Raw socket handler for ssh protocol driver. More...

#include <SshSocketHandler.h>

Inheritance diagram for Hypertable::SshSocketHandler:

Collaboration diagram for Hypertable::SshSocketHandler:

Public Member Functions
	SshSocketHandler (const std::string &hostname)
	Constructor. More...

virtual	~SshSocketHandler ()
	Destructor. More...

virtual bool	handle (int sd, int events)
	Socket event handler function. More...

virtual void	deregister (int sd)
	Deregisters socket. More...

virtual int	poll_interest (int sd)
	Returns current polling interest. More...

void	log_callback (ssh_session session, int priority, const char *message)
	Writes log messages to logging output collector. More...

int	auth_callback (const char prompt, char buf, size_t len, int echo, int verify)
	libssh authorization callback. More...

void	connect_status_callback (float status)
	libssh connection status callback. More...

void	global_request_callback (ssh_session session, ssh_message message)
	libssh global request callback. More...

void	set_exit_status (int exit_status)
	libssh exit status callback This function sets m_command_exit_status to `exit_status`, sets m_command_exit_status_is_set to true, and then signals m_cond. More...

bool	wait_for_connection (std::chrono::system_clock::time_point deadline)
	Waits for connection establishment. More...

bool	issue_command (const std::string &command)
	Asynchronously issues a command. More...

bool	wait_for_command_completion ()
	Waits for command completion. More...

void	cancel ()
	Cancels outstanding connection establishment or command execution. More...

void	dump_log (std::ostream &out)
	Writes collected log messages to output stream. More...

void	set_terminal_output (bool val)
	Tells handler to send collected output subsequent output to terminal If `val` is true, sends any collected stdout or stderr output to terminal and sets m_terminal_output to true which causes any subsequent output collected to be sent to the terminal. More...

const std::string	hostname () const
	Returns hostname. More...

Public Member Functions inherited from Hypertable::RawSocketHandler
virtual	~RawSocketHandler ()
	Destructor. More...

Static Public Member Functions
static void	enable_debug ()
	Enables debug logging output. More...

static void	set_libssh_verbosity (const std::string &value)
	Sets libssh logging verbosity level. More...

Private Member Functions
bool	verify_knownhost ()
	Verifies host with public key method. More...

void	write_to_stdout (const char *output, size_t len)
	Writes output to stdout Writes output to stdout, prefixing each line with '[' hostname ']'. More...

void	write_to_stderr (const char *output, size_t len)
	Writes output to stderr Writes output to stderr, prefixing each line with '[' hostname ']'. More...

bool	socket_has_data ()
	Determines if data available on socket for reading Checks socket descriptor m_sd to see if there is any data available for reading. More...

Private Attributes
std::mutex	m_mutex
	Mutex for serialzing access to members More...

std::condition_variable	m_cond
	Condition variable signalling connection and command completion. More...

Comm *	m_comm
	Pointer to comm layer. More...

std::string	m_hostname
	Name of host to connect to. More...

ssh_session	m_ssh_session
	libssh sesison object More...

CommAddress	m_comm_address
	Address of connection. More...

ssh_channel	m_channel
	libssh channel object More...

int	m_state {}
	Current handler state. More...

int	m_sd {}
	Socket descriptor. More...

int	m_poll_interest {}
	Current polling interest. More...

std::string	m_error
	Error message More...

ssh_callbacks_struct	m_callbacks
	libssh callbacks More...

ssh_channel_callbacks_struct	m_channel_callbacks
	libssh channel callbacks More...

std::string	m_command
	Current command being issued. More...

int	m_command_exit_status {}
	Command exit status. More...

bool	m_command_exit_status_is_set {}
	Flag indicating that the exit status has been set. More...

bool	m_terminal_output {}
	Redirect output to terminal. More...

bool	m_line_prefix_needed_stdout {}
	Line prefix needs to be emitted on next stdout output. More...

bool	m_line_prefix_needed_stderr {}
	Line prefix needs to be emitted on next stderr output. More...

bool	m_cancelled {}
	Flag indicating that outstanding operations should be cancelled. More...

bool	m_channel_is_eof {}
	Flag indicating that current channel is EOF. More...

SshOutputCollector	m_log_collector
	Output collector for logging. More...

SshOutputCollector::Buffer	m_log_buffer {}
	Current logging output buffer. More...

SshOutputCollector	m_stdout_collector
	Output collector for stdout. More...

