f0f3379ed5
to are about to expire. This prevents high packet rate flows from experiencing packet drops at the sender following ARP cache entry timeout. PR: kern/25517 Reviewed by: luigi MFC after: 7 days
949 lines
26 KiB
C
949 lines
26 KiB
C
/*
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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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* $FreeBSD$
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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 "opt_inet.h"
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#include "opt_bdg.h"
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#include <sys/param.h>
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#include <sys/kernel.h>
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#include <sys/queue.h>
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#include <sys/sysctl.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/if_types.h>
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#include <net/route.h>
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#include <net/netisr.h>
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#include <net/if_llc.h>
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#ifdef BRIDGE
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#include <net/ethernet.h>
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#include <net/bridge.h>
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#endif
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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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#include <net/if_arc.h>
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#include <net/iso88025.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_DECL(_net_link_ether);
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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;
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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_init(void);
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static void arp_rtrequest(int, struct rtentry *, struct rt_addrinfo *);
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static void arprequest(struct ifnet *,
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struct in_addr *, struct in_addr *, u_char *);
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static void arpintr(void);
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static void arptfree(struct llinfo_arp *);
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static void arptimer(void *);
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static struct llinfo_arp
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*arplookup(u_long, int, int);
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#ifdef INET
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static void in_arpinput(struct mbuf *);
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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(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 = LIST_FIRST(&llinfo_arp);
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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 = LIST_NEXT(la, la_le);
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if (rt->rt_expire && rt->rt_expire <= time_second)
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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, info)
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int req;
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register struct rtentry *rt;
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struct rt_addrinfo *info;
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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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register_netisr(NETISR_ARP, arpintr);
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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 = time_second;
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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(rt->rt_ifp,
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&SIN(rt_key(rt))->sin_addr,
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&SIN(rt_key(rt))->sin_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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#ifdef INET
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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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rt->rt_ifp->if_type != IFT_ARCNET) {
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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)), rt->rt_ifp->if_broadcastaddr,
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rt->rt_ifp->if_addrlen);
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SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen;
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rt->rt_expire = 0;
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}
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#endif
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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
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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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* 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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* the route to force traffic out to the hardware.
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*/
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rt->rt_expire = 0;
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Bcopy(IF_LLADDR(rt->rt_ifp), LLADDR(SDL(gate)),
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SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen);
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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_le);
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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(ifp, sip, tip, enaddr)
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register struct ifnet *ifp;
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register struct in_addr *sip, *tip;
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register u_char *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 arc_header *arh;
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register struct arphdr *ah;
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struct sockaddr sa;
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static u_char llcx[] = { 0x82, 0x40, LLC_SNAP_LSAP, LLC_SNAP_LSAP,
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LLC_UI, 0x00, 0x00, 0x00, 0x08, 0x06 };
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u_short ar_hrd;
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if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
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return;
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m->m_pkthdr.rcvif = (struct ifnet *)0;
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switch (ifp->if_type) {
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case IFT_ARCNET:
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ar_hrd = htons(ARPHRD_ARCNET);
