[HICN-554] hicn-light refactoring

Change-Id: I36f2d393741d4502ce14d3791158e43e3e9cd4cf
Signed-off-by: Jordan Augé <jordan.auge+fdio@cisco.com>

9 files changed, 658 insertions, 76 deletions

diff --git a/lib/includes/CMakeLists.txt b/lib/includes/CMakeLists.txt
index 12529bd57..6184f4708 100644
--- a/lib/includes/CMakeLists.txt
+++ b/lib/includes/CMakeLists.txt
@@ -23,6 +23,7 @@ set(LIBHICN_HEADER_FILES
   ${CMAKE_CURRENT_SOURCE_DIR}/hicn/common.h
   ${CMAKE_CURRENT_SOURCE_DIR}/hicn/compat.h
   ${CMAKE_CURRENT_SOURCE_DIR}/hicn/error.h
+  ${CMAKE_CURRENT_SOURCE_DIR}/hicn/face.h
   ${CMAKE_CURRENT_SOURCE_DIR}/hicn/header.h
   ${CMAKE_CURRENT_SOURCE_DIR}/hicn/mapme.h
   ${CMAKE_CURRENT_SOURCE_DIR}/hicn/name.h
diff --git a/lib/includes/hicn/base.h b/lib/includes/hicn/base.h
index d8a79a9c2..3112d1140 100644
--- a/lib/includes/hicn/base.h
+++ b/lib/includes/hicn/base.h
@@ -27,7 +27,7 @@
 #define HICN_DEFAULT_TTL 254
 
 typedef u32 hicn_faceid_t;
-typedef u8 hicn_pathlabel_t;
+typedef u32 hicn_pathlabel_t;
 typedef u32 hicn_lifetime_t;
 
 #define HICN_MAX_LIFETIME_SCALED 0xFFFF
@@ -95,12 +95,16 @@ HICN_TYPE(int x, int y, int z, int t)
 #endif
 
 #define HICN_TYPE_IPV4_TCP     HICN_TYPE(IPPROTO_IP,   IPPROTO_TCP,    IPPROTO_NONE, IPPROTO_NONE)
+#define HICN_TYPE_IPV4_UDP     HICN_TYPE(IPPROTO_IP,   IPPROTO_UDP,    IPPROTO_NONE, IPPROTO_NONE)
 #define HICN_TYPE_IPV4_ICMP    HICN_TYPE(IPPROTO_IP,   IPPROTO_ICMP,   IPPROTO_NONE, IPPROTO_NONE)
 #define HICN_TYPE_IPV6_TCP     HICN_TYPE(IPPROTO_IPV6, IPPROTO_TCP,    IPPROTO_NONE, IPPROTO_NONE)
+#define HICN_TYPE_IPV6_UDP     HICN_TYPE(IPPROTO_IPV6, IPPROTO_UDP,    IPPROTO_NONE, IPPROTO_NONE)
 #define HICN_TYPE_IPV6_ICMP    HICN_TYPE(IPPROTO_IPV6, IPPROTO_ICMPV6, IPPROTO_NONE, IPPROTO_NONE)
 #define HICN_TYPE_IPV4_TCP_AH  HICN_TYPE(IPPROTO_IP,   IPPROTO_TCP,    IPPROTO_NONE, IPPROTO_NONE)
+#define HICN_TYPE_IPV4_UDP_AH  HICN_TYPE(IPPROTO_IP,   IPPROTO_UDP,    IPPROTO_NONE, IPPROTO_NONE)
 #define HICN_TYPE_IPV4_ICMP_AH HICN_TYPE(IPPROTO_IP,   IPPROTO_ICMP,   IPPROTO_NONE, IPPROTO_NONE)
 #define HICN_TYPE_IPV6_TCP_AH  HICN_TYPE(IPPROTO_IPV6, IPPROTO_TCP,    IPPROTO_AH,   IPPROTO_NONE)
+#define HICN_TYPE_IPV6_UDP_AH  HICN_TYPE(IPPROTO_IPV6, IPPROTO_UDP,    IPPROTO_AH,   IPPROTO_NONE)
 #define HICN_TYPE_IPV6_ICMP_AH HICN_TYPE(IPPROTO_IPV6, IPPROTO_ICMPV6, IPPROTO_AH,   IPPROTO_NONE)
 #define HICN_TYPE_NONE         HICN_TYPE(IPPROTO_NONE, IPPROTO_NONE,   IPPROTO_NONE, IPPROTO_NONE)
 
