975 lines
27 KiB
C
975 lines
27 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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* 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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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_inet.h"
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#include "opt_mac.h"
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#include "opt_carp.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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#include <net/ethernet.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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#include <net/if_arc.h>
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#include <net/iso88025.h>
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#ifdef DEV_CARP
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#include <netinet/ip_carp.h>
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#endif
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#include <security/mac/mac_framework.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_keep = (20*60); /* once resolved, good for 20 more minutes */
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SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW,
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&arpt_keep, 0, "ARP entry lifetime in seconds");
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#define rt_expire rt_rmx.rmx_expire
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struct llinfo_arp {
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struct callout la_timer;
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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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u_short la_preempt; /* countdown for pre-expiry arps */
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u_short la_asked; /* # requests sent */
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};
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static struct ifqueue arpintrq;
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static int 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, "ARP resolution attempts before returning error");
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SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW,
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&useloopback, 0, "Use the loopback interface for local traffic");
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SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW,
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&arp_proxyall, 0, "Enable proxy ARP for all suitable requests");
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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(struct mbuf *);
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static void arptimer(void *);
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static struct rtentry
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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.
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*/
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static void
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arptimer(void *arg)
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{
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struct rtentry *rt = (struct rtentry *)arg;
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RT_LOCK_ASSERT(rt);
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/*
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* The lock is needed to close a theoretical race
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* between spontaneous expiry and intentional removal.
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* We still got an extra reference on rtentry, so can
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* safely pass pointers to its contents.
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*/
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RT_UNLOCK(rt);
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rtrequest(RTM_DELETE, rt_key(rt), NULL, rt_mask(rt), 0, NULL);
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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(int req, struct rtentry *rt, struct rt_addrinfo *info)
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{
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struct sockaddr *gate;
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struct llinfo_arp *la;
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static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
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struct in_ifaddr *ia;
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struct ifaddr *ifa;
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RT_LOCK_ASSERT(rt);
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if (rt->rt_flags & RTF_GATEWAY)
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return;
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gate = rt->rt_gateway;
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la = (struct llinfo_arp *)rt->rt_llinfo;
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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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rt_mask(rt) != NULL &&
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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_uptime;
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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, "%s: bad gateway %s%s\n", __func__,
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inet_ntoa(SIN(rt_key(rt))->sin_addr),
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(gate->sa_family != AF_LINK) ?
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" (!AF_LINK)": "");
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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_Zalloc(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, "%s: malloc failed\n", __func__);
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break;
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}
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arp_allocated++;
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/*
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* We are storing a route entry outside of radix tree. So,
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* it can be found and accessed by other means than radix
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* lookup. The routing code assumes that any rtentry detached
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* from radix can be destroyed safely. To prevent this, we
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* add an additional reference.
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*/
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RT_ADDREF(rt);
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la->la_rt = rt;
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rt->rt_flags |= RTF_LLINFO;
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callout_init_mtx(&la->la_timer, &rt->rt_mtx,
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CALLOUT_RETURNUNLOCKED);
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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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TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link) {
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if (ia->ia_ifp == rt->rt_ifp &&
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SIN(rt_key(rt))->sin_addr.s_addr ==
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(IA_SIN(ia))->sin_addr.s_addr)
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break;
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}
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if (ia) {
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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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rt->rt_rmx.rmx_mtu = loif->if_mtu;
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}
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/*
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* make sure to set rt->rt_ifa to the interface
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* address we are using, otherwise we will have trouble
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* with source address selection.
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*/
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ifa = &ia->ia_ifa;
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if (ifa != rt->rt_ifa) {
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IFAFREE(rt->rt_ifa);
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IFAREF(ifa);
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rt->rt_ifa = ifa;
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}
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}
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break;
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case RTM_DELETE:
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if (la == NULL) /* XXX: at least CARP does this. */
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break;
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callout_stop(&la->la_timer);
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rt->rt_llinfo = NULL;
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rt->rt_flags &= ~RTF_LLINFO;
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RT_REMREF(rt);
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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(struct ifnet *ifp, struct in_addr *sip, struct in_addr *tip,
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u_char *enaddr)
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{
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struct mbuf *m;
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struct arphdr *ah;
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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(*ah) + 2*sizeof(struct in_addr) +
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2*ifp->if_data.ifi_addrlen;
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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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ah = mtod(m, struct arphdr *);
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bzero((caddr_t)ah, m->m_len);
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#ifdef MAC
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mac_netinet_arp_send(ifp, m);
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#endif
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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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bcopy((caddr_t)enaddr, (caddr_t)ar_sha(ah), ah->ar_hln);
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bcopy((caddr_t)sip, (caddr_t)ar_spa(ah), ah->ar_pln);
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bcopy((caddr_t)tip, (caddr_t)ar_tpa(ah), ah->ar_pln);
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sa.sa_family = AF_ARP;
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sa.sa_len = 2;
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m->m_flags |= M_BCAST;
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(*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0);
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return;
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}
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/*
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* Resolve an IP address into an ethernet address.
