e901286aad
than the first address assigned. This gives slightly different behaviour in the presence of aliases. From Bill Fenner, via Pete Bentley.
896 lines
24 KiB
C
896 lines
24 KiB
C
/* $NetBSD: if_ether.c,v 1.31 1996/05/11 12:59:58 mycroft Exp $ */
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/*
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* Copyright (c) 1982, 1986, 1988, 1993
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* The Regents of the University of California. All rights reserved.
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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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* @(#)if_ether.c 8.1 (Berkeley) 6/10/93
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*/
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/*
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* Ethernet address resolution protocol.
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* TODO:
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* add "inuse/lock" bit (or ref. count) along with valid bit
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*/
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#ifdef INET
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/malloc.h>
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#include <sys/mbuf.h>
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#include <sys/socket.h>
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#include <sys/time.h>
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#include <sys/kernel.h>
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#include <sys/errno.h>
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#include <sys/ioctl.h>
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#include <sys/syslog.h>
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#include <sys/proc.h>
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#include <net/if.h>
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#include <net/if_dl.h>
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#include <net/route.h>
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#include <netinet/in.h>
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#include <netinet/in_systm.h>
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#include <netinet/in_var.h>
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#include <netinet/ip.h>
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#include <netinet/if_ether.h>
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#define SIN(s) ((struct sockaddr_in *)s)
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#define SDL(s) ((struct sockaddr_dl *)s)
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#define SRP(s) ((struct sockaddr_inarp *)s)
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/*
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* ARP trailer negotiation. Trailer protocol is not IP specific,
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* but ARP request/response use IP addresses.
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*/
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#define ETHERTYPE_IPTRAILERS ETHERTYPE_TRAIL
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/* timer values */
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int arpt_prune = (5*60*1); /* walk list every 5 minutes */
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int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */
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int arpt_down = 20; /* once declared down, don't send for 20 secs */
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#define rt_expire rt_rmx.rmx_expire
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static void arprequest
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__P((struct arpcom *, u_int32_t *, u_int32_t *, u_int8_t *));
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static void arptfree __P((struct llinfo_arp *));
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static void arptimer __P((void *));
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static struct llinfo_arp *arplookup __P((u_int32_t, int, int));
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static void in_arpinput __P((struct mbuf *));
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extern struct ifnet loif;
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LIST_HEAD(, llinfo_arp) llinfo_arp;
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struct ifqueue arpintrq = {0, 0, 0, 50};
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int arp_inuse, arp_allocated, arp_intimer;
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int arp_maxtries = 5;
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int useloopback = 1; /* use loopback interface for local traffic */
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int arpinit_done = 0;
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/* revarp state */
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static struct in_addr myip, srv_ip;
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static int myip_initialized = 0;
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static int revarp_in_progress = 0;
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static struct ifnet *myip_ifp = NULL;
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static void arptimer __P((void *));
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static void arprequest __P((struct arpcom *, u_int32_t *, u_int32_t *,
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u_int8_t *));
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static void in_arpinput __P((struct mbuf *));
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static void arptfree __P((struct llinfo_arp *));
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static struct llinfo_arp *arplookup __P((u_int32_t, int, int ));
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#ifdef DDB
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static void db_print_sa __P((struct sockaddr *));
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static void db_print_ifa __P((struct ifaddr *));
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static void db_print_llinfo __P((caddr_t));
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static int db_show_radix_node __P((struct radix_node *, void *));
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#endif
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/*
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* Timeout routine. Age arp_tab entries periodically.
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*/
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/* ARGSUSED */
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static void
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arptimer(arg)
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void *arg;
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{
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int s;
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register struct llinfo_arp *la, *nla;
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s = splsoftnet();
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timeout(arptimer, NULL, arpt_prune * hz);
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for (la = llinfo_arp.lh_first; la != 0; la = nla) {
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register struct rtentry *rt = la->la_rt;
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nla = la->la_list.le_next;
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if (rt->rt_expire && rt->rt_expire <= time.tv_sec)
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arptfree(la); /* timer has expired; clear */
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}
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splx(s);
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}
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/*
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* Parallel to llc_rtrequest.
