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.
15 * 3. Neither the name of The DragonFly Project nor the names of its
16 * contributors may be used to endorse or promote products derived
17 * from this software without specific, prior written permission.
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21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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38 * modification, are permitted provided that the following conditions
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50 * may be used to endorse or promote products derived from this software
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62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 1.57 2008/10/07 22:30:31 thomas 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>
91 #include <net/if_dl.h>
92 #include <net/if_types.h>
93 #include <net/route.h>
94 #include <net/netisr.h>
95 #include <net/if_llc.h>
97 #include <netinet/in.h>
98 #include <netinet/in_var.h>
99 #include <netinet/if_ether.h>
101 #include <sys/thread2.h>
102 #include <sys/msgport2.h>
103 #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 static int arp_mpsafe
= 0;
151 TUNABLE_INT("net.link.ether.inet.arp_mpsafe", &arp_mpsafe
);
153 static void arp_rtrequest(int, struct rtentry
*, struct rt_addrinfo
*);
154 static void arprequest(struct ifnet
*, struct in_addr
*, struct in_addr
*,
156 static void arprequest_async(struct ifnet
*, struct in_addr
*,
157 struct in_addr
*, const u_char
*);
158 static void arpintr(struct netmsg
*);
159 static void arptfree(struct llinfo_arp
*);
160 static void arptimer(void *);
161 static struct llinfo_arp
*
162 arplookup(in_addr_t
, boolean_t
, boolean_t
);
164 static void in_arpinput(struct mbuf
*);
167 static struct callout arptimer_ch
[MAXCPU
];
170 * Timeout routine. Age arp_tab entries periodically.
174 arptimer(void *ignored_arg
)
176 struct llinfo_arp
*la
, *nla
;
179 LIST_FOREACH_MUTABLE(la
, &llinfo_arp_list
[mycpuid
], la_le
, nla
) {
180 if (la
->la_rt
->rt_expire
&& la
->la_rt
->rt_expire
<= time_second
)
183 callout_reset(&arptimer_ch
[mycpuid
], arpt_prune
* hz
, arptimer
, NULL
);
188 * Parallel to llc_rtrequest.
191 arp_rtrequest(int req
, struct rtentry
*rt
, struct rt_addrinfo
*info
)
193 struct sockaddr
*gate
= rt
->rt_gateway
;
194 struct llinfo_arp
*la
= rt
->rt_llinfo
;
196 struct sockaddr_dl null_sdl
= { sizeof null_sdl
, AF_LINK
};
197 static boolean_t arpinit_done
[MAXCPU
];
199 if (!arpinit_done
[mycpuid
]) {
200 arpinit_done
[mycpuid
] = TRUE
;
201 callout_init(&arptimer_ch
[mycpuid
]);
202 callout_reset(&arptimer_ch
[mycpuid
], hz
, arptimer
, NULL
);
204 if (rt
->rt_flags
& RTF_GATEWAY
)
210 * XXX: If this is a manually added route to interface
211 * such as older version of routed or gated might provide,
212 * restore cloning bit.
214 if (!(rt
->rt_flags
& RTF_HOST
) &&
215 SIN(rt_mask(rt
))->sin_addr
.s_addr
!= 0xffffffff)
216 rt
->rt_flags
|= RTF_CLONING
;
217 if (rt
->rt_flags
& RTF_CLONING
) {
219 * Case 1: This route should come from a route to iface.
