ClickHouse/dbms/programs/server/MySQLHandler.cpp
2020-01-22 22:52:04 +05:30

389 lines
17 KiB
C++

#include <Common/config.h>
#include "MySQLHandler.h"
#include <limits>
#include <ext/scope_guard.h>
#include <Columns/ColumnVector.h>
#include <Common/config_version.h>
#include <Common/NetException.h>
#include <Common/OpenSSLHelpers.h>
#include <Core/MySQLProtocol.h>
#include <Core/NamesAndTypes.h>
#include <DataStreams/copyData.h>
#include <Interpreters/executeQuery.h>
#include <IO/ReadBufferFromPocoSocket.h>
#include <IO/ReadBufferFromString.h>
#include <IO/WriteBufferFromPocoSocket.h>
#include <Storages/IStorage.h>
#include <boost/algorithm/string/replace.hpp>
#if USE_POCO_NETSSL
#include <Poco/Net/SecureStreamSocket.h>
#include <Poco/Net/SSLManager.h>
#include <Poco/Crypto/CipherFactory.h>
#include <Poco/Crypto/RSAKey.h>
#endif
namespace DB
{
using namespace MySQLProtocol;
#if USE_POCO_NETSSL
using Poco::Net::SecureStreamSocket;
using Poco::Net::SSLManager;
#endif
namespace ErrorCodes
{
extern const int MYSQL_CLIENT_INSUFFICIENT_CAPABILITIES;
extern const int OPENSSL_ERROR;
extern const int SUPPORT_IS_DISABLED;
}
MySQLHandler::MySQLHandler(IServer & server_, const Poco::Net::StreamSocket & socket_,
bool ssl_enabled, size_t connection_id_)
: Poco::Net::TCPServerConnection(socket_)
, server(server_)
, log(&Poco::Logger::get("MySQLHandler"))
, connection_context(server.context())
, connection_id(connection_id_)
, auth_plugin(new MySQLProtocol::Authentication::Native41())
{
server_capability_flags = CLIENT_PROTOCOL_41 | CLIENT_SECURE_CONNECTION | CLIENT_PLUGIN_AUTH | CLIENT_PLUGIN_AUTH_LENENC_CLIENT_DATA | CLIENT_CONNECT_WITH_DB | CLIENT_DEPRECATE_EOF;
if (ssl_enabled)
server_capability_flags |= CLIENT_SSL;
}
void MySQLHandler::run()
{
connection_context.makeSessionContext();
connection_context.setDefaultFormat("MySQLWire");
in = std::make_shared<ReadBufferFromPocoSocket>(socket());
out = std::make_shared<WriteBufferFromPocoSocket>(socket());
packet_sender = std::make_shared<PacketSender>(*in, *out, connection_context.mysql.sequence_id);
try
{
Handshake handshake(server_capability_flags, connection_id, VERSION_STRING + String("-") + VERSION_NAME, auth_plugin->getName(), auth_plugin->getAuthPluginData());
packet_sender->sendPacket<Handshake>(handshake, true);
LOG_TRACE(log, "Sent handshake");
HandshakeResponse handshake_response;
finishHandshake(handshake_response);
connection_context.mysql.client_capabilities = handshake_response.capability_flags;
if (handshake_response.max_packet_size)
connection_context.mysql.max_packet_size = handshake_response.max_packet_size;
if (!connection_context.mysql.max_packet_size)
connection_context.mysql.max_packet_size = MAX_PACKET_LENGTH;
LOG_TRACE(log, "Capabilities: " << handshake_response.capability_flags
<< ", max_packet_size: "
<< handshake_response.max_packet_size
<< ", character_set: "
<< static_cast<int>(handshake_response.character_set)
<< ", user: "
<< handshake_response.username
<< ", auth_response length: "
<< handshake_response.auth_response.length()
<< ", database: "
<< handshake_response.database
<< ", auth_plugin_name: "
<< handshake_response.auth_plugin_name);
client_capability_flags = handshake_response.capability_flags;
if (!(client_capability_flags & CLIENT_PROTOCOL_41))
throw Exception("Required capability: CLIENT_PROTOCOL_41.", ErrorCodes::MYSQL_CLIENT_INSUFFICIENT_CAPABILITIES);
authenticate(handshake_response.username, handshake_response.auth_plugin_name, handshake_response.auth_response);
try
{
if (!handshake_response.database.empty())
connection_context.setCurrentDatabase(handshake_response.database);
connection_context.setCurrentQueryId("");
}
catch (const Exception & exc)
{
log->log(exc);
packet_sender->sendPacket(ERR_Packet(exc.code(), "00000", exc.message()), true);
}
OK_Packet ok_packet(0, handshake_response.capability_flags, 0, 0, 0);
packet_sender->sendPacket(ok_packet, true);
while (true)
{
packet_sender->resetSequenceId();
PacketPayloadReadBuffer payload = packet_sender->getPayload();
char command = 0;
payload.readStrict(command);
// For commands which are executed without MemoryTracker.
