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// Portions of this file are Copyright 2014 The Rust Project Developers.
// See https://www.rust-lang.org/policies/licenses.
//! Operating system signals.
use crate::errno::Errno;
use crate::{Error, Result};
use cfg_if::cfg_if;
use std::fmt;
use std::mem;
#[cfg(any(target_os = "dragonfly", target_os = "freebsd"))]
use std::os::unix::io::RawFd;
use std::ptr;
use std::str::FromStr;
#[cfg(not(any(target_os = "openbsd", target_os = "redox")))]
#[cfg(any(feature = "aio", feature = "signal"))]
pub use self::sigevent::*;
#[cfg(any(feature = "aio", feature = "process", feature = "signal"))]
libc_enum! {
/// Types of operating system signals
// Currently there is only one definition of c_int in libc, as well as only one
// type for signal constants.
// We would prefer to use the libc::c_int alias in the repr attribute. Unfortunately
// this is not (yet) possible.
#[repr(i32)]
#[non_exhaustive]
#[cfg_attr(docsrs, doc(cfg(any(feature = "aio", feature = "signal"))))]
pub enum Signal {
/// Hangup
SIGHUP,
/// Interrupt
SIGINT,
/// Quit
SIGQUIT,
/// Illegal instruction (not reset when caught)
SIGILL,
/// Trace trap (not reset when caught)
SIGTRAP,
/// Abort
SIGABRT,
/// Bus error
SIGBUS,
/// Floating point exception
SIGFPE,
/// Kill (cannot be caught or ignored)
SIGKILL,
/// User defined signal 1
SIGUSR1,
/// Segmentation violation
SIGSEGV,
/// User defined signal 2
SIGUSR2,
/// Write on a pipe with no one to read it
SIGPIPE,
/// Alarm clock
SIGALRM,
/// Software termination signal from kill
SIGTERM,
/// Stack fault (obsolete)
#[cfg(all(any(target_os = "android", target_os = "emscripten",
target_os = "fuchsia", target_os = "linux"),
not(any(target_arch = "mips", target_arch = "mips64",
target_arch = "sparc64"))))]
SIGSTKFLT,
/// To parent on child stop or exit
SIGCHLD,
/// Continue a stopped process
SIGCONT,
/// Sendable stop signal not from tty
SIGSTOP,
/// Stop signal from tty
SIGTSTP,
/// To readers pgrp upon background tty read
SIGTTIN,
/// Like TTIN if (tp->t_local&LTOSTOP)
SIGTTOU,
/// Urgent condition on IO channel
SIGURG,
/// Exceeded CPU time limit
SIGXCPU,
/// Exceeded file size limit
SIGXFSZ,
/// Virtual time alarm
SIGVTALRM,
/// Profiling time alarm
SIGPROF,
/// Window size changes
SIGWINCH,
/// Input/output possible signal
#[cfg(not(target_os = "haiku"))]
#[cfg_attr(docsrs, doc(cfg(all())))]
SIGIO,
#[cfg(any(target_os = "android", target_os = "emscripten",
target_os = "fuchsia", target_os = "linux"))]
#[cfg_attr(docsrs, doc(cfg(all())))]
/// Power failure imminent.
SIGPWR,
/// Bad system call
SIGSYS,
#[cfg(not(any(target_os = "android", target_os = "emscripten",
target_os = "fuchsia", target_os = "linux",
target_os = "redox", target_os = "haiku")))]
#[cfg_attr(docsrs, doc(cfg(all())))]
/// Emulator trap
SIGEMT,
#[cfg(not(any(target_os = "android", target_os = "emscripten",
target_os = "fuchsia", target_os = "linux",
target_os = "redox", target_os = "haiku")))]
#[cfg_attr(docsrs, doc(cfg(all())))]
/// Information request
SIGINFO,
}
impl TryFrom<i32>
}
#[cfg(feature = "signal")]
impl FromStr for Signal {
type Err = Error;
fn from_str(s: &str) -> Result<Signal> {
Ok(match s {
"SIGHUP" => Signal::SIGHUP,
"SIGINT" => Signal::SIGINT,
"SIGQUIT" => Signal::SIGQUIT,
"SIGILL" => Signal::SIGILL,
"SIGTRAP" => Signal::SIGTRAP,
"SIGABRT" => Signal::SIGABRT,
"SIGBUS" => Signal::SIGBUS,
"SIGFPE" => Signal::SIGFPE,
"SIGKILL" => Signal::SIGKILL,
"SIGUSR1" => Signal::SIGUSR1,
"SIGSEGV" => Signal::SIGSEGV,
"SIGUSR2" => Signal::SIGUSR2,
"SIGPIPE" => Signal::SIGPIPE,
"SIGALRM" => Signal::SIGALRM,
"SIGTERM" => Signal::SIGTERM,
#[cfg(all(
any(
target_os = "android",
target_os = "emscripten",
target_os = "fuchsia",
target_os = "linux"
),
not(any(
target_arch = "mips",
target_arch = "mips64",
target_arch = "sparc64"
))
))]
"SIGSTKFLT" => Signal::SIGSTKFLT,
"SIGCHLD" => Signal::SIGCHLD,
"SIGCONT" => Signal::SIGCONT,
"SIGSTOP" => Signal::SIGSTOP,
"SIGTSTP" => Signal::SIGTSTP,
"SIGTTIN" => Signal::SIGTTIN,
"SIGTTOU" => Signal::SIGTTOU,
"SIGURG" => Signal::SIGURG,
"SIGXCPU" => Signal::SIGXCPU,
"SIGXFSZ" => Signal::SIGXFSZ,
"SIGVTALRM" => Signal::SIGVTALRM,
"SIGPROF" => Signal::SIGPROF,
"SIGWINCH" => Signal::SIGWINCH,
#[cfg(not(target_os = "haiku"))]
"SIGIO" => Signal::SIGIO,
#[cfg(any(
target_os = "android",
target_os = "emscripten",
target_os = "fuchsia",
target_os = "linux"
))]
"SIGPWR" => Signal::SIGPWR,
"SIGSYS" => Signal::SIGSYS,
#[cfg(not(any(
target_os = "android",
target_os = "emscripten",
target_os = "fuchsia",
target_os = "linux",
target_os = "redox",
target_os = "haiku"
)))]
"SIGEMT" => Signal::SIGEMT,
#[cfg(not(any(
target_os = "android",
target_os = "emscripten",
target_os = "fuchsia",
target_os = "linux",
target_os = "redox",
target_os = "haiku"
)))]
"SIGINFO" => Signal::SIGINFO,
_ => return Err(Errno::EINVAL),
})
}
}
#[cfg(feature = "signal")]
impl Signal {
/// Returns name of signal.