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* On input:
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* ifp is the interface we use
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* dst is the next hop,
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* rt0 is the route to the final destination (possibly useless)
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* m is the mbuf
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* desten is where we want the address.
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*
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* On success, desten is filled in and the function returns 0;
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* If the packet must be held pending resolution, we return EWOULDBLOCK
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* On other errors, we return the corresponding error code.
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*/
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int
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arpresolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m,
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struct sockaddr *dst, u_char *desten)
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{
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struct llinfo_arp *la = NULL;
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struct rtentry *rt = NULL;
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struct sockaddr_dl *sdl;
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int error;
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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 (0);
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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 (0);
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}
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if (rt0 != NULL) {
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error = rt_check(&rt, &rt0, dst);
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if (error) {
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m_freem(m);
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return error;
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}
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la = (struct llinfo_arp *)rt->rt_llinfo;
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if (la == NULL)
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RT_UNLOCK(rt);
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}
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if (la == NULL) {
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/*
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* We enter this block in case if rt0 was NULL,
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* or if rt found by rt_check() didn't have llinfo.
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*/
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rt = arplookup(SIN(dst)->sin_addr.s_addr, 1, 0);
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if (rt == NULL) {
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log(LOG_DEBUG,
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"arpresolve: can't allocate route for %s\n",
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inet_ntoa(SIN(dst)->sin_addr));
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m_freem(m);
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return (EINVAL); /* XXX */
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}
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la = (struct llinfo_arp *)rt->rt_llinfo;
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if (la == NULL) {
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RT_UNLOCK(rt);
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log(LOG_DEBUG,
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"arpresolve: can't allocate llinfo for %s\n",
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inet_ntoa(SIN(dst)->sin_addr));
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m_freem(m);
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return (EINVAL); /* XXX */
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}
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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_uptime) &&
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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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/*
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* If entry has an expiry time and it is approaching,
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* send an ARP request.
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*/
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if ((rt->rt_expire != 0) &&
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(time_uptime + la->la_preempt > rt->rt_expire)) {
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struct in_addr sin =
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SIN(rt->rt_ifa->ifa_addr)->sin_addr;
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la->la_preempt--;
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RT_UNLOCK(rt);
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arprequest(ifp, &sin, &SIN(dst)->sin_addr,
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IF_LLADDR(ifp));
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return (0);
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}
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RT_UNLOCK(rt);
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return (0);
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}
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/*
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* If ARP is disabled or static on this interface, stop.
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* XXX
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* Probably should not allocate empty llinfo struct if we are
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* not going to be sending out an arp request.
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*/
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if (ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) {
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RT_UNLOCK(rt);
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m_freem(m);
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return (EINVAL);
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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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KASSERT(rt->rt_expire > 0, ("sending ARP request for static entry"));
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/*
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* Return EWOULDBLOCK if we have tried less than arp_maxtries. It
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* will be masked by ether_output(). Return EHOSTDOWN/EHOSTUNREACH
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* if we have already sent arp_maxtries ARP requests. Retransmit the
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* ARP request, but not faster than one request per second.
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*/
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if (la->la_asked < arp_maxtries)
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error = EWOULDBLOCK; /* First request. */
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else
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error = (rt == rt0) ? EHOSTDOWN : EHOSTUNREACH;
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if (la->la_asked == 0 || rt->rt_expire != time_uptime) {
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struct in_addr sin =
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SIN(rt->rt_ifa->ifa_addr)->sin_addr;
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rt->rt_expire = time_uptime;
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callout_reset(&la->la_timer, hz, arptimer, rt);
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la->la_asked++;
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RT_UNLOCK(rt);
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arprequest(ifp, &sin, &SIN(dst)->sin_addr,
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IF_LLADDR(ifp));
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} else
|
|
RT_UNLOCK(rt);
|
|
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Common length and type checks are done here,
|
|
* then the protocol-specific routine is called.