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*/
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void
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arp_rtrequest(req, rt, sa)
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int req;
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register struct rtentry *rt;
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struct sockaddr *sa;
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{
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register struct sockaddr *gate = rt->rt_gateway;
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register struct llinfo_arp *la = (struct llinfo_arp *)rt->rt_llinfo;
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static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
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if (!arpinit_done) {
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arpinit_done = 1;
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/*
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* We generate expiration times from time.tv_sec
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* so avoid accidently creating permanent routes.
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*/
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if (time.tv_sec == 0) {
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time.tv_sec++;
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}
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timeout(arptimer, (caddr_t)0, hz);
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}
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if (rt->rt_flags & RTF_GATEWAY)
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return;
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switch (req) {
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case RTM_ADD:
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/*
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* XXX: If this is a manually added route to interface
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* such as older version of routed or gated might provide,
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* restore cloning bit.
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*/
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if ((rt->rt_flags & RTF_HOST) == 0 &&
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SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff)
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rt->rt_flags |= RTF_CLONING;
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if (rt->rt_flags & RTF_CLONING) {
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/*
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* Case 1: This route should come from a route to iface.
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*/
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rt_setgate(rt, rt_key(rt),
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(struct sockaddr *)&null_sdl);
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gate = rt->rt_gateway;
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SDL(gate)->sdl_type = rt->rt_ifp->if_type;
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SDL(gate)->sdl_index = rt->rt_ifp->if_index;
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/*
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* Give this route an expiration time, even though
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* it's a "permanent" route, so that routes cloned
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* from it do not need their expiration time set.
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*/
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rt->rt_expire = time.tv_sec;
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break;
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}
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/* Announce a new entry if requested. */
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if (rt->rt_flags & RTF_ANNOUNCE)
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arprequest((struct arpcom *)rt->rt_ifp,
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&SIN(rt_key(rt))->sin_addr.s_addr,
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&SIN(rt_key(rt))->sin_addr.s_addr,
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(u_char *)LLADDR(SDL(gate)));
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/*FALLTHROUGH*/
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case RTM_RESOLVE:
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if (gate->sa_family != AF_LINK ||
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gate->sa_len < sizeof(null_sdl)) {
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log(LOG_DEBUG, "arp_rtrequest: bad gateway value");
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break;
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}
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SDL(gate)->sdl_type = rt->rt_ifp->if_type;
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SDL(gate)->sdl_index = rt->rt_ifp->if_index;
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if (la != 0)
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break; /* This happens on a route change */
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/*
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* Case 2: This route may come from cloning, or a manual route
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* add with a LL address.
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*/
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R_Malloc(la, struct llinfo_arp *, sizeof(*la));
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rt->rt_llinfo = (caddr_t)la;
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if (la == 0) {
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log(LOG_DEBUG, "arp_rtrequest: malloc failed\n");
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break;
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}
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arp_inuse++, arp_allocated++;
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Bzero(la, sizeof(*la));
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la->la_rt = rt;
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rt->rt_flags |= RTF_LLINFO;
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LIST_INSERT_HEAD(&llinfo_arp, la, la_list);
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if (SIN(rt_key(rt))->sin_addr.s_addr ==
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(IA_SIN(rt->rt_ifa))->sin_addr.s_addr) {
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/*
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* This test used to be
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* if (loif.if_flags & IFF_UP)
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* It allowed local traffic to be forced through
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* the hardware by configuring the loopback down.
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* However, it causes problems during network
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* configuration for boards that can't receive
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* packets they send. It is now necessary to clear
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* "useloopback" and remove the route to force
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* traffic out to the hardware.
