xref: /freebsd/sys/netinet/if_ether.c (revision eddfbb763ded6b5f6777335142be9a0edab628bb)
1c398230bSWarner Losh /*-
2df8bae1dSRodney W. Grimes  * Copyright (c) 1982, 1986, 1988, 1993
3df8bae1dSRodney W. Grimes  *	The Regents of the University of California.  All rights reserved.
4df8bae1dSRodney W. Grimes  *
5df8bae1dSRodney W. Grimes  * Redistribution and use in source and binary forms, with or without
6df8bae1dSRodney W. Grimes  * modification, are permitted provided that the following conditions
7df8bae1dSRodney W. Grimes  * are met:
8df8bae1dSRodney W. Grimes  * 1. Redistributions of source code must retain the above copyright
9df8bae1dSRodney W. Grimes  *    notice, this list of conditions and the following disclaimer.
10df8bae1dSRodney W. Grimes  * 2. Redistributions in binary form must reproduce the above copyright
11df8bae1dSRodney W. Grimes  *    notice, this list of conditions and the following disclaimer in the
12df8bae1dSRodney W. Grimes  *    documentation and/or other materials provided with the distribution.
13df8bae1dSRodney W. Grimes  * 4. Neither the name of the University nor the names of its contributors
14df8bae1dSRodney W. Grimes  *    may be used to endorse or promote products derived from this software
15df8bae1dSRodney W. Grimes  *    without specific prior written permission.
16df8bae1dSRodney W. Grimes  *
17df8bae1dSRodney W. Grimes  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18df8bae1dSRodney W. Grimes  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19df8bae1dSRodney W. Grimes  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20df8bae1dSRodney W. Grimes  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21df8bae1dSRodney W. Grimes  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22df8bae1dSRodney W. Grimes  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23df8bae1dSRodney W. Grimes  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24df8bae1dSRodney W. Grimes  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25df8bae1dSRodney W. Grimes  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26df8bae1dSRodney W. Grimes  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27df8bae1dSRodney W. Grimes  * SUCH DAMAGE.
28df8bae1dSRodney W. Grimes  *
29df8bae1dSRodney W. Grimes  *	@(#)if_ether.c	8.1 (Berkeley) 6/10/93
30df8bae1dSRodney W. Grimes  */
31df8bae1dSRodney W. Grimes 
32df8bae1dSRodney W. Grimes /*
33df8bae1dSRodney W. Grimes  * Ethernet address resolution protocol.
34df8bae1dSRodney W. Grimes  * TODO:
35df8bae1dSRodney W. Grimes  *	add "inuse/lock" bit (or ref. count) along with valid bit
36df8bae1dSRodney W. Grimes  */
37df8bae1dSRodney W. Grimes 
384b421e2dSMike Silbersack #include <sys/cdefs.h>
394b421e2dSMike Silbersack __FBSDID("$FreeBSD$");
404b421e2dSMike Silbersack 
411d5e9e22SEivind Eklund #include "opt_inet.h"
42a9771948SGleb Smirnoff #include "opt_carp.h"
431d5e9e22SEivind Eklund 
44df8bae1dSRodney W. Grimes #include <sys/param.h>
45df8bae1dSRodney W. Grimes #include <sys/kernel.h>
46ce02431fSDoug Rabson #include <sys/queue.h>
47885f1aa4SPoul-Henning Kamp #include <sys/sysctl.h>
48885f1aa4SPoul-Henning Kamp #include <sys/systm.h>
49885f1aa4SPoul-Henning Kamp #include <sys/mbuf.h>
50885f1aa4SPoul-Henning Kamp #include <sys/malloc.h>
51de34ad3fSJulian Elischer #include <sys/proc.h>
524458ac71SBruce Evans #include <sys/socket.h>
53885f1aa4SPoul-Henning Kamp #include <sys/syslog.h>
54603724d3SBjoern A. Zeeb #include <sys/vimage.h>
55df8bae1dSRodney W. Grimes 
56df8bae1dSRodney W. Grimes #include <net/if.h>
57df8bae1dSRodney W. Grimes #include <net/if_dl.h>
58722012ccSJulian Elischer #include <net/if_types.h>
59748e0b0aSGarrett Wollman #include <net/netisr.h>
60b149dd6cSLarry Lile #include <net/if_llc.h>
61c8f8e9c1SJulian Elischer #include <net/ethernet.h>
625736e6fbSBjoern A. Zeeb #include <net/route.h>
63df8bae1dSRodney W. Grimes 
64df8bae1dSRodney W. Grimes #include <netinet/in.h>
65df8bae1dSRodney W. Grimes #include <netinet/in_var.h>
666e6b3f7cSQing Li #include <net/if_llatbl.h>
67df8bae1dSRodney W. Grimes #include <netinet/if_ether.h>
68df8bae1dSRodney W. Grimes 
69322dcb8dSMax Khon #include <net/if_arc.h>
70fda82fc2SJulian Elischer #include <net/iso88025.h>
71fda82fc2SJulian Elischer 
72a9771948SGleb Smirnoff #ifdef DEV_CARP
73a9771948SGleb Smirnoff #include <netinet/ip_carp.h>
74a9771948SGleb Smirnoff #endif
75a9771948SGleb Smirnoff 
76aed55708SRobert Watson #include <security/mac/mac_framework.h>
77aed55708SRobert Watson 
78df8bae1dSRodney W. Grimes #define SIN(s) ((struct sockaddr_in *)s)
79df8bae1dSRodney W. Grimes #define SDL(s) ((struct sockaddr_dl *)s)
80df8bae1dSRodney W. Grimes 
81ce02431fSDoug Rabson SYSCTL_DECL(_net_link_ether);
82602d513cSGarrett Wollman SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, "");
83df8bae1dSRodney W. Grimes 
84df8bae1dSRodney W. Grimes /* timer values */
85eddfbb76SRobert Watson static VNET_DEFINE(int, arpt_keep) = (20*60);	/* once resolved, good for 20
86eddfbb76SRobert Watson 						 * minutes */
87eddfbb76SRobert Watson static VNET_DEFINE(int, arp_maxtries) = 5;
88eddfbb76SRobert Watson static VNET_DEFINE(int, useloopback) = 1;	/* use loopback interface for
89eddfbb76SRobert Watson 						 * local traffic */
90eddfbb76SRobert Watson static VNET_DEFINE(int, arp_proxyall);
91885f1aa4SPoul-Henning Kamp 
92eddfbb76SRobert Watson #define	V_arpt_keep		VNET_GET(arpt_keep)
