Functioning DNS udp forwarding.

git-svn-id: file:///svn/unbound/trunk@59 be551aaa-1e26-0410-a405-d3ace91eadb9

daemon/worker.c

@@ -54,13 +54,47 @@
 
 /** timeout in seconds for UDP queries to auth servers. TODO: proper rtt */
 #define UDP_QUERY_TIMEOUT 5
+/** the size of ID and flags, opcode, rcode in dns packet */
+#define ID_AND_FLAGS 4
+
+/** reply to query with given error code */
+static void replyerror(int r, struct worker* worker)
+{
+	LDNS_QR_SET(ldns_buffer_begin(worker->query_reply.c->buffer));
+	LDNS_RCODE_SET(ldns_buffer_begin(worker->query_reply.c->buffer), r);
+	comm_point_send_reply(&worker->query_reply);
+	worker->num_requests --;
+}
+
+/** process incoming replies from the network */
+static int worker_handle_reply(struct comm_point* c, void* arg, int error, 
+	struct comm_reply* ATTR_UNUSED(reply_info))
+{
+	struct worker* worker = (struct worker*)arg;
+	if(error != 0) {
+		replyerror(LDNS_RCODE_SERVFAIL, worker);
+		return 0;
+	}
+	/* woohoo a reply! */
+	ldns_buffer_clear(worker->query_reply.c->buffer);
+	ldns_buffer_skip(worker->query_reply.c->buffer, ID_AND_FLAGS);
+	ldns_buffer_write(worker->query_reply.c->buffer, 
+		ldns_buffer_at(c->buffer, ID_AND_FLAGS), 
+		ldns_buffer_limit(c->buffer) - ID_AND_FLAGS);
+	LDNS_QR_SET(ldns_buffer_begin(worker->query_reply.c->buffer));
+	ldns_buffer_flip(worker->query_reply.c->buffer);
+	comm_point_send_reply(&worker->query_reply);
+	worker->num_requests --;
+	return 0;
+}
 
 /** process incoming request */
 static void worker_process_query(struct worker* worker) 
 {
 	/* query the forwarding address */
 	pending_udp_query(worker->back, worker->query_reply.c->buffer, 
-		&worker->fwd_addr, worker->fwd_addrlen, UDP_QUERY_TIMEOUT);
+		&worker->fwd_addr, worker->fwd_addrlen, UDP_QUERY_TIMEOUT,
+		worker_handle_reply, worker);
 }
 
 /** check request sanity. Returns error code, 0 OK, or -1 discard. 
@@ -117,6 +151,7 @@ static int worker_handle_request(struct comm_point* c, void* arg, int error,
 	}
 	if((ret=worker_check_request(c->buffer)) != 0) {
 		if(ret != -1) {
+			LDNS_QR_SET(ldns_buffer_begin(c->buffer));
 			LDNS_RCODE_SET(ldns_buffer_begin(c->buffer), ret);
 			return 1;
 		}

doc/Changelog

@@ -5,6 +5,7 @@
 	- listens on both ip4 and ip6 ports to provide correct return address.
 	- worker fwder address filled correctly.
 	- fixup timer code.
+	- forwards udp queries and sends answer.
 
 1 February 2007: Wouter
 	- outside network more UDP work.

services/outside_network.c

@@ -106,9 +106,8 @@ static int outnet_udp_cb(struct comm_point* c, void* arg, int error,
 		return 0;
 	}
 	comm_timer_disable(p->timer);
-	/* TODO handle it */
 	log_info("outnet handle udp reply");
-
+	(void)(*p->cb)(p->c, p->cb_arg, 0, NULL);
 	return 0;
 }
 
@@ -225,9 +224,10 @@ static void calc_num46(const char** ifs, int num_ifs,
 /** callback for udp timeout */
 static void pending_udp_timer_cb(void *arg)
 {
-	/* struct pending* p = (struct pending*)arg; */
-	/* it timed out . TODO handle it. */
+	struct pending* p = (struct pending*)arg;
+	/* it timed out */
 	log_info("timeout udp");
+	(void)(*p->cb)(p->c, p->cb_arg, -2, NULL);
 }
 
 struct outside_network* 
@@ -344,7 +344,8 @@ void pending_delete(struct outside_network* outnet, struct pending* p)
 /** create a new pending item with given characteristics, false on failure */
 static struct pending*
 new_pending(struct outside_network* outnet, ldns_buffer* packet, 
-	struct sockaddr_storage* addr, socklen_t addrlen)
+	struct sockaddr_storage* addr, socklen_t addrlen,
+	comm_point_callback_t* callback, void* callback_arg)
 {
 	/* alloc */
 	int id_tries = 0;
@@ -364,6 +365,8 @@ new_pending(struct outside_network* outnet, ldns_buffer* packet,
 	pend->id = LDNS_ID_WIRE(ldns_buffer_begin(packet));
 	memcpy(&pend->addr, addr, addrlen);
 	pend->addrlen = addrlen;
+	pend->cb = callback;
+	pend->cb_arg = callback_arg;
 
 	/* insert in tree */
 	pend->node.key = pend;
@@ -436,14 +439,16 @@ static void select_port(struct outside_network* outnet, struct pending* pend)
 
 
 void pending_udp_query(struct outside_network* outnet, ldns_buffer* packet, 
-	struct sockaddr_storage* addr, socklen_t addrlen, int timeout)
+	struct sockaddr_storage* addr, socklen_t addrlen, int timeout,
+	comm_point_callback_t* cb, void* cb_arg)
 {
 	struct pending* pend;
 	struct timeval tv;
 
 	/* create pending struct (and possibly change ID to be unique) */
-	if(!(pend=new_pending(outnet, packet, addr, addrlen))) {
+	if(!(pend=new_pending(outnet, packet, addr, addrlen, cb, cb_arg))) {
 		/* callback user for the error */
+		(void)(*cb)(NULL, cb_arg, -1, NULL);
 		return;
 	}
 	select_port(outnet, pend);
@@ -454,6 +459,7 @@ void pending_udp_query(struct outside_network* outnet, ldns_buffer* packet,
 		/* error, call error callback function */
 		pending_delete(outnet, pend);
 		/* callback user for the error */
+		(void)(*pend->cb)(pend->c, pend->cb_arg, -1, NULL);
 		return;
 	}
 

services/outside_network.h

@@ -45,10 +45,9 @@
 
 #include "config.h"
 #include "util/rbtree.h"
+#include "util/netevent.h"
 struct pending;
 struct pending_timeout;
-struct comm_point;
-struct comm_base;
 
 /**
  * Send queries to outside servers and wait for answers from servers.
@@ -97,6 +96,10 @@ struct pending {
 	struct comm_point* c;
 	/** timeout event */
 	struct comm_timer* timer;
+	/** callback for the timeout, error or reply to the message */
+	comm_point_callback_t* cb;
+	/** callback user argument */
+	void* cb_arg;
 };
 
 /**
@@ -129,9 +132,12 @@ void outside_network_delete(struct outside_network* outnet);
  * @param addr: address to send to.
  * @param addrlen: length of addr.
  * @param timeout: in seconds from now.
+ * @param callback: function to call on error, timeout or reply.
+ * @param callback_arg: user argument for callback function.
  */
 void pending_udp_query(struct outside_network* outnet, ldns_buffer* packet, 
-	struct sockaddr_storage* addr, socklen_t addrlen, int timeout);
+	struct sockaddr_storage* addr, socklen_t addrlen, int timeout,
+	comm_point_callback_t* callback, void* callback_arg);
 
 /**
  * Delete pending answer.