Second night's commit.

We're a bit closer to something sane, now. We can wrap, but not unwrap,
packets.

Asymmetric encryption is *big*. encrypted text with a 4096-bit RSA
public key is 512 bytes. We can't fragment yet. Fortunately, this
isn't an infinite regress once we *can* fragment.

Performance is still a big question mark, of course.

There may still be endianness issues hanging around.

The eid<->rloc map is almost certainly far, far too slow to be of
any use in the real world.

pass-1/util.h

@@ -0,0 +1,22 @@
+#ifndef _UTIL_H_
+#define _UTIL_H
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <netinet/ip.h>
+
+#define info(msg, ...) { fprintf( stdout, msg, ##__VA_ARGS__ ) ; fprintf( stdout, "\n" ); }
+#define warn(msg, ...) { fprintf( stderr, msg, ##__VA_ARGS__ ) ; fprintf( stderr, "\n" ); }
+
+#define IPPROTO_HIDE_EID 0xfd
+
+void* xmalloc( size_t bytes );
+int create_tun( const char* name );
+void compute_ip_checksum( struct iphdr* pkt );
+
+
+int link_set_up( char *link_name, int state );
+
+#endif