a85b5759f3
These files were pulled from the 1.6.3 release tarball. This new version builds against OpenSSL version 1.1 which will be the default in the new Debian Stable which is due to be released RealSoonNow (tm).
789 lines
17 KiB
C
789 lines
17 KiB
C
/*
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* util/data/dname.h - domain name handling
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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 file contains domain name handling functions.
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*/
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#include "config.h"
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#include <ctype.h>
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#include "util/data/dname.h"
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#include "util/data/msgparse.h"
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#include "util/log.h"
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#include "util/storage/lookup3.h"
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#include "sldns/sbuffer.h"
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/* determine length of a dname in buffer, no compression pointers allowed */
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size_t
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query_dname_len(sldns_buffer* query)
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{
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size_t len = 0;
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size_t labellen;
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while(1) {
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if(sldns_buffer_remaining(query) < 1)
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return 0; /* parse error, need label len */
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labellen = sldns_buffer_read_u8(query);
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if(labellen&0xc0)
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return 0; /* no compression allowed in queries */
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len += labellen + 1;
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if(len > LDNS_MAX_DOMAINLEN)
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return 0; /* too long */
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if(labellen == 0)
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return len;
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if(sldns_buffer_remaining(query) < labellen)
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return 0; /* parse error, need content */
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sldns_buffer_skip(query, (ssize_t)labellen);
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}
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}
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size_t
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dname_valid(uint8_t* dname, size_t maxlen)
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{
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size_t len = 0;
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size_t labellen;
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labellen = *dname++;
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while(labellen) {
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if(labellen&0xc0)
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return 0; /* no compression ptrs allowed */
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len += labellen + 1;
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if(len >= LDNS_MAX_DOMAINLEN)
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return 0; /* too long */
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if(len > maxlen)
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return 0; /* does not fit in memory allocation */
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dname += labellen;
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labellen = *dname++;
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}
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len += 1;
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if(len > maxlen)
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return 0; /* does not fit in memory allocation */
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return len;
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}
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/** compare uncompressed, noncanonical, registers are hints for speed */
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int
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query_dname_compare(register uint8_t* d1, register uint8_t* d2)
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{
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register uint8_t lab1, lab2;
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log_assert(d1 && d2);
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lab1 = *d1++;
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lab2 = *d2++;
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while( lab1 != 0 || lab2 != 0 ) {
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/* compare label length */
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/* if one dname ends, it has labellength 0 */
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if(lab1 != lab2) {
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if(lab1 < lab2)
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return -1;
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return 1;
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}
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log_assert(lab1 == lab2 && lab1 != 0);
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/* compare lowercased labels. */
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while(lab1--) {
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/* compare bytes first for speed */
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if(*d1 != *d2 &&
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tolower((unsigned char)*d1) != tolower((unsigned char)*d2)) {
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if(tolower((unsigned char)*d1) < tolower((unsigned char)*d2))
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return -1;
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return 1;
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}
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d1++;
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d2++;
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}
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/* next pair of labels. */
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lab1 = *d1++;
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lab2 = *d2++;
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}
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return 0;
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}
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void
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query_dname_tolower(uint8_t* dname)
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{
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/* the dname is stored uncompressed */
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uint8_t labellen;
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labellen = *dname;
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while(labellen) {
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dname++;
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while(labellen--) {
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*dname = (uint8_t)tolower((unsigned char)*dname);
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dname++;
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}
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labellen = *dname;
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}
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}
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void
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pkt_dname_tolower(sldns_buffer* pkt, uint8_t* dname)
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{
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uint8_t lablen;
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int count = 0;
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if(dname >= sldns_buffer_end(pkt))
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return;
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lablen = *dname++;
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while(lablen) {
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if(LABEL_IS_PTR(lablen)) {
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if((size_t)PTR_OFFSET(lablen, *dname)
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>= sldns_buffer_limit(pkt))
