mtx.c

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    for (uf = 0; i; uf |= 1 << (29 - find_rightmost_bit (&i)));
    if (date) {			/* parse date if given */
      if (!mail_parse_date (&elt,date)) {
	sprintf (tmp,"Bad date in append: %.80s",date);
	MM_LOG (tmp,ERROR);
	ret = NIL;		/* mark failure */
	break;
      }
      mail_date (tmp,&elt);	/* write preseved date */
    }
    else internal_date (tmp);	/* get current date in IMAP format */
				/* write header */
    if (fprintf (df,"%s,%lu;%010lo%02lo\015\012",tmp,i = SIZE (message),uf,
		 (unsigned long) f) < 0) ret = NIL;
    else {			/* write message */
      if (i) do c = 0xff & SNX (message);
      while ((putc (c,df) != EOF) && --i);
				/* get next message */
      if (i || !MM_APPEND (af) (stream,data,&flags,&date,&message)) ret = NIL;
    }
  } while (ret && message);
				/* if error... */
  if (!ret || (fflush (df) == EOF)) {
    ftruncate (fd,sbuf.st_size);/* revert file */
    close (fd);			/* make sure fclose() doesn't corrupt us */
    if (errno) {
      sprintf (tmp,"Message append failed: %s",strerror (errno));
      MM_LOG (tmp,ERROR);
    }
    ret = NIL;
  }
  if (ret) tp[0] = time (0) - 1;/* set atime to now-1 if successful copy */
				/* else preserve \Marked status */
  else tp[0] = (sbuf.st_ctime > sbuf.st_atime) ? sbuf.st_atime : time(0);
  tp[1] = sbuf.st_mtime;	/* preserve mtime */
  utime (file,tp);		/* set the times */
  fclose (df);			/* close the file */
  unlockfd (ld,lock);		/* release exclusive parse/append permission */
  MM_NOCRITICAL (stream);	/* release critical */
  if (ret && mail_parameters (NIL,GET_APPENDUID,NIL))
    MM_LOG ("Can not return meaningful APPENDUID with this mailbox format",
	    WARN);
  return ret;
}

/* Internal routines */


/* MTX mail generate file string
 * Accepts: temporary buffer to write into
 *	    mailbox name string
 * Returns: local file string or NIL if failure
 */

char *mtx_file (char *dst,char *name)
{
  char tmp[MAILTMPLEN];
  char *s = mailboxfile (dst,name);
				/* return our standard inbox */
  return (s && !*s) ? mailboxfile (dst,mtx_isvalid ("~/INBOX",tmp) ?
				   "~/INBOX" : "INBOX.MTX") : s;
}

/* MTX mail parse mailbox
 * Accepts: MAIL stream
 * Returns: T if parse OK
 *	    NIL if failure, stream aborted
 */

long mtx_parse (MAILSTREAM *stream)
{
  struct stat sbuf;
  MESSAGECACHE *elt = NIL;
  unsigned char c,*s,*t,*x;
  char tmp[MAILTMPLEN];
  unsigned long i,j;
  long curpos = LOCAL->filesize;
  long nmsgs = stream->nmsgs;
  long recent = stream->recent;
  short added = NIL;
  short silent = stream->silent;
  fstat (LOCAL->fd,&sbuf);	/* get status */
  if (sbuf.st_size < curpos) {	/* sanity check */
    sprintf (tmp,"Mailbox shrank from %lu to %lu!",
	     (unsigned long) curpos,(unsigned long) sbuf.st_size);
    MM_LOG (tmp,ERROR);
    mtx_close (stream,NIL);
    return NIL;
  }
  stream->silent = T;		/* don't pass up exists events yet */
  while (sbuf.st_size - curpos){/* while there is stuff to parse */
				/* get to that position in the file */
    lseek (LOCAL->fd,curpos,L_SET);
    if ((i = read (LOCAL->fd,LOCAL->buf,64)) <= 0) {
      sprintf (tmp,"Unable to read internal header at %lu, size = %lu: %s",
	       (unsigned long) curpos,(unsigned long) sbuf.st_size,
	       i ? strerror (errno) : "no data read");
      MM_LOG (tmp,ERROR);
      mtx_close (stream,NIL);
      return NIL;
    }
    LOCAL->buf[i] = '\0';	/* tie off buffer just in case */
    if (!((s = strchr (LOCAL->buf,'\015')) && (s[1] == '\012'))) {
      sprintf (tmp,"Unable to find CRLF at %lu in %lu bytes, text: %s",
	       (unsigned long) curpos,i,(char *) LOCAL->buf);
      MM_LOG (tmp,ERROR);
      mtx_close (stream,NIL);
      return NIL;
    }
    *s = '\0';			/* tie off header line */
    i = (s + 2) - LOCAL->buf;	/* note start of text offset */
    if (!((s = strchr (LOCAL->buf,',')) && (t = strchr (s+1,';')))) {
      sprintf (tmp,"Unable to parse internal header at %lu: %s",
	       (unsigned long) curpos,(char *) LOCAL->buf);
      MM_LOG (tmp,ERROR);
      mtx_close (stream,NIL);
      return NIL;
    }
    *s++ = '\0'; *t++ = '\0';	/* tie off fields */

