GRUB2/MOD_SRC/grub-2.04/grub-core/lib/cmdline.c

   1 /* cmdline.c - linux command line handling */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2010  Free Software Foundation, Inc.
   5  *
   6  *  GRUB is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <grub/lib/cmdline.h>
  21 #include <grub/misc.h>
  22
  23 static unsigned int check_arg (char *c, int *has_space)
  24 {
  25   int space = 0;
  26   unsigned int size = 0;
  27
  28   while (*c)
  29     {
  30       if (*c == '\\' || *c == '\'' || *c == '"')
  31         size++;
  32       else if (*c == ' ')
  33         space = 1;
  34
  35       size++;
  36       c++;
  37     }
  38
  39   if (space)
  40     size += 2;
  41
  42   if (has_space)
  43     *has_space = space;
  44
  45   return size;
  46 }
  47
  48 unsigned int grub_loader_cmdline_size (int argc, char *argv[])
  49 {
  50   int i;
  51   unsigned int size = 0;
  52
  53   for (i = 0; i < argc; i++)
  54     {
  55       size += check_arg (argv[i], 0);
  56       size++; /* Separator space or NULL.  */
  57     }
  58
  59   if (size == 0)
  60     size = 1;
  61
  62   return size;
  63 }
  64
  65 grub_err_t
  66 grub_create_loader_cmdline (int argc, char *argv[], char *buf,
  67                             grub_size_t size, enum grub_verify_string_type type)
  68 {
  69   int i, space;
  70   unsigned int arg_size;
  71   char *c, *orig_buf = buf;
  72
  73   for (i = 0; i < argc; i++)
  74     {
  75       c = argv[i];
  76       arg_size = check_arg(argv[i], &space);
  77       arg_size++; /* Separator space or NULL.  */
  78
  79       if (size < arg_size)
  80         break;
  81
  82       size -= arg_size;
  83
  84       if (space)
  85         *buf++ = '"';
  86
  87       while (*c)
  88         {
  89           if (*c == '\\' && *(c+1) == 'x' &&
  90                    grub_isxdigit(*(c+2)) && grub_isxdigit(*(c+3)))
  91             {
  92               *buf++ = *c++;
  93               *buf++ = *c++;
  94               *buf++ = *c++;
  95               *buf++ = *c++;
  96               continue;
  97             }
  98           else if (*c == '\\' || *c == '\'' || *c == '"')
  99             *buf++ = '\\';
 100
 101           *buf++ = *c;
 102           c++;
 103         }
 104
 105       if (space)
 106         *buf++ = '"';
 107
 108       *buf++ = ' ';
 109     }
 110
 111   /* Replace last space with null.  */
 112   if (i)
 113     buf--;
 114
 115   *buf = 0;
 116
 117   return grub_verify_string (orig_buf, type);
 118 }