From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Renaud=20M=C3=A9trich?= <rmetrich@redhat.com>

Date: Tue, 8 Feb 2022 08:39:11 +0100

Subject: [PATCH] search: new --efidisk-only option on EFI systems

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When using 'search' on EFI systems, we sometimes want to exclude devices

that are not EFI disks (e.g. md, lvm).

This is typically used when wanting to chainload when having a software

raid (md) for EFI partition:

with no option, 'search --file /EFI/redhat/shimx64.efi' sets root envvar

to 'md/boot_efi' which cannot be used for chainloading since there is no

effective EFI device behind.

This commit also refactors handling of --no-floppy option.

Signed-off-by: Renaud Métrich <rmetrich@redhat.com>

[rharwood: apply rmetrich's flags initialization fix]

Signed-off-by: Robbie Harwood <rharwood@redhat.com>

---

 grub-core/commands/search.c      | 27 +++++++++++++++++++++++----

 grub-core/commands/search_wrap.c | 18 ++++++++++++------

 include/grub/search.h            | 15 ++++++++++++---

 3 files changed, 47 insertions(+), 13 deletions(-)

diff --git a/grub-core/commands/search.c b/grub-core/commands/search.c

index 51656e361c..57d26ced8a 100644

--- a/grub-core/commands/search.c

+++ b/grub-core/commands/search.c

@@ -47,7 +47,7 @@ struct search_ctx

 {

   const char *key;

   const char *var;

-  int no_floppy;

+  enum search_flags flags;

   char **hints;

   unsigned nhints;

   int count;

@@ -62,10 +62,29 @@ iterate_device (const char *name, void *data)

   int found = 0;

   /* Skip floppy drives when requested.  */

-  if (ctx->no_floppy &&

+  if (ctx->flags & SEARCH_FLAGS_NO_FLOPPY &&

       name[0] == 'f' && name[1] == 'd' && name[2] >= '0' && name[2] <= '9')

     return 0;

+  /* Limit to EFI disks when requested.  */

+  if (ctx->flags & SEARCH_FLAGS_EFIDISK_ONLY)

+    {

+      grub_device_t dev;

+      dev = grub_device_open (name);

+      if (! dev)

+	{

+	  grub_errno = GRUB_ERR_NONE;

+	  return 0;

+	}

+      if (! dev->disk || dev->disk->dev->id != GRUB_DISK_DEVICE_EFIDISK_ID)

+	{

+	  grub_device_close (dev);

+	  grub_errno = GRUB_ERR_NONE;

+	  return 0;

+	}

+      grub_device_close (dev);

+    }

+

 #ifdef DO_SEARCH_FS_UUID

 #define compare_fn grub_strcasecmp

 #else

@@ -261,13 +280,13 @@ try (struct search_ctx *ctx)

 }

 void

-FUNC_NAME (const char *key, const char *var, int no_floppy,

+FUNC_NAME (const char *key, const char *var, enum search_flags flags,

 	   char **hints, unsigned nhints)

 {

   struct search_ctx ctx = {

     .key = key,

     .var = var,

-    .no_floppy = no_floppy,

+    .flags = flags,

     .hints = hints,

     .nhints = nhints,

     .count = 0,

diff --git a/grub-core/commands/search_wrap.c b/grub-core/commands/search_wrap.c

index 47fc8eb996..0b62acf853 100644

--- a/grub-core/commands/search_wrap.c

+++ b/grub-core/commands/search_wrap.c

@@ -40,6 +40,7 @@ static const struct grub_arg_option options[] =

      N_("Set a variable to the first device found."), N_("VARNAME"),

      ARG_TYPE_STRING},

     {"no-floppy",	'n', 0, N_("Do not probe any floppy drive."), 0, 0},

+    {"efidisk-only",	0, 0, N_("Only probe EFI disks."), 0, 0},

     {"hint",	        'h', GRUB_ARG_OPTION_REPEATABLE,

      N_("First try the device HINT. If HINT ends in comma, "

 	"also try subpartitions"), N_("HINT"), ARG_TYPE_STRING},

@@ -73,6 +74,7 @@ enum options

     SEARCH_FS_UUID,

     SEARCH_SET,

     SEARCH_NO_FLOPPY,

+    SEARCH_EFIDISK_ONLY,

     SEARCH_HINT,

     SEARCH_HINT_IEEE1275,

     SEARCH_HINT_BIOS,

@@ -89,6 +91,7 @@ grub_cmd_search (grub_extcmd_context_t ctxt, int argc, char **args)

   const char *id = 0;

   int i = 0, j = 0, nhints = 0;

   char **hints = NULL;

+  enum search_flags flags = 0;

   if (state[SEARCH_HINT].set)

     for (i = 0; state[SEARCH_HINT].args[i]; i++)

@@ -180,15 +183,18 @@ grub_cmd_search (grub_extcmd_context_t ctxt, int argc, char **args)

       goto out;

     }

+  if (state[SEARCH_NO_FLOPPY].set)

+    flags |= SEARCH_FLAGS_NO_FLOPPY;

+

+  if (state[SEARCH_EFIDISK_ONLY].set)

+    flags |= SEARCH_FLAGS_EFIDISK_ONLY;

+

   if (state[SEARCH_LABEL].set)

-    grub_search_label (id, var, state[SEARCH_NO_FLOPPY].set, 

-		       hints, nhints);

+    grub_search_label (id, var, flags, hints, nhints);

   else if (state[SEARCH_FS_UUID].set)

-    grub_search_fs_uuid (id, var, state[SEARCH_NO_FLOPPY].set,

-			 hints, nhints);

+    grub_search_fs_uuid (id, var, flags, hints, nhints);

   else if (state[SEARCH_FILE].set)

-    grub_search_fs_file (id, var, state[SEARCH_NO_FLOPPY].set, 

-			 hints, nhints);

+    grub_search_fs_file (id, var, flags, hints, nhints);

   else

     grub_error (GRUB_ERR_INVALID_COMMAND, "unspecified search type");

diff --git a/include/grub/search.h b/include/grub/search.h

index d80347df34..4190aeb2cb 100644

--- a/include/grub/search.h

+++ b/include/grub/search.h

@@ -19,11 +19,20 @@

 #ifndef GRUB_SEARCH_HEADER

 #define GRUB_SEARCH_HEADER 1

-void grub_search_fs_file (const char *key, const char *var, int no_floppy,

+enum search_flags

+  {

+    SEARCH_FLAGS_NO_FLOPPY	= 1,

+    SEARCH_FLAGS_EFIDISK_ONLY	= 2

+  };

+

+void grub_search_fs_file (const char *key, const char *var,

+			  enum search_flags flags,

 			  char **hints, unsigned nhints);

-void grub_search_fs_uuid (const char *key, const char *var, int no_floppy,

+void grub_search_fs_uuid (const char *key, const char *var,

+			  enum search_flags flags,

 			  char **hints, unsigned nhints);

-void grub_search_label (const char *key, const char *var, int no_floppy,

+void grub_search_label (const char *key, const char *var,

+			enum search_flags flags,

 			char **hints, unsigned nhints);

 #endif