sync with KAME in the following points:

- fixed typos
- improved some comment descriptions
- use NULL, instead of 0, to denote a NULL pointer
- avoid embedding a magic number in the code
- use nd6log() instead of log() to record NDP-specific logs
- nuked an unnecessay white space

Obtained from: KAME
MFC after:  1 day

6 files changed, 94 insertions, 96 deletions

diff --git a/sys/netinet6/icmp6.c b/sys/netinet6/icmp6.c
index cb7d313..16f40ec 100644
--- a/sys/netinet6/icmp6.c
+++ b/sys/netinet6/icmp6.c
@@ -511,8 +511,10 @@ icmp6_input(mp, offp, proto)
 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed);
 		switch (code) {
 		case ICMP6_TIME_EXCEED_TRANSIT:
+			code = PRC_TIMXCEED_INTRANS;
+			break;
 		case ICMP6_TIME_EXCEED_REASSEMBLY:
-			code += PRC_TIMXCEED_INTRANS;
+			code = PRC_TIMXCEED_REASS;
 			break;
 		default:
 			goto badcode;
diff --git a/sys/netinet6/in6.c b/sys/netinet6/in6.c
index fcf7aed..77124f5 100644
--- a/sys/netinet6/in6.c
+++ b/sys/netinet6/in6.c
@@ -166,6 +166,12 @@ in6_ifloop_request(int cmd, struct ifaddr *ifa)
 		    e);
 	}
 
+	/*
+	 * Report the addition/removal of the address to the routing socket.
+	 * XXX: since we called rtinit for a p2p interface with a destination,
+	 *      we end up reporting twice in such a case.  Should we rather
+	 *      omit the second report?
+	 */
 	if (nrt) {
 		RT_LOCK(nrt);
 		/*
@@ -180,14 +186,6 @@ in6_ifloop_request(int cmd, struct ifaddr *ifa)
 			nrt->rt_ifa = ifa;
 		}
 
-		/*
-		 * Report the addition/removal of the address to the routing
-		 * socket.
-		 *
-		 * XXX: since we called rtinit for a p2p interface with a
-		 *      destination, we end up reporting twice in such a case.
-		 *      Should we rather omit the second report?
-		 */
 		rt_newaddrmsg(cmd, ifa, e, nrt);
 		if (cmd == RTM_DELETE) {
 			rtfree(nrt);
@@ -239,8 +237,7 @@ in6_ifremloop(struct ifaddr *ifa)
 	 * (see comments in net/net_osdep.h).  Even for variants that do remove
 	 * cloned routes, they could fail to remove the cloned routes when
 	 * we handle multple addresses that share a common prefix.
-	 * So, we should remove the route corresponding to the deleted address
-	 * regardless of the result of in6_is_ifloop_auto().
+	 * So, we should remove the route corresponding to the deleted address.
 	 */
 
 	/*
@@ -430,8 +427,7 @@ in6_control(so, cmd, data, ifp, td)
 	case SIOCSIFNETMASK_IN6:
 		/*
 		 * Since IPv6 allows a node to assign multiple addresses
-		 * on a single interface, SIOCSIFxxx ioctls are not suitable
-		 * and should be unused.
+		 * on a single interface, SIOCSIFxxx ioctls are deprecated.
 		 */
 		/* we decided to obsolete this command (20000704) */
 		return (EINVAL);
@@ -439,10 +435,10 @@ in6_control(so, cmd, data, ifp, td)
 	case SIOCDIFADDR_IN6:
 		/*
 		 * for IPv4, we look for existing in_ifaddr here to allow
-		 * "ifconfig if0 delete" to remove first IPv4 address on the
-		 * interface.  For IPv6, as the spec allow multiple interface
-		 * address from the day one, we consider "remove the first one"
-		 * semantics to be not preferable.
+		 * "ifconfig if0 delete" to remove the first IPv4 address on
+		 * the interface.  For IPv6, as the spec allows multiple
+		 * interface address from the day one, we consider "remove the
+		 * first one" semantics to be not preferable.
 		 */
 		if (ia == NULL)
 			return (EADDRNOTAVAIL);
@@ -981,6 +977,7 @@ in6_update_ifa(ifp, ifra, ia)
 	 * not just go to unlink.
 	 */
 
