Remove libc from public API

Author: Thomasdezeeuw

Cargo.toml

@@ -69,8 +69,11 @@ all = []
 
 [package.metadata.cargo_check_external_types]
 allowed_external_types = [
-  "libc::*",
   # Referenced via a type alias.
+  "libc::socklen_t",
+  "libc::unix::bsd::socklen_t", # libc::socklen_t isn't always detected.
+  "libc::sa_family_t",
+  "libc::unix::bsd::sa_family_t", # libc::sa_family_t is always detected.
   "windows_sys::Win32::Networking::WinSock::socklen_t",
   "windows_sys::Win32::Networking::WinSock::ADDRESS_FAMILY",
 ]

src/sys/unix.rs

@@ -83,7 +83,7 @@ use crate::{Domain, Protocol, SockAddr, SockAddrStorage, TcpKeepalive, Type};
 #[cfg(not(target_os = "redox"))]
 use crate::{MsgHdr, MsgHdrMut, RecvFlags};
 
-pub(crate) use libc::c_int;
+pub(crate) use std::ffi::c_int;
 
 // Used in `Domain`.
 pub(crate) use libc::{AF_INET, AF_INET6, AF_UNIX};