1 files changed, 36 insertions, 6 deletions
diff --git a/plugins/mod_httpserver.lua b/plugins/mod_httpserver.lua
index a8639281..f1f2150d 100644
--- a/plugins/mod_httpserver.lua
+++ b/plugins/mod_httpserver.lua
@@ -14,18 +14,48 @@ local t_concat = table.concat;
 
 local http_base = "www_files";
 
+local response_400 = { status = "400 Bad Request", body = "<h1>Bad Request</h1>Sorry, we didn't understand your request :(" };
 local response_404 = { status = "404 Not Found", body = "<h1>Page Not Found</h1>Sorry, we couldn't find what you were looking for :(" };
 
-local http_path = { http_base };
-local function handle_request(method, body, request)
-	local path = request.url.path:gsub("%.%.%/", ""):gsub("^/[^/]+", "");
-	http_path[2] = path;
-	local f, err = open(t_concat(http_path), "r");
+local function preprocess_path(path)
+	if path:sub(1,1) ~= "/" then
+		path = "/"..path;
+	end
+	local level = 0;
+	for component in path:gmatch("([^/]+)/") do
+		if component == ".." then
+			level = level - 1;
+		elseif component ~= "." then
+			level = level + 1;
+		end
+		if level < 0 then
+			return nil;
+		end
+	end
+	return path;
+end
+
+function serve_file(path)
+	local f, err = open(http_base..path, "r");
 	if not f then return response_404; end
 	local data = f:read("*a");
 	f:close();
 	return data;
 end
 
+local function handle_file_request(method, body, request)
+	local path = preprocess_path(request.url.path);
+	if not path then return response_400; end
+	path = path:gsub("^/[^/]+", ""); -- Strip /files/
+	return serve_file(path);
+end
+
+local function handle_default_request(method, body, request)
+	local path = preprocess_path(request.url.path);
+	if not path then return response_400; end
+	return serve_file(path);
+end
+
 local ports = config.get(module.host, "core", "http_ports") or { 5280 };
-httpserver.new_from_config(ports, "files", handle_request);
+httpserver.set_default_handler(handle_default_request);
+httpserver.new_from_config(ports, "files", handle_file_request);