221 rt_setgate(rt
, rt_key(rt
),
222 (struct sockaddr
*)&null_sdl
);
223 gate
= rt
->rt_gateway
;
224 SDL(gate
)->sdl_type
= rt
->rt_ifp
->if_type
;
225 SDL(gate
)->sdl_index
= rt
->rt_ifp
->if_index
;
226 rt
->rt_expire
= time_second
;
229 /* Announce a new entry if requested. */
230 if (rt
->rt_flags
& RTF_ANNOUNCE
) {
231 arprequest_async(rt
->rt_ifp
,
232 &SIN(rt_key(rt
))->sin_addr
,
233 &SIN(rt_key(rt
))->sin_addr
,
238 if (gate
->sa_family
!= AF_LINK
||
239 gate
->sa_len
< sizeof(struct sockaddr_dl
)) {
240 log(LOG_DEBUG
, "arp_rtrequest: bad gateway value\n");
243 SDL(gate
)->sdl_type
= rt
->rt_ifp
->if_type
;
244 SDL(gate
)->sdl_index
= rt
->rt_ifp
->if_index
;
246 break; /* This happens on a route change */
248 * Case 2: This route may come from cloning, or a manual route
249 * add with a LL address.
251 R_Malloc(la
, struct llinfo_arp
*, sizeof *la
);
254 log(LOG_DEBUG
, "arp_rtrequest: malloc failed\n");
257 bzero(la
, sizeof *la
);
259 rt
->rt_flags
|= RTF_LLINFO
;
260 LIST_INSERT_HEAD(&llinfo_arp_list
[mycpuid
], la
, la_le
);
264 * This keeps the multicast addresses from showing up
265 * in `arp -a' listings as unresolved. It's not actually
266 * functional. Then the same for broadcast.
268 if (IN_MULTICAST(ntohl(SIN(rt_key(rt
))->sin_addr
.s_addr
))) {
269 ETHER_MAP_IP_MULTICAST(&SIN(rt_key(rt
))->sin_addr
,
271 SDL(gate
)->sdl_alen
= 6;
274 if (in_broadcast(SIN(rt_key(rt
))->sin_addr
, rt
->rt_ifp
)) {
275 memcpy(LLADDR(SDL(gate
)), rt
->rt_ifp
->if_broadcastaddr
,
276 rt
->rt_ifp
->if_addrlen
);
277 SDL(gate
)->sdl_alen
= rt
->rt_ifp
->if_addrlen
;
282 if (SIN(rt_key(rt
))->sin_addr
.s_addr
==
283 (IA_SIN(rt
->rt_ifa
))->sin_addr
.s_addr
) {
285 * This test used to be
286 * if (loif.if_flags & IFF_UP)
287 * It allowed local traffic to be forced
288 * through the hardware by configuring the
289 * loopback down. However, it causes problems
290 * during network configuration for boards
291 * that can't receive packets they send. It
292 * is now necessary to clear "useloopback" and
293 * remove the route to force traffic out to
297 bcopy(IF_LLADDR(rt
->rt_ifp
), LLADDR(SDL(gate
)),
298 SDL(gate
)->sdl_alen
= rt
->rt_ifp
->if_addrlen
);
307 LIST_REMOVE(la
, la_le
);
308 rt
->rt_llinfo
= NULL
;
309 rt
->rt_flags
&= ~RTF_LLINFO
;
310 if (la
->la_hold
!= NULL
)
311 m_freem(la
->la_hold
);
318 arpreq_alloc(struct ifnet
*ifp
, struct in_addr
*sip
, struct in_addr
*tip
,
319 const u_char
*enaddr
)
325 if ((m
= m_gethdr(MB_DONTWAIT
, MT_DATA
)) == NULL
)
327 m
->m_pkthdr
.rcvif
= NULL
;
329 switch (ifp
->if_type
) {
332 * This may not be correct for types not explicitly
333 * listed, but this is our best guess
336 ar_hrd
= htons(ARPHRD_ETHER
);
338 m
->m_len
= arphdr_len2(ifp
