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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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* $Id: if_ether.c,v 1.2 2001-09-27 12:01:55 chris Exp $
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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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#include <sys/param.h>
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#include <sys/kernel.h>
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#include <sys/sysctl.h>
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#include <sys/queue.h>
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#include <sys/systm.h>
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#include <sys/mbuf.h>
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#include <sys/malloc.h>
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#include <sys/socket.h>
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#include <sys/syslog.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 <net/netisr.h>
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#include <netinet/in.h>
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#include <netinet/in_var.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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SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, "");
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/* timer values */
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static int arpt_prune = (5*60*1); /* walk list every 5 minutes */
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static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */
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static int arpt_down = 20; /* once declared down, don't send for 20 sec */
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SYSCTL_INT(_net_link_ether_inet, OID_AUTO, prune_intvl, CTLFLAG_RW,
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&arpt_prune, 0, "");
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SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW,
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&arpt_keep, 0, "");
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SYSCTL_INT(_net_link_ether_inet, OID_AUTO, host_down_time, CTLFLAG_RW,
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&arpt_down, 0, "");
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#define rt_expire rt_rmx.rmx_expire
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struct llinfo_arp {
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LIST_ENTRY(llinfo_arp) la_le;
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struct rtentry *la_rt;
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struct mbuf *la_hold; /* last packet until resolved/timeout */
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long la_asked; /* last time we QUERIED for this addr */
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#define la_timer la_rt->rt_rmx.rmx_expire /* deletion time in seconds */
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};
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static LIST_HEAD(, llinfo_arp) llinfo_arp;
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struct ifqueue arpintrq = {0, 0, 0, 50};
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static int arp_inuse, arp_allocated;
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static int arp_maxtries = 5;
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static int useloopback = 1; /* use loopback interface for local traffic */
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static int arp_proxyall = 0;
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SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW,
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&arp_maxtries, 0, "");
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SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW,
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&useloopback, 0, "");
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SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW,
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&arp_proxyall, 0, "");
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static void arp_rtrequest __P((int, struct rtentry *, struct sockaddr *));
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static void arprequest __P((struct arpcom *, u_long *, u_long *, u_char *));
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void arpintr __P((void));
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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
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*arplookup __P((u_long, int, int));
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static void in_arpinput __P((struct mbuf *));
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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(ignored_arg)
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void *ignored_arg;
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{
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int s = splnet();
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register struct llinfo_arp *la = llinfo_arp.lh_first;
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struct llinfo_arp *ola;
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timeout(arptimer, (caddr_t)0, arpt_prune * hz);
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while ((ola = la) != 0) {
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register struct rtentry *rt = la->la_rt;
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la = la->la_le.le_next;
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if (rt->rt_expire && rt->rt_expire <= rtems_bsdnet_seconds_since_boot())
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arptfree(ola); /* 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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static 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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static int arpinit_done;
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if (!arpinit_done) {
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arpinit_done = 1;
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LIST_INIT(&llinfo_arp);
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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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rt->rt_expire = rtems_bsdnet_seconds_since_boot();
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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\n");
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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_le);
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/*
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* This keeps the multicast addresses from showing up
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* in `arp -a' listings as unresolved. It's not actually
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* functional. Then the same for broadcast.
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*/
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if (IN_MULTICAST(ntohl(SIN(rt_key(rt))->sin_addr.s_addr))) {
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ETHER_MAP_IP_MULTICAST(&SIN(rt_key(rt))->sin_addr,
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LLADDR(SDL(gate)));
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SDL(gate)->sdl_alen = 6;
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rt->rt_expire = 0;
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}
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if (in_broadcast(SIN(rt_key(rt))->sin_addr, rt->rt_ifp)) {
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memcpy(LLADDR(SDL(gate)), etherbroadcastaddr, 6);
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SDL(gate)->sdl_alen = 6;
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rt->rt_expire = 0;
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}
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229 |
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230 |
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if (SIN(rt_key(rt))->sin_addr.s_addr ==
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231 |
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(IA_SIN(rt->rt_ifa))->sin_addr.s_addr) {
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232 |
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/*
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233 |
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* This test used to be
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234 |
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* if (loif.if_flags & IFF_UP)
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235 |
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* It allowed local traffic to be forced
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236 |
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* through the hardware by configuring the loopback down.
