Pointer to pipefd[2] array in pipe() system calls. More...

#include <io.hxx>

Inheritance diagram for clues::item::PipeEnds:

Public Member Functions
std::string	str () const override
	Returns a human readable string representation of the item.

cosmos::FileNum	readEnd () const

cosmos::FileNum	writeEnd () const

bool	haveEnds () const
	Returns whether valid read and write end file numbers are stored.

Public Member Functions inherited from clues::item::PointerOutValue
	PointerOutValue (const std::string_view short_name, const std::string_view long_name={}, const ItemType type=ItemType::PARAM_OUT)

Public Member Functions inherited from clues::item::PointerValue
	PointerValue (const ItemType type, const std::string_view short_name, const std::string_view long_name)

Public Member Functions inherited from clues::SystemCallItem
	SystemCallItem (const ItemType type, const std::string_view short_name={}, const std::string_view long_name={})
	Constructs a new SystemCallItem.

auto	type () const

bool	isIn () const

bool	isOut () const

bool	isInOut () const

bool	isReturnValue () const

void	fill (const Tracee &proc, const Word word)
	Fills the item from the given register data.

bool	needsUpdate () const
	Returns whether the item needs to be updated after the system call is finished.

std::string_view	shortName () const
	Returns the friendly short name for this item.

std::string_view	longName () const
	Returns the friendly long name for this item, if available, else the short name.

auto	hasLongName () const

bool	isZero () const
	Returns whether the parameter is set to 0 / NULL.

Word	value () const
	Returns the currently stored raw value of the item.

template<typename OTHER>
OTHER	valueAs () const
	Helper to cast the strongly typed `Word` `m_val` to other strong enum types.

ForeignPtr	asPtr () const

Flags	flags () const

bool	deferFill () const

Protected Member Functions
void	reset ()

void	processValue (const Tracee &) override
	Processes the value stored in m_val acc. to the actual item type.

void	updateData (const Tracee &proc) override
	Called upon exit of the system call to update possible out parameters.

Protected Member Functions inherited from clues::SystemCallItem
void	setSystemCall (const SystemCall &sc)
	Sets the system call context this item is a part of.

Protected Attributes
cosmos::FileNum	m_read_end = cosmos::FileNum::INVALID

cosmos::FileNum	m_write_end = cosmos::FileNum::INVALID

Protected Attributes inherited from clues::SystemCallItem
const SystemCall *	m_call = nullptr
	The system call context this item part of.

const ItemType	m_type
	The type of item.

std::string_view	m_short_name
	A human readable short name for the item, should be one word only.

std::string_view	m_long_name
	A human readable longer name for the item.

Word	m_val
	The raw register value for the item.

Flags	m_flags
	Flags influencing the processing of the item.

Additional Inherited Members
Public Types inherited from clues::SystemCallItem
enum class	Flag { DEFER_FILL = 1 << 0 }

using	Flags = cosmos::BitMask<Flag>

Detailed Description

Pointer to pipefd[2] array in pipe() system calls.

Definition at line 21 of file io.hxx.

Constructor & Destructor Documentation

◆ PipeEnds()

clues::item::PipeEnds::PipeEnds ( )

inlineexplicit

Definition at line 25 of file io.hxx.

                            :
                        PointerOutValue{"pipefd", "pointer to array pipefd[2]"} {
        }

Member Function Documentation

◆ haveEnds()

bool clues::item::PipeEnds::haveEnds ( ) const

inline

Returns whether valid read and write end file numbers are stored.

On failed system calls or sudden Tracee death these can have invalid values.

Definition at line 44 of file io.hxx.

                              {
                return m_read_end != cosmos::FileNum::INVALID && m_write_end != cosmos::FileNum::INVALID;
        }

◆ processValue()

void clues::item::PipeEnds::processValue ( const Tracee & )

inlineoverrideprotectedvirtual

Processes the value stored in m_val acc. to the actual item type.

This function is called for all parameter types upon entry to a system call, and for ItemType::RETVAL upon exit from a system call.

For parameters of ItemType::PARAM_OUT this callback can be used to reset any stored data to be filled in later when updateData() is called.

Reimplemented from clues::SystemCallItem.

Definition at line 55 of file io.hxx.

                                                   {
                reset();
        }

◆ readEnd()

cosmos::FileNum clues::item::PipeEnds::readEnd ( ) const

inline

Definition at line 31 of file io.hxx.

                                      {
                return m_read_end;
        }

◆ reset()

void clues::item::PipeEnds::reset ( )

inlineprotected

Definition at line 50 of file io.hxx.

                     {
                m_read_end = cosmos::FileNum::INVALID;
                m_write_end = cosmos::FileNum::INVALID;
        }

◆ str()

std::string clues::item::PipeEnds::str ( ) const

overridevirtual

Returns a human readable string representation of the item.

This member function should be specialized in derived classes to output the item's data in a fashion suitable for the concrete item type.

Reimplemented from clues::SystemCallItem.

Definition at line 26 of file io.cxx.

                              {
        if (haveEnds()) {
                const auto ends_array = cosmos::sprintf("%d, %d",
                                cosmos::to_integral(m_read_end),
                                cosmos::to_integral(m_write_end));
                return clues::format::pointer(asPtr(), ends_array);
        } else {
                return clues::format::pointer(asPtr());
        }
}

◆ updateData()

void clues::item::PipeEnds::updateData ( const Tracee & t )

overrideprotectedvirtual

Called upon exit of the system call to update possible out parameters.

This function is called for parameters of ItemType::PARAM_OUT and ItemType::PARAM_IN_OUT upon system call exit to update the data from the values returned from the system call.

The default implementation calls processValue() to allow to share the same data processing code for input and output for item types that support both.

This function is called regardless of system call success or error, so it can happen that there is no valid data returned by the kernel or pointers in userspace are broken. Implementations should take this into consideration when operating on the data.

Reimplemented from clues::SystemCallItem.

Definition at line 13 of file io.cxx.

                                            {
        int ends[2];
 
        if (!proc.readStruct(asPtr(), ends)) {
                // probably bad userspace address or Tracee died
                reset();
                return;
        }
 
        m_read_end = cosmos::FileNum{ends[0]};
        m_write_end = cosmos::FileNum{ends[1]};
}

◆ writeEnd()

cosmos::FileNum clues::item::PipeEnds::writeEnd ( ) const

inline

Definition at line 35 of file io.hxx.

                                       {
                return m_write_end;
        }

Member Data Documentation

◆ m_read_end

cosmos::FileNum clues::item::PipeEnds::m_read_end = cosmos::FileNum::INVALID

protected

Definition at line 63 of file io.hxx.

◆ m_write_end

cosmos::FileNum clues::item::PipeEnds::m_write_end = cosmos::FileNum::INVALID

protected

Definition at line 64 of file io.hxx.

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

include/items/io.hxx
src/items/io.cxx

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ PipeEnds()

Member Function Documentation

◆ haveEnds()

◆ processValue()

◆ readEnd()

◆ reset()

◆ str()

◆ updateData()

◆ writeEnd()

Member Data Documentation

◆ m_read_end

◆ m_write_end