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/*
* Copyright (C) 2014-2018 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/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <fcntl.h>
void check_netfilter_file(const char *fname) {
EUID_ASSERT();
char *tmp = strdup(fname);
if (!tmp)
errExit("strdup");
char *ptr = strchr(tmp, ',');
if (ptr)
*ptr = '\0';
invalid_filename(tmp, 0); // no globbing
if (is_dir(tmp) || is_link(tmp) || strstr(tmp, "..") || access(tmp, R_OK )) {
fprintf(stderr, "Error: invalid network filter file %s\n", tmp);
exit(1);
}
free(tmp);
}
void netfilter(const char *fname) {
// find iptables command
struct stat s;
char *iptables = NULL;
char *iptables_restore = NULL;
if (stat("/sbin/iptables", &s) == 0) {
iptables = "/sbin/iptables";
iptables_restore = "/sbin/iptables-restore";
}
else if (stat("/usr/sbin/iptables", &s) == 0) {
iptables = "/usr/sbin/iptables";
iptables_restore = "/usr/sbin/iptables-restore";
}
if (iptables == NULL || iptables_restore == NULL) {
fprintf(stderr, "Error: iptables command not found, netfilter not configured\n");
return;
}
if (arg_debug)
printf("Installing firewall\n");
// create an empty user-owned SBOX_STDIN_FILE
create_empty_file_as_root(SBOX_STDIN_FILE, 0644);
if (set_perms(SBOX_STDIN_FILE, getuid(), getgid(), 0644))
errExit("set_perms");
if (fname == NULL) {
if (netfilter_default)
sbox_run(SBOX_USER| SBOX_CAPS_NONE | SBOX_SECCOMP, 3, PATH_FNETFILTER, netfilter_default, SBOX_STDIN_FILE);
else
sbox_run(SBOX_USER| SBOX_CAPS_NONE | SBOX_SECCOMP, 2, PATH_FNETFILTER, SBOX_STDIN_FILE);
}
else
sbox_run(SBOX_USER| SBOX_CAPS_NONE | SBOX_SECCOMP, 3, PATH_FNETFILTER, fname, SBOX_STDIN_FILE);
// first run of iptables on this platform installs a number of kernel modules such as ip_tables, x_tables, iptable_filter
// we run this command with caps and seccomp disabled in order to allow the loading of these modules
sbox_run(SBOX_ROOT | SBOX_STDIN_FROM_FILE, 1, iptables_restore);
unlink(SBOX_STDIN_FILE);
// debug
if (arg_debug)
sbox_run(SBOX_ROOT | SBOX_CAPS_NETWORK | SBOX_SECCOMP, 2, iptables, "-vL");
return;
}
void netfilter6(const char *fname) {
if (fname == NULL)
return;
// find iptables command
char *ip6tables = NULL;
char *ip6tables_restore = NULL;
struct stat s;
if (stat("/sbin/ip6tables", &s) == 0) {
ip6tables = "/sbin/ip6tables";
ip6tables_restore = "/sbin/ip6tables-restore";
}
else if (stat("/usr/sbin/ip6tables", &s) == 0) {
ip6tables = "/usr/sbin/ip6tables";
ip6tables_restore = "/usr/sbin/ip6tables-restore";
}
if (ip6tables == NULL || ip6tables_restore == NULL) {
fprintf(stderr, "Error: ip6tables command not found, netfilter6 not configured\n");
return;
}
if (arg_debug)
printf("Installing IPv6 firewall\n");
// create an empty user-owned SBOX_STDIN_FILE
create_empty_file_as_root(SBOX_STDIN_FILE, 0644);
if (set_perms(SBOX_STDIN_FILE, getuid(), getgid(), 0644))
errExit("set_perms");
sbox_run(SBOX_USER| SBOX_CAPS_NONE | SBOX_SECCOMP, 3, PATH_FNETFILTER, fname, SBOX_STDIN_FILE);
// first run of iptables on this platform installs a number of kernel modules such as ip_tables, x_tables, iptable_filter
// we run this command with caps and seccomp disabled in order to allow the loading of these modules
sbox_run(SBOX_ROOT | SBOX_STDIN_FROM_FILE, 1, ip6tables_restore);
unlink(SBOX_STDIN_FILE);
// debug
if (arg_debug)
sbox_run(SBOX_ROOT | SBOX_CAPS_NETWORK | SBOX_SECCOMP, 2, ip6tables, "-vL");
return;
}
void netfilter_print(pid_t pid, int ipv6) {
EUID_ASSERT();
enter_network_namespace(pid);
// find iptables executable
char *iptables = NULL;
// char *iptables_restore = NULL;
struct stat s;
if (ipv6) {
if (stat("/sbin/ip6tables", &s) == 0)
iptables = "/sbin/ip6tables";
else if (stat("/usr/sbin/ip6tables", &s) == 0)
iptables = "/usr/sbin/ip6tables";
}
else {
if (stat("/sbin/iptables", &s) == 0)
iptables = "/sbin/iptables";
else if (stat("/usr/sbin/iptables", &s) == 0)
iptables = "/usr/sbin/iptables";
}
if (iptables == NULL) {
fprintf(stderr, "Error: iptables command not found\n");
exit(1);
}
sbox_run(SBOX_ROOT | SBOX_CAPS_NETWORK | SBOX_SECCOMP, 2, iptables, "-vL");
}
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