->if_addrlen
, sizeof(struct in_addr
));
339 m
->m_pkthdr
.len
= m
->m_len
;
340 MH_ALIGN(m
, m
->m_len
);
342 ah
= mtod(m
, struct arphdr
*);
347 ah
->ar_pro
= htons(ETHERTYPE_IP
);
348 ah
->ar_hln
= ifp
->if_addrlen
; /* hardware address length */
349 ah
->ar_pln
= sizeof(struct in_addr
); /* protocol address length */
350 ah
->ar_op
= htons(ARPOP_REQUEST
);
351 memcpy(ar_sha(ah
), enaddr
, ah
->ar_hln
);
352 memset(ar_tha(ah
), 0, ah
->ar_hln
);
353 memcpy(ar_spa(ah
), sip
, ah
->ar_pln
);
354 memcpy(ar_tpa(ah
), tip
, ah
->ar_pln
);
360 arpreq_send(struct ifnet
*ifp
, struct mbuf
*m
)
363 struct ether_header
*eh
;
365 switch (ifp
->if_type
) {
368 * This may not be correct for types not explicitly
369 * listed, but this is our best guess
372 eh
= (struct ether_header
*)sa
.sa_data
;
373 /* if_output() will not swap */
374 eh
->ether_type
= htons(ETHERTYPE_ARP
);
375 memcpy(eh
->ether_dhost
, ifp
->if_broadcastaddr
, ifp
->if_addrlen
);
379 sa
.sa_family
= AF_UNSPEC
;
380 sa
.sa_len
= sizeof(sa
);
381 ifp
->if_output(ifp
, m
, &sa
, NULL
);
385 arpreq_send_handler(struct netmsg
*nmsg
)
387 struct mbuf
*m
= ((struct netmsg_packet
*)nmsg
)->nm_packet
;
388 struct ifnet
*ifp
= nmsg
->nm_lmsg
.u
.ms_resultp
;
391 /* nmsg was embedded in the mbuf, do not reply! */
395 * Broadcast an ARP request. Caller specifies:
396 * - arp header source ip address
397 * - arp header target ip address
398 * - arp header source ethernet address
400 * NOTE: Caller MUST NOT hold ifp's serializer
403 arprequest(struct ifnet
*ifp
, struct in_addr
*sip
, struct in_addr
*tip
,
404 const u_char
*enaddr
)
408 m
= arpreq_alloc(ifp
, sip
, tip
, enaddr
);
415 * Same as arprequest(), except:
416 * - Caller is allowed to hold ifp's serializer
417 * - Network output is done in TDF_NETWORK kernel thread
420 arprequest_async(struct ifnet
*ifp
, struct in_addr
*sip
, struct in_addr
*tip
,
421 const u_char
*enaddr
)
424 struct netmsg_packet
*pmsg
;
426 m
= arpreq_alloc(ifp
, sip
, tip
, enaddr
);
430 pmsg
= &m
->m_hdr
.mh_netmsg
;
431 netmsg_init(&pmsg
->nm_netmsg
, &netisr_apanic_rport
, 0,
432 arpreq_send_handler
);
434 pmsg
->nm_netmsg
.nm_lmsg
.u
.ms_resultp
= ifp
;
436 lwkt_sendmsg(cpu_portfn(mycpuid
), &pmsg
->nm_netmsg
.nm_lmsg
);
440 * Resolve an IP address into an ethernet address. If success,
441 * desten is filled in. If there is no entry in arptab,
442 * set one up and broadcast a request for the IP address.
443 * Hold onto this mbuf and resend it once the address
444 * is finally resolved. A return value of 1 indicates
445 * that desten has been filled in and the packet should be sent
446 * normally; a 0 return indicates that the packet has been
447 * taken over here, either now or for later transmission.
