Re: [lwip-users] LwIP - 2 netifs and VPN

[Andrea Marangon]

Hi Sergio,
I try to describe my scenario:

I'm using lwip on the ESP8266 wifi module.

This module is connected to my board and communicates via PPPoS (the PPP 
client is the Wifi module) then there is a first network interface 
("pp") and its addresses are assigned by the server (my board).

PPP --> IP: 10.11.12.12

The second network interface is the wifi ("wn") and its addresses are 
assigned when it connects to a router in a local network.

WIFI --> IP: 192.168.1.133, MASK: 255.255.255.0, GW: 192.168.1.1

Now I need to exchange TCP and UDP packets from Wifi to my board and 
vice versa.

To do this I used the raw API.
I created two TCP PCB: one connected to 10.11.12.12 (pp) and the other 
binded with the address 192.168.1.133 (wn) in listen mode.

When a TCP connection request arrives at the address 192.168.1.133 (and 
specific port), the connection is accepted and I can send and receive 
packets between the two pcb using the respective received callbacks.

Similarly I do for the UDP connection.

This system works if the connecting host is in the same subnet.
I tried to connect via VPN (IP:192.168.100.83, MASK: 255.255.255.0, GW: 
192.168.100.1) but I can only receive UDP packets.

I could see that the TCP connection is not accepted because the wrong 
network interface is returned in ip4_route ()

Is this behavior normal or I'm wrong with some configuration options?

Analyzing the code I think I have to act on the macro 
LWIP_HOOK_IP4_ROUTE_SRC... is this the right way?


Thanks

Andrea Marangon






------ Messaggio originale ------
Da: "Sergio R. Caprile" <address@hidden>
A: address@hidden
Inviato: 11/07/2018 21:18:37
Oggetto: Re: [lwip-users] LwIP - 2 netifs and VPN

> I fail to see what you are doing and what you are trying to do.
> Do you mind putting names and addresses and describe what you do and 
> the
> expected behaviour ?
>
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