[PATCH v3 2/2] cryptodisk: Add support for LUKS2 in (proc)/luks_script

[Glenn Washburn]

The sector size in bytes is added to each line and it is allowed to be 6
decimal digits long, which covers the most common cases of 512 and 4096
byte sectors with space for two additional digits as future-proofing. The
size allocation is updated to reflect this additional field. Also make
clearer the size allocation calculation.

Signed-off-by: Glenn Washburn <development@efficientek.com>
---
 grub-core/disk/cryptodisk.c | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/grub-core/disk/cryptodisk.c b/grub-core/disk/cryptodisk.c
index c62656a0faea..066cec566aec 100644
--- a/grub-core/disk/cryptodisk.c
+++ b/grub-core/disk/cryptodisk.c
@@ -1478,12 +1478,22 @@ luks_script_get (grub_size_t *sz)
   *sz = 0;
 
   for (i = cryptodisk_list; i != NULL; i = i->next)
-    if (grub_strcmp (i->modname, "luks") == 0)
+    if (grub_strcmp (i->modname, "luks") == 0 ||
+       grub_strcmp (i->modname, "luks2") == 0)
       {
-       size += sizeof ("luks_mount ");
+       size += grub_strlen (i->modname);
+       size += sizeof ("_mount");
        size += grub_strlen (i->uuid);
        size += grub_strlen (i->cipher->cipher->name);
-       size += 54;
+       /*
+        * Add space in the line for (in order) spaces, cipher mode, cipher IV
+        * mode, sector offset, sector size and the trailing newline. This is
+        * an upper bound on the size of this data. There are 15 extra bytes
+        * in an earlier version of this code that are unaccounted for. It is
+        * left in the calculations in case it is needed. At worst, its short-
+        * lived wasted space.
+        */
+       size += 5 + 5 + 8 + 20 + 6 + 1 + 15;
        if (i->essiv_hash)
          size += grub_strlen (i->essiv_hash->name);
        size += i->keysize * 2;
@@ -1496,15 +1506,19 @@ luks_script_get (grub_size_t *sz)
   ptr = ret;
 
   for (i = cryptodisk_list; i != NULL; i = i->next)
-    if (grub_strcmp (i->modname, "luks") == 0)
+    if (grub_strcmp (i->modname, "luks") == 0 ||
+       grub_strcmp (i->modname, "luks2") == 0)
       {
        unsigned j;
        const char *iptr;
-       ptr = grub_stpcpy (ptr, "luks_mount ");
+       ptr = grub_stpcpy (ptr, i->modname);
+       ptr = grub_stpcpy (ptr, "_mount ");
        ptr = grub_stpcpy (ptr, i->uuid);
        *ptr++ = ' ';
        ptr += grub_snprintf (ptr, 21, "%" PRIxGRUB_OFFSET, i->offset_sectors);
        *ptr++ = ' ';
+       ptr += grub_snprintf (ptr, 7, "%u", 1 << i->log_sector_size);
+       *ptr++ = ' ';
        for (iptr = i->cipher->cipher->name; *iptr; iptr++)
          *ptr++ = grub_tolower (*iptr);
        switch (i->mode)
-- 
2.34.1