flatpak-builder/app/flatpak-builtins-enter.c

265 lines
8.3 KiB
C

/*
* Copyright © 2014 Red Hat, Inc
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*
* Authors:
* Alexander Larsson <alexl@redhat.com>
*/
#include "config.h"
#include <locale.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <glib/gi18n.h>
#include "libglnx/libglnx.h"
#include "flatpak-builtins.h"
#include "flatpak-utils.h"
#include "flatpak-dbus.h"
#include "flatpak-run.h"
static GOptionEntry options[] = {
{ NULL }
};
gboolean
flatpak_builtin_enter (int argc,
char **argv,
GCancellable *cancellable,
GError **error)
{
g_autoptr(GOptionContext) context = NULL;
int rest_argv_start, rest_argc;
const char *ns_name[] = { "ipc", "net", "pid", "mnt", "user" };
int ns_fd[G_N_ELEMENTS (ns_name)];
char pid_ns[256] = { 0 };
ssize_t pid_ns_len;
char self_ns[256];
ssize_t self_ns_len;
char *pid_s;
int pid, i;
g_autofree char *environment_path = NULL;
g_autoptr(GPtrArray) argv_array = NULL;
g_autoptr(GPtrArray) envp_array = NULL;
g_autofree char *environment = NULL;
gsize environment_len;
char *e;
g_autofree char *pulse_path = NULL;
g_autofree char *session_bus_path = NULL;
g_autofree char *xdg_runtime_dir = NULL;
g_autofree char *stat_path = NULL;
g_autofree char *root_path = NULL;
char root_link[256] = { 0 };
gssize root_link_len;
g_autofree char *cwd_path = NULL;
char cwd_link[256] = { 0 };
gssize cwd_link_len;
int status;
struct stat stat_buf;
uid_t uid;
gid_t gid;
context = g_option_context_new (_("SANDBOXEDPID [COMMAND [args...]] - Run a command inside a running sandbox"));
g_option_context_set_translation_domain (context, GETTEXT_PACKAGE);
rest_argc = 0;
for (i = 1; i < argc; i++)
{
/* The non-option is the command, take it out of the arguments */
if (argv[i][0] != '-')
{
rest_argv_start = i;
rest_argc = argc - i;
argc = i;
break;
}
}
if (!flatpak_option_context_parse (context, options, &argc, &argv, FLATPAK_BUILTIN_FLAG_NO_DIR, NULL, cancellable, error))
return FALSE;
if (rest_argc < 2)
{
usage_error (context, _("SANDBOXEDPID and COMMAND must be specified"), error);
return FALSE;
}
/* Before further checks, warn if we are not already root */
if (geteuid () != 0)
g_printerr ("%s\n", _("Not running as root, may be unable to enter namespace"));
pid_s = argv[rest_argv_start];
pid = atoi (pid_s);
if (pid <= 0)
return flatpak_fail (error, _("Invalid pid %s"), pid_s);
stat_path = g_strdup_printf ("/proc/%d/root", pid);
if (stat (stat_path, &stat_buf))
return flatpak_fail (error, _("No such pid %s"), pid_s);
uid = stat_buf.st_uid;
gid = stat_buf.st_gid;
environment_path = g_strdup_printf ("/proc/%d/environ", pid);
if (!g_file_get_contents (environment_path, &environment, &environment_len, error))
return FALSE;
cwd_path = g_strdup_printf ("/proc/%d/cwd", pid);
cwd_link_len = readlink (cwd_path, cwd_link, sizeof (cwd_link) - 1);
if (cwd_link_len <= 0)
return flatpak_fail (error, _("Can't read cwd"));
root_path = g_strdup_printf ("/proc/%d/root", pid);
root_link_len = readlink (root_path, root_link, sizeof (root_link) - 1);
if (root_link_len <= 0)
return flatpak_fail (error, _("Can't read root"));
for (i = 0; i < G_N_ELEMENTS (ns_name); i++)
{
g_autofree char *path = g_strdup_printf ("/proc/%d/ns/%s", pid, ns_name[i]);
g_autofree char *self_path = g_strdup_printf ("/proc/self/ns/%s", ns_name[i]);
pid_ns_len = readlink (path, pid_ns, sizeof (pid_ns) - 1);
if (pid_ns_len <= 0)
return flatpak_fail (error, _("Invalid %s namespace for pid %d"), ns_name[i], pid);
