Network Characterization

h1. Ubus

The [[NCd|Network Characterization daemon]] (NCd) uses "Ubus":http://wiki.openwrt.org/doc/techref/ubus (the "OpenWrt":http://www.openwrt.org micro bus architecture) to communicate with the [[NCui|Network Characterization user interface]] and with other daemons and applications. This page documents the ubus namespace of the NC, with the available procedures and several examples.

The NCd can provide information about the local node or about remote nodes. Some of the data are specific to the NCd, while others can be obtained from other local Ubus interfaces (netifd, rpcd, etc.). The NCd acts as a relay to the local Ubus, but also to remote Ubus instances. By doing so, most of the data processing is left on the NCui side, which is run on Javascript code by the user's browser. This strategy reduces the load on the network nodes, usually low-end embedded devices with limited memory and processing resources.

h2. NCd ubus namespace and procedures summary

The NCd, once registered to the Ubus daemon, provides the following procedures:

h3. Local-only node information

Each node running the NC has its unique ID that identifies it on the network. 

|_.Path                           |_.Procedure                                 |_.Signature                                      |_.Description |

|\4=. |

|ncd.local                        | [[Ubus#ncd-local-id|id]]                      | { }                                                    | Get the unique id of the local node |

 

h3. NC-specific node information

The NCd can provide the following procedures regarding other nodes in the network running the NCd:

|_.Path                            |_.Procedure                                    |_.Signature                                    |_.Description |

|\4=. |

|ncd.nodeid ²                      | [[Ubus#ncd-neighbours|neighbours]]            | { }                                                    | List all the neighbours of the node defined by _nodeid_ |

|ncd.nodeid                        | [[Ubus#ncd-nodeid-link-devices|linkdevices]]  | { "nodes": ["nodeid1", "nodeid2", ...] }               | List the devices used to link the node defined by _nodeid_ to other nodes |

|ncd.nodeid.location.name          | [[Ubus|get]]                                  | { }                                                    | Get the position (name or description) where the node defined by _nodeid_ is located |

|ncd.nodeid.location.name          | [[Ubus|get]]                                  | { "location" : "Location name or description" }        | Get the position (name or description) where the node defined by _nodeid_ is located |

|ncd.nodeid.location.coordinates   | [[Ubus|get]]                                  | { }                                                    | Get the position (latitude and longitude coordinates) where the node defined by _nodeid_ is located |

|ncd.nodeid.location.coordinates   | [[Ubus|set]]                                  | { "coordinates" : [ "lat", "lon" ] }                   | Set the position (latitude and longitude coordinates) where the node defined by _nodeid_ is located |

² Replace _nodeid_ by the node's unique id or by _local_ to request information about the local node

 

h3. Ubus relay via NC

The NCd is able to relay Ubus calls from the NCui to other Ubus instances registered remotely (like netifd, rpcd, etc.).

|_.Path                              |_.Procedure                                      |_.Signature                                      |_.Description |

|\4=. |

|ncd.nodeid.relay.daemon.path ²      | [[Ubus#ncd-remote-ubus-relay|procedure]]                              | { "daemon.path procedure signature" }           | Get the unique id of the node defined by _nodeid_ |

² Replace _nodeid_ by the node's unique id

 

See the examples below to get a clear idea of how it works.

h2. Usage examples

h3. ncd local id

Request:

 @ubus call ncd.local id { }@

Response:

 @{ "id" : "node_id" }@

 

h3. ncd local neighbours

Request:

 @ubus call ncd.local neighbours { }@

Response:

 @{ "nodes" : [ "node011", "node400" ] }@

 

h3. ncd local link devices

Request:

 @ubus call ncd.local linkdevices { "nodes" : [ "node011", "node400" ] }@

Response:

<pre>

{

  "links": [

    {

      "node011": [

        "eth0.12",

        "wlan0"

      ]

    },

    {

      "node400": [

        "wlan0"

      ]

    }

  ]

}

</pre>

 

h3. ncd local location name get

Request:

 @ubus call ncd.local.location.name get { }@

Response:

 @{ "coordinates" : [ "Narrow Street 16, Faketown" ] }@

 

h3. ncd local position coordinates get

Request:

 @ubus call ncd.local.location.coordinates get { }@

Response:

 @{ "coordinates" : [ "42.34796", "3.11036" ] }@

 

h3. ncd local position name set

Request:

 @ubus call ncd.local.location.name set { "name" : [ "Narrow Street 16, Faketown (rooftop)" }@

Response:

 @{ ] }@

 

h3. ncd local position coordinates set

Request:

 @ubus call ncd.local.position.coordinates set { "coordinates" : [ "42.34796", "3.11036" ] }@

Response:

 @{ }@

 

h3. ncd local ubus relay

Request:

 @ubus call ncd.local.relay.iwinfo devices { }@

Response:

 <pre>

{

	"devices": [

		"wlan1",

		"wlan0",

		"wlan0ap"

	]

}

 </pre>

 

ubus call iwinfo devices

h2. More examples

There is an example of the communication process between the CNAd and the CNAui via ubus [[CNAui-CNAd_communication_example|here]].