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* However, it causes problems during network configuration
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238 |
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* for boards that can't receive packets they send.
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* It is now necessary to clear "useloopback" and remove
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240 |
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* the route to force traffic out to the hardware.
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241 |
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*/
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242 |
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rt->rt_expire = 0;
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243 |
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Bcopy(((struct arpcom *)rt->rt_ifp)->ac_enaddr,
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LLADDR(SDL(gate)), SDL(gate)->sdl_alen = 6);
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if (useloopback)
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rt->rt_ifp = loif;
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247 |
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|
248 |
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}
|
249 |
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break;
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250 |
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251 |
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case RTM_DELETE:
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252 |
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if (la == 0)
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253 |
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break;
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254 |
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arp_inuse--;
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255 |
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LIST_REMOVE(la, la_le);
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256 |
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rt->rt_llinfo = 0;
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257 |
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rt->rt_flags &= ~RTF_LLINFO;
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258 |
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if (la->la_hold)
|
259 |
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m_freem(la->la_hold);
|
260 |
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Free((caddr_t)la);
|
261 |
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}
|
262 |
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}
|
263 |
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|
264 |
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/*
|
265 |
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* Broadcast an ARP request. Caller specifies:
|
266 |
|
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* - arp header source ip address
|
267 |
|
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* - arp header target ip address
|
268 |
|
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* - arp header source ethernet address
|
269 |
|
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*/
|
270 |
|
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static void
|
271 |
|
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arprequest(ac, sip, tip, enaddr)
|
272 |
|
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register struct arpcom *ac;
|
273 |
|
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register u_long *sip, *tip;
|
274 |
|
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register u_char *enaddr;
|
275 |
|
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{
|
276 |
|
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register struct mbuf *m;
|
277 |
|
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register struct ether_header *eh;
|
278 |
|
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register struct ether_arp *ea;
|
279 |
|
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struct sockaddr sa;
|
280 |
|
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|
281 |
|
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if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
|
282 |
|
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return;
|
283 |
|
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m->m_len = sizeof(*ea);
|
284 |
|
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m->m_pkthdr.len = sizeof(*ea);
|
285 |
|
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MH_ALIGN(m, sizeof(*ea));
|
286 |
|
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ea = mtod(m, struct ether_arp *);
|
287 |
|
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eh = (struct ether_header *)sa.sa_data;
|
288 |
|
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bzero((caddr_t)ea, sizeof (*ea));
|
289 |
|
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(void)memcpy(eh->ether_dhost, etherbroadcastaddr, sizeof(eh->ether_dhost));
|
290 |
|
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eh->ether_type = htons(ETHERTYPE_ARP); /* if_output will not swap */
|
291 |
|
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ea->arp_hrd = htons(ARPHRD_ETHER);
|
292 |
|
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ea->arp_pro = htons(ETHERTYPE_IP);
|
293 |
|
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ea->arp_hln = sizeof(ea->arp_sha); /* hardware address length */
|
294 |
|
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ea->arp_pln = sizeof(ea->arp_spa); /* protocol address length */
|
295 |
|
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ea->arp_op = htons(ARPOP_REQUEST);
|
296 |
|
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(void)memcpy(ea->arp_sha, enaddr, sizeof(ea->arp_sha));
|
297 |
|
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(void)memcpy(ea->arp_spa, sip, sizeof(ea->arp_spa));
|
298 |
|
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(void)memcpy(ea->arp_tpa, tip, sizeof(ea->arp_tpa));
|
299 |
|
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sa.sa_family = AF_UNSPEC;
|
300 |
|
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sa.sa_len = sizeof(sa);
|
301 |
|
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(*ac->ac_if.if_output)(&ac->ac_if, m, &sa, (struct rtentry *)0);
|
302 |
|
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}
|
303 |
|
|
|
304 |
|
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/*
|
305 |
|
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* Resolve an IP address into an ethernet address. If success,
|
306 |
|
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* desten is filled in. If there is no entry in arptab,
|
307 |
|
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* set one up and broadcast a request for the IP address.
