Add sockaddr_ctl on Mac

Author: Bryant Mairs

libc-test/build.rs

@@ -177,6 +177,7 @@ fn main() {
         cfg.header("net/route.h");
         cfg.header("netinet/if_ether.h");
         cfg.header("sys/proc_info.h");
+        cfg.header("kern_control.h");
     }
 
     if bsdlike {
@@ -216,7 +217,7 @@ fn main() {
             cfg.header("sys/reg.h");
         }
     }
- 
+
     if linux || android || emscripten {
         cfg.header("malloc.h");
         cfg.header("net/ethernet.h");

src/unix/bsd/apple/mod.rs

@@ -498,6 +498,15 @@ s! {
         pub sin_tos: ::c_ushort,
         pub sin_other: ::c_ushort,
     }
+
+    pub struct sockaddr_ctl {
+        pub sc_len: ::c_uchar,
+        pub sc_family: ::c_uchar,
+        pub ss_sysaddr: ::uint16_t,
+        pub sc_id: ::uint32_t,
+        pub sc_unit: ::uint32_t,
+        pub sc_reserved: [::uint32_t; 5],
+    }
 }
 
 pub const _UTX_USERSIZE: usize = 256;