smtp.c

广泛使用的邮件服务器！同时

      smtp_send (stream,"QUIT",NIL);
      if (stream->netstream)	/* could have been closed during "QUIT" */
        net_close (stream->netstream);
    }
				/* clean up */
    if (stream->host) fs_give ((void **) &stream->host);
    if (stream->reply) fs_give ((void **) &stream->reply);
    if (ESMTP.dsn.envid) fs_give ((void **) &ESMTP.dsn.envid);
    if (ESMTP.atrn.domains) fs_give ((void **) &ESMTP.atrn.domains);
    fs_give ((void **) &stream);/* flush the stream */
  }
  return NIL;
}

/* Mail Transfer Protocol deliver mail
 * Accepts: SEND stream
 *	    delivery option (MAIL, SEND, SAML, SOML)
 *	    message envelope
 *	    message body
 * Returns: T on success, NIL on failure
 */

long smtp_mail (SENDSTREAM *stream,char *type,ENVELOPE *env,BODY *body)
{
  RFC822BUFFER buf;
  char tmp[SENDBUFLEN+1];
  long error = NIL;
  long retry = NIL;
  buf.f = smtp_soutr;		/* initialize buffer */
  buf.s = stream->netstream;
  buf.end = (buf.beg = buf.cur = tmp) + SENDBUFLEN;
  tmp[SENDBUFLEN] = '\0';	/* must have additional null guard byte */
  if (!(env->to || env->cc || env->bcc)) {
  				/* no recipients in request */
    smtp_seterror (stream,SMTPHARDERROR,"No recipients specified");
    return NIL;
  }
  do {				/* make sure stream is in good shape */
    smtp_send (stream,"RSET",NIL);
    if (retry) {		/* need to retry with authentication? */
      NETMBX mb;
				/* yes, build remote name for authentication */
      sprintf (tmp,"{%.200s/smtp%s}<none>",
	       (long) mail_parameters (NIL,GET_TRUSTDNS,NIL) ?
	       ((long) mail_parameters (NIL,GET_SASLUSESPTRNAME,NIL) ?
		net_remotehost (stream->netstream) :
		net_host (stream->netstream)) :
	       stream->host,
	       (stream->netstream->dtb ==
		(NETDRIVER *) mail_parameters (NIL,GET_SSLDRIVER,NIL)) ?
	       "/ssl" : "");
      mail_valid_net_parse (tmp,&mb);
      if (!smtp_auth (stream,&mb,tmp)) return NIL;
      retry = NIL;		/* no retry at this point */
    }

    strcpy (tmp,"FROM:<");	/* compose "MAIL FROM:<return-path>" */
#ifdef RFC2821
    if (env->return_path && env->return_path->host &&
	!((strlen (env->return_path->mailbox) > SMTPMAXLOCALPART) ||
	  (strlen (env->return_path->host) > SMTPMAXDOMAIN))) {
      rfc822_cat (tmp,env->return_path->mailbox,NIL);
      sprintf (tmp + strlen (tmp),"@%s",env->return_path->host);
    }
#else				/* old code with A-D-L support */
    if (env->return_path && env->return_path->host &&
	!((env->return_path->adl &&
	   (strlen (env->return_path->adl) > SMTPMAXPATH)) ||
	  (strlen (env->return_path->mailbox) > SMTPMAXLOCALPART) ||
	  (strlen (env->return_path->host) > SMTPMAXDOMAIN)))
      rfc822_address (tmp,env->return_path);
#endif
    strcat (tmp,">");
    if (ESMTP.ok) {
      if (ESMTP.eightbit.ok && ESMTP.eightbit.want)
	strcat (tmp," BODY=8BITMIME");
      if (ESMTP.dsn.ok && ESMTP.dsn.want) {
	strcat (tmp,ESMTP.dsn.full ? " RET=FULL" : " RET=HDRS");
	if (ESMTP.dsn.envid)
	  sprintf (tmp + strlen (tmp)," ENVID=%.100s",ESMTP.dsn.envid);
      }
    }
				/* send "MAIL FROM" command */
    switch (smtp_send (stream,type,tmp)) {
    case SMTPUNAVAIL:		/* mailbox unavailable? */
    case SMTPWANTAUTH:		/* wants authentication? */
    case SMTPWANTAUTH2:
      if (ESMTP.auth) retry = T;/* yes, retry with authentication */
    case SMTPOK:		/* looks good */
      break;
    default:			/* other failure */
      return NIL;
    }
				/* negotiate the recipients */
    if (!retry && env->to) retry = smtp_rcpt (stream,env->to,&error);
    if (!retry && env->cc) retry = smtp_rcpt (stream,env->cc,&error);
    if (!retry && env->bcc) retry = smtp_rcpt (stream,env->bcc,&error);
    if (!retry && error) {	/* any recipients failed? */
      smtp_send (stream,"RSET",NIL);
      smtp_seterror (stream,SMTPHARDERROR,"One or more recipients failed");
      return NIL;
    }
  } while (retry);
				/* negotiate data command */
  if (!(smtp_send (stream,"DATA",NIL) == SMTPREADY)) return NIL;
				/* send message data */
  if (!rfc822_output_full (&buf,env,body,
			   ESMTP.eightbit.ok && ESMTP.eightbit.want)) {
    smtp_fake (stream,"SMTP connection broken (message data)");
    return NIL;			/* can't do much else here */
  }
				/* send trailing dot */
  return (smtp_send (stream,".",NIL) == SMTPOK) ? LONGT : NIL;
}

