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|
// Copyright (C) 2009-2015 Internet Systems Consortium, Inc. ("ISC")
//
// 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 http://mozilla.org/MPL/2.0/.
#include <config.h>
#include <stdint.h>
#include <algorithm>
#include <cassert>
#include <string>
#include <sstream>
#include <vector>
#include <boost/foreach.hpp>
#include <boost/lexical_cast.hpp>
#include <boost/shared_ptr.hpp>
#include <exceptions/exceptions.h>
#include <util/buffer.h>
#include <dns/edns.h>
#include <dns/exceptions.h>
#include <dns/message.h>
#include <dns/messagerenderer.h>
#include <dns/name.h>
#include <dns/opcode.h>
#include <dns/rcode.h>
#include <dns/question.h>
#include <dns/rdataclass.h>
#include <dns/rrclass.h>
#include <dns/rrtype.h>
#include <dns/rrttl.h>
#include <dns/rrset.h>
#include <dns/tsig.h>
using namespace std;
using boost::lexical_cast;
using namespace isc::dns::rdata;
using namespace isc::util;
namespace isc {
namespace dns {
namespace {
// protocol constants
const size_t HEADERLEN = 12;
const unsigned int OPCODE_MASK = 0x7800;
const unsigned int OPCODE_SHIFT = 11;
const unsigned int RCODE_MASK = 0x000f;
// This diagram shows the wire-format representation of the 2nd 16 bits of
// the DNS header section, which contain all defined flag bits.
//
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// |QR| Opcode |AA|TC|RD|RA| |AD|CD| RCODE |
// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
// 1 0 0 0| 0 1 1 1| 1 0 1 1| 0 0 0 0|
// 0x8 0x7 0xb 0x0
//
// This mask covers all the flag bits, and those bits only.
// Note: we reject a "flag" the is not covered by this mask in some of the
// public methods. This means our current definition is not fully extendable;
// applications cannot introduce a new flag bit temporarily without modifying
// the source code.
const unsigned int HEADERFLAG_MASK = 0x87b0;
// This is a set of flag bits that should be preserved when building a reply
// from a request.
// Note: we assume the specific definition of HEADERFLAG_xx. We may change
// the definition in future, in which case we need to adjust this definition,
// too (see also the description about the Message::HeaderFlag type).
const uint16_t MESSAGE_REPLYPRESERVE = (Message::HEADERFLAG_RD |
Message::HEADERFLAG_CD);
const char* const sectiontext[] = {
"QUESTION",
"ANSWER",
"AUTHORITY",
"ADDITIONAL"
};
}
class MessageImpl {
public:
MessageImpl(Message::Mode mode);
// Open issues: should we rather have a header in wire-format
// for efficiency?
Message::Mode mode_;
qid_t qid_;
// We want to use NULL for [op,r]code_ to mean the code being not
// correctly parsed or set. We store the real code object in
// xxcode_placeholder_ and have xxcode_ refer to it when the object
// is valid.
const Rcode* rcode_;
Rcode rcode_placeholder_;
const Opcode* opcode_;
Opcode opcode_placeholder_;
uint16_t flags_; // wire-format representation of header flags.
bool header_parsed_;
static const unsigned int NUM_SECTIONS = 4; // TODO: revisit this design
int counts_[NUM_SECTIONS]; // TODO: revisit this definition
vector<QuestionPtr> questions_;
vector<RRsetPtr> rrsets_[NUM_SECTIONS];
ConstEDNSPtr edns_;
ConstTSIGRecordPtr tsig_rr_;
// RRsetsSorter* sorter_; : TODO
void init();
void setOpcode(const Opcode& opcode);
void setRcode(const Rcode& rcode);
int parseQuestion(InputBuffer& buffer);
int parseSection(const Message::Section section, InputBuffer& buffer,
Message::ParseOptions options);
void addRR(Message::Section section, const Name& name,
const RRClass& rrclass, const RRType& rrtype,
const RRTTL& ttl, ConstRdataPtr rdata,
Message::ParseOptions options);
// There are also times where an RR needs to be added that
// represents an empty RRset. There is no Rdata in that case
void addRR(Message::Section section, const Name& name,
const RRClass& rrclass, const RRType& rrtype,
const RRTTL& ttl, Message::ParseOptions options);
void addEDNS(Message::Section section, const Name& name,
const RRClass& rrclass, const RRType& rrtype,
const RRTTL& ttl, const Rdata& rdata);
void addTSIG(Message::Section section, unsigned int count,
const InputBuffer& buffer, size_t start_position,
const Name& name, const RRClass& rrclass,
const RRTTL& ttl, const Rdata& rdata);
void toWire(AbstractMessageRenderer& renderer, TSIGContext* tsig_ctx);
};
MessageImpl::MessageImpl(Message::Mode mode) :
mode_(mode),
rcode_placeholder_(Rcode(0)), // as a placeholder the value doesn't matter
opcode_placeholder_(Opcode(0)) // ditto
{
init();
}
void
MessageImpl::init() {
flags_ = 0;
qid_ = 0;
rcode_ = NULL;
opcode_ = NULL;
edns_ = EDNSPtr();
tsig_rr_ = ConstTSIGRecordPtr();
for (int i = 0; i < NUM_SECTIONS; ++i) {
counts_[i] = 0;
}
header_parsed_ = false;
questions_.clear();
rrsets_[Message::SECTION_ANSWER].clear();
rrsets_[Message::SECTION_AUTHORITY].clear();
rrsets_[Message::SECTION_ADDITIONAL].clear();
}
void
MessageImpl::setOpcode(const Opcode& opcode) {
opcode_placeholder_ = opcode;
opcode_ = &opcode_placeholder_;
}
void
MessageImpl::setRcode(const Rcode& rcode) {
rcode_placeholder_ = rcode;
rcode_ = &rcode_placeholder_;
}
namespace {
// This helper class is used by MessageImpl::toWire() to render a set of
// RRsets of a specific section of message to a given MessageRenderer.
