text: /*
   *
   * 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 "src/core/lib/iomgr/port.h"
  
  #include <inttypes.h>
  
  #ifdef GRPC_WINSOCK_SOCKET
  
  #include "src/core/lib/iomgr/sockaddr_windows.h"
  
  #include <grpc/slice_buffer.h>
  #include <grpc/support/alloc.h>
  #include <grpc/support/log.h>
  #include <grpc/support/log_windows.h>
  
  #include "src/core/lib/channel/channel_args.h"
  #include "src/core/lib/iomgr/iocp_windows.h"
  #include "src/core/lib/iomgr/sockaddr.h"
  #include "src/core/lib/iomgr/sockaddr_utils.h"
  #include "src/core/lib/iomgr/socket_windows.h"
  #include "src/core/lib/iomgr/tcp_client.h"
  #include "src/core/lib/iomgr/tcp_windows.h"
  #include "src/core/lib/iomgr/timer.h"
  
  typedef struct {
    grpc_closure* on_done;
    gpr_mu mu;
    grpc_winsocket* socket;
    grpc_timer alarm;
    grpc_closure on_alarm;
    char* addr_name;
    int refs;
    grpc_closure on_connect;
    grpc_endpoint** endpoint;
    grpc_channel_args* channel_args;
  } async_connect;
  
  static void async_connect_unlock_and_cleanup(async_connect* ac,
                                               grpc_winsocket* socket) {
    int done = (--ac->refs == 0);
    gpr_mu_unlock(&ac->mu);
    if (done) {
      grpc_channel_args_destroy(ac->channel_args);
      gpr_mu_destroy(&ac->mu);
      gpr_free(ac->addr_name);
      gpr_free(ac);
    }
    if (socket != NULL) grpc_winsocket_destroy(socket);
  }
  
  static void on_alarm(void* acp, grpc_error* error) {
    async_connect* ac = (async_connect*)acp;
    gpr_mu_lock(&ac->mu);
    grpc_winsocket* socket = ac->socket;
    ac->socket = NULL;
    if (socket != NULL) {
      grpc_winsocket_shutdown(socket);
    }
    async_connect_unlock_and_cleanup(ac, socket);
  }
  
  static void on_connect(void* acp, grpc_error* error) {
    async_connect* ac = (async_connect*)acp;
    grpc_endpoint** ep = ac->endpoint;
    GPR_ASSERT(*ep == NULL);
    grpc_closure* on_done = ac->on_done;
  
    GRPC_ERROR_REF(error);
  
    gpr_mu_lock(&ac->mu);
    grpc_winsocket* socket = ac->socket;
    ac->socket = NULL;
    gpr_mu_unlock(&ac->mu);
  
    grpc_timer_cancel(&ac->alarm);
  
    gpr_mu_lock(&ac->mu);
  
    if (error == GRPC_ERROR_NONE) {
      if (socket != NULL) {
        DWORD transfered_bytes = 0;
        DWORD flags;
        BOOL wsa_success =
            WSAGetOverlappedResult(socket->socket, &socket->write_info.overlapped,
                                   &transfered_bytes, FALSE, &flags);
        GPR_ASSERT(transfered_bytes == 0);
        if (!wsa_success) {
          error = GRPC_WSA_ERROR(WSAGetLastError(), "ConnectEx");
          closesocket(socket->socket);
        } else {
          *ep = grpc_tcp_create(socket, ac->channel_args, ac->addr_name);
          socket = NULL;
        }
      } else {
        error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("socket is null");
      }
    }
  
    async_connect_unlock_and_cleanup(ac, socket);
    /* If the connection was aborted, the callback was already called when
       the deadline was met. */
    GRPC_CLOSURE_SCHED(on_done, error);
  }
  
  /* Tries to issue one async connection, then schedules both an IOCP
     notification request for the connection, and one timeout alert. */
  static void tcp_client_connect_impl(grpc_closure* on_done,
                                      grpc_endpoint** endpoint,
                                      grpc_pollset_set* interested_parties,
                                      const grpc_channel_args* channel_args,
                                      const grpc_resolved_address* addr,
                                      grpc_millis deadline) {
    SOCKET sock = INVALID_SOCKET;
    BOOL success;
    int status;
    grpc_resolved_address addr6_v4mapped;
    grpc_resolved_address local_address;
    async_connect* ac;
    grpc_winsocket* socket = NULL;
    LPFN_CONNECTEX ConnectEx;
    GUID guid = WSAID_CONNECTEX;
    DWORD ioctl_num_bytes;
    grpc_winsocket_callback_info* info;
    grpc_error* error = GRPC_ERROR_NONE;
  
