smtp.c

Vovida 社区开源的 SIP 协议源码

/*
 * Program:	Simple Mail Transfer Protocol (SMTP) routines
 *
 * Author:	Mark Crispin
 *		Networks and Distributed Computing
 *		Computing & Communications
 *		University of Washington
 *		Administration Building, AG-44
 *		Seattle, WA  98195
 *		Internet: [e-mail]
 *
 * Date:	27 July 1988
 * Last Edited:	10 October 2000
 *
 * Sponsorship:	The original version of this work was developed in the
 *		Symbolic Systems Resources Group of the Knowledge Systems
 *		Laboratory at Stanford University in 1987-88, and was funded
 *		by the Biomedical Research Technology Program of the National
 *		Institutes of Health under grant number RR-00785.
 *
 * Original version Copyright 1988 by The Leland Stanford Junior University
 * Copyright 2000 by the University of Washington
 *
 *  Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose and without fee is hereby granted, provided
 * that the above copyright notices appear in all copies and that both the
 * above copyright notices and this permission notice appear in supporting
 * documentation, and that the name of the University of Washington or The
 * Leland Stanford Junior University not be used in advertising or publicity
 * pertaining to distribution of the software without specific, written prior
 * permission.  This software is made available "as is", and
 * THE UNIVERSITY OF WASHINGTON AND THE LELAND STANFORD JUNIOR UNIVERSITY
 * DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, WITH REGARD TO THIS SOFTWARE,
 * INCLUDING WITHOUT LIMITATION ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE, AND IN NO EVENT SHALL THE UNIVERSITY OF
 * WASHINGTON OR THE LELAND STANFORD JUNIOR UNIVERSITY BE LIABLE FOR ANY
 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
 * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
 * CONTRACT, TORT (INCLUDING NEGLIGENCE) OR STRICT LIABILITY, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 */

#include <ctype.h>
#include <stdio.h>
#include "mail.h"
#include "osdep.h"
#include "smtp.h"
#include "rfc822.h"
#include "misc.h"


/* Mailer parameters */

static unsigned long smtp_maxlogintrials = MAXLOGINTRIALS;
static long smtp_port = 0;	/* default port override */
static long smtp_altport = 0;
static char *smtp_altname = NIL;


/* SMTP limits, current as of most recent draft */

#define SMTPMAXLOCALPART 64
#define SMTPMAXDOMAIN 255
#define SMTPMAXPATH 256


/* I have seen local parts of more than 64 octets, in spite of the SMTP
 * limits.  So, we'll have a more generous limit that's still guaranteed
 * not to pop the buffer, and let the server worry about it.  As of this
 * writing, it comes out to 240.  Anyone with a mailbox name larger than
 * that is in serious need of a life or at least a new ISP!  23 June 1998
 */

#define MAXLOCALPART ((MAILTMPLEN - (SMTPMAXDOMAIN + SMTPMAXPATH + 32)) / 2)

/* Mail Transfer Protocol manipulate driver parameters
 * Accepts: function code
 *	    function-dependent value
 * Returns: function-dependent return value
 */

void *smtp_parameters (long function,void *value)
{
  switch ((int) function) {
  case SET_MAXLOGINTRIALS:
    smtp_maxlogintrials = (unsigned long) value;
    break;
  case GET_MAXLOGINTRIALS:
    value = (void *) smtp_maxlogintrials;
    break;
  case SET_SMTPPORT:
    smtp_port = (long) value;
    break;
  case GET_SMTPPORT:
    value = (void *) smtp_port;
    break;
  case SET_ALTSMTPPORT:
    smtp_altport = (long) value;
    break;
  case GET_ALTSMTPPORT:
    value = (void *) smtp_altport;
    break;
  case SET_ALTSMTPNAME:
    smtp_altname = (char *) value;
    break;
  case GET_ALTSMTPNAME:
    value = (void *) smtp_altname;
    break;
  default:
    value = NIL;		/* error case */
    break;
  }
  return value;
}

