Add new method to set nsid on namespaces

Signed-off-by: francescomessina <francescomessina92@hotmail.com>

Author: francescomessina

src/polycubed/src/utils/ns.cpp

@@ -202,6 +202,21 @@ void Namespace::set_id(int id) {
   throw std::runtime_error("Error constructing nlmsg");
 }
 
+int Namespace::set_random_id() {
+  int id = 0;
+again:
+  id++;
+  try {
+    set_id(id);
+  } catch (...) {
+    if (id < 100)
+      goto again;
+    else
+      throw std::runtime_error("set_random_id failed");
+  }
+  return id;
+}
+
 std::string Namespace::get_name() const {
   return name_;
 }

src/polycubed/src/utils/ns.h

@@ -34,6 +34,7 @@ class Namespace {
   void execute(std::function<void()> f);
   void remove();
   void set_id(int id);
+  int set_random_id();
 
   std::string get_name() const;
   int get_fd() const;