2 * Copyright (c) 2004, 2005 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
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14 * documentation and/or other materials provided with the distribution.
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16 * contributors may be used to endorse or promote products derived
17 * from this software without specific, prior written permission.
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38 * modification, are permitted provided that the following conditions
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65 * @(#)if_ether.c 8.1 (Berkeley) 6/10/93
66 * $FreeBSD: src/sys/netinet/if_ether.c,v 1.64.2.23 2003/04/11 07:23:15 fjoe Exp $
67 * $DragonFly: src/sys/netinet/if_ether.c,v 1.43 2007/09/08 12:35:04 sephe Exp $
71 * Ethernet address resolution protocol.
73 * add "inuse/lock" bit (or ref. count) along with valid bit
79 #include <sys/param.h>
80 #include <sys/kernel.h>
81 #include <sys/queue.h>
82 #include <sys/sysctl.h>
83 #include <sys/systm.h>
85 #include <sys/malloc.h>
86 #include <sys/socket.h>
87 #include <sys/syslog.h>
90 #include <net/if_dl.h>
91 #include <net/if_types.h>
92 #include <net/route.h>
93 #include <net/netisr.h>
94 #include <net/if_llc.h>
96 #include <netinet/in.h>
97 #include <netinet/in_var.h>
98 #include <netinet/if_ether.h>
100 #include <sys/thread2.h>
101 #include <sys/msgport2.h>
102 #include <net/netmsg2.h>
106 #include <netinet/ip_carp.h>
109 #define SIN(s) ((struct sockaddr_in *)s)
110 #define SDL(s) ((struct sockaddr_dl *)s)
112 SYSCTL_DECL(_net_link_ether
);
113 SYSCTL_NODE(_net_link_ether
, PF_INET
, inet
, CTLFLAG_RW
, 0, "");
116 static int arpt_prune
= (5*60*1); /* walk list every 5 minutes */
117 static int arpt_keep
= (20*60); /* once resolved, good for 20 more minutes */
118 static int arpt_down
= 20; /* once declared down, don't send for 20 sec */
120 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, prune_intvl
, CTLFLAG_RW
,
122 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, max_age
, CTLFLAG_RW
,
124 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, host_down_time
, CTLFLAG_RW
,
127 #define rt_expire rt_rmx.rmx_expire
130 LIST_ENTRY(llinfo_arp
) la_le
;
131 struct rtentry
*la_rt
;
132 struct mbuf
*la_hold
; /* last packet until resolved/timeout */
133 u_short la_preempt
; /* countdown for pre-expiry arps */
134 u_short la_asked
; /* #times we QUERIED following expiration */
137 static LIST_HEAD(, llinfo_arp
) llinfo_arp_list
[MAXCPU
];
139 static int arp_maxtries
= 5;
140 static int useloopback
= 1; /* use loopback interface for local traffic */
141 static int arp_proxyall
= 0;
143 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, maxtries
, CTLFLAG_RW
,
144 &arp_maxtries
, 0, "");
145 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, useloopback
, CTLFLAG_RW
,
146 &useloopback
, 0, "");
147 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, proxyall
, CTLFLAG_RW
,
148 &arp_proxyall
, 0, "");
150 void arprequest_acces(struct ifnet
*ifp
, struct in_addr
*sip
, struct in_addr
*tip
, u_char
*enaddr
);
151 static void arp_rtrequest (int, struct rtentry
*, struct rt_addrinfo
*);
152 static void arprequest (struct ifnet
*,
153 struct in_addr
*, struct in_addr
*, u_char
*);
154 static void arpintr(struct netmsg
*);
155 static void arptfree (struct llinfo_arp
*);
156 static void arptimer (void *);
157 static struct llinfo_arp
158 *arplookup (in_addr_t addr
, boolean_t create
, boolean_t proxy
);
160 static void in_arpinput (struct mbuf
*);
163 static struct callout arptimer_ch
[MAXCPU
];
166 * Timeout routine. Age arp_tab entries periodically.
