/**
* Build supermin appliance from C<supermin_path> to
* F<$TMPDIR/.guestfs-$UID>.
*
* Returns: C<0> = built or C<-1> = error (aborts launch).
*/
static int
build_supermin_appliance (guestfs_h *g,
const char *supermin_path,
char **kernel, char **initrd,
char **appliance)
{
CLEANUP_FREE char *cachedir = NULL, *lockfile = NULL, *appliancedir = NULL;
cachedir = guestfs_int_lazy_make_supermin_appliance_dir (g);
if (cachedir == NULL)
return -1;
appliancedir = safe_asprintf (g, "%s/appliance.d", cachedir);
lockfile = safe_asprintf (g, "%s/lock", cachedir);
debug (g, "begin building supermin appliance");
/* Build the appliance if it needs to be built. */
debug (g, "run supermin");
if (run_supermin_build (g, lockfile, appliancedir, supermin_path) == -1)
return -1;
debug (g, "finished building supermin appliance");
/* Return the appliance filenames. */
*kernel = safe_asprintf (g, "%s/kernel", appliancedir);
*initrd = safe_asprintf (g, "%s/initrd", appliancedir);
*appliance = safe_asprintf (g, "%s/root", appliancedir);
/* Touch the files so they don't get deleted (as they are in /var/tmp). */
(void) utimes (*kernel, NULL);
(void) utimes (*initrd, NULL);
/* Checking backend != "uml" is a big hack. UML encodes the mtime
* of the original backing file (in this case, the appliance) in the
* COW file, and checks it when adding it to the VM. If there are
* multiple threads running and one touches the appliance here, it
* will disturb the mtime and UML will give an error.
*
* We can get rid of this hack as soon as UML fixes the
* ubdN=cow,original parsing bug, since we won't need to run
* uml_mkcow separately, so there is no possible race.
*
* XXX
*/
if (STRNEQ (g->backend, "uml"))
(void) utimes (*appliance, NULL);
return 0;
}
/* Build supermin appliance from supermin_path to $TMPDIR/.guestfs-$UID.
*
* Returns:
* 0 = built
* -1 = error (aborts launch)
*/
static int
build_supermin_appliance (guestfs_h *g,
const char *supermin_path,
uid_t uid,
char **kernel, char **dtb,
char **initrd, char **appliance)
{
CLEANUP_FREE char *tmpdir = guestfs_get_cachedir (g);
struct stat statbuf;
size_t len;
/* len must be longer than the length of any pathname we can
* generate in this function.
*/
len = strlen (tmpdir) + 128;
char cachedir[len];
snprintf (cachedir, len, "%s/.guestfs-%ju", tmpdir, (uintmax_t) uid);
char lockfile[len];
snprintf (lockfile, len, "%s/lock", cachedir);
char appliancedir[len];
snprintf (appliancedir, len, "%s/appliance.d", cachedir);
ignore_value (mkdir (cachedir, 0755));
ignore_value (chmod (cachedir, 0755)); /* RHBZ#921292 */
/* See if the cache directory exists and passes some simple checks
* to make sure it has not been tampered with.
*/
if (lstat (cachedir, &statbuf) == -1)
return 0;
if (statbuf.st_uid != uid) {
error (g, _("security: cached appliance %s is not owned by UID %ju"),
cachedir, (uintmax_t) uid);
return -1;
}
if (!S_ISDIR (statbuf.st_mode)) {
error (g, _("security: cached appliance %s is not a directory (mode %o)"),
cachedir, statbuf.st_mode);
return -1;
}
if ((statbuf.st_mode & 0022) != 0) {
error (g, _("security: cached appliance %s is writable by group or other (mode %o)"),
cachedir, statbuf.st_mode);
return -1;
}
(void) utimes (cachedir, NULL);
if (g->verbose)
guestfs_int_print_timestamped_message (g, "begin building supermin appliance");
/* Build the appliance if it needs to be built. */
if (g->verbose)
guestfs_int_print_timestamped_message (g, "run supermin");
if (run_supermin_build (g, lockfile, appliancedir, supermin_path) == -1)
return -1;
if (g->verbose)
guestfs_int_print_timestamped_message (g, "finished building supermin appliance");
/* Return the appliance filenames. */
*kernel = safe_malloc (g, len);
#ifdef DTB_WILDCARD
*dtb = safe_malloc (g, len);
#else
*dtb = NULL;
#endif
*initrd = safe_malloc (g, len);
*appliance = safe_malloc (g, len);
snprintf (*kernel, len, "%s/kernel", appliancedir);
#ifdef DTB_WILDCARD
snprintf (*dtb, len, "%s/dtb", appliancedir);
#endif
snprintf (*initrd, len, "%s/initrd", appliancedir);
snprintf (*appliance, len, "%s/root", appliancedir);
/* Touch the files so they don't get deleted (as they are in /var/tmp). */
(void) utimes (*kernel, NULL);
#ifdef DTB_WILDCARD
(void) utimes (*dtb, NULL);
#endif
(void) utimes (*initrd, NULL);
/* Checking backend != "uml" is a big hack. UML encodes the mtime
* of the original backing file (in this case, the appliance) in the
* COW file, and checks it when adding it to the VM. If there are
* multiple threads running and one touches the appliance here, it
* will disturb the mtime and UML will give an error.
*
* We can get rid of this hack as soon as UML fixes the
* ubdN=cow,original parsing bug, since we won't need to run
* uml_mkcow separately, so there is no possible race.
*
* XXX
*/
if (STRNEQ (g->backend, "uml"))
(void) utimes (*appliance, NULL);
return 0;
}