SshOutputCollector::Buffer	m_stdout_buffer {}
	Current stdout output buffer. More...

SshOutputCollector	m_stderr_collector
	Output collector for stderr. More...

SshOutputCollector::Buffer	m_stderr_buffer {}
	Current stderr output buffer. More...

Static Private Attributes
static bool	ms_debug_enabled {}
	Flag for enabling debugging output. More...

static int	ms_libssh_verbosity {SSH_LOG_PROTOCOL}
	Libssh logging verbosity level. More...

Detailed Description

Raw socket handler for ssh protocol driver.

Definition at line 60 of file SshSocketHandler.h.

Constructor & Destructor Documentation

SshSocketHandler::SshSocketHandler ( const std::string & hostname )

Constructor.

Initializes handler by creating a non-blocking TCP socket and asynchonously connecting to hostname.

Parameters

hostname Name of host to connect to

Definition at line 144 of file SshSocketHandler.cc.

SshSocketHandler::~SshSocketHandler ( )

virtual

Destructor.

Definition at line 202 of file SshSocketHandler.cc.

Member Function Documentation

int SshSocketHandler::auth_callback	(	const char *	prompt,
		char *	buf,
		size_t	len,
		int	echo,
		int	verify
	)

libssh authorization callback.

Currently this function just logs a message and returns -1

Parameters

prompt	Prompt to be displayed.
buf	Buffer to save the password.
len	Length of the buffer.
echo	Enable or disable the echo of what you type.
verify	Should the password be verified?

Returns: -1

Definition at line 539 of file SshSocketHandler.cc.

void SshSocketHandler::cancel ( )

Cancels outstanding connection establishment or command execution.

Sets m_cancelled to true, closes m_channel if it has been opened, closes m_ssh_session if it is open, and then signals m_cond.

Definition at line 632 of file SshSocketHandler.cc.

void SshSocketHandler::connect_status_callback ( float status )

libssh connection status callback.

This method currently does nothing.

Parameters

status Percentage of connection status, going from 0.0 to 1.0

Definition at line 546 of file SshSocketHandler.cc.

void SshSocketHandler::deregister ( int sd )

virtual

Deregisters socket.

Closes m_sd

Parameters

sd	Socket descriptor to deregister

Implements Hypertable::RawSocketHandler.

Definition at line 504 of file SshSocketHandler.cc.

void SshSocketHandler::dump_log ( std::ostream & out )

Writes collected log messages to output stream.

This function adds m_log_buffer to m_log_collector and then iterates over m_log_collector writing each line to out. If m_error contains an error message, it is written to out as well.

Parameters

out	Output stream to write log messages to.

if (m_command_exit_status != 0) out << "[" << m_hostname << "] exit status = " << m_command_exit_status << "\n";

Definition at line 700 of file SshSocketHandler.cc.

void SshSocketHandler::enable_debug ( )

static

Enables debug logging output.

Sets ms_debug_enabled to true to cause verbose logging messages to be displayed to stdout.

Definition at line 125 of file SshSocketHandler.cc.

void SshSocketHandler::global_request_callback	(	ssh_session	session,
		ssh_message	message
	)

libssh global request callback.

This function currenly just logs a message and returns.

Parameters

session	libssh session object
message	libssh message

Definition at line 551 of file SshSocketHandler.cc.

bool SshSocketHandler::handle	(	int	sd,
		int	events
	)

virtual

Socket event handler function.

Asynchronously handles ssh connection establishment and command execution. If an error is encountered during either connection establishment or command execution, then an error message is stored in m_error and m_cond is signalled. Upon completion of command execution, the exit status is stored in m_command_exit_status.

Parameters

sd	Socket descriptor
events	Bitmask of polling events

See also: PollEvent::Flags

Returns: true on success, false if an error was encountered.

been set, then we need to read again to get the exit status

Implements Hypertable::RawSocketHandler.

Definition at line 209 of file SshSocketHandler.cc.

const std::string Hypertable::SshSocketHandler::hostname ( ) const

inline

Returns hostname.

Returns: Hostname

Definition at line 198 of file SshSocketHandler.h.

bool SshSocketHandler::issue_command ( const std::string & command )

Asynchronously issues a command.

If an error is encountered while attempting to issue command and error message is stored in m_error and false is returned.

Parameters

command Command to issue

Returns: true if command was successfully issued, false otherwise.