+	/* Join necessary multicast groups */
 	if ((ifp->if_flags & IFF_MULTICAST) != 0) {
 		struct sockaddr_in6 mltaddr, mltmask;
 		struct in6_multi *in6m;
@@ -988,7 +985,7 @@ in6_update_ifa(ifp, ifra, ia)
 
 		/* join solicited multicast addr for new host id */
 		bzero(&llsol, sizeof(struct in6_addr));
-		llsol.s6_addr16[0] = htons(0xff02);
+		llsol.s6_addr32[0] = IPV6_ADDR_INT32_MLL;
 		llsol.s6_addr32[1] = 0;
 		llsol.s6_addr32[2] = htonl(1);
 		llsol.s6_addr32[3] = ifra->ifra_addr.sin6_addr.s6_addr32[3];
@@ -1013,6 +1010,7 @@ in6_update_ifa(ifp, ifra, ia)
 		mltmask.sin6_len = sizeof(struct sockaddr_in6);
 		mltmask.sin6_family = AF_INET6;
 		mltmask.sin6_addr = in6mask32;
+#define	MLTMASK_LEN  4	/* mltmask's masklen (=32bit=4octet) */
 
 		/*
 		 * join link-local all-nodes address
@@ -1033,12 +1031,9 @@ in6_update_ifa(ifp, ifra, ia)
 		 */
 		rt = rtalloc1((struct sockaddr *)&mltaddr, 0, 0UL);
 		if (rt) {
-			/*
-			 * 32bit came from "mltmask"
-			 */
 			if (memcmp(&mltaddr.sin6_addr,
 			    &((struct sockaddr_in6 *)rt_key(rt))->sin6_addr,
-			    32 / 8)) {
+			    MLTMASK_LEN)) {
 				RTFREE_LOCKED(rt);
 				rt = NULL;
 			}
@@ -1100,10 +1095,9 @@ in6_update_ifa(ifp, ifra, ia)
 		/* XXX: again, do we really need the route? */
 		rt = rtalloc1((struct sockaddr *)&mltaddr, 0, 0UL);
 		if (rt) {
-			/* 32bit came from "mltmask" */
 			if (memcmp(&mltaddr.sin6_addr,
 			    &((struct sockaddr_in6 *)rt_key(rt))->sin6_addr,
-			    32 / 8)) {
+			    MLTMASK_LEN)) {
 				RTFREE_LOCKED(rt);
 				rt = NULL;
 			}
@@ -1130,6 +1124,7 @@ in6_update_ifa(ifp, ifra, ia)
 				goto cleanup;
 			}
 		}
+#undef	MLTMASK_LEN
 	}
 
 	return (error);
@@ -1187,7 +1182,7 @@ in6_purgeaddr(ifa)
 		struct in6_multi *in6m;
 		struct in6_addr llsol;
 		bzero(&llsol, sizeof(struct in6_addr));
-		llsol.s6_addr16[0] = htons(0xff02);
+		llsol.s6_addr32[0] = IPV6_ADDR_INT32_MLL;
 		llsol.s6_addr32[1] = 0;
 		llsol.s6_addr32[2] = htonl(1);
 		llsol.s6_addr32[3] =
diff --git a/sys/netinet6/in6_ifattach.c b/sys/netinet6/in6_ifattach.c
index f401896..d9244dc 100644
--- a/sys/netinet6/in6_ifattach.c
+++ b/sys/netinet6/in6_ifattach.c
@@ -186,8 +186,8 @@ generate_tmp_ifid(seed0, seed1, ret)
 	 * use a random non-zero value as the last resort.
 	 */
 	if (bcmp(nullbuf, ret, sizeof(nullbuf)) == 0) {
-		log(LOG_INFO,
-		    "generate_tmp_ifid: computed MD5 value is zero.\n");
+		nd6log((LOG_INFO,
+		    "generate_tmp_ifid: computed MD5 value is zero.\n"));
 
 		val32 = arc4random();
 		val32 = 1 + (val32 % (0xffffffff - 1));
@@ -467,7 +467,7 @@ in6_ifattach_linklocal(ifp, altifp)
 
