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
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61 * @(#)if_ether.c 8.1 (Berkeley) 6/10/93
62 * $FreeBSD: src/sys/netinet/if_ether.c,v 1.64.2.23 2003/04/11 07:23:15 fjoe Exp $
66 * Ethernet address resolution protocol.
68 * add "inuse/lock" bit (or ref. count) along with valid bit
74 #include <sys/param.h>
75 #include <sys/kernel.h>
76 #include <sys/queue.h>
77 #include <sys/sysctl.h>
78 #include <sys/systm.h>
80 #include <sys/malloc.h>
81 #include <sys/socket.h>
82 #include <sys/syslog.h>
86 #include <net/if_dl.h>
87 #include <net/if_types.h>
88 #include <net/route.h>
89 #include <net/netisr.h>
90 #include <net/if_llc.h>
92 #include <netinet/in.h>
93 #include <netinet/in_var.h>
94 #include <netinet/if_ether.h>
96 #include <sys/thread2.h>
97 #include <sys/msgport2.h>
98 #include <net/netmsg2.h>
99 #include <net/netisr2.h>
100 #include <sys/mplock2.h>
103 #include <netinet/ip_carp.h>
106 #define SIN(s) ((struct sockaddr_in *)s)
107 #define SDL(s) ((struct sockaddr_dl *)s)
109 MALLOC_DEFINE(M_ARP
, "arp", "ARP");
111 SYSCTL_DECL(_net_link_ether
);
112 SYSCTL_NODE(_net_link_ether
, PF_INET
, inet
, CTLFLAG_RW
, 0, "");
115 static int arpt_prune
= (5*60*1); /* walk list every 5 minutes */
116 static int arpt_keep
= (20*60); /* once resolved, good for 20 more minutes */
117 static int arpt_down
= 20; /* once declared down, don't send for 20 sec */
119 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, prune_intvl
, CTLFLAG_RW
,
121 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, max_age
, CTLFLAG_RW
,
123 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, host_down_time
, CTLFLAG_RW
,
126 #define rt_expire rt_rmx.rmx_expire
129 LIST_ENTRY(llinfo_arp
) la_le
;
130 struct rtentry
*la_rt
;
131 struct mbuf
*la_hold
; /* last packet until resolved/timeout */
132 u_short la_preempt
; /* countdown for pre-expiry arps */
133 u_short la_asked
; /* #times we QUERIED following expiration */
136 static int arp_maxtries
= 5;
137 static int useloopback
= 1; /* use loopback interface for local traffic */
138 static int arp_proxyall
= 0;
139 static int arp_refresh
= 60; /* refresh arp cache ~60 (not impl yet) */
140 static int arp_restricted_match
= 0;
141 static int arp_ignore_probes
= 1;
143 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, maxtries
, CTLFLAG_RW
,
144 &arp_maxtries
, 0, "ARP resolution attempts before returning error");
145 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, useloopback
, CTLFLAG_RW
,
146 &useloopback
, 0, "Use the loopback interface for local traffic");
147 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, proxyall
, CTLFLAG_RW
,
148 &arp_proxyall
, 0, "Enable proxy ARP for all suitable requests");
149 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, restricted_match
, CTLFLAG_RW
,
150 &arp_restricted_match
, 0, "Only match against the sender");
151 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, refresh
, CTLFLAG_RW
,
152 &arp_refresh
, 0, "Preemptively refresh the ARP");
153 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, ignore_probes
, CTLFLAG_RW
,
154 &arp_ignore_probes
, 0, "Ignore ARP probes");
156 static void arp_rtrequest(int, struct rtentry
*);
157 static void arprequest(struct ifnet
*, const struct in_addr
*,
158 const struct in_addr
*, const u_char
*);
159 static void arprequest_async(struct ifnet
*, const struct in_addr
*,
160 const struct in_addr
*, const u_char
*);
161 static void arpintr(netmsg_t msg
);
162 static void arptfree(struct llinfo_arp
*);
163 static void arptimer(void *);
164 static struct llinfo_arp
*
165 arplookup(in_addr_t
, boolean_t
, boolean_t
, boolean_t
);
167 static void in_arpinput(struct mbuf
*);
168 static void in_arpreply(struct mbuf
*m
, in_addr_t
, in_addr_t
);
169 static void arp_update_msghandler(netmsg_t
);
170 static void arp_reply_msghandler(netmsg_t
);
173 struct arp_pcpu_data
{
174 LIST_HEAD(, llinfo_arp
) llinfo_list
;
175 struct callout timer_ch
;
176 struct netmsg_base timer_nmsg
;
179 static struct arp_pcpu_data
*arp_data
[MAXCPU
];
182 * Timeout routine. Age arp_tab entries periodically.
185 arptimer_dispatch(netmsg_t nmsg
)
187 struct arp_pcpu_data
*ad
= nmsg
->lmsg
.u
.ms_resultp
;
188 struct llinfo_arp
*la
, *nla
;
190 ASSERT_NETISR_NCPUS(mycpuid
);
194 netisr_replymsg(&nmsg
->base
, 0);
197 LIST_FOREACH_MUTABLE(la
, &ad
->llinfo_list
, la_le
, nla
) {
198 if (la
->la_rt
->rt_expire
&& la
->la_rt
->rt_expire
<= time_uptime
)
201 callout_reset(&ad
->timer_ch
, arpt_prune
* hz
, arptimer
, &ad
->timer_nmsg
);
207 struct netmsg_base
*nm
= xnm
;
209 KKASSERT(mycpuid
< netisr_ncpus
);
212 if (nm
->lmsg
.ms_flags
& MSGF_DONE
)
213 netisr_sendmsg_oncpu(nm
);
218 * Parallel to llc_rtrequest.
