lib: provide simple resource validation callback

Previously only JobResource had a method called Validate() to check the
resource for completeness and correctness.
This patch adds a virtual Validate() method to BareosResource that can
be overridden by every resource that needs to do additional checks.

core/src/dird/dird_conf.cc

@@ -1260,8 +1260,8 @@ bool ValidateResource(int res_type, ResourceItem* items, BareosResource* res)
      * a jobdef don't have to be fully defined.
      */
     return true;
-  } else if (res_type == R_JOB) {
-    if (!((JobResource*)res)->Validate()) { return false; }
+  } else if (!res->Validate()) {
+    return false;
   }
 
   for (int i = 0; items[i].name; i++) {

core/src/dird/dird_conf.h

@@ -535,7 +535,7 @@ class JobResource : public BareosResource {
   runtime_job_status_t* rjs = nullptr; /**< Runtime Job Status */
 
   /* Methods */
-  bool Validate();
+  virtual bool Validate() override;
 };
 /* clang-format on */
 

core/src/lib/bareos_resource.cc

@@ -48,6 +48,10 @@ BareosResource::BareosResource(const BareosResource& other)
   ::memcpy(inherit_content_, other.inherit_content_, MAX_RES_ITEMS);
 }
 
+bool BareosResource::Validate() {
+  return true;
+}
+
 BareosResource& BareosResource::operator=(const BareosResource& rhs)
 {
   next_ = rhs.next_;

core/src/lib/bareos_resource.h

@@ -52,6 +52,8 @@ class BareosResource {
                            const ConfigurationParser& my_config,
                            bool hide_sensitive_data = false,
                            bool verbose = false);
+
+  virtual bool Validate();
 };
 
 #endif /* BAREOS_LIB_BAREOS_RESOURCE_H_ */