LimitReadBuffer limited_payload(payload, 10000, true, "too long MySQL packet.");
LOG_DEBUG(log, "Received command: " << static_cast<int>(static_cast<unsigned char>(command)) << ". Connection id: " << connection_id << ".");
try
{
switch (command)
{
case COM_QUIT:
return;
case COM_INIT_DB:
comInitDB(limited_payload);
break;
case COM_QUERY:
comQuery(payload);
break;
case COM_FIELD_LIST:
comFieldList(limited_payload);
break;
case COM_PING:
comPing();
break;
default:
throw Exception(Poco::format("Command %d is not implemented.", command), ErrorCodes::NOT_IMPLEMENTED);
}
}
catch (const NetException & exc)
{
log->log(exc);
throw;
}
catch (const Exception & exc)
{
log->log(exc);
packet_sender->sendPacket(ERR_Packet(exc.code(), "00000", exc.message()), true);
}
}
}
catch (const Poco::Exception & exc)
{
log->log(exc);
}
}
/** Reads 3 bytes, finds out whether it is SSLRequest or HandshakeResponse packet, starts secure connection, if it is SSLRequest.
* Reading is performed from socket instead of ReadBuffer to prevent reading part of SSL handshake.
* If we read it from socket, it will be impossible to start SSL connection using Poco. Size of SSLRequest packet payload is 32 bytes, thus we can read at most 36 bytes.
*/
void MySQLHandler::finishHandshake(MySQLProtocol::HandshakeResponse & packet)
{
size_t packet_size = PACKET_HEADER_SIZE + SSL_REQUEST_PAYLOAD_SIZE;
/// Buffer for SSLRequest or part of HandshakeResponse.
char buf[packet_size];
size_t pos = 0;
/// Reads at least count and at most packet_size bytes.
auto read_bytes = [this, &buf, &pos, &packet_size](size_t count) -> void {
while (pos < count)
{
int ret = socket().receiveBytes(buf + pos, packet_size - pos);
if (ret == 0)
{
throw Exception("Cannot read all data. Bytes read: " + std::to_string(pos) + ". Bytes expected: 3.", ErrorCodes::CANNOT_READ_ALL_DATA);
}
pos += ret;
}
};
read_bytes(3); /// We can find out whether it is SSLRequest of HandshakeResponse by first 3 bytes.
size_t payload_size = unalignedLoad<uint32_t>(buf) & 0xFFFFFFu;
LOG_TRACE(log, "payload size: " << payload_size);
if (payload_size == SSL_REQUEST_PAYLOAD_SIZE)
{
finishHandshakeSSL(packet_size, buf, pos, read_bytes, packet);
}
else
{
/// Reading rest of HandshakeResponse.
