dns: add c-ares based unittests

src/net/dns_message_test.cpp

@@ -6,15 +6,36 @@
 
 #include <gmock/gmock.h>
 
+#include "core/span.hpp"
 #include "net/dns_message_request.hpp"
 #include "net/dns_message_response_parser.hpp"
 #include "net/iobuf.hpp"
 
 #include "test_util.hpp"
 
+#ifdef HAVE_C_ARES
+#include <ares.h>
+#include <set>
+#endif
+
 using namespace net;
 using namespace net::dns_message;
 
+#ifdef HAVE_C_ARES
+static span<const uint8_t> CreateRequery(const char* name, int dnsclass, int type) {
+  uint8_t* buf = nullptr;
+  int buflen = 0;
+  EXPECT_EQ(ARES_SUCCESS, ares_create_query(name, dnsclass, type, 0, 0x1, &buf, &buflen, 0));
+  if (buflen == 0) {
+    return {};
+  }
+  static uint8_t poolbuf[1500];
+  memcpy(poolbuf, buf, buflen);
+  ares_free_string(buf);
+  return span<const uint8_t>(poolbuf, static_cast<size_t>(buflen));
+}
+#endif
+
 TEST(DnsMessageTest, Request) {
   request msg;
   ASSERT_TRUE(msg.init("www.google.com", DNS_TYPE_AAAA));
@@ -23,6 +44,25 @@ TEST(DnsMessageTest, Request) {
   ASSERT_FALSE(msg.init("www.google-long-long-long-long-long-long-long-long-long-long-long-long.com", DNS_TYPE_AAAA));
 }
 
+#ifdef HAVE_C_ARES
+TEST(DnsMessageTest, RequestCAresMatch) {
+  request msg;
+  ASSERT_TRUE(msg.init("www.google.com", DNS_TYPE_AAAA));
+
+  auto source = IOBuf::create(SOCKET_BUF_SIZE);
+
+  for (auto buffer : msg.buffers()) {
+    source->reserve(0, buffer.size());
+    memcpy(source->mutable_tail(), buffer.data(), buffer.size());
+    source->append(buffer.size());
+  }
+
+  auto target = CreateRequery("www.google.com", DNS_CLASS_IN, DNS_TYPE_AAAA);
+
+  ASSERT_EQ(::testing::Bytes(*source), ::testing::Bytes(target));
+}
+#endif
+
 static constexpr const uint8_t kExpectedRequestBytes[] = {
     0x00, 0x00, 0x01, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x77, 0x77, 0x77,
     0x05, 0x62, 0x61, 0x69, 0x64, 0x75, 0x03, 0x63, 0x6f, 0x6d, 0x00, 0x00, 0x01, 0x00, 0x01};
@@ -70,3 +110,43 @@ TEST(DnsMessageTest, AAndCnameResponseBytes) {
   };
   ASSERT_EQ(expected_cname, response.cname());
 }
+
+#ifdef HAVE_C_ARES
+TEST(DnsMessageTest, AAndCnameResponseBytesCAresMatch) {
+  struct hostent* host = nullptr;
+  struct ares_addrttl info[2] = {};
+  int count = std::size(info);
+  ASSERT_EQ(ARES_SUCCESS, ares_parse_a_reply(kResponseBytes, std::size(kResponseBytes), &host, info, &count));
+  ASSERT_EQ(2, count);
+  ASSERT_EQ(25, info[0].ttl);
+  ASSERT_EQ(25, info[1].ttl);
+
+  std::set<asio::ip::address_v4> info_addr;
+  for (int i = 0; i < count; ++i) {
+    info_addr.emplace(ntohl(info[i].ipaddr.s_addr));
+  }
+  std::set<asio::ip::address_v4> expected_addr{asio::ip::make_address("103.235.47.103").to_v4(),
+                                               asio::ip::make_address("103.235.46.40").to_v4()};
+  ASSERT_EQ(expected_addr, info_addr);
+
+  ASSERT_NE(nullptr, host);
+  ASSERT_EQ(AF_INET, host->h_addrtype);
+  std::set<std::string> cname;
+  cname.insert(host->h_name);
+  for (int i = 0; host->h_aliases[i]; ++i) {
+    cname.insert(host->h_aliases[i]);
+  }
+  std::set<std::string> expected_cname{
+      "www.baidu.com",
+      "www.a.shifen.com",
+  };
+  ASSERT_EQ(expected_cname, cname);
+
+  std::set<asio::ip::address_v4> host_addr;
+  for (int i = 0; host->h_addr_list[i]; ++i) {
+    host_addr.emplace(ntohl(((struct in_addr*)(host->h_addr_list[i]))->s_addr));
+  }
+  ASSERT_EQ(expected_addr, host_addr);
+  ares_free_hostent(host);
+}
+#endif