Multithreaded DNS -- not tested!!!!

git-svn-id: http://svn.inspircd.org/repository/trunk/inspircd@2088 e03df62e-2008-0410-955e-edbf42e46eb7

include/dns.h

@@ -85,6 +85,7 @@ public:
 	 * called DNS::ReverseLookup() or DNS::ForwardLookup.
 	 */
 	std::string GetResult();
+	std::string GetResultIP();
 	/** This method returns the file handle used by the dns query socket or zero if the
 	 * query is invalid for some reason, e.g. the dns server not responding.
 	 */

include/inspircd.h

@@ -124,3 +124,4 @@ const char* FindServerNamePtr(std::string servername);
 
 std::string GetVersionString();
 
+void* dns_task(void* arg);

include/users.h

@@ -19,6 +19,7 @@
 #include "inspstring.h"
 #include "connection.h"
 #include <string>
+#include <pthread.h>
  
 #ifndef __USERS_H__ 
 #define __USERS_H__ 
@@ -218,8 +219,6 @@ class userrec : public connection
 
 	userrec();
 	
-	virtual ~userrec() {  }
-	
 	/** Returns the full displayed host of the user
 	 * This member function returns the hostname of the user as seen by other users
 	 * on the server, in nick!ident&at;host form.
@@ -318,6 +317,10 @@ class userrec : public connection
 	/** Shuts down and closes the user's socket
 	 */
 	void CloseSocket();
+
+	virtual ~userrec();
+
+	pthread_t dnsthread;
 };
 
 /** A lightweight userrec used by WHOWAS

src/commands.cpp

@@ -50,6 +50,7 @@ using namespace std;
 #include <sys/types.h>
 #include <sys/time.h>
 #include <sys/resource.h>
+#include <pthread.h>
 #ifndef RUSAGE_SELF
 #define   RUSAGE_SELF     0
 #define   RUSAGE_CHILDREN     -1
@@ -1719,9 +1720,16 @@ void handle_nick(char **parameters, int pcnt, userrec *user)
 		user->registered = (user->registered | 2);
 		// dont attempt to look up the dns until they pick a nick... because otherwise their pointer WILL change
 		// and unless we're lucky we'll get a duff one later on.
-		user->dns_done = (!lookup_dns(user->nick));
-		if (user->dns_done)
-			log(DEBUG,"Aborting dns lookup of %s because dns server experienced a failure.",user->nick);
+		//user->dns_done = (!lookup_dns(user->nick));
+		//if (user->dns_done)
+		//	log(DEBUG,"Aborting dns lookup of %s because dns server experienced a failure.",user->nick);
+
+		// initialize their dns lookup thread
+		if (pthread_create(&user->dnsthread, NULL, dns_task, (void *)user) != 0)
+		{
+			log(DEBUG,"Failed to create DNS lookup thread for user %s",user->nick);
+		}
+	
 	}
 	if (user->registered == 3)
 	{

src/dns.cpp

@@ -667,7 +667,13 @@ bool DNS::ReverseLookup(std::string ip)
 
 bool DNS::ForwardLookup(std::string host)
 {
-	return false;
+	statsDns++;
+	this->fd = dns_getip4(host.c_str());
+	if (this->fd == -1)
+	{
+		return false;
+	}
+	return true;
 }
 
 bool DNS::HasResult()
@@ -693,6 +699,30 @@ std::string DNS::GetResult()
 		return result;
         } else {
 		statsDnsBad++;
+		if (this->fd != -1)
+		{
+			dns_close(this->fd);
+		}
+		return "";
+	}
+}
+
+std::string DNS::GetResultIP()
+{
+	char r[1024];
+	result = dns_getresult(this->fd);
+	if (this->fd != -1)
+	{
+		dns_close(this->fd);
+	}
+	if (result)
+	{
+		sprintf(r,"%d.%d.%d.%d",result[0],result[1],result[2],result[3]);
+		return r;
+	}
+	else
+	{
+		log(DEBUG,"DANGER WILL ROBINSON! NXDOMAIN for forward lookup, but we got a reverse lookup!");
 		return "";
 	}
 }

src/inspircd.cpp

@@ -51,6 +51,7 @@ using namespace std;
 #include <vector>
 #include <deque>
 #include <sched.h>
+#include <pthread.h>
 #include "users.h"
 #include "ctables.h"
 #include "globals.h"
@@ -67,6 +68,7 @@ using namespace std;
 #include "hashcomp.h"
 #include "socketengine.h"
 #include "socket.h"
+#include "dns.h"
 
 int LogLevel = DEFAULT;
 char ServerName[MAXBUF];
@@ -1180,6 +1182,15 @@ void kill_link_silent(userrec *user,const char* r)
 }
 
 
+/*void *task(void *arg)
+{
+	for (;;) { 
+		cout << (char *)arg;
+		cout.flush();
+	}
+	return NULL;
+}*/
+
 int main(int argc, char** argv)
 {
 	Start();
@@ -1206,6 +1217,7 @@ int main(int argc, char** argv)
 			}
 		}
 	}
+
 	strlcpy(MyExecutable,argv[0],MAXBUF);
 	
 	// initialize the lowercase mapping table
@@ -1318,6 +1330,48 @@ void AddWhoWas(userrec* u)
 	}
 }
 
+void* dns_task(void* arg)
+{
+	userrec* u = (userrec*)arg;
+	log(DEBUG,"DNS thread for user %s",u->nick);
+	DNS dns1;
+	DNS dns2;
+	std::string host;
+	std::string ip;
+	if (dns1.ReverseLookup(u->ip))
+	{
+		log(DEBUG,"DNS Step 1");
+		while (!dns1.HasResult())
+		{
+			usleep(100);
+		}
+		host = dns1.GetResult();
+		if (host != "")
+		{
+			log(DEBUG,"DNS Step 2: '%s'",host.c_str());
+			if (dns2.ForwardLookup(host))
+			{
+				while (!dns2.HasResult())
+				{
+					usleep(100);
+				}
+				ip = dns2.GetResultIP();
+				log(DEBUG,"DNS Step 3 '%s'(%d) '%s'(%d)",ip.c_str(),ip.length(),u->ip,strlen(u->ip));
+				if (ip == std::string(u->ip))
+				{
+					log(DEBUG,"DNS Step 4");
+					if (host.length() < 160)
+					{
+						log(DEBUG,"DNS Step 5");
+						strcpy(u->host,host.c_str());
+					}
+				}
+			}
+		}
+	}
+	u->dns_done = true;
+	return NULL;
+}
 
 /* add a client connection to the sockets list */
 void AddClient(int socket, char* host, int port, bool iscached, char* ip)
@@ -1443,6 +1497,12 @@ void AddClient(int socket, char* host, int port, bool iscached, char* ip)
 	}
 	fd_ref_table[socket] = clientlist[tempnick];
 	engine_add_fd;
+
+	// initialize their dns lookup thread
+	//if (pthread_create(&clientlist[tempnick]->dnsthread, NULL, dns_task, (void *)clientlist[tempnick]) != 0)
+	//{
+	//	log(DEBUG,"Failed to create DNS lookup thread for user %s",clientlist[tempnick]->nick);
+	//}
 }
 
 /* shows the message of the day, and any other on-logon stuff */

src/users.cpp

@@ -60,6 +60,11 @@ userrec::userrec()
 	invites.clear();
 }
 
+userrec::~userrec()
+{
+	pthread_kill(this->dnsthread,9);
+}
+
 void userrec::CloseSocket()
 {
 	shutdown(this->fd,2);