X-Git-Url: https://git.netwichtig.de/gitweb/?a=blobdiff_plain;f=src%2Fdns.cpp;h=a6e41307170d513938cba0f29795373935c5a97c;hb=57bba0c632bf07cdce7810330dffdfa27ae14972;hp=dc25fe8fee417c6d0be5be4837369ef077f1bc23;hpb=3a7fa1660c3d78f1f80f3502a8dae77642d3c3f9;p=user%2Fhenk%2Fcode%2Finspircd.git

diff --git a/src/dns.cpp b/src/dns.cpp
index dc25fe8fe..a6e413071 100644
--- a/src/dns.cpp
+++ b/src/dns.cpp
@@ -49,11 +49,18 @@ using namespace std;
 #include "dns.h"
 #include "inspircd.h"
 #include "helperfuncs.h"
+#include "inspircd_config.h"
 #include "socketengine.h"
+#include "configreader.h"
+
+#ifdef THREADED_DNS
+pthread_mutex_t connmap_lock = PTHREAD_MUTEX_INITIALIZER;
+#endif
 
 extern InspIRCd* ServerInstance;
 extern ServerConfig* Config;
 extern time_t TIME;
+extern userrec* fd_ref_table[MAX_DESCRIPTORS];
 
 enum QueryType { DNS_QRY_A = 1, DNS_QRY_PTR = 12 };
 enum QueryFlags1 { FLAGS1_MASK_RD = 0x01, FLAGS1_MASK_TC = 0x02, FLAGS1_MASK_AA = 0x04, FLAGS1_MASK_OPCODE = 0x78, FLAGS1_MASK_QR = 0x80 };
@@ -65,10 +72,11 @@ typedef std::map<int,s_connection*> connlist;
 typedef connlist::iterator connlist_iter;
 connlist connections;
 
+Resolver* dns_classes[MAX_DESCRIPTORS];
+
 struct in_addr servers4[8];
 int i4;
 int initdone = 0;
-int wantclose = 0;
 int lastcreate = -1;
 
 class s_connection
@@ -166,11 +174,6 @@ void dns_close(int fd)
 		ServerInstance->SE->DelFd(fd);
 #endif
 	log(DEBUG,"DNS: dns_close on fd %d",fd);
-	if (fd == lastcreate)
-	{
-		wantclose = 1;
-		return;
-	}
 	shutdown(fd,2);
 	close(fd);
 	return;
@@ -210,12 +213,12 @@ void DNS::dns_init()
 
 void DNS::dns_init_2(const char* dnsserver)
 {
-        in_addr addr4;
-        i4 = 0;
-        srand((unsigned int) TIME);
-        memset(servers4,'\0',sizeof(in_addr) * 8);
-        if (dns_aton4_s(dnsserver,&addr4) != NULL)
-            memcpy(&servers4[i4++],&addr4,sizeof(in_addr));
+	in_addr addr4;
+	i4 = 0;
+	srand((unsigned int) TIME);
+	memset(servers4,'\0',sizeof(in_addr) * 8);
+	if (dns_aton4_s(dnsserver,&addr4) != NULL)
+	    memcpy(&servers4[i4++],&addr4,sizeof(in_addr));
 }
 
 
@@ -285,20 +288,19 @@ s_connection *dns_add_query(s_header *h)
 	}
 	if (s->fd == -1)
 	{
-		delete s;
+		DELETE(s);
 		return NULL;
 	}
 	/* create new connection object, add to linked list */
+#ifdef THREADED_DNS
+	pthread_mutex_lock(&connmap_lock);
+#endif
 	if (connections.find(s->fd) == connections.end())
 		connections[s->fd] = s;
+#ifdef THREADED_DNS
+	pthread_mutex_unlock(&connmap_lock);
+#endif
 
-	if (wantclose == 1)
-	{
-		shutdown(lastcreate,2);
-		close(lastcreate);
-		wantclose = 0;
-	}
-	lastcreate = s->fd;
 	return s;
 }
 
@@ -352,7 +354,7 @@ in_addr* DNS::dns_aton4_r(const char *ipstring) { /* ascii to numeric (reentrant
 	ip = new in_addr;
 	if(dns_aton4_s(ipstring,ip) == NULL)
 	{
-		delete ip;
+		DELETE(ip);
 		return NULL;
 	}
 	return ip;
@@ -461,6 +463,14 @@ char* DNS::dns_getresult_s(const int cfd, char *res) { /* retrieve result of DNS
 		*res = 0;
 
