1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
87 	ARP_LLINFO_VERIFY,	/* LLE is valid, need refresh */
155  * const int max = fls(INT_MAX / hz) - 1;
172 	"Minimum log(9) level for recording rate limited arp log messages. "
209 	if (lle->la_flags & LLE_STATIC) {  in arptimer()
213 	if (callout_pending(&lle->lle_timer)) {  in arptimer()
232 	ifp = lle->lle_tbl->llt_ifp;  in arptimer()
233 	CURVNET_SET(ifp->if_vnet);  in arptimer()
235 	switch (lle->ln_state) {  in arptimer()
241 		 * Change state and re-schedule ourselves.  in arptimer()
244 		lle->ln_state = ARP_LLINFO_VERIFY;  in arptimer()
245 		callout_schedule(&lle->lle_timer, hz * V_arpt_rexmit);  in arptimer()
250 		if (llentry_get_hittime(lle) > 0 && lle->la_preempt > 0) {  in arptimer()
251 			/* Entry was used, issue refresh request */  in arptimer()
255 			dst = lle->r_l3addr.addr4;  in arptimer()
256 			lle->la_preempt--;  in arptimer()
257 			callout_schedule(&lle->lle_timer, hz * V_arpt_rexmit);  in arptimer()
266 		if (lle->la_expire > time_uptime) {  in arptimer()
267 			callout_schedule(&lle->lle_timer, hz * V_arpt_rexmit);  in arptimer()
278 	if ((lle->la_flags & LLE_DELETED) == 0) {  in arptimer()
281 		if (lle->la_flags & LLE_VALID)  in arptimer()
288 	callout_stop(&lle->lle_timer);  in arptimer()
296 	if (lle->la_flags & LLE_LINKED) {  in arptimer()
298 		lltable_unlink_entry(lle->lle_tbl, lle);  in arptimer()
311  * Stores link-layer header for @ifp in format suitable for if_output()
333 	error = ifp->if_requestencap(ifp, &ereq);  in arp_fillheader()
342  *	- arp header source ip address
343  *	- arp header target ip address
344  *	- arp header source ethernet address
368 		CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {  in arprequest_internal()
369 			if (ifa->ifa_addr->sa_family != AF_INET)  in arprequest_internal()
372 			if (ifa->ifa_carp) {  in arprequest_internal()
375 				sip = &IA_SIN(ifa)->sin_addr;  in arprequest_internal()
378 				sip = &IA_SIN(ifa)->sin_addr;  in arprequest_internal()
381 			if (0 == ((sip->s_addr ^ tip->s_addr) &  in arprequest_internal()
382 			    IA_MASKSIN(ifa)->sin_addr.s_addr))  in arprequest_internal()
395 	m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) +  in arprequest_internal()
396 		2 * ifp->if_addrlen;  in arprequest_internal()
397 	m->m_pkthdr.len = m->m_len;  in arprequest_internal()
398 	M_ALIGN(m, m->m_len);  in arprequest_internal()
400 	bzero((caddr_t)ah, m->m_len);  in arprequest_internal()
404 	ah->ar_pro = htons(ETHERTYPE_IP);  in arprequest_internal()
405 	ah->ar_hln = ifp->if_addrlen;		/* hardware address length */  in arprequest_internal()
406 	ah->ar_pln = sizeof(struct in_addr);	/* protocol address length */  in arprequest_internal()
407 	ah->ar_op = htons(ARPOP_REQUEST);  in arprequest_internal()
408 	bcopy(enaddr, ar_sha(ah), ah->ar_hln);  in arprequest_internal()
409 	bcopy(sip, ar_spa(ah), ah->ar_pln);  in arprequest_internal()
410 	bcopy(tip, ar_tpa(ah), ah->ar_pln);  in arprequest_internal()
429 	m->m_flags |= M_BCAST;  in arprequest_internal()
431 	error = (*ifp->if_output)(ifp, m, &sa, &ro);  in arprequest_internal()
450  * Resolve an IP address into an ethernet address - heavy version.