450 arpresolve(struct ifnet
*ifp
, struct rtentry
*rt0
, struct mbuf
*m
,
451 struct sockaddr
*dst
, u_char
*desten
)
454 struct llinfo_arp
*la
= NULL
;
455 struct sockaddr_dl
*sdl
;
457 if (m
->m_flags
& M_BCAST
) { /* broadcast */
458 memcpy(desten
, ifp
->if_broadcastaddr
, ifp
->if_addrlen
);
461 if (m
->m_flags
& M_MCAST
) {/* multicast */
462 ETHER_MAP_IP_MULTICAST(&SIN(dst
)->sin_addr
, desten
);
466 if (rt_llroute(dst
, rt0
, &rt
) != 0) {
473 la
= arplookup(SIN(dst
)->sin_addr
.s_addr
, TRUE
, FALSE
);
477 if (la
== NULL
|| rt
== NULL
) {
478 log(LOG_DEBUG
, "arpresolve: can't allocate llinfo for %s%s%s\n",
479 inet_ntoa(SIN(dst
)->sin_addr
), la
? "la" : " ",
484 sdl
= SDL(rt
->rt_gateway
);
486 * Check the address family and length is valid, the address
487 * is resolved; otherwise, try to resolve.
489 if ((rt
->rt_expire
== 0 || rt
->rt_expire
> time_second
) &&
490 sdl
->sdl_family
== AF_LINK
&& sdl
->sdl_alen
!= 0) {
492 * If entry has an expiry time and it is approaching,
493 * see if we need to send an ARP request within this
494 * arpt_down interval.
496 if ((rt
->rt_expire
!= 0) &&
497 (time_second
+ la
->la_preempt
> rt
->rt_expire
)) {
499 &SIN(rt
->rt_ifa
->ifa_addr
)->sin_addr
,
505 bcopy(LLADDR(sdl
), desten
, sdl
->sdl_alen
);
509 * If ARP is disabled on this interface, stop.
511 * Probably should not allocate empty llinfo struct if we are
512 * not going to be sending out an arp request.
514 if (ifp
->if_flags
& IFF_NOARP
) {
519 * There is an arptab entry, but no ethernet address
520 * response yet. Replace the held mbuf with this
523 if (la
->la_hold
!= NULL
)
524 m_freem(la
->la_hold
);
526 if (rt
->rt_expire
|| ((rt
->rt_flags
& RTF_STATIC
) && !sdl
->sdl_alen
)) {
527 rt
->rt_flags
&= ~RTF_REJECT
;
528 if (la
->la_asked
== 0 || rt
->rt_expire
!= time_second
) {
529 rt
->rt_expire
= time_second
;
530 if (la
->la_asked
++ < arp_maxtries
) {
532 &SIN(rt
->rt_ifa
->ifa_addr
)->sin_addr
,
536 rt
->rt_flags
|= RTF_REJECT
;
537 rt
->rt_expire
+= arpt_down
;
539 la
->la_preempt
= arp_maxtries
;
547 * Common length and type checks are done here,
548 * then the protocol-specific routine is called.
551 arpintr(struct netmsg
*msg
)
553 struct mbuf
*m
= ((struct netmsg_packet
*)msg
)->nm_packet
;
557 if (m
->m_len
< sizeof(struct arphdr
) &&
558 (m
= m_pullup(m
, sizeof(struct arphdr
))) == NULL
) {
559 log(LOG_ERR
, "arp: runt packet -- m_pullup failed\n");
562 ar
= mtod(m
, struct arphdr
*);
564 ar_hrd
= ntohs(ar
->ar_hrd
);
565 if (ar_hrd
!= ARPHRD_ETHER
&& ar_hrd
!= ARPHRD_IEEE802
) {
566 log(LOG_ERR
, "arp: unknown hardware address format (0x%2D)\n",
567 (unsigned char *)&ar
->ar_hrd
, "");
572 if (m
->m_pkthdr
.len
< arphdr_len(ar
)) {
573 if ((m
= m_pullup(m
, arphdr_len(ar
))) == NULL
) {
574 log(LOG_ERR
, "arp: runt packet\n");
577 ar
= mtod(m
, struct arphdr
*);
580 switch (ntohs(ar
->ar_pro
)) {
588 /* msg was embedded in the mbuf, do not reply! */
593 * ARP for Internet protocols on 10 Mb/s Ethernet.
594 * Algorithm is that given in RFC 826.