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*/
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rt->rt_expire = 0;
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Bcopy(((struct arpcom *)rt->rt_ifp)->ac_enaddr,
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LLADDR(SDL(gate)),
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SDL(gate)->sdl_alen = ETHER_ADDR_LEN);
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if (useloopback)
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rt->rt_ifp = &loif;
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}
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break;
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case RTM_DELETE:
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if (la == 0)
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break;
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arp_inuse--;
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LIST_REMOVE(la, la_list);
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rt->rt_llinfo = 0;
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rt->rt_flags &= ~RTF_LLINFO;
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if (la->la_hold)
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m_freem(la->la_hold);
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Free((caddr_t)la);
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}
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}
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/*
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* Broadcast an ARP request. Caller specifies:
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* - arp header source ip address
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* - arp header target ip address
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* - arp header source ethernet address
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*/
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static void
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arprequest(ac, sip, tip, enaddr)
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register struct arpcom *ac;
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register u_int32_t *sip, *tip;
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register u_int8_t *enaddr;
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{
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register struct mbuf *m;
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register struct ether_header *eh;
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register struct ether_arp *ea;
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struct sockaddr sa;
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if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
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return;
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m->m_len = sizeof(*ea);
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m->m_pkthdr.len = sizeof(*ea);
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MH_ALIGN(m, sizeof(*ea));
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ea = mtod(m, struct ether_arp *);
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eh = (struct ether_header *)sa.sa_data;
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bzero((caddr_t)ea, sizeof (*ea));
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bcopy((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
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sizeof(eh->ether_dhost));
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eh->ether_type = htons(ETHERTYPE_ARP); /* if_output will not swap */
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ea->arp_hrd = htons(ARPHRD_ETHER);
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ea->arp_pro = htons(ETHERTYPE_IP);
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ea->arp_hln = sizeof(ea->arp_sha); /* hardware address length */
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ea->arp_pln = sizeof(ea->arp_spa); /* protocol address length */
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ea->arp_op = htons(ARPOP_REQUEST);
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bcopy((caddr_t)enaddr, (caddr_t)ea->arp_sha, sizeof(ea->arp_sha));
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bcopy((caddr_t)sip, (caddr_t)ea->arp_spa, sizeof(ea->arp_spa));
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bcopy((caddr_t)tip, (caddr_t)ea->arp_tpa, sizeof(ea->arp_tpa));
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sa.sa_family = AF_UNSPEC;
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sa.sa_len = sizeof(sa);
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(*ac->ac_if.if_output)(&ac->ac_if, m, &sa, (struct rtentry *)0);
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}
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/*
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* Resolve an IP address into an ethernet address. If success,
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* desten is filled in. If there is no entry in arptab,
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* set one up and broadcast a request for the IP address.
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* Hold onto this mbuf and resend it once the address
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* is finally resolved. A return value of 1 indicates
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* that desten has been filled in and the packet should be sent
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* normally; a 0 return indicates that the packet has been
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* taken over here, either now or for later transmission.
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*/
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int
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arpresolve(ac, rt, m, dst, desten)
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register struct arpcom *ac;
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register struct rtentry *rt;
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struct mbuf *m;
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register struct sockaddr *dst;
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register u_char *desten;
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{
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register struct llinfo_arp *la;
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struct sockaddr_dl *sdl;
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if (m->m_flags & M_BCAST) { /* broadcast */
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bcopy((caddr_t)etherbroadcastaddr, (caddr_t)desten,
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sizeof(etherbroadcastaddr));
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return (1);
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}
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if (m->m_flags & M_MCAST) { /* multicast */
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ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten);
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return (1);
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}
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if (rt)
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la = (struct llinfo_arp *)rt->rt_llinfo;
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else {
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if ((la = arplookup(SIN(dst)->sin_addr.s_addr, 1, 0)) != NULL)
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rt = la->la_rt;
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}
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if (la == 0 || rt == 0) {
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log(LOG_DEBUG, "arpresolve: can't allocate llinfo");
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m_freem(m);
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return (0);
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}
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sdl = SDL(rt->rt_gateway);
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/*
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* Check the address family and length is valid, the address
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* is resolved; otherwise, try to resolve.
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*/
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if ((rt->rt_expire == 0 || rt->rt_expire > time.tv_sec) &&
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sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) {
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bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
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return 1;
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}
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/*
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* There is an arptab entry, but no ethernet address
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* response yet. Replace the held mbuf with this
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* latest one.
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*/
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if (la->la_hold)
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m_freem(la->la_hold);
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la->la_hold = m;
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/*
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* Re-send the ARP request when appropriate.