93eddfbb76SRobert Watson #define	V_arp_maxtries		VNET_GET(arp_maxtries)
94eddfbb76SRobert Watson #define	V_useloopback		VNET_GET(useloopback)
95eddfbb76SRobert Watson #define	V_arp_proxyall		VNET_GET(arp_proxyall)
96885f1aa4SPoul-Henning Kamp 
97eddfbb76SRobert Watson SYSCTL_VNET_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW,
98eddfbb76SRobert Watson 	&VNET_NAME(arpt_keep), 0,
99eddfbb76SRobert Watson 	"ARP entry lifetime in seconds");
100eddfbb76SRobert Watson 
101eddfbb76SRobert Watson SYSCTL_VNET_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW,
102eddfbb76SRobert Watson 	&VNET_NAME(arp_maxtries), 0,
1038b615593SMarko Zec 	"ARP resolution attempts before returning error");
104eddfbb76SRobert Watson SYSCTL_VNET_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW,
105eddfbb76SRobert Watson 	&VNET_NAME(useloopback), 0,
1068b615593SMarko Zec 	"Use the loopback interface for local traffic");
107eddfbb76SRobert Watson SYSCTL_VNET_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW,
108eddfbb76SRobert Watson 	&VNET_NAME(arp_proxyall), 0,
1098b615593SMarko Zec 	"Enable proxy ARP for all suitable requests");
110885f1aa4SPoul-Henning Kamp 
1114d77a549SAlfred Perlstein static void	arp_init(void);
1126e6b3f7cSQing Li void		arprequest(struct ifnet *,
1134d77a549SAlfred Perlstein 			struct in_addr *, struct in_addr *, u_char *);
1141cafed39SJonathan Lemon static void	arpintr(struct mbuf *);
1154d77a549SAlfred Perlstein static void	arptimer(void *);
1161d5e9e22SEivind Eklund #ifdef INET
1174d77a549SAlfred Perlstein static void	in_arpinput(struct mbuf *);
1181d5e9e22SEivind Eklund #endif
11928e82295SGarrett Wollman 
120d4b5cae4SRobert Watson static const struct netisr_handler arp_nh = {
121d4b5cae4SRobert Watson 	.nh_name = "arp",
122d4b5cae4SRobert Watson 	.nh_handler = arpintr,
123d4b5cae4SRobert Watson 	.nh_proto = NETISR_ARP,
124d4b5cae4SRobert Watson 	.nh_policy = NETISR_POLICY_SOURCE,
125d4b5cae4SRobert Watson };
126d4b5cae4SRobert Watson 
1276e6b3f7cSQing Li #ifdef AF_INET
1286e6b3f7cSQing Li void arp_ifscrub(struct ifnet *ifp, uint32_t addr);
1296e6b3f7cSQing Li 
130df8bae1dSRodney W. Grimes /*
1316e6b3f7cSQing Li  * called by in_ifscrub to remove entry from the table when
1326e6b3f7cSQing Li  * the interface goes away
1336e6b3f7cSQing Li  */
1346e6b3f7cSQing Li void
1356e6b3f7cSQing Li arp_ifscrub(struct ifnet *ifp, uint32_t addr)
1366e6b3f7cSQing Li {
1376e6b3f7cSQing Li 	struct sockaddr_in addr4;
1386e6b3f7cSQing Li 
1396e6b3f7cSQing Li 	bzero((void *)&addr4, sizeof(addr4));
1406e6b3f7cSQing Li 	addr4.sin_len    = sizeof(addr4);
1416e6b3f7cSQing Li 	addr4.sin_family = AF_INET;
1426e6b3f7cSQing Li 	addr4.sin_addr.s_addr = addr;
14321ca7b57SMarko Zec 	CURVNET_SET(ifp->if_vnet);
1446e6b3f7cSQing Li 	IF_AFDATA_LOCK(ifp);
1456e6b3f7cSQing Li 	lla_lookup(LLTABLE(ifp), (LLE_DELETE | LLE_IFADDR),
1466e6b3f7cSQing Li 	    (struct sockaddr *)&addr4);
1476e6b3f7cSQing Li 	IF_AFDATA_UNLOCK(ifp);
14821ca7b57SMarko Zec 	CURVNET_RESTORE();
1496e6b3f7cSQing Li }
1506e6b3f7cSQing Li #endif
1516e6b3f7cSQing Li 
1526e6b3f7cSQing Li /*
1536e6b3f7cSQing Li  * Timeout routine.  Age arp_tab entries periodically.
154df8bae1dSRodney W. Grimes  */
155df8bae1dSRodney W. Grimes static void
1561daaa65dSGleb Smirnoff arptimer(void *arg)
157df8bae1dSRodney W. Grimes {
1586e6b3f7cSQing Li 	struct ifnet *ifp;
1596e6b3f7cSQing Li 	struct llentry   *lle = (struct llentry *)arg;
160df8bae1dSRodney W. Grimes 
1616e6b3f7cSQing Li 	if (lle == NULL) {
1626e6b3f7cSQing Li 		panic("%s: NULL entry!\n", __func__);
163df8bae1dSRodney W. Grimes 		return;
1646e6b3f7cSQing Li 	}
1656e6b3f7cSQing Li 	ifp = lle->lle_tbl->llt_ifp;
1666e6b3f7cSQing Li 	IF_AFDATA_LOCK(ifp);
1676e6b3f7cSQing Li 	LLE_WLOCK(lle);
1685e96c0a1SKip Macy 	if (((lle->la_flags & LLE_DELETED)
1695e96c0a1SKip Macy 		|| (time_second >= lle->la_expire))
1705e96c0a1SKip Macy 	    && (!callout_pending(&lle->la_timer) &&
1715e96c0a1SKip Macy 		callout_active(&lle->la_timer)))
1726e6b3f7cSQing Li 		(void) llentry_free(lle);
1735e96c0a1SKip Macy 	else {
174df8bae1dSRodney W. Grimes 		/*
1756e6b3f7cSQing Li 		 * Still valid, just drop our reference
176df8bae1dSRodney W. Grimes 		 */
1776e6b3f7cSQing Li 		LLE_FREE_LOCKED(lle);
178df8bae1dSRodney W. Grimes 	}
1796e6b3f7cSQing Li 	IF_AFDATA_UNLOCK(ifp);
180df8bae1dSRodney W. Grimes }
181df8bae1dSRodney W. Grimes 
182df8bae1dSRodney W. Grimes /*
183df8bae1dSRodney W. Grimes  * Broadcast an ARP request. Caller specifies:
184df8bae1dSRodney W. Grimes  *	- arp header source ip address
185df8bae1dSRodney W. Grimes  *	- arp header target ip address
186df8bae1dSRodney W. Grimes  *	- arp header source ethernet address
187df8bae1dSRodney W. Grimes  */
1886e6b3f7cSQing Li void
189f2565d68SRobert Watson arprequest(struct ifnet *ifp, struct in_addr *sip, struct in_addr  *tip,
190f2565d68SRobert Watson     u_char *enaddr)
191df8bae1dSRodney W. Grimes {
192e952fa39SMatthew N. Dodd 	struct mbuf *m;
193e952fa39SMatthew N. Dodd 	struct arphdr *ah;
194df8bae1dSRodney W. Grimes 	struct sockaddr sa;
195df8bae1dSRodney W. Grimes 
1966e6b3f7cSQing Li 	if (sip == NULL) {
1976e6b3f7cSQing Li 		/* XXX don't believe this can happen (or explain why) */
1986e6b3f7cSQing Li 		/*
1996e6b3f7cSQing Li 		 * The caller did not supply a source address, try to find
2006e6b3f7cSQing Li 		 * a compatible one among those assigned to this interface.
