540 lines
12 KiB
C
540 lines
12 KiB
C
/* $NetBSD: arp.c,v 1.16 1997/03/07 07:04:43 mikel Exp $ */
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/*
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* Copyright (c) 1984, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Sun Microsystems, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#ifndef lint
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static char copyright[] =
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"@(#) Copyright (c) 1984, 1993\n\
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The Regents of the University of California. All rights reserved.\n";
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#endif /* not lint */
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#ifndef lint
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/* static char sccsid[] = "@(#)arp.c 8.3 (Berkeley) 4/28/95"; */
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static char *rcsid = "$NetBSD: arp.c,v 1.16 1997/03/07 07:04:43 mikel Exp $";
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#endif /* not lint */
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/*
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* arp - display, set, and delete arp table entries
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*/
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#include <sys/param.h>
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#include <sys/file.h>
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#include <sys/socket.h>
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#include <sys/sysctl.h>
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#include <net/if.h>
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#include <net/if_dl.h>
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#include <net/if_types.h>
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#include <net/route.h>
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#include <netinet/in.h>
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#include <netinet/if_ether.h>
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#include <arpa/inet.h>
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#include <err.h>
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#include <errno.h>
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#include <netdb.h>
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#include <nlist.h>
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#include <paths.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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static int pid;
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static int nflag;
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static int s = -1;
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int delete __P((const char *, const char *));
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void dump __P((u_long));
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void ether_print __P((const u_char *));
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int file __P((char *));
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void get __P((const char *));
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int getinetaddr __P((const char *, struct in_addr *));
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void getsocket __P((void));
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int rtmsg __P((int));
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int set __P((int, char **));
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void usage __P((void));
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int
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main(argc, argv)
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int argc;
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char **argv;
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{
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int ch;
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int op = 0;
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pid = getpid();
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while ((ch = getopt(argc, argv, "andsf")) != -1)
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switch((char)ch) {
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case 'a':
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case 'd':
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case 's':
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case 'f':
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if (op)
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usage();
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op = ch;
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break;
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case 'n':
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nflag = 1;
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break;
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default:
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usage();
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}
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argc -= optind;
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argv += optind;
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switch((char)op) {
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case 'a':
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dump(0);
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break;
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case 'd':
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if (argc < 1 || argc > 2)
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usage();
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(void)delete(argv[0], argv[1]);
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break;
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case 's':
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if (argc < 2 || argc > 5)
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usage();
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return (set(argc, argv) ? 1 : 0);
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case 'f':
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if (argc != 1)
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usage();
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return (file(argv[0]));
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default:
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if (argc != 1)
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usage();
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get(argv[0]);
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break;
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}
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return (0);
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}
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/*
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* Process a file to set standard arp entries
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*/
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int
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file(name)
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char *name;
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{
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char line[100], arg[5][50], *args[5];
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int i, retval;
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FILE *fp;
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if ((fp = fopen(name, "r")) == NULL)
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err(1, "cannot open %s", name);
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args[0] = &arg[0][0];
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args[1] = &arg[1][0];
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args[2] = &arg[2][0];
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args[3] = &arg[3][0];
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args[4] = &arg[4][0];
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retval = 0;
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while (fgets(line, 100, fp) != NULL) {
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i = sscanf(line, "%s %s %s %s %s", arg[0], arg[1], arg[2],