 	/*
 	 * Now call in6_update_ifa() to do a bunch of procedures to configure
-	 * a link-local address. We can set NULL to the 3rd argument, because
+	 * a link-local address. We can set the 3rd argument to NULL, because
 	 * we know there's no other link-local address on the interface
 	 * and therefore we are adding one (instead of updating one).
 	 */
@@ -479,10 +479,10 @@ in6_ifattach_linklocal(ifp, altifp)
 		 * suppress it.  (jinmei@kame.net 20010130)
 		 */
 		if (error != EAFNOSUPPORT)
-			log(LOG_NOTICE, "in6_ifattach_linklocal: failed to "
+			nd6log((LOG_NOTICE, "in6_ifattach_linklocal: failed to "
 			    "configure a link-local address on %s "
 			    "(errno=%d)\n",
-			    if_name(ifp), error);
+			    if_name(ifp), error));
 		return (-1);
 	}
 
@@ -590,9 +590,9 @@ in6_ifattach_loopback(ifp)
 	 * NULL to the 3rd arg.
 	 */
 	if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0) {
-		log(LOG_ERR, "in6_ifattach_loopback: failed to configure "
+		nd6log((LOG_ERR, "in6_ifattach_loopback: failed to configure "
 		    "the loopback address on %s (errno=%d)\n",
-		    if_name(ifp), error);
+		    if_name(ifp), error));
 		return (-1);
 	}
 
@@ -643,7 +643,7 @@ in6_nigroup(ifp, name, namelen, in6)
 	MD5Final(digest, &ctxt);
 
 	bzero(in6, sizeof(*in6));
-	in6->s6_addr16[0] = htons(0xff02);
+	in6->s6_addr16[0] = IPV6_ADDR_INT16_MLL;
 	in6->s6_addr8[11] = 2;
 	bcopy(digest, &in6->s6_addr32[3], sizeof(in6->s6_addr32[3]));
 	if (in6_setscope(in6, ifp, NULL))
@@ -695,9 +695,9 @@ in6_ifattach(ifp, altifp)
 	 * usually, we require multicast capability to the interface
 	 */
 	if ((ifp->if_flags & IFF_MULTICAST) == 0) {
-		log(LOG_INFO, "in6_ifattach: "
+		nd6log((LOG_INFO, "in6_ifattach: "
 		    "%s is not multicast capable, IPv6 not enabled\n",
-		    if_name(ifp));
+		    if_name(ifp)));
 		return;
 	}
 
diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
index 6b9f734..46b1ea1 100644
--- a/sys/netinet6/nd6.c
+++ b/sys/netinet6/nd6.c
@@ -206,7 +206,7 @@ nd6_setmtu0(ifp, ndi)
 	case IFT_FDDI:
 		ndi->maxmtu = MIN(FDDIIPMTU, ifp->if_mtu); /* RFC2467 */
 		break;
-	 case IFT_ISO88025:
+	case IFT_ISO88025:
 		 ndi->maxmtu = MIN(ISO88025_MAX_MTU, ifp->if_mtu);
 		 break;
 	default:
@@ -260,11 +260,11 @@ nd6_option(ndopts)
 	struct nd_opt_hdr *nd_opt;
 	int olen;
 
-	if (!ndopts)
+	if (ndopts == NULL)
 		panic("ndopts == NULL in nd6_option");
-	if (!ndopts->nd_opts_last)
+	if (ndopts->nd_opts_last == NULL)
 		panic("uninitialized ndopts in nd6_option");
-	if (!ndopts->nd_opts_search)
+	if (ndopts->nd_opts_search == NULL)
 		return NULL;
 	if (ndopts->nd_opts_done)
 		return NULL;
@@ -312,16 +312,16 @@ nd6_options(ndopts)
 	struct nd_opt_hdr *nd_opt;
 	int i = 0;
 
