From 842dacb76f2f98537554683d7cccec4710779a8a Mon Sep 17 00:00:00 2001
From: Kay Sievers <kay.sievers@vrfy.org>
Date: Thu, 2 Oct 2008 15:16:11 +0200
Subject: [PATCH] volume_id: hpfs - read label and uuid

---
 extras/volume_id/lib/hpfs.c | 67 +++++++++++++++++++++++++++++++++----
 1 file changed, 60 insertions(+), 7 deletions(-)

diff --git a/extras/volume_id/lib/hpfs.c b/extras/volume_id/lib/hpfs.c
index a59ca1d99..80ba28977 100644
--- a/extras/volume_id/lib/hpfs.c
+++ b/extras/volume_id/lib/hpfs.c
@@ -31,31 +31,84 @@
 #include "libvolume_id.h"
 #include "libvolume_id-private.h"
 
+struct hpfs_boot_block
+{
+	uint8_t		jmp[3];
+	uint8_t		oem_id[8];
+	uint8_t		bytes_per_sector[2];
+	uint8_t		sectors_per_cluster;
+	uint8_t		n_reserved_sectors[2];
+	uint8_t		n_fats;
+	uint8_t		n_rootdir_entries[2];
+	uint8_t		n_sectors_s[2];
+	uint8_t		media_byte;
+	uint16_t	sectors_per_fat;
+	uint16_t	sectors_per_track;
+	uint16_t	heads_per_cyl;
+	uint32_t	n_hidden_sectors;
+	uint32_t	n_sectors_l;
+	uint8_t		drive_number;
+	uint8_t		mbz;
+	uint8_t		sig_28h;
+	uint8_t		vol_serno[4];
+	uint8_t		vol_label[11];
+	uint8_t		sig_hpfs[8];
+	uint8_t		pad[448];
+	uint8_t		magic[2];
+} PACKED;
+
 struct hpfs_super
 {
 	uint8_t		magic[4];
+	uint8_t		magic1[4];
 	uint8_t		version;
 } PACKED;
 
+
+struct hpfs_spare_super
+{
+	uint8_t		magic[4];
+	uint8_t		magic1[4];
+} PACKED;
+
 #define HPFS_SUPERBLOCK_OFFSET			0x2000
+#define HPFS_SUPERBLOCK_SPARE_OFFSET		0x2200
 
 int volume_id_probe_hpfs(struct volume_id *id, uint64_t off, uint64_t size)
 {
 	struct hpfs_super *hs;
+	struct hpfs_spare_super *hss;
+	struct hpfs_boot_block *hbb;
 
 	info("probing at offset 0x%llx\n", (unsigned long long) off);
 
-	hs = (struct hpfs_super *) volume_id_get_buffer(id, off + HPFS_SUPERBLOCK_OFFSET, 0x200);
+	hs = (struct hpfs_super *) volume_id_get_buffer(id, off + HPFS_SUPERBLOCK_OFFSET, 0x400);
 	if (hs == NULL)
 		return -1;
+	if (memcmp(hs->magic, "\x49\xe8\x95\xf9", 4) != 0)
+		return -1;
 
-	if (memcmp(hs->magic, "\x49\xe8\x95\xf9", 4) == 0) {
-		sprintf(id->type_version, "%u", hs->version);
+	hss = (struct hpfs_spare_super *) volume_id_get_buffer(id, off + HPFS_SUPERBLOCK_SPARE_OFFSET, 0x200);
+	if (hss == NULL)
+		return -1;
+	if (memcmp(hss->magic, "\x49\x18\x91\xf9", 4) != 0)
+		return -1;
 
-		volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
-		id->type = "hpfs";
-		return 0;
+	sprintf(id->type_version, "%u", hs->version);
+	volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
+	id->type = "hpfs";
+
+	/* if boot block looks valid, read label and uuid from there */
+	hbb = (struct hpfs_boot_block *) volume_id_get_buffer(id, off, 0x200);
+	if (hs == NULL)
+		return -1;
+	if (memcmp(hbb->magic, "\x55\xaa", 2) == 0 &&
+	    memcmp(hbb->sig_hpfs, "HPFS", 4) == 0 &&
+	    hbb->sig_28h == 0x28) {
+		volume_id_set_label_raw(id, hbb->vol_label, 11);
+		volume_id_set_label_string(id, hbb->vol_label, 11);
+		volume_id_set_uuid(id, hbb->vol_serno, 0, UUID_DOS);
 	}
 
-	return -1;
+	return 0;
 }
-- 
2.30.2