1 files changed, 122 insertions, 0 deletions
diff --git a/src/network/resolver.hpp b/src/network/resolver.hpp
new file mode 100644
index 0000000..f65ff86
--- /dev/null
+++ b/src/network/resolver.hpp
@@ -0,0 +1,122 @@
+#pragma once
+
+#include "biboumi.h"
+
+#include <functional>
+#include <vector>
+#include <memory>
+#include <string>
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+#ifdef UDNS_FOUND
+# include <udns.h>
+#endif
+
+class AddrinfoDeleter
+{
+ public:
+  void operator()(struct addrinfo* addr)
+  {
+    freeaddrinfo(addr);
+  }
+};
+
+
+class Resolver
+{
+public:
+
+  using ErrorCallbackType = std::function<void(const char*)>;
+  using SuccessCallbackType = std::function<void(const struct addrinfo*)>;
+
+  Resolver();
+  ~Resolver() = default;
+  Resolver(const Resolver&) = delete;
+  Resolver(Resolver&&) = delete;
+  Resolver& operator=(const Resolver&) = delete;
+  Resolver& operator=(Resolver&&) = delete;
+
+  bool is_resolving() const
+  {
+#ifdef UDNS_FOUND
+    return this->resolving;
+#else
+    return false;
+#endif
+  }
+
+  bool is_resolved() const
+  {
+    return this->resolved;
+  }
+
+  const auto& get_result() const
+  {
+    return this->addr;
+  }
+  std::string get_error_message() const
+  {
+    return this->error_msg;
+  }
+
+  void clear()
+  {
+#ifdef UDNS_FOUND
+    this->resolved6 = false;
+    this->resolved4 = false;
+    this->resolving = false;
+    this->port.clear();
+#endif
+    this->resolved = false;
+    this->addr.reset();
+    this->error_msg.clear();
+  }
+
+  void resolve(const std::string& hostname, const std::string& port,
+               SuccessCallbackType success_cb, ErrorCallbackType error_cb);
+
+private:
+  void start_resolving(const std::string& hostname, const std::string& port);
+  std::vector<std::string> look_in_etc_hosts(const std::string& hostname);
+  /**
+   * Call getaddrinfo() on the given hostname or IP, and append the result
+   * to our internal addrinfo list. Return getaddrinfo()’s return value.
+   */
+  int call_getaddrinfo(const char* name, const char* port, int flags);
+
+#ifdef UDNS_FOUND
+  void on_hostname4_resolved(dns_rr_a4 *result);
+  void on_hostname6_resolved(dns_rr_a6 *result);
+  /**
+   * Called after one record (4 or 6) has been resolved.
+   */
+  void after_resolved();
+
+  void start_timer();
+
+  void on_resolved();
+
+  bool resolved4;
+  bool resolved6;
+
+  bool resolving;
+
+  std::string port;
+
+#endif
+ /**
+  * Tells if we finished the resolution process. It doesn't indicate if it
+  * was successful (it is true even if the result is an error).
+  */
+  bool resolved;
+  std::string error_msg;
+
+  std::unique_ptr<struct addrinfo, AddrinfoDeleter> addr;
+
+  ErrorCallbackType error_cb;
+  SuccessCallbackType success_cb;
+};
+
+std::string addr_to_string(const struct addrinfo* rp);