// Copyright Joyent, Inc. and other Node contributors.

//

// Permission is hereby granted, free of charge, to any person obtaining a

// copy of this software and associated documentation files (the

// "Software"), to deal in the Software without restriction, including

// without limitation the rights to use, copy, modify, merge, publish,

// distribute, sublicense, and/or sell copies of the Software, and to permit

// persons to whom the Software is furnished to do so, subject to the

// following conditions:

//

// The above copyright notice and this permission notice shall be included

// in all copies or substantial portions of the Software.

//

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS

// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN

// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,

// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR

// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE

// USE OR OTHER DEALINGS IN THE SOFTWARE.

#include "cares_wrap.h"

#include "ada.h"

#include "async_wrap-inl.h"

#include "base_object-inl.h"

#include "env-inl.h"

#include "memory_tracker-inl.h"

#include "nbytes.h"

#include "node.h"

#include "node_errors.h"

#include "node_external_reference.h"

#include "req_wrap-inl.h"

#include "util-inl.h"

#include "uv.h"

#include "v8.h"

#include <cerrno>

#include <cstring>

#include <memory>

#include <vector>

#include <unordered_set>

#ifndef T_CAA

# define T_CAA 257 /* Certification Authority Authorization */

#endif

// OpenBSD does not define these

#ifndef AI_ALL

# define AI_ALL 0

#endif

#ifndef AI_V4MAPPED

# define AI_V4MAPPED 0

#endif

namespace node {

namespace cares_wrap {

using v8::Array;

using v8::Context;

using v8::EscapableHandleScope;

using v8::FunctionCallbackInfo;

using v8::FunctionTemplate;

using v8::HandleScope;

using v8::Int32;

using v8::Integer;

using v8::Isolate;

using v8::Just;

using v8::Local;

using v8::Maybe;

using v8::Nothing;

using v8::Null;

using v8::Object;

using v8::String;

using v8::Uint32;

using v8::Value;

namespace {

Mutex ares_library_mutex;

inline uint16_t cares_get_16bit(const unsigned char* p) {

return static_cast<uint32_t>(p[0] << 8U) | (static_cast<uint32_t>(p[1]));

}

void ares_poll_cb(uv_poll_t* watcher, int status, int events) {

NodeAresTask* task = ContainerOf(&NodeAresTask::poll_watcher, watcher);

ChannelWrap* channel = task->channel;

/* Reset the idle timer */

uv_timer_again(channel->timer_handle());

if (status < 0) {

/* An error happened. Just pretend that the socket is both readable and */

/* writable. */

ares_process_fd(channel->cares_channel(), task->sock, task->sock);

return;

}

/* Process DNS responses */

ares_process_fd(channel->cares_channel(),

events & UV_READABLE ? task->sock : ARES_SOCKET_BAD,

events & UV_WRITABLE ? task->sock : ARES_SOCKET_BAD);

}

void ares_poll_close_cb(uv_poll_t* watcher) {

std::unique_ptr<NodeAresTask> free_me(

ContainerOf(&NodeAresTask::poll_watcher, watcher));

}

/* Callback from ares when socket operation is started */

void ares_sockstate_cb(void* data, ares_socket_t sock, int read, int write) {

ChannelWrap* channel = static_cast<ChannelWrap*>(data);

NodeAresTask* task;

NodeAresTask lookup_task;

lookup_task.sock = sock;

auto it = channel->task_list()->find(&lookup_task);

task = (it == channel->task_list()->end()) ? nullptr : *it;

if (read || write) {

if (!task) {

/* New socket */

channel->StartTimer();

task = NodeAresTask::Create(channel, sock);

if (task == nullptr) {

/* This should never happen unless we're out of memory or something */

/* is seriously wrong. The socket won't be polled, but the query will */

/* eventually time out. */

return;

}

channel->task_list()->insert(task);

}

/* This should never fail. If it fails anyway, the query will eventually */

/* time out. */

uv_poll_start(&task->poll_watcher,

(read ? UV_READABLE : 0) | (write ? UV_WRITABLE : 0),

ares_poll_cb);

