`client.ip` always reports "127.0.0.1" when accessed via On Air

[ffilotto]

First Check

• I added a very descriptive title here.
• This is not a Q&A. I am sure something is wrong with NiceGUI or its documentation.
• I used the GitHub search to find a similar issue and came up empty.

Example Code

from nicegui import ui, Client

@ui.page('/')
async def index(client: Client):
    await client.connected()
    ui.label(f'Your IP is {client.ip}')

ui.run(on_air='xxx')

Description

Dear all,
first of all, great framework!

I am having a related issue to #875 that should have been solve by PR #877.

When calling "client.ip" I always only get the localhost 127.0.0.1, even if the IP should be different!

NiceGUI Version

2.3.0

Python Version

3.12.10

Browser

Firefox

Operating System

Windows

Additional Context

using on-air from the phone (android) connected to network so to get definitely a different IP.

[falkoschindler]

Hi @ffilotto,

Thanks for reporting this unexpected behavior! The reason for the IP 127.0.0.1 when accessed via On Air is as follows:

Your NiceGUI application connects to our relay server.
Your (mobile) browser also connects to our relay server.
This request is forwarded via websocket to your NiceGUI app.
Your app re-creates the original HTTP request locally which causes an IP of 127.0.0.1.

We should probably forward the browser IP to the NiceGUI app so that client.ip can report the correct value.

[ffilotto]

thank you for the explanation, at least I'll stop going crazy!

[evnchn]

Slight reminder for the implementation: The client should NEVER be able to specify the IP address they are coming from.

It would be IP Spoofing and counted as a vulnerability! May cause bypassed security measures and mess up logging and analytics.

Notably, we always ignore the client-set headers as they are not trustworthy. Cough cough Next.js 🤡