qt6-bb10/src/network/kernel/qdnslookup_unix.cpp

338 lines
13 KiB
C++

/****************************************************************************
**
** Copyright (C) 2012 Jeremy Lainé <jeremy.laine@m4x.org>
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtNetwork module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia. For licensing terms and
** conditions see http://qt.digia.com/licensing. For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights. These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "qdnslookup_p.h"
#include <qlibrary.h>
#include <qscopedpointer.h>
#include <qurl.h>
#include <private/qmutexpool_p.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <arpa/nameser_compat.h>
#include <resolv.h>
QT_BEGIN_NAMESPACE
#ifndef QT_NO_LIBRARY
typedef int (*dn_expand_proto)(const unsigned char *, const unsigned char *, const unsigned char *, char *, int);
static dn_expand_proto local_dn_expand = 0;
typedef void (*res_nclose_proto)(res_state);
static res_nclose_proto local_res_nclose = 0;
typedef int (*res_ninit_proto)(res_state);
static res_ninit_proto local_res_ninit = 0;
typedef int (*res_nquery_proto)(res_state, const char *, int, int, unsigned char *, int);
static res_nquery_proto local_res_nquery = 0;
// Custom deleter to close resolver state.
struct QDnsLookupStateDeleter
{
static inline void cleanup(struct __res_state *pointer)
{
local_res_nclose(pointer);
}
};
static void resolveLibrary()
{
QLibrary lib(QLatin1String("resolv"));
if (!lib.load())
return;
local_dn_expand = dn_expand_proto(lib.resolve("__dn_expand"));
if (!local_dn_expand)
local_dn_expand = dn_expand_proto(lib.resolve("dn_expand"));
local_res_nclose = res_nclose_proto(lib.resolve("__res_nclose"));
if (!local_res_nclose)
local_res_nclose = res_nclose_proto(lib.resolve("res_9_nclose"));
if (!local_res_nclose)
local_res_nclose = res_nclose_proto(lib.resolve("res_nclose"));
local_res_ninit = res_ninit_proto(lib.resolve("__res_ninit"));
if (!local_res_ninit)
local_res_ninit = res_ninit_proto(lib.resolve("res_9_ninit"));
if (!local_res_ninit)
local_res_ninit = res_ninit_proto(lib.resolve("res_ninit"));
local_res_nquery = res_nquery_proto(lib.resolve("__res_nquery"));
if (!local_res_nquery)
local_res_nquery = res_nquery_proto(lib.resolve("res_9_nquery"));
if (!local_res_nquery)
local_res_nquery = res_nquery_proto(lib.resolve("res_nquery"));
}
void QDnsLookupRunnable::query(const int requestType, const QByteArray &requestName, QDnsLookupReply *reply)
{
// Load dn_expand, res_ninit and res_nquery on demand.
static QBasicAtomicInt triedResolve = Q_BASIC_ATOMIC_INITIALIZER(false);
if (!triedResolve.loadAcquire()) {
QMutexLocker locker(QMutexPool::globalInstanceGet(&local_res_ninit));
if (!triedResolve.load()) {
resolveLibrary();
triedResolve.storeRelease(true);
}
}
// If dn_expand, res_ninit or res_nquery is missing, fail.
if (!local_dn_expand || !local_res_nclose || !local_res_ninit || !local_res_nquery) {
reply->error = QDnsLookup::ResolverError;
reply->errorString = tr("Resolver functions not found");
return;
}
// Initialize state.
struct __res_state state;
memset(&state, 0, sizeof(state));
if (local_res_ninit(&state) < 0) {
reply->error = QDnsLookup::ResolverError;
reply->errorString = tr("Resolver initialization failed");
return;
}
#ifdef QDNSLOOKUP_DEBUG
state.options |= RES_DEBUG;
#endif
QScopedPointer<struct __res_state, QDnsLookupStateDeleter> state_ptr(&state);
// Perform DNS query.
unsigned char response[PACKETSZ];
memset(response, 0, sizeof(response));
const int responseLength = local_res_nquery(&state, requestName, C_IN, requestType, response, sizeof(response));
// Check the response header.
HEADER *header = (HEADER*)response;
const int answerCount = ntohs(header->ancount);
switch (header->rcode) {
case NOERROR:
break;
case FORMERR:
reply->error = QDnsLookup::InvalidRequestError;
reply->errorString = tr("Server could not process query");
return;
case SERVFAIL:
reply->error = QDnsLookup::ServerFailureError;
reply->errorString = tr("Server failure");
return;
case NXDOMAIN:
reply->error = QDnsLookup::NotFoundError;
reply->errorString = tr("Non existent domain");
return;
case REFUSED:
reply->error = QDnsLookup::ServerRefusedError;
reply->errorString = tr("Server refused to answer");
return;
default:
reply->error = QDnsLookup::InvalidReplyError;
reply->errorString = tr("Invalid reply received");
return;
}
// Check the reply is valid.
if (responseLength < int(sizeof(HEADER))) {
reply->error = QDnsLookup::InvalidReplyError;
reply->errorString = tr("Invalid reply received");
return;
}
// Skip the query host, type (2 bytes) and class (2 bytes).
