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
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58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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
);
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
);
250 gate
= rt
->rt_gateway
;
251 SDL(gate
)->sdl_type
= rt
->rt_ifp
->if_type
;
252 SDL(gate
)->sdl_index
= rt
->rt_ifp
->if_index
;
253 rt
->rt_expire
= time_uptime
;
257 * Announce a new entry if requested, and only announce it
260 if ((rt
->rt_flags
& RTF_ANNOUNCE
) && mycpuid
== 0) {
261 arprequest(rt
->rt_ifp
,
262 &SIN(rt_key(rt
))->sin_addr
,
263 &SIN(rt_key(rt
))->sin_addr
,
268 if (gate
->sa_family
!= AF_LINK
||
269 gate
->sa_len
< sizeof(struct sockaddr_dl
)) {
270 log(LOG_DEBUG
, "arp_rtrequest: bad gateway value\n");
273 SDL(gate
)->sdl_type
= rt
->rt_ifp
->if_type
;
274 SDL(gate
)->sdl_index
= rt
->rt_ifp
->if_index
;
276 break; /* This happens on a route change */
278 * Case 2: This route may come from cloning, or a manual route
279 * add with a LL address.
281 R_Malloc(la
, struct llinfo_arp
*, sizeof *la
);
284 log(LOG_DEBUG
, "arp_rtrequest: malloc failed\n");
287 bzero(la
, sizeof *la
);
289 rt
->rt_flags
|= RTF_LLINFO
;
290 LIST_INSERT_HEAD(&arp_data
[mycpuid
]->llinfo_list
, la
, la_le
);
294 * This keeps the multicast addresses from showing up
295 * in `arp -a' listings as unresolved. It's not actually
296 * functional. Then the same for broadcast.
298 if (IN_MULTICAST(ntohl(SIN(rt_key(rt
))->sin_addr
.s_addr
))) {
299 ETHER_MAP_IP_MULTICAST(&SIN(rt_key(rt
))->sin_addr
,
301 SDL(gate
)->sdl_alen
= 6;
304 if (in_broadcast(SIN(rt_key(rt
))->sin_addr
, rt
->rt_ifp
)) {
305 memcpy(LLADDR(SDL(gate
)), rt
->rt_ifp
->if_broadcastaddr
,
306 rt
->rt_ifp
->if_addrlen
);
307 SDL(gate
)->sdl_alen
= rt
->rt_ifp
->if_addrlen
;
313 * This fixes up the routing interface for local addresses.
314 * The route is adjusted to point at lo0 and the expiration
317 * NOTE: This prevents locally targetted traffic from going
318 * out the hardware interface, which is inefficient
319 * and might not work if the hardware cannot listen
320 * to its own transmitted packets. Setting
321 * net.link.ether.inet.useloopback to 0 will force
322 * packets for local addresses out the hardware (and
323 * it is expected to receive its own packet).
325 * XXX We should just be able to test RTF_LOCAL here instead
326 * of having to compare IPs.
328 if (SIN(rt_key(rt
))->sin_addr
.s_addr
==
329 (IA_SIN(rt
->rt_ifa
))->sin_addr
.s_addr
) {
331 bcopy(IF_LLADDR(rt
->rt_ifp
), LLADDR(SDL(gate
)),
332 SDL(gate
)->sdl_alen
= rt
->rt_ifp
->if_addrlen
);
341 LIST_REMOVE(la
, la_le
);
342 rt
->rt_llinfo
= NULL
;
343 rt
->rt_flags
&= ~RTF_LLINFO
;
344 if (la
->la_hold
!= NULL
)
345 m_freem(la
->la_hold
);
352 arpreq_alloc(struct ifnet
*ifp
, const struct in_addr
*sip
,
353 const struct in_addr
*tip
, const u_char
*enaddr
)
359 if ((m
= m_gethdr(M_NOWAIT
, MT_DATA
)) == NULL
)
361 m
->m_pkthdr
.rcvif
= NULL
;
363 switch (ifp
->if_type
) {
366 * This may not be correct for types not explicitly
367 * listed, but this is our best guess
370 ar_hrd
= htons(ARPHRD_ETHER
);
372 m
->m_len
= arphdr_len2(ifp
->if_addrlen
, sizeof(struct in_addr
));
373 m
->m_pkthdr
.len
= m
->m_len
;
374 MH_ALIGN(m
, m
->m_len
);
376 ah
= mtod(m
, struct arphdr
*);
381 ah
->ar_pro
= htons(ETHERTYPE_IP
);
382 ah
->ar_hln
= ifp
->if_addrlen
; /* hardware address length */
383 ah
->ar_pln
= sizeof(struct in_addr
); /* protocol address length */
384 ah
->ar_op
= htons(ARPOP_REQUEST
);
385 memcpy(ar_sha(ah
), enaddr
