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/*
* Copyright (C) 2014-2019 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 <linux/limits.h>
#include <glob.h>
#include <dirent.h>
#include <fcntl.h>
#include <pwd.h>
#ifndef _BSD_SOURCE
#define _BSD_SOURCE
#endif
#include <sys/sysmacros.h>
#include <sys/types.h>
// device type
typedef enum {
DEV_NONE = 0,
DEV_SOUND,
DEV_3D,
DEV_VIDEO,
DEV_TV,
DEV_DVD,
DEV_U2F,
} DEV_TYPE;
typedef struct {
const char *dev_fname;
const char *run_fname;
DEV_TYPE type;
} DevEntry;
static DevEntry dev[] = {
{"/dev/snd", RUN_DEV_DIR "/snd", DEV_SOUND}, // sound device
{"/dev/dri", RUN_DEV_DIR "/dri", DEV_3D}, // 3d device
{"/dev/nvidia0", RUN_DEV_DIR "/nvidia0", DEV_3D},
{"/dev/nvidia1", RUN_DEV_DIR "/nvidia1", DEV_3D},
{"/dev/nvidia2", RUN_DEV_DIR "/nvidia2", DEV_3D},
{"/dev/nvidia3", RUN_DEV_DIR "/nvidia3", DEV_3D},
{"/dev/nvidia4", RUN_DEV_DIR "/nvidia4", DEV_3D},
{"/dev/nvidia5", RUN_DEV_DIR "/nvidia5", DEV_3D},
{"/dev/nvidia6", RUN_DEV_DIR "/nvidia6", DEV_3D},
{"/dev/nvidia7", RUN_DEV_DIR "/nvidia7", DEV_3D},
{"/dev/nvidia8", RUN_DEV_DIR "/nvidia8", DEV_3D},
{"/dev/nvidia9", RUN_DEV_DIR "/nvidia9", DEV_3D},
{"/dev/nvidiactl", RUN_DEV_DIR "/nvidiactl", DEV_3D},
{"/dev/nvidia-modeset", RUN_DEV_DIR "/nvidia-modeset", DEV_3D},
{"/dev/nvidia-uvm", RUN_DEV_DIR "/nvidia-uvm", DEV_3D},
{"/dev/video0", RUN_DEV_DIR "/video0", DEV_VIDEO}, // video camera devices
{"/dev/video1", RUN_DEV_DIR "/video1", DEV_VIDEO},
{"/dev/video2", RUN_DEV_DIR "/video2", DEV_VIDEO},
{"/dev/video3", RUN_DEV_DIR "/video3", DEV_VIDEO},
{"/dev/video4", RUN_DEV_DIR "/video4", DEV_VIDEO},
{"/dev/video5", RUN_DEV_DIR "/video5", DEV_VIDEO},
{"/dev/video6", RUN_DEV_DIR "/video6", DEV_VIDEO},
{"/dev/video7", RUN_DEV_DIR "/video7", DEV_VIDEO},
{"/dev/video8", RUN_DEV_DIR "/video8", DEV_VIDEO},
{"/dev/video9", RUN_DEV_DIR "/video9", DEV_VIDEO},
{"/dev/dvb", RUN_DEV_DIR "/dvb", DEV_TV}, // DVB (Digital Video Broadcasting) - TV device
{"/dev/sr0", RUN_DEV_DIR "/sr0", DEV_DVD}, // for DVD and audio CD players
{"/dev/hidraw0", RUN_DEV_DIR "/hidraw0", DEV_U2F},
{"/dev/hidraw1", RUN_DEV_DIR "/hidraw1", DEV_U2F},
{"/dev/hidraw2", RUN_DEV_DIR "/hidraw2", DEV_U2F},
{"/dev/hidraw3", RUN_DEV_DIR "/hidraw3", DEV_U2F},
{"/dev/hidraw4", RUN_DEV_DIR "/hidraw4", DEV_U2F},
{"/dev/hidraw5", RUN_DEV_DIR "/hidraw5", DEV_U2F},
{"/dev/hidraw6", RUN_DEV_DIR "/hidraw6", DEV_U2F},
{"/dev/hidraw7", RUN_DEV_DIR "/hidraw7", DEV_U2F},
{"/dev/hidraw8", RUN_DEV_DIR "/hidraw8", DEV_U2F},
{"/dev/hidraw9", RUN_DEV_DIR "/hidraw9", DEV_U2F},
{"/dev/usb", RUN_DEV_DIR "/usb", DEV_U2F}, // USB devices such as Yubikey, U2F
{NULL, NULL, DEV_NONE}
};
static void deventry_mount(void) {
int i = 0;
while (dev[i].dev_fname != NULL) {
struct stat s;
if (stat(dev[i].run_fname, &s) == 0) {
// check device type and subsystem configuration
if ((dev[i].type == DEV_SOUND && arg_nosound == 0) ||
(dev[i].type == DEV_3D && arg_no3d == 0) ||
(dev[i].type == DEV_VIDEO && arg_novideo == 0) ||
(dev[i].type == DEV_TV && arg_notv == 0) ||
