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|
/*
* Copyright (C) 2014-2016 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/wait.h>
#include <sys/stat.h>
#include <sys/prctl.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/types.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <sched.h>
#ifndef CLONE_NEWUSER
#define CLONE_NEWUSER 0x10000000
#endif
#include <sys/prctl.h>
#ifndef PR_SET_NO_NEW_PRIVS
# define PR_SET_NO_NEW_PRIVS 38
#endif
#ifdef HAVE_APPARMOR
#include <sys/apparmor.h>
#endif
static int monitored_pid = 0;
static void sandbox_handler(int sig){
if (!arg_quiet) {
printf("\nChild received signal %d, shutting down the sandbox...\n", sig);
fflush(0);
}
// broadcast sigterm to all processes in the group
kill(-1, SIGTERM);
sleep(1);
if (monitored_pid) {
int monsec = 9;
char *monfile;
if (asprintf(&monfile, "/proc/%d/cmdline", monitored_pid) == -1)
errExit("asprintf");
while (monsec) {
FILE *fp = fopen(monfile, "r");
if (!fp)
break;
char c;
size_t count = fread(&c, 1, 1, fp);
fclose(fp);
if (count == 0)
break;
if (arg_debug)
printf("Waiting on PID %d to finish\n", monitored_pid);
sleep(1);
monsec--;
}
free(monfile);
}
// broadcast a SIGKILL
kill(-1, SIGKILL);
flush_stdin();
exit(sig);
}
static void set_caps(void) {
if (arg_caps_drop_all)
caps_drop_all();
else if (arg_caps_drop)
caps_drop_list(arg_caps_list);
else if (arg_caps_keep)
caps_keep_list(arg_caps_list);
else if (arg_caps_default_filter)
caps_default_filter();
}
void save_nogroups(void) {
if (arg_nogroups == 0)
return;
FILE *fp = fopen(RUN_GROUPS_CFG, "w");
if (fp) {
fprintf(fp, "\n");
SET_PERMS_STREAM(fp, 0, 0, 0644); // assume mode 0644
fclose(fp);
}
else {
fprintf(stderr, "Error: cannot save nogroups state\n");
exit(1);
}
}
static void sandbox_if_up(Bridge *br) {
assert(br);
if (!br->configured)
return;
char *dev = br->devsandbox;
net_if_up(dev);
if (br->arg_ip_none == 1); // do nothing
else if (br->arg_ip_none == 0 && br->macvlan == 0) {
if (br->ipsandbox == br->ip) {
fprintf(stderr, "Error: %d.%d.%d.%d is interface %s address.\n", PRINT_IP(br->ipsandbox), br->dev);
exit(1);
}
// just assign the address
assert(br->ipsandbox);
if (arg_debug)
printf("Configuring %d.%d.%d.%d address on interface %s\n", PRINT_IP(br->ipsandbox), dev);
net_config_interface(dev, br->ipsandbox, br->mask, br->mtu);
}
else if (br->arg_ip_none == 0 && br->macvlan == 1) {
// reassign the macvlan address
if (br->ipsandbox == 0)
// ip address assigned by arp-scan for a macvlan device
br->ipsandbox = arp_assign(dev, br); //br->ip, br->mask);
else {
if (br->ipsandbox == br->ip) {
fprintf(stderr, "Error: %d.%d.%d.%d is interface %s address.\n", PRINT_IP(br->ipsandbox), br->dev);
exit(1);
}
uint32_t rv = arp_check(dev, br->ipsandbox, br->ip);
if (rv) {
fprintf(stderr, "Error: the address %d.%d.%d.%d is already in use.\n", PRINT_IP(br->ipsandbox));
exit(1);
}
}
if (arg_debug)
printf("Configuring %d.%d.%d.%d address on interface %s\n", PRINT_IP(br->ipsandbox), dev);
net_config_interface(dev, br->ipsandbox, br->mask, br->mtu);
}
if (br->ip6sandbox)
net_if_ip6(dev, br->ip6sandbox);
}
static void chk_chroot(void) {
// if we are starting firejail inside some other container technology, we don't care about this
char *mycont = getenv("container");
if (mycont)
return;
// check if this is a regular chroot