    *endpoint = NULL;
  
    /* Use dualstack sockets where available. */
    if (grpc_sockaddr_to_v4mapped(addr, &addr6_v4mapped)) {
      addr = &addr6_v4mapped;
    }
  
    sock = WSASocket(AF_INET6, SOCK_STREAM, IPPROTO_TCP, NULL, 0,
                     WSA_FLAG_OVERLAPPED);
    if (sock == INVALID_SOCKET) {
      error = GRPC_WSA_ERROR(WSAGetLastError(), "WSASocket");
      goto failure;
    }
  
    error = grpc_tcp_prepare_socket(sock);
    if (error != GRPC_ERROR_NONE) {
      goto failure;
    }
  
    /* Grab the function pointer for ConnectEx for that specific socket.
       It may change depending on the interface. */
    status =
        WSAIoctl(sock, SIO_GET_EXTENSION_FUNCTION_POINTER, &guid, sizeof(guid),
                 &ConnectEx, sizeof(ConnectEx), &ioctl_num_bytes, NULL, NULL);
  
    if (status != 0) {
      error = GRPC_WSA_ERROR(WSAGetLastError(),
                             "WSAIoctl(SIO_GET_EXTENSION_FUNCTION_POINTER)");
      goto failure;
    }
  
    grpc_sockaddr_make_wildcard6(0, &local_address);
  
    status =
        bind(sock, (struct sockaddr*)&local_address.addr, (int)local_address.len);
    if (status != 0) {
      error = GRPC_WSA_ERROR(WSAGetLastError(), "bind");
      goto failure;
    }
  
    socket = grpc_winsocket_create(sock, "client");
    info = &socket->write_info;
    success = ConnectEx(sock, (struct sockaddr*)&addr->addr, (int)addr->len, NULL,
                        0, NULL, &info->overlapped);
  
    /* It wouldn't be unusual to get a success immediately. But we'll still get
       an IOCP notification, so let's ignore it. */
    if (!success) {
      int last_error = WSAGetLastError();
      if (last_error != ERROR_IO_PENDING) {
        error = GRPC_WSA_ERROR(last_error, "ConnectEx");
        goto failure;
      }
    }
  
    ac = (async_connect*)gpr_malloc(sizeof(async_connect));
    ac->on_done = on_done;
    ac->socket = socket;
    gpr_mu_init(&ac->mu);
    ac->refs = 2;
    ac->addr_name = grpc_sockaddr_to_uri(addr);
    ac->endpoint = endpoint;
    ac->channel_args = grpc_channel_args_copy(channel_args);
    GRPC_CLOSURE_INIT(&ac->on_connect, on_connect, ac, grpc_schedule_on_exec_ctx);
  
    GRPC_CLOSURE_INIT(&ac->on_alarm, on_alarm, ac, grpc_schedule_on_exec_ctx);
    grpc_timer_init(&ac->alarm, deadline, &ac->on_alarm);
    grpc_socket_notify_on_write(socket, &ac->on_connect);
    return;
  
  failure:
    GPR_ASSERT(error != GRPC_ERROR_NONE);
    char* target_uri = grpc_sockaddr_to_uri(addr);
    grpc_error* final_error = grpc_error_set_str(
        GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING("Failed to connect",
                                                         &error, 1),
        GRPC_ERROR_STR_TARGET_ADDRESS, grpc_slice_from_copied_string(target_uri));
    GRPC_ERROR_UNREF(error);
    if (socket != NULL) {
      grpc_winsocket_destroy(socket);
    } else if (sock != INVALID_SOCKET) {
      closesocket(sock);
    }
    GRPC_CLOSURE_SCHED(on_done, final_error);
  }
  
  // overridden by api_fuzzer.c
  void (*grpc_tcp_client_connect_impl)(
      grpc_closure* closure, grpc_endpoint** ep,
      grpc_pollset_set* interested_parties, const grpc_channel_args* channel_args,
      const grpc_resolved_address* addr,
      grpc_millis deadline) = tcp_client_connect_impl;
  
  void grpc_tcp_client_connect(grpc_closure* closure, grpc_endpoint** ep,
                               grpc_pollset_set* interested_parties,
                               const grpc_channel_args* channel_args,
                               const grpc_resolved_address* addr,
                               grpc_millis deadline) {
    grpc_tcp_client_connect_impl(closure, ep, interested_parties, channel_args,
                                 addr, deadline);
  }
  
  #endif /* GRPC_WINSOCK_SOCKET */
  