|
308 |
|
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* Hold onto this mbuf and resend it once the address
|
309 |
|
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* is finally resolved. A return value of 1 indicates
|
310 |
|
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* that desten has been filled in and the packet should be sent
|
311 |
|
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* normally; a 0 return indicates that the packet has been
|
312 |
|
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* taken over here, either now or for later transmission.
|
313 |
|
|
*/
|
314 |
|
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int
|
315 |
|
|
arpresolve(ac, rt, m, dst, desten, rt0)
|
316 |
|
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register struct arpcom *ac;
|
317 |
|
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register struct rtentry *rt;
|
318 |
|
|
struct mbuf *m;
|
319 |
|
|
register struct sockaddr *dst;
|
320 |
|
|
register u_char *desten;
|
321 |
|
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struct rtentry *rt0;
|
322 |
|
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{
|
323 |
|
|
register struct llinfo_arp *la;
|
324 |
|
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struct sockaddr_dl *sdl;
|
325 |
|
|
|
326 |
|
|
if (m->m_flags & M_BCAST) { /* broadcast */
|
327 |
|
|
(void)memcpy(desten, etherbroadcastaddr, sizeof(etherbroadcastaddr));
|
328 |
|
|
return (1);
|
329 |
|
|
}
|
330 |
|
|
if (m->m_flags & M_MCAST) { /* multicast */
|
331 |
|
|
ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten);
|
332 |
|
|
return(1);
|
333 |
|
|
}
|
334 |
|
|
if (rt)
|
335 |
|
|
la = (struct llinfo_arp *)rt->rt_llinfo;
|
336 |
|
|
else {
|
337 |
|
|
la = arplookup(SIN(dst)->sin_addr.s_addr, 1, 0);
|
338 |
|
|
if (la)
|
339 |
|
|
rt = la->la_rt;
|
340 |
|
|
}
|
341 |
|
|
if (la == 0 || rt == 0) {
|
342 |
|
|
log(LOG_DEBUG, "arpresolve: can't allocate llinfo for %s\n",
|
343 |
|
|
inet_ntoa(SIN(dst)->sin_addr));
|
344 |
|
|
m_freem(m);
|
345 |
|
|
return (0);
|
346 |
|
|
}
|
347 |
|
|
sdl = SDL(rt->rt_gateway);
|
348 |
|
|
/*
|
349 |
|
|
* Check the address family and length is valid, the address
|
350 |
|
|
* is resolved; otherwise, try to resolve.
|
351 |
|
|
*/
|
352 |
|
|
if ((rt->rt_expire == 0 || rt->rt_expire > rtems_bsdnet_seconds_since_boot()) &&
|
353 |
|
|
sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) {
|
354 |
|
|
bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
|
355 |
|
|
return 1;
|
356 |
|
|
}
|
357 |
|
|
/*
|
358 |
|
|
* There is an arptab entry, but no ethernet address
|
359 |
|
|
* response yet. Replace the held mbuf with this
|
360 |
|
|
* latest one.