struct stat s;
if (stat("/", &s) == 0) {
if (s.st_ino != 2)
return;
}
fprintf(stderr, "Error: cannot mount filesystem as slave\n");
exit(1);
}
static int monitor_application(pid_t app_pid) {
monitored_pid = app_pid;
signal (SIGTERM, sandbox_handler);
EUID_USER();
int status = 0;
while (monitored_pid) {
usleep(20000);
char *msg;
if (asprintf(&msg, "monitoring pid %d\n", monitored_pid) == -1)
errExit("asprintf");
logmsg(msg);
if (arg_debug)
printf("%s\n", msg);
free(msg);
pid_t rv;
do {
rv = waitpid(-1, &status, 0);
if (rv == -1)
break;
}
while(rv != monitored_pid);
if (arg_debug)
printf("Sandbox monitor: waitpid %u retval %d status %d\n", monitored_pid, rv, status);
// if /proc is not remounted, we cannot check /proc directory,
// for now we just get out of here
// todo: find another way of checking child processes!
if (!checkcfg(CFG_REMOUNT_PROC_SYS))
break;
DIR *dir;
if (!(dir = opendir("/proc"))) {
// sleep 2 seconds and try again
sleep(2);
if (!(dir = opendir("/proc"))) {
fprintf(stderr, "Error: cannot open /proc directory\n");
exit(1);
}
}
struct dirent *entry;
monitored_pid = 0;
while ((entry = readdir(dir)) != NULL) {
unsigned pid;
if (sscanf(entry->d_name, "%u", &pid) != 1)
continue;
if (pid == 1)
continue;
// todo: make this generic
// Dillo browser leaves a dpid process running, we need to shut it down
int found = 0;
if (strcmp(cfg.command_name, "dillo") == 0) {
char *pidname = pid_proc_comm(pid);
if (pidname && strcmp(pidname, "dpid") == 0)
found = 1;
free(pidname);
}
if (found)
break;
monitored_pid = pid;
break;
}
closedir(dir);
if (monitored_pid != 0 && arg_debug)
printf("Sandbox monitor: monitoring %u\n", monitored_pid);
}
// return the latest exit status.
return status;
}
void start_audit(void) {
char *audit_prog;
if (asprintf(&audit_prog, "%s/firejail/faudit", LIBDIR) == -1)
errExit("asprintf");
assert(getenv("LD_PRELOAD") == NULL);
execl(audit_prog, audit_prog, NULL);
perror("execl");
exit(1);
}
void start_application(void) {
//if (setsid() == -1)
//errExit("setsid");
// set environment
env_defaults();
env_apply();
if (arg_debug) {
printf("starting application\n");
printf("LD_PRELOAD=%s\n", getenv("LD_PRELOAD"));
}
//****************************************
// audit
//****************************************
if (arg_audit) {
assert(arg_audit_prog);
#ifdef HAVE_GCOV
__gcov_dump();
#endif
execl(arg_audit_prog, arg_audit_prog, NULL);
}
//****************************************
// start the program without using a shell
//****************************************
else if (arg_shell_none) {
if (arg_debug) {
int i;
for (i = cfg.original_program_index; i < cfg.original_argc; i++) {
if (cfg.original_argv[i] == NULL)
break;
printf("execvp argument %d: %s\n", i - cfg.original_program_index, cfg.original_argv[i]);
}
}
if (cfg.original_program_index == 0) {
fprintf(stderr, "Error: --shell=none configured, but no program specified\n");
exit(1);
}
if (!arg_command && !arg_quiet)
printf("Child process initialized\n");
#ifdef HAVE_GCOV
__gcov_dump();
#endif
execvp(cfg.original_argv[cfg.original_program_index], &cfg.original_argv[cfg.original_program_index]);
exit(1);
}
//****************************************
// start the program using a shell
//****************************************
else {
assert(cfg.shell);
assert(cfg.command_line);
char *arg[5];
int index = 0;
