aboutsummaryrefslogblamecommitdiffstats
path: root/camel/providers/smtp/camel-smtp-transport.c
blob: 59ee2457f0472460c6f517a846b8fa39570f47bf (plain) (tree)
1
2
3
4
5
6




                                                                           
                                          




















                                                                      
                      


                       
                      




                   

          
                                   
                                






                                 
 

              
                          

                    







                                                                                                                  
                                                 
                                                                           
                                                                      
                                                              



                                                                                                
                                                                                                    


                                                                              

                                               





                                                                                     
                                                
                                                                 

                                                                   
 

                                                    


                                                                 
                                                 





                                                    







                                                           



                                                     
 
                                         





                                                                           
                                                                      

                                              

                                                
 

                                                                                                               
 





                                                        
                                                                       

                               
                        
                        
                                            
 






                                                  
 



                                                    
                                       
                                                                                   


                                                                 
                                                                                    
                                                                              



                                                                                          





                                   
                                                           

                                                                            
 
                                                              

                                                                                
 
                                                                         

                                     
                                 
                                                                                                   
                                                              





                                                                         
                                              
                                                        
                                                                             
                         
 
                                                                










                                                                                
 
                                                                           
                                                                               
                                                                                                      
                                                                                                               
                                                                           
 
                                         

                                                                                                      
 
                                                                   
                                                            
                
                                                                                                         

         










                                                                       

                                                      



                                                     
                                                      
                                                    
                                                           
                                                           

                                  



                    

                                   
 
                          
                           
 
                                        
                                                                      
 


                                                              
 
                                                                          
 
                                               
                                                          
         
 
                   

 

                                           
 


                                                                        

           









                                                                     


            

                                                            
 


                                                             
 
                    







                                                         










                                                                              









                                                           
                 

                                      
                                                                              
 
                                                                                 

                                                                 

                                                                     

                             
 



                                                   
 

                                                                 

                                                                

                             
        
                                                                


                                                                    

                                     
                                   

         
                                                     


                                                             
                                       
 
                    





                                                       
                                                  
                                 
                         
 


                                                                                                         
 
                                                                 
                                                 


                                               

                                                                                 


                                                                 
                                                 


                                               

                                                                                 


                                                                  
                                                  


                                               

                                                                                 
         



                                                             

                                           
 











                                                                                   

 

















                                                                             
                        


                                                                          
                   




                                                         
                        

                                                                                      
 





                                                                                        
                                                                       










                                                                                      

                                                             


                                    

                                                              


                    




                                                             

                                       
                             
 
                                     
                                                                                                                        

                                             

                                                                                               
                                                                                     
            
                                                                                               
                                                                                     
 

                                                                                     
                                
                                                                 


                                                                

                             
                        


                                     
                                 
                                                                                                   
 
                                                                                    
 
                                                              





                                                                         
                                                                           
                                                            


                                                                                           
                 
                                                                             
                         
 
                    




                                                                            



                                                                            
                                                                 
 
                                                    
 
                                                                                     
                                
                                                                 


                                                                     

                             
                        


                                                  
                                 
                                                                                                   
 
                                                                                    
 
                                                              





                                                                          
                                                                             
                         
 
                    




                                                                               




                                                                            
                                                                  
 
                                                    
 

                                                                                     
                                                                 


                                                                   

                             
                        


                                                  
                                 
                                                                                                   
 
                                                                                    
 
                                                              





                                                                         
                                                                             
                         
  
                    


               
                                                                                   
 

                                                          
                                           
                                    
                

                                                                            
                                       
 
                                                    
 
                                                                                     
                                
                                                                 


                                                                

                             
                        
 
                                                                                           
 
                                                                            
 
                                                      


                                                                                     
                                 
                                                                 


                                                             

                             
        
                                    
                                                                                                                       

                                                                                       
 
                                                                                                                      




                                                                                  
         
        
                                                         
