SigInfo style data structure returned by SignalFD::readEvent(). More...

#include <SignalFD.hxx>

Public Types
using	Source = SigInfo::Source

using	ProcessCtx = SigInfo::ProcessCtx

using	UserSigData = SigInfo::UserSigData

using	QueueSigData = SigInfo::QueueSigData

using	MsgQueueData = SigInfo::MsgQueueData

using	TimerData = SigInfo::TimerData

using	ChildData = SigInfo::ChildData

using	SysData = SigInfo::SysData

using	PollData = SigInfo::PollData

Public Member Functions
	Info ()
	Creates a zero-initialized Info wrapper.

	Info (const no_init_t)
	Leaves the underlying data structure uninitialized.

const signalfd_siginfo *	raw () const

signalfd_siginfo *	raw ()

Signal	sigNr () const
	Returns the signal number that occurred.

Source	source () const
	Returns the source of the signal.

bool	isTrustedSource () const
	Returns whether the signal was sent from a trusted source (i.e. the kernel).

std::optional< const UserSigData >	userSigData () const
	Returns the Source::USER specific data.

std::optional< const QueueSigData >	queueSigData () const
	Returns the Source::QUEUE specific data.

std::optional< const MsgQueueData >	msgQueueData () const
	Returns the Source::MSGQ specific data.

std::optional< const TimerData >	timerData () const
	Returns the Source::TIMER specific data.

std::optional< const SysData >	sysData () const
	Returns signal::BAD_SYS specific data.

std::optional< const ChildData >	childData () const
	Returns signal::CHILD specific data.

std::optional< const PollData >	pollData () const
	Returns signal::POLL specific data.

void	clear ()
	Zeroes out the low level siginfo_t data structure.

Protected Member Functions
Errno	error () const
	Returns an error code that is generally unused on Linux (always 0).

ProcessCtx	procCtx () const

ProcessID	pid () const

UserID	uid () const

Protected Attributes
signalfd_siginfo	m_raw

Detailed Description

SigInfo style data structure returned by SignalFD::readEvent().

This is mostly the same as SigInfo, but tailored towards SignalFD. The underlying data structures differ too much to merge them into one on libcosmos level.

One difference between this structure and SigInfo is that SignalFDs cannot be used to catch fault signals (these can only be caught by SigAction signal handlers). Thus the fault signal part is missing from this structure.

Definition at line 116 of file SignalFD.hxx.

Member Typedef Documentation

◆ ChildData

using cosmos::SignalFD::Info::ChildData = SigInfo::ChildData

Definition at line 127 of file SignalFD.hxx.

◆ MsgQueueData

using cosmos::SignalFD::Info::MsgQueueData = SigInfo::MsgQueueData

Definition at line 125 of file SignalFD.hxx.

◆ PollData

using cosmos::SignalFD::Info::PollData = SigInfo::PollData

Definition at line 129 of file SignalFD.hxx.

◆ ProcessCtx

using cosmos::SignalFD::Info::ProcessCtx = SigInfo::ProcessCtx

Definition at line 122 of file SignalFD.hxx.

◆ QueueSigData

using cosmos::SignalFD::Info::QueueSigData = SigInfo::QueueSigData

Definition at line 124 of file SignalFD.hxx.

◆ Source

using cosmos::SignalFD::Info::Source = SigInfo::Source

Definition at line 121 of file SignalFD.hxx.

◆ SysData

using cosmos::SignalFD::Info::SysData = SigInfo::SysData

Definition at line 128 of file SignalFD.hxx.

◆ TimerData

using cosmos::SignalFD::Info::TimerData = SigInfo::TimerData

Definition at line 126 of file SignalFD.hxx.

◆ UserSigData

using cosmos::SignalFD::Info::UserSigData = SigInfo::UserSigData

Definition at line 123 of file SignalFD.hxx.

Constructor & Destructor Documentation

◆ Info() [1/2]

cosmos::SignalFD::Info::Info ( )

inline

Creates a zero-initialized Info wrapper.

Definition at line 134 of file SignalFD.hxx.

               {
                clear();
        }

◆ Info() [2/2]

cosmos::SignalFD::Info::Info ( const no_init_t )

inline

Leaves the underlying data structure uninitialized.

When Info is used as an output parameter only (the typical case) then you can invoke this constructor to avoid unnecessary zero-initialization.

Definition at line 144 of file SignalFD.hxx.

