mtx.c

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  return ret;			/* return success */
}

/* Mtx Mail status
 * Accepts: mail stream
 *	    mailbox name
 *	    status flags
 * Returns: T on success, NIL on failure
 */

long mtx_status (MAILSTREAM *stream,char *mbx,long flags)
{
  MAILSTATUS status;
  unsigned long i;
  MAILSTREAM *tstream = NIL;
  MAILSTREAM *systream = NIL;
				/* make temporary stream (unless this mbx) */
  if (!stream && !(stream = tstream =
		   mail_open (NIL,mbx,OP_READONLY|OP_SILENT))) return NIL;
  status.flags = flags;		/* return status values */
  status.messages = stream->nmsgs;
  status.recent = stream->recent;
  if (flags & SA_UNSEEN)	/* must search to get unseen messages */
    for (i = 1,status.unseen = 0; i <= stream->nmsgs; i++)
      if (!mail_elt (stream,i)->seen) status.unseen++;
  status.uidnext = stream->uid_last + 1;
  status.uidvalidity = stream->uid_validity;
				/* calculate post-snarf results */
  if (!status.recent && stream->inbox &&
      (systream = mail_open (NIL,sysinbox (),OP_READONLY|OP_SILENT))) {
    status.messages += systream->nmsgs;
    status.recent += systream->recent;
    if (flags & SA_UNSEEN)	/* must search to get unseen messages */
      for (i = 1; i <= systream->nmsgs; i++)
	if (!mail_elt (systream,i)->seen) status.unseen++;
				/* kludge but probably good enough */
    status.uidnext += systream->nmsgs;
  }
  MM_STATUS(stream,mbx,&status);/* pass status to main program */
  if (tstream) mail_close (tstream);
  if (systream) mail_close (systream);
  return T;			/* success */
}

/* MTX mail open
 * Accepts: stream to open
 * Returns: stream on success, NIL on failure
 */

MAILSTREAM *mtx_open (MAILSTREAM *stream)
{
  int fd,ld;
  char tmp[MAILTMPLEN];
  blocknotify_t bn = (blocknotify_t) mail_parameters (NIL,GET_BLOCKNOTIFY,NIL);
				/* return prototype for OP_PROTOTYPE call */
  if (!stream) return user_flags (&mtxproto);
  if (stream->local) fatal ("mtx recycle stream");
  user_flags (stream);		/* set up user flags */
				/* canonicalize the mailbox name */
  if (!mtx_file (tmp,stream->mailbox)) {
    sprintf (tmp,"Can't open - invalid name: %.80s",stream->mailbox);
    MM_LOG (tmp,ERROR);
  }
  if (stream->rdonly ||
      (fd = open (tmp,O_RDWR,NIL)) < 0) {
    if ((fd = open (tmp,O_RDONLY,NIL)) < 0) {
      sprintf (tmp,"Can't open mailbox: %.80s",strerror (errno));
      MM_LOG (tmp,ERROR);
      return NIL;
    }
    else if (!stream->rdonly) {	/* got it, but readonly */
      MM_LOG ("Can't get write access to mailbox, access is readonly",WARN);
      stream->rdonly = T;
    }
  }
  stream->local = fs_get (sizeof (MTXLOCAL));
  LOCAL->fd = fd;		/* bind the file */
  LOCAL->buf = (char *) fs_get (CHUNKSIZE);
  LOCAL->buflen = CHUNKSIZE - 1;
				/* note if an INBOX or not */
  stream->inbox = !compare_cstring (stream->mailbox,"INBOX");
  fs_give ((void **) &stream->mailbox);
  stream->mailbox = cpystr (tmp);
				/* get shared parse permission */
  if ((ld = lockfd (fd,tmp,LOCK_SH)) < 0) {
    MM_LOG ("Unable to lock open mailbox",ERROR);
    return NIL;
  }
  (*bn) (BLOCK_FILELOCK,NIL);
  flock (LOCAL->fd,LOCK_SH);	/* lock the file */
  (*bn) (BLOCK_NONE,NIL);
  unlockfd (ld,tmp);		/* release shared parse permission */
  LOCAL->filesize = 0;		/* initialize parsed file size */
				/* time not set up yet */
  LOCAL->lastsnarf = LOCAL->filetime = 0;
  LOCAL->mustcheck = LOCAL->shouldcheck = NIL;
  stream->sequence++;		/* bump sequence number */
				/* 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 (char *) 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)
{
  time_t tp[2];
  struct stat sbuf;
  if (!stream->rdonly) {	/* make sure the update takes */
    fsync (LOCAL->fd);
    fstat (LOCAL->fd,&sbuf);	/* get current write time */
    tp[1] = LOCAL->filetime = sbuf.st_mtime;
    tp[0] = time (0);		/* make sure read comes after all that */
    utime (stream->mailbox,tp);
  }
}


/* 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 = lockfd (LOCAL->fd,lock,LOCK_SH)) >= 0)) {
				/* parse resulting mailbox */
      r = (mtx_parse (stream)) ? T : NIL;
      unlockfd (ld,lock);	/* release shared parse/append permission */
    }
    if (LOCAL) {		/* stream must still be alive */
				/* snarf if this is a read-write inbox */
      if (stream->inbox && !stream->rdonly) {
	mtx_snarf (stream);
	fstat (LOCAL->fd,&sbuf);/* see if file changed now */
	if ((sbuf.st_size != LOCAL->filesize) &&
	    ((ld = lockfd (LOCAL->fd,lock,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 snarf messages from system inbox
 * Accepts: MAIL stream
 */

void mtx_snarf (MAILSTREAM *stream)
{
  unsigned long i = 0;
  unsigned long j,r,hdrlen,txtlen;
  struct stat sbuf;
  char *hdr,*txt,lock[MAILTMPLEN],tmp[MAILTMPLEN];
  MESSAGECACHE *elt;
  MAILSTREAM *sysibx = NIL;
  int ld;
				/* give up if can't get exclusive permission */
  if ((time (0) >= (LOCAL->lastsnarf +
		    (long) mail_parameters (NIL,GET_SNARFINTERVAL,NIL))) &&
      strcmp (sysinbox (),stream->mailbox) &&
      ((ld = lockfd (LOCAL->fd,lock,LOCK_EX)) >= 0)) {
    MM_CRITICAL (stream);	/* go critical */
				/* sizes match and anything in sysinbox? */
    if (!stat (sysinbox (),&sbuf) && sbuf.st_size &&
	!fstat (LOCAL->fd,&sbuf) && (sbuf.st_size == LOCAL->filesize) && 
	(sysibx = mail_open (sysibx,sysinbox (),OP_SILENT)) &&
	(!sysibx->rdonly) && (r = sysibx->nmsgs)) {
				/* yes, go to end of file in our mailbox */
      lseek (LOCAL->fd,sbuf.st_size,L_SET);
				/* for each message in sysibx mailbox */
      while (r && (++i <= sysibx->nmsgs)) {
				/* snarf message from system INBOX */
	hdr = cpystr (mail_fetchheader_full (sysibx,i,NIL,&hdrlen,NIL));
	txt = mail_fetchtext_full (sysibx,i,&txtlen,FT_PEEK);
				/* if have a message */
	if (j = hdrlen + txtlen) {
				/* calculate header line */
	  mail_date (LOCAL->buf,elt = mail_elt (sysibx,i));
	  sprintf (LOCAL->buf + strlen (LOCAL->buf),