Add socket connection stress test.

Tests 65k connection attempts on common types of sockets to check for port
leaks.

Also fixes a bug where dual-stack sockets wouldn't properly re-queue
segments received while closing.

PiperOrigin-RevId: 293241166

8 files changed, 251 insertions, 11 deletions

diff --git a/pkg/tcpip/transport/tcp/connect.go b/pkg/tcpip/transport/tcp/connect.go
index 9ff7ac261..5c5397823 100644
--- a/pkg/tcpip/transport/tcp/connect.go
+++ b/pkg/tcpip/transport/tcp/connect.go
@@ -989,6 +989,10 @@ func (e *endpoint) transitionToStateCloseLocked() {
 // to any other listening endpoint. We reply with RST if we cannot find one.
 func (e *endpoint) tryDeliverSegmentFromClosedEndpoint(s *segment) {
 	ep := e.stack.FindTransportEndpoint(e.NetProto, e.TransProto, e.ID, &s.route)
+	if ep == nil && e.NetProto == header.IPv6ProtocolNumber && e.EndpointInfo.TransportEndpointInfo.ID.LocalAddress.To4() != "" {
+		// Dual-stack socket, try IPv4.
+		ep = e.stack.FindTransportEndpoint(header.IPv4ProtocolNumber, e.TransProto, e.ID, &s.route)
+	}
 	if ep == nil {
 		replyWithReset(s)
 		s.decRef()
diff --git a/test/syscalls/BUILD b/test/syscalls/BUILD
index 8f2b75a1c..31d239c0e 100644
--- a/test/syscalls/BUILD
+++ b/test/syscalls/BUILD
@@ -46,6 +46,15 @@ syscall_test(test = "//test/syscalls/linux:brk_test")
 syscall_test(test = "//test/syscalls/linux:socket_test")
 
 syscall_test(
+    size = "large",
+    shard_count = 50,
+    # Takes too long for TSAN. Since this is kind of a stress test that doesn't
+    # involve much concurrency, TSAN's usefulness here is limited anyway.
+    tags = ["nogotsan"],
+    test = "//test/syscalls/linux:socket_stress_test",
+)
+
+syscall_test(
     add_overlay = True,
     test = "//test/syscalls/linux:chdir_test",
 )
diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD
index 737e2329f..273b014d6 100644
--- a/test/syscalls/linux/BUILD
+++ b/test/syscalls/linux/BUILD
@@ -136,6 +136,7 @@ cc_library(
         "@com_google_absl//absl/strings",
         "@com_google_absl//absl/strings:str_format",
         "@com_google_absl//absl/time",
+        "@com_google_absl//absl/types:optional",
         "//test/util:file_descriptor",
         "//test/util:posix_error",
         "//test/util:temp_path",
@@ -2151,6 +2152,22 @@ cc_library(
     alwayslink = 1,
 )
 
+cc_binary(
+    name = "socket_stress_test",
+    testonly = 1,
+    srcs = [
+        "socket_generic_stress.cc",
+    ],
+    linkstatic = 1,
+    deps = [
+        ":ip_socket_test_util",
+        ":socket_test_util",
+        gtest,
+        "//test/util:test_main",
+        "//test/util:test_util",
+    ],
+)
+
 cc_library(
     name = "socket_unix_dgram_test_cases",
     testonly = 1,
diff --git a/test/syscalls/linux/ip_socket_test_util.cc b/test/syscalls/linux/ip_socket_test_util.cc
index 6b472eb2f..bba022a41 100644
--- a/test/syscalls/linux/ip_socket_test_util.cc
+++ b/test/syscalls/linux/ip_socket_test_util.cc
@@ -79,6 +79,33 @@ SocketPairKind DualStackTCPAcceptBindSocketPair(int type) {
                                      /* dual_stack = */ true)};
 }
 
