From b8094f32703fe9a12585d6b122235b63110e7386 Mon Sep 17 00:00:00 2001
From: Maxim Ivanov <hi+github@yamlcoder.me>
Date: Sun, 5 Feb 2023 16:06:45 +0000
Subject: [PATCH] Make msghdr.msg_name optional

sendmsg can be used on connected sockets without
msg_name.
---
 src/io/send_to.rs    | 22 ++++++++++++++++------
 src/io/sendmsg_zc.rs | 20 ++++++++++++++++----
 2 files changed, 32 insertions(+), 10 deletions(-)

diff --git a/src/io/send_to.rs b/src/io/send_to.rs
index d9a61762..57049fc6 100644
--- a/src/io/send_to.rs
+++ b/src/io/send_to.rs
@@ -14,7 +14,7 @@ pub(crate) struct SendTo<T> {
     #[allow(dead_code)]
     io_slices: Vec<IoSlice<'static>>,
     #[allow(dead_code)]
-    socket_addr: Box<SockAddr>,
+    socket_addr: Option<Box<SockAddr>>,
     pub(crate) msghdr: Box<libc::msghdr>,
 }
 
@@ -22,7 +22,7 @@ impl<T: BoundedBuf> Op<SendTo<T>> {
     pub(crate) fn send_to(
         fd: &SharedFd,
         buf: T,
-        socket_addr: SocketAddr,
+        socket_addr: Option<SocketAddr>,
     ) -> io::Result<Op<SendTo<T>>> {
         use io_uring::{opcode, types};
 
@@ -30,13 +30,23 @@ impl<T: BoundedBuf> Op<SendTo<T>> {
             std::slice::from_raw_parts(buf.stable_ptr(), buf.bytes_init())
         })];
 
-        let socket_addr = Box::new(SockAddr::from(socket_addr));
-
         let mut msghdr: Box<libc::msghdr> = Box::new(unsafe { std::mem::zeroed() });
         msghdr.msg_iov = io_slices.as_ptr() as *mut _;
         msghdr.msg_iovlen = io_slices.len() as _;
-        msghdr.msg_name = socket_addr.as_ptr() as *mut libc::c_void;
-        msghdr.msg_namelen = socket_addr.len();
+
+        let socket_addr = match socket_addr {
+            Some(ref _socket_addr) => {
+                let socket_addr = Some(Box::new(SockAddr::from(_socket_addr)));
+                msghdr.msg_name = socket_addr.as_ptr() as *mut libc::c_void;
+                msghdr.msg_namelen = socket_addr.len();
+                socket_addr
+            }
+            None => {
+                msghdr.msg_name = std::ptr::null_mut();
+                msghdr.msg_namelen = 0;
+                None
+            }
+        };
 
         CONTEXT.with(|x| {
             x.handle().expect("Not in a runtime context").submit_op(
diff --git a/src/io/sendmsg_zc.rs b/src/io/sendmsg_zc.rs
index 2c266339..0863e483 100644
--- a/src/io/sendmsg_zc.rs
+++ b/src/io/sendmsg_zc.rs
@@ -13,7 +13,7 @@ pub(crate) struct SendMsgZc<T, U> {
     #[allow(dead_code)]
     io_bufs: Vec<T>,
     #[allow(dead_code)]
-    socket_addr: Box<SockAddr>,
+    socket_addr: Option<Box<SockAddr>>,
     msg_control: Option<U>,
     msghdr: libc::msghdr,
 
@@ -25,13 +25,11 @@ impl<T: BoundedBuf, U: BoundedBuf> Op<SendMsgZc<T, U>, MultiCQEFuture> {
     pub(crate) fn sendmsg_zc(
         fd: &SharedFd,
         io_bufs: Vec<T>,
-        socket_addr: SocketAddr,
+        socket_addr: Option<SocketAddr>,
         msg_control: Option<U>,
     ) -> io::Result<Self> {
         use io_uring::{opcode, types};
 
-        let socket_addr = Box::new(SockAddr::from(socket_addr));
-
         let mut msghdr: libc::msghdr = unsafe { std::mem::zeroed() };
 
         let mut io_slices: Vec<IoSlice> = Vec::with_capacity(io_bufs.len());
@@ -47,6 +45,20 @@ impl<T: BoundedBuf, U: BoundedBuf> Op<SendMsgZc<T, U>, MultiCQEFuture> {
         msghdr.msg_name = socket_addr.as_ptr() as *mut libc::c_void;
         msghdr.msg_namelen = socket_addr.len();
 
+        let socket_addr = match socket_addr {
+            Some(ref _socket_addr) => {
+                let socket_addr = Some(Box::new(SockAddr::from(_socket_addr)));
+                msghdr.msg_name = socket_addr.as_ptr() as *mut libc::c_void;
+                msghdr.msg_namelen = socket_addr.len();
+                socket_addr
+            }
+            None => {
+                msghdr.msg_name = std::ptr::null_mut();
+                msghdr.msg_namelen = 0;
+                None
+            }
+        };
+
         match msg_control {
             Some(ref _msg_control) => {
                 msghdr.msg_control = _msg_control.stable_ptr() as *mut _;