595 * In addition, a sanity check is performed on the sender
596 * protocol address, to catch impersonators.
597 * We no longer handle negotiations for use of trailer protocol:
598 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent
599 * along with IP replies if we wanted trailers sent to us,
600 * and also sent them in response to IP replies.
601 * This allowed either end to announce the desire to receive
603 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either,
604 * but formerly didn't normally send requests.
606 static int log_arp_wrong_iface
= 1;
607 SYSCTL_INT(_net_link_ether_inet
, OID_AUTO
, log_arp_wrong_iface
, CTLFLAG_RW
,
608 &log_arp_wrong_iface
, 0,
609 "log arp packets arriving on the wrong interface");
612 arp_update_oncpu(struct mbuf
*m
, in_addr_t saddr
, boolean_t create
,
615 struct arphdr
*ah
= mtod(m
, struct arphdr
*);
616 struct ifnet
*ifp
= m
->m_pkthdr
.rcvif
;
617 struct llinfo_arp
*la
;
618 struct sockaddr_dl
*sdl
;
621 la
= arplookup(saddr
, create
, FALSE
);
622 if (la
&& (rt
= la
->la_rt
) && (sdl
= SDL(rt
->rt_gateway
))) {
623 struct in_addr isaddr
= { saddr
};
625 /* the following is not an error when doing bridging */
626 if (rt
->rt_ifp
!= ifp
) {
627 if (dologging
&& log_arp_wrong_iface
) {
630 "but got reply from %*D on %s\n",
632 rt
->rt_ifp
->if_xname
,
633 ifp
->if_addrlen
, (u_char
*)ar_sha(ah
), ":",
639 bcmp(ar_sha(ah
), LLADDR(sdl
), sdl
->sdl_alen
)) {
640 if (rt
->rt_expire
!= 0) {
643 "arp: %s moved from %*D to %*D on %s\n",
645 ifp
->if_addrlen
, (u_char
*)LLADDR(sdl
),
646 ":", ifp
->if_addrlen
,
647 (u_char
*)ar_sha(ah
), ":",
653 "arp: %*D attempts to modify "
654 "permanent entry for %s on %s\n",
655 ifp
->if_addrlen
, (u_char
*)ar_sha(ah
),
656 ":", inet_ntoa(isaddr
), ifp
->if_xname
);
662 * sanity check for the address length.
663 * XXX this does not work for protocols with variable address
666 if (dologging
&& sdl
->sdl_alen
&& sdl
->sdl_alen
!= ah
->ar_hln
) {
668 "arp from %*D: new addr len %d, was %d",
669 ifp
->if_addrlen
, (u_char
*) ar_sha(ah
), ":",
670 ah
->ar_hln
, sdl
->sdl_alen
);
672 if (ifp
->if_addrlen
!= ah
->ar_hln
) {
675 "arp from %*D: addr len: new %d, i/f %d "
677 ifp
->if_addrlen
, (u_char
*) ar_sha(ah
), ":",
678 ah
->ar_hln
, ifp
->if_addrlen
);
682 memcpy(LLADDR(sdl
), ar_sha(ah
), sdl
->sdl_alen
= ah
->ar_hln
);
683 if (rt
->rt_expire
!= 0)
684 rt
->rt_expire
= time_second
+ arpt_keep
;
685 rt
->rt_flags
&= ~RTF_REJECT
;
687 la
->la_preempt
= arp_maxtries
;
690 * This particular cpu might have been holding an mbuf
691 * pending ARP resolution. If so, transmit the mbuf now.
693 if (la
->la_hold
!= NULL
) {
694 m_adj(la
->la_hold
, sizeof(struct ether_header
));
695 ifp
->if_output(ifp
, la
->la_hold
, rt_key(rt
), rt
);
703 struct netmsg_arp_update
{
704 struct netmsg netmsg
;
710 static void arp_update_msghandler(struct netmsg
*);
715 * Called from arpintr() - this routine is run from a single cpu.
