More PR feedback

3 files changed, 12 insertions, 56 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c87abc4b..c6b5dad1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -40,6 +40,8 @@ This project adheres to [Semantic Versioning](https://semver.org/).
   ([#1964](https://github.com/nix-rust/nix/pull/1964))
 - Fix: send ETH_P_ALL in htons format 
   ([#1925](https://github.com/nix-rust/nix/pull/1925))
+- Fix: `recvmsg` now sets the length of the received `sockaddr_un` field
+  correctly on Linux platforms. ([#2041](https://github.com/nix-rust/nix/pull/2041))
 
 ### Removed
 
diff --git a/src/sys/socket/addr.rs b/src/sys/socket/addr.rs
index 12cdc7a4..88bd6f5a 100644
--- a/src/sys/socket/addr.rs
+++ b/src/sys/socket/addr.rs
@@ -931,14 +931,17 @@ pub trait SockaddrLike: private::SockaddrLikePriv {
 
     /// Set the length of this socket address
     ///
-    /// This method may only be called on socket addresses whose lenghts are dynamic, and it
+    /// This method may only be called on socket addresses whose lengths are dynamic, and it
     /// returns an error if called on a type whose length is static.
     ///
     /// # Safety
     ///
     /// `new_length` must be a valid length for this type of address. Specifically, reads of that
     /// length from `self` must be valid.
-    unsafe fn set_length(&mut self, new_length: usize) -> std::result::Result<(), SocketAddressLengthNotDynamic>;
+    #[doc(hidden)]
+    unsafe fn set_length(&mut self, _new_length: usize) -> std::result::Result<(), SocketAddressLengthNotDynamic> {
+        Err(SocketAddressLengthNotDynamic)
+    }
 }
 
 /// The error returned by [`SockaddrLike::set_length`] on an address whose length is statically
@@ -984,10 +987,6 @@ impl SockaddrLike for () {
     fn len(&self) -> libc::socklen_t {
         0
     }
-
-    unsafe fn set_length(&mut self, _new_length: usize) -> std::result::Result<(), SocketAddressLengthNotDynamic> {
-        Err(SocketAddressLengthNotDynamic)
-    }
 }
 
 /// An IPv4 socket address
@@ -1057,10 +1056,6 @@ impl SockaddrLike for SockaddrIn {
         }
         Some(Self(ptr::read_unaligned(addr as *const _)))
     }
-
-    unsafe fn set_length(&mut self, _new_length: usize) -> std::result::Result<(), SocketAddressLengthNotDynamic> {
-        Err(SocketAddressLengthNotDynamic)
-    }
 }
 
 #[cfg(feature = "net")]
@@ -1180,10 +1175,6 @@ impl SockaddrLike for SockaddrIn6 {
         }
         Some(Self(ptr::read_unaligned(addr as *const _)))
     }
-
-    unsafe fn set_length(&mut self, _new_length: usize) -> std::result::Result<(), SocketAddressLengthNotDynamic> {
-        Err(SocketAddressLengthNotDynamic)
-    }
 }
 
 #[cfg(feature = "net")]
@@ -1415,19 +1406,7 @@ impl SockaddrLike for SockaddrStorage {
     unsafe fn set_length(&mut self, new_length: usize) -> std::result::Result<(), SocketAddressLengthNotDynamic> {
         match self.as_unix_addr_mut() {
             Some(addr) => {
-                cfg_if! {
-                    if #[cfg(any(target_os = "android",
-                                 target_os = "fuchsia",
-                                 target_os = "illumos",
-                                 target_os = "linux",
-                                 target_os = "redox",
-                        ))] {
-                        addr.sun_len = new_length as u8;
-                    } else {
-                        addr.sun.sun_len = new_length as u8;
-                    }
-                }
-                Ok(())
+                addr.set_length(new_length)
             },
             None => Err(SocketAddressLengthNotDynamic),
         }
@@ -1825,10 +1804,6 @@ pub mod netlink {
             }
             Some(Self(ptr::read_unaligned(addr as *const _)))
         }
-
-        unsafe fn set_length(&mut self, _new_length: usize) -> std::result::Result<(), SocketAddressLengthNotDynamic> {
-            Err(SocketAddressLengthNotDynamic)
-        }
     }
 
