device: announce the managed IPv6 configuration with ipv6.method=shared

This esentially causes us to announce the prefixes of the addresses we
own and the DNS configuration.

Currently the only way to get the IPv6 configuration on such device is
manual setting in the connection. This will change with IPv6 prefix
delegation.

src/devices/nm-device.c

@@ -1811,6 +1811,73 @@ device_recheck_slave_status (NMDevice *self, const NMPlatformLink *plink)
 	}
 }
 
+static void
+ndisc_set_router_config (NMNDisc *ndisc, NMDevice *self)
+{
+	NMDevicePrivate *priv = NM_DEVICE_GET_PRIVATE (self);
+	guint32 now = nm_utils_get_monotonic_timestamp_s ();
+	GArray *addresses, *dns_servers, *dns_domains;
+	guint len, i;
+
+	if (nm_ndisc_get_node_type (ndisc) != NM_NDISC_NODE_TYPE_ROUTER)
+		return;
+
+	/* Addresses whose prefixes we announce. */
+	len = nm_ip6_config_get_num_addresses (priv->ip6_config);
+	addresses = g_array_sized_new (FALSE, FALSE, sizeof (NMNDiscAddress), len);
+	for (i = 0; i < len; i++) {
+		const NMPlatformIP6Address *addr = nm_ip6_config_get_address (priv->ip6_config, i);
+		NMNDiscAddress *ndisc_addr;
+
+		if (IN6_IS_ADDR_LINKLOCAL (&addr->address))
+			continue;
+
+		if (   addr->n_ifa_flags & IFA_F_TENTATIVE
+		    || addr->n_ifa_flags & IFA_F_DADFAILED)
+			continue;
+
+		if (addr->plen != 64)
+			continue;
+
+		ndisc_addr = &g_array_index (addresses, NMNDiscAddress, addresses->len-1);
+		ndisc_addr->address = addr->address;
+		ndisc_addr->timestamp = addr->timestamp;
+		ndisc_addr->lifetime = addr->lifetime;
+		ndisc_addr->preferred = addr->preferred;
+	}
+
+	/* DNS servers. */
+	len = nm_ip6_config_get_num_nameservers (priv->ip6_config);
+	dns_servers = g_array_sized_new (FALSE, FALSE, sizeof (NMNDiscDNSServer), len);
+	for (i = 0; i < len; i++) {
+		const struct in6_addr *nameserver = nm_ip6_config_get_nameserver (priv->ip6_config, i);
+		NMNDiscDNSServer *ndisc_nameserver;
+
+		ndisc_nameserver = &g_array_index (dns_servers, NMNDiscDNSServer, dns_servers->len-1);
+		ndisc_nameserver->address = *nameserver;
+		ndisc_nameserver->timestamp = now;
+		ndisc_nameserver->lifetime = NM_NDISC_ROUTER_LIFETIME;
+	}
+
+	/* DNS domains. */
+	len = nm_ip6_config_get_num_searches (priv->ip6_config);
+	dns_domains = g_array_sized_new (FALSE, FALSE, sizeof (NMNDiscDNSDomain), len);
+	for (i = 0; i < len; i++) {
+		const char *search = nm_ip6_config_get_search (priv->ip6_config, i);
+		NMNDiscDNSDomain *ndisc_search;
+
+		ndisc_search = &g_array_index (dns_domains, NMNDiscDNSDomain, dns_domains->len-1);
+		ndisc_search->domain = g_strdup (search);
+		ndisc_search->timestamp = now;
+		ndisc_search->lifetime = NM_NDISC_ROUTER_LIFETIME;
+	}
+
+	nm_ndisc_set_config (ndisc, addresses, dns_servers, dns_domains);
+	g_array_free (addresses, TRUE);
+	g_array_free (dns_servers, TRUE);
+	g_array_free (dns_domains, TRUE);
+}
+
 static gboolean
 device_link_changed (NMDevice *self)
 {
@@ -5266,6 +5333,7 @@ connection_ip6_method_requires_carrier (NMConnection *connection,
 	static const char *ip6_carrier_methods[] = {
 		NM_SETTING_IP6_CONFIG_METHOD_AUTO,
 		NM_SETTING_IP6_CONFIG_METHOD_DHCP,
+		NM_SETTING_IP6_CONFIG_METHOD_SHARED,
 		NM_SETTING_IP6_CONFIG_METHOD_LINK_LOCAL,
 		NULL
 	};
@@ -6043,7 +6111,8 @@ linklocal6_complete (NMDevice *self)
 
 	_LOGD (LOGD_DEVICE, "linklocal6: waiting for link-local addresses successful, continue with method %s", method);
 
-	if (strcmp (method, NM_SETTING_IP6_CONFIG_METHOD_AUTO) == 0) {
+	if (   strcmp (method, NM_SETTING_IP6_CONFIG_METHOD_AUTO) == 0
+	    || strcmp (method, NM_SETTING_IP6_CONFIG_METHOD_SHARED) == 0) {
 		if (!addrconf6_start_with_link_ready (self)) {
 			/* Time out IPv6 instead of failing the entire activation */
 			nm_device_activate_schedule_ip6_config_timeout (self);
@@ -6406,10 +6475,23 @@ addrconf6_start_with_link_ready (NMDevice *self)
 	if (!ip6_config_merge_and_apply (self, TRUE, NULL))
 		_LOGW (LOGD_IP6, "failed to apply manual IPv6 configuration");
 
