ifcfg-rh: add DHCPV6_HOSTNAME and DHCPV6_SEND_HOSTNAME vars

Currently ipv4 and ipv6 settings share the ifcfg plugin vars for the
dhcp-hostname and dhcp-send-hostname options (DHCP_HOSTNAME and
DHCP_SEND_HOSTNAME). Add brand new vars DHCPV6_HOSTNAME and
DHCPV6_SEND_HOSTNAME to have var-property one to one mappings.

src/settings/plugins/ifcfg-rh/nms-ifcfg-rh-reader.c

@@ -1506,11 +1506,23 @@ make_ip6_setting (shvarFile *ifcfg,
 	if (strcmp (method, NM_SETTING_IP6_CONFIG_METHOD_IGNORE) == 0)
 		return NM_SETTING (s_ip6);
 
-	value = svGetValueString (ifcfg, "DHCP_HOSTNAME");
+	value = svGetValueString (ifcfg, "DHCPV6_HOSTNAME");
-	if (value && value[0])
+	/* Use DHCP_HOSTNAME as fallback if it is in FQDN format and ipv6.method is
+	 * auto or dhcp: this is required to support old ifcfg files
+	 */
+	if (!value && (   !strcmp (method, NM_SETTING_IP6_CONFIG_METHOD_AUTO)
+		       || !strcmp (method, NM_SETTING_IP6_CONFIG_METHOD_DHCP))) {
+		value = svGetValueString (ifcfg, "DHCP_HOSTNAME");
+		if (value && !strchr (value, '.'))
+			g_clear_pointer (&value, g_free);
+	}
+	if (value)
 		g_object_set (s_ip6, NM_SETTING_IP_CONFIG_DHCP_HOSTNAME, value, NULL);
 	g_free (value);
 
+	g_object_set (s_ip6, NM_SETTING_IP_CONFIG_DHCP_SEND_HOSTNAME,
+		      svGetValueBoolean (ifcfg, "DHCPV6_SEND_HOSTNAME", TRUE), NULL);
+
 	/* Read static IP addresses.
 	 * Read them even for AUTO and DHCP methods - in this case the addresses are
 	 * added to the automatic ones. Note that this is not currently supported by

src/settings/plugins/ifcfg-rh/nms-ifcfg-rh-writer.c

@@ -2442,6 +2442,23 @@ error:
 	return success;
 }
 
+static void
+write_ip6_setting_dhcp_hostname (NMSettingIPConfig *s_ip6, shvarFile *ifcfg)
+{
+	const char *hostname;
+
+	hostname = nm_setting_ip_config_get_dhcp_hostname (s_ip6);
+	svSetValueString (ifcfg, "DHCPV6_HOSTNAME", hostname);
+
+	/* Missing DHCPV6_SEND_HOSTNAME means TRUE, and we prefer not write it
+	 * explicitly in that case, because it is NM-specific variable
+	 */
+	if (nm_setting_ip_config_get_dhcp_send_hostname (s_ip6))
+		svUnsetValue (ifcfg, "DHCPV6_SEND_HOSTNAME");
+	else
+		svSetValueString (ifcfg, "DHCPV6_SEND_HOSTNAME", "no");
+}
+
 static gboolean
 write_ip6_setting (NMConnection *connection, shvarFile *ifcfg, GError **error)
 {
@@ -2469,6 +2486,8 @@ write_ip6_setting (NMConnection *connection, shvarFile *ifcfg, GError **error)
 		svUnsetValue (ifcfg, "IPV6INIT");
 		svUnsetValue (ifcfg, "IPV6_AUTOCONF");
 		svUnsetValue (ifcfg, "DHCPV6C");
+		svUnsetValue (ifcfg, "DHCPV6_HOSTNAME");
+		svUnsetValue (ifcfg, "DHCPV6_SEND_HOSTNAME");
 		svUnsetValue (ifcfg, "IPV6_DEFROUTE");
 		svUnsetValue (ifcfg, "IPV6_PEERDNS");
 		svUnsetValue (ifcfg, "IPV6_PEERROUTES");
@@ -2506,9 +2525,7 @@ write_ip6_setting (NMConnection *connection, shvarFile *ifcfg, GError **error)
 		svUnsetValue (ifcfg, "DHCPV6C");
 	}
 
-	hostname = nm_setting_ip_config_get_dhcp_hostname (s_ip6);
+	write_ip6_setting_dhcp_hostname (s_ip6, ifcfg);
-	if (hostname)
-		svSetValueString (ifcfg, "DHCP_HOSTNAME", hostname);
 
 	/* Write out IP addresses */
 	num = nm_setting_ip_config_get_num_addresses (s_ip6);
@@ -2566,6 +2583,7 @@ write_ip6_setting (NMConnection *connection, shvarFile *ifcfg, GError **error)
 		g_free (ip4_domains);
 	}
 
+
 	/* handle IPV6_DEFROUTE */
 	/* IPV6_DEFROUTE has the opposite meaning from 'never-default' */
 	if (nm_setting_ip_config_get_never_default(s_ip6))

src/settings/plugins/ifcfg-rh/tests/test-ifcfg-rh.c

@@ -3891,7 +3891,7 @@ test_read_write_wired_dhcp_send_hostname (void)
 	g_assert (s_ip6);
 	g_assert (nm_setting_ip_config_get_dhcp_send_hostname (s_ip4) == TRUE);
 	g_assert_cmpstr (nm_setting_ip_config_get_dhcp_hostname (s_ip4), ==, "svata-pulec");
-	g_assert_cmpstr (nm_setting_ip_config_get_dhcp_hostname (s_ip6), ==, "svata-pulec");
+	g_assert_null (nm_setting_ip_config_get_dhcp_hostname (s_ip6));
 
 	/* Set dhcp-send-hostname=false dhcp-hostname="kamil-patka" and write the connection. */
 	g_object_set (s_ip4, NM_SETTING_IP_CONFIG_DHCP_SEND_HOSTNAME, FALSE, NULL);