///
/// This function is equivalent to `<Signal as AsRef<str>>::as_ref()`,
/// with difference that returned string is `'static`
/// and not bound to `self`'s lifetime.
pub const fn as_str(self) -> &'static str {
match self {
Signal::SIGHUP => "SIGHUP",
Signal::SIGINT => "SIGINT",
Signal::SIGQUIT => "SIGQUIT",
Signal::SIGILL => "SIGILL",
Signal::SIGTRAP => "SIGTRAP",
Signal::SIGABRT => "SIGABRT",
Signal::SIGBUS => "SIGBUS",
Signal::SIGFPE => "SIGFPE",
Signal::SIGKILL => "SIGKILL",
Signal::SIGUSR1 => "SIGUSR1",
Signal::SIGSEGV => "SIGSEGV",
Signal::SIGUSR2 => "SIGUSR2",
Signal::SIGPIPE => "SIGPIPE",
Signal::SIGALRM => "SIGALRM",
Signal::SIGTERM => "SIGTERM",
#[cfg(all(
any(
target_os = "android",
target_os = "emscripten",
target_os = "fuchsia",
target_os = "linux"
),
not(any(
target_arch = "mips",
target_arch = "mips64",
target_arch = "sparc64"
))
))]
Signal::SIGSTKFLT => "SIGSTKFLT",
Signal::SIGCHLD => "SIGCHLD",
Signal::SIGCONT => "SIGCONT",
Signal::SIGSTOP => "SIGSTOP",
Signal::SIGTSTP => "SIGTSTP",
Signal::SIGTTIN => "SIGTTIN",
Signal::SIGTTOU => "SIGTTOU",
Signal::SIGURG => "SIGURG",
Signal::SIGXCPU => "SIGXCPU",
Signal::SIGXFSZ => "SIGXFSZ",
Signal::SIGVTALRM => "SIGVTALRM",
Signal::SIGPROF => "SIGPROF",
Signal::SIGWINCH => "SIGWINCH",
#[cfg(not(target_os = "haiku"))]
Signal::SIGIO => "SIGIO",
#[cfg(any(
target_os = "android",
target_os = "emscripten",
target_os = "fuchsia",
target_os = "linux"
))]
Signal::SIGPWR => "SIGPWR",
Signal::SIGSYS => "SIGSYS",
#[cfg(not(any(
target_os = "android",
target_os = "emscripten",
target_os = "fuchsia",
target_os = "linux",
target_os = "redox",
target_os = "haiku"
)))]
Signal::SIGEMT => "SIGEMT",
#[cfg(not(any(
target_os = "android",
target_os = "emscripten",
target_os = "fuchsia",
target_os = "linux",
target_os = "redox",
target_os = "haiku"
)))]
Signal::SIGINFO => "SIGINFO",
}
}
}
#[cfg(feature = "signal")]
impl AsRef<str> for Signal {
fn as_ref(&self) -> &str {
self.as_str()
}
}
#[cfg(feature = "signal")]
impl fmt::Display for Signal {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.write_str(self.as_ref())
}
}
#[cfg(feature = "signal")]
pub use self::Signal::*;
#[cfg(target_os = "redox")]
#[cfg(feature = "signal")]
const SIGNALS: [Signal; 29] = [
SIGHUP, SIGINT, SIGQUIT, SIGILL, SIGTRAP, SIGABRT, SIGBUS, SIGFPE, SIGKILL,
SIGUSR1, SIGSEGV, SIGUSR2, SIGPIPE, SIGALRM, SIGTERM, SIGCHLD, SIGCONT,
SIGSTOP, SIGTSTP, SIGTTIN, SIGTTOU, SIGURG, SIGXCPU, SIGXFSZ, SIGVTALRM,
SIGPROF, SIGWINCH, SIGIO, SIGSYS,
];
#[cfg(target_os = "haiku")]
#[cfg(feature = "signal")]
const SIGNALS: [Signal; 28] = [
SIGHUP, SIGINT, SIGQUIT, SIGILL, SIGTRAP, SIGABRT, SIGBUS, SIGFPE, SIGKILL,
SIGUSR1, SIGSEGV, SIGUSR2, SIGPIPE, SIGALRM, SIGTERM, SIGCHLD, SIGCONT,
SIGSTOP, SIGTSTP, SIGTTIN, SIGTTOU, SIGURG, SIGXCPU, SIGXFSZ, SIGVTALRM,
SIGPROF, SIGWINCH, SIGSYS,
];
#[cfg(all(
any(
target_os = "linux",
target_os = "android",
target_os = "emscripten",
target_os = "fuchsia"
),
not(any(
target_arch = "mips",
target_arch = "mips64",
target_arch = "sparc64"
))
))]
#[cfg(feature = "signal")]
const SIGNALS: [Signal; 31] = [
SIGHUP, SIGINT, SIGQUIT, SIGILL, SIGTRAP, SIGABRT, SIGBUS, SIGFPE, SIGKILL,
SIGUSR1, SIGSEGV, SIGUSR2, SIGPIPE, SIGALRM, SIGTERM, SIGSTKFLT, SIGCHLD,
SIGCONT, SIGSTOP, SIGTSTP, SIGTTIN, SIGTTOU, SIGURG, SIGXCPU, SIGXFSZ,
SIGVTALRM, SIGPROF, SIGWINCH, SIGIO, SIGPWR, SIGSYS,
];
#[cfg(all(
any(
target_os = "linux",
target_os = "android",
target_os = "emscripten",
target_os = "fuchsia"
),
any(target_arch = "mips", target_arch = "mips64", target_arch = "sparc64")
))]
#[cfg(feature = "signal")]
const SIGNALS: [Signal; 30] = [
SIGHUP, SIGINT, SIGQUIT, SIGILL, SIGTRAP, SIGABRT, SIGBUS, SIGFPE, SIGKILL,
SIGUSR1, SIGSEGV, SIGUSR2, SIGPIPE, SIGALRM, SIGTERM, SIGCHLD, SIGCONT,
SIGSTOP, SIGTSTP, SIGTTIN, SIGTTOU, SIGURG, SIGXCPU, SIGXFSZ, SIGVTALRM,
SIGPROF, SIGWINCH, SIGIO, SIGPWR, SIGSYS,
];
#[cfg(not(any(
target_os = "linux",
target_os = "android",
target_os = "fuchsia",
target_os = "emscripten",
target_os = "redox",
target_os = "haiku"
)))]
#[cfg(feature = "signal")]
const SIGNALS: [Signal; 31] = [
SIGHUP, SIGINT, SIGQUIT, SIGILL, SIGTRAP, SIGABRT, SIGBUS, SIGFPE, SIGKILL,
SIGUSR1, SIGSEGV, SIGUSR2, SIGPIPE, SIGALRM, SIGTERM, SIGCHLD, SIGCONT,
