src/core/endpoint/socket_utils.c

/*
 *
 * Copyright 2014, Google Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include "src/core/endpoint/socket_utils.h"

#include <limits.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>

/* set a socket to non blocking mode */
int grpc_set_socket_nonblocking(int fd, int non_blocking) {
  int oldflags = fcntl(fd, F_GETFL, 0);
  if (oldflags < 0) {
    return 0;
  }

  if (non_blocking) {
    oldflags |= O_NONBLOCK;
  } else {
    oldflags &= ~O_NONBLOCK;
  }

  if (fcntl(fd, F_SETFL, oldflags) != 0) {
    return 0;
  }

  return 1;
}

/* set a socket to close on exec */
int grpc_set_socket_cloexec(int fd, int close_on_exec) {
  int oldflags = fcntl(fd, F_GETFD, 0);
  if (oldflags < 0) {
    return 0;
  }

  if (close_on_exec) {
    oldflags |= FD_CLOEXEC;
  } else {
    oldflags &= ~FD_CLOEXEC;
  }

  if (fcntl(fd, F_SETFD, oldflags) != 0) {
    return 0;
  }

  return 1;
}

/* set a socket to reuse old addresses */
int grpc_set_socket_reuse_addr(int fd, int reuse) {
  int val = (reuse != 0);
  int newval;
  socklen_t intlen = sizeof(newval);
  return 0 == setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)) &&
         0 == getsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &newval, &intlen) &&
         newval == val;
}

/* disable nagle */
int grpc_set_socket_low_latency(int fd, int low_latency) {
  int val = (low_latency != 0);
  int newval;
  socklen_t intlen = sizeof(newval);
  return 0 == setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &val, sizeof(val)) &&
         0 == getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &newval, &intlen) &&
         newval == val;
}