Update network utility getoriginaldst for IPv6 (#3933)

This PR adds IP6T_SO_ORIGINAL_DST to the network utility for retaining the original_dest.

Risk Level:
Medium: Because we have to hardcode this with a define, there is a risk that upstream this gets changed and we would have to adjust. The define is necessary without the unmerged patch from Oct 2016. The TLDR is that the C code does not compile well with our compiler as shown here.

Testing:
Current tests exist

Docs Changes:
In progress

Release Notes:
Support IPv6 for original_dest in network utility

Fixes #1094

Signed-off-by: Christopher M. Luciano <cmluciano@us.ibm.com>

source/common/network/BUILD

@@ -226,6 +226,7 @@ envoy_cc_library(
         ":address_lib",
         "//include/envoy/network:connection_interface",
         "//include/envoy/stats:stats_interface",
+        "//source/common/api:os_sys_calls_lib",
         "//source/common/common:assert_lib",
         "//source/common/common:utility_lib",
         "//source/common/protobuf",

source/common/network/utility.cc

@@ -7,6 +7,11 @@
 #include <linux/netfilter_ipv4.h>
 #endif
 
+#ifndef IP6T_SO_ORIGINAL_DST
+// From linux/netfilter_ipv6/ip6_tables.h
+#define IP6T_SO_ORIGINAL_DST 80
+#endif
+
 #include <netinet/ip.h>
 #include <sys/socket.h>
 
@@ -20,6 +25,7 @@
 #include "envoy/network/connection.h"
 #include "envoy/stats/stats.h"
 
+#include "common/api/os_sys_calls_impl.h"
 #include "common/common/assert.h"
 #include "common/common/utility.h"
 #include "common/network/address_impl.h"
@@ -292,14 +298,35 @@ Address::InstanceConstSharedPtr Utility::getOriginalDst(int fd) {
 #ifdef SOL_IP
   sockaddr_storage orig_addr;
   socklen_t addr_len = sizeof(sockaddr_storage);
-  int status = getsockopt(fd, SOL_IP, SO_ORIGINAL_DST, &orig_addr, &addr_len);
+  int socket_domain;
+  socklen_t domain_len = sizeof(socket_domain);
+  auto& os_syscalls = Api::OsSysCallsSingleton::get();
+  int status = os_syscalls.getsockopt(fd, SOL_SOCKET, SO_DOMAIN, &socket_domain, &domain_len);
+
+  if (status != 0) {
+    return nullptr;
+  }
 
-  if (status == 0) {
-    // TODO(mattklein123): IPv6 support. See github issue #1094.
-    ASSERT(orig_addr.ss_family == AF_INET);
+  if (socket_domain == AF_INET) {
+    status = os_syscalls.getsockopt(fd, SOL_IP, SO_ORIGINAL_DST, &orig_addr, &addr_len);
+  } else if (socket_domain == AF_INET6) {
+    status = os_syscalls.getsockopt(fd, SOL_IPV6, IP6T_SO_ORIGINAL_DST, &orig_addr, &addr_len);
+  } else {
+    return nullptr;
+  }
+
+  if (status != 0) {
+    return nullptr;
+  }
+
+  switch (orig_addr.ss_family) {
+  case AF_INET:
     return Address::InstanceConstSharedPtr{
         new Address::Ipv4Instance(reinterpret_cast<sockaddr_in*>(&orig_addr))};
-  } else {
+  case AF_INET6:
+    return Address::InstanceConstSharedPtr{
+        new Address::Ipv6Instance(reinterpret_cast<sockaddr_in6&>(orig_addr))};
+  default:
     return nullptr;
   }
 #else

test/server/listener_manager_impl_test.cc

@@ -2269,6 +2269,143 @@ TEST_F(ListenerManagerImplWithRealFiltersTest, OriginalDstTestFilterOptionFail)
   EXPECT_EQ(0U, manager_->listeners().size());
 }
 
