From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: Chris Coulson <chris.coulson@canonical.com>

Date: Tue, 5 Jan 2021 22:17:28 +0000

Subject: [PATCH] kern/parser: Introduce process_char() helper

grub_parser_split_cmdline() iterates over each command line character.

In order to add error checking and to simplify the subsequent error

handling, split the character processing in to a separate function.

Signed-off-by: Chris Coulson <chris.coulson@canonical.com>

Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

---

 grub-core/kern/parser.c | 74 ++++++++++++++++++++++++++++++-------------------

 1 file changed, 46 insertions(+), 28 deletions(-)

diff --git a/grub-core/kern/parser.c b/grub-core/kern/parser.c

index 23ebebf5ffa..db6e255834f 100644

--- a/grub-core/kern/parser.c

+++ b/grub-core/kern/parser.c

@@ -1,7 +1,7 @@

 /* parser.c - the part of the parser that can return partial tokens */

 /*

  *  GRUB  --  GRand Unified Bootloader

- *  Copyright (C) 2005,2007,2009  Free Software Foundation, Inc.

+ *  Copyright (C) 2005,2007,2009,2021  Free Software Foundation, Inc.

  *

  *  GRUB is free software: you can redistribute it and/or modify

  *  it under the terms of the GNU General Public License as published by

@@ -129,6 +129,46 @@ add_var (char *varname, char **bp, char **vp,

     *((*bp)++) = *val;

 }

+static grub_err_t

+process_char (char c, char *buffer, char **bp, char *varname, char **vp,

+	      grub_parser_state_t state, int *argc,

+	      grub_parser_state_t *newstate)

+{

+  char use;

+

+  *newstate = grub_parser_cmdline_state (state, c, &use;;

+

+  /*

+   * If a variable was being processed and this character does

+   * not describe the variable anymore, write the variable to

+   * the buffer.

+   */

+  add_var (varname, bp, vp, state, *newstate);

+

+  if (check_varstate (*newstate))

+    {

+      if (use)

+	*((*vp)++) = use;

+    }

+  else if (*newstate == GRUB_PARSER_STATE_TEXT &&

+	   state != GRUB_PARSER_STATE_ESC && grub_isspace (use))

+    {

+      /*

+       * Don't add more than one argument if multiple

+       * spaces are used.

+       */

+      if (*bp != buffer && *((*bp) - 1) != '\0')

+	{

+	  *((*bp)++) = '\0';

+	  (*argc)++;

+	}

+    }

+  else if (use)

+    *((*bp)++) = use;

+

+  return GRUB_ERR_NONE;

+}

+

 grub_err_t

 grub_parser_split_cmdline (const char *cmdline,

 			   grub_reader_getline_t getline, void *getline_data,

@@ -172,35 +212,13 @@ grub_parser_split_cmdline (const char *cmdline,

       for (; *rp != '\0'; rp++)

 	{

 	  grub_parser_state_t newstate;

-	  char use;

-	  newstate = grub_parser_cmdline_state (state, *rp, &use;;

-

-	  /* If a variable was being processed and this character does

-	     not describe the variable anymore, write the variable to

-	     the buffer.  */

-	  add_var (varname, &bp, &vp, state, newstate);

-

-	  if (check_varstate (newstate))

-	    {

-	      if (use)

-		*(vp++) = use;

-	    }

-	  else

+	  if (process_char (*rp, buffer, &bp, varname, &vp, state, argc,

+			    &newstate) != GRUB_ERR_NONE)

 	    {

-	      if (newstate == GRUB_PARSER_STATE_TEXT

-		  && state != GRUB_PARSER_STATE_ESC && grub_isspace (use))

-		{

-		  /* Don't add more than one argument if multiple

-		     spaces are used.  */

-		  if (bp != buffer && *(bp - 1))

-		    {

-		      *(bp++) = '\0';

-		      (*argc)++;

-		    }

-		}

-	      else if (use)

-		*(bp++) = use;

+	      if (rd != cmdline)

+		grub_free (rd);

+	      return grub_errno;

 	    }

 	  state = newstate;

 	}