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/*
* ethernet/arp.c: IP v4 ARP node
*
* Copyright (c) 2010 Cisco and/or its affiliates.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __ARP_PACKET_H__
#define __ARP_PACKET_H__
#include <vnet/arp/arp.h>
/* Either we drop the packet or we send a reply to the sender. */
typedef enum
{
ARP_REPLY_NEXT_DROP,
ARP_REPLY_NEXT_REPLY_TX,
ARP_REPLY_N_NEXT,
} arp_reply_next_t;
static_always_inline u32
arp_mk_reply (vnet_main_t * vnm,
vlib_buffer_t * p0,
u32 sw_if_index0,
const ip4_address_t * if_addr0,
ethernet_arp_header_t * arp0, ethernet_header_t * eth_rx)
{
vnet_hw_interface_t *hw_if0;
u8 *rewrite0, rewrite0_len;
ethernet_header_t *eth_tx;
u32 next0;
/* Send a reply.
An adjacency to the sender is not always present,
so we use the interface to build us a rewrite string
which will contain all the necessary tags. */
rewrite0 = ethernet_build_rewrite (vnm, sw_if_index0,
VNET_LINK_ARP, eth_rx->src_address);
rewrite0_len = vec_len (rewrite0);
/* Figure out how much to rewind current data from adjacency. */
vlib_buffer_advance (p0, -rewrite0_len);
eth_tx = vlib_buffer_get_current (p0);
vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;
hw_if0 = vnet_get_sup_hw_interface (vnm, sw_if_index0);
/* Send reply back through input interface */
vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;
next0 = ARP_REPLY_NEXT_REPLY_TX;
arp0->opcode = clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply);
arp0->ip4_over_ethernet[1] = arp0->ip4_over_ethernet[0];
mac_address_from_bytes (&arp0->ip4_over_ethernet[0].mac,
hw_if0->hw_address);
clib_mem_unaligned (&arp0->ip4_over_ethernet[0].ip4.data_u32, u32) =
if_addr0->data_u32;
/* Hardware must be ethernet-like. */
ASSERT (vec_len (hw_if0->hw_address) == 6);
/* the rx nd tx ethernet headers wil overlap in the case
* when we received a tagged VLAN=0 packet, but we are sending
* back untagged */
clib_memcpy_fast (eth_tx, rewrite0, vec_len (rewrite0));
vec_free (rewrite0);
return (next0);
}
#endif
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/
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