 	/* FireDNS used a linked list for this. How ugly (and slow). */
+
+#ifdef THREADED_DNS
+	/* XXX: STL really does NOT like being poked and prodded in more than
+	 * one orifice by threaded apps. Make sure we remain nice to it, and
+	 * lock a mutex around any access to the std::map.
+	 */
+	pthread_mutex_lock(&connmap_lock);
+#endif
 	connlist_iter n_iter = connections.find(cfd);
 	if (n_iter == connections.end())
 	{
@@ -474,43 +484,46 @@ char* DNS::dns_getresult_s(const int cfd, char *res) { /* retrieve result of DNS
 		/* We don't delete c here, because its done later when needed */
 		connections.erase(n_iter);
 	}
+#ifdef THREADED_DNS
+	pthread_mutex_unlock(&connmap_lock);
+#endif
 
 	l = recv(c->fd,buffer,sizeof(s_header),0);
 	dns_close(c->fd);
 	if (l < 12)
 	{
-		delete c;
+		DELETE(c);
 		return NULL;
 	}
 	dns_fill_header(&h,buffer,l - 12);
 	if (c->id[0] != h.id[0] || c->id[1] != h.id[1])
 	{
 		log(DEBUG,"DNS: id mismatch on query");
-		delete c;
+		DELETE(c);
 		return NULL; /* ID mismatch */
 	}
 	if ((h.flags1 & FLAGS1_MASK_QR) == 0)
 	{
 		log(DEBUG,"DNS: didnt get a query result");
-		delete c;
+		DELETE(c);
 		return NULL;
 	}
 	if ((h.flags1 & FLAGS1_MASK_OPCODE) != 0)
 	{
 		log(DEBUG,"DNS: got an OPCODE and didnt want one");
-		delete c;
+		DELETE(c);
 		return NULL;
 	}
 	if ((h.flags2 & FLAGS2_MASK_RCODE) != 0)
 	{
 		log(DEBUG,"DNS lookup failed due to SERVFAIL");
-		delete c;
+		DELETE(c);
 		return NULL;
 	}
 	if (h.ancount < 1)
 	{
 		log(DEBUG,"DNS: no answers!");
-		delete c;
+		DELETE(c);
 		return NULL;
 	}
 	i = 0;
@@ -556,7 +569,7 @@ char* DNS::dns_getresult_s(const int cfd, char *res) { /* retrieve result of DNS
 		}
 		if (l - i < 10)
 		{
-			delete c;
+			DELETE(c);
 			return NULL;
 		}
 		dns_fill_rr(&rr,&h.payload[i]);
@@ -592,6 +605,7 @@ char* DNS::dns_getresult_s(const int cfd, char *res) { /* retrieve result of DNS
 			{
 				if (h.payload[i] > 63)
 				{
+					log(DEBUG,"DNS: h.payload[i] > 63");
 					memcpy(&p,&h.payload[i],2);
 					i = ntohs(p) - 0xC000 - 12;
 				}
@@ -627,7 +641,7 @@ char* DNS::dns_getresult_s(const int cfd, char *res) { /* retrieve result of DNS
 						break;
 					if (rr.rdlength != 4)
 					{
-						delete c;
+						DELETE(c);
 						return NULL;
 					}
 					memcpy(&alist->ip,&h.payload[i],4);
@@ -654,7 +668,7 @@ char* DNS::dns_getresult_s(const int cfd, char *res) { /* retrieve result of DNS
 					}
 					if (l - i < 10)
 					{
-						delete c;
+						DELETE(c);
 						return NULL;
 					}
 					dns_fill_rr(&rr,&h.payload[i]);
@@ -674,7 +688,7 @@ char* DNS::dns_getresult_s(const int cfd, char *res) { /* retrieve result of DNS
 			res[rr.rdlength] = '\0';
 			break;
 	}
-	delete c;
+	DELETE(c);
 	return res;
 }
 
@@ -700,30 +714,33 @@ DNS::~DNS()
 {
 }
 
-bool DNS::ReverseLookup(const std::string &ip)
+bool DNS::ReverseLookup(const std::string &ip, bool ins)
 {
 	if (ServerInstance && ServerInstance->stats)
 		ServerInstance->stats->statsDns++;
-        binip = dns_aton4(ip.c_str());
-        if (binip == NULL)
+	binip = dns_aton4(ip.c_str());
+	if (binip == NULL)
 	{
-                return false;
-        }
+		return false;
+	}
 
-        this->myfd = dns_getname4(binip);
+	this->myfd = dns_getname4(binip);
 	if (this->myfd == -1)
 	{
 		return false;
 	}
 	log(DEBUG,"DNS: ReverseLookup, fd=%d",this->myfd);
 #ifndef THREADED_DNS
-	if (ServerInstance && ServerInstance->SE)
-		ServerInstance->SE->AddFd(this->myfd,true,X_ESTAB_DNS);
+	if (ins)
+	{
+		if (ServerInstance && ServerInstance->SE)
+			ServerInstance->SE->AddFd(this->myfd,true,X_ESTAB_DNS);
+	}
 #endif
 	return true;
 }
 