arg[index++] = cfg.shell;
if (login_shell) {
arg[index++] = "-l";
if (arg_debug)
printf("Starting %s login shell\n", cfg.shell);
} else {
arg[index++] = "-c";
if (arg_debug)
printf("Running %s command through %s\n", cfg.command_line, cfg.shell);
if (arg_doubledash)
arg[index++] = "--";
arg[index++] = cfg.command_line;
}
arg[index] = NULL;
assert(index < 5);
if (arg_debug) {
char *msg;
if (asprintf(&msg, "sandbox %d, execvp into %s", sandbox_pid, cfg.command_line) == -1)
errExit("asprintf");
logmsg(msg);
free(msg);
}
if (arg_debug) {
int i;
for (i = 0; i < 5; i++) {
if (arg[i] == NULL)
break;
printf("execvp argument %d: %s\n", i, arg[i]);
}
}
if (!arg_command && !arg_quiet)
printf("Child process initialized\n");
#ifdef HAVE_GCOV
__gcov_dump();
#endif
execvp(arg[0], arg);
}
perror("execvp");
exit(1); // it should never get here!!!
}
static void enforce_filters(void) {
// force default seccomp inside the chroot, no keep or drop list
// the list build on top of the default drop list is kept intact
arg_seccomp = 1;
if (cfg.seccomp_list_drop) {
free(cfg.seccomp_list_drop);
cfg.seccomp_list_drop = NULL;
}
if (cfg.seccomp_list_keep) {
free(cfg.seccomp_list_keep);
cfg.seccomp_list_keep = NULL;
}
// disable all capabilities
if (arg_caps_default_filter || arg_caps_list && !arg_quiet)
fprintf(stderr, "Warning: all capabilities disabled for a regular user in chroot\n");
arg_caps_drop_all = 1;
// drop all supplementary groups; /etc/group file inside chroot
// is controlled by a regular usr
arg_nogroups = 1;
if (!arg_quiet)
printf("Dropping all Linux capabilities and enforcing default seccomp filter\n");
}
int sandbox(void* sandbox_arg) {
// Get rid of unused parameter warning
(void)sandbox_arg;
pid_t child_pid = getpid();
if (arg_debug)
printf("Initializing child process\n");
// close each end of the unused pipes
close(parent_to_child_fds[1]);
close(child_to_parent_fds[0]);
// wait for parent to do base setup
wait_for_other(parent_to_child_fds[0]);
if (arg_debug && child_pid == 1)
printf("PID namespace installed\n");
//****************************
// set hostname
//****************************
if (cfg.hostname) {
if (sethostname(cfg.hostname, strlen(cfg.hostname)) < 0)
errExit("sethostname");
}
//****************************
// mount namespace
//****************************
// mount events are not forwarded between the host the sandbox
if (mount(NULL, "/", NULL, MS_SLAVE | MS_REC, NULL) < 0) {
chk_chroot();
}
// ... and mount a tmpfs on top of /run/firejail/mnt directory
preproc_mount_mnt_dir();
//****************************
// log sandbox data
//****************************
if (cfg.name)
fs_logger2("sandbox name:", cfg.name);
fs_logger2int("sandbox pid:", (int) sandbox_pid);
if (cfg.chrootdir)
fs_logger("sandbox filesystem: chroot");
else if (arg_overlay)
fs_logger("sandbox filesystem: overlay");
else
fs_logger("sandbox filesystem: local");
fs_logger("install mount namespace");
//****************************
// netfilter
//****************************
if (arg_netfilter && any_bridge_configured()) { // assuming by default the client filter
netfilter(arg_netfilter_file);
}
if (arg_netfilter6 && any_bridge_configured()) { // assuming by default the client filter
netfilter6(arg_netfilter6_file);
}
//****************************
// networking
//****************************