SIGSTOP, SIGTSTP, SIGTTIN, SIGTTOU, SIGURG, SIGXCPU, SIGXFSZ, SIGVTALRM,
SIGPROF, SIGWINCH, SIGIO, SIGSYS, SIGEMT, SIGINFO,
];
feature! {
#![feature = "signal"]
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
/// Iterate through all signals defined by this operating system
pub struct SignalIterator {
next: usize,
}
impl Iterator for SignalIterator {
type Item = Signal;
fn next(&mut self) -> Option<Signal> {
if self.next < SIGNALS.len() {
let next_signal = SIGNALS[self.next];
self.next += 1;
Some(next_signal)
} else {
None
}
}
}
impl Signal {
/// Iterate through all signals defined by this OS
pub const fn iterator() -> SignalIterator {
SignalIterator{next: 0}
}
}
/// Alias for [`SIGABRT`]
pub const SIGIOT : Signal = SIGABRT;
/// Alias for [`SIGIO`]
#[cfg(not(target_os = "haiku"))]
pub const SIGPOLL : Signal = SIGIO;
/// Alias for [`SIGSYS`]
pub const SIGUNUSED : Signal = SIGSYS;
cfg_if! {
if #[cfg(target_os = "redox")] {
type SaFlags_t = libc::c_ulong;
} else if #[cfg(target_env = "uclibc")] {
type SaFlags_t = libc::c_ulong;
} else {
type SaFlags_t = libc::c_int;
}
}
}
#[cfg(feature = "signal")]
libc_bitflags! {
/// Controls the behavior of a [`SigAction`]
#[cfg_attr(docsrs, doc(cfg(feature = "signal")))]
pub struct SaFlags: SaFlags_t {
/// When catching a [`Signal::SIGCHLD`] signal, the signal will be
/// generated only when a child process exits, not when a child process
/// stops.
SA_NOCLDSTOP;
/// When catching a [`Signal::SIGCHLD`] signal, the system will not
/// create zombie processes when children of the calling process exit.
SA_NOCLDWAIT;
/// Further occurrences of the delivered signal are not masked during
/// the execution of the handler.
SA_NODEFER;
/// The system will deliver the signal to the process on a signal stack,
/// specified by each thread with sigaltstack(2).
SA_ONSTACK;
/// The handler is reset back to the default at the moment the signal is
/// delivered.
SA_RESETHAND;
/// Requests that certain system calls restart if interrupted by this
/// signal. See the man page for complete details.
SA_RESTART;
/// This flag is controlled internally by Nix.
SA_SIGINFO;
}
}
#[cfg(feature = "signal")]
libc_enum! {
/// Specifies how certain functions should manipulate a signal mask
#[repr(i32)]
#[non_exhaustive]
#[cfg_attr(docsrs, doc(cfg(feature = "signal")))]
pub enum SigmaskHow {
/// The new mask is the union of the current mask and the specified set.
SIG_BLOCK,
/// The new mask is the intersection of the current mask and the
/// complement of the specified set.
SIG_UNBLOCK,
/// The current mask is replaced by the specified set.
SIG_SETMASK,
}
}
feature! {
#![feature = "signal"]
use crate::unistd::Pid;
use std::iter::Extend;
use std::iter::FromIterator;
use std::iter::IntoIterator;
/// Specifies a set of [`Signal`]s that may be blocked, waited for, etc.
// We are using `transparent` here to be super sure that `SigSet`
// is represented exactly like the `sigset_t` struct from C.
#[repr(transparent)]
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
pub struct SigSet {
sigset: libc::sigset_t
}
impl SigSet {
/// Initialize to include all signals.
#[doc(alias("sigfillset"))]
pub fn all() -> SigSet {
let mut sigset = mem::MaybeUninit::uninit();
let _ = unsafe { libc::sigfillset(sigset.as_mut_ptr()) };
unsafe{ SigSet { sigset: sigset.assume_init() } }
}
/// Initialize to include nothing.
#[doc(alias("sigemptyset"))]
pub fn empty() -> SigSet {
let mut sigset = mem::MaybeUninit::uninit();
let _ = unsafe { libc::sigemptyset(sigset.as_mut_ptr()) };
unsafe{ SigSet { sigset: sigset.assume_init() } }
}
/// Add the specified signal to the set.
#[doc(alias("sigaddset"))]
pub fn add(&mut self, signal: Signal) {
unsafe { libc::sigaddset(&mut self.sigset as *mut libc::sigset_t, signal as libc::c_int) };
}
/// Remove all signals from this set.
#[doc(alias("sigemptyset"))]
pub fn clear(&mut self) {
unsafe { libc::sigemptyset(&mut self.sigset as *mut libc::sigset_t) };
}
/// Remove the specified signal from this set.
#[doc(alias("sigdelset"))]
pub fn remove(&mut self, signal: Signal) {
unsafe { libc::sigdelset(&mut self.sigset as *mut libc::sigset_t, signal as libc::c_int) };
}
/// Return whether this set includes the specified signal.