, ah
->ar_hln
);
386 memset(ar_tha(ah
), 0, ah
->ar_hln
);
387 memcpy(ar_spa(ah
), sip
, ah
->ar_pln
);
388 memcpy(ar_tpa(ah
), tip
, ah
->ar_pln
);
394 arpreq_send(struct ifnet
*ifp
, struct mbuf
*m
)
397 struct ether_header
*eh
;
399 ASSERT_NETISR_NCPUS(mycpuid
);
401 switch (ifp
->if_type
) {
404 * This may not be correct for types not explicitly
405 * listed, but this is our best guess
408 eh
= (struct ether_header
*)sa
.sa_data
;
409 /* if_output() will not swap */
410 eh
->ether_type
= htons(ETHERTYPE_ARP
);
411 memcpy(eh
->ether_dhost
, ifp
->if_broadcastaddr
, ifp
->if_addrlen
);
415 sa
.sa_family
= AF_UNSPEC
;
416 sa
.sa_len
= sizeof(sa
);
417 ifp
->if_output(ifp
, m
, &sa
, NULL
);
421 arpreq_send_handler(netmsg_t msg
)
423 struct mbuf
*m
= msg
->packet
.nm_packet
;
424 struct ifnet
*ifp
= msg
->lmsg
.u
.ms_resultp
;
427 /* nmsg was embedded in the mbuf, do not reply! */
431 * Broadcast an ARP request. Caller specifies:
432 * - arp header source ip address
433 * - arp header target ip address
434 * - arp header source ethernet address
436 * NOTE: Caller MUST NOT hold ifp's serializer
439 arprequest(struct ifnet
*ifp
, const struct in_addr
*sip
,
440 const struct in_addr
*tip
, const u_char
*enaddr
)
444 ASSERT_NETISR_NCPUS(mycpuid
);
446 if (enaddr
== NULL
) {
447 if (ifp
->if_bridge
) {
448 enaddr
= IF_LLADDR(ether_bridge_interface(ifp
));
450 enaddr
= IF_LLADDR(ifp
);
454 m
= arpreq_alloc(ifp
, sip
, tip
, enaddr
);
461 * Same as arprequest(), except:
462 * - Caller is allowed to hold ifp's serializer
463 * - Network output is done in protocol thead
466 arprequest_async(struct ifnet
*ifp
, const struct in_addr
*sip
,
467 const struct in_addr
*tip
, const u_char
*enaddr
)
470 struct netmsg_packet
*pmsg
;
473 if (enaddr
== NULL
) {
474 if (ifp
->if_bridge
) {
475 enaddr
= IF_LLADDR(ether_bridge_interface(ifp
));
477 enaddr
= IF_LLADDR(ifp
);
480 m
= arpreq_alloc(ifp
, sip
, tip
, enaddr
);
484 pmsg
= &m
->m_hdr
.mh_netmsg
;
485 netmsg_init(&pmsg
->base
, NULL
, &netisr_apanic_rport
,
486 0, arpreq_send_handler
);
488 pmsg
->base
.lmsg
.u
.ms_resultp
= ifp
;
490 if (mycpuid
< netisr_ncpus
)
494 lwkt_sendmsg(netisr_cpuport(cpu
), &pmsg
->base
.lmsg
);
498 * Resolve an IP address into an ethernet address. If success,
499 * desten is filled in. If there is no entry in arptab,
500 * set one up and broadcast a request for the IP address.
501 * Hold onto this mbuf and resend it once the address
502 * is finally resolved. A return value of 1 indicates
503 * that desten has been filled in and the packet should be sent
504 * normally; a 0 return indicates that the packet has been
505 * taken over here, either now or for later transmission.
508 arpresolve(struct ifnet
*ifp
, struct rtentry
*rt0
, struct mbuf
*m
,
509 struct sockaddr
*dst
, u_char
*desten
)
511 struct rtentry
*rt
= NULL
;
512 struct llinfo_arp
*la
= NULL
;
513 struct sockaddr_dl
*sdl
;
515 if (m
->m_flags
& M_BCAST
) { /* broadcast */
516 memcpy(desten
, ifp
->if_broadcastaddr
, ifp
->if_addrlen
);
519 if (m
->m_flags
& M_MCAST
) {/* multicast */
520 ETHER_MAP_IP_MULTICAST(&SIN(dst
)->sin_addr
, desten
);
524 if (rt_llroute(dst
, rt0
, &rt
) != 0) {
531 la
= arplookup(SIN(dst
)->sin_addr
.s_addr
, TRUE
, FALSE
);
535 if (la
== NULL
|| rt
== NULL
) {
536 char addr
[INET_ADDRSTRLEN
];
538 log(LOG_DEBUG
, "arpresolve: can't allocate llinfo for %s%s%s\n",
539 kinet_ntoa(SIN(dst
)->sin_addr
, addr
), la
? "la" : " ",
544 sdl
= SDL(rt
->rt_gateway
);
546 * Check the address family and length is valid, the address
547 * is resolved; otherwise, try to resolve.