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*/
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#ifdef DIAGNOSTIC
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if (rt->rt_expire == 0) {
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/* This should never happen. (Should it? -gwr) */
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printf("arpresolve: unresolved and rt_expire == 0\n");
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/* Set expiration time to now (expired). */
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rt->rt_expire = time.tv_sec;
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}
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#endif
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if (rt->rt_expire) {
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rt->rt_flags &= ~RTF_REJECT;
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if (la->la_asked == 0 || rt->rt_expire != time.tv_sec) {
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rt->rt_expire = time.tv_sec;
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if (la->la_asked++ < arp_maxtries)
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arprequest(ac,
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&(SIN(rt->rt_ifa->ifa_addr)->sin_addr.s_addr),
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&(SIN(dst)->sin_addr.s_addr),
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ac->ac_enaddr);
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else {
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rt->rt_flags |= RTF_REJECT;
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rt->rt_expire += arpt_down;
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la->la_asked = 0;
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}
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}
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}
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return (0);
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}
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/*
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* Common length and type checks are done here,
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* then the protocol-specific routine is called.
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*/
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void
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arpintr()
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{
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register struct mbuf *m;
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register struct arphdr *ar;
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int s;
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while (arpintrq.ifq_head) {
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s = splimp();
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IF_DEQUEUE(&arpintrq, m);
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splx(s);
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if (m == 0 || (m->m_flags & M_PKTHDR) == 0)
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panic("arpintr");
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if (m->m_len >= sizeof(struct arphdr) &&
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(ar = mtod(m, struct arphdr *)) &&
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ntohs(ar->ar_hrd) == ARPHRD_ETHER &&
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m->m_len >=
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sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln))
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switch (ntohs(ar->ar_pro)) {
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case ETHERTYPE_IP:
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case ETHERTYPE_IPTRAILERS:
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in_arpinput(m);
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continue;
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}
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m_freem(m);
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}
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}
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/*
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* ARP for Internet protocols on 10 Mb/s Ethernet.
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* Algorithm is that given in RFC 826.
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* In addition, a sanity check is performed on the sender
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* protocol address, to catch impersonators.
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* We no longer handle negotiations for use of trailer protocol:
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* Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent
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* along with IP replies if we wanted trailers sent to us,
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* and also sent them in response to IP replies.
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* This allowed either end to announce the desire to receive
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* trailer packets.
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* We no longer reply to requests for ETHERTYPE_TRAIL protocol either,
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* but formerly didn't normally send requests.