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arg[3], arg[4]);
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if (i < 2) {
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warnx("bad line: %s", line);
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retval = 1;
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continue;
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}
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if (set(i, args))
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retval = 1;
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}
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fclose(fp);
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return (retval);
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}
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void
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getsocket()
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{
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if (s >= 0)
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return;
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s = socket(PF_ROUTE, SOCK_RAW, 0);
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if (s < 0)
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err(1, "socket");
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}
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struct sockaddr_in so_mask = {8, 0, 0, { 0xffffffff}};
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struct sockaddr_inarp blank_sin = {sizeof(blank_sin), AF_INET }, sin_m;
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struct sockaddr_dl blank_sdl = {sizeof(blank_sdl), AF_LINK }, sdl_m;
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int expire_time, flags, export_only, doing_proxy, found_entry;
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struct {
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struct rt_msghdr m_rtm;
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char m_space[512];
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} m_rtmsg;
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/*
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* Set an individual arp entry
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*/
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int
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set(argc, argv)
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int argc;
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char **argv;
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{
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register struct sockaddr_inarp *sin;
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register struct sockaddr_dl *sdl;
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register struct rt_msghdr *rtm;
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struct ether_addr *ea;
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char *host = argv[0], *eaddr;
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sin = &sin_m;
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rtm = &(m_rtmsg.m_rtm);
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eaddr = argv[1];
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getsocket();
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argc -= 2;
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argv += 2;
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sdl_m = blank_sdl; /* struct copy */
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sin_m = blank_sin; /* struct copy */
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if (getinetaddr(host, &sin->sin_addr) == -1)
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return (1);
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ea = ether_aton(eaddr);
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if (ea != NULL) {
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(void)memcpy(LLADDR(&sdl_m), ea, sizeof(struct ether_addr));
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sdl_m.sdl_alen = sizeof(struct ether_addr);
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}
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else
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warnx("invalid Ethernet address '%s'", eaddr);
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doing_proxy = flags = export_only = expire_time = 0;
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while (argc-- > 0) {
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if (strncmp(argv[0], "temp", 4) == 0) {
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struct timeval time;
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(void)gettimeofday(&time, 0);
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expire_time = time.tv_sec + 20 * 60;
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}
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else if (strncmp(argv[0], "pub", 3) == 0) {
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flags |= RTF_ANNOUNCE;
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doing_proxy = SIN_PROXY;
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} else if (strncmp(argv[0], "trail", 5) == 0) {
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(void)printf(
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"%s: Sending trailers is no longer supported\n",
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host);
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}
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argv++;
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}
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tryagain:
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if (rtmsg(RTM_GET) < 0) {
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warn("%s", host);
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return (1);
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}
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sin = (struct sockaddr_inarp *)(rtm + 1);
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sdl = (struct sockaddr_dl *)(sin->sin_len + (char *)sin);
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if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) {
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if (sdl->sdl_family == AF_LINK &&
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(rtm->rtm_flags & RTF_LLINFO) &&
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!(rtm->rtm_flags & RTF_GATEWAY)) switch (sdl->sdl_type) {
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case IFT_ETHER: case IFT_FDDI: case IFT_ISO88023:
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case IFT_ISO88024: case IFT_ISO88025:
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goto overwrite;
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}
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if (doing_proxy == 0) {
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(void)printf("set: can only proxy for %s\n", host);
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return (1);
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}
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if (sin_m.sin_other & SIN_PROXY) {
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(void)printf(
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"set: proxy entry exists for non 802 device\n");
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return (1);
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}
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sin_m.sin_other = SIN_PROXY;
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export_only = 1;
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goto tryagain;
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}
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overwrite:
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if (sdl->sdl_family != AF_LINK) {
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(void)printf("cannot intuit interface index and type for %s\n",
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host);
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return (1);
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}
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sdl_m.sdl_type = sdl->sdl_type;
