx" is the password.
// If we get a 1st request line ending in \r with no blanks we will
// assume that this is the end of the request.
UInt16 flag = 0;
UInt16 i = 0;
/* 检查"xxxxxx\r"中有无空格?没有就说明我们找到了 */
for (i=0; i<fRequest.Len; i++)
{
if (fRequest.Ptr[i] == ' ')
flag++;
}
if (flag == 0)
{
weAreDone = true;
break;
}
}
}
//weAreDone means we have gotten a full request
/* 我们找到了一个Full RTSP Request Header? */
if (weAreDone)
{
//put back any data that is not part of the header
fRequest.Len -= headerParser.GetDataRemaining();
fRetreatBytes += headerParser.GetDataRemaining();
fRequestPtr = &fRequest;
return QTSS_RequestArrived;
}
//check for a full buffer
/* 当到达Request buffer末端时,给出提示信息E2BIG */
if (fCurOffset == kRequestBufferSizeInBytes - 1)
{
fRequestPtr = &fRequest;
return E2BIG;
}
}
}
