diff --git a/.github/workflows/ci-linux.yml b/.github/workflows/ci-linux.yml
new file mode 100644
index 00000000..62cd52fd
--- /dev/null
+++ b/.github/workflows/ci-linux.yml
@@ -0,0 +1,50 @@
+name: CI
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    strategy:
+      matrix:
+        compiler: [gcc, clang]
+    env:
+      CC: ${{ matrix.compiler }}
+      LSAN_OPTIONS: verbosity=1:log_threads=1
+      WGET_PATH: http://download.savannah.nongnu.org/releases/lwip
+      CONTRIB: contrib-2.1.0
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Install deps
+      run: |
+        sudo apt-get install check ninja-build doxygen
+        wget --no-verbose ${WGET_PATH}/${CONTRIB}.zip
+        unzip -oq ${CONTRIB}.zip
+        patch -s -p0 < test/${CONTRIB}.patch
+
+    - name: Build unit tests with make
+      run: LWIPDIR=../../../../src make -C ${CONTRIB}/ports/unix/check
+    - name: Run unit tests
+      run: LWIPDIR=../../../../src make -C ${CONTRIB}/ports/unix/check check
+
+    - name: Run cmake
+      run: mkdir build && cd build && cmake .. -G Ninja
+    - name: Build with cmake
+      run: cd build && cmake --build .
+    - name: Build docs with cmake
+      run: cd build && cmake --build . --target lwipdocs
+
+    - name: Validate combinations of options
+      run: |
+        cp ${CONTRIB}/examples/example_app/lwipcfg.h.example ${CONTRIB}/examples/example_app/lwipcfg.h
+        cd ${CONTRIB}/ports/unix/example_app
+        export CFLAGS="-DESP_LWIP=LWIP_NETCONN_FULLDUPLEX"
+        export LWIPDIR=../../../../src/
+        chmod +x iteropts.sh && ./iteropts.sh
+
+    - name: Build and run unit tests with cmake
+      run: |
+        cd ${CONTRIB}/ports/unix/check
+        mkdir build && cd build && cmake -DLWIP_DIR=`pwd`/../../../../.. .. -G Ninja
+        cmake --build . && ./lwip_unittests
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
new file mode 100644
index 00000000..88866e95
--- /dev/null
+++ b/.gitlab-ci.yml
@@ -0,0 +1,98 @@
+stages:
+  - host_test
+  - deploy
+
+image: ${CI_DOCKER_REGISTRY}/esp-env-v5.0:2
+
+variables:
+# tag in lwip-contrib repo, which supports our esp-lwip branch (and it's cherry-picked commits from release branches)
+  LWIP_CONTRIB_TAG: STABLE-2_1_0_RELEASE
+# test timeout is seconds
+  TEST_TIMEOUT: 200
+  CONTRIB: contrib-2.1.0
+  CMAKE_SH: cmake-3.22.3-linux-x86_64.sh
+
+before_script:
+  # Use CI Tools
+  - curl -sSL ${CIT_LOADER_URL} | sh
+  - source citools/import_functions
+
+.get_cmake: &get_cmake |
+  wget -q https://github.com/Kitware/CMake/releases/download/v3.22.3/${CMAKE_SH}
+  mkdir -p /opt/cmake && sh ${CMAKE_SH} --prefix=/opt/cmake --skip-license
+  export PATH=/opt/cmake/bin:$PATH
+
+.get_contrib: &get_contrib |
+  mkdir -p ~/.ssh
+  chmod 700 ~/.ssh
+  echo -n $GITLAB_KEY > ~/.ssh/id_rsa_base64
+  base64 --decode --ignore-garbage ~/.ssh/id_rsa_base64 > ~/.ssh/id_rsa
+  chmod 600 ~/.ssh/id_rsa
+  echo -e "Host ${GITLAB_HOSTNAME}\n\tStrictHostKeyChecking no\n" >> ~/.ssh/config
+  git clone "${LWIP_CONTRIB_MIRROR}" ${CONTRIB} && cd ${CONTRIB} && git checkout tags/${LWIP_CONTRIB_TAG}
+  cd .. && sed -i $'s/\r$//' test/contrib-2.1.0.patch && patch -s -p0 < test/${CONTRIB}.patch
+
+run_unittests:
+  stage: host_test
+  tags:
+    - host_test
+  dependencies: []
+  script:
+    - *get_contrib
+    - LWIPDIR=../../../../src make -C ${CONTRIB}/ports/unix/check check
+
+run_unittests_cmake:
+  stage: host_test
+  tags:
+    - host_test
+  script:
+    - *get_contrib
+    - *get_cmake
+    - cd ${CONTRIB}/ports/unix/check
+    - mkdir build && cd build && cmake -DLWIP_DIR=`pwd`/../../../../.. .. -G Ninja
+    - cmake --build . && ./lwip_unittests
+
+build_all:
+  stage: host_test
+  tags:
+    - host_test
+  script:
+    - *get_cmake
+    - mkdir build && cd build && cmake .. -G Ninja
+    - cmake --build .