170 arptimer(void *ignored_arg
)
172 struct llinfo_arp
*la
, *nla
;
175 LIST_FOREACH_MUTABLE(la
, &llinfo_arp_list
[mycpuid
], la_le
, nla
) {
176 if (la
->la_rt
->rt_expire
&& la
->la_rt
->rt_expire
<= time_second
)
179 callout_reset(&arptimer_ch
[mycpuid
], arpt_prune
* hz
, arptimer
, NULL
);
184 * Parallel to llc_rtrequest.
187 arp_rtrequest(int req
, struct rtentry
*rt
, struct rt_addrinfo
*info
)
189 struct sockaddr
*gate
= rt
->rt_gateway
;
190 struct llinfo_arp
*la
= rt
->rt_llinfo
;
192 struct sockaddr_dl null_sdl
= { sizeof null_sdl
, AF_LINK
};
193 static boolean_t arpinit_done
[MAXCPU
];
195 if (!arpinit_done
[mycpuid
]) {
196 arpinit_done
[mycpuid
] = TRUE
;
197 callout_init(&arptimer_ch
[mycpuid
]);
198 callout_reset(&arptimer_ch
[mycpuid
], hz
, arptimer
, NULL
);
200 if (rt
->rt_flags
& RTF_GATEWAY
)
206 * XXX: If this is a manually added route to interface
207 * such as older version of routed or gated might provide,
208 * restore cloning bit.
210 if (!(rt
->rt_flags
& RTF_HOST
) &&
211 SIN(rt_mask(rt
))->sin_addr
.s_addr
!= 0xffffffff)
212 rt
->rt_flags
|= RTF_CLONING
;
213 if (rt
->rt_flags
& RTF_CLONING
) {
215 * Case 1: This route should come from a route to iface.
217 rt_setgate(rt
, rt_key(rt
),
218 (struct sockaddr
*)&null_sdl
);
219 gate
= rt
->rt_gateway
;
220 SDL(gate
)->sdl_type
= rt
->rt_ifp
->if_type
;
221 SDL(gate
)->sdl_index
= rt
->rt_ifp
->if_index
;
222 rt
->rt_expire
= time_second
;
225 /* Announce a new entry if requested. */
226 if (rt
->rt_flags
& RTF_ANNOUNCE
)
227 arprequest(rt
->rt_ifp
,
228 &SIN(rt_key(rt
))->sin_addr
,
229 &SIN(rt_key(rt
))->sin_addr
,
233 if (gate
->sa_family
!= AF_LINK
||
234 gate
->sa_len
< sizeof(struct sockaddr_dl
)) {
235 log(LOG_DEBUG
, "arp_rtrequest: bad gateway value\n");
238 SDL(gate
)->sdl_type
= rt
->rt_ifp
->if_type
;
239 SDL(gate
)->sdl_index
= rt
->rt_ifp
->if_index
;
241 break; /* This happens on a route change */
243 * Case 2: This route may come from cloning, or a manual route
244 * add with a LL address.
246 R_Malloc(la
, struct llinfo_arp
*, sizeof *la
);
249 log(LOG_DEBUG
, "arp_rtrequest: malloc failed\n");
252 bzero(la
, sizeof *la
);
254 rt
->rt_flags
|= RTF_LLINFO
;
255 LIST_INSERT_HEAD(&llinfo_arp_list
[mycpuid
], la
, la_le
);
259 * This keeps the multicast addresses from showing up
260 * in `arp -a' listings as unresolved. It's not actually
261 * functional. Then the same for broadcast.
