[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit

Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/app/c-ares/src/test/ares-test-mock.cc b/ap/app/c-ares/src/test/ares-test-mock.cc
new file mode 100644
index 0000000..2cbe6b4
--- /dev/null
+++ b/ap/app/c-ares/src/test/ares-test-mock.cc
@@ -0,0 +1,1161 @@
+#include "ares-test.h"
+#include "dns-proto.h"
+
+#include <sstream>
+#include <vector>
+
+using testing::InvokeWithoutArgs;
+using testing::DoAll;
+
+namespace ares {
+namespace test {
+
+TEST_P(MockChannelTest, Basic) {
+  std::vector<byte> reply = {
+    0x00, 0x00,  // qid
+    0x84, // response + query + AA + not-TC + not-RD
+    0x00, // not-RA + not-Z + not-AD + not-CD + rc=NoError
+    0x00, 0x01,  // 1 question
+    0x00, 0x01,  // 1 answer RRs
+    0x00, 0x00,  // 0 authority RRs
+    0x00, 0x00,  // 0 additional RRs
+    // Question
+    0x03, 'w', 'w', 'w',
+    0x06, 'g', 'o', 'o', 'g', 'l', 'e',
+    0x03, 'c', 'o', 'm',
+    0x00,
+    0x00, 0x01,  // type A
+    0x00, 0x01,  // class IN
+    // Answer
+    0x03, 'w', 'w', 'w',
+    0x06, 'g', 'o', 'o', 'g', 'l', 'e',
+    0x03, 'c', 'o', 'm',
+    0x00,
+    0x00, 0x01,  // type A
+    0x00, 0x01,  // class IN
+    0x00, 0x00, 0x01, 0x00,  // TTL
+    0x00, 0x04,  // rdata length
+    0x01, 0x02, 0x03, 0x04
+  };
+
+  ON_CALL(server_, OnRequest("www.google.com", ns_t_a))
+    .WillByDefault(SetReplyData(&server_, reply));
+
+  HostResult result;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  std::stringstream ss;
+  ss << result.host_;
+  EXPECT_EQ("{'www.google.com' aliases=[] addrs=[1.2.3.4]}", ss.str());
+}
+
+// UDP only so mock server doesn't get confused by concatenated requests
+TEST_P(MockUDPChannelTest, ParallelLookups) {
+  DNSPacket rsp1;
+  rsp1.set_response().set_aa()
+    .add_question(new DNSQuestion("www.google.com", ns_t_a))
+    .add_answer(new DNSARR("www.google.com", 100, {2, 3, 4, 5}));
+  ON_CALL(server_, OnRequest("www.google.com", ns_t_a))
+    .WillByDefault(SetReply(&server_, &rsp1));
+  DNSPacket rsp2;
+  rsp2.set_response().set_aa()
+    .add_question(new DNSQuestion("www.example.com", ns_t_a))
+    .add_answer(new DNSARR("www.example.com", 100, {1, 2, 3, 4}));
+  ON_CALL(server_, OnRequest("www.example.com", ns_t_a))
+    .WillByDefault(SetReply(&server_, &rsp2));
+
+  HostResult result1;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result1);
+  HostResult result2;
+  ares_gethostbyname(channel_, "www.example.com.", AF_INET, HostCallback, &result2);
+  HostResult result3;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result3);
+  Process();
+  EXPECT_TRUE(result1.done_);
+  EXPECT_TRUE(result2.done_);
+  EXPECT_TRUE(result3.done_);
+  std::stringstream ss1;
+  ss1 << result1.host_;
+  EXPECT_EQ("{'www.google.com' aliases=[] addrs=[2.3.4.5]}", ss1.str());
+  std::stringstream ss2;
+  ss2 << result2.host_;
+  EXPECT_EQ("{'www.example.com' aliases=[] addrs=[1.2.3.4]}", ss2.str());
+  std::stringstream ss3;
+  ss3 << result3.host_;
+  EXPECT_EQ("{'www.google.com' aliases=[] addrs=[2.3.4.5]}", ss3.str());
+}
+
+// UDP to TCP specific test
+TEST_P(MockUDPChannelTest, TruncationRetry) {
+  DNSPacket rsptruncated;
+  rsptruncated.set_response().set_aa().set_tc()
+    .add_question(new DNSQuestion("www.google.com", ns_t_a));
+  DNSPacket rspok;
+  rspok.set_response()
+    .add_question(new DNSQuestion("www.google.com", ns_t_a))
+    .add_answer(new DNSARR("www.google.com", 100, {1, 2, 3, 4}));
+  EXPECT_CALL(server_, OnRequest("www.google.com", ns_t_a))
+    .WillOnce(SetReply(&server_, &rsptruncated))
+    .WillOnce(SetReply(&server_, &rspok));
+  HostResult result;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  std::stringstream ss;
+  ss << result.host_;
+  EXPECT_EQ("{'www.google.com' aliases=[] addrs=[1.2.3.4]}", ss.str());
+}
+
+static int sock_cb_count = 0;
+static int SocketConnectCallback(ares_socket_t fd, int type, void *data) {
+  int rc = *(int*)data;
+  if (verbose) std::cerr << "SocketConnectCallback(" << fd << ") invoked" << std::endl;
+  sock_cb_count++;
+  return rc;
+}
+
+TEST_P(MockChannelTest, SockCallback) {
+  DNSPacket rsp;
+  rsp.set_response().set_aa()
+    .add_question(new DNSQuestion("www.google.com", ns_t_a))
+    .add_answer(new DNSARR("www.google.com", 100, {2, 3, 4, 5}));
+  EXPECT_CALL(server_, OnRequest("www.google.com", ns_t_a))
+    .WillOnce(SetReply(&server_, &rsp));
+
+  // Get notified of new sockets
+  int rc = ARES_SUCCESS;
+  ares_set_socket_callback(channel_, SocketConnectCallback, &rc);
+
+  HostResult result;
+  sock_cb_count = 0;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_EQ(1, sock_cb_count);
+  EXPECT_TRUE(result.done_);
+  std::stringstream ss;
+  ss << result.host_;
+  EXPECT_EQ("{'www.google.com' aliases=[] addrs=[2.3.4.5]}", ss.str());
+}
+
+TEST_P(MockChannelTest, SockFailCallback) {
+  // Notification of new sockets gives an error.