pid_ns[pid_ns_len] = 0;
self_ns_len = readlink (self_path, self_ns, sizeof (self_ns) - 1);
if (self_ns_len <= 0)
return flatpak_fail (error, _("Invalid %s namespace for self"), ns_name[i]);
self_ns[self_ns_len] = 0;
if (strcmp (self_ns, pid_ns) == 0)
{
/* No need to setns to the same namespace, it will only fail */
ns_fd[i] = -1;
}
else
{
ns_fd[i] = open (path, O_RDONLY);
if (ns_fd[i] == -1)
return flatpak_fail (error, _("Can't open %s namespace: %s"), ns_name[i], g_strerror (errno));
}
}
for (i = 0; i < G_N_ELEMENTS (ns_fd); i++)
{
if (ns_fd[i] != -1)
{
if (setns (ns_fd[i], 0) == -1)
return flatpak_fail (error, _("Can't enter %s namespace: %s"), ns_name[i], g_strerror (errno));
close (ns_fd[i]);
}
}
if (chdir (cwd_link))
return flatpak_fail (error, _("Can't chdir"));
if (chroot (root_link))
return flatpak_fail (error, _("Can't chroot"));
envp_array = g_ptr_array_new_with_free_func (g_free);
for (e = environment; e < environment + environment_len; e = e + strlen (e) + 1)
{
if (*e != 0 &&
!g_str_has_prefix (e, "DISPLAY=") &&
!g_str_has_prefix (e, "PULSE_SERVER=") &&
!g_str_has_prefix (e, "PULSE_CLIENTCONFIG=") &&
!g_str_has_prefix (e, "XDG_RUNTIME_DIR=") &&
!g_str_has_prefix (e, "DBUS_SYSTEM_BUS_ADDRESS=") &&
!g_str_has_prefix (e, "DBUS_SESSION_BUS_ADDRESS="))
{
if (g_str_has_prefix (e, "_LD_LIBRARY_PATH="))
e++;
g_ptr_array_add (envp_array, g_strdup (e));
}
}
xdg_runtime_dir = g_strdup_printf ("/run/user/%d", uid);
g_ptr_array_add (envp_array, g_strdup_printf ("XDG_RUNTIME_DIR=%s", xdg_runtime_dir));
if (g_file_test ("/tmp/.X11-unix/X99", G_FILE_TEST_EXISTS))
g_ptr_array_add (envp_array, g_strdup ("DISPLAY=:99.0"));
pulse_path = g_strdup_printf ("/run/user/%d/pulse/native", uid);
if (g_file_test (pulse_path, G_FILE_TEST_EXISTS))
{
g_ptr_array_add (envp_array, g_strdup_printf ("PULSE_SERVER=unix:%s", pulse_path));
g_ptr_array_add (envp_array, g_strdup_printf ("PULSE_CLIENTCONFIG=/run/user/%d/pulse/config", uid));
}
session_bus_path = g_strdup_printf ("/run/user/%d/bus", uid);
if (g_file_test (session_bus_path, G_FILE_TEST_EXISTS))
g_ptr_array_add (envp_array, g_strdup_printf ("DBUS_SESSION_BUS_ADDRESS=unix:%s", session_bus_path));
if (g_file_test ("/run/dbus/system_bus_socket", G_FILE_TEST_EXISTS))
g_ptr_array_add (envp_array, g_strdup ("DBUS_SYSTEM_BUS_ADDRESS=unix:/run/dbus/system_bus_socket"));
g_ptr_array_add (envp_array, NULL);
argv_array = g_ptr_array_new_with_free_func (g_free);
for (i = 1; i < rest_argc; i++)
g_ptr_array_add (argv_array, g_strdup (argv[rest_argv_start + i]));
g_ptr_array_add (argv_array, NULL);
if (setgid (gid))
return flatpak_fail (error, _("Can't switch gid"));
if (setuid (uid))
return flatpak_fail (error, _("Can't switch uid"));
if (!g_spawn_sync (NULL, (char **) argv_array->pdata, (char **) envp_array->pdata,
G_SPAWN_SEARCH_PATH_FROM_ENVP | G_SPAWN_CHILD_INHERITS_STDIN,
NULL, NULL,
NULL, NULL,
&status, error))
return FALSE;
exit (status);
}
gboolean
flatpak_complete_enter (FlatpakCompletion *completion)
{
g_autoptr(GOptionContext) context = NULL;
context = g_option_context_new ("");
if (!flatpak_option_context_parse (context, options, &completion->argc, &completion->argv, FLATPAK_BUILTIN_FLAG_NO_DIR, NULL, NULL, NULL))
return FALSE;
switch (completion->argc)
{
case 0:
case 1:
flatpak_complete_options (completion, global_entries);
flatpak_complete_options (completion, options);
break;
default:
break;
}
return TRUE;
}