Definition at line 574 of file SshSocketHandler.cc.

void SshSocketHandler::log_callback	(	ssh_session	session,
		int	priority,
		const char *	message
	)

Writes log messages to logging output collector.

If priority is greater than 1, this function writes message to the logging output buffer m_log_buffer. If m_log_buffer fills up, it gets added to m_log_collector and a new one is allocted.

Parameters

session	libssh session object
priority	Message priority
message	Log message

Definition at line 510 of file SshSocketHandler.cc.

virtual int Hypertable::SshSocketHandler::poll_interest ( int sd )

inlinevirtual

Returns current polling interest.

Returns: Current polling interest

Implements Hypertable::RawSocketHandler.

Definition at line 91 of file SshSocketHandler.h.

void SshSocketHandler::set_exit_status ( int exit_status )

libssh exit status callback This function sets m_command_exit_status to exit_status, sets m_command_exit_status_is_set to true, and then signals m_cond.

Parameters

exit_status Exit status of issued command

Definition at line 557 of file SshSocketHandler.cc.

void SshSocketHandler::set_libssh_verbosity ( const std::string & value )

static

Sets libssh logging verbosity level.

Parses value and sets ms_libssh_verbosity accordingly. The valid values for value are: none, warning, protocol, packet, functions. If value does not match (case insensitively) any of the value values, then an error message is written to the console and exit is called with status code 1.

Definition at line 127 of file SshSocketHandler.cc.

void SshSocketHandler::set_terminal_output ( bool val )

Tells handler to send collected output subsequent output to terminal If val is true, sends any collected stdout or stderr output to terminal and sets m_terminal_output to true which causes any subsequent output collected to be sent to the terminal.

Otherwise, m_terminal_output is set to false which prevents subsequent output from being sent to the terminal.

Parameters

val	If true, enable terminal output, otherwise disable it

Definition at line 648 of file SshSocketHandler.cc.

bool SshSocketHandler::socket_has_data ( )

private

Determines if data available on socket for reading Checks socket descriptor m_sd to see if there is any data available for reading.

Returns: true if data is available, false otherwise

Definition at line 833 of file SshSocketHandler.cc.

bool SshSocketHandler::verify_knownhost ( )

private

Verifies host with public key method.

Verifies host and writes known host file. m_error is populated with an error message on failure.

Returns: true on success, false on error.

Definition at line 718 of file SshSocketHandler.cc.

bool SshSocketHandler::wait_for_command_completion ( )

Waits for command completion.

This function blocks on m_cond until the command previously issued by issue_command() has completed or stopped due to an error or m_cancelled was set to true.

Returns: true if command successfully completed, false if m_error is contains an error message or m_command_exit_status was set to a non-zero value or m_cancelled is true and m_state is not STATE_CONNECTED.

Definition at line 623 of file SshSocketHandler.cc.

bool SshSocketHandler::wait_for_connection ( std::chrono::system_clock::time_point deadline )

Waits for connection establishment.

Blocks on m_cond until in connected state or m_error is non-empty or m_cancelled is true. If connection is not established by deadline then m_error is set to "timeout" and false is returned.

Parameters

deadline Maximum wait time

Returns: true upon successful connection, false if connection attempt failed (m_error is non-empty) or deadline was reached before connection could be established

Definition at line 563 of file SshSocketHandler.cc.

void SshSocketHandler::write_to_stderr	(	const char *	output,
		size_t	len
	)

private

Writes output to stderr Writes output to stderr, prefixing each line with '[' hostname ']'.

Parameters

output	Pointer to output data
len	Length of data pointed to by `output`

Definition at line 804 of file SshSocketHandler.cc.

void SshSocketHandler::write_to_stdout	(	const char *	output,
		size_t	len
	)

private

Writes output to stdout Writes output to stdout, prefixing each line with '[' hostname ']'.

Parameters

output	Pointer to output data
len	Length of data pointed to by `output`

Definition at line 775 of file SshSocketHandler.cc.

Member Data Documentation

ssh_callbacks_struct Hypertable::SshSocketHandler::m_callbacks

private

libssh callbacks

Definition at line 266 of file SshSocketHandler.h.

bool Hypertable::SshSocketHandler::m_cancelled {}

private

Flag indicating that outstanding operations should be cancelled.

