nla_get_s32_default
new_ifindex = nla_get_s32_default(tb[IFLA_NEW_IFINDEX], 0);
parms.desired_ifindex = nla_get_s32_default(a[OVS_DP_ATTR_IFINDEX], 0);
parms.desired_ifindex = nla_get_s32_default(a[OVS_VPORT_ATTR_IFINDEX],
entry->ipv = nla_get_s32_default(tb[TCA_GATE_ENTRY_IPV], -1);
entry->maxoctets = nla_get_s32_default(tb[TCA_GATE_ENTRY_MAX_OCTETS],