lts/src/inspector_socket.cc
#include "inspector_socket.h"
#define NODE_EXPERIMENTAL_HTTP
#include "http_parser_adaptor.h"
#include "util-inl.h"
#define NODE_WANT_INTERNALS 1
#include "base64.h"
#include "openssl/sha.h" // Sha-1 hash
#include <cstring>
#include <map>
#define ACCEPT_KEY_LENGTH base64_encoded_size(20)
#define DUMP_READS 0
#define DUMP_WRITES 0
namespace node {
namespace inspector {
class TcpHolder {
public:
static void DisconnectAndDispose(TcpHolder* holder);
using Pointer = DeleteFnPtr<TcpHolder, DisconnectAndDispose>;
static Pointer Accept(uv_stream_t* server,
InspectorSocket::DelegatePointer delegate);
void SetHandler(ProtocolHandler* handler);
int WriteRaw(const std::vector<char>& buffer, uv_write_cb write_cb);
uv_tcp_t* tcp() {
return &tcp_;
}
InspectorSocket::Delegate* delegate();
private:
static TcpHolder* From(void* handle) {
return node::ContainerOf(&TcpHolder::tcp_,
reinterpret_cast<uv_tcp_t*>(handle));
}
static void OnClosed(uv_handle_t* handle);
static void OnDataReceivedCb(uv_stream_t* stream, ssize_t nread,
const uv_buf_t* buf);
explicit TcpHolder(InspectorSocket::DelegatePointer delegate);
~TcpHolder() = default;
void ReclaimUvBuf(const uv_buf_t* buf, ssize_t read);
uv_tcp_t tcp_;
const InspectorSocket::DelegatePointer delegate_;
ProtocolHandler* handler_;
std::vector<char> buffer;
};
class ProtocolHandler {
public:
ProtocolHandler(InspectorSocket* inspector, TcpHolder::Pointer tcp);
virtual void AcceptUpgrade(const std::string& accept_key) = 0;
virtual void OnData(std::vector<char>* data) = 0;
virtual void OnEof() = 0;
virtual void Write(const std::vector<char> data) = 0;
virtual void CancelHandshake() = 0;
std::string GetHost() const;
InspectorSocket* inspector() {
return inspector_;
}
virtual void Shutdown() = 0;
protected:
virtual ~ProtocolHandler() = default;
int WriteRaw(const std::vector<char>& buffer, uv_write_cb write_cb);
InspectorSocket::Delegate* delegate();
InspectorSocket* const inspector_;
TcpHolder::Pointer tcp_;
};
namespace {
#if DUMP_READS || DUMP_WRITES
static void dump_hex(const char* buf, size_t len) {
const char* ptr = buf;
const char* end = ptr + len;
const char* cptr;
char c;
int i;
while (ptr < end) {
cptr = ptr;
for (i = 0; i < 16 && ptr < end; i++) {
printf("%2.2X ", static_cast<unsigned char>(*(ptr++)));
}
for (i = 72 - (i * 4); i > 0; i--) {
printf(" ");
}
for (i = 0; i < 16 && cptr < end; i++) {
c = *(cptr++);
printf("%c", (c > 0x19) ? c : '.');
}
printf("\n");
}
printf("\n\n");
}
#endif
class WriteRequest {
public:
WriteRequest(ProtocolHandler* handler, const std::vector<char>& buffer)
: handler(handler)
, storage(buffer)
, req(uv_write_t())
, buf(uv_buf_init(storage.data(), storage.size())) {}
static WriteRequest* from_write_req(uv_write_t* req) {
return node::ContainerOf(&WriteRequest::req, req);
}
static void Cleanup(uv_write_t* req, int status) {
delete WriteRequest::from_write_req(req);
}
ProtocolHandler* const handler;
std::vector<char> storage;
uv_write_t req;
uv_buf_t buf;
};
void allocate_buffer(uv_handle_t* stream, size_t len, uv_buf_t* buf) {
*buf = uv_buf_init(new char[len], len);
}
static void remove_from_beginning(std::vector<char>* buffer, size_t count) {
buffer->erase(buffer->begin(), buffer->begin() + count);
}
static const char CLOSE_FRAME[] = {'\x88', '\x00'};
enum ws_decode_result {
FRAME_OK, FRAME_INCOMPLETE, FRAME_CLOSE, FRAME_ERROR
};
static void generate_accept_string(const std::string& client_key,
char (*buffer)[ACCEPT_KEY_LENGTH]) {
// Magic string from websockets spec.