220 * Called after a route is successfully added to the tree to fix-up the
221 * route and initiate arp operations if required.
224 arp_rtrequest(int req
, struct rtentry
*rt
)
226 struct sockaddr
*gate
= rt
->rt_gateway
;
227 struct llinfo_arp
*la
= rt
->rt_llinfo
;
229 struct sockaddr_dl null_sdl
= { sizeof null_sdl
, AF_LINK
};
231 if (rt
->rt_flags
& RTF_GATEWAY
)
237 * XXX: If this is a manually added route to interface
238 * such as older version of routed or gated might provide,
239 * restore cloning bit.
241 if (!(rt
->rt_flags
& RTF_HOST
) &&
242 SIN(rt_mask(rt
))->sin_addr
.s_addr
!= 0xffffffff)
243 rt
->rt_flags
|= RTF_CLONING
;
244 if (rt
->rt_flags
& RTF_CLONING
) {
246 * Case 1: This route should come from a route to iface.
248 rt_setgate(rt
, rt_key(rt
),
249 (struct sockaddr
*)&null_sdl
,
251 gate
= rt
->rt_gateway
;
252 SDL(gate
)->sdl_type
= rt
->rt_ifp
->if_type
;
253 SDL(gate
)->sdl_index
= rt
->rt_ifp
->if_index
;
254 rt
->rt_expire
= time_uptime
;
258 * Announce a new entry if requested, and only announce it
261 if ((rt
->rt_flags
& RTF_ANNOUNCE
) && mycpuid
== 0) {
262 arprequest(rt
->rt_ifp
,
263 &SIN(rt_key(rt
))->sin_addr
,
264 &SIN(rt_key(rt
))->sin_addr
,
269 if (gate
->sa_family
!= AF_LINK
||
270 gate
->sa_len
< sizeof(struct sockaddr_dl
)) {
271 log(LOG_DEBUG
, "arp_rtrequest: bad gateway value\n");
274 SDL(gate
)->sdl_type
= rt
->rt_ifp
->if_type
;
275 SDL(gate
)->sdl_index
= rt
->rt_ifp
->if_index
;
277 break; /* This happens on a route change */
279 * Case 2: This route may come from cloning, or a manual route
280 * add with a LL address.
282 R_Malloc(la
, struct llinfo_arp
*, sizeof *la
);
285 log(LOG_DEBUG
, "arp_rtrequest: malloc failed\n");
288 bzero(la
, sizeof *la
);
290 rt
->rt_flags
|= RTF_LLINFO
;
291 LIST_INSERT_HEAD(&arp_data
[mycpuid
]->llinfo_list
, la
, la_le
);
295 * This keeps the multicast addresses from showing up
296 * in `arp -a' listings as unresolved. It's not actually
297 * functional. Then the same for broadcast.
299 if (IN_MULTICAST(ntohl(SIN(rt_key(rt
))->sin_addr
.s_addr
))) {
300 ETHER_MAP_IP_MULTICAST(&SIN(rt_key(rt
))->sin_addr
,
302 SDL(gate
)->sdl_alen
= 6;
305 if (in_broadcast(SIN(rt_key(rt
))->sin_addr
, rt
->rt_ifp
)) {
306 memcpy(LLADDR(SDL(gate
)), rt
->rt_ifp
->if_broadcastaddr
,
307 rt
->rt_ifp
->if_addrlen
);
308 SDL(gate
)->sdl_alen
= rt
->rt_ifp
->if_addrlen
;
314 * This fixes up the routing interface for local addresses.
315 * The route is adjusted to point at lo0 and the expiration
318 * NOTE: This prevents locally targetted traffic from going
319 * out the hardware interface, which is inefficient
320 * and might not work if the hardware cannot listen
321 * to its own transmitted packets. Setting
322 * net.link.ether.inet.useloopback to 0 will force
323 * packets for local addresses out the hardware (and
324 * it is expected to receive its own packet).
326 * XXX We should just be able to test RTF_LOCAL here instead
327 * of having to compare IPs.