549 if ((rt
->rt_expire
== 0 || rt
->rt_expire
> time_uptime
) &&
550 sdl
->sdl_family
== AF_LINK
&& sdl
->sdl_alen
!= 0) {
552 * If entry has an expiry time and it is approaching,
553 * see if we need to send an ARP request within this
554 * arpt_down interval.
556 if ((rt
->rt_expire
!= 0) &&
557 (time_uptime
+ la
->la_preempt
> rt
->rt_expire
)) {
559 &SIN(rt
->rt_ifa
->ifa_addr
)->sin_addr
,
565 bcopy(LLADDR(sdl
), desten
, sdl
->sdl_alen
);
569 * If ARP is disabled or static on this interface, stop.
571 * Probably should not allocate empty llinfo struct if we are
572 * not going to be sending out an arp request.
574 if (ifp
->if_flags
& (IFF_NOARP
| IFF_STATICARP
)) {
579 * There is an arptab entry, but no ethernet address
580 * response yet. Replace the held mbuf with this
583 if (la
->la_hold
!= NULL
)
584 m_freem(la
->la_hold
);
586 if (rt
->rt_expire
|| ((rt
->rt_flags
& RTF_STATIC
) && !sdl
->sdl_alen
)) {
587 rt
->rt_flags
&= ~RTF_REJECT
;
588 if (la
->la_asked
== 0 || rt
->rt_expire
!= time_uptime
) {
589 rt
->rt_expire
= time_uptime
;
591 &SIN(rt
->rt_ifa
->ifa_addr
)->sin_addr
,
594 if (la
->la_asked
++ >= arp_maxtries
) {
595 rt
->rt_expire
+= arpt_down
;
596 la
->la_preempt
= arp_maxtries
;
597 rt_rtmsg(RTM_MISS
, rt
, rt
->rt_ifp
, 0);
605 * Common length and type checks are done here,
606 * then the protocol-specific routine is called.
609 arpintr(netmsg_t msg
)
611 struct mbuf
*m
= msg
->packet
.nm_packet
;
616 if (m
->m_len
< sizeof(struct arphdr
) &&
617 (m
= m_pullup(m
, sizeof(struct arphdr
))) == NULL
) {
618 log(LOG_ERR
, "arp: runt packet -- m_pullup failed\n");
621 ar
= mtod(m
, struct arphdr
*);
623 ar_hrd
= ntohs(ar
->ar_hrd
);
624 if (ar_hrd
!= ARPHRD_ETHER
&& ar_hrd
!= ARPHRD_IEEE802
) {
625 hexncpy((unsigned char *)&ar
->ar_hrd
, 2, hexstr
, 5, NULL
);
626 log(LOG_ERR
, "arp: unknown hardware address format (0x%s)\n",
632 if (m
->m_pkthdr
.len
< arphdr_len(ar
)) {
633 if ((m
= m_pullup(m
, arphdr_len(ar
))) == NULL
) {
634 log(LOG_ERR
, "arp: runt packet\n");
637 ar
= mtod(m
, struct arphdr
*);
640 switch (ntohs(ar
->ar_pro
)) {
648 /* msg was embedded in the mbuf, do not reply! */
653 * ARP for Internet protocols on 10 Mb/s Ethernet.
654 * Algorithm is that given in RFC 826.
655 * In addition, a sanity check is performed on the sender
656 * protocol address, to catch impersonators.
657 * We no longer handle negotiations for use of trailer protocol:
658 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent
659 * along with IP replies if we wanted trailers sent to us,
660 * and also sent them in response to IP replies.
661 * This allowed either end to announce the desire to receive
663 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either,
664 * but formerly didn't normally send requests.
667 static int log_arp_wrong_iface
= 1;
668 static int log_arp_movements
= 1;
669 static int log_arp_permanent_modify
= 1;
670 static int log_arp_creation_failure
= 1;
672 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, log_arp_wrong_iface
, CTLFLAG_RW
,
673 &log_arp_wrong_iface
, 0,
674 "Log arp packets arriving on the wrong interface");
675 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, log_arp_movements
, CTLFLAG_RW
,
676 &log_arp_movements
, 0,
677 "Log arp replies from MACs different than the one in the cache");
678 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, log_arp_permanent_modify
, CTLFLAG_RW
,
679 &log_arp_permanent_modify
, 0,
680 "Log arp replies from MACs different than the one "
681 "in the permanent arp entry");
682 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, log_arp_creation_failure
, CTLFLAG_RW
,
683 &log_arp_creation_failure
, 0, "Log arp creation failure");
686 * Returns non-zero if the routine updated anything.