479 	if (la == NULL && (ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) == 0) {  in arpresolve_full()
486 			    inet_ntoa_r(SIN(dst)->sin_addr, addrbuf),  in arpresolve_full()
495 		/* Prefer ANY existing lle over newly-created one */  in arpresolve_full()
509 	if ((la->la_flags & LLE_VALID) &&  in arpresolve_full()
510 	    ((la->la_flags & LLE_STATIC) || la->la_expire > time_uptime)) {  in arpresolve_full()
512 			lladdr = la->ll_addr;  in arpresolve_full()
513 			ll_len = ifp->if_addrlen;  in arpresolve_full()
515 			lladdr = la->r_linkdata;  in arpresolve_full()
516 			ll_len = la->r_hdrlen;  in arpresolve_full()
523 			*pflags = la->la_flags & (LLE_VALID|LLE_IFADDR);  in arpresolve_full()
532 	renew = (la->la_asked == 0 || la->la_expire != time_uptime);  in arpresolve_full()
551 	if (la->la_asked < V_arp_maxtries)  in arpresolve_full()
560 		la->la_expire = time_uptime;  in arpresolve_full()
561 		canceled = callout_reset(&la->lle_timer, hz * V_arpt_down,  in arpresolve_full()
565 		la->la_asked++;  in arpresolve_full()
567 		e = arprequest_internal(ifp, NULL, &SIN(dst)->sin_addr, NULL);  in arpresolve_full()
612 		if (m->m_flags & M_BCAST) {  in arpresolve()
615 			    ifp->if_broadcastaddr, ifp->if_addrlen);  in arpresolve()
618 		if (m->m_flags & M_MCAST) {  in arpresolve()
620 			ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten);  in arpresolve()
626 	if (la != NULL && (la->r_flags & RLLE_VALID) != 0) {  in arpresolve()
628 		bcopy(la->r_linkdata, desten, la->r_hdrlen);  in arpresolve()
630 			*pflags = LLE_VALID | (la->r_flags & RLLE_IFADDR);  in arpresolve()
649  * then the protocol-specific routine is called.
659 	ifp = m->m_pkthdr.rcvif;  in arpintr()
661 	if (m->m_len < sizeof(struct arphdr) &&  in arpintr()
670 	if (m->m_len <  arphdr_len(ar)) {  in arpintr()
682 	switch (ntohs(ar->ar_hrd)) {  in arpintr()
701 		 * Currently we are capable of handling 20-byte  in arpintr()
702 		 * addresses ( sizeof(lle->ll_addr) )  in arpintr()
704 		if (ar->ar_hln >= 20)  in arpintr()
710 		    "%s\n", ntohs(ar->ar_hrd), if_name(ifp));  in arpintr()
715 	if (hlen != 0 && hlen != ar->ar_hln) {  in arpintr()
718 		    layer, ar->ar_hln, if_name(ifp));  in arpintr()
724 	switch (ntohs(ar->ar_pro)) {  in arpintr()
770 	struct ifnet *ifp = m->m_pkthdr.rcvif;  in in_arpinput()
796 	if (ifp->if_bridge)  in in_arpinput()
798 	if (ifp->if_type == IFT_BRIDGE)  in in_arpinput()
811 	if (ah->ar_pln != sizeof(struct in_addr)) {  in in_arpinput()
819 		    ifp->if_addrlen, (u_char *)ar_sha(ah), ":");  in in_arpinput()
823 	op = ntohs(ah->ar_op);  in in_arpinput()
836 		if (((bridged && bridge_same_p(ia->ia_ifp->if_bridge, ifp->if_bridge)) ||  in in_arpinput()
837 		    ia->ia_ifp == ifp) &&  in in_arpinput()
838 		    itaddr.s_addr == ia->ia_addr.sin_addr.s_addr &&  in in_arpinput()
839 		    (ia->ia_ifa.ifa_carp == NULL ||  in in_arpinput()
840 		    (*carp_iamatch_p)(&ia->ia_ifa, &enaddr))) {  in in_arpinput()
841 			ifa_ref(&ia->ia_ifa);  in in_arpinput()
846 		if (((bridged && bridge_same_p(ia->ia_ifp->if_bridge, ifp->if_bridge)) ||  in in_arpinput()
847 		    ia->ia_ifp == ifp) &&  in in_arpinput()
848 		    isaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {  in in_arpinput()
849 			ifa_ref(&ia->ia_ifa);  in in_arpinput()
854   (bridge_get_softc_p(ia->ia_ifp) == ifp->if_softc &&			\  in in_arpinput()
855   !bcmp(IF_LLADDR(ia->ia_ifp), IF_LLADDR(ifp), ifp->if_addrlen) &&	\  in in_arpinput()
856   addr == ia->ia_addr.sin_addr.s_addr)  in in_arpinput()
866 				ifa_ref(&ia->ia_ifa);  in in_arpinput()
867 				ifp = ia->ia_ifp;  in in_arpinput()