+    - cmake --build . --target lwipdocs
+
+validate_opts:
+  stage: host_test
+  tags:
+    - host_test
+  script:
+    - *get_contrib
+    - cp ${CONTRIB}/examples/example_app/lwipcfg.h.example ${CONTRIB}/examples/example_app/lwipcfg.h
+    - cd ${CONTRIB}/ports/unix/example_app
+    - export CFLAGS="-DESP_LWIP=LWIP_NETCONN_FULLDUPLEX"
+    - export LWIPDIR=../../../../src/
+    - chmod +x iteropts.sh && ./iteropts.sh
+
+
+.add_gh_key_remote: &add_gh_key_remote |
+  command -v ssh-agent >/dev/null || exit 1
+  eval $(ssh-agent -s)
+  printf '%s\n' "${GH_PUSH_KEY}" | tr -d '\r' | ssh-add - > /dev/null
+  mkdir -p ~/.ssh && chmod 700 ~/.ssh
+  [[ -f /.dockerenv ]] && echo -e "Host *\n\tStrictHostKeyChecking no\n\n" > ~/.ssh/config || ssh-keyscan -t rsa github.com >> ~/.ssh/known_hosts
+  git remote remove github || true
+  git remote add github ${GH_PUSH_REPO}
+
+push_master_to_github:
+  stage: deploy
+  only:
+    - 2.1.2-esp
+  when: on_success
+  variables:
+    GIT_STRATEGY: clone
+  script:
+    - *add_gh_key_remote
+    - "[ -n \"${CI_COMMIT_TAG:-}\" ] && git push github ${CI_COMMIT_TAG}"
+    - "[ -z \"${CI_COMMIT_TAG:-}\" ] && git push github ${CI_COMMIT_SHA}:refs/heads/${CI_COMMIT_REF_NAME}"
+
diff --git a/test/contrib-2.1.0.patch b/test/contrib-2.1.0.patch
new file mode 100644
index 00000000..e133ede1
--- /dev/null
+++ b/test/contrib-2.1.0.patch
@@ -0,0 +1,181 @@
+diff -ruN contrib-2.1.0/examples/example_app/test_configs/opt_no_tcp_dualstack.h contrib-2.1.0-P/examples/example_app/test_configs/opt_no_tcp_dualstack.h
+--- contrib-2.1.0/examples/example_app/test_configs/opt_no_tcp_dualstack.h	2018-09-12 22:16:02.000000000 +0200
++++ contrib-2.1.0-P/examples/example_app/test_configs/opt_no_tcp_dualstack.h	2022-03-19 15:07:57.455415829 +0100
+@@ -1,4 +1,4 @@
+ #include "test_configs/opt_dualstack.h"
+ 
+ #undef LWIP_TCP
+-#define LWIP_TCP 0
+\ No newline at end of file
++#define LWIP_TCP 0
+diff -ruN contrib-2.1.0/examples/example_app/test_configs/opt_no_tcp_ipv4only.h contrib-2.1.0-P/examples/example_app/test_configs/opt_no_tcp_ipv4only.h
+--- contrib-2.1.0/examples/example_app/test_configs/opt_no_tcp_ipv4only.h	2018-09-12 22:16:02.000000000 +0200
++++ contrib-2.1.0-P/examples/example_app/test_configs/opt_no_tcp_ipv4only.h	2022-03-19 15:08:27.446964821 +0100
+@@ -1,4 +1,4 @@
+ #include "test_configs/opt_ipv4only.h"
+ 
+ #undef LWIP_TCP
+-#define LWIP_TCP 0
+\ No newline at end of file
++#define LWIP_TCP 0
+diff -ruN contrib-2.1.0/examples/example_app/test_configs/opt_no_tcp_ipv6only.h contrib-2.1.0-P/examples/example_app/test_configs/opt_no_tcp_ipv6only.h
+--- contrib-2.1.0/examples/example_app/test_configs/opt_no_tcp_ipv6only.h	2018-09-12 22:16:02.000000000 +0200