329 if (SIN(rt_key(rt
))->sin_addr
.s_addr
==
330 (IA_SIN(rt
->rt_ifa
))->sin_addr
.s_addr
) {
332 bcopy(IF_LLADDR(rt
->rt_ifp
), LLADDR(SDL(gate
)),
333 SDL(gate
)->sdl_alen
= rt
->rt_ifp
->if_addrlen
);
342 LIST_REMOVE(la
, la_le
);
343 rt
->rt_llinfo
= NULL
;
344 rt
->rt_flags
&= ~RTF_LLINFO
;
345 if (la
->la_hold
!= NULL
)
346 m_freem(la
->la_hold
);
353 arpreq_alloc(struct ifnet
*ifp
, const struct in_addr
*sip
,
354 const struct in_addr
*tip
, const u_char
*enaddr
)
360 if ((m
= m_gethdr(M_NOWAIT
, MT_DATA
)) == NULL
)
362 m
->m_pkthdr
.rcvif
= NULL
;
364 switch (ifp
->if_type
) {
367 * This may not be correct for types not explicitly
368 * listed, but this is our best guess
371 ar_hrd
= htons(ARPHRD_ETHER
);
373 m
->m_len
= arphdr_len2(ifp
->if_addrlen
, sizeof(struct in_addr
));
374 m
->m_pkthdr
.len
= m
->m_len
;
375 MH_ALIGN(m
, m
->m_len
);
377 ah
= mtod(m
, struct arphdr
*);
382 ah
->ar_pro
= htons(ETHERTYPE_IP
);
383 ah
->ar_hln
= ifp
->if_addrlen
; /* hardware address length */
384 ah
->ar_pln
= sizeof(struct in_addr
); /* protocol address length */
385 ah
->ar_op
= htons(ARPOP_REQUEST
);
386 memcpy(ar_sha(ah
), enaddr
, ah
->ar_hln
);
387 memset(ar_tha(ah
), 0, ah
->ar_hln
);
388 memcpy(ar_spa(ah
), sip
, ah
->ar_pln
);
389 memcpy(ar_tpa(ah
), tip
, ah
->ar_pln
);
395 arpreq_send(struct ifnet
*ifp
, struct mbuf
*m
)
398 struct ether_header
*eh
;
400 ASSERT_NETISR_NCPUS(mycpuid
);
402 switch (ifp
->if_type
) {
405 * This may not be correct for types not explicitly
406 * listed, but this is our best guess
409 eh
= (struct ether_header
*)sa
.sa_data
;
410 /* if_output() will not swap */
411 eh
->ether_type
= htons(ETHERTYPE_ARP
);
412 memcpy(eh
->ether_dhost
, ifp
->if_broadcastaddr
, ifp
->if_addrlen
);
416 sa
.sa_family
= AF_UNSPEC
;
417 sa
.sa_len
= sizeof(sa
);
418 ifp
->if_output(ifp
, m
, &sa
, NULL
);
422 arpreq_send_handler(netmsg_t msg
)
424 struct mbuf
*m
= msg
->packet
.nm_packet
;
425 struct ifnet
*ifp
= msg
->lmsg
.u
.ms_resultp
;
428 /* nmsg was embedded in the mbuf, do not reply! */
432 * Broadcast an ARP request. Caller specifies:
433 * - arp header source ip address
434 * - arp header target ip address
435 * - arp header source ethernet address
437 * NOTE: Caller MUST NOT hold ifp's serializer
440 arprequest(struct ifnet
*ifp
, const struct in_addr
*sip
,
441 const struct in_addr
*tip
, const u_char
*enaddr
)
445 ASSERT_NETISR_NCPUS(mycpuid
);
447 if (enaddr
== NULL
) {
448 if (ifp
->if_bridge
) {
449 enaddr
= IF_LLADDR(ether_bridge_interface(ifp
));
451 enaddr
= IF_LLADDR(ifp
);
455 m
= arpreq_alloc(ifp
, sip
, tip
, enaddr
);
462 * Same as arprequest(), except:
463 * - Caller is allowed to hold ifp's serializer
464 * - Network output is done in protocol thead
467 arprequest_async(struct ifnet
*ifp
, const struct in_addr
*sip
,
468 const struct in_addr
*tip
, const u_char
*enaddr
)
471 struct netmsg_packet
*pmsg
;
474 if (enaddr
== NULL
) {
475 if (ifp
->if_bridge
) {
476 enaddr
= IF_LLADDR(ether_bridge_interface(ifp
));
478 enaddr
= IF_LLADDR(ifp
);
481 m
= arpreq_alloc(ifp
, sip
, tip
, enaddr
);
485 pmsg
= &m
->m_hdr
.mh_netmsg
;
486 netmsg_init(&pmsg
->base
, NULL
, &netisr_apanic_rport
,
487 0, arpreq_send_handler
);
489 pmsg
->base
.lmsg
.u
.ms_resultp
= ifp
;
491 if (mycpuid
< netisr_ncpus
)
495 lwkt_sendmsg(netisr_cpuport(cpu
), &pmsg
->base
.lmsg
);
499 * Resolve an IP address into an ethernet address. If success,
500 * desten is filled in. If there is no entry in arptab,
501 * set one up and broadcast a request for the IP address.
502 * Hold onto this mbuf and resend it once the address
503 * is finally resolved. A return value of 1 indicates
504 * that desten has been filled in and the packet should be sent
505 * normally; a 0 return indicates that the packet has been
506 * taken over here, either now or for later transmission.
509 arpresolve(struct ifnet
*ifp
, struct rtentry
*rt0
, struct mbuf
*m
,
510 struct sockaddr
*dst
, u_char
*desten
)
512 struct rtentry
*rt
= NULL
;
513 struct llinfo_arp
*la
= NULL
;
514 struct sockaddr_dl
*sdl
;
516 if (m
->m_flags
& M_BCAST
) { /* broadcast */
517 memcpy(desten
, ifp
->if_broadcastaddr
, ifp
->if_addrlen
);
520 if (m
->m_flags
& M_MCAST
) {/* multicast */
521 ETHER_MAP_IP_MULTICAST(&SIN(dst
)->sin_addr
, desten
);
525 if (rt_llroute(dst
, rt0
, &rt
) != 0) {
532 la
= arplookup(SIN(dst
)->sin_addr
.s_addr
,
533 TRUE
, RTL_REPORTMSG
, FALSE
);
537 if (la
== NULL
|| rt
== NULL
) {
538 char addr
[INET_ADDRSTRLEN
];
540 log(LOG_DEBUG
, "arpresolve: can't allocate llinfo for %s%s%s\n",
541 kinet_ntoa(SIN(dst
)->sin_addr
, addr
), la
? "la" : " ",
546 sdl
= SDL(rt
->rt_gateway
);
548 * Check the address family and length is valid, the address
549 * is resolved; otherwise, try to resolve.
551 if ((rt
->rt_expire
== 0 || rt
->rt_expire
> time_uptime
) &&
552 sdl
->sdl_family
== AF_LINK
&& sdl
->sdl_alen
!= 0) {
554 * If entry has an expiry time and it is approaching,
555 * see if we need to send an ARP request within this
556 * arpt_down interval.
