From f2ae3fb7cfaab738b171af13b1405a7284849f1e Mon Sep 17 00:00:00 2001
From: Ryan Zoeller <ryan.zoeller@aliaro.com>
Date: Fri, 28 Aug 2026 10:55:38 -0600
Subject: [PATCH] Add SO_DONTROUTE support to {get,set}sockopt

---
 src/backend/libc/net/sockopt.rs      | 10 ++++++++++
 src/backend/linux_raw/c.rs           |  2 +-
 src/backend/linux_raw/net/sockopt.rs | 10 ++++++++++
 src/net/sockopt.rs                   | 22 ++++++++++++++++++++++
 tests/net/sockopt.rs                 |  5 +++++
 5 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/src/backend/libc/net/sockopt.rs b/src/backend/libc/net/sockopt.rs
index 0f2e67b99..5873d848c 100644
--- a/src/backend/libc/net/sockopt.rs
+++ b/src/backend/libc/net/sockopt.rs
@@ -462,6 +462,16 @@ pub(crate) fn socket_cookie(fd: BorrowedFd<'_>) -> io::Result<u64> {
     getsockopt(fd, c::SOL_SOCKET, c::SO_COOKIE)
 }
 
+#[inline]
+pub(crate) fn socket_dont_route(fd: BorrowedFd<'_>) -> io::Result<bool> {
+    getsockopt(fd, c::SOL_SOCKET, c::SO_DONTROUTE).map(to_bool)
+}
+
+#[inline]
+pub(crate) fn set_socket_dont_route(fd: BorrowedFd<'_>, value: bool) -> io::Result<()> {
+    setsockopt(fd, c::SOL_SOCKET, c::SO_DONTROUTE, from_bool(value))
+}
+
 #[cfg(target_os = "linux")]
 #[inline]
 pub(crate) fn socket_incoming_cpu(fd: BorrowedFd<'_>) -> io::Result<u32> {
diff --git a/src/backend/linux_raw/c.rs b/src/backend/linux_raw/c.rs
index 762cdd479..53e8e37bc 100644
--- a/src/backend/linux_raw/c.rs
+++ b/src/backend/linux_raw/c.rs
@@ -97,7 +97,7 @@ pub(crate) use linux_raw_sys::{
         MSG_EOR, MSG_ERRQUEUE, MSG_MORE, MSG_NOSIGNAL, MSG_OOB, MSG_PEEK, MSG_TRUNC, MSG_WAITALL,
         SCM_CREDENTIALS, SCM_RIGHTS, SHUT_RD, SHUT_RDWR, SHUT_WR, SOCK_DGRAM, SOCK_RAW, SOCK_RDM,
         SOCK_SEQPACKET, SOCK_STREAM, SOL_SOCKET, SOL_XDP, SO_ACCEPTCONN, SO_BROADCAST, SO_COOKIE,
-        SO_DOMAIN, SO_ERROR, SO_INCOMING_CPU, SO_KEEPALIVE, SO_LINGER, SO_OOBINLINE,
+        SO_DOMAIN, SO_DONTROUTE, SO_ERROR, SO_INCOMING_CPU, SO_KEEPALIVE, SO_LINGER, SO_OOBINLINE,
         SO_ORIGINAL_DST, SO_PASSCRED, SO_PROTOCOL, SO_RCVBUF, SO_RCVBUFFORCE, SO_RCVTIMEO_NEW,
         SO_RCVTIMEO_NEW as SO_RCVTIMEO, SO_RCVTIMEO_OLD, SO_REUSEADDR, SO_REUSEPORT, SO_SNDBUF,
         SO_SNDBUFFORCE, SO_SNDTIMEO_NEW, SO_SNDTIMEO_NEW as SO_SNDTIMEO, SO_SNDTIMEO_OLD, SO_TYPE,
diff --git a/src/backend/linux_raw/net/sockopt.rs b/src/backend/linux_raw/net/sockopt.rs
index 85c65b085..af366c240 100644
--- a/src/backend/linux_raw/net/sockopt.rs
+++ b/src/backend/linux_raw/net/sockopt.rs
@@ -428,6 +428,16 @@ pub(crate) fn socket_cookie(fd: BorrowedFd<'_>) -> io::Result<u64> {
     getsockopt(fd, c::SOL_SOCKET, c::SO_COOKIE)
 }
 
+#[inline]
+pub(crate) fn socket_dont_route(fd: BorrowedFd<'_>) -> io::Result<bool> {
+    getsockopt(fd, c::SOL_SOCKET, c::SO_DONTROUTE).map(to_bool)
+}
+
+#[inline]
+pub(crate) fn set_socket_dont_route(fd: BorrowedFd<'_>, value: bool) -> io::Result<()> {
+    setsockopt(fd, c::SOL_SOCKET, c::SO_DONTROUTE, from_bool(value))
+}
+
 #[inline]
 pub(crate) fn socket_incoming_cpu(fd: BorrowedFd<'_>) -> io::Result<u32> {
     getsockopt(fd, c::SOL_SOCKET, c::SO_INCOMING_CPU)
diff --git a/src/net/sockopt.rs b/src/net/sockopt.rs
index 9536e175d..1a04841f8 100644
--- a/src/net/sockopt.rs
+++ b/src/net/sockopt.rs
@@ -702,6 +702,28 @@ pub fn socket_cookie<Fd: AsFd>(fd: Fd) -> io::Result<u64> {
     backend::net::sockopt::socket_cookie(fd.as_fd())
 }
 
+/// `getsockopt(fd, SOL_SOCKET, SO_DONTROUTE)`
+///
+/// See the [module-level documentation] for more.
+///
+/// [module-level documentation]: self#references-for-get_socket_-and-set_socket_-functions
+#[inline]
+#[doc(alias = "SO_DONTROUTE")]
+pub fn socket_dont_route<Fd: AsFd>(fd: Fd) -> io::Result<bool> {
+    backend::net::sockopt::socket_dont_route(fd.as_fd())
+}
+
+/// `setsockopt(fd, SOL_SOCKET, SO_DONTROUTE, value)`
+///
+/// See the [module-level documentation] for more.
+///
+/// [module-level documentation]: self#references-for-get_socket_-and-set_socket_-functions
+#[inline]
+#[doc(alias = "SO_DONTROUTE")]
+pub fn set_socket_dont_route<Fd: AsFd>(fd: Fd, value: bool) -> io::Result<()> {
+    backend::net::sockopt::set_socket_dont_route(fd.as_fd(), value)
+}
+
 /// `getsockopt(fd, SOL_SOCKET, SO_INCOMING_CPU)`
 ///
 /// See the [module-level documentation] for more.
diff --git a/tests/net/sockopt.rs b/tests/net/sockopt.rs
index d139d9a5c..c47bad5ca 100644
--- a/tests/net/sockopt.rs
+++ b/tests/net/sockopt.rs
@@ -166,6 +166,11 @@ fn test_sockopts_socket(s: &OwnedFd) {
         );
     }
 
+    // Check the initial value of `SO_DONTROUTE`, set it, and check it.
+    assert_eq!(sockopt::socket_dont_route(s).unwrap(), false);
+    sockopt::set_socket_dont_route(s, true).unwrap();
+    assert_eq!(sockopt::socket_dont_route(s).unwrap(), true);
+
     // Check the initial value of `SO_INCOMING_CPU`, set it, and check it.
     #[cfg(target_os = "linux")]
     {