partx: add mac partition table support

Signed-off-by: Davidlohr Bueso <dave@gnu.org>

1 files changed, 74 insertions, 0 deletions

diff --git a/partx/mac.c b/partx/mac.c
new file mode 100644
index 00000000..ed4ed9b9
--- /dev/null
+++ b/partx/mac.c
@@ -0,0 +1,74 @@
+/*
+ * Lifted from kpartx's mac.c
+ *
+ * Integrated to partx (utils-linux-ng)
+ *       Davidlohr Bueso <dave@gnu.org>
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+
+#include "bitops.h"
+#include "partx.h"
+
+#define MAC_PARTITION_MAGIC     0x504d
+#define MAC_DRIVER_MAGIC        0x4552
+
+struct mac_partition {
+        uint16_t  signature;      /* expected to be MAC_PARTITION_MAGIC */
+        uint16_t  res1;
+        uint32_t  map_count;      /* # blocks in partition map */
+        uint32_t  start_block;    /* absolute starting block # of partition */
+        uint32_t  block_count;    /* number of blocks in partition */
+        /* there is more stuff after this that we don't need */
+};
+
+/* Driver descriptor structure, in block 0 */
+struct mac_driver_desc {
+        uint16_t  signature;      /* expected to be MAC_DRIVER_MAGIC */
+        uint16_t  block_size;
+        uint32_t  block_count;
+};
+
+int
+read_mac_pt(int fd, struct slice all, struct slice *sp, int ns) {
+	struct mac_driver_desc *md;
+        struct mac_partition *part;
+	unsigned secsize;
+	char *data;
+	int blk, blocks_in_map;
+        int n = 0;
+
+	md = (struct mac_driver_desc *) getblock(fd, 0);
+	if (md == NULL)
+		return -1;
+
+	if (be16_to_cpu(md->signature) != MAC_DRIVER_MAGIC)
+		return -1;
+
+	secsize = be16_to_cpu(md->block_size);
+	data = getblock(fd, secsize/512);
+	if (!data)
+		return -1;
+	part = (struct mac_partition *) (data + secsize%512);
+
+	if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC)
+		return -1;
+
+	blocks_in_map = be32_to_cpu(part->map_count);
+	for (blk = 1; blk <= blocks_in_map && blk <= ns; ++blk, ++n) {
+		int pos = blk * secsize;
+		data = getblock(fd, pos/512);
+		if (!data)
+			return -1;
+
+		part = (struct mac_partition *) (data + pos%512);
+		if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC)
+			break;
+
+		sp[n].start = be32_to_cpu(part->start_block) * (secsize/512);
+		sp[n].size = be32_to_cpu(part->block_count) * (secsize/512);
+	}
+	return n;
+}