@@ -127,8 +131,9 @@ typedef enum
  * NOTE: this computation is not (yet) part of the hICN specification.
  */
 
+// XXX TODO deprecate TODO XXX
 #define HICN_PATH_LABEL_MASK 0xF000	/* 1000 0000 0000 0000 */
-#define HICN_PATH_LABEL_SIZE 8
+#define HICN_PATH_LABEL_SIZE 8 /* XXX in bits ? */
 
 /**
  * @brief Path label update
diff --git a/lib/includes/hicn/face.h b/lib/includes/hicn/face.h
new file mode 100644
index 000000000..45a1b97da
--- /dev/null
+++ b/lib/includes/hicn/face.h
@@ -0,0 +1,213 @@
+/*
+ * Copyright (c) 2017-2019 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * \file face.h
+ * \brief Face abstraction
+ */
+#ifndef HICN_FACE_H
+#define HICN_FACE_H
+
+#ifndef SPACES
+#define SPACES(x) x
+#endif
+#ifndef SPACE
+#define SPACE 1
+#endif
+#ifndef NULLTERM
+#define NULLTERM 1
+#endif
+
+#include <hicn/policy.h>
+
+#include <hicn/util/ip_address.h>
+
+/* Netdevice type */
+
+#include <net/if.h> // IFNAMSIZ
+
+#define foreach_netdevice_type  \
+    _(UNDEFINED)                \
+    _(LOOPBACK)                 \
+    _(WIRED)                    \
+    _(WIFI)                     \
+    _(CELLULAR)                 \
+    _(VPN)                      \
+    _(N)
+
+#define MAXSZ_NETDEVICE_TYPE_ 9
+#define MAXSZ_NETDEVICE_TYPE MAXSZ_NETDEVICE_TYPE_ + NULLTERM
+
+typedef enum {
+#define _(x) NETDEVICE_TYPE_ ## x,
+foreach_netdevice_type
+#undef _
+} netdevice_type_t;
+
+extern const char * _netdevice_type_str[];
+#define netdevice_type_str(x) _netdevice_type_str[x]
+
+
+/* Netdevice */
+
+/**
+ * \brief Netdevice type
+ *
+ * NOTE
+ *  - This struct cannot be made opaque as it is currently part of face_t
+ *  - We recommand using the API as to keep redundant attributes consistent
+ */
+typedef struct {
+    u32 index;
+    char name[IFNAMSIZ];
+} netdevice_t;
+
+#define NETDEVICE_EMPTY (netdevice_t) { \
+    .index = 0,                         \
+    .name = {0},                        \
+}
+
+netdevice_t * netdevice_create_from_index(u32 index);
+netdevice_t * netdevice_create_from_name(const char * name);
+#define netdevice_initialize_from_index netdevice_set_index
+#define netdevice_initialize_from_name netdevice_set_name
+void netdevice_free(netdevice_t * netdevice);
+int netdevice_get_index(const netdevice_t * netdevice, u32 * index);
+int netdevice_set_index(netdevice_t * netdevice, u32 index);
+int netdevice_get_name(const netdevice_t * netdevice, const char ** name);
+int netdevice_set_name(netdevice_t * netdevice, const char * name);
+int netdevice_update_index(netdevice_t * netdevice);
+int netdevice_update_name(netdevice_t * netdevice);
+int netdevice_cmp(const netdevice_t * nd1, const netdevice_t * nd2);
+
+#define NETDEVICE_UNDEFINED_INDEX 0
+
+/* Face state */
+
+#define foreach_face_state      \
+    _(UNDEFINED)                \
+    _(DOWN)                     \
+    _(UP)                       \
+    _(N)
+
+
+#define MAXSZ_FACE_STATE_ 9
+#define MAXSZ_FACE_STATE MAXSZ_FACE_STATE_ + 1
+
+typedef enum {
+#define _(x) FACE_STATE_ ## x,
+foreach_face_state
+#undef _
+} face_state_t;
+
+extern const char * _face_state_str[];
