474 lines
9.1 KiB
C
474 lines
9.1 KiB
C
/*
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arp.c
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Created: Jan 2001 by Philip Homburg <philip@f-mnx.phicoh.com>
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Manipulate ARP table
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*/
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#define _POSIX_C_SOURCE 2
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#define _NETBSD_SOURCE 1
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#include <errno.h>
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#include <fcntl.h>
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#include <stdarg.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <sys/ioctl.h>
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#include <net/netlib.h>
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#include <net/gen/ether.h>
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#include <net/gen/if_ether.h>
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#include <net/gen/in.h>
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#include <net/gen/inet.h>
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#include <net/gen/ip_io.h>
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#include <net/gen/netdb.h>
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#include <net/gen/socket.h>
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#include <net/gen/arp_io.h>
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char *progname;
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static int ipfd= -1;
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static int do_setuid= 0;
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static void do_open(char *devname);
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static void show_one(char *hostname, int do_num);
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static void show_all(int do_num);
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static void print_one(ipaddr_t ipaddr, nwio_arp_t *arpp, int do_num);
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static void delete_all(void);
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static void delete(char *hostname);
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static void do_set(char *hostname, char *ethername, int temp, int pub,
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int optdelete);
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static ipaddr_t nametoipaddr(char *hostname);
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static void fatal(const char *fmt, ...);
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static void usage(void);
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int main(int argc, char *argv[])
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{
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int c;
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char *hostname, *ethername;
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int do_temp, do_pub;
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int a_flag, d_flag, n_flag, s_flag, S_flag;
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char *I_arg;
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(progname=strrchr(argv[0],'/')) ? progname++ : (progname=argv[0]);
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a_flag= d_flag= n_flag= s_flag= S_flag= 0;
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I_arg= NULL;
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while(c= getopt(argc, argv, "adnsS?I:"), c != -1)
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{
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switch(c)
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{
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case '?': usage();
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case 'a': a_flag= 1; break;
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case 'd': d_flag= 1; break;
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case 'n': n_flag= 1; break;
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case 's': s_flag= 1; break;
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case 'S': S_flag= 1; break;
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case 'I': I_arg= optarg; break;
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default: fatal("getopt failed: '%c'", c);
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}
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}
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hostname= NULL; /* lint */
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ethername= NULL; /* lint */
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do_temp= do_pub= 0; /* lint */
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if (n_flag + d_flag + s_flag + S_flag > 1)
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usage();
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if (s_flag || S_flag)
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{
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if (optind >= argc) usage();
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hostname= argv[optind++];
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if (optind >= argc) usage();
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ethername= argv[optind++];
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do_temp= do_pub= 0;
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while (optind < argc)
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{
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if (strcasecmp(argv[optind], "temp") == 0)
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{
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do_temp= 1;
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optind++;
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continue;
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}
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if (strcasecmp(argv[optind], "pub") == 0)
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{
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do_pub= 1;
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optind++;
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continue;
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}
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usage();
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}
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}
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else if (d_flag)
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{
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if (!a_flag)
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{
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if (optind >= argc)
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usage();
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hostname= argv[optind++];
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if (optind != argc)
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usage();
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}
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}
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else if (a_flag)
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{
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if (optind != argc)
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usage();
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do_setuid= 1;
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}
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else
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{
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if (optind >= argc)
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usage();
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hostname= argv[optind++];
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if (optind != argc)
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usage();
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do_setuid= 1;
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}
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do_open(I_arg);
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if (d_flag)
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{
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if (a_flag)
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delete_all();
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else
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delete(hostname);
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}
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else if (s_flag || S_flag)
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do_set(hostname, ethername, do_temp, do_pub, S_flag);
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else if (a_flag)
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show_all(n_flag);
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else
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show_one(hostname, n_flag);
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exit(0);
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}
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static void do_open(char *devname)
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{
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size_t l;
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char *check;
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if (do_setuid && devname)
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{
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/* Only strings that consist of IP_DEVICE optionally
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* followed by a number are allowed.