} else {

/* read == 0 and write == 0 this is c-ares's way of notifying us that */

/* the socket is now closed. We must free the data associated with */

/* socket. */

CHECK(task &&

"When an ares socket is closed we should have a handle for it");

channel->task_list()->erase(it);

channel->env()->CloseHandle(&task->poll_watcher, ares_poll_close_cb);

if (channel->task_list()->empty()) {

channel->CloseTimer();

}

}

}

Local<Array> HostentToNames(Environment* env, struct hostent* host) {

EscapableHandleScope scope(env->isolate());

std::vector<Local<Value>> names;

for (uint32_t i = 0; host->h_aliases[i] != nullptr; ++i)

names.emplace_back(OneByteString(env->isolate(), host->h_aliases[i]));

Local<Array> ret = Array::New(env->isolate(), names.data(), names.size());

return scope.Escape(ret);

}

Local<Array> HostentToNames(Environment* env,

struct hostent* host,

Local<Array> names) {

size_t offset = names->Length();

for (uint32_t i = 0; host->h_aliases[i] != nullptr; ++i) {

names->Set(

env->context(),

i + offset,

OneByteString(env->isolate(), host->h_aliases[i])).Check();

}

return names;

}

template <typename T>

Local<Array> AddrTTLToArray(

Environment* env,

const T* addrttls,

size_t naddrttls) {

MaybeStackBuffer<Local<Value>, 8> ttls(naddrttls);

for (size_t i = 0; i < naddrttls; i++)

ttls[i] = Integer::NewFromUnsigned(env->isolate(), addrttls[i].ttl);

return Array::New(env->isolate(), ttls.out(), naddrttls);

}

int ParseGeneralReply(

Environment* env,

const unsigned char* buf,

int len,

int* type,

Local<Array> ret,

void* addrttls = nullptr,

int* naddrttls = nullptr) {

HandleScope handle_scope(env->isolate());

hostent* host;

int status;

switch (*type) {

case ns_t_a:

case ns_t_cname:

case ns_t_cname_or_a:

status = ares_parse_a_reply(buf,

len,

&host,

static_cast<ares_addrttl*>(addrttls),

naddrttls);

break;

case ns_t_aaaa:

status = ares_parse_aaaa_reply(buf,

len,

&host,

static_cast<ares_addr6ttl*>(addrttls),

naddrttls);

break;

case ns_t_ns:

status = ares_parse_ns_reply(buf, len, &host);

break;

case ns_t_ptr:

status = ares_parse_ptr_reply(buf, len, nullptr, 0, AF_INET, &host);

break;

default:

UNREACHABLE("Bad NS type");

}

if (status != ARES_SUCCESS)

return status;

CHECK_NOT_NULL(host);

HostEntPointer ptr(host);

/* If it's `CNAME`, return the CNAME value;

* And if it's `CNAME_OR_A` and it has value in `h_name` and `h_aliases[0]`,

* we consider it's a CNAME record, otherwise we consider it's an A record. */

if ((*type == ns_t_cname_or_a && ptr->h_name && ptr->h_aliases[0]) ||

*type == ns_t_cname) {

// A cname lookup always returns a single record but we follow the

// common API here.

*type = ns_t_cname;

ret->Set(env->context(),

ret->Length(),

OneByteString(env->isolate(), ptr->h_name)).Check();

return ARES_SUCCESS;

}

if (*type == ns_t_cname_or_a)

*type = ns_t_a;

if (*type == ns_t_ns) {

HostentToNames(env, ptr.get(), ret);

} else if (*type == ns_t_ptr) {

uint32_t offset = ret->Length();

for (uint32_t i = 0; ptr->h_aliases[i] != nullptr; i++) {

auto alias = OneByteString(env->isolate(), ptr->h_aliases[i]);

ret->Set(env->context(), i + offset, alias).Check();

