work on domain name compression.

git-svn-id: file:///svn/unbound/trunk@257 be551aaa-1e26-0410-a405-d3ace91eadb9
2026-09-13 05:17:44 +02:00 · 2007-04-25 15:28:03 +00:00
parent 02f5c63635
commit f48553bc2d
12 changed files with 771 additions and 59 deletions
@@ -0,0 +1,192 @@
+/*
+ * testcode/pktview.c - debug program to disassemble a DNS packet.
+ *
+ * Copyright (c) 2007, NLnet Labs. All rights reserved.
+ *
+ * This software is open source.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 
+ * Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * 
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ * 
+ * Neither the name of the NLNET LABS nor the names of its contributors may
+ * be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * \file
+ *
+ * This program shows a dns packet wire format.
+ */
+
+#include "config.h"
+#include "util/log.h"
+#include "util/data/dname.h"
+#include "util/data/msgparse.h"
+#include "testcode/unitmain.h"
+#include "testcode/readhex.h"
+
+/** usage information for pktview */
+void usage(char* argv[])
+{
+	printf("usage: %s\n", argv[0]);
+	printf("present hex packet on stdin.\n");
+	exit(1);
+}
+
+/** read hex input */
+void read_input(ldns_buffer* pkt, FILE* in)
+{
+	char buf[102400];
+	char* np = buf;
+	while(fgets(np, (int)sizeof(buf) - (np-buf), in)) {
+		if(buf[0] == ';') /* comment */
+			continue;
+		np = &np[strlen(np)];
+	}
+	hex_to_buf(pkt, buf);
+}
+
+/** analyze domain name in packet, possibly compressed. */
+void analyze_dname(ldns_buffer* pkt)
+{
+	size_t oldpos = ldns_buffer_position(pkt);
+	size_t len;
+	printf("[pos %d] dname: ", (int)oldpos);
+	dname_print(stdout, pkt, ldns_buffer_current(pkt));
+	len = pkt_dname_len(pkt);
+	printf(" len=%d", (int)len);
+	if(ldns_buffer_position(pkt)-oldpos != len)
+		printf(" comprlen=%d\n", 
+			(int)(ldns_buffer_position(pkt)-oldpos));
+	else	printf("\n");
+}
+
+/** analyze rdata in packet */
+void analyze_rdata(ldns_buffer*pkt, const ldns_rr_descriptor* desc, 
+	uint16_t rdlen)
+{
+	int rdf = 0;
+	int count = (int)desc->_dname_count;
+	size_t len, oldpos;
+	while(rdlen > 0 && count) {
+		switch(desc->_wireformat[rdf]) {
+		case LDNS_RDF_TYPE_DNAME:
+			oldpos = ldns_buffer_position(pkt);
+			analyze_dname(pkt);
+			rdlen -= ldns_buffer_position(pkt)-oldpos;
+			count --;
+			len = 0;
+			break;
+		case LDNS_RDF_TYPE_STR:
+			len = ldns_buffer_current(pkt)[0] + 1;
+			break;
+		default:
+			len = get_rdf_size(desc->_wireformat[rdf]);
+		}
+		if(len) {
+			printf(" wf[%d]", (int)len);
+			ldns_buffer_skip(pkt, (ssize_t)len);
+			rdlen -= len;
+		}
+		rdf++;
+	}
+	if(rdlen)
+		printf(" remain[%d]\n", (int)rdlen);
+	else	printf("\n");
+	ldns_buffer_skip(pkt, (ssize_t)rdlen);
+}
+
+/** analyze rr in packet. */
+void analyze_rr(ldns_buffer* pkt, int q)
+{
+	uint16_t type, dclass, len;
+	uint32_t ttl;
+	analyze_dname(pkt);
+	type = ldns_buffer_read_u16(pkt);
+	dclass = ldns_buffer_read_u16(pkt);
+	printf("type %s(%d)", ldns_rr_descript(type)?  
+		ldns_rr_descript(type)->_name: "??" , (int)type);
+	printf(" class %s(%d) ", ldns_lookup_by_id(ldns_rr_classes, 
+		(int)dclass)?ldns_lookup_by_id( ldns_rr_classes, 
+		(int)dclass)->name:"??", (int)dclass);
+	if(q) {
+		printf("\n");
+	} else {
+		ttl = ldns_buffer_read_u32(pkt);
+		printf(" ttl %d (0x%x)", ttl, ttl);
+		len = ldns_buffer_read_u16(pkt);
+		printf(" rdata len %d:\n", len);
+		if(ldns_rr_descript(type))
+			analyze_rdata(pkt, ldns_rr_descript(type), len);
+		else ldns_buffer_skip(pkt, (ssize_t)len);
+	}
+}
+
+/** analyse pkt */
+void analyze(ldns_buffer* pkt)
+{
+	uint16_t i, f, qd, an, ns, ar;
+	int rrnum = 0;
+	printf("packet length %d\n", (int)ldns_buffer_limit(pkt));
+	if(ldns_buffer_limit(pkt) < 12) return;
+
+	i = ldns_buffer_read_u16(pkt);
+	printf("id (hostorder): %d (0x%x)\n", i, i);
+	f = ldns_buffer_read_u16(pkt);
+	printf("flags: 0x%x\n", f);
+	qd = ldns_buffer_read_u16(pkt);
+	printf("qdcount: %d\n", qd);
+	an = ldns_buffer_read_u16(pkt);
+	printf("ancount: %d\n", an);
+	ns = ldns_buffer_read_u16(pkt);
+	printf("nscount: %d\n", ns);
+	ar = ldns_buffer_read_u16(pkt);
+	printf("arcount: %d\n", ar);
+	
+	printf(";-- query section\n");
+	while(ldns_buffer_remaining(pkt) > 0) {
+		if(rrnum == qd) printf(";-- answer section\n");
+		if(rrnum == qd+an) printf(";-- authority section\n");
+		if(rrnum == qd+an+ns) printf(";-- additional section\n");
+		printf("rr %d ", rrnum);
+		analyze_rr(pkt, rrnum < qd);
+		rrnum++;
+	}
+}
+
+/** main program for pktview */
+int main(int argc, char* argv[]) 
+{
+	ldns_buffer* pkt = ldns_buffer_new(65553);
+	if(argc != 1) {
+		usage(argv);
+	}
+	if(!pkt) fatal_exit("out of memory");
+
+	read_input(pkt, stdin);
+	analyze(pkt);
+
+	ldns_buffer_free(pkt);
+	return 0;
+}