878 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)  in in_arpinput()
879 		if (ifa->ifa_addr->sa_family == AF_INET &&  in in_arpinput()
880 		    (ifa->ifa_carp == NULL ||  in in_arpinput()
892 	ifa_ref(&ia->ia_ifa);  in in_arpinput()
896 	carped = (ia->ia_ifa.ifa_carp != NULL);  in in_arpinput()
897 	myaddr = ia->ia_addr.sin_addr;  in in_arpinput()
898 	ifa_free(&ia->ia_ifa);  in in_arpinput()
899 	if (!bcmp(ar_sha(ah), enaddr, ifp->if_addrlen))  in in_arpinput()
901 	if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) {  in in_arpinput()
907 	if (ifp->if_addrlen != ah->ar_hln) {  in in_arpinput()
909 		    "i/f %d (ignored)\n", ifp->if_addrlen,  in in_arpinput()
910 		    (u_char *) ar_sha(ah), ":", ah->ar_hln,  in in_arpinput()
911 		    ifp->if_addrlen);  in in_arpinput()
924 		   ifp->if_addrlen, (u_char *)ar_sha(ah), ":",  in in_arpinput()
925 		   inet_ntoa_r(isaddr, addrbuf), ifp->if_xname);  in in_arpinput()
930 	if (ifp->if_flags & IFF_STATICARP)  in in_arpinput()
956 			 * to non-directly connected subnet. However, we  in in_arpinput()
973 		 * 1a) 'arp -s' static entry or  in in_arpinput()
976 		 * 2) it was the result of sending first packet to-host  in in_arpinput()
983 		 * existing lle over newly-create one.  in in_arpinput()
993 			/* Free newly-create entry and handle packet */  in in_arpinput()
1009 		(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);  in in_arpinput()
1010 		(void)memcpy(ar_sha(ah), enaddr, ah->ar_hln);  in in_arpinput()
1021 		if ((lle != NULL) && (lle->la_flags & LLE_PUB)) {  in in_arpinput()
1022 			(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);  in in_arpinput()
1023 			(void)memcpy(ar_sha(ah), lle->ll_addr, ah->ar_hln);  in in_arpinput()
1033 			nh = fib4_lookup(ifp->if_fib, itaddr, 0, 0, 0);  in in_arpinput()
1042 			if (nh->nh_ifp == ifp)  in in_arpinput()
1045 			(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);  in in_arpinput()
1046 			(void)memcpy(ar_sha(ah), enaddr, ah->ar_hln);  in in_arpinput()
1055 			nh = fib4_lookup(ifp->if_fib, isaddr, 0, 0, 0);  in in_arpinput()
1058 			if (nh->nh_ifp != ifp) {  in in_arpinput()
1062 				    ifp->if_xname);  in in_arpinput()
1075 		/* RFC 3927 link-local IPv4; always reply by broadcast. */  in in_arpinput()
1077 		printf("arp: sending reply for link-local addr %s\n",  in in_arpinput()
1080 		m->m_flags |= M_BCAST;  in in_arpinput()
1081 		m->m_flags &= ~M_MCAST;  in in_arpinput()
1084 		m->m_flags &= ~(M_BCAST|M_MCAST);  in in_arpinput()
1086 	(void)memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln);  in in_arpinput()
1087 	(void)memcpy(ar_spa(ah), &itaddr, ah->ar_pln);  in in_arpinput()
1088 	ah->ar_op = htons(ARPOP_REPLY);  in in_arpinput()
1089 	ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */  in in_arpinput()
1090 	m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln);  in in_arpinput()
1091 	m->m_pkthdr.len = m->m_len;  in in_arpinput()
1092 	m->m_pkthdr.rcvif = NULL;  in in_arpinput()
1117 	(*ifp->if_output)(ifp, m, &sa, &ro);  in in_arpinput()
1133 	chain = la->la_hold;  in arp_grab_holdchain()
1134 	la->la_hold = NULL;  in arp_grab_holdchain()
1135 	la->la_numheld = 0;  in arp_grab_holdchain()
1149 		.ro_prepend = la->r_linkdata,  in arp_flush_holdchain()
1150 		.ro_plen = la->r_hdrlen,  in arp_flush_holdchain()
1156 		m_hold_next = m_hold->m_nextpkt;  in arp_flush_holdchain()
1157 		m_hold->m_nextpkt = NULL;  in arp_flush_holdchain()
1160 		(*ifp->if_output)(ifp, m_hold, (struct sockaddr *)&sin, &ro);  in arp_flush_holdchain()
1180 	if (!bridged && la->lle_tbl->llt_ifp != ifp) {  in arp_check_update_lle()
1185 			    la->lle_tbl->llt_ifp->if_xname,  in arp_check_update_lle()