+  int rc = -1;
+  ares_set_socket_callback(channel_, SocketConnectCallback, &rc);
+
+  HostResult result;
+  sock_cb_count = 0;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_LT(1, sock_cb_count);
+  EXPECT_TRUE(result.done_);
+  EXPECT_EQ(ARES_ECONNREFUSED, result.status_);
+}
+
+static int sock_config_cb_count = 0;
+static int SocketConfigureCallback(ares_socket_t fd, int type, void *data) {
+  int rc = *(int*)data;
+  if (verbose) std::cerr << "SocketConfigureCallback(" << fd << ") invoked" << std::endl;
+  sock_config_cb_count++;
+  return rc;
+}
+
+TEST_P(MockChannelTest, SockConfigureCallback) {
+  DNSPacket rsp;
+  rsp.set_response().set_aa()
+    .add_question(new DNSQuestion("www.google.com", ns_t_a))
+    .add_answer(new DNSARR("www.google.com", 100, {2, 3, 4, 5}));
+  EXPECT_CALL(server_, OnRequest("www.google.com", ns_t_a))
+    .WillOnce(SetReply(&server_, &rsp));
+
+  // Get notified of new sockets
+  int rc = ARES_SUCCESS;
+  ares_set_socket_configure_callback(channel_, SocketConfigureCallback, &rc);
+
+  HostResult result;
+  sock_config_cb_count = 0;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_EQ(1, sock_config_cb_count);
+  EXPECT_TRUE(result.done_);
+  std::stringstream ss;
+  ss << result.host_;
+  EXPECT_EQ("{'www.google.com' aliases=[] addrs=[2.3.4.5]}", ss.str());
+}
+
+TEST_P(MockChannelTest, SockConfigureFailCallback) {
+  // Notification of new sockets gives an error.
+  int rc = -1;
+  ares_set_socket_configure_callback(channel_, SocketConfigureCallback, &rc);
+
+  HostResult result;
+  sock_config_cb_count = 0;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_LT(1, sock_config_cb_count);
+  EXPECT_TRUE(result.done_);
+  EXPECT_EQ(ARES_ECONNREFUSED, result.status_);
+}
+
+// TCP only to prevent retries
+TEST_P(MockTCPChannelTest, MalformedResponse) {
+  std::vector<byte> one = {0x01};
+  EXPECT_CALL(server_, OnRequest("www.google.com", ns_t_a))
+    .WillOnce(SetReplyData(&server_, one));
+
+  HostResult result;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  EXPECT_EQ(ARES_ETIMEOUT, result.status_);
+}
+
+TEST_P(MockTCPChannelTest, FormErrResponse) {
+  DNSPacket rsp;
+  rsp.set_response().set_aa()
+    .add_question(new DNSQuestion("www.google.com", ns_t_a));
+  rsp.set_rcode(ns_r_formerr);
+  EXPECT_CALL(server_, OnRequest("www.google.com", ns_t_a))
+    .WillOnce(SetReply(&server_, &rsp));
+  HostResult result;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  EXPECT_EQ(ARES_EFORMERR, result.status_);
+}
+
+TEST_P(MockTCPChannelTest, ServFailResponse) {
+  DNSPacket rsp;
+  rsp.set_response().set_aa()
+    .add_question(new DNSQuestion("www.google.com", ns_t_a));
+  rsp.set_rcode(ns_r_servfail);
+  EXPECT_CALL(server_, OnRequest("www.google.com", ns_t_a))
+    .WillOnce(SetReply(&server_, &rsp));
+  HostResult result;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  // ARES_FLAG_NOCHECKRESP not set, so SERVFAIL consumed
+  EXPECT_EQ(ARES_ECONNREFUSED, result.status_);
+}
+
+TEST_P(MockTCPChannelTest, NotImplResponse) {
+  DNSPacket rsp;
+  rsp.set_response().set_aa()
+    .add_question(new DNSQuestion("www.google.com", ns_t_a));
+  rsp.set_rcode(ns_r_notimpl);
+  EXPECT_CALL(server_, OnRequest("www.google.com", ns_t_a))
+    .WillOnce(SetReply(&server_, &rsp));
+  HostResult result;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  // ARES_FLAG_NOCHECKRESP not set, so NOTIMPL consumed
+  EXPECT_EQ(ARES_ECONNREFUSED, result.status_);
+}
+
+TEST_P(MockTCPChannelTest, RefusedResponse) {
+  DNSPacket rsp;
+  rsp.set_response().set_aa()
+    .add_question(new DNSQuestion("www.google.com", ns_t_a));
+  rsp.set_rcode(ns_r_refused);
+  EXPECT_CALL(server_, OnRequest("www.google.com", ns_t_a))
+    .WillOnce(SetReply(&server_, &rsp));
+  HostResult result;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  // ARES_FLAG_NOCHECKRESP not set, so REFUSED consumed
+  EXPECT_EQ(ARES_ECONNREFUSED, result.status_);
+}
+
+TEST_P(MockTCPChannelTest, YXDomainResponse) {
+  DNSPacket rsp;
+  rsp.set_response().set_aa()
+    .add_question(new DNSQuestion("www.google.com", ns_t_a));
+  rsp.set_rcode(ns_r_yxdomain);
+  EXPECT_CALL(server_, OnRequest("www.google.com", ns_t_a))
+    .WillOnce(SetReply(&server_, &rsp));
+  HostResult result;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  EXPECT_EQ(ARES_ENODATA, result.status_);
+}
+
+class MockExtraOptsTest
+    : public MockChannelOptsTest,
+      public ::testing::WithParamInterface< std::pair<int, bool> > {
+ public:
+  MockExtraOptsTest()
+    : MockChannelOptsTest(1, GetParam().first, GetParam().second,
+                          FillOptions(&opts_),
+                          ARES_OPT_SOCK_SNDBUF|ARES_OPT_SOCK_RCVBUF) {}
+  static struct ares_options* FillOptions(struct ares_options * opts) {
+    memset(opts, 0, sizeof(struct ares_options));
+    // Set a few options that affect socket communications
+    opts->socket_send_buffer_size = 514;
+    opts->socket_receive_buffer_size = 514;
+    return opts;
+  }
+ private:
+  struct ares_options opts_;
+};
+
+TEST_P(MockExtraOptsTest, SimpleQuery) {
+  ares_set_local_ip4(channel_, 0x7F000001);
+  byte addr6[16] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01};
+  ares_set_local_ip6(channel_, addr6);
+  ares_set_local_dev(channel_, "dummy");
+
+  DNSPacket rsp;
+  rsp.set_response().set_aa()
+    .add_question(new DNSQuestion("www.google.com", ns_t_a))
+    .add_answer(new DNSARR("www.google.com", 100, {2, 3, 4, 5}));
+  ON_CALL(server_, OnRequest("www.google.com", ns_t_a))
+    .WillByDefault(SetReply(&server_, &rsp));
+
+  HostResult result;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  std::stringstream ss;
+  ss << result.host_;
+  EXPECT_EQ("{'www.google.com' aliases=[] addrs=[2.3.4.5]}", ss.str());
+}
+
+class MockFlagsChannelOptsTest
+    : public MockChannelOptsTest,
+      public ::testing::WithParamInterface< std::pair<int, bool> > {
+ public:
+  MockFlagsChannelOptsTest(int flags)
+    : MockChannelOptsTest(1, GetParam().first, GetParam().second,
+                          FillOptions(&opts_, flags), ARES_OPT_FLAGS) {}
+  static struct ares_options* FillOptions(struct ares_options * opts, int flags) {
+    memset(opts, 0, sizeof(struct ares_options));