packet_size = PACKET_HEADER_SIZE + payload_size;
WriteBufferFromOwnString buf_for_handshake_response;
buf_for_handshake_response.write(buf, pos);
copyData(*packet_sender->in, buf_for_handshake_response, packet_size - pos);
ReadBufferFromString payload(buf_for_handshake_response.str());
payload.ignore(PACKET_HEADER_SIZE);
packet.readPayload(payload);
packet_sender->sequence_id++;
}
}
void MySQLHandler::authenticate(const String & user_name, const String & auth_plugin_name, const String & initial_auth_response)
{
try
{
// For compatibility with JavaScript MySQL client, Native41 authentication plugin is used when possible (if password is specified using double SHA1). Otherwise SHA256 plugin is used.
auto user = connection_context.getUser(user_name);
const DB::Authentication::Type user_auth_type = user->authentication.getType();
if (user_auth_type != DB::Authentication::DOUBLE_SHA1_PASSWORD && user_auth_type != DB::Authentication::PLAINTEXT_PASSWORD && user_auth_type != DB::Authentication::NO_PASSWORD)
{
authPluginSSL();
}
std::optional<String> auth_response = auth_plugin_name == auth_plugin->getName() ? std::make_optional<String>(initial_auth_response) : std::nullopt;
auth_plugin->authenticate(user_name, auth_response, connection_context, packet_sender, secure_connection, socket().peerAddress());
}
catch (const Exception & exc)
{
LOG_ERROR(log, "Authentication for user " << user_name << " failed.");
packet_sender->sendPacket(ERR_Packet(exc.code(), "00000", exc.message()), true);
throw;
}
LOG_INFO(log, "Authentication for user " << user_name << " succeeded.");
}
void MySQLHandler::comInitDB(ReadBuffer & payload)
{
String database;
readStringUntilEOF(database, payload);
LOG_DEBUG(log, "Setting current database to " << database);
connection_context.setCurrentDatabase(database);
packet_sender->sendPacket(OK_Packet(0, client_capability_flags, 0, 0, 1), true);
}
void MySQLHandler::comFieldList(ReadBuffer & payload)
{
ComFieldList packet;
packet.readPayload(payload);
String database = connection_context.getCurrentDatabase();
StoragePtr tablePtr = connection_context.getTable(database, packet.table);
for (const NameAndTypePair & column: tablePtr->getColumns().getAll())
{
ColumnDefinition column_definition(
database, packet.table, packet.table, column.name, column.name, CharacterSet::binary, 100, ColumnType::MYSQL_TYPE_STRING, 0, 0
);
packet_sender->sendPacket(column_definition);
}
packet_sender->sendPacket(OK_Packet(0xfe, client_capability_flags, 0, 0, 0), true);
}
void MySQLHandler::comPing()
{
packet_sender->sendPacket(OK_Packet(0x0, client_capability_flags, 0, 0, 0), true);
}
static bool isFederatedServerSetupCommand(const String & query);
void MySQLHandler::comQuery(ReadBuffer & payload)
{
String query = String(payload.position(), payload.buffer().end());
// This is a workaround in order to support adding ClickHouse to MySQL using federated server.
// As Clickhouse doesn't support these statements, we just send OK packet in response.
if (isFederatedServerSetupCommand(query))
{
packet_sender->sendPacket(OK_Packet(0x00, client_capability_flags, 0, 0, 0), true);
}
else
{
bool with_output = false;
std::function<void(const String &, const String &)> set_content_type_and_format = [&with_output](const String &, const String &) -> void
{
with_output = true;
};
String replacement_query = "select ''";
bool should_replace = false;
// Translate query from MySQL to ClickHouse.
// This is a temporary workaround until ClickHouse supports the syntax "@@var_name".
if (query == "select @@version_comment limit 1") // MariaDB client starts session with that query
{
should_replace = true;
}
// This is a workaround in order to support adding ClickHouse to MySQL using federated server.
