Les protocoles de messagerie : SMTP, POP et IMAP

#include <stdio.h>
#include <netdb.h>
#include <unistd.h>
#include <string.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/socket.h>

#define PACKET_SIZE 1024

void appli(char* f);
int writen(int fd, char* ptr, int n);
int readn(int fd, char* ptr, int n);

int to_server_socket=-1;
char server_name[] = "213.228.0.44";	/*smtp.free.fr*/
int port = 25;
char helo[] = "HELO 82.57.221.51\n";
char from[] = "MAIL FROM:<toto@gtre.com>\n";
char to[] = "RCPT TO:<diam@gtre.fr>\n";
char subject[] = "Subject: ";

int main(int argc, char* argv[])
{
	struct sockaddr_in serverSockAddr;	/*adresse de la socket*/
	struct hostent* serverHostEnt;		/*description du host server*/
	unsigned long hostAddr;				/*adresse du server*/
	char* filename;

	if(argc==2) filename = argv[1];
	else filename= NULL;	/*use stdin*/

	bzero((void*)&serverSockAddr, sizeof(serverSockAddr));	/*initialise à zero serverSockAddr*/
	hostAddr = inet_addr(server_name); /* converti l'adresse ip en entier long*/

	if( (long)hostAddr!=(long)-1)
	{
		bcopy((void*)&hostAddr,(void*)&serverSockAddr.sin_addr,sizeof(hostAddr));
	}
	else	/*si on donne un nom*/
	{
		printf("Hey!\n");
		serverHostEnt = gethostbyname(server_name);
		bcopy((void*)serverHostEnt->h_addr,(void*)&serverSockAddr.sin_addr,serverHostEnt->h_length);
	}

	serverSockAddr.sin_port = htons(port);  /* host to network port */
	serverSockAddr.sin_family = AF_INET;	/* AF_*** : INET=internet */
	/*creation de la socket */
	to_server_socket = socket(AF_INET, SOCK_STREAM, 0);
	/* requete de la connexion */
	connect(to_server_socket,(struct sockaddr *)&serverSockAddr, sizeof(serverSockAddr));
	
	/*appel de l'appli*/
	appli(filename);

	/*fermeture de la connexion */
	shutdown(to_server_socket,2);
	close(to_server_socket);
	return 0;
}

void appli(char* filename)
{
	char buf[PACKET_SIZE+1], *ptr;
	FILE* bulk;
	int nb;

	if(filename==NULL) bulk=stdin;
	else bulk=fopen(filename,"rb");
	buf[0] = 0x00;
	readn(to_server_socket, buf, PACKET_SIZE);
	printf(buf);
	writen(to_server_socket, helo, strlen(helo));
	readn(to_server_socket, buf, PACKET_SIZE);
	printf(buf);
	writen(to_server_socket, from, strlen(from));
	readn(to_server_socket, buf, PACKET_SIZE);
	printf(buf);
	writen(to_server_socket, to, strlen(to));
	readn(to_server_socket, buf, PACKET_SIZE);
	printf(buf);
	writen(to_server_socket, "data\n", 5);
	readn(to_server_socket, buf, PACKET_SIZE);
	printf(buf);

	sprintf(buf,"%s %s\r\n\r\n", subject, ((filename==NULL)?"STDIN":filename) );
	writen(to_server_socket, buf, strlen(buf));
	/* ecrit le fichier toto ds la socket */
	while(!feof(bulk))
	{
		bzero((void*)buf,PACKET_SIZE+1);
		nb = fread(buf,sizeof(char), PACKET_SIZE, bulk);
		buf[nb] = 0x00;
		while( (ptr=strstr(buf, "\r\n.\r\n"))!=NULL) *(ptr+3)='.';
		writen(to_server_socket, buf, nb);
	}
	
	writen(to_server_socket, "\r\n.\r\n",5);
	readn(to_server_socket, buf, PACKET_SIZE);
	printf(buf);
	fclose(bulk);
}

int writen(int fd, char* ptr, int n)
{
	int nl, nw;
	nl=n;
	while(nl>0)
	{
		nw=write(fd,ptr,nl);
		if(nw<=0) return nw;	/*erreur*/
		nl-=nw;
		ptr+=nw;
	}
	return (n-nl);
}

int readn(int fd, char* ptr, int n)
{
	int nl, nr;
	nl = n;
	while( nl> 0)
	{
		nr = read(fd, ptr, nl);
		if(nr<0) return nr;	/*erreur*/
		else if(nr==0) break;
		nl-=nr;
		ptr+=nr;
		if( *(ptr-2)=='\r' && *(ptr-1)=='\n')
			break;
	}
	*ptr = 0x00;
	return (n-nl);
}

/*
 * Created on 2 nov. 2004
 *
 */
package smtp;

import java.net.*;
import java.io.*;

/**
 * @author Adrien BOUVET
 * 
 */
public class smtpClient
{
	private String server, message, dest, origin;
	private int port;
	private Socket socket;
	
	public smtpClient(String serv, int por, String org)
	{
		server = serv;
		port = por;
		origin = org;
	}
	
	public void createMsg(String dst, String msg)
	{
		message = msg;
		dest = dst;
	}
	
	public void sendMsg()
	{
		PrintWriter to;
		BufferedReader from;
		String str;
		
		try {
			socket = new Socket(InetAddress.getByName(server),port);
			
			to = new PrintWriter( new BufferedWriter(new OutputStreamWriter (socket.getOutputStream())),true);
			from = new BufferedReader( new InputStreamReader(socket.getInputStream()));
			str = from.readLine();
			to.println("EHLO 82.57.221.51");
			str = from.readLine(); System.err.println(str);
			to.println("MAIL FROM:<"+origin+">");
			str = from.readLine(); System.err.println(str);
			to.println("RCPT TO:<"+dest+">");
			str = from.readLine(); System.err.println(str);
			to.println("DATA");
			str = from.readLine(); System.err.println(str);
			to.println("Subject: héhé\r\n\r\n" + message + "\r\n.\r\n");
			str = from.readLine(); System.err.println(str);
			
			socket.close();			
		}catch( Exception e) {}		
	}
	
	
	public static void main(String[] args)
	{
		smtpClient c = new smtpClient("213.228.0.62", 25, "fake@free.fr");
		c.createMsg("diam@gtre.fr", "yeah!!!!");	// (dest, msg)
		c.sendMsg();
	}
}