--- a/src/dhcpcd.c	Mon Jan 29 10:53:05 2018 +0000
+++ b/src/dhcpcd.c	Fri Feb 02 11:24:58 2018 +0000
@@ -437,19 +437,15 @@
 		ifo->options &=
 		    ~(DHCPCD_IPV6RS | DHCPCD_DHCP6 | DHCPCD_WAITIP6);
 
-	/* We want to disable kernel interface RA as early as possible. */
+	/* We want to setup INET6 on the interface as soon as possible. */
 	if (ifp->active == IF_ACTIVE_USER &&
-	    !(ifp->ctx->options & DHCPCD_DUMPLEASE))
+	    ifo->options & DHCPCD_IPV6 &&
+	    !(ifp->ctx->options & (DHCPCD_DUMPLEASE | DHCPCD_TEST)))
 	{
-		int ra_global, ra_iface;
-
 		/* If not doing any DHCP, disable the RDNSS requirement. */
 		if (!(ifo->options & (DHCPCD_DHCP | DHCPCD_DHCP6)))
 			ifo->options &= ~DHCPCD_IPV6RA_REQRDNSS;
-		ra_global = if_checkipv6(ifp->ctx, NULL);
-		ra_iface = if_checkipv6(ifp->ctx, ifp);
-		if (ra_global == -1 || ra_iface == -1)
-			ifo->options &= ~DHCPCD_IPV6RS;
+		if_setup_inet6(ifp);
 	}
 #endif
 

--- a/src/dhcpcd.conf.5.in	Mon Jan 29 10:53:05 2018 +0000
+++ b/src/dhcpcd.conf.5.in	Fri Feb 02 11:24:58 2018 +0000
@@ -22,7 +22,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd January 8, 2018
+.Dd February 2, 2018
 .Dt DHCPCD.CONF 5
 .Os
 .Sh NAME
@@ -480,9 +480,9 @@
 .%T "RFC 3927"
 .Re
 .It Ic noipv6
-Don't attempt to configure an IPv6 address.
+Don't solicit or accept IPv6 Router Advertisements and DHCPv6.
 .It Ic noipv6rs
-Disable solicitation and receipt of IPv6 Router Advertisements.
+Don't solicit or accept IPv6 Router Advertisements.
 .It Ic nolink
 Don't receive link messages about carrier status.
 You should only set this for buggy interface drivers.

--- a/src/if-bsd.c	Mon Jan 29 10:53:05 2018 +0000
+++ b/src/if-bsd.c	Fri Feb 02 11:24:58 2018 +0000
@@ -1248,7 +1248,7 @@
 }
 
 #ifdef INET6
-#ifdef IPV6CTL_ACCEPT_RTADV
+#if defined(IPV6CTL_ACCEPT_RTADV) && !defined(ND6_IFF_ACCEPT_RTADV)
 #define get_inet6_sysctl(code) inet6_sysctl(code, 0, 0)
 #define set_inet6_sysctl(code, val) inet6_sysctl(code, val, 1)
 static int
@@ -1273,6 +1273,7 @@
 
 #ifdef IPV6_MANAGETEMPADDR
 #ifndef IPV6CTL_TEMPVLTIME
+
 #define get_inet6_sysctlbyname(code) inet6_sysctlbyname(code, 0, 0)
 #define set_inet6_sysctlbyname(code, val) inet6_sysctlbyname(code, val, 1)
 static int
@@ -1358,21 +1359,24 @@
 #ifdef IFXF_NOINET6
 	flags &= ~IFXF_NOINET6;
 #endif
-	if (!(ifp->ctx->options & DHCPCD_TEST))
+	/*
+	 * If dhcpcd is doing RS, disable RA support
+	 * in the kernel. Otherwise, leave it alone.
+	 * Logically it should be disabled regardless as dhcpcd can
+	 * do it better and the user saying no RS means no RS even the kernel,
+	 * but some crazy people want the kernel to do it still.
+	 */
+	if (ifp->options->options & DHCPCD_IPV6RS)
 		flags &= ~IFXF_AUTOCONF6;
 	if (ifr.ifr_flags == flags)
 		return 0;
-	if (ifp->ctx->options & DHCPCD_TEST) {
-		errno = EPERM;
-		return -1;
-	}
 	ifr.ifr_flags = flags;
 	return ioctl(s, SIOCSIFXFLAGS, (void *)&ifr);
 }
 #endif
 
