UDP Length check discards correct responses when resolving names - On Nano RP2040 Connect

[2001herne]

Arduino IDE version: 2.0.0
MbedOS core v3.3.0
Attempting to resolve host names belonging to the following:

• Raspbian linux running avahi 0.8
  • output of uname -a is: Linux piNetHub 5.10.63-v7l+ #1488 SMP Thu Nov 18 16:15:28 GMT 2021 armv7l GNU/Linux
• Arch Linux running avahi 0.8
  • output of uname -a is Linux archGaming 5.19.13-arch1-1 #1 SMP PREEMPT_DYNAMIC Tue, 04 Oct 2022 14:36:58 +0000 x86_64 GNU/Linux

Network config: All devices are connected to a WPA2 Personal network operating on 2.4 GHz

Describe the bug

When resolving a hostname, I receive a response with a length of 44. Disabling the length check results in me obtaining the correct IP address. This occurs on a Arduino Nano rp2040 connect, running Arduino MbedOS Nano. I am able to resolve this hostname using avahi-resolve-host-name on my Linux laptop.

Steps to Reproduce

1. Upload the WiFiResolvingHostnames.ino sketch
2. Attempt to resolve hostname
3. Output is Resolving '...' error
4. Modifying MDNS_Generic_Impl.h to remove the check for UDP length correctly resolves the hostname.

Expected behavior

For a valid host name to resolve to the associated IP address.

Actual behavior

The response (containing a correct IP address) is discarded by the 48 length check.

[khoih-prog]

Hi @2001herne

Thanks for spotting the bug. I'll fix and have a new release soon.

Best Regards,

[khoih-prog]

Hi @2001herne

The new MDNS_Generic v1.4.2 has just been published. Your contribution is noted in Contributions and Thanks

Best Regards,

---

Releases v1.4.2

1. Fix bug in UDP length check and in WiFi example. Check UDP Length check discards correct responses when resolving names - On Nano RP2040 Connect #13
2. Fix bug in example WiFiDiscoveringServices
3. Update Packages' Patches