+
+#define face_state_str(x) _face_state_str[x]
+
+
+/* Face type */
+
+#define foreach_face_type       \
+    _(UNDEFINED)                \
+    _(HICN)                     \
+    _(HICN_LISTENER)            \
+    _(TCP)                      \
+    _(TCP_LISTENER)             \
+    _(UDP)                      \
+    _(UDP_LISTENER)             \
+    _(N)
+
+#define MAXSZ_FACE_TYPE_ 13
+#define MAXSZ_FACE_TYPE MAXSZ_FACE_TYPE_  + 1
+
+typedef enum {
+#define _(x) FACE_TYPE_ ## x,
+foreach_face_type
+#undef _
+} face_type_t;
+
+#define face_type_is_valid(face_type) \
+    (((face_type) >= FACE_TYPE_UNDEFINED) && (face_type < FACE_TYPE_N))
+#define face_type_is_defined(face_type) \
+    (((face_type) > FACE_TYPE_UNDEFINED) && (face_type < FACE_TYPE_N))
+
+extern const char * _face_type_str[];
+#define face_type_str(x) _face_type_str[x]
+
+
+#ifdef WITH_POLICY
+#define MAXSZ_FACE_ MAXSZ_FACE_TYPE_ + 2 * MAXSZ_URL_ + 2 * MAXSZ_FACE_STATE_ + MAXSZ_POLICY_TAGS_ + 7
+#else
+#define MAXSZ_FACE_ MAXSZ_FACE_TYPE_ + 2 * MAXSZ_URL_ + 2 * MAXSZ_FACE_STATE_ + 4
+#endif /* WITH_POLICY */
+#define MAXSZ_FACE MAXSZ_FACE_ + 1
+
+/* Face */
+
+typedef u32 face_id_t;
+
+typedef struct {
+    face_type_t type;
+    face_state_t admin_state;
+    face_state_t state;
+#ifdef WITH_POLICY
+    uint32_t priority;
+    policy_tags_t tags; /**< \see policy_tag_t */
+#endif /* WITH_POLICY */
+
+    /*
+     * Depending on the face type, some of the following fields will be unused
+     */
+    netdevice_t netdevice;
+    int family; /* To access family independently of face type */
+    ip_address_t local_addr;
+    ip_address_t remote_addr;
+    u16 local_port;
+    u16 remote_port;
+} face_t;
+
+int face_initialize(face_t * face);
+int face_initialize_udp(face_t * face, const char * interface_name,
+        const ip_address_t * local_addr, u16 local_port,
+        const ip_address_t * remote_addr, u16 remote_port,
+        int family);
+int face_initialize_udp_sa(face_t * face,
+        const char * interface_name,
+        const struct sockaddr * local_addr, const struct sockaddr * remote_addr);
+
+face_t * face_create();
+face_t * face_create_udp(const char * interface_name,
+        const ip_address_t * local_addr, u16 local_port,
+        const ip_address_t * remote_addr, u16 remote_port, int family);
+face_t * face_create_udp_sa(const char * interface_name,
+        const struct sockaddr * local_addr,
+        const struct sockaddr * remote_addr);
+
+int face_finalize(face_t * face);
+
+void face_free(face_t * face);
+
+typedef int (*face_cmp_t)(const face_t * f1, const face_t * f2);
+
+int face_cmp(const face_t * f1, const face_t * f2);
+
+size_t
+face_snprintf(char * s, size_t size, const face_t * face);
+
+policy_tags_t face_get_tags(const face_t * face);
+int face_set_tags(face_t * face, policy_tags_t tags);
+
+#endif /* HICN_FACE_H */
+
diff --git a/lib/includes/hicn/policy.h b/lib/includes/hicn/policy.h
index 51bab4241..1fe0dd766 100644
--- a/lib/includes/hicn/policy.h
+++ b/lib/includes/hicn/policy.h
@@ -147,68 +147,6 @@ typedef struct {
 