//
// A RenderSection object is expected to be used with a QuestionIterator or
// SectionIterator. Its operator() is called for each RRset as the iterator
// iterates over the corresponding section, and it renders the RRset to
// the given MessageRenderer, while counting the number of RRs (note: not
// RRsets) successfully rendered. If the MessageRenderer reports the need
// for truncation (via its isTruncated() method), the RenderSection object
// stops rendering further RRsets. In addition, unless partial_ok (given on
// construction) is true, it removes any RRs that are partially rendered
// from the MessageRenderer.
//
// On the completion of rendering the entire section, the owner of the
// RenderSection object can get the number of rendered RRs via the
// getTotalCount() method.
template <typename T>
struct RenderSection {
RenderSection(AbstractMessageRenderer& renderer, const bool partial_ok) :
counter_(0), renderer_(renderer), partial_ok_(partial_ok),
truncated_(false)
{}
void operator()(const T& entry) {
// If it's already truncated, ignore the rest of the section.
if (truncated_) {
return;
}
const size_t pos0 = renderer_.getLength();
counter_ += entry->toWire(renderer_);
if (renderer_.isTruncated()) {
truncated_ = true;
if (!partial_ok_) {
// roll back to the end of the previous RRset.
renderer_.trim(renderer_.getLength() - pos0);
}
}
}
unsigned int getTotalCount() { return (counter_); }
unsigned int counter_;
AbstractMessageRenderer& renderer_;
const bool partial_ok_;
bool truncated_;
};
}
void
MessageImpl::toWire(AbstractMessageRenderer& renderer, TSIGContext* tsig_ctx) {
if (mode_ != Message::RENDER) {
isc_throw(InvalidMessageOperation,
"Message rendering attempted in non render mode");
}
if (rcode_ == NULL) {
isc_throw(InvalidMessageOperation,
"Message rendering attempted without Rcode set");
}
if (opcode_ == NULL) {
isc_throw(InvalidMessageOperation,
"Message rendering attempted without Opcode set");
}
// Reserve the space for TSIG (if needed) so that we can handle truncation
// case correctly later when that happens. orig_xxx variables remember
// some configured parameters of renderer in case they are needed in
// truncation processing below.
const size_t tsig_len = (tsig_ctx != NULL) ? tsig_ctx->getTSIGLength() : 0;
const size_t orig_msg_len_limit = renderer.getLengthLimit();
const AbstractMessageRenderer::CompressMode orig_compress_mode =
renderer.getCompressMode();
// We are going to skip soon, so we need to clear the renderer
// But we'll leave the length limit and the compress mode intact
// (or shortened in case of TSIG)
renderer.clear();
renderer.setCompressMode(orig_compress_mode);
if (tsig_len > 0) {
if (tsig_len > orig_msg_len_limit) {
isc_throw(InvalidParameter, "Failed to render DNS message: "
"too small limit for a TSIG (" <<
orig_msg_len_limit << ")");
}
renderer.setLengthLimit(orig_msg_len_limit - tsig_len);
} else {
renderer.setLengthLimit(orig_msg_len_limit);
}
// reserve room for the header
if (renderer.getLengthLimit() < HEADERLEN) {
isc_throw(InvalidParameter, "Failed to render DNS message: "
"too small limit for a Header");
}
renderer.skip(HEADERLEN);
uint16_t qdcount =
for_each(questions_.begin(), questions_.end(),
RenderSection<QuestionPtr>(renderer, false)).getTotalCount();
// TODO: sort RRsets in each section based on configuration policy.