int gw_cfg_failed = 0; // default gw configuration flag
if (arg_nonetwork) {
net_if_up("lo");
if (arg_debug)
printf("Network namespace enabled, only loopback interface available\n");
}
else if (arg_netns) {
netns(arg_netns);
if (arg_debug)
printf("Network namespace '%s' activated\n", arg_netns);
}
else if (any_bridge_configured() || any_interface_configured()) {
// configure lo and eth0...eth3
net_if_up("lo");
if (mac_not_zero(cfg.bridge0.macsandbox))
net_config_mac(cfg.bridge0.devsandbox, cfg.bridge0.macsandbox);
sandbox_if_up(&cfg.bridge0);
if (mac_not_zero(cfg.bridge1.macsandbox))
net_config_mac(cfg.bridge1.devsandbox, cfg.bridge1.macsandbox);
sandbox_if_up(&cfg.bridge1);
if (mac_not_zero(cfg.bridge2.macsandbox))
net_config_mac(cfg.bridge2.devsandbox, cfg.bridge2.macsandbox);
sandbox_if_up(&cfg.bridge2);
if (mac_not_zero(cfg.bridge3.macsandbox))
net_config_mac(cfg.bridge3.devsandbox, cfg.bridge3.macsandbox);
sandbox_if_up(&cfg.bridge3);
// moving an interface in a namespace using --interface will reset the interface configuration;
// we need to put the configuration back
if (cfg.interface0.configured && cfg.interface0.ip) {
if (arg_debug)
printf("Configuring %d.%d.%d.%d address on interface %s\n", PRINT_IP(cfg.interface0.ip), cfg.interface0.dev);
net_config_interface(cfg.interface0.dev, cfg.interface0.ip, cfg.interface0.mask, cfg.interface0.mtu);
}
if (cfg.interface1.configured && cfg.interface1.ip) {
if (arg_debug)
printf("Configuring %d.%d.%d.%d address on interface %s\n", PRINT_IP(cfg.interface1.ip), cfg.interface1.dev);
net_config_interface(cfg.interface1.dev, cfg.interface1.ip, cfg.interface1.mask, cfg.interface1.mtu);
}
if (cfg.interface2.configured && cfg.interface2.ip) {
if (arg_debug)
printf("Configuring %d.%d.%d.%d address on interface %s\n", PRINT_IP(cfg.interface2.ip), cfg.interface2.dev);
net_config_interface(cfg.interface2.dev, cfg.interface2.ip, cfg.interface2.mask, cfg.interface2.mtu);
}
if (cfg.interface3.configured && cfg.interface3.ip) {
if (arg_debug)
printf("Configuring %d.%d.%d.%d address on interface %s\n", PRINT_IP(cfg.interface3.ip), cfg.interface3.dev);
net_config_interface(cfg.interface3.dev, cfg.interface3.ip, cfg.interface3.mask, cfg.interface3.mtu);
}
// add a default route
if (cfg.defaultgw) {
// set the default route
if (net_add_route(0, 0, cfg.defaultgw)) {
if (!arg_quiet)
fprintf(stderr, "Warning: cannot configure default route\n");
gw_cfg_failed = 1;
}
}
if (arg_debug)
printf("Network namespace enabled\n");
}
// print network configuration
if (!arg_quiet) {
if (any_bridge_configured() || any_interface_configured() || cfg.defaultgw || cfg.dns1) {
printf("\n");
if (any_bridge_configured() || any_interface_configured()) {
// net_ifprint();
if (arg_scan)
sbox_run(SBOX_ROOT | SBOX_CAPS_NETWORK | SBOX_SECCOMP, 3, PATH_FNET, "printif", "scan");
else
sbox_run(SBOX_ROOT | SBOX_CAPS_NETWORK | SBOX_SECCOMP, 2, PATH_FNET, "printif", "scan");
}
if (cfg.defaultgw != 0) {
if (gw_cfg_failed)
printf("Default gateway configuration failed\n");
else
printf("Default gateway %d.%d.%d.%d\n", PRINT_IP(cfg.defaultgw));
}
if (cfg.dns1 != 0)
printf("DNS server %d.%d.%d.%d\n", PRINT_IP(cfg.dns1));
if (cfg.dns2 != 0)
printf("DNS server %d.%d.%d.%d\n", PRINT_IP(cfg.dns2));
if (cfg.dns3 != 0)
printf("DNS server %d.%d.%d.%d\n", PRINT_IP(cfg.dns3));