/* Mail Transfer Protocol open connection
 * Accepts: network driver
 *	    service host list
 *	    port number
 *	    service name
 *	    SMTP open options
 * Returns: SEND stream on success, NIL on failure
 */

SENDSTREAM *smtp_open_full (NETDRIVER *dv,char **hostlist,char *service,
			    unsigned long port,long options)
{
  SENDSTREAM *stream = NIL;
  long reply;
  char *s,tmp[MAILTMPLEN];
  NETSTREAM *netstream;
  NETMBX mb;
  if (!(hostlist && *hostlist)) mm_log ("Missing SMTP service host",ERROR);
				/* maximum domain name is 64 characters */
  else do if (strlen (*hostlist) < SMTPMAXDOMAIN) {
    sprintf (tmp,"{%.1000s/%.20s}",*hostlist,service ? service : "smtp");
    if (!mail_valid_net_parse (tmp,&mb) || mb.anoflag) {
      sprintf (tmp,"Invalid host specifier: %.80s",*hostlist);
      mm_log (tmp,ERROR);
    }
    else {
				/* light tryalt flag if requested */
      mb.tryaltflag = (options & SOP_TRYALT) ? T : NIL;
      if (netstream =		/* try to open ordinary connection */
	  net_open (&mb,dv,smtp_port ? smtp_port : port,
		    (NETDRIVER *) mail_parameters (NIL,GET_ALTDRIVER,NIL),
		    (char *) mail_parameters (NIL,GET_ALTSMTPNAME,NIL),
		    (unsigned long)mail_parameters(NIL,GET_ALTSMTPPORT,NIL))) {
	stream = (SENDSTREAM *) memset (fs_get (sizeof (SENDSTREAM)),0,
					sizeof (SENDSTREAM));
	stream->netstream = netstream;
	stream->debug = (mb.dbgflag || (options & OP_DEBUG)) ? T : NIL;
	if (options & SOP_SECURE) mb.secflag = T;
	if (options &(SOP_DSN | SOP_DSN_NOTIFY_FAILURE | SOP_DSN_NOTIFY_DELAY |
		      SOP_DSN_NOTIFY_SUCCESS | SOP_DSN_RETURN_FULL)) {
	  ESMTP.dsn.want = T;
	  if (options & SOP_DSN_NOTIFY_FAILURE) ESMTP.dsn.notify.failure = T;
	  if (options & SOP_DSN_NOTIFY_DELAY) ESMTP.dsn.notify.delay = T;
	  if (options & SOP_DSN_NOTIFY_SUCCESS) ESMTP.dsn.notify.success = T;
	  if (options & SOP_DSN_RETURN_FULL) ESMTP.dsn.full = T;
	}
	if (options & SOP_8BITMIME) ESMTP.eightbit.want = T;
				/* get name of local host to use */
	s = strcmp ("localhost",lcase (strcpy (tmp,mb.host))) ?
	  net_localhost (netstream) : "localhost";

	do reply = smtp_reply (stream);
	while ((reply < 100) || (stream->reply[3] == '-'));
	if (reply != SMTPGREET){/* get SMTP greeting */
	  sprintf (tmp,"SMTP greeting failure: %.80s",stream->reply);
	  mm_log (tmp,ERROR);
	  stream = smtp_close (stream);
	}
	else if ((reply = smtp_ehlo (stream,s,&mb)) == SMTPOK) {
	  ESMTP.ok = T;
	  if (mb.secflag || mb.user[0]) {
	    if (ESMTP.auth) {	/* have authenticators? */
	      if (!smtp_auth (stream,&mb,tmp)) stream = smtp_close(stream);
	    }
	    else {		/* no available authenticators */
	      sprintf (tmp,"%sSMTP authentication not available: %.80s",
		       mb.secflag ? "Secure " : "",mb.host);
	      mm_log (tmp,ERROR);
	      stream = smtp_close (stream);
	    }
	  }
	}
	else if (mb.secflag || mb.user[0]) {
	  sprintf (tmp,"ESMTP failure: %.80s",stream->reply);
	  mm_log (tmp,ERROR);
	  stream = smtp_close (stream);
	}
				/* try ordinary SMTP then */
	else if ((reply = smtp_send_work (stream,"HELO",s)) != SMTPOK) {
	  sprintf (tmp,"SMTP hello failure: %.80s",stream->reply);
	  mm_log (tmp,ERROR);
	  stream = smtp_close (stream);
	}
      }
    }
  } while (!stream && *++hostlist);
  return stream;
}

