Re: [PATCH] ifcfg-rh: Enable IPv6 by default and make IPv4 optional

[Dan Williams <dcbw redhat com>]

On Sun, 2011-08-07 at 18:39 +0200, Tore Anderson wrote:
> This patch changes the default values of the IPV6INIT and
> IPV4_FAILURE_FATAL ifcfg variables, which allows a Fedora/Red Hat host
> to, with no manual configuration necessary, successfully connect to an
> IPv6-only network, as well as learn DHCPv6-provided information (such as
> DNS servers and IP addresses) when connecting to a dual-stacked network.
> 
> It also changes the semantics of an ifcfg file that has only IPv6 layer
> 3 configuration settings (no IPv4) slightly, in this case DHCPv4 will be
> performed. Before, this configuration would lead to IPv4 being disabled.
> In order for IPv4 to be disabled when IPv6 is explicitly enabled, the
> BOOTPROTO variable must be set to NONE.

Is the change in behavior of IPv4 consistent with what ifup does?  Or
can you explain a bit more the reason for this change?  The rest of the
patch is great, and now is the time to flip IPv6 on by default for
real :)

Dan

> diff --git a/src/settings/plugins/ifcfg-rh/reader.c b/src/settings/plugins/ifcfg-rh/reader.c
> index cdf5889..9ff5af2 100644
> --- a/src/settings/plugins/ifcfg-rh/reader.c
> +++ b/src/settings/plugins/ifcfg-rh/reader.c
> @@ -1204,9 +1204,8 @@ make_ip4_setting (shvarFile *ifcfg,
>  		char *tmp_ip4_1, *tmp_prefix_1, *tmp_netmask_1;
>  		char *tmp_ip4_2, *tmp_prefix_2, *tmp_netmask_2;
>  
> -		/* If there is no BOOTPROTO, no IPADDR, no PREFIX, no NETMASK, but
> -		 * valid IPv6 configuration, assume that IPv4 is disabled.  Otherwise,
> -		 * if there is no IPv6 configuration, assume DHCP is to be used.
> +		/* If there is no BOOTPROTO, no IPADDR, no PREFIX, no NETMASK, assume
> +		 * that DHCP is to be used.
>  		 * Happens with minimal ifcfg files like the following that anaconda
>  		 * sometimes used to write out:
>  		 *
> @@ -1230,11 +1229,7 @@ make_ip4_setting (shvarFile *ifcfg,
>  		    && !tmp_ip4_0 && !tmp_prefix_0 && !tmp_netmask_0
>  		    && !tmp_ip4_1 && !tmp_prefix_1 && !tmp_netmask_1
>  		    && !tmp_ip4_2 && !tmp_prefix_2 && !tmp_netmask_2) {
> -			if (valid_ip6_config)
> -				/* Nope, no IPv4 */
> -				method = NM_SETTING_IP4_CONFIG_METHOD_DISABLED;
> -			else
> -				method = NM_SETTING_IP4_CONFIG_METHOD_AUTO;
> +			method = NM_SETTING_IP4_CONFIG_METHOD_AUTO;
>  		}
>  		g_free (tmp_ip4);
>  		g_free (tmp_prefix);
> @@ -1255,7 +1250,7 @@ make_ip4_setting (shvarFile *ifcfg,
>  	              NM_SETTING_IP4_CONFIG_IGNORE_AUTO_DNS, !svTrueValue (ifcfg, "PEERDNS", TRUE),
>  	              NM_SETTING_IP4_CONFIG_IGNORE_AUTO_ROUTES, !svTrueValue (ifcfg, "PEERROUTES", TRUE),
>  	              NM_SETTING_IP4_CONFIG_NEVER_DEFAULT, never_default,
> -	              NM_SETTING_IP4_CONFIG_MAY_FAIL, !svTrueValue (ifcfg, "IPV4_FAILURE_FATAL", TRUE),
> +	              NM_SETTING_IP4_CONFIG_MAY_FAIL, !svTrueValue (ifcfg, "IPV4_FAILURE_FATAL", FALSE),
>  	              NULL);
>  
>  	if (strcmp (method, NM_SETTING_IP4_CONFIG_METHOD_DISABLED) == 0)
> @@ -1476,11 +1471,11 @@ make_ip6_setting (shvarFile *ifcfg,
>  	/* Find out method property */
>  	/* Is IPV6 enabled? Set method to "ignored", when not enabled */
>  	str_value = svGetValue (ifcfg, "IPV6INIT", FALSE);
> -	ipv6init = svTrueValue (ifcfg, "IPV6INIT", FALSE);
> +	ipv6init = svTrueValue (ifcfg, "IPV6INIT", TRUE);
>  	if (!str_value) {
>  		network_ifcfg = svNewFile (network_file);
>  		if (network_ifcfg) {
> -			ipv6init = svTrueValue (network_ifcfg, "IPV6INIT", FALSE);
> +			ipv6init = svTrueValue (network_ifcfg, "IPV6INIT", TRUE);
>  			svCloseFile (network_ifcfg);
>  		}
>  	}
>