(dev[i].type == DEV_DVD && arg_nodvd == 0) ||
(dev[i].type == DEV_U2F && arg_nou2f == 0)) {
int dir = is_dir(dev[i].run_fname);
if (arg_debug)
printf("mounting %s %s\n", dev[i].run_fname, (dir)? "directory": "file");
if (dir) {
mkdir_attr(dev[i].dev_fname, 0755, 0, 0);
}
else {
struct stat s;
if (stat(dev[i].run_fname, &s) == -1) {
if (arg_debug)
fwarning("cannot stat %s file\n", dev[i].run_fname);
i++;
continue;
}
FILE *fp = fopen(dev[i].dev_fname, "w");
if (fp) {
fprintf(fp, "\n");
SET_PERMS_STREAM(fp, s.st_uid, s.st_gid, s.st_mode);
fclose(fp);
}
}
if (mount(dev[i].run_fname, dev[i].dev_fname, NULL, MS_BIND|MS_REC, NULL) < 0)
errExit("mounting dev file");
fs_logger2("whitelist", dev[i].dev_fname);
}
}
i++;
}
}
static void create_char_dev(const char *path, mode_t mode, int major, int minor) {
dev_t dev = makedev(major, minor);
if (mknod(path, S_IFCHR | mode, dev) == -1)
goto errexit;
if (chmod(path, mode) < 0)
goto errexit;
ASSERT_PERMS(path, 0, 0, mode);
fs_logger2("create", path);
return;
errexit:
fprintf(stderr, "Error: cannot create %s device\n", path);
exit(1);
}
static void create_link(const char *oldpath, const char *newpath) {
if (symlink(oldpath, newpath) == -1) {
fprintf(stderr, "Error: cannot create %s device\n", newpath);
exit(1);
}
if (chown(newpath, 0, 0) < 0) {;}
fs_logger2("create", newpath);
return;
}
static void empty_dev_shm(void) {
// create an empty /dev/shm directory
mkdir_attr("/dev/shm", 01777, 0, 0);
fs_logger("mkdir /dev/shm");
fs_logger("create /dev/shm");
}
static void mount_dev_shm(void) {
mkdir_attr("/dev/shm", 01777, 0, 0);
int rv = mount(RUN_DEV_DIR "/shm", "/dev/shm", "none", MS_BIND, "mode=01777,gid=0");
if (rv == -1) {
fwarning("cannot mount the old /dev/shm in private-dev\n");
dbg_test_dir(RUN_DEV_DIR "/shm");
empty_dev_shm();
return;
}
}
static void process_dev_shm(void) {
// Jack audio keeps an Unix socket under (/dev/shm/jack_default_1000_0 or /dev/shm/jack/...)
// looking for jack socket
glob_t globbuf;
int globerr = glob(RUN_DEV_DIR "/shm/jack*", GLOB_NOSORT, NULL, &globbuf);
if (globerr && !arg_keep_dev_shm) {
empty_dev_shm();
return;
}
globfree(&globbuf);
// if we got here, it means we have a jack server installed
// mount-bind the old /dev/shm
mount_dev_shm();
}
void fs_private_dev(void){
// install a new /dev directory
if (arg_debug)
printf("Mounting tmpfs on /dev\n");
// create DRI_DIR
// keep a copy of dev directory
mkdir_attr(RUN_DEV_DIR, 0755, 0, 0);
if (mount("/dev", RUN_DEV_DIR, NULL, MS_BIND|MS_REC, NULL) < 0)
errExit("mounting /dev");
// create DEVLOG_FILE
int have_devlog = 0;
struct stat s;
if (stat("/dev/log", &s) == 0) {
have_devlog = 1;
FILE *fp = fopen(RUN_DEVLOG_FILE, "w");
if (!fp)
have_devlog = 0;
else {
fprintf(fp, "\n");
fclose(fp);
if (mount("/dev/log", RUN_DEVLOG_FILE, NULL, MS_BIND|MS_REC, NULL) < 0)
errExit("mounting /dev/log");
}
}
// mount tmpfs on top of /dev
if (mount("tmpfs", "/dev", "tmpfs", MS_NOSUID | MS_STRICTATIME | MS_REC, "mode=755,gid=0") < 0)
errExit("mounting /dev");
fs_logger("tmpfs /dev");
// optional devices: sound, video cards etc...
