arch/all-pc/boot/grub2-aros/grub-core/net/netbuff.c

   1 /*
   2  *  GRUB  --  GRand Unified Bootloader
   3  *  Copyright (C) 2010 Free Software Foundation, Inc.
   4  *
   5  *  GRUB is free software: you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation, either version 3 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  GRUB is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <grub/err.h>
  20 #include <grub/misc.h>
  21 #include <grub/mm.h>
  22 #include <grub/net/netbuff.h>
  23
  24 grub_err_t
  25 grub_netbuff_put (struct grub_net_buff *nb, grub_size_t len)
  26 {
  27   nb->tail += len;
  28   if (nb->tail > nb->end)
  29     return grub_error (GRUB_ERR_BUG, "put out of the packet range.");
  30   return GRUB_ERR_NONE;
  31 }
  32
  33 grub_err_t
  34 grub_netbuff_unput (struct grub_net_buff *nb, grub_size_t len)
  35 {
  36   nb->tail -= len;
  37   if (nb->tail < nb->head)
  38     return grub_error (GRUB_ERR_BUG,
  39                        "unput out of the packet range.");
  40   return GRUB_ERR_NONE;
  41 }
  42
  43 grub_err_t
  44 grub_netbuff_push (struct grub_net_buff *nb, grub_size_t len)
  45 {
  46   nb->data -= len;
  47   if (nb->data < nb->head)
  48     return grub_error (GRUB_ERR_BUG,
  49                        "push out of the packet range.");
  50   return GRUB_ERR_NONE;
  51 }
  52
  53 grub_err_t
  54 grub_netbuff_pull (struct grub_net_buff *nb, grub_size_t len)
  55 {
  56   nb->data += len;
  57   if (nb->data > nb->end)
  58     return grub_error (GRUB_ERR_BUG,
  59                        "pull out of the packet range.");
  60   return GRUB_ERR_NONE;
  61 }
  62
  63 grub_err_t
  64 grub_netbuff_reserve (struct grub_net_buff *nb, grub_size_t len)
  65 {
  66   nb->data += len;
  67   nb->tail += len;
  68   if ((nb->tail > nb->end) || (nb->data > nb->end))
  69     return grub_error (GRUB_ERR_BUG,
  70                        "reserve out of the packet range.");
  71   return GRUB_ERR_NONE;
  72 }
  73
  74 struct grub_net_buff *
  75 grub_netbuff_alloc (grub_size_t len)
  76 {
  77   struct grub_net_buff *nb;
  78   void *data;
  79
  80   COMPILE_TIME_ASSERT (NETBUFF_ALIGN % sizeof (grub_properly_aligned_t) == 0);
  81
  82   if (len < NETBUFFMINLEN)
  83     len = NETBUFFMINLEN;
  84
  85   len = ALIGN_UP (len, NETBUFF_ALIGN);
  86 #ifdef GRUB_MACHINE_EMU
  87   data = grub_malloc (len + sizeof (*nb));
  88 #else
  89   data = grub_memalign (NETBUFF_ALIGN, len + sizeof (*nb));
  90 #endif
  91   if (!data)
  92     return NULL;
  93   nb = (struct grub_net_buff *) ((grub_properly_aligned_t *) data
  94                                  + len / sizeof (grub_properly_aligned_t));
  95   nb->head = nb->data = nb->tail = data;
  96   nb->end = (grub_uint8_t *) nb;
  97   return nb;
  98 }
  99
 100 void
 101 grub_netbuff_free (struct grub_net_buff *nb)
 102 {
 103   if (!nb)
 104     return;
 105   grub_free (nb->head);
 106 }
 107
 108 grub_err_t
 109 grub_netbuff_clear (struct grub_net_buff *nb)
 110 {
 111   nb->data = nb->tail = nb->head;
 112   return GRUB_ERR_NONE;
 113 }