fix of flags in errors and very short bufsizes from edns.

git-svn-id: file:///svn/unbound/trunk@397 be551aaa-1e26-0410-a405-d3ace91eadb9

daemon/worker.c

@@ -157,7 +157,7 @@ replyerror_fillbuf(int r, struct comm_reply* repinfo, uint16_t id,
 	
 	ldns_buffer_clear(buf);
 	ldns_buffer_write(buf, &id, sizeof(uint16_t));
-	flags = (uint16_t)(BIT_QR | r); /* QR and retcode*/
+	flags = (uint16_t)(BIT_QR | BIT_RA | r); /* QR and retcode*/
 	flags |= (qflags & (BIT_RD|BIT_CD)); /* copy RD and CD bit */
 	ldns_buffer_write_u16(buf, flags);
 	flags = 1;
@@ -571,6 +571,16 @@ worker_handle_request(struct comm_point* c, void* arg, int error,
 		attach_edns_record(c->buffer, &edns);
 		return 1;
 	}
+	if(edns.edns_present && edns.udp_size < LDNS_HEADER_SIZE) {
+		verbose(VERB_ALGO, "worker request: edns is too small.");
+		LDNS_QR_SET(ldns_buffer_begin(c->buffer));
+		LDNS_TC_SET(ldns_buffer_begin(c->buffer));
+		LDNS_RCODE_SET(ldns_buffer_begin(c->buffer), 
+			LDNS_RCODE_SERVFAIL);
+		ldns_buffer_set_position(c->buffer, LDNS_HEADER_SIZE);
+		ldns_buffer_flip(c->buffer);
+		return 1;
+	}
 	if(c->type != comm_udp)
 		edns.udp_size = 65535; /* max size for TCP replies */
 	if((e=slabhash_lookup(worker->env.msg_cache, h, &qinfo, 0))) {

doc/Changelog

@@ -6,6 +6,9 @@
 	- target-fetch-policy: "3 2 1 0 0" config setting.
 	- fixup queries answered without RD bit (for root prime results).
 	- refuse AXFR and IXFR requests.
+	- fixup RD flag in error reply from iterator. fixup RA flag from
+	  worker error reply.
+	- fixup encoding of very short edns buffer sizes, now sets TC bit.
 
 18 June 2007: Wouter
 	- same, move subqueries to slumber list when first has resolved.

iterator/iterator.c

@@ -255,10 +255,12 @@ error_response(struct module_qstate* qstate, int id, int rcode)
 	verbose(VERB_DETAIL, "return error response %s", 
 		ldns_lookup_by_id(ldns_rcodes, rcode)?
 		ldns_lookup_by_id(ldns_rcodes, rcode)->name:"??");
-	if(iq && iq->orig_qname) {
+	if(iq) {
+		if(iq->orig_qname) {
 			/* encode original query */
 			qstate->qinfo.qname = iq->orig_qname;
 			qstate->qinfo.qname_len = iq->orig_qnamelen;
+		}
 		qstate->query_flags = iq->orig_qflags;
 	}
 	qinfo_query_encode(qstate->buf, &qstate->qinfo);

util/data/msgencode.c

@@ -568,7 +568,26 @@ insert_section(struct reply_info* rep, size_t num_rrsets, uint16_t* num_rrs,
 	return RETVAL_OK;
 }
 
-int reply_info_encode(struct query_info* qinfo, struct reply_info* rep, 
+/** store query section in wireformat buffer, return RETVAL */
+static int
+insert_query(struct query_info* qinfo, struct compress_tree_node* tree, 
+	ldns_buffer* buffer, struct region* region)
+{
+	if(ldns_buffer_remaining(buffer) < 
+		qinfo->qname_len+sizeof(uint16_t)*2)
+		return RETVAL_TRUNC; /* buffer too small */
+	if(!compress_tree_store(&tree, qinfo->qname, 
+		dname_count_labels(qinfo->qname), 
+		ldns_buffer_position(buffer), region, NULL))
+		return RETVAL_OUTMEM;
+	ldns_buffer_write(buffer, qinfo->qname, qinfo->qname_len);
+	ldns_buffer_write_u16(buffer, qinfo->qtype);
+	ldns_buffer_write_u16(buffer, qinfo->qclass);
+	return RETVAL_OK;
+}
+
+int 
+reply_info_encode(struct query_info* qinfo, struct reply_info* rep, 
 	uint16_t id, uint16_t flags, ldns_buffer* buffer, uint32_t timenow, 
 	region_type* region, uint16_t udpsize, int dnssec)
 {
@@ -590,16 +609,17 @@ int reply_info_encode(struct query_info* qinfo, struct reply_info* rep,
 
 	/* insert query section */
 	if(rep->qdcount) {
-		if(ldns_buffer_remaining(buffer) < 
-			qinfo->qname_len+sizeof(uint16_t)*2)
-			return 0; /* buffer too small */
-		if(!compress_tree_store(&tree, qinfo->qname, 
-			dname_count_labels(qinfo->qname), 
-			ldns_buffer_position(buffer), region, NULL))
+		if((r=insert_query(qinfo, tree, buffer, region)) != 
+			RETVAL_OK) {
+			if(r == RETVAL_TRUNC) {
+				/* create truncated message */
+				ldns_buffer_write_u16_at(buffer, 4, 0);
+				LDNS_TC_SET(ldns_buffer_begin(buffer));
+				ldns_buffer_flip(buffer);
+				return 1;
+			}
 			return 0;
-		ldns_buffer_write(buffer, qinfo->qname, qinfo->qname_len);
-		ldns_buffer_write_u16(buffer, qinfo->qtype);
-		ldns_buffer_write_u16(buffer, qinfo->qclass);
+		}
 	}
 
 	/* insert answer section */
@@ -689,6 +709,7 @@ reply_info_answer_encode(struct query_info* qinf, struct reply_info* rep,
 	struct edns_data* edns, int dnssec)
 {
 	uint16_t flags;
+	int attach_edns = 1;
 
 	if(!cached) {
 		/* original flags, copy RD bit from query. */
@@ -698,14 +719,22 @@ reply_info_answer_encode(struct query_info* qinf, struct reply_info* rep,
 		flags = (rep->flags & ~BIT_AA) | (qflags & (BIT_RD|BIT_CD)); 
 	}
 	log_assert(flags & BIT_QR); /* QR bit must be on in our replies */
-	if(udpsize < LDNS_HEADER_SIZE + calc_edns_field_size(edns))
-		return 0; /* packet too small to contain edns... */
+	if(udpsize < LDNS_HEADER_SIZE)
+		return 0;
+	if(udpsize < LDNS_HEADER_SIZE + calc_edns_field_size(edns)) {
+		/* packet too small to contain edns, omit it. */
+		attach_edns = 0;
+	} else {
+		/* reserve space for edns record */
 		udpsize -= calc_edns_field_size(edns);
+	}
+
 	if(!reply_info_encode(qinf, rep, id, flags, pkt, timenow, region,
 		udpsize, dnssec)) {
 		log_err("reply encode: out of memory");
 		return 0;
 	}
+	if(attach_edns)
 		attach_edns_record(pkt, edns);
 	return 1;
 }