deventry_mount();
// bring back /dev/log
if (have_devlog) {
FILE *fp = fopen("/dev/log", "w");
if (fp) {
fprintf(fp, "\n");
fclose(fp);
if (mount(RUN_DEVLOG_FILE, "/dev/log", NULL, MS_BIND|MS_REC, NULL) < 0)
errExit("mounting /dev/log");
fs_logger("clone /dev/log");
}
}
// bring forward the current /dev/shm directory if necessary
if (arg_debug)
printf("Process /dev/shm directory\n");
process_dev_shm();
if (mount(RUN_RO_DIR, RUN_DEV_DIR, "none", MS_BIND, "mode=400,gid=0") < 0)
errExit("disable run dev directory");
// create default devices
create_char_dev("/dev/zero", 0666, 1, 5); // mknod -m 666 /dev/zero c 1 5
fs_logger("mknod /dev/zero");
create_char_dev("/dev/null", 0666, 1, 3); // mknod -m 666 /dev/null c 1 3
fs_logger("mknod /dev/null");
create_char_dev("/dev/full", 0666, 1, 7); // mknod -m 666 /dev/full c 1 7
fs_logger("mknod /dev/full");
create_char_dev("/dev/random", 0666, 1, 8); // Mknod -m 666 /dev/random c 1 8
fs_logger("mknod /dev/random");
create_char_dev("/dev/urandom", 0666, 1, 9); // mknod -m 666 /dev/urandom c 1 9
fs_logger("mknod /dev/urandom");
create_char_dev("/dev/tty", 0666, 5, 0); // mknod -m 666 /dev/tty c 5 0
fs_logger("mknod /dev/tty");
#if 0
create_dev("/dev/tty0", "mknod -m 666 /dev/tty0 c 4 0");
create_dev("/dev/console", "mknod -m 622 /dev/console c 5 1");
#endif
// pseudo-terminal
mkdir_attr("/dev/pts", 0755, 0, 0);
fs_logger("mkdir /dev/pts");
fs_logger("create /dev/pts");
create_char_dev("/dev/pts/ptmx", 0666, 5, 2); //"mknod -m 666 /dev/pts/ptmx c 5 2");
fs_logger("mknod /dev/pts/ptmx");
create_link("/dev/pts/ptmx", "/dev/ptmx");
// code before github issue #351
// mount -vt devpts -o newinstance -o ptmxmode=0666 devpts //dev/pts
// if (mount("devpts", "/dev/pts", "devpts", MS_MGC_VAL, "newinstance,ptmxmode=0666") < 0)
// errExit("mounting /dev/pts");
// mount /dev/pts
gid_t ttygid = get_group_id("tty");
char *data;
if (asprintf(&data, "newinstance,gid=%d,mode=620,ptmxmode=0666", (int) ttygid) == -1)
errExit("asprintf");
if (mount("devpts", "/dev/pts", "devpts", MS_MGC_VAL, data) < 0)
errExit("mounting /dev/pts");
free(data);
fs_logger("clone /dev/pts");
// stdin, stdout, stderr
#if 0
create_link("/proc/self/fd", "/dev/fd");
create_link("/proc/self/fd/0", "/dev/stdin");
create_link("/proc/self/fd/1", "/dev/stdout");
create_link("/proc/self/fd/2", "/dev/stderr");
#endif
// symlinks for DVD/CD players
if (stat("/dev/sr0", &s) == 0) {
create_link("/dev/sr0", "/dev/cdrom");
create_link("/dev/sr0", "/dev/cdrw");
create_link("/dev/sr0", "/dev/dvd");
create_link("/dev/sr0", "/dev/dvdrw");
}
}
void fs_dev_disable_sound(void) {
unsigned i = 0;
while (dev[i].dev_fname != NULL) {
if (dev[i].type == DEV_SOUND)
disable_file_or_dir(dev[i].dev_fname);
i++;
}
// disable all jack sockets in /dev/shm
glob_t globbuf;
int globerr = glob("/dev/shm/jack*", GLOB_NOSORT, NULL, &globbuf);
if (globerr)
return;
for (i = 0; i < globbuf.gl_pathc; i++) {
char *path = globbuf.gl_pathv[i];
assert(path);
if (is_link(path)) {
fwarning("skipping nosound for %s because it is a symbolic link\n", path);
continue;
}
disable_file_or_dir(path);
}
globfree(&globbuf);
}
void fs_dev_disable_video(void) {
int i = 0;
while (dev[i].dev_fname != NULL) {
if (dev[i].type == DEV_VIDEO)
disable_file_or_dir(dev[i].dev_fname);
i++;
}
}
void fs_dev_disable_3d(void) {
int i = 0;
while (dev[i].dev_fname != NULL) {
if (dev[i].type == DEV_3D)
disable_file_or_dir(dev[i].dev_fname);
i++;
}
}
void fs_dev_disable_tv(void) {
int i = 0;
while (dev[i].dev_fname != NULL) {
if (dev[i].type == DEV_TV)
disable_file_or_dir(dev[i].dev_fname);
i++;
}
}
void fs_dev_disable_dvd(void) {
int i = 0;
while (dev[i].dev_fname != NULL) {
if (dev[i].type == DEV_DVD)
disable_file_or_dir(dev[i].dev_fname);
i++;
}
}
void fs_dev_disable_u2f(void) {
int i = 0;
while (dev[i].dev_fname != NULL) {
if (dev[i].type == DEV_U2F)
disable_file_or_dir(dev[i].dev_fname);
i++;
}
}
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