static const char ws_magic[] = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
std::string input(client_key + ws_magic);
char hash[SHA_DIGEST_LENGTH];
SHA1(reinterpret_cast<const unsigned char*>(&input[0]), input.size(),
reinterpret_cast<unsigned char*>(hash));
node::base64_encode(hash, sizeof(hash), *buffer, sizeof(*buffer));
}
static std::string TrimPort(const std::string& host) {
size_t last_colon_pos = host.rfind(':');
if (last_colon_pos == std::string::npos)
return host;
size_t bracket = host.rfind(']');
if (bracket == std::string::npos || last_colon_pos > bracket)
return host.substr(0, last_colon_pos);
return host;
}
static bool IsIPAddress(const std::string& host) {
if (host.length() >= 4 && host.front() == '[' && host.back() == ']')
return true;
int quads = 0;
for (char c : host) {
if (c == '.')
quads++;
else if (!isdigit(c))
return false;
}
return quads == 3;
}
// Constants for hybi-10 frame format.
typedef int OpCode;
const OpCode kOpCodeContinuation = 0x0;
const OpCode kOpCodeText = 0x1;
const OpCode kOpCodeBinary = 0x2;
const OpCode kOpCodeClose = 0x8;
const OpCode kOpCodePing = 0x9;
const OpCode kOpCodePong = 0xA;
const unsigned char kFinalBit = 0x80;
const unsigned char kReserved1Bit = 0x40;
const unsigned char kReserved2Bit = 0x20;
const unsigned char kReserved3Bit = 0x10;
const unsigned char kOpCodeMask = 0xF;
const unsigned char kMaskBit = 0x80;
const unsigned char kPayloadLengthMask = 0x7F;
const size_t kMaxSingleBytePayloadLength = 125;
const size_t kTwoBytePayloadLengthField = 126;
const size_t kEightBytePayloadLengthField = 127;
const size_t kMaskingKeyWidthInBytes = 4;
static std::vector<char> encode_frame_hybi17(const std::vector<char>& message) {
std::vector<char> frame;
OpCode op_code = kOpCodeText;
frame.push_back(kFinalBit | op_code);
const size_t data_length = message.size();
if (data_length <= kMaxSingleBytePayloadLength) {
frame.push_back(static_cast<char>(data_length));
} else if (data_length <= 0xFFFF) {
frame.push_back(kTwoBytePayloadLengthField);
frame.push_back((data_length & 0xFF00) >> 8);
frame.push_back(data_length & 0xFF);
} else {
frame.push_back(kEightBytePayloadLengthField);
char extended_payload_length[8];
size_t remaining = data_length;
// Fill the length into extended_payload_length in the network byte order.
for (int i = 0; i < 8; ++i) {
extended_payload_length[7 - i] = remaining & 0xFF;
remaining >>= 8;
}
frame.insert(frame.end(), extended_payload_length,
extended_payload_length + 8);
CHECK_EQ(0, remaining);
}
frame.insert(frame.end(), message.begin(), message.end());
return frame;
}
static ws_decode_result decode_frame_hybi17(const std::vector<char>& buffer,
bool client_frame,
int* bytes_consumed,
std::vector<char>* output,
bool* compressed) {
*bytes_consumed = 0;
if (buffer.size() < 2)
return FRAME_INCOMPLETE;
auto it = buffer.begin();
unsigned char first_byte = *it++;
unsigned char second_byte = *it++;
bool final = (first_byte & kFinalBit) != 0;
bool reserved1 = (first_byte & kReserved1Bit) != 0;
bool reserved2 = (first_byte & kReserved2Bit) != 0;
bool reserved3 = (first_byte & kReserved3Bit) != 0;
int op_code = first_byte & kOpCodeMask;
bool masked = (second_byte & kMaskBit) != 0;
*compressed = reserved1;
if (!final || reserved2 || reserved3)
return FRAME_ERROR; // Only compression extension is supported.