-bool DNS::ForwardLookup(const std::string &host)
+bool DNS::ForwardLookup(const std::string &host, bool ins)
 {
 	if (ServerInstance && ServerInstance->stats)
 		ServerInstance->stats->statsDns++;
@@ -734,8 +751,11 @@ bool DNS::ForwardLookup(const std::string &host)
 	}
 	log(DEBUG,"DNS: ForwardLookup, fd=%d",this->myfd);
 #ifndef THREADED_DNS
-	if (ServerInstance && ServerInstance->SE)
-		ServerInstance->SE->AddFd(this->myfd,true,X_ESTAB_DNS);
+	if (ins)
+	{
+		if (ServerInstance && ServerInstance->SE)
+			ServerInstance->SE->AddFd(this->myfd,true,X_ESTAB_DNS);
+	}
 #endif
 	return true;
 }
@@ -748,7 +768,7 @@ bool DNS::ForwardLookupWithFD(const std::string &host, int &fd)
 	fd = this->myfd;
 	if (this->myfd == -1)
 	{
-		
+		return false;
 	}
 	log(DEBUG,"DNS: ForwardLookupWithFD, fd=%d",this->myfd);
 	if (ServerInstance && ServerInstance->SE)
@@ -784,14 +804,15 @@ int DNS::GetFD()
 std::string DNS::GetResult()
 {
 	log(DEBUG,"DNS: GetResult()");
-        result = dns_getresult(this->myfd);
-        if (result)
+	result = dns_getresult(this->myfd);
+	if (result)
 	{
 		if (ServerInstance && ServerInstance->stats)
 			ServerInstance->stats->statsDnsGood++;
 		dns_close(this->myfd);
+		this->myfd = -1;
 		return result;
-        }
+	}
 	else
 	{
 		if (ServerInstance && ServerInstance->stats)
@@ -799,6 +820,7 @@ std::string DNS::GetResult()
 		if (this->myfd != -1)
 		{
 			dns_close(this->myfd);
+			this->myfd = -1;
 		}
 		return "";
 	}
@@ -812,6 +834,7 @@ std::string DNS::GetResultIP()
 	if (this->myfd != -1)
 	{
 		dns_close(this->myfd);
+		this->myfd = -1;
 	}
 	if (result)
 	{
@@ -836,42 +859,192 @@ std::string DNS::GetResultIP()
 