/* Simple Mail Transfer Protocol send VERBose
 * Accepts: SMTP stream
 * Returns: T if successful, else NIL
 *
 * Descriptive text formerly in [al]pine sources:
 * At worst, this command may cause the SMTP connection to get nuked.  Modern
 * sendmail's recognize it, and possibly other SMTP implementations (the "ON"
 * arg is for PMDF).  What's more, if it works, the reply code and accompanying
 * text may vary from server to server.
 */

long smtp_verbose (SENDSTREAM *stream)
{
				/* accept any 2xx reply code */
  return ((smtp_send (stream,"VERB","ON") / (long) 100) == 2) ? LONGT : NIL;
}

/* Internal routines */


/* Simple Mail Transfer Protocol send recipient
 * Accepts: SMTP stream
 *	    address list
 *	    pointer to error flag
 * Returns: T if should retry, else NIL
 */

long smtp_rcpt (SENDSTREAM *stream,ADDRESS *adr,long *error)
{
 char *s,tmp[2*MAILTMPLEN],orcpt[MAILTMPLEN];
  while (adr) {			/* for each address on the list */
				/* clear any former error */
    if (adr->error) fs_give ((void **) &adr->error);
    if (adr->host) {		/* ignore group syntax */
				/* enforce SMTP limits to protect the buffer */
      if (strlen (adr->mailbox) > MAXLOCALPART) {
	adr->error = cpystr ("501 Recipient name too long");
	*error = T;
      }
      else if ((strlen (adr->host) > SMTPMAXDOMAIN)) {
	adr->error = cpystr ("501 Recipient domain too long");
	*error = T;
      }
#ifndef RFC2821			/* old code with A-D-L support */
      else if (adr->adl && (strlen (adr->adl) > SMTPMAXPATH)) {
	adr->error = cpystr ("501 Path too long");
	*error = T;
      }
#endif

      else {
	strcpy (tmp,"TO:<");	/* compose "RCPT TO:<return-path>" */
#ifdef RFC2821
	rfc822_cat (tmp,adr->mailbox,NIL);
	sprintf (tmp + strlen (tmp),"@%s>",adr->host);
#else				/* old code with A-D-L support */
	rfc822_address (tmp,adr);
	strcat (tmp,">");
#endif
				/* want notifications */
	if (ESMTP.ok && ESMTP.dsn.ok && ESMTP.dsn.want) {
				/* yes, start with prefix */
	  strcat (tmp," NOTIFY=");
	  s = tmp + strlen (tmp);
	  if (ESMTP.dsn.notify.failure) strcat (s,"FAILURE,");
	  if (ESMTP.dsn.notify.delay) strcat (s,"DELAY,");
	  if (ESMTP.dsn.notify.success) strcat (s,"SUCCESS,");
				/* tie off last comma */
	  if (*s) s[strlen (s) - 1] = '\0';
	  else strcat (tmp,"NEVER");
	  if (adr->orcpt.addr) {
	    sprintf (orcpt,"%.498s;%.498s",
		     adr->orcpt.type ? adr->orcpt.type : "rfc822",
		     adr->orcpt.addr);
	    sprintf (tmp + strlen (tmp)," ORCPT=%.500s",orcpt);
	  }
	}
	switch (smtp_send (stream,"RCPT",tmp)) {
	case SMTPOK:		/* looks good */
	  break;
	case SMTPUNAVAIL:	/* mailbox unavailable? */
	case SMTPWANTAUTH:	/* wants authentication? */
	case SMTPWANTAUTH2:
	  if (ESMTP.auth) return T;
	default:		/* other failure */
	  *error = T;		/* note that an error occurred */
	  adr->error = cpystr (stream->reply);
	}
      }
    }
    adr = adr->next;		/* do any subsequent recipients */
  }
  return NIL;			/* no retry called for */
}