2016e6b3f7cSQing Li 		 */
2026e6b3f7cSQing Li 		struct ifaddr *ifa;
2036e6b3f7cSQing Li 
2046e6b3f7cSQing Li 		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
2056e6b3f7cSQing Li 			if (!ifa->ifa_addr ||
2066e6b3f7cSQing Li 			    ifa->ifa_addr->sa_family != AF_INET)
2076e6b3f7cSQing Li 				continue;
2086e6b3f7cSQing Li 			sip = &SIN(ifa->ifa_addr)->sin_addr;
2096e6b3f7cSQing Li 			if (0 == ((sip->s_addr ^ tip->s_addr) &
2106e6b3f7cSQing Li 			    SIN(ifa->ifa_netmask)->sin_addr.s_addr) )
2116e6b3f7cSQing Li 				break;  /* found it. */
2126e6b3f7cSQing Li 		}
2136e6b3f7cSQing Li 		if (sip == NULL) {
2146e6b3f7cSQing Li 			printf("%s: cannot find matching address\n", __func__);
2156e6b3f7cSQing Li 			return;
2166e6b3f7cSQing Li 		}
2176e6b3f7cSQing Li 	}
2186e6b3f7cSQing Li 
219a163d034SWarner Losh 	if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
220df8bae1dSRodney W. Grimes 		return;
22164bf80ceSMatthew N. Dodd 	m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) +
22264bf80ceSMatthew N. Dodd 		2*ifp->if_data.ifi_addrlen;
22364bf80ceSMatthew N. Dodd 	m->m_pkthdr.len = m->m_len;
22464bf80ceSMatthew N. Dodd 	MH_ALIGN(m, m->m_len);
22564bf80ceSMatthew N. Dodd 	ah = mtod(m, struct arphdr *);
22664bf80ceSMatthew N. Dodd 	bzero((caddr_t)ah, m->m_len);
22719527d3eSRobert Watson #ifdef MAC
228b9b0dac3SRobert Watson 	mac_netinet_arp_send(ifp, m);
22919527d3eSRobert Watson #endif
230322dcb8dSMax Khon 	ah->ar_pro = htons(ETHERTYPE_IP);
231322dcb8dSMax Khon 	ah->ar_hln = ifp->if_addrlen;		/* hardware address length */
232322dcb8dSMax Khon 	ah->ar_pln = sizeof(struct in_addr);	/* protocol address length */
233322dcb8dSMax Khon 	ah->ar_op = htons(ARPOP_REQUEST);
23464bf80ceSMatthew N. Dodd 	bcopy((caddr_t)enaddr, (caddr_t)ar_sha(ah), ah->ar_hln);
23564bf80ceSMatthew N. Dodd 	bcopy((caddr_t)sip, (caddr_t)ar_spa(ah), ah->ar_pln);
23664bf80ceSMatthew N. Dodd 	bcopy((caddr_t)tip, (caddr_t)ar_tpa(ah), ah->ar_pln);
23764bf80ceSMatthew N. Dodd 	sa.sa_family = AF_ARP;
23864bf80ceSMatthew N. Dodd 	sa.sa_len = 2;
23964bf80ceSMatthew N. Dodd 	m->m_flags |= M_BCAST;
240279aa3d4SKip Macy 	(*ifp->if_output)(ifp, m, &sa, NULL);
241df8bae1dSRodney W. Grimes }
242df8bae1dSRodney W. Grimes 
243df8bae1dSRodney W. Grimes /*
244cd46a114SLuigi Rizzo  * Resolve an IP address into an ethernet address.
245cd46a114SLuigi Rizzo  * On input:
246cd46a114SLuigi Rizzo  *    ifp is the interface we use
247cd46a114SLuigi Rizzo  *    rt0 is the route to the final destination (possibly useless)
248b6ae6984SJulian Elischer  *    m is the mbuf. May be NULL if we don't have a packet.
249b6ae6984SJulian Elischer  *    dst is the next hop,
250cd46a114SLuigi Rizzo  *    desten is where we want the address.
251cd46a114SLuigi Rizzo  *
252cd46a114SLuigi Rizzo  * On success, desten is filled in and the function returns 0;
253cd46a114SLuigi Rizzo  * If the packet must be held pending resolution, we return EWOULDBLOCK
254cd46a114SLuigi Rizzo  * On other errors, we return the corresponding error code.
255b6ae6984SJulian Elischer  * Note that m_freem() handles NULL.
256df8bae1dSRodney W. Grimes  */
257df8bae1dSRodney W. Grimes int
258cd46a114SLuigi Rizzo arpresolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m,
2596e6b3f7cSQing Li 	struct sockaddr *dst, u_char *desten, struct llentry **lle)
260df8bae1dSRodney W. Grimes {
2616e6b3f7cSQing Li 	struct llentry *la = 0;
26200a46b31SKip Macy 	u_int flags = 0;
2636e6b3f7cSQing Li 	int error, renew;
264df8bae1dSRodney W. Grimes 
2656e6b3f7cSQing Li 	*lle = NULL;
2666e6b3f7cSQing Li 	if (m != NULL) {
267b6ae6984SJulian Elischer 		if (m->m_flags & M_BCAST) {
268b6ae6984SJulian Elischer 			/* broadcast */
269b6ae6984SJulian Elischer 			(void)memcpy(desten,
270b6ae6984SJulian Elischer 			    ifp->if_broadcastaddr, ifp->if_addrlen);
271cd46a114SLuigi Rizzo 			return (0);
272df8bae1dSRodney W. Grimes 		}
273b6ae6984SJulian Elischer 		if (m->m_flags & M_MCAST && ifp->if_type != IFT_ARCNET) {
274b6ae6984SJulian Elischer 			/* multicast */
275df8bae1dSRodney W. Grimes 			ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten);
276cd46a114SLuigi Rizzo 			return (0);
277df8bae1dSRodney W. Grimes 		}
278b6ae6984SJulian Elischer 	}
2796e6b3f7cSQing Li 	/* XXXXX
28093fcb5a2SJulian Elischer 	 */
2816e6b3f7cSQing Li retry:
28200a46b31SKip Macy 	IF_AFDATA_RLOCK(ifp);
2836e6b3f7cSQing Li 	la = lla_lookup(LLTABLE(ifp), flags, dst);
28400a46b31SKip Macy 	IF_AFDATA_RUNLOCK(ifp);
28500a46b31SKip Macy 	if ((la == NULL) && ((flags & LLE_EXCLUSIVE) == 0)
28600a46b31SKip Macy 	    && ((ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) == 0)) {
28700a46b31SKip Macy 		flags |= (LLE_CREATE | LLE_EXCLUSIVE);
28800a46b31SKip Macy 		IF_AFDATA_WLOCK(ifp);
28900a46b31SKip Macy 		la = lla_lookup(LLTABLE(ifp), flags, dst);
29000a46b31SKip Macy 		IF_AFDATA_WUNLOCK(ifp);
29100a46b31SKip Macy 	}
2921ed7bf1eSGleb Smirnoff 	if (la == NULL) {
2936e6b3f7cSQing Li 		if (flags & LLE_CREATE)
2941ed7bf1eSGleb Smirnoff 			log(LOG_DEBUG,
2951ed7bf1eSGleb Smirnoff 			    "arpresolve: can't allocate llinfo for %s\n",
2961ed7bf1eSGleb Smirnoff 			    inet_ntoa(SIN(dst)->sin_addr));
2971ed7bf1eSGleb Smirnoff 		m_freem(m);
2986e6b3f7cSQing Li 		return (EINVAL);
2991ed7bf1eSGleb Smirnoff 	}
300a20e2538SGleb Smirnoff 
3016e6b3f7cSQing Li 	if ((la->la_flags & LLE_VALID) &&
3026e6b3f7cSQing Li 	    ((la->la_flags & LLE_STATIC) || la->la_expire > time_uptime)) {
3036e6b3f7cSQing Li 		bcopy(&la->ll_addr, desten, ifp->if_addrlen);
304f0f3379eSOrion Hodson 		/*
305f0f3379eSOrion Hodson 		 * If entry has an expiry time and it is approaching,
3066e6b3f7cSQing Li 		 * see if we need to send an ARP request within this
3076e6b3f7cSQing Li 		 * arpt_down interval.