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*/
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static void
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in_arpinput(m)
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struct mbuf *m;
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{
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register struct ether_arp *ea;
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register struct arpcom *ac = (struct arpcom *)m->m_pkthdr.rcvif;
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struct ether_header *eh;
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register struct llinfo_arp *la = 0;
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register struct rtentry *rt;
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struct in_ifaddr *ia, *maybe_ia = 0;
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struct sockaddr_dl *sdl;
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struct sockaddr sa;
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struct in_addr isaddr, itaddr, myaddr;
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int op;
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ea = mtod(m, struct ether_arp *);
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op = ntohs(ea->arp_op);
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bcopy((caddr_t)ea->arp_spa, (caddr_t)&isaddr, sizeof (isaddr));
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bcopy((caddr_t)ea->arp_tpa, (caddr_t)&itaddr, sizeof (itaddr));
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for (ia = in_ifaddr.tqh_first; ia != 0; ia = ia->ia_list.tqe_next)
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if (ia->ia_ifp == &ac->ac_if) {
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maybe_ia = ia;
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if (itaddr.s_addr == ia->ia_addr.sin_addr.s_addr ||
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isaddr.s_addr == ia->ia_addr.sin_addr.s_addr)
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break;
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}
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if (maybe_ia == 0)
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goto out;
|
||
myaddr = ia ? ia->ia_addr.sin_addr : maybe_ia->ia_addr.sin_addr;
|
||
if (!bcmp((caddr_t)ea->arp_sha, (caddr_t)ac->ac_enaddr,
|
||
sizeof (ea->arp_sha)))
|
||
goto out; /* it's from me, ignore it. */
|
||
if (!bcmp((caddr_t)ea->arp_sha, (caddr_t)etherbroadcastaddr,
|
||
sizeof (ea->arp_sha))) {
|
||
log(LOG_ERR,
|
||
"arp: ether address is broadcast for IP address %x!\n",
|
||
ntohl(isaddr.s_addr));
|
||
goto out;
|
||
}
|
||
if (isaddr.s_addr == myaddr.s_addr) {
|
||
log(LOG_ERR,
|
||
"duplicate IP address %08x sent from ethernet address %s\n",
|
||
ntohl(isaddr.s_addr), ether_sprintf(ea->arp_sha));
|
||
itaddr = myaddr;
|
||
goto reply;
|
||
}
|
||
la = arplookup(isaddr.s_addr, itaddr.s_addr == myaddr.s_addr, 0);
|
||
if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) {
|
||
if (sdl->sdl_alen &&
|
||
bcmp((caddr_t)ea->arp_sha, LLADDR(sdl), sdl->sdl_alen))
|
||
log(LOG_INFO, "arp info overwritten for %08x by %s\n",
|
||
ntohl(isaddr.s_addr), ether_sprintf(ea->arp_sha));
|
||
bcopy((caddr_t)ea->arp_sha, LLADDR(sdl),
|
||
sdl->sdl_alen = sizeof(ea->arp_sha));
|
||
if (rt->rt_expire)
|
||
rt->rt_expire = time.tv_sec + arpt_keep;
|
||
rt->rt_flags &= ~RTF_REJECT;
|
||
la->la_asked = 0;
|
||
if (la->la_hold) {
|
||
(*ac->ac_if.if_output)(&ac->ac_if, la->la_hold,
|
||
rt_key(rt), rt);
|
||
la->la_hold = 0;
|
||
}
|
||
}
|
||
reply:
|
||
if (op != ARPOP_REQUEST) {
|
||
out:
|
||
m_freem(m);
|
||
return;
|
||
}
|
||
if (itaddr.s_addr == myaddr.s_addr) {
|
||
/* I am the target */
|
||
bcopy((caddr_t)ea->arp_sha, (caddr_t)ea->arp_tha,
|
||
sizeof(ea->arp_sha));
|
||
bcopy((caddr_t)ac->ac_enaddr, (caddr_t)ea->arp_sha,
|
||
sizeof(ea->arp_sha));
|
||
} else {
|
||
la = arplookup(itaddr.s_addr, 0, SIN_PROXY);
|
||
if (la == 0)
|
||
goto out;
|
||
rt = la->la_rt;
|
||
bcopy((caddr_t)ea->arp_sha, (caddr_t)ea->arp_tha,
|
||
sizeof(ea->arp_sha));
|
||
sdl = SDL(rt->rt_gateway);
|
||
bcopy(LLADDR(sdl), (caddr_t)ea->arp_sha, sizeof(ea->arp_sha));
|
||
}
|
||
|
||
bcopy((caddr_t)ea->arp_spa, (caddr_t)ea->arp_tpa, sizeof(ea->arp_spa));
|
||
bcopy((caddr_t)&itaddr, (caddr_t)ea->arp_spa, sizeof(ea->arp_spa));
|
||
ea->arp_op = htons(ARPOP_REPLY);
|
||
ea->arp_pro = htons(ETHERTYPE_IP); /* let's be sure! */
|
||
eh = (struct ether_header *)sa.sa_data;
|
||
bcopy((caddr_t)ea->arp_tha, (caddr_t)eh->ether_dhost,
|
||
sizeof(eh->ether_dhost));
|
||
eh->ether_type = htons(ETHERTYPE_ARP);
|
||
sa.sa_family = AF_UNSPEC;
|
||
sa.sa_len = sizeof(sa);
|
||
(*ac->ac_if.if_output)(&ac->ac_if, m, &sa, (struct rtentry *)0);
|
||
return;
|
||
}
|
||
|
||
/*
|
||
* Free an arp entry.
|
||
*/
|
||
static void
|
||
arptfree(la)
|
||
register struct llinfo_arp *la;
|
||
{
|
||
register struct rtentry *rt = la->la_rt;
|
||
register struct sockaddr_dl *sdl;
|
||
|
||
if (rt == 0)
|
||
panic("arptfree");
|
||
if (rt->rt_refcnt > 0 && (sdl = SDL(rt->rt_gateway)) &&
|
||
sdl->sdl_family == AF_LINK) {
|
||
sdl->sdl_alen = 0;
|
||
la->la_asked = 0;
|
||
rt->rt_flags &= ~RTF_REJECT;
|
||
return;
|
||
}
|
||
rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, rt_mask(rt),
|
||
0, (struct rtentry **)0);
|
||
}
|
||
|
||
/*
|
||
* Lookup or enter a new address in arptab.
