410ac6cd67
git-svn-id: https://unbound.nlnetlabs.nl/svn/trunk@3380 be551aaa-1e26-0410-a405-d3ace91eadb9
203 lines
5.7 KiB
C
203 lines
5.7 KiB
C
/*
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* testcode/pktview.c - debug program to disassemble a DNS packet.
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*
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* Copyright (c) 2007, NLnet Labs. All rights reserved.
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*
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* This software is open source.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* Neither the name of the NLNET LABS nor the names of its contributors may
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* be used to endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
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* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/**
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* \file
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*
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* This program shows a dns packet wire format.
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*/
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#include "config.h"
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#include "util/log.h"
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#include "util/data/dname.h"
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#include "util/data/msgparse.h"
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#include "testcode/unitmain.h"
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#include "testcode/readhex.h"
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#include "sldns/sbuffer.h"
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#include "sldns/parseutil.h"
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/** usage information for pktview */
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static void usage(char* argv[])
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{
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printf("usage: %s\n", argv[0]);
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printf("present hex packet on stdin.\n");
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exit(1);
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}
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/** read hex input */
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static void read_input(sldns_buffer* pkt, FILE* in)
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{
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char buf[102400];
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char* np = buf;
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while(fgets(np, (int)sizeof(buf) - (np-buf), in)) {
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if(buf[0] == ';') /* comment */
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continue;
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np = &np[strlen(np)];
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}
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hex_to_buf(pkt, buf);
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}
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/** analyze domain name in packet, possibly compressed */
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static void analyze_dname(sldns_buffer* pkt)
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{
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size_t oldpos = sldns_buffer_position(pkt);
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size_t len;
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printf("[pos %d] dname: ", (int)oldpos);
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dname_print(stdout, pkt, sldns_buffer_current(pkt));
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len = pkt_dname_len(pkt);
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printf(" len=%d", (int)len);
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if(sldns_buffer_position(pkt)-oldpos != len)
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printf(" comprlen=%d\n",
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(int)(sldns_buffer_position(pkt)-oldpos));
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else printf("\n");
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}
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/** analyze rdata in packet */
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static void analyze_rdata(sldns_buffer*pkt, const sldns_rr_descriptor* desc,
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uint16_t rdlen)
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{
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int rdf = 0;
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int count = (int)desc->_dname_count;
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size_t len, oldpos;
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while(rdlen > 0 && count) {
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switch(desc->_wireformat[rdf]) {
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case LDNS_RDF_TYPE_DNAME:
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oldpos = sldns_buffer_position(pkt);
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analyze_dname(pkt);
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rdlen -= sldns_buffer_position(pkt)-oldpos;
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count --;
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len = 0;
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break;
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case LDNS_RDF_TYPE_STR:
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len = sldns_buffer_current(pkt)[0] + 1;
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break;
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default:
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len = get_rdf_size(desc->_wireformat[rdf]);
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}
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if(len) {
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printf(" wf[%d]", (int)len);
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sldns_buffer_skip(pkt, (ssize_t)len);
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rdlen -= len;
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}
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rdf++;
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}
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if(rdlen) {
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size_t i;
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printf(" remain[%d]\n", (int)rdlen);
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for(i=0; i<rdlen; i++)
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printf(" %2.2X", (unsigned)sldns_buffer_current(pkt)[i]);
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printf("\n");
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}
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else printf("\n");
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sldns_buffer_skip(pkt, (ssize_t)rdlen);
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}
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/** analyze rr in packet */
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static void analyze_rr(sldns_buffer* pkt, int q)
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{
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uint16_t type, dclass, len;
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uint32_t ttl;
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analyze_dname(pkt);
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type = sldns_buffer_read_u16(pkt);
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dclass = sldns_buffer_read_u16(pkt);
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printf("type %s(%d)", sldns_rr_descript(type)?
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sldns_rr_descript(type)->_name: "??" , (int)type);
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printf(" class %s(%d) ", sldns_lookup_by_id(sldns_rr_classes,
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(int)dclass)?sldns_lookup_by_id(sldns_rr_classes,
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(int)dclass)->name:"??", (int)dclass);
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if(q) {
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printf("\n");
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} else {
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ttl = sldns_buffer_read_u32(pkt);
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printf(" ttl %d (0x%x)", (int)ttl, (unsigned)ttl);
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len = sldns_buffer_read_u16(pkt);
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printf(" rdata len %d:\n", (int)len);
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if(sldns_rr_descript(type))
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analyze_rdata(pkt, sldns_rr_descript(type), len);
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else sldns_buffer_skip(pkt, (ssize_t)len);
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}
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}
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/** analyse pkt */
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static void analyze(sldns_buffer* pkt)
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{
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uint16_t i, f, qd, an, ns, ar;
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int rrnum = 0;
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printf("packet length %d\n", (int)sldns_buffer_limit(pkt));
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if(sldns_buffer_limit(pkt) < 12) return;
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i = sldns_buffer_read_u16(pkt);
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printf("id (hostorder): %d (0x%x)\n", (int)i, (unsigned)i);
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f = sldns_buffer_read_u16(pkt);
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printf("flags: 0x%x\n", (unsigned)f);
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qd = sldns_buffer_read_u16(pkt);
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printf("qdcount: %d\n", (int)qd);
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an = sldns_buffer_read_u16(pkt);
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printf("ancount: %d\n", (int)an);
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ns = sldns_buffer_read_u16(pkt);
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printf("nscount: %d\n", (int)ns);
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ar = sldns_buffer_read_u16(pkt);
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printf("arcount: %d\n", (int)ar);
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printf(";-- query section\n");
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while(sldns_buffer_remaining(pkt) > 0) {
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if(rrnum == (int)qd)
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printf(";-- answer section\n");
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if(rrnum == (int)qd+(int)an)
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printf(";-- authority section\n");
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if(rrnum == (int)qd+(int)an+(int)ns)
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printf(";-- additional section\n");
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printf("rr %d ", rrnum);
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analyze_rr(pkt, rrnum < (int)qd);
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rrnum++;
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}
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}
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/** main program for pktview */
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int main(int argc, char* argv[])
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{
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sldns_buffer* pkt = sldns_buffer_new(65553);
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if(argc != 1) {
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usage(argv);
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}
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if(!pkt) fatal_exit("out of memory");
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read_input(pkt, stdin);
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analyze(pkt);
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sldns_buffer_free(pkt);
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return 0;
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}
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