 @@ -1,1320 +1,1324 @@
-/*	$NetBSD: if_arp.c,v 1.292 2020/01/23 17:27:35 roy Exp $	*/
+/*	$NetBSD: if_arp.c,v 1.293 2020/03/09 17:57:19 roy Exp $	*/
 /*
  * Copyright (c) 1998, 2000, 2008 The NetBSD Foundation, Inc.
  * All rights reserved.
+ *
  * This code is derived from software contributed to The NetBSD Foundation
  * by Public Access Networks Corporation ("Panix").  It was developed under
  * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
+ *
  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
 /*
  * Copyright (c) 1982, 1986, 1988, 1993
  *	The Regents of the University of California.  All rights reserved.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
+ *
  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
+ *
  *	@(#)if_ether.c	8.2 (Berkeley) 9/26/94
  */
 /*
  * Ethernet address resolution protocol.
  * TODO:
  *	add "inuse/lock" bit (or ref. count) along with valid bit
  */
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.292 2020/01/23 17:27:35 roy Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.293 2020/03/09 17:57:19 roy Exp $");
 #ifdef _KERNEL_OPT
 #include "opt_ddb.h"
 #include "opt_inet.h"
 #include "opt_net_mpsafe.h"
 #endif
 #ifdef INET
 #include "arp.h"
 #include "bridge.h"
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/callout.h>
 #include <sys/kmem.h>
 #include <sys/mbuf.h>
 #include <sys/socket.h>
 #include <sys/time.h>
 #include <sys/timetc.h>
 #include <sys/kernel.h>
 #include <sys/errno.h>
 #include <sys/ioctl.h>
 #include <sys/syslog.h>
 #include <sys/proc.h>
 #include <sys/protosw.h>
 #include <sys/domain.h>
 #include <sys/sysctl.h>
 #include <sys/socketvar.h>
 #include <sys/percpu.h>
 #include <sys/cprng.h>
 #include <sys/kmem.h>
 #include <net/ethertypes.h>
 #include <net/if.h>
 #include <net/if_dl.h>
 #include <net/if_types.h>
 #include <net/if_ether.h>
 #include <net/if_llatbl.h>
 #include <net/route.h>
 #include <net/net_stats.h>
 #include <netinet/in.h>
 #include <netinet/in_systm.h>
 #include <netinet/in_var.h>
 #include <netinet/ip.h>
 #include <netinet/if_inarp.h>
 #include "arcnet.h"
 #if NARCNET > 0
 #include <net/if_arc.h>
 #endif
 #include "carp.h"
 #if NCARP > 0
 #include <netinet/ip_carp.h>
 #endif
 /*
  * ARP trailer negotiation.  Trailer protocol is not IP specific,
  * but ARP request/response use IP addresses.
  */
 #define ETHERTYPE_IPTRAILERS ETHERTYPE_TRAIL
 /* timer values */
 static int arpt_keep = (20*60);	/* once resolved, good for 20 more minutes */
 static int arpt_down = 20;		/* once declared down, don't send for 20 secs */
 static int arp_maxhold = 1;	/* number of packets to hold per ARP entry */
 #define	rt_expire rt_rmx.rmx_expire
 #define	rt_pksent rt_rmx.rmx_pksent
 int ip_dad_count = PROBE_NUM;
 #ifdef ARP_DEBUG
 int arp_debug = 1;
 #else
 int arp_debug = 0;
 #endif
 static void arp_init(void);
 static void arp_dad_init(void);
 static void arprequest(struct ifnet *,
     const struct in_addr *, const struct in_addr *,
     const uint8_t *);
 static void arpannounce1(struct ifaddr *);
 static struct sockaddr *arp_setgate(struct rtentry *, struct sockaddr *,
     const struct sockaddr *);
 static void arptimer(void *);
 static void arp_settimer(struct llentry *, int);
 static struct llentry *arplookup(struct ifnet *,
     const struct in_addr *, const struct sockaddr *, int);
 static struct llentry *arpcreate(struct ifnet *,
     const struct in_addr *, const struct sockaddr *, int);
 static void in_arpinput(struct mbuf *);
 static void in_revarpinput(struct mbuf *);
 static void revarprequest(struct ifnet *);
 static void arp_drainstub(void);
 struct dadq;
 static void arp_dad_timer(struct dadq *);
 static void arp_dad_start(struct ifaddr *);
 static void arp_dad_stop(struct ifaddr *);
 static void arp_dad_duplicated(struct ifaddr *, const struct sockaddr_dl *);
 static void arp_init_llentry(struct ifnet *, struct llentry *);
 struct ifqueue arpintrq = {
 	.ifq_head = NULL,
 	.ifq_tail = NULL,
 	.ifq_len = 0,
 	.ifq_maxlen = 50,
 	.ifq_drops = 0,
 };
 static int arp_maxtries = 5;
 static int useloopback = 1;	/* use loopback interface for local traffic */
 static percpu_t *arpstat_percpu;
 #define	ARP_STAT_GETREF()	_NET_STAT_GETREF(arpstat_percpu)
 #define	ARP_STAT_PUTREF()	_NET_STAT_PUTREF(arpstat_percpu)
 #define	ARP_STATINC(x)		_NET_STATINC(arpstat_percpu, x)