-	if (!ndopts)
+	if (ndopts == NULL)
 		panic("ndopts == NULL in nd6_options");
-	if (!ndopts->nd_opts_last)
+	if (ndopts->nd_opts_last == NULL)
 		panic("uninitialized ndopts in nd6_options");
-	if (!ndopts->nd_opts_search)
+	if (ndopts->nd_opts_search == NULL)
 		return 0;
 
 	while (1) {
 		nd_opt = nd6_option(ndopts);
-		if (!nd_opt && !ndopts->nd_opts_last) {
+		if (nd_opt == NULL && ndopts->nd_opts_last == NULL) {
 			/*
 			 * Message validation requires that all included
 			 * options have a length that is greater than zero.
@@ -331,7 +331,7 @@ nd6_options(ndopts)
 			return -1;
 		}
 
-		if (!nd_opt)
+		if (nd_opt == NULL)
 			goto skip1;
 
 		switch (nd_opt->nd_opt_type) {
@@ -775,10 +775,10 @@ nd6_lookup(addr6, create, ifp)
 			 * destination and allocate an interface route.
 			 */
 			RTFREE_LOCKED(rt);
-			rt = 0;
+			rt = NULL;
 		}
 	}
-	if (!rt) {
+	if (rt == NULL) {
 		if (create && ifp) {
 			int e;
 
@@ -838,11 +838,10 @@ nd6_lookup(addr6, create, ifp)
 	    rt->rt_gateway->sa_family != AF_LINK || rt->rt_llinfo == NULL ||
 	    (ifp && rt->rt_ifa->ifa_ifp != ifp)) {
 		if (create) {
-			log(LOG_DEBUG,
+			nd6log((LOG_DEBUG,
 			    "nd6_lookup: failed to lookup %s (if = %s)\n",
 			    ip6_sprintf(addr6),
-			    ifp ? if_name(ifp) : "unspec");
-			/* xxx more logs... kazu */
+			    ifp ? if_name(ifp) : "unspec"));
 		}
 		RT_UNLOCK(rt);
 		return (NULL);
@@ -1050,16 +1049,16 @@ nd6_nud_hint(rt, dst6, force)
 	 * If the caller specified "rt", use that.  Otherwise, resolve the
 	 * routing table by supplied "dst6".
 	 */
-	if (!rt) {
-		if (!dst6)
+	if (rt == NULL) {
+		if (dst6 == NULL)
 			return;
-		if (!(rt = nd6_lookup(dst6, 0, NULL)))
+		if ((rt = nd6_lookup(dst6, 0, NULL)) == NULL)
 			return;
 	}
 
 	if ((rt->rt_flags & RTF_GATEWAY) != 0 ||
 	    (rt->rt_flags & RTF_LLINFO) == 0 ||
-	    !rt->rt_llinfo || !rt->rt_gateway ||
+	    rt->rt_llinfo == NULL || rt->rt_gateway == NULL ||
 	    rt->rt_gateway->sa_family != AF_LINK) {
 		/* This is not a host route. */
 		return;
@@ -1217,7 +1216,7 @@ nd6_rtrequest(req, rt, info)
 		 */
 		R_Malloc(ln, struct llinfo_nd6 *, sizeof(*ln));
 		rt->rt_llinfo = (caddr_t)ln;
-		if (!ln) {
+		if (ln == NULL) {
 			log(LOG_DEBUG, "nd6_rtrequest: malloc failed\n");
 			break;
 		}
@@ -1290,7 +1289,7 @@ nd6_rtrequest(req, rt, info)
 				int error;
 
 				llsol = SIN6(rt_key(rt))->sin6_addr;
-				llsol.s6_addr16[0] = htons(0xff02);
+				llsol.s6_addr32[0] = IPV6_ADDR_INT32_MLL;
 				llsol.s6_addr32[1] = 0;
 				llsol.s6_addr32[2] = htonl(1);
 				llsol.s6_addr8[12] = 0xff;
@@ -1306,7 +1305,7 @@ nd6_rtrequest(req, rt, info)
 		break;
 
