Second public window address

[sdicker8]

I was very happy to find the public_network_access example - just what I need for a contest related application where contestants submit answers via their phones over WLAN. I notice that the link/address shown on the main page is a localhost address - which didn't work for me. As soon as i used the local 192.168... address (with the port) i was looking at the second page on my phone. So, i don't think get_url returns the correct url for this use case.

[edit] I do see that the localhost address works for the local machine. Maybe it's not actually 'discovering' the WLAN and it's just doing some sort of port binding. In that case, i guess it wouldn't be so easy to get what i would really want (the local router ip and port)

Great project! thanks -

[AlbertShown]

Thank you for your kind words ❤
Got it, you want shown IP to be 192.168... instead of localhost, let me check this and back to you.

[AlbertShown]

Fixed ba58cf1.

[sdicker8]

Perfect - thank you -

[sdicker8]

I think there are some subtleties here which you may want to consider. For me, the new code, discovered and used a 172.x.x.x address block, which i couldn't get to via my phone. I'm on window and i'm using WSL - ipconfig returns the following:

Windows IP Configuration

Ethernet adapter Ethernet:
   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . 

Ethernet adapter vEthernet (WSL (Hyper-V firewall)):
   Connection-specific DNS Suffix  . :
   Link-local IPv6 Address . . . . . : fe80::4626:15cd:4598:83a%43
   IPv4 Address. . . . . . . . . . . : 172.27.240.1
   Subnet Mask . . . . . . . . . . . : 255.255.240.0
   Default Gateway . . . . . . . . . :

Wireless LAN adapter Local Area Connection* 1:
   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :

Wireless LAN adapter Local Area Connection* 10:
   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :

Wireless LAN adapter Wi-Fi:
   Connection-specific DNS Suffix  . : attlocal.net
   Link-local IPv6 Address . . . . . : fe80::8616:7262:531f:790f%17
   IPv4 Address. . . . . . . . . . . : 192.168.1.74
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 192.168.1.254

The previous code, didn't tell me what ip address to use - i had to figure out that it was the 192.168.x.x address (even though i still had wsl running).

I'm thinking that you'll have to decide what to do with 10.x.x.x and 172.x.x.x address blocks if they are discovered. I'm guessing that most of the time, you would want to use a 192.168.x.x address block - but i'm not certain about that.

[AlbertShown]

Very hard to know which IP will work in every case, but here's what happens:

WebUI listens on 127.0.0.1 by default, which allows access only from the local machine. When you call webui_set_public(), WebUI listens on 0.0.0.0 instead, which means it accepts connections on all available network interfaces.

The window address is always http://localhost:1234, but since the server listens on all interfaces (0.0.0.0), you can then replace localhost with any valid IP address assigned to the machine, assuming the client can reach it.

If you're accessing WebUI from another machine, you'll need to use an IP address that is actually reachable from that machine (i.e. one it can ping or connect to).

The tricky part is that most machines have multiple interfaces, Ethernet, Wi-Fi, VPNs, virtual adapters... each with its own IP. In theory, all of them are valid to access WebUI window, but in practice, only one might be reachable from the external machine depending on the network.

The function webui_get_url() attempts to pick a usable IP, but it can only guess. It tries to avoid loopback addresses like 127.0.0.1 and picks the first active IPv4 interface it finds. However, there's no way for WebUI to know in advance which IP is reachable from the specific external machine you're using.

So even though WebUI listens on all IPs, and webui_get_url() returns an IP, only one from the perspective of the external machine will actually work.

[sdicker8]

Got it - thank you for the thorough explanation.

So webui is really not the tool to examine the network setup and 'know' anything for sure. I would guess that 192.168.x.x addresses are the most likely to be accessible by other devices and 10.x.x.x the least likely - so one could perhaps build a priority list of 'guesses'.

I can certainly make what i'm building work, but it's not clear to me what's best for the example program. Maybe some text like: Some local IP address like 192.168.x.x:[port]. Then they would immediately know that they have to examine the local network themselves.

Thanks -

[AlbertShown]

I think your suggestion is better, WebUI give a list of IPv4 that machine have, and let the user decide what to do with it.