144{}

Member Function Documentation

◆ childData()

std::optional< const Info::ChildData > cosmos::Info::childData ( ) const

Returns signal::CHILD specific data.

This data is only available for sigNr() == signal::CHILD.

Definition at line 142 of file SignalFD.cxx.

                                                       {
        if (sigNr() == signal::CHILD) {
                using Event = ChildData::Event;
                const auto event = Event{m_raw.ssi_code};
 
                return ChildData{
                        event,
                        this->procCtx(),
                        event == Event::EXITED ? std::make_optional(ExitStatus{m_raw.ssi_status}) : std::nullopt,
                        event == Event::EXITED ? std::nullopt : std::make_optional(Signal{SignalNr{m_raw.ssi_status}}),
                        // is an uint64_t here, so cast it to clock_t for reuse
                        std::make_optional(ClockTicks{static_cast<clock_t>(m_raw.ssi_utime)}),
                        std::make_optional(ClockTicks{static_cast<clock_t>(m_raw.ssi_stime)})
                };
        }
 
        return std::nullopt;
}

◆ clear()

void cosmos::SignalFD::Info::clear ( )

inline

Zeroes out the low level siginfo_t data structure.

Definition at line 205 of file SignalFD.hxx.

                     {
                zero_object(m_raw);
        }

◆ error()

Errno cosmos::SignalFD::Info::error ( ) const

inlineprotected

Returns an error code that is generally unused on Linux (always 0).

An exception is the case of SIGSYS generated by seccomp(2) filters.

Definition at line 215 of file SignalFD.hxx.

                            {
                return Errno{m_raw.ssi_errno};
        }

◆ isTrustedSource()

bool cosmos::SignalFD::Info::isTrustedSource ( ) const

inline

Returns whether the signal was sent from a trusted source (i.e. the kernel).

See also: SigInfo::isTrustedSource().

Definition at line 170 of file SignalFD.hxx.

                                     {
                return m_raw.ssi_code >= 0;
        }

◆ msgQueueData()

std::optional< const Info::MsgQueueData > cosmos::Info::msgQueueData ( ) const

Returns the Source::MSGQ specific data.

Definition at line 104 of file SignalFD.cxx.

                                                             {
        if (source() == SigInfo::Source::MESGQ) {
                union sigval val;
                val.sival_ptr = reinterpret_cast<void*>(m_raw.ssi_ptr);
                return MsgQueueData{this->procCtx(), SigInfo::CustomData{val}};
        }
 
        return std::nullopt;
}

◆ pid()

ProcessID cosmos::SignalFD::Info::pid ( ) const

inlineprotected

Definition at line 223 of file SignalFD.hxx.

                              {
                // ssi_pid is unsigned while pid_t is signed
                return ProcessID{static_cast<pid_t>(m_raw.ssi_pid)};
        }

◆ pollData()

std::optional< const Info::PollData > cosmos::Info::pollData ( ) const

Returns signal::POLL specific data.

This data is only available for sigNr() == signal::POLL.

Definition at line 161 of file SignalFD.cxx.

                                                     {
        // SIGIO and SIGPOLL are the same on Linux, but just to be sure ...
        if (sigNr() == signal::IO_EVENT || sigNr() == signal::POLL) {
                return PollData{
                        PollData::Reason{m_raw.ssi_code},
                        FileNum{m_raw.ssi_fd},
                        /* there are conflicting types, PollEvents is short
                         * but in sigaction it's a long */
                        PollEvents{static_cast<short>(m_raw.ssi_band)}
                };
        }
 
        return std::nullopt;
}

◆ procCtx()

ProcessCtx cosmos::SignalFD::Info::procCtx ( ) const

inlineprotected

Definition at line 219 of file SignalFD.hxx.

                                   {
                return ProcessCtx{pid(), uid()};
        }

◆ queueSigData()

std::optional< const Info::QueueSigData > cosmos::Info::queueSigData ( ) const

Returns the Source::QUEUE specific data.

Definition at line 89 of file SignalFD.cxx.

                                                             {
        if (source() == SigInfo::Source::QUEUE) {
                // the signalfd_siginfo does not involve a union, but contains
                // always both the 32-bit int value and the 64-bit pointer
                // value. The pointer always contains the lower 32-bit of the
                // int, if an int was sent. Thus we place the pointer into the
                // union and constructor SigInfo::CustomData from it.
                union sigval val;
                val.sival_ptr = reinterpret_cast<void*>(m_raw.ssi_ptr);
                return QueueSigData{this->procCtx(), SigInfo::CustomData{val}};
        }
 
        return std::nullopt;
}

◆ raw() [1/2]

signalfd_siginfo * cosmos::SignalFD::Info::raw ( )

inline

Definition at line 150 of file SignalFD.hxx.