-	nm_device_ipv6_sysctl_set (self, "accept_ra", "1");
+	/* XXX: These sysctls would probably be better set by the lndp ndisc itself. */
-	nm_device_ipv6_sysctl_set (self, "accept_ra_defrtr", "0");
+	switch (nm_ndisc_get_node_type (priv->ndisc)) {
-	nm_device_ipv6_sysctl_set (self, "accept_ra_pinfo", "0");
+	case NM_NDISC_NODE_TYPE_HOST:
-	nm_device_ipv6_sysctl_set (self, "accept_ra_rtr_pref", "0");
+		/* Accepting prefixes from discovered routers. */
+		nm_device_ipv6_sysctl_set (self, "accept_ra", "1");
+		nm_device_ipv6_sysctl_set (self, "accept_ra_defrtr", "0");
+		nm_device_ipv6_sysctl_set (self, "accept_ra_pinfo", "0");
+		nm_device_ipv6_sysctl_set (self, "accept_ra_rtr_pref", "0");
+		break;
+	case NM_NDISC_NODE_TYPE_ROUTER:
+		/* We're the router. */
+		nm_device_ipv6_sysctl_set (self, "forwarding", "1");
+		nm_device_activate_schedule_ip6_config_result (self);
+		break;
+	default:
+		g_assert_not_reached ();
+	}
 
 	priv->ndisc_changed_id = g_signal_connect (priv->ndisc,
 	                                           NM_NDISC_CONFIG_RECEIVED,
@@ -6420,10 +6502,26 @@ addrconf6_start_with_link_ready (NMDevice *self)
 	                                           G_CALLBACK (ndisc_ra_timeout),
 	                                           self);
 
+	ndisc_set_router_config (priv->ndisc, self);
 	nm_ndisc_start (priv->ndisc);
 	return TRUE;
 }
 
+static NMNDiscNodeType
+ndisc_node_type (NMDevice *self)
+{
+	NMConnection *connection;
+
+	connection = nm_device_get_applied_connection (self);
+	g_assert (connection);
+
+	if (strcmp (nm_utils_get_ip_config_method (connection, NM_TYPE_SETTING_IP6_CONFIG),
+	            NM_SETTING_IP4_CONFIG_METHOD_SHARED) == 0)
+		return NM_NDISC_NODE_TYPE_ROUTER;
+	else
+		return NM_NDISC_NODE_TYPE_HOST;
+}
+
 static gboolean
 addrconf6_start (NMDevice *self, NMSettingIP6ConfigPrivacy use_tempaddr)
 {
@@ -6455,7 +6553,7 @@ addrconf6_start (NMDevice *self, NMSettingIP6ConfigPrivacy use_tempaddr)
 		                                 stable_type,
 		                                 stable_id,
 		                                 nm_setting_ip6_config_get_addr_gen_mode (s_ip6),
-		                                 NM_NDISC_NODE_TYPE_HOST,
+		                                 ndisc_node_type (self),
 		                                 &error);
 	}
 	if (!priv->ndisc) {
@@ -6508,6 +6606,7 @@ static const char *ip6_properties_to_save[] = {
 	"accept_ra_defrtr",
 	"accept_ra_pinfo",
 	"accept_ra_rtr_pref",
+	"forwarding",
 	"disable_ipv6",
 	"hop_limit",
 	"use_tempaddr",
@@ -6753,7 +6852,8 @@ act_stage3_ip6_config_start (NMDevice *self,
 
 	ip6_privacy = _ip6_privacy_get (self);
 
-	if (strcmp (method, NM_SETTING_IP6_CONFIG_METHOD_AUTO) == 0) {
+	if (   strcmp (method, NM_SETTING_IP6_CONFIG_METHOD_AUTO) == 0
+	    || strcmp (method, NM_SETTING_IP6_CONFIG_METHOD_SHARED) == 0) {
 		if (!addrconf6_start (self, ip6_privacy)) {
 			/* IPv6 might be disabled; allow IPv4 to proceed */
 			ret = NM_ACT_STAGE_RETURN_IP_FAIL;
@@ -6773,8 +6873,6 @@ act_stage3_ip6_config_start (NMDevice *self,
 	} else
 		_LOGW (LOGD_IP6, "unhandled IPv6 config method '%s'; will fail", method);
 
-	/* Other methods (shared) aren't implemented yet */
-
 	if (   ret != NM_ACT_STAGE_RETURN_FAILURE
 	    && !nm_device_uses_assumed_connection (self)) {
 		switch (ip6_privacy) {
@@ -8800,6 +8898,9 @@ nm_device_set_ip6_config (NMDevice *self,
 		}
 
 		nm_device_queue_recheck_assume (self);
+
+		if (priv->ndisc)
+			ndisc_set_router_config (priv->ndisc, self);
 	}
 
 	if (reason)
@@ -11116,6 +11217,7 @@ ip6_managed_setup (NMDevice *self)
 	nm_device_ipv6_sysctl_set (self, "accept_ra_pinfo", "0");
 	nm_device_ipv6_sysctl_set (self, "accept_ra_rtr_pref", "0");
 	nm_device_ipv6_sysctl_set (self, "use_tempaddr", "0");
+	nm_device_ipv6_sysctl_set (self, "forwarding", "0");
 }
 
 static void