558 if ((rt
->rt_expire
!= 0) &&
559 (time_uptime
+ la
->la_preempt
> rt
->rt_expire
)) {
561 &SIN(rt
->rt_ifa
->ifa_addr
)->sin_addr
,
567 bcopy(LLADDR(sdl
), desten
, sdl
->sdl_alen
);
571 * If ARP is disabled or static on this interface, stop.
573 * Probably should not allocate empty llinfo struct if we are
574 * not going to be sending out an arp request.
576 if (ifp
->if_flags
& (IFF_NOARP
| IFF_STATICARP
)) {
581 * There is an arptab entry, but no ethernet address
582 * response yet. Replace the held mbuf with this
585 if (la
->la_hold
!= NULL
)
586 m_freem(la
->la_hold
);
588 if (rt
->rt_expire
|| ((rt
->rt_flags
& RTF_STATIC
) && !sdl
->sdl_alen
)) {
589 rt
->rt_flags
&= ~RTF_REJECT
;
590 if (la
->la_asked
== 0 || rt
->rt_expire
!= time_uptime
) {
591 rt
->rt_expire
= time_uptime
;
592 if (la
->la_asked
++ < arp_maxtries
) {
594 &SIN(rt
->rt_ifa
->ifa_addr
)->sin_addr
,
598 rt
->rt_flags
|= RTF_REJECT
;
599 rt
->rt_expire
+= arpt_down
;
601 la
->la_preempt
= arp_maxtries
;
609 * Common length and type checks are done here,
610 * then the protocol-specific routine is called.
613 arpintr(netmsg_t msg
)
615 struct mbuf
*m
= msg
->packet
.nm_packet
;
620 if (m
->m_len
< sizeof(struct arphdr
) &&
621 (m
= m_pullup(m
, sizeof(struct arphdr
))) == NULL
) {
622 log(LOG_ERR
, "arp: runt packet -- m_pullup failed\n");
625 ar
= mtod(m
, struct arphdr
*);
627 ar_hrd
= ntohs(ar
->ar_hrd
);
628 if (ar_hrd
!= ARPHRD_ETHER
&& ar_hrd
!= ARPHRD_IEEE802
) {
629 hexncpy((unsigned char *)&ar
->ar_hrd
, 2, hexstr
, 5, NULL
);
630 log(LOG_ERR
, "arp: unknown hardware address format (0x%s)\n",
636 if (m
->m_pkthdr
.len
< arphdr_len(ar
)) {
637 if ((m
= m_pullup(m
, arphdr_len(ar
))) == NULL
) {
638 log(LOG_ERR
, "arp: runt packet\n");
641 ar
= mtod(m
, struct arphdr
*);
644 switch (ntohs(ar
->ar_pro
)) {
652 /* msg was embedded in the mbuf, do not reply! */
657 * ARP for Internet protocols on 10 Mb/s Ethernet.
658 * Algorithm is that given in RFC 826.
659 * In addition, a sanity check is performed on the sender
660 * protocol address, to catch impersonators.
661 * We no longer handle negotiations for use of trailer protocol:
662 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent
663 * along with IP replies if we wanted trailers sent to us,
664 * and also sent them in response to IP replies.
665 * This allowed either end to announce the desire to receive
667 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either,
668 * but formerly didn't normally send requests.
671 static int log_arp_wrong_iface
= 1;
672 static int log_arp_movements
= 1;
673 static int log_arp_permanent_modify
= 1;
674 static int log_arp_creation_failure
= 1;
676 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, log_arp_wrong_iface
, CTLFLAG_RW
,
677 &log_arp_wrong_iface
, 0,
678 "Log arp packets arriving on the wrong interface");
679 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, log_arp_movements
, CTLFLAG_RW
,
680 &log_arp_movements
, 0,
681 "Log arp replies from MACs different than the one in the cache");
682 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, log_arp_permanent_modify
, CTLFLAG_RW
,
683 &log_arp_permanent_modify
, 0,
684 "Log arp replies from MACs different than the one "
685 "in the permanent arp entry");
686 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, log_arp_creation_failure
, CTLFLAG_RW
,
687 &log_arp_creation_failure
, 0, "Log arp creation failure");
690 * Returns non-zero if the routine updated anything.
693 arp_update_oncpu(struct mbuf
*m
, in_addr_t saddr
, boolean_t create
,
694 boolean_t generate_report
, boolean_t dologging
)
696 struct arphdr
*ah
= mtod(m
, struct arphdr
*);
697 struct ifnet
*ifp
= m
->m_pkthdr
.rcvif
;
698 struct llinfo_arp
*la
;
699 struct sockaddr_dl
*sdl
;
702 char sbuf
[INET_ADDRSTRLEN
];
703 int changed
= create
;
705 KASSERT(curthread
->td_type
== TD_TYPE_NETISR
,
706 ("arp update not in netisr"));
708 la
= arplookup(saddr
, create
, generate_report
, FALSE
);
709 if (la
&& (rt
= la
->la_rt
) && (sdl
= SDL(rt
->rt_gateway
))) {
710 struct in_addr isaddr
= { saddr
};
713 * Normally arps coming in on the wrong interface are ignored,
714 * but if we are bridging and the two interfaces belong to
715 * the same bridge, or one is a member of the bridge which
716 * is the other, then it isn't an error.
718 if (rt
->rt_ifp
!= ifp
) {
720 * (1) ifp and rt_ifp both members of same bridge
721 * (2) rt_ifp member of bridge ifp
722 * (3) ifp member of bridge rt_ifp
724 * Always replace rt_ifp with the bridge ifc.