                                {
                return &m_raw;
        }

◆ raw() [2/2]

const signalfd_siginfo * cosmos::SignalFD::Info::raw ( ) const

inline

Definition at line 146 of file SignalFD.hxx.

                                            {
                return &m_raw;
        }

◆ sigNr()

Signal cosmos::SignalFD::Info::sigNr ( ) const

inline

Returns the signal number that occurred.

Definition at line 155 of file SignalFD.hxx.

                             {
                // ssi_signo is unsigned, while in sigaction it's signed.
                return Signal{SignalNr{static_cast<int>(m_raw.ssi_signo)}};
        }

◆ source()

Info::Source cosmos::Info::source ( ) const

Returns the source of the signal.

See also: SigInfo::source().

Definition at line 65 of file SignalFD.cxx.

                              {
        const std::initializer_list<Signal> SPECIAL_SIGS{
                signal::FPE, signal::BUS, signal::ILL, signal::SEGV,
                signal::BUS, signal::TRAP, signal::CHILD, signal::POLL,
                signal::BAD_SYS};
 
        // the lower level system call `rt_sigqueueinfo` allows userspace to
        // send arbitrary codes < 0, thus the signal number alone doesn't mean
        // the kernel was the source.
        if (isTrustedSource() && in_list(this->sigNr(), SPECIAL_SIGS)) {
                return Source::KERNEL;
        }
 
        return Source{m_raw.ssi_code};
}

◆ sysData()

std::optional< const Info::SysData > cosmos::Info::sysData ( ) const

Returns signal::BAD_SYS specific data.

This data is only available for sigNr() == signal::BAD_SYS.

Definition at line 127 of file SignalFD.cxx.

                                                   {
        if (sigNr() == signal::BAD_SYS) {
                return SysData{
                        SysData::Reason{m_raw.ssi_code},
                        // is an uint64_t here, so cast it to void*
                        reinterpret_cast<void*>(m_raw.ssi_call_addr),
                        m_raw.ssi_syscall,
                        ptrace::Arch{m_raw.ssi_arch},
                        this->error()
                };
        }
 
        return std::nullopt;
}

◆ timerData()

std::optional< const Info::TimerData > cosmos::Info::timerData ( ) const

Returns the Source::TIMER specific data.

Definition at line 114 of file SignalFD.cxx.

                                                       {
        if (source() == SigInfo::Source::TIMER) {
                return TimerData{
                        // is unsigned here, so cast it to signed
                        TimerData::TimerID{static_cast<int>(m_raw.ssi_tid)},
                        // same here
                        static_cast<int>(m_raw.ssi_overrun)
                };
        }
 
        return std::nullopt;
}

◆ uid()

UserID cosmos::SignalFD::Info::uid ( ) const

inlineprotected

Definition at line 228 of file SignalFD.hxx.

                           {
                return UserID{m_raw.ssi_uid};
        }

◆ userSigData()

std::optional< const Info::UserSigData > cosmos::Info::userSigData ( ) const

Returns the Source::USER specific data.

Definition at line 81 of file SignalFD.cxx.

                                                           {
        if (source() == SigInfo::Source::USER) {
                return UserSigData{this->procCtx()};
        }
 
        return std::nullopt;
}

Member Data Documentation

◆ m_raw

signalfd_siginfo cosmos::SignalFD::Info::m_raw

protected

Definition at line 234 of file SignalFD.hxx.

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

include/proc/SignalFD.hxx
src/proc/SignalFD.cxx

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Typedef Documentation

◆ ChildData

◆ MsgQueueData

◆ PollData

◆ ProcessCtx

◆ QueueSigData

◆ Source

◆ SysData

◆ TimerData

◆ UserSigData

Constructor & Destructor Documentation

◆ Info() [1/2]

◆ Info() [2/2]

Member Function Documentation

◆ childData()

◆ clear()

◆ error()

◆ isTrustedSource()

◆ msgQueueData()

◆ pid()

◆ pollData()

◆ procCtx()

◆ queueSigData()

◆ raw() [1/2]

◆ raw() [2/2]

◆ sigNr()

◆ source()

◆ sysData()

◆ timerData()

◆ uid()

◆ userSigData()

Member Data Documentation

◆ m_raw