unisa_lab_reti_2013_2014/11.client-server-exam-database/daytimesrv.c

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




void sigchldaction (int signal){

	int status, pid;
     
   for (pid = waitpid(-1,&status,WNOHANG);pid > 0;pid = waitpid(-1,&status,WNOHANG)){
   	// server: child terminated
   }  


}



typedef struct message {
	char data [50];
	char nome [50];
	char voto [50];
}t_message;

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


struct sigaction sigchldstructure;
       sigchldstructure.sa_handler = sigchldaction;
       sigchldstructure.sa_flags = 0;
          
sigaction (SIGCHLD, &sigchldstructure, NULL);


	int			listenfd, connfd, n;
	struct sockaddr_in	servaddr;
	char			buff[INET_ADDRSTRLEN]; // client ip grabbed redeable
	short			port; // client port redeable

	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);
		}

	struct sockaddr_in	client_addr;
	unsigned int client_addr_len = sizeof(client_addr);
	
	

	for ( ; ; ) {
		if( (connfd = accept(listenfd, (struct sockaddr *) &client_addr, &client_addr_len)) < 0)
		{ 
			if(errno == EINTR || errno==ECONNABORTED)
				continue;
			printf("accept error\n");
			exit(1);
		} 


	    int split = fork();
			
			if ( split < 0) {
				printf("fork for iterative server failed\n");
				exit(-1);
			}
			
			if (split == 0){
				close(listenfd);

				t_message m; // buffer message structure
				int ridden, wrote;

				sprintf ( m.data, "Benvenuto" );
				wrote = write (connfd, &m, sizeof (m)  ); // scrivo benvenuto sul socket
				// check wrote

		
				
				inet_ntop(AF_INET, &(client_addr.sin_addr), buff, INET_ADDRSTRLEN); // get client address
				port = ntohs(client_addr.sin_port);// get client port
				//fprintf (stdout,"%s%c%hu\n",buff,':',port);  // print client address and port


				for ( ; ; ) {// the server child reserve other requests from same client
					ridden = read (connfd,&m,sizeof(m));
					// check read. it's blocking

					int fd;	

					if (strcmp (m.data, "AGGIUNGI" ) == 0 ){
						   fd = open ("archivio.txt",O_RDWR | O_APPEND);
						   if (fd < 0){
								fd = open ("archivio.txt", O_CREAT | O_RDWR | O_APPEND ,00700);
						   }
							if (fd < 0){
						     	sprintf ( m.data, "Non posso modificare il database" );
								wrote = write (connfd, &m, sizeof (m) ); // scrivo  sul socket
								// check wrote
							} else {

							write (fd,(m.nome), strlen ((m.nome)));
							write (fd," ", 1);
							write (fd,(m.voto), strlen ((m.voto)) );
							write (fd," ", 1);
							write (fd,buff, strlen (buff));
							write (fd,":", 1);

							char port_char[50];
							sprintf (port_char,"%hu",port);
							write (fd,port_char, strlen (port_char));
							write (fd,"\n", 1); 


							sprintf ( m.data, "AGGIUNTO" );
								wrote = write (connfd, &m, sizeof (m) ); // scrivo sul socket
								// check wrote

						    }
					} else {
						if (strcmp (m.data, "VERIFICA" ) == 0 ){

							fd = open ("archivio.txt",O_RDONLY);
							if (fd < 0){
						     	sprintf ( m.data, "Non posso leggere il database" );
								wrote = write (connfd, &m, sizeof (m)  ); // scrivo  sul socket
								// check wrote
							} else {

								char  line [1000];
								char  line_nome [50];
								char  line_voto [50];
								char  line_ip_port [50];
								int returned,found;

								found = 0;
								FILE * fdfile = fdopen(fd,"r");
								returned = fscanf (fdfile,"%999[^\n]%*c",line);
								for( ; returned > 0 ;  fscanf (fdfile,"%999[^\n]%*c",line) ){

									sscanf (line, "%s %s %s", line_nome, line_voto, line_ip_port);

									if (strcmp (line_nome, m.nome) == 0){
										found = 1;

										sprintf ( m.data, "%s ha sostenuto l'esame con voto %s. Informazione fornita da %s ", line_nome, line_voto, line_ip_port );
										wrote = write (connfd, &m, sizeof (m) ); // scrivo sul socket
										// check wrote

										break;
									} 

								}

								if (found == 0){
									sprintf ( m.data, "%s non ha sostenuto l'esame", &(m.nome) );
									wrote = write (connfd, &m, sizeof (m)  ); // scrivo sul socket
									// check wrote
								}
						    }

						} else {

						sprintf ( m.data, "Bye" );
						wrote = write (connfd, &m, sizeof (m) ); // scrivo  sul socket
						// check wrote

						break; // end requests from client

						}
					}

				}


				exit(0); // server child served the client. end
				
			} else {
				
				close(connfd);
			}
		
		
	}
}