uint16_t ancount = 0;
if (!renderer.isTruncated()) {
ancount =
for_each(rrsets_[Message::SECTION_ANSWER].begin(),
rrsets_[Message::SECTION_ANSWER].end(),
RenderSection<RRsetPtr>(renderer, true)).getTotalCount();
}
uint16_t nscount = 0;
if (!renderer.isTruncated()) {
nscount =
for_each(rrsets_[Message::SECTION_AUTHORITY].begin(),
rrsets_[Message::SECTION_AUTHORITY].end(),
RenderSection<RRsetPtr>(renderer, true)).getTotalCount();
}
uint16_t arcount = 0;
if (renderer.isTruncated()) {
flags_ |= Message::HEADERFLAG_TC;
} else {
arcount =
for_each(rrsets_[Message::SECTION_ADDITIONAL].begin(),
rrsets_[Message::SECTION_ADDITIONAL].end(),
RenderSection<RRsetPtr>(renderer, false)).getTotalCount();
}
// Add EDNS OPT RR if necessary. Basically, we add it only when EDNS
// has been explicitly set. However, if the RCODE would require it and
// no EDNS has been set we generate a temporary local EDNS and use it.
if (!renderer.isTruncated()) {
ConstEDNSPtr local_edns = edns_;
if (!local_edns && rcode_->getExtendedCode() != 0) {
local_edns = ConstEDNSPtr(new EDNS());
}
if (local_edns) {
arcount += local_edns->toWire(renderer, rcode_->getExtendedCode());
}
}
// If we're adding a TSIG to a truncated message, clear all RRsets
// from the message except for the question before adding the TSIG.
// If even (some of) the question doesn't fit, don't include it.
if (tsig_ctx != NULL && renderer.isTruncated()) {
renderer.clear();
renderer.setLengthLimit(orig_msg_len_limit - tsig_len);
renderer.setCompressMode(orig_compress_mode);
renderer.skip(HEADERLEN);
qdcount = for_each(questions_.begin(), questions_.end(),
RenderSection<QuestionPtr>(renderer,
false)).getTotalCount();
ancount = 0;
nscount = 0;
arcount = 0;
}
// Adjust the counter buffer.
// XXX: these may not be equal to the number of corresponding entries
// in rrsets_[] or questions_ if truncation occurred or an EDNS OPT RR
// was inserted. This is not good, and we should revisit the entire
// design.
counts_[Message::SECTION_QUESTION] = qdcount;
counts_[Message::SECTION_ANSWER] = ancount;
counts_[Message::SECTION_AUTHORITY] = nscount;
counts_[Message::SECTION_ADDITIONAL] = arcount;
// fill in the header
size_t header_pos = 0;
renderer.writeUint16At(qid_, header_pos);
header_pos += sizeof(uint16_t);
uint16_t codes_and_flags =
(opcode_->getCode() << OPCODE_SHIFT) & OPCODE_MASK;
codes_and_flags |= (rcode_->getCode() & RCODE_MASK);
codes_and_flags |= (flags_ & HEADERFLAG_MASK);
renderer.writeUint16At(codes_and_flags, header_pos);
header_pos += sizeof(uint16_t);
// TODO: should avoid repeated pattern
renderer.writeUint16At(qdcount, header_pos);
header_pos += sizeof(uint16_t);
renderer.writeUint16At(ancount, header_pos);
header_pos += sizeof(uint16_t);
renderer.writeUint16At(nscount, header_pos);
header_pos += sizeof(uint16_t);
renderer.writeUint16At(arcount, header_pos);
// Add TSIG, if necessary, at the end of the message.
if (tsig_ctx != NULL) {
// Release the reserved space in the renderer.
renderer.setLengthLimit(orig_msg_len_limit);
const int tsig_count =
tsig_ctx->sign(qid_, renderer.getData(),
renderer.getLength())->toWire(renderer);
if (tsig_count != 1) {
isc_throw(Unexpected, "Failed to render a TSIG RR");
}
// update the ARCOUNT for the TSIG RR. Note that for a sane DNS
// message arcount should never overflow to 0.