bool closed = false;
switch (op_code) {
case kOpCodeClose:
closed = true;
break;
case kOpCodeText:
break;
case kOpCodeBinary: // We don't support binary frames yet.
case kOpCodeContinuation: // We don't support binary frames yet.
case kOpCodePing: // We don't support binary frames yet.
case kOpCodePong: // We don't support binary frames yet.
default:
return FRAME_ERROR;
}
// In Hybi-17 spec client MUST mask its frame.
if (client_frame && !masked) {
return FRAME_ERROR;
}
uint64_t payload_length64 = second_byte & kPayloadLengthMask;
if (payload_length64 > kMaxSingleBytePayloadLength) {
int extended_payload_length_size;
if (payload_length64 == kTwoBytePayloadLengthField) {
extended_payload_length_size = 2;
} else if (payload_length64 == kEightBytePayloadLengthField) {
extended_payload_length_size = 8;
} else {
return FRAME_ERROR;
}
if ((buffer.end() - it) < extended_payload_length_size)
return FRAME_INCOMPLETE;
payload_length64 = 0;
for (int i = 0; i < extended_payload_length_size; ++i) {
payload_length64 <<= 8;
payload_length64 |= static_cast<unsigned char>(*it++);
}
}
static const uint64_t max_payload_length = 0x7FFFFFFFFFFFFFFFull;
static const size_t max_length = SIZE_MAX;
if (payload_length64 > max_payload_length ||
payload_length64 > max_length - kMaskingKeyWidthInBytes) {
// WebSocket frame length too large.
return FRAME_ERROR;
}
size_t payload_length = static_cast<size_t>(payload_length64);
if (buffer.size() - kMaskingKeyWidthInBytes < payload_length)
return FRAME_INCOMPLETE;
std::vector<char>::const_iterator masking_key = it;
std::vector<char>::const_iterator payload = it + kMaskingKeyWidthInBytes;
for (size_t i = 0; i < payload_length; ++i) // Unmask the payload.
output->insert(output->end(),
payload[i] ^ masking_key[i % kMaskingKeyWidthInBytes]);
size_t pos = it + kMaskingKeyWidthInBytes + payload_length - buffer.begin();
*bytes_consumed = pos;
return closed ? FRAME_CLOSE : FRAME_OK;
}
// WS protocol
class WsHandler : public ProtocolHandler {
public:
WsHandler(InspectorSocket* inspector, TcpHolder::Pointer tcp)
: ProtocolHandler(inspector, std::move(tcp)),
OnCloseSent(&WsHandler::WaitForCloseReply),
OnCloseRecieved(&WsHandler::CloseFrameReceived),
dispose_(false) { }
void AcceptUpgrade(const std::string& accept_key) override { }
void CancelHandshake() override {}
void OnEof() override {
tcp_.reset();
if (dispose_)
delete this;
}
void OnData(std::vector<char>* data) override {
// 1. Parse.