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sdl_m.sdl_index = sdl->sdl_index;
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return (rtmsg(RTM_ADD));
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}
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/*
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* Display an individual arp entry
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*/
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void
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get(host)
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const char *host;
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{
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struct sockaddr_inarp *sin;
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sin = &sin_m;
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sin_m = blank_sin; /* struct copy */
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if (getinetaddr(host, &sin->sin_addr) == -1)
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exit(1);
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dump(sin->sin_addr.s_addr);
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if (found_entry == 0) {
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(void)printf("%s (%s) -- no entry\n", host,
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inet_ntoa(sin->sin_addr));
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exit(1);
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}
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}
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/*
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* Delete an arp entry
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*/
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int
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delete(host, info)
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const char *host;
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const char *info;
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{
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register struct sockaddr_inarp *sin;
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register struct rt_msghdr *rtm;
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struct sockaddr_dl *sdl;
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sin = &sin_m;
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rtm = &m_rtmsg.m_rtm;
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if (info && strncmp(info, "pro", 3) )
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export_only = 1;
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getsocket();
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sin_m = blank_sin; /* struct copy */
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if (getinetaddr(host, &sin->sin_addr) == -1)
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return (1);
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tryagain:
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if (rtmsg(RTM_GET) < 0) {
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warn("%s", host);
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return (1);
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}
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sin = (struct sockaddr_inarp *)(rtm + 1);
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sdl = (struct sockaddr_dl *)(sin->sin_len + (char *)sin);
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if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) {
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if (sdl->sdl_family == AF_LINK &&
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(rtm->rtm_flags & RTF_LLINFO) &&
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!(rtm->rtm_flags & RTF_GATEWAY)) switch (sdl->sdl_type) {
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case IFT_ETHER: case IFT_FDDI: case IFT_ISO88023:
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case IFT_ISO88024: case IFT_ISO88025:
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goto delete;
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}
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}
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if (sin_m.sin_other & SIN_PROXY) {
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warnx("delete: can't locate %s", host);
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return (1);
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} else {
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sin_m.sin_other = SIN_PROXY;
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goto tryagain;
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}
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delete:
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if (sdl->sdl_family != AF_LINK) {
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(void)printf("cannot locate %s\n", host);
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return (1);
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}
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if (rtmsg(RTM_DELETE))
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return (1);
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(void)printf("%s (%s) deleted\n", host, inet_ntoa(sin->sin_addr));
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return (0);
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}
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/*
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* Dump the entire arp table
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*/
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void
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dump(addr)
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u_long addr;
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{
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int mib[6];
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size_t needed;
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char *host, *lim, *buf, *next;
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struct rt_msghdr *rtm;
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struct sockaddr_inarp *sin;
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struct sockaddr_dl *sdl;
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extern int h_errno;
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struct hostent *hp;
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mib[0] = CTL_NET;
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mib[1] = PF_ROUTE;
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mib[2] = 0;
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mib[3] = AF_INET;
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mib[4] = NET_RT_FLAGS;
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mib[5] = RTF_LLINFO;
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if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
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err(1, "route-sysctl-estimate");
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if ((buf = malloc(needed)) == NULL)
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err(1, "malloc");
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if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
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err(1, "actual retrieval of routing table");
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lim = buf + needed;
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for (next = buf; next < lim; next += rtm->rtm_msglen) {
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rtm = (struct rt_msghdr *)next;
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sin = (struct sockaddr_inarp *)(rtm + 1);
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sdl = (struct sockaddr_dl *)(sin + 1);
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if (addr) {
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if (addr != sin->sin_addr.s_addr)
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continue;
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found_entry = 1;
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}
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if (nflag == 0)
