Who provides IP addresses in a truly ad-hoc, truly "peer only" mesh network ?
Nobody, as far as I know.
You may want to have a look at AHCP[1], however. When configured for IPv6 only, it gets configuration information (such as the IPv6 prefix and the name server address) from central servers, but behaves in a completely stateless manner -- there is no information stored in the servers.
In IPv4, however, it uses leases, just like DHCP, so it needs to store state in the servers.
Please do point me to any writings or information related to this.
Search for draft-bernardos-manet-autoconf-survey.
Juliusz