|
||
*/
|
||
static struct llinfo_arp *
|
||
arplookup(addr, create, proxy)
|
||
u_int32_t addr;
|
||
int create, proxy;
|
||
{
|
||
register struct rtentry *rt;
|
||
static struct sockaddr_inarp sin;
|
||
|
||
sin.sin_len = sizeof(sin);
|
||
sin.sin_family = AF_INET;
|
||
sin.sin_addr.s_addr = addr;
|
||
sin.sin_other = proxy ? SIN_PROXY : 0;
|
||
rt = rtalloc1(sintosa(&sin), create);
|
||
if (rt == 0)
|
||
return (0);
|
||
rt->rt_refcnt--;
|
||
if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 ||
|
||
rt->rt_gateway->sa_family != AF_LINK) {
|
||
if (create)
|
||
log(LOG_DEBUG, "arplookup: unable to enter address for %x\n", ntohl(addr));
|
||
return (0);
|
||
}
|
||
return ((struct llinfo_arp *)rt->rt_llinfo);
|
||
}
|
||
|
||
int
|
||
arpioctl(cmd, data)
|
||
u_long cmd;
|
||
caddr_t data;
|
||
{
|
||
|
||
return (EOPNOTSUPP);
|
||
}
|
||
|
||
void
|
||
arp_ifinit(ac, ifa)
|
||
struct arpcom *ac;
|
||
struct ifaddr *ifa;
|
||
{
|
||
|
||
/* Warn the user if another station has this IP address. */
|
||
arprequest(ac,
|
||
&(IA_SIN(ifa)->sin_addr.s_addr),
|
||
&(IA_SIN(ifa)->sin_addr.s_addr),
|
||
ac->ac_enaddr);
|
||
ifa->ifa_rtrequest = arp_rtrequest;
|
||
ifa->ifa_flags |= RTF_CLONING;
|
||
}
|
||
|
||
/*
|
||
* Called from 10 Mb/s Ethernet interrupt handlers
|
||
* when ether packet type ETHERTYPE_REVARP
|
||
* is received. Common length and type checks are done here,
|
||
* then the protocol-specific routine is called.
|
||
*/
|
||
void
|
||
revarpinput(m)
|
||
struct mbuf *m;
|
||
{
|
||
struct arphdr *ar;
|
||
|
||
if (m->m_len < sizeof(struct arphdr))
|
||
goto out;
|
||
ar = mtod(m, struct arphdr *);
|
||
if (ntohs(ar->ar_hrd) != ARPHRD_ETHER)
|
||
goto out;
|
||
if (m->m_len < sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln))
|
||
goto out;
|
||
switch (ntohs(ar->ar_pro)) {
|
||
|
||
case ETHERTYPE_IP:
|
||
case ETHERTYPE_IPTRAILERS:
|
||
in_revarpinput(m);
|
||
return;
|
||
|
||
default:
|
||
break;
|
||
}
|
||
out:
|
||
m_freem(m);
|
||
}
|
||
|
||
/*
|
||
* RARP for Internet protocols on 10 Mb/s Ethernet.
|
||
* Algorithm is that given in RFC 903.
|
||
* We are only using for bootstrap purposes to get an ip address for one of
|
||
* our interfaces. Thus we support no user-interface.
|
||
*
|
||
* Since the contents of the RARP reply are specific to the interface that
|
||
* sent the request, this code must ensure that they are properly associated.
|
||
*
|
||
* Note: also supports ARP via RARP packets, per the RFC.
|
||
*/
|
||
void
|
||
in_revarpinput(m)
|
||
struct mbuf *m;
|
||
{
|
||
struct ifnet *ifp;
|
||
struct ether_arp *ar;
|
||
int op;
|
||
|
||
ar = mtod(m, struct ether_arp *);
|
||
op = ntohs(ar->arp_op);
|
||
switch (op) {
|
||
case ARPOP_REQUEST:
|
||
case ARPOP_REPLY: /* per RFC */
|
||
in_arpinput(m);
|
||
return;
|
||
case ARPOP_REVREPLY:
|
||
break;
|
||
case ARPOP_REVREQUEST: /* handled by rarpd(8) */
|
||
default:
|
||
goto out;
|
||
}
|
||
if (!revarp_in_progress)
|
||
goto out;
|
||
ifp = m->m_pkthdr.rcvif;
|
||
if (ifp != myip_ifp) /* !same interface */
|
||
goto out;
|
||
if (myip_initialized)
|
||
goto wake;
|
||
if (bcmp(ar->arp_tha, ((struct arpcom *)ifp)->ac_enaddr,
|
||
sizeof(ar->arp_tha)))
|
||
goto out;
|
||
bcopy((caddr_t)ar->arp_spa, (caddr_t)&srv_ip, sizeof(srv_ip));
|
||
bcopy((caddr_t)ar->arp_tpa, (caddr_t)&myip, sizeof(myip));
|
||
myip_initialized = 1;
|
||
wake: /* Do wakeup every time in case it was missed. */
|
||
wakeup((caddr_t)&myip);
|
||
|
||
out:
|
||
m_freem(m);
|
||
}
|
||
|
||
/*
|
||
* Send a RARP request for the ip address of the specified interface.