689 arp_update_oncpu(struct mbuf
*m
, in_addr_t saddr
, boolean_t create
,
692 struct arphdr
*ah
= mtod(m
, struct arphdr
*);
693 struct ifnet
*ifp
= m
->m_pkthdr
.rcvif
;
694 struct llinfo_arp
*la
;
695 struct sockaddr_dl
*sdl
;
698 char sbuf
[INET_ADDRSTRLEN
];
699 int changed
= create
;
701 KASSERT(curthread
->td_type
== TD_TYPE_NETISR
,
702 ("arp update not in netisr"));
704 la
= arplookup(saddr
, create
, FALSE
);
705 if (la
&& (rt
= la
->la_rt
) && (sdl
= SDL(rt
->rt_gateway
))) {
706 struct in_addr isaddr
= { saddr
};
707 int rt_cmd
= sdl
->sdl_alen
== 0 ? RTM_ADD
: RTM_CHANGE
;
708 bool do_rtmsg
= false;
711 * Normally arps coming in on the wrong interface are ignored,
712 * but if we are bridging and the two interfaces belong to
713 * the same bridge, or one is a member of the bridge which
714 * is the other, then it isn't an error.
716 if (rt
->rt_ifp
!= ifp
) {
718 * (1) ifp and rt_ifp both members of same bridge
719 * (2) rt_ifp member of bridge ifp
720 * (3) ifp member of bridge rt_ifp
722 * Always replace rt_ifp with the bridge ifc.
726 if (ifp
->if_bridge
&&
727 rt
->rt_ifp
->if_bridge
== ifp
->if_bridge
) {
728 nifp
= ether_bridge_interface(ifp
);
729 } else if (rt
->rt_ifp
->if_bridge
&&
730 ether_bridge_interface(rt
->rt_ifp
) == ifp
) {
732 } else if (ifp
->if_bridge
&&
733 ether_bridge_interface(ifp
) == rt
->rt_ifp
) {
739 if ((log_arp_wrong_iface
== 1 && nifp
== NULL
) ||
740 log_arp_wrong_iface
== 2) {
741 hexncpy((u_char
*)ar_sha(ah
), ifp
->if_addrlen
,
742 hexstr
[0], HEX_NCPYLEN(ifp
->if_addrlen
), ":");
745 "but got reply from %s on %s\n",
746 kinet_ntoa(isaddr
, sbuf
),
747 rt
->rt_ifp
->if_xname
, hexstr
[0],
754 * nifp is our man! Replace rt_ifp and adjust
757 ifp
= rt
->rt_ifp
= nifp
;
758 if (sdl
->sdl_type
!= ifp
->if_type
) {
759 sdl
->sdl_type
= ifp
->if_type
;
763 if (sdl
->sdl_index
!= ifp
->if_index
) {
764 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
);
797 * sanity check for the address length.
798 * XXX this does not work for protocols with variable address
801 if (dologging
&& sdl
->sdl_alen
&& sdl
->sdl_alen
!= ah
->ar_hln
) {
802 hexncpy((u_char
*)ar_sha(ah
), ifp
->if_addrlen
,
803 hexstr
[0], HEX_NCPYLEN(ifp
->if_addrlen
), ":");
805 "arp from %s: new addr len %d, was %d",
806 hexstr
[0], ah
->ar_hln
, sdl
->sdl_alen
);
808 if (ifp
->if_addrlen
!= ah
->ar_hln
) {
810 hexncpy((u_char
*)ar_sha(ah
), ifp
->if_addrlen
,
811 hexstr
[0], HEX_NCPYLEN(ifp
->if_addrlen
), ":");
813 "arp from %s: addr len: new %d, i/f %d "
814 "(ignored)", hexstr
[0],
815 ah
->ar_hln
, ifp
->if_addrlen
);
819 if (sdl
->sdl_alen
== 0)
821 memcpy(LLADDR(sdl
), ar_sha(ah
), sdl
->sdl_alen
= ah
->ar_hln
);
822 if (rt
->rt_expire
!= 0) {
823 if (rt
->rt_expire
!= time_uptime
+ arpt_keep
&&
824 rt
->rt_expire
!= time_uptime
+ arpt_keep
- 1) {
825 rt
->rt_expire
= time_uptime
+ arpt_keep
;
829 if (rt
->rt_flags
& RTF_REJECT
) {
830 rt
->rt_flags
&= ~RTF_REJECT
;
833 if (la
->la_asked
!= 0) {
837 if (la
->la_preempt
!= arp_maxtries
) {
838 la
->la_preempt
= arp_maxtries
;
843 * This particular cpu might have been holding an mbuf
844 * pending ARP resolution. If so, transmit the mbuf now.