728 if (ifp
->if_bridge
&&
729 rt
->rt_ifp
->if_bridge
== ifp
->if_bridge
) {
730 nifp
= ether_bridge_interface(ifp
);
731 } else if (rt
->rt_ifp
->if_bridge
&&
732 ether_bridge_interface(rt
->rt_ifp
) == ifp
) {
734 } else if (ifp
->if_bridge
&&
735 ether_bridge_interface(ifp
) == rt
->rt_ifp
) {
741 if ((log_arp_wrong_iface
== 1 && nifp
== NULL
) ||
742 log_arp_wrong_iface
== 2) {
743 hexncpy((u_char
*)ar_sha(ah
), ifp
->if_addrlen
,
744 hexstr
[0], HEX_NCPYLEN(ifp
->if_addrlen
), ":");
747 "but got reply from %s on %s\n",
748 kinet_ntoa(isaddr
, sbuf
),
749 rt
->rt_ifp
->if_xname
, hexstr
[0],
756 * nifp is our man! Replace rt_ifp and adjust
759 ifp
= rt
->rt_ifp
= nifp
;
760 if (sdl
->sdl_type
!= ifp
->if_type
) {
761 sdl
->sdl_type
= ifp
->if_type
;
764 if (sdl
->sdl_index
!= ifp
->if_index
) {
765 sdl
->sdl_index
= ifp
->if_index
;
770 bcmp(ar_sha(ah
), LLADDR(sdl
), sdl
->sdl_alen
)) {
772 if (rt
->rt_expire
!= 0) {
773 if (dologging
&& log_arp_movements
) {
774 hexncpy((u_char
*)LLADDR(sdl
), ifp
->if_addrlen
,
775 hexstr
[0], HEX_NCPYLEN(ifp
->if_addrlen
), ":");
776 hexncpy((u_char
*)ar_sha(ah
), ifp
->if_addrlen
,
777 hexstr
[1], HEX_NCPYLEN(ifp
->if_addrlen
), ":");
779 "arp: %s moved from %s to %s on %s\n",
780 kinet_ntoa(isaddr
, sbuf
), hexstr
[0], hexstr
[1],
784 if (dologging
&& log_arp_permanent_modify
) {
785 hexncpy((u_char
*)ar_sha(ah
), ifp
->if_addrlen
,
786 hexstr
[0], HEX_NCPYLEN(ifp
->if_addrlen
), ":");
788 "arp: %s attempts to modify "
789 "permanent entry for %s on %s\n",
790 hexstr
[0], kinet_ntoa(isaddr
, sbuf
), ifp
->if_xname
);
796 * sanity check for the address length.
797 * XXX this does not work for protocols with variable address
800 if (dologging
&& sdl
->sdl_alen
&& sdl
->sdl_alen
!= ah
->ar_hln
) {
801 hexncpy((u_char
*)ar_sha(ah
), ifp
->if_addrlen
,
802 hexstr
[0], HEX_NCPYLEN(ifp
->if_addrlen
), ":");
804 "arp from %s: new addr len %d, was %d",
805 hexstr
[0], ah
->ar_hln
, sdl
->sdl_alen
);
807 if (ifp
->if_addrlen
!= ah
->ar_hln
) {
809 hexncpy((u_char
*)ar_sha(ah
), ifp
->if_addrlen
,
810 hexstr
[0], HEX_NCPYLEN(ifp
->if_addrlen
), ":");
812 "arp from %s: addr len: new %d, i/f %d "
813 "(ignored)", hexstr
[0],
814 ah
->ar_hln
, ifp
->if_addrlen
);
818 memcpy(LLADDR(sdl
), ar_sha(ah
), sdl
->sdl_alen
= ah
->ar_hln
);
819 if (rt
->rt_expire
!= 0) {
820 if (rt
->rt_expire
!= time_uptime
+ arpt_keep
&&
821 rt
->rt_expire
!= time_uptime
+ arpt_keep
- 1) {
822 rt
->rt_expire
= time_uptime
+ arpt_keep
;
826 if (rt
->rt_flags
& RTF_REJECT
) {
827 rt
->rt_flags
&= ~RTF_REJECT
;
830 if (la
->la_asked
!= 0) {
834 if (la
->la_preempt
!= arp_maxtries
) {
835 la
->la_preempt
= arp_maxtries
;
840 * This particular cpu might have been holding an mbuf
841 * pending ARP resolution. If so, transmit the mbuf now.
843 if (la
->la_hold
!= NULL
) {
844 struct mbuf
*m
= la
->la_hold
;
847 m_adj(m
, sizeof(struct ether_header
));
848 ifp
->if_output(ifp
, m
, rt_key(rt
), rt
);
856 * Called from arpintr() - this routine is run from a single cpu.
859 in_arpinput(struct mbuf
*m
)
862 struct ifnet
*ifp
= m
->m_pkthdr
.rcvif
;
863 struct ifaddr_container
*ifac
;
864 struct in_ifaddr_container
*iac
;
865 struct in_ifaddr
*ia
= NULL
;
866 struct in_addr isaddr
, itaddr
, myaddr
;
867 uint8_t *enaddr
= NULL
;
870 char hexstr
[64], sbuf
[INET_ADDRSTRLEN
];
872 req_len
= arphdr_len2(ifp
->if_addrlen
, sizeof(struct in_addr
));
873 if (m
->m_len
< req_len
&& (m
= m_pullup(m
, req_len
)) == NULL
) {
874 log(LOG_ERR
, "in_arp: runt packet -- m_pullup failed\n");
878 ah
= mtod(m
, struct arphdr
*);
879 memcpy(&isaddr
, ar_spa(ah
), sizeof isaddr
);
880 memcpy(&itaddr
, ar_tpa(ah
), sizeof itaddr
);
883 * Check both target and sender IP addresses:
885 * If we receive the packet on the interface owning the address,
886 * then accept the address.
