Le protocole SMTP

HELO <domain> <CRLF>

QUIT <CRLF>

220 mwinf2344.orange.fr ESMTP ABO **************************
EHLO skyrunner.home
250-mwinf2344.orange.fr
250-PIPELINING
250-SIZE 10485760
250-AUTH PLAIN LOGIN
250-AUTH=PLAIN LOGIN
250 8BITMIME
QUIT
221 Bye

MAIL FROM:<adresse_source> <CRLF>

RCPT TO:<dest> <CRLF>

DATA <CRLF>

Date: Fry, 29 Dec 06 14:36:00 +0100 GMT
From: "aaa" <aaa@aaa.com>
Subject: Test SMTP
To: "bbb" <bbb@bbb.com>
Cc: "xxx" <xxx@xxx.com>, "yyy" <yyy@yyy.com>
Bcc: "zzz" <zzz@zzz.com>

serveur SMTP
domaine
adresse source
adresse(s) destination(s), séparées par des virgules sans espace
En-tête du message

Message

smtp.wanadoo.fr
skyrunner.home
xxx@wanadoo.fr
yyy@hotmail.com
From: "xxx" <xxx@wanadoo.fr>
To: "yyy" <yyy@hotmail.com>
Subject: Test SMTP

Bonjour,
Test pour le programme C.

#ifndef CLIENT_SMTP_H
#define CLIENT_SMTP_H

#ifdef WIN32

#include <winsock2.h>

#elif defined (linux)

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h> /* close */
#include <netdb.h> /* gethostbyname */
#define INVALID_SOCKET -1
#define SOCKET_ERROR -1
#define closesocket(s) close(s)
typedef int SOCKET;
typedef struct sockaddr_in SOCKADDR_IN;
typedef struct sockaddr SOCKADDR;
typedef struct in_addr IN_ADDR;

#else

#error not defined for this platform

#endif

#define EHLO        "EHLO"
#define MAIL_FROM   "MAIL FROM:"
#define RCPT_TO     "RCPT TO:"
#define DATA        "DATA"
#define END_DATA    "."
#define QUIT        "QUIT"
#define PORT        25
#define BUF_SIZE    1024
#define CRLF        "\r\n"

static void init(void);
static void end(void);
static void app(const char *filename);
static void read_server(SOCKET sock, char *buffer);
static void write_server(SOCKET sock, char *buffer);
static void send_message(FILE *file, SOCKET sock, char *buffer);
static void get_line(FILE *file, char *buffer);
static void get_and_send_rcpts(SOCKET sock, FILE *file);

#endif /* guard */

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>

#include "client_smtp.h"

static void init(void)
{
#ifdef WIN32
    WSADATA wsa;
    int err = WSAStartup(MAKEWORD(2, 2), &wsa);
    if(err < 0)
    {
        puts("WSAStartup failed !");
        exit(EXIT_FAILURE);
    }
#endif
}

static void end(void)
{
#ifdef WIN32
    WSACleanup();
#endif
}

static void app(const char *filename)
{
    SOCKET sock = socket(AF_INET, SOCK_STREAM, 0);
    SOCKADDR_IN sin;
    struct hostent *hostinfo;
    char command[BUF_SIZE];
    char buffer[BUF_SIZE];
    FILE *file = NULL;

    file = fopen(filename, "r");

    if(file == NULL)
    {
        perror("fopen()");
        exit(errno);
    }

    if(sock == INVALID_SOCKET)
    {
        perror("socket()");
        exit(errno);
    }

    get_line(file, buffer);
    hostinfo = gethostbyname(buffer);
    if (hostinfo == NULL)
    {
        fprintf (stderr, "Unknown host %s.\n", buffer);
        exit(EXIT_FAILURE);
    }

    sin.sin_addr = *(IN_ADDR *) hostinfo->h_addr;
    sin.sin_port = htons(PORT);
    sin.sin_family = AF_INET;

    if(connect(sock,(SOCKADDR *) &sin, sizeof(SOCKADDR)) == SOCKET_ERROR)
    {
        perror("connect()");
        exit(errno);
    }

    /* read response */
    read_server(sock, buffer);
    puts(buffer);

    /* send EHLO */
    get_line(file, buffer);
    sprintf(command, "%s %s%s", EHLO, buffer, CRLF);
    write_server(sock, command);

