AsyncResolve cleanups and error handling

The Async DBus resolver really has nothing to do with crow, which is our
core http library namespace and has some opportunistic cleanups that can
be done.

This commit moves it into the bmcweb namespace (unimportantly) and
breaks out one of the larger functions such that it can be unit tested,
and unit tests it.

Tested: Unit tests pass.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: Ie3cfbb0ef81a027a1ad42358c04967a517471117

1 files changed, 33 insertions, 30 deletions

diff --git a/include/async_resolve.hpp b/include/async_resolve.hpp
index 5e526cabc5..2bf511299d 100644
--- a/include/async_resolve.hpp
+++ b/include/async_resolve.hpp
@@ -12,11 +12,36 @@
 #include <iostream>
 #include <memory>
 
-namespace crow
+namespace async_resolve
 {
 
-namespace async_resolve
+inline bool endpointFromResolveTuple(const std::vector<uint8_t>& ipAddress,
+                                     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";
+        return false;
+    }
+    return true;
+}
 
 class Resolver
 {
@@ -75,36 +100,15 @@ class Resolver
             for (const std::tuple<int32_t, int32_t, std::vector<uint8_t>>&
                      resolveList : resp)
             {
-                const 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
+                endpoint.port(portNum);
+                if (!endpointFromResolveTuple(std::get<2>(resolveList),
+                                              endpoint))
                 {
-                    BMCWEB_LOG_ERROR
-                        << "Resolve failed to fetch the IP address";
-                    handler(ec, endpointList);
-                    return;
+                    boost::system::error_code ecErr = make_error_code(
+                        boost::system::errc::address_not_available);
+                    handler(ecErr, endpointList);
                 }
-                endpoint.port(portNum);
                 BMCWEB_LOG_DEBUG << "resolved endpoint is : " << endpoint;
                 endpointList.push_back(endpoint);
             }
@@ -118,5 +122,4 @@ class Resolver
 };
 
 } // namespace async_resolve
-} // namespace crow
 #endif