 /* OpenBSD removed ND6 flags entirely, so we need to check for their
- * existnance. */
+ * existance. */
 #if defined(ND6_IFF_AUTO_LINKLOCAL) || \
     defined(ND6_IFF_PERFORMNUD) || \
     defined(ND6_IFF_ACCEPT_RTADV) || \
@@ -1381,147 +1385,108 @@
 #define	ND6_NDI_FLAGS
 #endif
 
-int
-if_checkipv6(struct dhcpcd_ctx *ctx, const struct interface *ifp)
+void
+if_setup_inet6(const struct interface *ifp)
 {
 	struct priv *priv;
-	int s, ra;
+	int s;
+#ifdef ND6_NDI_FLAGS
+	struct in6_ndireq nd;
+	int flags;
+#endif
 
-	priv = (struct priv *)ctx->priv;
+	priv = (struct priv *)ifp->ctx->priv;
 	s = priv->pf_inet6_fd;
 
-	if (ifp) {
 #ifdef ND6_NDI_FLAGS
-		struct in6_ndireq nd;
-		int flags;
-
-		memset(&nd, 0, sizeof(nd));
-		strlcpy(nd.ifname, ifp->name, sizeof(nd.ifname));
-		if (ioctl(s, SIOCGIFINFO_IN6, &nd) == -1)
-			return -1;
-		flags = (int)nd.ndi.flags;
+	memset(&nd, 0, sizeof(nd));
+	strlcpy(nd.ifname, ifp->name, sizeof(nd.ifname));
+	if (ioctl(s, SIOCGIFINFO_IN6, &nd) == -1)
+		logerr("%s: SIOCGIFINFO_FLAGS", ifp->name);
+	flags = (int)nd.ndi.flags;
 #endif
 
 #ifdef ND6_IFF_AUTO_LINKLOCAL
-		if (!(ctx->options & DHCPCD_TEST) &&
-		    flags & ND6_IFF_AUTO_LINKLOCAL)
-		{
-			logdebugx("%s: disabling Kernel IPv6 auto "
-			    "link-local support",
-			    ifp->name);
-			flags &= ~ND6_IFF_AUTO_LINKLOCAL;
-		}
+	/* Unlike the kernel,
+	 * dhcpcd make make a stable private address. */
+	flags &= ~ND6_IFF_AUTO_LINKLOCAL;
 #endif
 
 #ifdef ND6_IFF_PERFORMNUD
-		if ((flags & ND6_IFF_PERFORMNUD) == 0) {
-			/* NUD is kind of essential. */
-			flags |= ND6_IFF_PERFORMNUD;
-		}
-#endif
-
-#ifdef ND6_IFF_ACCEPT_RTADV
-		if (!(ctx->options & DHCPCD_TEST) &&
-		    flags & ND6_IFF_ACCEPT_RTADV)
-		{
-			logdebugx("%s: disabling Kernel IPv6 RA support",
-			    ifp->name);
-			flags &= ~ND6_IFF_ACCEPT_RTADV;
-		}
-#ifdef ND6_IFF_OVERRIDE_RTADV
-		if (!(ctx->options & DHCPCD_TEST) &&
-		    flags & ND6_IFF_OVERRIDE_RTADV)
-			flags &= ~ND6_IFF_OVERRIDE_RTADV;
-#endif
+	/* NUD is kind of essential. */
+	flags |= ND6_IFF_PERFORMNUD;
 #endif
 
 #ifdef ND6_IFF_IFDISABLED
-		flags &= ~ND6_IFF_IFDISABLED;
+	/* Ensure the interface is not disabled. */
+	flags &= ~ND6_IFF_IFDISABLED;
+#endif
+
+	/*
+	 * If dhcpcd is doing RS, disable RA support
+	 * in the kernel. Otherwise, leave it alone.
+	 * Logically it should be disabled regardless as dhcpcd can
+	 * do it better and the user saying no RS means no RS even the kernel,
+	 * but some crazy people want the kernel to do it still.
+	 */
+#ifdef ND6_IFF_ACCEPT_RTADV
+	if (ifp->options->options & DHCPCD_IPV6RS)
+		flags &= ~ND6_IFF_ACCEPT_RTADV;
+#ifdef ND6_IFF_OVERRIDE_RTADV
+	if (ifp->options->options & DHCPCD_IPV6RS)
+		flags |= ND6_IFF_OVERRIDE_RTADV;
+#endif
 #endif
 