}

} else {

uint32_t offset = ret->Length();

char ip[INET6_ADDRSTRLEN];

for (uint32_t i = 0; ptr->h_addr_list[i] != nullptr; ++i) {

uv_inet_ntop(ptr->h_addrtype, ptr->h_addr_list[i], ip, sizeof(ip));

auto address = OneByteString(env->isolate(), ip);

ret->Set(env->context(), i + offset, address).Check();

}

}

return ARES_SUCCESS;

}

int ParseMxReply(

Environment* env,

const unsigned char* buf,

int len,

Local<Array> ret,

bool need_type = false) {

HandleScope handle_scope(env->isolate());

struct ares_mx_reply* mx_start;

int status = ares_parse_mx_reply(buf, len, &mx_start);

if (status != ARES_SUCCESS)

return status;

uint32_t offset = ret->Length();

ares_mx_reply* current = mx_start;

for (uint32_t i = 0; current != nullptr; ++i, current = current->next) {

Local<Object> mx_record = Object::New(env->isolate());

mx_record->Set(env->context(),

env->exchange_string(),

OneByteString(env->isolate(), current->host)).Check();

mx_record->Set(env->context(),

env->priority_string(),

Integer::New(env->isolate(), current->priority)).Check();

if (need_type)

mx_record->Set(env->context(),

env->type_string(),

env->dns_mx_string()).Check();

ret->Set(env->context(), i + offset, mx_record).Check();

}

ares_free_data(mx_start);

return ARES_SUCCESS;

}

int ParseCaaReply(

Environment* env,

const unsigned char* buf,

int len,

Local<Array> ret,

bool need_type = false) {

HandleScope handle_scope(env->isolate());

struct ares_caa_reply* caa_start;

int status = ares_parse_caa_reply(buf, len, &caa_start);

if (status != ARES_SUCCESS)

return status;

uint32_t offset = ret->Length();

ares_caa_reply* current = caa_start;

for (uint32_t i = 0; current != nullptr; ++i, current = current->next) {

Local<Object> caa_record = Object::New(env->isolate());

caa_record->Set(env->context(),

env->dns_critical_string(),

Integer::New(env->isolate(), current->critical)).Check();

caa_record->Set(env->context(),

OneByteString(env->isolate(), current->property),

OneByteString(env->isolate(), current->value)).Check();

if (need_type)

caa_record->Set(env->context(),

env->type_string(),

env->dns_caa_string()).Check();

ret->Set(env->context(), i + offset, caa_record).Check();

}

ares_free_data(caa_start);

return ARES_SUCCESS;

}

int ParseTxtReply(

Environment* env,

const unsigned char* buf,

int len,

Local<Array> ret,

bool need_type = false) {

HandleScope handle_scope(env->isolate());

struct ares_txt_ext* txt_out;

int status = ares_parse_txt_reply_ext(buf, len, &txt_out);

if (status != ARES_SUCCESS)

return status;

Local<Array> txt_chunk;

struct ares_txt_ext* current = txt_out;

uint32_t i = 0, j;

uint32_t offset = ret->Length();

for (j = 0; current != nullptr; current = current->next) {

Local<String> txt =

OneByteString(env->isolate(), current->txt, current->length);

// New record found - write out the current chunk

if (current->record_start) {

if (!txt_chunk.IsEmpty()) {

if (need_type) {

Local<Object> elem = Object::New(env->isolate());

elem->Set(env->context(), env->entries_string(), txt_chunk).Check();

elem->Set(env->context(),

env->type_string(),

env->dns_txt_string()).Check();

ret->Set(env->context(), offset + i++, elem).Check();

} else {

ret->Set(env->context(), offset + i++, txt_chunk).Check();

}

}

txt_chunk = Array::New(env->isolate());

j = 0;

}

txt_chunk->Set(env->context(), j++, txt).Check();

}

// Push last chunk if it isn't empty

if (!txt_chunk.IsEmpty()) {

if (need_type) {

Local<Object> elem = Object::New(env->isolate());

elem->Set(env->context(), env->entries_string(), txt_chunk).Check();

elem->Set(env->context(),

env->type_string(),

env->dns_txt_string()).Check();

ret->Set(env->context(), offset + i, elem).Check();

