ostree/src/libostree/ostree-bootloader-zipl.c

364 lines
13 KiB
C

/*
* Copyright (C) 2019 Colin Walters <walters@verbum.org>
*
* 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 of the licence 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 <https://www.gnu.org/licenses/>.
*/
#include "config.h"
#include "ostree-sysroot-private.h"
#include "ostree-bootloader-zipl.h"
#include "ostree-deployment-private.h"
#include "otutil.h"
#include <string.h>
#define SECURE_EXECUTION_BOOT_IMAGE "/boot/sd-boot"
#define SECURE_EXECUTION_HOSTKEY_PATH "/etc/se-hostkeys/"
#define SECURE_EXECUTION_HOSTKEY_PREFIX "ibm-z-hostkey"
#define SECURE_EXECUTION_LUKS_ROOT_KEY "/etc/luks/root"
#define SECURE_EXECUTION_LUKS_CONFIG "/etc/crypttab"
#define SECURE_EXECUTION_RAMDISK_TOOL PKGLIBEXECDIR "/s390x-se-luks-gencpio"
/* This is specific to zipl today, but in the future we could also
* use it for the grub2-mkconfig case.
*/
static const char zipl_requires_execute_path[] = "boot/ostree-bootloader-update.stamp";
struct _OstreeBootloaderZipl
{
GObject parent_instance;
OstreeSysroot *sysroot;
};
typedef GObjectClass OstreeBootloaderZiplClass;
static void _ostree_bootloader_zipl_bootloader_iface_init (OstreeBootloaderInterface *iface);
G_DEFINE_TYPE_WITH_CODE (OstreeBootloaderZipl, _ostree_bootloader_zipl, G_TYPE_OBJECT,
G_IMPLEMENT_INTERFACE (OSTREE_TYPE_BOOTLOADER, _ostree_bootloader_zipl_bootloader_iface_init));
static gboolean
_ostree_bootloader_zipl_query (OstreeBootloader *bootloader,
gboolean *out_is_active,
GCancellable *cancellable,
GError **error)
{
/* We don't auto-detect this one; should be explicitly chosen right now.
* see also https://github.com/coreos/coreos-assembler/pull/849
*/
*out_is_active = FALSE;
return TRUE;
}
static const char *
_ostree_bootloader_zipl_get_name (OstreeBootloader *bootloader)
{
return "zipl";
}
static gboolean
_ostree_bootloader_zipl_write_config (OstreeBootloader *bootloader,
int bootversion,
GPtrArray *new_deployments,
GCancellable *cancellable,
GError **error)
{
OstreeBootloaderZipl *self = OSTREE_BOOTLOADER_ZIPL (bootloader);
/* Write our stamp file */
if (!glnx_file_replace_contents_at (self->sysroot->sysroot_fd, zipl_requires_execute_path,
(guint8*)"", 0, GLNX_FILE_REPLACE_NODATASYNC,
cancellable, error))
return FALSE;
return TRUE;
}
static gboolean
_ostree_secure_execution_get_keys (GPtrArray **keys,
GCancellable *cancellable,
GError **error)
{
g_auto (GLnxDirFdIterator) it = { 0,};
if ( !glnx_dirfd_iterator_init_at (-1, SECURE_EXECUTION_HOSTKEY_PATH, TRUE, &it, error))
return glnx_prefix_error (error, "s390x SE: looking for SE keys");
g_autoptr(GPtrArray) ret_keys = g_ptr_array_new_with_free_func (g_free);
while (TRUE)
{
struct dirent *dent = NULL;
if (!glnx_dirfd_iterator_next_dent (&it, &dent, cancellable, error))
return FALSE;
if (!dent)
break;
if (g_str_has_prefix (dent->d_name, SECURE_EXECUTION_HOSTKEY_PREFIX))
g_ptr_array_add (ret_keys, g_build_filename (SECURE_EXECUTION_HOSTKEY_PATH, dent->d_name, NULL));
}
*keys = g_steal_pointer (&ret_keys);
return TRUE;
}
static gboolean
_ostree_secure_execution_get_bls_config (OstreeBootloaderZipl *self,
int bootversion,
gchar **vmlinuz,
gchar **initramfs,
gchar **options,
GCancellable *cancellable,
GError **error)
{
g_autoptr (GPtrArray) configs = NULL;
if ( !_ostree_sysroot_read_boot_loader_configs (self->sysroot, bootversion, &configs, cancellable, error))
return glnx_prefix_error (error, "s390x SE: loading bls configs");
if (!configs || configs->len == 0)
return glnx_throw (error, "s390x SE: no bls config");
OstreeBootconfigParser *parser = (OstreeBootconfigParser *) g_ptr_array_index (configs, 0);
const gchar *val = NULL;
val = ostree_bootconfig_parser_get (parser, "linux");