++++ contrib-2.1.0-P/examples/example_app/test_configs/opt_no_tcp_ipv6only.h	2022-03-19 15:08:36.622826844 +0100
+@@ -1,4 +1,4 @@
+ #include "test_configs/opt_ipv6only.h"
+ 
+ #undef LWIP_TCP
+-#define LWIP_TCP 0
+\ No newline at end of file
++#define LWIP_TCP 0
+diff -ruN contrib-2.1.0/examples/example_app/test_configs/opt_no_udp_dualstack.h contrib-2.1.0-P/examples/example_app/test_configs/opt_no_udp_dualstack.h
+--- contrib-2.1.0/examples/example_app/test_configs/opt_no_udp_dualstack.h	2018-09-12 22:16:02.000000000 +0200
++++ contrib-2.1.0-P/examples/example_app/test_configs/opt_no_udp_dualstack.h	2022-03-19 15:08:43.974716296 +0100
+@@ -1,4 +1,4 @@
+ #include "test_configs/opt_dualstack.h"
+ 
+ #undef LWIP_UDP
+-#define LWIP_UDP 0
+\ No newline at end of file
++#define LWIP_UDP 0
+diff -ruN contrib-2.1.0/examples/example_app/test_configs/opt_no_udp_ipv4only.h contrib-2.1.0-P/examples/example_app/test_configs/opt_no_udp_ipv4only.h
+--- contrib-2.1.0/examples/example_app/test_configs/opt_no_udp_ipv4only.h	2018-09-12 22:16:02.000000000 +0200
++++ contrib-2.1.0-P/examples/example_app/test_configs/opt_no_udp_ipv4only.h	2022-03-19 15:08:48.590646888 +0100
+@@ -1,4 +1,4 @@
+ #include "test_configs/opt_ipv4only.h"
+ 
+ #undef LWIP_UDP
+-#define LWIP_UDP 0
+\ No newline at end of file
++#define LWIP_UDP 0
+diff -ruN contrib-2.1.0/examples/example_app/test_configs/opt_no_udp_ipv6only.h contrib-2.1.0-P/examples/example_app/test_configs/opt_no_udp_ipv6only.h
+--- contrib-2.1.0/examples/example_app/test_configs/opt_no_udp_ipv6only.h	2018-09-12 22:16:02.000000000 +0200
++++ contrib-2.1.0-P/examples/example_app/test_configs/opt_no_udp_ipv6only.h	2022-03-19 15:08:52.490588248 +0100
+@@ -1,4 +1,4 @@
+ #include "test_configs/opt_ipv6only.h"
+ 
+ #undef LWIP_UDP
+-#define LWIP_UDP 0
+\ No newline at end of file
++#define LWIP_UDP 0
+diff -ruN contrib-2.1.0/ports/CMakeCommon.cmake contrib-2.1.0-P/ports/CMakeCommon.cmake
+--- contrib-2.1.0/ports/CMakeCommon.cmake	2018-09-04 22:54:08.000000000 +0200
++++ contrib-2.1.0-P/ports/CMakeCommon.cmake	2022-03-19 15:03:40.651279436 +0100
+@@ -73,7 +73,6 @@
+                 -fsanitize=undefined
+                 -fno-sanitize=alignment
+                 -fstack-protector
+-                -fstack-check
+             )
+             set(LWIP_SANITIZER_LIBS asan ubsan)
+         endif()
+diff -ruN contrib-2.1.0/ports/unix/check/CMakeLists.txt contrib-2.1.0-P/ports/unix/check/CMakeLists.txt
+--- contrib-2.1.0/ports/unix/check/CMakeLists.txt	2018-09-04 22:54:08.000000000 +0200
++++ contrib-2.1.0-P/ports/unix/check/CMakeLists.txt	2022-03-19 15:03:40.651279436 +0100
+@@ -7,14 +7,12 @@
+ endif()
+ 
+ set(LWIP_CONTRIB_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../../..)
