Add MQTT device through RNDIS example

.github/workflows/test.yml

@@ -557,26 +557,26 @@ jobs:
       - if: ${{ env.GO == 1 }}
         run: make -C examples/${{ matrix.example.path }} build
 
-#  mqtt_dashboard_examples:
-#    runs-on: ubuntu-latest
-#    strategy:
-#      fail-fast: false
-#      matrix:
-#        example:
-#          - path: 
-#    name: ${{ matrix.example.path }}
-#    env:
-#      GO: 0
-#    steps:
-#      - uses: actions/checkout@v3
-#        with: { fetch-depth: 2 }
-#      - run: |
-#          if ./test/match_changed_files.sh '^src|examples/mqtt-dashboard/device|^examples/${{ matrix.example.path }}'; then
-#            echo GO=1 >> $GITHUB_ENV
-#            sudo apt -y update && sudo apt -y install gcc-arm-none-eabi
-#          fi
-#      - if: ${{ env.GO == 1 }}
-#        run: make -C examples/${{ matrix.example.path }} build
+  mqtt_dashboard_examples:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        example:
+          - path: rp2040/pico-rndis-device
+    name: ${{ matrix.example.path }}
+    env:
+      GO: 0
+    steps:
+      - uses: actions/checkout@v3
+        with: { fetch-depth: 2 }
+      - run: |
+          if ./test/match_changed_files.sh '^src|examples/mqtt-dashboard/device|^examples/${{ matrix.example.path }}'; then
+            echo GO=1 >> $GITHUB_ENV
+            sudo apt -y update && sudo apt -y install gcc-arm-none-eabi
+          fi
+      - if: ${{ env.GO == 1 }}
+        run: make -C examples/${{ matrix.example.path }} build
 
   dual_examples:
     runs-on: ubuntu-latest

examples/rp2040/pico-rndis-device/CMakeLists.txt

@@ -0,0 +1,28 @@
+cmake_minimum_required(VERSION 3.13)
+include(pico-sdk/pico_sdk_init.cmake)
+
+project(firmware)
+pico_sdk_init()
+
+add_executable(firmware
+  main.c
+  usb_descriptors.c
+  mongoose.c
+  net.c
+  pico-sdk/lib/tinyusb/lib/networking/rndis_reports.c)
+
+target_include_directories(firmware PUBLIC
+  .
+  pico-sdk/lib/tinyusb/lib/networking)
+
+target_link_libraries(firmware pico_stdlib hardware_spi tinyusb_device)
+pico_add_extra_outputs(firmware)     # create map/bin/hex file etc.
+
+pico_enable_stdio_usb(firmware 0)    # Route stdio
+pico_enable_stdio_uart(firmware 1)   # to the UART
+
+# Mongoose build flags
+add_definitions(-DMG_ENABLE_TCPIP=1)
+add_definitions(-DMG_ENABLE_FILE=0)
+
+# Example build options

examples/rp2040/pico-rndis-device/Makefile

@@ -0,0 +1,20 @@
+RM = rm -rf
+MKBUILD = test -d build || mkdir build
+ifeq ($(OS),Windows_NT)
+  RM = cmd /C del /Q /F /S
+  MKBUILD = if not exist build mkdir build
+endif
+
+all example:
+	true
+
+build: pico-sdk
+	$(MKBUILD)
+	cd build && cmake -G "Unix Makefiles" .. && make
+
+pico-sdk:
+	git clone --depth 1 -b 1.4.0 https://github.com/raspberrypi/pico-sdk $@
+	cd $@ && git submodule update --init
+
+clean:
+	$(RM) pico-sdk build

examples/rp2040/pico-rndis-device/README.md

@@ -0,0 +1,30 @@
+# Remote MQTT Device on an RP2040
+
+Your headless Raspberry Pi Pico-based hardware can also be a remote gadget when you connect it to your computer via USB
+
+For the USB specifics, see this related tutorial at https://mongoose.ws/tutorials/rp2040/pico-rndis-dashboard/
+
+See this tutorial to control your device: https://mongoose.ws/tutorials/mqtt-dashboard/
+
+For this to work, you need your computer to act as a router (gateway) and NAT for your device.
+
+## Linux setup
+
+Enable "masquerading"; the quick and simple options are:
+
+``` bash
+sudo iptables --flush
+sudo iptables --table nat --flush
+sudo iptables --delete-chain
+sudo iptables --table nat --delete-chain
+
+# Do masquerading
+sudo iptables -t nat -A POSTROUTING -o yourifc -j MASQUERADE
+# enable routing
+sudo echo 1 > /proc/sys/net/ipv4/ip_forward
+```
+
+Where `yourifc` is the interface that is connected to your network
+
+## MacOS setup
+

examples/rp2040/pico-rndis-device/hal.h

@@ -0,0 +1,11 @@
+// Copyright (c) 2023 Cesanta Software Limited
+// All rights reserved
+
+#define LED PICO_DEFAULT_LED_PIN
+
+static inline int gpio_read(uint16_t pin) {
+  return gpio_get_out_level(pin);
+}
+static inline void gpio_write(uint16_t pin, bool val) {
+  gpio_put(pin, val);
+}