 	case RTM_DELETE:
-		if (!ln)
+		if (ln == NULL)
 			break;
 		/* leave from solicited node multicast for proxy ND */
 		if ((rt->rt_flags & RTF_ANNOUNCE) != 0 &&
@@ -1315,7 +1314,7 @@ nd6_rtrequest(req, rt, info)
 			struct in6_multi *in6m;
 
 			llsol = SIN6(rt_key(rt))->sin6_addr;
-			llsol.s6_addr16[0] = htons(0xff02);
+			llsol.s6_addr32[0] = IPV6_ADDR_INT32_MLL;
 			llsol.s6_addr32[1] = 0;
 			llsol.s6_addr32[2] = htonl(1);
 			llsol.s6_addr8[12] = 0xff;
@@ -1426,24 +1425,26 @@ nd6_ioctl(cmd, data, ifp)
 
 		break;
 	case OSIOCGIFINFO_IN6:
+#define ND	ndi->ndi
 		/* XXX: old ndp(8) assumes a positive value for linkmtu. */
-		bzero(&ndi->ndi, sizeof(ndi->ndi));
-		ndi->ndi.linkmtu = IN6_LINKMTU(ifp);
-		ndi->ndi.maxmtu = ND_IFINFO(ifp)->maxmtu;
-		ndi->ndi.basereachable = ND_IFINFO(ifp)->basereachable;
-		ndi->ndi.reachable = ND_IFINFO(ifp)->reachable;
-		ndi->ndi.retrans = ND_IFINFO(ifp)->retrans;
-		ndi->ndi.flags = ND_IFINFO(ifp)->flags;
-		ndi->ndi.recalctm = ND_IFINFO(ifp)->recalctm;
-		ndi->ndi.chlim = ND_IFINFO(ifp)->chlim;
+		bzero(&ND, sizeof(ND));
+		ND.linkmtu = IN6_LINKMTU(ifp);
+		ND.maxmtu = ND_IFINFO(ifp)->maxmtu;
+		ND.basereachable = ND_IFINFO(ifp)->basereachable;
+		ND.reachable = ND_IFINFO(ifp)->reachable;
+		ND.retrans = ND_IFINFO(ifp)->retrans;
+		ND.flags = ND_IFINFO(ifp)->flags;
+		ND.recalctm = ND_IFINFO(ifp)->recalctm;
+		ND.chlim = ND_IFINFO(ifp)->chlim;
 		break;
 	case SIOCGIFINFO_IN6:
-		ndi->ndi = *ND_IFINFO(ifp);
-		ndi->ndi.linkmtu = IN6_LINKMTU(ifp);
+		ND = *ND_IFINFO(ifp);
+		ND.linkmtu = IN6_LINKMTU(ifp);
 		break;
 	case SIOCSIFINFO_FLAGS:
-		ND_IFINFO(ifp)->flags = ndi->ndi.flags;
+		ND_IFINFO(ifp)->flags = ND.flags;
 		break;
+#undef ND
 	case SIOCSNDFLUSH_IN6:	/* XXX: the ioctl name is confusing... */
 		/* flush default router list */
 		/*
@@ -1559,9 +1560,9 @@ nd6_cache_lladdr(ifp, from, lladdr, lladdrlen, type, code)
 	int llchange;
 	int newstate = 0;
 
-	if (!ifp)
+	if (ifp == NULL)
 		panic("ifp == NULL in nd6_cache_lladdr");
-	if (!from)
+	if (from == NULL)
 		panic("from == NULL in nd6_cache_lladdr");
 
