Revert "Fix shutdown of closed fd when c-ares opens a second fd"

4 files changed, 4 insertions, 432 deletions

diff --git a/test/cpp/naming/BUILD b/test/cpp/naming/BUILD
index 2925e8fbcf..fa0b216f8f 100644
--- a/test/cpp/naming/BUILD
+++ b/test/cpp/naming/BUILD
@@ -22,7 +22,7 @@ package(
 
 licenses(["notice"])  # Apache v2
 
-load("//bazel:grpc_build_system.bzl", "grpc_py_binary", "grpc_cc_test")
+load("//bazel:grpc_build_system.bzl", "grpc_py_binary")
 
 load(":generate_resolver_component_tests.bzl", "generate_resolver_component_tests")
 
@@ -35,20 +35,4 @@ grpc_py_binary(
     testonly = True,
 )
 
-grpc_cc_test(
-    name = "cancel_ares_query_test",
-    srcs = ["cancel_ares_query_test.cc"],
-    external_deps = ["gmock"],
-    deps = [
-        "//test/cpp/util:test_util",
-        "//test/core/util:grpc_test_util",
-        "//test/core/util:gpr_test_util",
-        "//:grpc++",
-        "//:grpc",
-        "//:gpr",
-        "//test/cpp/util:test_config",
-        "//test/core/end2end:cq_verifier",
-    ],
-)
-
 generate_resolver_component_tests()
diff --git a/test/cpp/naming/cancel_ares_query_test.cc b/test/cpp/naming/cancel_ares_query_test.cc
deleted file mode 100644
index 11cdc0b774..0000000000
--- a/test/cpp/naming/cancel_ares_query_test.cc
+++ /dev/null
@@ -1,289 +0,0 @@
-/*
- *
- * Copyright 2015 gRPC 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 <string.h>
-
-#include <gflags/gflags.h>
-#include <gmock/gmock.h>
-
-#include <grpc/byte_buffer.h>
-#include <grpc/grpc.h>
-#include <grpc/support/alloc.h>
-#include <grpc/support/log.h>
-#include <grpc/support/time.h>
-#include "include/grpc/support/string_util.h"
-#include "src/core/ext/filters/client_channel/resolver.h"
-#include "src/core/ext/filters/client_channel/resolver_registry.h"
-#include "src/core/lib/channel/channel_args.h"
-#include "src/core/lib/debug/stats.h"
-#include "src/core/lib/gpr/env.h"
-#include "src/core/lib/gpr/host_port.h"
-#include "src/core/lib/gpr/string.h"
-#include "src/core/lib/gprpp/orphanable.h"
-#include "src/core/lib/gprpp/thd.h"
-#include "src/core/lib/iomgr/combiner.h"
-#include "src/core/lib/iomgr/pollset.h"
-#include "src/core/lib/iomgr/pollset_set.h"
-#include "test/core/end2end/cq_verifier.h"
-#include "test/core/util/cmdline.h"
-#include "test/core/util/port.h"
-#include "test/core/util/test_config.h"
-
-// TODO: pull in different headers when enabling this
-// test on windows. Also set BAD_SOCKET_RETURN_VAL
-// to INVALID_SOCKET on windows.
-#include "src/core/lib/iomgr/sockaddr_posix.h"
-#define BAD_SOCKET_RETURN_VAL -1
-
-namespace {
-
-void* Tag(intptr_t t) { return (void*)t; }
-
-gpr_timespec FiveSecondsFromNow(void) {
-  return grpc_timeout_seconds_to_deadline(5);
-}
-
-void DrainCq(grpc_completion_queue* cq) {
-  grpc_event ev;
-  do {
-    ev = grpc_completion_queue_next(cq, FiveSecondsFromNow(), nullptr);
-  } while (ev.type != GRPC_QUEUE_SHUTDOWN);
-}
-
-void EndTest(grpc_channel* client, grpc_completion_queue* cq) {
-  grpc_channel_destroy(client);
-  grpc_completion_queue_shutdown(cq);
-  DrainCq(cq);
-  grpc_completion_queue_destroy(cq);
-}
-
-class FakeNonResponsiveDNSServer {
- public:
-  FakeNonResponsiveDNSServer(int port) {
-    socket_ = socket(AF_INET6, SOCK_DGRAM, 0);
-    if (socket_ == BAD_SOCKET_RETURN_VAL) {
-      gpr_log(GPR_DEBUG, "Failed to create UDP ipv6 socket");
-      abort();
-    }
-    sockaddr_in6 addr;
-    memset(&addr, 0, sizeof(addr));
-    addr.sin6_family = AF_INET6;
-    addr.sin6_port = htons(port);
-    ((char*)&addr.sin6_addr)[15] = 1;
-    if (bind(socket_, (const sockaddr*)&addr, sizeof(addr)) != 0) {
-      gpr_log(GPR_DEBUG, "Failed to bind UDP ipv6 socket to [::1]:%d", port);
-      abort();
-    }
-  }
-  ~FakeNonResponsiveDNSServer() { close(socket_); }
-
- private:
-  int socket_;
-};
-
-struct ArgsStruct {
-  gpr_atm done_atm;
-  gpr_mu* mu;
-  grpc_pollset* pollset;
-  grpc_pollset_set* pollset_set;
-  grpc_combiner* lock;
-  grpc_channel_args* channel_args;
