icinga2/lib/remote/httpserverconnection.cpp
Michael Friedrich a208f7baf0 HttpServerConnection: Prefer error codes over Boost exceptions
When run within a coroutine, exceptions on Windows may influence
bad behaviour here. Instead, we'll check for the error code
and extract the message from memory. In contrast to exceptions
which are stored on the stack frame and then return, this costs
a little more memory but simplifies the logic.

This doesn't fix the linked issue, but is related to the analysis.

refs #7431
2019-09-06 10:06:17 +02:00

576 lines
15 KiB
C++

/* Icinga 2 | (c) 2012 Icinga GmbH | GPLv2+ */
#include "remote/httpserverconnection.hpp"
#include "remote/httphandler.hpp"
#include "remote/httputility.hpp"
#include "remote/apilistener.hpp"
#include "remote/apifunction.hpp"
#include "remote/jsonrpc.hpp"
#include "base/application.hpp"
#include "base/base64.hpp"
#include "base/convert.hpp"
#include "base/configtype.hpp"
#include "base/defer.hpp"
#include "base/exception.hpp"
#include "base/io-engine.hpp"
#include "base/logger.hpp"
#include "base/objectlock.hpp"
#include "base/timer.hpp"
#include "base/tlsstream.hpp"
#include "base/utility.hpp"
#include <limits>
#include <memory>
#include <stdexcept>
#include <boost/asio/io_service.hpp>
#include <boost/asio/spawn.hpp>
#include <boost/beast/core.hpp>
#include <boost/beast/http.hpp>
#include <boost/system/system_error.hpp>
#include <boost/thread/once.hpp>
using namespace icinga;
auto const l_ServerHeader ("Icinga/" + Application::GetAppVersion());
HttpServerConnection::HttpServerConnection(const String& identity, bool authenticated, const std::shared_ptr<AsioTlsStream>& stream)
: HttpServerConnection(identity, authenticated, stream, IoEngine::Get().GetIoService())
{
}
HttpServerConnection::HttpServerConnection(const String& identity, bool authenticated, const std::shared_ptr<AsioTlsStream>& stream, boost::asio::io_service& io)
: m_Stream(stream), m_Seen(Utility::GetTime()), m_IoStrand(io), m_ShuttingDown(false), m_HasStartedStreaming(false),
m_CheckLivenessTimer(io)
{
if (authenticated) {
m_ApiUser = ApiUser::GetByClientCN(identity);
}
{
std::ostringstream address;
auto endpoint (stream->lowest_layer().remote_endpoint());
address << '[' << endpoint.address() << "]:" << endpoint.port();
m_PeerAddress = address.str();
}
}
void HttpServerConnection::Start()
{
namespace asio = boost::asio;
HttpServerConnection::Ptr keepAlive (this);
asio::spawn(m_IoStrand, [this, keepAlive](asio::yield_context yc) { ProcessMessages(yc); });
asio::spawn(m_IoStrand, [this, keepAlive](asio::yield_context yc) { CheckLiveness(yc); });
}
void HttpServerConnection::Disconnect()
{
namespace asio = boost::asio;
HttpServerConnection::Ptr keepAlive (this);
asio::spawn(m_IoStrand, [this, keepAlive](asio::yield_context yc) {
if (!m_ShuttingDown) {
m_ShuttingDown = true;
Log(LogInformation, "HttpServerConnection")
<< "HTTP client disconnected (from " << m_PeerAddress << ")";
boost::system::error_code ec;
m_Stream->next_layer().async_shutdown(yc[ec]);
m_Stream->lowest_layer().shutdown(m_Stream->lowest_layer().shutdown_both, ec);
m_Stream->lowest_layer().cancel(ec);
m_CheckLivenessTimer.cancel();
auto listener (ApiListener::GetInstance());
if (listener) {
CpuBoundWork removeHttpClient (yc);
listener->RemoveHttpClient(this);
}
}
});
}
void HttpServerConnection::StartStreaming()
{
namespace asio = boost::asio;
m_HasStartedStreaming = true;
HttpServerConnection::Ptr keepAlive (this);
asio::spawn(m_IoStrand, [this, keepAlive](asio::yield_context yc) {
if (!m_ShuttingDown) {
char buf[128];
asio::mutable_buffer readBuf (buf, 128);
boost::system::error_code ec;
do {
m_Stream->async_read_some(readBuf, yc[ec]);
