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/*
* Copyright (C) 2014-2022 Firejail Authors
*
* This file is part of firejail project
*
* 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.
*/
#include "firejail.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
void run_symlink(int argc, char **argv, int run_as_is) {
EUID_ASSERT();
char *program = strrchr(argv[0], '/');
if (program)
program += 1;
else
program = argv[0];
if (strcmp(program, "firejail") == 0) // this is a regular "firejail program" sandbox starting
return;
// drop privileges
if (setresgid(-1, getgid(), getgid()) != 0)
errExit("setresgid");
if (setresuid(-1, getuid(), getuid()) != 0)
errExit("setresuid");
// find the real program by looking in PATH
const char *path = env_get("PATH");
if (!path) {
fprintf(stderr, "Error: PATH environment variable not set\n");
exit(1);
}
char *p = find_in_path(program);
if (!p) {
fprintf(stderr, "Error: cannot find the program in the path\n");
exit(1);
}
program = p;
// restore original umask
umask(orig_umask);
// restore original environment variables
env_apply_all();
// desktop integration is not supported for root user; instead, the original program is started
if (getuid() == 0 || run_as_is) {
argv[0] = program;
execv(program, argv);
exit(1);
}
// start the argv[0] program in a new sandbox
char *a[3 + argc];
a[0] =PATH_FIREJAIL;
a[1] = program;
int i;
for (i = 0; i < (argc - 1); i++) {
a[i + 2] = argv[i + 1];
}
a[i + 2] = NULL;
if (env_get("LD_PRELOAD") != NULL)
fprintf(stderr, "run_symlink: LD_PRELOAD is: '%s'\n", env_get("LD_PRELOAD"));
assert(env_get("LD_PRELOAD") == NULL);
assert(getenv("LD_PRELOAD") == NULL);
execvp(a[0], a);
perror("execvp");
exit(1);
}
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