xsh_arp.c

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/* xsh_arp.c - xsh_arp */

#include <xinu.h>
#include <stdio.h>
#include <string.h>

static  void    arp_dmp();
/*------------------------------------------------------------------------
 * xsh_arp - display the current ARP cache for an interface
 *------------------------------------------------------------------------
 */
shellcmd xsh_arp(int nargs, char *args[])
{
    /* For argument '--help', emit help about the 'arp' command */

    if (nargs == 2 && strncmp(args[1], "--help", 7) == 0) {
        printf("Use: %s\n\n", args[0]);
        printf("Description:\n");
        printf("\tDisplays information from the ARP cache\n");
        printf("Options:\n");
        printf("\t--help\t display this help and exit\n");
        return 0;
    }

    /* Dump the Entire ARP cache */
    printf("\n");
    arp_dmp();

    return 0;
}


/*------------------------------------------------------------------------
 * arp_dmp - dump the ARP cache
 *------------------------------------------------------------------------
 */
static  void arp_dmp ()
{
    int32   i, j;           /* index into the ARP table */
    struct  arpentry *arptr;    /* pointer to entry in cache    */

    /* Print entries from the ARP table */

    printf("ARP cache:\n");
    printf("   State Pid    IP Address    Hardware Address\n");
    printf("   ----- --- --------------- -----------------\n");
    for (i = 0; i < ARP_SIZ; i++) {
        arptr = &arpcache[i];
        if (arptr->arstate == AR_FREE) {
            continue;
        }
        switch(arptr->arstate) {
            case AR_PENDING:    printf("   PEND "); break;
            case AR_RESOLVED:   printf("   RESLV"); break;
            default:        printf("   ?????"); break;
        }
        if (arptr->arstate == AR_PENDING) {
            printf("%4d ", arptr->arpid);
        } else {
            printf("     ");
        }
        printf("%3d.", (arptr->arpaddr & 0xFF000000) >> 24);
        printf("%3d.", (arptr->arpaddr & 0x00FF0000) >> 16);
        printf("%3d.", (arptr->arpaddr & 0x0000FF00) >> 8);
        printf("%3d",  (arptr->arpaddr & 0x000000FF));

        printf(" %02X", arptr->arhaddr[0]);
        for (j = 1; j < ARP_HALEN; j++) {
            printf(":%02X", arptr->arhaddr[j]);
        }
        printf("\n");
    }
    printf("\n");
    return;
}