--- libaitwww/src/tools.c	2012/08/01 00:40:41	1.3
+++ libaitwww/src/tools.c	2012/09/20 14:19:45	1.4
@@ -3,7 +3,7 @@
 *  by Michael Pounov <misho@elwix.org>
 *
 * $Author: misho $
-* $Id: tools.c,v 1.3 2012/08/01 00:40:41 misho Exp $
+* $Id: tools.c,v 1.4 2012/09/20 14:19:45 misho Exp $
 *
 **************************************************************************
 The ELWIX and AITNET software is distributed under the following
@@ -177,4 +177,81 @@ www_unescape(char * __restrict str)
 	}
 
 	str[i] = 0;
+}
+
+/*
+ * www_undot() - Undotted and clean WWW query filename
+ *
+ * @pname = query filename
+ * return: =NULL error or !=NULL allocated valid filename, after use you must call io_freeVar()
+ */
+ait_val_t *
+www_undot(const char * __restrict pname)
+{
+	char *s, *s2, *fname;
+	int l;
+	ait_val_t *v;
+
+	if (!pname)
+		return NULL;
+	/* check for valid query filename */
+	if (*pname != '/')
+		return NULL;
+
+	v = io_allocVar();
+	if (!v) {
+		www_SetErr(io_GetErrno(), "%s", io_GetError());
+		return NULL;
+	} else {
+		AIT_SET_STR(v, pname + 1);
+		fname = AIT_GET_STR(v);
+	}
+
+	/* collapse / sequences */
+	if ((s = strstr(fname, "//"))) {
+		s2 = s + 1;
+		for (s2 = ++s; *s2 == '/'; s2++);
+		memmove(s, s2, strlen(s2) + 1);
+	}
+
+	/* escaped ./ and /./ sequences */
+	while (!strncmp(fname, "./", 2))
+		memmove(fname, fname + 2, strlen(fname + 1));
+	while ((s = strstr(fname, "/./")))
+		memmove(s, s + 2, strlen(s + 1));
+
+	/* alternate between removing leading ../ and removing xxx/../ */
+	while (42) {
+		while (!strncmp(fname, "../", 3))
+			memmove(fname, fname + 3, strlen(fname + 2));
+		if (!(s = strstr(fname, "/../")))
+			break;
+		for (s2 = s - 1; s2 >= fname && *s2 != '/'; --s2);
+		memmove(s2 + 1, s + 4, strlen(s + 3));
+	}
+
+	/* elide any /.. at the end */
+	while ((l = strlen(fname)) > 3 && 
+			!strcmp((s = fname + l - 3), "/..")) {
+		for (s2 = s - 1; s2 >= fname && *s2 != '/'; --s2);
+		if (s2 < fname)
+			break;
+		*s2 = 0;
+	}
+
+	/* if filename is empry add current dir */
+	if (!*fname) {
+		AIT_FREE_VAL(v);
+		AIT_SET_STR(v, "./");
+		fname = AIT_GET_STR(v);
+	}
+
+	/* check for valid filename */
+	if (*fname == '/' || (fname[0] == '.' && fname[1] == '.' && 
+				(!fname[2] || fname[2] == '/'))) {
+		io_freeVar(&v);
+		return NULL;
+	}
+
+	return v;
 }