 #define	ARP_STATADD(x, v)	_NET_STATADD(arpstat_percpu, x, v)
 /* revarp state */
 static struct in_addr myip, srv_ip;
 static int myip_initialized = 0;
 static int revarp_in_progress = 0;
 static struct ifnet *myip_ifp = NULL;
 static int arp_drainwanted;
 static int log_movements = 0;
 static int log_permanent_modify = 1;
 static int log_wrong_iface = 1;
 DOMAIN_DEFINE(arpdomain);	/* forward declare and add to link set */
 static void
 arp_fasttimo(void)
+{
 	if (arp_drainwanted) {
 		arp_drain();
 		arp_drainwanted = 0;
+	}
+}
 static const struct protosw arpsw[] = {
+	{
 		.pr_type = 0,
 		.pr_domain = &arpdomain,
 		.pr_protocol = 0,
 		.pr_flags = 0,
 		.pr_input = 0,
 		.pr_ctlinput = 0,
 		.pr_ctloutput = 0,
 		.pr_usrreqs = 0,
 		.pr_init = arp_init,
 		.pr_fasttimo = arp_fasttimo,
 		.pr_slowtimo = 0,
 		.pr_drain = arp_drainstub,
+	}
 };
 struct domain arpdomain = {
 	.dom_family = PF_ARP,
 	.dom_name = "arp",
 	.dom_protosw = arpsw,
 	.dom_protoswNPROTOSW = &arpsw[__arraycount(arpsw)],
 #ifdef MBUFTRACE
 	.dom_mowner = MOWNER_INIT("internet", "arp"),
 #endif
 };
 static void sysctl_net_inet_arp_setup(struct sysctllog **);
 void
 arp_init(void)
+{
 	sysctl_net_inet_arp_setup(NULL);
 	arpstat_percpu = percpu_alloc(sizeof(uint64_t) * ARP_NSTATS);
 	IFQ_LOCK_INIT(&arpintrq);
 #ifdef MBUFTRACE
 	MOWNER_ATTACH(&arpdomain.dom_mowner);
 #endif
 	arp_dad_init();
+}
 static void
 arp_drainstub(void)
+{
 	arp_drainwanted = 1;
+}
 /*
  * ARP protocol drain routine.  Called when memory is in short supply.
  * Called at splvm();  don't acquire softnet_lock as can be called from
  * hardware interrupt handlers.
  */
 void
 arp_drain(void)
+{
 	lltable_drain(AF_INET);
+}
 static void
 arptimer(void *arg)
+{
 	struct llentry *lle = arg;
 	struct ifnet *ifp;
 	KASSERT((lle->la_flags & LLE_STATIC) == 0);
 	LLE_WLOCK(lle);
 	/*
 	 * This shortcut is required to avoid trying to touch ifp that may be
 	 * being destroyed.
 	 */
 	if ((lle->la_flags & LLE_LINKED) == 0) {
 		LLE_FREE_LOCKED(lle);
 		return;
+	}
 	ifp = lle->lle_tbl->llt_ifp;
 	/* XXX: LOR avoidance. We still have ref on lle. */
 	LLE_WUNLOCK(lle);
 	IF_AFDATA_LOCK(ifp);
 	LLE_WLOCK(lle);
 	/* Guard against race with other llentry_free(). */
 	if (lle->la_flags & LLE_LINKED) {
 		int rt_cmd;
 		struct in_addr *in;
 		struct sockaddr_in sin;
 		const char *lladdr;
 		size_t pkts_dropped;
 		in = &lle->r_l3addr.addr4;
 		sockaddr_in_init(&sin, in, 0);
 		if (lle->la_flags & LLE_VALID) {
-			struct in_addr *in;
+			rt_cmd = RTM_DELETE;
 			struct sockaddr_in sin;
 			const char *lladdr;
 			in = &lle->r_l3addr.addr4;
 			sockaddr_in_init(&sin, in, 0);
 			lladdr = (const char *)&lle->ll_addr;
-			rt_clonedmsg(RTM_DELETE, sintosa(&sin), lladdr, ifp);
+		} else {
 			rt_cmd = RTM_MISS;
 			lladdr = NULL;
+		}
 		rt_clonedmsg(rt_cmd, sintosa(&sin), lladdr, ifp);
 		LLE_REMREF(lle);
 		pkts_dropped = llentry_free(lle);
 		ARP_STATADD(ARP_STAT_DFRDROPPED, pkts_dropped);
 		ARP_STATADD(ARP_STAT_DFRTOTAL, pkts_dropped);
 	} else {
 		LLE_FREE_LOCKED(lle);
+	}
 	IF_AFDATA_UNLOCK(ifp);
+}
 static void
 arp_settimer(struct llentry *la, int sec)
+{
 	LLE_WLOCK_ASSERT(la);
 	KASSERT((la->la_flags & LLE_STATIC) == 0);
 	/*
 	 * We have to take care of a reference leak which occurs if
 	 * callout_reset overwrites a pending callout schedule.  Unfortunately
 	 * we don't have a mean to know the overwrite, so we need to know it
 	 * using callout_stop.  We need to call callout_pending first to exclude
 	 * the case that the callout has never been scheduled.
 	 */
 	if (callout_pending(&la->la_timer)) {
 		bool expired = callout_stop(&la->la_timer);
 		if (!expired)
 			/* A pending callout schedule is canceled. */
 			LLE_REMREF(la);
+	}
 	LLE_ADDREF(la);
 	callout_reset(&la->la_timer, hz * sec, arptimer, la);
+}
 /*
  * We set the gateway for RTF_CLONING routes to a "prototype"
  * link-layer sockaddr whose interface type (if_type) and interface
  * index (if_index) fields are prepared.
  */
 static struct sockaddr *
 arp_setgate(struct rtentry *rt, struct sockaddr *gate,
     const struct sockaddr *netmask)
+{
 	const struct ifnet *ifp = rt->rt_ifp;
 	uint8_t namelen = strlen(ifp->if_xname);
 	uint8_t addrlen = ifp->if_addrlen;
 	/*
 	 * XXX: If this is a manually added route to interface
 	 * such as older version of routed or gated might provide,
 	 * restore cloning bit.
