Add AsyncUDP and simple NetBIOS name lookup server (#2234)

Thanks to @me-no-dev's code.  Lets Windows look up the PicoW by name
using NBNS and needs much less memory and code than mDNS.

AsyncUDP ported from the old ESP8266 version, only minimal changes.  Will
probably only be valid in IPv4 environments and may not match current
ESP32 AsyncUDP interfaces.

.github/workflows/pull-request.yml

@@ -25,7 +25,7 @@ jobs:
       uses: codespell-project/actions-codespell@master
       with:
         skip: ./ArduinoCore-API,./libraries/ESP8266SdFat,./libraries/Adafruit_TinyUSB_Arduino,./libraries/LittleFS/lib,./tools/pyserial,./pico-sdk,./.github,./docs/i2s.rst,./cores/rp2040/api,./libraries/FreeRTOS,./tools/libbearssl/bearssl,./include,./libraries/WiFi/examples/BearSSL_Server,./ota/uzlib,./libraries/http-parser/lib,./libraries/WebServer/examples/HelloServerBearSSL/HelloServerBearSSL.ino,./libraries/HTTPUpdateServer/examples/SecureBearSSLUpdater/SecureBearSSLUpdater.ino,./.git,./libraries/FatFS/lib/fatfs,./libraries/FatFS/src/diskio.h,./libraries/FatFS/src/ff.cpp,./libraries/FatFS/src/ffconf.h,./libraries/FatFS/src/ffsystem.cpp,./libraries/FatFS/src/ff.h,./libraries/lwIP_WINC1500/src/driver,./libraries/lwIP_WINC1500/src/common,./libraries/lwIP_WINC1500/src/bus_wrapper,./libraries/lwIP_WINC1500/src/spi_flash
-        ignore_words_list: ser,dout,shiftIn
+        ignore_words_list: ser,dout,shiftIn,acount
 
 # Consistent style
   astyle:

.gitmodules

@@ -40,3 +40,6 @@
 [submodule "libraries/FatFS/lib/SPIFTL"]
 	path = libraries/FatFS/lib/SPIFTL
 	url = https://github.com/earlephilhower/SPIFTL.git
+[submodule "libraries/AsyncUDP"]
+	path = libraries/AsyncUDP
+	url = https://github.com/earlephilhower/AsyncUDP.git

AsyncUDP @ dd32bfa7

+Subproject commit dd32bfa7d92783cbbede75bb343853d317d3a6a8

libraries/NetBIOS/examples/PicoW_NetBIOS/PicoW_NetBIOS.ino

+// Modified from the ESP32-NetBIOS example
+
+#include <WiFi.h>
+#include <NetBIOS.h>
+
+#ifndef STASSID
+#define STASSID "your-ssid"
+#define STAPSK "your-password"
+#endif
+
+const char* ssid = STASSID;
+const char* password = STAPSK;
+
+void setup() {
+  Serial.begin(115200);
+
+  // Connect to WiFi network
+  WiFi.mode(WIFI_STA);
+  WiFi.begin(ssid, password);
+  Serial.println("");
+
+  // Wait for connection
+  while (WiFi.status() != WL_CONNECTED) {
+    delay(500);
+    Serial.print(".");
+  }
+  Serial.println("");
+  Serial.print("Connected to ");
+  Serial.println(ssid);
+  Serial.print("IP address: ");
+  Serial.println(WiFi.localIP());
+
+  // Windows (and other OSes using WINS/NetBIOS resolution should now be able to find the device by name)
+  NBNS.begin("PicoW");
+}
+
+void loop() {}

libraries/NetBIOS/keywords.txt

+#######################################
+# Syntax Coloring Map For ESPNBNS
+#######################################
+
+#######################################
+# Datatypes (KEYWORD1)
+#######################################
+
+NetBIOS	KEYWORD1
+
+#######################################
+# Methods and Functions (KEYWORD2)
+#######################################
+
+begin	KEYWORD2
+
+#######################################
+# Instances (KEYWORD2)
+#######################################
+
+NBNS	KEYWORD2
+
+#######################################
+# Constants (LITERAL1)
+#######################################

libraries/NetBIOS/library.properties

+name=NetBIOS
+version=2.0.0
+author=Pablo@xpablo.cz
+maintainer=Earle F. Philhower, III <earlephilhower@yahoo.com>
+sentence=Enables NBNS (NetBIOS) name resolution.
+paragraph=With this library you can connect to your ESP from Windows using a short name
+category=Communication
+url=http://www.xpablo.cz/?p=751#more-751
+architectures=rp2040