 #ifdef ND6_NDI_FLAGS
-		if (nd.ndi.flags != (uint32_t)flags) {
-			if (ctx->options & DHCPCD_TEST) {
-				logwarnx("%s: interface not IPv6 enabled",
-				    ifp->name);
-				return -1;
-			}
-			nd.ndi.flags = (uint32_t)flags;
-			if (ioctl(s, SIOCSIFINFO_FLAGS, &nd) == -1) {
-				logerr("%s: SIOCSIFINFO_FLAGS", ifp->name);
-				return -1;
-			}
-		}
+	if (nd.ndi.flags != (uint32_t)flags) {
+		nd.ndi.flags = (uint32_t)flags;
+		if (ioctl(s, SIOCSIFINFO_FLAGS, &nd) == -1)
+			logerr("%s: SIOCSIFINFO_FLAGS", ifp->name);
+	}
 #endif
 
-		/* Enabling IPv6 by whatever means must be the
-		 * last action undertaken to ensure kernel RS and
-		 * LLADDR auto configuration are disabled where applicable. */
+	/* Enabling IPv6 by whatever means must be the
+	 * last action undertaken to ensure kernel RS and
+	 * LLADDR auto configuration are disabled where applicable. */
 #ifdef SIOCIFAFATTACH
-		if (af_attach(s, ifp, AF_INET6) == -1) {
-			logerr("%s: af_attach", ifp->name);
-			return -1;
-		}
+	if (af_attach(s, ifp, AF_INET6) == -1)
+		logerr("%s: af_attach", ifp->name);
 #endif
 
 #ifdef SIOCGIFXFLAGS
-		if (set_ifxflags(s, ifp) == -1) {
-			logerr("%s: set_ifxflags", ifp->name);
-			return -1;
-		}
+	if (set_ifxflags(s, ifp) == -1)
+		logerr("%s: set_ifxflags", ifp->name);
 #endif
 
-#ifdef ND6_IFF_ACCEPT_RTADV
-#ifdef ND6_IFF_OVERRIDE_RTADV
-		switch (flags & (ND6_IFF_ACCEPT_RTADV|ND6_IFF_OVERRIDE_RTADV)) {
-		case (ND6_IFF_ACCEPT_RTADV|ND6_IFF_OVERRIDE_RTADV):
-			return 1;
-		case ND6_IFF_ACCEPT_RTADV:
-			return ctx->ra_global;
-		default:
-			return 0;
+#if defined(IPV6CTL_ACCEPT_RTADV) && !defined(ND6_IFF_ACCEPT_RTADV)
+	/* If we cannot control ra per interface, disable it globally. */
+	if (ifp->options->options & DHCPCD_IPV6RS) {
+		int ra = get_inet6_sysctl(IPV6CTL_ACCEPT_RTADV);
+
+		if (ra == -1) {
+			if (errno != ENOENT)
+				logerr("IPV6CTL_ACCEPT_RTADV");
+		else if (ra != 0)
+			if (set_inet6_sysctl(IPV6CTL_ACCEPT_RTADV, 0) == -1)
+				logerr("IPV6CTL_ACCEPT_RTADV");
 		}
-#else
-		return flags & ND6_IFF_ACCEPT_RTADV ? 1 : 0;
+	}
 #endif
-#else
-		return ctx->ra_global;
-#endif
-	}
 
-#ifdef IPV6CTL_ACCEPT_RTADV
-	ra = get_inet6_sysctl(IPV6CTL_ACCEPT_RTADV);
-	if (ra == -1)
-		if (errno == ENOENT)
-			ra = 0;
-		else
-			logerr("IPV6CTL_ACCEPT_RTADV");
-	else if (ra != 0 && !(ctx->options & DHCPCD_TEST)) {
-		logdebugx("disabling Kernel IPv6 RA support");
-		if (set_inet6_sysctl(IPV6CTL_ACCEPT_RTADV, 0) == -1) {
-			logerr("IPV6CTL_ACCEPT_RTADV");
-			return ra;
-		}
-		ra = 0;
-#else
-	ra = 0;
-	if (!(ctx->options & DHCPCD_TEST)) {
+#if defined(IPV6CTL_ACCEPT_RTADV) || defined(ND6_IFF_ACCEPT_RTADV)
+	/* Flush the kernel knowledge of advertised routers
+	 * and prefixes so the kernel does not expire prefixes
+	 * and default routes we are trying to own. */
+	if (ifp->options->options & DHCPCD_IPV6RS) {
+		char ifname[IFNAMSIZ + 8];
+
+		strlcpy(ifname, ifp->name, sizeof(ifname));
+		if (ioctl(s, SIOCSRTRFLUSH_IN6, (void *)&ifname) == -1)
+			logwarn("SIOCSRTRFLUSH_IN6");
+		if (ioctl(s, SIOCSPFXFLUSH_IN6, (void *)&ifname) == -1)
+			logwarn("SIOCSPFXFLUSH_IN6");
+	}
 #endif
-#if defined(IPV6CTL_ACCEPT_RTADV) || defined(ND6_IFF_ACCEPT_RTADV)
-		/* Flush the kernel knowledge of advertised routers
-		 * and prefixes so the kernel does not expire prefixes
-		 * and default routes we are trying to own. */
-		char dummy[IFNAMSIZ + 8];
-
-		strlcpy(dummy, "lo0", sizeof(dummy));
-		if (ioctl(s, SIOCSRTRFLUSH_IN6, (void *)&dummy) == -1)
-			logwarn("SIOCSRTRFLUSH_IN6");
-		if (ioctl(s, SIOCSPFXFLUSH_IN6, (void *)&dummy) == -1)
-			logwarn("SIOCSPFXFLUSH_IN6");
-#endif
-	}
-
-	ctx->ra_global = ra;
-	return ra;
 }
 #endif

