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/* uroot - User's root
* main.c Source file with main function
*
* Copyright (C) 2018-2019 Karel Kočí
*
* 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 2
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sched.h>
#include <unistd.h>
#include <stdint.h>
#include <stdbool.h>
#include <argp.h>
#include <string.h>
#include "child.h"
#include "utils.h"
#include "sigpipe.h"
#include "conf.h"
const char *argp_program_version = PACKAGE_STRING;
const char *argp_program_bug_address = PACKAGE_BUGREPORT;
static const char usage_doc[] = "[CMD [ARG..]]";
static const char doc[] = "Tool using Linux namespaces to provide root like functionality for unprivileged users.";
struct opts {
char **child_argv;
size_t child_argc;
bool binfmt;
};
enum option_key {
OPT_BINFMT = 260,
};
static struct argp_option options[] = {
{"debug", 'd', NULL, 0, "Report uroot operations.", 0},
{"binfmt", OPT_BINFMT, NULL, 0, "Preserve registered misc binary format handlers.", 0},
{NULL}
};
static error_t parse_opt(int key, char *arg, struct argp_state *state) {
struct opts *opts = state->input;
switch (key) {
case 'd':
// TODO logging
break;
case OPT_BINFMT:
opts->binfmt = true;
break;
case ARGP_KEY_ARGS:
opts->child_argc = state->argc - state->next;
opts->child_argv = malloc((opts->child_argc + 1) * sizeof *opts->child_argv);
memcpy(opts->child_argv, state->argv + state->next, opts->child_argc *
sizeof *opts->child_argv);
opts->child_argv[opts->child_argc] = NULL;
break;
case ARGP_KEY_INIT:
opts->child_argv = NULL;
opts->child_argc = 0;
opts->binfmt = false;
break;
default:
return ARGP_ERR_UNKNOWN;
};
return 0;
}
static const struct argp argp_parser = {
.options = options,
.parser = parse_opt,
.args_doc = usage_doc,
.doc = doc,
};
int main(int argc, char **argv) {
struct opts opts;
argp_parse(&argp_parser, argc, argv, ARGP_IN_ORDER, 0, &opts);
struct child_args chargs = (struct child_args) {
.ppid = getpid(),
.argc = opts.child_argc,
.argv = opts.child_argv,
.sigpipe = sigpipe_new(),
.binfmt = opts.binfmt,
};
uint8_t stack[STACK_SIZE];
pid_t chpid = clone(child_main, stack + STACK_SIZE,
SIGCHLD | CLONE_NEWNS | CLONE_NEWUSER | CLONE_NEWPID,
&chargs);
#define FAIL(MSG) do { fputs(MSG, stderr); kill(chpid, SIGKILL); return 1; } while (false);
if (new_map_id(MAP_ID_USER, chpid, getuid()))
FAIL("Mapping of uid failed!\n");
if (new_map_id(MAP_ID_GROUP, chpid, getgid()))
FAIL("Mapping of gid failed!\n");
sigpipe_signal(chargs.sigpipe);
int stat;
waitpid(chpid, &stat, 0);
if (WIFEXITED(stat))
return WEXITSTATUS(stat);
else
return WIFSIGNALED(stat) || WCOREDUMP(stat);
}
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