grub-core/script/argv.c

   1 /* argv.c - methods for constructing argument vector */
   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/mm.h>
  21 #include <grub/misc.h>
  22 #include <grub/script_sh.h>
  23 #include <grub/safemath.h>
  24
  25 /* Return nearest power of two that is >= v.  */
  26 static unsigned
  27 round_up_exp (unsigned v)
  28 {
  29   COMPILE_TIME_ASSERT (sizeof (v) == 4);
  30
  31   v--;
  32   v |= v >> 1;
  33   v |= v >> 2;
  34   v |= v >> 4;
  35   v |= v >> 8;
  36   v |= v >> 16;
  37
  38   v++;
  39   v += (v == 0);
  40
  41   return v;
  42 }
  43
  44 void
  45 grub_script_argv_free (struct grub_script_argv *argv)
  46 {
  47   unsigned i;
  48
  49   if (argv->args)
  50     {
  51       for (i = 0; i < argv->argc; i++)
  52         grub_free (argv->args[i]);
  53
  54       grub_free (argv->args);
  55     }
  56
  57   argv->argc = 0;
  58   argv->args = 0;
  59   argv->script = 0;
  60 }
  61
  62 /* Make argv from argc, args pair.  */
  63 int
  64 grub_script_argv_make (struct grub_script_argv *argv, int argc, char **args)
  65 {
  66   int i;
  67   struct grub_script_argv r = { 0, 0, 0 };
  68
  69   for (i = 0; i < argc; i++)
  70     if (grub_script_argv_next (&r)
  71         || grub_script_argv_append (&r, args[i], grub_strlen (args[i])))
  72       {
  73         grub_script_argv_free (&r);
  74         return 1;
  75       }
  76   *argv = r;
  77   return 0;
  78 }
  79
  80 /* Prepare for next argc.  */
  81 int
  82 grub_script_argv_next (struct grub_script_argv *argv)
  83 {
  84   char **p = argv->args;
  85   grub_size_t sz;
  86
  87   if (argv->args && argv->argc && argv->args[argv->argc - 1] == 0)
  88     return 0;
  89
  90   if (grub_add (argv->argc, 2, &sz) ||
  91       grub_mul (sz, sizeof (char *), &sz))
  92     return 1;
  93
  94   p = grub_realloc (p, round_up_exp (sz));
  95   if (! p)
  96     return 1;
  97
  98   argv->argc++;
  99   argv->args = p;
 100
 101   if (argv->argc == 1)
 102     argv->args[0] = 0;
 103   argv->args[argv->argc] = 0;
 104   return 0;
 105 }
 106
 107 /* Append `s' to the last argument.  */
 108 int
 109 grub_script_argv_append (struct grub_script_argv *argv, const char *s,
 110                          grub_size_t slen)
 111 {
 112   grub_size_t a;
 113   char *p = argv->args[argv->argc - 1];
 114   grub_size_t sz;
 115
 116   if (! s)
 117     return 0;
 118
 119   a = p ? grub_strlen (p) : 0;
 120
 121   if (grub_add (a, slen, &sz) ||
 122       grub_add (sz, 1, &sz) ||
 123       grub_mul (sz, sizeof (char), &sz))
 124     return 1;
 125
 126   p = grub_realloc (p, round_up_exp (sz));
 127   if (! p)
 128     return 1;
 129
 130   grub_memcpy (p + a, s, slen);
 131   p[a+slen] = 0;
 132   argv->args[argv->argc - 1] = p;
 133
 134   return 0;
 135 }
 136
 137 /* Split `s' and append words as multiple arguments.  */
 138 int
 139 grub_script_argv_split_append (struct grub_script_argv *argv, const char *s)
 140 {
 141   const char *p;
 142   int errors = 0;
 143
 144   if (! s)
 145     return 0;
 146
 147   while (*s && grub_isspace (*s))
 148     s++;
 149
 150   while (! errors && *s)
 151     {
 152       p = s;
 153       while (*s && ! grub_isspace (*s))
 154         s++;
 155
 156       errors += grub_script_argv_append (argv, p, s - p);
 157
 158       while (*s && grub_isspace (*s))
 159         s++;
 160
 161       if (*s)
 162         errors += grub_script_argv_next (argv);
 163     }
 164   return errors;
 165 }