diff --git a/babeld/util.h b/babeld/util.h
new file mode 100644
index 0000000..d653b61
--- /dev/null
+++ b/babeld/util.h
@@ -0,0 +1,168 @@
+/*  
+ *  This file is free software: you may copy, redistribute and/or modify it  
+ *  under the terms of the GNU General Public License as published by the  
+ *  Free Software Foundation, either version 2 of the License, or (at your  
+ *  option) any later version.  
+ *  
+ *  This file is distributed in the hope that it will be useful, but  
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of  
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU  
+ *  General Public License for more details.  
+ *  
+ *  You should have received a copy of the GNU General Public License  
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.  
+ *  
+ * This file incorporates work covered by the following copyright and  
+ * permission notice:  
+ *  
+Copyright (c) 2007, 2008 by Juliusz Chroboczek
+Copyright 2011 by Matthieu Boutier and Juliusz Chroboczek
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+
+#include "babeld.h"
+#include "babel_main.h"
+#include "log.h"
+
+#if defined(i386) || defined(__mc68020__) || defined(__x86_64__)
+#define DO_NTOHS(_d, _s) do { _d = ntohs(*(unsigned short*)(_s)); } while(0)
+#define DO_NTOHL(_d, _s) do { _d = ntohl(*(unsigned*)(_s)); } while(0)
+#define DO_HTONS(_d, _s) do { *(unsigned short*)(_d) = htons(_s); } while(0)
+#define DO_HTONL(_d, _s) do { *(unsigned*)(_d) = htonl(_s); } while(0)
+/* Some versions of gcc seem to be buggy, and ignore the packed attribute.
+   Disable this code until the issue is clarified. */
+/* #elif defined __GNUC__*/
+#elif 0
+struct __us { unsigned short x __attribute__((packed)); };
+#define DO_NTOHS(_d, _s) \
+    do { _d = ntohs(((const struct __us*)(_s))->x); } while(0)
+#define DO_HTONS(_d, _s) \
+    do { ((struct __us*)(_d))->x = htons(_s); } while(0)
+#else
+#define DO_NTOHS(_d, _s) \
+    do { short _dd; \
+         memcpy(&(_dd), (_s), 2); \
+         _d = ntohs(_dd); } while(0)
+#define DO_HTONS(_d, _s) \
+    do { unsigned short _dd; \
+         _dd = htons(_s); \
+         memcpy((_d), &(_dd), 2); } while(0)
+#endif
+
+static inline int
+seqno_compare(unsigned short s1, unsigned short s2)
+{
+    if(s1 == s2)
+        return 0;
+    else
+        return ((s2 - s1) & 0x8000) ? 1 : -1;
+}
+
+static inline short
+seqno_minus(unsigned short s1, unsigned short s2)
+{
+    return (short)((s1 - s2) & 0xFFFF);
+}
+
+static inline unsigned short
+seqno_plus(unsigned short s, int plus)
+{
+    return ((s + plus) & 0xFFFF);
+}
+
+unsigned roughly(unsigned value);
+void timeval_minus(struct timeval *d,
+                   const struct timeval *s1, const struct timeval *s2);
+unsigned timeval_minus_msec(const struct timeval *s1, const struct timeval *s2)
+    ATTRIBUTE ((pure));
+void timeval_add_msec(struct timeval *d,
+                      const struct timeval *s, const int msecs);
+void set_timeout (struct timeval *timeout, int msecs);
+int timeval_compare(const struct timeval *s1, const struct timeval *s2)
+    ATTRIBUTE ((pure));
+void timeval_min(struct timeval *d, const struct timeval *s);
+void timeval_min_sec(struct timeval *d, time_t secs);
+int parse_msec(const char *string) ATTRIBUTE ((pure));
+void do_debugf(const char *format, ...)
+    ATTRIBUTE ((format (printf, 1, 2))) COLD;
+int in_prefix(const unsigned char *restrict address,
+              const unsigned char *restrict prefix, unsigned char plen)
+    ATTRIBUTE ((pure));
+unsigned char *mask_prefix(unsigned char *restrict ret,
+                           const unsigned char *restrict prefix,
+                           unsigned char plen);
+const char *format_address(const unsigned char *address);
+const char *format_prefix(const unsigned char *address, unsigned char prefix);
+const char *format_eui64(const unsigned char *eui);
+int parse_address(const char *address, unsigned char *addr_r, int *af_r);
+int parse_net(const char *ifp, unsigned char *prefix_r, unsigned char *plen_r,
+              int *af_r);
+int parse_eui64(const char *eui, unsigned char *eui_r);
+int wait_for_fd(int direction, int fd, int msecs);
+int martian_prefix(const unsigned char *prefix, int plen) ATTRIBUTE ((pure));
+int linklocal(const unsigned char *address) ATTRIBUTE ((pure));
+int v4mapped(const unsigned char *address) ATTRIBUTE ((pure));
+void v4tov6(unsigned char *dst, const unsigned char *src);
+void inaddr_to_uchar(unsigned char *dest, const struct in_addr *src);
+void uchar_to_inaddr(struct in_addr *dest, const unsigned char *src);
+void in6addr_to_uchar(unsigned char *dest, const struct in6_addr *src);
+void uchar_to_in6addr(struct in6_addr *dest, const unsigned char *src);
+int daemonise(void);
+
+/* If debugging is disabled, we want to avoid calling format_address
+   for every omitted debugging message.  So debug is a macro.  But
+   vararg macros are not portable. */
+#if defined NO_DEBUG
+
+#if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
+#define debugf(...) do {} while(0)
+#elif defined __GNUC__
+#define debugf(_args...) do {} while(0)
+#else
+static inline void debugf(int level, const char *format, ...) { return; }
+#endif
+
+#else /* NO_DEBUG */
+
+/* some levels */
+#define BABEL_DEBUG_COMMON      (1 << 0)
+#define BABEL_DEBUG_KERNEL      (1 << 1)
+#define BABEL_DEBUG_FILTER      (1 << 2)
+#define BABEL_DEBUG_TIMEOUT     (1 << 3)
+#define BABEL_DEBUG_IF          (1 << 4)
+#define BABEL_DEBUG_ROUTE       (1 << 5)
+#define BABEL_DEBUG_ALL         (0xFFFF)
+
+#if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
+#define debugf(level, ...) \
+do { \
+if(UNLIKELY(debug & level)) do_debugf(__VA_ARGS__);     \
+} while(0)
+#elif defined __GNUC__
+#define debugf(level, _args...) \
+do { \
+if(UNLIKELY(debug & level)) do_debugf(_args);   \
+} while(0)
+#else
+static inline void debugf(int level, const char *format, ...) { return; }
+#endif
+
+#endif /* NO_DEBUG */
+