#[doc(alias("sigismember"))]
pub fn contains(&self, signal: Signal) -> bool {
let res = unsafe { libc::sigismember(&self.sigset as *const libc::sigset_t, signal as libc::c_int) };
match res {
1 => true,
0 => false,
_ => unreachable!("unexpected value from sigismember"),
}
}
/// Returns an iterator that yields the signals contained in this set.
pub fn iter(&self) -> SigSetIter<'_> {
self.into_iter()
}
/// Gets the currently blocked (masked) set of signals for the calling thread.
pub fn thread_get_mask() -> Result<SigSet> {
let mut oldmask = mem::MaybeUninit::uninit();
do_pthread_sigmask(SigmaskHow::SIG_SETMASK, None, Some(oldmask.as_mut_ptr()))?;
Ok(unsafe{ SigSet{sigset: oldmask.assume_init()}})
}
/// Sets the set of signals as the signal mask for the calling thread.
pub fn thread_set_mask(&self) -> Result<()> {
pthread_sigmask(SigmaskHow::SIG_SETMASK, Some(self), None)
}
/// Adds the set of signals to the signal mask for the calling thread.
pub fn thread_block(&self) -> Result<()> {
pthread_sigmask(SigmaskHow::SIG_BLOCK, Some(self), None)
}
/// Removes the set of signals from the signal mask for the calling thread.
pub fn thread_unblock(&self) -> Result<()> {
pthread_sigmask(SigmaskHow::SIG_UNBLOCK, Some(self), None)
}
/// Sets the set of signals as the signal mask, and returns the old mask.
pub fn thread_swap_mask(&self, how: SigmaskHow) -> Result<SigSet> {
let mut oldmask = mem::MaybeUninit::uninit();
do_pthread_sigmask(how, Some(self), Some(oldmask.as_mut_ptr()))?;
Ok(unsafe{ SigSet{sigset: oldmask.assume_init()}})
}
/// Suspends execution of the calling thread until one of the signals in the
/// signal mask becomes pending, and returns the accepted signal.
#[cfg(not(target_os = "redox"))] // RedoxFS does not yet support sigwait
#[cfg_attr(docsrs, doc(cfg(all())))]
pub fn wait(&self) -> Result<Signal> {
use std::convert::TryFrom;
let mut signum = mem::MaybeUninit::uninit();
let res = unsafe { libc::sigwait(&self.sigset as *const libc::sigset_t, signum.as_mut_ptr()) };
Errno::result(res).map(|_| unsafe {
Signal::try_from(signum.assume_init()).unwrap()
})
}
/// Converts a `libc::sigset_t` object to a [`SigSet`] without checking whether the
/// `libc::sigset_t` is already initialized.
///
/// # Safety
///
/// The `sigset` passed in must be a valid an initialized `libc::sigset_t` by calling either
/// [`sigemptyset(3)`](https://man7.org/linux/man-pages/man3/sigemptyset.3p.html) or
/// [`sigfillset(3)`](https://man7.org/linux/man-pages/man3/sigfillset.3p.html).
/// Otherwise, the results are undefined.
pub unsafe fn from_sigset_t_unchecked(sigset: libc::sigset_t) -> SigSet {
SigSet { sigset }
}
}
impl AsRef<libc::sigset_t> for SigSet {
fn as_ref(&self) -> &libc::sigset_t {
&self.sigset
}
}
// TODO: Consider specialization for the case where T is &SigSet and libc::sigorset is available.
impl Extend<Signal> for SigSet {
fn extend<T>(&mut self, iter: T)
where T: IntoIterator<Item = Signal> {
for signal in iter {
self.add(signal);
}
}
}
impl FromIterator<Signal> for SigSet {
fn from_iter<T>(iter: T) -> Self
where T: IntoIterator<Item = Signal> {
let mut sigset = SigSet::empty();
sigset.extend(iter);
sigset
}
}
/// Iterator for a [`SigSet`].
///
/// Call [`SigSet::iter`] to create an iterator.
#[derive(Clone, Debug)]
pub struct SigSetIter<'a> {
sigset: &'a SigSet,
inner: SignalIterator,
}
impl Iterator for SigSetIter<'_> {
type Item = Signal;
fn next(&mut self) -> Option<Signal> {
loop {
match self.inner.next() {
None => return None,
Some(signal) if self.sigset.contains(signal) => return Some(signal),
Some(_signal) => continue,
}
}
}
}
impl<'a> IntoIterator for &'a SigSet {
type Item = Signal;
type IntoIter = SigSetIter<'a>;
fn into_iter(self) -> Self::IntoIter {
SigSetIter { sigset: self, inner: Signal::iterator() }
}
}
/// A signal handler.
#[allow(unknown_lints)]
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
pub enum SigHandler {
/// Default signal handling.
SigDfl,
/// Request that the signal be ignored.
SigIgn,
/// Use the given signal-catching function, which takes in the signal.
Handler(extern fn(libc::c_int)),
/// Use the given signal-catching function, which takes in the signal, information about how
/// the signal was generated, and a pointer to the threads `ucontext_t`.
#[cfg(not(target_os = "redox"))]
#[cfg_attr(docsrs, doc(cfg(all())))]
SigAction(extern fn(libc::c_int, *mut libc::siginfo_t, *mut libc::c_void))
}
/// Action to take on receipt of a signal. Corresponds to `sigaction`.
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
pub struct SigAction {
sigaction: libc::sigaction
}
impl SigAction {
/// Creates a new action.
