Added automatic conversion of IP addresses. Allows a more feasible wa…

…y to use the cmd line.

README.md

@@ -22,7 +22,7 @@ Usage
 
 This is the help from dines.
 
-    Dines 0.3 - The definitive DNS packet forger.
+    Dines 0.4 - The definitive DNS packet forger.
 
     Fields with (F) can be fuzzed. (Example --txid F)
     Fields with (R) are repeatable. (Example --answer)
@@ -69,6 +69,10 @@ To generate a question, issue the follogin command:
 that asks for domain www.test.com, sending 1 packet only. To generate an answer, one can use the following
 command
 
-    sudo ./dines --src-ip 192.168.1.1 --dst-ip 192.168.1.2 --question www.google.com,1,1 --num 1 --answer www.google.com,1,1,256,$'\xc0\xa8\01\01' --answer www.google.com,1,1,256,$'\xc0\xa8\01\02'
+    sudo ./dines --src-ip 192.168.1.1 --dst-ip 192.168.1.2 --question www.test.com,1,1 --num 1 --rdata-ip --answer www.test.com,1,1,256,192.168.1.1 --answer www.test.com,1,1,256,192.168.1.2
 
-The switches related to resource records can be repeated multiple times.
+The switches related to resource records can be repeated multiple times. In order to specify IP addresses on
+the command line, the user must use the --rdata-ip switch. Otherwise, data will we used as is. This allows
+to inject binary data directly, as in the following example
+
+    sudo ./dines --src-ip 192.168.1.1 --dst-ip 192.168.1.2 --question www.test.com,NULL,IN --num 1 --answer www.test.com,NULL,IN,0,$'\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a'

convert.cpp

@@ -34,6 +34,7 @@ uint16_t stringToQtype(const std::string& s)
     if (s == "A") return 1;
     if (s == "NS") return 2;
     if (s == "CNAME") return 5;
+    if (s == "NULL") return 10;
     if (s == "PTR") return 12;
     if (s == "HINFO") return 13;
     if (s == "MX") return 15;
@@ -47,7 +48,7 @@ uint16_t stringToQtype(const std::string& s)
     unsigned n = atoi(s.c_str());
 
     if (n > 0xFFFF || n == 0) {
-        throw runtime_error(string(__func__) + "Invalid qtype");
+        throw runtime_error(string(__func__) + ": Invalid qtype");
     }
 
     return n;
@@ -62,6 +63,8 @@ string qtypeToString(uint16_t qtype)
             return "NS";
         case 5:
             return "CNAME";
+        case 10:
+            return "NULL";
         case 12:
             return "PTR";
         case 13:
@@ -75,7 +78,7 @@ string qtypeToString(uint16_t qtype)
         case 255:
             return "ANY";
         default:
-            throw logic_error(string(__func__) + "Invalid qtype");
+            throw logic_error(string(__func__) + ": Invalid qtype");
     }
 }
 
@@ -91,7 +94,7 @@ uint16_t stringToQclass(const std::string& s)
     if (s == "F") return 1;
 
     // Invalid class
-    throw runtime_error(string(__func__) + "Invalid qclass");
+    throw runtime_error(string(__func__) + ": Invalid qclass");
 }
 
 string qclassToString(uint16_t qclass)
@@ -110,6 +113,6 @@ string qclassToString(uint16_t qclass)
         case 255:
             return "ANY";
         default:
-            throw logic_error(string(__func__) + "Invalid qclass");
+            throw logic_error(string(__func__) + ": Invalid qclass");
     }
 }

dns_packet.cpp

@@ -46,6 +46,8 @@ DnsPacket::DnsPacket(Dines::LogFunc l)
     _fuzzSrcIp = false;
     _fuzzSport = false;
 
+    _rDataIp = false;
+
     _log = l;
 
     if (_log != NULL)
@@ -290,25 +292,35 @@ DnsQuestion& DnsPacket::addQuestion(const std::string qdomain, unsigned qtype, u
     return _question;
 }
 
