[src/trunk]: src/sbin/gpt Fix three MBR extended partition related bugs:

[martin <martin%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/402bfafb6b15
branches:  trunk
changeset: 448251:402bfafb6b15
user:      martin <martin%NetBSD.org@localhost>
date:      Sun Jan 27 13:16:05 2019 +0000

description:
Fix three MBR extended partition related bugs:
 1) when walking an extended MBR chain, do not assign duplicate indices
 2) the pointer to the next MBR may be any of the MBR_PTYPE_EXT* variants
 3) the ext MBR chain links are relative to the primary extended partition,
    unlike the contained partitions which are relative to the extended MBR
    block address.

diffstat:

 sbin/gpt/gpt.c |  21 ++++++++++++---------
 1 files changed, 12 insertions(+), 9 deletions(-)

diffs (68 lines):

diff -r bdac16aaa833 -r 402bfafb6b15 sbin/gpt/gpt.c
--- a/sbin/gpt/gpt.c    Sun Jan 27 12:03:09 2019 +0000
+++ b/sbin/gpt/gpt.c    Sun Jan 27 13:16:05 2019 +0000
@@ -35,7 +35,7 @@
 __FBSDID("$FreeBSD: src/sbin/gpt/gpt.c,v 1.16 2006/07/07 02:44:23 marcel Exp $");
 #endif
 #ifdef __RCSID
-__RCSID("$NetBSD: gpt.c,v 1.76 2018/10/14 20:10:49 mlelstv Exp $");
+__RCSID("$NetBSD: gpt.c,v 1.77 2019/01/27 13:16:05 martin Exp $");
 #endif
 
 #include <sys/param.h>
@@ -279,7 +279,7 @@
 }
 
 static int
-gpt_mbr(gpt_t gpt, off_t lba)
+gpt_mbr(gpt_t gpt, off_t lba, unsigned int *next_index, off_t ext_offset)
 {
        struct mbr *mbr;
        map_t m, p;
@@ -345,20 +345,22 @@
                            (uintmax_t)lba);
                        continue;
                }
-               /* start is relative to the offset of the MBR itself. */
-               start += lba;
                if (gpt->verbose > 2)
                        gpt_msg(gpt, "MBR part: flag=%#x type=%d, start=%ju, "
                            "size=%ju", mbr->mbr_part[i].part_flag,
                            mbr->mbr_part[i].part_typ,
                            (uintmax_t)start, (uintmax_t)size);
-               if (mbr->mbr_part[i].part_typ != MBR_PTYPE_EXT_LBA) {
+               if (!MBR_IS_EXTENDED(mbr->mbr_part[i].part_typ)) {
+                       start += lba;
                        m = map_add(gpt, start, size, MAP_TYPE_MBR_PART, p, 0);
                        if (m == NULL)
                                return -1;
-                       m->map_index = i + 1;
+                       m->map_index = *next_index;
+                       (*next_index)++;
                } else {
-                       if (gpt_mbr(gpt, start) == -1)
+                       start += ext_offset;
+                       if (gpt_mbr(gpt, start, next_index,
+                           ext_offset ? ext_offset : start) == -1)
                                return -1;
                }
        }
@@ -479,7 +481,7 @@
        int mode, found;
        off_t devsz;
        gpt_t gpt;
-
+       unsigned int index;
 
        if ((gpt = calloc(1, sizeof(*gpt))) == NULL) {
                if (!(flags & GPT_QUIET))
@@ -567,7 +569,8 @@
        if (map_init(gpt, devsz) == -1)
                goto close;
 
-       if (gpt_mbr(gpt, 0LL) == -1)
+       index = 1;
+       if (gpt_mbr(gpt, 0LL, &index, 0U) == -1)
                goto close;
        if ((found = gpt_gpt(gpt, 1LL, 1)) == -1)
                goto close;