308f0f3379eSOrion Hodson 		 */
3096e6b3f7cSQing Li 		if (!(la->la_flags & LLE_STATIC) &&
3106e6b3f7cSQing Li 		    time_uptime + la->la_preempt > la->la_expire) {
3116e6b3f7cSQing Li 			arprequest(ifp, NULL,
3126e6b3f7cSQing Li 			    &SIN(dst)->sin_addr, IF_LLADDR(ifp));
313a20e2538SGleb Smirnoff 
314022695f8SOrion Hodson 			la->la_preempt--;
315f0f3379eSOrion Hodson 		}
316f0f3379eSOrion Hodson 
3176e6b3f7cSQing Li 		*lle = la;
3186e6b3f7cSQing Li 		error = 0;
3196e6b3f7cSQing Li 		goto done;
320df8bae1dSRodney W. Grimes 	}
3216e6b3f7cSQing Li 
3226e6b3f7cSQing Li 	if (la->la_flags & LLE_STATIC) {   /* should not happen! */
3236e6b3f7cSQing Li 		log(LOG_DEBUG, "arpresolve: ouch, empty static llinfo for %s\n",
3246e6b3f7cSQing Li 		    inet_ntoa(SIN(dst)->sin_addr));
32547891de1SRuslan Ermilov 		m_freem(m);
3266e6b3f7cSQing Li 		error = EINVAL;
3276e6b3f7cSQing Li 		goto done;
3286e6b3f7cSQing Li 	}
3296e6b3f7cSQing Li 
3306e6b3f7cSQing Li 	renew = (la->la_asked == 0 || la->la_expire != time_uptime);
3316e6b3f7cSQing Li 	if ((renew || m != NULL) && (flags & LLE_EXCLUSIVE) == 0) {
3326e6b3f7cSQing Li 		flags |= LLE_EXCLUSIVE;
3336e6b3f7cSQing Li 		LLE_RUNLOCK(la);
3346e6b3f7cSQing Li 		goto retry;
33547891de1SRuslan Ermilov 	}
33608aadfbbSJonathan Lemon 	/*
337df8bae1dSRodney W. Grimes 	 * There is an arptab entry, but no ethernet address
338df8bae1dSRodney W. Grimes 	 * response yet.  Replace the held mbuf with this
339df8bae1dSRodney W. Grimes 	 * latest one.
340df8bae1dSRodney W. Grimes 	 */
3416e6b3f7cSQing Li 	if (m != NULL) {
3426e6b3f7cSQing Li 		if (la->la_hold != NULL)
343df8bae1dSRodney W. Grimes 			m_freem(la->la_hold);
344df8bae1dSRodney W. Grimes 		la->la_hold = m;
3456e6b3f7cSQing Li 		if (renew == 0 && (flags & LLE_EXCLUSIVE)) {
3466e6b3f7cSQing Li 			flags &= ~LLE_EXCLUSIVE;
3476e6b3f7cSQing Li 			LLE_DOWNGRADE(la);
34858505389SKip Macy 		}
349e1ff74c5SGleb Smirnoff 
3506e6b3f7cSQing Li 	}
351e1ff74c5SGleb Smirnoff 	/*
352e1ff74c5SGleb Smirnoff 	 * Return EWOULDBLOCK if we have tried less than arp_maxtries. It
353e1ff74c5SGleb Smirnoff 	 * will be masked by ether_output(). Return EHOSTDOWN/EHOSTUNREACH
354e1ff74c5SGleb Smirnoff 	 * if we have already sent arp_maxtries ARP requests. Retransmit the
355e1ff74c5SGleb Smirnoff 	 * ARP request, but not faster than one request per second.
356e1ff74c5SGleb Smirnoff 	 */
357603724d3SBjoern A. Zeeb 	if (la->la_asked < V_arp_maxtries)
358e1ff74c5SGleb Smirnoff 		error = EWOULDBLOCK;	/* First request. */
359e1ff74c5SGleb Smirnoff 	else
3606e6b3f7cSQing Li 		error =
3616e6b3f7cSQing Li 		    (rt0->rt_flags & RTF_GATEWAY) ? EHOSTDOWN : EHOSTUNREACH;
362e1ff74c5SGleb Smirnoff 
3636e6b3f7cSQing Li 	if (renew) {
3646e6b3f7cSQing Li 		LLE_ADDREF(la);
3656e6b3f7cSQing Li 		la->la_expire = time_uptime;
3666e6b3f7cSQing Li 		callout_reset(&la->la_timer, hz, arptimer, la);
36795ebcabeSMaxim Konovalov 		la->la_asked++;
3686e6b3f7cSQing Li 		LLE_WUNLOCK(la);
3696e6b3f7cSQing Li 		arprequest(ifp, NULL, &SIN(dst)->sin_addr,
370322dcb8dSMax Khon 		    IF_LLADDR(ifp));
3716e6b3f7cSQing Li 		return (error);
3726e6b3f7cSQing Li 	}
3736e6b3f7cSQing Li done:
3746e6b3f7cSQing Li 	if (flags & LLE_EXCLUSIVE)
3756e6b3f7cSQing Li 		LLE_WUNLOCK(la);
3766e6b3f7cSQing Li 	else
3776e6b3f7cSQing Li 		LLE_RUNLOCK(la);
378e1ff74c5SGleb Smirnoff 	return (error);
379df8bae1dSRodney W. Grimes }
380df8bae1dSRodney W. Grimes 
381df8bae1dSRodney W. Grimes /*
382df8bae1dSRodney W. Grimes  * Common length and type checks are done here,
383df8bae1dSRodney W. Grimes  * then the protocol-specific routine is called.
384df8bae1dSRodney W. Grimes  */
385885f1aa4SPoul-Henning Kamp static void
3861cafed39SJonathan Lemon arpintr(struct mbuf *m)
387df8bae1dSRodney W. Grimes {
3881cafed39SJonathan Lemon 	struct arphdr *ar;
389df8bae1dSRodney W. Grimes 
39076ec7b2fSRobert Watson 	if (m->m_len < sizeof(struct arphdr) &&
39184365e2bSMatthew Dillon 	    ((m = m_pullup(m, sizeof(struct arphdr))) == NULL)) {
392e44d6283SJoerg Wunsch 		log(LOG_ERR, "arp: runt packet -- m_pullup failed\n");
3931cafed39SJonathan Lemon 		return;
39476ec7b2fSRobert Watson 	}
39576ec7b2fSRobert Watson 	ar = mtod(m, struct arphdr *);
39676ec7b2fSRobert Watson 
3971cafed39SJonathan Lemon 	if (ntohs(ar->ar_hrd) != ARPHRD_ETHER &&
3981cafed39SJonathan Lemon 	    ntohs(ar->ar_hrd) != ARPHRD_IEEE802 &&
399b8b33234SDoug Rabson 	    ntohs(ar->ar_hrd) != ARPHRD_ARCNET &&
400b8b33234SDoug Rabson 	    ntohs(ar->ar_hrd) != ARPHRD_IEEE1394) {
4011cafed39SJonathan Lemon 		log(LOG_ERR, "arp: unknown hardware address format (0x%2D)\n",
40276ec7b2fSRobert Watson 		    (unsigned char *)&ar->ar_hrd, "");
40376ec7b2fSRobert Watson 		m_freem(m);
4041cafed39SJonathan Lemon 		return;
40576ec7b2fSRobert Watson 	}
40676ec7b2fSRobert Watson 
40731175791SRuslan Ermilov 	if (m->m_len < arphdr_len(ar)) {
40878e2d2bdSRuslan Ermilov 		if ((m = m_pullup(m, arphdr_len(ar))) == NULL) {
409f72d9d83SJoerg Wunsch 			log(LOG_ERR, "arp: runt packet\n");
41076ec7b2fSRobert Watson 			m_freem(m);
4111cafed39SJonathan Lemon 			return;
41276ec7b2fSRobert Watson 		}
41378e2d2bdSRuslan Ermilov 		ar = mtod(m, struct arphdr *);
41478e2d2bdSRuslan Ermilov 	}
415df8bae1dSRodney W. Grimes 
416df8bae1dSRodney W. Grimes 	switch (ntohs(ar->ar_pro)) {
4171d5e9e22SEivind Eklund #ifdef INET
418df8bae1dSRodney W. Grimes 	case ETHERTYPE_IP:
419df8bae1dSRodney W. Grimes 		in_arpinput(m);
4201cafed39SJonathan Lemon 		return;
4211d5e9e22SEivind Eklund #endif
422df8bae1dSRodney W. Grimes 	}
423df8bae1dSRodney W. Grimes 	m_freem(m);
424df8bae1dSRodney W. Grimes }
425df8bae1dSRodney W. Grimes 
4261d5e9e22SEivind Eklund #ifdef INET
427df8bae1dSRodney W. Grimes /*
428df8bae1dSRodney W. Grimes  * ARP for Internet protocols on 10 Mb/s Ethernet.