-ResourceRecord& DnsPacket::addRR(Dines::RecordSection section, const std::string& rrDomain, unsigned rrType,
-        unsigned rrClass, unsigned ttl, const char* rdata, unsigned rdatalen)
+ResourceRecord& DnsPacket::addRR(Dines::RecordSection section, const std::string& rrDomain,
+        unsigned rrType, unsigned rrClass, unsigned ttl, const char* rdata, unsigned rdatalen)
 {
     string rd(rdata, rdatalen);
     return addRR(section, rrDomain, rrType, rrClass, ttl, rd);
 }
 
 ResourceRecord& DnsPacket::addRR(Dines::RecordSection section, const std::string rrDomain,
-        const std::string& rrType, const std::string& rrClass, const std::string& ttl, const std::string& rdata)
+        const std::string& rrType, const std::string& rrClass, const std::string& ttl,
+        const std::string& rdata)
 {
     unsigned type = stringToQtype(rrType);
     unsigned klass = stringToQclass(rrClass);
     unsigned int_ttl = atoi(ttl.data());
 
-    return addRR(section, rrDomain, type, klass, int_ttl, rdata);
+    string localrdata = rdata;
+
+    if (_rDataIp) {
+        if (_log)
+            _log("Converting " + rdata + " to IP address");
+        uint32_t addr = _convertIP(rdata);
+        localrdata = string((char*)&addr, 4);
+    }
+
+    return addRR(section, rrDomain, type, klass, int_ttl, localrdata);
 }
 
-ResourceRecord& DnsPacket::addRR(Dines::RecordSection section, const std::string& rrDomain, unsigned rrType,
-        unsigned rrClass, unsigned ttl, const std::string& rdata)
+ResourceRecord& DnsPacket::addRR(Dines::RecordSection section, const std::string& rrDomain,
+        unsigned rrType, unsigned rrClass, unsigned ttl, const std::string& rdata)
 {
     ResourceRecord rr(rrDomain, rrType, rrClass, ttl, rdata);
     return addRR(section, rr);
@@ -410,6 +422,13 @@ void DnsPacket::txid(uint16_t txid)
 
 void DnsPacket::nRecord(Dines::RecordSection section, uint16_t value)
 {
+    char sect[10];
+    char val[11];
+    snprintf(sect, 10, "%u", section);
+    snprintf(val, 11, "%u", value);
+    if (_log)
+        _log("Setting record section " + string(sect) + " to " + string(val));
+
     _dnsHdr.nRecord(section, value);
 }
 
@@ -487,3 +506,36 @@ void DnsPacket::setLogger(Dines::LogFunc l)
 {
     _log = l;
 }
+
+uint32_t DnsPacket::_convertIP(string rdata)
+{
+    uint32_t addr;
+    if (inet_pton(AF_INET, rdata.data(), &addr) != 1)
+        throw runtime_error("Can't convert IP address: " + rdata);
+    return addr;
+}
+
+void DnsPacket::rDataIp()
+{
+    if (_log)
+        _log("Activating IP conversion");
+
+    _rDataIp = true;
+
+    uint32_t addr;
+    for (vector<ResourceRecord>::iterator itr = _answers.begin(); itr != _answers.end();
+            ++itr) {
+        addr = _convertIP(itr->rData());
+        itr->rData(string((char*)&addr, 4));
+    }
+    for (vector<ResourceRecord>::iterator itr = _authorities.begin(); itr != _authorities.end();
+            ++itr) {
+        addr = _convertIP(itr->rData());
+        itr->rData(string((char*)&addr, 4));
+    }
+    for (vector<ResourceRecord>::iterator itr = _additionals.begin(); itr != _additionals.end();
+            ++itr) {
+        addr = _convertIP(itr->rData());
+        itr->rData(string((char*)&addr, 4));
+    }
+}

dns_packet.hpp

@@ -42,6 +42,10 @@ class DnsPacket {
     //! DNS additionals
     std::vector<ResourceRecord> _additionals;
 
+    uint32_t _convertIP(std::string rdata);
+
+    bool _rDataIp;
+
     bool _fuzzSrcIp;
 
     bool _fuzzSport;
@@ -131,6 +135,10 @@ class DnsPacket {
 
     ResourceRecord& addRR(Dines::RecordSection section, const ResourceRecord& rr);
 
+    // Converts existing resource record rdata into IP addresses. Sets also a flag
+    // for future conversions
+    void rDataIp();
+
     void fuzz();
 
     void fuzzSrcIp();