846 if (la
->la_hold
!= NULL
) {
847 struct mbuf
*m
= la
->la_hold
;
850 m_adj(m
, sizeof(struct ether_header
));
851 ifp
->if_output(ifp
, m
, rt_key(rt
), rt
);
855 if (do_rtmsg
&& mycpuid
== 0)
856 rt_rtmsg(rt_cmd
, rt
, rt
->rt_ifp
, 0);
862 * Called from arpintr() - this routine is run from a single cpu.
865 in_arpinput(struct mbuf
*m
)
868 struct ifnet
*ifp
= m
->m_pkthdr
.rcvif
;
869 struct ifaddr_container
*ifac
;
870 struct in_ifaddr_container
*iac
;
871 struct in_ifaddr
*ia
= NULL
;
872 struct in_addr isaddr
, itaddr
, myaddr
;
873 uint8_t *enaddr
= NULL
;
876 char hexstr
[64], sbuf
[INET_ADDRSTRLEN
];
878 req_len
= arphdr_len2(ifp
->if_addrlen
, sizeof(struct in_addr
));
879 if (m
->m_len
< req_len
&& (m
= m_pullup(m
, req_len
)) == NULL
) {
880 log(LOG_ERR
, "in_arp: runt packet -- m_pullup failed\n");
884 ah
= mtod(m
, struct arphdr
*);
885 memcpy(&isaddr
, ar_spa(ah
), sizeof isaddr
);
886 memcpy(&itaddr
, ar_tpa(ah
), sizeof itaddr
);
889 * Check both target and sender IP addresses:
891 * If we receive the packet on the interface owning the address,
892 * then accept the address.
894 * For a bridge, we accept the address if the receive interface and
895 * the interface owning the address are on the same bridge, and
896 * use the bridge MAC as the is-at response. The bridge will be
897 * responsible for handling the packet.
899 * (0) Check target IP against CARP IPs
902 LIST_FOREACH(iac
, INADDR_HASH(itaddr
.s_addr
), ia_hash
) {
903 int is_match
= 0, is_parent
= 0;
907 /* Skip all ia's which don't match */
908 if (itaddr
.s_addr
!= ia
->ia_addr
.sin_addr
.s_addr
)
911 if (ia
->ia_ifp
->if_type
!= IFT_CARP
)
914 if (carp_parent(ia
->ia_ifp
) == ifp
)
916 if (is_parent
|| ia
->ia_ifp
== ifp
)
917 is_match
= carp_iamatch(ia
);
922 * The parent interface will also receive
923 * the ethernet broadcast packets, e.g. ARP
924 * REQUEST, so if we could find a CARP
925 * interface of the parent that could match
926 * the target IP address, we then drop the
927 * packets, which is delieverd to us through
928 * the parent interface.
939 * (1) Check target IP against our local IPs
941 LIST_FOREACH(iac
, INADDR_HASH(itaddr
.s_addr
), ia_hash
) {
944 /* Skip all ia's which don't match */
945 if (itaddr
.s_addr
!= ia
->ia_addr
.sin_addr
.s_addr
)
949 /* CARP interfaces are checked in (0) */
950 if (ia
->ia_ifp
->if_type
== IFT_CARP
)
954 if (ifp
->if_bridge
&& ia
->ia_ifp
&&
955 ifp
->if_bridge
== ia
->ia_ifp
->if_bridge
) {
956 ifp
= ether_bridge_interface(ifp
);
959 if (ia
->ia_ifp
&& ia
->ia_ifp
->if_bridge
&&
960 ether_bridge_interface(ia
->ia_ifp
) == ifp
) {
963 if (ifp
->if_bridge
&& ether_bridge_interface(ifp
) ==
967 if (ia
->ia_ifp
== ifp
) {
973 * (2) Check sender IP against our local IPs
975 LIST_FOREACH(iac
, INADDR_HASH(isaddr
.s_addr
), ia_hash
) {
978 /* Skip all ia's which don't match */
979 if (isaddr
.s_addr
!= ia
->ia_addr
.sin_addr
.s_addr
)
982 if (ifp
->if_bridge
&& ia
->ia_ifp
&&
983 ifp
->if_bridge
== ia
->ia_ifp
->if_bridge
) {
984 ifp
= ether_bridge_interface(ifp
);
987 if (ia
->ia_ifp
&& ia
->ia_ifp
->if_bridge
&&
988 ether_bridge_interface(ia
->ia_ifp
) == ifp
) {
991 if (ifp
->if_bridge
&& ether_bridge_interface(ifp
) ==
996 if (ia
->ia_ifp
== ifp
)
1001 * No match, use the first inet address on the receive interface
1002 * as a dummy address for the rest of the function.