 	 */
 	if ((rt->rt_flags & RTF_HOST) == 0 && netmask != NULL &&
 	    satocsin(netmask)->sin_addr.s_addr != 0xffffffff)
 		rt->rt_flags |= RTF_CONNECTED;
 	if ((rt->rt_flags & (RTF_CONNECTED | RTF_LOCAL))) {
 		union {
 			struct sockaddr sa;
 			struct sockaddr_storage ss;
 			struct sockaddr_dl sdl;
 		} u;
 		/*
 		 * Case 1: This route should come from a route to iface.
 		 */
 		sockaddr_dl_init(&u.sdl, sizeof(u.ss),
 		    ifp->if_index, ifp->if_type, NULL, namelen, NULL, addrlen);
 		rt_setgate(rt, &u.sa);
 		gate = rt->rt_gateway;
+	}
 	return gate;
+}
 static void
 arp_init_llentry(struct ifnet *ifp, struct llentry *lle)
+{
 	switch (ifp->if_type) {
 	default:
 		/* Nothing. */
 		break;
+	}
+}
 /*
  * Parallel to llc_rtrequest.
  */
 void
 arp_rtrequest(int req, struct rtentry *rt, const struct rt_addrinfo *info)
+{
 	struct sockaddr *gate = rt->rt_gateway;
 	struct in_ifaddr *ia;
 	struct ifaddr *ifa;
 	struct ifnet *ifp = rt->rt_ifp;
 	int bound;
 	int s;
 	if (req == RTM_LLINFO_UPD) {
 		if ((ifa = info->rti_ifa) != NULL)
 			arpannounce1(ifa);
 		return;
+	}
 	if ((rt->rt_flags & RTF_GATEWAY) != 0) {
 		if (req != RTM_ADD)
 			return;
 		/*
 		 * linklayers with particular link MTU limitation.
 		 */
 		switch(ifp->if_type) {
 #if NARCNET > 0
 		case IFT_ARCNET:
+		    {
 			int arcipifmtu;
 			if (ifp->if_flags & IFF_LINK0)
 				arcipifmtu = arc_ipmtu;
 			else
 				arcipifmtu = ARCMTU;
 			if (ifp->if_mtu > arcipifmtu)
 				rt->rt_rmx.rmx_mtu = arcipifmtu;
 			break;
+		    }
 #endif
+		}
 		return;
+	}
 	switch (req) {
 	case RTM_SETGATE:
 		gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]);
 		break;
 	case RTM_ADD:
 		gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]);
 		if (gate == NULL) {
 			log(LOG_ERR, "%s: arp_setgate failed\n", __func__);
 			break;
+		}
 		if ((rt->rt_flags & RTF_CONNECTED) ||
 		    (rt->rt_flags & RTF_LOCAL)) {
 			/*
 			 * Give this route an expiration time, even though
 			 * it's a "permanent" route, so that routes cloned
 			 * from it do not need their expiration time set.
 			 */
 			KASSERT(time_uptime != 0);
 			rt->rt_expire = time_uptime;
 			/*
 			 * linklayers with particular link MTU limitation.
 			 */
 			switch (ifp->if_type) {
 #if NARCNET > 0
 			case IFT_ARCNET:
+			    {
 				int arcipifmtu;
 				if (ifp->if_flags & IFF_LINK0)
 					arcipifmtu = arc_ipmtu;
 				else
 					arcipifmtu = ARCMTU;
 				if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 &&
 				    (rt->rt_rmx.rmx_mtu > arcipifmtu ||
 				     (rt->rt_rmx.rmx_mtu == 0 &&
 				      ifp->if_mtu > arcipifmtu)))
 					rt->rt_rmx.rmx_mtu = arcipifmtu;
 				break;
+			    }
 #endif
+			}
 			if (rt->rt_flags & RTF_CONNECTED)
 				break;
+		}
 		bound = curlwp_bind();
 		/* Announce a new entry if requested. */
 		if (rt->rt_flags & RTF_ANNOUNCE) {
 			struct psref psref;
 			ia = in_get_ia_on_iface_psref(
 			    satocsin(rt_getkey(rt))->sin_addr, ifp, &psref);
 			if (ia != NULL) {
 				arpannounce(ifp, &ia->ia_ifa,
 				    CLLADDR(satocsdl(gate)));
 				ia4_release(ia, &psref);
+			}
+		}
 		if (gate->sa_family != AF_LINK ||
 		    gate->sa_len < sockaddr_dl_measure(0, ifp->if_addrlen)) {
 			log(LOG_DEBUG, "%s: bad gateway value\n", __func__);
 			goto out;
+		}
 		satosdl(gate)->sdl_type = ifp->if_type;
 		satosdl(gate)->sdl_index = ifp->if_index;
 		/*
 		 * If the route is for a broadcast address mark it as such.
 		 * This way we can avoid an expensive call to in_broadcast()
 		 * in ip_output() most of the time (because the route passed
 		 * to ip_output() is almost always a host route).
 		 */
 		if (rt->rt_flags & RTF_HOST &&
 		    !(rt->rt_flags & RTF_BROADCAST) &&
 		    in_broadcast(satocsin(rt_getkey(rt))->sin_addr, rt->rt_ifp))
 			rt->rt_flags |= RTF_BROADCAST;
 		/* There is little point in resolving the broadcast address */
 		if (rt->rt_flags & RTF_BROADCAST)
 			goto out;
 		/*
 		 * When called from rt_ifa_addlocal, we cannot depend on that
 		 * the address (rt_getkey(rt)) exits in the address list of the
 		 * interface. So check RTF_LOCAL instead.