+    opts->flags = flags;
+    return opts;
+  }
+ private:
+  struct ares_options opts_;
+};
+
+class MockNoCheckRespChannelTest : public MockFlagsChannelOptsTest {
+ public:
+  MockNoCheckRespChannelTest() : MockFlagsChannelOptsTest(ARES_FLAG_NOCHECKRESP) {}
+};
+
+TEST_P(MockNoCheckRespChannelTest, ServFailResponse) {
+  DNSPacket rsp;
+  rsp.set_response().set_aa()
+    .add_question(new DNSQuestion("www.google.com", ns_t_a));
+  rsp.set_rcode(ns_r_servfail);
+  ON_CALL(server_, OnRequest("www.google.com", ns_t_a))
+    .WillByDefault(SetReply(&server_, &rsp));
+  HostResult result;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  EXPECT_EQ(ARES_ESERVFAIL, result.status_);
+}
+
+TEST_P(MockNoCheckRespChannelTest, NotImplResponse) {
+  DNSPacket rsp;
+  rsp.set_response().set_aa()
+    .add_question(new DNSQuestion("www.google.com", ns_t_a));
+  rsp.set_rcode(ns_r_notimpl);
+  ON_CALL(server_, OnRequest("www.google.com", ns_t_a))
+    .WillByDefault(SetReply(&server_, &rsp));
+  HostResult result;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  EXPECT_EQ(ARES_ENOTIMP, result.status_);
+}
+
+TEST_P(MockNoCheckRespChannelTest, RefusedResponse) {
+  DNSPacket rsp;
+  rsp.set_response().set_aa()
+    .add_question(new DNSQuestion("www.google.com", ns_t_a));
+  rsp.set_rcode(ns_r_refused);
+  ON_CALL(server_, OnRequest("www.google.com", ns_t_a))
+    .WillByDefault(SetReply(&server_, &rsp));
+  HostResult result;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  EXPECT_EQ(ARES_EREFUSED, result.status_);
+}
+
+class MockEDNSChannelTest : public MockFlagsChannelOptsTest {
+ public:
+  MockEDNSChannelTest() : MockFlagsChannelOptsTest(ARES_FLAG_EDNS) {}
+};
+
+TEST_P(MockEDNSChannelTest, RetryWithoutEDNS) {
+  DNSPacket rspfail;
+  rspfail.set_response().set_aa().set_rcode(ns_r_servfail)
+    .add_question(new DNSQuestion("www.google.com", ns_t_a));
+  DNSPacket rspok;
+  rspok.set_response()
+    .add_question(new DNSQuestion("www.google.com", ns_t_a))
+    .add_answer(new DNSARR("www.google.com", 100, {1, 2, 3, 4}));
+  EXPECT_CALL(server_, OnRequest("www.google.com", ns_t_a))
+    .WillOnce(SetReply(&server_, &rspfail))
+    .WillOnce(SetReply(&server_, &rspok));
+  HostResult result;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  std::stringstream ss;
+  ss << result.host_;
+  EXPECT_EQ("{'www.google.com' aliases=[] addrs=[1.2.3.4]}", ss.str());
+}
+
+TEST_P(MockChannelTest, SearchDomains) {
+  DNSPacket nofirst;
+  nofirst.set_response().set_aa().set_rcode(ns_r_nxdomain)
+    .add_question(new DNSQuestion("www.first.com", ns_t_a));
+  ON_CALL(server_, OnRequest("www.first.com", ns_t_a))
+    .WillByDefault(SetReply(&server_, &nofirst));
+  DNSPacket nosecond;
+  nosecond.set_response().set_aa().set_rcode(ns_r_nxdomain)
+    .add_question(new DNSQuestion("www.second.org", ns_t_a));
+  ON_CALL(server_, OnRequest("www.second.org", ns_t_a))
+    .WillByDefault(SetReply(&server_, &nosecond));
+  DNSPacket yesthird;
+  yesthird.set_response().set_aa()
+    .add_question(new DNSQuestion("www.third.gov", ns_t_a))
+    .add_answer(new DNSARR("www.third.gov", 0x0200, {2, 3, 4, 5}));
+  ON_CALL(server_, OnRequest("www.third.gov", ns_t_a))
+    .WillByDefault(SetReply(&server_, &yesthird));
+
+  HostResult result;
+  ares_gethostbyname(channel_, "www", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  std::stringstream ss;
+  ss << result.host_;
+  EXPECT_EQ("{'www.third.gov' aliases=[] addrs=[2.3.4.5]}", ss.str());
+}
+
+// Relies on retries so is UDP-only
+TEST_P(MockUDPChannelTest, SearchDomainsWithResentReply) {
+  DNSPacket nofirst;
+  nofirst.set_response().set_aa().set_rcode(ns_r_nxdomain)
+    .add_question(new DNSQuestion("www.first.com", ns_t_a));
+  EXPECT_CALL(server_, OnRequest("www.first.com", ns_t_a))
+    .WillOnce(SetReply(&server_, &nofirst));
+  DNSPacket nosecond;
+  nosecond.set_response().set_aa().set_rcode(ns_r_nxdomain)
+    .add_question(new DNSQuestion("www.second.org", ns_t_a));
+  EXPECT_CALL(server_, OnRequest("www.second.org", ns_t_a))
+    .WillOnce(SetReply(&server_, &nosecond));
+  DNSPacket yesthird;
+  yesthird.set_response().set_aa()
+    .add_question(new DNSQuestion("www.third.gov", ns_t_a))
+    .add_answer(new DNSARR("www.third.gov", 0x0200, {2, 3, 4, 5}));
+  // Before sending the real answer, resend an earlier reply
+  EXPECT_CALL(server_, OnRequest("www.third.gov", ns_t_a))
+    .WillOnce(DoAll(SetReply(&server_, &nofirst),
+                    SetReplyQID(&server_, 123)))
+    .WillOnce(DoAll(SetReply(&server_, &yesthird),
+                    SetReplyQID(&server_, -1)));
+
+  HostResult result;
+  ares_gethostbyname(channel_, "www", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  std::stringstream ss;
+  ss << result.host_;
+  EXPECT_EQ("{'www.third.gov' aliases=[] addrs=[2.3.4.5]}", ss.str());
+}
+
+TEST_P(MockChannelTest, SearchDomainsBare) {
+  DNSPacket nofirst;
+  nofirst.set_response().set_aa().set_rcode(ns_r_nxdomain)
+    .add_question(new DNSQuestion("www.first.com", ns_t_a));
+  ON_CALL(server_, OnRequest("www.first.com", ns_t_a))
+    .WillByDefault(SetReply(&server_, &nofirst));
+  DNSPacket nosecond;
+  nosecond.set_response().set_aa().set_rcode(ns_r_nxdomain)
+    .add_question(new DNSQuestion("www.second.org", ns_t_a));
+  ON_CALL(server_, OnRequest("www.second.org", ns_t_a))
+    .WillByDefault(SetReply(&server_, &nosecond));
+  DNSPacket nothird;
+  nothird.set_response().set_aa().set_rcode(ns_r_nxdomain)
+    .add_question(new DNSQuestion("www.third.gov", ns_t_a));
+  ON_CALL(server_, OnRequest("www.third.gov", ns_t_a))
+    .WillByDefault(SetReply(&server_, &nothird));
+  DNSPacket yesbare;
+  yesbare.set_response().set_aa()
+    .add_question(new DNSQuestion("www", ns_t_a))
+    .add_answer(new DNSARR("www", 0x0200, {2, 3, 4, 5}));
+  ON_CALL(server_, OnRequest("www", ns_t_a))
+    .WillByDefault(SetReply(&server_, &yesbare));
+
+  HostResult result;
+  ares_gethostbyname(channel_, "www", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  std::stringstream ss;
+  ss << result.host_;
+  EXPECT_EQ("{'www' aliases=[] addrs=[2.3.4.5]}", ss.str());
+}
+
+TEST_P(MockChannelTest, SearchNoDataThenSuccess) {
+  // First two search domains recognize the name but have no A records.