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m->m_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
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m->m_pkthdr.len = m->m_len;
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MH_ALIGN(m, m->m_len);
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arh = (struct arc_header *)sa.sa_data;
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arh->arc_dhost = *ifp->if_broadcastaddr;
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arh->arc_type = ARCTYPE_ARP;
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ah = mtod(m, struct arphdr *);
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break;
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case IFT_ISO88025:
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ar_hrd = htons(ARPHRD_IEEE802);
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m->m_len = sizeof(llcx) +
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arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
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m->m_pkthdr.len = m->m_len;
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MH_ALIGN(m, m->m_len);
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(void)memcpy(mtod(m, caddr_t), llcx, sizeof(llcx));
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(void)memcpy(sa.sa_data, ifp->if_broadcastaddr, 6);
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(void)memcpy(sa.sa_data + 6, enaddr, 6);
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sa.sa_data[6] |= TR_RII;
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sa.sa_data[12] = TR_AC;
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sa.sa_data[13] = TR_LLC_FRAME;
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ah = (struct arphdr *)(mtod(m, char *) + sizeof(llcx));
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break;
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case IFT_FDDI:
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case IFT_ETHER:
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/*
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* This may not be correct for types not explicitly
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* listed, but this is our best guess
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*/
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default:
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ar_hrd = htons(ARPHRD_ETHER);
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m->m_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
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m->m_pkthdr.len = m->m_len;
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MH_ALIGN(m, m->m_len);
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eh = (struct ether_header *)sa.sa_data;
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/* if_output will not swap */
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eh->ether_type = htons(ETHERTYPE_ARP);
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(void)memcpy(eh->ether_dhost, ifp->if_broadcastaddr,
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sizeof(eh->ether_dhost));
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|
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ah = mtod(m, struct arphdr *);
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break;
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}
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|
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ah->ar_hrd = ar_hrd;
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ah->ar_pro = htons(ETHERTYPE_IP);
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ah->ar_hln = ifp->if_addrlen; /* hardware address length */
|
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ah->ar_pln = sizeof(struct in_addr); /* protocol address length */
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ah->ar_op = htons(ARPOP_REQUEST);
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(void)memcpy(ar_sha(ah), enaddr, ah->ar_hln);
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(void)memcpy(ar_spa(ah), sip, ah->ar_pln);
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(void)memcpy(ar_tpa(ah), tip, ah->ar_pln);
|
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|
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sa.sa_family = AF_UNSPEC;
|
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sa.sa_len = sizeof(sa);
|
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(*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0);
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}
|
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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.
|
|
* Hold onto this mbuf and resend it once the address
|
|
* is finally resolved. A return value of 1 indicates
|
|
* that desten has been filled in and the packet should be sent
|
|
* 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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int
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arpresolve(ifp, rt, m, dst, desten, rt0)
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register struct ifnet *ifp;
|
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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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struct rtentry *rt0;
|
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{
|
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struct llinfo_arp *la = 0;
|
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struct sockaddr_dl *sdl;
|
|
|
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if (m->m_flags & M_BCAST) { /* broadcast */
|
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(void)memcpy(desten, ifp->if_broadcastaddr, ifp->if_addrlen);
|
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return (1);
|
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}
|
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if (m->m_flags & M_MCAST && ifp->if_type != IFT_ARCNET) {/* multicast */
|
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ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten);
|
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return(1);
|
|
}
|
|
if (rt)
|
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la = (struct llinfo_arp *)rt->rt_llinfo;
|
|
if (la == 0) {
|
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la = arplookup(SIN(dst)->sin_addr.s_addr, 1, 0);
|
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if (la)
|
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rt = la->la_rt;
|
|
}
|
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if (la == 0 || rt == 0) {
|
|
log(LOG_DEBUG, "arpresolve: can't allocate llinfo for %s%s%s\n",
|
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inet_ntoa(SIN(dst)->sin_addr), la ? "la" : "",
|
|
rt ? "rt" : "");
|
|
m_freem(m);
|
|
return (0);
|
|
}
|
|
sdl = SDL(rt->rt_gateway);
|
|
/*
|
|
* Check the address family and length is valid, the address
|
|
* is resolved; otherwise, try to resolve.
|
|
*/
|
|
if ((rt->rt_expire == 0 || rt->rt_expire > time_second) &&
|
|
sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) {
|
|
/*
|
|
* If entry has an expiry time and it is approaching,
|
|
* see if we need to send an ARP request within this
|
|
* arpt_down interval.