///
/// The `SA_SIGINFO` bit in the `flags` argument is ignored (it will be set only if `handler`
/// is the `SigAction` variant). `mask` specifies other signals to block during execution of
/// the signal-catching function.
pub fn new(handler: SigHandler, flags: SaFlags, mask: SigSet) -> SigAction {
unsafe fn install_sig(p: *mut libc::sigaction, handler: SigHandler) {
(*p).sa_sigaction = match handler {
SigHandler::SigDfl => libc::SIG_DFL,
SigHandler::SigIgn => libc::SIG_IGN,
SigHandler::Handler(f) => f as *const extern fn(libc::c_int) as usize,
#[cfg(not(target_os = "redox"))]
SigHandler::SigAction(f) => f as *const extern fn(libc::c_int, *mut libc::siginfo_t, *mut libc::c_void) as usize,
};
}
let mut s = mem::MaybeUninit::<libc::sigaction>::uninit();
unsafe {
let p = s.as_mut_ptr();
install_sig(p, handler);
(*p).sa_flags = match handler {
#[cfg(not(target_os = "redox"))]
SigHandler::SigAction(_) => (flags | SaFlags::SA_SIGINFO).bits(),
_ => (flags - SaFlags::SA_SIGINFO).bits(),
};
(*p).sa_mask = mask.sigset;
SigAction { sigaction: s.assume_init() }
}
}
/// Returns the flags set on the action.
pub fn flags(&self) -> SaFlags {
SaFlags::from_bits_truncate(self.sigaction.sa_flags)
}
/// Returns the set of signals that are blocked during execution of the action's
/// signal-catching function.
pub fn mask(&self) -> SigSet {
SigSet { sigset: self.sigaction.sa_mask }
}
/// Returns the action's handler.
pub fn handler(&self) -> SigHandler {
match self.sigaction.sa_sigaction {
libc::SIG_DFL => SigHandler::SigDfl,
libc::SIG_IGN => SigHandler::SigIgn,
#[cfg(not(target_os = "redox"))]
p if self.flags().contains(SaFlags::SA_SIGINFO) =>
SigHandler::SigAction(
// Safe for one of two reasons:
// * The SigHandler was created by SigHandler::new, in which
// case the pointer is correct, or
// * The SigHandler was created by signal or sigaction, which
// are unsafe functions, so the caller should've somehow
// ensured that it is correctly initialized.
unsafe{
*(&p as *const usize
as *const extern fn(_, _, _))
}
as extern fn(_, _, _)),
p => SigHandler::Handler(
// Safe for one of two reasons:
// * The SigHandler was created by SigHandler::new, in which
// case the pointer is correct, or
// * The SigHandler was created by signal or sigaction, which
// are unsafe functions, so the caller should've somehow
// ensured that it is correctly initialized.
unsafe{
*(&p as *const usize
as *const extern fn(libc::c_int))
}
as extern fn(libc::c_int)),
}
}
}
/// Changes the action taken by a process on receipt of a specific signal.
///
/// `signal` can be any signal except `SIGKILL` or `SIGSTOP`. On success, it returns the previous
/// action for the given signal. If `sigaction` fails, no new signal handler is installed.
///
/// # Safety
///
/// * Signal handlers may be called at any point during execution, which limits
/// what is safe to do in the body of the signal-catching function. Be certain
/// to only make syscalls that are explicitly marked safe for signal handlers
/// and only share global data using atomics.
///
/// * There is also no guarantee that the old signal handler was installed
/// correctly. If it was installed by this crate, it will be. But if it was
/// installed by, for example, C code, then there is no guarantee its function
/// pointer is valid. In that case, this function effectively dereferences a
/// raw pointer of unknown provenance.
pub unsafe fn sigaction(signal: Signal, sigaction: &SigAction) -> Result<SigAction> {
let mut oldact = mem::MaybeUninit::<libc::sigaction>::uninit();
let res = libc::sigaction(signal as libc::c_int,
&sigaction.sigaction as *const libc::sigaction,
oldact.as_mut_ptr());
Errno::result(res).map(|_| SigAction { sigaction: oldact.assume_init() })
}
/// Signal management (see [signal(3p)](https://pubs.opengroup.org/onlinepubs/9699919799/functions/signal.html))
///
/// Installs `handler` for the given `signal`, returning the previous signal
/// handler. `signal` should only be used following another call to `signal` or
/// if the current handler is the default. The return value of `signal` is
/// undefined after setting the handler with [`sigaction`][SigActionFn].
///
/// # Safety
///
/// If the pointer to the previous signal handler is invalid, undefined
/// behavior could be invoked when casting it back to a [`SigAction`][SigActionStruct].
///
/// # Examples
///
/// Ignore `SIGINT`:
///
/// ```no_run
/// # use nix::sys::signal::{self, Signal, SigHandler};
/// unsafe { signal::signal(Signal::SIGINT, SigHandler::SigIgn) }.unwrap();
/// ```
///
/// Use a signal handler to set a flag variable:
///
/// ```no_run
/// # #[macro_use] extern crate lazy_static;
/// # use std::convert::TryFrom;
/// # use std::sync::atomic::{AtomicBool, Ordering};
/// # use nix::sys::signal::{self, Signal, SigHandler};
/// lazy_static! {
/// static ref SIGNALED: AtomicBool = AtomicBool::new(false);
/// }
///
/// extern fn handle_sigint(signal: libc::c_int) {
/// let signal = Signal::try_from(signal).unwrap();
/// SIGNALED.store(signal == Signal::SIGINT, Ordering::Relaxed);
/// }
///
/// fn main() {
/// let handler = SigHandler::Handler(handle_sigint);
/// unsafe { signal::signal(Signal::SIGINT, handler) }.unwrap();
/// }
/// ```
///
/// # Errors
///
/// Returns [`Error(Errno::EOPNOTSUPP)`] if `handler` is
/// [`SigAction`][SigActionStruct]. Use [`sigaction`][SigActionFn] instead.
///
/// `signal` also returns any error from `libc::signal`, such as when an attempt
/// is made to catch a signal that cannot be caught or to ignore a signal that
/// cannot be ignored.