+  DNSPacket nofirst;
+  nofirst.set_response().set_aa()
+    .add_question(new DNSQuestion("www.first.com", ns_t_a));
+  ON_CALL(server_, OnRequest("www.first.com", ns_t_a))
+    .WillByDefault(SetReply(&server_, &nofirst));
+  DNSPacket nosecond;
+  nosecond.set_response().set_aa()
+    .add_question(new DNSQuestion("www.second.org", ns_t_a));
+  ON_CALL(server_, OnRequest("www.second.org", ns_t_a))
+    .WillByDefault(SetReply(&server_, &nosecond));
+  DNSPacket yesthird;
+  yesthird.set_response().set_aa()
+    .add_question(new DNSQuestion("www.third.gov", ns_t_a))
+    .add_answer(new DNSARR("www.third.gov", 0x0200, {2, 3, 4, 5}));
+  ON_CALL(server_, OnRequest("www.third.gov", ns_t_a))
+    .WillByDefault(SetReply(&server_, &yesthird));
+
+  HostResult result;
+  ares_gethostbyname(channel_, "www", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  std::stringstream ss;
+  ss << result.host_;
+  EXPECT_EQ("{'www.third.gov' aliases=[] addrs=[2.3.4.5]}", ss.str());
+}
+
+TEST_P(MockChannelTest, SearchNoDataThenNoDataBare) {
+  // First two search domains recognize the name but have no A records.
+  DNSPacket nofirst;
+  nofirst.set_response().set_aa()
+    .add_question(new DNSQuestion("www.first.com", ns_t_a));
+  ON_CALL(server_, OnRequest("www.first.com", ns_t_a))
+    .WillByDefault(SetReply(&server_, &nofirst));
+  DNSPacket nosecond;
+  nosecond.set_response().set_aa()
+    .add_question(new DNSQuestion("www.second.org", ns_t_a));
+  ON_CALL(server_, OnRequest("www.second.org", ns_t_a))
+    .WillByDefault(SetReply(&server_, &nosecond));
+  DNSPacket nothird;
+  nothird.set_response().set_aa()
+    .add_question(new DNSQuestion("www.third.gov", ns_t_a));
+  ON_CALL(server_, OnRequest("www.third.gov", ns_t_a))
+    .WillByDefault(SetReply(&server_, &nothird));
+  DNSPacket nobare;
+  nobare.set_response().set_aa()
+    .add_question(new DNSQuestion("www", ns_t_a));
+  ON_CALL(server_, OnRequest("www", ns_t_a))
+    .WillByDefault(SetReply(&server_, &nobare));
+
+  HostResult result;
+  ares_gethostbyname(channel_, "www", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  EXPECT_EQ(ARES_ENODATA, result.status_);
+}
+
+TEST_P(MockChannelTest, SearchNoDataThenFail) {
+  // First two search domains recognize the name but have no A records.
+  DNSPacket nofirst;
+  nofirst.set_response().set_aa()
+    .add_question(new DNSQuestion("www.first.com", ns_t_a));
+  ON_CALL(server_, OnRequest("www.first.com", ns_t_a))
+    .WillByDefault(SetReply(&server_, &nofirst));
+  DNSPacket nosecond;
+  nosecond.set_response().set_aa()
+    .add_question(new DNSQuestion("www.second.org", ns_t_a));
+  ON_CALL(server_, OnRequest("www.second.org", ns_t_a))
+    .WillByDefault(SetReply(&server_, &nosecond));
+  DNSPacket nothird;
+  nothird.set_response().set_aa()
+    .add_question(new DNSQuestion("www.third.gov", ns_t_a));
+  ON_CALL(server_, OnRequest("www.third.gov", ns_t_a))
+    .WillByDefault(SetReply(&server_, &nothird));
+  DNSPacket nobare;
+  nobare.set_response().set_aa().set_rcode(ns_r_nxdomain)
+    .add_question(new DNSQuestion("www", ns_t_a));
+  ON_CALL(server_, OnRequest("www", ns_t_a))
+    .WillByDefault(SetReply(&server_, &nobare));
+
+  HostResult result;
+  ares_gethostbyname(channel_, "www", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  EXPECT_EQ(ARES_ENODATA, result.status_);
+}
+
+TEST_P(MockChannelTest, SearchAllocFailure) {
+  SearchResult result;
+  SetAllocFail(1);
+  ares_search(channel_, "fully.qualified.", ns_c_in, ns_t_a, SearchCallback, &result);
+  /* Already done */
+  EXPECT_TRUE(result.done_);
+  EXPECT_EQ(ARES_ENOMEM, result.status_);
+}
+
+TEST_P(MockChannelTest, SearchHighNdots) {
+  DNSPacket nobare;
+  nobare.set_response().set_aa().set_rcode(ns_r_nxdomain)
+    .add_question(new DNSQuestion("a.b.c.w.w.w", ns_t_a));
+  ON_CALL(server_, OnRequest("a.b.c.w.w.w", ns_t_a))
+    .WillByDefault(SetReply(&server_, &nobare));
+  DNSPacket yesfirst;
+  yesfirst.set_response().set_aa()
+    .add_question(new DNSQuestion("a.b.c.w.w.w.first.com", ns_t_a))
+    .add_answer(new DNSARR("a.b.c.w.w.w.first.com", 0x0200, {2, 3, 4, 5}));
+  ON_CALL(server_, OnRequest("a.b.c.w.w.w.first.com", ns_t_a))
+    .WillByDefault(SetReply(&server_, &yesfirst));
+
+  SearchResult result;
+  ares_search(channel_, "a.b.c.w.w.w", ns_c_in, ns_t_a, SearchCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  EXPECT_EQ(ARES_SUCCESS, result.status_);
+  std::stringstream ss;
+  ss << PacketToString(result.data_);
+  EXPECT_EQ("RSP QRY AA NOERROR Q:{'a.b.c.w.w.w.first.com' IN A} "
+            "A:{'a.b.c.w.w.w.first.com' IN A TTL=512 2.3.4.5}",
+            ss.str());
+}
+
+TEST_P(MockChannelTest, UnspecifiedFamilyV6) {
+  DNSPacket rsp6;
+  rsp6.set_response().set_aa()
+    .add_question(new DNSQuestion("example.com", ns_t_aaaa))
+    .add_answer(new DNSAaaaRR("example.com", 100,
+                              {0x21, 0x21, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                               0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x03}));
+  ON_CALL(server_, OnRequest("example.com", ns_t_aaaa))
+    .WillByDefault(SetReply(&server_, &rsp6));
+
+  HostResult result;
+  ares_gethostbyname(channel_, "example.com.", AF_UNSPEC, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  std::stringstream ss;
+  ss << result.host_;
+  // Default to IPv6 when both are available.
