Tailscale server support

[Rodrigodd]

I am trying to get this project to work with a free account on tailscale.com, but I still haven’t been able to get it working. I am not sure where the problem is, as I couldn’t really tell from the logs. But communication with the DERP server does not appear to be working, I couldn’t find any logs showing data being received from the DERP server, although I did see data being sent and one timeout error.

I tested with a local headscale server, and it worked, but the server and the peer were on the same IP and in the same local network. In that setup, I can at least see the DERP server derp1g.tailscale.com:3478 responding to a STUN request (albeit with an “Unexpected STUN message type” message), while the test with Tailscale’s server results in the DERP server derp1h.tailscale.com:3478 timing out.

My configuration is as follows:

tailscale_auth_key: "<a reusable key generated at https://login.tailscale.com/admin/settings/keys>"
headscale_url: "https://controlplane.tailscale.com"

I’m afraid I can’t share my logs here due to sensitive information, but I can provide them privately if you’re interested.

I fixed two bugs in the code in #4 while testing the project. But I also made the two changes below when testing, but I not sure if they are suitable for upstreaming as they are. One is that /machine/map returns a JSON with PeersChanged instead of Peers, and the other is that my esp32-c3 was running out of memory so I decrease a buffer size from 64KiB to 32KiB:

commit d6540cfcc1aae6db5190b1e0f5ac62751b8b9f07
Author: Rodrigo Batista de Moraes <rodrigobatsmoraes@hotmail.com>
Date:   Sat Dec 13 23:47:27 2025 -0300

    fix: search for PeersChanged

diff --git a/components/tailscale/map_response_parser.cpp b/components/tailscale/map_response_parser.cpp
index e2f5a17..3cee349 100644
--- a/components/tailscale/map_response_parser.cpp
+++ b/components/tailscale/map_response_parser.cpp
@@ -304,7 +304,7 @@ bool parse_map_response_streaming(const char *json, size_t len, MapResponseData
   }
 
   // ========== Extract Peers Array ==========
-  const char* peers_start = find_str(json, end, "\"Peers\":[");
+  const char* peers_start = find_str(json, end, "\"PeersChanged\":[");
   if (peers_start) {
     ESP_LOGI(TAG, "Found Peers section");
 
@@ -562,7 +562,7 @@ bool parse_map_static(const char *json, size_t len, StaticMapResponse &out,
   }
 
   // ========== Extract Peers (with optional filtering) ==========
-  const char* peers_start = find_str(json, end, "\"Peers\":[");
+  const char* peers_start = find_str(json, end, "\"PeersChanged\":[");
   if (peers_start) {
     if (allowed_peers && !allowed_peers->empty()) {
       ESP_LOGI(TAG, "Found Peers section (filtering enabled, up to %d matches)", MAX_PEERS);

commit c62dd686f46db4e7011ca04f85324a9f640443cf
Author: Rodrigo Batista de Moraes <rodrigobatsmoraes@hotmail.com>
Date:   Sat Dec 13 23:46:48 2025 -0300

    fix: decrease buffer size for Http2Session

diff --git a/components/tailscale/http2_session.h b/components/tailscale/http2_session.h
index 287b805..5b76752 100644
--- a/components/tailscale/http2_session.h
+++ b/components/tailscale/http2_session.h
@@ -60,7 +60,7 @@ class Http2Session {
 
   // Streaming JSON parser to extract only Node field (discards 56KB DERPMap)
   JsonStreamParser json_parser_;
-  static constexpr size_t kFilteredBufferSize = 65536;  // 64KB for full MapResponse (Node + Peers + DERPMap)
+  static constexpr size_t kFilteredBufferSize = 32768;  // 32KB for full MapResponse (Node + Peers + DERPMap)
   char filtered_json_buffer_[kFilteredBufferSize];
   bool parsing_json_{false};
   bool json_complete_{false};

[gbertsch]

Any luck @Rodrigodd ? Does this still not work with tailscale.com?

[Rodrigodd]

@gbertsch No, I didn't try again since I post this. But I did try https://github.com/CamM2325/microlink, and I got further with it, but I still could not get it to work, mainly due to problems with the limited memory on the esp32-c3. I still need to try again with a esp32-s3. The microlink repo sound more promising, I will probably not try this repo again.