888 * For a bridge, we accept the address if the receive interface and
889 * the interface owning the address are on the same bridge, and
890 * use the bridge MAC as the is-at response. The bridge will be
891 * responsible for handling the packet.
893 * (0) Check target IP against CARP IPs
896 LIST_FOREACH(iac
, INADDR_HASH(itaddr
.s_addr
), ia_hash
) {
897 int is_match
= 0, is_parent
= 0;
901 /* Skip all ia's which don't match */
902 if (itaddr
.s_addr
!= ia
->ia_addr
.sin_addr
.s_addr
)
905 if (ia
->ia_ifp
->if_type
!= IFT_CARP
)
908 if (carp_parent(ia
->ia_ifp
) == ifp
)
910 if (is_parent
|| ia
->ia_ifp
== ifp
)
911 is_match
= carp_iamatch(ia
);
916 * The parent interface will also receive
917 * the ethernet broadcast packets, e.g. ARP
918 * REQUEST, so if we could find a CARP
919 * interface of the parent that could match
920 * the target IP address, we then drop the
921 * packets, which is delieverd to us through
922 * the parent interface.
933 * (1) Check target IP against our local IPs
935 LIST_FOREACH(iac
, INADDR_HASH(itaddr
.s_addr
), ia_hash
) {
938 /* Skip all ia's which don't match */
939 if (itaddr
.s_addr
!= ia
->ia_addr
.sin_addr
.s_addr
)
943 /* CARP interfaces are checked in (0) */
944 if (ia
->ia_ifp
->if_type
== IFT_CARP
)
948 if (ifp
->if_bridge
&& ia
->ia_ifp
&&
949 ifp
->if_bridge
== ia
->ia_ifp
->if_bridge
) {
950 ifp
= ether_bridge_interface(ifp
);
953 if (ia
->ia_ifp
&& ia
->ia_ifp
->if_bridge
&&
954 ether_bridge_interface(ia
->ia_ifp
) == ifp
) {
957 if (ifp
->if_bridge
&& ether_bridge_interface(ifp
) ==
961 if (ia
->ia_ifp
== ifp
) {
967 * (2) Check sender IP against our local IPs
969 LIST_FOREACH(iac
, INADDR_HASH(isaddr
.s_addr
), ia_hash
) {
972 /* Skip all ia's which don't match */
973 if (isaddr
.s_addr
!= ia
->ia_addr
.sin_addr
.s_addr
)
976 if (ifp
->if_bridge
&& ia
->ia_ifp
&&
977 ifp
->if_bridge
== ia
->ia_ifp
->if_bridge
) {
978 ifp
= ether_bridge_interface(ifp
);
981 if (ia
->ia_ifp
&& ia
->ia_ifp
->if_bridge
&&
982 ether_bridge_interface(ia
->ia_ifp
) == ifp
) {
985 if (ifp
->if_bridge
&& ether_bridge_interface(ifp
) ==
990 if (ia
->ia_ifp
== ifp
)
995 * No match, use the first inet address on the receive interface
996 * as a dummy address for the rest of the function.
998 TAILQ_FOREACH(ifac
, &ifp
->if_addrheads
[mycpuid
], ifa_link
) {
999 struct ifaddr
*ifa
= ifac
->ifa
;
1001 if (ifa
->ifa_addr
&& ifa
->ifa_addr
->sa_family
== AF_INET
) {
1008 * If we got here, we didn't find any suitable interface,
1009 * so drop the packet.
1016 enaddr
= (uint8_t *)IF_LLADDR(ifp
);
1017 myaddr
= ia
->ia_addr
.sin_addr
;
1018 if (!bcmp(ar_sha(ah
), enaddr
, ifp
->if_addrlen
)) {
1019 m_freem(m
); /* it's from me, ignore it. */
1022 if (!bcmp(ar_sha(ah
), ifp
->if_broadcastaddr
, ifp
->if_addrlen
)) {
1024 "arp: link address is broadcast for IP address %s!\n",
1025 kinet_ntoa(isaddr
, sbuf
));
1029 if (isaddr
.s_addr
== myaddr
.s_addr
&& myaddr
.s_addr
!= 0) {
1030 hexncpy((u_char
*)ar_sha(ah
), ifp
->if_addrlen
,
1031 hexstr
, HEX_NCPYLEN(ifp
->if_addrlen
), ":");
1033 "arp: %s is using my IP address %s!\n",
1034 hexstr
, kinet_ntoa(isaddr
, sbuf
));
1038 if (ifp
->if_flags
& IFF_STATICARP
)
1042 * When arp_restricted_match is true and the ARP response is not
1043 * specifically targetted to me, ignore it. Otherwise the entry
1044 * timeout may be updated for an old MAC.
1046 if (arp_restricted_match
&& itaddr
.s_addr
!= myaddr
.s_addr
) {
1052 * Update all CPU's routing tables with this ARP packet.
1054 * However, we only need to generate rtmsg on CPU0.
1057 changed
= arp_update_oncpu(m
, isaddr
.s_addr
,
1058 itaddr
.s_addr
== myaddr
.s_addr
,
1059 RTL_REPORTMSG
, TRUE
);
1061 if (netisr_ncpus
> 1 && changed
) {
1062 struct netmsg_inarp
*msg
= &m
->m_hdr
.mh_arpmsg
;
1064 netmsg_init(&msg
->base
, NULL
, &netisr_apanic_rport
,
1065 0, arp_update_msghandler
);
1067 msg
->saddr
= isaddr
.s_addr
;
1068 msg
->taddr
= itaddr
.s_addr
;
1069 msg
->myaddr
= myaddr
.s_addr
;
1070 lwkt_sendmsg(netisr_cpuport(1), &msg
->base
.lmsg
);
1076 * Just return here; after all CPUs's routing tables are
1077 * properly updated by this ARP packet, an ARP reply will
1078 * be generated if appropriate.
