DHTPK human documentation.

[NamsooCho]

Description of DHT PK packets

Onion client works using onion, tcp_relay and dht to manage exchanging node's PK and connections to friends.

Tox client calls onion client's main loop, this loop do

• check if onion is connected to tox networks
  • last time of received packet is past 75 seconds => onion is not connected.
  • there is no path entry in path list => onion is not connected.
• if onion is not connected to Tox networks then
  • populate path list from tcp_relay module
• if onion is connected to tox networks then
  • do things below for every friend
    • check if friend is online
    • if friend is online then
      • skip this friend
    • if friend is not online then
      • send AnnounceRequest to all of friend's client list
        • if some node of friend's client list is timed out then
          • send AnnounceRequest to random node of path list
    • there are two timer interval, dhtpk for dht and dhtpk for onion
    • if dhtpk interval timer for dht expires then
      • create ONION_DATA_DHTPK payload
      • get node list from close list of freind which is in dht
      • create CRYPTO_PACKET_DHTPK packet
      • send packet to all node
    • if dhtpk interval timer for onion expires then
      • create ONION_DATA_DHTPK payload
      • get destination nodes from friend's client list
      • for each destination node do
        • create OnionDataRequest packet
        • if destination address is UDP then
          • send packet using UDP
        • if destination address is TCP then
          • send packet using TCP client's secure connection
• if 3 seconds have passed since booting of onion then
  • get random path from onion's path list
    • create OnionAnnounce packet using onion's PK
    • send packet using TCP or UDP
  • get random path from onion friend's path list
    • create OnionAnnounce packet using friend's PK
    • send packet using TCP or UDP

When dhtpk packet is received then

• decrypt
• if PK differs from current PK then
  • delete DHT friend
  • create DHT friend with new PK
  • make a new friend connection
  • set onion friend's dht PK
• unpack received packet then for each nodes
  • if node is UDP then
    • send NodesRequest
  • if node is TCP then
    • add node to tcp relay list and friend's tcp relay list

When AnnounceResponse packet is received then

• decrypt packet
• init path's timeout variables
• copy nodes to path_nodes list
• add nodes to list to be announced or friend's client list
• init nodes added
• for each node of payload do
  • if node's IP is within LAN then skip
  • if destinaiton node is timed out then skip
  • if node is already in list to be announced or friend's client list then skip
  • send AnnounceRequest to node

When OnionDataResponse packet is received from onion then

• decrypt packet
• process packet using handler for dhtpk announce

When packet is received from TCP client then

• if packet is AnnounceResponse then
  • process packet using handler for AnnounceResponse
• if packet is OnionDataResponse then
  • process packet using handler for OnionDataResponse