 int policy_tag_state_snprintf(char * s, size_t size, const policy_tag_state_t * tag_state);
 
-
-/* INTERFACE STATS */
-
-typedef struct {
-    float throughput;
-    float latency;
-    float loss_rate;
-} interface_stats_t;
-
-#define INTERFACE_STATS_NONE {                          \
-    .throughput = 0,                                    \
-    .latency = 0,                                       \
-    .loss_rate = 0,                                     \
-}
-
-
-/* POLICY STATS */
-
-typedef struct {
-    interface_stats_t wired;
-    interface_stats_t wifi;
-    interface_stats_t cellular;
-    interface_stats_t all;
-} policy_stats_t;
-
-#define POLICY_STATS_NONE {                     \
-    .wired    = INTERFACE_STATS_NONE,           \
-    .wifi     = INTERFACE_STATS_NONE,           \
-    .cellular = INTERFACE_STATS_NONE,           \
-    .all      = INTERFACE_STATS_NONE,           \
-}
-
-typedef struct {
-    uint32_t num_packets;
-    uint32_t num_bytes;
-    uint32_t num_losses;
-    uint32_t latency_idle;
-} interface_counters_t;
-
-#define INTERFACE_COUNTERS_NONE {               \
-    .num_packets = 0,                           \
-    .num_bytes = 0,                             \
-    .num_losses = 0,                            \
-    .latency_idle = 0,                          \
-}
-
-typedef struct {
-    interface_counters_t wired;
-    interface_counters_t wifi;
-    interface_counters_t cellular;
-    interface_counters_t all;
-    uint64_t last_update;
-} policy_counters_t;
-
-#define POLICY_COUNTERS_NONE (policy_counters_t) {      \
-    .wired    = INTERFACE_COUNTERS_NONE,                \
-    .wifi     = INTERFACE_COUNTERS_NONE,                \
-    .cellular = INTERFACE_COUNTERS_NONE,                \
-    .all      = INTERFACE_COUNTERS_NONE,                \
-    .last_update = 0,                                   \
-}
-
 /* POLICY */
 
 #define APP_NAME_LEN 128
@@ -216,7 +154,6 @@ typedef struct {
 typedef struct {
     char app_name[APP_NAME_LEN];
     policy_tag_state_t tags[POLICY_TAG_N];
-    policy_stats_t stats;
 } policy_t;
 
 static const policy_t POLICY_NONE = {
@@ -226,7 +163,6 @@ static const policy_t POLICY_NONE = {
 foreach_policy_tag
 #undef _
     },
-    .stats = POLICY_STATS_NONE,
 };
 
 
diff --git a/lib/includes/hicn/protocol/tcp.h b/lib/includes/hicn/protocol/tcp.h
index ded9a06b2..5cf1a3625 100644
--- a/lib/includes/hicn/protocol/tcp.h
+++ b/lib/includes/hicn/protocol/tcp.h
@@ -42,11 +42,7 @@ typedef struct
   union
   {
     u32 seq_ack;
-    struct
-    {
-      hicn_pathlabel_t pathlabel;
-      u8 pad[3];
-    };
+    hicn_pathlabel_t pathlabel;
   };
 
   union
diff --git a/lib/includes/hicn/util/ip_address.h b/lib/includes/hicn/util/ip_address.h
index 4facd9ad0..27880047c 100644
--- a/lib/includes/hicn/util/ip_address.h
+++ b/lib/includes/hicn/util/ip_address.h
@@ -108,6 +108,7 @@ typedef struct {
 