-};
-
-void ArgsInit(ArgsStruct* args) {
-  args->pollset = (grpc_pollset*)gpr_zalloc(grpc_pollset_size());
-  grpc_pollset_init(args->pollset, &args->mu);
-  args->pollset_set = grpc_pollset_set_create();
-  grpc_pollset_set_add_pollset(args->pollset_set, args->pollset);
-  args->lock = grpc_combiner_create();
-  gpr_atm_rel_store(&args->done_atm, 0);
-  args->channel_args = nullptr;
-}
-
-void DoNothing(void* arg, grpc_error* error) {}
-
-void ArgsFinish(ArgsStruct* args) {
-  grpc_pollset_set_del_pollset(args->pollset_set, args->pollset);
-  grpc_pollset_set_destroy(args->pollset_set);
-  grpc_closure DoNothing_cb;
-  GRPC_CLOSURE_INIT(&DoNothing_cb, DoNothing, nullptr,
-                    grpc_schedule_on_exec_ctx);
-  grpc_pollset_shutdown(args->pollset, &DoNothing_cb);
-  // exec_ctx needs to be flushed before calling grpc_pollset_destroy()
-  grpc_channel_args_destroy(args->channel_args);
-  grpc_core::ExecCtx::Get()->Flush();
-  grpc_pollset_destroy(args->pollset);
-  gpr_free(args->pollset);
-  GRPC_COMBINER_UNREF(args->lock, nullptr);
-}
-
-void PollPollsetUntilRequestDone(ArgsStruct* args) {
-  while (true) {
-    bool done = gpr_atm_acq_load(&args->done_atm) != 0;
-    if (done) {
-      break;
-    }
-    grpc_pollset_worker* worker = nullptr;
-    grpc_core::ExecCtx exec_ctx;
-    gpr_mu_lock(args->mu);
-    GRPC_LOG_IF_ERROR(
-        "pollset_work",
-        grpc_pollset_work(args->pollset, &worker,
-                          grpc_timespec_to_millis_round_up(
-                              gpr_inf_future(GPR_CLOCK_REALTIME))));
-    gpr_mu_unlock(args->mu);
-  }
-}
-
-void CheckResolverResultAssertFailureLocked(void* arg, grpc_error* error) {
-  EXPECT_NE(error, GRPC_ERROR_NONE);
-  ArgsStruct* args = static_cast<ArgsStruct*>(arg);
-  gpr_atm_rel_store(&args->done_atm, 1);
-  gpr_mu_lock(args->mu);
-  GRPC_LOG_IF_ERROR("pollset_kick", grpc_pollset_kick(args->pollset, nullptr));
-  gpr_mu_unlock(args->mu);
-}
-
-TEST(CancelDuringAresQuery, TestCancelActiveDNSQuery) {
-  grpc_core::ExecCtx exec_ctx;
-  ArgsStruct args;
-  ArgsInit(&args);
-  int fake_dns_port = grpc_pick_unused_port_or_die();
-  FakeNonResponsiveDNSServer fake_dns_server(fake_dns_port);
-  char* client_target;
-  GPR_ASSERT(gpr_asprintf(
-      &client_target,
-      "dns://[::1]:%d/dont-care-since-wont-be-resolved.test.com:1234",
-      fake_dns_port));
-  // create resolver and resolve
-  grpc_core::OrphanablePtr<grpc_core::Resolver> resolver =
-      grpc_core::ResolverRegistry::CreateResolver(client_target, nullptr,
-                                                  args.pollset_set, args.lock);
-  gpr_free(client_target);
-  grpc_closure on_resolver_result_changed;
-  GRPC_CLOSURE_INIT(&on_resolver_result_changed,
-                    CheckResolverResultAssertFailureLocked, (void*)&args,
-                    grpc_combiner_scheduler(args.lock));
-  resolver->NextLocked(&args.channel_args, &on_resolver_result_changed);
-  // Without resetting and causing resolver shutdown, the
-  // PollPollsetUntilRequestDone call should never finish.
-  resolver.reset();
-  grpc_core::ExecCtx::Get()->Flush();
-  PollPollsetUntilRequestDone(&args);
-  ArgsFinish(&args);
-}
-
-TEST(CancelDuringAresQuery,
-     TestHitDeadlineAndDestroyChannelDuringAresResolutionIsGraceful) {
-  // Start up fake non responsive DNS server
-  int fake_dns_port = grpc_pick_unused_port_or_die();
-  FakeNonResponsiveDNSServer fake_dns_server(fake_dns_port);
-  // Create a call that will try to use the fake DNS server
-  char* client_target = nullptr;
-  GPR_ASSERT(gpr_asprintf(
-      &client_target,
-      "dns://[::1]:%d/dont-care-since-wont-be-resolved.test.com:1234",
-      fake_dns_port));
-  grpc_channel* client =
-      grpc_insecure_channel_create(client_target,
-                                   /* client_args */ nullptr, nullptr);
-  gpr_free(client_target);
-  grpc_completion_queue* cq = grpc_completion_queue_create_for_next(nullptr);
