void join(pid_t pid, int argc, char **argv, int index) {
EUID_ASSERT();
char *homedir = cfg.homedir;
extract_command(argc, argv, index);
signal (SIGTERM, signal_handler);
// if the pid is that of a firejail process, use the pid of the first child process
EUID_ROOT();
char *comm = pid_proc_comm(pid);
EUID_USER();
if (comm) {
if (strcmp(comm, "firejail") == 0) {
pid_t child;
if (find_child(pid, &child) == 0) {
pid = child;
printf("Switching to pid %u, the first child process inside the sandbox\n", (unsigned) pid);
}
}
free(comm);
}
// check privileges for non-root users
uid_t uid = getuid();
if (uid != 0) {
uid_t sandbox_uid = pid_get_uid(pid);
if (uid != sandbox_uid) {
fprintf(stderr, "Error: permission is denied to join a sandbox created by a different user.\n");
exit(1);
}
}
EUID_ROOT();
// in user mode set caps seccomp, cpu, cgroup, etc
if (getuid() != 0) {
extract_caps_seccomp(pid);
extract_cpu(pid);
extract_cgroup(pid);
extract_nogroups(pid);
extract_user_namespace(pid);
}
// set cgroup
if (cfg.cgroup) // not available for uid 0
set_cgroup(cfg.cgroup);
// join namespaces
if (arg_join_network) {
if (join_namespace(pid, "net"))
exit(1);
}
else if (arg_join_filesystem) {
if (join_namespace(pid, "mnt"))
exit(1);
}
else {
if (join_namespace(pid, "ipc"))
exit(1);
if (join_namespace(pid, "net"))
exit(1);
if (join_namespace(pid, "pid"))
exit(1);
if (join_namespace(pid, "uts"))
exit(1);
if (join_namespace(pid, "mnt"))
exit(1);
}
pid_t child = fork();
if (child < 0)
errExit("fork");
if (child == 0) {
// chroot into /proc/PID/root directory
char *rootdir;
if (asprintf(&rootdir, "/proc/%d/root", pid) == -1)
errExit("asprintf");
int rv;
if (!arg_join_network) {
rv = chroot(rootdir); // this will fail for processes in sandboxes not started with --chroot option
if (rv == 0)
printf("changing root to %s\n", rootdir);
}
prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); // kill the child in case the parent died
if (chdir("/") < 0)
errExit("chdir");
if (homedir) {
struct stat s;
if (stat(homedir, &s) == 0) {
/* coverity[toctou] */
if (chdir(homedir) < 0)
errExit("chdir");
}
}
// set cpu affinity
if (cfg.cpus) // not available for uid 0
set_cpu_affinity();
// set caps filter
if (apply_caps == 1) // not available for uid 0
caps_set(caps);
#ifdef HAVE_SECCOMP
// set protocol filter
if (getuid() != 0)
protocol_filter_load(RUN_PROTOCOL_CFG);
if (cfg.protocol) { // not available for uid 0
protocol_filter();
}
// set seccomp filter
if (apply_seccomp == 1) // not available for uid 0
seccomp_set();
#endif
// fix qt 4.8
if (setenv("QT_X11_NO_MITSHM", "1", 1) < 0)
errExit("setenv");
if (setenv("container", "firejail", 1) < 0) // LXC sets container=lxc,
errExit("setenv");
// mount user namespace or drop privileges
if (arg_noroot) { // not available for uid 0
if (arg_debug)
printf("Joining user namespace\n");
if (join_namespace(1, "user"))
exit(1);
// user namespace resets capabilities
// set caps filter
if (apply_caps == 1) // not available for uid 0
caps_set(caps);
}
else
drop_privs(arg_nogroups); // nogroups not available for uid 0
// set prompt color to green
char *prompt = getenv("FIREJAIL_PROMPT");
if (prompt && strcmp(prompt, "yes") == 0) {
//export PS1='\[\e[1;32m\][\u@\h \W]\$\[\e[0m\] '
if (setenv("PROMPT_COMMAND", "export PS1=\"\\[\\e[1;32m\\][\\u@\\h \\W]\\$\\[\\e[0m\\] \"", 1) < 0)
errExit("setenv");
}
// set nice
if (arg_nice) {
errno = 0;
int rv = nice(cfg.nice);
(void) rv;
if (errno) {
fprintf(stderr, "Warning: cannot set nice value\n");
errno = 0;
}
}
// run cmdline trough shell
if (cfg.command_line == NULL) {
// if the sandbox was started with --shell=none, it is possible we don't have a shell
// inside the sandbox
if (cfg.shell == NULL) {
cfg.shell = guess_shell();
if (!cfg.shell) {
fprintf(stderr, "Error: no POSIX shell found, please use --shell command line option\n");
exit(1);
}
}
struct stat s;
if (stat(cfg.shell, &s) == -1) {
fprintf(stderr, "Error: %s shell not found inside the sandbox\n", cfg.shell);
exit(1);
}
cfg.command_line = cfg.shell;
cfg.window_title = cfg.shell;
}
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");
}
}
}
start_application();
// it will never get here!!!