+SocketPairKind IPv6TCPAcceptBindPersistentListenerSocketPair(int type) {
+  std::string description =
+      absl::StrCat(DescribeSocketType(type), "connected IPv6 TCP socket");
+  return SocketPairKind{description, AF_INET6, type | SOCK_STREAM, IPPROTO_TCP,
+                        TCPAcceptBindPersistentListenerSocketPairCreator(
+                            AF_INET6, type | SOCK_STREAM, 0,
+                            /* dual_stack = */ false)};
+}
+
+SocketPairKind IPv4TCPAcceptBindPersistentListenerSocketPair(int type) {
+  std::string description =
+      absl::StrCat(DescribeSocketType(type), "connected IPv4 TCP socket");
+  return SocketPairKind{description, AF_INET, type | SOCK_STREAM, IPPROTO_TCP,
+                        TCPAcceptBindPersistentListenerSocketPairCreator(
+                            AF_INET, type | SOCK_STREAM, 0,
+                            /* dual_stack = */ false)};
+}
+
+SocketPairKind DualStackTCPAcceptBindPersistentListenerSocketPair(int type) {
+  std::string description =
+      absl::StrCat(DescribeSocketType(type), "connected dual stack TCP socket");
+  return SocketPairKind{description, AF_INET6, type | SOCK_STREAM, IPPROTO_TCP,
+                        TCPAcceptBindPersistentListenerSocketPairCreator(
+                            AF_INET6, type | SOCK_STREAM, 0,
+                            /* dual_stack = */ true)};
+}
+
 SocketPairKind IPv6UDPBidirectionalBindSocketPair(int type) {
   std::string description =
       absl::StrCat(DescribeSocketType(type), "connected IPv6 UDP socket");
diff --git a/test/syscalls/linux/ip_socket_test_util.h b/test/syscalls/linux/ip_socket_test_util.h
index 0f58e0f77..083ebbcf0 100644
--- a/test/syscalls/linux/ip_socket_test_util.h
+++ b/test/syscalls/linux/ip_socket_test_util.h
@@ -50,6 +50,21 @@ SocketPairKind IPv4TCPAcceptBindSocketPair(int type);
 // given type bound to the IPv4 loopback.
 SocketPairKind DualStackTCPAcceptBindSocketPair(int type);
 
+// IPv6TCPAcceptBindPersistentListenerSocketPair is like
+// IPv6TCPAcceptBindSocketPair except it uses a persistent listening socket to
+// create all socket pairs.
+SocketPairKind IPv6TCPAcceptBindPersistentListenerSocketPair(int type);
+
+// IPv4TCPAcceptBindPersistentListenerSocketPair is like
+// IPv4TCPAcceptBindSocketPair except it uses a persistent listening socket to
+// create all socket pairs.
+SocketPairKind IPv4TCPAcceptBindPersistentListenerSocketPair(int type);
+
+// DualStackTCPAcceptBindPersistentListenerSocketPair is like
+// DualStackTCPAcceptBindSocketPair except it uses a persistent listening socket
+// to create all socket pairs.
+SocketPairKind DualStackTCPAcceptBindPersistentListenerSocketPair(int type);
+
 // IPv6UDPBidirectionalBindSocketPair returns a SocketPairKind that represents
 // SocketPairs created with bind() and connect() syscalls with AF_INET6 and the
 // given type bound to the IPv6 loopback.
diff --git a/test/syscalls/linux/socket_generic_stress.cc b/test/syscalls/linux/socket_generic_stress.cc
new file mode 100644
index 000000000..6a232238d
--- /dev/null
+++ b/test/syscalls/linux/socket_generic_stress.cc
@@ -0,0 +1,83 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <stdio.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#include "gtest/gtest.h"
+#include "test/syscalls/linux/ip_socket_test_util.h"
+#include "test/syscalls/linux/socket_test_util.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+// Test fixture for tests that apply to pairs of connected sockets.
+using ConnectStressTest = SocketPairTest;
+
+TEST_P(ConnectStressTest, Reset65kTimes) {
+  for (int i = 0; i < 1 << 16; ++i) {
+    auto sockets = ASSERT_NO_ERRNO_AND_VALUE(NewSocketPair());
+
+    // Send some data to ensure that the connection gets reset and the port gets
+    // released immediately. This avoids either end entering TIME-WAIT.
+    char sent_data[100] = {};
+    ASSERT_THAT(write(sockets->first_fd(), sent_data, sizeof(sent_data)),
+                SyscallSucceedsWithValue(sizeof(sent_data)));
+  }
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    AllConnectedSockets, ConnectStressTest,
+    ::testing::Values(IPv6UDPBidirectionalBindSocketPair(0),
+                      IPv4UDPBidirectionalBindSocketPair(0),
+                      DualStackUDPBidirectionalBindSocketPair(0),
+
+                      // Without REUSEADDR, we get port exhaustion on Linux.
+                      SetSockOpt(SOL_SOCKET, SO_REUSEADDR,
+                                 &kSockOptOn)(IPv6TCPAcceptBindSocketPair(0)),
+                      SetSockOpt(SOL_SOCKET, SO_REUSEADDR,
+                                 &kSockOptOn)(IPv4TCPAcceptBindSocketPair(0)),
+                      SetSockOpt(SOL_SOCKET, SO_REUSEADDR, &kSockOptOn)(
+                          DualStackTCPAcceptBindSocketPair(0))));
+
+// Test fixture for tests that apply to pairs of connected sockets created with
+// a persistent listener (if applicable).
+using PersistentListenerConnectStressTest = SocketPairTest;
+
+TEST_P(PersistentListenerConnectStressTest, 65kTimes) {
+  for (int i = 0; i < 1 << 16; ++i) {
+    auto sockets = ASSERT_NO_ERRNO_AND_VALUE(NewSocketPair());
+  }
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    AllConnectedSockets, PersistentListenerConnectStressTest,
+    ::testing::Values(
+        IPv6UDPBidirectionalBindSocketPair(0),
+        IPv4UDPBidirectionalBindSocketPair(0),
+        DualStackUDPBidirectionalBindSocketPair(0),
+
+        // Without REUSEADDR, we get port exhaustion on Linux.
+        SetSockOpt(SOL_SOCKET, SO_REUSEADDR, &kSockOptOn)(
+            IPv6TCPAcceptBindPersistentListenerSocketPair(0)),
+        SetSockOpt(SOL_SOCKET, SO_REUSEADDR, &kSockOptOn)(
+            IPv4TCPAcceptBindPersistentListenerSocketPair(0)),
+        SetSockOpt(SOL_SOCKET, SO_REUSEADDR, &kSockOptOn)(
+            DualStackTCPAcceptBindPersistentListenerSocketPair(0))));
+
+}  // namespace testing
+}  // namespace gvisor
diff --git a/test/syscalls/linux/socket_test_util.cc b/test/syscalls/linux/socket_test_util.cc
index eff7d577e..c0c5ab3fe 100644
--- a/test/syscalls/linux/socket_test_util.cc
+++ b/test/syscalls/linux/socket_test_util.cc
@@ -18,10 +18,13 @@
 #include <poll.h>
 #include <sys/socket.h>
 