1082 in_arpreply(m
, itaddr
.s_addr
, myaddr
.s_addr
);
1086 arp_reply_msghandler(netmsg_t msg
)
1088 struct netmsg_inarp
*rmsg
= (struct netmsg_inarp
*)msg
;
1090 in_arpreply(rmsg
->m
, rmsg
->taddr
, rmsg
->myaddr
);
1091 /* Don't reply this netmsg; netmsg_inarp is embedded in mbuf */
1095 arp_update_msghandler(netmsg_t msg
)
1097 struct netmsg_inarp
*rmsg
= (struct netmsg_inarp
*)msg
;
1100 ASSERT_NETISR_NCPUS(mycpuid
);
1103 * This message handler will be called on all of the APs;
1104 * no need to generate rtmsg on them.
1106 KASSERT(mycpuid
> 0, ("arp update msg on cpu%d", mycpuid
));
1107 arp_update_oncpu(rmsg
->m
, rmsg
->saddr
,
1108 rmsg
->taddr
== rmsg
->myaddr
,
1109 RTL_DONTREPORT
, FALSE
);
1111 nextcpu
= mycpuid
+ 1;
1112 if (nextcpu
< netisr_ncpus
) {
1113 lwkt_forwardmsg(netisr_cpuport(nextcpu
), &rmsg
->base
.lmsg
);
1115 struct mbuf
*m
= rmsg
->m
;
1116 in_addr_t saddr
= rmsg
->saddr
;
1117 in_addr_t taddr
= rmsg
->taddr
;
1118 in_addr_t myaddr
= rmsg
->myaddr
;
1121 * Dispatch this mbuf to netisr0 to perform ARP reply,
1123 * NOTE: netmsg_inarp is embedded in this mbuf.
1125 netmsg_init(&rmsg
->base
, NULL
, &netisr_apanic_rport
,
1126 0, arp_reply_msghandler
);
1128 rmsg
->saddr
= saddr
;
1129 rmsg
->taddr
= taddr
;
1130 rmsg
->myaddr
= myaddr
;
1131 lwkt_sendmsg(netisr_cpuport(0), &rmsg
->base
.lmsg
);
1136 in_arpreply(struct mbuf
*m
, in_addr_t taddr
, in_addr_t myaddr
)
1138 struct ifnet
*ifp
= m
->m_pkthdr
.rcvif
;
1139 const uint8_t *enaddr
;
1142 struct ether_header
*eh
;
1146 ah
= mtod(m
, struct arphdr
*);
1147 if (ntohs(ah
->ar_op
) != ARPOP_REQUEST
) {
1152 enaddr
= (const uint8_t *)IF_LLADDR(ifp
);
1153 if (taddr
== myaddr
) {
1154 /* I am the target */
1155 memcpy(ar_tha(ah
), ar_sha(ah
), ah
->ar_hln
);
1156 memcpy(ar_sha(ah
), enaddr
, ah
->ar_hln
);
1158 struct llinfo_arp
*la
;
1161 la
= arplookup(taddr
, FALSE
, RTL_DONTREPORT
, SIN_PROXY
);
1163 struct sockaddr_in sin
;
1165 char tbuf
[INET_ADDRSTRLEN
];
1168 if (!arp_proxyall
) {
1173 bzero(&sin
, sizeof sin
);
1174 sin
.sin_family
= AF_INET
;
1175 sin
.sin_len
= sizeof sin
;
1176 sin
.sin_addr
.s_addr
= taddr
;
1178 rt
= rtpurelookup((struct sockaddr
*)&sin
);
1185 * Don't send proxies for nodes on the same interface
1186 * as this one came out of, or we'll get into a fight
1187 * over who claims what Ether address.
1189 if (rt
->rt_ifp
== ifp
) {
1193 memcpy(ar_tha(ah
), ar_sha(ah
), ah
->ar_hln
);
1194 memcpy(ar_sha(ah
), enaddr
, ah
->ar_hln
);
1196 kprintf("arp: proxying for %s\n",
1197 kinet_ntoa(itaddr
, tbuf
));
1200 struct sockaddr_dl
*sdl
;
1203 memcpy(ar_tha(ah
), ar_sha(ah
), ah
->ar_hln
);
1204 sdl
= SDL(rt
->rt_gateway
);
1205 memcpy(ar_sha(ah
), LLADDR(sdl
), ah
->ar_hln
);
1209 memcpy(ar_tpa(ah
), ar_spa(ah
), ah
->ar_pln
);
1210 memcpy(ar_spa(ah
), &taddr
, ah
->ar_pln
);
1211 ah
->ar_op
= htons(ARPOP_REPLY
);
1212 ah
->ar_pro
= htons(ETHERTYPE_IP
); /* let's be sure! */
1213 switch (ifp
->if_type
) {
1216 * May not be correct for types not explictly
1217 * listed, but it is our best guess.
1220 eh
= (struct ether_header
*)sa
.sa_data
;
1221 memcpy(eh
->ether_dhost
, ar_tha(ah
), sizeof eh
->ether_dhost
);
1222 eh
->ether_type
= htons(ETHERTYPE_ARP
);
1225 sa
.sa_family
= AF_UNSPEC
;
1226 sa
.sa_len
= sizeof sa
;
1227 ifp
->if_output(ifp
, m
, &sa
, NULL
);
1233 * Free an arp entry. If the arp entry is actively referenced or represents
1234 * a static entry we only clear it back to an unresolved state, otherwise
1235 * we destroy the entry entirely.
1237 * Note that static entries are created when route add ... -interface is used
1238 * to create an interface route to a (direct) destination.
