/**
* Starts the server and transits into daemon mode, if not in debug mode.
* Loops forever, accepting stream (TCP) connections.
* Child is forked when a client connects.
*
* @param flag user-provided flags.
*/
void
run_server(struct flags* flag)
{
int server_sock;
/* start listening for clients */
server_sock = setup_server_socket(flag);
/* attach signal handlers */
if (signal(SIGCHLD, server_sig_handler) == SIG_ERR) {
err(EXIT_FAILURE, "cannot catch SIGCHLD");
}
if (signal(SIGHUP, server_sig_handler) == SIG_ERR) {
err(EXIT_FAILURE, "cannot catch SIGCHUP");
}
/* Start accepting connections */
listen(server_sock, BACKLOG);
/* daemonize if not in debug mode */
if (!flag->dflag) {
if (daemon(1, 1) < 0) {
errx(EXIT_FAILURE, "cannot transit into daemon mode");
}
}
/* Handle clients */
do {
accept_client(flag, server_sock);
} while (1);
close(server_sock);
}
void run(global_config_struct *global_config) {
global_resources_struct global_resources;
setup_server_socket(global_config, &global_resources);
global_resources.bases.transfer_buffer_size = global_config->transfer_buffer_size;
setup_events(&global_resources);
listen_server_socket(&global_resources);
dispatch(&global_resources);
close_all(&global_resources);
}
//-- main() ///{{{1///////////////////////////////////////////
int main( int argc, char* argv[] )
{
int serverPort = kServerPort;
fd_set readfds;
fd_set writefds;
int maxFd, activity, sd;
std::vector<ConnectionData> connections;
// Did the user specify a port?
if( 2 == argc )
{
serverPort = atoi(argv[1]);
}
# if VERBOSE
printf( "Attempting to bind to port %d\n", serverPort );
# endif
// Set up listening socket - see setup_server_socket() for details.
int listenfd = setup_server_socket( serverPort );
if( -1 == listenfd )
return 1;
// loop forever
while( 1 )
{
FD_ZERO(&readfds); // Clear the read socket set
FD_ZERO(&writefds); // Clear the read socket set
FD_SET(listenfd, &readfds); // Add the listen socket to the read set
maxFd = listenfd; // Initially add the listen socket as the maximum file descriptor
// Add the client descriptors to the set.
for(size_t i = 0; i < connections.size(); i++){
sd = connections[i].sock;
if(sd > 0){
if(connections[i].state == eConnStateReceiving) //Add connections to the corresponding sets
FD_SET(sd, &readfds);
else if(connections[i].state == eConnStateSending)
FD_SET(sd, &writefds);
}
if(sd > maxFd){ // Change maxFd if the file descriptor of the client is larger than the current maxium
maxFd = sd;
}
}
activity = select(maxFd + 1, &readfds, &writefds, NULL, NULL); // Perform select to find pending reads and writes
if((activity < 0) && (errno != EINTR)){ // Check so that no errors occured.
printf("select error \n"); // Should we have "else"
}
if(FD_ISSET(listenfd, &readfds)){ // If there is activity on the listening socket
// Accept connection and add it to the list.
if(acceptConnection(&connections, listenfd) == -1)
continue;
continue;
}
// Loop through all connections and check if they members of a set
for(size_t i=0; i<connections.size(); i++){
sd = connections[i].sock; //Copy the socket descriptor
bool processFurther = true;
if(FD_ISSET(sd, &readfds)){
while( processFurther && connections[i].state == eConnStateReceiving )
processFurther = process_client_recv( connections[i] );
}
else if(FD_ISSET(sd, &writefds)){
while( processFurther && connections[i].state == eConnStateSending )
processFurther = process_client_send( connections[i] );
}
if(!processFurther){ // Close the socket if processing is finished
close(connections[i].sock);
connections[i].sock = -1;
}
}
//Erase all invalid connections
connections.erase(std::remove_if(connections.begin(),
connections.end(), &is_invalid_connection),connections.end());
}
// The program will never reach this part, but for demonstration purposes,
// we'll clean up the server resources here and then exit nicely.
close( listenfd );
return 0;
}
// Construct a server socket.
// @bind_addr A numeric IP address to be bound, or `NULL`.
// @port TCP port number to be bound.
// @on_accept Callback function.
// @freebind true to turn on IP_FREEBIND socket option.
//
// This creates a socket and bind it to the given address and port.
// If `bind_addr` is `NULL`, the socket will listen on any address.
// Both IPv4 and IPv6 addresses are supported.
//
// For each new connection, `on_accept` is called to determine
// if the new connection need to be closed immediately or
// to be added to the reactor. If `on_accept` returns an empty
// <std::unique_ptr>, the new connection is closed immediately.
// Otherwise, the new connection is added to the reactor.
tcp_server_socket(const char* bind_addr, std::uint16_t port,
wrapper on_accept, bool freebind):
resource( setup_server_socket(bind_addr, port, freebind) ),
m_wrapper(on_accept) {}
//-- main() ///{{{1///////////////////////////////////////////
int main( int argc, char* argv[] )
{
int serverPort = kServerPort;
// did the user specify a port?
if( 2 == argc )
{
serverPort = atoi(argv[1]);
}
# if VERBOSE
printf( "Attempting to bind to port %d\n", serverPort );
# endif
// set up listening socket - see setup_server_socket() for details.
int listenfd = setup_server_socket( serverPort );
if( -1 == listenfd )
return 1;
// loop forever
while( 1 )
{
sockaddr_in clientAddr;
socklen_t addrSize = sizeof(clientAddr);
// accept a single incoming connection
int clientfd = accept( listenfd, (sockaddr*)&clientAddr, &addrSize );
printf("Accepted a new client.. \n");
if( -1 == clientfd )
{
perror( "accept() failed" );
continue; // attempt to accept a different client.
}
# if VERBOSE
// print some information about the new client
char buff[128];
printf( "Connection from %s:%d -> socket %d\n",
inet_ntop( AF_INET, &clientAddr.sin_addr, buff, sizeof(buff) ),
ntohs(clientAddr.sin_port),
clientfd
);
fflush( stdout );
# endif
# if NONBLOCKING
// enable non-blocking sends and receives on this socket
if( !set_socket_nonblocking( clientfd ) )
continue;
# endif
// initialize connection data
ConnectionData connData;
memset( &connData, 0, sizeof(connData) );
connData.sock = clientfd;
connData.state = eConnStateReceiving;
// Repeatedly receive and re-send data from the connection. When
// the connection closes, process_client_*() will return false, no
// further processing is done.
bool processFurther = true;
while( processFurther )
{
while( processFurther && connData.state == eConnStateReceiving )
processFurther = process_client_recv( connData );
while( processFurther && connData.state == eConnStateSending )
processFurther = process_client_send( connData );
}
// done - close connection
close( connData.sock );
}
// The program will never reach this part, but for demonstration purposes,
// we'll clean up the server resources here and then exit nicely.
close( listenfd );
return 0;
}