263 if (IN_MULTICAST(ntohl(SIN(rt_key(rt
))->sin_addr
.s_addr
))) {
264 ETHER_MAP_IP_MULTICAST(&SIN(rt_key(rt
))->sin_addr
,
266 SDL(gate
)->sdl_alen
= 6;
269 if (in_broadcast(SIN(rt_key(rt
))->sin_addr
, rt
->rt_ifp
)) {
270 memcpy(LLADDR(SDL(gate
)), rt
->rt_ifp
->if_broadcastaddr
,
271 rt
->rt_ifp
->if_addrlen
);
272 SDL(gate
)->sdl_alen
= rt
->rt_ifp
->if_addrlen
;
277 if (SIN(rt_key(rt
))->sin_addr
.s_addr
==
278 (IA_SIN(rt
->rt_ifa
))->sin_addr
.s_addr
) {
280 * This test used to be
281 * if (loif.if_flags & IFF_UP)
282 * It allowed local traffic to be forced
283 * through the hardware by configuring the
284 * loopback down. However, it causes problems
285 * during network configuration for boards
286 * that can't receive packets they send. It
287 * is now necessary to clear "useloopback" and
288 * remove the route to force traffic out to
292 bcopy(IF_LLADDR(rt
->rt_ifp
), LLADDR(SDL(gate
)),
293 SDL(gate
)->sdl_alen
= rt
->rt_ifp
->if_addrlen
);
302 LIST_REMOVE(la
, la_le
);
303 rt
->rt_llinfo
= NULL
;
304 rt
->rt_flags
&= ~RTF_LLINFO
;
305 if (la
->la_hold
!= NULL
)
306 m_freem(la
->la_hold
);
312 * Broadcast an ARP request. Caller specifies:
313 * - arp header source ip address
314 * - arp header target ip address
315 * - arp header source ethernet address
318 arprequest(struct ifnet
*ifp
, struct in_addr
*sip
, struct in_addr
*tip
,
322 struct ether_header
*eh
;
327 if ((m
= m_gethdr(MB_DONTWAIT
, MT_DATA
)) == NULL
)
329 m
->m_pkthdr
.rcvif
= (struct ifnet
*)NULL
;
331 switch (ifp
->if_type
) {
334 * This may not be correct for types not explicitly
335 * listed, but this is our best guess
338 ar_hrd
= htons(ARPHRD_ETHER
);
340 m
->m_len
= arphdr_len2(ifp
->if_addrlen
, sizeof(struct in_addr
));
341 m
->m_pkthdr
.len
= m
->m_len
;
342 MH_ALIGN(m
, m
->m_len
);
344 eh
= (struct ether_header
*)sa
.sa_data
;
345 /* if_output() will not swap */
346 eh
->ether_type
= htons(ETHERTYPE_ARP
);
347 memcpy(eh
->ether_dhost
, ifp
->if_broadcastaddr
, ifp
->if_addrlen
);
349 ah
= mtod(m
, struct arphdr
*);
354 ah
->ar_pro
= htons(ETHERTYPE_IP
);
355 ah
->ar_hln
= ifp
->if_addrlen
; /* hardware address length */
356 ah
->ar_pln
= sizeof(struct in_addr
); /* protocol address length */
357 ah
->ar_op
= htons(ARPOP_REQUEST
);
358 memcpy(ar_sha(ah
), enaddr
, ah
->ar_hln
);
359 memset(ar_tha(ah
), 0, ah
->ar_hln
);
360 memcpy(ar_spa(ah
), sip
, ah
->ar_pln
);
361 memcpy(ar_tpa(ah
), tip
, ah
->ar_pln
);
363 sa
.sa_family
= AF_UNSPEC
;
364 sa
.sa_len
= sizeof sa
;
365 (*ifp
->if_output
)(ifp
, m
, &sa
, (struct rtentry
*)NULL
);
369 * Resolve an IP address into an ethernet address. If success,
370 * desten is filled in. If there is no entry in arptab,
371 * set one up and broadcast a request for the IP address.
372 * Hold onto this mbuf and resend it once the address
373 * is finally resolved. A return value of 1 indicates
374 * that desten has been filled in and the packet should be sent
375 * normally; a 0 return indicates that the packet has been
376 * taken over here, either now or for later transmission.