|
361 |
|
|
*/
|
362 |
|
|
if (la->la_hold)
|
363 |
|
|
m_freem(la->la_hold);
|
364 |
|
|
la->la_hold = m;
|
365 |
|
|
if (rt->rt_expire) {
|
366 |
|
|
rt->rt_flags &= ~RTF_REJECT;
|
367 |
|
|
if (la->la_asked == 0 || rt->rt_expire != rtems_bsdnet_seconds_since_boot()) {
|
368 |
|
|
rt->rt_expire = rtems_bsdnet_seconds_since_boot();
|
369 |
|
|
if (la->la_asked++ < arp_maxtries)
|
370 |
|
|
arprequest(ac,
|
371 |
|
|
&(SIN(rt->rt_ifa->ifa_addr)->sin_addr.s_addr),
|
372 |
|
|
&(SIN(dst)->sin_addr.s_addr),
|
373 |
|
|
ac->ac_enaddr);
|
374 |
|
|
else {
|
375 |
|
|
rt->rt_flags |= RTF_REJECT;
|
376 |
|
|
rt->rt_expire += arpt_down;
|
377 |
|
|
la->la_asked = 0;
|
378 |
|
|
}
|
379 |
|
|
|
380 |
|
|
}
|
381 |
|
|
}
|
382 |
|
|
return (0);
|
383 |
|
|
}
|
384 |
|
|
|
385 |
|
|
/*
|
386 |
|
|
* Common length and type checks are done here,
|
387 |
|
|
* then the protocol-specific routine is called.
|
388 |
|
|
*/
|
389 |
|
|
void
|
390 |
|
|
arpintr(void)
|
391 |
|
|
{
|
392 |
|
|
register struct mbuf *m;
|
393 |
|
|
register struct arphdr *ar;
|
394 |
|
|
int s;
|
395 |
|
|
|
396 |
|
|
while (arpintrq.ifq_head) {
|
397 |
|
|
s = splimp();
|
398 |
|
|
IF_DEQUEUE(&arpintrq, m);
|
399 |
|
|
splx(s);
|
400 |
|
|
if (m == 0 || (m->m_flags & M_PKTHDR) == 0)
|
401 |
|
|
panic("arpintr");
|
402 |
|
|
if (m->m_len >= sizeof(struct arphdr) &&
|
403 |
|
|
(ar = mtod(m, struct arphdr *)) &&
|
404 |
|
|
ntohs(ar->ar_hrd) == ARPHRD_ETHER &&
|
405 |
|
|
m->m_len >=
|
406 |
|
|
sizeof(struct arphdr) + 2 * ar->ar_hln + 2 * ar->ar_pln)
|
407 |
|
|
|
408 |
|
|
switch (ntohs(ar->ar_pro)) {
|
409 |
|
|
|
410 |
|
|
case ETHERTYPE_IP:
|
411 |
|
|
in_arpinput(m);
|
412 |
|
|
continue;
|
413 |
|
|
}
|
414 |
|
|
m_freem(m);
|
415 |
|
|
}
|
416 |
|
|
}
|
417 |
|
|
|
418 |
|
|
NETISR_SET(NETISR_ARP, arpintr);
|
419 |
|
|
|
420 |
|
|
/*
|
421 |
|
|
* ARP for Internet protocols on 10 Mb/s Ethernet.
|
422 |
|
|
* Algorithm is that given in RFC 826.
|
423 |
|
|
* In addition, a sanity check is performed on the sender
|
424 |
|
|
* protocol address, to catch impersonators.
|
425 |
|
|
* We no longer handle negotiations for use of trailer protocol:
|
426 |
|
|
* Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent
|
427 |
|
|
* along with IP replies if we wanted trailers sent to us,
|
428 |
|
|
* and also sent them in response to IP replies.
|
429 |
|
|
* This allowed either end to announce the desire to receive
|
430 |
|
|
* trailer packets.
|
431 |
|
|
* We no longer reply to requests for ETHERTYPE_TRAIL protocol either,
|
432 |
|
|
* but formerly didn't normally send requests.