 		 */
 		if (rt->rt_flags & RTF_LOCAL) {
 			rt->rt_expire = 0;
 			if (useloopback) {
 				rt->rt_ifp = lo0ifp;
 				rt->rt_rmx.rmx_mtu = 0;
+			}
 			goto out;
+		}
 		s = pserialize_read_enter();
 		ia = in_get_ia_on_iface(satocsin(rt_getkey(rt))->sin_addr, ifp);
 		if (ia == NULL) {
 			pserialize_read_exit(s);
 			goto out;
+		}
 		rt->rt_expire = 0;
 		if (useloopback) {
 			rt->rt_ifp = lo0ifp;
 			rt->rt_rmx.rmx_mtu = 0;
+		}
 		rt->rt_flags |= RTF_LOCAL;
 		if (ISSET(info->rti_flags, RTF_DONTCHANGEIFA)) {
 			pserialize_read_exit(s);
 			goto out;
+		}
 		/*
 		 * make sure to set rt->rt_ifa to the interface
 		 * address we are using, otherwise we will have trouble
 		 * with source address selection.
 		 */
 		ifa = &ia->ia_ifa;
 		if (ifa != rt->rt_ifa)
 			/* Assume it doesn't sleep */
 			rt_replace_ifa(rt, ifa);
 		pserialize_read_exit(s);
 	out:
 		curlwp_bindx(bound);
 		break;
+	}
+}
 /*
  * Broadcast an ARP request. Caller specifies:
  *	- arp header source ip address
  *	- arp header target ip address
  *	- arp header source ethernet address
  */
 static void
 arprequest(struct ifnet *ifp,
     const struct in_addr *sip, const struct in_addr *tip,
     const uint8_t *enaddr)
+{
 	struct mbuf *m;
 	struct arphdr *ah;
 	struct sockaddr sa;
 	uint64_t *arps;
 	KASSERT(sip != NULL);
 	KASSERT(tip != NULL);
 	KASSERT(enaddr != NULL);
 	if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
 		return;
 	MCLAIM(m, &arpdomain.dom_mowner);
 	switch (ifp->if_type) {
 	case IFT_IEEE1394:
 		m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) +
 		    ifp->if_addrlen;
 		break;
 	default:
 		m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) +
 * ifp->if_addrlen;
 		break;
+	}
 	m->m_pkthdr.len = m->m_len;
 	m_align(m, m->m_len);
 	ah = mtod(m, struct arphdr *);
 	memset(ah, 0, m->m_len);
 	switch (ifp->if_type) {
 	case IFT_IEEE1394:	/* RFC2734 */
 		/* fill it now for ar_tpa computation */
 		ah->ar_hrd = htons(ARPHRD_IEEE1394);
 		break;
 	default:
 		/* ifp->if_output will fill ar_hrd */
 		break;
+	}
 	ah->ar_pro = htons(ETHERTYPE_IP);
 	ah->ar_hln = ifp->if_addrlen;		/* hardware address length */
 	ah->ar_pln = sizeof(struct in_addr);	/* protocol address length */
 	ah->ar_op = htons(ARPOP_REQUEST);
 	memcpy(ar_sha(ah), enaddr, ah->ar_hln);
 	memcpy(ar_spa(ah), sip, ah->ar_pln);
 	memcpy(ar_tpa(ah), tip, ah->ar_pln);
 	sa.sa_family = AF_ARP;
 	sa.sa_len = 2;
 	m->m_flags |= M_BCAST;
 	arps = ARP_STAT_GETREF();
 	arps[ARP_STAT_SNDTOTAL]++;
 	arps[ARP_STAT_SENDREQUEST]++;
 	ARP_STAT_PUTREF();
 	if_output_lock(ifp, ifp, m, &sa, NULL);
+}
 void
 arpannounce(struct ifnet *ifp, struct ifaddr *ifa, const uint8_t *enaddr)
+{
 	struct in_ifaddr *ia = ifatoia(ifa);
 	struct in_addr *ip = &IA_SIN(ifa)->sin_addr;
 	if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) {
 		ARPLOG(LOG_DEBUG, "%s not ready\n", ARPLOGADDR(ip));
 		return;
+	}
 	arprequest(ifp, ip, ip, enaddr);
+}
 static void
 arpannounce1(struct ifaddr *ifa)
+{
 	arpannounce(ifa->ifa_ifp, ifa, CLLADDR(ifa->ifa_ifp->if_sadl));
+}
 /*
  * Resolve an IP address into an ethernet address.  If success, desten is
  * filled in. If there is no entry in arptab, set one up and broadcast a
  * request for the IP address. Hold onto this mbuf and resend it once the
  * address is finally resolved.
+ *
  * A return value of 0 indicates that desten has been filled in and the packet
  * should be sent normally; a return value of EWOULDBLOCK indicates that the
  * packet has been held pending resolution. Any other value indicates an
  * error.
