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# SIFIS-Home Hazards
## How we fit the hazards-system in WebOfThings
---
## Hazards
- We would like to label the devices and their possible actions, so we can reason about how risky is to take an action.
- We would like to make the user aware of what could go very wrong.
- We would like to prevent at least some of their risky situations from happening.
---
## Example
- You might tell your connected oven to pre-heat
- while asleep in bed
- because you misplaced your phone.
- And the app registered a click.
- `sho:FireHazard`
---
## Setup
- WebOfThings [Thing Description](https://www.w3.org/TR/wot-thing-description/) is completely flexible, you can add semantic and functional elements [as you like](https://www.w3.org/TR/wot-thing-description/#sec-context-extensions).
- [webthings.io](https://webthings.io) has ready-to-use [Frameworks](https://webthings.io/framework/) a number of languages and platforms.
- Consuming `Things Descriptions` is fairly simple and we wrote [libsifis](https://github.com/sifis-home/libsifis-rs) on top of it and `mDNS`/`DNS-SD`.
- On top of it we built a higher-level abstraction to reason about devices (e.g. Oven, Lamps).
---
## Thing Description
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> The WoT Thing Description (TD) is a central building block in the W3C Web of Things (WoT) and can be considered as the entry point of a Thing (much like the index.html of a Web site). A TD instance has four main components: textual metadata about the Thing itself, a set of Interaction Affordances that indicate how the Thing can be used, schemas for the data exchanged with the Thing for machine-understandability, and, finally, Web links to express any formal or informal relation to other Things or documents on the Web.
> -- [wot-thing-description](https://www.w3.org/TR/wot-thing-description/#introduction)
---
## Thing Description
- Textual metadata about the Thing itself
- A set of Interaction Affordances that indicate how the Thing can be used
- Schemas for the data exchanged with the Thing for machine-understandability
- Web links to express any formal or informal relation to other Things or documents on the Web.
---
## Thing Description
### Textual metadata
- Based on [JSON-LD](https://www.w3.org/TR/json-ld11/)
- Extensible using additional Vocabularies
- e.g. using [saref](https://saref.etsi.org/) to add better semantic descriptions.
- We use this feature to add our `hazard labeling`
---
## Thing Description
### Interaction Affordance
- Mean for a device to self-describe how to interact with it
- Properties
- Actions
- Events
- This is where our hazard labels stay
---
## Thing Description
### Interaction Affordance
``` json
"properties": {
"brightness": {
"@type": "BrightnessProperty",
"description": "The level of light from 0-100",
"maximum": 100,
"minimum": 0,
"sho:Hazard": {
"@type": "sho:FireHazard",
"const": { "minimum": 70 },
"type": "integer"
},
"title": "Brightness",
"type": "integer",
"unit": "percent",
...
},
```
---
## Things Description
### Schemas for the data exchange
- Protocols
- Supports HTTPS, MQTT, and COAP
- You can extend it with custom protocols easily.
- Security scheme
- Many [SecurityScheme](https://www.w3.org/TR/wot-thing-description/#sec-security-vocabulary-definition) already available
- More can be added e.g. [ACE](https://www.w3.org/TR/wot-thing-description/#adding-security-schemes)
---
## Webthings.io
- Former [Mozilla](https://mozilla.org) project
- Now fully independent
- It implements W3C WebOfThings
- Currently a pre-standard dialect, we are helping them to update to the current standard.
- It provides frameworks to build devices.
- It provides webapps to consume devices.
- e.g. the Webthings Gateway
---
## Webthings.io
### Frameworks
- The official frameworks include a number of languages/platforms
- Node.js
- Python
- Java
- C++ / Arduino
- MicroPython
- Many other are available from the larger community
---
## Webthings.io
### Frameworks
- We are focusing on the [rust](https://github.com/sifis-home/webthing-rust) and [arduino](https://github.com/sifis-home/webthing-arduino) frameworks
- The `rust` framework works on any operating system supported by the language.
- The `arduino` framework targets bare-metal.
---
## Webthings.io / rust
- It is implemented using [actix-web](https://actix.rs) and [libmdns](https://crates.io/crates/libmdns)
- mDNS
- WebSockets
- REST
- Runs on any operating system supported by `Rust`.
---
## Webthings.io / rust
### Development
- Our fork is updated to support `WoT` instead of the `Webthings` dialect.
- We already sent upstream a number of fixes, including the minimum logic needed to support additional _ontologies_.
---
## Webthings.io / arduino
- It is implemented using C++ and [platformIO](https://platformio.org/)
- mDNS
- WebSockets
- REST
- Runs on ESP8266, ESP32
- Ethernet, and WiFi101-compatible boards.
---
## Webthings.io / arduino
### Development
- We updated the library to support additional _ontologies_ already.
- We will keep this in line with **webthings-rust** so we can use __real embedded hardware__.
- We tested its functionality already loading the firmware on a wifi-actuator acting as a Lamp.
---
# libsifis
- Consumer side of our augmented `WoT` system
- Written in `Rust`
- Based on `mdns-sd`, `reqwest` and `serde_json`
---
# libsifis
## Lower level API
- Queries mDNS for `_webthing._tcp.local.`
- Gets all the `Things Description` through `reqwest`
- Deserializes the `Things Description` using `serde_json` to rust structs.
