nshlib/nsh_netcmds.c: Add a -t option to the arp command which will enable printing the entire ARP table.

include/netutils/netlib.h

@@ -314,7 +314,8 @@ int netlib_set_arpmapping(FAR const struct sockaddr_in *inaddr,
                           FAR const uint8_t *macaddr);
 #ifdef CONFIG_NETLINK_ROUTE
 struct arp_enty_s;
-int netlib_get_arptable(FAR struct arp_enty_s *arptab, unsigned int nentries);
+ssize_t netlib_get_arptable(FAR struct arp_entry_s *arptab,
+                            unsigned int nentries);
 #endif
 #endif
 

netutils/netlib/netlib_getarptab.c

@@ -90,11 +90,12 @@ struct netlib_recvfrom_response_s
  *              size sizeof(struct arp_entry_s)
  *
  * Return:
- *   0 on success; a negated errno value on failure.
+ *   The number of ARP table entries read is returnd on success; a negated
+ *   errno value is returned on failure.
  *
  ****************************************************************************/
 
-int netlib_get_arptable(FAR struct arp_enty_s *arptab, unsigned int nentries)
+ssize_t netlib_get_arptable(FAR struct arp_entry_s *arptab, unsigned int nentries)
 {
   FAR struct netlib_recvfrom_response_s *resp;
   struct netlib_sendto_request_s req;
@@ -104,7 +105,7 @@ int netlib_get_arptable(FAR struct arp_enty_s *arptab, unsigned int nentries)
   ssize_t paysize;
   ssize_t maxsize;
   int fd;
-  int ret = EXIT_FAILURE;
+  int ret;
 
   /* Allocate a buffer to hold the response */
 
@@ -114,6 +115,7 @@ int netlib_get_arptable(FAR struct arp_enty_s *arptab, unsigned int nentries)
   if (resp == NULL)
     {
       fprintf(stderr, "ERROR: Faile to allocat response buffer\n");
+      ret = -ENOMEM;
       return EXIT_FAILURE;
     }
 
@@ -124,6 +126,7 @@ int netlib_get_arptable(FAR struct arp_enty_s *arptab, unsigned int nentries)
     {
       int errcode = errno;
       fprintf(stderr, "ERROR: socket() failed: %d\n", errcode);
+      ret = -errcode;
       goto errout_with_resp;
     }
 
@@ -140,6 +143,7 @@ int netlib_get_arptable(FAR struct arp_enty_s *arptab, unsigned int nentries)
     {
       int errcode = errno;
       fprintf(stderr, "ERROR: send() failed: %d\n", errcode);
+      ret = -errcode;
       goto errout_with_socket;
     }
 
@@ -148,6 +152,7 @@ int netlib_get_arptable(FAR struct arp_enty_s *arptab, unsigned int nentries)
     {
       int errcode = errno;
       fprintf(stderr, "ERROR: recv() failed: %d\n", errcode);
+      ret = -errcode;
       goto errout_with_socket;
     }
 
@@ -157,6 +162,7 @@ int netlib_get_arptable(FAR struct arp_enty_s *arptab, unsigned int nentries)
       resp->hdr.nlmsg_len > nrecvd)
     {
       fprintf(stderr, "ERROR: Bad message\n");
+      ret = -EIO;
       goto errout_with_socket;
     }
 
@@ -169,7 +175,7 @@ int netlib_get_arptable(FAR struct arp_enty_s *arptab, unsigned int nentries)
     }
 
   memcpy(arptab, resp->data, paysize);
-  ret = EXIT_SUCCESS;
+  ret = paysize / sizeof(struct arp_entry_s);
 
 errout_with_socket:
   close(fd);

nshlib/README.txt

@@ -318,7 +318,7 @@ o addroute <target> [<netmask>] <router>
   The second form of the addroute command can be used to set the default
   gateway.
 
-o arp [-a <ipaddr>|-d <ipaddr>|-s <ipaddr> <hwaddr>]
+o arp [-t|-a <ipaddr>|-d <ipaddr>|-s <ipaddr> <hwaddr>]
 
   Access the OS ARP table.
 
@@ -332,6 +332,10 @@ o arp [-a <ipaddr>|-d <ipaddr>|-s <ipaddr> <hwaddr>]
      Will set (or replace) the mapping of the IP address <ipaddr> to the
      hardware address <hwaddr>.
 