                                                           
                                                       

                                        
 
                                                         
 
                                                                            

                                                                                  

                                                          




                                                  
                                 
                                                                                                   
 
                                                                                    
 
                                                              





                                                                                          
                                                                             
                         
 
                    




                                                             



                                                                     
 
                                                    
 

                                                                                     
                                                                 


                                                                

                             
                        


                                     
                                 
                                                                                                   
 
                                                                                    
 
                                                              





                                                                         
                                                                             
                         
 
                    




                                                             



                                                                     
 
                                                    
 
                                                                                     
                                
                                                                 


                                                                

                             
                        


                                     
                                 
                                                                                                   
 
                                                                                    
 
                                                              





                                                                         
                                                                             
                         
 
                    
 
/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* camel-smtp-transport.c : class for a smtp transport */

/* 
 * Authors:
 *   Jeffrey Stedfast <fejj@helixcode.com>
 *
 * Copyright (C) 2000 Helix Code, Inc. (www.helixcode.com)
 *
 * This program is free software; you can redistribute it and/or 
 * modify it under the terms of the GNU General Public License as 
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */

#include "config.h"

#include <sys/param.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#undef MIN
#undef MAX
#include "camel-mime-filter-crlf.h"
#include "camel-stream-filter.h"
#include "camel-smtp-transport.h"
#include "camel-mime-message.h"
#include "camel-stream-buffer.h"
#include "camel-stream-fs.h"
#include "camel-session.h"
#include "camel-exception.h"
#include "md5-utils.h"

#define d(x) x

/* Specified in RFC 821 */
#define SMTP_PORT 25

/* camel smtp transport class prototypes */
static gboolean _can_send (CamelTransport *transport, CamelMedium *message);
static gboolean _send (CamelTransport *transport, CamelMedium *message, CamelException *ex);
static gboolean _send_to (CamelTransport *transport, CamelMedium *message, GList *recipients, CamelException *ex);

/* support prototypes */
static gboolean smtp_connect (CamelService *service, CamelException *ex);
static gboolean smtp_disconnect (CamelService *service, CamelException *ex);
static GList *esmtp_get_authtypes(gchar *buffer);
static GList *query_auth_types (CamelService *service, CamelException *ex);
static void free_auth_types (CamelService *service, GList *authtypes);
static char *get_name (CamelService *service, gboolean brief);
static gchar *smtp_get_email_addr_from_text (gchar *text);
static gboolean smtp_helo (CamelSmtpTransport *transport, CamelException *ex);
static gboolean smtp_mail (CamelSmtpTransport *transport, gchar *sender, CamelException *ex);
static gboolean smtp_rcpt (CamelSmtpTransport *transport, gchar *recipient, CamelException *ex);
static gboolean smtp_data (CamelSmtpTransport *transport, CamelMedium *message, CamelException *ex);
static gboolean smtp_rset (CamelSmtpTransport *transport, CamelException *ex);
static gboolean smtp_quit (CamelSmtpTransport *transport, CamelException *ex);

/* private data members */
static CamelServiceClass *service_class = NULL;

static void
camel_smtp_transport_class_init (CamelSmtpTransportClass *camel_smtp_transport_class)
{
    CamelTransportClass *camel_transport_class =
        CAMEL_TRANSPORT_CLASS (camel_smtp_transport_class);
    CamelServiceClass *camel_service_class =
        CAMEL_SERVICE_CLASS (camel_smtp_transport_class);
    
    service_class = gtk_type_class (camel_service_get_type ());