renderer.writeUint16At(++arcount, header_pos);
}
}
Message::Message(Mode mode) :
impl_(new MessageImpl(mode))
{}
Message::~Message() {
delete impl_;
}
bool
Message::getHeaderFlag(const HeaderFlag flag) const {
if (flag == 0 || (flag & ~HEADERFLAG_MASK) != 0) {
isc_throw(InvalidParameter,
"Message::getHeaderFlag:: Invalid flag is specified: " <<
"0x" << std::hex << flag);
}
return ((impl_->flags_ & flag) != 0);
}
void
Message::setHeaderFlag(const HeaderFlag flag, const bool on) {
if (impl_->mode_ != Message::RENDER) {
isc_throw(InvalidMessageOperation,
"setHeaderFlag performed in non-render mode");
}
if (flag == 0 || (flag & ~HEADERFLAG_MASK) != 0) {
isc_throw(InvalidParameter,
"Message::getHeaderFlag:: Invalid flag is specified: " <<
"0x" << std::hex << flag);
}
if (on) {
impl_->flags_ |= flag;
} else {
impl_->flags_ &= ~flag;
}
}
qid_t
Message::getQid() const {
return (impl_->qid_);
}
void
Message::setQid(qid_t qid) {
if (impl_->mode_ != Message::RENDER) {
isc_throw(InvalidMessageOperation,
"setQid performed in non-render mode");
}
impl_->qid_ = qid;
}
const Rcode&
Message::getRcode() const {
if (impl_->rcode_ == NULL) {
isc_throw(InvalidMessageOperation, "getRcode attempted before set");
}
return (*impl_->rcode_);
}
void
Message::setRcode(const Rcode& rcode) {
if (impl_->mode_ != Message::RENDER) {
isc_throw(InvalidMessageOperation,
"setRcode performed in non-render mode");
}
impl_->setRcode(rcode);
}
const Opcode&
Message::getOpcode() const {
if (impl_->opcode_ == NULL) {
isc_throw(InvalidMessageOperation, "getOpcode attempted before set");
}
return (*impl_->opcode_);
}
void
Message::setOpcode(const Opcode& opcode) {
if (impl_->mode_ != Message::RENDER) {
isc_throw(InvalidMessageOperation,
"setOpcode performed in non-render mode");
}
impl_->setOpcode(opcode);
}
ConstEDNSPtr
Message::getEDNS() const {
return (impl_->edns_);
}
void
Message::setEDNS(ConstEDNSPtr edns) {
if (impl_->mode_ != Message::RENDER) {
isc_throw(InvalidMessageOperation,
"setEDNS performed in non-render mode");
}
impl_->edns_ = edns;
}
const TSIGRecord*
Message::getTSIGRecord() const {
if (impl_->mode_ != Message::PARSE) {
isc_throw(InvalidMessageOperation,
"getTSIGRecord performed in non-parse mode");
}
return (impl_->tsig_rr_.get());
}
unsigned int
Message::getRRCount(const Section section) const {
if (static_cast<int>(section) >= MessageImpl::NUM_SECTIONS) {
isc_throw(OutOfRange, "Invalid message section: " << section);
}
return (impl_->counts_[section]);
}
void
Message::addRRset(const Section section, RRsetPtr rrset) {
if (!rrset) {
isc_throw(InvalidParameter,
"NULL RRset is given to Message::addRRset");
}
if (impl_->mode_ != Message::RENDER) {
isc_throw(InvalidMessageOperation,
"addRRset performed in non-render mode");
}
if (static_cast<int>(section) >= MessageImpl::NUM_SECTIONS) {
isc_throw(OutOfRange, "Invalid message section: " << section);
}
impl_->rrsets_[section].push_back(rrset);
impl_->counts_[section] += rrset->getRdataCount();
impl_->counts_[section] += rrset->getRRsigDataCount();
}
bool
Message::hasRRset(const Section section, const Name& name,
const RRClass& rrclass, const RRType& rrtype) const
{
if (static_cast<int>(section) >= MessageImpl::NUM_SECTIONS) {
isc_throw(OutOfRange, "Invalid message section: " << section);
}
BOOST_FOREACH(ConstRRsetPtr r, impl_->rrsets_[section]) {
if (r->getClass() == rrclass &&
r->getType() == rrtype &&
r->getName() == name) {
return (true);
}
}
return (false);
}
bool
Message::hasRRset(const Section section, const RRsetPtr& rrset) const {
return (hasRRset(section, rrset->getName(),
rrset->getClass(), rrset->getType()));
}
bool
Message::removeRRset(const Section section, RRsetIterator& iterator) {
if (static_cast<int>(section) >= MessageImpl::NUM_SECTIONS) {
isc_throw(OutOfRange, "Invalid message section: " << section);
}
bool removed = false;
for (vector<RRsetPtr>::iterator i = impl_->rrsets_[section].begin();
i != impl_->rrsets_[section].end(); ++i) {
if (((*i)->getName() == (*iterator)->getName()) &&
((*i)->getClass() == (*iterator)->getClass()) &&
((*i)->getType() == (*iterator)->getType())) {
// Found the matching RRset so remove it & ignore rest
impl_->counts_[section] -= (*iterator)->getRdataCount();
impl_->counts_[section] -= (*iterator)->getRRsigDataCount();
impl_->rrsets_[section].erase(i);
removed = true;
break;
}
}
return (removed);
}
void
Message::clearSection(const Section section) {
if (impl_->mode_ != Message::RENDER) {
isc_throw(InvalidMessageOperation,
"clearSection performed in non-render mode");
}
if (static_cast<int>(section) >= MessageImpl::NUM_SECTIONS) {