} else {

ret->Set(env->context(), offset + i, txt_chunk).Check();

}

}

ares_free_data(txt_out);

return ARES_SUCCESS;

}

int ParseSrvReply(

Environment* env,

const unsigned char* buf,

int len,

Local<Array> ret,

bool need_type = false) {

HandleScope handle_scope(env->isolate());

struct ares_srv_reply* srv_start;

int status = ares_parse_srv_reply(buf, len, &srv_start);

if (status != ARES_SUCCESS)

return status;

ares_srv_reply* current = srv_start;

int offset = ret->Length();

for (uint32_t i = 0; current != nullptr; ++i, current = current->next) {

Local<Object> srv_record = Object::New(env->isolate());

srv_record->Set(env->context(),

env->name_string(),

OneByteString(env->isolate(), current->host)).Check();

srv_record->Set(env->context(),

env->port_string(),

Integer::New(env->isolate(), current->port)).Check();

srv_record->Set(env->context(),

env->priority_string(),

Integer::New(env->isolate(), current->priority)).Check();

srv_record->Set(env->context(),

env->weight_string(),

Integer::New(env->isolate(), current->weight)).Check();

if (need_type)

srv_record->Set(env->context(),

env->type_string(),

env->dns_srv_string()).Check();

ret->Set(env->context(), i + offset, srv_record).Check();

}

ares_free_data(srv_start);

return ARES_SUCCESS;

}

int ParseNaptrReply(

Environment* env,

const unsigned char* buf,

int len,

Local<Array> ret,

bool need_type = false) {

HandleScope handle_scope(env->isolate());

ares_naptr_reply* naptr_start;

int status = ares_parse_naptr_reply(buf, len, &naptr_start);

if (status != ARES_SUCCESS)

return status;

ares_naptr_reply* current = naptr_start;

int offset = ret->Length();

for (uint32_t i = 0; current != nullptr; ++i, current = current->next) {

Local<Object> naptr_record = Object::New(env->isolate());

naptr_record->Set(env->context(),

env->flags_string(),

OneByteString(env->isolate(), current->flags)).Check();

naptr_record->Set(env->context(),

env->service_string(),

OneByteString(env->isolate(),

current->service)).Check();

naptr_record->Set(env->context(),

env->regexp_string(),

OneByteString(env->isolate(),

current->regexp)).Check();

naptr_record->Set(env->context(),

env->replacement_string(),

OneByteString(env->isolate(),

current->replacement)).Check();

naptr_record->Set(env->context(),

env->order_string(),

Integer::New(env->isolate(), current->order)).Check();

naptr_record->Set(env->context(),

env->preference_string(),

Integer::New(env->isolate(),

current->preference)).Check();

if (need_type)

naptr_record->Set(env->context(),

env->type_string(),

env->dns_naptr_string()).Check();

ret->Set(env->context(), i + offset, naptr_record).Check();

}

ares_free_data(naptr_start);

return ARES_SUCCESS;

}

int ParseSoaReply(

Environment* env,

unsigned char* buf,

int len,

Local<Object>* ret) {

EscapableHandleScope handle_scope(env->isolate());

// Manage memory using standardard smart pointer std::unique_tr

struct AresDeleter {

void operator()(char* ptr) const noexcept { ares_free_string(ptr); }

};

using ares_unique_ptr = std::unique_ptr<char[], AresDeleter>;

// Can't use ares_parse_soa_reply() here which can only parse single record

const unsigned int ancount = cares_get_16bit(buf + 6);

unsigned char* ptr = buf + NS_HFIXEDSZ;

char* name_temp = nullptr;

long temp_len; // NOLINT(runtime/int)

int status = ares_expand_name(ptr, buf, len, &name_temp, &temp_len);

if (status != ARES_SUCCESS) {

// returns EBADRESP in case of invalid input

return status == ARES_EBADNAME ? ARES_EBADRESP : status;

