[wpinet] Add mDNS discovery tests and fix mDNS JNI bugs (#8682)

In https://github.com/wpilibsuite/allwpilib/issues/8681 we discovered
that multicast service types need to be valid (end with _tcp or _udp),
or else errors are silently swallowed. Let's make our C++ unit test use
a valid name and also check that it works. I think if we
should/shouldn't do this is up for debate still.

I also discovered two bugs in the JNI code that lead to incorrect
results being returned
- Return array index was always 0
- Use of JLocal for the return value seems to mean that the array will
always be NULL in java

.github/workflows/bazel.yml

@@ -73,7 +73,7 @@ jobs:
 
       - name: Install apt dependencies
         if: matrix.os == 'ubuntu-24.04'
-        run: sudo apt-get update && sudo apt-get install -y libgl1-mesa-dev libx11-dev libxcursor-dev libxi-dev libxinerama-dev libxrandr-dev
+        run: sudo apt-get update && sudo apt-get install -y libgl1-mesa-dev libx11-dev libxcursor-dev libxi-dev libxinerama-dev libxrandr-dev avahi-daemon
 
       - if: matrix.os == 'ubuntu-24.04'
         uses: bazel-contrib/setup-bazel@0.15.0

.github/workflows/cmake.yml

@@ -37,6 +37,12 @@ jobs:
         if: runner.os == 'Linux'
         run: sudo apt-get update && sudo apt-get install -y libopencv-dev libopencv-java ninja-build
 
+      - name: Setup avahi-daemon
+        if: runner.os == 'Linux'
+        run: |
+          sudo service dbus start
+          sudo avahi-daemon -D
+
       - name: Install dependencies (macOS)
         if: runner.os == 'macOS'
         run: brew install opencv ninja

.github/workflows/gradle.yml

@@ -60,7 +60,11 @@ jobs:
         with:
           image: ${{ matrix.container }}
           options: -v ${{ github.workspace }}:/work -w /work -e ARTIFACTORY_PUBLISH_USERNAME -e ARTIFACTORY_PUBLISH_PASSWORD -e GITHUB_REF -e CI
-          run: ./gradlew build --build-cache -PbuildServer -PskipJavaFormat ${{ matrix.build-options }} ${{ env.EXTRA_GRADLE_ARGS }}
+          # Start avahi-daemon and build
+          run: |
+            service dbus start
+            avahi-daemon -D
+            ./gradlew build --build-cache -PbuildServer -PskipJavaFormat ${{ matrix.build-options }} ${{ env.EXTRA_GRADLE_ARGS }}
         env:
           ARTIFACTORY_PUBLISH_USERNAME: ${{ secrets.ARTIFACTORY_USERNAME }}
           ARTIFACTORY_PUBLISH_PASSWORD: ${{ secrets.ARTIFACTORY_PASSWORD }}

.github/workflows/sanitizers.yml

@@ -22,7 +22,7 @@ jobs:
             ctest-flags: "-E 'wpilibc'"
           - name: tsan
             cmake-flags: "-DCMAKE_BUILD_TYPE=Tsan"
-            ctest-env: "TSAN_OPTIONS=second_deadlock_stack=1"
+            ctest-env: "TSAN_OPTIONS=second_deadlock_stack=1:suppressions=$GITHUB_WORKSPACE/tsan_suppressions.txt"
             ctest-flags: "-E 'cscore|cameraserver'"
           - name: ubsan
             cmake-flags: "-DCMAKE_BUILD_TYPE=Ubsan"
@@ -33,7 +33,7 @@ jobs:
     container: wpilib/roborio-cross-ubuntu:2025-24.04
     steps:
       - name: Install Dependencies
-        run: sudo apt-get update && sudo apt-get install -y libopencv-dev libopencv-java clang-18 ninja-build
+        run: sudo apt-get update && sudo apt-get install -y libopencv-dev libopencv-java clang-18 ninja-build avahi-daemon
 
       - name: Install sccache
         uses: mozilla-actions/sccache-action@v0.0.9
@@ -46,6 +46,11 @@ jobs:
           SCCACHE_WEBDAV_USERNAME: ${{ secrets.ARTIFACTORY_USERNAME }}
           SCCACHE_WEBDAV_PASSWORD: ${{ secrets.ARTIFACTORY_PASSWORD }}
 
+      - name: Setup avahi-daemon
+        run: |
+          sudo service dbus start
+          sudo avahi-daemon -D
+
       - name: build
         working-directory: build
         run: cmake --build . --parallel $(nproc)