isc_throw(OutOfRange, "Invalid message section: " << section);
}
if (section == Message::SECTION_QUESTION) {
impl_->questions_.clear();
} else {
impl_->rrsets_[section].clear();
}
impl_->counts_[section] = 0;
}
void
Message::addQuestion(const QuestionPtr question) {
if (impl_->mode_ != Message::RENDER) {
isc_throw(InvalidMessageOperation,
"addQuestion performed in non-render mode");
}
impl_->questions_.push_back(question);
++impl_->counts_[SECTION_QUESTION];
}
void
Message::addQuestion(const Question& question) {
addQuestion(QuestionPtr(new Question(question)));
}
void
Message::toWire(AbstractMessageRenderer& renderer, TSIGContext* tsig_ctx) {
impl_->toWire(renderer, tsig_ctx);
}
void
Message::parseHeader(InputBuffer& buffer) {
if (impl_->mode_ != Message::PARSE) {
isc_throw(InvalidMessageOperation,
"Message parse attempted in non parse mode");
}
if (impl_->header_parsed_) {
return;
}
if ((buffer.getLength() - buffer.getPosition()) < HEADERLEN) {
isc_throw(MessageTooShort, "Malformed DNS message (short length): "
<< buffer.getLength() - buffer.getPosition());
}
impl_->qid_ = buffer.readUint16();
const uint16_t codes_and_flags = buffer.readUint16();
impl_->setOpcode(Opcode((codes_and_flags & OPCODE_MASK) >> OPCODE_SHIFT));
impl_->setRcode(Rcode(codes_and_flags & RCODE_MASK));
impl_->flags_ = (codes_and_flags & HEADERFLAG_MASK);
impl_->counts_[SECTION_QUESTION] = buffer.readUint16();
impl_->counts_[SECTION_ANSWER] = buffer.readUint16();
impl_->counts_[SECTION_AUTHORITY] = buffer.readUint16();
impl_->counts_[SECTION_ADDITIONAL] = buffer.readUint16();
impl_->header_parsed_ = true;
}
void
Message::fromWire(InputBuffer& buffer, ParseOptions options) {
if (impl_->mode_ != Message::PARSE) {
isc_throw(InvalidMessageOperation,
"Message parse attempted in non parse mode");
}
// Clear any old parsed data
clear(Message::PARSE);
buffer.setPosition(0);
parseHeader(buffer);
impl_->counts_[SECTION_QUESTION] = impl_->parseQuestion(buffer);
impl_->counts_[SECTION_ANSWER] =
impl_->parseSection(SECTION_ANSWER, buffer, options);
impl_->counts_[SECTION_AUTHORITY] =
impl_->parseSection(SECTION_AUTHORITY, buffer, options);
impl_->counts_[SECTION_ADDITIONAL] =
impl_->parseSection(SECTION_ADDITIONAL, buffer, options);
}
int
MessageImpl::parseQuestion(InputBuffer& buffer) {
unsigned int added = 0;
for (unsigned int count = 0;
count < counts_[Message::SECTION_QUESTION];
++count) {
const Name name(buffer);
if ((buffer.getLength() - buffer.getPosition()) <
2 * sizeof(uint16_t)) {
isc_throw(DNSMessageFORMERR, "Question section too short: " <<
(buffer.getLength() - buffer.getPosition()) << " bytes");
}
const RRType rrtype(buffer.readUint16());
const RRClass rrclass(buffer.readUint16());
// XXX: need a duplicate check. We might also want to have an
// optimized algorithm that requires the question section contain
// exactly one RR.
questions_.push_back(QuestionPtr(new Question(name, rrclass, rrtype)));
++added;
}
return (added);
}
namespace {
struct MatchRR : public unary_function<RRsetPtr, bool> {
MatchRR(const Name& name, const RRType& rrtype, const RRClass& rrclass) :
name_(name), rrtype_(rrtype), rrclass_(rrclass) {}
bool operator()(const RRsetPtr& rrset) const {
return (rrset->getType() == rrtype_ &&
rrset->getClass() == rrclass_ &&
rrset->getName() == name_);
}
const Name& name_;
const RRType& rrtype_;
const RRClass& rrclass_;
};
}
// Note about design decision:
// we need some type specific processing here, including EDNS and TSIG.
// how much we should generalize/hardcode the special logic is subject
// to discussion. In terms of modularity it would be ideal to introduce
// an abstract class (say "MessageAttribute") and let other such
// concrete notions as EDNS or TSIG inherit from it. Then we would
// just do:
// message->addAttribute(rrtype, rrclass, buffer);
// to create and attach type-specific concrete object to the message.
//
// A major downside of this approach is, as usual, complexity due to
// indirection and performance penalty. Also, it may not be so easy
// to separate the processing logic because in many cases we'll need
// parse context for which the message class is responsible (e.g.
// to check the EDNS OPT RR only appears in the additional section,
// and appears only once).
//
// Another point to consider is that we may not need so many special
// types other than EDNS and TSIG (and when and if we implement it,
// SIG(0)); newer optional attributes of the message would more likely
// be standardized as new flags or options of EDNS. If that's the case,
// introducing an abstract class with all the overhead and complexity
// may not make much sense.