+-set(LWIP_DIR         ${CMAKE_CURRENT_SOURCE_DIR}/../../../../lwip)
+ 
+ set(LWIP_USE_SANITIZERS true)
+ include(${LWIP_CONTRIB_DIR}/ports/CMakeCommon.cmake)
+ 
+ if(CMAKE_C_COMPILER_ID STREQUAL Clang)
+     # check.h causes 'error: token pasting of ',' and __VA_ARGS__ is a GNU extension' with clang 9.0.0
+-    list(LWIP_COMPILER_FLAGS APPEND -Wno-gnu-zero-variadic-macro-arguments)
+ endif()
+ 
+ set (LWIP_DEFINITIONS -DLWIP_DEBUG -DLWIP_NOASSERT_ON_ERROR)
+diff -ruN contrib-2.1.0/ports/unix/example_app/iteropts.sh contrib-2.1.0-P/ports/unix/example_app/iteropts.sh
+--- contrib-2.1.0/ports/unix/example_app/iteropts.sh	2018-09-12 22:16:02.000000000 +0200
++++ contrib-2.1.0-P/ports/unix/example_app/iteropts.sh	2022-03-19 15:03:40.651279436 +0100
+@@ -1,24 +1,34 @@
+-#!/bin/bash
+-
+-LOGFILE=iteropts.log
+-EXAPPDIR=../../../examples/example_app
+-
+-pushd `dirname "$0"`
+-pwd
+-echo Starting Iteropts run >> $LOGFILE
+-for f in $EXAPPDIR/test_configs/*.h
+-do
+-    echo Cleaning...
+-    make clean
+-    BUILDLOG=$(basename "$f" ".h").log
+-    echo testing $f
+-    echo testing $f >> $LOGFILE
+-    rm $EXAPPDIR/lwipopts_test.h
+-    # cat the file to update its timestamp
+-    cat $f > $EXAPPDIR/lwipopts_test.h
+-    make TESTFLAGS=-DLWIP_OPTTEST_FILE -j 8 &> $BUILDLOG 2>&1 || echo file $f failed >> $LOGFILE
+-    echo test $f done >> $LOGFILE
+-done
+-echo done, cleaning
+-make clean
+-popd
++#!/bin/bash
++
++LOGFILE=iteropts.log
++EXAPPDIR=../../../examples/example_app
++RETVAL=0
++
++pushd `dirname "$0"`
++pwd
++echo Starting Iteropts run >> $LOGFILE
++for f in $EXAPPDIR/test_configs/*.h
++do
++    echo Cleaning...
++    make clean > /dev/null
++    BUILDLOG=$(basename "$f" ".h").log
++    echo testing $f
++    echo testing $f >> $LOGFILE
++    rm -f $EXAPPDIR/lwipopts_test.h
++    # cat the file to update its timestamp
++    cat $f > $EXAPPDIR/lwipopts_test.h
++    make TESTFLAGS="-DLWIP_OPTTEST_FILE -Wno-documentation" -j 4 1> $BUILDLOG 2>&1
++    ERR=$?
++    if [ $ERR != 0 ]; then
++        cat $BUILDLOG
++        echo file $f failed with $ERR >> $LOGFILE
++        echo ++++++++ $f FAILED +++++++
++        RETVAL=1
++    fi
++    echo test $f done >> $LOGFILE
++done
++echo done, cleaning
++make clean > /dev/null
++popd
++echo Exit value: $RETVAL
++exit $RETVAL
+diff -ruN contrib-2.1.0/ports/unix/port/include/arch/sys_arch.h contrib-2.1.0-P/ports/unix/port/include/arch/sys_arch.h
+--- contrib-2.1.0/ports/unix/port/include/arch/sys_arch.h	2018-07-12 21:24:16.000000000 +0200
++++ contrib-2.1.0-P/ports/unix/port/include/arch/sys_arch.h	2022-03-19 15:05:59.193194629 +0100
+@@ -59,5 +59,8 @@
+ struct sys_thread;
+ typedef struct sys_thread * sys_thread_t;
+ 
++#define LWIP_EXAMPLE_APP_ABORT() lwip_unix_keypressed()
++int lwip_unix_keypressed(void);
++
+ #endif /* LWIP_ARCH_SYS_ARCH_H */
+ 
+diff -ruN contrib-2.1.0/ports/unix/port/sys_arch.c contrib-2.1.0-P/ports/unix/port/sys_arch.c
+--- contrib-2.1.0/ports/unix/port/sys_arch.c	2018-09-04 22:02:58.000000000 +0200
++++ contrib-2.1.0-P/ports/unix/port/sys_arch.c	2022-03-19 15:07:13.416078142 +0100
+@@ -717,3 +717,14 @@
+     }
+ }
+ #endif /* SYS_LIGHTWEIGHT_PROT */
++
++/* get keyboard state to terminate the debug app by using select */
++int
++lwip_unix_keypressed(void)
++{
++  struct timeval tv = { 0L, 0L };
++  fd_set fds;
++  FD_ZERO(&fds);
++  FD_SET(0, &fds);
++  return select(1, &fds, NULL, NULL, &tv);
++}