Keeps FTP's control and passive/active data connections alive. More...

#include <ftp_mock_server.h>

Inheritance diagram for proto_fuzzer::FtpMockServer:

Public Member Functions
	FtpMockServer ()
	Begin without a borrowed protobuf or open socketpairs.
	~FtpMockServer () override
	Release server-owned descriptors and socketpair peers after curl has returned its client fds.
void	ObserveState () override
	Retain protocol outcomes in coverage and introspector builds.
const std::string &	control_transcript () const
	Expose the bounded command capture from the most recent drive so tests can verify FTP states without coupling assertions to curl debug output.
const std::string &	uploaded_data () const
	Expose a bounded upload prefix from the most recent drive while continuing to drain all client bytes, so test observability cannot create backpressure.
std::size_t	opened_data_connection_count () const
	Report how many bounded data scripts curl assigned to passive or active transfer sockets, rather than how many scripts the protobuf contains.
std::size_t	active_pollset_probe_count () const
	Report how many requested zero-timeout multi-poll probes ran during the most recent drive.
Public Member Functions inherited from proto_fuzzer::MockServerBase
virtual	~MockServerBase ()
	Out-of-line destructor so MockConnection can stay forward-declared in the base header (its complete type is only needed where unique_ptr is instantiated for destruction).
virtual void	Install (CURL *easy)
	Install the common OPENSOCKETFUNCTION / OPENSOCKETDATA / SOCKOPTFUNCTION callbacks on 'easy'.
virtual void	ConfigureRequestData (ScenarioRequestData *request_data)
	Bind protocol-specific work to the request-data callbacks after their per-scenario state has been constructed.
CURLcode	DriveScenario (CURL *easy, const curl::fuzzer::proto::Scenario &scenario)
	Run 'scenario' to completion on 'easy': allocate a multi, attach 'easy', delegate protocol-specific work to RunLoop, consume its completion message, and clean up.
virtual CURLcode	DriveEasyScenario (CURL *easy, const curl::fuzzer::proto::Scenario &scenario, bool use_events=false)
	Run through the public easy entrypoint when a protocol mock can preload all peer work before curl takes control.
virtual ConnectOnlyRunStats	DriveConnectOnlyScenario (CURL *easy, const curl::fuzzer::proto::Scenario &scenario)
	Establish a CONNECT_ONLY transport, then perform bounded direct I/O.
void	SetMultiObserver (MultiObserver observer)
	Register an observer invoked with the live multi handle after 'easy' is attached and before the drive loop starts.
MockConnection *	connection ()

Protected Member Functions
virtual std::unique_ptr< MockConnection >	CreateConnection ()
	Create the default plaintext transport for the control and passive data connections.
virtual bool	SupportsActiveMode () const
	Plain FTP can create and publish a real loopback listener for PORT/EPRT.
void	ReleaseConnections ()
	Close every server-owned transport before the borrowed scenario or a subclass transport disappears.
void	ObserveIncomingData (const unsigned char *data, std::size_t size) override
	Retain decoded client bytes for the control parser.
curl_socket_t	HandleOpenSocket (curlsocktype purpose=CURLSOCKTYPE_IPCXN, struct curl_sockaddr *address=nullptr) override
	Allocate one control socket followed by a bounded sequence of passive data sockets, or a real listener when CURLOPT_FTPPORT selected active mode.
SocketSetupDisposition	GetSocketSetupDisposition (curl_socket_t curlfd, curlsocktype purpose) const override
	Control/passive sockets are connected AF_UNIX pairs, while active FTP needs curl to bind and listen on the real TCP descriptor returned by OpenActiveListener.
void	RunLoop (CURLM multi, CURL easy, const curl::fuzzer::proto::Scenario &scenario) override
	Alternate curl transitions with immediate peer service until the transfer completes or deterministic idle/operation caps win.
Protected Member Functions inherited from proto_fuzzer::MockServerBase
	MockServerBase (MultiDrivePolicy drive_policy=MultiDrivePolicy::kPerform)
	Construct an empty base instance with a fixed multi-drive policy.
virtual void	HandleDetachedMulti (CurlMultiPtr multi)
	Dispose of or retain the multi after its easy handle has been removed.
MultiSocketDriver *	multi_socket_driver ()
	Expose the callback state installed for the current socket-action drive.
std::size_t	additional_handle_cleanup_count () const
void	ResumeResponseIfRequested (CURL *easy)
	Resume receive-side callback output at one bounded drive boundary when the dedicated API plan requested it.
void	ApplyPendingBackpressure ()
	Apply the BackpressureConfig cached by DriveScenario to the new connection_.