429df8bae1dSRodney W. Grimes  * Algorithm is that given in RFC 826.
430df8bae1dSRodney W. Grimes  * In addition, a sanity check is performed on the sender
431df8bae1dSRodney W. Grimes  * protocol address, to catch impersonators.
432df8bae1dSRodney W. Grimes  * We no longer handle negotiations for use of trailer protocol:
433df8bae1dSRodney W. Grimes  * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent
434df8bae1dSRodney W. Grimes  * along with IP replies if we wanted trailers sent to us,
435df8bae1dSRodney W. Grimes  * and also sent them in response to IP replies.
436df8bae1dSRodney W. Grimes  * This allowed either end to announce the desire to receive
437df8bae1dSRodney W. Grimes  * trailer packets.
438df8bae1dSRodney W. Grimes  * We no longer reply to requests for ETHERTYPE_TRAIL protocol either,
439df8bae1dSRodney W. Grimes  * but formerly didn't normally send requests.
440df8bae1dSRodney W. Grimes  */
4413269187dSAlfred Perlstein static int log_arp_wrong_iface = 1;
442e3d123d6SAlfred Perlstein static int log_arp_movements = 1;
44339393906SGleb Smirnoff static int log_arp_permanent_modify = 1;
4443269187dSAlfred Perlstein 
4453269187dSAlfred Perlstein SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW,
4463269187dSAlfred Perlstein 	&log_arp_wrong_iface, 0,
4473269187dSAlfred Perlstein 	"log arp packets arriving on the wrong interface");
448e3d123d6SAlfred Perlstein SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_movements, CTLFLAG_RW,
449e3d123d6SAlfred Perlstein         &log_arp_movements, 0,
45075ce3221SAlfred Perlstein         "log arp replies from MACs different than the one in the cache");
45139393906SGleb Smirnoff SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_permanent_modify, CTLFLAG_RW,
45239393906SGleb Smirnoff         &log_arp_permanent_modify, 0,
45339393906SGleb Smirnoff         "log arp replies from MACs different than the one in the permanent arp entry");
454e3d123d6SAlfred Perlstein 
4553269187dSAlfred Perlstein 
456df8bae1dSRodney W. Grimes static void
457f2565d68SRobert Watson in_arpinput(struct mbuf *m)
458df8bae1dSRodney W. Grimes {
459e952fa39SMatthew N. Dodd 	struct arphdr *ah;
460e952fa39SMatthew N. Dodd 	struct ifnet *ifp = m->m_pkthdr.rcvif;
4616e6b3f7cSQing Li 	struct llentry *la = NULL;
462e952fa39SMatthew N. Dodd 	struct rtentry *rt;
463ca925d9cSJonathan Lemon 	struct ifaddr *ifa;
464ca925d9cSJonathan Lemon 	struct in_ifaddr *ia;
465df8bae1dSRodney W. Grimes 	struct sockaddr sa;
466df8bae1dSRodney W. Grimes 	struct in_addr isaddr, itaddr, myaddr;
467a9771948SGleb Smirnoff 	u_int8_t *enaddr = NULL;
4686e6b3f7cSQing Li 	int op, flags;
4696e6b3f7cSQing Li 	struct mbuf *m0;
470322dcb8dSMax Khon 	int req_len;
47180b11ee4SPhilip Paeps 	int bridged = 0, is_bridge = 0;
472422a115aSGleb Smirnoff #ifdef DEV_CARP
4732ef4a436SGleb Smirnoff 	int carp_match = 0;
474422a115aSGleb Smirnoff #endif
4758e7e854cSKip Macy 	struct sockaddr_in sin;
4768e7e854cSKip Macy 	sin.sin_len = sizeof(struct sockaddr_in);
4778e7e854cSKip Macy 	sin.sin_family = AF_INET;
47829910a5aSKip Macy 	sin.sin_addr.s_addr = 0;
479df8bae1dSRodney W. Grimes 
48074948aa6SAndrew Thompson 	if (ifp->if_bridge)
4818f867517SAndrew Thompson 		bridged = 1;
48280b11ee4SPhilip Paeps 	if (ifp->if_type == IFT_BRIDGE)
48380b11ee4SPhilip Paeps 		is_bridge = 1;
4848f867517SAndrew Thompson 
485322dcb8dSMax Khon 	req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
486322dcb8dSMax Khon 	if (m->m_len < req_len && (m = m_pullup(m, req_len)) == NULL) {
4874cbc8ad1SYaroslav Tykhiy 		log(LOG_ERR, "in_arp: runt packet -- m_pullup failed\n");
4884cbc8ad1SYaroslav Tykhiy 		return;
4894cbc8ad1SYaroslav Tykhiy 	}
4904cbc8ad1SYaroslav Tykhiy 
491322dcb8dSMax Khon 	ah = mtod(m, struct arphdr *);
492322dcb8dSMax Khon 	op = ntohs(ah->ar_op);
493322dcb8dSMax Khon 	(void)memcpy(&isaddr, ar_spa(ah), sizeof (isaddr));
494322dcb8dSMax Khon 	(void)memcpy(&itaddr, ar_tpa(ah), sizeof (itaddr));
49532439868SGleb Smirnoff 
496ca925d9cSJonathan Lemon 	/*
497ca925d9cSJonathan Lemon 	 * For a bridge, we want to check the address irrespective
498ca925d9cSJonathan Lemon 	 * of the receive interface. (This will change slightly
499ca925d9cSJonathan Lemon 	 * when we have clusters of interfaces).
500a9771948SGleb Smirnoff 	 * If the interface does not match, but the recieving interface
501a9771948SGleb Smirnoff 	 * is part of carp, we call carp_iamatch to see if this is a
502a9771948SGleb Smirnoff 	 * request for the virtual host ip.
503a9771948SGleb Smirnoff 	 * XXX: This is really ugly!