 	/* nothing must be updated for unspecified address */
@@ -1579,7 +1580,7 @@ nd6_cache_lladdr(ifp, from, lladdr, lladdrlen, type, code)
 	 */
 
 	rt = nd6_lookup(from, 0, ifp);
-	if (!rt) {
+	if (rt == NULL) {
 #if 0
 		/* nothing must be done if there's no lladdr */
 		if (!lladdr || !lladdrlen)
@@ -1595,7 +1596,7 @@ nd6_cache_lladdr(ifp, from, lladdr, lladdrlen, type, code)
 		is_newentry = 0;
 	}
 
-	if (!rt)
+	if (rt == NULL)
 		return NULL;
 	if ((rt->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) != RTF_LLINFO) {
 fail:
@@ -1603,9 +1604,9 @@ fail:
 		return NULL;
 	}
 	ln = (struct llinfo_nd6 *)rt->rt_llinfo;
-	if (!ln)
+	if (ln == NULL)
 		goto fail;
-	if (!rt->rt_gateway)
+	if (rt->rt_gateway == NULL)
 		goto fail;
 	if (rt->rt_gateway->sa_family != AF_LINK)
 		goto fail;
@@ -1641,15 +1642,15 @@ fail:
 	}
 
 	if (!is_newentry) {
-		if ((!olladdr && lladdr) ||		/* (3) */
-		    (olladdr && lladdr && llchange)) {	/* (5) */
+		if ((!olladdr && lladdr != NULL) ||	/* (3) */
+		    (olladdr && lladdr != NULL && llchange)) {	/* (5) */
 			do_update = 1;
 			newstate = ND6_LLINFO_STALE;
 		} else					/* (1-2,4) */
 			do_update = 0;
 	} else {
 		do_update = 1;
-		if (!lladdr)				/* (6) */
+		if (lladdr == NULL)			/* (6) */
 			newstate = ND6_LLINFO_NOSTATE;
 		else					/* (7) */
 			newstate = ND6_LLINFO_STALE;
@@ -1900,7 +1901,7 @@ again:
 		    (rt = nd6_lookup(&dst->sin6_addr, 1, ifp)) != NULL)
 			ln = (struct llinfo_nd6 *)rt->rt_llinfo;
 	}
-	if (!ln || !rt) {
+	if (ln == NULL || rt == NULL) {
 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0 &&
 		    !(ND_IFINFO(ifp)->flags & ND6_IFF_PERFORMNUD)) {
 			log(LOG_DEBUG,
diff --git a/sys/netinet6/nd6_nbr.c b/sys/netinet6/nd6_nbr.c
index 96db8fa..e792443 100644
--- a/sys/netinet6/nd6_nbr.c
+++ b/sys/netinet6/nd6_nbr.c
@@ -203,14 +203,14 @@ nd6_ns_input(m, off, icmp6len)
 #ifdef DEV_CARP
 	if (ifp->if_carp)
 		ifa = carp_iamatch6(ifp->if_carp, &taddr6);
-	if (!ifa)
+	if (ifa == NULL)
 		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
 #else
 	ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
 #endif
 
 	/* (2) check. */
-	if (!ifa) {
+	if (ifa == NULL) {
 		struct rtentry *rt;
 		struct sockaddr_in6 tsin6;
 		int need_proxy;
@@ -671,7 +671,7 @@ nd6_na_input(m, off, icmp6len)
 		 * If the link-layer has address, and no lladdr option came,
 		 * discard the packet.
 		 */
-		if (ifp->if_addrlen && !lladdr)
+		if (ifp->if_addrlen && lladdr == NULL)
 			goto freeit;
 