  */
 int
 arpresolve(struct ifnet *ifp, const struct rtentry *rt, struct mbuf *m,
     const struct sockaddr *dst, void *desten, size_t destlen)
+{
 	struct llentry *la;
 	const char *create_lookup;
 	bool renew;
 	int error;
 	struct ifnet *origifp = ifp;
 #if NCARP > 0
 	if (rt != NULL && rt->rt_ifp->if_type == IFT_CARP)
 		ifp = rt->rt_ifp;
 #endif
 	KASSERT(m != NULL);
 	la = arplookup(ifp, NULL, dst, 0);
 	if (la == NULL)
 		goto notfound;
 	if ((la->la_flags & LLE_VALID) &&
 	    ((la->la_flags & LLE_STATIC) || la->la_expire > time_uptime)) {
 		KASSERT(destlen >= ifp->if_addrlen);
 		memcpy(desten, &la->ll_addr, ifp->if_addrlen);
 		LLE_RUNLOCK(la);
 		return 0;
+	}
 notfound:
 	if (ifp->if_flags & IFF_NOARP) {
 		if (la != NULL)
 			LLE_RUNLOCK(la);
 		error = ENOTSUP;
 		goto bad;
+	}
 	if (la == NULL) {
 		struct rtentry *_rt;
 		create_lookup = "create";
 		_rt = rtalloc1(dst, 0);
 		IF_AFDATA_WLOCK(ifp);
 		la = lla_create(LLTABLE(ifp), LLE_EXCLUSIVE, dst, _rt);
 		IF_AFDATA_WUNLOCK(ifp);
 		if (_rt != NULL)
 			rt_unref(_rt);
 		if (la == NULL)
 			ARP_STATINC(ARP_STAT_ALLOCFAIL);
 		else
 			arp_init_llentry(ifp, la);
 	} else if (LLE_TRY_UPGRADE(la) == 0) {
 		create_lookup = "lookup";
 		LLE_RUNLOCK(la);
 		IF_AFDATA_RLOCK(ifp);
 		la = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst);
 		IF_AFDATA_RUNLOCK(ifp);
+	}
 	error = EINVAL;
 	if (la == NULL) {
 		log(LOG_DEBUG,
 		    "%s: failed to %s llentry for %s on %s\n",
 		    __func__, create_lookup, inet_ntoa(satocsin(dst)->sin_addr),
 		    ifp->if_xname);
 		goto bad;
+	}
 	if ((la->la_flags & LLE_VALID) &&
 	    ((la->la_flags & LLE_STATIC) || la->la_expire > time_uptime))
+	{
 		KASSERT(destlen >= ifp->if_addrlen);
 		memcpy(desten, &la->ll_addr, ifp->if_addrlen);
 		renew = false;
 		/*
 		 * If entry has an expiry time and it is approaching,
 		 * see if we need to send an ARP request within this
 		 * arpt_down interval.
 		 */
 		if (!(la->la_flags & LLE_STATIC) &&
 		    time_uptime + la->la_preempt > la->la_expire)
+		{
 			renew = true;
 			la->la_preempt--;
+		}
 		LLE_WUNLOCK(la);
 		if (renew) {
 			const uint8_t *enaddr = CLLADDR(ifp->if_sadl);
 			arprequest(origifp,
 			    &satocsin(rt->rt_ifa->ifa_addr)->sin_addr,
 			    &satocsin(dst)->sin_addr, enaddr);
+		}
 		return 0;
+	}
 	if (la->la_flags & LLE_STATIC) {   /* should not happen! */
 		LLE_RUNLOCK(la);
 		log(LOG_DEBUG, "%s: ouch, empty static llinfo for %s\n",
 		    __func__, inet_ntoa(satocsin(dst)->sin_addr));
 		error = EINVAL;
 		goto bad;
+	}
 	renew = (la->la_asked == 0 || la->la_expire != time_uptime);
 	/*
 	 * There is an arptab entry, but no ethernet address
 	 * response yet.  Add the mbuf to the list, dropping
 	 * the oldest packet if we have exceeded the system
 	 * setting.
 	 */
 	LLE_WLOCK_ASSERT(la);
 	if (la->la_numheld >= arp_maxhold) {
 		if (la->la_hold != NULL) {
 			struct mbuf *next = la->la_hold->m_nextpkt;
 			m_freem(la->la_hold);
 			la->la_hold = next;
 			la->la_numheld--;
 			ARP_STATINC(ARP_STAT_DFRDROPPED);
 			ARP_STATINC(ARP_STAT_DFRTOTAL);
+		}
+	}
 	if (la->la_hold != NULL) {
 		struct mbuf *curr = la->la_hold;
 		while (curr->m_nextpkt != NULL)
 			curr = curr->m_nextpkt;
 		curr->m_nextpkt = m;
 	} else
 		la->la_hold = m;
 	la->la_numheld++;
 	if (!renew)
 		LLE_DOWNGRADE(la);
 	/*
 	 * Return EWOULDBLOCK if we have tried less than arp_maxtries. It
 	 * will be masked by ether_output(). Return EHOSTDOWN/EHOSTUNREACH
 	 * if we have already sent arp_maxtries ARP requests. Retransmit the
 	 * ARP request, but not faster than one request per second.
 	 */
 	if (la->la_asked < arp_maxtries)
 		error = EWOULDBLOCK;	/* First request. */
 	else
 		error = (rt != NULL && rt->rt_flags & RTF_GATEWAY) ?
 		    EHOSTUNREACH : EHOSTDOWN;
 	if (renew) {
 		const uint8_t *enaddr = CLLADDR(ifp->if_sadl);
 		struct sockaddr_in sin;
 		la->la_expire = time_uptime;
 		arp_settimer(la, arpt_down);
 		la->la_asked++;
 		sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0);
 		if (error != EWOULDBLOCK)
 			rt_clonedmsg(RTM_MISS, sintosa(&sin), NULL, ifp);
 		LLE_WUNLOCK(la);
 		if (rt != NULL) {
 			arprequest(origifp,
 			    &satocsin(rt->rt_ifa->ifa_addr)->sin_addr,
 			    &satocsin(dst)->sin_addr, enaddr);
 		} else {
 			struct rtentry *_rt;
 			/* XXX */
 			_rt = rtalloc1((struct sockaddr *)&sin, 0);
 			if (_rt == NULL)
 				goto bad;
 			arprequest(origifp,
 			    &satocsin(_rt->rt_ifa->ifa_addr)->sin_addr,
 			    &satocsin(dst)->sin_addr, enaddr);
 			rt_unref(_rt);
+		}
 		return error;
+	}
 	LLE_RUNLOCK(la);
 	return error;
 bad:
 	m_freem(m);
 	return error;
+}
 /*
  * Common length and type checks are done here,
  * then the protocol-specific routine is called.
