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

469 lines
17 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 "ostree-libarchive-private.h"
#include "otutil.h"
#include <sys/mount.h>
#include <sys/stat.h>
#include <string.h>
#define SECURE_EXECUTION_SYSFS_FLAG "/sys/firmware/uv/prot_virt_guest"
#define SECURE_EXECUTION_PARTITION "/dev/disk/by-label/se"
#define SECURE_EXECUTION_MOUNTPOINT "/sysroot/se"
#define SECURE_EXECUTION_BOOT_IMAGE SECURE_EXECUTION_MOUNTPOINT "/sdboot"
#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_BOOT_KEY "/etc/luks/boot"
#define SECURE_EXECUTION_LUKS_CONFIG "/etc/crypttab"
#if !(defined HAVE_LIBARCHIVE) && defined(__s390x__)
#error libarchive is required for s390x
#endif
/* 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_secure_execution_mount(GError **error)
{
const char *device = realpath (SECURE_EXECUTION_PARTITION, NULL);
if (device == NULL)
return glnx_throw_errno_prefix(error, "s390x SE: resolving %s", SECURE_EXECUTION_PARTITION);
if (mount (device, SECURE_EXECUTION_MOUNTPOINT, "ext4", 0, NULL) < 0)
return glnx_throw_errno_prefix (error, "s390x SE: Mounting %s", device);
return TRUE;
}
static gboolean
_ostree_secure_execution_umount(GError **error)
{
if (umount (SECURE_EXECUTION_MOUNTPOINT) < 0)
return glnx_throw_errno_prefix (error, "s390x SE: Unmounting %s", SECURE_EXECUTION_MOUNTPOINT);
return TRUE;
}
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_is_enabled (gboolean *out_enabled,
GCancellable *cancellable,
GError **error)
{
*out_enabled = FALSE;
glnx_autofd int fd = -1;
if (!ot_openat_ignore_enoent (AT_FDCWD, SECURE_EXECUTION_SYSFS_FLAG, &fd, error))
return FALSE;
if (fd == -1)
return TRUE; //ENOENT --> SecureExecution is disabled
g_autofree char *data = glnx_fd_readall_utf8 (fd, NULL, cancellable, error);
if (!data)
return FALSE;
*out_enabled = strstr (data, "1") != NULL;
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_CONFIG, F_OK) == 0 &&
access(SECURE_EXECUTION_LUKS_ROOT_KEY, F_OK) == 0 &&
access(SECURE_EXECUTION_LUKS_BOOT_KEY, F_OK) == 0);
}
static gboolean
_ostree_secure_execution_append_luks_keys (int initrd_fd,
GCancellable *cancellable,
GError **error)
{
#ifdef HAVE_LIBARCHIVE
// appending cpio gzip archive with LUKS keys
g_autoptr(OtAutoArchiveWrite) a = archive_write_new ();
g_assert (a != NULL);
if (archive_write_set_format_cpio_newc (a) != 0 ||
archive_write_add_filter_gzip (a) != 0 ||
archive_write_open_fd(a, initrd_fd) != 0)
return glnx_prefix_error (error, "s390x SE: initing cpio: %s", archive_error_string (a));
const char *files[] = {"/etc", "/etc/luks", SECURE_EXECUTION_LUKS_CONFIG, SECURE_EXECUTION_LUKS_BOOT_KEY, SECURE_EXECUTION_LUKS_ROOT_KEY};
for (uint i = 0; i != G_N_ELEMENTS (files); ++i)
{
const char *path = files[i];
struct stat st;
if (stat(path, &st) != 0)
glnx_throw_errno_prefix (error, "s390x SE: stat(%s) failed", path);
g_autoptr(OtArchiveEntry) ae = archive_entry_new ();
g_assert (ae != NULL);
archive_entry_copy_stat (ae, &st);
archive_entry_set_pathname (ae, path);
if (archive_write_header (a, ae) != 0)
glnx_prefix_error (error, "s390x SE: writing cpio header: %s", archive_error_string (a));
if (S_ISREG (st.st_mode))
{
ot_journal_print(LOG_INFO, "s390x SE: appending %s to initrd", path);
glnx_autofd int fd = -1;
if (!glnx_openat_rdonly (AT_FDCWD, path, TRUE, &fd, error))
return glnx_prefix_error (error, "s390x SE: opening %s", path);
g_autoptr(GBytes) data = glnx_fd_readall_bytes (fd, cancellable, error);
if (!data)
return glnx_prefix_error (error, "s390x SE: reading %s", path);
gsize size = 0;
const char *ptr = (const char *) g_bytes_get_data (data, &size);
ssize_t written = archive_write_data (a, ptr, size);
if (written == -1)
return glnx_prefix_error (error, "s390x SE: writing cpio entry: %s", archive_error_string (a));
if (written != size)
return glnx_prefix_error (error, "s390x SE: writing cpio entry %zd != %zu", written, size);
}
}
ot_journal_print(LOG_INFO, "s390x SE: luks keys added to initrd");
return TRUE;
#else
return glnx_throw (error, "'libarchive' is required for s390x");
#endif
}
static gboolean
_ostree_secure_execution_generate_initrd (const gchar *initrd,
GLnxTmpfile *out_initrd,
GCancellable *cancellable,
GError **error)
{
if (!_ostree_secure_execution_luks_key_exists ())
return glnx_throw (error, "s390x SE: missing luks keys and config");
if (!glnx_open_anonymous_tmpfile (O_RDWR | O_CLOEXEC, out_initrd, error))
return glnx_prefix_error (error, "s390x SE: opening new ramdisk");
{
glnx_autofd int fd = -1;
if (!glnx_openat_rdonly (AT_FDCWD, initrd, TRUE, &fd, error))
return glnx_prefix_error (error, "s390x SE: opening initrd");
if (glnx_regfile_copy_bytes (fd, out_initrd->fd, (off_t) -1) < 0)
return glnx_throw_errno_prefix (error, "s390x SE: copying ramdisk");
}
return _ostree_secure_execution_append_luks_keys (out_initrd->fd, cancellable, error);
}
static gboolean
_ostree_secure_execution_generate_sdboot (gchar *vmlinuz,
gchar *initramfs,
gchar *options,
GPtrArray *keys,
GCancellable *cancellable,
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: writing 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 keys & config into it
g_auto(GLnxTmpfile) ramdisk = { 0, };
if (!_ostree_secure_execution_generate_initrd (initramfs, &ramdisk, cancellable, error))
return FALSE;
g_autofree gchar *ramdisk_filename = g_strdup_printf ("/proc/%d/fd/%d", self, ramdisk.fd);
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);
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", SECURE_EXECUTION_MOUNTPOINT, "-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: `sdboot` 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_mount (error) &&
_ostree_secure_execution_get_bls_config (self, bootversion, &vmlinuz, &initramfs, &options, cancellable, error) &&
_ostree_secure_execution_generate_sdboot (vmlinuz, initramfs, options, keys, cancellable, error) &&
_ostree_secure_execution_call_zipl (error) &&
_ostree_secure_execution_umount (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 */
gboolean se_enabled = FALSE;
if ( !_ostree_secure_execution_is_enabled (&se_enabled, cancellable, error))
return FALSE;
if (se_enabled)
{
g_autoptr(GPtrArray) keys = NULL;
if (!_ostree_secure_execution_get_keys (&keys, cancellable, error))
return FALSE;
if (!keys || keys->len == 0)
return glnx_throw (error, "s390x SE: no keys");
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;
}