mtxnt.c

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				/* parse mailbox */
  stream->nmsgs = stream->recent = 0;
  if (mtx_ping (stream) && !stream->nmsgs)
    mm_log ("Mailbox is empty",(long) NIL);
  if (!LOCAL) return NIL;	/* failure if stream died */
  stream->perm_seen = stream->perm_deleted =
    stream->perm_flagged = stream->perm_answered = stream->perm_draft =
      stream->rdonly ? NIL : T;
  stream->perm_user_flags = stream->rdonly ? NIL : 0xffffffff;
  return stream;		/* return stream to caller */
}

/* MTX mail close
 * Accepts: MAIL stream
 *	    close options
 */

void mtx_close (MAILSTREAM *stream,long options)
{
  if (stream && LOCAL) {	/* only if a file is open */
    int silent = stream->silent;
    stream->silent = T;		/* note this stream is dying */
    if (options & CL_EXPUNGE) mtx_expunge (stream,NIL,NIL);
    stream->silent = silent;	/* restore previous status */
    flock (LOCAL->fd,LOCK_UN);	/* unlock local file */
    close (LOCAL->fd);		/* close the local file */
				/* free local text buffer */
    if (LOCAL->buf) fs_give ((void **) &LOCAL->buf);
				/* nuke the local data */
    fs_give ((void **) &stream->local);
    stream->dtb = NIL;		/* log out the DTB */
  }
}


/* MTX mail fetch flags
 * Accepts: MAIL stream
 *	    sequence
 *	    option flags
 * Sniffs at file to see if some other process changed the flags
 */

void mtx_flags (MAILSTREAM *stream,char *sequence,long flags)
{
  unsigned long i;
  if (mtx_ping (stream) && 	/* ping mailbox, get new status for messages */
      ((flags & FT_UID) ? mail_uid_sequence (stream,sequence) :
       mail_sequence (stream,sequence)))
    for (i = 1; i <= stream->nmsgs; i++) 
      if (mail_elt (stream,i)->sequence) mtx_elt (stream,i);
}

/* MTX mail fetch message header
 * Accepts: MAIL stream
 *	    message # to fetch
 *	    pointer to returned header text length
 *	    option flags
 * Returns: message header in RFC822 format
 */

char *mtx_header (MAILSTREAM *stream,unsigned long msgno,unsigned long *length,
		  long flags)
{
  *length = 0;			/* default to empty */
  if (flags & FT_UID) return "";/* UID call "impossible" */
				/* get to header position */
  lseek (LOCAL->fd,mtx_hdrpos (stream,msgno,length),L_SET);
				/* is buffer big enough? */
  if (*length > LOCAL->buflen) {
    fs_give ((void **) &LOCAL->buf);
    LOCAL->buf = (char *) fs_get ((LOCAL->buflen = *length) + 1);
  }
  LOCAL->buf[*length] = '\0';	/* tie off string */
				/* slurp the data */
  read (LOCAL->fd,LOCAL->buf,*length);
  return LOCAL->buf;
}

/* MTX mail fetch message text (body only)
 * Accepts: MAIL stream
 *	    message # to fetch
 *	    pointer to returned header text length
 *	    option flags
 * Returns: T, always
 */

long mtx_text (MAILSTREAM *stream,unsigned long msgno,STRING *bs,long flags)
{
  FDDATA d;
  unsigned long i,j;
  MESSAGECACHE *elt;
				/* UID call "impossible" */
  if (flags & FT_UID) return NIL;
  elt = mtx_elt (stream,msgno);	/* get message status */
				/* if message not seen */
  if (!(flags & FT_PEEK) && !elt->seen) {
    elt->seen = T;		/* mark message as seen */
				/* recalculate status */
    mtx_update_status (stream,msgno,NIL);
    mm_flags (stream,msgno);
  }
				/* find header position */
  i = mtx_hdrpos (stream,msgno,&j);
  d.fd = LOCAL->fd;		/* set up file descriptor */
  d.pos = i + j;
  d.chunk = LOCAL->buf;	/* initial buffer chunk */
  d.chunksize = CHUNKSIZE;
  INIT (bs,fd_string,&d,elt->rfc822_size - j);
  return T;			/* success */
}