int processed = 0;
do {
processed = ParseWsFrames(*data);
// 2. Fix the data size & length
if (processed > 0) {
remove_from_beginning(data, processed);
}
} while (processed > 0 && !data->empty());
}
void Write(const std::vector<char> data) override {
std::vector<char> output = encode_frame_hybi17(data);
WriteRaw(output, WriteRequest::Cleanup);
}
protected:
void Shutdown() override {
if (tcp_) {
dispose_ = true;
SendClose();
} else {
delete this;
}
}
private:
using Callback = void (WsHandler::*)();
static void OnCloseFrameWritten(uv_write_t* req, int status) {
WriteRequest* wr = WriteRequest::from_write_req(req);
WsHandler* handler = static_cast<WsHandler*>(wr->handler);
delete wr;
Callback cb = handler->OnCloseSent;
(handler->*cb)();
}
void WaitForCloseReply() {
OnCloseRecieved = &WsHandler::OnEof;
}
void SendClose() {
WriteRaw(std::vector<char>(CLOSE_FRAME, CLOSE_FRAME + sizeof(CLOSE_FRAME)),
OnCloseFrameWritten);
}
void CloseFrameReceived() {
OnCloseSent = &WsHandler::OnEof;
SendClose();
}
int ParseWsFrames(const std::vector<char>& buffer) {
int bytes_consumed = 0;
std::vector<char> output;
bool compressed = false;
ws_decode_result r = decode_frame_hybi17(buffer,
true /* client_frame */,
&bytes_consumed, &output,
&compressed);
// Compressed frame means client is ignoring the headers and misbehaves
if (compressed || r == FRAME_ERROR) {
OnEof();
bytes_consumed = 0;
} else if (r == FRAME_CLOSE) {
(this->*OnCloseRecieved)();
bytes_consumed = 0;
} else if (r == FRAME_OK) {
delegate()->OnWsFrame(output);
}
return bytes_consumed;
}
Callback OnCloseSent;
Callback OnCloseRecieved;
bool dispose_;
};
// HTTP protocol
class HttpEvent {
public:
HttpEvent(const std::string& path, bool upgrade, bool isGET,
const std::string& ws_key, const std::string& host)
: path(path), upgrade(upgrade), isGET(isGET), ws_key(ws_key),
host(host) { }
std::string path;
bool upgrade;
bool isGET;
std::string ws_key;
std::string host;
};
class HttpHandler : public ProtocolHandler {
public:
explicit HttpHandler(InspectorSocket* inspector, TcpHolder::Pointer tcp)
: ProtocolHandler(inspector, std::move(tcp)),
parsing_value_(false) {
llhttp_init(&parser_, HTTP_REQUEST, &parser_settings);
llhttp_settings_init(&parser_settings);
parser_settings.on_header_field = OnHeaderField;
parser_settings.on_header_value = OnHeaderValue;
parser_settings.on_message_complete = OnMessageComplete;
parser_settings.on_url = OnPath;
}
void AcceptUpgrade(const std::string& accept_key) override {
char accept_string[ACCEPT_KEY_LENGTH];
generate_accept_string(accept_key, &accept_string);
const char accept_ws_prefix[] = "HTTP/1.1 101 Switching Protocols\r\n"
"Upgrade: websocket\r\n"
"Connection: Upgrade\r\n"
"Sec-WebSocket-Accept: ";
const char accept_ws_suffix[] = "\r\n\r\n";
std::vector<char> reply(accept_ws_prefix,
accept_ws_prefix + sizeof(accept_ws_prefix) - 1);
reply.insert(reply.end(), accept_string,
accept_string + sizeof(accept_string));
reply.insert(reply.end(), accept_ws_suffix,
accept_ws_suffix + sizeof(accept_ws_suffix) - 1);
if (WriteRaw(reply, WriteRequest::Cleanup) >= 0) {
inspector_->SwitchProtocol(new WsHandler(inspector_, std::move(tcp_)));
} else {
tcp_.reset();
}
}
void CancelHandshake() override {
const char HANDSHAKE_FAILED_RESPONSE[] =
"HTTP/1.0 400 Bad Request\r\n"
"Content-Type: text/html; charset=UTF-8\r\n\r\n"
"WebSockets request was expected\r\n";
WriteRaw(std::vector<char>(HANDSHAKE_FAILED_RESPONSE,
HANDSHAKE_FAILED_RESPONSE + sizeof(HANDSHAKE_FAILED_RESPONSE) - 1),
ThenCloseAndReportFailure);
}
void OnEof() override {
tcp_.reset();
}
void OnData(std::vector<char>* data) override {
