/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2010,2011 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/net.h>
#include <grub/net/ip.h>
#include <grub/net/netbuff.h>
struct icmp_header
{
grub_uint8_t type;
grub_uint8_t code;
grub_uint16_t checksum;
} __attribute__ ((packed));
struct ping_header
{
grub_uint16_t id;
grub_uint16_t seq;
} __attribute__ ((packed));
enum
{
ICMP_ECHO_REPLY = 0,
ICMP_ECHO = 8,
};
grub_err_t
grub_net_recv_icmp_packet (struct grub_net_buff *nb,
struct grub_net_network_level_interface *inf,
const grub_net_link_level_address_t *ll_src,
const grub_net_network_level_address_t *src)
{
struct icmp_header *icmph;
grub_err_t err;
grub_uint16_t checksum;
/* Ignore broadcast. */
if (!inf)
{
grub_netbuff_free (nb);
return GRUB_ERR_NONE;
}
icmph = (struct icmp_header *) nb->data;
if (nb->tail - nb->data < (grub_ssize_t) sizeof (*icmph))
{
grub_netbuff_free (nb);
return GRUB_ERR_NONE;
}
checksum = icmph->checksum;
icmph->checksum = 0;
if (checksum != grub_net_ip_chksum (nb->data, nb->tail - nb->data))
{
icmph->checksum = checksum;
return GRUB_ERR_NONE;
}
icmph->checksum = checksum;
err = grub_netbuff_pull (nb, sizeof (*icmph));
if (err)
return err;
switch (icmph->type)
{
case ICMP_ECHO:
{
struct grub_net_buff *nb_reply;
struct icmp_header *icmphr;
if (icmph->code)
break;
nb_reply = grub_netbuff_alloc (nb->tail - nb->data + 512);
if (!nb_reply)
{
grub_netbuff_free (nb);
return grub_errno;
}
err = grub_netbuff_reserve (nb_reply, nb->tail - nb->data + 512);
if (err)
goto ping_fail;
err = grub_netbuff_push (nb_reply, nb->tail - nb->data);
if (err)
goto ping_fail;
grub_memcpy (nb_reply->data, nb->data, nb->tail - nb->data);
err = grub_netbuff_push (nb_reply, sizeof (*icmphr));
if (err)
goto ping_fail;
icmphr = (struct icmp_header *) nb_reply->data;
icmphr->type = ICMP_ECHO_REPLY;
icmphr->code = 0;
icmphr->checksum = 0;
icmphr->checksum = grub_net_ip_chksum ((void *) nb_reply->data,
nb_reply->tail - nb_reply->data);
err = grub_net_send_ip_packet (inf, src, ll_src,
nb_reply, GRUB_NET_IP_ICMP);
ping_fail:
grub_netbuff_free (nb);
grub_netbuff_free (nb_reply);
return err;
}
};
grub_netbuff_free (nb);
return GRUB_ERR_NONE;
}