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*/
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l= strlen(IP_DEVICE);
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if (strncmp(devname, IP_DEVICE, l) != 0)
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do_setuid= 0;
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else if (strlen(devname) == l)
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; /* OK */
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else
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{
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strtoul(devname+l, &check, 10);
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if (check[0] != '\0')
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do_setuid= 0;
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}
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}
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if (!devname)
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devname= IP_DEVICE;
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if (!do_setuid)
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{
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setuid(getuid());
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setgid(getgid());
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}
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ipfd= open(devname, O_RDWR);
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if (ipfd == -1)
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fatal("unable to open '%s': %s", devname, strerror(errno));
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}
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static void show_one(char *hostname, int do_num)
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{
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int r;
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ipaddr_t ipaddr;
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nwio_arp_t arp;
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ipaddr= nametoipaddr(hostname);
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arp.nwa_ipaddr= ipaddr;
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r= ioctl(ipfd, NWIOARPGIP, &arp);
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if (r == -1 && errno == ENOENT)
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{
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print_one(ipaddr, NULL, do_num);
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exit(1);
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}
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if (r == -1)
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fatal("NWIOARPGIP failed: %s", strerror(errno));
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print_one(ipaddr, &arp, do_num);
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}
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static void show_all(int do_num)
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{
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int ind, max, i, r;
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nwio_arp_t *arptab;
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nwio_arp_t arp;
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/* First get all entries */
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max= 10;
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ind= 0;
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arptab= malloc(max * sizeof(*arptab));
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if (arptab == NULL)
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{
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fatal("out of memory, can't get %d bytes",
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max*sizeof(*arptab));
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}
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arp.nwa_entno= 0;
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for (;;)
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{
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if (ind == max)
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{
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max *= 2;
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arptab= realloc(arptab, max * sizeof(*arptab));
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if (!arptab)
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{
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fatal("out of memory, can't get %d bytes",
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max*sizeof(*arptab));
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}
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}
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r= ioctl(ipfd, NWIOARPGNEXT, &arp);
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if (r == -1 && errno == ENOENT)
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break;
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if (r == -1)
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fatal("NWIOARPGNEXT failed: %s", strerror(errno));
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arptab[ind]= arp;
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ind++;
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}
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for (i= 0; i<ind; i++)
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print_one(0, &arptab[i], do_num);
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}
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static void print_one(ipaddr_t ipaddr, nwio_arp_t *arpp, int do_num)
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{
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u32_t flags;
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struct hostent *he;
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if (arpp)
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ipaddr= arpp->nwa_ipaddr;
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if (!do_num)
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he= gethostbyaddr((char *)&ipaddr, sizeof(ipaddr), AF_INET);
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else
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he= NULL;
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if (he)
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printf("%s (%s)", he->h_name, inet_ntoa(ipaddr));
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else
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printf("%s", inet_ntoa(ipaddr));
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if (!arpp)
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{
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printf(" -- no entry\n");
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return;
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}
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flags= arpp->nwa_flags;
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if (flags & NWAF_INCOMPLETE)
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printf(" is incomplete");
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else if (flags & NWAF_DEAD)
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printf(" is dead");
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else
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{
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printf(" is at %s", ether_ntoa(&arpp->nwa_ethaddr));
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if (flags & NWAF_PERM)
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printf(" permanent");
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if (flags & NWAF_PUB)
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printf(" published");
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}
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printf("\n");
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}
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static void delete_all(void)
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{
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int ind, max, i, r;
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nwio_arp_t *arptab;
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nwio_arp_t arp;
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/* First get all entries */
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max= 10;
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ind= 0;
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arptab= malloc(max * sizeof(*arptab));
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if (arptab == NULL)
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{
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fatal("out of memory, can't get %d bytes",
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max*sizeof(*arptab));
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}
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arp.nwa_entno= 0;
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for (;;)
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{
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if (ind == max)
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{
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max *= 2;
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arptab= realloc(arptab, max * sizeof(*arptab));
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if (arptab == NULL)
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{
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fatal("out of memory, can't get %d bytes",
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max*sizeof(*arptab));
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}
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}
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r= ioctl(ipfd, NWIOARPGNEXT, &arp);
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if (r == -1 && errno == ENOENT)
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break;
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if (r == -1)
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fatal("NWIOARPGNEXT failed: %s", strerror(errno));
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arptab[ind]= arp;
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ind++;
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}
