[DS#1] ResolverTest: assign specified socket type for GetAddrInfo_Dns64*

If the socket type is not specified, every address will appear
twice, once for SOCK_STREAM and one for SOCK_DGRAM. Just pick
one (SOCK_DGRAM in this commit) because the addresses for the
the second query of different socket types are responded to by
the cache. This helps to avoid that misunderstand the dns query
count of dns responder while people read the code.

Also:
1. Reword comments.
2. Simply the dns result checking via testing utility.
3. Use aggregate initialization on stuct addrinfo.

Bug: 159305929
Test: atest ResolverTest
Change-Id: I13a1a1c183b94cb921a01c4fc0cc6c7c7ba7227e

1 files changed, 61 insertions, 71 deletions

diff --git a/tests/resolv_integration_test.cpp b/tests/resolv_integration_test.cpp
index 76427f37..eb9a3f1e 100644
--- a/tests/resolv_integration_test.cpp
+++ b/tests/resolv_integration_test.cpp
@@ -3074,32 +3074,29 @@ TEST_F(ResolverTest, GetAddrInfo_Dns64Synthesize) {
     EXPECT_TRUE(mDnsClient.resolvService()->startPrefix64Discovery(TEST_NETID).isOk());
     EXPECT_TRUE(WaitForNat64Prefix(EXPECT_FOUND));
 
-    // hints are necessary in order to let netd know which type of addresses the caller is
-    // interested in.
-    const addrinfo hints = {.ai_family = AF_UNSPEC};
+    // If the socket type is not specified, every address will appear twice, once for
+    // SOCK_STREAM and one for SOCK_DGRAM. Just pick one because the addresses for
+    // the second query of different socket type are responded by the cache.
+    // See android_getaddrinfofornetcontext in packages/modules/DnsResolver/getaddrinfo.cpp
+    const addrinfo hints = {.ai_family = AF_UNSPEC, .ai_socktype = SOCK_DGRAM};
     ScopedAddrinfo result = safe_getaddrinfo("v4only", nullptr, &hints);
     EXPECT_TRUE(result != nullptr);
-    // TODO: BUG: there should only be two queries, one AAAA (which returns no records) and one A
-    // (which returns 1.2.3.4). But there is an extra AAAA.
-    EXPECT_EQ(3U, GetNumQueries(dns, host_name));
-
-    std::string result_str = ToString(result);
-    EXPECT_EQ(result_str, "64:ff9b::102:304");
+    // Expect that there are two queries, one AAAA (which returns no records) and one A
+    // (which returns 1.2.3.4).
+    EXPECT_EQ(2U, GetNumQueries(dns, host_name));
+    EXPECT_EQ(ToString(result), "64:ff9b::102:304");
 
     // Stopping NAT64 prefix discovery disables synthesis.
     EXPECT_TRUE(mDnsClient.resolvService()->stopPrefix64Discovery(TEST_NETID).isOk());
     EXPECT_TRUE(WaitForNat64Prefix(EXPECT_NOT_FOUND));
-
     dns.clearQueries();
 
     result = safe_getaddrinfo("v4only", nullptr, &hints);
     EXPECT_TRUE(result != nullptr);
-    // TODO: BUG: there should only be one query, an AAAA (which returns no records), because the
-    // A is already cached. But there is an extra AAAA.
-    EXPECT_EQ(2U, GetNumQueries(dns, host_name));
-
-    result_str = ToString(result);
-    EXPECT_EQ(result_str, "1.2.3.4");
+    // Expect that there is one query, an AAAA (which returns no records), because the
+    // A is already cached.
+    EXPECT_EQ(1U, GetNumQueries(dns, host_name));
+    EXPECT_EQ(ToString(result), "1.2.3.4");
 }
 
 TEST_F(ResolverTest, GetAddrInfo_Dns64QuerySpecified) {
@@ -3120,22 +3117,22 @@ TEST_F(ResolverTest, GetAddrInfo_Dns64QuerySpecified) {
     EXPECT_TRUE(mDnsClient.resolvService()->startPrefix64Discovery(TEST_NETID).isOk());
     EXPECT_TRUE(WaitForNat64Prefix(EXPECT_FOUND));
 
-    // Ensure to synthesize AAAA if AF_INET6 is specified, and not to synthesize AAAA
-    // in AF_INET case.
-    addrinfo hints;
-    memset(&hints, 0, sizeof(hints));
-    hints.ai_family = AF_INET6;
+    // Synthesize AAAA if AF_INET6 is specified and there is A record only. Make sure that A record
+    // is not returned as well.
+    addrinfo hints = {.ai_family = AF_INET6, .ai_socktype = SOCK_DGRAM};
     ScopedAddrinfo result = safe_getaddrinfo("v4only", nullptr, &hints);
     EXPECT_TRUE(result != nullptr);
-    std::string result_str = ToString(result);
-    EXPECT_EQ(result_str, "64:ff9b::102:304");
+    // One for AAAA query without an answer and one for A query which is used for DNS64 synthesis.
+    EXPECT_EQ(2U, GetNumQueries(dns, host_name));
+    EXPECT_EQ(ToString(result), "64:ff9b::102:304");
+    dns.clearQueries();
 