1241 arptfree(struct llinfo_arp
*la
)
1243 struct rtentry
*rt
= la
->la_rt
;
1244 struct sockaddr_dl
*sdl
;
1248 sdl
= SDL(rt
->rt_gateway
);
1250 ((rt
->rt_refcnt
> 0 && sdl
->sdl_family
== AF_LINK
) ||
1251 (rt
->rt_flags
& RTF_STATIC
))) {
1253 la
->la_preempt
= la
->la_asked
= 0;
1254 rt
->rt_flags
&= ~RTF_REJECT
;
1257 rtrequest(RTM_DELETE
, rt_key(rt
), NULL
, rt_mask(rt
), 0, NULL
);
1261 * Lookup or enter a new address in arptab.
1263 static struct llinfo_arp
*
1264 arplookup(in_addr_t addr
, boolean_t create
, boolean_t generate_report
,
1268 struct sockaddr_inarp sin
= { sizeof sin
, AF_INET
};
1269 const char *why
= NULL
;
1271 /* Check ARP probes, e.g. from Cisco switches. */
1272 if (addr
== INADDR_ANY
&& arp_ignore_probes
)
1275 sin
.sin_addr
.s_addr
= addr
;
1276 sin
.sin_other
= proxy
? SIN_PROXY
: 0;
1278 rt
= _rtlookup((struct sockaddr
*)&sin
,
1279 generate_report
, RTL_DOCLONE
);
1281 rt
= rtpurelookup((struct sockaddr
*)&sin
);
1287 if (rt
->rt_flags
& RTF_GATEWAY
)
1288 why
= "host is not on local network";
1289 else if (!(rt
->rt_flags
& RTF_LLINFO
))
1290 why
= "could not allocate llinfo";
1291 else if (rt
->rt_gateway
->sa_family
!= AF_LINK
)
1292 why
= "gateway route is not ours";
1295 if (create
&& log_arp_creation_failure
) {
1296 char abuf
[INET_ADDRSTRLEN
];
1298 log(LOG_DEBUG
, "arplookup %s failed: %s\n",
1299 kinet_ntoa(sin
.sin_addr
, abuf
), why
);
1301 if (rt
->rt_refcnt
<= 0 && (rt
->rt_flags
& RTF_WASCLONED
)) {
1302 /* No references to this route. Purge it. */
1303 rtrequest(RTM_DELETE
, rt_key(rt
), rt
->rt_gateway
,
1304 rt_mask(rt
), rt
->rt_flags
, NULL
);
1308 return (rt
->rt_llinfo
);
1312 arp_ifinit(struct ifnet
*ifp
, struct ifaddr
*ifa
)
1314 ifa
->ifa_rtrequest
= arp_rtrequest
;
1315 ifa
->ifa_flags
|= RTF_CLONING
;
1319 arp_gratuitous(struct ifnet
*ifp
, struct ifaddr
*ifa
)
1321 if (IA_SIN(ifa
)->sin_addr
.s_addr
!= INADDR_ANY
) {
1322 if (IN_NETISR_NCPUS(mycpuid
)) {
1323 arprequest(ifp
, &IA_SIN(ifa
)->sin_addr
,
1324 &IA_SIN(ifa
)->sin_addr
, NULL
);
1326 arprequest_async(ifp
, &IA_SIN(ifa
)->sin_addr
,
1327 &IA_SIN(ifa
)->sin_addr
, NULL
);
1333 arp_ifaddr(void *arg __unused
, struct ifnet
*ifp
,
1334 enum ifaddr_event event
, struct ifaddr
*ifa
)
1336 if (ifa
->ifa_rtrequest
!= arp_rtrequest
) /* XXX need a generic way */
1338 if (ifa
->ifa_addr
->sa_family
!= AF_INET
)
1340 if (event
== IFADDR_EVENT_DELETE
)
1344 * - CARP interfaces will take care of gratuitous ARP themselves.
1345 * - If we are the CARP interface's parent, don't send gratuitous
1346 * ARP to avoid unnecessary confusion.
1349 if (ifp
->if_type
!= IFT_CARP
&& ifp
->if_carp
== NULL
)
1352 arp_gratuitous(ifp
, ifa
);
1357 arp_init_dispatch(netmsg_t nm
)
1359 struct arp_pcpu_data
*ad
;
1361 ASSERT_NETISR_NCPUS(mycpuid
);
1363 ad
= kmalloc(sizeof(*ad
), M_ARP
, M_WAITOK
| M_ZERO
);
1365 LIST_INIT(&ad
->llinfo_list
);
1366 callout_init_mp(&ad
->timer_ch
);
1367 netmsg_init(&ad
->timer_nmsg
, NULL
, &netisr_adone_rport
,
1368 MSGF_PRIORITY
, arptimer_dispatch
);
1369 ad
->timer_nmsg
.lmsg
.u
.ms_resultp
= ad
;
1371 arp_data
[mycpuid
] = ad
;
1373 callout_reset(&ad
->timer_ch
, hz
, arptimer
, &ad
->timer_nmsg
);
1375 netisr_forwardmsg(&nm
->base
, mycpuid
+ 1);
1381 struct netmsg_base nm
;
1383 netmsg_init(&nm
, NULL
, &curthread
->td_msgport
, 0, arp_init_dispatch
);
1384 netisr_domsg_global(&nm
);
1386 netisr_register(NETISR_ARP
, arpintr
, NULL
);
1388 EVENTHANDLER_REGISTER(ifaddr_event
, arp_ifaddr
, NULL
,
1389 EVENTHANDLER_PRI_LAST
);
1391 SYSINIT(arp
, SI_SUB_PROTO_DOMAIN
, SI_ORDER_ANY
, arp_init
, 0);