|
|
*/
|
|
if ((rt->rt_expire != 0) &&
|
|
(time_second + (arp_maxtries - la->la_asked) * arpt_down >
|
|
rt->rt_expire)) {
|
|
arprequest(ifp,
|
|
&SIN(rt->rt_ifa->ifa_addr)->sin_addr,
|
|
&SIN(dst)->sin_addr,
|
|
IF_LLADDR(ifp));
|
|
la->la_asked++;
|
|
}
|
|
|
|
bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
|
|
return 1;
|
|
}
|
|
/*
|
|
* If ARP is disabled on this interface, stop.
|
|
* XXX
|
|
* Probably should not allocate empty llinfo struct if we are
|
|
* not going to be sending out an arp request.
|
|
*/
|
|
if (ifp->if_flags & IFF_NOARP) {
|
|
m_freem(m);
|
|
return (0);
|
|
}
|
|
/*
|
|
* There is an arptab entry, but no ethernet address
|
|
* response yet. Replace the held mbuf with this
|
|
* latest one.
|
|
*/
|
|
if (la->la_hold)
|
|
m_freem(la->la_hold);
|
|
la->la_hold = m;
|
|
if (rt->rt_expire) {
|
|
rt->rt_flags &= ~RTF_REJECT;
|
|
if (la->la_asked == 0 || rt->rt_expire != time_second) {
|
|
rt->rt_expire = time_second;
|
|
if (la->la_asked++ < arp_maxtries)
|
|
arprequest(ifp,
|
|
&SIN(rt->rt_ifa->ifa_addr)->sin_addr,
|
|
&SIN(dst)->sin_addr,
|
|
IF_LLADDR(ifp));
|
|
else {
|
|
rt->rt_flags |= RTF_REJECT;
|
|
rt->rt_expire += arpt_down;
|
|
la->la_asked = 0;
|
|
}
|
|
|
|
}
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Common length and type checks are done here,
|
|
* then the protocol-specific routine is called.
|
|
*/
|
|
static void
|
|
arpintr()
|
|
{
|
|
register struct mbuf *m;
|
|
register struct arphdr *ar;
|
|
int s;
|
|
|
|
while (arpintrq.ifq_head) {
|
|
s = splimp();
|
|
IF_DEQUEUE(&arpintrq, m);
|
|
splx(s);
|
|
if (m == 0 || (m->m_flags & M_PKTHDR) == 0)
|
|
panic("arpintr");
|
|
|
|
if (m->m_len < sizeof(struct arphdr) &&
|
|
((m = m_pullup(m, sizeof(struct arphdr))) == NULL)) {
|
|
log(LOG_ERR, "arp: runt packet -- m_pullup failed\n");
|
|
continue;
|
|
}
|
|
ar = mtod(m, struct arphdr *);
|
|
|
|
if (ntohs(ar->ar_hrd) != ARPHRD_ETHER
|
|
&& ntohs(ar->ar_hrd) != ARPHRD_IEEE802
|
|
&& ntohs(ar->ar_hrd) != ARPHRD_ARCNET) {
|
|
log(LOG_ERR,
|
|
"arp: unknown hardware address format (0x%2D)\n",
|
|
(unsigned char *)&ar->ar_hrd, "");
|
|
m_freem(m);
|
|
continue;
|
|
}
|
|
|
|
if (m->m_pkthdr.len < arphdr_len(ar) &&
|
|
(m = m_pullup(m, arphdr_len(ar))) == NULL) {
|
|
log(LOG_ERR, "arp: runt packet\n");
|
|
m_freem(m);
|
|
continue;
|
|
}
|
|
|
|
switch (ntohs(ar->ar_pro)) {
|
|
#ifdef INET
|
|
case ETHERTYPE_IP:
|
|
in_arpinput(m);
|
|
continue;
|
|
#endif
|
|
}
|
|
m_freem(m);
|
|
}
|
|
}
|
|
|
|
#ifdef INET
|
|
/*
|
|
* ARP for Internet protocols on 10 Mb/s Ethernet.
|
|
* Algorithm is that given in RFC 826.