Additional Inherited Members
Public Types inherited from proto_fuzzer::MockServerBase
using	MultiObserver = std::function<void(CURLM*)>
	Callback type used to publish the driving multi handle to observers.
Static Protected Member Functions inherited from proto_fuzzer::MockServerBase
static int	WaitOnMultiFdset (CURLM multi, CURLMcode rc)
	Wait on curl's fdset with a short timeout.
static void	ProbeMultiPollset (CURLM *multi)
	Ask curl to construct and inspect its connection-filter pollset without waiting.
static bool	MultiPollsetWantsWrite (CURLM *multi, curl_socket_t socket)
	Inspect one socket's current writable interest through curl's public multi fdset API.
static bool	UsesTimedDrive (const curl::fuzzer::proto::Scenario &scenario)
	Treat a non-default BackpressureConfig as an explicit request for the slower, timed drive policy.
Protected Attributes inherited from proto_fuzzer::MockServerBase
std::unique_ptr< MockConnection >	connection_
	The per-scenario MockConnection, lazily created by HandleOpenSocket().
int	pending_recv_buf_bytes_
	Cached SO_RCVBUF/SO_SNDBUF setting in bytes.
std::size_t	pending_drain_limit_
	Cached per-call DrainIncoming byte budget.
MultiSocketDriver *	multi_socket_driver_
	Non-owning pointer into DriveScenario's stack.
std::size_t	additional_handle_cleanup_count_
	Number of application-created handles, excluding the caller's parent, successfully removed from the current multi and cleaned up.
bool	resume_response_
	True only for an API-plan multi drive with its one-shot write callback.
MultiObserver	multi_observer_
	Observer receiving the live multi handle at the start of a drive.
Static Protected Attributes inherited from proto_fuzzer::MockServerBase
static constexpr int	kMaxDriveIterations = 512
	Hard operation budget for one scenario.
static constexpr int	kMaxIdleIterations = 8
	Consecutive no-progress budget for ordinary scenarios.
static constexpr int	kMaxTimedIdleIterations = 256
	Explicit backpressure scenarios get a larger idle budget and may use the short timed wait above.

Detailed Description

Keeps FTP's control and passive/active data connections alive.

FTP cannot use the generic one-script-per-socket HTTP peer: curl opens a passive data socket while it still needs the control socket for TYPE, SIZE, RETR/STOR, and the final transfer reply. This peer therefore treats Scenario.connection as a command-aligned control script and the bounded subsequent_connections prefix as data streams. Passive transfers use socketpairs; active transfers let curl create a loopback listener and have the mock connect to it after observing the generated PORT/EPRT command. Both directions are observed after transport decoding, so a subclass can replace every socketpair with a TLS carrier without changing the FTP state machine. All work remains in-process and non-waiting so malformed scripts terminate by operation budget or EOF rather than by curl's FTP response timeout.

Definition at line 43 of file ftp_mock_server.h.

Constructor & Destructor Documentation

◆ FtpMockServer()

proto_fuzzer::FtpMockServer::FtpMockServer ( )

Begin without a borrowed protobuf or open socketpairs.

RunLoop borrows a Scenario only for the synchronous DriveScenario call in which socket callbacks can run. Keeping all session state in the object avoids process globals that could leak one libFuzzer iteration's protocol position into the next.

Definition at line 37 of file ftp_mock_server.cc.

◆ ~FtpMockServer()

proto_fuzzer::FtpMockServer::~FtpMockServer ( )

override

Release server-owned descriptors and socketpair peers after curl has returned its client fds.

Loopback peers are unique_ptr-owned transports; the out-of-line destructor also permits MockConnection to remain forward-declared in the header.

Definition at line 52 of file ftp_mock_server.cc.

Member Function Documentation

◆ active_pollset_probe_count()

std::size_t proto_fuzzer::FtpMockServer::active_pollset_probe_count ( ) const

Report how many requested zero-timeout multi-poll probes ran during the most recent drive.

RunLoop increments this only after a successful perform turn while curl still owns an active transfer and the control socket is open.

Returns: Number of active FTP pollset probes in the previous drive.

Definition at line 112 of file ftp_mock_server.cc.

◆ control_transcript()

const std::string & proto_fuzzer::FtpMockServer::control_transcript ( ) const

Expose the bounded command capture from the most recent drive so tests can verify FTP states without coupling assertions to curl debug output.

The capture is bounded independently of protocol processing.

Returns: A prefix of complete control commands, including line endings.

Definition at line 94 of file ftp_mock_server.cc.

◆ CreateConnection()

std::unique_ptr< MockConnection > proto_fuzzer::FtpMockServer::CreateConnection ( )

protectedvirtual

Create the default plaintext transport for the control and passive data connections.

The implicit-TLS FTPS subclass overrides this factory while retaining the command parser and channel bookkeeping.

Returns: A new socketpair-backed connection.

Reimplemented in proto_fuzzer::FtpsMockServer.

Definition at line 58 of file ftp_mock_server.cc.