+#include <memory>
+
 #include "gtest/gtest.h"
 #include "absl/memory/memory.h"
 #include "absl/strings/str_cat.h"
 #include "absl/time/clock.h"
+#include "absl/types/optional.h"
 #include "test/util/file_descriptor.h"
 #include "test/util/posix_error.h"
 #include "test/util/temp_path.h"
@@ -109,7 +112,10 @@ Creator<SocketPair> AcceptBindSocketPairCreator(bool abstract, int domain,
       MaybeSave();  // Unlinked path.
     }
 
-    return absl::make_unique<AddrFDSocketPair>(connected, accepted, bind_addr,
+    // accepted is before connected to destruct connected before accepted.
+    // Destructors for nonstatic member objects are called in the reverse order
+    // in which they appear in the class declaration.
+    return absl::make_unique<AddrFDSocketPair>(accepted, connected, bind_addr,
                                                extra_addr);
   };
 }
@@ -311,11 +317,16 @@ PosixErrorOr<T> BindIP(int fd, bool dual_stack) {
 }
 
 template <typename T>
-PosixErrorOr<std::unique_ptr<AddrFDSocketPair>> CreateTCPAcceptBindSocketPair(
-    int bound, int connected, int type, bool dual_stack) {
-  ASSIGN_OR_RETURN_ERRNO(T bind_addr, BindIP<T>(bound, dual_stack));
-  RETURN_ERROR_IF_SYSCALL_FAIL(listen(bound, /* backlog = */ 5));
+PosixErrorOr<T> TCPBindAndListen(int fd, bool dual_stack) {
+  ASSIGN_OR_RETURN_ERRNO(T addr, BindIP<T>(fd, dual_stack));
+  RETURN_ERROR_IF_SYSCALL_FAIL(listen(fd, /* backlog = */ 5));
+  return addr;
+}
 
+template <typename T>
+PosixErrorOr<std::unique_ptr<AddrFDSocketPair>>
+CreateTCPConnectAcceptSocketPair(int bound, int connected, int type,
+                                 bool dual_stack, T bind_addr) {
   int connect_result = 0;
   RETURN_ERROR_IF_SYSCALL_FAIL(
       (connect_result = RetryEINTR(connect)(
@@ -358,16 +369,27 @@ PosixErrorOr<std::unique_ptr<AddrFDSocketPair>> CreateTCPAcceptBindSocketPair(
     absl::SleepFor(absl::Seconds(1));
   }
 
-  // Cleanup no longer needed resources.
-  RETURN_ERROR_IF_SYSCALL_FAIL(close(bound));
-  MaybeSave();  // Successful close.
-
   T extra_addr = {};
   LocalhostAddr(&extra_addr, dual_stack);
   return absl::make_unique<AddrFDSocketPair>(connected, accepted, bind_addr,
                                              extra_addr);
 }
 