-  cq_verifier* cqv = cq_verifier_create(cq);
-  gpr_timespec deadline = grpc_timeout_milliseconds_to_deadline(10);
-  grpc_call* call = grpc_channel_create_call(
-      client, nullptr, GRPC_PROPAGATE_DEFAULTS, cq,
-      grpc_slice_from_static_string("/foo"), nullptr, deadline, nullptr);
-  GPR_ASSERT(call);
-  grpc_metadata_array initial_metadata_recv;
-  grpc_metadata_array trailing_metadata_recv;
-  grpc_metadata_array request_metadata_recv;
-  grpc_metadata_array_init(&initial_metadata_recv);
-  grpc_metadata_array_init(&trailing_metadata_recv);
-  grpc_metadata_array_init(&request_metadata_recv);
-  grpc_call_details call_details;
-  grpc_call_details_init(&call_details);
-  grpc_status_code status;
-  const char* error_string;
-  grpc_slice details;
-  // Set ops for client the request
-  grpc_op ops_base[6];
-  memset(ops_base, 0, sizeof(ops_base));
-  grpc_op* op = ops_base;
-  op->op = GRPC_OP_SEND_INITIAL_METADATA;
-  op->data.send_initial_metadata.count = 0;
-  op->flags = 0;
-  op->reserved = nullptr;
-  op++;
-  op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
-  op->flags = 0;
-  op->reserved = nullptr;
-  op++;
-  op->op = GRPC_OP_RECV_INITIAL_METADATA;
-  op->data.recv_initial_metadata.recv_initial_metadata = &initial_metadata_recv;
-  op->flags = 0;
-  op->reserved = nullptr;
-  op++;
-  op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
-  op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
-  op->data.recv_status_on_client.status = &status;
-  op->data.recv_status_on_client.status_details = &details;
-  op->data.recv_status_on_client.error_string = &error_string;
-  op->flags = 0;
-  op->reserved = nullptr;
-  op++;
-  // Run the call and sanity check it failed as expected
-  grpc_call_error error = grpc_call_start_batch(
-      call, ops_base, static_cast<size_t>(op - ops_base), Tag(1), nullptr);
-  EXPECT_EQ(GRPC_CALL_OK, error);
-  CQ_EXPECT_COMPLETION(cqv, Tag(1), 1);
-  cq_verify(cqv);
-  EXPECT_EQ(status, GRPC_STATUS_DEADLINE_EXCEEDED);
-  // Teardown
-  grpc_slice_unref(details);
-  gpr_free((void*)error_string);
-  grpc_metadata_array_destroy(&initial_metadata_recv);
-  grpc_metadata_array_destroy(&trailing_metadata_recv);
-  grpc_metadata_array_destroy(&request_metadata_recv);
-  grpc_call_details_destroy(&call_details);
-  grpc_call_unref(call);
-  cq_verifier_destroy(cqv);
-  EndTest(client, cq);
-}
-
-}  // namespace
-
-int main(int argc, char** argv) {
-  grpc_test_init(argc, argv);
-  ::testing::InitGoogleTest(&argc, argv);
-  gpr_setenv("GRPC_DNS_RESOLVER", "ares");
-  // Sanity check the time that it takes to run the test
-  // including the teardown time (the teardown
-  // part of the test involves cancelling the DNS query,
-  // which is the main point of interest for this test).
-  gpr_timespec overall_deadline = grpc_timeout_seconds_to_deadline(4);
-  grpc_init();
-  auto result = RUN_ALL_TESTS();
-  grpc_shutdown();
-  if (gpr_time_cmp(gpr_now(GPR_CLOCK_MONOTONIC), overall_deadline) > 0) {
-    gpr_log(GPR_ERROR, "Test took too long");
-    abort();
-  }
-  return result;
-}
diff --git a/test/cpp/naming/gen_build_yaml.py b/test/cpp/naming/gen_build_yaml.py
index eb2c01e7ad..6e63cbe483 100755
--- a/test/cpp/naming/gen_build_yaml.py
+++ b/test/cpp/naming/gen_build_yaml.py
@@ -120,25 +120,6 @@ def main():
                   'grpc++_test_config',
               ],
           } for unsecure_build_config_suffix in ['_unsecure', '']
-      ] + [
-          {
-          'name': 'cancel_ares_query_test',
-          'build': 'test',
-          'language': 'c++',
-          'gtest': True,
-          'run': True,
-          'src': ['test/cpp/naming/cancel_ares_query_test.cc'],
-          'platforms': ['linux', 'posix', 'mac'],
-          'deps': [
-              'grpc++_test_util',
-              'grpc_test_util',
-              'gpr_test_util',
-              'grpc++',
-              'grpc',
-              'gpr',
-              'grpc++_test_config',
-          ],
-          },
       ]
   }
 