-    hints.ai_family = AF_INET;
+    // Don't synthesize AAAA if AF_INET is specified and there is A record only.
+    hints = {.ai_family = AF_INET, .ai_socktype = SOCK_DGRAM};
     result = safe_getaddrinfo("v4only", nullptr, &hints);
     EXPECT_TRUE(result != nullptr);
-    EXPECT_LE(2U, GetNumQueries(dns, host_name));
-    result_str = ToString(result);
-    EXPECT_EQ(result_str, "1.2.3.4");
+    EXPECT_EQ(0U /*cached in previous queries*/, GetNumQueries(dns, host_name));
+    EXPECT_EQ(ToString(result), "1.2.3.4");
 }
 
 TEST_F(ResolverTest, GetAddrInfo_Dns64QueryUnspecifiedV6) {
@@ -3157,17 +3154,13 @@ TEST_F(ResolverTest, GetAddrInfo_Dns64QueryUnspecifiedV6) {
     EXPECT_TRUE(mDnsClient.resolvService()->startPrefix64Discovery(TEST_NETID).isOk());
     EXPECT_TRUE(WaitForNat64Prefix(EXPECT_FOUND));
 
-    const addrinfo hints = {.ai_family = AF_UNSPEC};
+    const addrinfo hints = {.ai_family = AF_UNSPEC, .ai_socktype = SOCK_DGRAM};
     ScopedAddrinfo result = safe_getaddrinfo("v4v6", nullptr, &hints);
     EXPECT_TRUE(result != nullptr);
-    EXPECT_LE(2U, GetNumQueries(dns, host_name));
+    EXPECT_EQ(2U, GetNumQueries(dns, host_name));
 
-    // In AF_UNSPEC case, do not synthesize AAAA if there's at least one AAAA answer.
-    const std::vector<std::string> result_strs = ToStrings(result);
-    for (const auto& str : result_strs) {
-        EXPECT_TRUE(str == "1.2.3.4" || str == "2001:db8::102:304")
-                << ", result_str='" << str << "'";
-    }
+    // Do not synthesize AAAA if there's at least one AAAA answer.
+    EXPECT_THAT(ToStrings(result), testing::ElementsAre("2001:db8::102:304", "1.2.3.4"));
 }
 
 TEST_F(ResolverTest, GetAddrInfo_Dns64QueryUnspecifiedNoV6) {
@@ -3188,14 +3181,13 @@ TEST_F(ResolverTest, GetAddrInfo_Dns64QueryUnspecifiedNoV6) {
     EXPECT_TRUE(mDnsClient.resolvService()->startPrefix64Discovery(TEST_NETID).isOk());
     EXPECT_TRUE(WaitForNat64Prefix(EXPECT_FOUND));
 
-    const addrinfo hints = {.ai_family = AF_UNSPEC};
+    const addrinfo hints = {.ai_family = AF_UNSPEC, .ai_socktype = SOCK_DGRAM};
     ScopedAddrinfo result = safe_getaddrinfo("v4v6", nullptr, &hints);
     EXPECT_TRUE(result != nullptr);
-    EXPECT_LE(2U, GetNumQueries(dns, host_name));
+    EXPECT_EQ(2U, GetNumQueries(dns, host_name));
 
-    // In AF_UNSPEC case, synthesize AAAA if there's no AAAA answer.
-    std::string result_str = ToString(result);
-    EXPECT_EQ(result_str, "64:ff9b::102:304");
+    // Synthesize AAAA if there's no AAAA answer and AF_UNSPEC is specified.
+    EXPECT_EQ(ToString(result), "64:ff9b::102:304");
 }
 
 TEST_F(ResolverTest, GetAddrInfo_Dns64QuerySpecialUseIPv4Addresses) {
@@ -3245,24 +3237,22 @@ TEST_F(ResolverTest, GetAddrInfo_Dns64QuerySpecialUseIPv4Addresses) {
         const char* host_name = testHostName.c_str();
         dns.addMapping(host_name, ns_type::ns_t_a, config.addr.c_str());
 
-        addrinfo hints;
-        memset(&hints, 0, sizeof(hints));
-        hints.ai_family = AF_INET6;
+        // Expect no result because AF_INET6 is specified and don't synthesize special use IPv4
+        // address.
+        addrinfo hints = {.ai_family = AF_INET6, .ai_socktype = SOCK_DGRAM};
         ScopedAddrinfo result = safe_getaddrinfo(config.name.c_str(), nullptr, &hints);
-        // In AF_INET6 case, don't return IPv4 answers
         EXPECT_TRUE(result == nullptr);
-        EXPECT_LE(2U, GetNumQueries(dns, host_name));
+        EXPECT_EQ(2U, GetNumQueries(dns, host_name));
         dns.clearQueries();
 