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hp = gethostbyaddr((caddr_t)&(sin->sin_addr),
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sizeof sin->sin_addr, AF_INET);
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else
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hp = 0;
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if (hp)
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host = hp->h_name;
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else {
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host = "?";
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if (h_errno == TRY_AGAIN)
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nflag = 1;
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}
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(void)printf("%s (%s) at ", host, inet_ntoa(sin->sin_addr));
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if (sdl->sdl_alen)
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ether_print((u_char *)LLADDR(sdl));
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else
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(void)printf("(incomplete)");
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if (rtm->rtm_rmx.rmx_expire == 0)
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(void)printf(" permanent");
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if (sin->sin_other & SIN_PROXY)
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(void)printf(" published (proxy only)");
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if (rtm->rtm_addrs & RTA_NETMASK) {
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sin = (struct sockaddr_inarp *)
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(sdl->sdl_len + (char *)sdl);
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if (sin->sin_addr.s_addr == 0xffffffff)
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(void)printf(" published");
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if (sin->sin_len != 8)
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(void)printf("(wierd)");
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}
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(void)printf("\n");
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}
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}
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void
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ether_print(cp)
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const u_char *cp;
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{
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(void)printf("%x:%x:%x:%x:%x:%x", cp[0], cp[1], cp[2], cp[3], cp[4],
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cp[5]);
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}
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void
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usage()
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{
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(void)fprintf(stderr, "usage: arp [-n] hostname\n");
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(void)fprintf(stderr, "usage: arp [-n] -a\n");
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(void)fprintf(stderr, "usage: arp -d hostname\n");
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(void)fprintf(stderr,
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"usage: arp -s hostname ether_addr [temp] [pub]\n");
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(void)fprintf(stderr, "usage: arp -f filename\n");
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exit(1);
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}
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int
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rtmsg(cmd)
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int cmd;
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{
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static int seq;
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int rlen;
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register struct rt_msghdr *rtm;
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register char *cp;
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register int l;
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rtm = &m_rtmsg.m_rtm;
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cp = m_rtmsg.m_space;
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errno = 0;
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if (cmd == RTM_DELETE)
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goto doit;
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(void)memset(&m_rtmsg, 0, sizeof(m_rtmsg));
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rtm->rtm_flags = flags;
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rtm->rtm_version = RTM_VERSION;
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switch (cmd) {
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default:
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errx(1, "internal wrong cmd");
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/*NOTREACHED*/
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case RTM_ADD:
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rtm->rtm_addrs |= RTA_GATEWAY;
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rtm->rtm_rmx.rmx_expire = expire_time;
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rtm->rtm_inits = RTV_EXPIRE;
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rtm->rtm_flags |= (RTF_HOST | RTF_STATIC);
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sin_m.sin_other = 0;
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if (doing_proxy) {
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if (export_only)
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sin_m.sin_other = SIN_PROXY;
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else {
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rtm->rtm_addrs |= RTA_NETMASK;
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rtm->rtm_flags &= ~RTF_HOST;
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}
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}
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/* FALLTHROUGH */
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case RTM_GET:
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rtm->rtm_addrs |= RTA_DST;
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}
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#define NEXTADDR(w, s) \
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if (rtm->rtm_addrs & (w)) { \
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(void)memcpy(cp, &s, sizeof(s)); cp += sizeof(s);}
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NEXTADDR(RTA_DST, sin_m);
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NEXTADDR(RTA_GATEWAY, sdl_m);
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NEXTADDR(RTA_NETMASK, so_mask);
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rtm->rtm_msglen = cp - (char *)&m_rtmsg;
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doit:
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l = rtm->rtm_msglen;
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rtm->rtm_seq = ++seq;
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rtm->rtm_type = cmd;
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if ((rlen = write(s, (char *)&m_rtmsg, l)) < 0) {
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if (errno != ESRCH || cmd != RTM_DELETE) {
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warn("writing to routing socket");
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return (-1);
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}
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|
}
|
|
do {
|
|
l = read(s, (char *)&m_rtmsg, sizeof(m_rtmsg));
|
|
} while (l > 0 && (rtm->rtm_seq != seq || rtm->rtm_pid != pid));
|
|
if (l < 0)
|
|
warn("read from routing socket");
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
getinetaddr(host, inap)
|
|
const char *host;
|
|
struct in_addr *inap;
|
|
{
|
|
struct hostent *hp;
|
|
|
|
if (inet_aton(host, inap) == 1)
|
|
return (0);
|
|
if ((hp = gethostbyname(host)) == NULL) {
|
|
warnx("%s: %s\n", host, hstrerror(h_errno));
|
|
return (-1);
|
|
}
|
|
(void)memcpy(inap, hp->h_addr, sizeof(*inap));
|
|
return (0);
|
|
}
|