|
|
* In addition, a sanity check is performed on the sender
|
|
* protocol address, to catch impersonators.
|
|
* We no longer handle negotiations for use of trailer protocol:
|
|
* Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent
|
|
* along with IP replies if we wanted trailers sent to us,
|
|
* and also sent them in response to IP replies.
|
|
* This allowed either end to announce the desire to receive
|
|
* trailer packets.
|
|
* We no longer reply to requests for ETHERTYPE_TRAIL protocol either,
|
|
* but formerly didn't normally send requests.
|
|
*/
|
|
static int log_arp_wrong_iface = 1;
|
|
static int log_arp_movements = 1;
|
|
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW,
|
|
&log_arp_wrong_iface, 0,
|
|
"log arp packets arriving on the wrong interface");
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_movements, CTLFLAG_RW,
|
|
&log_arp_movements, 0,
|
|
"log arp replies from MACs different than the one in the cache");
|
|
|
|
|
|
static void
|
|
in_arpinput(m)
|
|
struct mbuf *m;
|
|
{
|
|
register struct arphdr *ah;
|
|
register struct ifnet *ifp = m->m_pkthdr.rcvif;
|
|
struct ether_header *eh;
|
|
struct arc_header *arh;
|
|
struct iso88025_header *th = (struct iso88025_header *)0;
|
|
register struct llinfo_arp *la = 0;
|
|
register struct rtentry *rt;
|
|
struct ifaddr *ifa;
|
|
struct in_ifaddr *ia;
|
|
struct sockaddr_dl *sdl;
|
|
struct sockaddr sa;
|
|
struct in_addr isaddr, itaddr, myaddr;
|
|
int op, rif_len;
|
|
int req_len;
|
|
|
|
req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
|
|
if (m->m_len < req_len && (m = m_pullup(m, req_len)) == NULL) {
|
|
log(LOG_ERR, "in_arp: runt packet -- m_pullup failed\n");
|
|
return;
|
|
}
|
|
|
|
ah = mtod(m, struct arphdr *);
|
|
op = ntohs(ah->ar_op);
|
|
(void)memcpy(&isaddr, ar_spa(ah), sizeof (isaddr));
|
|
(void)memcpy(&itaddr, ar_tpa(ah), sizeof (itaddr));
|
|
#ifdef BRIDGE
|
|
#define BRIDGE_TEST (do_bridge)
|
|
#else
|
|
#define BRIDGE_TEST (0) /* cc will optimise the test away */
|
|
#endif
|
|
/*
|
|
* For a bridge, we want to check the address irrespective
|
|
* of the receive interface. (This will change slightly
|
|
* when we have clusters of interfaces).
|
|
*/
|
|
LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash)
|
|
if ((BRIDGE_TEST || (ia->ia_ifp == ifp)) &&
|
|
itaddr.s_addr == ia->ia_addr.sin_addr.s_addr)
|
|
goto match;
|
|
LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash)
|
|
if ((BRIDGE_TEST || (ia->ia_ifp == ifp)) &&
|
|
isaddr.s_addr == ia->ia_addr.sin_addr.s_addr)
|
|
goto match;
|
|
/*
|
|
* No match, use the first inet address on the receive interface
|
|
* as a dummy address for the rest of the function.
|
|
*/
|
|
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
|
|
if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET) {
|
|
ia = ifatoia(ifa);
|
|
goto match;
|
|
}
|
|
/*
|
|
* If bridging, fall back to using any inet address.
