Add blkid utilities for fast detection of device signatures.

lib/utils_blkid.c

@@ -0,0 +1,158 @@
+/*
+ * blkid probe utilities
+ *
+ * Copyright (C) 2018, Red Hat, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "utils_blkid.h"
+
+#ifdef HAVE_BLKID
+#include <blkid/blkid.h>
+struct blkid_handle {
+	int fd;
+	blkid_probe pr;
+};
+#endif
+
+void blk_set_chains_for_fast_detection(struct blkid_handle *h)
+{
+#ifdef HAVE_BLKID
+	blkid_probe_enable_partitions(h->pr, 1);
+	blkid_probe_set_partitions_flags(h->pr, 0);
+
+	blkid_probe_enable_superblocks(h->pr, 1);
+	blkid_probe_set_superblocks_flags(h->pr, BLKID_SUBLKS_TYPE);
+#endif
+}
+
+int blk_init_by_path(struct blkid_handle **h, const char *path)
+{
+	int r = -ENOTSUP;
+#ifdef HAVE_BLKID
+	struct blkid_handle *tmp = malloc(sizeof(*h));
+	if (!tmp)
+		return -ENOMEM;
+
+	tmp->fd = -1;
+
+	tmp->pr = blkid_new_probe_from_filename(path);
+	if (!tmp->pr) {
+		free(tmp);
+		return -EINVAL;
+	}
+
+	*h = tmp;
+
+	r = 0;
+#endif
+	return r;
+}
+
+int blk_superblocks_filter_luks(struct blkid_handle *h)
+{
+	int r = -ENOTSUP;
+#ifdef HAVE_BLKID
+	char *luks_filter[] = {
+		"crypto_LUKS",
+		NULL
+	};
+	r = blkid_probe_filter_superblocks_type(h->pr, BLKID_FLTR_NOTIN, luks_filter);
+#endif
+	return r;
+}
+
+blk_probe_status blk_safeprobe(struct blkid_handle *h)
+{
+	int r = -1;
+#ifdef HAVE_BLKID
+	r = blkid_do_safeprobe(h->pr);
+#endif
+	switch (r) {
+	case -2:
+		return PRB_AMBIGUOUS;
+	case 1:
+		return PRB_EMPTY;
+	case 0:
+		return PRB_OK;
+	default:
+		return PRB_FAIL;
+	}
+}
+
+int blk_is_partition(struct blkid_handle *h)
+{
+	int r = 0;
+#ifdef HAVE_BLKID
+	r = blkid_probe_has_value(h->pr, "PTTYPE");
+#endif
+	return r;
+}
+
+int blk_is_superblock(struct blkid_handle *h)
+{
+	int r = 0;
+#ifdef HAVE_BLKID
+	r = blkid_probe_has_value(h->pr, "TYPE");
+#endif
+	return r;
+}
+
+const char *blk_get_partition_type(struct blkid_handle *h)
+{
+	const char *value = NULL;
+#ifdef HAVE_BLKID
+	(void) blkid_probe_lookup_value(h->pr, "PTTYPE", &value, NULL);
+#endif
+	return value;
+}
+
+const char *blk_get_superblock_type(struct blkid_handle *h)
+{
+	const char *value = NULL;
+#ifdef HAVE_BLKID
+	(void) blkid_probe_lookup_value(h->pr, "TYPE", &value, NULL);
+#endif
+	return value;
+}
+
+void blk_free(struct blkid_handle *h)
+{
+#ifdef HAVE_BLKID
+	if (!h)
+		return;
+
+	if (h->pr)
+		blkid_free_probe(h->pr);
+
+	free(h);
+#endif
+}
+
+int blk_supported(void)
+{
+	int r = 0;
+#ifdef HAVE_BLKID
+	r = 1;
+#endif
+	return r;
+}