examples/rp2040/pico-rndis-device/main.c

@@ -0,0 +1,89 @@
+// Copyright (c) 2022 Cesanta Software Limited
+// All rights reserved
+
+#include "mongoose.h"
+#include "net.h"
+#include "pico/stdlib.h"
+#include "tusb.h"
+
+bool hal_gpio_read(int pin) {
+  return (pin >= 0 && pin <= 29) ? gpio_get_out_level((uint) pin) : false;
+}
+
+void hal_gpio_write(int pin, bool val) {
+  if (pin >= 0 && pin <= 29) gpio_put((uint) pin, val);
+}
+
+int hal_led_pin(void) {
+  return PICO_DEFAULT_LED_PIN;
+}
+
+static struct mg_tcpip_if *s_ifp;
+
+const uint8_t tud_network_mac_address[6] = {2, 2, 0x84, 0x6A, 0x96, 0};
+
+bool tud_network_recv_cb(const uint8_t *buf, uint16_t len) {
+  mg_tcpip_qwrite((void *) buf, len, s_ifp);
+  // MG_INFO(("RECV %hu", len));
+  // mg_hexdump(buf, len);
+  tud_network_recv_renew();
+  return true;
+}
+
+void tud_network_init_cb(void) {
+}
+
+uint16_t tud_network_xmit_cb(uint8_t *dst, void *ref, uint16_t arg) {
+  // MG_INFO(("SEND %hu", arg));
+  memcpy(dst, ref, arg);
+  return arg;
+}
+
+static size_t usb_tx(const void *buf, size_t len, struct mg_tcpip_if *ifp) {
+  if (!tud_ready()) return 0;
+  while (!tud_network_can_xmit(len)) tud_task();
+  tud_network_xmit((void *) buf, len);
+  (void) ifp;
+  return len;
+}
+
+static bool usb_up(struct mg_tcpip_if *ifp) {
+  (void) ifp;
+  return tud_inited() && tud_ready() && tud_connected();
+}
+
+static void fn(struct mg_connection *c, int ev, void *ev_data, void *fn_dta) {
+  if (ev == MG_EV_HTTP_MSG) return mg_http_reply(c, 200, "", "ok\n");
+}
+
+int main(void) {
+  gpio_init(PICO_DEFAULT_LED_PIN);
+  gpio_set_dir(PICO_DEFAULT_LED_PIN, GPIO_OUT);
+  stdio_init_all();
+
+  struct mg_mgr mgr;  // Initialise Mongoose event manager
+  mg_mgr_init(&mgr);  // and attach it to the interface
+
+  struct mg_tcpip_driver driver = {.tx = usb_tx, .up = usb_up};
+  struct mg_tcpip_if mif = {.mac = {2, 0, 1, 2, 3, 0x77},
+                            .ip = mg_htonl(MG_U32(192, 168, 3, 1)),
+                            .mask = mg_htonl(MG_U32(255, 255, 255, 0)),
+                            .enable_dhcp_server = true,
+                            .enable_get_gateway = true,
+                            .driver = &driver,
+                            .recv_queue.size = 4096};
+  s_ifp = &mif;
+  mg_tcpip_init(&mgr, &mif);
+  tusb_init();
+
+  MG_INFO(("Initialising application..."));
+  web_init(&mgr);
+
+  MG_INFO(("Starting event loop"));
+  for (;;) {
+    mg_mgr_poll(&mgr, 0);
+    tud_task();
+  }
+
+  return 0;
+}

examples/rp2040/pico-rndis-device/mongoose.c

@@ -0,0 +1 @@
+../../../mongoose.c

examples/rp2040/pico-rndis-device/mongoose.h

@@ -0,0 +1 @@
+../../../mongoose.h

examples/rp2040/pico-rndis-device/net.c

@@ -0,0 +1 @@
+../../mqtt-dashboard/device/net.c

examples/rp2040/pico-rndis-device/net.h

@@ -0,0 +1 @@
+../../mqtt-dashboard/device/net.h

examples/rp2040/pico-rndis-device/netif/ethernet.h

@@ -0,0 +1,2 @@
+#pragma once
+#define SIZEOF_ETH_HDR 14

examples/rp2040/pico-rndis-device/tusb_config.h

@@ -0,0 +1,9 @@
+#pragma once
+
+// Windows only supports RNDIS
+// Mac only supports CDC-ECM
+// Linux supports either RNDIS, CDC-ECM or CDC-NCM
+#define CFG_TUD_ECM_RNDIS         1
+#define BOARD_DEVICE_RHPORT_NUM   0
+#define BOARD_DEVICE_RHPORT_SPEED OPT_MODE_FULL_SPEED
+#define CFG_TUSB_RHPORT0_MODE     (OPT_MODE_DEVICE | BOARD_DEVICE_RHPORT_SPEED)