Improve ergonomics between SockaddrIn and underlying libc type (nix-r…

…ust#2328)

changelog/2328.added.md

@@ -0,0 +1 @@
+Add `From` trait implementation for conversions between `sockaddr_in` and `SockaddrIn`, `sockaddr_in6` and `SockaddrIn6`

src/sys/socket/addr.rs

@@ -919,6 +919,19 @@ impl From<SockaddrIn> for net::SocketAddrV4 {
     }
 }
 
+#[cfg(feature = "net")]
+impl From<SockaddrIn> for libc::sockaddr_in {
+    fn from(sin: SockaddrIn) -> libc::sockaddr_in {
+        sin.0
+    }
+}
+#[cfg(feature = "net")]
+impl From<libc::sockaddr_in> for SockaddrIn {
+    fn from(sin: libc::sockaddr_in) -> SockaddrIn {
+        SockaddrIn(sin)
+    }
+}
+
 #[cfg(feature = "net")]
 impl std::str::FromStr for SockaddrIn {
     type Err = net::AddrParseError;
@@ -969,6 +982,20 @@ impl SockaddrIn6 {
     }
 }
 
+#[cfg(feature = "net")]
+impl From<SockaddrIn6> for libc::sockaddr_in6 {
+    fn from(sin6: SockaddrIn6) -> libc::sockaddr_in6 {
+        sin6.0
+    }
+}
+
+#[cfg(feature = "net")]
+impl From<libc::sockaddr_in6> for SockaddrIn6 {
+    fn from(sin6: libc::sockaddr_in6) -> SockaddrIn6 {
+        SockaddrIn6(sin6)
+    }
+}
+
 #[cfg(feature = "net")]
 impl private::SockaddrLikePriv for SockaddrIn6 {}
 #[cfg(feature = "net")]