Restore default (ignore) Rust SIGPIPE behavior

Remove `reset_sigpipe` and other code that handles `SIGPIPE` in any way, such as ignoring it or forwarding it to the child process. This restores the default behaviour of the Rust standard library, which is to always ignore the signal. This behaviour will be inherited by the child process. See #12 for context.
appsignal · Nov 7, 2024 · f6beddb · f6beddb
1 parent 43fab5f
commit f6beddb
Show file tree

Hide file tree

Showing 2 changed files with 2 additions and 23 deletions.
diff --git a/src/main.rs b/src/main.rs
@@ -14,7 +14,7 @@ use crate::cli::Cli;
 use crate::client::client;
 use crate::log::{LogConfig, LogMessage, LogSeverity};
 use crate::package::NAME;
-use crate::signals::{has_terminating_intent, reset_sigpipe, signal_stream};
+use crate::signals::{has_terminating_intent, signal_stream};
 use crate::timestamp::SystemTimestamp;
 
 use ::log::{debug, error, trace};
@@ -38,8 +38,6 @@ use clap::Parser;
 use env_logger::Env;
 
 fn main() {
-    reset_sigpipe();
-
     env_logger::Builder::from_env(Env::default().default_filter_or("info"))
         .format(|buf, record| {
             let level = record.level().to_string().to_ascii_lowercase();

diff --git a/src/signals.rs b/src/signals.rs
@@ -9,7 +9,6 @@ fn nix_to_tokio(signal: &Signal) -> SignalKind {
         Signal::SIGTERM => SignalKind::terminate(),
         Signal::SIGHUP => SignalKind::hangup(),
         Signal::SIGQUIT => SignalKind::quit(),
-        Signal::SIGPIPE => SignalKind::pipe(),
         Signal::SIGUSR1 => SignalKind::user_defined1(),
         Signal::SIGUSR2 => SignalKind::user_defined2(),
         Signal::SIGWINCH => SignalKind::window_change(),
@@ -25,15 +24,14 @@ fn nix_to_tokio(signal: &Signal) -> SignalKind {
 // This list only includes signals that can be caught and handled by the
 // application. Signals that cannot be caught, such as SIGKILL and SIGSTOP,
 // are not included.
-const CHILD_FORWARDABLE_SIGNALS: [Signal; 8] = [
+const CHILD_FORWARDABLE_SIGNALS: [Signal; 7] = [
     Signal::SIGUSR1,
     Signal::SIGUSR2,
     Signal::SIGWINCH,
     Signal::SIGINT,
     Signal::SIGTERM,
     Signal::SIGHUP,
     Signal::SIGQUIT,
-    Signal::SIGPIPE,
 ];
 
 // Returns whether a signal returned by a `signal_stream` represents an intent
@@ -50,7 +48,6 @@ const CHILD_FORWARDABLE_SIGNALS: [Signal; 8] = [
 // - `SIGWINCH`, which notifies the process of a terminal resize (and whose default
 //   behaviour is to be ignored)
 // - `SIGHUP`, which is sometimes used to trigger configuration refreshes
-// - `SIGPIPE`, which notifies the process of a broken pipe
 //
 // The objective is to ensure that only signals which were sent with the explicit
 // intent to terminate the child process cause this process to terminate.
@@ -70,19 +67,3 @@ pub fn signal_stream() -> io::Result<impl Stream<Item = Signal>> {
 
     Ok(signals.map(|(signal, _)| signal))
 }
-
-// This function resets the SIGPIPE signal to its default behavior.
-// It is called at the beginning of the program.
-//
-// Signal handlers are inherited by child processes, and most software
-// expects SIGPIPE to be set to its default behavior. However,
-// the Rust standard library sets SIGPIPE to be ignored by default, which
-// can cause the child processes to behave differently than expected.
-//
-// See https://github.com/kurtbuilds/sigpipe (and the discussions linked
-// in the README) for more information.
-pub fn reset_sigpipe() {
-    unsafe {
-        libc::signal(libc::SIGPIPE, libc::SIG_DFL);
-    }
-}