  */
 void
 arpintr(void)
+{
 	struct mbuf *m;
 	struct arphdr *ar;
 	int s;
 	int arplen;
 	SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE();
 	for (;;) {
 		struct ifnet *rcvif;
 		IFQ_LOCK(&arpintrq);
 		IF_DEQUEUE(&arpintrq, m);
 		IFQ_UNLOCK(&arpintrq);
 		if (m == NULL)
 			goto out;
 		if ((m->m_flags & M_PKTHDR) == 0)
 			panic("arpintr");
 		MCLAIM(m, &arpdomain.dom_mowner);
 		ARP_STATINC(ARP_STAT_RCVTOTAL);
 		arplen = sizeof(struct arphdr);
 		if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL)
 			goto badlen;
 		ar = mtod(m, struct arphdr *);
 		rcvif = m_get_rcvif(m, &s);
 		if (__predict_false(rcvif == NULL)) {
 			ARP_STATINC(ARP_STAT_RCVNOINT);
 			goto free;
+		}
 		/*
 		 * We don't want non-IEEE1394 ARP packets on IEEE1394
 		 * interfaces, and vice versa. Our life depends on that.
 		 */
 		switch (rcvif->if_type) {
 		case IFT_IEEE1394:
 			if (ntohs(ar->ar_hrd) != ARPHRD_IEEE1394) {
 				m_put_rcvif(rcvif, &s);
 				ARP_STATINC(ARP_STAT_RCVBADPROTO);
 				goto free;
+			}
 			arplen = sizeof(struct arphdr) +
 			    ar->ar_hln + 2 * ar->ar_pln;
 			break;
 		default:
 			if (ntohs(ar->ar_hrd) == ARPHRD_IEEE1394) {
 				m_put_rcvif(rcvif, &s);
 				ARP_STATINC(ARP_STAT_RCVBADPROTO);
 				goto free;
+			}
 			arplen = sizeof(struct arphdr) +
 * ar->ar_hln + 2 * ar->ar_pln;
 			break;
+		}
 		m_put_rcvif(rcvif, &s);
 		if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL)
 			goto badlen;
 		ar = mtod(m, struct arphdr *);
 		switch (ntohs(ar->ar_pro)) {
 		case ETHERTYPE_IP:
 		case ETHERTYPE_IPTRAILERS:
 			in_arpinput(m);
 			continue;
 		default:
 			ARP_STATINC(ARP_STAT_RCVBADPROTO);
 			goto free;
+		}
 badlen:
 		ARP_STATINC(ARP_STAT_RCVBADLEN);
 free:
 		m_freem(m);
+	}
 out:
 	SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE();
 	return; /* XXX gcc */
+}
 /*
  * ARP for Internet protocols on 10 Mb/s Ethernet. Algorithm is that given in
  * RFC 826. In addition, a sanity check is performed on the sender protocol
  * address, to catch impersonators.
+ *
  * We no longer handle negotiations for use of trailer protocol: formerly, ARP
  * replied for protocol type ETHERTYPE_TRAIL sent along with IP replies if we
  * wanted trailers sent to us, and also sent them in response to IP replies.
  * This allowed either end to announce the desire to receive trailer packets.
+ *
  * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, but
  * formerly didn't normally send requests.
  */
 static void
 in_arpinput(struct mbuf *m)
+{
 	struct arphdr *ah;
 	struct ifnet *ifp, *rcvif = NULL;
 	struct llentry *la = NULL;
 	struct in_ifaddr *ia = NULL;
 #if NBRIDGE > 0
 	struct in_ifaddr *bridge_ia = NULL;
 #endif
 #if NCARP > 0
 	uint32_t count = 0, index = 0;
 #endif
 	struct sockaddr sa;
 	struct in_addr isaddr, itaddr, myaddr;
 	int op, rt_cmd;
 	void *tha;
 	uint64_t *arps;
 	struct psref psref, psref_ia;
 	int s;
 	char ipbuf[INET_ADDRSTRLEN];
 	bool find_source, do_dad;
 	if (__predict_false(m_makewritable(&m, 0, m->m_pkthdr.len, M_DONTWAIT)))
 		goto out;
 	ah = mtod(m, struct arphdr *);
 	op = ntohs(ah->ar_op);
 	if (ah->ar_pln != sizeof(struct in_addr))
 		goto out;
 	ifp = if_get_bylla(ar_sha(ah), ah->ar_hln, &psref);
 	if (ifp) {
 		/* it's from me, ignore it. */
 		if_put(ifp, &psref);
 		ARP_STATINC(ARP_STAT_RCVLOCALSHA);
 		goto out;
+	}
 	rcvif = ifp = m_get_rcvif_psref(m, &psref);
 	if (__predict_false(rcvif == NULL))
 		goto out;
 	if (rcvif->if_flags & IFF_NOARP)
 		goto out;
 	memcpy(&isaddr, ar_spa(ah), sizeof(isaddr));
 	memcpy(&itaddr, ar_tpa(ah), sizeof(itaddr));
 	if (m->m_flags & (M_BCAST|M_MCAST))
 		ARP_STATINC(ARP_STAT_RCVMCAST);
 	/*
 	 * Search for a matching interface address
 	 * or any address on the interface to use
 	 * as a dummy address in the rest of this function.