diff --git a/test/cpp/naming/resolver_component_test.cc b/test/cpp/naming/resolver_component_test.cc
index 649441d4fa..f4be064305 100644
--- a/test/cpp/naming/resolver_component_test.cc
+++ b/test/cpp/naming/resolver_component_test.cc
@@ -22,14 +22,10 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/sync.h>
 #include <grpc/support/time.h>
-
 #include <string.h>
 
-#include <errno.h>
-#include <fcntl.h>
 #include <gflags/gflags.h>
 #include <gmock/gmock.h>
-#include <thread>
 #include <vector>
 
 #include "test/cpp/util/subprocess.h"
@@ -52,12 +48,6 @@
 #include "test/core/util/port.h"
 #include "test/core/util/test_config.h"
 
-// TODO: pull in different headers when enabling this
-// test on windows. Also set BAD_SOCKET_RETURN_VAL
-// to INVALID_SOCKET on windows.
-#include "src/core/lib/iomgr/sockaddr_posix.h"
-#define BAD_SOCKET_RETURN_VAL -1
-
 using grpc::SubProcess;
 using std::vector;
 using testing::UnorderedElementsAreArray;
@@ -241,73 +231,7 @@ void CheckLBPolicyResultLocked(grpc_channel_args* channel_args,
   }
 }
 
