SCTP support for FreeBSD, NetBSD

Notification and log `union` types are exposed as partially-opaque structs
for now, until libc targets a version of Rust which supports unions.

Author: jack-pappas

libc-test/build.rs

@@ -244,9 +244,12 @@ fn main() {
     if linux || android {
         cfg.header("sys/fsuid.h");
 
-        // DCCP support
         if !uclibc && !musl && !emscripten {
+            // DCCP support
             cfg.header("linux/dccp.h");
+
+            // SCTP support
+            //cfg.header("netinet/sctp.h");
         }
     }
 
@@ -258,6 +261,9 @@ fn main() {
         cfg.header("sys/ipc.h");
         cfg.header("sys/msg.h");
         cfg.header("sys/shm.h");
+
+        // SCTP support
+        cfg.header("netinet/sctp.h");
     }
 
     if netbsd {
@@ -267,6 +273,9 @@ fn main() {
 
         // DCCP support
         cfg.header("netinet/dccp.h");
+
+        // SCTP support
+        cfg.header("netinet/sctp.h");
     }
 
     if openbsd {
@@ -343,6 +352,8 @@ fn main() {
             "type_" if linux &&
                 (struct_ == "input_event" || struct_ == "input_mask" ||
                  struct_ == "ff_effect") => "type".to_string(),
+            "type_" if freebsd &&
+                (struct_ == "sctp_error_missing_param") => "type".to_string(),
             s => s.to_string(),
         }
     });
@@ -352,6 +363,12 @@ fn main() {
             // sighandler_t is crazy across platforms
             "sighandler_t" => true,
 
+            // Temporarily skip the 'sctp_nets' type for FreeBSD,
+            // it's currently just an alias for c_void since the true
+            // type layout is very complex and it's only ever used
+            // through a pointer (e.g. sctp_nets*).
+            "sctp_nets" if freebsd => true,
+
             _ => false
         }
     });
@@ -384,6 +401,9 @@ fn main() {
             // header conflicts when including them with all the other structs.
             "termios2" => true,
 
+            // This was added in FreeBSD 11
+            "sctp_error_auth_invalid_hmac" if freebsd => true,
+
             _ => false
         }
     });
@@ -452,6 +472,14 @@ fn main() {
             "HW_MAXID" |
             "USER_MAXID" if freebsd => true,
 
+            // These constants were added in FreeBSD 11.
+            "SCTP_INTERLEAVING_SUPPORTED" |
+            "SCTP_IDATA" |
+            "SCTP_IFORWARD_CUM_TSN" |
+            "SCTP_PR_SCTP_PRIO" |
+            "SCTP_ASSOC_SUPPORTS_INTERLEAVING" |
+            "SCTP_NOHEARTBEAT" if freebsd => true,
+
             // These OSX constants are removed in Sierra.
             // https://developer.apple.com/library/content/releasenotes/General/APIDiffsMacOS10_12/Swift/Darwin.html
             "KERN_KDENABLE_BG_TRACE" if apple => true,