///
/// [`Error::UnsupportedOperation`]: ../../enum.Error.html#variant.UnsupportedOperation
/// [SigActionStruct]: struct.SigAction.html
/// [sigactionFn]: fn.sigaction.html
pub unsafe fn signal(signal: Signal, handler: SigHandler) -> Result<SigHandler> {
let signal = signal as libc::c_int;
let res = match handler {
SigHandler::SigDfl => libc::signal(signal, libc::SIG_DFL),
SigHandler::SigIgn => libc::signal(signal, libc::SIG_IGN),
SigHandler::Handler(handler) => libc::signal(signal, handler as libc::sighandler_t),
#[cfg(not(target_os = "redox"))]
SigHandler::SigAction(_) => return Err(Errno::ENOTSUP),
};
Errno::result(res).map(|oldhandler| {
match oldhandler {
libc::SIG_DFL => SigHandler::SigDfl,
libc::SIG_IGN => SigHandler::SigIgn,
p => SigHandler::Handler(
*(&p as *const usize
as *const extern fn(libc::c_int))
as extern fn(libc::c_int)),
}
})
}
fn do_pthread_sigmask(how: SigmaskHow,
set: Option<&SigSet>,
oldset: Option<*mut libc::sigset_t>) -> Result<()> {
if set.is_none() && oldset.is_none() {
return Ok(())
}
let res = unsafe {
// if set or oldset is None, pass in null pointers instead
libc::pthread_sigmask(how as libc::c_int,
set.map_or_else(ptr::null::<libc::sigset_t>,
|s| &s.sigset as *const libc::sigset_t),
oldset.unwrap_or(ptr::null_mut())
)
};
Errno::result(res).map(drop)
}
/// Manages the signal mask (set of blocked signals) for the calling thread.
///
/// If the `set` parameter is `Some(..)`, then the signal mask will be updated with the signal set.
/// The `how` flag decides the type of update. If `set` is `None`, `how` will be ignored,
/// and no modification will take place.
///
/// If the 'oldset' parameter is `Some(..)` then the current signal mask will be written into it.
///
/// If both `set` and `oldset` is `Some(..)`, the current signal mask will be written into oldset,
/// and then it will be updated with `set`.
///
/// If both `set` and `oldset` is None, this function is a no-op.
///
/// For more information, visit the [`pthread_sigmask`](https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_sigmask.html),
/// or [`sigprocmask`](https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigprocmask.html) man pages.
pub fn pthread_sigmask(how: SigmaskHow,
set: Option<&SigSet>,
oldset: Option<&mut SigSet>) -> Result<()>
{
do_pthread_sigmask(how, set, oldset.map(|os| &mut os.sigset as *mut _ ))
}
/// Examine and change blocked signals.
///
/// For more information see the [`sigprocmask` man
/// pages](https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigprocmask.html).
pub fn sigprocmask(how: SigmaskHow, set: Option<&SigSet>, oldset: Option<&mut SigSet>) -> Result<()> {
if set.is_none() && oldset.is_none() {
return Ok(())
}
let res = unsafe {
// if set or oldset is None, pass in null pointers instead
libc::sigprocmask(how as libc::c_int,
set.map_or_else(ptr::null::<libc::sigset_t>,
|s| &s.sigset as *const libc::sigset_t),
oldset.map_or_else(ptr::null_mut::<libc::sigset_t>,
|os| &mut os.sigset as *mut libc::sigset_t))
};
Errno::result(res).map(drop)
}
/// Send a signal to a process
///
/// # Arguments
///
/// * `pid` - Specifies which processes should receive the signal.
/// - If positive, specifies an individual process.
/// - If zero, the signal will be sent to all processes whose group
/// ID is equal to the process group ID of the sender. This is a
#[cfg_attr(target_os = "fuchsia", doc = "variant of `killpg`.")]
#[cfg_attr(not(target_os = "fuchsia"), doc = "variant of [`killpg`].")]
/// - If `-1` and the process has super-user privileges, the signal
/// is sent to all processes exclusing system processes.
/// - If less than `-1`, the signal is sent to all processes whose
/// process group ID is equal to the absolute value of `pid`.
/// * `signal` - Signal to send. If `None`, error checking is performed
/// but no signal is actually sent.
///
/// See Also
/// [`kill(2)`](https://pubs.opengroup.org/onlinepubs/9699919799/functions/kill.html)
pub fn kill<T: Into<Option<Signal>>>(pid: Pid, signal: T) -> Result<()> {
let res = unsafe { libc::kill(pid.into(),
match signal.into() {
Some(s) => s as libc::c_int,
None => 0,
}) };
Errno::result(res).map(drop)
}
/// Send a signal to a process group
///
/// # Arguments
///
/// * `pgrp` - Process group to signal. If less then or equal 1, the behavior
/// is platform-specific.
/// * `signal` - Signal to send. If `None`, `killpg` will only preform error
/// checking and won't send any signal.
///
/// See Also [killpg(3)](https://pubs.opengroup.org/onlinepubs/9699919799/functions/killpg.html).
#[cfg(not(target_os = "fuchsia"))]
pub fn killpg<T: Into<Option<Signal>>>(pgrp: Pid, signal: T) -> Result<()> {
let res = unsafe { libc::killpg(pgrp.into(),
match signal.into() {
Some(s) => s as libc::c_int,
None => 0,
}) };
Errno::result(res).map(drop)
}
/// Send a signal to the current thread
///
/// See Also [raise(3)](https://pubs.opengroup.org/onlinepubs/9699919799/functions/raise.html)
pub fn raise(signal: Signal) -> Result<()> {
let res = unsafe { libc::raise(signal as libc::c_int) };
Errno::result(res).map(drop)
}
}
feature! {
#![any(feature = "aio", feature = "signal")]
/// Identifies a thread for [`SigevNotify::SigevThreadId`]
#[cfg(target_os = "freebsd")]
pub type type_of_thread_id = libc::lwpid_t;
/// Identifies a thread for [`SigevNotify::SigevThreadId`]
#[cfg(target_os = "linux")]
pub type type_of_thread_id = libc::pid_t;
/// Specifies the notification method used by a [`SigEvent`]
// sigval is actually a union of a int and a void*. But it's never really used
// as a pointer, because neither libc nor the kernel ever dereference it. nix
// therefore presents it as an intptr_t, which is how kevent uses it.
#[cfg(not(any(target_os = "openbsd", target_os = "redox")))]
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
pub enum SigevNotify {
/// No notification will be delivered
SigevNone,
/// Notify by delivering a signal to the process.
SigevSignal {
/// Signal to deliver
signal: Signal,
/// Will be present in the `si_value` field of the [`libc::siginfo_t`]
/// structure of the queued signal.
si_value: libc::intptr_t
},
// Note: SIGEV_THREAD is not implemented because libc::sigevent does not
// expose a way to set the union members needed by SIGEV_THREAD.