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return;
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dname = sldns_buffer_at(pkt, PTR_OFFSET(lablen, *dname));
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lablen = *dname++;
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if(count++ > MAX_COMPRESS_PTRS)
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return;
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continue;
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}
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if(dname+lablen >= sldns_buffer_end(pkt))
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return;
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while(lablen--) {
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*dname = (uint8_t)tolower((unsigned char)*dname);
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dname++;
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}
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if(dname >= sldns_buffer_end(pkt))
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return;
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lablen = *dname++;
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}
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}
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size_t
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pkt_dname_len(sldns_buffer* pkt)
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{
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size_t len = 0;
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int ptrcount = 0;
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uint8_t labellen;
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size_t endpos = 0;
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/* read dname and determine length */
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/* check compression pointers, loops, out of bounds */
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while(1) {
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/* read next label */
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if(sldns_buffer_remaining(pkt) < 1)
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return 0;
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labellen = sldns_buffer_read_u8(pkt);
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if(LABEL_IS_PTR(labellen)) {
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/* compression ptr */
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uint16_t ptr;
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if(sldns_buffer_remaining(pkt) < 1)
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return 0;
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ptr = PTR_OFFSET(labellen, sldns_buffer_read_u8(pkt));
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if(ptrcount++ > MAX_COMPRESS_PTRS)
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return 0; /* loop! */
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if(sldns_buffer_limit(pkt) <= ptr)
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return 0; /* out of bounds! */
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if(!endpos)
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endpos = sldns_buffer_position(pkt);
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sldns_buffer_set_position(pkt, ptr);
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} else {
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/* label contents */
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if(labellen > 0x3f)
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return 0; /* label too long */
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len += 1 + labellen;
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if(len > LDNS_MAX_DOMAINLEN)
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return 0;
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if(labellen == 0) {
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/* end of dname */
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break;
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}
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if(sldns_buffer_remaining(pkt) < labellen)
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return 0;
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sldns_buffer_skip(pkt, (ssize_t)labellen);
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}
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}
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if(endpos)
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sldns_buffer_set_position(pkt, endpos);
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return len;
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}
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int
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dname_pkt_compare(sldns_buffer* pkt, uint8_t* d1, uint8_t* d2)
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{
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uint8_t len1, len2;
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log_assert(pkt && d1 && d2);
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len1 = *d1++;
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len2 = *d2++;
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while( len1 != 0 || len2 != 0 ) {
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/* resolve ptrs */
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if(LABEL_IS_PTR(len1)) {
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d1 = sldns_buffer_at(pkt, PTR_OFFSET(len1, *d1));
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len1 = *d1++;
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continue;
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}
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if(LABEL_IS_PTR(len2)) {
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d2 = sldns_buffer_at(pkt, PTR_OFFSET(len2, *d2));
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len2 = *d2++;
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continue;
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}
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/* check label length */
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log_assert(len1 <= LDNS_MAX_LABELLEN);
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log_assert(len2 <= LDNS_MAX_LABELLEN);
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if(len1 != len2) {
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if(len1 < len2) return -1;
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return 1;
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}
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log_assert(len1 == len2 && len1 != 0);
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/* compare labels */
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while(len1--) {
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if(tolower((unsigned char)*d1) != tolower((unsigned char)*d2)) {
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if(tolower((unsigned char)*d1) < tolower((unsigned char)*d2))
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return -1;
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return 1;
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}
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d1++;
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d2++;
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}
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len1 = *d1++;
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len2 = *d2++;
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}
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return 0;
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}
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hashvalue_type
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dname_query_hash(uint8_t* dname, hashvalue_type h)
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{
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uint8_t labuf[LDNS_MAX_LABELLEN+1];
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uint8_t lablen;
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int i;
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/* preserve case of query, make hash label by label */
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lablen = *dname++;
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while(lablen) {
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log_assert(lablen <= LDNS_MAX_LABELLEN);
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labuf[0] = lablen;
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i=0;
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while(lablen--) {
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labuf[++i] = (uint8_t)tolower((unsigned char)*dname);
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dname++;
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}