parser_errno_t err;
err = llhttp_execute(&parser_, data->data(), data->size());
if (err == HPE_PAUSED_UPGRADE) {
err = HPE_OK;
llhttp_resume_after_upgrade(&parser_);
}
data->clear();
if (err != HPE_OK) {
CancelHandshake();
}
// Event handling may delete *this
std::vector<HttpEvent> events;
std::swap(events, events_);
for (const HttpEvent& event : events) {
if (!IsAllowedHost(event.host) || !event.isGET) {
CancelHandshake();
return;
} else if (!event.upgrade) {
delegate()->OnHttpGet(event.host, event.path);
} else if (event.ws_key.empty()) {
CancelHandshake();
return;
} else {
delegate()->OnSocketUpgrade(event.host, event.path, event.ws_key);
}
}
}
void Write(const std::vector<char> data) override {
WriteRaw(data, WriteRequest::Cleanup);
}
protected:
void Shutdown() override {
delete this;
}
private:
static void ThenCloseAndReportFailure(uv_write_t* req, int status) {
ProtocolHandler* handler = WriteRequest::from_write_req(req)->handler;
WriteRequest::Cleanup(req, status);
handler->inspector()->SwitchProtocol(nullptr);
}
static int OnHeaderValue(parser_t* parser, const char* at, size_t length) {
HttpHandler* handler = From(parser);
handler->parsing_value_ = true;
handler->headers_[handler->current_header_].append(at, length);
return 0;
}
static int OnHeaderField(parser_t* parser, const char* at, size_t length) {
HttpHandler* handler = From(parser);
if (handler->parsing_value_) {
handler->parsing_value_ = false;
handler->current_header_.clear();
}
handler->current_header_.append(at, length);
return 0;
}
static int OnPath(parser_t* parser, const char* at, size_t length) {
HttpHandler* handler = From(parser);
handler->path_.append(at, length);
return 0;
}
static HttpHandler* From(parser_t* parser) {
return node::ContainerOf(&HttpHandler::parser_, parser);
}
static int OnMessageComplete(parser_t* parser) {
// Event needs to be fired after the parser is done.
HttpHandler* handler = From(parser);
handler->events_.emplace_back(handler->path_,
parser->upgrade,
parser->method == HTTP_GET,
handler->HeaderValue("Sec-WebSocket-Key"),
handler->HeaderValue("Host"));
handler->path_ = "";
handler->parsing_value_ = false;
handler->headers_.clear();
handler->current_header_ = "";
return 0;
}
std::string HeaderValue(const std::string& header) const {
bool header_found = false;
std::string value;
for (const auto& header_value : headers_) {
if (node::StringEqualNoCaseN(header_value.first.data(), header.data(),
header.length())) {
if (header_found)
return "";
value = header_value.second;
header_found = true;
}
}
return value;
}
bool IsAllowedHost(const std::string& host_with_port) const {
std::string host = TrimPort(host_with_port);
return host.empty() || IsIPAddress(host)
|| node::StringEqualNoCase(host.data(), "localhost")
|| node::StringEqualNoCase(host.data(), "localhost6");
}
bool parsing_value_;
parser_t parser_;
parser_settings_t parser_settings;
std::vector<HttpEvent> events_;
std::string current_header_;
std::map<std::string, std::string> headers_;
std::string path_;
};
} // namespace
// Any protocol
ProtocolHandler::ProtocolHandler(InspectorSocket* inspector,
TcpHolder::Pointer tcp)
: inspector_(inspector), tcp_(std::move(tcp)) {
CHECK_NOT_NULL(tcp_);
tcp_->SetHandler(this);
}
int ProtocolHandler::WriteRaw(const std::vector<char>& buffer,
uv_write_cb write_cb) {
return tcp_->WriteRaw(buffer, write_cb);
}
InspectorSocket::Delegate* ProtocolHandler::delegate() {
return tcp_->delegate();
}
std::string ProtocolHandler::GetHost() const {
char ip[INET6_ADDRSTRLEN];
sockaddr_storage addr;
int len = sizeof(addr);
int err = uv_tcp_getsockname(tcp_->tcp(),