//
// Conclusion: don't over-generalize type-specific logic for now.
// introduce separate concrete classes, and move context-independent
// logic to that class; processing logic dependent on parse context
// is hardcoded here.
int
MessageImpl::parseSection(const Message::Section section,
InputBuffer& buffer, Message::ParseOptions options)
{
assert(static_cast<int>(section) < MessageImpl::NUM_SECTIONS);
unsigned int added = 0;
for (unsigned int count = 0; count < counts_[section]; ++count) {
// We need to remember the start position for TSIG processing
const size_t start_position = buffer.getPosition();
const Name name(buffer);
// buffer must store at least RR TYPE, RR CLASS, TTL, and RDLEN.
if ((buffer.getLength() - buffer.getPosition()) <
3 * sizeof(uint16_t) + sizeof(uint32_t)) {
isc_throw(DNSMessageFORMERR, sectiontext[section] <<
" section too short: " <<
(buffer.getLength() - buffer.getPosition()) << " bytes");
}
const RRType rrtype(buffer.readUint16());
const RRClass rrclass(buffer.readUint16());
const RRTTL ttl(buffer.readUint32());
const size_t rdlen = buffer.readUint16();
// If class is ANY or NONE, rdlength may be zero, to signal
// an empty RRset.
// (the class check must be done to differentiate from RRTypes
// that can have zero length rdata
if ((rrclass == RRClass::ANY() || rrclass == RRClass::NONE()) &&
rdlen == 0) {
addRR(section, name, rrclass, rrtype, ttl, options);
++added;
continue;
}
ConstRdataPtr rdata = createRdata(rrtype, rrclass, buffer, rdlen);
if (rrtype == RRType::OPT()) {
addEDNS(section, name, rrclass, rrtype, ttl, *rdata);
} else if (rrtype == RRType::TSIG()) {
addTSIG(section, count, buffer, start_position, name, rrclass, ttl,
*rdata);
} else {
addRR(section, name, rrclass, rrtype, ttl, rdata, options);
++added;
}
}
return (added);
}
void
MessageImpl::addRR(Message::Section section, const Name& name,
const RRClass& rrclass, const RRType& rrtype,
const RRTTL& ttl, ConstRdataPtr rdata,
Message::ParseOptions options)
{
if ((options & Message::PRESERVE_ORDER) == 0) {
vector<RRsetPtr>::iterator it =
find_if(rrsets_[section].begin(), rrsets_[section].end(),
MatchRR(name, rrtype, rrclass));
if (it != rrsets_[section].end()) {
(*it)->setTTL(min((*it)->getTTL(), ttl));
(*it)->addRdata(rdata);
return;
}
}
RRsetPtr rrset(new RRset(name, rrclass, rrtype, ttl));
rrset->addRdata(rdata);
rrsets_[section].push_back(rrset);
}
void
MessageImpl::addRR(Message::Section section, const Name& name,
const RRClass& rrclass, const RRType& rrtype,
const RRTTL& ttl, Message::ParseOptions options)
{
if ((options & Message::PRESERVE_ORDER) == 0) {
vector<RRsetPtr>::iterator it =
find_if(rrsets_[section].begin(), rrsets_[section].end(),
MatchRR(name, rrtype, rrclass));
if (it != rrsets_[section].end()) {
(*it)->setTTL(min((*it)->getTTL(), ttl));
return;
}
}
RRsetPtr rrset(new RRset(name, rrclass, rrtype, ttl));
rrsets_[section].push_back(rrset);
}
void
MessageImpl::addEDNS(Message::Section section, const Name& name,
const RRClass& rrclass, const RRType& rrtype,
const RRTTL& ttl, const Rdata& rdata)
{
if (section != Message::SECTION_ADDITIONAL) {
isc_throw(DNSMessageFORMERR,
"EDNS OPT RR found in an invalid section");
}
if (edns_) {
isc_throw(DNSMessageFORMERR, "multiple EDNS OPT RR found");
}
uint8_t extended_rcode;
edns_ = ConstEDNSPtr(createEDNSFromRR(name, rrclass, rrtype, ttl, rdata,
extended_rcode));
setRcode(Rcode(rcode_->getCode(), extended_rcode));
}
void
MessageImpl::addTSIG(Message::Section section, unsigned int count,
const InputBuffer& buffer, size_t start_position,
const Name& name, const RRClass& rrclass,
const RRTTL& ttl, const Rdata& rdata)
{
if (section != Message::SECTION_ADDITIONAL) {
isc_throw(DNSMessageFORMERR,
"TSIG RR found in an invalid section");
}
if (count != counts_[section] - 1) {
isc_throw(DNSMessageFORMERR, "TSIG RR is not the last record");
}
// This check will never fail as the multiple TSIG RR case is
// caught before by the not the last record check...