Definition at line 290 of file SshSocketHandler.h.

ssh_channel Hypertable::SshSocketHandler::m_channel

private

libssh channel object

Definition at line 251 of file SshSocketHandler.h.

ssh_channel_callbacks_struct Hypertable::SshSocketHandler::m_channel_callbacks

private

libssh channel callbacks

Definition at line 269 of file SshSocketHandler.h.

bool Hypertable::SshSocketHandler::m_channel_is_eof {}

private

Flag indicating that current channel is EOF.

Definition at line 293 of file SshSocketHandler.h.

Comm* Hypertable::SshSocketHandler::m_comm

private

Pointer to comm layer.

Definition at line 239 of file SshSocketHandler.h.

CommAddress Hypertable::SshSocketHandler::m_comm_address

private

Address of connection.

Definition at line 248 of file SshSocketHandler.h.

std::string Hypertable::SshSocketHandler::m_command

private

Current command being issued.

Definition at line 272 of file SshSocketHandler.h.

int Hypertable::SshSocketHandler::m_command_exit_status {}

private

Command exit status.

Definition at line 275 of file SshSocketHandler.h.

bool Hypertable::SshSocketHandler::m_command_exit_status_is_set {}

private

Flag indicating that the exit status has been set.

Definition at line 278 of file SshSocketHandler.h.

std::condition_variable Hypertable::SshSocketHandler::m_cond

private

Condition variable signalling connection and command completion.

Definition at line 236 of file SshSocketHandler.h.

std::string Hypertable::SshSocketHandler::m_error

private

Error message

Definition at line 263 of file SshSocketHandler.h.

std::string Hypertable::SshSocketHandler::m_hostname

private

Name of host to connect to.

Definition at line 242 of file SshSocketHandler.h.

bool Hypertable::SshSocketHandler::m_line_prefix_needed_stderr {}

private

Line prefix needs to be emitted on next stderr output.

Definition at line 287 of file SshSocketHandler.h.

bool Hypertable::SshSocketHandler::m_line_prefix_needed_stdout {}

private

Line prefix needs to be emitted on next stdout output.

Definition at line 284 of file SshSocketHandler.h.

SshOutputCollector::Buffer Hypertable::SshSocketHandler::m_log_buffer {}

private

Current logging output buffer.

Definition at line 299 of file SshSocketHandler.h.

SshOutputCollector Hypertable::SshSocketHandler::m_log_collector

private

Output collector for logging.

Definition at line 296 of file SshSocketHandler.h.

std::mutex Hypertable::SshSocketHandler::m_mutex

private

Mutex for serialzing access to members

Definition at line 233 of file SshSocketHandler.h.

int Hypertable::SshSocketHandler::m_poll_interest {}

private

Current polling interest.

Definition at line 260 of file SshSocketHandler.h.

int Hypertable::SshSocketHandler::m_sd {}

private

Socket descriptor.

Definition at line 257 of file SshSocketHandler.h.

ssh_session Hypertable::SshSocketHandler::m_ssh_session

private

libssh sesison object

Definition at line 245 of file SshSocketHandler.h.

int Hypertable::SshSocketHandler::m_state {}

private

Current handler state.

Definition at line 254 of file SshSocketHandler.h.

SshOutputCollector::Buffer Hypertable::SshSocketHandler::m_stderr_buffer {}

private

Current stderr output buffer.

Definition at line 311 of file SshSocketHandler.h.

SshOutputCollector Hypertable::SshSocketHandler::m_stderr_collector

private

Output collector for stderr.

Definition at line 308 of file SshSocketHandler.h.

SshOutputCollector::Buffer Hypertable::SshSocketHandler::m_stdout_buffer {}

private

Current stdout output buffer.

Definition at line 305 of file SshSocketHandler.h.

SshOutputCollector Hypertable::SshSocketHandler::m_stdout_collector

private

Output collector for stdout.

Definition at line 302 of file SshSocketHandler.h.

bool Hypertable::SshSocketHandler::m_terminal_output {}

private

Redirect output to terminal.

Definition at line 281 of file SshSocketHandler.h.

bool SshSocketHandler::ms_debug_enabled {}

staticprivate

Flag for enabling debugging output.

Definition at line 227 of file SshSocketHandler.h.

int SshSocketHandler::ms_libssh_verbosity {SSH_LOG_PROTOCOL}

staticprivate

Libssh logging verbosity level.

Definition at line 230 of file SshSocketHandler.h.

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

/home/doug/src/hypertable/src/cc/Tools/ssh/SshSocketHandler.h
/home/doug/src/hypertable/src/cc/Tools/ssh/SshSocketHandler.cc

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Static Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation