From: Bert Hubert <bert.hubert@netherlabs.nl>
Date: Sun, 4 Oct 2009 07:42:10 +0000 (+0000)
Subject: initial load of the 'MyDNS' compatability backend
X-Git-Tag: rec-3.2~121
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=4dad70693039a752f93ee0ee5cbd1c858cad8803;p=pdns

initial load of the 'MyDNS' compatability backend


git-svn-id: svn://svn.powerdns.com/pdns/trunk/pdns@1418 d19b8d6e-7fed-0310-83ef-9ca221ded41b
---

diff --git a/configure.in b/configure.in
index bf3a20a14..a9a9d20c1 100644
--- a/configure.in
+++ b/configure.in
@@ -214,6 +214,9 @@ do
 		gmysql )
 			needmysql=yes
 		;;
+		mydns )
+			needmysql=yes
+		;;
 		gpgsql )
 			needpgsql=yes
 		;;
@@ -545,4 +548,4 @@ modules/pipebackend/Makefile modules/oraclebackend/Makefile \
 modules/xdbbackend/Makefile modules/odbcbackend/Makefile \
 modules/gpgsqlbackend/Makefile modules/ldapbackend/Makefile 
 modules/gsqlitebackend/Makefile modules/gsqlite3backend/Makefile
-modules/goraclebackend/Makefile )
+modules/goraclebackend/Makefile modules/mydnsbackend/Makefile)
diff --git a/modules/mydnsbackend/Makefile.am b/modules/mydnsbackend/Makefile.am
new file mode 100644
index 000000000..5988bf1e1
--- /dev/null
+++ b/modules/mydnsbackend/Makefile.am
@@ -0,0 +1,7 @@
+AM_CPPFLAGS=@THREADFLAGS@
+INCLUDES=-I@MYSQL_incdir@ 
+lib_LTLIBRARIES = libmydnsbackend.la 
+EXTRA_DIST=OBJECTFILES OBJECTLIBS
+libmydnsbackend_la_SOURCES=mydnsbackend.cc mydnsbackend.hh 
+libmydnsbackend_la_LDFLAGS=-module -avoid-version @MYSQL_lib@ -lmysqlclient
+
diff --git a/modules/mydnsbackend/OBJECTFILES b/modules/mydnsbackend/OBJECTFILES
new file mode 100644
index 000000000..1cd6d2168
--- /dev/null
+++ b/modules/mydnsbackend/OBJECTFILES
@@ -0,0 +1 @@
+mydnsbackend.o 
diff --git a/modules/mydnsbackend/OBJECTLIBS b/modules/mydnsbackend/OBJECTLIBS
new file mode 100644
index 000000000..175432ca4
--- /dev/null
+++ b/modules/mydnsbackend/OBJECTLIBS
@@ -0,0 +1 @@
+-lmysqlclient -lz
diff --git a/modules/mydnsbackend/mydnsbackend.cc b/modules/mydnsbackend/mydnsbackend.cc
new file mode 100644
index 000000000..7c89b556c
--- /dev/null
+++ b/modules/mydnsbackend/mydnsbackend.cc
@@ -0,0 +1,357 @@
+/*
+ * PowerDNS backend module for MyDNS style databases
+ * Author: Jonathan Oddy (Hostway UK) <jonathan@woaf.net>
+ *
+ * The schema used by MyDNS isn't suitable for retrieving results with a single
+ * query. This means that existing PowerDNS backends are unable to make use of
+ * the schema without lame hackery (or awful performance.) This module does
+ * the nasty lookup logic required to make use of the schema, and should be as
+ * tollerent as MyDNS when it comes to things being fully qualified or not.
+ *
+ * A known "bug" is that AXFRs will fail if your rr table contains invalid
+ * junk. I'm not sure this is really a bug, if you've decided to put free-form
+ * text in your data for an A record you have bigger issues.
+ *
+ * I'd advise avoiding the MyDNS schema if at all possible as the query count
+ * for even simple lookups is daft. It's quite trivial to craft a request
+ * that'll require 128 database queries to answer with a servfail!
+ *
+ */
+
+#include <string>
+#include <map>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sstream>
+
+using namespace std;
+
+#include <pdns/dns.hh>
+#include <pdns/dnsbackend.hh>
+#include "mydnsbackend.hh"
+#include <pdns/dnspacket.hh>
+#include <pdns/ueberbackend.hh>
+#include <pdns/ahuexception.hh>
+#include <pdns/logger.hh>
+#include <pdns/arguments.hh>
+
+#include <modules/gmysqlbackend/smysql.hh>
+
+static string backendName="[MyDNSbackend]";
+
+MyDNSBackend::MyDNSBackend(const string &suffix) {
+	setArgPrefix("mydns"+suffix);
+
+	try {
+		d_db = new SMySQL(getArg("dbname"),
+				getArg("host"),
+				getArgAsNum("port"),
+				getArg("socket"),
+				getArg("user"),
+				getArg("password"));
+
+	}
+	catch(SSqlException &e) {
+		L<<Logger::Error<<backendName<<" Connection failed: "<<e.txtReason()<<endl;
+		throw AhuException(backendName+"Unable to launch connection: "+e.txtReason());
+	}
+
+	d_rrtable=getArg("rr-table");
+	d_soatable=getArg("soa-table");
+	d_rrwhere=(mustDo("rr-active")?"active = 1 and ":"")+getArg("rr-where");
+	d_soawhere=(mustDo("soa-active")?"active = 1 and ":"")+getArg("soa-where");
+
+	L<<Logger::Warning<<backendName<<" Connection succesful"<<endl;
+}
+
+MyDNSBackend::~MyDNSBackend() {
+	if (d_db)
+		delete(d_db);
+}
+
+
+void MyDNSBackend::Query(const string &query) {
+	try {
+		d_db->doQuery(query);
+	} catch (SSqlException &e) {
+		throw AhuException("Query failed: "+e.txtReason());
+	}
+}
+
+bool MyDNSBackend::list(const string &target, int zoneId) {
+	string query;
+	string sname;
+	SSql::row_t rrow;
+
+	d_db->setLog(::arg().mustDo("query-logging"));
+
+	query = "select origin, minimum from "+d_soatable+" where id = ";
+	ostringstream o;
+	o<<zoneId;
+	query+=o.str();
+	query+= " and "+d_soawhere;
+
+	this->Query(query);
+
+	if(!d_db->getRow(rrow)) {
+		// No such zone
+		return false;
+	}
+	
+	d_origin = rrow[0];
+	if (d_origin[d_origin.length()-1] == '.')
+		d_origin.erase(d_origin.length()-1);
+	d_minimum = atol(rrow[1].c_str());
+
+	while (d_db->getRow(rrow)) {
+		L<<Logger::Warning<<backendName<<" Found more than one matching origin for zone ID: "+zoneId<<endl;
+	};
+
+	query = "select type, data, aux, ttl, zone, name from "+d_rrtable+" where zone = ";
+	query+=o.str();
+	query += " and "+d_rrwhere;
+
+	this->Query(query);
+
+	d_qname = "";
+	return true;
+
+}
+
+bool MyDNSBackend::getSOA(const string& name, SOAData& soadata, DNSPacket*) {
+	string query;
+	SSql::row_t rrow;
+
+	d_db->setLog(::arg().mustDo("query-logging"));
+
+	if (name.empty())
+		return false;
+
+	query = "select id, mbox, serial, ns, refresh, retry, expire, minimum, ttl from "+d_soatable+" where origin = '";
+
+	if (name.find_first_of("'\\")!=string::npos)
+		query+=d_db->escape(name);
+	else
+		query+=name;
+
+	query+=".' and "+d_soawhere;
+
+	this->Query(query);
+
+	if(!(d_db->getRow(rrow))) {
+		return false;
+	}
+
+	soadata.domain_id = atol(rrow[0].c_str());
+	soadata.hostmaster = rrow[1];
+	soadata.serial = atol(rrow[2].c_str());
+	soadata.nameserver = rrow[3];
+	soadata.refresh = atol(rrow[4].c_str());
+	soadata.retry = atol(rrow[5].c_str());
+	soadata.expire = atol(rrow[6].c_str());
+	soadata.default_ttl = atol(rrow[7].c_str());
+	soadata.ttl = atol(rrow[8].c_str());
+	if (soadata.ttl < soadata.default_ttl) {
+		soadata.ttl = soadata.default_ttl;
+	}
+	soadata.db = this;
+
+	while (d_db->getRow(rrow)) {
+		L<<Logger::Warning<<backendName<<" Found more than one matching zone for: "+name<<endl;
+	};
+
+	return true;
+}
+
+void MyDNSBackend::lookup(const QType &qtype, const string &qname, DNSPacket *p, int zoneId) {
+	string query;
+	string sname;
+	SSql::row_t rrow;
+	bool found = false;
+
+	d_origin = "";
+
+	d_db->setLog(::arg().mustDo("query-logging"));
+
+	if (qname.empty())
+		return;
+
+	// Escape the name, after this point we only want to use it in queries
+	if (qname.find_first_of("'\\")!=string::npos)
+		sname=d_db->escape(qname);
+	else
+		sname = qname;
+	sname += ".";
+
+	if (zoneId < 0) {
+		// First off we need to work out what zone we're working with
+		// MyDNS records aren't always fully qualified, so we need to work out the zone ID.
+		
+		size_t pos;
+		string sdom;
+
+		pos = 0;
+		sdom = sname;
+		while (!sdom.empty() && pos != string::npos) {
+			query = "select id, origin, minimum from "+d_soatable+" where origin = '"+sdom+"' and "+d_soawhere;
+
+			this->Query(query);
+			if(d_db->getRow(rrow)) {
+				zoneId = atol(rrow[0].c_str());
+				d_origin = rrow[1];
+				if (d_origin[d_origin.length()-1] == '.')
+					d_origin.erase(d_origin.length()-1);
+				d_minimum = atol(rrow[2].c_str());
+				found = true;
+				break;
+			}
+
+			pos = sname.find_first_of(".",pos+1);
+			sdom = sname.substr(pos+1);
+		}
+
+	} else {
+		query = "select origin, minimum from "+d_soatable+" where id = ";
+		ostringstream o;
+		o<<zoneId;
+		query+=o.str();
+		query+= " and "+d_soawhere;
+
+		this->Query(query);
+
+		if(!d_db->getRow(rrow)) {
+			throw AhuException("lookup() passed zoneId = "+o.str()+" but no such zone!");
+		}
+		
+		found = true;
+		d_origin = rrow[0];
+		if (d_origin[d_origin.length()-1] == '.')
+			d_origin.erase(d_origin.length()-1);
+		d_minimum = atol(rrow[1].c_str());
+	}
+
+
+	if (found) {
+		while (d_db->getRow(rrow)) {
+			L<<Logger::Warning<<backendName<<" Found more than one matching zone for: "+d_origin<<endl;
+		};
+		// We found the zoneId, so we can work out how to find our rr
+		string host;
+
+		// The host part of the query is the name less the origin
+		if (qname.length() == d_origin.length())
+			host = "";
+		else
+			host = qname.substr(0, (qname.length() - d_origin.length())-1);
+
+		if (host.find_first_of("'\\")!=string::npos)
+			host=d_db->escape(host);
+
+		query = "select type, data, aux, ttl, zone from "+d_rrtable+" where zone = ";
+		ostringstream o;
+		o<<zoneId;
+		query+=o.str();
+		query += " and (name = '"+host+"' or name = '"+sname+"')";
+
+		if(qtype.getCode()!=255) {  // ANY
+			query+=" and type='";
+			query+=qtype.getName();
+			query+="'";
+		}
+		query += " and "+d_rrwhere+" order by type,aux,data";
+
+		this->Query(query);
+
+		d_qname = qname;
+	}
+
+}
+
+bool MyDNSBackend::get(DNSResourceRecord &rr) {
+	if (d_origin.empty()) {
+		// This happens if lookup() couldn't find the zone
+		return false;
+	}
+
+	SSql::row_t rrow;
+
+	if(!d_db->getRow(rrow)) {
+		return false;
+	}
+
+	rr.qtype=rrow[0];
+	rr.content = rrow[1];
+
+	if(!d_qname.empty()) {
+		// use this to distinguish between select with 'name' field (list()) and one without
+		rr.qname=d_qname;
+	} else {
+		rr.qname=rrow[5];
+		if (rr.qname[rr.qname.length()-1] == '.') {
+			rr.qname.erase(rr.qname.length()-1); // Fully qualified, nuke the last .