    /* virtual method overload */
    camel_service_class->connect = smtp_connect;
    camel_service_class->disconnect = smtp_disconnect;
    camel_service_class->query_auth_types = query_auth_types;
    camel_service_class->free_auth_types = free_auth_types;
    camel_service_class->get_name = get_name;

    camel_transport_class->can_send = _can_send;
    camel_transport_class->send = _send;
    camel_transport_class->send_to = _send_to;
}

static void
camel_smtp_transport_init (gpointer object, gpointer klass)
{
    CamelService *service = CAMEL_SERVICE (object);

    service->url_flags = CAMEL_SERVICE_URL_NEED_HOST;
}

GtkType
camel_smtp_transport_get_type (void)
{
    static GtkType camel_smtp_transport_type = 0;

    if (!camel_smtp_transport_type) {
        GtkTypeInfo camel_smtp_transport_info = 
        {
            "CamelSmtpTransport",
            sizeof (CamelSmtpTransport),
            sizeof (CamelSmtpTransportClass),
            (GtkClassInitFunc) camel_smtp_transport_class_init,
            (GtkObjectInitFunc) camel_smtp_transport_init,
            /* reserved_1 */ NULL,
            /* reserved_2 */ NULL,
            (GtkClassInitFunc) NULL,
        };

        camel_smtp_transport_type = gtk_type_unique (CAMEL_TRANSPORT_TYPE, &camel_smtp_transport_info);
    }

    return camel_smtp_transport_type;
}

static gboolean
smtp_connect (CamelService *service, CamelException *ex)
{
    CamelSmtpTransport *transport = CAMEL_SMTP_TRANSPORT (service);
    struct hostent *h;
    struct sockaddr_in sin;
    gint fd, num, i;
    guint32 addrlen;
    gchar *pass = NULL, *respbuf = NULL;


    if (!service_class->connect (service, ex))
        return FALSE;

    h = camel_service_gethost (service, ex);
    if (!h)
        return FALSE;

    /* set some smtp transport defaults */
    transport->smtp_is_esmtp = FALSE;
    transport->esmtp_supported_authtypes = NULL;

    sin.sin_family = h->h_addrtype;
    sin.sin_port = htons (service->url->port ? service->url->port : SMTP_PORT);
    memcpy (&sin.sin_addr, h->h_addr, sizeof (sin.sin_addr));

    fd = socket (h->h_addrtype, SOCK_STREAM, 0);
    if (fd == -1 || connect (fd, (struct sockaddr *)&sin, sizeof (sin)) == -1) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SERVICE_UNAVAILABLE,
                      "Could not connect to %s (port %d): %s",
                      service->url->host,
                      service->url->port ? service->url->port : SMTP_PORT,
                      strerror (errno));
        if (fd > -1)
            close (fd);
        g_free (pass);
        return FALSE;
    }

    /* get the localaddr - needed later by smtp_helo */
    addrlen = sizeof (transport->localaddr);
    getsockname (fd, (struct sockaddr*)&transport->localaddr, &addrlen);

    transport->ostream = camel_stream_fs_new_with_fd (fd);
    transport->istream = camel_stream_buffer_new (transport->ostream, 
                              CAMEL_STREAM_BUFFER_READ);

    /* Read the greeting, note whether the server is ESMTP or not. */
    do {
        /* Check for "220" */
        g_free (respbuf);
        respbuf = camel_stream_buffer_read_line (CAMEL_STREAM_BUFFER (transport->istream));
        if (!respbuf || strncmp (respbuf, "220", 3)) {
            camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                          "Welcome response error: "
                          "%s: possibly non-fatal",
                          g_strerror (errno));
            return FALSE;
        }
        if (strstr (respbuf, "ESMTP"))
            transport->smtp_is_esmtp = TRUE;
    } while (*(respbuf+3) == '-'); /* if we got "220-" then loop again */
    g_free (respbuf);

    /* send HELO (or EHLO, depending on the service type) */
    if (!transport->smtp_is_esmtp) {
        /* If we did not auto-detect ESMTP, we should still send EHLO */
        transport->smtp_is_esmtp = TRUE;
        if (!smtp_helo (transport, ex)) {
            /* Okay, apprently this server doesn't support ESMTP */
            transport->smtp_is_esmtp = FALSE;
            smtp_helo (transport, ex);
        }
    } else {
        smtp_helo (transport, ex);
    }