} while (!ec);
Disconnect();
}
});
}
bool HttpServerConnection::Disconnected()
{
return m_ShuttingDown;
}
static inline
bool EnsureValidHeaders(
AsioTlsStream& stream,
boost::beast::flat_buffer& buf,
boost::beast::http::parser<true, boost::beast::http::string_body>& parser,
boost::beast::http::response<boost::beast::http::string_body>& response,
boost::asio::yield_context& yc
)
{
namespace http = boost::beast::http;
bool httpError = true;
try {
boost::system::error_code ec;
http::async_read_header(stream, buf, parser, yc[ec]);
if (ec) {
/**
* Unfortunately there's no way to tell an HTTP protocol error
* from an error on a lower layer:
*
* <https://github.com/boostorg/beast/issues/643>
*/
throw std::invalid_argument(ec.message());
}
httpError = false;
switch (parser.get().version()) {
case 10:
case 11:
break;
default:
throw std::invalid_argument("Unsupported HTTP version");
}
} catch (const std::invalid_argument& ex) {
response.result(http::status::bad_request);
if (!httpError && parser.get()[http::field::accept] == "application/json") {
HttpUtility::SendJsonBody(response, nullptr, new Dictionary({
{ "error", 400 },
{ "status", String("Bad Request: ") + ex.what() }
}));
} else {
response.set(http::field::content_type, "text/html");
response.body() = String("<h1>Bad Request</h1><p><pre>") + ex.what() + "</pre></p>";
response.set(http::field::content_length, response.body().size());
}
response.set(http::field::connection, "close");
boost::system::error_code ec;
http::async_write(stream, response, yc[ec]);
stream.async_flush(yc[ec]);
return false;
}
return true;
}
static inline
void HandleExpect100(
AsioTlsStream& stream,
boost::beast::http::request<boost::beast::http::string_body>& request,
boost::asio::yield_context& yc
)
{
namespace http = boost::beast::http;
if (request[http::field::expect] == "100-continue") {
http::response<http::string_body> response;
response.result(http::status::continue_);
boost::system::error_code ec;
http::async_write(stream, response, yc[ec]);
stream.async_flush(yc[ec]);
}
}
static inline
bool HandleAccessControl(
AsioTlsStream& stream,
boost::beast::http::request<boost::beast::http::string_body>& request,
boost::beast::http::response<boost::beast::http::string_body>& response,
boost::asio::yield_context& yc
)
{
namespace http = boost::beast::http;
auto listener (ApiListener::GetInstance());
if (listener) {
auto headerAllowOrigin (listener->GetAccessControlAllowOrigin());
if (headerAllowOrigin) {
CpuBoundWork allowOriginHeader (yc);
auto allowedOrigins (headerAllowOrigin->ToSet<String>());
if (!allowedOrigins.empty()) {
auto& origin (request[http::field::origin]);
if (allowedOrigins.find(origin.to_string()) != allowedOrigins.end()) {
response.set(http::field::access_control_allow_origin, origin);
}
allowOriginHeader.Done();
response.set(http::field::access_control_allow_credentials, "true");
if (request.method() == http::verb::options && !request[http::field::access_control_request_method].empty()) {
response.result(http::status::ok);
response.set(http::field::access_control_allow_methods, "GET, POST, PUT, DELETE");
response.set(http::field::access_control_allow_headers, "Authorization, X-HTTP-Method-Override");
response.body() = "Preflight OK";
response.set(http::field::content_length, response.body().size());
response.set(http::field::connection, "close");
boost::system::error_code ec;
http::async_write(stream, response, yc[ec]);
stream.async_flush(yc[ec]);
return false;
}
}
}
}
return true;
}
static inline
bool EnsureAcceptHeader(
AsioTlsStream& stream,
boost::beast::http::request<boost::beast::http::string_body>& request,
