add own mDNS files

EXmDNS.cpp

@@ -0,0 +1,139 @@
+
+#include <Arduino.h>
+#include "EthernetInterface.h"
+#include "EXmDNS.h"
+#include "DIAG.h"
+static IPAddress mdnsMulticastIPAddr = IPAddress(224, 0, 0, 251);
+#define MDNS_SERVER_PORT 5353
+
+MDNS::MDNS(EthernetUDP& udp) {
+  _udp = &udp;
+}
+MDNS::~MDNS() {
+  _udp->stop();
+}
+int MDNS::begin(const IPAddress& ip, char* name) {
+  // if we were called very soon after the board was booted, we need to give the
+  // EthernetShield (WIZnet) some time to come up. Hence, we delay until millis() is at
+  // least 3000. This is necessary, so that if we need to add a service record directly
+  // after begin, the announce packet does not get lost in the bowels of the WIZnet chip.
+  //while (millis() < 3000) 
+  //  delay(100);
+  
+  _ipAddress = ip;
+  _name = name;
+  return _udp->beginMulticast(mdnsMulticastIPAddr, MDNS_SERVER_PORT);
+}
+int MDNS::addServiceRecord(const char* name, uint16_t port, MDNSServiceProtocol_t proto) {
+  // we ignore proto, assume TCP
+  _serviceName = (char *)malloc(strlen(name +2));
+  DIAG("name %d %s", strlen(name), name);
+  byte n;
+  for(n = 0; n<strlen(name); n++)
+    _serviceName[n+1] = name[n];
+  _serviceName[n+1] = '\0';
+  //strcpy(&_serviceName[1], name);
+  _serviceName[0] = (byte)strlen(name);
+  DIAG("sn %d", *_serviceName);
+  _servicePort = port;
+  DIAG("Sevicename %d %s", strlen(_serviceName), _serviceName);
+  return 1;
+}
+
+static char dns_rr_services[]   = "\x09_services\x07_dns-sd\x04_udp\x05local";
+static char dns_rr_withrottle[] = "\x0b_withrottle\x04_tcp\x05local";
+static char *dns_rr_tcplocal    = dns_rr_withrottle + dns_rr_withrottle[0] + 1; // jump over first record
+static char *dns_rr_local       = dns_rr_tcplocal + dns_rr_tcplocal[0] + 1;
+
+typedef struct _DNSHeader_t 
+{
+  uint16_t    xid;
+  uint16_t  flags;
+  /*
+  uint8_t     recursionDesired    : 1;
+  uint8_t     truncated           : 1;
+  uint8_t     authoritiveAnswer   : 1;
+  uint8_t     opCode              : 4;
+  uint8_t     queryResponse       : 1;
+  uint8_t     responseCode        : 4;
+  uint8_t     checkingDisabled    : 1;
+  uint8_t     authenticatedData   : 1;
+  uint8_t     zReserved           : 1;
+  uint8_t     recursionAvailable  : 1;
+  */
+  uint16_t    queryCount;
+  uint16_t    answerCount;
+  uint16_t    authorityCount;
+  uint16_t    additionalCount;
+} __attribute__((__packed__)) DNSHeader_t;
+
+void MDNS::run() {
+  static long int lastrun = 10000;
+  unsigned long int now = millis();
+  if (!(now - lastrun > 10000)) {
+    return;
+  }
+  lastrun = now;
+  DNSHeader_t dnsHeader = { 0 };
+
+  _udp->beginPacket(mdnsMulticastIPAddr, MDNS_SERVER_PORT);
+
+  // dns header
+  dnsHeader.flags = lwip_htons(0x8400); // Response, authorative
+  dnsHeader.answerCount = lwip_htons(4 /*5*/);
+  _udp->write((uint8_t*)&dnsHeader, sizeof(DNSHeader_t));
+  // rr #1
+  _udp->write((uint8_t*)dns_rr_services, sizeof(dns_rr_services));
+  byte buf[10];
+  buf[0] = 0x00;
+  buf[1] = 0x0c;                           //PTR
+  buf[2] = 0x00;
+  buf[3] = 0x01;                           //IN
+  *((uint32_t*)(buf+4)) = lwip_htonl(120); //TTL in sec
+  *((uint16_t*)(buf+8)) = lwip_htons(sizeof(dns_rr_withrottle));
+  _udp->write(buf, 10);
+  _udp->write(dns_rr_withrottle, sizeof(dns_rr_withrottle));
+  // rr #2
+  _udp->write(dns_rr_withrottle, sizeof(dns_rr_withrottle));
+  *((uint16_t*)(buf+8)) = lwip_htons(strlen(_serviceName) + sizeof(dns_rr_withrottle)); // recycle most of buf
+  _udp->write(buf, 10);
+
+  _udp->write(_serviceName, _serviceName[0]+1);
+  _udp->write(dns_rr_withrottle, sizeof(dns_rr_withrottle));
+  // rr #3
+  _udp->write(_serviceName, _serviceName[0]+1);
+  _udp->write(dns_rr_withrottle, sizeof(dns_rr_withrottle));
+
+  buf[1] = 0x21;                                  // recycle most of buf but here SRV
+  buf[2] = 0x80;                                  // cache flush
+  *((uint16_t*)(buf+8)) = lwip_htons(strlen(_serviceName) + strlen(dns_rr_local) + 1 + 6);
+  _udp->write(buf, 10);
+
+  byte srv[6];
+  // priority and weight
+  srv[0] = srv[1] = srv[2] = srv[3] = 0;
+  // port
+  *((uint16_t*)(srv+4)) = lwip_htons(_servicePort);
+  _udp->write(srv, 6);
+  // target
+  _udp->write(_serviceName, _serviceName[0]+1);
+  _udp->write(dns_rr_local, strlen(dns_rr_local)+1);
+
+  // rr #4
+  _udp->write(_serviceName, _serviceName[0]+1);
+  _udp->write(dns_rr_local, strlen(dns_rr_local)+1);
+  
+  buf[1] = 0x01;                                  // recycle most of buf but here A
+  *((uint16_t*)(buf+8)) = lwip_htons(4);
+  _udp->write(buf, 10);
+  byte ip[4];
+  ip[0] = _ipAddress[0];
+  ip[1] = _ipAddress[1];
+  ip[2] = _ipAddress[2];
+  ip[3] = _ipAddress[3];
+  _udp->write(ip, 4);
+  
+  _udp->endPacket();
+  _udp->flush();
+  // 
+}

EXmDNS.h

@@ -0,0 +1,20 @@
+typedef enum _MDNSServiceProtocol_t 
+{
+  MDNSServiceTCP,
+  MDNSServiceUDP
+} MDNSServiceProtocol_t;
+
+class MDNS {
+public:
+  MDNS(EthernetUDP& udp);
+  ~MDNS();
+  int begin(const IPAddress& ip,  char* name);
+  int addServiceRecord(const char* name, uint16_t port, MDNSServiceProtocol_t proto);
+  void run();
+private:
+  EthernetUDP *_udp;
+  IPAddress _ipAddress;
+  char* _name;
+  char* _serviceName;
+  int _servicePort;
+};