unix.c

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  unsigned long i,j,k,m;
  char *s,*t,*te,p1[CHUNK];
  char *ret = "";
				/* flush old buffer */
  if (LOCAL->line) fs_give ((void **) &LOCAL->line);
				/* if buffer needs refreshing */
  if (!bs->cursize) SETPOS (bs,GETPOS (bs));
  if (SIZE (bs)) {		/* find newline */
				/* end of fast scan */
    te = (t = (s = bs->curpos) + bs->cursize) - 12;
    while (s < te) if ((*s++ == '\n') || (*s++ == '\n') || (*s++ == '\n') ||
		       (*s++ == '\n') || (*s++ == '\n') || (*s++ == '\n') ||
		       (*s++ == '\n') || (*s++ == '\n') || (*s++ == '\n') ||
		       (*s++ == '\n') || (*s++ == '\n') || (*s++ == '\n')) {
      --s;			/* back up */
      break;			/* exit loop */
    }
				/* final character-at-a-time scan */
    while ((s < t) && (*s != '\n')) ++s;
				/* difficult case if line spans buffer */
    if ((i = s - bs->curpos) == bs->cursize) {
      memcpy (p1,bs->curpos,i);	/* remember what we have so far */
				/* load next buffer */
      SETPOS (bs,k = GETPOS (bs) + i);
				/* end of fast scan */
      te = (t = (s = bs->curpos) + bs->cursize) - 12;
				/* fast scan in overlap buffer */
      while (s < te) if ((*s++ == '\n') || (*s++ == '\n') || (*s++ == '\n') ||
			 (*s++ == '\n') || (*s++ == '\n') || (*s++ == '\n') ||
			 (*s++ == '\n') || (*s++ == '\n') || (*s++ == '\n') ||
			 (*s++ == '\n') || (*s++ == '\n') || (*s++ == '\n')) {
	--s;			/* back up */
	break;			/* exit loop */
      }
				/* final character-at-a-time scan */
      while ((s < t) && (*s != '\n')) ++s;
				/* huge line? */
      if ((j = s - bs->curpos) == bs->cursize) {
	SETPOS (bs,GETPOS (bs) + j);
				/* look for end of line (s-l-o-w!!) */
	for (m = SIZE (bs); m && (SNX (bs) != '\n'); --m,++j);
	SETPOS (bs,k);		/* go back to where it started */
      }

				/* got size of data, make buffer for return */
      ret = LOCAL->line = (char *) fs_get (i + j + 2);
      memcpy (ret,p1,i);	/* copy first chunk */
      while (j) {		/* copy remainder */
	if (!bs->cursize) SETPOS (bs,GETPOS (bs));
	memcpy (ret + i,bs->curpos,k = min (j,bs->cursize));
	i += k;			/* account for this much read in */
	j -= k;
	bs->curpos += k;	/* increment new position */
	bs->cursize -= k;	/* eat that many bytes */
      }
      if (!bs->cursize) SETPOS (bs,GETPOS (bs));
      if (SIZE (bs)) SNX (bs);	/* skip over newline if one seen */
      ret[i++] = '\n';		/* make sure newline at end */
      ret[i] = '\0';		/* makes debugging easier */
    }
    else {			/* this is easy */
      ret = bs->curpos;		/* string it at this position */
      bs->curpos += ++i;	/* increment new position */
      bs->cursize -= i;		/* eat that many bytes */
    }
    *size = i;			/* return that to user */
  }
  else *size = 0;		/* end of data, return empty */
  return ret;
}

/* UNIX make pseudo-header
 * Accepts: MAIL stream
 *	    buffer to write pseudo-header
 * Returns: length of pseudo-header
 */

unsigned long unix_pseudo (MAILSTREAM *stream,char *hdr)
{
  int i;
  char *s,tmp[MAILTMPLEN];
  time_t now = time (0);
  rfc822_fixed_date (tmp);
  sprintf (hdr,"From %s %.24s\nDate: %s\nFrom: %s <%s@%.80s>\nSubject: %s\nMessage-ID: <%lu@%.80s>\nX-IMAP: %010lu %010lu",
	   pseudo_from,ctime (&now),
	   tmp,pseudo_name,pseudo_from,mylocalhost (),pseudo_subject,
	   (unsigned long) now,mylocalhost (),stream->uid_validity,
	   stream->uid_last);
  for (s = hdr + strlen (hdr),i = 0; i < NUSERFLAGS; ++i)
    if (stream->user_flags[i])
      sprintf (s += strlen (s)," %s",stream->user_flags[i]);
  sprintf (s += strlen (s),"\nStatus: RO\n\n%s\n\n",pseudo_msg);
  return strlen (hdr);		/* return header length */
}

