dsh.cpp

/*
 *  Copyright (C) 2023 Savoir-faire Linux Inc.
 *
 *  This program 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.
 *
 *  This program 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 <https://www.gnu.org/licenses/>.
 */
#include "dsh.h"
#include "../common.h"
#include <opendht/log.h>
#include <opendht/crypto.h>

#include <asio/io_context.hpp>
#include <sys/types.h>
#include <sys/wait.h>
namespace dhtnet {

const int READ_END = 0;
const int WRITE_END = 1;

void
create_pipe(int apipe[2])
{
#ifdef __APPLE__
    if (pipe(apipe) < 0)
        perror("pipe");

    if (fcntl(apipe[0], F_SETFD, FD_CLOEXEC) < 0)
        perror("unable to set pipe FD_CLOEXEC");

    if (fcntl(apipe[1], F_SETFD, FD_CLOEXEC) < 0)
        perror("unable to set pipe FD_CLOEXEC");
#else
    if (pipe2(apipe, O_CLOEXEC) == -1) {
        perror("pipe2");
        exit(EXIT_FAILURE);
    }
#endif
}

void
child_proc(const int in_pipe[2],
           const int out_pipe[2],
           const int error_pipe[2],
           const std::string& name)
{
    // close unused write end of input pipe and read end of output pipe
    close(in_pipe[WRITE_END]);
    close(out_pipe[READ_END]);
    close(error_pipe[READ_END]);

    // replace stdin with input pipe
    if (dup2(in_pipe[READ_END], STDIN_FILENO) == -1) {
        perror("dup2: error replacing stdin");
        exit(EXIT_FAILURE);
    }

    // replace stdout with output pipe
    if (dup2(out_pipe[WRITE_END], STDOUT_FILENO) == -1) {
        perror("dup2: error replacing stdout");
        exit(EXIT_FAILURE);