//Starts the server and listens for connections
void Server::start(){
//check if directory exists
//If it doesn't , try to create the directory
char temp[1024];
//Get address info purposes
struct sockaddr_storage otherAddr, otherAddr2; //Connectors address information
socklen_t otherAddrLen, otherAddrLen2;
int rv;
int i;
//Socket purposes
int newfd;
int newfd2;
//port numbers
unsigned short dataPort;
//Handling child processes
struct sigaction sa;
//Char buffers
char buffer[DATA_SIZE];
//String vector
vector<string> tokens;
//extra string(s)
string errMsg = INVCOM;
//Copy the string into character array
//since chdir() takes char * as argument
strncpy( temp, rootDir.c_str() , sizeof(temp) );
temp[ sizeof(temp) - 1 ] = 0;
//Check if directory is valid
//If no directory create one
if( !validDir(temp) ){
if( mkdir(temp, 0777) != 0 ){
perror("mkdir");
exit(1);
}
}
//change directory
//call chdir()
if(chdir(temp) != 0){
//If chdir fails
perror("chdir");
exit(1);
}
if ( !getPWD() ){
cout << "Unable to get cwd" << endl;
exit(1);
}
//We have now changed the program's pwd to root directory
//Now create a socket and bind to the control port and start listening
//for connections
cs = controlSock = createSocket( controlPort);
if(verbose)
cout << "Control socket created" << endl;
ds = dataSock = createSocket("0");
if(verbose)
cout << "Data socket created" << endl;
dataPort = getPort(dataSock);
//Now we have successfully created the socket
//and bound it to the control port
//Start listening for connections
//Entering the listening loop
if ( listen (controlSock , BACKLOG) != 0 ) {
perror("listen");
close(controlSock);
exit(1);
}
if( listen(dataSock , BACKLOG) != 0 ){
perror("listen");
close(dataSock);
exit(1);
}
//handle dead processes
sa.sa_handler = sigchldHandler; //read all dead processes
sigemptyset( &sa.sa_mask );
sa.sa_flags = SA_RESTART;
if( sigaction( SIGCHLD, &sa , NULL ) == -1 ){
perror("sigaction");
exit(1);
}
//Handle user interrupts
signal(SIGINT, userIntHandler);
cout << "Waiting for connections ... " << endl;
while(1){
otherAddrLen = sizeof ( otherAddr) ;
newfd = accept ( controlSock , (struct sockaddr *) &otherAddr , &otherAddrLen );
cout << "Connection from " << getIPFromAddr(&otherAddr) << ":" << getPortFromAddr(&otherAddr) << endl;
commsock = newfd;
send(newfd, (unsigned short *)&dataPort, 2, 0);
otherAddrLen2 = sizeof otherAddr2;
newfd2 = accept(dataSock, (struct sockaddr *) &otherAddr2, &otherAddrLen2 );
datacommsock = newfd2;
cout << "Connection to data socket from client port " << getPortFromAddr(&otherAddr2) << endl;
if( fork() == 0 ){
//The code in this block is executed by the child process
close(controlSock); //Child doesn't require the control socket
close(dataSock);
if(verbose){
cout << "Closing listener sockets" << endl;
cout << "Child process created for communication with client" << endl;
}
if (dup2( newfd , 0 ) != 0 ){
perror("dup2");
exit(1);
}
do{
if(fgets( buffer, DATA_SIZE, stdin ) == NULL){
close(newfd);
exit(1);
}
//Remove carriage return and new line characters
for(rv = 0; rv < DATA_SIZE ; rv++){
if(buffer[rv] == '\r'){
buffer[rv] = 0;
break;
}
if(buffer[rv] == '\n'){
buffer[rv] = 0;
break;
}
}
//Read buffer and find what command it is
//Call the corresponding method
string s(buffer); //convert the character array into string
if(verbose){
cout << "Received command " + s << endl;
}
istringstream iss(s);
//copy the tokens into the string vector
copy( istream_iterator<string>(iss),
istream_iterator<string>() ,
back_inserter<vector<string> >(tokens) );
//Copied the tokens into tokens
rv = tokens.size();
if(rv > 0){
//If there is atleast one word
if(tokens[0].compare("ls") == 0){
//The client requested a file listing
ls(s, newfd2);
}
else if(tokens[0].compare("quit") == 0){
//The client closed the connection
break;
}
else if(tokens[0].compare("cd") == 0){
//The client requested a directory change
if(rv == 2){
cd(tokens[1], newfd2);
}
else{
sendMessage( errMsg.c_str() , errMsg.length() , ERROR, NF, dataSock );
}
}
else if( tokens[0].compare("pwd") == 0 ){
//Client requested a pwd
PWD(newfd2);
}