383 struct sockaddr
*dst
,
387 struct llinfo_arp
*la
= NULL
;
388 struct sockaddr_dl
*sdl
;
390 if (m
->m_flags
& M_BCAST
) { /* broadcast */
391 memcpy(desten
, ifp
->if_broadcastaddr
, ifp
->if_addrlen
);
394 if (m
->m_flags
& M_MCAST
) {/* multicast */
395 ETHER_MAP_IP_MULTICAST(&SIN(dst
)->sin_addr
, desten
);
399 if (rt_llroute(dst
, rt0
, &rt
) != 0) {
406 la
= arplookup(SIN(dst
)->sin_addr
.s_addr
, TRUE
, FALSE
);
410 if (la
== NULL
|| rt
== NULL
) {
411 log(LOG_DEBUG
, "arpresolve: can't allocate llinfo for %s%s%s\n",
412 inet_ntoa(SIN(dst
)->sin_addr
), la
? "la" : " ",
417 sdl
= SDL(rt
->rt_gateway
);
419 * Check the address family and length is valid, the address
420 * is resolved; otherwise, try to resolve.
422 if ((rt
->rt_expire
== 0 || rt
->rt_expire
> time_second
) &&
423 sdl
->sdl_family
== AF_LINK
&& sdl
->sdl_alen
!= 0) {
425 * If entry has an expiry time and it is approaching,
426 * see if we need to send an ARP request within this
427 * arpt_down interval.
429 if ((rt
->rt_expire
!= 0) &&
430 (time_second
+ la
->la_preempt
> rt
->rt_expire
)) {
432 &SIN(rt
->rt_ifa
->ifa_addr
)->sin_addr
,
438 bcopy(LLADDR(sdl
), desten
, sdl
->sdl_alen
);
442 * If ARP is disabled on this interface, stop.
444 * Probably should not allocate empty llinfo struct if we are
445 * not going to be sending out an arp request.
447 if (ifp
->if_flags
& IFF_NOARP
) {
452 * There is an arptab entry, but no ethernet address
453 * response yet. Replace the held mbuf with this
456 if (la
->la_hold
!= NULL
)
457 m_freem(la
->la_hold
);
459 if (rt
->rt_expire
|| ((rt
->rt_flags
& RTF_STATIC
) && !sdl
->sdl_alen
)) {
460 rt
->rt_flags
&= ~RTF_REJECT
;
461 if (la
->la_asked
== 0 || rt
->rt_expire
!= time_second
) {
462 rt
->rt_expire
= time_second
;
463 if (la
->la_asked
++ < arp_maxtries
) {
465 &SIN(rt
->rt_ifa
->ifa_addr
)->sin_addr
,
469 rt
->rt_flags
|= RTF_REJECT
;
470 rt
->rt_expire
+= arpt_down
;
472 la
->la_preempt
= arp_maxtries
;
481 * Common length and type checks are done here,
482 * then the protocol-specific routine is called.
485 arpintr(struct netmsg
*msg
)
487 struct mbuf
*m
= ((struct netmsg_packet
*)msg
)->nm_packet
;
491 if (m
->m_len
< sizeof(struct arphdr
) &&
492 ((m
= m_pullup(m
, sizeof(struct arphdr
))) == NULL
)) {
493 log(LOG_ERR
, "arp: runt packet -- m_pullup failed\n");
496 ar
= mtod(m
, struct arphdr
*);
498 ar_hrd
= ntohs(ar
->ar_hrd
);
499 if (ar_hrd
!= ARPHRD_ETHER
&&
500 ar_hrd
!= ARPHRD_IEEE802
) {
502 "arp: unknown hardware address format (0x%2D)\n",
503 (unsigned char *)&ar
->ar_hrd
, "");
507 if (m
->m_pkthdr
.len
< arphdr_len(ar
) &&
508 (m
= m_pullup(m
, arphdr_len(ar
))) == NULL
) {
509 log(LOG_ERR
, "arp: runt packet\n");
513 switch (ntohs(ar
->ar_pro
)) {
524 /* msg was embedded in the mbuf, do not reply! */
529 * ARP for Internet protocols on 10 Mb/s Ethernet.