/* UNIX make status string
 * Accepts: MAIL stream
 *	    destination string to write
 *	    message cache entry
 *	    non-zero flag to write UID (.LT. 0 to write UID base info too)
 * Returns: length of string
 */

unsigned long unix_xstatus (MAILSTREAM *stream,char *status,MESSAGECACHE *elt,
			    long flag)
{
  char *t,stack[64];
  char *s = status;
  unsigned long n;
  int pad = 50;
  /* This used to use sprintf(), but thanks to certain cretinous C libraries
     with horribly slow implementations of sprintf() I had to change it to this
     mess.  At least it should be fast. */
				/* need to write X-IMAPbase: header? */
  if ((flag < 0) && !stream->uid_nosticky) {
    *s++ = 'X'; *s++ = '-'; *s++ = 'I'; *s++ = 'M'; *s++ = 'A'; *s++ = 'P';
    *s++ = 'b'; *s++ = 'a'; *s++ = 's'; *s++ = 'e'; *s++ = ':'; *s++ = ' ';
    t = stack;
    n = stream->uid_validity;	/* push UID validity digits on the stack */
    do *t++ = (char) (n % 10) + '0';
    while (n /= 10);
				/* pop UID validity digits from stack */
    while (t > stack) *s++ = *--t;
    *s++ = ' ';
    n = stream->uid_last;	/* push UID last digits on the stack */
    do *t++ = (char) (n % 10) + '0';
    while (n /= 10);
				/* pop UID last digits from stack */
    while (t > stack) *s++ = *--t;
    for (n = 0; n < NUSERFLAGS; ++n) if (t = stream->user_flags[n])
      for (*s++ = ' '; *t; *s++ = *t++);
    *s++ = '\n';
    pad += 30;			/* increased padding if have IMAPbase */
  }
  *s++ = 'S'; *s++ = 't'; *s++ = 'a'; *s++ = 't'; *s++ = 'u'; *s++ = 's';
  *s++ = ':'; *s++ = ' ';
  if (elt->seen) *s++ = 'R';
  *s++ = 'O'; *s++ = '\n';
  *s++ = 'X'; *s++ = '-'; *s++ = 'S'; *s++ = 't'; *s++ = 'a'; *s++ = 't';
  *s++ = 'u'; *s++ = 's'; *s++ = ':'; *s++ = ' ';
  if (elt->deleted) *s++ = 'D';
  if (elt->flagged) *s++ = 'F';
  if (elt->answered) *s++ = 'A';
  if (elt->draft) *s++ = 'T';
  *s++ = '\n';

  if (!stream->uid_nosticky) {	/* cretins with no life can't use this */
    *s++ = 'X'; *s++ = '-'; *s++ = 'K'; *s++ = 'e'; *s++ = 'y'; *s++ = 'w';
    *s++ = 'o'; *s++ = 'r'; *s++ = 'd'; *s++ = 's'; *s++ = ':';
    if (n = elt->user_flags) do {
      *s++ = ' ';
      for (t = stream->user_flags[find_rightmost_bit (&n)]; *t; *s++ = *t++);
    } while (n);
    n = s - status;		/* get size of stuff so far */
				/* pad X-Keywords to make size constant */
    if (n < pad) for (n = pad - n; n > 0; --n) *s++ = ' ';
    *s++ = '\n';
    if (flag) {			/* want to include UID? */
      t = stack;
      n = elt->private.uid;	/* push UID digits on the stack */
      do *t++ = (char) (n % 10) + '0';
      while (n /= 10);
      *s++ = 'X'; *s++ = '-'; *s++ = 'U'; *s++ = 'I'; *s++ = 'D'; *s++ = ':';
      *s++ = ' ';
				/* pop UID from stack */
      while (t > stack) *s++ = *--t;
      *s++ = '\n';
    }
  }
  *s++ = '\n'; *s = '\0';	/* end of extended message status */
  return s - status;		/* return size of resulting string */
}

/* Rewrite mailbox file
 * Accepts: MAIL stream, must be critical and locked
 *	    return pointer to number of expunged messages if want expunge
 *	    lock file name
 * Returns: T if success and mailbox unlocked, NIL if failure
 */

