copy socketpair for win32 from libevent and tor

Summary: Rather than conditionally depending on libevent in a way which is causing downstream conflicts.

Reviewed By: Orvid

Differential Revision: D27121200

fbshipit-source-id: 4c4816e7cb2061718f81cd8a75ce4999b5b32042

folly/net/NetOps.cpp

@@ -22,15 +22,11 @@
 #include <cstddef>
 #include <stdexcept>
 
-#include <folly/Portability.h>
+#include <folly/ScopeGuard.h>
 #include <folly/net/detail/SocketFileDescriptorMap.h>
 
 #ifdef _WIN32
-#include <event2/util.h> // @manual
-
 #include <MSWSock.h> // @manual
-
-#include <folly/ScopeGuard.h>
 #endif
 
 #if !FOLLY_HAVE_RECVMMSG
@@ -545,13 +541,126 @@ NetworkSocket socket(int af, int type, int protocol) {
 #endif
 }
 
+#ifdef _WIN32
+
+//  adapted from like code in libevent, itself adapted from like code in tor
+//
+//  from: https://github.com/libevent/libevent/tree/release-2.1.12-stable
+//  license: 3-Clause BSD
+static int socketpair_win32(
+    int family, int type, int protocol, intptr_t fd[2]) {
+  intptr_t listener = -1;
+  intptr_t connector = -1;
+  intptr_t acceptor = -1;
+  struct sockaddr_in listen_addr;
+  struct sockaddr_in connect_addr;
+  int size;
+  int saved_errno = -1;
+  int family_test;
+
+  family_test = family != AF_INET && (family != AF_UNIX);
+  if (protocol || family_test) {
+    WSASetLastError(WSAEAFNOSUPPORT);
+    return -1;
+  }
+
+  if (!fd) {
+    WSASetLastError(WSAEINVAL);
+    return -1;
+  }
+
+  listener = ::socket(AF_INET, type, 0);
+  if (listener < 0) {
+    return -1;
+  }
+  memset(&listen_addr, 0, sizeof(listen_addr));
+  listen_addr.sin_family = AF_INET;
+  listen_addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+  listen_addr.sin_port = 0; /* kernel chooses port.   */
+  if (::bind(listener, (struct sockaddr*)&listen_addr, sizeof(listen_addr)) ==
+      -1) {
+    goto tidy_up_and_fail;
+  }
+  if (::listen(listener, 1) == -1) {
+    goto tidy_up_and_fail;
+  }
+
+  connector = ::socket(AF_INET, type, 0);
+  if (connector < 0) {
+    goto tidy_up_and_fail;
+  }
+
+  memset(&connect_addr, 0, sizeof(connect_addr));
+
+  /* We want to find out the port number to connect to.  */
+  size = sizeof(connect_addr);
+  if (::getsockname(listener, (struct sockaddr*)&connect_addr, &size) == -1) {
+    goto tidy_up_and_fail;
+  }
+  if (size != sizeof(connect_addr)) {
+    goto abort_tidy_up_and_fail;
+  }
+  if (::connect(
+          connector, (struct sockaddr*)&connect_addr, sizeof(connect_addr)) ==
+      -1) {
+    goto tidy_up_and_fail;
+  }
+
+  size = sizeof(listen_addr);
+  acceptor = ::accept(listener, (struct sockaddr*)&listen_addr, &size);
+  if (acceptor < 0) {
+    goto tidy_up_and_fail;
+  }
+  if (size != sizeof(listen_addr)) {
+    goto abort_tidy_up_and_fail;
+  }
+  /* Now check we are talking to ourself by matching port and host on the
+     two sockets.   */
+  if (::getsockname(connector, (struct sockaddr*)&connect_addr, &size) == -1) {
+    goto tidy_up_and_fail;
+  }
+  if (size != sizeof(connect_addr) ||
+      listen_addr.sin_family != connect_addr.sin_family ||
+      listen_addr.sin_addr.s_addr != connect_addr.sin_addr.s_addr ||
+      listen_addr.sin_port != connect_addr.sin_port) {
+    goto abort_tidy_up_and_fail;
+  }
+  ::closesocket(listener);
+  fd[0] = connector;
+  fd[1] = acceptor;
+
+  return 0;
+
+abort_tidy_up_and_fail:
+  saved_errno = WSAECONNABORTED;
+
+tidy_up_and_fail:
+  if (saved_errno < 0) {
+    saved_errno = WSAGetLastError();
+  }
+  if (listener != -1) {
+    ::closesocket(listener);
+  }
+  if (connector != -1) {
+    ::closesocket(connector);
+  }
+  if (acceptor != -1) {
+    ::closesocket(acceptor);
+  }
+
+  WSASetLastError(saved_errno);
+  return -1;
+}
+
+#endif
+
 int socketpair(int domain, int type, int protocol, NetworkSocket sv[2]) {
 #ifdef _WIN32
   if (domain != PF_UNIX || type != SOCK_STREAM || protocol != 0) {
     return -1;
   }
   intptr_t pair[2];
-  auto r = evutil_socketpair(AF_INET, type, protocol, pair);
+  auto r = socketpair_win32(AF_INET, type, protocol, pair);
   if (r == -1) {
     return r;
   }

folly/net/test/NetOpsTest.cpp

+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * 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 <folly/net/NetOps.h>
+
+#include <glog/logging.h>
+
+#include <folly/net/NetworkSocket.h>
+#include <folly/portability/GTest.h>
+
+class NetOpsTest : public testing::Test {};
+
+TEST_F(NetOpsTest, socketpair) {
+  folly::NetworkSocket pair[2];
+  PCHECK(0 == folly::netops::socketpair(AF_UNIX, SOCK_STREAM, 0, pair));
+  std::string const textw = "hello world";
+  PCHECK(
+      long(textw.size()) ==
+      folly::netops::send(pair[0], textw.data(), textw.size(), 0));
+  std::string textr(100, '\0');
+  PCHECK(
+      long(textw.size()) ==
+      folly::netops::recv(pair[1], &textr[0], textr.size(), 0));
+  textr.resize(textw.size());
+  EXPECT_EQ(textw, textr);
+}