530 * Algorithm is that given in RFC 826.
531 * In addition, a sanity check is performed on the sender
532 * protocol address, to catch impersonators.
533 * We no longer handle negotiations for use of trailer protocol:
534 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent
535 * along with IP replies if we wanted trailers sent to us,
536 * and also sent them in response to IP replies.
537 * This allowed either end to announce the desire to receive
539 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either,
540 * but formerly didn't normally send requests.
542 static int log_arp_wrong_iface
= 1;
543 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, log_arp_wrong_iface
, CTLFLAG_RW
,
544 &log_arp_wrong_iface
, 0,
545 "log arp packets arriving on the wrong interface");
548 arp_update_oncpu(struct mbuf
*m
, in_addr_t saddr
, boolean_t create
,
551 struct arphdr
*ah
= mtod(m
, struct arphdr
*);
552 struct ifnet
*ifp
= m
->m_pkthdr
.rcvif
;
553 struct llinfo_arp
*la
;
554 struct sockaddr_dl
*sdl
;
558 la
= arplookup(saddr
, create
, FALSE
);
559 if (la
&& (rt
= la
->la_rt
) && (sdl
= SDL(rt
->rt_gateway
))) {
560 struct in_addr isaddr
= { saddr
};
562 /* the following is not an error when doing bridging */
563 if (rt
->rt_ifp
!= ifp
) {
564 if (dologging
&& log_arp_wrong_iface
&& cpu
== 0) {
567 "but got reply from %*D on %s\n",
569 rt
->rt_ifp
->if_xname
,
570 ifp
->if_addrlen
, (u_char
*)ar_sha(ah
), ":",
576 bcmp(ar_sha(ah
), LLADDR(sdl
), sdl
->sdl_alen
)) {
577 if (rt
->rt_expire
!= 0) {
578 if (dologging
&& cpu
== 0) {
580 "arp: %s moved from %*D to %*D on %s\n",
582 ifp
->if_addrlen
, (u_char
*)LLADDR(sdl
),
583 ":", ifp
->if_addrlen
,
584 (u_char
*)ar_sha(ah
), ":",
588 if (dologging
&& cpu
== 0) {
590 "arp: %*D attempts to modify permanent entry for %s on %s\n",
591 ifp
->if_addrlen
, (u_char
*)ar_sha(ah
), ":",
592 inet_ntoa(isaddr
), ifp
->if_xname
);
598 * sanity check for the address length.
599 * XXX this does not work for protocols with variable address
602 if (dologging
&& sdl
->sdl_alen
&& sdl
->sdl_alen
!= ah
->ar_hln
&&
606 "arp from %*D: new addr len %d, was %d",
607 ifp
->if_addrlen
, (u_char
*) ar_sha(ah
), ":",
608 ah
->ar_hln
, sdl
->sdl_alen
);
610 if (ifp
->if_addrlen
!= ah
->ar_hln
) {
611 if (dologging
&& cpu
== 0) {
613 "arp from %*D: addr len: new %d, i/f %d (ignored)",
614 ifp
->if_addrlen
, (u_char
*) ar_sha(ah
), ":",
615 ah
->ar_hln
, ifp
->if_addrlen
);
619 memcpy(LLADDR(sdl
), ar_sha(ah
), sdl
->sdl_alen
= ah
->ar_hln
);
620 if (rt
->rt_expire
!= 0)
621 rt
->rt_expire
= time_second
+ arpt_keep
;
622 rt
->rt_flags
&= ~RTF_REJECT
;
624 la
->la_preempt
= arp_maxtries
;
627 * This particular cpu might have been holding an mbuf
628 * pending ARP resolution. If so, transmit the mbuf now.