/* SMTP authenticate
 * Accepts: stream to login
 *	    parsed network mailbox structure
 *	    scratch buffer
 *	    place to return user name
 * Returns: T on success, NIL on failure
 */

long smtp_auth (SENDSTREAM *stream,NETMBX *mb,char *tmp)
{
  unsigned long trial,auths;
  char *lsterr = NIL;
  char usr[MAILTMPLEN];
  AUTHENTICATOR *at;
  for (auths = ESMTP.auth; stream->netstream && auths &&
       (at = mail_lookup_auth (find_rightmost_bit (&auths) + 1)); ) {
    if (lsterr) {		/* previous authenticator failed? */
      sprintf (tmp,"Retrying using %s authentication after %s",
	       at->name,lsterr);
      mm_log (tmp,NIL);
      fs_give ((void **) &lsterr);
    }
    trial = 0;			/* initial trial count */
    tmp[0] = '\0';		/* empty buffer */
    if (stream->netstream) do {
      if (tmp[0]) mm_log (tmp,WARN);
      if (smtp_send_work (stream,"AUTH",at->name) &&
	  (*at->client) (smtp_challenge,smtp_response,mb,stream,&trial,usr)) {
	if (stream->replycode == SMTPAUTHED) return LONGT;
	if (!trial) {		/* if main program requested cancellation */
	  mm_log ("SMTP Authentication cancelled",ERROR);
	  return NIL;
	}
      }
      lsterr = cpystr (stream->reply);
      sprintf (tmp,"Retrying %s authentication after %s",at->name,lsterr);
    } while (stream->netstream && trial && (trial < smtp_maxlogintrials));
  }
  if (lsterr) {			/* previous authenticator failed? */
    sprintf (tmp,"Can not authenticate to SMTP server: %s",lsterr);
    mm_log (tmp,ERROR);
    fs_give ((void **) &lsterr);
  }
  return NIL;			/* authentication failed */
}

/* Get challenge to authenticator in binary
 * Accepts: stream
 *	    pointer to returned size
 * Returns: challenge or NIL if not challenge
 */

void *smtp_challenge (void *s,unsigned long *len)
{
  SENDSTREAM *stream = (SENDSTREAM *) s;
  return (stream->replycode == SMTPAUTHREADY) ?
    rfc822_base64 ((unsigned char *) stream->reply+4,
		   strlen (stream->reply+4),len) : NIL;
}


/* Send authenticator response in BASE64
 * Accepts: MAIL stream
 *	    string to send
 *	    length of string
 * Returns: T, always
 */

long smtp_response (void *s,char *response,unsigned long size)
{
  SENDSTREAM *stream = (SENDSTREAM *) s;
  unsigned long i,j;
  char *t,*u;
  if (response) {		/* make CRLFless BASE64 string */
    if (size) {
      for (t = (char *) rfc822_binary ((void *) response,size,&i),u = t,j = 0;
	   j < i; j++) if (t[j] > ' ') *u++ = t[j];
      *u = '\0';		/* tie off string */
      i = smtp_send_work (stream,t,NIL);
      fs_give ((void **) &t);
    }
    else i = smtp_send_work (stream,"",NIL);
  }
				/* abort requested */
  else i = smtp_send_work (stream,"*",NIL);
  return LONGT;
}

/* Mail Transfer Protocol close connection
 * Accepts: SEND stream
 * Returns: NIL always
 */

SENDSTREAM *smtp_close (SENDSTREAM *stream)
{
  if (stream) {			/* send "QUIT" */
    smtp_send_work (stream,"QUIT",NIL);
				/* close TCP connection */
    net_close (stream->netstream);
    if (stream->reply) fs_give ((void **) &stream->reply);
    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