/*

  Copyright 2008 Nathan Phillip Brink, Ethan Zonca

  This file is a part of DistRen.

  DistRen is free software: you can redistribute it and/or modify

  it under the terms of the GNU Affero General Public License as published by

  the Free Software Foundation, either version 3 of the License, or

  (at your option) any later version.

  DistRen is distributed in the hope that it will be useful,

  but WITHOUT ANY WARRANTY; without even the implied warranty of

  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  GNU Affero General Public License for more details.

  You should have received a copy of the GNU Affero General Public License

  along with DistRen.  If not, see <http://www.gnu.org/licenses/>.

*/

#include "execio.h"

#include <unistd.h>

#include <sys/types.h>

#include <sys/wait.h>

#include <signal.h>

#include <malloc.h>

#include <stdio.h>

int execio_open(struct execio **rem, const char *progname, char *const argv[])

{

  /* pipe used to write to child */

  int pipe_write[2];

  /* pipe used to read from child */

  int pipe_read[2];

  pid_t child;

  /* for wait(2) if needed */

  int childstatus;

  int counter;

  int counter2;

  /* create two pipes to facilitate communication with child */

  if(pipe(pipe_write))

    return 1;

  /* parent */

  child = fork();

  if(child == -1)

    {

      close(pipe_write[0]);

      close(pipe_write[1]);

      close(pipe_read[0]);

      close(pipe_read[1]);

      return 1;

    }

  if(child)

    {

      /* close sides of pipe we won't use */

      close(pipe_write[0]);

      close(pipe_read[1]);

      /* setup execio struct */

      (*rem) = malloc(sizeof(struct execio));

      if(!(*rem))

	{

	  /* we should tell the child we're dead - use wait and close our end of the pipes! */

	  close(pipe_write[1]);

	  close(pipe_read[0]);

	  /* we should probably pass of the wait() call to a thread that just does boring things like that. Especially for when the server tries to connect to other servers... */

	  /* maybe we should just kill the child */

	  kill(child, SIGTERM);

	  /* the waitpid(2) seems to indicate that only when the child is terminated will this wait return. */

	  waitpid(child, &childstatus, 0); 

	}

      (*rem)->pipe_write = pipe_write[1];

      (*rem)->pipe_read = pipe_read[0];

      (*rem)->child = child;

      return 0;

    }

  /* child */

  else

    {

      /* close unused pipes */

      close(pipe_write[1]);

      close(pipe_read[0]);

      /*

	reset stdin, stdout, and stderr to the appropriate files. OK, not stderr :-) 

      */

      dup2(pipe_read[1], 0);