    added = T;			/* note that a new message was added */
				/* swell the cache */
    mail_exists (stream,++nmsgs);
				/* instantiate an elt for this message */
    (elt = mail_elt (stream,nmsgs))->valid = T;
    elt->private.uid = ++stream->uid_last;
				/* note file offset of header */
    elt->private.special.offset = curpos;
				/* in case error */
    elt->private.special.text.size = 0;
				/* header size not known yet */
    elt->private.msg.header.text.size = 0;
    x = s;			/* parse the header components */
    if (mail_parse_date (elt,LOCAL->buf) &&
	(elt->rfc822_size = strtoul (s,(char **) &s,10)) && (!(s && *s)) &&
	isdigit (t[0]) && isdigit (t[1]) && isdigit (t[2]) &&
	isdigit (t[3]) && isdigit (t[4]) && isdigit (t[5]) &&
	isdigit (t[6]) && isdigit (t[7]) && isdigit (t[8]) &&
	isdigit (t[9]) && isdigit (t[10]) && isdigit (t[11]) && !t[12])
      elt->private.special.text.size = i;
    else {			/* oops */
      sprintf (tmp,"Unable to parse internal header elements at %ld: %s,%s;%s",
	       curpos,(char *) LOCAL->buf,(char *) x,(char *) t);
      MM_LOG (tmp,ERROR);
      mtx_close (stream,NIL);
      return NIL;
    }
				/* make sure didn't run off end of file */
    if ((curpos += (elt->rfc822_size + i)) > sbuf.st_size) {
      sprintf (tmp,"Last message (at %lu) runs past end of file (%lu > %lu)",
	       elt->private.special.offset,(unsigned long) curpos,
	       (unsigned long) sbuf.st_size);
      MM_LOG (tmp,ERROR);
      mtx_close (stream,NIL);
      return NIL;
    }
    c = t[10];			/* remember first system flags byte */
    t[10] = '\0';		/* tie off flags */
    j = strtoul (t,NIL,8);	/* get user flags value */
    t[10] = c;			/* restore first system flags byte */
				/* set up all valid user flags (reversed!) */
    while (j) if (((i = 29 - find_rightmost_bit (&j)) < NUSERFLAGS) &&
		  stream->user_flags[i]) elt->user_flags |= 1 << i;
				/* calculate system flags */
    if ((j = ((t[10]-'0') * 8) + t[11]-'0') & fSEEN) elt->seen = T;
    if (j & fDELETED) elt->deleted = T;
    if (j & fFLAGGED) elt->flagged = T;
    if (j & fANSWERED) elt->answered = T;
    if (j & fDRAFT) elt->draft = T;
    if (!(j & fOLD)) {		/* newly arrived message? */
      elt->recent = T;
      recent++;			/* count up a new recent message */
				/* mark it as old */
      mtx_update_status (stream,nmsgs,NIL);
    }
  }
  fsync (LOCAL->fd);		/* make sure all the fOLD flags take */
				/* update parsed file size and time */
  LOCAL->filesize = sbuf.st_size;
  fstat (LOCAL->fd,&sbuf);	/* get status again to ensure time is right */
  LOCAL->filetime = sbuf.st_mtime;
  if (added && !stream->rdonly){/* make sure atime updated */
    time_t tp[2];
    tp[0] = time (0);
    tp[1] = LOCAL->filetime;
    utime (stream->mailbox,tp);
  }
  stream->silent = silent;	/* can pass up events now */
  mail_exists (stream,nmsgs);	/* notify upper level of new mailbox size */
  mail_recent (stream,recent);	/* and of change in recent messages */
  return LONGT;			/* return the winnage */
}

/* MTX get cache element with status updating from file
 * Accepts: MAIL stream
 *	    message number
 * Returns: cache element
 */

MESSAGECACHE *mtx_elt (MAILSTREAM *stream,unsigned long msgno)
{
  MESSAGECACHE *elt = mail_elt (stream,msgno);
  struct {			/* old flags */
    unsigned int seen : 1;
    unsigned int deleted : 1;
    unsigned int flagged : 1;
    unsigned int answered : 1;
    unsigned int draft : 1;
    unsigned long user_flags;
  } old;
  old.seen = elt->seen; old.deleted = elt->deleted; old.flagged = elt->flagged;
  old.answered = elt->answered; old.draft = elt->draft;
  old.user_flags = elt->user_flags;
  mtx_read_flags (stream,elt);
  if ((old.seen != elt->seen) || (old.deleted != elt->deleted) ||
      (old.flagged != elt->flagged) || (old.answered != elt->answered) ||
      (old.draft != elt->draft) || (old.user_flags != elt->user_flags))
    MM_FLAGS (stream,msgno);	/* let top level know */
  return elt;
}