    /* check to see if AUTH is required, if so...then AUTH ourselves */
    if (transport->smtp_is_esmtp && transport->esmtp_supported_authtypes) {
        /* not really supported yet, but we can at least show what auth types are supported */
        d(fprintf (stderr, "camel-smtp-transport::connect(): %s requires AUTH\n", service->url->host));
        num = g_list_length (transport->esmtp_supported_authtypes);

        for (i = 0; i < num; i++)
            d(fprintf (stderr, "\nSupported AUTH: %s\n\n", 
                (gchar *) g_list_nth_data (transport->esmtp_supported_authtypes, i)));

        g_list_free (transport->esmtp_supported_authtypes);
        transport->esmtp_supported_authtypes = NULL;
    } else {
        d(fprintf (stderr, "\ncamel-smtp-transport::connect(): provider does not use AUTH\n\n"));
    }

    return TRUE;
}

static gboolean
smtp_disconnect (CamelService *service, CamelException *ex)
{
    CamelSmtpTransport *transport = CAMEL_SMTP_TRANSPORT (service);

    if (!service->connected)
        return TRUE;

    /* send the QUIT command to the SMTP server */
    smtp_quit(transport, ex);

    if (!service_class->disconnect (service, ex))
        return FALSE;

    g_free (transport->esmtp_supported_authtypes);
    transport->esmtp_supported_authtypes = NULL;
    gtk_object_unref (GTK_OBJECT (transport->ostream));
    gtk_object_unref (GTK_OBJECT (transport->istream));
    transport->ostream = NULL;
    transport->istream = NULL;

    return TRUE;
}

static GList *
esmtp_get_authtypes (gchar *buffer)
{
    GList *ret = NULL;
    gchar *start, *end;

    /* advance to the first token */
    for (start = buffer; *start == ' ' || *start == '='; start++);

    for ( ; *start; ) {
        /* advance to the end of the token */
        for (end = start; *end && *end != ' '; end++);

        ret = g_list_append (ret, g_strndup (start, end - start));

        /* advance to the next token */
        for (start = end; *start == ' '; start++);
    }

    return ret;
}

static CamelServiceAuthType no_authtype = {
    "No authentication required",

    "This option will connect to the SMTP server without using any "
    "kind of authentication. This should be fine for connecting to "
    "most SMTP servers."

    "",
    FALSE
};

static CamelServiceAuthType cram_md5_authtype = {
    "CRAM-MD5",

    "This option will connect to the SMTP server using CRAM-MD5 "
    "authentication.",

    "CRAM-MD5",
    TRUE
};

static GList *
query_auth_types (CamelService *service, CamelException *ex)
{
    /* FIXME: Re-enable this when auth types are actually
     * implemented.
     */

    return NULL;
}

static void
free_auth_types (CamelService *service, GList *authtypes)
{
    g_list_free (authtypes);
}

static char *
get_name (CamelService *service, gboolean brief)
{
    if (brief)
        return g_strdup_printf ("SMTP server %s", service->url->host);
    else {
        return g_strdup_printf ("SMTP mail delivery via %s",
                    service->url->host);
    }
}

static gboolean
_can_send (CamelTransport *transport, CamelMedium *message)
{
    return CAMEL_IS_MIME_MESSAGE (message);
}

static gboolean
_send_to (CamelTransport *transport, CamelMedium *message,
      GList *recipients, CamelException *ex)
{
    GList *r;
    gchar *recipient, *s, *sender;
    guint i, len;
    CamelSmtpTransport *smtp_transport = CAMEL_SMTP_TRANSPORT (transport);

    s = g_strdup(camel_mime_message_get_from (CAMEL_MIME_MESSAGE (message)));
    if (!s) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      "Cannot send message: "
                      "sender address not defined.");
        return FALSE;
    }