|
||
* The request should be RFC 903-compliant.
|
||
*/
|
||
void
|
||
revarprequest(ifp)
|
||
struct ifnet *ifp;
|
||
{
|
||
struct sockaddr sa;
|
||
struct mbuf *m;
|
||
struct ether_header *eh;
|
||
struct ether_arp *ea;
|
||
struct arpcom *ac = (struct arpcom *)ifp;
|
||
|
||
if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
|
||
return;
|
||
m->m_len = sizeof(*ea);
|
||
m->m_pkthdr.len = sizeof(*ea);
|
||
MH_ALIGN(m, sizeof(*ea));
|
||
ea = mtod(m, struct ether_arp *);
|
||
eh = (struct ether_header *)sa.sa_data;
|
||
bzero((caddr_t)ea, sizeof(*ea));
|
||
bcopy((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
|
||
sizeof(eh->ether_dhost));
|
||
eh->ether_type = htons(ETHERTYPE_REVARP);
|
||
ea->arp_hrd = htons(ARPHRD_ETHER);
|
||
ea->arp_pro = htons(ETHERTYPE_IP);
|
||
ea->arp_hln = sizeof(ea->arp_sha); /* hardware address length */
|
||
ea->arp_pln = sizeof(ea->arp_spa); /* protocol address length */
|
||
ea->arp_op = htons(ARPOP_REVREQUEST);
|
||
bcopy((caddr_t)ac->ac_enaddr, (caddr_t)ea->arp_sha,
|
||
sizeof(ea->arp_sha));
|
||
bcopy((caddr_t)ac->ac_enaddr, (caddr_t)ea->arp_tha,
|
||
sizeof(ea->arp_tha));
|
||
sa.sa_family = AF_UNSPEC;
|
||
sa.sa_len = sizeof(sa);
|
||
ifp->if_output(ifp, m, &sa, (struct rtentry *)0);
|
||
}
|
||
|
||
/*
|
||
* RARP for the ip address of the specified interface, but also
|
||
* save the ip address of the server that sent the answer.
|
||
* Timeout if no response is received.
|
||
*/
|
||
int
|
||
revarpwhoarewe(ifp, serv_in, clnt_in)
|
||
struct ifnet *ifp;
|
||
struct in_addr *serv_in;
|
||
struct in_addr *clnt_in;
|
||
{
|
||
int result, count = 20;
|
||
|
||
if (myip_initialized)
|
||
return EIO;
|
||
|
||
myip_ifp = ifp;
|
||
revarp_in_progress = 1;
|
||
while (count--) {
|
||
revarprequest(ifp);
|
||
result = tsleep((caddr_t)&myip, PSOCK, "revarp", hz/2);
|
||
if (result != EWOULDBLOCK)
|
||
break;
|
||
}
|
||
revarp_in_progress = 0;
|
||
if (!myip_initialized)
|
||
return ENETUNREACH;
|
||
|
||
bcopy((caddr_t)&srv_ip, serv_in, sizeof(*serv_in));
|
||
bcopy((caddr_t)&myip, clnt_in, sizeof(*clnt_in));
|
||
return 0;
|
||
}
|
||
|
||
/* For compatibility: only saves interface address. */
|
||
int
|
||
revarpwhoami(in, ifp)
|
||
struct in_addr *in;
|
||
struct ifnet *ifp;
|
||
{
|
||
struct in_addr server;
|
||
return (revarpwhoarewe(ifp, &server, in));
|
||
}
|
||
|
||
|
||
#ifdef DDB
|
||
|
||
#include <machine/db_machdep.h>
|
||
#include <ddb/db_interface.h>
|
||
#include <ddb/db_output.h>
|
||
static void
|
||