libraries/NetBIOS/src/NetBIOS.cpp

+#include "NetBIOS.h"
+#include <functional>
+#include <lwip/netif.h>
+
+#define NBNS_PORT             137
+#define NBNS_MAX_HOSTNAME_LEN 32
+
+typedef struct {
+    uint16_t id;
+    uint8_t flags1;
+    uint8_t flags2;
+    uint16_t qcount;
+    uint16_t acount;
+    uint16_t nscount;
+    uint16_t adcount;
+    uint8_t name_len;
+    char name[NBNS_MAX_HOSTNAME_LEN + 1];
+    uint16_t type;
+    uint16_t clas;
+} __attribute__((packed)) nbns_question_t;
+
+typedef struct {
+    uint16_t id;
+    uint8_t flags1;
+    uint8_t flags2;
+    uint16_t qcount;
+    uint16_t acount;
+    uint16_t nscount;
+    uint16_t adcount;
+    uint8_t name_len;
+    char name[NBNS_MAX_HOSTNAME_LEN + 1];
+    uint16_t type;
+    uint16_t clas;
+    uint32_t ttl;
+    uint16_t data_len;
+    uint16_t flags;
+    uint32_t addr;
+} __attribute__((packed)) nbns_answer_t;
+
+static void _getnbname(const char *nbname, char *name, uint8_t maxlen) {
+    uint8_t b;
+    uint8_t c = 0;
+
+    while ((*nbname) && (c < maxlen)) {
+        b = (*nbname++ - 'A') << 4;
+        c++;
+        if (*nbname) {
+            b |= *nbname++ - 'A';
+            c++;
+        }
+        if (!b || b == ' ') {
+            break;
+        }
+        *name++ = b;
+    }
+    *name = 0;
+}
+
+static void append_16(void *dst, uint16_t value) {
+    uint8_t *d = (uint8_t *)dst;
+    *d++ = (value >> 8) & 0xFF;
+    *d++ = value & 0xFF;
+}
+
+static void append_32(void *dst, uint32_t value) {
+    uint8_t *d = (uint8_t *)dst;
+    *d++ = (value >> 24) & 0xFF;
+    *d++ = (value >> 16) & 0xFF;
+    *d++ = (value >> 8) & 0xFF;
+    *d++ = value & 0xFF;
+}
+
+void NetBIOS::_onPacket(AsyncUDPPacket &packet) {
+    if (packet.length() >= sizeof(nbns_question_t)) {
+        nbns_question_t *question = (nbns_question_t *)packet.data();
+        if (0 == (question->flags1 & 0x80)) {
+            char name[NBNS_MAX_HOSTNAME_LEN + 1];
+            _getnbname(&question->name[0], (char *)&name, question->name_len);
+            if (_name.equals(name)) {
+                nbns_answer_t nbnsa;
+                nbnsa.id = question->id;
+                nbnsa.flags1 = 0x85;
+                nbnsa.flags2 = 0;
+                append_16((void *)&nbnsa.qcount, 0);
+                append_16((void *)&nbnsa.acount, 1);
+                append_16((void *)&nbnsa.nscount, 0);
+                append_16((void *)&nbnsa.adcount, 0);
+                nbnsa.name_len = question->name_len;
+                memcpy(&nbnsa.name[0], &question->name[0], question->name_len + 1);
+                append_16((void *)&nbnsa.type, 0x20);
+                append_16((void *)&nbnsa.clas, 1);
+                append_32((void *)&nbnsa.ttl, 300000);
+                append_16((void *)&nbnsa.data_len, 6);
+                append_16((void *)&nbnsa.flags, 0);
+                nbnsa.addr = packet.localIP(); // Wrong, but better than nothing
+                // Iterate over all netifs, see if the incoming address matches one of the netmaskes networks
+                // TODO - is there an easier way of seeing whicn netif produced a packet?
+                for (auto netif = netif_list; netif; netif = netif->next) {
+                    auto maskedip = ip4_addr_get_u32(netif_ip4_addr(netif)) & ip4_addr_get_u32(netif_ip4_netmask(netif));
+                    auto maskedin = ((uint32_t)packet.localIP()) & ip4_addr_get_u32(netif_ip4_netmask(netif));
+                    if (maskedip == maskedin) {
+                        nbnsa.addr = ip4_addr_get_u32(netif_ip4_addr(netif));
+                        break;
+                    }
+                }
+                _udp.writeTo((uint8_t *)&nbnsa, sizeof(nbnsa), packet.remoteIP(), NBNS_PORT);
+            }
+        }
+    }
+}
+
+NetBIOS::NetBIOS() {}
+
+NetBIOS::~NetBIOS() {
+    end();
+}
+
+bool NetBIOS::begin(const char *name) {
+    _name = name;
+    _name.toUpperCase();
+
+    if (_udp.connected()) {
+        return true;
+    }
+
+    _udp.onPacket(
+    [](void *arg, AsyncUDPPacket & packet) {
+        ((NetBIOS *)(arg))->_onPacket(packet);
+    },
+    this
+    );
+    return _udp.listen(NBNS_PORT);
+}
+
+void NetBIOS::end() {
+    if (_udp.connected()) {
+        _udp.close();
+    }
+}
+
+NetBIOS NBNS;

libraries/NetBIOS/src/NetBIOS.h

+//
+
+#pragma once
+
+#include <Arduino.h>
+#include <AsyncUDP.h>
+
+class NetBIOS {
+protected:
+    AsyncUDP _udp;
+    String _name;
+    void _onPacket(AsyncUDPPacket &packet);
+
+public:
+    NetBIOS();
+    ~NetBIOS();
+    bool begin(const char *name);
+    void end();
+};
+
+extern NetBIOS NBNS;

tests/restyle.sh

@@ -16,7 +16,7 @@ for dir in ./cores/rp2040 ./libraries/EEPROM ./libraries/I2S ./libraries/SingleF
            ./libraries/lwIP_w5500 ./libraries/lwIP_w5100 ./libraries/lwIP_enc28j60 \
            ./libraries/SPISlave ./libraries/lwIP_ESPHost ./libraries/FatFS\
            ./libraries/FatFSUSB ./libraries/BluetoothAudio ./libraries/BluetoothHCI \
-           ./libraries/BluetoothHIDMaster; do
+           ./libraries/BluetoothHIDMaster ./libraries/NetBIOS; do
     find $dir -type f \( -name "*.c" -o -name "*.h" -o -name "*.cpp" \) -a  \! -path '*api*' -exec astyle --suffix=none --options=./tests/astyle_core.conf \{\} \;
     find $dir -type f -name "*.ino" -exec astyle --suffix=none --options=./tests/astyle_examples.conf \{\} \;
 done