-void OpenAndCloseSocketsStressLoop(int dummy_port, gpr_event* done_ev) {
-  // The goal of this loop is to catch socket
-  // "use after close" bugs within the c-ares resolver by acting
-  // like some separate thread doing I/O.
-  // It's goal is to try to hit race conditions whereby:
-  //    1) The c-ares resolver closes a socket.
-  //    2) This loop opens a socket with (coincidentally) the same handle.
-  //    3) the c-ares resolver mistakenly uses that same socket without
-  //       realizing that its closed.
-  //    4) This loop performs an operation on that socket that should
-  //       succeed but instead fails because of what the c-ares
-  //       resolver did in the meantime.
-  sockaddr_in6 addr;
-  memset(&addr, 0, sizeof(addr));
-  addr.sin6_family = AF_INET6;
-  addr.sin6_port = htons(dummy_port);
-  ((char*)&addr.sin6_addr)[15] = 1;
-  for (;;) {
-    if (gpr_event_get(done_ev)) {
-      return;
-    }
-    std::vector<int> sockets;
-    // First open a bunch of sockets, bind and listen
-    // '50' is an arbitrary number that, experimentally,
-    // has a good chance of catching bugs.
-    for (size_t i = 0; i < 50; i++) {
-      int s = socket(AF_INET6, SOCK_STREAM, 0);
-      int val = 1;
-      setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &val, sizeof(val));
-      fcntl(s, F_SETFL, O_NONBLOCK);
-      ASSERT_TRUE(s != BAD_SOCKET_RETURN_VAL)
-          << "Failed to create TCP ipv6 socket";
-      gpr_log(GPR_DEBUG, "Opened fd: %d", s);
-      ASSERT_TRUE(bind(s, (const sockaddr*)&addr, sizeof(addr)) == 0)
-          << "Failed to bind socket " + std::to_string(s) +
-                 " to [::1]:" + std::to_string(dummy_port) +
-                 ". errno: " + std::to_string(errno);
-      ASSERT_TRUE(listen(s, 1) == 0) << "Failed to listen on socket " +
-                                            std::to_string(s) +
-                                            ". errno: " + std::to_string(errno);
-      sockets.push_back(s);
-    }
-    // Do a non-blocking accept followed by a close on all of those sockets.
-    // Do this in a separate loop to try to induce a time window to hit races.
-    for (size_t i = 0; i < sockets.size(); i++) {
-      gpr_log(GPR_DEBUG, "non-blocking accept then close on %d", sockets[i]);
-      if (accept(sockets[i], nullptr, nullptr)) {
-        // If e.g. a "shutdown" was called on this fd from another thread,
-        // then this accept call should fail with an unexpected error.
-        ASSERT_TRUE(errno == EAGAIN || errno == EWOULDBLOCK)
-            << "OpenAndCloseSocketsStressLoop accept on socket " +
-                   std::to_string(sockets[i]) +
-                   " failed in "
-                   "an unexpected way. "
-                   "errno: " +
-                   std::to_string(errno) +
-                   ". Socket use-after-close bugs are likely.";
-      }
-      ASSERT_TRUE(close(sockets[i]) == 0)
-          << "Failed to close socket: " + std::to_string(sockets[i]) +
-                 ". errno: " + std::to_string(errno);
-    }
-  }
-}
-
 void CheckResolverResultLocked(void* argsp, grpc_error* err) {
-  EXPECT_EQ(err, GRPC_ERROR_NONE);
   ArgsStruct* args = (ArgsStruct*)argsp;
   grpc_channel_args* channel_args = args->channel_args;
   const grpc_arg* channel_arg =
@@ -347,17 +271,7 @@ void CheckResolverResultLocked(void* argsp, grpc_error* err) {
   gpr_mu_unlock(args->mu);
 }
 
-void CheckResolvedWithoutErrorLocked(void* argsp, grpc_error* err) {
-  EXPECT_EQ(err, GRPC_ERROR_NONE);
-  ArgsStruct* args = (ArgsStruct*)argsp;
-  gpr_atm_rel_store(&args->done_atm, 1);
-  gpr_mu_lock(args->mu);
-  GRPC_LOG_IF_ERROR("pollset_kick", grpc_pollset_kick(args->pollset, nullptr));
-  gpr_mu_unlock(args->mu);
-}
-
-void RunResolvesRelevantRecordsTest(void (*OnDoneLocked)(void* arg,
-                                                         grpc_error* error)) {
+TEST(ResolverComponentTest, TestResolvesRelevantRecords) {
   grpc_core::ExecCtx exec_ctx;
   ArgsStruct args;
   ArgsInit(&args);
@@ -375,32 +289,14 @@ void RunResolvesRelevantRecordsTest(void (*OnDoneLocked)(void* arg,
                                                   args.pollset_set, args.lock);
   gpr_free(whole_uri);
   grpc_closure on_resolver_result_changed;
-  GRPC_CLOSURE_INIT(&on_resolver_result_changed, OnDoneLocked, (void*)&args,
-                    grpc_combiner_scheduler(args.lock));
+  GRPC_CLOSURE_INIT(&on_resolver_result_changed, CheckResolverResultLocked,
+                    (void*)&args, grpc_combiner_scheduler(args.lock));
   resolver->NextLocked(&args.channel_args, &on_resolver_result_changed);
   grpc_core::ExecCtx::Get()->Flush();
   PollPollsetUntilRequestDone(&args);
   ArgsFinish(&args);
 }
 
-TEST(ResolverComponentTest, TestResolvesRelevantRecords) {
-  RunResolvesRelevantRecordsTest(CheckResolverResultLocked);
-}
-
-TEST(ResolverComponentTest, TestResolvesRelevantRecordsWithConcurrentFdStress) {
-  // Start up background stress thread
-  int dummy_port = grpc_pick_unused_port_or_die();
-  gpr_event done_ev;
-  gpr_event_init(&done_ev);
-  std::thread socket_stress_thread(OpenAndCloseSocketsStressLoop, dummy_port,
-                                   &done_ev);
-  // Run the resolver test
-  RunResolvesRelevantRecordsTest(CheckResolvedWithoutErrorLocked);
-  // Shutdown and join stress thread
-  gpr_event_set(&done_ev, (void*)1);
-  socket_stress_thread.join();
-}
-
 }  // namespace
 
 int main(int argc, char** argv) {