-        memset(&hints, 0, sizeof(hints));
-        hints.ai_family = AF_UNSPEC;
+        // Expect special use IPv4 address only because AF_UNSPEC is specified and don't synthesize
+        // special use IPv4 address.
+        hints = {.ai_family = AF_UNSPEC, .ai_socktype = SOCK_DGRAM};
         result = safe_getaddrinfo(config.name.c_str(), nullptr, &hints);
         EXPECT_TRUE(result != nullptr);
         // Expect IPv6 query only. IPv4 answer has been cached in previous query.
-        EXPECT_LE(1U, GetNumQueries(dns, host_name));
-        // In AF_UNSPEC case, don't synthesize special use IPv4 address.
-        std::string result_str = ToString(result);
-        EXPECT_EQ(result_str, config.addr.c_str());
+        EXPECT_EQ(1U, GetNumQueries(dns, host_name));
+        EXPECT_EQ(ToString(result), config.addr);
         dns.clearQueries();
     }
 }
@@ -3288,24 +3278,25 @@ TEST_F(ResolverTest, GetAddrInfo_Dns64QueryWithNullArgumentHints) {
     EXPECT_TRUE(mDnsClient.resolvService()->startPrefix64Discovery(TEST_NETID).isOk());
     EXPECT_TRUE(WaitForNat64Prefix(EXPECT_FOUND));
 
-    // Assign argument hints of getaddrinfo() as null is equivalent to set ai_family AF_UNSPEC.
-    // In AF_UNSPEC case, synthesize AAAA if there has A answer only.
+    // Synthesize AAAA if there is A answer only and AF_UNSPEC (hints NULL) is specified.
+    // Assign argument hints of getaddrinfo() as null is equivalent to set ai_family AF_UNSPEC,
+    // ai_socktype 0 (any), and ai_protocol 0 (any). Note the setting ai_socktype 0 (any) causes
+    // that every address will appear twice, once for SOCK_STREAM and one for SOCK_DGRAM.
+    // See resolv_getaddrinfo in packages/modules/DnsResolver/getaddrinfo.cpp.
     ScopedAddrinfo result = safe_getaddrinfo("v4only", nullptr, nullptr);
     EXPECT_TRUE(result != nullptr);
     EXPECT_LE(2U, GetNumQueries(dns, host_name));
-    std::string result_str = ToString(result);
-    EXPECT_EQ(result_str, "64:ff9b::102:304");
+    EXPECT_EQ(ToString(result), "64:ff9b::102:304");
     dns.clearQueries();
 
-    // In AF_UNSPEC case, do not synthesize AAAA if there's at least one AAAA answer.
+    // Do not synthesize AAAA if there's at least one AAAA answer.
+    // The reason which the addresses appear twice is as mentioned above.
     result = safe_getaddrinfo("v4v6", nullptr, nullptr);
     EXPECT_TRUE(result != nullptr);
     EXPECT_LE(2U, GetNumQueries(dns, host_name2));
-    std::vector<std::string> result_strs = ToStrings(result);
-    for (const auto& str : result_strs) {
-        EXPECT_TRUE(str == "1.2.3.4" || str == "2001:db8::102:304")
-                << ", result_str='" << str << "'";
-    }
+    EXPECT_THAT(ToStrings(result),
+                testing::UnorderedElementsAre("2001:db8::102:304", "2001:db8::102:304", "1.2.3.4",
+                                              "1.2.3.4"));
 }
 
 TEST_F(ResolverTest, GetAddrInfo_Dns64QueryNullArgumentNode) {
@@ -3363,11 +3354,11 @@ TEST_F(ResolverTest, GetAddrInfo_Dns64QueryNullArgumentNode) {
         ASSERT_TRUE(result != nullptr);
 
         // Can't be synthesized because it should not get into Netd.
-        std::vector<std::string> result_strs = ToStrings(result);
-        for (const auto& str : result_strs) {
-            EXPECT_TRUE(str == config.addr_v4 || str == config.addr_v6)
-                    << ", result_str='" << str << "'";
-        }
+        // Every address appears twice, once for SOCK_STREAM and one for SOCK_DGRAM because the
+        // socket type is not specified.
+        EXPECT_THAT(ToStrings(result),
+                    testing::UnorderedElementsAre(config.addr_v4, config.addr_v4, config.addr_v6,
+                                                  config.addr_v6));
 
         // Assign hostname as null and service as numeric port number.
         hints.ai_flags = config.flag | AI_NUMERICSERV;
@@ -3375,11 +3366,10 @@ TEST_F(ResolverTest, GetAddrInfo_Dns64QueryNullArgumentNode) {
         ASSERT_TRUE(result != nullptr);
 
         // Can't be synthesized because it should not get into Netd.
-        result_strs = ToStrings(result);
-        for (const auto& str : result_strs) {
-            EXPECT_TRUE(str == config.addr_v4 || str == config.addr_v6)
-                    << ", result_str='" << str << "'";
-        }
+        // The reason which the addresses appear twice is as mentioned above.
+        EXPECT_THAT(ToStrings(result),
+                    testing::UnorderedElementsAre(config.addr_v4, config.addr_v4, config.addr_v6,
+                                                  config.addr_v6));
     }
 }