    sender = smtp_get_email_addr_from_text (s);
    smtp_mail (smtp_transport, sender, ex);
    g_free (sender);
    g_free (s);

    if (!(len = g_list_length(recipients))) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      "Cannot send message: "
                      "no recipients defined.");
        return FALSE;
    }
    
    for (i = 0, r = recipients; i < len; i++, r = r->next) {
        recipient = smtp_get_email_addr_from_text (r->data);
        if (!smtp_rcpt (smtp_transport, recipient, ex)) {
            g_free (recipient);
            return FALSE;
        }
        g_free (recipient);
    }

    if (!smtp_data (smtp_transport, message, ex))
        return FALSE;

    /* reset the service for our next transfer session */
    smtp_rset (smtp_transport, ex);

    return TRUE;
}

static gboolean
_send (CamelTransport *transport, CamelMedium *message,
       CamelException *ex)
{
    const CamelInternetAddress *to, *cc, *bcc;
    GList *recipients = NULL;
    guint index, len;

    to = camel_mime_message_get_recipients (CAMEL_MIME_MESSAGE (message), CAMEL_RECIPIENT_TYPE_TO);
    cc = camel_mime_message_get_recipients (CAMEL_MIME_MESSAGE (message), CAMEL_RECIPIENT_TYPE_CC);
    bcc = camel_mime_message_get_recipients (CAMEL_MIME_MESSAGE (message), CAMEL_RECIPIENT_TYPE_BCC);

    /* get all of the To addresses into our recipient list */
    len = CAMEL_ADDRESS (to)->addresses->len;
    for (index = 0; index < len; index++) {
        const char *addr;

        if (camel_internet_address_get (to, index, NULL, &addr))
            recipients = g_list_append (recipients, g_strdup (addr));
    }

    /* get all of the Cc addresses into our recipient list */
    len = CAMEL_ADDRESS (cc)->addresses->len;
    for (index = 0; index < len; index++) {
        const char *addr;

        if (camel_internet_address_get (cc, index, NULL, &addr))
            recipients = g_list_append (recipients, g_strdup (addr));
    }

    /* get all of the Bcc addresses into our recipient list */
    len = CAMEL_ADDRESS (bcc)->addresses->len;
    for (index = 0; index < len; index++) {
        const char *addr;

        if (camel_internet_address_get (bcc, index, NULL, &addr))
            recipients = g_list_append (recipients, g_strdup (addr));
    }

    return _send_to (transport, message, recipients, ex);
}

static gchar *
smtp_get_email_addr_from_text (gchar *text)
{
    /* get the actual email address from the string passed and place it in addr
     * we can assume the address will be in one of the following forms:
     * 1) The Name <person@host.com>
     * 2) <person@host.com>
     * 3) person@host.com
     * 4) person@host.com (The Name)
     */

    gchar *tmp, *addr = NULL;
    gchar *addr_strt;         /* points to start of addr */
    gchar *addr_end;          /* points to end of addr */
    gchar *ptr1;


    /* check the incoming args */
    if (!text || !*text)
        return NULL;

    /* scan the string for an open brace */
    for (addr_strt = text; *addr_strt; addr_strt++) 
        if (*addr_strt == '<')
            break;

    if (*addr_strt) {
        /* we found an open brace, let's look for it's counterpart */
        for (addr_end = addr_strt; *addr_end; addr_end++)
            if (*addr_end == '>') 
                break;

        /* if we didn't find it, or braces are empty... */
        if (!(*addr_end) || (addr_strt == addr_end - 1))
            return NULL;
            
        /* addr_strt points to '<' and addr_end points to '>'.
         * Now let's adjust 'em slightly to point to the beginning
         * and ending of the email addy
         */
        addr_strt++;
        addr_end--;
    } else {
        /* no open brace...assume type 3 or 4? */
        addr_strt = text;
            