     impl AsRef<libc::sockaddr_nl> for NetlinkAddr {
@@ -1878,10 +1853,6 @@ pub mod alg {
             }
             Some(Self(ptr::read_unaligned(addr as *const _)))
         }
-
-        unsafe fn set_length(&mut self, _new_length: usize) -> std::result::Result<(), SocketAddressLengthNotDynamic> {
-            Err(SocketAddressLengthNotDynamic)
-        }
     }
 
     impl AsRef<libc::sockaddr_alg> for AlgAddr {
@@ -1981,7 +1952,7 @@ pub mod sys_control {
     use std::{fmt, mem, ptr};
     use std::os::unix::io::RawFd;
     use crate::{Errno, Result};
-    use super::{private, SockaddrLike, SocketAddressLengthNotDynamic};
+    use super::{private, SockaddrLike};
 
     // FIXME: Move type into `libc`
     #[repr(C)]
@@ -2022,10 +1993,6 @@ pub mod sys_control {
             }
             Some(Self(ptr::read_unaligned(addr as *const _)))
         }
-
-        unsafe fn set_length(&mut self, _new_length: usize) -> std::result::Result<(), SocketAddressLengthNotDynamic> {
-            Err(SocketAddressLengthNotDynamic)
-        }
     }
 
     impl AsRef<libc::sockaddr_ctl> for SysControlAddr {
@@ -2090,7 +2057,7 @@ pub mod sys_control {
 mod datalink {
     feature! {
     #![feature = "net"]
-    use super::{fmt, mem, private, ptr, SockaddrLike, SocketAddressLengthNotDynamic};
+    use super::{fmt, mem, private, ptr, SockaddrLike};
 
     /// Hardware Address
     #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
@@ -2168,10 +2135,6 @@ mod datalink {
             }
             Some(Self(ptr::read_unaligned(addr as *const _)))
         }
-
-        unsafe fn set_length(&mut self, _new_length: usize) -> std::result::Result<(), SocketAddressLengthNotDynamic> {
-            Err(SocketAddressLengthNotDynamic)
-        }
     }
 
     impl AsRef<libc::sockaddr_ll> for LinkAddr {
@@ -2197,7 +2160,7 @@ mod datalink {
 mod datalink {
     feature! {
     #![feature = "net"]
-    use super::{fmt, mem, private, ptr, SockaddrLike, SocketAddressLengthNotDynamic};
+    use super::{fmt, mem, private, ptr, SockaddrLike};
 
     /// Hardware Address
     #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
@@ -2296,10 +2259,6 @@ mod datalink {
             }
             Some(Self(ptr::read_unaligned(addr as *const _)))
         }
-
-        unsafe fn set_length(&mut self, _new_length: usize) -> std::result::Result<(), SocketAddressLengthNotDynamic> {
-            Err(SocketAddressLengthNotDynamic)
-        }
     }
 
     impl AsRef<libc::sockaddr_dl> for LinkAddr {
@@ -2307,7 +2266,6 @@ mod datalink {
             &self.0
         }
     }
-
     }
 }
 
@@ -2348,10 +2306,6 @@ pub mod vsock {
             }
             Some(Self(ptr::read_unaligned(addr as *const _)))
         }
-
-        unsafe fn set_length(&mut self, _new_length: usize) -> std::result::Result<(), SocketAddressLengthNotDynamic> {
-            Err(SocketAddressLengthNotDynamic)
-        }
     }
 
     impl AsRef<libc::sockaddr_vm> for VsockAddr {
diff --git a/src/sys/socket/mod.rs b/src/sys/socket/mod.rs
index c77bc961..4ca12997 100644
--- a/src/sys/socket/mod.rs
+++ b/src/sys/socket/mod.rs
@@ -2053,7 +2053,7 @@ pub fn recvmsg<'a, 'outer, 'inner, S>(fd: RawFd, iov: &'outer mut [IoSliceMut<'i
     where S: SockaddrLike + 'a,
     'inner: 'outer
 {
-    let mut address = mem::MaybeUninit::zeroed();
+    let mut address = mem::MaybeUninit::uninit();
 
     let (msg_control, msg_controllen) = cmsg_buffer.as_mut()
         .map(|v| (v.as_mut_ptr(), v.capacity()))