daemon: automatic public nodes discovering and bootstrap daemon switching

src/rpc/bootstrap_daemon.cpp

@@ -0,0 +1,95 @@
+#include "bootstrap_daemon.h"
+
+#include <stdexcept>
+
+#include "crypto/crypto.h"
+#include "cryptonote_core/cryptonote_core.h"
+#include "misc_log_ex.h"
+
+#undef MONERO_DEFAULT_LOG_CATEGORY
+#define MONERO_DEFAULT_LOG_CATEGORY "daemon.rpc.bootstrap_daemon"
+
+namespace cryptonote
+{
+
+  bootstrap_daemon::bootstrap_daemon(std::function<boost::optional<std::string>()> get_next_public_node) noexcept
+    : m_get_next_public_node(get_next_public_node)
+  {
+  }
+
+  bootstrap_daemon::bootstrap_daemon(const std::string &address, const boost::optional<epee::net_utils::http::login> &credentials)
+    : bootstrap_daemon(nullptr)
+  {
+    if (!set_server(address, credentials))
+    {
+      throw std::runtime_error("invalid bootstrap daemon address or credentials");
+    }
+  }
+
+  std::string bootstrap_daemon::address() const noexcept
+  {
+    const auto& host = m_http_client.get_host();
+    if (host.empty())
+    {
+      return std::string();
+    }
+    return host + ":" + m_http_client.get_port();
+  }
+
+  boost::optional<uint64_t> bootstrap_daemon::get_height()
+  {
+    cryptonote::COMMAND_RPC_GET_HEIGHT::request req;
+    cryptonote::COMMAND_RPC_GET_HEIGHT::response res;
+
+    if (!invoke_http_json("/getheight", req, res))
+    {
+      return boost::none;
+    }
+
+    if (res.status != CORE_RPC_STATUS_OK)
+    {
+      return boost::none;
+    }
+
+    return res.height;
+  }
+
+  bool bootstrap_daemon::handle_result(bool success)
+  {
+    if (!success && m_get_next_public_node)
+    {
+      m_http_client.disconnect();
+    }
+
+    return success;
+  }
+
+  bool bootstrap_daemon::set_server(const std::string &address, const boost::optional<epee::net_utils::http::login> &credentials /* = boost::none */)
+  {
+    if (!m_http_client.set_server(address, credentials))
+    {
+      MERROR("Failed to set bootstrap daemon address " << address);
+      return false;
+    }
+
+    MINFO("Changed bootstrap daemon address to " << address);
+    return true;
+  }
+
+
+  bool bootstrap_daemon::switch_server_if_needed()
+  {
+    if (!m_get_next_public_node || m_http_client.is_connected())
+    {
+      return true;
+    }
+
+    const boost::optional<std::string> address = m_get_next_public_node();
+    if (address) {
+      return set_server(*address);
+    }
+
+    return false;
+  }
+
+}