Add a new cnse.fetchscript, which first checks for an absolute path,

then looks in the scripts subdirectory, then in the current directory.
cnse.fetchfile_absolute now checks for an absolute path, then calls
nmap_fetchfile if that fails (and no longer looks in scripts/). Use
cnse.fetchscript when accessing files that should be in the scripts
subdirectory.

nse_fs.cc

@@ -50,19 +50,35 @@ static bool filename_is_absolute(const char *file) {
   return false;
 }
 
-static int nse_fetchfile(char *path, size_t path_len, const char *file) {
+/* This is a modification of nmap_fetchfile specialized to look for files
-  int type = nmap_fetchfile(path, path_len, file);
+ * in the scripts subdirectory. If the path is absolute, it is always tried
+ * verbatim. Otherwise, the file is looked for under scripts/, and then finally
+ * in the current directory.
+ */
+static int nse_fetchscript(char *path, size_t path_len, const char *file) {
+  std::string scripts_path = std::string(SCRIPT_ENGINE_LUA_DIR) + std::string(file);
+  int type;
+
+  if (filename_is_absolute(file)) {
+    if (o.debugging > 1)
+      log_write(LOG_STDOUT, "%s: Trying absolute path %s\n", SCRIPT_ENGINE, file);
+    Strncpy(path, file, path_len);
+    return nmap_fileexistsandisreadable(file);
+  }
+
+  // lets look in <path>/scripts
+  type = nmap_fetchfile(path, path_len, scripts_path.c_str());
 
-  // lets look in <nmap>/scripts too
   if (type == 0) {
-    std::string alt_path = std::string(SCRIPT_ENGINE_LUA_DIR) + std::string(file);
+    // current directory
-    type = nmap_fetchfile(path, path_len, alt_path.c_str());
+    Strncpy(path, file, path_len);
+    return nmap_fileexistsandisreadable(file);
   }
 
   return type;
 }
 
-/* This is a modification of nse_fetchfile that first looks for an
+/* This is a modification of nmap_fetchfile that first looks for an
  * absolute file name.
  */
 static int nse_fetchfile_absolute(char *path, size_t path_len, const char *file) {
@@ -73,13 +89,13 @@ static int nse_fetchfile_absolute(char *path, size_t path_len, const char *file)
     return nmap_fileexistsandisreadable(file);
   }
 
-  return nse_fetchfile(path, path_len, file);
+  return nmap_fetchfile(path, path_len, file);
 }
 
-int fetchfile_absolute (lua_State *L)
+static int nse_fetch (lua_State *L, int (*fetch)(char *, size_t, const char *))
 {
   char path[MAXPATHLEN];
-  switch (nse_fetchfile_absolute(path, sizeof(path), luaL_checkstring(L, 1)))
+  switch (fetch(path, sizeof(path), luaL_checkstring(L, 1)))
   {
     case 0: // no such path
       lua_pushnil(L);
@@ -94,11 +110,21 @@ int fetchfile_absolute (lua_State *L)
       lua_pushstring(L, path);
       break;
     default:
-      return luaL_error(L, "nse_fetchfile_absolute returned bad code");
+      return luaL_error(L, "nse_fetch returned bad code");
   }
   return 2;
 }
 
+int fetchscript (lua_State *L)
+{
+  return nse_fetch(L, nse_fetchscript);
+}
+
+int fetchfile_absolute (lua_State *L)
+{
+  return nse_fetch(L, nse_fetchfile_absolute);
+}
+
 
 /* LuaFileSystem directory iterator port.
  * 

nse_fs.h

@@ -1,6 +1,8 @@
 #ifndef NSE_FS
 #define NSE_FS
 
+int fetchscript (lua_State *L);
+
 int fetchfile_absolute (lua_State *L);
 
 int nse_readdir (lua_State *L);

nse_main.cc

@@ -257,6 +257,7 @@ static void open_cnse (lua_State *L)
 {
   static const luaL_Reg nse[] = {
     {"fetchfile_absolute", fetchfile_absolute},
+    {"fetchscript", fetchscript},
     {"dir", nse_readdir},
     {"nsock_loop", nsock_loop},
     {"key_was_pressed", key_was_pressed},

nse_main.lua

@@ -540,7 +540,7 @@ local function get_chosen_scripts (rules)
     for globalized_rule, rule_table in pairs(entry_rules) do
       if setfenv(rule_table.compiled_rule, env)() then -- run the compiled rule
         used_rules[rule_table.original_rule] = true;
-        local t, path = cnse.fetchfile_absolute(filename);
+        local t, path = cnse.fetchscript(filename);
         if t == "file" then
           if not files_loaded[path] then
             script = Script.new(path);
@@ -568,9 +568,9 @@ local function get_chosen_scripts (rules)
   -- Now load any scripts listed by name rather than by category.
   for rule, loaded in pairs(used_rules) do
     if not loaded then -- attempt to load the file/directory
-      local t, path = cnse.fetchfile_absolute(rule);
+      local t, path = cnse.fetchscript(rule);
       if t == nil then -- perhaps omitted the extension?
-        t, path = cnse.fetchfile_absolute(rule..".nse");
+        t, path = cnse.fetchscript(rule..".nse");
       end
       if t == nil then
         error("'"..rule.."' did not match a category, filename, or directory");