        /* find the end of the email addr/string */
        for (addr_end = addr_strt; *addr_end || *addr_end == ' '; addr_end++);
 
        addr_end--;       /* points to NULL, move it back one char */
    }

    /* now addr_strt & addr_end point to the beginning & ending of the email addy */

    /* copy the string into addr */
    addr = g_strndup (addr_strt, (gint)(addr_end - addr_strt + 1));

    for (ptr1 = addr_strt; ptr1 <= addr_end; ptr1++)    /* look for an '@' sign */
        if (*ptr1 == '@')
            break;

    if (*ptr1 != '@') {
        /* here we found out the name doesn't have an '@' part
         * let's figure out what machine we're on & stick it on the end
         */
        gchar hostname[MAXHOSTNAMELEN];

        if (gethostname (hostname, MAXHOSTNAMELEN)) {
            g_free (addr);
            return NULL;
        }
        tmp = addr;
        addr = g_strconcat (tmp, "@", hostname, NULL);
        g_free (tmp);
    }

    return addr;
}

static gboolean
smtp_helo (CamelSmtpTransport *transport, CamelException *ex)
{
    /* say hello to the server */
    gchar *cmdbuf, *respbuf = NULL;
    struct hostent *host;

    /* get the local host name */
    host = gethostbyaddr ((gchar *)&transport->localaddr.sin_addr, sizeof (transport->localaddr.sin_addr), AF_INET);

    /* hiya server! how are you today? */
    if (transport->smtp_is_esmtp)
        cmdbuf = g_strdup_printf ("EHLO %s\r\n", host && host->h_name ? host->h_name : 
                      inet_ntoa (transport->localaddr.sin_addr));
    else
        cmdbuf = g_strdup_printf ("HELO %s\r\n", host && host->h_name ? host->h_name : 
                      inet_ntoa (transport->localaddr.sin_addr));

    d(fprintf (stderr, "sending : %s", cmdbuf));
    if (camel_stream_write (transport->ostream, cmdbuf, strlen (cmdbuf)) == -1) {
        g_free (cmdbuf);
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      "HELO request timed out: "
                      "%s: non-fatal",
                      g_strerror (errno));
        return FALSE;
    }
    g_free (cmdbuf);

    do {
        /* Check for "250" */
        g_free (respbuf);
        respbuf = camel_stream_buffer_read_line (CAMEL_STREAM_BUFFER (transport->istream));

        d(fprintf (stderr, "received: %s\n", respbuf ? respbuf : "(null)"));

        if (!respbuf || strncmp (respbuf, "250", 3)) {
            camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                          "HELO response error: "
                          "%s: non-fatal",
                          g_strerror (errno));
            return FALSE;
        }
        if (transport->smtp_is_esmtp && strstr (respbuf, "AUTH")) {
            /* parse for supported AUTH types */
            char *auths = strstr (respbuf, "AUTH") + 4;
            
            transport->esmtp_supported_authtypes = esmtp_get_authtypes (auths);
        }
    } while (*(respbuf+3) == '-'); /* if we got "250-" then loop again */
    g_free (respbuf);

    return TRUE;
}

static gboolean
smtp_mail (CamelSmtpTransport *transport, gchar *sender, CamelException *ex)
{
    /* we gotta tell the smtp server who we are. (our email addy) */
    gchar *cmdbuf, *respbuf = NULL;