1004 TAILQ_FOREACH(ifac
, &ifp
->if_addrheads
[mycpuid
], ifa_link
) {
1005 struct ifaddr
*ifa
= ifac
->ifa
;
1007 if (ifa
->ifa_addr
&& ifa
->ifa_addr
->sa_family
== AF_INET
) {
1014 * If we got here, we didn't find any suitable interface,
1015 * so drop the packet.
1022 enaddr
= (uint8_t *)IF_LLADDR(ifp
);
1023 myaddr
= ia
->ia_addr
.sin_addr
;
1024 if (!bcmp(ar_sha(ah
), enaddr
, ifp
->if_addrlen
)) {
1025 m_freem(m
); /* it's from me, ignore it. */
1028 if (!bcmp(ar_sha(ah
), ifp
->if_broadcastaddr
, ifp
->if_addrlen
)) {
1030 "arp: link address is broadcast for IP address %s!\n",
1031 kinet_ntoa(isaddr
, sbuf
));
1035 if (isaddr
.s_addr
== myaddr
.s_addr
&& myaddr
.s_addr
!= 0) {
1036 hexncpy((u_char
*)ar_sha(ah
), ifp
->if_addrlen
,
1037 hexstr
, HEX_NCPYLEN(ifp
->if_addrlen
), ":");
1039 "arp: %s is using my IP address %s!\n",
1040 hexstr
, kinet_ntoa(isaddr
, sbuf
));
1044 if (ifp
->if_flags
& IFF_STATICARP
)
1048 * When arp_restricted_match is true and the ARP response is not
1049 * specifically targetted to me, ignore it. Otherwise the entry
1050 * timeout may be updated for an old MAC.
1052 if (arp_restricted_match
&& itaddr
.s_addr
!= myaddr
.s_addr
) {
1058 * Update all CPU's routing tables with this ARP packet.
1060 * However, we only need to generate rtmsg on CPU0.
1063 changed
= arp_update_oncpu(m
, isaddr
.s_addr
,
1064 itaddr
.s_addr
== myaddr
.s_addr
,
1067 if (netisr_ncpus
> 1 && changed
) {
1068 struct netmsg_inarp
*msg
= &m
->m_hdr
.mh_arpmsg
;
1070 netmsg_init(&msg
->base
, NULL
, &netisr_apanic_rport
,
1071 0, arp_update_msghandler
);
1073 msg
->saddr
= isaddr
.s_addr
;
1074 msg
->taddr
= itaddr
.s_addr
;
1075 msg
->myaddr
= myaddr
.s_addr
;
1076 lwkt_sendmsg(netisr_cpuport(1), &msg
->base
.lmsg
);
1082 * Just return here; after all CPUs's routing tables are
1083 * properly updated by this ARP packet, an ARP reply will
1084 * be generated if appropriate.
1088 in_arpreply(m
, itaddr
.s_addr
, myaddr
.s_addr
);
1092 arp_reply_msghandler(netmsg_t msg
)
1094 struct netmsg_inarp
*rmsg
= (struct netmsg_inarp
*)msg
;
1096 in_arpreply(rmsg
->m
, rmsg
->taddr
, rmsg
->myaddr
);
1097 /* Don't reply this netmsg; netmsg_inarp is embedded in mbuf */
1101 arp_update_msghandler(netmsg_t msg
)
1103 struct netmsg_inarp
*rmsg
= (struct netmsg_inarp
*)msg
;
1106 ASSERT_NETISR_NCPUS(mycpuid
);
1109 * This message handler will be called on all of the APs;
1110 * no need to generate rtmsg on them.
1112 KASSERT(mycpuid
> 0, ("arp update msg on cpu%d", mycpuid
));
1113 arp_update_oncpu(rmsg
->m
, rmsg
->saddr
,
1114 rmsg
->taddr
== rmsg
->myaddr
,
1117 nextcpu
= mycpuid
+ 1;
1118 if (nextcpu
< netisr_ncpus
) {
1119 lwkt_forwardmsg(netisr_cpuport(nextcpu
), &rmsg
->base
.lmsg
);
1121 struct mbuf
*m
= rmsg
->m
;
1122 in_addr_t saddr
= rmsg
->saddr
;
1123 in_addr_t taddr
= rmsg
->taddr
;
1124 in_addr_t myaddr
= rmsg
->myaddr
;
1127 * Dispatch this mbuf to netisr0 to perform ARP reply,
1129 * NOTE: netmsg_inarp is embedded in this mbuf.