reinterpret_cast<struct sockaddr*>(&addr),
&len);
if (err != 0)
return "";
if (addr.ss_family == AF_INET6) {
const sockaddr_in6* v6 = reinterpret_cast<const sockaddr_in6*>(&addr);
err = uv_ip6_name(v6, ip, sizeof(ip));
} else {
const sockaddr_in* v4 = reinterpret_cast<const sockaddr_in*>(&addr);
err = uv_ip4_name(v4, ip, sizeof(ip));
}
if (err != 0)
return "";
return ip;
}
// RAII uv_tcp_t wrapper
TcpHolder::TcpHolder(InspectorSocket::DelegatePointer delegate)
: tcp_(),
delegate_(std::move(delegate)),
handler_(nullptr) { }
// static
TcpHolder::Pointer TcpHolder::Accept(
uv_stream_t* server,
InspectorSocket::DelegatePointer delegate) {
TcpHolder* result = new TcpHolder(std::move(delegate));
uv_stream_t* tcp = reinterpret_cast<uv_stream_t*>(&result->tcp_);
int err = uv_tcp_init(server->loop, &result->tcp_);
if (err == 0) {
err = uv_accept(server, tcp);
}
if (err == 0) {
err = uv_read_start(tcp, allocate_buffer, OnDataReceivedCb);
}
if (err == 0) {
return TcpHolder::Pointer(result);
} else {
delete result;
return nullptr;
}
}
void TcpHolder::SetHandler(ProtocolHandler* handler) {
handler_ = handler;
}
int TcpHolder::WriteRaw(const std::vector<char>& buffer, uv_write_cb write_cb) {
#if DUMP_WRITES
printf("%s (%ld bytes):\n", __FUNCTION__, buffer.size());
dump_hex(buffer.data(), buffer.size());
printf("\n");
#endif
// Freed in write_request_cleanup
WriteRequest* wr = new WriteRequest(handler_, buffer);
uv_stream_t* stream = reinterpret_cast<uv_stream_t*>(&tcp_);
int err = uv_write(&wr->req, stream, &wr->buf, 1, write_cb);
if (err < 0)
delete wr;
return err < 0;
}
InspectorSocket::Delegate* TcpHolder::delegate() {
return delegate_.get();
}
// static
void TcpHolder::OnClosed(uv_handle_t* handle) {
delete From(handle);
}
void TcpHolder::OnDataReceivedCb(uv_stream_t* tcp, ssize_t nread,
const uv_buf_t* buf) {
#if DUMP_READS
if (nread >= 0) {
printf("%s (%ld bytes)\n", __FUNCTION__, nread);
dump_hex(buf->base, nread);
} else {
printf("[%s:%d] %s\n", __FUNCTION__, __LINE__, uv_err_name(nread));
}
#endif
TcpHolder* holder = From(tcp);
holder->ReclaimUvBuf(buf, nread);
if (nread < 0 || nread == UV_EOF) {
holder->handler_->OnEof();
} else {
holder->handler_->OnData(&holder->buffer);
}
}
// static
void TcpHolder::DisconnectAndDispose(TcpHolder* holder) {
uv_handle_t* handle = reinterpret_cast<uv_handle_t*>(&holder->tcp_);
uv_close(handle, OnClosed);
}
void TcpHolder::ReclaimUvBuf(const uv_buf_t* buf, ssize_t read) {
if (read > 0) {
buffer.insert(buffer.end(), buf->base, buf->base + read);
}
delete[] buf->base;
}
InspectorSocket::~InspectorSocket() = default;
// static
void InspectorSocket::Shutdown(ProtocolHandler* handler) {
handler->Shutdown();
}
// static
InspectorSocket::Pointer InspectorSocket::Accept(uv_stream_t* server,
DelegatePointer delegate) {
auto tcp = TcpHolder::Accept(server, std::move(delegate));
if (tcp) {
InspectorSocket* inspector = new InspectorSocket();
inspector->SwitchProtocol(new HttpHandler(inspector, std::move(tcp)));
return InspectorSocket::Pointer(inspector);
} else {
return InspectorSocket::Pointer(nullptr);
}
}
void InspectorSocket::AcceptUpgrade(const std::string& ws_key) {
protocol_handler_->AcceptUpgrade(ws_key);
}
void InspectorSocket::CancelHandshake() {
protocol_handler_->CancelHandshake();
}
std::string InspectorSocket::GetHost() {
return protocol_handler_->GetHost();
}
void InspectorSocket::SwitchProtocol(ProtocolHandler* handler) {
protocol_handler_.reset(std::move(handler));
}
void InspectorSocket::Write(const char* data, size_t len) {
protocol_handler_->Write(std::vector<char>(data, data + len));
}
} // namespace inspector
} // namespace node