    /* enclose address in <>'s since some SMTP daemons *require* that */
    cmdbuf = g_strdup_printf ("MAIL FROM: <%s>\r\n", sender);

    d(fprintf (stderr, "sending : %s", cmdbuf));

    if (camel_stream_write (transport->ostream, cmdbuf, strlen (cmdbuf)) == -1) {
        g_free (cmdbuf);
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      "MAIL FROM request timed out: "
                      "%s: mail not sent",
                      g_strerror (errno));
        return FALSE;
    }
    g_free (cmdbuf);

    do {
        /* Check for "250 Sender OK..." */
        g_free (respbuf);
        respbuf = camel_stream_buffer_read_line (CAMEL_STREAM_BUFFER (transport->istream));

        d(fprintf (stderr, "received: %s\n", respbuf ? respbuf : "(null)"));

        if (!respbuf || strncmp (respbuf, "250", 3)) {
            camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                          "MAIL FROM response error: "
                          "%s: mail not sent",
                          g_strerror (errno));
            return FALSE;
        }
    } while (*(respbuf+3) == '-'); /* if we got "250-" then loop again */
    g_free (respbuf);

    return TRUE;
}

static gboolean
smtp_rcpt (CamelSmtpTransport *transport, gchar *recipient, CamelException *ex)
{
    /* we gotta tell the smtp server who we are going to be sending
     * our email to */
    gchar *cmdbuf, *respbuf = NULL;

    /* enclose address in <>'s since some SMTP daemons *require* that */
    cmdbuf = g_strdup_printf ("RCPT TO: <%s>\r\n", recipient);

    d(fprintf (stderr, "sending : %s", cmdbuf));

    if (camel_stream_write (transport->ostream, cmdbuf, strlen (cmdbuf)) == -1) {
        g_free (cmdbuf);
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      "RCPT TO request timed out: "
                      "%s: mail not sent",
                      g_strerror (errno));
        return FALSE;
    }
    g_free (cmdbuf);

    do {
        /* Check for "250 Sender OK..." */
        g_free (respbuf);
        respbuf = camel_stream_buffer_read_line (CAMEL_STREAM_BUFFER (transport->istream));

        d(fprintf (stderr, "received: %s\n", respbuf ? respbuf : "(null)"));

        if (!respbuf || strncmp (respbuf, "250", 3)) {
            camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                          "RCPT TO response error: "
                          "%s: mail not sent",
                          g_strerror (errno));
            return FALSE;
        }
    } while (*(respbuf+3) == '-'); /* if we got "250-" then loop again */
    g_free (respbuf);
  
    return TRUE;
}

static gboolean
smtp_data (CamelSmtpTransport *transport, CamelMedium *message, CamelException *ex)
{
    /* now we can actually send what's important :p */
    gchar *cmdbuf, *respbuf = NULL;
    CamelStreamFilter *filtered_stream;
    CamelMimeFilter *mimefilter;
    gint id;

    /* enclose address in <>'s since some SMTP daemons *require* that */
    cmdbuf = g_strdup ("DATA\r\n");

    d(fprintf (stderr, "sending : %s", cmdbuf));

    if (camel_stream_write (transport->ostream, cmdbuf, strlen (cmdbuf)) == -1) {
        g_free (cmdbuf);
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      "DATA request timed out: "
                      "%s: mail not sent",
                      g_strerror (errno));
        return FALSE;
    }
    g_free (cmdbuf);

    respbuf = camel_stream_buffer_read_line (CAMEL_STREAM_BUFFER (transport->istream));

    d(fprintf (stderr, "received: %s\n", respbuf ? respbuf : "(null)"));

    if (!respbuf || strncmp (respbuf, "354", 3)) {
        /* we should have gotten instructions on how to use the DATA command:
         * 354 Enter mail, end with "." on a line by itself
         */
        g_free (respbuf);
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      "DATA response error: "
                      "%s: mail not sent",
                      g_strerror (errno));
        return FALSE;
    }
    
    /* setup stream filtering */
    mimefilter = camel_mime_filter_crlf_new (CAMEL_MIME_FILTER_CRLF_ENCODE, CAMEL_MIME_FILTER_CRLF_MODE_CRLF_DOTS);
        filtered_stream = camel_stream_filter_new_with_stream (transport->ostream);
    id = camel_stream_filter_add (filtered_stream, CAMEL_MIME_FILTER (mimefilter));

    if (camel_data_wrapper_write_to_stream (CAMEL_DATA_WRAPPER (message), CAMEL_STREAM (filtered_stream)) == -1) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      "DATA send timed out: message termination: "
                      "%s: mail not sent",
                      g_strerror (errno));
        return FALSE;
    }
        
    camel_stream_filter_remove (filtered_stream, id);
    camel_stream_flush (CAMEL_STREAM(filtered_stream));
    gtk_object_unref (GTK_OBJECT(filtered_stream));