#define OVERFLOWBUFLEN 8192	/* initial overflow buffer length */

long unix_rewrite (MAILSTREAM *stream,unsigned long *nexp,DOTLOCK *lock)
{
  MESSAGECACHE *elt;
  UNIXFILE f;
  char *s;
  time_t tp[2];
  long ret,flag;
  unsigned long i,j;
  unsigned long recent = stream->recent;
  unsigned long size = LOCAL->pseudo ? unix_pseudo (stream,LOCAL->buf) : 0;
  if (nexp) *nexp = 0;		/* initially nothing expunged */
				/* calculate size of mailbox after rewrite */
  for (i = 1,flag = LOCAL->pseudo ? 1 : -1; i <= stream->nmsgs; i++)
    if (!(elt = mail_elt (stream,i))->deleted || !nexp) {
				/* add RFC822 size of this message */
      size += elt->private.special.text.size + elt->private.data +
	unix_xstatus (stream,LOCAL->buf,elt,flag) +
	  elt->private.msg.text.text.size + 1;
      flag = 1;			/* only count X-IMAPbase once */
    }
				/* extend the file as necessary */
  if (ret = unix_extend (stream,size)) {
    /* Set up buffered I/O file structure
     * curpos	current position being written through buffering
     * filepos	current position being written physically to the disk
     * bufpos	current position being written in the buffer
     * protect	current maximum position that can be written to the disk
     *		before buffering is forced
     * The code tries to buffer so that that disk is written in multiples of
     * OVERBLOWBUFLEN bytes.
     */
    f.stream = stream;		/* note mail stream */
    f.curpos = f.filepos = 0;	/* start of file */
    f.protect = stream->nmsgs ?	/* initial protection pointer */
    mail_elt (stream,1)->private.special.offset : 8192;
    f.bufpos = f.buf = (char *) fs_get (f.buflen = OVERFLOWBUFLEN);

    if (LOCAL->pseudo)		/* update pseudo-header */
      unix_write (&f,LOCAL->buf,unix_pseudo (stream,LOCAL->buf));
				/* loop through all messages */
    for (i = 1,flag = LOCAL->pseudo ? 1 : -1; i <= stream->nmsgs;) {
      elt = mail_elt (stream,i);/* get cache */
      if (nexp && elt->deleted){/* expunge this message? */
				/* one less recent message */
	if (elt->recent) --recent;
	mail_expunged(stream,i);/* notify upper levels */
	++*nexp;		/* count up one more expunged message */
      }
      else {			/* preserve this message */
	i++;			/* advance to next message */
	if ((flag < 0) ||	/* need to rewrite message? */
	    (elt->private.dirty || (f.curpos != elt->private.special.offset) ||
	     (elt->private.msg.header.text.size !=
	      (elt->private.data +
	       unix_xstatus (stream,LOCAL->buf,elt,flag))))) {
	  unsigned long newoffset = f.curpos;
				/* yes, seek to internal header */
	  lseek (LOCAL->fd,elt->private.special.offset,L_SET);
	  read (LOCAL->fd,LOCAL->buf,elt->private.special.text.size);
				/* see if need to squeeze out a CR */
	  if (LOCAL->buf[elt->private.special.text.size - 2] == '\r') {
	    LOCAL->buf[--elt->private.special.text.size - 1] = '\n';
	    --size;		/* squeezed out a CR from PC */
	  }
				/* protection pointer moves to RFC822 header */
	  f.protect = elt->private.special.offset +
	    elt->private.msg.header.offset;
				/* write internal header */
	  unix_write (&f,LOCAL->buf,elt->private.special.text.size);
				/* get RFC822 header */
	  s = unix_header (stream,elt->msgno,&j,FT_INTERNAL);
				/* in case this got decremented */
	  elt->private.msg.header.offset = elt->private.special.text.size;
				/* header size, sans trailing newline */
	  if ((j < 2) || (s[j - 2] == '\n')) j--;
	  if (j != elt->private.data) fatal ("header size inconsistent");
				/* protection pointer moves to RFC822 text */
	  f.protect = elt->private.special.offset +
	    elt->private.msg.text.offset;
	  unix_write (&f,s,j);	/* write RFC822 header */
				/* write status and UID */
	  unix_write (&f,LOCAL->buf,
		      j = unix_xstatus (stream,LOCAL->buf,elt,flag));
	  flag = 1;		/* only write X-IMAPbase once */
				/* new file header size */
	  elt->private.msg.header.text.size = elt->private.data + j;