 #define MAXSZ_PREFIX_ MAXSZ_IP_ADDRESS_ + 1 + 3
 #define MAXSZ_PREFIX MAXSZ_PREFIX_ + 1
+#define MAXSZ_IP_PREFIX MAXSZ_PREFIX
 
 extern const ip_address_t IPV4_LOOPBACK;
 extern const ip_address_t IPV6_LOOPBACK;
@@ -146,6 +147,7 @@ int ip_address_empty(const ip_address_t * ip);
 int ip_prefix_pton (const char *ip_address_str, ip_prefix_t * ip_prefix);
 int ip_prefix_ntop_short (const ip_prefix_t * ip_prefix, char *dst, size_t size);
 int ip_prefix_ntop (const ip_prefix_t * ip_prefix, char *dst, size_t size);
+int ip_prefix_snprintf(char * s, size_t size, const ip_prefix_t * prefix);
 int ip_prefix_len (const ip_prefix_t * prefix);
 bool ip_prefix_empty (const ip_prefix_t * prefix);
 int ip_prefix_to_sockaddr(const ip_prefix_t * prefix, struct sockaddr *sa);
diff --git a/lib/src/CMakeLists.txt b/lib/src/CMakeLists.txt
index 7eecaf775..6eb4c9554 100644
--- a/lib/src/CMakeLists.txt
+++ b/lib/src/CMakeLists.txt
@@ -17,6 +17,7 @@ list(APPEND LIBHICN_SOURCE_FILES
   ${CMAKE_CURRENT_SOURCE_DIR}/common.c
   ${CMAKE_CURRENT_SOURCE_DIR}/compat.c
   ${CMAKE_CURRENT_SOURCE_DIR}/error.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/face.c
   ${CMAKE_CURRENT_SOURCE_DIR}/mapme.c
   ${CMAKE_CURRENT_SOURCE_DIR}/name.c
   ${CMAKE_CURRENT_SOURCE_DIR}/ops.c
@@ -30,7 +31,10 @@ list(APPEND LIBHICN_SOURCE_FILES
   ${CMAKE_CURRENT_SOURCE_DIR}/util/log.c
 )
 
-set (COMPILER_DEFINITIONS "-DWITH_MAPME")
+set (COMPILER_DEFINITIONS
+    "-DWITH_MAPME"
+    "-DWITH_POLICY"
+)
 