    /* terminate the message body */

    d(fprintf (stderr, "sending : \\r\\n.\\r\\n\n"));

    if (camel_stream_write (transport->ostream, "\r\n.\r\n", 5) == -1) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      "DATA send timed out: message termination: "
                      "%s: mail not sent",
                      g_strerror (errno));
        return FALSE;
    }

    do {
        /* Check for "250 Sender OK..." */
        g_free (respbuf);
        respbuf = camel_stream_buffer_read_line (CAMEL_STREAM_BUFFER (transport->istream));

        d(fprintf (stderr, "received: %s\n", respbuf ? respbuf : "(null)"));

        if (!respbuf || strncmp (respbuf, "250", 3)) {
            camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                          "DATA response error: message termination: "
                          "%s: mail not sent",
                          g_strerror (errno));
            return FALSE;
        }
    } while (*(respbuf+3) == '-'); /* if we got "250-" then loop again */
    g_free (respbuf);

    return TRUE;
}

static gboolean
smtp_rset (CamelSmtpTransport *transport, CamelException *ex)
{
    /* we are going to reset the smtp server (just to be nice) */
    gchar *cmdbuf, *respbuf = NULL;

    cmdbuf = g_strdup ("RSET\r\n");

    d(fprintf (stderr, "sending : %s", cmdbuf));

    if (camel_stream_write (transport->ostream, cmdbuf, strlen (cmdbuf)) == -1) {
        g_free (cmdbuf);
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      "RSET request timed out: "
                      "%s",
                      g_strerror (errno));
        return FALSE;
    }
    g_free (cmdbuf);

    do {
        /* Check for "250" */
        g_free (respbuf);
        respbuf = camel_stream_buffer_read_line (CAMEL_STREAM_BUFFER (transport->istream));

        d(fprintf (stderr, "received: %s\n", respbuf ? respbuf : "(null)"));

        if (!respbuf || strncmp (respbuf, "250", 3)) {
            camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                          "RSET response error: "
                          "%s",
                          g_strerror (errno));
            return FALSE;
        }
    } while (*(respbuf+3) == '-'); /* if we got "250-" then loop again */
    g_free (respbuf);

    return TRUE;
}

static gboolean
smtp_quit (CamelSmtpTransport *transport, CamelException *ex)
{
    /* we are going to reset the smtp server (just to be nice) */
    gchar *cmdbuf, *respbuf = NULL;

    cmdbuf = g_strdup ("QUIT\r\n");

    d(fprintf (stderr, "sending : %s", cmdbuf));

    if (camel_stream_write (transport->ostream, cmdbuf, strlen (cmdbuf)) == -1) {
        g_free (cmdbuf);
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      "QUIT request timed out: "
                      "%s: non-fatal",
                      g_strerror (errno));
        return FALSE;
    }
    g_free (cmdbuf);

    do {
        /* Check for "221" */
        g_free (respbuf);
        respbuf = camel_stream_buffer_read_line (CAMEL_STREAM_BUFFER (transport->istream));

        d(fprintf (stderr, "received: %s\n", respbuf ? respbuf : "(null)"));

        if (!respbuf || strncmp (respbuf, "221", 3)) {
            camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                          "QUIT response error: "
                          "%s: non-fatal",
                          g_strerror (errno));
            return FALSE;
        }
    } while (*(respbuf+3) == '-'); /* if we got "221-" then loop again */
    g_free (respbuf);

    return TRUE;
}