if (0 == strncasecmp("SHOW TABLE STATUS LIKE", query.c_str(), 22))
{
should_replace = true;
replacement_query = boost::replace_all_copy(query, "SHOW TABLE STATUS LIKE ", show_table_status_replacement_query);
}
ReadBufferFromString replacement(replacement_query);
Context query_context = connection_context;
executeQuery(should_replace ? replacement : payload, *out, true, query_context, set_content_type_and_format, {});
if (!with_output)
packet_sender->sendPacket(OK_Packet(0x00, client_capability_flags, 0, 0, 0), true);
}
}
void MySQLHandler::authPluginSSL()
{
throw Exception("ClickHouse was built without SSL support. Try specifying password using double SHA1 in users.xml.", ErrorCodes::SUPPORT_IS_DISABLED);
}
void MySQLHandler::finishHandshakeSSL([[maybe_unused]] size_t packet_size, [[maybe_unused]] char * buf, [[maybe_unused]] size_t pos, [[maybe_unused]] std::function<void(size_t)> read_bytes, [[maybe_unused]] MySQLProtocol::HandshakeResponse & packet)
{
throw Exception("Client requested SSL, while it is disabled.", ErrorCodes::SUPPORT_IS_DISABLED);
}
#if USE_SSL && USE_POCO_NETSSL
MySQLHandlerSSL::MySQLHandlerSSL(IServer & server_, const Poco::Net::StreamSocket & socket_, bool ssl_enabled, size_t connection_id_, RSA & public_key_, RSA & private_key_)
: MySQLHandler(server_, socket_, ssl_enabled, connection_id_)
, public_key(public_key_)
, private_key(private_key_)
{}
void MySQLHandlerSSL::authPluginSSL()
{
auth_plugin = std::make_unique<MySQLProtocol::Authentication::Sha256Password>(public_key, private_key, log);
}
void MySQLHandlerSSL::finishHandshakeSSL(size_t packet_size, char * buf, size_t pos, std::function<void(size_t)> read_bytes, MySQLProtocol::HandshakeResponse & packet)
{
read_bytes(packet_size); /// Reading rest SSLRequest.
SSLRequest ssl_request;
ReadBufferFromMemory payload(buf, pos);
payload.ignore(PACKET_HEADER_SIZE);
ssl_request.readPayload(payload);
connection_context.mysql.client_capabilities = ssl_request.capability_flags;
connection_context.mysql.max_packet_size = ssl_request.max_packet_size ? ssl_request.max_packet_size : MAX_PACKET_LENGTH;
secure_connection = true;
ss = std::make_shared<SecureStreamSocket>(SecureStreamSocket::attach(socket(), SSLManager::instance().defaultServerContext()));
in = std::make_shared<ReadBufferFromPocoSocket>(*ss);
out = std::make_shared<WriteBufferFromPocoSocket>(*ss);
connection_context.mysql.sequence_id = 2;
packet_sender = std::make_shared<PacketSender>(*in, *out, connection_context.mysql.sequence_id);
packet_sender->max_packet_size = connection_context.mysql.max_packet_size;
packet_sender->receivePacket(packet); /// Reading HandshakeResponse from secure socket.
}
#endif
static bool isFederatedServerSetupCommand(const String & query)
{
return 0 == strncasecmp("SET NAMES", query.c_str(), 9) || 0 == strncasecmp("SET character_set_results", query.c_str(), 25)
|| 0 == strncasecmp("SET FOREIGN_KEY_CHECKS", query.c_str(), 22) || 0 == strncasecmp("SET AUTOCOMMIT", query.c_str(), 14)
|| 0 == strncasecmp("SET SESSION TRANSACTION ISOLATION LEVEL", query.c_str(), 39);
}
const String MySQLHandler::show_table_status_replacement_query("SELECT"
" name AS Name,"
" engine AS Engine,"
" '10' AS Version,"
" 'Dynamic' AS Row_format,"
" 0 AS Rows,"
" 0 AS Avg_row_length,"
" 0 AS Data_length,"
" 0 AS Max_data_length,"
" 0 AS Index_length,"
" 0 AS Data_free,"
" 'NULL' AS Auto_increment,"
" metadata_modification_time AS Create_time,"
" metadata_modification_time AS Update_time,"
" metadata_modification_time AS Check_time,"
" 'utf8_bin' AS Collation,"
" 'NULL' AS Checksum,"
" '' AS Create_options,"
" '' AS Comment"
" FROM system.tables"
" WHERE name LIKE ");
}