/*Handle Client Request Function
Variable Definition:
-- client_socket: socket connected to the client
Return Value: NULL
*/
void handleClientRequest(int client_socket) {
FILE *channel; //file stream for client socket
char request_line[STRING_SIZE]; //client request line
char *return_value; //each line header pointer
//Initialize request_line buffer
memset(request_line, 0, STRING_SIZE);
//Create an input stream from the socket
channel = fdopen(client_socket, "r");
if (channel == NULL) {
dieWithSystemMessage("fdopen() failed");
}
//Get client Request Line (Jump the blank line)
do {
return_value = fgets(request_line, STRING_SIZE, channel);
} while (syntaxChecking(return_value, BLANK_LINE));
//Output the client_socket id and Request Line
printf("Got a call on %d: request = %s", client_socket, request_line);
//Get client Header Lines & Response the client request
respondClientRequest(request_line, getHeaderLines(channel), client_socket);
//Close client socket
close(client_socket);
//Close file stream
fclose(channel);
return;
}
bool headerLinesIncorrect(RTSP_HEADER *header, char *field_value){
RTSP_HEADER *node;
for (node = header->next; node != NULL; node = node->next) {
//Use regular expression to check header lines' syntax
if (!syntaxChecking(node->header_line, HEADER_LINE)) {
sprintf(field_value, "Header line: [%s] is syntacically incorrect!", node->header_line);
return true;
}
}
return false;
}
/*Respond Client Request Function
Variable Definition:
-- request: client request line
-- header: client header lines
-- client_socket: socket connected to the client
Return Value: NULL
*/
void respondClientRequest(char *request, RTSP_HEADER *header, int client_socket) {
char method[STRING_SIZE]; //method field: SETUP, PLAY, PAUSE, or TEARDOWN
char url[STRING_SIZE]; //url field: for example, rtsp://localhost:5678/movie.Mjpeg
char version[STRING_SIZE]; //rtsp version field: RTSP/1.0
char field_value[HALFBUF_SIZE]; //field value string
u_int32 cseq_number = 0; //cseq number
//Initialize method, url, version, and field_value buffer
memset(method, 0, STRING_SIZE);
memset(url, 0, STRING_SIZE);
memset(version, 0, STRING_SIZE);
memset(field_value, 0, HALFBUF_SIZE);
//Test the client RTSP Request Line
if (!syntaxChecking(request, REQUEST_LINE)) {
//400 Bad Request: the request could not be understood by the server
sendBadRequest("Request Line is syntactically incorrect!", client_socket);
return;
}
//Get the method, url, and rtsp version
sscanf(request, "%s%s%s", method, url, version);
//Decode the URL(if it has %HEX code)
decodeURL(url);
//Test the method
if (methodNotAllow(method)) {
//405 Method Not Allowed: the method field is neither "SETUP", "PLAY", "PAUSE" nor "TEARDOWN"
sendMethodNotAllowed(method, client_socket);
return;
}
//Test the Requested URL
else if (!syntaxChecking(url, URL_FORMAT)) {
//400 Bad Request: the request could not be understood by the server
sendBadRequest("Requested URL is syntactically incorrect!", client_socket);
return;
}
//Test the RTSP version
else if (!syntaxChecking(version, RTSP_VERSION)) {
//400 Bad Request: the request could not be understood by the server
sendBadRequest("RTSP Version is syntactically incorrect!", client_socket);
return;
}
//Test the RTSP version 1.0
else if (!syntaxChecking(version, RTSP_VERSION_1)) {
//505 RTSP Version Not Supported: the requested RTSP protocol version is not supported by server
sendRTSPVersionNotSupported(version, client_socket);
return;
}
#ifdef DEBUG
RTSP_HEADER *debug_header_node;
DEBUG_START;
fputs("RTSP request header lines:\n", stdout);
//Output the RTSP request header lines
for (debug_header_node = header->next; debug_header_node != NULL; debug_header_node = debug_header_node->next) {
fputs(debug_header_node->field_name, stdout);
fputs(": ", stdout);
fputs(debug_header_node->field_value, stdout);
fputc('\n', stdout);
}
DEBUG_END;
#endif
//Test the Header Line
if (headerLinesIncorrect(header, field_value)) {
//400 Bad Request: the request could not be understood by the server
sendBadRequest(field_value, client_socket);
return;
}
//Test the "CSeq" field
else if (fieldNotExist(header, "cseq", field_value)) {
//400 Bad Request: the request could not be understood by the server
sendBadRequest("CSeq field does not exist!", client_socket);
return;
}
//Test the "Session" field
else if ((!methodIsSetup(method)) && fieldNotExist(header, "session", field_value)) {
//400 Bad Request: the request could not be understood by the server
sendBadRequest("Session field does not exist!", client_socket);
return;
}
//Test the "Transport" field
else if (methodIsSetup(method) && fieldNotExist(header, "transport", field_value)) {
//400 Bad Request: the request could not be understood by the server
sendBadRequest("Transport field does not exist!", client_socket);
return;
}
//Test the "Range" field
else if ((!(fieldNotExist(header, "range", field_value)))
&& (!syntaxChecking(field_value, RANGE_FORMAT))) {
//400 Bad Request: the request could not be understood by the server
sendBadRequest("Range field value(npt=number[-number]) is syntactically incorrect!", client_socket);
return;
}
//Test the "If-Modified-Since" field
else if ((!(fieldNotExist(header, "if-modified-since", field_value)))
&& (!syntaxChecking(field_value, TIME_FORMAT))) {
//400 Bad Request: the request could not be understood by the server
sendBadRequest("If-Modified-Since field value(time format) is syntactically incorrect!", client_socket);
return;
}
//Now we are sure that the request message is SYNTACTICALLY CORRECT
//Get the Requested File or Directory's name
pathBelowCurrentDirectory(url);
printf("Requested File or Directory is %s\n", url);