}

const ares_unique_ptr name(name_temp);

if (ptr + temp_len + NS_QFIXEDSZ > buf + len) {

return ARES_EBADRESP;

}

ptr += temp_len + NS_QFIXEDSZ;

for (unsigned int i = 0; i < ancount; i++) {

char* rr_name_temp = nullptr;

long rr_temp_len; // NOLINT(runtime/int)

int status2 = ares_expand_name(ptr, buf, len, &rr_name_temp, &rr_temp_len);

if (status2 != ARES_SUCCESS)

return status2 == ARES_EBADNAME ? ARES_EBADRESP : status2;

const ares_unique_ptr rr_name(rr_name_temp);

ptr += rr_temp_len;

if (ptr + NS_RRFIXEDSZ > buf + len) {

return ARES_EBADRESP;

}

const int rr_type = cares_get_16bit(ptr);

const int rr_len = cares_get_16bit(ptr + 8);

ptr += NS_RRFIXEDSZ;

// only need SOA

if (rr_type == ns_t_soa) {

char* nsname_temp = nullptr;

long nsname_temp_len; // NOLINT(runtime/int)

int status3 = ares_expand_name(ptr, buf, len,

&nsname_temp,

&nsname_temp_len);

if (status3 != ARES_SUCCESS) {

return status3 == ARES_EBADNAME ? ARES_EBADRESP : status3;

}

const ares_unique_ptr nsname(nsname_temp);

ptr += nsname_temp_len;

char* hostmaster_temp = nullptr;

long hostmaster_temp_len; // NOLINT(runtime/int)

int status4 = ares_expand_name(ptr, buf, len,

&hostmaster_temp,

&hostmaster_temp_len);

if (status4 != ARES_SUCCESS) {

return status4 == ARES_EBADNAME ? ARES_EBADRESP : status4;

}

const ares_unique_ptr hostmaster(hostmaster_temp);

ptr += hostmaster_temp_len;

if (ptr + 5 * 4 > buf + len) {

return ARES_EBADRESP;

}

const unsigned int serial = nbytes::ReadUint32BE(ptr + 0 * 4);

const unsigned int refresh = nbytes::ReadUint32BE(ptr + 1 * 4);

const unsigned int retry = nbytes::ReadUint32BE(ptr + 2 * 4);

const unsigned int expire = nbytes::ReadUint32BE(ptr + 3 * 4);

const unsigned int minttl = nbytes::ReadUint32BE(ptr + 4 * 4);

Local<Object> soa_record = Object::New(env->isolate());

soa_record->Set(env->context(),

env->nsname_string(),

OneByteString(env->isolate(), nsname.get())).Check();

soa_record->Set(env->context(),

env->hostmaster_string(),

OneByteString(env->isolate(),

hostmaster.get())).Check();

soa_record->Set(env->context(),

env->serial_string(),

Integer::NewFromUnsigned(env->isolate(), serial)).Check();

soa_record->Set(env->context(),

env->refresh_string(),

Integer::New(env->isolate(), refresh)).Check();

soa_record->Set(env->context(),

env->retry_string(),

Integer::New(env->isolate(), retry)).Check();

soa_record->Set(env->context(),

env->expire_string(),

Integer::New(env->isolate(), expire)).Check();

soa_record->Set(env->context(),

env->minttl_string(),

Integer::NewFromUnsigned(env->isolate(), minttl)).Check();

soa_record->Set(env->context(),

env->type_string(),

env->dns_soa_string()).Check();

*ret = handle_scope.Escape(soa_record);

break;

}

ptr += rr_len;

}

return ARES_SUCCESS;

}

} // anonymous namespace

ChannelWrap::ChannelWrap(

Environment* env,

Local<Object> object,

int timeout,

int tries)

: AsyncWrap(env, object, PROVIDER_DNSCHANNEL),

timeout_(timeout),

tries_(tries) {

MakeWeak();