printf("\n");
}
}
// load IBUS env variables
if (arg_nonetwork || any_bridge_configured() || any_interface_configured()) {
// do nothing - there are problems with ibus version 1.5.11
}
else
env_ibus_load();
//****************************
// fs pre-processing:
// - build seccomp filters
// - create an empty /etc/ld.so.preload
//****************************
#ifdef HAVE_SECCOMP
if (cfg.protocol) {
if (arg_debug)
printf("Build protocol filter: %s\n", cfg.protocol);
// build the seccomp filter as a regular user
int rv = sbox_run(SBOX_USER | SBOX_CAPS_NONE | SBOX_SECCOMP, 5,
PATH_FSECCOMP, "protocol", "build", cfg.protocol, RUN_SECCOMP_PROTOCOL);
if (rv)
exit(rv);
}
#endif
// trace pre-install
if (arg_trace || arg_tracelog || mask_x11_abstract_socket)
fs_trace_preload();
// store hosts file
if (cfg.hosts_file)
fs_store_hosts_file();
//****************************
// configure filesystem
//****************************
#ifdef HAVE_SECCOMP
int enforce_seccomp = 0;
#endif
if (arg_appimage) {
enforce_filters();
#ifdef HAVE_SECCOMP
enforce_seccomp = 1;
#endif
}
#ifdef HAVE_CHROOT
if (cfg.chrootdir) {
fs_chroot(cfg.chrootdir);
// force caps and seccomp if not started as root
if (getuid() != 0) {
enforce_filters();
#ifdef HAVE_SECCOMP
enforce_seccomp = 1;
#endif
}
else
arg_seccomp = 1;
//****************************
// trace pre-install, this time inside chroot
//****************************
if (arg_trace || arg_tracelog || mask_x11_abstract_socket)
fs_trace_preload();
}
else
#endif
#ifdef HAVE_OVERLAYFS
if (arg_overlay) {
fs_overlayfs();
//todo - bring it back for overlay-named
#if 0
fs_overlayfs();
// force caps and seccomp if not started as root
if (getuid() != 0) {
enforce_filters();
#ifdef HAVE_SECCOMP
enforce_seccomp = 1;
#endif
}
else
arg_seccomp = 1;
#endif
}
else
#endif
fs_basic_fs();
//****************************
// private mode
//****************************
if (arg_private) {
if (cfg.home_private) { // --private=
if (cfg.chrootdir)
fprintf(stderr, "Warning: private=directory feature is disabled in chroot\n");
else if (arg_overlay)
fprintf(stderr, "Warning: private=directory feature is disabled in overlay\n");
else
fs_private_homedir();
}
else if (cfg.home_private_keep) { // --private-home=
if (cfg.chrootdir)
fprintf(stderr, "Warning: private-home= feature is disabled in chroot\n");
else if (arg_overlay)
fprintf(stderr, "Warning: private-home= feature is disabled in overlay\n");
else
fs_private_home_list();
}
else // --private
fs_private();
}
if (arg_private_dev) {
if (cfg.chrootdir)
fprintf(stderr, "Warning: private-dev feature is disabled in chroot\n");
else if (arg_overlay)
fprintf(stderr, "Warning: private-dev feature is disabled in overlay\n");
else
fs_private_dev();
}
if (arg_private_etc) {
if (cfg.chrootdir)
fprintf(stderr, "Warning: private-etc feature is disabled in chroot\n");
else if (arg_overlay)
fprintf(stderr, "Warning: private-etc feature is disabled in overlay\n");
else {
fs_private_dir_list("/etc", RUN_ETC_DIR, cfg.etc_private_keep);
// create /etc/ld.so.preload file again
if (arg_trace || arg_tracelog || mask_x11_abstract_socket)
fs_trace_preload();
}
}
if (arg_private_opt) {
if (cfg.chrootdir)
fprintf(stderr, "Warning: private-opt feature is disabled in chroot\n");
else if (arg_overlay)
fprintf(stderr, "Warning: private-opt feature is disabled in overlay\n");