/* MTX mail modify flags
 * Accepts: MAIL stream
 *	    sequence
 *	    flag(s)
 *	    option flags
 */

void mtx_flag (MAILSTREAM *stream,char *sequence,char *flag,long flags)
{
  struct utimbuf times;
  struct stat sbuf;
  if (!stream->rdonly) {	/* make sure the update takes */
    fsync (LOCAL->fd);
    fstat (LOCAL->fd,&sbuf);	/* get current write time */
    times.modtime = LOCAL->filetime = sbuf.st_mtime;
    times.actime = time (0);	/* make sure read comes after all that */
    utime (stream->mailbox,&times);
  }
}


/* MTX mail per-message modify flags
 * Accepts: MAIL stream
 *	    message cache element
 */

void mtx_flagmsg (MAILSTREAM *stream,MESSAGECACHE *elt)
{
  struct stat sbuf;
				/* maybe need to do a checkpoint? */
  if (LOCAL->filetime && !LOCAL->shouldcheck) {
    fstat (LOCAL->fd,&sbuf);	/* get current write time */
    if (LOCAL->filetime < sbuf.st_mtime) LOCAL->shouldcheck = T;
    LOCAL->filetime = 0;	/* don't do this test for any other messages */
  }
				/* recalculate status */
  mtx_update_status (stream,elt->msgno,NIL);
}

/* MTX mail ping mailbox
 * Accepts: MAIL stream
 * Returns: T if stream still alive, NIL if not
 */

long mtx_ping (MAILSTREAM *stream)
{
  unsigned long i = 1;
  long r = T;
  int ld;
  char lock[MAILTMPLEN];
  struct stat sbuf;
  if (stream && LOCAL) {	/* only if stream already open */
    fstat (LOCAL->fd,&sbuf);	/* get current file poop */
    if (LOCAL->filetime && !(LOCAL->mustcheck || LOCAL->shouldcheck) &&
	(LOCAL->filetime < sbuf.st_mtime)) LOCAL->shouldcheck = T;
				/* check for changed message status */
    if (LOCAL->mustcheck || LOCAL->shouldcheck) {
      LOCAL->filetime = sbuf.st_mtime;
      if (LOCAL->shouldcheck)	/* babble when we do this unilaterally */
	mm_notify (stream,"[CHECK] Checking for flag updates",NIL);
      while (i <= stream->nmsgs) mtx_elt (stream,i++);
      LOCAL->mustcheck = LOCAL->shouldcheck = NIL;
    }
				/* get shared parse/append permission */
    if ((sbuf.st_size != LOCAL->filesize) &&
	((ld = lockname (lock,stream->mailbox,LOCK_SH)) >= 0)) {
				/* parse resulting mailbox */
      r = (mtx_parse (stream)) ? T : NIL;
      unlockfd (ld,lock);	/* release shared parse/append permission */
    }
  }
  return r;			/* return result of the parse */
}


/* MTX mail check mailbox (reparses status too)
 * Accepts: MAIL stream
 */

void mtx_check (MAILSTREAM *stream)
{
				/* mark that a check is desired */
  if (LOCAL) LOCAL->mustcheck = T;
  if (mtx_ping (stream)) mm_log ("Check completed",(long) NIL);
}

/* MTX mail expunge mailbox
 *	    sequence to expunge if non-NIL
 *	    expunge options
 * Returns: T, always
 */

long mtx_expunge (MAILSTREAM *stream,char *sequence,long options)
{
  long ret;
  struct utimbuf times;
  struct stat sbuf;
  off_t pos = 0;
  int ld;
  unsigned long i = 1;
  unsigned long j,k,m,recent;
  unsigned long n = 0;
  unsigned long delta = 0;
  char lock[MAILTMPLEN];
  MESSAGECACHE *elt;
  if (!(ret = (sequence ? ((options & EX_UID) ?
			   mail_uid_sequence (stream,sequence) :
			   mail_sequence (stream,sequence)) : LONGT) &&
	mtx_ping (stream)));	/* parse sequence if given, ping stream */
  else if (stream->rdonly) mm_log ("Expunge ignored on readonly mailbox",WARN);
  else {
    if (LOCAL->filetime && !LOCAL->shouldcheck) {
      fstat (LOCAL->fd,&sbuf);	/* get current write time */
      if (LOCAL->filetime < sbuf.st_mtime) LOCAL->shouldcheck = T;
    }
				/* get exclusive parse/append permission */
    if ((ld = lockname (lock,stream->mailbox,LOCK_EX)) < 0)
      mm_log ("Unable to lock expunge mailbox",ERROR);
				/* make sure see any newly-arrived messages */
    else if (!mtx_parse (stream));
				/* get exclusive access */
    else if (flock (LOCAL->fd,LOCK_EX|LOCK_NB)) {
      flock (LOCAL->fd,LOCK_SH);/* recover previous lock */
      mm_log ("Can't expunge because mailbox is in use by another process",
	      ERROR);
      unlockfd (ld,lock);	/* release exclusive parse/append permission */
    }