630 if (la
->la_hold
!= NULL
) {
631 m_adj(la
->la_hold
, sizeof(struct ether_header
));
632 lwkt_serialize_enter(ifp
->if_serializer
);
633 (*ifp
->if_output
)(ifp
, la
->la_hold
, rt_key(rt
), rt
);
634 lwkt_serialize_exit(ifp
->if_serializer
);
642 struct netmsg_arp_update
{
643 struct netmsg netmsg
;
649 static void arp_update_msghandler(struct netmsg
*netmsg
);
654 * Called from arpintr() - this routine is run from a single cpu.
657 in_arpinput(struct mbuf
*m
)
660 struct ifnet
*ifp
= m
->m_pkthdr
.rcvif
;
661 struct ether_header
*eh
;
664 struct in_ifaddr
*ia
;
666 struct in_addr isaddr
, itaddr
, myaddr
;
668 struct netmsg_arp_update msg
;
670 u_int8_t
*enaddr
= NULL
;
674 req_len
= arphdr_len2(ifp
->if_addrlen
, sizeof(struct in_addr
));
675 if (m
->m_len
< req_len
&& (m
= m_pullup(m
, req_len
)) == NULL
) {
676 log(LOG_ERR
, "in_arp: runt packet -- m_pullup failed\n");
680 ah
= mtod(m
, struct arphdr
*);
681 op
= ntohs(ah
->ar_op
);
682 memcpy(&isaddr
, ar_spa(ah
), sizeof isaddr
);
683 memcpy(&itaddr
, ar_tpa(ah
), sizeof itaddr
);
685 * Check both target and sender IP addresses:
687 * If we receive the packet on the interface owning the address,
688 * then accept the address.
690 * For a bridge, we accept the address if the receive interface and
691 * the interface owning the address are on the same bridge.
692 * (This will change slightly when we have clusters of interfaces).
694 LIST_FOREACH(ia
, INADDR_HASH(itaddr
.s_addr
), ia_hash
) {
695 /* Skip all ia's which don't match */
696 if (itaddr
.s_addr
!= ia
->ia_addr
.sin_addr
.s_addr
)
699 if (ia
->ia_ifp
== ifp
)
702 if (ifp
->if_bridge
&& ia
->ia_ifp
&&
703 ifp
->if_bridge
== ia
->ia_ifp
->if_bridge
)
708 * If the interface does not match, but the recieving interface
709 * is part of carp, we call carp_iamatch to see if this is a
710 * request for the virtual host ip.
711 * XXX: This is really ugly!
713 if (ifp
->if_carp
!= NULL
&&
714 carp_iamatch(ifp
->if_carp
, ia
, &isaddr
, &enaddr
) &&
715 itaddr
.s_addr
== ia
->ia_addr
.sin_addr
.s_addr
)
719 LIST_FOREACH(ia
, INADDR_HASH(isaddr
.s_addr
), ia_hash
) {
720 /* Skip all ia's which don't match */
721 if (isaddr
.s_addr
!= ia
->ia_addr
.sin_addr
.s_addr
)
724 if (ia
->ia_ifp
== ifp
)
727 if (ifp
->if_bridge
&& ia
->ia_ifp
&&
728 ifp
->if_bridge
== ia
->ia_ifp
->if_bridge
)
732 * No match, use the first inet address on the receive interface
733 * as a dummy address for the rest of the function.
735 TAILQ_FOREACH(ifa
, &ifp
->if_addrhead
, ifa_link
) {
736 if (ifa
->ifa_addr
&& ifa
->ifa_addr
->sa_family
== AF_INET
) {
742 * If we got here, we didn't find any suitable interface,
743 * so drop the packet.