boost::beast::http::response<boost::beast::http::string_body>& response,
boost::asio::yield_context& yc
)
{
namespace http = boost::beast::http;
if (request.method() != http::verb::get && request[http::field::accept] != "application/json") {
response.result(http::status::bad_request);
response.set(http::field::content_type, "text/html");
response.body() = "<h1>Accept header is missing or not set to 'application/json'.</h1>";
response.set(http::field::content_length, response.body().size());
response.set(http::field::connection, "close");
boost::system::error_code ec;
http::async_write(stream, response, yc[ec]);
stream.async_flush(yc[ec]);
return false;
}
return true;
}
static inline
bool EnsureAuthenticatedUser(
AsioTlsStream& stream,
boost::beast::http::request<boost::beast::http::string_body>& request,
ApiUser::Ptr& authenticatedUser,
boost::beast::http::response<boost::beast::http::string_body>& response,
boost::asio::yield_context& yc
)
{
namespace http = boost::beast::http;
if (!authenticatedUser) {
Log(LogWarning, "HttpServerConnection")
<< "Unauthorized request: " << request.method_string() << ' ' << request.target();
response.result(http::status::unauthorized);
response.set(http::field::www_authenticate, "Basic realm=\"Icinga 2\"");
response.set(http::field::connection, "close");
if (request[http::field::accept] == "application/json") {
HttpUtility::SendJsonBody(response, nullptr, new Dictionary({
{ "error", 401 },
{ "status", "Unauthorized. Please check your user credentials." }
}));
} else {
response.set(http::field::content_type, "text/html");
response.body() = "<h1>Unauthorized. Please check your user credentials.</h1>";
response.set(http::field::content_length, response.body().size());
}
boost::system::error_code ec;
http::async_write(stream, response, yc[ec]);
stream.async_flush(yc[ec]);
return false;
}
return true;
}
static inline
bool EnsureValidBody(
AsioTlsStream& stream,
boost::beast::flat_buffer& buf,
boost::beast::http::parser<true, boost::beast::http::string_body>& parser,
ApiUser::Ptr& authenticatedUser,
boost::beast::http::response<boost::beast::http::string_body>& response,
boost::asio::yield_context& yc
)
{
namespace http = boost::beast::http;
{
size_t maxSize = 1024 * 1024;
Array::Ptr permissions = authenticatedUser->GetPermissions();
if (permissions) {
CpuBoundWork evalPermissions (yc);
ObjectLock olock(permissions);
for (const Value& permissionInfo : permissions) {
String permission;
if (permissionInfo.IsObjectType<Dictionary>()) {
permission = static_cast<Dictionary::Ptr>(permissionInfo)->Get("permission");
} else {
permission = permissionInfo;
}
static std::vector<std::pair<String, size_t>> specialContentLengthLimits {
{ "config/modify", 512 * 1024 * 1024 }
};
for (const auto& limitInfo : specialContentLengthLimits) {
if (limitInfo.second <= maxSize) {
continue;
}
if (Utility::Match(permission, limitInfo.first)) {
maxSize = limitInfo.second;
}
}
}
}
parser.body_limit(maxSize);
}
boost::system::error_code ec;
http::async_read(stream, buf, parser, yc[ec]);
if (ec) {
/**
* Unfortunately there's no way to tell an HTTP protocol error
* from an error on a lower layer:
*
* <https://github.com/boostorg/beast/issues/643>
*/
response.result(http::status::bad_request);
if (parser.get()[http::field::accept] == "application/json") {
HttpUtility::SendJsonBody(response, nullptr, new Dictionary({
{ "error", 400 },
{ "status", String("Bad Request: ") + ec.message() }
}));
} else {
response.set(http::field::content_type, "text/html");
response.body() = String("<h1>Bad Request</h1><p><pre>") + ec.message() + "</pre></p>";
response.set(http::field::content_length, response.body().size());
}
response.set(http::field::connection, "close");