+template <typename T>
+PosixErrorOr<std::unique_ptr<AddrFDSocketPair>> CreateTCPAcceptBindSocketPair(
+    int bound, int connected, int type, bool dual_stack) {
+  ASSIGN_OR_RETURN_ERRNO(T bind_addr, TCPBindAndListen<T>(bound, dual_stack));
+
+  auto result = CreateTCPConnectAcceptSocketPair(bound, connected, type,
+                                                 dual_stack, bind_addr);
+
+  // Cleanup no longer needed resources.
+  RETURN_ERROR_IF_SYSCALL_FAIL(close(bound));
+  MaybeSave();  // Successful close.
+
+  return result;
+}
+
 Creator<SocketPair> TCPAcceptBindSocketPairCreator(int domain, int type,
                                                    int protocol,
                                                    bool dual_stack) {
@@ -389,6 +411,63 @@ Creator<SocketPair> TCPAcceptBindSocketPairCreator(int domain, int type,
   };
 }
 
+Creator<SocketPair> TCPAcceptBindPersistentListenerSocketPairCreator(
+    int domain, int type, int protocol, bool dual_stack) {
+  // These are lazily initialized below, on the first call to the returned
+  // lambda. These values are private to each returned lambda, but shared across
+  // invocations of a specific lambda.
+  //
+  // The sharing allows pairs created with the same parameters to share a
+  // listener. This prevents future connects from failing if the connecting
+  // socket selects a port which had previously been used by a listening socket
+  // that still has some connections in TIME-WAIT.
+  //
+  // The lazy initialization is to avoid creating sockets during parameter
+  // enumeration. This is important because parameters are enumerated during the
+  // build process where networking may not be available.
+  auto listener = std::make_shared<absl::optional<int>>(absl::optional<int>());
+  auto addr4 = std::make_shared<absl::optional<sockaddr_in>>(
+      absl::optional<sockaddr_in>());
+  auto addr6 = std::make_shared<absl::optional<sockaddr_in6>>(
+      absl::optional<sockaddr_in6>());
+
+  return [=]() -> PosixErrorOr<std::unique_ptr<AddrFDSocketPair>> {
+    int connected;
+    RETURN_ERROR_IF_SYSCALL_FAIL(connected = socket(domain, type, protocol));
+    MaybeSave();  // Successful socket creation.
+
+    // Share the listener across invocations.
+    if (!listener->has_value()) {
+      int fd = socket(domain, type, protocol);
+      if (fd < 0) {
+        return PosixError(errno, absl::StrCat("socket(", domain, ", ", type,
+                                              ", ", protocol, ")"));
+      }
+      listener->emplace(fd);
+      MaybeSave();  // Successful socket creation.
+    }
+
+    // Bind the listener once, but create a new connect/accept pair each
+    // time.
+    if (domain == AF_INET) {
+      if (!addr4->has_value()) {
+        addr4->emplace(
+            TCPBindAndListen<sockaddr_in>(listener->value(), dual_stack)
+                .ValueOrDie());
+      }
+      return CreateTCPConnectAcceptSocketPair(listener->value(), connected,
+                                              type, dual_stack, addr4->value());
+    }
+    if (!addr6->has_value()) {
+      addr6->emplace(
+          TCPBindAndListen<sockaddr_in6>(listener->value(), dual_stack)
+              .ValueOrDie());
+    }
+    return CreateTCPConnectAcceptSocketPair(listener->value(), connected, type,
+                                            dual_stack, addr6->value());
+  };
+}
+
 template <typename T>
 PosixErrorOr<std::unique_ptr<AddrFDSocketPair>> CreateUDPBoundSocketPair(
     int sock1, int sock2, int type, bool dual_stack) {
@@ -518,8 +597,8 @@ size_t CalculateUnixSockAddrLen(const char* sun_path) {
   if (sun_path[0] == 0) {
     return sizeof(sockaddr_un);
   }
-  // Filesystem addresses use the address length plus the 2 byte sun_family and
-  // null terminator.
+  // Filesystem addresses use the address length plus the 2 byte sun_family
+  // and null terminator.
   return strlen(sun_path) + 3;
 }
 
diff --git a/test/syscalls/linux/socket_test_util.h b/test/syscalls/linux/socket_test_util.h
index 2dbb8bed3..bfaa6e397 100644
--- a/test/syscalls/linux/socket_test_util.h
+++ b/test/syscalls/linux/socket_test_util.h
@@ -273,6 +273,12 @@ Creator<SocketPair> TCPAcceptBindSocketPairCreator(int domain, int type,
                                                    int protocol,
                                                    bool dual_stack);
 
+// TCPAcceptBindPersistentListenerSocketPairCreator is like
+// TCPAcceptBindSocketPairCreator, except it uses the same listening socket to
+// create all SocketPairs.
+Creator<SocketPair> TCPAcceptBindPersistentListenerSocketPairCreator(
+    int domain, int type, int protocol, bool dual_stack);
+
 // UDPBidirectionalBindSocketPairCreator returns a Creator<SocketPair> that
 // obtains file descriptors by invoking the bind() and connect() syscalls on UDP
 // sockets.