|
|
*/
|
|
static void
|
|
arpintr(struct mbuf *m)
|
|
{
|
|
struct arphdr *ar;
|
|
|
|
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");
|
|
return;
|
|
}
|
|
ar = mtod(m, struct arphdr *);
|
|
|
|
if (ntohs(ar->ar_hrd) != ARPHRD_ETHER &&
|
|
ntohs(ar->ar_hrd) != ARPHRD_IEEE802 &&
|
|
ntohs(ar->ar_hrd) != ARPHRD_ARCNET &&
|
|
ntohs(ar->ar_hrd) != ARPHRD_IEEE1394) {
|
|
log(LOG_ERR, "arp: unknown hardware address format (0x%2D)\n",
|
|
(unsigned char *)&ar->ar_hrd, "");
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
|
|
if (m->m_len < arphdr_len(ar)) {
|
|
if ((m = m_pullup(m, arphdr_len(ar))) == NULL) {
|
|
log(LOG_ERR, "arp: runt packet\n");
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
ar = mtod(m, struct arphdr *);
|
|
}
|
|
|
|
switch (ntohs(ar->ar_pro)) {
|
|
#ifdef INET
|
|
case ETHERTYPE_IP:
|
|
in_arpinput(m);
|
|
return;
|
|
#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;
|
|
static int log_arp_permanent_modify = 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");
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_permanent_modify, CTLFLAG_RW,
|
|
&log_arp_permanent_modify, 0,
|
|
"log arp replies from MACs different than the one in the permanent arp entry");
|
|
|
|
|
|
static void
|
|
in_arpinput(struct mbuf *m)
|
|
{
|
|
struct arphdr *ah;
|
|
struct ifnet *ifp = m->m_pkthdr.rcvif;
|
|
struct llinfo_arp *la;
|
|
struct rtentry *rt;
|
|
struct ifaddr *ifa;
|
|
struct in_ifaddr *ia;
|
|
struct sockaddr_dl *sdl;
|
|
struct sockaddr sa;
|
|
struct in_addr isaddr, itaddr, myaddr;
|
|
struct mbuf *hold;
|
|
u_int8_t *enaddr = NULL;
|
|
int op, rif_len;
|
|
int req_len;
|
|
int bridged = 0;
|
|
#ifdef DEV_CARP
|
|
int carp_match = 0;
|
|
#endif
|
|
struct sockaddr_in sin;
|
|
sin.sin_len = sizeof(struct sockaddr_in);
|
|
sin.sin_family = AF_INET;
|
|
|
|
if (ifp->if_bridge)
|
|
bridged = 1;
|
|
|
|
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));
|
|
|
|
/*
|
|
* For a bridge, we want to check the address irrespective
|
|
* of the receive interface. (This will change slightly
|
|
* when we have clusters of interfaces).
|
|
* If the interface does not match, but the recieving interface
|
|
* is part of carp, we call carp_iamatch to see if this is a
|
|
* request for the virtual host ip.
|
|
* XXX: This is really ugly!
|
|
*/
|
|
LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) {
|
|
if (((bridged && ia->ia_ifp->if_bridge != NULL) ||
|
|
(ia->ia_ifp == ifp)) &&
|
|
itaddr.s_addr == ia->ia_addr.sin_addr.s_addr)
|
|
goto match;
|
|
#ifdef DEV_CARP
|
|
if (ifp->if_carp != NULL &&
|
|
carp_iamatch(ifp->if_carp, ia, &isaddr, &enaddr) &&
|
|
itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {
|
|
carp_match = 1;
|
|
goto match;
|
|
}
|
|
#endif
|
|
}
|
|
LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash)
|
|
if (((bridged && ia->ia_ifp->if_bridge != NULL) ||
|
|
(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->sa_family == AF_INET) {
|
|
ia = ifatoia(ifa);
|
|
goto match;
|
|
}
|
|
/*
|
|
* If bridging, fall back to using any inet address.
|
|
*/
|
|
if (!bridged || (ia = TAILQ_FIRST(&in_ifaddrhead)) == NULL)
|
|
goto drop;
|
|
match:
|
|
if (!enaddr)
|
|
enaddr = (u_int8_t *)IF_LLADDR(ifp);
|
|
myaddr = ia->ia_addr.sin_addr;
|
|
if (!bcmp(ar_sha(ah), enaddr, ifp->if_addrlen))
|
|
goto drop; /* it's from me, ignore it. */
|
|
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));
|
|
goto drop;
|
|
}
|
|
/*
|
|
* Warn if another host is using the same IP address, but only if the
|
|
* IP address isn't 0.0.0.0, which is used for DHCP only, in which
|
|
* case we suppress the warning to avoid false positive complaints of
|
|
* potential misconfiguration.