- It is possible to use the `things()` method to iterate over the discovered devices.
---
# libsifis
## Lower level query API
- `Iterator::filter` is the main building block to query for specific things.
- On top of this we can build higher level abstractions
``` rust
let lamps = Context::new().things().filter(|td| {
td.attype.contains("Light") &&
td.attype.contains("OnOffSwitch")
});
```
---
## libsifis
### Coming Soon
- libsifis control API
- `Property::set<T>(prop: T)`
- `Property::get<T>(prop: T)`
- `Action::call<A>(args: A)`
- `Event::subscribe<F>(cb: F)`
- libsifis C bindings
---
### SIFIS-Home Hazards Ontology (SHO)
- IRI: https://purl.org/sifis/hazards
- Includes all the hazards we identified for a smart home
- Formally defines the relationship between WoT's `InteractionAffordance` and the hazards defined within SIFIS-Home
---
# Ontology Graph
<p style=font-size:20px> The class <b><span style="color: #DEAD26">Interaction Affordance</span></b> is defined within the Thing Description Ontology</p>
---
### Thing Description Example (lamp)
<div class="r-stack">
```json
{
"@context":[
"https://www.w3.org/2019/wot/td/v1",
{
"saref":"https://w3id.org/saref#",
"sho":"https://purl.org/sifis/hazards#"
}
],
"id":"urn:lamp-1234",
"title":"MyLampThing",
"@type":"saref:LightSwitch",
"description":"A lamp description containing hazards",
"securityDefinitions":{
"basic_sc":{
"scheme":"basic",
"in":"header"
}
},
"security":[
"basic_sc"
],
"properties":{
"status":{
"@type":"saref:OnOffState",
"type":"string",
"writeOnly":false,
"readOnly":true,
"forms":[
{
"href":"https://mylamp.example.com/status",
"op":"readproperty",
"contentType":"application/json"
}
],
"sho:hasHazard":[
{
"@type":"sho:LogEnergyConsumption"
}
]
},
"brightness":{
"@type":"BrightnessProperty",
"writeOnly":false,
"readOnly":false,
"description":"The level of light from 0 to 100",
"links":[
{
"href":"/properties/brightness",
"rel":"property"
}
],
"maximum":100,
"minimum":0,
"title":"Brightness",
"type":"integer",
"unit":"percent",
"forms":[
{
"href":"https://mylamp.example.com/brightness",
"op":"readproperty",
"contentType":"application/json"
}
],
"sho:hasHazard":[
{
"@type":"sho:FireHazard",
"riskScore":2
},
{
"@type":"sho:ElectricEnergyConsumption",
"riskScore":2
}
]
}
},
"actions":{
"toggle":{
"@type":"saref:ToggleCommand",
"safe":false,
"idempotent":false,
"forms":[
{
"href":"https://mylamp.example.com/toggle",
"op":"invokeaction",
"contentType":"application/json"
}
],
"sho:hasHazard":[
{
"@type":"sho:FireHazard",
"riskScore":2
},
{
"@type":"sho:ElectricEnergyConsumption",
"riskScore":2
}
]
}
},
"events":{
"overheating":{
"data":{
"type":"string",
"writeOnly":false,
"readOnly":false
},
"forms":[
{
"href":"https://mylamp.example.com/oh",
"op":"subscribeevent",
"subprotocol":"longpoll",
"contentType":"application/json"
}
]
}
}
}
```
<p class="fragment fade-in-then-out"><mark style="background-color:#DEF4C6; color:#1B512D">Looking at SHO documentation...</mark></p>
<img class="fragment fade-in-then-out" src="https://i.imgur.com/tqeARy0.png" height="400" style="margin-right:30px; margin-bottom:-150px" >
<p class="fragment fade-out"> </p>
</div>
---
# Sifis-abstraction
- Higher-level *Rust* APIs built on top of the lower level `libsifis` library
- Hazards associated to an API are automatically generated from the `SIFIS-Home Hazards Ontology` as documentation
---
# Hazards
```rust
/// Type of Hazards.
pub enum Hazards {
AirPoisoning,
AudioVideoRecordAndStore,
AudioVideoStream,
ElectricEnergyConsumption,
Explosion,
FireHazard,
LogEnergyConsumption,
...
}
```
---
# Sifis-abstraction
```rust
/// Fire hazard.
/// The execution may cause fire.
pub fn turn_on_light() {
...
}
/// Fire hazard.
/// The execution may cause fire.
///
/// Audio video stream.
/// The execution authorises the app to obtain a video stream with audio.
pub fn turn_on_oven() {
...
}
```
---
# IDE Support
- Hazards are shown as IDE's pop-ups when an API is imported
- Auto-complete functions
- Plugins are implemented by third-party developers
---
# VSCode example
<video class="fragment fade-in" data-autoplay src="https://davidblade.altervista.org/sifis/IDErecording.mov"></video>
---
# Coming Soon
- Implement the *Category* class from `SIFIS-Home Hazards Ontology` in the tool that represents hazards as documentation for higher-level APIs
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