if (!val)
return glnx_throw (error, "s390x SE: no \"linux\" key in bootloader config");
*vmlinuz = g_build_filename ("/boot", val, NULL);
val = ostree_bootconfig_parser_get (parser, "initrd");
if (!val)
return glnx_throw (error, "s390x SE: no \"initrd\" key in bootloader config");
*initramfs = g_build_filename ("/boot", val, NULL);
val = ostree_bootconfig_parser_get (parser, "options");
if (!val)
return glnx_throw (error, "s390x SE: no \"options\" key in bootloader config");
*options = g_strdup(val);
return TRUE;
}
static gboolean
_ostree_secure_execution_luks_key_exists (void)
{
return (access(SECURE_EXECUTION_LUKS_ROOT_KEY, F_OK) == 0 &&
access(SECURE_EXECUTION_LUKS_CONFIG, F_OK) == 0);
}
static gboolean
_ostree_secure_execution_enable_luks(const gchar *oldramfs,
const gchar *newramfs,
GError **error)
{
const char *const argv[] = {SECURE_EXECUTION_RAMDISK_TOOL, oldramfs, newramfs, NULL};
g_autofree gchar *out = NULL;
g_autofree gchar *err = NULL;
int status = 0;
if (!g_spawn_sync (NULL, (char**)argv, NULL, G_SPAWN_SEARCH_PATH,
NULL, NULL, &out, &err, &status, error))
return glnx_prefix_error(error, "s390x SE: spawning %s", SECURE_EXECUTION_RAMDISK_TOOL);
if (!g_spawn_check_exit_status (status, error))
{
g_printerr("s390x SE: `%s` stdout: %s\n", SECURE_EXECUTION_RAMDISK_TOOL, out);
g_printerr("s390x SE: `%s` stderr: %s\n", SECURE_EXECUTION_RAMDISK_TOOL, err);
return glnx_prefix_error(error, "s390x SE: `%s` failed", SECURE_EXECUTION_RAMDISK_TOOL);
}
ot_journal_print(LOG_INFO, "s390x SE: luks key added to initrd");
return TRUE;
}
static gboolean
_ostree_secure_execution_generate_sdboot (gchar *vmlinuz,
gchar *initramfs,
gchar *options,
GPtrArray *keys,
GError **error)
{
g_assert (vmlinuz && initramfs && options && keys && keys->len);
ot_journal_print(LOG_INFO, "s390x SE: kernel: %s", vmlinuz);
ot_journal_print(LOG_INFO, "s390x SE: initrd: %s", initramfs);
ot_journal_print(LOG_INFO, "s390x SE: kargs: %s", options);
pid_t self = getpid();
// Store kernel options to temp file, so `genprotimg` can later embed it
g_auto(GLnxTmpfile) cmdline = { 0, };
if (!glnx_open_anonymous_tmpfile (O_RDWR | O_CLOEXEC, &cmdline, error))
return glnx_prefix_error(error, "s390x SE: opening cmdline file");
if (glnx_loop_write (cmdline.fd, options, strlen (options)) < 0)
return glnx_throw_errno_prefix (error, "s390x SE: writting cmdline file");
g_autofree gchar *cmdline_filename = g_strdup_printf ("/proc/%d/fd/%d", self, cmdline.fd);
// Copy initramfs to temp file and embed LUKS key and config into it
g_auto(GLnxTmpfile) ramdisk = { 0, };
g_autofree gchar *ramdisk_filename = NULL;
if (_ostree_secure_execution_luks_key_exists ())
{
if (!glnx_open_anonymous_tmpfile (O_RDWR | O_CLOEXEC, &ramdisk, error))
return glnx_prefix_error(error, "s390x SE: creating new ramdisk");
ramdisk_filename = g_strdup_printf ("/proc/%d/fd/%d", self, ramdisk.fd);
if (!_ostree_secure_execution_enable_luks (initramfs, ramdisk_filename, error))
return FALSE;
}
g_autoptr(GPtrArray) argv = g_ptr_array_new ();
g_ptr_array_add (argv, "genprotimg");
g_ptr_array_add (argv, "-i");
g_ptr_array_add (argv, vmlinuz);
g_ptr_array_add (argv, "-r");
g_ptr_array_add (argv, (ramdisk_filename == NULL) ? initramfs: ramdisk_filename);
g_ptr_array_add (argv, "-p");
g_ptr_array_add (argv, cmdline_filename);
for (guint i = 0; i < keys->len; ++i)
{
gchar *key = g_ptr_array_index (keys, i);
g_ptr_array_add (argv, "-k");
g_ptr_array_add (argv, key);
ot_journal_print(LOG_INFO, "s390x SE: key[%d]: %s", i + 1, key);
}
g_ptr_array_add (argv, "--no-verify");
g_ptr_array_add (argv, "-o");
g_ptr_array_add (argv, SECURE_EXECUTION_BOOT_IMAGE);
g_ptr_array_add (argv, NULL);
gint status = 0;