    /* read response */
    read_server(sock, buffer);
    puts(buffer);

    /* send MAIL FROM */
    get_line(file, buffer);
    sprintf(command, "%s<%s>%s", MAIL_FROM, buffer, CRLF);
    write_server(sock, command);

    /* read response */
    read_server(sock, buffer);
    puts(buffer);

    /* send RCTP TO */
    get_and_send_rcpts(sock, file);

    /* read response */
    read_server(sock, buffer);
    puts(buffer);

    /* send DATA */
    sprintf(command, "%s%s", DATA, CRLF);
    write_server(sock, command);

    /* read response */
    read_server(sock, buffer);
    puts(buffer);

    /* send body of the message */
    send_message(file, sock, buffer);
    fclose(file), file = NULL;

    /* send the mark of the end of the message */
    sprintf(command, "%s%s%s", END_DATA, CRLF, CRLF);
    write_server(sock, command);

    /* read response */
    read_server(sock, buffer);
    puts(buffer);

    /* send QUIT */
    sprintf(command, "%s%s", QUIT, CRLF);
    write_server(sock, command);

    /* read response */
    read_server(sock, buffer);
    puts(buffer);

    closesocket(sock);
}

static void read_server(SOCKET sock, char *buffer)
{
    char *p;
    int n = 0;

    if((n = recv(sock, buffer, BUF_SIZE - 1, 0)) < 0)
    {
        perror("recv()");
        exit(errno);
    }
    
    if(n == 0)
    {
       printf("Connection lost\n");
       exit(EXIT_FAILURE);
    }
    
    buffer[n] = 0;

    p = strstr(buffer, CRLF);

    if(p != NULL)
    {
        *p = 0;
    }
}

static void write_server(SOCKET sock, char *buffer)
{
    if(send(sock, buffer, strlen(buffer), 0) < 0)
    {
        perror("send()");
        exit(errno);
    }
}

static void get_line(FILE *file, char *buffer)
{
    if(fgets(buffer, BUF_SIZE, file) != NULL)
    {
        char *p;

        p = strchr(buffer, '\n');

        if(p != NULL)
        {
            *p = 0;
        }
        else
        {
            int c;

            while((c = fgetc(file)) != '\n' && c != EOF)
            {
            }
        }
    }
    else if(!feof(file))
    {
        puts("Error read file !");
    }
}

static void get_and_send_rcpts(SOCKET sock, FILE *file)
{
    char buffer[BUF_SIZE];
    char *rcpt = NULL;

    if(fgets(buffer, BUF_SIZE, file) != NULL)
    {
        char *p;

        p = strchr(buffer, '\n');

        if(p != NULL)
        {
            *p = 0;
        }
        else
        {
            int c;

            while((c = fgetc(file)) != '\n' && c != EOF)
            {
            }
        }
    }
    else if(!feof(file))
    {
        puts("Error read file !");
    }

    rcpt = strtok(buffer, ",");

    while(rcpt != NULL)
    {
        char command[BUF_SIZE];
        sprintf(command, "%s<%s>%s", RCPT_TO, rcpt, CRLF);
        write_server(sock, command);

        rcpt = strtok(NULL, ",");
    }
}

static void send_message(FILE *file, SOCKET sock, char *buffer)
{
    char message[BUF_SIZE];

    while(fgets(buffer, BUF_SIZE, file) != NULL)
    {
        char *p = strchr(buffer, '\n');
        if(p != NULL)
        {
            *p = 0;
            sprintf(message, "%s%s", buffer, CRLF);
            write_server(sock, message);
        }
        else
        {
            int c;

            write_server(sock, buffer);

            while ((c = fgetc(file)) != '\n' && c != EOF)
            {
                char ch = c;
                write_server(sock, &ch);
            }

            write_server(sock, CRLF);
        }
    }

    if(!feof(file))
    {
        puts("Error read file !");
        exit(EXIT_FAILURE);
    }
}

int main(int argc, char **argv)
{
    if(argc < 2)
    {
        printf("Usage : %s [filename]\n", argv[0]);
        return EXIT_FAILURE;
    }

    init();

    app(argv[1]);

    end();

    return EXIT_SUCCESS;
}