718 in_arpinput(struct mbuf
*m
)
721 struct ifnet
*ifp
= m
->m_pkthdr
.rcvif
;
722 struct ether_header
*eh
;
724 struct ifaddr_container
*ifac
;
725 struct in_ifaddr_container
*iac
;
726 struct in_ifaddr
*ia
;
728 struct in_addr isaddr
, itaddr
, myaddr
;
730 struct netmsg_arp_update msg
;
732 u_int8_t
*enaddr
= NULL
;
736 req_len
= arphdr_len2(ifp
->if_addrlen
, sizeof(struct in_addr
));
737 if (m
->m_len
< req_len
&& (m
= m_pullup(m
, req_len
)) == NULL
) {
738 log(LOG_ERR
, "in_arp: runt packet -- m_pullup failed\n");
742 ah
= mtod(m
, struct arphdr
*);
743 op
= ntohs(ah
->ar_op
);
744 memcpy(&isaddr
, ar_spa(ah
), sizeof isaddr
);
745 memcpy(&itaddr
, ar_tpa(ah
), sizeof itaddr
);
747 * Check both target and sender IP addresses:
749 * If we receive the packet on the interface owning the address,
750 * then accept the address.
752 * For a bridge, we accept the address if the receive interface and
753 * the interface owning the address are on the same bridge.
754 * (This will change slightly when we have clusters of interfaces).
756 LIST_FOREACH(iac
, INADDR_HASH(itaddr
.s_addr
), ia_hash
) {
759 /* Skip all ia's which don't match */
760 if (itaddr
.s_addr
!= ia
->ia_addr
.sin_addr
.s_addr
)
763 if (ia
->ia_ifp
== ifp
)
766 if (ifp
->if_bridge
&& ia
->ia_ifp
&&
767 ifp
->if_bridge
== ia
->ia_ifp
->if_bridge
)
772 * If the interface does not match, but the recieving interface
773 * is part of carp, we call carp_iamatch to see if this is a
774 * request for the virtual host ip.
775 * XXX: This is really ugly!
777 if (ifp
->if_carp
!= NULL
) {
779 if (ifp
->if_carp
!= NULL
&&
780 carp_iamatch(ifp
->if_carp
, ia
, &isaddr
, &enaddr
)) {
788 LIST_FOREACH(iac
, INADDR_HASH(isaddr
.s_addr
), ia_hash
) {
791 /* Skip all ia's which don't match */
792 if (isaddr
.s_addr
!= ia
->ia_addr
.sin_addr
.s_addr
)
795 if (ia
->ia_ifp
== ifp
)
798 if (ifp
->if_bridge
&& ia
->ia_ifp
&&
799 ifp
->if_bridge
== ia
->ia_ifp
->if_bridge
)
803 * No match, use the first inet address on the receive interface
804 * as a dummy address for the rest of the function.
806 TAILQ_FOREACH(ifac
, &ifp
->if_addrheads
[mycpuid
], ifa_link
) {
807 struct ifaddr
*ifa
= ifac
->ifa
;
809 if (ifa
->ifa_addr
&& ifa
->ifa_addr
->sa_family
== AF_INET
) {
815 * If we got here, we didn't find any suitable interface,
816 * so drop the packet.
