port.cc

/*  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
 *
 *  Data Differential YATL (i.e. libtest)  library
 *
 *  Copyright (C) 2012 Data Differential, http://datadifferential.com/
 *
 *  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.
 *
 *      * The names of its contributors may not 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
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 *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 */

#include "libtest/yatlcon.h"
#include <libtest/common.h>

#include <cassert>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <fnmatch.h>
#include <iostream>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h> 
#include <sys/wait.h>
#include <unistd.h>

#include <utility>
#include <vector>

#include <signal.h>

#include <libtest/signal.h>

#ifndef SOCK_CLOEXEC 
#  define SOCK_CLOEXEC 0
#endif

#ifndef SOCK_NONBLOCK 
#  define SOCK_NONBLOCK 0
#endif

#ifndef FD_CLOEXEC
#  define FD_CLOEXEC 0
#endif

#ifndef __INTEL_COMPILER
#pragma GCC diagnostic ignored "-Wold-style-cast"
#endif

using namespace libtest;

struct socket_st {
  typedef std::vector< std::pair< int, in_port_t> > socket_port_t;
  socket_port_t _pair;
  in_port_t last_port;

  socket_st():
    last_port(0)
  { }

  void release(in_port_t _arg)
  {
    for (socket_port_t::iterator iter= _pair.begin();
         iter != _pair.end();
         ++iter)
    {
      if ((*iter).second == _arg)
      {
        shutdown((*iter).first, SHUT_RDWR);
        close((*iter).first);
      }
    }
  }

  ~socket_st()
  {
    for (socket_port_t::iterator iter= _pair.begin();
         iter != _pair.end();
         ++iter)
    {
      shutdown((*iter).first, SHUT_RDWR);
      close((*iter).first);
    }
  }
};

static socket_st all_socket_fd;

static in_port_t global_port= 0;

static void initialize_default_port()
{
  global_port= get_free_port();
}

static pthread_once_t default_port_once= PTHREAD_ONCE_INIT;

namespace libtest {

in_port_t default_port()
{
  {
    int ret;
    if ((ret= pthread_once(&default_port_once, initialize_default_port)) != 0)
    {
      FATAL(strerror(ret));
    }
  }

  return global_port;
}

void release_port(in_port_t arg)
{
  all_socket_fd.release(arg);
}

in_port_t get_free_port()
{
  const in_port_t default_port= in_port_t(-1);

  int retries= 1024;

  in_port_t ret_port;
  while (--retries)
  {
    ret_port= default_port;
    int sd;
    if ((sd= socket(AF_INET, SOCK_STREAM, 0)) != SOCKET_ERROR)
    {
      int optval= 1;
      if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof(optval)) != SOCKET_ERROR)
      { 
        struct sockaddr_in sin;
        sin.sin_port= 0;
        sin.sin_addr.s_addr= INADDR_ANY;
        sin.sin_family= AF_INET;

        int bind_ret;
        do
        {
          if ((bind_ret= bind(sd, (struct sockaddr *)&sin, sizeof(struct sockaddr_in) )) != SOCKET_ERROR)
          {
            socklen_t addrlen= sizeof(sin);

            if (getsockname(sd, (struct sockaddr *)&sin, &addrlen) != -1)
            {
              ret_port= sin.sin_port;
            }
          }
          else
          {
            if (errno != EADDRINUSE)
            {
              Error << strerror(errno);
            }
          }

          if (errno == EADDRINUSE)
          {
            libtest::dream(2, 0);
          }
        } while (bind_ret == -1 and errno == EADDRINUSE);

        all_socket_fd._pair.push_back(std::make_pair(sd, ret_port));
      }
      else
      {
        Error << strerror(errno);
      }
    }
    else
    {
      Error << strerror(errno);
    }

    if (ret_port == default_port)
    {
      Error << "no ret_port set:" << strerror(errno);
    }
    else if (ret_port > 1024 and ret_port != all_socket_fd.last_port)
    {
      break;
    }
  }

  // We handle the case where if we max out retries, we still abort.
  if (retries == 0)
  {
    FATAL("No port could be found, exhausted retry");
  }

  if (ret_port == 0)
  {
    FATAL("No port could be found");
  }

  if (ret_port == default_port)
  {
    FATAL("No port could be found");
  }

  if (ret_port <= 1024)
  {
    FATAL("No port could be found, though some where available below or at 1024");
  }

  all_socket_fd.last_port= ret_port;
  release_port(ret_port);

  return ret_port;
}

} // namespace libtest