/// Notify by delivering an event to a kqueue.
#[cfg(any(target_os = "dragonfly", target_os = "freebsd"))]
#[cfg_attr(docsrs, doc(cfg(all())))]
SigevKevent {
/// File descriptor of the kqueue to notify.
kq: RawFd,
/// Will be contained in the kevent's `udata` field.
udata: libc::intptr_t
},
/// Notify by delivering a signal to a thread.
#[cfg(any(target_os = "freebsd", target_os = "linux"))]
#[cfg_attr(docsrs, doc(cfg(all())))]
SigevThreadId {
/// Signal to send
signal: Signal,
/// LWP ID of the thread to notify
thread_id: type_of_thread_id,
/// Will be present in the `si_value` field of the [`libc::siginfo_t`]
/// structure of the queued signal.
si_value: libc::intptr_t
},
}
}
#[cfg(not(any(target_os = "openbsd", target_os = "redox")))]
#[cfg_attr(docsrs, doc(cfg(all())))]
mod sigevent {
feature! {
#![any(feature = "aio", feature = "signal")]
use std::mem;
use std::ptr;
use super::SigevNotify;
#[cfg(any(target_os = "freebsd", target_os = "linux"))]
use super::type_of_thread_id;
/// Used to request asynchronous notification of the completion of certain
/// events, such as POSIX AIO and timers.
#[repr(C)]
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
pub struct SigEvent {
sigevent: libc::sigevent
}
impl SigEvent {
/// **Note:** this constructor does not allow the user to set the
/// `sigev_notify_kevent_flags` field. That's considered ok because on FreeBSD
/// at least those flags don't do anything useful. That field is part of a
/// union that shares space with the more genuinely useful fields.
///
/// **Note:** This constructor also doesn't allow the caller to set the
/// `sigev_notify_function` or `sigev_notify_attributes` fields, which are
/// required for `SIGEV_THREAD`. That's considered ok because on no operating
/// system is `SIGEV_THREAD` the most efficient way to deliver AIO
/// notification. FreeBSD and DragonFly BSD programs should prefer `SIGEV_KEVENT`.
/// Linux, Solaris, and portable programs should prefer `SIGEV_THREAD_ID` or
/// `SIGEV_SIGNAL`. That field is part of a union that shares space with the
/// more genuinely useful `sigev_notify_thread_id`
// Allow invalid_value warning on Fuchsia only.
// See https://github.com/nix-rust/nix/issues/1441
#[cfg_attr(target_os = "fuchsia", allow(invalid_value))]
pub fn new(sigev_notify: SigevNotify) -> SigEvent {
let mut sev = unsafe { mem::MaybeUninit::<libc::sigevent>::zeroed().assume_init() };
sev.sigev_notify = match sigev_notify {
SigevNotify::SigevNone => libc::SIGEV_NONE,
SigevNotify::SigevSignal{..} => libc::SIGEV_SIGNAL,
#[cfg(any(target_os = "dragonfly", target_os = "freebsd"))]
SigevNotify::SigevKevent{..} => libc::SIGEV_KEVENT,
#[cfg(target_os = "freebsd")]
SigevNotify::SigevThreadId{..} => libc::SIGEV_THREAD_ID,
#[cfg(all(target_os = "linux", target_env = "gnu", not(target_arch = "mips")))]
SigevNotify::SigevThreadId{..} => libc::SIGEV_THREAD_ID,
#[cfg(all(target_os = "linux", target_env = "uclibc"))]
SigevNotify::SigevThreadId{..} => libc::SIGEV_THREAD_ID,
#[cfg(any(all(target_os = "linux", target_env = "musl"), target_arch = "mips"))]
SigevNotify::SigevThreadId{..} => 4 // No SIGEV_THREAD_ID defined
};
sev.sigev_signo = match sigev_notify {
SigevNotify::SigevSignal{ signal, .. } => signal as libc::c_int,
#[cfg(any(target_os = "dragonfly", target_os = "freebsd"))]
SigevNotify::SigevKevent{ kq, ..} => kq,
#[cfg(any(target_os = "linux", target_os = "freebsd"))]
SigevNotify::SigevThreadId{ signal, .. } => signal as libc::c_int,
_ => 0
};
sev.sigev_value.sival_ptr = match sigev_notify {
SigevNotify::SigevNone => ptr::null_mut::<libc::c_void>(),
SigevNotify::SigevSignal{ si_value, .. } => si_value as *mut libc::c_void,
#[cfg(any(target_os = "dragonfly", target_os = "freebsd"))]
SigevNotify::SigevKevent{ udata, .. } => udata as *mut libc::c_void,
#[cfg(any(target_os = "freebsd", target_os = "linux"))]
SigevNotify::SigevThreadId{ si_value, .. } => si_value as *mut libc::c_void,
};
SigEvent::set_tid(&mut sev, &sigev_notify);
SigEvent{sigevent: sev}
}
#[cfg(any(target_os = "freebsd", target_os = "linux"))]
fn set_tid(sev: &mut libc::sigevent, sigev_notify: &SigevNotify) {
sev.sigev_notify_thread_id = match *sigev_notify {
SigevNotify::SigevThreadId { thread_id, .. } => thread_id,
_ => 0 as type_of_thread_id
};
}
#[cfg(not(any(target_os = "freebsd", target_os = "linux")))]
fn set_tid(_sev: &mut libc::sigevent, _sigev_notify: &SigevNotify) {
}
/// Return a copy of the inner structure
pub fn sigevent(&self) -> libc::sigevent {
self.sigevent
}
/// Returns a mutable pointer to the `sigevent` wrapped by `self`
pub fn as_mut_ptr(&mut self) -> *mut libc::sigevent {
&mut self.sigevent
}
}
impl<'a> From<&'a libc::sigevent> for SigEvent {
fn from(sigevent: &libc::sigevent) -> Self {
SigEvent{ sigevent: *sigevent }
}