Setup();

}

void ChannelWrap::MemoryInfo(MemoryTracker* tracker) const {

if (timer_handle_ != nullptr)

tracker->TrackField("timer_handle", *timer_handle_);

tracker->TrackField("task_list", task_list_, "NodeAresTask::List");

}

void ChannelWrap::New(const FunctionCallbackInfo<Value>& args) {

CHECK(args.IsConstructCall());

CHECK_EQ(args.Length(), 2);

CHECK(args[0]->IsInt32());

CHECK(args[1]->IsInt32());

const int timeout = args[0].As<Int32>()->Value();

const int tries = args[1].As<Int32>()->Value();

Environment* env = Environment::GetCurrent(args);

new ChannelWrap(env, args.This(), timeout, tries);

}

GetAddrInfoReqWrap::GetAddrInfoReqWrap(Environment* env,

Local<Object> req_wrap_obj,

uint8_t order)

: ReqWrap(env, req_wrap_obj, AsyncWrap::PROVIDER_GETADDRINFOREQWRAP),

order_(order) {}

GetNameInfoReqWrap::GetNameInfoReqWrap(

Environment* env,

Local<Object> req_wrap_obj)

: ReqWrap(env, req_wrap_obj, AsyncWrap::PROVIDER_GETNAMEINFOREQWRAP) {}

/* This is called once per second by loop->timer. It is used to constantly */

/* call back into c-ares for possibly processing timeouts. */

void ChannelWrap::AresTimeout(uv_timer_t* handle) {

ChannelWrap* channel = static_cast<ChannelWrap*>(handle->data);

CHECK_EQ(channel->timer_handle(), handle);

CHECK_EQ(false, channel->task_list()->empty());

ares_process_fd(channel->cares_channel(), ARES_SOCKET_BAD, ARES_SOCKET_BAD);

}

void NodeAresTask::MemoryInfo(MemoryTracker* tracker) const {

tracker->TrackField("channel", channel);

}

/* Allocates and returns a new NodeAresTask */

NodeAresTask* NodeAresTask::Create(ChannelWrap* channel, ares_socket_t sock) {

auto task = new NodeAresTask();

task->channel = channel;

task->sock = sock;

if (uv_poll_init_socket(channel->env()->event_loop(),

&task->poll_watcher, sock) < 0) {

/* This should never happen. */

delete task;

return nullptr;

}

return task;

}

void ChannelWrap::Setup() {

struct ares_options options;

memset(&options, 0, sizeof(options));

options.flags = ARES_FLAG_NOCHECKRESP;

options.sock_state_cb = ares_sockstate_cb;

options.sock_state_cb_data = this;

options.timeout = timeout_;

options.tries = tries_;

int r;

if (!library_inited_) {

Mutex::ScopedLock lock(ares_library_mutex);

// Multiple calls to ares_library_init() increase a reference counter,

// so this is a no-op except for the first call to it.

r = ares_library_init(ARES_LIB_INIT_ALL);

if (r != ARES_SUCCESS)

return env()->ThrowError(ToErrorCodeString(r));

}

/* We do the call to ares_init_option for caller. */

const int optmask =

ARES_OPT_FLAGS | ARES_OPT_TIMEOUTMS |

ARES_OPT_SOCK_STATE_CB | ARES_OPT_TRIES;

r = ares_init_options(&channel_, &options, optmask);

if (r != ARES_SUCCESS) {

Mutex::ScopedLock lock(ares_library_mutex);

ares_library_cleanup();

return env()->ThrowError(ToErrorCodeString(r));

}

library_inited_ = true;

}

void ChannelWrap::StartTimer() {

if (timer_handle_ == nullptr) {

timer_handle_ = new uv_timer_t();

timer_handle_->data = static_cast<void*>(this);

uv_timer_init(env()->event_loop(), timer_handle_);

} else if (uv_is_active(reinterpret_cast<uv_handle_t*>(timer_handle_))) {

return;