1131 netmsg_init(&rmsg
->base
, NULL
, &netisr_apanic_rport
,
1132 0, arp_reply_msghandler
);
1134 rmsg
->saddr
= saddr
;
1135 rmsg
->taddr
= taddr
;
1136 rmsg
->myaddr
= myaddr
;
1137 lwkt_sendmsg(netisr_cpuport(0), &rmsg
->base
.lmsg
);
1142 * Reply to an arp request
1145 in_arpreply(struct mbuf
*m
, in_addr_t taddr
, in_addr_t myaddr
)
1147 struct ifnet
*ifp
= m
->m_pkthdr
.rcvif
;
1148 const uint8_t *enaddr
;
1151 struct ether_header
*eh
;
1155 ah
= mtod(m
, struct arphdr
*);
1156 if (ntohs(ah
->ar_op
) != ARPOP_REQUEST
) {
1161 enaddr
= (const uint8_t *)IF_LLADDR(ifp
);
1162 if (taddr
== myaddr
) {
1163 /* I am the target */
1164 memcpy(ar_tha(ah
), ar_sha(ah
), ah
->ar_hln
);
1165 memcpy(ar_sha(ah
), enaddr
, ah
->ar_hln
);
1167 struct llinfo_arp
*la
;
1170 la
= arplookup(taddr
, FALSE
, SIN_PROXY
);
1172 struct sockaddr_in sin
;
1174 char tbuf
[INET_ADDRSTRLEN
];
1177 if (!arp_proxyall
) {
1182 bzero(&sin
, sizeof sin
);
1183 sin
.sin_family
= AF_INET
;
1184 sin
.sin_len
= sizeof sin
;
1185 sin
.sin_addr
.s_addr
= taddr
;
1187 rt
= rtpurelookup((struct sockaddr
*)&sin
);
1195 * Don't send proxies for nodes on the same interface
1196 * as this one came out of, or we'll get into a fight
1197 * over who claims what Ether address.
1199 * If the rt entry is associated with a bridge, we
1200 * count it as the 'same' interface if ifp is
1201 * associated with the bridge.
1203 if (rt
->rt_ifp
== ifp
|| rt
->rt_ifp
== ifp
->if_bridge
) {
1207 memcpy(ar_tha(ah
), ar_sha(ah
), ah
->ar_hln
);
1208 memcpy(ar_sha(ah
), enaddr
, ah
->ar_hln
);
1210 kprintf("arp: proxying for %s\n",
1211 kinet_ntoa(itaddr
, tbuf
));
1214 struct sockaddr_dl
*sdl
;
1217 memcpy(ar_tha(ah
), ar_sha(ah
), ah
->ar_hln
);
1218 sdl
= SDL(rt
->rt_gateway
);
1219 memcpy(ar_sha(ah
), LLADDR(sdl
), ah
->ar_hln
);
1223 memcpy(ar_tpa(ah
), ar_spa(ah
), ah
->ar_pln
);
1224 memcpy(ar_spa(ah
), &taddr
, ah
->ar_pln
);
1225 ah
->ar_op
= htons(ARPOP_REPLY
);
1226 ah
->ar_pro
= htons(ETHERTYPE_IP
); /* let's be sure! */
1227 switch (ifp
->if_type
) {
1230 * May not be correct for types not explictly
1231 * listed, but it is our best guess.
1234 eh
= (struct ether_header
*)sa
.sa_data
;
1235 memcpy(eh
->ether_dhost
, ar_tha(ah
), sizeof eh
->ether_dhost
);
1236 eh
->ether_type
= htons(ETHERTYPE_ARP
);
1239 sa
.sa_family
= AF_UNSPEC
;
1240 sa
.sa_len
= sizeof sa
;
1241 ifp
->if_output(ifp
, m
, &sa
, NULL
);
1247 * Free an arp entry. If the arp entry is actively referenced or represents
1248 * a static entry we only clear it back to an unresolved state, otherwise
1249 * we destroy the entry entirely.
1251 * Note that static entries are created when route add ... -interface is used
1252 * to create an interface route to a (direct) destination.
1255 arptfree(struct llinfo_arp
*la
)
1257 struct rtentry
*rt
= la
->la_rt
, *nrt
;
1258 struct sockaddr_dl
*sdl
;
1263 sdl
= SDL(rt
->rt_gateway
);
1265 ((rt
->rt_refcnt
> 0 && sdl
->sdl_family
== AF_LINK
) ||
1266 (rt
->rt_flags
& RTF_STATIC
))) {
1268 la
->la_preempt
= la
->la_asked
= 0;
1269 rt
->rt_flags
&= ~RTF_REJECT
;
1272 error
= rtrequest(RTM_DELETE
, rt_key(rt
), NULL
, rt_mask(rt
), 0, &nrt
);
1273 if (error
== 0 && nrt
!= NULL
) {
1274 rt_rtmsg(RTM_DELETE
, nrt
, nrt
->rt_ifp
, 0);
1280 * Lookup or enter a new address in arptab.