				/* did text move? */
	  if (f.curpos != f.protect) {
				/* get message text */
	    s = unix_text_work (stream,elt,&j,FT_INTERNAL);
				/* this can happen if CRs were squeezed */
	    if (j < elt->private.msg.text.text.size) {
				/* so fix up counts */
	      size -= elt->private.msg.text.text.size - j;
	      elt->private.msg.text.text.size = j;
	    }
				/* can't happen it says here */
	    else if (j > elt->private.msg.text.text.size)
	      fatal ("text size inconsistent");
				/* new text offset, status/UID may change it */
	    elt->private.msg.text.offset = f.curpos - newoffset;
				/* protection pointer moves to next message */
	    f.protect = (i <= stream->nmsgs) ?
	      mail_elt (stream,i)->private.special.offset : (f.curpos + j + 1);
	    unix_write (&f,s,j);/* write text */
				/* write trailing newline */
	    unix_write (&f,"\n",1);
	  }
	  else {		/* tie off header and status */
	    unix_write (&f,NIL,NIL);
	    f.curpos = f.protect =/* restart everything at end of message */
	      f.filepos += elt->private.msg.text.text.size + 1;
	  }
				/* new internal header offset */
	  elt->private.special.offset = newoffset;
	  elt->private.dirty =NIL;/* message is now clean */
	}
	else {			/* no need to rewrite this message */
				/* tie off previous message if needed */
	  unix_write (&f,NIL,NIL);
	  f.curpos = f.protect =/* restart everything at end of message */
	    f.filepos += elt->private.special.text.size +
	      elt->private.msg.header.text.size +
		elt->private.msg.text.text.size + 1;
	}
      }
    }

    unix_write (&f,NIL,NIL);	/* tie off final message */
    if (size != f.filepos) fatal ("file size inconsistent");
    fs_give ((void **) &f.buf);	/* free buffer */
				/* make sure tied off */
    ftruncate (LOCAL->fd,LOCAL->filesize = size);
    fsync (LOCAL->fd);		/* make sure the updates take */
    if (size && (flag < 0)) fatal ("lost UID base information");
    LOCAL->dirty = NIL;		/* no longer dirty */
  				/* notify upper level of new mailbox sizes */
    mail_exists (stream,stream->nmsgs);
    mail_recent (stream,recent);
				/* set atime to now, mtime a second earlier */
    tp[1] = (tp[0] = time (0)) - 1;
				/* set the times, note change */
    if (!utime (stream->mailbox,tp)) LOCAL->filetime = tp[1];
    close (LOCAL->fd);		/* close and reopen file */
    if ((LOCAL->fd = open (stream->mailbox,O_RDWR,NIL)) < 0) {
      sprintf (LOCAL->buf,"Mailbox open failed, aborted: %s",strerror (errno));
      mm_log (LOCAL->buf,ERROR);
      unix_abort (stream);
    }
    dotlock_unlock (lock);	/* flush the lock file */
  }
  return ret;			/* return state from algorithm */
}

/* Extend UNIX mailbox file
 * Accepts: MAIL stream
 *	    new desired size
 * Return: T if success, else NIL
 */

long unix_extend (MAILSTREAM *stream,unsigned long size)
{
  unsigned long i = (size > LOCAL->filesize) ? size - LOCAL->filesize : 0;
  if (i) {			/* does the mailbox need to grow? */
    if (i > LOCAL->buflen) {	/* make sure have enough space */
				/* this user won the lottery all right */
      fs_give ((void **) &LOCAL->buf);
      LOCAL->buf = (char *) fs_get ((LOCAL->buflen = i) + 1);
    }
    memset (LOCAL->buf,'\0',i);	/* get a block of nulls */
    while (T) {			/* until write successful or punt */
      lseek (LOCAL->fd,LOCAL->filesize,L_SET);
      if ((write (LOCAL->fd,LOCAL->buf,i) >= 0) && !fsync (LOCAL->fd)) break;
      else {
	long e = errno;		/* note error before doing ftruncate */
	ftruncate (LOCAL->fd,LOCAL->filesize);
	if (mm_diskerror (stream,e,NIL)) {
	  fsync (LOCAL->fd);	/* user chose to punt */
	  sprintf (LOCAL->buf,"Unable to extend mailbox: %s",strerror (e));
	  mm_log (LOCAL->buf,ERROR);
	  return NIL;
	}
      }
    }
  }
  return LONGT;
}

/* Write data to buffered file
 * Accepts: buffered file pointer
 *	    file data or NIL to indicate "flush buffer"
 *	    date size (ignored for "flu