add get_socket_cookie helper

This cab be used for tracing to match the sockets in the kernel.

2 files changed, 22 insertions, 2 deletions

diff --git a/.bleep b/.bleep
index 3bb0bc2..2d45003 100644
--- a/.bleep
+++ b/.bleep
@@ -1 +1 @@
-c72b23651d92588806f386d2fa41bc408f453add
\ No newline at end of file
+f9ccfca0b81e38f866d5264559337e474e3fc4d4
\ No newline at end of file
diff --git a/pingora-core/src/protocols/l4/ext.rs b/pingora-core/src/protocols/l4/ext.rs
index aefd36c..90ad9ac 100644
--- a/pingora-core/src/protocols/l4/ext.rs
+++ b/pingora-core/src/protocols/l4/ext.rs
@@ -18,7 +18,7 @@
 
 use libc::socklen_t;
 #[cfg(target_os = "linux")]
-use libc::{c_int, c_void};
+use libc::{c_int, c_ulonglong, c_void};
 use pingora_error::{Error, ErrorType::*, OrErr, Result};
 use std::io::{self, ErrorKind};
 use std::mem;
@@ -281,6 +281,26 @@ pub fn set_tcp_fastopen_backlog(_fd: RawFd, _backlog: usize) -> Result<()> {
     Ok(())
 }
 
+#[cfg(target_os = "linux")]
+pub fn get_socket_cookie(fd: RawFd) -> io::Result<u64> {
+    let mut cookie: c_ulonglong = 0;
+    let mut size = std::mem::size_of_val(&cookie) as socklen_t;
+    get_opt(
+        fd,
+        libc::SOL_SOCKET,
+        libc::SO_COOKIE,
+        &mut cookie,
+        &mut size,
+    )?;
+
+    Ok(cookie as u64)
+}
+
+#[cfg(not(target_os = "linux"))]
+pub fn get_socket_cookie(_fd: RawFd) -> io::Result<u64> {
+    Ok(0) // SO_COOKIE is a Linux concept
+}
+
 /// connect() to the given address while optionally binding to the specific source address.
 ///
 /// The `set_socket` callback can be used to tune the socket before `connect()` is called.