}

int timeout = timeout_;

if (timeout == 0) timeout = 1;

if (timeout < 0 || timeout > 1000) timeout = 1000;

uv_timer_start(timer_handle_, AresTimeout, timeout, timeout);

}

void ChannelWrap::CloseTimer() {

if (timer_handle_ == nullptr)

return;

env()->CloseHandle(timer_handle_, [](uv_timer_t* handle) { delete handle; });

timer_handle_ = nullptr;

}

ChannelWrap::~ChannelWrap() {

ares_destroy(channel_);

if (library_inited_) {

Mutex::ScopedLock lock(ares_library_mutex);

// This decreases the reference counter increased by ares_library_init().

ares_library_cleanup();

}

CloseTimer();

}

void ChannelWrap::ModifyActivityQueryCount(int count) {

active_query_count_ += count;

CHECK_GE(active_query_count_, 0);

}

/**

* This function is to check whether current servers are fallback servers

* when cares initialized.

*

* The fallback servers of cares is [ "127.0.0.1" ] with no user additional

* setting.

*/

void ChannelWrap::EnsureServers() {

/* if last query is OK or servers are set by user self, do not check */

if (query_last_ok_ || !is_servers_default_) {

return;

}

ares_addr_port_node* servers = nullptr;

ares_get_servers_ports(channel_, &servers);

/* if no server or multi-servers, ignore */

if (servers == nullptr) return;

if (servers->next != nullptr) {

ares_free_data(servers);

is_servers_default_ = false;

return;

}

/* if the only server is not 127.0.0.1, ignore */

if (servers[0].family != AF_INET ||

servers[0].addr.addr4.s_addr != htonl(INADDR_LOOPBACK) ||

servers[0].tcp_port != 0 ||

servers[0].udp_port != 0) {

ares_free_data(servers);

is_servers_default_ = false;

return;

}

ares_free_data(servers);

servers = nullptr;

/* destroy channel and reset channel */

ares_destroy(channel_);

CloseTimer();

Setup();

}

int AnyTraits::Send(QueryWrap<AnyTraits>* wrap, const char* name) {

wrap->AresQuery(name, ns_c_in, ns_t_any);

return ARES_SUCCESS;

}

int ATraits::Send(QueryWrap<ATraits>* wrap, const char* name) {

wrap->AresQuery(name, ns_c_in, ns_t_a);

return ARES_SUCCESS;

}

int AaaaTraits::Send(QueryWrap<AaaaTraits>* wrap, const char* name) {

wrap->AresQuery(name, ns_c_in, ns_t_aaaa);

return ARES_SUCCESS;

}

int CaaTraits::Send(QueryWrap<CaaTraits>* wrap, const char* name) {

wrap->AresQuery(name, ns_c_in, T_CAA);

return ARES_SUCCESS;

}

int CnameTraits::Send(QueryWrap<CnameTraits>* wrap, const char* name) {

wrap->AresQuery(name, ns_c_in, ns_t_cname);

return ARES_SUCCESS;

}

int MxTraits::Send(QueryWrap<MxTraits>* wrap, const char* name) {

wrap->AresQuery(name, ns_c_in, ns_t_mx);

return ARES_SUCCESS;

}

int NsTraits::Send(QueryWrap<NsTraits>* wrap, const char* name) {

wrap->AresQuery(name, ns_c_in, ns_t_ns);

return ARES_SUCCESS;

}

int TxtTraits::Send(QueryWrap<TxtTraits>* wrap, const char* name) {

wrap->AresQuery(name, ns_c_in, ns_t_txt);

return ARES_SUCCESS;

}

int SrvTraits::Send(QueryWrap<SrvTraits>* wrap, const char* name) {

wrap->AresQuery(name, ns_c_in, ns_t_srv);

return ARES_SUCCESS;

}

int PtrTraits::Send(QueryWrap<PtrTraits>* wrap, const char* name) {

wrap->AresQuery(name, ns_c_in, ns_t_ptr);

return ARES_SUCCESS;