if (tsig_rr_) {
isc_throw(DNSMessageFORMERR, "multiple TSIG RRs found");
}
tsig_rr_ = ConstTSIGRecordPtr(new TSIGRecord(name, rrclass,
ttl, rdata,
buffer.getPosition() -
start_position));
}
namespace {
template <typename T>
struct SectionFormatter {
SectionFormatter(const Message::Section section, string& output) :
section_(section), output_(output) {}
void operator()(const T& entry) {
if (section_ == Message::SECTION_QUESTION) {
output_ += ";";
output_ += entry->toText();
output_ += "\n";
} else {
output_ += entry->toText();
}
}
const Message::Section section_;
string& output_;
};
}
string
Message::toText() const {
if (impl_->rcode_ == NULL) {
isc_throw(InvalidMessageOperation,
"Message::toText() attempted without Rcode set");
}
if (impl_->opcode_ == NULL) {
isc_throw(InvalidMessageOperation,
"Message::toText() attempted without Opcode set");
}
string s;
s += ";; ->>HEADER<<- opcode: " + impl_->opcode_->toText();
// for simplicity we don't consider extended rcode (unlike BIND9)
s += ", status: " + impl_->rcode_->toText();
s += ", id: " + boost::lexical_cast<string>(impl_->qid_);
s += "\n;; flags:";
if (getHeaderFlag(HEADERFLAG_QR)) {
s += " qr";
}
if (getHeaderFlag(HEADERFLAG_AA)) {
s += " aa";
}
if (getHeaderFlag(HEADERFLAG_TC)) {
s += " tc";
}
if (getHeaderFlag(HEADERFLAG_RD)) {
s += " rd";
}
if (getHeaderFlag(HEADERFLAG_RA)) {
s += " ra";
}
if (getHeaderFlag(HEADERFLAG_AD)) {
s += " ad";
}
if (getHeaderFlag(HEADERFLAG_CD)) {
s += " cd";
}
// for simplicity, don't consider the update case for now
s += "; QUERY: " + // note: not "QUESTION" to be compatible with BIND 9 dig
lexical_cast<string>(impl_->counts_[SECTION_QUESTION]);
s += ", ANSWER: " +
lexical_cast<string>(impl_->counts_[SECTION_ANSWER]);
s += ", AUTHORITY: " +
lexical_cast<string>(impl_->counts_[SECTION_AUTHORITY]);
unsigned int arcount = impl_->counts_[SECTION_ADDITIONAL];
if (impl_->edns_ != NULL) {
++arcount;
}
if (impl_->tsig_rr_ != NULL) {
++arcount;
}
s += ", ADDITIONAL: " + lexical_cast<string>(arcount) + "\n";
if (impl_->edns_ != NULL) {
s += "\n;; OPT PSEUDOSECTION:\n";
s += impl_->edns_->toText();
}
if (!impl_->questions_.empty()) {
s += "\n;; " +
string(sectiontext[SECTION_QUESTION]) + " SECTION:\n";
for_each(impl_->questions_.begin(), impl_->questions_.end(),
SectionFormatter<QuestionPtr>(SECTION_QUESTION, s));
}
if (!impl_->rrsets_[SECTION_ANSWER].empty()) {
s += "\n;; " +
string(sectiontext[SECTION_ANSWER]) + " SECTION:\n";
for_each(impl_->rrsets_[SECTION_ANSWER].begin(),
impl_->rrsets_[SECTION_ANSWER].end(),
SectionFormatter<RRsetPtr>(SECTION_ANSWER, s));
}
if (!impl_->rrsets_[SECTION_AUTHORITY].empty()) {
s += "\n;; " +
string(sectiontext[SECTION_AUTHORITY]) + " SECTION:\n";
for_each(impl_->rrsets_[SECTION_AUTHORITY].begin(),
impl_->rrsets_[SECTION_AUTHORITY].end(),
SectionFormatter<RRsetPtr>(SECTION_AUTHORITY, s));
}
if (!impl_->rrsets_[SECTION_ADDITIONAL].empty()) {
s += "\n;; " +
string(sectiontext[SECTION_ADDITIONAL]) +
" SECTION:\n";
for_each(impl_->rrsets_[SECTION_ADDITIONAL].begin(),
impl_->rrsets_[SECTION_ADDITIONAL].end(),
SectionFormatter<RRsetPtr>(SECTION_ADDITIONAL, s));
}
if (impl_->tsig_rr_ != NULL) {
s += "\n;; TSIG PSEUDOSECTION:\n";
s += impl_->tsig_rr_->toText();
}
return (s);
}
void
Message::clear(Mode mode) {
impl_->init();
impl_->mode_ = mode;
}
void
Message::appendSection(const Section section, const Message& source) {
if (static_cast<int>(section) >= MessageImpl::NUM_SECTIONS) {
isc_throw(OutOfRange, "Invalid message section: " << section);
}
if (section == SECTION_QUESTION) {
for (QuestionIterator qi = source.beginQuestion();
qi != source.endQuestion();
++qi) {
addQuestion(*qi);
}
} else {
for (RRsetIterator rrsi = source.beginSection(section);
rrsi != source.endSection(section);
++rrsi) {
addRRset(section, *rrsi);
}
}
}