|
|
*/
|
|
if (!BRIDGE_TEST ||
|
|
(ia = TAILQ_FIRST(&in_ifaddrhead)) == NULL) {
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
match:
|
|
myaddr = ia->ia_addr.sin_addr;
|
|
if (!bcmp(ar_sha(ah), IF_LLADDR(ifp), ifp->if_addrlen)) {
|
|
m_freem(m); /* it's from me, ignore it. */
|
|
return;
|
|
}
|
|
if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) {
|
|
log(LOG_ERR,
|
|
"arp: link address is broadcast for IP address %s!\n",
|
|
inet_ntoa(isaddr));
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
if (isaddr.s_addr == myaddr.s_addr) {
|
|
log(LOG_ERR,
|
|
"arp: %*D is using my IP address %s!\n",
|
|
ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
|
|
inet_ntoa(isaddr));
|
|
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))) {
|
|
/* the following is not an error when doing bridging */
|
|
if (!BRIDGE_TEST && rt->rt_ifp != ifp) {
|
|
if (log_arp_wrong_iface)
|
|
log(LOG_ERR, "arp: %s is on %s%d but got reply from %*D on %s%d\n",
|
|
inet_ntoa(isaddr),
|
|
rt->rt_ifp->if_name, rt->rt_ifp->if_unit,
|
|
ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
|
|
ifp->if_name, ifp->if_unit);
|
|
goto reply;
|
|
}
|
|
if (sdl->sdl_alen &&
|
|
bcmp(ar_sha(ah), LLADDR(sdl), sdl->sdl_alen)) {
|
|
if (rt->rt_expire) {
|
|
if (log_arp_movements)
|
|
log(LOG_INFO, "arp: %s moved from %*D to %*D on %s%d\n",
|
|
inet_ntoa(isaddr),
|
|
ifp->if_addrlen, (u_char *)LLADDR(sdl), ":",
|
|
ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
|
|
ifp->if_name, ifp->if_unit);
|
|
} else {
|
|
log(LOG_ERR,
|
|
"arp: %*D attempts to modify permanent entry for %s on %s%d\n",
|
|
ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
|
|
inet_ntoa(isaddr), ifp->if_name, ifp->if_unit);
|
|
goto reply;
|
|
}
|
|
}
|
|
/*
|
|
* sanity check for the address length.
|
|
* XXX this does not work for protocols with variable address
|
|
* length. -is
|
|
*/
|
|
if (sdl->sdl_alen &&
|
|
sdl->sdl_alen != ah->ar_hln) {
|
|
log(LOG_WARNING,
|
|
"arp from %*D: new addr len %d, was %d",
|
|
ifp->if_addrlen, (u_char *) ar_sha(ah), ":",
|
|
ah->ar_hln, sdl->sdl_alen);
|
|
}
|
|
if (ifp->if_addrlen != ah->ar_hln) {
|
|
log(LOG_WARNING,
|
|
"arp from %*D: addr len: new %d, i/f %d (ignored)",
|
|
ifp->if_addrlen, (u_char *) ar_sha(ah), ":",
|
|
ah->ar_hln, ifp->if_addrlen);
|
|
goto reply;
|
|
}
|
|
(void)memcpy(LLADDR(sdl), ar_sha(ah),
|
|
sdl->sdl_alen = ah->ar_hln);
|
|
sdl->sdl_rcf = (u_short)0;
|
|
/*
|
|
* If we receive an arp from a token-ring station over
|
|
* a token-ring nic then try to save the source
|
|
* routing info.