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h = hashlittle(labuf, labuf[0] + 1, h);
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lablen = *dname++;
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}
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return h;
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}
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hashvalue_type
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dname_pkt_hash(sldns_buffer* pkt, uint8_t* dname, hashvalue_type h)
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{
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uint8_t labuf[LDNS_MAX_LABELLEN+1];
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uint8_t lablen;
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int i;
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/* preserve case of query, make hash label by label */
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lablen = *dname++;
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while(lablen) {
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if(LABEL_IS_PTR(lablen)) {
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/* follow pointer */
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dname = sldns_buffer_at(pkt, PTR_OFFSET(lablen, *dname));
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lablen = *dname++;
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continue;
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}
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log_assert(lablen <= LDNS_MAX_LABELLEN);
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labuf[0] = lablen;
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i=0;
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while(lablen--) {
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labuf[++i] = (uint8_t)tolower((unsigned char)*dname);
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dname++;
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}
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h = hashlittle(labuf, labuf[0] + 1, h);
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lablen = *dname++;
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}
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return h;
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}
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void dname_pkt_copy(sldns_buffer* pkt, uint8_t* to, uint8_t* dname)
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{
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/* copy over the dname and decompress it at the same time */
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size_t len = 0;
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uint8_t lablen;
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lablen = *dname++;
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while(lablen) {
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if(LABEL_IS_PTR(lablen)) {
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/* follow pointer */
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dname = sldns_buffer_at(pkt, PTR_OFFSET(lablen, *dname));
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lablen = *dname++;
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continue;
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}
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log_assert(lablen <= LDNS_MAX_LABELLEN);
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len += (size_t)lablen+1;
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if(len >= LDNS_MAX_DOMAINLEN) {
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*to = 0; /* end the result prematurely */
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log_err("bad dname in dname_pkt_copy");
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return;
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}
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*to++ = lablen;
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memmove(to, dname, lablen);
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dname += lablen;
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to += lablen;
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lablen = *dname++;
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}
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/* copy last \0 */
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*to = 0;
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}
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void dname_print(FILE* out, struct sldns_buffer* pkt, uint8_t* dname)
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{
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uint8_t lablen;
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if(!out) out = stdout;
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if(!dname) return;
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lablen = *dname++;
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if(!lablen)
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fputc('.', out);
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while(lablen) {
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if(LABEL_IS_PTR(lablen)) {
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/* follow pointer */
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if(!pkt) {
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fputs("??compressionptr??", out);
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return;
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}
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dname = sldns_buffer_at(pkt, PTR_OFFSET(lablen, *dname));
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lablen = *dname++;
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continue;
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}
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if(lablen > LDNS_MAX_LABELLEN) {
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fputs("??extendedlabel??", out);
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return;
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}
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while(lablen--)
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fputc((int)*dname++, out);
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fputc('.', out);
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lablen = *dname++;
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}
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}
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int
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dname_count_labels(uint8_t* dname)
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{
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uint8_t lablen;
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int labs = 1;
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lablen = *dname++;
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while(lablen) {
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labs++;
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dname += lablen;
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lablen = *dname++;
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}
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return labs;
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}
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int
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dname_count_size_labels(uint8_t* dname, size_t* size)
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{
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uint8_t lablen;
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int labs = 1;
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size_t sz = 1;
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lablen = *dname++;
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while(lablen) {
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labs++;
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sz += lablen+1;
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dname += lablen;
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lablen = *dname++;
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}
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*size = sz;
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return labs;
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}
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/**
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* Compare labels in memory, lowercase while comparing.
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* @param p1: label 1
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* @param p2: label 2
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* @param len: number of bytes to compare.
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* @return: 0, -1, +1 comparison result.
