Refactor Socket::local_addr

Author: Thomasdezeeuw

src/socket.rs

@@ -198,9 +198,16 @@ impl Socket {
         sys::accept(self.inner).map(|(inner, addr)| (Socket { inner }, addr))
     }
 
-    /// Returns the socket address of the local half of this TCP connection.
+    /// Returns the socket address of the local half of this socket.
+    ///
+    /// # Notes
+    ///
+    /// Depending on the OS this may return an error if the socket is not
+    /// [bound].
+    ///
+    /// [bound]: Socket::bind
     pub fn local_addr(&self) -> io::Result<SockAddr> {
-        self.inner().local_addr()
+        sys::getsockname(self.inner)
     }
 
     /// Returns the socket address of the remote peer of this TCP connection.

src/sys/unix.rs

@@ -9,6 +9,7 @@
 #[cfg(not(target_os = "redox"))]
 use std::io::{IoSlice, IoSliceMut};
 use std::io::{Read, Write};
+use std::mem::{self, size_of_val};
 use std::net::Shutdown;
 use std::net::{self, Ipv4Addr, Ipv6Addr};
 #[cfg(feature = "all")]
@@ -21,7 +22,7 @@ use std::path::Path;
 use std::ptr;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::time::Duration;
-use std::{cmp, fmt, io, mem};
+use std::{cmp, fmt, io};
 
 use libc::{self, c_void, in6_addr, in_addr, ssize_t};
 
@@ -324,13 +325,20 @@ pub(crate) fn listen(fd: SysSocket, backlog: i32) -> io::Result<()> {
 pub(crate) fn accept(fd: SysSocket) -> io::Result<(SysSocket, SockAddr)> {
     // Safety: zeroed `sockaddr_storage` is valid.
     let mut storage: libc::sockaddr_storage = unsafe { mem::zeroed() };
-    let mut len = mem::size_of_val(&storage) as socklen_t;
+    let mut len = size_of_val(&storage) as socklen_t;
     syscall!(accept(fd, &mut storage as *mut _ as *mut _, &mut len)).map(|fd| {
         let addr = unsafe { SockAddr::from_raw_parts(&storage as *const _ as *const _, len) };
         (fd, addr)
     })
 }
 
+pub(crate) fn getsockname(fd: SysSocket) -> io::Result<SockAddr> {
+    let mut storage: libc::sockaddr_storage = unsafe { mem::zeroed() };
+    let mut len = size_of_val(&storage) as libc::socklen_t;
+    syscall!(getsockname(fd, &mut storage as *mut _ as *mut _, &mut len,))
+        .map(|_| unsafe { SockAddr::from_raw_parts(&storage as *const _ as *const _, len) })
+}
+
 /// Unix only API.
 impl crate::Socket {
     /// Accept a new incoming connection from this listener.
@@ -426,17 +434,6 @@ pub struct Socket {
 }
 
 impl Socket {
-    pub fn local_addr(&self) -> io::Result<SockAddr> {
-        let mut storage: libc::sockaddr_storage = unsafe { mem::zeroed() };
-        let mut len = mem::size_of_val(&storage) as libc::socklen_t;
-        syscall!(getsockname(
-            self.fd,
-            &mut storage as *mut _ as *mut _,
-            &mut len,
-        ))?;
-        Ok(unsafe { SockAddr::from_raw_parts(&storage as *const _ as *const _, len) })
-    }
-
     pub fn peer_addr(&self) -> io::Result<SockAddr> {
         let mut storage: libc::sockaddr_storage = unsafe { mem::zeroed() };
         let mut len = mem::size_of_val(&storage) as libc::socklen_t;
@@ -1052,7 +1049,7 @@ impl fmt::Debug for Socket {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let mut f = f.debug_struct("Socket");
         f.field("fd", &self.fd);
-        if let Ok(addr) = self.local_addr() {
+        if let Ok(addr) = getsockname(self.fd) {
             f.field("local_addr", &addr);
         }
         if let Ok(addr) = self.peer_addr() {

src/sys/windows.rs

@@ -10,7 +10,7 @@ use std::cmp;
 use std::fmt;
 use std::io;
 use std::io::{IoSlice, IoSliceMut, Read, Write};
-use std::mem;
+use std::mem::{self, size_of_val};
 use std::net::Shutdown;
 use std::net::{self, Ipv4Addr, Ipv6Addr};
 use std::os::windows::prelude::*;
@@ -169,7 +169,7 @@ pub(crate) fn listen(socket: SysSocket, backlog: i32) -> io::Result<()> {
 pub(crate) fn accept(socket: SysSocket) -> io::Result<(SysSocket, SockAddr)> {
     // Safety: zeroed `SOCKADDR_STORAGE` is valid.
     let mut storage: SOCKADDR_STORAGE = unsafe { mem::zeroed() };
-    let mut len = mem::size_of_val(&storage) as c_int;
+    let mut len = size_of_val(&storage) as c_int;
     syscall!(
         accept(socket, &mut storage as *mut _ as *mut _, &mut len),
         PartialEq::eq,
@@ -181,6 +181,18 @@ pub(crate) fn accept(socket: SysSocket) -> io::Result<(SysSocket, SockAddr)> {
     })
 }
 
+pub(crate) fn getsockname(socket: SysSocket) -> io::Result<SockAddr> {
+    // Safety: zeroed `SOCKADDR_STORAGE` is valid.
+    let mut storage: SOCKADDR_STORAGE = unsafe { mem::zeroed() };
+    let mut len = size_of_val(&storage) as c_int;
+    syscall!(
+        getsockname(socket, &mut storage as *mut _ as *mut _, &mut len),
+        PartialEq::eq,
+        sock::SOCKET_ERROR
+    )
+    .map(|_| unsafe { SockAddr::from_raw_parts(&storage as *const _ as *const _, len) })
+}
+
 impl crate::Socket {
     /// Sets `HANDLE_FLAG_INHERIT` to zero using `SetHandleInformation`.
     pub fn set_no_inherit(&self) -> io::Result<()> {
@@ -199,20 +211,6 @@ pub struct Socket {
 }
 
 impl Socket {
-    pub fn local_addr(&self) -> io::Result<SockAddr> {
-        unsafe {
-            let mut storage: SOCKADDR_STORAGE = mem::zeroed();
-            let mut len = mem::size_of_val(&storage) as c_int;
-            if sock::getsockname(self.socket, &mut storage as *mut _ as *mut _, &mut len) != 0 {
-                return Err(last_error());
-            }
-            Ok(SockAddr::from_raw_parts(
-                &storage as *const _ as *const _,
-                len,
-            ))
-        }
-    }
-
     pub fn peer_addr(&self) -> io::Result<SockAddr> {
         unsafe {
             let mut storage: SOCKADDR_STORAGE = mem::zeroed();
@@ -894,7 +892,7 @@ impl fmt::Debug for Socket {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let mut f = f.debug_struct("Socket");
         f.field("socket", &self.socket);
-        if let Ok(addr) = self.local_addr() {
+        if let Ok(addr) = getsockname(self.socket) {
             f.field("local_addr", &addr);
         }
         if let Ok(addr) = self.peer_addr() {