unisa_lab_reti_2013_2014/7.client-server-select (COMPLETE)/daytimesrv.c

#include	"../basic.h"
#include	<time.h>

void sigpipeaction (int signal){
    
    //fprintf(stderr, "Sigpipe catturato\n");
    
}

typedef struct message {
	char data[100];
}t_message;


int main(int argc, char **argv) {

	int			listenfd, connfd, n;
	struct sockaddr_in	servaddr;
	struct sockaddr_in client_address_struct;
	unsigned int client_address_struct_size = sizeof (client_address_struct);
	

//////////////////////////////////////////////////////////// SIGNALS

///////SIGPIPE
struct sigaction sigpipestructure;
    sigpipestructure.sa_handler = sigpipeaction;
    sigpipestructure.sa_flags = 0;
    
sigaction (SIGPIPE, &sigpipestructure, NULL);
//////////////////////////////////////////////////////////// END SIGNALS
		

	if (argc != 2 ){
		printf("usage: daytimesrv <porta>\n");
		exit(0);
	}
	if( (listenfd = socket(AF_INET, SOCK_STREAM, 0)) < 0){
		printf("socket error\n");
		exit(0);
	}
	bzero(&servaddr, sizeof(servaddr));
	servaddr.sin_family      = AF_INET;
	servaddr.sin_addr.s_addr = htonl(INADDR_ANY);   /* wildcard address */
	servaddr.sin_port        = htons(atoi(argv[1])); /* server port */

	if( (bind(listenfd, (struct sockaddr *) &servaddr, sizeof(servaddr))) < 0){
		printf("bind error\n"); exit(0);
	}
	if( listen(listenfd, 5) < 0 ){
		printf("listen error\n");
		exit(0);
	}
		
	
	
	fd_set  fd_set_1;
	FD_ZERO(&fd_set_1);
	/*
	void FD_CLR(int fd, fd_set *set);
       int  FD_ISSET(int fd, fd_set *set);
       void FD_SET(int fd, fd_set *set);
       void FD_ZERO(fd_set *set);
       */
	
	struct timeval timer;
		timer.tv_sec = 99999999;
		timer.tv_usec = 0;


	int clients [FD_SETSIZE - 3];
	int i;
	for (i= 0;i< (FD_SETSIZE - 3);i++){
		*(clients + i) = -1 ;
	}
	
	//  FD_SET(fileno(stdin),&fd_set_1); // control stdin (fileno = 0)
	
	// add listenfd to monitor listen socket
	FD_SET(listenfd,&fd_set_1);
	fprintf(stdout,"Added listen socket %d to monitor\n",listenfd );
	int max_fd = listenfd + 1;
	
	t_message m;
	fd_set backup_set;

	for ( ; ; ) {
		
		 
		
		fprintf(stdout,"waiting for non blocking fds\n");
		int ready_fds_to_read = 0;
		backup_set = fd_set_1;
		for (ready_fds_to_read = select( max_fd, &fd_set_1, NULL,NULL,&timer);
			     ready_fds_to_read <= 0 ;
			     ready_fds_to_read = select( max_fd, &fd_set_1, NULL,NULL,&timer)){
				
				if (ready_fds_to_read == -1 && errno == EINTR ){ continue;}
				if (ready_fds_to_read ==  0) {timer.tv_sec = 99999999;continue;}
				// write code to inform client that server has an internal error
				exit(0);
				
		}// wait for nonblocking fd in read set
		fprintf(stdout,"ready: %d\n",ready_fds_to_read);
		int flag = 0;
		if (FD_ISSET(listenfd,&fd_set_1)){
			ready_fds_to_read--;
			for ( ; ; ) {
				if( (connfd = accept(listenfd, (struct sockaddr *) &client_address_struct, &client_address_struct_size)) < 0)
				{
					if(errno == EINTR )
						continue;
					printf("accept error on listening socket\n");
					flag = 1;
					break;
				}
				break;
			}
			if (flag == 0){
				
				/// operations on connfd
				int free = 0;
				for (i= 0;i< (FD_SETSIZE - 3);i++){
					if (*(clients + i) == -1) {*(clients + i) = connfd; free = 1; break;} 
				}
				if (free == 0){
					shutdown (connfd, SHUT_RDWR);
					fprintf(stdout,"Can't server %d. Too many connected clients\n",connfd );
					
				}else {
					FD_SET(connfd,&backup_set);
					max_fd = MAX(connfd + 1, max_fd);
					fprintf(stdout,"Added connection socket %d to monitor\n",connfd );
				}
			}
		}
		
		
		// operations on other ready to read sockets in select

		int ready_fd, ready_fd_index;
		for (i= 0; i< (FD_SETSIZE - 3)  &&  ready_fds_to_read>0; i++){
			
			if (  *(clients + i) != -1     &&    FD_ISSET(*(clients + i),&fd_set_1)){
				ready_fds_to_read--;
				ready_fd = *(clients + i);
				ready_fd_index = i;
				
				int ridden;
				for (ridden = read (ready_fd,&m,sizeof(m)); ridden <= 0;ridden = read (ready_fd,&m,sizeof(m))){
					if (errno == EINTR){continue;} else {break;}
				}
				
				int written;
				if (ridden > 0){
					fprintf(stdout,"%s from socket id %d\n",m.data,ready_fd);
					for (written = write (ready_fd,&m,sizeof(m)); written <= 0;written = write (ready_fd,&m,sizeof(m))){
						if (errno == EINTR){continue;} else {break;}
					}
					
				}
				
				// test if client has received the packet and exit();
				//the client implementation should only make a read after the server
				// write and exit
				for (ridden = read (ready_fd,&m,sizeof(m)); ridden <= 0;ridden = read (ready_fd,&m,sizeof(m))){
					if (errno == EINTR){continue;} else {break;}
				}
				if (ridden> 0) {fprintf(stdout,"client from socket id %d should be dead\n",ready_fd);}
				
				shutdown (ready_fd, SHUT_RDWR); // SHUT_RD - SHUT_WR
				FD_CLR(ready_fd, &backup_set);
				clients[ready_fd_index] = -1;
				fprintf(stdout,"shutdown socket id %d\n",ready_fd);
				
				
				
				
				
			}
					
		}
		fd_set_1 = backup_set;
		
	}
	exit(0);
}