mail.c

广泛使用的邮件服务器！同时

 * Returns: stream to use on success, NIL on failure
 */

MAILSTREAM *mail_open (MAILSTREAM *stream,char *name,long options)
{
  int i;
  char c,*s,tmp[MAILTMPLEN];
  NETMBX mb;
  DRIVER *d;
  switch (name[0]) {		/* see if special handling */
  case '#':			/* possible special hacks */
    if (((name[1] == 'M') || (name[1] == 'm')) &&
	((name[2] == 'O') || (name[2] == 'o')) &&
	((name[3] == 'V') || (name[3] == 'v')) &&
	((name[4] == 'E') || (name[4] == 'e')) && (c = name[5]) &&
	(s = strchr (name+6,c)) && (i = s - (name + 6)) && (i < MAILTMPLEN)) {
      if (stream = mail_open (stream,s+1,options)) {
	strncpy (tmp,name+6,i);	/* copy snarf mailbox name */
	tmp[i] = '\0';		/* tie off name */
	mail_parameters (stream,SET_SNARFMAILBOXNAME,(void *) tmp);
	stream->snarf.options = options;
	mail_ping (stream);	/* do initial snarf */
				/* punt if can't do initial snarf */
	if (!stream->snarf.time) stream = mail_close (stream);
      }
      return stream;
    }
				/* special POP hack */
    else if (((name[1] == 'P') || (name[1] == 'p')) &&
	     ((name[2] == 'O') || (name[2] == 'o')) &&
	     ((name[3] == 'P') || (name[3] == 'p')) &&
	     mail_valid_net_parse_work (name+4,&mb,"pop3") &&
	!strcmp (mb.service,"pop3") && !mb.anoflag && !mb.readonlyflag) {
      if (stream = mail_open (stream,mb.mailbox,options)) {
	sprintf (tmp,"{%.255s",mb.host);
	if (mb.port) sprintf (tmp + strlen (tmp),":%lu",mb.port);
	if (mb.user[0]) sprintf (tmp + strlen (tmp),"/user=%.64s",mb.user);
	if (mb.dbgflag) strcat (tmp,"/debug");
	if (mb.secflag) strcat (tmp,"/secure");
	if (mb.tlsflag) strcat (tmp,"/tls");
	if (mb.notlsflag) strcat (tmp,"/notls");
	if (mb.sslflag) strcat (tmp,"/ssl");
	if (mb.trysslflag) strcat (tmp,"/tryssl");
	if (mb.novalidate) strcat (tmp,"/novalidate-cert");
	strcat (tmp,"/pop3/loser}");
	mail_parameters (stream,SET_SNARFMAILBOXNAME,(void *) tmp);
	mail_ping (stream);	/* do initial snarf */
      }
      return stream;		/* return local mailbox stream */
    }

    else if ((options & OP_PROTOTYPE) &&
	     ((name[1] == 'D') || (name[1] == 'd')) &&
	     ((name[2] == 'R') || (name[2] == 'r')) &&
	     ((name[3] == 'I') || (name[3] == 'i')) &&
	     ((name[4] == 'V') || (name[4] == 'v')) &&
	     ((name[5] == 'E') || (name[5] == 'e')) &&
	     ((name[6] == 'R') || (name[6] == 'r')) && (name[7] == '.')) {
      sprintf (tmp,"%.80s",name+8);
				/* tie off name at likely delimiter */
      if (s = strpbrk (tmp,"/\\:")) *s++ = '\0';
      else {
	sprintf (tmp,"Can't resolve mailbox %.80s: bad driver syntax",name);
	MM_LOG (tmp,ERROR);
	return mail_close (stream);
      }
      for (d = maildrivers; d && compare_cstring (d->name,tmp); d = d->next);
      if (d) return (*d->open) (NIL);
      sprintf (tmp,"Can't resolve mailbox %.80s: unknown driver",name);
      MM_LOG (tmp,ERROR);
      return mail_close (stream);
    }
				/* fall through to default case */
  default:			/* not special hack (but could be # name */
    d = mail_valid (NIL,name,(options & OP_SILENT) ?
		    (char *) NIL : "open mailbox");
  }
  return d ? mail_open_work (d,stream,name,options) : stream;
}