+  EXPECT_EQ("{'example.com' aliases=[] addrs=[2121:0000:0000:0000:0000:0000:0000:0303]}", ss.str());
+}
+
+TEST_P(MockChannelTest, UnspecifiedFamilyV4) {
+  DNSPacket rsp6;
+  rsp6.set_response().set_aa()
+    .add_question(new DNSQuestion("example.com", ns_t_aaaa));
+  ON_CALL(server_, OnRequest("example.com", ns_t_aaaa))
+    .WillByDefault(SetReply(&server_, &rsp6));
+  DNSPacket rsp4;
+  rsp4.set_response().set_aa()
+    .add_question(new DNSQuestion("example.com", ns_t_a))
+    .add_answer(new DNSARR("example.com", 100, {2, 3, 4, 5}));
+  ON_CALL(server_, OnRequest("example.com", ns_t_a))
+    .WillByDefault(SetReply(&server_, &rsp4));
+
+  HostResult result;
+  ares_gethostbyname(channel_, "example.com.", AF_UNSPEC, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  std::stringstream ss;
+  ss << result.host_;
+  EXPECT_EQ("{'example.com' aliases=[] addrs=[2.3.4.5]}", ss.str());
+}
+
+TEST_P(MockChannelTest, UnspecifiedFamilyNoData) {
+  DNSPacket rsp6;
+  rsp6.set_response().set_aa()
+    .add_question(new DNSQuestion("example.com", ns_t_aaaa))
+    .add_answer(new DNSCnameRR("example.com", 100, "elsewhere.com"));
+  ON_CALL(server_, OnRequest("example.com", ns_t_aaaa))
+    .WillByDefault(SetReply(&server_, &rsp6));
+  DNSPacket rsp4;
+  rsp4.set_response().set_aa()
+    .add_question(new DNSQuestion("example.com", ns_t_a));
+  ON_CALL(server_, OnRequest("example.com", ns_t_a))
+    .WillByDefault(SetReply(&server_, &rsp4));
+
+  HostResult result;
+  ares_gethostbyname(channel_, "example.com.", AF_UNSPEC, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  std::stringstream ss;
+  ss << result.host_;
+  EXPECT_EQ("{'' aliases=[] addrs=[]}", ss.str());
+}
+
+TEST_P(MockChannelTest, UnspecifiedFamilyCname6A4) {
+  DNSPacket rsp6;
+  rsp6.set_response().set_aa()
+    .add_question(new DNSQuestion("example.com", ns_t_aaaa))
+    .add_answer(new DNSCnameRR("example.com", 100, "elsewhere.com"));
+  ON_CALL(server_, OnRequest("example.com", ns_t_aaaa))
+    .WillByDefault(SetReply(&server_, &rsp6));
+  DNSPacket rsp4;
+  rsp4.set_response().set_aa()
+    .add_question(new DNSQuestion("example.com", ns_t_a))
+    .add_answer(new DNSARR("example.com", 100, {1, 2, 3, 4}));
+  ON_CALL(server_, OnRequest("example.com", ns_t_a))
+    .WillByDefault(SetReply(&server_, &rsp4));
+
+  HostResult result;
+  ares_gethostbyname(channel_, "example.com.", AF_UNSPEC, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  std::stringstream ss;
+  ss << result.host_;
+  EXPECT_EQ("{'example.com' aliases=[] addrs=[1.2.3.4]}", ss.str());
+}
+
+TEST_P(MockChannelTest, ExplicitIP) {
+  HostResult result;
+  ares_gethostbyname(channel_, "1.2.3.4", AF_INET, HostCallback, &result);
+  EXPECT_TRUE(result.done_);  // Immediate return
+  EXPECT_EQ(ARES_SUCCESS, result.status_);
+  std::stringstream ss;
+  ss << result.host_;
+  EXPECT_EQ("{'1.2.3.4' aliases=[] addrs=[1.2.3.4]}", ss.str());
+}
+
+TEST_P(MockChannelTest, ExplicitIPAllocFail) {
+  HostResult result;
+  SetAllocSizeFail(strlen("1.2.3.4") + 1);
+  ares_gethostbyname(channel_, "1.2.3.4", AF_INET, HostCallback, &result);
+  EXPECT_TRUE(result.done_);  // Immediate return
+  EXPECT_EQ(ARES_ENOMEM, result.status_);
+}
+
+TEST_P(MockChannelTest, SortListV4) {
+  DNSPacket rsp;
+  rsp.set_response().set_aa()
+    .add_question(new DNSQuestion("example.com", ns_t_a))
+    .add_answer(new DNSARR("example.com", 100, {22, 23, 24, 25}))
+    .add_answer(new DNSARR("example.com", 100, {12, 13, 14, 15}))
+    .add_answer(new DNSARR("example.com", 100, {2, 3, 4, 5}));
+  ON_CALL(server_, OnRequest("example.com", ns_t_a))
+    .WillByDefault(SetReply(&server_, &rsp));
+
+  {
+    EXPECT_EQ(ARES_SUCCESS, ares_set_sortlist(channel_, "12.13.0.0/255.255.0.0 1234::5678"));
+    HostResult result;
+    ares_gethostbyname(channel_, "example.com.", AF_INET, HostCallback, &result);
+    Process();
+    EXPECT_TRUE(result.done_);
+    std::stringstream ss;
+    ss << result.host_;
+    EXPECT_EQ("{'example.com' aliases=[] addrs=[12.13.14.15, 22.23.24.25, 2.3.4.5]}", ss.str());
+  }
+  {
+    EXPECT_EQ(ARES_SUCCESS, ares_set_sortlist(channel_, "2.3.0.0/16 130.140.150.160/26"));
+    HostResult result;
+    ares_gethostbyname(channel_, "example.com.", AF_INET, HostCallback, &result);
+    Process();
+    EXPECT_TRUE(result.done_);
+    std::stringstream ss;
+    ss << result.host_;
+    EXPECT_EQ("{'example.com' aliases=[] addrs=[2.3.4.5, 22.23.24.25, 12.13.14.15]}", ss.str());
+  }
+  struct ares_options options;
+  memset(&options, 0, sizeof(options));
+  int optmask = 0;
+  EXPECT_EQ(ARES_SUCCESS, ares_save_options(channel_, &options, &optmask));
+  EXPECT_TRUE((optmask & ARES_OPT_SORTLIST) == ARES_OPT_SORTLIST);