/* Simple Mail Transfer Protocol send command
 * Accepts: SEND stream
 *	    text
 * Returns: reply code
 */

long smtp_send (SENDSTREAM *stream,char *command,char *args)
{
  long ret;
  char *s = (char *) fs_get (strlen (command) + (args ? strlen (args) + 1 : 0)
			     + 3);
				/* build the complete command */
  if (args) sprintf (s,"%s %s",command,args);
  else strcpy (s,command);
  if (stream->debug) mail_dlog (s,stream->sensitive);
  strcat (s,"\015\012");
				/* send the command */
  if (stream->netstream && net_soutr (stream->netstream,s)) {
    do stream->replycode = smtp_reply (stream);
    while ((stream->replycode < 100) || (stream->reply[3] == '-'));
    ret = stream->replycode;
  }
  else ret = smtp_fake (stream,"SMTP connection broken (command)");
  fs_give ((void **) &s);
  return ret;
}


/* Simple Mail Transfer Protocol get reply
 * Accepts: SMTP stream
 * Returns: reply code
 */

long smtp_reply (SENDSTREAM *stream)
{
  smtpverbose_t pv = (smtpverbose_t) mail_parameters (NIL,GET_SMTPVERBOSE,NIL);
  long reply;
				/* flush old reply */
  if (stream->reply) fs_give ((void **) &stream->reply);
  				/* get reply */
  if (stream->netstream && (stream->reply = net_getline (stream->netstream))) {
    if (stream->debug) mm_dlog (stream->reply);
				/* return response code */
    reply = atol (stream->reply);
    if (pv && (reply < 100)) (*pv) (stream->reply);
  }
  else reply = smtp_fake (stream,"SMTP connection broken (reply)");
  return reply;
}

/* Simple Mail Transfer Protocol send EHLO
 * Accepts: SMTP stream
 *	    host name to use in EHLO
 *	    NETMBX structure
 * Returns: reply code
 */