1282 static struct llinfo_arp
*
1283 arplookup(in_addr_t addr
, boolean_t create
,
1287 struct sockaddr_inarp sin
= { sizeof sin
, AF_INET
};
1288 const char *why
= NULL
;
1290 /* Check ARP probes, e.g. from Cisco switches. */
1291 if (addr
== INADDR_ANY
&& arp_ignore_probes
)
1294 sin
.sin_addr
.s_addr
= addr
;
1295 sin
.sin_other
= proxy
? SIN_PROXY
: 0;
1297 rt
= rtlookup((struct sockaddr
*)&sin
);
1299 rt
= rtpurelookup((struct sockaddr
*)&sin
);
1305 if (rt
->rt_flags
& RTF_GATEWAY
)
1306 why
= "host is not on local network";
1307 else if (!(rt
->rt_flags
& RTF_LLINFO
))
1308 why
= "could not allocate llinfo";
1309 else if (rt
->rt_gateway
->sa_family
!= AF_LINK
)
1310 why
= "gateway route is not ours";
1313 if (create
&& log_arp_creation_failure
) {
1314 char abuf
[INET_ADDRSTRLEN
];
1316 log(LOG_DEBUG
, "arplookup %s failed: %s\n",
1317 kinet_ntoa(sin
.sin_addr
, abuf
), why
);
1319 if (rt
->rt_refcnt
<= 0 && (rt
->rt_flags
& RTF_WASCLONED
)) {
1320 /* No references to this route. Purge it. */
1321 rtrequest(RTM_DELETE
, rt_key(rt
), rt
->rt_gateway
,
1322 rt_mask(rt
), rt
->rt_flags
, NULL
);
1326 return (rt
->rt_llinfo
);
1330 arp_ifinit(struct ifnet
*ifp
, struct ifaddr
*ifa
)
1332 ifa
->ifa_rtrequest
= arp_rtrequest
;
1333 ifa
->ifa_flags
|= RTF_CLONING
;
1337 arp_gratuitous(struct ifnet
*ifp
, struct ifaddr
*ifa
)
1339 if (IA_SIN(ifa
)->sin_addr
.s_addr
!= INADDR_ANY
) {
1340 if (IN_NETISR_NCPUS(mycpuid
)) {
1341 arprequest(ifp
, &IA_SIN(ifa
)->sin_addr
,
1342 &IA_SIN(ifa
)->sin_addr
, NULL
);
1344 arprequest_async(ifp
, &IA_SIN(ifa
)->sin_addr
,
1345 &IA_SIN(ifa
)->sin_addr
, NULL
);
1351 arp_ifaddr(void *arg __unused
, struct ifnet
*ifp
,
1352 enum ifaddr_event event
, struct ifaddr
*ifa
)
1354 if (ifa
->ifa_rtrequest
!= arp_rtrequest
) /* XXX need a generic way */
1356 if (ifa
->ifa_addr
->sa_family
!= AF_INET
)
1358 if (event
== IFADDR_EVENT_DELETE
)
1362 * - CARP interfaces will take care of gratuitous ARP themselves.
1363 * - If we are the CARP interface's parent, don't send gratuitous
1364 * ARP to avoid unnecessary confusion.
1367 if (ifp
->if_type
!= IFT_CARP
&& ifp
->if_carp
== NULL
)
1370 arp_gratuitous(ifp
, ifa
);
1375 arp_init_dispatch(netmsg_t nm
)
1377 struct arp_pcpu_data
*ad
;
1379 ASSERT_NETISR_NCPUS(mycpuid
);
1381 ad
= kmalloc(sizeof(*ad
), M_ARP
, M_WAITOK
| M_ZERO
);
1383 LIST_INIT(&ad
->llinfo_list
);
1384 callout_init_mp(&ad
->timer_ch
);
1385 netmsg_init(&ad
->timer_nmsg
, NULL
, &netisr_adone_rport
,
1386 MSGF_PRIORITY
, arptimer_dispatch
);
1387 ad
->timer_nmsg
.lmsg
.u
.ms_resultp
= ad
;
1389 arp_data
[mycpuid
] = ad
;
1391 callout_reset(&ad
->timer_ch
, hz
, arptimer
, &ad
->timer_nmsg
);
1393 netisr_forwardmsg(&nm
->base
, mycpuid
+ 1);
1399 struct netmsg_base nm
;
1401 netmsg_init(&nm
, NULL
, &curthread
->td_msgport
, 0, arp_init_dispatch
);
1402 netisr_domsg_global(&nm
);
1404 netisr_register(NETISR_ARP
, arpintr
, NULL
);
1406 EVENTHANDLER_REGISTER(ifaddr_event
, arp_ifaddr
, NULL
,
1407 EVENTHANDLER_PRI_LAST
);
1409 SYSINIT(arp
, SI_SUB_PROTO_DOMAIN
, SI_ORDER_ANY
, arp_init
, 0);