+  ares_destroy_options(&options);
+}
+
+TEST_P(MockChannelTest, SortListV6) {
+  DNSPacket rsp;
+  rsp.set_response().set_aa()
+    .add_question(new DNSQuestion("example.com", ns_t_aaaa))
+    .add_answer(new DNSAaaaRR("example.com", 100,
+                              {0x11, 0x11, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                               0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x02}))
+    .add_answer(new DNSAaaaRR("example.com", 100,
+                              {0x21, 0x21, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+                               0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x03}));
+  ON_CALL(server_, OnRequest("example.com", ns_t_aaaa))
+    .WillByDefault(SetReply(&server_, &rsp));
+
+  {
+    ares_set_sortlist(channel_, "1111::/16 2.3.0.0/255.255.0.0");
+    HostResult result;
+    ares_gethostbyname(channel_, "example.com.", AF_INET6, HostCallback, &result);
+    Process();
+    EXPECT_TRUE(result.done_);
+    std::stringstream ss;
+    ss << result.host_;
+    EXPECT_EQ("{'example.com' aliases=[] addrs=[1111:0000:0000:0000:0000:0000:0000:0202, "
+              "2121:0000:0000:0000:0000:0000:0000:0303]}", ss.str());
+  }
+  {
+    ares_set_sortlist(channel_, "2121::/8");
+    HostResult result;
+    ares_gethostbyname(channel_, "example.com.", AF_INET6, HostCallback, &result);
+    Process();
+    EXPECT_TRUE(result.done_);
+    std::stringstream ss;
+    ss << result.host_;
+    EXPECT_EQ("{'example.com' aliases=[] addrs=[2121:0000:0000:0000:0000:0000:0000:0303, "
+              "1111:0000:0000:0000:0000:0000:0000:0202]}", ss.str());
+  }
+}
+
+// Relies on retries so is UDP-only
+TEST_P(MockUDPChannelTest, SearchDomainsAllocFail) {
+  DNSPacket nofirst;
+  nofirst.set_response().set_aa().set_rcode(ns_r_nxdomain)
+    .add_question(new DNSQuestion("www.first.com", ns_t_a));
+  ON_CALL(server_, OnRequest("www.first.com", ns_t_a))
+    .WillByDefault(SetReply(&server_, &nofirst));
+  DNSPacket nosecond;
+  nosecond.set_response().set_aa().set_rcode(ns_r_nxdomain)
+    .add_question(new DNSQuestion("www.second.org", ns_t_a));
+  ON_CALL(server_, OnRequest("www.second.org", ns_t_a))
+    .WillByDefault(SetReply(&server_, &nosecond));
+  DNSPacket yesthird;
+  yesthird.set_response().set_aa()
+    .add_question(new DNSQuestion("www.third.gov", ns_t_a))
+    .add_answer(new DNSARR("www.third.gov", 0x0200, {2, 3, 4, 5}));
+  ON_CALL(server_, OnRequest("www.third.gov", ns_t_a))
+    .WillByDefault(SetReply(&server_, &yesthird));
+
+  // Fail a variety of different memory allocations, and confirm
+  // that the operation either fails with ENOMEM or succeeds
+  // with the expected result.
+  const int kCount = 34;
+  HostResult results[kCount];
+  for (int ii = 1; ii <= kCount; ii++) {
+    HostResult* result = &(results[ii - 1]);
+    ClearFails();
+    SetAllocFail(ii);
+    ares_gethostbyname(channel_, "www", AF_INET, HostCallback, result);
+    Process();
+    EXPECT_TRUE(result->done_);
+    if (result->status_ == ARES_SUCCESS) {
+      std::stringstream ss;
+      ss << result->host_;
+      EXPECT_EQ("{'www.third.gov' aliases=[] addrs=[2.3.4.5]}", ss.str()) << " failed alloc #" << ii;
+      if (verbose) std::cerr << "Succeeded despite failure of alloc #" << ii << std::endl;
+    }
+  }
+
+  // Explicitly destroy the channel now, so that the HostResult objects
+  // are still valid (in case any pending work refers to them).
+  ares_destroy(channel_);
+  channel_ = nullptr;
+}
+
+// Relies on retries so is UDP-only
+TEST_P(MockUDPChannelTest, Resend) {
+  std::vector<byte> nothing;
+  DNSPacket reply;
+  reply.set_response().set_aa()
+    .add_question(new DNSQuestion("www.google.com", ns_t_a))
+    .add_answer(new DNSARR("www.google.com", 0x0100, {0x01, 0x02, 0x03, 0x04}));
+
+  EXPECT_CALL(server_, OnRequest("www.google.com", ns_t_a))
+    .WillOnce(SetReplyData(&server_, nothing))
+    .WillOnce(SetReplyData(&server_, nothing))
+    .WillOnce(SetReply(&server_, &reply));
+
+  HostResult result;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  EXPECT_EQ(2, result.timeouts_);
+  std::stringstream ss;
+  ss << result.host_;
+  EXPECT_EQ("{'www.google.com' aliases=[] addrs=[1.2.3.4]}", ss.str());
+}
+
+TEST_P(MockChannelTest, CancelImmediate) {
+  HostResult result;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+  ares_cancel(channel_);
+  EXPECT_TRUE(result.done_);
+  EXPECT_EQ(ARES_ECANCELLED, result.status_);
+  EXPECT_EQ(0, result.timeouts_);
+}
+
+// Relies on retries so is UDP-only
+TEST_P(MockUDPChannelTest, CancelLater) {
+  std::vector<byte> nothing;
+
+  // On second request, cancel the channel.
