Retrieve "managed" flag of router advertisement from build-in IPv6 SLAAC support

The linux kernel has support for IPv6 SLAAC (stateless address auto-configuration) and is able to process received router advertisement messages. **BUT:** As much as I can understand, the kernel is not processing two things of the router advertisement: 1. 'M'/'O' flag to indicate the existence of a DHCPv6 server in the network *(this is stored in the inet6_dev, but never used)* 2. DNS option to pass a DNS server in the RA *(this is ignored completely)* **Is there a way to retrieve this information from the userspace?**