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/*
* 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/err.h>
#include <grub/misc.h>
#include <grub/mm.h>
#include <grub/net/netbuff.h>
grub_err_t
grub_netbuff_put (struct grub_net_buff *nb, grub_size_t len)
{
nb->tail += len;
if (nb->tail > nb->end)
return grub_error (GRUB_ERR_BUG, "put out of the packet range.");
return GRUB_ERR_NONE;
}
grub_err_t
grub_netbuff_unput (struct grub_net_buff *nb, grub_size_t len)
{
nb->tail -= len;
if (nb->tail < nb->head)
return grub_error (GRUB_ERR_BUG,
"unput out of the packet range.");
return GRUB_ERR_NONE;
}
grub_err_t
grub_netbuff_push (struct grub_net_buff *nb, grub_size_t len)
{
nb->data -= len;
if (nb->data < nb->head)
return grub_error (GRUB_ERR_BUG,
"push out of the packet range.");
return GRUB_ERR_NONE;
}
grub_err_t
grub_netbuff_pull (struct grub_net_buff *nb, grub_size_t len)
{
nb->data += len;
if (nb->data > nb->end || nb->data > nb->tail)
return grub_error (GRUB_ERR_BUG,
"pull out of the packet range.");
return GRUB_ERR_NONE;
}
grub_err_t
grub_netbuff_reserve (struct grub_net_buff *nb, grub_size_t len)
{
nb->data += len;
nb->tail += len;
if ((nb->tail > nb->end) || (nb->data > nb->end))
return grub_error (GRUB_ERR_BUG,
"reserve out of the packet range.");
return GRUB_ERR_NONE;
}
struct grub_net_buff *
grub_netbuff_alloc (grub_size_t len)
{
struct grub_net_buff *nb;
void *data;
COMPILE_TIME_ASSERT (NETBUFF_ALIGN % sizeof (grub_properly_aligned_t) == 0);
/*
* The largest size of a TCP packet is 64 KiB, and everything else
* should be a lot smaller - most MTUs are 1500 or less. Cap data
* size at 64 KiB + a buffer.
*/
if (len > 0xffffUL + 0x1000UL)
{
grub_error (GRUB_ERR_BUG,
"attempted to allocate a packet that is too big");
return NULL;
}
if (len < NETBUFFMINLEN)
len = NETBUFFMINLEN;
len = ALIGN_UP (len, NETBUFF_ALIGN);
#ifdef GRUB_MACHINE_EMU
data = grub_malloc (len + sizeof (*nb));
#else
data = grub_memalign (NETBUFF_ALIGN, len + sizeof (*nb));
#endif
if (!data)
return NULL;
nb = (struct grub_net_buff *) ((grub_properly_aligned_t *) data
+ len / sizeof (grub_properly_aligned_t));
nb->head = nb->data = nb->tail = data;
nb->end = (grub_uint8_t *) nb;
return nb;
}
struct grub_net_buff *
grub_netbuff_make_pkt (grub_size_t len)
{
struct grub_net_buff *nb;
grub_err_t err;
nb = grub_netbuff_alloc (len + 512);
if (!nb)
return NULL;
err = grub_netbuff_reserve (nb, len + 512);
if (err)
goto fail;
err = grub_netbuff_push (nb, len);
if (err)
goto fail;
return nb;
fail:
grub_netbuff_free (nb);
return NULL;
}
void
grub_netbuff_free (struct grub_net_buff *nb)
{
if (!nb)
return;
grub_free (nb->head);
}
grub_err_t
grub_netbuff_clear (struct grub_net_buff *nb)
{
nb->data = nb->tail = nb->head;
return GRUB_ERR_NONE;
}
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