|
|
*/
|
|
if (!bridged && isaddr.s_addr == myaddr.s_addr && myaddr.s_addr != 0) {
|
|
log(LOG_ERR,
|
|
"arp: %*D is using my IP address %s on %s!\n",
|
|
ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
|
|
inet_ntoa(isaddr), ifp->if_xname);
|
|
itaddr = myaddr;
|
|
goto reply;
|
|
}
|
|
if (ifp->if_flags & IFF_STATICARP)
|
|
goto reply;
|
|
rt = arplookup(isaddr.s_addr, itaddr.s_addr == myaddr.s_addr, 0);
|
|
if (rt != NULL) {
|
|
sin.sin_addr.s_addr = isaddr.s_addr;
|
|
EVENTHANDLER_INVOKE(route_event, RTEVENT_ARP_UPDATE, rt, NULL,
|
|
(struct sockaddr *)&sin);
|
|
|
|
la = (struct llinfo_arp *)rt->rt_llinfo;
|
|
if (la == NULL) {
|
|
RT_UNLOCK(rt);
|
|
goto reply;
|
|
}
|
|
} else
|
|
goto reply;
|
|
|
|
/* The following is not an error when doing bridging. */
|
|
if (!bridged && rt->rt_ifp != ifp
|
|
#ifdef DEV_CARP
|
|
&& (ifp->if_type != IFT_CARP || !carp_match)
|
|
#endif
|
|
) {
|
|
if (log_arp_wrong_iface)
|
|
log(LOG_ERR, "arp: %s is on %s but got reply from %*D on %s\n",
|
|
inet_ntoa(isaddr),
|
|
rt->rt_ifp->if_xname,
|
|
ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
|
|
ifp->if_xname);
|
|
RT_UNLOCK(rt);
|
|
goto reply;
|
|
}
|
|
sdl = SDL(rt->rt_gateway);
|
|
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\n",
|
|
inet_ntoa(isaddr),
|
|
ifp->if_addrlen, (u_char *)LLADDR(sdl), ":",
|
|
ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
|
|
ifp->if_xname);
|
|
} else {
|
|
RT_UNLOCK(rt);
|
|
if (log_arp_permanent_modify)
|
|
log(LOG_ERR, "arp: %*D attempts to modify "
|
|
"permanent entry for %s on %s\n",
|
|
ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
|
|
inet_ntoa(isaddr), ifp->if_xname);
|
|
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);
|
|
RT_UNLOCK(rt);
|
|
goto reply;
|
|
}
|
|
(void)memcpy(LLADDR(sdl), ar_sha(ah),
|
|
sdl->sdl_alen = ah->ar_hln);
|
|
/*
|
|
* 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) {
|
|
struct iso88025_header *th = NULL;
|
|
struct iso88025_sockaddr_dl_data *trld;
|
|
|
|
th = (struct iso88025_header *)m->m_pkthdr.header;
|
|
trld = SDL_ISO88025(sdl);
|
|
rif_len = TR_RCF_RIFLEN(th->rcf);
|
|
if ((th->iso88025_shost[0] & TR_RII) &&
|
|
(rif_len > 2)) {
|
|
trld->trld_rcf = th->rcf;
|
|
trld->trld_rcf ^= htons(TR_RCF_DIR);
|
|
memcpy(trld->trld_route, th->rd, rif_len - 2);
|
|
trld->trld_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;
|
|
trld->trld_rcf = 0;
|
|
}
|
|
m->m_data -= 8;
|
|
m->m_len += 8;
|
|
m->m_pkthdr.len += 8;
|
|
th->rcf = trld->trld_rcf;
|
|
}
|
|
if (rt->rt_expire) {
|
|
rt->rt_expire = time_uptime + arpt_keep;
|
|
callout_reset(&la->la_timer, hz * arpt_keep, arptimer, rt);
|
|
}
|
|
la->la_asked = 0;
|
|
la->la_preempt = arp_maxtries;
|
|
hold = la->la_hold;
|
|
la->la_hold = NULL;
|
|
RT_UNLOCK(rt);
|
|
if (hold != NULL)
|
|
(*ifp->if_output)(ifp, hold, rt_key(rt), rt);
|
|
|
|
reply:
|
|
if (op != ARPOP_REQUEST)
|
|
goto drop;
|
|
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), enaddr, ah->ar_hln);
|
|
} else {
|
|
rt = arplookup(itaddr.s_addr, 0, SIN_PROXY);
|
|
if (rt == NULL) {
|
|
struct sockaddr_in sin;
|
|
|
|
if (!arp_proxyall)
|
|
goto drop;
|
|
|
|
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)
|
|
goto drop;
|
|
/*
|
|
* 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);
|
|
goto drop;
|
|
}
|
|
(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
|
|
(void)memcpy(ar_sha(ah), enaddr, 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)
|
|
goto drop;
|
|
if (rt->rt_ifp != ifp) {
|
|
log(LOG_INFO, "arp_proxy: ignoring request"
|
|
" from %s via %s, expecting %s\n",
|
|
inet_ntoa(isaddr), ifp->if_xname,
|
|
rt->rt_ifp->if_xname);
|
|
rtfree(rt);
|
|
goto drop;
|
|
}
|
|
rtfree(rt);
|
|
|
|
#ifdef DEBUG_PROXY
|
|
printf("arp: proxying for %s\n",
|
|
inet_ntoa(itaddr));
|
|
#endif
|
|
} else {
|
|
/*
|
|
* Return proxied ARP replies only on the interface
|
|
* or bridge cluster where this network resides.
