EventService : Support async_resolve for subscribers
The http client at bmcweb does not resolve the client's
hostname asynchronously
This commit implements the async_resolve by using systemd resolved.
The async dbus message to resolvd.service is sent when a subscriber
successfully subscribes for events. The method ResolveHostname is
used to resolve the subscriber's hostname
Tested by:
Subscribe for the events at BMC using DMTF event listener
Generate an event and see the same is received at the listener's console
Signed-off-by: Sunitha Harish <sunithaharish04@gmail.com>
Change-Id: I3ab8206ac4764cfa025e94c06407524d6ba220e0
diff --git a/include/async_resolve.hpp b/include/async_resolve.hpp
new file mode 100644
index 0000000..306a499
--- /dev/null
+++ b/include/async_resolve.hpp
@@ -0,0 +1,99 @@
+#pragma once
+#include <boost/asio/ip/address.hpp>
+#include <boost/asio/ip/basic_endpoint.hpp>
+#include <sdbusplus/message.hpp>
+
+#include <charconv>
+#include <iostream>
+#include <memory>
+
+namespace crow
+{
+
+namespace async_resolve
+{
+
+class Resolver
+{
+ public:
+ Resolver() = default;
+
+ ~Resolver() = default;
+
+ template <typename ResolveHandler>
+ void asyncResolve(const std::string& host, const std::string& port,
+ ResolveHandler&& handler)
+ {
+ BMCWEB_LOG_DEBUG << "Trying to resolve: " << host << ":" << port;
+ uint64_t flag = 0;
+ crow::connections::systemBus->async_method_call(
+ [host, port, handler{std::move(handler)}](
+ const boost::system::error_code ec,
+ const std::vector<
+ std::tuple<int32_t, int32_t, std::vector<uint8_t>>>& resp,
+ const std::string& hostName, const uint64_t flagNum) {
+ std::vector<boost::asio::ip::tcp::endpoint> endpointList;
+ if (ec)
+ {
+ BMCWEB_LOG_ERROR << "Resolve failed: " << ec.message();
+ handler(ec, endpointList);
+ return;
+ }
+ BMCWEB_LOG_DEBUG << "ResolveHostname returned: " << hostName
+ << ":" << flagNum;
+ // Extract the IP address from the response
+ for (auto resolveList : resp)
+ {
+ std::vector<uint8_t> ipAddress = std::get<2>(resolveList);
+ boost::asio::ip::tcp::endpoint endpoint;
+ if (ipAddress.size() == 4) // ipv4 address
+ {
+ BMCWEB_LOG_DEBUG << "ipv4 address";
+ boost::asio::ip::address_v4 ipv4Addr(
+ {ipAddress[0], ipAddress[1], ipAddress[2],
+ ipAddress[3]});
+ endpoint.address(ipv4Addr);
+ }
+ else if (ipAddress.size() == 16) // ipv6 address
+ {
+ BMCWEB_LOG_DEBUG << "ipv6 address";
+ boost::asio::ip::address_v6 ipv6Addr(
+ {ipAddress[0], ipAddress[1], ipAddress[2],
+ ipAddress[3], ipAddress[4], ipAddress[5],
+ ipAddress[6], ipAddress[7], ipAddress[8],
+ ipAddress[9], ipAddress[10], ipAddress[11],
+ ipAddress[12], ipAddress[13], ipAddress[14],
+ ipAddress[15]});
+ endpoint.address(ipv6Addr);
+ }
+ else
+ {
+ BMCWEB_LOG_ERROR
+ << "Resolve failed to fetch the IP address";
+ handler(ec, endpointList);
+ return;
+ }
+ uint16_t portNum;
+ auto it = std::from_chars(
+ port.data(), port.data() + port.size(), portNum);
+ if (it.ec != std::errc())
+ {
+ BMCWEB_LOG_ERROR << "Failed to get the Port";
+ handler(ec, endpointList);
+ return;
+ }
+ endpoint.port(portNum);
+ BMCWEB_LOG_DEBUG << "resolved endpoint is : " << endpoint;
+ endpointList.push_back(endpoint);
+ }
+ // All the resolved data is filled in the endpointList
+ handler(ec, endpointList);
+ },
+ "org.freedesktop.resolve1", "/org/freedesktop/resolve1",
+ "org.freedesktop.resolve1.Manager", "ResolveHostname", 0, host,
+ AF_UNSPEC, flag);
+ }
+};
+
+} // namespace async_resolve
+} // namespace crow