net/ipv6: add devconfs6 array to store config option's names

* do not c/r mc_forwarding option it depends on multicast
managment socket existence and is readonly.

In addrconf_sysctl_disable->addrconf_disable_ipv6->dev_disable_change:
On addrconf_notify + NETDEV_UP if idev->cnf.mtu6 differs from dev->mtu,
sysctl mtu6 is overwritten.

So changing disable_ipv6 sysctl for some device may change mtu sysctl
for it and we need to restore disable_ipv6 first and only then mtu.
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Reviewed-by: Andrew Vagin <avagin@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

criu/net.c

@@ -109,6 +109,51 @@ static char *devconfs4[] = {
 	"drop_unicast_in_l2_multicast",
 };
 
+char *devconfs6[] = {
+	"accept_dad",
+	"accept_ra",
+	"accept_ra_defrtr",
+	"accept_ra_from_local",
+	"accept_ra_min_hop_limit",
+	"accept_ra_mtu",
+	"accept_ra_pinfo",
+	"accept_ra_rt_info_max_plen",
+	"accept_ra_rtr_pref",
+	"accept_redirects",
+	"accept_source_route",
+	"autoconf",
+	"dad_transmits",
+	"disable_ipv6",
+	"drop_unicast_in_l2_multicast",
+	"drop_unsolicited_na",
+	"force_mld_version",
+	"force_tllao",
+	"forwarding",
+	"hop_limit",
+	"ignore_routes_with_linkdown",
+	"keep_addr_on_down",
+	"max_addresses",
+	"max_desync_factor",
+	"mldv1_unsolicited_report_interval",
+	"mldv2_unsolicited_report_interval",
+	"mtu",
+	"ndisc_notify",
+	"optimistic_dad",
+	"proxy_ndp",
+	"regen_max_retry",
+	"router_probe_interval",
+	"router_solicitation_delay",
+	"router_solicitation_interval",
+	"router_solicitations",
+	"stable_secret",
+	"suppress_frag_ndisc",
+	"temp_prefered_lft",
+	"temp_valid_lft",
+	"use_oif_addrs_only",
+	"use_optimistic",
+	"use_tempaddr",
+};
+
 #define CONF_OPT_PATH "net/%s/conf/%s/%s"
 #define MAX_CONF_OPT_PATH IFNAMSIZ+50
 #define MAX_STR_CONF_LEN 200