arp_format.c: Move the logic that formats an ARP packet into a separate file...

arp_format.c: Move the logic that formats an ARP packet into a separate file where it can be re-used.

net/arp/Make.defs

@@ -36,7 +36,7 @@
 # ARP supported is not provided for SLIP (Ethernet only)
 
 ifneq ($(CONFIG_NET_SLIP),y)
-NET_CSRCS +=arp_arpin.c arp_out.c arp_table.c arp_timer.c
+NET_CSRCS +=arp_arpin.c arp_out.c arp_format.c arp_table.c arp_timer.c
 
 ifeq ($(CONFIG_NET_ARP_IPIN),y)
 NET_CSRCS += arp_ipin.c

net/arp/arp.h

@@ -53,6 +53,7 @@
 #include <nuttx/config.h>
 
 #include <stdint.h>
+#include <netinet/in.h>
 
 /****************************************************************************
  * Pre-processor Definitions
@@ -156,6 +157,24 @@ void arp_timer_initialize(void);
 
 void arp_timer(void);
 
+/****************************************************************************
+ * Name: arp_format
+ *
+ * Description:
+ *   Format an ARP packet.
+ *
+ * Input Parameters:
+ *   dev    - Device structure
+ *   ipaddr - Target IP address (32-bit)
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+struct net_driver_s; /* Forward reference */
+void arp_format(FAR struct net_driver_s *dev, in_addr_t ipaddr);
+
 /****************************************************************************
  * Name: arp_dump
  *

net/arp/arp_format.c

+/****************************************************************************
+ * net/arp/arp_format.c
+ *
+ *   Copyright (C) 2007-2011, 2014 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Based on uIP which also has a BSD style license:
+ *
+ *   Author: Adam Dunkels <adam@dunkels.com>
+ *   Copyright (c) 2001-2003, Adam Dunkels.
+ *   All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+ * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <string.h>
+#include <debug.h>
+
+#include <netinet/in.h>
+
+#include <nuttx/net/netdev.h>
+#include <nuttx/net/arp.h>
+
+#include "arp/arp.h"
+
+#ifdef CONFIG_NET_ARP
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define ETHBUF  ((struct eth_hdr_s *)&dev->d_buf[0])
+#define ARPBUF  ((struct arp_hdr_s *)&dev->d_buf[NET_LL_HDRLEN])
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: arp_format
+ *
+ * Description:
+ *   Format an ARP packet.
+ *
+ * Input Parameters:
+ *   dev    - Device structure
+ *   ipaddr - Target IP address (32-bit)
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void arp_format(FAR struct net_driver_s *dev, in_addr_t ipaddr)
+{
+  FAR struct arp_hdr_s *arp = ARPBUF;
+  FAR struct eth_hdr_s *eth = ETHBUF;
+
+  /* Construct the ARP packet.  Creating both the Ethernet and ARP headers */
+
+  memset(eth->dest, 0xff, ETHER_ADDR_LEN);
+  memset(arp->ah_dhwaddr, 0x00, ETHER_ADDR_LEN);
+  memcpy(eth->src, dev->d_mac.ether_addr_octet, ETHER_ADDR_LEN);
+  memcpy(arp->ah_shwaddr, dev->d_mac.ether_addr_octet, ETHER_ADDR_LEN);
+
+  net_ipaddr_hdrcopy(arp->ah_dipaddr, &ipaddr);
+  net_ipaddr_hdrcopy(arp->ah_sipaddr, &dev->d_ipaddr);
+
+  arp->ah_opcode   = HTONS(ARP_REQUEST);
+  arp->ah_hwtype   = HTONS(ARP_HWTYPE_ETH);
+  arp->ah_protocol = HTONS(ETHTYPE_IP);
+  arp->ah_hwlen    = ETHER_ADDR_LEN;
+  arp->ah_protolen = 4;
+
+  eth->type        = HTONS(ETHTYPE_ARP);
+  dev->d_len       = sizeof(struct arp_hdr_s) + NET_LL_HDRLEN;
+}
+
+#endif /* CONFIG_NET_ARP */

net/arp/arp_out.c

@@ -133,7 +133,6 @@ static const uint8_t g_multicast_ethaddr[3] = {0x01, 0x00, 0x5e};
 void arp_out(FAR struct net_driver_s *dev)
 {
   FAR const struct arp_entry *tabptr = NULL;
-  FAR struct arp_hdr_s       *parp   = ARPBUF;
   FAR struct eth_hdr_s       *peth   = ETHBUF;
   FAR struct arp_iphdr_s     *pip    = IPBUF;
   in_addr_t                   ipaddr;
@@ -225,29 +224,14 @@ void arp_out(FAR struct net_driver_s *dev)
       tabptr = arp_find(ipaddr);
       if (!tabptr)
         {
-           nllvdbg("ARP request for IP %04lx\n", (long)ipaddr);
+           nllvdbg("ARP request for IP %08lx\n", (unsigned long)ipaddr);
 
           /* The destination address was not in our ARP table, so we
            * overwrite the IP packet with an ARP request.
            */
 
-          memset(peth->dest, 0xff, ETHER_ADDR_LEN);
-          memset(parp->ah_dhwaddr, 0x00, ETHER_ADDR_LEN);
-          memcpy(peth->src, dev->d_mac.ether_addr_octet, ETHER_ADDR_LEN);
-          memcpy(parp->ah_shwaddr, dev->d_mac.ether_addr_octet, ETHER_ADDR_LEN);
-
-          net_ipaddr_hdrcopy(parp->ah_dipaddr, &ipaddr);
-          net_ipaddr_hdrcopy(parp->ah_sipaddr, &dev->d_ipaddr);
-
-          parp->ah_opcode   = HTONS(ARP_REQUEST);
-          parp->ah_hwtype   = HTONS(ARP_HWTYPE_ETH);
-          parp->ah_protocol = HTONS(ETHTYPE_IP);
-          parp->ah_hwlen    = ETHER_ADDR_LEN;
-          parp->ah_protolen = 4;
-          arp_dump(parp);
-
-          peth->type        = HTONS(ETHTYPE_ARP);
-          dev->d_len        = sizeof(struct arp_hdr_s) + NET_LL_HDRLEN;
+          arp_format(dev, ipaddr);
+          arp_dump(ARPBUF);
           return;
         }