v0.8.6: armhf glibc pin + Check-for-updates button (#15)

=== PR #14 follow-up: armhf build runs on Pi Bookworm/Bullseye ===

PR #14 (merged earlier) added arm-unknown-linux-gnueabihf to the
release matrix but pinned os=ubuntu-latest, which is 24.04 with GLIBC
2.39. Target armhf sysroot on 24.04 is Debian Trixie (GLIBC 2.39),
far too new for a Raspberry Pi 2/3 on Bookworm (2.36) or Bullseye
(2.31) — users would get 'GLIBC_2.39 not found' the same way the
Linux-amd64 issue #2 folks did before we pinned them to 22.04.

Fix: pin the armhf matrix entry to ubuntu-22.04, matching our other
linux-gnu targets. Binary will link against GLIBC 2.35 max, which
loads on Pi Bookworm and Bullseye. Also trimmed two trailing spaces.

Locally verified the cross-compile: rust:latest + gcc-arm-linux-
gnueabihf + proper CARGO_HOME config.toml produces a valid ARM 32-bit
ELF (2.9 MB, armhf EABI5).

=== Issue #15: 'Check for updates' button in the UI ===

New src/update_check.rs module. On the user's click (no polling):

  1. Tcp-probes github.com:443 with a 5s budget. If unreachable, we
     return Offline(reason) instead of a confusing 'update check
     failed' — distinguishes 'you're offline' from 'GitHub API
     misbehaved'.

  2. HTTPS GET api.github.com/repos/.../releases/latest via the
     tokio + rustls stack (same hand-rolled HTTP pattern as
     domain_fronter — no new crate deps). Parses tag_name, strips
     the v-prefix, loose-semver-compares to env!(CARGO_PKG_VERSION).

  3. Returns one of four UpdateCheck variants: Offline / Error /
     UpToDate / UpdateAvailable { release_url }.

New UI wiring (src/bin/ui.rs):
  - Cmd::CheckUpdate enqueue variant
  - UiState::last_update_check { InFlight, Done(result) }
  - 'Check for updates' button next to the CA buttons
  - Result displayed as a colored small-text line under the CA info:
    green 'up to date', amber 'update available v0.8.5 → v0.8.6' with
    a clickable release-page hyperlink, red for offline/error.

Verified end-to-end with a live github.com fetch (got a rate-limit
HTTP 403 from my IP because I've been hitting the API a lot, but
that's the expected Error() state — response classification was
correct). Three unit tests for is_newer() and a gated live test for
the full round-trip.

43 tests pass.

Author: therealaleph

.github/workflows/release.yml

@@ -27,8 +27,8 @@ jobs:
             os: ubuntu-22.04
             name: mhrv-rs-linux-arm64
           - target: arm-unknown-linux-gnueabihf
-            os: ubuntu-latest
-            name: mhrv-rs-raspbian-armhf  
+            os: ubuntu-22.04
+            name: mhrv-rs-raspbian-armhf
           - target: x86_64-apple-darwin
             os: macos-latest
             name: mhrv-rs-macos-amd64
@@ -82,7 +82,7 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y gcc-arm-linux-gnueabihf
           echo '[target.arm-unknown-linux-gnueabihf]' >> ~/.cargo/config.toml
-          echo 'linker = "arm-linux-gnueabihf-gcc"' >> ~/.cargo/config.toml  
+          echo 'linker = "arm-linux-gnueabihf-gcc"' >> ~/.cargo/config.toml
 
       - name: Install Windows MinGW toolchain
         if: matrix.target == 'x86_64-pc-windows-gnu'

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "mhrv-rs"
-version = "0.8.5"
+version = "0.8.6"
 edition = "2021"
 description = "Rust port of MasterHttpRelayVPN -- DPI bypass via Google Apps Script relay with domain fronting"
 license = "MIT"

