// Copyright 2010, Shuo Chen.  All rights reserved.
// http://code.google.com/p/muduo/
//
// Use of this source code is governed by a BSD-style license
// that can be found in the License file.

// Author: Shuo Chen (chenshuo at chenshuo dot com)

#include "SocketsOps.h"
#include "logging/Logging.h"

#include <errno.h>
#include <fcntl.h>
#include <stdio.h>  // snprintf
#include <strings.h>  // bzero
#include <sys/socket.h>
#include <unistd.h>

using namespace muduo;

namespace
{

typedef struct sockaddr SA;

const SA* sockaddr_cast(const struct sockaddr_in* addr)
{
  return static_cast<const SA*>(implicit_cast<const void*>(addr));
}

SA* sockaddr_cast(struct sockaddr_in* addr)
{
  return static_cast<SA*>(implicit_cast<void*>(addr));
}

void setNonBlockAndCloseOnExec(int sockfd)
{
  // non-block
  int flags = ::fcntl(sockfd, F_GETFL, 0);
  flags |= O_NONBLOCK;
  int ret = ::fcntl(sockfd, F_SETFL, flags);
  // FIXME check

  // close-on-exec
  flags = ::fcntl(sockfd, F_GETFD, 0);
  flags |= FD_CLOEXEC;
  ret = ::fcntl(sockfd, F_SETFD, flags);
  // FIXME check
}

}

int sockets::createNonblockingOrDie()
{
  // socket
#if VALGRIND
  int sockfd = ::socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
  if (sockfd < 0)
  {
    LOG_SYSFATAL << "sockets::createNonblockingOrDie";
  }

  setNonBlockAndCloseOnExec(sockfd);
#else
  int sockfd = ::socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, IPPROTO_TCP);
  if (sockfd < 0)
  {
    LOG_SYSFATAL << "sockets::createNonblockingOrDie";
  }
#endif
  return sockfd;
}

void sockets::bindOrDie(int sockfd, const struct sockaddr_in& addr)
{
  int ret = ::bind(sockfd, sockaddr_cast(&addr), sizeof addr);
  if (ret < 0)
  {
    LOG_SYSFATAL << "sockets::bindOrDie";
  }
}

void sockets::listenOrDie(int sockfd)
{
  int ret = ::listen(sockfd, SOMAXCONN);
  if (ret < 0)
  {
    LOG_SYSFATAL << "sockets::listenOrDie";
  }
}

int sockets::accept(int sockfd, struct sockaddr_in* addr)
{
  socklen_t addrlen = sizeof *addr;
#if VALGRIND
  int connfd = ::accept(sockfd, sockaddr_cast(addr), &addrlen);
  setNonBlockAndCloseOnExec(connfd);
#else
  int connfd = ::accept4(sockfd, sockaddr_cast(addr),
                         &addrlen, SOCK_NONBLOCK | SOCK_CLOEXEC);
#endif
  if (connfd < 0)
  {
    int savedErrno = errno;
    LOG_SYSERR << "Socket::accept";
    switch (savedErrno)
    {
      case EAGAIN:
      case ECONNABORTED:
      case EINTR:
      case EPROTO: // ???
      case EPERM:
      case EMFILE: // per-process lmit of open file desctiptor ???
        // expected errors
        errno = savedErrno;
        break;
      case EBADF:
      case EFAULT:
      case EINVAL:
      case ENFILE:
      case ENOBUFS:
      case ENOMEM:
      case ENOTSOCK:
      case EOPNOTSUPP:
        // unexpected errors
        LOG_FATAL << "unexpected error of ::accept " << savedErrno;
        break;
      default:
        LOG_FATAL << "unknown error of ::accept " << savedErrno;
        break;
    }
  }
  return connfd;
}

void sockets::close(int sockfd)
{
  if (::close(sockfd) < 0)
  {
    LOG_SYSERR << "sockets::close";
  }
}

void sockets::toHostPort(char* buf, size_t size,
                         const struct sockaddr_in& addr)
{
  char host[INET_ADDRSTRLEN] = "INVALID";
  ::inet_ntop(AF_INET, &addr.sin_addr, host, sizeof host);
  uint16_t port = sockets::networkToHost16(addr.sin_port);
  snprintf(buf, size, "%s:%u", host, port);
}

void sockets::fromHostPort(const char* ip, uint16_t port,
                           struct sockaddr_in* addr)
{
  addr->sin_family = AF_INET;
  addr->sin_port = hostToNetwork16(port);
  if (::inet_pton(AF_INET, ip, &addr->sin_addr) <= 0)
  {
    LOG_SYSERR << "sockets::fromHostPort";
  }
}

struct sockaddr_in sockets::getLocalAddr(int sockfd)
{
  struct sockaddr_in localaddr;
  bzero(&localaddr, sizeof localaddr);
  socklen_t addrlen = sizeof(localaddr);
  if (::getsockname(sockfd, sockaddr_cast(&localaddr), &addrlen) < 0)
  {
    LOG_SYSERR << "sockets::getLocalAddr";
  }
  return localaddr;
}

int sockets::getSocketError(int sockfd)
{
  int optval;
  socklen_t optlen = sizeof optval;

  if (::getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, &optlen) < 0)
  {
    return errno;
  }
  else
  {
    return optval;
  }
}