750 enaddr
= (u_int8_t
*)IF_LLADDR(ifp
);
751 myaddr
= ia
->ia_addr
.sin_addr
;
752 if (!bcmp(ar_sha(ah
), enaddr
, ifp
->if_addrlen
)) {
753 m_freem(m
); /* it's from me, ignore it. */
756 if (!bcmp(ar_sha(ah
), ifp
->if_broadcastaddr
, ifp
->if_addrlen
)) {
758 "arp: link address is broadcast for IP address %s!\n",
763 if (isaddr
.s_addr
== myaddr
.s_addr
&& myaddr
.s_addr
!= 0) {
765 "arp: %*D is using my IP address %s!\n",
766 ifp
->if_addrlen
, (u_char
*)ar_sha(ah
), ":",
772 netmsg_init(&msg
.netmsg
, &curthread
->td_msgport
, 0,
773 arp_update_msghandler
);
775 msg
.saddr
= isaddr
.s_addr
;
776 msg
.create
= (itaddr
.s_addr
== myaddr
.s_addr
);
777 lwkt_domsg(rtable_portfn(0), &msg
.netmsg
.nm_lmsg
, 0);
779 arp_update_oncpu(m
, isaddr
.s_addr
, (itaddr
.s_addr
== myaddr
.s_addr
),
782 if (op
!= ARPOP_REQUEST
) {
786 if (itaddr
.s_addr
== myaddr
.s_addr
) {
787 /* I am the target */
788 memcpy(ar_tha(ah
), ar_sha(ah
), ah
->ar_hln
);
789 memcpy(ar_sha(ah
), enaddr
, ah
->ar_hln
);
791 struct llinfo_arp
*la
;
793 la
= arplookup(itaddr
.s_addr
, FALSE
, SIN_PROXY
);
795 struct sockaddr_in sin
;
802 bzero(&sin
, sizeof sin
);
803 sin
.sin_family
= AF_INET
;
804 sin
.sin_len
= sizeof sin
;
805 sin
.sin_addr
= itaddr
;
807 rt
= rtpurelookup((struct sockaddr
*)&sin
);
814 * Don't send proxies for nodes on the same interface
815 * as this one came out of, or we'll get into a fight
816 * over who claims what Ether address.
818 if (rt
->rt_ifp
== ifp
) {
822 memcpy(ar_tha(ah
), ar_sha(ah
), ah
->ar_hln
);
823 memcpy(ar_sha(ah
), enaddr
, ah
->ar_hln
);
825 kprintf("arp: proxying for %s\n", inet_ntoa(itaddr
));
828 struct sockaddr_dl
*sdl
;
831 memcpy(ar_tha(ah
), ar_sha(ah
), ah
->ar_hln
);
832 sdl
= SDL(rt
->rt_gateway
);
833 memcpy(ar_sha(ah
), LLADDR(sdl
), ah
->ar_hln
);
837 memcpy(ar_tpa(ah
), ar_spa(ah
), ah
->ar_pln
);
838 memcpy(ar_spa(ah
), &itaddr
, ah
->ar_pln
);
839 ah
->ar_op
= htons(ARPOP_REPLY
);
840 ah
->ar_pro
= htons(ETHERTYPE_IP
); /* let's be sure! */
841 switch (ifp
->if_type
) {
844 * May not be correct for types not explictly
845 * listed, but it is our best guess.
848 eh
= (struct ether_header
*)sa
.sa_data
;
849 memcpy(eh
->ether_dhost
, ar_tha(ah
), sizeof eh
->ether_dhost
);
850 eh
->ether_type
= htons(ETHERTYPE_ARP
);
853 sa
.sa_family
= AF_UNSPEC
;
854 sa
.sa_len
= sizeof sa
;
855 lwkt_serialize_enter(ifp
->if_serializer
);
856 (*ifp
->if_output
)(ifp
, m
, &sa
, (struct rtentry
*)0);
857 lwkt_serialize_exit(ifp
->if_serializer
);
865 arp_update_msghandler(struct netmsg
*netmsg
)
867 struct netmsg_arp_update
*msg
= (struct netmsg_arp_update
*)netmsg
;
870 arp_update_oncpu(msg
->m
, msg
->saddr
, msg
->create
, FALSE
);
872 nextcpu
= mycpuid
+ 1;
873 if (nextcpu
< ncpus
) {
874 lwkt_forwardmsg(rtable_portfn(nextcpu
), &msg
->netmsg
.nm_lmsg
);
876 lwkt_replymsg(&msg
->netmsg
.nm_lmsg
, 0);
885 * Free an arp entry. If the arp entry is actively referenced or represents
886 * a static entry we only clear it back to an unresolved state, otherwise
887 * we destroy the entry entirely.