void
Message::makeResponse() {
if (impl_->mode_ != Message::PARSE) {
isc_throw(InvalidMessageOperation,
"makeResponse() is performed in non-parse mode");
}
impl_->mode_ = Message::RENDER;
impl_->edns_ = EDNSPtr();
impl_->flags_ &= MESSAGE_REPLYPRESERVE;
setHeaderFlag(HEADERFLAG_QR, true);
impl_->rrsets_[SECTION_ANSWER].clear();
impl_->counts_[SECTION_ANSWER] = 0;
impl_->rrsets_[SECTION_AUTHORITY].clear();
impl_->counts_[SECTION_AUTHORITY] = 0;
impl_->rrsets_[SECTION_ADDITIONAL].clear();
impl_->counts_[SECTION_ADDITIONAL] = 0;
}
///
/// Template version of Section Iterator
///
template <typename T>
struct SectionIteratorImpl {
SectionIteratorImpl(const typename vector<T>::const_iterator& it) :
it_(it) {}
typename vector<T>::const_iterator it_;
};
template <typename T>
SectionIterator<T>::SectionIterator(const SectionIteratorImpl<T>& impl) {
impl_ = new SectionIteratorImpl<T>(impl.it_);
}
template <typename T>
SectionIterator<T>::~SectionIterator() {
delete impl_;
}
template <typename T>
SectionIterator<T>::SectionIterator(const SectionIterator<T>& source) :
impl_(new SectionIteratorImpl<T>(source.impl_->it_))
{}
template <typename T>
void
SectionIterator<T>::operator=(const SectionIterator<T>& source) {
if (impl_ == source.impl_) {
return;
}
SectionIteratorImpl<T>* newimpl =
new SectionIteratorImpl<T>(source.impl_->it_);
delete impl_;
impl_ = newimpl;
}
template <typename T>
SectionIterator<T>&
SectionIterator<T>::operator++() {
++(impl_->it_);
return (*this);
}
template <typename T>
SectionIterator<T>
SectionIterator<T>::operator++(int) {
SectionIterator<T> tmp(*this);
++(*this);
return (tmp);
}
template <typename T>
const T&
SectionIterator<T>::operator*() const {
return (*(impl_->it_));
}
template <typename T>
const T*
SectionIterator<T>::operator->() const {
return (&(operator*()));
}
template <typename T>
bool
SectionIterator<T>::operator==(const SectionIterator<T>& other) const {
return (impl_->it_ == other.impl_->it_);
}
template <typename T>
bool
SectionIterator<T>::operator!=(const SectionIterator<T>& other) const {
return (impl_->it_ != other.impl_->it_);
}
///
/// We need to explicitly instantiate these template classes because these
/// are public classes but defined in this implementation file.
///
template class SectionIterator<QuestionPtr>;
template class SectionIterator<RRsetPtr>;
namespace {
typedef SectionIteratorImpl<QuestionPtr> QuestionIteratorImpl;
typedef SectionIteratorImpl<RRsetPtr> RRsetIteratorImpl;
}
///
/// Question iterator
///
const QuestionIterator
Message::beginQuestion() const {
return (QuestionIterator(QuestionIteratorImpl(impl_->questions_.begin())));
}
const QuestionIterator
Message::endQuestion() const {
return (QuestionIterator(QuestionIteratorImpl(impl_->questions_.end())));
}
///
/// RRsets iterators
///
const SectionIterator<RRsetPtr>
Message::beginSection(const Section section) const {
if (static_cast<int>(section) >= MessageImpl::NUM_SECTIONS) {
isc_throw(OutOfRange, "Invalid message section: " << section);
}
if (section == SECTION_QUESTION) {
isc_throw(InvalidMessageSection,
"RRset iterator is requested for question");
}
return (RRsetIterator(RRsetIteratorImpl(impl_->rrsets_[section].begin())));
}
const SectionIterator<RRsetPtr>
Message::endSection(const Section section) const {
if (static_cast<int>(section) >= MessageImpl::NUM_SECTIONS) {
isc_throw(OutOfRange, "Invalid message section: " << section);
}
if (section == SECTION_QUESTION) {
isc_throw(InvalidMessageSection,
"RRset iterator is requested for question");
}
return (RRsetIterator(RRsetIteratorImpl(impl_->rrsets_[section].end())));
}
ostream&
operator<<(ostream& os, const Message& message) {
return (os << message.toText());
}
} // end of namespace dns
} // end of namespace isc
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