+class OriginalDstTestFilterIPv6
+    : public Extensions::ListenerFilters::OriginalDst::OriginalDstFilter {
+  Network::Address::InstanceConstSharedPtr getOriginalDst(int) override {
+    return Network::Address::InstanceConstSharedPtr{
+        new Network::Address::Ipv6Instance("1::2", 2345)};
+  }
+};
+
+TEST_F(ListenerManagerImplWithRealFiltersTest, OriginalDstTestFilterIPv6) {
+  static int fd;
+  fd = -1;
+  EXPECT_CALL(*listener_factory_.socket_, fd()).WillOnce(Return(0));
+
+  class OriginalDstTestConfigFactory : public Configuration::NamedListenerFilterConfigFactory {
+  public:
+    // NamedListenerFilterConfigFactory
+    Network::ListenerFilterFactoryCb
+    createFilterFactoryFromProto(const Protobuf::Message&,
+                                 Configuration::ListenerFactoryContext& context) override {
+      auto option = std::make_unique<Network::MockSocketOption>();
+      EXPECT_CALL(*option, setOption(_, envoy::api::v2::core::SocketOption::STATE_PREBIND))
+          .WillOnce(Return(true));
+      EXPECT_CALL(*option, setOption(_, envoy::api::v2::core::SocketOption::STATE_BOUND))
+          .WillOnce(Invoke(
+              [](Network::Socket& socket, envoy::api::v2::core::SocketOption::SocketState) -> bool {
+                fd = socket.fd();
+                return true;
+              }));
+      context.addListenSocketOption(std::move(option));
+      return [](Network::ListenerFilterManager& filter_manager) -> void {
+        filter_manager.addAcceptFilter(std::make_unique<OriginalDstTestFilterIPv6>());
+      };
+    }
+
+    ProtobufTypes::MessagePtr createEmptyConfigProto() override {
+      return std::make_unique<Envoy::ProtobufWkt::Empty>();
+    }
+
+    std::string name() override { return "test.listener.original_dstipv6"; }
+  };
+
+  /**
+   * Static registration for the original dst filter. @see RegisterFactory.
+   */
+  static Registry::RegisterFactory<OriginalDstTestConfigFactory,
+                                   Configuration::NamedListenerFilterConfigFactory>
+      registered_;
+
+  const std::string yaml = TestEnvironment::substitute(R"EOF(
+    address:
+      socket_address: { address: ::0001, port_value: 1111 }
+    filter_chains: {}
+    listener_filters:
+    - name: "test.listener.original_dstipv6"
+      config: {}
+  )EOF",
+                                                       Network::Address::IpVersion::v6);
+
+  EXPECT_CALL(server_.random_, uuid());
+  EXPECT_CALL(listener_factory_, createListenSocket(_, _, true));
+  manager_->addOrUpdateListener(parseListenerFromV2Yaml(yaml), "", true);
+  EXPECT_EQ(1U, manager_->listeners().size());
+
+  Network::ListenerConfig& listener = manager_->listeners().back().get();
+
+  Network::FilterChainFactory& filterChainFactory = listener.filterChainFactory();
+  Network::MockListenerFilterManager manager;
+
+  NiceMock<Network::MockListenerFilterCallbacks> callbacks;
+  Network::AcceptedSocketImpl socket(
+      -1, std::make_unique<Network::Address::Ipv6Instance>("::0001", 1234),
+      std::make_unique<Network::Address::Ipv6Instance>("::0001", 5678));
+
+  EXPECT_CALL(callbacks, socket()).WillOnce(Invoke([&]() -> Network::ConnectionSocket& {
+    return socket;
+  }));
+
+  EXPECT_CALL(manager, addAcceptFilter_(_))
+      .WillOnce(Invoke([&](Network::ListenerFilterPtr& filter) -> void {
+        EXPECT_EQ(Network::FilterStatus::Continue, filter->onAccept(callbacks));
+      }));
+
+  EXPECT_TRUE(filterChainFactory.createListenerFilterChain(manager));
+  EXPECT_TRUE(socket.localAddressRestored());
+  EXPECT_EQ("[1::2]:2345", socket.localAddress()->asString());
+  EXPECT_NE(fd, -1);
+}
+
+TEST_F(ListenerManagerImplWithRealFiltersTest, OriginalDstTestFilterOptionFailIPv6) {
+  class OriginalDstTestConfigFactory : public Configuration::NamedListenerFilterConfigFactory {
+  public:
+    // NamedListenerFilterConfigFactory
+    Network::ListenerFilterFactoryCb
+    createFilterFactoryFromProto(const Protobuf::Message&,
+                                 Configuration::ListenerFactoryContext& context) override {
+      auto option = std::make_unique<Network::MockSocketOption>();
+      EXPECT_CALL(*option, setOption(_, envoy::api::v2::core::SocketOption::STATE_PREBIND))
+          .WillOnce(Return(false));
+      context.addListenSocketOption(std::move(option));
+      return [](Network::ListenerFilterManager& filter_manager) -> void {
+        filter_manager.addAcceptFilter(std::make_unique<OriginalDstTestFilterIPv6>());
+      };
+    }
+
+    ProtobufTypes::MessagePtr createEmptyConfigProto() override {
+      return std::make_unique<Envoy::ProtobufWkt::Empty>();
+    }
+
+    std::string name() override { return "testfail.listener.original_dstipv6"; }
+  };
+
+  /**
+   * Static registration for the original dst filter. @see RegisterFactory.
+   */
+  static Registry::RegisterFactory<OriginalDstTestConfigFactory,
+                                   Configuration::NamedListenerFilterConfigFactory>
+      registered_;
+
+  const std::string yaml = TestEnvironment::substitute(R"EOF(
+    name: "socketOptionFailListener"
+    address:
+      socket_address: { address: ::0001, port_value: 1111 }
+    filter_chains: {}
+    listener_filters:
+    - name: "testfail.listener.original_dstipv6"
+      config: {}
+  )EOF",
+                                                       Network::Address::IpVersion::v6);
+
+  EXPECT_CALL(listener_factory_, createListenSocket(_, _, true));
+
+  EXPECT_THROW_WITH_MESSAGE(manager_->addOrUpdateListener(parseListenerFromV2Yaml(yaml), "", true),
+                            EnvoyException,
+                            "MockListenerComponentFactory: Setting socket options failed");
+  EXPECT_EQ(0U, manager_->listeners().size());
+}
+
 // Validate that when neither transparent nor freebind is not set in the
 // Listener, we see no socket option set.
 TEST_F(ListenerManagerImplWithRealFiltersTest, TransparentFreebindListenerDisabled) {