http::async_write(stream, response, yc[ec]);
stream.async_flush(yc[ec]);
return false;
}
return true;
}
static inline
bool ProcessRequest(
AsioTlsStream& stream,
boost::beast::http::request<boost::beast::http::string_body>& request,
ApiUser::Ptr& authenticatedUser,
boost::beast::http::response<boost::beast::http::string_body>& response,
HttpServerConnection& server,
bool& hasStartedStreaming,
boost::asio::yield_context& yc
)
{
namespace http = boost::beast::http;
try {
CpuBoundWork handlingRequest (yc);
HttpHandler::ProcessRequest(stream, authenticatedUser, request, response, yc, server);
} catch (const std::exception& ex) {
if (hasStartedStreaming) {
return false;
}
http::response<http::string_body> response;
HttpUtility::SendJsonError(response, nullptr, 500, "Unhandled exception" , DiagnosticInformation(ex));
boost::system::error_code ec;
http::async_write(stream, response, yc[ec]);
stream.async_flush(yc[ec]);
return true;
}
if (hasStartedStreaming) {
return false;
}
boost::system::error_code ec;
http::async_write(stream, response, yc[ec]);
stream.async_flush(yc[ec]);
return true;
}
void HttpServerConnection::ProcessMessages(boost::asio::yield_context yc)
{
namespace beast = boost::beast;
namespace http = beast::http;
Defer disconnect ([this]() { Disconnect(); });
try {
beast::flat_buffer buf;
for (;;) {
m_Seen = Utility::GetTime();
http::parser<true, http::string_body> parser;
http::response<http::string_body> response;
parser.header_limit(1024 * 1024);
parser.body_limit(-1);
response.set(http::field::server, l_ServerHeader);
if (!EnsureValidHeaders(*m_Stream, buf, parser, response, yc)) {
break;
}
m_Seen = Utility::GetTime();
auto& request (parser.get());
{
auto method (http::string_to_verb(request["X-Http-Method-Override"]));
if (method != http::verb::unknown) {
request.method(method);
}
}
HandleExpect100(*m_Stream, request, yc);
auto authenticatedUser (m_ApiUser);
if (!authenticatedUser) {
CpuBoundWork fetchingAuthenticatedUser (yc);
authenticatedUser = ApiUser::GetByAuthHeader(request[http::field::authorization].to_string());
}
Log(LogInformation, "HttpServerConnection")
<< "Request: " << request.method_string() << ' ' << request.target()
<< " (from " << m_PeerAddress
<< "), user: " << (authenticatedUser ? authenticatedUser->GetName() : "<unauthenticated>")
<< ", agent: " << request[http::field::user_agent] << ")."; //operator[] - Returns the value for a field, or "" if it does not exist.
if (!HandleAccessControl(*m_Stream, request, response, yc)) {
break;
}
if (!EnsureAcceptHeader(*m_Stream, request, response, yc)) {
break;
}
if (!EnsureAuthenticatedUser(*m_Stream, request, authenticatedUser, response, yc)) {
break;
}
if (!EnsureValidBody(*m_Stream, buf, parser, authenticatedUser, response, yc)) {
break;
}
m_Seen = std::numeric_limits<decltype(m_Seen)>::max();
if (!ProcessRequest(*m_Stream, request, authenticatedUser, response, *this, m_HasStartedStreaming, yc)) {
break;
}
if (request.version() != 11 || request[http::field::connection] == "close") {
break;
}
}
} catch (const std::exception& ex) {
if (!m_ShuttingDown) {
Log(LogCritical, "HttpServerConnection")
<< "Unhandled exception while processing HTTP request: " << ex.what();
}
}
}
void HttpServerConnection::CheckLiveness(boost::asio::yield_context yc)
{
boost::system::error_code ec;
for (;;) {
m_CheckLivenessTimer.expires_from_now(boost::posix_time::seconds(5));
m_CheckLivenessTimer.async_wait(yc[ec]);
if (m_ShuttingDown) {
break;
}
if (m_Seen < Utility::GetTime() - 10) {
Log(LogInformation, "HttpServerConnection")
<< "No messages for HTTP connection have been received in the last 10 seconds.";
Disconnect();
break;
}
}
}