+	 *
 	 * First try and find the source address for early
 	 * duplicate address detection.
 	 */
 	if (in_nullhost(isaddr)) {
 		if (in_nullhost(itaddr)) /* very bogus ARP */
 			goto out;
 		find_source = false;
 		myaddr = itaddr;
 	} else {
 		find_source = true;
 		myaddr = isaddr;
+	}
 	s = pserialize_read_enter();
 again:
 	IN_ADDRHASH_READER_FOREACH(ia, myaddr.s_addr) {
 		if (!in_hosteq(ia->ia_addr.sin_addr, myaddr))
 			continue;
 #if NCARP > 0
 		if (ia->ia_ifp->if_type == IFT_CARP &&
 		    ((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) ==
 		    (IFF_UP|IFF_RUNNING))) {
 			index++;
 			/* XXX: ar_hln? */
 			if (ia->ia_ifp == rcvif && (ah->ar_hln >= 6) &&
 			    carp_iamatch(ia, ar_sha(ah),
 			    &count, index)) {
 				break;
+			}
 		} else
 #endif
 		if (ia->ia_ifp == rcvif)
 			break;
 #if NBRIDGE > 0
 		/*
 		 * If the interface we received the packet on
 		 * is part of a bridge, check to see if we need
 		 * to "bridge" the packet to ourselves at this
 		 * layer.  Note we still prefer a perfect match,
 		 * but allow this weaker match if necessary.
 		 */
 		if (rcvif->if_bridge != NULL &&
 		    rcvif->if_bridge == ia->ia_ifp->if_bridge)
 			bridge_ia = ia;
 #endif
+	}
 #if NBRIDGE > 0
 	if (ia == NULL && bridge_ia != NULL) {
 		ia = bridge_ia;
 		m_put_rcvif_psref(rcvif, &psref);
 		rcvif = NULL;
 		/* FIXME */
 		ifp = bridge_ia->ia_ifp;
+	}
 #endif
 	/* If we failed to find the source address then find
 	 * the target address. */
 	if (ia == NULL && find_source && !in_nullhost(itaddr)) {
 		find_source = false;
 		myaddr = itaddr;
 		goto again;
+	}
 	if (ia != NULL)
 		ia4_acquire(ia, &psref_ia);
 	pserialize_read_exit(s);
 	if (ah->ar_hln != ifp->if_addrlen) {
 		ARP_STATINC(ARP_STAT_RCVBADLEN);
 		log(LOG_WARNING,
 		    "arp from %s: addr len: new %d, i/f %d (ignored)\n",
 		    IN_PRINT(ipbuf, &isaddr), ah->ar_hln, ifp->if_addrlen);
 		goto out;
+	}
 	/* Only do DaD if we have a matching address. */
 	do_dad = (ia != NULL);
 	if (ia == NULL) {
 		ia = in_get_ia_on_iface_psref(isaddr, rcvif, &psref_ia);
 		if (ia == NULL) {
 			ia = in_get_ia_from_ifp_psref(ifp, &psref_ia);
 			if (ia == NULL) {
 				ARP_STATINC(ARP_STAT_RCVNOINT);
 				goto out;
+			}
+		}
+	}
 	myaddr = ia->ia_addr.sin_addr;
 	/* XXX checks for bridge case? */
 	if (!memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) {
 		ARP_STATINC(ARP_STAT_RCVBCASTSHA);
 		log(LOG_ERR,
 		    "%s: arp: link address is broadcast for IP address %s!\n",
 		    ifp->if_xname, IN_PRINT(ipbuf, &isaddr));
 		goto out;
+	}
 	/*
 	 * If the source IP address is zero, this is an RFC 5227 ARP probe
 	 */
 	if (in_nullhost(isaddr))
 		ARP_STATINC(ARP_STAT_RCVZEROSPA);
 	else if (in_hosteq(isaddr, myaddr))
 		ARP_STATINC(ARP_STAT_RCVLOCALSPA);
 	if (in_nullhost(itaddr))
 		ARP_STATINC(ARP_STAT_RCVZEROTPA);
 	/*
 	 * DAD check, RFC 5227.
 	 * Collision on sender address is always a duplicate.
 	 * Collision on target address is only a duplicate
 	 * IF the sender address is the null host (ie a DAD probe)
 	 * AND the message was broadcast
 	 * AND our address is either tentative or duplicated
 	 * If it was unicast then it's a valid Unicast Poll from RFC 1122.
 	 */
 	if (do_dad &&
 	    (in_hosteq(isaddr, myaddr) ||
 	    (in_nullhost(isaddr) && in_hosteq(itaddr, myaddr) &&
 	     m->m_flags & M_BCAST &&
 	     ia->ia4_flags & (IN_IFF_TENTATIVE | IN_IFF_DUPLICATED))))
+	{
 		struct sockaddr_dl sdl, *sdlp;
 		sdlp = sockaddr_dl_init(&sdl, sizeof(sdl),
 		    ifp->if_index, ifp->if_type,
 		    NULL, 0, ar_sha(ah), ah->ar_hln);
 		arp_dad_duplicated((struct ifaddr *)ia, sdlp);
 		goto out;
+	}
 	/*
 	 * If the target IP address is zero, ignore the packet.
 	 * This prevents the code below from trying to answer
 	 * when we are using IP address zero (booting).