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*/
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static int
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memlowercmp(uint8_t* p1, uint8_t* p2, uint8_t len)
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{
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while(len--) {
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if(*p1 != *p2 && tolower((unsigned char)*p1) != tolower((unsigned char)*p2)) {
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if(tolower((unsigned char)*p1) < tolower((unsigned char)*p2))
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return -1;
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return 1;
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}
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p1++;
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p2++;
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}
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return 0;
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}
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int
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dname_lab_cmp(uint8_t* d1, int labs1, uint8_t* d2, int labs2, int* mlabs)
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{
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uint8_t len1, len2;
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int atlabel = labs1;
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int lastmlabs;
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int lastdiff = 0;
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/* first skip so that we compare same label. */
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if(labs1 > labs2) {
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while(atlabel > labs2) {
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len1 = *d1++;
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d1 += len1;
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atlabel--;
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}
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log_assert(atlabel == labs2);
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} else if(labs1 < labs2) {
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atlabel = labs2;
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while(atlabel > labs1) {
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len2 = *d2++;
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d2 += len2;
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atlabel--;
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}
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log_assert(atlabel == labs1);
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}
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lastmlabs = atlabel+1;
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/* now at same label in d1 and d2, atlabel */
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/* www.example.com. */
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/* 4 3 2 1 atlabel number */
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/* repeat until at root label (which is always the same) */
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while(atlabel > 1) {
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len1 = *d1++;
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len2 = *d2++;
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if(len1 != len2) {
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log_assert(len1 != 0 && len2 != 0);
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if(len1<len2)
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lastdiff = -1;
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else lastdiff = 1;
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lastmlabs = atlabel;
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d1 += len1;
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d2 += len2;
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} else {
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/* memlowercmp is inlined here; or just like
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* if((c=memlowercmp(d1, d2, len1)) != 0) {
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* lastdiff = c;
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* lastmlabs = atlabel; } apart from d1++,d2++ */
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while(len1) {
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if(*d1 != *d2 && tolower((unsigned char)*d1)
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!= tolower((unsigned char)*d2)) {
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if(tolower((unsigned char)*d1) <
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tolower((unsigned char)*d2)) {
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lastdiff = -1;
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lastmlabs = atlabel;
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d1 += len1;
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d2 += len1;
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break;
