Init: code cleanup + comments

client.c

@@ -0,0 +1,117 @@
+#include "client.h"
+
+
+
+int main(int argc, char* argv[]){
+
+	/* [1] Initialisation
+	=========================================================*/
+	/* (1) Socket information */
+	// Server information
+	struct hostent *server_host;
+	// Server socket address
+	static struct sockaddr_in server_addr;
+	// Server socket address length
+	socklen_t sock_len;
+	// Local socket
+	int sock;
+	
+	/* (2) Misc. information */
+	// Response
+	char *msg = "some message";
+	// Reception buffer
+	char buffer[BUFSIZE];
+	// Will contain the response
+	char *response;
+	// Will contain the length of received/sent data
+	int nb_bytes;
+	
+
+
+	/* [2] UPD socket creation
+	=========================================================*/
+	/* (1) Socket initialization */
+	sock = socket(AF_INET, SOCK_DGRAM, 0);
+
+	/* (1-) Manage error */
+	if( sock == -1 ){
+		perror("erreur création socket");
+		exit(1);
+	}
+
+	/* (2) Get host information */
+	server_host = gethostbyname("localhost");
+
+	/* (2-) Manage error */
+	if( server_host == NULL ){
+		perror("erreur adresse serveur");
+		exit(1);
+	}
+
+	/* (3) Create destination socket */
+	bzero(&server_addr, sizeof(struct sockaddr_in)); // clean @server_addr struct before updating
+
+	server_addr.sin_family = AF_INET;     // set server addr family (ipv4)
+	server_addr.sin_port   = htons(4000); // set server port
+
+	memcpy(    &server_addr.sin_addr.s_addr, // ) set host ipv4 addr
+	   /* ( */ server_host->h_addr,          // )
+	   /* ( */ server_host->h_length            );
+
+
+
+
+	/* [3] Send message
+	=========================================================*/
+	// calculate server id struct size	
+	sock_len = sizeof(struct sockaddr_in);
+
+	/* (1) Send message to server (identified by <sockaddr_in>) */
+	nb_bytes = sendto(    sock,                            // ) socket
+		      /* ( */ msg,                             // ) buffer
+		      /* ( */ strlen(msg) + 1,                 // ) buffer size
+		      /* ( */ 0,                               // ) flags
+		      /* ( */ (struct sockaddr*) &server_addr, // ) server identifier
+		      /* ( */ sock_len                            ); // identifier size
+
+
+	/* (2) Check if send succesfully */
+	if( nb_bytes == -1 ){
+		perror("erreur envoi message");
+		exit(1);
+	}
+
+	// log
+	printf("paquet envoyé, nb_bytes = %d\n",nb_bytes);
+
+
+
+	/* [4] Wait for response
+	=========================================================*/
+	nb_bytes = recvfrom(    sock,                            // ) socket
+			/* ( */ buffer,                          // ) receive buffer
+			/* ( */ BUFSIZE,                         // ) buffer size
+			/* ( */ 0,                               // ) flags
+			/* ( */ (struct sockaddr*) &server_addr, // ) server identifier
+			/* ( */ &sock_len                           ); // identifier size
+
+	/* (2) Check if received successfully (and consistently) */
+	if( nb_bytes == -1 ){
+		perror("erreur réponse serveur");
+		exit(1);
+	}
+
+	/* (3) Copy response into var */
+	response = (char *) malloc(nb_bytes * sizeof(char));
+	memcpy(response, buffer, nb_bytes);
+
+	/* (4) log */
+	printf("response recue du serveur : %s\n",response);
+
+
+	/* [5] Close socket
+	=========================================================*/
+	close(sock);
+
+	return 0;
+}

client.h

@@ -0,0 +1,18 @@
+#ifndef _CLIENT_H_
+
+	#define _CLIENT_H_
+
+	#include <stdio.h>
+	#include <stdlib.h>
+	#include <string.h>
+	#include <unistd.h>
+	#include <sys/types.h>
+	#include <netdb.h>
+	#include <sys/socket.h>
+	#include <netinet/in.h>
+	#include <errno.h>
+	
+	#define BUFSIZE 20
+
+
+#endif

makefile

@@ -0,0 +1,26 @@
+CC=-Wall -Werror
+
+
+client.o: client.h client.c
+	gcc $(CC) -c -o client.o client.c
+
+server.o: server.h server.c
+	gcc $(CC) -c -o server.o server.c
+
+lib.o: lib.h lib.c
+	gcc $(CC) -c -o lib.o lib.c
+
+server: lib.o server.o
+	gcc $(CC) -o server lib.o server.o
+
+client: lib.o client.o
+	gcc $(CC) -o client lib.o client.o
+
+
+
+
+all: client server
+
+clean: 
+	rm -rf ./*.o
+	rm client server

server.c

@@ -0,0 +1,120 @@
+#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;
+	// Socket size
+	socklen_t sock_len;
+	// 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);
+	}
+
+	/* (2) Fetch client information */
+	// récupère nom de la machine émettrice des données
+	host_client = gethostbyaddr( &(addr_client.sin_addr), // ) client addr (filled)
+			         /* ( */ sizeof(long),        // ) 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, host_client->h_name, 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);
+}

server.h

@@ -0,0 +1,19 @@
+#ifndef _SERVER_H_
+
+	#define _SERVER_H_
+
+
+
+	#include <stdio.h>
+	#include <stdlib.h>
+	#include <string.h>
+	#include <unistd.h>
+	#include <sys/types.h>
+	#include <netdb.h>
+	#include <sys/socket.h>
+	#include <netinet/in.h>
+	#include <errno.h>
+	
+
+
+#endif