diff options
Diffstat (limited to 'sys/kern/subr_disk.c')
| -rw-r--r-- | sys/kern/subr_disk.c | 60 |
1 files changed, 59 insertions, 1 deletions
diff --git a/sys/kern/subr_disk.c b/sys/kern/subr_disk.c index bca3caf3faf..8c2ed620f85 100644 --- a/sys/kern/subr_disk.c +++ b/sys/kern/subr_disk.c @@ -1,4 +1,4 @@ -/* $OpenBSD: subr_disk.c,v 1.202 2015/09/10 14:11:53 krw Exp $ */ +/* $OpenBSD: subr_disk.c,v 1.203 2015/09/10 14:28:17 krw Exp $ */ /* $NetBSD: subr_disk.c,v 1.17 1996/03/16 23:17:08 christos Exp $ */ /* @@ -56,6 +56,7 @@ #include <sys/dkio.h> #include <sys/vnode.h> #include <sys/task.h> +#include <sys/stdint.h> #include <sys/socket.h> #include <sys/socketvar.h> @@ -105,6 +106,9 @@ void disk_attach_callback(void *); int readdisksector(struct buf *, void (*)(struct buf *), struct disklabel *, u_int64_t); +#ifdef GPT +int gpt_chk_mbr(struct dos_partition *, struct disklabel *); +#endif /* * Compute checksum for disk label. @@ -366,6 +370,23 @@ readdoslabel(struct buf *bp, void (*strat)(struct buf *), (bp->b_data[511] & 0xff); if (mbrtest != 0x55aa) goto notmbr; +#ifdef GPT + if (gpt_chk_mbr(dp, lp) == 0) { + error = readgptlabel(bp, strat, lp, + partoffp ? &dospartoff : NULL, spoofonly); + if (error == 0) { + if (partoffp) + *partoffp = dospartoff; + return (0); + } else { + /* Restore all potentially tweakee's */ + dospartoff = 0; + DL_SETBSTART(lp, 0); + DL_SETBEND(lp, DL_GETDSIZE(lp)); + goto notmbr; + } + } +#endif } if (ourpart == -1) { @@ -556,6 +577,43 @@ int gpt_chk_hdr(struct gpt_header *); int gpt_chk_parts(struct gpt_header *, struct gpt_partition *); int get_fstype(struct uuid *); +/* + * Returns 0 if the MBR with the provided partition array is a GPT protective + * MBR, and returns 1 otherwise. A GPT protective MBR would have one and only + * one MBR partition, an EFI partition that either covers the whole disk or as + * much of it as is possible with a 32bit size field. + * + * NOTE: MS always uses a size of UINT32_MAX for the EFI partition!** + */ +int +gpt_chk_mbr(struct dos_partition *dp, struct disklabel *lp) +{ + struct dos_partition *dp2; + u_int64_t dsize; + int efi, found, i; + u_int32_t psize; + + found = efi = 0; + for (dp2=dp, i=0; i < NDOSPART; i++, dp2++) { + if (dp2->dp_typ == DOSPTYP_UNUSED) + continue; + found++; + if (dp2->dp_typ != DOSPTYP_EFI) + continue; + dsize = DL_GETDSIZE(lp); + psize = letoh32(dp2->dp_size); + if (psize == (dsize - 1) || + psize == UINT32_MAX) { + if (letoh32(dp2->dp_start) == 1) + efi++; + } + } + if (found == 1 && efi == 1) + return (0); + + return (EINVAL); +} + int gpt_chk_hdr(struct gpt_header *gh) { |