diff --git a/babeld/babel_interface.h b/babeld/babel_interface.h
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+++ b/babeld/babel_interface.h
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+/*  
+ *  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 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.
+*/
+
+#ifndef BABEL_INTERFACE_H
+#define BABEL_INTERFACE_H
+
+#include <zebra.h>
+#include "zclient.h"
+
+/* babeld interface informations */
+struct babel_interface {
+    unsigned short flags;                     /* see below */
+    unsigned short cost;
+    struct timeval hello_timeout;
+    struct timeval update_timeout;
+    struct timeval flush_timeout;
+    struct timeval update_flush_timeout;
+    unsigned char *ipv4;
+    int buffered;
+    int bufsize;
+    char have_buffered_hello;
+    char have_buffered_id;
+    char have_buffered_nh;
+    char have_buffered_prefix;
+    unsigned char buffered_id[16];
+    unsigned char buffered_nh[4];
+    unsigned char buffered_prefix[16];
+    unsigned char *sendbuf;
+    struct buffered_update *buffered_updates;
+    int num_buffered_updates;
+    int update_bufsize;
+    time_t bucket_time;
+    unsigned int bucket;
+    time_t activity_time;
+    unsigned short hello_seqno;
+    unsigned hello_interval;
+    unsigned update_interval;
+
+    /* For filter type slot. */
+#define BABEL_FILTER_IN  0
+#define BABEL_FILTER_OUT 1
+#define BABEL_FILTER_MAX 2
+    struct access_list *list[BABEL_FILTER_MAX];               /* Access-list. */
+    struct prefix_list *prefix[BABEL_FILTER_MAX];             /* Prefix-list. */
+};
+
+typedef struct babel_interface babel_interface_nfo;
+static inline babel_interface_nfo* babel_get_if_nfo(struct interface *ifp)
+{
+    return ((babel_interface_nfo*) ifp->info);
+}
+
+/* babel_interface_nfo flags */
+#define BABEL_IF_WIRED         (1 << 1)
+#define BABEL_IF_SPLIT_HORIZON (1 << 2)
+#define BABEL_IF_LQ            (1 << 3)
+#define BABEL_IF_IS_ENABLE     (1 << 4)
+
+static inline int
+if_up(struct interface *ifp)
+{
+    return (if_is_up(ifp) &&
+            ifp->connected != NULL &&
+            (babel_get_if_nfo(ifp)->flags & BABEL_IF_IS_ENABLE));
+}
+
+/* types:
+ struct interface _ifp, struct listnode node */
+#define FOR_ALL_INTERFACES(_ifp, _node)                                              \
+    for(ALL_LIST_ELEMENTS_RO(iflist, _node, _ifp))
+
+/* types:
+ struct interface *ifp, struct connected *_connected, struct listnode *node */
+#define FOR_ALL_INTERFACES_ADDRESSES(ifp, _connected, _node)                   \
+    for(ALL_LIST_ELEMENTS_RO(ifp->connected, _node, _connected))
+
+struct buffered_update {
+    unsigned char id[8];
+    unsigned char prefix[16];
+    unsigned char plen;
+    unsigned char pad[3];
+};
+
+
+/* init function */
+void babel_if_init(void);
+
+/* Callback functions for zebra client */
+int babel_interface_up (int, struct zclient *, zebra_size_t);
+int babel_interface_down (int, struct zclient *, zebra_size_t);
+int babel_interface_add (int, struct zclient *, zebra_size_t);
+int babel_interface_delete (int, struct zclient *, zebra_size_t);
+int babel_interface_address_add (int, struct zclient *, zebra_size_t);
+int babel_interface_address_delete (int, struct zclient *, zebra_size_t);
+
+/* others functions */
+int interface_idle(babel_interface_nfo *);
+unsigned jitter(babel_interface_nfo *, int);
+unsigned update_jitter(babel_interface_nfo *babel_ifp, int urgent);
+/* return "true" if "address" is one of our ipv6 addresses */
+int is_interface_ll_address(struct interface *ifp, const unsigned char *address);
+/* Send retraction to all, and reset all interfaces statistics. */
+void babel_interface_close_all(void);
+
+
+#endif