cname handling improved.

git-svn-id: file:///svn/unbound/trunk@815 be551aaa-1e26-0410-a405-d3ace91eadb9

doc/Changelog

@@ -1,6 +1,7 @@
 7 December 2007: Wouter
 	- unbound-host has a -d option to show what happens. This can help
 	  with debugging (why do I get this answer).
+	- fixup CNAME handling, on nodata, sets and display canonname.
 
 6 December 2007: Wouter
 	- library resolution works in foreground mode, unbound-host app

libunbound/worker.c

@@ -58,6 +58,7 @@
 #include "util/storage/slabhash.h"
 #include "util/net_help.h"
 #include "util/data/dname.h"
+#include "util/data/msgreply.h"
 
 /** size of table used for random numbers. large to be more secure. */
 #define RND_STATE_SIZE 256
@@ -206,24 +207,35 @@ parse_reply(ldns_buffer* pkt, struct regional* region, struct query_info* qi)
 	return rep;
 }
 
+/** insert canonname */
+static int
+fill_canon(struct ub_val_result* res, uint8_t* s)
+{
+	char buf[255+2];
+	dname_str(s, buf);
+	res->canonname = strdup(buf);
+	return res->canonname != 0;
+}
+
 /** fill data into result */
 static int
 fill_res(struct ub_val_result* res, struct ub_packed_rrset_key* answer,
-	struct query_info* rq)
+	uint8_t* finalcname, struct query_info* rq)
 {
 	size_t i;
 	struct packed_rrset_data* data;
 	if(!answer) {
+		if(finalcname) {
+			if(!fill_canon(res, finalcname))
+				return 0; /* out of memory */
+		}
 		res->data = calloc(1, sizeof(char*));
 		res->len = calloc(1, sizeof(size_t));
 		return (res->data && res->len);
 	}
 	data = (struct packed_rrset_data*)answer->entry.data;
 	if(query_dname_compare(rq->qname, answer->rk.dname) != 0) {
-		char buf[255+2];
-		dname_str(answer->rk.dname, buf);
-		res->canonname = strdup(buf);
-		if(!res->canonname)
+		if(!fill_canon(res, answer->rk.dname))
 			return 0; /* out of memory */
 	} else
 		res->canonname = res->qname;
@@ -272,8 +284,8 @@ libworker_fg_done_cb(void* arg, int rcode, ldns_buffer* buf, enum sec_status s)
 	if(!rep) {
 		return; /* error parsing buf, or out of memory */
 	}
-	/* log_dns_msg("fg reply", &rq, rep); @@@ DEBUG */
-	if(!fill_res(d->q->res, reply_find_answer_rrset(&rq, rep), &rq))
+	if(!fill_res(d->q->res, reply_find_answer_rrset(&rq, rep), 
+		reply_find_final_cname_target(&rq, rep), &rq))
 		return; /* out of memory */
 	/* rcode, nxdomain, bogus */
 	d->q->res->rcode = (int)LDNS_RCODE_WIRE(d->q->msg);

smallapp/unbound-host.c

@@ -288,12 +288,16 @@ pretty_output(char* q, int t, int c, int sec, int haved,
 		return;
 	}
 	if(docname && result->canonname &&
-		result->canonname != result->qname)
-		printf("%s is an alias for %s\n", result->qname, 
+		result->canonname != result->qname) {
+		printf("%s is an alias for %s", result->qname, 
 			result->canonname);
+		if(verb > 0)
+			printf(" %s", secstatus);
+		printf("\n");
+	}
 	if(!haved) {
 		if(verb > 0) {
-			printf("%s", q);
+			printf("%s", result->canonname?result->canonname:q);
 			if(strcmp(cstr, "IN") != 0)
 				printf(" in class %s", cstr);
 			if(t == LDNS_RR_TYPE_A)

util/data/msgreply.c

@@ -648,6 +648,27 @@ reply_info_copy(struct reply_info* rep, struct alloc_cache* alloc,
 	return cp;
 }
 
+uint8_t* 
+reply_find_final_cname_target(struct query_info* qinfo, struct reply_info* rep)
+{
+	uint8_t* sname = qinfo->qname;
+	size_t snamelen = qinfo->qname_len;
+	size_t i;
+	for(i=0; i<rep->an_numrrsets; i++) {
+		struct ub_packed_rrset_key* s = rep->rrsets[i];
+		/* follow CNAME chain (if any) */
+		if(ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME && 
+			ntohs(s->rk.rrset_class) == qinfo->qclass && 
+			snamelen == s->rk.dname_len &&
+			query_dname_compare(sname, s->rk.dname) == 0) {
+			get_cname_target(s, &sname, &snamelen);
+		}
+	}
+	if(sname != qinfo->qname)
+		return sname;
+	return NULL;
+}
+
 struct ub_packed_rrset_key* 
 reply_find_answer_rrset(struct query_info* qinfo, struct reply_info* rep)
 {

util/data/msgreply.h

@@ -315,6 +315,15 @@ int parse_copy_decompress_rrset(ldns_buffer* pkt, struct msg_parse* msg,
 	struct rrset_parse *pset, struct regional* region, 
 	struct ub_packed_rrset_key* pk);
 
+/**
+ * Find final cname target in reply, the one matching qinfo. Follows CNAMEs.
+ * @param qinfo: what to start with.
+ * @param rep: looks in answer section of this message.
+ * @return: pointer dname, or NULL if not found.
+ */
+uint8_t* reply_find_final_cname_target(struct query_info* qinfo,
+	struct reply_info* rep);
+
 /**
  * Find answer rrset in reply, the one matching qinfo. Follows CNAMEs, so the
  * result may have a different owner name.