+  EXPECT_CALL(server_, OnRequest("www.google.com", ns_t_a))
+    .WillOnce(SetReplyData(&server_, nothing))
+    .WillOnce(CancelChannel(&server_, channel_));
+
+  HostResult result;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  EXPECT_EQ(ARES_ECANCELLED, result.status_);
+  EXPECT_EQ(0, result.timeouts_);
+}
+
+TEST_P(MockChannelTest, GetHostByNameDestroyAbsolute) {
+  HostResult result;
+  ares_gethostbyname(channel_, "www.google.com.", AF_INET, HostCallback, &result);
+
+  ares_destroy(channel_);
+  channel_ = nullptr;
+
+  EXPECT_TRUE(result.done_);  // Synchronous
+  EXPECT_EQ(ARES_EDESTRUCTION, result.status_);
+  EXPECT_EQ(0, result.timeouts_);
+}
+
+TEST_P(MockChannelTest, GetHostByNameDestroyRelative) {
+  HostResult result;
+  ares_gethostbyname(channel_, "www", AF_INET, HostCallback, &result);
+
+  ares_destroy(channel_);
+  channel_ = nullptr;
+
+  EXPECT_TRUE(result.done_);  // Synchronous
+  EXPECT_EQ(ARES_EDESTRUCTION, result.status_);
+  EXPECT_EQ(0, result.timeouts_);
+}
+
+TEST_P(MockChannelTest, GetHostByAddrDestroy) {
+  unsigned char gdns_addr4[4] = {0x08, 0x08, 0x08, 0x08};
+  HostResult result;
+  ares_gethostbyaddr(channel_, gdns_addr4, sizeof(gdns_addr4), AF_INET, HostCallback, &result);
+
+  ares_destroy(channel_);
+  channel_ = nullptr;
+
+  EXPECT_TRUE(result.done_);  // Synchronous
+  EXPECT_EQ(ARES_EDESTRUCTION, result.status_);
+  EXPECT_EQ(0, result.timeouts_);
+}
+
+#ifndef WIN32
+TEST_P(MockChannelTest, HostAlias) {
+  DNSPacket reply;
+  reply.set_response().set_aa()
+    .add_question(new DNSQuestion("www.google.com", ns_t_a))
+    .add_answer(new DNSARR("www.google.com", 0x0100, {0x01, 0x02, 0x03, 0x04}));
+  ON_CALL(server_, OnRequest("www.google.com", ns_t_a))
+    .WillByDefault(SetReply(&server_, &reply));
+
+  TempFile aliases("\n\n# www commentedout\nwww www.google.com\n");
+  EnvValue with_env("HOSTALIASES", aliases.filename());
+
+  HostResult result;
+  ares_gethostbyname(channel_, "www", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  std::stringstream ss;
+  ss << result.host_;
+  EXPECT_EQ("{'www.google.com' aliases=[] addrs=[1.2.3.4]}", ss.str());
+}
+
+TEST_P(MockChannelTest, HostAliasMissing) {
+  DNSPacket yesfirst;
+  yesfirst.set_response().set_aa()
+    .add_question(new DNSQuestion("www.first.com", ns_t_a))
+    .add_answer(new DNSARR("www.first.com", 0x0200, {2, 3, 4, 5}));
+  ON_CALL(server_, OnRequest("www.first.com", ns_t_a))
+    .WillByDefault(SetReply(&server_, &yesfirst));
+
+  TempFile aliases("\n\n# www commentedout\nww www.google.com\n");
+  EnvValue with_env("HOSTALIASES", aliases.filename());
+  HostResult result;
+  ares_gethostbyname(channel_, "www", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  std::stringstream ss;
+  ss << result.host_;
+  EXPECT_EQ("{'www.first.com' aliases=[] addrs=[2.3.4.5]}", ss.str());
+}
+
+TEST_P(MockChannelTest, HostAliasMissingFile) {
+  DNSPacket yesfirst;
+  yesfirst.set_response().set_aa()
+    .add_question(new DNSQuestion("www.first.com", ns_t_a))
+    .add_answer(new DNSARR("www.first.com", 0x0200, {2, 3, 4, 5}));
+  ON_CALL(server_, OnRequest("www.first.com", ns_t_a))
+    .WillByDefault(SetReply(&server_, &yesfirst));
+
+  EnvValue with_env("HOSTALIASES", "bogus.mcfile");
+  HostResult result;
+  ares_gethostbyname(channel_, "www", AF_INET, HostCallback, &result);
+  Process();
+  EXPECT_TRUE(result.done_);
+  std::stringstream ss;
+  ss << result.host_;
+  EXPECT_EQ("{'www.first.com' aliases=[] addrs=[2.3.4.5]}", ss.str());
+}
+
+TEST_P(MockChannelTest, HostAliasUnreadable) {
+  TempFile aliases("www www.google.com\n");
+  chmod(aliases.filename(), 0);
+  EnvValue with_env("HOSTALIASES", aliases.filename());
+
+  HostResult result;
+  ares_gethostbyname(channel_, "www", AF_INET, HostCallback, &result);
+  EXPECT_TRUE(result.done_);
+  EXPECT_EQ(ARES_EFILE, result.status_);
+  chmod(aliases.filename(), 0777);
+}
+#endif
+
+class MockMultiServerChannelTest
+  : public MockChannelOptsTest,
+    public ::testing::WithParamInterface< std::pair<int, bool> > {
+ public:
+  MockMultiServerChannelTest(bool rotate)
+    : MockChannelOptsTest(3, GetParam().first, GetParam().second, nullptr, rotate ? ARES_OPT_ROTATE : 0) {}
+  void CheckExample() {
+    HostResult result;
+    ares_gethostbyname(channel_, "www.example.com.", AF_INET, HostCallback, &result);
+    Process();
+    EXPECT_TRUE(result.done_);
+    std::stringstream ss;
+    ss << result.host_;
+    EXPECT_EQ("{'www.example.com' aliases=[] addrs=[2.3.4.5]}", ss.str());
+  }
+};
+
+class RotateMultiMockTest : public MockMultiServerChannelTest {
+ public:
+  RotateMultiMockTest() : MockMultiServerChannelTest(true) {}
+};
+
+class NoRotateMultiMockTest : public MockMultiServerChannelTest {
+ public:
+  NoRotateMultiMockTest() : MockMultiServerChannelTest(false) {}
+};
+
+
+TEST_P(RotateMultiMockTest, ThirdServer) {
+  DNSPacket servfailrsp;
+  servfailrsp.set_response().set_aa().set_rcode(ns_r_servfail)
+    .add_question(new DNSQuestion("www.example.com", ns_t_a));
+  DNSPacket notimplrsp;
+  notimplrsp.set_response().set_aa().set_rcode(ns_r_notimpl)
+    .add_question(new DNSQuestion("www.example.com", ns_t_a));
+  DNSPacket okrsp;
+  okrsp.set_response().set_aa()
+    .add_question(new DNSQuestion("www.example.com", ns_t_a))
+    .add_answer(new DNSARR("www.example.com", 100, {2,3,4,5}));
+
+  EXPECT_CALL(*servers_[0], OnRequest("www.example.com", ns_t_a))
+    .WillOnce(SetReply(servers_[0].get(), &servfailrsp));
+  EXPECT_CALL(*servers_[1], OnRequest("www.example.com", ns_t_a))
+    .WillOnce(SetReply(servers_[1].get(), &notimplrsp));
+  EXPECT_CALL(*servers_[2], OnRequest("www.example.com", ns_t_a))
+    .WillOnce(SetReply(servers_[2].get(), &okrsp));
+  CheckExample();
+
+  // Second time around, starts from server [1].