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for (i= 0; i<ind; i++)
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{
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r= ioctl(ipfd, NWIOARPDIP, &arptab[i]);
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if (r == 0)
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continue;
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if (errno == EINVAL || errno == ENOENT)
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{
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/* Entry is incomplete of entry is already deleted */
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continue;
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}
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fatal("unable to delete host %s: %s",
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inet_ntoa(arptab[i].nwa_ipaddr), strerror(errno));
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}
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}
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static void delete(char *hostname)
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{
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int r;
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ipaddr_t ipaddr;
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nwio_arp_t arp;
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ipaddr= nametoipaddr(hostname);
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arp.nwa_ipaddr= ipaddr;
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r= ioctl(ipfd, NWIOARPDIP, &arp);
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if (r == 0)
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return;
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if (errno == ENOENT)
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{
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print_one(ipaddr, NULL, 0);
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exit(1);
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}
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fatal("unable to delete host %s: %s", inet_ntoa(ipaddr),
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errno == EINVAL ? "entry is incomplete" : strerror(errno));
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}
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static void do_set(char *hostname, char *ethername, int temp, int pub,
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int optdelete)
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{
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int r;
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ipaddr_t ipaddr;
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ether_addr_t *eap;
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ether_addr_t ethaddr;
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nwio_arp_t arp;
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nwio_ipconf_t ipconf;
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ipaddr= nametoipaddr(hostname);
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if (pub && strcasecmp(ethername, "auto") == 0)
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{
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r= ioctl(ipfd, NWIOGIPCONF, &ipconf);
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if (r == -1)
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fatal("NWIOGIPCONF failed: %s", strerror(errno));
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arp.nwa_ipaddr= ipconf.nwic_ipaddr;
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r= ioctl(ipfd, NWIOARPGIP, &arp);
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if (r == -1)
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fatal("NWIOARPGIP failed: %s", strerror(errno));
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ethaddr= arp.nwa_ethaddr;
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}
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else if (eap= ether_aton(ethername), eap != NULL)
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ethaddr= *eap;
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else if (ether_hostton(ethername, ðaddr) != 0)
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{
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fatal("unable to parse ethernet address '%s'",
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ethername);
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}
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if (optdelete)
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{
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arp.nwa_ipaddr= ipaddr;
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r= ioctl(ipfd, NWIOARPDIP, &arp);
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if (r == -1 && errno != ENOENT)
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{
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fatal("unable to delete entry for host %s: %s",
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inet_ntoa(ipaddr),
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errno == EINVAL ? "incomplete entry" :
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strerror(errno));
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}
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}
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arp.nwa_ipaddr= ipaddr;
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arp.nwa_ethaddr= ethaddr;
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arp.nwa_flags= 0;
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if (pub)
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arp.nwa_flags |= NWAF_PUB;
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if (!temp)
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arp.nwa_flags |= NWAF_PERM;
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r= ioctl(ipfd, NWIOARPSIP, &arp);
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if (r == -1)
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{
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fatal("unable to set arp entry: %s",
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errno == EEXIST ? "entry exists" : strerror(errno));
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}
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}
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static ipaddr_t nametoipaddr(char *hostname)
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{
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ipaddr_t ipaddr;
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struct hostent *he;
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if (inet_aton(hostname, &ipaddr) == 0)
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{
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he= gethostbyname(hostname);
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if (!he)
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fatal("unknown hostname '%s'", hostname);
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if (he->h_addrtype != AF_INET ||
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he->h_length != sizeof(ipaddr))
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{
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fatal("strange host '%s': addrtype %d, length %d",
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he->h_addrtype, he->h_length);
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}
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memcpy(&ipaddr, he->h_addr, sizeof(ipaddr));
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}
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return ipaddr;
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}
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#if 0
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static char *ether_ntoa(struct ether_addr *eap)
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{
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static char buf[]= "xx:xx:xx:xx:xx:xx";
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sprintf(buf, "%02x:%02x:%02x:%02x:%02x:%02x",
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eap->ea_addr[0], eap->ea_addr[1],
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eap->ea_addr[2], eap->ea_addr[3],
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eap->ea_addr[4], eap->ea_addr[5]);
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return buf;
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}
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#endif
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static void fatal(const char *fmt, ...)
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{
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va_list ap;
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va_start(ap, fmt);
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fprintf(stderr, "%s: ", progname);
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vfprintf(stderr, fmt, ap);
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fprintf(stderr, "\n");
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va_end(ap);
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exit(1);
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}
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static void usage(void)
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{
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fprintf(stderr, "Usage:\tarp [-I ip-dev] [-n] hostname\n"
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"\tarp [-I ip-dev] [-n] -a\n"
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"\tarp [-I ip-dev] -d hostname\n"
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"\tarp [-I ip-dev] -d -a\n"
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"\tarp [-I ip-dev] -s hostname ether-addr [temp] [pub]\n"
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"\tarp [-I ip-dev] -S hostname ether-addr [temp] [pub]\n");
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exit(1);
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}
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/*
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* $PchId: arp.c,v 1.3 2005/01/31 22:31:45 philip Exp $
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*/
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