 include(BuildMacros)
 include(WindowsMacros)
diff --git a/lib/src/face.c b/lib/src/face.c
new file mode 100644
index 000000000..6d0d9c486
--- /dev/null
+++ b/lib/src/face.c
@@ -0,0 +1,422 @@
+/*
+ * Copyright (c) 2017-2019 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * \file face.c
+ * \brief Implementation of face abstraction
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <hicn/face.h>
+#include <hicn/util/token.h>
+
+#define member_size(type, member) sizeof(((type *)0)->member)
+
+
+/* Netdevice */
+
+const char * _netdevice_type_str[] = {
+#define _(x) [NETDEVICE_TYPE_ ## x] = STRINGIZE(x),
+foreach_netdevice_type
+#undef _
+};
+
+netdevice_t *
+netdevice_create_from_index(u32 index)
+{
+    netdevice_t * netdevice = malloc(sizeof(netdevice_t));
+    if (!netdevice)
+        goto ERR_MALLOC;
+
+    int rc = netdevice_set_index(netdevice, index);
+    if (rc < 0)
+        goto ERR_INIT;
+
+    return netdevice;
+
+ERR_INIT:
+    free(netdevice);
+ERR_MALLOC:
+    return NULL;
+}
+
+netdevice_t *
+netdevice_create_from_name(const char * name)
+{
+    netdevice_t * netdevice = malloc(sizeof(netdevice_t));
+    if (!netdevice)
+        goto ERR_MALLOC;
+
+    int rc = netdevice_set_name(netdevice, name);
+    if (rc < 0)
+        goto ERR_INIT;
+
+    return netdevice;
+
+ERR_INIT:
+    free(netdevice);
+ERR_MALLOC:
+    return NULL;
+}
+
+/**
+ * \brief Update the index of the netdevice based on the name
+ */
+int
+netdevice_update_index(netdevice_t * netdevice)
+{
+    netdevice->index = if_nametoindex(netdevice->name);
+    if (netdevice->index == 0)
+        return -1;
+    return 0;
+}
+
+int
+netdevice_update_name(netdevice_t * netdevice)
+{
+    if (!if_indextoname(netdevice->index, netdevice->name))
+        return -1;
+    return 0;
+}
+
+void
+netdevice_free(netdevice_t * netdevice)
+{
+    free(netdevice);
+}
+
+int
+netdevice_get_index(const netdevice_t * netdevice, u32 * index)
+{
+    if (netdevice->index == 0)
+        return -1;
+    *index = netdevice->index;
+    return 0;
+}
+
+int
+netdevice_set_index(netdevice_t * netdevice, u32 index)
+{
+    netdevice->index = index;
+    return netdevice_update_name(netdevice);
+}
+
+int
+netdevice_get_name(const netdevice_t * netdevice, const char ** name)
+{
+    if (netdevice->name[0] == '\0')
+        return -1;
+    *name = netdevice->name;
+    return 0;
+}
+
+int
+netdevice_set_name(netdevice_t * netdevice, const char * name)
+{
+    memset(netdevice->name, 0, sizeof(netdevice->name));
+    int rc = snprintf(netdevice->name, IFNAMSIZ, "%s", name);
+    if (rc < 0)
+        return -1;
+    if (rc >= IFNAMSIZ)
+        return -2; /* truncated */
+    return netdevice_update_index(netdevice);
+}
+
+int
+netdevice_cmp(const netdevice_t * nd1, const netdevice_t * nd2)
+{
+    return (nd1->index - nd2->index);
+}
+
+
+/* Face state */
+
+const char * _face_state_str[] = {
+#define _(x) [FACE_STATE_ ## x] = STRINGIZE(x),
+foreach_face_state
+#undef _
+};
+
+
+/* Face type */
+
+const char * _face_type_str[] = {
+#define _(x) [FACE_TYPE_ ## x] = STRINGIZE(x),
+foreach_face_type
+#undef _
+};
+
+
+/* Face */
+
+int
+face_initialize(face_t * face)
+{
+    memset(face, 0, sizeof(face_t));
+    return 1;
+}
+
+int
+face_initialize_udp(face_t * face, const char * interface_name, const
+        ip_address_t * local_addr, u16 local_port,
+        const ip_address_t * remote_addr, u16 remote_port,
+        int family)
+{
+    if (!local_addr)
+        return -1;
+
+    *face = (face_t) {
+        .type = FACE_TYPE_UDP,
+        .family = family,
+        .local_addr = *local_addr,
+        .local_port = local_port,
+        .remote_addr = remote_addr ? *remote_addr : IP_ADDRESS_EMPTY,