else if(tokens[0].compare("get") == 0){
string temp="";
for(i=1; i < rv;i++){
temp = temp + tokens[i] + " ";
}
temp = temp.substr(0, temp.length()-1 );
getFile(temp, newfd2);
}
else if(tokens[0].compare("put") == 0){
string temp="";
for(i=1; i < rv;i++){
temp = temp + tokens[i] + " ";
}
temp = temp.substr(0, temp.length()-1 );
putFile(temp, newfd2);
}
else{
sendMessage( errMsg.c_str() , errMsg.length() , ERROR, NF, newfd2 );
}
}
tokens.clear(); //clear the tokens
}while (1);
//The client closed the connection
//So, close the socket and quit the child process
close(newfd);
close(newfd2);
cout << "Connection closed" << endl;
exit(1);
}
close(newfd);
}
close(controlSock);
}
int main(int argc, char** argv)
{
// create master socket in core OS and return file descriptor
int masterFD = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
// socket settings
struct sockaddr_in sAddr;
sAddr.sin_family = AF_INET;
sAddr.sin_port = htons(12345);
sAddr.sin_addr.s_addr = htonl(INADDR_ANY);
bind(masterFD, (struct sockaddr *)(&sAddr), sizeof(sAddr));
// nonblock socket - do not wait all data
// read any and continue
set_nonblock(masterFD);
//listen as server ip and port from settings
listen(masterFD, SOMAXCONN);
std::cout << "master begin listen with FD = " << masterFD << std::endl;
// create poll in OS core and return file descriptor
// poll for correct work with slave socket`s
int EPollFD = epoll_create1(0);
struct epoll_event Event;
Event.data.fd = masterFD;
Event.events = EPOLLIN;// catch read event, all unread data generate new event
// register Event listener in control
epoll_ctl(EPollFD,EPOLL_CTL_ADD,masterFD,&Event);
std::map<unsigned int,std::string> slaveSockets;
while (true)
{
struct epoll_event Events[MaxReceivedEvents];
// receive N events
int N = -1;
std::cout << "begin wait event..." << std::endl;
// if N < 0 - core signal error - repeat wait
while(true){
N = epoll_wait(EPollFD,Events,MaxReceivedEvents,-1);
if (N >= 0)
break;
}
std::cout << "wait terminated..." << std::endl;
for (int i = 0; i < N; ++i)
{
// new connection
if (Events[i].data.fd == masterFD){
//slave ip
struct sockaddr_in slaveAddr; socklen_t slaveAddrSize = sizeof(slaveAddr);
//register new connection
int slaveFD = accept(masterFD, (sockaddr*)&slaveAddr, &slaveAddrSize);
set_nonblock(slaveFD);
struct epoll_event Event;
Event.data.fd = slaveFD;
Event.events = EPOLLIN;// catch read event, all unread data generate new event
// register slave Event listener in control
epoll_ctl(EPollFD,EPOLL_CTL_ADD,slaveFD,&Event);
char * ip = getIPFromAddr(slaveAddr);
//save to chat list
slaveSockets.insert(std::pair<unsigned int,std::string> (slaveFD, ip));
std::cout << "slave connected with FD = " << slaveFD
<< " AND slAddr = " << ip // << " || "
//<< slaveAddr.sin_addr << " || "
//<< slaveAddr.sin_port
<< std::endl;
} else
// read data
{
auto receiver = slaveSockets.find(Events[i].data.fd);
if (receiver == slaveSockets.end()){
continue;
}
static char Buffer[MaxMessageLength];
int reciveResult = recv(Events[i].data.fd,Buffer,MaxMessageLength,MSG_NOSIGNAL);
//connection closed
if ((reciveResult == 0) && (errno != EAGAIN)){
//close connection
shutdown(Events[i].data.fd,SHUT_RDWR);
close(Events[i].data.fd);
//delete from listener
slaveSockets.erase(Events[i].data.fd);
std::cout << "slave disconnected with FD = " << Events[i].data.fd << std::endl;
} else
//read data from slave
if (reciveResult > 0){
int authorLength = receiver->second.length() + 4;
char* ResBuffer = new char[reciveResult + authorLength];
strcpy(ResBuffer,receiver->second.c_str());
strcat(ResBuffer," || ");
std::cout << "server receive message from slave with FD = " << Events[i].data.fd
<< " || message = " << Buffer
<< " || author = " << ResBuffer
<< std::endl;
strcat(ResBuffer,Buffer);
std::cout << "resultBuffer" << ResBuffer << std::endl;
//translate message to all listener
for (auto it = slaveSockets.begin(); it != slaveSockets.end();++it){
if (it->first != (unsigned int)Events[i].data.fd){
send(it->first,ResBuffer,reciveResult + authorLength,MSG_NOSIGNAL);
}
}
delete [] ResBuffer;
}
}
}
}
return 0;
}
