From 86be8711fe701a280e0589ad14ccaf8ed286688f Mon Sep 17 00:00:00 2001
From: Michael Chang <[email protected]>
Date: Fri, 18 Feb 2022 21:51:16 +0800
Subject: [PATCH 122/272] export environment at start up

If the prep_loadenv module is built into the core image, it will read
the environment block automatically during start up and export all
variables. The will ease integration with those without early scripts to
running the command.

Signed-off-by: Michael Chang <[email protected]>
---
 grub-core/Makefile.core.def       |  2 +
 grub-core/commands/prep_loadenv.c | 77 +++++++++++++++++++++++++++++++
 grub-core/kern/env.c              |  2 +
 grub-core/kern/main.c             |  3 ++
 include/grub/env.h                |  1 +
 5 files changed, 85 insertions(+)

diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 38d93ff4f..38f5deeee 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -2678,4 +2678,6 @@ module = {
   name = prep_loadenv;
   common = commands/prep_loadenv.c;
   enable = powerpc_ieee1275;
+  cflags = '$(CFLAGS_POSIX) $(CFLAGS_GNULIB)';
+  cppflags = '$(CPPFLAGS_POSIX) $(CPPFLAGS_GNULIB)';
 };
diff --git a/grub-core/commands/prep_loadenv.c b/grub-core/commands/prep_loadenv.c
index e731684d3..eaef2c9d4 100644
--- a/grub-core/commands/prep_loadenv.c
+++ b/grub-core/commands/prep_loadenv.c
@@ -10,6 +10,7 @@
 #include <grub/extcmd.h>
 #include <grub/i18n.h>
 #include <grub/gpt_partition.h>
+#include <regex.h>
 
 GRUB_MOD_LICENSE ("GPLv3+");
 
@@ -191,6 +192,65 @@ prep_partname (const char *devname, char **prep)
   return err;
 }
 
+static grub_err_t
+boot_disk_prep_partname (char **name)
+{
+  regex_t regex;
+  int ret;
+  grub_size_t s;
+  char *comperr;
+  const char *cmdpath;
+  regmatch_t *matches = NULL;
+  grub_err_t err = GRUB_ERR_NONE;
+
+  *name = NULL;
+
+  cmdpath = grub_env_get ("cmdpath");
+  if (!cmdpath)
+    return GRUB_ERR_NONE;
+
+  ret = regcomp (&regex, "\\(([^,]+)(,?.*)?\\)(.*)", REG_EXTENDED);
+  if (ret)
+    goto fail;
+
+  matches = grub_calloc (regex.re_nsub + 1, sizeof (*matches));
+  if (! matches)
+    goto fail;
+
+  ret = regexec (&regex, cmdpath, regex.re_nsub + 1, matches, 0);
+  if (!ret)
+    {
+      char *devname = devname = match_substr (matches + 1, cmdpath);
+      if (!devname)
+	{
+	  err = grub_error (GRUB_ERR_FILE_NOT_FOUND, "%s contains no disk name", cmdpath);
+	  goto out;
+	}
+
+      err = prep_partname (devname, name);
+ out:
+      grub_free (devname);
+      regfree (&regex);
+      grub_free (matches);
+      return err;
+    }
+
+ fail:
+  grub_free (matches);
+  s = regerror (ret, &regex, 0, 0);
+  comperr = grub_malloc (s);
+  if (!comperr)
+    {
+      regfree (&regex);
+      return grub_errno;
+    }
+  regerror (ret, &regex, comperr, s);
+  err = grub_error (GRUB_ERR_TEST_FAILURE, "%s", comperr);
+  regfree (&regex);
+  grub_free (comperr);
+  return err;
+}
+
 static grub_err_t
 grub_cmd_prep_loadenv (grub_command_t cmd __attribute__ ((unused)),
 		       int argc,
@@ -221,10 +281,27 @@ grub_cmd_prep_loadenv (grub_command_t cmd __attribute__ ((unused)),
   return GRUB_ERR_NONE;
 }
 
+static void
+early_prep_loadenv (void)
+{
+  grub_err_t err;
+  char *prep;
+
+  err = boot_disk_prep_partname (&prep);
+  if (err == GRUB_ERR_NONE && prep)
+    err = prep_read_envblk (prep);
+  if (err == GRUB_ERR_BAD_FILE_TYPE || err == GRUB_ERR_FILE_NOT_FOUND)
+    grub_error_pop ();
+  if (err != GRUB_ERR_NONE)
+    grub_print_error ();
+  grub_free (prep);
+}
+
 static grub_command_t cmd_prep_load;
 
 GRUB_MOD_INIT(prep_loadenv)
 {
+  early_env_hook = early_prep_loadenv;
   cmd_prep_load =
     grub_register_command("prep_load_env", grub_cmd_prep_loadenv,
 			  "DEVICE",
diff --git a/grub-core/kern/env.c b/grub-core/kern/env.c
index 764068896..5aa2dee6c 100644
--- a/grub-core/kern/env.c
+++ b/grub-core/kern/env.c
@@ -28,6 +28,8 @@ static struct grub_env_context initial_context;
 /* The current context.  */
 struct grub_env_context *grub_current_context = &initial_context;
 
+void (*early_env_hook) (void) = NULL;
+
 /* Return the hash representation of the string S.  */
 static unsigned int
 grub_env_hashval (const char *s)
diff --git a/grub-core/kern/main.c b/grub-core/kern/main.c
index 731c07c29..02df49206 100644
--- a/grub-core/kern/main.c
+++ b/grub-core/kern/main.c
@@ -309,6 +309,9 @@ grub_main (void)
 
   grub_boot_time ("Before execution of embedded config.");
 
+  if (early_env_hook != NULL)
+    early_env_hook ();
+
   if (load_config)
     grub_parser_execute (load_config);
 
diff --git a/include/grub/env.h b/include/grub/env.h
index 6b9379a30..cf78c5e12 100644
--- a/include/grub/env.h
+++ b/include/grub/env.h
@@ -69,5 +69,6 @@ grub_env_extractor_open (int source);
 grub_err_t
 grub_env_extractor_close (int source);
 
+extern void (*EXPORT_VAR (early_env_hook)) (void);
 
 #endif /* ! GRUB_ENV_HEADER */
-- 
2.41.0