Add SocketAddress trait to reduce code duplicated across address types

src/backend/libc/net/addr.rs

@@ -12,6 +12,25 @@ use {
     core::slice,
 };
 
+use super::write_sockaddr::{encode_sockaddr_v4, encode_sockaddr_v6};
+use crate::net::{SocketAddrV4, SocketAddrV6, SocketAddress};
+
+unsafe impl SocketAddress for SocketAddrV4 {
+    type CSockAddr = c::sockaddr_in;
+
+    fn encode(&self) -> Self::CSockAddr {
+        encode_sockaddr_v4(self)
+    }
+}
+
+unsafe impl SocketAddress for SocketAddrV6 {
+    type CSockAddr = c::sockaddr_in6;
+
+    fn encode(&self) -> Self::CSockAddr {
+        encode_sockaddr_v6(self)
+    }
+}
+
 /// `struct sockaddr_un`
 #[cfg(unix)]
 #[derive(Clone)]
@@ -202,6 +221,27 @@ impl fmt::Debug for SocketAddrUnix {
     }
 }
 
+#[cfg(unix)]
+unsafe impl SocketAddress for SocketAddrUnix {
+    type CSockAddr = c::sockaddr_un;
+
+    fn encode(&self) -> Self::CSockAddr {
+        self.unix
+    }
+
+    unsafe fn write_sockaddr(&self, storage: *mut SocketAddrStorage) -> usize {
+        core::ptr::write(storage.cast(), self.unix);
+        self.len()
+    }
+
+    fn with_sockaddr<R>(&self, f: impl FnOnce(*const c::sockaddr, c::socklen_t) -> R) -> R {
+        f(
+            (&self.unix as *const c::sockaddr_un).cast(),
+            self.addr_len(),
+        )
+    }
+}
+
 /// `struct sockaddr_storage` as a raw struct.
 pub type SocketAddrStorage = c::sockaddr_storage;
 

src/backend/libc/net/msghdr.rs

@@ -5,15 +5,9 @@
 
 use crate::backend::c;
 use crate::backend::conv::{msg_control_len, msg_iov_len};
-#[cfg(target_os = "linux")]
-use crate::backend::net::write_sockaddr::encode_sockaddr_xdp;
-use crate::backend::net::write_sockaddr::{encode_sockaddr_v4, encode_sockaddr_v6};
 
 use crate::io::{self, IoSlice, IoSliceMut};
-#[cfg(target_os = "linux")]
-use crate::net::xdp::SocketAddrXdp;
-use crate::net::{RecvAncillaryBuffer, SendAncillaryBuffer, SocketAddrV4, SocketAddrV6};
-use crate::utils::as_ptr;
+use crate::net::{RecvAncillaryBuffer, SendAncillaryBuffer, SocketAddress};
 
 use core::mem::{size_of, zeroed, MaybeUninit};
 
@@ -66,87 +60,24 @@ pub(crate) fn with_noaddr_msghdr<R>(
     })
 }
 
-/// Create a message header intended to send with an IPv4 address.
-pub(crate) fn with_v4_msghdr<R>(
-    addr: &SocketAddrV4,
+/// Create a message header intended to send with the specified address.
+pub(crate) fn with_msghdr<R, A: SocketAddress>(
+    addr: &A,
     iov: &[IoSlice<'_>],
     control: &mut SendAncillaryBuffer<'_, '_, '_>,
     f: impl FnOnce(c::msghdr) -> R,
 ) -> R {
-    let encoded = encode_sockaddr_v4(addr);
-
-    f({
-        let mut h = zero_msghdr();
-        h.msg_name = as_ptr(&encoded) as _;
-        h.msg_namelen = size_of::<SocketAddrV4>() as _;
-        h.msg_iov = iov.as_ptr() as _;
-        h.msg_iovlen = msg_iov_len(iov.len());
-        h.msg_control = control.as_control_ptr().cast();
-        h.msg_controllen = msg_control_len(control.control_len());
-        h
-    })
-}
-
-/// Create a message header intended to send with an IPv6 address.
-pub(crate) fn with_v6_msghdr<R>(
-    addr: &SocketAddrV6,
-    iov: &[IoSlice<'_>],
-    control: &mut SendAncillaryBuffer<'_, '_, '_>,
-    f: impl FnOnce(c::msghdr) -> R,
-) -> R {
-    let encoded = encode_sockaddr_v6(addr);
-
-    f({
-        let mut h = zero_msghdr();
-        h.msg_name = as_ptr(&encoded) as _;
-        h.msg_namelen = size_of::<SocketAddrV6>() as _;
-        h.msg_iov = iov.as_ptr() as _;
-        h.msg_iovlen = msg_iov_len(iov.len());
-        h.msg_control = control.as_control_ptr().cast();
-        h.msg_controllen = msg_control_len(control.control_len());
-        h
-    })
-}
-
-/// Create a message header intended to send with a Unix address.
-#[cfg(all(unix, not(target_os = "redox")))]
-pub(crate) fn with_unix_msghdr<R>(
-    addr: &crate::net::SocketAddrUnix,
-    iov: &[IoSlice<'_>],
-    control: &mut SendAncillaryBuffer<'_, '_, '_>,
-    f: impl FnOnce(c::msghdr) -> R,
-) -> R {
-    f({
-        let mut h = zero_msghdr();
-        h.msg_name = as_ptr(&addr.unix) as _;
-        h.msg_namelen = addr.addr_len();
-        h.msg_iov = iov.as_ptr() as _;
-        h.msg_iovlen = msg_iov_len(iov.len());
-        h.msg_control = control.as_control_ptr().cast();
-        h.msg_controllen = msg_control_len(control.control_len());
-        h
-    })
-}
-
-/// Create a message header intended to send with an IPv6 address.
-#[cfg(target_os = "linux")]
-pub(crate) fn with_xdp_msghdr<R>(
-    addr: &SocketAddrXdp,
-    iov: &[IoSlice<'_>],
-    control: &mut SendAncillaryBuffer<'_, '_, '_>,
-    f: impl FnOnce(c::msghdr) -> R,
-) -> R {
-    let encoded = encode_sockaddr_xdp(addr);
-
-    f({
-        let mut h = zero_msghdr();
-        h.msg_name = as_ptr(&encoded) as _;
-        h.msg_namelen = size_of::<SocketAddrXdp>() as _;
-        h.msg_iov = iov.as_ptr() as _;
-        h.msg_iovlen = msg_iov_len(iov.len());
-        h.msg_control = control.as_control_ptr().cast();
-        h.msg_controllen = msg_control_len(control.control_len());
-        h
+    addr.with_sockaddr(|addr_ptr, addr_len| {
+        f({
+            let mut h = zero_msghdr();
+            h.msg_name = addr_ptr.cast_mut().cast();
+            h.msg_namelen = addr_len;
+            h.msg_iov = iov.as_ptr() as _;
+            h.msg_iovlen = msg_iov_len(iov.len());
+            h.msg_control = control.as_control_ptr().cast();
+            h.msg_controllen = msg_control_len(control.control_len());
+            h
+        })
     })
 }