first commitHEADmaster

1 files changed, 233 insertions, 0 deletions

diff --git a/portal.ino b/portal.ino
new file mode 100644
index 0000000..b688a6b
--- /dev/null
+++ b/portal.ino
@@ -0,0 +1,233 @@
+/* Portal */
+#include <ESP8266WiFi.h>
+#include <ESP8266WebServer.h>
+#include <WiFiUdp.h>
+
+
+/* DNSServer.h */
+
+#define DNS_QR_QUERY 0
+#define DNS_QR_RESPONSE 1
+#define DNS_OPCODE_QUERY 0
+
+enum class DNSReplyCode
+{
+  NoError = 0,
+  FormError = 1,
+  ServerFailure = 2,
+  NonExistentDomain = 3,
+  NotImplemented = 4,
+  Refused = 5,
+  YXDomain = 6,
+  YXRRSet = 7,
+  NXRRSet = 8
+};
+
+struct DNSHeader
+{
+  uint16_t ID;               // identification number
+  unsigned char RD : 1;      // recursion desired
+  unsigned char TC : 1;      // truncated message
+  unsigned char AA : 1;      // authoritive answer
+  unsigned char OPCode : 4;  // message_type
+  unsigned char QR : 1;      // query/response flag
+  unsigned char RCode : 4;   // response code
+  unsigned char Z : 3;       // its z! reserved
+  unsigned char RA : 1;      // recursion available
+  uint16_t QDCount;          // number of question entries
+  uint16_t ANCount;          // number of answer entries
+  uint16_t NSCount;          // number of authority entries
+  uint16_t ARCount;          // number of resource entries
+};
+
+class DNSServer
+{
+  public:
+    DNSServer();
+    void processNextRequest();
+    
+    // Returns true if successful, false if there are no sockets available
+    bool start(const IPAddress &resolvedIP);
+    // stops the DNS server
+    void stop();
+
+  private:
+    WiFiUDP _udp;
+    uint16_t _port;
+    String _domainName;
+    unsigned char _resolvedIP[4];
+    int _currentPacketSize;
+    unsigned char* _buffer;
+    DNSHeader* _dnsHeader;
+    uint32_t _ttl;
+    DNSReplyCode _errorReplyCode;
+    
+    bool requestIncludesOnlyOneQuestion();
+    String getDomainName();
+    void replyWithIP();
+};
+/* end DNSServer.h */
+
+
+/* main code */
+
+DNSServer dns;
+ESP8266WebServer server(80);
+
+#define LOGLENGTH 50
+String domainlog[LOGLENGTH];
+int logptr = 0;
+
+void logDomain(String requestUrl) {
+  if (++logptr == LOGLENGTH) {
+    logptr = 0;
+  }
+  domainlog[logptr] = requestUrl;
+}
+
+void serve() {
+  String answer = "";
+  for (int i=0; i<logptr; i++) {
+    answer.concat(domainlog[i]);
+    answer += "\n";
+  }
+  server.send(200, "text/plain", answer);
+}
+
+void setup() {
+  WiFi.softAP("Portal");
+  IPAddress ip = WiFi.softAPIP();
+
+  dns.start(ip);
+  
+  server.onNotFound(serve);
+  server.begin();
+}
+
+void loop() {
+  dns.processNextRequest();
+  server.handleClient();
+}
+
+/* end main code */
+
+
+/* modified DNSServer.cpp */
+
+#include <lwip/def.h>
+#include <Arduino.h>
+
+DNSServer::DNSServer()
+{
+  _ttl = htonl(600);
+  _errorReplyCode = DNSReplyCode::NonExistentDomain;
+}
+
+bool DNSServer::start(const IPAddress &resolvedIP)
+{
+  _port = 53;
+  _buffer = NULL;
+  _resolvedIP[0] = resolvedIP[0];
+  _resolvedIP[1] = resolvedIP[1];
+  _resolvedIP[2] = resolvedIP[2];
+  _resolvedIP[3] = resolvedIP[3];
+  return _udp.begin(_port) == 1;
+}
+
+void DNSServer::stop()
+{
+  _udp.stop();
+  free(_buffer);
+  _buffer = NULL;
+}
+
+void DNSServer::processNextRequest()
+{
+  _currentPacketSize = _udp.parsePacket();
+  if (_currentPacketSize)
+  {    
+    if (_buffer != NULL) free(_buffer);
+    _buffer = (unsigned char*)malloc(_currentPacketSize * sizeof(char));
+    if (_buffer == NULL) return;
+    _udp.read(_buffer, _currentPacketSize);
+
+    _dnsHeader = (DNSHeader*) _buffer;
+
+    if (_dnsHeader->QR == DNS_QR_QUERY &&
+        _dnsHeader->OPCode == DNS_OPCODE_QUERY &&
+        requestIncludesOnlyOneQuestion())
+    {
+        logDomain(getDomainName());
+        replyWithIP();  // reply with the same ip regardless of request
+    }
+  }
+}
+
+String DNSServer::getDomainName()
+{
+  String parsedDomainName = "";
+  if (_buffer == NULL) return parsedDomainName;
+  unsigned char *start = _buffer + 12;
+  if (*start == 0)
+  {
+    return parsedDomainName;
+  }
+  int pos = 0;
+  while(true)
+  {
+    unsigned char labelLength = *(start + pos);
+    for(int i = 0; i < labelLength; i++)
+    {
+      pos++;
+      parsedDomainName += (char)*(start + pos);
+    }
+    pos++;
+    if (*(start + pos) == 0)
+    {
+      return parsedDomainName;
+    }
+    else
+    {
+      parsedDomainName += ".";
+    }
+  }
+}
+
+bool DNSServer::requestIncludesOnlyOneQuestion()
+{
+  return ntohs(_dnsHeader->QDCount) == 1 &&
+         _dnsHeader->ANCount == 0 &&
+         _dnsHeader->NSCount == 0 &&
+         _dnsHeader->ARCount == 0;
+}
+
+void DNSServer::replyWithIP()
+{
+  if (_buffer == NULL) return;
+  _dnsHeader->QR = DNS_QR_RESPONSE;
+  _dnsHeader->ANCount = _dnsHeader->QDCount;
+  _dnsHeader->QDCount = _dnsHeader->QDCount; 
+  //_dnsHeader->RA = 1;  
+
+  _udp.beginPacket(_udp.remoteIP(), _udp.remotePort());
+  _udp.write(_buffer, _currentPacketSize);
+
+  _udp.write((uint8_t)192); //  answer name is a pointer
+  _udp.write((uint8_t)12);  // pointer to offset at 0x00c
+
+  _udp.write((uint8_t)0);   // 0x0001  answer is type A query (host address)
+  _udp.write((uint8_t)1);
+
+  _udp.write((uint8_t)0);   //0x0001 answer is class IN (internet address)
+  _udp.write((uint8_t)1);
+ 
+  _udp.write((unsigned char*)&_ttl, 4);
+
+  // Length of RData is 4 bytes (because, in this case, RData is IPv4)
+  _udp.write((uint8_t)0);
+  _udp.write((uint8_t)4);
+  _udp.write(_resolvedIP, sizeof(_resolvedIP));
+  _udp.endPacket();
+}
+
+/* end DNSServer.cpp */