    else {
      mm_critical (stream);	/* go critical */
      recent = stream->recent;	/* get recent now that pinged and locked */
				/* for each message */
      while (i <= stream->nmsgs) {
				/* get cache element */
	elt = mtx_elt (stream,i);
				/* number of bytes to smash or preserve */
	k = elt->private.special.text.size + elt->rfc822_size;
				/* if need to expunge this message */
	if (elt->deleted && (sequence ? elt->sequence : T)) {
				/* if recent, note one less recent message */
	  if (elt->recent) --recent;
	  delta += k;		/* number of bytes to delete */
				/* notify upper levels */
	  mail_expunged (stream,i);
	  n++;			/* count up one more expunged message */
	}
	else if (i++ && delta) {/* preserved message */
				/* first byte to preserve */
	  j = elt->private.special.offset;
	  do {			/* read from source position */
	    m = min (k,LOCAL->buflen);
	    lseek (LOCAL->fd,j,L_SET);
	    read (LOCAL->fd,LOCAL->buf,m);
	    pos = j - delta;	/* write to destination position */
	    while (T) {
	      lseek (LOCAL->fd,pos,L_SET);
	      if (write (LOCAL->fd,LOCAL->buf,m) > 0) break;
	      mm_notify (stream,strerror (errno),WARN);
	      mm_diskerror (stream,errno,T);
	    }
	    pos += m;		/* new position */
	    j += m;		/* next chunk, perhaps */
	  } while (k -= m);	/* until done */
				/* note the new address of this text */
	  elt->private.special.offset -= delta;
	}
				/* preserved but no deleted messages */
	else pos = elt->private.special.offset + k;
      }
      if (n) {			/* truncate file after last message */
	if (pos != (LOCAL->filesize -= delta)) {
	  sprintf (LOCAL->buf,
		   "Calculated size mismatch %lu != %lu, delta = %lu",
		   (unsigned long) pos,(unsigned long) LOCAL->filesize,delta);
	  mm_log (LOCAL->buf,WARN);
	  LOCAL->filesize = pos;/* fix it then */
	}
	ftruncate (LOCAL->fd,LOCAL->filesize);
	sprintf (LOCAL->buf,"Expunged %lu messages",n);
				/* output the news */
	mm_log (LOCAL->buf,(long) NIL);
      }
      else mm_log ("No messages deleted, so no update needed",(long) NIL);
      fsync (LOCAL->fd);	/* force disk update */
      fstat (LOCAL->fd,&sbuf);	/* get new write time */
      times.modtime = LOCAL->filetime = sbuf.st_mtime;
      times.actime = time (0);	/* reset atime to now */
      utime (stream->mailbox,&times);
      mm_nocritical (stream);	/* release critical */
				/* notify upper level of new mailbox size */
      mail_exists (stream,stream->nmsgs);
      mail_recent (stream,recent);
      flock (LOCAL->fd,LOCK_SH);/* allow sharers again */
      unlockfd (ld,lock);	/* release exclusive parse/append permission */
    }
  }
  return ret;
}

