lib: pttype: add BSD subpartitions support

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/lib/pttype.c b/lib/pttype.c
index 429b47551cacc403dbe40cff3ea760e115c92a10..23070b9ad36bfbd936fa78671ae7959bb77dfd03 100644 (file)
--- a/lib/pttype.c
+++ b/lib/pttype.c
@@ -13,6 +13,9 @@
 
 #include "blkdev.h"
 
+/* we need to read two sectors, beacuse BSD label offset is 512 */
+#define PTTYPE_BUFSIZ  (2 * DEFAULT_SECTOR_SIZE)       /* 1024 */
+
 /*
  * SGI
  */
@@ -212,16 +215,35 @@ mac_parttable(char *base)
                ntohs(maclabel(base)->magic) == MAC_OLD_PARTITION_MAGIC);
 }
 
+/*
+ * BSD subpartitions listed in a disklabel, under a dos-like partition.
+ */
+#define BSD_DISKMAGIC          0x82564557UL            /* The disk magic number */
+#define BSD_DISKMAGIC_SWAPED   0x57455682UL
+struct bsd_disklabel {
+       uint32_t        magic;          /* the magic number */
+       /* ... */
+};
+
+static int
+bsd_parttable(char *base)
+{
+       struct bsd_disklabel *l = (struct bsd_disklabel *)
+                                       (base + (DEFAULT_SECTOR_SIZE * 1));
+
+       return (l->magic == BSD_DISKMAGIC || l->magic == BSD_DISKMAGIC_SWAPED);
+}
+
 const char *
 get_pt_type(const char *device)
 {
        int     fd;
        char    *type = NULL;
-       char    buf[DEFAULT_SECTOR_SIZE];
+       char    buf[PTTYPE_BUFSIZ];
 
        if ((fd = open(device, O_RDONLY)) < 0)
                ;
-       else if (read(fd, buf, DEFAULT_SECTOR_SIZE) != DEFAULT_SECTOR_SIZE)
+       else if (read(fd, buf, PTTYPE_BUFSIZ) != PTTYPE_BUFSIZ)
                ;
        else {
                if (sgi_parttable(buf))
@@ -234,6 +256,8 @@ get_pt_type(const char *device)
                        type = "DOS";
                else if (mac_parttable(buf))
                        type = "Mac";
+               else if (bsd_parttable(buf))
+                       type = "BSD";
        }
 
        if (fd >= 0)