graphene/LibOS/shim/src/sys/shim_dup.c

/* -*- mode:c; c-file-style:"k&r"; c-basic-offset: 4; tab-width:4; indent-tabs-mode:nil; mode:auto-fill; fill-column:78; -*- */
/* vim: set ts=4 sw=4 et tw=78 fo=cqt wm=0: */

/* Copyright (C) 2014 OSCAR lab, Stony Brook University
   This file is part of Graphene Library OS.

   Graphene Library OS is free software: you can redistribute it and/or
   modify it under the terms of the GNU General Public License
   as published by the Free Software Foundation, either version 3 of the
   License, or (at your option) any later version.

   Graphene Library OS 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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

/*
 * shim_clone.c
 *
 * Implementation of system call "dup", "dup2" and "dup3".
 */

#include <shim_internal.h>
#include <shim_table.h>
#include <shim_thread.h>
#include <shim_handle.h>
#include <shim_fs.h>
#include <shim_utils.h>

#include <pal.h>
#include <pal_error.h>

#include <fcntl.h>
#include <errno.h>

int shim_do_dup (int fd)
{
    struct shim_handle_map * handle_map = get_cur_handle_map(NULL);
    int flags = 0;

    struct shim_handle * hdl = get_fd_handle(fd, &flags, handle_map);
    if (!hdl)
        return -EBADF;

    int vfd = set_new_fd_handle(hdl, flags, handle_map);
    put_handle(hdl);
    return vfd < 0 ? -EMFILE : vfd;
}

int shim_do_dup2 (int oldfd, int newfd)
{
    struct shim_handle_map * handle_map = get_cur_handle_map(NULL);

    struct shim_handle * hdl = get_fd_handle(oldfd, NULL, handle_map);
    if (!hdl)
        return -EBADF;

    struct shim_handle * new_hdl = detach_fd_handle(newfd, NULL, handle_map);

    if (new_hdl)
        close_handle(new_hdl);

    int vfd = set_new_fd_handle_by_fd(newfd, hdl, 0, handle_map);
    put_handle(hdl);
    return vfd < 0 ? -EMFILE : vfd;
}

int shim_do_dup3 (int oldfd, int newfd, int flags)
{
    struct shim_handle_map * handle_map = get_cur_handle_map(NULL);
    struct shim_handle * hdl = get_fd_handle(oldfd, NULL, handle_map);
    if (!hdl)
        return -EBADF;

    struct shim_handle * new_hdl = detach_fd_handle(newfd, NULL, handle_map);

    if (new_hdl)
        close_handle(new_hdl);

    int vfd = set_new_fd_handle_by_fd(newfd, hdl, flags, handle_map);
    put_handle(hdl);
    return vfd < 0 ? -EMFILE : vfd;
}