char host[PACKETSZ], answer[PACKETSZ];
unsigned char *p = response + sizeof(HEADER);
int status = local_dn_expand(response, response + responseLength, p, host, sizeof(host));
if (status < 0) {
reply->error = QDnsLookup::InvalidReplyError;
reply->errorString = tr("Could not expand domain name");
return;
}
p += status + 4;
// Extract results.
int answerIndex = 0;
while ((p < response + responseLength) && (answerIndex < answerCount)) {
status = local_dn_expand(response, response + responseLength, p, host, sizeof(host));
if (status < 0) {
reply->error = QDnsLookup::InvalidReplyError;
reply->errorString = tr("Could not expand domain name");
return;
}
const QString name = QUrl::fromAce(host);
p += status;
const quint16 type = (p[0] << 8) | p[1];
p += 2; // RR type
p += 2; // RR class
const quint32 ttl = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
p += 4;
const quint16 size = (p[0] << 8) | p[1];
p += 2;
if (type == QDnsLookup::A) {
if (size != 4) {
reply->error = QDnsLookup::InvalidReplyError;
reply->errorString = tr("Invalid IPv4 address record");
return;
}
const quint32 addr = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
QDnsHostAddressRecord record;
record.d->name = name;
record.d->timeToLive = ttl;
record.d->value = QHostAddress(addr);
reply->hostAddressRecords.append(record);
} else if (type == QDnsLookup::AAAA) {
if (size != 16) {
reply->error = QDnsLookup::InvalidReplyError;
reply->errorString = tr("Invalid IPv6 address record");
return;
}
QDnsHostAddressRecord record;
record.d->name = name;
record.d->timeToLive = ttl;
record.d->value = QHostAddress(p);
reply->hostAddressRecords.append(record);
} else if (type == QDnsLookup::CNAME) {
status = local_dn_expand(response, response + responseLength, p, answer, sizeof(answer));
if (status < 0) {
reply->error = QDnsLookup::InvalidReplyError;
reply->errorString = tr("Invalid canonical name record");
return;
}
QDnsDomainNameRecord record;
record.d->name = name;
record.d->timeToLive = ttl;
record.d->value = QUrl::fromAce(answer);
reply->canonicalNameRecords.append(record);
} else if (type == QDnsLookup::NS) {
status = local_dn_expand(response, response + responseLength, p, answer, sizeof(answer));
if (status < 0) {
reply->error = QDnsLookup::InvalidReplyError;
reply->errorString = tr("Invalid name server record");
return;
}
QDnsDomainNameRecord record;
record.d->name = name;
record.d->timeToLive = ttl;
record.d->value = QUrl::fromAce(answer);
reply->nameServerRecords.append(record);
} else if (type == QDnsLookup::PTR) {
status = local_dn_expand(response, response + responseLength, p, answer, sizeof(answer));
if (status < 0) {
reply->error = QDnsLookup::InvalidReplyError;
reply->errorString = tr("Invalid pointer record");
return;
}
QDnsDomainNameRecord record;
record.d->name = name;
record.d->timeToLive = ttl;
record.d->value = QUrl::fromAce(answer);
reply->pointerRecords.append(record);
} else if (type == QDnsLookup::MX) {
const quint16 preference = (p[0] << 8) | p[1];
status = local_dn_expand(response, response + responseLength, p + 2, answer, sizeof(answer));
if (status < 0) {
reply->error = QDnsLookup::InvalidReplyError;
reply->errorString = tr("Invalid mail exchange record");
return;
}
QDnsMailExchangeRecord record;
record.d->exchange = QUrl::fromAce(answer);
record.d->name = name;
record.d->preference = preference;
record.d->timeToLive = ttl;
reply->mailExchangeRecords.append(record);
} else if (type == QDnsLookup::SRV) {
const quint16 priority = (p[0] << 8) | p[1];
const quint16 weight = (p[2] << 8) | p[3];
const quint16 port = (p[4] << 8) | p[5];
status = local_dn_expand(response, response + responseLength, p + 6, answer, sizeof(answer));
if (status < 0) {
reply->error = QDnsLookup::InvalidReplyError;
reply->errorString = tr("Invalid service record");
return;
}
QDnsServiceRecord record;
record.d->name = name;
record.d->target = QUrl::fromAce(answer);
record.d->port = port;
record.d->priority = priority;
record.d->timeToLive = ttl;
record.d->weight = weight;
reply->serviceRecords.append(record);
} else if (type == QDnsLookup::TXT) {
unsigned char *txt = p;
QDnsTextRecord record;
record.d->name = name;
record.d->timeToLive = ttl;
while (txt < p + size) {
const unsigned char length = *txt;
txt++;
if (txt + length > p + size) {
reply->error = QDnsLookup::InvalidReplyError;
reply->errorString = tr("Invalid text record");
return;
}
record.d->values << QByteArray((char*)txt, length);
txt += length;
}
reply->textRecords.append(record);
}
p += size;
answerIndex++;
}
}
#else
void QDnsLookupRunnable::query(const int requestType, const QByteArray &requestName, QDnsLookupReply *reply)
{
Q_UNUSED(requestType)
Q_UNUSED(requestName)
reply->error = QDnsLookup::ResolverError;
reply->errorString = tr("Resolver library can't be loaded: No runtime library loading support");
return;
}
#endif /* ifndef QT_NO_LIBRARY */
QT_END_NAMESPACE