|
|
*/
|
|
if (ifp->if_type == IFT_ISO88025) {
|
|
th = (struct iso88025_header *)m->m_pkthdr.header;
|
|
rif_len = TR_RCF_RIFLEN(th->rcf);
|
|
if ((th->iso88025_shost[0] & TR_RII) &&
|
|
(rif_len > 2)) {
|
|
sdl->sdl_rcf = th->rcf;
|
|
sdl->sdl_rcf ^= htons(TR_RCF_DIR);
|
|
memcpy(sdl->sdl_route, th->rd, rif_len - 2);
|
|
sdl->sdl_rcf &= ~htons(TR_RCF_BCST_MASK);
|
|
/*
|
|
* Set up source routing information for
|
|
* reply packet (XXX)
|
|
*/
|
|
m->m_data -= rif_len;
|
|
m->m_len += rif_len;
|
|
m->m_pkthdr.len += rif_len;
|
|
} else {
|
|
th->iso88025_shost[0] &= ~TR_RII;
|
|
}
|
|
m->m_data -= 8;
|
|
m->m_len += 8;
|
|
m->m_pkthdr.len += 8;
|
|
th->rcf = sdl->sdl_rcf;
|
|
} else {
|
|
sdl->sdl_rcf = (u_short)0;
|
|
}
|
|
if (rt->rt_expire)
|
|
rt->rt_expire = time_second + arpt_keep;
|
|
rt->rt_flags &= ~RTF_REJECT;
|
|
la->la_asked = 0;
|
|
if (la->la_hold) {
|
|
(*ifp->if_output)(ifp, la->la_hold,
|
|
rt_key(rt), rt);
|
|
la->la_hold = 0;
|
|
}
|
|
}
|
|
reply:
|
|
if (op != ARPOP_REQUEST) {
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
if (itaddr.s_addr == myaddr.s_addr) {
|
|
/* I am the target */
|
|
(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
|
|
(void)memcpy(ar_sha(ah), IF_LLADDR(ifp), ah->ar_hln);
|
|
} else {
|
|
la = arplookup(itaddr.s_addr, 0, SIN_PROXY);
|
|
if (la == NULL) {
|
|
struct sockaddr_in sin;
|
|
|
|
if (!arp_proxyall) {
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
|
|
bzero(&sin, sizeof sin);
|
|
sin.sin_family = AF_INET;
|
|
sin.sin_len = sizeof sin;
|
|
sin.sin_addr = itaddr;
|
|
|
|
rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL);
|
|
if (!rt) {
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
/*
|
|
* Don't send proxies for nodes on the same interface
|
|
* as this one came out of, or we'll get into a fight
|
|
* over who claims what Ether address.
|
|
*/
|
|
if (rt->rt_ifp == ifp) {
|
|
rtfree(rt);
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
|
|
(void)memcpy(ar_sha(ah), IF_LLADDR(ifp), ah->ar_hln);
|
|
rtfree(rt);
|
|
|
|
/*
|
|
* Also check that the node which sent the ARP packet
|
|
* is on the the interface we expect it to be on. This
|
|
* avoids ARP chaos if an interface is connected to the
|
|
* wrong network.
|
|
*/
|
|
sin.sin_addr = isaddr;
|
|
|
|
rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL);
|
|
if (!rt) {
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
if (rt->rt_ifp != ifp) {
|
|
log(LOG_INFO, "arp_proxy: ignoring request"
|
|
" from %s via %s%d, expecting %s%d\n",
|
|
inet_ntoa(isaddr), ifp->if_name,
|
|
ifp->if_unit, rt->rt_ifp->if_name,
|
|
rt->rt_ifp->if_unit);
|
|
rtfree(rt);
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
rtfree(rt);
|
|
|
|
#ifdef DEBUG_PROXY
|
|
printf("arp: proxying for %s\n",
|
|
inet_ntoa(itaddr));
|
|
#endif
|
|
} else {
|
|
rt = la->la_rt;
|
|
(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
|
|
sdl = SDL(rt->rt_gateway);
|
|
(void)memcpy(ar_sha(ah), LLADDR(sdl), ah->ar_hln);
|
|
}
|
|
}
|
|
|
|