|
433 |
|
|
*/
|
434 |
|
|
static void
|
435 |
|
|
in_arpinput(m)
|
436 |
|
|
struct mbuf *m;
|
437 |
|
|
{
|
438 |
|
|
register struct ether_arp *ea;
|
439 |
|
|
register struct arpcom *ac = (struct arpcom *)m->m_pkthdr.rcvif;
|
440 |
|
|
struct ether_header *eh;
|
441 |
|
|
register struct llinfo_arp *la = 0;
|
442 |
|
|
register struct rtentry *rt;
|
443 |
|
|
struct in_ifaddr *ia, *maybe_ia = 0;
|
444 |
|
|
struct sockaddr_dl *sdl;
|
445 |
|
|
struct sockaddr sa;
|
446 |
|
|
struct in_addr isaddr, itaddr, myaddr;
|
447 |
|
|
int op;
|
448 |
|
|
|
449 |
|
|
ea = mtod(m, struct ether_arp *);
|
450 |
|
|
op = ntohs(ea->arp_op);
|
451 |
|
|
(void)memcpy(&isaddr, ea->arp_spa, sizeof (isaddr));
|
452 |
|
|
(void)memcpy(&itaddr, ea->arp_tpa, sizeof (itaddr));
|
453 |
|
|
for (ia = in_ifaddr; ia; ia = ia->ia_next)
|
454 |
|
|
if (ia->ia_ifp == &ac->ac_if) {
|
455 |
|
|
maybe_ia = ia;
|
456 |
|
|
if ((itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) ||
|
457 |
|
|
(isaddr.s_addr == ia->ia_addr.sin_addr.s_addr))
|
458 |
|
|
break;
|
459 |
|
|
}
|
460 |
|
|
if (maybe_ia == 0) {
|
461 |
|
|
m_freem(m);
|
462 |
|
|
return;
|
463 |
|
|
}
|
464 |
|
|
myaddr = ia ? ia->ia_addr.sin_addr : maybe_ia->ia_addr.sin_addr;
|
465 |
|
|
if (!bcmp((caddr_t)ea->arp_sha, (caddr_t)ac->ac_enaddr,
|
466 |
|
|
sizeof (ea->arp_sha))) {
|
467 |
|
|
m_freem(m); /* it's from me, ignore it. */
|
468 |
|
|
return;
|
469 |
|
|
}
|
470 |
|
|
if (!bcmp((caddr_t)ea->arp_sha, (caddr_t)etherbroadcastaddr,
|
471 |
|
|
sizeof (ea->arp_sha))) {
|
472 |
|
|
log(LOG_ERR,
|
473 |
|
|
"arp: ether address is broadcast for IP address %s!\n",
|
474 |
|
|
inet_ntoa(isaddr));
|
475 |
|
|
m_freem(m);
|
476 |
|
|
return;
|
477 |
|
|
}
|
478 |
|
|
if (isaddr.s_addr == myaddr.s_addr) {
|
479 |
|
|
log(LOG_ERR,
|
480 |
|
|
"arp: %6D is using my IP address %s!\n",
|
481 |
|
|
ea->arp_sha, ":", inet_ntoa(isaddr));
|
482 |
|
|
itaddr = myaddr;
|
483 |
|
|
goto reply;
|
484 |
|
|
}
|
485 |
|
|
la = arplookup(isaddr.s_addr, itaddr.s_addr == myaddr.s_addr, 0);
|
486 |
|
|
if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) {
|
487 |
|
|
if (sdl->sdl_alen &&
|
488 |
|
|
bcmp((caddr_t)ea->arp_sha, LLADDR(sdl), sdl->sdl_alen))
|
489 |
|
|
log(LOG_INFO, "arp: %s moved from %6D to %6D\n",
|
490 |
|
|
inet_ntoa(isaddr), (u_char *)LLADDR(sdl), ":",
|
491 |
|
|
ea->arp_sha, ":");
|
492 |
|
|
(void)memcpy(LLADDR(sdl), ea->arp_sha, sizeof(ea->arp_sha));
|
493 |
|
|
sdl->sdl_alen = sizeof(ea->arp_sha);
|
494 |
|
|
if (rt->rt_expire)
|
495 |
|
|
rt->rt_expire = rtems_bsdnet_seconds_since_boot() + arpt_keep;
|
496 |
|
|
rt->rt_flags &= ~RTF_REJECT;
|
497 |
|
|
la->la_asked = 0;
|
498 |
|
|
