arp.c

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/*
 * arp.c
 *
 * Copyright (c) 2001 Dug Song <dugsong@monkey.org>
 *
 * $Id: arp.c,v 1.10 2002/05/08 04:55:32 dugsong Exp $
 */

#include "config.h"

#include <sys/types.h>

#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "dnet.h"
#include "aton.h"
#include "mod.h"

void
arp_usage(void)
{
        fprintf(stderr, "Usage: dnet arp [op|sha|spa|tha|tpa <value>] ...\n"
                        "       dnet arp show\n"
                        "       dnet arp get <host>\n"
                        "       dnet arp add <host> <mac>\n"
                        "       dnet arp delete <host>\n");
        exit(1);
}

static int
print_arp(const struct arp_entry *entry, void *arg)
{
        printf("%s at %s\n", addr_ntoa(&entry->arp_pa),
            addr_ntoa(&entry->arp_ha));
        return (0);
}

static int
arp_kern_main(int argc, char *argv[])
{
        struct arp_entry entry;
        arp_t *arp;
        char *cmd;

        if (argc < 2)
                arp_usage();
        
        cmd = argv[1];

        if ((arp = arp_open()) == NULL)
                err(1, "arp_open");
        
        if (strcmp(cmd, "show") == 0) {
                if (arp_loop(arp, print_arp, NULL) < 0)
                        err(1, "arp_loop");
        } else if (strcmp(cmd, "get") == 0) {
                if (addr_pton(argv[2], &entry.arp_pa) < 0)
                        err(1, "addr_pton");
                if (arp_get(arp, &entry) < 0)
                        err(1, "arp_get");
                print_arp(&entry, NULL);
        } else if (strcmp(cmd, "add") == 0) {
                if (addr_pton(argv[2], &entry.arp_pa) < 0 ||
                    addr_pton(argv[3], &entry.arp_ha) < 0)
                        err(1, "addr_pton");
                if (arp_add(arp, &entry) < 0)
                        err(1, "arp_add");
                printf("%s added\n", addr_ntoa(&entry.arp_pa));
        } else if (strcmp(cmd, "delete") == 0) {
                if (addr_pton(argv[2], &entry.arp_pa) < 0)
                        err(1, "addr_pton");
                if (arp_delete(arp, &entry) < 0)
                        err(1, "arp_delete");
                printf("%s deleted\n", addr_ntoa(&entry.arp_pa));
        } else
                arp_usage();
        
        arp_close(arp);

        return (0);
}

int
arp_main(int argc, char *argv[])
{
        struct arp_hdr *arp;
        struct arp_ethip *ethip;
        struct addr addr;
        u_char *p, buf[ETH_MTU];        /* XXX */
        char *name, *value;
        int c, len;

        if (argc == 1 || *(argv[1]) == '-')
                arp_usage();
        
        /* XXX - total trash */
        if (argc > 1 &&
            (strcmp(argv[1], "show") == 0 || strcmp(argv[1], "get") == 0 ||
                strcmp(argv[1], "add") == 0 || strcmp(argv[1], "delete") == 0))
                return (arp_kern_main(argc, argv));
        
        srand(time(NULL));

        arp = (struct arp_hdr *)buf;
        arp->ar_hrd = htons(ARP_HRD_ETH);
        arp->ar_pro = htons(ARP_PRO_IP);
        arp->ar_hln = ETH_ADDR_LEN;
        arp->ar_pln = IP_ADDR_LEN;
        arp->ar_op = ARP_OP_REQUEST;

        ethip = (struct arp_ethip *)(buf + ARP_HDR_LEN);
        memset(ethip, 0, sizeof(*ethip));

        for (c = 1; c + 1 < argc; c += 2) {
                name = argv[c];
                value = argv[c + 1];
                
                if (strcmp(name, "op") == 0) {
                        if (op_aton(value, &arp->ar_op) < 0)
                                arp_usage();
                } else if (strcmp(name, "sha") == 0) {
                        if (addr_aton(value, &addr) < 0)
                                arp_usage();
                        memcpy(ethip->ar_sha, &addr.addr_eth, ETH_ADDR_LEN);
                } else if (strcmp(name, "spa") == 0) {                  
                        if (addr_aton(value, &addr) < 0)
                                arp_usage();
                        memcpy(ethip->ar_spa, &addr.addr_ip, IP_ADDR_LEN);
                } else if (strcmp(name, "tha") == 0) {
                        if (addr_aton(value, &addr) < 0)
                                arp_usage();
                        memcpy(ethip->ar_tha, &addr.addr_eth, ETH_ADDR_LEN);
                } else if (strcmp(name, "tpa") == 0) {
                        if (addr_aton(value, &addr) < 0)
                                arp_usage();
                        memcpy(ethip->ar_tpa, &addr.addr_ip, IP_ADDR_LEN);
                }
                else
                        arp_usage();
        }
        argc -= c;
        argv += c;

        if (argc != 0)
                arp_usage();

        p = buf + ARP_HDR_LEN + ARP_ETHIP_LEN;
        
        if (!isatty(STDIN_FILENO)) {
                len = sizeof(buf) - (p - buf);
                while ((c = read(STDIN_FILENO, p, len)) > 0) {
                        p += c;
                        len -= c;
                }
        }
        len = p - buf;
        
        if (write(STDOUT_FILENO, buf, len) != len)
                err(1, "write");

        return (0);
}

struct mod mod_arp = {
        "arp",
        MOD_TYPE_ENCAP|MOD_TYPE_KERN,
        arp_main
};

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