else {
fs_private_dir_list("/opt", RUN_OPT_DIR, cfg.opt_private_keep);
}
}
if (arg_private_srv) {
if (cfg.chrootdir)
fprintf(stderr, "Warning: private-srv feature is disabled in chroot\n");
else if (arg_overlay)
fprintf(stderr, "Warning: private-srv feature is disabled in overlay\n");
else {
fs_private_dir_list("/srv", RUN_SRV_DIR, cfg.srv_private_keep);
}
}
if (arg_private_bin) {
if (cfg.chrootdir)
fprintf(stderr, "Warning: private-bin feature is disabled in chroot\n");
else if (arg_overlay)
fprintf(stderr, "Warning: private-bin feature is disabled in overlay\n");
else {
// for --x11=xorg we need to add xauth command
if (arg_x11_xorg) {
EUID_USER();
char *tmp;
if (asprintf(&tmp, "%s,xauth", cfg.bin_private_keep) == -1)
errExit("asprintf");
cfg.bin_private_keep = tmp;
EUID_ROOT();
}
fs_private_bin_list();
}
}
if (arg_private_tmp) {
if (cfg.chrootdir)
fprintf(stderr, "Warning: private-tmp feature is disabled in chroot\n");
else if (arg_overlay)
fprintf(stderr, "Warning: private-tmp feature is disabled in overlay\n");
else {
// private-tmp is implemented as a whitelist
EUID_USER();
profile_add("whitelist /tmp/.X11-unix");
EUID_ROOT();
}
}
//****************************
// hosts and hostname
//****************************
if (cfg.hostname)
fs_hostname(cfg.hostname);
if (cfg.hosts_file)
fs_mount_hosts_file();
//****************************
// /etc overrides from the network namespace
//****************************
if (arg_netns)
netns_mounts(arg_netns);
//****************************
// update /proc, /sys, /dev, /boot directorymy
//****************************
if (checkcfg(CFG_REMOUNT_PROC_SYS))
fs_proc_sys_dev_boot();
//****************************
// apply the profile file
//****************************
// apply all whitelist commands ...
if (cfg.chrootdir)
fprintf(stderr, "Warning: whitelist feature is disabled in chroot\n");
else if (arg_overlay)
fprintf(stderr, "Warning: whitelist feature is disabled in overlay\n");
else
fs_whitelist();
// ... followed by blacklist commands
fs_blacklist(); // mkdir and mkfile are processed all over again
//****************************
// install trace
//****************************
if (arg_trace || arg_tracelog || mask_x11_abstract_socket)
fs_trace();
//****************************
// nosound/no3d and fix for pulseaudio 7.0
//****************************
if (arg_nosound) {
// disable pulseaudio
pulseaudio_disable();
// disable /dev/snd
fs_dev_disable_sound();
}
else
pulseaudio_init();
if (arg_no3d)
fs_dev_disable_3d();
//****************************
// set dns
//****************************
fs_resolvconf();
//****************************
// fs post-processing
//****************************
fs_logger_print();
fs_logger_change_owner();
//****************************
// set application environment
//****************************
prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); // kill the child in case the parent died
int cwd = 0;
if (cfg.cwd) {
if (chdir(cfg.cwd) == 0)
cwd = 1;
}
if (!cwd) {
if (chdir("/") < 0)
errExit("chdir");
if (cfg.homedir) {
struct stat s;
if (stat(cfg.homedir, &s) == 0) {
/* coverity[toctou] */
if (chdir(cfg.homedir) < 0)
errExit("chdir");
}
}
}
// set nice
if (arg_nice) {
errno = 0;
int rv = nice(cfg.nice);
(void) rv;
if (errno) {
if (!arg_quiet)