504ca925d9cSJonathan Lemon 	 */
5052d9cfabaSRobert Watson 	IN_IFADDR_RLOCK();
5062ef4a436SGleb Smirnoff 	LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) {
5077f2d8767SAndrew Thompson 		if (((bridged && ia->ia_ifp->if_bridge != NULL) ||
5086e6b3f7cSQing Li 		    ia->ia_ifp == ifp) &&
50909d54778SRobert Watson 		    itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {
51009d54778SRobert Watson 			ifa_ref(&ia->ia_ifa);
5112d9cfabaSRobert Watson 			IN_IFADDR_RUNLOCK();
512ca925d9cSJonathan Lemon 			goto match;
51309d54778SRobert Watson 		}
5142ef4a436SGleb Smirnoff #ifdef DEV_CARP
5152ef4a436SGleb Smirnoff 		if (ifp->if_carp != NULL &&
5162ef4a436SGleb Smirnoff 		    carp_iamatch(ifp->if_carp, ia, &isaddr, &enaddr) &&
5172ef4a436SGleb Smirnoff 		    itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {
5182ef4a436SGleb Smirnoff 			carp_match = 1;
51909d54778SRobert Watson 			ifa_ref(&ia->ia_ifa);
5202d9cfabaSRobert Watson 			IN_IFADDR_RUNLOCK();
5212ef4a436SGleb Smirnoff 			goto match;
5222ef4a436SGleb Smirnoff 		}
5232ef4a436SGleb Smirnoff #endif
5242ef4a436SGleb Smirnoff 	}
525ca925d9cSJonathan Lemon 	LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash)
5267f2d8767SAndrew Thompson 		if (((bridged && ia->ia_ifp->if_bridge != NULL) ||
5276e6b3f7cSQing Li 		    ia->ia_ifp == ifp) &&
52809d54778SRobert Watson 		    isaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {
52909d54778SRobert Watson 			ifa_ref(&ia->ia_ifa);
5302d9cfabaSRobert Watson 			IN_IFADDR_RUNLOCK();
531ca925d9cSJonathan Lemon 			goto match;
53209d54778SRobert Watson 		}
53380b11ee4SPhilip Paeps 
53480b11ee4SPhilip Paeps #define BDG_MEMBER_MATCHES_ARP(addr, ifp, ia)				\
53580b11ee4SPhilip Paeps   (ia->ia_ifp->if_bridge == ifp->if_softc &&				\
53680b11ee4SPhilip Paeps   !bcmp(IF_LLADDR(ia->ia_ifp), IF_LLADDR(ifp), ifp->if_addrlen) &&	\
53780b11ee4SPhilip Paeps   addr == ia->ia_addr.sin_addr.s_addr)
53880b11ee4SPhilip Paeps 	/*
53980b11ee4SPhilip Paeps 	 * Check the case when bridge shares its MAC address with
54080b11ee4SPhilip Paeps 	 * some of its children, so packets are claimed by bridge
54180b11ee4SPhilip Paeps 	 * itself (bridge_input() does it first), but they are really
54280b11ee4SPhilip Paeps 	 * meant to be destined to the bridge member.
54380b11ee4SPhilip Paeps 	 */
54480b11ee4SPhilip Paeps 	if (is_bridge) {
54580b11ee4SPhilip Paeps 		LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) {
54680b11ee4SPhilip Paeps 			if (BDG_MEMBER_MATCHES_ARP(itaddr.s_addr, ifp, ia)) {
54709d54778SRobert Watson 				ifa_ref(&ia->ia_ifa);
54880b11ee4SPhilip Paeps 				ifp = ia->ia_ifp;
5492d9cfabaSRobert Watson 				IN_IFADDR_RUNLOCK();
55080b11ee4SPhilip Paeps 				goto match;
55180b11ee4SPhilip Paeps 			}
55280b11ee4SPhilip Paeps 		}
55380b11ee4SPhilip Paeps 	}
55480b11ee4SPhilip Paeps #undef BDG_MEMBER_MATCHES_ARP
5552d9cfabaSRobert Watson 	IN_IFADDR_RUNLOCK();
55680b11ee4SPhilip Paeps 
557ca925d9cSJonathan Lemon 	/*
558d8b84d9eSJonathan Lemon 	 * No match, use the first inet address on the receive interface
559ca925d9cSJonathan Lemon 	 * as a dummy address for the rest of the function.
560ca925d9cSJonathan Lemon 	 */
56109d54778SRobert Watson 	IF_ADDR_LOCK(ifp);
562d8b84d9eSJonathan Lemon 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
5634b97d7afSYaroslav Tykhiy 		if (ifa->ifa_addr->sa_family == AF_INET) {
564ec691a10SJonathan Lemon 			ia = ifatoia(ifa);
56509d54778SRobert Watson 			ifa_ref(ifa);
566f8574c7aSRobert Watson 			IF_ADDR_UNLOCK(ifp);
567ec691a10SJonathan Lemon 			goto match;
568ec691a10SJonathan Lemon 		}
56909d54778SRobert Watson 	IF_ADDR_UNLOCK(ifp);
57009d54778SRobert Watson 
571ec691a10SJonathan Lemon 	/*
572ec691a10SJonathan Lemon 	 * If bridging, fall back to using any inet address.
573ec691a10SJonathan Lemon 	 */
5742d9cfabaSRobert Watson 	IN_IFADDR_RLOCK();
5752d9cfabaSRobert Watson 	if (!bridged || (ia = TAILQ_FIRST(&V_in_ifaddrhead)) == NULL) {
5762d9cfabaSRobert Watson 		IN_IFADDR_RUNLOCK();
577b2a8ac7cSLuigi Rizzo 		goto drop;
5782d9cfabaSRobert Watson 	}
57909d54778SRobert Watson 	ifa_ref(&ia->ia_ifa);
5802d9cfabaSRobert Watson 	IN_IFADDR_RUNLOCK();
581ca925d9cSJonathan Lemon match:
582a9771948SGleb Smirnoff 	if (!enaddr)
583a9771948SGleb Smirnoff 		enaddr = (u_int8_t *)IF_LLADDR(ifp);
584ca925d9cSJonathan Lemon 	myaddr = ia->ia_addr.sin_addr;
58509d54778SRobert Watson 	ifa_free(&ia->ia_ifa);
586a9771948SGleb Smirnoff 	if (!bcmp(ar_sha(ah), enaddr, ifp->if_addrlen))
587b2a8ac7cSLuigi Rizzo 		goto drop;	/* it's from me, ignore it. */
588322dcb8dSMax Khon 	if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) {
589df8bae1dSRodney W. Grimes 		log(LOG_ERR,
590322dcb8dSMax Khon 		    "arp: link address is broadcast for IP address %s!\n",
591ef0cdf33SGarrett Wollman 		    inet_ntoa(isaddr));
592b2a8ac7cSLuigi Rizzo 		goto drop;
593df8bae1dSRodney W. Grimes 	}
59400fcf9d1SRobert Watson 	/*
59500fcf9d1SRobert Watson 	 * Warn if another host is using the same IP address, but only if the
59600fcf9d1SRobert Watson 	 * IP address isn't 0.0.0.0, which is used for DHCP only, in which
59700fcf9d1SRobert Watson 	 * case we suppress the warning to avoid false positive complaints of
59800fcf9d1SRobert Watson 	 * potential misconfiguration.