+  EXPECT_CALL(*servers_[1], OnRequest("www.example.com", ns_t_a))
+    .WillOnce(SetReply(servers_[1].get(), &servfailrsp));
+  EXPECT_CALL(*servers_[2], OnRequest("www.example.com", ns_t_a))
+    .WillOnce(SetReply(servers_[2].get(), &notimplrsp));
+  EXPECT_CALL(*servers_[0], OnRequest("www.example.com", ns_t_a))
+    .WillOnce(SetReply(servers_[0].get(), &okrsp));
+  CheckExample();
+
+  // Third time around, starts from server [2].
+  EXPECT_CALL(*servers_[2], OnRequest("www.example.com", ns_t_a))
+    .WillOnce(SetReply(servers_[2].get(), &servfailrsp));
+  EXPECT_CALL(*servers_[0], OnRequest("www.example.com", ns_t_a))
+    .WillOnce(SetReply(servers_[0].get(), &notimplrsp));
+  EXPECT_CALL(*servers_[1], OnRequest("www.example.com", ns_t_a))
+    .WillOnce(SetReply(servers_[1].get(), &okrsp));
+  CheckExample();
+}
+
+TEST_P(NoRotateMultiMockTest, ThirdServer) {
+  DNSPacket servfailrsp;
+  servfailrsp.set_response().set_aa().set_rcode(ns_r_servfail)
+    .add_question(new DNSQuestion("www.example.com", ns_t_a));
+  DNSPacket notimplrsp;
+  notimplrsp.set_response().set_aa().set_rcode(ns_r_notimpl)
+    .add_question(new DNSQuestion("www.example.com", ns_t_a));
+  DNSPacket okrsp;
+  okrsp.set_response().set_aa()
+    .add_question(new DNSQuestion("www.example.com", ns_t_a))
+    .add_answer(new DNSARR("www.example.com", 100, {2,3,4,5}));
+
+  EXPECT_CALL(*servers_[0], OnRequest("www.example.com", ns_t_a))
+    .WillOnce(SetReply(servers_[0].get(), &servfailrsp));
+  EXPECT_CALL(*servers_[1], OnRequest("www.example.com", ns_t_a))
+    .WillOnce(SetReply(servers_[1].get(), &notimplrsp));
+  EXPECT_CALL(*servers_[2], OnRequest("www.example.com", ns_t_a))
+    .WillOnce(SetReply(servers_[2].get(), &okrsp));
+  CheckExample();
+
+  // Second time around, still starts from server [0].
+  EXPECT_CALL(*servers_[0], OnRequest("www.example.com", ns_t_a))
+    .WillOnce(SetReply(servers_[0].get(), &servfailrsp));
+  EXPECT_CALL(*servers_[1], OnRequest("www.example.com", ns_t_a))
+    .WillOnce(SetReply(servers_[1].get(), &notimplrsp));
+  EXPECT_CALL(*servers_[2], OnRequest("www.example.com", ns_t_a))
+    .WillOnce(SetReply(servers_[2].get(), &okrsp));
+  CheckExample();
+
+  // Third time around, still starts from server [0].
+  EXPECT_CALL(*servers_[0], OnRequest("www.example.com", ns_t_a))
+    .WillOnce(SetReply(servers_[0].get(), &servfailrsp));
+  EXPECT_CALL(*servers_[1], OnRequest("www.example.com", ns_t_a))
+    .WillOnce(SetReply(servers_[1].get(), &notimplrsp));
+  EXPECT_CALL(*servers_[2], OnRequest("www.example.com", ns_t_a))
+    .WillOnce(SetReply(servers_[2].get(), &okrsp));
+  CheckExample();
+}
+
+
+INSTANTIATE_TEST_CASE_P(AddressFamilies, MockChannelTest,
+                        ::testing::Values(std::make_pair<int, bool>(AF_INET, false),
+                                          std::make_pair<int, bool>(AF_INET, true),
+                                          std::make_pair<int, bool>(AF_INET6, false),
+                                          std::make_pair<int, bool>(AF_INET6, true)));
+
+INSTANTIATE_TEST_CASE_P(AddressFamilies, MockUDPChannelTest,
+                        ::testing::Values(AF_INET, AF_INET6));
+
+INSTANTIATE_TEST_CASE_P(AddressFamilies, MockTCPChannelTest,
+                        ::testing::Values(AF_INET, AF_INET6));
+
+INSTANTIATE_TEST_CASE_P(AddressFamilies, MockExtraOptsTest,
+                        ::testing::Values(std::make_pair<int, bool>(AF_INET, false),
+                                          std::make_pair<int, bool>(AF_INET, true),
+                                          std::make_pair<int, bool>(AF_INET6, false),
+                                          std::make_pair<int, bool>(AF_INET6, true)));
+
+INSTANTIATE_TEST_CASE_P(AddressFamilies, MockNoCheckRespChannelTest,
+                        ::testing::Values(std::make_pair<int, bool>(AF_INET, false),
+                                          std::make_pair<int, bool>(AF_INET, true),
+                                          std::make_pair<int, bool>(AF_INET6, false),
+                                          std::make_pair<int, bool>(AF_INET6, true)));
+
+INSTANTIATE_TEST_CASE_P(AddressFamilies, MockEDNSChannelTest,
+                        ::testing::Values(std::make_pair<int, bool>(AF_INET, false),
+                                          std::make_pair<int, bool>(AF_INET, true),
+                                          std::make_pair<int, bool>(AF_INET6, false),
+                                          std::make_pair<int, bool>(AF_INET6, true)));
+
+INSTANTIATE_TEST_CASE_P(TransportModes, RotateMultiMockTest,
+                        ::testing::Values(std::make_pair<int, bool>(AF_INET, false),
+                                          std::make_pair<int, bool>(AF_INET, true),
+                                          std::make_pair<int, bool>(AF_INET6, false),
+                                          std::make_pair<int, bool>(AF_INET6, true)));
+
+INSTANTIATE_TEST_CASE_P(TransportModes, NoRotateMultiMockTest,
+                        ::testing::Values(std::make_pair<int, bool>(AF_INET, false),
+                                          std::make_pair<int, bool>(AF_INET, true),
+                                          std::make_pair<int, bool>(AF_INET6, false),
+                                          std::make_pair<int, bool>(AF_INET6, true)));
+
+}  // namespace test
+}  // namespace ares