+        .remote_port = remote_port,
+    };
+
+    snprintf(face->netdevice.name, IFNAMSIZ, "%s", interface_name);
+
+    return 1;
+}
+
+int
+face_initialize_udp_sa(face_t * face, const char * interface_name,
+        const struct sockaddr * local_addr,
+        const struct sockaddr * remote_addr)
+{
+    if (!local_addr)
+        return -1;
+
+    if (remote_addr && (local_addr->sa_family != remote_addr->sa_family))
+        return -1;
+
+    switch (local_addr->sa_family) {
+        case AF_INET:
+            {
+            struct sockaddr_in *lsai = (struct sockaddr_in *)local_addr;
+            struct sockaddr_in *rsai = (struct sockaddr_in *)remote_addr;
+            *face = (face_t) {
+                .type = FACE_TYPE_UDP,
+                .family = AF_INET,
+                .local_addr.v4.as_inaddr = lsai->sin_addr,
+                .local_port = lsai ? ntohs(lsai->sin_port) : 0,
+                .remote_addr = IP_ADDRESS_EMPTY,
+                .remote_port = rsai ? ntohs(rsai->sin_port) : 0,
+            };
+            if (rsai)
+                face->remote_addr.v4.as_inaddr = rsai->sin_addr;
+            }
+            break;
+        case AF_INET6:
+            {
+            struct sockaddr_in6 *lsai = (struct sockaddr_in6 *)local_addr;
+            struct sockaddr_in6 *rsai = (struct sockaddr_in6 *)remote_addr;
+            *face = (face_t) {
+                .type = FACE_TYPE_UDP,
+                .family = AF_INET6,
+                .local_addr.v6.as_in6addr = lsai->sin6_addr,
+                .local_port = lsai ? ntohs(lsai->sin6_port) : 0,
+                .remote_addr = IP_ADDRESS_EMPTY,
+                .remote_port = rsai ? ntohs(rsai->sin6_port) : 0,
+            };
+            if (rsai)
+                face->remote_addr.v6.as_in6addr = rsai->sin6_addr;
+            }
+            break;
+        default:
+            return -1;
+    }
+
+    snprintf(face->netdevice.name, IFNAMSIZ, "%s", interface_name);
+
+    return 1;
+}
+
+face_t * face_create()
+{
+    face_t * face = calloc(1, sizeof(face_t));
+    return face;
+}
+
+face_t * face_create_udp(const char * interface_name,
+        const ip_address_t * local_addr, u16 local_port,
+        const ip_address_t * remote_addr, u16 remote_port, int family)
+{
+    face_t * face = face_create();
+    if (face_initialize_udp(face, interface_name, local_addr, local_port, remote_addr, remote_port, family) < 0)
+        goto ERR_INIT;
+    return face;
+
+ERR_INIT:
+    free(face);
+    return NULL;
+}
+
+face_t * face_create_udp_sa(const char * interface_name,
+        const struct sockaddr * local_addr,
+        const struct sockaddr * remote_addr)
+{
+    face_t * face = face_create();
+    if (face_initialize_udp_sa(face, interface_name, local_addr, remote_addr) < 0)
+        goto ERR_INIT;
+    return face;
+
+ERR_INIT:
+    free(face);
+    return NULL;
+}
+
+void face_free(face_t * face)
+{
+    free(face);
+}
+
+/**
+ * \brief Compare two faces
+ * \param [in] f1 - First face
+ * \param [in] f2 - Second face
+ * \return whether faces are equal, ie both their types are parameters are
+ * equal.
+ *
+ * NOTE: this function implements a partial order.
+ */
+int
+face_cmp(const face_t * f1, const face_t * f2)
+{
+
+    int ret = f1->type - f2->type;
+    if (ret != 0)
+        return ret;
+
+    ret = f1->family - f2->family;
+    if (ret != 0)
+        return ret;
+
+    /*
+     * FIXME As hicn-light API might not return the netdevice, we can discard the
+     * comparison when one of the two is not set for now...
+     */
+    if ((f1->netdevice.index != 0) && (f2->netdevice.index != 0)) {