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}
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lastdiff = 1;
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lastmlabs = atlabel;
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d1 += len1;
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d2 += len1;
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break; /* out of memlowercmp */
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}
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d1++;
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d2++;
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len1--;
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}
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}
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atlabel--;
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}
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/* last difference atlabel number, so number of labels matching,
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* at the right side, is one less. */
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*mlabs = lastmlabs-1;
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if(lastdiff == 0) {
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/* all labels compared were equal, check if one has more
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* labels, so that example.com. > com. */
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if(labs1 > labs2)
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return 1;
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else if(labs1 < labs2)
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return -1;
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}
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|
return lastdiff;
|
|
}
|
|
|
|
int
|
|
dname_buffer_write(sldns_buffer* pkt, uint8_t* dname)
|
|
{
|
|
uint8_t lablen;
|
|
|
|
if(sldns_buffer_remaining(pkt) < 1)
|
|
return 0;
|
|
lablen = *dname++;
|
|
sldns_buffer_write_u8(pkt, lablen);
|
|
while(lablen) {
|
|
if(sldns_buffer_remaining(pkt) < (size_t)lablen+1)
|
|
return 0;
|
|
sldns_buffer_write(pkt, dname, lablen);
|
|
dname += lablen;
|
|
lablen = *dname++;
|
|
sldns_buffer_write_u8(pkt, lablen);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
void dname_str(uint8_t* dname, char* str)
|
|
{
|
|
size_t len = 0;
|
|
uint8_t lablen = 0;
|
|
char* s = str;
|
|
if(!dname || !*dname) {
|
|
*s++ = '.';
|
|
*s = 0;
|
|
return;
|
|
}
|
|
lablen = *dname++;
|
|
while(lablen) {
|
|
if(lablen > LDNS_MAX_LABELLEN) {
|
|
*s++ = '#';
|
|
*s = 0;
|
|
return;
|
|
}
|
|
len += lablen+1;
|
|
if(len >= LDNS_MAX_DOMAINLEN-1) {
|
|
*s++ = '&';
|
|
*s = 0;
|
|
return;
|
|
}
|
|
while(lablen--) {
|
|
if(isalnum((unsigned char)*dname)
|
|
|| *dname == '-' || *dname == '_'
|
|
|| *dname == '*')
|
|
*s++ = *(char*)dname++;
|
|
else {
|
|
*s++ = '?';
|
|
dname++;
|
|
}
|
|
}
|
|
*s++ = '.';
|
|
lablen = *dname++;
|
|
}
|
|
*s = 0;
|
|
}
|
|
|
|
int
|
|
dname_strict_subdomain(uint8_t* d1, int labs1, uint8_t* d2, int labs2)
|
|
{
|
|
int m;
|
|
/* check subdomain: d1: www.example.com. and d2: example.com. */
|
|
if(labs2 >= labs1)
|
|
return 0;
|
|
if(dname_lab_cmp(d1, labs1, d2, labs2, &m) > 0) {
|
|
/* subdomain if all labels match */
|
|
return (m == labs2);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
dname_strict_subdomain_c(uint8_t* d1, uint8_t* d2)
|
|
{
|
|
return dname_strict_subdomain(d1, dname_count_labels(d1), d2,
|
|
dname_count_labels(d2));
|
|
}
|
|
|
|
int
|
|
dname_subdomain_c(uint8_t* d1, uint8_t* d2)
|
|
{
|
|
int m;
|
|
/* check subdomain: d1: www.example.com. and d2: example.com. */
|
|
/* or d1: example.com. and d2: example.com. */
|
|
int labs1 = dname_count_labels(d1);
|
|
int labs2 = dname_count_labels(d2);
|
|
if(labs2 > labs1)
|
|
return 0;
|
|
if(dname_lab_cmp(d1, labs1, d2, labs2, &m) < 0) {
|
|
/* must have been example.com , www.example.com - wrong */
|
|
/* or otherwise different dnames */
|
|
return 0;
|
|
}
|
|
return (m == labs2);
|
|
}
|
|
|
|
int
|
|
dname_is_root(uint8_t* dname)
|
|
{
|
|
uint8_t len;
|
|
log_assert(dname);
|
|
len = dname[0];
|
|
log_assert(!LABEL_IS_PTR(len));
|
|
return (len == 0);
|
|
}
|
|
|
|
void
|
|
dname_remove_label(uint8_t** dname, size_t* len)
|
|
{
|
|
size_t lablen;
|
|
log_assert(dname && *dname && len);
|
|
lablen = (*dname)[0];
|
|
log_assert(!LABEL_IS_PTR(lablen));
|
|
log_assert(*len > lablen);
|
|
if(lablen == 0)
|
|
return; /* do not modify root label */
|
|
*len -= lablen+1;
|
|
*dname += lablen+1;
|
|
}
|
|
|
|
void
|
|
dname_remove_labels(uint8_t** dname, size_t* len, int n)
|
|
{
|
|
int i;
|
|
for(i=0; i<n; i++)
|
|
dname_remove_label(dname, len);
|
|
}
|
|
|
|
int
|
|
dname_signame_label_count(uint8_t* dname)
|
|
{
|
|
uint8_t lablen;
|
|
int count = 0;
|
|
if(!*dname)
|
|
return 0;
|
|
if(dname[0] == 1 && dname[1] == '*')
|
|
dname += 2;
|
|
lablen = dname[0];
|
|
while(lablen) {
|
|
count++;
|
|
dname += lablen;
|
|
dname += 1;
|
|
lablen = dname[0];
|
|
}
|
|
return count;
|
|
}
|
|
|
|
int
|
|
dname_is_wild(uint8_t* dname)
|
|
{
|
|
return (dname[0] == 1 && dname[1] == '*');
|
|
}
|
|
|
|
/**
|
|
* Compare labels in memory, lowercase while comparing.