Cargo.toml

@@ -90,6 +90,16 @@ struct UiState {
     last_test_msg: String,
     /// Per-SNI probe results, populated by Cmd::TestSni / TestAllSni.
     sni_probe: HashMap<String, SniProbeState>,
+    /// Most recent result of the Check-for-updates button (issue #15).
+    /// `None` = never checked this session. `Some(InFlight)` during the
+    /// probe, then the resolved outcome.
+    last_update_check: Option<UpdateProbeState>,
+}
+
+#[derive(Clone, Debug)]
+enum UpdateProbeState {
+    InFlight,
+    Done(mhrv_rs::update_check::UpdateCheck),
 }
 
 #[derive(Clone, Debug)]
@@ -118,6 +128,9 @@ enum Cmd {
         google_ip: String,
         snis: Vec<String>,
     },
+    /// Hit github.com + the Releases API and compare the running version
+    /// to the latest tag. Result is written to UiState::last_update_check.
+    CheckUpdate,
 }
 
 struct App {
@@ -766,6 +779,17 @@ impl eframe::App for App {
                 if ui.button("Check CA").clicked() {
                     let _ = self.cmd_tx.send(Cmd::CheckCaTrusted);
                 }
+
+                if ui.button("Check for updates")
+                    .on_hover_text(
+                        "Ping github.com, then ask the Releases API for the latest tag and \
+                         compare against this running version. No background polling — only \
+                         fires when you click this button."
+                    )
+                    .clicked()
+                {
+                    let _ = self.cmd_tx.send(Cmd::CheckUpdate);
+                }
             });
 
             if !last_test_msg.is_empty() {
@@ -796,6 +820,38 @@ impl eframe::App for App {
                 ));
             }
 
+            // Update-check result (issue #15): only shown after the user
+            // clicks "Check for updates". No background polling.
+            if let Some(state) = &self.shared.state.lock().unwrap().last_update_check.clone() {
+                match state {
+                    UpdateProbeState::InFlight => {
+                        ui.small(egui::RichText::new("Checking for updates…")
+                            .color(egui::Color32::GRAY));
+                    }
+                    UpdateProbeState::Done(r) => {
+                        use mhrv_rs::update_check::UpdateCheck;
+                        let (txt, color) = match r {
+                            UpdateCheck::UpToDate { .. } => (
+                                r.summary(),
+                                egui::Color32::from_rgb(80, 180, 100),
+                            ),
+                            UpdateCheck::UpdateAvailable { .. } => (
+                                r.summary(),
+                                egui::Color32::from_rgb(220, 170, 80),
+                            ),
+                            UpdateCheck::Offline(_) | UpdateCheck::Error(_) => (
+                                r.summary(),
+                                egui::Color32::from_rgb(220, 110, 110),
+                            ),
+                        };
+                        ui.small(egui::RichText::new(txt).color(color));
+                        if let UpdateCheck::UpdateAvailable { release_url, .. } = r {
+                            ui.hyperlink_to("Open release page", release_url);
+                        }
+                    }
+                }
+            }
+
             ui.separator();
             ui.label(egui::RichText::new("Recent log").strong());
             egui::ScrollArea::vertical()
@@ -1248,6 +1304,17 @@ fn background_thread(shared: Arc<Shared>, rx: Receiver<Cmd>) {
                     shared2.state.lock().unwrap().ca_trusted = Some(trusted);
                 });
             }
+            Ok(Cmd::CheckUpdate) => {
+                let shared2 = shared.clone();
+                shared2.state.lock().unwrap().last_update_check =
+                    Some(UpdateProbeState::InFlight);
+                rt.spawn(async move {
+                    let result = mhrv_rs::update_check::check().await;
+                    push_log(&shared2, &format!("[ui] update check: {}", result.summary()));
+                    shared2.state.lock().unwrap().last_update_check =
+                        Some(UpdateProbeState::Done(result));
+                });
+            }
             Err(_) => {}
         }
 

src/bin/ui.rs

@@ -11,3 +11,4 @@ pub mod rlimit;
 pub mod scan_ips;
 pub mod scan_sni;
 pub mod test_cmd;
+pub mod update_check;