linux: add VSOCK struct and constants

Add struct sockaddr_vm and VMADDR_ constants to use
VSOCK on Linux. VSOCK is present since Linux 3.9

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>

Author: stefano-garzarella

src/unix/linux_like/linux/mod.rs

@@ -474,6 +474,14 @@ s! {
         pub cookie: u32,
         pub len: u32
     }
+
+    pub struct sockaddr_vm {
+        pub svm_family: ::sa_family_t,
+        pub svm_reserved1: ::c_ushort,
+        pub svm_port: ::c_uint,
+        pub svm_cid: ::c_uint,
+        pub svm_zero: [u8; 4]
+    }
 }
 
 s_no_extra_traits!{
@@ -2000,6 +2008,13 @@ pub const ALG_SET_AEAD_AUTHSIZE: ::c_int = 5;
 pub const ALG_OP_DECRYPT: ::c_int = 0;
 pub const ALG_OP_ENCRYPT: ::c_int = 1;
 
+// uapi/linux/vm_sockets.h
+pub const VMADDR_CID_ANY: ::c_uint = 0xFFFFFFFF;
+pub const VMADDR_CID_HYPERVISOR: ::c_uint = 0;
+pub const VMADDR_CID_RESERVED: ::c_uint = 1;
+pub const VMADDR_CID_HOST: ::c_uint = 2;
+pub const VMADDR_PORT_ANY: ::c_uint = 0xFFFFFFFF;
+
 // uapi/linux/inotify.h
 pub const IN_ACCESS:        u32 = 0x0000_0001;
 pub const IN_MODIFY:        u32 = 0x0000_0002;