khoih-prog/MDNS_Generic

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

2001herne opened this issue · 2 comments

2001herne commented

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 commented

Hi @2001herne

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

Best Regards,

  • 👍1
khoih-prog commented

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