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// Copyright (C) 2010 Internet Systems Consortium, Inc. ("ISC")
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.
// $Id$
#include "config.h"
#include <iostream>
#include <string>
#include <sstream>
#include <vector>
#include "base64.h"
#include "buffer.h"
#include "exceptions.h"
#include "messagerenderer.h"
#include "name.h"
#include "rrtype.h"
#include "rrttl.h"
#include "rdata.h"
#include "rdataclass.h"
#include <stdio.h>
#include <time.h>
using namespace std;
// BEGIN_ISC_NAMESPACE
// BEGIN_RDATA_NAMESPACE
struct NSECImpl {
// straightforward representation of NSEC RDATA fields
NSECImpl(const Name& next, vector<uint8_t> typebits) :
nextname_(next), typebits_(typebits)
{}
Name nextname_;
vector<uint8_t> typebits_;
};
NSEC::NSEC(const string& nsec_str) :
impl_(NULL)
{
istringstream iss(nsec_str);
string nextname;
uint8_t bitmap[8 * 1024]; // 64k bits
vector<uint8_t> typebits;
iss >> nextname;
if (iss.bad() || iss.fail()) {
isc_throw(InvalidRdataText, "Invalid NSEC name");
}
memset(bitmap, 0, sizeof(bitmap));
do {
string type;
int code;
iss >> type;
try {
code = RRType(type).getCode();
bitmap[code / 8] |= (0x80 >> (code % 8));
} catch (...) {
isc_throw(InvalidRdataText, "Invalid RRtype in NSEC");
}
} while (!iss.eof());
for (int window = 0; window < 256; window++) {
int octet;
for (octet = 31; octet >= 0; octet--) {
if (bitmap[window * 32 + octet] != 0) {
break;
}
}
if (octet < 0)
continue;
typebits.push_back(window);
typebits.push_back(octet + 1);
for (int i = 0; i <= octet; i++) {
typebits.push_back(bitmap[window * 32 + i]);
}
}
impl_ = new NSECImpl(Name(nextname), typebits);
}
NSEC::NSEC(InputBuffer& buffer, size_t rdata_len) {
const size_t pos = buffer.getPosition();
const Name nextname(buffer);
// rdata_len must be sufficiently large to hold non empty bitmap.
if (rdata_len <= buffer.getPosition() - pos) {
isc_throw(DNSMessageFORMERR,
"NSEC RDATA from wire too short: " << rdata_len << "bytes");
}
rdata_len -= (buffer.getPosition() - pos);
vector<uint8_t> typebits(rdata_len);
buffer.readData(&typebits[0], rdata_len);
int len = 0;
bool first = true;
unsigned int block, lastblock = 0;
for (int i = 0; i < rdata_len; i += len) {
if (i + 2 > rdata_len) {
isc_throw(DNSMessageFORMERR, "NSEC RDATA from wire: "
"incomplete bit map filed");
}
block = typebits[i];
len = typebits[i + 1];
// Check that bitmap window blocks are in the correct order.
if (!first && block <= lastblock) {
isc_throw(DNSMessageFORMERR, "NSEC RDATA from wire: Disordered "
"window blocks found: " << lastblock <<
" then " << block);
}
// Check for legal length
if (len < 1 || len > 32) {
isc_throw(DNSMessageFORMERR, "NSEC RDATA from wire: Invalid bitmap "
"length: " << len);
}
// Check for overflow.
i += 2;
if (i + len > rdata_len) {
isc_throw(DNSMessageFORMERR, "NSEC RDATA from wire: bitmap length "
"too large: " << len);
}
// The last octet of the bitmap must be non zero.
if (typebits[i + len - 1] == 0) {
isc_throw(DNSMessageFORMERR, "NSEC RDATA from wire: bitmap ending "
"an all-zero byte");
}
lastblock = block;
first = false;
}
impl_ = new NSECImpl(nextname, typebits);
}
NSEC::NSEC(const NSEC& source) :
Rdata(), impl_(new NSECImpl(*source.impl_))
{}
NSEC&
NSEC::operator=(const NSEC& source) {
if (impl_ == source.impl_) {
return (*this);
}
NSECImpl* newimpl = new NSECImpl(*source.impl_);
delete impl_;
impl_ = newimpl;
return (*this);
}
NSEC::~NSEC() {
delete impl_;
}
string
NSEC::toText() const {
ostringstream s;
int len = 0;
s << impl_->nextname_;
// In the following loop we use string::at() rather than operator[].
// Since the index calculation is a bit complicated, it will be safer
// and easier to find a bug (if any). Note that this conversion method
// is generally not expected to be very efficient, so the slight overhead
// of at() should be acceptable.
for (int i = 0; i < impl_->typebits_.size(); i += len) {
assert(i + 2 <= impl_->typebits_.size());
const int block = impl_->typebits_.at(i);
len = impl_->typebits_.at(i + 1);
assert(len >= 0 && len <= 32);
i += 2;
for (int j = 0; j < len; j++) {
if (impl_->typebits_.at(i + j) == 0) {
continue;
}
for (int k = 0; k < 8; k++) {
if ((impl_->typebits_.at(i + j) & (0x80 >> k)) == 0) {
continue;
}
const int t = block * 256 + j * 8 + k;
s << " " << RRType(t);
}
}
}
return (s.str());
}
void
NSEC::toWire(OutputBuffer& buffer) const {
impl_->nextname_.toWire(buffer);
buffer.writeData(&impl_->typebits_[0], impl_->typebits_.size());
}
void
NSEC::toWire(MessageRenderer& renderer) const {
impl_->nextname_.toWire(renderer);
renderer.writeData(&impl_->typebits_[0], impl_->typebits_.size());
}
int
NSEC::compare(const Rdata& other) const {
const NSEC& other_nsec = dynamic_cast<const NSEC&>(other);
int cmp = compareNames(impl_->nextname_, other_nsec.impl_->nextname_);
if (cmp != 0) {
return (cmp);
}
const size_t this_len = impl_->typebits_.size();
const size_t other_len = other_nsec.impl_->typebits_.size();
const size_t cmplen = min(this_len, other_len);
cmp = memcmp(&impl_->typebits_[0], &other_nsec.impl_->typebits_[0],
cmplen);
if (cmp != 0) {
return (cmp);
} else {
return ((this_len == other_len) ? 0 : (this_len < other_len) ? -1 : 1);
}
}
// END_RDATA_NAMESPACE
// END_ISC_NAMESPACE
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