if_ether: add ether_arp definition

adapts to third-party code compilation. in the process of porting ConnMan,
we encounter some situations where the structure is not defined, or the
returned data types do not match the expectations. Refer to the common
implementation of other systems and add relevant definitions.

Signed-off-by: zhanghongyu <[email protected]>

Author: zhhyu7

include/netinet/if_ether.h

@@ -0,0 +1,64 @@
+/****************************************************************************
+ * include/netinet/if_ether.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you 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 _INCLUDE_NETINET_IF_ETHER_H
+#define _INCLUDE_NETINET_IF_ETHER_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <stdint.h>
+#include <net/if_arp.h>
+#include <net/ethernet.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define ETH_ALEN  6    /* Octets in one ethernet addr   */
+
+#define ETH_P_IP  ETHERTYPE_IP
+#define ETH_P_ARP ETHERTYPE_ARP
+
+/**
+ * Ethernet Address Resolution Protocol.
+ *
+ * See RFC 826 for protocol description.  Structure below is adapted
+ * to resolving internet addresses.  Field names used correspond to
+ * RFC 826.
+ */
+
+struct  ether_arp
+{
+  struct  arphdr ea_hdr;          /* fixed-size header */
+  uint8_t arp_sha[ETH_ALEN];      /* sender hardware address */
+  uint8_t arp_spa[4];             /* sender protocol address */
+  uint8_t arp_tha[ETH_ALEN];      /* target hardware address */
+  uint8_t arp_tpa[4];             /* target protocol address */
+};
+
+#define arp_hrd ea_hdr.ar_hrd
+#define arp_pro ea_hdr.ar_pro
+#define arp_hln ea_hdr.ar_hln
+#define arp_pln ea_hdr.ar_pln
+#define arp_op  ea_hdr.ar_op
+
+#endif /* _INCLUDE_NETINET_IF_ETHER_H */