Add mbr_get_fstype() and use it to translate MBR dp_typ fields

into FS_* values. Similar to what gpt_get_fstype() does. Code is
clearer and better positioned for planned enhancements to
spoofing.

No intentional functional change.

diff --git a/sys/kern/subr_disk.c b/sys/kern/subr_disk.c
index 2e4fb92..b208bc6 100644 (file)
--- a/sys/kern/subr_disk.c
+++ b/sys/kern/subr_disk.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: subr_disk.c,v 1.267 2022/11/09 10:26:37 krw Exp $     */
+/*     $OpenBSD: subr_disk.c,v 1.268 2022/11/10 16:12:05 krw Exp $     */
 /*     $NetBSD: subr_disk.c,v 1.17 1996/03/16 23:17:08 christos Exp $  */
 
 /*
@@ -114,6 +114,7 @@ int gpt_get_hdr(struct buf *, void (*)(struct buf *), struct disklabel *,
 int gpt_get_parts(struct buf *, void (*)(struct buf *),
     struct disklabel *, const struct gpt_header *, struct gpt_partition **);
 int gpt_get_fstype(const struct uuid *);
+int mbr_get_fstype(const uint8_t);
 
 int duid_equal(u_char *, u_char *);
 
@@ -703,6 +704,34 @@ spoofgpt(struct buf *bp, void (*strat)(struct buf *), const uint8_t *dosbb,
        return 0;
 }
 
+int
+mbr_get_fstype(const uint8_t dp_typ)
+{
+       switch (dp_typ) {
+       case DOSPTYP_OPENBSD:
+               return FS_BSDFFS;
+       case DOSPTYP_UNUSED:
+               return FS_UNUSED;
+       case DOSPTYP_LINUX:
+               return FS_EXT2FS;
+       case DOSPTYP_NTFS:
+               return FS_NTFS;
+       case DOSPTYP_EFISYS:
+       case DOSPTYP_FAT12:
+       case DOSPTYP_FAT16S:
+       case DOSPTYP_FAT16B:
+       case DOSPTYP_FAT16L:
+       case DOSPTYP_FAT32:
+       case DOSPTYP_FAT32L:
+               return FS_MSDOS;
+       case DOSPTYP_EFI:
+       case DOSPTYP_EXTEND:
+       case DOSPTYP_EXTENDL:
+       default:
+               return FS_OTHER;
+       }
+}
+
 void
 spoofmbr(struct buf *bp, void (*strat)(struct buf *), const uint8_t *dosbb,
     struct disklabel *lp, daddr_t *partoffp)
@@ -791,30 +820,11 @@ spoofmbr(struct buf *bp, void (*strat)(struct buf *), const uint8_t *dosbb,
                                }
                                wander = 1;
                                continue;
-
-                       case DOSPTYP_UNUSED:
-                               fstype = FS_UNUSED;
-                               break;
-                       case DOSPTYP_LINUX:
-                               fstype = FS_EXT2FS;
-                               break;
-                       case DOSPTYP_NTFS:
-                               fstype = FS_NTFS;
-                               break;
-                       case DOSPTYP_EFISYS:
-                       case DOSPTYP_FAT12:
-                       case DOSPTYP_FAT16S:
-                       case DOSPTYP_FAT16B:
-                       case DOSPTYP_FAT16L:
-                       case DOSPTYP_FAT32:
-                       case DOSPTYP_FAT32L:
-                               fstype = FS_MSDOS;
-                               break;
                        default:
-                               fstype = FS_OTHER;
                                break;
                        }
 
+                       fstype = mbr_get_fstype(dp[i].dp_typ);
                        if (n < MAXPARTITIONS) {
                                pp = &lp->d_partitions[n++];
                                pp->p_fstype = fstype;