823 enaddr
= (u_int8_t
*)IF_LLADDR(ifp
);
824 myaddr
= ia
->ia_addr
.sin_addr
;
825 if (!bcmp(ar_sha(ah
), enaddr
, ifp
->if_addrlen
)) {
826 m_freem(m
); /* it's from me, ignore it. */
829 if (!bcmp(ar_sha(ah
), ifp
->if_broadcastaddr
, ifp
->if_addrlen
)) {
831 "arp: link address is broadcast for IP address %s!\n",
836 if (isaddr
.s_addr
== myaddr
.s_addr
&& myaddr
.s_addr
!= 0) {
838 "arp: %*D is using my IP address %s!\n",
839 ifp
->if_addrlen
, (u_char
*)ar_sha(ah
), ":",
845 netmsg_init(&msg
.netmsg
, &curthread
->td_msgport
, 0,
846 arp_update_msghandler
);
848 msg
.saddr
= isaddr
.s_addr
;
849 msg
.create
= (itaddr
.s_addr
== myaddr
.s_addr
);
850 lwkt_domsg(rtable_portfn(0), &msg
.netmsg
.nm_lmsg
, 0);
852 arp_update_oncpu(m
, isaddr
.s_addr
, (itaddr
.s_addr
== myaddr
.s_addr
),
856 if (op
!= ARPOP_REQUEST
) {
860 if (itaddr
.s_addr
== myaddr
.s_addr
) {
861 /* I am the target */
862 memcpy(ar_tha(ah
), ar_sha(ah
), ah
->ar_hln
);
863 memcpy(ar_sha(ah
), enaddr
, ah
->ar_hln
);
865 struct llinfo_arp
*la
;
867 la
= arplookup(itaddr
.s_addr
, FALSE
, SIN_PROXY
);
869 struct sockaddr_in sin
;
876 bzero(&sin
, sizeof sin
);
877 sin
.sin_family
= AF_INET
;
878 sin
.sin_len
= sizeof sin
;
879 sin
.sin_addr
= itaddr
;
881 rt
= rtpurelookup((struct sockaddr
*)&sin
);
888 * Don't send proxies for nodes on the same interface
889 * as this one came out of, or we'll get into a fight
890 * over who claims what Ether address.
892 if (rt
->rt_ifp
== ifp
) {
896 memcpy(ar_tha(ah
), ar_sha(ah
), ah
->ar_hln
);
897 memcpy(ar_sha(ah
), enaddr
, ah
->ar_hln
);
899 kprintf("arp: proxying for %s\n", inet_ntoa(itaddr
));
902 struct sockaddr_dl
*sdl
;
905 memcpy(ar_tha(ah
), ar_sha(ah
), ah
->ar_hln
);
906 sdl
= SDL(rt
->rt_gateway
);
907 memcpy(ar_sha(ah
), LLADDR(sdl
), ah
->ar_hln
);
911 memcpy(ar_tpa(ah
), ar_spa(ah
), ah
->ar_pln
);
912 memcpy(ar_spa(ah
), &itaddr
, ah
->ar_pln
);
913 ah
->ar_op
= htons(ARPOP_REPLY
);
914 ah
->ar_pro
= htons(ETHERTYPE_IP
); /* let's be sure! */
915 switch (ifp
->if_type
) {
918 * May not be correct for types not explictly
919 * listed, but it is our best guess.
922 eh
= (struct ether_header
*)sa
.sa_data
;
923 memcpy(eh
->ether_dhost
, ar_tha(ah
), sizeof eh
->ether_dhost
);
924 eh
->ether_type
= htons(ETHERTYPE_ARP
);
927 sa
.sa_family
= AF_UNSPEC
;
928 sa
.sa_len
= sizeof sa
;
929 ifp
->if_output(ifp
, m
, &sa
, NULL
);
935 arp_update_msghandler(struct netmsg
*netmsg
)
937 struct netmsg_arp_update
*msg
= (struct netmsg_arp_update
*)netmsg
;
940 arp_update_oncpu(msg
->m
, msg
->saddr
, msg
->create
, mycpuid
== 0);
942 nextcpu
= mycpuid
+ 1;
944 lwkt_forwardmsg(rtable_portfn(nextcpu
), &msg
->netmsg
.nm_lmsg
);
946 lwkt_replymsg(&msg
->netmsg
.nm_lmsg
, 0);
954 * Free an arp entry. If the arp entry is actively referenced or represents
955 * a static entry we only clear it back to an unresolved state, otherwise
956 * we destroy the entry entirely.