if (la->la_hold) {
|
499 |
|
|
(*ac->ac_if.if_output)(&ac->ac_if, la->la_hold,
|
500 |
|
|
rt_key(rt), rt);
|
501 |
|
|
la->la_hold = 0;
|
502 |
|
|
}
|
503 |
|
|
}
|
504 |
|
|
reply:
|
505 |
|
|
if (op != ARPOP_REQUEST) {
|
506 |
|
|
m_freem(m);
|
507 |
|
|
return;
|
508 |
|
|
}
|
509 |
|
|
if (itaddr.s_addr == myaddr.s_addr) {
|
510 |
|
|
/* I am the target */
|
511 |
|
|
(void)memcpy(ea->arp_tha, ea->arp_sha, sizeof(ea->arp_sha));
|
512 |
|
|
(void)memcpy(ea->arp_sha, ac->ac_enaddr, sizeof(ea->arp_sha));
|
513 |
|
|
} else {
|
514 |
|
|
la = arplookup(itaddr.s_addr, 0, SIN_PROXY);
|
515 |
|
|
if (la == NULL) {
|
516 |
|
|
struct sockaddr_in sin;
|
517 |
|
|
|
518 |
|
|
if (!arp_proxyall) {
|
519 |
|
|
m_freem(m);
|
520 |
|
|
return;
|
521 |
|
|
}
|
522 |
|
|
|
523 |
|
|
bzero(&sin, sizeof sin);
|
524 |
|
|
sin.sin_family = AF_INET;
|
525 |
|
|
sin.sin_len = sizeof sin;
|
526 |
|
|
sin.sin_addr = itaddr;
|
527 |
|
|
|
528 |
|
|
rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL);
|
529 |
|
|
if (!rt) {
|
530 |
|
|
m_freem(m);
|
531 |
|
|
return;
|
532 |
|
|
}
|
533 |
|
|
/*
|
534 |
|
|
* Don't send proxies for nodes on the same interface
|
535 |
|
|
* as this one came out of, or we'll get into a fight
|
536 |
|
|
* over who claims what Ether address.
|
537 |
|
|
*/
|
538 |
|
|
if (rt->rt_ifp == &ac->ac_if) {
|
539 |
|
|
rtfree(rt);
|
540 |
|
|
m_freem(m);
|
541 |
|
|
return;
|
542 |
|
|
}
|
543 |
|
|
(void)memcpy(ea->arp_tha, ea->arp_sha, sizeof(ea->arp_sha));
|
544 |
|
|
(void)memcpy(ea->arp_sha, ac->ac_enaddr, sizeof(ea->arp_sha));
|
545 |
|
|
rtfree(rt);
|
546 |
|
|
#ifdef DEBUG_PROXY
|
547 |
|
|
printf("arp: proxying for %s\n",
|
548 |
|
|
inet_ntoa(itaddr));
|
549 |
|
|
#endif
|
550 |
|
|
} else {
|
551 |
|
|
rt = la->la_rt;
|
552 |
|
|
(void)memcpy(ea->arp_tha, ea->arp_sha, sizeof(ea->arp_sha));
|
553 |
|
|
sdl = SDL(rt->rt_gateway);
|
554 |
|
|
(void)memcpy(ea->arp_sha, LLADDR(sdl), sizeof(ea->arp_sha));
|
555 |
|
|
}
|
556 |
|
|
}
|
557 |
|
|
|
558 |
|
|
(void)memcpy(ea->arp_tpa, ea->arp_spa, sizeof(ea->arp_spa));
|
559 |
|
|
(void)memcpy(ea->arp_spa, &itaddr, sizeof(ea->arp_spa));
|
560 |
|
|
ea->arp_op = htons(ARPOP_REPLY);
|
561 |
|
|
ea->arp_pro = htons(ETHERTYPE_IP); /* let's be sure! */
|
562 |
|
|
eh = (struct ether_header *)sa.sa_data;
|
563 |
|
|
(void)memcpy(eh->ether_dhost, ea->arp_tha, sizeof(eh->ether_dhost));
|
564 |
|
|
eh->ether_type = htons(ETHERTYPE_ARP);
|
565 |
|
|
sa.sa_family = AF_UNSPEC;
|
566 |
|
|
sa.sa_len = sizeof(sa);
|
567 |
|
|
(*ac->ac_if.if_output)(&ac->ac_if, m, &sa, (struct rtentry *)0);
|
568 |
|
|
return;
|
569 |
|
|
}
|
570 |
|
|
|
571 |
|
|
/*
|
572 |
|
|
* Free an arp entry.