/* Mail open worker routine
 * Accepts: factory
 *	    candidate stream for recycling
 *	    mailbox name
 *	    open options
 * Returns: stream to use on success, NIL on failure
 */

MAILSTREAM *mail_open_work (DRIVER *d,MAILSTREAM *stream,char *name,
			    long options)
{
  int i;
  char tmp[MAILTMPLEN];
  NETMBX mb;
  if (options & OP_PROTOTYPE) return (*d->open) (NIL);
  /* name is copied here in case the caller does a re-open using
   * stream->mailbox or stream->original_mailbox as the argument.
   */
  name = cpystr (name);		/* make copy of name */
  if (stream) {			/* recycling requested? */
    if ((stream->dtb == d) && (d->flags & DR_RECYCLE) &&
	((d->flags & DR_HALFOPEN) || !(options & OP_HALFOPEN)) &&
	mail_usable_network_stream (stream,name)) {
				/* yes, checkpoint if needed */
      if (d->flags & DR_XPOINT) mail_check (stream);
      mail_free_cache (stream);	/* clean up stream */
      if (stream->mailbox) fs_give ((void **) &stream->mailbox);
      if (stream->original_mailbox)
	fs_give ((void **) &stream->original_mailbox);
				/* flush user flags */
      for (i = 0; i < NUSERFLAGS; i++)
	if (stream->user_flags[i]) fs_give ((void **) &stream->user_flags[i]);
    }
    else {			/* stream not recycleable, babble if net */
      if (!stream->silent && stream->dtb && !(stream->dtb->flags&DR_LOCAL) &&
	  mail_valid_net_parse (stream->mailbox,&mb)) {
	sprintf (tmp,"Closing connection to %.80s",mb.host);
	MM_LOG (tmp,(long) NIL);
      }
				/* flush the old stream */
      stream = mail_close (stream);
    }
  }
				/* check if driver does not support halfopen */
  else if ((options & OP_HALFOPEN) && !(d->flags & DR_HALFOPEN)) {
    fs_give ((void **) &name);
    return NIL;
  }

				/* instantiate new stream if not recycling */
  if (!stream) (*mailcache) (stream = (MAILSTREAM *)
			     memset (fs_get (sizeof (MAILSTREAM)),0,
				     sizeof (MAILSTREAM)),(long) 0,CH_INIT);
  stream->dtb = d;		/* set dispatch */
				/* set mailbox name */
  stream->mailbox = cpystr (stream->original_mailbox = name);
				/* initialize stream flags */
  stream->inbox = stream->lock = NIL;
  stream->debug = (options & OP_DEBUG) ? T : NIL;
  stream->rdonly = (options & OP_READONLY) ? T : NIL;
  stream->anonymous = (options & OP_ANONYMOUS) ? T : NIL;
  stream->scache = (options & OP_SHORTCACHE) ? T : NIL;
  stream->silent = (options & OP_SILENT) ? T : NIL;
  stream->halfopen = (options & OP_HALFOPEN) ? T : NIL;
  stream->secure = (options & OP_SECURE) ? T : NIL;
  stream->tryssl = (options & OP_TRYSSL) ? T : NIL;
  stream->mulnewsrc = (options & OP_MULNEWSRC) ? T : NIL;
  stream->nokod = (options & OP_NOKOD) ? T : NIL;
  stream->sniff = (options & OP_SNIFF) ? T : NIL;
  stream->perm_seen = stream->perm_deleted = stream->perm_flagged =
    stream->perm_answered = stream->perm_draft = stream->kwd_create = NIL;
  stream->uid_nosticky = (d->flags & DR_NOSTICKY) ? T : NIL;
  stream->uid_last = 0;		/* default UID validity */
  stream->uid_validity = (unsigned long) time (0);
				/* have driver open, flush if failed */
  return ((*d->open) (stream)) ? stream : mail_close (stream);
}

/* Mail close
 * Accepts: mail stream
 *	    close options
 * Returns: NIL, always
 */