958 * Note that static entries are created when route add ... -interface is used
959 * to create an interface route to a (direct) destination.
962 arptfree(struct llinfo_arp
*la
)
964 struct rtentry
*rt
= la
->la_rt
;
965 struct sockaddr_dl
*sdl
;
969 sdl
= SDL(rt
->rt_gateway
);
971 ((rt
->rt_refcnt
> 0 && sdl
->sdl_family
== AF_LINK
) ||
972 (rt
->rt_flags
& RTF_STATIC
))) {
974 la
->la_preempt
= la
->la_asked
= 0;
975 rt
->rt_flags
&= ~RTF_REJECT
;
978 rtrequest(RTM_DELETE
, rt_key(rt
), NULL
, rt_mask(rt
), 0, NULL
);
982 * Lookup or enter a new address in arptab.
984 static struct llinfo_arp
*
985 arplookup(in_addr_t addr
, boolean_t create
, boolean_t proxy
)
988 struct sockaddr_inarp sin
= { sizeof sin
, AF_INET
};
989 const char *why
= NULL
;
991 sin
.sin_addr
.s_addr
= addr
;
992 sin
.sin_other
= proxy
? SIN_PROXY
: 0;
994 rt
= rtlookup((struct sockaddr
*)&sin
);
996 rt
= rtpurelookup((struct sockaddr
*)&sin
);
1001 if (rt
->rt_flags
& RTF_GATEWAY
)
1002 why
= "host is not on local network";
1003 else if (!(rt
->rt_flags
& RTF_LLINFO
))
1004 why
= "could not allocate llinfo";
1005 else if (rt
->rt_gateway
->sa_family
!= AF_LINK
)
1006 why
= "gateway route is not ours";
1010 log(LOG_DEBUG
, "arplookup %s failed: %s\n",
1011 inet_ntoa(sin
.sin_addr
), why
);
1013 if (rt
->rt_refcnt
<= 0 && (rt
->rt_flags
& RTF_WASCLONED
)) {
1014 /* No references to this route. Purge it. */
1015 rtrequest(RTM_DELETE
, rt_key(rt
), rt
->rt_gateway
,
1016 rt_mask(rt
), rt
->rt_flags
, NULL
);
1020 return (rt
->rt_llinfo
);
1024 arp_ifinit(struct ifnet
*ifp
, struct ifaddr
*ifa
)
1026 if (IA_SIN(ifa
)->sin_addr
.s_addr
!= INADDR_ANY
) {
1027 arprequest_async(ifp
, &IA_SIN(ifa
)->sin_addr
,
1028 &IA_SIN(ifa
)->sin_addr
, IF_LLADDR(ifp
));
1030 ifa
->ifa_rtrequest
= arp_rtrequest
;
1031 ifa
->ifa_flags
|= RTF_CLONING
;
1035 arp_ifinit2(struct ifnet
*ifp
, struct ifaddr
*ifa
, u_char
*enaddr
)
1037 if (IA_SIN(ifa
)->sin_addr
.s_addr
!= INADDR_ANY
) {
1038 arprequest_async(ifp
, &IA_SIN(ifa
)->sin_addr
,
1039 &IA_SIN(ifa
)->sin_addr
, enaddr
);
1041 ifa
->ifa_rtrequest
= arp_rtrequest
;
1042 ifa
->ifa_flags
|= RTF_CLONING
;
1051 for (cpu
= 0; cpu
< ncpus2
; cpu
++)
1052 LIST_INIT(&llinfo_arp_list
[cpu
]);
1055 flags
= NETISR_FLAG_MPSAFE
;
1056 kprintf("arp: MPSAFE\n");
1058 flags
= NETISR_FLAG_NOTMPSAFE
;
1060 netisr_register(NETISR_ARP
, cpu0_portfn
, arpintr
, flags
);
1063 SYSINIT(arp
, SI_SUB_PROTO_DOMAIN
, SI_ORDER_ANY
, arp_init
, 0);