Tests for compression, and decompression in query section fix.

git-svn-id: file:///svn/unbound/trunk@270 be551aaa-1e26-0410-a405-d3ace91eadb9

doc/Changelog

@@ -1,3 +1,8 @@
+1 May 2007: Wouter
+	- decompress query section, extremely lenient acceptance.
+	  But only for answers from other servers, not for plain queries.
+	- compression and decompression test cases.
+
 27 April 2007: Wouter
 	- removed iov usage, it is not good for dns message encoding.
 	- owner name compression more optimal.

testcode/unitmsgparse.c

@@ -255,7 +255,9 @@ testpkt(ldns_buffer* pkt, struct alloc_cache* alloc, ldns_buffer* out,
 
 	hex_to_buf(pkt, hex);
 	memmove(&id, ldns_buffer_begin(pkt), sizeof(id));
-	memmove(&flags, ldns_buffer_at(pkt, 2), sizeof(flags));
+	if(ldns_buffer_limit(pkt) < 2)
+		flags = 0;
+	else	memmove(&flags, ldns_buffer_at(pkt, 2), sizeof(flags));
 	flags = ntohs(flags);
 	ret = reply_info_parse(pkt, alloc, &qi, &rep);
 	if(ret != 0) {
@@ -366,6 +368,7 @@ testfromdrillfile(ldns_buffer* pkt, struct alloc_cache* alloc,
 	FILE* in = fopen(fname, "r");
 	char buf[102400];
 	char* np = buf;
+	buf[0]=0;
 	if(!in) {
 		perror("fname");
 		return;
@@ -378,6 +381,7 @@ testfromdrillfile(ldns_buffer* pkt, struct alloc_cache* alloc,
 				testpkt(pkt, alloc, out, buf);
 			/* set for new entry */
 			np = buf;
+			buf[0]=0;
 			continue;
 		}
 		if(np[0] == ';') /* comment */
@@ -405,6 +409,7 @@ void msgparse_test()
 	testfromfile(pkt, &alloc, out, "testdata/test_packets.3");
 	/* like from drill -w - */
 	testfromdrillfile(pkt, &alloc, out, "testdata/test_packets.4");
+	testfromdrillfile(pkt, &alloc, out, "testdata/test_packets.5");
 
 	/* cleanup */
 	alloc_clear(&alloc);

testdata/test_packets.5

@@ -0,0 +1,56 @@
+; Hand made test packets.
+; By Wouter Wijngaards.
+; These DNS packets contain interesting compression cases.
+; 
+;-- next packet --
+; 0. A valid packet (handmade)
+; id flags qd  an   ns  ar   -- header
+4242 0000 0001 0001 0000 0000
+; query: qname example.com. qtype A(1) qclass IN(1)
+07 6578616d706c65 03 636f6d 00 0001 0001
+; answer: example.com          type class ttl rdatalen 10.x address.
+07 6578616d706c65 03 636f6d 00 0001 0001  00000101 0004 0a203040
+
+;-- next packet --
+; 0b. correct compression from answer to query.
+4242 0000 0001 0001 0000 0000
+07 6578616d706c65 03 636f6d 00 0001 0001
+c00c 0001 0001  00000101 0004 0a203040
+
+;-- next packet --
+; 1. Compression from query to answer.
+4242 0000 0001 0001 0000 0000
+c012 0001 0001
+07 6578616d706c65 03 636f6d 00 0001 0001  00000101 0004 0a203040
+
+;-- next packet --
+; 2. Compression loop answer 1 to answer 2.
+4242 0000 0001 0002 0000 0000
+07 6578616d706c65 03 636f6d 00 0001 0001
+c02d 0001 0001  00000101 0004 0a203040
+07 6578616d706c65 03 636f6d 00 0001 0001  00000101 0004 0a203050
+
+;-- next packet --
+; 2b. Compression loop answer 2 to answer 1.
+4242 0000 0001 0002 0000 0000
+07 6578616d706c65 03 636f6d 00 0001 0001
+07 6578616d706c65 03 636f6d 00 0001 0001  00000101 0004 0a203050
+c01d 0001 0001  00000101 0004 0a203040
+
+;-- next packet --
+; 3. Compression loop to self (in answer section).
+4242 0000 0001 0001 0000 0000
+07 6578616d706c65 03 636f6d 00 0001 0001
+c01d 0001 0001  00000101 0004 0a203040
+
+;-- next packet --
+; 4. bad compression pointer - to header.
+4242 0000 0001 0001 0000 0000
+07 6578616d706c65 03 636f6d 00 0001 0001
+c004 0001 0001  00000101 0004 0a203040
+
+;-- next packet --
+; 5. bad compression pointer - exceeds packet.
+4242 0000 0001 0001 0000 0000
+07 6578616d706c65 03 636f6d 00 0001 0001
+c0bb 0001 0001  00000101 0004 0a203040

util/data/msgparse.c

@@ -528,7 +528,7 @@ parse_query_section(ldns_buffer* pkt, struct msg_parse* msg)
 	if(ldns_buffer_remaining(pkt) <= 0)
 		return LDNS_RCODE_FORMERR;
 	msg->qname = ldns_buffer_current(pkt);
-	if((msg->qname_len = query_dname_len(pkt)) == 0)
+	if((msg->qname_len = pkt_dname_len(pkt)) == 0)
 		return LDNS_RCODE_FORMERR;
 	if(ldns_buffer_remaining(pkt) < sizeof(uint16_t)*2)
 		return LDNS_RCODE_FORMERR;

util/data/msgreply.c

@@ -50,24 +50,15 @@
 #include "util/region-allocator.h"
 #include "util/data/msgparse.h"
 
-/** copy and allocate an uncompressed dname. */
-static uint8_t*
-copy_uncompr(uint8_t* dname, size_t len) 
-{
-	uint8_t* p = (uint8_t*)malloc(len);
-	if(!p) 
-		return 0;
-	memmove(p, dname, len);
-	return p;
-}
-
 /** allocate qinfo, return 0 on error. */
 static int
-parse_create_qinfo(struct msg_parse* msg, struct query_info* qinf)
+parse_create_qinfo(ldns_buffer* pkt, struct msg_parse* msg, 
+	struct query_info* qinf)
 {
 	if(msg->qname) {
-		if(!(qinf->qname = copy_uncompr(msg->qname, msg->qname_len)))
+		qinf->qname = (uint8_t*)malloc(msg->qname_len);
-			return 0;
+		if(!qinf->qname) return 0;
+		dname_pkt_copy(pkt, qinf->qname, msg->qname);
 	} else	qinf->qname = 0;
 	qinf->qnamesize = msg->qname_len;
 	qinf->qtype = msg->qtype;
@@ -298,7 +289,7 @@ parse_create_msg(ldns_buffer* pkt, struct msg_parse* msg,
 {
 	int ret;
 	log_assert(pkt && msg);
-	if(!parse_create_qinfo(msg, qinf))
+	if(!parse_create_qinfo(pkt, msg, qinf))
 		return LDNS_RCODE_SERVFAIL;
 	if(!parse_create_repinfo(msg, rep))
 		return LDNS_RCODE_SERVFAIL;