fprintf(stderr, "Warning: cannot set nice value\n");
errno = 0;
}
}
// clean /tmp/.X11-unix sockets
fs_x11();
if (arg_x11_xorg)
x11_xorg();
//****************************
// set security filters
//****************************
// set capabilities
// if (!arg_noroot)
set_caps();
// set rlimits
set_rlimits();
// set cpu affinity
if (cfg.cpus) {
save_cpu(); // save cpu affinity mask to CPU_CFG file
set_cpu_affinity();
}
// save cgroup in CGROUP_CFG file
if (cfg.cgroup)
save_cgroup();
// set seccomp //todo: push it down after drop_privs and/or configuring noroot
#ifdef HAVE_SECCOMP
// install protocol filter
if (cfg.protocol) {
if (arg_debug)
printf("Install protocol filter: %s\n", cfg.protocol);
seccomp_load(RUN_SECCOMP_PROTOCOL); // install filter
protocol_filter_save(); // save filter in RUN_PROTOCOL_CFG
}
// if a keep list is available, disregard the drop list
if (arg_seccomp == 1) {
if (cfg.seccomp_list_keep)
seccomp_filter_keep();
else
seccomp_filter_drop(enforce_seccomp);
}
#endif
//****************************************
// drop privileges or create a new user namespace
//****************************************
save_nogroups();
if (arg_noroot) {
int rv = unshare(CLONE_NEWUSER);
if (rv == -1) {
if (!arg_quiet)
fprintf(stderr, "Warning: cannot create a new user namespace, going forward without it...\n");
drop_privs(arg_nogroups);
arg_noroot = 0;
}
}
else
drop_privs(arg_nogroups);
// notify parent that new user namespace has been created so a proper
// UID/GID map can be setup
notify_other(child_to_parent_fds[1]);
close(child_to_parent_fds[1]);
// wait for parent to finish setting up a proper UID/GID map
wait_for_other(parent_to_child_fds[0]);
close(parent_to_child_fds[0]);
// somehow, the new user namespace resets capabilities;
// we need to do them again
if (arg_noroot) {
if (arg_debug)
printf("noroot user namespace installed\n");
set_caps();
}
//****************************************
// Set NO_NEW_PRIVS if desired
//****************************************
if (arg_nonewprivs) {
int no_new_privs = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
if(no_new_privs != 0 && !arg_quiet)
fprintf(stderr, "Warning: NO_NEW_PRIVS disabled, it requires a Linux kernel version 3.5 or newer.\n");
else if (arg_debug)
printf("NO_NEW_PRIVS set\n");
}
//****************************************
// fork the application and monitor it
//****************************************
pid_t app_pid = fork();
if (app_pid == -1)
errExit("fork");
if (app_pid == 0) {
#ifdef HAVE_APPARMOR
if (arg_apparmor) {
errno = 0;
if (aa_change_onexec("firejail-default")) {
fprintf(stderr, "Error: cannot confine the application using AppArmor.\n");
fprintf(stderr, "Maybe firejail-default AppArmor profile is not loaded into the kernel.\n");
fprintf(stderr, "As root, run \"aa-enforce firejail-default\" to load it.\n");
exit(1);
}
else if (arg_debug)
printf("AppArmor enabled\n");
}
#endif
prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); // kill the child in case the parent died
start_application(); // start app
}
int status = monitor_application(app_pid); // monitor application
flush_stdin();
if (WIFEXITED(status)) {
// if we had a proper exit, return that exit status
return WEXITSTATUS(status);
} else {
// something else went wrong!
return -1;
}
}
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