/* MTX mail copy message(s)
 * Accepts: MAIL stream
 *	    sequence
 *	    destination mailbox
 *	    copy options
 * Returns: T if success, NIL if failed
 */

long mtx_copy (MAILSTREAM *stream,char *sequence,char *mailbox,long options)
{
  struct stat sbuf;
  struct utimbuf times;
  MESSAGECACHE *elt;
  unsigned long i,j,k;
  long ret = LONGT;
  int fd,ld;
  char file[MAILTMPLEN],lock[MAILTMPLEN];
  mailproxycopy_t pc =
    (mailproxycopy_t) mail_parameters (stream,GET_MAILPROXYCOPY,NIL);
				/* make sure valid mailbox */
  if (!mtx_isvalid (mailbox,file)) switch (errno) {
  case ENOENT:			/* no such file? */
    mm_notify (stream,"[TRYCREATE] Must create mailbox before copy",NIL);
    return NIL;
  case 0:			/* merely empty file? */
    break;
  case EACCES:			/* file protected */
    sprintf (LOCAL->buf,"Can't access destination: %.80s",mailbox);
    MM_LOG (LOCAL->buf,ERROR);
    return NIL;
  case EINVAL:
    if (pc) return (*pc) (stream,sequence,mailbox,options);
    sprintf (LOCAL->buf,"Invalid MTX-format mailbox name: %.80s",mailbox);
    mm_log (LOCAL->buf,ERROR);
    return NIL;
  default:
    if (pc) return (*pc) (stream,sequence,mailbox,options);
    sprintf (LOCAL->buf,"Not a MTX-format mailbox: %.80s",mailbox);
    mm_log (LOCAL->buf,ERROR);
    return NIL;
  }
  if (!((options & CP_UID) ? mail_uid_sequence (stream,sequence) :
	mail_sequence (stream,sequence))) return NIL;
				/* got file? */
  if ((fd = open (file,O_BINARY|O_RDWR|O_CREAT,S_IREAD|S_IWRITE)) < 0) {
    sprintf (LOCAL->buf,"Unable to open copy mailbox: %.80s",strerror (errno));
    mm_log (LOCAL->buf,ERROR);
    return NIL;
  }
  mm_critical (stream);		/* go critical */
				/* get exclusive parse/append permission */
  if (flock (fd,LOCK_SH) || ((ld = lockname (lock,file,LOCK_EX)) < 0)) {
    mm_log ("Unable to lock copy mailbox",ERROR);
    mm_nocritical (stream);
    return NIL;
  }
  fstat (fd,&sbuf);		/* get current file size */
  lseek (fd,sbuf.st_size,L_SET);/* move to end of file */

				/* for each requested message */
  for (i = 1; ret && (i <= stream->nmsgs); i++) 
    if ((elt = mail_elt (stream,i))->sequence) {
      lseek (LOCAL->fd,elt->private.special.offset,L_SET);
				/* number of bytes to copy */
      k = elt->private.special.text.size + elt->rfc822_size;
      do {			/* read from source position */
	j = min (k,LOCAL->buflen);
	read (LOCAL->fd,LOCAL->buf,j);
	if (write (fd,LOCAL->buf,j) < 0) ret = NIL;
      } while (ret && (k -= j));/* until done */
    }
				/* make sure all the updates take */
  if (!(ret && (ret = !fsync (fd)))) {
    sprintf (LOCAL->buf,"Unable to write message: %s",strerror (errno));
    mm_log (LOCAL->buf,ERROR);
    ftruncate (fd,sbuf.st_size);
  }
				/* set atime to now-1 if successful copy */
  if (ret) times.actime = time (0) - 1;
				/* else preserved \Marked status */
  else times.actime = (sbuf.st_ctime > sbuf.st_atime) ?
	 sbuf.st_atime : time (0);
  times.modtime = sbuf.st_mtime;/* preserve mtime */
  utime (file,&times);		/* set the times */
  unlockfd (ld,lock);		/* release exclusive parse/append permission */
  close (fd);			/* close the file */
  mm_nocritical (stream);	/* release critical */
				/* delete all requested messages */
  if (ret && (options & CP_MOVE)) {
    for (i = 1; i <= stream->nmsgs; i++)
      if ((elt = mtx_elt (stream,i))->sequence) {
	elt->deleted = T;	/* mark message deleted */
				/* recalculate status */
	mtx_update_status (stream,i,NIL);
      }
    if (!stream->rdonly) {	/* make sure the update takes */
      fsync (LOCAL->fd);
      fstat (LOCAL->fd,&sbuf);	/* get current write time */
      times.modtime = LOCAL->filetime = sbuf.st_mtime;
      times.actime = time (0);	/* make sure atime remains greater */
      utime (stream->mailbox,&times);