}
// wait for the child to finish
waitpid(child, NULL, 0);
flush_stdin();
exit(0);
}
void join(pid_t pid, int argc, char **argv, int index) {
EUID_ASSERT();
char *homedir = cfg.homedir;
extract_command(argc, argv, index);
// if the pid is that of a firejail process, use the pid of the first child process
EUID_ROOT();
char *comm = pid_proc_comm(pid);
EUID_USER();
if (comm) {
if (strcmp(comm, "firejail") == 0) {
pid_t child;
if (find_child(pid, &child) == 0) {
pid = child;
printf("Switching to pid %u, the first child process inside the sandbox\n", (unsigned) pid);
}
}
free(comm);
}
// check privileges for non-root users
uid_t uid = getuid();
if (uid != 0) {
uid_t sandbox_uid = pid_get_uid(pid);
if (uid != sandbox_uid) {
fprintf(stderr, "Error: permission is denied to join a sandbox created by a different user.\n");
exit(1);
}
}
EUID_ROOT();
// in user mode set caps seccomp, cpu, cgroup, etc
if (getuid() != 0) {
extract_caps_seccomp(pid);
extract_cpu(pid);
extract_cgroup(pid);
extract_nogroups(pid);
extract_user_namespace(pid);
}
// set cgroup
if (cfg.cgroup) // not available for uid 0
set_cgroup(cfg.cgroup);
// join namespaces
if (arg_join_network) {
if (join_namespace(pid, "net"))
exit(1);
}
else if (arg_join_filesystem) {
if (join_namespace(pid, "mnt"))
exit(1);
}
else {
if (join_namespace(pid, "ipc"))
exit(1);
if (join_namespace(pid, "net"))
exit(1);
if (join_namespace(pid, "pid"))
exit(1);
if (join_namespace(pid, "uts"))
exit(1);
if (join_namespace(pid, "mnt"))
exit(1);
}
pid_t child = fork();
if (child < 0)
errExit("fork");
if (child == 0) {
// chroot into /proc/PID/root directory
char *rootdir;
if (asprintf(&rootdir, "/proc/%d/root", pid) == -1)
errExit("asprintf");
int rv;
if (!arg_join_network) {
rv = chroot(rootdir); // this will fail for processes in sandboxes not started with --chroot option
if (rv == 0)
printf("changing root to %s\n", rootdir);
}
prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); // kill the child in case the parent died
if (chdir("/") < 0)
errExit("chdir");
if (homedir) {
struct stat s;
if (stat(homedir, &s) == 0) {
/* coverity[toctou] */
if (chdir(homedir) < 0)
errExit("chdir");
}
}
// set cpu affinity
if (cfg.cpus) // not available for uid 0
set_cpu_affinity();
// set caps filter
if (apply_caps == 1) // not available for uid 0
caps_set(caps);
#ifdef HAVE_SECCOMP
// set protocol filter
if (getuid() != 0)
protocol_filter_load(RUN_PROTOCOL_CFG);
if (cfg.protocol) { // not available for uid 0
protocol_filter();
}
// set seccomp filter
if (apply_seccomp == 1) // not available for uid 0
seccomp_set();
#endif
// fix qt 4.8
if (setenv("QT_X11_NO_MITSHM", "1", 1) < 0)
errExit("setenv");
if (setenv("container", "firejail", 1) < 0) // LXC sets container=lxc,
errExit("setenv");
// mount user namespace or drop privileges
if (arg_noroot) { // not available for uid 0
if (arg_debug)
printf("Joining user namespace\n");
if (join_namespace(1, "user"))
exit(1);
}
else
drop_privs(arg_nogroups); // nogroups not available for uid 0
// set prompt color to green
//export PS1='\[\e[1;32m\][\u@\h \W]\$\[\e[0m\] '
if (setenv("PROMPT_COMMAND", "export PS1=\"\\[\\e[1;32m\\][\\u@\\h \\W]\\$\\[\\e[0m\\] \"", 1) < 0)
errExit("setenv");
// run cmdline trough /bin/bash
if (cfg.command_line == NULL) {
struct stat s;
// replace the process with a shell
if (stat("/bin/bash", &s) == 0)
execlp("/bin/bash", "/bin/bash", NULL);
else if (stat("/usr/bin/zsh", &s) == 0)
execlp("/usr/bin/zsh", "/usr/bin/zsh", NULL);
else if (stat("/bin/csh", &s) == 0)
execlp("/bin/csh", "/bin/csh", NULL);
else if (stat("/bin/sh", &s) == 0)
execlp("/bin/sh", "/bin/sh", NULL);
// no shell found, print an error and exit
fprintf(stderr, "Error: no POSIX shell found\n");
sleep(5);
exit(1);
}
else {
// run the command supplied by the user
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) {
if (chdir(cfg.homedir) < 0)
errExit("chdir");
}
}
}
char *arg[5];
arg[0] = "/bin/bash";
arg[1] = "-c";
if (arg_debug)
printf("Starting %s\n", cfg.command_line);
if (!arg_doubledash) {
arg[2] = cfg.command_line;
arg[3] = NULL;
}
else {
arg[2] = "--";
arg[3] = cfg.command_line;
arg[4] = NULL;
}
execvp("/bin/bash", arg);
}
// it will never get here!!!