1186 			    ifp->if_addrlen, (u_char *)ar_sha(ah), ":",  in arp_check_update_lle()
1187 			    ifp->if_xname);  in arp_check_update_lle()
1191 	if ((la->la_flags & LLE_VALID) &&  in arp_check_update_lle()
1192 	    bcmp(ar_sha(ah), la->ll_addr, ifp->if_addrlen)) {  in arp_check_update_lle()
1193 		if (la->la_flags & LLE_STATIC) {  in arp_check_update_lle()
1199 				    ifp->if_addrlen,  in arp_check_update_lle()
1202 				    ifp->if_xname);  in arp_check_update_lle()
1209 			    ifp->if_addrlen,  in arp_check_update_lle()
1210 			    (u_char *)la->ll_addr, ":",  in arp_check_update_lle()
1211 			    ifp->if_addrlen, (u_char *)ar_sha(ah), ":",  in arp_check_update_lle()
1212 			    ifp->if_xname);  in arp_check_update_lle()
1225 	if (memcmp(la->r_linkdata, linkhdr, linkhdrsize) != 0 ||  in arp_check_update_lle()
1226 	    (la->la_flags & LLE_VALID) == 0) {  in arp_check_update_lle()
1247 	if (la->la_hold != NULL) {  in arp_check_update_lle()
1264 	la->ln_state = ARP_LLINFO_REACHABLE;  in arp_mark_lle_reachable()
1267 	if ((ifp->if_flags & IFF_STICKYARP) != 0)  in arp_mark_lle_reachable()
1268 		la->la_flags |= LLE_STATIC;  in arp_mark_lle_reachable()
1270 	if (!(la->la_flags & LLE_STATIC)) {  in arp_mark_lle_reachable()
1272 		la->la_expire = time_uptime + V_arpt_keep;  in arp_mark_lle_reachable()
1273 		wtime = V_arpt_keep - V_arp_maxtries * V_arpt_rexmit;  in arp_mark_lle_reachable()
1276 		canceled = callout_reset(&la->lle_timer,  in arp_mark_lle_reachable()
1277 		    hz * wtime, arptimer, la);  in arp_mark_lle_reachable()
1281 	la->la_asked = 0;  in arp_mark_lle_reachable()
1282 	la->la_preempt = V_arp_maxtries;  in arp_mark_lle_reachable()
1286  * Add permanent link-layer record for given interface address.
1337 	if (!error && req->newptr) {  in sysctl_garp_rexmit()
1360 	if (callout_pending(&ia->ia_garp_timer) ||  in garp_rexmit()
1361 	    !callout_active(&ia->ia_garp_timer)) {  in garp_rexmit()
1362 		IF_ADDR_WUNLOCK(ia->ia_ifa.ifa_ifp);  in garp_rexmit()
1363 		ifa_free(&ia->ia_ifa);  in garp_rexmit()
1368 	CURVNET_SET(ia->ia_ifa.ifa_ifp->if_vnet);  in garp_rexmit()
1373 	IF_ADDR_WUNLOCK(ia->ia_ifa.ifa_ifp);  in garp_rexmit()
1375 	arprequest(ia->ia_ifa.ifa_ifp, &IA_SIN(ia)->sin_addr,  in garp_rexmit()
1376 	    &IA_SIN(ia)->sin_addr, IF_LLADDR(ia->ia_ifa.ifa_ifp));  in garp_rexmit()
1383 	++ia->ia_garp_count;  in garp_rexmit()
1384 	if (ia->ia_garp_count >= V_garp_rexmit_count) {  in garp_rexmit()
1385 		ifa_free(&ia->ia_ifa);  in garp_rexmit()
1388 		IF_ADDR_WLOCK(ia->ia_ifa.ifa_ifp);  in garp_rexmit()
1389 		rescheduled = callout_reset(&ia->ia_garp_timer,  in garp_rexmit()
1390 		    (1 << ia->ia_garp_count) * hz,  in garp_rexmit()
1392 		IF_ADDR_WUNLOCK(ia->ia_ifa.ifa_ifp);  in garp_rexmit()
1394 			ifa_free(&ia->ia_ifa);  in garp_rexmit()
1425 	IF_ADDR_WLOCK(ia->ia_ifa.ifa_ifp);  in garp_timer_start()
1426 	ia->ia_garp_count = 0;  in garp_timer_start()
1427 	if (callout_reset(&ia->ia_garp_timer, (1 << ia->ia_garp_count) * hz,  in garp_timer_start()
1431 	IF_ADDR_WUNLOCK(ia->ia_ifa.ifa_ifp);  in garp_timer_start()
1441 	if (ifa->ifa_carp != NULL)  in arp_ifinit()
1444 	dst = ifa->ifa_addr;  in arp_ifinit()
1447 	if (ntohl(dst_in->sin_addr.s_addr) == INADDR_ANY)  in arp_ifinit()
1450 	arp_announce_ifaddr(ifp, dst_in->sin_addr, IF_LLADDR(ifp));  in arp_ifinit()
1476 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {  in arp_handle_ifllchange()
1477 		if (ifa->ifa_addr->sa_family == AF_INET)  in arp_handle_ifllchange()
1490 	if (ifp->if_afdata[AF_INET] == NULL)  in arp_iflladdr()
1495 	if ((ifp->if_flags & IFF_UP) != 0)  in arp_iflladdr()