https://github.com/vortigont/esp32-dnsserverasync

Async version of ESP32's DNSServer based on AsyncUDP lib
https://github.com/vortigont/esp32-dnsserverasync

Last synced: 1 day ago
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Async version of ESP32's DNSServer based on AsyncUDP lib

• Host: GitHub
• URL: https://github.com/vortigont/esp32-dnsserverasync
• Owner: vortigont
• License: lgpl-2.1
• Created: 2022-11-18T11:17:16.000Z (almost 2 years ago)
• Default Branch: main
• Last Pushed: 2022-12-22T10:51:45.000Z (almost 2 years ago)
• Last Synced: 2024-10-11T13:36:33.472Z (25 days ago)
• Language: C++
• Size: 42 KB
• Stars: 5
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
## ESP32 Async DNSServer

This is a forked version of ESP32's [bundled](https://github.com/espressif/arduino-esp32/tree/master/libraries/DNSServer) DNSServer.

Unlike bundled version based on [WiFiUDP](https://github.com/espressif/arduino-esp32/tree/master/libraries/WiFi) lib this fork was rewritten to use [AsyncUDP](https://github.com/espressif/arduino-esp32/tree/master/libraries/AsyncUDP) lib and is more efficient on using CPU/mem resources.

A PR espressif/arduino-esp32#7482 has been raised for the upstream.

Untill(unless) it accepted this repo will be a test-lab for developing. Feel free to use this lib to replace bundled ESP32's DNSServer.

====

Bundled implementation of [DNSServer](https://github.com/espressif/arduino-esp32/tree/master/libraries/DNSServer) lib for ESP32 uses WiFiUDP which is not very efficient considering cpu/mem resources. It hooks to loop() for packet processing doing useless malloc's/free *each* run cycle, even when no requests are received.

https://github.com/espressif/arduino-esp32/blob/master/libraries/WiFi/src/WiFiUdp.cpp#L205-L221

```C++

int WiFiUDP::parsePacket(){

// skipped

  char * buf = new char[1460];

  if ((len = recvfrom(udp_server, buf, 1460, MSG_DONTWAIT, (struct sockaddr *) &si_other, (socklen_t *)&slen)) == -1){

    delete[] buf;

    return 0;

  }

```

This PR offers refactored DNSServer code based on bundled AsyncUDP lib along with other optimizations and enhansments.

- got rid of intermediate mem buffers and extra data copies in DNSServer code

- added sanity checks for mem bounds

- optimize label/packet length calculations

- removed some dynamically allocated members

- refactored "Captive Portal" example, now it will display portal detection pop-up on Android, Windows, etc...

- other code cleanup

Other known issues:

 - non A req's ain't handled properly, i.e. always reply with A type records

 - pkts with edns opt ain't handled properly, packets ignored due to additional RR's>1