 	 */
 	if (in_nullhost(itaddr))
 		goto out;
 	if (in_nullhost(isaddr))
 		goto reply;
 	if (in_hosteq(itaddr, myaddr))
 		la = arpcreate(ifp, &isaddr, NULL, 1);
 	else
 		la = arplookup(ifp, &isaddr, NULL, 1);
 	if (la == NULL)
 		goto reply;
 	if ((la->la_flags & LLE_VALID) &&
 	    memcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen))
+	{
 		char llabuf[LLA_ADDRSTRLEN], *llastr;
 		llastr = lla_snprintf(llabuf, sizeof(llabuf),
 		    ar_sha(ah), ah->ar_hln);
 		if (la->la_flags & LLE_STATIC) {
 			ARP_STATINC(ARP_STAT_RCVOVERPERM);
 			if (!log_permanent_modify)
 				goto out;
 			log(LOG_INFO,
 			    "%s tried to overwrite permanent arp info"
 			    " for %s\n", llastr, IN_PRINT(ipbuf, &isaddr));
 			goto out;
 		} else if (la->lle_tbl->llt_ifp != ifp) {
 			/* XXX should not happen? */
 			ARP_STATINC(ARP_STAT_RCVOVERINT);
 			if (!log_wrong_iface)
 				goto out;
 			log(LOG_INFO,
 			    "%s on %s tried to overwrite "
 			    "arp info for %s on %s\n",
 			    llastr,
 			    ifp->if_xname, IN_PRINT(ipbuf, &isaddr),
 			    la->lle_tbl->llt_ifp->if_xname);
 				goto out;
 		} else {
 			ARP_STATINC(ARP_STAT_RCVOVER);
 			if (log_movements)
 				log(LOG_INFO, "arp info overwritten "
 				    "for %s by %s\n",
 				    IN_PRINT(ipbuf, &isaddr), llastr);
+		}
 		rt_cmd = RTM_CHANGE;
 	} else
 		rt_cmd = la->la_flags & LLE_VALID ? 0 : RTM_ADD;
 	KASSERT(ifp->if_sadl->sdl_alen == ifp->if_addrlen);
 	KASSERT(sizeof(la->ll_addr) >= ifp->if_addrlen);
 	memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen);
 	la->la_flags |= LLE_VALID;
 	if ((la->la_flags & LLE_STATIC) == 0) {
 		la->la_expire = time_uptime + arpt_keep;
 		arp_settimer(la, arpt_keep);
+	}
 	la->la_asked = 0;
 	/* rt->rt_flags &= ~RTF_REJECT; */
 	if (rt_cmd != 0) {
 		struct sockaddr_in sin;
 		sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0);
 		rt_clonedmsg(rt_cmd, sintosa(&sin), ar_sha(ah), ifp);
+	}
 	if (la->la_hold != NULL) {
 		int n = la->la_numheld;
 		struct mbuf *m_hold, *m_hold_next;
 		struct sockaddr_in sin;
 		sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0);
 		m_hold = la->la_hold;
 		la->la_hold = NULL;
 		la->la_numheld = 0;
 		/*
 		 * We have to unlock here because if_output would call
 		 * arpresolve
 		 */
 		LLE_WUNLOCK(la);
 		ARP_STATADD(ARP_STAT_DFRSENT, n);
 		ARP_STATADD(ARP_STAT_DFRTOTAL, n);
 		for (; m_hold != NULL; m_hold = m_hold_next) {
 			m_hold_next = m_hold->m_nextpkt;
 			m_hold->m_nextpkt = NULL;
 			if_output_lock(ifp, ifp, m_hold, sintosa(&sin), NULL);
+		}
 	} else
 		LLE_WUNLOCK(la);
 	la = NULL;
 reply:
 	if (la != NULL) {
 		LLE_WUNLOCK(la);
 		la = NULL;
+	}
 	if (op != ARPOP_REQUEST) {
 		if (op == ARPOP_REPLY)
 			ARP_STATINC(ARP_STAT_RCVREPLY);
 		goto out;
+	}
 	ARP_STATINC(ARP_STAT_RCVREQUEST);
 	if (in_hosteq(itaddr, myaddr)) {
 		/* If our address is unusable, don't reply */
 		if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED))
 			goto out;
 		/* I am the target */
 		tha = ar_tha(ah);
 		if (tha)
 			memcpy(tha, ar_sha(ah), ah->ar_hln);
 		memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln);
 	} else {
 		/* Proxy ARP */
 		struct llentry *lle = NULL;
 		struct sockaddr_in sin;
 #if NCARP > 0
 		if (ifp->if_type == IFT_CARP) {
 			struct ifnet *_rcvif = m_get_rcvif(m, &s);
 			int iftype = 0;
 			if (__predict_true(_rcvif != NULL))
 				iftype = _rcvif->if_type;
 			m_put_rcvif(_rcvif, &s);
 			if (iftype != IFT_CARP)
 				goto out;
+		}
 #endif
 		tha = ar_tha(ah);
 		sockaddr_in_init(&sin, &itaddr, 0);
 		IF_AFDATA_RLOCK(ifp);
 		lle = lla_lookup(LLTABLE(ifp), 0, (struct sockaddr *)&sin);
 		IF_AFDATA_RUNLOCK(ifp);
 		if ((lle != NULL) && (lle->la_flags & LLE_PUB)) {
 			if (tha)
 				memcpy(tha, ar_sha(ah), ah->ar_hln);
 			memcpy(ar_sha(ah), &lle->ll_addr, ah->ar_hln);
 			LLE_RUNLOCK(lle);
 		} else {
 			if (lle != NULL)
 				LLE_RUNLOCK(lle);
 			goto out;
+		}
+	}
 	ia4_release(ia, &psref_ia);