sysdis-tp/server.c

#include "server.h"



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

	/* [1] Initialisation
	=========================================================*/
	/* (1) Socket info */
	// Server (local)
	static struct sockaddr_in addr_server;
	// Client
	static struct sockaddr_in addr_client;
	// Client identifier
	struct hostent *host_client = NULL;
	// Socket size
	socklen_t sock_len;
	char client_ip[20];
	// Socket
	int sock;


	/* (2) Misc. information */
	// response
	char *response = "bien recu";
	// reception buffer
	char buffer[BUFSIZE];
	// received buffer
	char *received;
	// length of received/sent data
	int buf_len;



	/* [2] Create socket
	=========================================================*/
	/* (1) Create socket */
	sock = socket(AF_INET, SOCK_DGRAM, 0); // ipv4, udp, flags?

	/* (1-) Manage error */
	if( sock == -1 ){
		perror("erreur création socket");
		exit(1);
	}

	
	/* (2) Set socket information */
	bzero(&addr_server, sizeof(struct sockaddr_in));

	addr_server.sin_family      = AF_INET;           // ipv4
	addr_server.sin_port        = htons(4000);       // port: 4000
	addr_server.sin_addr.s_addr = htonl(INADDR_ANY); // 

	/* (3) Bind socket to local port */
	int bounded = bind(    sock,                           // ) socket
		       /* ( */ (struct sockaddr*)&addr_server, // ) filled with address
		       /* ( */ sizeof(addr_server)                ); // length of struct

	/* (3-) Manage error */
	if( bounded == -1 ){	
		perror("erreur bind");
		exit(1);
	}

	/* [3] Wait for client message
	=========================================================*/
	// set socket length
	sock_len = sizeof(struct sockaddr_in);

	/* (1) Wait for message */
	buf_len = recvfrom(sock,                                // ) socket
		       /* ( */ buffer,                          // ) buffer
		       /* ( */ BUFSIZE,                         // ) buffer length
		       /* ( */ 0,                               // ) flags
		       /* ( */ (struct sockaddr *)&addr_client, // ) client addr (filled)
		       /* ( */ &sock_len                           );

	/* (1-) Manage error */
	if( buf_len == -1 ){
		perror("erreur réception paquet");
		exit(1);
	}

	// Get client ip
	inet_ntop(AF_INET, &(addr_client.sin_addr), client_ip, 20);

	/* (2) Fetch client information */
	// récupère nom de la machine émettrice des données
	host_client = gethostbyaddr(    &addr_client.sin_addr, // ) client addr (filled)
			        /* ( */ sizeof(struct in_addr),       // ) sizeof addr
			        /* ( */ AF_INET                ); // ipv4

	/* (2-) Manage error */
	if( host_client == NULL ){
		perror("erreur gethostbyaddr");
		exit(1);
	} 

	/* (3) Store message */
	received = (char *) malloc(buf_len * sizeof(char));
	memcpy(received, buffer, buf_len);

	printf( "recu message %s de %s:%d\n", received, client_ip, ntohs(addr_client.sin_port) );

	/* [4] Send response
	=========================================================*/
	/* (1) Send response */
	buf_len = sendto(sock,                                // ) socket
		     /* ( */ response,                        // ) response
		     /* ( */ strlen(response)+1,              // ) response length
		     /* ( */ 0,                               // ) flags
		     /* ( */ (struct sockaddr*) &addr_client, // ) client identifier
		     /* ( */ sock_len                            ); // identifier length

	/* (1-) Manage error */
	if( buf_len == -1 ){
		perror("erreur envoi réponse");
		exit(1);
	}

	/* [5] Close socket
	=========================================================*/
	close(sock);
}