db_print_sa(sa)
|
||
struct sockaddr *sa;
|
||
{
|
||
int len;
|
||
u_char *p;
|
||
|
||
if (sa == 0) {
|
||
db_printf("[NULL]");
|
||
return;
|
||
}
|
||
|
||
p = (u_char*)sa;
|
||
len = sa->sa_len;
|
||
db_printf("[");
|
||
while (len > 0) {
|
||
db_printf("%d", *p);
|
||
p++; len--;
|
||
if (len) db_printf(",");
|
||
}
|
||
db_printf("]\n");
|
||
}
|
||
static void
|
||
db_print_ifa(ifa)
|
||
struct ifaddr *ifa;
|
||
{
|
||
if (ifa == 0)
|
||
return;
|
||
db_printf(" ifa_addr=");
|
||
db_print_sa(ifa->ifa_addr);
|
||
db_printf(" ifa_dsta=");
|
||
db_print_sa(ifa->ifa_dstaddr);
|
||
db_printf(" ifa_mask=");
|
||
db_print_sa(ifa->ifa_netmask);
|
||
db_printf(" flags=0x%x,refcnt=%d,metric=%d\n",
|
||
ifa->ifa_flags,
|
||
ifa->ifa_refcnt,
|
||
ifa->ifa_metric);
|
||
}
|
||
static void
|
||
db_print_llinfo(li)
|
||
caddr_t li;
|
||
{
|
||
struct llinfo_arp *la;
|
||
|
||
if (li == 0)
|
||
return;
|
||
la = (struct llinfo_arp *)li;
|
||
db_printf(" la_rt=%p la_hold=%p, la_asked=0x%lx\n",
|
||
la->la_rt, la->la_hold, la->la_asked);
|
||
}
|
||
/*
|
||
* Function to pass to rn_walktree().
|
||
* Return non-zero error to abort walk.
|
||
*/
|
||
static int
|
||
db_show_radix_node(rn, w)
|
||
struct radix_node *rn;
|
||
void *w;
|
||
{
|
||
struct rtentry *rt = (struct rtentry *)rn;
|
||
|
||
db_printf("rtentry=%p", rt);
|
||
|
||
db_printf(" flags=0x%x refcnt=%d use=%ld expire=%ld\n",
|
||
rt->rt_flags, rt->rt_refcnt,
|
||
rt->rt_use, rt->rt_expire);
|
||
|
||
db_printf(" key="); db_print_sa(rt_key(rt));
|
||
db_printf(" mask="); db_print_sa(rt_mask(rt));
|
||
db_printf(" gw="); db_print_sa(rt->rt_gateway);
|
||
|
||
db_printf(" ifp=%p ", rt->rt_ifp);
|
||
if (rt->rt_ifp)
|
||
db_printf("(%s)", rt->rt_ifp->if_xname);
|
||
else
|
||
db_printf("(NULL)");
|
||
|
||
db_printf(" ifa=%p\n", rt->rt_ifa);
|
||
db_print_ifa(rt->rt_ifa);
|
||
|
||
db_printf(" genmask="); db_print_sa(rt->rt_genmask);
|
||
|
||
db_printf(" gwroute=%p llinfo=%p\n",
|
||
rt->rt_gwroute, rt->rt_llinfo);
|
||
db_print_llinfo(rt->rt_llinfo);
|
||
|
||
return (0);
|
||
}
|
||
/*
|
||
* Function to print all the route trees.
|
||
* Use this from ddb: "call db_show_arptab"
|
||
*/
|
||
int
|
||
db_show_arptab()
|
||
{
|
||
struct radix_node_head *rnh;
|
||
rnh = rt_tables[AF_INET];
|
||
db_printf("Route tree for AF_INET\n");
|
||
if (rnh == NULL) {
|
||
db_printf(" (not initialized)\n");
|
||
return (0);
|
||
}
|
||
rn_walktree(rnh, db_show_radix_node, NULL);
|
||
return (0);
|
||
}
|
||
#endif
|
||
#endif /* INET */
|