Merge #19949

19949: tests/pkg/lwip: Add README.md r=miri64 a=miri64



Co-authored-by: Martine Lenders <m.lenders@fu-berlin.de>

tests/pkg/lwip/README.md

@@ -0,0 +1,139 @@
+# lwIP test application
+
+This application provides an example of how to use lwIP and provides test for over-the-air
+interaction between two lwIP nodes.
+
+## Testing on `native`
+
+### IPv6
+
+For IPv6 on `native` there is a test script. It requires for a TAP bridge to be set up between two
+interfaces. For that run
+
+```console
+$ sudo dist/tools/tapsetup/tapsetup
+```
+
+Then just run it with the usual test command.
+
+```
+$ make flash test
+```
+
+### IPv4
+
+For IPv4 a DHCP server is needed. If not already done for the IPv6 tests, please set up a TAP bridge
+now. Then add an IPv4 address to it, e.g.,
+
+```console
+$ sudo ip addr add 10.233.68.1/24 dev tapbr0
+```
+
+Then configure a DHCP server (e.g. [`dhcpd`](https://wiki.archlinux.org/title/Dhcpd))
+
+```
+# comment in if you need DNS and have a name server available
+# option domain-name-servers X.X.X.X X.X.X.Y;
+option subnet-mask 255.255.255.0;
+option routers 10.233.68.1;
+subnet 10.233.68.0 netmask 255.255.255.0 {
+  range 10.233.68.166 10.233.68.206;
+}
+```
+
+Then, you can use the `ip`, `udp`, and `tcp` commands to start servers and connect to them from
+clients.
+
+We use `LWIP_IPV6=0` in the following, but dual-stack support, with both `LWIP_IPV4=1` and
+`LWIP_IPV6=1` is also possible.
+
+## 6LoWPAN
+
+If `<board>` is supported, just running the following should enable 6LoWPAN.
+
+```console
+$ BOARD="<board>" make flash test
+```
+
+## Running the tests
+
+We use `native` ports below, but of course these can be interchanged with actual serial ports and
+`DEBUG_ADAPTER_ID`s to identify an actual board.
+
+#### `ip`
+
+##### Server
+
+```console
+$ LWIP_IPV4=1 LWIP_IPV6=0 PORT=tap0 make -j flash term
+[...]
+> ifconfig
+ifconfig
+Iface ET0 HWaddr: da:27:1d:a8:64:24 Link: up State: up
+        Link type: wired
+        inet addr: 10.233.68.166 mask: 255.255.255.0 gw: 10.233.68.1
+> ip server start 254
+Success: started IP server on protocol 254
+> Received IP data from [10.233.68.167]:
+00000000  AB  CD  EF
+```
+
+##### Client
+
+```console
+$ LWIP_IPV4=1 LWIP_IPV6=0 PORT=tap1 make term
+[...]
+> ip send 10.233.68.166 254 abcdef
+ip send 10.233.68.166 254 abcdef
+Success: send 3 byte over IPv6 to 10.233.68.166 (next header: 254)
+```
+
+#### `udp`
+
+`make` commands are the same as for `ip`.
+
+##### Server
+
+```console
+> udp server start 1337
+udp server start 1337
+Success: started UDP server on port 1337
+Received UDP data from 10.233.68.167:49154
+00000000  12  34  56  78  90
+```
+
+##### Client
+
+```console
+> udp send 10.233.68.166:1337 123456789
+udp send 10.233.68.166:1337 123456789
+Success: send 5 byte over UDP to 10.233.68.166:1337
+```
+
+#### `tcp`
+
+`make` commands are the same as for `ip`.
+
+##### Server
+
+```console
+> tcp server start 1337
+tcp server start 1337
+Success: started TCP server on port 1337
+TCP client 10.233.68.167:49153 connected
+Received TCP data from 10.233.68.167:49153
+00000000  76  54  32  10
+TCP connection to 10.233.68.167:49153 reset
+```
+
+##### Client
+
+```console
+> tcp connect 10.233.68.166:1337
+tcp connect 10.233.68.166:1337
+> tcp send 7654321
+tcp send 7654321
+Success: send 4 byte over TCP to server
+> tcp disconnect
+tcp disconnect
+```