//Test the requested file on the server
if (urlNotExist(url)) {
//404 Not Found: the requested document does not exist on this server
sendNotFound(url, client_socket);
return;
}
//Test the requested url is a directory
else if (urlIsADirectory(url)) {
//404 Not Found: the requested document does not exist on this server
sendNotFound(url, client_socket);
return;
}
//Test the method is valid in special state
else if (methodIsNotValidInState(method)) {
//455 Method is not valid in this state: the method is not valid in this state
sendMethodNotValidInThisState(method, client_socket);
return;
}
//Get the RTSP Request Message information
cseq_number = getRTSPInfo(header);
//Test the "Session" field's value
if (cseq_number == 0) {
//454 Session Not Found: the session id is not equal to the server's
sendSessionNotFound(client_socket);
return;
}
//Test the protocol type
else if (strcmp(protocol_type, PROTOCOL_TYPE) != 0) {
//461 Unsupported Transport: the transport protocol is not supported by the server
sendUnsupportedTransport(protocol_type, client_socket);
return;
}
//Test the "If-Modified-Since" field
else if (fieldNotExist(header, "if-modified-since", field_value)) {
//200 OK: the request is good
sendOK(url, method, cseq_number, client_socket);
return;
}
//Test the "If-Modified-Since" field value
else if (compareModifiedTime(url, field_value)) {
//304 Not Modified: the request does not Modified since If-Modified-Since field
sendNotModified(url, cseq_number, client_socket);
return;
}
else {
//200 OK: the request is good
sendOK(url, method, cseq_number, client_socket);
return;
}
}
/*Respond Client Request Function
Variable Definition:
-- request: client request line
-- header: client header lines
-- client_socket: socket connected to the client
Return Value: NULL
*/
void respondClientRequest(char *request, struct http_header *header, int client_socket){
char method[STRING_SIZE]; //method field: GET or HEAD
char url[STRING_SIZE]; //url field: /TestServer
char version[STRING_SIZE]; //http version field: HTTP/1.1
char field_value[HALFBUF_SIZE]; //field value string
bool modified_signal; //whether if-modified-since field exist
//Initialize method, url and version buffer
memset(method, 0, STRING_SIZE);
memset(url, 0, STRING_SIZE);
memset(version, 0, STRING_SIZE);
memset(field_value, 0, HALFBUF_SIZE);
//Test the client HTTP Request Line
if (!syntaxChecking(request, 'R')){
//400 Bad Request: the request could not be understood by the server
sendBadRequest("Request Line is syntactically incorrect!", client_socket);
return;
}
//Get the method, url, and http version
// NC: i don't think this works: need sscanf(request, "%s %s %s", method, url, version);
sscanf(request, "%s%s%s", method, url, version);
//Decode the URL(if it has %HEX code)
decodeURL(url);
//Test the method
if ((strcmp(method, "GET") != 0) && (strcmp(method, "HEAD") != 0)){
//405 Method Not Allowed: the method field is neither "GET" nor "HEAD"
sendMethodNotAllowed(method, client_socket);
return;
}
//Test the Requested URL
else if (!syntaxChecking(url, 'U')){
// NC: but, "the only legal Request-URI is the abs_path “/TestServer”. Generate a 404 Response to all other Request-URIs."
// #17: -1
//400 Bad Request: the request could not be understood by the server
sendBadRequest("Requested URL is syntactically incorrect!", client_socket);
return;
}
//Test the HTTP version
else if (!syntaxChecking(version, 'V')){
//400 Bad Request: the request could not be understood by the server
sendBadRequest("HTTP Version is syntactically incorrect!", client_socket);
return;
}
else if (!syntaxChecking(version, 'O')){
//505 HTTP Version Not Supported: the requested HTTP protocol version is not supported by server
sendHTTPVersionNotSupported(version, client_socket);
return;
}
//Test the Header Line
if (headerLinesIncorrect(header, field_value)){
//400 Bad Request: the request could not be understood by the server
sendBadRequest(field_value, client_socket);
return;
}
//Test the "Host" field
else if (fieldNotExist(header, "host", field_value)){
//400 Bad Request: the request could not be understood by the server
sendBadRequest("Host field does not exist!", client_socket);
return;
}
else if (!syntaxChecking(field_value, 'I')){
//400 Bad Request: the request could not be understood by the server
sendBadRequest("Host field value(domain name, IP address, or port format) is syntactically incorrect!", client_socket);
return;
}
//Test the "If-Modified-Since" field
else if ((!(modified_signal = fieldNotExist(header, "if-modified-since", field_value))) && (!syntaxChecking(field_value, 'T'))){
//400 Bad Request: the request could not be understood by the server
sendBadRequest("If-Modified-Since field value(time format) is syntactically incorrect!", client_socket);
return;
}
//Now we are sure that the request message is SYNTACTICALLY CORRECT
//Get the Requested File or Directory's name
pathBelowCurrentDirectory(url);
printf("Requested File or Directory is %s\n", url);
// NC: but OUR server doesn't do this
//Test the requested file on the server
if (urlNotExist(url)){
//404 Not Found: the requested document does not exist on this server
sendNotFound(url, client_socket);
}
else if (urlIsADirectory(url)){
//List the File Name of Directory
sendFileNameInDirectory(url, method, client_socket);
}
else if (modified_signal){
//200 OK: the request is good
sendOK(url, method, client_socket);
}
else if (compareModifiedTime(url, field_value)){
//304 Not Modified: the request does not Modified since If-Modified-Since field
sendNotModified(url, client_socket);
}
else{
//200 OK: the request is good
sendOK(url, method, client_socket);
}
return;
}