|
573 |
|
|
*/
|
574 |
|
|
static void
|
575 |
|
|
arptfree(la)
|
576 |
|
|
register struct llinfo_arp *la;
|
577 |
|
|
{
|
578 |
|
|
register struct rtentry *rt = la->la_rt;
|
579 |
|
|
register struct sockaddr_dl *sdl;
|
580 |
|
|
if (rt == 0)
|
581 |
|
|
panic("arptfree");
|
582 |
|
|
if (rt->rt_refcnt > 0 && (sdl = SDL(rt->rt_gateway)) &&
|
583 |
|
|
sdl->sdl_family == AF_LINK) {
|
584 |
|
|
sdl->sdl_alen = 0;
|
585 |
|
|
la->la_asked = 0;
|
586 |
|
|
rt->rt_flags &= ~RTF_REJECT;
|
587 |
|
|
return;
|
588 |
|
|
}
|
589 |
|
|
rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, rt_mask(rt),
|
590 |
|
|
0, (struct rtentry **)0);
|
591 |
|
|
}
|
592 |
|
|
/*
|
593 |
|
|
* Lookup or enter a new address in arptab.
|
594 |
|
|
*/
|
595 |
|
|
static struct llinfo_arp *
|
596 |
|
|
arplookup(addr, create, proxy)
|
597 |
|
|
u_long addr;
|
598 |
|
|
int create, proxy;
|
599 |
|
|
{
|
600 |
|
|
register struct rtentry *rt;
|
601 |
|
|
static struct sockaddr_inarp sin = {sizeof(sin), AF_INET };
|
602 |
|
|
const char *why = 0;
|
603 |
|
|
|
604 |
|
|
sin.sin_addr.s_addr = addr;
|
605 |
|
|
sin.sin_other = proxy ? SIN_PROXY : 0;
|
606 |
|
|
rt = rtalloc1((struct sockaddr *)&sin, create, 0UL);
|
607 |
|
|
if (rt == 0)
|
608 |
|
|
return (0);
|
609 |
|
|
rt->rt_refcnt--;
|
610 |
|
|
|
611 |
|
|
if (rt->rt_flags & RTF_GATEWAY)
|
612 |
|
|
why = "host is not on local network";
|
613 |
|
|
else if ((rt->rt_flags & RTF_LLINFO) == 0)
|
614 |
|
|
why = "could not allocate llinfo";
|
615 |
|
|
else if (rt->rt_gateway->sa_family != AF_LINK)
|
616 |
|
|
why = "gateway route is not ours";
|
617 |
|
|
|
618 |
|
|
if (why && create) {
|
619 |
|
|
log(LOG_DEBUG, "arplookup %s failed: %s\n",
|
620 |
|
|
inet_ntoa(sin.sin_addr), why);
|
621 |
|
|
return 0;
|
622 |
|
|
} else if (why) {
|
623 |
|
|
return 0;
|
624 |
|
|
}
|
625 |
|
|
return ((struct llinfo_arp *)rt->rt_llinfo);
|
626 |
|
|
}
|
627 |
|
|
|
628 |
|
|
void
|
629 |
|
|
arp_ifinit(ac, ifa)
|
630 |
|
|
struct arpcom *ac;
|
631 |
|
|
struct ifaddr *ifa;
|
632 |
|
|
{
|
633 |
|
|
if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY)
|
634 |
|
|
arprequest(ac, &(IA_SIN(ifa)->sin_addr.s_addr),
|
635 |
|
|
&(IA_SIN(ifa)->sin_addr.s_addr), ac->ac_enaddr);
|
636 |
|
|
ifa->ifa_rtrequest = arp_rtrequest;
|
637 |
|
|
ifa->ifa_flags |= RTF_CLONING;
|
638 |
|
|
}
|