MAILSTREAM *mail_close_full (MAILSTREAM *stream,long options)
{
  int i;
  if (stream) {			/* make sure argument given */
				/* do the driver's close action */
    if (stream->dtb) (*stream->dtb->close) (stream,options);
    stream->dtb = NIL;		/* resign driver */
    if (stream->mailbox) fs_give ((void **) &stream->mailbox);
    if (stream->original_mailbox)
      fs_give ((void **) &stream->original_mailbox);
    if (stream->snarf.name) fs_give ((void **) &stream->snarf.name);
    stream->sequence++;		/* invalidate sequence */
				/* flush user flags */
    for (i = 0; i < NUSERFLAGS; i++)
      if (stream->user_flags[i]) fs_give ((void **) &stream->user_flags[i]);
    mail_free_cache (stream);	/* finally free the stream's storage */
    if (mailfreestreamsparep && stream->sparep)
      (*mailfreestreamsparep) (&stream->sparep);
    if (!stream->use) fs_give ((void **) &stream);
  }
  return NIL;
}

/* Mail make handle
 * Accepts: mail stream
 * Returns: handle
 *
 *  Handles provide a way to have multiple pointers to a stream yet allow the
 * stream's owner to nuke it or recycle it.
 */

MAILHANDLE *mail_makehandle (MAILSTREAM *stream)
{
  MAILHANDLE *handle = (MAILHANDLE *) fs_get (sizeof (MAILHANDLE));
  handle->stream = stream;	/* copy stream */
				/* and its sequence */
  handle->sequence = stream->sequence;
  stream->use++;		/* let stream know another handle exists */
  return handle;
}


/* Mail release handle
 * Accepts: Mail handle
 */

void mail_free_handle (MAILHANDLE **handle)
{
  MAILSTREAM *s;
  if (*handle) {		/* only free if exists */
				/* resign stream, flush unreferenced zombies */
    if ((!--(s = (*handle)->stream)->use) && !s->dtb) fs_give ((void **) &s);
    fs_give ((void **) handle);	/* now flush the handle */
  }
}


/* Mail get stream handle
 * Accepts: Mail handle
 * Returns: mail stream or NIL if stream gone
 */

MAILSTREAM *mail_stream (MAILHANDLE *handle)
{
  MAILSTREAM *s = handle->stream;
  return (s->dtb && (handle->sequence == s->sequence)) ? s : NIL;
}

/* Mail fetch cache element
 * Accepts: mail stream
 *	    message # to fetch
 * Returns: cache element of this message
 * Can also be used to create cache elements for new messages.
 */

MESSAGECACHE *mail_elt (MAILSTREAM *stream,unsigned long msgno)
{
  if (msgno < 1 || msgno > stream->nmsgs) {
    char tmp[MAILTMPLEN];
    sprintf (tmp,"Bad msgno %lu in mail_elt, nmsgs = %lu, mbx=%.80s",
	     msgno,stream->nmsgs,stream->mailbox ? stream->mailbox : "???");
    fatal (tmp);
  }
  return (MESSAGECACHE *) (*mailcache) (stream,msgno,CH_MAKEELT);
}


/* Mail fetch fast information
 * Accepts: mail stream
 *	    sequence
 *	    option flags
 *
 * Generally, mail_fetch_structure is preferred
 */

void mail_fetch_fast (MAILSTREAM *stream,char *sequence,long flags)
{
  				/* do the driver's action */
  if (stream->dtb && stream->dtb->fast)
    (*stream->dtb->fast) (stream,sequence,flags);
}


/* Mail fetch flags
 * Accepts: mail stream
 *	    sequence
 *	    option flags
 */

void mail_fetch_flags (MAILSTREAM *stream,char *sequence,long flags)
{
  				/* do the driver's action */
  if (stream->dtb && stream->dtb->msgflags)
    (*stream->dtb->msgflags) (stream,sequence,flags);
}

/* Mail fetch message overview
 * Accepts: mail stream
 *	    UID sequence to fetch
 *	    pointer to overview return function
 */

void mail_fetch_overview (MAILSTREAM *stream,char *sequence,overview_t ofn)
{
  if (stream->dtb && mail_uid_sequence (stream,sequence) &&
      !(stream->dtb->overview && (*stream->dtb->overview) (stream,ofn)) &&
      mail_ping (stream))
    mail_fetch_overview_default (stream,ofn);
}