 		/*
@@ -704,7 +704,7 @@ nd6_na_input(m, off, icmp6len)
 		/*
 		 * Check if the link-layer address has changed or not.
 		 */
-		if (!lladdr)
+		if (lladdr == NULL)
 			llchange = 0;
 		else {
 			if (sdl->sdl_alen) {
@@ -735,7 +735,7 @@ nd6_na_input(m, off, icmp6len)
 		 *	1	1	y	n	(2a) L *->REACHABLE
 		 *	1	1	y	y	(2a) L *->REACHABLE
 		 */
-		if (!is_override && (lladdr && llchange)) {	   /* (1) */
+		if (!is_override && (lladdr != NULL && llchange)) {   /* (1) */
 			/*
 			 * If state is REACHABLE, make it STALE.
 			 * no other updates should be done.
@@ -746,12 +746,12 @@ nd6_na_input(m, off, icmp6len)
 			}
 			goto freeit;
 		} else if (is_override				   /* (2a) */
-			|| (!is_override && (lladdr && !llchange)) /* (2b) */
-			|| !lladdr) {				   /* (2c) */
+			|| (!is_override && (lladdr != NULL && !llchange)) /* (2b) */
+			|| lladdr == NULL) {			   /* (2c) */
 			/*
 			 * Update link-local address, if any.
 			 */
-			if (lladdr) {
+			if (lladdr != NULL) {
 				sdl->sdl_alen = ifp->if_addrlen;
 				bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen);
 			}
@@ -769,7 +769,7 @@ nd6_na_input(m, off, icmp6len)
 					    ND_IFINFO(ifp)->reachable;
 				}
 			} else {
-				if (lladdr && llchange) {
+				if (lladdr != NULL && llchange) {
 					ln->ln_state = ND6_LLINFO_STALE;
 					ln->ln_expire = time_second + nd6_gctimer;
 				}
@@ -1120,7 +1120,7 @@ nd6_dad_start(ifa, tick)
 		ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
 		return;
 	}
-	if (!ifa->ifa_ifp)
+	if (ifa->ifa_ifp == NULL)
 		panic("nd6_dad_start: ifa->ifa_ifp == NULL");
 	if (!(ifa->ifa_ifp->if_flags & IFF_UP)) {
 		return;
@@ -1372,7 +1372,7 @@ nd6_dad_ns_input(ifa)
 	struct dadq *dp;
 	int duplicate;
 
-	if (!ifa)
+	if (ifa == NULL)
 		panic("ifa == NULL in nd6_dad_ns_input");
 
 	ia = (struct in6_ifaddr *)ifa;
@@ -1394,7 +1394,7 @@ nd6_dad_ns_input(ifa)
 	 * if I'm yet to start DAD, someone else started using this address
 	 * first.  I have a duplicate and you win.
 	 */
-	if (!dp || dp->dad_ns_ocount == 0)
+	if (dp == NULL || dp->dad_ns_ocount == 0)
 		duplicate++;
 
 	/* XXX more checks for loopback situation - see nd6_dad_timer too */
@@ -1418,7 +1418,7 @@ nd6_dad_na_input(ifa)
 {
 	struct dadq *dp;
 
-	if (!ifa)
+	if (ifa == NULL)
 		panic("ifa == NULL in nd6_dad_na_input");
 
 	dp = nd6_dad_find(ifa);
diff --git a/sys/netinet6/nd6_rtr.c b/sys/netinet6/nd6_rtr.c
index 3b53536..ccdbf29 100644
--- a/sys/netinet6/nd6_rtr.c
+++ b/sys/netinet6/nd6_rtr.c
@@ -1239,7 +1239,7 @@ pfxlist_onlink_check()
 			break;
 	}
 
-	if (pr) {
+	if (pr == NULL) {
 		/*
 		 * There is at least one prefix that has a reachable router.
 		 * Detach prefixes which have no reachable advertising
@@ -1300,7 +1300,7 @@ pfxlist_onlink_check()
 			if ((e = nd6_prefix_offlink(pr)) != 0) {
 				nd6log((LOG_ERR,
 				    "pfxlist_onlink_check: failed to "
-				    "make %s/%d offlink, errno=%d\n",
+				    "make %s/%d onlink, errno=%d\n",
 				    ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
 				    pr->ndpr_plen, e));
 			}
@@ -1382,8 +1382,8 @@ nd6_prefix_onlink(pr)
 	if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
 		nd6log((LOG_ERR,
 		    "nd6_prefix_onlink: %s/%d is already on-link\n",
-		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen);
-		return (EEXIST));
+		    ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen));
+		return (EEXIST);
 	}
 
 	/*