Add vinum volume/raid support (#41)

.gitattributes

@@ -2,3 +2,4 @@ tests/data/dm/* filter=lfs diff=lfs merge=lfs -text
 tests/data/md/* filter=lfs diff=lfs merge=lfs -text
 tests/data/ddf/* filter=lfs diff=lfs merge=lfs -text
 tests/data/lvm/* filter=lfs diff=lfs merge=lfs -text
+tests/data/vinum/* filter=lfs diff=lfs merge=lfs -text

dissect/volume/vinum/c_vinum.py

@@ -0,0 +1,83 @@
+from dissect.cstruct import cstruct
+
+# Structures are copied from:
+# https://github.com/freebsd/freebsd-src/blob/f21a6a6a8fc59393173d9a537ed8cebbdbd6343c/sys/geom/vinum/geom_vinum_var.h
+
+vinum_def = """
+struct timeval {
+    uint64 sec;
+    uint64 usec;
+};
+
+typedef uint64 off_t;
+
+/*
+ * Slice header
+ *
+ * Vinum drives start with this structure:
+ *
+ *\                                            Sector
+ * |--------------------------------------|
+ * |   PDP-11 memorial boot block         |      0
+ * |--------------------------------------|
+ * |   Disk label, maybe                  |      1
+ * |--------------------------------------|
+ * |   Slice definition  (vinum_hdr)      |      8
+ * |--------------------------------------|
+ * |                                      |
+ * |   Configuration info, first copy     |      9
+ * |                                      |
+ * |--------------------------------------|
+ * |                                      |
+ * |   Configuration info, second copy    |      9 + size of config
+ * |                                      |
+ * |--------------------------------------|
+ */
+
+/* Sizes and offsets of our information. */
+#define GV_HDR_OFFSET       4096    /* Offset of vinum header. */
+#define GV_HDR_LEN          512     /* Size of vinum header. */
+#define GV_CFG_OFFSET       4608    /* Offset of first config copy. */
+#define GV_CFG_LEN          65536   /* Size of config copy. */
+
+/* This is where the actual data starts. */
+#define GV_DATA_START       (GV_CFG_LEN * 2 + GV_CFG_OFFSET)
+/* #define GV_DATA_START       (GV_CFG_LEN * 2 + GV_HDR_LEN) */
+
+#define GV_MAXDRIVENAME     32      /* Maximum length of a device name. */
+
+/*
+ * hostname is 256 bytes long, but we don't need to shlep multiple copies in
+ * vinum.  We use the host name just to identify this system, and 32 bytes
+ * should be ample for that purpose.
+ */
+
+#define GV_HOSTNAME_LEN     32
+struct gv_label {
+    char            sysname[GV_HOSTNAME_LEN];   /* System name at creation time. */
+    char            name[GV_MAXDRIVENAME];      /* Our name of the drive. */
+    struct timeval  date_of_birth;              /* The time it was created ... */
+    struct timeval  last_update;                /* ... and the time of last update. */
+    off_t           drive_size;                 /* Total size incl. headers. */
+};
+
+#define GV_OLD_MAGIC        0x494E2056494E4F00LL
+#define GV_OLD_NOMAGIC      0x4E4F2056494E4F00LL
+#define GV_MAGIC            0x56494E554D2D3100LL
+#define GV_NOMAGIC          0x56494E554D2D2D00LL
+
+/* The 'header' of each valid vinum drive. */
+struct gv_hdr {
+    uint64_t        magic;
+    uint64_t        config_length;
+    struct gv_label label;
+} header;
+"""  # noqa W605
+
+c_vinum = cstruct(endian=">").load(vinum_def)
+
+# Not really needed as this size is hardcoded in the various GV_*_OFFSET and related values
+SECTOR_SIZE = 512
+
+MAGIC_ACTIVE = {c_vinum.GV_OLD_MAGIC, c_vinum.GV_MAGIC}
+MAGIC_INACTIVE = {c_vinum.GV_OLD_NOMAGIC, c_vinum.GV_NOMAGIC}