--- a/src/if-linux.c	Mon Jan 29 10:53:05 2018 +0000
+++ b/src/if-linux.c	Fri Feb 02 11:24:58 2018 +0000
@@ -1680,33 +1680,33 @@
 
 static const char *prefix = "/proc/sys/net/ipv6/conf";
 
-int
-if_checkipv6(struct dhcpcd_ctx *ctx, const struct interface *ifp)
+void
+if_setup_inet6(const struct interface *ifp)
 {
 	const char *ifname;
 	int ra;
 	char path[256];
 
-	if (ifp == NULL)
-		ifname = "all";
-	else if (!(ctx->options & DHCPCD_TEST)) {
-		if (if_disable_autolinklocal(ctx, ifp->index) == -1)
-			logdebug("%s: if_disable_autolinklocal",
-			    ifp->name);
-	}
-	if (ifp)
-		ifname = ifp->name;
+	/* Unlike the kernel,
+	 * dhcpcd make make a stable private address. */
+	if (if_disable_autolinklocal(ifp->ctx, ifp->index) == -1)
+		logdebug("%s: if_disable_autolinklocal", ifp->name);
+
+	/*
+	 * If dhcpcd is doing RS, disable RA support
+	 * in the kernel. Otherwise, leave it alone.
+	 * Logically it should be disabled regardless as dhcpcd can
+	 * do it better and the user saying no RS means no RS even the kernel,
+	 * but some crazy people want the kernel to do it still.
+	 */
+	if (!(ifp->options->options & DHCPCD_IPV6RS))
+		return;
 
 	snprintf(path, sizeof(path), "%s/%s/autoconf", prefix, ifname);
 	ra = check_proc_int(path);
-	if (ra != 1) {
-		if (ctx->options & DHCPCD_TEST)
-			logwarnx("%s: IPv6 kernel autoconf disabled", ifname);
-	} else if (ra != -1 && !(ctx->options & DHCPCD_TEST)) {
-		if (write_path(path, "0") == -1) {
+	if (ra != 1 && ra != -1) {
+		if (write_path(path, "0") == -1)
 			logerr("%s: %s", __func__, path);
-			return -1;
-		}
 	}
 
 	snprintf(path, sizeof(path), "%s/%s/accept_ra", prefix, ifname);
@@ -1717,16 +1717,10 @@
 		/* The sysctl probably doesn't exist, but this isn't an
 		 * error as such so just log it and continue */
 		logfunc("%s", path);
-	} else if (ra != 0 && !(ctx->options & DHCPCD_TEST)) {
-		logdebugx("%s: disabling kernel IPv6 RA support", ifname);
-		if (write_path(path, "0") == -1) {
+	} else if (ra != 0) {
+		if (write_path(path, "0") == -1)
 			logerr("%s: %s", __func__, path);
-			return ra;
-		}
-		return 0;
 	}
-
-	return ra;
 }
 
 #ifdef IPV6_MANAGETEMPADDR

--- a/src/if.h	Mon Jan 29 10:53:05 2018 +0000
+++ b/src/if.h	Fri Feb 02 11:24:58 2018 +0000
@@ -187,7 +187,7 @@
 #endif
 
 #ifdef INET6
-int if_checkipv6(struct dhcpcd_ctx *ctx, const struct interface *);
+void if_setup_inet6(const struct interface *);
 #ifdef IPV6_MANAGETEMPADDR
 int ip6_use_tempaddr(const char *ifname);
 int ip6_temp_preferred_lifetime(const char *ifname);