}
// wait for the child to finish
waitpid(child, NULL, 0);
exit(0);
}
void join(pid_t pid, int argc, char **argv, int index) {
EUID_ASSERT();
pid_t parent = pid;
// in case the pid is that of a firejail process, use the pid of the first child process
pid = switch_to_child(pid);
// now check if the pid belongs to a firejail sandbox
if (invalid_sandbox(pid)) {
fprintf(stderr, "Error: no valid sandbox\n");
exit(1);
}
// check privileges for non-root users
uid_t uid = getuid();
if (uid != 0) {
uid_t sandbox_uid = pid_get_uid(pid);
if (uid != sandbox_uid) {
fprintf(stderr, "Error: permission is denied to join a sandbox created by a different user.\n");
exit(1);
}
}
extract_x11_display(parent);
EUID_ROOT();
// in user mode set caps seccomp, cpu, cgroup, etc
if (getuid() != 0) {
extract_nonewprivs(pid); // redundant on Linux >= 4.10; duplicated in function extract_caps
extract_caps(pid);
extract_cpu(pid);
extract_cgroup(pid);
extract_nogroups(pid);
extract_user_namespace(pid);
}
// set cgroup
if (cfg.cgroup) // not available for uid 0
set_cgroup(cfg.cgroup);
// set umask, also uid 0
extract_umask(pid);
// join namespaces
if (arg_join_network) {
if (join_namespace(pid, "net"))
exit(1);
}
else if (arg_join_filesystem) {
if (join_namespace(pid, "mnt"))
exit(1);
}
else {
if (join_namespace(pid, "ipc") ||
join_namespace(pid, "net") ||
join_namespace(pid, "pid") ||
join_namespace(pid, "uts") ||
join_namespace(pid, "mnt"))
exit(1);
}
pid_t child = fork();
if (child < 0)
errExit("fork");
if (child == 0) {
// drop discretionary access control capabilities for root sandboxes
caps_drop_dac_override();
// chroot into /proc/PID/root directory
char *rootdir;
if (asprintf(&rootdir, "/proc/%d/root", pid) == -1)
errExit("asprintf");
int rv;
if (!arg_join_network) {
rv = chroot(rootdir); // this will fail for processes in sandboxes not started with --chroot option
if (rv == 0)
printf("changing root to %s\n", rootdir);
}
EUID_USER();
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 caps filter
EUID_ROOT();
if (apply_caps == 1) // not available for uid 0
caps_set(caps);
#ifdef HAVE_SECCOMP
if (getuid() != 0)
seccomp_load_file_list();
#endif
// mount user namespace or drop privileges
if (arg_noroot) { // not available for uid 0
if (arg_debug)
printf("Joining user namespace\n");
if (join_namespace(1, "user"))
exit(1);
// user namespace resets capabilities
// set caps filter
if (apply_caps == 1) // not available for uid 0
caps_set(caps);
}
// set nonewprivs
if (arg_nonewprivs == 1) { // not available for uid 0
int rv = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
if (arg_debug && rv == 0)
printf("NO_NEW_PRIVS set\n");
}
EUID_USER();
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");
}
}
}
// drop privileges
drop_privs(arg_nogroups);
// kill the child in case the parent died
prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
extract_command(argc, argv, index);
if (cfg.command_line == NULL) {
assert(cfg.shell);
cfg.command_line = cfg.shell;
cfg.window_title = cfg.shell;
}
if (arg_debug)
printf("Extracted command #%s#\n", cfg.command_line);
// set cpu affinity
if (cfg.cpus) // not available for uid 0
set_cpu_affinity();
// set nice value
if (arg_nice)
set_nice(cfg.nice);
// add x11 display
if (display) {
char *display_str;
if (asprintf(&display_str, ":%d", display) == -1)
errExit("asprintf");
setenv("DISPLAY", display_str, 1);
free(display_str);
}
start_application(0, NULL);
// it will never get here!!!