|
|
* Otherwise we may conflict with the host we are
|
|
* proxying for.
|
|
*/
|
|
if (rt->rt_ifp != ifp &&
|
|
(rt->rt_ifp->if_bridge != ifp->if_bridge ||
|
|
ifp->if_bridge == NULL)) {
|
|
RT_UNLOCK(rt);
|
|
goto drop;
|
|
}
|
|
sdl = SDL(rt->rt_gateway);
|
|
(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
|
|
(void)memcpy(ar_sha(ah), LLADDR(sdl), ah->ar_hln);
|
|
RT_UNLOCK(rt);
|
|
}
|
|
}
|
|
|
|
if (itaddr.s_addr == myaddr.s_addr &&
|
|
IN_LINKLOCAL(ntohl(itaddr.s_addr))) {
|
|
/* RFC 3927 link-local IPv4; always reply by broadcast. */
|
|
#ifdef DEBUG_LINKLOCAL
|
|
printf("arp: sending reply for link-local addr %s\n",
|
|
inet_ntoa(itaddr));
|
|
#endif
|
|
m->m_flags |= M_BCAST;
|
|
m->m_flags &= ~M_MCAST;
|
|
} else {
|
|
/* default behaviour; never reply by broadcast. */
|
|
m->m_flags &= ~(M_BCAST|M_MCAST);
|
|
}
|
|
(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! */
|
|
m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln);
|
|
m->m_pkthdr.len = m->m_len;
|
|
sa.sa_family = AF_ARP;
|
|
sa.sa_len = 2;
|
|
(*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0);
|
|
return;
|
|
|
|
drop:
|
|
m_freem(m);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Lookup or enter a new address in arptab.
|
|
*/
|
|
static struct rtentry *
|
|
arplookup(u_long addr, int create, int proxy)
|
|
{
|
|
struct rtentry *rt;
|
|
struct sockaddr_inarp sin;
|
|
const char *why = 0;
|
|
|
|
bzero(&sin, sizeof(sin));
|
|
sin.sin_len = sizeof(sin);
|
|
sin.sin_family = AF_INET;
|
|
sin.sin_addr.s_addr = addr;
|
|
if (proxy)
|
|
sin.sin_other = SIN_PROXY;
|
|
rt = rtalloc1((struct sockaddr *)&sin, create, 0UL);
|
|
if (rt == 0)
|
|
return (0);
|
|
|
|
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) {
|
|
#define ISDYNCLONE(_rt) \
|
|
(((_rt)->rt_flags & (RTF_STATIC | RTF_WASCLONED)) == RTF_WASCLONED)
|
|
if (create)
|
|
log(LOG_DEBUG, "arplookup %s failed: %s\n",
|
|
inet_ntoa(sin.sin_addr), why);
|
|
/*
|
|
* If there are no references to this Layer 2 route,
|
|
* and it is a cloned route, and not static, and
|
|
* arplookup() is creating the route, then purge
|
|
* it from the routing table as it is probably bogus.
|
|
*/
|
|
if (rt->rt_refcnt == 1 && ISDYNCLONE(rt))
|
|
rtexpunge(rt);
|
|
RTFREE_LOCKED(rt);
|
|
return (0);
|
|
#undef ISDYNCLONE
|
|
} else {
|
|
RT_REMREF(rt);
|
|
return (rt);
|
|
}
|
|
}
|
|
|
|
void
|
|
arp_ifinit(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;
|
|
}
|
|
|
|
void
|
|
arp_ifinit2(struct ifnet *ifp, struct ifaddr *ifa, u_char *enaddr)
|
|
{
|
|
if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY)
|
|
arprequest(ifp, &IA_SIN(ifa)->sin_addr,
|
|
&IA_SIN(ifa)->sin_addr, enaddr);
|
|
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", NULL, MTX_DEF);
|
|
netisr_register(NETISR_ARP, arpintr, &arpintrq, NETISR_MPSAFE);
|
|
}
|
|
SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0);
|