if (!g_spawn_sync (NULL, (char**)argv->pdata, NULL, G_SPAWN_SEARCH_PATH,
NULL, NULL, NULL, NULL, &status, error))
return glnx_prefix_error(error, "s390x SE: spawning genprotimg");
if (!g_spawn_check_exit_status (status, error))
return glnx_prefix_error(error, "s390x SE: `genprotimg` failed");
ot_journal_print(LOG_INFO, "s390x SE: `%s` generated", SECURE_EXECUTION_BOOT_IMAGE);
return TRUE;
}
static gboolean
_ostree_secure_execution_call_zipl (GError **error)
{
int status = 0;
const char *const zipl_argv[] = {"zipl", "-V", "-t", "/boot", "-i", SECURE_EXECUTION_BOOT_IMAGE, NULL};
if (!g_spawn_sync (NULL, (char**)zipl_argv, NULL, G_SPAWN_SEARCH_PATH,
NULL, NULL, NULL, NULL, &status, error))
return glnx_prefix_error(error, "s390x SE: spawning zipl");
if (!g_spawn_check_exit_status (status, error))
return glnx_prefix_error(error, "s390x SE: `zipl` failed");
ot_journal_print(LOG_INFO, "s390x SE: `sd-boot` zipled");
return TRUE;
}
static gboolean
_ostree_secure_execution_enable (OstreeBootloaderZipl *self,
int bootversion,
GPtrArray *keys,
GCancellable *cancellable,
GError **error)
{
g_autofree gchar* vmlinuz = NULL;
g_autofree gchar* initramfs = NULL;
g_autofree gchar* options = NULL;
gboolean rc =
_ostree_secure_execution_get_bls_config (self, bootversion, &vmlinuz, &initramfs, &options, cancellable, error) &&
_ostree_secure_execution_generate_sdboot (vmlinuz, initramfs, options, keys, error) &&
_ostree_secure_execution_call_zipl (error);
return rc;
}
static gboolean
_ostree_bootloader_zipl_post_bls_sync (OstreeBootloader *bootloader,
int bootversion,
GCancellable *cancellable,
GError **error)
{
OstreeBootloaderZipl *self = OSTREE_BOOTLOADER_ZIPL (bootloader);
/* Note that unlike the grub2-mkconfig backend, we make no attempt to
* chroot().
*/
g_assert (self->sysroot->booted_deployment);
if (!glnx_fstatat_allow_noent (self->sysroot->sysroot_fd, zipl_requires_execute_path, NULL, 0, error))
return FALSE;
/* If there's no stamp file, nothing to do */
if (errno == ENOENT)
return TRUE;
/* Try with Secure Execution */
g_autoptr(GPtrArray) keys = NULL;
if (!_ostree_secure_execution_get_keys (&keys, cancellable, error))
return FALSE;
if (keys && keys->len)
return _ostree_secure_execution_enable (self, bootversion, keys, cancellable, error);
/* Fallback to non-SE setup */
const char *const zipl_argv[] = {"zipl", NULL};
int estatus;
if (!g_spawn_sync (NULL, (char**)zipl_argv, NULL, G_SPAWN_SEARCH_PATH,
NULL, NULL, NULL, NULL, &estatus, error))
return FALSE;
if (!g_spawn_check_exit_status (estatus, error))
return FALSE;
if (!glnx_unlinkat (self->sysroot->sysroot_fd, zipl_requires_execute_path, 0, error))
return FALSE;
return TRUE;
}
static void
_ostree_bootloader_zipl_finalize (GObject *object)
{
OstreeBootloaderZipl *self = OSTREE_BOOTLOADER_ZIPL (object);
g_clear_object (&self->sysroot);
G_OBJECT_CLASS (_ostree_bootloader_zipl_parent_class)->finalize (object);
}
void
_ostree_bootloader_zipl_init (OstreeBootloaderZipl *self)
{
}
static void
_ostree_bootloader_zipl_bootloader_iface_init (OstreeBootloaderInterface *iface)
{
iface->query = _ostree_bootloader_zipl_query;
iface->get_name = _ostree_bootloader_zipl_get_name;
iface->write_config = _ostree_bootloader_zipl_write_config;
iface->post_bls_sync = _ostree_bootloader_zipl_post_bls_sync;
}
void
_ostree_bootloader_zipl_class_init (OstreeBootloaderZiplClass *class)
{
GObjectClass *object_class = G_OBJECT_CLASS (class);
object_class->finalize = _ostree_bootloader_zipl_finalize;
}
OstreeBootloaderZipl *
_ostree_bootloader_zipl_new (OstreeSysroot *sysroot)
{
OstreeBootloaderZipl *self = g_object_new (OSTREE_TYPE_BOOTLOADER_ZIPL, NULL);
self->sysroot = g_object_ref (sysroot);
return self;
}