grub/grub-core/net/netbuff.c

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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>
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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_OUT_OF_RANGE, "put out of the packet range.");
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return GRUB_ERR_NONE;
}
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grub_err_t
grub_netbuff_unput (struct grub_net_buff *nb, grub_size_t len)
{
nb->tail -= len;
if (nb->tail < nb->head)
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return grub_error (GRUB_ERR_OUT_OF_RANGE,
"unput out of the packet range.");
return GRUB_ERR_NONE;
}
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grub_err_t
grub_netbuff_push (struct grub_net_buff *nb, grub_size_t len)
{
nb->data -= len;
if (nb->data < nb->head)
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return grub_error (GRUB_ERR_OUT_OF_RANGE,
"push out of the packet range.");
return GRUB_ERR_NONE;
}
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grub_err_t
grub_netbuff_pull (struct grub_net_buff *nb, grub_size_t len)
{
nb->data += len;
if (nb->data > nb->end)
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return grub_error (GRUB_ERR_OUT_OF_RANGE,
"pull out of the packet range.");
return GRUB_ERR_NONE;
}
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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))
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return grub_error (GRUB_ERR_OUT_OF_RANGE,
"reserve out of the packet range.");
return GRUB_ERR_NONE;
}
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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);
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if (len < NETBUFFMINLEN)
len = NETBUFFMINLEN;
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len = ALIGN_UP (len, NETBUFF_ALIGN);
data = grub_memalign (NETBUFF_ALIGN, len + sizeof (*nb));
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;
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nb->end = (char *) nb;
return nb;
}
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grub_err_t
grub_netbuff_free (struct grub_net_buff *nb)
{
grub_free (nb->head);
return GRUB_ERR_NONE;
}
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grub_err_t
grub_netbuff_clear (struct grub_net_buff *nb)
{
nb->data = nb->tail = nb->head;
return GRUB_ERR_NONE;
}