(void)memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln);
|
|
(void)memcpy(ar_spa(ah), &itaddr, ah->ar_pln);
|
|
ah->ar_op = htons(ARPOP_REPLY);
|
|
ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */
|
|
switch (ifp->if_type) {
|
|
case IFT_ARCNET:
|
|
arh = (struct arc_header *)sa.sa_data;
|
|
arh->arc_dhost = *ar_tha(ah);
|
|
arh->arc_type = ARCTYPE_ARP;
|
|
break;
|
|
|
|
case IFT_ISO88025:
|
|
/* Re-arrange the source/dest address */
|
|
memcpy(th->iso88025_dhost, th->iso88025_shost,
|
|
sizeof(th->iso88025_dhost));
|
|
memcpy(th->iso88025_shost, IF_LLADDR(ifp),
|
|
sizeof(th->iso88025_shost));
|
|
/* Set the source routing bit if neccesary */
|
|
if (th->iso88025_dhost[0] & TR_RII) {
|
|
th->iso88025_dhost[0] &= ~TR_RII;
|
|
if (TR_RCF_RIFLEN(th->rcf) > 2)
|
|
th->iso88025_shost[0] |= TR_RII;
|
|
}
|
|
/* Copy the addresses, ac and fc into sa_data */
|
|
memcpy(sa.sa_data, th->iso88025_dhost,
|
|
sizeof(th->iso88025_dhost) * 2);
|
|
sa.sa_data[(sizeof(th->iso88025_dhost) * 2)] = TR_AC;
|
|
sa.sa_data[(sizeof(th->iso88025_dhost) * 2) + 1] = TR_LLC_FRAME;
|
|
break;
|
|
case IFT_ETHER:
|
|
case IFT_FDDI:
|
|
/*
|
|
* May not be correct for types not explictly
|
|
* listed, but it is our best guess.
|
|
*/
|
|
default:
|
|
eh = (struct ether_header *)sa.sa_data;
|
|
(void)memcpy(eh->ether_dhost, ar_tha(ah),
|
|
sizeof(eh->ether_dhost));
|
|
eh->ether_type = htons(ETHERTYPE_ARP);
|
|
break;
|
|
}
|
|
sa.sa_family = AF_UNSPEC;
|
|
sa.sa_len = sizeof(sa);
|
|
(*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0);
|
|
return;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* 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_long addr;
|
|
int create, proxy;
|
|
{
|
|
register struct rtentry *rt;
|
|
static struct sockaddr_inarp sin = {sizeof(sin), AF_INET };
|
|
const char *why = 0;
|
|
|
|
sin.sin_addr.s_addr = addr;
|
|
sin.sin_other = proxy ? SIN_PROXY : 0;
|
|
rt = rtalloc1((struct sockaddr *)&sin, create, 0UL);
|
|
if (rt == 0)
|
|
return (0);
|
|
rt->rt_refcnt--;
|
|
|
|
if (rt->rt_flags & RTF_GATEWAY)
|
|
why = "host is not on local network";
|
|
else if ((rt->rt_flags & RTF_LLINFO) == 0)
|
|
why = "could not allocate llinfo";
|
|
else if (rt->rt_gateway->sa_family != AF_LINK)
|
|
why = "gateway route is not ours";
|
|
|
|
if (why && create) {
|
|
log(LOG_DEBUG, "arplookup %s failed: %s\n",
|
|
inet_ntoa(sin.sin_addr), why);
|
|
return 0;
|
|
} else if (why) {
|
|
return 0;
|
|
}
|
|
return ((struct llinfo_arp *)rt->rt_llinfo);
|
|
}
|
|
|
|
void
|
|
arp_ifinit(ifp, ifa)
|
|
struct ifnet *ifp;
|
|
struct ifaddr *ifa;
|
|
{
|
|
if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY)
|
|
arprequest(ifp, &IA_SIN(ifa)->sin_addr,
|
|
&IA_SIN(ifa)->sin_addr, IF_LLADDR(ifp));
|
|
ifa->ifa_rtrequest = arp_rtrequest;
|
|
ifa->ifa_flags |= RTF_CLONING;
|
|
}
|
|
|
|
static void
|
|
arp_init(void)
|
|
{
|
|
|
|
arpintrq.ifq_maxlen = 50;
|
|
mtx_init(&arpintrq.ifq_mtx, "arp_inq", MTX_DEF);
|
|
}
|
|
|
|
SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0);
|