59900fcf9d1SRobert Watson 	 */
600f69453caSAndrew Thompson 	if (!bridged && isaddr.s_addr == myaddr.s_addr && myaddr.s_addr != 0) {
601df8bae1dSRodney W. Grimes 		log(LOG_ERR,
6023affb6fbSYaroslav Tykhiy 		   "arp: %*D is using my IP address %s on %s!\n",
603322dcb8dSMax Khon 		   ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
6043affb6fbSYaroslav Tykhiy 		   inet_ntoa(isaddr), ifp->if_xname);
605df8bae1dSRodney W. Grimes 		itaddr = myaddr;
606df8bae1dSRodney W. Grimes 		goto reply;
607df8bae1dSRodney W. Grimes 	}
608deb62e28SRuslan Ermilov 	if (ifp->if_flags & IFF_STATICARP)
609deb62e28SRuslan Ermilov 		goto reply;
6108b07e49aSJulian Elischer 
6116e6b3f7cSQing Li 	bzero(&sin, sizeof(sin));
6126e6b3f7cSQing Li 	sin.sin_len = sizeof(struct sockaddr_in);
6136e6b3f7cSQing Li 	sin.sin_family = AF_INET;
6146e6b3f7cSQing Li 	sin.sin_addr = isaddr;
6156e6b3f7cSQing Li 	flags = (itaddr.s_addr == myaddr.s_addr) ? LLE_CREATE : 0;
6166e6b3f7cSQing Li 	flags |= LLE_EXCLUSIVE;
6176e6b3f7cSQing Li 	IF_AFDATA_LOCK(ifp);
6186e6b3f7cSQing Li 	la = lla_lookup(LLTABLE(ifp), flags, (struct sockaddr *)&sin);
6196e6b3f7cSQing Li 	IF_AFDATA_UNLOCK(ifp);
6206e6b3f7cSQing Li 	if (la != NULL) {
6216e6b3f7cSQing Li 		/* the following is not an error when doing bridging */
6226e6b3f7cSQing Li 		if (!bridged && la->lle_tbl->llt_ifp != ifp
623422a115aSGleb Smirnoff #ifdef DEV_CARP
624422a115aSGleb Smirnoff 		    && (ifp->if_type != IFT_CARP || !carp_match)
625422a115aSGleb Smirnoff #endif
626422a115aSGleb Smirnoff 			) {
6273269187dSAlfred Perlstein 			if (log_arp_wrong_iface)
6288b07e49aSJulian Elischer 				log(LOG_ERR, "arp: %s is on %s "
6296e6b3f7cSQing Li 				    "but got reply from %*D on %s\n",
630dd9b6ddeSBill Fenner 				    inet_ntoa(isaddr),
6316e6b3f7cSQing Li 				    la->lle_tbl->llt_ifp->if_xname,
6326e6b3f7cSQing Li 				    ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
6339bf40edeSBrooks Davis 				    ifp->if_xname);
6346e6b3f7cSQing Li 			goto reply;
635dd9b6ddeSBill Fenner 		}
6366e6b3f7cSQing Li 		if ((la->la_flags & LLE_VALID) &&
6376e6b3f7cSQing Li 		    bcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) {
6386e6b3f7cSQing Li 			if (la->la_flags & LLE_STATIC) {
6398b07e49aSJulian Elischer 				log(LOG_ERR,
6406e6b3f7cSQing Li 				    "arp: %*D attempts to modify permanent "
6416e6b3f7cSQing Li 				    "entry for %s on %s\n",
6426e6b3f7cSQing Li 				    ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
6436e6b3f7cSQing Li 				    inet_ntoa(isaddr), ifp->if_xname);
6446e6b3f7cSQing Li 				goto reply;
6456e6b3f7cSQing Li 			}
6466e6b3f7cSQing Li 			if (log_arp_movements) {
6476e6b3f7cSQing Li 			        log(LOG_INFO, "arp: %s moved from %*D "
6486e6b3f7cSQing Li 				    "to %*D on %s\n",
6498b07e49aSJulian Elischer 				    inet_ntoa(isaddr),
6506e6b3f7cSQing Li 				    ifp->if_addrlen,
6516e6b3f7cSQing Li 				    (u_char *)&la->ll_addr, ":",
6526e6b3f7cSQing Li 				    ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
6538b07e49aSJulian Elischer 				    ifp->if_xname);
654dd9b6ddeSBill Fenner 			}
655dfd5dee1SPeter Wemm 		}
6566e6b3f7cSQing Li 
657322dcb8dSMax Khon 		if (ifp->if_addrlen != ah->ar_hln) {
658322dcb8dSMax Khon 			log(LOG_WARNING,
6596e6b3f7cSQing Li 			    "arp from %*D: addr len: new %d, i/f %d (ignored)",
6606e6b3f7cSQing Li 			    ifp->if_addrlen, (u_char *) ar_sha(ah), ":",
6616e6b3f7cSQing Li 			    ah->ar_hln, ifp->if_addrlen);
6626e6b3f7cSQing Li 			goto reply;
663322dcb8dSMax Khon 		}
6646e6b3f7cSQing Li 		(void)memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen);
6656e6b3f7cSQing Li 		la->la_flags |= LLE_VALID;
6668b07e49aSJulian Elischer 
6676e6b3f7cSQing Li 		if (!(la->la_flags & LLE_STATIC)) {
6686e6b3f7cSQing Li 			la->la_expire = time_uptime + V_arpt_keep;
669603724d3SBjoern A. Zeeb 			callout_reset(&la->la_timer, hz * V_arpt_keep,
6706e6b3f7cSQing Li 			    arptimer, la);
6711daaa65dSGleb Smirnoff 		}
672022695f8SOrion Hodson 		la->la_asked = 0;
673603724d3SBjoern A. Zeeb 		la->la_preempt = V_arp_maxtries;
6746e6b3f7cSQing Li 		if (la->la_hold != NULL) {
6756e6b3f7cSQing Li 			m0 = la->la_hold;
6766e6b3f7cSQing Li 			la->la_hold = 0;
6776e6b3f7cSQing Li 			memcpy(&sa, L3_ADDR(la), sizeof(sa));
6786e6b3f7cSQing Li 			LLE_WUNLOCK(la);
6798b07e49aSJulian Elischer 
6806e6b3f7cSQing Li 			(*ifp->if_output)(ifp, m0, &sa, NULL);
6816e6b3f7cSQing Li 			return;
6826e6b3f7cSQing Li 		}
6836e6b3f7cSQing Li 	}
6846e6b3f7cSQing Li reply:
685b2a8ac7cSLuigi Rizzo 	if (op != ARPOP_REQUEST)
686b2a8ac7cSLuigi Rizzo 		goto drop;
6876e6b3f7cSQing Li 
688df8bae1dSRodney W. Grimes 	if (itaddr.s_addr == myaddr.s_addr) {
6898b07e49aSJulian Elischer 		/* Shortcut.. the receiving interface is the target. */
690322dcb8dSMax Khon 		(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
691a9771948SGleb Smirnoff 		(void)memcpy(ar_sha(ah), enaddr, ah->ar_hln);
692df8bae1dSRodney W. Grimes 	} else {
693897d75c9SQing Li 		struct llentry *lle = NULL;
694897d75c9SQing Li 
695603724d3SBjoern A. Zeeb 		if (!V_arp_proxyall)
696b2a8ac7cSLuigi Rizzo 			goto drop;
69728e82295SGarrett Wollman 
69828e82295SGarrett Wollman 		sin.sin_addr = itaddr;
6998b07e49aSJulian Elischer 		/* XXX MRT use table 0 for arp reply  */
7008b07e49aSJulian Elischer 		rt = in_rtalloc1((struct sockaddr *)&sin, 0, 0UL, 0);
701b2a8ac7cSLuigi Rizzo 		if (!rt)
702b2a8ac7cSLuigi Rizzo 			goto drop;
703897d75c9SQing Li 
70428e82295SGarrett Wollman 		/*
70528e82295SGarrett Wollman 		 * Don't send proxies for nodes on the same interface
70628e82295SGarrett Wollman 		 * as this one came out of, or we'll get into a fight
70728e82295SGarrett Wollman 		 * over who claims what Ether address.
70828e82295SGarrett Wollman 		 */
709897d75c9SQing Li 		if (!rt->rt_ifp || rt->rt_ifp == ifp) {
7104e57bc33SChristian S.J. Peron 			RTFREE_LOCKED(rt);
711b2a8ac7cSLuigi Rizzo 			goto drop;
71228e82295SGarrett Wollman 		}
713897d75c9SQing Li 		IF_AFDATA_LOCK(rt->rt_ifp);
714897d75c9SQing Li 		lle = lla_lookup(LLTABLE(rt->rt_ifp), 0, (struct sockaddr *)&sin);
715897d75c9SQing Li 		IF_AFDATA_UNLOCK(rt->rt_ifp);
7164e57bc33SChristian S.J. Peron 		RTFREE_LOCKED(rt);
717cc728227SDavid Malone 
718897d75c9SQing Li 		if (lle != NULL) {
719897d75c9SQing Li 			(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
720897d75c9SQing Li 			(void)memcpy(ar_sha(ah), &lle->ll_addr, ah->ar_hln);
721897d75c9SQing Li 			LLE_RUNLOCK(lle);
722897d75c9SQing Li 		} else
723897d75c9SQing Li 			goto drop;
724897d75c9SQing Li 
725cc728227SDavid Malone 		/*
726cc728227SDavid Malone 		 * Also check that the node which sent the ARP packet
727cc728227SDavid Malone 		 * is on the the interface we expect it to be on. This
728cc728227SDavid Malone 		 * avoids ARP chaos if an interface is connected to the
729cc728227SDavid Malone 		 * wrong network.