◆ GetSocketSetupDisposition()

SocketSetupDisposition proto_fuzzer::FtpMockServer::GetSocketSetupDisposition	(	curl_socket_t	curlfd,
		curlsocktype	purpose ) const

overrideprotectedvirtual

Control/passive sockets are connected AF_UNIX pairs, while active FTP needs curl to bind and listen on the real TCP descriptor returned by OpenActiveListener.

The descriptor identity is recorded when opened, so this decision never depends on a sandbox-sensitive getsockopt call.

Parameters

curlfd	Descriptor returned by HandleOpenSocket.
purpose	Role curl assigned to the descriptor.

Returns: Whether curl must perform its normal socket setup.

Reimplemented from proto_fuzzer::MockServerBase.

Definition at line 205 of file ftp_mock_server.cc.

◆ HandleOpenSocket()

curl_socket_t proto_fuzzer::FtpMockServer::HandleOpenSocket	(	curlsocktype	purpose = CURLSOCKTYPE_IPCXN,
		struct curl_sockaddr *	address = nullptr )

overrideprotectedvirtual

Allocate one control socket followed by a bounded sequence of passive data sockets, or a real listener when CURLOPT_FTPPORT selected active mode.

Data is intentionally not preloaded here: curl has not yet sent the command that determines whether the stream is a listing, download, or upload.

Parameters

purpose	Socket role requested by curl.
address	Mutable description of curl's intended destination.

Returns: Client descriptor for the selected FTP channel, or CURL_SOCKET_BAD when no channel is available.

Implements proto_fuzzer::MockServerBase.

Definition at line 259 of file ftp_mock_server.cc.

◆ ObserveIncomingData()

void proto_fuzzer::FtpMockServer::ObserveIncomingData	(	const unsigned char *	data,
		std::size_t	size )

overrideprotectedvirtual

Retain decoded client bytes for the control parser.

Data channels install their own observer so upload bodies are routed without mixing them into the command stream.

Parameters

data	First decoded byte.
size	Number of bytes available at data.

Implements proto_fuzzer::IncomingDataObserver.

Definition at line 71 of file ftp_mock_server.cc.

◆ opened_data_connection_count()

std::size_t proto_fuzzer::FtpMockServer::opened_data_connection_count ( ) const

Report how many bounded data scripts curl assigned to passive or active transfer sockets, rather than how many scripts the protobuf contains.

Tests can distinguish control-only failures from paths that reached data setup.

Returns: Number of bounded data scripts assigned to a transfer socket.

Definition at line 105 of file ftp_mock_server.cc.

◆ ReleaseConnections()

void proto_fuzzer::FtpMockServer::ReleaseConnections ( )

protected

Close every server-owned transport before the borrowed scenario or a subclass transport disappears.

The out-of-line definition keeps MockConnection complete here while the header only forward-declares it.

Definition at line 117 of file ftp_mock_server.cc.

◆ RunLoop()

void proto_fuzzer::FtpMockServer::RunLoop	(	CURLM *	multi,
		CURL *	easy,
		const curl::fuzzer::proto::Scenario &	scenario )

overrideprotectedvirtual

Alternate curl transitions with immediate peer service until the transfer completes or deterministic idle/operation caps win.

No select(), poll(), or sleep is needed: every transport is in-process, and malformed scripts are terminated by half-close after the bounded loop.

Parameters

multi	Multi handle containing easy.
easy	Easy handle already installed on this mock.
scenario	Control and passive-data scripts to borrow.

Implements proto_fuzzer::MockServerBase.

Definition at line 795 of file ftp_mock_server.cc.

◆ SupportsActiveMode()

bool proto_fuzzer::FtpMockServer::SupportsActiveMode ( ) const

protectedvirtual

Plain FTP can create and publish a real loopback listener for PORT/EPRT.

Subclasses that only expose wrapped socketpairs override this to keep the active-mode request from producing an unusable plaintext endpoint.

Returns: true for the plaintext FTP peer.

Reimplemented in proto_fuzzer::FtpsMockServer.

Definition at line 64 of file ftp_mock_server.cc.

◆ uploaded_data()

const std::string & proto_fuzzer::FtpMockServer::uploaded_data ( ) const

Expose a bounded upload prefix from the most recent drive while continuing to drain all client bytes, so test observability cannot create backpressure.

Returns: Bytes curl sent over passive upload connections.

Definition at line 99 of file ftp_mock_server.cc.

The documentation for this class was generated from the following files:

proto_fuzzer/ftp_mock_server.h
proto_fuzzer/ftp_mock_server.cc

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ FtpMockServer()

◆ ~FtpMockServer()

Member Function Documentation

◆ active_pollset_probe_count()

◆ control_transcript()

◆ CreateConnection()

◆ GetSocketSetupDisposition()

◆ HandleOpenSocket()

◆ ObserveIncomingData()

◆ opened_data_connection_count()

◆ ReleaseConnections()

◆ RunLoop()

◆ SupportsActiveMode()

◆ uploaded_data()