889 * Note that static entries are created when route add ... -interface is used
890 * to create an interface route to a (direct) destination.
893 arptfree(struct llinfo_arp
*la
)
895 struct rtentry
*rt
= la
->la_rt
;
896 struct sockaddr_dl
*sdl
;
900 sdl
= SDL(rt
->rt_gateway
);
902 ((rt
->rt_refcnt
> 0 && sdl
->sdl_family
== AF_LINK
) ||
903 (rt
->rt_flags
& RTF_STATIC
))) {
905 la
->la_preempt
= la
->la_asked
= 0;
906 rt
->rt_flags
&= ~RTF_REJECT
;
909 rtrequest(RTM_DELETE
, rt_key(rt
), NULL
, rt_mask(rt
), 0, NULL
);
913 * Lookup or enter a new address in arptab.
915 static struct llinfo_arp
*
916 arplookup(in_addr_t addr
, boolean_t create
, boolean_t proxy
)
919 struct sockaddr_inarp sin
= { sizeof sin
, AF_INET
};
920 const char *why
= NULL
;
922 sin
.sin_addr
.s_addr
= addr
;
923 sin
.sin_other
= proxy
? SIN_PROXY
: 0;
925 rt
= rtlookup((struct sockaddr
*)&sin
);
927 rt
= rtpurelookup((struct sockaddr
*)&sin
);
932 if (rt
->rt_flags
& RTF_GATEWAY
)
933 why
= "host is not on local network";
934 else if (!(rt
->rt_flags
& RTF_LLINFO
))
935 why
= "could not allocate llinfo";
936 else if (rt
->rt_gateway
->sa_family
!= AF_LINK
)
937 why
= "gateway route is not ours";
941 log(LOG_DEBUG
, "arplookup %s failed: %s\n",
942 inet_ntoa(sin
.sin_addr
), why
);
944 if (rt
->rt_refcnt
<= 0 && (rt
->rt_flags
& RTF_WASCLONED
)) {
945 /* No references to this route. Purge it. */
946 rtrequest(RTM_DELETE
, rt_key(rt
), rt
->rt_gateway
,
947 rt_mask(rt
), rt
->rt_flags
, NULL
);
951 return (rt
->rt_llinfo
);
955 arp_ifinit(struct ifnet
*ifp
, struct ifaddr
*ifa
)
957 if (IA_SIN(ifa
)->sin_addr
.s_addr
!= INADDR_ANY
)
958 arprequest(ifp
, &IA_SIN(ifa
)->sin_addr
, &IA_SIN(ifa
)->sin_addr
,
960 ifa
->ifa_rtrequest
= arp_rtrequest
;
961 ifa
->ifa_flags
|= RTF_CLONING
;
965 arp_ifinit2(struct ifnet
*ifp
, struct ifaddr
*ifa
, u_char
*enaddr
)
967 if (IA_SIN(ifa
)->sin_addr
.s_addr
!= INADDR_ANY
)
968 arprequest(ifp
, &IA_SIN(ifa
)->sin_addr
, &IA_SIN(ifa
)->sin_addr
,
970 ifa
->ifa_rtrequest
= arp_rtrequest
;
971 ifa
->ifa_flags
|= RTF_CLONING
;
979 for (cpu
= 0; cpu
< ncpus2
; cpu
++)
980 LIST_INIT(&llinfo_arp_list
[cpu
]);
981 netisr_register(NETISR_ARP
, cpu0_portfn
, arpintr
);
984 SYSINIT(arp
, SI_SUB_PROTO_DOMAIN
, SI_ORDER_ANY
, arp_init
, 0);