https://github.com/rust-lang/libc/issues/3711

--- cargo-crates/libc-0.2.153/src/unix/bsd/freebsdlike/mod.rs.orig	2006-07-24 01:21:28 UTC
+++ cargo-crates/libc-0.2.153/src/unix/bsd/freebsdlike/mod.rs
@@ -1015,6 +1015,37 @@ pub const LOCAL_PEERCRED: ::c_int = 1;
 
 pub const LOCAL_PEERCRED: ::c_int = 1;
 
+// net/route.h
+pub const RTF_GATEWAY: ::c_int = 0x2;
+pub const RTA_IFP: ::c_int = 0x10;
+pub const RTAX_DST: ::c_int = 0;
+pub const RTAX_GATEWAY: ::c_int = 1;
+pub const RTAX_NETMASK: ::c_int = 2;
+pub const RTAX_IFP: ::c_int = 4;
+pub const RTAX_BRD: ::c_int = 7;
+pub const RTAX_MAX: ::c_int = 8;
+pub const RTM_VERSION: ::c_int = 5;
+
+// Message types
+pub const RTM_ADD: ::c_int = 0x1;
+pub const RTM_DELETE: ::c_int = 0x2;
+pub const RTM_CHANGE: ::c_int = 0x3;
+pub const RTM_GET: ::c_int = 0x4;
+pub const RTM_LOSING: ::c_int = 0x5;
+pub const RTM_REDIRECT: ::c_int = 0x6;
+pub const RTM_MISS: ::c_int = 0x7;
+pub const RTM_LOCK: ::c_int = 0x8;
+pub const RTM_OLDADD: ::c_int = 0x9;
+pub const RTM_OLDDEL: ::c_int = 0xa;
+pub const RTM_RESOLVE: ::c_int = 0xb;
+pub const RTM_NEWADDR: ::c_int = 0xc;
+pub const RTM_DELADDR: ::c_int = 0xd;
+pub const RTM_IFINFO: ::c_int = 0xe;
+pub const RTM_NEWMADDR: ::c_int = 0xf;
+pub const RTM_DELMADDR: ::c_int = 0x10;
+pub const RTM_IFANNOUNCE: ::c_int = 0x11;
+pub const RTM_IEEE80211: ::c_int = 0x12;
+
 pub const SHUT_RD: ::c_int = 0;
 pub const SHUT_WR: ::c_int = 1;
 pub const SHUT_RDWR: ::c_int = 2;