}

int NaptrTraits::Send(QueryWrap<NaptrTraits>* wrap, const char* name) {

wrap->AresQuery(name, ns_c_in, ns_t_naptr);

return ARES_SUCCESS;

}

int SoaTraits::Send(QueryWrap<SoaTraits>* wrap, const char* name) {

wrap->AresQuery(name, ns_c_in, ns_t_soa);

return ARES_SUCCESS;

}

int AnyTraits::Parse(

QueryAnyWrap* wrap,

const std::unique_ptr<ResponseData>& response) {

if (UNLIKELY(response->is_host))

return ARES_EBADRESP;

unsigned char* buf = response->buf.data;

int len = response->buf.size;

Environment* env = wrap->env();

HandleScope handle_scope(env->isolate());

Context::Scope context_scope(env->context());

Local<Array> ret = Array::New(env->isolate());

int type, status, old_count;

/* Parse A records or CNAME records */

ares_addrttl addrttls[256];

int naddrttls = arraysize(addrttls);

type = ns_t_cname_or_a;

status = ParseGeneralReply(env,

buf,

len,

&type,

ret,

addrttls,

&naddrttls);

uint32_t a_count = ret->Length();

if (status != ARES_SUCCESS && status != ARES_ENODATA)

return status;

if (type == ns_t_a) {

CHECK_EQ(static_cast<uint32_t>(naddrttls), a_count);

for (uint32_t i = 0; i < a_count; i++) {

Local<Object> obj = Object::New(env->isolate());

obj->Set(env->context(),

env->address_string(),

ret->Get(env->context(), i).ToLocalChecked()).Check();

obj->Set(env->context(),

env->ttl_string(),

Integer::NewFromUnsigned(

env->isolate(), addrttls[i].ttl)).Check();

obj->Set(env->context(),

env->type_string(),

env->dns_a_string()).Check();

ret->Set(env->context(), i, obj).Check();

}

} else {

for (uint32_t i = 0; i < a_count; i++) {

Local<Object> obj = Object::New(env->isolate());

obj->Set(env->context(),

env->value_string(),

ret->Get(env->context(), i).ToLocalChecked()).Check();

obj->Set(env->context(),

env->type_string(),

env->dns_cname_string()).Check();

ret->Set(env->context(), i, obj).Check();

}

}

/* Parse AAAA records */

ares_addr6ttl addr6ttls[256];

int naddr6ttls = arraysize(addr6ttls);

type = ns_t_aaaa;

status = ParseGeneralReply(env,

buf,

len,

&type,

ret,

addr6ttls,

&naddr6ttls);

uint32_t aaaa_count = ret->Length() - a_count;

if (status != ARES_SUCCESS && status != ARES_ENODATA)

return status;

CHECK_EQ(aaaa_count, static_cast<uint32_t>(naddr6ttls));

CHECK_EQ(ret->Length(), a_count + aaaa_count);

for (uint32_t i = a_count; i < ret->Length(); i++) {

Local<Object> obj = Object::New(env->isolate());

obj->Set(env->context(),

env->address_string(),

ret->Get(env->context(), i).ToLocalChecked()).Check();

obj->Set(env->context(),

env->ttl_string(),

Integer::NewFromUnsigned(

env->isolate(), addr6ttls[i - a_count].ttl)).Check();

obj->Set(env->context(),

env->type_string(),

env->dns_aaaa_string()).Check();

ret->Set(env->context(), i, obj).Check();

}

/* Parse MX records */

status = ParseMxReply(env, buf, len, ret, true);

if (status != ARES_SUCCESS && status != ARES_ENODATA)

return status;

/* Parse NS records */

type = ns_t_ns;

old_count = ret->Length();

status = ParseGeneralReply(env, buf, len, &type, ret);

if (status != ARES_SUCCESS && status != ARES_ENODATA)

return status;

for (uint32_t i = old_count; i < ret->Length(); i++) {

Local<Object> obj = Object::New(env->isolate());

obj->Set(env->context(),

env->value_string(),