grub/grub-core/lib/cmdline.c

/* cmdline.c - linux command line handling */
/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 2010  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
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  GRUB is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <grub/lib/cmdline.h>
#include <grub/misc.h>
#include <grub/tpm.h>

static unsigned int check_arg (char *c, int *has_space)
{
  int space = 0;
  unsigned int size = 0;

  while (*c)
    {
      if (*c == '\\' || *c == '\'' || *c == '"')
	size++;
      else if (*c == ' ')
	space = 1;

      size++;
      c++;
    }

  if (space)
    size += 2;

  if (has_space)
    *has_space = space;

  return size;
}

unsigned int grub_loader_cmdline_size (int argc, char *argv[])
{
  int i;
  unsigned int size = 0;

  for (i = 0; i < argc; i++)
    {
      size += check_arg (argv[i], 0);
      size++; /* Separator space or NULL.  */
    }

  if (size == 0)
    size = 1;

  return size;
}

int grub_create_loader_cmdline (int argc, char *argv[], char *buf,
				grub_size_t size)
{
  int i, space;
  unsigned int arg_size;
  char *c, *orig = buf;

  for (i = 0; i < argc; i++)
    {
      c = argv[i];
      arg_size = check_arg(argv[i], &space);
      arg_size++; /* Separator space or NULL.  */

      if (size < arg_size)
	break;

      size -= arg_size;

      if (space)
	*buf++ = '"';

      while (*c)
	{
	  if (*c == '\\' || *c == '\'' || *c == '"')
	    *buf++ = '\\';

	  *buf++ = *c;
	  c++;
	}

      if (space)
	*buf++ = '"';

      *buf++ = ' ';
    }

  /* Replace last space with null.  */
  if (i)
    buf--;

  *buf = 0;

  grub_tpm_measure ((void *)orig, grub_strlen (orig), GRUB_CMDLINE_PCR,
		    "Kernel Commandline");

  return i;
}