730cc728227SDavid Malone 		 */
731cc728227SDavid Malone 		sin.sin_addr = isaddr;
732cc728227SDavid Malone 
7338b07e49aSJulian Elischer 		/* XXX MRT use table 0 for arp checks */
7348b07e49aSJulian Elischer 		rt = in_rtalloc1((struct sockaddr *)&sin, 0, 0UL, 0);
735b2a8ac7cSLuigi Rizzo 		if (!rt)
736b2a8ac7cSLuigi Rizzo 			goto drop;
737322dcb8dSMax Khon 		if (rt->rt_ifp != ifp) {
738cc728227SDavid Malone 			log(LOG_INFO, "arp_proxy: ignoring request"
7399bf40edeSBrooks Davis 			    " from %s via %s, expecting %s\n",
7409bf40edeSBrooks Davis 			    inet_ntoa(isaddr), ifp->if_xname,
7419bf40edeSBrooks Davis 			    rt->rt_ifp->if_xname);
7424e57bc33SChristian S.J. Peron 			RTFREE_LOCKED(rt);
743b2a8ac7cSLuigi Rizzo 			goto drop;
744cc728227SDavid Malone 		}
7454e57bc33SChristian S.J. Peron 		RTFREE_LOCKED(rt);
746cc728227SDavid Malone 
747ac234f93SGarrett Wollman #ifdef DEBUG_PROXY
748ac234f93SGarrett Wollman 		printf("arp: proxying for %s\n",
749ef0cdf33SGarrett Wollman 		       inet_ntoa(itaddr));
750ac234f93SGarrett Wollman #endif
751df8bae1dSRodney W. Grimes 	}
752df8bae1dSRodney W. Grimes 
7536e6b3f7cSQing Li 	if (la != NULL)
7546e6b3f7cSQing Li 		LLE_WUNLOCK(la);
755d0558157SBruce M Simpson 	if (itaddr.s_addr == myaddr.s_addr &&
756d0558157SBruce M Simpson 	    IN_LINKLOCAL(ntohl(itaddr.s_addr))) {
757d0558157SBruce M Simpson 		/* RFC 3927 link-local IPv4; always reply by broadcast. */
758d0558157SBruce M Simpson #ifdef DEBUG_LINKLOCAL
759d0558157SBruce M Simpson 		printf("arp: sending reply for link-local addr %s\n",
760d0558157SBruce M Simpson 		    inet_ntoa(itaddr));
761d0558157SBruce M Simpson #endif
762d0558157SBruce M Simpson 		m->m_flags |= M_BCAST;
763d0558157SBruce M Simpson 		m->m_flags &= ~M_MCAST;
764d0558157SBruce M Simpson 	} else {
765d0558157SBruce M Simpson 		/* default behaviour; never reply by broadcast. */
766d0558157SBruce M Simpson 		m->m_flags &= ~(M_BCAST|M_MCAST);
767d0558157SBruce M Simpson 	}
768322dcb8dSMax Khon 	(void)memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln);
769322dcb8dSMax Khon 	(void)memcpy(ar_spa(ah), &itaddr, ah->ar_pln);
770322dcb8dSMax Khon 	ah->ar_op = htons(ARPOP_REPLY);
771322dcb8dSMax Khon 	ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */
77264bf80ceSMatthew N. Dodd 	m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln);
77364bf80ceSMatthew N. Dodd 	m->m_pkthdr.len = m->m_len;
77464bf80ceSMatthew N. Dodd 	sa.sa_family = AF_ARP;
77564bf80ceSMatthew N. Dodd 	sa.sa_len = 2;
776279aa3d4SKip Macy 	(*ifp->if_output)(ifp, m, &sa, NULL);
777df8bae1dSRodney W. Grimes 	return;
778b2a8ac7cSLuigi Rizzo 
779b2a8ac7cSLuigi Rizzo drop:
7806e6b3f7cSQing Li 	if (la != NULL)
7816e6b3f7cSQing Li 		LLE_WUNLOCK(la);
782b2a8ac7cSLuigi Rizzo 	m_freem(m);
783df8bae1dSRodney W. Grimes }
7841d5e9e22SEivind Eklund #endif
785df8bae1dSRodney W. Grimes 
786dd2e4102SGarrett Wollman void
787f2565d68SRobert Watson arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa)
788dd2e4102SGarrett Wollman {
7896e6b3f7cSQing Li 	struct llentry *lle;
7906e6b3f7cSQing Li 
791ce9122fdSQing Li 	if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY) {
792322dcb8dSMax Khon 		arprequest(ifp, &IA_SIN(ifa)->sin_addr,
793322dcb8dSMax Khon 				&IA_SIN(ifa)->sin_addr, IF_LLADDR(ifp));
7946e6b3f7cSQing Li 		/*
7956e6b3f7cSQing Li 		 * interface address is considered static entry
7966e6b3f7cSQing Li 		 * because the output of the arp utility shows
7976e6b3f7cSQing Li 		 * that L2 entry as permanent
7986e6b3f7cSQing Li 		 */
7996e6b3f7cSQing Li 		IF_AFDATA_LOCK(ifp);
8006e6b3f7cSQing Li 		lle = lla_lookup(LLTABLE(ifp), (LLE_CREATE | LLE_IFADDR | LLE_STATIC),
8016e6b3f7cSQing Li 				 (struct sockaddr *)IA_SIN(ifa));
8026e6b3f7cSQing Li 		IF_AFDATA_UNLOCK(ifp);
8036e6b3f7cSQing Li 		if (lle == NULL)
8046e6b3f7cSQing Li 			log(LOG_INFO, "arp_ifinit: cannot create arp "
8056e6b3f7cSQing Li 			    "entry for interface address\n");
80686cd829dSKip Macy 		else
8076e6b3f7cSQing Li 			LLE_RUNLOCK(lle);
808ce9122fdSQing Li 	}
8096e6b3f7cSQing Li 	ifa->ifa_rtrequest = NULL;
810dd2e4102SGarrett Wollman }
811df5e1987SJonathan Lemon 
812a9771948SGleb Smirnoff void
813f2565d68SRobert Watson arp_ifinit2(struct ifnet *ifp, struct ifaddr *ifa, u_char *enaddr)
814a9771948SGleb Smirnoff {
815a9771948SGleb Smirnoff 	if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY)
816a9771948SGleb Smirnoff 		arprequest(ifp, &IA_SIN(ifa)->sin_addr,
817a9771948SGleb Smirnoff 				&IA_SIN(ifa)->sin_addr, enaddr);
8186e6b3f7cSQing Li 	ifa->ifa_rtrequest = NULL;
819a9771948SGleb Smirnoff }
820a9771948SGleb Smirnoff 
8211ed81b73SMarko Zec static void
8221ed81b73SMarko Zec arp_init(void)
8231ed81b73SMarko Zec {
8241ed81b73SMarko Zec 
825d4b5cae4SRobert Watson 	netisr_register(&arp_nh);
826df5e1987SJonathan Lemon }
827df5e1987SJonathan Lemon SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0);
828