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/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* SPDX-License-Identifier: MPL-2.0
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, you can obtain one at https://mozilla.org/MPL/2.0/.
*
* See the COPYRIGHT file distributed with this work for additional
* information regarding copyright ownership.
*/
#include <assert.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include <isc/buffer.h>
#include <isc/lex.h>
#include <isc/mem.h>
#include <isc/result.h>
#include <isc/util.h>
#include <dns/callbacks.h>
#include <dns/compress.h>
#include <dns/master.h>
#include <dns/rdata.h>
#include <dns/rdatatype.h>
#include "fuzz.h"
bool debug = false;
/*
* Fuzz input to dns_rdata_fromwire(). Then convert the result
* to text, back to wire format, to multiline text, and back to wire
* format again, checking for consistency throughout the sequence.
*/
static isc_mem_t *mctx = NULL;
static isc_lex_t *lex = NULL;
int
LLVMFuzzerInitialize(int *argc __attribute__((unused)),
char ***argv __attribute__((unused))) {
isc_lexspecials_t specials;
isc_mem_create(&mctx);
CHECK(isc_lex_create(mctx, 64, &lex));
memset(specials, 0, sizeof(specials));
specials[0] = 1;
specials['('] = 1;
specials[')'] = 1;
specials['"'] = 1;
isc_lex_setspecials(lex, specials);
isc_lex_setcomments(lex, ISC_LEXCOMMENT_DNSMASTERFILE);
return (0);
}
static void
nullmsg(dns_rdatacallbacks_t *cb, const char *fmt, ...) {
va_list args;
UNUSED(cb);
if (debug) {
va_start(args, fmt);
vfprintf(stderr, fmt, args);
fprintf(stderr, "\n");
va_end(args);
}
}
int
LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
char totext[64 * 1044 * 4];
dns_compress_t cctx;
dns_decompress_t dctx;
dns_rdatatype_t rdtype;
dns_rdataclass_t rdclass;
dns_rdatatype_t typelist[256] = { 1000 }; /* unknown */
dns_rdataclass_t classlist[] = { dns_rdataclass_in, dns_rdataclass_hs,
dns_rdataclass_ch, dns_rdataclass_any,
60 };
dns_rdata_t rdata1 = DNS_RDATA_INIT, rdata2 = DNS_RDATA_INIT,
rdata3 = DNS_RDATA_INIT;
dns_rdatacallbacks_t callbacks;
isc_buffer_t source, target;
isc_result_t result;
unsigned char fromtext[1024];
unsigned char fromwire[1024];
unsigned char towire[1024];
unsigned int classes = (sizeof(classlist) / sizeof(classlist[0]));
unsigned int types = 1, flags, t;
/*
* First 2 bytes are used to select type and class.
* dns_rdata_fromwire() only accepts input up to 2^16-1 octets.
*/
if (size < 2 || size > 0xffff + 2) {
return (0);
}
/*
* Append known types to list.
*/
for (t = 1; t <= 0x10000; t++) {
char typebuf[256];
if (dns_rdatatype_ismeta(t)) {
continue;
}
dns_rdatatype_format(t, typebuf, sizeof(typebuf));
if (strncmp(typebuf, "TYPE", 4) != 0) {
/* Assert when we need to grow typelist. */
assert(types < sizeof(typelist) / sizeof(typelist[0]));
typelist[types++] = t;
}
}
/*
* Random type and class from a limited set.
*/
rdtype = typelist[(*data++) % types];
size--;
rdclass = classlist[(*data++) % classes];
size--;
if (debug) {
fprintf(stderr, "type=%u, class=%u\n", rdtype, rdclass);
}
dns_rdatacallbacks_init(&callbacks);
callbacks.warn = callbacks.error = nullmsg;
/* Disallow decompression as we are reading a packet */
dns_decompress_init(&dctx, -1, DNS_DECOMPRESS_NONE);
isc_buffer_constinit(&source, data, size);
isc_buffer_add(&source, size);
isc_buffer_setactive(&source, size);
isc_buffer_init(&target, fromwire, sizeof(fromwire));
/*
* Reject invalid rdata.
*/
CHECK(dns_rdata_fromwire(&rdata1, rdclass, rdtype, &source, &dctx, 0,
&target));
assert(rdata1.length == size);
/*
* Convert to text from wire.
*/
isc_buffer_init(&target, totext, sizeof(totext) - 1);
result = dns_rdata_totext(&rdata1, NULL, &target);
assert(result == ISC_R_SUCCESS);
/*
* Make debugging easier by NUL terminating.
*/
totext[isc_buffer_usedlength(&target)] = 0;
/*
* Convert to wire from text.
*/
isc_buffer_constinit(&source, totext, isc_buffer_usedlength(&target));
isc_buffer_add(&source, isc_buffer_usedlength(&target));
CHECK(isc_lex_openbuffer(lex, &source));
isc_buffer_init(&target, fromtext, sizeof(fromtext));
result = dns_rdata_fromtext(&rdata2, rdclass, rdtype, lex, dns_rootname,
0, mctx, &target, &callbacks);
if (debug && result != ISC_R_SUCCESS) {
fprintf(stderr, "'%s'\n", totext);
}
assert(result == ISC_R_SUCCESS);
assert(rdata2.length == size);
assert(!memcmp(rdata2.data, data, size));
/*
* Convert to multi-line text from wire.
*/
isc_buffer_init(&target, totext, sizeof(totext));
flags = dns_master_styleflags(&dns_master_style_default);
result = dns_rdata_tofmttext(&rdata1, dns_rootname, flags, 80 - 32, 4,
"\n", &target);
assert(result == ISC_R_SUCCESS);
/*
* Convert to wire from text.
*/
isc_buffer_constinit(&source, totext, isc_buffer_usedlength(&target));
isc_buffer_add(&source, isc_buffer_usedlength(&target));
CHECK(isc_lex_openbuffer(lex, &source));
isc_buffer_init(&target, fromtext, sizeof(fromtext));
result = dns_rdata_fromtext(&rdata3, rdclass, rdtype, lex, dns_rootname,
0, mctx, &target, &callbacks);
assert(result == ISC_R_SUCCESS);
assert(rdata3.length == size);
assert(!memcmp(rdata3.data, data, size));
/*
* Convert rdata back to wire.
*/
CHECK(dns_compress_init(&cctx, -1, mctx));
dns_compress_disable(&cctx);
isc_buffer_init(&target, towire, sizeof(towire));
result = dns_rdata_towire(&rdata1, &cctx, &target);
dns_compress_invalidate(&cctx);
assert(result == ISC_R_SUCCESS);
assert(target.used == size);
assert(!memcmp(target.base, data, size));
return (0);
}
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