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[cfg(not(target_os = "redox"))]
use std::thread;
#[test]
fn test_contains() {
let mut mask = SigSet::empty();
mask.add(SIGUSR1);
assert!(mask.contains(SIGUSR1));
assert!(!mask.contains(SIGUSR2));
let all = SigSet::all();
assert!(all.contains(SIGUSR1));
assert!(all.contains(SIGUSR2));
}
#[test]
fn test_clear() {
let mut set = SigSet::all();
set.clear();
for signal in Signal::iterator() {
assert!(!set.contains(signal));
}
}
#[test]
fn test_from_str_round_trips() {
for signal in Signal::iterator() {
assert_eq!(signal.as_ref().parse::<Signal>().unwrap(), signal);
assert_eq!(signal.to_string().parse::<Signal>().unwrap(), signal);
}
}
#[test]
fn test_from_str_invalid_value() {
let errval = Err(Errno::EINVAL);
assert_eq!("NOSIGNAL".parse::<Signal>(), errval);
assert_eq!("kill".parse::<Signal>(), errval);
assert_eq!("9".parse::<Signal>(), errval);
}
#[test]
fn test_extend() {
let mut one_signal = SigSet::empty();
one_signal.add(SIGUSR1);
let mut two_signals = SigSet::empty();
two_signals.add(SIGUSR2);
two_signals.extend(&one_signal);
assert!(two_signals.contains(SIGUSR1));
assert!(two_signals.contains(SIGUSR2));
}
#[test]
#[cfg(not(target_os = "redox"))]
fn test_thread_signal_set_mask() {
thread::spawn(|| {
let prev_mask = SigSet::thread_get_mask()
.expect("Failed to get existing signal mask!");
let mut test_mask = prev_mask;
test_mask.add(SIGUSR1);
test_mask.thread_set_mask().expect("assertion failed");
let new_mask =
SigSet::thread_get_mask().expect("Failed to get new mask!");
assert!(new_mask.contains(SIGUSR1));
assert!(!new_mask.contains(SIGUSR2));
prev_mask
.thread_set_mask()
.expect("Failed to revert signal mask!");
})
.join()
.unwrap();
}
#[test]
#[cfg(not(target_os = "redox"))]
fn test_thread_signal_block() {
thread::spawn(|| {
let mut mask = SigSet::empty();
mask.add(SIGUSR1);
mask.thread_block().expect("assertion failed");
assert!(SigSet::thread_get_mask().unwrap().contains(SIGUSR1));
})
.join()
.unwrap();
}
#[test]
#[cfg(not(target_os = "redox"))]
fn test_thread_signal_unblock() {
thread::spawn(|| {
let mut mask = SigSet::empty();
mask.add(SIGUSR1);
mask.thread_unblock().expect("assertion failed");
assert!(!SigSet::thread_get_mask().unwrap().contains(SIGUSR1));
})
.join()
.unwrap();
}
#[test]
#[cfg(not(target_os = "redox"))]
fn test_thread_signal_swap() {
thread::spawn(|| {
let mut mask = SigSet::empty();
mask.add(SIGUSR1);
mask.thread_block().unwrap();
assert!(SigSet::thread_get_mask().unwrap().contains(SIGUSR1));
let mut mask2 = SigSet::empty();
mask2.add(SIGUSR2);
let oldmask =
mask2.thread_swap_mask(SigmaskHow::SIG_SETMASK).unwrap();
assert!(oldmask.contains(SIGUSR1));
assert!(!oldmask.contains(SIGUSR2));
assert!(SigSet::thread_get_mask().unwrap().contains(SIGUSR2));
})
.join()
.unwrap();
}
#[test]
fn test_from_and_into_iterator() {
let sigset = SigSet::from_iter(vec![Signal::SIGUSR1, Signal::SIGUSR2]);
let signals = sigset.into_iter().collect::<Vec<Signal>>();
assert_eq!(signals, [Signal::SIGUSR1, Signal::SIGUSR2]);
}
#[test]
#[cfg(not(target_os = "redox"))]
fn test_sigaction() {
thread::spawn(|| {
extern "C" fn test_sigaction_handler(_: libc::c_int) {}
extern "C" fn test_sigaction_action(
_: libc::c_int,
_: *mut libc::siginfo_t,
_: *mut libc::c_void,
) {
}
let handler_sig = SigHandler::Handler(test_sigaction_handler);
let flags =
SaFlags::SA_ONSTACK | SaFlags::SA_RESTART | SaFlags::SA_SIGINFO;
let mut mask = SigSet::empty();
mask.add(SIGUSR1);
let action_sig = SigAction::new(handler_sig, flags, mask);
assert_eq!(
action_sig.flags(),
SaFlags::SA_ONSTACK | SaFlags::SA_RESTART
);
assert_eq!(action_sig.handler(), handler_sig);
mask = action_sig.mask();
assert!(mask.contains(SIGUSR1));
assert!(!mask.contains(SIGUSR2));
let handler_act = SigHandler::SigAction(test_sigaction_action);
let action_act = SigAction::new(handler_act, flags, mask);
assert_eq!(action_act.handler(), handler_act);
let action_dfl = SigAction::new(SigHandler::SigDfl, flags, mask);
assert_eq!(action_dfl.handler(), SigHandler::SigDfl);
let action_ign = SigAction::new(SigHandler::SigIgn, flags, mask);
assert_eq!(action_ign.handler(), SigHandler::SigIgn);
})
.join()
.unwrap();
}
#[test]
#[cfg(not(target_os = "redox"))]
fn test_sigwait() {
thread::spawn(|| {
let mut mask = SigSet::empty();
mask.add(SIGUSR1);
mask.add(SIGUSR2);
mask.thread_block().unwrap();
raise(SIGUSR1).unwrap();
assert_eq!(mask.wait().unwrap(), SIGUSR1);
})
.join()
.unwrap();
}
#[test]
fn test_from_sigset_t_unchecked() {
let src_set = SigSet::empty();
let set = unsafe { SigSet::from_sigset_t_unchecked(src_set.sigset) };
for signal in Signal::iterator() {
assert!(!set.contains(signal));
}
let src_set = SigSet::all();
let set = unsafe { SigSet::from_sigset_t_unchecked(src_set.sigset) };
for signal in Signal::iterator() {
assert!(set.contains(signal));
}
}
}