/* MTX read flags from file
 * Accepts: MAIL stream
 * Returns: cache element
 */

void mtx_read_flags (MAILSTREAM *stream,MESSAGECACHE *elt)
{
  unsigned long i,j;
				/* noop if readonly and have valid flags */
  if (stream->rdonly && elt->valid) return;
				/* set the seek pointer */
  lseek (LOCAL->fd,(off_t) elt->private.special.offset +
	 elt->private.special.text.size - 14,L_SET);
				/* read the new flags */
  if (read (LOCAL->fd,LOCAL->buf,12) < 0) {
    sprintf (LOCAL->buf,"Unable to read new status: %s",strerror (errno));
    fatal (LOCAL->buf);
  }
				/* calculate system flags */
  i = (((LOCAL->buf[10]-'0') * 8) + LOCAL->buf[11]-'0');
  elt->seen = i & fSEEN ? T : NIL; elt->deleted = i & fDELETED ? T : NIL;
  elt->flagged = i & fFLAGGED ? T : NIL;
  elt->answered = i & fANSWERED ? T : NIL; elt->draft = i & fDRAFT ? T : NIL;
  LOCAL->buf[10] = '\0';	/* tie off flags */
  j = strtoul(LOCAL->buf,NIL,8);/* get user flags value */
				/* set up all valid user flags (reversed!) */
  while (j) if (((i = 29 - find_rightmost_bit (&j)) < NUSERFLAGS) &&
		stream->user_flags[i]) elt->user_flags |= 1 << i;
  elt->valid = T;		/* have valid flags now */
}

/* MTX update status string
 * Accepts: MAIL stream
 *	    message number
 *	    flag saying whether or not to sync
 */

void mtx_update_status (MAILSTREAM *stream,unsigned long msgno,long syncflag)
{
  time_t tp[2];
  struct stat sbuf;
  MESSAGECACHE *elt = mail_elt (stream,msgno);
  unsigned long j,k = 0;
				/* readonly */
  if (stream->rdonly || !elt->valid) mtx_read_flags (stream,elt);
  else {			/* readwrite */
    j = elt->user_flags;	/* get user flags */
				/* reverse bits (dontcha wish we had CIRC?) */
    while (j) k |= 1 << (29 - find_rightmost_bit (&j));
				/* print new flag string */
    sprintf (LOCAL->buf,"%010lo%02o",k,(unsigned)
	     (fOLD + (fSEEN * elt->seen) + (fDELETED * elt->deleted) +
	      (fFLAGGED * elt->flagged) + (fANSWERED * elt->answered) +
	      (fDRAFT * elt->draft)));
				/* get to that place in the file */
    lseek (LOCAL->fd,(off_t) elt->private.special.offset +
	   elt->private.special.text.size - 14,L_SET);
				/* write new flags */
    write (LOCAL->fd,LOCAL->buf,12);
    if (syncflag) {		/* sync if requested */
      fsync (LOCAL->fd);
      fstat (LOCAL->fd,&sbuf);	/* get new write time */
      tp[1] = LOCAL->filetime = sbuf.st_mtime;
      tp[0] = time (0);		/* make sure read is later */
      utime (stream->mailbox,tp);
    }
  }
}

/* MTX locate header for a message
 * Accepts: MAIL stream
 *	    message number
 *	    pointer to returned header size
 * Returns: position of header in file
 */

unsigned long mtx_hdrpos (MAILSTREAM *stream,unsigned long msgno,
			  unsigned long *size)
{
  unsigned long siz;
  long i = 0;
  int q = 0;
  char *s,tmp[MAILTMPLEN];
  MESSAGECACHE *elt = mtx_elt (stream,msgno);
  unsigned long ret = elt->private.special.offset +
    elt->private.special.text.size;
				/* is header size known? */
  if (!(*size = elt->private.msg.header.text.size)) {
    lseek (LOCAL->fd,ret,L_SET);/* get to header position */
				/* search message for CRLF CRLF */
    for (siz = 1,s = tmp; siz <= elt->rfc822_size; siz++) {
				/* read another buffer as necessary */
      if ((--i <= 0) &&		/* buffer empty? */
	  (read (LOCAL->fd,s = tmp,
		 i = min (elt->rfc822_size - siz,(long) MAILTMPLEN)) < 0))
	return ret;		/* I/O error? */
      switch (q) {		/* sniff at buffer */
      case 0:			/* first character */
	q = (*s++ == '\015') ? 1 : 0;
	break;
      case 1:			/* second character */
	q = (*s++ == '\012') ? 2 : 0;
	break;
      case 2:			/* third character */
	q = (*s++ == '\015') ? 3 : 0;
	break;
      case 3:			/* fourth character */
	if (*s++ == '\012') {	/* have the sequence? */
				/* yes, note for later */
	  elt->private.msg.header.text.size = *size = siz;
	  return ret;
	}
	q = 0;			/* lost... */
	break;
      }
    }
				/* header consumes entire message */
    elt->private.msg.header.text.size = *size = elt->rfc822_size;
  }
  return ret;
}