3 files changed, 54 insertions, 3 deletions
diff --git a/src/sys/socket/addr.rs b/src/sys/socket/addr.rs
index 29832b37..b479c9cd 100644
--- a/src/sys/socket/addr.rs
+++ b/src/sys/socket/addr.rs
@@ -1,5 +1,6 @@
 use super::sa_family_t;
-use {Errno, Error, Result, NixPath};
+use {Error, Result, NixPath};
+use errno::Errno;
 use libc;
 use std::{fmt, hash, mem, net, ptr, slice};
 use std::ffi::OsStr;
@@ -201,6 +202,26 @@ pub enum AddressFamily {
     Natm = libc::AF_NATM,
 }
 
+impl AddressFamily {
+    /// Create a new `AddressFamily` from an integer value retrieved from `libc`, usually from
+    /// the `sa_family` field of a `sockaddr`.
+    ///
+    /// Currently only supports these address families: Unix, Inet (v4 & v6), Netlink
+    /// and System. Returns None for unsupported or unknown address families.
+    pub fn from_i32(family: i32) -> Option<AddressFamily> {
+        match family {
+            libc::AF_UNIX => Some(AddressFamily::Unix),
+            libc::AF_INET => Some(AddressFamily::Inet),
+            libc::AF_INET6 => Some(AddressFamily::Inet6),
+            #[cfg(any(target_os = "android", target_os = "linux"))]
+            libc::AF_NETLINK => Some(AddressFamily::Netlink),
+            #[cfg(any(target_os = "macos", target_os = "macos"))]
+            libc::AF_SYSTEM => Some(AddressFamily::System),
+            _ => None
+        }
+    }
+}
+
 #[derive(Copy)]
 pub enum InetAddr {
     V4(libc::sockaddr_in),
@@ -707,6 +728,34 @@ impl SockAddr {
         format!("{}", self)
     }
 
+    /// Creates a `SockAddr` struct from libc's sockaddr.
+    ///
+    /// Supports only the following address families: Unix, Inet (v4 & v6), Netlink and System.
+    /// Returns None for unsupported families.
+    pub unsafe fn from_libc_sockaddr(addr: *const libc::sockaddr) -> Option<SockAddr> {
+        if addr.is_null() {
+            None
+        } else {
+            match AddressFamily::from_i32((*addr).sa_family as i32) {
+                Some(AddressFamily::Unix) => None,
+                Some(AddressFamily::Inet) => Some(SockAddr::Inet(
+                    InetAddr::V4(*(addr as *const libc::sockaddr_in)))),
+                Some(AddressFamily::Inet6) => Some(SockAddr::Inet(
+                    InetAddr::V6(*(addr as *const libc::sockaddr_in6)))),
+                #[cfg(any(target_os = "android", target_os = "linux"))]
+                Some(AddressFamily::Netlink) => Some(SockAddr::Netlink(
+                    NetlinkAddr(*(addr as *const libc::sockaddr_nl)))),
+                #[cfg(any(target_os = "ios", target_os = "macos"))]
+                Some(AddressFamily::System) => Some(SockAddr::SysControl(
+                    SysControlAddr(*(addr as *const sys_control::sockaddr_ctl)))),
+                // Other address families are currently not supported and simply yield a None
+                // entry instead of a proper conversion to a `SockAddr`.
+                Some(_) => None,
+                None => None,
+            }
+        }
+    }
+
     pub unsafe fn as_ffi_pair(&self) -> (&libc::sockaddr, libc::socklen_t) {
         match *self {
             SockAddr::Inet(InetAddr::V4(ref addr)) => (mem::transmute(addr), mem::size_of::<libc::sockaddr_in>() as libc::socklen_t),
diff --git a/src/sys/socket/mod.rs b/src/sys/socket/mod.rs
index cdb8b4b3..c7d6d581 100644
--- a/src/sys/socket/mod.rs
+++ b/src/sys/socket/mod.rs
@@ -1,7 +1,8 @@
 //! Socket interface functions
 //!
 //! [Further reading](http://man7.org/linux/man-pages/man7/socket.7.html)
-use {Error, Errno, Result};
+use {Error, Result};
+use errno::Errno;
 use features;
 use libc::{self, c_void, c_int, socklen_t, size_t, pid_t, uid_t, gid_t};
 use std::{mem, ptr, slice};
diff --git a/src/sys/socket/sockopt.rs b/src/sys/socket/sockopt.rs
index 98a4eeac..4741ec66 100644
--- a/src/sys/socket/sockopt.rs
+++ b/src/sys/socket/sockopt.rs
@@ -1,5 +1,6 @@
 use super::{GetSockOpt, SetSockOpt};
-use {Errno, Result};
+use Result;
+use errno::Errno;
 use sys::time::TimeVal;
 use libc::{self, c_int, uint8_t, c_void, socklen_t};
 use std::mem;