Allow using abstract namespace for crashtracker unix socket

crashtracker/src/collector/crash_handler.rs

@@ -346,6 +346,15 @@ fn handle_posix_signal_impl(signum: i32) -> anyhow::Result<()> {
  res
  }
  ReceiverType::UnixSocket(path) => {
+ #[cfg(target_os = "linux")]
+ let mut unix_stream = if path.starts_with(['.', '/']) {
+ UnixStream::connect(path)
+ } else {
+ use std::os::linux::net::SocketAddrExt;
+ let addr = std::os::unix::net::SocketAddr::from_abstract_name(path)?;
+ UnixStream::connect_addr(&addr)
+ }?;
+ #[cfg(not(target_os = "linux"))]
  let mut unix_stream = UnixStream::connect(path)?;
  let res = emit_crashreport(
  &mut unix_stream,

crashtracker/src/crash_info/mod.rs

@@ -239,8 +239,11 @@ impl CrashInfo {
 impl CrashInfo {
  /// Emit the CrashInfo as structured json in file `path`.
  pub fn to_file(&self, path: &Path) -> anyhow::Result<()> {
- let file =
- File::create(path).with_context(|| format!("Failed to create {}", path.display()))?;
+ let file = File::options()
+ .create(true)
+ .append(true)
+ .open(path)
+ .with_context(|| format!("Failed to create {}", path.display()))?;
  serde_json::to_writer_pretty(file, self)
  .with_context(|| format!("Failed to write json to {}", path.display()))?;
  Ok(())

crashtracker/src/receiver.rs

@@ -24,15 +24,30 @@ pub fn resolve_frames(
 }
 
 pub fn get_unix_socket(socket_path: impl AsRef<str>) -> anyhow::Result<UnixListener> {
- let socket_path = socket_path.as_ref();
- if std::fs::metadata(socket_path).is_ok() {
- std::fs::remove_file(socket_path)
- .with_context(|| format!("could not delete previous socket at {:?}", socket_path))?;
+ fn path_bind(socket_path: impl AsRef<str>) -> anyhow::Result<UnixListener> {
+ let socket_path = socket_path.as_ref();
+ if std::fs::metadata(socket_path).is_ok() {
+ std::fs::remove_file(socket_path).with_context(|| {
+ format!("could not delete previous socket at {:?}", socket_path)
+ })?;
+ }
+ Ok(UnixListener::bind(socket_path)?)
  }
 
- let unix_listener =
- UnixListener::bind(socket_path).context("Could not create the unix socket")?;
- Ok(unix_listener)
+ #[cfg(target_os = "linux")]
+ let unix_listener = if socket_path.as_ref().starts_with(['.', '/']) {
+ path_bind(socket_path)
+ } else {
+ use std::os::linux::net::SocketAddrExt;
+ std::os::unix::net::SocketAddr::from_abstract_name(socket_path.as_ref())
+ .and_then(|addr| {
+ std::os::unix::net::UnixListener::bind_addr(&addr).and_then(UnixListener::from_std)
+ })
+ .map_err(anyhow::Error::msg)
+ };
+ #[cfg(not(target_os = "linux"))]
+ let unix_listener = path_bind(socket_path);
+ unix_listener.context("Could not create the unix socket")
 }
 
 pub fn receiver_entry_point_unix_socket(socket_path: impl AsRef<str>) -> anyhow::Result<()> {

sidecar/src/crashtracker.rs

@@ -1,13 +1,18 @@
 // Copyright 2021-Present Datadog, Inc. https://www.datadoghq.com/
 // SPDX-License-Identifier: Apache-2.0
 
-use std::{env, path::PathBuf};
+use std::path::PathBuf;
 
 use crate::primary_sidecar_identifier;
 
 pub fn crashtracker_unix_socket_path() -> PathBuf {
- env::temp_dir().join(format!(
+ let base_path = format!(
  concat!("libdatadog.ct.", crate::sidecar_version!(), "@{}.sock"),
  primary_sidecar_identifier()
- ))
+ );
+ #[cfg(target_os = "linux")]
+ let ret = base_path.into();
+ #[cfg(not(target_os = "linux"))]
+ let ret = std::env::temp_dir().join(base_path);
+ ret
 }

sidecar/src/setup/unix.rs

@@ -119,6 +119,10 @@ impl Default for SharedDirLiaison {
 }
 
 #[cfg(target_os = "linux")]
+// Important note:
+// Never put any runtime data which both the sidecar and the client processes must see onto disk.
+// In particular, when using different mount namespaces, but a shared network namespace, the
+// processes don't necessarily see the same things.
 mod linux {
  use std::{io, os::unix::net::UnixListener, path::PathBuf};