}
int status = 0;
//*****************************
// following code is signal-safe
install_handler();
// wait for the child to finish
waitpid(child, &status, 0);
// restore default signal action
signal(SIGTERM, SIG_DFL);
// end of signal-safe code
//*****************************
flush_stdin();
if (WIFEXITED(status)) {
status = WEXITSTATUS(status);
} else if (WIFSIGNALED(status)) {
status = WTERMSIG(status);
} else {
status = 0;
}
exit(status);
}
void join(pid_t pid, int argc, char **argv, int index) {
EUID_ASSERT();
char *homedir = cfg.homedir;
extract_command(argc, argv, index);
signal (SIGTERM, signal_handler);
// if the pid is that of a firejail process, use the pid of the first child process
EUID_ROOT();
char *comm = pid_proc_comm(pid);
EUID_USER();
if (comm) {
if (strcmp(comm, "firejail") == 0) {
pid_t child;
if (find_child(pid, &child) == 0) {
pid = child;
printf("Switching to pid %u, the first child process inside the sandbox\n", (unsigned) pid);
}
}
free(comm);
}
// check privileges for non-root users
uid_t uid = getuid();
if (uid != 0) {
uid_t sandbox_uid = pid_get_uid(pid);
if (uid != sandbox_uid) {
fprintf(stderr, "Error: permission is denied to join a sandbox created by a different user.\n");
exit(1);
}
}
EUID_ROOT();
// in user mode set caps seccomp, cpu, cgroup, etc
if (getuid() != 0) {
extract_caps_seccomp(pid);
extract_cpu(pid);
extract_cgroup(pid);
extract_nogroups(pid);
extract_user_namespace(pid);
}
// set cgroup
if (cfg.cgroup) // not available for uid 0
set_cgroup(cfg.cgroup);
// join namespaces
if (arg_join_network) {
if (join_namespace(pid, "net"))
exit(1);
}
else if (arg_join_filesystem) {
if (join_namespace(pid, "mnt"))
exit(1);
}
else {
if (join_namespace(pid, "ipc") ||
join_namespace(pid, "net") ||
join_namespace(pid, "pid") ||
join_namespace(pid, "uts") ||
join_namespace(pid, "mnt"))
exit(1);
}
pid_t child = fork();
if (child < 0)
errExit("fork");
if (child == 0) {
// chroot into /proc/PID/root directory
char *rootdir;
if (asprintf(&rootdir, "/proc/%d/root", pid) == -1)
errExit("asprintf");
int rv;
if (!arg_join_network) {
rv = chroot(rootdir); // this will fail for processes in sandboxes not started with --chroot option
if (rv == 0)
printf("changing root to %s\n", rootdir);
}
prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); // kill the child in case the parent died
if (chdir("/") < 0)
errExit("chdir");
if (homedir) {
struct stat s;
if (stat(homedir, &s) == 0) {
/* coverity[toctou] */
if (chdir(homedir) < 0)
errExit("chdir");
}
}
// set cpu affinity
if (cfg.cpus) // not available for uid 0
set_cpu_affinity();
// set caps filter
if (apply_caps == 1) // not available for uid 0
caps_set(caps);
#ifdef HAVE_SECCOMP
// read cfg.protocol from file
if (getuid() != 0)
protocol_filter_load(RUN_PROTOCOL_CFG);
if (cfg.protocol) { // not available for uid 0
seccomp_load(RUN_SECCOMP_PROTOCOL); // install filter
}
// set seccomp filter
if (apply_seccomp == 1) // not available for uid 0
seccomp_load(RUN_SECCOMP_CFG);
#endif
// mount user namespace or drop privileges
if (arg_noroot) { // not available for uid 0
if (arg_debug)
printf("Joining user namespace\n");
if (join_namespace(1, "user"))
exit(1);
// user namespace resets capabilities
// set caps filter
if (apply_caps == 1) // not available for uid 0
caps_set(caps);
}
else
drop_privs(arg_nogroups); // nogroups not available for uid 0
// set nice
if (arg_nice) {
errno = 0;
int rv = nice(cfg.nice);
(void) rv;
if (errno) {
fprintf(stderr, "Warning: cannot set nice value\n");
errno = 0;
}
}
env_defaults();
if (cfg.command_line == NULL) {
assert(cfg.shell);
cfg.command_line = cfg.shell;
cfg.window_title = cfg.shell;
}
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");
}
}
}
start_application();
// it will never get here!!!
