/* Create an RTSP Request */
static int initializeRtspRequest(PRTSP_MESSAGE msg, char* command, char* target)
{
char sequenceNumberStr[16];
char clientVersionStr[16];
// FIXME: Hacked CSeq attribute due to RTSP parser bug
createRtspRequest(msg, NULL, 0, command, target, "RTSP/1.0",
0, NULL, NULL, 0);
sprintf(sequenceNumberStr, "%d", currentSeqNumber++);
sprintf(clientVersionStr, "%d", rtspClientVersion);
if (!addOption(msg, "CSeq", sequenceNumberStr) ||
!addOption(msg, "X-GS-ClientVersion", clientVersionStr)) {
freeMessage(msg);
return 0;
}
return 1;
}
// Given an RTSP message string rtspMessage, parse it into an RTSP_MESSAGE struct msg
int parseRtspMessage(PRTSP_MESSAGE msg, char* rtspMessage, int length) {
char* token;
char* protocol;
char* endCheck;
char* target;
char* statusStr;
char* command;
char* sequence;
char flag;
char messageEnded = 0;
char* payload = NULL;
char* opt = NULL;
int statusCode = 0;
int sequenceNum;
int exitCode;
POPTION_ITEM options = NULL;
POPTION_ITEM newOpt;
// Delimeter sets for strtok()
char* delim = " \r\n";
char* end = "\r\n";
char* optDelim = " :\r\n";
char typeFlag = TOKEN_OPTION;
// Put the raw message into a string we can use
char* messageBuffer = malloc(length + 1);
if (messageBuffer == NULL) {
exitCode = RTSP_ERROR_NO_MEMORY;
goto ExitFailure;
}
memcpy(messageBuffer, rtspMessage, length);
// The payload logic depends on a null-terminator at the end
messageBuffer[length] = 0;
// Get the first token of the message
token = strtok(messageBuffer, delim);
if (token == NULL) {
exitCode = RTSP_ERROR_MALFORMED;
goto ExitFailure;
}
// The message is a response
if (startsWith(token, "RTSP")) {
flag = TYPE_RESPONSE;
// The current token is the protocol
protocol = token;
// Get the status code
token = strtok(NULL, delim);
statusCode = atoi(token);
if (token == NULL) {
exitCode = RTSP_ERROR_MALFORMED;
goto ExitFailure;
}
// Get the status string
statusStr = strtok(NULL, end);
if (statusStr == NULL) {
exitCode = RTSP_ERROR_MALFORMED;
goto ExitFailure;
}
// Request fields - we don't care about them here
target = NULL;
command = NULL;
}
// The message is a request
else {
flag = TYPE_REQUEST;
command = token;
target = strtok(NULL, delim);
if (target == NULL) {
exitCode = RTSP_ERROR_MALFORMED;
goto ExitFailure;
}
protocol = strtok(NULL, delim);
if (protocol == NULL) {
exitCode = RTSP_ERROR_MALFORMED;
goto ExitFailure;
}
// Response field - we don't care about it here
statusStr = NULL;
}
if (strcmp(protocol, "RTSP/1.0")) {
exitCode = RTSP_ERROR_MALFORMED;
goto ExitFailure;
}
// Parse remaining options
while (token != NULL)
{
token = strtok(NULL, typeFlag == TOKEN_OPTION ? optDelim : end);
if (token != NULL) {
if (typeFlag == TOKEN_OPTION) {
opt = token;
}
// The token is content
else {
// Create a new node containing the option and content
newOpt = (POPTION_ITEM)malloc(sizeof(OPTION_ITEM));
if (newOpt == NULL) {
freeOptionList(options);
exitCode = RTSP_ERROR_NO_MEMORY;
goto ExitFailure;
}
newOpt->flags = 0;
newOpt->option = opt;
newOpt->content = token;
newOpt->next = NULL;
insertOption(&options, newOpt);
// Check if we're at the end of the message portion marked by \r\n\r\n
// endCheck points to the remainder of messageBuffer after the token
endCheck = &token[0] + strlen(token) + 1;
// See if we've hit the end of the message. The first \r is missing because it's been tokenized
if (startsWith(endCheck, "\n\r\n")) {
// We've encountered the end of the message - mark it thus
messageEnded = 1;
// The payload is the remainder of messageBuffer. If none, then payload = null
if (endCheck[3] != '\0')
payload = &endCheck[3];
break;
}
}
}
typeFlag ^= 1; // flip the flag
}
// If we never encountered the double CRLF, then the message is malformed!
if (!messageEnded) {
exitCode = RTSP_ERROR_MALFORMED;
goto ExitFailure;
}
// Get sequence number as an integer
sequence = getOptionContent(options, "CSeq");
if (sequence != NULL) {
sequenceNum = atoi(sequence);
}
else {
sequenceNum = SEQ_INVALID;
}
// Package the new parsed message into the struct
if (flag == TYPE_REQUEST) {
createRtspRequest(msg, messageBuffer, FLAG_ALLOCATED_MESSAGE_BUFFER | FLAG_ALLOCATED_OPTION_ITEMS, command, target,
protocol, sequenceNum, options, payload, payload ? length - (int)(messageBuffer - payload) : 0);
}
else {
createRtspResponse(msg, messageBuffer, FLAG_ALLOCATED_MESSAGE_BUFFER | FLAG_ALLOCATED_OPTION_ITEMS, protocol, statusCode,
statusStr, sequenceNum, options, payload, payload ? length - (int)(messageBuffer - payload) : 0);
}
return RTSP_ERROR_SUCCESS;
ExitFailure:
if (options) {
free(options);
}
if (messageBuffer) {
free(messageBuffer);
}
return exitCode;
}