This PR proposes an approach to reduce the thread count of RPL.
The current RPL/Trickle stack needs about 5 threads to handle tasks
like updating the trickle timer, routing entries and the transmission of
DAOs.
This PR modifies RPL to use only one thread with a looped `msg_recv()` call.
The message is then multiplexed to the right task.
This PR removes code depending on a routing table with an entries
size > 0. Currently, all those functions and symbols are compiled into the binary,
even when there is no effective space in the routing table (as it is the
case for normal nodes in non-storing mode)
Calling ipv6_iface_set_srh_indicator with storing mode breaks the
neighbour discovery code in **ip.c:480**.
Thus, it is not possible to use `send <n> test` from node to node.
In the main function of RPL (rpl_process thread)
a mutex is used after receiving a message via msg_recv.
However, this mutex is never used in another thread and thus is rendered
obsolete.
In PR #1404 addr_str was renamed to addr_str_mode,
but at some places it was still referenced as addr_str.
When enabling debug messages, the compiler complains.
This implementation is based on RFC 6550 with addition of RFC 6554 (Source Routing Header for RPL). Both can be found under the following links:
- http://tools.ietf.org/html/rfc6550
- http://tools.ietf.org/html/rfc6554
The PR provides basic functionality for handling and forwarding packages in non-storing mode. In addition the structure of the previous implemented RPL storing mode is now revised, so that readability and modularity is increased. The following features are implemented:
- building function for a SRH and integration in common packets
- source-route build algorithm based on the structure of the DODAG
- an RPL-based interpretation of the SRH and removal at destination
- new structure for RPl-module with extracted beaconing-functionality
- leaf nodes are now supported
There are some missed goals and should be included in future updates:
- building a common routing table structure for different types of routing protocols
- routing tables are statically assigned via source code, future update should have an optional variable at build-time, which sets the size of the routing table depending on the desired functionality of a node in the network (root, node, leaf)
Instead of using differing integer types use kernel_pid_t for process
identifier. This type is introduced in a new header file to avoid
circular dependencies.