long smtp_ehlo (SENDSTREAM *stream,char *host,NETMBX *mb)
{
  unsigned long i,j;
  long flags = (mb->secflag ? AU_SECURE : NIL) |
    (mb->authuser[0] ? AU_AUTHUSER : NIL);
  char *s,*t,*r,tmp[MAILTMPLEN];
				/* clear ESMTP data */
  memset (&ESMTP,0,sizeof (ESMTP));
  if (mb->loser) return 500;	/* never do EHLO if a loser */
  sprintf (tmp,"EHLO %s",host);	/* build the complete command */
  if (stream->debug) mm_dlog (tmp);
  strcat (tmp,"\015\012");
				/* send the command */
  if (!net_soutr (stream->netstream,tmp))
    return smtp_fake (stream,"SMTP connection broken (EHLO)");
				/* got an OK reply? */
  do if ((i = smtp_reply (stream)) == SMTPOK) {
				/* hack for AUTH= */
    if (stream->reply[4] && stream->reply[5] && stream->reply[6] &&
	stream->reply[7] && (stream->reply[8] == '=')) stream->reply[8] = ' ';
				/* get option code */
    if (!(s = strtok_r (stream->reply+4," ",&r)));
				/* have option, does it have a value */
    else if ((t = strtok_r (NIL," ",&r)) && *t) {
				/* EHLO options which take arguments */
      if (!compare_cstring (s,"SIZE")) {
	if (isdigit (*t)) ESMTP.size.limit = strtoul (t,&t,10);
	ESMTP.size.ok = T;
      }
      else if (!compare_cstring (s,"DELIVERBY")) {
	if (isdigit (*t)) ESMTP.deliverby.minby = strtoul (t,&t,10);
	ESMTP.deliverby.ok = T;
      }
      else if (!compare_cstring (s,"ATRN")) {
	ESMTP.atrn.domains = cpystr (t);
	ESMTP.atrn.ok = T;
      }
      else if (!compare_cstring (s,"AUTH"))
	do if ((j = mail_lookup_auth_name (t,flags)) &&
	       (--j < MAXAUTHENTICATORS)) ESMTP.auth |= (1 << j);
	while ((t = strtok_r (NIL," ",&r)) && *t);
    }
				/* EHLO options which do not take arguments */
    else if (!compare_cstring (s,"SIZE")) ESMTP.size.ok = T;
    else if (!compare_cstring (s,"8BITMIME")) ESMTP.eightbit.ok = T;
    else if (!compare_cstring (s,"DSN")) ESMTP.dsn.ok = T;
    else if (!compare_cstring (s,"ATRN")) ESMTP.atrn.ok = T;
    else if (!compare_cstring (s,"SEND")) ESMTP.service.send = T;
    else if (!compare_cstring (s,"SOML")) ESMTP.service.soml = T;
    else if (!compare_cstring (s,"SAML")) ESMTP.service.saml = T;
    else if (!compare_cstring (s,"EXPN")) ESMTP.service.expn = T;
    else if (!compare_cstring (s,"HELP")) ESMTP.service.help = T;
    else if (!compare_cstring (s,"TURN")) ESMTP.service.turn = T;
    else if (!compare_cstring (s,"ETRN")) ESMTP.service.etrn = T;
    else if (!compare_cstring (s,"STARTTLS")) ESMTP.service.starttls = T;
    else if (!compare_cstring (s,"RELAY")) ESMTP.service.relay = T;
    else if (!compare_cstring (s,"PIPELINING")) ESMTP.service.pipe = T;
    else if (!compare_cstring (s,"ENHANCEDSTATUSCODES"))
      ESMTP.service.ensc = T;
    else if (!compare_cstring (s,"BINARYMIME")) ESMTP.service.bmime = T;
    else if (!compare_cstring (s,"CHUNKING")) ESMTP.service.chunk = T;
  }
  while ((i < 100) || (stream->reply[3] == '-'));
				/* disable LOGIN if PLAIN also advertised */
  if ((j = mail_lookup_auth_name ("PLAIN",NIL)) && (--j < MAXAUTHENTICATORS) &&
      (ESMTP.auth & (1 << j)) &&
      (j = mail_lookup_auth_name ("LOGIN",NIL)) && (--j < MAXAUTHENTICATORS))
    ESMTP.auth &= ~(1 << j);
  return i;			/* return the response code */
}

/* Simple Mail Transfer Protocol set fake error and abort
 * Accepts: SMTP stream
 *	    error text
 * Returns: SMTPSOFTFATAL, always
 */

long smtp_fake (SENDSTREAM *stream,char *text)
{
  if (stream->netstream) {	/* close net connection if still open */
    net_close (stream->netstream);
    stream->netstream = NIL;
  }
				/* set last error */
  return smtp_seterror (stream,SMTPSOFTFATAL,text);
}


/* Simple Mail Transfer Protocol set error
 * Accepts: SMTP stream
 *	    SMTP error code
 *	    error text
 * Returns: error code
 */

static long smtp_seterror (SENDSTREAM *stream,long code,char *text)
{
				/* flush any old reply */
  if (stream->reply ) fs_give ((void **) &stream->reply);
  				/* set up pseudo-reply string */
  stream->reply = (char *) fs_get (20+strlen (text));
  sprintf (stream->reply,"%ld %s",code,text);
  return code;			/* return error code */
}


/* Simple Mail Transfer Protocol filter mail
 * Accepts: stream
 *	    string
 * Returns: T on success, NIL on failure
 */

long smtp_soutr (void *stream,char *s)
{
  char c,*t;
				/* "." on first line */
  if (s[0] == '.') net_sout (stream,".",1);
				/* find lines beginning with a "." */
  while (t = strstr (s,"\015\012.")) {
    c = *(t += 3);		/* remember next character after "." */
    *t = '\0';			/* tie off string */
				/* output prefix */
    if (!net_sout (stream,s,t-s)) return NIL;
    *t = c;			/* restore delimiter */
    s = t - 1;			/* push pointer up to the "." */
  }
				/* output remainder of text */
  return *s ? net_soutr (stream,s) : T;
}