}
// wait for the child to finish
waitpid(child, NULL, 0);
flush_stdin();
exit(0);
}
void join(pid_t pid, const char *homedir, int argc, char **argv, int index) {
extract_command(argc, argv, index);
// if the pid is that of a firejail process, use the pid of the first child process
char *comm = pid_proc_comm(pid);
if (comm) {
// remove \n
char *ptr = strchr(comm, '\n');
if (ptr)
*ptr = '\0';
if (strcmp(comm, "firejail") == 0) {
pid_t child;
if (find_child(pid, &child) == 0) {
pid = child;
printf("Switching to pid %u, the first child process inside the sandbox\n", (unsigned) pid);
}
}
free(comm);
}
// check privileges for non-root users
uid_t uid = getuid();
if (uid != 0) {
uid_t sandbox_uid = pid_get_uid(pid);
if (uid != sandbox_uid) {
exechelp_logerrv("firejail", FIREJAIL_ERROR, "Error: permission is denied to join a sandbox created by a different user.\n");
exit(1);
}
}
// in user mode set caps seccomp, cpu, cgroup, etc
if (getuid() != 0) {
extract_caps_seccomp(pid);
extract_cpu(pid);
extract_cgroup(pid);
extract_nogroups(pid);
extract_user_namespace(pid);
}
// set cgroup
if (cfg.cgroup)
set_cgroup(cfg.cgroup);
// join namespaces
if (join_namespace(pid, "ipc"))
exit(1);
if (join_namespace(pid, "net"))
exit(1);
if (join_namespace(pid, "pid"))
exit(1);
if (join_namespace(pid, "uts"))
exit(1);
if (join_namespace(pid, "mnt"))
exit(1);
pid_t child = fork();
if (child < 0)
errExit("fork");
if (child == 0) {
// chroot into /proc/PID/root directory
char *rootdir;
if (asprintf(&rootdir, "/proc/%d/root", pid) == -1)
errExit("asprintf");
int rv = chroot(rootdir); // this will fail for processes in sandboxes not started with --chroot option
if (rv == 0)
printf("changing root to %s\n", rootdir);
prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); // kill the child in case the parent died
if (chdir("/") < 0)
errExit("chdir");
if (homedir) {
struct stat s;
if (stat(homedir, &s) == 0) {
/* coverity[toctou] */
if (chdir(homedir) < 0)
errExit("chdir");
}
}
// set cpu affinity
if (cfg.cpus)
set_cpu_affinity();
// set caps filter
if (apply_caps == 1)
caps_set(caps);
#ifdef HAVE_SECCOMP
// set seccomp filter
if (apply_seccomp == 1)
seccomp_set();
#endif
/* We then load the variables that the original Firejail instance applied
* to the original Firejail client whose namespace we're joining. */
load_domain_env_from_chroot_proc();
// mount user namespace or drop privileges
if (arg_noroot) {
if (arg_debug)
printf("Joining user namespace\n");
if (join_namespace(1, "user"))
exit(1);
}
else
drop_privs(arg_nogroups);
// set prompt color to green
//export PS1='\[\e[1;32m\][\u@\h \W]\$\[\e[0m\] '
if (setenv("PROMPT_COMMAND", "export PS1=\"\\[\\e[1;32m\\][\\u@\\h \\W]\\$\\[\\e[0m\\] \"", 1) < 0)
errExit("setenv");
// run icmdline trough /bin/bash
if (cfg.command_line == NULL)
// replace the process with a regular bash session
execlp("/bin/bash", "/bin/bash", NULL);
else {
// run the command supplied by the user
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) {
if (chdir(cfg.homedir) < 0)
errExit("chdir");
}
}
}
char *arg[5];
arg[0] = "/bin/bash";
arg[1] = "-c";
if (arg_debug)
printf("Starting %s\n", cfg.command_line);
exechelp_logv("firejail", "Starting %s in sandbox %d\n", cfg.command_line, pid);
if (!arg_doubledash) {
arg[2] = cfg.command_line;
arg[3] = NULL;
}
else {
arg[2] = "--";
arg[3] = cfg.command_line;
arg[4] = NULL;
}
execvp("/bin/bash", arg);
}
// it will never get here!!!
}
// wait for the child to finish
waitpid(child, NULL, 0);
exit(0);
}