 
 #ifdef THREADED_DNS
+
+/* This function is a thread function which can be thought of as a lightweight process
+ * to all you non-threaded people. In actuality its so much more, and pretty damn cool.
+ * With threaded dns enabled, each user which connects gets a thread attached to their
+ * user record when their DNS lookup starts. This function starts in parallel, and
+ * commences a blocking dns lookup. Because its a seperate thread, this occurs without
+ * actually blocking the main application. Once the dns lookup is completed, the thread
+ * checks if the user is still around by checking their fd against the reference table,
+ * and if they are, writes the hostname into the struct and terminates, after setting
+ * userrec::dns_done to true. Because this is multi-threaded it can make proper use of
+ * SMP setups (like the one i have here *grin*).
+ * This is in comparison to the non-threaded dns, which must monitor the thread sockets
+ * in a nonblocking fashion, consuming more resources to do so.
+ */
 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((char*)inet_ntoa(u->ip4)))
-        {
-                while (!dns1.HasResult())
-                {
-                        usleep(100);
-                }
-                host = dns1.GetResult();
-                if (host != "")
-                {
-                        if (dns2.ForwardLookup(host))
-                        {
-                                while (!dns2.HasResult())
-                                {
-                                        usleep(100);
-                                }
-                                ip = dns2.GetResultIP();
-                                if (ip == std::string((char*)inet_ntoa(u->ip4)))
-                                {
-                                        if (host.length() < 160)
-                                        {
-                                                strcpy(u->host,host.c_str());
-                                                strcpy(u->dhost,host.c_str());
-                                        }
-                                }
-                        }
-                }
-        }
-        u->dns_done = true;
-        return NULL;
+	userrec* u = (userrec*)arg;
+	int thisfd = u->fd;
+
+	log(DEBUG,"DNS thread for user %s",u->nick);
+	DNS dns1;
+	DNS dns2;
+	std::string host;
+	std::string ip;
+	if (dns1.ReverseLookup(inet_ntoa(u->ip4),false))
+	{
+		while (!dns1.HasResult())
+			usleep(100);
+		host = dns1.GetResult();
+		if (host != "")
+		{
+			if (dns2.ForwardLookup(host, false))
+			{
+				while (!dns2.HasResult())
+					usleep(100);
+				ip = dns2.GetResultIP();
+				if (ip == std::string(inet_ntoa(u->ip4)))
+				{
+					if (host.length() < 65)
+					{
+						if ((fd_ref_table[thisfd] == u) && (fd_ref_table[thisfd]))
+						{
+							if (!u->dns_done)
+							{
+								strcpy(u->host,host.c_str());
+								if ((fd_ref_table[thisfd] == u) && (fd_ref_table[thisfd]))
+								{
+									strcpy(u->dhost,host.c_str());
+								}
+							}
+						}
+					}
+				}
+			}
+		}
+	}
+	if ((fd_ref_table[thisfd] == u) && (fd_ref_table[thisfd]))
+		u->dns_done = true;
+	return NULL;
 }
 #endif
+
+Resolver::Resolver(const std::string &source, bool forward, const std::string &dnsserver = "") : input(source), fwd(forward), server(dnsserver)
+{
+	if (this->server != "")
+		Query.SetNS(this->server);
+	else
+		Query.SetNS(Config->DNSServer);
+
+	if (forward)
+	{
+		Query.ForwardLookup(input.c_str(), false);
+		this->fd = Query.GetFD();
+	}
+	else
+	{
+		Query.ReverseLookup(input.c_str(), false);
+		this->fd = Query.GetFD();
+	}
+	if (fd < 0)
+	{
+		log(DEBUG,"Resolver::Resolver: RESOLVER_NSDOWN");
+		this->OnError(RESOLVER_NSDOWN);
+		ModuleException e("Resolver: Nameserver is down");
+		throw e;
+		/* We shouldnt get here really */
+		return;
+	}
+
+	if (ServerInstance && ServerInstance->SE)
+	{
+		log(DEBUG,"Resolver::Resolver: this->fd=%d",this->fd);
+		ServerInstance->SE->AddFd(this->fd,true,X_ESTAB_CLASSDNS);
+	}
+	else
+	{
+		log(DEBUG,"Resolver::Resolver: RESOLVER_NOTREADY");
+		this->OnError(RESOLVER_NOTREADY);
+		ModuleException e("Resolver: Core not initialized yet");
+		throw e;
+		/* We shouldnt get here really */
+		return;
+	}
+}
+
+Resolver::~Resolver()
+{
+	log(DEBUG,"Resolver::~Resolver");
+	if (ServerInstance && ServerInstance->SE)
+		ServerInstance->SE->DelFd(this->fd);
+}
+
+int Resolver::GetFd()
+{
+	return this->fd;
+}
+
+bool Resolver::ProcessResult()
+{
+	log(DEBUG,"Resolver::ProcessResult");
+	if (this->fwd)
+		result = Query.GetResultIP();
+	else
+		result = Query.GetResult();
+
+	if (result != "")
+	{
+		log(DEBUG,"Resolver::OnLookupComplete(%s)",result.c_str());
+		this->OnLookupComplete(result);
+		return true;
+	}
+	else
+	{
+		log(DEBUG,"Resolver::OnError(RESOLVER_NXDOMAIN)");
+		this->OnError(RESOLVER_NXDOMAIN);
+		return false;
+	}
+}
+
+void Resolver::OnLookupComplete(const std::string &result)
+{
+}
+
+void Resolver::OnError(ResolverError e)
+{
+}
+
+void dns_deal_with_classes(int fd)
+{
+	log(DEBUG,"dns_deal_with_classes(%d)",fd);
+	if ((fd > -1) && (dns_classes[fd]))
+	{
+		log(DEBUG,"Valid fd %d",fd);
+		dns_classes[fd]->ProcessResult();
+		delete dns_classes[fd];
+		dns_classes[fd] = NULL;
+	}
+}
+
+bool dns_add_class(Resolver* r)
+{
+	log(DEBUG,"dns_add_class");
+	if ((r) && (r->GetFd() > -1))
+	{
+		if (!dns_classes[r->GetFd()])
+		{
+			log(DEBUG,"dns_add_class: added class");
+			dns_classes[r->GetFd()] = r;
+			return true;
+		}
+		else
+		{
+			log(DEBUG,"Space occupied!");
+			return false;
+		}
+	}
+	else
+	{
+		log(DEBUG,"Bad class");
+		delete r;
+		return true;
+	}
+}
+
+void init_dns()
+{
+	memset(dns_classes,0,sizeof(dns_classes));
+}
+