/* Mail fetch message overview using sequence numbers instead of UIDs
 * Accepts: mail stream
 *	    sequence to fetch
 *	    pointer to overview return function
 */

void mail_fetch_overview_sequence (MAILSTREAM *stream,char *sequence,
				   overview_t ofn)
{
  if (stream->dtb && mail_sequence (stream,sequence) &&
      !(stream->dtb->overview && (*stream->dtb->overview) (stream,ofn)) &&
      mail_ping (stream))
    mail_fetch_overview_default (stream,ofn);
}


/* Mail fetch message overview default handler
 * Accepts: mail stream with sequence bits lit
 *	    pointer to overview return function
 */

void mail_fetch_overview_default (MAILSTREAM *stream,overview_t ofn)
{
  MESSAGECACHE *elt;
  ENVELOPE *env;
  OVERVIEW ov;
  unsigned long i;
  ov.optional.lines = 0;
  ov.optional.xref = NIL;
  for (i = 1; i <= stream->nmsgs; i++)
    if (((elt = mail_elt (stream,i))->sequence) &&
	(env = mail_fetch_structure (stream,i,NIL,NIL)) && ofn) {
      ov.subject = env->subject;
      ov.from = env->from;
      ov.date = env->date;
      ov.message_id = env->message_id;
      ov.references = env->references;
      ov.optional.octets = elt->rfc822_size;
      (*ofn) (stream,mail_uid (stream,i),&ov,i);
    }
}

/* Mail fetch message structure
 * Accepts: mail stream
 *	    message # to fetch
 *	    pointer to return body
 *	    option flags
 * Returns: envelope of this message, body returned in body value
 *
 * Fetches the "fast" information as well
 */

ENVELOPE *mail_fetch_structure (MAILSTREAM *stream,unsigned long msgno,
				BODY **body,long flags)
{
  ENVELOPE **env;
  BODY **b;
  MESSAGECACHE *elt;
  char c,*s,*hdr;
  unsigned long hdrsize;
  STRING bs;
				/* do the driver's action if specified */
  if (stream->dtb && stream->dtb->structure)
    return (*stream->dtb->structure) (stream,msgno,body,flags);
  if (flags & FT_UID) {		/* UID form of call */
    if (msgno = mail_msgno (stream,msgno)) flags &= ~FT_UID;
    else return NIL;		/* must get UID/msgno map first */
  }
  elt = mail_elt (stream,msgno);/* get elt for real message number */
  if (stream->scache) {		/* short caching */
    if (msgno != stream->msgno){/* garbage collect if not same message */
      mail_gc (stream,GC_ENV | GC_TEXTS);
      stream->msgno = msgno;	/* this is the current message now */
    }
    env = &stream->env;		/* get pointers to envelope and body */
    b = &stream->body;
  }
  else {			/* get pointers to elt envelope and body */
    env = &elt->private.msg.env;
    b = &elt->private.msg.body;
  }

  if (stream->dtb && ((body && !*b) || !*env || (*env)->incomplete)) {
    mail_free_envelope (env);	/* flush old envelope and body */
    mail_free_body (b);
				/* see if need to fetch the whole thing */
    if (body || !elt->rfc822_size) {
      s = (*stream->dtb->header) (stream,msgno,&hdrsize,flags & ~FT_INTERNAL);
				/* make copy in case body fetch smashes it */
      hdr = (char *) memcpy (fs_get ((size_t) hdrsize+1),s,(size_t) hdrsize);
      hdr[hdrsize] = '\0';	/* tie off header */
      (*stream->dtb->text) (stream,msgno,&bs,(flags & ~FT_INTERNAL) | FT_PEEK);
      if (!elt->rfc822_size) elt->rfc822_size = hdrsize + SIZE (&bs);
      if (body)			/* only parse body if requested */
	rfc822_parse_msg (env,b,hdr,hdrsize,&bs,BADHOST,stream->dtb->flags);
      else
	rfc822_parse_msg (env,NIL,hdr,hdrsize,NIL,BADHOST,stream->dtb->flags);
      fs_give ((void **) &hdr);	/* flush header */
    }