|
|
* Returns canonical order for labels. If all is equal, the
|
|
* shortest is first.
|
|
*
|
|
* @param p1: label 1
|
|
* @param len1: length of label 1.
|
|
* @param p2: label 2
|
|
* @param len2: length of label 2.
|
|
* @return: 0, -1, +1 comparison result.
|
|
*/
|
|
static int
|
|
memcanoncmp(uint8_t* p1, uint8_t len1, uint8_t* p2, uint8_t len2)
|
|
{
|
|
uint8_t min = (len1<len2)?len1:len2;
|
|
int c = memlowercmp(p1, p2, min);
|
|
if(c != 0)
|
|
return c;
|
|
/* equal, see who is shortest */
|
|
if(len1 < len2)
|
|
return -1;
|
|
if(len1 > len2)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
|
|
int
|
|
dname_canon_lab_cmp(uint8_t* d1, int labs1, uint8_t* d2, int labs2, int* mlabs)
|
|
{
|
|
/* like dname_lab_cmp, but with different label comparison,
|
|
* empty character sorts before \000.
|
|
* So ylyly is before z. */
|
|
uint8_t len1, len2;
|
|
int atlabel = labs1;
|
|
int lastmlabs;
|
|
int lastdiff = 0;
|
|
int c;
|
|
/* first skip so that we compare same label. */
|
|
if(labs1 > labs2) {
|
|
while(atlabel > labs2) {
|
|
len1 = *d1++;
|
|
d1 += len1;
|
|
atlabel--;
|
|
}
|
|
log_assert(atlabel == labs2);
|
|
} else if(labs1 < labs2) {
|
|
atlabel = labs2;
|
|
while(atlabel > labs1) {
|
|
len2 = *d2++;
|
|
d2 += len2;
|
|
atlabel--;
|
|
}
|
|
log_assert(atlabel == labs1);
|
|
}
|
|
lastmlabs = atlabel+1;
|
|
/* now at same label in d1 and d2, atlabel */
|
|
/* www.example.com. */
|
|
/* 4 3 2 1 atlabel number */
|
|
/* repeat until at root label (which is always the same) */
|
|
while(atlabel > 1) {
|
|
len1 = *d1++;
|
|
len2 = *d2++;
|
|
|
|
if((c=memcanoncmp(d1, len1, d2, len2)) != 0) {
|
|
if(c<0)
|
|
lastdiff = -1;
|
|
else lastdiff = 1;
|
|
lastmlabs = atlabel;
|
|
}
|
|
|
|
d1 += len1;
|
|
d2 += len2;
|
|
atlabel--;
|
|
}
|
|
/* last difference atlabel number, so number of labels matching,
|
|
* at the right side, is one less. */
|
|
*mlabs = lastmlabs-1;
|
|
if(lastdiff == 0) {
|
|
/* all labels compared were equal, check if one has more
|
|
* labels, so that example.com. > com. */
|
|
if(labs1 > labs2)
|
|
return 1;
|
|
else if(labs1 < labs2)
|
|
return -1;
|
|
}
|
|
return lastdiff;
|
|
}
|
|
|
|
int
|
|
dname_canonical_compare(uint8_t* d1, uint8_t* d2)
|
|
{
|
|
int labs1, labs2, m;
|
|
labs1 = dname_count_labels(d1);
|
|
labs2 = dname_count_labels(d2);
|
|
return dname_canon_lab_cmp(d1, labs1, d2, labs2, &m);
|
|
}
|
|
|
|
uint8_t* dname_get_shared_topdomain(uint8_t* d1, uint8_t* d2)
|
|
{
|
|
int labs1, labs2, m;
|
|
size_t len = LDNS_MAX_DOMAINLEN;
|
|
labs1 = dname_count_labels(d1);
|
|
labs2 = dname_count_labels(d2);
|
|
(void)dname_lab_cmp(d1, labs1, d2, labs2, &m);
|
|
dname_remove_labels(&d1, &len, labs1-m);
|
|
return d1;
|
|
}
|