+        ret = netdevice_cmp(&f1->netdevice, &f2->netdevice);
+        if (ret != 0)
+            return ret;
+    }
+
+    switch(f1->type) {
+        case FACE_TYPE_HICN:
+            ret = ip_address_cmp(&f1->local_addr, &f2->local_addr, f1->family);
+            if (ret != 0)
+                return ret;
+
+            ret = ip_address_cmp(&f1->remote_addr, &f2->remote_addr, f1->family);
+            if (ret != 0)
+                return ret;
+
+            break;
+
+        case FACE_TYPE_TCP:
+        case FACE_TYPE_UDP:
+            ret = ip_address_cmp(&f1->local_addr, &f2->local_addr, f1->family);
+            if (ret != 0)
+                return ret;
+
+            ret = f1->local_port - f2->local_port;
+            if (ret != 0)
+                return ret;
+
+            ret = ip_address_cmp(&f1->remote_addr, &f2->remote_addr, f1->family);
+            if (ret != 0)
+                return ret;
+
+            ret = f1->remote_port - f2->remote_port;
+            if (ret != 0)
+                return ret;
+
+            break;
+        default:
+            break;
+    }
+
+    return 0;
+}
+
+/* /!\ Please update constants in header file upon changes */
+size_t
+face_snprintf(char * s, size_t size, const face_t * face)
+{
+    switch(face->type) {
+        case FACE_TYPE_HICN:
+        {
+            char local[MAXSZ_IP_ADDRESS];
+            char remote[MAXSZ_IP_ADDRESS];
+            char tags[MAXSZ_POLICY_TAGS];
+
+            ip_address_snprintf(local, MAXSZ_IP_ADDRESS,
+                    &face->local_addr,
+                    face->family);
+            ip_address_snprintf(remote, MAXSZ_IP_ADDRESS,
+                    &face->remote_addr,
+                    face->family);
+            policy_tags_snprintf(tags, MAXSZ_POLICY_TAGS, face->tags);
+            return snprintf(s, size, "%s [%s -> %s] [%s]",
+                    face_type_str(face->type),
+                    local,
+                    remote,
+                    tags);
+        }
+        case FACE_TYPE_UNDEFINED:
+        case FACE_TYPE_TCP:
+        case FACE_TYPE_UDP:
+        {
+            char local[MAXSZ_IP_ADDRESS];
+            char remote[MAXSZ_IP_ADDRESS];
+            char tags[MAXSZ_POLICY_TAGS];
+
+            ip_address_snprintf(local, MAXSZ_IP_ADDRESS,
+                    &face->local_addr,
+                    face->family);
+            ip_address_snprintf(remote, MAXSZ_IP_ADDRESS,
+                    &face->remote_addr,
+                    face->family);
+            policy_tags_snprintf(tags, MAXSZ_POLICY_TAGS, face->tags);
+
+            return snprintf(s, size, "%s [%s:%d -> %s:%d] [%s]",
+                    face_type_str(face->type),
+                    local,
+                    face->local_port,
+                    remote,
+                    face->remote_port,
+                    tags);
+        }
+        default:
+            return -1;
+    }
+
+}
+
+policy_tags_t face_get_tags(const face_t * face)
+{
+    return face->tags;
+}
+
+int
+face_set_tags(face_t * face, policy_tags_t tags)
+{
+    face->tags = tags;
+    return 1;
+}
diff --git a/lib/src/util/ip_address.c b/lib/src/util/ip_address.c
index 49916547d..d4b34dc0b 100644
--- a/lib/src/util/ip_address.c
+++ b/lib/src/util/ip_address.c
@@ -302,10 +302,13 @@ ip_prefix_ntop(const ip_prefix_t * ip_prefix, char *dst, size_t size)
   }
   if (!s)
       return -1;
-  int rc = snprintf(dst, size, "%s/%d", ip_s, ip_prefix->len);
-  if (rc >= size)
-      return (int)size;
-  return rc;
+  return snprintf(dst, size, "%s/%d", ip_s, ip_prefix->len);
+}
+
+int
+ip_prefix_snprintf(char * s, size_t size, const ip_prefix_t * prefix)
+{
+    return ip_prefix_ntop(prefix, s, size);
 }
 
 int