+  -t
+     Will dump the entire content of the ARP table.  This option is only
+     available if CONFIG_NETLINK_ROUTE is enabled.
+
   Example:
 
     nsh> arp -a 10.0.0.1

nshlib/nsh_command.c

@@ -113,8 +113,12 @@ static const struct cmdmap_s g_cmdmap[] =
 #endif
 
 #if defined(CONFIG_NET) && defined(CONFIG_NET_ARP) && !defined(CONFIG_NSH_DISABLE_ARP)
+#ifdef CONFIG_NETLINK_ROUTE
+  { "arp",      cmd_arp,      2, 4, "[-t|-a <ipaddr>|-d <ipaddr>|-s <ipaddr> <hwaddr>]" },
+#else
   { "arp",      cmd_arp,      3, 4, "[-a <ipaddr>|-d <ipaddr>|-s <ipaddr> <hwaddr>]" },
 #endif
+#endif
 
 #if defined(CONFIG_NETUTILS_CODECS) && defined(CONFIG_CODECS_BASE64)
 #  ifndef CONFIG_NSH_DISABLE_BASE64DEC

nshlib/nsh_netcmds.c

@@ -47,6 +47,7 @@
 #include <stdint.h>
 #include <stdbool.h>
 #include <stdio.h>
+#include <inttypes.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
@@ -85,6 +86,10 @@
 #  endif
 #endif
 
+#ifdef CONFIG_NETLINK_ROUTE
+#    include <nuttx/net/arp.h>
+#endif
+
 #ifdef CONFIG_NETUTILS_NETLIB
 #  include "netutils/netlib.h"
 #endif
@@ -1049,11 +1054,90 @@ int cmd_arp(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv)
 
   /* Forms:
    *
-   * aap -a <ipaddr>
+   * arp -t
+   * arp -a <ipaddr>
    * arp -d <ipdaddr>
    * arp -s <ipaddr> <hwaddr>
    */
 
+#ifdef CONFIG_NETLINK_ROUTE
+  if (strcmp(argv[1], "-t") == 0)
+    {
+      FAR struct arp_entry_s *arptab;
+      size_t arpsize;
+      ssize_t nentries;
+      char ipaddr[16];
+      char ethaddr[24];
+      int i;
+
+      if (argc != 2)
+        {
+          goto errout_toomany;
+        }
+
+      /* Allocate a buffer to hold the ARP table */
+
+      arpsize = CONFIG_NET_ARPTAB_SIZE * sizeof(struct arp_entry_s);
+      arptab  = (FAR struct arp_entry_s *)malloc(arpsize);
+      if (arptab == NULL)
+        {
+          nsh_error(vtbl, g_fmtcmdoutofmemory, argv[0]);
+          return ERROR;
+        }
+
+      /* Read the ARP table */
+
+      nentries = netlib_get_arptable(arptab, CONFIG_NET_ARPTAB_SIZE);
+      if (nentries < 0)
+        {
+          nsh_error(vtbl, g_fmtcmdfailed, argv[0], netlib_get_arptable, 
+                    NSH_ERRNO_OF(-nentries));
+          free(arptab);
+          return ERROR;
+        }
+
+      /* Dump the ARP table
+       *
+       * xx.xx.xx.xx xx:xx:xx:xx:xx:xx xxxxxxxx[xxxxxxxx]
+       */
+
+      nsh_output(vtbl, "%-12s %-17s Last Access Time\n",
+                 "IP Address", "Ethernet Address");
+
+      for (i = 0; i < nentries; i++)
+        {
+          FAR uint8_t *ptr;
+
+          /* Convert the IPv4 address to a string */
+
+          ptr = (FAR uint8_t *)&arptab[i].at_ipaddr;
+          snprintf(ipaddr, 16, "%u.%u.%u.%u",
+                   ptr[0], ptr[1], ptr[2], ptr[3]);
+
+          /* Convert the MAC address string to a binary */
+
+          snprintf(ethaddr, 24, "%02x:%02x:%02x:%02x:%02x:%02x",
+                   arptab[i].at_ethaddr.ether_addr_octet[0],
+                   arptab[i].at_ethaddr.ether_addr_octet[1],
+                   arptab[i].at_ethaddr.ether_addr_octet[2],
+                   arptab[i].at_ethaddr.ether_addr_octet[3],
+                   arptab[i].at_ethaddr.ether_addr_octet[4],
+                   arptab[i].at_ethaddr.ether_addr_octet[5]);
+
+#ifdef CONFIG_SYSTEM_TIME64
+          nsh_output(vtbl, "%12s %17s 0x%" PRIx64 "\n",
+                     ipaddr, ethaddr, (uint64_t)arptab[i].at_time);
+#else
+          nsh_output(vtbl, "%12s %17s 0x%" PRIx32 "\n",
+                     ipaddr, ethaddr, (uint32_t)arptab[i].at_time);
+#endif
+        }
+
+      free(arptab);
+      ret = OK;
+    }
+  else
+#endif
   if (strcmp(argv[1], "-a") == 0)
     {
       if (argc != 3)