+		} else {
+			if (!rr.qname.empty())
+				rr.qname += ".";
+			rr.qname += d_origin; // Not fully qualified
+		}
+	}
+
+	if (rr.qtype == "NS" || rr.qtype == "MX" || rr.qtype == "CNAME" || rr.qtype == "PTR") {
+		if (rr.content[rr.content.length()-1] == '.') {
+			rr.content.erase(rr.content.length()-1); // Fully qualified, nuke the last .
+		} else {
+			if (!rr.content.empty())
+				rr.content += ".";
+			rr.content += d_origin;
+		}
+	}
+
+	rr.priority = atol(rrow[2].c_str());
+	rr.ttl = atol(rrow[3].c_str());
+	if (rr.ttl < d_minimum)
+		rr.ttl = d_minimum;
+	rr.domain_id=atol(rrow[4].c_str());
+
+  
+	rr.last_modified=0;
+  
+	return true;
+
+}
+
+class MyDNSFactory : public BackendFactory {
+
+public:
+	MyDNSFactory() : BackendFactory("mydns") {}
+
+	void declareArguments(const string &suffix = "") {
+		declare(suffix,"dbname","Pdns backend database name to connect to","mydns");
+		declare(suffix,"user","Pdns backend user to connect as","powerdns");
+		declare(suffix,"host","Pdns backend host to connect to","");
+		declare(suffix,"port","Pdns backend host to connect to","");
+		declare(suffix,"password","Pdns backend password to connect with","");
+		declare(suffix,"socket","Pdns backend socket to connect to","");
+		declare(suffix,"rr-table","Name of RR table to use","rr");
+		declare(suffix,"soa-table","Name of SOA table to use","soa");
+		declare(suffix,"soa-where","Additional WHERE clause for SOA","1 = 1");
+		declare(suffix,"rr-where","Additional WHERE clause for RR","1 = 1");
+		declare(suffix,"soa-active","Use the active column in the SOA table","yes");
+		declare(suffix,"rr-active","Use the active column in the RR table","yes");
+	}
+
+	MyDNSBackend *make(const string &suffix = "") {
+		return new MyDNSBackend(suffix);
+	}
+
+};
+
+class MyDNSLoader {
+
+public:
+	MyDNSLoader() {
+		BackendMakers().report(new MyDNSFactory());
+		L<<Logger::Info<<backendName<<" This is the MyDNSBackend ("__DATE__", "__TIME__") reporting"<<endl;
+	}
+};
+
+static MyDNSLoader mydnsloader;
diff --git a/modules/mydnsbackend/mydnsbackend.hh b/modules/mydnsbackend/mydnsbackend.hh
new file mode 100644
index 000000000..a4ae01c45
--- /dev/null
+++ b/modules/mydnsbackend/mydnsbackend.hh
@@ -0,0 +1,36 @@
+#ifndef MYDNSBACKEND_HH
+#define MYDNSBACKEND_HH
+
+#include <string>
+#include <map>
+
+using namespace std;
+
+#include <modules/gmysqlbackend/smysql.hh>
+
+class MyDNSBackend : public DNSBackend
+{
+public:
+	MyDNSBackend(const string &suffix="");
+	~MyDNSBackend();
+	MyDNSBackend *parent;
+	
+	void lookup(const QType &, const string &qdomain, DNSPacket *p=0, int zoneId=-1);
+	bool list(const string &target, int domain_id);
+	bool get(DNSResourceRecord &r);
+	bool getSOA(const string& name, SOAData& soadata, DNSPacket*);
+	  
+private:
+	void Query(const string& query);
+	SMySQL *d_db; 
+
+	string d_qname;
+	string d_rrtable;
+	string d_soatable;
+	string d_soawhere;
+	string d_rrwhere;
+	string d_origin;
+	unsigned int d_minimum;
+
+};
+#endif /* MYDNSBACKEND_HH */